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_PCI * pciinfo 816 CONFIG_CMD_PCMCIA * PCMCIA support 817 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 818 host 819 CONFIG_CMD_PORTIO * Port I/O 820 CONFIG_CMD_READ * Read raw data from partition 821 CONFIG_CMD_REGINFO * Register dump 822 CONFIG_CMD_RUN run command in env variable 823 CONFIG_CMD_SANDBOX * sb command to access sandbox features 824 CONFIG_CMD_SAVES * save S record dump 825 CONFIG_CMD_SDRAM * print SDRAM configuration information 826 (requires CONFIG_CMD_I2C) 827 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 828 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 829 CONFIG_CMD_SOURCE "source" command Support 830 CONFIG_CMD_SPI * SPI serial bus support 831 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 832 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 833 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 834 CONFIG_CMD_TIMER * access to the system tick timer 835 CONFIG_CMD_USB * USB support 836 CONFIG_CMD_CDP * Cisco Discover Protocol support 837 CONFIG_CMD_XIMG Load part of Multi Image 838 CONFIG_CMD_UUID * Generate random UUID or GUID string 839 840 EXAMPLE: If you want all functions except of network 841 support you can write: 842 843 #include "config_cmd_all.h" 844 #undef CONFIG_CMD_NET 845 846 Other Commands: 847 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 848 849 Note: Don't enable the "icache" and "dcache" commands 850 (configuration option CONFIG_CMD_CACHE) unless you know 851 what you (and your U-Boot users) are doing. Data 852 cache cannot be enabled on systems like the 853 8xx (where accesses to the IMMR region must be 854 uncached), and it cannot be disabled on all other 855 systems where we (mis-) use the data cache to hold an 856 initial stack and some data. 857 858 859 XXX - this list needs to get updated! 860 861- Removal of commands 862 If no commands are needed to boot, you can disable 863 CONFIG_CMDLINE to remove them. In this case, the command line 864 will not be available, and when U-Boot wants to execute the 865 boot command (on start-up) it will call board_run_command() 866 instead. This can reduce image size significantly for very 867 simple boot procedures. 868 869- Regular expression support: 870 CONFIG_REGEX 871 If this variable is defined, U-Boot is linked against 872 the SLRE (Super Light Regular Expression) library, 873 which adds regex support to some commands, as for 874 example "env grep" and "setexpr". 875 876- Device tree: 877 CONFIG_OF_CONTROL 878 If this variable is defined, U-Boot will use a device tree 879 to configure its devices, instead of relying on statically 880 compiled #defines in the board file. This option is 881 experimental and only available on a few boards. The device 882 tree is available in the global data as gd->fdt_blob. 883 884 U-Boot needs to get its device tree from somewhere. This can 885 be done using one of the three options below: 886 887 CONFIG_OF_EMBED 888 If this variable is defined, U-Boot will embed a device tree 889 binary in its image. This device tree file should be in the 890 board directory and called <soc>-<board>.dts. The binary file 891 is then picked up in board_init_f() and made available through 892 the global data structure as gd->blob. 893 894 CONFIG_OF_SEPARATE 895 If this variable is defined, U-Boot will build a device tree 896 binary. It will be called u-boot.dtb. Architecture-specific 897 code will locate it at run-time. Generally this works by: 898 899 cat u-boot.bin u-boot.dtb >image.bin 900 901 and in fact, U-Boot does this for you, creating a file called 902 u-boot-dtb.bin which is useful in the common case. You can 903 still use the individual files if you need something more 904 exotic. 905 906 CONFIG_OF_BOARD 907 If this variable is defined, U-Boot will use the device tree 908 provided by the board at runtime instead of embedding one with 909 the image. Only boards defining board_fdt_blob_setup() support 910 this option (see include/fdtdec.h file). 911 912- Watchdog: 913 CONFIG_WATCHDOG 914 If this variable is defined, it enables watchdog 915 support for the SoC. There must be support in the SoC 916 specific code for a watchdog. For the 8xx 917 CPUs, the SIU Watchdog feature is enabled in the SYPCR 918 register. When supported for a specific SoC is 919 available, then no further board specific code should 920 be needed to use it. 921 922 CONFIG_HW_WATCHDOG 923 When using a watchdog circuitry external to the used 924 SoC, then define this variable and provide board 925 specific code for the "hw_watchdog_reset" function. 926 927 CONFIG_AT91_HW_WDT_TIMEOUT 928 specify the timeout in seconds. default 2 seconds. 929 930- U-Boot Version: 931 CONFIG_VERSION_VARIABLE 932 If this variable is defined, an environment variable 933 named "ver" is created by U-Boot showing the U-Boot 934 version as printed by the "version" command. 935 Any change to this variable will be reverted at the 936 next reset. 937 938- Real-Time Clock: 939 940 When CONFIG_CMD_DATE is selected, the type of the RTC 941 has to be selected, too. Define exactly one of the 942 following options: 943 944 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 945 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 946 CONFIG_RTC_MC146818 - use MC146818 RTC 947 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 948 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 949 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 950 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 951 CONFIG_RTC_DS164x - use Dallas DS164x RTC 952 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 953 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 954 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 955 CONFIG_SYS_RV3029_TCR - enable trickle charger on 956 RV3029 RTC. 957 958 Note that if the RTC uses I2C, then the I2C interface 959 must also be configured. See I2C Support, below. 960 961- GPIO Support: 962 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 963 964 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 965 chip-ngpio pairs that tell the PCA953X driver the number of 966 pins supported by a particular chip. 967 968 Note that if the GPIO device uses I2C, then the I2C interface 969 must also be configured. See I2C Support, below. 970 971- I/O tracing: 972 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 973 accesses and can checksum them or write a list of them out 974 to memory. See the 'iotrace' command for details. This is 975 useful for testing device drivers since it can confirm that 976 the driver behaves the same way before and after a code 977 change. Currently this is supported on sandbox and arm. To 978 add support for your architecture, add '#include <iotrace.h>' 979 to the bottom of arch/<arch>/include/asm/io.h and test. 980 981 Example output from the 'iotrace stats' command is below. 982 Note that if the trace buffer is exhausted, the checksum will 983 still continue to operate. 984 985 iotrace is enabled 986 Start: 10000000 (buffer start address) 987 Size: 00010000 (buffer size) 988 Offset: 00000120 (current buffer offset) 989 Output: 10000120 (start + offset) 990 Count: 00000018 (number of trace records) 991 CRC32: 9526fb66 (CRC32 of all trace records) 992 993- Timestamp Support: 994 995 When CONFIG_TIMESTAMP is selected, the timestamp 996 (date and time) of an image is printed by image 997 commands like bootm or iminfo. This option is 998 automatically enabled when you select CONFIG_CMD_DATE . 999 1000- Partition Labels (disklabels) Supported: 1001 Zero or more of the following: 1002 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1003 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1004 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1005 bootloader. Note 2TB partition limit; see 1006 disk/part_efi.c 1007 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1008 1009 If IDE or SCSI support is enabled (CONFIG_IDE or 1010 CONFIG_SCSI) you must configure support for at 1011 least one non-MTD partition type as well. 1012 1013- IDE Reset method: 1014 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1015 board configurations files but used nowhere! 1016 1017 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1018 be performed by calling the function 1019 ide_set_reset(int reset) 1020 which has to be defined in a board specific file 1021 1022- ATAPI Support: 1023 CONFIG_ATAPI 1024 1025 Set this to enable ATAPI support. 1026 1027- LBA48 Support 1028 CONFIG_LBA48 1029 1030 Set this to enable support for disks larger than 137GB 1031 Also look at CONFIG_SYS_64BIT_LBA. 1032 Whithout these , LBA48 support uses 32bit variables and will 'only' 1033 support disks up to 2.1TB. 1034 1035 CONFIG_SYS_64BIT_LBA: 1036 When enabled, makes the IDE subsystem use 64bit sector addresses. 1037 Default is 32bit. 1038 1039- SCSI Support: 1040 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1041 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1042 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1043 maximum numbers of LUNs, SCSI ID's and target 1044 devices. 1045 1046 The environment variable 'scsidevs' is set to the number of 1047 SCSI devices found during the last scan. 1048 1049- NETWORK Support (PCI): 1050 CONFIG_E1000 1051 Support for Intel 8254x/8257x gigabit chips. 1052 1053 CONFIG_E1000_SPI 1054 Utility code for direct access to the SPI bus on Intel 8257x. 1055 This does not do anything useful unless you set at least one 1056 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1057 1058 CONFIG_E1000_SPI_GENERIC 1059 Allow generic access to the SPI bus on the Intel 8257x, for 1060 example with the "sspi" command. 1061 1062 CONFIG_CMD_E1000 1063 Management command for E1000 devices. When used on devices 1064 with SPI support you can reprogram the EEPROM from U-Boot. 1065 1066 CONFIG_EEPRO100 1067 Support for Intel 82557/82559/82559ER chips. 1068 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1069 write routine for first time initialisation. 1070 1071 CONFIG_TULIP 1072 Support for Digital 2114x chips. 1073 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1074 modem chip initialisation (KS8761/QS6611). 1075 1076 CONFIG_NATSEMI 1077 Support for National dp83815 chips. 1078 1079 CONFIG_NS8382X 1080 Support for National dp8382[01] gigabit chips. 1081 1082- NETWORK Support (other): 1083 1084 CONFIG_DRIVER_AT91EMAC 1085 Support for AT91RM9200 EMAC. 1086 1087 CONFIG_RMII 1088 Define this to use reduced MII inteface 1089 1090 CONFIG_DRIVER_AT91EMAC_QUIET 1091 If this defined, the driver is quiet. 1092 The driver doen't show link status messages. 1093 1094 CONFIG_CALXEDA_XGMAC 1095 Support for the Calxeda XGMAC device 1096 1097 CONFIG_LAN91C96 1098 Support for SMSC's LAN91C96 chips. 1099 1100 CONFIG_LAN91C96_USE_32_BIT 1101 Define this to enable 32 bit addressing 1102 1103 CONFIG_SMC91111 1104 Support for SMSC's LAN91C111 chip 1105 1106 CONFIG_SMC91111_BASE 1107 Define this to hold the physical address 1108 of the device (I/O space) 1109 1110 CONFIG_SMC_USE_32_BIT 1111 Define this if data bus is 32 bits 1112 1113 CONFIG_SMC_USE_IOFUNCS 1114 Define this to use i/o functions instead of macros 1115 (some hardware wont work with macros) 1116 1117 CONFIG_DRIVER_TI_EMAC 1118 Support for davinci emac 1119 1120 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1121 Define this if you have more then 3 PHYs. 1122 1123 CONFIG_FTGMAC100 1124 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1125 1126 CONFIG_FTGMAC100_EGIGA 1127 Define this to use GE link update with gigabit PHY. 1128 Define this if FTGMAC100 is connected to gigabit PHY. 1129 If your system has 10/100 PHY only, it might not occur 1130 wrong behavior. Because PHY usually return timeout or 1131 useless data when polling gigabit status and gigabit 1132 control registers. This behavior won't affect the 1133 correctnessof 10/100 link speed update. 1134 1135 CONFIG_SMC911X 1136 Support for SMSC's LAN911x and LAN921x chips 1137 1138 CONFIG_SMC911X_BASE 1139 Define this to hold the physical address 1140 of the device (I/O space) 1141 1142 CONFIG_SMC911X_32_BIT 1143 Define this if data bus is 32 bits 1144 1145 CONFIG_SMC911X_16_BIT 1146 Define this if data bus is 16 bits. If your processor 1147 automatically converts one 32 bit word to two 16 bit 1148 words you may also try CONFIG_SMC911X_32_BIT. 1149 1150 CONFIG_SH_ETHER 1151 Support for Renesas on-chip Ethernet controller 1152 1153 CONFIG_SH_ETHER_USE_PORT 1154 Define the number of ports to be used 1155 1156 CONFIG_SH_ETHER_PHY_ADDR 1157 Define the ETH PHY's address 1158 1159 CONFIG_SH_ETHER_CACHE_WRITEBACK 1160 If this option is set, the driver enables cache flush. 1161 1162- PWM Support: 1163 CONFIG_PWM_IMX 1164 Support for PWM module on the imx6. 1165 1166- TPM Support: 1167 CONFIG_TPM 1168 Support TPM devices. 1169 1170 CONFIG_TPM_TIS_INFINEON 1171 Support for Infineon i2c bus TPM devices. Only one device 1172 per system is supported at this time. 1173 1174 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1175 Define the burst count bytes upper limit 1176 1177 CONFIG_TPM_ST33ZP24 1178 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1179 1180 CONFIG_TPM_ST33ZP24_I2C 1181 Support for STMicroelectronics ST33ZP24 I2C devices. 1182 Requires TPM_ST33ZP24 and I2C. 1183 1184 CONFIG_TPM_ST33ZP24_SPI 1185 Support for STMicroelectronics ST33ZP24 SPI devices. 1186 Requires TPM_ST33ZP24 and SPI. 1187 1188 CONFIG_TPM_ATMEL_TWI 1189 Support for Atmel TWI TPM device. Requires I2C support. 1190 1191 CONFIG_TPM_TIS_LPC 1192 Support for generic parallel port TPM devices. Only one device 1193 per system is supported at this time. 1194 1195 CONFIG_TPM_TIS_BASE_ADDRESS 1196 Base address where the generic TPM device is mapped 1197 to. Contemporary x86 systems usually map it at 1198 0xfed40000. 1199 1200 CONFIG_CMD_TPM 1201 Add tpm monitor functions. 1202 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1203 provides monitor access to authorized functions. 1204 1205 CONFIG_TPM 1206 Define this to enable the TPM support library which provides 1207 functional interfaces to some TPM commands. 1208 Requires support for a TPM device. 1209 1210 CONFIG_TPM_AUTH_SESSIONS 1211 Define this to enable authorized functions in the TPM library. 1212 Requires CONFIG_TPM and CONFIG_SHA1. 1213 1214- USB Support: 1215 At the moment only the UHCI host controller is 1216 supported (PIP405, MIP405); define 1217 CONFIG_USB_UHCI to enable it. 1218 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1219 and define CONFIG_USB_STORAGE to enable the USB 1220 storage devices. 1221 Note: 1222 Supported are USB Keyboards and USB Floppy drives 1223 (TEAC FD-05PUB). 1224 1225 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1226 txfilltuning field in the EHCI controller on reset. 1227 1228 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1229 HW module registers. 1230 1231- USB Device: 1232 Define the below if you wish to use the USB console. 1233 Once firmware is rebuilt from a serial console issue the 1234 command "setenv stdin usbtty; setenv stdout usbtty" and 1235 attach your USB cable. The Unix command "dmesg" should print 1236 it has found a new device. The environment variable usbtty 1237 can be set to gserial or cdc_acm to enable your device to 1238 appear to a USB host as a Linux gserial device or a 1239 Common Device Class Abstract Control Model serial device. 