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_EEPRO100 742 Support for Intel 82557/82559/82559ER chips. 743 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 744 write routine for first time initialisation. 745 746 CONFIG_TULIP 747 Support for Digital 2114x chips. 748 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 749 modem chip initialisation (KS8761/QS6611). 750 751 CONFIG_NATSEMI 752 Support for National dp83815 chips. 753 754 CONFIG_NS8382X 755 Support for National dp8382[01] gigabit chips. 756 757- NETWORK Support (other): 758 759 CONFIG_DRIVER_LAN91C96 760 Support for SMSC's LAN91C96 chips. 761 762 CONFIG_LAN91C96_BASE 763 Define this to hold the physical address 764 of the LAN91C96's I/O space 765 766 CONFIG_LAN91C96_USE_32_BIT 767 Define this to enable 32 bit addressing 768 769 CONFIG_DRIVER_SMC91111 770 Support for SMSC's LAN91C111 chip 771 772 CONFIG_SMC91111_BASE 773 Define this to hold the physical address 774 of the device (I/O space) 775 776 CONFIG_SMC_USE_32_BIT 777 Define this if data bus is 32 bits 778 779 CONFIG_SMC_USE_IOFUNCS 780 Define this to use i/o functions instead of macros 781 (some hardware wont work with macros) 782 783- USB Support: 784 At the moment only the UHCI host controller is 785 supported (PIP405, MIP405, MPC5200); define 786 CONFIG_USB_UHCI to enable it. 787 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 788 and define CONFIG_USB_STORAGE to enable the USB 789 storage devices. 790 Note: 791 Supported are USB Keyboards and USB Floppy drives 792 (TEAC FD-05PUB). 793 MPC5200 USB requires additional defines: 794 CONFIG_USB_CLOCK 795 for 528 MHz Clock: 0x0001bbbb 796 CONFIG_USB_CONFIG 797 for differential drivers: 0x00001000 798 for single ended drivers: 0x00005000 799 CFG_USB_EVENT_POLL 800 May be defined to allow interrupt polling 801 instead of using asynchronous interrupts 802 803- USB Device: 804 Define the below if you wish to use the USB console. 805 Once firmware is rebuilt from a serial console issue the 806 command "setenv stdin usbtty; setenv stdout usbtty" and 807 attach your usb cable. The Unix command "dmesg" should print 808 it has found a new device. The environment variable usbtty 809 can be set to gserial or cdc_acm to enable your device to 810 appear to a USB host as a Linux gserial device or a 811 Common Device Class Abstract Control Model serial device. 812 If you select usbtty = gserial you should be able to enumerate 813 a Linux host by 814 # modprobe usbserial vendor=0xVendorID product=0xProductID 815 else if using cdc_acm, simply setting the environment 816 variable usbtty to be cdc_acm should suffice. The following 817 might be defined in YourBoardName.h 818 819 CONFIG_USB_DEVICE 820 Define this to build a UDC device 821 822 CONFIG_USB_TTY 823 Define this to have a tty type of device available to 824 talk to the UDC device 825 826 CFG_CONSOLE_IS_IN_ENV 827 Define this if you want stdin, stdout &/or stderr to 828 be set to usbtty. 829 830 mpc8xx: 831 CFG_USB_EXTC_CLK 0xBLAH 832 Derive USB clock from external clock "blah" 833 - CFG_USB_EXTC_CLK 0x02 834 835 CFG_USB_BRG_CLK 0xBLAH 836 Derive USB clock from brgclk 837 - CFG_USB_BRG_CLK 0x04 838 839 If you have a USB-IF assigned VendorID then you may wish to 840 define your own vendor specific values either in BoardName.h 841 or directly in usbd_vendor_info.h. If you don't define 842 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 843 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 844 should pretend to be a Linux device to it's target host. 845 846 CONFIG_USBD_MANUFACTURER 847 Define this string as the name of your company for 848 - CONFIG_USBD_MANUFACTURER "my company" 849 850 CONFIG_USBD_PRODUCT_NAME 851 Define this string as the name of your product 852 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 853 854 CONFIG_USBD_VENDORID 855 Define this as your assigned Vendor ID from the USB 856 Implementors Forum. This *must* be a genuine Vendor ID 857 to avoid polluting the USB namespace. 858 - CONFIG_USBD_VENDORID 0xFFFF 859 860 CONFIG_USBD_PRODUCTID 861 Define this as the unique Product ID 862 for your device 863 - CONFIG_USBD_PRODUCTID 0xFFFF 864 865 866- MMC Support: 867 The MMC controller on the Intel PXA is supported. To 868 enable this define CONFIG_MMC. The MMC can be 869 accessed from the boot prompt by mapping the device 870 to physical memory similar to flash. Command line is 871 enabled with CONFIG_CMD_MMC. The MMC driver also works with 872 the FAT fs. This is enabled with CONFIG_CMD_FAT. 873 874- Journaling Flash filesystem support: 875 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 876 CONFIG_JFFS2_NAND_DEV 877 Define these for a default partition on a NAND device 878 879 CFG_JFFS2_FIRST_SECTOR, 880 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 881 Define these for a default partition on a NOR device 882 883 CFG_JFFS_CUSTOM_PART 884 Define this to create an own partition. You have to provide a 885 function struct part_info* jffs2_part_info(int part_num) 886 887 If you define only one JFFS2 partition you may also want to 888 #define CFG_JFFS_SINGLE_PART 1 889 to disable the command chpart. This is the default when you 890 have not defined a custom partition 891 892- Keyboard Support: 893 CONFIG_ISA_KEYBOARD 894 895 Define this to enable standard (PC-Style) keyboard 896 support 897 898 CONFIG_I8042_KBD 899 Standard PC keyboard driver with US (is default) and 900 GERMAN key layout (switch via environment 'keymap=de') support. 901 Export function i8042_kbd_init, i8042_tstc and i8042_getc 902 for cfb_console. Supports cursor blinking. 903 904- Video support: 905 CONFIG_VIDEO 906 907 Define this to enable video support (for output to 908 video). 909 910 CONFIG_VIDEO_CT69000 911 912 Enable Chips & Technologies 69000 Video chip 913 914 CONFIG_VIDEO_SMI_LYNXEM 915 Enable Silicon Motion SMI 712/710/810 Video chip. The 916 video output is selected via environment 'videoout' 917 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 918 assumed. 919 920 For the CT69000 and SMI_LYNXEM drivers, videomode is 921 selected via environment 'videomode'. Two diferent ways 922 are possible: 923 - "videomode=num" 'num' is a standard LiLo mode numbers. 924 Following standard modes are supported (* is default): 925 926 Colors 640x480 800x600 1024x768 1152x864 1280x1024 927 -------------+--------------------------------------------- 928 8 bits | 0x301* 0x303 0x305 0x161 0x307 929 15 bits | 0x310 0x313 0x316 0x162 0x319 930 16 bits | 0x311 0x314 0x317 0x163 0x31A 931 24 bits | 0x312 0x315 0x318 ? 0x31B 932 -------------+--------------------------------------------- 933 (i.e. setenv videomode 317; saveenv; reset;) 934 935 - "videomode=bootargs" all the video parameters are parsed 936 from the bootargs. (See drivers/video/videomodes.c) 937 938 939 CONFIG_VIDEO_SED13806 940 Enable Epson SED13806 driver. This driver supports 8bpp 941 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 942 or CONFIG_VIDEO_SED13806_16BPP 943 944- Keyboard Support: 945 CONFIG_KEYBOARD 946 947 Define this to enable a custom keyboard support. 948 This simply calls drv_keyboard_init() which must be 949 defined in your board-specific files. 950 The only board using this so far is RBC823. 951 952- LCD Support: CONFIG_LCD 953 954 Define this to enable LCD support (for output to LCD 955 display); also select one of the supported displays 956 by defining one of these: 957 958 CONFIG_NEC_NL6448AC33: 959 960 NEC NL6448AC33-18. Active, color, single scan. 961 962 CONFIG_NEC_NL6448BC20 963 964 NEC NL6448BC20-08. 6.5", 640x480. 965 Active, color, single scan. 966 967 CONFIG_NEC_NL6448BC33_54 968 969 NEC NL6448BC33-54. 10.4", 640x480. 970 Active, color, single scan. 971 972 CONFIG_SHARP_16x9 973 974 Sharp 320x240. Active, color, single scan. 975 It isn't 16x9, and I am not sure what it is. 976 977 CONFIG_SHARP_LQ64D341 978 979 Sharp LQ64D341 display, 640x480. 980 Active, color, single scan. 981 982 CONFIG_HLD1045 983 984 HLD1045 display, 640x480. 985 Active, color, single scan. 986 987 CONFIG_OPTREX_BW 988 989 Optrex CBL50840-2 NF-FW 99 22 M5 990 or 991 Hitachi LMG6912RPFC-00T 992 or 993 Hitachi SP14Q002 994 995 320x240. Black & white. 996 997 Normally display is black on white background; define 998 CFG_WHITE_ON_BLACK to get it inverted. 999 1000- Splash Screen Support: CONFIG_SPLASH_SCREEN 1001 1002 If this option is set, the environment is checked for 1003 a variable "splashimage". If found, the usual display 1004 of logo, copyright and system information on the LCD 1005 is suppressed and the BMP image at the address 1006 specified in "splashimage" is loaded instead. The 1007 console is redirected to the "nulldev", too. This 1008 allows for a "silent" boot where a splash screen is 1009 loaded very quickly after power-on. 1010 1011- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1012 1013 If this option is set, additionally to standard BMP 1014 images, gzipped BMP images can be displayed via the 1015 splashscreen support or the bmp command. 1016 1017- Compression support: 1018 CONFIG_BZIP2 1019 1020 If this option is set, support for bzip2 compressed 1021 images is included. If not, only uncompressed and gzip 1022 compressed images are supported. 1023 1024 NOTE: the bzip2 algorithm requires a lot of RAM, so 1025 the malloc area (as defined by CFG_MALLOC_LEN) should 1026 be at least 4MB. 1027 1028- MII/PHY support: 1029 CONFIG_PHY_ADDR 1030 1031 The address of PHY on MII bus. 1032 1033 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1034 1035 The clock frequency of the MII bus 1036 1037 CONFIG_PHY_GIGE 1038 1039 If this option is set, support for speed/duplex 1040 detection of Gigabit PHY is included. 1041 1042 CONFIG_PHY_RESET_DELAY 1043 1044 Some PHY like Intel LXT971A need extra delay after 1045 reset before any MII register access is possible. 1046 For such PHY, set this option to the usec delay 1047 required. (minimum 300usec for LXT971A) 1048 1049 CONFIG_PHY_CMD_DELAY (ppc4xx) 1050 1051 Some PHY like Intel LXT971A need extra delay after 1052 command issued before MII status register can be read 1053 1054- Ethernet address: 1055 CONFIG_ETHADDR 1056 CONFIG_ETH2ADDR 1057 CONFIG_ETH3ADDR 1058 1059 Define a default value for ethernet address to use 1060 for the respective ethernet interface, in case this 1061 is not determined automatically. 1062 1063- IP address: 1064 CONFIG_IPADDR 1065 1066 Define a default value for the IP address to use for 1067 the default ethernet interface, in case this is not 1068 determined through e.g. bootp. 1069 1070- Server IP address: 1071 CONFIG_SERVERIP 1072 1073 Defines a default value for theIP address of a TFTP 1074 server to contact when using the "tftboot" command. 1075 1076- Multicast TFTP Mode: 1077 CONFIG_MCAST_TFTP 1078 1079 Defines whether you want to support multicast TFTP as per 1080 rfc-2090; for example to work with atftp. Lets lots of targets 1081 tftp down the same boot image concurrently. Note: the ethernet 1082 driver in use must provide a function: mcast() to join/leave a 1083 multicast group. 1084 1085 CONFIG_BOOTP_RANDOM_DELAY 1086- BOOTP Recovery Mode: 1087 CONFIG_BOOTP_RANDOM_DELAY 1088 1089 If you have many targets in a network that try to 1090 boot using BOOTP, you may want to avoid that all 1091 systems send out BOOTP requests at precisely the same 1092 moment (which would happen for instance at recovery 1093 from a power failure, when all systems will try to 1094 boot, thus flooding the BOOTP server. Defining 1095 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1096 inserted before sending out BOOTP requests. The 1097 following delays are inserted then: 1098 1099 1st BOOTP request: delay 0 ... 1 sec 1100 2nd BOOTP request: delay 0 ... 2 sec 1101 3rd BOOTP request: delay 0 ... 4 sec 1102 4th and following 1103 BOOTP requests: delay 0 ... 8 sec 1104 1105- DHCP Advanced Options: 1106 You can fine tune the DHCP functionality by defining 1107 CONFIG_BOOTP_* symbols: 1108 1109 CONFIG_BOOTP_SUBNETMASK 1110 CONFIG_BOOTP_GATEWAY 1111 CONFIG_BOOTP_HOSTNAME 1112 CONFIG_BOOTP_NISDOMAIN 1113 CONFIG_BOOTP_BOOTPATH 1114 CONFIG_BOOTP_BOOTFILESIZE 1115 CONFIG_BOOTP_DNS 1116 CONFIG_BOOTP_DNS2 1117 CONFIG_BOOTP_SEND_HOSTNAME 1118 CONFIG_BOOTP_NTPSERVER 1119 CONFIG_BOOTP_TIMEOFFSET 1120 CONFIG_BOOTP_VENDOREX 1121 1122 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1123 environment variable, not the BOOTP server. 1124 1125 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1126 serverip from a DHCP server, it is possible that more 1127 than one DNS serverip is offered to the client. 1128 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1129 serverip will be stored in the additional environment 1130 variable "dnsip2". The first DNS serverip is always 1131 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1132 is defined. 1133 1134 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1135 to do a dynamic update of a DNS server. To do this, they 1136 need the hostname of the DHCP requester. 1137 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1138 of the "hostname" environment variable is passed as 1139 option 12 to the DHCP server. 1140 1141 - CDP Options: 1142 CONFIG_CDP_DEVICE_ID 1143 1144 The device id used in CDP trigger frames. 1145 1146 CONFIG_CDP_DEVICE_ID_PREFIX 1147 1148 A two character string which is prefixed to the MAC address 1149 of the device. 1150 1151 CONFIG_CDP_PORT_ID 1152 1153 A printf format string which contains the ascii name of 1154 the port. Normally is set to "eth%d" which sets 1155 eth0 for the first ethernet, eth1 for the second etc. 1156 1157 CONFIG_CDP_CAPABILITIES 1158 1159 A 32bit integer which indicates the device capabilities; 1160 0x00000010 for a normal host which does not forwards. 1161 1162 CONFIG_CDP_VERSION 1163 1164 An ascii string containing the version of the software. 1165 1166 CONFIG_CDP_PLATFORM 1167 1168 An ascii string containing the name of the platform. 1169 1170 CONFIG_CDP_TRIGGER 1171 1172 A 32bit integer sent on the trigger. 1173 1174 CONFIG_CDP_POWER_CONSUMPTION 1175 1176 A 16bit integer containing the power consumption of the 1177 device in .1 of milliwatts. 1178 1179 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1180 1181 A byte containing the id of the VLAN. 1182 1183- Status LED: CONFIG_STATUS_LED 1184 1185 Several configurations allow to display the current 1186 status using a LED. For instance, the LED will blink 1187 fast while running U-Boot code, stop blinking as 1188 soon as a reply to a BOOTP request was received, and 1189 start blinking slow once the Linux kernel is running 1190 (supported by a status LED driver in the Linux 1191 kernel). Defining CONFIG_STATUS_LED enables this 1192 feature in U-Boot. 1193 1194- CAN Support: CONFIG_CAN_DRIVER 1195 1196 Defining CONFIG_CAN_DRIVER enables CAN driver support 1197 on those systems that support this (optional) 1198 feature, like the TQM8xxL modules. 