1# 2# (C) Copyright 2000 - 2008 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# See file CREDITS for list of people who contributed to this 6# project. 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public License as 10# published by the Free Software Foundation; either version 2 of 11# the License, or (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program; if not, write to the Free Software 20# Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21# MA 02111-1307 USA 22# 23 24Summary: 25======== 26 27This directory contains the source code for U-Boot, a boot loader for 28Embedded boards based on PowerPC, ARM, MIPS and several other 29processors, which can be installed in a boot ROM and used to 30initialize and test the hardware or to download and run application 31code. 32 33The development of U-Boot is closely related to Linux: some parts of 34the source code originate in the Linux source tree, we have some 35header files in common, and special provision has been made to 36support booting of Linux images. 37 38Some attention has been paid to make this software easily 39configurable and extendable. For instance, all monitor commands are 40implemented with the same call interface, so that it's very easy to 41add new commands. Also, instead of permanently adding rarely used 42code (for instance hardware test utilities) to the monitor, you can 43load and run it dynamically. 44 45 46Status: 47======= 48 49In general, all boards for which a configuration option exists in the 50Makefile have been tested to some extent and can be considered 51"working". In fact, many of them are used in production systems. 52 53In case of problems see the CHANGELOG and CREDITS files to find out 54who contributed the specific port. The MAINTAINERS file lists board 55maintainers. 56 57 58Where to get help: 59================== 60 61In case you have questions about, problems with or contributions for 62U-Boot you should send a message to the U-Boot mailing list at 63<u-boot-users@lists.sourceforge.net>. There is also an archive of 64previous traffic on the mailing list - please search the archive 65before asking FAQ's. Please see 66http://lists.sourceforge.net/lists/listinfo/u-boot-users/ 67 68 69Where to get source code: 70========================= 71 72The U-Boot source code is maintained in the git repository at 73git://www.denx.de/git/u-boot.git ; you can browse it online at 74http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 75 76The "snapshot" links on this page allow you to download tarballs of 77any version you might be interested in. Ofifcial releases are also 78available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 79directory. 80 81Pre-built (and tested) images are available from 82ftp://ftp.denx.de/pub/u-boot/images/ 83 84 85Where we come from: 86=================== 87 88- start from 8xxrom sources 89- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 90- clean up code 91- make it easier to add custom boards 92- make it possible to add other [PowerPC] CPUs 93- extend functions, especially: 94 * Provide extended interface to Linux boot loader 95 * S-Record download 96 * network boot 97 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot 98- create ARMBoot project (http://sourceforge.net/projects/armboot) 99- add other CPU families (starting with ARM) 100- create U-Boot project (http://sourceforge.net/projects/u-boot) 101- current project page: see http://www.denx.de/wiki/UBoot 102 103 104Names and Spelling: 105=================== 106 107The "official" name of this project is "Das U-Boot". The spelling 108"U-Boot" shall be used in all written text (documentation, comments 109in source files etc.). Example: 110 111 This is the README file for the U-Boot project. 112 113File names etc. shall be based on the string "u-boot". Examples: 114 115 include/asm-ppc/u-boot.h 116 117 #include <asm/u-boot.h> 118 119Variable names, preprocessor constants etc. shall be either based on 120the string "u_boot" or on "U_BOOT". Example: 121 122 U_BOOT_VERSION u_boot_logo 123 IH_OS_U_BOOT u_boot_hush_start 124 125 126Versioning: 127=========== 128 129U-Boot uses a 3 level version number containing a version, a 130sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2", 131sub-version "34", and patchlevel "4". 132 133The patchlevel is used to indicate certain stages of development 134between released versions, i. e. officially released versions of 135U-Boot will always have a patchlevel of "0". 136 137 138Directory Hierarchy: 139==================== 140 141- board Board dependent files 142- common Misc architecture independent functions 143- cpu CPU specific files 144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 145 - arm720t Files specific to ARM 720 CPUs 146 - arm920t Files specific to ARM 920 CPUs 147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU 148 - imx Files specific to Freescale MC9328 i.MX CPUs 149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs 150 - arm925t Files specific to ARM 925 CPUs 151 - arm926ejs Files specific to ARM 926 CPUs 152 - arm1136 Files specific to ARM 1136 CPUs 153 - at32ap Files specific to Atmel AVR32 AP CPUs 154 - i386 Files specific to i386 CPUs 155 - ixp Files specific to Intel XScale IXP CPUs 156 - leon2 Files specific to Gaisler LEON2 SPARC CPU 157 - leon3 Files specific to Gaisler LEON3 SPARC CPU 158 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 159 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 160 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 161 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 162 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 163 - mips Files specific to MIPS CPUs 164 - mpc5xx Files specific to Freescale MPC5xx CPUs 165 - mpc5xxx Files specific to Freescale MPC5xxx CPUs 166 - mpc8xx Files specific to Freescale MPC8xx CPUs 167 - mpc8220 Files specific to Freescale MPC8220 CPUs 168 - mpc824x Files specific to Freescale MPC824x CPUs 169 - mpc8260 Files specific to Freescale MPC8260 CPUs 170 - mpc85xx Files specific to Freescale MPC85xx CPUs 171 - nios Files specific to Altera NIOS CPUs 172 - nios2 Files specific to Altera Nios-II CPUs 173 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs 174 - pxa Files specific to Intel XScale PXA CPUs 175 - s3c44b0 Files specific to Samsung S3C44B0 CPUs 176 - sa1100 Files specific to Intel StrongARM SA1100 CPUs 177- disk Code for disk drive partition handling 178- doc Documentation (don't expect too much) 179- drivers Commonly used device drivers 180- dtt Digital Thermometer and Thermostat drivers 181- examples Example code for standalone applications, etc. 182- include Header Files 183- lib_arm Files generic to ARM architecture 184- lib_avr32 Files generic to AVR32 architecture 185- lib_generic Files generic to all architectures 186- lib_i386 Files generic to i386 architecture 187- lib_m68k Files generic to m68k architecture 188- lib_mips Files generic to MIPS architecture 189- lib_nios Files generic to NIOS architecture 190- lib_ppc Files generic to PowerPC architecture 191- lib_sparc Files generic to SPARC architecture 192- libfdt Library files to support flattened device trees 193- net Networking code 194- post Power On Self Test 195- rtc Real Time Clock drivers 196- tools Tools to build S-Record or U-Boot images, etc. 197 198Software Configuration: 199======================= 200 201Configuration is usually done using C preprocessor defines; the 202rationale behind that is to avoid dead code whenever possible. 203 204There are two classes of configuration variables: 205 206* Configuration _OPTIONS_: 207 These are selectable by the user and have names beginning with 208 "CONFIG_". 209 210* Configuration _SETTINGS_: 211 These depend on the hardware etc. and should not be meddled with if 212 you don't know what you're doing; they have names beginning with 213 "CFG_". 214 215Later we will add a configuration tool - probably similar to or even 216identical to what's used for the Linux kernel. Right now, we have to 217do the configuration by hand, which means creating some symbolic 218links and editing some configuration files. We use the TQM8xxL boards 219as an example here. 220 221 222Selection of Processor Architecture and Board Type: 223--------------------------------------------------- 224 225For all supported boards there are ready-to-use default 226configurations available; just type "make <board_name>_config". 227 228Example: For a TQM823L module type: 229 230 cd u-boot 231 make TQM823L_config 232 233For the Cogent platform, you need to specify the cpu type as well; 234e.g. "make cogent_mpc8xx_config". And also configure the cogent 235directory according to the instructions in cogent/README. 236 237 238Configuration Options: 239---------------------- 240 241Configuration depends on the combination of board and CPU type; all 242such information is kept in a configuration file 243"include/configs/<board_name>.h". 244 245Example: For a TQM823L module, all configuration settings are in 246"include/configs/TQM823L.h". 247 248 249Many of the options are named exactly as the corresponding Linux 250kernel configuration options. The intention is to make it easier to 251build a config tool - later. 252 253 254The following options need to be configured: 255 256- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 257 258- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 259 260- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 261 Define exactly one, e.g. CONFIG_ATSTK1002 262 263- CPU Module Type: (if CONFIG_COGENT is defined) 264 Define exactly one of 265 CONFIG_CMA286_60_OLD 266--- FIXME --- not tested yet: 267 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 268 CONFIG_CMA287_23, CONFIG_CMA287_50 269 270- Motherboard Type: (if CONFIG_COGENT is defined) 271 Define exactly one of 272 CONFIG_CMA101, CONFIG_CMA102 273 274- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 275 Define one or more of 276 CONFIG_CMA302 277 278- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 279 Define one or more of 280 CONFIG_LCD_HEARTBEAT - update a character position on 281 the lcd display every second with 282 a "rotator" |\-/|\-/ 283 284- Board flavour: (if CONFIG_MPC8260ADS is defined) 285 CONFIG_ADSTYPE 286 Possible values are: 287 CFG_8260ADS - original MPC8260ADS 288 CFG_8266ADS - MPC8266ADS 289 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 290 CFG_8272ADS - MPC8272ADS 291 292- MPC824X Family Member (if CONFIG_MPC824X is defined) 293 Define exactly one of 294 CONFIG_MPC8240, CONFIG_MPC8245 295 296- 8xx CPU Options: (if using an MPC8xx cpu) 297 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 298 get_gclk_freq() cannot work 299 e.g. if there is no 32KHz 300 reference PIT/RTC clock 301 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 302 or XTAL/EXTAL) 303 304- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 305 CFG_8xx_CPUCLK_MIN 306 CFG_8xx_CPUCLK_MAX 307 CONFIG_8xx_CPUCLK_DEFAULT 308 See doc/README.MPC866 309 310 CFG_MEASURE_CPUCLK 311 312 Define this to measure the actual CPU clock instead 313 of relying on the correctness of the configured 314 values. Mostly useful for board bringup to make sure 315 the PLL is locked at the intended frequency. Note 316 that this requires a (stable) reference clock (32 kHz 317 RTC clock or CFG_8XX_XIN) 318 319- Intel Monahans options: 320 CFG_MONAHANS_RUN_MODE_OSC_RATIO 321 322 Defines the Monahans run mode to oscillator 323 ratio. Valid values are 8, 16, 24, 31. The core 324 frequency is this value multiplied by 13 MHz. 325 326 CFG_MONAHANS_TURBO_RUN_MODE_RATIO 327 328 Defines the Monahans turbo mode to oscillator 329 ratio. Valid values are 1 (default if undefined) and 330 2. The core frequency as calculated above is multiplied 331 by this value. 332 333- Linux Kernel Interface: 334 CONFIG_CLOCKS_IN_MHZ 335 336 U-Boot stores all clock information in Hz 337 internally. For binary compatibility with older Linux 338 kernels (which expect the clocks passed in the 339 bd_info data to be in MHz) the environment variable 340 "clocks_in_mhz" can be defined so that U-Boot 341 converts clock data to MHZ before passing it to the 342 Linux kernel. 343 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 344 "clocks_in_mhz=1" is automatically included in the 345 default environment. 346 347 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 348 349 When transfering memsize parameter to linux, some versions 350 expect it to be in bytes, others in MB. 351 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 352 353 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE 354 355 New kernel versions are expecting firmware settings to be 356 passed using flattened device trees (based on open firmware 357 concepts). 358 359 CONFIG_OF_LIBFDT 360 * New libfdt-based support 361 * Adds the "fdt" command 362 * The bootm command automatically updates the fdt 363 364 CONFIG_OF_FLAT_TREE 365 * Deprecated, see CONFIG_OF_LIBFDT 366 * Original ft_build.c-based support 367 * Automatically modifies the dft as part of the bootm command 368 * The environment variable "disable_of", when set, 369 disables this functionality. 370 371 OF_CPU - The proper name of the cpus node. 372 OF_SOC - The proper name of the soc node. 373 OF_TBCLK - The timebase frequency. 374 OF_STDOUT_PATH - The path to the console device 375 376 boards with QUICC Engines require OF_QE to set UCC mac addresses 377 378 CONFIG_OF_BOARD_SETUP 379 380 Board code has addition modification that it wants to make 381 to the flat device tree before handing it off to the kernel 382 383 CONFIG_OF_BOOT_CPU 384 385 This define fills in the correct boot cpu in the boot 386 param header, the default value is zero if undefined. 387 388- Serial Ports: 389 CFG_PL010_SERIAL 390 391 Define this if you want support for Amba PrimeCell PL010 UARTs. 392 393 CFG_PL011_SERIAL 394 395 Define this if you want support for Amba PrimeCell PL011 UARTs. 396 397 CONFIG_PL011_CLOCK 398 399 If you have Amba PrimeCell PL011 UARTs, set this variable to 400 the clock speed of the UARTs. 401 402 CONFIG_PL01x_PORTS 403 404 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 405 define this to a list of base addresses for each (supported) 406 port. See e.g. include/configs/versatile.h 407 408 409- Console Interface: 410 Depending on board, define exactly one serial port 411 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 412 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 413 console by defining CONFIG_8xx_CONS_NONE 414 415 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 416 port routines must be defined elsewhere 417 (i.e. serial_init(), serial_getc(), ...) 418 419 CONFIG_CFB_CONSOLE 420 Enables console device for a color framebuffer. Needs following 421 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx) 422 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 423 (default big endian) 424 VIDEO_HW_RECTFILL graphic chip supports 425 rectangle fill 426 (cf. smiLynxEM) 427 VIDEO_HW_BITBLT graphic chip supports 428 bit-blit (cf. smiLynxEM) 429 VIDEO_VISIBLE_COLS visible pixel columns 430 (cols=pitch) 431 VIDEO_VISIBLE_ROWS visible pixel rows 432 VIDEO_PIXEL_SIZE bytes per pixel 433 VIDEO_DATA_FORMAT graphic data format 434 (0-5, cf. cfb_console.c) 435 VIDEO_FB_ADRS framebuffer address 436 VIDEO_KBD_INIT_FCT keyboard int fct 437 (i.e. i8042_kbd_init()) 438 VIDEO_TSTC_FCT test char fct 439 (i.e. i8042_tstc) 440 VIDEO_GETC_FCT get char fct 441 (i.e. i8042_getc) 442 CONFIG_CONSOLE_CURSOR cursor drawing on/off 443 (requires blink timer 444 cf. i8042.c) 445 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 446 CONFIG_CONSOLE_TIME display time/date info in 447 upper right corner 448 (requires CONFIG_CMD_DATE) 449 CONFIG_VIDEO_LOGO display Linux logo in 450 upper left corner 451 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 452 linux_logo.h for logo. 453 Requires CONFIG_VIDEO_LOGO 454 CONFIG_CONSOLE_EXTRA_INFO 455 addional board info beside 456 the logo 457 458 When CONFIG_CFB_CONSOLE is defined, video console is 459 default i/o. Serial console can be forced with 460 environment 'console=serial'. 461 462 When CONFIG_SILENT_CONSOLE is defined, all console 463 messages (by U-Boot and Linux!) can be silenced with 464 the "silent" environment variable. See 465 doc/README.silent for more information. 466 467- Console Baudrate: 468 CONFIG_BAUDRATE - in bps 469 Select one of the baudrates listed in 470 CFG_BAUDRATE_TABLE, see below. 471 CFG_BRGCLK_PRESCALE, baudrate prescale 472 473- Interrupt driven serial port input: 474 CONFIG_SERIAL_SOFTWARE_FIFO 475 476 PPC405GP only. 477 Use an interrupt handler for receiving data on the 478 serial port. It also enables using hardware handshake 479 (RTS/CTS) and UART's built-in FIFO. Set the number of 480 bytes the interrupt driven input buffer should have. 481 482 Leave undefined to disable this feature, including 483 disable the buffer and hardware handshake. 484 485- Console UART Number: 486 CONFIG_UART1_CONSOLE 487 488 AMCC PPC4xx only. 489 If defined internal UART1 (and not UART0) is used 490 as default U-Boot console. 491 492- Boot Delay: CONFIG_BOOTDELAY - in seconds 493 Delay before automatically booting the default image; 494 set to -1 to disable autoboot. 495 496 See doc/README.autoboot for these options that 497 work with CONFIG_BOOTDELAY. None are required. 498 CONFIG_BOOT_RETRY_TIME 499 CONFIG_BOOT_RETRY_MIN 500 CONFIG_AUTOBOOT_KEYED 501 CONFIG_AUTOBOOT_PROMPT 502 CONFIG_AUTOBOOT_DELAY_STR 503 CONFIG_AUTOBOOT_STOP_STR 504 CONFIG_AUTOBOOT_DELAY_STR2 505 CONFIG_AUTOBOOT_STOP_STR2 506 CONFIG_ZERO_BOOTDELAY_CHECK 507 CONFIG_RESET_TO_RETRY 508 509- Autoboot Command: 510 CONFIG_BOOTCOMMAND 511 Only needed when CONFIG_BOOTDELAY is enabled; 512 define a command string that is automatically executed 513 when no character is read on the console interface 514 within "Boot Delay" after reset. 515 516 CONFIG_BOOTARGS 517 This can be used to pass arguments to the bootm 518 command. The value of CONFIG_BOOTARGS goes into the 519 environment value "bootargs". 