1# 2# (C) Copyright 2000 - 2005 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. 55 56 57Where to get help: 58================== 59 60In case you have questions about, problems with or contributions for 61U-Boot you should send a message to the U-Boot mailing list at 62<u-boot-users@lists.sourceforge.net>. There is also an archive of 63previous traffic on the mailing list - please search the archive 64before asking FAQ's. Please see 65http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 66 67 68Where we come from: 69=================== 70 71- start from 8xxrom sources 72- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 73- clean up code 74- make it easier to add custom boards 75- make it possible to add other [PowerPC] CPUs 76- extend functions, especially: 77 * Provide extended interface to Linux boot loader 78 * S-Record download 79 * network boot 80 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 81- create ARMBoot project (http://sourceforge.net/projects/armboot) 82- add other CPU families (starting with ARM) 83- create U-Boot project (http://sourceforge.net/projects/u-boot) 84 85 86Names and Spelling: 87=================== 88 89The "official" name of this project is "Das U-Boot". The spelling 90"U-Boot" shall be used in all written text (documentation, comments 91in source files etc.). Example: 92 93 This is the README file for the U-Boot project. 94 95File names etc. shall be based on the string "u-boot". Examples: 96 97 include/asm-ppc/u-boot.h 98 99 #include <asm/u-boot.h> 100 101Variable names, preprocessor constants etc. shall be either based on 102the string "u_boot" or on "U_BOOT". Example: 103 104 U_BOOT_VERSION u_boot_logo 105 IH_OS_U_BOOT u_boot_hush_start 106 107 108Versioning: 109=========== 110 111U-Boot uses a 3 level version number containing a version, a 112sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 113sub-version "34", and patchlevel "4". 114 115The patchlevel is used to indicate certain stages of development 116between released versions, i. e. officially released versions of 117U-Boot will always have a patchlevel of "0". 118 119 120Directory Hierarchy: 121==================== 122 123- board Board dependent files 124- common Misc architecture independent functions 125- cpu CPU specific files 126 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 127 - arm720t Files specific to ARM 720 CPUs 128 - arm920t Files specific to ARM 920 CPUs 129 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 130 - imx Files specific to Freescale MC9328 i.MX CPUs 131 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 132 - arm925t Files specific to ARM 925 CPUs 133 - arm926ejs Files specific to ARM 926 CPUs 134 - arm1136 Files specific to ARM 1136 CPUs 135 - at32ap Files specific to Atmel AVR32 AP CPUs 136 - i386 Files specific to i386 CPUs 137 - ixp Files specific to Intel XScale IXP CPUs 138 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 139 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 140 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 141 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 142 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 143 - mips Files specific to MIPS CPUs 144 - mpc5xx Files specific to Freescale MPC5xx CPUs 145 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 146 - mpc8xx Files specific to Freescale MPC8xx CPUs 147 - mpc8220 Files specific to Freescale MPC8220 CPUs 148 - mpc824x Files specific to Freescale MPC824x CPUs 149 - mpc8260 Files specific to Freescale MPC8260 CPUs 150 - mpc85xx Files specific to Freescale MPC85xx CPUs 151 - nios Files specific to Altera NIOS CPUs 152 - nios2 Files specific to Altera Nios-II CPUs 153 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 154 - pxa Files specific to Intel XScale PXA CPUs 155 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 156 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 157- disk Code for disk drive partition handling 158- doc Documentation (don't expect too much) 159- drivers Commonly used device drivers 160- dtt Digital Thermometer and Thermostat drivers 161- examples Example code for standalone applications, etc. 162- include Header Files 163- lib_arm Files generic to ARM architecture 164- lib_avr32 Files generic to AVR32 architecture 165- lib_generic Files generic to all architectures 166- lib_i386 Files generic to i386 architecture 167- lib_m68k Files generic to m68k architecture 168- lib_mips Files generic to MIPS architecture 169- lib_nios Files generic to NIOS architecture 170- lib_ppc Files generic to PowerPC architecture 171- libfdt Library files to support flattened device trees 172- net Networking code 173- post Power On Self Test 174- rtc Real Time Clock drivers 175- tools Tools to build S-Record or U-Boot images, etc. 176 177Software Configuration: 178======================= 179 180Configuration is usually done using C preprocessor defines; the 181rationale behind that is to avoid dead code whenever possible. 182 183There are two classes of configuration variables: 184 185* Configuration _OPTIONS_: 186 These are selectable by the user and have names beginning with 187 "CONFIG_". 188 189* Configuration _SETTINGS_: 190 These depend on the hardware etc. and should not be meddled with if 191 you don't know what you're doing; they have names beginning with 192 "CFG_". 193 194Later we will add a configuration tool - probably similar to or even 195identical to what's used for the Linux kernel. Right now, we have to 196do the configuration by hand, which means creating some symbolic 197links and editing some configuration files. We use the TQM8xxL boards 198as an example here. 199 200 201Selection of Processor Architecture and Board Type: 202--------------------------------------------------- 203 204For all supported boards there are ready-to-use default 205configurations available; just type "make <board_name>_config". 206 207Example: For a TQM823L module type: 208 209 cd u-boot 210 make TQM823L_config 211 212For the Cogent platform, you need to specify the cpu type as well; 213e.g. "make cogent_mpc8xx_config". And also configure the cogent 214directory according to the instructions in cogent/README. 215 216 217Configuration Options: 218---------------------- 219 220Configuration depends on the combination of board and CPU type; all 221such information is kept in a configuration file 222"include/configs/<board_name>.h". 223 224Example: For a TQM823L module, all configuration settings are in 225"include/configs/TQM823L.h". 226 227 228Many of the options are named exactly as the corresponding Linux 229kernel configuration options. The intention is to make it easier to 230build a config tool - later. 231 232 233The following options need to be configured: 234 235- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 236 237- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 238 239- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 240 Define exactly one, e.g. CONFIG_ATSTK1002 241 242- CPU Module Type: (if CONFIG_COGENT is defined) 243 Define exactly one of 244 CONFIG_CMA286_60_OLD 245--- FIXME --- not tested yet: 246 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 247 CONFIG_CMA287_23, CONFIG_CMA287_50 248 249- Motherboard Type: (if CONFIG_COGENT is defined) 250 Define exactly one of 251 CONFIG_CMA101, CONFIG_CMA102 252 253- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 254 Define one or more of 255 CONFIG_CMA302 256 257- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 258 Define one or more of 259 CONFIG_LCD_HEARTBEAT - update a character position on 260 the lcd display every second with 261 a "rotator" |\-/|\-/ 262 263- Board flavour: (if CONFIG_MPC8260ADS is defined) 264 CONFIG_ADSTYPE 265 Possible values are: 266 CFG_8260ADS - original MPC8260ADS 267 CFG_8266ADS - MPC8266ADS 268 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 269 CFG_8272ADS - MPC8272ADS 270 271- MPC824X Family Member (if CONFIG_MPC824X is defined) 272 Define exactly one of 273 CONFIG_MPC8240, CONFIG_MPC8245 274 275- 8xx CPU Options: (if using an MPC8xx cpu) 276 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 277 get_gclk_freq() cannot work 278 e.g. if there is no 32KHz 279 reference PIT/RTC clock 280 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 281 or XTAL/EXTAL) 282 283- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 284 CFG_8xx_CPUCLK_MIN 285 CFG_8xx_CPUCLK_MAX 286 CONFIG_8xx_CPUCLK_DEFAULT 287 See doc/README.MPC866 288 289 CFG_MEASURE_CPUCLK 290 291 Define this to measure the actual CPU clock instead 292 of relying on the correctness of the configured 293 values. Mostly useful for board bringup to make sure 294 the PLL is locked at the intended frequency. Note 295 that this requires a (stable) reference clock (32 kHz 296 RTC clock or CFG_8XX_XIN) 297 298- Intel Monahans options: 299 CFG_MONAHANS_RUN_MODE_OSC_RATIO 300 301 Defines the Monahans run mode to oscillator 302 ratio. Valid values are 8, 16, 24, 31. The core 303 frequency is this value multiplied by 13 MHz. 304 305 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 306 307 Defines the Monahans turbo mode to oscillator 308 ratio. Valid values are 1 (default if undefined) and 309 2. The core frequency as calculated above is multiplied 310 by this value. 311 312- Linux Kernel Interface: 313 CONFIG_CLOCKS_IN_MHZ 314 315 U-Boot stores all clock information in Hz 316 internally. For binary compatibility with older Linux 317 kernels (which expect the clocks passed in the 318 bd_info data to be in MHz) the environment variable 319 "clocks_in_mhz" can be defined so that U-Boot 320 converts clock data to MHZ before passing it to the 321 Linux kernel. 322 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 323 "clocks_in_mhz=1" is automatically included in the 324 default environment. 325 326 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 327 328 When transfering memsize parameter to linux, some versions 329 expect it to be in bytes, others in MB. 330 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 331 332 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 333 334 New kernel versions are expecting firmware settings to be 335 passed using flattened device trees (based on open firmware 336 concepts). 337 338 CONFIG_OF_LIBFDT 339 * New libfdt-based support 340 * Adds the "fdt" command 341 * The bootm command automatically updates the fdt 342 343 CONFIG_OF_FLAT_TREE 344 * Deprecated, see CONFIG_OF_LIBFDT 345 * Original ft_build.c-based support 346 * Automatically modifies the dft as part of the bootm command 347 * The environment variable "disable_of", when set, 348 disables this functionality. 349 350 OF_CPU - The proper name of the cpus node. 351 OF_SOC - The proper name of the soc node. 352 OF_TBCLK - The timebase frequency. 353 OF_STDOUT_PATH - The path to the console device 354 355 boards with QUICC Engines require OF_QE to set UCC mac addresses 356 357 CONFIG_OF_HAS_BD_T 358 359 * CONFIG_OF_LIBFDT - enables the "fdt bd_t" command 360 * CONFIG_OF_FLAT_TREE - The resulting flat device tree 361 will have a copy of the bd_t. Space should be 362 pre-allocated in the dts for the bd_t. 363 364 CONFIG_OF_HAS_UBOOT_ENV 365 366 * CONFIG_OF_LIBFDT - enables the "fdt env" command 367 * CONFIG_OF_FLAT_TREE - The resulting flat device tree 368 will have a copy of u-boot's environment variables 369 370 CONFIG_OF_BOARD_SETUP 371 372 Board code has addition modification that it wants to make 373 to the flat device tree before handing it off to the kernel 374 375 CONFIG_OF_BOOT_CPU 376 377 This define fills in the correct boot cpu in the boot 378 param header, the default value is zero if undefined. 379 380- Serial Ports: 381 CFG_PL010_SERIAL 382 383 Define this if you want support for Amba PrimeCell PL010 UARTs. 384 385 CFG_PL011_SERIAL 386 387 Define this if you want support for Amba PrimeCell PL011 UARTs. 388 389 CONFIG_PL011_CLOCK 390 391 If you have Amba PrimeCell PL011 UARTs, set this variable to 392 the clock speed of the UARTs. 393 394 CONFIG_PL01x_PORTS 395 396 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 397 define this to a list of base addresses for each (supported) 398 port. See e.g. include/configs/versatile.h 399 400 401- Console Interface: 402 Depending on board, define exactly one serial port 403 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 404 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 405 console by defining CONFIG_8xx_CONS_NONE 406 407 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 408 port routines must be defined elsewhere 409 (i.e. serial_init(), serial_getc(), ...) 410 411 CONFIG_CFB_CONSOLE 412 Enables console device for a color framebuffer. Needs following 413 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 414 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 415 (default big endian) 416 VIDEO_HW_RECTFILL graphic chip supports 417 rectangle fill 418 (cf. smiLynxEM) 419 VIDEO_HW_BITBLT graphic chip supports 420 bit-blit (cf. smiLynxEM) 421 VIDEO_VISIBLE_COLS visible pixel columns 422 (cols=pitch) 423 VIDEO_VISIBLE_ROWS visible pixel rows 424 VIDEO_PIXEL_SIZE bytes per pixel 425 VIDEO_DATA_FORMAT graphic data format 426 (0-5, cf. cfb_console.c) 427 VIDEO_FB_ADRS framebuffer address 428 VIDEO_KBD_INIT_FCT keyboard int fct 429 (i.e. i8042_kbd_init()) 430 VIDEO_TSTC_FCT test char fct 431 (i.e. i8042_tstc) 432 VIDEO_GETC_FCT get char fct 433 (i.e. i8042_getc) 434 CONFIG_CONSOLE_CURSOR cursor drawing on/off 435 (requires blink timer 436 cf. i8042.c) 437 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 438 CONFIG_CONSOLE_TIME display time/date info in 439 upper right corner 440 (requires CONFIG_CMD_DATE) 441 CONFIG_VIDEO_LOGO display Linux logo in 442 upper left corner 443 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 444 linux_logo.h for logo. 445 Requires CONFIG_VIDEO_LOGO 446 CONFIG_CONSOLE_EXTRA_INFO 447 addional board info beside 448 the logo 449 450 When CONFIG_CFB_CONSOLE is defined, video console is 451 default i/o. Serial console can be forced with 452 environment 'console=serial'. 453 454 When CONFIG_SILENT_CONSOLE is defined, all console 455 messages (by U-Boot and Linux!) can be silenced with 456 the "silent" environment variable. See 457 doc/README.silent for more information. 458 459- Console Baudrate: 460 CONFIG_BAUDRATE - in bps 461 Select one of the baudrates listed in 462 CFG_BAUDRATE_TABLE, see below. 463 CFG_BRGCLK_PRESCALE, baudrate prescale 464 465- Interrupt driven serial port input: 466 CONFIG_SERIAL_SOFTWARE_FIFO 467 468 PPC405GP only. 469 Use an interrupt handler for receiving data on the 470 serial port. It also enables using hardware handshake 471 (RTS/CTS) and UART's built-in FIFO. Set the number of 472 bytes the interrupt driven input buffer should have. 473 474 Leave undefined to disable this feature, including 475 disable the buffer and hardware handshake. 476 477- Console UART Number: 478 CONFIG_UART1_CONSOLE 479 480 AMCC PPC4xx only. 481 If defined internal UART1 (and not UART0) is used 482 as default U-Boot console. 483 484- Boot Delay: CONFIG_BOOTDELAY - in seconds 485 Delay before automatically booting the default image; 486 set to -1 to disable autoboot. 487 488 See doc/README.autoboot for these options that 489 work with CONFIG_BOOTDELAY. None are required. 490 CONFIG_BOOT_RETRY_TIME 491 CONFIG_BOOT_RETRY_MIN 492 CONFIG_AUTOBOOT_KEYED 493 CONFIG_AUTOBOOT_PROMPT 494 CONFIG_AUTOBOOT_DELAY_STR 495 CONFIG_AUTOBOOT_STOP_STR 496 CONFIG_AUTOBOOT_DELAY_STR2 497 CONFIG_AUTOBOOT_STOP_STR2 498 CONFIG_ZERO_BOOTDELAY_CHECK 499 CONFIG_RESET_TO_RETRY 500 501- Autoboot Command: 502 CONFIG_BOOTCOMMAND 503 Only needed when CONFIG_BOOTDELAY is enabled; 504 define a command string that is automatically executed 505 when no character is read on the console interface 506 within "Boot Delay" after reset. 507 508 CONFIG_BOOTARGS 509 This can be used to pass arguments to the bootm 510 command. The value of CONFIG_BOOTARGS goes into the 511 environment value "bootargs". 512 513 CONFIG_RAMBOOT and CONFIG_NFSBOOT 514 The value of these goes into the environment as 515 "ramboot" and "nfsboot" respectively, and can be used 516 as a convenience, when switching between booting from 517 ram and nfs. 518 519- Pre-Boot Commands: 520 CONFIG_PREBOOT 521 522 When this option is #defined, the existence of the 523 environment variable "preboot" will be checked 524 immediately before starting the CONFIG_BOOTDELAY 525 countdown and/or running the auto-boot command resp. 526 entering interactive mode. 527 528 This feature is especially useful when "preboot" is 529 automatically generated or modified. For an example 530 see the LWMON board specific code: here "preboot" is 531 modified when the user holds down a certain 532 combination of keys on the (special) keyboard when 533 booting the systems 534 535- Serial Download Echo Mode: 536 CONFIG_LOADS_ECHO 537 If defined to 1, all characters received during a 538 serial download (using the "loads" command) are 539 echoed back. This might be needed by some terminal 540 emulations (like "cu"), but may as well just take 541 time on others. This setting #define's the initial 542 value of the "loads_echo" environment variable. 543 544- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 545 CONFIG_KGDB_BAUDRATE 546 Select one of the baudrates listed in 547 CFG_BAUDRATE_TABLE, see below. 