1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG and CREDITS files to find out 38who contributed the specific port. The boards.cfg file lists board 39maintainers. 40 41Note: There is no CHANGELOG file in the actual U-Boot source tree; 42it can be created dynamically from the Git log using: 43 44 make CHANGELOG 45 46 47Where to get help: 48================== 49 50In case you have questions about, problems with or contributions for 51U-Boot you should send a message to the U-Boot mailing list at 52<u-boot@lists.denx.de>. There is also an archive of previous traffic 53on the mailing list - please search the archive before asking FAQ's. 54Please see http://lists.denx.de/pipermail/u-boot and 55http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 56 57 58Where to get source code: 59========================= 60 61The U-Boot source code is maintained in the git repository at 62git://www.denx.de/git/u-boot.git ; you can browse it online at 63http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 64 65The "snapshot" links on this page allow you to download tarballs of 66any version you might be interested in. Official releases are also 67available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 68directory. 69 70Pre-built (and tested) images are available from 71ftp://ftp.denx.de/pub/u-boot/images/ 72 73 74Where we come from: 75=================== 76 77- start from 8xxrom sources 78- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 79- clean up code 80- make it easier to add custom boards 81- make it possible to add other [PowerPC] CPUs 82- extend functions, especially: 83 * Provide extended interface to Linux boot loader 84 * S-Record download 85 * network boot 86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 87- create ARMBoot project (http://sourceforge.net/projects/armboot) 88- add other CPU families (starting with ARM) 89- create U-Boot project (http://sourceforge.net/projects/u-boot) 90- current project page: see http://www.denx.de/wiki/U-Boot 91 92 93Names and Spelling: 94=================== 95 96The "official" name of this project is "Das U-Boot". The spelling 97"U-Boot" shall be used in all written text (documentation, comments 98in source files etc.). Example: 99 100 This is the README file for the U-Boot project. 101 102File names etc. shall be based on the string "u-boot". Examples: 103 104 include/asm-ppc/u-boot.h 105 106 #include <asm/u-boot.h> 107 108Variable names, preprocessor constants etc. shall be either based on 109the string "u_boot" or on "U_BOOT". Example: 110 111 U_BOOT_VERSION u_boot_logo 112 IH_OS_U_BOOT u_boot_hush_start 113 114 115Versioning: 116=========== 117 118Starting with the release in October 2008, the names of the releases 119were changed from numerical release numbers without deeper meaning 120into a time stamp based numbering. Regular releases are identified by 121names consisting of the calendar year and month of the release date. 122Additional fields (if present) indicate release candidates or bug fix 123releases in "stable" maintenance trees. 124 125Examples: 126 U-Boot v2009.11 - Release November 2009 127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release 129 130 131Directory Hierarchy: 132==================== 133 134/arch Architecture specific files 135 /arc Files generic to ARC architecture 136 /cpu CPU specific files 137 /arc700 Files specific to ARC 700 CPUs 138 /lib Architecture specific library files 139 /arm Files generic to ARM architecture 140 /cpu CPU specific files 141 /arm720t Files specific to ARM 720 CPUs 142 /arm920t Files specific to ARM 920 CPUs 143 /at91 Files specific to Atmel AT91RM9200 CPU 144 /imx Files specific to Freescale MC9328 i.MX CPUs 145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs 146 /arm926ejs Files specific to ARM 926 CPUs 147 /arm1136 Files specific to ARM 1136 CPUs 148 /pxa Files specific to Intel XScale PXA CPUs 149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs 150 /lib Architecture specific library files 151 /avr32 Files generic to AVR32 architecture 152 /cpu CPU specific files 153 /lib Architecture specific library files 154 /blackfin Files generic to Analog Devices Blackfin architecture 155 /cpu CPU specific files 156 /lib Architecture specific library files 157 /m68k Files generic to m68k architecture 158 /cpu CPU specific files 159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs 160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs 161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs 162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs 163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs 164 /lib Architecture specific library files 165 /microblaze Files generic to microblaze architecture 166 /cpu CPU specific files 167 /lib Architecture specific library files 168 /mips Files generic to MIPS architecture 169 /cpu CPU specific files 170 /mips32 Files specific to MIPS32 CPUs 171 /mips64 Files specific to MIPS64 CPUs 172 /lib Architecture specific library files 173 /nds32 Files generic to NDS32 architecture 174 /cpu CPU specific files 175 /n1213 Files specific to Andes Technology N1213 CPUs 176 /lib Architecture specific library files 177 /nios2 Files generic to Altera NIOS2 architecture 178 /cpu CPU specific files 179 /lib Architecture specific library files 180 /openrisc Files generic to OpenRISC architecture 181 /cpu CPU specific files 182 /lib Architecture specific library files 183 /powerpc Files generic to PowerPC architecture 184 /cpu CPU specific files 185 /mpc5xx Files specific to Freescale MPC5xx CPUs 186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs 187 /mpc8xx Files specific to Freescale MPC8xx CPUs 188 /mpc8260 Files specific to Freescale MPC8260 CPUs 189 /mpc85xx Files specific to Freescale MPC85xx CPUs 190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs 191 /lib Architecture specific library files 192 /sh Files generic to SH architecture 193 /cpu CPU specific files 194 /sh2 Files specific to sh2 CPUs 195 /sh3 Files specific to sh3 CPUs 196 /sh4 Files specific to sh4 CPUs 197 /lib Architecture specific library files 198 /sparc Files generic to SPARC architecture 199 /cpu CPU specific files 200 /leon2 Files specific to Gaisler LEON2 SPARC CPU 201 /leon3 Files specific to Gaisler LEON3 SPARC CPU 202 /lib Architecture specific library files 203 /x86 Files generic to x86 architecture 204 /cpu CPU specific files 205 /lib Architecture specific library files 206/api Machine/arch independent API for external apps 207/board Board dependent files 208/common Misc architecture independent functions 209/disk Code for disk drive partition handling 210/doc Documentation (don't expect too much) 211/drivers Commonly used device drivers 212/dts Contains Makefile for building internal U-Boot fdt. 213/examples Example code for standalone applications, etc. 214/fs Filesystem code (cramfs, ext2, jffs2, etc.) 215/include Header Files 216/lib Files generic to all architectures 217 /libfdt Library files to support flattened device trees 218 /lzma Library files to support LZMA decompression 219 /lzo Library files to support LZO decompression 220/net Networking code 221/post Power On Self Test 222/spl Secondary Program Loader framework 223/tools Tools to build S-Record or U-Boot images, etc. 224 225Software Configuration: 226======================= 227 228Configuration is usually done using C preprocessor defines; the 229rationale behind that is to avoid dead code whenever possible. 230 231There are two classes of configuration variables: 232 233* Configuration _OPTIONS_: 234 These are selectable by the user and have names beginning with 235 "CONFIG_". 236 237* Configuration _SETTINGS_: 238 These depend on the hardware etc. and should not be meddled with if 239 you don't know what you're doing; they have names beginning with 240 "CONFIG_SYS_". 241 242Later we will add a configuration tool - probably similar to or even 243identical to what's used for the Linux kernel. Right now, we have to 244do the configuration by hand, which means creating some symbolic 245links and editing some configuration files. We use the TQM8xxL boards 246as an example here. 247 248 249Selection of Processor Architecture and Board Type: 250--------------------------------------------------- 251 252For all supported boards there are ready-to-use default 253configurations available; just type "make <board_name>_defconfig". 254 255Example: For a TQM823L module type: 256 257 cd u-boot 258 make TQM823L_defconfig 259 260For the Cogent platform, you need to specify the CPU type as well; 261e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent 262directory according to the instructions in cogent/README. 263 264 265Sandbox Environment: 266-------------------- 267 268U-Boot can be built natively to run on a Linux host using the 'sandbox' 269board. This allows feature development which is not board- or architecture- 270specific to be undertaken on a native platform. The sandbox is also used to 271run some of U-Boot's tests. 272 273See board/sandbox/README.sandbox for more details. 274 275 276Board Initialisation Flow: 277-------------------------- 278 279This is the intended start-up flow for boards. This should apply for both 280SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL 281mostly uses a separate code path, but the funtion names and roles of each 282function are the same. Some boards or architectures may not conform to this. 283At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this. 284 285Execution starts with start.S with three functions called during init after 286that. The purpose and limitations of each is described below. 287 288lowlevel_init(): 289 - purpose: essential init to permit execution to reach board_init_f() 290 - no global_data or BSS 291 - there is no stack (ARMv7 may have one but it will soon be removed) 292 - must not set up SDRAM or use console 293 - must only do the bare minimum to allow execution to continue to 294 board_init_f() 295 - this is almost never needed 296 - return normally from this function 297 298board_init_f(): 299 - purpose: set up the machine ready for running board_init_r(): 300 i.e. SDRAM and serial UART 301 - global_data is available 302 - stack is in SRAM 303 - BSS is not available, so you cannot use global/static variables, 304 only stack variables and global_data 305 306 Non-SPL-specific notes: 307 - dram_init() is called to set up DRAM. If already done in SPL this 308 can do nothing 309 310 SPL-specific notes: 311 - you can override the entire board_init_f() function with your own 312 version as needed. 313 - preloader_console_init() can be called here in extremis 314 - should set up SDRAM, and anything needed to make the UART work 315 - these is no need to clear BSS, it will be done by crt0.S 316 - must return normally from this function (don't call board_init_r() 317 directly) 318 319Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 320this point the stack and global_data are relocated to below 321CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 322memory. 323 324board_init_r(): 325 - purpose: main execution, common code 326 - global_data is available 327 - SDRAM is available 328 - BSS is available, all static/global variables can be used 329 - execution eventually continues to main_loop() 330 331 Non-SPL-specific notes: 332 - U-Boot is relocated to the top of memory and is now running from 333 there. 334 335 SPL-specific notes: 336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 337 CONFIG_SPL_STACK_R_ADDR points into SDRAM 338 - preloader_console_init() can be called here - typically this is 339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a 340 spl_board_init() function containing this call 341 - loads U-Boot or (in falcon mode) Linux 342 343 344 345Configuration Options: 346---------------------- 347 348Configuration depends on the combination of board and CPU type; all 349such information is kept in a configuration file 350"include/configs/<board_name>.h". 351 352Example: For a TQM823L module, all configuration settings are in 353"include/configs/TQM823L.h". 354 355 356Many of the options are named exactly as the corresponding Linux 357kernel configuration options. The intention is to make it easier to 358build a config tool - later. 359 360 361The following options need to be configured: 362 363- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 364 365- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 366 367- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined) 368 Define exactly one, e.g. CONFIG_ATSTK1002 369 370- CPU Module Type: (if CONFIG_COGENT is defined) 371 Define exactly one of 372 CONFIG_CMA286_60_OLD 373--- FIXME --- not tested yet: 374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P, 375 CONFIG_CMA287_23, CONFIG_CMA287_50 376 377- Motherboard Type: (if CONFIG_COGENT is defined) 378 Define exactly one of 379 CONFIG_CMA101, CONFIG_CMA102 380 381- Motherboard I/O Modules: (if CONFIG_COGENT is defined) 382 Define one or more of 383 CONFIG_CMA302 384 385- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined) 386 Define one or more of 387 CONFIG_LCD_HEARTBEAT - update a character position on 388 the LCD display every second with 389 a "rotator" |\-/|\-/ 390 391- Marvell Family Member 392 CONFIG_SYS_MVFS - define it if you want to enable 393 multiple fs option at one time 394 for marvell soc family 395 396- 8xx CPU Options: (if using an MPC8xx CPU) 397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if 398 get_gclk_freq() cannot work 399 e.g. if there is no 32KHz 400 reference PIT/RTC clock 401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK 402 or XTAL/EXTAL) 403 404- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU): 405 CONFIG_SYS_8xx_CPUCLK_MIN 406 CONFIG_SYS_8xx_CPUCLK_MAX 407 CONFIG_8xx_CPUCLK_DEFAULT 408 See doc/README.MPC866 409 410 CONFIG_SYS_MEASURE_CPUCLK 411 412 Define this to measure the actual CPU clock instead 413 of relying on the correctness of the configured 414 values. Mostly useful for board bringup to make sure 415 the PLL is locked at the intended frequency. Note 416 that this requires a (stable) reference clock (32 kHz 417 RTC clock or CONFIG_SYS_8XX_XIN) 418 419 CONFIG_SYS_DELAYED_ICACHE 420 421 Define this option if you want to enable the 422 ICache only when Code runs from RAM. 423 424- 85xx CPU Options: 425 CONFIG_SYS_PPC64 426 427 Specifies that the core is a 64-bit PowerPC implementation (implements 428 the "64" category of the Power ISA). This is necessary for ePAPR 429 compliance, among other possible reasons. 430 431 CONFIG_SYS_FSL_TBCLK_DIV 432 433 Defines the core time base clock divider ratio compared to the 434 system clock. On most PQ3 devices this is 8, on newer QorIQ 435 devices it can be 16 or 32. The ratio varies from SoC to Soc. 436 437 CONFIG_SYS_FSL_PCIE_COMPAT 438 439 Defines the string to utilize when trying to match PCIe device 440 tree nodes for the given platform. 441 442 CONFIG_SYS_PPC_E500_DEBUG_TLB 443 444 Enables a temporary TLB entry to be used during boot to work 445 around limitations in e500v1 and e500v2 external debugger 446 support. This reduces the portions of the boot code where 447 breakpoints and single stepping do not work. The value of this 448 symbol should be set to the TLB1 entry to be used for this 449 purpose. 450 451 CONFIG_SYS_FSL_ERRATUM_A004510 452 453 Enables a workaround for erratum A004510. If set, 454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 456 457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 459 460 Defines one or two SoC revisions (low 8 bits of SVR) 461 for which the A004510 workaround should be applied. 462 463 The rest of SVR is either not relevant to the decision 464 of whether the erratum is present (e.g. p2040 versus 465 p2041) or is implied by the build target, which controls 466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 467 468 See Freescale App Note 4493 for more information about 469 this erratum. 470 471 CONFIG_A003399_NOR_WORKAROUND 472 Enables a workaround for IFC erratum A003399. It is only 473 required during NOR boot. 474 475 CONFIG_A008044_WORKAROUND 476 Enables a workaround for T1040/T1042 erratum A008044. It is only 477 required during NAND boot and valid for Rev 1.0 SoC revision 478 479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 480 481 This is the value to write into CCSR offset 0x18600 482 according to the A004510 workaround. 483 484 CONFIG_SYS_FSL_DSP_DDR_ADDR 485 This value denotes start offset of DDR memory which is 486 connected exclusively to the DSP cores. 487 488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 489 This value denotes start offset of M2 memory 490 which is directly connected to the DSP core. 491 492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 493 This value denotes start offset of M3 memory which is directly 494 connected to the DSP core. 495 496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 497 This value denotes start offset of DSP CCSR space. 498 499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 500 Single Source Clock is clocking mode present in some of FSL SoC's. 501 In this mode, a single differential clock is used to supply 502 clocks to the sysclock, ddrclock and usbclock. 503 504 CONFIG_SYS_CPC_REINIT_F 505 This CONFIG is defined when the CPC is configured as SRAM at the 506 time of U-boot entry and is required to be re-initialized. 507 508 CONFIG_DEEP_SLEEP 509 Indicates this SoC supports deep sleep feature. If deep sleep is 510 supported, core will start to execute uboot when wakes up. 511 512- Generic CPU options: 513 CONFIG_SYS_GENERIC_GLOBAL_DATA 514 Defines global data is initialized in generic board board_init_f(). 515 If this macro is defined, global data is created and cleared in 516 generic board board_init_f(). Without this macro, architecture/board 517 should initialize global data before calling board_init_f(). 518 519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 520 521 Defines the endianess of the CPU. Implementation of those 522 values is arch specific. 523 524 CONFIG_SYS_FSL_DDR 525 Freescale DDR driver in use. This type of DDR controller is 526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 527 SoCs. 528 529 CONFIG_SYS_FSL_DDR_ADDR 530 Freescale DDR memory-mapped register base. 531 532 CONFIG_SYS_FSL_DDR_EMU 533 Specify emulator support for DDR. Some DDR features such as 534 deskew training are not available. 535 536 CONFIG_SYS_FSL_DDRC_GEN1 537 Freescale DDR1 controller. 538 539 CONFIG_SYS_FSL_DDRC_GEN2 540 Freescale DDR2 controller. 541 542 CONFIG_SYS_FSL_DDRC_GEN3 543 Freescale DDR3 controller. 544 545 CONFIG_SYS_FSL_DDRC_GEN4 546 Freescale DDR4 controller. 547 548 CONFIG_SYS_FSL_DDRC_ARM_GEN3 549 Freescale DDR3 controller for ARM-based SoCs. 550 551 CONFIG_SYS_FSL_DDR1 552 Board config to use DDR1. It can be enabled for SoCs with 553 Freescale DDR1 or DDR2 controllers, depending on the board 554 implemetation. 555 556 CONFIG_SYS_FSL_DDR2 557 Board config to use DDR2. It can be eanbeld for SoCs with 558 Freescale DDR2 or DDR3 controllers, depending on the board 559 implementation. 560 561 CONFIG_SYS_FSL_DDR3 562 Board config to use DDR3. It can be enabled for SoCs with 563 Freescale DDR3 or DDR3L controllers. 564 565 CONFIG_SYS_FSL_DDR3L 566 Board config to use DDR3L. It can be enabled for SoCs with 567 DDR3L controllers. 568 569 CONFIG_SYS_FSL_DDR4 570 Board config to use DDR4. It can be enabled for SoCs with 571 DDR4 controllers. 572 573 CONFIG_SYS_FSL_IFC_BE 574 Defines the IFC controller register space as Big Endian 575 576 CONFIG_SYS_FSL_IFC_LE 577 Defines the IFC controller register space as Little Endian 578 579 CONFIG_SYS_FSL_PBL_PBI 580 It enables addition of RCW (Power on reset configuration) in built image. 581 Please refer doc/README.pblimage for more details 582 583 CONFIG_SYS_FSL_PBL_RCW 584 It adds PBI(pre-boot instructions) commands in u-boot build image. 585 PBI commands can be used to configure SoC before it starts the execution. 586 Please refer doc/README.pblimage for more details 587 588 CONFIG_SPL_FSL_PBL 589 It adds a target to create boot binary having SPL binary in PBI format 590 concatenated with u-boot binary. 591 592 CONFIG_SYS_FSL_DDR_BE 593 Defines the DDR controller register space as Big Endian 594 595 CONFIG_SYS_FSL_DDR_LE 596 Defines the DDR controller register space as Little Endian 597 598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 599 Physical address from the view of DDR controllers. It is the 600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 601 it could be different for ARM SoCs. 602 603 CONFIG_SYS_FSL_DDR_INTLV_256B 604 DDR controller interleaving on 256-byte. This is a special 605 interleaving mode, handled by Dickens for Freescale layerscape 606 SoCs with ARM core. 607 608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 609 Number of controllers used as main memory. 610 611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 612 Number of controllers used for other than main memory. 613 614 CONFIG_SYS_FSL_SEC_BE 615 Defines the SEC controller register space as Big Endian 616 617 CONFIG_SYS_FSL_SEC_LE 618 Defines the SEC controller register space as Little Endian 619 620- Intel Monahans options: 621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO 622 623 Defines the Monahans run mode to oscillator 624 ratio. Valid values are 8, 16, 24, 31. The core 625 frequency is this value multiplied by 13 MHz. 626 627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO 628 629 Defines the Monahans turbo mode to oscillator 630 ratio. Valid values are 1 (default if undefined) and 631 2. The core frequency as calculated above is multiplied 632 by this value. 633 634- MIPS CPU options: 635 CONFIG_SYS_INIT_SP_OFFSET 636 637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 638 pointer. This is needed for the temporary stack before 639 relocation. 640 641 CONFIG_SYS_MIPS_CACHE_MODE 642 643 Cache operation mode for the MIPS CPU. 644 See also arch/mips/include/asm/mipsregs.h. 645 Possible values are: 646 CONF_CM_CACHABLE_NO_WA 647 CONF_CM_CACHABLE_WA 648 CONF_CM_UNCACHED 649 CONF_CM_CACHABLE_NONCOHERENT 650 CONF_CM_CACHABLE_CE 651 CONF_CM_CACHABLE_COW 652 CONF_CM_CACHABLE_CUW 653 CONF_CM_CACHABLE_ACCELERATED 654 655 CONFIG_SYS_XWAY_EBU_BOOTCFG 656 657 Special option for Lantiq XWAY SoCs for booting from NOR flash. 658 See also arch/mips/cpu/mips32/start.S. 659 660 CONFIG_XWAY_SWAP_BYTES 661 662 Enable compilation of tools/xway-swap-bytes needed for Lantiq 663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 664 be swapped if a flash programmer is used. 665 666- ARM options: 667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 668 669 Select high exception vectors of the ARM core, e.g., do not 670 clear the V bit of the c1 register of CP15. 671 672 CONFIG_SYS_THUMB_BUILD 673 674 Use this flag to build U-Boot using the Thumb instruction 675 set for ARM architectures. Thumb instruction set provides 676 better code density. For ARM architectures that support 677 Thumb2 this flag will result in Thumb2 code generated by 678 GCC. 679 680 CONFIG_ARM_ERRATA_716044 681 CONFIG_ARM_ERRATA_742230 682 CONFIG_ARM_ERRATA_743622 683 CONFIG_ARM_ERRATA_751472 684 CONFIG_ARM_ERRATA_794072 685 CONFIG_ARM_ERRATA_761320 686 687 If set, the workarounds for these ARM errata are applied early 688 during U-Boot startup. Note that these options force the 689 workarounds to be applied; no CPU-type/version detection 690 exists, unlike the similar options in the Linux kernel. Do not 691 set these options unless they apply! 692 693 COUNTER_FREQUENCY 694 Generic timer clock source frequency. 695 696 COUNTER_FREQUENCY_REAL 697 Generic timer clock source frequency if the real clock is 698 different from COUNTER_FREQUENCY, and can only be determined 699 at run time. 700 701 NOTE: The following can be machine specific errata. These 702 do have ability to provide rudimentary version and machine 703 specific checks, but expect no product checks. 704 CONFIG_ARM_ERRATA_430973 705 CONFIG_ARM_ERRATA_454179 706 CONFIG_ARM_ERRATA_621766 707 CONFIG_ARM_ERRATA_798870 708 CONFIG_ARM_ERRATA_801819 709 710- Tegra SoC options: 711 CONFIG_TEGRA_SUPPORT_NON_SECURE 712 713 Support executing U-Boot in non-secure (NS) mode. Certain 714 impossible actions will be skipped if the CPU is in NS mode, 715 such as ARM architectural timer initialization. 716 717- Linux Kernel Interface: 718 CONFIG_CLOCKS_IN_MHZ 719 720 U-Boot stores all clock information in Hz 721 internally. For binary compatibility with older Linux 722 kernels (which expect the clocks passed in the 723 bd_info data to be in MHz) the environment variable 724 "clocks_in_mhz" can be defined so that U-Boot 725 converts clock data to MHZ before passing it to the 726 Linux kernel. 727 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 728 "clocks_in_mhz=1" is automatically included in the 729 default environment. 730 731 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 732 733 When transferring memsize parameter to Linux, some versions 734 expect it to be in bytes, others in MB. 735 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 736 737 CONFIG_OF_LIBFDT 738 739 New kernel versions are expecting firmware settings to be 740 passed using flattened device trees (based on open firmware 741 concepts). 742 743 CONFIG_OF_LIBFDT 744 * New libfdt-based support 745 * Adds the "fdt" command 746 * The bootm command automatically updates the fdt 747 748 OF_CPU - The proper name of the cpus node (only required for 749 MPC512X and MPC5xxx based boards). 750 OF_SOC - The proper name of the soc node (only required for 751 MPC512X and MPC5xxx based boards). 752 OF_TBCLK - The timebase frequency. 753 OF_STDOUT_PATH - The path to the console device 754 755 boards with QUICC Engines require OF_QE to set UCC MAC 756 addresses 757 758 CONFIG_OF_BOARD_SETUP 759 760 Board code has addition modification that it wants to make 761 to the flat device tree before handing it off to the kernel 762 763 CONFIG_OF_SYSTEM_SETUP 764 765 Other code has addition modification that it wants to make 766 to the flat device tree before handing it off to the kernel. 767 This causes ft_system_setup() to be called before booting 768 the kernel. 769 770 CONFIG_OF_BOOT_CPU 771 772 This define fills in the correct boot CPU in the boot 773 param header, the default value is zero if undefined. 774 775 CONFIG_OF_IDE_FIXUP 776 777 U-Boot can detect if an IDE device is present or not. 778 If not, and this new config option is activated, U-Boot 779 removes the ATA node from the DTS before booting Linux, 780 so the Linux IDE driver does not probe the device and 781 crash. This is needed for buggy hardware (uc101) where 782 no pull down resistor is connected to the signal IDE5V_DD7. 783 784 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 785 786 This setting is mandatory for all boards that have only one 787 machine type and must be used to specify the machine type 788 number as it appears in the ARM machine registry 789 (see http://www.arm.linux.org.uk/developer/machines/). 790 Only boards that have multiple machine types supported 791 in a single configuration file and the machine type is 792 runtime discoverable, do not have to use this setting. 793 794- vxWorks boot parameters: 795 796 bootvx constructs a valid bootline using the following 797 environments variables: bootfile, ipaddr, serverip, hostname. 798 It loads the vxWorks image pointed bootfile. 799 800 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name 801 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address 802 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server 803 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters 804 805 CONFIG_SYS_VXWORKS_ADD_PARAMS 806 807 Add it at the end of the bootline. E.g "u=username pw=secret" 808 809 Note: If a "bootargs" environment is defined, it will overwride 810 the defaults discussed just above. 811 812- Cache Configuration: 813 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 814 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 815 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 816 817- Cache Configuration for ARM: 818 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 819 controller 820 CONFIG_SYS_PL310_BASE - Physical base address of PL310 821 controller register space 822 823- Serial Ports: 824 CONFIG_PL010_SERIAL 825 826 Define this if you want support for Amba PrimeCell PL010 UARTs. 827 828 CONFIG_PL011_SERIAL 829 830 Define this if you want support for Amba PrimeCell PL011 UARTs. 831 832 CONFIG_PL011_CLOCK 833 834 If you have Amba PrimeCell PL011 UARTs, set this variable to 835 the clock speed of the UARTs. 836 837 CONFIG_PL01x_PORTS 838 839 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 840 define this to a list of base addresses for each (supported) 841 port. See e.g. include/configs/versatile.h 842 843 CONFIG_SERIAL_HW_FLOW_CONTROL 844 845 Define this variable to enable hw flow control in serial driver. 846 Current user of this option is drivers/serial/nsl16550.c driver 847 848- Console Interface: 849 Depending on board, define exactly one serial port 850 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2, 851 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial 852 console by defining CONFIG_8xx_CONS_NONE 853 854 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 855 port routines must be defined elsewhere 856 (i.e. serial_init(), serial_getc(), ...) 857 858 CONFIG_CFB_CONSOLE 859 Enables console device for a color framebuffer. Needs following 860 defines (cf. smiLynxEM, i8042) 861 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation 862 (default big endian) 863 VIDEO_HW_RECTFILL graphic chip supports 864 rectangle fill 865 (cf. smiLynxEM) 866 VIDEO_HW_BITBLT graphic chip supports 867 bit-blit (cf. smiLynxEM) 868 VIDEO_VISIBLE_COLS visible pixel columns 869 (cols=pitch) 870 VIDEO_VISIBLE_ROWS visible pixel rows 871 VIDEO_PIXEL_SIZE bytes per pixel 872 VIDEO_DATA_FORMAT graphic data format 873 (0-5, cf. cfb_console.c) 874 VIDEO_FB_ADRS framebuffer address 875 VIDEO_KBD_INIT_FCT keyboard int fct 876 (i.e. i8042_kbd_init()) 877 VIDEO_TSTC_FCT test char fct 878 (i.e. i8042_tstc) 879 VIDEO_GETC_FCT get char fct 880 (i.e. i8042_getc) 881 CONFIG_CONSOLE_CURSOR cursor drawing on/off 882 (requires blink timer 883 cf. i8042.c) 884 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c) 885 CONFIG_CONSOLE_TIME display time/date info in 886 upper right corner 887 (requires CONFIG_CMD_DATE) 888 CONFIG_VIDEO_LOGO display Linux logo in 889 upper left corner 890 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of 891 linux_logo.h for logo. 892 Requires CONFIG_VIDEO_LOGO 893 CONFIG_CONSOLE_EXTRA_INFO 894 additional board info beside 895 the logo 896 897 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support 898 a limited number of ANSI escape sequences (cursor control, 899 erase functions and limited graphics rendition control). 900 901 When CONFIG_CFB_CONSOLE is defined, video console is 902 default i/o. Serial console can be forced with 903 environment 'console=serial'. 904 905 When CONFIG_SILENT_CONSOLE is defined, all console 906 messages (by U-Boot and Linux!) can be silenced with 907 the "silent" environment variable. See 908 doc/README.silent for more information. 909 910 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default 911 is 0x00. 912 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default 913 is 0xa0. 914 915- Console Baudrate: 916 CONFIG_BAUDRATE - in bps 917 Select one of the baudrates listed in 918 CONFIG_SYS_BAUDRATE_TABLE, see below. 