1240 If you select usbtty = gserial you should be able to enumerate 1241 a Linux host by 1242 # modprobe usbserial vendor=0xVendorID product=0xProductID 1243 else if using cdc_acm, simply setting the environment 1244 variable usbtty to be cdc_acm should suffice. The following 1245 might be defined in YourBoardName.h 1246 1247 CONFIG_USB_DEVICE 1248 Define this to build a UDC device 1249 1250 CONFIG_USB_TTY 1251 Define this to have a tty type of device available to 1252 talk to the UDC device 1253 1254 CONFIG_USBD_HS 1255 Define this to enable the high speed support for usb 1256 device and usbtty. If this feature is enabled, a routine 1257 int is_usbd_high_speed(void) 1258 also needs to be defined by the driver to dynamically poll 1259 whether the enumeration has succeded at high speed or full 1260 speed. 1261 1262 CONFIG_SYS_CONSOLE_IS_IN_ENV 1263 Define this if you want stdin, stdout &/or stderr to 1264 be set to usbtty. 1265 1266 If you have a USB-IF assigned VendorID then you may wish to 1267 define your own vendor specific values either in BoardName.h 1268 or directly in usbd_vendor_info.h. If you don't define 1269 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1270 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1271 should pretend to be a Linux device to it's target host. 1272 1273 CONFIG_USBD_MANUFACTURER 1274 Define this string as the name of your company for 1275 - CONFIG_USBD_MANUFACTURER "my company" 1276 1277 CONFIG_USBD_PRODUCT_NAME 1278 Define this string as the name of your product 1279 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1280 1281 CONFIG_USBD_VENDORID 1282 Define this as your assigned Vendor ID from the USB 1283 Implementors Forum. This *must* be a genuine Vendor ID 1284 to avoid polluting the USB namespace. 1285 - CONFIG_USBD_VENDORID 0xFFFF 1286 1287 CONFIG_USBD_PRODUCTID 1288 Define this as the unique Product ID 1289 for your device 1290 - CONFIG_USBD_PRODUCTID 0xFFFF 1291 1292- ULPI Layer Support: 1293 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1294 the generic ULPI layer. The generic layer accesses the ULPI PHY 1295 via the platform viewport, so you need both the genric layer and 1296 the viewport enabled. Currently only Chipidea/ARC based 1297 viewport is supported. 1298 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1299 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1300 If your ULPI phy needs a different reference clock than the 1301 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1302 the appropriate value in Hz. 1303 1304- MMC Support: 1305 The MMC controller on the Intel PXA is supported. To 1306 enable this define CONFIG_MMC. The MMC can be 1307 accessed from the boot prompt by mapping the device 1308 to physical memory similar to flash. Command line is 1309 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1310 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1311 1312 CONFIG_SH_MMCIF 1313 Support for Renesas on-chip MMCIF controller 1314 1315 CONFIG_SH_MMCIF_ADDR 1316 Define the base address of MMCIF registers 1317 1318 CONFIG_SH_MMCIF_CLK 1319 Define the clock frequency for MMCIF 1320 1321 CONFIG_SUPPORT_EMMC_BOOT 1322 Enable some additional features of the eMMC boot partitions. 1323 1324 CONFIG_SUPPORT_EMMC_RPMB 1325 Enable the commands for reading, writing and programming the 1326 key for the Replay Protection Memory Block partition in eMMC. 1327 1328- USB Device Firmware Update (DFU) class support: 1329 CONFIG_USB_FUNCTION_DFU 1330 This enables the USB portion of the DFU USB class 1331 1332 CONFIG_CMD_DFU 1333 This enables the command "dfu" which is used to have 1334 U-Boot create a DFU class device via USB. This command 1335 requires that the "dfu_alt_info" environment variable be 1336 set and define the alt settings to expose to the host. 1337 1338 CONFIG_DFU_MMC 1339 This enables support for exposing (e)MMC devices via DFU. 1340 1341 CONFIG_DFU_NAND 1342 This enables support for exposing NAND devices via DFU. 1343 1344 CONFIG_DFU_RAM 1345 This enables support for exposing RAM via DFU. 1346 Note: DFU spec refer to non-volatile memory usage, but 1347 allow usages beyond the scope of spec - here RAM usage, 1348 one that would help mostly the developer. 1349 1350 CONFIG_SYS_DFU_DATA_BUF_SIZE 1351 Dfu transfer uses a buffer before writing data to the 1352 raw storage device. Make the size (in bytes) of this buffer 1353 configurable. The size of this buffer is also configurable 1354 through the "dfu_bufsiz" environment variable. 1355 1356 CONFIG_SYS_DFU_MAX_FILE_SIZE 1357 When updating files rather than the raw storage device, 1358 we use a static buffer to copy the file into and then write 1359 the buffer once we've been given the whole file. Define 1360 this to the maximum filesize (in bytes) for the buffer. 1361 Default is 4 MiB if undefined. 1362 1363 DFU_DEFAULT_POLL_TIMEOUT 1364 Poll timeout [ms], is the timeout a device can send to the 1365 host. The host must wait for this timeout before sending 1366 a subsequent DFU_GET_STATUS request to the device. 1367 1368 DFU_MANIFEST_POLL_TIMEOUT 1369 Poll timeout [ms], which the device sends to the host when 1370 entering dfuMANIFEST state. Host waits this timeout, before 1371 sending again an USB request to the device. 1372 1373- USB Device Android Fastboot support: 1374 CONFIG_USB_FUNCTION_FASTBOOT 1375 This enables the USB part of the fastboot gadget 1376 1377 CONFIG_CMD_FASTBOOT 1378 This enables the command "fastboot" which enables the Android 1379 fastboot mode for the platform's USB device. Fastboot is a USB 1380 protocol for downloading images, flashing and device control 1381 used on Android devices. 1382 See doc/README.android-fastboot for more information. 1383 1384 CONFIG_ANDROID_BOOT_IMAGE 1385 This enables support for booting images which use the Android 1386 image format header. 1387 1388 CONFIG_FASTBOOT_BUF_ADDR 1389 The fastboot protocol requires a large memory buffer for 1390 downloads. Define this to the starting RAM address to use for 1391 downloaded images. 1392 1393 CONFIG_FASTBOOT_BUF_SIZE 1394 The fastboot protocol requires a large memory buffer for 1395 downloads. This buffer should be as large as possible for a 1396 platform. Define this to the size available RAM for fastboot. 1397 1398 CONFIG_FASTBOOT_FLASH 1399 The fastboot protocol includes a "flash" command for writing 1400 the downloaded image to a non-volatile storage device. Define 1401 this to enable the "fastboot flash" command. 1402 1403 CONFIG_FASTBOOT_FLASH_MMC_DEV 1404 The fastboot "flash" command requires additional information 1405 regarding the non-volatile storage device. Define this to 1406 the eMMC device that fastboot should use to store the image. 1407 1408 CONFIG_FASTBOOT_GPT_NAME 1409 The fastboot "flash" command supports writing the downloaded 1410 image to the Protective MBR and the Primary GUID Partition 1411 Table. (Additionally, this downloaded image is post-processed 1412 to generate and write the Backup GUID Partition Table.) 1413 This occurs when the specified "partition name" on the 1414 "fastboot flash" command line matches this value. 1415 The default is "gpt" if undefined. 1416 1417 CONFIG_FASTBOOT_MBR_NAME 1418 The fastboot "flash" command supports writing the downloaded 1419 image to DOS MBR. 1420 This occurs when the "partition name" specified on the 1421 "fastboot flash" command line matches this value. 1422 If not defined the default value "mbr" is used. 1423 1424- Journaling Flash filesystem support: 1425 CONFIG_JFFS2_NAND 1426 Define these for a default partition on a NAND device 1427 1428 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1429 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1430 Define these for a default partition on a NOR device 1431 1432- Keyboard Support: 1433 See Kconfig help for available keyboard drivers. 1434 1435 CONFIG_KEYBOARD 1436 1437 Define this to enable a custom keyboard support. 1438 This simply calls drv_keyboard_init() which must be 1439 defined in your board-specific files. This option is deprecated 1440 and is only used by novena. For new boards, use driver model 1441 instead. 1442 1443- Video support: 1444 CONFIG_FSL_DIU_FB 1445 Enable the Freescale DIU video driver. Reference boards for 1446 SOCs that have a DIU should define this macro to enable DIU 1447 support, and should also define these other macros: 1448 1449 CONFIG_SYS_DIU_ADDR 1450 CONFIG_VIDEO 1451 CONFIG_CFB_CONSOLE 1452 CONFIG_VIDEO_SW_CURSOR 1453 CONFIG_VGA_AS_SINGLE_DEVICE 1454 CONFIG_VIDEO_LOGO 1455 CONFIG_VIDEO_BMP_LOGO 1456 1457 The DIU driver will look for the 'video-mode' environment 1458 variable, and if defined, enable the DIU as a console during 1459 boot. See the documentation file doc/README.video for a 1460 description of this variable. 1461 1462- LCD Support: CONFIG_LCD 1463 1464 Define this to enable LCD support (for output to LCD 1465 display); also select one of the supported displays 1466 by defining one of these: 1467 1468 CONFIG_ATMEL_LCD: 1469 1470 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1471 1472 CONFIG_NEC_NL6448AC33: 1473 1474 NEC NL6448AC33-18. Active, color, single scan. 1475 1476 CONFIG_NEC_NL6448BC20 1477 1478 NEC NL6448BC20-08. 6.5", 640x480. 1479 Active, color, single scan. 1480 1481 CONFIG_NEC_NL6448BC33_54 1482 1483 NEC NL6448BC33-54. 10.4", 640x480. 1484 Active, color, single scan. 1485 1486 CONFIG_SHARP_16x9 1487 1488 Sharp 320x240. Active, color, single scan. 1489 It isn't 16x9, and I am not sure what it is. 1490 1491 CONFIG_SHARP_LQ64D341 1492 1493 Sharp LQ64D341 display, 640x480. 1494 Active, color, single scan. 1495 1496 CONFIG_HLD1045 1497 1498 HLD1045 display, 640x480. 1499 Active, color, single scan. 1500 1501 CONFIG_OPTREX_BW 1502 1503 Optrex CBL50840-2 NF-FW 99 22 M5 1504 or 1505 Hitachi LMG6912RPFC-00T 1506 or 1507 Hitachi SP14Q002 1508 1509 320x240. Black & white. 1510 1511 CONFIG_LCD_ALIGNMENT 1512 1513 Normally the LCD is page-aligned (typically 4KB). If this is 1514 defined then the LCD will be aligned to this value instead. 1515 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1516 here, since it is cheaper to change data cache settings on 1517 a per-section basis. 1518 1519 1520 CONFIG_LCD_ROTATION 1521 1522 Sometimes, for example if the display is mounted in portrait 1523 mode or even if it's mounted landscape but rotated by 180degree, 1524 we need to rotate our content of the display relative to the 1525 framebuffer, so that user can read the messages which are 1526 printed out. 1527 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1528 initialized with a given rotation from "vl_rot" out of 1529 "vidinfo_t" which is provided by the board specific code. 1530 The value for vl_rot is coded as following (matching to 1531 fbcon=rotate:<n> linux-kernel commandline): 1532 0 = no rotation respectively 0 degree 1533 1 = 90 degree rotation 1534 2 = 180 degree rotation 1535 3 = 270 degree rotation 1536 1537 If CONFIG_LCD_ROTATION is not defined, the console will be 1538 initialized with 0degree rotation. 1539 1540 CONFIG_LCD_BMP_RLE8 1541 1542 Support drawing of RLE8-compressed bitmaps on the LCD. 1543 1544 CONFIG_I2C_EDID 1545 1546 Enables an 'i2c edid' command which can read EDID 1547 information over I2C from an attached LCD display. 1548 1549- Splash Screen Support: CONFIG_SPLASH_SCREEN 1550 1551 If this option is set, the environment is checked for 1552 a variable "splashimage". If found, the usual display 1553 of logo, copyright and system information on the LCD 1554 is suppressed and the BMP image at the address 1555 specified in "splashimage" is loaded instead. The 1556 console is redirected to the "nulldev", too. This 1557 allows for a "silent" boot where a splash screen is 1558 loaded very quickly after power-on. 1559 1560 CONFIG_SPLASHIMAGE_GUARD 1561 1562 If this option is set, then U-Boot will prevent the environment 1563 variable "splashimage" from being set to a problematic address 1564 (see doc/README.displaying-bmps). 1565 This option is useful for targets where, due to alignment 1566 restrictions, an improperly aligned BMP image will cause a data 1567 abort. If you think you will not have problems with unaligned 1568 accesses (for example because your toolchain prevents them) 1569 there is no need to set this option. 1570 1571 CONFIG_SPLASH_SCREEN_ALIGN 1572 1573 If this option is set the splash image can be freely positioned 1574 on the screen. Environment variable "splashpos" specifies the 1575 position as "x,y". If a positive number is given it is used as 1576 number of pixel from left/top. If a negative number is given it 1577 is used as number of pixel from right/bottom. You can also 1578 specify 'm' for centering the image. 1579 1580 Example: 1581 setenv splashpos m,m 1582 => image at center of screen 1583 1584 setenv splashpos 30,20 1585 => image at x = 30 and y = 20 1586 1587 setenv splashpos -10,m 1588 => vertically centered image 1589 at x = dspWidth - bmpWidth - 9 1590 1591- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1592 1593 If this option is set, additionally to standard BMP 1594 images, gzipped BMP images can be displayed via the 1595 splashscreen support or the bmp command. 1596 1597- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1598 1599 If this option is set, 8-bit RLE compressed BMP images 1600 can be displayed via the splashscreen support or the 1601 bmp command. 1602 1603- Compression support: 1604 CONFIG_GZIP 1605 1606 Enabled by default to support gzip compressed images. 1607 1608 CONFIG_BZIP2 1609 1610 If this option is set, support for bzip2 compressed 1611 images is included. If not, only uncompressed and gzip 1612 compressed images are supported. 1613 1614 NOTE: the bzip2 algorithm requires a lot of RAM, so 1615 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1616 be at least 4MB. 1617 1618- MII/PHY support: 1619 CONFIG_PHY_ADDR 1620 1621 The address of PHY on MII bus. 1622 1623 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1624 1625 The clock frequency of the MII bus 1626 1627 CONFIG_PHY_RESET_DELAY 1628 1629 Some PHY like Intel LXT971A need extra delay after 1630 reset before any MII register access is possible. 1631 For such PHY, set this option to the usec delay 1632 required. (minimum 300usec for LXT971A) 1633 1634 CONFIG_PHY_CMD_DELAY (ppc4xx) 1635 1636 Some PHY like Intel LXT971A need extra delay after 1637 command issued before MII status register can be read 1638 1639- IP address: 1640 CONFIG_IPADDR 1641 1642 Define a default value for the IP address to use for 1643 the default Ethernet interface, in case this is not 1644 determined through e.g. bootp. 1645 (Environment variable "ipaddr") 1646 1647- Server IP address: 1648 CONFIG_SERVERIP 1649 1650 Defines a default value for the IP address of a TFTP 1651 server to contact when using the "tftboot" command. 