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 file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /m68k Files generic to m68k architecture 140 /microblaze Files generic to microblaze architecture 141 /mips Files generic to MIPS architecture 142 /nds32 Files generic to NDS32 architecture 143 /nios2 Files generic to Altera NIOS2 architecture 144 /openrisc Files generic to OpenRISC architecture 145 /powerpc Files generic to PowerPC architecture 146 /sandbox Files generic to HW-independent "sandbox" 147 /sh Files generic to SH architecture 148 /x86 Files generic to x86 architecture 149/api Machine/arch independent API for external apps 150/board Board dependent files 151/cmd U-Boot commands functions 152/common Misc architecture independent functions 153/configs Board default configuration files 154/disk Code for disk drive partition handling 155/doc Documentation (don't expect too much) 156/drivers Commonly used device drivers 157/dts Contains Makefile for building internal U-Boot fdt. 158/examples Example code for standalone applications, etc. 159/fs Filesystem code (cramfs, ext2, jffs2, etc.) 160/include Header Files 161/lib Library routines generic to all architectures 162/Licenses Various license files 163/net Networking code 164/post Power On Self Test 165/scripts Various build scripts and Makefiles 166/test Various unit test files 167/tools Tools to build S-Record or U-Boot images, etc. 168 169Software Configuration: 170======================= 171 172Configuration is usually done using C preprocessor defines; the 173rationale behind that is to avoid dead code whenever possible. 174 175There are two classes of configuration variables: 176 177* Configuration _OPTIONS_: 178 These are selectable by the user and have names beginning with 179 "CONFIG_". 180 181* Configuration _SETTINGS_: 182 These depend on the hardware etc. and should not be meddled with if 183 you don't know what you're doing; they have names beginning with 184 "CONFIG_SYS_". 185 186Previously, all configuration was done by hand, which involved creating 187symbolic links and editing configuration files manually. More recently, 188U-Boot has added the Kbuild infrastructure used by the Linux kernel, 189allowing you to use the "make menuconfig" command to configure your 190build. 191 192 193Selection of Processor Architecture and Board Type: 194--------------------------------------------------- 195 196For all supported boards there are ready-to-use default 197configurations available; just type "make <board_name>_defconfig". 198 199Example: For a TQM823L module type: 200 201 cd u-boot 202 make TQM823L_defconfig 203 204Note: If you're looking for the default configuration file for a board 205you're sure used to be there but is now missing, check the file 206doc/README.scrapyard for a list of no longer supported boards. 207 208Sandbox Environment: 209-------------------- 210 211U-Boot can be built natively to run on a Linux host using the 'sandbox' 212board. This allows feature development which is not board- or architecture- 213specific to be undertaken on a native platform. The sandbox is also used to 214run some of U-Boot's tests. 215 216See board/sandbox/README.sandbox for more details. 217 218 219Board Initialisation Flow: 220-------------------------- 221 222This is the intended start-up flow for boards. This should apply for both 223SPL and U-Boot proper (i.e. they both follow the same rules). 224 225Note: "SPL" stands for "Secondary Program Loader," which is explained in 226more detail later in this file. 227 228At present, SPL mostly uses a separate code path, but the function names 229and roles of each function are the same. Some boards or architectures 230may not conform to this. At least most ARM boards which use 231CONFIG_SPL_FRAMEWORK conform to this. 232 233Execution typically starts with an architecture-specific (and possibly 234CPU-specific) start.S file, such as: 235 236 - arch/arm/cpu/armv7/start.S 237 - arch/powerpc/cpu/mpc83xx/start.S 238 - arch/mips/cpu/start.S 239 240and so on. From there, three functions are called; the purpose and 241limitations of each of these functions are described below. 242 243lowlevel_init(): 244 - purpose: essential init to permit execution to reach board_init_f() 245 - no global_data or BSS 246 - there is no stack (ARMv7 may have one but it will soon be removed) 247 - must not set up SDRAM or use console 248 - must only do the bare minimum to allow execution to continue to 249 board_init_f() 250 - this is almost never needed 251 - return normally from this function 252 253board_init_f(): 254 - purpose: set up the machine ready for running board_init_r(): 255 i.e. SDRAM and serial UART 256 - global_data is available 257 - stack is in SRAM 258 - BSS is not available, so you cannot use global/static variables, 259 only stack variables and global_data 260 261 Non-SPL-specific notes: 262 - dram_init() is called to set up DRAM. If already done in SPL this 263 can do nothing 264 265 SPL-specific notes: 266 - you can override the entire board_init_f() function with your own 267 version as needed. 268 - preloader_console_init() can be called here in extremis 269 - should set up SDRAM, and anything needed to make the UART work 270 - these is no need to clear BSS, it will be done by crt0.S 271 - must return normally from this function (don't call board_init_r() 272 directly) 273 274Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 275this point the stack and global_data are relocated to below 276CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 277memory. 278 279board_init_r(): 280 - purpose: main execution, common code 281 - global_data is available 282 - SDRAM is available 283 - BSS is available, all static/global variables can be used 284 - execution eventually continues to main_loop() 285 286 Non-SPL-specific notes: 287 - U-Boot is relocated to the top of memory and is now running from 288 there. 289 290 SPL-specific notes: 291 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 292 CONFIG_SPL_STACK_R_ADDR points into SDRAM 293 - preloader_console_init() can be called here - typically this is 294 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 295 spl_board_init() function containing this call 296 - loads U-Boot or (in falcon mode) Linux 297 298 299 300Configuration Options: 301---------------------- 302 303Configuration depends on the combination of board and CPU type; all 304such information is kept in a configuration file 305"include/configs/<board_name>.h". 306 307Example: For a TQM823L module, all configuration settings are in 308"include/configs/TQM823L.h". 309 310 311Many of the options are named exactly as the corresponding Linux 312kernel configuration options. The intention is to make it easier to 313build a config tool - later. 314 315 316The following options need to be configured: 317 318- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 319 320- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 321 322- Marvell Family Member 323 CONFIG_SYS_MVFS - define it if you want to enable 324 multiple fs option at one time 325 for marvell soc family 326 327- 85xx CPU Options: 328 CONFIG_SYS_PPC64 329 330 Specifies that the core is a 64-bit PowerPC implementation (implements 331 the "64" category of the Power ISA). This is necessary for ePAPR 332 compliance, among other possible reasons. 333 334 CONFIG_SYS_FSL_TBCLK_DIV 335 336 Defines the core time base clock divider ratio compared to the 337 system clock. On most PQ3 devices this is 8, on newer QorIQ 338 devices it can be 16 or 32. The ratio varies from SoC to Soc. 339 340 CONFIG_SYS_FSL_PCIE_COMPAT 341 342 Defines the string to utilize when trying to match PCIe device 343 tree nodes for the given platform. 344 345 CONFIG_SYS_FSL_ERRATUM_A004510 346 347 Enables a workaround for erratum A004510. If set, 348 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 350 351 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 352 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 353 354 Defines one or two SoC revisions (low 8 bits of SVR) 355 for which the A004510 workaround should be applied. 356 357 The rest of SVR is either not relevant to the decision 358 of whether the erratum is present (e.g. p2040 versus 359 p2041) or is implied by the build target, which controls 360 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 361 362 See Freescale App Note 4493 for more information about 363 this erratum. 364 365 CONFIG_A003399_NOR_WORKAROUND 366 Enables a workaround for IFC erratum A003399. It is only 367 required during NOR boot. 368 369 CONFIG_A008044_WORKAROUND 370 Enables a workaround for T1040/T1042 erratum A008044. It is only 371 required during NAND boot and valid for Rev 1.0 SoC revision 372 373 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 374 375 This is the value to write into CCSR offset 0x18600 376 according to the A004510 workaround. 377 378 CONFIG_SYS_FSL_DSP_DDR_ADDR 379 This value denotes start offset of DDR memory which is 380 connected exclusively to the DSP cores. 381 382 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 383 This value denotes start offset of M2 memory 384 which is directly connected to the DSP core. 385 386 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 387 This value denotes start offset of M3 memory which is directly 388 connected to the DSP core. 389 390 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 391 This value denotes start offset of DSP CCSR space. 392 393 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 394 Single Source Clock is clocking mode present in some of FSL SoC's. 395 In this mode, a single differential clock is used to supply 396 clocks to the sysclock, ddrclock and usbclock. 397 398 CONFIG_SYS_CPC_REINIT_F 399 This CONFIG is defined when the CPC is configured as SRAM at the 400 time of U-Boot entry and is required to be re-initialized. 401 402 CONFIG_DEEP_SLEEP 403 Indicates this SoC supports deep sleep feature. If deep sleep is 404 supported, core will start to execute uboot when wakes up. 405 406- Generic CPU options: 407 CONFIG_SYS_GENERIC_GLOBAL_DATA 408 Defines global data is initialized in generic board board_init_f(). 409 If this macro is defined, global data is created and cleared in 410 generic board board_init_f(). Without this macro, architecture/board 411 should initialize global data before calling board_init_f(). 412 413 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 414 415 Defines the endianess of the CPU. Implementation of those 416 values is arch specific. 417 418 CONFIG_SYS_FSL_DDR 419 Freescale DDR driver in use. This type of DDR controller is 420 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 421 SoCs. 422 423 CONFIG_SYS_FSL_DDR_ADDR 424 Freescale DDR memory-mapped register base. 425 426 CONFIG_SYS_FSL_DDR_EMU 427 Specify emulator support for DDR. Some DDR features such as 428 deskew training are not available. 429 430 CONFIG_SYS_FSL_DDRC_GEN1 431 Freescale DDR1 controller. 432 433 CONFIG_SYS_FSL_DDRC_GEN2 434 Freescale DDR2 controller. 435 436 CONFIG_SYS_FSL_DDRC_GEN3 437 Freescale DDR3 controller. 438 439 CONFIG_SYS_FSL_DDRC_GEN4 440 Freescale DDR4 controller. 441 442 CONFIG_SYS_FSL_DDRC_ARM_GEN3 443 Freescale DDR3 controller for ARM-based SoCs. 444 445 CONFIG_SYS_FSL_DDR1 446 Board config to use DDR1. It can be enabled for SoCs with 447 Freescale DDR1 or DDR2 controllers, depending on the board 448 implemetation. 449 450 CONFIG_SYS_FSL_DDR2 451 Board config to use DDR2. It can be enabled for SoCs with 452 Freescale DDR2 or DDR3 controllers, depending on the board 453 implementation. 454 455 CONFIG_SYS_FSL_DDR3 456 Board config to use DDR3. It can be enabled for SoCs with 457 Freescale DDR3 or DDR3L controllers. 458 459 CONFIG_SYS_FSL_DDR3L 460 Board config to use DDR3L. It can be enabled for SoCs with 461 DDR3L controllers. 462 463 CONFIG_SYS_FSL_DDR4 464 Board config to use DDR4. It can be enabled for SoCs with 465 DDR4 controllers. 466 467 CONFIG_SYS_FSL_IFC_BE 468 Defines the IFC controller register space as Big Endian 469 470 CONFIG_SYS_FSL_IFC_LE 471 Defines the IFC controller register space as Little Endian 472 473 CONFIG_SYS_FSL_IFC_CLK_DIV 474 Defines divider of platform clock(clock input to IFC controller). 475 476 CONFIG_SYS_FSL_LBC_CLK_DIV 477 Defines divider of platform clock(clock input to eLBC controller). 478 479 CONFIG_SYS_FSL_PBL_PBI 480 It enables addition of RCW (Power on reset configuration) in built image. 481 Please refer doc/README.pblimage for more details 482 483 CONFIG_SYS_FSL_PBL_RCW 484 It adds PBI(pre-boot instructions) commands in u-boot build image. 485 PBI commands can be used to configure SoC before it starts the execution. 486 Please refer doc/README.pblimage for more details 487 488 CONFIG_SPL_FSL_PBL 489 It adds a target to create boot binary having SPL binary in PBI format 490 concatenated with u-boot binary. 491 492 CONFIG_SYS_FSL_DDR_BE 493 Defines the DDR controller register space as Big Endian 494 495 CONFIG_SYS_FSL_DDR_LE 496 Defines the DDR controller register space as Little Endian 497 498 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 499 Physical address from the view of DDR controllers. It is the 500 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 501 it could be different for ARM SoCs. 502 503 CONFIG_SYS_FSL_DDR_INTLV_256B 504 DDR controller interleaving on 256-byte. This is a special 505 interleaving mode, handled by Dickens for Freescale layerscape 506 SoCs with ARM core. 507 508 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 509 Number of controllers used as main memory. 510 511 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 512 Number of controllers used for other than main memory. 513 514 CONFIG_SYS_FSL_HAS_DP_DDR 515 Defines the SoC has DP-DDR used for DPAA. 516 517 CONFIG_SYS_FSL_SEC_BE 518 Defines the SEC controller register space as Big Endian 519 520 CONFIG_SYS_FSL_SEC_LE 521 Defines the SEC controller register space as Little Endian 522 523- MIPS CPU options: 524 CONFIG_SYS_INIT_SP_OFFSET 525 526 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 527 pointer. This is needed for the temporary stack before 528 relocation. 529 530 CONFIG_SYS_MIPS_CACHE_MODE 531 532 Cache operation mode for the MIPS CPU. 533 See also arch/mips/include/asm/mipsregs.h. 534 Possible values are: 535 CONF_CM_CACHABLE_NO_WA 536 CONF_CM_CACHABLE_WA 537 CONF_CM_UNCACHED 538 CONF_CM_CACHABLE_NONCOHERENT 539 CONF_CM_CACHABLE_CE 540 CONF_CM_CACHABLE_COW 541 CONF_CM_CACHABLE_CUW 542 CONF_CM_CACHABLE_ACCELERATED 543 544 CONFIG_SYS_XWAY_EBU_BOOTCFG 545 546 Special option for Lantiq XWAY SoCs for booting from NOR flash. 547 See also arch/mips/cpu/mips32/start.S. 548 549 CONFIG_XWAY_SWAP_BYTES 550 551 Enable compilation of tools/xway-swap-bytes needed for Lantiq 552 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 553 be swapped if a flash programmer is used. 554 555- ARM options: 556 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 557 558 Select high exception vectors of the ARM core, e.g., do not 559 clear the V bit of the c1 register of CP15. 560 561 COUNTER_FREQUENCY 562 Generic timer clock source frequency. 563 564 COUNTER_FREQUENCY_REAL 565 Generic timer clock source frequency if the real clock is 566 different from COUNTER_FREQUENCY, and can only be determined 567 at run time. 568 569- Tegra SoC options: 570 CONFIG_TEGRA_SUPPORT_NON_SECURE 571 572 Support executing U-Boot in non-secure (NS) mode. Certain 573 impossible actions will be skipped if the CPU is in NS mode, 574 such as ARM architectural timer initialization. 575 576- Linux Kernel Interface: 577 CONFIG_CLOCKS_IN_MHZ 578 579 U-Boot stores all clock information in Hz 580 internally. For binary compatibility with older Linux 581 kernels (which expect the clocks passed in the 582 bd_info data to be in MHz) the environment variable 583 "clocks_in_mhz" can be defined so that U-Boot 584 converts clock data to MHZ before passing it to the 585 Linux kernel. 586 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 587 "clocks_in_mhz=1" is automatically included in the 588 default environment. 589 590 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 591 592 When transferring memsize parameter to Linux, some versions 593 expect it to be in bytes, others in MB. 594 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 595 596 CONFIG_OF_LIBFDT 597 598 New kernel versions are expecting firmware settings to be 599 passed using flattened device trees (based on open firmware 600 concepts). 601 602 CONFIG_OF_LIBFDT 603 * New libfdt-based support 604 * Adds the "fdt" command 605 * The bootm command automatically updates the fdt 606 607 OF_TBCLK - The timebase frequency. 608 OF_STDOUT_PATH - The path to the console device 609 610 boards with QUICC Engines require OF_QE to set UCC MAC 611 addresses 612 613 CONFIG_OF_BOARD_SETUP 614 615 Board code has addition modification that it wants to make 616 to the flat device tree before handing it off to the kernel 617 618 CONFIG_OF_SYSTEM_SETUP 619 620 Other code has addition modification that it wants to make 621 to the flat device tree before handing it off to the kernel. 622 This causes ft_system_setup() to be called before booting 623 the kernel. 624 625 CONFIG_OF_IDE_FIXUP 626 627 U-Boot can detect if an IDE device is present or not. 628 If not, and this new config option is activated, U-Boot 629 removes the ATA node from the DTS before booting Linux, 630 so the Linux IDE driver does not probe the device and 631 crash. This is needed for buggy hardware (uc101) where 632 no pull down resistor is connected to the signal IDE5V_DD7. 633 634 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 635 636 This setting is mandatory for all boards that have only one 637 machine type and must be used to specify the machine type 638 number as it appears in the ARM machine registry 639 (see http://www.arm.linux.org.uk/developer/machines/). 640 Only boards that have multiple machine types supported 641 in a single configuration file and the machine type is 642 runtime discoverable, do not have to use this setting. 643 644- vxWorks boot parameters: 645 646 bootvx constructs a valid bootline using the following 647 environments variables: bootdev, bootfile, ipaddr, netmask, 648 serverip, gatewayip, hostname, othbootargs. 649 It loads the vxWorks image pointed bootfile. 650 651 Note: If a "bootargs" environment is defined, it will overwride 652 the defaults discussed just above. 653 654- Cache Configuration: 655 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 656 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 657 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 658 659- Cache Configuration for ARM: 660 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 661 controller 662 CONFIG_SYS_PL310_BASE - Physical base address of PL310 663 controller register space 664 665- Serial Ports: 666 CONFIG_PL010_SERIAL 667 668 Define this if you want support for Amba PrimeCell PL010 UARTs. 669 670 CONFIG_PL011_SERIAL 671 672 Define this if you want support for Amba PrimeCell PL011 UARTs. 673 674 CONFIG_PL011_CLOCK 675 676 If you have Amba PrimeCell PL011 UARTs, set this variable to 677 the clock speed of the UARTs. 678 679 CONFIG_PL01x_PORTS 680 681 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 682 define this to a list of base addresses for each (supported) 683 port. See e.g. include/configs/versatile.h 684 685 CONFIG_SERIAL_HW_FLOW_CONTROL 686 687 Define this variable to enable hw flow control in serial driver. 688 Current user of this option is drivers/serial/nsl16550.c driver 689 690- Console Baudrate: 691 CONFIG_BAUDRATE - in bps 692 Select one of the baudrates listed in 693 CONFIG_SYS_BAUDRATE_TABLE, see below. 694 695- Autoboot Command: 696 CONFIG_BOOTCOMMAND 697 Only needed when CONFIG_BOOTDELAY is enabled; 698 define a command string that is automatically executed 699 when no character is read on the console interface 700 within "Boot Delay" after reset. 701 702 CONFIG_BOOTARGS 703 This can be used to pass arguments to the bootm 704 command. The value of CONFIG_BOOTARGS goes into the 705 environment value "bootargs". 706 707 CONFIG_RAMBOOT and CONFIG_NFSBOOT 708 The value of these goes into the environment as 709 "ramboot" and "nfsboot" respectively, and can be used 710 as a convenience, when switching between booting from 711 RAM and NFS. 712 713- Bootcount: 714 CONFIG_BOOTCOUNT_LIMIT 715 Implements a mechanism for detecting a repeating reboot 716 cycle, see: 717 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 718 719 CONFIG_BOOTCOUNT_ENV 720 If no softreset save registers are found on the hardware 721 "bootcount" is stored in the environment. To prevent a 722 saveenv on all reboots, the environment variable 723 "upgrade_available" is used. If "upgrade_available" is 724 0, "bootcount" is always 0, if "upgrade_available" is 725 1 "bootcount" is incremented in the environment. 726 So the Userspace Applikation must set the "upgrade_available" 727 and "bootcount" variable to 0, if a boot was successfully. 728 729- Pre-Boot Commands: 730 CONFIG_PREBOOT 731 732 When this option is #defined, the existence of the 733 environment variable "preboot" will be checked 734 immediately before starting the CONFIG_BOOTDELAY 735 countdown and/or running the auto-boot command resp. 736 entering interactive mode. 737 738 This feature is especially useful when "preboot" is 739 automatically generated or modified. For an example 740 see the LWMON board specific code: here "preboot" is 741 modified when the user holds down a certain 742 combination of keys on the (special) keyboard when 743 booting the systems 744 745- Serial Download Echo Mode: 746 CONFIG_LOADS_ECHO 747 If defined to 1, all characters received during a 748 serial download (using the "loads" command) are 749 echoed back. This might be needed by some terminal 750 emulations (like "cu"), but may as well just take 751 time on others. This setting #define's the initial 752 value of the "loads_echo" environment variable. 753 754- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 755 CONFIG_KGDB_BAUDRATE 756 Select one of the baudrates listed in 757 CONFIG_SYS_BAUDRATE_TABLE, see below. 758 759- Monitor Functions: 760 Monitor commands can be included or excluded 761 from the build by using the #include files 762 <config_cmd_all.h> and #undef'ing unwanted 763 commands, or adding #define's for wanted commands. 764 765 The default command configuration includes all commands 766 except those marked below with a "*". 767 768 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 769 CONFIG_CMD_ASKENV * ask for env variable 770 CONFIG_CMD_BDI bdinfo 771 CONFIG_CMD_BOOTD bootd 772 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 773 CONFIG_CMD_CACHE * icache, dcache 774 CONFIG_CMD_CONSOLE coninfo 775 CONFIG_CMD_DHCP * DHCP support 776 CONFIG_CMD_DIAG * Diagnostics 777 CONFIG_CMD_ECHO echo arguments 778 CONFIG_CMD_EDITENV edit env variable 779 CONFIG_CMD_ELF * bootelf, bootvx 780 CONFIG_CMD_ENV_EXISTS * check existence of env variable 781 CONFIG_CMD_EXPORTENV * export the environment 782 CONFIG_CMD_EXT2 * ext2 command support 783 CONFIG_CMD_EXT4 * ext4 command support 784 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 785 that work for multiple fs types 786 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 787 CONFIG_CMD_SAVEENV saveenv 788 CONFIG_CMD_FLASH flinfo, erase, protect 789 CONFIG_CMD_FPGA FPGA device initialization support 790 CONFIG_CMD_GO * the 'go' command (exec code) 791 CONFIG_CMD_GREPENV * search environment 792 CONFIG_CMD_I2C * I2C serial bus support 793 CONFIG_CMD_IMI iminfo 794 CONFIG_CMD_IMLS List all images found in NOR flash 795 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 796 CONFIG_CMD_IMPORTENV * import an environment 797 CONFIG_CMD_INI * import data from an ini file into the env 798 CONFIG_CMD_ITEST Integer/string test of 2 values 799 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 800 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 801 (169.254.*.*) 802 CONFIG_CMD_LOADB loadb 803 CONFIG_CMD_LOADS loads 804 CONFIG_CMD_MD5SUM * print md5 message digest 805 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 806 CONFIG_CMD_MEMINFO * Display detailed memory information 807 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 808 loop, loopw 809 CONFIG_CMD_MEMTEST * mtest 810 CONFIG_CMD_MISC Misc functions like sleep etc 811 CONFIG_CMD_MMC * MMC memory mapped support 812 CONFIG_CMD_MII * MII utility commands 813 CONFIG_CMD_NET bootp, tftpboot, rarpboot 814 CONFIG_CMD_NFS NFS support 815 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 816 host 817 CONFIG_CMD_REGINFO * Register dump 818 CONFIG_CMD_RUN run command in env variable 819 CONFIG_CMD_SANDBOX * sb command to access sandbox features 820 CONFIG_CMD_SAVES * save S record dump 821 CONFIG_CMD_SDRAM * print SDRAM configuration information 822 (requires CONFIG_CMD_I2C) 823 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 824 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 825 CONFIG_CMD_SOURCE "source" command Support 826 CONFIG_CMD_SPI * SPI serial bus support 827 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 828 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 829 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 830 CONFIG_CMD_TIMER * access to the system tick timer 831 CONFIG_CMD_USB * USB support 832 CONFIG_CMD_CDP * Cisco Discover Protocol support 833 CONFIG_CMD_XIMG Load part of Multi Image 834 CONFIG_CMD_UUID * Generate random UUID or GUID string 835 836 EXAMPLE: If you want all functions except of network 837 support you can write: 838 839 #include "config_cmd_all.h" 840 #undef CONFIG_CMD_NET 841 842 Other Commands: 843 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 844 845 Note: Don't enable the "icache" and "dcache" commands 846 (configuration option CONFIG_CMD_CACHE) unless you know 847 what you (and your U-Boot users) are doing. Data 848 cache cannot be enabled on systems like the 849 8xx (where accesses to the IMMR region must be 850 uncached), and it cannot be disabled on all other 851 systems where we (mis-) use the data cache to hold an 852 initial stack and some data. 853 854 855 XXX - this list needs to get updated! 