1199 1200- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1201 1202 These enable I2C serial bus commands. Defining either of 1203 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1204 include the appropriate I2C driver for the selected cpu. 1205 1206 This will allow you to use i2c commands at the u-boot 1207 command line (as long as you set CONFIG_CMD_I2C in 1208 CONFIG_COMMANDS) and communicate with i2c based realtime 1209 clock chips. See common/cmd_i2c.c for a description of the 1210 command line interface. 1211 1212 CONFIG_I2C_CMD_TREE is a recommended option that places 1213 all I2C commands under a single 'i2c' root command. The 1214 older 'imm', 'imd', 'iprobe' etc. commands are considered 1215 deprecated and may disappear in the future. 1216 1217 CONFIG_HARD_I2C selects a hardware I2C controller. 1218 1219 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1220 bit-banging) driver instead of CPM or similar hardware 1221 support for I2C. 1222 1223 There are several other quantities that must also be 1224 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1225 1226 In both cases you will need to define CFG_I2C_SPEED 1227 to be the frequency (in Hz) at which you wish your i2c bus 1228 to run and CFG_I2C_SLAVE to be the address of this node (ie 1229 the cpu's i2c node address). 1230 1231 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1232 sets the cpu up as a master node and so its address should 1233 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1234 p.16-473). So, set CFG_I2C_SLAVE to 0. 1235 1236 That's all that's required for CONFIG_HARD_I2C. 1237 1238 If you use the software i2c interface (CONFIG_SOFT_I2C) 1239 then the following macros need to be defined (examples are 1240 from include/configs/lwmon.h): 1241 1242 I2C_INIT 1243 1244 (Optional). Any commands necessary to enable the I2C 1245 controller or configure ports. 1246 1247 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1248 1249 I2C_PORT 1250 1251 (Only for MPC8260 CPU). The I/O port to use (the code 1252 assumes both bits are on the same port). Valid values 1253 are 0..3 for ports A..D. 1254 1255 I2C_ACTIVE 1256 1257 The code necessary to make the I2C data line active 1258 (driven). If the data line is open collector, this 1259 define can be null. 1260 1261 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1262 1263 I2C_TRISTATE 1264 1265 The code necessary to make the I2C data line tri-stated 1266 (inactive). If the data line is open collector, this 1267 define can be null. 1268 1269 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1270 1271 I2C_READ 1272 1273 Code that returns TRUE if the I2C data line is high, 1274 FALSE if it is low. 1275 1276 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1277 1278 I2C_SDA(bit) 1279 1280 If <bit> is TRUE, sets the I2C data line high. If it 1281 is FALSE, it clears it (low). 1282 1283 eg: #define I2C_SDA(bit) \ 1284 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1285 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1286 1287 I2C_SCL(bit) 1288 1289 If <bit> is TRUE, sets the I2C clock line high. If it 1290 is FALSE, it clears it (low). 1291 1292 eg: #define I2C_SCL(bit) \ 1293 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1294 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1295 1296 I2C_DELAY 1297 1298 This delay is invoked four times per clock cycle so this 1299 controls the rate of data transfer. The data rate thus 1300 is 1 / (I2C_DELAY * 4). Often defined to be something 1301 like: 1302 1303 #define I2C_DELAY udelay(2) 1304 1305 CFG_I2C_INIT_BOARD 1306 1307 When a board is reset during an i2c bus transfer 1308 chips might think that the current transfer is still 1309 in progress. On some boards it is possible to access 1310 the i2c SCLK line directly, either by using the 1311 processor pin as a GPIO or by having a second pin 1312 connected to the bus. If this option is defined a 1313 custom i2c_init_board() routine in boards/xxx/board.c 1314 is run early in the boot sequence. 1315 1316 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1317 1318 This option enables configuration of bi_iic_fast[] flags 1319 in u-boot bd_info structure based on u-boot environment 1320 variable "i2cfast". (see also i2cfast) 1321 1322 CONFIG_I2C_MULTI_BUS 1323 1324 This option allows the use of multiple I2C buses, each of which 1325 must have a controller. At any point in time, only one bus is 1326 active. To switch to a different bus, use the 'i2c dev' command. 1327 Note that bus numbering is zero-based. 1328 1329 CFG_I2C_NOPROBES 1330 1331 This option specifies a list of I2C devices that will be skipped 1332 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1333 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1334 pairs. Otherwise, specify a 1D array of device addresses 1335 1336 e.g. 1337 #undef CONFIG_I2C_MULTI_BUS 1338 #define CFG_I2C_NOPROBES {0x50,0x68} 1339 1340 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1341 1342 #define CONFIG_I2C_MULTI_BUS 1343 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1344 1345 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1346 1347 CFG_SPD_BUS_NUM 1348 1349 If defined, then this indicates the I2C bus number for DDR SPD. 1350 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1351 1352 CFG_RTC_BUS_NUM 1353 1354 If defined, then this indicates the I2C bus number for the RTC. 1355 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1356 1357 CFG_DTT_BUS_NUM 1358 1359 If defined, then this indicates the I2C bus number for the DTT. 1360 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1361 1362 CONFIG_FSL_I2C 1363 1364 Define this option if you want to use Freescale's I2C driver in 1365 drivers/i2c/fsl_i2c.c. 1366 1367 1368- SPI Support: CONFIG_SPI 1369 1370 Enables SPI driver (so far only tested with 1371 SPI EEPROM, also an instance works with Crystal A/D and 1372 D/As on the SACSng board) 1373 1374 CONFIG_SPI_X 1375 1376 Enables extended (16-bit) SPI EEPROM addressing. 1377 (symmetrical to CONFIG_I2C_X) 1378 1379 CONFIG_SOFT_SPI 1380 1381 Enables a software (bit-bang) SPI driver rather than 1382 using hardware support. This is a general purpose 1383 driver that only requires three general I/O port pins 1384 (two outputs, one input) to function. If this is 1385 defined, the board configuration must define several 1386 SPI configuration items (port pins to use, etc). For 1387 an example, see include/configs/sacsng.h. 1388 1389 CONFIG_HARD_SPI 1390 1391 Enables a hardware SPI driver for general-purpose reads 1392 and writes. As with CONFIG_SOFT_SPI, the board configuration 1393 must define a list of chip-select function pointers. 1394 Currently supported on some MPC8xxx processors. For an 1395 example, see include/configs/mpc8349emds.h. 1396 1397- FPGA Support: CONFIG_FPGA 1398 1399 Enables FPGA subsystem. 1400 1401 CONFIG_FPGA_<vendor> 1402 1403 Enables support for specific chip vendors. 1404 (ALTERA, XILINX) 1405 1406 CONFIG_FPGA_<family> 1407 1408 Enables support for FPGA family. 1409 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1410 1411 CONFIG_FPGA_COUNT 1412 1413 Specify the number of FPGA devices to support. 1414 1415 CFG_FPGA_PROG_FEEDBACK 1416 1417 Enable printing of hash marks during FPGA configuration. 1418 1419 CFG_FPGA_CHECK_BUSY 1420 1421 Enable checks on FPGA configuration interface busy 1422 status by the configuration function. This option 1423 will require a board or device specific function to 1424 be written. 1425 1426 CONFIG_FPGA_DELAY 1427 1428 If defined, a function that provides delays in the FPGA 1429 configuration driver. 1430 1431 CFG_FPGA_CHECK_CTRLC 1432 Allow Control-C to interrupt FPGA configuration 1433 1434 CFG_FPGA_CHECK_ERROR 1435 1436 Check for configuration errors during FPGA bitfile 1437 loading. For example, abort during Virtex II 1438 configuration if the INIT_B line goes low (which 1439 indicated a CRC error). 1440 1441 CFG_FPGA_WAIT_INIT 1442 1443 Maximum time to wait for the INIT_B line to deassert 1444 after PROB_B has been deasserted during a Virtex II 1445 FPGA configuration sequence. The default time is 500 1446 mS. 1447 1448 CFG_FPGA_WAIT_BUSY 1449 1450 Maximum time to wait for BUSY to deassert during 1451 Virtex II FPGA configuration. The default is 5 mS. 1452 1453 CFG_FPGA_WAIT_CONFIG 1454 1455 Time to wait after FPGA configuration. The default is 1456 200 mS. 1457 1458- Configuration Management: 1459 CONFIG_IDENT_STRING 1460 1461 If defined, this string will be added to the U-Boot 1462 version information (U_BOOT_VERSION) 1463 1464- Vendor Parameter Protection: 1465 1466 U-Boot considers the values of the environment 1467 variables "serial#" (Board Serial Number) and 1468 "ethaddr" (Ethernet Address) to be parameters that 1469 are set once by the board vendor / manufacturer, and 1470 protects these variables from casual modification by 1471 the user. Once set, these variables are read-only, 1472 and write or delete attempts are rejected. You can 1473 change this behviour: 1474 1475 If CONFIG_ENV_OVERWRITE is #defined in your config 1476 file, the write protection for vendor parameters is 1477 completely disabled. Anybody can change or delete 1478 these parameters. 1479 1480 Alternatively, if you #define _both_ CONFIG_ETHADDR 1481 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1482 ethernet address is installed in the environment, 1483 which can be changed exactly ONCE by the user. [The 1484 serial# is unaffected by this, i. e. it remains 1485 read-only.] 1486 1487- Protected RAM: 1488 CONFIG_PRAM 1489 1490 Define this variable to enable the reservation of 1491 "protected RAM", i. e. RAM which is not overwritten 1492 by U-Boot. Define CONFIG_PRAM to hold the number of 1493 kB you want to reserve for pRAM. You can overwrite 1494 this default value by defining an environment 1495 variable "pram" to the number of kB you want to 1496 reserve. Note that the board info structure will 1497 still show the full amount of RAM. If pRAM is 1498 reserved, a new environment variable "mem" will 1499 automatically be defined to hold the amount of 1500 remaining RAM in a form that can be passed as boot 1501 argument to Linux, for instance like that: 1502 1503 setenv bootargs ... mem=\${mem} 1504 saveenv 1505 1506 This way you can tell Linux not to use this memory, 1507 either, which results in a memory region that will 1508 not be affected by reboots. 1509 1510 *WARNING* If your board configuration uses automatic 1511 detection of the RAM size, you must make sure that 1512 this memory test is non-destructive. So far, the 1513 following board configurations are known to be 1514 "pRAM-clean": 1515 1516 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1517 HERMES, IP860, RPXlite, LWMON, LANTEC, 1518 PCU_E, FLAGADM, TQM8260 1519 1520- Error Recovery: 1521 CONFIG_PANIC_HANG 1522 1523 Define this variable to stop the system in case of a 1524 fatal error, so that you have to reset it manually. 1525 This is probably NOT a good idea for an embedded 1526 system where you want to system to reboot 1527 automatically as fast as possible, but it may be 1528 useful during development since you can try to debug 1529 the conditions that lead to the situation. 1530 1531 CONFIG_NET_RETRY_COUNT 1532 1533 This variable defines the number of retries for 1534 network operations like ARP, RARP, TFTP, or BOOTP 1535 before giving up the operation. If not defined, a 1536 default value of 5 is used. 1537 1538- Command Interpreter: 1539 CONFIG_AUTO_COMPLETE 1540 1541 Enable auto completion of commands using TAB. 1542 1543 Note that this feature has NOT been implemented yet 1544 for the "hush" shell. 1545 1546 1547 CFG_HUSH_PARSER 1548 1549 Define this variable to enable the "hush" shell (from 1550 Busybox) as command line interpreter, thus enabling 1551 powerful command line syntax like 1552 if...then...else...fi conditionals or `&&' and '||' 1553 constructs ("shell scripts"). 1554 1555 If undefined, you get the old, much simpler behaviour 1556 with a somewhat smaller memory footprint. 1557 1558 1559 CFG_PROMPT_HUSH_PS2 1560 1561 This defines the secondary prompt string, which is 1562 printed when the command interpreter needs more input 1563 to complete a command. Usually "> ". 1564 1565 Note: 1566 1567 In the current implementation, the local variables 1568 space and global environment variables space are 1569 separated. Local variables are those you define by 1570 simply typing `name=value'. To access a local 1571 variable later on, you have write `$name' or 1572 `${name}'; to execute the contents of a variable 1573 directly type `$name' at the command prompt. 1574 1575 Global environment variables are those you use 1576 setenv/printenv to work with. To run a command stored 1577 in such a variable, you need to use the run command, 1578 and you must not use the '$' sign to access them. 1579 1580 To store commands and special characters in a 1581 variable, please use double quotation marks 1582 surrounding the whole text of the variable, instead 1583 of the backslashes before semicolons and special 1584 symbols. 1585 1586- Commandline Editing and History: 1587 CONFIG_CMDLINE_EDITING 1588 1589 Enable editiong and History functions for interactive 1590 commandline input operations 1591 1592- Default Environment: 1593 CONFIG_EXTRA_ENV_SETTINGS 1594 1595 Define this to contain any number of null terminated 1596 strings (variable = value pairs) that will be part of 1597 the default environment compiled into the boot image. 1598 1599 For example, place something like this in your 1600 board's config file: 1601 1602 #define CONFIG_EXTRA_ENV_SETTINGS \ 1603 "myvar1=value1\0" \ 1604 "myvar2=value2\0" 1605 1606 Warning: This method is based on knowledge about the 1607 internal format how the environment is stored by the 1608 U-Boot code. This is NOT an official, exported 1609 interface! Although it is unlikely that this format 1610 will change soon, there is no guarantee either. 1611 You better know what you are doing here. 1612 1613 Note: overly (ab)use of the default environment is 1614 discouraged. Make sure to check other ways to preset 1615 the environment like the autoscript function or the 1616 boot command first. 