548 549- Monitor Functions: 550 Monitor commands can be included or excluded 551 from the build by using the #include files 552 "config_cmd_all.h" and #undef'ing unwanted 553 commands, or using "config_cmd_default.h" 554 and augmenting with additional #define's 555 for wanted commands. 556 557 The default command configuration includes all commands 558 except those marked below with a "*". 559 560 CONFIG_CMD_ASKENV * ask for env variable 561 CONFIG_CMD_AUTOSCRIPT Autoscript Support 562 CONFIG_CMD_BDI bdinfo 563 CONFIG_CMD_BEDBUG * Include BedBug Debugger 564 CONFIG_CMD_BMP * BMP support 565 CONFIG_CMD_BSP * Board specific commands 566 CONFIG_CMD_BOOTD bootd 567 CONFIG_CMD_CACHE * icache, dcache 568 CONFIG_CMD_CONSOLE coninfo 569 CONFIG_CMD_DATE * support for RTC, date/time... 570 CONFIG_CMD_DHCP * DHCP support 571 CONFIG_CMD_DIAG * Diagnostics 572 CONFIG_CMD_DOC * Disk-On-Chip Support 573 CONFIG_CMD_DTT * Digital Therm and Thermostat 574 CONFIG_CMD_ECHO echo arguments 575 CONFIG_CMD_EEPROM * EEPROM read/write support 576 CONFIG_CMD_ELF * bootelf, bootvx 577 CONFIG_CMD_ENV saveenv 578 CONFIG_CMD_FDC * Floppy Disk Support 579 CONFIG_CMD_FAT * FAT partition support 580 CONFIG_CMD_FDOS * Dos diskette Support 581 CONFIG_CMD_FLASH flinfo, erase, protect 582 CONFIG_CMD_FPGA FPGA device initialization support 583 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 584 CONFIG_CMD_I2C * I2C serial bus support 585 CONFIG_CMD_IDE * IDE harddisk support 586 CONFIG_CMD_IMI iminfo 587 CONFIG_CMD_IMLS List all found images 588 CONFIG_CMD_IMMAP * IMMR dump support 589 CONFIG_CMD_IRQ * irqinfo 590 CONFIG_CMD_ITEST Integer/string test of 2 values 591 CONFIG_CMD_JFFS2 * JFFS2 Support 592 CONFIG_CMD_KGDB * kgdb 593 CONFIG_CMD_LOADB loadb 594 CONFIG_CMD_LOADS loads 595 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 596 loop, loopw, mtest 597 CONFIG_CMD_MISC Misc functions like sleep etc 598 CONFIG_CMD_MMC * MMC memory mapped support 599 CONFIG_CMD_MII * MII utility commands 600 CONFIG_CMD_NAND * NAND support 601 CONFIG_CMD_NET bootp, tftpboot, rarpboot 602 CONFIG_CMD_PCI * pciinfo 603 CONFIG_CMD_PCMCIA * PCMCIA support 604 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 605 host 606 CONFIG_CMD_PORTIO * Port I/O 607 CONFIG_CMD_REGINFO * Register dump 608 CONFIG_CMD_RUN run command in env variable 609 CONFIG_CMD_SAVES * save S record dump 610 CONFIG_CMD_SCSI * SCSI Support 611 CONFIG_CMD_SDRAM * print SDRAM configuration information 612 (requires CONFIG_CMD_I2C) 613 CONFIG_CMD_SETGETDCR Support for DCR Register access 614 (4xx only) 615 CONFIG_CMD_SPI * SPI serial bus support 616 CONFIG_CMD_USB * USB support 617 CONFIG_CMD_VFD * VFD support (TRAB) 618 CONFIG_CMD_BSP * Board SPecific functions 619 CONFIG_CMD_CDP * Cisco Discover Protocol support 620 CONFIG_CMD_FSL * Microblaze FSL support 621 622 623 EXAMPLE: If you want all functions except of network 624 support you can write: 625 626 #include "config_cmd_all.h" 627 #undef CONFIG_CMD_NET 628 629 Other Commands: 630 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 631 632 Note: Don't enable the "icache" and "dcache" commands 633 (configuration option CONFIG_CMD_CACHE) unless you know 634 what you (and your U-Boot users) are doing. Data 635 cache cannot be enabled on systems like the 8xx or 636 8260 (where accesses to the IMMR region must be 637 uncached), and it cannot be disabled on all other 638 systems where we (mis-) use the data cache to hold an 639 initial stack and some data. 640 641 642 XXX - this list needs to get updated! 643 644- Watchdog: 645 CONFIG_WATCHDOG 646 If this variable is defined, it enables watchdog 647 support. There must be support in the platform specific 648 code for a watchdog. For the 8xx and 8260 CPUs, the 649 SIU Watchdog feature is enabled in the SYPCR 650 register. 651 652- U-Boot Version: 653 CONFIG_VERSION_VARIABLE 654 If this variable is defined, an environment variable 655 named "ver" is created by U-Boot showing the U-Boot 656 version as printed by the "version" command. 657 This variable is readonly. 658 659- Real-Time Clock: 660 661 When CONFIG_CMD_DATE is selected, the type of the RTC 662 has to be selected, too. Define exactly one of the 663 following options: 664 665 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 666 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 667 CONFIG_RTC_MC146818 - use MC146818 RTC 668 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 669 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 670 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 671 CONFIG_RTC_DS164x - use Dallas DS164x RTC 672 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 673 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 674 675 Note that if the RTC uses I2C, then the I2C interface 676 must also be configured. See I2C Support, below. 677 678- Timestamp Support: 679 680 When CONFIG_TIMESTAMP is selected, the timestamp 681 (date and time) of an image is printed by image 682 commands like bootm or iminfo. This option is 683 automatically enabled when you select CONFIG_CMD_DATE . 684 685- Partition Support: 686 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 687 and/or CONFIG_ISO_PARTITION 688 689 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 690 CONFIG_CMD_SCSI) you must configure support for at least 691 one partition type as well. 692 693- IDE Reset method: 694 CONFIG_IDE_RESET_ROUTINE - this is defined in several 695 board configurations files but used nowhere! 696 697 CONFIG_IDE_RESET - is this is defined, IDE Reset will 698 be performed by calling the function 699 ide_set_reset(int reset) 700 which has to be defined in a board specific file 701 702- ATAPI Support: 703 CONFIG_ATAPI 704 705 Set this to enable ATAPI support. 706 707- LBA48 Support 708 CONFIG_LBA48 709 710 Set this to enable support for disks larger than 137GB 711 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 712 Whithout these , LBA48 support uses 32bit variables and will 'only' 713 support disks up to 2.1TB. 714 715 CFG_64BIT_LBA: 716 When enabled, makes the IDE subsystem use 64bit sector addresses. 717 Default is 32bit. 718 719- SCSI Support: 720 At the moment only there is only support for the 721 SYM53C8XX SCSI controller; define 722 CONFIG_SCSI_SYM53C8XX to enable it. 723 724 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 725 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 726 CFG_SCSI_MAX_LUN] can be adjusted to define the 727 maximum numbers of LUNs, SCSI ID's and target 728 devices. 729 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 730 731- NETWORK Support (PCI): 732 CONFIG_E1000 733 Support for Intel 8254x gigabit chips. 734 735 CONFIG_EEPRO100 736 Support for Intel 82557/82559/82559ER chips. 737 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 738 write routine for first time initialisation. 739 740 CONFIG_TULIP 741 Support for Digital 2114x chips. 742 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 743 modem chip initialisation (KS8761/QS6611). 744 745 CONFIG_NATSEMI 746 Support for National dp83815 chips. 747 748 CONFIG_NS8382X 749 Support for National dp8382[01] gigabit chips. 750 751- NETWORK Support (other): 752 753 CONFIG_DRIVER_LAN91C96 754 Support for SMSC's LAN91C96 chips. 755 756 CONFIG_LAN91C96_BASE 757 Define this to hold the physical address 758 of the LAN91C96's I/O space 759 760 CONFIG_LAN91C96_USE_32_BIT 761 Define this to enable 32 bit addressing 762 763 CONFIG_DRIVER_SMC91111 764 Support for SMSC's LAN91C111 chip 765 766 CONFIG_SMC91111_BASE 767 Define this to hold the physical address 768 of the device (I/O space) 769 770 CONFIG_SMC_USE_32_BIT 771 Define this if data bus is 32 bits 772 773 CONFIG_SMC_USE_IOFUNCS 774 Define this to use i/o functions instead of macros 775 (some hardware wont work with macros) 776 777- USB Support: 778 At the moment only the UHCI host controller is 779 supported (PIP405, MIP405, MPC5200); define 780 CONFIG_USB_UHCI to enable it. 781 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 782 and define CONFIG_USB_STORAGE to enable the USB 783 storage devices. 784 Note: 785 Supported are USB Keyboards and USB Floppy drives 786 (TEAC FD-05PUB). 787 MPC5200 USB requires additional defines: 788 CONFIG_USB_CLOCK 789 for 528 MHz Clock: 0x0001bbbb 790 CONFIG_USB_CONFIG 791 for differential drivers: 0x00001000 792 for single ended drivers: 0x00005000 793 CFG_USB_EVENT_POLL 794 May be defined to allow interrupt polling 795 instead of using asynchronous interrupts 796 797- USB Device: 798 Define the below if you wish to use the USB console. 799 Once firmware is rebuilt from a serial console issue the 800 command "setenv stdin usbtty; setenv stdout usbtty" and 801 attach your usb cable. The Unix command "dmesg" should print 802 it has found a new device. The environment variable usbtty 803 can be set to gserial or cdc_acm to enable your device to 804 appear to a USB host as a Linux gserial device or a 805 Common Device Class Abstract Control Model serial device. 806 If you select usbtty = gserial you should be able to enumerate 807 a Linux host by 808 # modprobe usbserial vendor=0xVendorID product=0xProductID 809 else if using cdc_acm, simply setting the environment 810 variable usbtty to be cdc_acm should suffice. The following 811 might be defined in YourBoardName.h 812 813 CONFIG_USB_DEVICE 814 Define this to build a UDC device 815 816 CONFIG_USB_TTY 817 Define this to have a tty type of device available to 818 talk to the UDC device 819 820 CFG_CONSOLE_IS_IN_ENV 821 Define this if you want stdin, stdout &/or stderr to 822 be set to usbtty. 823 824 mpc8xx: 825 CFG_USB_EXTC_CLK 0xBLAH 826 Derive USB clock from external clock "blah" 827 - CFG_USB_EXTC_CLK 0x02 828 829 CFG_USB_BRG_CLK 0xBLAH 830 Derive USB clock from brgclk 831 - CFG_USB_BRG_CLK 0x04 832 833 If you have a USB-IF assigned VendorID then you may wish to 834 define your own vendor specific values either in BoardName.h 835 or directly in usbd_vendor_info.h. If you don't define 836 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 837 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 838 should pretend to be a Linux device to it's target host. 839 840 CONFIG_USBD_MANUFACTURER 841 Define this string as the name of your company for 842 - CONFIG_USBD_MANUFACTURER "my company" 843 844 CONFIG_USBD_PRODUCT_NAME 845 Define this string as the name of your product 846 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 847 848 CONFIG_USBD_VENDORID 849 Define this as your assigned Vendor ID from the USB 850 Implementors Forum. This *must* be a genuine Vendor ID 851 to avoid polluting the USB namespace. 852 - CONFIG_USBD_VENDORID 0xFFFF 853 854 CONFIG_USBD_PRODUCTID 855 Define this as the unique Product ID 856 for your device 857 - CONFIG_USBD_PRODUCTID 0xFFFF 858 859 860- MMC Support: 861 The MMC controller on the Intel PXA is supported. To 862 enable this define CONFIG_MMC. The MMC can be 863 accessed from the boot prompt by mapping the device 864 to physical memory similar to flash. Command line is 865 enabled with CONFIG_CMD_MMC. The MMC driver also works with 866 the FAT fs. This is enabled with CONFIG_CMD_FAT. 867 868- Journaling Flash filesystem support: 869 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 870 CONFIG_JFFS2_NAND_DEV 871 Define these for a default partition on a NAND device 872 873 CFG_JFFS2_FIRST_SECTOR, 874 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 875 Define these for a default partition on a NOR device 876 877 CFG_JFFS_CUSTOM_PART 878 Define this to create an own partition. You have to provide a 879 function struct part_info* jffs2_part_info(int part_num) 880 881 If you define only one JFFS2 partition you may also want to 882 #define CFG_JFFS_SINGLE_PART 1 883 to disable the command chpart. This is the default when you 884 have not defined a custom partition 885 886- Keyboard Support: 887 CONFIG_ISA_KEYBOARD 888 889 Define this to enable standard (PC-Style) keyboard 890 support 891 892 CONFIG_I8042_KBD 893 Standard PC keyboard driver with US (is default) and 894 GERMAN key layout (switch via environment 'keymap=de') support. 895 Export function i8042_kbd_init, i8042_tstc and i8042_getc 896 for cfb_console. Supports cursor blinking. 897 898- Video support: 899 CONFIG_VIDEO 900 901 Define this to enable video support (for output to 902 video). 903 904 CONFIG_VIDEO_CT69000 905 906 Enable Chips & Technologies 69000 Video chip 907 908 CONFIG_VIDEO_SMI_LYNXEM 909 Enable Silicon Motion SMI 712/710/810 Video chip. The 910 video output is selected via environment 'videoout' 911 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 912 assumed. 913 914 For the CT69000 and SMI_LYNXEM drivers, videomode is 915 selected via environment 'videomode'. Two diferent ways 916 are possible: 917 - "videomode=num" 'num' is a standard LiLo mode numbers. 918 Following standard modes are supported (* is default): 919 920 Colors 640x480 800x600 1024x768 1152x864 1280x1024 921 -------------+--------------------------------------------- 922 8 bits | 0x301* 0x303 0x305 0x161 0x307 923 15 bits | 0x310 0x313 0x316 0x162 0x319 924 16 bits | 0x311 0x314 0x317 0x163 0x31A 925 24 bits | 0x312 0x315 0x318 ? 0x31B 926 -------------+--------------------------------------------- 927 (i.e. setenv videomode 317; saveenv; reset;) 928 929 - "videomode=bootargs" all the video parameters are parsed 930 from the bootargs. (See drivers/video/videomodes.c) 931 932 933 CONFIG_VIDEO_SED13806 934 Enable Epson SED13806 driver. This driver supports 8bpp 935 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 936 or CONFIG_VIDEO_SED13806_16BPP 937 938- Keyboard Support: 939 CONFIG_KEYBOARD 940 941 Define this to enable a custom keyboard support. 942 This simply calls drv_keyboard_init() which must be 943 defined in your board-specific files. 944 The only board using this so far is RBC823. 945 946- LCD Support: CONFIG_LCD 947 948 Define this to enable LCD support (for output to LCD 949 display); also select one of the supported displays 950 by defining one of these: 951 952 CONFIG_NEC_NL6448AC33: 953 954 NEC NL6448AC33-18. Active, color, single scan. 955 956 CONFIG_NEC_NL6448BC20 957 958 NEC NL6448BC20-08. 6.5", 640x480. 959 Active, color, single scan. 960 961 CONFIG_NEC_NL6448BC33_54 962 963 NEC NL6448BC33-54. 10.4", 640x480. 964 Active, color, single scan. 965 966 CONFIG_SHARP_16x9 967 968 Sharp 320x240. Active, color, single scan. 969 It isn't 16x9, and I am not sure what it is. 970 971 CONFIG_SHARP_LQ64D341 972 973 Sharp LQ64D341 display, 640x480. 974 Active, color, single scan. 975 976 CONFIG_HLD1045 977 978 HLD1045 display, 640x480. 979 Active, color, single scan. 980 981 CONFIG_OPTREX_BW 982 983 Optrex CBL50840-2 NF-FW 99 22 M5 984 or 985 Hitachi LMG6912RPFC-00T 986 or 987 Hitachi SP14Q002 988 989 320x240. Black & white. 990 991 Normally display is black on white background; define 992 CFG_WHITE_ON_BLACK to get it inverted. 993 994- Splash Screen Support: CONFIG_SPLASH_SCREEN 995 996 If this option is set, the environment is checked for 997 a variable "splashimage". If found, the usual display 998 of logo, copyright and system information on the LCD 999 is suppressed and the BMP image at the address 1000 specified in "splashimage" is loaded instead. The 1001 console is redirected to the "nulldev", too. This 1002 allows for a "silent" boot where a splash screen is 1003 loaded very quickly after power-on. 1004 1005- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1006 1007 If this option is set, additionally to standard BMP 1008 images, gzipped BMP images can be displayed via the 1009 splashscreen support or the bmp command. 1010 1011- Compression support: 1012 CONFIG_BZIP2 1013 1014 If this option is set, support for bzip2 compressed 1015 images is included. If not, only uncompressed and gzip 1016 compressed images are supported. 1017 1018 NOTE: the bzip2 algorithm requires a lot of RAM, so 1019 the malloc area (as defined by CFG_MALLOC_LEN) should 1020 be at least 4MB. 1021 1022- MII/PHY support: 1023 CONFIG_PHY_ADDR 1024 1025 The address of PHY on MII bus. 1026 1027 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1028 1029 The clock frequency of the MII bus 1030 1031 CONFIG_PHY_GIGE 1032 1033 If this option is set, support for speed/duplex 1034 detection of Gigabit PHY is included. 1035 1036 CONFIG_PHY_RESET_DELAY 1037 1038 Some PHY like Intel LXT971A need extra delay after 1039 reset before any MII register access is possible. 1040 For such PHY, set this option to the usec delay 1041 required. (minimum 300usec for LXT971A) 1042 1043 CONFIG_PHY_CMD_DELAY (ppc4xx) 1044 1045 Some PHY like Intel LXT971A need extra delay after 1046 command issued before MII status register can be read 1047 1048- Ethernet address: 1049 CONFIG_ETHADDR 1050 CONFIG_ETH2ADDR 1051 CONFIG_ETH3ADDR 1052 1053 Define a default value for ethernet address to use 1054 for the respective ethernet interface, in case this 1055 is not determined automatically. 1056 1057- IP address: 1058 CONFIG_IPADDR 1059 1060 Define a default value for the IP address to use for 1061 the default ethernet interface, in case this is not 1062 determined through e.g. bootp. 1063 1064- Server IP address: 1065 CONFIG_SERVERIP 1066 1067 Defines a default value for theIP address of a TFTP 1068 server to contact when using the "tftboot" command. 1069 1070- Multicast TFTP Mode: 1071 CONFIG_MCAST_TFTP 1072 1073 Defines whether you want to support multicast TFTP as per 1074 rfc-2090; for example to work with atftp. Lets lots of targets 1075 tftp down the same boot image concurrently. Note: the ethernet 1076 driver in use must provide a function: mcast() to join/leave a 1077 multicast group. 