1652 (Environment variable "serverip") 1653 1654 CONFIG_KEEP_SERVERADDR 1655 1656 Keeps the server's MAC address, in the env 'serveraddr' 1657 for passing to bootargs (like Linux's netconsole option) 1658 1659- Gateway IP address: 1660 CONFIG_GATEWAYIP 1661 1662 Defines a default value for the IP address of the 1663 default router where packets to other networks are 1664 sent to. 1665 (Environment variable "gatewayip") 1666 1667- Subnet mask: 1668 CONFIG_NETMASK 1669 1670 Defines a default value for the subnet mask (or 1671 routing prefix) which is used to determine if an IP 1672 address belongs to the local subnet or needs to be 1673 forwarded through a router. 1674 (Environment variable "netmask") 1675 1676- Multicast TFTP Mode: 1677 CONFIG_MCAST_TFTP 1678 1679 Defines whether you want to support multicast TFTP as per 1680 rfc-2090; for example to work with atftp. Lets lots of targets 1681 tftp down the same boot image concurrently. Note: the Ethernet 1682 driver in use must provide a function: mcast() to join/leave a 1683 multicast group. 1684 1685- BOOTP Recovery Mode: 1686 CONFIG_BOOTP_RANDOM_DELAY 1687 1688 If you have many targets in a network that try to 1689 boot using BOOTP, you may want to avoid that all 1690 systems send out BOOTP requests at precisely the same 1691 moment (which would happen for instance at recovery 1692 from a power failure, when all systems will try to 1693 boot, thus flooding the BOOTP server. Defining 1694 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1695 inserted before sending out BOOTP requests. The 1696 following delays are inserted then: 1697 1698 1st BOOTP request: delay 0 ... 1 sec 1699 2nd BOOTP request: delay 0 ... 2 sec 1700 3rd BOOTP request: delay 0 ... 4 sec 1701 4th and following 1702 BOOTP requests: delay 0 ... 8 sec 1703 1704 CONFIG_BOOTP_ID_CACHE_SIZE 1705 1706 BOOTP packets are uniquely identified using a 32-bit ID. The 1707 server will copy the ID from client requests to responses and 1708 U-Boot will use this to determine if it is the destination of 1709 an incoming response. Some servers will check that addresses 1710 aren't in use before handing them out (usually using an ARP 1711 ping) and therefore take up to a few hundred milliseconds to 1712 respond. Network congestion may also influence the time it 1713 takes for a response to make it back to the client. If that 1714 time is too long, U-Boot will retransmit requests. In order 1715 to allow earlier responses to still be accepted after these 1716 retransmissions, U-Boot's BOOTP client keeps a small cache of 1717 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1718 cache. The default is to keep IDs for up to four outstanding 1719 requests. Increasing this will allow U-Boot to accept offers 1720 from a BOOTP client in networks with unusually high latency. 1721 1722- DHCP Advanced Options: 1723 You can fine tune the DHCP functionality by defining 1724 CONFIG_BOOTP_* symbols: 1725 1726 CONFIG_BOOTP_SUBNETMASK 1727 CONFIG_BOOTP_GATEWAY 1728 CONFIG_BOOTP_HOSTNAME 1729 CONFIG_BOOTP_NISDOMAIN 1730 CONFIG_BOOTP_BOOTPATH 1731 CONFIG_BOOTP_BOOTFILESIZE 1732 CONFIG_BOOTP_DNS 1733 CONFIG_BOOTP_DNS2 1734 CONFIG_BOOTP_SEND_HOSTNAME 1735 CONFIG_BOOTP_NTPSERVER 1736 CONFIG_BOOTP_TIMEOFFSET 1737 CONFIG_BOOTP_VENDOREX 1738 CONFIG_BOOTP_MAY_FAIL 1739 1740 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1741 environment variable, not the BOOTP server. 1742 1743 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1744 after the configured retry count, the call will fail 1745 instead of starting over. This can be used to fail over 1746 to Link-local IP address configuration if the DHCP server 1747 is not available. 1748 1749 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1750 serverip from a DHCP server, it is possible that more 1751 than one DNS serverip is offered to the client. 1752 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1753 serverip will be stored in the additional environment 1754 variable "dnsip2". The first DNS serverip is always 1755 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1756 is defined. 1757 1758 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1759 to do a dynamic update of a DNS server. To do this, they 1760 need the hostname of the DHCP requester. 1761 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1762 of the "hostname" environment variable is passed as 1763 option 12 to the DHCP server. 1764 1765 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1766 1767 A 32bit value in microseconds for a delay between 1768 receiving a "DHCP Offer" and sending the "DHCP Request". 1769 This fixes a problem with certain DHCP servers that don't 1770 respond 100% of the time to a "DHCP request". E.g. On an 1771 AT91RM9200 processor running at 180MHz, this delay needed 1772 to be *at least* 15,000 usec before a Windows Server 2003 1773 DHCP server would reply 100% of the time. I recommend at 1774 least 50,000 usec to be safe. The alternative is to hope 1775 that one of the retries will be successful but note that 1776 the DHCP timeout and retry process takes a longer than 1777 this delay. 1778 1779 - Link-local IP address negotiation: 1780 Negotiate with other link-local clients on the local network 1781 for an address that doesn't require explicit configuration. 1782 This is especially useful if a DHCP server cannot be guaranteed 1783 to exist in all environments that the device must operate. 1784 1785 See doc/README.link-local for more information. 1786 1787 - CDP Options: 1788 CONFIG_CDP_DEVICE_ID 1789 1790 The device id used in CDP trigger frames. 1791 1792 CONFIG_CDP_DEVICE_ID_PREFIX 1793 1794 A two character string which is prefixed to the MAC address 1795 of the device. 1796 1797 CONFIG_CDP_PORT_ID 1798 1799 A printf format string which contains the ascii name of 1800 the port. Normally is set to "eth%d" which sets 1801 eth0 for the first Ethernet, eth1 for the second etc. 1802 1803 CONFIG_CDP_CAPABILITIES 1804 1805 A 32bit integer which indicates the device capabilities; 1806 0x00000010 for a normal host which does not forwards. 1807 1808 CONFIG_CDP_VERSION 1809 1810 An ascii string containing the version of the software. 1811 1812 CONFIG_CDP_PLATFORM 1813 1814 An ascii string containing the name of the platform. 1815 1816 CONFIG_CDP_TRIGGER 1817 1818 A 32bit integer sent on the trigger. 1819 1820 CONFIG_CDP_POWER_CONSUMPTION 1821 1822 A 16bit integer containing the power consumption of the 1823 device in .1 of milliwatts. 1824 1825 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1826 1827 A byte containing the id of the VLAN. 1828 1829- Status LED: CONFIG_LED_STATUS 1830 1831 Several configurations allow to display the current 1832 status using a LED. For instance, the LED will blink 1833 fast while running U-Boot code, stop blinking as 1834 soon as a reply to a BOOTP request was received, and 1835 start blinking slow once the Linux kernel is running 1836 (supported by a status LED driver in the Linux 1837 kernel). Defining CONFIG_LED_STATUS enables this 1838 feature in U-Boot. 1839 1840 Additional options: 1841 1842 CONFIG_LED_STATUS_GPIO 1843 The status LED can be connected to a GPIO pin. 1844 In such cases, the gpio_led driver can be used as a 1845 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1846 to include the gpio_led driver in the U-Boot binary. 1847 1848 CONFIG_GPIO_LED_INVERTED_TABLE 1849 Some GPIO connected LEDs may have inverted polarity in which 1850 case the GPIO high value corresponds to LED off state and 1851 GPIO low value corresponds to LED on state. 1852 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1853 with a list of GPIO LEDs that have inverted polarity. 1854 1855- I2C Support: CONFIG_SYS_I2C 1856 1857 This enable the NEW i2c subsystem, and will allow you to use 1858 i2c commands at the u-boot command line (as long as you set 1859 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1860 based realtime clock chips or other i2c devices. See 1861 common/cmd_i2c.c for a description of the command line 1862 interface. 1863 1864 ported i2c driver to the new framework: 1865 - drivers/i2c/soft_i2c.c: 1866 - activate first bus with CONFIG_SYS_I2C_SOFT define 1867 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1868 for defining speed and slave address 1869 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1870 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1871 for defining speed and slave address 1872 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1873 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1874 for defining speed and slave address 1875 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1876 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1877 for defining speed and slave address 1878 1879 - drivers/i2c/fsl_i2c.c: 1880 - activate i2c driver with CONFIG_SYS_I2C_FSL 1881 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1882 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1883 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1884 bus. 1885 - If your board supports a second fsl i2c bus, define 1886 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1887 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1888 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1889 second bus. 1890 1891 - drivers/i2c/tegra_i2c.c: 1892 - activate this driver with CONFIG_SYS_I2C_TEGRA 1893 - This driver adds 4 i2c buses with a fix speed from 1894 100000 and the slave addr 0! 1895 1896 - drivers/i2c/ppc4xx_i2c.c 1897 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1898 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1899 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1900 1901 - drivers/i2c/i2c_mxc.c 1902 - activate this driver with CONFIG_SYS_I2C_MXC 1903 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1904 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1905 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1906 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1907 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1908 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1909 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1910 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1911 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1912 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1913 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1914 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1915 If those defines are not set, default value is 100000 1916 for speed, and 0 for slave. 1917 1918 - drivers/i2c/rcar_i2c.c: 1919 - activate this driver with CONFIG_SYS_I2C_RCAR 1920 - This driver adds 4 i2c buses 1921 1922 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1923 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1924 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1925 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1926 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1927 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1928 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1929 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1930 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1931 1932 - drivers/i2c/sh_i2c.c: 1933 - activate this driver with CONFIG_SYS_I2C_SH 1934 - This driver adds from 2 to 5 i2c buses 1935 1936 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1937 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1938 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1939 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1940 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1941 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1942 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1943 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1944 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1945 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1946 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1947 1948 - drivers/i2c/omap24xx_i2c.c 1949 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1950 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1951 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1952 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1953 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1954 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1955 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1956 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1957 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1958 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1959 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1960 1961 - drivers/i2c/zynq_i2c.c 1962 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1963 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1964 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1965 1966 - drivers/i2c/s3c24x0_i2c.c: 1967 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1968 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1969 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1970 with a fix speed from 100000 and the slave addr 0! 1971 1972 - drivers/i2c/ihs_i2c.c 1973 - activate this driver with CONFIG_SYS_I2C_IHS 1974 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1975 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1976 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1977 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1978 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1979 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1980 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1981 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1982 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1983 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1984 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1985 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1986 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1987 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1988 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1989 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1990 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1991 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1992 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1993 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1994 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1995 1996 additional defines: 1997 1998 CONFIG_SYS_NUM_I2C_BUSES 1999 Hold the number of i2c buses you want to use. 2000 2001 CONFIG_SYS_I2C_DIRECT_BUS 2002 define this, if you don't use i2c muxes on your hardware. 2003 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2004 omit this define. 2005 2006 CONFIG_SYS_I2C_MAX_HOPS 2007 define how many muxes are maximal consecutively connected 2008 on one i2c bus. If you not use i2c muxes, omit this 2009 define. 