520 521 CONFIG_RAMBOOT and CONFIG_NFSBOOT 522 The value of these goes into the environment as 523 "ramboot" and "nfsboot" respectively, and can be used 524 as a convenience, when switching between booting from 525 ram and nfs. 526 527- Pre-Boot Commands: 528 CONFIG_PREBOOT 529 530 When this option is #defined, the existence of the 531 environment variable "preboot" will be checked 532 immediately before starting the CONFIG_BOOTDELAY 533 countdown and/or running the auto-boot command resp. 534 entering interactive mode. 535 536 This feature is especially useful when "preboot" is 537 automatically generated or modified. For an example 538 see the LWMON board specific code: here "preboot" is 539 modified when the user holds down a certain 540 combination of keys on the (special) keyboard when 541 booting the systems 542 543- Serial Download Echo Mode: 544 CONFIG_LOADS_ECHO 545 If defined to 1, all characters received during a 546 serial download (using the "loads" command) are 547 echoed back. This might be needed by some terminal 548 emulations (like "cu"), but may as well just take 549 time on others. This setting #define's the initial 550 value of the "loads_echo" environment variable. 551 552- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 553 CONFIG_KGDB_BAUDRATE 554 Select one of the baudrates listed in 555 CFG_BAUDRATE_TABLE, see below. 556 557- Monitor Functions: 558 Monitor commands can be included or excluded 559 from the build by using the #include files 560 "config_cmd_all.h" and #undef'ing unwanted 561 commands, or using "config_cmd_default.h" 562 and augmenting with additional #define's 563 for wanted commands. 564 565 The default command configuration includes all commands 566 except those marked below with a "*". 567 568 CONFIG_CMD_ASKENV * ask for env variable 569 CONFIG_CMD_AUTOSCRIPT Autoscript Support 570 CONFIG_CMD_BDI bdinfo 571 CONFIG_CMD_BEDBUG * Include BedBug Debugger 572 CONFIG_CMD_BMP * BMP support 573 CONFIG_CMD_BSP * Board specific commands 574 CONFIG_CMD_BOOTD bootd 575 CONFIG_CMD_CACHE * icache, dcache 576 CONFIG_CMD_CONSOLE coninfo 577 CONFIG_CMD_DATE * support for RTC, date/time... 578 CONFIG_CMD_DHCP * DHCP support 579 CONFIG_CMD_DIAG * Diagnostics 580 CONFIG_CMD_DOC * Disk-On-Chip Support 581 CONFIG_CMD_DTT * Digital Therm and Thermostat 582 CONFIG_CMD_ECHO echo arguments 583 CONFIG_CMD_EEPROM * EEPROM read/write support 584 CONFIG_CMD_ELF * bootelf, bootvx 585 CONFIG_CMD_ENV saveenv 586 CONFIG_CMD_FDC * Floppy Disk Support 587 CONFIG_CMD_FAT * FAT partition support 588 CONFIG_CMD_FDOS * Dos diskette Support 589 CONFIG_CMD_FLASH flinfo, erase, protect 590 CONFIG_CMD_FPGA FPGA device initialization support 591 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 592 CONFIG_CMD_I2C * I2C serial bus support 593 CONFIG_CMD_IDE * IDE harddisk support 594 CONFIG_CMD_IMI iminfo 595 CONFIG_CMD_IMLS List all found images 596 CONFIG_CMD_IMMAP * IMMR dump support 597 CONFIG_CMD_IRQ * irqinfo 598 CONFIG_CMD_ITEST Integer/string test of 2 values 599 CONFIG_CMD_JFFS2 * JFFS2 Support 600 CONFIG_CMD_KGDB * kgdb 601 CONFIG_CMD_LOADB loadb 602 CONFIG_CMD_LOADS loads 603 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 604 loop, loopw, mtest 605 CONFIG_CMD_MISC Misc functions like sleep etc 606 CONFIG_CMD_MMC * MMC memory mapped support 607 CONFIG_CMD_MII * MII utility commands 608 CONFIG_CMD_NAND * NAND support 609 CONFIG_CMD_NET bootp, tftpboot, rarpboot 610 CONFIG_CMD_PCI * pciinfo 611 CONFIG_CMD_PCMCIA * PCMCIA support 612 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 613 host 614 CONFIG_CMD_PORTIO * Port I/O 615 CONFIG_CMD_REGINFO * Register dump 616 CONFIG_CMD_RUN run command in env variable 617 CONFIG_CMD_SAVES * save S record dump 618 CONFIG_CMD_SCSI * SCSI Support 619 CONFIG_CMD_SDRAM * print SDRAM configuration information 620 (requires CONFIG_CMD_I2C) 621 CONFIG_CMD_SETGETDCR Support for DCR Register access 622 (4xx only) 623 CONFIG_CMD_SPI * SPI serial bus support 624 CONFIG_CMD_USB * USB support 625 CONFIG_CMD_VFD * VFD support (TRAB) 626 CONFIG_CMD_BSP * Board SPecific functions 627 CONFIG_CMD_CDP * Cisco Discover Protocol support 628 CONFIG_CMD_FSL * Microblaze FSL support 629 630 631 EXAMPLE: If you want all functions except of network 632 support you can write: 633 634 #include "config_cmd_all.h" 635 #undef CONFIG_CMD_NET 636 637 Other Commands: 638 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 639 640 Note: Don't enable the "icache" and "dcache" commands 641 (configuration option CONFIG_CMD_CACHE) unless you know 642 what you (and your U-Boot users) are doing. Data 643 cache cannot be enabled on systems like the 8xx or 644 8260 (where accesses to the IMMR region must be 645 uncached), and it cannot be disabled on all other 646 systems where we (mis-) use the data cache to hold an 647 initial stack and some data. 648 649 650 XXX - this list needs to get updated! 651 652- Watchdog: 653 CONFIG_WATCHDOG 654 If this variable is defined, it enables watchdog 655 support. There must be support in the platform specific 656 code for a watchdog. For the 8xx and 8260 CPUs, the 657 SIU Watchdog feature is enabled in the SYPCR 658 register. 659 660- U-Boot Version: 661 CONFIG_VERSION_VARIABLE 662 If this variable is defined, an environment variable 663 named "ver" is created by U-Boot showing the U-Boot 664 version as printed by the "version" command. 665 This variable is readonly. 666 667- Real-Time Clock: 668 669 When CONFIG_CMD_DATE is selected, the type of the RTC 670 has to be selected, too. Define exactly one of the 671 following options: 672 673 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 674 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 675 CONFIG_RTC_MC146818 - use MC146818 RTC 676 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 677 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 678 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 679 CONFIG_RTC_DS164x - use Dallas DS164x RTC 680 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 681 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 682 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 683 684 Note that if the RTC uses I2C, then the I2C interface 685 must also be configured. See I2C Support, below. 686 687- Timestamp Support: 688 689 When CONFIG_TIMESTAMP is selected, the timestamp 690 (date and time) of an image is printed by image 691 commands like bootm or iminfo. This option is 692 automatically enabled when you select CONFIG_CMD_DATE . 693 694- Partition Support: 695 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION 696 and/or CONFIG_ISO_PARTITION 697 698 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 699 CONFIG_CMD_SCSI) you must configure support for at 700 least one partition type as well. 701 702- IDE Reset method: 703 CONFIG_IDE_RESET_ROUTINE - this is defined in several 704 board configurations files but used nowhere! 705 706 CONFIG_IDE_RESET - is this is defined, IDE Reset will 707 be performed by calling the function 708 ide_set_reset(int reset) 709 which has to be defined in a board specific file 710 711- ATAPI Support: 712 CONFIG_ATAPI 713 714 Set this to enable ATAPI support. 715 716- LBA48 Support 717 CONFIG_LBA48 718 719 Set this to enable support for disks larger than 137GB 720 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL 721 Whithout these , LBA48 support uses 32bit variables and will 'only' 722 support disks up to 2.1TB. 723 724 CFG_64BIT_LBA: 725 When enabled, makes the IDE subsystem use 64bit sector addresses. 726 Default is 32bit. 727 728- SCSI Support: 729 At the moment only there is only support for the 730 SYM53C8XX SCSI controller; define 731 CONFIG_SCSI_SYM53C8XX to enable it. 732 733 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and 734 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID * 735 CFG_SCSI_MAX_LUN] can be adjusted to define the 736 maximum numbers of LUNs, SCSI ID's and target 737 devices. 738 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 739 740- NETWORK Support (PCI): 741 CONFIG_E1000 742 Support for Intel 8254x gigabit chips. 743 744 CONFIG_E1000_FALLBACK_MAC 745 default MAC for empty eeprom after production. 746 747 CONFIG_EEPRO100 748 Support for Intel 82557/82559/82559ER chips. 749 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom 750 write routine for first time initialisation. 751 752 CONFIG_TULIP 753 Support for Digital 2114x chips. 754 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 755 modem chip initialisation (KS8761/QS6611). 756 757 CONFIG_NATSEMI 758 Support for National dp83815 chips. 759 760 CONFIG_NS8382X 761 Support for National dp8382[01] gigabit chips. 762 763- NETWORK Support (other): 764 765 CONFIG_DRIVER_LAN91C96 766 Support for SMSC's LAN91C96 chips. 767 768 CONFIG_LAN91C96_BASE 769 Define this to hold the physical address 770 of the LAN91C96's I/O space 771 772 CONFIG_LAN91C96_USE_32_BIT 773 Define this to enable 32 bit addressing 774 775 CONFIG_DRIVER_SMC91111 776 Support for SMSC's LAN91C111 chip 777 778 CONFIG_SMC91111_BASE 779 Define this to hold the physical address 780 of the device (I/O space) 781 782 CONFIG_SMC_USE_32_BIT 783 Define this if data bus is 32 bits 784 785 CONFIG_SMC_USE_IOFUNCS 786 Define this to use i/o functions instead of macros 787 (some hardware wont work with macros) 788 789- USB Support: 790 At the moment only the UHCI host controller is 791 supported (PIP405, MIP405, MPC5200); define 792 CONFIG_USB_UHCI to enable it. 793 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 794 and define CONFIG_USB_STORAGE to enable the USB 795 storage devices. 796 Note: 797 Supported are USB Keyboards and USB Floppy drives 798 (TEAC FD-05PUB). 799 MPC5200 USB requires additional defines: 800 CONFIG_USB_CLOCK 801 for 528 MHz Clock: 0x0001bbbb 802 CONFIG_USB_CONFIG 803 for differential drivers: 0x00001000 804 for single ended drivers: 0x00005000 805 CFG_USB_EVENT_POLL 806 May be defined to allow interrupt polling 807 instead of using asynchronous interrupts 808 809- USB Device: 810 Define the below if you wish to use the USB console. 811 Once firmware is rebuilt from a serial console issue the 812 command "setenv stdin usbtty; setenv stdout usbtty" and 813 attach your usb cable. The Unix command "dmesg" should print 814 it has found a new device. The environment variable usbtty 815 can be set to gserial or cdc_acm to enable your device to 816 appear to a USB host as a Linux gserial device or a 817 Common Device Class Abstract Control Model serial device. 818 If you select usbtty = gserial you should be able to enumerate 819 a Linux host by 820 # modprobe usbserial vendor=0xVendorID product=0xProductID 821 else if using cdc_acm, simply setting the environment 822 variable usbtty to be cdc_acm should suffice. The following 823 might be defined in YourBoardName.h 824 825 CONFIG_USB_DEVICE 826 Define this to build a UDC device 827 828 CONFIG_USB_TTY 829 Define this to have a tty type of device available to 830 talk to the UDC device 831 832 CFG_CONSOLE_IS_IN_ENV 833 Define this if you want stdin, stdout &/or stderr to 834 be set to usbtty. 835 836 mpc8xx: 837 CFG_USB_EXTC_CLK 0xBLAH 838 Derive USB clock from external clock "blah" 839 - CFG_USB_EXTC_CLK 0x02 840 841 CFG_USB_BRG_CLK 0xBLAH 842 Derive USB clock from brgclk 843 - CFG_USB_BRG_CLK 0x04 844 845 If you have a USB-IF assigned VendorID then you may wish to 846 define your own vendor specific values either in BoardName.h 847 or directly in usbd_vendor_info.h. If you don't define 848 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 849 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 850 should pretend to be a Linux device to it's target host. 851 852 CONFIG_USBD_MANUFACTURER 853 Define this string as the name of your company for 854 - CONFIG_USBD_MANUFACTURER "my company" 855 856 CONFIG_USBD_PRODUCT_NAME 857 Define this string as the name of your product 858 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 859 860 CONFIG_USBD_VENDORID 861 Define this as your assigned Vendor ID from the USB 862 Implementors Forum. This *must* be a genuine Vendor ID 863 to avoid polluting the USB namespace. 864 - CONFIG_USBD_VENDORID 0xFFFF 865 866 CONFIG_USBD_PRODUCTID 867 Define this as the unique Product ID 868 for your device 869 - CONFIG_USBD_PRODUCTID 0xFFFF 870 871 872- MMC Support: 873 The MMC controller on the Intel PXA is supported. To 874 enable this define CONFIG_MMC. The MMC can be 875 accessed from the boot prompt by mapping the device 876 to physical memory similar to flash. Command line is 877 enabled with CONFIG_CMD_MMC. The MMC driver also works with 878 the FAT fs. This is enabled with CONFIG_CMD_FAT. 879 880- Journaling Flash filesystem support: 881 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 882 CONFIG_JFFS2_NAND_DEV 883 Define these for a default partition on a NAND device 884 885 CFG_JFFS2_FIRST_SECTOR, 886 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS 887 Define these for a default partition on a NOR device 888 889 CFG_JFFS_CUSTOM_PART 890 Define this to create an own partition. You have to provide a 891 function struct part_info* jffs2_part_info(int part_num) 892 893 If you define only one JFFS2 partition you may also want to 894 #define CFG_JFFS_SINGLE_PART 1 895 to disable the command chpart. This is the default when you 896 have not defined a custom partition 897 898- Keyboard Support: 899 CONFIG_ISA_KEYBOARD 900 901 Define this to enable standard (PC-Style) keyboard 902 support 903 904 CONFIG_I8042_KBD 905 Standard PC keyboard driver with US (is default) and 906 GERMAN key layout (switch via environment 'keymap=de') support. 907 Export function i8042_kbd_init, i8042_tstc and i8042_getc 908 for cfb_console. Supports cursor blinking. 909 910- Video support: 911 CONFIG_VIDEO 912 913 Define this to enable video support (for output to 914 video). 915 916 CONFIG_VIDEO_CT69000 917 918 Enable Chips & Technologies 69000 Video chip 919 920 CONFIG_VIDEO_SMI_LYNXEM 921 Enable Silicon Motion SMI 712/710/810 Video chip. The 922 video output is selected via environment 'videoout' 923 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 924 assumed. 925 926 For the CT69000 and SMI_LYNXEM drivers, videomode is 927 selected via environment 'videomode'. Two diferent ways 928 are possible: 929 - "videomode=num" 'num' is a standard LiLo mode numbers. 930 Following standard modes are supported (* is default): 931 932 Colors 640x480 800x600 1024x768 1152x864 1280x1024 933 -------------+--------------------------------------------- 934 8 bits | 0x301* 0x303 0x305 0x161 0x307 935 15 bits | 0x310 0x313 0x316 0x162 0x319 936 16 bits | 0x311 0x314 0x317 0x163 0x31A 937 24 bits | 0x312 0x315 0x318 ? 0x31B 938 -------------+--------------------------------------------- 939 (i.e. setenv videomode 317; saveenv; reset;) 940 941 - "videomode=bootargs" all the video parameters are parsed 942 from the bootargs. (See drivers/video/videomodes.c) 943 944 945 CONFIG_VIDEO_SED13806 946 Enable Epson SED13806 driver. This driver supports 8bpp 947 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 948 or CONFIG_VIDEO_SED13806_16BPP 949 950- Keyboard Support: 951 CONFIG_KEYBOARD 952 953 Define this to enable a custom keyboard support. 954 This simply calls drv_keyboard_init() which must be 955 defined in your board-specific files. 956 The only board using this so far is RBC823. 957 958- LCD Support: CONFIG_LCD 959 960 Define this to enable LCD support (for output to LCD 961 display); also select one of the supported displays 962 by defining one of these: 963 964 CONFIG_NEC_NL6448AC33: 965 966 NEC NL6448AC33-18. Active, color, single scan. 967 968 CONFIG_NEC_NL6448BC20 969 970 NEC NL6448BC20-08. 6.5", 640x480. 971 Active, color, single scan. 972 973 CONFIG_NEC_NL6448BC33_54 974 975 NEC NL6448BC33-54. 10.4", 640x480. 976 Active, color, single scan. 977 978 CONFIG_SHARP_16x9 979 980 Sharp 320x240. Active, color, single scan. 981 It isn't 16x9, and I am not sure what it is. 982 983 CONFIG_SHARP_LQ64D341 984 985 Sharp LQ64D341 display, 640x480. 986 Active, color, single scan. 987 988 CONFIG_HLD1045 989 990 HLD1045 display, 640x480. 991 Active, color, single scan. 992 993 CONFIG_OPTREX_BW 994 995 Optrex CBL50840-2 NF-FW 99 22 M5 996 or 997 Hitachi LMG6912RPFC-00T 998 or 999 Hitachi SP14Q002 1000 1001 320x240. Black & white. 1002 1003 Normally display is black on white background; define 1004 CFG_WHITE_ON_BLACK to get it inverted. 1005 1006- Splash Screen Support: CONFIG_SPLASH_SCREEN 1007 1008 If this option is set, the environment is checked for 1009 a variable "splashimage". If found, the usual display 1010 of logo, copyright and system information on the LCD 1011 is suppressed and the BMP image at the address 1012 specified in "splashimage" is loaded instead. The 1013 console is redirected to the "nulldev", too. This 1014 allows for a "silent" boot where a splash screen is 1015 loaded very quickly after power-on. 1016 1017- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1018 1019 If this option is set, additionally to standard BMP 1020 images, gzipped BMP images can be displayed via the 1021 splashscreen support or the bmp command. 1022 1023- Compression support: 1024 CONFIG_BZIP2 1025 1026 If this option is set, support for bzip2 compressed 1027 images is included. If not, only uncompressed and gzip 1028 compressed images are supported. 1029 1030 NOTE: the bzip2 algorithm requires a lot of RAM, so 1031 the malloc area (as defined by CFG_MALLOC_LEN) should 1032 be at least 4MB. 1033 1034- MII/PHY support: 1035 CONFIG_PHY_ADDR 1036 1037 The address of PHY on MII bus. 1038 1039 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1040 1041 The clock frequency of the MII bus 1042 1043 CONFIG_PHY_GIGE 1044 1045 If this option is set, support for speed/duplex 1046 detection of Gigabit PHY is included. 1047 1048 CONFIG_PHY_RESET_DELAY 1049 1050 Some PHY like Intel LXT971A need extra delay after 1051 reset before any MII register access is possible. 