919 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 920 921- Console Rx buffer length 922 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 923 the maximum receive buffer length for the SMC. 924 This option is actual only for 82xx and 8xx possible. 925 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 926 must be defined, to setup the maximum idle timeout for 927 the SMC. 928 929- Pre-Console Buffer: 930 Prior to the console being initialised (i.e. serial UART 931 initialised etc) all console output is silently discarded. 932 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to 933 buffer any console messages prior to the console being 934 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ 935 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is 936 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ 937 bytes are output before the console is initialised, the 938 earlier bytes are discarded. 939 940 Note that when printing the buffer a copy is made on the 941 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack. 942 943 'Sane' compilers will generate smaller code if 944 CONFIG_PRE_CON_BUF_SZ is a power of 2 945 946- Safe printf() functions 947 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of 948 the printf() functions. These are defined in 949 include/vsprintf.h and include snprintf(), vsnprintf() and 950 so on. Code size increase is approximately 300-500 bytes. 951 If this option is not given then these functions will 952 silently discard their buffer size argument - this means 953 you are not getting any overflow checking in this case. 954 955- Boot Delay: CONFIG_BOOTDELAY - in seconds 956 Delay before automatically booting the default image; 957 set to -1 to disable autoboot. 958 set to -2 to autoboot with no delay and not check for abort 959 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined). 960 961 See doc/README.autoboot for these options that 962 work with CONFIG_BOOTDELAY. None are required. 963 CONFIG_BOOT_RETRY_TIME 964 CONFIG_BOOT_RETRY_MIN 965 CONFIG_AUTOBOOT_KEYED 966 CONFIG_AUTOBOOT_PROMPT 967 CONFIG_AUTOBOOT_DELAY_STR 968 CONFIG_AUTOBOOT_STOP_STR 969 CONFIG_ZERO_BOOTDELAY_CHECK 970 CONFIG_RESET_TO_RETRY 971 972- Autoboot Command: 973 CONFIG_BOOTCOMMAND 974 Only needed when CONFIG_BOOTDELAY is enabled; 975 define a command string that is automatically executed 976 when no character is read on the console interface 977 within "Boot Delay" after reset. 978 979 CONFIG_BOOTARGS 980 This can be used to pass arguments to the bootm 981 command. The value of CONFIG_BOOTARGS goes into the 982 environment value "bootargs". 983 984 CONFIG_RAMBOOT and CONFIG_NFSBOOT 985 The value of these goes into the environment as 986 "ramboot" and "nfsboot" respectively, and can be used 987 as a convenience, when switching between booting from 988 RAM and NFS. 989 990- Bootcount: 991 CONFIG_BOOTCOUNT_LIMIT 992 Implements a mechanism for detecting a repeating reboot 993 cycle, see: 994 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 995 996 CONFIG_BOOTCOUNT_ENV 997 If no softreset save registers are found on the hardware 998 "bootcount" is stored in the environment. To prevent a 999 saveenv on all reboots, the environment variable 1000 "upgrade_available" is used. If "upgrade_available" is 1001 0, "bootcount" is always 0, if "upgrade_available" is 1002 1 "bootcount" is incremented in the environment. 1003 So the Userspace Applikation must set the "upgrade_available" 1004 and "bootcount" variable to 0, if a boot was successfully. 1005 1006- Pre-Boot Commands: 1007 CONFIG_PREBOOT 1008 1009 When this option is #defined, the existence of the 1010 environment variable "preboot" will be checked 1011 immediately before starting the CONFIG_BOOTDELAY 1012 countdown and/or running the auto-boot command resp. 1013 entering interactive mode. 1014 1015 This feature is especially useful when "preboot" is 1016 automatically generated or modified. For an example 1017 see the LWMON board specific code: here "preboot" is 1018 modified when the user holds down a certain 1019 combination of keys on the (special) keyboard when 1020 booting the systems 1021 1022- Serial Download Echo Mode: 1023 CONFIG_LOADS_ECHO 1024 If defined to 1, all characters received during a 1025 serial download (using the "loads" command) are 1026 echoed back. This might be needed by some terminal 1027 emulations (like "cu"), but may as well just take 1028 time on others. This setting #define's the initial 1029 value of the "loads_echo" environment variable. 1030 1031- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 1032 CONFIG_KGDB_BAUDRATE 1033 Select one of the baudrates listed in 1034 CONFIG_SYS_BAUDRATE_TABLE, see below. 1035 1036- Monitor Functions: 1037 Monitor commands can be included or excluded 1038 from the build by using the #include files 1039 <config_cmd_all.h> and #undef'ing unwanted 1040 commands, or adding #define's for wanted commands. 1041 1042 The default command configuration includes all commands 1043 except those marked below with a "*". 1044 1045 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 1046 CONFIG_CMD_ASKENV * ask for env variable 1047 CONFIG_CMD_BDI bdinfo 1048 CONFIG_CMD_BEDBUG * Include BedBug Debugger 1049 CONFIG_CMD_BMP * BMP support 1050 CONFIG_CMD_BSP * Board specific commands 1051 CONFIG_CMD_BOOTD bootd 1052 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 1053 CONFIG_CMD_CACHE * icache, dcache 1054 CONFIG_CMD_CLK * clock command support 1055 CONFIG_CMD_CONSOLE coninfo 1056 CONFIG_CMD_CRC32 * crc32 1057 CONFIG_CMD_DATE * support for RTC, date/time... 1058 CONFIG_CMD_DHCP * DHCP support 1059 CONFIG_CMD_DIAG * Diagnostics 1060 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands 1061 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command 1062 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd 1063 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command 1064 CONFIG_CMD_DTT * Digital Therm and Thermostat 1065 CONFIG_CMD_ECHO echo arguments 1066 CONFIG_CMD_EDITENV edit env variable 1067 CONFIG_CMD_EEPROM * EEPROM read/write support 1068 CONFIG_CMD_ELF * bootelf, bootvx 1069 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks 1070 CONFIG_CMD_ENV_FLAGS * display details about env flags 1071 CONFIG_CMD_ENV_EXISTS * check existence of env variable 1072 CONFIG_CMD_EXPORTENV * export the environment 1073 CONFIG_CMD_EXT2 * ext2 command support 1074 CONFIG_CMD_EXT4 * ext4 command support 1075 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 1076 that work for multiple fs types 1077 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 1078 CONFIG_CMD_SAVEENV saveenv 1079 CONFIG_CMD_FDC * Floppy Disk Support 1080 CONFIG_CMD_FAT * FAT command support 1081 CONFIG_CMD_FLASH flinfo, erase, protect 1082 CONFIG_CMD_FPGA FPGA device initialization support 1083 CONFIG_CMD_FUSE * Device fuse support 1084 CONFIG_CMD_GETTIME * Get time since boot 1085 CONFIG_CMD_GO * the 'go' command (exec code) 1086 CONFIG_CMD_GREPENV * search environment 1087 CONFIG_CMD_HASH * calculate hash / digest 1088 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control 1089 CONFIG_CMD_I2C * I2C serial bus support 1090 CONFIG_CMD_IDE * IDE harddisk support 1091 CONFIG_CMD_IMI iminfo 1092 CONFIG_CMD_IMLS List all images found in NOR flash 1093 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 1094 CONFIG_CMD_IMMAP * IMMR dump support 1095 CONFIG_CMD_IOTRACE * I/O tracing for debugging 1096 CONFIG_CMD_IMPORTENV * import an environment 1097 CONFIG_CMD_INI * import data from an ini file into the env 1098 CONFIG_CMD_IRQ * irqinfo 1099 CONFIG_CMD_ITEST Integer/string test of 2 values 1100 CONFIG_CMD_JFFS2 * JFFS2 Support 1101 CONFIG_CMD_KGDB * kgdb 1102 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 1103 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 1104 (169.254.*.*) 1105 CONFIG_CMD_LOADB loadb 1106 CONFIG_CMD_LOADS loads 1107 CONFIG_CMD_MD5SUM * print md5 message digest 1108 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 1109 CONFIG_CMD_MEMINFO * Display detailed memory information 1110 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 1111 loop, loopw 1112 CONFIG_CMD_MEMTEST * mtest 1113 CONFIG_CMD_MISC Misc functions like sleep etc 1114 CONFIG_CMD_MMC * MMC memory mapped support 1115 CONFIG_CMD_MII * MII utility commands 1116 CONFIG_CMD_MTDPARTS * MTD partition support 1117 CONFIG_CMD_NAND * NAND support 1118 CONFIG_CMD_NET bootp, tftpboot, rarpboot 1119 CONFIG_CMD_NFS NFS support 1120 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 1121 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 1122 CONFIG_CMD_PCI * pciinfo 1123 CONFIG_CMD_PCMCIA * PCMCIA support 1124 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 1125 host 1126 CONFIG_CMD_PORTIO * Port I/O 1127 CONFIG_CMD_READ * Read raw data from partition 1128 CONFIG_CMD_REGINFO * Register dump 1129 CONFIG_CMD_RUN run command in env variable 1130 CONFIG_CMD_SANDBOX * sb command to access sandbox features 1131 CONFIG_CMD_SAVES * save S record dump 1132 CONFIG_CMD_SCSI * SCSI Support 1133 CONFIG_CMD_SDRAM * print SDRAM configuration information 1134 (requires CONFIG_CMD_I2C) 1135 CONFIG_CMD_SETGETDCR Support for DCR Register access 1136 (4xx only) 1137 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 1138 CONFIG_CMD_SHA1SUM * print sha1 memory digest 1139 (requires CONFIG_CMD_MEMORY) 1140 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 1141 CONFIG_CMD_SOURCE "source" command Support 1142 CONFIG_CMD_SPI * SPI serial bus support 1143 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 1144 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 1145 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 1146 CONFIG_CMD_TIMER * access to the system tick timer 1147 CONFIG_CMD_USB * USB support 1148 CONFIG_CMD_CDP * Cisco Discover Protocol support 1149 CONFIG_CMD_MFSL * Microblaze FSL support 1150 CONFIG_CMD_XIMG Load part of Multi Image 1151 CONFIG_CMD_UUID * Generate random UUID or GUID string 1152 1153 EXAMPLE: If you want all functions except of network 1154 support you can write: 1155 1156 #include "config_cmd_all.h" 1157 #undef CONFIG_CMD_NET 1158 1159 Other Commands: 1160 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 1161 1162 Note: Don't enable the "icache" and "dcache" commands 1163 (configuration option CONFIG_CMD_CACHE) unless you know 1164 what you (and your U-Boot users) are doing. Data 1165 cache cannot be enabled on systems like the 8xx or 1166 8260 (where accesses to the IMMR region must be 1167 uncached), and it cannot be disabled on all other 1168 systems where we (mis-) use the data cache to hold an 1169 initial stack and some data. 1170 1171 1172 XXX - this list needs to get updated! 1173 1174- Regular expression support: 1175 CONFIG_REGEX 1176 If this variable is defined, U-Boot is linked against 1177 the SLRE (Super Light Regular Expression) library, 1178 which adds regex support to some commands, as for 1179 example "env grep" and "setexpr". 1180 1181- Device tree: 1182 CONFIG_OF_CONTROL 1183 If this variable is defined, U-Boot will use a device tree 1184 to configure its devices, instead of relying on statically 1185 compiled #defines in the board file. This option is 1186 experimental and only available on a few boards. The device 1187 tree is available in the global data as gd->fdt_blob. 1188 1189 U-Boot needs to get its device tree from somewhere. This can 1190 be done using one of the two options below: 1191 1192 CONFIG_OF_EMBED 1193 If this variable is defined, U-Boot will embed a device tree 1194 binary in its image. This device tree file should be in the 1195 board directory and called <soc>-<board>.dts. The binary file 1196 is then picked up in board_init_f() and made available through 1197 the global data structure as gd->blob. 1198 1199 CONFIG_OF_SEPARATE 1200 If this variable is defined, U-Boot will build a device tree 1201 binary. It will be called u-boot.dtb. Architecture-specific 1202 code will locate it at run-time. Generally this works by: 1203 1204 cat u-boot.bin u-boot.dtb >image.bin 1205 1206 and in fact, U-Boot does this for you, creating a file called 1207 u-boot-dtb.bin which is useful in the common case. You can 1208 still use the individual files if you need something more 1209 exotic. 1210 1211- Watchdog: 1212 CONFIG_WATCHDOG 1213 If this variable is defined, it enables watchdog 1214 support for the SoC. There must be support in the SoC 1215 specific code for a watchdog. For the 8xx and 8260 1216 CPUs, the SIU Watchdog feature is enabled in the SYPCR 1217 register. When supported for a specific SoC is 1218 available, then no further board specific code should 1219 be needed to use it. 1220 1221 CONFIG_HW_WATCHDOG 1222 When using a watchdog circuitry external to the used 1223 SoC, then define this variable and provide board 1224 specific code for the "hw_watchdog_reset" function. 1225 1226 CONFIG_AT91_HW_WDT_TIMEOUT 1227 specify the timeout in seconds. default 2 seconds. 1228 1229- U-Boot Version: 1230 CONFIG_VERSION_VARIABLE 1231 If this variable is defined, an environment variable 1232 named "ver" is created by U-Boot showing the U-Boot 1233 version as printed by the "version" command. 1234 Any change to this variable will be reverted at the 1235 next reset. 1236 1237- Real-Time Clock: 1238 1239 When CONFIG_CMD_DATE is selected, the type of the RTC 1240 has to be selected, too. Define exactly one of the 1241 following options: 1242 1243 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx 1244 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 1245 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 1246 CONFIG_RTC_MC146818 - use MC146818 RTC 1247 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 1248 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 1249 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 1250 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 1251 CONFIG_RTC_DS164x - use Dallas DS164x RTC 1252 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 1253 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 1254 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 1255 CONFIG_SYS_RV3029_TCR - enable trickle charger on 1256 RV3029 RTC. 1257 1258 Note that if the RTC uses I2C, then the I2C interface 1259 must also be configured. See I2C Support, below. 1260 1261- GPIO Support: 1262 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 1263 1264 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 1265 chip-ngpio pairs that tell the PCA953X driver the number of 1266 pins supported by a particular chip. 1267 1268 Note that if the GPIO device uses I2C, then the I2C interface 1269 must also be configured. See I2C Support, below. 1270 1271- I/O tracing: 1272 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1273 accesses and can checksum them or write a list of them out 1274 to memory. See the 'iotrace' command for details. This is 1275 useful for testing device drivers since it can confirm that 1276 the driver behaves the same way before and after a code 1277 change. Currently this is supported on sandbox and arm. To 1278 add support for your architecture, add '#include <iotrace.h>' 1279 to the bottom of arch/<arch>/include/asm/io.h and test. 1280 1281 Example output from the 'iotrace stats' command is below. 1282 Note that if the trace buffer is exhausted, the checksum will 1283 still continue to operate. 1284 1285 iotrace is enabled 1286 Start: 10000000 (buffer start address) 1287 Size: 00010000 (buffer size) 1288 Offset: 00000120 (current buffer offset) 1289 Output: 10000120 (start + offset) 1290 Count: 00000018 (number of trace records) 1291 CRC32: 9526fb66 (CRC32 of all trace records) 1292 1293- Timestamp Support: 1294 1295 When CONFIG_TIMESTAMP is selected, the timestamp 1296 (date and time) of an image is printed by image 1297 commands like bootm or iminfo. This option is 1298 automatically enabled when you select CONFIG_CMD_DATE . 1299 1300- Partition Labels (disklabels) Supported: 1301 Zero or more of the following: 1302 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1303 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the 1304 Intel architecture, USB sticks, etc. 1305 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1306 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1307 bootloader. Note 2TB partition limit; see 1308 disk/part_efi.c 1309 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1310 1311 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or 1312 CONFIG_CMD_SCSI) you must configure support for at 1313 least one non-MTD partition type as well. 1314 1315- IDE Reset method: 1316 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1317 board configurations files but used nowhere! 1318 1319 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1320 be performed by calling the function 1321 ide_set_reset(int reset) 1322 which has to be defined in a board specific file 1323 1324- ATAPI Support: 1325 CONFIG_ATAPI 1326 1327 Set this to enable ATAPI support. 1328 1329- LBA48 Support 1330 CONFIG_LBA48 1331 1332 Set this to enable support for disks larger than 137GB 1333 Also look at CONFIG_SYS_64BIT_LBA. 1334 Whithout these , LBA48 support uses 32bit variables and will 'only' 1335 support disks up to 2.1TB. 1336 1337 CONFIG_SYS_64BIT_LBA: 1338 When enabled, makes the IDE subsystem use 64bit sector addresses. 1339 Default is 32bit. 1340 1341- SCSI Support: 1342 At the moment only there is only support for the 1343 SYM53C8XX SCSI controller; define 1344 CONFIG_SCSI_SYM53C8XX to enable it. 1345 1346 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1347 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1348 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1349 maximum numbers of LUNs, SCSI ID's and target 1350 devices. 1351 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1352 1353 The environment variable 'scsidevs' is set to the number of 1354 SCSI devices found during the last scan. 1355 1356- NETWORK Support (PCI): 1357 CONFIG_E1000 1358 Support for Intel 8254x/8257x gigabit chips. 1359 1360 CONFIG_E1000_SPI 1361 Utility code for direct access to the SPI bus on Intel 8257x. 1362 This does not do anything useful unless you set at least one 1363 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1364 1365 CONFIG_E1000_SPI_GENERIC 1366 Allow generic access to the SPI bus on the Intel 8257x, for 1367 example with the "sspi" command. 1368 1369 CONFIG_CMD_E1000 1370 Management command for E1000 devices. When used on devices 1371 with SPI support you can reprogram the EEPROM from U-Boot. 1372 1373 CONFIG_EEPRO100 1374 Support for Intel 82557/82559/82559ER chips. 1375 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1376 write routine for first time initialisation. 1377 1378 CONFIG_TULIP 1379 Support for Digital 2114x chips. 1380 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1381 modem chip initialisation (KS8761/QS6611). 1382 1383 CONFIG_NATSEMI 1384 Support for National dp83815 chips. 1385 1386 CONFIG_NS8382X 1387 Support for National dp8382[01] gigabit chips. 1388 1389- NETWORK Support (other): 1390 1391 CONFIG_DRIVER_AT91EMAC 1392 Support for AT91RM9200 EMAC. 1393 1394 CONFIG_RMII 1395 Define this to use reduced MII inteface 1396 1397 CONFIG_DRIVER_AT91EMAC_QUIET 1398 If this defined, the driver is quiet. 1399 The driver doen't show link status messages. 1400 1401 CONFIG_CALXEDA_XGMAC 1402 Support for the Calxeda XGMAC device 1403 1404 CONFIG_LAN91C96 1405 Support for SMSC's LAN91C96 chips. 1406 1407 CONFIG_LAN91C96_BASE 1408 Define this to hold the physical address 1409 of the LAN91C96's I/O space 1410 1411 CONFIG_LAN91C96_USE_32_BIT 1412 Define this to enable 32 bit addressing 1413 1414 CONFIG_SMC91111 1415 Support for SMSC's LAN91C111 chip 1416 1417 CONFIG_SMC91111_BASE 1418 Define this to hold the physical address 1419 of the device (I/O space) 1420 1421 CONFIG_SMC_USE_32_BIT 1422 Define this if data bus is 32 bits 1423 1424 CONFIG_SMC_USE_IOFUNCS 1425 Define this to use i/o functions instead of macros 1426 (some hardware wont work with macros) 1427 1428 CONFIG_DRIVER_TI_EMAC 1429 Support for davinci emac 1430 1431 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1432 Define this if you have more then 3 PHYs. 1433 1434 CONFIG_FTGMAC100 1435 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1436 1437 CONFIG_FTGMAC100_EGIGA 1438 Define this to use GE link update with gigabit PHY. 1439 Define this if FTGMAC100 is connected to gigabit PHY. 1440 If your system has 10/100 PHY only, it might not occur 1441 wrong behavior. Because PHY usually return timeout or 1442 useless data when polling gigabit status and gigabit 1443 control registers. This behavior won't affect the 1444 correctnessof 10/100 link speed update. 1445 1446 CONFIG_SMC911X 1447 Support for SMSC's LAN911x and LAN921x chips 1448 1449 CONFIG_SMC911X_BASE 1450 Define this to hold the physical address 1451 of the device (I/O space) 1452 1453 CONFIG_SMC911X_32_BIT 1454 Define this if data bus is 32 bits 1455 1456 CONFIG_SMC911X_16_BIT 1457 Define this if data bus is 16 bits. If your processor 1458 automatically converts one 32 bit word to two 16 bit 1459 words you may also try CONFIG_SMC911X_32_BIT. 1460 1461 CONFIG_SH_ETHER 1462 Support for Renesas on-chip Ethernet controller 1463 1464 CONFIG_SH_ETHER_USE_PORT 1465 Define the number of ports to be used 1466 1467 CONFIG_SH_ETHER_PHY_ADDR 1468 Define the ETH PHY's address 1469 1470 CONFIG_SH_ETHER_CACHE_WRITEBACK 1471 If this option is set, the driver enables cache flush. 1472 1473- PWM Support: 1474 CONFIG_PWM_IMX 1475 Support for PWM modul on the imx6. 1476 1477- TPM Support: 1478 CONFIG_TPM 1479 Support TPM devices. 1480 1481 CONFIG_TPM_TIS_I2C 1482 Support for i2c bus TPM devices. Only one device 1483 per system is supported at this time. 1484 1485 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1486 Define the burst count bytes upper limit 1487 1488 CONFIG_TPM_ATMEL_TWI 1489 Support for Atmel TWI TPM device. Requires I2C support. 1490 1491 CONFIG_TPM_TIS_LPC 1492 Support for generic parallel port TPM devices. Only one device 1493 per system is supported at this time. 1494 1495 CONFIG_TPM_TIS_BASE_ADDRESS 1496 Base address where the generic TPM device is mapped 1497 to. Contemporary x86 systems usually map it at 1498 0xfed40000. 1499 1500 CONFIG_CMD_TPM 1501 Add tpm monitor functions. 1502 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1503 provides monitor access to authorized functions. 1504 1505 CONFIG_TPM 1506 Define this to enable the TPM support library which provides 1507 functional interfaces to some TPM commands. 1508 Requires support for a TPM device. 1509 1510 CONFIG_TPM_AUTH_SESSIONS 1511 Define this to enable authorized functions in the TPM library. 1512 Requires CONFIG_TPM and CONFIG_SHA1. 1513 1514- USB Support: 1515 At the moment only the UHCI host controller is 1516 supported (PIP405, MIP405, MPC5200); define 1517 CONFIG_USB_UHCI to enable it. 1518 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1519 and define CONFIG_USB_STORAGE to enable the USB 1520 storage devices. 1521 Note: 1522 Supported are USB Keyboards and USB Floppy drives 1523 (TEAC FD-05PUB). 1524 MPC5200 USB requires additional defines: 1525 CONFIG_USB_CLOCK 1526 for 528 MHz Clock: 0x0001bbbb 1527 CONFIG_PSC3_USB 1528 for USB on PSC3 1529 CONFIG_USB_CONFIG 1530 for differential drivers: 0x00001000 1531 for single ended drivers: 0x00005000 1532 for differential drivers on PSC3: 0x00000100 1533 for single ended drivers on PSC3: 0x00004100 1534 CONFIG_SYS_USB_EVENT_POLL 1535 May be defined to allow interrupt polling 1536 instead of using asynchronous interrupts 1537 1538 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1539 txfilltuning field in the EHCI controller on reset. 1540 1541 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1542 HW module registers. 1543 1544- USB Device: 1545 Define the below if you wish to use the USB console. 1546 Once firmware is rebuilt from a serial console issue the 1547 command "setenv stdin usbtty; setenv stdout usbtty" and 1548 attach your USB cable. The Unix command "dmesg" should print 1549 it has found a new device. The environment variable usbtty 1550 can be set to gserial or cdc_acm to enable your device to 1551 appear to a USB host as a Linux gserial device or a 1552 Common Device Class Abstract Control Model serial device. 1553 If you select usbtty = gserial you should be able to enumerate 1554 a Linux host by 1555 # modprobe usbserial vendor=0xVendorID product=0xProductID 1556 else if using cdc_acm, simply setting the environment 1557 variable usbtty to be cdc_acm should suffice. The following 1558 might be defined in YourBoardName.h 1559 1560 CONFIG_USB_DEVICE 1561 Define this to build a UDC device 1562 1563 CONFIG_USB_TTY 1564 Define this to have a tty type of device available to 1565 talk to the UDC device 1566 1567 CONFIG_USBD_HS 1568 Define this to enable the high speed support for usb 1569 device and usbtty. If this feature is enabled, a routine 1570 int is_usbd_high_speed(void) 1571 also needs to be defined by the driver to dynamically poll 1572 whether the enumeration has succeded at high speed or full 1573 speed. 1574 1575 CONFIG_SYS_CONSOLE_IS_IN_ENV 1576 Define this if you want stdin, stdout &/or stderr to 1577 be set to usbtty. 1578 1579 mpc8xx: 1580 CONFIG_SYS_USB_EXTC_CLK 0xBLAH 1581 Derive USB clock from external clock "blah" 1582 - CONFIG_SYS_USB_EXTC_CLK 0x02 1583 1584 CONFIG_SYS_USB_BRG_CLK 0xBLAH 1585 Derive USB clock from brgclk 1586 - CONFIG_SYS_USB_BRG_CLK 0x04 1587 1588 If you have a USB-IF assigned VendorID then you may wish to 1589 define your own vendor specific values either in BoardName.h 1590 or directly in usbd_vendor_info.h. If you don't define 1591 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1592 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1593 should pretend to be a Linux device to it's target host. 1594 1595 CONFIG_USBD_MANUFACTURER 1596 Define this string as the name of your company for 1597 - CONFIG_USBD_MANUFACTURER "my company" 1598 1599 CONFIG_USBD_PRODUCT_NAME 1600 Define this string as the name of your product 1601 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1602 1603 CONFIG_USBD_VENDORID 1604 Define this as your assigned Vendor ID from the USB 1605 Implementors Forum. This *must* be a genuine Vendor ID 1606 to avoid polluting the USB namespace. 1607 - CONFIG_USBD_VENDORID 0xFFFF 1608 1609 CONFIG_USBD_PRODUCTID 1610 Define this as the unique Product ID 1611 for your device 1612 - CONFIG_USBD_PRODUCTID 0xFFFF 1613 1614- ULPI Layer Support: 1615 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1616 the generic ULPI layer. The generic layer accesses the ULPI PHY 1617 via the platform viewport, so you need both the genric layer and 1618 the viewport enabled. Currently only Chipidea/ARC based 1619 viewport is supported. 1620 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1621 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1622 If your ULPI phy needs a different reference clock than the 1623 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1624 the appropriate value in Hz. 1625 1626- MMC Support: 1627 The MMC controller on the Intel PXA is supported. To 1628 enable this define CONFIG_MMC. The MMC can be 1629 accessed from the boot prompt by mapping the device 1630 to physical memory similar to flash. Command line is 1631 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1632 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1633 1634 CONFIG_SH_MMCIF 1635 Support for Renesas on-chip MMCIF controller 1636 1637 CONFIG_SH_MMCIF_ADDR 1638 Define the base address of MMCIF registers 1639 1640 CONFIG_SH_MMCIF_CLK 1641 Define the clock frequency for MMCIF 1642 1643 CONFIG_GENERIC_MMC 1644 Enable the generic MMC driver 1645 1646 CONFIG_SUPPORT_EMMC_BOOT 1647 Enable some additional features of the eMMC boot partitions. 1648 1649 CONFIG_SUPPORT_EMMC_RPMB 1650 Enable the commands for reading, writing and programming the 1651 key for the Replay Protection Memory Block partition in eMMC. 1652 1653- USB Device Firmware Update (DFU) class support: 1654 CONFIG_USB_FUNCTION_DFU 1655 This enables the USB portion of the DFU USB class 1656 1657 CONFIG_CMD_DFU 1658 This enables the command "dfu" which is used to have 1659 U-Boot create a DFU class device via USB. This command 1660 requires that the "dfu_alt_info" environment variable be 1661 set and define the alt settings to expose to the host. 1662 1663 CONFIG_DFU_MMC 1664 This enables support for exposing (e)MMC devices via DFU. 1665 1666 CONFIG_DFU_NAND 1667 This enables support for exposing NAND devices via DFU. 1668 1669 CONFIG_DFU_RAM 1670 This enables support for exposing RAM via DFU. 1671 Note: DFU spec refer to non-volatile memory usage, but 1672 allow usages beyond the scope of spec - here RAM usage, 1673 one that would help mostly the developer. 1674 1675 CONFIG_SYS_DFU_DATA_BUF_SIZE 1676 Dfu transfer uses a buffer before writing data to the 1677 raw storage device. Make the size (in bytes) of this buffer 1678 configurable. The size of this buffer is also configurable 1679 through the "dfu_bufsiz" environment variable. 1680 1681 CONFIG_SYS_DFU_MAX_FILE_SIZE 1682 When updating files rather than the raw storage device, 1683 we use a static buffer to copy the file into and then write 1684 the buffer once we've been given the whole file. Define 1685 this to the maximum filesize (in bytes) for the buffer. 1686 Default is 4 MiB if undefined. 1687 1688 DFU_DEFAULT_POLL_TIMEOUT 1689 Poll timeout [ms], is the timeout a device can send to the 1690 host. The host must wait for this timeout before sending 1691 a subsequent DFU_GET_STATUS request to the device. 1692 1693 DFU_MANIFEST_POLL_TIMEOUT 1694 Poll timeout [ms], which the device sends to the host when 1695 entering dfuMANIFEST state. Host waits this timeout, before 1696 sending again an USB request to the device. 1697 1698- USB Device Android Fastboot support: 1699 CONFIG_USB_FUNCTION_FASTBOOT 1700 This enables the USB part of the fastboot gadget 1701 1702 CONFIG_CMD_FASTBOOT 1703 This enables the command "fastboot" which enables the Android 1704 fastboot mode for the platform's USB device. Fastboot is a USB 1705 protocol for downloading images, flashing and device control 1706 used on Android devices. 1707 See doc/README.android-fastboot for more information. 1708 1709 CONFIG_ANDROID_BOOT_IMAGE 1710 This enables support for booting images which use the Android 1711 image format header. 1712 1713 CONFIG_FASTBOOT_BUF_ADDR 1714 The fastboot protocol requires a large memory buffer for 1715 downloads. Define this to the starting RAM address to use for 1716 downloaded images. 1717 1718 CONFIG_FASTBOOT_BUF_SIZE 1719 The fastboot protocol requires a large memory buffer for 1720 downloads. This buffer should be as large as possible for a 1721 platform. Define this to the size available RAM for fastboot. 1722 1723 CONFIG_FASTBOOT_FLASH 1724 The fastboot protocol includes a "flash" command for writing 1725 the downloaded image to a non-volatile storage device. Define 1726 this to enable the "fastboot flash" command. 1727 1728 CONFIG_FASTBOOT_FLASH_MMC_DEV 1729 The fastboot "flash" command requires additional information 1730 regarding the non-volatile storage device. Define this to 1731 the eMMC device that fastboot should use to store the image. 1732 1733 CONFIG_FASTBOOT_GPT_NAME 1734 The fastboot "flash" command supports writing the downloaded 1735 image to the Protective MBR and the Primary GUID Partition 1736 Table. (Additionally, this downloaded image is post-processed 1737 to generate and write the Backup GUID Partition Table.) 1738 This occurs when the specified "partition name" on the 1739 "fastboot flash" command line matches this value. 