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_PCMCIA * PCMCIA support 816 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 817 host 818 CONFIG_CMD_PORTIO * Port I/O 819 CONFIG_CMD_READ * Read raw data from partition 820 CONFIG_CMD_REGINFO * Register dump 821 CONFIG_CMD_RUN run command in env variable 822 CONFIG_CMD_SANDBOX * sb command to access sandbox features 823 CONFIG_CMD_SAVES * save S record dump 824 CONFIG_CMD_SDRAM * print SDRAM configuration information 825 (requires CONFIG_CMD_I2C) 826 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 827 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 828 CONFIG_CMD_SOURCE "source" command Support 829 CONFIG_CMD_SPI * SPI serial bus support 830 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 831 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 832 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 833 CONFIG_CMD_TIMER * access to the system tick timer 834 CONFIG_CMD_USB * USB support 835 CONFIG_CMD_CDP * Cisco Discover Protocol support 836 CONFIG_CMD_XIMG Load part of Multi Image 837 CONFIG_CMD_UUID * Generate random UUID or GUID string 838 839 EXAMPLE: If you want all functions except of network 840 support you can write: 841 842 #include "config_cmd_all.h" 843 #undef CONFIG_CMD_NET 844 845 Other Commands: 846 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 847 848 Note: Don't enable the "icache" and "dcache" commands 849 (configuration option CONFIG_CMD_CACHE) unless you know 850 what you (and your U-Boot users) are doing. Data 851 cache cannot be enabled on systems like the 852 8xx (where accesses to the IMMR region must be 853 uncached), and it cannot be disabled on all other 854 systems where we (mis-) use the data cache to hold an 855 initial stack and some data. 856 857 858 XXX - this list needs to get updated! 859 860- Removal of commands 861 If no commands are needed to boot, you can disable 862 CONFIG_CMDLINE to remove them. In this case, the command line 863 will not be available, and when U-Boot wants to execute the 864 boot command (on start-up) it will call board_run_command() 865 instead. This can reduce image size significantly for very 866 simple boot procedures. 867 868- Regular expression support: 869 CONFIG_REGEX 870 If this variable is defined, U-Boot is linked against 871 the SLRE (Super Light Regular Expression) library, 872 which adds regex support to some commands, as for 873 example "env grep" and "setexpr". 874 875- Device tree: 876 CONFIG_OF_CONTROL 877 If this variable is defined, U-Boot will use a device tree 878 to configure its devices, instead of relying on statically 879 compiled #defines in the board file. This option is 880 experimental and only available on a few boards. The device 881 tree is available in the global data as gd->fdt_blob. 882 883 U-Boot needs to get its device tree from somewhere. This can 884 be done using one of the three options below: 885 886 CONFIG_OF_EMBED 887 If this variable is defined, U-Boot will embed a device tree 888 binary in its image. This device tree file should be in the 889 board directory and called <soc>-<board>.dts. The binary file 890 is then picked up in board_init_f() and made available through 891 the global data structure as gd->blob. 892 893 CONFIG_OF_SEPARATE 894 If this variable is defined, U-Boot will build a device tree 895 binary. It will be called u-boot.dtb. Architecture-specific 896 code will locate it at run-time. Generally this works by: 897 898 cat u-boot.bin u-boot.dtb >image.bin 899 900 and in fact, U-Boot does this for you, creating a file called 901 u-boot-dtb.bin which is useful in the common case. You can 902 still use the individual files if you need something more 903 exotic. 904 905 CONFIG_OF_BOARD 906 If this variable is defined, U-Boot will use the device tree 907 provided by the board at runtime instead of embedding one with 908 the image. Only boards defining board_fdt_blob_setup() support 909 this option (see include/fdtdec.h file). 910 911- Watchdog: 912 CONFIG_WATCHDOG 913 If this variable is defined, it enables watchdog 914 support for the SoC. There must be support in the SoC 915 specific code for a watchdog. For the 8xx 916 CPUs, the SIU Watchdog feature is enabled in the SYPCR 917 register. When supported for a specific SoC is 918 available, then no further board specific code should 919 be needed to use it. 920 921 CONFIG_HW_WATCHDOG 922 When using a watchdog circuitry external to the used 923 SoC, then define this variable and provide board 924 specific code for the "hw_watchdog_reset" function. 925 926 CONFIG_AT91_HW_WDT_TIMEOUT 927 specify the timeout in seconds. default 2 seconds. 928 929- U-Boot Version: 930 CONFIG_VERSION_VARIABLE 931 If this variable is defined, an environment variable 932 named "ver" is created by U-Boot showing the U-Boot 933 version as printed by the "version" command. 934 Any change to this variable will be reverted at the 935 next reset. 936 937- Real-Time Clock: 938 939 When CONFIG_CMD_DATE is selected, the type of the RTC 940 has to be selected, too. Define exactly one of the 941 following options: 942 943 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 944 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 945 CONFIG_RTC_MC146818 - use MC146818 RTC 946 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 947 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 948 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 949 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 950 CONFIG_RTC_DS164x - use Dallas DS164x RTC 951 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 952 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 953 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 954 CONFIG_SYS_RV3029_TCR - enable trickle charger on 955 RV3029 RTC. 956 957 Note that if the RTC uses I2C, then the I2C interface 958 must also be configured. See I2C Support, below. 959 960- GPIO Support: 961 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 962 963 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 964 chip-ngpio pairs that tell the PCA953X driver the number of 965 pins supported by a particular chip. 966 967 Note that if the GPIO device uses I2C, then the I2C interface 968 must also be configured. See I2C Support, below. 969 970- I/O tracing: 971 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 972 accesses and can checksum them or write a list of them out 973 to memory. See the 'iotrace' command for details. This is 974 useful for testing device drivers since it can confirm that 975 the driver behaves the same way before and after a code 976 change. Currently this is supported on sandbox and arm. To 977 add support for your architecture, add '#include <iotrace.h>' 978 to the bottom of arch/<arch>/include/asm/io.h and test. 979 980 Example output from the 'iotrace stats' command is below. 981 Note that if the trace buffer is exhausted, the checksum will 982 still continue to operate. 983 984 iotrace is enabled 985 Start: 10000000 (buffer start address) 986 Size: 00010000 (buffer size) 987 Offset: 00000120 (current buffer offset) 988 Output: 10000120 (start + offset) 989 Count: 00000018 (number of trace records) 990 CRC32: 9526fb66 (CRC32 of all trace records) 991 992- Timestamp Support: 993 994 When CONFIG_TIMESTAMP is selected, the timestamp 995 (date and time) of an image is printed by image 996 commands like bootm or iminfo. This option is 997 automatically enabled when you select CONFIG_CMD_DATE . 998 999- Partition Labels (disklabels) Supported: 1000 Zero or more of the following: 1001 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1002 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1003 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1004 bootloader. Note 2TB partition limit; see 1005 disk/part_efi.c 1006 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1007 1008 If IDE or SCSI support is enabled (CONFIG_IDE or 1009 CONFIG_SCSI) you must configure support for at 1010 least one non-MTD partition type as well. 1011 1012- IDE Reset method: 1013 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1014 board configurations files but used nowhere! 1015 1016 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1017 be performed by calling the function 1018 ide_set_reset(int reset) 1019 which has to be defined in a board specific file 1020 1021- ATAPI Support: 1022 CONFIG_ATAPI 1023 1024 Set this to enable ATAPI support. 1025 1026- LBA48 Support 1027 CONFIG_LBA48 1028 1029 Set this to enable support for disks larger than 137GB 1030 Also look at CONFIG_SYS_64BIT_LBA. 1031 Whithout these , LBA48 support uses 32bit variables and will 'only' 1032 support disks up to 2.1TB. 1033 1034 CONFIG_SYS_64BIT_LBA: 1035 When enabled, makes the IDE subsystem use 64bit sector addresses. 1036 Default is 32bit. 1037 1038- SCSI Support: 1039 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1040 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1041 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1042 maximum numbers of LUNs, SCSI ID's and target 1043 devices. 1044 1045 The environment variable 'scsidevs' is set to the number of 1046 SCSI devices found during the last scan. 1047 1048- NETWORK Support (PCI): 1049 CONFIG_E1000 1050 Support for Intel 8254x/8257x gigabit chips. 1051 1052 CONFIG_E1000_SPI 1053 Utility code for direct access to the SPI bus on Intel 8257x. 1054 This does not do anything useful unless you set at least one 1055 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1056 1057 CONFIG_E1000_SPI_GENERIC 1058 Allow generic access to the SPI bus on the Intel 8257x, for 1059 example with the "sspi" command. 1060 1061 CONFIG_CMD_E1000 1062 Management command for E1000 devices. When used on devices 1063 with SPI support you can reprogram the EEPROM from U-Boot. 1064 1065 CONFIG_EEPRO100 1066 Support for Intel 82557/82559/82559ER chips. 1067 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1068 write routine for first time initialisation. 1069 1070 CONFIG_TULIP 1071 Support for Digital 2114x chips. 1072 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1073 modem chip initialisation (KS8761/QS6611). 1074 1075 CONFIG_NATSEMI 1076 Support for National dp83815 chips. 1077 1078 CONFIG_NS8382X 1079 Support for National dp8382[01] gigabit chips. 1080 1081- NETWORK Support (other): 1082 1083 CONFIG_DRIVER_AT91EMAC 1084 Support for AT91RM9200 EMAC. 1085 1086 CONFIG_RMII 1087 Define this to use reduced MII inteface 1088 1089 CONFIG_DRIVER_AT91EMAC_QUIET 1090 If this defined, the driver is quiet. 1091 The driver doen't show link status messages. 1092 1093 CONFIG_CALXEDA_XGMAC 1094 Support for the Calxeda XGMAC device 1095 1096 CONFIG_LAN91C96 1097 Support for SMSC's LAN91C96 chips. 1098 1099 CONFIG_LAN91C96_USE_32_BIT 1100 Define this to enable 32 bit addressing 1101 1102 CONFIG_SMC91111 1103 Support for SMSC's LAN91C111 chip 1104 1105 CONFIG_SMC91111_BASE 1106 Define this to hold the physical address 1107 of the device (I/O space) 1108 1109 CONFIG_SMC_USE_32_BIT 1110 Define this if data bus is 32 bits 1111 1112 CONFIG_SMC_USE_IOFUNCS 1113 Define this to use i/o functions instead of macros 1114 (some hardware wont work with macros) 1115 1116 CONFIG_DRIVER_TI_EMAC 1117 Support for davinci emac 1118 1119 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1120 Define this if you have more then 3 PHYs. 1121 1122 CONFIG_FTGMAC100 1123 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1124 1125 CONFIG_FTGMAC100_EGIGA 1126 Define this to use GE link update with gigabit PHY. 1127 Define this if FTGMAC100 is connected to gigabit PHY. 1128 If your system has 10/100 PHY only, it might not occur 1129 wrong behavior. Because PHY usually return timeout or 1130 useless data when polling gigabit status and gigabit 1131 control registers. This behavior won't affect the 1132 correctnessof 10/100 link speed update. 1133 1134 CONFIG_SMC911X 1135 Support for SMSC's LAN911x and LAN921x chips 1136 1137 CONFIG_SMC911X_BASE 1138 Define this to hold the physical address 1139 of the device (I/O space) 1140 1141 CONFIG_SMC911X_32_BIT 1142 Define this if data bus is 32 bits 1143 1144 CONFIG_SMC911X_16_BIT 1145 Define this if data bus is 16 bits. If your processor 1146 automatically converts one 32 bit word to two 16 bit 1147 words you may also try CONFIG_SMC911X_32_BIT. 1148 1149 CONFIG_SH_ETHER 1150 Support for Renesas on-chip Ethernet controller 1151 1152 CONFIG_SH_ETHER_USE_PORT 1153 Define the number of ports to be used 1154 1155 CONFIG_SH_ETHER_PHY_ADDR 1156 Define the ETH PHY's address 1157 1158 CONFIG_SH_ETHER_CACHE_WRITEBACK 1159 If this option is set, the driver enables cache flush. 1160 1161- PWM Support: 1162 CONFIG_PWM_IMX 1163 Support for PWM module on the imx6. 1164 1165- TPM Support: 1166 CONFIG_TPM 1167 Support TPM devices. 1168 1169 CONFIG_TPM_TIS_INFINEON 1170 Support for Infineon i2c bus TPM devices. Only one device 1171 per system is supported at this time. 1172 1173 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1174 Define the burst count bytes upper limit 1175 1176 CONFIG_TPM_ST33ZP24 1177 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1178 1179 CONFIG_TPM_ST33ZP24_I2C 1180 Support for STMicroelectronics ST33ZP24 I2C devices. 1181 Requires TPM_ST33ZP24 and I2C. 1182 1183 CONFIG_TPM_ST33ZP24_SPI 1184 Support for STMicroelectronics ST33ZP24 SPI devices. 1185 Requires TPM_ST33ZP24 and SPI. 1186 1187 CONFIG_TPM_ATMEL_TWI 1188 Support for Atmel TWI TPM device. Requires I2C support. 1189 1190 CONFIG_TPM_TIS_LPC 1191 Support for generic parallel port TPM devices. Only one device 1192 per system is supported at this time. 1193 1194 CONFIG_TPM_TIS_BASE_ADDRESS 1195 Base address where the generic TPM device is mapped 1196 to. Contemporary x86 systems usually map it at 1197 0xfed40000. 1198 1199 CONFIG_CMD_TPM 1200 Add tpm monitor functions. 1201 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1202 provides monitor access to authorized functions. 1203 1204 CONFIG_TPM 1205 Define this to enable the TPM support library which provides 1206 functional interfaces to some TPM commands. 1207 Requires support for a TPM device. 1208 1209 CONFIG_TPM_AUTH_SESSIONS 1210 Define this to enable authorized functions in the TPM library. 1211 Requires CONFIG_TPM and CONFIG_SHA1. 1212 1213- USB Support: 1214 At the moment only the UHCI host controller is 1215 supported (PIP405, MIP405); define 1216 CONFIG_USB_UHCI to enable it. 1217 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1218 and define CONFIG_USB_STORAGE to enable the USB 1219 storage devices. 1220 Note: 1221 Supported are USB Keyboards and USB Floppy drives 1222 (TEAC FD-05PUB). 1223 1224 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1225 txfilltuning field in the EHCI controller on reset. 1226 1227 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1228 HW module registers. 1229 1230- USB Device: 1231 Define the below if you wish to use the USB console. 1232 Once firmware is rebuilt from a serial console issue the 1233 command "setenv stdin usbtty; setenv stdout usbtty" and 1234 attach your USB cable. The Unix command "dmesg" should print 1235 it has found a new device. The environment variable usbtty 1236 can be set to gserial or cdc_acm to enable your device to 1237 appear to a USB host as a Linux gserial device or a 1238 Common Device Class Abstract Control Model serial device. 1239 If you select usbtty = gserial you should be able to enumerate 1240 a Linux host by 1241 # modprobe usbserial vendor=0xVendorID product=0xProductID 1242 else if using cdc_acm, simply setting the environment 1243 variable usbtty to be cdc_acm should suffice. The following 1244 might be defined in YourBoardName.h 1245 1246 CONFIG_USB_DEVICE 1247 Define this to build a UDC device 1248 1249 CONFIG_USB_TTY 1250 Define this to have a tty type of device available to 1251 talk to the UDC device 1252 1253 CONFIG_USBD_HS 1254 Define this to enable the high speed support for usb 1255 device and usbtty. If this feature is enabled, a routine 1256 int is_usbd_high_speed(void) 1257 also needs to be defined by the driver to dynamically poll 1258 whether the enumeration has succeded at high speed or full 1259 speed. 1260 1261 CONFIG_SYS_CONSOLE_IS_IN_ENV 1262 Define this if you want stdin, stdout &/or stderr to 1263 be set to usbtty. 1264 1265 If you have a USB-IF assigned VendorID then you may wish to 1266 define your own vendor specific values either in BoardName.h 1267 or directly in usbd_vendor_info.h. If you don't define 1268 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1269 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1270 should pretend to be a Linux device to it's target host. 1271 1272 CONFIG_USBD_MANUFACTURER 1273 Define this string as the name of your company for 1274 - CONFIG_USBD_MANUFACTURER "my company" 1275 1276 CONFIG_USBD_PRODUCT_NAME 1277 Define this string as the name of your product 1278 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1279 1280 CONFIG_USBD_VENDORID 1281 Define this as your assigned Vendor ID from the USB 1282 Implementors Forum. This *must* be a genuine Vendor ID 1283 to avoid polluting the USB namespace. 1284 - CONFIG_USBD_VENDORID 0xFFFF 1285 1286 CONFIG_USBD_PRODUCTID 1287 Define this as the unique Product ID 1288 for your device 1289 - CONFIG_USBD_PRODUCTID 0xFFFF 1290 1291- ULPI Layer Support: 1292 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1293 the generic ULPI layer. The generic layer accesses the ULPI PHY 1294 via the platform viewport, so you need both the genric layer and 1295 the viewport enabled. Currently only Chipidea/ARC based 1296 viewport is supported. 1297 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1298 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1299 If your ULPI phy needs a different reference clock than the 1300 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1301 the appropriate value in Hz. 1302 1303- MMC Support: 1304 The MMC controller on the Intel PXA is supported. To 1305 enable this define CONFIG_MMC. The MMC can be 1306 accessed from the boot prompt by mapping the device 1307 to physical memory similar to flash. Command line is 1308 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1309 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1310 1311 CONFIG_SH_MMCIF 1312 Support for Renesas on-chip MMCIF controller 1313 1314 CONFIG_SH_MMCIF_ADDR 1315 Define the base address of MMCIF registers 1316 1317 CONFIG_SH_MMCIF_CLK 1318 Define the clock frequency for MMCIF 1319 1320 CONFIG_SUPPORT_EMMC_BOOT 1321 Enable some additional features of the eMMC boot partitions. 1322 1323 CONFIG_SUPPORT_EMMC_RPMB 1324 Enable the commands for reading, writing and programming the 1325 key for the Replay Protection Memory Block partition in eMMC. 1326 1327- USB Device Firmware Update (DFU) class support: 1328 CONFIG_USB_FUNCTION_DFU 1329 This enables the USB portion of the DFU USB class 1330 1331 CONFIG_CMD_DFU 1332 This enables the command "dfu" which is used to have 1333 U-Boot create a DFU class device via USB. This command 1334 requires that the "dfu_alt_info" environment variable be 1335 set and define the alt settings to expose to the host. 1336 1337 CONFIG_DFU_MMC 1338 This enables support for exposing (e)MMC devices via DFU. 1339 1340 CONFIG_DFU_NAND 1341 This enables support for exposing NAND devices via DFU. 1342 1343 CONFIG_DFU_RAM 1344 This enables support for exposing RAM via DFU. 1345 Note: DFU spec refer to non-volatile memory usage, but 1346 allow usages beyond the scope of spec - here RAM usage, 1347 one that would help mostly the developer. 1348 1349 CONFIG_SYS_DFU_DATA_BUF_SIZE 1350 Dfu transfer uses a buffer before writing data to the 1351 raw storage device. Make the size (in bytes) of this buffer 1352 configurable. The size of this buffer is also configurable 1353 through the "dfu_bufsiz" environment variable. 1354 1355 CONFIG_SYS_DFU_MAX_FILE_SIZE 1356 When updating files rather than the raw storage device, 1357 we use a static buffer to copy the file into and then write 1358 the buffer once we've been given the whole file. Define 1359 this to the maximum filesize (in bytes) for the buffer. 1360 Default is 4 MiB if undefined. 1361 1362 DFU_DEFAULT_POLL_TIMEOUT 1363 Poll timeout [ms], is the timeout a device can send to the 1364 host. The host must wait for this timeout before sending 1365 a subsequent DFU_GET_STATUS request to the device. 1366 1367 DFU_MANIFEST_POLL_TIMEOUT 1368 Poll timeout [ms], which the device sends to the host when 1369 entering dfuMANIFEST state. Host waits this timeout, before 1370 sending again an USB request to the device. 1371 1372- USB Device Android Fastboot support: 1373 CONFIG_USB_FUNCTION_FASTBOOT 1374 This enables the USB part of the fastboot gadget 1375 1376 CONFIG_CMD_FASTBOOT 1377 This enables the command "fastboot" which enables the Android 1378 fastboot mode for the platform's USB device. Fastboot is a USB 1379 protocol for downloading images, flashing and device control 1380 used on Android devices. 1381 See doc/README.android-fastboot for more information. 1382 1383 CONFIG_ANDROID_BOOT_IMAGE 1384 This enables support for booting images which use the Android 1385 image format header. 1386 1387 CONFIG_FASTBOOT_BUF_ADDR 1388 The fastboot protocol requires a large memory buffer for 1389 downloads. Define this to the starting RAM address to use for 1390 downloaded images. 1391 1392 CONFIG_FASTBOOT_BUF_SIZE 1393 The fastboot protocol requires a large memory buffer for 1394 downloads. This buffer should be as large as possible for a 1395 platform. Define this to the size available RAM for fastboot. 1396 1397 CONFIG_FASTBOOT_FLASH 1398 The fastboot protocol includes a "flash" command for writing 1399 the downloaded image to a non-volatile storage device. Define 1400 this to enable the "fastboot flash" command. 1401 1402 CONFIG_FASTBOOT_FLASH_MMC_DEV 1403 The fastboot "flash" command requires additional information 1404 regarding the non-volatile storage device. Define this to 1405 the eMMC device that fastboot should use to store the image. 1406 1407 CONFIG_FASTBOOT_GPT_NAME 1408 The fastboot "flash" command supports writing the downloaded 1409 image to the Protective MBR and the Primary GUID Partition 1410 Table. (Additionally, this downloaded image is post-processed 1411 to generate and write the Backup GUID Partition Table.) 