1# 2# (C) Copyright 2000 - 2012 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 57Note: There is no CHANGELOG file in the actual U-Boot source tree; 58it can be created dynamically from the Git log using: 59 60 make CHANGELOG 61 62 63Where to get help: 64================== 65 66In case you have questions about, problems with or contributions for 67U-Boot you should send a message to the U-Boot mailing list at 68<u-boot@lists.denx.de>. There is also an archive of previous traffic 69on the mailing list - please search the archive before asking FAQ's. 70Please see http://lists.denx.de/pipermail/u-boot and 71http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 72 73 74Where to get source code: 75========================= 76 77The U-Boot source code is maintained in the git repository at 78git://www.denx.de/git/u-boot.git ; you can browse it online at 79http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 80 81The "snapshot" links on this page allow you to download tarballs of 82any version you might be interested in. Official releases are also 83available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 84directory. 85 86Pre-built (and tested) images are available from 87ftp://ftp.denx.de/pub/u-boot/images/ 88 89 90Where we come from: 91=================== 92 93- start from 8xxrom sources 94- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 95- clean up code 96- make it easier to add custom boards 97- make it possible to add other [PowerPC] CPUs 98- extend functions, especially: 99 * Provide extended interface to Linux boot loader 100 * S-Record download 101 * network boot 102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 103- create ARMBoot project (http://sourceforge.net/projects/armboot) 104- add other CPU families (starting with ARM) 105- create U-Boot project (http://sourceforge.net/projects/u-boot) 106- current project page: see http://www.denx.de/wiki/U-Boot 107 108 109Names and Spelling: 110=================== 111 112The "official" name of this project is "Das U-Boot". The spelling 113"U-Boot" shall be used in all written text (documentation, comments 114in source files etc.). Example: 115 116 This is the README file for the U-Boot project. 117 118File names etc. shall be based on the string "u-boot". Examples: 119 120 include/asm-ppc/u-boot.h 121 122 #include <asm/u-boot.h> 123 124Variable names, preprocessor constants etc. shall be either based on 125the string "u_boot" or on "U_BOOT". Example: 126 127 U_BOOT_VERSION u_boot_logo 128 IH_OS_U_BOOT u_boot_hush_start 129 130 131Versioning: 132=========== 133 134Starting with the release in October 2008, the names of the releases 135were changed from numerical release numbers without deeper meaning 136into a time stamp based numbering. Regular releases are identified by 137names consisting of the calendar year and month of the release date. 138Additional fields (if present) indicate release candidates or bug fix 139releases in "stable" maintenance trees. 140 141Examples: 142 U-Boot v2009.11 - Release November 2009 143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release 145 146 147Directory Hierarchy: 148==================== 149 150/arch Architecture specific files 151 /arm Files generic to ARM architecture 152 /cpu CPU specific files 153 /arm720t Files specific to ARM 720 CPUs 154 /arm920t Files specific to ARM 920 CPUs 155 /at91 Files specific to Atmel AT91RM9200 CPU 156 /imx Files specific to Freescale MC9328 i.MX CPUs 157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs 158 /arm925t Files specific to ARM 925 CPUs 159 /arm926ejs Files specific to ARM 926 CPUs 160 /arm1136 Files specific to ARM 1136 CPUs 161 /ixp Files specific to Intel XScale IXP CPUs 162 /pxa Files specific to Intel XScale PXA CPUs 163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs 164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs 165 /lib Architecture specific library files 166 /avr32 Files generic to AVR32 architecture 167 /cpu CPU specific files 168 /lib Architecture specific library files 169 /blackfin Files generic to Analog Devices Blackfin architecture 170 /cpu CPU specific files 171 /lib Architecture specific library files 172 /x86 Files generic to x86 architecture 173 /cpu CPU specific files 174 /lib Architecture specific library files 175 /m68k Files generic to m68k architecture 176 /cpu CPU specific files 177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 182 /lib Architecture specific library files 183 /microblaze Files generic to microblaze architecture 184 /cpu CPU specific files 185 /lib Architecture specific library files 186 /mips Files generic to MIPS architecture 187 /cpu CPU specific files 188 /mips32 Files specific to MIPS32 CPUs 189 /xburst Files specific to Ingenic XBurst CPUs 190 /lib Architecture specific library files 191 /nds32 Files generic to NDS32 architecture 192 /cpu CPU specific files 193 /n1213 Files specific to Andes Technology N1213 CPUs 194 /lib Architecture specific library files 195 /nios2 Files generic to Altera NIOS2 architecture 196 /cpu CPU specific files 197 /lib Architecture specific library files 198 /powerpc Files generic to PowerPC architecture 199 /cpu CPU specific files 200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs 201 /mpc5xx Files specific to Freescale MPC5xx CPUs 202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs 203 /mpc8xx Files specific to Freescale MPC8xx CPUs 204 /mpc8220 Files specific to Freescale MPC8220 CPUs 205 /mpc824x Files specific to Freescale MPC824x CPUs 206 /mpc8260 Files specific to Freescale MPC8260 CPUs 207 /mpc85xx Files specific to Freescale MPC85xx CPUs 208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs 209 /lib Architecture specific library files 210 /sh Files generic to SH architecture 211 /cpu CPU specific files 212 /sh2 Files specific to sh2 CPUs 213 /sh3 Files specific to sh3 CPUs 214 /sh4 Files specific to sh4 CPUs 215 /lib Architecture specific library files 216 /sparc Files generic to SPARC architecture 217 /cpu CPU specific files 218 /leon2 Files specific to Gaisler LEON2 SPARC CPU 219 /leon3 Files specific to Gaisler LEON3 SPARC CPU 220 /lib Architecture specific library files 221/api Machine/arch independent API for external apps 222/board Board dependent files 223/common Misc architecture independent functions 224/disk Code for disk drive partition handling 225/doc Documentation (don't expect too much) 226/drivers Commonly used device drivers 227/examples Example code for standalone applications, etc. 228/fs Filesystem code (cramfs, ext2, jffs2, etc.) 229/include Header Files 230/lib Files generic to all architectures 231 /libfdt Library files to support flattened device trees 232 /lzma Library files to support LZMA decompression 233 /lzo Library files to support LZO decompression 234/net Networking code 235/post Power On Self Test 236/rtc Real Time Clock drivers 237/tools Tools to build S-Record or U-Boot images, etc. 238 239Software Configuration: 240======================= 241 242Configuration is usually done using C preprocessor defines; the 243rationale behind that is to avoid dead code whenever possible. 244 245There are two classes of configuration variables: 246 247* Configuration _OPTIONS_: 248 These are selectable by the user and have names beginning with 249 "CONFIG_". 250 251* Configuration _SETTINGS_: 252 These depend on the hardware etc. and should not be meddled with if 253 you don't know what you're doing; they have names beginning with 254 "CONFIG_SYS_". 255 256Later we will add a configuration tool - probably similar to or even 257identical to what's used for the Linux kernel. Right now, we have to 258do the configuration by hand, which means creating some symbolic 259links and editing some configuration files. We use the TQM8xxL boards 260as an example here. 261 262 263Selection of Processor Architecture and Board Type: 264--------------------------------------------------- 265 266For all supported boards there are ready-to-use default 267configurations available; just type "make <board_name>_config". 268 269Example: For a TQM823L module type: 270 271 cd u-boot 272 make TQM823L_config 273 274For the Cogent platform, you need to specify the CPU type as well; 275e.g. "make cogent_mpc8xx_config". And also configure the cogent 276directory according to the instructions in cogent/README. 277 278 279Configuration Options: 280---------------------- 281 282Configuration depends on the combination of board and CPU type; all 283such information is kept in a configuration file 284"include/configs/<board_name>.h". 285 286Example: For a TQM823L module, all configuration settings are in 287"include/configs/TQM823L.h". 288 289 290Many of the options are named exactly as the corresponding Linux 291kernel configuration options. The intention is to make it easier to 292build a config tool - later. 293 294 295The following options need to be configured: 296 297- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 298 299- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 300 301- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 302 Define exactly one, e.g. CONFIG_ATSTK1002 303 304- CPU Module Type: (if CONFIG_COGENT is defined) 305 Define exactly one of 306 CONFIG_CMA286_60_OLD 307--- FIXME --- not tested yet: 308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 309 CONFIG_CMA287_23, CONFIG_CMA287_50 310 311- Motherboard Type: (if CONFIG_COGENT is defined) 312 Define exactly one of 313 CONFIG_CMA101, CONFIG_CMA102 314 315- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 316 Define one or more of 317 CONFIG_CMA302 318 319- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 320 Define one or more of 321 CONFIG_LCD_HEARTBEAT - update a character position on 322 the LCD display every second with 323 a "rotator" |\-/|\-/ 324 325- Board flavour: (if CONFIG_MPC8260ADS is defined) 326 CONFIG_ADSTYPE 327 Possible values are: 328 CONFIG_SYS_8260ADS - original MPC8260ADS 329 CONFIG_SYS_8266ADS - MPC8266ADS 330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR 331 CONFIG_SYS_8272ADS - MPC8272ADS 332 333- Marvell Family Member 334 CONFIG_SYS_MVFS - define it if you want to enable 335 multiple fs option at one time 336 for marvell soc family 337 338- MPC824X Family Member (if CONFIG_MPC824X is defined) 339 Define exactly one of 340 CONFIG_MPC8240, CONFIG_MPC8245 341 342- 8xx CPU Options: (if using an MPC8xx CPU) 343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 344 get_gclk_freq() cannot work 345 e.g. if there is no 32KHz 346 reference PIT/RTC clock 347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 348 or XTAL/EXTAL) 349 350- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 351 CONFIG_SYS_8xx_CPUCLK_MIN 352 CONFIG_SYS_8xx_CPUCLK_MAX 353 CONFIG_8xx_CPUCLK_DEFAULT 354 See doc/README.MPC866 355 356 CONFIG_SYS_MEASURE_CPUCLK 357 358 Define this to measure the actual CPU clock instead 359 of relying on the correctness of the configured 360 values. Mostly useful for board bringup to make sure 361 the PLL is locked at the intended frequency. Note 362 that this requires a (stable) reference clock (32 kHz 363 RTC clock or CONFIG_SYS_8XX_XIN) 364 365 CONFIG_SYS_DELAYED_ICACHE 366 367 Define this option if you want to enable the 368 ICache only when Code runs from RAM. 369 370- 85xx CPU Options: 371 CONFIG_SYS_PPC64 372 373 Specifies that the core is a 64-bit PowerPC implementation (implements 374 the "64" category of the Power ISA). This is necessary for ePAPR 375 compliance, among other possible reasons. 376 377 CONFIG_SYS_FSL_TBCLK_DIV 378 379 Defines the core time base clock divider ratio compared to the 380 system clock. On most PQ3 devices this is 8, on newer QorIQ 381 devices it can be 16 or 32. The ratio varies from SoC to Soc. 382 383 CONFIG_SYS_FSL_PCIE_COMPAT 384 385 Defines the string to utilize when trying to match PCIe device 386 tree nodes for the given platform. 387 388 CONFIG_SYS_PPC_E500_DEBUG_TLB 389 390 Enables a temporary TLB entry to be used during boot to work 391 around limitations in e500v1 and e500v2 external debugger 392 support. This reduces the portions of the boot code where 393 breakpoints and single stepping do not work. The value of this 394 symbol should be set to the TLB1 entry to be used for this 395 purpose. 396 397 CONFIG_SYS_FSL_ERRATUM_A004510 398 399 Enables a workaround for erratum A004510. If set, 400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 402 403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 405 406 Defines one or two SoC revisions (low 8 bits of SVR) 407 for which the A004510 workaround should be applied. 408 409 The rest of SVR is either not relevant to the decision 410 of whether the erratum is present (e.g. p2040 versus 411 p2041) or is implied by the build target, which controls 412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 413 414 See Freescale App Note 4493 for more information about 415 this erratum. 416 417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 418 419 This is the value to write into CCSR offset 0x18600 420 according to the A004510 workaround. 421 422- Generic CPU options: 423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 424 425 Defines the endianess of the CPU. Implementation of those 426 values is arch specific. 427 428- Intel Monahans options: 429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO 430 431 Defines the Monahans run mode to oscillator 432 ratio. Valid values are 8, 16, 24, 31. The core 433 frequency is this value multiplied by 13 MHz. 434 435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO 436 437 Defines the Monahans turbo mode to oscillator 438 ratio. Valid values are 1 (default if undefined) and 439 2. The core frequency as calculated above is multiplied 440 by this value. 441 442- MIPS CPU options: 443 CONFIG_SYS_INIT_SP_OFFSET 444 445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 446 pointer. This is needed for the temporary stack before 447 relocation. 448 449 CONFIG_SYS_MIPS_CACHE_MODE 450 451 Cache operation mode for the MIPS CPU. 452 See also arch/mips/include/asm/mipsregs.h. 453 Possible values are: 454 CONF_CM_CACHABLE_NO_WA 455 CONF_CM_CACHABLE_WA 456 CONF_CM_UNCACHED 457 CONF_CM_CACHABLE_NONCOHERENT 458 CONF_CM_CACHABLE_CE 459 CONF_CM_CACHABLE_COW 460 CONF_CM_CACHABLE_CUW 461 CONF_CM_CACHABLE_ACCELERATED 462 463 CONFIG_SYS_XWAY_EBU_BOOTCFG 464 465 Special option for Lantiq XWAY SoCs for booting from NOR flash. 466 See also arch/mips/cpu/mips32/start.S. 467 468 CONFIG_XWAY_SWAP_BYTES 469 470 Enable compilation of tools/xway-swap-bytes needed for Lantiq 471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 472 be swapped if a flash programmer is used. 473 474- ARM options: 475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 476 477 Select high exception vectors of the ARM core, e.g., do not 478 clear the V bit of the c1 register of CP15. 479 480 CONFIG_SYS_THUMB_BUILD 481 482 Use this flag to build U-Boot using the Thumb instruction 483 set for ARM architectures. Thumb instruction set provides 484 better code density. For ARM architectures that support 485 Thumb2 this flag will result in Thumb2 code generated by 486 GCC. 487 488- Linux Kernel Interface: 489 CONFIG_CLOCKS_IN_MHZ 490 491 U-Boot stores all clock information in Hz 492 internally. For binary compatibility with older Linux 493 kernels (which expect the clocks passed in the 494 bd_info data to be in MHz) the environment variable 495 "clocks_in_mhz" can be defined so that U-Boot 496 converts clock data to MHZ before passing it to the 497 Linux kernel. 498 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 499 "clocks_in_mhz=1" is automatically included in the 500 default environment. 501 502 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 503 504 When transferring memsize parameter to linux, some versions 505 expect it to be in bytes, others in MB. 506 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 507 508 CONFIG_OF_LIBFDT 509 510 New kernel versions are expecting firmware settings to be 511 passed using flattened device trees (based on open firmware 512 concepts). 513 514 CONFIG_OF_LIBFDT 515 * New libfdt-based support 516 * Adds the "fdt" command 517 * The bootm command automatically updates the fdt 518 519 OF_CPU - The proper name of the cpus node (only required for 520 MPC512X and MPC5xxx based boards). 521 OF_SOC - The proper name of the soc node (only required for 522 MPC512X and MPC5xxx based boards). 523 OF_TBCLK - The timebase frequency. 524 OF_STDOUT_PATH - The path to the console device 525 526 boards with QUICC Engines require OF_QE to set UCC MAC 527 addresses 528 529 CONFIG_OF_BOARD_SETUP 530 531 Board code has addition modification that it wants to make 532 to the flat device tree before handing it off to the kernel 533 534 CONFIG_OF_BOOT_CPU 535 536 This define fills in the correct boot CPU in the boot 537 param header, the default value is zero if undefined. 538 539 CONFIG_OF_IDE_FIXUP 540 541 U-Boot can detect if an IDE device is present or not. 542 If not, and this new config option is activated, U-Boot 543 removes the ATA node from the DTS before booting Linux, 544 so the Linux IDE driver does not probe the device and 545 crash. This is needed for buggy hardware (uc101) where 546 no pull down resistor is connected to the signal IDE5V_DD7. 547 548 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 549 550 This setting is mandatory for all boards that have only one 551 machine type and must be used to specify the machine type 552 number as it appears in the ARM machine registry 553 (see http://www.arm.linux.org.uk/developer/machines/). 554 Only boards that have multiple machine types supported 555 in a single configuration file and the machine type is 556 runtime discoverable, do not have to use this setting. 557 558- vxWorks boot parameters: 559 560 bootvx constructs a valid bootline using the following 561 environments variables: bootfile, ipaddr, serverip, hostname. 562 It loads the vxWorks image pointed bootfile. 563 564 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name 565 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address 566 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server 567 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters 568 569 CONFIG_SYS_VXWORKS_ADD_PARAMS 570 571 Add it at the end of the bootline. E.g "u=username pw=secret" 572 573 Note: If a "bootargs" environment is defined, it will overwride 574 the defaults discussed just above. 575 576- Cache Configuration: 577 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 578 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 579 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 580 581- Cache Configuration for ARM: 582 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 583 controller 584 CONFIG_SYS_PL310_BASE - Physical base address of PL310 585 controller register space 586 587- Serial Ports: 588 CONFIG_PL010_SERIAL 589 590 Define this if you want support for Amba PrimeCell PL010 UARTs. 591 592 CONFIG_PL011_SERIAL 593 594 Define this if you want support for Amba PrimeCell PL011 UARTs. 595 596 CONFIG_PL011_CLOCK 597 598 If you have Amba PrimeCell PL011 UARTs, set this variable to 599 the clock speed of the UARTs. 600 601 CONFIG_PL01x_PORTS 602 603 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 604 define this to a list of base addresses for each (supported) 605 port. See e.g. include/configs/versatile.h 606 607 CONFIG_PL011_SERIAL_RLCR 608 609 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500) 610 have separate receive and transmit line control registers. Set 611 this variable to initialize the extra register. 612 613 CONFIG_PL011_SERIAL_FLUSH_ON_INIT 614 615 On some platforms (e.g. U8500) U-Boot is loaded by a second stage 616 boot loader that has already initialized the UART. Define this 617 variable to flush the UART at init time. 618 619 620- Console Interface: 621 Depending on board, define exactly one serial port 622 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 623 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 624 console by defining CONFIG_8xx_CONS_NONE 625 626 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 627 port routines must be defined elsewhere 628 (i.e. serial_init(), serial_getc(), ...) 629 630 CONFIG_CFB_CONSOLE 631 Enables console device for a color framebuffer. Needs following 632 defines (cf. smiLynxEM, i8042) 633 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 634 (default big endian) 635 VIDEO_HW_RECTFILL graphic chip supports 636 rectangle fill 637 (cf. smiLynxEM) 638 VIDEO_HW_BITBLT graphic chip supports 639 bit-blit (cf. smiLynxEM) 640 VIDEO_VISIBLE_COLS visible pixel columns 641 (cols=pitch) 642 VIDEO_VISIBLE_ROWS visible pixel rows 643 VIDEO_PIXEL_SIZE bytes per pixel 644 VIDEO_DATA_FORMAT graphic data format 645 (0-5, cf. cfb_console.c) 646 VIDEO_FB_ADRS framebuffer address 647 VIDEO_KBD_INIT_FCT keyboard int fct 648 (i.e. i8042_kbd_init()) 649 VIDEO_TSTC_FCT test char fct 650 (i.e. i8042_tstc) 651 VIDEO_GETC_FCT get char fct 652 (i.e. i8042_getc) 653 CONFIG_CONSOLE_CURSOR cursor drawing on/off 654 (requires blink timer 655 cf. i8042.c) 656 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 657 CONFIG_CONSOLE_TIME display time/date info in 658 upper right corner 659 (requires CONFIG_CMD_DATE) 660 CONFIG_VIDEO_LOGO display Linux logo in 661 upper left corner 662 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 663 linux_logo.h for logo. 664 Requires CONFIG_VIDEO_LOGO 665 CONFIG_CONSOLE_EXTRA_INFO 666 additional board info beside 667 the logo 668 669 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support 670 a limited number of ANSI escape sequences (cursor control, 671 erase functions and limited graphics rendition control). 672 673 When CONFIG_CFB_CONSOLE is defined, video console is 674 default i/o. Serial console can be forced with 675 environment 'console=serial'. 676 677 When CONFIG_SILENT_CONSOLE is defined, all console 678 messages (by U-Boot and Linux!) can be silenced with 679 the "silent" environment variable. See 680 doc/README.silent for more information. 681 682- Console Baudrate: 683 CONFIG_BAUDRATE - in bps 684 Select one of the baudrates listed in 685 CONFIG_SYS_BAUDRATE_TABLE, see below. 686 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 687 688- Console Rx buffer length 689 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 690 the maximum receive buffer length for the SMC. 691 This option is actual only for 82xx and 8xx possible. 692 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 693 must be defined, to setup the maximum idle timeout for 694 the SMC. 695 696- Pre-Console Buffer: 697 Prior to the console being initialised (i.e. serial UART 698 initialised etc) all console output is silently discarded. 699 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to 700 buffer any console messages prior to the console being 701 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ 702 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is 703 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ 704 bytes are output before the console is initialised, the 705 earlier bytes are discarded. 706 707 'Sane' compilers will generate smaller code if 708 CONFIG_PRE_CON_BUF_SZ is a power of 2 709 710- Safe printf() functions 711 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of 712 the printf() functions. These are defined in 713 include/vsprintf.h and include snprintf(), vsnprintf() and 714 so on. Code size increase is approximately 300-500 bytes. 715 If this option is not given then these functions will 716 silently discard their buffer size argument - this means 717 you are not getting any overflow checking in this case. 718 719- Boot Delay: CONFIG_BOOTDELAY - in seconds 720 Delay before automatically booting the default image; 721 set to -1 to disable autoboot. 722 set to -2 to autoboot with no delay and not check for abort 723 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined). 724 725 See doc/README.autoboot for these options that 726 work with CONFIG_BOOTDELAY. None are required. 727 CONFIG_BOOT_RETRY_TIME 728 CONFIG_BOOT_RETRY_MIN 729 CONFIG_AUTOBOOT_KEYED 730 CONFIG_AUTOBOOT_PROMPT 731 CONFIG_AUTOBOOT_DELAY_STR 732 CONFIG_AUTOBOOT_STOP_STR 733 CONFIG_AUTOBOOT_DELAY_STR2 734 CONFIG_AUTOBOOT_STOP_STR2 735 CONFIG_ZERO_BOOTDELAY_CHECK 736 CONFIG_RESET_TO_RETRY 737 738- Autoboot Command: 739 CONFIG_BOOTCOMMAND 740 Only needed when CONFIG_BOOTDELAY is enabled; 741 define a command string that is automatically executed 742 when no character is read on the console interface 743 within "Boot Delay" after reset. 744 745 CONFIG_BOOTARGS 746 This can be used to pass arguments to the bootm 747 command. The value of CONFIG_BOOTARGS goes into the 748 environment value "bootargs". 