2010 2011 CONFIG_SYS_I2C_BUSES 2012 hold a list of buses you want to use, only used if 2013 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2014 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2015 CONFIG_SYS_NUM_I2C_BUSES = 9: 2016 2017 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2018 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2019 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2020 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2021 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2022 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2023 {1, {I2C_NULL_HOP}}, \ 2024 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2025 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2026 } 2027 2028 which defines 2029 bus 0 on adapter 0 without a mux 2030 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2031 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2032 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2033 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2034 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2035 bus 6 on adapter 1 without a mux 2036 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2037 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2038 2039 If you do not have i2c muxes on your board, omit this define. 2040 2041- Legacy I2C Support: 2042 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2043 then the following macros need to be defined (examples are 2044 from include/configs/lwmon.h): 2045 2046 I2C_INIT 2047 2048 (Optional). Any commands necessary to enable the I2C 2049 controller or configure ports. 2050 2051 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2052 2053 I2C_ACTIVE 2054 2055 The code necessary to make the I2C data line active 2056 (driven). If the data line is open collector, this 2057 define can be null. 2058 2059 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2060 2061 I2C_TRISTATE 2062 2063 The code necessary to make the I2C data line tri-stated 2064 (inactive). If the data line is open collector, this 2065 define can be null. 2066 2067 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2068 2069 I2C_READ 2070 2071 Code that returns true if the I2C data line is high, 2072 false if it is low. 2073 2074 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2075 2076 I2C_SDA(bit) 2077 2078 If <bit> is true, sets the I2C data line high. If it 2079 is false, it clears it (low). 2080 2081 eg: #define I2C_SDA(bit) \ 2082 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2083 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2084 2085 I2C_SCL(bit) 2086 2087 If <bit> is true, sets the I2C clock line high. If it 2088 is false, it clears it (low). 2089 2090 eg: #define I2C_SCL(bit) \ 2091 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2092 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2093 2094 I2C_DELAY 2095 2096 This delay is invoked four times per clock cycle so this 2097 controls the rate of data transfer. The data rate thus 2098 is 1 / (I2C_DELAY * 4). Often defined to be something 2099 like: 2100 2101 #define I2C_DELAY udelay(2) 2102 2103 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2104 2105 If your arch supports the generic GPIO framework (asm/gpio.h), 2106 then you may alternatively define the two GPIOs that are to be 2107 used as SCL / SDA. Any of the previous I2C_xxx macros will 2108 have GPIO-based defaults assigned to them as appropriate. 2109 2110 You should define these to the GPIO value as given directly to 2111 the generic GPIO functions. 2112 2113 CONFIG_SYS_I2C_INIT_BOARD 2114 2115 When a board is reset during an i2c bus transfer 2116 chips might think that the current transfer is still 2117 in progress. On some boards it is possible to access 2118 the i2c SCLK line directly, either by using the 2119 processor pin as a GPIO or by having a second pin 2120 connected to the bus. If this option is defined a 2121 custom i2c_init_board() routine in boards/xxx/board.c 2122 is run early in the boot sequence. 2123 2124 CONFIG_I2C_MULTI_BUS 2125 2126 This option allows the use of multiple I2C buses, each of which 2127 must have a controller. At any point in time, only one bus is 2128 active. To switch to a different bus, use the 'i2c dev' command. 2129 Note that bus numbering is zero-based. 2130 2131 CONFIG_SYS_I2C_NOPROBES 2132 2133 This option specifies a list of I2C devices that will be skipped 2134 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2135 is set, specify a list of bus-device pairs. Otherwise, specify 2136 a 1D array of device addresses 2137 2138 e.g. 2139 #undef CONFIG_I2C_MULTI_BUS 2140 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2141 2142 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2143 2144 #define CONFIG_I2C_MULTI_BUS 2145 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2146 2147 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2148 2149 CONFIG_SYS_SPD_BUS_NUM 2150 2151 If defined, then this indicates the I2C bus number for DDR SPD. 2152 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2153 2154 CONFIG_SYS_RTC_BUS_NUM 2155 2156 If defined, then this indicates the I2C bus number for the RTC. 2157 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2158 2159 CONFIG_SOFT_I2C_READ_REPEATED_START 2160 2161 defining this will force the i2c_read() function in 2162 the soft_i2c driver to perform an I2C repeated start 2163 between writing the address pointer and reading the 2164 data. If this define is omitted the default behaviour 2165 of doing a stop-start sequence will be used. Most I2C 2166 devices can use either method, but some require one or 2167 the other. 2168 2169- SPI Support: CONFIG_SPI 2170 2171 Enables SPI driver (so far only tested with 2172 SPI EEPROM, also an instance works with Crystal A/D and 2173 D/As on the SACSng board) 2174 2175 CONFIG_SH_SPI 2176 2177 Enables the driver for SPI controller on SuperH. Currently 2178 only SH7757 is supported. 2179 2180 CONFIG_SOFT_SPI 2181 2182 Enables a software (bit-bang) SPI driver rather than 2183 using hardware support. This is a general purpose 2184 driver that only requires three general I/O port pins 2185 (two outputs, one input) to function. If this is 2186 defined, the board configuration must define several 2187 SPI configuration items (port pins to use, etc). For 2188 an example, see include/configs/sacsng.h. 2189 2190 CONFIG_HARD_SPI 2191 2192 Enables a hardware SPI driver for general-purpose reads 2193 and writes. As with CONFIG_SOFT_SPI, the board configuration 2194 must define a list of chip-select function pointers. 2195 Currently supported on some MPC8xxx processors. For an 2196 example, see include/configs/mpc8349emds.h. 2197 2198 CONFIG_MXC_SPI 2199 2200 Enables the driver for the SPI controllers on i.MX and MXC 2201 SoCs. Currently i.MX31/35/51 are supported. 2202 2203 CONFIG_SYS_SPI_MXC_WAIT 2204 Timeout for waiting until spi transfer completed. 2205 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2206 2207- FPGA Support: CONFIG_FPGA 2208 2209 Enables FPGA subsystem. 2210 2211 CONFIG_FPGA_<vendor> 2212 2213 Enables support for specific chip vendors. 2214 (ALTERA, XILINX) 2215 2216 CONFIG_FPGA_<family> 2217 2218 Enables support for FPGA family. 2219 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2220 2221 CONFIG_FPGA_COUNT 2222 2223 Specify the number of FPGA devices to support. 2224 2225 CONFIG_SYS_FPGA_PROG_FEEDBACK 2226 2227 Enable printing of hash marks during FPGA configuration. 2228 2229 CONFIG_SYS_FPGA_CHECK_BUSY 2230 2231 Enable checks on FPGA configuration interface busy 2232 status by the configuration function. This option 2233 will require a board or device specific function to 2234 be written. 2235 2236 CONFIG_FPGA_DELAY 2237 2238 If defined, a function that provides delays in the FPGA 2239 configuration driver. 2240 2241 CONFIG_SYS_FPGA_CHECK_CTRLC 2242 Allow Control-C to interrupt FPGA configuration 2243 2244 CONFIG_SYS_FPGA_CHECK_ERROR 2245 2246 Check for configuration errors during FPGA bitfile 2247 loading. For example, abort during Virtex II 2248 configuration if the INIT_B line goes low (which 2249 indicated a CRC error). 2250 2251 CONFIG_SYS_FPGA_WAIT_INIT 2252 2253 Maximum time to wait for the INIT_B line to de-assert 2254 after PROB_B has been de-asserted during a Virtex II 2255 FPGA configuration sequence. The default time is 500 2256 ms. 2257 2258 CONFIG_SYS_FPGA_WAIT_BUSY 2259 2260 Maximum time to wait for BUSY to de-assert during 2261 Virtex II FPGA configuration. The default is 5 ms. 2262 2263 CONFIG_SYS_FPGA_WAIT_CONFIG 2264 2265 Time to wait after FPGA configuration. The default is 2266 200 ms. 2267 2268- Configuration Management: 2269 CONFIG_BUILD_TARGET 2270 2271 Some SoCs need special image types (e.g. U-Boot binary 2272 with a special header) as build targets. By defining 2273 CONFIG_BUILD_TARGET in the SoC / board header, this 2274 special image will be automatically built upon calling 2275 make / buildman. 2276 2277 CONFIG_IDENT_STRING 2278 2279 If defined, this string will be added to the U-Boot 2280 version information (U_BOOT_VERSION) 2281 2282- Vendor Parameter Protection: 2283 2284 U-Boot considers the values of the environment 2285 variables "serial#" (Board Serial Number) and 2286 "ethaddr" (Ethernet Address) to be parameters that 2287 are set once by the board vendor / manufacturer, and 2288 protects these variables from casual modification by 2289 the user. Once set, these variables are read-only, 2290 and write or delete attempts are rejected. You can 2291 change this behaviour: 2292 2293 If CONFIG_ENV_OVERWRITE is #defined in your config 2294 file, the write protection for vendor parameters is 2295 completely disabled. Anybody can change or delete 2296 these parameters. 2297 2298 Alternatively, if you define _both_ an ethaddr in the 2299 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2300 Ethernet address is installed in the environment, 2301 which can be changed exactly ONCE by the user. [The 2302 serial# is unaffected by this, i. e. it remains 2303 read-only.] 2304 2305 The same can be accomplished in a more flexible way 2306 for any variable by configuring the type of access 2307 to allow for those variables in the ".flags" variable 2308 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2309 2310- Protected RAM: 2311 CONFIG_PRAM 2312 2313 Define this variable to enable the reservation of 2314 "protected RAM", i. e. RAM which is not overwritten 2315 by U-Boot. Define CONFIG_PRAM to hold the number of 2316 kB you want to reserve for pRAM. You can overwrite 2317 this default value by defining an environment 2318 variable "pram" to the number of kB you want to 2319 reserve. Note that the board info structure will 2320 still show the full amount of RAM. If pRAM is 2321 reserved, a new environment variable "mem" will 2322 automatically be defined to hold the amount of 2323 remaining RAM in a form that can be passed as boot 2324 argument to Linux, for instance like that: 2325 2326 setenv bootargs ... mem=\${mem} 2327 saveenv 2328 2329 This way you can tell Linux not to use this memory, 2330 either, which results in a memory region that will 2331 not be affected by reboots. 2332 2333 *WARNING* If your board configuration uses automatic 2334 detection of the RAM size, you must make sure that 2335 this memory test is non-destructive. So far, the 2336 following board configurations are known to be 2337 "pRAM-clean": 2338 2339 IVMS8, IVML24, SPD8xx, 2340 HERMES, IP860, RPXlite, LWMON, 2341 FLAGADM 2342 2343- Access to physical memory region (> 4GB) 2344 Some basic support is provided for operations on memory not 2345 normally accessible to U-Boot - e.g. some architectures 2346 support access to more than 4GB of memory on 32-bit 2347 machines using physical address extension or similar. 2348 Define CONFIG_PHYSMEM to access this basic support, which 2349 currently only supports clearing the memory. 2350 2351- Error Recovery: 2352 CONFIG_PANIC_HANG 2353 2354 Define this variable to stop the system in case of a 2355 fatal error, so that you have to reset it manually. 2356 This is probably NOT a good idea for an embedded 2357 system where you want the system to reboot 2358 automatically as fast as possible, but it may be 2359 useful during development since you can try to debug 2360 the conditions that lead to the situation. 2361 2362 CONFIG_NET_RETRY_COUNT 2363 2364 This variable defines the number of retries for 2365 network operations like ARP, RARP, TFTP, or BOOTP 2366 before giving up the operation. If not defined, a 2367 default value of 5 is used. 2368 2369 CONFIG_ARP_TIMEOUT 2370 2371 Timeout waiting for an ARP reply in milliseconds. 2372 2373 CONFIG_NFS_TIMEOUT 2374 2375 Timeout in milliseconds used in NFS protocol. 2376 If you encounter "ERROR: Cannot umount" in nfs command, 2377 try longer timeout such as 2378 #define CONFIG_NFS_TIMEOUT 10000UL 2379 2380- Command Interpreter: 2381 CONFIG_AUTO_COMPLETE 2382 2383 Enable auto completion of commands using TAB. 2384 2385 CONFIG_SYS_PROMPT_HUSH_PS2 2386 2387 This defines the secondary prompt string, which is 2388 printed when the command interpreter needs more input 2389 to complete a command. Usually "> ". 2390 2391 Note: 2392 2393 In the current implementation, the local variables 2394 space and global environment variables space are 2395 separated. Local variables are those you define by 2396 simply typing `name=value'. To access a local 2397 variable later on, you have write `$name' or 2398 `${name}'; to execute the contents of a variable 2399 directly type `$name' at the command prompt. 2400 2401 Global environment variables are those you use 2402 setenv/printenv to work with. To run a command stored 2403 in such a variable, you need to use the run command, 2404 and you must not use the '$' sign to access them. 2405 2406 To store commands and special characters in a 2407 variable, please use double quotation marks 2408 surrounding the whole text of the variable, instead 2409 of the backslashes before semicolons and special 2410 symbols. 2411 2412- Command Line Editing and History: 2413 CONFIG_CMDLINE_EDITING 2414 2415 Enable editing and History functions for interactive 2416 command line input operations 2417 2418- Command Line PS1/PS2 support: 2419 CONFIG_CMDLINE_PS_SUPPORT 2420 2421 Enable support for changing the command prompt string 2422 at run-time. Only static string is supported so far. 2423 The string is obtained from environment variables PS1 2424 and PS2. 2425 2426- Default Environment: 2427 CONFIG_EXTRA_ENV_SETTINGS 2428 2429 Define this to contain any number of null terminated 2430 strings (variable = value pairs) that will be part of 2431 the default environment compiled into the boot image. 2432 2433 For example, place something like this in your 2434 board's config file: 2435 2436 #define CONFIG_EXTRA_ENV_SETTINGS \ 2437 "myvar1=value1\0" \ 2438 "myvar2=value2\0" 2439 2440 Warning: This method is based on knowledge about the 2441 internal format how the environment is stored by the 2442 U-Boot code. This is NOT an official, exported 2443 interface! Although it is unlikely that this format 2444 will change soon, there is no guarantee either. 2445 You better know what you are doing here. 2446 2447 Note: overly (ab)use of the default environment is 2448 discouraged. Make sure to check other ways to preset 2449 the environment like the "source" command or the 2450 boot command first. 2451 2452 CONFIG_ENV_VARS_UBOOT_CONFIG 2453 2454 Define this in order to add variables describing the 2455 U-Boot build configuration to the default environment. 