1412 This occurs when the specified "partition name" on the 1413 "fastboot flash" command line matches this value. 1414 The default is "gpt" if undefined. 1415 1416 CONFIG_FASTBOOT_MBR_NAME 1417 The fastboot "flash" command supports writing the downloaded 1418 image to DOS MBR. 1419 This occurs when the "partition name" specified on the 1420 "fastboot flash" command line matches this value. 1421 If not defined the default value "mbr" is used. 1422 1423- Journaling Flash filesystem support: 1424 CONFIG_JFFS2_NAND 1425 Define these for a default partition on a NAND device 1426 1427 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1428 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1429 Define these for a default partition on a NOR device 1430 1431- Keyboard Support: 1432 See Kconfig help for available keyboard drivers. 1433 1434 CONFIG_KEYBOARD 1435 1436 Define this to enable a custom keyboard support. 1437 This simply calls drv_keyboard_init() which must be 1438 defined in your board-specific files. This option is deprecated 1439 and is only used by novena. For new boards, use driver model 1440 instead. 1441 1442- Video support: 1443 CONFIG_FSL_DIU_FB 1444 Enable the Freescale DIU video driver. Reference boards for 1445 SOCs that have a DIU should define this macro to enable DIU 1446 support, and should also define these other macros: 1447 1448 CONFIG_SYS_DIU_ADDR 1449 CONFIG_VIDEO 1450 CONFIG_CFB_CONSOLE 1451 CONFIG_VIDEO_SW_CURSOR 1452 CONFIG_VGA_AS_SINGLE_DEVICE 1453 CONFIG_VIDEO_LOGO 1454 CONFIG_VIDEO_BMP_LOGO 1455 1456 The DIU driver will look for the 'video-mode' environment 1457 variable, and if defined, enable the DIU as a console during 1458 boot. See the documentation file doc/README.video for a 1459 description of this variable. 1460 1461- LCD Support: CONFIG_LCD 1462 1463 Define this to enable LCD support (for output to LCD 1464 display); also select one of the supported displays 1465 by defining one of these: 1466 1467 CONFIG_ATMEL_LCD: 1468 1469 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1470 1471 CONFIG_NEC_NL6448AC33: 1472 1473 NEC NL6448AC33-18. Active, color, single scan. 1474 1475 CONFIG_NEC_NL6448BC20 1476 1477 NEC NL6448BC20-08. 6.5", 640x480. 1478 Active, color, single scan. 1479 1480 CONFIG_NEC_NL6448BC33_54 1481 1482 NEC NL6448BC33-54. 10.4", 640x480. 1483 Active, color, single scan. 1484 1485 CONFIG_SHARP_16x9 1486 1487 Sharp 320x240. Active, color, single scan. 1488 It isn't 16x9, and I am not sure what it is. 1489 1490 CONFIG_SHARP_LQ64D341 1491 1492 Sharp LQ64D341 display, 640x480. 1493 Active, color, single scan. 1494 1495 CONFIG_HLD1045 1496 1497 HLD1045 display, 640x480. 1498 Active, color, single scan. 1499 1500 CONFIG_OPTREX_BW 1501 1502 Optrex CBL50840-2 NF-FW 99 22 M5 1503 or 1504 Hitachi LMG6912RPFC-00T 1505 or 1506 Hitachi SP14Q002 1507 1508 320x240. Black & white. 1509 1510 CONFIG_LCD_ALIGNMENT 1511 1512 Normally the LCD is page-aligned (typically 4KB). If this is 1513 defined then the LCD will be aligned to this value instead. 1514 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1515 here, since it is cheaper to change data cache settings on 1516 a per-section basis. 1517 1518 1519 CONFIG_LCD_ROTATION 1520 1521 Sometimes, for example if the display is mounted in portrait 1522 mode or even if it's mounted landscape but rotated by 180degree, 1523 we need to rotate our content of the display relative to the 1524 framebuffer, so that user can read the messages which are 1525 printed out. 1526 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1527 initialized with a given rotation from "vl_rot" out of 1528 "vidinfo_t" which is provided by the board specific code. 1529 The value for vl_rot is coded as following (matching to 1530 fbcon=rotate:<n> linux-kernel commandline): 1531 0 = no rotation respectively 0 degree 1532 1 = 90 degree rotation 1533 2 = 180 degree rotation 1534 3 = 270 degree rotation 1535 1536 If CONFIG_LCD_ROTATION is not defined, the console will be 1537 initialized with 0degree rotation. 1538 1539 CONFIG_LCD_BMP_RLE8 1540 1541 Support drawing of RLE8-compressed bitmaps on the LCD. 1542 1543 CONFIG_I2C_EDID 1544 1545 Enables an 'i2c edid' command which can read EDID 1546 information over I2C from an attached LCD display. 1547 1548- Splash Screen Support: CONFIG_SPLASH_SCREEN 1549 1550 If this option is set, the environment is checked for 1551 a variable "splashimage". If found, the usual display 1552 of logo, copyright and system information on the LCD 1553 is suppressed and the BMP image at the address 1554 specified in "splashimage" is loaded instead. The 1555 console is redirected to the "nulldev", too. This 1556 allows for a "silent" boot where a splash screen is 1557 loaded very quickly after power-on. 1558 1559 CONFIG_SPLASHIMAGE_GUARD 1560 1561 If this option is set, then U-Boot will prevent the environment 1562 variable "splashimage" from being set to a problematic address 1563 (see doc/README.displaying-bmps). 1564 This option is useful for targets where, due to alignment 1565 restrictions, an improperly aligned BMP image will cause a data 1566 abort. If you think you will not have problems with unaligned 1567 accesses (for example because your toolchain prevents them) 1568 there is no need to set this option. 1569 1570 CONFIG_SPLASH_SCREEN_ALIGN 1571 1572 If this option is set the splash image can be freely positioned 1573 on the screen. Environment variable "splashpos" specifies the 1574 position as "x,y". If a positive number is given it is used as 1575 number of pixel from left/top. If a negative number is given it 1576 is used as number of pixel from right/bottom. You can also 1577 specify 'm' for centering the image. 1578 1579 Example: 1580 setenv splashpos m,m 1581 => image at center of screen 1582 1583 setenv splashpos 30,20 1584 => image at x = 30 and y = 20 1585 1586 setenv splashpos -10,m 1587 => vertically centered image 1588 at x = dspWidth - bmpWidth - 9 1589 1590- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1591 1592 If this option is set, additionally to standard BMP 1593 images, gzipped BMP images can be displayed via the 1594 splashscreen support or the bmp command. 1595 1596- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1597 1598 If this option is set, 8-bit RLE compressed BMP images 1599 can be displayed via the splashscreen support or the 1600 bmp command. 1601 1602- Compression support: 1603 CONFIG_GZIP 1604 1605 Enabled by default to support gzip compressed images. 1606 1607 CONFIG_BZIP2 1608 1609 If this option is set, support for bzip2 compressed 1610 images is included. If not, only uncompressed and gzip 1611 compressed images are supported. 1612 1613 NOTE: the bzip2 algorithm requires a lot of RAM, so 1614 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1615 be at least 4MB. 1616 1617- MII/PHY support: 1618 CONFIG_PHY_ADDR 1619 1620 The address of PHY on MII bus. 1621 1622 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1623 1624 The clock frequency of the MII bus 1625 1626 CONFIG_PHY_RESET_DELAY 1627 1628 Some PHY like Intel LXT971A need extra delay after 1629 reset before any MII register access is possible. 1630 For such PHY, set this option to the usec delay 1631 required. (minimum 300usec for LXT971A) 1632 1633 CONFIG_PHY_CMD_DELAY (ppc4xx) 1634 1635 Some PHY like Intel LXT971A need extra delay after 1636 command issued before MII status register can be read 1637 1638- IP address: 1639 CONFIG_IPADDR 1640 1641 Define a default value for the IP address to use for 1642 the default Ethernet interface, in case this is not 1643 determined through e.g. bootp. 1644 (Environment variable "ipaddr") 1645 1646- Server IP address: 1647 CONFIG_SERVERIP 1648 1649 Defines a default value for the IP address of a TFTP 1650 server to contact when using the "tftboot" command. 1651 (Environment variable "serverip") 1652 1653 CONFIG_KEEP_SERVERADDR 1654 1655 Keeps the server's MAC address, in the env 'serveraddr' 1656 for passing to bootargs (like Linux's netconsole option) 1657 1658- Gateway IP address: 1659 CONFIG_GATEWAYIP 1660 1661 Defines a default value for the IP address of the 1662 default router where packets to other networks are 1663 sent to. 1664 (Environment variable "gatewayip") 1665 1666- Subnet mask: 1667 CONFIG_NETMASK 1668 1669 Defines a default value for the subnet mask (or 1670 routing prefix) which is used to determine if an IP 1671 address belongs to the local subnet or needs to be 1672 forwarded through a router. 1673 (Environment variable "netmask") 1674 1675- Multicast TFTP Mode: 1676 CONFIG_MCAST_TFTP 1677 1678 Defines whether you want to support multicast TFTP as per 1679 rfc-2090; for example to work with atftp. Lets lots of targets 1680 tftp down the same boot image concurrently. Note: the Ethernet 1681 driver in use must provide a function: mcast() to join/leave a 1682 multicast group. 1683 1684- BOOTP Recovery Mode: 1685 CONFIG_BOOTP_RANDOM_DELAY 1686 1687 If you have many targets in a network that try to 1688 boot using BOOTP, you may want to avoid that all 1689 systems send out BOOTP requests at precisely the same 1690 moment (which would happen for instance at recovery 1691 from a power failure, when all systems will try to 1692 boot, thus flooding the BOOTP server. Defining 1693 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1694 inserted before sending out BOOTP requests. The 1695 following delays are inserted then: 1696 1697 1st BOOTP request: delay 0 ... 1 sec 1698 2nd BOOTP request: delay 0 ... 2 sec 1699 3rd BOOTP request: delay 0 ... 4 sec 1700 4th and following 1701 BOOTP requests: delay 0 ... 8 sec 1702 1703 CONFIG_BOOTP_ID_CACHE_SIZE 1704 1705 BOOTP packets are uniquely identified using a 32-bit ID. The 1706 server will copy the ID from client requests to responses and 1707 U-Boot will use this to determine if it is the destination of 1708 an incoming response. Some servers will check that addresses 1709 aren't in use before handing them out (usually using an ARP 1710 ping) and therefore take up to a few hundred milliseconds to 1711 respond. Network congestion may also influence the time it 1712 takes for a response to make it back to the client. If that 1713 time is too long, U-Boot will retransmit requests. In order 1714 to allow earlier responses to still be accepted after these 1715 retransmissions, U-Boot's BOOTP client keeps a small cache of 1716 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1717 cache. The default is to keep IDs for up to four outstanding 1718 requests. Increasing this will allow U-Boot to accept offers 1719 from a BOOTP client in networks with unusually high latency. 1720 1721- DHCP Advanced Options: 1722 You can fine tune the DHCP functionality by defining 1723 CONFIG_BOOTP_* symbols: 1724 1725 CONFIG_BOOTP_SUBNETMASK 1726 CONFIG_BOOTP_GATEWAY 1727 CONFIG_BOOTP_HOSTNAME 1728 CONFIG_BOOTP_NISDOMAIN 1729 CONFIG_BOOTP_BOOTPATH 1730 CONFIG_BOOTP_BOOTFILESIZE 1731 CONFIG_BOOTP_DNS 1732 CONFIG_BOOTP_DNS2 1733 CONFIG_BOOTP_SEND_HOSTNAME 1734 CONFIG_BOOTP_NTPSERVER 1735 CONFIG_BOOTP_TIMEOFFSET 1736 CONFIG_BOOTP_VENDOREX 1737 CONFIG_BOOTP_MAY_FAIL 1738 1739 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1740 environment variable, not the BOOTP server. 1741 1742 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1743 after the configured retry count, the call will fail 1744 instead of starting over. This can be used to fail over 1745 to Link-local IP address configuration if the DHCP server 1746 is not available. 1747 1748 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1749 serverip from a DHCP server, it is possible that more 1750 than one DNS serverip is offered to the client. 1751 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1752 serverip will be stored in the additional environment 1753 variable "dnsip2". The first DNS serverip is always 1754 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1755 is defined. 1756 1757 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1758 to do a dynamic update of a DNS server. To do this, they 1759 need the hostname of the DHCP requester. 1760 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1761 of the "hostname" environment variable is passed as 1762 option 12 to the DHCP server. 1763 1764 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1765 1766 A 32bit value in microseconds for a delay between 1767 receiving a "DHCP Offer" and sending the "DHCP Request". 1768 This fixes a problem with certain DHCP servers that don't 1769 respond 100% of the time to a "DHCP request". E.g. On an 1770 AT91RM9200 processor running at 180MHz, this delay needed 1771 to be *at least* 15,000 usec before a Windows Server 2003 1772 DHCP server would reply 100% of the time. I recommend at 1773 least 50,000 usec to be safe. The alternative is to hope 1774 that one of the retries will be successful but note that 1775 the DHCP timeout and retry process takes a longer than 1776 this delay. 1777 1778 - Link-local IP address negotiation: 1779 Negotiate with other link-local clients on the local network 1780 for an address that doesn't require explicit configuration. 1781 This is especially useful if a DHCP server cannot be guaranteed 1782 to exist in all environments that the device must operate. 1783 1784 See doc/README.link-local for more information. 1785 1786 - CDP Options: 1787 CONFIG_CDP_DEVICE_ID 1788 1789 The device id used in CDP trigger frames. 1790 1791 CONFIG_CDP_DEVICE_ID_PREFIX 1792 1793 A two character string which is prefixed to the MAC address 1794 of the device. 1795 1796 CONFIG_CDP_PORT_ID 1797 1798 A printf format string which contains the ascii name of 1799 the port. Normally is set to "eth%d" which sets 1800 eth0 for the first Ethernet, eth1 for the second etc. 1801 1802 CONFIG_CDP_CAPABILITIES 1803 1804 A 32bit integer which indicates the device capabilities; 1805 0x00000010 for a normal host which does not forwards. 1806 1807 CONFIG_CDP_VERSION 1808 1809 An ascii string containing the version of the software. 1810 1811 CONFIG_CDP_PLATFORM 1812 1813 An ascii string containing the name of the platform. 1814 1815 CONFIG_CDP_TRIGGER 1816 1817 A 32bit integer sent on the trigger. 1818 1819 CONFIG_CDP_POWER_CONSUMPTION 1820 1821 A 16bit integer containing the power consumption of the 1822 device in .1 of milliwatts. 1823 1824 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1825 1826 A byte containing the id of the VLAN. 1827 1828- Status LED: CONFIG_LED_STATUS 1829 1830 Several configurations allow to display the current 1831 status using a LED. For instance, the LED will blink 1832 fast while running U-Boot code, stop blinking as 1833 soon as a reply to a BOOTP request was received, and 1834 start blinking slow once the Linux kernel is running 1835 (supported by a status LED driver in the Linux 1836 kernel). Defining CONFIG_LED_STATUS enables this 1837 feature in U-Boot. 1838 1839 Additional options: 1840 1841 CONFIG_LED_STATUS_GPIO 1842 The status LED can be connected to a GPIO pin. 1843 In such cases, the gpio_led driver can be used as a 1844 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1845 to include the gpio_led driver in the U-Boot binary. 1846 1847 CONFIG_GPIO_LED_INVERTED_TABLE 1848 Some GPIO connected LEDs may have inverted polarity in which 1849 case the GPIO high value corresponds to LED off state and 1850 GPIO low value corresponds to LED on state. 1851 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1852 with a list of GPIO LEDs that have inverted polarity. 1853 1854- I2C Support: CONFIG_SYS_I2C 1855 1856 This enable the NEW i2c subsystem, and will allow you to use 1857 i2c commands at the u-boot command line (as long as you set 1858 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1859 based realtime clock chips or other i2c devices. See 1860 common/cmd_i2c.c for a description of the command line 1861 interface. 1862 1863 ported i2c driver to the new framework: 1864 - drivers/i2c/soft_i2c.c: 1865 - activate first bus with CONFIG_SYS_I2C_SOFT define 1866 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1867 for defining speed and slave address 1868 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1869 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1870 for defining speed and slave address 1871 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1872 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1873 for defining speed and slave address 1874 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1875 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1876 for defining speed and slave address 1877 1878 - drivers/i2c/fsl_i2c.c: 1879 - activate i2c driver with CONFIG_SYS_I2C_FSL 1880 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1881 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1882 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1883 bus. 1884 - If your board supports a second fsl i2c bus, define 1885 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1886 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1887 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1888 second bus. 1889 1890 - drivers/i2c/tegra_i2c.c: 1891 - activate this driver with CONFIG_SYS_I2C_TEGRA 1892 - This driver adds 4 i2c buses with a fix speed from 1893 100000 and the slave addr 0! 1894 1895 - drivers/i2c/ppc4xx_i2c.c 1896 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1897 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1898 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1899 1900 - drivers/i2c/i2c_mxc.c 1901 - activate this driver with CONFIG_SYS_I2C_MXC 1902 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1903 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1904 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1905 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1906 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1907 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1908 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1909 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1910 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1911 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1912 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1913 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1914 If those defines are not set, default value is 100000 1915 for speed, and 0 for slave. 1916 1917 - drivers/i2c/rcar_i2c.c: 1918 - activate this driver with CONFIG_SYS_I2C_RCAR 1919 - This driver adds 4 i2c buses 1920 1921 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1922 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1923 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1924 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1925 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1926 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1927 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1928 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1929 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1930 1931 - drivers/i2c/sh_i2c.c: 1932 - activate this driver with CONFIG_SYS_I2C_SH 1933 - This driver adds from 2 to 5 i2c buses 1934 1935 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1936 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1937 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1938 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1939 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1940 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1941 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1942 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1943 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1944 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1945 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1946 1947 - drivers/i2c/omap24xx_i2c.c 1948 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1949 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1950 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1951 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1952 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1953 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1954 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1955 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1956 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1957 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1958 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1959 1960 - drivers/i2c/zynq_i2c.c 1961 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1962 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1963 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1964 1965 - drivers/i2c/s3c24x0_i2c.c: 1966 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1967 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1968 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1969 with a fix speed from 100000 and the slave addr 0! 1970 1971 - drivers/i2c/ihs_i2c.c 1972 - activate this driver with CONFIG_SYS_I2C_IHS 1973 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1974 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1975 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1976 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1977 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1978 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1979 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1980 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1981 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1982 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1983 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1984 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1985 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1986 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1987 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1988 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1989 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1990 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1991 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1992 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1993 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1994 1995 additional defines: 1996 1997 CONFIG_SYS_NUM_I2C_BUSES 1998 Hold the number of i2c buses you want to use. 1999 2000 CONFIG_SYS_I2C_DIRECT_BUS 2001 define this, if you don't use i2c muxes on your hardware. 