1052 For such PHY, set this option to the usec delay 1053 required. (minimum 300usec for LXT971A) 1054 1055 CONFIG_PHY_CMD_DELAY (ppc4xx) 1056 1057 Some PHY like Intel LXT971A need extra delay after 1058 command issued before MII status register can be read 1059 1060- Ethernet address: 1061 CONFIG_ETHADDR 1062 CONFIG_ETH2ADDR 1063 CONFIG_ETH3ADDR 1064 1065 Define a default value for ethernet address to use 1066 for the respective ethernet interface, in case this 1067 is not determined automatically. 1068 1069- IP address: 1070 CONFIG_IPADDR 1071 1072 Define a default value for the IP address to use for 1073 the default ethernet interface, in case this is not 1074 determined through e.g. bootp. 1075 1076- Server IP address: 1077 CONFIG_SERVERIP 1078 1079 Defines a default value for theIP address of a TFTP 1080 server to contact when using the "tftboot" command. 1081 1082- Multicast TFTP Mode: 1083 CONFIG_MCAST_TFTP 1084 1085 Defines whether you want to support multicast TFTP as per 1086 rfc-2090; for example to work with atftp. Lets lots of targets 1087 tftp down the same boot image concurrently. Note: the ethernet 1088 driver in use must provide a function: mcast() to join/leave a 1089 multicast group. 1090 1091 CONFIG_BOOTP_RANDOM_DELAY 1092- BOOTP Recovery Mode: 1093 CONFIG_BOOTP_RANDOM_DELAY 1094 1095 If you have many targets in a network that try to 1096 boot using BOOTP, you may want to avoid that all 1097 systems send out BOOTP requests at precisely the same 1098 moment (which would happen for instance at recovery 1099 from a power failure, when all systems will try to 1100 boot, thus flooding the BOOTP server. Defining 1101 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1102 inserted before sending out BOOTP requests. The 1103 following delays are inserted then: 1104 1105 1st BOOTP request: delay 0 ... 1 sec 1106 2nd BOOTP request: delay 0 ... 2 sec 1107 3rd BOOTP request: delay 0 ... 4 sec 1108 4th and following 1109 BOOTP requests: delay 0 ... 8 sec 1110 1111- DHCP Advanced Options: 1112 You can fine tune the DHCP functionality by defining 1113 CONFIG_BOOTP_* symbols: 1114 1115 CONFIG_BOOTP_SUBNETMASK 1116 CONFIG_BOOTP_GATEWAY 1117 CONFIG_BOOTP_HOSTNAME 1118 CONFIG_BOOTP_NISDOMAIN 1119 CONFIG_BOOTP_BOOTPATH 1120 CONFIG_BOOTP_BOOTFILESIZE 1121 CONFIG_BOOTP_DNS 1122 CONFIG_BOOTP_DNS2 1123 CONFIG_BOOTP_SEND_HOSTNAME 1124 CONFIG_BOOTP_NTPSERVER 1125 CONFIG_BOOTP_TIMEOFFSET 1126 CONFIG_BOOTP_VENDOREX 1127 1128 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1129 environment variable, not the BOOTP server. 1130 1131 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1132 serverip from a DHCP server, it is possible that more 1133 than one DNS serverip is offered to the client. 1134 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1135 serverip will be stored in the additional environment 1136 variable "dnsip2". The first DNS serverip is always 1137 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1138 is defined. 1139 1140 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1141 to do a dynamic update of a DNS server. To do this, they 1142 need the hostname of the DHCP requester. 1143 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1144 of the "hostname" environment variable is passed as 1145 option 12 to the DHCP server. 1146 1147 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1148 1149 A 32bit value in microseconds for a delay between 1150 receiving a "DHCP Offer" and sending the "DHCP Request". 1151 This fixes a problem with certain DHCP servers that don't 1152 respond 100% of the time to a "DHCP request". E.g. On an 1153 AT91RM9200 processor running at 180MHz, this delay needed 1154 to be *at least* 15,000 usec before a Windows Server 2003 1155 DHCP server would reply 100% of the time. I recommend at 1156 least 50,000 usec to be safe. The alternative is to hope 1157 that one of the retries will be successful but note that 1158 the DHCP timeout and retry process takes a longer than 1159 this delay. 1160 1161 - CDP Options: 1162 CONFIG_CDP_DEVICE_ID 1163 1164 The device id used in CDP trigger frames. 1165 1166 CONFIG_CDP_DEVICE_ID_PREFIX 1167 1168 A two character string which is prefixed to the MAC address 1169 of the device. 1170 1171 CONFIG_CDP_PORT_ID 1172 1173 A printf format string which contains the ascii name of 1174 the port. Normally is set to "eth%d" which sets 1175 eth0 for the first ethernet, eth1 for the second etc. 1176 1177 CONFIG_CDP_CAPABILITIES 1178 1179 A 32bit integer which indicates the device capabilities; 1180 0x00000010 for a normal host which does not forwards. 1181 1182 CONFIG_CDP_VERSION 1183 1184 An ascii string containing the version of the software. 1185 1186 CONFIG_CDP_PLATFORM 1187 1188 An ascii string containing the name of the platform. 1189 1190 CONFIG_CDP_TRIGGER 1191 1192 A 32bit integer sent on the trigger. 1193 1194 CONFIG_CDP_POWER_CONSUMPTION 1195 1196 A 16bit integer containing the power consumption of the 1197 device in .1 of milliwatts. 1198 1199 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1200 1201 A byte containing the id of the VLAN. 1202 1203- Status LED: CONFIG_STATUS_LED 1204 1205 Several configurations allow to display the current 1206 status using a LED. For instance, the LED will blink 1207 fast while running U-Boot code, stop blinking as 1208 soon as a reply to a BOOTP request was received, and 1209 start blinking slow once the Linux kernel is running 1210 (supported by a status LED driver in the Linux 1211 kernel). Defining CONFIG_STATUS_LED enables this 1212 feature in U-Boot. 1213 1214- CAN Support: CONFIG_CAN_DRIVER 1215 1216 Defining CONFIG_CAN_DRIVER enables CAN driver support 1217 on those systems that support this (optional) 1218 feature, like the TQM8xxL modules. 1219 1220- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1221 1222 These enable I2C serial bus commands. Defining either of 1223 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1224 include the appropriate I2C driver for the selected cpu. 1225 1226 This will allow you to use i2c commands at the u-boot 1227 command line (as long as you set CONFIG_CMD_I2C in 1228 CONFIG_COMMANDS) and communicate with i2c based realtime 1229 clock chips. See common/cmd_i2c.c for a description of the 1230 command line interface. 1231 1232 CONFIG_I2C_CMD_TREE is a recommended option that places 1233 all I2C commands under a single 'i2c' root command. The 1234 older 'imm', 'imd', 'iprobe' etc. commands are considered 1235 deprecated and may disappear in the future. 1236 1237 CONFIG_HARD_I2C selects a hardware I2C controller. 1238 1239 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1240 bit-banging) driver instead of CPM or similar hardware 1241 support for I2C. 1242 1243 There are several other quantities that must also be 1244 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1245 1246 In both cases you will need to define CFG_I2C_SPEED 1247 to be the frequency (in Hz) at which you wish your i2c bus 1248 to run and CFG_I2C_SLAVE to be the address of this node (ie 1249 the cpu's i2c node address). 1250 1251 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c) 1252 sets the cpu up as a master node and so its address should 1253 therefore be cleared to 0 (See, eg, MPC823e User's Manual 1254 p.16-473). So, set CFG_I2C_SLAVE to 0. 1255 1256 That's all that's required for CONFIG_HARD_I2C. 1257 1258 If you use the software i2c interface (CONFIG_SOFT_I2C) 1259 then the following macros need to be defined (examples are 1260 from include/configs/lwmon.h): 1261 1262 I2C_INIT 1263 1264 (Optional). Any commands necessary to enable the I2C 1265 controller or configure ports. 1266 1267 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1268 1269 I2C_PORT 1270 1271 (Only for MPC8260 CPU). The I/O port to use (the code 1272 assumes both bits are on the same port). Valid values 1273 are 0..3 for ports A..D. 1274 1275 I2C_ACTIVE 1276 1277 The code necessary to make the I2C data line active 1278 (driven). If the data line is open collector, this 1279 define can be null. 1280 1281 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1282 1283 I2C_TRISTATE 1284 1285 The code necessary to make the I2C data line tri-stated 1286 (inactive). If the data line is open collector, this 1287 define can be null. 1288 1289 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1290 1291 I2C_READ 1292 1293 Code that returns TRUE if the I2C data line is high, 1294 FALSE if it is low. 1295 1296 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1297 1298 I2C_SDA(bit) 1299 1300 If <bit> is TRUE, sets the I2C data line high. If it 1301 is FALSE, it clears it (low). 1302 1303 eg: #define I2C_SDA(bit) \ 1304 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1305 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1306 1307 I2C_SCL(bit) 1308 1309 If <bit> is TRUE, sets the I2C clock line high. If it 1310 is FALSE, it clears it (low). 1311 1312 eg: #define I2C_SCL(bit) \ 1313 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1314 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1315 1316 I2C_DELAY 1317 1318 This delay is invoked four times per clock cycle so this 1319 controls the rate of data transfer. The data rate thus 1320 is 1 / (I2C_DELAY * 4). Often defined to be something 1321 like: 1322 1323 #define I2C_DELAY udelay(2) 1324 1325 CFG_I2C_INIT_BOARD 1326 1327 When a board is reset during an i2c bus transfer 1328 chips might think that the current transfer is still 1329 in progress. On some boards it is possible to access 1330 the i2c SCLK line directly, either by using the 1331 processor pin as a GPIO or by having a second pin 1332 connected to the bus. If this option is defined a 1333 custom i2c_init_board() routine in boards/xxx/board.c 1334 is run early in the boot sequence. 1335 1336 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1337 1338 This option enables configuration of bi_iic_fast[] flags 1339 in u-boot bd_info structure based on u-boot environment 1340 variable "i2cfast". (see also i2cfast) 1341 1342 CONFIG_I2C_MULTI_BUS 1343 1344 This option allows the use of multiple I2C buses, each of which 1345 must have a controller. At any point in time, only one bus is 1346 active. To switch to a different bus, use the 'i2c dev' command. 1347 Note that bus numbering is zero-based. 1348 1349 CFG_I2C_NOPROBES 1350 1351 This option specifies a list of I2C devices that will be skipped 1352 when the 'i2c probe' command is issued (or 'iprobe' using the legacy 1353 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device 1354 pairs. Otherwise, specify a 1D array of device addresses 1355 1356 e.g. 1357 #undef CONFIG_I2C_MULTI_BUS 1358 #define CFG_I2C_NOPROBES {0x50,0x68} 1359 1360 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1361 1362 #define CONFIG_I2C_MULTI_BUS 1363 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1364 1365 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1366 1367 CFG_SPD_BUS_NUM 1368 1369 If defined, then this indicates the I2C bus number for DDR SPD. 1370 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1371 1372 CFG_RTC_BUS_NUM 1373 1374 If defined, then this indicates the I2C bus number for the RTC. 1375 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1376 1377 CFG_DTT_BUS_NUM 1378 1379 If defined, then this indicates the I2C bus number for the DTT. 1380 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 1381 1382 CONFIG_FSL_I2C 1383 1384 Define this option if you want to use Freescale's I2C driver in 1385 drivers/i2c/fsl_i2c.c. 1386 1387 1388- SPI Support: CONFIG_SPI 1389 1390 Enables SPI driver (so far only tested with 1391 SPI EEPROM, also an instance works with Crystal A/D and 1392 D/As on the SACSng board) 1393 1394 CONFIG_SPI_X 1395 1396 Enables extended (16-bit) SPI EEPROM addressing. 1397 (symmetrical to CONFIG_I2C_X) 1398 1399 CONFIG_SOFT_SPI 1400 1401 Enables a software (bit-bang) SPI driver rather than 1402 using hardware support. This is a general purpose 1403 driver that only requires three general I/O port pins 1404 (two outputs, one input) to function. If this is 1405 defined, the board configuration must define several 1406 SPI configuration items (port pins to use, etc). For 1407 an example, see include/configs/sacsng.h. 1408 1409 CONFIG_HARD_SPI 1410 1411 Enables a hardware SPI driver for general-purpose reads 1412 and writes. As with CONFIG_SOFT_SPI, the board configuration 1413 must define a list of chip-select function pointers. 1414 Currently supported on some MPC8xxx processors. For an 1415 example, see include/configs/mpc8349emds.h. 1416 1417- FPGA Support: CONFIG_FPGA 1418 1419 Enables FPGA subsystem. 1420 1421 CONFIG_FPGA_<vendor> 1422 1423 Enables support for specific chip vendors. 1424 (ALTERA, XILINX) 1425 1426 CONFIG_FPGA_<family> 1427 1428 Enables support for FPGA family. 1429 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1430 1431 CONFIG_FPGA_COUNT 1432 1433 Specify the number of FPGA devices to support. 1434 1435 CFG_FPGA_PROG_FEEDBACK 1436 1437 Enable printing of hash marks during FPGA configuration. 1438 1439 CFG_FPGA_CHECK_BUSY 1440 1441 Enable checks on FPGA configuration interface busy 1442 status by the configuration function. This option 1443 will require a board or device specific function to 1444 be written. 1445 1446 CONFIG_FPGA_DELAY 1447 1448 If defined, a function that provides delays in the FPGA 1449 configuration driver. 1450 1451 CFG_FPGA_CHECK_CTRLC 1452 Allow Control-C to interrupt FPGA configuration 1453 1454 CFG_FPGA_CHECK_ERROR 1455 1456 Check for configuration errors during FPGA bitfile 1457 loading. For example, abort during Virtex II 1458 configuration if the INIT_B line goes low (which 1459 indicated a CRC error). 1460 1461 CFG_FPGA_WAIT_INIT 1462 1463 Maximum time to wait for the INIT_B line to deassert 1464 after PROB_B has been deasserted during a Virtex II 1465 FPGA configuration sequence. The default time is 500 1466 mS. 1467 1468 CFG_FPGA_WAIT_BUSY 1469 1470 Maximum time to wait for BUSY to deassert during 1471 Virtex II FPGA configuration. The default is 5 mS. 1472 1473 CFG_FPGA_WAIT_CONFIG 1474 1475 Time to wait after FPGA configuration. The default is 1476 200 mS. 1477 1478- Configuration Management: 1479 CONFIG_IDENT_STRING 1480 1481 If defined, this string will be added to the U-Boot 1482 version information (U_BOOT_VERSION) 1483 1484- Vendor Parameter Protection: 1485 1486 U-Boot considers the values of the environment 1487 variables "serial#" (Board Serial Number) and 1488 "ethaddr" (Ethernet Address) to be parameters that 1489 are set once by the board vendor / manufacturer, and 1490 protects these variables from casual modification by 1491 the user. Once set, these variables are read-only, 1492 and write or delete attempts are rejected. You can 1493 change this behviour: 1494 1495 If CONFIG_ENV_OVERWRITE is #defined in your config 1496 file, the write protection for vendor parameters is 1497 completely disabled. Anybody can change or delete 1498 these parameters. 1499 1500 Alternatively, if you #define _both_ CONFIG_ETHADDR 1501 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 1502 ethernet address is installed in the environment, 1503 which can be changed exactly ONCE by the user. [The 1504 serial# is unaffected by this, i. e. it remains 1505 read-only.] 1506 1507- Protected RAM: 1508 CONFIG_PRAM 1509 1510 Define this variable to enable the reservation of 1511 "protected RAM", i. e. RAM which is not overwritten 1512 by U-Boot. Define CONFIG_PRAM to hold the number of 1513 kB you want to reserve for pRAM. You can overwrite 1514 this default value by defining an environment 1515 variable "pram" to the number of kB you want to 1516 reserve. Note that the board info structure will 1517 still show the full amount of RAM. If pRAM is 1518 reserved, a new environment variable "mem" will 1519 automatically be defined to hold the amount of 1520 remaining RAM in a form that can be passed as boot 1521 argument to Linux, for instance like that: 1522 1523 setenv bootargs ... mem=\${mem} 1524 saveenv 1525 1526 This way you can tell Linux not to use this memory, 1527 either, which results in a memory region that will 1528 not be affected by reboots. 1529 1530 *WARNING* If your board configuration uses automatic 1531 detection of the RAM size, you must make sure that 1532 this memory test is non-destructive. So far, the 1533 following board configurations are known to be 1534 "pRAM-clean": 1535 1536 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL, 1537 HERMES, IP860, RPXlite, LWMON, LANTEC, 1538 PCU_E, FLAGADM, TQM8260 1539 1540- Error Recovery: 1541 CONFIG_PANIC_HANG 1542 1543 Define this variable to stop the system in case of a 1544 fatal error, so that you have to reset it manually. 1545 This is probably NOT a good idea for an embedded 1546 system where you want to system to reboot 1547 automatically as fast as possible, but it may be 1548 useful during development since you can try to debug 1549 the conditions that lead to the situation. 1550 1551 CONFIG_NET_RETRY_COUNT 1552 1553 This variable defines the number of retries for 1554 network operations like ARP, RARP, TFTP, or BOOTP 1555 before giving up the operation. If not defined, a 1556 default value of 5 is used. 1557 1558- Command Interpreter: 1559 CONFIG_AUTO_COMPLETE 1560 1561 Enable auto completion of commands using TAB. 1562 1563 Note that this feature has NOT been implemented yet 1564 for the "hush" shell. 1565 1566 1567 CFG_HUSH_PARSER 1568 1569 Define this variable to enable the "hush" shell (from 1570 Busybox) as command line interpreter, thus enabling 1571 powerful command line syntax like 1572 if...then...else...fi conditionals or `&&' and '||' 1573 constructs ("shell scripts"). 1574 1575 If undefined, you get the old, much simpler behaviour 1576 with a somewhat smaller memory footprint. 1577 1578 1579 CFG_PROMPT_HUSH_PS2 1580 1581 This defines the secondary prompt string, which is 1582 printed when the command interpreter needs more input 1583 to complete a command. Usually "> ". 