2456 These will be named arch, cpu, board, vendor, and soc. 2457 2458 Enabling this option will cause the following to be defined: 2459 2460 - CONFIG_SYS_ARCH 2461 - CONFIG_SYS_CPU 2462 - CONFIG_SYS_BOARD 2463 - CONFIG_SYS_VENDOR 2464 - CONFIG_SYS_SOC 2465 2466 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2467 2468 Define this in order to add variables describing certain 2469 run-time determined information about the hardware to the 2470 environment. These will be named board_name, board_rev. 2471 2472 CONFIG_DELAY_ENVIRONMENT 2473 2474 Normally the environment is loaded when the board is 2475 initialised so that it is available to U-Boot. This inhibits 2476 that so that the environment is not available until 2477 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2478 this is instead controlled by the value of 2479 /config/load-environment. 2480 2481- DataFlash Support: 2482 CONFIG_HAS_DATAFLASH 2483 2484 Defining this option enables DataFlash features and 2485 allows to read/write in Dataflash via the standard 2486 commands cp, md... 2487 2488- Serial Flash support 2489 CONFIG_CMD_SF 2490 2491 Defining this option enables SPI flash commands 2492 'sf probe/read/write/erase/update'. 2493 2494 Usage requires an initial 'probe' to define the serial 2495 flash parameters, followed by read/write/erase/update 2496 commands. 2497 2498 The following defaults may be provided by the platform 2499 to handle the common case when only a single serial 2500 flash is present on the system. 2501 2502 CONFIG_SF_DEFAULT_BUS Bus identifier 2503 CONFIG_SF_DEFAULT_CS Chip-select 2504 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2505 CONFIG_SF_DEFAULT_SPEED in Hz 2506 2507 CONFIG_CMD_SF_TEST 2508 2509 Define this option to include a destructive SPI flash 2510 test ('sf test'). 2511 2512- SystemACE Support: 2513 CONFIG_SYSTEMACE 2514 2515 Adding this option adds support for Xilinx SystemACE 2516 chips attached via some sort of local bus. The address 2517 of the chip must also be defined in the 2518 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2519 2520 #define CONFIG_SYSTEMACE 2521 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2522 2523 When SystemACE support is added, the "ace" device type 2524 becomes available to the fat commands, i.e. fatls. 2525 2526- TFTP Fixed UDP Port: 2527 CONFIG_TFTP_PORT 2528 2529 If this is defined, the environment variable tftpsrcp 2530 is used to supply the TFTP UDP source port value. 2531 If tftpsrcp isn't defined, the normal pseudo-random port 2532 number generator is used. 2533 2534 Also, the environment variable tftpdstp is used to supply 2535 the TFTP UDP destination port value. If tftpdstp isn't 2536 defined, the normal port 69 is used. 2537 2538 The purpose for tftpsrcp is to allow a TFTP server to 2539 blindly start the TFTP transfer using the pre-configured 2540 target IP address and UDP port. This has the effect of 2541 "punching through" the (Windows XP) firewall, allowing 2542 the remainder of the TFTP transfer to proceed normally. 2543 A better solution is to properly configure the firewall, 2544 but sometimes that is not allowed. 2545 2546- bootcount support: 2547 CONFIG_BOOTCOUNT_LIMIT 2548 2549 This enables the bootcounter support, see: 2550 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2551 2552 CONFIG_AT91SAM9XE 2553 enable special bootcounter support on at91sam9xe based boards. 2554 CONFIG_SOC_DA8XX 2555 enable special bootcounter support on da850 based boards. 2556 CONFIG_BOOTCOUNT_RAM 2557 enable support for the bootcounter in RAM 2558 CONFIG_BOOTCOUNT_I2C 2559 enable support for the bootcounter on an i2c (like RTC) device. 2560 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2561 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2562 the bootcounter. 2563 CONFIG_BOOTCOUNT_ALEN = address len 2564 2565- Show boot progress: 2566 CONFIG_SHOW_BOOT_PROGRESS 2567 2568 Defining this option allows to add some board- 2569 specific code (calling a user-provided function 2570 "show_boot_progress(int)") that enables you to show 2571 the system's boot progress on some display (for 2572 example, some LED's) on your board. At the moment, 2573 the following checkpoints are implemented: 2574 2575 2576Legacy uImage format: 2577 2578 Arg Where When 2579 1 common/cmd_bootm.c before attempting to boot an image 2580 -1 common/cmd_bootm.c Image header has bad magic number 2581 2 common/cmd_bootm.c Image header has correct magic number 2582 -2 common/cmd_bootm.c Image header has bad checksum 2583 3 common/cmd_bootm.c Image header has correct checksum 2584 -3 common/cmd_bootm.c Image data has bad checksum 2585 4 common/cmd_bootm.c Image data has correct checksum 2586 -4 common/cmd_bootm.c Image is for unsupported architecture 2587 5 common/cmd_bootm.c Architecture check OK 2588 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2589 6 common/cmd_bootm.c Image Type check OK 2590 -6 common/cmd_bootm.c gunzip uncompression error 2591 -7 common/cmd_bootm.c Unimplemented compression type 2592 7 common/cmd_bootm.c Uncompression OK 2593 8 common/cmd_bootm.c No uncompress/copy overwrite error 2594 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2595 2596 9 common/image.c Start initial ramdisk verification 2597 -10 common/image.c Ramdisk header has bad magic number 2598 -11 common/image.c Ramdisk header has bad checksum 2599 10 common/image.c Ramdisk header is OK 2600 -12 common/image.c Ramdisk data has bad checksum 2601 11 common/image.c Ramdisk data has correct checksum 2602 12 common/image.c Ramdisk verification complete, start loading 2603 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2604 13 common/image.c Start multifile image verification 2605 14 common/image.c No initial ramdisk, no multifile, continue. 2606 2607 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2608 2609 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2610 -31 post/post.c POST test failed, detected by post_output_backlog() 2611 -32 post/post.c POST test failed, detected by post_run_single() 2612 2613 34 common/cmd_doc.c before loading a Image from a DOC device 2614 -35 common/cmd_doc.c Bad usage of "doc" command 2615 35 common/cmd_doc.c correct usage of "doc" command 2616 -36 common/cmd_doc.c No boot device 2617 36 common/cmd_doc.c correct boot device 2618 -37 common/cmd_doc.c Unknown Chip ID on boot device 2619 37 common/cmd_doc.c correct chip ID found, device available 2620 -38 common/cmd_doc.c Read Error on boot device 2621 38 common/cmd_doc.c reading Image header from DOC device OK 2622 -39 common/cmd_doc.c Image header has bad magic number 2623 39 common/cmd_doc.c Image header has correct magic number 2624 -40 common/cmd_doc.c Error reading Image from DOC device 2625 40 common/cmd_doc.c Image header has correct magic number 2626 41 common/cmd_ide.c before loading a Image from a IDE device 2627 -42 common/cmd_ide.c Bad usage of "ide" command 2628 42 common/cmd_ide.c correct usage of "ide" command 2629 -43 common/cmd_ide.c No boot device 2630 43 common/cmd_ide.c boot device found 2631 -44 common/cmd_ide.c Device not available 2632 44 common/cmd_ide.c Device available 2633 -45 common/cmd_ide.c wrong partition selected 2634 45 common/cmd_ide.c partition selected 2635 -46 common/cmd_ide.c Unknown partition table 2636 46 common/cmd_ide.c valid partition table found 2637 -47 common/cmd_ide.c Invalid partition type 2638 47 common/cmd_ide.c correct partition type 2639 -48 common/cmd_ide.c Error reading Image Header on boot device 2640 48 common/cmd_ide.c reading Image Header from IDE device OK 2641 -49 common/cmd_ide.c Image header has bad magic number 2642 49 common/cmd_ide.c Image header has correct magic number 2643 -50 common/cmd_ide.c Image header has bad checksum 2644 50 common/cmd_ide.c Image header has correct checksum 2645 -51 common/cmd_ide.c Error reading Image from IDE device 2646 51 common/cmd_ide.c reading Image from IDE device OK 2647 52 common/cmd_nand.c before loading a Image from a NAND device 2648 -53 common/cmd_nand.c Bad usage of "nand" command 2649 53 common/cmd_nand.c correct usage of "nand" command 2650 -54 common/cmd_nand.c No boot device 2651 54 common/cmd_nand.c boot device found 2652 -55 common/cmd_nand.c Unknown Chip ID on boot device 2653 55 common/cmd_nand.c correct chip ID found, device available 2654 -56 common/cmd_nand.c Error reading Image Header on boot device 2655 56 common/cmd_nand.c reading Image Header from NAND device OK 2656 -57 common/cmd_nand.c Image header has bad magic number 2657 57 common/cmd_nand.c Image header has correct magic number 2658 -58 common/cmd_nand.c Error reading Image from NAND device 2659 58 common/cmd_nand.c reading Image from NAND device OK 2660 2661 -60 common/env_common.c Environment has a bad CRC, using default 2662 2663 64 net/eth.c starting with Ethernet configuration. 2664 -64 net/eth.c no Ethernet found. 2665 65 net/eth.c Ethernet found. 2666 2667 -80 common/cmd_net.c usage wrong 2668 80 common/cmd_net.c before calling net_loop() 2669 -81 common/cmd_net.c some error in net_loop() occurred 2670 81 common/cmd_net.c net_loop() back without error 2671 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2672 82 common/cmd_net.c trying automatic boot 2673 83 common/cmd_net.c running "source" command 2674 -83 common/cmd_net.c some error in automatic boot or "source" command 2675 84 common/cmd_net.c end without errors 2676 2677FIT uImage format: 2678 2679 Arg Where When 2680 100 common/cmd_bootm.c Kernel FIT Image has correct format 2681 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2682 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2683 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2684 102 common/cmd_bootm.c Kernel unit name specified 2685 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2686 103 common/cmd_bootm.c Found configuration node 2687 104 common/cmd_bootm.c Got kernel subimage node offset 2688 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2689 105 common/cmd_bootm.c Kernel subimage hash verification OK 2690 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2691 106 common/cmd_bootm.c Architecture check OK 2692 -106 common/cmd_bootm.c Kernel subimage has wrong type 2693 107 common/cmd_bootm.c Kernel subimage type OK 2694 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2695 108 common/cmd_bootm.c Got kernel subimage data/size 2696 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2697 -109 common/cmd_bootm.c Can't get kernel subimage type 2698 -110 common/cmd_bootm.c Can't get kernel subimage comp 2699 -111 common/cmd_bootm.c Can't get kernel subimage os 2700 -112 common/cmd_bootm.c Can't get kernel subimage load address 2701 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2702 2703 120 common/image.c Start initial ramdisk verification 2704 -120 common/image.c Ramdisk FIT image has incorrect format 2705 121 common/image.c Ramdisk FIT image has correct format 2706 122 common/image.c No ramdisk subimage unit name, using configuration 2707 -122 common/image.c Can't get configuration for ramdisk subimage 2708 123 common/image.c Ramdisk unit name specified 2709 -124 common/image.c Can't get ramdisk subimage node offset 2710 125 common/image.c Got ramdisk subimage node offset 2711 -125 common/image.c Ramdisk subimage hash verification failed 2712 126 common/image.c Ramdisk subimage hash verification OK 2713 -126 common/image.c Ramdisk subimage for unsupported architecture 2714 127 common/image.c Architecture check OK 2715 -127 common/image.c Can't get ramdisk subimage data/size 2716 128 common/image.c Got ramdisk subimage data/size 2717 129 common/image.c Can't get ramdisk load address 2718 -129 common/image.c Got ramdisk load address 2719 2720 -130 common/cmd_doc.c Incorrect FIT image format 2721 131 common/cmd_doc.c FIT image format OK 2722 2723 -140 common/cmd_ide.c Incorrect FIT image format 2724 141 common/cmd_ide.c FIT image format OK 2725 2726 -150 common/cmd_nand.c Incorrect FIT image format 2727 151 common/cmd_nand.c FIT image format OK 2728 2729- legacy image format: 2730 CONFIG_IMAGE_FORMAT_LEGACY 2731 enables the legacy image format support in U-Boot. 2732 2733 Default: 2734 enabled if CONFIG_FIT_SIGNATURE is not defined. 2735 2736 CONFIG_DISABLE_IMAGE_LEGACY 2737 disable the legacy image format 2738 2739 This define is introduced, as the legacy image format is 2740 enabled per default for backward compatibility. 2741 2742- Standalone program support: 2743 CONFIG_STANDALONE_LOAD_ADDR 2744 2745 This option defines a board specific value for the 2746 address where standalone program gets loaded, thus 2747 overwriting the architecture dependent default 2748 settings. 2749 2750- Frame Buffer Address: 2751 CONFIG_FB_ADDR 2752 2753 Define CONFIG_FB_ADDR if you want to use specific 2754 address for frame buffer. This is typically the case 2755 when using a graphics controller has separate video 2756 memory. U-Boot will then place the frame buffer at 2757 the given address instead of dynamically reserving it 2758 in system RAM by calling lcd_setmem(), which grabs 2759 the memory for the frame buffer depending on the 2760 configured panel size. 2761 2762 Please see board_init_f function. 2763 2764- Automatic software updates via TFTP server 2765 CONFIG_UPDATE_TFTP 2766 CONFIG_UPDATE_TFTP_CNT_MAX 2767 CONFIG_UPDATE_TFTP_MSEC_MAX 2768 2769 These options enable and control the auto-update feature; 2770 for a more detailed description refer to doc/README.update. 2771 2772- MTD Support (mtdparts command, UBI support) 2773 CONFIG_MTD_DEVICE 2774 2775 Adds the MTD device infrastructure from the Linux kernel. 2776 Needed for mtdparts command support. 2777 2778 CONFIG_MTD_PARTITIONS 2779 2780 Adds the MTD partitioning infrastructure from the Linux 2781 kernel. Needed for UBI support. 2782 2783- UBI support 2784 CONFIG_UBI_SILENCE_MSG 2785 2786 Make the verbose messages from UBI stop printing. This leaves 2787 warnings and errors enabled. 2788 2789 2790 CONFIG_MTD_UBI_WL_THRESHOLD 2791 This parameter defines the maximum difference between the highest 2792 erase counter value and the lowest erase counter value of eraseblocks 2793 of UBI devices. When this threshold is exceeded, UBI starts performing 2794 wear leveling by means of moving data from eraseblock with low erase 2795 counter to eraseblocks with high erase counter. 2796 2797 The default value should be OK for SLC NAND flashes, NOR flashes and 2798 other flashes which have eraseblock life-cycle 100000 or more. 2799 However, in case of MLC NAND flashes which typically have eraseblock 2800 life-cycle less than 10000, the threshold should be lessened (e.g., 2801 to 128 or 256, although it does not have to be power of 2). 2802 2803 default: 4096 2804 2805 CONFIG_MTD_UBI_BEB_LIMIT 2806 This option specifies the maximum bad physical eraseblocks UBI 2807 expects on the MTD device (per 1024 eraseblocks). If the 2808 underlying flash does not admit of bad eraseblocks (e.g. NOR 2809 flash), this value is ignored. 2810 2811 NAND datasheets often specify the minimum and maximum NVM 2812 (Number of Valid Blocks) for the flashes' endurance lifetime. 2813 The maximum expected bad eraseblocks per 1024 eraseblocks 2814 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2815 which gives 20 for most NANDs (MaxNVB is basically the total 2816 count of eraseblocks on the chip). 