1078 1079 CONFIG_BOOTP_RANDOM_DELAY 1080- BOOTP Recovery Mode: 1081 CONFIG_BOOTP_RANDOM_DELAY 1082 1083 If you have many targets in a network that try to 1084 boot using BOOTP, you may want to avoid that all 1085 systems send out BOOTP requests at precisely the same 1086 moment (which would happen for instance at recovery 1087 from a power failure, when all systems will try to 1088 boot, thus flooding the BOOTP server. Defining 1089 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1090 inserted before sending out BOOTP requests. The 1091 following delays are inserted then: 1092 1093 1st BOOTP request: delay 0 ... 1 sec 1094 2nd BOOTP request: delay 0 ... 2 sec 1095 3rd BOOTP request: delay 0 ... 4 sec 1096 4th and following 1097 BOOTP requests: delay 0 ... 8 sec 1098 1099- DHCP Advanced Options: 1100 You can fine tune the DHCP functionality by defining 1101 CONFIG_BOOTP_* symbols: 1102 1103 CONFIG_BOOTP_SUBNETMASK 1104 CONFIG_BOOTP_GATEWAY 1105 CONFIG_BOOTP_HOSTNAME 1106 CONFIG_BOOTP_NISDOMAIN 1107 CONFIG_BOOTP_BOOTPATH 1108 CONFIG_BOOTP_BOOTFILESIZE 1109 CONFIG_BOOTP_DNS 1110 CONFIG_BOOTP_DNS2 1111 CONFIG_BOOTP_SEND_HOSTNAME 1112 CONFIG_BOOTP_NTPSERVER 1113 CONFIG_BOOTP_TIMEOFFSET 1114 CONFIG_BOOTP_VENDOREX 1115 1116 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1117 environment variable, not the BOOTP server. 1118 1119 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1120 serverip from a DHCP server, it is possible that more 1121 than one DNS serverip is offered to the client. 1122 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1123 serverip will be stored in the additional environment 1124 variable "dnsip2". The first DNS serverip is always 1125 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1126 is defined. 1127 1128 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1129 to do a dynamic update of a DNS server. To do this, they 1130 need the hostname of the DHCP requester. 1131 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1132 of the "hostname" environment variable is passed as 1133 option 12 to the DHCP server. 1134 1135 - CDP Options: 1136 CONFIG_CDP_DEVICE_ID 1137 1138 The device id used in CDP trigger frames. 1139 1140 CONFIG_CDP_DEVICE_ID_PREFIX 1141 1142 A two character string which is prefixed to the MAC address 1143 of the device. 1144 1145 CONFIG_CDP_PORT_ID 1146 1147 A printf format string which contains the ascii name of 1148 the port. Normally is set to "eth%d" which sets 1149 eth0 for the first ethernet, eth1 for the second etc. 1150 1151 CONFIG_CDP_CAPABILITIES 1152 1153 A 32bit integer which indicates the device capabilities; 1154 0x00000010 for a normal host which does not forwards. 1155 1156 CONFIG_CDP_VERSION 1157 1158 An ascii string containing the version of the software. 1159 1160 CONFIG_CDP_PLATFORM 1161 1162 An ascii string containing the name of the platform. 1163 1164 CONFIG_CDP_TRIGGER 1165 1166 A 32bit integer sent on the trigger. 1167 1168 CONFIG_CDP_POWER_CONSUMPTION 1169 1170 A 16bit integer containing the power consumption of the 1171 device in .1 of milliwatts. 1172 1173 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1174 1175 A byte containing the id of the VLAN. 1176 1177- Status LED: CONFIG_STATUS_LED 1178 1179 Several configurations allow to display the current 1180 status using a LED. For instance, the LED will blink 1181 fast while running U-Boot code, stop blinking as 1182 soon as a reply to a BOOTP request was received, and 1183 start blinking slow once the Linux kernel is running 1184 (supported by a status LED driver in the Linux 1185 kernel). Defining CONFIG_STATUS_LED enables this 1186 feature in U-Boot. 1187 1188- CAN Support: CONFIG_CAN_DRIVER 1189 1190 Defining CONFIG_CAN_DRIVER enables CAN driver support 1191 on those systems that support this (optional) 1192 feature, like the TQM8xxL modules. 1193 1194- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1195 1196 These enable I2C serial bus commands. Defining either of 1197 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1198 include the appropriate I2C driver for the selected cpu. 1199 1200 This will allow you to use i2c commands at the u-boot 1201 command line (as long as you set CONFIG_CMD_I2C in 1202 CONFIG_COMMANDS) and communicate with i2c based realtime 1203 clock chips. See common/cmd_i2c.c for a description of the 1204 command line interface. 1205 1206 CONFIG_I2C_CMD_TREE is a recommended option that places 1207 all I2C commands under a single 'i2c' root command. The 1208 older 'imm', 'imd', 'iprobe' etc. commands are considered 1209 deprecated and may disappear in the future. 1210 1211 CONFIG_HARD_I2C selects a hardware I2C controller. 1212 1213 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1214 bit-banging) driver instead of CPM or similar hardware 1215 support for I2C. 1216 1217 There are several other quantities that must also be 1218 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1219 1220 In both cases you will need to define CFG_I2C_SPEED 1221 to be the frequency (in Hz) at which you wish your i2c bus 1222 to run and CFG_I2C_SLAVE to be the address of this node (ie 1223 the cpu's i2c node address). 1224 1225 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1226 sets the cpu up as a master node and so its address should 1227 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1228 p.16-473). So, set CFG_I2C_SLAVE to 0. 1229 1230 That's all that's required for CONFIG_HARD_I2C. 1231 1232 If you use the software i2c interface (CONFIG_SOFT_I2C) 1233 then the following macros need to be defined (examples are 1234 from include/configs/lwmon.h): 1235 1236 I2C_INIT 1237 1238 (Optional). Any commands necessary to enable the I2C 1239 controller or configure ports. 1240 1241 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1242 1243 I2C_PORT 1244 1245 (Only for MPC8260 CPU). The I/O port to use (the code 1246 assumes both bits are on the same port). Valid values 1247 are 0..3 for ports A..D. 1248 1249 I2C_ACTIVE 1250 1251 The code necessary to make the I2C data line active 1252 (driven). If the data line is open collector, this 1253 define can be null. 1254 1255 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1256 1257 I2C_TRISTATE 1258 1259 The code necessary to make the I2C data line tri-stated 1260 (inactive). If the data line is open collector, this 1261 define can be null. 1262 1263 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1264 1265 I2C_READ 1266 1267 Code that returns TRUE if the I2C data line is high, 1268 FALSE if it is low. 1269 1270 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1271 1272 I2C_SDA(bit) 1273 1274 If <bit> is TRUE, sets the I2C data line high. If it 1275 is FALSE, it clears it (low). 1276 1277 eg: #define I2C_SDA(bit) \ 1278 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1279 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1280 1281 I2C_SCL(bit) 1282 1283 If <bit> is TRUE, sets the I2C clock line high. If it 1284 is FALSE, it clears it (low). 1285 1286 eg: #define I2C_SCL(bit) \ 1287 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1288 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1289 1290 I2C_DELAY 1291 1292 This delay is invoked four times per clock cycle so this 1293 controls the rate of data transfer. The data rate thus 1294 is 1 / (I2C_DELAY * 4). Often defined to be something 1295 like: 1296 1297 #define I2C_DELAY udelay(2) 1298 1299 CFG_I2C_INIT_BOARD 1300 1301 When a board is reset during an i2c bus transfer 1302 chips might think that the current transfer is still 1303 in progress. On some boards it is possible to access 1304 the i2c SCLK line directly, either by using the 1305 processor pin as a GPIO or by having a second pin 1306 connected to the bus. If this option is defined a 1307 custom i2c_init_board() routine in boards/xxx/board.c 1308 is run early in the boot sequence. 1309 1310 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1311 1312 This option enables configuration of bi_iic_fast[] flags 1313 in u-boot bd_info structure based on u-boot environment 1314 variable "i2cfast". (see also i2cfast) 1315 1316 CONFIG_I2C_MULTI_BUS 1317 1318 This option allows the use of multiple I2C buses, each of which 1319 must have a controller. At any point in time, only one bus is 1320 active. To switch to a different bus, use the 'i2c dev' command. 1321 Note that bus numbering is zero-based. 1322 1323 CFG_I2C_NOPROBES 1324 1325 This option specifies a list of I2C devices that will be skipped 1326 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1327 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1328 pairs. Otherwise, specify a 1D array of device addresses 1329 1330 e.g. 1331 #undef CONFIG_I2C_MULTI_BUS 1332 #define CFG_I2C_NOPROBES {0x50,0x68} 1333 1334 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1335 1336 #define CONFIG_I2C_MULTI_BUS 1337 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1338 1339 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1340 1341 CFG_SPD_BUS_NUM 1342 1343 If defined, then this indicates the I2C bus number for DDR SPD. 1344 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1345 1346 CFG_RTC_BUS_NUM 1347 1348 If defined, then this indicates the I2C bus number for the RTC. 1349 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1350 1351 CFG_DTT_BUS_NUM 1352 1353 If defined, then this indicates the I2C bus number for the DTT. 1354 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1355 1356 CONFIG_FSL_I2C 1357 1358 Define this option if you want to use Freescale's I2C driver in 1359 drivers/i2c/fsl_i2c.c. 1360 1361 1362- SPI Support: CONFIG_SPI 1363 1364 Enables SPI driver (so far only tested with 1365 SPI EEPROM, also an instance works with Crystal A/D and 1366 D/As on the SACSng board) 1367 1368 CONFIG_SPI_X 1369 1370 Enables extended (16-bit) SPI EEPROM addressing. 1371 (symmetrical to CONFIG_I2C_X) 1372 1373 CONFIG_SOFT_SPI 1374 1375 Enables a software (bit-bang) SPI driver rather than 1376 using hardware support. This is a general purpose 1377 driver that only requires three general I/O port pins 1378 (two outputs, one input) to function. If this is 1379 defined, the board configuration must define several 1380 SPI configuration items (port pins to use, etc). For 1381 an example, see include/configs/sacsng.h. 1382 1383 CONFIG_HARD_SPI 1384 1385 Enables a hardware SPI driver for general-purpose reads 1386 and writes. As with CONFIG_SOFT_SPI, the board configuration 1387 must define a list of chip-select function pointers. 1388 Currently supported on some MPC8xxx processors. For an 1389 example, see include/configs/mpc8349emds.h. 1390 1391- FPGA Support: CONFIG_FPGA 1392 1393 Enables FPGA subsystem. 1394 1395 CONFIG_FPGA_<vendor> 1396 1397 Enables support for specific chip vendors. 1398 (ALTERA, XILINX) 1399 1400 CONFIG_FPGA_<family> 1401 1402 Enables support for FPGA family. 1403 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1404 1405 CONFIG_FPGA_COUNT 1406 1407 Specify the number of FPGA devices to support. 1408 1409 CFG_FPGA_PROG_FEEDBACK 1410 1411 Enable printing of hash marks during FPGA configuration. 1412 1413 CFG_FPGA_CHECK_BUSY 1414 1415 Enable checks on FPGA configuration interface busy 1416 status by the configuration function. This option 1417 will require a board or device specific function to 1418 be written. 1419 1420 CONFIG_FPGA_DELAY 1421 1422 If defined, a function that provides delays in the FPGA 1423 configuration driver. 1424 1425 CFG_FPGA_CHECK_CTRLC 1426 Allow Control-C to interrupt FPGA configuration 1427 1428 CFG_FPGA_CHECK_ERROR 1429 1430 Check for configuration errors during FPGA bitfile 1431 loading. For example, abort during Virtex II 1432 configuration if the INIT_B line goes low (which 1433 indicated a CRC error). 1434 1435 CFG_FPGA_WAIT_INIT 1436 1437 Maximum time to wait for the INIT_B line to deassert 1438 after PROB_B has been deasserted during a Virtex II 1439 FPGA configuration sequence. The default time is 500 1440 mS. 1441 1442 CFG_FPGA_WAIT_BUSY 1443 1444 Maximum time to wait for BUSY to deassert during 1445 Virtex II FPGA configuration. The default is 5 mS. 1446 1447 CFG_FPGA_WAIT_CONFIG 1448 1449 Time to wait after FPGA configuration. The default is 1450 200 mS. 1451 1452- Configuration Management: 1453 CONFIG_IDENT_STRING 1454 1455 If defined, this string will be added to the U-Boot 1456 version information (U_BOOT_VERSION) 1457 1458- Vendor Parameter Protection: 1459 1460 U-Boot considers the values of the environment 1461 variables "serial#" (Board Serial Number) and 1462 "ethaddr" (Ethernet Address) to be parameters that 1463 are set once by the board vendor / manufacturer, and 1464 protects these variables from casual modification by 1465 the user. Once set, these variables are read-only, 1466 and write or delete attempts are rejected. You can 1467 change this behviour: 1468 1469 If CONFIG_ENV_OVERWRITE is #defined in your config 1470 file, the write protection for vendor parameters is 1471 completely disabled. Anybody can change or delete 1472 these parameters. 1473 1474 Alternatively, if you #define _both_ CONFIG_ETHADDR 1475 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1476 ethernet address is installed in the environment, 1477 which can be changed exactly ONCE by the user. [The 1478 serial# is unaffected by this, i. e. it remains 1479 read-only.] 1480 1481- Protected RAM: 1482 CONFIG_PRAM 1483 1484 Define this variable to enable the reservation of 1485 "protected RAM", i. e. RAM which is not overwritten 1486 by U-Boot. Define CONFIG_PRAM to hold the number of 1487 kB you want to reserve for pRAM. You can overwrite 1488 this default value by defining an environment 1489 variable "pram" to the number of kB you want to 1490 reserve. Note that the board info structure will 1491 still show the full amount of RAM. If pRAM is 1492 reserved, a new environment variable "mem" will 1493 automatically be defined to hold the amount of 1494 remaining RAM in a form that can be passed as boot 1495 argument to Linux, for instance like that: 1496 1497 setenv bootargs ... mem=\${mem} 1498 saveenv 1499 1500 This way you can tell Linux not to use this memory, 1501 either, which results in a memory region that will 1502 not be affected by reboots. 1503 1504 *WARNING* If your board configuration uses automatic 1505 detection of the RAM size, you must make sure that 1506 this memory test is non-destructive. So far, the 1507 following board configurations are known to be 1508 "pRAM-clean": 1509 1510 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1511 HERMES, IP860, RPXlite, LWMON, LANTEC, 1512 PCU_E, FLAGADM, TQM8260 1513 1514- Error Recovery: 1515 CONFIG_PANIC_HANG 1516 1517 Define this variable to stop the system in case of a 1518 fatal error, so that you have to reset it manually. 1519 This is probably NOT a good idea for an embedded 1520 system where you want to system to reboot 1521 automatically as fast as possible, but it may be 1522 useful during development since you can try to debug 1523 the conditions that lead to the situation. 1524 1525 CONFIG_NET_RETRY_COUNT 1526 1527 This variable defines the number of retries for 1528 network operations like ARP, RARP, TFTP, or BOOTP 1529 before giving up the operation. If not defined, a 1530 default value of 5 is used. 1531 1532- Command Interpreter: 1533 CONFIG_AUTO_COMPLETE 1534 1535 Enable auto completion of commands using TAB. 1536 1537 Note that this feature has NOT been implemented yet 1538 for the "hush" shell. 1539 1540 1541 CFG_HUSH_PARSER 1542 1543 Define this variable to enable the "hush" shell (from 1544 Busybox) as command line interpreter, thus enabling 1545 powerful command line syntax like 1546 if...then...else...fi conditionals or `&&' and '||' 1547 constructs ("shell scripts"). 1548 1549 If undefined, you get the old, much simpler behaviour 1550 with a somewhat smaller memory footprint. 1551 1552 1553 CFG_PROMPT_HUSH_PS2 1554 1555 This defines the secondary prompt string, which is 1556 printed when the command interpreter needs more input 1557 to complete a command. Usually "> ". 1558 1559 Note: 1560 1561 In the current implementation, the local variables 1562 space and global environment variables space are 1563 separated. Local variables are those you define by 1564 simply typing `name=value'. To access a local 1565 variable later on, you have write `$name' or 1566 `${name}'; to execute the contents of a variable 1567 directly type `$name' at the command prompt. 1568 1569 Global environment variables are those you use 1570 setenv/printenv to work with. To run a command stored 1571 in such a variable, you need to use the run command, 1572 and you must not use the '$' sign to access them. 1573 1574 To store commands and special characters in a 1575 variable, please use double quotation marks 1576 surrounding the whole text of the variable, instead 1577 of the backslashes before semicolons and special 1578 symbols. 1579 1580- Commandline Editing and History: 1581 CONFIG_CMDLINE_EDITING 1582 1583 Enable editiong and History functions for interactive 1584 commandline input operations 1585 1586- Default Environment: 1587 CONFIG_EXTRA_ENV_SETTINGS 1588 1589 Define this to contain any number of null terminated 1590 strings (variable = value pairs) that will be part of 1591 the default environment compiled into the boot image. 