1584 1585 Note: 1586 1587 In the current implementation, the local variables 1588 space and global environment variables space are 1589 separated. Local variables are those you define by 1590 simply typing `name=value'. To access a local 1591 variable later on, you have write `$name' or 1592 `${name}'; to execute the contents of a variable 1593 directly type `$name' at the command prompt. 1594 1595 Global environment variables are those you use 1596 setenv/printenv to work with. To run a command stored 1597 in such a variable, you need to use the run command, 1598 and you must not use the '$' sign to access them. 1599 1600 To store commands and special characters in a 1601 variable, please use double quotation marks 1602 surrounding the whole text of the variable, instead 1603 of the backslashes before semicolons and special 1604 symbols. 1605 1606- Commandline Editing and History: 1607 CONFIG_CMDLINE_EDITING 1608 1609 Enable editiong and History functions for interactive 1610 commandline input operations 1611 1612- Default Environment: 1613 CONFIG_EXTRA_ENV_SETTINGS 1614 1615 Define this to contain any number of null terminated 1616 strings (variable = value pairs) that will be part of 1617 the default environment compiled into the boot image. 1618 1619 For example, place something like this in your 1620 board's config file: 1621 1622 #define CONFIG_EXTRA_ENV_SETTINGS \ 1623 "myvar1=value1\0" \ 1624 "myvar2=value2\0" 1625 1626 Warning: This method is based on knowledge about the 1627 internal format how the environment is stored by the 1628 U-Boot code. This is NOT an official, exported 1629 interface! Although it is unlikely that this format 1630 will change soon, there is no guarantee either. 1631 You better know what you are doing here. 1632 1633 Note: overly (ab)use of the default environment is 1634 discouraged. Make sure to check other ways to preset 1635 the environment like the autoscript function or the 1636 boot command first. 1637 1638- DataFlash Support: 1639 CONFIG_HAS_DATAFLASH 1640 1641 Defining this option enables DataFlash features and 1642 allows to read/write in Dataflash via the standard 1643 commands cp, md... 1644 1645- SystemACE Support: 1646 CONFIG_SYSTEMACE 1647 1648 Adding this option adds support for Xilinx SystemACE 1649 chips attached via some sort of local bus. The address 1650 of the chip must alsh be defined in the 1651 CFG_SYSTEMACE_BASE macro. For example: 1652 1653 #define CONFIG_SYSTEMACE 1654 #define CFG_SYSTEMACE_BASE 0xf0000000 1655 1656 When SystemACE support is added, the "ace" device type 1657 becomes available to the fat commands, i.e. fatls. 1658 1659- TFTP Fixed UDP Port: 1660 CONFIG_TFTP_PORT 1661 1662 If this is defined, the environment variable tftpsrcp 1663 is used to supply the TFTP UDP source port value. 1664 If tftpsrcp isn't defined, the normal pseudo-random port 1665 number generator is used. 1666 1667 Also, the environment variable tftpdstp is used to supply 1668 the TFTP UDP destination port value. If tftpdstp isn't 1669 defined, the normal port 69 is used. 1670 1671 The purpose for tftpsrcp is to allow a TFTP server to 1672 blindly start the TFTP transfer using the pre-configured 1673 target IP address and UDP port. This has the effect of 1674 "punching through" the (Windows XP) firewall, allowing 1675 the remainder of the TFTP transfer to proceed normally. 1676 A better solution is to properly configure the firewall, 1677 but sometimes that is not allowed. 1678 1679- Show boot progress: 1680 CONFIG_SHOW_BOOT_PROGRESS 1681 1682 Defining this option allows to add some board- 1683 specific code (calling a user-provided function 1684 "show_boot_progress(int)") that enables you to show 1685 the system's boot progress on some display (for 1686 example, some LED's) on your board. At the moment, 1687 the following checkpoints are implemented: 1688 1689Legacy uImage format: 1690 1691 Arg Where When 1692 1 common/cmd_bootm.c before attempting to boot an image 1693 -1 common/cmd_bootm.c Image header has bad magic number 1694 2 common/cmd_bootm.c Image header has correct magic number 1695 -2 common/cmd_bootm.c Image header has bad checksum 1696 3 common/cmd_bootm.c Image header has correct checksum 1697 -3 common/cmd_bootm.c Image data has bad checksum 1698 4 common/cmd_bootm.c Image data has correct checksum 1699 -4 common/cmd_bootm.c Image is for unsupported architecture 1700 5 common/cmd_bootm.c Architecture check OK 1701 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 1702 6 common/cmd_bootm.c Image Type check OK 1703 -6 common/cmd_bootm.c gunzip uncompression error 1704 -7 common/cmd_bootm.c Unimplemented compression type 1705 7 common/cmd_bootm.c Uncompression OK 1706 8 common/cmd_bootm.c No uncompress/copy overwrite error 1707 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 1708 1709 9 common/image.c Start initial ramdisk verification 1710 -10 common/image.c Ramdisk header has bad magic number 1711 -11 common/image.c Ramdisk header has bad checksum 1712 10 common/image.c Ramdisk header is OK 1713 -12 common/image.c Ramdisk data has bad checksum 1714 11 common/image.c Ramdisk data has correct checksum 1715 12 common/image.c Ramdisk verification complete, start loading 1716 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk) 1717 13 common/image.c Start multifile image verification 1718 14 common/image.c No initial ramdisk, no multifile, continue. 1719 1720 15 lib_<arch>/bootm.c All preparation done, transferring control to OS 1721 1722 -30 lib_ppc/board.c Fatal error, hang the system 1723 -31 post/post.c POST test failed, detected by post_output_backlog() 1724 -32 post/post.c POST test failed, detected by post_run_single() 1725 1726 34 common/cmd_doc.c before loading a Image from a DOC device 1727 -35 common/cmd_doc.c Bad usage of "doc" command 1728 35 common/cmd_doc.c correct usage of "doc" command 1729 -36 common/cmd_doc.c No boot device 1730 36 common/cmd_doc.c correct boot device 1731 -37 common/cmd_doc.c Unknown Chip ID on boot device 1732 37 common/cmd_doc.c correct chip ID found, device available 1733 -38 common/cmd_doc.c Read Error on boot device 1734 38 common/cmd_doc.c reading Image header from DOC device OK 1735 -39 common/cmd_doc.c Image header has bad magic number 1736 39 common/cmd_doc.c Image header has correct magic number 1737 -40 common/cmd_doc.c Error reading Image from DOC device 1738 40 common/cmd_doc.c Image header has correct magic number 1739 41 common/cmd_ide.c before loading a Image from a IDE device 1740 -42 common/cmd_ide.c Bad usage of "ide" command 1741 42 common/cmd_ide.c correct usage of "ide" command 1742 -43 common/cmd_ide.c No boot device 1743 43 common/cmd_ide.c boot device found 1744 -44 common/cmd_ide.c Device not available 1745 44 common/cmd_ide.c Device available 1746 -45 common/cmd_ide.c wrong partition selected 1747 45 common/cmd_ide.c partition selected 1748 -46 common/cmd_ide.c Unknown partition table 1749 46 common/cmd_ide.c valid partition table found 1750 -47 common/cmd_ide.c Invalid partition type 1751 47 common/cmd_ide.c correct partition type 1752 -48 common/cmd_ide.c Error reading Image Header on boot device 1753 48 common/cmd_ide.c reading Image Header from IDE device OK 1754 -49 common/cmd_ide.c Image header has bad magic number 1755 49 common/cmd_ide.c Image header has correct magic number 1756 -50 common/cmd_ide.c Image header has bad checksum 1757 50 common/cmd_ide.c Image header has correct checksum 1758 -51 common/cmd_ide.c Error reading Image from IDE device 1759 51 common/cmd_ide.c reading Image from IDE device OK 1760 52 common/cmd_nand.c before loading a Image from a NAND device 1761 -53 common/cmd_nand.c Bad usage of "nand" command 1762 53 common/cmd_nand.c correct usage of "nand" command 1763 -54 common/cmd_nand.c No boot device 1764 54 common/cmd_nand.c boot device found 1765 -55 common/cmd_nand.c Unknown Chip ID on boot device 1766 55 common/cmd_nand.c correct chip ID found, device available 1767 -56 common/cmd_nand.c Error reading Image Header on boot device 1768 56 common/cmd_nand.c reading Image Header from NAND device OK 1769 -57 common/cmd_nand.c Image header has bad magic number 1770 57 common/cmd_nand.c Image header has correct magic number 1771 -58 common/cmd_nand.c Error reading Image from NAND device 1772 58 common/cmd_nand.c reading Image from NAND device OK 1773 1774 -60 common/env_common.c Environment has a bad CRC, using default 1775 1776 64 net/eth.c starting with Ethernetconfiguration. 1777 -64 net/eth.c no Ethernet found. 1778 65 net/eth.c Ethernet found. 1779 1780 -80 common/cmd_net.c usage wrong 1781 80 common/cmd_net.c before calling NetLoop() 1782 -81 common/cmd_net.c some error in NetLoop() occured 1783 81 common/cmd_net.c NetLoop() back without error 1784 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 1785 82 common/cmd_net.c trying automatic boot 1786 83 common/cmd_net.c running autoscript 1787 -83 common/cmd_net.c some error in automatic boot or autoscript 1788 84 common/cmd_net.c end without errors 1789 1790FIT uImage format: 1791 1792 Arg Where When 1793 100 common/cmd_bootm.c Kernel FIT Image has correct format 1794 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 1795 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 1796 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 1797 102 common/cmd_bootm.c Kernel unit name specified 1798 -103 common/cmd_bootm.c Can't get kernel subimage node offset 1799 103 common/cmd_bootm.c Found configuration node 1800 104 common/cmd_bootm.c Got kernel subimage node offset 1801 -104 common/cmd_bootm.c Kernel subimage hash verification failed 1802 105 common/cmd_bootm.c Kernel subimage hash verification OK 1803 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 1804 106 common/cmd_bootm.c Architecture check OK 1805 -106 common/cmd_bootm.c Kernel subimage has wrong typea 1806 107 common/cmd_bootm.c Kernel subimge type OK 1807 -107 common/cmd_bootm.c Can't get kernel subimage data/size 1808 108 common/cmd_bootm.c Got kernel subimage data/size 1809 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 1810 -109 common/cmd_bootm.c Can't get kernel subimage type 1811 -110 common/cmd_bootm.c Can't get kernel subimage comp 1812 -111 common/cmd_bootm.c Can't get kernel subimage os 1813 -112 common/cmd_bootm.c Can't get kernel subimage load address 1814 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 1815 1816 120 common/image.c Start initial ramdisk verification 1817 -120 common/image.c Ramdisk FIT image has incorrect format 1818 121 common/image.c Ramdisk FIT image has correct format 1819 122 common/image.c No Ramdisk subimage unit name, using configuration 1820 -122 common/image.c Can't get configuration for ramdisk subimage 1821 123 common/image.c Ramdisk unit name specified 1822 -124 common/image.c Can't get ramdisk subimage node offset 1823 125 common/image.c Got ramdisk subimage node offset 1824 -125 common/image.c Ramdisk subimage hash verification failed 1825 126 common/image.c Ramdisk subimage hash verification OK 1826 -126 common/image.c Ramdisk subimage for unsupported architecture 1827 127 common/image.c Architecture check OK 1828 -127 common/image.c Can't get ramdisk subimage data/size 1829 128 common/image.c Got ramdisk subimage data/size 1830 129 common/image.c Can't get ramdisk load address 1831 -129 common/image.c Got ramdisk load address 1832 1833 -130 common/cmd_doc.c Icorrect FIT image format 1834 131 common/cmd_doc.c FIT image format OK 1835 1836 -140 common/cmd_ide.c Icorrect FIT image format 1837 141 common/cmd_ide.c FIT image format OK 1838 1839 -150 common/cmd_nand.c Icorrect FIT image format 1840 151 common/cmd_nand.c FIT image format OK 1841 1842 1843Modem Support: 1844-------------- 1845 1846[so far only for SMDK2400 and TRAB boards] 1847 1848- Modem support endable: 1849 CONFIG_MODEM_SUPPORT 1850 1851- RTS/CTS Flow control enable: 1852 CONFIG_HWFLOW 1853 1854- Modem debug support: 1855 CONFIG_MODEM_SUPPORT_DEBUG 1856 1857 Enables debugging stuff (char screen[1024], dbg()) 1858 for modem support. Useful only with BDI2000. 1859 1860- Interrupt support (PPC): 1861 1862 There are common interrupt_init() and timer_interrupt() 1863 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 1864 for cpu specific initialization. interrupt_init_cpu() 1865 should set decrementer_count to appropriate value. If 1866 cpu resets decrementer automatically after interrupt 1867 (ppc4xx) it should set decrementer_count to zero. 1868 timer_interrupt() calls timer_interrupt_cpu() for cpu 1869 specific handling. If board has watchdog / status_led 1870 / other_activity_monitor it works automatically from 1871 general timer_interrupt(). 1872 1873- General: 1874 1875 In the target system modem support is enabled when a 1876 specific key (key combination) is pressed during 1877 power-on. Otherwise U-Boot will boot normally 1878 (autoboot). The key_pressed() fuction is called from 1879 board_init(). Currently key_pressed() is a dummy 1880 function, returning 1 and thus enabling modem 1881 initialization. 1882 1883 If there are no modem init strings in the 1884 environment, U-Boot proceed to autoboot; the 1885 previous output (banner, info printfs) will be 1886 supressed, though. 1887 1888 See also: doc/README.Modem 1889 1890 1891Configuration Settings: 1892----------------------- 1893 1894- CFG_LONGHELP: Defined when you want long help messages included; 1895 undefine this when you're short of memory. 1896 1897- CFG_PROMPT: This is what U-Boot prints on the console to 1898 prompt for user input. 1899 1900- CFG_CBSIZE: Buffer size for input from the Console 1901 1902- CFG_PBSIZE: Buffer size for Console output 1903 1904- CFG_MAXARGS: max. Number of arguments accepted for monitor commands 1905 1906- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to 1907 the application (usually a Linux kernel) when it is 1908 booted 1909 1910- CFG_BAUDRATE_TABLE: 1911 List of legal baudrate settings for this board. 1912 1913- CFG_CONSOLE_INFO_QUIET 1914 Suppress display of console information at boot. 1915 1916- CFG_CONSOLE_IS_IN_ENV 1917 If the board specific function 1918 extern int overwrite_console (void); 1919 returns 1, the stdin, stderr and stdout are switched to the 1920 serial port, else the settings in the environment are used. 1921 1922- CFG_CONSOLE_OVERWRITE_ROUTINE 1923 Enable the call to overwrite_console(). 1924 1925- CFG_CONSOLE_ENV_OVERWRITE 1926 Enable overwrite of previous console environment settings. 1927 1928- CFG_MEMTEST_START, CFG_MEMTEST_END: 1929 Begin and End addresses of the area used by the 1930 simple memory test. 1931 1932- CFG_ALT_MEMTEST: 1933 Enable an alternate, more extensive memory test. 1934 1935- CFG_MEMTEST_SCRATCH: 1936 Scratch address used by the alternate memory test 1937 You only need to set this if address zero isn't writeable 1938 1939- CFG_MEM_TOP_HIDE (PPC only): 1940 If CFG_MEM_TOP_HIDE is defined in the board config header, 1941 this specified memory area will get subtracted from the top 1942 (end) of ram and won't get "touched" at all by U-Boot. By 1943 fixing up gd->ram_size the Linux kernel should gets passed 1944 the now "corrected" memory size and won't touch it either. 1945 This should work for arch/ppc and arch/powerpc. Only Linux 1946 board ports in arch/powerpc with bootwrapper support that 1947 recalculate the memory size from the SDRAM controller setup 1948 will have to get fixed in Linux additionally. 1949 1950 This option can be used as a workaround for the 440EPx/GRx 1951 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 1952 be touched. 1953 1954 WARNING: Please make sure that this value is a multiple of 1955 the Linux page size (normally 4k). If this is not the case, 1956 then the end address of the Linux memory will be located at a 1957 non page size aligned address and this could cause major 1958 problems. 1959 1960- CFG_TFTP_LOADADDR: 1961 Default load address for network file downloads 1962 1963- CFG_LOADS_BAUD_CHANGE: 1964 Enable temporary baudrate change while serial download 1965 1966- CFG_SDRAM_BASE: 1967 Physical start address of SDRAM. _Must_ be 0 here. 1968 1969- CFG_MBIO_BASE: 1970 Physical start address of Motherboard I/O (if using a 1971 Cogent motherboard) 1972 1973- CFG_FLASH_BASE: 1974 Physical start address of Flash memory. 1975 1976- CFG_MONITOR_BASE: 1977 Physical start address of boot monitor code (set by 1978 make config files to be same as the text base address 1979 (TEXT_BASE) used when linking) - same as 1980 CFG_FLASH_BASE when booting from flash. 1981 1982- CFG_MONITOR_LEN: 1983 Size of memory reserved for monitor code, used to 1984 determine _at_compile_time_ (!) if the environment is 1985 embedded within the U-Boot image, or in a separate 1986 flash sector. 1987 1988- CFG_MALLOC_LEN: 1989 Size of DRAM reserved for malloc() use. 1990 1991- CFG_BOOTM_LEN: 1992 Normally compressed uImages are limited to an 1993 uncompressed size of 8 MBytes. If this is not enough, 1994 you can define CFG_BOOTM_LEN in your board config file 1995 to adjust this setting to your needs. 1996 1997- CFG_BOOTMAPSZ: 1998 Maximum size of memory mapped by the startup code of 1999 the Linux kernel; all data that must be processed by 2000 the Linux kernel (bd_info, boot arguments, eventually 2001 initrd image) must be put below this limit. 2002 2003- CFG_MAX_FLASH_BANKS: 2004 Max number of Flash memory banks 2005 2006- CFG_MAX_FLASH_SECT: 2007 Max number of sectors on a Flash chip 2008 2009- CFG_FLASH_ERASE_TOUT: 2010 Timeout for Flash erase operations (in ms) 2011 2012- CFG_FLASH_WRITE_TOUT: 2013 Timeout for Flash write operations (in ms) 2014 2015- CFG_FLASH_LOCK_TOUT 2016 Timeout for Flash set sector lock bit operation (in ms) 2017 2018- CFG_FLASH_UNLOCK_TOUT 2019 Timeout for Flash clear lock bits operation (in ms) 2020 2021- CFG_FLASH_PROTECTION 2022 If defined, hardware flash sectors protection is used 2023 instead of U-Boot software protection. 2024 2025- CFG_DIRECT_FLASH_TFTP: 2026 2027 Enable TFTP transfers directly to flash memory; 2028 without this option such a download has to be 2029 performed in two steps: (1) download to RAM, and (2) 2030 copy from RAM to flash. 