2817 2818 To put it differently, if this value is 20, UBI will try to 2819 reserve about 1.9% of physical eraseblocks for bad blocks 2820 handling. And that will be 1.9% of eraseblocks on the entire 2821 NAND chip, not just the MTD partition UBI attaches. This means 2822 that if you have, say, a NAND flash chip admits maximum 40 bad 2823 eraseblocks, and it is split on two MTD partitions of the same 2824 size, UBI will reserve 40 eraseblocks when attaching a 2825 partition. 2826 2827 default: 20 2828 2829 CONFIG_MTD_UBI_FASTMAP 2830 Fastmap is a mechanism which allows attaching an UBI device 2831 in nearly constant time. Instead of scanning the whole MTD device it 2832 only has to locate a checkpoint (called fastmap) on the device. 2833 The on-flash fastmap contains all information needed to attach 2834 the device. Using fastmap makes only sense on large devices where 2835 attaching by scanning takes long. UBI will not automatically install 2836 a fastmap on old images, but you can set the UBI parameter 2837 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2838 that fastmap-enabled images are still usable with UBI implementations 2839 without fastmap support. On typical flash devices the whole fastmap 2840 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2841 2842 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2843 Set this parameter to enable fastmap automatically on images 2844 without a fastmap. 2845 default: 0 2846 2847 CONFIG_MTD_UBI_FM_DEBUG 2848 Enable UBI fastmap debug 2849 default: 0 2850 2851- UBIFS support 2852 CONFIG_UBIFS_SILENCE_MSG 2853 2854 Make the verbose messages from UBIFS stop printing. This leaves 2855 warnings and errors enabled. 2856 2857- SPL framework 2858 CONFIG_SPL 2859 Enable building of SPL globally. 2860 2861 CONFIG_SPL_LDSCRIPT 2862 LDSCRIPT for linking the SPL binary. 2863 2864 CONFIG_SPL_MAX_FOOTPRINT 2865 Maximum size in memory allocated to the SPL, BSS included. 2866 When defined, the linker checks that the actual memory 2867 used by SPL from _start to __bss_end does not exceed it. 2868 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2869 must not be both defined at the same time. 2870 2871 CONFIG_SPL_MAX_SIZE 2872 Maximum size of the SPL image (text, data, rodata, and 2873 linker lists sections), BSS excluded. 2874 When defined, the linker checks that the actual size does 2875 not exceed it. 2876 2877 CONFIG_SPL_TEXT_BASE 2878 TEXT_BASE for linking the SPL binary. 2879 2880 CONFIG_SPL_RELOC_TEXT_BASE 2881 Address to relocate to. If unspecified, this is equal to 2882 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2883 2884 CONFIG_SPL_BSS_START_ADDR 2885 Link address for the BSS within the SPL binary. 2886 2887 CONFIG_SPL_BSS_MAX_SIZE 2888 Maximum size in memory allocated to the SPL BSS. 2889 When defined, the linker checks that the actual memory used 2890 by SPL from __bss_start to __bss_end does not exceed it. 2891 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2892 must not be both defined at the same time. 2893 2894 CONFIG_SPL_STACK 2895 Adress of the start of the stack SPL will use 2896 2897 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2898 When defined, SPL will panic() if the image it has 2899 loaded does not have a signature. 2900 Defining this is useful when code which loads images 2901 in SPL cannot guarantee that absolutely all read errors 2902 will be caught. 2903 An example is the LPC32XX MLC NAND driver, which will 2904 consider that a completely unreadable NAND block is bad, 2905 and thus should be skipped silently. 2906 2907 CONFIG_SPL_RELOC_STACK 2908 Adress of the start of the stack SPL will use after 2909 relocation. If unspecified, this is equal to 2910 CONFIG_SPL_STACK. 2911 2912 CONFIG_SYS_SPL_MALLOC_START 2913 Starting address of the malloc pool used in SPL. 2914 When this option is set the full malloc is used in SPL and 2915 it is set up by spl_init() and before that, the simple malloc() 2916 can be used if CONFIG_SYS_MALLOC_F is defined. 2917 2918 CONFIG_SYS_SPL_MALLOC_SIZE 2919 The size of the malloc pool used in SPL. 2920 2921 CONFIG_SPL_FRAMEWORK 2922 Enable the SPL framework under common/. This framework 2923 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2924 NAND loading of the Linux Kernel. 2925 2926 CONFIG_SPL_OS_BOOT 2927 Enable booting directly to an OS from SPL. 2928 See also: doc/README.falcon 2929 2930 CONFIG_SPL_DISPLAY_PRINT 2931 For ARM, enable an optional function to print more information 2932 about the running system. 2933 2934 CONFIG_SPL_INIT_MINIMAL 2935 Arch init code should be built for a very small image 2936 2937 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2938 Partition on the MMC to load U-Boot from when the MMC is being 2939 used in raw mode 2940 2941 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2942 Sector to load kernel uImage from when MMC is being 2943 used in raw mode (for Falcon mode) 2944 2945 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2946 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2947 Sector and number of sectors to load kernel argument 2948 parameters from when MMC is being used in raw mode 2949 (for falcon mode) 2950 2951 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2952 Partition on the MMC to load U-Boot from when the MMC is being 2953 used in fs mode 2954 2955 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2956 Filename to read to load U-Boot when reading from filesystem 2957 2958 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2959 Filename to read to load kernel uImage when reading 2960 from filesystem (for Falcon mode) 2961 2962 CONFIG_SPL_FS_LOAD_ARGS_NAME 2963 Filename to read to load kernel argument parameters 2964 when reading from filesystem (for Falcon mode) 2965 2966 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2967 Set this for NAND SPL on PPC mpc83xx targets, so that 2968 start.S waits for the rest of the SPL to load before 2969 continuing (the hardware starts execution after just 2970 loading the first page rather than the full 4K). 2971 2972 CONFIG_SPL_SKIP_RELOCATE 2973 Avoid SPL relocation 2974 2975 CONFIG_SPL_NAND_BASE 2976 Include nand_base.c in the SPL. Requires 2977 CONFIG_SPL_NAND_DRIVERS. 2978 2979 CONFIG_SPL_NAND_DRIVERS 2980 SPL uses normal NAND drivers, not minimal drivers. 2981 2982 CONFIG_SPL_NAND_ECC 2983 Include standard software ECC in the SPL 2984 2985 CONFIG_SPL_NAND_SIMPLE 2986 Support for NAND boot using simple NAND drivers that 2987 expose the cmd_ctrl() interface. 2988 2989 CONFIG_SPL_UBI 2990 Support for a lightweight UBI (fastmap) scanner and 2991 loader 2992 2993 CONFIG_SPL_NAND_RAW_ONLY 2994 Support to boot only raw u-boot.bin images. Use this only 2995 if you need to save space. 2996 2997 CONFIG_SPL_COMMON_INIT_DDR 2998 Set for common ddr init with serial presence detect in 2999 SPL binary. 3000 3001 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3002 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3003 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3004 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3005 CONFIG_SYS_NAND_ECCBYTES 3006 Defines the size and behavior of the NAND that SPL uses 3007 to read U-Boot 3008 3009 CONFIG_SPL_NAND_BOOT 3010 Add support NAND boot 3011 3012 CONFIG_SYS_NAND_U_BOOT_OFFS 3013 Location in NAND to read U-Boot from 3014 3015 CONFIG_SYS_NAND_U_BOOT_DST 3016 Location in memory to load U-Boot to 3017 3018 CONFIG_SYS_NAND_U_BOOT_SIZE 3019 Size of image to load 3020 3021 CONFIG_SYS_NAND_U_BOOT_START 3022 Entry point in loaded image to jump to 3023 3024 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3025 Define this if you need to first read the OOB and then the 3026 data. This is used, for example, on davinci platforms. 3027 3028 CONFIG_SPL_OMAP3_ID_NAND 3029 Support for an OMAP3-specific set of functions to return the 3030 ID and MFR of the first attached NAND chip, if present. 3031 3032 CONFIG_SPL_RAM_DEVICE 3033 Support for running image already present in ram, in SPL binary 3034 3035 CONFIG_SPL_PAD_TO 3036 Image offset to which the SPL should be padded before appending 3037 the SPL payload. By default, this is defined as 3038 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3039 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3040 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3041 3042 CONFIG_SPL_TARGET 3043 Final target image containing SPL and payload. Some SPLs 3044 use an arch-specific makefile fragment instead, for 3045 example if more than one image needs to be produced. 3046 3047 CONFIG_FIT_SPL_PRINT 3048 Printing information about a FIT image adds quite a bit of 3049 code to SPL. So this is normally disabled in SPL. Use this 3050 option to re-enable it. This will affect the output of the 3051 bootm command when booting a FIT image. 3052 3053- TPL framework 3054 CONFIG_TPL 3055 Enable building of TPL globally. 3056 3057 CONFIG_TPL_PAD_TO 3058 Image offset to which the TPL should be padded before appending 3059 the TPL payload. By default, this is defined as 3060 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3061 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3062 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3063 3064- Interrupt support (PPC): 3065 3066 There are common interrupt_init() and timer_interrupt() 3067 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3068 for CPU specific initialization. interrupt_init_cpu() 3069 should set decrementer_count to appropriate value. If 3070 CPU resets decrementer automatically after interrupt 3071 (ppc4xx) it should set decrementer_count to zero. 3072 timer_interrupt() calls timer_interrupt_cpu() for CPU 3073 specific handling. If board has watchdog / status_led 3074 / other_activity_monitor it works automatically from 3075 general timer_interrupt(). 3076 3077 3078Board initialization settings: 3079------------------------------ 3080 3081During Initialization u-boot calls a number of board specific functions 3082to allow the preparation of board specific prerequisites, e.g. pin setup 3083before drivers are initialized. To enable these callbacks the 3084following configuration macros have to be defined. Currently this is 3085architecture specific, so please check arch/your_architecture/lib/board.c 3086typically in board_init_f() and board_init_r(). 3087 3088- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3089- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3090- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3091- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3092 3093Configuration Settings: 3094----------------------- 3095 3096- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3097 Optionally it can be defined to support 64-bit memory commands. 3098 3099- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3100 undefine this when you're short of memory. 3101 3102- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3103 width of the commands listed in the 'help' command output. 3104 3105- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3106 prompt for user input. 3107 3108- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3109 3110- CONFIG_SYS_PBSIZE: Buffer size for Console output 3111 3112- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3113 3114- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3115 the application (usually a Linux kernel) when it is 3116 booted 3117 3118- CONFIG_SYS_BAUDRATE_TABLE: 3119 List of legal baudrate settings for this board. 3120 3121- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3122 Begin and End addresses of the area used by the 3123 simple memory test. 3124 3125- CONFIG_SYS_ALT_MEMTEST: 3126 Enable an alternate, more extensive memory test. 3127 3128- CONFIG_SYS_MEMTEST_SCRATCH: 3129 Scratch address used by the alternate memory test 3130 You only need to set this if address zero isn't writeable 3131 3132- CONFIG_SYS_MEM_RESERVE_SECURE 3133 Only implemented for ARMv8 for now. 3134 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3135 is substracted from total RAM and won't be reported to OS. 3136 This memory can be used as secure memory. A variable 3137 gd->arch.secure_ram is used to track the location. In systems 3138 the RAM base is not zero, or RAM is divided into banks, 3139 this variable needs to be recalcuated to get the address. 3140 3141- CONFIG_SYS_MEM_TOP_HIDE: 3142 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3143 this specified memory area will get subtracted from the top 3144 (end) of RAM and won't get "touched" at all by U-Boot. By 3145 fixing up gd->ram_size the Linux kernel should gets passed 3146 the now "corrected" memory size and won't touch it either. 3147 This should work for arch/ppc and arch/powerpc. Only Linux 3148 board ports in arch/powerpc with bootwrapper support that 3149 recalculate the memory size from the SDRAM controller setup 3150 will have to get fixed in Linux additionally. 3151 3152 This option can be used as a workaround for the 440EPx/GRx 3153 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3154 be touched. 3155 3156 WARNING: Please make sure that this value is a multiple of 3157 the Linux page size (normally 4k). If this is not the case, 3158 then the end address of the Linux memory will be located at a 3159 non page size aligned address and this could cause major 3160 problems. 3161 3162- CONFIG_SYS_LOADS_BAUD_CHANGE: 3163 Enable temporary baudrate change while serial download 3164 3165- CONFIG_SYS_SDRAM_BASE: 3166 Physical start address of SDRAM. _Must_ be 0 here. 3167 3168- CONFIG_SYS_FLASH_BASE: 3169 Physical start address of Flash memory. 3170 3171- CONFIG_SYS_MONITOR_BASE: 3172 Physical start address of boot monitor code (set by 3173 make config files to be same as the text base address 3174 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3175 CONFIG_SYS_FLASH_BASE when booting from flash. 3176 3177- CONFIG_SYS_MONITOR_LEN: 3178 Size of memory reserved for monitor code, used to 3179 determine _at_compile_time_ (!) if the environment is 3180 embedded within the U-Boot image, or in a separate 3181 flash sector. 3182 3183- CONFIG_SYS_MALLOC_LEN: 3184 Size of DRAM reserved for malloc() use. 3185 3186- CONFIG_SYS_MALLOC_F_LEN 3187 Size of the malloc() pool for use before relocation. If 3188 this is defined, then a very simple malloc() implementation 3189 will become available before relocation. The address is just 3190 below the global data, and the stack is moved down to make 3191 space. 3192 3193 This feature allocates regions with increasing addresses 3194 within the region. calloc() is supported, but realloc() 3195 is not available. free() is supported but does nothing. 3196 The memory will be freed (or in fact just forgotten) when 3197 U-Boot relocates itself. 3198 3199- CONFIG_SYS_MALLOC_SIMPLE 3200 Provides a simple and small malloc() and calloc() for those 3201 boards which do not use the full malloc in SPL (which is 3202 enabled with CONFIG_SYS_SPL_MALLOC_START). 