1592 1593 For example, place something like this in your 1594 board's config file: 1595 1596 #define CONFIG_EXTRA_ENV_SETTINGS \ 1597 "myvar1=value1\0" \ 1598 "myvar2=value2\0" 1599 1600 Warning: This method is based on knowledge about the 1601 internal format how the environment is stored by the 1602 U-Boot code. This is NOT an official, exported 1603 interface! Although it is unlikely that this format 1604 will change soon, there is no guarantee either. 1605 You better know what you are doing here. 1606 1607 Note: overly (ab)use of the default environment is 1608 discouraged. Make sure to check other ways to preset 1609 the environment like the autoscript function or the 1610 boot command first. 1611 1612- DataFlash Support: 1613 CONFIG_HAS_DATAFLASH 1614 1615 Defining this option enables DataFlash features and 1616 allows to read/write in Dataflash via the standard 1617 commands cp, md... 1618 1619- SystemACE Support: 1620 CONFIG_SYSTEMACE 1621 1622 Adding this option adds support for Xilinx SystemACE 1623 chips attached via some sort of local bus. The address 1624 of the chip must alsh be defined in the 1625 CFG_SYSTEMACE_BASE macro. For example: 1626 1627 #define CONFIG_SYSTEMACE 1628 #define CFG_SYSTEMACE_BASE 0xf0000000 1629 1630 When SystemACE support is added, the "ace" device type 1631 becomes available to the fat commands, i.e. fatls. 1632 1633- TFTP Fixed UDP Port: 1634 CONFIG_TFTP_PORT 1635 1636 If this is defined, the environment variable tftpsrcp 1637 is used to supply the TFTP UDP source port value. 1638 If tftpsrcp isn't defined, the normal pseudo-random port 1639 number generator is used. 1640 1641 Also, the environment variable tftpdstp is used to supply 1642 the TFTP UDP destination port value. If tftpdstp isn't 1643 defined, the normal port 69 is used. 1644 1645 The purpose for tftpsrcp is to allow a TFTP server to 1646 blindly start the TFTP transfer using the pre-configured 1647 target IP address and UDP port. This has the effect of 1648 "punching through" the (Windows XP) firewall, allowing 1649 the remainder of the TFTP transfer to proceed normally. 1650 A better solution is to properly configure the firewall, 1651 but sometimes that is not allowed. 1652 1653- Show boot progress: 1654 CONFIG_SHOW_BOOT_PROGRESS 1655 1656 Defining this option allows to add some board- 1657 specific code (calling a user-provided function 1658 "show_boot_progress(int)") that enables you to show 1659 the system's boot progress on some display (for 1660 example, some LED's) on your board. At the moment, 1661 the following checkpoints are implemented: 1662 1663Legacy uImage format: 1664 1665 Arg Where When 1666 1 common/cmd_bootm.c before attempting to boot an image 1667 -1 common/cmd_bootm.c Image header has bad magic number 1668 2 common/cmd_bootm.c Image header has correct magic number 1669 -2 common/cmd_bootm.c Image header has bad checksum 1670 3 common/cmd_bootm.c Image header has correct checksum 1671 -3 common/cmd_bootm.c Image data has bad checksum 1672 4 common/cmd_bootm.c Image data has correct checksum 1673 -4 common/cmd_bootm.c Image is for unsupported architecture 1674 5 common/cmd_bootm.c Architecture check OK 1675 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1676 6 common/cmd_bootm.c Image Type check OK 1677 -6 common/cmd_bootm.c gunzip uncompression error 1678 -7 common/cmd_bootm.c Unimplemented compression type 1679 7 common/cmd_bootm.c Uncompression OK 1680 8 common/cmd_bootm.c No uncompress/copy overwrite error 1681 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1682 1683 9 common/image.c Start initial ramdisk verification 1684 -10 common/image.c Ramdisk header has bad magic number 1685 -11 common/image.c Ramdisk header has bad checksum 1686 10 common/image.c Ramdisk header is OK 1687 -12 common/image.c Ramdisk data has bad checksum 1688 11 common/image.c Ramdisk data has correct checksum 1689 12 common/image.c Ramdisk verification complete, start loading 1690 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1691 13 common/image.c Start multifile image verification 1692 14 common/image.c No initial ramdisk, no multifile, continue. 1693 1694 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1695 1696 -30 lib_ppc/board.c Fatal error, hang the system 1697 -31 post/post.c POST test failed, detected by post_output_backlog() 1698 -32 post/post.c POST test failed, detected by post_run_single() 1699 1700 34 common/cmd_doc.c before loading a Image from a DOC device 1701 -35 common/cmd_doc.c Bad usage of "doc" command 1702 35 common/cmd_doc.c correct usage of "doc" command 1703 -36 common/cmd_doc.c No boot device 1704 36 common/cmd_doc.c correct boot device 1705 -37 common/cmd_doc.c Unknown Chip ID on boot device 1706 37 common/cmd_doc.c correct chip ID found, device available 1707 -38 common/cmd_doc.c Read Error on boot device 1708 38 common/cmd_doc.c reading Image header from DOC device OK 1709 -39 common/cmd_doc.c Image header has bad magic number 1710 39 common/cmd_doc.c Image header has correct magic number 1711 -40 common/cmd_doc.c Error reading Image from DOC device 1712 40 common/cmd_doc.c Image header has correct magic number 1713 41 common/cmd_ide.c before loading a Image from a IDE device 1714 -42 common/cmd_ide.c Bad usage of "ide" command 1715 42 common/cmd_ide.c correct usage of "ide" command 1716 -43 common/cmd_ide.c No boot device 1717 43 common/cmd_ide.c boot device found 1718 -44 common/cmd_ide.c Device not available 1719 44 common/cmd_ide.c Device available 1720 -45 common/cmd_ide.c wrong partition selected 1721 45 common/cmd_ide.c partition selected 1722 -46 common/cmd_ide.c Unknown partition table 1723 46 common/cmd_ide.c valid partition table found 1724 -47 common/cmd_ide.c Invalid partition type 1725 47 common/cmd_ide.c correct partition type 1726 -48 common/cmd_ide.c Error reading Image Header on boot device 1727 48 common/cmd_ide.c reading Image Header from IDE device OK 1728 -49 common/cmd_ide.c Image header has bad magic number 1729 49 common/cmd_ide.c Image header has correct magic number 1730 -50 common/cmd_ide.c Image header has bad checksum 1731 50 common/cmd_ide.c Image header has correct checksum 1732 -51 common/cmd_ide.c Error reading Image from IDE device 1733 51 common/cmd_ide.c reading Image from IDE device OK 1734 52 common/cmd_nand.c before loading a Image from a NAND device 1735 -53 common/cmd_nand.c Bad usage of "nand" command 1736 53 common/cmd_nand.c correct usage of "nand" command 1737 -54 common/cmd_nand.c No boot device 1738 54 common/cmd_nand.c boot device found 1739 -55 common/cmd_nand.c Unknown Chip ID on boot device 1740 55 common/cmd_nand.c correct chip ID found, device available 1741 -56 common/cmd_nand.c Error reading Image Header on boot device 1742 56 common/cmd_nand.c reading Image Header from NAND device OK 1743 -57 common/cmd_nand.c Image header has bad magic number 1744 57 common/cmd_nand.c Image header has correct magic number 1745 -58 common/cmd_nand.c Error reading Image from NAND device 1746 58 common/cmd_nand.c reading Image from NAND device OK 1747 1748 -60 common/env_common.c Environment has a bad CRC, using default 1749 1750 64 net/eth.c starting with Ethernetconfiguration. 1751 -64 net/eth.c no Ethernet found. 1752 65 net/eth.c Ethernet found. 1753 1754 -80 common/cmd_net.c usage wrong 1755 80 common/cmd_net.c before calling NetLoop() 1756 -81 common/cmd_net.c some error in NetLoop() occured 1757 81 common/cmd_net.c NetLoop() back without error 1758 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1759 82 common/cmd_net.c trying automatic boot 1760 83 common/cmd_net.c running autoscript 1761 -83 common/cmd_net.c some error in automatic boot or autoscript 1762 84 common/cmd_net.c end without errors 1763 1764FIT uImage format: 1765 1766 Arg Where When 1767 100 common/cmd_bootm.c Kernel FIT Image has correct format 1768 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1769 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1770 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1771 102 common/cmd_bootm.c Kernel unit name specified 1772 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1773 103 common/cmd_bootm.c Found configuration node 1774 104 common/cmd_bootm.c Got kernel subimage node offset 1775 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1776 105 common/cmd_bootm.c Kernel subimage hash verification OK 1777 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1778 106 common/cmd_bootm.c Architecture check OK 1779 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1780 107 common/cmd_bootm.c Kernel subimge type OK 1781 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1782 108 common/cmd_bootm.c Got kernel subimage data/size 1783 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1784 -109 common/cmd_bootm.c Can't get kernel subimage type 1785 -110 common/cmd_bootm.c Can't get kernel subimage comp 1786 -111 common/cmd_bootm.c Can't get kernel subimage os 1787 -112 common/cmd_bootm.c Can't get kernel subimage load address 1788 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1789 1790 120 common/image.c Start initial ramdisk verification 1791 -120 common/image.c Ramdisk FIT image has incorrect format 1792 121 common/image.c Ramdisk FIT image has correct format 1793 122 common/image.c No Ramdisk subimage unit name, using configuration 1794 -122 common/image.c Can't get configuration for ramdisk subimage 1795 123 common/image.c Ramdisk unit name specified 1796 -124 common/image.c Can't get ramdisk subimage node offset 1797 125 common/image.c Got ramdisk subimage node offset 1798 -125 common/image.c Ramdisk subimage hash verification failed 1799 126 common/image.c Ramdisk subimage hash verification OK 1800 -126 common/image.c Ramdisk subimage for unsupported architecture 1801 127 common/image.c Architecture check OK 1802 -127 common/image.c Can't get ramdisk subimage data/size 1803 128 common/image.c Got ramdisk subimage data/size 1804 129 common/image.c Can't get ramdisk load address 1805 -129 common/image.c Got ramdisk load address 1806 1807 -130 common/cmd_doc.c Icorrect FIT image format 1808 131 common/cmd_doc.c FIT image format OK 1809 1810 -140 common/cmd_ide.c Icorrect FIT image format 1811 141 common/cmd_ide.c FIT image format OK 1812 1813 -150 common/cmd_nand.c Icorrect FIT image format 1814 151 common/cmd_nand.c FIT image format OK 1815 1816 1817Modem Support: 1818-------------- 1819 1820[so far only for SMDK2400 and TRAB boards] 1821 1822- Modem support endable: 1823 CONFIG_MODEM_SUPPORT 1824 1825- RTS/CTS Flow control enable: 1826 CONFIG_HWFLOW 1827 1828- Modem debug support: 1829 CONFIG_MODEM_SUPPORT_DEBUG 1830 1831 Enables debugging stuff (char screen[1024], dbg()) 1832 for modem support. Useful only with BDI2000. 1833 1834- Interrupt support (PPC): 1835 1836 There are common interrupt_init() and timer_interrupt() 1837 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1838 for cpu specific initialization. interrupt_init_cpu() 1839 should set decrementer_count to appropriate value. If 1840 cpu resets decrementer automatically after interrupt 1841 (ppc4xx) it should set decrementer_count to zero. 1842 timer_interrupt() calls timer_interrupt_cpu() for cpu 1843 specific handling. If board has watchdog / status_led 1844 / other_activity_monitor it works automatically from 1845 general timer_interrupt(). 1846 1847- General: 1848 1849 In the target system modem support is enabled when a 1850 specific key (key combination) is pressed during 1851 power-on. Otherwise U-Boot will boot normally 1852 (autoboot). The key_pressed() fuction is called from 1853 board_init(). Currently key_pressed() is a dummy 1854 function, returning 1 and thus enabling modem 1855 initialization. 1856 1857 If there are no modem init strings in the 1858 environment, U-Boot proceed to autoboot; the 1859 previous output (banner, info printfs) will be 1860 supressed, though. 1861 1862 See also: doc/README.Modem 1863 1864 1865Configuration Settings: 1866----------------------- 1867 1868- CFG_LONGHELP: Defined when you want long help messages included; 1869 undefine this when you're short of memory. 1870 1871- CFG_PROMPT: This is what U-Boot prints on the console to 1872 prompt for user input. 1873 1874- CFG_CBSIZE: Buffer size for input from the Console 1875 1876- CFG_PBSIZE: Buffer size for Console output 1877 1878- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1879 1880- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1881 the application (usually a Linux kernel) when it is 1882 booted 1883 1884- CFG_BAUDRATE_TABLE: 1885 List of legal baudrate settings for this board. 1886 1887- CFG_CONSOLE_INFO_QUIET 1888 Suppress display of console information at boot. 1889 1890- CFG_CONSOLE_IS_IN_ENV 1891 If the board specific function 1892 extern int overwrite_console (void); 1893 returns 1, the stdin, stderr and stdout are switched to the 1894 serial port, else the settings in the environment are used. 1895 1896- CFG_CONSOLE_OVERWRITE_ROUTINE 1897 Enable the call to overwrite_console(). 1898 1899- CFG_CONSOLE_ENV_OVERWRITE 1900 Enable overwrite of previous console environment settings. 1901 1902- CFG_MEMTEST_START, CFG_MEMTEST_END: 1903 Begin and End addresses of the area used by the 1904 simple memory test. 1905 1906- CFG_ALT_MEMTEST: 1907 Enable an alternate, more extensive memory test. 1908 1909- CFG_MEMTEST_SCRATCH: 1910 Scratch address used by the alternate memory test 1911 You only need to set this if address zero isn't writeable 1912 1913- CFG_TFTP_LOADADDR: 1914 Default load address for network file downloads 1915 1916- CFG_LOADS_BAUD_CHANGE: 1917 Enable temporary baudrate change while serial download 1918 1919- CFG_SDRAM_BASE: 1920 Physical start address of SDRAM. _Must_ be 0 here. 1921 1922- CFG_MBIO_BASE: 1923 Physical start address of Motherboard I/O (if using a 1924 Cogent motherboard) 1925 1926- CFG_FLASH_BASE: 1927 Physical start address of Flash memory. 1928 1929- CFG_MONITOR_BASE: 1930 Physical start address of boot monitor code (set by 1931 make config files to be same as the text base address 1932 (TEXT_BASE) used when linking) - same as 1933 CFG_FLASH_BASE when booting from flash. 1934 1935- CFG_MONITOR_LEN: 1936 Size of memory reserved for monitor code, used to 1937 determine _at_compile_time_ (!) if the environment is 1938 embedded within the U-Boot image, or in a separate 1939 flash sector. 1940 1941- CFG_MALLOC_LEN: 1942 Size of DRAM reserved for malloc() use. 1943 1944- CFG_BOOTM_LEN: 1945 Normally compressed uImages are limited to an 1946 uncompressed size of 8 MBytes. If this is not enough, 1947 you can define CFG_BOOTM_LEN in your board config file 1948 to adjust this setting to your needs. 1949 1950- CFG_BOOTMAPSZ: 1951 Maximum size of memory mapped by the startup code of 1952 the Linux kernel; all data that must be processed by 1953 the Linux kernel (bd_info, boot arguments, eventually 1954 initrd image) must be put below this limit. 1955 1956- CFG_MAX_FLASH_BANKS: 1957 Max number of Flash memory banks 1958 1959- CFG_MAX_FLASH_SECT: 1960 Max number of sectors on a Flash chip 1961 1962- CFG_FLASH_ERASE_TOUT: 1963 Timeout for Flash erase operations (in ms) 1964 1965- CFG_FLASH_WRITE_TOUT: 1966 Timeout for Flash write operations (in ms) 1967 1968- CFG_FLASH_LOCK_TOUT 1969 Timeout for Flash set sector lock bit operation (in ms) 1970 1971- CFG_FLASH_UNLOCK_TOUT 1972 Timeout for Flash clear lock bits operation (in ms) 1973 1974- CFG_FLASH_PROTECTION 1975 If defined, hardware flash sectors protection is used 1976 instead of U-Boot software protection. 1977 1978- CFG_DIRECT_FLASH_TFTP: 1979 1980 Enable TFTP transfers directly to flash memory; 1981 without this option such a download has to be 1982 performed in two steps: (1) download to RAM, and (2) 1983 copy from RAM to flash. 1984 1985 The two-step approach is usually more reliable, since 1986 you can check if the download worked before you erase 1987 the flash, but in some situations (when sytem RAM is 1988 too limited to allow for a tempory copy of the 1989 downloaded image) this option may be very useful. 1990 1991- CFG_FLASH_CFI: 1992 Define if the flash driver uses extra elements in the 1993 common flash structure for storing flash geometry. 1994 1995- CFG_FLASH_CFI_DRIVER 1996 This option also enables the building of the cfi_flash driver 1997 in the drivers directory 1998 1999- CFG_FLASH_QUIET_TEST 2000 If this option is defined, the common CFI flash doesn't 2001 print it's warning upon not recognized FLASH banks. This 2002 is useful, if some of the configured banks are only 2003 optionally available. 2004 2005- CONFIG_FLASH_SHOW_PROGRESS 2006 If defined (must be an integer), print out countdown 2007 digits and dots. Recommended value: 45 (9..1) for 80 2008 column displays, 15 (3..1) for 40 column displays. 2009 2010- CFG_RX_ETH_BUFFER: 2011 Defines the number of ethernet receive buffers. On some 2012 ethernet controllers it is recommended to set this value 2013 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2014 buffers can be full shortly after enabling the interface 2015 on high ethernet traffic. 2016 Defaults to 4 if not defined. 2017 2018The following definitions that deal with the placement and management 2019of environment data (variable area); in general, we support the 2020following configurations: 2021 2022- CFG_ENV_IS_IN_FLASH: 2023 2024 Define this if the environment is in flash memory. 