2031 2032 The two-step approach is usually more reliable, since 2033 you can check if the download worked before you erase 2034 the flash, but in some situations (when sytem RAM is 2035 too limited to allow for a tempory copy of the 2036 downloaded image) this option may be very useful. 2037 2038- CFG_FLASH_CFI: 2039 Define if the flash driver uses extra elements in the 2040 common flash structure for storing flash geometry. 2041 2042- CFG_FLASH_CFI_DRIVER 2043 This option also enables the building of the cfi_flash driver 2044 in the drivers directory 2045 2046- CFG_FLASH_QUIET_TEST 2047 If this option is defined, the common CFI flash doesn't 2048 print it's warning upon not recognized FLASH banks. This 2049 is useful, if some of the configured banks are only 2050 optionally available. 2051 2052- CONFIG_FLASH_SHOW_PROGRESS 2053 If defined (must be an integer), print out countdown 2054 digits and dots. Recommended value: 45 (9..1) for 80 2055 column displays, 15 (3..1) for 40 column displays. 2056 2057- CFG_RX_ETH_BUFFER: 2058 Defines the number of ethernet receive buffers. On some 2059 ethernet controllers it is recommended to set this value 2060 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2061 buffers can be full shortly after enabling the interface 2062 on high ethernet traffic. 2063 Defaults to 4 if not defined. 2064 2065The following definitions that deal with the placement and management 2066of environment data (variable area); in general, we support the 2067following configurations: 2068 2069- CFG_ENV_IS_IN_FLASH: 2070 2071 Define this if the environment is in flash memory. 2072 2073 a) The environment occupies one whole flash sector, which is 2074 "embedded" in the text segment with the U-Boot code. This 2075 happens usually with "bottom boot sector" or "top boot 2076 sector" type flash chips, which have several smaller 2077 sectors at the start or the end. For instance, such a 2078 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 2079 such a case you would place the environment in one of the 2080 4 kB sectors - with U-Boot code before and after it. With 2081 "top boot sector" type flash chips, you would put the 2082 environment in one of the last sectors, leaving a gap 2083 between U-Boot and the environment. 2084 2085 - CFG_ENV_OFFSET: 2086 2087 Offset of environment data (variable area) to the 2088 beginning of flash memory; for instance, with bottom boot 2089 type flash chips the second sector can be used: the offset 2090 for this sector is given here. 2091 2092 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE. 2093 2094 - CFG_ENV_ADDR: 2095 2096 This is just another way to specify the start address of 2097 the flash sector containing the environment (instead of 2098 CFG_ENV_OFFSET). 2099 2100 - CFG_ENV_SECT_SIZE: 2101 2102 Size of the sector containing the environment. 2103 2104 2105 b) Sometimes flash chips have few, equal sized, BIG sectors. 2106 In such a case you don't want to spend a whole sector for 2107 the environment. 2108 2109 - CFG_ENV_SIZE: 2110 2111 If you use this in combination with CFG_ENV_IS_IN_FLASH 2112 and CFG_ENV_SECT_SIZE, you can specify to use only a part 2113 of this flash sector for the environment. This saves 2114 memory for the RAM copy of the environment. 2115 2116 It may also save flash memory if you decide to use this 2117 when your environment is "embedded" within U-Boot code, 2118 since then the remainder of the flash sector could be used 2119 for U-Boot code. It should be pointed out that this is 2120 STRONGLY DISCOURAGED from a robustness point of view: 2121 updating the environment in flash makes it always 2122 necessary to erase the WHOLE sector. If something goes 2123 wrong before the contents has been restored from a copy in 2124 RAM, your target system will be dead. 2125 2126 - CFG_ENV_ADDR_REDUND 2127 CFG_ENV_SIZE_REDUND 2128 2129 These settings describe a second storage area used to hold 2130 a redundand copy of the environment data, so that there is 2131 a valid backup copy in case there is a power failure during 2132 a "saveenv" operation. 2133 2134BE CAREFUL! Any changes to the flash layout, and some changes to the 2135source code will make it necessary to adapt <board>/u-boot.lds* 2136accordingly! 2137 2138 2139- CFG_ENV_IS_IN_NVRAM: 2140 2141 Define this if you have some non-volatile memory device 2142 (NVRAM, battery buffered SRAM) which you want to use for the 2143 environment. 2144 2145 - CFG_ENV_ADDR: 2146 - CFG_ENV_SIZE: 2147 2148 These two #defines are used to determin the memory area you 2149 want to use for environment. It is assumed that this memory 2150 can just be read and written to, without any special 2151 provision. 2152 2153BE CAREFUL! The first access to the environment happens quite early 2154in U-Boot initalization (when we try to get the setting of for the 2155console baudrate). You *MUST* have mappend your NVRAM area then, or 2156U-Boot will hang. 2157 2158Please note that even with NVRAM we still use a copy of the 2159environment in RAM: we could work on NVRAM directly, but we want to 2160keep settings there always unmodified except somebody uses "saveenv" 2161to save the current settings. 2162 2163 2164- CFG_ENV_IS_IN_EEPROM: 2165 2166 Use this if you have an EEPROM or similar serial access 2167 device and a driver for it. 2168 2169 - CFG_ENV_OFFSET: 2170 - CFG_ENV_SIZE: 2171 2172 These two #defines specify the offset and size of the 2173 environment area within the total memory of your EEPROM. 2174 2175 - CFG_I2C_EEPROM_ADDR: 2176 If defined, specified the chip address of the EEPROM device. 2177 The default address is zero. 2178 2179 - CFG_EEPROM_PAGE_WRITE_BITS: 2180 If defined, the number of bits used to address bytes in a 2181 single page in the EEPROM device. A 64 byte page, for example 2182 would require six bits. 2183 2184 - CFG_EEPROM_PAGE_WRITE_DELAY_MS: 2185 If defined, the number of milliseconds to delay between 2186 page writes. The default is zero milliseconds. 2187 2188 - CFG_I2C_EEPROM_ADDR_LEN: 2189 The length in bytes of the EEPROM memory array address. Note 2190 that this is NOT the chip address length! 2191 2192 - CFG_I2C_EEPROM_ADDR_OVERFLOW: 2193 EEPROM chips that implement "address overflow" are ones 2194 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 2195 address and the extra bits end up in the "chip address" bit 2196 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 2197 byte chips. 2198 2199 Note that we consider the length of the address field to 2200 still be one byte because the extra address bits are hidden 2201 in the chip address. 2202 2203 - CFG_EEPROM_SIZE: 2204 The size in bytes of the EEPROM device. 2205 2206 2207- CFG_ENV_IS_IN_DATAFLASH: 2208 2209 Define this if you have a DataFlash memory device which you 2210 want to use for the environment. 2211 2212 - CFG_ENV_OFFSET: 2213 - CFG_ENV_ADDR: 2214 - CFG_ENV_SIZE: 2215 2216 These three #defines specify the offset and size of the 2217 environment area within the total memory of your DataFlash placed 2218 at the specified address. 2219 2220- CFG_ENV_IS_IN_NAND: 2221 2222 Define this if you have a NAND device which you want to use 2223 for the environment. 2224 2225 - CFG_ENV_OFFSET: 2226 - CFG_ENV_SIZE: 2227 2228 These two #defines specify the offset and size of the environment 2229 area within the first NAND device. 2230 2231 - CFG_ENV_OFFSET_REDUND 2232 2233 This setting describes a second storage area of CFG_ENV_SIZE 2234 size used to hold a redundant copy of the environment data, 2235 so that there is a valid backup copy in case there is a 2236 power failure during a "saveenv" operation. 2237 2238 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned 2239 to a block boundary, and CFG_ENV_SIZE must be a multiple of 2240 the NAND devices block size. 2241 2242- CFG_SPI_INIT_OFFSET 2243 2244 Defines offset to the initial SPI buffer area in DPRAM. The 2245 area is used at an early stage (ROM part) if the environment 2246 is configured to reside in the SPI EEPROM: We need a 520 byte 2247 scratch DPRAM area. It is used between the two initialization 2248 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 2249 to be a good choice since it makes it far enough from the 2250 start of the data area as well as from the stack pointer. 2251 2252Please note that the environment is read-only until the monitor 2253has been relocated to RAM and a RAM copy of the environment has been 2254created; also, when using EEPROM you will have to use getenv_r() 2255until then to read environment variables. 2256 2257The environment is protected by a CRC32 checksum. Before the monitor 2258is relocated into RAM, as a result of a bad CRC you will be working 2259with the compiled-in default environment - *silently*!!! [This is 2260necessary, because the first environment variable we need is the 2261"baudrate" setting for the console - if we have a bad CRC, we don't 2262have any device yet where we could complain.] 2263 2264Note: once the monitor has been relocated, then it will complain if 2265the default environment is used; a new CRC is computed as soon as you 2266use the "saveenv" command to store a valid environment. 2267 2268- CFG_FAULT_ECHO_LINK_DOWN: 2269 Echo the inverted Ethernet link state to the fault LED. 2270 2271 Note: If this option is active, then CFG_FAULT_MII_ADDR 2272 also needs to be defined. 2273 2274- CFG_FAULT_MII_ADDR: 2275 MII address of the PHY to check for the Ethernet link state. 2276 2277- CFG_64BIT_VSPRINTF: 2278 Makes vsprintf (and all *printf functions) support printing 2279 of 64bit values by using the L quantifier 2280 2281- CFG_64BIT_STRTOUL: 2282 Adds simple_strtoull that returns a 64bit value 2283 2284Low Level (hardware related) configuration options: 2285--------------------------------------------------- 2286 2287- CFG_CACHELINE_SIZE: 2288 Cache Line Size of the CPU. 2289 2290- CFG_DEFAULT_IMMR: 2291 Default address of the IMMR after system reset. 2292 2293 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 2294 and RPXsuper) to be able to adjust the position of 2295 the IMMR register after a reset. 2296 2297- Floppy Disk Support: 2298 CFG_FDC_DRIVE_NUMBER 2299 2300 the default drive number (default value 0) 2301 2302 CFG_ISA_IO_STRIDE 2303 2304 defines the spacing between fdc chipset registers 2305 (default value 1) 2306 2307 CFG_ISA_IO_OFFSET 2308 2309 defines the offset of register from address. It 2310 depends on which part of the data bus is connected to 2311 the fdc chipset. (default value 0) 2312 2313 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and 2314 CFG_FDC_DRIVE_NUMBER are undefined, they take their 2315 default value. 2316 2317 if CFG_FDC_HW_INIT is defined, then the function 2318 fdc_hw_init() is called at the beginning of the FDC 2319 setup. fdc_hw_init() must be provided by the board 2320 source code. It is used to make hardware dependant 2321 initializations. 2322 2323- CFG_IMMR: Physical address of the Internal Memory. 2324 DO NOT CHANGE unless you know exactly what you're 2325 doing! (11-4) [MPC8xx/82xx systems only] 2326 2327- CFG_INIT_RAM_ADDR: 2328 2329 Start address of memory area that can be used for 2330 initial data and stack; please note that this must be 2331 writable memory that is working WITHOUT special 2332 initialization, i. e. you CANNOT use normal RAM which 2333 will become available only after programming the 2334 memory controller and running certain initialization 2335 sequences. 2336 2337 U-Boot uses the following memory types: 2338 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 2339 - MPC824X: data cache 2340 - PPC4xx: data cache 2341 2342- CFG_GBL_DATA_OFFSET: 2343 2344 Offset of the initial data structure in the memory 2345 area defined by CFG_INIT_RAM_ADDR. Usually 2346 CFG_GBL_DATA_OFFSET is chosen such that the initial 2347 data is located at the end of the available space 2348 (sometimes written as (CFG_INIT_RAM_END - 2349 CFG_INIT_DATA_SIZE), and the initial stack is just 2350 below that area (growing from (CFG_INIT_RAM_ADDR + 2351 CFG_GBL_DATA_OFFSET) downward. 2352 2353 Note: 2354 On the MPC824X (or other systems that use the data 2355 cache for initial memory) the address chosen for 2356 CFG_INIT_RAM_ADDR is basically arbitrary - it must 2357 point to an otherwise UNUSED address space between 2358 the top of RAM and the start of the PCI space. 2359 2360- CFG_SIUMCR: SIU Module Configuration (11-6) 2361 2362- CFG_SYPCR: System Protection Control (11-9) 2363 2364- CFG_TBSCR: Time Base Status and Control (11-26) 2365 2366- CFG_PISCR: Periodic Interrupt Status and Control (11-31) 2367 2368- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 2369 2370- CFG_SCCR: System Clock and reset Control Register (15-27) 2371 2372- CFG_OR_TIMING_SDRAM: 2373 SDRAM timing 2374 2375- CFG_MAMR_PTA: 2376 periodic timer for refresh 2377 2378- CFG_DER: Debug Event Register (37-47) 2379 2380- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM, 2381 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP, 2382 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM, 2383 CFG_BR1_PRELIM: 2384 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 2385 2386- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 2387 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM, 2388 CFG_OR3_PRELIM, CFG_BR3_PRELIM: 2389 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 2390 2391- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K, 2392 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL: 2393 Machine Mode Register and Memory Periodic Timer 2394 Prescaler definitions (SDRAM timing) 2395 2396- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]: 2397 enable I2C microcode relocation patch (MPC8xx); 2398 define relocation offset in DPRAM [DSP2] 2399 2400- CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]: 2401 enable SMC microcode relocation patch (MPC8xx); 2402 define relocation offset in DPRAM [SMC1] 2403 2404- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]: 2405 enable SPI microcode relocation patch (MPC8xx); 2406 define relocation offset in DPRAM [SCC4] 2407 2408- CFG_USE_OSCCLK: 2409 Use OSCM clock mode on MBX8xx board. Be careful, 2410 wrong setting might damage your board. Read 2411 doc/README.MBX before setting this variable! 2412 2413- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 2414 Offset of the bootmode word in DPRAM used by post 2415 (Power On Self Tests). This definition overrides 2416 #define'd default value in commproc.h resp. 2417 cpm_8260.h. 2418 2419- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB, 2420 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL, 2421 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS, 2422 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB, 2423 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 2424 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL, 2425 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE, 2426 CFG_POCMR2_MASK_ATTRIB: (MPC826x only) 2427 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. 2428 2429- CONFIG_SPD_EEPROM 2430 Get DDR timing information from an I2C EEPROM. Common 2431 with pluggable memory modules such as SODIMMs 2432 2433 SPD_EEPROM_ADDRESS 2434 I2C address of the SPD EEPROM 2435 2436- CFG_SPD_BUS_NUM 2437 If SPD EEPROM is on an I2C bus other than the first 2438 one, specify here. Note that the value must resolve 2439 to something your driver can deal with. 2440 2441- CFG_83XX_DDR_USES_CS0 2442 Only for 83xx systems. If specified, then DDR should 2443 be configured using CS0 and CS1 instead of CS2 and CS3. 2444 2445- CFG_83XX_DDR_USES_CS0 2446 Only for 83xx systems. If specified, then DDR should 2447 be configured using CS0 and CS1 instead of CS2 and CS3. 2448 2449- CONFIG_ETHER_ON_FEC[12] 2450 Define to enable FEC[12] on a 8xx series processor. 2451 2452- CONFIG_FEC[12]_PHY 2453 Define to the hardcoded PHY address which corresponds 2454 to the given FEC; i. e. 2455 #define CONFIG_FEC1_PHY 4 2456 means that the PHY with address 4 is connected to FEC1 2457 2458 When set to -1, means to probe for first available. 2459 2460- CONFIG_FEC[12]_PHY_NORXERR 2461 The PHY does not have a RXERR line (RMII only). 2462 (so program the FEC to ignore it). 2463 2464- CONFIG_RMII 2465 Enable RMII mode for all FECs. 2466 Note that this is a global option, we can't 2467 have one FEC in standard MII mode and another in RMII mode. 2468 2469- CONFIG_CRC32_VERIFY 2470 Add a verify option to the crc32 command. 2471 The syntax is: 2472 2473 => crc32 -v <address> <count> <crc32> 2474 2475 Where address/count indicate a memory area 2476 and crc32 is the correct crc32 which the 2477 area should have. 2478 2479- CONFIG_LOOPW 2480 Add the "loopw" memory command. This only takes effect if 2481 the memory commands are activated globally (CONFIG_CMD_MEM). 2482 2483- CONFIG_MX_CYCLIC 2484 Add the "mdc" and "mwc" memory commands. These are cyclic 2485 "md/mw" commands. 2486 Examples: 2487 2488 => mdc.b 10 4 500 2489 This command will print 4 bytes (10,11,12,13) each 500 ms. 2490 2491 => mwc.l 100 12345678 10 2492 This command will write 12345678 to address 100 all 10 ms. 2493 2494 This only takes effect if the memory commands are activated 2495 globally (CONFIG_CMD_MEM). 2496 2497- CONFIG_SKIP_LOWLEVEL_INIT 2498- CONFIG_SKIP_RELOCATE_UBOOT 2499 2500 [ARM only] If these variables are defined, then 2501 certain low level initializations (like setting up 2502 the memory controller) are omitted and/or U-Boot does 2503 not relocate itself into RAM. 2504 Normally these variables MUST NOT be defined. The 2505 only exception is when U-Boot is loaded (to RAM) by 2506 some other boot loader or by a debugger which 2507 performs these intializations itself. 2508 2509 2510Building the Software: 2511====================== 2512 2513Building U-Boot has been tested in several native build environments 2514and in many different cross environments. Of course we cannot support 2515all possibly existing versions of cross development tools in all 2516(potentially obsolete) versions. In case of tool chain problems we 2517recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 2518which is extensively used to build and test U-Boot. 2519 2520If you are not using a native environment, it is assumed that you 2521have GNU cross compiling tools available in your path. In this case, 2522you must set the environment variable CROSS_COMPILE in your shell. 