2002 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2003 omit this define. 2004 2005 CONFIG_SYS_I2C_MAX_HOPS 2006 define how many muxes are maximal consecutively connected 2007 on one i2c bus. If you not use i2c muxes, omit this 2008 define. 2009 2010 CONFIG_SYS_I2C_BUSES 2011 hold a list of buses you want to use, only used if 2012 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2013 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2014 CONFIG_SYS_NUM_I2C_BUSES = 9: 2015 2016 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2017 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2018 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2019 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2020 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2021 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2022 {1, {I2C_NULL_HOP}}, \ 2023 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2024 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2025 } 2026 2027 which defines 2028 bus 0 on adapter 0 without a mux 2029 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2030 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2031 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2032 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2033 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2034 bus 6 on adapter 1 without a mux 2035 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2036 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2037 2038 If you do not have i2c muxes on your board, omit this define. 2039 2040- Legacy I2C Support: 2041 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2042 then the following macros need to be defined (examples are 2043 from include/configs/lwmon.h): 2044 2045 I2C_INIT 2046 2047 (Optional). Any commands necessary to enable the I2C 2048 controller or configure ports. 2049 2050 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2051 2052 I2C_ACTIVE 2053 2054 The code necessary to make the I2C data line active 2055 (driven). If the data line is open collector, this 2056 define can be null. 2057 2058 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2059 2060 I2C_TRISTATE 2061 2062 The code necessary to make the I2C data line tri-stated 2063 (inactive). If the data line is open collector, this 2064 define can be null. 2065 2066 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2067 2068 I2C_READ 2069 2070 Code that returns true if the I2C data line is high, 2071 false if it is low. 2072 2073 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2074 2075 I2C_SDA(bit) 2076 2077 If <bit> is true, sets the I2C data line high. If it 2078 is false, it clears it (low). 2079 2080 eg: #define I2C_SDA(bit) \ 2081 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2082 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2083 2084 I2C_SCL(bit) 2085 2086 If <bit> is true, sets the I2C clock line high. If it 2087 is false, it clears it (low). 2088 2089 eg: #define I2C_SCL(bit) \ 2090 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2091 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2092 2093 I2C_DELAY 2094 2095 This delay is invoked four times per clock cycle so this 2096 controls the rate of data transfer. The data rate thus 2097 is 1 / (I2C_DELAY * 4). Often defined to be something 2098 like: 2099 2100 #define I2C_DELAY udelay(2) 2101 2102 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2103 2104 If your arch supports the generic GPIO framework (asm/gpio.h), 2105 then you may alternatively define the two GPIOs that are to be 2106 used as SCL / SDA. Any of the previous I2C_xxx macros will 2107 have GPIO-based defaults assigned to them as appropriate. 2108 2109 You should define these to the GPIO value as given directly to 2110 the generic GPIO functions. 2111 2112 CONFIG_SYS_I2C_INIT_BOARD 2113 2114 When a board is reset during an i2c bus transfer 2115 chips might think that the current transfer is still 2116 in progress. On some boards it is possible to access 2117 the i2c SCLK line directly, either by using the 2118 processor pin as a GPIO or by having a second pin 2119 connected to the bus. If this option is defined a 2120 custom i2c_init_board() routine in boards/xxx/board.c 2121 is run early in the boot sequence. 2122 2123 CONFIG_I2C_MULTI_BUS 2124 2125 This option allows the use of multiple I2C buses, each of which 2126 must have a controller. At any point in time, only one bus is 2127 active. To switch to a different bus, use the 'i2c dev' command. 2128 Note that bus numbering is zero-based. 2129 2130 CONFIG_SYS_I2C_NOPROBES 2131 2132 This option specifies a list of I2C devices that will be skipped 2133 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2134 is set, specify a list of bus-device pairs. Otherwise, specify 2135 a 1D array of device addresses 2136 2137 e.g. 2138 #undef CONFIG_I2C_MULTI_BUS 2139 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2140 2141 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2142 2143 #define CONFIG_I2C_MULTI_BUS 2144 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2145 2146 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2147 2148 CONFIG_SYS_SPD_BUS_NUM 2149 2150 If defined, then this indicates the I2C bus number for DDR SPD. 2151 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2152 2153 CONFIG_SYS_RTC_BUS_NUM 2154 2155 If defined, then this indicates the I2C bus number for the RTC. 2156 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2157 2158 CONFIG_SOFT_I2C_READ_REPEATED_START 2159 2160 defining this will force the i2c_read() function in 2161 the soft_i2c driver to perform an I2C repeated start 2162 between writing the address pointer and reading the 2163 data. If this define is omitted the default behaviour 2164 of doing a stop-start sequence will be used. Most I2C 2165 devices can use either method, but some require one or 2166 the other. 2167 2168- SPI Support: CONFIG_SPI 2169 2170 Enables SPI driver (so far only tested with 2171 SPI EEPROM, also an instance works with Crystal A/D and 2172 D/As on the SACSng board) 2173 2174 CONFIG_SH_SPI 2175 2176 Enables the driver for SPI controller on SuperH. Currently 2177 only SH7757 is supported. 2178 2179 CONFIG_SOFT_SPI 2180 2181 Enables a software (bit-bang) SPI driver rather than 2182 using hardware support. This is a general purpose 2183 driver that only requires three general I/O port pins 2184 (two outputs, one input) to function. If this is 2185 defined, the board configuration must define several 2186 SPI configuration items (port pins to use, etc). For 2187 an example, see include/configs/sacsng.h. 2188 2189 CONFIG_HARD_SPI 2190 2191 Enables a hardware SPI driver for general-purpose reads 2192 and writes. As with CONFIG_SOFT_SPI, the board configuration 2193 must define a list of chip-select function pointers. 2194 Currently supported on some MPC8xxx processors. For an 2195 example, see include/configs/mpc8349emds.h. 2196 2197 CONFIG_MXC_SPI 2198 2199 Enables the driver for the SPI controllers on i.MX and MXC 2200 SoCs. Currently i.MX31/35/51 are supported. 2201 2202 CONFIG_SYS_SPI_MXC_WAIT 2203 Timeout for waiting until spi transfer completed. 2204 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2205 2206- FPGA Support: CONFIG_FPGA 2207 2208 Enables FPGA subsystem. 2209 2210 CONFIG_FPGA_<vendor> 2211 2212 Enables support for specific chip vendors. 2213 (ALTERA, XILINX) 2214 2215 CONFIG_FPGA_<family> 2216 2217 Enables support for FPGA family. 2218 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2219 2220 CONFIG_FPGA_COUNT 2221 2222 Specify the number of FPGA devices to support. 2223 2224 CONFIG_SYS_FPGA_PROG_FEEDBACK 2225 2226 Enable printing of hash marks during FPGA configuration. 2227 2228 CONFIG_SYS_FPGA_CHECK_BUSY 2229 2230 Enable checks on FPGA configuration interface busy 2231 status by the configuration function. This option 2232 will require a board or device specific function to 2233 be written. 2234 2235 CONFIG_FPGA_DELAY 2236 2237 If defined, a function that provides delays in the FPGA 2238 configuration driver. 2239 2240 CONFIG_SYS_FPGA_CHECK_CTRLC 2241 Allow Control-C to interrupt FPGA configuration 2242 2243 CONFIG_SYS_FPGA_CHECK_ERROR 2244 2245 Check for configuration errors during FPGA bitfile 2246 loading. For example, abort during Virtex II 2247 configuration if the INIT_B line goes low (which 2248 indicated a CRC error). 2249 2250 CONFIG_SYS_FPGA_WAIT_INIT 2251 2252 Maximum time to wait for the INIT_B line to de-assert 2253 after PROB_B has been de-asserted during a Virtex II 2254 FPGA configuration sequence. The default time is 500 2255 ms. 2256 2257 CONFIG_SYS_FPGA_WAIT_BUSY 2258 2259 Maximum time to wait for BUSY to de-assert during 2260 Virtex II FPGA configuration. The default is 5 ms. 2261 2262 CONFIG_SYS_FPGA_WAIT_CONFIG 2263 2264 Time to wait after FPGA configuration. The default is 2265 200 ms. 2266 2267- Configuration Management: 2268 CONFIG_BUILD_TARGET 2269 2270 Some SoCs need special image types (e.g. U-Boot binary 2271 with a special header) as build targets. By defining 2272 CONFIG_BUILD_TARGET in the SoC / board header, this 2273 special image will be automatically built upon calling 2274 make / buildman. 2275 2276 CONFIG_IDENT_STRING 2277 2278 If defined, this string will be added to the U-Boot 2279 version information (U_BOOT_VERSION) 2280 2281- Vendor Parameter Protection: 2282 2283 U-Boot considers the values of the environment 2284 variables "serial#" (Board Serial Number) and 2285 "ethaddr" (Ethernet Address) to be parameters that 2286 are set once by the board vendor / manufacturer, and 2287 protects these variables from casual modification by 2288 the user. Once set, these variables are read-only, 2289 and write or delete attempts are rejected. You can 2290 change this behaviour: 2291 2292 If CONFIG_ENV_OVERWRITE is #defined in your config 2293 file, the write protection for vendor parameters is 2294 completely disabled. Anybody can change or delete 2295 these parameters. 2296 2297 Alternatively, if you define _both_ an ethaddr in the 2298 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2299 Ethernet address is installed in the environment, 2300 which can be changed exactly ONCE by the user. [The 2301 serial# is unaffected by this, i. e. it remains 2302 read-only.] 2303 2304 The same can be accomplished in a more flexible way 2305 for any variable by configuring the type of access 2306 to allow for those variables in the ".flags" variable 2307 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2308 2309- Protected RAM: 2310 CONFIG_PRAM 2311 2312 Define this variable to enable the reservation of 2313 "protected RAM", i. e. RAM which is not overwritten 2314 by U-Boot. Define CONFIG_PRAM to hold the number of 2315 kB you want to reserve for pRAM. You can overwrite 2316 this default value by defining an environment 2317 variable "pram" to the number of kB you want to 2318 reserve. Note that the board info structure will 2319 still show the full amount of RAM. If pRAM is 2320 reserved, a new environment variable "mem" will 2321 automatically be defined to hold the amount of 2322 remaining RAM in a form that can be passed as boot 2323 argument to Linux, for instance like that: 2324 2325 setenv bootargs ... mem=\${mem} 2326 saveenv 2327 2328 This way you can tell Linux not to use this memory, 2329 either, which results in a memory region that will 2330 not be affected by reboots. 2331 2332 *WARNING* If your board configuration uses automatic 2333 detection of the RAM size, you must make sure that 2334 this memory test is non-destructive. So far, the 2335 following board configurations are known to be 2336 "pRAM-clean": 2337 2338 IVMS8, IVML24, SPD8xx, 2339 HERMES, IP860, RPXlite, LWMON, 2340 FLAGADM 2341 2342- Access to physical memory region (> 4GB) 2343 Some basic support is provided for operations on memory not 2344 normally accessible to U-Boot - e.g. some architectures 2345 support access to more than 4GB of memory on 32-bit 2346 machines using physical address extension or similar. 2347 Define CONFIG_PHYSMEM to access this basic support, which 2348 currently only supports clearing the memory. 2349 2350- Error Recovery: 2351 CONFIG_PANIC_HANG 2352 2353 Define this variable to stop the system in case of a 2354 fatal error, so that you have to reset it manually. 2355 This is probably NOT a good idea for an embedded 2356 system where you want the system to reboot 2357 automatically as fast as possible, but it may be 2358 useful during development since you can try to debug 2359 the conditions that lead to the situation. 2360 2361 CONFIG_NET_RETRY_COUNT 2362 2363 This variable defines the number of retries for 2364 network operations like ARP, RARP, TFTP, or BOOTP 2365 before giving up the operation. If not defined, a 2366 default value of 5 is used. 2367 2368 CONFIG_ARP_TIMEOUT 2369 2370 Timeout waiting for an ARP reply in milliseconds. 2371 2372 CONFIG_NFS_TIMEOUT 2373 2374 Timeout in milliseconds used in NFS protocol. 2375 If you encounter "ERROR: Cannot umount" in nfs command, 2376 try longer timeout such as 2377 #define CONFIG_NFS_TIMEOUT 10000UL 2378 2379- Command Interpreter: 2380 CONFIG_AUTO_COMPLETE 2381 2382 Enable auto completion of commands using TAB. 2383 2384 CONFIG_SYS_PROMPT_HUSH_PS2 2385 2386 This defines the secondary prompt string, which is 2387 printed when the command interpreter needs more input 2388 to complete a command. Usually "> ". 2389 2390 Note: 2391 2392 In the current implementation, the local variables 2393 space and global environment variables space are 2394 separated. Local variables are those you define by 2395 simply typing `name=value'. To access a local 2396 variable later on, you have write `$name' or 2397 `${name}'; to execute the contents of a variable 2398 directly type `$name' at the command prompt. 2399 2400 Global environment variables are those you use 2401 setenv/printenv to work with. To run a command stored 2402 in such a variable, you need to use the run command, 2403 and you must not use the '$' sign to access them. 2404 2405 To store commands and special characters in a 2406 variable, please use double quotation marks 2407 surrounding the whole text of the variable, instead 2408 of the backslashes before semicolons and special 2409 symbols. 2410 2411- Command Line Editing and History: 2412 CONFIG_CMDLINE_EDITING 2413 2414 Enable editing and History functions for interactive 2415 command line input operations 2416 2417- Command Line PS1/PS2 support: 2418 CONFIG_CMDLINE_PS_SUPPORT 2419 2420 Enable support for changing the command prompt string 2421 at run-time. Only static string is supported so far. 2422 The string is obtained from environment variables PS1 2423 and PS2. 2424 2425- Default Environment: 2426 CONFIG_EXTRA_ENV_SETTINGS 2427 2428 Define this to contain any number of null terminated 2429 strings (variable = value pairs) that will be part of 2430 the default environment compiled into the boot image. 2431 2432 For example, place something like this in your 2433 board's config file: 2434 2435 #define CONFIG_EXTRA_ENV_SETTINGS \ 2436 "myvar1=value1\0" \ 2437 "myvar2=value2\0" 2438 2439 Warning: This method is based on knowledge about the 2440 internal format how the environment is stored by the 2441 U-Boot code. This is NOT an official, exported 2442 interface! Although it is unlikely that this format 2443 will change soon, there is no guarantee either. 2444 You better know what you are doing here. 2445 2446 Note: overly (ab)use of the default environment is 2447 discouraged. Make sure to check other ways to preset 2448 the environment like the "source" command or the 2449 boot command first. 2450 2451 CONFIG_ENV_VARS_UBOOT_CONFIG 2452 2453 Define this in order to add variables describing the 2454 U-Boot build configuration to the default environment. 2455 These will be named arch, cpu, board, vendor, and soc. 2456 2457 Enabling this option will cause the following to be defined: 2458 2459 - CONFIG_SYS_ARCH 2460 - CONFIG_SYS_CPU 2461 - CONFIG_SYS_BOARD 2462 - CONFIG_SYS_VENDOR 2463 - CONFIG_SYS_SOC 2464 2465 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2466 2467 Define this in order to add variables describing certain 2468 run-time determined information about the hardware to the 2469 environment. These will be named board_name, board_rev. 2470 2471 CONFIG_DELAY_ENVIRONMENT 2472 2473 Normally the environment is loaded when the board is 2474 initialised so that it is available to U-Boot. This inhibits 2475 that so that the environment is not available until 2476 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2477 this is instead controlled by the value of 2478 /config/load-environment. 2479 2480- DataFlash Support: 2481 CONFIG_HAS_DATAFLASH 2482 2483 Defining this option enables DataFlash features and 2484 allows to read/write in Dataflash via the standard 2485 commands cp, md... 2486 2487- Serial Flash support 2488 CONFIG_CMD_SF 2489 2490 Defining this option enables SPI flash commands 2491 'sf probe/read/write/erase/update'. 2492 2493 Usage requires an initial 'probe' to define the serial 2494 flash parameters, followed by read/write/erase/update 2495 commands. 2496 2497 The following defaults may be provided by the platform 2498 to handle the common case when only a single serial 2499 flash is present on the system. 2500 2501 CONFIG_SF_DEFAULT_BUS Bus identifier 2502 CONFIG_SF_DEFAULT_CS Chip-select 2503 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2504 CONFIG_SF_DEFAULT_SPEED in Hz 2505 2506 CONFIG_CMD_SF_TEST 2507 2508 Define this option to include a destructive SPI flash 2509 test ('sf test'). 2510 2511- SystemACE Support: 2512 CONFIG_SYSTEMACE 2513 2514 Adding this option adds support for Xilinx SystemACE 2515 chips attached via some sort of local bus. The address 2516 of the chip must also be defined in the 2517 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2518 2519 #define CONFIG_SYSTEMACE 2520 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2521 2522 When SystemACE support is added, the "ace" device type 2523 becomes available to the fat commands, i.e. fatls. 2524 2525- TFTP Fixed UDP Port: 2526 CONFIG_TFTP_PORT 2527 2528 If this is defined, the environment variable tftpsrcp 2529 is used to supply the TFTP UDP source port value. 2530 If tftpsrcp isn't defined, the normal pseudo-random port 2531 number generator is used. 2532 2533 Also, the environment variable tftpdstp is used to supply 2534 the TFTP UDP destination port value. If tftpdstp isn't 2535 defined, the normal port 69 is used. 2536 2537 The purpose for tftpsrcp is to allow a TFTP server to 2538 blindly start the TFTP transfer using the pre-configured 2539 target IP address and UDP port. This has the effect of 2540 "punching through" the (Windows XP) firewall, allowing 2541 the remainder of the TFTP transfer to proceed normally. 2542 A better solution is to properly configure the firewall, 2543 but sometimes that is not allowed. 2544 2545- bootcount support: 2546 CONFIG_BOOTCOUNT_LIMIT 2547 2548 This enables the bootcounter support, see: 2549 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2550 2551 CONFIG_AT91SAM9XE 2552 enable special bootcounter support on at91sam9xe based boards. 2553 CONFIG_SOC_DA8XX 2554 enable special bootcounter support on da850 based boards. 2555 CONFIG_BOOTCOUNT_RAM 2556 enable support for the bootcounter in RAM 2557 CONFIG_BOOTCOUNT_I2C 2558 enable support for the bootcounter on an i2c (like RTC) device. 2559 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2560 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2561 the bootcounter. 2562 CONFIG_BOOTCOUNT_ALEN = address len 2563 2564- Show boot progress: 2565 CONFIG_SHOW_BOOT_PROGRESS 2566 2567 Defining this option allows to add some board- 2568 specific code (calling a user-provided function 2569 "show_boot_progress(int)") that enables you to show 2570 the system's boot progress on some display (for 2571 example, some LED's) on your board. At the moment, 2572 the following checkpoints are implemented: 2573 2574 2575Legacy uImage format: 2576 2577 Arg Where When 2578 1 common/cmd_bootm.c before attempting to boot an image 2579 -1 common/cmd_bootm.c Image header has bad magic number 2580 2 common/cmd_bootm.c Image header has correct magic number 2581 -2 common/cmd_bootm.c Image header has bad checksum 2582 3 common/cmd_bootm.c Image header has correct checksum 2583 -3 common/cmd_bootm.c Image data has bad checksum 2584 4 common/cmd_bootm.c Image data has correct checksum 2585 -4 common/cmd_bootm.c Image is for unsupported architecture 2586 5 common/cmd_bootm.c Architecture check OK 2587 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2588 6 common/cmd_bootm.c Image Type check OK 2589 -6 common/cmd_bootm.c gunzip uncompression error 2590 -7 common/cmd_bootm.c Unimplemented compression type 2591 7 common/cmd_bootm.c Uncompression OK 2592 8 common/cmd_bootm.c No uncompress/copy overwrite error 2593 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2594 2595 9 common/image.c Start initial ramdisk verification 2596 -10 common/image.c Ramdisk header has bad magic number 2597 -11 common/image.c Ramdisk header has bad checksum 2598 10 common/image.c Ramdisk header is OK 2599 -12 common/image.c Ramdisk data has bad checksum 2600 11 common/image.c Ramdisk data has correct checksum 2601 12 common/image.c Ramdisk verification complete, start loading 2602 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2603 13 common/image.c Start multifile image verification 2604 14 common/image.c No initial ramdisk, no multifile, continue. 