856 857- Removal of commands 858 If no commands are needed to boot, you can disable 859 CONFIG_CMDLINE to remove them. In this case, the command line 860 will not be available, and when U-Boot wants to execute the 861 boot command (on start-up) it will call board_run_command() 862 instead. This can reduce image size significantly for very 863 simple boot procedures. 864 865- Regular expression support: 866 CONFIG_REGEX 867 If this variable is defined, U-Boot is linked against 868 the SLRE (Super Light Regular Expression) library, 869 which adds regex support to some commands, as for 870 example "env grep" and "setexpr". 871 872- Device tree: 873 CONFIG_OF_CONTROL 874 If this variable is defined, U-Boot will use a device tree 875 to configure its devices, instead of relying on statically 876 compiled #defines in the board file. This option is 877 experimental and only available on a few boards. The device 878 tree is available in the global data as gd->fdt_blob. 879 880 U-Boot needs to get its device tree from somewhere. This can 881 be done using one of the three options below: 882 883 CONFIG_OF_EMBED 884 If this variable is defined, U-Boot will embed a device tree 885 binary in its image. This device tree file should be in the 886 board directory and called <soc>-<board>.dts. The binary file 887 is then picked up in board_init_f() and made available through 888 the global data structure as gd->blob. 889 890 CONFIG_OF_SEPARATE 891 If this variable is defined, U-Boot will build a device tree 892 binary. It will be called u-boot.dtb. Architecture-specific 893 code will locate it at run-time. Generally this works by: 894 895 cat u-boot.bin u-boot.dtb >image.bin 896 897 and in fact, U-Boot does this for you, creating a file called 898 u-boot-dtb.bin which is useful in the common case. You can 899 still use the individual files if you need something more 900 exotic. 901 902 CONFIG_OF_BOARD 903 If this variable is defined, U-Boot will use the device tree 904 provided by the board at runtime instead of embedding one with 905 the image. Only boards defining board_fdt_blob_setup() support 906 this option (see include/fdtdec.h file). 907 908- Watchdog: 909 CONFIG_WATCHDOG 910 If this variable is defined, it enables watchdog 911 support for the SoC. There must be support in the SoC 912 specific code for a watchdog. For the 8xx 913 CPUs, the SIU Watchdog feature is enabled in the SYPCR 914 register. When supported for a specific SoC is 915 available, then no further board specific code should 916 be needed to use it. 917 918 CONFIG_HW_WATCHDOG 919 When using a watchdog circuitry external to the used 920 SoC, then define this variable and provide board 921 specific code for the "hw_watchdog_reset" function. 922 923 CONFIG_AT91_HW_WDT_TIMEOUT 924 specify the timeout in seconds. default 2 seconds. 925 926- U-Boot Version: 927 CONFIG_VERSION_VARIABLE 928 If this variable is defined, an environment variable 929 named "ver" is created by U-Boot showing the U-Boot 930 version as printed by the "version" command. 931 Any change to this variable will be reverted at the 932 next reset. 933 934- Real-Time Clock: 935 936 When CONFIG_CMD_DATE is selected, the type of the RTC 937 has to be selected, too. Define exactly one of the 938 following options: 939 940 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 941 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 942 CONFIG_RTC_MC146818 - use MC146818 RTC 943 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 944 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 945 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 946 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 947 CONFIG_RTC_DS164x - use Dallas DS164x RTC 948 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 949 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 950 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 951 CONFIG_SYS_RV3029_TCR - enable trickle charger on 952 RV3029 RTC. 953 954 Note that if the RTC uses I2C, then the I2C interface 955 must also be configured. See I2C Support, below. 956 957- GPIO Support: 958 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 959 960 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 961 chip-ngpio pairs that tell the PCA953X driver the number of 962 pins supported by a particular chip. 963 964 Note that if the GPIO device uses I2C, then the I2C interface 965 must also be configured. See I2C Support, below. 966 967- I/O tracing: 968 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 969 accesses and can checksum them or write a list of them out 970 to memory. See the 'iotrace' command for details. This is 971 useful for testing device drivers since it can confirm that 972 the driver behaves the same way before and after a code 973 change. Currently this is supported on sandbox and arm. To 974 add support for your architecture, add '#include <iotrace.h>' 975 to the bottom of arch/<arch>/include/asm/io.h and test. 976 977 Example output from the 'iotrace stats' command is below. 978 Note that if the trace buffer is exhausted, the checksum will 979 still continue to operate. 980 981 iotrace is enabled 982 Start: 10000000 (buffer start address) 983 Size: 00010000 (buffer size) 984 Offset: 00000120 (current buffer offset) 985 Output: 10000120 (start + offset) 986 Count: 00000018 (number of trace records) 987 CRC32: 9526fb66 (CRC32 of all trace records) 988 989- Timestamp Support: 990 991 When CONFIG_TIMESTAMP is selected, the timestamp 992 (date and time) of an image is printed by image 993 commands like bootm or iminfo. This option is 994 automatically enabled when you select CONFIG_CMD_DATE . 995 996- Partition Labels (disklabels) Supported: 997 Zero or more of the following: 998 CONFIG_MAC_PARTITION Apple's MacOS partition table. 999 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1000 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1001 bootloader. Note 2TB partition limit; see 1002 disk/part_efi.c 1003 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1004 1005 If IDE or SCSI support is enabled (CONFIG_IDE or 1006 CONFIG_SCSI) you must configure support for at 1007 least one non-MTD partition type as well. 1008 1009- IDE Reset method: 1010 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1011 board configurations files but used nowhere! 1012 1013 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1014 be performed by calling the function 1015 ide_set_reset(int reset) 1016 which has to be defined in a board specific file 1017 1018- ATAPI Support: 1019 CONFIG_ATAPI 1020 1021 Set this to enable ATAPI support. 1022 1023- LBA48 Support 1024 CONFIG_LBA48 1025 1026 Set this to enable support for disks larger than 137GB 1027 Also look at CONFIG_SYS_64BIT_LBA. 1028 Whithout these , LBA48 support uses 32bit variables and will 'only' 1029 support disks up to 2.1TB. 1030 1031 CONFIG_SYS_64BIT_LBA: 1032 When enabled, makes the IDE subsystem use 64bit sector addresses. 1033 Default is 32bit. 1034 1035- SCSI Support: 1036 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1037 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1038 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1039 maximum numbers of LUNs, SCSI ID's and target 1040 devices. 1041 1042 The environment variable 'scsidevs' is set to the number of 1043 SCSI devices found during the last scan. 1044 1045- NETWORK Support (PCI): 1046 CONFIG_E1000 1047 Support for Intel 8254x/8257x gigabit chips. 1048 1049 CONFIG_E1000_SPI 1050 Utility code for direct access to the SPI bus on Intel 8257x. 1051 This does not do anything useful unless you set at least one 1052 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1053 1054 CONFIG_E1000_SPI_GENERIC 1055 Allow generic access to the SPI bus on the Intel 8257x, for 1056 example with the "sspi" command. 1057 1058 CONFIG_CMD_E1000 1059 Management command for E1000 devices. When used on devices 1060 with SPI support you can reprogram the EEPROM from U-Boot. 1061 1062 CONFIG_EEPRO100 1063 Support for Intel 82557/82559/82559ER chips. 1064 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1065 write routine for first time initialisation. 1066 1067 CONFIG_TULIP 1068 Support for Digital 2114x chips. 1069 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1070 modem chip initialisation (KS8761/QS6611). 1071 1072 CONFIG_NATSEMI 1073 Support for National dp83815 chips. 1074 1075 CONFIG_NS8382X 1076 Support for National dp8382[01] gigabit chips. 1077 1078- NETWORK Support (other): 1079 1080 CONFIG_DRIVER_AT91EMAC 1081 Support for AT91RM9200 EMAC. 1082 1083 CONFIG_RMII 1084 Define this to use reduced MII inteface 1085 1086 CONFIG_DRIVER_AT91EMAC_QUIET 1087 If this defined, the driver is quiet. 1088 The driver doen't show link status messages. 1089 1090 CONFIG_CALXEDA_XGMAC 1091 Support for the Calxeda XGMAC device 1092 1093 CONFIG_LAN91C96 1094 Support for SMSC's LAN91C96 chips. 1095 1096 CONFIG_LAN91C96_USE_32_BIT 1097 Define this to enable 32 bit addressing 1098 1099 CONFIG_SMC91111 1100 Support for SMSC's LAN91C111 chip 1101 1102 CONFIG_SMC91111_BASE 1103 Define this to hold the physical address 1104 of the device (I/O space) 1105 1106 CONFIG_SMC_USE_32_BIT 1107 Define this if data bus is 32 bits 1108 1109 CONFIG_SMC_USE_IOFUNCS 1110 Define this to use i/o functions instead of macros 1111 (some hardware wont work with macros) 1112 1113 CONFIG_DRIVER_TI_EMAC 1114 Support for davinci emac 1115 1116 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1117 Define this if you have more then 3 PHYs. 1118 1119 CONFIG_FTGMAC100 1120 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1121 1122 CONFIG_FTGMAC100_EGIGA 1123 Define this to use GE link update with gigabit PHY. 1124 Define this if FTGMAC100 is connected to gigabit PHY. 1125 If your system has 10/100 PHY only, it might not occur 1126 wrong behavior. Because PHY usually return timeout or 1127 useless data when polling gigabit status and gigabit 1128 control registers. This behavior won't affect the 1129 correctnessof 10/100 link speed update. 1130 1131 CONFIG_SMC911X 1132 Support for SMSC's LAN911x and LAN921x chips 1133 1134 CONFIG_SMC911X_BASE 1135 Define this to hold the physical address 1136 of the device (I/O space) 1137 1138 CONFIG_SMC911X_32_BIT 1139 Define this if data bus is 32 bits 1140 1141 CONFIG_SMC911X_16_BIT 1142 Define this if data bus is 16 bits. If your processor 1143 automatically converts one 32 bit word to two 16 bit 1144 words you may also try CONFIG_SMC911X_32_BIT. 1145 1146 CONFIG_SH_ETHER 1147 Support for Renesas on-chip Ethernet controller 1148 1149 CONFIG_SH_ETHER_USE_PORT 1150 Define the number of ports to be used 1151 1152 CONFIG_SH_ETHER_PHY_ADDR 1153 Define the ETH PHY's address 1154 1155 CONFIG_SH_ETHER_CACHE_WRITEBACK 1156 If this option is set, the driver enables cache flush. 1157 1158- PWM Support: 1159 CONFIG_PWM_IMX 1160 Support for PWM module on the imx6. 1161 1162- TPM Support: 1163 CONFIG_TPM 1164 Support TPM devices. 1165 1166 CONFIG_TPM_TIS_INFINEON 1167 Support for Infineon i2c bus TPM devices. Only one device 1168 per system is supported at this time. 1169 1170 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1171 Define the burst count bytes upper limit 1172 1173 CONFIG_TPM_ST33ZP24 1174 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1175 1176 CONFIG_TPM_ST33ZP24_I2C 1177 Support for STMicroelectronics ST33ZP24 I2C devices. 1178 Requires TPM_ST33ZP24 and I2C. 1179 1180 CONFIG_TPM_ST33ZP24_SPI 1181 Support for STMicroelectronics ST33ZP24 SPI devices. 1182 Requires TPM_ST33ZP24 and SPI. 1183 1184 CONFIG_TPM_ATMEL_TWI 1185 Support for Atmel TWI TPM device. Requires I2C support. 1186 1187 CONFIG_TPM_TIS_LPC 1188 Support for generic parallel port TPM devices. Only one device 1189 per system is supported at this time. 1190 1191 CONFIG_TPM_TIS_BASE_ADDRESS 1192 Base address where the generic TPM device is mapped 1193 to. Contemporary x86 systems usually map it at 1194 0xfed40000. 1195 1196 CONFIG_CMD_TPM 1197 Add tpm monitor functions. 1198 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1199 provides monitor access to authorized functions. 1200 1201 CONFIG_TPM 1202 Define this to enable the TPM support library which provides 1203 functional interfaces to some TPM commands. 1204 Requires support for a TPM device. 1205 1206 CONFIG_TPM_AUTH_SESSIONS 1207 Define this to enable authorized functions in the TPM library. 1208 Requires CONFIG_TPM and CONFIG_SHA1. 1209 1210- USB Support: 1211 At the moment only the UHCI host controller is 1212 supported (PIP405, MIP405); define 1213 CONFIG_USB_UHCI to enable it. 1214 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1215 and define CONFIG_USB_STORAGE to enable the USB 1216 storage devices. 1217 Note: 1218 Supported are USB Keyboards and USB Floppy drives 1219 (TEAC FD-05PUB). 1220 1221 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1222 txfilltuning field in the EHCI controller on reset. 1223 1224 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1225 HW module registers. 1226 1227- USB Device: 1228 Define the below if you wish to use the USB console. 1229 Once firmware is rebuilt from a serial console issue the 1230 command "setenv stdin usbtty; setenv stdout usbtty" and 1231 attach your USB cable. The Unix command "dmesg" should print 1232 it has found a new device. The environment variable usbtty 1233 can be set to gserial or cdc_acm to enable your device to 1234 appear to a USB host as a Linux gserial device or a 1235 Common Device Class Abstract Control Model serial device. 1236 If you select usbtty = gserial you should be able to enumerate 1237 a Linux host by 1238 # modprobe usbserial vendor=0xVendorID product=0xProductID 1239 else if using cdc_acm, simply setting the environment 1240 variable usbtty to be cdc_acm should suffice. The following 1241 might be defined in YourBoardName.h 1242 1243 CONFIG_USB_DEVICE 1244 Define this to build a UDC device 1245 1246 CONFIG_USB_TTY 1247 Define this to have a tty type of device available to 1248 talk to the UDC device 1249 1250 CONFIG_USBD_HS 1251 Define this to enable the high speed support for usb 1252 device and usbtty. If this feature is enabled, a routine 1253 int is_usbd_high_speed(void) 1254 also needs to be defined by the driver to dynamically poll 1255 whether the enumeration has succeded at high speed or full 1256 speed. 1257 1258 CONFIG_SYS_CONSOLE_IS_IN_ENV 1259 Define this if you want stdin, stdout &/or stderr to 1260 be set to usbtty. 1261 1262 If you have a USB-IF assigned VendorID then you may wish to 1263 define your own vendor specific values either in BoardName.h 1264 or directly in usbd_vendor_info.h. If you don't define 1265 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1266 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1267 should pretend to be a Linux device to it's target host. 1268 1269 CONFIG_USBD_MANUFACTURER 1270 Define this string as the name of your company for 1271 - CONFIG_USBD_MANUFACTURER "my company" 1272 1273 CONFIG_USBD_PRODUCT_NAME 1274 Define this string as the name of your product 1275 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1276 1277 CONFIG_USBD_VENDORID 1278 Define this as your assigned Vendor ID from the USB 1279 Implementors Forum. This *must* be a genuine Vendor ID 1280 to avoid polluting the USB namespace. 1281 - CONFIG_USBD_VENDORID 0xFFFF 1282 1283 CONFIG_USBD_PRODUCTID 1284 Define this as the unique Product ID 1285 for your device 1286 - CONFIG_USBD_PRODUCTID 0xFFFF 1287 1288- ULPI Layer Support: 1289 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1290 the generic ULPI layer. The generic layer accesses the ULPI PHY 1291 via the platform viewport, so you need both the genric layer and 1292 the viewport enabled. Currently only Chipidea/ARC based 1293 viewport is supported. 1294 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1295 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1296 If your ULPI phy needs a different reference clock than the 1297 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1298 the appropriate value in Hz. 1299 1300- MMC Support: 1301 The MMC controller on the Intel PXA is supported. To 1302 enable this define CONFIG_MMC. The MMC can be 1303 accessed from the boot prompt by mapping the device 1304 to physical memory similar to flash. Command line is 1305 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1306 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1307 1308 CONFIG_SH_MMCIF 1309 Support for Renesas on-chip MMCIF controller 1310 1311 CONFIG_SH_MMCIF_ADDR 1312 Define the base address of MMCIF registers 1313 1314 CONFIG_SH_MMCIF_CLK 1315 Define the clock frequency for MMCIF 1316 1317 CONFIG_SUPPORT_EMMC_BOOT 1318 Enable some additional features of the eMMC boot partitions. 1319 1320 CONFIG_SUPPORT_EMMC_RPMB 1321 Enable the commands for reading, writing and programming the 1322 key for the Replay Protection Memory Block partition in eMMC. 1323 1324- USB Device Firmware Update (DFU) class support: 1325 CONFIG_USB_FUNCTION_DFU 1326 This enables the USB portion of the DFU USB class 1327 1328 CONFIG_CMD_DFU 1329 This enables the command "dfu" which is used to have 1330 U-Boot create a DFU class device via USB. This command 1331 requires that the "dfu_alt_info" environment variable be 1332 set and define the alt settings to expose to the host. 1333 1334 CONFIG_DFU_MMC 1335 This enables support for exposing (e)MMC devices via DFU. 1336 1337 CONFIG_DFU_NAND 1338 This enables support for exposing NAND devices via DFU. 1339 1340 CONFIG_DFU_RAM 1341 This enables support for exposing RAM via DFU. 1342 Note: DFU spec refer to non-volatile memory usage, but 1343 allow usages beyond the scope of spec - here RAM usage, 1344 one that would help mostly the developer. 1345 1346 CONFIG_SYS_DFU_DATA_BUF_SIZE 1347 Dfu transfer uses a buffer before writing data to the 1348 raw storage device. Make the size (in bytes) of this buffer 1349 configurable. The size of this buffer is also configurable 1350 through the "dfu_bufsiz" environment variable. 1351 1352 CONFIG_SYS_DFU_MAX_FILE_SIZE 1353 When updating files rather than the raw storage device, 1354 we use a static buffer to copy the file into and then write 1355 the buffer once we've been given the whole file. Define 1356 this to the maximum filesize (in bytes) for the buffer. 1357 Default is 4 MiB if undefined. 1358 1359 DFU_DEFAULT_POLL_TIMEOUT 1360 Poll timeout [ms], is the timeout a device can send to the 1361 host. The host must wait for this timeout before sending 1362 a subsequent DFU_GET_STATUS request to the device. 1363 1364 DFU_MANIFEST_POLL_TIMEOUT 1365 Poll timeout [ms], which the device sends to the host when 1366 entering dfuMANIFEST state. Host waits this timeout, before 1367 sending again an USB request to the device. 1368 1369- USB Device Android Fastboot support: 1370 CONFIG_USB_FUNCTION_FASTBOOT 1371 This enables the USB part of the fastboot gadget 1372 1373 CONFIG_CMD_FASTBOOT 1374 This enables the command "fastboot" which enables the Android 1375 fastboot mode for the platform's USB device. Fastboot is a USB 1376 protocol for downloading images, flashing and device control 1377 used on Android devices. 1378 See doc/README.android-fastboot for more information. 1379 1380 CONFIG_ANDROID_BOOT_IMAGE 1381 This enables support for booting images which use the Android 1382 image format header. 1383 1384 CONFIG_FASTBOOT_BUF_ADDR 1385 The fastboot protocol requires a large memory buffer for 1386 downloads. Define this to the starting RAM address to use for 1387 downloaded images. 1388 1389 CONFIG_FASTBOOT_BUF_SIZE 1390 The fastboot protocol requires a large memory buffer for 1391 downloads. This buffer should be as large as possible for a 1392 platform. Define this to the size available RAM for fastboot. 1393 1394 CONFIG_FASTBOOT_FLASH 1395 The fastboot protocol includes a "flash" command for writing 1396 the downloaded image to a non-volatile storage device. Define 1397 this to enable the "fastboot flash" command. 1398 1399 CONFIG_FASTBOOT_FLASH_MMC_DEV 1400 The fastboot "flash" command requires additional information 1401 regarding the non-volatile storage device. Define this to 1402 the eMMC device that fastboot should use to store the image. 1403 1404 CONFIG_FASTBOOT_GPT_NAME 1405 The fastboot "flash" command supports writing the downloaded 1406 image to the Protective MBR and the Primary GUID Partition 1407 Table. (Additionally, this downloaded image is post-processed 1408 to generate and write the Backup GUID Partition Table.) 1409 This occurs when the specified "partition name" on the 1410 "fastboot flash" command line matches this value. 1411 The default is "gpt" if undefined. 1412 1413 CONFIG_FASTBOOT_MBR_NAME 1414 The fastboot "flash" command supports writing the downloaded 1415 image to DOS MBR. 1416 This occurs when the "partition name" specified on the 1417 "fastboot flash" command line matches this value. 1418 If not defined the default value "mbr" is used. 1419 1420- Journaling Flash filesystem support: 1421 CONFIG_JFFS2_NAND 1422 Define these for a default partition on a NAND device 1423 1424 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1425 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1426 Define these for a default partition on a NOR device 1427 1428- Keyboard Support: 1429 See Kconfig help for available keyboard drivers. 1430 1431 CONFIG_KEYBOARD 1432 1433 Define this to enable a custom keyboard support. 1434 This simply calls drv_keyboard_init() which must be 1435 defined in your board-specific files. This option is deprecated 1436 and is only used by novena. For new boards, use driver model 1437 instead. 1438 1439- Video support: 1440 CONFIG_FSL_DIU_FB 1441 Enable the Freescale DIU video driver. Reference boards for 1442 SOCs that have a DIU should define this macro to enable DIU 1443 support, and should also define these other macros: 1444 1445 CONFIG_SYS_DIU_ADDR 1446 CONFIG_VIDEO 1447 CONFIG_CFB_CONSOLE 1448 CONFIG_VIDEO_SW_CURSOR 1449 CONFIG_VGA_AS_SINGLE_DEVICE 1450 CONFIG_VIDEO_LOGO 1451 CONFIG_VIDEO_BMP_LOGO 1452 1453 The DIU driver will look for the 'video-mode' environment 1454 variable, and if defined, enable the DIU as a console during 1455 boot. See the documentation file doc/README.video for a 1456 description of this variable. 1457 1458- LCD Support: CONFIG_LCD 1459 1460 Define this to enable LCD support (for output to LCD 1461 display); also select one of the supported displays 1462 by defining one of these: 1463 1464 CONFIG_ATMEL_LCD: 1465 1466 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1467 1468 CONFIG_NEC_NL6448AC33: 1469 1470 NEC NL6448AC33-18. Active, color, single scan. 1471 1472 CONFIG_NEC_NL6448BC20 1473 1474 NEC NL6448BC20-08. 6.5", 640x480. 1475 Active, color, single scan. 1476 1477 CONFIG_NEC_NL6448BC33_54 1478 1479 NEC NL6448BC33-54. 10.4", 640x480. 1480 Active, color, single scan. 1481 1482 CONFIG_SHARP_16x9 1483 1484 Sharp 320x240. Active, color, single scan. 1485 It isn't 16x9, and I am not sure what it is. 1486 1487 CONFIG_SHARP_LQ64D341 1488 1489 Sharp LQ64D341 display, 640x480. 1490 Active, color, single scan. 1491 1492 CONFIG_HLD1045 1493 1494 HLD1045 display, 640x480. 1495 Active, color, single scan. 1496 1497 CONFIG_OPTREX_BW 1498 1499 Optrex CBL50840-2 NF-FW 99 22 M5 1500 or 1501 Hitachi LMG6912RPFC-00T 1502 or 1503 Hitachi SP14Q002 1504 1505 320x240. Black & white. 1506 1507 CONFIG_LCD_ALIGNMENT 1508 1509 Normally the LCD is page-aligned (typically 4KB). If this is 1510 defined then the LCD will be aligned to this value instead. 1511 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1512 here, since it is cheaper to change data cache settings on 1513 a per-section basis. 1514 1515 1516 CONFIG_LCD_ROTATION 1517 1518 Sometimes, for example if the display is mounted in portrait 1519 mode or even if it's mounted landscape but rotated by 180degree, 1520 we need to rotate our content of the display relative to the 1521 framebuffer, so that user can read the messages which are 1522 printed out. 1523 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1524 initialized with a given rotation from "vl_rot" out of 1525 "vidinfo_t" which is provided by the board specific code. 1526 The value for vl_rot is coded as following (matching to 1527 fbcon=rotate:<n> linux-kernel commandline): 1528 0 = no rotation respectively 0 degree 1529 1 = 90 degree rotation 1530 2 = 180 degree rotation 1531 3 = 270 degree rotation 1532 1533 If CONFIG_LCD_ROTATION is not defined, the console will be 1534 initialized with 0degree rotation. 