749 750 CONFIG_RAMBOOT and CONFIG_NFSBOOT 751 The value of these goes into the environment as 752 "ramboot" and "nfsboot" respectively, and can be used 753 as a convenience, when switching between booting from 754 RAM and NFS. 755 756- Pre-Boot Commands: 757 CONFIG_PREBOOT 758 759 When this option is #defined, the existence of the 760 environment variable "preboot" will be checked 761 immediately before starting the CONFIG_BOOTDELAY 762 countdown and/or running the auto-boot command resp. 763 entering interactive mode. 764 765 This feature is especially useful when "preboot" is 766 automatically generated or modified. For an example 767 see the LWMON board specific code: here "preboot" is 768 modified when the user holds down a certain 769 combination of keys on the (special) keyboard when 770 booting the systems 771 772- Serial Download Echo Mode: 773 CONFIG_LOADS_ECHO 774 If defined to 1, all characters received during a 775 serial download (using the "loads" command) are 776 echoed back. This might be needed by some terminal 777 emulations (like "cu"), but may as well just take 778 time on others. This setting #define's the initial 779 value of the "loads_echo" environment variable. 780 781- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 782 CONFIG_KGDB_BAUDRATE 783 Select one of the baudrates listed in 784 CONFIG_SYS_BAUDRATE_TABLE, see below. 785 786- Monitor Functions: 787 Monitor commands can be included or excluded 788 from the build by using the #include files 789 <config_cmd_all.h> and #undef'ing unwanted 790 commands, or using <config_cmd_default.h> 791 and augmenting with additional #define's 792 for wanted commands. 793 794 The default command configuration includes all commands 795 except those marked below with a "*". 796 797 CONFIG_CMD_ASKENV * ask for env variable 798 CONFIG_CMD_BDI bdinfo 799 CONFIG_CMD_BEDBUG * Include BedBug Debugger 800 CONFIG_CMD_BMP * BMP support 801 CONFIG_CMD_BSP * Board specific commands 802 CONFIG_CMD_BOOTD bootd 803 CONFIG_CMD_CACHE * icache, dcache 804 CONFIG_CMD_CONSOLE coninfo 805 CONFIG_CMD_CRC32 * crc32 806 CONFIG_CMD_DATE * support for RTC, date/time... 807 CONFIG_CMD_DHCP * DHCP support 808 CONFIG_CMD_DIAG * Diagnostics 809 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 810 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 811 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 812 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 813 CONFIG_CMD_DTT * Digital Therm and Thermostat 814 CONFIG_CMD_ECHO echo arguments 815 CONFIG_CMD_EDITENV edit env variable 816 CONFIG_CMD_EEPROM * EEPROM read/write support 817 CONFIG_CMD_ELF * bootelf, bootvx 818 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 819 CONFIG_CMD_ENV_FLAGS * display details about env flags 820 CONFIG_CMD_EXPORTENV * export the environment 821 CONFIG_CMD_EXT2 * ext2 command support 822 CONFIG_CMD_EXT4 * ext4 command support 823 CONFIG_CMD_SAVEENV saveenv 824 CONFIG_CMD_FDC * Floppy Disk Support 825 CONFIG_CMD_FAT * FAT command support 826 CONFIG_CMD_FDOS * Dos diskette Support 827 CONFIG_CMD_FLASH flinfo, erase, protect 828 CONFIG_CMD_FPGA FPGA device initialization support 829 CONFIG_CMD_GETTIME * Get time since boot 830 CONFIG_CMD_GO * the 'go' command (exec code) 831 CONFIG_CMD_GREPENV * search environment 832 CONFIG_CMD_HASH * calculate hash / digest 833 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 834 CONFIG_CMD_I2C * I2C serial bus support 835 CONFIG_CMD_IDE * IDE harddisk support 836 CONFIG_CMD_IMI iminfo 837 CONFIG_CMD_IMLS List all found images 838 CONFIG_CMD_IMMAP * IMMR dump support 839 CONFIG_CMD_IMPORTENV * import an environment 840 CONFIG_CMD_INI * import data from an ini file into the env 841 CONFIG_CMD_IRQ * irqinfo 842 CONFIG_CMD_ITEST Integer/string test of 2 values 843 CONFIG_CMD_JFFS2 * JFFS2 Support 844 CONFIG_CMD_KGDB * kgdb 845 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader) 846 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 847 (169.254.*.*) 848 CONFIG_CMD_LOADB loadb 849 CONFIG_CMD_LOADS loads 850 CONFIG_CMD_MD5SUM print md5 message digest 851 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 852 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 853 loop, loopw, mtest 854 CONFIG_CMD_MISC Misc functions like sleep etc 855 CONFIG_CMD_MMC * MMC memory mapped support 856 CONFIG_CMD_MII * MII utility commands 857 CONFIG_CMD_MTDPARTS * MTD partition support 858 CONFIG_CMD_NAND * NAND support 859 CONFIG_CMD_NET bootp, tftpboot, rarpboot 860 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 861 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 862 CONFIG_CMD_PCI * pciinfo 863 CONFIG_CMD_PCMCIA * PCMCIA support 864 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 865 host 866 CONFIG_CMD_PORTIO * Port I/O 867 CONFIG_CMD_READ * Read raw data from partition 868 CONFIG_CMD_REGINFO * Register dump 869 CONFIG_CMD_RUN run command in env variable 870 CONFIG_CMD_SAVES * save S record dump 871 CONFIG_CMD_SCSI * SCSI Support 872 CONFIG_CMD_SDRAM * print SDRAM configuration information 873 (requires CONFIG_CMD_I2C) 874 CONFIG_CMD_SETGETDCR Support for DCR Register access 875 (4xx only) 876 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 877 CONFIG_CMD_SHA1SUM print sha1 memory digest 878 (requires CONFIG_CMD_MEMORY) 879 CONFIG_CMD_SOURCE "source" command Support 880 CONFIG_CMD_SPI * SPI serial bus support 881 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 882 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 883 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 884 CONFIG_CMD_TIMER * access to the system tick timer 885 CONFIG_CMD_USB * USB support 886 CONFIG_CMD_CDP * Cisco Discover Protocol support 887 CONFIG_CMD_MFSL * Microblaze FSL support 888 889 890 EXAMPLE: If you want all functions except of network 891 support you can write: 892 893 #include "config_cmd_all.h" 894 #undef CONFIG_CMD_NET 895 896 Other Commands: 897 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 898 899 Note: Don't enable the "icache" and "dcache" commands 900 (configuration option CONFIG_CMD_CACHE) unless you know 901 what you (and your U-Boot users) are doing. Data 902 cache cannot be enabled on systems like the 8xx or 903 8260 (where accesses to the IMMR region must be 904 uncached), and it cannot be disabled on all other 905 systems where we (mis-) use the data cache to hold an 906 initial stack and some data. 907 908 909 XXX - this list needs to get updated! 910 911- Device tree: 912 CONFIG_OF_CONTROL 913 If this variable is defined, U-Boot will use a device tree 914 to configure its devices, instead of relying on statically 915 compiled #defines in the board file. This option is 916 experimental and only available on a few boards. The device 917 tree is available in the global data as gd->fdt_blob. 918 919 U-Boot needs to get its device tree from somewhere. This can 920 be done using one of the two options below: 921 922 CONFIG_OF_EMBED 923 If this variable is defined, U-Boot will embed a device tree 924 binary in its image. This device tree file should be in the 925 board directory and called <soc>-<board>.dts. The binary file 926 is then picked up in board_init_f() and made available through 927 the global data structure as gd->blob. 928 929 CONFIG_OF_SEPARATE 930 If this variable is defined, U-Boot will build a device tree 931 binary. It will be called u-boot.dtb. Architecture-specific 932 code will locate it at run-time. Generally this works by: 933 934 cat u-boot.bin u-boot.dtb >image.bin 935 936 and in fact, U-Boot does this for you, creating a file called 937 u-boot-dtb.bin which is useful in the common case. You can 938 still use the individual files if you need something more 939 exotic. 940 941- Watchdog: 942 CONFIG_WATCHDOG 943 If this variable is defined, it enables watchdog 944 support for the SoC. There must be support in the SoC 945 specific code for a watchdog. For the 8xx and 8260 946 CPUs, the SIU Watchdog feature is enabled in the SYPCR 947 register. When supported for a specific SoC is 948 available, then no further board specific code should 949 be needed to use it. 950 951 CONFIG_HW_WATCHDOG 952 When using a watchdog circuitry external to the used 953 SoC, then define this variable and provide board 954 specific code for the "hw_watchdog_reset" function. 955 956- U-Boot Version: 957 CONFIG_VERSION_VARIABLE 958 If this variable is defined, an environment variable 959 named "ver" is created by U-Boot showing the U-Boot 960 version as printed by the "version" command. 961 Any change to this variable will be reverted at the 962 next reset. 963 964- Real-Time Clock: 965 966 When CONFIG_CMD_DATE is selected, the type of the RTC 967 has to be selected, too. Define exactly one of the 968 following options: 969 970 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 971 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 972 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 973 CONFIG_RTC_MC146818 - use MC146818 RTC 974 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 975 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 976 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 977 CONFIG_RTC_DS164x - use Dallas DS164x RTC 978 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 979 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 980 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 981 CONFIG_SYS_RV3029_TCR - enable trickle charger on 982 RV3029 RTC. 983 984 Note that if the RTC uses I2C, then the I2C interface 985 must also be configured. See I2C Support, below. 986 987- GPIO Support: 988 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 989 CONFIG_PCA953X_INFO - enable pca953x info command 990 991 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 992 chip-ngpio pairs that tell the PCA953X driver the number of 993 pins supported by a particular chip. 994 995 Note that if the GPIO device uses I2C, then the I2C interface 996 must also be configured. See I2C Support, below. 997 998- Timestamp Support: 999 1000 When CONFIG_TIMESTAMP is selected, the timestamp 1001 (date and time) of an image is printed by image 1002 commands like bootm or iminfo. This option is 1003 automatically enabled when you select CONFIG_CMD_DATE . 1004 1005- Partition Labels (disklabels) Supported: 1006 Zero or more of the following: 1007 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1008 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1009 Intel architecture, USB sticks, etc. 1010 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1011 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1012 bootloader. Note 2TB partition limit; see 1013 disk/part_efi.c 1014 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1015 1016 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1017 CONFIG_CMD_SCSI) you must configure support for at 1018 least one non-MTD partition type as well. 1019 1020- IDE Reset method: 1021 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1022 board configurations files but used nowhere! 1023 1024 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1025 be performed by calling the function 1026 ide_set_reset(int reset) 1027 which has to be defined in a board specific file 1028 1029- ATAPI Support: 1030 CONFIG_ATAPI 1031 1032 Set this to enable ATAPI support. 1033 1034- LBA48 Support 1035 CONFIG_LBA48 1036 1037 Set this to enable support for disks larger than 137GB 1038 Also look at CONFIG_SYS_64BIT_LBA. 1039 Whithout these , LBA48 support uses 32bit variables and will 'only' 1040 support disks up to 2.1TB. 1041 1042 CONFIG_SYS_64BIT_LBA: 1043 When enabled, makes the IDE subsystem use 64bit sector addresses. 1044 Default is 32bit. 1045 1046- SCSI Support: 1047 At the moment only there is only support for the 1048 SYM53C8XX SCSI controller; define 1049 CONFIG_SCSI_SYM53C8XX to enable it. 1050 1051 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1052 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1053 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1054 maximum numbers of LUNs, SCSI ID's and target 1055 devices. 1056 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1057 1058 The environment variable 'scsidevs' is set to the number of 1059 SCSI devices found during the last scan. 1060 1061- NETWORK Support (PCI): 1062 CONFIG_E1000 1063 Support for Intel 8254x/8257x gigabit chips. 1064 1065 CONFIG_E1000_SPI 1066 Utility code for direct access to the SPI bus on Intel 8257x. 1067 This does not do anything useful unless you set at least one 1068 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1069 1070 CONFIG_E1000_SPI_GENERIC 1071 Allow generic access to the SPI bus on the Intel 8257x, for 1072 example with the "sspi" command. 1073 1074 CONFIG_CMD_E1000 1075 Management command for E1000 devices. When used on devices 1076 with SPI support you can reprogram the EEPROM from U-Boot. 1077 1078 CONFIG_E1000_FALLBACK_MAC 1079 default MAC for empty EEPROM after production. 1080 1081 CONFIG_EEPRO100 1082 Support for Intel 82557/82559/82559ER chips. 1083 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1084 write routine for first time initialisation. 1085 1086 CONFIG_TULIP 1087 Support for Digital 2114x chips. 1088 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1089 modem chip initialisation (KS8761/QS6611). 1090 1091 CONFIG_NATSEMI 1092 Support for National dp83815 chips. 1093 1094 CONFIG_NS8382X 1095 Support for National dp8382[01] gigabit chips. 1096 1097- NETWORK Support (other): 1098 1099 CONFIG_DRIVER_AT91EMAC 1100 Support for AT91RM9200 EMAC. 1101 1102 CONFIG_RMII 1103 Define this to use reduced MII inteface 1104 1105 CONFIG_DRIVER_AT91EMAC_QUIET 1106 If this defined, the driver is quiet. 1107 The driver doen't show link status messages. 1108 1109 CONFIG_CALXEDA_XGMAC 1110 Support for the Calxeda XGMAC device 1111 1112 CONFIG_LAN91C96 1113 Support for SMSC's LAN91C96 chips. 1114 1115 CONFIG_LAN91C96_BASE 1116 Define this to hold the physical address 1117 of the LAN91C96's I/O space 1118 1119 CONFIG_LAN91C96_USE_32_BIT 1120 Define this to enable 32 bit addressing 1121 1122 CONFIG_SMC91111 1123 Support for SMSC's LAN91C111 chip 1124 1125 CONFIG_SMC91111_BASE 1126 Define this to hold the physical address 1127 of the device (I/O space) 1128 1129 CONFIG_SMC_USE_32_BIT 1130 Define this if data bus is 32 bits 1131 1132 CONFIG_SMC_USE_IOFUNCS 1133 Define this to use i/o functions instead of macros 1134 (some hardware wont work with macros) 1135 1136 CONFIG_DRIVER_TI_EMAC 1137 Support for davinci emac 1138 1139 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1140 Define this if you have more then 3 PHYs. 1141 1142 CONFIG_FTGMAC100 1143 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1144 1145 CONFIG_FTGMAC100_EGIGA 1146 Define this to use GE link update with gigabit PHY. 1147 Define this if FTGMAC100 is connected to gigabit PHY. 1148 If your system has 10/100 PHY only, it might not occur 1149 wrong behavior. Because PHY usually return timeout or 1150 useless data when polling gigabit status and gigabit 1151 control registers. This behavior won't affect the 1152 correctnessof 10/100 link speed update. 1153 1154 CONFIG_SMC911X 1155 Support for SMSC's LAN911x and LAN921x chips 1156 1157 CONFIG_SMC911X_BASE 1158 Define this to hold the physical address 1159 of the device (I/O space) 1160 1161 CONFIG_SMC911X_32_BIT 1162 Define this if data bus is 32 bits 1163 1164 CONFIG_SMC911X_16_BIT 1165 Define this if data bus is 16 bits. If your processor 1166 automatically converts one 32 bit word to two 16 bit 1167 words you may also try CONFIG_SMC911X_32_BIT. 1168 1169 CONFIG_SH_ETHER 1170 Support for Renesas on-chip Ethernet controller 1171 1172 CONFIG_SH_ETHER_USE_PORT 1173 Define the number of ports to be used 1174 1175 CONFIG_SH_ETHER_PHY_ADDR 1176 Define the ETH PHY's address 1177 1178 CONFIG_SH_ETHER_CACHE_WRITEBACK 1179 If this option is set, the driver enables cache flush. 1180 1181- TPM Support: 1182 CONFIG_GENERIC_LPC_TPM 1183 Support for generic parallel port TPM devices. Only one device 1184 per system is supported at this time. 1185 1186 CONFIG_TPM_TIS_BASE_ADDRESS 1187 Base address where the generic TPM device is mapped 1188 to. Contemporary x86 systems usually map it at 1189 0xfed40000. 1190 1191- USB Support: 1192 At the moment only the UHCI host controller is 1193 supported (PIP405, MIP405, MPC5200); define 1194 CONFIG_USB_UHCI to enable it. 1195 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1196 and define CONFIG_USB_STORAGE to enable the USB 1197 storage devices. 1198 Note: 1199 Supported are USB Keyboards and USB Floppy drives 1200 (TEAC FD-05PUB). 1201 MPC5200 USB requires additional defines: 1202 CONFIG_USB_CLOCK 1203 for 528 MHz Clock: 0x0001bbbb 1204 CONFIG_PSC3_USB 1205 for USB on PSC3 1206 CONFIG_USB_CONFIG 1207 for differential drivers: 0x00001000 1208 for single ended drivers: 0x00005000 1209 for differential drivers on PSC3: 0x00000100 1210 for single ended drivers on PSC3: 0x00004100 1211 CONFIG_SYS_USB_EVENT_POLL 1212 May be defined to allow interrupt polling 1213 instead of using asynchronous interrupts 1214 1215 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1216 txfilltuning field in the EHCI controller on reset. 1217 1218- USB Device: 1219 Define the below if you wish to use the USB console. 1220 Once firmware is rebuilt from a serial console issue the 1221 command "setenv stdin usbtty; setenv stdout usbtty" and 1222 attach your USB cable. The Unix command "dmesg" should print 1223 it has found a new device. The environment variable usbtty 1224 can be set to gserial or cdc_acm to enable your device to 1225 appear to a USB host as a Linux gserial device or a 1226 Common Device Class Abstract Control Model serial device. 1227 If you select usbtty = gserial you should be able to enumerate 1228 a Linux host by 1229 # modprobe usbserial vendor=0xVendorID product=0xProductID 1230 else if using cdc_acm, simply setting the environment 1231 variable usbtty to be cdc_acm should suffice. The following 1232 might be defined in YourBoardName.h 1233 1234 CONFIG_USB_DEVICE 1235 Define this to build a UDC device 1236 1237 CONFIG_USB_TTY 1238 Define this to have a tty type of device available to 1239 talk to the UDC device 1240 1241 CONFIG_USBD_HS 1242 Define this to enable the high speed support for usb 1243 device and usbtty. If this feature is enabled, a routine 1244 int is_usbd_high_speed(void) 1245 also needs to be defined by the driver to dynamically poll 1246 whether the enumeration has succeded at high speed or full 1247 speed. 1248 1249 CONFIG_SYS_CONSOLE_IS_IN_ENV 1250 Define this if you want stdin, stdout &/or stderr to 1251 be set to usbtty. 1252 1253 mpc8xx: 1254 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1255 Derive USB clock from external clock "blah" 1256 - CONFIG_SYS_USB_EXTC_CLK 0x02 1257 1258 CONFIG_SYS_USB_BRG_CLK 0xBLAH 1259 Derive USB clock from brgclk 1260 - CONFIG_SYS_USB_BRG_CLK 0x04 1261 1262 If you have a USB-IF assigned VendorID then you may wish to 1263 define your own vendor specific values either in BoardName.h 1264 or directly in usbd_vendor_info.h. If you don't define 1265 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1266 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1267 should pretend to be a Linux device to it's target host. 1268 1269 CONFIG_USBD_MANUFACTURER 1270 Define this string as the name of your company for 1271 - CONFIG_USBD_MANUFACTURER "my company" 1272 1273 CONFIG_USBD_PRODUCT_NAME 1274 Define this string as the name of your product 1275 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1276 1277 CONFIG_USBD_VENDORID 1278 Define this as your assigned Vendor ID from the USB 1279 Implementors Forum. This *must* be a genuine Vendor ID 1280 to avoid polluting the USB namespace. 1281 - CONFIG_USBD_VENDORID 0xFFFF 1282 1283 CONFIG_USBD_PRODUCTID 1284 Define this as the unique Product ID 1285 for your device 1286 - CONFIG_USBD_PRODUCTID 0xFFFF 1287 1288- ULPI Layer Support: 1289 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1290 the generic ULPI layer. The generic layer accesses the ULPI PHY 1291 via the platform viewport, so you need both the genric layer and 1292 the viewport enabled. Currently only Chipidea/ARC based 1293 viewport is supported. 1294 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1295 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1296 If your ULPI phy needs a different reference clock than the 1297 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1298 the appropriate value in Hz. 1299 1300- MMC Support: 1301 The MMC controller on the Intel PXA is supported. To 1302 enable this define CONFIG_MMC. The MMC can be 1303 accessed from the boot prompt by mapping the device 1304 to physical memory similar to flash. Command line is 1305 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1306 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1307 1308 CONFIG_SH_MMCIF 1309 Support for Renesas on-chip MMCIF controller 1310 1311 CONFIG_SH_MMCIF_ADDR 1312 Define the base address of MMCIF registers 1313 1314 CONFIG_SH_MMCIF_CLK 1315 Define the clock frequency for MMCIF 1316 1317- Journaling Flash filesystem support: 1318 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 1319 CONFIG_JFFS2_NAND_DEV 1320 Define these for a default partition on a NAND device 1321 1322 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1323 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1324 Define these for a default partition on a NOR device 1325 1326 CONFIG_SYS_JFFS_CUSTOM_PART 1327 Define this to create an own partition. You have to provide a 1328 function struct part_info* jffs2_part_info(int part_num) 1329 1330 If you define only one JFFS2 partition you may also want to 1331 #define CONFIG_SYS_JFFS_SINGLE_PART 1 1332 to disable the command chpart. This is the default when you 1333 have not defined a custom partition 1334 1335- FAT(File Allocation Table) filesystem write function support: 1336 CONFIG_FAT_WRITE 1337 1338 Define this to enable support for saving memory data as a 1339 file in FAT formatted partition. 1340 1341 This will also enable the command "fatwrite" enabling the 1342 user to write files to FAT. 1343 1344CBFS (Coreboot Filesystem) support 1345 CONFIG_CMD_CBFS 1346 1347 Define this to enable support for reading from a Coreboot 1348 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1349 and cbfsload. 1350 1351- Keyboard Support: 1352 CONFIG_ISA_KEYBOARD 1353 1354 Define this to enable standard (PC-Style) keyboard 1355 support 1356 1357 CONFIG_I8042_KBD 1358 Standard PC keyboard driver with US (is default) and 1359 GERMAN key layout (switch via environment 'keymap=de') support. 1360 Export function i8042_kbd_init, i8042_tstc and i8042_getc 1361 for cfb_console. Supports cursor blinking. 1362 1363- Video support: 1364 CONFIG_VIDEO 1365 1366 Define this to enable video support (for output to 1367 video). 1368 1369 CONFIG_VIDEO_CT69000 1370 1371 Enable Chips & Technologies 69000 Video chip 1372 1373 CONFIG_VIDEO_SMI_LYNXEM 1374 Enable Silicon Motion SMI 712/710/810 Video chip. The 1375 video output is selected via environment 'videoout' 1376 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 1377 assumed. 1378 1379 For the CT69000 and SMI_LYNXEM drivers, videomode is 1380 selected via environment 'videomode'. Two different ways 1381 are possible: 1382 - "videomode=num" 'num' is a standard LiLo mode numbers. 1383 Following standard modes are supported (* is default): 1384 1385 Colors 640x480 800x600 1024x768 1152x864 1280x1024 1386 -------------+--------------------------------------------- 1387 8 bits | 0x301* 0x303 0x305 0x161 0x307 1388 15 bits | 0x310 0x313 0x316 0x162 0x319 1389 16 bits | 0x311 0x314 0x317 0x163 0x31A 1390 24 bits | 0x312 0x315 0x318 ? 0x31B 1391 -------------+--------------------------------------------- 1392 (i.e. setenv videomode 317; saveenv; reset;) 1393 1394 - "videomode=bootargs" all the video parameters are parsed 1395 from the bootargs. (See drivers/video/videomodes.c) 1396 1397 1398 CONFIG_VIDEO_SED13806 1399 Enable Epson SED13806 driver. This driver supports 8bpp 1400 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 1401 or CONFIG_VIDEO_SED13806_16BPP 1402 1403 CONFIG_FSL_DIU_FB 1404 Enable the Freescale DIU video driver. Reference boards for 1405 SOCs that have a DIU should define this macro to enable DIU 1406 support, and should also define these other macros: 1407 1408 CONFIG_SYS_DIU_ADDR 1409 CONFIG_VIDEO 1410 CONFIG_CMD_BMP 1411 CONFIG_CFB_CONSOLE 1412 CONFIG_VIDEO_SW_CURSOR 1413 CONFIG_VGA_AS_SINGLE_DEVICE 1414 CONFIG_VIDEO_LOGO 1415 CONFIG_VIDEO_BMP_LOGO 1416 1417 The DIU driver will look for the 'video-mode' environment 1418 variable, and if defined, enable the DIU as a console during 1419 boot. See the documentation file README.video for a 1420 description of this variable. 1421 1422 CONFIG_VIDEO_VGA 1423 1424 Enable the VGA video / BIOS for x86. The alternative if you 1425 are using coreboot is to use the coreboot frame buffer 1426 driver. 1427 1428 1429- Keyboard Support: 1430 CONFIG_KEYBOARD 1431 1432 Define this to enable a custom keyboard support. 1433 This simply calls drv_keyboard_init() which must be 1434 defined in your board-specific files. 