2523Note that no changes to the Makefile or any other source files are 2524necessary. For example using the ELDK on a 4xx CPU, please enter: 2525 2526 $ CROSS_COMPILE=ppc_4xx- 2527 $ export CROSS_COMPILE 2528 2529U-Boot is intended to be simple to build. After installing the 2530sources you must configure U-Boot for one specific board type. This 2531is done by typing: 2532 2533 make NAME_config 2534 2535where "NAME_config" is the name of one of the existing configu- 2536rations; see the main Makefile for supported names. 2537 2538Note: for some board special configuration names may exist; check if 2539 additional information is available from the board vendor; for 2540 instance, the TQM823L systems are available without (standard) 2541 or with LCD support. You can select such additional "features" 2542 when chosing the configuration, i. e. 2543 2544 make TQM823L_config 2545 - will configure for a plain TQM823L, i. e. no LCD support 2546 2547 make TQM823L_LCD_config 2548 - will configure for a TQM823L with U-Boot console on LCD 2549 2550 etc. 2551 2552 2553Finally, type "make all", and you should get some working U-Boot 2554images ready for download to / installation on your system: 2555 2556- "u-boot.bin" is a raw binary image 2557- "u-boot" is an image in ELF binary format 2558- "u-boot.srec" is in Motorola S-Record format 2559 2560By default the build is performed locally and the objects are saved 2561in the source directory. One of the two methods can be used to change 2562this behavior and build U-Boot to some external directory: 2563 25641. Add O= to the make command line invocations: 2565 2566 make O=/tmp/build distclean 2567 make O=/tmp/build NAME_config 2568 make O=/tmp/build all 2569 25702. Set environment variable BUILD_DIR to point to the desired location: 2571 2572 export BUILD_DIR=/tmp/build 2573 make distclean 2574 make NAME_config 2575 make all 2576 2577Note that the command line "O=" setting overrides the BUILD_DIR environment 2578variable. 2579 2580 2581Please be aware that the Makefiles assume you are using GNU make, so 2582for instance on NetBSD you might need to use "gmake" instead of 2583native "make". 2584 2585 2586If the system board that you have is not listed, then you will need 2587to port U-Boot to your hardware platform. To do this, follow these 2588steps: 2589 25901. Add a new configuration option for your board to the toplevel 2591 "Makefile" and to the "MAKEALL" script, using the existing 2592 entries as examples. Note that here and at many other places 2593 boards and other names are listed in alphabetical sort order. Please 2594 keep this order. 25952. Create a new directory to hold your board specific code. Add any 2596 files you need. In your board directory, you will need at least 2597 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 25983. Create a new configuration file "include/configs/<board>.h" for 2599 your board 26003. If you're porting U-Boot to a new CPU, then also create a new 2601 directory to hold your CPU specific code. Add any files you need. 26024. Run "make <board>_config" with your new name. 26035. Type "make", and you should get a working "u-boot.srec" file 2604 to be installed on your target system. 26056. Debug and solve any problems that might arise. 2606 [Of course, this last step is much harder than it sounds.] 2607 2608 2609Testing of U-Boot Modifications, Ports to New Hardware, etc.: 2610============================================================== 2611 2612If you have modified U-Boot sources (for instance added a new board 2613or support for new devices, a new CPU, etc.) you are expected to 2614provide feedback to the other developers. The feedback normally takes 2615the form of a "patch", i. e. a context diff against a certain (latest 2616official or latest in the git repository) version of U-Boot sources. 2617 2618But before you submit such a patch, please verify that your modifi- 2619cation did not break existing code. At least make sure that *ALL* of 2620the supported boards compile WITHOUT ANY compiler warnings. To do so, 2621just run the "MAKEALL" script, which will configure and build U-Boot 2622for ALL supported system. Be warned, this will take a while. You can 2623select which (cross) compiler to use by passing a `CROSS_COMPILE' 2624environment variable to the script, i. e. to use the ELDK cross tools 2625you can type 2626 2627 CROSS_COMPILE=ppc_8xx- MAKEALL 2628 2629or to build on a native PowerPC system you can type 2630 2631 CROSS_COMPILE=' ' MAKEALL 2632 2633When using the MAKEALL script, the default behaviour is to build 2634U-Boot in the source directory. This location can be changed by 2635setting the BUILD_DIR environment variable. Also, for each target 2636built, the MAKEALL script saves two log files (<target>.ERR and 2637<target>.MAKEALL) in the <source dir>/LOG directory. This default 2638location can be changed by setting the MAKEALL_LOGDIR environment 2639variable. For example: 2640 2641 export BUILD_DIR=/tmp/build 2642 export MAKEALL_LOGDIR=/tmp/log 2643 CROSS_COMPILE=ppc_8xx- MAKEALL 2644 2645With the above settings build objects are saved in the /tmp/build, 2646log files are saved in the /tmp/log and the source tree remains clean 2647during the whole build process. 2648 2649 2650See also "U-Boot Porting Guide" below. 2651 2652 2653Monitor Commands - Overview: 2654============================ 2655 2656go - start application at address 'addr' 2657run - run commands in an environment variable 2658bootm - boot application image from memory 2659bootp - boot image via network using BootP/TFTP protocol 2660tftpboot- boot image via network using TFTP protocol 2661 and env variables "ipaddr" and "serverip" 2662 (and eventually "gatewayip") 2663rarpboot- boot image via network using RARP/TFTP protocol 2664diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 2665loads - load S-Record file over serial line 2666loadb - load binary file over serial line (kermit mode) 2667md - memory display 2668mm - memory modify (auto-incrementing) 2669nm - memory modify (constant address) 2670mw - memory write (fill) 2671cp - memory copy 2672cmp - memory compare 2673crc32 - checksum calculation 2674imd - i2c memory display 2675imm - i2c memory modify (auto-incrementing) 2676inm - i2c memory modify (constant address) 2677imw - i2c memory write (fill) 2678icrc32 - i2c checksum calculation 2679iprobe - probe to discover valid I2C chip addresses 2680iloop - infinite loop on address range 2681isdram - print SDRAM configuration information 2682sspi - SPI utility commands 2683base - print or set address offset 2684printenv- print environment variables 2685setenv - set environment variables 2686saveenv - save environment variables to persistent storage 2687protect - enable or disable FLASH write protection 2688erase - erase FLASH memory 2689flinfo - print FLASH memory information 2690bdinfo - print Board Info structure 2691iminfo - print header information for application image 2692coninfo - print console devices and informations 2693ide - IDE sub-system 2694loop - infinite loop on address range 2695loopw - infinite write loop on address range 2696mtest - simple RAM test 2697icache - enable or disable instruction cache 2698dcache - enable or disable data cache 2699reset - Perform RESET of the CPU 2700echo - echo args to console 2701version - print monitor version 2702help - print online help 2703? - alias for 'help' 2704 2705 2706Monitor Commands - Detailed Description: 2707======================================== 2708 2709TODO. 2710 2711For now: just type "help <command>". 2712 2713 2714Environment Variables: 2715====================== 2716 2717U-Boot supports user configuration using Environment Variables which 2718can be made persistent by saving to Flash memory. 2719 2720Environment Variables are set using "setenv", printed using 2721"printenv", and saved to Flash using "saveenv". Using "setenv" 2722without a value can be used to delete a variable from the 2723environment. As long as you don't save the environment you are 2724working with an in-memory copy. In case the Flash area containing the 2725environment is erased by accident, a default environment is provided. 2726 2727Some configuration options can be set using Environment Variables: 2728 2729 baudrate - see CONFIG_BAUDRATE 2730 2731 bootdelay - see CONFIG_BOOTDELAY 2732 2733 bootcmd - see CONFIG_BOOTCOMMAND 2734 2735 bootargs - Boot arguments when booting an RTOS image 2736 2737 bootfile - Name of the image to load with TFTP 2738 2739 autoload - if set to "no" (any string beginning with 'n'), 2740 "bootp" will just load perform a lookup of the 2741 configuration from the BOOTP server, but not try to 2742 load any image using TFTP 2743 2744 autoscript - if set to "yes" commands like "loadb", "loady", 2745 "bootp", "tftpb", "rarpboot" and "nfs" will attempt 2746 to automatically run script images (by internally 2747 calling "autoscript"). 2748 2749 autoscript_uname - if script image is in a format (FIT) this 2750 variable is used to get script subimage unit name. 2751 2752 autostart - if set to "yes", an image loaded using the "bootp", 2753 "rarpboot", "tftpboot" or "diskboot" commands will 2754 be automatically started (by internally calling 2755 "bootm") 2756 2757 If set to "no", a standalone image passed to the 2758 "bootm" command will be copied to the load address 2759 (and eventually uncompressed), but NOT be started. 2760 This can be used to load and uncompress arbitrary 2761 data. 2762 2763 i2cfast - (PPC405GP|PPC405EP only) 2764 if set to 'y' configures Linux I2C driver for fast 2765 mode (400kHZ). This environment variable is used in 2766 initialization code. So, for changes to be effective 2767 it must be saved and board must be reset. 2768 2769 initrd_high - restrict positioning of initrd images: 2770 If this variable is not set, initrd images will be 2771 copied to the highest possible address in RAM; this 2772 is usually what you want since it allows for 2773 maximum initrd size. If for some reason you want to 2774 make sure that the initrd image is loaded below the 2775 CFG_BOOTMAPSZ limit, you can set this environment 2776 variable to a value of "no" or "off" or "0". 2777 Alternatively, you can set it to a maximum upper 2778 address to use (U-Boot will still check that it 2779 does not overwrite the U-Boot stack and data). 2780 2781 For instance, when you have a system with 16 MB 2782 RAM, and want to reserve 4 MB from use by Linux, 2783 you can do this by adding "mem=12M" to the value of 2784 the "bootargs" variable. However, now you must make 2785 sure that the initrd image is placed in the first 2786 12 MB as well - this can be done with 2787 2788 setenv initrd_high 00c00000 2789 2790 If you set initrd_high to 0xFFFFFFFF, this is an 2791 indication to U-Boot that all addresses are legal 2792 for the Linux kernel, including addresses in flash 2793 memory. In this case U-Boot will NOT COPY the 2794 ramdisk at all. This may be useful to reduce the 2795 boot time on your system, but requires that this 2796 feature is supported by your Linux kernel. 2797 2798 ipaddr - IP address; needed for tftpboot command 2799 2800 loadaddr - Default load address for commands like "bootp", 2801 "rarpboot", "tftpboot", "loadb" or "diskboot" 2802 2803 loads_echo - see CONFIG_LOADS_ECHO 2804 2805 serverip - TFTP server IP address; needed for tftpboot command 2806 2807 bootretry - see CONFIG_BOOT_RETRY_TIME 2808 2809 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 2810 2811 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 2812 2813 ethprime - When CONFIG_NET_MULTI is enabled controls which 2814 interface is used first. 2815 2816 ethact - When CONFIG_NET_MULTI is enabled controls which 2817 interface is currently active. For example you 2818 can do the following 2819 2820 => setenv ethact FEC ETHERNET 2821 => ping 192.168.0.1 # traffic sent on FEC ETHERNET 2822 => setenv ethact SCC ETHERNET 2823 => ping 10.0.0.1 # traffic sent on SCC ETHERNET 2824 2825 ethrotate - When set to "no" U-Boot does not go through all 2826 available network interfaces. 2827 It just stays at the currently selected interface. 2828 2829 netretry - When set to "no" each network operation will 2830 either succeed or fail without retrying. 2831 When set to "once" the network operation will 2832 fail when all the available network interfaces 2833 are tried once without success. 2834 Useful on scripts which control the retry operation 2835 themselves. 2836 2837 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD 2838 if set load address for the npe microcode 2839 2840 tftpsrcport - If this is set, the value is used for TFTP's 2841 UDP source port. 2842 2843 tftpdstport - If this is set, the value is used for TFTP's UDP 2844 destination port instead of the Well Know Port 69. 2845 2846 vlan - When set to a value < 4095 the traffic over 2847 ethernet is encapsulated/received over 802.1q 2848 VLAN tagged frames. 2849 2850The following environment variables may be used and automatically 2851updated by the network boot commands ("bootp" and "rarpboot"), 2852depending the information provided by your boot server: 2853 2854 bootfile - see above 2855 dnsip - IP address of your Domain Name Server 2856 dnsip2 - IP address of your secondary Domain Name Server 2857 gatewayip - IP address of the Gateway (Router) to use 2858 hostname - Target hostname 2859 ipaddr - see above 2860 netmask - Subnet Mask 2861 rootpath - Pathname of the root filesystem on the NFS server 2862 serverip - see above 2863 2864 2865There are two special Environment Variables: 2866 2867 serial# - contains hardware identification information such 2868 as type string and/or serial number 2869 ethaddr - Ethernet address 2870 2871These variables can be set only once (usually during manufacturing of 2872the board). U-Boot refuses to delete or overwrite these variables 2873once they have been set once. 2874 2875 2876Further special Environment Variables: 2877 2878 ver - Contains the U-Boot version string as printed 2879 with the "version" command. This variable is 2880 readonly (see CONFIG_VERSION_VARIABLE). 2881 2882 2883Please note that changes to some configuration parameters may take 2884only effect after the next boot (yes, that's just like Windoze :-). 2885 2886 2887Command Line Parsing: 2888===================== 2889 2890There are two different command line parsers available with U-Boot: 2891the old "simple" one, and the much more powerful "hush" shell: 2892 2893Old, simple command line parser: 2894-------------------------------- 2895 2896- supports environment variables (through setenv / saveenv commands) 2897- several commands on one line, separated by ';' 2898- variable substitution using "... ${name} ..." syntax 2899- special characters ('$', ';') can be escaped by prefixing with '\', 2900 for example: 2901 setenv bootcmd bootm \${address} 2902- You can also escape text by enclosing in single apostrophes, for example: 2903 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 2904 2905Hush shell: 2906----------- 2907 2908- similar to Bourne shell, with control structures like 2909 if...then...else...fi, for...do...done; while...do...done, 2910 until...do...done, ... 2911- supports environment ("global") variables (through setenv / saveenv 2912 commands) and local shell variables (through standard shell syntax 2913 "name=value"); only environment variables can be used with "run" 2914 command 2915 2916General rules: 2917-------------- 2918 2919(1) If a command line (or an environment variable executed by a "run" 2920 command) contains several commands separated by semicolon, and 2921 one of these commands fails, then the remaining commands will be 2922 executed anyway. 2923 2924(2) If you execute several variables with one call to run (i. e. 2925 calling run with a list af variables as arguments), any failing 2926 command will cause "run" to terminate, i. e. the remaining 2927 variables are not executed. 2928 2929Note for Redundant Ethernet Interfaces: 2930======================================= 2931 2932Some boards come with redundant ethernet interfaces; U-Boot supports 2933such configurations and is capable of automatic selection of a 2934"working" interface when needed. MAC assignment works as follows: 2935 2936Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 2937MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 2938"eth1addr" (=>eth1), "eth2addr", ... 2939 2940If the network interface stores some valid MAC address (for instance 2941in SROM), this is used as default address if there is NO correspon- 2942ding setting in the environment; if the corresponding environment 2943variable is set, this overrides the settings in the card; that means: 2944 2945o If the SROM has a valid MAC address, and there is no address in the 2946 environment, the SROM's address is used. 2947 2948o If there is no valid address in the SROM, and a definition in the 2949 environment exists, then the value from the environment variable is 2950 used. 2951 2952o If both the SROM and the environment contain a MAC address, and 2953 both addresses are the same, this MAC address is used. 2954 2955o If both the SROM and the environment contain a MAC address, and the 2956 addresses differ, the value from the environment is used and a 2957 warning is printed. 2958 2959o If neither SROM nor the environment contain a MAC address, an error 2960 is raised. 