3203 3204- CONFIG_SYS_NONCACHED_MEMORY: 3205 Size of non-cached memory area. This area of memory will be 3206 typically located right below the malloc() area and mapped 3207 uncached in the MMU. This is useful for drivers that would 3208 otherwise require a lot of explicit cache maintenance. For 3209 some drivers it's also impossible to properly maintain the 3210 cache. For example if the regions that need to be flushed 3211 are not a multiple of the cache-line size, *and* padding 3212 cannot be allocated between the regions to align them (i.e. 3213 if the HW requires a contiguous array of regions, and the 3214 size of each region is not cache-aligned), then a flush of 3215 one region may result in overwriting data that hardware has 3216 written to another region in the same cache-line. This can 3217 happen for example in network drivers where descriptors for 3218 buffers are typically smaller than the CPU cache-line (e.g. 3219 16 bytes vs. 32 or 64 bytes). 3220 3221 Non-cached memory is only supported on 32-bit ARM at present. 3222 3223- CONFIG_SYS_BOOTM_LEN: 3224 Normally compressed uImages are limited to an 3225 uncompressed size of 8 MBytes. If this is not enough, 3226 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3227 to adjust this setting to your needs. 3228 3229- CONFIG_SYS_BOOTMAPSZ: 3230 Maximum size of memory mapped by the startup code of 3231 the Linux kernel; all data that must be processed by 3232 the Linux kernel (bd_info, boot arguments, FDT blob if 3233 used) must be put below this limit, unless "bootm_low" 3234 environment variable is defined and non-zero. In such case 3235 all data for the Linux kernel must be between "bootm_low" 3236 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3237 variable "bootm_mapsize" will override the value of 3238 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3239 then the value in "bootm_size" will be used instead. 3240 3241- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3242 Enable initrd_high functionality. If defined then the 3243 initrd_high feature is enabled and the bootm ramdisk subcommand 3244 is enabled. 3245 3246- CONFIG_SYS_BOOT_GET_CMDLINE: 3247 Enables allocating and saving kernel cmdline in space between 3248 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3249 3250- CONFIG_SYS_BOOT_GET_KBD: 3251 Enables allocating and saving a kernel copy of the bd_info in 3252 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3253 3254- CONFIG_SYS_MAX_FLASH_BANKS: 3255 Max number of Flash memory banks 3256 3257- CONFIG_SYS_MAX_FLASH_SECT: 3258 Max number of sectors on a Flash chip 3259 3260- CONFIG_SYS_FLASH_ERASE_TOUT: 3261 Timeout for Flash erase operations (in ms) 3262 3263- CONFIG_SYS_FLASH_WRITE_TOUT: 3264 Timeout for Flash write operations (in ms) 3265 3266- CONFIG_SYS_FLASH_LOCK_TOUT 3267 Timeout for Flash set sector lock bit operation (in ms) 3268 3269- CONFIG_SYS_FLASH_UNLOCK_TOUT 3270 Timeout for Flash clear lock bits operation (in ms) 3271 3272- CONFIG_SYS_FLASH_PROTECTION 3273 If defined, hardware flash sectors protection is used 3274 instead of U-Boot software protection. 3275 3276- CONFIG_SYS_DIRECT_FLASH_TFTP: 3277 3278 Enable TFTP transfers directly to flash memory; 3279 without this option such a download has to be 3280 performed in two steps: (1) download to RAM, and (2) 3281 copy from RAM to flash. 3282 3283 The two-step approach is usually more reliable, since 3284 you can check if the download worked before you erase 3285 the flash, but in some situations (when system RAM is 3286 too limited to allow for a temporary copy of the 3287 downloaded image) this option may be very useful. 3288 3289- CONFIG_SYS_FLASH_CFI: 3290 Define if the flash driver uses extra elements in the 3291 common flash structure for storing flash geometry. 3292 3293- CONFIG_FLASH_CFI_DRIVER 3294 This option also enables the building of the cfi_flash driver 3295 in the drivers directory 3296 3297- CONFIG_FLASH_CFI_MTD 3298 This option enables the building of the cfi_mtd driver 3299 in the drivers directory. The driver exports CFI flash 3300 to the MTD layer. 3301 3302- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3303 Use buffered writes to flash. 3304 3305- CONFIG_FLASH_SPANSION_S29WS_N 3306 s29ws-n MirrorBit flash has non-standard addresses for buffered 3307 write commands. 3308 3309- CONFIG_SYS_FLASH_QUIET_TEST 3310 If this option is defined, the common CFI flash doesn't 3311 print it's warning upon not recognized FLASH banks. This 3312 is useful, if some of the configured banks are only 3313 optionally available. 3314 3315- CONFIG_FLASH_SHOW_PROGRESS 3316 If defined (must be an integer), print out countdown 3317 digits and dots. Recommended value: 45 (9..1) for 80 3318 column displays, 15 (3..1) for 40 column displays. 3319 3320- CONFIG_FLASH_VERIFY 3321 If defined, the content of the flash (destination) is compared 3322 against the source after the write operation. An error message 3323 will be printed when the contents are not identical. 3324 Please note that this option is useless in nearly all cases, 3325 since such flash programming errors usually are detected earlier 3326 while unprotecting/erasing/programming. Please only enable 3327 this option if you really know what you are doing. 3328 3329- CONFIG_SYS_RX_ETH_BUFFER: 3330 Defines the number of Ethernet receive buffers. On some 3331 Ethernet controllers it is recommended to set this value 3332 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3333 buffers can be full shortly after enabling the interface 3334 on high Ethernet traffic. 3335 Defaults to 4 if not defined. 3336 3337- CONFIG_ENV_MAX_ENTRIES 3338 3339 Maximum number of entries in the hash table that is used 3340 internally to store the environment settings. The default 3341 setting is supposed to be generous and should work in most 3342 cases. This setting can be used to tune behaviour; see 3343 lib/hashtable.c for details. 3344 3345- CONFIG_ENV_FLAGS_LIST_DEFAULT 3346- CONFIG_ENV_FLAGS_LIST_STATIC 3347 Enable validation of the values given to environment variables when 3348 calling env set. Variables can be restricted to only decimal, 3349 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3350 the variables can also be restricted to IP address or MAC address. 3351 3352 The format of the list is: 3353 type_attribute = [s|d|x|b|i|m] 3354 access_attribute = [a|r|o|c] 3355 attributes = type_attribute[access_attribute] 3356 entry = variable_name[:attributes] 3357 list = entry[,list] 3358 3359 The type attributes are: 3360 s - String (default) 3361 d - Decimal 3362 x - Hexadecimal 3363 b - Boolean ([1yYtT|0nNfF]) 3364 i - IP address 3365 m - MAC address 3366 3367 The access attributes are: 3368 a - Any (default) 3369 r - Read-only 3370 o - Write-once 3371 c - Change-default 3372 3373 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3374 Define this to a list (string) to define the ".flags" 3375 environment variable in the default or embedded environment. 3376 3377 - CONFIG_ENV_FLAGS_LIST_STATIC 3378 Define this to a list (string) to define validation that 3379 should be done if an entry is not found in the ".flags" 3380 environment variable. To override a setting in the static 3381 list, simply add an entry for the same variable name to the 3382 ".flags" variable. 3383 3384 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3385 regular expression. This allows multiple variables to define the same 3386 flags without explicitly listing them for each variable. 3387 3388- CONFIG_ENV_ACCESS_IGNORE_FORCE 3389 If defined, don't allow the -f switch to env set override variable 3390 access flags. 3391 3392- CONFIG_USE_STDINT 3393 If stdint.h is available with your toolchain you can define this 3394 option to enable it. You can provide option 'USE_STDINT=1' when 3395 building U-Boot to enable this. 3396 3397The following definitions that deal with the placement and management 3398of environment data (variable area); in general, we support the 3399following configurations: 3400 3401- CONFIG_BUILD_ENVCRC: 3402 3403 Builds up envcrc with the target environment so that external utils 3404 may easily extract it and embed it in final U-Boot images. 3405 3406BE CAREFUL! The first access to the environment happens quite early 3407in U-Boot initialization (when we try to get the setting of for the 3408console baudrate). You *MUST* have mapped your NVRAM area then, or 3409U-Boot will hang. 3410 3411Please note that even with NVRAM we still use a copy of the 3412environment in RAM: we could work on NVRAM directly, but we want to 3413keep settings there always unmodified except somebody uses "saveenv" 3414to save the current settings. 3415 3416BE CAREFUL! For some special cases, the local device can not use 3417"saveenv" command. For example, the local device will get the 3418environment stored in a remote NOR flash by SRIO or PCIE link, 3419but it can not erase, write this NOR flash by SRIO or PCIE interface. 3420 3421- CONFIG_NAND_ENV_DST 3422 3423 Defines address in RAM to which the nand_spl code should copy the 3424 environment. If redundant environment is used, it will be copied to 3425 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3426 3427Please note that the environment is read-only until the monitor 3428has been relocated to RAM and a RAM copy of the environment has been 3429created; also, when using EEPROM you will have to use getenv_f() 3430until then to read environment variables. 3431 3432The environment is protected by a CRC32 checksum. Before the monitor 3433is relocated into RAM, as a result of a bad CRC you will be working 3434with the compiled-in default environment - *silently*!!! [This is 3435necessary, because the first environment variable we need is the 3436"baudrate" setting for the console - if we have a bad CRC, we don't 3437have any device yet where we could complain.] 3438 3439Note: once the monitor has been relocated, then it will complain if 3440the default environment is used; a new CRC is computed as soon as you 3441use the "saveenv" command to store a valid environment. 3442 3443- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3444 Echo the inverted Ethernet link state to the fault LED. 3445 3446 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3447 also needs to be defined. 3448 3449- CONFIG_SYS_FAULT_MII_ADDR: 3450 MII address of the PHY to check for the Ethernet link state. 3451 3452- CONFIG_NS16550_MIN_FUNCTIONS: 3453 Define this if you desire to only have use of the NS16550_init 3454 and NS16550_putc functions for the serial driver located at 3455 drivers/serial/ns16550.c. This option is useful for saving 3456 space for already greatly restricted images, including but not 3457 limited to NAND_SPL configurations. 3458 3459- CONFIG_DISPLAY_BOARDINFO 3460 Display information about the board that U-Boot is running on 3461 when U-Boot starts up. The board function checkboard() is called 3462 to do this. 3463 3464- CONFIG_DISPLAY_BOARDINFO_LATE 3465 Similar to the previous option, but display this information 3466 later, once stdio is running and output goes to the LCD, if 3467 present. 3468 3469- CONFIG_BOARD_SIZE_LIMIT: 3470 Maximum size of the U-Boot image. When defined, the 3471 build system checks that the actual size does not 3472 exceed it. 3473 3474Low Level (hardware related) configuration options: 3475--------------------------------------------------- 3476 3477- CONFIG_SYS_CACHELINE_SIZE: 3478 Cache Line Size of the CPU. 3479 3480- CONFIG_SYS_CCSRBAR_DEFAULT: 3481 Default (power-on reset) physical address of CCSR on Freescale 3482 PowerPC SOCs. 3483 3484- CONFIG_SYS_CCSRBAR: 3485 Virtual address of CCSR. On a 32-bit build, this is typically 3486 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3487 3488- CONFIG_SYS_CCSRBAR_PHYS: 3489 Physical address of CCSR. CCSR can be relocated to a new 3490 physical address, if desired. In this case, this macro should 3491 be set to that address. Otherwise, it should be set to the 3492 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3493 is typically relocated on 36-bit builds. It is recommended 3494 that this macro be defined via the _HIGH and _LOW macros: 3495 3496 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3497 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3498 3499- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3500 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3501 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3502 used in assembly code, so it must not contain typecasts or 3503 integer size suffixes (e.g. "ULL"). 3504 3505- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3506 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3507 used in assembly code, so it must not contain typecasts or 3508 integer size suffixes (e.g. "ULL"). 3509 3510- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3511 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3512 forced to a value that ensures that CCSR is not relocated. 3513 3514- Floppy Disk Support: 3515 CONFIG_SYS_FDC_DRIVE_NUMBER 3516 3517 the default drive number (default value 0) 3518 3519 CONFIG_SYS_ISA_IO_STRIDE 3520 3521 defines the spacing between FDC chipset registers 3522 (default value 1) 3523 3524 CONFIG_SYS_ISA_IO_OFFSET 3525 3526 defines the offset of register from address. It 3527 depends on which part of the data bus is connected to 3528 the FDC chipset. (default value 0) 3529 3530 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3531 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3532 default value. 3533 3534 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3535 fdc_hw_init() is called at the beginning of the FDC 3536 setup. fdc_hw_init() must be provided by the board 3537 source code. It is used to make hardware-dependent 3538 initializations. 3539 3540- CONFIG_IDE_AHB: 3541 Most IDE controllers were designed to be connected with PCI 3542 interface. Only few of them were designed for AHB interface. 3543 When software is doing ATA command and data transfer to 3544 IDE devices through IDE-AHB controller, some additional 3545 registers accessing to these kind of IDE-AHB controller 3546 is required. 3547 3548- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3549 DO NOT CHANGE unless you know exactly what you're 3550 doing! (11-4) [MPC8xx systems only] 3551 3552- CONFIG_SYS_INIT_RAM_ADDR: 3553 3554 Start address of memory area that can be used for 3555 initial data and stack; please note that this must be 3556 writable memory that is working WITHOUT special 3557 initialization, i. e. you CANNOT use normal RAM which 3558 will become available only after programming the 3559 memory controller and running certain initialization 3560 sequences. 3561 3562 U-Boot uses the following memory types: 3563 - MPC8xx: IMMR (internal memory of the CPU) 3564 3565- CONFIG_SYS_GBL_DATA_OFFSET: 3566 3567 Offset of the initial data structure in the memory 3568 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3569 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3570 data is located at the end of the available space 3571 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3572 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3573 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3574 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3575 3576 Note: 3577 On the MPC824X (or other systems that use the data 3578 cache for initial memory) the address chosen for 3579 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3580 point to an otherwise UNUSED address space between 3581 the top of RAM and the start of the PCI space. 