1435 The only board using this so far is RBC823. 1436 1437- LCD Support: CONFIG_LCD 1438 1439 Define this to enable LCD support (for output to LCD 1440 display); also select one of the supported displays 1441 by defining one of these: 1442 1443 CONFIG_ATMEL_LCD: 1444 1445 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1446 1447 CONFIG_NEC_NL6448AC33: 1448 1449 NEC NL6448AC33-18. Active, color, single scan. 1450 1451 CONFIG_NEC_NL6448BC20 1452 1453 NEC NL6448BC20-08. 6.5", 640x480. 1454 Active, color, single scan. 1455 1456 CONFIG_NEC_NL6448BC33_54 1457 1458 NEC NL6448BC33-54. 10.4", 640x480. 1459 Active, color, single scan. 1460 1461 CONFIG_SHARP_16x9 1462 1463 Sharp 320x240. Active, color, single scan. 1464 It isn't 16x9, and I am not sure what it is. 1465 1466 CONFIG_SHARP_LQ64D341 1467 1468 Sharp LQ64D341 display, 640x480. 1469 Active, color, single scan. 1470 1471 CONFIG_HLD1045 1472 1473 HLD1045 display, 640x480. 1474 Active, color, single scan. 1475 1476 CONFIG_OPTREX_BW 1477 1478 Optrex CBL50840-2 NF-FW 99 22 M5 1479 or 1480 Hitachi LMG6912RPFC-00T 1481 or 1482 Hitachi SP14Q002 1483 1484 320x240. Black & white. 1485 1486 Normally display is black on white background; define 1487 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1488 1489 CONFIG_LCD_ALIGNMENT 1490 1491 Normally the LCD is page-aligned (tyically 4KB). If this is 1492 defined then the LCD will be aligned to this value instead. 1493 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1494 here, since it is cheaper to change data cache settings on 1495 a per-section basis. 1496 1497 CONFIG_CONSOLE_SCROLL_LINES 1498 1499 When the console need to be scrolled, this is the number of 1500 lines to scroll by. It defaults to 1. Increasing this makes 1501 the console jump but can help speed up operation when scrolling 1502 is slow. 1503 1504 CONFIG_LCD_BMP_RLE8 1505 1506 Support drawing of RLE8-compressed bitmaps on the LCD. 1507 1508 CONFIG_I2C_EDID 1509 1510 Enables an 'i2c edid' command which can read EDID 1511 information over I2C from an attached LCD display. 1512 1513- Splash Screen Support: CONFIG_SPLASH_SCREEN 1514 1515 If this option is set, the environment is checked for 1516 a variable "splashimage". If found, the usual display 1517 of logo, copyright and system information on the LCD 1518 is suppressed and the BMP image at the address 1519 specified in "splashimage" is loaded instead. The 1520 console is redirected to the "nulldev", too. This 1521 allows for a "silent" boot where a splash screen is 1522 loaded very quickly after power-on. 1523 1524 CONFIG_SPLASH_SCREEN_ALIGN 1525 1526 If this option is set the splash image can be freely positioned 1527 on the screen. Environment variable "splashpos" specifies the 1528 position as "x,y". If a positive number is given it is used as 1529 number of pixel from left/top. If a negative number is given it 1530 is used as number of pixel from right/bottom. You can also 1531 specify 'm' for centering the image. 1532 1533 Example: 1534 setenv splashpos m,m 1535 => image at center of screen 1536 1537 setenv splashpos 30,20 1538 => image at x = 30 and y = 20 1539 1540 setenv splashpos -10,m 1541 => vertically centered image 1542 at x = dspWidth - bmpWidth - 9 1543 1544- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1545 1546 If this option is set, additionally to standard BMP 1547 images, gzipped BMP images can be displayed via the 1548 splashscreen support or the bmp command. 1549 1550- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1551 1552 If this option is set, 8-bit RLE compressed BMP images 1553 can be displayed via the splashscreen support or the 1554 bmp command. 1555 1556- Do compresssing for memory range: 1557 CONFIG_CMD_ZIP 1558 1559 If this option is set, it would use zlib deflate method 1560 to compress the specified memory at its best effort. 1561 1562- Compression support: 1563 CONFIG_BZIP2 1564 1565 If this option is set, support for bzip2 compressed 1566 images is included. If not, only uncompressed and gzip 1567 compressed images are supported. 1568 1569 NOTE: the bzip2 algorithm requires a lot of RAM, so 1570 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1571 be at least 4MB. 1572 1573 CONFIG_LZMA 1574 1575 If this option is set, support for lzma compressed 1576 images is included. 1577 1578 Note: The LZMA algorithm adds between 2 and 4KB of code and it 1579 requires an amount of dynamic memory that is given by the 1580 formula: 1581 1582 (1846 + 768 << (lc + lp)) * sizeof(uint16) 1583 1584 Where lc and lp stand for, respectively, Literal context bits 1585 and Literal pos bits. 1586 1587 This value is upper-bounded by 14MB in the worst case. Anyway, 1588 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 1589 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 1590 a very small buffer. 1591 1592 Use the lzmainfo tool to determinate the lc and lp values and 1593 then calculate the amount of needed dynamic memory (ensuring 1594 the appropriate CONFIG_SYS_MALLOC_LEN value). 1595 1596- MII/PHY support: 1597 CONFIG_PHY_ADDR 1598 1599 The address of PHY on MII bus. 1600 1601 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1602 1603 The clock frequency of the MII bus 1604 1605 CONFIG_PHY_GIGE 1606 1607 If this option is set, support for speed/duplex 1608 detection of gigabit PHY is included. 1609 1610 CONFIG_PHY_RESET_DELAY 1611 1612 Some PHY like Intel LXT971A need extra delay after 1613 reset before any MII register access is possible. 1614 For such PHY, set this option to the usec delay 1615 required. (minimum 300usec for LXT971A) 1616 1617 CONFIG_PHY_CMD_DELAY (ppc4xx) 1618 1619 Some PHY like Intel LXT971A need extra delay after 1620 command issued before MII status register can be read 1621 1622- Ethernet address: 1623 CONFIG_ETHADDR 1624 CONFIG_ETH1ADDR 1625 CONFIG_ETH2ADDR 1626 CONFIG_ETH3ADDR 1627 CONFIG_ETH4ADDR 1628 CONFIG_ETH5ADDR 1629 1630 Define a default value for Ethernet address to use 1631 for the respective Ethernet interface, in case this 1632 is not determined automatically. 1633 1634- IP address: 1635 CONFIG_IPADDR 1636 1637 Define a default value for the IP address to use for 1638 the default Ethernet interface, in case this is not 1639 determined through e.g. bootp. 1640 (Environment variable "ipaddr") 1641 1642- Server IP address: 1643 CONFIG_SERVERIP 1644 1645 Defines a default value for the IP address of a TFTP 1646 server to contact when using the "tftboot" command. 1647 (Environment variable "serverip") 1648 1649 CONFIG_KEEP_SERVERADDR 1650 1651 Keeps the server's MAC address, in the env 'serveraddr' 1652 for passing to bootargs (like Linux's netconsole option) 1653 1654- Gateway IP address: 1655 CONFIG_GATEWAYIP 1656 1657 Defines a default value for the IP address of the 1658 default router where packets to other networks are 1659 sent to. 1660 (Environment variable "gatewayip") 1661 1662- Subnet mask: 1663 CONFIG_NETMASK 1664 1665 Defines a default value for the subnet mask (or 1666 routing prefix) which is used to determine if an IP 1667 address belongs to the local subnet or needs to be 1668 forwarded through a router. 1669 (Environment variable "netmask") 1670 1671- Multicast TFTP Mode: 1672 CONFIG_MCAST_TFTP 1673 1674 Defines whether you want to support multicast TFTP as per 1675 rfc-2090; for example to work with atftp. Lets lots of targets 1676 tftp down the same boot image concurrently. Note: the Ethernet 1677 driver in use must provide a function: mcast() to join/leave a 1678 multicast group. 1679 1680- BOOTP Recovery Mode: 1681 CONFIG_BOOTP_RANDOM_DELAY 1682 1683 If you have many targets in a network that try to 1684 boot using BOOTP, you may want to avoid that all 1685 systems send out BOOTP requests at precisely the same 1686 moment (which would happen for instance at recovery 1687 from a power failure, when all systems will try to 1688 boot, thus flooding the BOOTP server. Defining 1689 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1690 inserted before sending out BOOTP requests. The 1691 following delays are inserted then: 1692 1693 1st BOOTP request: delay 0 ... 1 sec 1694 2nd BOOTP request: delay 0 ... 2 sec 1695 3rd BOOTP request: delay 0 ... 4 sec 1696 4th and following 1697 BOOTP requests: delay 0 ... 8 sec 1698 1699- DHCP Advanced Options: 1700 You can fine tune the DHCP functionality by defining 1701 CONFIG_BOOTP_* symbols: 1702 1703 CONFIG_BOOTP_SUBNETMASK 1704 CONFIG_BOOTP_GATEWAY 1705 CONFIG_BOOTP_HOSTNAME 1706 CONFIG_BOOTP_NISDOMAIN 1707 CONFIG_BOOTP_BOOTPATH 1708 CONFIG_BOOTP_BOOTFILESIZE 1709 CONFIG_BOOTP_DNS 1710 CONFIG_BOOTP_DNS2 1711 CONFIG_BOOTP_SEND_HOSTNAME 1712 CONFIG_BOOTP_NTPSERVER 1713 CONFIG_BOOTP_TIMEOFFSET 1714 CONFIG_BOOTP_VENDOREX 1715 CONFIG_BOOTP_MAY_FAIL 1716 1717 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1718 environment variable, not the BOOTP server. 1719 1720 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1721 after the configured retry count, the call will fail 1722 instead of starting over. This can be used to fail over 1723 to Link-local IP address configuration if the DHCP server 1724 is not available. 1725 1726 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1727 serverip from a DHCP server, it is possible that more 1728 than one DNS serverip is offered to the client. 1729 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1730 serverip will be stored in the additional environment 1731 variable "dnsip2". The first DNS serverip is always 1732 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1733 is defined. 1734 1735 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1736 to do a dynamic update of a DNS server. To do this, they 1737 need the hostname of the DHCP requester. 1738 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1739 of the "hostname" environment variable is passed as 1740 option 12 to the DHCP server. 1741 1742 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1743 1744 A 32bit value in microseconds for a delay between 1745 receiving a "DHCP Offer" and sending the "DHCP Request". 1746 This fixes a problem with certain DHCP servers that don't 1747 respond 100% of the time to a "DHCP request". E.g. On an 1748 AT91RM9200 processor running at 180MHz, this delay needed 1749 to be *at least* 15,000 usec before a Windows Server 2003 1750 DHCP server would reply 100% of the time. I recommend at 1751 least 50,000 usec to be safe. The alternative is to hope 1752 that one of the retries will be successful but note that 1753 the DHCP timeout and retry process takes a longer than 1754 this delay. 1755 1756 - Link-local IP address negotiation: 1757 Negotiate with other link-local clients on the local network 1758 for an address that doesn't require explicit configuration. 1759 This is especially useful if a DHCP server cannot be guaranteed 1760 to exist in all environments that the device must operate. 1761 1762 See doc/README.link-local for more information. 1763 1764 - CDP Options: 1765 CONFIG_CDP_DEVICE_ID 1766 1767 The device id used in CDP trigger frames. 1768 1769 CONFIG_CDP_DEVICE_ID_PREFIX 1770 1771 A two character string which is prefixed to the MAC address 1772 of the device. 1773 1774 CONFIG_CDP_PORT_ID 1775 1776 A printf format string which contains the ascii name of 1777 the port. Normally is set to "eth%d" which sets 1778 eth0 for the first Ethernet, eth1 for the second etc. 1779 1780 CONFIG_CDP_CAPABILITIES 1781 1782 A 32bit integer which indicates the device capabilities; 1783 0x00000010 for a normal host which does not forwards. 1784 1785 CONFIG_CDP_VERSION 1786 1787 An ascii string containing the version of the software. 1788 1789 CONFIG_CDP_PLATFORM 1790 1791 An ascii string containing the name of the platform. 1792 1793 CONFIG_CDP_TRIGGER 1794 1795 A 32bit integer sent on the trigger. 1796 1797 CONFIG_CDP_POWER_CONSUMPTION 1798 1799 A 16bit integer containing the power consumption of the 1800 device in .1 of milliwatts. 1801 1802 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1803 1804 A byte containing the id of the VLAN. 1805 1806- Status LED: CONFIG_STATUS_LED 1807 1808 Several configurations allow to display the current 1809 status using a LED. For instance, the LED will blink 1810 fast while running U-Boot code, stop blinking as 1811 soon as a reply to a BOOTP request was received, and 1812 start blinking slow once the Linux kernel is running 1813 (supported by a status LED driver in the Linux 1814 kernel). Defining CONFIG_STATUS_LED enables this 1815 feature in U-Boot. 1816 1817- CAN Support: CONFIG_CAN_DRIVER 1818 1819 Defining CONFIG_CAN_DRIVER enables CAN driver support 1820 on those systems that support this (optional) 1821 feature, like the TQM8xxL modules. 1822 1823- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C 1824 1825 These enable I2C serial bus commands. Defining either of 1826 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will 1827 include the appropriate I2C driver for the selected CPU. 1828 1829 This will allow you to use i2c commands at the u-boot 1830 command line (as long as you set CONFIG_CMD_I2C in 1831 CONFIG_COMMANDS) and communicate with i2c based realtime 1832 clock chips. See common/cmd_i2c.c for a description of the 1833 command line interface. 1834 1835 CONFIG_HARD_I2C selects a hardware I2C controller. 1836 1837 CONFIG_SOFT_I2C configures u-boot to use a software (aka 1838 bit-banging) driver instead of CPM or similar hardware 1839 support for I2C. 1840 1841 There are several other quantities that must also be 1842 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C. 1843 1844 In both cases you will need to define CONFIG_SYS_I2C_SPEED 1845 to be the frequency (in Hz) at which you wish your i2c bus 1846 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 1847 the CPU's i2c node address). 1848 1849 Now, the u-boot i2c code for the mpc8xx 1850 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 1851 and so its address should therefore be cleared to 0 (See, 1852 eg, MPC823e User's Manual p.16-473). So, set 1853 CONFIG_SYS_I2C_SLAVE to 0. 1854 1855 CONFIG_SYS_I2C_INIT_MPC5XXX 1856 1857 When a board is reset during an i2c bus transfer 1858 chips might think that the current transfer is still 1859 in progress. Reset the slave devices by sending start 1860 commands until the slave device responds. 1861 1862 That's all that's required for CONFIG_HARD_I2C. 1863 1864 If you use the software i2c interface (CONFIG_SOFT_I2C) 1865 then the following macros need to be defined (examples are 1866 from include/configs/lwmon.h): 1867 1868 I2C_INIT 1869 1870 (Optional). Any commands necessary to enable the I2C 1871 controller or configure ports. 1872 1873 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1874 1875 I2C_PORT 1876 1877 (Only for MPC8260 CPU). The I/O port to use (the code 1878 assumes both bits are on the same port). Valid values 1879 are 0..3 for ports A..D. 1880 1881 I2C_ACTIVE 1882 1883 The code necessary to make the I2C data line active 1884 (driven). If the data line is open collector, this 1885 define can be null. 1886 1887 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1888 1889 I2C_TRISTATE 1890 1891 The code necessary to make the I2C data line tri-stated 1892 (inactive). If the data line is open collector, this 1893 define can be null. 1894 1895 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1896 1897 I2C_READ 1898 1899 Code that returns TRUE if the I2C data line is high, 1900 FALSE if it is low. 1901 1902 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1903 1904 I2C_SDA(bit) 1905 1906 If <bit> is TRUE, sets the I2C data line high. If it 1907 is FALSE, it clears it (low). 1908 1909 eg: #define I2C_SDA(bit) \ 1910 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1911 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1912 1913 I2C_SCL(bit) 1914 1915 If <bit> is TRUE, sets the I2C clock line high. If it 1916 is FALSE, it clears it (low). 1917 1918 eg: #define I2C_SCL(bit) \ 1919 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1920 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1921 1922 I2C_DELAY 1923 1924 This delay is invoked four times per clock cycle so this 1925 controls the rate of data transfer. The data rate thus 1926 is 1 / (I2C_DELAY * 4). Often defined to be something 1927 like: 1928 1929 #define I2C_DELAY udelay(2) 1930 1931 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1932 1933 If your arch supports the generic GPIO framework (asm/gpio.h), 1934 then you may alternatively define the two GPIOs that are to be 1935 used as SCL / SDA. Any of the previous I2C_xxx macros will 1936 have GPIO-based defaults assigned to them as appropriate. 1937 1938 You should define these to the GPIO value as given directly to 1939 the generic GPIO functions. 1940 1941 CONFIG_SYS_I2C_INIT_BOARD 1942 1943 When a board is reset during an i2c bus transfer 1944 chips might think that the current transfer is still 1945 in progress. On some boards it is possible to access 1946 the i2c SCLK line directly, either by using the 1947 processor pin as a GPIO or by having a second pin 1948 connected to the bus. If this option is defined a 1949 custom i2c_init_board() routine in boards/xxx/board.c 1950 is run early in the boot sequence. 1951 1952 CONFIG_SYS_I2C_BOARD_LATE_INIT 1953 1954 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 1955 defined a custom i2c_board_late_init() routine in 1956 boards/xxx/board.c is run AFTER the operations in i2c_init() 1957 is completed. This callpoint can be used to unreset i2c bus 1958 using CPU i2c controller register accesses for CPUs whose i2c 1959 controller provide such a method. It is called at the end of 1960 i2c_init() to allow i2c_init operations to setup the i2c bus 1961 controller on the CPU (e.g. setting bus speed & slave address). 1962 1963 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 1964 1965 This option enables configuration of bi_iic_fast[] flags 1966 in u-boot bd_info structure based on u-boot environment 1967 variable "i2cfast". (see also i2cfast) 1968 1969 CONFIG_I2C_MULTI_BUS 1970 1971 This option allows the use of multiple I2C buses, each of which 1972 must have a controller. At any point in time, only one bus is 1973 active. To switch to a different bus, use the 'i2c dev' command. 1974 Note that bus numbering is zero-based. 1975 1976 CONFIG_SYS_I2C_NOPROBES 1977 1978 This option specifies a list of I2C devices that will be skipped 1979 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1980 is set, specify a list of bus-device pairs. Otherwise, specify 1981 a 1D array of device addresses 1982 1983 e.g. 1984 #undef CONFIG_I2C_MULTI_BUS 1985 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1986 1987 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1988 1989 #define CONFIG_I2C_MULTI_BUS 1990 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1991 1992 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1993 1994 CONFIG_SYS_SPD_BUS_NUM 1995 1996 If defined, then this indicates the I2C bus number for DDR SPD. 1997 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1998 1999 CONFIG_SYS_RTC_BUS_NUM 2000 2001 If defined, then this indicates the I2C bus number for the RTC. 2002 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2003 2004 CONFIG_SYS_DTT_BUS_NUM 2005 2006 If defined, then this indicates the I2C bus number for the DTT. 2007 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2008 2009 CONFIG_SYS_I2C_DTT_ADDR: 2010 2011 If defined, specifies the I2C address of the DTT device. 2012 If not defined, then U-Boot uses predefined value for 2013 specified DTT device. 2014 2015 CONFIG_FSL_I2C 2016 2017 Define this option if you want to use Freescale's I2C driver in 2018 drivers/i2c/fsl_i2c.c. 2019 2020 CONFIG_I2C_MUX 2021 2022 Define this option if you have I2C devices reached over 1 .. n 2023 I2C Muxes like the pca9544a. This option addes a new I2C 2024 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a 2025 new I2C Bus to the existing I2C Busses. If you select the 2026 new Bus with "i2c dev", u-bbot sends first the commandos for 2027 the muxes to activate this new "bus". 2028 2029 CONFIG_I2C_MULTI_BUS must be also defined, to use this 2030 feature! 2031 2032 Example: 2033 Adding a new I2C Bus reached over 2 pca9544a muxes 2034 The First mux with address 70 and channel 6 2035 The Second mux with address 71 and channel 4 2036 2037 => i2c bus pca9544a:70:6:pca9544a:71:4 2038 2039 Use the "i2c bus" command without parameter, to get a list 2040 of I2C Busses with muxes: 2041 2042 => i2c bus 2043 Busses reached over muxes: 2044 Bus ID: 2 2045 reached over Mux(es): 2046 pca9544a@70 ch: 4 2047 Bus ID: 3 2048 reached over Mux(es): 2049 pca9544a@70 ch: 6 2050 pca9544a@71 ch: 4 2051 => 2052 2053 If you now switch to the new I2C Bus 3 with "i2c dev 3" 2054 u-boot first sends the command to the mux@70 to enable 2055 channel 6, and then the command to the mux@71 to enable 2056 the channel 4. 2057 2058 After that, you can use the "normal" i2c commands as 2059 usual to communicate with your I2C devices behind 2060 the 2 muxes. 2061 2062 This option is actually implemented for the bitbanging 2063 algorithm in common/soft_i2c.c and for the Hardware I2C 2064 Bus on the MPC8260. But it should be not so difficult 2065 to add this option to other architectures. 2066 2067 CONFIG_SOFT_I2C_READ_REPEATED_START 2068 2069 defining this will force the i2c_read() function in 2070 the soft_i2c driver to perform an I2C repeated start 2071 between writing the address pointer and reading the 2072 data. If this define is omitted the default behaviour 2073 of doing a stop-start sequence will be used. Most I2C 2074 devices can use either method, but some require one or 2075 the other. 2076 2077- SPI Support: CONFIG_SPI 2078 2079 Enables SPI driver (so far only tested with 2080 SPI EEPROM, also an instance works with Crystal A/D and 2081 D/As on the SACSng board) 2082 2083 CONFIG_SH_SPI 2084 2085 Enables the driver for SPI controller on SuperH. Currently 2086 only SH7757 is supported. 2087 2088 CONFIG_SPI_X 2089 2090 Enables extended (16-bit) SPI EEPROM addressing. 2091 (symmetrical to CONFIG_I2C_X) 2092 2093 CONFIG_SOFT_SPI 2094 2095 Enables a software (bit-bang) SPI driver rather than 2096 using hardware support. This is a general purpose 2097 driver that only requires three general I/O port pins 2098 (two outputs, one input) to function. If this is 2099 defined, the board configuration must define several 2100 SPI configuration items (port pins to use, etc). For 2101 an example, see include/configs/sacsng.h. 2102 2103 CONFIG_HARD_SPI 2104 2105 Enables a hardware SPI driver for general-purpose reads 2106 and writes. As with CONFIG_SOFT_SPI, the board configuration 2107 must define a list of chip-select function pointers. 2108 Currently supported on some MPC8xxx processors. For an 2109 example, see include/configs/mpc8349emds.h. 2110 2111 CONFIG_MXC_SPI 2112 2113 Enables the driver for the SPI controllers on i.MX and MXC 2114 SoCs. Currently i.MX31/35/51 are supported. 2115 2116- FPGA Support: CONFIG_FPGA 2117 2118 Enables FPGA subsystem. 2119 2120 CONFIG_FPGA_<vendor> 2121 2122 Enables support for specific chip vendors. 2123 (ALTERA, XILINX) 2124 2125 CONFIG_FPGA_<family> 2126 2127 Enables support for FPGA family. 2128 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2129 2130 CONFIG_FPGA_COUNT 2131 2132 Specify the number of FPGA devices to support. 2133 2134 CONFIG_SYS_FPGA_PROG_FEEDBACK 2135 2136 Enable printing of hash marks during FPGA configuration. 2137 2138 CONFIG_SYS_FPGA_CHECK_BUSY 2139 2140 Enable checks on FPGA configuration interface busy 2141 status by the configuration function. This option 2142 will require a board or device specific function to 2143 be written. 2144 2145 CONFIG_FPGA_DELAY 2146 2147 If defined, a function that provides delays in the FPGA 2148 configuration driver. 2149 2150 CONFIG_SYS_FPGA_CHECK_CTRLC 2151 Allow Control-C to interrupt FPGA configuration 2152 2153 CONFIG_SYS_FPGA_CHECK_ERROR 2154 2155 Check for configuration errors during FPGA bitfile 2156 loading. For example, abort during Virtex II 2157 configuration if the INIT_B line goes low (which 2158 indicated a CRC error). 2159 2160 CONFIG_SYS_FPGA_WAIT_INIT 2161 2162 Maximum time to wait for the INIT_B line to deassert 2163 after PROB_B has been deasserted during a Virtex II 2164 FPGA configuration sequence. The default time is 500 2165 ms. 2166 2167 CONFIG_SYS_FPGA_WAIT_BUSY 2168 2169 Maximum time to wait for BUSY to deassert during 2170 Virtex II FPGA configuration. The default is 5 ms. 2171 2172 CONFIG_SYS_FPGA_WAIT_CONFIG 2173 2174 Time to wait after FPGA configuration. The default is 2175 200 ms. 2176 2177- Configuration Management: 2178 CONFIG_IDENT_STRING 2179 2180 If defined, this string will be added to the U-Boot 2181 version information (U_BOOT_VERSION) 2182 2183- Vendor Parameter Protection: 2184 2185 U-Boot considers the values of the environment 2186 variables "serial#" (Board Serial Number) and 2187 "ethaddr" (Ethernet Address) to be parameters that 2188 are set once by the board vendor / manufacturer, and 2189 protects these variables from casual modification by 2190 the user. Once set, these variables are read-only, 2191 and write or delete attempts are rejected. You can 2192 change this behaviour: 2193 2194 If CONFIG_ENV_OVERWRITE is #defined in your config 2195 file, the write protection for vendor parameters is 2196 completely disabled. Anybody can change or delete 2197 these parameters. 