1535 1536 CONFIG_LCD_BMP_RLE8 1537 1538 Support drawing of RLE8-compressed bitmaps on the LCD. 1539 1540 CONFIG_I2C_EDID 1541 1542 Enables an 'i2c edid' command which can read EDID 1543 information over I2C from an attached LCD display. 1544 1545- Splash Screen Support: CONFIG_SPLASH_SCREEN 1546 1547 If this option is set, the environment is checked for 1548 a variable "splashimage". If found, the usual display 1549 of logo, copyright and system information on the LCD 1550 is suppressed and the BMP image at the address 1551 specified in "splashimage" is loaded instead. The 1552 console is redirected to the "nulldev", too. This 1553 allows for a "silent" boot where a splash screen is 1554 loaded very quickly after power-on. 1555 1556 CONFIG_SPLASHIMAGE_GUARD 1557 1558 If this option is set, then U-Boot will prevent the environment 1559 variable "splashimage" from being set to a problematic address 1560 (see doc/README.displaying-bmps). 1561 This option is useful for targets where, due to alignment 1562 restrictions, an improperly aligned BMP image will cause a data 1563 abort. If you think you will not have problems with unaligned 1564 accesses (for example because your toolchain prevents them) 1565 there is no need to set this option. 1566 1567 CONFIG_SPLASH_SCREEN_ALIGN 1568 1569 If this option is set the splash image can be freely positioned 1570 on the screen. Environment variable "splashpos" specifies the 1571 position as "x,y". If a positive number is given it is used as 1572 number of pixel from left/top. If a negative number is given it 1573 is used as number of pixel from right/bottom. You can also 1574 specify 'm' for centering the image. 1575 1576 Example: 1577 setenv splashpos m,m 1578 => image at center of screen 1579 1580 setenv splashpos 30,20 1581 => image at x = 30 and y = 20 1582 1583 setenv splashpos -10,m 1584 => vertically centered image 1585 at x = dspWidth - bmpWidth - 9 1586 1587- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1588 1589 If this option is set, additionally to standard BMP 1590 images, gzipped BMP images can be displayed via the 1591 splashscreen support or the bmp command. 1592 1593- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1594 1595 If this option is set, 8-bit RLE compressed BMP images 1596 can be displayed via the splashscreen support or the 1597 bmp command. 1598 1599- Compression support: 1600 CONFIG_GZIP 1601 1602 Enabled by default to support gzip compressed images. 1603 1604 CONFIG_BZIP2 1605 1606 If this option is set, support for bzip2 compressed 1607 images is included. If not, only uncompressed and gzip 1608 compressed images are supported. 1609 1610 NOTE: the bzip2 algorithm requires a lot of RAM, so 1611 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1612 be at least 4MB. 1613 1614- MII/PHY support: 1615 CONFIG_PHY_ADDR 1616 1617 The address of PHY on MII bus. 1618 1619 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1620 1621 The clock frequency of the MII bus 1622 1623 CONFIG_PHY_RESET_DELAY 1624 1625 Some PHY like Intel LXT971A need extra delay after 1626 reset before any MII register access is possible. 1627 For such PHY, set this option to the usec delay 1628 required. (minimum 300usec for LXT971A) 1629 1630 CONFIG_PHY_CMD_DELAY (ppc4xx) 1631 1632 Some PHY like Intel LXT971A need extra delay after 1633 command issued before MII status register can be read 1634 1635- IP address: 1636 CONFIG_IPADDR 1637 1638 Define a default value for the IP address to use for 1639 the default Ethernet interface, in case this is not 1640 determined through e.g. bootp. 1641 (Environment variable "ipaddr") 1642 1643- Server IP address: 1644 CONFIG_SERVERIP 1645 1646 Defines a default value for the IP address of a TFTP 1647 server to contact when using the "tftboot" command. 1648 (Environment variable "serverip") 1649 1650 CONFIG_KEEP_SERVERADDR 1651 1652 Keeps the server's MAC address, in the env 'serveraddr' 1653 for passing to bootargs (like Linux's netconsole option) 1654 1655- Gateway IP address: 1656 CONFIG_GATEWAYIP 1657 1658 Defines a default value for the IP address of the 1659 default router where packets to other networks are 1660 sent to. 1661 (Environment variable "gatewayip") 1662 1663- Subnet mask: 1664 CONFIG_NETMASK 1665 1666 Defines a default value for the subnet mask (or 1667 routing prefix) which is used to determine if an IP 1668 address belongs to the local subnet or needs to be 1669 forwarded through a router. 1670 (Environment variable "netmask") 1671 1672- Multicast TFTP Mode: 1673 CONFIG_MCAST_TFTP 1674 1675 Defines whether you want to support multicast TFTP as per 1676 rfc-2090; for example to work with atftp. Lets lots of targets 1677 tftp down the same boot image concurrently. Note: the Ethernet 1678 driver in use must provide a function: mcast() to join/leave a 1679 multicast group. 1680 1681- BOOTP Recovery Mode: 1682 CONFIG_BOOTP_RANDOM_DELAY 1683 1684 If you have many targets in a network that try to 1685 boot using BOOTP, you may want to avoid that all 1686 systems send out BOOTP requests at precisely the same 1687 moment (which would happen for instance at recovery 1688 from a power failure, when all systems will try to 1689 boot, thus flooding the BOOTP server. Defining 1690 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1691 inserted before sending out BOOTP requests. The 1692 following delays are inserted then: 1693 1694 1st BOOTP request: delay 0 ... 1 sec 1695 2nd BOOTP request: delay 0 ... 2 sec 1696 3rd BOOTP request: delay 0 ... 4 sec 1697 4th and following 1698 BOOTP requests: delay 0 ... 8 sec 1699 1700 CONFIG_BOOTP_ID_CACHE_SIZE 1701 1702 BOOTP packets are uniquely identified using a 32-bit ID. The 1703 server will copy the ID from client requests to responses and 1704 U-Boot will use this to determine if it is the destination of 1705 an incoming response. Some servers will check that addresses 1706 aren't in use before handing them out (usually using an ARP 1707 ping) and therefore take up to a few hundred milliseconds to 1708 respond. Network congestion may also influence the time it 1709 takes for a response to make it back to the client. If that 1710 time is too long, U-Boot will retransmit requests. In order 1711 to allow earlier responses to still be accepted after these 1712 retransmissions, U-Boot's BOOTP client keeps a small cache of 1713 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1714 cache. The default is to keep IDs for up to four outstanding 1715 requests. Increasing this will allow U-Boot to accept offers 1716 from a BOOTP client in networks with unusually high latency. 1717 1718- DHCP Advanced Options: 1719 You can fine tune the DHCP functionality by defining 1720 CONFIG_BOOTP_* symbols: 1721 1722 CONFIG_BOOTP_SUBNETMASK 1723 CONFIG_BOOTP_GATEWAY 1724 CONFIG_BOOTP_HOSTNAME 1725 CONFIG_BOOTP_NISDOMAIN 1726 CONFIG_BOOTP_BOOTPATH 1727 CONFIG_BOOTP_BOOTFILESIZE 1728 CONFIG_BOOTP_DNS 1729 CONFIG_BOOTP_DNS2 1730 CONFIG_BOOTP_SEND_HOSTNAME 1731 CONFIG_BOOTP_NTPSERVER 1732 CONFIG_BOOTP_TIMEOFFSET 1733 CONFIG_BOOTP_VENDOREX 1734 CONFIG_BOOTP_MAY_FAIL 1735 1736 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1737 environment variable, not the BOOTP server. 1738 1739 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1740 after the configured retry count, the call will fail 1741 instead of starting over. This can be used to fail over 1742 to Link-local IP address configuration if the DHCP server 1743 is not available. 1744 1745 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1746 serverip from a DHCP server, it is possible that more 1747 than one DNS serverip is offered to the client. 1748 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1749 serverip will be stored in the additional environment 1750 variable "dnsip2". The first DNS serverip is always 1751 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1752 is defined. 1753 1754 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1755 to do a dynamic update of a DNS server. To do this, they 1756 need the hostname of the DHCP requester. 1757 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1758 of the "hostname" environment variable is passed as 1759 option 12 to the DHCP server. 1760 1761 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1762 1763 A 32bit value in microseconds for a delay between 1764 receiving a "DHCP Offer" and sending the "DHCP Request". 1765 This fixes a problem with certain DHCP servers that don't 1766 respond 100% of the time to a "DHCP request". E.g. On an 1767 AT91RM9200 processor running at 180MHz, this delay needed 1768 to be *at least* 15,000 usec before a Windows Server 2003 1769 DHCP server would reply 100% of the time. I recommend at 1770 least 50,000 usec to be safe. The alternative is to hope 1771 that one of the retries will be successful but note that 1772 the DHCP timeout and retry process takes a longer than 1773 this delay. 1774 1775 - Link-local IP address negotiation: 1776 Negotiate with other link-local clients on the local network 1777 for an address that doesn't require explicit configuration. 1778 This is especially useful if a DHCP server cannot be guaranteed 1779 to exist in all environments that the device must operate. 1780 1781 See doc/README.link-local for more information. 1782 1783 - CDP Options: 1784 CONFIG_CDP_DEVICE_ID 1785 1786 The device id used in CDP trigger frames. 1787 1788 CONFIG_CDP_DEVICE_ID_PREFIX 1789 1790 A two character string which is prefixed to the MAC address 1791 of the device. 1792 1793 CONFIG_CDP_PORT_ID 1794 1795 A printf format string which contains the ascii name of 1796 the port. Normally is set to "eth%d" which sets 1797 eth0 for the first Ethernet, eth1 for the second etc. 1798 1799 CONFIG_CDP_CAPABILITIES 1800 1801 A 32bit integer which indicates the device capabilities; 1802 0x00000010 for a normal host which does not forwards. 1803 1804 CONFIG_CDP_VERSION 1805 1806 An ascii string containing the version of the software. 1807 1808 CONFIG_CDP_PLATFORM 1809 1810 An ascii string containing the name of the platform. 1811 1812 CONFIG_CDP_TRIGGER 1813 1814 A 32bit integer sent on the trigger. 1815 1816 CONFIG_CDP_POWER_CONSUMPTION 1817 1818 A 16bit integer containing the power consumption of the 1819 device in .1 of milliwatts. 1820 1821 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1822 1823 A byte containing the id of the VLAN. 1824 1825- Status LED: CONFIG_LED_STATUS 1826 1827 Several configurations allow to display the current 1828 status using a LED. For instance, the LED will blink 1829 fast while running U-Boot code, stop blinking as 1830 soon as a reply to a BOOTP request was received, and 1831 start blinking slow once the Linux kernel is running 1832 (supported by a status LED driver in the Linux 1833 kernel). Defining CONFIG_LED_STATUS enables this 1834 feature in U-Boot. 1835 1836 Additional options: 1837 1838 CONFIG_LED_STATUS_GPIO 1839 The status LED can be connected to a GPIO pin. 1840 In such cases, the gpio_led driver can be used as a 1841 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1842 to include the gpio_led driver in the U-Boot binary. 1843 1844 CONFIG_GPIO_LED_INVERTED_TABLE 1845 Some GPIO connected LEDs may have inverted polarity in which 1846 case the GPIO high value corresponds to LED off state and 1847 GPIO low value corresponds to LED on state. 1848 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1849 with a list of GPIO LEDs that have inverted polarity. 1850 1851- I2C Support: CONFIG_SYS_I2C 1852 1853 This enable the NEW i2c subsystem, and will allow you to use 1854 i2c commands at the u-boot command line (as long as you set 1855 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1856 based realtime clock chips or other i2c devices. See 1857 common/cmd_i2c.c for a description of the command line 1858 interface. 1859 1860 ported i2c driver to the new framework: 1861 - drivers/i2c/soft_i2c.c: 1862 - activate first bus with CONFIG_SYS_I2C_SOFT define 1863 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1864 for defining speed and slave address 1865 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1866 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1867 for defining speed and slave address 1868 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1869 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1870 for defining speed and slave address 1871 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1872 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1873 for defining speed and slave address 1874 1875 - drivers/i2c/fsl_i2c.c: 1876 - activate i2c driver with CONFIG_SYS_I2C_FSL 1877 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1878 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1879 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1880 bus. 1881 - If your board supports a second fsl i2c bus, define 1882 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1883 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1884 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1885 second bus. 1886 1887 - drivers/i2c/tegra_i2c.c: 1888 - activate this driver with CONFIG_SYS_I2C_TEGRA 1889 - This driver adds 4 i2c buses with a fix speed from 1890 100000 and the slave addr 0! 1891 1892 - drivers/i2c/ppc4xx_i2c.c 1893 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1894 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1895 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1896 1897 - drivers/i2c/i2c_mxc.c 1898 - activate this driver with CONFIG_SYS_I2C_MXC 1899 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1900 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1901 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1902 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1903 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1904 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1905 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1906 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1907 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1908 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1909 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1910 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1911 If those defines are not set, default value is 100000 1912 for speed, and 0 for slave. 1913 1914 - drivers/i2c/rcar_i2c.c: 1915 - activate this driver with CONFIG_SYS_I2C_RCAR 1916 - This driver adds 4 i2c buses 1917 1918 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1919 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1920 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1921 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1922 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1923 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1924 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1925 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1926 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1927 1928 - drivers/i2c/sh_i2c.c: 1929 - activate this driver with CONFIG_SYS_I2C_SH 1930 - This driver adds from 2 to 5 i2c buses 1931 1932 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1933 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1934 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1935 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1936 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1937 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1938 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1939 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1940 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1941 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1942 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1943 1944 - drivers/i2c/omap24xx_i2c.c 1945 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1946 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1947 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1948 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1949 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1950 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1951 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1952 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1953 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1954 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1955 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1956 1957 - drivers/i2c/zynq_i2c.c 1958 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1959 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1960 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1961 1962 - drivers/i2c/s3c24x0_i2c.c: 1963 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1964 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1965 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1966 with a fix speed from 100000 and the slave addr 0! 1967 1968 - drivers/i2c/ihs_i2c.c 1969 - activate this driver with CONFIG_SYS_I2C_IHS 1970 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1971 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1972 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1973 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1974 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1975 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1976 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1977 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1978 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1979 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1980 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1981 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1982 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1983 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1984 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1985 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1986 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1987 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1988 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1989 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1990 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1991 1992 additional defines: 1993 1994 CONFIG_SYS_NUM_I2C_BUSES 1995 Hold the number of i2c buses you want to use. 1996 1997 CONFIG_SYS_I2C_DIRECT_BUS 1998 define this, if you don't use i2c muxes on your hardware. 1999 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2000 omit this define. 2001 2002 CONFIG_SYS_I2C_MAX_HOPS 2003 define how many muxes are maximal consecutively connected 2004 on one i2c bus. If you not use i2c muxes, omit this 2005 define. 2006 2007 CONFIG_SYS_I2C_BUSES 2008 hold a list of buses you want to use, only used if 2009 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2010 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2011 CONFIG_SYS_NUM_I2C_BUSES = 9: 2012 2013 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2014 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2015 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2016 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2017 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2018 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2019 {1, {I2C_NULL_HOP}}, \ 2020 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2021 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2022 } 2023 2024 which defines 2025 bus 0 on adapter 0 without a mux 2026 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2027 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2028 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2029 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2030 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2031 bus 6 on adapter 1 without a mux 2032 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2033 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2034 2035 If you do not have i2c muxes on your board, omit this define. 2036 2037- Legacy I2C Support: 2038 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2039 then the following macros need to be defined (examples are 2040 from include/configs/lwmon.h): 2041 2042 I2C_INIT 2043 2044 (Optional). Any commands necessary to enable the I2C 2045 controller or configure ports. 2046 2047 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2048 2049 I2C_ACTIVE 2050 2051 The code necessary to make the I2C data line active 2052 (driven). If the data line is open collector, this 2053 define can be null. 2054 2055 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2056 2057 I2C_TRISTATE 2058 2059 The code necessary to make the I2C data line tri-stated 2060 (inactive). If the data line is open collector, this 2061 define can be null. 2062 2063 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2064 2065 I2C_READ 2066 2067 Code that returns true if the I2C data line is high, 2068 false if it is low. 2069 2070 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2071 2072 I2C_SDA(bit) 2073 2074 If <bit> is true, sets the I2C data line high. If it 2075 is false, it clears it (low). 2076 2077 eg: #define I2C_SDA(bit) \ 2078 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2079 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2080 2081 I2C_SCL(bit) 2082 2083 If <bit> is true, sets the I2C clock line high. If it 2084 is false, it clears it (low). 2085 2086 eg: #define I2C_SCL(bit) \ 2087 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2088 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2089 2090 I2C_DELAY 2091 2092 This delay is invoked four times per clock cycle so this 2093 controls the rate of data transfer. The data rate thus 2094 is 1 / (I2C_DELAY * 4). Often defined to be something 2095 like: 2096 2097 #define I2C_DELAY udelay(2) 2098 2099 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2100 2101 If your arch supports the generic GPIO framework (asm/gpio.h), 2102 then you may alternatively define the two GPIOs that are to be 2103 used as SCL / SDA. Any of the previous I2C_xxx macros will 2104 have GPIO-based defaults assigned to them as appropriate. 2105 2106 You should define these to the GPIO value as given directly to 2107 the generic GPIO functions. 2108 2109 CONFIG_SYS_I2C_INIT_BOARD 2110 2111 When a board is reset during an i2c bus transfer 2112 chips might think that the current transfer is still 2113 in progress. On some boards it is possible to access 2114 the i2c SCLK line directly, either by using the 2115 processor pin as a GPIO or by having a second pin 2116 connected to the bus. If this option is defined a 2117 custom i2c_init_board() routine in boards/xxx/board.c 2118 is run early in the boot sequence. 2119 2120 CONFIG_I2C_MULTI_BUS 2121 2122 This option allows the use of multiple I2C buses, each of which 2123 must have a controller. At any point in time, only one bus is 2124 active. To switch to a different bus, use the 'i2c dev' command. 2125 Note that bus numbering is zero-based. 2126 2127 CONFIG_SYS_I2C_NOPROBES 2128 2129 This option specifies a list of I2C devices that will be skipped 2130 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2131 is set, specify a list of bus-device pairs. Otherwise, specify 2132 a 1D array of device addresses 2133 2134 e.g. 2135 #undef CONFIG_I2C_MULTI_BUS 2136 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2137 2138 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2139 2140 #define CONFIG_I2C_MULTI_BUS 2141 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2142 2143 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2144 2145 CONFIG_SYS_SPD_BUS_NUM 2146 2147 If defined, then this indicates the I2C bus number for DDR SPD. 2148 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2149 2150 CONFIG_SYS_RTC_BUS_NUM 2151 2152 If defined, then this indicates the I2C bus number for the RTC. 2153 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2154 2155 CONFIG_SOFT_I2C_READ_REPEATED_START 2156 2157 defining this will force the i2c_read() function in 2158 the soft_i2c driver to perform an I2C repeated start 2159 between writing the address pointer and reading the 2160 data. If this define is omitted the default behaviour 2161 of doing a stop-start sequence will be used. Most I2C 2162 devices can use either method, but some require one or 2163 the other. 2164 2165- SPI Support: CONFIG_SPI 2166 2167 Enables SPI driver (so far only tested with 2168 SPI EEPROM, also an instance works with Crystal A/D and 2169 D/As on the SACSng board) 2170 2171 CONFIG_SH_SPI 2172 2173 Enables the driver for SPI controller on SuperH. Currently 2174 only SH7757 is supported. 2175 2176 CONFIG_SOFT_SPI 2177 2178 Enables a software (bit-bang) SPI driver rather than 2179 using hardware support. This is a general purpose 2180 driver that only requires three general I/O port pins 2181 (two outputs, one input) to function. If this is 2182 defined, the board configuration must define several 2183 SPI configuration items (port pins to use, etc). For 2184 an example, see include/configs/sacsng.h. 2185 2186 CONFIG_HARD_SPI 2187 2188 Enables a hardware SPI driver for general-purpose reads 2189 and writes. As with CONFIG_SOFT_SPI, the board configuration 2190 must define a list of chip-select function pointers. 