2605 2606 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2607 2608 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2609 -31 post/post.c POST test failed, detected by post_output_backlog() 2610 -32 post/post.c POST test failed, detected by post_run_single() 2611 2612 34 common/cmd_doc.c before loading a Image from a DOC device 2613 -35 common/cmd_doc.c Bad usage of "doc" command 2614 35 common/cmd_doc.c correct usage of "doc" command 2615 -36 common/cmd_doc.c No boot device 2616 36 common/cmd_doc.c correct boot device 2617 -37 common/cmd_doc.c Unknown Chip ID on boot device 2618 37 common/cmd_doc.c correct chip ID found, device available 2619 -38 common/cmd_doc.c Read Error on boot device 2620 38 common/cmd_doc.c reading Image header from DOC device OK 2621 -39 common/cmd_doc.c Image header has bad magic number 2622 39 common/cmd_doc.c Image header has correct magic number 2623 -40 common/cmd_doc.c Error reading Image from DOC device 2624 40 common/cmd_doc.c Image header has correct magic number 2625 41 common/cmd_ide.c before loading a Image from a IDE device 2626 -42 common/cmd_ide.c Bad usage of "ide" command 2627 42 common/cmd_ide.c correct usage of "ide" command 2628 -43 common/cmd_ide.c No boot device 2629 43 common/cmd_ide.c boot device found 2630 -44 common/cmd_ide.c Device not available 2631 44 common/cmd_ide.c Device available 2632 -45 common/cmd_ide.c wrong partition selected 2633 45 common/cmd_ide.c partition selected 2634 -46 common/cmd_ide.c Unknown partition table 2635 46 common/cmd_ide.c valid partition table found 2636 -47 common/cmd_ide.c Invalid partition type 2637 47 common/cmd_ide.c correct partition type 2638 -48 common/cmd_ide.c Error reading Image Header on boot device 2639 48 common/cmd_ide.c reading Image Header from IDE device OK 2640 -49 common/cmd_ide.c Image header has bad magic number 2641 49 common/cmd_ide.c Image header has correct magic number 2642 -50 common/cmd_ide.c Image header has bad checksum 2643 50 common/cmd_ide.c Image header has correct checksum 2644 -51 common/cmd_ide.c Error reading Image from IDE device 2645 51 common/cmd_ide.c reading Image from IDE device OK 2646 52 common/cmd_nand.c before loading a Image from a NAND device 2647 -53 common/cmd_nand.c Bad usage of "nand" command 2648 53 common/cmd_nand.c correct usage of "nand" command 2649 -54 common/cmd_nand.c No boot device 2650 54 common/cmd_nand.c boot device found 2651 -55 common/cmd_nand.c Unknown Chip ID on boot device 2652 55 common/cmd_nand.c correct chip ID found, device available 2653 -56 common/cmd_nand.c Error reading Image Header on boot device 2654 56 common/cmd_nand.c reading Image Header from NAND device OK 2655 -57 common/cmd_nand.c Image header has bad magic number 2656 57 common/cmd_nand.c Image header has correct magic number 2657 -58 common/cmd_nand.c Error reading Image from NAND device 2658 58 common/cmd_nand.c reading Image from NAND device OK 2659 2660 -60 common/env_common.c Environment has a bad CRC, using default 2661 2662 64 net/eth.c starting with Ethernet configuration. 2663 -64 net/eth.c no Ethernet found. 2664 65 net/eth.c Ethernet found. 2665 2666 -80 common/cmd_net.c usage wrong 2667 80 common/cmd_net.c before calling net_loop() 2668 -81 common/cmd_net.c some error in net_loop() occurred 2669 81 common/cmd_net.c net_loop() back without error 2670 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2671 82 common/cmd_net.c trying automatic boot 2672 83 common/cmd_net.c running "source" command 2673 -83 common/cmd_net.c some error in automatic boot or "source" command 2674 84 common/cmd_net.c end without errors 2675 2676FIT uImage format: 2677 2678 Arg Where When 2679 100 common/cmd_bootm.c Kernel FIT Image has correct format 2680 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2681 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2682 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2683 102 common/cmd_bootm.c Kernel unit name specified 2684 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2685 103 common/cmd_bootm.c Found configuration node 2686 104 common/cmd_bootm.c Got kernel subimage node offset 2687 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2688 105 common/cmd_bootm.c Kernel subimage hash verification OK 2689 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2690 106 common/cmd_bootm.c Architecture check OK 2691 -106 common/cmd_bootm.c Kernel subimage has wrong type 2692 107 common/cmd_bootm.c Kernel subimage type OK 2693 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2694 108 common/cmd_bootm.c Got kernel subimage data/size 2695 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2696 -109 common/cmd_bootm.c Can't get kernel subimage type 2697 -110 common/cmd_bootm.c Can't get kernel subimage comp 2698 -111 common/cmd_bootm.c Can't get kernel subimage os 2699 -112 common/cmd_bootm.c Can't get kernel subimage load address 2700 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2701 2702 120 common/image.c Start initial ramdisk verification 2703 -120 common/image.c Ramdisk FIT image has incorrect format 2704 121 common/image.c Ramdisk FIT image has correct format 2705 122 common/image.c No ramdisk subimage unit name, using configuration 2706 -122 common/image.c Can't get configuration for ramdisk subimage 2707 123 common/image.c Ramdisk unit name specified 2708 -124 common/image.c Can't get ramdisk subimage node offset 2709 125 common/image.c Got ramdisk subimage node offset 2710 -125 common/image.c Ramdisk subimage hash verification failed 2711 126 common/image.c Ramdisk subimage hash verification OK 2712 -126 common/image.c Ramdisk subimage for unsupported architecture 2713 127 common/image.c Architecture check OK 2714 -127 common/image.c Can't get ramdisk subimage data/size 2715 128 common/image.c Got ramdisk subimage data/size 2716 129 common/image.c Can't get ramdisk load address 2717 -129 common/image.c Got ramdisk load address 2718 2719 -130 common/cmd_doc.c Incorrect FIT image format 2720 131 common/cmd_doc.c FIT image format OK 2721 2722 -140 common/cmd_ide.c Incorrect FIT image format 2723 141 common/cmd_ide.c FIT image format OK 2724 2725 -150 common/cmd_nand.c Incorrect FIT image format 2726 151 common/cmd_nand.c FIT image format OK 2727 2728- legacy image format: 2729 CONFIG_IMAGE_FORMAT_LEGACY 2730 enables the legacy image format support in U-Boot. 2731 2732 Default: 2733 enabled if CONFIG_FIT_SIGNATURE is not defined. 2734 2735 CONFIG_DISABLE_IMAGE_LEGACY 2736 disable the legacy image format 2737 2738 This define is introduced, as the legacy image format is 2739 enabled per default for backward compatibility. 2740 2741- Standalone program support: 2742 CONFIG_STANDALONE_LOAD_ADDR 2743 2744 This option defines a board specific value for the 2745 address where standalone program gets loaded, thus 2746 overwriting the architecture dependent default 2747 settings. 2748 2749- Frame Buffer Address: 2750 CONFIG_FB_ADDR 2751 2752 Define CONFIG_FB_ADDR if you want to use specific 2753 address for frame buffer. This is typically the case 2754 when using a graphics controller has separate video 2755 memory. U-Boot will then place the frame buffer at 2756 the given address instead of dynamically reserving it 2757 in system RAM by calling lcd_setmem(), which grabs 2758 the memory for the frame buffer depending on the 2759 configured panel size. 2760 2761 Please see board_init_f function. 2762 2763- Automatic software updates via TFTP server 2764 CONFIG_UPDATE_TFTP 2765 CONFIG_UPDATE_TFTP_CNT_MAX 2766 CONFIG_UPDATE_TFTP_MSEC_MAX 2767 2768 These options enable and control the auto-update feature; 2769 for a more detailed description refer to doc/README.update. 2770 2771- MTD Support (mtdparts command, UBI support) 2772 CONFIG_MTD_DEVICE 2773 2774 Adds the MTD device infrastructure from the Linux kernel. 2775 Needed for mtdparts command support. 2776 2777 CONFIG_MTD_PARTITIONS 2778 2779 Adds the MTD partitioning infrastructure from the Linux 2780 kernel. Needed for UBI support. 2781 2782- UBI support 2783 CONFIG_UBI_SILENCE_MSG 2784 2785 Make the verbose messages from UBI stop printing. This leaves 2786 warnings and errors enabled. 2787 2788 2789 CONFIG_MTD_UBI_WL_THRESHOLD 2790 This parameter defines the maximum difference between the highest 2791 erase counter value and the lowest erase counter value of eraseblocks 2792 of UBI devices. When this threshold is exceeded, UBI starts performing 2793 wear leveling by means of moving data from eraseblock with low erase 2794 counter to eraseblocks with high erase counter. 2795 2796 The default value should be OK for SLC NAND flashes, NOR flashes and 2797 other flashes which have eraseblock life-cycle 100000 or more. 2798 However, in case of MLC NAND flashes which typically have eraseblock 2799 life-cycle less than 10000, the threshold should be lessened (e.g., 2800 to 128 or 256, although it does not have to be power of 2). 2801 2802 default: 4096 2803 2804 CONFIG_MTD_UBI_BEB_LIMIT 2805 This option specifies the maximum bad physical eraseblocks UBI 2806 expects on the MTD device (per 1024 eraseblocks). If the 2807 underlying flash does not admit of bad eraseblocks (e.g. NOR 2808 flash), this value is ignored. 2809 2810 NAND datasheets often specify the minimum and maximum NVM 2811 (Number of Valid Blocks) for the flashes' endurance lifetime. 2812 The maximum expected bad eraseblocks per 1024 eraseblocks 2813 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2814 which gives 20 for most NANDs (MaxNVB is basically the total 2815 count of eraseblocks on the chip). 2816 2817 To put it differently, if this value is 20, UBI will try to 2818 reserve about 1.9% of physical eraseblocks for bad blocks 2819 handling. And that will be 1.9% of eraseblocks on the entire 2820 NAND chip, not just the MTD partition UBI attaches. This means 2821 that if you have, say, a NAND flash chip admits maximum 40 bad 2822 eraseblocks, and it is split on two MTD partitions of the same 2823 size, UBI will reserve 40 eraseblocks when attaching a 2824 partition. 2825 2826 default: 20 2827 2828 CONFIG_MTD_UBI_FASTMAP 2829 Fastmap is a mechanism which allows attaching an UBI device 2830 in nearly constant time. Instead of scanning the whole MTD device it 2831 only has to locate a checkpoint (called fastmap) on the device. 2832 The on-flash fastmap contains all information needed to attach 2833 the device. Using fastmap makes only sense on large devices where 2834 attaching by scanning takes long. UBI will not automatically install 2835 a fastmap on old images, but you can set the UBI parameter 2836 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2837 that fastmap-enabled images are still usable with UBI implementations 2838 without fastmap support. On typical flash devices the whole fastmap 2839 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2840 2841 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2842 Set this parameter to enable fastmap automatically on images 2843 without a fastmap. 2844 default: 0 2845 2846 CONFIG_MTD_UBI_FM_DEBUG 2847 Enable UBI fastmap debug 2848 default: 0 2849 2850- UBIFS support 2851 CONFIG_UBIFS_SILENCE_MSG 2852 2853 Make the verbose messages from UBIFS stop printing. This leaves 2854 warnings and errors enabled. 2855 2856- SPL framework 2857 CONFIG_SPL 2858 Enable building of SPL globally. 2859 2860 CONFIG_SPL_LDSCRIPT 2861 LDSCRIPT for linking the SPL binary. 2862 2863 CONFIG_SPL_MAX_FOOTPRINT 2864 Maximum size in memory allocated to the SPL, BSS included. 2865 When defined, the linker checks that the actual memory 2866 used by SPL from _start to __bss_end does not exceed it. 2867 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2868 must not be both defined at the same time. 2869 2870 CONFIG_SPL_MAX_SIZE 2871 Maximum size of the SPL image (text, data, rodata, and 2872 linker lists sections), BSS excluded. 2873 When defined, the linker checks that the actual size does 2874 not exceed it. 2875 2876 CONFIG_SPL_TEXT_BASE 2877 TEXT_BASE for linking the SPL binary. 2878 2879 CONFIG_SPL_RELOC_TEXT_BASE 2880 Address to relocate to. If unspecified, this is equal to 2881 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2882 2883 CONFIG_SPL_BSS_START_ADDR 2884 Link address for the BSS within the SPL binary. 2885 2886 CONFIG_SPL_BSS_MAX_SIZE 2887 Maximum size in memory allocated to the SPL BSS. 2888 When defined, the linker checks that the actual memory used 2889 by SPL from __bss_start to __bss_end does not exceed it. 2890 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2891 must not be both defined at the same time. 2892 2893 CONFIG_SPL_STACK 2894 Adress of the start of the stack SPL will use 2895 2896 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2897 When defined, SPL will panic() if the image it has 2898 loaded does not have a signature. 2899 Defining this is useful when code which loads images 2900 in SPL cannot guarantee that absolutely all read errors 2901 will be caught. 2902 An example is the LPC32XX MLC NAND driver, which will 2903 consider that a completely unreadable NAND block is bad, 2904 and thus should be skipped silently. 2905 2906 CONFIG_SPL_RELOC_STACK 2907 Adress of the start of the stack SPL will use after 2908 relocation. If unspecified, this is equal to 2909 CONFIG_SPL_STACK. 2910 2911 CONFIG_SYS_SPL_MALLOC_START 2912 Starting address of the malloc pool used in SPL. 2913 When this option is set the full malloc is used in SPL and 2914 it is set up by spl_init() and before that, the simple malloc() 2915 can be used if CONFIG_SYS_MALLOC_F is defined. 2916 2917 CONFIG_SYS_SPL_MALLOC_SIZE 2918 The size of the malloc pool used in SPL. 2919 2920 CONFIG_SPL_FRAMEWORK 2921 Enable the SPL framework under common/. This framework 2922 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2923 NAND loading of the Linux Kernel. 2924 2925 CONFIG_SPL_OS_BOOT 2926 Enable booting directly to an OS from SPL. 2927 See also: doc/README.falcon 2928 2929 CONFIG_SPL_DISPLAY_PRINT 2930 For ARM, enable an optional function to print more information 2931 about the running system. 2932 2933 CONFIG_SPL_INIT_MINIMAL 2934 Arch init code should be built for a very small image 2935 2936 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2937 Partition on the MMC to load U-Boot from when the MMC is being 2938 used in raw mode 2939 2940 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2941 Sector to load kernel uImage from when MMC is being 2942 used in raw mode (for Falcon mode) 2943 2944 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2945 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2946 Sector and number of sectors to load kernel argument 2947 parameters from when MMC is being used in raw mode 2948 (for falcon mode) 2949 2950 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2951 Partition on the MMC to load U-Boot from when the MMC is being 2952 used in fs mode 2953 2954 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2955 Filename to read to load U-Boot when reading from filesystem 2956 2957 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2958 Filename to read to load kernel uImage when reading 2959 from filesystem (for Falcon mode) 2960 2961 CONFIG_SPL_FS_LOAD_ARGS_NAME 2962 Filename to read to load kernel argument parameters 2963 when reading from filesystem (for Falcon mode) 2964 2965 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2966 Set this for NAND SPL on PPC mpc83xx targets, so that 2967 start.S waits for the rest of the SPL to load before 2968 continuing (the hardware starts execution after just 2969 loading the first page rather than the full 4K). 2970 2971 CONFIG_SPL_SKIP_RELOCATE 2972 Avoid SPL relocation 2973 2974 CONFIG_SPL_NAND_BASE 2975 Include nand_base.c in the SPL. Requires 2976 CONFIG_SPL_NAND_DRIVERS. 2977 2978 CONFIG_SPL_NAND_DRIVERS 2979 SPL uses normal NAND drivers, not minimal drivers. 2980 2981 CONFIG_SPL_NAND_ECC 2982 Include standard software ECC in the SPL 2983 2984 CONFIG_SPL_NAND_SIMPLE 2985 Support for NAND boot using simple NAND drivers that 2986 expose the cmd_ctrl() interface. 2987 2988 CONFIG_SPL_UBI 2989 Support for a lightweight UBI (fastmap) scanner and 2990 loader 2991 2992 CONFIG_SPL_NAND_RAW_ONLY 2993 Support to boot only raw u-boot.bin images. Use this only 2994 if you need to save space. 2995 2996 CONFIG_SPL_COMMON_INIT_DDR 2997 Set for common ddr init with serial presence detect in 2998 SPL binary. 2999 3000 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3001 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3002 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3003 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3004 CONFIG_SYS_NAND_ECCBYTES 3005 Defines the size and behavior of the NAND that SPL uses 3006 to read U-Boot 3007 3008 CONFIG_SPL_NAND_BOOT 3009 Add support NAND boot 3010 3011 CONFIG_SYS_NAND_U_BOOT_OFFS 3012 Location in NAND to read U-Boot from 3013 3014 CONFIG_SYS_NAND_U_BOOT_DST 3015 Location in memory to load U-Boot to 3016 3017 CONFIG_SYS_NAND_U_BOOT_SIZE 3018 Size of image to load 3019 3020 CONFIG_SYS_NAND_U_BOOT_START 3021 Entry point in loaded image to jump to 3022 3023 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3024 Define this if you need to first read the OOB and then the 3025 data. This is used, for example, on davinci platforms. 3026 3027 CONFIG_SPL_OMAP3_ID_NAND 3028 Support for an OMAP3-specific set of functions to return the 3029 ID and MFR of the first attached NAND chip, if present. 3030 3031 CONFIG_SPL_RAM_DEVICE 3032 Support for running image already present in ram, in SPL binary 3033 3034 CONFIG_SPL_PAD_TO 3035 Image offset to which the SPL should be padded before appending 3036 the SPL payload. By default, this is defined as 3037 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3038 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3039 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3040 3041 CONFIG_SPL_TARGET 3042 Final target image containing SPL and payload. Some SPLs 3043 use an arch-specific makefile fragment instead, for 3044 example if more than one image needs to be produced. 3045 3046 CONFIG_FIT_SPL_PRINT 3047 Printing information about a FIT image adds quite a bit of 3048 code to SPL. So this is normally disabled in SPL. Use this 3049 option to re-enable it. This will affect the output of the 3050 bootm command when booting a FIT image. 3051 3052- TPL framework 3053 CONFIG_TPL 3054 Enable building of TPL globally. 3055 3056 CONFIG_TPL_PAD_TO 3057 Image offset to which the TPL should be padded before appending 3058 the TPL payload. By default, this is defined as 3059 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3060 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3061 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3062 3063- Interrupt support (PPC): 3064 3065 There are common interrupt_init() and timer_interrupt() 3066 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3067 for CPU specific initialization. interrupt_init_cpu() 3068 should set decrementer_count to appropriate value. If 3069 CPU resets decrementer automatically after interrupt 3070 (ppc4xx) it should set decrementer_count to zero. 3071 timer_interrupt() calls timer_interrupt_cpu() for CPU 3072 specific handling. If board has watchdog / status_led 3073 / other_activity_monitor it works automatically from 3074 general timer_interrupt(). 3075 3076 3077Board initialization settings: 3078------------------------------ 3079 3080During Initialization u-boot calls a number of board specific functions 3081to allow the preparation of board specific prerequisites, e.g. pin setup 3082before drivers are initialized. To enable these callbacks the 3083following configuration macros have to be defined. Currently this is 3084architecture specific, so please check arch/your_architecture/lib/board.c 3085typically in board_init_f() and board_init_r(). 3086 3087- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3088- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3089- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3090- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3091 3092Configuration Settings: 3093----------------------- 3094 3095- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3096 Optionally it can be defined to support 64-bit memory commands. 3097 3098- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3099 undefine this when you're short of memory. 3100 3101- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3102 width of the commands listed in the 'help' command output. 3103 3104- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3105 prompt for user input. 3106 3107- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3108 3109- CONFIG_SYS_PBSIZE: Buffer size for Console output 3110 3111- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3112 3113- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3114 the application (usually a Linux kernel) when it is 3115 booted 3116 3117- CONFIG_SYS_BAUDRATE_TABLE: 3118 List of legal baudrate settings for this board. 3119 3120- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3121 Begin and End addresses of the area used by the 3122 simple memory test. 3123 3124- CONFIG_SYS_ALT_MEMTEST: 3125 Enable an alternate, more extensive memory test. 3126 3127- CONFIG_SYS_MEMTEST_SCRATCH: 3128 Scratch address used by the alternate memory test 3129 You only need to set this if address zero isn't writeable 3130 3131- CONFIG_SYS_MEM_RESERVE_SECURE 3132 Only implemented for ARMv8 for now. 3133 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3134 is substracted from total RAM and won't be reported to OS. 3135 This memory can be used as secure memory. A variable 3136 gd->arch.secure_ram is used to track the location. In systems 3137 the RAM base is not zero, or RAM is divided into banks, 3138 this variable needs to be recalcuated to get the address. 3139 3140- CONFIG_SYS_MEM_TOP_HIDE: 3141 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3142 this specified memory area will get subtracted from the top 3143 (end) of RAM and won't get "touched" at all by U-Boot. By 3144 fixing up gd->ram_size the Linux kernel should gets passed 3145 the now "corrected" memory size and won't touch it either. 3146 This should work for arch/ppc and arch/powerpc. Only Linux 3147 board ports in arch/powerpc with bootwrapper support that 3148 recalculate the memory size from the SDRAM controller setup 3149 will have to get fixed in Linux additionally. 3150 3151 This option can be used as a workaround for the 440EPx/GRx 3152 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3153 be touched. 3154 3155 WARNING: Please make sure that this value is a multiple of 3156 the Linux page size (normally 4k). If this is not the case, 3157 then the end address of the Linux memory will be located at a 3158 non page size aligned address and this could cause major 3159 problems. 