1617 1618- DataFlash Support: 1619 CONFIG_HAS_DATAFLASH 1620 1621 Defining this option enables DataFlash features and 1622 allows to read/write in Dataflash via the standard 1623 commands cp, md... 1624 1625- SystemACE Support: 1626 CONFIG_SYSTEMACE 1627 1628 Adding this option adds support for Xilinx SystemACE 1629 chips attached via some sort of local bus. The address 1630 of the chip must alsh be defined in the 1631 CFG_SYSTEMACE_BASE macro. For example: 1632 1633 #define CONFIG_SYSTEMACE 1634 #define CFG_SYSTEMACE_BASE 0xf0000000 1635 1636 When SystemACE support is added, the "ace" device type 1637 becomes available to the fat commands, i.e. fatls. 1638 1639- TFTP Fixed UDP Port: 1640 CONFIG_TFTP_PORT 1641 1642 If this is defined, the environment variable tftpsrcp 1643 is used to supply the TFTP UDP source port value. 1644 If tftpsrcp isn't defined, the normal pseudo-random port 1645 number generator is used. 1646 1647 Also, the environment variable tftpdstp is used to supply 1648 the TFTP UDP destination port value. If tftpdstp isn't 1649 defined, the normal port 69 is used. 1650 1651 The purpose for tftpsrcp is to allow a TFTP server to 1652 blindly start the TFTP transfer using the pre-configured 1653 target IP address and UDP port. This has the effect of 1654 "punching through" the (Windows XP) firewall, allowing 1655 the remainder of the TFTP transfer to proceed normally. 1656 A better solution is to properly configure the firewall, 1657 but sometimes that is not allowed. 1658 1659- Show boot progress: 1660 CONFIG_SHOW_BOOT_PROGRESS 1661 1662 Defining this option allows to add some board- 1663 specific code (calling a user-provided function 1664 "show_boot_progress(int)") that enables you to show 1665 the system's boot progress on some display (for 1666 example, some LED's) on your board. At the moment, 1667 the following checkpoints are implemented: 1668 1669Legacy uImage format: 1670 1671 Arg Where When 1672 1 common/cmd_bootm.c before attempting to boot an image 1673 -1 common/cmd_bootm.c Image header has bad magic number 1674 2 common/cmd_bootm.c Image header has correct magic number 1675 -2 common/cmd_bootm.c Image header has bad checksum 1676 3 common/cmd_bootm.c Image header has correct checksum 1677 -3 common/cmd_bootm.c Image data has bad checksum 1678 4 common/cmd_bootm.c Image data has correct checksum 1679 -4 common/cmd_bootm.c Image is for unsupported architecture 1680 5 common/cmd_bootm.c Architecture check OK 1681 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1682 6 common/cmd_bootm.c Image Type check OK 1683 -6 common/cmd_bootm.c gunzip uncompression error 1684 -7 common/cmd_bootm.c Unimplemented compression type 1685 7 common/cmd_bootm.c Uncompression OK 1686 8 common/cmd_bootm.c No uncompress/copy overwrite error 1687 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1688 1689 9 common/image.c Start initial ramdisk verification 1690 -10 common/image.c Ramdisk header has bad magic number 1691 -11 common/image.c Ramdisk header has bad checksum 1692 10 common/image.c Ramdisk header is OK 1693 -12 common/image.c Ramdisk data has bad checksum 1694 11 common/image.c Ramdisk data has correct checksum 1695 12 common/image.c Ramdisk verification complete, start loading 1696 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1697 13 common/image.c Start multifile image verification 1698 14 common/image.c No initial ramdisk, no multifile, continue. 1699 1700 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1701 1702 -30 lib_ppc/board.c Fatal error, hang the system 1703 -31 post/post.c POST test failed, detected by post_output_backlog() 1704 -32 post/post.c POST test failed, detected by post_run_single() 1705 1706 34 common/cmd_doc.c before loading a Image from a DOC device 1707 -35 common/cmd_doc.c Bad usage of "doc" command 1708 35 common/cmd_doc.c correct usage of "doc" command 1709 -36 common/cmd_doc.c No boot device 1710 36 common/cmd_doc.c correct boot device 1711 -37 common/cmd_doc.c Unknown Chip ID on boot device 1712 37 common/cmd_doc.c correct chip ID found, device available 1713 -38 common/cmd_doc.c Read Error on boot device 1714 38 common/cmd_doc.c reading Image header from DOC device OK 1715 -39 common/cmd_doc.c Image header has bad magic number 1716 39 common/cmd_doc.c Image header has correct magic number 1717 -40 common/cmd_doc.c Error reading Image from DOC device 1718 40 common/cmd_doc.c Image header has correct magic number 1719 41 common/cmd_ide.c before loading a Image from a IDE device 1720 -42 common/cmd_ide.c Bad usage of "ide" command 1721 42 common/cmd_ide.c correct usage of "ide" command 1722 -43 common/cmd_ide.c No boot device 1723 43 common/cmd_ide.c boot device found 1724 -44 common/cmd_ide.c Device not available 1725 44 common/cmd_ide.c Device available 1726 -45 common/cmd_ide.c wrong partition selected 1727 45 common/cmd_ide.c partition selected 1728 -46 common/cmd_ide.c Unknown partition table 1729 46 common/cmd_ide.c valid partition table found 1730 -47 common/cmd_ide.c Invalid partition type 1731 47 common/cmd_ide.c correct partition type 1732 -48 common/cmd_ide.c Error reading Image Header on boot device 1733 48 common/cmd_ide.c reading Image Header from IDE device OK 1734 -49 common/cmd_ide.c Image header has bad magic number 1735 49 common/cmd_ide.c Image header has correct magic number 1736 -50 common/cmd_ide.c Image header has bad checksum 1737 50 common/cmd_ide.c Image header has correct checksum 1738 -51 common/cmd_ide.c Error reading Image from IDE device 1739 51 common/cmd_ide.c reading Image from IDE device OK 1740 52 common/cmd_nand.c before loading a Image from a NAND device 1741 -53 common/cmd_nand.c Bad usage of "nand" command 1742 53 common/cmd_nand.c correct usage of "nand" command 1743 -54 common/cmd_nand.c No boot device 1744 54 common/cmd_nand.c boot device found 1745 -55 common/cmd_nand.c Unknown Chip ID on boot device 1746 55 common/cmd_nand.c correct chip ID found, device available 1747 -56 common/cmd_nand.c Error reading Image Header on boot device 1748 56 common/cmd_nand.c reading Image Header from NAND device OK 1749 -57 common/cmd_nand.c Image header has bad magic number 1750 57 common/cmd_nand.c Image header has correct magic number 1751 -58 common/cmd_nand.c Error reading Image from NAND device 1752 58 common/cmd_nand.c reading Image from NAND device OK 1753 1754 -60 common/env_common.c Environment has a bad CRC, using default 1755 1756 64 net/eth.c starting with Ethernetconfiguration. 1757 -64 net/eth.c no Ethernet found. 1758 65 net/eth.c Ethernet found. 1759 1760 -80 common/cmd_net.c usage wrong 1761 80 common/cmd_net.c before calling NetLoop() 1762 -81 common/cmd_net.c some error in NetLoop() occured 1763 81 common/cmd_net.c NetLoop() back without error 1764 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1765 82 common/cmd_net.c trying automatic boot 1766 83 common/cmd_net.c running autoscript 1767 -83 common/cmd_net.c some error in automatic boot or autoscript 1768 84 common/cmd_net.c end without errors 1769 1770FIT uImage format: 1771 1772 Arg Where When 1773 100 common/cmd_bootm.c Kernel FIT Image has correct format 1774 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1775 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1776 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1777 102 common/cmd_bootm.c Kernel unit name specified 1778 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1779 103 common/cmd_bootm.c Found configuration node 1780 104 common/cmd_bootm.c Got kernel subimage node offset 1781 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1782 105 common/cmd_bootm.c Kernel subimage hash verification OK 1783 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1784 106 common/cmd_bootm.c Architecture check OK 1785 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1786 107 common/cmd_bootm.c Kernel subimge type OK 1787 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1788 108 common/cmd_bootm.c Got kernel subimage data/size 1789 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1790 -109 common/cmd_bootm.c Can't get kernel subimage type 1791 -110 common/cmd_bootm.c Can't get kernel subimage comp 1792 -111 common/cmd_bootm.c Can't get kernel subimage os 1793 -112 common/cmd_bootm.c Can't get kernel subimage load address 1794 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1795 1796 120 common/image.c Start initial ramdisk verification 1797 -120 common/image.c Ramdisk FIT image has incorrect format 1798 121 common/image.c Ramdisk FIT image has correct format 1799 122 common/image.c No Ramdisk subimage unit name, using configuration 1800 -122 common/image.c Can't get configuration for ramdisk subimage 1801 123 common/image.c Ramdisk unit name specified 1802 -124 common/image.c Can't get ramdisk subimage node offset 1803 125 common/image.c Got ramdisk subimage node offset 1804 -125 common/image.c Ramdisk subimage hash verification failed 1805 126 common/image.c Ramdisk subimage hash verification OK 1806 -126 common/image.c Ramdisk subimage for unsupported architecture 1807 127 common/image.c Architecture check OK 1808 -127 common/image.c Can't get ramdisk subimage data/size 1809 128 common/image.c Got ramdisk subimage data/size 1810 129 common/image.c Can't get ramdisk load address 1811 -129 common/image.c Got ramdisk load address 1812 1813 -130 common/cmd_doc.c Icorrect FIT image format 1814 131 common/cmd_doc.c FIT image format OK 1815 1816 -140 common/cmd_ide.c Icorrect FIT image format 1817 141 common/cmd_ide.c FIT image format OK 1818 1819 -150 common/cmd_nand.c Icorrect FIT image format 1820 151 common/cmd_nand.c FIT image format OK 1821 1822 1823Modem Support: 1824-------------- 1825 1826[so far only for SMDK2400 and TRAB boards] 1827 1828- Modem support endable: 1829 CONFIG_MODEM_SUPPORT 1830 1831- RTS/CTS Flow control enable: 1832 CONFIG_HWFLOW 1833 1834- Modem debug support: 1835 CONFIG_MODEM_SUPPORT_DEBUG 1836 1837 Enables debugging stuff (char screen[1024], dbg()) 1838 for modem support. Useful only with BDI2000. 1839 1840- Interrupt support (PPC): 1841 1842 There are common interrupt_init() and timer_interrupt() 1843 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1844 for cpu specific initialization. interrupt_init_cpu() 1845 should set decrementer_count to appropriate value. If 1846 cpu resets decrementer automatically after interrupt 1847 (ppc4xx) it should set decrementer_count to zero. 1848 timer_interrupt() calls timer_interrupt_cpu() for cpu 1849 specific handling. If board has watchdog / status_led 1850 / other_activity_monitor it works automatically from 1851 general timer_interrupt(). 1852 1853- General: 1854 1855 In the target system modem support is enabled when a 1856 specific key (key combination) is pressed during 1857 power-on. Otherwise U-Boot will boot normally 1858 (autoboot). The key_pressed() fuction is called from 1859 board_init(). Currently key_pressed() is a dummy 1860 function, returning 1 and thus enabling modem 1861 initialization. 1862 1863 If there are no modem init strings in the 1864 environment, U-Boot proceed to autoboot; the 1865 previous output (banner, info printfs) will be 1866 supressed, though. 1867 1868 See also: doc/README.Modem 1869 1870 1871Configuration Settings: 1872----------------------- 1873 1874- CFG_LONGHELP: Defined when you want long help messages included; 1875 undefine this when you're short of memory. 1876 1877- CFG_PROMPT: This is what U-Boot prints on the console to 1878 prompt for user input. 1879 1880- CFG_CBSIZE: Buffer size for input from the Console 1881 1882- CFG_PBSIZE: Buffer size for Console output 1883 1884- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1885 1886- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1887 the application (usually a Linux kernel) when it is 1888 booted 1889 1890- CFG_BAUDRATE_TABLE: 1891 List of legal baudrate settings for this board. 1892 1893- CFG_CONSOLE_INFO_QUIET 1894 Suppress display of console information at boot. 1895 1896- CFG_CONSOLE_IS_IN_ENV 1897 If the board specific function 1898 extern int overwrite_console (void); 1899 returns 1, the stdin, stderr and stdout are switched to the 1900 serial port, else the settings in the environment are used. 1901 1902- CFG_CONSOLE_OVERWRITE_ROUTINE 1903 Enable the call to overwrite_console(). 1904 1905- CFG_CONSOLE_ENV_OVERWRITE 1906 Enable overwrite of previous console environment settings. 1907 1908- CFG_MEMTEST_START, CFG_MEMTEST_END: 1909 Begin and End addresses of the area used by the 1910 simple memory test. 1911 1912- CFG_ALT_MEMTEST: 1913 Enable an alternate, more extensive memory test. 1914 1915- CFG_MEMTEST_SCRATCH: 1916 Scratch address used by the alternate memory test 1917 You only need to set this if address zero isn't writeable 1918 1919- CFG_TFTP_LOADADDR: 1920 Default load address for network file downloads 1921 1922- CFG_LOADS_BAUD_CHANGE: 1923 Enable temporary baudrate change while serial download 1924 1925- CFG_SDRAM_BASE: 1926 Physical start address of SDRAM. _Must_ be 0 here. 1927 1928- CFG_MBIO_BASE: 1929 Physical start address of Motherboard I/O (if using a 1930 Cogent motherboard) 1931 1932- CFG_FLASH_BASE: 1933 Physical start address of Flash memory. 1934 1935- CFG_MONITOR_BASE: 1936 Physical start address of boot monitor code (set by 1937 make config files to be same as the text base address 1938 (TEXT_BASE) used when linking) - same as 1939 CFG_FLASH_BASE when booting from flash. 1940 1941- CFG_MONITOR_LEN: 1942 Size of memory reserved for monitor code, used to 1943 determine _at_compile_time_ (!) if the environment is 1944 embedded within the U-Boot image, or in a separate 1945 flash sector. 1946 1947- CFG_MALLOC_LEN: 1948 Size of DRAM reserved for malloc() use. 1949 1950- CFG_BOOTM_LEN: 1951 Normally compressed uImages are limited to an 1952 uncompressed size of 8 MBytes. If this is not enough, 1953 you can define CFG_BOOTM_LEN in your board config file 1954 to adjust this setting to your needs. 1955 1956- CFG_BOOTMAPSZ: 1957 Maximum size of memory mapped by the startup code of 1958 the Linux kernel; all data that must be processed by 1959 the Linux kernel (bd_info, boot arguments, eventually 1960 initrd image) must be put below this limit. 