2191 Currently supported on some MPC8xxx processors. For an 2192 example, see include/configs/mpc8349emds.h. 2193 2194 CONFIG_MXC_SPI 2195 2196 Enables the driver for the SPI controllers on i.MX and MXC 2197 SoCs. Currently i.MX31/35/51 are supported. 2198 2199 CONFIG_SYS_SPI_MXC_WAIT 2200 Timeout for waiting until spi transfer completed. 2201 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2202 2203- FPGA Support: CONFIG_FPGA 2204 2205 Enables FPGA subsystem. 2206 2207 CONFIG_FPGA_<vendor> 2208 2209 Enables support for specific chip vendors. 2210 (ALTERA, XILINX) 2211 2212 CONFIG_FPGA_<family> 2213 2214 Enables support for FPGA family. 2215 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2216 2217 CONFIG_FPGA_COUNT 2218 2219 Specify the number of FPGA devices to support. 2220 2221 CONFIG_SYS_FPGA_PROG_FEEDBACK 2222 2223 Enable printing of hash marks during FPGA configuration. 2224 2225 CONFIG_SYS_FPGA_CHECK_BUSY 2226 2227 Enable checks on FPGA configuration interface busy 2228 status by the configuration function. This option 2229 will require a board or device specific function to 2230 be written. 2231 2232 CONFIG_FPGA_DELAY 2233 2234 If defined, a function that provides delays in the FPGA 2235 configuration driver. 2236 2237 CONFIG_SYS_FPGA_CHECK_CTRLC 2238 Allow Control-C to interrupt FPGA configuration 2239 2240 CONFIG_SYS_FPGA_CHECK_ERROR 2241 2242 Check for configuration errors during FPGA bitfile 2243 loading. For example, abort during Virtex II 2244 configuration if the INIT_B line goes low (which 2245 indicated a CRC error). 2246 2247 CONFIG_SYS_FPGA_WAIT_INIT 2248 2249 Maximum time to wait for the INIT_B line to de-assert 2250 after PROB_B has been de-asserted during a Virtex II 2251 FPGA configuration sequence. The default time is 500 2252 ms. 2253 2254 CONFIG_SYS_FPGA_WAIT_BUSY 2255 2256 Maximum time to wait for BUSY to de-assert during 2257 Virtex II FPGA configuration. The default is 5 ms. 2258 2259 CONFIG_SYS_FPGA_WAIT_CONFIG 2260 2261 Time to wait after FPGA configuration. The default is 2262 200 ms. 2263 2264- Configuration Management: 2265 CONFIG_BUILD_TARGET 2266 2267 Some SoCs need special image types (e.g. U-Boot binary 2268 with a special header) as build targets. By defining 2269 CONFIG_BUILD_TARGET in the SoC / board header, this 2270 special image will be automatically built upon calling 2271 make / buildman. 2272 2273 CONFIG_IDENT_STRING 2274 2275 If defined, this string will be added to the U-Boot 2276 version information (U_BOOT_VERSION) 2277 2278- Vendor Parameter Protection: 2279 2280 U-Boot considers the values of the environment 2281 variables "serial#" (Board Serial Number) and 2282 "ethaddr" (Ethernet Address) to be parameters that 2283 are set once by the board vendor / manufacturer, and 2284 protects these variables from casual modification by 2285 the user. Once set, these variables are read-only, 2286 and write or delete attempts are rejected. You can 2287 change this behaviour: 2288 2289 If CONFIG_ENV_OVERWRITE is #defined in your config 2290 file, the write protection for vendor parameters is 2291 completely disabled. Anybody can change or delete 2292 these parameters. 2293 2294 Alternatively, if you define _both_ an ethaddr in the 2295 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2296 Ethernet address is installed in the environment, 2297 which can be changed exactly ONCE by the user. [The 2298 serial# is unaffected by this, i. e. it remains 2299 read-only.] 2300 2301 The same can be accomplished in a more flexible way 2302 for any variable by configuring the type of access 2303 to allow for those variables in the ".flags" variable 2304 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2305 2306- Protected RAM: 2307 CONFIG_PRAM 2308 2309 Define this variable to enable the reservation of 2310 "protected RAM", i. e. RAM which is not overwritten 2311 by U-Boot. Define CONFIG_PRAM to hold the number of 2312 kB you want to reserve for pRAM. You can overwrite 2313 this default value by defining an environment 2314 variable "pram" to the number of kB you want to 2315 reserve. Note that the board info structure will 2316 still show the full amount of RAM. If pRAM is 2317 reserved, a new environment variable "mem" will 2318 automatically be defined to hold the amount of 2319 remaining RAM in a form that can be passed as boot 2320 argument to Linux, for instance like that: 2321 2322 setenv bootargs ... mem=\${mem} 2323 saveenv 2324 2325 This way you can tell Linux not to use this memory, 2326 either, which results in a memory region that will 2327 not be affected by reboots. 2328 2329 *WARNING* If your board configuration uses automatic 2330 detection of the RAM size, you must make sure that 2331 this memory test is non-destructive. So far, the 2332 following board configurations are known to be 2333 "pRAM-clean": 2334 2335 IVMS8, IVML24, SPD8xx, 2336 HERMES, IP860, RPXlite, LWMON, 2337 FLAGADM 2338 2339- Access to physical memory region (> 4GB) 2340 Some basic support is provided for operations on memory not 2341 normally accessible to U-Boot - e.g. some architectures 2342 support access to more than 4GB of memory on 32-bit 2343 machines using physical address extension or similar. 2344 Define CONFIG_PHYSMEM to access this basic support, which 2345 currently only supports clearing the memory. 2346 2347- Error Recovery: 2348 CONFIG_PANIC_HANG 2349 2350 Define this variable to stop the system in case of a 2351 fatal error, so that you have to reset it manually. 2352 This is probably NOT a good idea for an embedded 2353 system where you want the system to reboot 2354 automatically as fast as possible, but it may be 2355 useful during development since you can try to debug 2356 the conditions that lead to the situation. 2357 2358 CONFIG_NET_RETRY_COUNT 2359 2360 This variable defines the number of retries for 2361 network operations like ARP, RARP, TFTP, or BOOTP 2362 before giving up the operation. If not defined, a 2363 default value of 5 is used. 2364 2365 CONFIG_ARP_TIMEOUT 2366 2367 Timeout waiting for an ARP reply in milliseconds. 2368 2369 CONFIG_NFS_TIMEOUT 2370 2371 Timeout in milliseconds used in NFS protocol. 2372 If you encounter "ERROR: Cannot umount" in nfs command, 2373 try longer timeout such as 2374 #define CONFIG_NFS_TIMEOUT 10000UL 2375 2376- Command Interpreter: 2377 CONFIG_AUTO_COMPLETE 2378 2379 Enable auto completion of commands using TAB. 2380 2381 CONFIG_SYS_PROMPT_HUSH_PS2 2382 2383 This defines the secondary prompt string, which is 2384 printed when the command interpreter needs more input 2385 to complete a command. Usually "> ". 2386 2387 Note: 2388 2389 In the current implementation, the local variables 2390 space and global environment variables space are 2391 separated. Local variables are those you define by 2392 simply typing `name=value'. To access a local 2393 variable later on, you have write `$name' or 2394 `${name}'; to execute the contents of a variable 2395 directly type `$name' at the command prompt. 2396 2397 Global environment variables are those you use 2398 setenv/printenv to work with. To run a command stored 2399 in such a variable, you need to use the run command, 2400 and you must not use the '$' sign to access them. 2401 2402 To store commands and special characters in a 2403 variable, please use double quotation marks 2404 surrounding the whole text of the variable, instead 2405 of the backslashes before semicolons and special 2406 symbols. 2407 2408- Command Line Editing and History: 2409 CONFIG_CMDLINE_EDITING 2410 2411 Enable editing and History functions for interactive 2412 command line input operations 2413 2414- Command Line PS1/PS2 support: 2415 CONFIG_CMDLINE_PS_SUPPORT 2416 2417 Enable support for changing the command prompt string 2418 at run-time. Only static string is supported so far. 2419 The string is obtained from environment variables PS1 2420 and PS2. 2421 2422- Default Environment: 2423 CONFIG_EXTRA_ENV_SETTINGS 2424 2425 Define this to contain any number of null terminated 2426 strings (variable = value pairs) that will be part of 2427 the default environment compiled into the boot image. 2428 2429 For example, place something like this in your 2430 board's config file: 2431 2432 #define CONFIG_EXTRA_ENV_SETTINGS \ 2433 "myvar1=value1\0" \ 2434 "myvar2=value2\0" 2435 2436 Warning: This method is based on knowledge about the 2437 internal format how the environment is stored by the 2438 U-Boot code. This is NOT an official, exported 2439 interface! Although it is unlikely that this format 2440 will change soon, there is no guarantee either. 2441 You better know what you are doing here. 2442 2443 Note: overly (ab)use of the default environment is 2444 discouraged. Make sure to check other ways to preset 2445 the environment like the "source" command or the 2446 boot command first. 2447 2448 CONFIG_ENV_VARS_UBOOT_CONFIG 2449 2450 Define this in order to add variables describing the 2451 U-Boot build configuration to the default environment. 2452 These will be named arch, cpu, board, vendor, and soc. 2453 2454 Enabling this option will cause the following to be defined: 2455 2456 - CONFIG_SYS_ARCH 2457 - CONFIG_SYS_CPU 2458 - CONFIG_SYS_BOARD 2459 - CONFIG_SYS_VENDOR 2460 - CONFIG_SYS_SOC 2461 2462 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2463 2464 Define this in order to add variables describing certain 2465 run-time determined information about the hardware to the 2466 environment. These will be named board_name, board_rev. 2467 2468 CONFIG_DELAY_ENVIRONMENT 2469 2470 Normally the environment is loaded when the board is 2471 initialised so that it is available to U-Boot. This inhibits 2472 that so that the environment is not available until 2473 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2474 this is instead controlled by the value of 2475 /config/load-environment. 2476 2477- DataFlash Support: 2478 CONFIG_HAS_DATAFLASH 2479 2480 Defining this option enables DataFlash features and 2481 allows to read/write in Dataflash via the standard 2482 commands cp, md... 2483 2484- Serial Flash support 2485 CONFIG_CMD_SF 2486 2487 Defining this option enables SPI flash commands 2488 'sf probe/read/write/erase/update'. 2489 2490 Usage requires an initial 'probe' to define the serial 2491 flash parameters, followed by read/write/erase/update 2492 commands. 2493 2494 The following defaults may be provided by the platform 2495 to handle the common case when only a single serial 2496 flash is present on the system. 2497 2498 CONFIG_SF_DEFAULT_BUS Bus identifier 2499 CONFIG_SF_DEFAULT_CS Chip-select 2500 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2501 CONFIG_SF_DEFAULT_SPEED in Hz 2502 2503 CONFIG_CMD_SF_TEST 2504 2505 Define this option to include a destructive SPI flash 2506 test ('sf test'). 2507 2508- SystemACE Support: 2509 CONFIG_SYSTEMACE 2510 2511 Adding this option adds support for Xilinx SystemACE 2512 chips attached via some sort of local bus. The address 2513 of the chip must also be defined in the 2514 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2515 2516 #define CONFIG_SYSTEMACE 2517 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2518 2519 When SystemACE support is added, the "ace" device type 2520 becomes available to the fat commands, i.e. fatls. 2521 2522- TFTP Fixed UDP Port: 2523 CONFIG_TFTP_PORT 2524 2525 If this is defined, the environment variable tftpsrcp 2526 is used to supply the TFTP UDP source port value. 2527 If tftpsrcp isn't defined, the normal pseudo-random port 2528 number generator is used. 2529 2530 Also, the environment variable tftpdstp is used to supply 2531 the TFTP UDP destination port value. If tftpdstp isn't 2532 defined, the normal port 69 is used. 2533 2534 The purpose for tftpsrcp is to allow a TFTP server to 2535 blindly start the TFTP transfer using the pre-configured 2536 target IP address and UDP port. This has the effect of 2537 "punching through" the (Windows XP) firewall, allowing 2538 the remainder of the TFTP transfer to proceed normally. 2539 A better solution is to properly configure the firewall, 2540 but sometimes that is not allowed. 2541 2542- bootcount support: 2543 CONFIG_BOOTCOUNT_LIMIT 2544 2545 This enables the bootcounter support, see: 2546 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2547 2548 CONFIG_AT91SAM9XE 2549 enable special bootcounter support on at91sam9xe based boards. 2550 CONFIG_SOC_DA8XX 2551 enable special bootcounter support on da850 based boards. 2552 CONFIG_BOOTCOUNT_RAM 2553 enable support for the bootcounter in RAM 2554 CONFIG_BOOTCOUNT_I2C 2555 enable support for the bootcounter on an i2c (like RTC) device. 2556 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2557 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2558 the bootcounter. 2559 CONFIG_BOOTCOUNT_ALEN = address len 2560 2561- Show boot progress: 2562 CONFIG_SHOW_BOOT_PROGRESS 2563 2564 Defining this option allows to add some board- 2565 specific code (calling a user-provided function 2566 "show_boot_progress(int)") that enables you to show 2567 the system's boot progress on some display (for 2568 example, some LED's) on your board. At the moment, 2569 the following checkpoints are implemented: 2570 2571 2572Legacy uImage format: 2573 2574 Arg Where When 2575 1 common/cmd_bootm.c before attempting to boot an image 2576 -1 common/cmd_bootm.c Image header has bad magic number 2577 2 common/cmd_bootm.c Image header has correct magic number 2578 -2 common/cmd_bootm.c Image header has bad checksum 2579 3 common/cmd_bootm.c Image header has correct checksum 2580 -3 common/cmd_bootm.c Image data has bad checksum 2581 4 common/cmd_bootm.c Image data has correct checksum 2582 -4 common/cmd_bootm.c Image is for unsupported architecture 2583 5 common/cmd_bootm.c Architecture check OK 2584 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2585 6 common/cmd_bootm.c Image Type check OK 2586 -6 common/cmd_bootm.c gunzip uncompression error 2587 -7 common/cmd_bootm.c Unimplemented compression type 2588 7 common/cmd_bootm.c Uncompression OK 2589 8 common/cmd_bootm.c No uncompress/copy overwrite error 2590 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2591 2592 9 common/image.c Start initial ramdisk verification 2593 -10 common/image.c Ramdisk header has bad magic number 2594 -11 common/image.c Ramdisk header has bad checksum 2595 10 common/image.c Ramdisk header is OK 2596 -12 common/image.c Ramdisk data has bad checksum 2597 11 common/image.c Ramdisk data has correct checksum 2598 12 common/image.c Ramdisk verification complete, start loading 2599 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2600 13 common/image.c Start multifile image verification 2601 14 common/image.c No initial ramdisk, no multifile, continue. 2602 2603 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2604 2605 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2606 -31 post/post.c POST test failed, detected by post_output_backlog() 2607 -32 post/post.c POST test failed, detected by post_run_single() 2608 2609 34 common/cmd_doc.c before loading a Image from a DOC device 2610 -35 common/cmd_doc.c Bad usage of "doc" command 2611 35 common/cmd_doc.c correct usage of "doc" command 2612 -36 common/cmd_doc.c No boot device 2613 36 common/cmd_doc.c correct boot device 2614 -37 common/cmd_doc.c Unknown Chip ID on boot device 2615 37 common/cmd_doc.c correct chip ID found, device available 2616 -38 common/cmd_doc.c Read Error on boot device 2617 38 common/cmd_doc.c reading Image header from DOC device OK 2618 -39 common/cmd_doc.c Image header has bad magic number 2619 39 common/cmd_doc.c Image header has correct magic number 2620 -40 common/cmd_doc.c Error reading Image from DOC device 2621 40 common/cmd_doc.c Image header has correct magic number 2622 41 common/cmd_ide.c before loading a Image from a IDE device 2623 -42 common/cmd_ide.c Bad usage of "ide" command 2624 42 common/cmd_ide.c correct usage of "ide" command 2625 -43 common/cmd_ide.c No boot device 2626 43 common/cmd_ide.c boot device found 2627 -44 common/cmd_ide.c Device not available 2628 44 common/cmd_ide.c Device available 2629 -45 common/cmd_ide.c wrong partition selected 2630 45 common/cmd_ide.c partition selected 2631 -46 common/cmd_ide.c Unknown partition table 2632 46 common/cmd_ide.c valid partition table found 2633 -47 common/cmd_ide.c Invalid partition type 2634 47 common/cmd_ide.c correct partition type 2635 -48 common/cmd_ide.c Error reading Image Header on boot device 2636 48 common/cmd_ide.c reading Image Header from IDE device OK 2637 -49 common/cmd_ide.c Image header has bad magic number 2638 49 common/cmd_ide.c Image header has correct magic number 2639 -50 common/cmd_ide.c Image header has bad checksum 2640 50 common/cmd_ide.c Image header has correct checksum 2641 -51 common/cmd_ide.c Error reading Image from IDE device 2642 51 common/cmd_ide.c reading Image from IDE device OK 2643 52 common/cmd_nand.c before loading a Image from a NAND device 2644 -53 common/cmd_nand.c Bad usage of "nand" command 2645 53 common/cmd_nand.c correct usage of "nand" command 2646 -54 common/cmd_nand.c No boot device 2647 54 common/cmd_nand.c boot device found 2648 -55 common/cmd_nand.c Unknown Chip ID on boot device 2649 55 common/cmd_nand.c correct chip ID found, device available 2650 -56 common/cmd_nand.c Error reading Image Header on boot device 2651 56 common/cmd_nand.c reading Image Header from NAND device OK 2652 -57 common/cmd_nand.c Image header has bad magic number 2653 57 common/cmd_nand.c Image header has correct magic number 2654 -58 common/cmd_nand.c Error reading Image from NAND device 2655 58 common/cmd_nand.c reading Image from NAND device OK 2656 2657 -60 common/env_common.c Environment has a bad CRC, using default 2658 2659 64 net/eth.c starting with Ethernet configuration. 2660 -64 net/eth.c no Ethernet found. 2661 65 net/eth.c Ethernet found. 2662 2663 -80 common/cmd_net.c usage wrong 2664 80 common/cmd_net.c before calling net_loop() 2665 -81 common/cmd_net.c some error in net_loop() occurred 2666 81 common/cmd_net.c net_loop() back without error 2667 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2668 82 common/cmd_net.c trying automatic boot 2669 83 common/cmd_net.c running "source" command 2670 -83 common/cmd_net.c some error in automatic boot or "source" command 2671 84 common/cmd_net.c end without errors 2672 2673FIT uImage format: 2674 2675 Arg Where When 2676 100 common/cmd_bootm.c Kernel FIT Image has correct format 2677 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2678 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2679 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2680 102 common/cmd_bootm.c Kernel unit name specified 2681 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2682 103 common/cmd_bootm.c Found configuration node 2683 104 common/cmd_bootm.c Got kernel subimage node offset 2684 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2685 105 common/cmd_bootm.c Kernel subimage hash verification OK 2686 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2687 106 common/cmd_bootm.c Architecture check OK 2688 -106 common/cmd_bootm.c Kernel subimage has wrong type 2689 107 common/cmd_bootm.c Kernel subimage type OK 2690 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2691 108 common/cmd_bootm.c Got kernel subimage data/size 2692 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2693 -109 common/cmd_bootm.c Can't get kernel subimage type 2694 -110 common/cmd_bootm.c Can't get kernel subimage comp 2695 -111 common/cmd_bootm.c Can't get kernel subimage os 2696 -112 common/cmd_bootm.c Can't get kernel subimage load address 2697 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2698 2699 120 common/image.c Start initial ramdisk verification 2700 -120 common/image.c Ramdisk FIT image has incorrect format 2701 121 common/image.c Ramdisk FIT image has correct format 2702 122 common/image.c No ramdisk subimage unit name, using configuration 2703 -122 common/image.c Can't get configuration for ramdisk subimage 2704 123 common/image.c Ramdisk unit name specified 2705 -124 common/image.c Can't get ramdisk subimage node offset 2706 125 common/image.c Got ramdisk subimage node offset 2707 -125 common/image.c Ramdisk subimage hash verification failed 2708 126 common/image.c Ramdisk subimage hash verification OK 2709 -126 common/image.c Ramdisk subimage for unsupported architecture 2710 127 common/image.c Architecture check OK 2711 -127 common/image.c Can't get ramdisk subimage data/size 2712 128 common/image.c Got ramdisk subimage data/size 2713 129 common/image.c Can't get ramdisk load address 2714 -129 common/image.c Got ramdisk load address 2715 2716 -130 common/cmd_doc.c Incorrect FIT image format 2717 131 common/cmd_doc.c FIT image format OK 2718 2719 -140 common/cmd_ide.c Incorrect FIT image format 2720 141 common/cmd_ide.c FIT image format OK 2721 2722 -150 common/cmd_nand.c Incorrect FIT image format 2723 151 common/cmd_nand.c FIT image format OK 2724 2725- legacy image format: 2726 CONFIG_IMAGE_FORMAT_LEGACY 2727 enables the legacy image format support in U-Boot. 2728 2729 Default: 2730 enabled if CONFIG_FIT_SIGNATURE is not defined. 2731 2732 CONFIG_DISABLE_IMAGE_LEGACY 2733 disable the legacy image format 2734 2735 This define is introduced, as the legacy image format is 2736 enabled per default for backward compatibility. 2737 2738- Standalone program support: 2739 CONFIG_STANDALONE_LOAD_ADDR 2740 2741 This option defines a board specific value for the 2742 address where standalone program gets loaded, thus 2743 overwriting the architecture dependent default 2744 settings. 2745 2746- Frame Buffer Address: 2747 CONFIG_FB_ADDR 2748 2749 Define CONFIG_FB_ADDR if you want to use specific 2750 address for frame buffer. This is typically the case 2751 when using a graphics controller has separate video 2752 memory. U-Boot will then place the frame buffer at 2753 the given address instead of dynamically reserving it 2754 in system RAM by calling lcd_setmem(), which grabs 2755 the memory for the frame buffer depending on the 2756 configured panel size. 2757 2758 Please see board_init_f function. 2759 2760- Automatic software updates via TFTP server 2761 CONFIG_UPDATE_TFTP 2762 CONFIG_UPDATE_TFTP_CNT_MAX 2763 CONFIG_UPDATE_TFTP_MSEC_MAX 2764 2765 These options enable and control the auto-update feature; 2766 for a more detailed description refer to doc/README.update. 2767 2768- MTD Support (mtdparts command, UBI support) 2769 CONFIG_MTD_DEVICE 2770 2771 Adds the MTD device infrastructure from the Linux kernel. 2772 Needed for mtdparts command support. 2773 2774 CONFIG_MTD_PARTITIONS 2775 2776 Adds the MTD partitioning infrastructure from the Linux 2777 kernel. Needed for UBI support. 2778 2779- UBI support 2780 CONFIG_UBI_SILENCE_MSG 2781 2782 Make the verbose messages from UBI stop printing. This leaves 2783 warnings and errors enabled. 2784 2785 2786 CONFIG_MTD_UBI_WL_THRESHOLD 2787 This parameter defines the maximum difference between the highest 2788 erase counter value and the lowest erase counter value of eraseblocks 2789 of UBI devices. When this threshold is exceeded, UBI starts performing 2790 wear leveling by means of moving data from eraseblock with low erase 2791 counter to eraseblocks with high erase counter. 2792 2793 The default value should be OK for SLC NAND flashes, NOR flashes and 2794 other flashes which have eraseblock life-cycle 100000 or more. 2795 However, in case of MLC NAND flashes which typically have eraseblock 2796 life-cycle less than 10000, the threshold should be lessened (e.g., 2797 to 128 or 256, although it does not have to be power of 2). 2798 2799 default: 4096 2800 2801 CONFIG_MTD_UBI_BEB_LIMIT 2802 This option specifies the maximum bad physical eraseblocks UBI 2803 expects on the MTD device (per 1024 eraseblocks). If the 2804 underlying flash does not admit of bad eraseblocks (e.g. NOR 2805 flash), this value is ignored. 2806 2807 NAND datasheets often specify the minimum and maximum NVM 2808 (Number of Valid Blocks) for the flashes' endurance lifetime. 2809 The maximum expected bad eraseblocks per 1024 eraseblocks 2810 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2811 which gives 20 for most NANDs (MaxNVB is basically the total 2812 count of eraseblocks on the chip). 2813 2814 To put it differently, if this value is 20, UBI will try to 2815 reserve about 1.9% of physical eraseblocks for bad blocks 2816 handling. And that will be 1.9% of eraseblocks on the entire 2817 NAND chip, not just the MTD partition UBI attaches. This means 2818 that if you have, say, a NAND flash chip admits maximum 40 bad 2819 eraseblocks, and it is split on two MTD partitions of the same 2820 size, UBI will reserve 40 eraseblocks when attaching a 2821 partition. 2822 2823 default: 20 2824 2825 CONFIG_MTD_UBI_FASTMAP 2826 Fastmap is a mechanism which allows attaching an UBI device 2827 in nearly constant time. Instead of scanning the whole MTD device it 2828 only has to locate a checkpoint (called fastmap) on the device. 