1740 Default is GPT_ENTRY_NAME (currently "gpt") if undefined. 1741 1742- Journaling Flash filesystem support: 1743 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE, 1744 CONFIG_JFFS2_NAND_DEV 1745 Define these for a default partition on a NAND device 1746 1747 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1748 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1749 Define these for a default partition on a NOR device 1750 1751 CONFIG_SYS_JFFS_CUSTOM_PART 1752 Define this to create an own partition. You have to provide a 1753 function struct part_info* jffs2_part_info(int part_num) 1754 1755 If you define only one JFFS2 partition you may also want to 1756 #define CONFIG_SYS_JFFS_SINGLE_PART 1 1757 to disable the command chpart. This is the default when you 1758 have not defined a custom partition 1759 1760- FAT(File Allocation Table) filesystem write function support: 1761 CONFIG_FAT_WRITE 1762 1763 Define this to enable support for saving memory data as a 1764 file in FAT formatted partition. 1765 1766 This will also enable the command "fatwrite" enabling the 1767 user to write files to FAT. 1768 1769CBFS (Coreboot Filesystem) support 1770 CONFIG_CMD_CBFS 1771 1772 Define this to enable support for reading from a Coreboot 1773 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls 1774 and cbfsload. 1775 1776- FAT(File Allocation Table) filesystem cluster size: 1777 CONFIG_FS_FAT_MAX_CLUSTSIZE 1778 1779 Define the max cluster size for fat operations else 1780 a default value of 65536 will be defined. 1781 1782- Keyboard Support: 1783 CONFIG_ISA_KEYBOARD 1784 1785 Define this to enable standard (PC-Style) keyboard 1786 support 1787 1788 CONFIG_I8042_KBD 1789 Standard PC keyboard driver with US (is default) and 1790 GERMAN key layout (switch via environment 'keymap=de') support. 1791 Export function i8042_kbd_init, i8042_tstc and i8042_getc 1792 for cfb_console. Supports cursor blinking. 1793 1794 CONFIG_CROS_EC_KEYB 1795 Enables a Chrome OS keyboard using the CROS_EC interface. 1796 This uses CROS_EC to communicate with a second microcontroller 1797 which provides key scans on request. 1798 1799- Video support: 1800 CONFIG_VIDEO 1801 1802 Define this to enable video support (for output to 1803 video). 1804 1805 CONFIG_VIDEO_CT69000 1806 1807 Enable Chips & Technologies 69000 Video chip 1808 1809 CONFIG_VIDEO_SMI_LYNXEM 1810 Enable Silicon Motion SMI 712/710/810 Video chip. The 1811 video output is selected via environment 'videoout' 1812 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is 1813 assumed. 1814 1815 For the CT69000 and SMI_LYNXEM drivers, videomode is 1816 selected via environment 'videomode'. Two different ways 1817 are possible: 1818 - "videomode=num" 'num' is a standard LiLo mode numbers. 1819 Following standard modes are supported (* is default): 1820 1821 Colors 640x480 800x600 1024x768 1152x864 1280x1024 1822 -------------+--------------------------------------------- 1823 8 bits | 0x301* 0x303 0x305 0x161 0x307 1824 15 bits | 0x310 0x313 0x316 0x162 0x319 1825 16 bits | 0x311 0x314 0x317 0x163 0x31A 1826 24 bits | 0x312 0x315 0x318 ? 0x31B 1827 -------------+--------------------------------------------- 1828 (i.e. setenv videomode 317; saveenv; reset;) 1829 1830 - "videomode=bootargs" all the video parameters are parsed 1831 from the bootargs. (See drivers/video/videomodes.c) 1832 1833 1834 CONFIG_VIDEO_SED13806 1835 Enable Epson SED13806 driver. This driver supports 8bpp 1836 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP 1837 or CONFIG_VIDEO_SED13806_16BPP 1838 1839 CONFIG_FSL_DIU_FB 1840 Enable the Freescale DIU video driver. Reference boards for 1841 SOCs that have a DIU should define this macro to enable DIU 1842 support, and should also define these other macros: 1843 1844 CONFIG_SYS_DIU_ADDR 1845 CONFIG_VIDEO 1846 CONFIG_CMD_BMP 1847 CONFIG_CFB_CONSOLE 1848 CONFIG_VIDEO_SW_CURSOR 1849 CONFIG_VGA_AS_SINGLE_DEVICE 1850 CONFIG_VIDEO_LOGO 1851 CONFIG_VIDEO_BMP_LOGO 1852 1853 The DIU driver will look for the 'video-mode' environment 1854 variable, and if defined, enable the DIU as a console during 1855 boot. See the documentation file README.video for a 1856 description of this variable. 1857 1858 1859- Keyboard Support: 1860 CONFIG_KEYBOARD 1861 1862 Define this to enable a custom keyboard support. 1863 This simply calls drv_keyboard_init() which must be 1864 defined in your board-specific files. 1865 The only board using this so far is RBC823. 1866 1867- LCD Support: CONFIG_LCD 1868 1869 Define this to enable LCD support (for output to LCD 1870 display); also select one of the supported displays 1871 by defining one of these: 1872 1873 CONFIG_ATMEL_LCD: 1874 1875 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1876 1877 CONFIG_NEC_NL6448AC33: 1878 1879 NEC NL6448AC33-18. Active, color, single scan. 1880 1881 CONFIG_NEC_NL6448BC20 1882 1883 NEC NL6448BC20-08. 6.5", 640x480. 1884 Active, color, single scan. 1885 1886 CONFIG_NEC_NL6448BC33_54 1887 1888 NEC NL6448BC33-54. 10.4", 640x480. 1889 Active, color, single scan. 1890 1891 CONFIG_SHARP_16x9 1892 1893 Sharp 320x240. Active, color, single scan. 1894 It isn't 16x9, and I am not sure what it is. 1895 1896 CONFIG_SHARP_LQ64D341 1897 1898 Sharp LQ64D341 display, 640x480. 1899 Active, color, single scan. 1900 1901 CONFIG_HLD1045 1902 1903 HLD1045 display, 640x480. 1904 Active, color, single scan. 1905 1906 CONFIG_OPTREX_BW 1907 1908 Optrex CBL50840-2 NF-FW 99 22 M5 1909 or 1910 Hitachi LMG6912RPFC-00T 1911 or 1912 Hitachi SP14Q002 1913 1914 320x240. Black & white. 1915 1916 Normally display is black on white background; define 1917 CONFIG_SYS_WHITE_ON_BLACK to get it inverted. 1918 1919 CONFIG_LCD_ALIGNMENT 1920 1921 Normally the LCD is page-aligned (typically 4KB). If this is 1922 defined then the LCD will be aligned to this value instead. 1923 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1924 here, since it is cheaper to change data cache settings on 1925 a per-section basis. 1926 1927 CONFIG_CONSOLE_SCROLL_LINES 1928 1929 When the console need to be scrolled, this is the number of 1930 lines to scroll by. It defaults to 1. Increasing this makes 1931 the console jump but can help speed up operation when scrolling 1932 is slow. 1933 1934 CONFIG_LCD_ROTATION 1935 1936 Sometimes, for example if the display is mounted in portrait 1937 mode or even if it's mounted landscape but rotated by 180degree, 1938 we need to rotate our content of the display relative to the 1939 framebuffer, so that user can read the messages which are 1940 printed out. 1941 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1942 initialized with a given rotation from "vl_rot" out of 1943 "vidinfo_t" which is provided by the board specific code. 1944 The value for vl_rot is coded as following (matching to 1945 fbcon=rotate:<n> linux-kernel commandline): 1946 0 = no rotation respectively 0 degree 1947 1 = 90 degree rotation 1948 2 = 180 degree rotation 1949 3 = 270 degree rotation 1950 1951 If CONFIG_LCD_ROTATION is not defined, the console will be 1952 initialized with 0degree rotation. 1953 1954 CONFIG_LCD_BMP_RLE8 1955 1956 Support drawing of RLE8-compressed bitmaps on the LCD. 1957 1958 CONFIG_I2C_EDID 1959 1960 Enables an 'i2c edid' command which can read EDID 1961 information over I2C from an attached LCD display. 1962 1963- Splash Screen Support: CONFIG_SPLASH_SCREEN 1964 1965 If this option is set, the environment is checked for 1966 a variable "splashimage". If found, the usual display 1967 of logo, copyright and system information on the LCD 1968 is suppressed and the BMP image at the address 1969 specified in "splashimage" is loaded instead. The 1970 console is redirected to the "nulldev", too. This 1971 allows for a "silent" boot where a splash screen is 1972 loaded very quickly after power-on. 1973 1974 CONFIG_SPLASHIMAGE_GUARD 1975 1976 If this option is set, then U-Boot will prevent the environment 1977 variable "splashimage" from being set to a problematic address 1978 (see README.displaying-bmps). 1979 This option is useful for targets where, due to alignment 1980 restrictions, an improperly aligned BMP image will cause a data 1981 abort. If you think you will not have problems with unaligned 1982 accesses (for example because your toolchain prevents them) 1983 there is no need to set this option. 1984 1985 CONFIG_SPLASH_SCREEN_ALIGN 1986 1987 If this option is set the splash image can be freely positioned 1988 on the screen. Environment variable "splashpos" specifies the 1989 position as "x,y". If a positive number is given it is used as 1990 number of pixel from left/top. If a negative number is given it 1991 is used as number of pixel from right/bottom. You can also 1992 specify 'm' for centering the image. 1993 1994 Example: 1995 setenv splashpos m,m 1996 => image at center of screen 1997 1998 setenv splashpos 30,20 1999 => image at x = 30 and y = 20 2000 2001 setenv splashpos -10,m 2002 => vertically centered image 2003 at x = dspWidth - bmpWidth - 9 2004 2005- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 2006 2007 If this option is set, additionally to standard BMP 2008 images, gzipped BMP images can be displayed via the 2009 splashscreen support or the bmp command. 2010 2011- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 2012 2013 If this option is set, 8-bit RLE compressed BMP images 2014 can be displayed via the splashscreen support or the 2015 bmp command. 2016 2017- Do compressing for memory range: 2018 CONFIG_CMD_ZIP 2019 2020 If this option is set, it would use zlib deflate method 2021 to compress the specified memory at its best effort. 2022 2023- Compression support: 2024 CONFIG_GZIP 2025 2026 Enabled by default to support gzip compressed images. 2027 2028 CONFIG_BZIP2 2029 2030 If this option is set, support for bzip2 compressed 2031 images is included. If not, only uncompressed and gzip 2032 compressed images are supported. 2033 2034 NOTE: the bzip2 algorithm requires a lot of RAM, so 2035 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 2036 be at least 4MB. 2037 2038 CONFIG_LZMA 2039 2040 If this option is set, support for lzma compressed 2041 images is included. 2042 2043 Note: The LZMA algorithm adds between 2 and 4KB of code and it 2044 requires an amount of dynamic memory that is given by the 2045 formula: 2046 2047 (1846 + 768 << (lc + lp)) * sizeof(uint16) 2048 2049 Where lc and lp stand for, respectively, Literal context bits 2050 and Literal pos bits. 2051 2052 This value is upper-bounded by 14MB in the worst case. Anyway, 2053 for a ~4MB large kernel image, we have lc=3 and lp=0 for a 2054 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is 2055 a very small buffer. 2056 2057 Use the lzmainfo tool to determinate the lc and lp values and 2058 then calculate the amount of needed dynamic memory (ensuring 2059 the appropriate CONFIG_SYS_MALLOC_LEN value). 2060 2061 CONFIG_LZO 2062 2063 If this option is set, support for LZO compressed images 2064 is included. 2065 2066- MII/PHY support: 2067 CONFIG_PHY_ADDR 2068 2069 The address of PHY on MII bus. 2070 2071 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 2072 2073 The clock frequency of the MII bus 2074 2075 CONFIG_PHY_GIGE 2076 2077 If this option is set, support for speed/duplex 2078 detection of gigabit PHY is included. 2079 2080 CONFIG_PHY_RESET_DELAY 2081 2082 Some PHY like Intel LXT971A need extra delay after 2083 reset before any MII register access is possible. 2084 For such PHY, set this option to the usec delay 2085 required. (minimum 300usec for LXT971A) 2086 2087 CONFIG_PHY_CMD_DELAY (ppc4xx) 2088 2089 Some PHY like Intel LXT971A need extra delay after 2090 command issued before MII status register can be read 2091 2092- IP address: 2093 CONFIG_IPADDR 2094 2095 Define a default value for the IP address to use for 2096 the default Ethernet interface, in case this is not 2097 determined through e.g. bootp. 2098 (Environment variable "ipaddr") 2099 2100- Server IP address: 2101 CONFIG_SERVERIP 2102 2103 Defines a default value for the IP address of a TFTP 2104 server to contact when using the "tftboot" command. 2105 (Environment variable "serverip") 2106 2107 CONFIG_KEEP_SERVERADDR 2108 2109 Keeps the server's MAC address, in the env 'serveraddr' 2110 for passing to bootargs (like Linux's netconsole option) 2111 2112- Gateway IP address: 2113 CONFIG_GATEWAYIP 2114 2115 Defines a default value for the IP address of the 2116 default router where packets to other networks are 2117 sent to. 2118 (Environment variable "gatewayip") 2119 2120- Subnet mask: 2121 CONFIG_NETMASK 2122 2123 Defines a default value for the subnet mask (or 2124 routing prefix) which is used to determine if an IP 2125 address belongs to the local subnet or needs to be 2126 forwarded through a router. 2127 (Environment variable "netmask") 2128 2129- Multicast TFTP Mode: 2130 CONFIG_MCAST_TFTP 2131 2132 Defines whether you want to support multicast TFTP as per 2133 rfc-2090; for example to work with atftp. Lets lots of targets 2134 tftp down the same boot image concurrently. Note: the Ethernet 2135 driver in use must provide a function: mcast() to join/leave a 2136 multicast group. 2137 2138- BOOTP Recovery Mode: 2139 CONFIG_BOOTP_RANDOM_DELAY 2140 2141 If you have many targets in a network that try to 2142 boot using BOOTP, you may want to avoid that all 2143 systems send out BOOTP requests at precisely the same 2144 moment (which would happen for instance at recovery 2145 from a power failure, when all systems will try to 2146 boot, thus flooding the BOOTP server. Defining 2147 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 2148 inserted before sending out BOOTP requests. The 2149 following delays are inserted then: 2150 2151 1st BOOTP request: delay 0 ... 1 sec 2152 2nd BOOTP request: delay 0 ... 2 sec 2153 3rd BOOTP request: delay 0 ... 4 sec 2154 4th and following 2155 BOOTP requests: delay 0 ... 8 sec 2156 2157 CONFIG_BOOTP_ID_CACHE_SIZE 2158 2159 BOOTP packets are uniquely identified using a 32-bit ID. The 2160 server will copy the ID from client requests to responses and 2161 U-Boot will use this to determine if it is the destination of 2162 an incoming response. Some servers will check that addresses 2163 aren't in use before handing them out (usually using an ARP 2164 ping) and therefore take up to a few hundred milliseconds to 2165 respond. Network congestion may also influence the time it 2166 takes for a response to make it back to the client. If that 2167 time is too long, U-Boot will retransmit requests. In order 2168 to allow earlier responses to still be accepted after these 2169 retransmissions, U-Boot's BOOTP client keeps a small cache of 2170 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 2171 cache. The default is to keep IDs for up to four outstanding 2172 requests. Increasing this will allow U-Boot to accept offers 2173 from a BOOTP client in networks with unusually high latency. 2174 2175- DHCP Advanced Options: 2176 You can fine tune the DHCP functionality by defining 2177 CONFIG_BOOTP_* symbols: 2178 2179 CONFIG_BOOTP_SUBNETMASK 2180 CONFIG_BOOTP_GATEWAY 2181 CONFIG_BOOTP_HOSTNAME 2182 CONFIG_BOOTP_NISDOMAIN 2183 CONFIG_BOOTP_BOOTPATH 2184 CONFIG_BOOTP_BOOTFILESIZE 2185 CONFIG_BOOTP_DNS 2186 CONFIG_BOOTP_DNS2 2187 CONFIG_BOOTP_SEND_HOSTNAME 2188 CONFIG_BOOTP_NTPSERVER 2189 CONFIG_BOOTP_TIMEOFFSET 2190 CONFIG_BOOTP_VENDOREX 2191 CONFIG_BOOTP_MAY_FAIL 2192 2193 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 2194 environment variable, not the BOOTP server. 2195 2196 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 2197 after the configured retry count, the call will fail 2198 instead of starting over. This can be used to fail over 2199 to Link-local IP address configuration if the DHCP server 2200 is not available. 2201 2202 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 2203 serverip from a DHCP server, it is possible that more 2204 than one DNS serverip is offered to the client. 2205 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 2206 serverip will be stored in the additional environment 2207 variable "dnsip2". The first DNS serverip is always 2208 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 2209 is defined. 2210 2211 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 2212 to do a dynamic update of a DNS server. To do this, they 2213 need the hostname of the DHCP requester. 2214 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 2215 of the "hostname" environment variable is passed as 2216 option 12 to the DHCP server. 2217 2218 CONFIG_BOOTP_DHCP_REQUEST_DELAY 2219 2220 A 32bit value in microseconds for a delay between 2221 receiving a "DHCP Offer" and sending the "DHCP Request". 2222 This fixes a problem with certain DHCP servers that don't 2223 respond 100% of the time to a "DHCP request". E.g. On an 2224 AT91RM9200 processor running at 180MHz, this delay needed 2225 to be *at least* 15,000 usec before a Windows Server 2003 2226 DHCP server would reply 100% of the time. I recommend at 2227 least 50,000 usec to be safe. The alternative is to hope 2228 that one of the retries will be successful but note that 2229 the DHCP timeout and retry process takes a longer than 2230 this delay. 2231 2232 - Link-local IP address negotiation: 2233 Negotiate with other link-local clients on the local network 2234 for an address that doesn't require explicit configuration. 2235 This is especially useful if a DHCP server cannot be guaranteed 2236 to exist in all environments that the device must operate. 2237 2238 See doc/README.link-local for more information. 2239 2240 - CDP Options: 2241 CONFIG_CDP_DEVICE_ID 2242 2243 The device id used in CDP trigger frames. 2244 2245 CONFIG_CDP_DEVICE_ID_PREFIX 2246 2247 A two character string which is prefixed to the MAC address 2248 of the device. 2249 2250 CONFIG_CDP_PORT_ID 2251 2252 A printf format string which contains the ascii name of 2253 the port. Normally is set to "eth%d" which sets 2254 eth0 for the first Ethernet, eth1 for the second etc. 2255 2256 CONFIG_CDP_CAPABILITIES 2257 2258 A 32bit integer which indicates the device capabilities; 2259 0x00000010 for a normal host which does not forwards. 2260 2261 CONFIG_CDP_VERSION 2262 2263 An ascii string containing the version of the software. 2264 2265 CONFIG_CDP_PLATFORM 2266 2267 An ascii string containing the name of the platform. 2268 2269 CONFIG_CDP_TRIGGER 2270 2271 A 32bit integer sent on the trigger. 2272 2273 CONFIG_CDP_POWER_CONSUMPTION 2274 2275 A 16bit integer containing the power consumption of the 2276 device in .1 of milliwatts. 2277 2278 CONFIG_CDP_APPLIANCE_VLAN_TYPE 2279 2280 A byte containing the id of the VLAN. 2281 2282- Status LED: CONFIG_STATUS_LED 2283 2284 Several configurations allow to display the current 2285 status using a LED. For instance, the LED will blink 2286 fast while running U-Boot code, stop blinking as 2287 soon as a reply to a BOOTP request was received, and 2288 start blinking slow once the Linux kernel is running 2289 (supported by a status LED driver in the Linux 2290 kernel). Defining CONFIG_STATUS_LED enables this 2291 feature in U-Boot. 2292 2293 Additional options: 2294 2295 CONFIG_GPIO_LED 2296 The status LED can be connected to a GPIO pin. 2297 In such cases, the gpio_led driver can be used as a 2298 status LED backend implementation. Define CONFIG_GPIO_LED 2299 to include the gpio_led driver in the U-Boot binary. 2300 2301 CONFIG_GPIO_LED_INVERTED_TABLE 2302 Some GPIO connected LEDs may have inverted polarity in which 2303 case the GPIO high value corresponds to LED off state and 2304 GPIO low value corresponds to LED on state. 2305 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 2306 with a list of GPIO LEDs that have inverted polarity. 2307 2308- CAN Support: CONFIG_CAN_DRIVER 2309 2310 Defining CONFIG_CAN_DRIVER enables CAN driver support 2311 on those systems that support this (optional) 2312 feature, like the TQM8xxL modules. 2313 2314- I2C Support: CONFIG_SYS_I2C 2315 2316 This enable the NEW i2c subsystem, and will allow you to use 2317 i2c commands at the u-boot command line (as long as you set 2318 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 2319 based realtime clock chips or other i2c devices. See 2320 common/cmd_i2c.c for a description of the command line 2321 interface. 2322 2323 ported i2c driver to the new framework: 2324 - drivers/i2c/soft_i2c.c: 2325 - activate first bus with CONFIG_SYS_I2C_SOFT define 2326 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 2327 for defining speed and slave address 2328 - activate second bus with I2C_SOFT_DECLARATIONS2 define 2329 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 2330 for defining speed and slave address 2331 - activate third bus with I2C_SOFT_DECLARATIONS3 define 2332 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 2333 for defining speed and slave address 2334 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 2335 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 2336 for defining speed and slave address 2337 2338 - drivers/i2c/fsl_i2c.c: 2339 - activate i2c driver with CONFIG_SYS_I2C_FSL 2340 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 2341 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 2342 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 2343 bus. 2344 - If your board supports a second fsl i2c bus, define 2345 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 2346 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 2347 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 2348 second bus. 2349 2350 - drivers/i2c/tegra_i2c.c: 2351 - activate this driver with CONFIG_SYS_I2C_TEGRA 2352 - This driver adds 4 i2c buses with a fix speed from 2353 100000 and the slave addr 0! 2354 2355 - drivers/i2c/ppc4xx_i2c.c 2356 - activate this driver with CONFIG_SYS_I2C_PPC4XX 2357 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 2358 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 2359 2360 - drivers/i2c/i2c_mxc.c 2361 - activate this driver with CONFIG_SYS_I2C_MXC 2362 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 2363 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 2364 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 2365 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 2366 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 2367 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 2368 If those defines are not set, default value is 100000 2369 for speed, and 0 for slave. 2370 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 2371 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 2372 2373 - drivers/i2c/rcar_i2c.c: 2374 - activate this driver with CONFIG_SYS_I2C_RCAR 2375 - This driver adds 4 i2c buses 2376 2377 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 2378 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 2379 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 2380 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 2381 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 2382 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 2383 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 2384 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 2385 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 2386 2387 - drivers/i2c/sh_i2c.c: 2388 - activate this driver with CONFIG_SYS_I2C_SH 2389 - This driver adds from 2 to 5 i2c buses 2390 2391 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 2392 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 2393 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 2394 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 2395 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 2396 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 2397 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 2398 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 2399 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 2400 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 2401 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5 2402 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5 2403 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 2404 2405 - drivers/i2c/omap24xx_i2c.c 2406 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 2407 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 2408 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 2409 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 2410 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 2411 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 2412 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 2413 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2414 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2415 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2416 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2417 2418 - drivers/i2c/zynq_i2c.c 2419 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2420 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2421 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2422 2423 - drivers/i2c/s3c24x0_i2c.c: 2424 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2425 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2426 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2427 with a fix speed from 100000 and the slave addr 0! 2428 2429 - drivers/i2c/ihs_i2c.c 2430 - activate this driver with CONFIG_SYS_I2C_IHS 2431 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2432 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2433 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2434 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2435 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2436 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2437 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2438 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2439 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2440 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2441 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2442 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2443 2444 additional defines: 2445 2446 CONFIG_SYS_NUM_I2C_BUSES 2447 Hold the number of i2c buses you want to use. If you 2448 don't use/have i2c muxes on your i2c bus, this 2449 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can 2450 omit this define. 2451 2452 CONFIG_SYS_I2C_DIRECT_BUS 2453 define this, if you don't use i2c muxes on your hardware. 2454 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2455 omit this define. 2456 2457 CONFIG_SYS_I2C_MAX_HOPS 2458 define how many muxes are maximal consecutively connected 2459 on one i2c bus. If you not use i2c muxes, omit this 2460 define. 2461 2462 CONFIG_SYS_I2C_BUSES 2463 hold a list of buses you want to use, only used if 2464 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2465 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2466 CONFIG_SYS_NUM_I2C_BUSES = 9: 2467 2468 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2469 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2470 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2471 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2472 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2473 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2474 {1, {I2C_NULL_HOP}}, \ 2475 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2476 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2477 } 2478 2479 which defines 2480 bus 0 on adapter 0 without a mux 2481 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2482 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2483 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2484 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2485 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2486 bus 6 on adapter 1 without a mux 2487 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2488 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2489 2490 If you do not have i2c muxes on your board, omit this define. 2491 2492- Legacy I2C Support: CONFIG_HARD_I2C 2493 2494 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which 2495 provides the following compelling advantages: 2496 2497 - more than one i2c adapter is usable 2498 - approved multibus support 2499 - better i2c mux support 2500 2501 ** Please consider updating your I2C driver now. ** 2502 2503 These enable legacy I2C serial bus commands. Defining 2504 CONFIG_HARD_I2C will include the appropriate I2C driver 2505 for the selected CPU. 2506 2507 This will allow you to use i2c commands at the u-boot 2508 command line (as long as you set CONFIG_CMD_I2C in 2509 CONFIG_COMMANDS) and communicate with i2c based realtime 2510 clock chips. See common/cmd_i2c.c for a description of the 2511 command line interface. 2512 2513 CONFIG_HARD_I2C selects a hardware I2C controller. 2514 2515 There are several other quantities that must also be 2516 defined when you define CONFIG_HARD_I2C. 2517 2518 In both cases you will need to define CONFIG_SYS_I2C_SPEED 2519 to be the frequency (in Hz) at which you wish your i2c bus 2520 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie 2521 the CPU's i2c node address). 2522 2523 Now, the u-boot i2c code for the mpc8xx 2524 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node 2525 and so its address should therefore be cleared to 0 (See, 2526 eg, MPC823e User's Manual p.16-473). So, set 2527 CONFIG_SYS_I2C_SLAVE to 0. 2528 2529 CONFIG_SYS_I2C_INIT_MPC5XXX 2530 2531 When a board is reset during an i2c bus transfer 2532 chips might think that the current transfer is still 2533 in progress. Reset the slave devices by sending start 2534 commands until the slave device responds. 2535 2536 That's all that's required for CONFIG_HARD_I2C. 2537 2538 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2539 then the following macros need to be defined (examples are 2540 from include/configs/lwmon.h): 2541 2542 I2C_INIT 2543 2544 (Optional). Any commands necessary to enable the I2C 2545 controller or configure ports. 2546 2547 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2548 2549 I2C_PORT 2550 2551 (Only for MPC8260 CPU). The I/O port to use (the code 2552 assumes both bits are on the same port). Valid values 2553 are 0..3 for ports A..D. 2554 2555 I2C_ACTIVE 2556 2557 The code necessary to make the I2C data line active 2558 (driven). If the data line is open collector, this 2559 define can be null. 2560 2561 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2562 2563 I2C_TRISTATE 2564 2565 The code necessary to make the I2C data line tri-stated 2566 (inactive). If the data line is open collector, this 2567 define can be null. 2568 2569 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2570 2571 I2C_READ 2572 2573 Code that returns true if the I2C data line is high, 2574 false if it is low. 2575 2576 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2577 2578 I2C_SDA(bit) 2579 2580 If <bit> is true, sets the I2C data line high. If it 2581 is false, it clears it (low). 2582 2583 eg: #define I2C_SDA(bit) \ 2584 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2585 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2586 2587 I2C_SCL(bit) 2588 2589 If <bit> is true, sets the I2C clock line high. If it 2590 is false, it clears it (low). 