1961 1962- CFG_MAX_FLASH_BANKS: 1963 Max number of Flash memory banks 1964 1965- CFG_MAX_FLASH_SECT: 1966 Max number of sectors on a Flash chip 1967 1968- CFG_FLASH_ERASE_TOUT: 1969 Timeout for Flash erase operations (in ms) 1970 1971- CFG_FLASH_WRITE_TOUT: 1972 Timeout for Flash write operations (in ms) 1973 1974- CFG_FLASH_LOCK_TOUT 1975 Timeout for Flash set sector lock bit operation (in ms) 1976 1977- CFG_FLASH_UNLOCK_TOUT 1978 Timeout for Flash clear lock bits operation (in ms) 1979 1980- CFG_FLASH_PROTECTION 1981 If defined, hardware flash sectors protection is used 1982 instead of U-Boot software protection. 1983 1984- CFG_DIRECT_FLASH_TFTP: 1985 1986 Enable TFTP transfers directly to flash memory; 1987 without this option such a download has to be 1988 performed in two steps: (1) download to RAM, and (2) 1989 copy from RAM to flash. 1990 1991 The two-step approach is usually more reliable, since 1992 you can check if the download worked before you erase 1993 the flash, but in some situations (when sytem RAM is 1994 too limited to allow for a tempory copy of the 1995 downloaded image) this option may be very useful. 1996 1997- CFG_FLASH_CFI: 1998 Define if the flash driver uses extra elements in the 1999 common flash structure for storing flash geometry. 2000 2001- CFG_FLASH_CFI_DRIVER 2002 This option also enables the building of the cfi_flash driver 2003 in the drivers directory 2004 2005- CFG_FLASH_QUIET_TEST 2006 If this option is defined, the common CFI flash doesn't 2007 print it's warning upon not recognized FLASH banks. This 2008 is useful, if some of the configured banks are only 2009 optionally available. 2010 2011- CONFIG_FLASH_SHOW_PROGRESS 2012 If defined (must be an integer), print out countdown 2013 digits and dots. Recommended value: 45 (9..1) for 80 2014 column displays, 15 (3..1) for 40 column displays. 2015 2016- CFG_RX_ETH_BUFFER: 2017 Defines the number of ethernet receive buffers. On some 2018 ethernet controllers it is recommended to set this value 2019 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2020 buffers can be full shortly after enabling the interface 2021 on high ethernet traffic. 2022 Defaults to 4 if not defined. 2023 2024The following definitions that deal with the placement and management 2025of environment data (variable area); in general, we support the 2026following configurations: 2027 2028- CFG_ENV_IS_IN_FLASH: 2029 2030 Define this if the environment is in flash memory. 2031 2032 a) The environment occupies one whole flash sector, which is 2033 "embedded" in the text segment with the U-Boot code. This 2034 happens usually with "bottom boot sector" or "top boot 2035 sector" type flash chips, which have several smaller 2036 sectors at the start or the end. For instance, such a 2037 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2038 such a case you would place the environment in one of the 2039 4 kB sectors - with U-Boot code before and after it. With 2040 "top boot sector" type flash chips, you would put the 2041 environment in one of the last sectors, leaving a gap 2042 between U-Boot and the environment. 2043 2044 - CFG_ENV_OFFSET: 2045 2046 Offset of environment data (variable area) to the 2047 beginning of flash memory; for instance, with bottom boot 2048 type flash chips the second sector can be used: the offset 2049 for this sector is given here. 2050 2051 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2052 2053 - CFG_ENV_ADDR: 2054 2055 This is just another way to specify the start address of 2056 the flash sector containing the environment (instead of 2057 CFG_ENV_OFFSET). 2058 2059 - CFG_ENV_SECT_SIZE: 2060 2061 Size of the sector containing the environment. 2062 2063 2064 b) Sometimes flash chips have few, equal sized, BIG sectors. 2065 In such a case you don't want to spend a whole sector for 2066 the environment. 2067 2068 - CFG_ENV_SIZE: 2069 2070 If you use this in combination with CFG_ENV_IS_IN_FLASH 2071 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2072 of this flash sector for the environment. This saves 2073 memory for the RAM copy of the environment. 2074 2075 It may also save flash memory if you decide to use this 2076 when your environment is "embedded" within U-Boot code, 2077 since then the remainder of the flash sector could be used 2078 for U-Boot code. It should be pointed out that this is 2079 STRONGLY DISCOURAGED from a robustness point of view: 2080 updating the environment in flash makes it always 2081 necessary to erase the WHOLE sector. If something goes 2082 wrong before the contents has been restored from a copy in 2083 RAM, your target system will be dead. 2084 2085 - CFG_ENV_ADDR_REDUND 2086 CFG_ENV_SIZE_REDUND 2087 2088 These settings describe a second storage area used to hold 2089 a redundand copy of the environment data, so that there is 2090 a valid backup copy in case there is a power failure during 2091 a "saveenv" operation. 2092 2093BE CAREFUL! Any changes to the flash layout, and some changes to the 2094source code will make it necessary to adapt <board>/u-boot.lds* 2095accordingly! 2096 2097 2098- CFG_ENV_IS_IN_NVRAM: 2099 2100 Define this if you have some non-volatile memory device 2101 (NVRAM, battery buffered SRAM) which you want to use for the 2102 environment. 2103 2104 - CFG_ENV_ADDR: 2105 - CFG_ENV_SIZE: 2106 2107 These two #defines are used to determin the memory area you 2108 want to use for environment. It is assumed that this memory 2109 can just be read and written to, without any special 2110 provision. 2111 2112BE CAREFUL! The first access to the environment happens quite early 2113in U-Boot initalization (when we try to get the setting of for the 2114console baudrate). You *MUST* have mappend your NVRAM area then, or 2115U-Boot will hang. 2116 2117Please note that even with NVRAM we still use a copy of the 2118environment in RAM: we could work on NVRAM directly, but we want to 2119keep settings there always unmodified except somebody uses "saveenv" 2120to save the current settings. 2121 2122 2123- CFG_ENV_IS_IN_EEPROM: 2124 2125 Use this if you have an EEPROM or similar serial access 2126 device and a driver for it. 2127 2128 - CFG_ENV_OFFSET: 2129 - CFG_ENV_SIZE: 2130 2131 These two #defines specify the offset and size of the 2132 environment area within the total memory of your EEPROM. 2133 2134 - CFG_I2C_EEPROM_ADDR: 2135 If defined, specified the chip address of the EEPROM device. 2136 The default address is zero. 2137 2138 - CFG_EEPROM_PAGE_WRITE_BITS: 2139 If defined, the number of bits used to address bytes in a 2140 single page in the EEPROM device. A 64 byte page, for example 2141 would require six bits. 2142 2143 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2144 If defined, the number of milliseconds to delay between 2145 page writes. The default is zero milliseconds. 2146 2147 - CFG_I2C_EEPROM_ADDR_LEN: 2148 The length in bytes of the EEPROM memory array address. Note 2149 that this is NOT the chip address length! 2150 2151 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2152 EEPROM chips that implement "address overflow" are ones 2153 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2154 address and the extra bits end up in the "chip address" bit 2155 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2156 byte chips. 2157 2158 Note that we consider the length of the address field to 2159 still be one byte because the extra address bits are hidden 2160 in the chip address. 2161 2162 - CFG_EEPROM_SIZE: 2163 The size in bytes of the EEPROM device. 2164 2165 2166- CFG_ENV_IS_IN_DATAFLASH: 2167 2168 Define this if you have a DataFlash memory device which you 2169 want to use for the environment. 2170 2171 - CFG_ENV_OFFSET: 2172 - CFG_ENV_ADDR: 2173 - CFG_ENV_SIZE: 2174 2175 These three #defines specify the offset and size of the 2176 environment area within the total memory of your DataFlash placed 2177 at the specified address. 2178 2179- CFG_ENV_IS_IN_NAND: 2180 2181 Define this if you have a NAND device which you want to use 2182 for the environment. 2183 2184 - CFG_ENV_OFFSET: 2185 - CFG_ENV_SIZE: 2186 2187 These two #defines specify the offset and size of the environment 2188 area within the first NAND device. 2189 2190 - CFG_ENV_OFFSET_REDUND 2191 2192 This setting describes a second storage area of CFG_ENV_SIZE 2193 size used to hold a redundant copy of the environment data, 2194 so that there is a valid backup copy in case there is a 2195 power failure during a "saveenv" operation. 2196 2197 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2198 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2199 the NAND devices block size. 2200 2201- CFG_SPI_INIT_OFFSET 2202 2203 Defines offset to the initial SPI buffer area in DPRAM. The 2204 area is used at an early stage (ROM part) if the environment 2205 is configured to reside in the SPI EEPROM: We need a 520 byte 2206 scratch DPRAM area. It is used between the two initialization 2207 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2208 to be a good choice since it makes it far enough from the 2209 start of the data area as well as from the stack pointer. 2210 2211Please note that the environment is read-only until the monitor 2212has been relocated to RAM and a RAM copy of the environment has been 2213created; also, when using EEPROM you will have to use getenv_r() 2214until then to read environment variables. 2215 2216The environment is protected by a CRC32 checksum. Before the monitor 2217is relocated into RAM, as a result of a bad CRC you will be working 2218with the compiled-in default environment - *silently*!!! [This is 2219necessary, because the first environment variable we need is the 2220"baudrate" setting for the console - if we have a bad CRC, we don't 2221have any device yet where we could complain.] 2222 2223Note: once the monitor has been relocated, then it will complain if 2224the default environment is used; a new CRC is computed as soon as you 2225use the "saveenv" command to store a valid environment. 2226 2227- CFG_FAULT_ECHO_LINK_DOWN: 2228 Echo the inverted Ethernet link state to the fault LED. 2229 2230 Note: If this option is active, then CFG_FAULT_MII_ADDR 2231 also needs to be defined. 2232 2233- CFG_FAULT_MII_ADDR: 2234 MII address of the PHY to check for the Ethernet link state. 2235 2236- CFG_64BIT_VSPRINTF: 2237 Makes vsprintf (and all *printf functions) support printing 2238 of 64bit values by using the L quantifier 2239 2240- CFG_64BIT_STRTOUL: 2241 Adds simple_strtoull that returns a 64bit value 2242 2243Low Level (hardware related) configuration options: 2244--------------------------------------------------- 2245 2246- CFG_CACHELINE_SIZE: 2247 Cache Line Size of the CPU. 2248 2249- CFG_DEFAULT_IMMR: 2250 Default address of the IMMR after system reset. 2251 2252 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2253 and RPXsuper) to be able to adjust the position of 2254 the IMMR register after a reset. 2255 2256- Floppy Disk Support: 2257 CFG_FDC_DRIVE_NUMBER 2258 2259 the default drive number (default value 0) 2260 2261 CFG_ISA_IO_STRIDE 2262 2263 defines the spacing between fdc chipset registers 2264 (default value 1) 2265 2266 CFG_ISA_IO_OFFSET 2267 2268 defines the offset of register from address. It 2269 depends on which part of the data bus is connected to 2270 the fdc chipset. (default value 0) 2271 2272 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2273 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2274 default value. 2275 2276 if CFG_FDC_HW_INIT is defined, then the function 2277 fdc_hw_init() is called at the beginning of the FDC 2278 setup. fdc_hw_init() must be provided by the board 2279 source code. It is used to make hardware dependant 2280 initializations. 2281 2282- CFG_IMMR: Physical address of the Internal Memory. 2283 DO NOT CHANGE unless you know exactly what you're 2284 doing! (11-4) [MPC8xx/82xx systems only] 2285 2286- CFG_INIT_RAM_ADDR: 2287 2288 Start address of memory area that can be used for 2289 initial data and stack; please note that this must be 2290 writable memory that is working WITHOUT special 2291 initialization, i. e. you CANNOT use normal RAM which 2292 will become available only after programming the 2293 memory controller and running certain initialization 2294 sequences. 2295 2296 U-Boot uses the following memory types: 2297 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2298 - MPC824X: data cache 2299 - PPC4xx: data cache 2300 2301- CFG_GBL_DATA_OFFSET: 2302 2303 Offset of the initial data structure in the memory 2304 area defined by CFG_INIT_RAM_ADDR. Usually 2305 CFG_GBL_DATA_OFFSET is chosen such that the initial 2306 data is located at the end of the available space 2307 (sometimes written as (CFG_INIT_RAM_END - 2308 CFG_INIT_DATA_SIZE), and the initial stack is just 2309 below that area (growing from (CFG_INIT_RAM_ADDR + 2310 CFG_GBL_DATA_OFFSET) downward. 2311 2312 Note: 2313 On the MPC824X (or other systems that use the data 2314 cache for initial memory) the address chosen for 2315 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2316 point to an otherwise UNUSED address space between 2317 the top of RAM and the start of the PCI space. 2318 2319- CFG_SIUMCR: SIU Module Configuration (11-6) 2320 2321- CFG_SYPCR: System Protection Control (11-9) 2322 2323- CFG_TBSCR: Time Base Status and Control (11-26) 2324 2325- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2326 2327- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2328 2329- CFG_SCCR: System Clock and reset Control Register (15-27) 2330 2331- CFG_OR_TIMING_SDRAM: 2332 SDRAM timing 2333 2334- CFG_MAMR_PTA: 2335 periodic timer for refresh 2336 2337- CFG_DER: Debug Event Register (37-47) 2338 2339- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2340 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2341 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2342 CFG_BR1_PRELIM: 2343 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2344 2345- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2346 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2347 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2348 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2349 2350- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2351 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2352 Machine Mode Register and Memory Periodic Timer 2353 Prescaler definitions (SDRAM timing) 2354 2355- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2356 enable I2C microcode relocation patch (MPC8xx); 2357 define relocation offset in DPRAM [DSP2] 2358 2359- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2360 enable SMC microcode relocation patch (MPC8xx); 2361 define relocation offset in DPRAM [SMC1] 2362 2363- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2364 enable SPI microcode relocation patch (MPC8xx); 2365 define relocation offset in DPRAM [SCC4] 2366 2367- CFG_USE_OSCCLK: 2368 Use OSCM clock mode on MBX8xx board. Be careful, 2369 wrong setting might damage your board. Read 2370 doc/README.MBX before setting this variable! 