2198 2199 Alternatively, if you #define _both_ CONFIG_ETHADDR 2200 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2201 Ethernet address is installed in the environment, 2202 which can be changed exactly ONCE by the user. [The 2203 serial# is unaffected by this, i. e. it remains 2204 read-only.] 2205 2206 The same can be accomplished in a more flexible way 2207 for any variable by configuring the type of access 2208 to allow for those variables in the ".flags" variable 2209 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2210 2211- Protected RAM: 2212 CONFIG_PRAM 2213 2214 Define this variable to enable the reservation of 2215 "protected RAM", i. e. RAM which is not overwritten 2216 by U-Boot. Define CONFIG_PRAM to hold the number of 2217 kB you want to reserve for pRAM. You can overwrite 2218 this default value by defining an environment 2219 variable "pram" to the number of kB you want to 2220 reserve. Note that the board info structure will 2221 still show the full amount of RAM. If pRAM is 2222 reserved, a new environment variable "mem" will 2223 automatically be defined to hold the amount of 2224 remaining RAM in a form that can be passed as boot 2225 argument to Linux, for instance like that: 2226 2227 setenv bootargs ... mem=\${mem} 2228 saveenv 2229 2230 This way you can tell Linux not to use this memory, 2231 either, which results in a memory region that will 2232 not be affected by reboots. 2233 2234 *WARNING* If your board configuration uses automatic 2235 detection of the RAM size, you must make sure that 2236 this memory test is non-destructive. So far, the 2237 following board configurations are known to be 2238 "pRAM-clean": 2239 2240 IVMS8, IVML24, SPD8xx, TQM8xxL, 2241 HERMES, IP860, RPXlite, LWMON, 2242 FLAGADM, TQM8260 2243 2244- Access to physical memory region (> 4GB) 2245 Some basic support is provided for operations on memory not 2246 normally accessible to U-Boot - e.g. some architectures 2247 support access to more than 4GB of memory on 32-bit 2248 machines using physical address extension or similar. 2249 Define CONFIG_PHYSMEM to access this basic support, which 2250 currently only supports clearing the memory. 2251 2252- Error Recovery: 2253 CONFIG_PANIC_HANG 2254 2255 Define this variable to stop the system in case of a 2256 fatal error, so that you have to reset it manually. 2257 This is probably NOT a good idea for an embedded 2258 system where you want the system to reboot 2259 automatically as fast as possible, but it may be 2260 useful during development since you can try to debug 2261 the conditions that lead to the situation. 2262 2263 CONFIG_NET_RETRY_COUNT 2264 2265 This variable defines the number of retries for 2266 network operations like ARP, RARP, TFTP, or BOOTP 2267 before giving up the operation. If not defined, a 2268 default value of 5 is used. 2269 2270 CONFIG_ARP_TIMEOUT 2271 2272 Timeout waiting for an ARP reply in milliseconds. 2273 2274 CONFIG_NFS_TIMEOUT 2275 2276 Timeout in milliseconds used in NFS protocol. 2277 If you encounter "ERROR: Cannot umount" in nfs command, 2278 try longer timeout such as 2279 #define CONFIG_NFS_TIMEOUT 10000UL 2280 2281- Command Interpreter: 2282 CONFIG_AUTO_COMPLETE 2283 2284 Enable auto completion of commands using TAB. 2285 2286 Note that this feature has NOT been implemented yet 2287 for the "hush" shell. 2288 2289 2290 CONFIG_SYS_HUSH_PARSER 2291 2292 Define this variable to enable the "hush" shell (from 2293 Busybox) as command line interpreter, thus enabling 2294 powerful command line syntax like 2295 if...then...else...fi conditionals or `&&' and '||' 2296 constructs ("shell scripts"). 2297 2298 If undefined, you get the old, much simpler behaviour 2299 with a somewhat smaller memory footprint. 2300 2301 2302 CONFIG_SYS_PROMPT_HUSH_PS2 2303 2304 This defines the secondary prompt string, which is 2305 printed when the command interpreter needs more input 2306 to complete a command. Usually "> ". 2307 2308 Note: 2309 2310 In the current implementation, the local variables 2311 space and global environment variables space are 2312 separated. Local variables are those you define by 2313 simply typing `name=value'. To access a local 2314 variable later on, you have write `$name' or 2315 `${name}'; to execute the contents of a variable 2316 directly type `$name' at the command prompt. 2317 2318 Global environment variables are those you use 2319 setenv/printenv to work with. To run a command stored 2320 in such a variable, you need to use the run command, 2321 and you must not use the '$' sign to access them. 2322 2323 To store commands and special characters in a 2324 variable, please use double quotation marks 2325 surrounding the whole text of the variable, instead 2326 of the backslashes before semicolons and special 2327 symbols. 2328 2329- Commandline Editing and History: 2330 CONFIG_CMDLINE_EDITING 2331 2332 Enable editing and History functions for interactive 2333 commandline input operations 2334 2335- Default Environment: 2336 CONFIG_EXTRA_ENV_SETTINGS 2337 2338 Define this to contain any number of null terminated 2339 strings (variable = value pairs) that will be part of 2340 the default environment compiled into the boot image. 2341 2342 For example, place something like this in your 2343 board's config file: 2344 2345 #define CONFIG_EXTRA_ENV_SETTINGS \ 2346 "myvar1=value1\0" \ 2347 "myvar2=value2\0" 2348 2349 Warning: This method is based on knowledge about the 2350 internal format how the environment is stored by the 2351 U-Boot code. This is NOT an official, exported 2352 interface! Although it is unlikely that this format 2353 will change soon, there is no guarantee either. 2354 You better know what you are doing here. 2355 2356 Note: overly (ab)use of the default environment is 2357 discouraged. Make sure to check other ways to preset 2358 the environment like the "source" command or the 2359 boot command first. 2360 2361 CONFIG_ENV_VARS_UBOOT_CONFIG 2362 2363 Define this in order to add variables describing the 2364 U-Boot build configuration to the default environment. 2365 These will be named arch, cpu, board, vendor, and soc. 2366 2367 Enabling this option will cause the following to be defined: 2368 2369 - CONFIG_SYS_ARCH 2370 - CONFIG_SYS_CPU 2371 - CONFIG_SYS_BOARD 2372 - CONFIG_SYS_VENDOR 2373 - CONFIG_SYS_SOC 2374 2375 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2376 2377 Define this in order to add variables describing certain 2378 run-time determined information about the hardware to the 2379 environment. These will be named board_name, board_rev. 2380 2381 CONFIG_DELAY_ENVIRONMENT 2382 2383 Normally the environment is loaded when the board is 2384 intialised so that it is available to U-Boot. This inhibits 2385 that so that the environment is not available until 2386 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2387 this is instead controlled by the value of 2388 /config/load-environment. 2389 2390- DataFlash Support: 2391 CONFIG_HAS_DATAFLASH 2392 2393 Defining this option enables DataFlash features and 2394 allows to read/write in Dataflash via the standard 2395 commands cp, md... 2396 2397- Serial Flash support 2398 CONFIG_CMD_SF 2399 2400 Defining this option enables SPI flash commands 2401 'sf probe/read/write/erase/update'. 2402 2403 Usage requires an initial 'probe' to define the serial 2404 flash parameters, followed by read/write/erase/update 2405 commands. 2406 2407 The following defaults may be provided by the platform 2408 to handle the common case when only a single serial 2409 flash is present on the system. 2410 2411 CONFIG_SF_DEFAULT_BUS Bus identifier 2412 CONFIG_SF_DEFAULT_CS Chip-select 2413 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2414 CONFIG_SF_DEFAULT_SPEED in Hz 2415 2416- SystemACE Support: 2417 CONFIG_SYSTEMACE 2418 2419 Adding this option adds support for Xilinx SystemACE 2420 chips attached via some sort of local bus. The address 2421 of the chip must also be defined in the 2422 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2423 2424 #define CONFIG_SYSTEMACE 2425 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2426 2427 When SystemACE support is added, the "ace" device type 2428 becomes available to the fat commands, i.e. fatls. 2429 2430- TFTP Fixed UDP Port: 2431 CONFIG_TFTP_PORT 2432 2433 If this is defined, the environment variable tftpsrcp 2434 is used to supply the TFTP UDP source port value. 2435 If tftpsrcp isn't defined, the normal pseudo-random port 2436 number generator is used. 2437 2438 Also, the environment variable tftpdstp is used to supply 2439 the TFTP UDP destination port value. If tftpdstp isn't 2440 defined, the normal port 69 is used. 2441 2442 The purpose for tftpsrcp is to allow a TFTP server to 2443 blindly start the TFTP transfer using the pre-configured 2444 target IP address and UDP port. This has the effect of 2445 "punching through" the (Windows XP) firewall, allowing 2446 the remainder of the TFTP transfer to proceed normally. 2447 A better solution is to properly configure the firewall, 2448 but sometimes that is not allowed. 2449 2450- Hashing support: 2451 CONFIG_CMD_HASH 2452 2453 This enables a generic 'hash' command which can produce 2454 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 2455 2456 CONFIG_HASH_VERIFY 2457 2458 Enable the hash verify command (hash -v). This adds to code 2459 size a little. 2460 2461 CONFIG_SHA1 - support SHA1 hashing 2462 CONFIG_SHA256 - support SHA256 hashing 2463 2464 Note: There is also a sha1sum command, which should perhaps 2465 be deprecated in favour of 'hash sha1'. 2466 2467- Show boot progress: 2468 CONFIG_SHOW_BOOT_PROGRESS 2469 2470 Defining this option allows to add some board- 2471 specific code (calling a user-provided function 2472 "show_boot_progress(int)") that enables you to show 2473 the system's boot progress on some display (for 2474 example, some LED's) on your board. At the moment, 2475 the following checkpoints are implemented: 2476 2477- Detailed boot stage timing 2478 CONFIG_BOOTSTAGE 2479 Define this option to get detailed timing of each stage 2480 of the boot process. 2481 2482 CONFIG_BOOTSTAGE_USER_COUNT 2483 This is the number of available user bootstage records. 2484 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...) 2485 a new ID will be allocated from this stash. If you exceed 2486 the limit, recording will stop. 2487 2488 CONFIG_BOOTSTAGE_REPORT 2489 Define this to print a report before boot, similar to this: 2490 2491 Timer summary in microseconds: 2492 Mark Elapsed Stage 2493 0 0 reset 2494 3,575,678 3,575,678 board_init_f start 2495 3,575,695 17 arch_cpu_init A9 2496 3,575,777 82 arch_cpu_init done 2497 3,659,598 83,821 board_init_r start 2498 3,910,375 250,777 main_loop 2499 29,916,167 26,005,792 bootm_start 2500 30,361,327 445,160 start_kernel 2501 2502 CONFIG_CMD_BOOTSTAGE 2503 Add a 'bootstage' command which supports printing a report 2504 and un/stashing of bootstage data. 2505 2506 CONFIG_BOOTSTAGE_FDT 2507 Stash the bootstage information in the FDT. A root 'bootstage' 2508 node is created with each bootstage id as a child. Each child 2509 has a 'name' property and either 'mark' containing the 2510 mark time in microsecond, or 'accum' containing the 2511 accumulated time for that bootstage id in microseconds. 2512 For example: 2513 2514 bootstage { 2515 154 { 2516 name = "board_init_f"; 2517 mark = <3575678>; 2518 }; 2519 170 { 2520 name = "lcd"; 2521 accum = <33482>; 2522 }; 2523 }; 2524 2525 Code in the Linux kernel can find this in /proc/devicetree. 2526 2527Legacy uImage format: 2528 2529 Arg Where When 2530 1 common/cmd_bootm.c before attempting to boot an image 2531 -1 common/cmd_bootm.c Image header has bad magic number 2532 2 common/cmd_bootm.c Image header has correct magic number 2533 -2 common/cmd_bootm.c Image header has bad checksum 2534 3 common/cmd_bootm.c Image header has correct checksum 2535 -3 common/cmd_bootm.c Image data has bad checksum 2536 4 common/cmd_bootm.c Image data has correct checksum 2537 -4 common/cmd_bootm.c Image is for unsupported architecture 2538 5 common/cmd_bootm.c Architecture check OK 2539 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2540 6 common/cmd_bootm.c Image Type check OK 2541 -6 common/cmd_bootm.c gunzip uncompression error 2542 -7 common/cmd_bootm.c Unimplemented compression type 2543 7 common/cmd_bootm.c Uncompression OK 2544 8 common/cmd_bootm.c No uncompress/copy overwrite error 2545 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2546 2547 9 common/image.c Start initial ramdisk verification 2548 -10 common/image.c Ramdisk header has bad magic number 2549 -11 common/image.c Ramdisk header has bad checksum 2550 10 common/image.c Ramdisk header is OK 2551 -12 common/image.c Ramdisk data has bad checksum 2552 11 common/image.c Ramdisk data has correct checksum 2553 12 common/image.c Ramdisk verification complete, start loading 2554 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2555 13 common/image.c Start multifile image verification 2556 14 common/image.c No initial ramdisk, no multifile, continue. 2557 2558 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2559 2560 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2561 -31 post/post.c POST test failed, detected by post_output_backlog() 2562 -32 post/post.c POST test failed, detected by post_run_single() 2563 2564 34 common/cmd_doc.c before loading a Image from a DOC device 2565 -35 common/cmd_doc.c Bad usage of "doc" command 2566 35 common/cmd_doc.c correct usage of "doc" command 2567 -36 common/cmd_doc.c No boot device 2568 36 common/cmd_doc.c correct boot device 2569 -37 common/cmd_doc.c Unknown Chip ID on boot device 2570 37 common/cmd_doc.c correct chip ID found, device available 2571 -38 common/cmd_doc.c Read Error on boot device 2572 38 common/cmd_doc.c reading Image header from DOC device OK 2573 -39 common/cmd_doc.c Image header has bad magic number 2574 39 common/cmd_doc.c Image header has correct magic number 2575 -40 common/cmd_doc.c Error reading Image from DOC device 2576 40 common/cmd_doc.c Image header has correct magic number 2577 41 common/cmd_ide.c before loading a Image from a IDE device 2578 -42 common/cmd_ide.c Bad usage of "ide" command 2579 42 common/cmd_ide.c correct usage of "ide" command 2580 -43 common/cmd_ide.c No boot device 2581 43 common/cmd_ide.c boot device found 2582 -44 common/cmd_ide.c Device not available 2583 44 common/cmd_ide.c Device available 2584 -45 common/cmd_ide.c wrong partition selected 2585 45 common/cmd_ide.c partition selected 2586 -46 common/cmd_ide.c Unknown partition table 2587 46 common/cmd_ide.c valid partition table found 2588 -47 common/cmd_ide.c Invalid partition type 2589 47 common/cmd_ide.c correct partition type 2590 -48 common/cmd_ide.c Error reading Image Header on boot device 2591 48 common/cmd_ide.c reading Image Header from IDE device OK 2592 -49 common/cmd_ide.c Image header has bad magic number 2593 49 common/cmd_ide.c Image header has correct magic number 2594 -50 common/cmd_ide.c Image header has bad checksum 2595 50 common/cmd_ide.c Image header has correct checksum 2596 -51 common/cmd_ide.c Error reading Image from IDE device 2597 51 common/cmd_ide.c reading Image from IDE device OK 2598 52 common/cmd_nand.c before loading a Image from a NAND device 2599 -53 common/cmd_nand.c Bad usage of "nand" command 2600 53 common/cmd_nand.c correct usage of "nand" command 2601 -54 common/cmd_nand.c No boot device 2602 54 common/cmd_nand.c boot device found 2603 -55 common/cmd_nand.c Unknown Chip ID on boot device 2604 55 common/cmd_nand.c correct chip ID found, device available 2605 -56 common/cmd_nand.c Error reading Image Header on boot device 2606 56 common/cmd_nand.c reading Image Header from NAND device OK 2607 -57 common/cmd_nand.c Image header has bad magic number 2608 57 common/cmd_nand.c Image header has correct magic number 2609 -58 common/cmd_nand.c Error reading Image from NAND device 2610 58 common/cmd_nand.c reading Image from NAND device OK 2611 2612 -60 common/env_common.c Environment has a bad CRC, using default 2613 2614 64 net/eth.c starting with Ethernet configuration. 2615 -64 net/eth.c no Ethernet found. 2616 65 net/eth.c Ethernet found. 2617 2618 -80 common/cmd_net.c usage wrong 2619 80 common/cmd_net.c before calling NetLoop() 2620 -81 common/cmd_net.c some error in NetLoop() occurred 2621 81 common/cmd_net.c NetLoop() back without error 2622 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2623 82 common/cmd_net.c trying automatic boot 2624 83 common/cmd_net.c running "source" command 2625 -83 common/cmd_net.c some error in automatic boot or "source" command 2626 84 common/cmd_net.c end without errors 2627 2628FIT uImage format: 2629 2630 Arg Where When 2631 100 common/cmd_bootm.c Kernel FIT Image has correct format 2632 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2633 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2634 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2635 102 common/cmd_bootm.c Kernel unit name specified 2636 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2637 103 common/cmd_bootm.c Found configuration node 2638 104 common/cmd_bootm.c Got kernel subimage node offset 2639 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2640 105 common/cmd_bootm.c Kernel subimage hash verification OK 2641 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2642 106 common/cmd_bootm.c Architecture check OK 2643 -106 common/cmd_bootm.c Kernel subimage has wrong type 2644 107 common/cmd_bootm.c Kernel subimage type OK 2645 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2646 108 common/cmd_bootm.c Got kernel subimage data/size 2647 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2648 -109 common/cmd_bootm.c Can't get kernel subimage type 2649 -110 common/cmd_bootm.c Can't get kernel subimage comp 2650 -111 common/cmd_bootm.c Can't get kernel subimage os 2651 -112 common/cmd_bootm.c Can't get kernel subimage load address 2652 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2653 2654 120 common/image.c Start initial ramdisk verification 2655 -120 common/image.c Ramdisk FIT image has incorrect format 2656 121 common/image.c Ramdisk FIT image has correct format 2657 122 common/image.c No ramdisk subimage unit name, using configuration 2658 -122 common/image.c Can't get configuration for ramdisk subimage 2659 123 common/image.c Ramdisk unit name specified 2660 -124 common/image.c Can't get ramdisk subimage node offset 2661 125 common/image.c Got ramdisk subimage node offset 2662 -125 common/image.c Ramdisk subimage hash verification failed 2663 126 common/image.c Ramdisk subimage hash verification OK 2664 -126 common/image.c Ramdisk subimage for unsupported architecture 2665 127 common/image.c Architecture check OK 2666 -127 common/image.c Can't get ramdisk subimage data/size 2667 128 common/image.c Got ramdisk subimage data/size 2668 129 common/image.c Can't get ramdisk load address 2669 -129 common/image.c Got ramdisk load address 2670 2671 -130 common/cmd_doc.c Incorrect FIT image format 2672 131 common/cmd_doc.c FIT image format OK 2673 2674 -140 common/cmd_ide.c Incorrect FIT image format 2675 141 common/cmd_ide.c FIT image format OK 2676 2677 -150 common/cmd_nand.c Incorrect FIT image format 2678 151 common/cmd_nand.c FIT image format OK 2679 2680- FIT image support: 2681 CONFIG_FIT 2682 Enable support for the FIT uImage format. 2683 2684 CONFIG_FIT_BEST_MATCH 2685 When no configuration is explicitly selected, default to the 2686 one whose fdt's compatibility field best matches that of 2687 U-Boot itself. A match is considered "best" if it matches the 2688 most specific compatibility entry of U-Boot's fdt's root node. 2689 The order of entries in the configuration's fdt is ignored. 2690 2691- Standalone program support: 2692 CONFIG_STANDALONE_LOAD_ADDR 2693 2694 This option defines a board specific value for the 2695 address where standalone program gets loaded, thus 2696 overwriting the architecture dependent default 2697 settings. 2698 2699- Frame Buffer Address: 2700 CONFIG_FB_ADDR 2701 2702 Define CONFIG_FB_ADDR if you want to use specific 2703 address for frame buffer. 2704 Then system will reserve the frame buffer address to 2705 defined address instead of lcd_setmem (this function 2706 grabs the memory for frame buffer by panel's size). 2707 2708 Please see board_init_f function. 2709 2710- Automatic software updates via TFTP server 2711 CONFIG_UPDATE_TFTP 2712 CONFIG_UPDATE_TFTP_CNT_MAX 2713 CONFIG_UPDATE_TFTP_MSEC_MAX 2714 2715 These options enable and control the auto-update feature; 2716 for a more detailed description refer to doc/README.update. 2717 2718- MTD Support (mtdparts command, UBI support) 2719 CONFIG_MTD_DEVICE 2720 2721 Adds the MTD device infrastructure from the Linux kernel. 2722 Needed for mtdparts command support. 2723 2724 CONFIG_MTD_PARTITIONS 2725 2726 Adds the MTD partitioning infrastructure from the Linux 2727 kernel. Needed for UBI support. 2728 2729- SPL framework 2730 CONFIG_SPL 2731 Enable building of SPL globally. 2732 2733 CONFIG_SPL_LDSCRIPT 2734 LDSCRIPT for linking the SPL binary. 2735 2736 CONFIG_SPL_MAX_SIZE 2737 Maximum binary size (text, data and rodata) of the SPL binary. 2738 2739 CONFIG_SPL_TEXT_BASE 2740 TEXT_BASE for linking the SPL binary. 2741 2742 CONFIG_SPL_RELOC_TEXT_BASE 2743 Address to relocate to. If unspecified, this is equal to 2744 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2745 2746 CONFIG_SPL_BSS_START_ADDR 2747 Link address for the BSS within the SPL binary. 2748 2749 CONFIG_SPL_BSS_MAX_SIZE 2750 Maximum binary size of the BSS section of the SPL binary. 2751 2752 CONFIG_SPL_STACK 2753 Adress of the start of the stack SPL will use 2754 2755 CONFIG_SPL_RELOC_STACK 2756 Adress of the start of the stack SPL will use after 2757 relocation. If unspecified, this is equal to 2758 CONFIG_SPL_STACK. 2759 2760 CONFIG_SYS_SPL_MALLOC_START 2761 Starting address of the malloc pool used in SPL. 2762 2763 CONFIG_SYS_SPL_MALLOC_SIZE 2764 The size of the malloc pool used in SPL. 2765 2766 CONFIG_SPL_FRAMEWORK 2767 Enable the SPL framework under common/. This framework 2768 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2769 NAND loading of the Linux Kernel. 2770 2771 CONFIG_SPL_DISPLAY_PRINT 2772 For ARM, enable an optional function to print more information 2773 about the running system. 2774 2775 CONFIG_SPL_INIT_MINIMAL 2776 Arch init code should be built for a very small image 2777 2778 CONFIG_SPL_LIBCOMMON_SUPPORT 2779 Support for common/libcommon.o in SPL binary 2780 2781 CONFIG_SPL_LIBDISK_SUPPORT 2782 Support for disk/libdisk.o in SPL binary 2783 2784 CONFIG_SPL_I2C_SUPPORT 2785 Support for drivers/i2c/libi2c.o in SPL binary 2786 2787 CONFIG_SPL_GPIO_SUPPORT 2788 Support for drivers/gpio/libgpio.o in SPL binary 2789 2790 CONFIG_SPL_MMC_SUPPORT 2791 Support for drivers/mmc/libmmc.o in SPL binary 2792 2793 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, 2794 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS, 2795 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION 2796 Address, size and partition on the MMC to load U-Boot from 2797 when the MMC is being used in raw mode. 2798 2799 CONFIG_SPL_FAT_SUPPORT 2800 Support for fs/fat/libfat.o in SPL binary 2801 2802 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME 2803 Filename to read to load U-Boot when reading from FAT 2804 2805 CONFIG_SPL_NAND_BASE 2806 Include nand_base.c in the SPL. Requires 2807 CONFIG_SPL_NAND_DRIVERS. 2808 2809 CONFIG_SPL_NAND_DRIVERS 2810 SPL uses normal NAND drivers, not minimal drivers. 2811 2812 CONFIG_SPL_NAND_ECC 2813 Include standard software ECC in the SPL 2814 2815 CONFIG_SPL_NAND_SIMPLE 2816 Support for NAND boot using simple NAND drivers that 2817 expose the cmd_ctrl() interface. 2818 2819 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2820 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2821 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2822 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2823 CONFIG_SYS_NAND_ECCBYTES 2824 Defines the size and behavior of the NAND that SPL uses 2825 to read U-Boot 2826 2827 CONFIG_SYS_NAND_U_BOOT_OFFS 2828 Location in NAND to read U-Boot from 2829 2830 CONFIG_SYS_NAND_U_BOOT_DST 2831 Location in memory to load U-Boot to 2832 2833 CONFIG_SYS_NAND_U_BOOT_SIZE 2834 Size of image to load 2835 2836 CONFIG_SYS_NAND_U_BOOT_START 2837 Entry point in loaded image to jump to 2838 2839 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2840 Define this if you need to first read the OOB and then the 2841 data. This is used for example on davinci plattforms. 