2591 2592 eg: #define I2C_SCL(bit) \ 2593 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2594 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2595 2596 I2C_DELAY 2597 2598 This delay is invoked four times per clock cycle so this 2599 controls the rate of data transfer. The data rate thus 2600 is 1 / (I2C_DELAY * 4). Often defined to be something 2601 like: 2602 2603 #define I2C_DELAY udelay(2) 2604 2605 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2606 2607 If your arch supports the generic GPIO framework (asm/gpio.h), 2608 then you may alternatively define the two GPIOs that are to be 2609 used as SCL / SDA. Any of the previous I2C_xxx macros will 2610 have GPIO-based defaults assigned to them as appropriate. 2611 2612 You should define these to the GPIO value as given directly to 2613 the generic GPIO functions. 2614 2615 CONFIG_SYS_I2C_INIT_BOARD 2616 2617 When a board is reset during an i2c bus transfer 2618 chips might think that the current transfer is still 2619 in progress. On some boards it is possible to access 2620 the i2c SCLK line directly, either by using the 2621 processor pin as a GPIO or by having a second pin 2622 connected to the bus. If this option is defined a 2623 custom i2c_init_board() routine in boards/xxx/board.c 2624 is run early in the boot sequence. 2625 2626 CONFIG_SYS_I2C_BOARD_LATE_INIT 2627 2628 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is 2629 defined a custom i2c_board_late_init() routine in 2630 boards/xxx/board.c is run AFTER the operations in i2c_init() 2631 is completed. This callpoint can be used to unreset i2c bus 2632 using CPU i2c controller register accesses for CPUs whose i2c 2633 controller provide such a method. It is called at the end of 2634 i2c_init() to allow i2c_init operations to setup the i2c bus 2635 controller on the CPU (e.g. setting bus speed & slave address). 2636 2637 CONFIG_I2CFAST (PPC405GP|PPC405EP only) 2638 2639 This option enables configuration of bi_iic_fast[] flags 2640 in u-boot bd_info structure based on u-boot environment 2641 variable "i2cfast". (see also i2cfast) 2642 2643 CONFIG_I2C_MULTI_BUS 2644 2645 This option allows the use of multiple I2C buses, each of which 2646 must have a controller. At any point in time, only one bus is 2647 active. To switch to a different bus, use the 'i2c dev' command. 2648 Note that bus numbering is zero-based. 2649 2650 CONFIG_SYS_I2C_NOPROBES 2651 2652 This option specifies a list of I2C devices that will be skipped 2653 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2654 is set, specify a list of bus-device pairs. Otherwise, specify 2655 a 1D array of device addresses 2656 2657 e.g. 2658 #undef CONFIG_I2C_MULTI_BUS 2659 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2660 2661 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2662 2663 #define CONFIG_I2C_MULTI_BUS 2664 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2665 2666 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2667 2668 CONFIG_SYS_SPD_BUS_NUM 2669 2670 If defined, then this indicates the I2C bus number for DDR SPD. 2671 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2672 2673 CONFIG_SYS_RTC_BUS_NUM 2674 2675 If defined, then this indicates the I2C bus number for the RTC. 2676 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2677 2678 CONFIG_SYS_DTT_BUS_NUM 2679 2680 If defined, then this indicates the I2C bus number for the DTT. 2681 If not defined, then U-Boot assumes that DTT is on I2C bus 0. 2682 2683 CONFIG_SYS_I2C_DTT_ADDR: 2684 2685 If defined, specifies the I2C address of the DTT device. 2686 If not defined, then U-Boot uses predefined value for 2687 specified DTT device. 2688 2689 CONFIG_SOFT_I2C_READ_REPEATED_START 2690 2691 defining this will force the i2c_read() function in 2692 the soft_i2c driver to perform an I2C repeated start 2693 between writing the address pointer and reading the 2694 data. If this define is omitted the default behaviour 2695 of doing a stop-start sequence will be used. Most I2C 2696 devices can use either method, but some require one or 2697 the other. 2698 2699- SPI Support: CONFIG_SPI 2700 2701 Enables SPI driver (so far only tested with 2702 SPI EEPROM, also an instance works with Crystal A/D and 2703 D/As on the SACSng board) 2704 2705 CONFIG_SH_SPI 2706 2707 Enables the driver for SPI controller on SuperH. Currently 2708 only SH7757 is supported. 2709 2710 CONFIG_SPI_X 2711 2712 Enables extended (16-bit) SPI EEPROM addressing. 2713 (symmetrical to CONFIG_I2C_X) 2714 2715 CONFIG_SOFT_SPI 2716 2717 Enables a software (bit-bang) SPI driver rather than 2718 using hardware support. This is a general purpose 2719 driver that only requires three general I/O port pins 2720 (two outputs, one input) to function. If this is 2721 defined, the board configuration must define several 2722 SPI configuration items (port pins to use, etc). For 2723 an example, see include/configs/sacsng.h. 2724 2725 CONFIG_HARD_SPI 2726 2727 Enables a hardware SPI driver for general-purpose reads 2728 and writes. As with CONFIG_SOFT_SPI, the board configuration 2729 must define a list of chip-select function pointers. 2730 Currently supported on some MPC8xxx processors. For an 2731 example, see include/configs/mpc8349emds.h. 2732 2733 CONFIG_MXC_SPI 2734 2735 Enables the driver for the SPI controllers on i.MX and MXC 2736 SoCs. Currently i.MX31/35/51 are supported. 2737 2738 CONFIG_SYS_SPI_MXC_WAIT 2739 Timeout for waiting until spi transfer completed. 2740 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2741 2742- FPGA Support: CONFIG_FPGA 2743 2744 Enables FPGA subsystem. 2745 2746 CONFIG_FPGA_<vendor> 2747 2748 Enables support for specific chip vendors. 2749 (ALTERA, XILINX) 2750 2751 CONFIG_FPGA_<family> 2752 2753 Enables support for FPGA family. 2754 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2755 2756 CONFIG_FPGA_COUNT 2757 2758 Specify the number of FPGA devices to support. 2759 2760 CONFIG_CMD_FPGA_LOADMK 2761 2762 Enable support for fpga loadmk command 2763 2764 CONFIG_CMD_FPGA_LOADP 2765 2766 Enable support for fpga loadp command - load partial bitstream 2767 2768 CONFIG_CMD_FPGA_LOADBP 2769 2770 Enable support for fpga loadbp command - load partial bitstream 2771 (Xilinx only) 2772 2773 CONFIG_SYS_FPGA_PROG_FEEDBACK 2774 2775 Enable printing of hash marks during FPGA configuration. 2776 2777 CONFIG_SYS_FPGA_CHECK_BUSY 2778 2779 Enable checks on FPGA configuration interface busy 2780 status by the configuration function. This option 2781 will require a board or device specific function to 2782 be written. 2783 2784 CONFIG_FPGA_DELAY 2785 2786 If defined, a function that provides delays in the FPGA 2787 configuration driver. 2788 2789 CONFIG_SYS_FPGA_CHECK_CTRLC 2790 Allow Control-C to interrupt FPGA configuration 2791 2792 CONFIG_SYS_FPGA_CHECK_ERROR 2793 2794 Check for configuration errors during FPGA bitfile 2795 loading. For example, abort during Virtex II 2796 configuration if the INIT_B line goes low (which 2797 indicated a CRC error). 2798 2799 CONFIG_SYS_FPGA_WAIT_INIT 2800 2801 Maximum time to wait for the INIT_B line to de-assert 2802 after PROB_B has been de-asserted during a Virtex II 2803 FPGA configuration sequence. The default time is 500 2804 ms. 2805 2806 CONFIG_SYS_FPGA_WAIT_BUSY 2807 2808 Maximum time to wait for BUSY to de-assert during 2809 Virtex II FPGA configuration. The default is 5 ms. 2810 2811 CONFIG_SYS_FPGA_WAIT_CONFIG 2812 2813 Time to wait after FPGA configuration. The default is 2814 200 ms. 2815 2816- Configuration Management: 2817 CONFIG_BUILD_TARGET 2818 2819 Some SoCs need special image types (e.g. U-Boot binary 2820 with a special header) as build targets. By defining 2821 CONFIG_BUILD_TARGET in the SoC / board header, this 2822 special image will be automatically built upon calling 2823 make / MAKEALL. 2824 2825 CONFIG_IDENT_STRING 2826 2827 If defined, this string will be added to the U-Boot 2828 version information (U_BOOT_VERSION) 2829 2830- Vendor Parameter Protection: 2831 2832 U-Boot considers the values of the environment 2833 variables "serial#" (Board Serial Number) and 2834 "ethaddr" (Ethernet Address) to be parameters that 2835 are set once by the board vendor / manufacturer, and 2836 protects these variables from casual modification by 2837 the user. Once set, these variables are read-only, 2838 and write or delete attempts are rejected. You can 2839 change this behaviour: 2840 2841 If CONFIG_ENV_OVERWRITE is #defined in your config 2842 file, the write protection for vendor parameters is 2843 completely disabled. Anybody can change or delete 2844 these parameters. 2845 2846 Alternatively, if you define _both_ an ethaddr in the 2847 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2848 Ethernet address is installed in the environment, 2849 which can be changed exactly ONCE by the user. [The 2850 serial# is unaffected by this, i. e. it remains 2851 read-only.] 2852 2853 The same can be accomplished in a more flexible way 2854 for any variable by configuring the type of access 2855 to allow for those variables in the ".flags" variable 2856 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2857 2858- Protected RAM: 2859 CONFIG_PRAM 2860 2861 Define this variable to enable the reservation of 2862 "protected RAM", i. e. RAM which is not overwritten 2863 by U-Boot. Define CONFIG_PRAM to hold the number of 2864 kB you want to reserve for pRAM. You can overwrite 2865 this default value by defining an environment 2866 variable "pram" to the number of kB you want to 2867 reserve. Note that the board info structure will 2868 still show the full amount of RAM. If pRAM is 2869 reserved, a new environment variable "mem" will 2870 automatically be defined to hold the amount of 2871 remaining RAM in a form that can be passed as boot 2872 argument to Linux, for instance like that: 2873 2874 setenv bootargs ... mem=\${mem} 2875 saveenv 2876 2877 This way you can tell Linux not to use this memory, 2878 either, which results in a memory region that will 2879 not be affected by reboots. 2880 2881 *WARNING* If your board configuration uses automatic 2882 detection of the RAM size, you must make sure that 2883 this memory test is non-destructive. So far, the 2884 following board configurations are known to be 2885 "pRAM-clean": 2886 2887 IVMS8, IVML24, SPD8xx, TQM8xxL, 2888 HERMES, IP860, RPXlite, LWMON, 2889 FLAGADM, TQM8260 2890 2891- Access to physical memory region (> 4GB) 2892 Some basic support is provided for operations on memory not 2893 normally accessible to U-Boot - e.g. some architectures 2894 support access to more than 4GB of memory on 32-bit 2895 machines using physical address extension or similar. 2896 Define CONFIG_PHYSMEM to access this basic support, which 2897 currently only supports clearing the memory. 2898 2899- Error Recovery: 2900 CONFIG_PANIC_HANG 2901 2902 Define this variable to stop the system in case of a 2903 fatal error, so that you have to reset it manually. 2904 This is probably NOT a good idea for an embedded 2905 system where you want the system to reboot 2906 automatically as fast as possible, but it may be 2907 useful during development since you can try to debug 2908 the conditions that lead to the situation. 2909 2910 CONFIG_NET_RETRY_COUNT 2911 2912 This variable defines the number of retries for 2913 network operations like ARP, RARP, TFTP, or BOOTP 2914 before giving up the operation. If not defined, a 2915 default value of 5 is used. 2916 2917 CONFIG_ARP_TIMEOUT 2918 2919 Timeout waiting for an ARP reply in milliseconds. 2920 2921 CONFIG_NFS_TIMEOUT 2922 2923 Timeout in milliseconds used in NFS protocol. 2924 If you encounter "ERROR: Cannot umount" in nfs command, 2925 try longer timeout such as 2926 #define CONFIG_NFS_TIMEOUT 10000UL 2927 2928- Command Interpreter: 2929 CONFIG_AUTO_COMPLETE 2930 2931 Enable auto completion of commands using TAB. 2932 2933 CONFIG_SYS_PROMPT_HUSH_PS2 2934 2935 This defines the secondary prompt string, which is 2936 printed when the command interpreter needs more input 2937 to complete a command. Usually "> ". 2938 2939 Note: 2940 2941 In the current implementation, the local variables 2942 space and global environment variables space are 2943 separated. Local variables are those you define by 2944 simply typing `name=value'. To access a local 2945 variable later on, you have write `$name' or 2946 `${name}'; to execute the contents of a variable 2947 directly type `$name' at the command prompt. 2948 2949 Global environment variables are those you use 2950 setenv/printenv to work with. To run a command stored 2951 in such a variable, you need to use the run command, 2952 and you must not use the '$' sign to access them. 2953 2954 To store commands and special characters in a 2955 variable, please use double quotation marks 2956 surrounding the whole text of the variable, instead 2957 of the backslashes before semicolons and special 2958 symbols. 2959 2960- Command Line Editing and History: 2961 CONFIG_CMDLINE_EDITING 2962 2963 Enable editing and History functions for interactive 2964 command line input operations 2965 2966- Default Environment: 2967 CONFIG_EXTRA_ENV_SETTINGS 2968 2969 Define this to contain any number of null terminated 2970 strings (variable = value pairs) that will be part of 2971 the default environment compiled into the boot image. 2972 2973 For example, place something like this in your 2974 board's config file: 2975 2976 #define CONFIG_EXTRA_ENV_SETTINGS \ 2977 "myvar1=value1\0" \ 2978 "myvar2=value2\0" 2979 2980 Warning: This method is based on knowledge about the 2981 internal format how the environment is stored by the 2982 U-Boot code. This is NOT an official, exported 2983 interface! Although it is unlikely that this format 2984 will change soon, there is no guarantee either. 2985 You better know what you are doing here. 2986 2987 Note: overly (ab)use of the default environment is 2988 discouraged. Make sure to check other ways to preset 2989 the environment like the "source" command or the 2990 boot command first. 2991 2992 CONFIG_ENV_VARS_UBOOT_CONFIG 2993 2994 Define this in order to add variables describing the 2995 U-Boot build configuration to the default environment. 2996 These will be named arch, cpu, board, vendor, and soc. 2997 2998 Enabling this option will cause the following to be defined: 2999 3000 - CONFIG_SYS_ARCH 3001 - CONFIG_SYS_CPU 3002 - CONFIG_SYS_BOARD 3003 - CONFIG_SYS_VENDOR 3004 - CONFIG_SYS_SOC 3005 3006 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 3007 3008 Define this in order to add variables describing certain 3009 run-time determined information about the hardware to the 3010 environment. These will be named board_name, board_rev. 3011 3012 CONFIG_DELAY_ENVIRONMENT 3013 3014 Normally the environment is loaded when the board is 3015 initialised so that it is available to U-Boot. This inhibits 3016 that so that the environment is not available until 3017 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 3018 this is instead controlled by the value of 3019 /config/load-environment. 3020 3021- Parallel Flash support: 3022 CONFIG_SYS_NO_FLASH 3023 3024 Traditionally U-boot was run on systems with parallel NOR 3025 flash. This option is used to disable support for parallel NOR 3026 flash. This option should be defined if the board does not have 3027 parallel flash. 3028 3029 If this option is not defined one of the generic flash drivers 3030 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be 3031 selected or the board must provide an implementation of the 3032 flash API (see include/flash.h). 3033 3034- DataFlash Support: 3035 CONFIG_HAS_DATAFLASH 3036 3037 Defining this option enables DataFlash features and 3038 allows to read/write in Dataflash via the standard 3039 commands cp, md... 3040 3041- Serial Flash support 3042 CONFIG_CMD_SF 3043 3044 Defining this option enables SPI flash commands 3045 'sf probe/read/write/erase/update'. 3046 3047 Usage requires an initial 'probe' to define the serial 3048 flash parameters, followed by read/write/erase/update 3049 commands. 3050 3051 The following defaults may be provided by the platform 3052 to handle the common case when only a single serial 3053 flash is present on the system. 3054 3055 CONFIG_SF_DEFAULT_BUS Bus identifier 3056 CONFIG_SF_DEFAULT_CS Chip-select 3057 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 3058 CONFIG_SF_DEFAULT_SPEED in Hz 3059 3060 CONFIG_CMD_SF_TEST 3061 3062 Define this option to include a destructive SPI flash 3063 test ('sf test'). 3064 3065 CONFIG_SF_DUAL_FLASH Dual flash memories 3066 3067 Define this option to use dual flash support where two flash 3068 memories can be connected with a given cs line. 3069 Currently Xilinx Zynq qspi supports these type of connections. 3070 3071- SystemACE Support: 3072 CONFIG_SYSTEMACE 3073 3074 Adding this option adds support for Xilinx SystemACE 3075 chips attached via some sort of local bus. The address 3076 of the chip must also be defined in the 3077 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 3078 3079 #define CONFIG_SYSTEMACE 3080 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 3081 3082 When SystemACE support is added, the "ace" device type 3083 becomes available to the fat commands, i.e. fatls. 3084 3085- TFTP Fixed UDP Port: 3086 CONFIG_TFTP_PORT 3087 3088 If this is defined, the environment variable tftpsrcp 3089 is used to supply the TFTP UDP source port value. 3090 If tftpsrcp isn't defined, the normal pseudo-random port 3091 number generator is used. 3092 3093 Also, the environment variable tftpdstp is used to supply 3094 the TFTP UDP destination port value. If tftpdstp isn't 3095 defined, the normal port 69 is used. 3096 3097 The purpose for tftpsrcp is to allow a TFTP server to 3098 blindly start the TFTP transfer using the pre-configured 3099 target IP address and UDP port. This has the effect of 3100 "punching through" the (Windows XP) firewall, allowing 3101 the remainder of the TFTP transfer to proceed normally. 3102 A better solution is to properly configure the firewall, 3103 but sometimes that is not allowed. 3104 3105- Hashing support: 3106 CONFIG_CMD_HASH 3107 3108 This enables a generic 'hash' command which can produce 3109 hashes / digests from a few algorithms (e.g. SHA1, SHA256). 3110 3111 CONFIG_HASH_VERIFY 3112 3113 Enable the hash verify command (hash -v). This adds to code 3114 size a little. 3115 3116 CONFIG_SHA1 - This option enables support of hashing using SHA1 3117 algorithm. The hash is calculated in software. 3118 CONFIG_SHA256 - This option enables support of hashing using 3119 SHA256 algorithm. The hash is calculated in software. 3120 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration 3121 for SHA1/SHA256 hashing. 3122 This affects the 'hash' command and also the 3123 hash_lookup_algo() function. 3124 CONFIG_SHA_PROG_HW_ACCEL - This option enables 3125 hardware-acceleration for SHA1/SHA256 progressive hashing. 3126 Data can be streamed in a block at a time and the hashing 3127 is performed in hardware. 3128 3129 Note: There is also a sha1sum command, which should perhaps 3130 be deprecated in favour of 'hash sha1'. 3131 3132- Freescale i.MX specific commands: 3133 CONFIG_CMD_HDMIDETECT 3134 This enables 'hdmidet' command which returns true if an 3135 HDMI monitor is detected. This command is i.MX 6 specific. 3136 3137 CONFIG_CMD_BMODE 3138 This enables the 'bmode' (bootmode) command for forcing 3139 a boot from specific media. 3140 3141 This is useful for forcing the ROM's usb downloader to 3142 activate upon a watchdog reset which is nice when iterating 3143 on U-Boot. Using the reset button or running bmode normal 3144 will set it back to normal. This command currently 3145 supports i.MX53 and i.MX6. 3146 3147- Signing support: 3148 CONFIG_RSA 3149 3150 This enables the RSA algorithm used for FIT image verification 3151 in U-Boot. See doc/uImage.FIT/signature.txt for more information. 3152 3153 The Modular Exponentiation algorithm in RSA is implemented using 3154 driver model. So CONFIG_DM needs to be enabled by default for this 3155 library to function. 3156 3157 The signing part is build into mkimage regardless of this 3158 option. The software based modular exponentiation is built into 3159 mkimage irrespective of this option. 3160 3161- bootcount support: 3162 CONFIG_BOOTCOUNT_LIMIT 3163 3164 This enables the bootcounter support, see: 3165 http://www.denx.de/wiki/DULG/UBootBootCountLimit 3166 3167 CONFIG_AT91SAM9XE 3168 enable special bootcounter support on at91sam9xe based boards. 3169 CONFIG_BLACKFIN 3170 enable special bootcounter support on blackfin based boards. 3171 CONFIG_SOC_DA8XX 3172 enable special bootcounter support on da850 based boards. 3173 CONFIG_BOOTCOUNT_RAM 3174 enable support for the bootcounter in RAM 3175 CONFIG_BOOTCOUNT_I2C 3176 enable support for the bootcounter on an i2c (like RTC) device. 3177 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 3178 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 3179 the bootcounter. 3180 CONFIG_BOOTCOUNT_ALEN = address len 3181 3182- Show boot progress: 3183 CONFIG_SHOW_BOOT_PROGRESS 3184 3185 Defining this option allows to add some board- 3186 specific code (calling a user-provided function 3187 "show_boot_progress(int)") that enables you to show 3188 the system's boot progress on some display (for 3189 example, some LED's) on your board. At the moment, 3190 the following checkpoints are implemented: 3191 3192 3193Legacy uImage format: 3194 3195 Arg Where When 3196 1 common/cmd_bootm.c before attempting to boot an image 3197 -1 common/cmd_bootm.c Image header has bad magic number 3198 2 common/cmd_bootm.c Image header has correct magic number 3199 -2 common/cmd_bootm.c Image header has bad checksum 3200 3 common/cmd_bootm.c Image header has correct checksum 3201 -3 common/cmd_bootm.c Image data has bad checksum 3202 4 common/cmd_bootm.c Image data has correct checksum 3203 -4 common/cmd_bootm.c Image is for unsupported architecture 3204 5 common/cmd_bootm.c Architecture check OK 3205 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 3206 6 common/cmd_bootm.c Image Type check OK 3207 -6 common/cmd_bootm.c gunzip uncompression error 3208 -7 common/cmd_bootm.c Unimplemented compression type 3209 7 common/cmd_bootm.c Uncompression OK 3210 8 common/cmd_bootm.c No uncompress/copy overwrite error 3211 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 3212 3213 9 common/image.c Start initial ramdisk verification 3214 -10 common/image.c Ramdisk header has bad magic number 3215 -11 common/image.c Ramdisk header has bad checksum 3216 10 common/image.c Ramdisk header is OK 3217 -12 common/image.c Ramdisk data has bad checksum 3218 11 common/image.c Ramdisk data has correct checksum 3219 12 common/image.c Ramdisk verification complete, start loading 3220 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 3221 13 common/image.c Start multifile image verification 3222 14 common/image.c No initial ramdisk, no multifile, continue. 3223 3224 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 3225 3226 -30 arch/powerpc/lib/board.c Fatal error, hang the system 3227 -31 post/post.c POST test failed, detected by post_output_backlog() 3228 -32 post/post.c POST test failed, detected by post_run_single() 3229 3230 34 common/cmd_doc.c before loading a Image from a DOC device 3231 -35 common/cmd_doc.c Bad usage of "doc" command 3232 35 common/cmd_doc.c correct usage of "doc" command 3233 -36 common/cmd_doc.c No boot device 3234 36 common/cmd_doc.c correct boot device 3235 -37 common/cmd_doc.c Unknown Chip ID on boot device 3236 37 common/cmd_doc.c correct chip ID found, device available 3237 -38 common/cmd_doc.c Read Error on boot device 3238 38 common/cmd_doc.c reading Image header from DOC device OK 3239 -39 common/cmd_doc.c Image header has bad magic number 3240 39 common/cmd_doc.c Image header has correct magic number 3241 -40 common/cmd_doc.c Error reading Image from DOC device 3242 40 common/cmd_doc.c Image header has correct magic number 3243 41 common/cmd_ide.c before loading a Image from a IDE device 3244 -42 common/cmd_ide.c Bad usage of "ide" command 3245 42 common/cmd_ide.c correct usage of "ide" command 3246 -43 common/cmd_ide.c No boot device 3247 43 common/cmd_ide.c boot device found 3248 -44 common/cmd_ide.c Device not available 3249 44 common/cmd_ide.c Device available 3250 -45 common/cmd_ide.c wrong partition selected 3251 45 common/cmd_ide.c partition selected 3252 -46 common/cmd_ide.c Unknown partition table 3253 46 common/cmd_ide.c valid partition table found 3254 -47 common/cmd_ide.c Invalid partition type 3255 47 common/cmd_ide.c correct partition type 3256 -48 common/cmd_ide.c Error reading Image Header on boot device 3257 48 common/cmd_ide.c reading Image Header from IDE device OK 3258 -49 common/cmd_ide.c Image header has bad magic number 3259 49 common/cmd_ide.c Image header has correct magic number 3260 -50 common/cmd_ide.c Image header has bad checksum 3261 50 common/cmd_ide.c Image header has correct checksum 3262 -51 common/cmd_ide.c Error reading Image from IDE device 3263 51 common/cmd_ide.c reading Image from IDE device OK 3264 52 common/cmd_nand.c before loading a Image from a NAND device 3265 -53 common/cmd_nand.c Bad usage of "nand" command 3266 53 common/cmd_nand.c correct usage of "nand" command 3267 -54 common/cmd_nand.c No boot device 3268 54 common/cmd_nand.c boot device found 3269 -55 common/cmd_nand.c Unknown Chip ID on boot device 3270 55 common/cmd_nand.c correct chip ID found, device available 3271 -56 common/cmd_nand.c Error reading Image Header on boot device 3272 56 common/cmd_nand.c reading Image Header from NAND device OK 3273 -57 common/cmd_nand.c Image header has bad magic number 3274 57 common/cmd_nand.c Image header has correct magic number 3275 -58 common/cmd_nand.c Error reading Image from NAND device 3276 58 common/cmd_nand.c reading Image from NAND device OK 3277 3278 -60 common/env_common.c Environment has a bad CRC, using default 3279 3280 64 net/eth.c starting with Ethernet configuration. 3281 -64 net/eth.c no Ethernet found. 3282 65 net/eth.c Ethernet found. 3283 3284 -80 common/cmd_net.c usage wrong 3285 80 common/cmd_net.c before calling net_loop() 3286 -81 common/cmd_net.c some error in net_loop() occurred 3287 81 common/cmd_net.c net_loop() back without error 3288 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 3289 82 common/cmd_net.c trying automatic boot 3290 83 common/cmd_net.c running "source" command 3291 -83 common/cmd_net.c some error in automatic boot or "source" command 3292 84 common/cmd_net.c end without errors 3293 3294FIT uImage format: 3295 3296 Arg Where When 3297 100 common/cmd_bootm.c Kernel FIT Image has correct format 3298 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 3299 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 3300 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 3301 102 common/cmd_bootm.c Kernel unit name specified 3302 -103 common/cmd_bootm.c Can't get kernel subimage node offset 3303 103 common/cmd_bootm.c Found configuration node 3304 104 common/cmd_bootm.c Got kernel subimage node offset 3305 -104 common/cmd_bootm.c Kernel subimage hash verification failed 3306 105 common/cmd_bootm.c Kernel subimage hash verification OK 3307 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 3308 106 common/cmd_bootm.c Architecture check OK 3309 -106 common/cmd_bootm.c Kernel subimage has wrong type 3310 107 common/cmd_bootm.c Kernel subimage type OK 3311 -107 common/cmd_bootm.c Can't get kernel subimage data/size 3312 108 common/cmd_bootm.c Got kernel subimage data/size 3313 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 3314 -109 common/cmd_bootm.c Can't get kernel subimage type 3315 -110 common/cmd_bootm.c Can't get kernel subimage comp 3316 -111 common/cmd_bootm.c Can't get kernel subimage os 3317 -112 common/cmd_bootm.c Can't get kernel subimage load address 3318 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 3319 3320 120 common/image.c Start initial ramdisk verification 3321 -120 common/image.c Ramdisk FIT image has incorrect format 3322 121 common/image.c Ramdisk FIT image has correct format 3323 122 common/image.c No ramdisk subimage unit name, using configuration 3324 -122 common/image.c Can't get configuration for ramdisk subimage 3325 123 common/image.c Ramdisk unit name specified 3326 -124 common/image.c Can't get ramdisk subimage node offset 3327 125 common/image.c Got ramdisk subimage node offset 3328 -125 common/image.c Ramdisk subimage hash verification failed 3329 126 common/image.c Ramdisk subimage hash verification OK 3330 -126 common/image.c Ramdisk subimage for unsupported architecture 3331 127 common/image.c Architecture check OK 3332 -127 common/image.c Can't get ramdisk subimage data/size 3333 128 common/image.c Got ramdisk subimage data/size 3334 129 common/image.c Can't get ramdisk load address 3335 -129 common/image.c Got ramdisk load address 3336 3337 -130 common/cmd_doc.c Incorrect FIT image format 3338 131 common/cmd_doc.c FIT image format OK 3339 3340 -140 common/cmd_ide.c Incorrect FIT image format 3341 141 common/cmd_ide.c FIT image format OK 3342 3343 -150 common/cmd_nand.c Incorrect FIT image format 3344 151 common/cmd_nand.c FIT image format OK 3345 3346- legacy image format: 3347 CONFIG_IMAGE_FORMAT_LEGACY 3348 enables the legacy image format support in U-Boot. 3349 3350 Default: 3351 enabled if CONFIG_FIT_SIGNATURE is not defined. 3352 3353 CONFIG_DISABLE_IMAGE_LEGACY 3354 disable the legacy image format 3355 3356 This define is introduced, as the legacy image format is 3357 enabled per default for backward compatibility. 3358 3359- FIT image support: 3360 CONFIG_FIT 3361 Enable support for the FIT uImage format. 3362 3363 CONFIG_FIT_BEST_MATCH 3364 When no configuration is explicitly selected, default to the 3365 one whose fdt's compatibility field best matches that of 3366 U-Boot itself. A match is considered "best" if it matches the 3367 most specific compatibility entry of U-Boot's fdt's root node. 3368 The order of entries in the configuration's fdt is ignored. 3369 3370 CONFIG_FIT_SIGNATURE 3371 This option enables signature verification of FIT uImages, 3372 using a hash signed and verified using RSA. If 3373 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive 3374 hashing is available using hardware, RSA library will use it. 3375 See doc/uImage.FIT/signature.txt for more details. 3376 3377 WARNING: When relying on signed FIT images with required 3378 signature check the legacy image format is default 3379 disabled. If a board need legacy image format support 3380 enable this through CONFIG_IMAGE_FORMAT_LEGACY 3381 3382 CONFIG_FIT_DISABLE_SHA256 3383 Supporting SHA256 hashes has quite an impact on binary size. 3384 For constrained systems sha256 hash support can be disabled 3385 with this option. 3386 3387- Standalone program support: 3388 CONFIG_STANDALONE_LOAD_ADDR 3389 3390 This option defines a board specific value for the 3391 address where standalone program gets loaded, thus 3392 overwriting the architecture dependent default 3393 settings. 3394 3395- Frame Buffer Address: 3396 CONFIG_FB_ADDR 3397 3398 Define CONFIG_FB_ADDR if you want to use specific 3399 address for frame buffer. This is typically the case 3400 when using a graphics controller has separate video 3401 memory. U-Boot will then place the frame buffer at 3402 the given address instead of dynamically reserving it 3403 in system RAM by calling lcd_setmem(), which grabs 3404 the memory for the frame buffer depending on the 3405 configured panel size. 3406 3407 Please see board_init_f function. 3408 3409- Automatic software updates via TFTP server 3410 CONFIG_UPDATE_TFTP 3411 CONFIG_UPDATE_TFTP_CNT_MAX 3412 CONFIG_UPDATE_TFTP_MSEC_MAX 3413 3414 These options enable and control the auto-update feature; 3415 for a more detailed description refer to doc/README.update. 3416 3417- MTD Support (mtdparts command, UBI support) 3418 CONFIG_MTD_DEVICE 3419 3420 Adds the MTD device infrastructure from the Linux kernel. 