2371 2372- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2373 Offset of the bootmode word in DPRAM used by post 2374 (Power On Self Tests). This definition overrides 2375 #define'd default value in commproc.h resp. 2376 cpm_8260.h. 2377 2378- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2379 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2380 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2381 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2382 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2383 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2384 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2385 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2386 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2387 2388- CONFIG_SPD_EEPROM 2389 Get DDR timing information from an I2C EEPROM. Common 2390 with pluggable memory modules such as SODIMMs 2391 2392 SPD_EEPROM_ADDRESS 2393 I2C address of the SPD EEPROM 2394 2395- CFG_SPD_BUS_NUM 2396 If SPD EEPROM is on an I2C bus other than the first 2397 one, specify here. Note that the value must resolve 2398 to something your driver can deal with. 2399 2400- CFG_83XX_DDR_USES_CS0 2401 Only for 83xx systems. If specified, then DDR should 2402 be configured using CS0 and CS1 instead of CS2 and CS3. 2403 2404- CFG_83XX_DDR_USES_CS0 2405 Only for 83xx systems. If specified, then DDR should 2406 be configured using CS0 and CS1 instead of CS2 and CS3. 2407 2408- CONFIG_ETHER_ON_FEC[12] 2409 Define to enable FEC[12] on a 8xx series processor. 2410 2411- CONFIG_FEC[12]_PHY 2412 Define to the hardcoded PHY address which corresponds 2413 to the given FEC; i. e. 2414 #define CONFIG_FEC1_PHY 4 2415 means that the PHY with address 4 is connected to FEC1 2416 2417 When set to -1, means to probe for first available. 2418 2419- CONFIG_FEC[12]_PHY_NORXERR 2420 The PHY does not have a RXERR line (RMII only). 2421 (so program the FEC to ignore it). 2422 2423- CONFIG_RMII 2424 Enable RMII mode for all FECs. 2425 Note that this is a global option, we can't 2426 have one FEC in standard MII mode and another in RMII mode. 2427 2428- CONFIG_CRC32_VERIFY 2429 Add a verify option to the crc32 command. 2430 The syntax is: 2431 2432 => crc32 -v <address> <count> <crc32> 2433 2434 Where address/count indicate a memory area 2435 and crc32 is the correct crc32 which the 2436 area should have. 2437 2438- CONFIG_LOOPW 2439 Add the "loopw" memory command. This only takes effect if 2440 the memory commands are activated globally (CONFIG_CMD_MEM). 2441 2442- CONFIG_MX_CYCLIC 2443 Add the "mdc" and "mwc" memory commands. These are cyclic 2444 "md/mw" commands. 2445 Examples: 2446 2447 => mdc.b 10 4 500 2448 This command will print 4 bytes (10,11,12,13) each 500 ms. 2449 2450 => mwc.l 100 12345678 10 2451 This command will write 12345678 to address 100 all 10 ms. 2452 2453 This only takes effect if the memory commands are activated 2454 globally (CONFIG_CMD_MEM). 2455 2456- CONFIG_SKIP_LOWLEVEL_INIT 2457- CONFIG_SKIP_RELOCATE_UBOOT 2458 2459 [ARM only] If these variables are defined, then 2460 certain low level initializations (like setting up 2461 the memory controller) are omitted and/or U-Boot does 2462 not relocate itself into RAM. 2463 Normally these variables MUST NOT be defined. The 2464 only exception is when U-Boot is loaded (to RAM) by 2465 some other boot loader or by a debugger which 2466 performs these intializations itself. 2467 2468 2469Building the Software: 2470====================== 2471 2472Building U-Boot has been tested in several native build environments 2473and in many different cross environments. Of course we cannot support 2474all possibly existing versions of cross development tools in all 2475(potentially obsolete) versions. In case of tool chain problems we 2476recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2477which is extensively used to build and test U-Boot. 2478 2479If you are not using a native environment, it is assumed that you 2480have GNU cross compiling tools available in your path. In this case, 2481you must set the environment variable CROSS_COMPILE in your shell. 2482Note that no changes to the Makefile or any other source files are 2483necessary. For example using the ELDK on a 4xx CPU, please enter: 2484 2485 $ CROSS_COMPILE=ppc_4xx- 2486 $ export CROSS_COMPILE 2487 2488U-Boot is intended to be simple to build. After installing the 2489sources you must configure U-Boot for one specific board type. This 2490is done by typing: 2491 2492 make NAME_config 2493 2494where "NAME_config" is the name of one of the existing configu- 2495rations; see the main Makefile for supported names. 2496 2497Note: for some board special configuration names may exist; check if 2498 additional information is available from the board vendor; for 2499 instance, the TQM823L systems are available without (standard) 2500 or with LCD support. You can select such additional "features" 2501 when chosing the configuration, i. e. 2502 2503 make TQM823L_config 2504 - will configure for a plain TQM823L, i. e. no LCD support 2505 2506 make TQM823L_LCD_config 2507 - will configure for a TQM823L with U-Boot console on LCD 2508 2509 etc. 2510 2511 2512Finally, type "make all", and you should get some working U-Boot 2513images ready for download to / installation on your system: 2514 2515- "u-boot.bin" is a raw binary image 2516- "u-boot" is an image in ELF binary format 2517- "u-boot.srec" is in Motorola S-Record format 2518 2519By default the build is performed locally and the objects are saved 2520in the source directory. One of the two methods can be used to change 2521this behavior and build U-Boot to some external directory: 2522 25231. Add O= to the make command line invocations: 2524 2525 make O=/tmp/build distclean 2526 make O=/tmp/build NAME_config 2527 make O=/tmp/build all 2528 25292. Set environment variable BUILD_DIR to point to the desired location: 2530 2531 export BUILD_DIR=/tmp/build 2532 make distclean 2533 make NAME_config 2534 make all 2535 2536Note that the command line "O=" setting overrides the BUILD_DIR environment 2537variable. 2538 2539 2540Please be aware that the Makefiles assume you are using GNU make, so 2541for instance on NetBSD you might need to use "gmake" instead of 2542native "make". 2543 2544 2545If the system board that you have is not listed, then you will need 2546to port U-Boot to your hardware platform. To do this, follow these 2547steps: 2548 25491. Add a new configuration option for your board to the toplevel 2550 "Makefile" and to the "MAKEALL" script, using the existing 2551 entries as examples. Note that here and at many other places 2552 boards and other names are listed in alphabetical sort order. Please 2553 keep this order. 25542. Create a new directory to hold your board specific code. Add any 2555 files you need. In your board directory, you will need at least 2556 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25573. Create a new configuration file "include/configs/<board>.h" for 2558 your board 25593. If you're porting U-Boot to a new CPU, then also create a new 2560 directory to hold your CPU specific code. Add any files you need. 25614. Run "make <board>_config" with your new name. 25625. Type "make", and you should get a working "u-boot.srec" file 2563 to be installed on your target system. 25646. Debug and solve any problems that might arise. 2565 [Of course, this last step is much harder than it sounds.] 2566 2567 2568Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2569============================================================== 2570 2571If you have modified U-Boot sources (for instance added a new board 2572or support for new devices, a new CPU, etc.) you are expected to 2573provide feedback to the other developers. The feedback normally takes 2574the form of a "patch", i. e. a context diff against a certain (latest 2575official or latest in the git repository) version of U-Boot sources. 2576 2577But before you submit such a patch, please verify that your modifi- 2578cation did not break existing code. At least make sure that *ALL* of 2579the supported boards compile WITHOUT ANY compiler warnings. To do so, 2580just run the "MAKEALL" script, which will configure and build U-Boot 2581for ALL supported system. Be warned, this will take a while. You can 2582select which (cross) compiler to use by passing a `CROSS_COMPILE' 2583environment variable to the script, i. e. to use the ELDK cross tools 2584you can type 2585 2586 CROSS_COMPILE=ppc_8xx- MAKEALL 2587 2588or to build on a native PowerPC system you can type 2589 2590 CROSS_COMPILE=' ' MAKEALL 2591 2592When using the MAKEALL script, the default behaviour is to build 2593U-Boot in the source directory. This location can be changed by 2594setting the BUILD_DIR environment variable. Also, for each target 2595built, the MAKEALL script saves two log files (<target>.ERR and 2596<target>.MAKEALL) in the <source dir>/LOG directory. This default 2597location can be changed by setting the MAKEALL_LOGDIR environment 2598variable. For example: 2599 2600 export BUILD_DIR=/tmp/build 2601 export MAKEALL_LOGDIR=/tmp/log 2602 CROSS_COMPILE=ppc_8xx- MAKEALL 2603 2604With the above settings build objects are saved in the /tmp/build, 2605log files are saved in the /tmp/log and the source tree remains clean 2606during the whole build process. 2607 2608 2609See also "U-Boot Porting Guide" below. 2610 2611 2612Monitor Commands - Overview: 2613============================ 2614 2615go - start application at address 'addr' 2616run - run commands in an environment variable 2617bootm - boot application image from memory 2618bootp - boot image via network using BootP/TFTP protocol 2619tftpboot- boot image via network using TFTP protocol 2620 and env variables "ipaddr" and "serverip" 2621 (and eventually "gatewayip") 2622rarpboot- boot image via network using RARP/TFTP protocol 2623diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2624loads - load S-Record file over serial line 2625loadb - load binary file over serial line (kermit mode) 2626md - memory display 2627mm - memory modify (auto-incrementing) 2628nm - memory modify (constant address) 2629mw - memory write (fill) 2630cp - memory copy 2631cmp - memory compare 2632crc32 - checksum calculation 2633imd - i2c memory display 2634imm - i2c memory modify (auto-incrementing) 2635inm - i2c memory modify (constant address) 2636imw - i2c memory write (fill) 2637icrc32 - i2c checksum calculation 2638iprobe - probe to discover valid I2C chip addresses 2639iloop - infinite loop on address range 2640isdram - print SDRAM configuration information 2641sspi - SPI utility commands 2642base - print or set address offset 2643printenv- print environment variables 2644setenv - set environment variables 2645saveenv - save environment variables to persistent storage 2646protect - enable or disable FLASH write protection 2647erase - erase FLASH memory 2648flinfo - print FLASH memory information 2649bdinfo - print Board Info structure 2650iminfo - print header information for application image 2651coninfo - print console devices and informations 2652ide - IDE sub-system 2653loop - infinite loop on address range 2654loopw - infinite write loop on address range 2655mtest - simple RAM test 2656icache - enable or disable instruction cache 2657dcache - enable or disable data cache 2658reset - Perform RESET of the CPU 2659echo - echo args to console 2660version - print monitor version 2661help - print online help 2662? - alias for 'help' 2663 2664 2665Monitor Commands - Detailed Description: 2666======================================== 2667 2668TODO. 2669 2670For now: just type "help <command>". 2671 2672 2673Environment Variables: 2674====================== 2675 2676U-Boot supports user configuration using Environment Variables which 2677can be made persistent by saving to Flash memory. 2678 2679Environment Variables are set using "setenv", printed using 2680"printenv", and saved to Flash using "saveenv". Using "setenv" 2681without a value can be used to delete a variable from the 2682environment. As long as you don't save the environment you are 2683working with an in-memory copy. In case the Flash area containing the 2684environment is erased by accident, a default environment is provided. 2685 2686Some configuration options can be set using Environment Variables: 2687 2688 baudrate - see CONFIG_BAUDRATE 2689 2690 bootdelay - see CONFIG_BOOTDELAY 2691 2692 bootcmd - see CONFIG_BOOTCOMMAND 2693 2694 bootargs - Boot arguments when booting an RTOS image 2695 2696 bootfile - Name of the image to load with TFTP 2697 2698 autoload - if set to "no" (any string beginning with 'n'), 2699 "bootp" will just load perform a lookup of the 2700 configuration from the BOOTP server, but not try to 2701 load any image using TFTP 2702 2703 autoscript - if set to "yes" commands like "loadb", "loady", 2704 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2705 to automatically run script images (by internally 2706 calling "autoscript"). 2707 2708 autoscript_uname - if script image is in a format (FIT) this 2709 variable is used to get script subimage unit name. 2710 2711 autostart - if set to "yes", an image loaded using the "bootp", 2712 "rarpboot", "tftpboot" or "diskboot" commands will 2713 be automatically started (by internally calling 2714 "bootm") 2715 2716 If set to "no", a standalone image passed to the 2717 "bootm" command will be copied to the load address 2718 (and eventually uncompressed), but NOT be started. 2719 This can be used to load and uncompress arbitrary 2720 data. 2721 2722 i2cfast - (PPC405GP|PPC405EP only) 2723 if set to 'y' configures Linux I2C driver for fast 2724 mode (400kHZ). This environment variable is used in 2725 initialization code. So, for changes to be effective 2726 it must be saved and board must be reset. 2727 2728 initrd_high - restrict positioning of initrd images: 2729 If this variable is not set, initrd images will be 2730 copied to the highest possible address in RAM; this 2731 is usually what you want since it allows for 2732 maximum initrd size. If for some reason you want to 2733 make sure that the initrd image is loaded below the 2734 CFG_BOOTMAPSZ limit, you can set this environment 2735 variable to a value of "no" or "off" or "0". 