2829 The on-flash fastmap contains all information needed to attach 2830 the device. Using fastmap makes only sense on large devices where 2831 attaching by scanning takes long. UBI will not automatically install 2832 a fastmap on old images, but you can set the UBI parameter 2833 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2834 that fastmap-enabled images are still usable with UBI implementations 2835 without fastmap support. On typical flash devices the whole fastmap 2836 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2837 2838 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2839 Set this parameter to enable fastmap automatically on images 2840 without a fastmap. 2841 default: 0 2842 2843 CONFIG_MTD_UBI_FM_DEBUG 2844 Enable UBI fastmap debug 2845 default: 0 2846 2847- UBIFS support 2848 CONFIG_UBIFS_SILENCE_MSG 2849 2850 Make the verbose messages from UBIFS stop printing. This leaves 2851 warnings and errors enabled. 2852 2853- SPL framework 2854 CONFIG_SPL 2855 Enable building of SPL globally. 2856 2857 CONFIG_SPL_LDSCRIPT 2858 LDSCRIPT for linking the SPL binary. 2859 2860 CONFIG_SPL_MAX_FOOTPRINT 2861 Maximum size in memory allocated to the SPL, BSS included. 2862 When defined, the linker checks that the actual memory 2863 used by SPL from _start to __bss_end does not exceed it. 2864 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2865 must not be both defined at the same time. 2866 2867 CONFIG_SPL_MAX_SIZE 2868 Maximum size of the SPL image (text, data, rodata, and 2869 linker lists sections), BSS excluded. 2870 When defined, the linker checks that the actual size does 2871 not exceed it. 2872 2873 CONFIG_SPL_TEXT_BASE 2874 TEXT_BASE for linking the SPL binary. 2875 2876 CONFIG_SPL_RELOC_TEXT_BASE 2877 Address to relocate to. If unspecified, this is equal to 2878 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2879 2880 CONFIG_SPL_BSS_START_ADDR 2881 Link address for the BSS within the SPL binary. 2882 2883 CONFIG_SPL_BSS_MAX_SIZE 2884 Maximum size in memory allocated to the SPL BSS. 2885 When defined, the linker checks that the actual memory used 2886 by SPL from __bss_start to __bss_end does not exceed it. 2887 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2888 must not be both defined at the same time. 2889 2890 CONFIG_SPL_STACK 2891 Adress of the start of the stack SPL will use 2892 2893 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2894 When defined, SPL will panic() if the image it has 2895 loaded does not have a signature. 2896 Defining this is useful when code which loads images 2897 in SPL cannot guarantee that absolutely all read errors 2898 will be caught. 2899 An example is the LPC32XX MLC NAND driver, which will 2900 consider that a completely unreadable NAND block is bad, 2901 and thus should be skipped silently. 2902 2903 CONFIG_SPL_RELOC_STACK 2904 Adress of the start of the stack SPL will use after 2905 relocation. If unspecified, this is equal to 2906 CONFIG_SPL_STACK. 2907 2908 CONFIG_SYS_SPL_MALLOC_START 2909 Starting address of the malloc pool used in SPL. 2910 When this option is set the full malloc is used in SPL and 2911 it is set up by spl_init() and before that, the simple malloc() 2912 can be used if CONFIG_SYS_MALLOC_F is defined. 2913 2914 CONFIG_SYS_SPL_MALLOC_SIZE 2915 The size of the malloc pool used in SPL. 2916 2917 CONFIG_SPL_FRAMEWORK 2918 Enable the SPL framework under common/. This framework 2919 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2920 NAND loading of the Linux Kernel. 2921 2922 CONFIG_SPL_OS_BOOT 2923 Enable booting directly to an OS from SPL. 2924 See also: doc/README.falcon 2925 2926 CONFIG_SPL_DISPLAY_PRINT 2927 For ARM, enable an optional function to print more information 2928 about the running system. 2929 2930 CONFIG_SPL_INIT_MINIMAL 2931 Arch init code should be built for a very small image 2932 2933 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2934 Partition on the MMC to load U-Boot from when the MMC is being 2935 used in raw mode 2936 2937 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2938 Sector to load kernel uImage from when MMC is being 2939 used in raw mode (for Falcon mode) 2940 2941 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2942 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2943 Sector and number of sectors to load kernel argument 2944 parameters from when MMC is being used in raw mode 2945 (for falcon mode) 2946 2947 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2948 Partition on the MMC to load U-Boot from when the MMC is being 2949 used in fs mode 2950 2951 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2952 Filename to read to load U-Boot when reading from filesystem 2953 2954 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2955 Filename to read to load kernel uImage when reading 2956 from filesystem (for Falcon mode) 2957 2958 CONFIG_SPL_FS_LOAD_ARGS_NAME 2959 Filename to read to load kernel argument parameters 2960 when reading from filesystem (for Falcon mode) 2961 2962 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2963 Set this for NAND SPL on PPC mpc83xx targets, so that 2964 start.S waits for the rest of the SPL to load before 2965 continuing (the hardware starts execution after just 2966 loading the first page rather than the full 4K). 2967 2968 CONFIG_SPL_SKIP_RELOCATE 2969 Avoid SPL relocation 2970 2971 CONFIG_SPL_NAND_BASE 2972 Include nand_base.c in the SPL. Requires 2973 CONFIG_SPL_NAND_DRIVERS. 2974 2975 CONFIG_SPL_NAND_DRIVERS 2976 SPL uses normal NAND drivers, not minimal drivers. 2977 2978 CONFIG_SPL_NAND_ECC 2979 Include standard software ECC in the SPL 2980 2981 CONFIG_SPL_NAND_SIMPLE 2982 Support for NAND boot using simple NAND drivers that 2983 expose the cmd_ctrl() interface. 2984 2985 CONFIG_SPL_UBI 2986 Support for a lightweight UBI (fastmap) scanner and 2987 loader 2988 2989 CONFIG_SPL_NAND_RAW_ONLY 2990 Support to boot only raw u-boot.bin images. Use this only 2991 if you need to save space. 2992 2993 CONFIG_SPL_COMMON_INIT_DDR 2994 Set for common ddr init with serial presence detect in 2995 SPL binary. 2996 2997 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2998 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2999 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3000 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3001 CONFIG_SYS_NAND_ECCBYTES 3002 Defines the size and behavior of the NAND that SPL uses 3003 to read U-Boot 3004 3005 CONFIG_SPL_NAND_BOOT 3006 Add support NAND boot 3007 3008 CONFIG_SYS_NAND_U_BOOT_OFFS 3009 Location in NAND to read U-Boot from 3010 3011 CONFIG_SYS_NAND_U_BOOT_DST 3012 Location in memory to load U-Boot to 3013 3014 CONFIG_SYS_NAND_U_BOOT_SIZE 3015 Size of image to load 3016 3017 CONFIG_SYS_NAND_U_BOOT_START 3018 Entry point in loaded image to jump to 3019 3020 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3021 Define this if you need to first read the OOB and then the 3022 data. This is used, for example, on davinci platforms. 3023 3024 CONFIG_SPL_OMAP3_ID_NAND 3025 Support for an OMAP3-specific set of functions to return the 3026 ID and MFR of the first attached NAND chip, if present. 3027 3028 CONFIG_SPL_RAM_DEVICE 3029 Support for running image already present in ram, in SPL binary 3030 3031 CONFIG_SPL_PAD_TO 3032 Image offset to which the SPL should be padded before appending 3033 the SPL payload. By default, this is defined as 3034 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3035 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3036 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3037 3038 CONFIG_SPL_TARGET 3039 Final target image containing SPL and payload. Some SPLs 3040 use an arch-specific makefile fragment instead, for 3041 example if more than one image needs to be produced. 3042 3043 CONFIG_FIT_SPL_PRINT 3044 Printing information about a FIT image adds quite a bit of 3045 code to SPL. So this is normally disabled in SPL. Use this 3046 option to re-enable it. This will affect the output of the 3047 bootm command when booting a FIT image. 3048 3049- TPL framework 3050 CONFIG_TPL 3051 Enable building of TPL globally. 3052 3053 CONFIG_TPL_PAD_TO 3054 Image offset to which the TPL should be padded before appending 3055 the TPL payload. By default, this is defined as 3056 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3057 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3058 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3059 3060- Interrupt support (PPC): 3061 3062 There are common interrupt_init() and timer_interrupt() 3063 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3064 for CPU specific initialization. interrupt_init_cpu() 3065 should set decrementer_count to appropriate value. If 3066 CPU resets decrementer automatically after interrupt 3067 (ppc4xx) it should set decrementer_count to zero. 3068 timer_interrupt() calls timer_interrupt_cpu() for CPU 3069 specific handling. If board has watchdog / status_led 3070 / other_activity_monitor it works automatically from 3071 general timer_interrupt(). 3072 3073 3074Board initialization settings: 3075------------------------------ 3076 3077During Initialization u-boot calls a number of board specific functions 3078to allow the preparation of board specific prerequisites, e.g. pin setup 3079before drivers are initialized. To enable these callbacks the 3080following configuration macros have to be defined. Currently this is 3081architecture specific, so please check arch/your_architecture/lib/board.c 3082typically in board_init_f() and board_init_r(). 3083 3084- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3085- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3086- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3087- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3088 3089Configuration Settings: 3090----------------------- 3091 3092- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3093 Optionally it can be defined to support 64-bit memory commands. 3094 3095- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3096 undefine this when you're short of memory. 3097 3098- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3099 width of the commands listed in the 'help' command output. 3100 3101- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3102 prompt for user input. 3103 3104- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3105 3106- CONFIG_SYS_PBSIZE: Buffer size for Console output 3107 3108- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3109 3110- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3111 the application (usually a Linux kernel) when it is 3112 booted 3113 3114- CONFIG_SYS_BAUDRATE_TABLE: 3115 List of legal baudrate settings for this board. 3116 3117- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3118 Begin and End addresses of the area used by the 3119 simple memory test. 3120 3121- CONFIG_SYS_ALT_MEMTEST: 3122 Enable an alternate, more extensive memory test. 3123 3124- CONFIG_SYS_MEMTEST_SCRATCH: 3125 Scratch address used by the alternate memory test 3126 You only need to set this if address zero isn't writeable 3127 3128- CONFIG_SYS_MEM_RESERVE_SECURE 3129 Only implemented for ARMv8 for now. 3130 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3131 is substracted from total RAM and won't be reported to OS. 3132 This memory can be used as secure memory. A variable 3133 gd->arch.secure_ram is used to track the location. In systems 3134 the RAM base is not zero, or RAM is divided into banks, 3135 this variable needs to be recalcuated to get the address. 3136 3137- CONFIG_SYS_MEM_TOP_HIDE: 3138 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3139 this specified memory area will get subtracted from the top 3140 (end) of RAM and won't get "touched" at all by U-Boot. By 3141 fixing up gd->ram_size the Linux kernel should gets passed 3142 the now "corrected" memory size and won't touch it either. 3143 This should work for arch/ppc and arch/powerpc. Only Linux 3144 board ports in arch/powerpc with bootwrapper support that 3145 recalculate the memory size from the SDRAM controller setup 3146 will have to get fixed in Linux additionally. 3147 3148 This option can be used as a workaround for the 440EPx/GRx 3149 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3150 be touched. 3151 3152 WARNING: Please make sure that this value is a multiple of 3153 the Linux page size (normally 4k). If this is not the case, 3154 then the end address of the Linux memory will be located at a 3155 non page size aligned address and this could cause major 3156 problems. 3157 3158- CONFIG_SYS_LOADS_BAUD_CHANGE: 3159 Enable temporary baudrate change while serial download 3160 3161- CONFIG_SYS_SDRAM_BASE: 3162 Physical start address of SDRAM. _Must_ be 0 here. 3163 3164- CONFIG_SYS_FLASH_BASE: 3165 Physical start address of Flash memory. 3166 3167- CONFIG_SYS_MONITOR_BASE: 3168 Physical start address of boot monitor code (set by 3169 make config files to be same as the text base address 3170 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3171 CONFIG_SYS_FLASH_BASE when booting from flash. 3172 3173- CONFIG_SYS_MONITOR_LEN: 3174 Size of memory reserved for monitor code, used to 3175 determine _at_compile_time_ (!) if the environment is 3176 embedded within the U-Boot image, or in a separate 3177 flash sector. 3178 3179- CONFIG_SYS_MALLOC_LEN: 3180 Size of DRAM reserved for malloc() use. 3181 3182- CONFIG_SYS_MALLOC_F_LEN 3183 Size of the malloc() pool for use before relocation. If 3184 this is defined, then a very simple malloc() implementation 3185 will become available before relocation. The address is just 3186 below the global data, and the stack is moved down to make 3187 space. 3188 3189 This feature allocates regions with increasing addresses 3190 within the region. calloc() is supported, but realloc() 3191 is not available. free() is supported but does nothing. 3192 The memory will be freed (or in fact just forgotten) when 3193 U-Boot relocates itself. 3194 3195- CONFIG_SYS_MALLOC_SIMPLE 3196 Provides a simple and small malloc() and calloc() for those 3197 boards which do not use the full malloc in SPL (which is 3198 enabled with CONFIG_SYS_SPL_MALLOC_START). 3199 3200- CONFIG_SYS_NONCACHED_MEMORY: 3201 Size of non-cached memory area. This area of memory will be 3202 typically located right below the malloc() area and mapped 3203 uncached in the MMU. This is useful for drivers that would 3204 otherwise require a lot of explicit cache maintenance. For 3205 some drivers it's also impossible to properly maintain the 3206 cache. For example if the regions that need to be flushed 3207 are not a multiple of the cache-line size, *and* padding 3208 cannot be allocated between the regions to align them (i.e. 3209 if the HW requires a contiguous array of regions, and the 3210 size of each region is not cache-aligned), then a flush of 3211 one region may result in overwriting data that hardware has 3212 written to another region in the same cache-line. This can 3213 happen for example in network drivers where descriptors for 3214 buffers are typically smaller than the CPU cache-line (e.g. 3215 16 bytes vs. 32 or 64 bytes). 3216 3217 Non-cached memory is only supported on 32-bit ARM at present. 3218 3219- CONFIG_SYS_BOOTM_LEN: 3220 Normally compressed uImages are limited to an 3221 uncompressed size of 8 MBytes. If this is not enough, 3222 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3223 to adjust this setting to your needs. 3224 3225- CONFIG_SYS_BOOTMAPSZ: 3226 Maximum size of memory mapped by the startup code of 3227 the Linux kernel; all data that must be processed by 3228 the Linux kernel (bd_info, boot arguments, FDT blob if 3229 used) must be put below this limit, unless "bootm_low" 3230 environment variable is defined and non-zero. In such case 3231 all data for the Linux kernel must be between "bootm_low" 3232 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3233 variable "bootm_mapsize" will override the value of 3234 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3235 then the value in "bootm_size" will be used instead. 3236 3237- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3238 Enable initrd_high functionality. If defined then the 3239 initrd_high feature is enabled and the bootm ramdisk subcommand 3240 is enabled. 3241 3242- CONFIG_SYS_BOOT_GET_CMDLINE: 3243 Enables allocating and saving kernel cmdline in space between 3244 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3245 3246- CONFIG_SYS_BOOT_GET_KBD: 3247 Enables allocating and saving a kernel copy of the bd_info in 3248 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3249 3250- CONFIG_SYS_MAX_FLASH_BANKS: 3251 Max number of Flash memory banks 3252 3253- CONFIG_SYS_MAX_FLASH_SECT: 3254 Max number of sectors on a Flash chip 3255 3256- CONFIG_SYS_FLASH_ERASE_TOUT: 3257 Timeout for Flash erase operations (in ms) 3258 3259- CONFIG_SYS_FLASH_WRITE_TOUT: 3260 Timeout for Flash write operations (in ms) 3261 3262- CONFIG_SYS_FLASH_LOCK_TOUT 3263 Timeout for Flash set sector lock bit operation (in ms) 3264 3265- CONFIG_SYS_FLASH_UNLOCK_TOUT 3266 Timeout for Flash clear lock bits operation (in ms) 3267 3268- CONFIG_SYS_FLASH_PROTECTION 3269 If defined, hardware flash sectors protection is used 3270 instead of U-Boot software protection. 3271 3272- CONFIG_SYS_DIRECT_FLASH_TFTP: 3273 3274 Enable TFTP transfers directly to flash memory; 3275 without this option such a download has to be 3276 performed in two steps: (1) download to RAM, and (2) 3277 copy from RAM to flash. 3278 3279 The two-step approach is usually more reliable, since 3280 you can check if the download worked before you erase 3281 the flash, but in some situations (when system RAM is 3282 too limited to allow for a temporary copy of the 3283 downloaded image) this option may be very useful. 3284 3285- CONFIG_SYS_FLASH_CFI: 3286 Define if the flash driver uses extra elements in the 3287 common flash structure for storing flash geometry. 3288 3289- CONFIG_FLASH_CFI_DRIVER 3290 This option also enables the building of the cfi_flash driver 3291 in the drivers directory 3292 3293- CONFIG_FLASH_CFI_MTD 3294 This option enables the building of the cfi_mtd driver 3295 in the drivers directory. The driver exports CFI flash 3296 to the MTD layer. 3297 3298- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3299 Use buffered writes to flash. 3300 3301- CONFIG_FLASH_SPANSION_S29WS_N 3302 s29ws-n MirrorBit flash has non-standard addresses for buffered 3303 write commands. 3304 3305- CONFIG_SYS_FLASH_QUIET_TEST 3306 If this option is defined, the common CFI flash doesn't 3307 print it's warning upon not recognized FLASH banks. This 3308 is useful, if some of the configured banks are only 3309 optionally available. 3310 3311- CONFIG_FLASH_SHOW_PROGRESS 3312 If defined (must be an integer), print out countdown 3313 digits and dots. Recommended value: 45 (9..1) for 80 3314 column displays, 15 (3..1) for 40 column displays. 3315 3316- CONFIG_FLASH_VERIFY 3317 If defined, the content of the flash (destination) is compared 3318 against the source after the write operation. An error message 3319 will be printed when the contents are not identical. 3320 Please note that this option is useless in nearly all cases, 3321 since such flash programming errors usually are detected earlier 3322 while unprotecting/erasing/programming. Please only enable 3323 this option if you really know what you are doing. 3324 3325- CONFIG_SYS_RX_ETH_BUFFER: 3326 Defines the number of Ethernet receive buffers. On some 3327 Ethernet controllers it is recommended to set this value 3328 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3329 buffers can be full shortly after enabling the interface 3330 on high Ethernet traffic. 3331 Defaults to 4 if not defined. 3332 3333- CONFIG_ENV_MAX_ENTRIES 3334 3335 Maximum number of entries in the hash table that is used 3336 internally to store the environment settings. The default 3337 setting is supposed to be generous and should work in most 3338 cases. This setting can be used to tune behaviour; see 3339 lib/hashtable.c for details. 3340 3341- CONFIG_ENV_FLAGS_LIST_DEFAULT 3342- CONFIG_ENV_FLAGS_LIST_STATIC 3343 Enable validation of the values given to environment variables when 3344 calling env set. Variables can be restricted to only decimal, 3345 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3346 the variables can also be restricted to IP address or MAC address. 3347 3348 The format of the list is: 3349 type_attribute = [s|d|x|b|i|m] 3350 access_attribute = [a|r|o|c] 3351 attributes = type_attribute[access_attribute] 3352 entry = variable_name[:attributes] 3353 list = entry[,list] 3354 3355 The type attributes are: 3356 s - String (default) 3357 d - Decimal 3358 x - Hexadecimal 3359 b - Boolean ([1yYtT|0nNfF]) 3360 i - IP address 3361 m - MAC address 3362 3363 The access attributes are: 3364 a - Any (default) 3365 r - Read-only 3366 o - Write-once 3367 c - Change-default 3368 3369 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3370 Define this to a list (string) to define the ".flags" 3371 environment variable in the default or embedded environment. 3372 3373 - CONFIG_ENV_FLAGS_LIST_STATIC 3374 Define this to a list (string) to define validation that 3375 should be done if an entry is not found in the ".flags" 3376 environment variable. To override a setting in the static 3377 list, simply add an entry for the same variable name to the 3378 ".flags" variable. 3379 3380 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3381 regular expression. This allows multiple variables to define the same 3382 flags without explicitly listing them for each variable. 3383 3384- CONFIG_ENV_ACCESS_IGNORE_FORCE 3385 If defined, don't allow the -f switch to env set override variable 3386 access flags. 3387 3388- CONFIG_USE_STDINT 3389 If stdint.h is available with your toolchain you can define this 3390 option to enable it. You can provide option 'USE_STDINT=1' when 3391 building U-Boot to enable this. 3392 3393The following definitions that deal with the placement and management 3394of environment data (variable area); in general, we support the 3395following configurations: 3396 3397- CONFIG_BUILD_ENVCRC: 3398 3399 Builds up envcrc with the target environment so that external utils 3400 may easily extract it and embed it in final U-Boot images. 3401 3402BE CAREFUL! The first access to the environment happens quite early 3403in U-Boot initialization (when we try to get the setting of for the 3404console baudrate). You *MUST* have mapped your NVRAM area then, or 3405U-Boot will hang. 3406 3407Please note that even with NVRAM we still use a copy of the 3408environment in RAM: we could work on NVRAM directly, but we want to 3409keep settings there always unmodified except somebody uses "saveenv" 3410to save the current settings. 3411 3412BE CAREFUL! For some special cases, the local device can not use 3413"saveenv" command. For example, the local device will get the 3414environment stored in a remote NOR flash by SRIO or PCIE link, 3415but it can not erase, write this NOR flash by SRIO or PCIE interface. 3416 3417- CONFIG_NAND_ENV_DST 3418 3419 Defines address in RAM to which the nand_spl code should copy the 3420 environment. If redundant environment is used, it will be copied to 3421 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3422 3423Please note that the environment is read-only until the monitor 3424has been relocated to RAM and a RAM copy of the environment has been 3425created; also, when using EEPROM you will have to use getenv_f() 3426until then to read environment variables. 3427 3428The environment is protected by a CRC32 checksum. Before the monitor 3429is relocated into RAM, as a result of a bad CRC you will be working 3430with the compiled-in default environment - *silently*!!! [This is 3431necessary, because the first environment variable we need is the 3432"baudrate" setting for the console - if we have a bad CRC, we don't 3433have any device yet where we could complain.] 3434 3435Note: once the monitor has been relocated, then it will complain if 3436the default environment is used; a new CRC is computed as soon as you 3437use the "saveenv" command to store a valid environment. 3438 3439- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3440 Echo the inverted Ethernet link state to the fault LED. 3441 3442 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3443 also needs to be defined. 3444 3445- CONFIG_SYS_FAULT_MII_ADDR: 3446 MII address of the PHY to check for the Ethernet link state. 3447 3448- CONFIG_NS16550_MIN_FUNCTIONS: 3449 Define this if you desire to only have use of the NS16550_init 3450 and NS16550_putc functions for the serial driver located at 3451 drivers/serial/ns16550.c. This option is useful for saving 3452 space for already greatly restricted images, including but not 3453 limited to NAND_SPL configurations. 3454 3455- CONFIG_DISPLAY_BOARDINFO 3456 Display information about the board that U-Boot is running on 3457 when U-Boot starts up. The board function checkboard() is called 3458 to do this. 3459 3460- CONFIG_DISPLAY_BOARDINFO_LATE 3461 Similar to the previous option, but display this information 3462 later, once stdio is running and output goes to the LCD, if 3463 present. 