3421 Needed for mtdparts command support. 3422 3423 CONFIG_MTD_PARTITIONS 3424 3425 Adds the MTD partitioning infrastructure from the Linux 3426 kernel. Needed for UBI support. 3427 3428- UBI support 3429 CONFIG_CMD_UBI 3430 3431 Adds commands for interacting with MTD partitions formatted 3432 with the UBI flash translation layer 3433 3434 Requires also defining CONFIG_RBTREE 3435 3436 CONFIG_UBI_SILENCE_MSG 3437 3438 Make the verbose messages from UBI stop printing. This leaves 3439 warnings and errors enabled. 3440 3441 3442 CONFIG_MTD_UBI_WL_THRESHOLD 3443 This parameter defines the maximum difference between the highest 3444 erase counter value and the lowest erase counter value of eraseblocks 3445 of UBI devices. When this threshold is exceeded, UBI starts performing 3446 wear leveling by means of moving data from eraseblock with low erase 3447 counter to eraseblocks with high erase counter. 3448 3449 The default value should be OK for SLC NAND flashes, NOR flashes and 3450 other flashes which have eraseblock life-cycle 100000 or more. 3451 However, in case of MLC NAND flashes which typically have eraseblock 3452 life-cycle less than 10000, the threshold should be lessened (e.g., 3453 to 128 or 256, although it does not have to be power of 2). 3454 3455 default: 4096 3456 3457 CONFIG_MTD_UBI_BEB_LIMIT 3458 This option specifies the maximum bad physical eraseblocks UBI 3459 expects on the MTD device (per 1024 eraseblocks). If the 3460 underlying flash does not admit of bad eraseblocks (e.g. NOR 3461 flash), this value is ignored. 3462 3463 NAND datasheets often specify the minimum and maximum NVM 3464 (Number of Valid Blocks) for the flashes' endurance lifetime. 3465 The maximum expected bad eraseblocks per 1024 eraseblocks 3466 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 3467 which gives 20 for most NANDs (MaxNVB is basically the total 3468 count of eraseblocks on the chip). 3469 3470 To put it differently, if this value is 20, UBI will try to 3471 reserve about 1.9% of physical eraseblocks for bad blocks 3472 handling. And that will be 1.9% of eraseblocks on the entire 3473 NAND chip, not just the MTD partition UBI attaches. This means 3474 that if you have, say, a NAND flash chip admits maximum 40 bad 3475 eraseblocks, and it is split on two MTD partitions of the same 3476 size, UBI will reserve 40 eraseblocks when attaching a 3477 partition. 3478 3479 default: 20 3480 3481 CONFIG_MTD_UBI_FASTMAP 3482 Fastmap is a mechanism which allows attaching an UBI device 3483 in nearly constant time. Instead of scanning the whole MTD device it 3484 only has to locate a checkpoint (called fastmap) on the device. 3485 The on-flash fastmap contains all information needed to attach 3486 the device. Using fastmap makes only sense on large devices where 3487 attaching by scanning takes long. UBI will not automatically install 3488 a fastmap on old images, but you can set the UBI parameter 3489 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 3490 that fastmap-enabled images are still usable with UBI implementations 3491 without fastmap support. On typical flash devices the whole fastmap 3492 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 3493 3494 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 3495 Set this parameter to enable fastmap automatically on images 3496 without a fastmap. 3497 default: 0 3498 3499- UBIFS support 3500 CONFIG_CMD_UBIFS 3501 3502 Adds commands for interacting with UBI volumes formatted as 3503 UBIFS. UBIFS is read-only in u-boot. 3504 3505 Requires UBI support as well as CONFIG_LZO 3506 3507 CONFIG_UBIFS_SILENCE_MSG 3508 3509 Make the verbose messages from UBIFS stop printing. This leaves 3510 warnings and errors enabled. 3511 3512- SPL framework 3513 CONFIG_SPL 3514 Enable building of SPL globally. 3515 3516 CONFIG_SPL_LDSCRIPT 3517 LDSCRIPT for linking the SPL binary. 3518 3519 CONFIG_SPL_MAX_FOOTPRINT 3520 Maximum size in memory allocated to the SPL, BSS included. 3521 When defined, the linker checks that the actual memory 3522 used by SPL from _start to __bss_end does not exceed it. 3523 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3524 must not be both defined at the same time. 3525 3526 CONFIG_SPL_MAX_SIZE 3527 Maximum size of the SPL image (text, data, rodata, and 3528 linker lists sections), BSS excluded. 3529 When defined, the linker checks that the actual size does 3530 not exceed it. 3531 3532 CONFIG_SPL_TEXT_BASE 3533 TEXT_BASE for linking the SPL binary. 3534 3535 CONFIG_SPL_RELOC_TEXT_BASE 3536 Address to relocate to. If unspecified, this is equal to 3537 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 3538 3539 CONFIG_SPL_BSS_START_ADDR 3540 Link address for the BSS within the SPL binary. 3541 3542 CONFIG_SPL_BSS_MAX_SIZE 3543 Maximum size in memory allocated to the SPL BSS. 3544 When defined, the linker checks that the actual memory used 3545 by SPL from __bss_start to __bss_end does not exceed it. 3546 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 3547 must not be both defined at the same time. 3548 3549 CONFIG_SPL_STACK 3550 Adress of the start of the stack SPL will use 3551 3552 CONFIG_SPL_PANIC_ON_RAW_IMAGE 3553 When defined, SPL will panic() if the image it has 3554 loaded does not have a signature. 3555 Defining this is useful when code which loads images 3556 in SPL cannot guarantee that absolutely all read errors 3557 will be caught. 3558 An example is the LPC32XX MLC NAND driver, which will 3559 consider that a completely unreadable NAND block is bad, 3560 and thus should be skipped silently. 3561 3562 CONFIG_SPL_RELOC_STACK 3563 Adress of the start of the stack SPL will use after 3564 relocation. If unspecified, this is equal to 3565 CONFIG_SPL_STACK. 3566 3567 CONFIG_SYS_SPL_MALLOC_START 3568 Starting address of the malloc pool used in SPL. 3569 3570 CONFIG_SYS_SPL_MALLOC_SIZE 3571 The size of the malloc pool used in SPL. 3572 3573 CONFIG_SPL_FRAMEWORK 3574 Enable the SPL framework under common/. This framework 3575 supports MMC, NAND and YMODEM loading of U-Boot and NAND 3576 NAND loading of the Linux Kernel. 3577 3578 CONFIG_SPL_OS_BOOT 3579 Enable booting directly to an OS from SPL. 3580 See also: doc/README.falcon 3581 3582 CONFIG_SPL_DISPLAY_PRINT 3583 For ARM, enable an optional function to print more information 3584 about the running system. 3585 3586 CONFIG_SPL_INIT_MINIMAL 3587 Arch init code should be built for a very small image 3588 3589 CONFIG_SPL_LIBCOMMON_SUPPORT 3590 Support for common/libcommon.o in SPL binary 3591 3592 CONFIG_SPL_LIBDISK_SUPPORT 3593 Support for disk/libdisk.o in SPL binary 3594 3595 CONFIG_SPL_I2C_SUPPORT 3596 Support for drivers/i2c/libi2c.o in SPL binary 3597 3598 CONFIG_SPL_GPIO_SUPPORT 3599 Support for drivers/gpio/libgpio.o in SPL binary 3600 3601 CONFIG_SPL_MMC_SUPPORT 3602 Support for drivers/mmc/libmmc.o in SPL binary 3603 3604 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR, 3605 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS, 3606 Address and partition on the MMC to load U-Boot from 3607 when the MMC is being used in raw mode. 3608 3609 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 3610 Partition on the MMC to load U-Boot from when the MMC is being 3611 used in raw mode 3612 3613 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 3614 Sector to load kernel uImage from when MMC is being 3615 used in raw mode (for Falcon mode) 3616 3617 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3618 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3619 Sector and number of sectors to load kernel argument 3620 parameters from when MMC is being used in raw mode 3621 (for falcon mode) 3622 3623 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3624 Partition on the MMC to load U-Boot from when the MMC is being 3625 used in fs mode 3626 3627 CONFIG_SPL_FAT_SUPPORT 3628 Support for fs/fat/libfat.o in SPL binary 3629 3630 CONFIG_SPL_EXT_SUPPORT 3631 Support for EXT filesystem in SPL binary 3632 3633 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3634 Filename to read to load U-Boot when reading from filesystem 3635 3636 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3637 Filename to read to load kernel uImage when reading 3638 from filesystem (for Falcon mode) 3639 3640 CONFIG_SPL_FS_LOAD_ARGS_NAME 3641 Filename to read to load kernel argument parameters 3642 when reading from filesystem (for Falcon mode) 3643 3644 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3645 Set this for NAND SPL on PPC mpc83xx targets, so that 3646 start.S waits for the rest of the SPL to load before 3647 continuing (the hardware starts execution after just 3648 loading the first page rather than the full 4K). 3649 3650 CONFIG_SPL_SKIP_RELOCATE 3651 Avoid SPL relocation 3652 3653 CONFIG_SPL_NAND_BASE 3654 Include nand_base.c in the SPL. Requires 3655 CONFIG_SPL_NAND_DRIVERS. 3656 3657 CONFIG_SPL_NAND_DRIVERS 3658 SPL uses normal NAND drivers, not minimal drivers. 3659 3660 CONFIG_SPL_NAND_ECC 3661 Include standard software ECC in the SPL 3662 3663 CONFIG_SPL_NAND_SIMPLE 3664 Support for NAND boot using simple NAND drivers that 3665 expose the cmd_ctrl() interface. 3666 3667 CONFIG_SPL_MTD_SUPPORT 3668 Support for the MTD subsystem within SPL. Useful for 3669 environment on NAND support within SPL. 3670 3671 CONFIG_SPL_NAND_RAW_ONLY 3672 Support to boot only raw u-boot.bin images. Use this only 3673 if you need to save space. 3674 3675 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT 3676 Set for the SPL on PPC mpc8xxx targets, support for 3677 drivers/ddr/fsl/libddr.o in SPL binary. 3678 3679 CONFIG_SPL_COMMON_INIT_DDR 3680 Set for common ddr init with serial presence detect in 3681 SPL binary. 3682 3683 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3684 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3685 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3686 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3687 CONFIG_SYS_NAND_ECCBYTES 3688 Defines the size and behavior of the NAND that SPL uses 3689 to read U-Boot 3690 3691 CONFIG_SPL_NAND_BOOT 3692 Add support NAND boot 3693 3694 CONFIG_SYS_NAND_U_BOOT_OFFS 3695 Location in NAND to read U-Boot from 3696 3697 CONFIG_SYS_NAND_U_BOOT_DST 3698 Location in memory to load U-Boot to 3699 3700 CONFIG_SYS_NAND_U_BOOT_SIZE 3701 Size of image to load 3702 3703 CONFIG_SYS_NAND_U_BOOT_START 3704 Entry point in loaded image to jump to 3705 3706 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3707 Define this if you need to first read the OOB and then the 3708 data. This is used, for example, on davinci platforms. 3709 3710 CONFIG_SPL_OMAP3_ID_NAND 3711 Support for an OMAP3-specific set of functions to return the 3712 ID and MFR of the first attached NAND chip, if present. 3713 3714 CONFIG_SPL_SERIAL_SUPPORT 3715 Support for drivers/serial/libserial.o in SPL binary 3716 3717 CONFIG_SPL_SPI_FLASH_SUPPORT 3718 Support for drivers/mtd/spi/libspi_flash.o in SPL binary 3719 3720 CONFIG_SPL_SPI_SUPPORT 3721 Support for drivers/spi/libspi.o in SPL binary 3722 3723 CONFIG_SPL_RAM_DEVICE 3724 Support for running image already present in ram, in SPL binary 3725 3726 CONFIG_SPL_LIBGENERIC_SUPPORT 3727 Support for lib/libgeneric.o in SPL binary 3728 3729 CONFIG_SPL_ENV_SUPPORT 3730 Support for the environment operating in SPL binary 3731 3732 CONFIG_SPL_NET_SUPPORT 3733 Support for the net/libnet.o in SPL binary. 3734 It conflicts with SPL env from storage medium specified by 3735 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE 3736 3737 CONFIG_SPL_PAD_TO 3738 Image offset to which the SPL should be padded before appending 3739 the SPL payload. By default, this is defined as 3740 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3741 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3742 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3743 3744 CONFIG_SPL_TARGET 3745 Final target image containing SPL and payload. Some SPLs 3746 use an arch-specific makefile fragment instead, for 3747 example if more than one image needs to be produced. 3748 3749 CONFIG_FIT_SPL_PRINT 3750 Printing information about a FIT image adds quite a bit of 3751 code to SPL. So this is normally disabled in SPL. Use this 3752 option to re-enable it. This will affect the output of the 3753 bootm command when booting a FIT image. 3754 3755- TPL framework 3756 CONFIG_TPL 3757 Enable building of TPL globally. 3758 3759 CONFIG_TPL_PAD_TO 3760 Image offset to which the TPL should be padded before appending 3761 the TPL payload. By default, this is defined as 3762 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3763 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3764 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3765 3766Modem Support: 3767-------------- 3768 3769[so far only for SMDK2400 boards] 3770 3771- Modem support enable: 3772 CONFIG_MODEM_SUPPORT 3773 3774- RTS/CTS Flow control enable: 3775 CONFIG_HWFLOW 3776 3777- Modem debug support: 3778 CONFIG_MODEM_SUPPORT_DEBUG 3779 3780 Enables debugging stuff (char screen[1024], dbg()) 3781 for modem support. Useful only with BDI2000. 3782 3783- Interrupt support (PPC): 3784 3785 There are common interrupt_init() and timer_interrupt() 3786 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3787 for CPU specific initialization. interrupt_init_cpu() 3788 should set decrementer_count to appropriate value. If 3789 CPU resets decrementer automatically after interrupt 3790 (ppc4xx) it should set decrementer_count to zero. 3791 timer_interrupt() calls timer_interrupt_cpu() for CPU 3792 specific handling. If board has watchdog / status_led 3793 / other_activity_monitor it works automatically from 3794 general timer_interrupt(). 3795 3796- General: 3797 3798 In the target system modem support is enabled when a 3799 specific key (key combination) is pressed during 3800 power-on. Otherwise U-Boot will boot normally 3801 (autoboot). The key_pressed() function is called from 3802 board_init(). Currently key_pressed() is a dummy 3803 function, returning 1 and thus enabling modem 3804 initialization. 3805 3806 If there are no modem init strings in the 3807 environment, U-Boot proceed to autoboot; the 3808 previous output (banner, info printfs) will be 3809 suppressed, though. 3810 3811 See also: doc/README.Modem 3812 3813Board initialization settings: 3814------------------------------ 3815 3816During Initialization u-boot calls a number of board specific functions 3817to allow the preparation of board specific prerequisites, e.g. pin setup 3818before drivers are initialized. To enable these callbacks the 3819following configuration macros have to be defined. Currently this is 3820architecture specific, so please check arch/your_architecture/lib/board.c 3821typically in board_init_f() and board_init_r(). 3822 3823- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3824- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3825- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3826- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3827 3828Configuration Settings: 3829----------------------- 3830 3831- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3832 Optionally it can be defined to support 64-bit memory commands. 3833 3834- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3835 undefine this when you're short of memory. 3836 3837- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3838 width of the commands listed in the 'help' command output. 3839 3840- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3841 prompt for user input. 3842 3843- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3844 3845- CONFIG_SYS_PBSIZE: Buffer size for Console output 3846 3847- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3848 3849- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3850 the application (usually a Linux kernel) when it is 3851 booted 3852 3853- CONFIG_SYS_BAUDRATE_TABLE: 3854 List of legal baudrate settings for this board. 3855 3856- CONFIG_SYS_CONSOLE_INFO_QUIET 3857 Suppress display of console information at boot. 3858 3859- CONFIG_SYS_CONSOLE_IS_IN_ENV 3860 If the board specific function 3861 extern int overwrite_console (void); 3862 returns 1, the stdin, stderr and stdout are switched to the 3863 serial port, else the settings in the environment are used. 3864 3865- CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE 3866 Enable the call to overwrite_console(). 3867 3868- CONFIG_SYS_CONSOLE_ENV_OVERWRITE 3869 Enable overwrite of previous console environment settings. 3870 3871- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3872 Begin and End addresses of the area used by the 3873 simple memory test. 3874 3875- CONFIG_SYS_ALT_MEMTEST: 3876 Enable an alternate, more extensive memory test. 3877 3878- CONFIG_SYS_MEMTEST_SCRATCH: 3879 Scratch address used by the alternate memory test 3880 You only need to set this if address zero isn't writeable 3881 3882- CONFIG_SYS_MEM_TOP_HIDE (PPC only): 3883 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3884 this specified memory area will get subtracted from the top 3885 (end) of RAM and won't get "touched" at all by U-Boot. By 3886 fixing up gd->ram_size the Linux kernel should gets passed 3887 the now "corrected" memory size and won't touch it either. 3888 This should work for arch/ppc and arch/powerpc. Only Linux 3889 board ports in arch/powerpc with bootwrapper support that 3890 recalculate the memory size from the SDRAM controller setup 3891 will have to get fixed in Linux additionally. 3892 3893 This option can be used as a workaround for the 440EPx/GRx 3894 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3895 be touched. 3896 3897 WARNING: Please make sure that this value is a multiple of 3898 the Linux page size (normally 4k). If this is not the case, 3899 then the end address of the Linux memory will be located at a 3900 non page size aligned address and this could cause major 3901 problems. 3902 3903- CONFIG_SYS_LOADS_BAUD_CHANGE: 3904 Enable temporary baudrate change while serial download 3905 3906- CONFIG_SYS_SDRAM_BASE: 3907 Physical start address of SDRAM. _Must_ be 0 here. 3908 3909- CONFIG_SYS_MBIO_BASE: 3910 Physical start address of Motherboard I/O (if using a 3911 Cogent motherboard) 3912 3913- CONFIG_SYS_FLASH_BASE: 3914 Physical start address of Flash memory. 3915 3916- CONFIG_SYS_MONITOR_BASE: 3917 Physical start address of boot monitor code (set by 3918 make config files to be same as the text base address 3919 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3920 CONFIG_SYS_FLASH_BASE when booting from flash. 3921 3922- CONFIG_SYS_MONITOR_LEN: 3923 Size of memory reserved for monitor code, used to 3924 determine _at_compile_time_ (!) if the environment is 3925 embedded within the U-Boot image, or in a separate 3926 flash sector. 3927 3928- CONFIG_SYS_MALLOC_LEN: 3929 Size of DRAM reserved for malloc() use. 3930 3931- CONFIG_SYS_MALLOC_F_LEN 3932 Size of the malloc() pool for use before relocation. If 3933 this is defined, then a very simple malloc() implementation 3934 will become available before relocation. The address is just 3935 below the global data, and the stack is moved down to make 3936 space. 3937 3938 This feature allocates regions with increasing addresses 3939 within the region. calloc() is supported, but realloc() 3940 is not available. free() is supported but does nothing. 3941 The memory will be freed (or in fact just forgotten) when 3942 U-Boot relocates itself. 3943 3944 Pre-relocation malloc() is only supported on ARM and sandbox 3945 at present but is fairly easy to enable for other archs. 3946 3947- CONFIG_SYS_MALLOC_SIMPLE 3948 Provides a simple and small malloc() and calloc() for those 3949 boards which do not use the full malloc in SPL (which is 3950 enabled with CONFIG_SYS_SPL_MALLOC_START). 3951 3952- CONFIG_SYS_NONCACHED_MEMORY: 3953 Size of non-cached memory area. This area of memory will be 3954 typically located right below the malloc() area and mapped 3955 uncached in the MMU. This is useful for drivers that would 3956 otherwise require a lot of explicit cache maintenance. For 3957 some drivers it's also impossible to properly maintain the 3958 cache. For example if the regions that need to be flushed 3959 are not a multiple of the cache-line size, *and* padding 3960 cannot be allocated between the regions to align them (i.e. 3961 if the HW requires a contiguous array of regions, and the 3962 size of each region is not cache-aligned), then a flush of 3963 one region may result in overwriting data that hardware has 3964 written to another region in the same cache-line. This can 3965 happen for example in network drivers where descriptors for 3966 buffers are typically smaller than the CPU cache-line (e.g. 3967 16 bytes vs. 32 or 64 bytes). 3968 3969 Non-cached memory is only supported on 32-bit ARM at present. 3970 3971- CONFIG_SYS_BOOTM_LEN: 3972 Normally compressed uImages are limited to an 3973 uncompressed size of 8 MBytes. If this is not enough, 3974 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3975 to adjust this setting to your needs. 3976 3977- CONFIG_SYS_BOOTMAPSZ: 3978 Maximum size of memory mapped by the startup code of 3979 the Linux kernel; all data that must be processed by 3980 the Linux kernel (bd_info, boot arguments, FDT blob if 3981 used) must be put below this limit, unless "bootm_low" 3982 environment variable is defined and non-zero. In such case 3983 all data for the Linux kernel must be between "bootm_low" 3984 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3985 variable "bootm_mapsize" will override the value of 3986 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3987 then the value in "bootm_size" will be used instead. 3988 3989- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3990 Enable initrd_high functionality. If defined then the 3991 initrd_high feature is enabled and the bootm ramdisk subcommand 3992 is enabled. 3993 3994- CONFIG_SYS_BOOT_GET_CMDLINE: 3995 Enables allocating and saving kernel cmdline in space between 3996 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3997 3998- CONFIG_SYS_BOOT_GET_KBD: 3999 Enables allocating and saving a kernel copy of the bd_info in 4000 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 4001 4002- CONFIG_SYS_MAX_FLASH_BANKS: 4003 Max number of Flash memory banks 4004 4005- CONFIG_SYS_MAX_FLASH_SECT: 4006 Max number of sectors on a Flash chip 4007 4008- CONFIG_SYS_FLASH_ERASE_TOUT: 4009 Timeout for Flash erase operations (in ms) 4010 4011- CONFIG_SYS_FLASH_WRITE_TOUT: 4012 Timeout for Flash write operations (in ms) 4013 4014- CONFIG_SYS_FLASH_LOCK_TOUT 4015 Timeout for Flash set sector lock bit operation (in ms) 4016 4017- CONFIG_SYS_FLASH_UNLOCK_TOUT 4018 Timeout for Flash clear lock bits operation (in ms) 4019 4020- CONFIG_SYS_FLASH_PROTECTION 4021 If defined, hardware flash sectors protection is used 4022 instead of U-Boot software protection. 4023 4024- CONFIG_SYS_DIRECT_FLASH_TFTP: 4025 4026 Enable TFTP transfers directly to flash memory; 4027 without this option such a download has to be 4028 performed in two steps: (1) download to RAM, and (2) 4029 copy from RAM to flash. 4030 4031 The two-step approach is usually more reliable, since 4032 you can check if the download worked before you erase 4033 the flash, but in some situations (when system RAM is 4034 too limited to allow for a temporary copy of the 4035 downloaded image) this option may be very useful. 4036 4037- CONFIG_SYS_FLASH_CFI: 4038 Define if the flash driver uses extra elements in the 4039 common flash structure for storing flash geometry. 4040 4041- CONFIG_FLASH_CFI_DRIVER 4042 This option also enables the building of the cfi_flash driver 4043 in the drivers directory 4044 4045- CONFIG_FLASH_CFI_MTD 4046 This option enables the building of the cfi_mtd driver 4047 in the drivers directory. The driver exports CFI flash 4048 to the MTD layer. 4049 4050- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 4051 Use buffered writes to flash. 4052 4053- CONFIG_FLASH_SPANSION_S29WS_N 4054 s29ws-n MirrorBit flash has non-standard addresses for buffered 4055 write commands. 4056 4057- CONFIG_SYS_FLASH_QUIET_TEST 4058 If this option is defined, the common CFI flash doesn't 4059 print it's warning upon not recognized FLASH banks. This 4060 is useful, if some of the configured banks are only 4061 optionally available. 4062 4063- CONFIG_FLASH_SHOW_PROGRESS 4064 If defined (must be an integer), print out countdown 4065 digits and dots. Recommended value: 45 (9..1) for 80 4066 column displays, 15 (3..1) for 40 column displays. 4067 4068- CONFIG_FLASH_VERIFY 4069 If defined, the content of the flash (destination) is compared 4070 against the source after the write operation. An error message 4071 will be printed when the contents are not identical. 4072 Please note that this option is useless in nearly all cases, 4073 since such flash programming errors usually are detected earlier 4074 while unprotecting/erasing/programming. Please only enable 4075 this option if you really know what you are doing. 4076 4077- CONFIG_SYS_RX_ETH_BUFFER: 4078 Defines the number of Ethernet receive buffers. On some 4079 Ethernet controllers it is recommended to set this value 4080 to 8 or even higher (EEPRO100 or 405 EMAC), since all 4081 buffers can be full shortly after enabling the interface 4082 on high Ethernet traffic. 4083 Defaults to 4 if not defined. 4084 4085- CONFIG_ENV_MAX_ENTRIES 4086 4087 Maximum number of entries in the hash table that is used 4088 internally to store the environment settings. The default 4089 setting is supposed to be generous and should work in most 4090 cases. This setting can be used to tune behaviour; see 4091 lib/hashtable.c for details. 4092 4093- CONFIG_ENV_FLAGS_LIST_DEFAULT 4094- CONFIG_ENV_FLAGS_LIST_STATIC 4095 Enable validation of the values given to environment variables when 4096 calling env set. Variables can be restricted to only decimal, 4097 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 4098 the variables can also be restricted to IP address or MAC address. 4099 4100 The format of the list is: 4101 type_attribute = [s|d|x|b|i|m] 4102 access_attribute = [a|r|o|c] 4103 attributes = type_attribute[access_attribute] 4104 entry = variable_name[:attributes] 4105 list = entry[,list] 4106 4107 The type attributes are: 4108 s - String (default) 4109 d - Decimal 4110 x - Hexadecimal 4111 b - Boolean ([1yYtT|0nNfF]) 4112 i - IP address 4113 m - MAC address 4114 4115 The access attributes are: 4116 a - Any (default) 4117 r - Read-only 4118 o - Write-once 4119 c - Change-default 4120 4121 - CONFIG_ENV_FLAGS_LIST_DEFAULT 4122 Define this to a list (string) to define the ".flags" 4123 environment variable in the default or embedded environment. 4124 4125 - CONFIG_ENV_FLAGS_LIST_STATIC 4126 Define this to a list (string) to define validation that 4127 should be done if an entry is not found in the ".flags" 4128 environment variable. To override a setting in the static 4129 list, simply add an entry for the same variable name to the 4130 ".flags" variable. 4131 4132 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4133 regular expression. This allows multiple variables to define the same 4134 flags without explicitly listing them for each variable. 4135 4136- CONFIG_ENV_ACCESS_IGNORE_FORCE 4137 If defined, don't allow the -f switch to env set override variable 4138 access flags. 4139 4140- CONFIG_SYS_GENERIC_BOARD 4141 This selects the architecture-generic board system instead of the 4142 architecture-specific board files. It is intended to move boards 4143 to this new framework over time. Defining this will disable the 4144 arch/foo/lib/board.c file and use common/board_f.c and 4145 common/board_r.c instead. To use this option your architecture 4146 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig). 4147 If you find problems enabling this option on your board please report 4148 the problem and send patches! 4149 4150- CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only) 4151 This is set by OMAP boards for the max time that reset should 4152 be asserted. See doc/README.omap-reset-time for details on how 4153 the value can be calculated on a given board. 4154 4155- CONFIG_USE_STDINT 4156 If stdint.h is available with your toolchain you can define this 4157 option to enable it. You can provide option 'USE_STDINT=1' when 4158 building U-Boot to enable this. 4159 4160The following definitions that deal with the placement and management 4161of environment data (variable area); in general, we support the 4162following configurations: 4163 4164- CONFIG_BUILD_ENVCRC: 4165 4166 Builds up envcrc with the target environment so that external utils 4167 may easily extract it and embed it in final U-Boot images. 4168 4169- CONFIG_ENV_IS_IN_FLASH: 4170 4171 Define this if the environment is in flash memory. 4172 4173 a) The environment occupies one whole flash sector, which is 4174 "embedded" in the text segment with the U-Boot code. This 4175 happens usually with "bottom boot sector" or "top boot 4176 sector" type flash chips, which have several smaller 4177 sectors at the start or the end. For instance, such a 4178 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 4179 such a case you would place the environment in one of the 4180 4 kB sectors - with U-Boot code before and after it. With 4181 "top boot sector" type flash chips, you would put the 4182 environment in one of the last sectors, leaving a gap 4183 between U-Boot and the environment. 4184 4185 - CONFIG_ENV_OFFSET: 4186 4187 Offset of environment data (variable area) to the 4188 beginning of flash memory; for instance, with bottom boot 4189 type flash chips the second sector can be used: the offset 4190 for this sector is given here. 4191 4192 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 4193 4194 - CONFIG_ENV_ADDR: 4195 4196 This is just another way to specify the start address of 4197 the flash sector containing the environment (instead of 4198 CONFIG_ENV_OFFSET). 4199 4200 - CONFIG_ENV_SECT_SIZE: 4201 4202 Size of the sector containing the environment. 4203 4204 4205 b) Sometimes flash chips have few, equal sized, BIG sectors. 4206 In such a case you don't want to spend a whole sector for 4207 the environment. 4208 4209 - CONFIG_ENV_SIZE: 4210 4211 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 4212 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 4213 of this flash sector for the environment. This saves 4214 memory for the RAM copy of the environment. 4215 4216 It may also save flash memory if you decide to use this 4217 when your environment is "embedded" within U-Boot code, 4218 since then the remainder of the flash sector could be used 4219 for U-Boot code. It should be pointed out that this is 4220 STRONGLY DISCOURAGED from a robustness point of view: 4221 updating the environment in flash makes it always 4222 necessary to erase the WHOLE sector. If something goes 4223 wrong before the contents has been restored from a copy in 4224 RAM, your target system will be dead. 4225 4226 - CONFIG_ENV_ADDR_REDUND 4227 CONFIG_ENV_SIZE_REDUND 4228 4229 These settings describe a second storage area used to hold 4230 a redundant copy of the environment data, so that there is 4231 a valid backup copy in case there is a power failure during 4232 a "saveenv" operation. 4233 4234BE CAREFUL! Any changes to the flash layout, and some changes to the 4235source code will make it necessary to adapt <board>/u-boot.lds* 4236accordingly! 4237 4238 4239- CONFIG_ENV_IS_IN_NVRAM: 4240 4241 Define this if you have some non-volatile memory device 4242 (NVRAM, battery buffered SRAM) which you want to use for the 4243 environment. 