2025 2026 a) The environment occupies one whole flash sector, which is 2027 "embedded" in the text segment with the U-Boot code. This 2028 happens usually with "bottom boot sector" or "top boot 2029 sector" type flash chips, which have several smaller 2030 sectors at the start or the end. For instance, such a 2031 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2032 such a case you would place the environment in one of the 2033 4 kB sectors - with U-Boot code before and after it. With 2034 "top boot sector" type flash chips, you would put the 2035 environment in one of the last sectors, leaving a gap 2036 between U-Boot and the environment. 2037 2038 - CFG_ENV_OFFSET: 2039 2040 Offset of environment data (variable area) to the 2041 beginning of flash memory; for instance, with bottom boot 2042 type flash chips the second sector can be used: the offset 2043 for this sector is given here. 2044 2045 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2046 2047 - CFG_ENV_ADDR: 2048 2049 This is just another way to specify the start address of 2050 the flash sector containing the environment (instead of 2051 CFG_ENV_OFFSET). 2052 2053 - CFG_ENV_SECT_SIZE: 2054 2055 Size of the sector containing the environment. 2056 2057 2058 b) Sometimes flash chips have few, equal sized, BIG sectors. 2059 In such a case you don't want to spend a whole sector for 2060 the environment. 2061 2062 - CFG_ENV_SIZE: 2063 2064 If you use this in combination with CFG_ENV_IS_IN_FLASH 2065 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2066 of this flash sector for the environment. This saves 2067 memory for the RAM copy of the environment. 2068 2069 It may also save flash memory if you decide to use this 2070 when your environment is "embedded" within U-Boot code, 2071 since then the remainder of the flash sector could be used 2072 for U-Boot code. It should be pointed out that this is 2073 STRONGLY DISCOURAGED from a robustness point of view: 2074 updating the environment in flash makes it always 2075 necessary to erase the WHOLE sector. If something goes 2076 wrong before the contents has been restored from a copy in 2077 RAM, your target system will be dead. 2078 2079 - CFG_ENV_ADDR_REDUND 2080 CFG_ENV_SIZE_REDUND 2081 2082 These settings describe a second storage area used to hold 2083 a redundand copy of the environment data, so that there is 2084 a valid backup copy in case there is a power failure during 2085 a "saveenv" operation. 2086 2087BE CAREFUL! Any changes to the flash layout, and some changes to the 2088source code will make it necessary to adapt <board>/u-boot.lds* 2089accordingly! 2090 2091 2092- CFG_ENV_IS_IN_NVRAM: 2093 2094 Define this if you have some non-volatile memory device 2095 (NVRAM, battery buffered SRAM) which you want to use for the 2096 environment. 2097 2098 - CFG_ENV_ADDR: 2099 - CFG_ENV_SIZE: 2100 2101 These two #defines are used to determin the memory area you 2102 want to use for environment. It is assumed that this memory 2103 can just be read and written to, without any special 2104 provision. 2105 2106BE CAREFUL! The first access to the environment happens quite early 2107in U-Boot initalization (when we try to get the setting of for the 2108console baudrate). You *MUST* have mappend your NVRAM area then, or 2109U-Boot will hang. 2110 2111Please note that even with NVRAM we still use a copy of the 2112environment in RAM: we could work on NVRAM directly, but we want to 2113keep settings there always unmodified except somebody uses "saveenv" 2114to save the current settings. 2115 2116 2117- CFG_ENV_IS_IN_EEPROM: 2118 2119 Use this if you have an EEPROM or similar serial access 2120 device and a driver for it. 2121 2122 - CFG_ENV_OFFSET: 2123 - CFG_ENV_SIZE: 2124 2125 These two #defines specify the offset and size of the 2126 environment area within the total memory of your EEPROM. 2127 2128 - CFG_I2C_EEPROM_ADDR: 2129 If defined, specified the chip address of the EEPROM device. 2130 The default address is zero. 2131 2132 - CFG_EEPROM_PAGE_WRITE_BITS: 2133 If defined, the number of bits used to address bytes in a 2134 single page in the EEPROM device. A 64 byte page, for example 2135 would require six bits. 2136 2137 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2138 If defined, the number of milliseconds to delay between 2139 page writes. The default is zero milliseconds. 2140 2141 - CFG_I2C_EEPROM_ADDR_LEN: 2142 The length in bytes of the EEPROM memory array address. Note 2143 that this is NOT the chip address length! 2144 2145 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2146 EEPROM chips that implement "address overflow" are ones 2147 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2148 address and the extra bits end up in the "chip address" bit 2149 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2150 byte chips. 2151 2152 Note that we consider the length of the address field to 2153 still be one byte because the extra address bits are hidden 2154 in the chip address. 2155 2156 - CFG_EEPROM_SIZE: 2157 The size in bytes of the EEPROM device. 2158 2159 2160- CFG_ENV_IS_IN_DATAFLASH: 2161 2162 Define this if you have a DataFlash memory device which you 2163 want to use for the environment. 2164 2165 - CFG_ENV_OFFSET: 2166 - CFG_ENV_ADDR: 2167 - CFG_ENV_SIZE: 2168 2169 These three #defines specify the offset and size of the 2170 environment area within the total memory of your DataFlash placed 2171 at the specified address. 2172 2173- CFG_ENV_IS_IN_NAND: 2174 2175 Define this if you have a NAND device which you want to use 2176 for the environment. 2177 2178 - CFG_ENV_OFFSET: 2179 - CFG_ENV_SIZE: 2180 2181 These two #defines specify the offset and size of the environment 2182 area within the first NAND device. 2183 2184 - CFG_ENV_OFFSET_REDUND 2185 2186 This setting describes a second storage area of CFG_ENV_SIZE 2187 size used to hold a redundant copy of the environment data, 2188 so that there is a valid backup copy in case there is a 2189 power failure during a "saveenv" operation. 2190 2191 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2192 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2193 the NAND devices block size. 2194 2195- CFG_SPI_INIT_OFFSET 2196 2197 Defines offset to the initial SPI buffer area in DPRAM. The 2198 area is used at an early stage (ROM part) if the environment 2199 is configured to reside in the SPI EEPROM: We need a 520 byte 2200 scratch DPRAM area. It is used between the two initialization 2201 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2202 to be a good choice since it makes it far enough from the 2203 start of the data area as well as from the stack pointer. 2204 2205Please note that the environment is read-only until the monitor 2206has been relocated to RAM and a RAM copy of the environment has been 2207created; also, when using EEPROM you will have to use getenv_r() 2208until then to read environment variables. 2209 2210The environment is protected by a CRC32 checksum. Before the monitor 2211is relocated into RAM, as a result of a bad CRC you will be working 2212with the compiled-in default environment - *silently*!!! [This is 2213necessary, because the first environment variable we need is the 2214"baudrate" setting for the console - if we have a bad CRC, we don't 2215have any device yet where we could complain.] 2216 2217Note: once the monitor has been relocated, then it will complain if 2218the default environment is used; a new CRC is computed as soon as you 2219use the "saveenv" command to store a valid environment. 2220 2221- CFG_FAULT_ECHO_LINK_DOWN: 2222 Echo the inverted Ethernet link state to the fault LED. 2223 2224 Note: If this option is active, then CFG_FAULT_MII_ADDR 2225 also needs to be defined. 2226 2227- CFG_FAULT_MII_ADDR: 2228 MII address of the PHY to check for the Ethernet link state. 2229 2230- CFG_64BIT_VSPRINTF: 2231 Makes vsprintf (and all *printf functions) support printing 2232 of 64bit values by using the L quantifier 2233 2234- CFG_64BIT_STRTOUL: 2235 Adds simple_strtoull that returns a 64bit value 2236 2237Low Level (hardware related) configuration options: 2238--------------------------------------------------- 2239 2240- CFG_CACHELINE_SIZE: 2241 Cache Line Size of the CPU. 2242 2243- CFG_DEFAULT_IMMR: 2244 Default address of the IMMR after system reset. 2245 2246 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2247 and RPXsuper) to be able to adjust the position of 2248 the IMMR register after a reset. 2249 2250- Floppy Disk Support: 2251 CFG_FDC_DRIVE_NUMBER 2252 2253 the default drive number (default value 0) 2254 2255 CFG_ISA_IO_STRIDE 2256 2257 defines the spacing between fdc chipset registers 2258 (default value 1) 2259 2260 CFG_ISA_IO_OFFSET 2261 2262 defines the offset of register from address. It 2263 depends on which part of the data bus is connected to 2264 the fdc chipset. (default value 0) 2265 2266 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2267 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2268 default value. 2269 2270 if CFG_FDC_HW_INIT is defined, then the function 2271 fdc_hw_init() is called at the beginning of the FDC 2272 setup. fdc_hw_init() must be provided by the board 2273 source code. It is used to make hardware dependant 2274 initializations. 2275 2276- CFG_IMMR: Physical address of the Internal Memory. 2277 DO NOT CHANGE unless you know exactly what you're 2278 doing! (11-4) [MPC8xx/82xx systems only] 2279 2280- CFG_INIT_RAM_ADDR: 2281 2282 Start address of memory area that can be used for 2283 initial data and stack; please note that this must be 2284 writable memory that is working WITHOUT special 2285 initialization, i. e. you CANNOT use normal RAM which 2286 will become available only after programming the 2287 memory controller and running certain initialization 2288 sequences. 2289 2290 U-Boot uses the following memory types: 2291 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2292 - MPC824X: data cache 2293 - PPC4xx: data cache 2294 2295- CFG_GBL_DATA_OFFSET: 2296 2297 Offset of the initial data structure in the memory 2298 area defined by CFG_INIT_RAM_ADDR. Usually 2299 CFG_GBL_DATA_OFFSET is chosen such that the initial 2300 data is located at the end of the available space 2301 (sometimes written as (CFG_INIT_RAM_END - 2302 CFG_INIT_DATA_SIZE), and the initial stack is just 2303 below that area (growing from (CFG_INIT_RAM_ADDR + 2304 CFG_GBL_DATA_OFFSET) downward. 2305 2306 Note: 2307 On the MPC824X (or other systems that use the data 2308 cache for initial memory) the address chosen for 2309 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2310 point to an otherwise UNUSED address space between 2311 the top of RAM and the start of the PCI space. 2312 2313- CFG_SIUMCR: SIU Module Configuration (11-6) 2314 2315- CFG_SYPCR: System Protection Control (11-9) 2316 2317- CFG_TBSCR: Time Base Status and Control (11-26) 2318 2319- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2320 2321- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2322 2323- CFG_SCCR: System Clock and reset Control Register (15-27) 2324 2325- CFG_OR_TIMING_SDRAM: 2326 SDRAM timing 2327 2328- CFG_MAMR_PTA: 2329 periodic timer for refresh 2330 2331- CFG_DER: Debug Event Register (37-47) 2332 2333- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2334 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2335 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2336 CFG_BR1_PRELIM: 2337 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2338 2339- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2340 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2341 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2342 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2343 2344- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2345 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2346 Machine Mode Register and Memory Periodic Timer 2347 Prescaler definitions (SDRAM timing) 2348 2349- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2350 enable I2C microcode relocation patch (MPC8xx); 2351 define relocation offset in DPRAM [DSP2] 2352 2353- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2354 enable SMC microcode relocation patch (MPC8xx); 2355 define relocation offset in DPRAM [SMC1] 2356 2357- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2358 enable SPI microcode relocation patch (MPC8xx); 2359 define relocation offset in DPRAM [SCC4] 2360 2361- CFG_USE_OSCCLK: 2362 Use OSCM clock mode on MBX8xx board. Be careful, 2363 wrong setting might damage your board. Read 2364 doc/README.MBX before setting this variable! 2365 2366- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2367 Offset of the bootmode word in DPRAM used by post 2368 (Power On Self Tests). This definition overrides 2369 #define'd default value in commproc.h resp. 2370 cpm_8260.h. 2371 2372- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2373 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2374 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2375 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2376 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2377 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2378 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2379 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2380 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2381 2382- CONFIG_SPD_EEPROM 2383 Get DDR timing information from an I2C EEPROM. Common with pluggable 2384 memory modules such as SODIMMs 2385 SPD_EEPROM_ADDRESS 2386 I2C address of the SPD EEPROM 2387 2388- CFG_SPD_BUS_NUM 2389 If SPD EEPROM is on an I2C bus other than the first one, specify here. 2390 Note that the value must resolve to something your driver can deal with. 2391 2392- CFG_83XX_DDR_USES_CS0 2393 Only for 83xx systems. If specified, then DDR should be configured 2394 using CS0 and CS1 instead of CS2 and CS3. 2395 2396- CFG_83XX_DDR_USES_CS0 2397 Only for 83xx systems. If specified, then DDR should be configured 2398 using CS0 and CS1 instead of CS2 and CS3. 2399 2400- CONFIG_ETHER_ON_FEC[12] 2401 Define to enable FEC[12] on a 8xx series processor. 2402 2403- CONFIG_FEC[12]_PHY 2404 Define to the hardcoded PHY address which corresponds 2405 to the given FEC; i. e. 2406 #define CONFIG_FEC1_PHY 4 2407 means that the PHY with address 4 is connected to FEC1 2408 2409 When set to -1, means to probe for first available. 2410 2411- CONFIG_FEC[12]_PHY_NORXERR 2412 The PHY does not have a RXERR line (RMII only). 2413 (so program the FEC to ignore it). 2414 2415- CONFIG_RMII 2416 Enable RMII mode for all FECs. 2417 Note that this is a global option, we can't 2418 have one FEC in standard MII mode and another in RMII mode. 2419 2420- CONFIG_CRC32_VERIFY 2421 Add a verify option to the crc32 command. 2422 The syntax is: 2423 2424 => crc32 -v <address> <count> <crc32> 2425 2426 Where address/count indicate a memory area 2427 and crc32 is the correct crc32 which the 2428 area should have. 2429 2430- CONFIG_LOOPW 2431 Add the "loopw" memory command. This only takes effect if 2432 the memory commands are activated globally (CONFIG_CMD_MEM). 2433 2434- CONFIG_MX_CYCLIC 2435 Add the "mdc" and "mwc" memory commands. These are cyclic 2436 "md/mw" commands. 2437 Examples: 2438 2439 => mdc.b 10 4 500 2440 This command will print 4 bytes (10,11,12,13) each 500 ms. 2441 2442 => mwc.l 100 12345678 10 2443 This command will write 12345678 to address 100 all 10 ms. 2444 2445 This only takes effect if the memory commands are activated 2446 globally (CONFIG_CMD_MEM). 2447 2448- CONFIG_SKIP_LOWLEVEL_INIT 2449- CONFIG_SKIP_RELOCATE_UBOOT 2450 2451 [ARM only] If these variables are defined, then 2452 certain low level initializations (like setting up 2453 the memory controller) are omitted and/or U-Boot does 2454 not relocate itself into RAM. 2455 Normally these variables MUST NOT be defined. The 2456 only exception is when U-Boot is loaded (to RAM) by 2457 some other boot loader or by a debugger which 2458 performs these intializations itself. 2459 2460 2461Building the Software: 2462====================== 2463 2464Building U-Boot has been tested in native PPC environments (on a 2465PowerBook G3 running LinuxPPC 2000) and in cross environments 2466(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and 2467NetBSD 1.5 on x86). 2468 2469If you are not using a native PPC environment, it is assumed that you 2470have the GNU cross compiling tools available in your path and named 2471with a prefix of "powerpc-linux-". If this is not the case, (e.g. if 2472you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change 2473the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU, 2474change it to: 2475 2476 CROSS_COMPILE = ppc_4xx- 2477 2478 2479U-Boot is intended to be simple to build. After installing the 2480sources you must configure U-Boot for one specific board type. This 2481is done by typing: 2482 2483 make NAME_config 2484 2485where "NAME_config" is the name of one of the existing 2486configurations; see the main Makefile for supported names. 