3464 3465- CONFIG_BOARD_SIZE_LIMIT: 3466 Maximum size of the U-Boot image. When defined, the 3467 build system checks that the actual size does not 3468 exceed it. 3469 3470Low Level (hardware related) configuration options: 3471--------------------------------------------------- 3472 3473- CONFIG_SYS_CACHELINE_SIZE: 3474 Cache Line Size of the CPU. 3475 3476- CONFIG_SYS_CCSRBAR_DEFAULT: 3477 Default (power-on reset) physical address of CCSR on Freescale 3478 PowerPC SOCs. 3479 3480- CONFIG_SYS_CCSRBAR: 3481 Virtual address of CCSR. On a 32-bit build, this is typically 3482 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3483 3484- CONFIG_SYS_CCSRBAR_PHYS: 3485 Physical address of CCSR. CCSR can be relocated to a new 3486 physical address, if desired. In this case, this macro should 3487 be set to that address. Otherwise, it should be set to the 3488 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3489 is typically relocated on 36-bit builds. It is recommended 3490 that this macro be defined via the _HIGH and _LOW macros: 3491 3492 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3493 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3494 3495- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3496 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3497 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3498 used in assembly code, so it must not contain typecasts or 3499 integer size suffixes (e.g. "ULL"). 3500 3501- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3502 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3503 used in assembly code, so it must not contain typecasts or 3504 integer size suffixes (e.g. "ULL"). 3505 3506- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3507 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3508 forced to a value that ensures that CCSR is not relocated. 3509 3510- Floppy Disk Support: 3511 CONFIG_SYS_FDC_DRIVE_NUMBER 3512 3513 the default drive number (default value 0) 3514 3515 CONFIG_SYS_ISA_IO_STRIDE 3516 3517 defines the spacing between FDC chipset registers 3518 (default value 1) 3519 3520 CONFIG_SYS_ISA_IO_OFFSET 3521 3522 defines the offset of register from address. It 3523 depends on which part of the data bus is connected to 3524 the FDC chipset. (default value 0) 3525 3526 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3527 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3528 default value. 3529 3530 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3531 fdc_hw_init() is called at the beginning of the FDC 3532 setup. fdc_hw_init() must be provided by the board 3533 source code. It is used to make hardware-dependent 3534 initializations. 3535 3536- CONFIG_IDE_AHB: 3537 Most IDE controllers were designed to be connected with PCI 3538 interface. Only few of them were designed for AHB interface. 3539 When software is doing ATA command and data transfer to 3540 IDE devices through IDE-AHB controller, some additional 3541 registers accessing to these kind of IDE-AHB controller 3542 is required. 3543 3544- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3545 DO NOT CHANGE unless you know exactly what you're 3546 doing! (11-4) [MPC8xx systems only] 3547 3548- CONFIG_SYS_INIT_RAM_ADDR: 3549 3550 Start address of memory area that can be used for 3551 initial data and stack; please note that this must be 3552 writable memory that is working WITHOUT special 3553 initialization, i. e. you CANNOT use normal RAM which 3554 will become available only after programming the 3555 memory controller and running certain initialization 3556 sequences. 3557 3558 U-Boot uses the following memory types: 3559 - MPC8xx: IMMR (internal memory of the CPU) 3560 3561- CONFIG_SYS_GBL_DATA_OFFSET: 3562 3563 Offset of the initial data structure in the memory 3564 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3565 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3566 data is located at the end of the available space 3567 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3568 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3569 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3570 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3571 3572 Note: 3573 On the MPC824X (or other systems that use the data 3574 cache for initial memory) the address chosen for 3575 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3576 point to an otherwise UNUSED address space between 3577 the top of RAM and the start of the PCI space. 3578 3579- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3580 3581- CONFIG_SYS_OR_TIMING_SDRAM: 3582 SDRAM timing 3583 3584- CONFIG_SYS_MAMR_PTA: 3585 periodic timer for refresh 3586 3587- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3588 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3589 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3590 CONFIG_SYS_BR1_PRELIM: 3591 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3592 3593- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3594 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3595 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3596 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3597 3598- CONFIG_PCI_ENUM_ONLY 3599 Only scan through and get the devices on the buses. 3600 Don't do any setup work, presumably because someone or 3601 something has already done it, and we don't need to do it 3602 a second time. Useful for platforms that are pre-booted 3603 by coreboot or similar. 3604 3605- CONFIG_PCI_INDIRECT_BRIDGE: 3606 Enable support for indirect PCI bridges. 3607 3608- CONFIG_SYS_SRIO: 3609 Chip has SRIO or not 3610 3611- CONFIG_SRIO1: 3612 Board has SRIO 1 port available 3613 3614- CONFIG_SRIO2: 3615 Board has SRIO 2 port available 3616 3617- CONFIG_SRIO_PCIE_BOOT_MASTER 3618 Board can support master function for Boot from SRIO and PCIE 3619 3620- CONFIG_SYS_SRIOn_MEM_VIRT: 3621 Virtual Address of SRIO port 'n' memory region 3622 3623- CONFIG_SYS_SRIOn_MEM_PHYS: 3624 Physical Address of SRIO port 'n' memory region 3625 3626- CONFIG_SYS_SRIOn_MEM_SIZE: 3627 Size of SRIO port 'n' memory region 3628 3629- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3630 Defined to tell the NAND controller that the NAND chip is using 3631 a 16 bit bus. 3632 Not all NAND drivers use this symbol. 3633 Example of drivers that use it: 3634 - drivers/mtd/nand/ndfc.c 3635 - drivers/mtd/nand/mxc_nand.c 3636 3637- CONFIG_SYS_NDFC_EBC0_CFG 3638 Sets the EBC0_CFG register for the NDFC. If not defined 3639 a default value will be used. 3640 3641- CONFIG_SPD_EEPROM 3642 Get DDR timing information from an I2C EEPROM. Common 3643 with pluggable memory modules such as SODIMMs 3644 3645 SPD_EEPROM_ADDRESS 3646 I2C address of the SPD EEPROM 3647 3648- CONFIG_SYS_SPD_BUS_NUM 3649 If SPD EEPROM is on an I2C bus other than the first 3650 one, specify here. Note that the value must resolve 3651 to something your driver can deal with. 3652 3653- CONFIG_SYS_DDR_RAW_TIMING 3654 Get DDR timing information from other than SPD. Common with 3655 soldered DDR chips onboard without SPD. DDR raw timing 3656 parameters are extracted from datasheet and hard-coded into 3657 header files or board specific files. 3658 3659- CONFIG_FSL_DDR_INTERACTIVE 3660 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3661 3662- CONFIG_FSL_DDR_SYNC_REFRESH 3663 Enable sync of refresh for multiple controllers. 3664 3665- CONFIG_FSL_DDR_BIST 3666 Enable built-in memory test for Freescale DDR controllers. 3667 3668- CONFIG_SYS_83XX_DDR_USES_CS0 3669 Only for 83xx systems. If specified, then DDR should 3670 be configured using CS0 and CS1 instead of CS2 and CS3. 3671 3672- CONFIG_RMII 3673 Enable RMII mode for all FECs. 3674 Note that this is a global option, we can't 3675 have one FEC in standard MII mode and another in RMII mode. 3676 3677- CONFIG_CRC32_VERIFY 3678 Add a verify option to the crc32 command. 3679 The syntax is: 3680 3681 => crc32 -v <address> <count> <crc32> 3682 3683 Where address/count indicate a memory area 3684 and crc32 is the correct crc32 which the 3685 area should have. 3686 3687- CONFIG_LOOPW 3688 Add the "loopw" memory command. This only takes effect if 3689 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3690 3691- CONFIG_MX_CYCLIC 3692 Add the "mdc" and "mwc" memory commands. These are cyclic 3693 "md/mw" commands. 3694 Examples: 3695 3696 => mdc.b 10 4 500 3697 This command will print 4 bytes (10,11,12,13) each 500 ms. 3698 3699 => mwc.l 100 12345678 10 3700 This command will write 12345678 to address 100 all 10 ms. 3701 3702 This only takes effect if the memory commands are activated 3703 globally (CONFIG_CMD_MEMORY). 3704 3705- CONFIG_SKIP_LOWLEVEL_INIT 3706 [ARM, NDS32, MIPS only] If this variable is defined, then certain 3707 low level initializations (like setting up the memory 3708 controller) are omitted and/or U-Boot does not 3709 relocate itself into RAM. 3710 3711 Normally this variable MUST NOT be defined. The only 3712 exception is when U-Boot is loaded (to RAM) by some 3713 other boot loader or by a debugger which performs 3714 these initializations itself. 3715 3716- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3717 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3718 to be skipped. The normal CP15 init (such as enabling the 3719 instruction cache) is still performed. 3720 3721- CONFIG_SPL_BUILD 3722 Modifies the behaviour of start.S when compiling a loader 3723 that is executed before the actual U-Boot. E.g. when 3724 compiling a NAND SPL. 3725 3726- CONFIG_TPL_BUILD 3727 Modifies the behaviour of start.S when compiling a loader 3728 that is executed after the SPL and before the actual U-Boot. 3729 It is loaded by the SPL. 3730 3731- CONFIG_SYS_MPC85XX_NO_RESETVEC 3732 Only for 85xx systems. If this variable is specified, the section 3733 .resetvec is not kept and the section .bootpg is placed in the 3734 previous 4k of the .text section. 3735 3736- CONFIG_ARCH_MAP_SYSMEM 3737 Generally U-Boot (and in particular the md command) uses 3738 effective address. It is therefore not necessary to regard 3739 U-Boot address as virtual addresses that need to be translated 3740 to physical addresses. However, sandbox requires this, since 3741 it maintains its own little RAM buffer which contains all 3742 addressable memory. This option causes some memory accesses 3743 to be mapped through map_sysmem() / unmap_sysmem(). 3744 3745- CONFIG_X86_RESET_VECTOR 3746 If defined, the x86 reset vector code is included. This is not 3747 needed when U-Boot is running from Coreboot. 3748 3749- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3750 Enables the RTC32K OSC on AM33xx based plattforms 3751 3752- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3753 Option to disable subpage write in NAND driver 3754 driver that uses this: 3755 drivers/mtd/nand/davinci_nand.c 3756 3757Freescale QE/FMAN Firmware Support: 3758----------------------------------- 3759 3760The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3761loading of "firmware", which is encoded in the QE firmware binary format. 3762This firmware often needs to be loaded during U-Boot booting, so macros 3763are used to identify the storage device (NOR flash, SPI, etc) and the address 3764within that device. 3765 3766- CONFIG_SYS_FMAN_FW_ADDR 3767 The address in the storage device where the FMAN microcode is located. The 3768 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3769 is also specified. 3770 3771- CONFIG_SYS_QE_FW_ADDR 3772 The address in the storage device where the QE microcode is located. The 3773 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3774 is also specified. 3775 3776- CONFIG_SYS_QE_FMAN_FW_LENGTH 3777 The maximum possible size of the firmware. The firmware binary format 3778 has a field that specifies the actual size of the firmware, but it 3779 might not be possible to read any part of the firmware unless some 3780 local storage is allocated to hold the entire firmware first. 3781 3782- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3783 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3784 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3785 virtual address in NOR flash. 3786 3787- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3788 Specifies that QE/FMAN firmware is located in NAND flash. 3789 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3790 3791- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3792 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3793 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3794 3795- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3796 Specifies that QE/FMAN firmware is located in the remote (master) 3797 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3798 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3799 window->master inbound window->master LAW->the ucode address in 3800 master's memory space. 3801 3802Freescale Layerscape Management Complex Firmware Support: 3803--------------------------------------------------------- 3804The Freescale Layerscape Management Complex (MC) supports the loading of 3805"firmware". 3806This firmware often needs to be loaded during U-Boot booting, so macros 3807are used to identify the storage device (NOR flash, SPI, etc) and the address 3808within that device. 3809 3810- CONFIG_FSL_MC_ENET 3811 Enable the MC driver for Layerscape SoCs. 3812 3813Freescale Layerscape Debug Server Support: 3814------------------------------------------- 3815The Freescale Layerscape Debug Server Support supports the loading of 3816"Debug Server firmware" and triggering SP boot-rom. 3817This firmware often needs to be loaded during U-Boot booting. 3818 3819- CONFIG_SYS_MC_RSV_MEM_ALIGN 3820 Define alignment of reserved memory MC requires 3821 3822Reproducible builds 3823------------------- 3824 3825In order to achieve reproducible builds, timestamps used in the U-Boot build 3826process have to be set to a fixed value. 3827 3828This is done using the SOURCE_DATE_EPOCH environment variable. 3829SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3830option for U-Boot or an environment variable in U-Boot. 3831 3832SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3833 3834Building the Software: 3835====================== 3836 3837Building U-Boot has been tested in several native build environments 3838and in many different cross environments. Of course we cannot support 3839all possibly existing versions of cross development tools in all 3840(potentially obsolete) versions. In case of tool chain problems we 3841recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3842which is extensively used to build and test U-Boot. 3843 3844If you are not using a native environment, it is assumed that you 3845have GNU cross compiling tools available in your path. In this case, 3846you must set the environment variable CROSS_COMPILE in your shell. 3847Note that no changes to the Makefile or any other source files are 3848necessary. For example using the ELDK on a 4xx CPU, please enter: 3849 3850 $ CROSS_COMPILE=ppc_4xx- 3851 $ export CROSS_COMPILE 3852 3853Note: If you wish to generate Windows versions of the utilities in 3854 the tools directory you can use the MinGW toolchain 3855 (http://www.mingw.org). Set your HOST tools to the MinGW 3856 toolchain and execute 'make tools'. For example: 3857 3858 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3859 3860 Binaries such as tools/mkimage.exe will be created which can 3861 be executed on computers running Windows. 3862 3863U-Boot is intended to be simple to build. After installing the 3864sources you must configure U-Boot for one specific board type. This 3865is done by typing: 3866 3867 make NAME_defconfig 3868 3869where "NAME_defconfig" is the name of one of the existing configu- 3870rations; see boards.cfg for supported names. 3871 3872Note: for some board special configuration names may exist; check if 3873 additional information is available from the board vendor; for 3874 instance, the TQM823L systems are available without (standard) 3875 or with LCD support. You can select such additional "features" 3876 when choosing the configuration, i. e. 3877 3878 make TQM823L_defconfig 3879 - will configure for a plain TQM823L, i. e. no LCD support 3880 3881 make TQM823L_LCD_defconfig 3882 - will configure for a TQM823L with U-Boot console on LCD 3883 3884 etc. 3885 3886 3887Finally, type "make all", and you should get some working U-Boot 3888images ready for download to / installation on your system: 3889 3890- "u-boot.bin" is a raw binary image 3891- "u-boot" is an image in ELF binary format 3892- "u-boot.srec" is in Motorola S-Record format 3893 3894By default the build is performed locally and the objects are saved 3895in the source directory. One of the two methods can be used to change 3896this behavior and build U-Boot to some external directory: 3897 38981. Add O= to the make command line invocations: 3899 3900 make O=/tmp/build distclean 3901 make O=/tmp/build NAME_defconfig 3902 make O=/tmp/build all 3903 39042. Set environment variable KBUILD_OUTPUT to point to the desired location: 3905 3906 export KBUILD_OUTPUT=/tmp/build 3907 make distclean 3908 make NAME_defconfig 3909 make all 3910 3911Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3912variable. 3913 3914 3915Please be aware that the Makefiles assume you are using GNU make, so 3916for instance on NetBSD you might need to use "gmake" instead of 3917native "make". 3918 3919 3920If the system board that you have is not listed, then you will need 3921to port U-Boot to your hardware platform. To do this, follow these 3922steps: 3923 39241. Create a new directory to hold your board specific code. Add any 3925 files you need. In your board directory, you will need at least 3926 the "Makefile" and a "<board>.c". 39272. Create a new configuration file "include/configs/<board>.h" for 3928 your board. 39293. If you're porting U-Boot to a new CPU, then also create a new 3930 directory to hold your CPU specific code. Add any files you need. 39314. Run "make <board>_defconfig" with your new name. 39325. Type "make", and you should get a working "u-boot.srec" file 3933 to be installed on your target system. 39346. Debug and solve any problems that might arise. 3935 [Of course, this last step is much harder than it sounds.] 3936 3937 3938Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3939============================================================== 3940 3941If you have modified U-Boot sources (for instance added a new board 3942or support for new devices, a new CPU, etc.) you are expected to 3943provide feedback to the other developers. The feedback normally takes 3944the form of a "patch", i. e. a context diff against a certain (latest 3945official or latest in the git repository) version of U-Boot sources. 3946 3947But before you submit such a patch, please verify that your modifi- 3948cation did not break existing code. At least make sure that *ALL* of 3949the supported boards compile WITHOUT ANY compiler warnings. To do so, 3950just run the buildman script (tools/buildman/buildman), which will 3951configure and build U-Boot for ALL supported system. Be warned, this 3952will take a while. Please see the buildman README, or run 'buildman -H' 3953for documentation. 3954 3955 3956See also "U-Boot Porting Guide" below. 3957 3958 3959Monitor Commands - Overview: 3960============================ 3961 3962go - start application at address 'addr' 3963run - run commands in an environment variable 3964bootm - boot application image from memory 3965bootp - boot image via network using BootP/TFTP protocol 3966bootz - boot zImage from memory 3967tftpboot- boot image via network using TFTP protocol 3968 and env variables "ipaddr" and "serverip" 3969 (and eventually "gatewayip") 3970tftpput - upload a file via network using TFTP protocol 3971rarpboot- boot image via network using RARP/TFTP protocol 3972diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3973loads - load S-Record file over serial line 3974loadb - load binary file over serial line (kermit mode) 3975md - memory display 3976mm - memory modify (auto-incrementing) 3977nm - memory modify (constant address) 3978mw - memory write (fill) 3979cp - memory copy 3980cmp - memory compare 3981crc32 - checksum calculation 3982i2c - I2C sub-system 3983sspi - SPI utility commands 3984base - print or set address offset 3985printenv- print environment variables 3986setenv - set environment variables 3987saveenv - save environment variables to persistent storage 3988protect - enable or disable FLASH write protection 3989erase - erase FLASH memory 3990flinfo - print FLASH memory information 3991nand - NAND memory operations (see doc/README.nand) 3992bdinfo - print Board Info structure 3993iminfo - print header information for application image 3994coninfo - print console devices and informations 3995ide - IDE sub-system 3996loop - infinite loop on address range 3997loopw - infinite write loop on address range 3998mtest - simple RAM test 3999icache - enable or disable instruction cache 4000dcache - enable or disable data cache 4001reset - Perform RESET of the CPU 4002echo - echo args to console 4003version - print monitor version 4004help - print online help 4005? - alias for 'help' 4006 4007 4008Monitor Commands - Detailed Description: 4009======================================== 4010 4011TODO. 4012 4013For now: just type "help <command>". 4014 4015 4016Environment Variables: 4017====================== 4018 4019U-Boot supports user configuration using Environment Variables which 4020can be made persistent by saving to Flash memory. 4021 4022Environment Variables are set using "setenv", printed using 4023"printenv", and saved to Flash using "saveenv". Using "setenv" 4024without a value can be used to delete a variable from the 4025environment. As long as you don't save the environment you are 4026working with an in-memory copy. In case the Flash area containing the 4027environment is erased by accident, a default environment is provided. 4028 4029Some configuration options can be set using Environment Variables. 4030 4031List of environment variables (most likely not complete): 4032 4033 baudrate - see CONFIG_BAUDRATE 4034 4035 bootdelay - see CONFIG_BOOTDELAY 4036 4037 bootcmd - see CONFIG_BOOTCOMMAND 4038 4039 bootargs - Boot arguments when booting an RTOS image 4040 4041 bootfile - Name of the image to load with TFTP 4042 4043 bootm_low - Memory range available for image processing in the bootm 4044 command can be restricted. This variable is given as 4045 a hexadecimal number and defines lowest address allowed 4046 for use by the bootm command. See also "bootm_size" 4047 environment variable. Address defined by "bootm_low" is 4048 also the base of the initial memory mapping for the Linux 4049 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4050 bootm_mapsize. 4051 4052 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4053 This variable is given as a hexadecimal number and it 4054 defines the size of the memory region starting at base 4055 address bootm_low that is accessible by the Linux kernel 4056 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4057 as the default value if it is defined, and bootm_size is 4058 used otherwise. 4059 4060 bootm_size - Memory range available for image processing in the bootm 4061 command can be restricted. This variable is given as 4062 a hexadecimal number and defines the size of the region 4063 allowed for use by the bootm command. See also "bootm_low" 4064 environment variable. 4065 4066 updatefile - Location of the software update file on a TFTP server, used 4067 by the automatic software update feature. Please refer to 4068 documentation in doc/README.update for more details. 4069 4070 autoload - if set to "no" (any string beginning with 'n'), 4071 "bootp" will just load perform a lookup of the 4072 configuration from the BOOTP server, but not try to 4073 load any image using TFTP 4074 4075 autostart - if set to "yes", an image loaded using the "bootp", 4076 "rarpboot", "tftpboot" or "diskboot" commands will 4077 be automatically started (by internally calling 4078 "bootm") 4079 4080 If set to "no", a standalone image passed to the 4081 "bootm" command will be copied to the load address 4082 (and eventually uncompressed), but NOT be started. 4083 This can be used to load and uncompress arbitrary 4084 data. 4085 4086 fdt_high - if set this restricts the maximum address that the 4087 flattened device tree will be copied into upon boot. 4088 For example, if you have a system with 1 GB memory 4089 at physical address 0x10000000, while Linux kernel 4090 only recognizes the first 704 MB as low memory, you 4091 may need to set fdt_high as 0x3C000000 to have the 4092 device tree blob be copied to the maximum address 4093 of the 704 MB low memory, so that Linux kernel can 4094 access it during the boot procedure. 4095 4096 If this is set to the special value 0xFFFFFFFF then 4097 the fdt will not be copied at all on boot. For this 4098 to work it must reside in writable memory, have 4099 sufficient padding on the end of it for u-boot to 4100 add the information it needs into it, and the memory 4101 must be accessible by the kernel. 4102 4103 fdtcontroladdr- if set this is the address of the control flattened 4104 device tree used by U-Boot when CONFIG_OF_CONTROL is 4105 defined. 4106 4107 i2cfast - (PPC405GP|PPC405EP only) 4108 if set to 'y' configures Linux I2C driver for fast 4109 mode (400kHZ). This environment variable is used in 4110 initialization code. So, for changes to be effective 4111 it must be saved and board must be reset. 