4244 4245 - CONFIG_ENV_ADDR: 4246 - CONFIG_ENV_SIZE: 4247 4248 These two #defines are used to determine the memory area you 4249 want to use for environment. It is assumed that this memory 4250 can just be read and written to, without any special 4251 provision. 4252 4253BE CAREFUL! The first access to the environment happens quite early 4254in U-Boot initialization (when we try to get the setting of for the 4255console baudrate). You *MUST* have mapped your NVRAM area then, or 4256U-Boot will hang. 4257 4258Please note that even with NVRAM we still use a copy of the 4259environment in RAM: we could work on NVRAM directly, but we want to 4260keep settings there always unmodified except somebody uses "saveenv" 4261to save the current settings. 4262 4263 4264- CONFIG_ENV_IS_IN_EEPROM: 4265 4266 Use this if you have an EEPROM or similar serial access 4267 device and a driver for it. 4268 4269 - CONFIG_ENV_OFFSET: 4270 - CONFIG_ENV_SIZE: 4271 4272 These two #defines specify the offset and size of the 4273 environment area within the total memory of your EEPROM. 4274 4275 - CONFIG_SYS_I2C_EEPROM_ADDR: 4276 If defined, specified the chip address of the EEPROM device. 4277 The default address is zero. 4278 4279 - CONFIG_SYS_I2C_EEPROM_BUS: 4280 If defined, specified the i2c bus of the EEPROM device. 4281 4282 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 4283 If defined, the number of bits used to address bytes in a 4284 single page in the EEPROM device. A 64 byte page, for example 4285 would require six bits. 4286 4287 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 4288 If defined, the number of milliseconds to delay between 4289 page writes. The default is zero milliseconds. 4290 4291 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 4292 The length in bytes of the EEPROM memory array address. Note 4293 that this is NOT the chip address length! 4294 4295 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 4296 EEPROM chips that implement "address overflow" are ones 4297 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 4298 address and the extra bits end up in the "chip address" bit 4299 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 4300 byte chips. 4301 4302 Note that we consider the length of the address field to 4303 still be one byte because the extra address bits are hidden 4304 in the chip address. 4305 4306 - CONFIG_SYS_EEPROM_SIZE: 4307 The size in bytes of the EEPROM device. 4308 4309 - CONFIG_ENV_EEPROM_IS_ON_I2C 4310 define this, if you have I2C and SPI activated, and your 4311 EEPROM, which holds the environment, is on the I2C bus. 4312 4313 - CONFIG_I2C_ENV_EEPROM_BUS 4314 if you have an Environment on an EEPROM reached over 4315 I2C muxes, you can define here, how to reach this 4316 EEPROM. For example: 4317 4318 #define CONFIG_I2C_ENV_EEPROM_BUS 1 4319 4320 EEPROM which holds the environment, is reached over 4321 a pca9547 i2c mux with address 0x70, channel 3. 4322 4323- CONFIG_ENV_IS_IN_DATAFLASH: 4324 4325 Define this if you have a DataFlash memory device which you 4326 want to use for the environment. 4327 4328 - CONFIG_ENV_OFFSET: 4329 - CONFIG_ENV_ADDR: 4330 - CONFIG_ENV_SIZE: 4331 4332 These three #defines specify the offset and size of the 4333 environment area within the total memory of your DataFlash placed 4334 at the specified address. 4335 4336- CONFIG_ENV_IS_IN_SPI_FLASH: 4337 4338 Define this if you have a SPI Flash memory device which you 4339 want to use for the environment. 4340 4341 - CONFIG_ENV_OFFSET: 4342 - CONFIG_ENV_SIZE: 4343 4344 These two #defines specify the offset and size of the 4345 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 4346 aligned to an erase sector boundary. 4347 4348 - CONFIG_ENV_SECT_SIZE: 4349 4350 Define the SPI flash's sector size. 4351 4352 - CONFIG_ENV_OFFSET_REDUND (optional): 4353 4354 This setting describes a second storage area of CONFIG_ENV_SIZE 4355 size used to hold a redundant copy of the environment data, so 4356 that there is a valid backup copy in case there is a power failure 4357 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be 4358 aligned to an erase sector boundary. 4359 4360 - CONFIG_ENV_SPI_BUS (optional): 4361 - CONFIG_ENV_SPI_CS (optional): 4362 4363 Define the SPI bus and chip select. If not defined they will be 0. 4364 4365 - CONFIG_ENV_SPI_MAX_HZ (optional): 4366 4367 Define the SPI max work clock. If not defined then use 1MHz. 4368 4369 - CONFIG_ENV_SPI_MODE (optional): 4370 4371 Define the SPI work mode. If not defined then use SPI_MODE_3. 4372 4373- CONFIG_ENV_IS_IN_REMOTE: 4374 4375 Define this if you have a remote memory space which you 4376 want to use for the local device's environment. 4377 4378 - CONFIG_ENV_ADDR: 4379 - CONFIG_ENV_SIZE: 4380 4381 These two #defines specify the address and size of the 4382 environment area within the remote memory space. The 4383 local device can get the environment from remote memory 4384 space by SRIO or PCIE links. 4385 4386BE CAREFUL! For some special cases, the local device can not use 4387"saveenv" command. For example, the local device will get the 4388environment stored in a remote NOR flash by SRIO or PCIE link, 4389but it can not erase, write this NOR flash by SRIO or PCIE interface. 4390 4391- CONFIG_ENV_IS_IN_NAND: 4392 4393 Define this if you have a NAND device which you want to use 4394 for the environment. 4395 4396 - CONFIG_ENV_OFFSET: 4397 - CONFIG_ENV_SIZE: 4398 4399 These two #defines specify the offset and size of the environment 4400 area within the first NAND device. CONFIG_ENV_OFFSET must be 4401 aligned to an erase block boundary. 4402 4403 - CONFIG_ENV_OFFSET_REDUND (optional): 4404 4405 This setting describes a second storage area of CONFIG_ENV_SIZE 4406 size used to hold a redundant copy of the environment data, so 4407 that there is a valid backup copy in case there is a power failure 4408 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be 4409 aligned to an erase block boundary. 4410 4411 - CONFIG_ENV_RANGE (optional): 4412 4413 Specifies the length of the region in which the environment 4414 can be written. This should be a multiple of the NAND device's 4415 block size. Specifying a range with more erase blocks than 4416 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 4417 the range to be avoided. 4418 4419 - CONFIG_ENV_OFFSET_OOB (optional): 4420 4421 Enables support for dynamically retrieving the offset of the 4422 environment from block zero's out-of-band data. The 4423 "nand env.oob" command can be used to record this offset. 4424 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 4425 using CONFIG_ENV_OFFSET_OOB. 4426 4427- CONFIG_NAND_ENV_DST 4428 4429 Defines address in RAM to which the nand_spl code should copy the 4430 environment. If redundant environment is used, it will be copied to 4431 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 4432 4433- CONFIG_ENV_IS_IN_UBI: 4434 4435 Define this if you have an UBI volume that you want to use for the 4436 environment. This has the benefit of wear-leveling the environment 4437 accesses, which is important on NAND. 4438 4439 - CONFIG_ENV_UBI_PART: 4440 4441 Define this to a string that is the mtd partition containing the UBI. 4442 4443 - CONFIG_ENV_UBI_VOLUME: 4444 4445 Define this to the name of the volume that you want to store the 4446 environment in. 4447 4448 - CONFIG_ENV_UBI_VOLUME_REDUND: 4449 4450 Define this to the name of another volume to store a second copy of 4451 the environment in. This will enable redundant environments in UBI. 4452 It is assumed that both volumes are in the same MTD partition. 4453 4454 - CONFIG_UBI_SILENCE_MSG 4455 - CONFIG_UBIFS_SILENCE_MSG 4456 4457 You will probably want to define these to avoid a really noisy system 4458 when storing the env in UBI. 4459 4460- CONFIG_ENV_IS_IN_FAT: 4461 Define this if you want to use the FAT file system for the environment. 4462 4463 - FAT_ENV_INTERFACE: 4464 4465 Define this to a string that is the name of the block device. 4466 4467 - FAT_ENV_DEV_AND_PART: 4468 4469 Define this to a string to specify the partition of the device. It can 4470 be as following: 4471 4472 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 4473 - "D:P": device D partition P. Error occurs if device D has no 4474 partition table. 4475 - "D:0": device D. 4476 - "D" or "D:": device D partition 1 if device D has partition 4477 table, or the whole device D if has no partition 4478 table. 4479 - "D:auto": first partition in device D with bootable flag set. 4480 If none, first valid partition in device D. If no 4481 partition table then means device D. 4482 4483 - FAT_ENV_FILE: 4484 4485 It's a string of the FAT file name. This file use to store the 4486 environment. 4487 4488 - CONFIG_FAT_WRITE: 4489 This should be defined. Otherwise it cannot save the environment file. 4490 4491- CONFIG_ENV_IS_IN_MMC: 4492 4493 Define this if you have an MMC device which you want to use for the 4494 environment. 4495 4496 - CONFIG_SYS_MMC_ENV_DEV: 4497 4498 Specifies which MMC device the environment is stored in. 4499 4500 - CONFIG_SYS_MMC_ENV_PART (optional): 4501 4502 Specifies which MMC partition the environment is stored in. If not 4503 set, defaults to partition 0, the user area. Common values might be 4504 1 (first MMC boot partition), 2 (second MMC boot partition). 4505 4506 - CONFIG_ENV_OFFSET: 4507 - CONFIG_ENV_SIZE: 4508 4509 These two #defines specify the offset and size of the environment 4510 area within the specified MMC device. 4511 4512 If offset is positive (the usual case), it is treated as relative to 4513 the start of the MMC partition. If offset is negative, it is treated 4514 as relative to the end of the MMC partition. This can be useful if 4515 your board may be fitted with different MMC devices, which have 4516 different sizes for the MMC partitions, and you always want the 4517 environment placed at the very end of the partition, to leave the 4518 maximum possible space before it, to store other data. 4519 4520 These two values are in units of bytes, but must be aligned to an 4521 MMC sector boundary. 4522 4523 - CONFIG_ENV_OFFSET_REDUND (optional): 4524 4525 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 4526 hold a redundant copy of the environment data. This provides a 4527 valid backup copy in case the other copy is corrupted, e.g. due 4528 to a power failure during a "saveenv" operation. 4529 4530 This value may also be positive or negative; this is handled in the 4531 same way as CONFIG_ENV_OFFSET. 4532 4533 This value is also in units of bytes, but must also be aligned to 4534 an MMC sector boundary. 4535 4536 - CONFIG_ENV_SIZE_REDUND (optional): 4537 4538 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 4539 set. If this value is set, it must be set to the same value as 4540 CONFIG_ENV_SIZE. 4541 4542- CONFIG_SYS_SPI_INIT_OFFSET 4543 4544 Defines offset to the initial SPI buffer area in DPRAM. The 4545 area is used at an early stage (ROM part) if the environment 4546 is configured to reside in the SPI EEPROM: We need a 520 byte 4547 scratch DPRAM area. It is used between the two initialization 4548 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems 4549 to be a good choice since it makes it far enough from the 4550 start of the data area as well as from the stack pointer. 4551 4552Please note that the environment is read-only until the monitor 4553has been relocated to RAM and a RAM copy of the environment has been 4554created; also, when using EEPROM you will have to use getenv_f() 4555until then to read environment variables. 4556 4557The environment is protected by a CRC32 checksum. Before the monitor 4558is relocated into RAM, as a result of a bad CRC you will be working 4559with the compiled-in default environment - *silently*!!! [This is 4560necessary, because the first environment variable we need is the 4561"baudrate" setting for the console - if we have a bad CRC, we don't 4562have any device yet where we could complain.] 4563 4564Note: once the monitor has been relocated, then it will complain if 4565the default environment is used; a new CRC is computed as soon as you 4566use the "saveenv" command to store a valid environment. 4567 4568- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 4569 Echo the inverted Ethernet link state to the fault LED. 4570 4571 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 4572 also needs to be defined. 4573 4574- CONFIG_SYS_FAULT_MII_ADDR: 4575 MII address of the PHY to check for the Ethernet link state. 4576 4577- CONFIG_NS16550_MIN_FUNCTIONS: 4578 Define this if you desire to only have use of the NS16550_init 4579 and NS16550_putc functions for the serial driver located at 4580 drivers/serial/ns16550.c. This option is useful for saving 4581 space for already greatly restricted images, including but not 4582 limited to NAND_SPL configurations. 4583 4584- CONFIG_DISPLAY_BOARDINFO 4585 Display information about the board that U-Boot is running on 4586 when U-Boot starts up. The board function checkboard() is called 4587 to do this. 4588 4589- CONFIG_DISPLAY_BOARDINFO_LATE 4590 Similar to the previous option, but display this information 4591 later, once stdio is running and output goes to the LCD, if 4592 present. 4593 4594- CONFIG_BOARD_SIZE_LIMIT: 4595 Maximum size of the U-Boot image. When defined, the 4596 build system checks that the actual size does not 4597 exceed it. 4598 4599Low Level (hardware related) configuration options: 4600--------------------------------------------------- 4601 4602- CONFIG_SYS_CACHELINE_SIZE: 4603 Cache Line Size of the CPU. 4604 4605- CONFIG_SYS_DEFAULT_IMMR: 4606 Default address of the IMMR after system reset. 4607 4608 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU, 4609 and RPXsuper) to be able to adjust the position of 4610 the IMMR register after a reset. 4611 4612- CONFIG_SYS_CCSRBAR_DEFAULT: 4613 Default (power-on reset) physical address of CCSR on Freescale 4614 PowerPC SOCs. 4615 4616- CONFIG_SYS_CCSRBAR: 4617 Virtual address of CCSR. On a 32-bit build, this is typically 4618 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 4619 4620 CONFIG_SYS_DEFAULT_IMMR must also be set to this value, 4621 for cross-platform code that uses that macro instead. 4622 4623- CONFIG_SYS_CCSRBAR_PHYS: 4624 Physical address of CCSR. CCSR can be relocated to a new 4625 physical address, if desired. In this case, this macro should 4626 be set to that address. Otherwise, it should be set to the 4627 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 4628 is typically relocated on 36-bit builds. It is recommended 4629 that this macro be defined via the _HIGH and _LOW macros: 4630 4631 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 4632 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 4633 4634- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 4635 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 4636 either 0 (32-bit build) or 0xF (36-bit build). This macro is 4637 used in assembly code, so it must not contain typecasts or 4638 integer size suffixes (e.g. "ULL"). 4639 4640- CONFIG_SYS_CCSRBAR_PHYS_LOW: 4641 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 4642 used in assembly code, so it must not contain typecasts or 4643 integer size suffixes (e.g. "ULL"). 4644 4645- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 4646 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 4647 forced to a value that ensures that CCSR is not relocated. 4648 4649- Floppy Disk Support: 4650 CONFIG_SYS_FDC_DRIVE_NUMBER 4651 4652 the default drive number (default value 0) 4653 4654 CONFIG_SYS_ISA_IO_STRIDE 4655 4656 defines the spacing between FDC chipset registers 4657 (default value 1) 4658 4659 CONFIG_SYS_ISA_IO_OFFSET 4660 4661 defines the offset of register from address. It 4662 depends on which part of the data bus is connected to 4663 the FDC chipset. (default value 0) 4664 4665 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 4666 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 4667 default value. 4668 4669 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 4670 fdc_hw_init() is called at the beginning of the FDC 4671 setup. fdc_hw_init() must be provided by the board 4672 source code. It is used to make hardware-dependent 4673 initializations. 4674 4675- CONFIG_IDE_AHB: 4676 Most IDE controllers were designed to be connected with PCI 4677 interface. Only few of them were designed for AHB interface. 4678 When software is doing ATA command and data transfer to 4679 IDE devices through IDE-AHB controller, some additional 4680 registers accessing to these kind of IDE-AHB controller 4681 is required. 4682 4683- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 4684 DO NOT CHANGE unless you know exactly what you're 4685 doing! (11-4) [MPC8xx/82xx systems only] 4686 4687- CONFIG_SYS_INIT_RAM_ADDR: 4688 4689 Start address of memory area that can be used for 4690 initial data and stack; please note that this must be 4691 writable memory that is working WITHOUT special 4692 initialization, i. e. you CANNOT use normal RAM which 4693 will become available only after programming the 4694 memory controller and running certain initialization 4695 sequences. 4696 4697 U-Boot uses the following memory types: 4698 - MPC8xx and MPC8260: IMMR (internal memory of the CPU) 4699 - MPC824X: data cache 4700 - PPC4xx: data cache 4701 4702- CONFIG_SYS_GBL_DATA_OFFSET: 4703 4704 Offset of the initial data structure in the memory 4705 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 4706 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 4707 data is located at the end of the available space 4708 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 4709 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just 4710 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 4711 CONFIG_SYS_GBL_DATA_OFFSET) downward. 4712 4713 Note: 4714 On the MPC824X (or other systems that use the data 4715 cache for initial memory) the address chosen for 4716 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 4717 point to an otherwise UNUSED address space between 4718 the top of RAM and the start of the PCI space. 4719 4720- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 4721 4722- CONFIG_SYS_SYPCR: System Protection Control (11-9) 4723 4724- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 4725 4726- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 4727 4728- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4729 4730- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4731 4732- CONFIG_SYS_OR_TIMING_SDRAM: 4733 SDRAM timing 4734 4735- CONFIG_SYS_MAMR_PTA: 4736 periodic timer for refresh 4737 4738- CONFIG_SYS_DER: Debug Event Register (37-47) 4739 4740- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4741 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4742 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4743 CONFIG_SYS_BR1_PRELIM: 4744 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4745 4746- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4747 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4748 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4749 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4750 4751- CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K, 4752 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL: 4753 Machine Mode Register and Memory Periodic Timer 4754 Prescaler definitions (SDRAM timing) 4755 4756- CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]: 4757 enable I2C microcode relocation patch (MPC8xx); 4758 define relocation offset in DPRAM [DSP2] 4759 4760- CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]: 4761 enable SMC microcode relocation patch (MPC8xx); 4762 define relocation offset in DPRAM [SMC1] 4763 4764- CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]: 4765 enable SPI microcode relocation patch (MPC8xx); 4766 define relocation offset in DPRAM [SCC4] 4767 4768- CONFIG_SYS_USE_OSCCLK: 4769 Use OSCM clock mode on MBX8xx board. Be careful, 4770 wrong setting might damage your board. Read 4771 doc/README.MBX before setting this variable! 4772 4773- CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only) 4774 Offset of the bootmode word in DPRAM used by post 4775 (Power On Self Tests). This definition overrides 4776 #define'd default value in commproc.h resp. 4777 cpm_8260.h. 4778 4779- CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB, 4780 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL, 4781 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS, 4782 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB, 4783 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START, 4784 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL, 4785 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE, 4786 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only) 4787 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set. 4788 4789- CONFIG_PCI_DISABLE_PCIE: 4790 Disable PCI-Express on systems where it is supported but not 4791 required. 4792 4793- CONFIG_PCI_ENUM_ONLY 4794 Only scan through and get the devices on the buses. 4795 Don't do any setup work, presumably because someone or 4796 something has already done it, and we don't need to do it 4797 a second time. Useful for platforms that are pre-booted 4798 by coreboot or similar. 4799 4800- CONFIG_PCI_INDIRECT_BRIDGE: 4801 Enable support for indirect PCI bridges. 4802 4803- CONFIG_SYS_SRIO: 4804 Chip has SRIO or not 4805 4806- CONFIG_SRIO1: 4807 Board has SRIO 1 port available 4808 4809- CONFIG_SRIO2: 4810 Board has SRIO 2 port available 4811 4812- CONFIG_SRIO_PCIE_BOOT_MASTER 4813 Board can support master function for Boot from SRIO and PCIE 4814 4815- CONFIG_SYS_SRIOn_MEM_VIRT: 4816 Virtual Address of SRIO port 'n' memory region 4817 4818- CONFIG_SYS_SRIOn_MEM_PHYS: 4819 Physical Address of SRIO port 'n' memory region 4820 4821- CONFIG_SYS_SRIOn_MEM_SIZE: 4822 Size of SRIO port 'n' memory region 4823 4824- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4825 Defined to tell the NAND controller that the NAND chip is using 4826 a 16 bit bus. 4827 Not all NAND drivers use this symbol. 4828 Example of drivers that use it: 4829 - drivers/mtd/nand/ndfc.c 4830 - drivers/mtd/nand/mxc_nand.c 4831 4832- CONFIG_SYS_NDFC_EBC0_CFG 4833 Sets the EBC0_CFG register for the NDFC. If not defined 4834 a default value will be used. 4835 4836- CONFIG_SPD_EEPROM 4837 Get DDR timing information from an I2C EEPROM. Common 4838 with pluggable memory modules such as SODIMMs 4839 4840 SPD_EEPROM_ADDRESS 4841 I2C address of the SPD EEPROM 4842 4843- CONFIG_SYS_SPD_BUS_NUM 4844 If SPD EEPROM is on an I2C bus other than the first 4845 one, specify here. Note that the value must resolve 4846 to something your driver can deal with. 4847 4848- CONFIG_SYS_DDR_RAW_TIMING 4849 Get DDR timing information from other than SPD. Common with 4850 soldered DDR chips onboard without SPD. DDR raw timing 4851 parameters are extracted from datasheet and hard-coded into 4852 header files or board specific files. 4853 4854- CONFIG_FSL_DDR_INTERACTIVE 4855 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4856 4857- CONFIG_FSL_DDR_SYNC_REFRESH 4858 Enable sync of refresh for multiple controllers. 4859 4860- CONFIG_FSL_DDR_BIST 4861 Enable built-in memory test for Freescale DDR controllers. 4862 4863- CONFIG_SYS_83XX_DDR_USES_CS0 4864 Only for 83xx systems. If specified, then DDR should 4865 be configured using CS0 and CS1 instead of CS2 and CS3. 4866 4867- CONFIG_ETHER_ON_FEC[12] 4868 Define to enable FEC[12] on a 8xx series processor. 4869 4870- CONFIG_FEC[12]_PHY 4871 Define to the hardcoded PHY address which corresponds 4872 to the given FEC; i. e. 4873 #define CONFIG_FEC1_PHY 4 4874 means that the PHY with address 4 is connected to FEC1 4875 4876 When set to -1, means to probe for first available. 4877 4878- CONFIG_FEC[12]_PHY_NORXERR 4879 The PHY does not have a RXERR line (RMII only). 4880 (so program the FEC to ignore it). 4881 4882- CONFIG_RMII 4883 Enable RMII mode for all FECs. 4884 Note that this is a global option, we can't 4885 have one FEC in standard MII mode and another in RMII mode. 4886 4887- CONFIG_CRC32_VERIFY 4888 Add a verify option to the crc32 command. 4889 The syntax is: 4890 4891 => crc32 -v <address> <count> <crc32> 4892 4893 Where address/count indicate a memory area 4894 and crc32 is the correct crc32 which the 4895 area should have. 4896 4897- CONFIG_LOOPW 4898 Add the "loopw" memory command. This only takes effect if 4899 the memory commands are activated globally (CONFIG_CMD_MEM). 4900 4901- CONFIG_MX_CYCLIC 4902 Add the "mdc" and "mwc" memory commands. These are cyclic 4903 "md/mw" commands. 4904 Examples: 4905 4906 => mdc.b 10 4 500 4907 This command will print 4 bytes (10,11,12,13) each 500 ms. 4908 4909 => mwc.l 100 12345678 10 4910 This command will write 12345678 to address 100 all 10 ms. 4911 4912 This only takes effect if the memory commands are activated 4913 globally (CONFIG_CMD_MEM). 4914 4915- CONFIG_SKIP_LOWLEVEL_INIT 4916 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4917 low level initializations (like setting up the memory 4918 controller) are omitted and/or U-Boot does not 4919 relocate itself into RAM. 4920 4921 Normally this variable MUST NOT be defined. The only 4922 exception is when U-Boot is loaded (to RAM) by some 4923 other boot loader or by a debugger which performs 4924 these initializations itself. 4925 4926- CONFIG_SPL_BUILD 4927 Modifies the behaviour of start.S when compiling a loader 4928 that is executed before the actual U-Boot. E.g. when 4929 compiling a NAND SPL. 4930 4931- CONFIG_TPL_BUILD 4932 Modifies the behaviour of start.S when compiling a loader 4933 that is executed after the SPL and before the actual U-Boot. 4934 It is loaded by the SPL. 4935 4936- CONFIG_SYS_MPC85XX_NO_RESETVEC 4937 Only for 85xx systems. If this variable is specified, the section 4938 .resetvec is not kept and the section .bootpg is placed in the 4939 previous 4k of the .text section. 4940 4941- CONFIG_ARCH_MAP_SYSMEM 4942 Generally U-Boot (and in particular the md command) uses 4943 effective address. It is therefore not necessary to regard 4944 U-Boot address as virtual addresses that need to be translated 4945 to physical addresses. However, sandbox requires this, since 4946 it maintains its own little RAM buffer which contains all 4947 addressable memory. This option causes some memory accesses 4948 to be mapped through map_sysmem() / unmap_sysmem(). 4949 4950- CONFIG_USE_ARCH_MEMCPY 4951 CONFIG_USE_ARCH_MEMSET 4952 If these options are used a optimized version of memcpy/memset will 4953 be used if available. These functions may be faster under some 4954 conditions but may increase the binary size. 4955 4956- CONFIG_X86_RESET_VECTOR 4957 If defined, the x86 reset vector code is included. This is not 4958 needed when U-Boot is running from Coreboot. 4959 4960- CONFIG_SYS_MPUCLK 4961 Defines the MPU clock speed (in MHz). 4962 4963 NOTE : currently only supported on AM335x platforms. 4964 4965- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4966 Enables the RTC32K OSC on AM33xx based plattforms 4967 4968- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4969 Option to disable subpage write in NAND driver 4970 driver that uses this: 4971 drivers/mtd/nand/davinci_nand.c 4972 4973Freescale QE/FMAN Firmware Support: 4974----------------------------------- 4975 4976The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4977loading of "firmware", which is encoded in the QE firmware binary format. 4978This firmware often needs to be loaded during U-Boot booting, so macros 4979are used to identify the storage device (NOR flash, SPI, etc) and the address 4980within that device. 4981 4982- CONFIG_SYS_FMAN_FW_ADDR 4983 The address in the storage device where the FMAN microcode is located. The 4984 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4985 is also specified. 4986 4987- CONFIG_SYS_QE_FW_ADDR 4988 The address in the storage device where the QE microcode is located. The 4989 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4990 is also specified. 4991 4992- CONFIG_SYS_QE_FMAN_FW_LENGTH 4993 The maximum possible size of the firmware. The firmware binary format 4994 has a field that specifies the actual size of the firmware, but it 4995 might not be possible to read any part of the firmware unless some 4996 local storage is allocated to hold the entire firmware first. 4997 4998- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4999 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 5000 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 5001 virtual address in NOR flash. 5002 5003- CONFIG_SYS_QE_FMAN_FW_IN_NAND 5004 Specifies that QE/FMAN firmware is located in NAND flash. 5005 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 5006 5007- CONFIG_SYS_QE_FMAN_FW_IN_MMC 5008 Specifies that QE/FMAN firmware is located on the primary SD/MMC 5009 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 5010 5011- CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH 5012 Specifies that QE/FMAN firmware is located on the primary SPI 5013 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 5014 5015- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 5016 Specifies that QE/FMAN firmware is located in the remote (master) 5017 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 5018 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 5019 window->master inbound window->master LAW->the ucode address in 5020 master's memory space. 5021 5022Freescale Layerscape Management Complex Firmware Support: 5023--------------------------------------------------------- 5024The Freescale Layerscape Management Complex (MC) supports the loading of 5025"firmware". 5026This firmware often needs to be loaded during U-Boot booting, so macros 5027are used to identify the storage device (NOR flash, SPI, etc) and the address 5028within that device. 5029 5030- CONFIG_FSL_MC_ENET 5031 Enable the MC driver for Layerscape SoCs. 5032 5033- CONFIG_SYS_LS_MC_FW_ADDR 5034 The address in the storage device where the firmware is located. The 5035 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro 5036 is also specified. 5037 5038- CONFIG_SYS_LS_MC_FW_LENGTH 5039 The maximum possible size of the firmware. The firmware binary format 5040 has a field that specifies the actual size of the firmware, but it 5041 might not be possible to read any part of the firmware unless some 5042 local storage is allocated to hold the entire firmware first. 5043 5044- CONFIG_SYS_LS_MC_FW_IN_NOR 5045 Specifies that MC firmware is located in NOR flash, mapped as 5046 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the 5047 virtual address in NOR flash. 5048 5049Freescale Layerscape Debug Server Support: 5050------------------------------------------- 5051The Freescale Layerscape Debug Server Support supports the loading of 5052"Debug Server firmware" and triggering SP boot-rom. 5053This firmware often needs to be loaded during U-Boot booting. 5054 5055- CONFIG_FSL_DEBUG_SERVER 5056 Enable the Debug Server for Layerscape SoCs. 5057 5058- CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE 5059 Define minimum DDR size required for debug server image 5060 5061- CONFIG_SYS_MEM_TOP_HIDE_MIN 5062 Define minimum DDR size to be hided from top of the DDR memory 5063 5064Reproducible builds 5065------------------- 5066 5067In order to achieve reproducible builds, timestamps used in the U-Boot build 5068process have to be set to a fixed value. 5069 5070This is done using the SOURCE_DATE_EPOCH environment variable. 