2487 2488Note: for some board special configuration names may exist; check if 2489 additional information is available from the board vendor; for 2490 instance, the TQM823L systems are available without (standard) 2491 or with LCD support. You can select such additional "features" 2492 when chosing the configuration, i. e. 2493 2494 make TQM823L_config 2495 - will configure for a plain TQM823L, i. e. no LCD support 2496 2497 make TQM823L_LCD_config 2498 - will configure for a TQM823L with U-Boot console on LCD 2499 2500 etc. 2501 2502 2503Finally, type "make all", and you should get some working U-Boot 2504images ready for download to / installation on your system: 2505 2506- "u-boot.bin" is a raw binary image 2507- "u-boot" is an image in ELF binary format 2508- "u-boot.srec" is in Motorola S-Record format 2509 2510By default the build is performed locally and the objects are saved 2511in the source directory. One of the two methods can be used to change 2512this behavior and build U-Boot to some external directory: 2513 25141. Add O= to the make command line invocations: 2515 2516 make O=/tmp/build distclean 2517 make O=/tmp/build NAME_config 2518 make O=/tmp/build all 2519 25202. Set environment variable BUILD_DIR to point to the desired location: 2521 2522 export BUILD_DIR=/tmp/build 2523 make distclean 2524 make NAME_config 2525 make all 2526 2527Note that the command line "O=" setting overrides the BUILD_DIR environment 2528variable. 2529 2530 2531Please be aware that the Makefiles assume you are using GNU make, so 2532for instance on NetBSD you might need to use "gmake" instead of 2533native "make". 2534 2535 2536If the system board that you have is not listed, then you will need 2537to port U-Boot to your hardware platform. To do this, follow these 2538steps: 2539 25401. Add a new configuration option for your board to the toplevel 2541 "Makefile" and to the "MAKEALL" script, using the existing 2542 entries as examples. Note that here and at many other places 2543 boards and other names are listed in alphabetical sort order. Please 2544 keep this order. 25452. Create a new directory to hold your board specific code. Add any 2546 files you need. In your board directory, you will need at least 2547 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25483. Create a new configuration file "include/configs/<board>.h" for 2549 your board 25503. If you're porting U-Boot to a new CPU, then also create a new 2551 directory to hold your CPU specific code. Add any files you need. 25524. Run "make <board>_config" with your new name. 25535. Type "make", and you should get a working "u-boot.srec" file 2554 to be installed on your target system. 25556. Debug and solve any problems that might arise. 2556 [Of course, this last step is much harder than it sounds.] 2557 2558 2559Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2560============================================================== 2561 2562If you have modified U-Boot sources (for instance added a new board 2563or support for new devices, a new CPU, etc.) you are expected to 2564provide feedback to the other developers. The feedback normally takes 2565the form of a "patch", i. e. a context diff against a certain (latest 2566official or latest in CVS) version of U-Boot sources. 2567 2568But before you submit such a patch, please verify that your modifi- 2569cation did not break existing code. At least make sure that *ALL* of 2570the supported boards compile WITHOUT ANY compiler warnings. To do so, 2571just run the "MAKEALL" script, which will configure and build U-Boot 2572for ALL supported system. Be warned, this will take a while. You can 2573select which (cross) compiler to use by passing a `CROSS_COMPILE' 2574environment variable to the script, i. e. to use the cross tools from 2575MontaVista's Hard Hat Linux you can type 2576 2577 CROSS_COMPILE=ppc_8xx- MAKEALL 2578 2579or to build on a native PowerPC system you can type 2580 2581 CROSS_COMPILE=' ' MAKEALL 2582 2583When using the MAKEALL script, the default behaviour is to build U-Boot 2584in the source directory. This location can be changed by setting the 2585BUILD_DIR environment variable. Also, for each target built, the MAKEALL 2586script saves two log files (<target>.ERR and <target>.MAKEALL) in the 2587<source dir>/LOG directory. This default location can be changed by 2588setting the MAKEALL_LOGDIR environment variable. For example: 2589 2590 export BUILD_DIR=/tmp/build 2591 export MAKEALL_LOGDIR=/tmp/log 2592 CROSS_COMPILE=ppc_8xx- MAKEALL 2593 2594With the above settings build objects are saved in the /tmp/build, log 2595files are saved in the /tmp/log and the source tree remains clean during 2596the whole build process. 2597 2598 2599See also "U-Boot Porting Guide" below. 2600 2601 2602Monitor Commands - Overview: 2603============================ 2604 2605go - start application at address 'addr' 2606run - run commands in an environment variable 2607bootm - boot application image from memory 2608bootp - boot image via network using BootP/TFTP protocol 2609tftpboot- boot image via network using TFTP protocol 2610 and env variables "ipaddr" and "serverip" 2611 (and eventually "gatewayip") 2612rarpboot- boot image via network using RARP/TFTP protocol 2613diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2614loads - load S-Record file over serial line 2615loadb - load binary file over serial line (kermit mode) 2616md - memory display 2617mm - memory modify (auto-incrementing) 2618nm - memory modify (constant address) 2619mw - memory write (fill) 2620cp - memory copy 2621cmp - memory compare 2622crc32 - checksum calculation 2623imd - i2c memory display 2624imm - i2c memory modify (auto-incrementing) 2625inm - i2c memory modify (constant address) 2626imw - i2c memory write (fill) 2627icrc32 - i2c checksum calculation 2628iprobe - probe to discover valid I2C chip addresses 2629iloop - infinite loop on address range 2630isdram - print SDRAM configuration information 2631sspi - SPI utility commands 2632base - print or set address offset 2633printenv- print environment variables 2634setenv - set environment variables 2635saveenv - save environment variables to persistent storage 2636protect - enable or disable FLASH write protection 2637erase - erase FLASH memory 2638flinfo - print FLASH memory information 2639bdinfo - print Board Info structure 2640iminfo - print header information for application image 2641coninfo - print console devices and informations 2642ide - IDE sub-system 2643loop - infinite loop on address range 2644loopw - infinite write loop on address range 2645mtest - simple RAM test 2646icache - enable or disable instruction cache 2647dcache - enable or disable data cache 2648reset - Perform RESET of the CPU 2649echo - echo args to console 2650version - print monitor version 2651help - print online help 2652? - alias for 'help' 2653 2654 2655Monitor Commands - Detailed Description: 2656======================================== 2657 2658TODO. 2659 2660For now: just type "help <command>". 2661 2662 2663Environment Variables: 2664====================== 2665 2666U-Boot supports user configuration using Environment Variables which 2667can be made persistent by saving to Flash memory. 2668 2669Environment Variables are set using "setenv", printed using 2670"printenv", and saved to Flash using "saveenv". Using "setenv" 2671without a value can be used to delete a variable from the 2672environment. As long as you don't save the environment you are 2673working with an in-memory copy. In case the Flash area containing the 2674environment is erased by accident, a default environment is provided. 2675 2676Some configuration options can be set using Environment Variables: 2677 2678 baudrate - see CONFIG_BAUDRATE 2679 2680 bootdelay - see CONFIG_BOOTDELAY 2681 2682 bootcmd - see CONFIG_BOOTCOMMAND 2683 2684 bootargs - Boot arguments when booting an RTOS image 2685 2686 bootfile - Name of the image to load with TFTP 2687 2688 autoload - if set to "no" (any string beginning with 'n'), 2689 "bootp" will just load perform a lookup of the 2690 configuration from the BOOTP server, but not try to 2691 load any image using TFTP 2692 2693 autoscript - if set to "yes" commands like "loadb", "loady", 2694 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2695 to automatically run script images (by internally 2696 calling "autoscript"). 2697 2698 autoscript_uname - if script image is in a format (FIT) this 2699 variable is used to get script subimage unit name. 2700 2701 autostart - if set to "yes", an image loaded using the "bootp", 2702 "rarpboot", "tftpboot" or "diskboot" commands will 2703 be automatically started (by internally calling 2704 "bootm") 2705 2706 If set to "no", a standalone image passed to the 2707 "bootm" command will be copied to the load address 2708 (and eventually uncompressed), but NOT be started. 2709 This can be used to load and uncompress arbitrary 2710 data. 2711 2712 i2cfast - (PPC405GP|PPC405EP only) 2713 if set to 'y' configures Linux I2C driver for fast 2714 mode (400kHZ). This environment variable is used in 2715 initialization code. So, for changes to be effective 2716 it must be saved and board must be reset. 2717 2718 initrd_high - restrict positioning of initrd images: 2719 If this variable is not set, initrd images will be 2720 copied to the highest possible address in RAM; this 2721 is usually what you want since it allows for 2722 maximum initrd size. If for some reason you want to 2723 make sure that the initrd image is loaded below the 2724 CFG_BOOTMAPSZ limit, you can set this environment 2725 variable to a value of "no" or "off" or "0". 2726 Alternatively, you can set it to a maximum upper 2727 address to use (U-Boot will still check that it 2728 does not overwrite the U-Boot stack and data). 2729 2730 For instance, when you have a system with 16 MB 2731 RAM, and want to reserve 4 MB from use by Linux, 2732 you can do this by adding "mem=12M" to the value of 2733 the "bootargs" variable. However, now you must make 2734 sure that the initrd image is placed in the first 2735 12 MB as well - this can be done with 2736 2737 setenv initrd_high 00c00000 2738 2739 If you set initrd_high to 0xFFFFFFFF, this is an 2740 indication to U-Boot that all addresses are legal 2741 for the Linux kernel, including addresses in flash 2742 memory. In this case U-Boot will NOT COPY the 2743 ramdisk at all. This may be useful to reduce the 2744 boot time on your system, but requires that this 2745 feature is supported by your Linux kernel. 2746 2747 ipaddr - IP address; needed for tftpboot command 2748 2749 loadaddr - Default load address for commands like "bootp", 2750 "rarpboot", "tftpboot", "loadb" or "diskboot" 2751 2752 loads_echo - see CONFIG_LOADS_ECHO 2753 2754 serverip - TFTP server IP address; needed for tftpboot command 2755 2756 bootretry - see CONFIG_BOOT_RETRY_TIME 2757 2758 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2759 2760 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2761 2762 ethprime - When CONFIG_NET_MULTI is enabled controls which 2763 interface is used first. 2764 2765 ethact - When CONFIG_NET_MULTI is enabled controls which 2766 interface is currently active. For example you 2767 can do the following 2768 2769 => setenv ethact FEC ETHERNET 2770 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2771 => setenv ethact SCC ETHERNET 2772 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2773 2774 ethrotate - When set to "no" U-Boot does not go through all 2775 available network interfaces. 2776 It just stays at the currently selected interface. 2777 2778 netretry - When set to "no" each network operation will 2779 either succeed or fail without retrying. 2780 When set to "once" the network operation will 2781 fail when all the available network interfaces 2782 are tried once without success. 2783 Useful on scripts which control the retry operation 2784 themselves. 2785 2786 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2787 if set load address for the npe microcode 2788 2789 tftpsrcport - If this is set, the value is used for TFTP's 2790 UDP source port. 2791 2792 tftpdstport - If this is set, the value is used for TFTP's UDP 2793 destination port instead of the Well Know Port 69. 2794 2795 vlan - When set to a value < 4095 the traffic over 2796 ethernet is encapsulated/received over 802.1q 2797 VLAN tagged frames. 2798 2799The following environment variables may be used and automatically 2800updated by the network boot commands ("bootp" and "rarpboot"), 2801depending the information provided by your boot server: 2802 2803 bootfile - see above 2804 dnsip - IP address of your Domain Name Server 2805 dnsip2 - IP address of your secondary Domain Name Server 2806 gatewayip - IP address of the Gateway (Router) to use 2807 hostname - Target hostname 2808 ipaddr - see above 2809 netmask - Subnet Mask 2810 rootpath - Pathname of the root filesystem on the NFS server 2811 serverip - see above 2812 2813 2814There are two special Environment Variables: 2815 2816 serial# - contains hardware identification information such 2817 as type string and/or serial number 2818 ethaddr - Ethernet address 2819 2820These variables can be set only once (usually during manufacturing of 2821the board). U-Boot refuses to delete or overwrite these variables 2822once they have been set once. 2823 2824 2825Further special Environment Variables: 2826 2827 ver - Contains the U-Boot version string as printed 2828 with the "version" command. This variable is 2829 readonly (see CONFIG_VERSION_VARIABLE). 2830 2831 2832Please note that changes to some configuration parameters may take 2833only effect after the next boot (yes, that's just like Windoze :-). 2834 2835 2836Command Line Parsing: 2837===================== 2838 2839There are two different command line parsers available with U-Boot: 2840the old "simple" one, and the much more powerful "hush" shell: 2841 2842Old, simple command line parser: 2843-------------------------------- 2844 2845- supports environment variables (through setenv / saveenv commands) 2846- several commands on one line, separated by ';' 2847- variable substitution using "... ${name} ..." syntax 2848- special characters ('$', ';') can be escaped by prefixing with '\', 2849 for example: 2850 setenv bootcmd bootm \${address} 2851- You can also escape text by enclosing in single apostrophes, for example: 2852 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2853 2854Hush shell: 2855----------- 2856 2857- similar to Bourne shell, with control structures like 2858 if...then...else...fi, for...do...done; while...do...done, 2859 until...do...done, ... 2860- supports environment ("global") variables (through setenv / saveenv 2861 commands) and local shell variables (through standard shell syntax 2862 "name=value"); only environment variables can be used with "run" 2863 command 2864 2865General rules: 2866-------------- 2867 2868(1) If a command line (or an environment variable executed by a "run" 2869 command) contains several commands separated by semicolon, and 2870 one of these commands fails, then the remaining commands will be 2871 executed anyway. 2872 2873(2) If you execute several variables with one call to run (i. e. 2874 calling run with a list af variables as arguments), any failing 2875 command will cause "run" to terminate, i. e. the remaining 2876 variables are not executed. 2877 2878Note for Redundant Ethernet Interfaces: 2879======================================= 2880 2881Some boards come with redundant ethernet interfaces; U-Boot supports 2882such configurations and is capable of automatic selection of a 2883"working" interface when needed. MAC assignment works as follows: 2884 2885Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2886MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2887"eth1addr" (=>eth1), "eth2addr", ... 2888 2889If the network interface stores some valid MAC address (for instance 2890in SROM), this is used as default address if there is NO correspon- 2891ding setting in the environment; if the corresponding environment 2892variable is set, this overrides the settings in the card; that means: 2893 2894o If the SROM has a valid MAC address, and there is no address in the 2895 environment, the SROM's address is used. 2896 2897o If there is no valid address in the SROM, and a definition in the 2898 environment exists, then the value from the environment variable is 2899 used. 2900 2901o If both the SROM and the environment contain a MAC address, and 2902 both addresses are the same, this MAC address is used. 2903 2904o If both the SROM and the environment contain a MAC address, and the 2905 addresses differ, the value from the environment is used and a 2906 warning is printed. 2907 2908o If neither SROM nor the environment contain a MAC address, an error 2909 is raised. 2910 2911 2912Image Formats: 2913============== 2914 2915U-Boot is capable of booting (and performing other auxiliary operations on) 2916images in two formats: 2917 2918New uImage format (FIT) 2919----------------------- 2920 2921Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2922to Flattened Device Tree). It allows the use of images with multiple 2923components (several kernels, ramdisks, etc.), with contents protected by 2924SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2925 2926 2927Old uImage format 2928----------------- 2929 2930Old image format is based on binary files which can be basically anything, 2931preceded by a special header; see the definitions in include/image.h for 2932details; basically, the header defines the following image properties: 2933 2934* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2935 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2936 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2937 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2938* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2939 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2940 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2941* Compression Type (uncompressed, gzip, bzip2) 2942* Load Address 2943* Entry Point 2944* Image Name 2945* Image Timestamp 2946 2947The header is marked by a special Magic Number, and both the header 2948and the data portions of the image are secured against corruption by 2949CRC32 checksums. 