3160 3161- CONFIG_SYS_LOADS_BAUD_CHANGE: 3162 Enable temporary baudrate change while serial download 3163 3164- CONFIG_SYS_SDRAM_BASE: 3165 Physical start address of SDRAM. _Must_ be 0 here. 3166 3167- CONFIG_SYS_FLASH_BASE: 3168 Physical start address of Flash memory. 3169 3170- CONFIG_SYS_MONITOR_BASE: 3171 Physical start address of boot monitor code (set by 3172 make config files to be same as the text base address 3173 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3174 CONFIG_SYS_FLASH_BASE when booting from flash. 3175 3176- CONFIG_SYS_MONITOR_LEN: 3177 Size of memory reserved for monitor code, used to 3178 determine _at_compile_time_ (!) if the environment is 3179 embedded within the U-Boot image, or in a separate 3180 flash sector. 3181 3182- CONFIG_SYS_MALLOC_LEN: 3183 Size of DRAM reserved for malloc() use. 3184 3185- CONFIG_SYS_MALLOC_F_LEN 3186 Size of the malloc() pool for use before relocation. If 3187 this is defined, then a very simple malloc() implementation 3188 will become available before relocation. The address is just 3189 below the global data, and the stack is moved down to make 3190 space. 3191 3192 This feature allocates regions with increasing addresses 3193 within the region. calloc() is supported, but realloc() 3194 is not available. free() is supported but does nothing. 3195 The memory will be freed (or in fact just forgotten) when 3196 U-Boot relocates itself. 3197 3198- CONFIG_SYS_MALLOC_SIMPLE 3199 Provides a simple and small malloc() and calloc() for those 3200 boards which do not use the full malloc in SPL (which is 3201 enabled with CONFIG_SYS_SPL_MALLOC_START). 3202 3203- CONFIG_SYS_NONCACHED_MEMORY: 3204 Size of non-cached memory area. This area of memory will be 3205 typically located right below the malloc() area and mapped 3206 uncached in the MMU. This is useful for drivers that would 3207 otherwise require a lot of explicit cache maintenance. For 3208 some drivers it's also impossible to properly maintain the 3209 cache. For example if the regions that need to be flushed 3210 are not a multiple of the cache-line size, *and* padding 3211 cannot be allocated between the regions to align them (i.e. 3212 if the HW requires a contiguous array of regions, and the 3213 size of each region is not cache-aligned), then a flush of 3214 one region may result in overwriting data that hardware has 3215 written to another region in the same cache-line. This can 3216 happen for example in network drivers where descriptors for 3217 buffers are typically smaller than the CPU cache-line (e.g. 3218 16 bytes vs. 32 or 64 bytes). 3219 3220 Non-cached memory is only supported on 32-bit ARM at present. 3221 3222- CONFIG_SYS_BOOTM_LEN: 3223 Normally compressed uImages are limited to an 3224 uncompressed size of 8 MBytes. If this is not enough, 3225 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3226 to adjust this setting to your needs. 3227 3228- CONFIG_SYS_BOOTMAPSZ: 3229 Maximum size of memory mapped by the startup code of 3230 the Linux kernel; all data that must be processed by 3231 the Linux kernel (bd_info, boot arguments, FDT blob if 3232 used) must be put below this limit, unless "bootm_low" 3233 environment variable is defined and non-zero. In such case 3234 all data for the Linux kernel must be between "bootm_low" 3235 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3236 variable "bootm_mapsize" will override the value of 3237 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3238 then the value in "bootm_size" will be used instead. 3239 3240- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3241 Enable initrd_high functionality. If defined then the 3242 initrd_high feature is enabled and the bootm ramdisk subcommand 3243 is enabled. 3244 3245- CONFIG_SYS_BOOT_GET_CMDLINE: 3246 Enables allocating and saving kernel cmdline in space between 3247 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3248 3249- CONFIG_SYS_BOOT_GET_KBD: 3250 Enables allocating and saving a kernel copy of the bd_info in 3251 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3252 3253- CONFIG_SYS_MAX_FLASH_BANKS: 3254 Max number of Flash memory banks 3255 3256- CONFIG_SYS_MAX_FLASH_SECT: 3257 Max number of sectors on a Flash chip 3258 3259- CONFIG_SYS_FLASH_ERASE_TOUT: 3260 Timeout for Flash erase operations (in ms) 3261 3262- CONFIG_SYS_FLASH_WRITE_TOUT: 3263 Timeout for Flash write operations (in ms) 3264 3265- CONFIG_SYS_FLASH_LOCK_TOUT 3266 Timeout for Flash set sector lock bit operation (in ms) 3267 3268- CONFIG_SYS_FLASH_UNLOCK_TOUT 3269 Timeout for Flash clear lock bits operation (in ms) 3270 3271- CONFIG_SYS_FLASH_PROTECTION 3272 If defined, hardware flash sectors protection is used 3273 instead of U-Boot software protection. 3274 3275- CONFIG_SYS_DIRECT_FLASH_TFTP: 3276 3277 Enable TFTP transfers directly to flash memory; 3278 without this option such a download has to be 3279 performed in two steps: (1) download to RAM, and (2) 3280 copy from RAM to flash. 3281 3282 The two-step approach is usually more reliable, since 3283 you can check if the download worked before you erase 3284 the flash, but in some situations (when system RAM is 3285 too limited to allow for a temporary copy of the 3286 downloaded image) this option may be very useful. 3287 3288- CONFIG_SYS_FLASH_CFI: 3289 Define if the flash driver uses extra elements in the 3290 common flash structure for storing flash geometry. 3291 3292- CONFIG_FLASH_CFI_DRIVER 3293 This option also enables the building of the cfi_flash driver 3294 in the drivers directory 3295 3296- CONFIG_FLASH_CFI_MTD 3297 This option enables the building of the cfi_mtd driver 3298 in the drivers directory. The driver exports CFI flash 3299 to the MTD layer. 3300 3301- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3302 Use buffered writes to flash. 3303 3304- CONFIG_FLASH_SPANSION_S29WS_N 3305 s29ws-n MirrorBit flash has non-standard addresses for buffered 3306 write commands. 3307 3308- CONFIG_SYS_FLASH_QUIET_TEST 3309 If this option is defined, the common CFI flash doesn't 3310 print it's warning upon not recognized FLASH banks. This 3311 is useful, if some of the configured banks are only 3312 optionally available. 3313 3314- CONFIG_FLASH_SHOW_PROGRESS 3315 If defined (must be an integer), print out countdown 3316 digits and dots. Recommended value: 45 (9..1) for 80 3317 column displays, 15 (3..1) for 40 column displays. 3318 3319- CONFIG_FLASH_VERIFY 3320 If defined, the content of the flash (destination) is compared 3321 against the source after the write operation. An error message 3322 will be printed when the contents are not identical. 3323 Please note that this option is useless in nearly all cases, 3324 since such flash programming errors usually are detected earlier 3325 while unprotecting/erasing/programming. Please only enable 3326 this option if you really know what you are doing. 3327 3328- CONFIG_SYS_RX_ETH_BUFFER: 3329 Defines the number of Ethernet receive buffers. On some 3330 Ethernet controllers it is recommended to set this value 3331 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3332 buffers can be full shortly after enabling the interface 3333 on high Ethernet traffic. 3334 Defaults to 4 if not defined. 3335 3336- CONFIG_ENV_MAX_ENTRIES 3337 3338 Maximum number of entries in the hash table that is used 3339 internally to store the environment settings. The default 3340 setting is supposed to be generous and should work in most 3341 cases. This setting can be used to tune behaviour; see 3342 lib/hashtable.c for details. 3343 3344- CONFIG_ENV_FLAGS_LIST_DEFAULT 3345- CONFIG_ENV_FLAGS_LIST_STATIC 3346 Enable validation of the values given to environment variables when 3347 calling env set. Variables can be restricted to only decimal, 3348 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3349 the variables can also be restricted to IP address or MAC address. 3350 3351 The format of the list is: 3352 type_attribute = [s|d|x|b|i|m] 3353 access_attribute = [a|r|o|c] 3354 attributes = type_attribute[access_attribute] 3355 entry = variable_name[:attributes] 3356 list = entry[,list] 3357 3358 The type attributes are: 3359 s - String (default) 3360 d - Decimal 3361 x - Hexadecimal 3362 b - Boolean ([1yYtT|0nNfF]) 3363 i - IP address 3364 m - MAC address 3365 3366 The access attributes are: 3367 a - Any (default) 3368 r - Read-only 3369 o - Write-once 3370 c - Change-default 3371 3372 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3373 Define this to a list (string) to define the ".flags" 3374 environment variable in the default or embedded environment. 3375 3376 - CONFIG_ENV_FLAGS_LIST_STATIC 3377 Define this to a list (string) to define validation that 3378 should be done if an entry is not found in the ".flags" 3379 environment variable. To override a setting in the static 3380 list, simply add an entry for the same variable name to the 3381 ".flags" variable. 3382 3383 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3384 regular expression. This allows multiple variables to define the same 3385 flags without explicitly listing them for each variable. 3386 3387- CONFIG_ENV_ACCESS_IGNORE_FORCE 3388 If defined, don't allow the -f switch to env set override variable 3389 access flags. 3390 3391- CONFIG_USE_STDINT 3392 If stdint.h is available with your toolchain you can define this 3393 option to enable it. You can provide option 'USE_STDINT=1' when 3394 building U-Boot to enable this. 3395 3396The following definitions that deal with the placement and management 3397of environment data (variable area); in general, we support the 3398following configurations: 3399 3400- CONFIG_BUILD_ENVCRC: 3401 3402 Builds up envcrc with the target environment so that external utils 3403 may easily extract it and embed it in final U-Boot images. 3404 3405BE CAREFUL! The first access to the environment happens quite early 3406in U-Boot initialization (when we try to get the setting of for the 3407console baudrate). You *MUST* have mapped your NVRAM area then, or 3408U-Boot will hang. 3409 3410Please note that even with NVRAM we still use a copy of the 3411environment in RAM: we could work on NVRAM directly, but we want to 3412keep settings there always unmodified except somebody uses "saveenv" 3413to save the current settings. 3414 3415BE CAREFUL! For some special cases, the local device can not use 3416"saveenv" command. For example, the local device will get the 3417environment stored in a remote NOR flash by SRIO or PCIE link, 3418but it can not erase, write this NOR flash by SRIO or PCIE interface. 3419 3420- CONFIG_NAND_ENV_DST 3421 3422 Defines address in RAM to which the nand_spl code should copy the 3423 environment. If redundant environment is used, it will be copied to 3424 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3425 3426Please note that the environment is read-only until the monitor 3427has been relocated to RAM and a RAM copy of the environment has been 3428created; also, when using EEPROM you will have to use getenv_f() 3429until then to read environment variables. 3430 3431The environment is protected by a CRC32 checksum. Before the monitor 3432is relocated into RAM, as a result of a bad CRC you will be working 3433with the compiled-in default environment - *silently*!!! [This is 3434necessary, because the first environment variable we need is the 3435"baudrate" setting for the console - if we have a bad CRC, we don't 3436have any device yet where we could complain.] 3437 3438Note: once the monitor has been relocated, then it will complain if 3439the default environment is used; a new CRC is computed as soon as you 3440use the "saveenv" command to store a valid environment. 3441 3442- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3443 Echo the inverted Ethernet link state to the fault LED. 3444 3445 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3446 also needs to be defined. 3447 3448- CONFIG_SYS_FAULT_MII_ADDR: 3449 MII address of the PHY to check for the Ethernet link state. 3450 3451- CONFIG_NS16550_MIN_FUNCTIONS: 3452 Define this if you desire to only have use of the NS16550_init 3453 and NS16550_putc functions for the serial driver located at 3454 drivers/serial/ns16550.c. This option is useful for saving 3455 space for already greatly restricted images, including but not 3456 limited to NAND_SPL configurations. 3457 3458- CONFIG_DISPLAY_BOARDINFO 3459 Display information about the board that U-Boot is running on 3460 when U-Boot starts up. The board function checkboard() is called 3461 to do this. 3462 3463- CONFIG_DISPLAY_BOARDINFO_LATE 3464 Similar to the previous option, but display this information 3465 later, once stdio is running and output goes to the LCD, if 3466 present. 3467 3468- CONFIG_BOARD_SIZE_LIMIT: 3469 Maximum size of the U-Boot image. When defined, the 3470 build system checks that the actual size does not 3471 exceed it. 3472 3473Low Level (hardware related) configuration options: 3474--------------------------------------------------- 3475 3476- CONFIG_SYS_CACHELINE_SIZE: 3477 Cache Line Size of the CPU. 3478 3479- CONFIG_SYS_CCSRBAR_DEFAULT: 3480 Default (power-on reset) physical address of CCSR on Freescale 3481 PowerPC SOCs. 3482 3483- CONFIG_SYS_CCSRBAR: 3484 Virtual address of CCSR. On a 32-bit build, this is typically 3485 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3486 3487- CONFIG_SYS_CCSRBAR_PHYS: 3488 Physical address of CCSR. CCSR can be relocated to a new 3489 physical address, if desired. In this case, this macro should 3490 be set to that address. Otherwise, it should be set to the 3491 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3492 is typically relocated on 36-bit builds. It is recommended 3493 that this macro be defined via the _HIGH and _LOW macros: 3494 3495 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3496 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3497 3498- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3499 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3500 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3501 used in assembly code, so it must not contain typecasts or 3502 integer size suffixes (e.g. "ULL"). 3503 3504- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3505 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3506 used in assembly code, so it must not contain typecasts or 3507 integer size suffixes (e.g. "ULL"). 3508 3509- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3510 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3511 forced to a value that ensures that CCSR is not relocated. 3512 3513- Floppy Disk Support: 3514 CONFIG_SYS_FDC_DRIVE_NUMBER 3515 3516 the default drive number (default value 0) 3517 3518 CONFIG_SYS_ISA_IO_STRIDE 3519 3520 defines the spacing between FDC chipset registers 3521 (default value 1) 3522 3523 CONFIG_SYS_ISA_IO_OFFSET 3524 3525 defines the offset of register from address. It 3526 depends on which part of the data bus is connected to 3527 the FDC chipset. (default value 0) 3528 3529 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3530 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3531 default value. 3532 3533 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3534 fdc_hw_init() is called at the beginning of the FDC 3535 setup. fdc_hw_init() must be provided by the board 3536 source code. It is used to make hardware-dependent 3537 initializations. 3538 3539- CONFIG_IDE_AHB: 3540 Most IDE controllers were designed to be connected with PCI 3541 interface. Only few of them were designed for AHB interface. 3542 When software is doing ATA command and data transfer to 3543 IDE devices through IDE-AHB controller, some additional 3544 registers accessing to these kind of IDE-AHB controller 3545 is required. 3546 3547- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3548 DO NOT CHANGE unless you know exactly what you're 3549 doing! (11-4) [MPC8xx systems only] 3550 3551- CONFIG_SYS_INIT_RAM_ADDR: 3552 3553 Start address of memory area that can be used for 3554 initial data and stack; please note that this must be 3555 writable memory that is working WITHOUT special 3556 initialization, i. e. you CANNOT use normal RAM which 3557 will become available only after programming the 3558 memory controller and running certain initialization 3559 sequences. 3560 3561 U-Boot uses the following memory types: 3562 - MPC8xx: IMMR (internal memory of the CPU) 3563 3564- CONFIG_SYS_GBL_DATA_OFFSET: 3565 3566 Offset of the initial data structure in the memory 3567 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3568 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3569 data is located at the end of the available space 3570 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3571 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3572 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3573 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3574 3575 Note: 3576 On the MPC824X (or other systems that use the data 3577 cache for initial memory) the address chosen for 3578 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3579 point to an otherwise UNUSED address space between 3580 the top of RAM and the start of the PCI space. 3581 3582- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3583 3584- CONFIG_SYS_OR_TIMING_SDRAM: 3585 SDRAM timing 3586 3587- CONFIG_SYS_MAMR_PTA: 3588 periodic timer for refresh 3589 3590- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3591 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3592 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3593 CONFIG_SYS_BR1_PRELIM: 3594 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3595 3596- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3597 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3598 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3599 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3600 3601- CONFIG_PCI_ENUM_ONLY 3602 Only scan through and get the devices on the buses. 3603 Don't do any setup work, presumably because someone or 3604 something has already done it, and we don't need to do it 3605 a second time. Useful for platforms that are pre-booted 3606 by coreboot or similar. 3607 3608- CONFIG_PCI_INDIRECT_BRIDGE: 3609 Enable support for indirect PCI bridges. 3610 3611- CONFIG_SYS_SRIO: 3612 Chip has SRIO or not 3613 3614- CONFIG_SRIO1: 3615 Board has SRIO 1 port available 3616 3617- CONFIG_SRIO2: 3618 Board has SRIO 2 port available 3619 3620- CONFIG_SRIO_PCIE_BOOT_MASTER 3621 Board can support master function for Boot from SRIO and PCIE 3622 3623- CONFIG_SYS_SRIOn_MEM_VIRT: 3624 Virtual Address of SRIO port 'n' memory region 3625 3626- CONFIG_SYS_SRIOn_MEM_PHYS: 3627 Physical Address of SRIO port 'n' memory region 3628 3629- CONFIG_SYS_SRIOn_MEM_SIZE: 3630 Size of SRIO port 'n' memory region 3631 3632- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3633 Defined to tell the NAND controller that the NAND chip is using 3634 a 16 bit bus. 3635 Not all NAND drivers use this symbol. 3636 Example of drivers that use it: 3637 - drivers/mtd/nand/ndfc.c 3638 - drivers/mtd/nand/mxc_nand.c 3639 3640- CONFIG_SYS_NDFC_EBC0_CFG 3641 Sets the EBC0_CFG register for the NDFC. If not defined 3642 a default value will be used. 3643 3644- CONFIG_SPD_EEPROM 3645 Get DDR timing information from an I2C EEPROM. Common 3646 with pluggable memory modules such as SODIMMs 3647 3648 SPD_EEPROM_ADDRESS 3649 I2C address of the SPD EEPROM 3650 3651- CONFIG_SYS_SPD_BUS_NUM 3652 If SPD EEPROM is on an I2C bus other than the first 3653 one, specify here. Note that the value must resolve 3654 to something your driver can deal with. 3655 3656- CONFIG_SYS_DDR_RAW_TIMING 3657 Get DDR timing information from other than SPD. Common with 3658 soldered DDR chips onboard without SPD. DDR raw timing 3659 parameters are extracted from datasheet and hard-coded into 3660 header files or board specific files. 3661 3662- CONFIG_FSL_DDR_INTERACTIVE 3663 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3664 3665- CONFIG_FSL_DDR_SYNC_REFRESH 3666 Enable sync of refresh for multiple controllers. 3667 3668- CONFIG_FSL_DDR_BIST 3669 Enable built-in memory test for Freescale DDR controllers. 3670 3671- CONFIG_SYS_83XX_DDR_USES_CS0 3672 Only for 83xx systems. If specified, then DDR should 3673 be configured using CS0 and CS1 instead of CS2 and CS3. 3674 3675- CONFIG_RMII 3676 Enable RMII mode for all FECs. 3677 Note that this is a global option, we can't 3678 have one FEC in standard MII mode and another in RMII mode. 3679 3680- CONFIG_CRC32_VERIFY 3681 Add a verify option to the crc32 command. 3682 The syntax is: 3683 3684 => crc32 -v <address> <count> <crc32> 3685 3686 Where address/count indicate a memory area 3687 and crc32 is the correct crc32 which the 3688 area should have. 3689 3690- CONFIG_LOOPW 3691 Add the "loopw" memory command. This only takes effect if 3692 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3693 3694- CONFIG_MX_CYCLIC 3695 Add the "mdc" and "mwc" memory commands. These are cyclic 3696 "md/mw" commands. 3697 Examples: 3698 3699 => mdc.b 10 4 500 3700 This command will print 4 bytes (10,11,12,13) each 500 ms. 3701 3702 => mwc.l 100 12345678 10 3703 This command will write 12345678 to address 100 all 10 ms. 3704 3705 This only takes effect if the memory commands are activated 3706 globally (CONFIG_CMD_MEMORY). 3707 3708- CONFIG_SKIP_LOWLEVEL_INIT 3709 [ARM, NDS32, MIPS only] If this variable is defined, then certain 3710 low level initializations (like setting up the memory 3711 controller) are omitted and/or U-Boot does not 3712 relocate itself into RAM. 3713 3714 Normally this variable MUST NOT be defined. The only 3715 exception is when U-Boot is loaded (to RAM) by some 3716 other boot loader or by a debugger which performs 3717 these initializations itself. 3718 3719- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3720 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3721 to be skipped. The normal CP15 init (such as enabling the 3722 instruction cache) is still performed. 