2961 2962 2963Image Formats: 2964============== 2965 2966U-Boot is capable of booting (and performing other auxiliary operations on) 2967images in two formats: 2968 2969New uImage format (FIT) 2970----------------------- 2971 2972Flexible and powerful format based on Flattened Image Tree -- FIT (similar 2973to Flattened Device Tree). It allows the use of images with multiple 2974components (several kernels, ramdisks, etc.), with contents protected by 2975SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 2976 2977 2978Old uImage format 2979----------------- 2980 2981Old image format is based on binary files which can be basically anything, 2982preceded by a special header; see the definitions in include/image.h for 2983details; basically, the header defines the following image properties: 2984 2985* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 2986 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 2987 LynxOS, pSOS, QNX, RTEMS, ARTOS; 2988 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS). 2989* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 2990 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 2991 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC). 2992* Compression Type (uncompressed, gzip, bzip2) 2993* Load Address 2994* Entry Point 2995* Image Name 2996* Image Timestamp 2997 2998The header is marked by a special Magic Number, and both the header 2999and the data portions of the image are secured against corruption by 3000CRC32 checksums. 3001 3002 3003Linux Support: 3004============== 3005 3006Although U-Boot should support any OS or standalone application 3007easily, the main focus has always been on Linux during the design of 3008U-Boot. 3009 3010U-Boot includes many features that so far have been part of some 3011special "boot loader" code within the Linux kernel. Also, any 3012"initrd" images to be used are no longer part of one big Linux image; 3013instead, kernel and "initrd" are separate images. This implementation 3014serves several purposes: 3015 3016- the same features can be used for other OS or standalone 3017 applications (for instance: using compressed images to reduce the 3018 Flash memory footprint) 3019 3020- it becomes much easier to port new Linux kernel versions because 3021 lots of low-level, hardware dependent stuff are done by U-Boot 3022 3023- the same Linux kernel image can now be used with different "initrd" 3024 images; of course this also means that different kernel images can 3025 be run with the same "initrd". This makes testing easier (you don't 3026 have to build a new "zImage.initrd" Linux image when you just 3027 change a file in your "initrd"). Also, a field-upgrade of the 3028 software is easier now. 3029 3030 3031Linux HOWTO: 3032============ 3033 3034Porting Linux to U-Boot based systems: 3035--------------------------------------- 3036 3037U-Boot cannot save you from doing all the necessary modifications to 3038configure the Linux device drivers for use with your target hardware 3039(no, we don't intend to provide a full virtual machine interface to 3040Linux :-). 3041 3042But now you can ignore ALL boot loader code (in arch/ppc/mbxboot). 3043 3044Just make sure your machine specific header file (for instance 3045include/asm-ppc/tqm8xx.h) includes the same definition of the Board 3046Information structure as we define in include/u-boot.h, and make 3047sure that your definition of IMAP_ADDR uses the same value as your 3048U-Boot configuration in CFG_IMMR. 3049 3050 3051Configuring the Linux kernel: 3052----------------------------- 3053 3054No specific requirements for U-Boot. Make sure you have some root 3055device (initial ramdisk, NFS) for your target system. 3056 3057 3058Building a Linux Image: 3059----------------------- 3060 3061With U-Boot, "normal" build targets like "zImage" or "bzImage" are 3062not used. If you use recent kernel source, a new build target 3063"uImage" will exist which automatically builds an image usable by 3064U-Boot. Most older kernels also have support for a "pImage" target, 3065which was introduced for our predecessor project PPCBoot and uses a 3066100% compatible format. 3067 3068Example: 3069 3070 make TQM850L_config 3071 make oldconfig 3072 make dep 3073 make uImage 3074 3075The "uImage" build target uses a special tool (in 'tools/mkimage') to 3076encapsulate a compressed Linux kernel image with header information, 3077CRC32 checksum etc. for use with U-Boot. This is what we are doing: 3078 3079* build a standard "vmlinux" kernel image (in ELF binary format): 3080 3081* convert the kernel into a raw binary image: 3082 3083 ${CROSS_COMPILE}-objcopy -O binary \ 3084 -R .note -R .comment \ 3085 -S vmlinux linux.bin 3086 3087* compress the binary image: 3088 3089 gzip -9 linux.bin 3090 3091* package compressed binary image for U-Boot: 3092 3093 mkimage -A ppc -O linux -T kernel -C gzip \ 3094 -a 0 -e 0 -n "Linux Kernel Image" \ 3095 -d linux.bin.gz uImage 3096 3097 3098The "mkimage" tool can also be used to create ramdisk images for use 3099with U-Boot, either separated from the Linux kernel image, or 3100combined into one file. "mkimage" encapsulates the images with a 64 3101byte header containing information about target architecture, 3102operating system, image type, compression method, entry points, time 3103stamp, CRC32 checksums, etc. 3104 3105"mkimage" can be called in two ways: to verify existing images and 3106print the header information, or to build new images. 3107 3108In the first form (with "-l" option) mkimage lists the information 3109contained in the header of an existing U-Boot image; this includes 3110checksum verification: 3111 3112 tools/mkimage -l image 3113 -l ==> list image header information 3114 3115The second form (with "-d" option) is used to build a U-Boot image 3116from a "data file" which is used as image payload: 3117 3118 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 3119 -n name -d data_file image 3120 -A ==> set architecture to 'arch' 3121 -O ==> set operating system to 'os' 3122 -T ==> set image type to 'type' 3123 -C ==> set compression type 'comp' 3124 -a ==> set load address to 'addr' (hex) 3125 -e ==> set entry point to 'ep' (hex) 3126 -n ==> set image name to 'name' 3127 -d ==> use image data from 'datafile' 3128 3129Right now, all Linux kernels for PowerPC systems use the same load 3130address (0x00000000), but the entry point address depends on the 3131kernel version: 3132 3133- 2.2.x kernels have the entry point at 0x0000000C, 3134- 2.3.x and later kernels have the entry point at 0x00000000. 3135 3136So a typical call to build a U-Boot image would read: 3137 3138 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3139 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 3140 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \ 3141 > examples/uImage.TQM850L 3142 Image Name: 2.4.4 kernel for TQM850L 3143 Created: Wed Jul 19 02:34:59 2000 3144 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3145 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3146 Load Address: 0x00000000 3147 Entry Point: 0x00000000 3148 3149To verify the contents of the image (or check for corruption): 3150 3151 -> tools/mkimage -l examples/uImage.TQM850L 3152 Image Name: 2.4.4 kernel for TQM850L 3153 Created: Wed Jul 19 02:34:59 2000 3154 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3155 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 3156 Load Address: 0x00000000 3157 Entry Point: 0x00000000 3158 3159NOTE: for embedded systems where boot time is critical you can trade 3160speed for memory and install an UNCOMPRESSED image instead: this 3161needs more space in Flash, but boots much faster since it does not 3162need to be uncompressed: 3163 3164 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz 3165 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 3166 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 3167 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \ 3168 > examples/uImage.TQM850L-uncompressed 3169 Image Name: 2.4.4 kernel for TQM850L 3170 Created: Wed Jul 19 02:34:59 2000 3171 Image Type: PowerPC Linux Kernel Image (uncompressed) 3172 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 3173 Load Address: 0x00000000 3174 Entry Point: 0x00000000 3175 3176 3177Similar you can build U-Boot images from a 'ramdisk.image.gz' file 3178when your kernel is intended to use an initial ramdisk: 3179 3180 -> tools/mkimage -n 'Simple Ramdisk Image' \ 3181 > -A ppc -O linux -T ramdisk -C gzip \ 3182 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 3183 Image Name: Simple Ramdisk Image 3184 Created: Wed Jan 12 14:01:50 2000 3185 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3186 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 3187 Load Address: 0x00000000 3188 Entry Point: 0x00000000 3189 3190 3191Installing a Linux Image: 3192------------------------- 3193 3194To downloading a U-Boot image over the serial (console) interface, 3195you must convert the image to S-Record format: 3196 3197 objcopy -I binary -O srec examples/image examples/image.srec 3198 3199The 'objcopy' does not understand the information in the U-Boot 3200image header, so the resulting S-Record file will be relative to 3201address 0x00000000. To load it to a given address, you need to 3202specify the target address as 'offset' parameter with the 'loads' 3203command. 3204 3205Example: install the image to address 0x40100000 (which on the 3206TQM8xxL is in the first Flash bank): 3207 3208 => erase 40100000 401FFFFF 3209 3210 .......... done 3211 Erased 8 sectors 3212 3213 => loads 40100000 3214 ## Ready for S-Record download ... 3215 ~>examples/image.srec 3216 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 3217 ... 3218 15989 15990 15991 15992 3219 [file transfer complete] 3220 [connected] 3221 ## Start Addr = 0x00000000 3222 3223 3224You can check the success of the download using the 'iminfo' command; 3225this includes a checksum verification so you can be sure no data 3226corruption happened: 3227 3228 => imi 40100000 3229 3230 ## Checking Image at 40100000 ... 3231 Image Name: 2.2.13 for initrd on TQM850L 3232 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3233 Data Size: 335725 Bytes = 327 kB = 0 MB 3234 Load Address: 00000000 3235 Entry Point: 0000000c 3236 Verifying Checksum ... OK 3237 3238 3239Boot Linux: 3240----------- 3241 3242The "bootm" command is used to boot an application that is stored in 3243memory (RAM or Flash). In case of a Linux kernel image, the contents 3244of the "bootargs" environment variable is passed to the kernel as 3245parameters. You can check and modify this variable using the 3246"printenv" and "setenv" commands: 3247 3248 3249 => printenv bootargs 3250 bootargs=root=/dev/ram 3251 3252 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3253 3254 => printenv bootargs 3255 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3256 3257 => bootm 40020000 3258 ## Booting Linux kernel at 40020000 ... 3259 Image Name: 2.2.13 for NFS on TQM850L 3260 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3261 Data Size: 381681 Bytes = 372 kB = 0 MB 3262 Load Address: 00000000 3263 Entry Point: 0000000c 3264 Verifying Checksum ... OK 3265 Uncompressing Kernel Image ... OK 3266 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 3267 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 3268 time_init: decrementer frequency = 187500000/60 3269 Calibrating delay loop... 49.77 BogoMIPS 3270 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 3271 ... 3272 3273If you want to boot a Linux kernel with initial ram disk, you pass 3274the memory addresses of both the kernel and the initrd image (PPBCOOT 3275format!) to the "bootm" command: 3276 3277 => imi 40100000 40200000 3278 3279 ## Checking Image at 40100000 ... 3280 Image Name: 2.2.13 for initrd on TQM850L 3281 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3282 Data Size: 335725 Bytes = 327 kB = 0 MB 3283 Load Address: 00000000 3284 Entry Point: 0000000c 3285 Verifying Checksum ... OK 3286 3287 ## Checking Image at 40200000 ... 3288 Image Name: Simple Ramdisk Image 3289 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3290 Data Size: 566530 Bytes = 553 kB = 0 MB 3291 Load Address: 00000000 3292 Entry Point: 00000000 3293 Verifying Checksum ... OK 3294 3295 => bootm 40100000 40200000 3296 ## Booting Linux kernel at 40100000 ... 3297 Image Name: 2.2.13 for initrd on TQM850L 3298 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3299 Data Size: 335725 Bytes = 327 kB = 0 MB 3300 Load Address: 00000000 3301 Entry Point: 0000000c 3302 Verifying Checksum ... OK 3303 Uncompressing Kernel Image ... OK 3304 ## Loading RAMDisk Image at 40200000 ... 3305 Image Name: Simple Ramdisk Image 3306 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 3307 Data Size: 566530 Bytes = 553 kB = 0 MB 3308 Load Address: 00000000 3309 Entry Point: 00000000 3310 Verifying Checksum ... OK 3311 Loading Ramdisk ... OK 3312 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 3313 Boot arguments: root=/dev/ram 3314 time_init: decrementer frequency = 187500000/60 3315 Calibrating delay loop... 49.77 BogoMIPS 3316 ... 3317 RAMDISK: Compressed image found at block 0 3318 VFS: Mounted root (ext2 filesystem). 3319 3320 bash# 3321 3322Boot Linux and pass a flat device tree: 3323----------- 3324 3325First, U-Boot must be compiled with the appropriate defines. See the section 3326titled "Linux Kernel Interface" above for a more in depth explanation. The 3327following is an example of how to start a kernel and pass an updated 3328flat device tree: 3329 3330=> print oftaddr 3331oftaddr=0x300000 3332=> print oft 3333oft=oftrees/mpc8540ads.dtb 3334=> tftp $oftaddr $oft 3335Speed: 1000, full duplex 3336Using TSEC0 device 3337TFTP from server 192.168.1.1; our IP address is 192.168.1.101 3338Filename 'oftrees/mpc8540ads.dtb'. 3339Load address: 0x300000 3340Loading: # 3341done 3342Bytes transferred = 4106 (100a hex) 3343=> tftp $loadaddr $bootfile 3344Speed: 1000, full duplex 3345Using TSEC0 device 3346TFTP from server 192.168.1.1; our IP address is 192.168.1.2 3347Filename 'uImage'. 3348Load address: 0x200000 3349Loading:############ 3350done 3351Bytes transferred = 1029407 (fb51f hex) 3352=> print loadaddr 3353loadaddr=200000 3354=> print oftaddr 3355oftaddr=0x300000 3356=> bootm $loadaddr - $oftaddr 3357## Booting image at 00200000 ... 3358 Image Name: Linux-2.6.17-dirty 3359 Image Type: PowerPC Linux Kernel Image (gzip compressed) 3360 Data Size: 1029343 Bytes = 1005.2 kB 3361 Load Address: 00000000 3362 Entry Point: 00000000 3363 Verifying Checksum ... OK 3364 Uncompressing Kernel Image ... OK 3365Booting using flat device tree at 0x300000 3366Using MPC85xx ADS machine description 3367Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 3368[snip] 3369 3370 3371More About U-Boot Image Types: 3372------------------------------ 3373 3374U-Boot supports the following image types: 3375 3376 "Standalone Programs" are directly runnable in the environment 3377 provided by U-Boot; it is expected that (if they behave 3378 well) you can continue to work in U-Boot after return from 3379 the Standalone Program. 3380 "OS Kernel Images" are usually images of some Embedded OS which 3381 will take over control completely. Usually these programs 3382 will install their own set of exception handlers, device 3383 drivers, set up the MMU, etc. - this means, that you cannot 3384 expect to re-enter U-Boot except by resetting the CPU. 3385 "RAMDisk Images" are more or less just data blocks, and their 3386 parameters (address, size) are passed to an OS kernel that is 3387 being started. 3388 "Multi-File Images" contain several images, typically an OS 3389 (Linux) kernel image and one or more data images like 3390 RAMDisks. This construct is useful for instance when you want 3391 to boot over the network using BOOTP etc., where the boot 3392 server provides just a single image file, but you want to get 3393 for instance an OS kernel and a RAMDisk image. 3394 3395 "Multi-File Images" start with a list of image sizes, each 3396 image size (in bytes) specified by an "uint32_t" in network 3397 byte order. This list is terminated by an "(uint32_t)0". 3398 Immediately after the terminating 0 follow the images, one by 3399 one, all aligned on "uint32_t" boundaries (size rounded up to 3400 a multiple of 4 bytes). 3401 3402 "Firmware Images" are binary images containing firmware (like 3403 U-Boot or FPGA images) which usually will be programmed to 3404 flash memory. 3405 3406 "Script files" are command sequences that will be executed by 3407 U-Boot's command interpreter; this feature is especially 3408 useful when you configure U-Boot to use a real shell (hush) 3409 as command interpreter. 3410 3411 3412Standalone HOWTO: 3413================= 3414 3415One of the features of U-Boot is that you can dynamically load and 3416run "standalone" applications, which can use some resources of 3417U-Boot like console I/O functions or interrupt services. 3418 3419Two simple examples are included with the sources: 3420 3421"Hello World" Demo: 3422------------------- 3423 3424'examples/hello_world.c' contains a small "Hello World" Demo 3425application; it is automatically compiled when you build U-Boot. 3426It's configured to run at address 0x00040004, so you can play with it 3427like that: 3428 3429 => loads 3430 ## Ready for S-Record download ... 3431 ~>examples/hello_world.srec 3432 1 2 3 4 5 6 7 8 9 10 11 ... 3433 [file transfer complete] 3434 [connected] 3435 ## Start Addr = 0x00040004 3436 3437 => go 40004 Hello World! This is a test. 3438 ## Starting application at 0x00040004 ... 3439 Hello World 3440 argc = 7 3441 argv[0] = "40004" 3442 argv[1] = "Hello" 3443 argv[2] = "World!" 3444 argv[3] = "This" 3445 argv[4] = "is" 3446 argv[5] = "a" 3447 argv[6] = "test." 3448 argv[7] = "<NULL>" 3449 Hit any key to exit ... 3450 3451 ## Application terminated, rc = 0x0 3452 3453Another example, which demonstrates how to register a CPM interrupt 3454handler with the U-Boot code, can be found in 'examples/timer.c'. 3455Here, a CPM timer is set up to generate an interrupt every second. 3456The interrupt service routine is trivial, just printing a '.' 3457character, but this is just a demo program. The application can be 3458controlled by the following keys: 3459 3460 ? - print current values og the CPM Timer registers 3461 b - enable interrupts and start timer 3462 e - stop timer and disable interrupts 3463 q - quit application 3464 3465 => loads 3466 ## Ready for S-Record download ... 