2842 2843 CONFIG_SPL_OMAP3_ID_NAND 2844 Support for an OMAP3-specific set of functions to return the 2845 ID and MFR of the first attached NAND chip, if present. 2846 2847 CONFIG_SPL_SERIAL_SUPPORT 2848 Support for drivers/serial/libserial.o in SPL binary 2849 2850 CONFIG_SPL_SPI_FLASH_SUPPORT 2851 Support for drivers/mtd/spi/libspi_flash.o in SPL binary 2852 2853 CONFIG_SPL_SPI_SUPPORT 2854 Support for drivers/spi/libspi.o in SPL binary 2855 2856 CONFIG_SPL_RAM_DEVICE 2857 Support for running image already present in ram, in SPL binary 2858 2859 CONFIG_SPL_LIBGENERIC_SUPPORT 2860 Support for lib/libgeneric.o in SPL binary 2861 2862 CONFIG_SPL_TARGET 2863 Final target image containing SPL and payload. Some SPLs 2864 use an arch-specific makefile fragment instead, for 2865 example if more than one image needs to be produced. 2866 2867Modem Support: 2868-------------- 2869 2870[so far only for SMDK2400 boards] 2871 2872- Modem support enable: 2873 CONFIG_MODEM_SUPPORT 2874 2875- RTS/CTS Flow control enable: 2876 CONFIG_HWFLOW 2877 2878- Modem debug support: 2879 CONFIG_MODEM_SUPPORT_DEBUG 2880 2881 Enables debugging stuff (char screen[1024], dbg()) 2882 for modem support. Useful only with BDI2000. 2883 2884- Interrupt support (PPC): 2885 2886 There are common interrupt_init() and timer_interrupt() 2887 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2888 for CPU specific initialization. interrupt_init_cpu() 2889 should set decrementer_count to appropriate value. If 2890 CPU resets decrementer automatically after interrupt 2891 (ppc4xx) it should set decrementer_count to zero. 2892 timer_interrupt() calls timer_interrupt_cpu() for CPU 2893 specific handling. If board has watchdog / status_led 2894 / other_activity_monitor it works automatically from 2895 general timer_interrupt(). 2896 2897- General: 2898 2899 In the target system modem support is enabled when a 2900 specific key (key combination) is pressed during 2901 power-on. Otherwise U-Boot will boot normally 2902 (autoboot). The key_pressed() function is called from 2903 board_init(). Currently key_pressed() is a dummy 2904 function, returning 1 and thus enabling modem 2905 initialization. 2906 2907 If there are no modem init strings in the 2908 environment, U-Boot proceed to autoboot; the 2909 previous output (banner, info printfs) will be 2910 suppressed, though. 2911 2912 See also: doc/README.Modem 2913 2914Board initialization settings: 2915------------------------------ 2916 2917During Initialization u-boot calls a number of board specific functions 2918to allow the preparation of board specific prerequisites, e.g. pin setup 2919before drivers are initialized. To enable these callbacks the 2920following configuration macros have to be defined. Currently this is 2921architecture specific, so please check arch/your_architecture/lib/board.c 2922typically in board_init_f() and board_init_r(). 2923 2924- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2925- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2926- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2927- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2928 2929Configuration Settings: 2930----------------------- 2931 2932- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2933 undefine this when you're short of memory. 2934 2935- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2936 width of the commands listed in the 'help' command output. 2937 2938- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2939 prompt for user input. 2940 2941- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2942 2943- CONFIG_SYS_PBSIZE: Buffer size for Console output 2944 2945- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2946 2947- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2948 the application (usually a Linux kernel) when it is 2949 booted 2950 2951- CONFIG_SYS_BAUDRATE_TABLE: 2952 List of legal baudrate settings for this board. 2953 2954- CONFIG_SYS_CONSOLE_INFO_QUIET 2955 Suppress display of console information at boot. 2956 2957- CONFIG_SYS_CONSOLE_IS_IN_ENV 2958 If the board specific function 2959 extern int overwrite_console (void); 2960 returns 1, the stdin, stderr and stdout are switched to the 2961 serial port, else the settings in the environment are used. 2962 2963- CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE 2964 Enable the call to overwrite_console(). 2965 2966- CONFIG_SYS_CONSOLE_ENV_OVERWRITE 2967 Enable overwrite of previous console environment settings. 2968 2969- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2970 Begin and End addresses of the area used by the 2971 simple memory test. 2972 2973- CONFIG_SYS_ALT_MEMTEST: 2974 Enable an alternate, more extensive memory test. 2975 2976- CONFIG_SYS_MEMTEST_SCRATCH: 2977 Scratch address used by the alternate memory test 2978 You only need to set this if address zero isn't writeable 2979 2980- CONFIG_SYS_MEM_TOP_HIDE (PPC only): 2981 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2982 this specified memory area will get subtracted from the top 2983 (end) of RAM and won't get "touched" at all by U-Boot. By 2984 fixing up gd->ram_size the Linux kernel should gets passed 2985 the now "corrected" memory size and won't touch it either. 2986 This should work for arch/ppc and arch/powerpc. Only Linux 2987 board ports in arch/powerpc with bootwrapper support that 2988 recalculate the memory size from the SDRAM controller setup 2989 will have to get fixed in Linux additionally. 2990 2991 This option can be used as a workaround for the 440EPx/GRx 2992 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2993 be touched. 2994 2995 WARNING: Please make sure that this value is a multiple of 2996 the Linux page size (normally 4k). If this is not the case, 2997 then the end address of the Linux memory will be located at a 2998 non page size aligned address and this could cause major 2999 problems. 3000 3001- CONFIG_SYS_LOADS_BAUD_CHANGE: 3002 Enable temporary baudrate change while serial download 3003 3004- CONFIG_SYS_SDRAM_BASE: 3005 Physical start address of SDRAM. _Must_ be 0 here. 3006 3007- CONFIG_SYS_MBIO_BASE: 3008 Physical start address of Motherboard I/O (if using a 3009 Cogent motherboard) 3010 3011- CONFIG_SYS_FLASH_BASE: 3012 Physical start address of Flash memory. 3013 3014- CONFIG_SYS_MONITOR_BASE: 3015 Physical start address of boot monitor code (set by 3016 make config files to be same as the text base address 3017 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3018 CONFIG_SYS_FLASH_BASE when booting from flash. 3019 3020- CONFIG_SYS_MONITOR_LEN: 3021 Size of memory reserved for monitor code, used to 3022 determine _at_compile_time_ (!) if the environment is 3023 embedded within the U-Boot image, or in a separate 3024 flash sector. 3025 3026- CONFIG_SYS_MALLOC_LEN: 3027 Size of DRAM reserved for malloc() use. 3028 3029- CONFIG_SYS_BOOTM_LEN: 3030 Normally compressed uImages are limited to an 3031 uncompressed size of 8 MBytes. If this is not enough, 3032 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3033 to adjust this setting to your needs. 3034 3035- CONFIG_SYS_BOOTMAPSZ: 3036 Maximum size of memory mapped by the startup code of 3037 the Linux kernel; all data that must be processed by 3038 the Linux kernel (bd_info, boot arguments, FDT blob if 3039 used) must be put below this limit, unless "bootm_low" 3040 enviroment variable is defined and non-zero. In such case 3041 all data for the Linux kernel must be between "bootm_low" 3042 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3043 variable "bootm_mapsize" will override the value of 3044 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3045 then the value in "bootm_size" will be used instead. 3046 3047- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3048 Enable initrd_high functionality. If defined then the 3049 initrd_high feature is enabled and the bootm ramdisk subcommand 3050 is enabled. 3051 3052- CONFIG_SYS_BOOT_GET_CMDLINE: 3053 Enables allocating and saving kernel cmdline in space between 3054 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3055 3056- CONFIG_SYS_BOOT_GET_KBD: 3057 Enables allocating and saving a kernel copy of the bd_info in 3058 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3059 3060- CONFIG_SYS_MAX_FLASH_BANKS: 3061 Max number of Flash memory banks 3062 3063- CONFIG_SYS_MAX_FLASH_SECT: 3064 Max number of sectors on a Flash chip 3065 3066- CONFIG_SYS_FLASH_ERASE_TOUT: 3067 Timeout for Flash erase operations (in ms) 3068 3069- CONFIG_SYS_FLASH_WRITE_TOUT: 3070 Timeout for Flash write operations (in ms) 3071 3072- CONFIG_SYS_FLASH_LOCK_TOUT 3073 Timeout for Flash set sector lock bit operation (in ms) 3074 3075- CONFIG_SYS_FLASH_UNLOCK_TOUT 3076 Timeout for Flash clear lock bits operation (in ms) 3077 3078- CONFIG_SYS_FLASH_PROTECTION 3079 If defined, hardware flash sectors protection is used 3080 instead of U-Boot software protection. 3081 3082- CONFIG_SYS_DIRECT_FLASH_TFTP: 3083 3084 Enable TFTP transfers directly to flash memory; 3085 without this option such a download has to be 3086 performed in two steps: (1) download to RAM, and (2) 3087 copy from RAM to flash. 3088 3089 The two-step approach is usually more reliable, since 3090 you can check if the download worked before you erase 3091 the flash, but in some situations (when system RAM is 3092 too limited to allow for a temporary copy of the 3093 downloaded image) this option may be very useful. 3094 3095- CONFIG_SYS_FLASH_CFI: 3096 Define if the flash driver uses extra elements in the 3097 common flash structure for storing flash geometry. 3098 3099- CONFIG_FLASH_CFI_DRIVER 3100 This option also enables the building of the cfi_flash driver 3101 in the drivers directory 3102 3103- CONFIG_FLASH_CFI_MTD 3104 This option enables the building of the cfi_mtd driver 3105 in the drivers directory. The driver exports CFI flash 3106 to the MTD layer. 3107 3108- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3109 Use buffered writes to flash. 3110 3111- CONFIG_FLASH_SPANSION_S29WS_N 3112 s29ws-n MirrorBit flash has non-standard addresses for buffered 3113 write commands. 3114 3115- CONFIG_SYS_FLASH_QUIET_TEST 3116 If this option is defined, the common CFI flash doesn't 3117 print it's warning upon not recognized FLASH banks. This 3118 is useful, if some of the configured banks are only 3119 optionally available. 3120 3121- CONFIG_FLASH_SHOW_PROGRESS 3122 If defined (must be an integer), print out countdown 3123 digits and dots. Recommended value: 45 (9..1) for 80 3124 column displays, 15 (3..1) for 40 column displays. 3125 3126- CONFIG_SYS_RX_ETH_BUFFER: 3127 Defines the number of Ethernet receive buffers. On some 3128 Ethernet controllers it is recommended to set this value 3129 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3130 buffers can be full shortly after enabling the interface 3131 on high Ethernet traffic. 3132 Defaults to 4 if not defined. 3133 3134- CONFIG_ENV_MAX_ENTRIES 3135 3136 Maximum number of entries in the hash table that is used 3137 internally to store the environment settings. The default 3138 setting is supposed to be generous and should work in most 3139 cases. This setting can be used to tune behaviour; see 3140 lib/hashtable.c for details. 3141 3142- CONFIG_ENV_FLAGS_LIST_DEFAULT 3143- CONFIG_ENV_FLAGS_LIST_STATIC 3144 Enable validation of the values given to enviroment variables when 3145 calling env set. Variables can be restricted to only decimal, 3146 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3147 the variables can also be restricted to IP address or MAC address. 3148 3149 The format of the list is: 3150 type_attribute = [s|d|x|b|i|m] 3151 access_atribute = [a|r|o|c] 3152 attributes = type_attribute[access_atribute] 3153 entry = variable_name[:attributes] 3154 list = entry[,list] 3155 3156 The type attributes are: 3157 s - String (default) 3158 d - Decimal 3159 x - Hexadecimal 3160 b - Boolean ([1yYtT|0nNfF]) 3161 i - IP address 3162 m - MAC address 3163 3164 The access attributes are: 3165 a - Any (default) 3166 r - Read-only 3167 o - Write-once 3168 c - Change-default 3169 3170 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3171 Define this to a list (string) to define the ".flags" 3172 envirnoment variable in the default or embedded environment. 3173 3174 - CONFIG_ENV_FLAGS_LIST_STATIC 3175 Define this to a list (string) to define validation that 3176 should be done if an entry is not found in the ".flags" 3177 environment variable. To override a setting in the static 3178 list, simply add an entry for the same variable name to the 3179 ".flags" variable. 3180 3181- CONFIG_ENV_ACCESS_IGNORE_FORCE 3182 If defined, don't allow the -f switch to env set override variable 3183 access flags. 3184 3185The following definitions that deal with the placement and management 3186of environment data (variable area); in general, we support the 3187following configurations: 3188 3189- CONFIG_BUILD_ENVCRC: 3190 3191 Builds up envcrc with the target environment so that external utils 3192 may easily extract it and embed it in final U-Boot images. 3193 3194- CONFIG_ENV_IS_IN_FLASH: 3195 3196 Define this if the environment is in flash memory. 3197 3198 a) The environment occupies one whole flash sector, which is 3199 "embedded" in the text segment with the U-Boot code. This 3200 happens usually with "bottom boot sector" or "top boot 3201 sector" type flash chips, which have several smaller 3202 sectors at the start or the end. For instance, such a 3203 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3204 such a case you would place the environment in one of the 3205 4 kB sectors - with U-Boot code before and after it. With 3206 "top boot sector" type flash chips, you would put the 3207 environment in one of the last sectors, leaving a gap 3208 between U-Boot and the environment. 3209 3210 - CONFIG_ENV_OFFSET: 3211 3212 Offset of environment data (variable area) to the 3213 beginning of flash memory; for instance, with bottom boot 3214 type flash chips the second sector can be used: the offset 3215 for this sector is given here. 3216 3217 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3218 3219 - CONFIG_ENV_ADDR: 3220 3221 This is just another way to specify the start address of 3222 the flash sector containing the environment (instead of 3223 CONFIG_ENV_OFFSET). 3224 3225 - CONFIG_ENV_SECT_SIZE: 3226 3227 Size of the sector containing the environment. 3228 3229 3230 b) Sometimes flash chips have few, equal sized, BIG sectors. 3231 In such a case you don't want to spend a whole sector for 3232 the environment. 3233 3234 - CONFIG_ENV_SIZE: 3235 3236 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3237 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3238 of this flash sector for the environment. This saves 3239 memory for the RAM copy of the environment. 3240 3241 It may also save flash memory if you decide to use this 3242 when your environment is "embedded" within U-Boot code, 3243 since then the remainder of the flash sector could be used 3244 for U-Boot code. It should be pointed out that this is 3245 STRONGLY DISCOURAGED from a robustness point of view: 3246 updating the environment in flash makes it always 3247 necessary to erase the WHOLE sector. If something goes 3248 wrong before the contents has been restored from a copy in 3249 RAM, your target system will be dead. 3250 3251 - CONFIG_ENV_ADDR_REDUND 3252 CONFIG_ENV_SIZE_REDUND 3253 3254 These settings describe a second storage area used to hold 3255 a redundant copy of the environment data, so that there is 3256 a valid backup copy in case there is a power failure during 3257 a "saveenv" operation. 3258 3259BE CAREFUL! Any changes to the flash layout, and some changes to the 3260source code will make it necessary to adapt <board>/u-boot.lds* 3261accordingly! 3262 3263 3264- CONFIG_ENV_IS_IN_NVRAM: 3265 3266 Define this if you have some non-volatile memory device 3267 (NVRAM, battery buffered SRAM) which you want to use for the 3268 environment. 3269 3270 - CONFIG_ENV_ADDR: 3271 - CONFIG_ENV_SIZE: 3272 3273 These two #defines are used to determine the memory area you 3274 want to use for environment. It is assumed that this memory 3275 can just be read and written to, without any special 3276 provision. 3277 3278BE CAREFUL! The first access to the environment happens quite early 3279in U-Boot initalization (when we try to get the setting of for the 3280console baudrate). You *MUST* have mapped your NVRAM area then, or 3281U-Boot will hang. 3282 3283Please note that even with NVRAM we still use a copy of the 3284environment in RAM: we could work on NVRAM directly, but we want to 3285keep settings there always unmodified except somebody uses "saveenv" 3286to save the current settings. 3287 3288 3289- CONFIG_ENV_IS_IN_EEPROM: 3290 3291 Use this if you have an EEPROM or similar serial access 3292 device and a driver for it. 3293 3294 - CONFIG_ENV_OFFSET: 3295 - CONFIG_ENV_SIZE: 3296 3297 These two #defines specify the offset and size of the 3298 environment area within the total memory of your EEPROM. 3299 3300 - CONFIG_SYS_I2C_EEPROM_ADDR: 3301 If defined, specified the chip address of the EEPROM device. 3302 The default address is zero. 3303 3304 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3305 If defined, the number of bits used to address bytes in a 3306 single page in the EEPROM device. A 64 byte page, for example 3307 would require six bits. 3308 3309 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3310 If defined, the number of milliseconds to delay between 3311 page writes. The default is zero milliseconds. 3312 3313 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3314 The length in bytes of the EEPROM memory array address. Note 3315 that this is NOT the chip address length! 3316 3317 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3318 EEPROM chips that implement "address overflow" are ones 3319 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3320 address and the extra bits end up in the "chip address" bit 3321 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3322 byte chips. 3323 3324 Note that we consider the length of the address field to 3325 still be one byte because the extra address bits are hidden 3326 in the chip address. 3327 3328 - CONFIG_SYS_EEPROM_SIZE: 3329 The size in bytes of the EEPROM device. 3330 3331 - CONFIG_ENV_EEPROM_IS_ON_I2C 3332 define this, if you have I2C and SPI activated, and your 3333 EEPROM, which holds the environment, is on the I2C bus. 3334 3335 - CONFIG_I2C_ENV_EEPROM_BUS 3336 if you have an Environment on an EEPROM reached over 3337 I2C muxes, you can define here, how to reach this 3338 EEPROM. For example: 3339 3340 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0" 3341 3342 EEPROM which holds the environment, is reached over 3343 a pca9547 i2c mux with address 0x70, channel 3. 3344 3345- CONFIG_ENV_IS_IN_DATAFLASH: 3346 3347 Define this if you have a DataFlash memory device which you 3348 want to use for the environment. 3349 3350 - CONFIG_ENV_OFFSET: 3351 - CONFIG_ENV_ADDR: 3352 - CONFIG_ENV_SIZE: 3353 3354 These three #defines specify the offset and size of the 3355 environment area within the total memory of your DataFlash placed 3356 at the specified address. 3357 3358- CONFIG_ENV_IS_IN_REMOTE: 3359 3360 Define this if you have a remote memory space which you 3361 want to use for the local device's environment. 3362 3363 - CONFIG_ENV_ADDR: 3364 - CONFIG_ENV_SIZE: 3365 3366 These two #defines specify the address and size of the 3367 environment area within the remote memory space. The 3368 local device can get the environment from remote memory 3369 space by SRIO or PCIE links. 3370 3371BE CAREFUL! For some special cases, the local device can not use 3372"saveenv" command. For example, the local device will get the 3373environment stored in a remote NOR flash by SRIO or PCIE link, 3374but it can not erase, write this NOR flash by SRIO or PCIE interface. 3375 3376- CONFIG_ENV_IS_IN_NAND: 3377 3378 Define this if you have a NAND device which you want to use 3379 for the environment. 3380 3381 - CONFIG_ENV_OFFSET: 3382 - CONFIG_ENV_SIZE: 3383 3384 These two #defines specify the offset and size of the environment 3385 area within the first NAND device. CONFIG_ENV_OFFSET must be 3386 aligned to an erase block boundary. 3387 3388 - CONFIG_ENV_OFFSET_REDUND (optional): 3389 3390 This setting describes a second storage area of CONFIG_ENV_SIZE 3391 size used to hold a redundant copy of the environment data, so 3392 that there is a valid backup copy in case there is a power failure 3393 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be 3394 aligned to an erase block boundary. 3395 3396 - CONFIG_ENV_RANGE (optional): 3397 3398 Specifies the length of the region in which the environment 3399 can be written. This should be a multiple of the NAND device's 3400 block size. Specifying a range with more erase blocks than 3401 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3402 the range to be avoided. 3403 3404 - CONFIG_ENV_OFFSET_OOB (optional): 3405 3406 Enables support for dynamically retrieving the offset of the 3407 environment from block zero's out-of-band data. The 3408 "nand env.oob" command can be used to record this offset. 3409 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3410 using CONFIG_ENV_OFFSET_OOB. 3411 3412- CONFIG_NAND_ENV_DST 3413 3414 Defines address in RAM to which the nand_spl code should copy the 3415 environment. If redundant environment is used, it will be copied to 3416 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3417 3418- CONFIG_SYS_SPI_INIT_OFFSET 3419 3420 Defines offset to the initial SPI buffer area in DPRAM. The 3421 area is used at an early stage (ROM part) if the environment 3422 is configured to reside in the SPI EEPROM: We need a 520 byte 3423 scratch DPRAM area. It is used between the two initialization 3424 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 3425 to be a good choice since it makes it far enough from the 3426 start of the data area as well as from the stack pointer. 3427 3428Please note that the environment is read-only until the monitor 3429has been relocated to RAM and a RAM copy of the environment has been 3430created; also, when using EEPROM you will have to use getenv_f() 3431until then to read environment variables. 3432 3433The environment is protected by a CRC32 checksum. Before the monitor 3434is relocated into RAM, as a result of a bad CRC you will be working 3435with the compiled-in default environment - *silently*!!! [This is 3436necessary, because the first environment variable we need is the 3437"baudrate" setting for the console - if we have a bad CRC, we don't 3438have any device yet where we could complain.] 3439 3440Note: once the monitor has been relocated, then it will complain if 3441the default environment is used; a new CRC is computed as soon as you 3442use the "saveenv" command to store a valid environment. 3443 3444- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3445 Echo the inverted Ethernet link state to the fault LED. 3446 3447 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3448 also needs to be defined. 3449 3450- CONFIG_SYS_FAULT_MII_ADDR: 3451 MII address of the PHY to check for the Ethernet link state. 3452 3453- CONFIG_NS16550_MIN_FUNCTIONS: 3454 Define this if you desire to only have use of the NS16550_init 3455 and NS16550_putc functions for the serial driver located at 3456 drivers/serial/ns16550.c. This option is useful for saving 3457 space for already greatly restricted images, including but not 3458 limited to NAND_SPL configurations. 3459 3460- CONFIG_DISPLAY_BOARDINFO 3461 Display information about the board that U-Boot is running on 3462 when U-Boot starts up. The board function checkboard() is called 3463 to do this. 3464 3465Low Level (hardware related) configuration options: 3466--------------------------------------------------- 3467 3468- CONFIG_SYS_CACHELINE_SIZE: 3469 Cache Line Size of the CPU. 3470 3471- CONFIG_SYS_DEFAULT_IMMR: 3472 Default address of the IMMR after system reset. 3473 3474 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 3475 and RPXsuper) to be able to adjust the position of 3476 the IMMR register after a reset. 3477 3478- CONFIG_SYS_CCSRBAR_DEFAULT: 3479 Default (power-on reset) physical address of CCSR on Freescale 3480 PowerPC SOCs. 3481 3482- CONFIG_SYS_CCSRBAR: 3483 Virtual address of CCSR. On a 32-bit build, this is typically 3484 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3485 3486 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 3487 for cross-platform code that uses that macro instead. 