5071SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 5072option for U-Boot or an environment variable in U-Boot. 5073 5074SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 5075 5076Building the Software: 5077====================== 5078 5079Building U-Boot has been tested in several native build environments 5080and in many different cross environments. Of course we cannot support 5081all possibly existing versions of cross development tools in all 5082(potentially obsolete) versions. In case of tool chain problems we 5083recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 5084which is extensively used to build and test U-Boot. 5085 5086If you are not using a native environment, it is assumed that you 5087have GNU cross compiling tools available in your path. In this case, 5088you must set the environment variable CROSS_COMPILE in your shell. 5089Note that no changes to the Makefile or any other source files are 5090necessary. For example using the ELDK on a 4xx CPU, please enter: 5091 5092 $ CROSS_COMPILE=ppc_4xx- 5093 $ export CROSS_COMPILE 5094 5095Note: If you wish to generate Windows versions of the utilities in 5096 the tools directory you can use the MinGW toolchain 5097 (http://www.mingw.org). Set your HOST tools to the MinGW 5098 toolchain and execute 'make tools'. For example: 5099 5100 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 5101 5102 Binaries such as tools/mkimage.exe will be created which can 5103 be executed on computers running Windows. 5104 5105U-Boot is intended to be simple to build. After installing the 5106sources you must configure U-Boot for one specific board type. This 5107is done by typing: 5108 5109 make NAME_defconfig 5110 5111where "NAME_defconfig" is the name of one of the existing configu- 5112rations; see boards.cfg for supported names. 5113 5114Note: for some board special configuration names may exist; check if 5115 additional information is available from the board vendor; for 5116 instance, the TQM823L systems are available without (standard) 5117 or with LCD support. You can select such additional "features" 5118 when choosing the configuration, i. e. 5119 5120 make TQM823L_defconfig 5121 - will configure for a plain TQM823L, i. e. no LCD support 5122 5123 make TQM823L_LCD_defconfig 5124 - will configure for a TQM823L with U-Boot console on LCD 5125 5126 etc. 5127 5128 5129Finally, type "make all", and you should get some working U-Boot 5130images ready for download to / installation on your system: 5131 5132- "u-boot.bin" is a raw binary image 5133- "u-boot" is an image in ELF binary format 5134- "u-boot.srec" is in Motorola S-Record format 5135 5136By default the build is performed locally and the objects are saved 5137in the source directory. One of the two methods can be used to change 5138this behavior and build U-Boot to some external directory: 5139 51401. Add O= to the make command line invocations: 5141 5142 make O=/tmp/build distclean 5143 make O=/tmp/build NAME_defconfig 5144 make O=/tmp/build all 5145 51462. Set environment variable KBUILD_OUTPUT to point to the desired location: 5147 5148 export KBUILD_OUTPUT=/tmp/build 5149 make distclean 5150 make NAME_defconfig 5151 make all 5152 5153Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 5154variable. 5155 5156 5157Please be aware that the Makefiles assume you are using GNU make, so 5158for instance on NetBSD you might need to use "gmake" instead of 5159native "make". 5160 5161 5162If the system board that you have is not listed, then you will need 5163to port U-Boot to your hardware platform. To do this, follow these 5164steps: 5165 51661. Add a new configuration option for your board to the toplevel 5167 "boards.cfg" file, using the existing entries as examples. 5168 Follow the instructions there to keep the boards in order. 51692. Create a new directory to hold your board specific code. Add any 5170 files you need. In your board directory, you will need at least 5171 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds". 51723. Create a new configuration file "include/configs/<board>.h" for 5173 your board 51743. If you're porting U-Boot to a new CPU, then also create a new 5175 directory to hold your CPU specific code. Add any files you need. 51764. Run "make <board>_defconfig" with your new name. 51775. Type "make", and you should get a working "u-boot.srec" file 5178 to be installed on your target system. 51796. Debug and solve any problems that might arise. 5180 [Of course, this last step is much harder than it sounds.] 5181 5182 5183Testing of U-Boot Modifications, Ports to New Hardware, etc.: 5184============================================================== 5185 5186If you have modified U-Boot sources (for instance added a new board 5187or support for new devices, a new CPU, etc.) you are expected to 5188provide feedback to the other developers. The feedback normally takes 5189the form of a "patch", i. e. a context diff against a certain (latest 5190official or latest in the git repository) version of U-Boot sources. 5191 5192But before you submit such a patch, please verify that your modifi- 5193cation did not break existing code. At least make sure that *ALL* of 5194the supported boards compile WITHOUT ANY compiler warnings. To do so, 5195just run the "MAKEALL" script, which will configure and build U-Boot 5196for ALL supported system. Be warned, this will take a while. You can 5197select which (cross) compiler to use by passing a `CROSS_COMPILE' 5198environment variable to the script, i. e. to use the ELDK cross tools 5199you can type 5200 5201 CROSS_COMPILE=ppc_8xx- MAKEALL 5202 5203or to build on a native PowerPC system you can type 5204 5205 CROSS_COMPILE=' ' MAKEALL 5206 5207When using the MAKEALL script, the default behaviour is to build 5208U-Boot in the source directory. This location can be changed by 5209setting the BUILD_DIR environment variable. Also, for each target 5210built, the MAKEALL script saves two log files (<target>.ERR and 5211<target>.MAKEALL) in the <source dir>/LOG directory. This default 5212location can be changed by setting the MAKEALL_LOGDIR environment 5213variable. For example: 5214 5215 export BUILD_DIR=/tmp/build 5216 export MAKEALL_LOGDIR=/tmp/log 5217 CROSS_COMPILE=ppc_8xx- MAKEALL 5218 5219With the above settings build objects are saved in the /tmp/build, 5220log files are saved in the /tmp/log and the source tree remains clean 5221during the whole build process. 5222 5223 5224See also "U-Boot Porting Guide" below. 5225 5226 5227Monitor Commands - Overview: 5228============================ 5229 5230go - start application at address 'addr' 5231run - run commands in an environment variable 5232bootm - boot application image from memory 5233bootp - boot image via network using BootP/TFTP protocol 5234bootz - boot zImage from memory 5235tftpboot- boot image via network using TFTP protocol 5236 and env variables "ipaddr" and "serverip" 5237 (and eventually "gatewayip") 5238tftpput - upload a file via network using TFTP protocol 5239rarpboot- boot image via network using RARP/TFTP protocol 5240diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 5241loads - load S-Record file over serial line 5242loadb - load binary file over serial line (kermit mode) 5243md - memory display 5244mm - memory modify (auto-incrementing) 5245nm - memory modify (constant address) 5246mw - memory write (fill) 5247cp - memory copy 5248cmp - memory compare 5249crc32 - checksum calculation 5250i2c - I2C sub-system 5251sspi - SPI utility commands 5252base - print or set address offset 5253printenv- print environment variables 5254setenv - set environment variables 5255saveenv - save environment variables to persistent storage 5256protect - enable or disable FLASH write protection 5257erase - erase FLASH memory 5258flinfo - print FLASH memory information 5259nand - NAND memory operations (see doc/README.nand) 5260bdinfo - print Board Info structure 5261iminfo - print header information for application image 5262coninfo - print console devices and informations 5263ide - IDE sub-system 5264loop - infinite loop on address range 5265loopw - infinite write loop on address range 5266mtest - simple RAM test 5267icache - enable or disable instruction cache 5268dcache - enable or disable data cache 5269reset - Perform RESET of the CPU 5270echo - echo args to console 5271version - print monitor version 5272help - print online help 5273? - alias for 'help' 5274 5275 5276Monitor Commands - Detailed Description: 5277======================================== 5278 5279TODO. 5280 5281For now: just type "help <command>". 5282 5283 5284Environment Variables: 5285====================== 5286 5287U-Boot supports user configuration using Environment Variables which 5288can be made persistent by saving to Flash memory. 5289 5290Environment Variables are set using "setenv", printed using 5291"printenv", and saved to Flash using "saveenv". Using "setenv" 5292without a value can be used to delete a variable from the 5293environment. As long as you don't save the environment you are 5294working with an in-memory copy. In case the Flash area containing the 5295environment is erased by accident, a default environment is provided. 5296 5297Some configuration options can be set using Environment Variables. 5298 5299List of environment variables (most likely not complete): 5300 5301 baudrate - see CONFIG_BAUDRATE 5302 5303 bootdelay - see CONFIG_BOOTDELAY 5304 5305 bootcmd - see CONFIG_BOOTCOMMAND 5306 5307 bootargs - Boot arguments when booting an RTOS image 5308 5309 bootfile - Name of the image to load with TFTP 5310 5311 bootm_low - Memory range available for image processing in the bootm 5312 command can be restricted. This variable is given as 5313 a hexadecimal number and defines lowest address allowed 5314 for use by the bootm command. See also "bootm_size" 5315 environment variable. Address defined by "bootm_low" is 5316 also the base of the initial memory mapping for the Linux 5317 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 5318 bootm_mapsize. 5319 5320 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 5321 This variable is given as a hexadecimal number and it 5322 defines the size of the memory region starting at base 5323 address bootm_low that is accessible by the Linux kernel 5324 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 5325 as the default value if it is defined, and bootm_size is 5326 used otherwise. 5327 5328 bootm_size - Memory range available for image processing in the bootm 5329 command can be restricted. This variable is given as 5330 a hexadecimal number and defines the size of the region 5331 allowed for use by the bootm command. See also "bootm_low" 5332 environment variable. 5333 5334 updatefile - Location of the software update file on a TFTP server, used 5335 by the automatic software update feature. Please refer to 5336 documentation in doc/README.update for more details. 5337 5338 autoload - if set to "no" (any string beginning with 'n'), 5339 "bootp" will just load perform a lookup of the 5340 configuration from the BOOTP server, but not try to 5341 load any image using TFTP 5342 5343 autostart - if set to "yes", an image loaded using the "bootp", 5344 "rarpboot", "tftpboot" or "diskboot" commands will 5345 be automatically started (by internally calling 5346 "bootm") 5347 5348 If set to "no", a standalone image passed to the 5349 "bootm" command will be copied to the load address 5350 (and eventually uncompressed), but NOT be started. 5351 This can be used to load and uncompress arbitrary 5352 data. 5353 5354 fdt_high - if set this restricts the maximum address that the 5355 flattened device tree will be copied into upon boot. 5356 For example, if you have a system with 1 GB memory 5357 at physical address 0x10000000, while Linux kernel 5358 only recognizes the first 704 MB as low memory, you 5359 may need to set fdt_high as 0x3C000000 to have the 5360 device tree blob be copied to the maximum address 5361 of the 704 MB low memory, so that Linux kernel can 5362 access it during the boot procedure. 5363 5364 If this is set to the special value 0xFFFFFFFF then 5365 the fdt will not be copied at all on boot. For this 5366 to work it must reside in writable memory, have 5367 sufficient padding on the end of it for u-boot to 5368 add the information it needs into it, and the memory 5369 must be accessible by the kernel. 5370 5371 fdtcontroladdr- if set this is the address of the control flattened 5372 device tree used by U-Boot when CONFIG_OF_CONTROL is 5373 defined. 5374 5375 i2cfast - (PPC405GP|PPC405EP only) 5376 if set to 'y' configures Linux I2C driver for fast 5377 mode (400kHZ). This environment variable is used in 5378 initialization code. So, for changes to be effective 5379 it must be saved and board must be reset. 5380 5381 initrd_high - restrict positioning of initrd images: 5382 If this variable is not set, initrd images will be 5383 copied to the highest possible address in RAM; this 5384 is usually what you want since it allows for 5385 maximum initrd size. If for some reason you want to 5386 make sure that the initrd image is loaded below the 5387 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 5388 variable to a value of "no" or "off" or "0". 5389 Alternatively, you can set it to a maximum upper 5390 address to use (U-Boot will still check that it 5391 does not overwrite the U-Boot stack and data). 5392 5393 For instance, when you have a system with 16 MB 5394 RAM, and want to reserve 4 MB from use by Linux, 5395 you can do this by adding "mem=12M" to the value of 5396 the "bootargs" variable. However, now you must make 5397 sure that the initrd image is placed in the first 5398 12 MB as well - this can be done with 5399 5400 setenv initrd_high 00c00000 5401 5402 If you set initrd_high to 0xFFFFFFFF, this is an 5403 indication to U-Boot that all addresses are legal 5404 for the Linux kernel, including addresses in flash 5405 memory. In this case U-Boot will NOT COPY the 5406 ramdisk at all. This may be useful to reduce the 5407 boot time on your system, but requires that this 5408 feature is supported by your Linux kernel. 5409 5410 ipaddr - IP address; needed for tftpboot command 5411 5412 loadaddr - Default load address for commands like "bootp", 5413 "rarpboot", "tftpboot", "loadb" or "diskboot" 5414 5415 loads_echo - see CONFIG_LOADS_ECHO 5416 5417 serverip - TFTP server IP address; needed for tftpboot command 5418 5419 bootretry - see CONFIG_BOOT_RETRY_TIME 5420 5421 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 5422 5423 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 5424 5425 ethprime - controls which interface is used first. 5426 5427 ethact - controls which interface is currently active. 5428 For example you can do the following 5429 5430 => setenv ethact FEC 5431 => ping 192.168.0.1 # traffic sent on FEC 5432 => setenv ethact SCC 5433 => ping 10.0.0.1 # traffic sent on SCC 5434 5435 ethrotate - When set to "no" U-Boot does not go through all 5436 available network interfaces. 5437 It just stays at the currently selected interface. 5438 5439 netretry - When set to "no" each network operation will 5440 either succeed or fail without retrying. 5441 When set to "once" the network operation will 5442 fail when all the available network interfaces 5443 are tried once without success. 5444 Useful on scripts which control the retry operation 5445 themselves. 5446 5447 npe_ucode - set load address for the NPE microcode 5448 5449 silent_linux - If set then Linux will be told to boot silently, by 5450 changing the console to be empty. If "yes" it will be 5451 made silent. If "no" it will not be made silent. If 5452 unset, then it will be made silent if the U-Boot console 5453 is silent. 5454 5455 tftpsrcport - If this is set, the value is used for TFTP's 5456 UDP source port. 5457 5458 tftpdstport - If this is set, the value is used for TFTP's UDP 5459 destination port instead of the Well Know Port 69. 5460 5461 tftpblocksize - Block size to use for TFTP transfers; if not set, 5462 we use the TFTP server's default block size 5463 5464 tftptimeout - Retransmission timeout for TFTP packets (in milli- 5465 seconds, minimum value is 1000 = 1 second). Defines 5466 when a packet is considered to be lost so it has to 5467 be retransmitted. The default is 5000 = 5 seconds. 5468 Lowering this value may make downloads succeed 5469 faster in networks with high packet loss rates or 5470 with unreliable TFTP servers. 5471 5472 vlan - When set to a value < 4095 the traffic over 5473 Ethernet is encapsulated/received over 802.1q 5474 VLAN tagged frames. 5475 5476The following image location variables contain the location of images 5477used in booting. The "Image" column gives the role of the image and is 5478not an environment variable name. The other columns are environment 5479variable names. "File Name" gives the name of the file on a TFTP 5480server, "RAM Address" gives the location in RAM the image will be 5481loaded to, and "Flash Location" gives the image's address in NOR 5482flash or offset in NAND flash. 5483 5484*Note* - these variables don't have to be defined for all boards, some 5485boards currently use other variables for these purposes, and some 5486boards use these variables for other purposes. 5487 5488Image File Name RAM Address Flash Location 5489----- --------- ----------- -------------- 5490u-boot u-boot u-boot_addr_r u-boot_addr 5491Linux kernel bootfile kernel_addr_r kernel_addr 5492device tree blob fdtfile fdt_addr_r fdt_addr 5493ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 5494 5495The following environment variables may be used and automatically 5496updated by the network boot commands ("bootp" and "rarpboot"), 5497depending the information provided by your boot server: 5498 5499 bootfile - see above 5500 dnsip - IP address of your Domain Name Server 5501 dnsip2 - IP address of your secondary Domain Name Server 5502 gatewayip - IP address of the Gateway (Router) to use 5503 hostname - Target hostname 5504 ipaddr - see above 5505 netmask - Subnet Mask 5506 rootpath - Pathname of the root filesystem on the NFS server 5507 serverip - see above 5508 5509 5510There are two special Environment Variables: 5511 5512 serial# - contains hardware identification information such 5513 as type string and/or serial number 5514 ethaddr - Ethernet address 5515 5516These variables can be set only once (usually during manufacturing of 5517the board). U-Boot refuses to delete or overwrite these variables 5518once they have been set once. 5519 5520 5521Further special Environment Variables: 5522 5523 ver - Contains the U-Boot version string as printed 5524 with the "version" command. This variable is 5525 readonly (see CONFIG_VERSION_VARIABLE). 5526 5527 5528Please note that changes to some configuration parameters may take 5529only effect after the next boot (yes, that's just like Windoze :-). 5530 5531 5532Callback functions for environment variables: 5533--------------------------------------------- 5534 5535For some environment variables, the behavior of u-boot needs to change 5536when their values are changed. This functionality allows functions to 5537be associated with arbitrary variables. On creation, overwrite, or 5538deletion, the callback will provide the opportunity for some side 5539effect to happen or for the change to be rejected. 5540 5541The callbacks are named and associated with a function using the 5542U_BOOT_ENV_CALLBACK macro in your board or driver code. 5543 5544These callbacks are associated with variables in one of two ways. The 5545static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 5546in the board configuration to a string that defines a list of 5547associations. The list must be in the following format: 5548 5549 entry = variable_name[:callback_name] 5550 list = entry[,list] 5551 5552If the callback name is not specified, then the callback is deleted. 5553Spaces are also allowed anywhere in the list. 5554 5555Callbacks can also be associated by defining the ".callbacks" variable 5556with the same list format above. Any association in ".callbacks" will 5557override any association in the static list. You can define 5558CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 5559".callbacks" environment variable in the default or embedded environment. 5560 5561If CONFIG_REGEX is defined, the variable_name above is evaluated as a 5562regular expression. This allows multiple variables to be connected to 5563the same callback without explicitly listing them all out. 5564 5565 5566Command Line Parsing: 5567===================== 5568 5569There are two different command line parsers available with U-Boot: 5570the old "simple" one, and the much more powerful "hush" shell: 5571 5572Old, simple command line parser: 5573-------------------------------- 5574 5575- supports environment variables (through setenv / saveenv commands) 5576- several commands on one line, separated by ';' 5577- variable substitution using "... ${name} ..." syntax 5578- special characters ('$', ';') can be escaped by prefixing with '\', 5579 for example: 5580 setenv bootcmd bootm \${address} 5581- You can also escape text by enclosing in single apostrophes, for example: 5582 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 5583 5584Hush shell: 5585----------- 5586 5587- similar to Bourne shell, with control structures like 5588 if...then...else...fi, for...do...done; while...do...done, 5589 until...do...done, ... 5590- supports environment ("global") variables (through setenv / saveenv 5591 commands) and local shell variables (through standard shell syntax 5592 "name=value"); only environment variables can be used with "run" 5593 command 5594 5595General rules: 5596-------------- 5597 5598(1) If a command line (or an environment variable executed by a "run" 5599 command) contains several commands separated by semicolon, and 5600 one of these commands fails, then the remaining commands will be 5601 executed anyway. 5602 5603(2) If you execute several variables with one call to run (i. e. 5604 calling run with a list of variables as arguments), any failing 5605 command will cause "run" to terminate, i. e. the remaining 5606 variables are not executed. 5607 5608Note for Redundant Ethernet Interfaces: 5609======================================= 5610 5611Some boards come with redundant Ethernet interfaces; U-Boot supports 5612such configurations and is capable of automatic selection of a 5613"working" interface when needed. MAC assignment works as follows: 5614 5615Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 5616MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 5617"eth1addr" (=>eth1), "eth2addr", ... 5618 5619If the network interface stores some valid MAC address (for instance 5620in SROM), this is used as default address if there is NO correspon- 5621ding setting in the environment; if the corresponding environment 5622variable is set, this overrides the settings in the card; that means: 5623 5624o If the SROM has a valid MAC address, and there is no address in the 5625 environment, the SROM's address is used. 5626 5627o If there is no valid address in the SROM, and a definition in the 5628 environment exists, then the value from the environment variable is 5629 used. 5630 5631o If both the SROM and the environment contain a MAC address, and 5632 both addresses are the same, this MAC address is used. 5633 5634o If both the SROM and the environment contain a MAC address, and the 5635 addresses differ, the value from the environment is used and a 5636 warning is printed. 5637 5638o If neither SROM nor the environment contain a MAC address, an error 5639 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 5640 a random, locally-assigned MAC is used. 5641 5642If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 5643will be programmed into hardware as part of the initialization process. This 5644may be skipped by setting the appropriate 'ethmacskip' environment variable. 5645The naming convention is as follows: 5646"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 5647 5648Image Formats: 5649============== 5650 5651U-Boot is capable of booting (and performing other auxiliary operations on) 5652images in two formats: 5653 5654New uImage format (FIT) 5655----------------------- 5656 5657Flexible and powerful format based on Flattened Image Tree -- FIT (similar 5658to Flattened Device Tree). It allows the use of images with multiple 5659components (several kernels, ramdisks, etc.), with contents protected by 5660SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 5661 5662 5663Old uImage format 5664----------------- 5665 5666Old image format is based on binary files which can be basically anything, 5667preceded by a special header; see the definitions in include/image.h for 5668details; basically, the header defines the following image properties: 5669 5670* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 5671 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 5672 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 5673 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 5674 INTEGRITY). 5675* Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86, 5676 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 5677 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC). 5678* Compression Type (uncompressed, gzip, bzip2) 5679* Load Address 5680* Entry Point 5681* Image Name 5682* Image Timestamp 5683 5684The header is marked by a special Magic Number, and both the header 5685and the data portions of the image are secured against corruption by 5686CRC32 checksums. 5687 5688 5689Linux Support: 5690============== 5691 5692Although U-Boot should support any OS or standalone application 5693easily, the main focus has always been on Linux during the design of 5694U-Boot. 5695 5696U-Boot includes many features that so far have been part of some 5697special "boot loader" code within the Linux kernel. Also, any 5698"initrd" images to be used are no longer part of one big Linux image; 5699instead, kernel and "initrd" are separate images. This implementation 5700serves several purposes: 5701 5702- the same features can be used for other OS or standalone 5703 applications (for instance: using compressed images to reduce the 5704 Flash memory footprint) 5705 5706- it becomes much easier to port new Linux kernel versions because 5707 lots of low-level, hardware dependent stuff are done by U-Boot 5708 5709- the same Linux kernel image can now be used with different "initrd" 5710 images; of course this also means that different kernel images can 5711 be run with the same "initrd". This makes testing easier (you don't 5712 have to build a new "zImage.initrd" Linux image when you just 5713 change a file in your "initrd"). Also, a field-upgrade of the 5714 software is easier now. 5715 5716 5717Linux HOWTO: 5718============ 5719 5720Porting Linux to U-Boot based systems: 5721--------------------------------------- 5722 5723U-Boot cannot save you from doing all the necessary modifications to 5724configure the Linux device drivers for use with your target hardware 5725(no, we don't intend to provide a full virtual machine interface to 5726Linux :-). 5727 5728But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 5729 5730Just make sure your machine specific header file (for instance 5731include/asm-ppc/tqm8xx.h) includes the same definition of the Board 5732Information structure as we define in include/asm-<arch>/u-boot.h, 5733and make sure that your definition of IMAP_ADDR uses the same value 5734as your U-Boot configuration in CONFIG_SYS_IMMR. 5735 5736Note that U-Boot now has a driver model, a unified model for drivers. 5737If you are adding a new driver, plumb it into driver model. If there 5738is no uclass available, you are encouraged to create one. See 5739doc/driver-model. 5740 5741 5742Configuring the Linux kernel: 5743----------------------------- 5744 5745No specific requirements for U-Boot. Make sure you have some root 5746device (initial ramdisk, NFS) for your target system. 5747 5748 5749Building a Linux Image: 5750----------------------- 5751 5752With U-Boot, "normal" build targets like "zImage" or "bzImage" are 5753not used. If you use recent kernel source, a new build target 5754"uImage" will exist which automatically builds an image usable by 5755U-Boot. Most older kernels also have support for a "pImage" target, 5756which was introduced for our predecessor project PPCBoot and uses a 5757100% compatible format. 5758 5759Example: 5760 5761 make TQM850L_defconfig 5762 make oldconfig 5763 make dep 5764 make uImage 5765 5766The "uImage" build target uses a special tool (in 'tools/mkimage') to 5767encapsulate a compressed Linux kernel image with header information, 5768CRC32 checksum etc. for use with U-Boot. This is what we are doing: 5769 5770* build a standard "vmlinux" kernel image (in ELF binary format): 5771 5772* convert the kernel into a raw binary image: 5773 5774 ${CROSS_COMPILE}-objcopy -O binary \ 5775 -R .note -R .comment \ 5776 -S vmlinux linux.bin 5777 5778* compress the binary image: 5779 5780 gzip -9 linux.bin 5781 5782* package compressed binary image for U-Boot: 5783 5784 mkimage -A ppc -O linux -T kernel -C gzip \ 5785 -a 0 -e 0 -n "Linux Kernel Image" \ 5786 -d linux.bin.gz uImage 5787 5788 5789The "mkimage" tool can also be used to create ramdisk images for use 5790with U-Boot, either separated from the Linux kernel image, or 5791combined into one file. "mkimage" encapsulates the images with a 64 5792byte header containing information about target architecture, 5793operating system, image type, compression method, entry points, time 5794stamp, CRC32 checksums, etc. 5795 5796"mkimage" can be called in two ways: to verify existing images and 5797print the header information, or to build new images. 5798 5799In the first form (with "-l" option) mkimage lists the information 5800contained in the header of an existing U-Boot image; this includes 5801checksum verification: 5802 5803 tools/mkimage -l image 5804 -l ==> list image header information 5805 5806The second form (with "-d" option) is used to build a U-Boot image 5807from a "data file" which is used as image payload: 5808 5809 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 5810 -n name -d data_file image 5811 -A ==> set architecture to 'arch' 5812 -O ==> set operating system to 'os' 5813 -T ==> set image type to 'type' 5814 -C ==> set compression type 'comp' 5815 -a ==> set load address to 'addr' (hex) 5816 -e ==> set entry point to 'ep' (hex) 5817 -n ==> set image name to 'name' 5818 -d ==> use image data from 'datafile' 5819 5820Right now, all Linux kernels for PowerPC systems use the same load 5821address (0x00000000), but the entry point address depends on the 5822kernel version: 5823 5824- 2.2.x kernels have the entry point at 0x0000000C, 5825- 2.3.x and later kernels have the entry point at 0x00000000. 