3723 3724- CONFIG_SPL_BUILD 3725 Modifies the behaviour of start.S when compiling a loader 3726 that is executed before the actual U-Boot. E.g. when 3727 compiling a NAND SPL. 3728 3729- CONFIG_TPL_BUILD 3730 Modifies the behaviour of start.S when compiling a loader 3731 that is executed after the SPL and before the actual U-Boot. 3732 It is loaded by the SPL. 3733 3734- CONFIG_SYS_MPC85XX_NO_RESETVEC 3735 Only for 85xx systems. If this variable is specified, the section 3736 .resetvec is not kept and the section .bootpg is placed in the 3737 previous 4k of the .text section. 3738 3739- CONFIG_ARCH_MAP_SYSMEM 3740 Generally U-Boot (and in particular the md command) uses 3741 effective address. It is therefore not necessary to regard 3742 U-Boot address as virtual addresses that need to be translated 3743 to physical addresses. However, sandbox requires this, since 3744 it maintains its own little RAM buffer which contains all 3745 addressable memory. This option causes some memory accesses 3746 to be mapped through map_sysmem() / unmap_sysmem(). 3747 3748- CONFIG_X86_RESET_VECTOR 3749 If defined, the x86 reset vector code is included. This is not 3750 needed when U-Boot is running from Coreboot. 3751 3752- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3753 Enables the RTC32K OSC on AM33xx based plattforms 3754 3755- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3756 Option to disable subpage write in NAND driver 3757 driver that uses this: 3758 drivers/mtd/nand/davinci_nand.c 3759 3760Freescale QE/FMAN Firmware Support: 3761----------------------------------- 3762 3763The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3764loading of "firmware", which is encoded in the QE firmware binary format. 3765This firmware often needs to be loaded during U-Boot booting, so macros 3766are used to identify the storage device (NOR flash, SPI, etc) and the address 3767within that device. 3768 3769- CONFIG_SYS_FMAN_FW_ADDR 3770 The address in the storage device where the FMAN microcode is located. The 3771 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3772 is also specified. 3773 3774- CONFIG_SYS_QE_FW_ADDR 3775 The address in the storage device where the QE microcode is located. The 3776 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3777 is also specified. 3778 3779- CONFIG_SYS_QE_FMAN_FW_LENGTH 3780 The maximum possible size of the firmware. The firmware binary format 3781 has a field that specifies the actual size of the firmware, but it 3782 might not be possible to read any part of the firmware unless some 3783 local storage is allocated to hold the entire firmware first. 3784 3785- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3786 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3787 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3788 virtual address in NOR flash. 3789 3790- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3791 Specifies that QE/FMAN firmware is located in NAND flash. 3792 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3793 3794- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3795 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3796 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3797 3798- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3799 Specifies that QE/FMAN firmware is located in the remote (master) 3800 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3801 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3802 window->master inbound window->master LAW->the ucode address in 3803 master's memory space. 3804 3805Freescale Layerscape Management Complex Firmware Support: 3806--------------------------------------------------------- 3807The Freescale Layerscape Management Complex (MC) supports the loading of 3808"firmware". 3809This firmware often needs to be loaded during U-Boot booting, so macros 3810are used to identify the storage device (NOR flash, SPI, etc) and the address 3811within that device. 3812 3813- CONFIG_FSL_MC_ENET 3814 Enable the MC driver for Layerscape SoCs. 3815 3816Freescale Layerscape Debug Server Support: 3817------------------------------------------- 3818The Freescale Layerscape Debug Server Support supports the loading of 3819"Debug Server firmware" and triggering SP boot-rom. 3820This firmware often needs to be loaded during U-Boot booting. 3821 3822- CONFIG_SYS_MC_RSV_MEM_ALIGN 3823 Define alignment of reserved memory MC requires 3824 3825Reproducible builds 3826------------------- 3827 3828In order to achieve reproducible builds, timestamps used in the U-Boot build 3829process have to be set to a fixed value. 3830 3831This is done using the SOURCE_DATE_EPOCH environment variable. 3832SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3833option for U-Boot or an environment variable in U-Boot. 3834 3835SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3836 3837Building the Software: 3838====================== 3839 3840Building U-Boot has been tested in several native build environments 3841and in many different cross environments. Of course we cannot support 3842all possibly existing versions of cross development tools in all 3843(potentially obsolete) versions. In case of tool chain problems we 3844recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3845which is extensively used to build and test U-Boot. 3846 3847If you are not using a native environment, it is assumed that you 3848have GNU cross compiling tools available in your path. In this case, 3849you must set the environment variable CROSS_COMPILE in your shell. 3850Note that no changes to the Makefile or any other source files are 3851necessary. For example using the ELDK on a 4xx CPU, please enter: 3852 3853 $ CROSS_COMPILE=ppc_4xx- 3854 $ export CROSS_COMPILE 3855 3856Note: If you wish to generate Windows versions of the utilities in 3857 the tools directory you can use the MinGW toolchain 3858 (http://www.mingw.org). Set your HOST tools to the MinGW 3859 toolchain and execute 'make tools'. For example: 3860 3861 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3862 3863 Binaries such as tools/mkimage.exe will be created which can 3864 be executed on computers running Windows. 3865 3866U-Boot is intended to be simple to build. After installing the 3867sources you must configure U-Boot for one specific board type. This 3868is done by typing: 3869 3870 make NAME_defconfig 3871 3872where "NAME_defconfig" is the name of one of the existing configu- 3873rations; see boards.cfg for supported names. 3874 3875Note: for some board special configuration names may exist; check if 3876 additional information is available from the board vendor; for 3877 instance, the TQM823L systems are available without (standard) 3878 or with LCD support. You can select such additional "features" 3879 when choosing the configuration, i. e. 3880 3881 make TQM823L_defconfig 3882 - will configure for a plain TQM823L, i. e. no LCD support 3883 3884 make TQM823L_LCD_defconfig 3885 - will configure for a TQM823L with U-Boot console on LCD 3886 3887 etc. 3888 3889 3890Finally, type "make all", and you should get some working U-Boot 3891images ready for download to / installation on your system: 3892 3893- "u-boot.bin" is a raw binary image 3894- "u-boot" is an image in ELF binary format 3895- "u-boot.srec" is in Motorola S-Record format 3896 3897By default the build is performed locally and the objects are saved 3898in the source directory. One of the two methods can be used to change 3899this behavior and build U-Boot to some external directory: 3900 39011. Add O= to the make command line invocations: 3902 3903 make O=/tmp/build distclean 3904 make O=/tmp/build NAME_defconfig 3905 make O=/tmp/build all 3906 39072. Set environment variable KBUILD_OUTPUT to point to the desired location: 3908 3909 export KBUILD_OUTPUT=/tmp/build 3910 make distclean 3911 make NAME_defconfig 3912 make all 3913 3914Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3915variable. 3916 3917 3918Please be aware that the Makefiles assume you are using GNU make, so 3919for instance on NetBSD you might need to use "gmake" instead of 3920native "make". 3921 3922 3923If the system board that you have is not listed, then you will need 3924to port U-Boot to your hardware platform. To do this, follow these 3925steps: 3926 39271. Create a new directory to hold your board specific code. Add any 3928 files you need. In your board directory, you will need at least 3929 the "Makefile" and a "<board>.c". 39302. Create a new configuration file "include/configs/<board>.h" for 3931 your board. 39323. If you're porting U-Boot to a new CPU, then also create a new 3933 directory to hold your CPU specific code. Add any files you need. 39344. Run "make <board>_defconfig" with your new name. 39355. Type "make", and you should get a working "u-boot.srec" file 3936 to be installed on your target system. 39376. Debug and solve any problems that might arise. 3938 [Of course, this last step is much harder than it sounds.] 3939 3940 3941Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3942============================================================== 3943 3944If you have modified U-Boot sources (for instance added a new board 3945or support for new devices, a new CPU, etc.) you are expected to 3946provide feedback to the other developers. The feedback normally takes 3947the form of a "patch", i. e. a context diff against a certain (latest 3948official or latest in the git repository) version of U-Boot sources. 3949 3950But before you submit such a patch, please verify that your modifi- 3951cation did not break existing code. At least make sure that *ALL* of 3952the supported boards compile WITHOUT ANY compiler warnings. To do so, 3953just run the buildman script (tools/buildman/buildman), which will 3954configure and build U-Boot for ALL supported system. Be warned, this 3955will take a while. Please see the buildman README, or run 'buildman -H' 3956for documentation. 3957 3958 3959See also "U-Boot Porting Guide" below. 3960 3961 3962Monitor Commands - Overview: 3963============================ 3964 3965go - start application at address 'addr' 3966run - run commands in an environment variable 3967bootm - boot application image from memory 3968bootp - boot image via network using BootP/TFTP protocol 3969bootz - boot zImage from memory 3970tftpboot- boot image via network using TFTP protocol 3971 and env variables "ipaddr" and "serverip" 3972 (and eventually "gatewayip") 3973tftpput - upload a file via network using TFTP protocol 3974rarpboot- boot image via network using RARP/TFTP protocol 3975diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3976loads - load S-Record file over serial line 3977loadb - load binary file over serial line (kermit mode) 3978md - memory display 3979mm - memory modify (auto-incrementing) 3980nm - memory modify (constant address) 3981mw - memory write (fill) 3982cp - memory copy 3983cmp - memory compare 3984crc32 - checksum calculation 3985i2c - I2C sub-system 3986sspi - SPI utility commands 3987base - print or set address offset 3988printenv- print environment variables 3989setenv - set environment variables 3990saveenv - save environment variables to persistent storage 3991protect - enable or disable FLASH write protection 3992erase - erase FLASH memory 3993flinfo - print FLASH memory information 3994nand - NAND memory operations (see doc/README.nand) 3995bdinfo - print Board Info structure 3996iminfo - print header information for application image 3997coninfo - print console devices and informations 3998ide - IDE sub-system 3999loop - infinite loop on address range 4000loopw - infinite write loop on address range 4001mtest - simple RAM test 4002icache - enable or disable instruction cache 4003dcache - enable or disable data cache 4004reset - Perform RESET of the CPU 4005echo - echo args to console 4006version - print monitor version 4007help - print online help 4008? - alias for 'help' 4009 4010 4011Monitor Commands - Detailed Description: 4012======================================== 4013 4014TODO. 4015 4016For now: just type "help <command>". 4017 4018 4019Environment Variables: 4020====================== 4021 4022U-Boot supports user configuration using Environment Variables which 4023can be made persistent by saving to Flash memory. 4024 4025Environment Variables are set using "setenv", printed using 4026"printenv", and saved to Flash using "saveenv". Using "setenv" 4027without a value can be used to delete a variable from the 4028environment. As long as you don't save the environment you are 4029working with an in-memory copy. In case the Flash area containing the 4030environment is erased by accident, a default environment is provided. 4031 4032Some configuration options can be set using Environment Variables. 4033 4034List of environment variables (most likely not complete): 4035 4036 baudrate - see CONFIG_BAUDRATE 4037 4038 bootdelay - see CONFIG_BOOTDELAY 4039 4040 bootcmd - see CONFIG_BOOTCOMMAND 4041 4042 bootargs - Boot arguments when booting an RTOS image 4043 4044 bootfile - Name of the image to load with TFTP 4045 4046 bootm_low - Memory range available for image processing in the bootm 4047 command can be restricted. This variable is given as 4048 a hexadecimal number and defines lowest address allowed 4049 for use by the bootm command. See also "bootm_size" 4050 environment variable. Address defined by "bootm_low" is 4051 also the base of the initial memory mapping for the Linux 4052 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4053 bootm_mapsize. 4054 4055 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4056 This variable is given as a hexadecimal number and it 4057 defines the size of the memory region starting at base 4058 address bootm_low that is accessible by the Linux kernel 4059 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4060 as the default value if it is defined, and bootm_size is 4061 used otherwise. 4062 4063 bootm_size - Memory range available for image processing in the bootm 4064 command can be restricted. This variable is given as 4065 a hexadecimal number and defines the size of the region 4066 allowed for use by the bootm command. See also "bootm_low" 4067 environment variable. 4068 4069 updatefile - Location of the software update file on a TFTP server, used 4070 by the automatic software update feature. Please refer to 4071 documentation in doc/README.update for more details. 4072 4073 autoload - if set to "no" (any string beginning with 'n'), 4074 "bootp" will just load perform a lookup of the 4075 configuration from the BOOTP server, but not try to 4076 load any image using TFTP 4077 4078 autostart - if set to "yes", an image loaded using the "bootp", 4079 "rarpboot", "tftpboot" or "diskboot" commands will 4080 be automatically started (by internally calling 4081 "bootm") 4082 4083 If set to "no", a standalone image passed to the 4084 "bootm" command will be copied to the load address 4085 (and eventually uncompressed), but NOT be started. 4086 This can be used to load and uncompress arbitrary 4087 data. 4088 4089 fdt_high - if set this restricts the maximum address that the 4090 flattened device tree will be copied into upon boot. 4091 For example, if you have a system with 1 GB memory 4092 at physical address 0x10000000, while Linux kernel 4093 only recognizes the first 704 MB as low memory, you 4094 may need to set fdt_high as 0x3C000000 to have the 4095 device tree blob be copied to the maximum address 4096 of the 704 MB low memory, so that Linux kernel can 4097 access it during the boot procedure. 4098 4099 If this is set to the special value 0xFFFFFFFF then 4100 the fdt will not be copied at all on boot. For this 4101 to work it must reside in writable memory, have 4102 sufficient padding on the end of it for u-boot to 4103 add the information it needs into it, and the memory 4104 must be accessible by the kernel. 4105 4106 fdtcontroladdr- if set this is the address of the control flattened 4107 device tree used by U-Boot when CONFIG_OF_CONTROL is 4108 defined. 4109 4110 i2cfast - (PPC405GP|PPC405EP only) 4111 if set to 'y' configures Linux I2C driver for fast 4112 mode (400kHZ). This environment variable is used in 4113 initialization code. So, for changes to be effective 4114 it must be saved and board must be reset. 4115 4116 initrd_high - restrict positioning of initrd images: 4117 If this variable is not set, initrd images will be 4118 copied to the highest possible address in RAM; this 4119 is usually what you want since it allows for 4120 maximum initrd size. If for some reason you want to 4121 make sure that the initrd image is loaded below the 4122 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4123 variable to a value of "no" or "off" or "0". 4124 Alternatively, you can set it to a maximum upper 4125 address to use (U-Boot will still check that it 4126 does not overwrite the U-Boot stack and data). 4127 4128 For instance, when you have a system with 16 MB 4129 RAM, and want to reserve 4 MB from use by Linux, 4130 you can do this by adding "mem=12M" to the value of 4131 the "bootargs" variable. However, now you must make 4132 sure that the initrd image is placed in the first 4133 12 MB as well - this can be done with 4134 4135 setenv initrd_high 00c00000 4136 4137 If you set initrd_high to 0xFFFFFFFF, this is an 4138 indication to U-Boot that all addresses are legal 4139 for the Linux kernel, including addresses in flash 4140 memory. In this case U-Boot will NOT COPY the 4141 ramdisk at all. This may be useful to reduce the 4142 boot time on your system, but requires that this 4143 feature is supported by your Linux kernel. 4144 4145 ipaddr - IP address; needed for tftpboot command 4146 4147 loadaddr - Default load address for commands like "bootp", 4148 "rarpboot", "tftpboot", "loadb" or "diskboot" 4149 4150 loads_echo - see CONFIG_LOADS_ECHO 4151 4152 serverip - TFTP server IP address; needed for tftpboot command 4153 4154 bootretry - see CONFIG_BOOT_RETRY_TIME 4155 4156 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4157 4158 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4159 4160 ethprime - controls which interface is used first. 4161 4162 ethact - controls which interface is currently active. 4163 For example you can do the following 4164 4165 => setenv ethact FEC 4166 => ping 192.168.0.1 # traffic sent on FEC 4167 => setenv ethact SCC 4168 => ping 10.0.0.1 # traffic sent on SCC 4169 4170 ethrotate - When set to "no" U-Boot does not go through all 4171 available network interfaces. 4172 It just stays at the currently selected interface. 4173 4174 netretry - When set to "no" each network operation will 4175 either succeed or fail without retrying. 4176 When set to "once" the network operation will 4177 fail when all the available network interfaces 4178 are tried once without success. 4179 Useful on scripts which control the retry operation 4180 themselves. 4181 4182 npe_ucode - set load address for the NPE microcode 4183 4184 silent_linux - If set then Linux will be told to boot silently, by 4185 changing the console to be empty. If "yes" it will be 4186 made silent. If "no" it will not be made silent. If 4187 unset, then it will be made silent if the U-Boot console 4188 is silent. 4189 4190 tftpsrcp - If this is set, the value is used for TFTP's 4191 UDP source port. 4192 4193 tftpdstp - If this is set, the value is used for TFTP's UDP 4194 destination port instead of the Well Know Port 69. 4195 4196 tftpblocksize - Block size to use for TFTP transfers; if not set, 4197 we use the TFTP server's default block size 4198 4199 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4200 seconds, minimum value is 1000 = 1 second). Defines 4201 when a packet is considered to be lost so it has to 4202 be retransmitted. The default is 5000 = 5 seconds. 4203 Lowering this value may make downloads succeed 4204 faster in networks with high packet loss rates or 4205 with unreliable TFTP servers. 4206 4207 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4208 unit, minimum value = 0). Defines how many timeouts 4209 can happen during a single file transfer before that 4210 transfer is aborted. The default is 10, and 0 means 4211 'no timeouts allowed'. Increasing this value may help 4212 downloads succeed with high packet loss rates, or with 4213 unreliable TFTP servers or client hardware. 4214 4215 vlan - When set to a value < 4095 the traffic over 4216 Ethernet is encapsulated/received over 802.1q 4217 VLAN tagged frames. 4218 4219 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4220 Unsigned value, in milliseconds. If not set, the period will 4221 be either the default (28000), or a value based on 4222 CONFIG_NET_RETRY_COUNT, if defined. This value has 4223 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4224 4225The following image location variables contain the location of images 4226used in booting. The "Image" column gives the role of the image and is 4227not an environment variable name. The other columns are environment 4228variable names. "File Name" gives the name of the file on a TFTP 4229server, "RAM Address" gives the location in RAM the image will be 4230loaded to, and "Flash Location" gives the image's address in NOR 4231flash or offset in NAND flash. 4232 4233*Note* - these variables don't have to be defined for all boards, some 4234boards currently use other variables for these purposes, and some 4235boards use these variables for other purposes. 4236 4237Image File Name RAM Address Flash Location 4238----- --------- ----------- -------------- 4239u-boot u-boot u-boot_addr_r u-boot_addr 4240Linux kernel bootfile kernel_addr_r kernel_addr 4241device tree blob fdtfile fdt_addr_r fdt_addr 4242ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4243 4244The following environment variables may be used and automatically 4245updated by the network boot commands ("bootp" and "rarpboot"), 4246depending the information provided by your boot server: 4247 4248 bootfile - see above 4249 dnsip - IP address of your Domain Name Server 4250 dnsip2 - IP address of your secondary Domain Name Server 4251 gatewayip - IP address of the Gateway (Router) to use 4252 hostname - Target hostname 4253 ipaddr - see above 4254 netmask - Subnet Mask 4255 rootpath - Pathname of the root filesystem on the NFS server 4256 serverip - see above 4257 4258 4259There are two special Environment Variables: 4260 4261 serial# - contains hardware identification information such 4262 as type string and/or serial number 4263 ethaddr - Ethernet address 4264 4265These variables can be set only once (usually during manufacturing of 4266the board). U-Boot refuses to delete or overwrite these variables 4267once they have been set once. 4268 4269 4270Further special Environment Variables: 4271 4272 ver - Contains the U-Boot version string as printed 4273 with the "version" command. This variable is 4274 readonly (see CONFIG_VERSION_VARIABLE). 