2736 Alternatively, you can set it to a maximum upper 2737 address to use (U-Boot will still check that it 2738 does not overwrite the U-Boot stack and data). 2739 2740 For instance, when you have a system with 16 MB 2741 RAM, and want to reserve 4 MB from use by Linux, 2742 you can do this by adding "mem=12M" to the value of 2743 the "bootargs" variable. However, now you must make 2744 sure that the initrd image is placed in the first 2745 12 MB as well - this can be done with 2746 2747 setenv initrd_high 00c00000 2748 2749 If you set initrd_high to 0xFFFFFFFF, this is an 2750 indication to U-Boot that all addresses are legal 2751 for the Linux kernel, including addresses in flash 2752 memory. In this case U-Boot will NOT COPY the 2753 ramdisk at all. This may be useful to reduce the 2754 boot time on your system, but requires that this 2755 feature is supported by your Linux kernel. 2756 2757 ipaddr - IP address; needed for tftpboot command 2758 2759 loadaddr - Default load address for commands like "bootp", 2760 "rarpboot", "tftpboot", "loadb" or "diskboot" 2761 2762 loads_echo - see CONFIG_LOADS_ECHO 2763 2764 serverip - TFTP server IP address; needed for tftpboot command 2765 2766 bootretry - see CONFIG_BOOT_RETRY_TIME 2767 2768 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2769 2770 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2771 2772 ethprime - When CONFIG_NET_MULTI is enabled controls which 2773 interface is used first. 2774 2775 ethact - When CONFIG_NET_MULTI is enabled controls which 2776 interface is currently active. For example you 2777 can do the following 2778 2779 => setenv ethact FEC ETHERNET 2780 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2781 => setenv ethact SCC ETHERNET 2782 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2783 2784 ethrotate - When set to "no" U-Boot does not go through all 2785 available network interfaces. 2786 It just stays at the currently selected interface. 2787 2788 netretry - When set to "no" each network operation will 2789 either succeed or fail without retrying. 2790 When set to "once" the network operation will 2791 fail when all the available network interfaces 2792 are tried once without success. 2793 Useful on scripts which control the retry operation 2794 themselves. 2795 2796 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2797 if set load address for the npe microcode 2798 2799 tftpsrcport - If this is set, the value is used for TFTP's 2800 UDP source port. 2801 2802 tftpdstport - If this is set, the value is used for TFTP's UDP 2803 destination port instead of the Well Know Port 69. 2804 2805 vlan - When set to a value < 4095 the traffic over 2806 ethernet is encapsulated/received over 802.1q 2807 VLAN tagged frames. 2808 2809The following environment variables may be used and automatically 2810updated by the network boot commands ("bootp" and "rarpboot"), 2811depending the information provided by your boot server: 2812 2813 bootfile - see above 2814 dnsip - IP address of your Domain Name Server 2815 dnsip2 - IP address of your secondary Domain Name Server 2816 gatewayip - IP address of the Gateway (Router) to use 2817 hostname - Target hostname 2818 ipaddr - see above 2819 netmask - Subnet Mask 2820 rootpath - Pathname of the root filesystem on the NFS server 2821 serverip - see above 2822 2823 2824There are two special Environment Variables: 2825 2826 serial# - contains hardware identification information such 2827 as type string and/or serial number 2828 ethaddr - Ethernet address 2829 2830These variables can be set only once (usually during manufacturing of 2831the board). U-Boot refuses to delete or overwrite these variables 2832once they have been set once. 2833 2834 2835Further special Environment Variables: 2836 2837 ver - Contains the U-Boot version string as printed 2838 with the "version" command. This variable is 2839 readonly (see CONFIG_VERSION_VARIABLE). 2840 2841 2842Please note that changes to some configuration parameters may take 2843only effect after the next boot (yes, that's just like Windoze :-). 2844 2845 2846Command Line Parsing: 2847===================== 2848 2849There are two different command line parsers available with U-Boot: 2850the old "simple" one, and the much more powerful "hush" shell: 2851 2852Old, simple command line parser: 2853-------------------------------- 2854 2855- supports environment variables (through setenv / saveenv commands) 2856- several commands on one line, separated by ';' 2857- variable substitution using "... ${name} ..." syntax 2858- special characters ('$', ';') can be escaped by prefixing with '\', 2859 for example: 2860 setenv bootcmd bootm \${address} 2861- You can also escape text by enclosing in single apostrophes, for example: 2862 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2863 2864Hush shell: 2865----------- 2866 2867- similar to Bourne shell, with control structures like 2868 if...then...else...fi, for...do...done; while...do...done, 2869 until...do...done, ... 2870- supports environment ("global") variables (through setenv / saveenv 2871 commands) and local shell variables (through standard shell syntax 2872 "name=value"); only environment variables can be used with "run" 2873 command 2874 2875General rules: 2876-------------- 2877 2878(1) If a command line (or an environment variable executed by a "run" 2879 command) contains several commands separated by semicolon, and 2880 one of these commands fails, then the remaining commands will be 2881 executed anyway. 2882 2883(2) If you execute several variables with one call to run (i. e. 2884 calling run with a list af variables as arguments), any failing 2885 command will cause "run" to terminate, i. e. the remaining 2886 variables are not executed. 2887 2888Note for Redundant Ethernet Interfaces: 2889======================================= 2890 2891Some boards come with redundant ethernet interfaces; U-Boot supports 2892such configurations and is capable of automatic selection of a 2893"working" interface when needed. MAC assignment works as follows: 2894 2895Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2896MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2897"eth1addr" (=>eth1), "eth2addr", ... 2898 2899If the network interface stores some valid MAC address (for instance 2900in SROM), this is used as default address if there is NO correspon- 2901ding setting in the environment; if the corresponding environment 2902variable is set, this overrides the settings in the card; that means: 2903 2904o If the SROM has a valid MAC address, and there is no address in the 2905 environment, the SROM's address is used. 2906 2907o If there is no valid address in the SROM, and a definition in the 2908 environment exists, then the value from the environment variable is 2909 used. 2910 2911o If both the SROM and the environment contain a MAC address, and 2912 both addresses are the same, this MAC address is used. 2913 2914o If both the SROM and the environment contain a MAC address, and the 2915 addresses differ, the value from the environment is used and a 2916 warning is printed. 2917 2918o If neither SROM nor the environment contain a MAC address, an error 2919 is raised. 2920 2921 2922Image Formats: 2923============== 2924 2925U-Boot is capable of booting (and performing other auxiliary operations on) 2926images in two formats: 2927 2928New uImage format (FIT) 2929----------------------- 2930 2931Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2932to Flattened Device Tree). It allows the use of images with multiple 2933components (several kernels, ramdisks, etc.), with contents protected by 2934SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2935 2936 2937Old uImage format 2938----------------- 2939 2940Old image format is based on binary files which can be basically anything, 2941preceded by a special header; see the definitions in include/image.h for 2942details; basically, the header defines the following image properties: 2943 2944* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2945 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2946 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2947 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2948* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2949 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2950 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2951* Compression Type (uncompressed, gzip, bzip2) 2952* Load Address 2953* Entry Point 2954* Image Name 2955* Image Timestamp 2956 2957The header is marked by a special Magic Number, and both the header 2958and the data portions of the image are secured against corruption by 2959CRC32 checksums. 2960 2961 2962Linux Support: 2963============== 2964 2965Although U-Boot should support any OS or standalone application 2966easily, the main focus has always been on Linux during the design of 2967U-Boot. 2968 2969U-Boot includes many features that so far have been part of some 2970special "boot loader" code within the Linux kernel. Also, any 2971"initrd" images to be used are no longer part of one big Linux image; 2972instead, kernel and "initrd" are separate images. This implementation 2973serves several purposes: 2974 2975- the same features can be used for other OS or standalone 2976 applications (for instance: using compressed images to reduce the 2977 Flash memory footprint) 2978 2979- it becomes much easier to port new Linux kernel versions because 2980 lots of low-level, hardware dependent stuff are done by U-Boot 2981 2982- the same Linux kernel image can now be used with different "initrd" 2983 images; of course this also means that different kernel images can 2984 be run with the same "initrd". This makes testing easier (you don't 2985 have to build a new "zImage.initrd" Linux image when you just 2986 change a file in your "initrd"). Also, a field-upgrade of the 2987 software is easier now. 2988 2989 2990Linux HOWTO: 2991============ 2992 2993Porting Linux to U-Boot based systems: 2994--------------------------------------- 2995 2996U-Boot cannot save you from doing all the necessary modifications to 2997configure the Linux device drivers for use with your target hardware 2998(no, we don't intend to provide a full virtual machine interface to 2999Linux :-). 3000 3001But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3002 3003Just make sure your machine specific header file (for instance 3004include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3005Information structure as we define in include/u-boot.h, and make 3006sure that your definition of IMAP_ADDR uses the same value as your 3007U-Boot configuration in CFG_IMMR. 3008 3009 3010Configuring the Linux kernel: 3011----------------------------- 3012 3013No specific requirements for U-Boot. Make sure you have some root 3014device (initial ramdisk, NFS) for your target system. 3015 3016 3017Building a Linux Image: 3018----------------------- 3019 3020With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3021not used. If you use recent kernel source, a new build target 3022"uImage" will exist which automatically builds an image usable by 3023U-Boot. Most older kernels also have support for a "pImage" target, 3024which was introduced for our predecessor project PPCBoot and uses a 3025100% compatible format. 3026 3027Example: 3028 3029 make TQM850L_config 3030 make oldconfig 3031 make dep 3032 make uImage 3033 3034The "uImage" build target uses a special tool (in 'tools/mkimage') to 3035encapsulate a compressed Linux kernel image with header information, 3036CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3037 3038* build a standard "vmlinux" kernel image (in ELF binary format): 3039 3040* convert the kernel into a raw binary image: 3041 3042 ${CROSS_COMPILE}-objcopy -O binary \ 3043 -R .note -R .comment \ 3044 -S vmlinux linux.bin 3045 3046* compress the binary image: 3047 3048 gzip -9 linux.bin 3049 3050* package compressed binary image for U-Boot: 3051 3052 mkimage -A ppc -O linux -T kernel -C gzip \ 3053 -a 0 -e 0 -n "Linux Kernel Image" \ 3054 -d linux.bin.gz uImage 3055 3056 3057The "mkimage" tool can also be used to create ramdisk images for use 3058with U-Boot, either separated from the Linux kernel image, or 3059combined into one file. "mkimage" encapsulates the images with a 64 3060byte header containing information about target architecture, 3061operating system, image type, compression method, entry points, time 3062stamp, CRC32 checksums, etc. 3063 3064"mkimage" can be called in two ways: to verify existing images and 3065print the header information, or to build new images. 3066 3067In the first form (with "-l" option) mkimage lists the information 3068contained in the header of an existing U-Boot image; this includes 3069checksum verification: 3070 3071 tools/mkimage -l image 3072 -l ==> list image header information 3073 3074The second form (with "-d" option) is used to build a U-Boot image 3075from a "data file" which is used as image payload: 3076 3077 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3078 -n name -d data_file image 3079 -A ==> set architecture to 'arch' 3080 -O ==> set operating system to 'os' 3081 -T ==> set image type to 'type' 3082 -C ==> set compression type 'comp' 3083 -a ==> set load address to 'addr' (hex) 3084 -e ==> set entry point to 'ep' (hex) 3085 -n ==> set image name to 'name' 3086 -d ==> use image data from 'datafile' 3087 3088Right now, all Linux kernels for PowerPC systems use the same load 3089address (0x00000000), but the entry point address depends on the 3090kernel version: 3091 3092- 2.2.x kernels have the entry point at 0x0000000C, 3093- 2.3.x and later kernels have the entry point at 0x00000000. 