4112 4113 initrd_high - restrict positioning of initrd images: 4114 If this variable is not set, initrd images will be 4115 copied to the highest possible address in RAM; this 4116 is usually what you want since it allows for 4117 maximum initrd size. If for some reason you want to 4118 make sure that the initrd image is loaded below the 4119 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4120 variable to a value of "no" or "off" or "0". 4121 Alternatively, you can set it to a maximum upper 4122 address to use (U-Boot will still check that it 4123 does not overwrite the U-Boot stack and data). 4124 4125 For instance, when you have a system with 16 MB 4126 RAM, and want to reserve 4 MB from use by Linux, 4127 you can do this by adding "mem=12M" to the value of 4128 the "bootargs" variable. However, now you must make 4129 sure that the initrd image is placed in the first 4130 12 MB as well - this can be done with 4131 4132 setenv initrd_high 00c00000 4133 4134 If you set initrd_high to 0xFFFFFFFF, this is an 4135 indication to U-Boot that all addresses are legal 4136 for the Linux kernel, including addresses in flash 4137 memory. In this case U-Boot will NOT COPY the 4138 ramdisk at all. This may be useful to reduce the 4139 boot time on your system, but requires that this 4140 feature is supported by your Linux kernel. 4141 4142 ipaddr - IP address; needed for tftpboot command 4143 4144 loadaddr - Default load address for commands like "bootp", 4145 "rarpboot", "tftpboot", "loadb" or "diskboot" 4146 4147 loads_echo - see CONFIG_LOADS_ECHO 4148 4149 serverip - TFTP server IP address; needed for tftpboot command 4150 4151 bootretry - see CONFIG_BOOT_RETRY_TIME 4152 4153 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4154 4155 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4156 4157 ethprime - controls which interface is used first. 4158 4159 ethact - controls which interface is currently active. 4160 For example you can do the following 4161 4162 => setenv ethact FEC 4163 => ping 192.168.0.1 # traffic sent on FEC 4164 => setenv ethact SCC 4165 => ping 10.0.0.1 # traffic sent on SCC 4166 4167 ethrotate - When set to "no" U-Boot does not go through all 4168 available network interfaces. 4169 It just stays at the currently selected interface. 4170 4171 netretry - When set to "no" each network operation will 4172 either succeed or fail without retrying. 4173 When set to "once" the network operation will 4174 fail when all the available network interfaces 4175 are tried once without success. 4176 Useful on scripts which control the retry operation 4177 themselves. 4178 4179 npe_ucode - set load address for the NPE microcode 4180 4181 silent_linux - If set then Linux will be told to boot silently, by 4182 changing the console to be empty. If "yes" it will be 4183 made silent. If "no" it will not be made silent. If 4184 unset, then it will be made silent if the U-Boot console 4185 is silent. 4186 4187 tftpsrcp - If this is set, the value is used for TFTP's 4188 UDP source port. 4189 4190 tftpdstp - If this is set, the value is used for TFTP's UDP 4191 destination port instead of the Well Know Port 69. 4192 4193 tftpblocksize - Block size to use for TFTP transfers; if not set, 4194 we use the TFTP server's default block size 4195 4196 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4197 seconds, minimum value is 1000 = 1 second). Defines 4198 when a packet is considered to be lost so it has to 4199 be retransmitted. The default is 5000 = 5 seconds. 4200 Lowering this value may make downloads succeed 4201 faster in networks with high packet loss rates or 4202 with unreliable TFTP servers. 4203 4204 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4205 unit, minimum value = 0). Defines how many timeouts 4206 can happen during a single file transfer before that 4207 transfer is aborted. The default is 10, and 0 means 4208 'no timeouts allowed'. Increasing this value may help 4209 downloads succeed with high packet loss rates, or with 4210 unreliable TFTP servers or client hardware. 4211 4212 vlan - When set to a value < 4095 the traffic over 4213 Ethernet is encapsulated/received over 802.1q 4214 VLAN tagged frames. 4215 4216 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4217 Unsigned value, in milliseconds. If not set, the period will 4218 be either the default (28000), or a value based on 4219 CONFIG_NET_RETRY_COUNT, if defined. This value has 4220 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4221 4222The following image location variables contain the location of images 4223used in booting. The "Image" column gives the role of the image and is 4224not an environment variable name. The other columns are environment 4225variable names. "File Name" gives the name of the file on a TFTP 4226server, "RAM Address" gives the location in RAM the image will be 4227loaded to, and "Flash Location" gives the image's address in NOR 4228flash or offset in NAND flash. 4229 4230*Note* - these variables don't have to be defined for all boards, some 4231boards currently use other variables for these purposes, and some 4232boards use these variables for other purposes. 4233 4234Image File Name RAM Address Flash Location 4235----- --------- ----------- -------------- 4236u-boot u-boot u-boot_addr_r u-boot_addr 4237Linux kernel bootfile kernel_addr_r kernel_addr 4238device tree blob fdtfile fdt_addr_r fdt_addr 4239ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4240 4241The following environment variables may be used and automatically 4242updated by the network boot commands ("bootp" and "rarpboot"), 4243depending the information provided by your boot server: 4244 4245 bootfile - see above 4246 dnsip - IP address of your Domain Name Server 4247 dnsip2 - IP address of your secondary Domain Name Server 4248 gatewayip - IP address of the Gateway (Router) to use 4249 hostname - Target hostname 4250 ipaddr - see above 4251 netmask - Subnet Mask 4252 rootpath - Pathname of the root filesystem on the NFS server 4253 serverip - see above 4254 4255 4256There are two special Environment Variables: 4257 4258 serial# - contains hardware identification information such 4259 as type string and/or serial number 4260 ethaddr - Ethernet address 4261 4262These variables can be set only once (usually during manufacturing of 4263the board). U-Boot refuses to delete or overwrite these variables 4264once they have been set once. 4265 4266 4267Further special Environment Variables: 4268 4269 ver - Contains the U-Boot version string as printed 4270 with the "version" command. This variable is 4271 readonly (see CONFIG_VERSION_VARIABLE). 4272 4273 4274Please note that changes to some configuration parameters may take 4275only effect after the next boot (yes, that's just like Windoze :-). 4276 4277 4278Callback functions for environment variables: 4279--------------------------------------------- 4280 4281For some environment variables, the behavior of u-boot needs to change 4282when their values are changed. This functionality allows functions to 4283be associated with arbitrary variables. On creation, overwrite, or 4284deletion, the callback will provide the opportunity for some side 4285effect to happen or for the change to be rejected. 4286 4287The callbacks are named and associated with a function using the 4288U_BOOT_ENV_CALLBACK macro in your board or driver code. 4289 4290These callbacks are associated with variables in one of two ways. The 4291static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4292in the board configuration to a string that defines a list of 4293associations. The list must be in the following format: 4294 4295 entry = variable_name[:callback_name] 4296 list = entry[,list] 4297 4298If the callback name is not specified, then the callback is deleted. 4299Spaces are also allowed anywhere in the list. 4300 4301Callbacks can also be associated by defining the ".callbacks" variable 4302with the same list format above. Any association in ".callbacks" will 4303override any association in the static list. You can define 4304CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4305".callbacks" environment variable in the default or embedded environment. 4306 4307If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4308regular expression. This allows multiple variables to be connected to 4309the same callback without explicitly listing them all out. 4310 4311 4312Command Line Parsing: 4313===================== 4314 4315There are two different command line parsers available with U-Boot: 4316the old "simple" one, and the much more powerful "hush" shell: 4317 4318Old, simple command line parser: 4319-------------------------------- 4320 4321- supports environment variables (through setenv / saveenv commands) 4322- several commands on one line, separated by ';' 4323- variable substitution using "... ${name} ..." syntax 4324- special characters ('$', ';') can be escaped by prefixing with '\', 4325 for example: 4326 setenv bootcmd bootm \${address} 4327- You can also escape text by enclosing in single apostrophes, for example: 4328 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4329 4330Hush shell: 4331----------- 4332 4333- similar to Bourne shell, with control structures like 4334 if...then...else...fi, for...do...done; while...do...done, 4335 until...do...done, ... 4336- supports environment ("global") variables (through setenv / saveenv 4337 commands) and local shell variables (through standard shell syntax 4338 "name=value"); only environment variables can be used with "run" 4339 command 4340 4341General rules: 4342-------------- 4343 4344(1) If a command line (or an environment variable executed by a "run" 4345 command) contains several commands separated by semicolon, and 4346 one of these commands fails, then the remaining commands will be 4347 executed anyway. 4348 4349(2) If you execute several variables with one call to run (i. e. 4350 calling run with a list of variables as arguments), any failing 4351 command will cause "run" to terminate, i. e. the remaining 4352 variables are not executed. 4353 4354Note for Redundant Ethernet Interfaces: 4355======================================= 4356 4357Some boards come with redundant Ethernet interfaces; U-Boot supports 4358such configurations and is capable of automatic selection of a 4359"working" interface when needed. MAC assignment works as follows: 4360 4361Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4362MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4363"eth1addr" (=>eth1), "eth2addr", ... 4364 4365If the network interface stores some valid MAC address (for instance 4366in SROM), this is used as default address if there is NO correspon- 4367ding setting in the environment; if the corresponding environment 4368variable is set, this overrides the settings in the card; that means: 4369 4370o If the SROM has a valid MAC address, and there is no address in the 4371 environment, the SROM's address is used. 4372 4373o If there is no valid address in the SROM, and a definition in the 4374 environment exists, then the value from the environment variable is 4375 used. 4376 4377o If both the SROM and the environment contain a MAC address, and 4378 both addresses are the same, this MAC address is used. 4379 4380o If both the SROM and the environment contain a MAC address, and the 4381 addresses differ, the value from the environment is used and a 4382 warning is printed. 4383 4384o If neither SROM nor the environment contain a MAC address, an error 4385 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4386 a random, locally-assigned MAC is used. 4387 4388If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4389will be programmed into hardware as part of the initialization process. This 4390may be skipped by setting the appropriate 'ethmacskip' environment variable. 4391The naming convention is as follows: 4392"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4393 4394Image Formats: 4395============== 4396 4397U-Boot is capable of booting (and performing other auxiliary operations on) 4398images in two formats: 4399 4400New uImage format (FIT) 4401----------------------- 4402 4403Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4404to Flattened Device Tree). It allows the use of images with multiple 4405components (several kernels, ramdisks, etc.), with contents protected by 4406SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4407 4408 4409Old uImage format 4410----------------- 4411 4412Old image format is based on binary files which can be basically anything, 4413preceded by a special header; see the definitions in include/image.h for 4414details; basically, the header defines the following image properties: 4415 4416* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4417 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4418 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4419 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4420 INTEGRITY). 4421* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4422 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4423 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4424* Compression Type (uncompressed, gzip, bzip2) 4425* Load Address 4426* Entry Point 4427* Image Name 4428* Image Timestamp 4429 4430The header is marked by a special Magic Number, and both the header 4431and the data portions of the image are secured against corruption by 4432CRC32 checksums. 4433 4434 4435Linux Support: 4436============== 4437 4438Although U-Boot should support any OS or standalone application 4439easily, the main focus has always been on Linux during the design of 4440U-Boot. 4441 4442U-Boot includes many features that so far have been part of some 4443special "boot loader" code within the Linux kernel. Also, any 4444"initrd" images to be used are no longer part of one big Linux image; 4445instead, kernel and "initrd" are separate images. This implementation 4446serves several purposes: 4447 4448- the same features can be used for other OS or standalone 4449 applications (for instance: using compressed images to reduce the 4450 Flash memory footprint) 4451 4452- it becomes much easier to port new Linux kernel versions because 4453 lots of low-level, hardware dependent stuff are done by U-Boot 4454 4455- the same Linux kernel image can now be used with different "initrd" 4456 images; of course this also means that different kernel images can 4457 be run with the same "initrd". This makes testing easier (you don't 4458 have to build a new "zImage.initrd" Linux image when you just 4459 change a file in your "initrd"). Also, a field-upgrade of the 4460 software is easier now. 4461 4462 4463Linux HOWTO: 4464============ 4465 4466Porting Linux to U-Boot based systems: 4467--------------------------------------- 4468 4469U-Boot cannot save you from doing all the necessary modifications to 4470configure the Linux device drivers for use with your target hardware 4471(no, we don't intend to provide a full virtual machine interface to 4472Linux :-). 4473 4474But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4475 4476Just make sure your machine specific header file (for instance 4477include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4478Information structure as we define in include/asm-<arch>/u-boot.h, 4479and make sure that your definition of IMAP_ADDR uses the same value 4480as your U-Boot configuration in CONFIG_SYS_IMMR. 4481 4482Note that U-Boot now has a driver model, a unified model for drivers. 4483If you are adding a new driver, plumb it into driver model. If there 4484is no uclass available, you are encouraged to create one. See 4485doc/driver-model. 4486 4487 4488Configuring the Linux kernel: 4489----------------------------- 4490 4491No specific requirements for U-Boot. Make sure you have some root 4492device (initial ramdisk, NFS) for your target system. 4493 4494 4495Building a Linux Image: 4496----------------------- 4497 4498With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4499not used. If you use recent kernel source, a new build target 4500"uImage" will exist which automatically builds an image usable by 4501U-Boot. Most older kernels also have support for a "pImage" target, 4502which was introduced for our predecessor project PPCBoot and uses a 4503100% compatible format. 4504 4505Example: 4506 4507 make TQM850L_defconfig 4508 make oldconfig 4509 make dep 4510 make uImage 4511 4512The "uImage" build target uses a special tool (in 'tools/mkimage') to 4513encapsulate a compressed Linux kernel image with header information, 4514CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4515 4516* build a standard "vmlinux" kernel image (in ELF binary format): 4517 4518* convert the kernel into a raw binary image: 4519 4520 ${CROSS_COMPILE}-objcopy -O binary \ 4521 -R .note -R .comment \ 4522 -S vmlinux linux.bin 4523 4524* compress the binary image: 4525 4526 gzip -9 linux.bin 4527 4528* package compressed binary image for U-Boot: 4529 4530 mkimage -A ppc -O linux -T kernel -C gzip \ 4531 -a 0 -e 0 -n "Linux Kernel Image" \ 4532 -d linux.bin.gz uImage 4533 4534 4535The "mkimage" tool can also be used to create ramdisk images for use 4536with U-Boot, either separated from the Linux kernel image, or 4537combined into one file. "mkimage" encapsulates the images with a 64 4538byte header containing information about target architecture, 4539operating system, image type, compression method, entry points, time 4540stamp, CRC32 checksums, etc. 4541 4542"mkimage" can be called in two ways: to verify existing images and 4543print the header information, or to build new images. 4544 4545In the first form (with "-l" option) mkimage lists the information 4546contained in the header of an existing U-Boot image; this includes 4547checksum verification: 4548 4549 tools/mkimage -l image 4550 -l ==> list image header information 4551 4552The second form (with "-d" option) is used to build a U-Boot image 4553from a "data file" which is used as image payload: 4554 4555 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4556 -n name -d data_file image 4557 -A ==> set architecture to 'arch' 4558 -O ==> set operating system to 'os' 4559 -T ==> set image type to 'type' 4560 -C ==> set compression type 'comp' 4561 -a ==> set load address to 'addr' (hex) 4562 -e ==> set entry point to 'ep' (hex) 4563 -n ==> set image name to 'name' 4564 -d ==> use image data from 'datafile' 4565 4566Right now, all Linux kernels for PowerPC systems use the same load 4567address (0x00000000), but the entry point address depends on the 4568kernel version: 4569 4570- 2.2.x kernels have the entry point at 0x0000000C, 4571- 2.3.x and later kernels have the entry point at 0x00000000. 4572 4573So a typical call to build a U-Boot image would read: 4574 4575 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4576 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4577 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4578 > examples/uImage.TQM850L 4579 Image Name: 2.4.4 kernel for TQM850L 4580 Created: Wed Jul 19 02:34:59 2000 4581 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4582 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4583 Load Address: 0x00000000 4584 Entry Point: 0x00000000 4585 4586To verify the contents of the image (or check for corruption): 4587 4588 -> tools/mkimage -l examples/uImage.TQM850L 4589 Image Name: 2.4.4 kernel for TQM850L 4590 Created: Wed Jul 19 02:34:59 2000 4591 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4592 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4593 Load Address: 0x00000000 4594 Entry Point: 0x00000000 4595 4596NOTE: for embedded systems where boot time is critical you can trade 4597speed for memory and install an UNCOMPRESSED image instead: this 4598needs more space in Flash, but boots much faster since it does not 4599need to be uncompressed: 4600 4601 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4602 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4603 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4604 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4605 > examples/uImage.TQM850L-uncompressed 4606 Image Name: 2.4.4 kernel for TQM850L 4607 Created: Wed Jul 19 02:34:59 2000 4608 Image Type: PowerPC Linux Kernel Image (uncompressed) 4609 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4610 Load Address: 0x00000000 4611 Entry Point: 0x00000000 4612 4613 4614Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4615when your kernel is intended to use an initial ramdisk: 4616 4617 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4618 > -A ppc -O linux -T ramdisk -C gzip \ 4619 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4620 Image Name: Simple Ramdisk Image 4621 Created: Wed Jan 12 14:01:50 2000 4622 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4623 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4624 Load Address: 0x00000000 4625 Entry Point: 0x00000000 4626 4627The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4628option performs the converse operation of the mkimage's second form (the "-d" 4629option). Given an image built by mkimage, the dumpimage extracts a "data file" 4630from the image: 4631 4632 tools/dumpimage -i image -T type -p position data_file 4633 -i ==> extract from the 'image' a specific 'data_file' 4634 -T ==> set image type to 'type' 4635 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4636 4637 4638Installing a Linux Image: 4639------------------------- 4640 4641To downloading a U-Boot image over the serial (console) interface, 4642you must convert the image to S-Record format: 4643 4644 objcopy -I binary -O srec examples/image examples/image.srec 4645 4646The 'objcopy' does not understand the information in the U-Boot 4647image header, so the resulting S-Record file will be relative to 4648address 0x00000000. To load it to a given address, you need to 4649specify the target address as 'offset' parameter with the 'loads' 4650command. 4651 4652Example: install the image to address 0x40100000 (which on the 4653TQM8xxL is in the first Flash bank): 4654 4655 => erase 40100000 401FFFFF 4656 4657 .......... done 4658 Erased 8 sectors 4659 4660 => loads 40100000 4661 ## Ready for S-Record download ... 4662 ~>examples/image.srec 4663 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4664 ... 4665 15989 15990 15991 15992 4666 [file transfer complete] 4667 [connected] 4668 ## Start Addr = 0x00000000 4669 4670 4671You can check the success of the download using the 'iminfo' command; 4672this includes a checksum verification so you can be sure no data 4673corruption happened: 4674 4675 => imi 40100000 4676 4677 ## Checking Image at 40100000 ... 4678 Image Name: 2.2.13 for initrd on TQM850L 4679 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4680 Data Size: 335725 Bytes = 327 kB = 0 MB 4681 Load Address: 00000000 4682 Entry Point: 0000000c 4683 Verifying Checksum ... OK 4684 4685 4686Boot Linux: 4687----------- 4688 4689The "bootm" command is used to boot an application that is stored in 4690memory (RAM or Flash). In case of a Linux kernel image, the contents 4691of the "bootargs" environment variable is passed to the kernel as 4692parameters. You can check and modify this variable using the 4693"printenv" and "setenv" commands: 4694 4695 4696 => printenv bootargs 4697 bootargs=root=/dev/ram 4698 4699 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4700 4701 => printenv bootargs 4702 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4703 4704 => bootm 40020000 4705 ## Booting Linux kernel at 40020000 ... 4706 Image Name: 2.2.13 for NFS on TQM850L 4707 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4708 Data Size: 381681 Bytes = 372 kB = 0 MB 4709 Load Address: 00000000 4710 Entry Point: 0000000c 4711 Verifying Checksum ... OK 4712 Uncompressing Kernel Image ... OK 4713 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 4714 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4715 time_init: decrementer frequency = 187500000/60 4716 Calibrating delay loop... 49.77 BogoMIPS 4717 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4718 ... 4719 4720If you want to boot a Linux kernel with initial RAM disk, you pass 4721the memory addresses of both the kernel and the initrd image (PPBCOOT 4722format!) to the "bootm" command: 4723 4724 => imi 40100000 40200000 4725 4726 ## Checking Image at 40100000 ... 4727 Image Name: 2.2.13 for initrd on TQM850L 4728 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4729 Data Size: 335725 Bytes = 327 kB = 0 MB 4730 Load Address: 00000000 4731 Entry Point: 0000000c 4732 Verifying Checksum ... OK 4733 4734 ## Checking Image at 40200000 ... 4735 Image Name: Simple Ramdisk Image 4736 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4737 Data Size: 566530 Bytes = 553 kB = 0 MB 4738 Load Address: 00000000 4739 Entry Point: 00000000 4740 Verifying Checksum ... OK 4741 4742 => bootm 40100000 40200000 4743 ## Booting Linux kernel at 40100000 ... 4744 Image Name: 2.2.13 for initrd on TQM850L 4745 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4746 Data Size: 335725 Bytes = 327 kB = 0 MB 4747 Load Address: 00000000 4748 Entry Point: 0000000c 4749 Verifying Checksum ... OK 4750 Uncompressing Kernel Image ... OK 4751 ## Loading RAMDisk Image at 40200000 ... 