3467 ~>examples/timer.srec 3468 1 2 3 4 5 6 7 8 9 10 11 ... 3469 [file transfer complete] 3470 [connected] 3471 ## Start Addr = 0x00040004 3472 3473 => go 40004 3474 ## Starting application at 0x00040004 ... 3475 TIMERS=0xfff00980 3476 Using timer 1 3477 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 3478 3479Hit 'b': 3480 [q, b, e, ?] Set interval 1000000 us 3481 Enabling timer 3482Hit '?': 3483 [q, b, e, ?] ........ 3484 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 3485Hit '?': 3486 [q, b, e, ?] . 3487 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 3488Hit '?': 3489 [q, b, e, ?] . 3490 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 3491Hit '?': 3492 [q, b, e, ?] . 3493 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 3494Hit 'e': 3495 [q, b, e, ?] ...Stopping timer 3496Hit 'q': 3497 [q, b, e, ?] ## Application terminated, rc = 0x0 3498 3499 3500Minicom warning: 3501================ 3502 3503Over time, many people have reported problems when trying to use the 3504"minicom" terminal emulation program for serial download. I (wd) 3505consider minicom to be broken, and recommend not to use it. Under 3506Unix, I recommend to use C-Kermit for general purpose use (and 3507especially for kermit binary protocol download ("loadb" command), and 3508use "cu" for S-Record download ("loads" command). 3509 3510Nevertheless, if you absolutely want to use it try adding this 3511configuration to your "File transfer protocols" section: 3512 3513 Name Program Name U/D FullScr IO-Red. Multi 3514 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 3515 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 3516 3517 3518NetBSD Notes: 3519============= 3520 3521Starting at version 0.9.2, U-Boot supports NetBSD both as host 3522(build U-Boot) and target system (boots NetBSD/mpc8xx). 3523 3524Building requires a cross environment; it is known to work on 3525NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 3526need gmake since the Makefiles are not compatible with BSD make). 3527Note that the cross-powerpc package does not install include files; 3528attempting to build U-Boot will fail because <machine/ansi.h> is 3529missing. This file has to be installed and patched manually: 3530 3531 # cd /usr/pkg/cross/powerpc-netbsd/include 3532 # mkdir powerpc 3533 # ln -s powerpc machine 3534 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 3535 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 3536 3537Native builds *don't* work due to incompatibilities between native 3538and U-Boot include files. 3539 3540Booting assumes that (the first part of) the image booted is a 3541stage-2 loader which in turn loads and then invokes the kernel 3542proper. Loader sources will eventually appear in the NetBSD source 3543tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 3544meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 3545 3546 3547Implementation Internals: 3548========================= 3549 3550The following is not intended to be a complete description of every 3551implementation detail. However, it should help to understand the 3552inner workings of U-Boot and make it easier to port it to custom 3553hardware. 3554 3555 3556Initial Stack, Global Data: 3557--------------------------- 3558 3559The implementation of U-Boot is complicated by the fact that U-Boot 3560starts running out of ROM (flash memory), usually without access to 3561system RAM (because the memory controller is not initialized yet). 3562This means that we don't have writable Data or BSS segments, and BSS 3563is not initialized as zero. To be able to get a C environment working 3564at all, we have to allocate at least a minimal stack. Implementation 3565options for this are defined and restricted by the CPU used: Some CPU 3566models provide on-chip memory (like the IMMR area on MPC8xx and 3567MPC826x processors), on others (parts of) the data cache can be 3568locked as (mis-) used as memory, etc. 3569 3570 Chris Hallinan posted a good summary of these issues to the 3571 u-boot-users mailing list: 3572 3573 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 3574 From: "Chris Hallinan" <clh@net1plus.com> 3575 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 3576 ... 3577 3578 Correct me if I'm wrong, folks, but the way I understand it 3579 is this: Using DCACHE as initial RAM for Stack, etc, does not 3580 require any physical RAM backing up the cache. The cleverness 3581 is that the cache is being used as a temporary supply of 3582 necessary storage before the SDRAM controller is setup. It's 3583 beyond the scope of this list to expain the details, but you 3584 can see how this works by studying the cache architecture and 3585 operation in the architecture and processor-specific manuals. 3586 3587 OCM is On Chip Memory, which I believe the 405GP has 4K. It 3588 is another option for the system designer to use as an 3589 initial stack/ram area prior to SDRAM being available. Either 3590 option should work for you. Using CS 4 should be fine if your 3591 board designers haven't used it for something that would 3592 cause you grief during the initial boot! It is frequently not 3593 used. 3594 3595 CFG_INIT_RAM_ADDR should be somewhere that won't interfere 3596 with your processor/board/system design. The default value 3597 you will find in any recent u-boot distribution in 3598 walnut.h should work for you. I'd set it to a value larger 3599 than your SDRAM module. If you have a 64MB SDRAM module, set 3600 it above 400_0000. Just make sure your board has no resources 3601 that are supposed to respond to that address! That code in 3602 start.S has been around a while and should work as is when 3603 you get the config right. 3604 3605 -Chris Hallinan 3606 DS4.COM, Inc. 3607 3608It is essential to remember this, since it has some impact on the C 3609code for the initialization procedures: 3610 3611* Initialized global data (data segment) is read-only. Do not attempt 3612 to write it. 3613 3614* Do not use any unitialized global data (or implicitely initialized 3615 as zero data - BSS segment) at all - this is undefined, initiali- 3616 zation is performed later (when relocating to RAM). 3617 3618* Stack space is very limited. Avoid big data buffers or things like 3619 that. 3620 3621Having only the stack as writable memory limits means we cannot use 3622normal global data to share information beween the code. But it 3623turned out that the implementation of U-Boot can be greatly 3624simplified by making a global data structure (gd_t) available to all 3625functions. We could pass a pointer to this data as argument to _all_ 3626functions, but this would bloat the code. Instead we use a feature of 3627the GCC compiler (Global Register Variables) to share the data: we 3628place a pointer (gd) to the global data into a register which we 3629reserve for this purpose. 3630 3631When choosing a register for such a purpose we are restricted by the 3632relevant (E)ABI specifications for the current architecture, and by 3633GCC's implementation. 3634 3635For PowerPC, the following registers have specific use: 3636 R1: stack pointer 3637 R2: reserved for system use 3638 R3-R4: parameter passing and return values 3639 R5-R10: parameter passing 3640 R13: small data area pointer 3641 R30: GOT pointer 3642 R31: frame pointer 3643 3644 (U-Boot also uses R14 as internal GOT pointer.) 3645 3646 ==> U-Boot will use R2 to hold a pointer to the global data 3647 3648 Note: on PPC, we could use a static initializer (since the 3649 address of the global data structure is known at compile time), 3650 but it turned out that reserving a register results in somewhat 3651 smaller code - although the code savings are not that big (on 3652 average for all boards 752 bytes for the whole U-Boot image, 3653 624 text + 127 data). 3654 3655On Blackfin, the normal C ABI (except for P5) is followed as documented here: 3656 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 3657 3658 ==> U-Boot will use P5 to hold a pointer to the global data 3659 3660On ARM, the following registers are used: 3661 3662 R0: function argument word/integer result 3663 R1-R3: function argument word 3664 R9: GOT pointer 3665 R10: stack limit (used only if stack checking if enabled) 3666 R11: argument (frame) pointer 3667 R12: temporary workspace 3668 R13: stack pointer 3669 R14: link register 3670 R15: program counter 3671 3672 ==> U-Boot will use R8 to hold a pointer to the global data 3673 3674NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 3675or current versions of GCC may "optimize" the code too much. 3676 3677Memory Management: 3678------------------ 3679 3680U-Boot runs in system state and uses physical addresses, i.e. the 3681MMU is not used either for address mapping nor for memory protection. 3682 3683The available memory is mapped to fixed addresses using the memory 3684controller. In this process, a contiguous block is formed for each 3685memory type (Flash, SDRAM, SRAM), even when it consists of several 3686physical memory banks. 3687 3688U-Boot is installed in the first 128 kB of the first Flash bank (on 3689TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 3690booting and sizing and initializing DRAM, the code relocates itself 3691to the upper end of DRAM. Immediately below the U-Boot code some 3692memory is reserved for use by malloc() [see CFG_MALLOC_LEN 3693configuration setting]. Below that, a structure with global Board 3694Info data is placed, followed by the stack (growing downward). 3695 3696Additionally, some exception handler code is copied to the low 8 kB 3697of DRAM (0x00000000 ... 0x00001FFF). 3698 3699So a typical memory configuration with 16 MB of DRAM could look like 3700this: 3701 3702 0x0000 0000 Exception Vector code 3703 : 3704 0x0000 1FFF 3705 0x0000 2000 Free for Application Use 3706 : 3707 : 3708 3709 : 3710 : 3711 0x00FB FF20 Monitor Stack (Growing downward) 3712 0x00FB FFAC Board Info Data and permanent copy of global data 3713 0x00FC 0000 Malloc Arena 3714 : 3715 0x00FD FFFF 3716 0x00FE 0000 RAM Copy of Monitor Code 3717 ... eventually: LCD or video framebuffer 3718 ... eventually: pRAM (Protected RAM - unchanged by reset) 3719 0x00FF FFFF [End of RAM] 3720 3721 3722System Initialization: 3723---------------------- 3724 3725In the reset configuration, U-Boot starts at the reset entry point 3726(on most PowerPC systens at address 0x00000100). Because of the reset 3727configuration for CS0# this is a mirror of the onboard Flash memory. 3728To be able to re-map memory U-Boot then jumps to its link address. 3729To be able to implement the initialization code in C, a (small!) 3730initial stack is set up in the internal Dual Ported RAM (in case CPUs 3731which provide such a feature like MPC8xx or MPC8260), or in a locked 3732part of the data cache. After that, U-Boot initializes the CPU core, 3733the caches and the SIU. 3734 3735Next, all (potentially) available memory banks are mapped using a 3736preliminary mapping. For example, we put them on 512 MB boundaries 3737(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 3738on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 3739programmed for SDRAM access. Using the temporary configuration, a 3740simple memory test is run that determines the size of the SDRAM 3741banks. 3742 3743When there is more than one SDRAM bank, and the banks are of 3744different size, the largest is mapped first. For equal size, the first 3745bank (CS2#) is mapped first. The first mapping is always for address 37460x00000000, with any additional banks following immediately to create 3747contiguous memory starting from 0. 3748 3749Then, the monitor installs itself at the upper end of the SDRAM area 3750and allocates memory for use by malloc() and for the global Board 3751Info data; also, the exception vector code is copied to the low RAM 3752pages, and the final stack is set up. 3753 3754Only after this relocation will you have a "normal" C environment; 3755until that you are restricted in several ways, mostly because you are 3756running from ROM, and because the code will have to be relocated to a 3757new address in RAM. 3758 3759 3760U-Boot Porting Guide: 3761---------------------- 3762 3763[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 3764list, October 2002] 3765 3766 3767int main (int argc, char *argv[]) 3768{ 3769 sighandler_t no_more_time; 3770 3771 signal (SIGALRM, no_more_time); 3772 alarm (PROJECT_DEADLINE - toSec (3 * WEEK)); 3773 3774 if (available_money > available_manpower) { 3775 pay consultant to port U-Boot; 3776 return 0; 3777 } 3778 3779 Download latest U-Boot source; 3780 3781 Subscribe to u-boot-users mailing list; 3782 3783 if (clueless) { 3784 email ("Hi, I am new to U-Boot, how do I get started?"); 3785 } 3786 3787 while (learning) { 3788 Read the README file in the top level directory; 3789 Read http://www.denx.de/twiki/bin/view/DULG/Manual ; 3790 Read the source, Luke; 3791 } 3792 3793 if (available_money > toLocalCurrency ($2500)) { 3794 Buy a BDI2000; 3795 } else { 3796 Add a lot of aggravation and time; 3797 } 3798 3799 Create your own board support subdirectory; 3800 3801 Create your own board config file; 3802 3803 while (!running) { 3804 do { 3805 Add / modify source code; 3806 } until (compiles); 3807 Debug; 3808 if (clueless) 3809 email ("Hi, I am having problems..."); 3810 } 3811 Send patch file to Wolfgang; 3812 3813 return 0; 3814} 3815 3816void no_more_time (int sig) 3817{ 3818 hire_a_guru(); 3819} 3820 3821 3822Coding Standards: 3823----------------- 3824 3825All contributions to U-Boot should conform to the Linux kernel 3826coding style; see the file "Documentation/CodingStyle" and the script 3827"scripts/Lindent" in your Linux kernel source directory. In sources 3828originating from U-Boot a style corresponding to "Lindent -pcs" (adding 3829spaces before parameters to function calls) is actually used. 3830 3831Source files originating from a different project (for example the 3832MTD subsystem) are generally exempt from these guidelines and are not 3833reformated to ease subsequent migration to newer versions of those 3834sources. 3835 3836Please note that U-Boot is implemented in C (and to some small parts in 3837Assembler); no C++ is used, so please do not use C++ style comments (//) 3838in your code. 3839 3840Please also stick to the following formatting rules: 3841- remove any trailing white space 3842- use TAB characters for indentation, not spaces 3843- make sure NOT to use DOS '\r\n' line feeds 3844- do not add more than 2 empty lines to source files 3845- do not add trailing empty lines to source files 3846 3847Submissions which do not conform to the standards may be returned 3848with a request to reformat the changes. 3849 3850 3851Submitting Patches: 3852------------------- 3853 3854Since the number of patches for U-Boot is growing, we need to 3855establish some rules. Submissions which do not conform to these rules 3856may be rejected, even when they contain important and valuable stuff. 3857 3858Patches shall be sent to the u-boot-users mailing list. 3859 3860Please see http://www.denx.de/wiki/UBoot/Patches for details. 3861 3862When you send a patch, please include the following information with 3863it: 3864 3865* For bug fixes: a description of the bug and how your patch fixes 3866 this bug. Please try to include a way of demonstrating that the 3867 patch actually fixes something. 3868 3869* For new features: a description of the feature and your 3870 implementation. 3871 3872* A CHANGELOG entry as plaintext (separate from the patch) 3873 3874* For major contributions, your entry to the CREDITS file 3875 3876* When you add support for a new board, don't forget to add this 3877 board to the MAKEALL script, too. 3878 3879* If your patch adds new configuration options, don't forget to 3880 document these in the README file. 3881 3882* The patch itself. If you are using git (which is *strongly* 3883 recommended) you can easily generate the patch using the 3884 "git-format-patch". If you then use "git-send-email" to send it to 3885 the U-Boot mailing list, you will avoid most of the common problems 3886 with some other mail clients. 3887 3888 If you cannot use git, use "diff -purN OLD NEW". If your version of 3889 diff does not support these options, then get the latest version of 3890 GNU diff. 3891 3892 The current directory when running this command shall be the parent 3893 directory of the U-Boot source tree (i. e. please make sure that 3894 your patch includes sufficient directory information for the 3895 affected files). 3896 3897 We prefer patches as plain text. MIME attachments are discouraged, 3898 and compressed attachments must not be used. 3899 3900* If one logical set of modifications affects or creates several 3901 files, all these changes shall be submitted in a SINGLE patch file. 3902 3903* Changesets that contain different, unrelated modifications shall be 3904 submitted as SEPARATE patches, one patch per changeset. 3905 3906 3907Notes: 3908 3909* Before sending the patch, run the MAKEALL script on your patched 3910 source tree and make sure that no errors or warnings are reported 3911 for any of the boards. 3912 3913* Keep your modifications to the necessary minimum: A patch 3914 containing several unrelated changes or arbitrary reformats will be 3915 returned with a request to re-formatting / split it. 3916 3917* If you modify existing code, make sure that your new code does not 3918 add to the memory footprint of the code ;-) Small is beautiful! 3919 When adding new features, these should compile conditionally only 3920 (using #ifdef), and the resulting code with the new feature 3921 disabled must not need more memory than the old code without your 3922 modification. 3923 3924* Remember that there is a size limit of 40 kB per message on the 3925 u-boot-users mailing list. Bigger patches will be moderated. If 3926 they are reasonable and not bigger than 100 kB, they will be 3927 acknowledged. Even bigger patches should be avoided. 3928