3094 3095So a typical call to build a U-Boot image would read: 3096 3097 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3098 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3099 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3100 > examples/uImage.TQM850L 3101 Image Name: 2.4.4 kernel for TQM850L 3102 Created: Wed Jul 19 02:34:59 2000 3103 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3104 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3105 Load Address: 0x00000000 3106 Entry Point: 0x00000000 3107 3108To verify the contents of the image (or check for corruption): 3109 3110 -> tools/mkimage -l examples/uImage.TQM850L 3111 Image Name: 2.4.4 kernel for TQM850L 3112 Created: Wed Jul 19 02:34:59 2000 3113 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3114 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3115 Load Address: 0x00000000 3116 Entry Point: 0x00000000 3117 3118NOTE: for embedded systems where boot time is critical you can trade 3119speed for memory and install an UNCOMPRESSED image instead: this 3120needs more space in Flash, but boots much faster since it does not 3121need to be uncompressed: 3122 3123 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3124 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3125 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3126 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3127 > examples/uImage.TQM850L-uncompressed 3128 Image Name: 2.4.4 kernel for TQM850L 3129 Created: Wed Jul 19 02:34:59 2000 3130 Image Type: PowerPC Linux Kernel Image (uncompressed) 3131 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3132 Load Address: 0x00000000 3133 Entry Point: 0x00000000 3134 3135 3136Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3137when your kernel is intended to use an initial ramdisk: 3138 3139 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3140 > -A ppc -O linux -T ramdisk -C gzip \ 3141 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3142 Image Name: Simple Ramdisk Image 3143 Created: Wed Jan 12 14:01:50 2000 3144 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3145 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3146 Load Address: 0x00000000 3147 Entry Point: 0x00000000 3148 3149 3150Installing a Linux Image: 3151------------------------- 3152 3153To downloading a U-Boot image over the serial (console) interface, 3154you must convert the image to S-Record format: 3155 3156 objcopy -I binary -O srec examples/image examples/image.srec 3157 3158The 'objcopy' does not understand the information in the U-Boot 3159image header, so the resulting S-Record file will be relative to 3160address 0x00000000. To load it to a given address, you need to 3161specify the target address as 'offset' parameter with the 'loads' 3162command. 3163 3164Example: install the image to address 0x40100000 (which on the 3165TQM8xxL is in the first Flash bank): 3166 3167 => erase 40100000 401FFFFF 3168 3169 .......... done 3170 Erased 8 sectors 3171 3172 => loads 40100000 3173 ## Ready for S-Record download ... 3174 ~>examples/image.srec 3175 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3176 ... 3177 15989 15990 15991 15992 3178 [file transfer complete] 3179 [connected] 3180 ## Start Addr = 0x00000000 3181 3182 3183You can check the success of the download using the 'iminfo' command; 3184this includes a checksum verification so you can be sure no data 3185corruption happened: 3186 3187 => imi 40100000 3188 3189 ## Checking Image at 40100000 ... 3190 Image Name: 2.2.13 for initrd on TQM850L 3191 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3192 Data Size: 335725 Bytes = 327 kB = 0 MB 3193 Load Address: 00000000 3194 Entry Point: 0000000c 3195 Verifying Checksum ... OK 3196 3197 3198Boot Linux: 3199----------- 3200 3201The "bootm" command is used to boot an application that is stored in 3202memory (RAM or Flash). In case of a Linux kernel image, the contents 3203of the "bootargs" environment variable is passed to the kernel as 3204parameters. You can check and modify this variable using the 3205"printenv" and "setenv" commands: 3206 3207 3208 => printenv bootargs 3209 bootargs=root=/dev/ram 3210 3211 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3212 3213 => printenv bootargs 3214 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3215 3216 => bootm 40020000 3217 ## Booting Linux kernel at 40020000 ... 3218 Image Name: 2.2.13 for NFS on TQM850L 3219 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3220 Data Size: 381681 Bytes = 372 kB = 0 MB 3221 Load Address: 00000000 3222 Entry Point: 0000000c 3223 Verifying Checksum ... OK 3224 Uncompressing Kernel Image ... OK 3225 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 3226 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3227 time_init: decrementer frequency = 187500000/60 3228 Calibrating delay loop... 49.77 BogoMIPS 3229 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3230 ... 3231 3232If you want to boot a Linux kernel with initial ram disk, you pass 3233the memory addresses of both the kernel and the initrd image (PPBCOOT 3234format!) to the "bootm" command: 3235 3236 => imi 40100000 40200000 3237 3238 ## Checking Image at 40100000 ... 3239 Image Name: 2.2.13 for initrd on TQM850L 3240 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3241 Data Size: 335725 Bytes = 327 kB = 0 MB 3242 Load Address: 00000000 3243 Entry Point: 0000000c 3244 Verifying Checksum ... OK 3245 3246 ## Checking Image at 40200000 ... 3247 Image Name: Simple Ramdisk Image 3248 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3249 Data Size: 566530 Bytes = 553 kB = 0 MB 3250 Load Address: 00000000 3251 Entry Point: 00000000 3252 Verifying Checksum ... OK 3253 3254 => bootm 40100000 40200000 3255 ## Booting Linux kernel at 40100000 ... 3256 Image Name: 2.2.13 for initrd on TQM850L 3257 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3258 Data Size: 335725 Bytes = 327 kB = 0 MB 3259 Load Address: 00000000 3260 Entry Point: 0000000c 3261 Verifying Checksum ... OK 3262 Uncompressing Kernel Image ... OK 3263 ## Loading RAMDisk Image at 40200000 ... 3264 Image Name: Simple Ramdisk Image 3265 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3266 Data Size: 566530 Bytes = 553 kB = 0 MB 3267 Load Address: 00000000 3268 Entry Point: 00000000 3269 Verifying Checksum ... OK 3270 Loading Ramdisk ... OK 3271 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 3272 Boot arguments: root=/dev/ram 3273 time_init: decrementer frequency = 187500000/60 3274 Calibrating delay loop... 49.77 BogoMIPS 3275 ... 3276 RAMDISK: Compressed image found at block 0 3277 VFS: Mounted root (ext2 filesystem). 3278 3279 bash# 3280 3281Boot Linux and pass a flat device tree: 3282----------- 3283 3284First, U-Boot must be compiled with the appropriate defines. See the section 3285titled "Linux Kernel Interface" above for a more in depth explanation. The 3286following is an example of how to start a kernel and pass an updated 3287flat device tree: 3288 3289=> print oftaddr 3290oftaddr=0x300000 3291=> print oft 3292oft=oftrees/mpc8540ads.dtb 3293=> tftp $oftaddr $oft 3294Speed: 1000, full duplex 3295Using TSEC0 device 3296TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3297Filename 'oftrees/mpc8540ads.dtb'. 3298Load address: 0x300000 3299Loading: # 3300done 3301Bytes transferred = 4106 (100a hex) 3302=> tftp $loadaddr $bootfile 3303Speed: 1000, full duplex 3304Using TSEC0 device 3305TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3306Filename 'uImage'. 3307Load address: 0x200000 3308Loading:############ 3309done 3310Bytes transferred = 1029407 (fb51f hex) 3311=> print loadaddr 3312loadaddr=200000 3313=> print oftaddr 3314oftaddr=0x300000 3315=> bootm $loadaddr - $oftaddr 3316## Booting image at 00200000 ... 3317 Image Name: Linux-2.6.17-dirty 3318 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3319 Data Size: 1029343 Bytes = 1005.2 kB 3320 Load Address: 00000000 3321 Entry Point: 00000000 3322 Verifying Checksum ... OK 3323 Uncompressing Kernel Image ... OK 3324Booting using flat device tree at 0x300000 3325Using MPC85xx ADS machine description 3326Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3327[snip] 3328 3329 3330More About U-Boot Image Types: 3331------------------------------ 3332 3333U-Boot supports the following image types: 3334 3335 "Standalone Programs" are directly runnable in the environment 3336 provided by U-Boot; it is expected that (if they behave 3337 well) you can continue to work in U-Boot after return from 3338 the Standalone Program. 3339 "OS Kernel Images" are usually images of some Embedded OS which 3340 will take over control completely. Usually these programs 3341 will install their own set of exception handlers, device 3342 drivers, set up the MMU, etc. - this means, that you cannot 3343 expect to re-enter U-Boot except by resetting the CPU. 3344 "RAMDisk Images" are more or less just data blocks, and their 3345 parameters (address, size) are passed to an OS kernel that is 3346 being started. 3347 "Multi-File Images" contain several images, typically an OS 3348 (Linux) kernel image and one or more data images like 3349 RAMDisks. This construct is useful for instance when you want 3350 to boot over the network using BOOTP etc., where the boot 3351 server provides just a single image file, but you want to get 3352 for instance an OS kernel and a RAMDisk image. 3353 3354 "Multi-File Images" start with a list of image sizes, each 3355 image size (in bytes) specified by an "uint32_t" in network 3356 byte order. This list is terminated by an "(uint32_t)0". 3357 Immediately after the terminating 0 follow the images, one by 3358 one, all aligned on "uint32_t" boundaries (size rounded up to 3359 a multiple of 4 bytes). 3360 3361 "Firmware Images" are binary images containing firmware (like 3362 U-Boot or FPGA images) which usually will be programmed to 3363 flash memory. 3364 3365 "Script files" are command sequences that will be executed by 3366 U-Boot's command interpreter; this feature is especially 3367 useful when you configure U-Boot to use a real shell (hush) 3368 as command interpreter. 3369 3370 3371Standalone HOWTO: 3372================= 3373 3374One of the features of U-Boot is that you can dynamically load and 3375run "standalone" applications, which can use some resources of 3376U-Boot like console I/O functions or interrupt services. 3377 3378Two simple examples are included with the sources: 3379 3380"Hello World" Demo: 3381------------------- 3382 3383'examples/hello_world.c' contains a small "Hello World" Demo 3384application; it is automatically compiled when you build U-Boot. 3385It's configured to run at address 0x00040004, so you can play with it 3386like that: 3387 3388 => loads 3389 ## Ready for S-Record download ... 3390 ~>examples/hello_world.srec 3391 1 2 3 4 5 6 7 8 9 10 11 ... 3392 [file transfer complete] 3393 [connected] 3394 ## Start Addr = 0x00040004 3395 3396 => go 40004 Hello World! This is a test. 3397 ## Starting application at 0x00040004 ... 3398 Hello World 3399 argc = 7 3400 argv[0] = "40004" 3401 argv[1] = "Hello" 3402 argv[2] = "World!" 3403 argv[3] = "This" 3404 argv[4] = "is" 3405 argv[5] = "a" 3406 argv[6] = "test." 3407 argv[7] = "<NULL>" 3408 Hit any key to exit ... 3409 3410 ## Application terminated, rc = 0x0 3411 3412Another example, which demonstrates how to register a CPM interrupt 3413handler with the U-Boot code, can be found in 'examples/timer.c'. 3414Here, a CPM timer is set up to generate an interrupt every second. 3415The interrupt service routine is trivial, just printing a '.' 3416character, but this is just a demo program. The application can be 3417controlled by the following keys: 3418 3419 ? - print current values og the CPM Timer registers 3420 b - enable interrupts and start timer 3421 e - stop timer and disable interrupts 3422 q - quit application 3423 3424 => loads 3425 ## Ready for S-Record download ... 3426 ~>examples/timer.srec 3427 1 2 3 4 5 6 7 8 9 10 11 ... 3428 [file transfer complete] 3429 [connected] 3430 ## Start Addr = 0x00040004 3431 3432 => go 40004 3433 ## Starting application at 0x00040004 ... 3434 TIMERS=0xfff00980 3435 Using timer 1 3436 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3437 3438Hit 'b': 3439 [q, b, e, ?] Set interval 1000000 us 3440 Enabling timer 3441Hit '?': 3442 [q, b, e, ?] ........ 3443 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3444Hit '?': 3445 [q, b, e, ?] . 3446 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3447Hit '?': 3448 [q, b, e, ?] . 3449 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3450Hit '?': 3451 [q, b, e, ?] . 3452 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3453Hit 'e': 3454 [q, b, e, ?] ...Stopping timer 3455Hit 'q': 3456 [q, b, e, ?] ## Application terminated, rc = 0x0 3457 3458 3459Minicom warning: 3460================ 3461 3462Over time, many people have reported problems when trying to use the 3463"minicom" terminal emulation program for serial download. I (wd) 3464consider minicom to be broken, and recommend not to use it. Under 3465Unix, I recommend to use C-Kermit for general purpose use (and 3466especially for kermit binary protocol download ("loadb" command), and 3467use "cu" for S-Record download ("loads" command). 3468 3469Nevertheless, if you absolutely want to use it try adding this 3470configuration to your "File transfer protocols" section: 3471 3472 Name Program Name U/D FullScr IO-Red. Multi 3473 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3474 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3475 3476 3477NetBSD Notes: 3478============= 3479 3480Starting at version 0.9.2, U-Boot supports NetBSD both as host 3481(build U-Boot) and target system (boots NetBSD/mpc8xx). 3482 3483Building requires a cross environment; it is known to work on 3484NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3485need gmake since the Makefiles are not compatible with BSD make). 3486Note that the cross-powerpc package does not install include files; 3487attempting to build U-Boot will fail because <machine/ansi.h> is 3488missing. This file has to be installed and patched manually: 3489 3490 # cd /usr/pkg/cross/powerpc-netbsd/include 3491 # mkdir powerpc 3492 # ln -s powerpc machine 3493 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3494 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3495 3496Native builds *don't* work due to incompatibilities between native 3497and U-Boot include files. 3498 3499Booting assumes that (the first part of) the image booted is a 3500stage-2 loader which in turn loads and then invokes the kernel 3501proper. Loader sources will eventually appear in the NetBSD source 3502tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3503meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3504 3505 3506Implementation Internals: 3507========================= 3508 3509The following is not intended to be a complete description of every 3510implementation detail. However, it should help to understand the 3511inner workings of U-Boot and make it easier to port it to custom 3512hardware. 3513 3514 3515Initial Stack, Global Data: 3516--------------------------- 3517 3518The implementation of U-Boot is complicated by the fact that U-Boot 3519starts running out of ROM (flash memory), usually without access to 3520system RAM (because the memory controller is not initialized yet). 