3488 3489- CONFIG_SYS_CCSRBAR_PHYS: 3490 Physical address of CCSR. CCSR can be relocated to a new 3491 physical address, if desired. In this case, this macro should 3492 be set to that address. Otherwise, it should be set to the 3493 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3494 is typically relocated on 36-bit builds. It is recommended 3495 that this macro be defined via the _HIGH and _LOW macros: 3496 3497 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3498 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3499 3500- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3501 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3502 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3503 used in assembly code, so it must not contain typecasts or 3504 integer size suffixes (e.g. "ULL"). 3505 3506- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3507 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3508 used in assembly code, so it must not contain typecasts or 3509 integer size suffixes (e.g. "ULL"). 3510 3511- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3512 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3513 forced to a value that ensures that CCSR is not relocated. 3514 3515- Floppy Disk Support: 3516 CONFIG_SYS_FDC_DRIVE_NUMBER 3517 3518 the default drive number (default value 0) 3519 3520 CONFIG_SYS_ISA_IO_STRIDE 3521 3522 defines the spacing between FDC chipset registers 3523 (default value 1) 3524 3525 CONFIG_SYS_ISA_IO_OFFSET 3526 3527 defines the offset of register from address. It 3528 depends on which part of the data bus is connected to 3529 the FDC chipset. (default value 0) 3530 3531 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3532 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3533 default value. 3534 3535 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3536 fdc_hw_init() is called at the beginning of the FDC 3537 setup. fdc_hw_init() must be provided by the board 3538 source code. It is used to make hardware dependant 3539 initializations. 3540 3541- CONFIG_IDE_AHB: 3542 Most IDE controllers were designed to be connected with PCI 3543 interface. Only few of them were designed for AHB interface. 3544 When software is doing ATA command and data transfer to 3545 IDE devices through IDE-AHB controller, some additional 3546 registers accessing to these kind of IDE-AHB controller 3547 is requierd. 3548 3549- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3550 DO NOT CHANGE unless you know exactly what you're 3551 doing! (11-4) [MPC8xx/82xx systems only] 3552 3553- CONFIG_SYS_INIT_RAM_ADDR: 3554 3555 Start address of memory area that can be used for 3556 initial data and stack; please note that this must be 3557 writable memory that is working WITHOUT special 3558 initialization, i. e. you CANNOT use normal RAM which 3559 will become available only after programming the 3560 memory controller and running certain initialization 3561 sequences. 3562 3563 U-Boot uses the following memory types: 3564 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 3565 - MPC824X: data cache 3566 - PPC4xx: data cache 3567 3568- CONFIG_SYS_GBL_DATA_OFFSET: 3569 3570 Offset of the initial data structure in the memory 3571 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3572 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3573 data is located at the end of the available space 3574 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3575 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just 3576 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3577 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3578 3579 Note: 3580 On the MPC824X (or other systems that use the data 3581 cache for initial memory) the address chosen for 3582 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3583 point to an otherwise UNUSED address space between 3584 the top of RAM and the start of the PCI space. 3585 3586- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 3587 3588- CONFIG_SYS_SYPCR: System Protection Control (11-9) 3589 3590- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 3591 3592- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 3593 3594- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 3595 3596- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3597 3598- CONFIG_SYS_OR_TIMING_SDRAM: 3599 SDRAM timing 3600 3601- CONFIG_SYS_MAMR_PTA: 3602 periodic timer for refresh 3603 3604- CONFIG_SYS_DER: Debug Event Register (37-47) 3605 3606- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3607 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3608 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3609 CONFIG_SYS_BR1_PRELIM: 3610 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3611 3612- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3613 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3614 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3615 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3616 3617- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 3618 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 3619 Machine Mode Register and Memory Periodic Timer 3620 Prescaler definitions (SDRAM timing) 3621 3622- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 3623 enable I2C microcode relocation patch (MPC8xx); 3624 define relocation offset in DPRAM [DSP2] 3625 3626- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 3627 enable SMC microcode relocation patch (MPC8xx); 3628 define relocation offset in DPRAM [SMC1] 3629 3630- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 3631 enable SPI microcode relocation patch (MPC8xx); 3632 define relocation offset in DPRAM [SCC4] 3633 3634- CONFIG_SYS_USE_OSCCLK: 3635 Use OSCM clock mode on MBX8xx board. Be careful, 3636 wrong setting might damage your board. Read 3637 doc/README.MBX before setting this variable! 3638 3639- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 3640 Offset of the bootmode word in DPRAM used by post 3641 (Power On Self Tests). This definition overrides 3642 #define'd default value in commproc.h resp. 3643 cpm_8260.h. 3644 3645- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 3646 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 3647 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 3648 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 3649 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 3650 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 3651 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 3652 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 3653 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 3654 3655- CONFIG_PCI_DISABLE_PCIE: 3656 Disable PCI-Express on systems where it is supported but not 3657 required. 3658 3659- CONFIG_PCI_ENUM_ONLY 3660 Only scan through and get the devices on the busses. 3661 Don't do any setup work, presumably because someone or 3662 something has already done it, and we don't need to do it 3663 a second time. Useful for platforms that are pre-booted 3664 by coreboot or similar. 3665 3666- CONFIG_SYS_SRIO: 3667 Chip has SRIO or not 3668 3669- CONFIG_SRIO1: 3670 Board has SRIO 1 port available 3671 3672- CONFIG_SRIO2: 3673 Board has SRIO 2 port available 3674 3675- CONFIG_SYS_SRIOn_MEM_VIRT: 3676 Virtual Address of SRIO port 'n' memory region 3677 3678- CONFIG_SYS_SRIOn_MEM_PHYS: 3679 Physical Address of SRIO port 'n' memory region 3680 3681- CONFIG_SYS_SRIOn_MEM_SIZE: 3682 Size of SRIO port 'n' memory region 3683 3684- CONFIG_SYS_NDFC_16 3685 Defined to tell the NDFC that the NAND chip is using a 3686 16 bit bus. 3687 3688- CONFIG_SYS_NDFC_EBC0_CFG 3689 Sets the EBC0_CFG register for the NDFC. If not defined 3690 a default value will be used. 3691 3692- CONFIG_SPD_EEPROM 3693 Get DDR timing information from an I2C EEPROM. Common 3694 with pluggable memory modules such as SODIMMs 3695 3696 SPD_EEPROM_ADDRESS 3697 I2C address of the SPD EEPROM 3698 3699- CONFIG_SYS_SPD_BUS_NUM 3700 If SPD EEPROM is on an I2C bus other than the first 3701 one, specify here. Note that the value must resolve 3702 to something your driver can deal with. 3703 3704- CONFIG_SYS_DDR_RAW_TIMING 3705 Get DDR timing information from other than SPD. Common with 3706 soldered DDR chips onboard without SPD. DDR raw timing 3707 parameters are extracted from datasheet and hard-coded into 3708 header files or board specific files. 3709 3710- CONFIG_FSL_DDR_INTERACTIVE 3711 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3712 3713- CONFIG_SYS_83XX_DDR_USES_CS0 3714 Only for 83xx systems. If specified, then DDR should 3715 be configured using CS0 and CS1 instead of CS2 and CS3. 3716 3717- CONFIG_ETHER_ON_FEC[12] 3718 Define to enable FEC[12] on a 8xx series processor. 3719 3720- CONFIG_FEC[12]_PHY 3721 Define to the hardcoded PHY address which corresponds 3722 to the given FEC; i. e. 3723 #define CONFIG_FEC1_PHY 4 3724 means that the PHY with address 4 is connected to FEC1 3725 3726 When set to -1, means to probe for first available. 3727 3728- CONFIG_FEC[12]_PHY_NORXERR 3729 The PHY does not have a RXERR line (RMII only). 3730 (so program the FEC to ignore it). 3731 3732- CONFIG_RMII 3733 Enable RMII mode for all FECs. 3734 Note that this is a global option, we can't 3735 have one FEC in standard MII mode and another in RMII mode. 3736 3737- CONFIG_CRC32_VERIFY 3738 Add a verify option to the crc32 command. 3739 The syntax is: 3740 3741 => crc32 -v <address> <count> <crc32> 3742 3743 Where address/count indicate a memory area 3744 and crc32 is the correct crc32 which the 3745 area should have. 3746 3747- CONFIG_LOOPW 3748 Add the "loopw" memory command. This only takes effect if 3749 the memory commands are activated globally (CONFIG_CMD_MEM). 3750 3751- CONFIG_MX_CYCLIC 3752 Add the "mdc" and "mwc" memory commands. These are cyclic 3753 "md/mw" commands. 3754 Examples: 3755 3756 => mdc.b 10 4 500 3757 This command will print 4 bytes (10,11,12,13) each 500 ms. 3758 3759 => mwc.l 100 12345678 10 3760 This command will write 12345678 to address 100 all 10 ms. 3761 3762 This only takes effect if the memory commands are activated 3763 globally (CONFIG_CMD_MEM). 3764 3765- CONFIG_SKIP_LOWLEVEL_INIT 3766 [ARM, NDS32, MIPS only] If this variable is defined, then certain 3767 low level initializations (like setting up the memory 3768 controller) are omitted and/or U-Boot does not 3769 relocate itself into RAM. 3770 3771 Normally this variable MUST NOT be defined. The only 3772 exception is when U-Boot is loaded (to RAM) by some 3773 other boot loader or by a debugger which performs 3774 these initializations itself. 3775 3776- CONFIG_SPL_BUILD 3777 Modifies the behaviour of start.S when compiling a loader 3778 that is executed before the actual U-Boot. E.g. when 3779 compiling a NAND SPL. 3780 3781- CONFIG_USE_ARCH_MEMCPY 3782 CONFIG_USE_ARCH_MEMSET 3783 If these options are used a optimized version of memcpy/memset will 3784 be used if available. These functions may be faster under some 3785 conditions but may increase the binary size. 3786 3787- CONFIG_X86_NO_RESET_VECTOR 3788 If defined, the x86 reset vector code is excluded. You will need 3789 to do this when U-Boot is running from Coreboot. 3790 3791- CONFIG_X86_NO_REAL_MODE 3792 If defined, x86 real mode code is omitted. This assumes a 3793 32-bit environment where such code is not needed. You will 3794 need to do this when U-Boot is running from Coreboot. 3795 3796 3797Freescale QE/FMAN Firmware Support: 3798----------------------------------- 3799 3800The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3801loading of "firmware", which is encoded in the QE firmware binary format. 3802This firmware often needs to be loaded during U-Boot booting, so macros 3803are used to identify the storage device (NOR flash, SPI, etc) and the address 3804within that device. 3805 3806- CONFIG_SYS_QE_FMAN_FW_ADDR 3807 The address in the storage device where the firmware is located. The 3808 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3809 is also specified. 3810 3811- CONFIG_SYS_QE_FMAN_FW_LENGTH 3812 The maximum possible size of the firmware. The firmware binary format 3813 has a field that specifies the actual size of the firmware, but it 3814 might not be possible to read any part of the firmware unless some 3815 local storage is allocated to hold the entire firmware first. 3816 3817- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3818 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3819 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3820 virtual address in NOR flash. 3821 3822- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3823 Specifies that QE/FMAN firmware is located in NAND flash. 3824 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3825 3826- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3827 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3828 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3829 3830- CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH 3831 Specifies that QE/FMAN firmware is located on the primary SPI 3832 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3833 3834- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3835 Specifies that QE/FMAN firmware is located in the remote (master) 3836 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3837 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3838 window->master inbound window->master LAW->the ucode address in 3839 master's memory space. 3840 3841Building the Software: 3842====================== 3843 3844Building U-Boot has been tested in several native build environments 3845and in many different cross environments. Of course we cannot support 3846all possibly existing versions of cross development tools in all 3847(potentially obsolete) versions. In case of tool chain problems we 3848recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3849which is extensively used to build and test U-Boot. 3850 3851If you are not using a native environment, it is assumed that you 3852have GNU cross compiling tools available in your path. In this case, 3853you must set the environment variable CROSS_COMPILE in your shell. 3854Note that no changes to the Makefile or any other source files are 3855necessary. For example using the ELDK on a 4xx CPU, please enter: 3856 3857 $ CROSS_COMPILE=ppc_4xx- 3858 $ export CROSS_COMPILE 3859 3860Note: If you wish to generate Windows versions of the utilities in 3861 the tools directory you can use the MinGW toolchain 3862 (http://www.mingw.org). Set your HOST tools to the MinGW 3863 toolchain and execute 'make tools'. For example: 3864 3865 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3866 3867 Binaries such as tools/mkimage.exe will be created which can 3868 be executed on computers running Windows. 3869 3870U-Boot is intended to be simple to build. After installing the 3871sources you must configure U-Boot for one specific board type. This 3872is done by typing: 3873 3874 make NAME_config 3875 3876where "NAME_config" is the name of one of the existing configu- 3877rations; see boards.cfg for supported names. 3878 3879Note: for some board special configuration names may exist; check if 3880 additional information is available from the board vendor; for 3881 instance, the TQM823L systems are available without (standard) 3882 or with LCD support. You can select such additional "features" 3883 when choosing the configuration, i. e. 3884 3885 make TQM823L_config 3886 - will configure for a plain TQM823L, i. e. no LCD support 3887 3888 make TQM823L_LCD_config 3889 - will configure for a TQM823L with U-Boot console on LCD 3890 3891 etc. 3892 3893 3894Finally, type "make all", and you should get some working U-Boot 3895images ready for download to / installation on your system: 3896 3897- "u-boot.bin" is a raw binary image 3898- "u-boot" is an image in ELF binary format 3899- "u-boot.srec" is in Motorola S-Record format 3900 3901By default the build is performed locally and the objects are saved 3902in the source directory. One of the two methods can be used to change 3903this behavior and build U-Boot to some external directory: 3904 39051. Add O= to the make command line invocations: 3906 3907 make O=/tmp/build distclean 3908 make O=/tmp/build NAME_config 3909 make O=/tmp/build all 3910 39112. Set environment variable BUILD_DIR to point to the desired location: 3912 3913 export BUILD_DIR=/tmp/build 3914 make distclean 3915 make NAME_config 3916 make all 3917 3918Note that the command line "O=" setting overrides the BUILD_DIR environment 3919variable. 3920 3921 3922Please be aware that the Makefiles assume you are using GNU make, so 3923for instance on NetBSD you might need to use "gmake" instead of 3924native "make". 3925 3926 3927If the system board that you have is not listed, then you will need 3928to port U-Boot to your hardware platform. To do this, follow these 3929steps: 3930 39311. Add a new configuration option for your board to the toplevel 3932 "boards.cfg" file, using the existing entries as examples. 3933 Follow the instructions there to keep the boards in order. 39342. Create a new directory to hold your board specific code. Add any 3935 files you need. In your board directory, you will need at least 3936 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 39373. Create a new configuration file "include/configs/<board>.h" for 3938 your board 39393. If you're porting U-Boot to a new CPU, then also create a new 3940 directory to hold your CPU specific code. Add any files you need. 39414. Run "make <board>_config" with your new name. 39425. Type "make", and you should get a working "u-boot.srec" file 3943 to be installed on your target system. 39446. Debug and solve any problems that might arise. 3945 [Of course, this last step is much harder than it sounds.] 3946 3947 3948Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3949============================================================== 3950 3951If you have modified U-Boot sources (for instance added a new board 3952or support for new devices, a new CPU, etc.) you are expected to 3953provide feedback to the other developers. The feedback normally takes 3954the form of a "patch", i. e. a context diff against a certain (latest 3955official or latest in the git repository) version of U-Boot sources. 3956 3957But before you submit such a patch, please verify that your modifi- 3958cation did not break existing code. At least make sure that *ALL* of 3959the supported boards compile WITHOUT ANY compiler warnings. To do so, 3960just run the "MAKEALL" script, which will configure and build U-Boot 3961for ALL supported system. Be warned, this will take a while. You can 3962select which (cross) compiler to use by passing a `CROSS_COMPILE' 3963environment variable to the script, i. e. to use the ELDK cross tools 3964you can type 3965 3966 CROSS_COMPILE=ppc_8xx- MAKEALL 3967 3968or to build on a native PowerPC system you can type 3969 3970 CROSS_COMPILE=' ' MAKEALL 3971 3972When using the MAKEALL script, the default behaviour is to build 3973U-Boot in the source directory. This location can be changed by 3974setting the BUILD_DIR environment variable. Also, for each target 3975built, the MAKEALL script saves two log files (<target>.ERR and 3976<target>.MAKEALL) in the <source dir>/LOG directory. This default 3977location can be changed by setting the MAKEALL_LOGDIR environment 3978variable. For example: 3979 3980 export BUILD_DIR=/tmp/build 3981 export MAKEALL_LOGDIR=/tmp/log 3982 CROSS_COMPILE=ppc_8xx- MAKEALL 3983 3984With the above settings build objects are saved in the /tmp/build, 3985log files are saved in the /tmp/log and the source tree remains clean 3986during the whole build process. 3987 3988 3989See also "U-Boot Porting Guide" below. 3990 3991 3992Monitor Commands - Overview: 3993============================ 3994 3995go - start application at address 'addr' 3996run - run commands in an environment variable 3997bootm - boot application image from memory 3998bootp - boot image via network using BootP/TFTP protocol 3999bootz - boot zImage from memory 4000tftpboot- boot image via network using TFTP protocol 4001 and env variables "ipaddr" and "serverip" 4002 (and eventually "gatewayip") 4003tftpput - upload a file via network using TFTP protocol 4004rarpboot- boot image via network using RARP/TFTP protocol 4005diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4006loads - load S-Record file over serial line 4007loadb - load binary file over serial line (kermit mode) 4008md - memory display 4009mm - memory modify (auto-incrementing) 4010nm - memory modify (constant address) 4011mw - memory write (fill) 4012cp - memory copy 4013cmp - memory compare 4014crc32 - checksum calculation 4015i2c - I2C sub-system 4016sspi - SPI utility commands 4017base - print or set address offset 4018printenv- print environment variables 4019setenv - set environment variables 4020saveenv - save environment variables to persistent storage 4021protect - enable or disable FLASH write protection 4022erase - erase FLASH memory 4023flinfo - print FLASH memory information 4024nand - NAND memory operations (see doc/README.nand) 4025bdinfo - print Board Info structure 4026iminfo - print header information for application image 4027coninfo - print console devices and informations 4028ide - IDE sub-system 4029loop - infinite loop on address range 4030loopw - infinite write loop on address range 4031mtest - simple RAM test 4032icache - enable or disable instruction cache 4033dcache - enable or disable data cache 4034reset - Perform RESET of the CPU 4035echo - echo args to console 4036version - print monitor version 4037help - print online help 4038? - alias for 'help' 4039 4040 4041Monitor Commands - Detailed Description: 4042======================================== 4043 4044TODO. 4045 4046For now: just type "help <command>". 4047 4048 4049Environment Variables: 4050====================== 4051 4052U-Boot supports user configuration using Environment Variables which 4053can be made persistent by saving to Flash memory. 4054 4055Environment Variables are set using "setenv", printed using 4056"printenv", and saved to Flash using "saveenv". Using "setenv" 4057without a value can be used to delete a variable from the 4058environment. As long as you don't save the environment you are 4059working with an in-memory copy. In case the Flash area containing the 4060environment is erased by accident, a default environment is provided. 4061 4062Some configuration options can be set using Environment Variables. 4063 4064List of environment variables (most likely not complete): 4065 4066 baudrate - see CONFIG_BAUDRATE 4067 4068 bootdelay - see CONFIG_BOOTDELAY 4069 4070 bootcmd - see CONFIG_BOOTCOMMAND 4071 4072 bootargs - Boot arguments when booting an RTOS image 4073 4074 bootfile - Name of the image to load with TFTP 4075 4076 bootm_low - Memory range available for image processing in the bootm 4077 command can be restricted. This variable is given as 4078 a hexadecimal number and defines lowest address allowed 4079 for use by the bootm command. See also "bootm_size" 4080 environment variable. Address defined by "bootm_low" is 4081 also the base of the initial memory mapping for the Linux 4082 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4083 bootm_mapsize. 4084 4085 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4086 This variable is given as a hexadecimal number and it 4087 defines the size of the memory region starting at base 4088 address bootm_low that is accessible by the Linux kernel 4089 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4090 as the default value if it is defined, and bootm_size is 4091 used otherwise. 4092 4093 bootm_size - Memory range available for image processing in the bootm 4094 command can be restricted. This variable is given as 4095 a hexadecimal number and defines the size of the region 4096 allowed for use by the bootm command. See also "bootm_low" 4097 environment variable. 4098 4099 updatefile - Location of the software update file on a TFTP server, used 4100 by the automatic software update feature. Please refer to 4101 documentation in doc/README.update for more details. 4102 4103 autoload - if set to "no" (any string beginning with 'n'), 4104 "bootp" will just load perform a lookup of the 4105 configuration from the BOOTP server, but not try to 4106 load any image using TFTP 4107 4108 autostart - if set to "yes", an image loaded using the "bootp", 4109 "rarpboot", "tftpboot" or "diskboot" commands will 4110 be automatically started (by internally calling 4111 "bootm") 4112 4113 If set to "no", a standalone image passed to the 4114 "bootm" command will be copied to the load address 4115 (and eventually uncompressed), but NOT be started. 4116 This can be used to load and uncompress arbitrary 4117 data. 4118 4119 fdt_high - if set this restricts the maximum address that the 4120 flattened device tree will be copied into upon boot. 4121 For example, if you have a system with 1 GB memory 4122 at physical address 0x10000000, while Linux kernel 4123 only recognizes the first 704 MB as low memory, you 4124 may need to set fdt_high as 0x3C000000 to have the 4125 device tree blob be copied to the maximum address 4126 of the 704 MB low memory, so that Linux kernel can 4127 access it during the boot procedure. 