4752 Image Name: Simple Ramdisk Image 4753 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4754 Data Size: 566530 Bytes = 553 kB = 0 MB 4755 Load Address: 00000000 4756 Entry Point: 00000000 4757 Verifying Checksum ... OK 4758 Loading Ramdisk ... OK 4759 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 4760 Boot arguments: root=/dev/ram 4761 time_init: decrementer frequency = 187500000/60 4762 Calibrating delay loop... 49.77 BogoMIPS 4763 ... 4764 RAMDISK: Compressed image found at block 0 4765 VFS: Mounted root (ext2 filesystem). 4766 4767 bash# 4768 4769Boot Linux and pass a flat device tree: 4770----------- 4771 4772First, U-Boot must be compiled with the appropriate defines. See the section 4773titled "Linux Kernel Interface" above for a more in depth explanation. The 4774following is an example of how to start a kernel and pass an updated 4775flat device tree: 4776 4777=> print oftaddr 4778oftaddr=0x300000 4779=> print oft 4780oft=oftrees/mpc8540ads.dtb 4781=> tftp $oftaddr $oft 4782Speed: 1000, full duplex 4783Using TSEC0 device 4784TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4785Filename 'oftrees/mpc8540ads.dtb'. 4786Load address: 0x300000 4787Loading: # 4788done 4789Bytes transferred = 4106 (100a hex) 4790=> tftp $loadaddr $bootfile 4791Speed: 1000, full duplex 4792Using TSEC0 device 4793TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4794Filename 'uImage'. 4795Load address: 0x200000 4796Loading:############ 4797done 4798Bytes transferred = 1029407 (fb51f hex) 4799=> print loadaddr 4800loadaddr=200000 4801=> print oftaddr 4802oftaddr=0x300000 4803=> bootm $loadaddr - $oftaddr 4804## Booting image at 00200000 ... 4805 Image Name: Linux-2.6.17-dirty 4806 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4807 Data Size: 1029343 Bytes = 1005.2 kB 4808 Load Address: 00000000 4809 Entry Point: 00000000 4810 Verifying Checksum ... OK 4811 Uncompressing Kernel Image ... OK 4812Booting using flat device tree at 0x300000 4813Using MPC85xx ADS machine description 4814Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4815[snip] 4816 4817 4818More About U-Boot Image Types: 4819------------------------------ 4820 4821U-Boot supports the following image types: 4822 4823 "Standalone Programs" are directly runnable in the environment 4824 provided by U-Boot; it is expected that (if they behave 4825 well) you can continue to work in U-Boot after return from 4826 the Standalone Program. 4827 "OS Kernel Images" are usually images of some Embedded OS which 4828 will take over control completely. Usually these programs 4829 will install their own set of exception handlers, device 4830 drivers, set up the MMU, etc. - this means, that you cannot 4831 expect to re-enter U-Boot except by resetting the CPU. 4832 "RAMDisk Images" are more or less just data blocks, and their 4833 parameters (address, size) are passed to an OS kernel that is 4834 being started. 4835 "Multi-File Images" contain several images, typically an OS 4836 (Linux) kernel image and one or more data images like 4837 RAMDisks. This construct is useful for instance when you want 4838 to boot over the network using BOOTP etc., where the boot 4839 server provides just a single image file, but you want to get 4840 for instance an OS kernel and a RAMDisk image. 4841 4842 "Multi-File Images" start with a list of image sizes, each 4843 image size (in bytes) specified by an "uint32_t" in network 4844 byte order. This list is terminated by an "(uint32_t)0". 4845 Immediately after the terminating 0 follow the images, one by 4846 one, all aligned on "uint32_t" boundaries (size rounded up to 4847 a multiple of 4 bytes). 4848 4849 "Firmware Images" are binary images containing firmware (like 4850 U-Boot or FPGA images) which usually will be programmed to 4851 flash memory. 4852 4853 "Script files" are command sequences that will be executed by 4854 U-Boot's command interpreter; this feature is especially 4855 useful when you configure U-Boot to use a real shell (hush) 4856 as command interpreter. 4857 4858Booting the Linux zImage: 4859------------------------- 4860 4861On some platforms, it's possible to boot Linux zImage. This is done 4862using the "bootz" command. The syntax of "bootz" command is the same 4863as the syntax of "bootm" command. 4864 4865Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4866kernel with raw initrd images. The syntax is slightly different, the 4867address of the initrd must be augmented by it's size, in the following 4868format: "<initrd addres>:<initrd size>". 4869 4870 4871Standalone HOWTO: 4872================= 4873 4874One of the features of U-Boot is that you can dynamically load and 4875run "standalone" applications, which can use some resources of 4876U-Boot like console I/O functions or interrupt services. 4877 4878Two simple examples are included with the sources: 4879 4880"Hello World" Demo: 4881------------------- 4882 4883'examples/hello_world.c' contains a small "Hello World" Demo 4884application; it is automatically compiled when you build U-Boot. 4885It's configured to run at address 0x00040004, so you can play with it 4886like that: 4887 4888 => loads 4889 ## Ready for S-Record download ... 4890 ~>examples/hello_world.srec 4891 1 2 3 4 5 6 7 8 9 10 11 ... 4892 [file transfer complete] 4893 [connected] 4894 ## Start Addr = 0x00040004 4895 4896 => go 40004 Hello World! This is a test. 4897 ## Starting application at 0x00040004 ... 4898 Hello World 4899 argc = 7 4900 argv[0] = "40004" 4901 argv[1] = "Hello" 4902 argv[2] = "World!" 4903 argv[3] = "This" 4904 argv[4] = "is" 4905 argv[5] = "a" 4906 argv[6] = "test." 4907 argv[7] = "<NULL>" 4908 Hit any key to exit ... 4909 4910 ## Application terminated, rc = 0x0 4911 4912Another example, which demonstrates how to register a CPM interrupt 4913handler with the U-Boot code, can be found in 'examples/timer.c'. 4914Here, a CPM timer is set up to generate an interrupt every second. 4915The interrupt service routine is trivial, just printing a '.' 4916character, but this is just a demo program. The application can be 4917controlled by the following keys: 4918 4919 ? - print current values og the CPM Timer registers 4920 b - enable interrupts and start timer 4921 e - stop timer and disable interrupts 4922 q - quit application 4923 4924 => loads 4925 ## Ready for S-Record download ... 4926 ~>examples/timer.srec 4927 1 2 3 4 5 6 7 8 9 10 11 ... 4928 [file transfer complete] 4929 [connected] 4930 ## Start Addr = 0x00040004 4931 4932 => go 40004 4933 ## Starting application at 0x00040004 ... 4934 TIMERS=0xfff00980 4935 Using timer 1 4936 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4937 4938Hit 'b': 4939 [q, b, e, ?] Set interval 1000000 us 4940 Enabling timer 4941Hit '?': 4942 [q, b, e, ?] ........ 4943 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4944Hit '?': 4945 [q, b, e, ?] . 4946 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4947Hit '?': 4948 [q, b, e, ?] . 4949 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4950Hit '?': 4951 [q, b, e, ?] . 4952 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4953Hit 'e': 4954 [q, b, e, ?] ...Stopping timer 4955Hit 'q': 4956 [q, b, e, ?] ## Application terminated, rc = 0x0 4957 4958 4959Minicom warning: 4960================ 4961 4962Over time, many people have reported problems when trying to use the 4963"minicom" terminal emulation program for serial download. I (wd) 4964consider minicom to be broken, and recommend not to use it. Under 4965Unix, I recommend to use C-Kermit for general purpose use (and 4966especially for kermit binary protocol download ("loadb" command), and 4967use "cu" for S-Record download ("loads" command). See 4968http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4969for help with kermit. 4970 4971 4972Nevertheless, if you absolutely want to use it try adding this 4973configuration to your "File transfer protocols" section: 4974 4975 Name Program Name U/D FullScr IO-Red. Multi 4976 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4977 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4978 4979 4980NetBSD Notes: 4981============= 4982 4983Starting at version 0.9.2, U-Boot supports NetBSD both as host 4984(build U-Boot) and target system (boots NetBSD/mpc8xx). 4985 4986Building requires a cross environment; it is known to work on 4987NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4988need gmake since the Makefiles are not compatible with BSD make). 4989Note that the cross-powerpc package does not install include files; 4990attempting to build U-Boot will fail because <machine/ansi.h> is 4991missing. This file has to be installed and patched manually: 4992 4993 # cd /usr/pkg/cross/powerpc-netbsd/include 4994 # mkdir powerpc 4995 # ln -s powerpc machine 4996 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4997 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4998 4999Native builds *don't* work due to incompatibilities between native 5000and U-Boot include files. 5001 5002Booting assumes that (the first part of) the image booted is a 5003stage-2 loader which in turn loads and then invokes the kernel 5004proper. Loader sources will eventually appear in the NetBSD source 5005tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5006meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5007 5008 5009Implementation Internals: 5010========================= 5011 5012The following is not intended to be a complete description of every 5013implementation detail. However, it should help to understand the 5014inner workings of U-Boot and make it easier to port it to custom 5015hardware. 5016 5017 5018Initial Stack, Global Data: 5019--------------------------- 5020 5021The implementation of U-Boot is complicated by the fact that U-Boot 5022starts running out of ROM (flash memory), usually without access to 5023system RAM (because the memory controller is not initialized yet). 5024This means that we don't have writable Data or BSS segments, and BSS 5025is not initialized as zero. To be able to get a C environment working 5026at all, we have to allocate at least a minimal stack. Implementation 5027options for this are defined and restricted by the CPU used: Some CPU 5028models provide on-chip memory (like the IMMR area on MPC8xx and 5029MPC826x processors), on others (parts of) the data cache can be 5030locked as (mis-) used as memory, etc. 5031 5032 Chris Hallinan posted a good summary of these issues to the 5033 U-Boot mailing list: 5034 5035 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5036 From: "Chris Hallinan" <clh@net1plus.com> 5037 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5038 ... 5039 5040 Correct me if I'm wrong, folks, but the way I understand it 5041 is this: Using DCACHE as initial RAM for Stack, etc, does not 5042 require any physical RAM backing up the cache. The cleverness 5043 is that the cache is being used as a temporary supply of 5044 necessary storage before the SDRAM controller is setup. It's 5045 beyond the scope of this list to explain the details, but you 5046 can see how this works by studying the cache architecture and 5047 operation in the architecture and processor-specific manuals. 5048 5049 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5050 is another option for the system designer to use as an 5051 initial stack/RAM area prior to SDRAM being available. Either 5052 option should work for you. Using CS 4 should be fine if your 5053 board designers haven't used it for something that would 5054 cause you grief during the initial boot! It is frequently not 5055 used. 5056 5057 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5058 with your processor/board/system design. The default value 5059 you will find in any recent u-boot distribution in 5060 walnut.h should work for you. I'd set it to a value larger 5061 than your SDRAM module. If you have a 64MB SDRAM module, set 5062 it above 400_0000. Just make sure your board has no resources 5063 that are supposed to respond to that address! That code in 5064 start.S has been around a while and should work as is when 5065 you get the config right. 5066 5067 -Chris Hallinan 5068 DS4.COM, Inc. 5069 5070It is essential to remember this, since it has some impact on the C 5071code for the initialization procedures: 5072 5073* Initialized global data (data segment) is read-only. Do not attempt 5074 to write it. 5075 5076* Do not use any uninitialized global data (or implicitly initialized 5077 as zero data - BSS segment) at all - this is undefined, initiali- 5078 zation is performed later (when relocating to RAM). 5079 5080* Stack space is very limited. Avoid big data buffers or things like 5081 that. 5082 5083Having only the stack as writable memory limits means we cannot use 5084normal global data to share information between the code. But it 5085turned out that the implementation of U-Boot can be greatly 5086simplified by making a global data structure (gd_t) available to all 5087functions. We could pass a pointer to this data as argument to _all_ 5088functions, but this would bloat the code. Instead we use a feature of 5089the GCC compiler (Global Register Variables) to share the data: we 5090place a pointer (gd) to the global data into a register which we 5091reserve for this purpose. 5092 5093When choosing a register for such a purpose we are restricted by the 5094relevant (E)ABI specifications for the current architecture, and by 5095GCC's implementation. 5096 5097For PowerPC, the following registers have specific use: 5098 R1: stack pointer 5099 R2: reserved for system use 5100 R3-R4: parameter passing and return values 5101 R5-R10: parameter passing 5102 R13: small data area pointer 5103 R30: GOT pointer 5104 R31: frame pointer 5105 5106 (U-Boot also uses R12 as internal GOT pointer. r12 5107 is a volatile register so r12 needs to be reset when 5108 going back and forth between asm and C) 5109 5110 ==> U-Boot will use R2 to hold a pointer to the global data 5111 5112 Note: on PPC, we could use a static initializer (since the 5113 address of the global data structure is known at compile time), 5114 but it turned out that reserving a register results in somewhat 5115 smaller code - although the code savings are not that big (on 5116 average for all boards 752 bytes for the whole U-Boot image, 5117 624 text + 127 data). 5118 5119On ARM, the following registers are used: 5120 5121 R0: function argument word/integer result 5122 R1-R3: function argument word 5123 R9: platform specific 5124 R10: stack limit (used only if stack checking is enabled) 5125 R11: argument (frame) pointer 5126 R12: temporary workspace 5127 R13: stack pointer 5128 R14: link register 5129 R15: program counter 5130 5131 ==> U-Boot will use R9 to hold a pointer to the global data 5132 5133 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5134 5135On Nios II, the ABI is documented here: 5136 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5137 5138 ==> U-Boot will use gp to hold a pointer to the global data 5139 5140 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5141 to access small data sections, so gp is free. 5142 5143On NDS32, the following registers are used: 5144 5145 R0-R1: argument/return 5146 R2-R5: argument 5147 R15: temporary register for assembler 5148 R16: trampoline register 5149 R28: frame pointer (FP) 5150 R29: global pointer (GP) 5151 R30: link register (LP) 5152 R31: stack pointer (SP) 5153 PC: program counter (PC) 5154 5155 ==> U-Boot will use R10 to hold a pointer to the global data 5156 5157NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5158or current versions of GCC may "optimize" the code too much. 5159 5160Memory Management: 5161------------------ 5162 5163U-Boot runs in system state and uses physical addresses, i.e. the 5164MMU is not used either for address mapping nor for memory protection. 5165 5166The available memory is mapped to fixed addresses using the memory 5167controller. In this process, a contiguous block is formed for each 5168memory type (Flash, SDRAM, SRAM), even when it consists of several 5169physical memory banks. 5170 5171U-Boot is installed in the first 128 kB of the first Flash bank (on 5172TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5173booting and sizing and initializing DRAM, the code relocates itself 5174to the upper end of DRAM. Immediately below the U-Boot code some 5175memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5176configuration setting]. Below that, a structure with global Board 5177Info data is placed, followed by the stack (growing downward). 5178 5179Additionally, some exception handler code is copied to the low 8 kB 5180of DRAM (0x00000000 ... 0x00001FFF). 5181 5182So a typical memory configuration with 16 MB of DRAM could look like 5183this: 5184 5185 0x0000 0000 Exception Vector code 5186 : 5187 0x0000 1FFF 5188 0x0000 2000 Free for Application Use 5189 : 5190 : 5191 5192 : 5193 : 5194 0x00FB FF20 Monitor Stack (Growing downward) 5195 0x00FB FFAC Board Info Data and permanent copy of global data 5196 0x00FC 0000 Malloc Arena 5197 : 5198 0x00FD FFFF 5199 0x00FE 0000 RAM Copy of Monitor Code 5200 ... eventually: LCD or video framebuffer 5201 ... eventually: pRAM (Protected RAM - unchanged by reset) 5202 0x00FF FFFF [End of RAM] 5203 5204 5205System Initialization: 5206---------------------- 5207 5208In the reset configuration, U-Boot starts at the reset entry point 5209(on most PowerPC systems at address 0x00000100). Because of the reset 5210configuration for CS0# this is a mirror of the on board Flash memory. 5211To be able to re-map memory U-Boot then jumps to its link address. 5212To be able to implement the initialization code in C, a (small!) 5213initial stack is set up in the internal Dual Ported RAM (in case CPUs 5214which provide such a feature like), or in a locked part of the data 5215cache. After that, U-Boot initializes the CPU core, the caches and 5216the SIU. 5217 5218Next, all (potentially) available memory banks are mapped using a 5219preliminary mapping. For example, we put them on 512 MB boundaries 5220(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5221on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5222programmed for SDRAM access. Using the temporary configuration, a 5223simple memory test is run that determines the size of the SDRAM 5224banks. 5225 5226When there is more than one SDRAM bank, and the banks are of 5227different size, the largest is mapped first. For equal size, the first 5228bank (CS2#) is mapped first. The first mapping is always for address 52290x00000000, with any additional banks following immediately to create 5230contiguous memory starting from 0. 5231 5232Then, the monitor installs itself at the upper end of the SDRAM area 5233and allocates memory for use by malloc() and for the global Board 5234Info data; also, the exception vector code is copied to the low RAM 5235pages, and the final stack is set up. 5236 5237Only after this relocation will you have a "normal" C environment; 5238until that you are restricted in several ways, mostly because you are 5239running from ROM, and because the code will have to be relocated to a 5240new address in RAM. 5241 5242 5243U-Boot Porting Guide: 5244---------------------- 5245 5246[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5247list, October 2002] 5248 5249 5250int main(int argc, char *argv[]) 5251{ 5252 sighandler_t no_more_time; 5253 5254 signal(SIGALRM, no_more_time); 5255 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5256 5257 if (available_money > available_manpower) { 5258 Pay consultant to port U-Boot; 5259 return 0; 5260 } 5261 5262 Download latest U-Boot source; 5263 5264 Subscribe to u-boot mailing list; 5265 5266 if (clueless) 5267 email("Hi, I am new to U-Boot, how do I get started?"); 5268 5269 while (learning) { 5270 Read the README file in the top level directory; 5271 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5272 Read applicable doc/*.README; 5273 Read the source, Luke; 5274 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5275 } 5276 5277 if (available_money > toLocalCurrency ($2500)) 5278 Buy a BDI3000; 5279 else 5280 Add a lot of aggravation and time; 5281 5282 if (a similar board exists) { /* hopefully... */ 5283 cp -a board/<similar> board/<myboard> 5284 cp include/configs/<similar>.h include/configs/<myboard>.h 5285 } else { 5286 Create your own board support subdirectory; 5287 Create your own board include/configs/<myboard>.h file; 5288 } 5289 Edit new board/<myboard> files 5290 Edit new include/configs/<myboard>.h 5291 5292 while (!accepted) { 5293 while (!running) { 5294 do { 5295 Add / modify source code; 5296 } until (compiles); 5297 Debug; 5298 if (clueless) 5299 email("Hi, I am having problems..."); 5300 } 5301 Send patch file to the U-Boot email list; 5302 if (reasonable critiques) 5303 Incorporate improvements from email list code review; 5304 else 5305 Defend code as written; 5306 } 5307 5308 return 0; 5309} 5310 5311void no_more_time (int sig) 5312{ 5313 hire_a_guru(); 5314} 5315 5316 5317Coding Standards: 5318----------------- 5319 5320All contributions to U-Boot should conform to the Linux kernel 5321coding style; see the file "Documentation/CodingStyle" and the script 5322"scripts/Lindent" in your Linux kernel source directory. 5323 5324Source files originating from a different project (for example the 5325MTD subsystem) are generally exempt from these guidelines and are not 5326reformatted to ease subsequent migration to newer versions of those 5327sources. 5328 5329Please note that U-Boot is implemented in C (and to some small parts in 5330Assembler); no C++ is used, so please do not use C++ style comments (//) 5331in your code. 5332 5333Please also stick to the following formatting rules: 5334- remove any trailing white space 5335- use TAB characters for indentation and vertical alignment, not spaces 5336- make sure NOT to use DOS '\r\n' line feeds 5337- do not add more than 2 consecutive empty lines to source files 5338- do not add trailing empty lines to source files 5339 5340Submissions which do not conform to the standards may be returned 5341with a request to reformat the changes. 5342 5343 5344Submitting Patches: 5345------------------- 5346 5347Since the number of patches for U-Boot is growing, we need to 5348establish some rules. Submissions which do not conform to these rules 5349may be rejected, even when they contain important and valuable stuff. 5350 5351Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5352 5353Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5354see http://lists.denx.de/mailman/listinfo/u-boot 5355 5356When you send a patch, please include the following information with 5357it: 5358 5359* For bug fixes: a description of the bug and how your patch fixes 5360 this bug. Please try to include a way of demonstrating that the 5361 patch actually fixes something. 5362 5363* For new features: a description of the feature and your 5364 implementation. 5365 5366* A CHANGELOG entry as plaintext (separate from the patch) 5367 5368* For major contributions, add a MAINTAINERS file with your 5369 information and associated file and directory references. 5370 5371* When you add support for a new board, don't forget to add a 5372 maintainer e-mail address to the boards.cfg file, too. 5373 5374* If your patch adds new configuration options, don't forget to 5375 document these in the README file. 5376 5377* The patch itself. If you are using git (which is *strongly* 5378 recommended) you can easily generate the patch using the 5379 "git format-patch". If you then use "git send-email" to send it to 5380 the U-Boot mailing list, you will avoid most of the common problems 5381 with some other mail clients. 5382 5383 If you cannot use git, use "diff -purN OLD NEW". If your version of 5384 diff does not support these options, then get the latest version of 5385 GNU diff. 5386 5387 The current directory when running this command shall be the parent 5388 directory of the U-Boot source tree (i. e. please make sure that 5389 your patch includes sufficient directory information for the 5390 affected files). 5391 5392 We prefer patches as plain text. MIME attachments are discouraged, 5393 and compressed attachments must not be used. 5394 5395* If one logical set of modifications affects or creates several 5396 files, all these changes shall be submitted in a SINGLE patch file. 5397 5398* Changesets that contain different, unrelated modifications shall be 5399 submitted as SEPARATE patches, one patch per changeset. 5400 5401 5402Notes: 5403 5404* Before sending the patch, run the buildman script on your patched 5405 source tree and make sure that no errors or warnings are reported 5406 for any of the boards. 5407 5408* Keep your modifications to the necessary minimum: A patch 5409 containing several unrelated changes or arbitrary reformats will be 5410 returned with a request to re-formatting / split it. 5411 5412* If you modify existing code, make sure that your new code does not 5413 add to the memory footprint of the code ;-) Small is beautiful! 5414 When adding new features, these should compile conditionally only 5415 (using #ifdef), and the resulting code with the new feature 5416 disabled must not need more memory than the old code without your 5417 modification. 5418 5419* Remember that there is a size limit of 100 kB per message on the 5420 u-boot mailing list. Bigger patches will be moderated. If they are 5421 reasonable and not too big, they will be acknowledged. But patches 5422 bigger than the size limit should be avoided. 5423