4275 4276 4277Please note that changes to some configuration parameters may take 4278only effect after the next boot (yes, that's just like Windoze :-). 4279 4280 4281Callback functions for environment variables: 4282--------------------------------------------- 4283 4284For some environment variables, the behavior of u-boot needs to change 4285when their values are changed. This functionality allows functions to 4286be associated with arbitrary variables. On creation, overwrite, or 4287deletion, the callback will provide the opportunity for some side 4288effect to happen or for the change to be rejected. 4289 4290The callbacks are named and associated with a function using the 4291U_BOOT_ENV_CALLBACK macro in your board or driver code. 4292 4293These callbacks are associated with variables in one of two ways. The 4294static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4295in the board configuration to a string that defines a list of 4296associations. The list must be in the following format: 4297 4298 entry = variable_name[:callback_name] 4299 list = entry[,list] 4300 4301If the callback name is not specified, then the callback is deleted. 4302Spaces are also allowed anywhere in the list. 4303 4304Callbacks can also be associated by defining the ".callbacks" variable 4305with the same list format above. Any association in ".callbacks" will 4306override any association in the static list. You can define 4307CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4308".callbacks" environment variable in the default or embedded environment. 4309 4310If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4311regular expression. This allows multiple variables to be connected to 4312the same callback without explicitly listing them all out. 4313 4314 4315Command Line Parsing: 4316===================== 4317 4318There are two different command line parsers available with U-Boot: 4319the old "simple" one, and the much more powerful "hush" shell: 4320 4321Old, simple command line parser: 4322-------------------------------- 4323 4324- supports environment variables (through setenv / saveenv commands) 4325- several commands on one line, separated by ';' 4326- variable substitution using "... ${name} ..." syntax 4327- special characters ('$', ';') can be escaped by prefixing with '\', 4328 for example: 4329 setenv bootcmd bootm \${address} 4330- You can also escape text by enclosing in single apostrophes, for example: 4331 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4332 4333Hush shell: 4334----------- 4335 4336- similar to Bourne shell, with control structures like 4337 if...then...else...fi, for...do...done; while...do...done, 4338 until...do...done, ... 4339- supports environment ("global") variables (through setenv / saveenv 4340 commands) and local shell variables (through standard shell syntax 4341 "name=value"); only environment variables can be used with "run" 4342 command 4343 4344General rules: 4345-------------- 4346 4347(1) If a command line (or an environment variable executed by a "run" 4348 command) contains several commands separated by semicolon, and 4349 one of these commands fails, then the remaining commands will be 4350 executed anyway. 4351 4352(2) If you execute several variables with one call to run (i. e. 4353 calling run with a list of variables as arguments), any failing 4354 command will cause "run" to terminate, i. e. the remaining 4355 variables are not executed. 4356 4357Note for Redundant Ethernet Interfaces: 4358======================================= 4359 4360Some boards come with redundant Ethernet interfaces; U-Boot supports 4361such configurations and is capable of automatic selection of a 4362"working" interface when needed. MAC assignment works as follows: 4363 4364Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4365MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4366"eth1addr" (=>eth1), "eth2addr", ... 4367 4368If the network interface stores some valid MAC address (for instance 4369in SROM), this is used as default address if there is NO correspon- 4370ding setting in the environment; if the corresponding environment 4371variable is set, this overrides the settings in the card; that means: 4372 4373o If the SROM has a valid MAC address, and there is no address in the 4374 environment, the SROM's address is used. 4375 4376o If there is no valid address in the SROM, and a definition in the 4377 environment exists, then the value from the environment variable is 4378 used. 4379 4380o If both the SROM and the environment contain a MAC address, and 4381 both addresses are the same, this MAC address is used. 4382 4383o If both the SROM and the environment contain a MAC address, and the 4384 addresses differ, the value from the environment is used and a 4385 warning is printed. 4386 4387o If neither SROM nor the environment contain a MAC address, an error 4388 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4389 a random, locally-assigned MAC is used. 4390 4391If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4392will be programmed into hardware as part of the initialization process. This 4393may be skipped by setting the appropriate 'ethmacskip' environment variable. 4394The naming convention is as follows: 4395"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4396 4397Image Formats: 4398============== 4399 4400U-Boot is capable of booting (and performing other auxiliary operations on) 4401images in two formats: 4402 4403New uImage format (FIT) 4404----------------------- 4405 4406Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4407to Flattened Device Tree). It allows the use of images with multiple 4408components (several kernels, ramdisks, etc.), with contents protected by 4409SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4410 4411 4412Old uImage format 4413----------------- 4414 4415Old image format is based on binary files which can be basically anything, 4416preceded by a special header; see the definitions in include/image.h for 4417details; basically, the header defines the following image properties: 4418 4419* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4420 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4421 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4422 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4423 INTEGRITY). 4424* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4425 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4426 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4427* Compression Type (uncompressed, gzip, bzip2) 4428* Load Address 4429* Entry Point 4430* Image Name 4431* Image Timestamp 4432 4433The header is marked by a special Magic Number, and both the header 4434and the data portions of the image are secured against corruption by 4435CRC32 checksums. 4436 4437 4438Linux Support: 4439============== 4440 4441Although U-Boot should support any OS or standalone application 4442easily, the main focus has always been on Linux during the design of 4443U-Boot. 4444 4445U-Boot includes many features that so far have been part of some 4446special "boot loader" code within the Linux kernel. Also, any 4447"initrd" images to be used are no longer part of one big Linux image; 4448instead, kernel and "initrd" are separate images. This implementation 4449serves several purposes: 4450 4451- the same features can be used for other OS or standalone 4452 applications (for instance: using compressed images to reduce the 4453 Flash memory footprint) 4454 4455- it becomes much easier to port new Linux kernel versions because 4456 lots of low-level, hardware dependent stuff are done by U-Boot 4457 4458- the same Linux kernel image can now be used with different "initrd" 4459 images; of course this also means that different kernel images can 4460 be run with the same "initrd". This makes testing easier (you don't 4461 have to build a new "zImage.initrd" Linux image when you just 4462 change a file in your "initrd"). Also, a field-upgrade of the 4463 software is easier now. 4464 4465 4466Linux HOWTO: 4467============ 4468 4469Porting Linux to U-Boot based systems: 4470--------------------------------------- 4471 4472U-Boot cannot save you from doing all the necessary modifications to 4473configure the Linux device drivers for use with your target hardware 4474(no, we don't intend to provide a full virtual machine interface to 4475Linux :-). 4476 4477But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4478 4479Just make sure your machine specific header file (for instance 4480include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4481Information structure as we define in include/asm-<arch>/u-boot.h, 4482and make sure that your definition of IMAP_ADDR uses the same value 4483as your U-Boot configuration in CONFIG_SYS_IMMR. 4484 4485Note that U-Boot now has a driver model, a unified model for drivers. 4486If you are adding a new driver, plumb it into driver model. If there 4487is no uclass available, you are encouraged to create one. See 4488doc/driver-model. 4489 4490 4491Configuring the Linux kernel: 4492----------------------------- 4493 4494No specific requirements for U-Boot. Make sure you have some root 4495device (initial ramdisk, NFS) for your target system. 4496 4497 4498Building a Linux Image: 4499----------------------- 4500 4501With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4502not used. If you use recent kernel source, a new build target 4503"uImage" will exist which automatically builds an image usable by 4504U-Boot. Most older kernels also have support for a "pImage" target, 4505which was introduced for our predecessor project PPCBoot and uses a 4506100% compatible format. 4507 4508Example: 4509 4510 make TQM850L_defconfig 4511 make oldconfig 4512 make dep 4513 make uImage 4514 4515The "uImage" build target uses a special tool (in 'tools/mkimage') to 4516encapsulate a compressed Linux kernel image with header information, 4517CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4518 4519* build a standard "vmlinux" kernel image (in ELF binary format): 4520 4521* convert the kernel into a raw binary image: 4522 4523 ${CROSS_COMPILE}-objcopy -O binary \ 4524 -R .note -R .comment \ 4525 -S vmlinux linux.bin 4526 4527* compress the binary image: 4528 4529 gzip -9 linux.bin 4530 4531* package compressed binary image for U-Boot: 4532 4533 mkimage -A ppc -O linux -T kernel -C gzip \ 4534 -a 0 -e 0 -n "Linux Kernel Image" \ 4535 -d linux.bin.gz uImage 4536 4537 4538The "mkimage" tool can also be used to create ramdisk images for use 4539with U-Boot, either separated from the Linux kernel image, or 4540combined into one file. "mkimage" encapsulates the images with a 64 4541byte header containing information about target architecture, 4542operating system, image type, compression method, entry points, time 4543stamp, CRC32 checksums, etc. 4544 4545"mkimage" can be called in two ways: to verify existing images and 4546print the header information, or to build new images. 4547 4548In the first form (with "-l" option) mkimage lists the information 4549contained in the header of an existing U-Boot image; this includes 4550checksum verification: 4551 4552 tools/mkimage -l image 4553 -l ==> list image header information 4554 4555The second form (with "-d" option) is used to build a U-Boot image 4556from a "data file" which is used as image payload: 4557 4558 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4559 -n name -d data_file image 4560 -A ==> set architecture to 'arch' 4561 -O ==> set operating system to 'os' 4562 -T ==> set image type to 'type' 4563 -C ==> set compression type 'comp' 4564 -a ==> set load address to 'addr' (hex) 4565 -e ==> set entry point to 'ep' (hex) 4566 -n ==> set image name to 'name' 4567 -d ==> use image data from 'datafile' 4568 4569Right now, all Linux kernels for PowerPC systems use the same load 4570address (0x00000000), but the entry point address depends on the 4571kernel version: 4572 4573- 2.2.x kernels have the entry point at 0x0000000C, 4574- 2.3.x and later kernels have the entry point at 0x00000000. 4575 4576So a typical call to build a U-Boot image would read: 4577 4578 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4579 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4580 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4581 > examples/uImage.TQM850L 4582 Image Name: 2.4.4 kernel for TQM850L 4583 Created: Wed Jul 19 02:34:59 2000 4584 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4585 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4586 Load Address: 0x00000000 4587 Entry Point: 0x00000000 4588 4589To verify the contents of the image (or check for corruption): 4590 4591 -> tools/mkimage -l examples/uImage.TQM850L 4592 Image Name: 2.4.4 kernel for TQM850L 4593 Created: Wed Jul 19 02:34:59 2000 4594 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4595 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4596 Load Address: 0x00000000 4597 Entry Point: 0x00000000 4598 4599NOTE: for embedded systems where boot time is critical you can trade 4600speed for memory and install an UNCOMPRESSED image instead: this 4601needs more space in Flash, but boots much faster since it does not 4602need to be uncompressed: 4603 4604 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4605 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4606 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4607 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4608 > examples/uImage.TQM850L-uncompressed 4609 Image Name: 2.4.4 kernel for TQM850L 4610 Created: Wed Jul 19 02:34:59 2000 4611 Image Type: PowerPC Linux Kernel Image (uncompressed) 4612 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4613 Load Address: 0x00000000 4614 Entry Point: 0x00000000 4615 4616 4617Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4618when your kernel is intended to use an initial ramdisk: 4619 4620 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4621 > -A ppc -O linux -T ramdisk -C gzip \ 4622 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4623 Image Name: Simple Ramdisk Image 4624 Created: Wed Jan 12 14:01:50 2000 4625 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4626 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4627 Load Address: 0x00000000 4628 Entry Point: 0x00000000 4629 4630The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4631option performs the converse operation of the mkimage's second form (the "-d" 4632option). Given an image built by mkimage, the dumpimage extracts a "data file" 4633from the image: 4634 4635 tools/dumpimage -i image -T type -p position data_file 4636 -i ==> extract from the 'image' a specific 'data_file' 4637 -T ==> set image type to 'type' 4638 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4639 4640 4641Installing a Linux Image: 4642------------------------- 4643 4644To downloading a U-Boot image over the serial (console) interface, 4645you must convert the image to S-Record format: 4646 4647 objcopy -I binary -O srec examples/image examples/image.srec 4648 4649The 'objcopy' does not understand the information in the U-Boot 4650image header, so the resulting S-Record file will be relative to 4651address 0x00000000. To load it to a given address, you need to 4652specify the target address as 'offset' parameter with the 'loads' 4653command. 4654 4655Example: install the image to address 0x40100000 (which on the 4656TQM8xxL is in the first Flash bank): 4657 4658 => erase 40100000 401FFFFF 4659 4660 .......... done 4661 Erased 8 sectors 4662 4663 => loads 40100000 4664 ## Ready for S-Record download ... 4665 ~>examples/image.srec 4666 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4667 ... 4668 15989 15990 15991 15992 4669 [file transfer complete] 4670 [connected] 4671 ## Start Addr = 0x00000000 4672 4673 4674You can check the success of the download using the 'iminfo' command; 4675this includes a checksum verification so you can be sure no data 4676corruption happened: 4677 4678 => imi 40100000 4679 4680 ## Checking Image at 40100000 ... 4681 Image Name: 2.2.13 for initrd on TQM850L 4682 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4683 Data Size: 335725 Bytes = 327 kB = 0 MB 4684 Load Address: 00000000 4685 Entry Point: 0000000c 4686 Verifying Checksum ... OK 4687 4688 4689Boot Linux: 4690----------- 4691 4692The "bootm" command is used to boot an application that is stored in 4693memory (RAM or Flash). In case of a Linux kernel image, the contents 4694of the "bootargs" environment variable is passed to the kernel as 4695parameters. You can check and modify this variable using the 4696"printenv" and "setenv" commands: 4697 4698 4699 => printenv bootargs 4700 bootargs=root=/dev/ram 4701 4702 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4703 4704 => printenv bootargs 4705 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4706 4707 => bootm 40020000 4708 ## Booting Linux kernel at 40020000 ... 4709 Image Name: 2.2.13 for NFS on TQM850L 4710 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4711 Data Size: 381681 Bytes = 372 kB = 0 MB 4712 Load Address: 00000000 4713 Entry Point: 0000000c 4714 Verifying Checksum ... OK 4715 Uncompressing Kernel Image ... OK 4716 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 4717 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4718 time_init: decrementer frequency = 187500000/60 4719 Calibrating delay loop... 49.77 BogoMIPS 4720 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4721 ... 4722 4723If you want to boot a Linux kernel with initial RAM disk, you pass 4724the memory addresses of both the kernel and the initrd image (PPBCOOT 4725format!) to the "bootm" command: 4726 4727 => imi 40100000 40200000 4728 4729 ## Checking Image at 40100000 ... 4730 Image Name: 2.2.13 for initrd on TQM850L 4731 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4732 Data Size: 335725 Bytes = 327 kB = 0 MB 4733 Load Address: 00000000 4734 Entry Point: 0000000c 4735 Verifying Checksum ... OK 4736 4737 ## Checking Image at 40200000 ... 4738 Image Name: Simple Ramdisk Image 4739 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4740 Data Size: 566530 Bytes = 553 kB = 0 MB 4741 Load Address: 00000000 4742 Entry Point: 00000000 4743 Verifying Checksum ... OK 4744 4745 => bootm 40100000 40200000 4746 ## Booting Linux kernel at 40100000 ... 4747 Image Name: 2.2.13 for initrd on TQM850L 4748 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4749 Data Size: 335725 Bytes = 327 kB = 0 MB 4750 Load Address: 00000000 4751 Entry Point: 0000000c 4752 Verifying Checksum ... OK 4753 Uncompressing Kernel Image ... OK 4754 ## Loading RAMDisk Image at 40200000 ... 4755 Image Name: Simple Ramdisk Image 4756 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4757 Data Size: 566530 Bytes = 553 kB = 0 MB 4758 Load Address: 00000000 4759 Entry Point: 00000000 4760 Verifying Checksum ... OK 4761 Loading Ramdisk ... OK 4762 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 4763 Boot arguments: root=/dev/ram 4764 time_init: decrementer frequency = 187500000/60 4765 Calibrating delay loop... 49.77 BogoMIPS 4766 ... 4767 RAMDISK: Compressed image found at block 0 4768 VFS: Mounted root (ext2 filesystem). 4769 4770 bash# 4771 4772Boot Linux and pass a flat device tree: 4773----------- 4774 4775First, U-Boot must be compiled with the appropriate defines. See the section 4776titled "Linux Kernel Interface" above for a more in depth explanation. The 4777following is an example of how to start a kernel and pass an updated 4778flat device tree: 4779 4780=> print oftaddr 4781oftaddr=0x300000 4782=> print oft 4783oft=oftrees/mpc8540ads.dtb 4784=> tftp $oftaddr $oft 4785Speed: 1000, full duplex 4786Using TSEC0 device 4787TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4788Filename 'oftrees/mpc8540ads.dtb'. 4789Load address: 0x300000 4790Loading: # 4791done 4792Bytes transferred = 4106 (100a hex) 4793=> tftp $loadaddr $bootfile 4794Speed: 1000, full duplex 4795Using TSEC0 device 4796TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4797Filename 'uImage'. 4798Load address: 0x200000 4799Loading:############ 4800done 4801Bytes transferred = 1029407 (fb51f hex) 4802=> print loadaddr 4803loadaddr=200000 4804=> print oftaddr 4805oftaddr=0x300000 4806=> bootm $loadaddr - $oftaddr 4807## Booting image at 00200000 ... 4808 Image Name: Linux-2.6.17-dirty 4809 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4810 Data Size: 1029343 Bytes = 1005.2 kB 4811 Load Address: 00000000 4812 Entry Point: 00000000 4813 Verifying Checksum ... OK 4814 Uncompressing Kernel Image ... OK 4815Booting using flat device tree at 0x300000 4816Using MPC85xx ADS machine description 4817Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4818[snip] 4819 4820 4821More About U-Boot Image Types: 4822------------------------------ 4823 4824U-Boot supports the following image types: 4825 4826 "Standalone Programs" are directly runnable in the environment 4827 provided by U-Boot; it is expected that (if they behave 4828 well) you can continue to work in U-Boot after return from 4829 the Standalone Program. 4830 "OS Kernel Images" are usually images of some Embedded OS which 4831 will take over control completely. Usually these programs 4832 will install their own set of exception handlers, device 4833 drivers, set up the MMU, etc. - this means, that you cannot 4834 expect to re-enter U-Boot except by resetting the CPU. 4835 "RAMDisk Images" are more or less just data blocks, and their 4836 parameters (address, size) are passed to an OS kernel that is 4837 being started. 4838 "Multi-File Images" contain several images, typically an OS 4839 (Linux) kernel image and one or more data images like 4840 RAMDisks. This construct is useful for instance when you want 4841 to boot over the network using BOOTP etc., where the boot 4842 server provides just a single image file, but you want to get 4843 for instance an OS kernel and a RAMDisk image. 