5826 5827So a typical call to build a U-Boot image would read: 5828 5829 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5830 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5831 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5832 > examples/uImage.TQM850L 5833 Image Name: 2.4.4 kernel for TQM850L 5834 Created: Wed Jul 19 02:34:59 2000 5835 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5836 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5837 Load Address: 0x00000000 5838 Entry Point: 0x00000000 5839 5840To verify the contents of the image (or check for corruption): 5841 5842 -> tools/mkimage -l examples/uImage.TQM850L 5843 Image Name: 2.4.4 kernel for TQM850L 5844 Created: Wed Jul 19 02:34:59 2000 5845 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5846 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5847 Load Address: 0x00000000 5848 Entry Point: 0x00000000 5849 5850NOTE: for embedded systems where boot time is critical you can trade 5851speed for memory and install an UNCOMPRESSED image instead: this 5852needs more space in Flash, but boots much faster since it does not 5853need to be uncompressed: 5854 5855 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5856 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5857 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5858 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5859 > examples/uImage.TQM850L-uncompressed 5860 Image Name: 2.4.4 kernel for TQM850L 5861 Created: Wed Jul 19 02:34:59 2000 5862 Image Type: PowerPC Linux Kernel Image (uncompressed) 5863 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5864 Load Address: 0x00000000 5865 Entry Point: 0x00000000 5866 5867 5868Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5869when your kernel is intended to use an initial ramdisk: 5870 5871 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5872 > -A ppc -O linux -T ramdisk -C gzip \ 5873 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5874 Image Name: Simple Ramdisk Image 5875 Created: Wed Jan 12 14:01:50 2000 5876 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5877 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5878 Load Address: 0x00000000 5879 Entry Point: 0x00000000 5880 5881The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5882option performs the converse operation of the mkimage's second form (the "-d" 5883option). Given an image built by mkimage, the dumpimage extracts a "data file" 5884from the image: 5885 5886 tools/dumpimage -i image -T type -p position data_file 5887 -i ==> extract from the 'image' a specific 'data_file' 5888 -T ==> set image type to 'type' 5889 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5890 5891 5892Installing a Linux Image: 5893------------------------- 5894 5895To downloading a U-Boot image over the serial (console) interface, 5896you must convert the image to S-Record format: 5897 5898 objcopy -I binary -O srec examples/image examples/image.srec 5899 5900The 'objcopy' does not understand the information in the U-Boot 5901image header, so the resulting S-Record file will be relative to 5902address 0x00000000. To load it to a given address, you need to 5903specify the target address as 'offset' parameter with the 'loads' 5904command. 5905 5906Example: install the image to address 0x40100000 (which on the 5907TQM8xxL is in the first Flash bank): 5908 5909 => erase 40100000 401FFFFF 5910 5911 .......... done 5912 Erased 8 sectors 5913 5914 => loads 40100000 5915 ## Ready for S-Record download ... 5916 ~>examples/image.srec 5917 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5918 ... 5919 15989 15990 15991 15992 5920 [file transfer complete] 5921 [connected] 5922 ## Start Addr = 0x00000000 5923 5924 5925You can check the success of the download using the 'iminfo' command; 5926this includes a checksum verification so you can be sure no data 5927corruption happened: 5928 5929 => imi 40100000 5930 5931 ## Checking Image at 40100000 ... 5932 Image Name: 2.2.13 for initrd on TQM850L 5933 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5934 Data Size: 335725 Bytes = 327 kB = 0 MB 5935 Load Address: 00000000 5936 Entry Point: 0000000c 5937 Verifying Checksum ... OK 5938 5939 5940Boot Linux: 5941----------- 5942 5943The "bootm" command is used to boot an application that is stored in 5944memory (RAM or Flash). In case of a Linux kernel image, the contents 5945of the "bootargs" environment variable is passed to the kernel as 5946parameters. You can check and modify this variable using the 5947"printenv" and "setenv" commands: 5948 5949 5950 => printenv bootargs 5951 bootargs=root=/dev/ram 5952 5953 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5954 5955 => printenv bootargs 5956 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5957 5958 => bootm 40020000 5959 ## Booting Linux kernel at 40020000 ... 5960 Image Name: 2.2.13 for NFS on TQM850L 5961 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5962 Data Size: 381681 Bytes = 372 kB = 0 MB 5963 Load Address: 00000000 5964 Entry Point: 0000000c 5965 Verifying Checksum ... OK 5966 Uncompressing Kernel Image ... OK 5967 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 5968 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5969 time_init: decrementer frequency = 187500000/60 5970 Calibrating delay loop... 49.77 BogoMIPS 5971 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5972 ... 5973 5974If you want to boot a Linux kernel with initial RAM disk, you pass 5975the memory addresses of both the kernel and the initrd image (PPBCOOT 5976format!) to the "bootm" command: 5977 5978 => imi 40100000 40200000 5979 5980 ## Checking Image at 40100000 ... 5981 Image Name: 2.2.13 for initrd on TQM850L 5982 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5983 Data Size: 335725 Bytes = 327 kB = 0 MB 5984 Load Address: 00000000 5985 Entry Point: 0000000c 5986 Verifying Checksum ... OK 5987 5988 ## Checking Image at 40200000 ... 5989 Image Name: Simple Ramdisk Image 5990 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5991 Data Size: 566530 Bytes = 553 kB = 0 MB 5992 Load Address: 00000000 5993 Entry Point: 00000000 5994 Verifying Checksum ... OK 5995 5996 => bootm 40100000 40200000 5997 ## Booting Linux kernel at 40100000 ... 5998 Image Name: 2.2.13 for initrd on TQM850L 5999 Image Type: PowerPC Linux Kernel Image (gzip compressed) 6000 Data Size: 335725 Bytes = 327 kB = 0 MB 6001 Load Address: 00000000 6002 Entry Point: 0000000c 6003 Verifying Checksum ... OK 6004 Uncompressing Kernel Image ... OK 6005 ## Loading RAMDisk Image at 40200000 ... 6006 Image Name: Simple Ramdisk Image 6007 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 6008 Data Size: 566530 Bytes = 553 kB = 0 MB 6009 Load Address: 00000000 6010 Entry Point: 00000000 6011 Verifying Checksum ... OK 6012 Loading Ramdisk ... OK 6013 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 6014 Boot arguments: root=/dev/ram 6015 time_init: decrementer frequency = 187500000/60 6016 Calibrating delay loop... 49.77 BogoMIPS 6017 ... 6018 RAMDISK: Compressed image found at block 0 6019 VFS: Mounted root (ext2 filesystem). 6020 6021 bash# 6022 6023Boot Linux and pass a flat device tree: 6024----------- 6025 6026First, U-Boot must be compiled with the appropriate defines. See the section 6027titled "Linux Kernel Interface" above for a more in depth explanation. The 6028following is an example of how to start a kernel and pass an updated 6029flat device tree: 6030 6031=> print oftaddr 6032oftaddr=0x300000 6033=> print oft 6034oft=oftrees/mpc8540ads.dtb 6035=> tftp $oftaddr $oft 6036Speed: 1000, full duplex 6037Using TSEC0 device 6038TFTP from server 192.168.1.1; our IP address is 192.168.1.101 6039Filename 'oftrees/mpc8540ads.dtb'. 6040Load address: 0x300000 6041Loading: # 6042done 6043Bytes transferred = 4106 (100a hex) 6044=> tftp $loadaddr $bootfile 6045Speed: 1000, full duplex 6046Using TSEC0 device 6047TFTP from server 192.168.1.1; our IP address is 192.168.1.2 6048Filename 'uImage'. 6049Load address: 0x200000 6050Loading:############ 6051done 6052Bytes transferred = 1029407 (fb51f hex) 6053=> print loadaddr 6054loadaddr=200000 6055=> print oftaddr 6056oftaddr=0x300000 6057=> bootm $loadaddr - $oftaddr 6058## Booting image at 00200000 ... 6059 Image Name: Linux-2.6.17-dirty 6060 Image Type: PowerPC Linux Kernel Image (gzip compressed) 6061 Data Size: 1029343 Bytes = 1005.2 kB 6062 Load Address: 00000000 6063 Entry Point: 00000000 6064 Verifying Checksum ... OK 6065 Uncompressing Kernel Image ... OK 6066Booting using flat device tree at 0x300000 6067Using MPC85xx ADS machine description 6068Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 6069[snip] 6070 6071 6072More About U-Boot Image Types: 6073------------------------------ 6074 6075U-Boot supports the following image types: 6076 6077 "Standalone Programs" are directly runnable in the environment 6078 provided by U-Boot; it is expected that (if they behave 6079 well) you can continue to work in U-Boot after return from 6080 the Standalone Program. 6081 "OS Kernel Images" are usually images of some Embedded OS which 6082 will take over control completely. Usually these programs 6083 will install their own set of exception handlers, device 6084 drivers, set up the MMU, etc. - this means, that you cannot 6085 expect to re-enter U-Boot except by resetting the CPU. 6086 "RAMDisk Images" are more or less just data blocks, and their 6087 parameters (address, size) are passed to an OS kernel that is 6088 being started. 6089 "Multi-File Images" contain several images, typically an OS 6090 (Linux) kernel image and one or more data images like 6091 RAMDisks. This construct is useful for instance when you want 6092 to boot over the network using BOOTP etc., where the boot 6093 server provides just a single image file, but you want to get 6094 for instance an OS kernel and a RAMDisk image. 6095 6096 "Multi-File Images" start with a list of image sizes, each 6097 image size (in bytes) specified by an "uint32_t" in network 6098 byte order. This list is terminated by an "(uint32_t)0". 6099 Immediately after the terminating 0 follow the images, one by 6100 one, all aligned on "uint32_t" boundaries (size rounded up to 6101 a multiple of 4 bytes). 6102 6103 "Firmware Images" are binary images containing firmware (like 6104 U-Boot or FPGA images) which usually will be programmed to 6105 flash memory. 6106 6107 "Script files" are command sequences that will be executed by 6108 U-Boot's command interpreter; this feature is especially 6109 useful when you configure U-Boot to use a real shell (hush) 6110 as command interpreter. 6111 6112Booting the Linux zImage: 6113------------------------- 6114 6115On some platforms, it's possible to boot Linux zImage. This is done 6116using the "bootz" command. The syntax of "bootz" command is the same 6117as the syntax of "bootm" command. 6118 6119Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 6120kernel with raw initrd images. The syntax is slightly different, the 6121address of the initrd must be augmented by it's size, in the following 6122format: "<initrd addres>:<initrd size>". 6123 6124 6125Standalone HOWTO: 6126================= 6127 6128One of the features of U-Boot is that you can dynamically load and 6129run "standalone" applications, which can use some resources of 6130U-Boot like console I/O functions or interrupt services. 6131 6132Two simple examples are included with the sources: 6133 6134"Hello World" Demo: 6135------------------- 6136 6137'examples/hello_world.c' contains a small "Hello World" Demo 6138application; it is automatically compiled when you build U-Boot. 6139It's configured to run at address 0x00040004, so you can play with it 6140like that: 6141 6142 => loads 6143 ## Ready for S-Record download ... 6144 ~>examples/hello_world.srec 6145 1 2 3 4 5 6 7 8 9 10 11 ... 6146 [file transfer complete] 6147 [connected] 6148 ## Start Addr = 0x00040004 6149 6150 => go 40004 Hello World! This is a test. 6151 ## Starting application at 0x00040004 ... 6152 Hello World 6153 argc = 7 6154 argv[0] = "40004" 6155 argv[1] = "Hello" 6156 argv[2] = "World!" 6157 argv[3] = "This" 6158 argv[4] = "is" 6159 argv[5] = "a" 6160 argv[6] = "test." 6161 argv[7] = "<NULL>" 6162 Hit any key to exit ... 6163 6164 ## Application terminated, rc = 0x0 6165 6166Another example, which demonstrates how to register a CPM interrupt 6167handler with the U-Boot code, can be found in 'examples/timer.c'. 6168Here, a CPM timer is set up to generate an interrupt every second. 6169The interrupt service routine is trivial, just printing a '.' 6170character, but this is just a demo program. The application can be 6171controlled by the following keys: 6172 6173 ? - print current values og the CPM Timer registers 6174 b - enable interrupts and start timer 6175 e - stop timer and disable interrupts 6176 q - quit application 6177 6178 => loads 6179 ## Ready for S-Record download ... 6180 ~>examples/timer.srec 6181 1 2 3 4 5 6 7 8 9 10 11 ... 6182 [file transfer complete] 6183 [connected] 6184 ## Start Addr = 0x00040004 6185 6186 => go 40004 6187 ## Starting application at 0x00040004 ... 6188 TIMERS=0xfff00980 6189 Using timer 1 6190 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 6191 6192Hit 'b': 6193 [q, b, e, ?] Set interval 1000000 us 6194 Enabling timer 6195Hit '?': 6196 [q, b, e, ?] ........ 6197 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 6198Hit '?': 6199 [q, b, e, ?] . 6200 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 6201Hit '?': 6202 [q, b, e, ?] . 6203 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 6204Hit '?': 6205 [q, b, e, ?] . 6206 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 6207Hit 'e': 6208 [q, b, e, ?] ...Stopping timer 6209Hit 'q': 6210 [q, b, e, ?] ## Application terminated, rc = 0x0 6211 6212 6213Minicom warning: 6214================ 6215 6216Over time, many people have reported problems when trying to use the 6217"minicom" terminal emulation program for serial download. I (wd) 6218consider minicom to be broken, and recommend not to use it. Under 6219Unix, I recommend to use C-Kermit for general purpose use (and 6220especially for kermit binary protocol download ("loadb" command), and 6221use "cu" for S-Record download ("loads" command). See 6222http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 6223for help with kermit. 6224 6225 6226Nevertheless, if you absolutely want to use it try adding this 6227configuration to your "File transfer protocols" section: 6228 6229 Name Program Name U/D FullScr IO-Red. Multi 6230 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 6231 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 6232 6233 6234NetBSD Notes: 6235============= 6236 6237Starting at version 0.9.2, U-Boot supports NetBSD both as host 6238(build U-Boot) and target system (boots NetBSD/mpc8xx). 6239 6240Building requires a cross environment; it is known to work on 6241NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 6242need gmake since the Makefiles are not compatible with BSD make). 6243Note that the cross-powerpc package does not install include files; 6244attempting to build U-Boot will fail because <machine/ansi.h> is 6245missing. This file has to be installed and patched manually: 6246 6247 # cd /usr/pkg/cross/powerpc-netbsd/include 6248 # mkdir powerpc 6249 # ln -s powerpc machine 6250 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 6251 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 6252 6253Native builds *don't* work due to incompatibilities between native 6254and U-Boot include files. 6255 6256Booting assumes that (the first part of) the image booted is a 6257stage-2 loader which in turn loads and then invokes the kernel 6258proper. Loader sources will eventually appear in the NetBSD source 6259tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 6260meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 6261 6262 6263Implementation Internals: 6264========================= 6265 6266The following is not intended to be a complete description of every 6267implementation detail. However, it should help to understand the 6268inner workings of U-Boot and make it easier to port it to custom 6269hardware. 6270 6271 6272Initial Stack, Global Data: 6273--------------------------- 6274 6275The implementation of U-Boot is complicated by the fact that U-Boot 6276starts running out of ROM (flash memory), usually without access to 6277system RAM (because the memory controller is not initialized yet). 6278This means that we don't have writable Data or BSS segments, and BSS 6279is not initialized as zero. To be able to get a C environment working 6280at all, we have to allocate at least a minimal stack. Implementation 6281options for this are defined and restricted by the CPU used: Some CPU 6282models provide on-chip memory (like the IMMR area on MPC8xx and 6283MPC826x processors), on others (parts of) the data cache can be 6284locked as (mis-) used as memory, etc. 6285 6286 Chris Hallinan posted a good summary of these issues to the 6287 U-Boot mailing list: 6288 6289 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 6290 From: "Chris Hallinan" <clh@net1plus.com> 6291 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 6292 ... 6293 6294 Correct me if I'm wrong, folks, but the way I understand it 6295 is this: Using DCACHE as initial RAM for Stack, etc, does not 6296 require any physical RAM backing up the cache. The cleverness 6297 is that the cache is being used as a temporary supply of 6298 necessary storage before the SDRAM controller is setup. It's 6299 beyond the scope of this list to explain the details, but you 6300 can see how this works by studying the cache architecture and 6301 operation in the architecture and processor-specific manuals. 6302 6303 OCM is On Chip Memory, which I believe the 405GP has 4K. It 6304 is another option for the system designer to use as an 6305 initial stack/RAM area prior to SDRAM being available. Either 6306 option should work for you. Using CS 4 should be fine if your 6307 board designers haven't used it for something that would 6308 cause you grief during the initial boot! It is frequently not 6309 used. 6310 6311 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 6312 with your processor/board/system design. The default value 6313 you will find in any recent u-boot distribution in 6314 walnut.h should work for you. I'd set it to a value larger 6315 than your SDRAM module. If you have a 64MB SDRAM module, set 6316 it above 400_0000. Just make sure your board has no resources 6317 that are supposed to respond to that address! That code in 6318 start.S has been around a while and should work as is when 6319 you get the config right. 6320 6321 -Chris Hallinan 6322 DS4.COM, Inc. 6323 6324It is essential to remember this, since it has some impact on the C 6325code for the initialization procedures: 6326 6327* Initialized global data (data segment) is read-only. Do not attempt 6328 to write it. 6329 6330* Do not use any uninitialized global data (or implicitly initialized 6331 as zero data - BSS segment) at all - this is undefined, initiali- 6332 zation is performed later (when relocating to RAM). 6333 6334* Stack space is very limited. Avoid big data buffers or things like 6335 that. 6336 6337Having only the stack as writable memory limits means we cannot use 6338normal global data to share information between the code. But it 6339turned out that the implementation of U-Boot can be greatly 6340simplified by making a global data structure (gd_t) available to all 6341functions. We could pass a pointer to this data as argument to _all_ 6342functions, but this would bloat the code. Instead we use a feature of 6343the GCC compiler (Global Register Variables) to share the data: we 6344place a pointer (gd) to the global data into a register which we 6345reserve for this purpose. 6346 6347When choosing a register for such a purpose we are restricted by the 6348relevant (E)ABI specifications for the current architecture, and by 6349GCC's implementation. 6350 6351For PowerPC, the following registers have specific use: 6352 R1: stack pointer 6353 R2: reserved for system use 6354 R3-R4: parameter passing and return values 6355 R5-R10: parameter passing 6356 R13: small data area pointer 6357 R30: GOT pointer 6358 R31: frame pointer 6359 6360 (U-Boot also uses R12 as internal GOT pointer. r12 6361 is a volatile register so r12 needs to be reset when 6362 going back and forth between asm and C) 6363 6364 ==> U-Boot will use R2 to hold a pointer to the global data 6365 6366 Note: on PPC, we could use a static initializer (since the 6367 address of the global data structure is known at compile time), 6368 but it turned out that reserving a register results in somewhat 6369 smaller code - although the code savings are not that big (on 6370 average for all boards 752 bytes for the whole U-Boot image, 6371 624 text + 127 data). 6372 6373On Blackfin, the normal C ABI (except for P3) is followed as documented here: 6374 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface 6375 6376 ==> U-Boot will use P3 to hold a pointer to the global data 6377 6378On ARM, the following registers are used: 6379 6380 R0: function argument word/integer result 6381 R1-R3: function argument word 6382 R9: platform specific 6383 R10: stack limit (used only if stack checking is enabled) 6384 R11: argument (frame) pointer 6385 R12: temporary workspace 6386 R13: stack pointer 6387 R14: link register 6388 R15: program counter 6389 6390 ==> U-Boot will use R9 to hold a pointer to the global data 6391 6392 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 6393 6394On Nios II, the ABI is documented here: 6395 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 6396 6397 ==> U-Boot will use gp to hold a pointer to the global data 6398 6399 Note: on Nios II, we give "-G0" option to gcc and don't use gp 6400 to access small data sections, so gp is free. 6401 6402On NDS32, the following registers are used: 6403 6404 R0-R1: argument/return 6405 R2-R5: argument 6406 R15: temporary register for assembler 6407 R16: trampoline register 6408 R28: frame pointer (FP) 6409 R29: global pointer (GP) 6410 R30: link register (LP) 6411 R31: stack pointer (SP) 6412 PC: program counter (PC) 6413 6414 ==> U-Boot will use R10 to hold a pointer to the global data 6415 6416NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 6417or current versions of GCC may "optimize" the code too much. 6418 6419Memory Management: 6420------------------ 6421 6422U-Boot runs in system state and uses physical addresses, i.e. the 6423MMU is not used either for address mapping nor for memory protection. 6424 6425The available memory is mapped to fixed addresses using the memory 6426controller. In this process, a contiguous block is formed for each 6427memory type (Flash, SDRAM, SRAM), even when it consists of several 6428physical memory banks. 6429 6430U-Boot is installed in the first 128 kB of the first Flash bank (on 6431TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 6432booting and sizing and initializing DRAM, the code relocates itself 6433to the upper end of DRAM. Immediately below the U-Boot code some 6434memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 6435configuration setting]. Below that, a structure with global Board 6436Info data is placed, followed by the stack (growing downward). 6437 6438Additionally, some exception handler code is copied to the low 8 kB 6439of DRAM (0x00000000 ... 0x00001FFF). 6440 6441So a typical memory configuration with 16 MB of DRAM could look like 6442this: 6443 6444 0x0000 0000 Exception Vector code 6445 : 6446 0x0000 1FFF 6447 0x0000 2000 Free for Application Use 6448 : 6449 : 6450 6451 : 6452 : 6453 0x00FB FF20 Monitor Stack (Growing downward) 6454 0x00FB FFAC Board Info Data and permanent copy of global data 6455 0x00FC 0000 Malloc Arena 6456 : 6457 0x00FD FFFF 6458 0x00FE 0000 RAM Copy of Monitor Code 6459 ... eventually: LCD or video framebuffer 6460 ... eventually: pRAM (Protected RAM - unchanged by reset) 6461 0x00FF FFFF [End of RAM] 6462 6463 6464System Initialization: 6465---------------------- 6466 6467In the reset configuration, U-Boot starts at the reset entry point 6468(on most PowerPC systems at address 0x00000100). Because of the reset 6469configuration for CS0# this is a mirror of the on board Flash memory. 6470To be able to re-map memory U-Boot then jumps to its link address. 6471To be able to implement the initialization code in C, a (small!) 6472initial stack is set up in the internal Dual Ported RAM (in case CPUs 6473which provide such a feature like MPC8xx or MPC8260), or in a locked 6474part of the data cache. After that, U-Boot initializes the CPU core, 6475the caches and the SIU. 6476 6477Next, all (potentially) available memory banks are mapped using a 6478preliminary mapping. For example, we put them on 512 MB boundaries 6479(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 6480on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 6481programmed for SDRAM access. Using the temporary configuration, a 6482simple memory test is run that determines the size of the SDRAM 6483banks. 6484 6485When there is more than one SDRAM bank, and the banks are of 6486different size, the largest is mapped first. For equal size, the first 6487bank (CS2#) is mapped first. The first mapping is always for address 64880x00000000, with any additional banks following immediately to create 6489contiguous memory starting from 0. 6490 6491Then, the monitor installs itself at the upper end of the SDRAM area 6492and allocates memory for use by malloc() and for the global Board 6493Info data; also, the exception vector code is copied to the low RAM 6494pages, and the final stack is set up. 6495 6496Only after this relocation will you have a "normal" C environment; 6497until that you are restricted in several ways, mostly because you are 6498running from ROM, and because the code will have to be relocated to a 6499new address in RAM. 6500 6501 6502U-Boot Porting Guide: 6503---------------------- 6504 6505[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 6506list, October 2002] 6507 6508 6509int main(int argc, char *argv[]) 6510{ 6511 sighandler_t no_more_time; 6512 6513 signal(SIGALRM, no_more_time); 6514 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 6515 6516 if (available_money > available_manpower) { 6517 Pay consultant to port U-Boot; 6518 return 0; 6519 } 6520 6521 Download latest U-Boot source; 6522 6523 Subscribe to u-boot mailing list; 6524 6525 if (clueless) 6526 email("Hi, I am new to U-Boot, how do I get started?"); 6527 6528 while (learning) { 6529 Read the README file in the top level directory; 6530 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 6531 Read applicable doc/*.README; 6532 Read the source, Luke; 6533 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 6534 } 6535 6536 if (available_money > toLocalCurrency ($2500)) 6537 Buy a BDI3000; 6538 else 6539 Add a lot of aggravation and time; 6540 6541 if (a similar board exists) { /* hopefully... */ 6542 cp -a board/<similar> board/<myboard> 6543 cp include/configs/<similar>.h include/configs/<myboard>.h 6544 } else { 6545 Create your own board support subdirectory; 6546 Create your own board include/configs/<myboard>.h file; 6547 } 6548 Edit new board/<myboard> files 6549 Edit new include/configs/<myboard>.h 6550 6551 while (!accepted) { 6552 while (!running) { 6553 do { 6554 Add / modify source code; 6555 } until (compiles); 6556 Debug; 6557 if (clueless) 6558 email("Hi, I am having problems..."); 6559 } 6560 Send patch file to the U-Boot email list; 6561 if (reasonable critiques) 6562 Incorporate improvements from email list code review; 6563 else 6564 Defend code as written; 6565 } 6566 6567 return 0; 6568} 6569 6570void no_more_time (int sig) 6571{ 6572 hire_a_guru(); 6573} 6574 6575 6576Coding Standards: 6577----------------- 6578 6579All contributions to U-Boot should conform to the Linux kernel 6580coding style; see the file "Documentation/CodingStyle" and the script 6581"scripts/Lindent" in your Linux kernel source directory. 6582 6583Source files originating from a different project (for example the 6584MTD subsystem) are generally exempt from these guidelines and are not 6585reformatted to ease subsequent migration to newer versions of those 6586sources. 6587 6588Please note that U-Boot is implemented in C (and to some small parts in 6589Assembler); no C++ is used, so please do not use C++ style comments (//) 6590in your code. 6591 6592Please also stick to the following formatting rules: 6593- remove any trailing white space 6594- use TAB characters for indentation and vertical alignment, not spaces 6595- make sure NOT to use DOS '\r\n' line feeds 6596- do not add more than 2 consecutive empty lines to source files 6597- do not add trailing empty lines to source files 6598 6599Submissions which do not conform to the standards may be returned 6600with a request to reformat the changes. 6601 6602 6603Submitting Patches: 6604------------------- 6605 6606Since the number of patches for U-Boot is growing, we need to 6607establish some rules. Submissions which do not conform to these rules 6608may be rejected, even when they contain important and valuable stuff. 6609 6610Please see http://www.denx.de/wiki/U-Boot/Patches for details. 6611 6612Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 6613see http://lists.denx.de/mailman/listinfo/u-boot 6614 6615When you send a patch, please include the following information with 6616it: 6617 6618* For bug fixes: a description of the bug and how your patch fixes 6619 this bug. Please try to include a way of demonstrating that the 6620 patch actually fixes something. 6621 6622* For new features: a description of the feature and your 6623 implementation. 6624 6625* A CHANGELOG entry as plaintext (separate from the patch) 6626 6627* For major contributions, your entry to the CREDITS file 6628 6629* When you add support for a new board, don't forget to add a 6630 maintainer e-mail address to the boards.cfg file, too. 6631 6632* If your patch adds new configuration options, don't forget to 6633 document these in the README file. 6634 6635* The patch itself. If you are using git (which is *strongly* 6636 recommended) you can easily generate the patch using the 6637 "git format-patch". If you then use "git send-email" to send it to 6638 the U-Boot mailing list, you will avoid most of the common problems 6639 with some other mail clients. 6640 6641 If you cannot use git, use "diff -purN OLD NEW". If your version of 6642 diff does not support these options, then get the latest version of 6643 GNU diff. 6644 6645 The current directory when running this command shall be the parent 6646 directory of the U-Boot source tree (i. e. please make sure that 6647 your patch includes sufficient directory information for the 6648 affected files). 6649 6650 We prefer patches as plain text. MIME attachments are discouraged, 6651 and compressed attachments must not be used. 6652 6653* If one logical set of modifications affects or creates several 6654 files, all these changes shall be submitted in a SINGLE patch file. 6655 6656* Changesets that contain different, unrelated modifications shall be 6657 submitted as SEPARATE patches, one patch per changeset. 6658 6659 6660Notes: 6661 6662* Before sending the patch, run the MAKEALL script on your patched 6663 source tree and make sure that no errors or warnings are reported 6664 for any of the boards. 6665 6666* Keep your modifications to the necessary minimum: A patch 6667 containing several unrelated changes or arbitrary reformats will be 6668 returned with a request to re-formatting / split it. 6669 6670* If you modify existing code, make sure that your new code does not 6671 add to the memory footprint of the code ;-) Small is beautiful! 6672 When adding new features, these should compile conditionally only 6673 (using #ifdef), and the resulting code with the new feature 6674 disabled must not need more memory than the old code without your 6675 modification. 6676 6677* Remember that there is a size limit of 100 kB per message on the 6678 u-boot mailing list. Bigger patches will be moderated. If they are 6679 reasonable and not too big, they will be acknowledged. But patches 6680 bigger than the size limit should be avoided. 6681