2950 2951 2952Linux Support: 2953============== 2954 2955Although U-Boot should support any OS or standalone application 2956easily, the main focus has always been on Linux during the design of 2957U-Boot. 2958 2959U-Boot includes many features that so far have been part of some 2960special "boot loader" code within the Linux kernel. Also, any 2961"initrd" images to be used are no longer part of one big Linux image; 2962instead, kernel and "initrd" are separate images. This implementation 2963serves several purposes: 2964 2965- the same features can be used for other OS or standalone 2966 applications (for instance: using compressed images to reduce the 2967 Flash memory footprint) 2968 2969- it becomes much easier to port new Linux kernel versions because 2970 lots of low-level, hardware dependent stuff are done by U-Boot 2971 2972- the same Linux kernel image can now be used with different "initrd" 2973 images; of course this also means that different kernel images can 2974 be run with the same "initrd". This makes testing easier (you don't 2975 have to build a new "zImage.initrd" Linux image when you just 2976 change a file in your "initrd"). Also, a field-upgrade of the 2977 software is easier now. 2978 2979 2980Linux HOWTO: 2981============ 2982 2983Porting Linux to U-Boot based systems: 2984--------------------------------------- 2985 2986U-Boot cannot save you from doing all the necessary modifications to 2987configure the Linux device drivers for use with your target hardware 2988(no, we don't intend to provide a full virtual machine interface to 2989Linux :-). 2990 2991But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 2992 2993Just make sure your machine specific header file (for instance 2994include/asm-ppc/tqm8xx.h) includes the same definition of the Board 2995Information structure as we define in include/u-boot.h, and make 2996sure that your definition of IMAP_ADDR uses the same value as your 2997U-Boot configuration in CFG_IMMR. 2998 2999 3000Configuring the Linux kernel: 3001----------------------------- 3002 3003No specific requirements for U-Boot. Make sure you have some root 3004device (initial ramdisk, NFS) for your target system. 3005 3006 3007Building a Linux Image: 3008----------------------- 3009 3010With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3011not used. If you use recent kernel source, a new build target 3012"uImage" will exist which automatically builds an image usable by 3013U-Boot. Most older kernels also have support for a "pImage" target, 3014which was introduced for our predecessor project PPCBoot and uses a 3015100% compatible format. 3016 3017Example: 3018 3019 make TQM850L_config 3020 make oldconfig 3021 make dep 3022 make uImage 3023 3024The "uImage" build target uses a special tool (in 'tools/mkimage') to 3025encapsulate a compressed Linux kernel image with header information, 3026CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3027 3028* build a standard "vmlinux" kernel image (in ELF binary format): 3029 3030* convert the kernel into a raw binary image: 3031 3032 ${CROSS_COMPILE}-objcopy -O binary \ 3033 -R .note -R .comment \ 3034 -S vmlinux linux.bin 3035 3036* compress the binary image: 3037 3038 gzip -9 linux.bin 3039 3040* package compressed binary image for U-Boot: 3041 3042 mkimage -A ppc -O linux -T kernel -C gzip \ 3043 -a 0 -e 0 -n "Linux Kernel Image" \ 3044 -d linux.bin.gz uImage 3045 3046 3047The "mkimage" tool can also be used to create ramdisk images for use 3048with U-Boot, either separated from the Linux kernel image, or 3049combined into one file. "mkimage" encapsulates the images with a 64 3050byte header containing information about target architecture, 3051operating system, image type, compression method, entry points, time 3052stamp, CRC32 checksums, etc. 3053 3054"mkimage" can be called in two ways: to verify existing images and 3055print the header information, or to build new images. 3056 3057In the first form (with "-l" option) mkimage lists the information 3058contained in the header of an existing U-Boot image; this includes 3059checksum verification: 3060 3061 tools/mkimage -l image 3062 -l ==> list image header information 3063 3064The second form (with "-d" option) is used to build a U-Boot image 3065from a "data file" which is used as image payload: 3066 3067 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3068 -n name -d data_file image 3069 -A ==> set architecture to 'arch' 3070 -O ==> set operating system to 'os' 3071 -T ==> set image type to 'type' 3072 -C ==> set compression type 'comp' 3073 -a ==> set load address to 'addr' (hex) 3074 -e ==> set entry point to 'ep' (hex) 3075 -n ==> set image name to 'name' 3076 -d ==> use image data from 'datafile' 3077 3078Right now, all Linux kernels for PowerPC systems use the same load 3079address (0x00000000), but the entry point address depends on the 3080kernel version: 3081 3082- 2.2.x kernels have the entry point at 0x0000000C, 3083- 2.3.x and later kernels have the entry point at 0x00000000. 3084 3085So a typical call to build a U-Boot image would read: 3086 3087 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3088 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3089 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3090 > examples/uImage.TQM850L 3091 Image Name: 2.4.4 kernel for TQM850L 3092 Created: Wed Jul 19 02:34:59 2000 3093 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3094 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3095 Load Address: 0x00000000 3096 Entry Point: 0x00000000 3097 3098To verify the contents of the image (or check for corruption): 3099 3100 -> tools/mkimage -l 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 3108NOTE: for embedded systems where boot time is critical you can trade 3109speed for memory and install an UNCOMPRESSED image instead: this 3110needs more space in Flash, but boots much faster since it does not 3111need to be uncompressed: 3112 3113 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3114 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3115 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3116 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3117 > examples/uImage.TQM850L-uncompressed 3118 Image Name: 2.4.4 kernel for TQM850L 3119 Created: Wed Jul 19 02:34:59 2000 3120 Image Type: PowerPC Linux Kernel Image (uncompressed) 3121 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3122 Load Address: 0x00000000 3123 Entry Point: 0x00000000 3124 3125 3126Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3127when your kernel is intended to use an initial ramdisk: 3128 3129 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3130 > -A ppc -O linux -T ramdisk -C gzip \ 3131 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3132 Image Name: Simple Ramdisk Image 3133 Created: Wed Jan 12 14:01:50 2000 3134 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3135 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3136 Load Address: 0x00000000 3137 Entry Point: 0x00000000 3138 3139 3140Installing a Linux Image: 3141------------------------- 3142 3143To downloading a U-Boot image over the serial (console) interface, 3144you must convert the image to S-Record format: 3145 3146 objcopy -I binary -O srec examples/image examples/image.srec 3147 3148The 'objcopy' does not understand the information in the U-Boot 3149image header, so the resulting S-Record file will be relative to 3150address 0x00000000. To load it to a given address, you need to 3151specify the target address as 'offset' parameter with the 'loads' 3152command. 3153 3154Example: install the image to address 0x40100000 (which on the 3155TQM8xxL is in the first Flash bank): 3156 3157 => erase 40100000 401FFFFF 3158 3159 .......... done 3160 Erased 8 sectors 3161 3162 => loads 40100000 3163 ## Ready for S-Record download ... 3164 ~>examples/image.srec 3165 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3166 ... 3167 15989 15990 15991 15992 3168 [file transfer complete] 3169 [connected] 3170 ## Start Addr = 0x00000000 3171 3172 3173You can check the success of the download using the 'iminfo' command; 3174this includes a checksum verification so you can be sure no data 3175corruption happened: 3176 3177 => imi 40100000 3178 3179 ## Checking Image at 40100000 ... 3180 Image Name: 2.2.13 for initrd on TQM850L 3181 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3182 Data Size: 335725 Bytes = 327 kB = 0 MB 3183 Load Address: 00000000 3184 Entry Point: 0000000c 3185 Verifying Checksum ... OK 3186 3187 3188Boot Linux: 3189----------- 3190 3191The "bootm" command is used to boot an application that is stored in 3192memory (RAM or Flash). In case of a Linux kernel image, the contents 3193of the "bootargs" environment variable is passed to the kernel as 3194parameters. You can check and modify this variable using the 3195"printenv" and "setenv" commands: 3196 3197 3198 => printenv bootargs 3199 bootargs=root=/dev/ram 3200 3201 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3202 3203 => printenv bootargs 3204 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3205 3206 => bootm 40020000 3207 ## Booting Linux kernel at 40020000 ... 3208 Image Name: 2.2.13 for NFS on TQM850L 3209 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3210 Data Size: 381681 Bytes = 372 kB = 0 MB 3211 Load Address: 00000000 3212 Entry Point: 0000000c 3213 Verifying Checksum ... OK 3214 Uncompressing Kernel Image ... OK 3215 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 3216 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3217 time_init: decrementer frequency = 187500000/60 3218 Calibrating delay loop... 49.77 BogoMIPS 3219 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3220 ... 3221 3222If you want to boot a Linux kernel with initial ram disk, you pass 3223the memory addresses of both the kernel and the initrd image (PPBCOOT 3224format!) to the "bootm" command: 3225 3226 => imi 40100000 40200000 3227 3228 ## Checking Image at 40100000 ... 3229 Image Name: 2.2.13 for initrd on TQM850L 3230 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3231 Data Size: 335725 Bytes = 327 kB = 0 MB 3232 Load Address: 00000000 3233 Entry Point: 0000000c 3234 Verifying Checksum ... OK 3235 3236 ## Checking Image at 40200000 ... 3237 Image Name: Simple Ramdisk Image 3238 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3239 Data Size: 566530 Bytes = 553 kB = 0 MB 3240 Load Address: 00000000 3241 Entry Point: 00000000 3242 Verifying Checksum ... OK 3243 3244 => bootm 40100000 40200000 3245 ## Booting Linux kernel at 40100000 ... 3246 Image Name: 2.2.13 for initrd on TQM850L 3247 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3248 Data Size: 335725 Bytes = 327 kB = 0 MB 3249 Load Address: 00000000 3250 Entry Point: 0000000c 3251 Verifying Checksum ... OK 3252 Uncompressing Kernel Image ... OK 3253 ## Loading RAMDisk Image at 40200000 ... 3254 Image Name: Simple Ramdisk Image 3255 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3256 Data Size: 566530 Bytes = 553 kB = 0 MB 3257 Load Address: 00000000 3258 Entry Point: 00000000 3259 Verifying Checksum ... OK 3260 Loading Ramdisk ... OK 3261 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 3262 Boot arguments: root=/dev/ram 3263 time_init: decrementer frequency = 187500000/60 3264 Calibrating delay loop... 49.77 BogoMIPS 3265 ... 3266 RAMDISK: Compressed image found at block 0 3267 VFS: Mounted root (ext2 filesystem). 3268 3269 bash# 3270 3271Boot Linux and pass a flat device tree: 3272----------- 3273 3274First, U-Boot must be compiled with the appropriate defines. See the section 3275titled "Linux Kernel Interface" above for a more in depth explanation. The 3276following is an example of how to start a kernel and pass an updated 3277flat device tree: 3278 3279=> print oftaddr 3280oftaddr=0x300000 3281=> print oft 3282oft=oftrees/mpc8540ads.dtb 3283=> tftp $oftaddr $oft 3284Speed: 1000, full duplex 3285Using TSEC0 device 3286TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3287Filename 'oftrees/mpc8540ads.dtb'. 3288Load address: 0x300000 3289Loading: # 3290done 3291Bytes transferred = 4106 (100a hex) 3292=> tftp $loadaddr $bootfile 3293Speed: 1000, full duplex 3294Using TSEC0 device 3295TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3296Filename 'uImage'. 3297Load address: 0x200000 3298Loading:############ 3299done 3300Bytes transferred = 1029407 (fb51f hex) 3301=> print loadaddr 3302loadaddr=200000 3303=> print oftaddr 3304oftaddr=0x300000 3305=> bootm $loadaddr - $oftaddr 3306## Booting image at 00200000 ... 3307 Image Name: Linux-2.6.17-dirty 3308 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3309 Data Size: 1029343 Bytes = 1005.2 kB 3310 Load Address: 00000000 3311 Entry Point: 00000000 3312 Verifying Checksum ... OK 3313 Uncompressing Kernel Image ... OK 3314Booting using flat device tree at 0x300000 3315Using MPC85xx ADS machine description 3316Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3317[snip] 3318 3319 3320More About U-Boot Image Types: 3321------------------------------ 3322 3323U-Boot supports the following image types: 3324 3325 "Standalone Programs" are directly runnable in the environment 3326 provided by U-Boot; it is expected that (if they behave 3327 well) you can continue to work in U-Boot after return from 3328 the Standalone Program. 3329 "OS Kernel Images" are usually images of some Embedded OS which 3330 will take over control completely. Usually these programs 3331 will install their own set of exception handlers, device 3332 drivers, set up the MMU, etc. - this means, that you cannot 3333 expect to re-enter U-Boot except by resetting the CPU. 3334 "RAMDisk Images" are more or less just data blocks, and their 3335 parameters (address, size) are passed to an OS kernel that is 3336 being started. 3337 "Multi-File Images" contain several images, typically an OS 3338 (Linux) kernel image and one or more data images like 3339 RAMDisks. This construct is useful for instance when you want 3340 to boot over the network using BOOTP etc., where the boot 3341 server provides just a single image file, but you want to get 3342 for instance an OS kernel and a RAMDisk image. 3343 3344 "Multi-File Images" start with a list of image sizes, each 3345 image size (in bytes) specified by an "uint32_t" in network 3346 byte order. This list is terminated by an "(uint32_t)0". 3347 Immediately after the terminating 0 follow the images, one by 3348 one, all aligned on "uint32_t" boundaries (size rounded up to 3349 a multiple of 4 bytes). 3350 3351 "Firmware Images" are binary images containing firmware (like 3352 U-Boot or FPGA images) which usually will be programmed to 3353 flash memory. 3354 3355 "Script files" are command sequences that will be executed by 3356 U-Boot's command interpreter; this feature is especially 3357 useful when you configure U-Boot to use a real shell (hush) 3358 as command interpreter. 3359 3360 3361Standalone HOWTO: 3362================= 3363 3364One of the features of U-Boot is that you can dynamically load and 3365run "standalone" applications, which can use some resources of 3366U-Boot like console I/O functions or interrupt services. 3367 3368Two simple examples are included with the sources: 3369 3370"Hello World" Demo: 3371------------------- 3372 3373'examples/hello_world.c' contains a small "Hello World" Demo 3374application; it is automatically compiled when you build U-Boot. 3375It's configured to run at address 0x00040004, so you can play with it 3376like that: 3377 3378 => loads 3379 ## Ready for S-Record download ... 3380 ~>examples/hello_world.srec 3381 1 2 3 4 5 6 7 8 9 10 11 ... 3382 [file transfer complete] 3383 [connected] 3384 ## Start Addr = 0x00040004 3385 3386 => go 40004 Hello World! This is a test. 3387 ## Starting application at 0x00040004 ... 3388 Hello World 3389 argc = 7 3390 argv[0] = "40004" 3391 argv[1] = "Hello" 3392 argv[2] = "World!" 3393 argv[3] = "This" 3394 argv[4] = "is" 3395 argv[5] = "a" 3396 argv[6] = "test." 3397 argv[7] = "<NULL>" 3398 Hit any key to exit ... 3399 3400 ## Application terminated, rc = 0x0 3401 3402Another example, which demonstrates how to register a CPM interrupt 3403handler with the U-Boot code, can be found in 'examples/timer.c'. 3404Here, a CPM timer is set up to generate an interrupt every second. 3405The interrupt service routine is trivial, just printing a '.' 3406character, but this is just a demo program. The application can be 3407controlled by the following keys: 3408 3409 ? - print current values og the CPM Timer registers 3410 b - enable interrupts and start timer 3411 e - stop timer and disable interrupts 3412 q - quit application 3413 3414 => loads 3415 ## Ready for S-Record download ... 3416 ~>examples/timer.srec 3417 1 2 3 4 5 6 7 8 9 10 11 ... 