4844 4845 "Multi-File Images" start with a list of image sizes, each 4846 image size (in bytes) specified by an "uint32_t" in network 4847 byte order. This list is terminated by an "(uint32_t)0". 4848 Immediately after the terminating 0 follow the images, one by 4849 one, all aligned on "uint32_t" boundaries (size rounded up to 4850 a multiple of 4 bytes). 4851 4852 "Firmware Images" are binary images containing firmware (like 4853 U-Boot or FPGA images) which usually will be programmed to 4854 flash memory. 4855 4856 "Script files" are command sequences that will be executed by 4857 U-Boot's command interpreter; this feature is especially 4858 useful when you configure U-Boot to use a real shell (hush) 4859 as command interpreter. 4860 4861Booting the Linux zImage: 4862------------------------- 4863 4864On some platforms, it's possible to boot Linux zImage. This is done 4865using the "bootz" command. The syntax of "bootz" command is the same 4866as the syntax of "bootm" command. 4867 4868Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4869kernel with raw initrd images. The syntax is slightly different, the 4870address of the initrd must be augmented by it's size, in the following 4871format: "<initrd addres>:<initrd size>". 4872 4873 4874Standalone HOWTO: 4875================= 4876 4877One of the features of U-Boot is that you can dynamically load and 4878run "standalone" applications, which can use some resources of 4879U-Boot like console I/O functions or interrupt services. 4880 4881Two simple examples are included with the sources: 4882 4883"Hello World" Demo: 4884------------------- 4885 4886'examples/hello_world.c' contains a small "Hello World" Demo 4887application; it is automatically compiled when you build U-Boot. 4888It's configured to run at address 0x00040004, so you can play with it 4889like that: 4890 4891 => loads 4892 ## Ready for S-Record download ... 4893 ~>examples/hello_world.srec 4894 1 2 3 4 5 6 7 8 9 10 11 ... 4895 [file transfer complete] 4896 [connected] 4897 ## Start Addr = 0x00040004 4898 4899 => go 40004 Hello World! This is a test. 4900 ## Starting application at 0x00040004 ... 4901 Hello World 4902 argc = 7 4903 argv[0] = "40004" 4904 argv[1] = "Hello" 4905 argv[2] = "World!" 4906 argv[3] = "This" 4907 argv[4] = "is" 4908 argv[5] = "a" 4909 argv[6] = "test." 4910 argv[7] = "<NULL>" 4911 Hit any key to exit ... 4912 4913 ## Application terminated, rc = 0x0 4914 4915Another example, which demonstrates how to register a CPM interrupt 4916handler with the U-Boot code, can be found in 'examples/timer.c'. 4917Here, a CPM timer is set up to generate an interrupt every second. 4918The interrupt service routine is trivial, just printing a '.' 4919character, but this is just a demo program. The application can be 4920controlled by the following keys: 4921 4922 ? - print current values og the CPM Timer registers 4923 b - enable interrupts and start timer 4924 e - stop timer and disable interrupts 4925 q - quit application 4926 4927 => loads 4928 ## Ready for S-Record download ... 4929 ~>examples/timer.srec 4930 1 2 3 4 5 6 7 8 9 10 11 ... 4931 [file transfer complete] 4932 [connected] 4933 ## Start Addr = 0x00040004 4934 4935 => go 40004 4936 ## Starting application at 0x00040004 ... 4937 TIMERS=0xfff00980 4938 Using timer 1 4939 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4940 4941Hit 'b': 4942 [q, b, e, ?] Set interval 1000000 us 4943 Enabling timer 4944Hit '?': 4945 [q, b, e, ?] ........ 4946 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4947Hit '?': 4948 [q, b, e, ?] . 4949 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4950Hit '?': 4951 [q, b, e, ?] . 4952 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4953Hit '?': 4954 [q, b, e, ?] . 4955 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4956Hit 'e': 4957 [q, b, e, ?] ...Stopping timer 4958Hit 'q': 4959 [q, b, e, ?] ## Application terminated, rc = 0x0 4960 4961 4962Minicom warning: 4963================ 4964 4965Over time, many people have reported problems when trying to use the 4966"minicom" terminal emulation program for serial download. I (wd) 4967consider minicom to be broken, and recommend not to use it. Under 4968Unix, I recommend to use C-Kermit for general purpose use (and 4969especially for kermit binary protocol download ("loadb" command), and 4970use "cu" for S-Record download ("loads" command). See 4971http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4972for help with kermit. 4973 4974 4975Nevertheless, if you absolutely want to use it try adding this 4976configuration to your "File transfer protocols" section: 4977 4978 Name Program Name U/D FullScr IO-Red. Multi 4979 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4980 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4981 4982 4983NetBSD Notes: 4984============= 4985 4986Starting at version 0.9.2, U-Boot supports NetBSD both as host 4987(build U-Boot) and target system (boots NetBSD/mpc8xx). 4988 4989Building requires a cross environment; it is known to work on 4990NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4991need gmake since the Makefiles are not compatible with BSD make). 4992Note that the cross-powerpc package does not install include files; 4993attempting to build U-Boot will fail because <machine/ansi.h> is 4994missing. This file has to be installed and patched manually: 4995 4996 # cd /usr/pkg/cross/powerpc-netbsd/include 4997 # mkdir powerpc 4998 # ln -s powerpc machine 4999 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5000 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5001 5002Native builds *don't* work due to incompatibilities between native 5003and U-Boot include files. 5004 5005Booting assumes that (the first part of) the image booted is a 5006stage-2 loader which in turn loads and then invokes the kernel 5007proper. Loader sources will eventually appear in the NetBSD source 5008tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5009meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5010 5011 5012Implementation Internals: 5013========================= 5014 5015The following is not intended to be a complete description of every 5016implementation detail. However, it should help to understand the 5017inner workings of U-Boot and make it easier to port it to custom 5018hardware. 5019 5020 5021Initial Stack, Global Data: 5022--------------------------- 5023 5024The implementation of U-Boot is complicated by the fact that U-Boot 5025starts running out of ROM (flash memory), usually without access to 5026system RAM (because the memory controller is not initialized yet). 5027This means that we don't have writable Data or BSS segments, and BSS 5028is not initialized as zero. To be able to get a C environment working 5029at all, we have to allocate at least a minimal stack. Implementation 5030options for this are defined and restricted by the CPU used: Some CPU 5031models provide on-chip memory (like the IMMR area on MPC8xx and 5032MPC826x processors), on others (parts of) the data cache can be 5033locked as (mis-) used as memory, etc. 5034 5035 Chris Hallinan posted a good summary of these issues to the 5036 U-Boot mailing list: 5037 5038 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5039 From: "Chris Hallinan" <clh@net1plus.com> 5040 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5041 ... 5042 5043 Correct me if I'm wrong, folks, but the way I understand it 5044 is this: Using DCACHE as initial RAM for Stack, etc, does not 5045 require any physical RAM backing up the cache. The cleverness 5046 is that the cache is being used as a temporary supply of 5047 necessary storage before the SDRAM controller is setup. It's 5048 beyond the scope of this list to explain the details, but you 5049 can see how this works by studying the cache architecture and 5050 operation in the architecture and processor-specific manuals. 5051 5052 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5053 is another option for the system designer to use as an 5054 initial stack/RAM area prior to SDRAM being available. Either 5055 option should work for you. Using CS 4 should be fine if your 5056 board designers haven't used it for something that would 5057 cause you grief during the initial boot! It is frequently not 5058 used. 5059 5060 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5061 with your processor/board/system design. The default value 5062 you will find in any recent u-boot distribution in 5063 walnut.h should work for you. I'd set it to a value larger 5064 than your SDRAM module. If you have a 64MB SDRAM module, set 5065 it above 400_0000. Just make sure your board has no resources 5066 that are supposed to respond to that address! That code in 5067 start.S has been around a while and should work as is when 5068 you get the config right. 5069 5070 -Chris Hallinan 5071 DS4.COM, Inc. 5072 5073It is essential to remember this, since it has some impact on the C 5074code for the initialization procedures: 5075 5076* Initialized global data (data segment) is read-only. Do not attempt 5077 to write it. 5078 5079* Do not use any uninitialized global data (or implicitly initialized 5080 as zero data - BSS segment) at all - this is undefined, initiali- 5081 zation is performed later (when relocating to RAM). 5082 5083* Stack space is very limited. Avoid big data buffers or things like 5084 that. 5085 5086Having only the stack as writable memory limits means we cannot use 5087normal global data to share information between the code. But it 5088turned out that the implementation of U-Boot can be greatly 5089simplified by making a global data structure (gd_t) available to all 5090functions. We could pass a pointer to this data as argument to _all_ 5091functions, but this would bloat the code. Instead we use a feature of 5092the GCC compiler (Global Register Variables) to share the data: we 5093place a pointer (gd) to the global data into a register which we 5094reserve for this purpose. 5095 5096When choosing a register for such a purpose we are restricted by the 5097relevant (E)ABI specifications for the current architecture, and by 5098GCC's implementation. 5099 5100For PowerPC, the following registers have specific use: 5101 R1: stack pointer 5102 R2: reserved for system use 5103 R3-R4: parameter passing and return values 5104 R5-R10: parameter passing 5105 R13: small data area pointer 5106 R30: GOT pointer 5107 R31: frame pointer 5108 5109 (U-Boot also uses R12 as internal GOT pointer. r12 5110 is a volatile register so r12 needs to be reset when 5111 going back and forth between asm and C) 5112 5113 ==> U-Boot will use R2 to hold a pointer to the global data 5114 5115 Note: on PPC, we could use a static initializer (since the 5116 address of the global data structure is known at compile time), 5117 but it turned out that reserving a register results in somewhat 5118 smaller code - although the code savings are not that big (on 5119 average for all boards 752 bytes for the whole U-Boot image, 5120 624 text + 127 data). 5121 5122On ARM, the following registers are used: 5123 5124 R0: function argument word/integer result 5125 R1-R3: function argument word 5126 R9: platform specific 5127 R10: stack limit (used only if stack checking is enabled) 5128 R11: argument (frame) pointer 5129 R12: temporary workspace 5130 R13: stack pointer 5131 R14: link register 5132 R15: program counter 5133 5134 ==> U-Boot will use R9 to hold a pointer to the global data 5135 5136 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5137 5138On Nios II, the ABI is documented here: 5139 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5140 5141 ==> U-Boot will use gp to hold a pointer to the global data 5142 5143 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5144 to access small data sections, so gp is free. 5145 5146On NDS32, the following registers are used: 5147 5148 R0-R1: argument/return 5149 R2-R5: argument 5150 R15: temporary register for assembler 5151 R16: trampoline register 5152 R28: frame pointer (FP) 5153 R29: global pointer (GP) 5154 R30: link register (LP) 5155 R31: stack pointer (SP) 5156 PC: program counter (PC) 5157 5158 ==> U-Boot will use R10 to hold a pointer to the global data 5159 5160NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5161or current versions of GCC may "optimize" the code too much. 5162 5163Memory Management: 5164------------------ 5165 5166U-Boot runs in system state and uses physical addresses, i.e. the 5167MMU is not used either for address mapping nor for memory protection. 5168 5169The available memory is mapped to fixed addresses using the memory 5170controller. In this process, a contiguous block is formed for each 5171memory type (Flash, SDRAM, SRAM), even when it consists of several 5172physical memory banks. 5173 5174U-Boot is installed in the first 128 kB of the first Flash bank (on 5175TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5176booting and sizing and initializing DRAM, the code relocates itself 5177to the upper end of DRAM. Immediately below the U-Boot code some 5178memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5179configuration setting]. Below that, a structure with global Board 5180Info data is placed, followed by the stack (growing downward). 5181 5182Additionally, some exception handler code is copied to the low 8 kB 5183of DRAM (0x00000000 ... 0x00001FFF). 5184 5185So a typical memory configuration with 16 MB of DRAM could look like 5186this: 5187 5188 0x0000 0000 Exception Vector code 5189 : 5190 0x0000 1FFF 5191 0x0000 2000 Free for Application Use 5192 : 5193 : 5194 5195 : 5196 : 5197 0x00FB FF20 Monitor Stack (Growing downward) 5198 0x00FB FFAC Board Info Data and permanent copy of global data 5199 0x00FC 0000 Malloc Arena 5200 : 5201 0x00FD FFFF 5202 0x00FE 0000 RAM Copy of Monitor Code 5203 ... eventually: LCD or video framebuffer 5204 ... eventually: pRAM (Protected RAM - unchanged by reset) 5205 0x00FF FFFF [End of RAM] 5206 5207 5208System Initialization: 5209---------------------- 5210 5211In the reset configuration, U-Boot starts at the reset entry point 5212(on most PowerPC systems at address 0x00000100). Because of the reset 5213configuration for CS0# this is a mirror of the on board Flash memory. 5214To be able to re-map memory U-Boot then jumps to its link address. 5215To be able to implement the initialization code in C, a (small!) 5216initial stack is set up in the internal Dual Ported RAM (in case CPUs 5217which provide such a feature like), or in a locked part of the data 5218cache. After that, U-Boot initializes the CPU core, the caches and 5219the SIU. 5220 5221Next, all (potentially) available memory banks are mapped using a 5222preliminary mapping. For example, we put them on 512 MB boundaries 5223(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5224on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5225programmed for SDRAM access. Using the temporary configuration, a 5226simple memory test is run that determines the size of the SDRAM 5227banks. 5228 5229When there is more than one SDRAM bank, and the banks are of 5230different size, the largest is mapped first. For equal size, the first 5231bank (CS2#) is mapped first. The first mapping is always for address 52320x00000000, with any additional banks following immediately to create 5233contiguous memory starting from 0. 5234 5235Then, the monitor installs itself at the upper end of the SDRAM area 5236and allocates memory for use by malloc() and for the global Board 5237Info data; also, the exception vector code is copied to the low RAM 5238pages, and the final stack is set up. 5239 5240Only after this relocation will you have a "normal" C environment; 5241until that you are restricted in several ways, mostly because you are 5242running from ROM, and because the code will have to be relocated to a 5243new address in RAM. 5244 5245 5246U-Boot Porting Guide: 5247---------------------- 5248 5249[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5250list, October 2002] 5251 5252 5253int main(int argc, char *argv[]) 5254{ 5255 sighandler_t no_more_time; 5256 5257 signal(SIGALRM, no_more_time); 5258 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5259 5260 if (available_money > available_manpower) { 5261 Pay consultant to port U-Boot; 5262 return 0; 5263 } 5264 5265 Download latest U-Boot source; 5266 5267 Subscribe to u-boot mailing list; 5268 5269 if (clueless) 5270 email("Hi, I am new to U-Boot, how do I get started?"); 5271 5272 while (learning) { 5273 Read the README file in the top level directory; 5274 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5275 Read applicable doc/*.README; 5276 Read the source, Luke; 5277 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5278 } 5279 5280 if (available_money > toLocalCurrency ($2500)) 5281 Buy a BDI3000; 5282 else 5283 Add a lot of aggravation and time; 5284 5285 if (a similar board exists) { /* hopefully... */ 5286 cp -a board/<similar> board/<myboard> 5287 cp include/configs/<similar>.h include/configs/<myboard>.h 5288 } else { 5289 Create your own board support subdirectory; 5290 Create your own board include/configs/<myboard>.h file; 5291 } 5292 Edit new board/<myboard> files 5293 Edit new include/configs/<myboard>.h 5294 5295 while (!accepted) { 5296 while (!running) { 5297 do { 5298 Add / modify source code; 5299 } until (compiles); 5300 Debug; 5301 if (clueless) 5302 email("Hi, I am having problems..."); 5303 } 5304 Send patch file to the U-Boot email list; 5305 if (reasonable critiques) 5306 Incorporate improvements from email list code review; 5307 else 5308 Defend code as written; 5309 } 5310 5311 return 0; 5312} 5313 5314void no_more_time (int sig) 5315{ 5316 hire_a_guru(); 5317} 5318 5319 5320Coding Standards: 5321----------------- 5322 5323All contributions to U-Boot should conform to the Linux kernel 5324coding style; see the file "Documentation/CodingStyle" and the script 5325"scripts/Lindent" in your Linux kernel source directory. 5326 5327Source files originating from a different project (for example the 5328MTD subsystem) are generally exempt from these guidelines and are not 5329reformatted to ease subsequent migration to newer versions of those 5330sources. 5331 5332Please note that U-Boot is implemented in C (and to some small parts in 5333Assembler); no C++ is used, so please do not use C++ style comments (//) 5334in your code. 5335 5336Please also stick to the following formatting rules: 5337- remove any trailing white space 5338- use TAB characters for indentation and vertical alignment, not spaces 5339- make sure NOT to use DOS '\r\n' line feeds 5340- do not add more than 2 consecutive empty lines to source files 5341- do not add trailing empty lines to source files 5342 5343Submissions which do not conform to the standards may be returned 5344with a request to reformat the changes. 5345 5346 5347Submitting Patches: 5348------------------- 5349 5350Since the number of patches for U-Boot is growing, we need to 5351establish some rules. Submissions which do not conform to these rules 5352may be rejected, even when they contain important and valuable stuff. 5353 5354Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5355 5356Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5357see http://lists.denx.de/mailman/listinfo/u-boot 5358 5359When you send a patch, please include the following information with 5360it: 5361 5362* For bug fixes: a description of the bug and how your patch fixes 5363 this bug. Please try to include a way of demonstrating that the 5364 patch actually fixes something. 5365 5366* For new features: a description of the feature and your 5367 implementation. 5368 5369* A CHANGELOG entry as plaintext (separate from the patch) 5370 5371* For major contributions, add a MAINTAINERS file with your 5372 information and associated file and directory references. 5373 5374* When you add support for a new board, don't forget to add a 5375 maintainer e-mail address to the boards.cfg file, too. 5376 5377* If your patch adds new configuration options, don't forget to 5378 document these in the README file. 5379 5380* The patch itself. If you are using git (which is *strongly* 5381 recommended) you can easily generate the patch using the 5382 "git format-patch". If you then use "git send-email" to send it to 5383 the U-Boot mailing list, you will avoid most of the common problems 5384 with some other mail clients. 5385 5386 If you cannot use git, use "diff -purN OLD NEW". If your version of 5387 diff does not support these options, then get the latest version of 5388 GNU diff. 5389 5390 The current directory when running this command shall be the parent 5391 directory of the U-Boot source tree (i. e. please make sure that 5392 your patch includes sufficient directory information for the 5393 affected files). 5394 5395 We prefer patches as plain text. MIME attachments are discouraged, 5396 and compressed attachments must not be used. 5397 5398* If one logical set of modifications affects or creates several 5399 files, all these changes shall be submitted in a SINGLE patch file. 5400 5401* Changesets that contain different, unrelated modifications shall be 5402 submitted as SEPARATE patches, one patch per changeset. 5403 5404 5405Notes: 5406 5407* Before sending the patch, run the buildman script on your patched 5408 source tree and make sure that no errors or warnings are reported 5409 for any of the boards. 5410 5411* Keep your modifications to the necessary minimum: A patch 5412 containing several unrelated changes or arbitrary reformats will be 5413 returned with a request to re-formatting / split it. 5414 5415* If you modify existing code, make sure that your new code does not 5416 add to the memory footprint of the code ;-) Small is beautiful! 5417 When adding new features, these should compile conditionally only 5418 (using #ifdef), and the resulting code with the new feature 5419 disabled must not need more memory than the old code without your 5420 modification. 5421 5422* Remember that there is a size limit of 100 kB per message on the 5423 u-boot mailing list. Bigger patches will be moderated. If they are 5424 reasonable and not too big, they will be acknowledged. But patches 5425 bigger than the size limit should be avoided. 5426