3521This means that we don't have writable Data or BSS segments, and BSS 3522is not initialized as zero. To be able to get a C environment working 3523at all, we have to allocate at least a minimal stack. Implementation 3524options for this are defined and restricted by the CPU used: Some CPU 3525models provide on-chip memory (like the IMMR area on MPC8xx and 3526MPC826x processors), on others (parts of) the data cache can be 3527locked as (mis-) used as memory, etc. 3528 3529 Chris Hallinan posted a good summary of these issues to the 3530 u-boot-users mailing list: 3531 3532 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3533 From: "Chris Hallinan" <clh@net1plus.com> 3534 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3535 ... 3536 3537 Correct me if I'm wrong, folks, but the way I understand it 3538 is this: Using DCACHE as initial RAM for Stack, etc, does not 3539 require any physical RAM backing up the cache. The cleverness 3540 is that the cache is being used as a temporary supply of 3541 necessary storage before the SDRAM controller is setup. It's 3542 beyond the scope of this list to expain the details, but you 3543 can see how this works by studying the cache architecture and 3544 operation in the architecture and processor-specific manuals. 3545 3546 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3547 is another option for the system designer to use as an 3548 initial stack/ram area prior to SDRAM being available. Either 3549 option should work for you. Using CS 4 should be fine if your 3550 board designers haven't used it for something that would 3551 cause you grief during the initial boot! It is frequently not 3552 used. 3553 3554 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3555 with your processor/board/system design. The default value 3556 you will find in any recent u-boot distribution in 3557 walnut.h should work for you. I'd set it to a value larger 3558 than your SDRAM module. If you have a 64MB SDRAM module, set 3559 it above 400_0000. Just make sure your board has no resources 3560 that are supposed to respond to that address! That code in 3561 start.S has been around a while and should work as is when 3562 you get the config right. 3563 3564 -Chris Hallinan 3565 DS4.COM, Inc. 3566 3567It is essential to remember this, since it has some impact on the C 3568code for the initialization procedures: 3569 3570* Initialized global data (data segment) is read-only. Do not attempt 3571 to write it. 3572 3573* Do not use any unitialized global data (or implicitely initialized 3574 as zero data - BSS segment) at all - this is undefined, initiali- 3575 zation is performed later (when relocating to RAM). 3576 3577* Stack space is very limited. Avoid big data buffers or things like 3578 that. 3579 3580Having only the stack as writable memory limits means we cannot use 3581normal global data to share information beween the code. But it 3582turned out that the implementation of U-Boot can be greatly 3583simplified by making a global data structure (gd_t) available to all 3584functions. We could pass a pointer to this data as argument to _all_ 3585functions, but this would bloat the code. Instead we use a feature of 3586the GCC compiler (Global Register Variables) to share the data: we 3587place a pointer (gd) to the global data into a register which we 3588reserve for this purpose. 3589 3590When choosing a register for such a purpose we are restricted by the 3591relevant (E)ABI specifications for the current architecture, and by 3592GCC's implementation. 3593 3594For PowerPC, the following registers have specific use: 3595 R1: stack pointer 3596 R2: reserved for system use 3597 R3-R4: parameter passing and return values 3598 R5-R10: parameter passing 3599 R13: small data area pointer 3600 R30: GOT pointer 3601 R31: frame pointer 3602 3603 (U-Boot also uses R14 as internal GOT pointer.) 3604 3605 ==> U-Boot will use R2 to hold a pointer to the global data 3606 3607 Note: on PPC, we could use a static initializer (since the 3608 address of the global data structure is known at compile time), 3609 but it turned out that reserving a register results in somewhat 3610 smaller code - although the code savings are not that big (on 3611 average for all boards 752 bytes for the whole U-Boot image, 3612 624 text + 127 data). 3613 3614On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3615 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3616 3617 ==> U-Boot will use P5 to hold a pointer to the global data 3618 3619On ARM, the following registers are used: 3620 3621 R0: function argument word/integer result 3622 R1-R3: function argument word 3623 R9: GOT pointer 3624 R10: stack limit (used only if stack checking if enabled) 3625 R11: argument (frame) pointer 3626 R12: temporary workspace 3627 R13: stack pointer 3628 R14: link register 3629 R15: program counter 3630 3631 ==> U-Boot will use R8 to hold a pointer to the global data 3632 3633NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3634or current versions of GCC may "optimize" the code too much. 3635 3636Memory Management: 3637------------------ 3638 3639U-Boot runs in system state and uses physical addresses, i.e. the 3640MMU is not used either for address mapping nor for memory protection. 3641 3642The available memory is mapped to fixed addresses using the memory 3643controller. In this process, a contiguous block is formed for each 3644memory type (Flash, SDRAM, SRAM), even when it consists of several 3645physical memory banks. 3646 3647U-Boot is installed in the first 128 kB of the first Flash bank (on 3648TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3649booting and sizing and initializing DRAM, the code relocates itself 3650to the upper end of DRAM. Immediately below the U-Boot code some 3651memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3652configuration setting]. Below that, a structure with global Board 3653Info data is placed, followed by the stack (growing downward). 3654 3655Additionally, some exception handler code is copied to the low 8 kB 3656of DRAM (0x00000000 ... 0x00001FFF). 3657 3658So a typical memory configuration with 16 MB of DRAM could look like 3659this: 3660 3661 0x0000 0000 Exception Vector code 3662 : 3663 0x0000 1FFF 3664 0x0000 2000 Free for Application Use 3665 : 3666 : 3667 3668 : 3669 : 3670 0x00FB FF20 Monitor Stack (Growing downward) 3671 0x00FB FFAC Board Info Data and permanent copy of global data 3672 0x00FC 0000 Malloc Arena 3673 : 3674 0x00FD FFFF 3675 0x00FE 0000 RAM Copy of Monitor Code 3676 ... eventually: LCD or video framebuffer 3677 ... eventually: pRAM (Protected RAM - unchanged by reset) 3678 0x00FF FFFF [End of RAM] 3679 3680 3681System Initialization: 3682---------------------- 3683 3684In the reset configuration, U-Boot starts at the reset entry point 3685(on most PowerPC systens at address 0x00000100). Because of the reset 3686configuration for CS0# this is a mirror of the onboard Flash memory. 3687To be able to re-map memory U-Boot then jumps to its link address. 3688To be able to implement the initialization code in C, a (small!) 3689initial stack is set up in the internal Dual Ported RAM (in case CPUs 3690which provide such a feature like MPC8xx or MPC8260), or in a locked 3691part of the data cache. After that, U-Boot initializes the CPU core, 3692the caches and the SIU. 3693 3694Next, all (potentially) available memory banks are mapped using a 3695preliminary mapping. For example, we put them on 512 MB boundaries 3696(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3697on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3698programmed for SDRAM access. Using the temporary configuration, a 3699simple memory test is run that determines the size of the SDRAM 3700banks. 3701 3702When there is more than one SDRAM bank, and the banks are of 3703different size, the largest is mapped first. For equal size, the first 3704bank (CS2#) is mapped first. The first mapping is always for address 37050x00000000, with any additional banks following immediately to create 3706contiguous memory starting from 0. 3707 3708Then, the monitor installs itself at the upper end of the SDRAM area 3709and allocates memory for use by malloc() and for the global Board 3710Info data; also, the exception vector code is copied to the low RAM 3711pages, and the final stack is set up. 3712 3713Only after this relocation will you have a "normal" C environment; 3714until that you are restricted in several ways, mostly because you are 3715running from ROM, and because the code will have to be relocated to a 3716new address in RAM. 3717 3718 3719U-Boot Porting Guide: 3720---------------------- 3721 3722[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3723list, October 2002] 3724 3725 3726int main (int argc, char *argv[]) 3727{ 3728 sighandler_t no_more_time; 3729 3730 signal (SIGALRM, no_more_time); 3731 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3732 3733 if (available_money > available_manpower) { 3734 pay consultant to port U-Boot; 3735 return 0; 3736 } 3737 3738 Download latest U-Boot source; 3739 3740 Subscribe to u-boot-users mailing list; 3741 3742 if (clueless) { 3743 email ("Hi, I am new to U-Boot, how do I get started?"); 3744 } 3745 3746 while (learning) { 3747 Read the README file in the top level directory; 3748 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3749 Read the source, Luke; 3750 } 3751 3752 if (available_money > toLocalCurrency ($2500)) { 3753 Buy a BDI2000; 3754 } else { 3755 Add a lot of aggravation and time; 3756 } 3757 3758 Create your own board support subdirectory; 3759 3760 Create your own board config file; 3761 3762 while (!running) { 3763 do { 3764 Add / modify source code; 3765 } until (compiles); 3766 Debug; 3767 if (clueless) 3768 email ("Hi, I am having problems..."); 3769 } 3770 Send patch file to Wolfgang; 3771 3772 return 0; 3773} 3774 3775void no_more_time (int sig) 3776{ 3777 hire_a_guru(); 3778} 3779 3780 3781Coding Standards: 3782----------------- 3783 3784All contributions to U-Boot should conform to the Linux kernel 3785coding style; see the file "Documentation/CodingStyle" and the script 3786"scripts/Lindent" in your Linux kernel source directory. In sources 3787originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3788spaces before parameters to function calls) is actually used. 3789 3790Source files originating from a different project (for example the 3791MTD subsystem) are generally exempt from these guidelines and are not 3792reformated to ease subsequent migration to newer versions of those 3793sources. 3794 3795Please note that U-Boot is implemented in C (and to some small parts in 3796Assembler); no C++ is used, so please do not use C++ style comments (//) 3797in your code. 3798 3799Please also stick to the following formatting rules: 3800- remove any trailing white space 3801- use TAB characters for indentation, not spaces 3802- make sure NOT to use DOS '\r\n' line feeds 3803- do not add more than 2 empty lines to source files 3804- do not add trailing empty lines to source files 3805 3806Submissions which do not conform to the standards may be returned 3807with a request to reformat the changes. 3808 3809 3810Submitting Patches: 3811------------------- 3812 3813Since the number of patches for U-Boot is growing, we need to 3814establish some rules. Submissions which do not conform to these rules 3815may be rejected, even when they contain important and valuable stuff. 3816 3817Patches shall be sent to the u-boot-users mailing list. 3818 3819Please see http://www.denx.de/wiki/UBoot/Patches for details. 3820 3821When you send a patch, please include the following information with 3822it: 3823 3824* For bug fixes: a description of the bug and how your patch fixes 3825 this bug. Please try to include a way of demonstrating that the 3826 patch actually fixes something. 3827 3828* For new features: a description of the feature and your 3829 implementation. 3830 3831* A CHANGELOG entry as plaintext (separate from the patch) 3832 3833* For major contributions, your entry to the CREDITS file 3834 3835* When you add support for a new board, don't forget to add this 3836 board to the MAKEALL script, too. 3837 3838* If your patch adds new configuration options, don't forget to 3839 document these in the README file. 3840 3841* The patch itself. If you are using git (which is *strongly* 3842 recommended) you can easily generate the patch using the 3843 "git-format-patch". If you then use "git-send-email" to send it to 3844 the U-Boot mailing list, you will avoid most of the common problems 3845 with some other mail clients. 3846 3847 If you cannot use git, use "diff -purN OLD NEW". If your version of 3848 diff does not support these options, then get the latest version of 3849 GNU diff. 3850 3851 The current directory when running this command shall be the parent 3852 directory of the U-Boot source tree (i. e. please make sure that 3853 your patch includes sufficient directory information for the 3854 affected files). 3855 3856 We prefer patches as plain text. MIME attachments are discouraged, 3857 and compressed attachments must not be used. 3858 3859* If one logical set of modifications affects or creates several 3860 files, all these changes shall be submitted in a SINGLE patch file. 3861 3862* Changesets that contain different, unrelated modifications shall be 3863 submitted as SEPARATE patches, one patch per changeset. 3864 3865 3866Notes: 3867 3868* Before sending the patch, run the MAKEALL script on your patched 3869 source tree and make sure that no errors or warnings are reported 3870 for any of the boards. 3871 3872* Keep your modifications to the necessary minimum: A patch 3873 containing several unrelated changes or arbitrary reformats will be 3874 returned with a request to re-formatting / split it. 3875 3876* If you modify existing code, make sure that your new code does not 3877 add to the memory footprint of the code ;-) Small is beautiful! 3878 When adding new features, these should compile conditionally only 3879 (using #ifdef), and the resulting code with the new feature 3880 disabled must not need more memory than the old code without your 3881 modification. 3882 3883* Remember that there is a size limit of 40 kB per message on the 3884 u-boot-users mailing list. Bigger patches will be moderated. If 3885 they are reasonable and not bigger than 100 kB, they will be 3886 acknowledged. Even bigger patches should be avoided. 3887