3418 [file transfer complete] 3419 [connected] 3420 ## Start Addr = 0x00040004 3421 3422 => go 40004 3423 ## Starting application at 0x00040004 ... 3424 TIMERS=0xfff00980 3425 Using timer 1 3426 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3427 3428Hit 'b': 3429 [q, b, e, ?] Set interval 1000000 us 3430 Enabling timer 3431Hit '?': 3432 [q, b, e, ?] ........ 3433 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3434Hit '?': 3435 [q, b, e, ?] . 3436 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3437Hit '?': 3438 [q, b, e, ?] . 3439 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3440Hit '?': 3441 [q, b, e, ?] . 3442 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3443Hit 'e': 3444 [q, b, e, ?] ...Stopping timer 3445Hit 'q': 3446 [q, b, e, ?] ## Application terminated, rc = 0x0 3447 3448 3449Minicom warning: 3450================ 3451 3452Over time, many people have reported problems when trying to use the 3453"minicom" terminal emulation program for serial download. I (wd) 3454consider minicom to be broken, and recommend not to use it. Under 3455Unix, I recommend to use C-Kermit for general purpose use (and 3456especially for kermit binary protocol download ("loadb" command), and 3457use "cu" for S-Record download ("loads" command). 3458 3459Nevertheless, if you absolutely want to use it try adding this 3460configuration to your "File transfer protocols" section: 3461 3462 Name Program Name U/D FullScr IO-Red. Multi 3463 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3464 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3465 3466 3467NetBSD Notes: 3468============= 3469 3470Starting at version 0.9.2, U-Boot supports NetBSD both as host 3471(build U-Boot) and target system (boots NetBSD/mpc8xx). 3472 3473Building requires a cross environment; it is known to work on 3474NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3475need gmake since the Makefiles are not compatible with BSD make). 3476Note that the cross-powerpc package does not install include files; 3477attempting to build U-Boot will fail because <machine/ansi.h> is 3478missing. This file has to be installed and patched manually: 3479 3480 # cd /usr/pkg/cross/powerpc-netbsd/include 3481 # mkdir powerpc 3482 # ln -s powerpc machine 3483 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3484 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3485 3486Native builds *don't* work due to incompatibilities between native 3487and U-Boot include files. 3488 3489Booting assumes that (the first part of) the image booted is a 3490stage-2 loader which in turn loads and then invokes the kernel 3491proper. Loader sources will eventually appear in the NetBSD source 3492tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3493meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3494 3495 3496Implementation Internals: 3497========================= 3498 3499The following is not intended to be a complete description of every 3500implementation detail. However, it should help to understand the 3501inner workings of U-Boot and make it easier to port it to custom 3502hardware. 3503 3504 3505Initial Stack, Global Data: 3506--------------------------- 3507 3508The implementation of U-Boot is complicated by the fact that U-Boot 3509starts running out of ROM (flash memory), usually without access to 3510system RAM (because the memory controller is not initialized yet). 3511This means that we don't have writable Data or BSS segments, and BSS 3512is not initialized as zero. To be able to get a C environment working 3513at all, we have to allocate at least a minimal stack. Implementation 3514options for this are defined and restricted by the CPU used: Some CPU 3515models provide on-chip memory (like the IMMR area on MPC8xx and 3516MPC826x processors), on others (parts of) the data cache can be 3517locked as (mis-) used as memory, etc. 3518 3519 Chris Hallinan posted a good summary of these issues to the 3520 u-boot-users mailing list: 3521 3522 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3523 From: "Chris Hallinan" <clh@net1plus.com> 3524 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3525 ... 3526 3527 Correct me if I'm wrong, folks, but the way I understand it 3528 is this: Using DCACHE as initial RAM for Stack, etc, does not 3529 require any physical RAM backing up the cache. The cleverness 3530 is that the cache is being used as a temporary supply of 3531 necessary storage before the SDRAM controller is setup. It's 3532 beyond the scope of this list to expain the details, but you 3533 can see how this works by studying the cache architecture and 3534 operation in the architecture and processor-specific manuals. 3535 3536 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3537 is another option for the system designer to use as an 3538 initial stack/ram area prior to SDRAM being available. Either 3539 option should work for you. Using CS 4 should be fine if your 3540 board designers haven't used it for something that would 3541 cause you grief during the initial boot! It is frequently not 3542 used. 3543 3544 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3545 with your processor/board/system design. The default value 3546 you will find in any recent u-boot distribution in 3547 walnut.h should work for you. I'd set it to a value larger 3548 than your SDRAM module. If you have a 64MB SDRAM module, set 3549 it above 400_0000. Just make sure your board has no resources 3550 that are supposed to respond to that address! That code in 3551 start.S has been around a while and should work as is when 3552 you get the config right. 3553 3554 -Chris Hallinan 3555 DS4.COM, Inc. 3556 3557It is essential to remember this, since it has some impact on the C 3558code for the initialization procedures: 3559 3560* Initialized global data (data segment) is read-only. Do not attempt 3561 to write it. 3562 3563* Do not use any unitialized global data (or implicitely initialized 3564 as zero data - BSS segment) at all - this is undefined, initiali- 3565 zation is performed later (when relocating to RAM). 3566 3567* Stack space is very limited. Avoid big data buffers or things like 3568 that. 3569 3570Having only the stack as writable memory limits means we cannot use 3571normal global data to share information beween the code. But it 3572turned out that the implementation of U-Boot can be greatly 3573simplified by making a global data structure (gd_t) available to all 3574functions. We could pass a pointer to this data as argument to _all_ 3575functions, but this would bloat the code. Instead we use a feature of 3576the GCC compiler (Global Register Variables) to share the data: we 3577place a pointer (gd) to the global data into a register which we 3578reserve for this purpose. 3579 3580When choosing a register for such a purpose we are restricted by the 3581relevant (E)ABI specifications for the current architecture, and by 3582GCC's implementation. 3583 3584For PowerPC, the following registers have specific use: 3585 R1: stack pointer 3586 R2: reserved for system use 3587 R3-R4: parameter passing and return values 3588 R5-R10: parameter passing 3589 R13: small data area pointer 3590 R30: GOT pointer 3591 R31: frame pointer 3592 3593 (U-Boot also uses R14 as internal GOT pointer.) 3594 3595 ==> U-Boot will use R2 to hold a pointer to the global data 3596 3597 Note: on PPC, we could use a static initializer (since the 3598 address of the global data structure is known at compile time), 3599 but it turned out that reserving a register results in somewhat 3600 smaller code - although the code savings are not that big (on 3601 average for all boards 752 bytes for the whole U-Boot image, 3602 624 text + 127 data). 3603 3604On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3605 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3606 3607 ==> U-Boot will use P5 to hold a pointer to the global data 3608 3609On ARM, the following registers are used: 3610 3611 R0: function argument word/integer result 3612 R1-R3: function argument word 3613 R9: GOT pointer 3614 R10: stack limit (used only if stack checking if enabled) 3615 R11: argument (frame) pointer 3616 R12: temporary workspace 3617 R13: stack pointer 3618 R14: link register 3619 R15: program counter 3620 3621 ==> U-Boot will use R8 to hold a pointer to the global data 3622 3623NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3624or current versions of GCC may "optimize" the code too much. 3625 3626Memory Management: 3627------------------ 3628 3629U-Boot runs in system state and uses physical addresses, i.e. the 3630MMU is not used either for address mapping nor for memory protection. 3631 3632The available memory is mapped to fixed addresses using the memory 3633controller. In this process, a contiguous block is formed for each 3634memory type (Flash, SDRAM, SRAM), even when it consists of several 3635physical memory banks. 3636 3637U-Boot is installed in the first 128 kB of the first Flash bank (on 3638TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3639booting and sizing and initializing DRAM, the code relocates itself 3640to the upper end of DRAM. Immediately below the U-Boot code some 3641memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3642configuration setting]. Below that, a structure with global Board 3643Info data is placed, followed by the stack (growing downward). 3644 3645Additionally, some exception handler code is copied to the low 8 kB 3646of DRAM (0x00000000 ... 0x00001FFF). 3647 3648So a typical memory configuration with 16 MB of DRAM could look like 3649this: 3650 3651 0x0000 0000 Exception Vector code 3652 : 3653 0x0000 1FFF 3654 0x0000 2000 Free for Application Use 3655 : 3656 : 3657 3658 : 3659 : 3660 0x00FB FF20 Monitor Stack (Growing downward) 3661 0x00FB FFAC Board Info Data and permanent copy of global data 3662 0x00FC 0000 Malloc Arena 3663 : 3664 0x00FD FFFF 3665 0x00FE 0000 RAM Copy of Monitor Code 3666 ... eventually: LCD or video framebuffer 3667 ... eventually: pRAM (Protected RAM - unchanged by reset) 3668 0x00FF FFFF [End of RAM] 3669 3670 3671System Initialization: 3672---------------------- 3673 3674In the reset configuration, U-Boot starts at the reset entry point 3675(on most PowerPC systens at address 0x00000100). Because of the reset 3676configuration for CS0# this is a mirror of the onboard Flash memory. 3677To be able to re-map memory U-Boot then jumps to its link address. 3678To be able to implement the initialization code in C, a (small!) 3679initial stack is set up in the internal Dual Ported RAM (in case CPUs 3680which provide such a feature like MPC8xx or MPC8260), or in a locked 3681part of the data cache. After that, U-Boot initializes the CPU core, 3682the caches and the SIU. 3683 3684Next, all (potentially) available memory banks are mapped using a 3685preliminary mapping. For example, we put them on 512 MB boundaries 3686(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3687on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3688programmed for SDRAM access. Using the temporary configuration, a 3689simple memory test is run that determines the size of the SDRAM 3690banks. 3691 3692When there is more than one SDRAM bank, and the banks are of 3693different size, the largest is mapped first. For equal size, the first 3694bank (CS2#) is mapped first. The first mapping is always for address 36950x00000000, with any additional banks following immediately to create 3696contiguous memory starting from 0. 3697 3698Then, the monitor installs itself at the upper end of the SDRAM area 3699and allocates memory for use by malloc() and for the global Board 3700Info data; also, the exception vector code is copied to the low RAM 3701pages, and the final stack is set up. 3702 3703Only after this relocation will you have a "normal" C environment; 3704until that you are restricted in several ways, mostly because you are 3705running from ROM, and because the code will have to be relocated to a 3706new address in RAM. 3707 3708 3709U-Boot Porting Guide: 3710---------------------- 3711 3712[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3713list, October 2002] 3714 3715 3716int main (int argc, char *argv[]) 3717{ 3718 sighandler_t no_more_time; 3719 3720 signal (SIGALRM, no_more_time); 3721 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3722 3723 if (available_money > available_manpower) { 3724 pay consultant to port U-Boot; 3725 return 0; 3726 } 3727 3728 Download latest U-Boot source; 3729 3730 Subscribe to u-boot-users mailing list; 3731 3732 if (clueless) { 3733 email ("Hi, I am new to U-Boot, how do I get started?"); 3734 } 3735 3736 while (learning) { 3737 Read the README file in the top level directory; 3738 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3739 Read the source, Luke; 3740 } 3741 3742 if (available_money > toLocalCurrency ($2500)) { 3743 Buy a BDI2000; 3744 } else { 3745 Add a lot of aggravation and time; 3746 } 3747 3748 Create your own board support subdirectory; 3749 3750 Create your own board config file; 3751 3752 while (!running) { 3753 do { 3754 Add / modify source code; 3755 } until (compiles); 3756 Debug; 3757 if (clueless) 3758 email ("Hi, I am having problems..."); 3759 } 3760 Send patch file to Wolfgang; 3761 3762 return 0; 3763} 3764 3765void no_more_time (int sig) 3766{ 3767 hire_a_guru(); 3768} 3769 3770 3771Coding Standards: 3772----------------- 3773 3774All contributions to U-Boot should conform to the Linux kernel 3775coding style; see the file "Documentation/CodingStyle" and the script 3776"scripts/Lindent" in your Linux kernel source directory. In sources 3777originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3778spaces before parameters to function calls) is actually used. 3779 3780Source files originating from a different project (for example the 3781MTD subsystem) are generally exempt from these guidelines and are not 3782reformated to ease subsequent migration to newer versions of those 3783sources. 3784 3785Please note that U-Boot is implemented in C (and to some small parts in 3786Assembler); no C++ is used, so please do not use C++ style comments (//) 3787in your code. 3788 3789Please also stick to the following formatting rules: 3790- remove any trailing white space 3791- use TAB characters for indentation, not spaces 3792- make sure NOT to use DOS '\r\n' line feeds 3793- do not add more than 2 empty lines to source files 3794- do not add trailing empty lines to source files 3795 3796Submissions which do not conform to the standards may be returned 3797with a request to reformat the changes. 3798 3799 3800Submitting Patches: 3801------------------- 3802 3803Since the number of patches for U-Boot is growing, we need to 3804establish some rules. Submissions which do not conform to these rules 3805may be rejected, even when they contain important and valuable stuff. 3806 3807Patches shall be sent to the u-boot-users mailing list. 3808 3809When you send a patch, please include the following information with 3810it: 3811 3812* For bug fixes: a description of the bug and how your patch fixes 3813 this bug. Please try to include a way of demonstrating that the 3814 patch actually fixes something. 3815 3816* For new features: a description of the feature and your 3817 implementation. 3818 3819* A CHANGELOG entry as plaintext (separate from the patch) 3820 3821* For major contributions, your entry to the CREDITS file 3822 3823* When you add support for a new board, don't forget to add this 3824 board to the MAKEALL script, too. 3825 3826* If your patch adds new configuration options, don't forget to 3827 document these in the README file. 3828 3829* The patch itself. If you are accessing the CVS repository use "cvs 3830 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your 3831 version of diff does not support these options, then get the latest 3832 version of GNU diff. 3833 3834 The current directory when running this command shall be the top 3835 level directory of the U-Boot source tree, or it's parent directory 3836 (i. e. please make sure that your patch includes sufficient 3837 directory information for the affected files). 3838 3839 We accept patches as plain text, MIME attachments or as uuencoded 3840 gzipped text. 3841 3842* If one logical set of modifications affects or creates several 3843 files, all these changes shall be submitted in a SINGLE patch file. 3844 3845* Changesets that contain different, unrelated modifications shall be 3846 submitted as SEPARATE patches, one patch per changeset. 3847 3848 3849Notes: 3850 3851* Before sending the patch, run the MAKEALL script on your patched 3852 source tree and make sure that no errors or warnings are reported 3853 for any of the boards. 3854 3855* Keep your modifications to the necessary minimum: A patch 3856 containing several unrelated changes or arbitrary reformats will be 3857 returned with a request to re-formatting / split it. 3858 3859* If you modify existing code, make sure that your new code does not 3860 add to the memory footprint of the code ;-) Small is beautiful! 3861 When adding new features, these should compile conditionally only 3862 (using #ifdef), and the resulting code with the new feature 3863 disabled must not need more memory than the old code without your 3864 modification. 3865 3866* Remember that there is a size limit of 40 kB per message on the 3867 u-boot-users mailing list. Compression may help. 3868