4128 4129 If this is set to the special value 0xFFFFFFFF then 4130 the fdt will not be copied at all on boot. For this 4131 to work it must reside in writable memory, have 4132 sufficient padding on the end of it for u-boot to 4133 add the information it needs into it, and the memory 4134 must be accessible by the kernel. 4135 4136 fdtcontroladdr- if set this is the address of the control flattened 4137 device tree used by U-Boot when CONFIG_OF_CONTROL is 4138 defined. 4139 4140 i2cfast - (PPC405GP|PPC405EP only) 4141 if set to 'y' configures Linux I2C driver for fast 4142 mode (400kHZ). This environment variable is used in 4143 initialization code. So, for changes to be effective 4144 it must be saved and board must be reset. 4145 4146 initrd_high - restrict positioning of initrd images: 4147 If this variable is not set, initrd images will be 4148 copied to the highest possible address in RAM; this 4149 is usually what you want since it allows for 4150 maximum initrd size. If for some reason you want to 4151 make sure that the initrd image is loaded below the 4152 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4153 variable to a value of "no" or "off" or "0". 4154 Alternatively, you can set it to a maximum upper 4155 address to use (U-Boot will still check that it 4156 does not overwrite the U-Boot stack and data). 4157 4158 For instance, when you have a system with 16 MB 4159 RAM, and want to reserve 4 MB from use by Linux, 4160 you can do this by adding "mem=12M" to the value of 4161 the "bootargs" variable. However, now you must make 4162 sure that the initrd image is placed in the first 4163 12 MB as well - this can be done with 4164 4165 setenv initrd_high 00c00000 4166 4167 If you set initrd_high to 0xFFFFFFFF, this is an 4168 indication to U-Boot that all addresses are legal 4169 for the Linux kernel, including addresses in flash 4170 memory. In this case U-Boot will NOT COPY the 4171 ramdisk at all. This may be useful to reduce the 4172 boot time on your system, but requires that this 4173 feature is supported by your Linux kernel. 4174 4175 ipaddr - IP address; needed for tftpboot command 4176 4177 loadaddr - Default load address for commands like "bootp", 4178 "rarpboot", "tftpboot", "loadb" or "diskboot" 4179 4180 loads_echo - see CONFIG_LOADS_ECHO 4181 4182 serverip - TFTP server IP address; needed for tftpboot command 4183 4184 bootretry - see CONFIG_BOOT_RETRY_TIME 4185 4186 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4187 4188 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4189 4190 ethprime - controls which interface is used first. 4191 4192 ethact - controls which interface is currently active. 4193 For example you can do the following 4194 4195 => setenv ethact FEC 4196 => ping 192.168.0.1 # traffic sent on FEC 4197 => setenv ethact SCC 4198 => ping 10.0.0.1 # traffic sent on SCC 4199 4200 ethrotate - When set to "no" U-Boot does not go through all 4201 available network interfaces. 4202 It just stays at the currently selected interface. 4203 4204 netretry - When set to "no" each network operation will 4205 either succeed or fail without retrying. 4206 When set to "once" the network operation will 4207 fail when all the available network interfaces 4208 are tried once without success. 4209 Useful on scripts which control the retry operation 4210 themselves. 4211 4212 npe_ucode - set load address for the NPE microcode 4213 4214 tftpsrcport - If this is set, the value is used for TFTP's 4215 UDP source port. 4216 4217 tftpdstport - If this is set, the value is used for TFTP's UDP 4218 destination port instead of the Well Know Port 69. 4219 4220 tftpblocksize - Block size to use for TFTP transfers; if not set, 4221 we use the TFTP server's default block size 4222 4223 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4224 seconds, minimum value is 1000 = 1 second). Defines 4225 when a packet is considered to be lost so it has to 4226 be retransmitted. The default is 5000 = 5 seconds. 4227 Lowering this value may make downloads succeed 4228 faster in networks with high packet loss rates or 4229 with unreliable TFTP servers. 4230 4231 vlan - When set to a value < 4095 the traffic over 4232 Ethernet is encapsulated/received over 802.1q 4233 VLAN tagged frames. 4234 4235The following image location variables contain the location of images 4236used in booting. The "Image" column gives the role of the image and is 4237not an environment variable name. The other columns are environment 4238variable names. "File Name" gives the name of the file on a TFTP 4239server, "RAM Address" gives the location in RAM the image will be 4240loaded to, and "Flash Location" gives the image's address in NOR 4241flash or offset in NAND flash. 4242 4243*Note* - these variables don't have to be defined for all boards, some 4244boards currenlty use other variables for these purposes, and some 4245boards use these variables for other purposes. 4246 4247Image File Name RAM Address Flash Location 4248----- --------- ----------- -------------- 4249u-boot u-boot u-boot_addr_r u-boot_addr 4250Linux kernel bootfile kernel_addr_r kernel_addr 4251device tree blob fdtfile fdt_addr_r fdt_addr 4252ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4253 4254The following environment variables may be used and automatically 4255updated by the network boot commands ("bootp" and "rarpboot"), 4256depending the information provided by your boot server: 4257 4258 bootfile - see above 4259 dnsip - IP address of your Domain Name Server 4260 dnsip2 - IP address of your secondary Domain Name Server 4261 gatewayip - IP address of the Gateway (Router) to use 4262 hostname - Target hostname 4263 ipaddr - see above 4264 netmask - Subnet Mask 4265 rootpath - Pathname of the root filesystem on the NFS server 4266 serverip - see above 4267 4268 4269There are two special Environment Variables: 4270 4271 serial# - contains hardware identification information such 4272 as type string and/or serial number 4273 ethaddr - Ethernet address 4274 4275These variables can be set only once (usually during manufacturing of 4276the board). U-Boot refuses to delete or overwrite these variables 4277once they have been set once. 4278 4279 4280Further special Environment Variables: 4281 4282 ver - Contains the U-Boot version string as printed 4283 with the "version" command. This variable is 4284 readonly (see CONFIG_VERSION_VARIABLE). 4285 4286 4287Please note that changes to some configuration parameters may take 4288only effect after the next boot (yes, that's just like Windoze :-). 4289 4290 4291Callback functions for environment variables: 4292--------------------------------------------- 4293 4294For some environment variables, the behavior of u-boot needs to change 4295when their values are changed. This functionailty allows functions to 4296be associated with arbitrary variables. On creation, overwrite, or 4297deletion, the callback will provide the opportunity for some side 4298effect to happen or for the change to be rejected. 4299 4300The callbacks are named and associated with a function using the 4301U_BOOT_ENV_CALLBACK macro in your board or driver code. 4302 4303These callbacks are associated with variables in one of two ways. The 4304static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4305in the board configuration to a string that defines a list of 4306associations. The list must be in the following format: 4307 4308 entry = variable_name[:callback_name] 4309 list = entry[,list] 4310 4311If the callback name is not specified, then the callback is deleted. 4312Spaces are also allowed anywhere in the list. 4313 4314Callbacks can also be associated by defining the ".callbacks" variable 4315with the same list format above. Any association in ".callbacks" will 4316override any association in the static list. You can define 4317CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4318".callbacks" envirnoment variable in the default or embedded environment. 4319 4320 4321Command Line Parsing: 4322===================== 4323 4324There are two different command line parsers available with U-Boot: 4325the old "simple" one, and the much more powerful "hush" shell: 4326 4327Old, simple command line parser: 4328-------------------------------- 4329 4330- supports environment variables (through setenv / saveenv commands) 4331- several commands on one line, separated by ';' 4332- variable substitution using "... ${name} ..." syntax 4333- special characters ('$', ';') can be escaped by prefixing with '\', 4334 for example: 4335 setenv bootcmd bootm \${address} 4336- You can also escape text by enclosing in single apostrophes, for example: 4337 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4338 4339Hush shell: 4340----------- 4341 4342- similar to Bourne shell, with control structures like 4343 if...then...else...fi, for...do...done; while...do...done, 4344 until...do...done, ... 4345- supports environment ("global") variables (through setenv / saveenv 4346 commands) and local shell variables (through standard shell syntax 4347 "name=value"); only environment variables can be used with "run" 4348 command 4349 4350General rules: 4351-------------- 4352 4353(1) If a command line (or an environment variable executed by a "run" 4354 command) contains several commands separated by semicolon, and 4355 one of these commands fails, then the remaining commands will be 4356 executed anyway. 4357 4358(2) If you execute several variables with one call to run (i. e. 4359 calling run with a list of variables as arguments), any failing 4360 command will cause "run" to terminate, i. e. the remaining 4361 variables are not executed. 4362 4363Note for Redundant Ethernet Interfaces: 4364======================================= 4365 4366Some boards come with redundant Ethernet interfaces; U-Boot supports 4367such configurations and is capable of automatic selection of a 4368"working" interface when needed. MAC assignment works as follows: 4369 4370Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4371MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4372"eth1addr" (=>eth1), "eth2addr", ... 4373 4374If the network interface stores some valid MAC address (for instance 4375in SROM), this is used as default address if there is NO correspon- 4376ding setting in the environment; if the corresponding environment 4377variable is set, this overrides the settings in the card; that means: 4378 4379o If the SROM has a valid MAC address, and there is no address in the 4380 environment, the SROM's address is used. 4381 4382o If there is no valid address in the SROM, and a definition in the 4383 environment exists, then the value from the environment variable is 4384 used. 4385 4386o If both the SROM and the environment contain a MAC address, and 4387 both addresses are the same, this MAC address is used. 4388 4389o If both the SROM and the environment contain a MAC address, and the 4390 addresses differ, the value from the environment is used and a 4391 warning is printed. 4392 4393o If neither SROM nor the environment contain a MAC address, an error 4394 is raised. 4395 4396If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4397will be programmed into hardware as part of the initialization process. This 4398may be skipped by setting the appropriate 'ethmacskip' environment variable. 4399The naming convention is as follows: 4400"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4401 4402Image Formats: 4403============== 4404 4405U-Boot is capable of booting (and performing other auxiliary operations on) 4406images in two formats: 4407 4408New uImage format (FIT) 4409----------------------- 4410 4411Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4412to Flattened Device Tree). It allows the use of images with multiple 4413components (several kernels, ramdisks, etc.), with contents protected by 4414SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4415 4416 4417Old uImage format 4418----------------- 4419 4420Old image format is based on binary files which can be basically anything, 4421preceded by a special header; see the definitions in include/image.h for 4422details; basically, the header defines the following image properties: 4423 4424* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4425 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4426 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4427 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4428 INTEGRITY). 4429* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 4430 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4431 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4432* Compression Type (uncompressed, gzip, bzip2) 4433* Load Address 4434* Entry Point 4435* Image Name 4436* Image Timestamp 4437 4438The header is marked by a special Magic Number, and both the header 4439and the data portions of the image are secured against corruption by 4440CRC32 checksums. 4441 4442 4443Linux Support: 4444============== 4445 4446Although U-Boot should support any OS or standalone application 4447easily, the main focus has always been on Linux during the design of 4448U-Boot. 4449 4450U-Boot includes many features that so far have been part of some 4451special "boot loader" code within the Linux kernel. Also, any 4452"initrd" images to be used are no longer part of one big Linux image; 4453instead, kernel and "initrd" are separate images. This implementation 4454serves several purposes: 4455 4456- the same features can be used for other OS or standalone 4457 applications (for instance: using compressed images to reduce the 4458 Flash memory footprint) 4459 4460- it becomes much easier to port new Linux kernel versions because 4461 lots of low-level, hardware dependent stuff are done by U-Boot 4462 4463- the same Linux kernel image can now be used with different "initrd" 4464 images; of course this also means that different kernel images can 4465 be run with the same "initrd". This makes testing easier (you don't 4466 have to build a new "zImage.initrd" Linux image when you just 4467 change a file in your "initrd"). Also, a field-upgrade of the 4468 software is easier now. 4469 4470 4471Linux HOWTO: 4472============ 4473 4474Porting Linux to U-Boot based systems: 4475--------------------------------------- 4476 4477U-Boot cannot save you from doing all the necessary modifications to 4478configure the Linux device drivers for use with your target hardware 4479(no, we don't intend to provide a full virtual machine interface to 4480Linux :-). 4481 4482But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4483 4484Just make sure your machine specific header file (for instance 4485include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4486Information structure as we define in include/asm-<arch>/u-boot.h, 4487and make sure that your definition of IMAP_ADDR uses the same value 4488as your U-Boot configuration in CONFIG_SYS_IMMR. 4489 4490 4491Configuring the Linux kernel: 4492----------------------------- 4493 4494No specific requirements for U-Boot. Make sure you have some root 4495device (initial ramdisk, NFS) for your target system. 4496 4497 4498Building a Linux Image: 4499----------------------- 4500 4501With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4502not used. If you use recent kernel source, a new build target 4503"uImage" will exist which automatically builds an image usable by 4504U-Boot. Most older kernels also have support for a "pImage" target, 4505which was introduced for our predecessor project PPCBoot and uses a 4506100% compatible format. 4507 4508Example: 4509 4510 make TQM850L_config 4511 make oldconfig 4512 make dep 4513 make uImage 4514 4515The "uImage" build target uses a special tool (in 'tools/mkimage') to 4516encapsulate a compressed Linux kernel image with header information, 4517CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4518 4519* build a standard "vmlinux" kernel image (in ELF binary format): 4520 4521* convert the kernel into a raw binary image: 4522 4523 ${CROSS_COMPILE}-objcopy -O binary \ 4524 -R .note -R .comment \ 4525 -S vmlinux linux.bin 4526 4527* compress the binary image: 4528 4529 gzip -9 linux.bin 4530 4531* package compressed binary image for U-Boot: 4532 4533 mkimage -A ppc -O linux -T kernel -C gzip \ 4534 -a 0 -e 0 -n "Linux Kernel Image" \ 4535 -d linux.bin.gz uImage 4536 4537 4538The "mkimage" tool can also be used to create ramdisk images for use 4539with U-Boot, either separated from the Linux kernel image, or 4540combined into one file. "mkimage" encapsulates the images with a 64 4541byte header containing information about target architecture, 4542operating system, image type, compression method, entry points, time 4543stamp, CRC32 checksums, etc. 4544 4545"mkimage" can be called in two ways: to verify existing images and 4546print the header information, or to build new images. 4547 4548In the first form (with "-l" option) mkimage lists the information 4549contained in the header of an existing U-Boot image; this includes 4550checksum verification: 4551 4552 tools/mkimage -l image 4553 -l ==> list image header information 4554 4555The second form (with "-d" option) is used to build a U-Boot image 4556from a "data file" which is used as image payload: 4557 4558 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4559 -n name -d data_file image 4560 -A ==> set architecture to 'arch' 4561 -O ==> set operating system to 'os' 4562 -T ==> set image type to 'type' 4563 -C ==> set compression type 'comp' 4564 -a ==> set load address to 'addr' (hex) 4565 -e ==> set entry point to 'ep' (hex) 4566 -n ==> set image name to 'name' 4567 -d ==> use image data from 'datafile' 4568 4569Right now, all Linux kernels for PowerPC systems use the same load 4570address (0x00000000), but the entry point address depends on the 4571kernel version: 4572 4573- 2.2.x kernels have the entry point at 0x0000000C, 4574- 2.3.x and later kernels have the entry point at 0x00000000. 4575 4576So a typical call to build a U-Boot image would read: 4577 4578 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4579 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4580 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4581 > examples/uImage.TQM850L 4582 Image Name: 2.4.4 kernel for TQM850L 4583 Created: Wed Jul 19 02:34:59 2000 4584 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4585 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4586 Load Address: 0x00000000 4587 Entry Point: 0x00000000 4588 4589To verify the contents of the image (or check for corruption): 4590 4591 -> tools/mkimage -l examples/uImage.TQM850L 4592 Image Name: 2.4.4 kernel for TQM850L 4593 Created: Wed Jul 19 02:34:59 2000 4594 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4595 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4596 Load Address: 0x00000000 4597 Entry Point: 0x00000000 4598 4599NOTE: for embedded systems where boot time is critical you can trade 4600speed for memory and install an UNCOMPRESSED image instead: this 4601needs more space in Flash, but boots much faster since it does not 4602need to be uncompressed: 4603 4604 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4605 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4606 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4607 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4608 > examples/uImage.TQM850L-uncompressed 4609 Image Name: 2.4.4 kernel for TQM850L 4610 Created: Wed Jul 19 02:34:59 2000 4611 Image Type: PowerPC Linux Kernel Image (uncompressed) 4612 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4613 Load Address: 0x00000000 4614 Entry Point: 0x00000000 4615 4616 4617Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4618when your kernel is intended to use an initial ramdisk: 4619 4620 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4621 > -A ppc -O linux -T ramdisk -C gzip \ 4622 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4623 Image Name: Simple Ramdisk Image 4624 Created: Wed Jan 12 14:01:50 2000 4625 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4626 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4627 Load Address: 0x00000000 4628 Entry Point: 0x00000000 4629 4630 4631Installing a Linux Image: 4632------------------------- 4633 4634To downloading a U-Boot image over the serial (console) interface, 4635you must convert the image to S-Record format: 4636 4637 objcopy -I binary -O srec examples/image examples/image.srec 4638 4639The 'objcopy' does not understand the information in the U-Boot 4640image header, so the resulting S-Record file will be relative to 4641address 0x00000000. To load it to a given address, you need to 4642specify the target address as 'offset' parameter with the 'loads' 4643command. 4644 4645Example: install the image to address 0x40100000 (which on the 4646TQM8xxL is in the first Flash bank): 4647 4648 => erase 40100000 401FFFFF 4649 4650 .......... done 4651 Erased 8 sectors 4652 4653 => loads 40100000 4654 ## Ready for S-Record download ... 4655 ~>examples/image.srec 4656 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4657 ... 4658 15989 15990 15991 15992 4659 [file transfer complete] 4660 [connected] 4661 ## Start Addr = 0x00000000 4662 4663 4664You can check the success of the download using the 'iminfo' command; 4665this includes a checksum verification so you can be sure no data 4666corruption happened: 4667 4668 => imi 40100000 4669 4670 ## Checking Image at 40100000 ... 4671 Image Name: 2.2.13 for initrd on TQM850L 4672 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4673 Data Size: 335725 Bytes = 327 kB = 0 MB 4674 Load Address: 00000000 4675 Entry Point: 0000000c 4676 Verifying Checksum ... OK 4677 4678 4679Boot Linux: 4680----------- 4681 4682The "bootm" command is used to boot an application that is stored in 4683memory (RAM or Flash). In case of a Linux kernel image, the contents 4684of the "bootargs" environment variable is passed to the kernel as 4685parameters. You can check and modify this variable using the 4686"printenv" and "setenv" commands: 4687 4688 4689 => printenv bootargs 4690 bootargs=root=/dev/ram 4691 4692 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4693 4694 => printenv bootargs 4695 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4696 4697 => bootm 40020000 4698 ## Booting Linux kernel at 40020000 ... 4699 Image Name: 2.2.13 for NFS on TQM850L 4700 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4701 Data Size: 381681 Bytes = 372 kB = 0 MB 4702 Load Address: 00000000 4703 Entry Point: 0000000c 4704 Verifying Checksum ... OK 4705 Uncompressing Kernel Image ... OK 4706 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 4707 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4708 time_init: decrementer frequency = 187500000/60 4709 Calibrating delay loop... 49.77 BogoMIPS 4710 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4711 ... 4712 4713If you want to boot a Linux kernel with initial RAM disk, you pass 4714the memory addresses of both the kernel and the initrd image (PPBCOOT 4715format!) to the "bootm" command: 4716 4717 => imi 40100000 40200000 4718 4719 ## Checking Image at 40100000 ... 4720 Image Name: 2.2.13 for initrd on TQM850L 4721 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4722 Data Size: 335725 Bytes = 327 kB = 0 MB 4723 Load Address: 00000000 4724 Entry Point: 0000000c 4725 Verifying Checksum ... OK 4726 4727 ## Checking Image at 40200000 ... 4728 Image Name: Simple Ramdisk Image 4729 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4730 Data Size: 566530 Bytes = 553 kB = 0 MB 4731 Load Address: 00000000 4732 Entry Point: 00000000 4733 Verifying Checksum ... OK 4734 4735 => bootm 40100000 40200000 4736 ## Booting Linux kernel at 40100000 ... 4737 Image Name: 2.2.13 for initrd on TQM850L 4738 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4739 Data Size: 335725 Bytes = 327 kB = 0 MB 4740 Load Address: 00000000 4741 Entry Point: 0000000c 4742 Verifying Checksum ... OK 4743 Uncompressing Kernel Image ... OK 4744 ## Loading RAMDisk Image at 40200000 ... 4745 Image Name: Simple Ramdisk Image 4746 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4747 Data Size: 566530 Bytes = 553 kB = 0 MB 4748 Load Address: 00000000 4749 Entry Point: 00000000 4750 Verifying Checksum ... OK 4751 Loading Ramdisk ... OK 4752 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 4753 Boot arguments: root=/dev/ram 4754 time_init: decrementer frequency = 187500000/60 4755 Calibrating delay loop... 49.77 BogoMIPS 4756 ... 4757 RAMDISK: Compressed image found at block 0 4758 VFS: Mounted root (ext2 filesystem). 4759 4760 bash# 4761 4762Boot Linux and pass a flat device tree: 4763----------- 4764 4765First, U-Boot must be compiled with the appropriate defines. See the section 4766titled "Linux Kernel Interface" above for a more in depth explanation. The 4767following is an example of how to start a kernel and pass an updated 4768flat device tree: 4769 4770=> print oftaddr 4771oftaddr=0x300000 4772=> print oft 4773oft=oftrees/mpc8540ads.dtb 4774=> tftp $oftaddr $oft 4775Speed: 1000, full duplex 4776Using TSEC0 device 4777TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4778Filename 'oftrees/mpc8540ads.dtb'. 4779Load address: 0x300000 4780Loading: # 4781done 4782Bytes transferred = 4106 (100a hex) 4783=> tftp $loadaddr $bootfile 4784Speed: 1000, full duplex 4785Using TSEC0 device 4786TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4787Filename 'uImage'. 4788Load address: 0x200000 4789Loading:############ 4790done 4791Bytes transferred = 1029407 (fb51f hex) 4792=> print loadaddr 4793loadaddr=200000 4794=> print oftaddr 4795oftaddr=0x300000 4796=> bootm $loadaddr - $oftaddr 4797## Booting image at 00200000 ... 4798 Image Name: Linux-2.6.17-dirty 4799 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4800 Data Size: 1029343 Bytes = 1005.2 kB 4801 Load Address: 00000000 4802 Entry Point: 00000000 4803 Verifying Checksum ... OK 4804 Uncompressing Kernel Image ... OK 4805Booting using flat device tree at 0x300000 4806Using MPC85xx ADS machine description 4807Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4808[snip] 4809 4810 4811More About U-Boot Image Types: 4812------------------------------ 4813 4814U-Boot supports the following image types: 4815 4816 "Standalone Programs" are directly runnable in the environment 4817 provided by U-Boot; it is expected that (if they behave 4818 well) you can continue to work in U-Boot after return from 4819 the Standalone Program. 4820 "OS Kernel Images" are usually images of some Embedded OS which 4821 will take over control completely. Usually these programs 4822 will install their own set of exception handlers, device 4823 drivers, set up the MMU, etc. - this means, that you cannot 4824 expect to re-enter U-Boot except by resetting the CPU. 4825 "RAMDisk Images" are more or less just data blocks, and their 4826 parameters (address, size) are passed to an OS kernel that is 4827 being started. 4828 "Multi-File Images" contain several images, typically an OS 4829 (Linux) kernel image and one or more data images like 4830 RAMDisks. This construct is useful for instance when you want 4831 to boot over the network using BOOTP etc., where the boot 4832 server provides just a single image file, but you want to get 4833 for instance an OS kernel and a RAMDisk image. 4834 4835 "Multi-File Images" start with a list of image sizes, each 4836 image size (in bytes) specified by an "uint32_t" in network 4837 byte order. This list is terminated by an "(uint32_t)0". 4838 Immediately after the terminating 0 follow the images, one by 4839 one, all aligned on "uint32_t" boundaries (size rounded up to 4840 a multiple of 4 bytes). 4841 4842 "Firmware Images" are binary images containing firmware (like 4843 U-Boot or FPGA images) which usually will be programmed to 4844 flash memory. 4845 4846 "Script files" are command sequences that will be executed by 4847 U-Boot's command interpreter; this feature is especially 4848 useful when you configure U-Boot to use a real shell (hush) 4849 as command interpreter. 4850 4851Booting the Linux zImage: 4852------------------------- 4853 4854On some platforms, it's possible to boot Linux zImage. This is done 4855using the "bootz" command. The syntax of "bootz" command is the same 4856as the syntax of "bootm" command. 4857 4858Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply 4859kernel with raw initrd images. The syntax is slightly different, the 4860address of the initrd must be augmented by it's size, in the following 4861format: "<initrd addres>:<initrd size>". 4862 4863 4864Standalone HOWTO: 4865================= 4866 4867One of the features of U-Boot is that you can dynamically load and 4868run "standalone" applications, which can use some resources of 4869U-Boot like console I/O functions or interrupt services. 4870 4871Two simple examples are included with the sources: 4872 4873"Hello World" Demo: 4874------------------- 4875 4876'examples/hello_world.c' contains a small "Hello World" Demo 4877application; it is automatically compiled when you build U-Boot. 4878It's configured to run at address 0x00040004, so you can play with it 4879like that: 4880 4881 => loads 4882 ## Ready for S-Record download ... 4883 ~>examples/hello_world.srec 4884 1 2 3 4 5 6 7 8 9 10 11 ... 4885 [file transfer complete] 4886 [connected] 4887 ## Start Addr = 0x00040004 4888 4889 => go 40004 Hello World! This is a test. 4890 ## Starting application at 0x00040004 ... 4891 Hello World 4892 argc = 7 4893 argv[0] = "40004" 4894 argv[1] = "Hello" 4895 argv[2] = "World!" 4896 argv[3] = "This" 4897 argv[4] = "is" 4898 argv[5] = "a" 4899 argv[6] = "test." 4900 argv[7] = "<NULL>" 4901 Hit any key to exit ... 4902 4903 ## Application terminated, rc = 0x0 4904 4905Another example, which demonstrates how to register a CPM interrupt 4906handler with the U-Boot code, can be found in 'examples/timer.c'. 4907Here, a CPM timer is set up to generate an interrupt every second. 4908The interrupt service routine is trivial, just printing a '.' 4909character, but this is just a demo program. The application can be 4910controlled by the following keys: 4911 4912 ? - print current values og the CPM Timer registers 4913 b - enable interrupts and start timer 4914 e - stop timer and disable interrupts 4915 q - quit application 4916 4917 => loads 4918 ## Ready for S-Record download ... 4919 ~>examples/timer.srec 4920 1 2 3 4 5 6 7 8 9 10 11 ... 4921 [file transfer complete] 4922 [connected] 4923 ## Start Addr = 0x00040004 4924 4925 => go 40004 4926 ## Starting application at 0x00040004 ... 4927 TIMERS=0xfff00980 4928 Using timer 1 4929 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4930 4931Hit 'b': 4932 [q, b, e, ?] Set interval 1000000 us 4933 Enabling timer 4934Hit '?': 4935 [q, b, e, ?] ........ 4936 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4937Hit '?': 4938 [q, b, e, ?] . 4939 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4940Hit '?': 4941 [q, b, e, ?] . 4942 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4943Hit '?': 4944 [q, b, e, ?] . 4945 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4946Hit 'e': 4947 [q, b, e, ?] ...Stopping timer 4948Hit 'q': 4949 [q, b, e, ?] ## Application terminated, rc = 0x0 4950 4951 4952Minicom warning: 4953================ 4954 4955Over time, many people have reported problems when trying to use the 4956"minicom" terminal emulation program for serial download. I (wd) 4957consider minicom to be broken, and recommend not to use it. Under 4958Unix, I recommend to use C-Kermit for general purpose use (and 4959especially for kermit binary protocol download ("loadb" command), and 4960use "cu" for S-Record download ("loads" command). See 4961http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4962for help with kermit. 4963 4964 4965Nevertheless, if you absolutely want to use it try adding this 4966configuration to your "File transfer protocols" section: 4967 4968 Name Program Name U/D FullScr IO-Red. Multi 4969 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4970 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4971 4972 4973NetBSD Notes: 4974============= 4975 4976Starting at version 0.9.2, U-Boot supports NetBSD both as host 4977(build U-Boot) and target system (boots NetBSD/mpc8xx). 4978 4979Building requires a cross environment; it is known to work on 4980NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4981need gmake since the Makefiles are not compatible with BSD make). 4982Note that the cross-powerpc package does not install include files; 4983attempting to build U-Boot will fail because <machine/ansi.h> is 4984missing. This file has to be installed and patched manually: 4985 4986 # cd /usr/pkg/cross/powerpc-netbsd/include 4987 # mkdir powerpc 4988 # ln -s powerpc machine 4989 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4990 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4991 4992Native builds *don't* work due to incompatibilities between native 4993and U-Boot include files. 4994 4995Booting assumes that (the first part of) the image booted is a 4996stage-2 loader which in turn loads and then invokes the kernel 4997proper. Loader sources will eventually appear in the NetBSD source 4998tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4999meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5000 5001 5002Implementation Internals: 5003========================= 5004 5005The following is not intended to be a complete description of every 5006implementation detail. However, it should help to understand the 5007inner workings of U-Boot and make it easier to port it to custom 5008hardware. 5009 5010 5011Initial Stack, Global Data: 5012--------------------------- 5013 5014The implementation of U-Boot is complicated by the fact that U-Boot 5015starts running out of ROM (flash memory), usually without access to 5016system RAM (because the memory controller is not initialized yet). 5017This means that we don't have writable Data or BSS segments, and BSS 5018is not initialized as zero. To be able to get a C environment working 5019at all, we have to allocate at least a minimal stack. Implementation 5020options for this are defined and restricted by the CPU used: Some CPU 5021models provide on-chip memory (like the IMMR area on MPC8xx and 5022MPC826x processors), on others (parts of) the data cache can be 5023locked as (mis-) used as memory, etc. 5024 5025 Chris Hallinan posted a good summary of these issues to the 5026 U-Boot mailing list: 5027 5028 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5029 From: "Chris Hallinan" <clh@net1plus.com> 5030 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5031 ... 5032 5033 Correct me if I'm wrong, folks, but the way I understand it 5034 is this: Using DCACHE as initial RAM for Stack, etc, does not 5035 require any physical RAM backing up the cache. The cleverness 5036 is that the cache is being used as a temporary supply of 5037 necessary storage before the SDRAM controller is setup. It's 5038 beyond the scope of this list to explain the details, but you 5039 can see how this works by studying the cache architecture and 5040 operation in the architecture and processor-specific manuals. 5041 5042 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5043 is another option for the system designer to use as an 5044 initial stack/RAM area prior to SDRAM being available. Either 5045 option should work for you. Using CS 4 should be fine if your 5046 board designers haven't used it for something that would 5047 cause you grief during the initial boot! It is frequently not 5048 used. 5049 5050 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5051 with your processor/board/system design. The default value 5052 you will find in any recent u-boot distribution in 5053 walnut.h should work for you. I'd set it to a value larger 5054 than your SDRAM module. If you have a 64MB SDRAM module, set 5055 it above 400_0000. Just make sure your board has no resources 5056 that are supposed to respond to that address! That code in 5057 start.S has been around a while and should work as is when 5058 you get the config right. 5059 5060 -Chris Hallinan 5061 DS4.COM, Inc. 5062 5063It is essential to remember this, since it has some impact on the C 5064code for the initialization procedures: 5065 5066* Initialized global data (data segment) is read-only. Do not attempt 5067 to write it. 5068 5069* Do not use any uninitialized global data (or implicitely initialized 5070 as zero data - BSS segment) at all - this is undefined, initiali- 5071 zation is performed later (when relocating to RAM). 5072 5073* Stack space is very limited. Avoid big data buffers or things like 5074 that. 5075 5076Having only the stack as writable memory limits means we cannot use 5077normal global data to share information beween the code. But it 5078turned out that the implementation of U-Boot can be greatly 5079simplified by making a global data structure (gd_t) available to all 5080functions. We could pass a pointer to this data as argument to _all_ 5081functions, but this would bloat the code. Instead we use a feature of 5082the GCC compiler (Global Register Variables) to share the data: we 5083place a pointer (gd) to the global data into a register which we 5084reserve for this purpose. 5085 5086When choosing a register for such a purpose we are restricted by the 5087relevant (E)ABI specifications for the current architecture, and by 5088GCC's implementation. 5089 5090For PowerPC, the following registers have specific use: 5091 R1: stack pointer 5092 R2: reserved for system use 5093 R3-R4: parameter passing and return values 5094 R5-R10: parameter passing 5095 R13: small data area pointer 5096 R30: GOT pointer 5097 R31: frame pointer 5098 5099 (U-Boot also uses R12 as internal GOT pointer. r12 5100 is a volatile register so r12 needs to be reset when 5101 going back and forth between asm and C) 5102 5103 ==> U-Boot will use R2 to hold a pointer to the global data 5104 5105 Note: on PPC, we could use a static initializer (since the 5106 address of the global data structure is known at compile time), 5107 but it turned out that reserving a register results in somewhat 5108 smaller code - although the code savings are not that big (on 5109 average for all boards 752 bytes for the whole U-Boot image, 5110 624 text + 127 data). 5111 5112On Blackfin, the normal C ABI (except for P3) is followed as documented here: 5113 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 5114 5115 ==> U-Boot will use P3 to hold a pointer to the global data 5116 5117On ARM, the following registers are used: 5118 5119 R0: function argument word/integer result 5120 R1-R3: function argument word 5121 R9: GOT pointer 5122 R10: stack limit (used only if stack checking if enabled) 5123 R11: argument (frame) pointer 5124 R12: temporary workspace 5125 R13: stack pointer 5126 R14: link register 5127 R15: program counter 5128 5129 ==> U-Boot will use R8 to hold a pointer to the global data 5130 5131On Nios II, the ABI is documented here: 5132 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5133 5134 ==> U-Boot will use gp to hold a pointer to the global data 5135 5136 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5137 to access small data sections, so gp is free. 5138 5139On NDS32, the following registers are used: 5140 5141 R0-R1: argument/return 5142 R2-R5: argument 5143 R15: temporary register for assembler 5144 R16: trampoline register 5145 R28: frame pointer (FP) 5146 R29: global pointer (GP) 5147 R30: link register (LP) 5148 R31: stack pointer (SP) 5149 PC: program counter (PC) 5150 5151 ==> U-Boot will use R10 to hold a pointer to the global data 5152 5153NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5154or current versions of GCC may "optimize" the code too much. 5155 5156Memory Management: 5157------------------ 5158 5159U-Boot runs in system state and uses physical addresses, i.e. the 5160MMU is not used either for address mapping nor for memory protection. 5161 5162The available memory is mapped to fixed addresses using the memory 5163controller. In this process, a contiguous block is formed for each 5164memory type (Flash, SDRAM, SRAM), even when it consists of several 5165physical memory banks. 5166 5167U-Boot is installed in the first 128 kB of the first Flash bank (on 5168TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5169booting and sizing and initializing DRAM, the code relocates itself 5170to the upper end of DRAM. Immediately below the U-Boot code some 5171memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5172configuration setting]. Below that, a structure with global Board 5173Info data is placed, followed by the stack (growing downward). 5174 5175Additionally, some exception handler code is copied to the low 8 kB 5176of DRAM (0x00000000 ... 0x00001FFF). 5177 5178So a typical memory configuration with 16 MB of DRAM could look like 5179this: 5180 5181 0x0000 0000 Exception Vector code 5182 : 5183 0x0000 1FFF 5184 0x0000 2000 Free for Application Use 5185 : 5186 : 5187 5188 : 5189 : 5190 0x00FB FF20 Monitor Stack (Growing downward) 5191 0x00FB FFAC Board Info Data and permanent copy of global data 5192 0x00FC 0000 Malloc Arena 5193 : 5194 0x00FD FFFF 5195 0x00FE 0000 RAM Copy of Monitor Code 5196 ... eventually: LCD or video framebuffer 5197 ... eventually: pRAM (Protected RAM - unchanged by reset) 5198 0x00FF FFFF [End of RAM] 5199 5200 5201System Initialization: 5202---------------------- 5203 5204In the reset configuration, U-Boot starts at the reset entry point 5205(on most PowerPC systems at address 0x00000100). Because of the reset 5206configuration for CS0# this is a mirror of the onboard Flash memory. 5207To be able to re-map memory U-Boot then jumps to its link address. 5208To be able to implement the initialization code in C, a (small!) 5209initial stack is set up in the internal Dual Ported RAM (in case CPUs 5210which provide such a feature like MPC8xx or MPC8260), or in a locked 5211part of the data cache. After that, U-Boot initializes the CPU core, 5212the caches and the SIU. 5213 5214Next, all (potentially) available memory banks are mapped using a 5215preliminary mapping. For example, we put them on 512 MB boundaries 5216(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5217on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5218programmed for SDRAM access. Using the temporary configuration, a 5219simple memory test is run that determines the size of the SDRAM 5220banks. 5221 5222When there is more than one SDRAM bank, and the banks are of 5223different size, the largest is mapped first. For equal size, the first 5224bank (CS2#) is mapped first. The first mapping is always for address 52250x00000000, with any additional banks following immediately to create 5226contiguous memory starting from 0. 5227 5228Then, the monitor installs itself at the upper end of the SDRAM area 5229and allocates memory for use by malloc() and for the global Board 5230Info data; also, the exception vector code is copied to the low RAM 5231pages, and the final stack is set up. 5232 5233Only after this relocation will you have a "normal" C environment; 5234until that you are restricted in several ways, mostly because you are 5235running from ROM, and because the code will have to be relocated to a 5236new address in RAM. 5237 5238 5239U-Boot Porting Guide: 5240---------------------- 5241 5242[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5243list, October 2002] 5244 5245 5246int main(int argc, char *argv[]) 5247{ 5248 sighandler_t no_more_time; 5249 5250 signal(SIGALRM, no_more_time); 5251 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5252 5253 if (available_money > available_manpower) { 5254 Pay consultant to port U-Boot; 5255 return 0; 5256 } 5257 5258 Download latest U-Boot source; 5259 5260 Subscribe to u-boot mailing list; 5261 5262 if (clueless) 5263 email("Hi, I am new to U-Boot, how do I get started?"); 5264 5265 while (learning) { 5266 Read the README file in the top level directory; 5267 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5268 Read applicable doc/*.README; 5269 Read the source, Luke; 5270 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5271 } 5272 5273 if (available_money > toLocalCurrency ($2500)) 5274 Buy a BDI3000; 5275 else 5276 Add a lot of aggravation and time; 5277 5278 if (a similar board exists) { /* hopefully... */ 5279 cp -a board/<similar> board/<myboard> 5280 cp include/configs/<similar>.h include/configs/<myboard>.h 5281 } else { 5282 Create your own board support subdirectory; 5283 Create your own board include/configs/<myboard>.h file; 5284 } 5285 Edit new board/<myboard> files 5286 Edit new include/configs/<myboard>.h 5287 5288 while (!accepted) { 5289 while (!running) { 5290 do { 5291 Add / modify source code; 5292 } until (compiles); 5293 Debug; 5294 if (clueless) 5295 email("Hi, I am having problems..."); 5296 } 5297 Send patch file to the U-Boot email list; 5298 if (reasonable critiques) 5299 Incorporate improvements from email list code review; 5300 else 5301 Defend code as written; 5302 } 5303 5304 return 0; 5305} 5306 5307void no_more_time (int sig) 5308{ 5309 hire_a_guru(); 5310} 5311 5312 5313Coding Standards: 5314----------------- 5315 5316All contributions to U-Boot should conform to the Linux kernel 5317coding style; see the file "Documentation/CodingStyle" and the script 5318"scripts/Lindent" in your Linux kernel source directory. 5319 5320Source files originating from a different project (for example the 5321MTD subsystem) are generally exempt from these guidelines and are not 5322reformated to ease subsequent migration to newer versions of those 5323sources. 5324 5325Please note that U-Boot is implemented in C (and to some small parts in 5326Assembler); no C++ is used, so please do not use C++ style comments (//) 5327in your code. 5328 5329Please also stick to the following formatting rules: 5330- remove any trailing white space 5331- use TAB characters for indentation and vertical alignment, not spaces 5332- make sure NOT to use DOS '\r\n' line feeds 5333- do not add more than 2 consecutive empty lines to source files 5334- do not add trailing empty lines to source files 5335 5336Submissions which do not conform to the standards may be returned 5337with a request to reformat the changes. 5338 5339 5340Submitting Patches: 5341------------------- 5342 5343Since the number of patches for U-Boot is growing, we need to 5344establish some rules. Submissions which do not conform to these rules 5345may be rejected, even when they contain important and valuable stuff. 5346 5347Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5348 5349Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5350see http://lists.denx.de/mailman/listinfo/u-boot 5351 5352When you send a patch, please include the following information with 5353it: 5354 5355* For bug fixes: a description of the bug and how your patch fixes 5356 this bug. Please try to include a way of demonstrating that the 5357 patch actually fixes something. 5358 5359* For new features: a description of the feature and your 5360 implementation. 5361 5362* A CHANGELOG entry as plaintext (separate from the patch) 5363 5364* For major contributions, your entry to the CREDITS file 5365 5366* When you add support for a new board, don't forget to add this 5367 board to the MAINTAINERS file, too. 5368 5369* If your patch adds new configuration options, don't forget to 5370 document these in the README file. 5371 5372* The patch itself. If you are using git (which is *strongly* 5373 recommended) you can easily generate the patch using the 5374 "git format-patch". If you then use "git send-email" to send it to 5375 the U-Boot mailing list, you will avoid most of the common problems 5376 with some other mail clients. 5377 5378 If you cannot use git, use "diff -purN OLD NEW". If your version of 5379 diff does not support these options, then get the latest version of 5380 GNU diff. 5381 5382 The current directory when running this command shall be the parent 5383 directory of the U-Boot source tree (i. e. please make sure that 5384 your patch includes sufficient directory information for the 5385 affected files). 5386 5387 We prefer patches as plain text. MIME attachments are discouraged, 5388 and compressed attachments must not be used. 5389 5390* If one logical set of modifications affects or creates several 5391 files, all these changes shall be submitted in a SINGLE patch file. 5392 5393* Changesets that contain different, unrelated modifications shall be 5394 submitted as SEPARATE patches, one patch per changeset. 5395 5396 5397Notes: 5398 5399* Before sending the patch, run the MAKEALL script on your patched 5400 source tree and make sure that no errors or warnings are reported 5401 for any of the boards. 5402 5403* Keep your modifications to the necessary minimum: A patch 5404 containing several unrelated changes or arbitrary reformats will be 5405 returned with a request to re-formatting / split it. 5406 5407* If you modify existing code, make sure that your new code does not 5408 add to the memory footprint of the code ;-) Small is beautiful! 5409 When adding new features, these should compile conditionally only 5410 (using #ifdef), and the resulting code with the new feature 5411 disabled must not need more memory than the old code without your 5412 modification. 5413 5414* Remember that there is a size limit of 100 kB per message on the 5415 u-boot mailing list. Bigger patches will be moderated. If they are 5416 reasonable and not too big, they will be acknowledged. But patches 5417 bigger than the size limit should be avoided. 5418