3582 3583- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3584 3585- CONFIG_SYS_OR_TIMING_SDRAM: 3586 SDRAM timing 3587 3588- CONFIG_SYS_MAMR_PTA: 3589 periodic timer for refresh 3590 3591- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3592 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3593 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3594 CONFIG_SYS_BR1_PRELIM: 3595 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3596 3597- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3598 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3599 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3600 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3601 3602- CONFIG_PCI_ENUM_ONLY 3603 Only scan through and get the devices on the buses. 3604 Don't do any setup work, presumably because someone or 3605 something has already done it, and we don't need to do it 3606 a second time. Useful for platforms that are pre-booted 3607 by coreboot or similar. 3608 3609- CONFIG_PCI_INDIRECT_BRIDGE: 3610 Enable support for indirect PCI bridges. 3611 3612- CONFIG_SYS_SRIO: 3613 Chip has SRIO or not 3614 3615- CONFIG_SRIO1: 3616 Board has SRIO 1 port available 3617 3618- CONFIG_SRIO2: 3619 Board has SRIO 2 port available 3620 3621- CONFIG_SRIO_PCIE_BOOT_MASTER 3622 Board can support master function for Boot from SRIO and PCIE 3623 3624- CONFIG_SYS_SRIOn_MEM_VIRT: 3625 Virtual Address of SRIO port 'n' memory region 3626 3627- CONFIG_SYS_SRIOn_MEM_PHYS: 3628 Physical Address of SRIO port 'n' memory region 3629 3630- CONFIG_SYS_SRIOn_MEM_SIZE: 3631 Size of SRIO port 'n' memory region 3632 3633- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3634 Defined to tell the NAND controller that the NAND chip is using 3635 a 16 bit bus. 3636 Not all NAND drivers use this symbol. 3637 Example of drivers that use it: 3638 - drivers/mtd/nand/ndfc.c 3639 - drivers/mtd/nand/mxc_nand.c 3640 3641- CONFIG_SYS_NDFC_EBC0_CFG 3642 Sets the EBC0_CFG register for the NDFC. If not defined 3643 a default value will be used. 3644 3645- CONFIG_SPD_EEPROM 3646 Get DDR timing information from an I2C EEPROM. Common 3647 with pluggable memory modules such as SODIMMs 3648 3649 SPD_EEPROM_ADDRESS 3650 I2C address of the SPD EEPROM 3651 3652- CONFIG_SYS_SPD_BUS_NUM 3653 If SPD EEPROM is on an I2C bus other than the first 3654 one, specify here. Note that the value must resolve 3655 to something your driver can deal with. 3656 3657- CONFIG_SYS_DDR_RAW_TIMING 3658 Get DDR timing information from other than SPD. Common with 3659 soldered DDR chips onboard without SPD. DDR raw timing 3660 parameters are extracted from datasheet and hard-coded into 3661 header files or board specific files. 3662 3663- CONFIG_FSL_DDR_INTERACTIVE 3664 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3665 3666- CONFIG_FSL_DDR_SYNC_REFRESH 3667 Enable sync of refresh for multiple controllers. 3668 3669- CONFIG_FSL_DDR_BIST 3670 Enable built-in memory test for Freescale DDR controllers. 3671 3672- CONFIG_SYS_83XX_DDR_USES_CS0 3673 Only for 83xx systems. If specified, then DDR should 3674 be configured using CS0 and CS1 instead of CS2 and CS3. 3675 3676- CONFIG_RMII 3677 Enable RMII mode for all FECs. 3678 Note that this is a global option, we can't 3679 have one FEC in standard MII mode and another in RMII mode. 3680 3681- CONFIG_CRC32_VERIFY 3682 Add a verify option to the crc32 command. 3683 The syntax is: 3684 3685 => crc32 -v <address> <count> <crc32> 3686 3687 Where address/count indicate a memory area 3688 and crc32 is the correct crc32 which the 3689 area should have. 3690 3691- CONFIG_LOOPW 3692 Add the "loopw" memory command. This only takes effect if 3693 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3694 3695- CONFIG_MX_CYCLIC 3696 Add the "mdc" and "mwc" memory commands. These are cyclic 3697 "md/mw" commands. 3698 Examples: 3699 3700 => mdc.b 10 4 500 3701 This command will print 4 bytes (10,11,12,13) each 500 ms. 3702 3703 => mwc.l 100 12345678 10 3704 This command will write 12345678 to address 100 all 10 ms. 3705 3706 This only takes effect if the memory commands are activated 3707 globally (CONFIG_CMD_MEMORY). 3708 3709- CONFIG_SKIP_LOWLEVEL_INIT 3710 [ARM, NDS32, MIPS only] If this variable is defined, then certain 3711 low level initializations (like setting up the memory 3712 controller) are omitted and/or U-Boot does not 3713 relocate itself into RAM. 3714 3715 Normally this variable MUST NOT be defined. The only 3716 exception is when U-Boot is loaded (to RAM) by some 3717 other boot loader or by a debugger which performs 3718 these initializations itself. 3719 3720- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3721 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3722 to be skipped. The normal CP15 init (such as enabling the 3723 instruction cache) is still performed. 3724 3725- CONFIG_SPL_BUILD 3726 Modifies the behaviour of start.S when compiling a loader 3727 that is executed before the actual U-Boot. E.g. when 3728 compiling a NAND SPL. 3729 3730- CONFIG_TPL_BUILD 3731 Modifies the behaviour of start.S when compiling a loader 3732 that is executed after the SPL and before the actual U-Boot. 3733 It is loaded by the SPL. 3734 3735- CONFIG_SYS_MPC85XX_NO_RESETVEC 3736 Only for 85xx systems. If this variable is specified, the section 3737 .resetvec is not kept and the section .bootpg is placed in the 3738 previous 4k of the .text section. 3739 3740- CONFIG_ARCH_MAP_SYSMEM 3741 Generally U-Boot (and in particular the md command) uses 3742 effective address. It is therefore not necessary to regard 3743 U-Boot address as virtual addresses that need to be translated 3744 to physical addresses. However, sandbox requires this, since 3745 it maintains its own little RAM buffer which contains all 3746 addressable memory. This option causes some memory accesses 3747 to be mapped through map_sysmem() / unmap_sysmem(). 3748 3749- CONFIG_X86_RESET_VECTOR 3750 If defined, the x86 reset vector code is included. This is not 3751 needed when U-Boot is running from Coreboot. 3752 3753- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3754 Enables the RTC32K OSC on AM33xx based plattforms 3755 3756- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3757 Option to disable subpage write in NAND driver 3758 driver that uses this: 3759 drivers/mtd/nand/davinci_nand.c 3760 3761Freescale QE/FMAN Firmware Support: 3762----------------------------------- 3763 3764The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3765loading of "firmware", which is encoded in the QE firmware binary format. 3766This firmware often needs to be loaded during U-Boot booting, so macros 3767are used to identify the storage device (NOR flash, SPI, etc) and the address 3768within that device. 3769 3770- CONFIG_SYS_FMAN_FW_ADDR 3771 The address in the storage device where the FMAN microcode is located. The 3772 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3773 is also specified. 3774 3775- CONFIG_SYS_QE_FW_ADDR 3776 The address in the storage device where the QE microcode is located. The 3777 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3778 is also specified. 3779 3780- CONFIG_SYS_QE_FMAN_FW_LENGTH 3781 The maximum possible size of the firmware. The firmware binary format 3782 has a field that specifies the actual size of the firmware, but it 3783 might not be possible to read any part of the firmware unless some 3784 local storage is allocated to hold the entire firmware first. 3785 3786- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3787 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3788 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3789 virtual address in NOR flash. 3790 3791- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3792 Specifies that QE/FMAN firmware is located in NAND flash. 3793 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3794 3795- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3796 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3797 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3798 3799- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3800 Specifies that QE/FMAN firmware is located in the remote (master) 3801 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3802 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3803 window->master inbound window->master LAW->the ucode address in 3804 master's memory space. 3805 3806Freescale Layerscape Management Complex Firmware Support: 3807--------------------------------------------------------- 3808The Freescale Layerscape Management Complex (MC) supports the loading of 3809"firmware". 3810This firmware often needs to be loaded during U-Boot booting, so macros 3811are used to identify the storage device (NOR flash, SPI, etc) and the address 3812within that device. 3813 3814- CONFIG_FSL_MC_ENET 3815 Enable the MC driver for Layerscape SoCs. 3816 3817Freescale Layerscape Debug Server Support: 3818------------------------------------------- 3819The Freescale Layerscape Debug Server Support supports the loading of 3820"Debug Server firmware" and triggering SP boot-rom. 3821This firmware often needs to be loaded during U-Boot booting. 3822 3823- CONFIG_SYS_MC_RSV_MEM_ALIGN 3824 Define alignment of reserved memory MC requires 3825 3826Reproducible builds 3827------------------- 3828 3829In order to achieve reproducible builds, timestamps used in the U-Boot build 3830process have to be set to a fixed value. 3831 3832This is done using the SOURCE_DATE_EPOCH environment variable. 3833SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3834option for U-Boot or an environment variable in U-Boot. 3835 3836SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3837 3838Building the Software: 3839====================== 3840 3841Building U-Boot has been tested in several native build environments 3842and in many different cross environments. Of course we cannot support 3843all possibly existing versions of cross development tools in all 3844(potentially obsolete) versions. In case of tool chain problems we 3845recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3846which is extensively used to build and test U-Boot. 3847 3848If you are not using a native environment, it is assumed that you 3849have GNU cross compiling tools available in your path. In this case, 3850you must set the environment variable CROSS_COMPILE in your shell. 3851Note that no changes to the Makefile or any other source files are 3852necessary. For example using the ELDK on a 4xx CPU, please enter: 3853 3854 $ CROSS_COMPILE=ppc_4xx- 3855 $ export CROSS_COMPILE 3856 3857Note: If you wish to generate Windows versions of the utilities in 3858 the tools directory you can use the MinGW toolchain 3859 (http://www.mingw.org). Set your HOST tools to the MinGW 3860 toolchain and execute 'make tools'. For example: 3861 3862 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3863 3864 Binaries such as tools/mkimage.exe will be created which can 3865 be executed on computers running Windows. 3866 3867U-Boot is intended to be simple to build. After installing the 3868sources you must configure U-Boot for one specific board type. This 3869is done by typing: 3870 3871 make NAME_defconfig 3872 3873where "NAME_defconfig" is the name of one of the existing configu- 3874rations; see boards.cfg for supported names. 3875 3876Note: for some board special configuration names may exist; check if 3877 additional information is available from the board vendor; for 3878 instance, the TQM823L systems are available without (standard) 3879 or with LCD support. You can select such additional "features" 3880 when choosing the configuration, i. e. 3881 3882 make TQM823L_defconfig 3883 - will configure for a plain TQM823L, i. e. no LCD support 3884 3885 make TQM823L_LCD_defconfig 3886 - will configure for a TQM823L with U-Boot console on LCD 3887 3888 etc. 3889 3890 3891Finally, type "make all", and you should get some working U-Boot 3892images ready for download to / installation on your system: 3893 3894- "u-boot.bin" is a raw binary image 3895- "u-boot" is an image in ELF binary format 3896- "u-boot.srec" is in Motorola S-Record format 3897 3898By default the build is performed locally and the objects are saved 3899in the source directory. One of the two methods can be used to change 3900this behavior and build U-Boot to some external directory: 3901 39021. Add O= to the make command line invocations: 3903 3904 make O=/tmp/build distclean 3905 make O=/tmp/build NAME_defconfig 3906 make O=/tmp/build all 3907 39082. Set environment variable KBUILD_OUTPUT to point to the desired location: 3909 3910 export KBUILD_OUTPUT=/tmp/build 3911 make distclean 3912 make NAME_defconfig 3913 make all 3914 3915Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3916variable. 3917 3918 3919Please be aware that the Makefiles assume you are using GNU make, so 3920for instance on NetBSD you might need to use "gmake" instead of 3921native "make". 3922 3923 3924If the system board that you have is not listed, then you will need 3925to port U-Boot to your hardware platform. To do this, follow these 3926steps: 3927 39281. Create a new directory to hold your board specific code. Add any 3929 files you need. In your board directory, you will need at least 3930 the "Makefile" and a "<board>.c". 39312. Create a new configuration file "include/configs/<board>.h" for 3932 your board. 39333. If you're porting U-Boot to a new CPU, then also create a new 3934 directory to hold your CPU specific code. Add any files you need. 39354. Run "make <board>_defconfig" with your new name. 39365. Type "make", and you should get a working "u-boot.srec" file 3937 to be installed on your target system. 39386. Debug and solve any problems that might arise. 3939 [Of course, this last step is much harder than it sounds.] 3940 3941 3942Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3943============================================================== 3944 3945If you have modified U-Boot sources (for instance added a new board 3946or support for new devices, a new CPU, etc.) you are expected to 3947provide feedback to the other developers. The feedback normally takes 3948the form of a "patch", i. e. a context diff against a certain (latest 3949official or latest in the git repository) version of U-Boot sources. 3950 3951But before you submit such a patch, please verify that your modifi- 3952cation did not break existing code. At least make sure that *ALL* of 3953the supported boards compile WITHOUT ANY compiler warnings. To do so, 3954just run the buildman script (tools/buildman/buildman), which will 3955configure and build U-Boot for ALL supported system. Be warned, this 3956will take a while. Please see the buildman README, or run 'buildman -H' 3957for documentation. 3958 3959 3960See also "U-Boot Porting Guide" below. 3961 3962 3963Monitor Commands - Overview: 3964============================ 3965 3966go - start application at address 'addr' 3967run - run commands in an environment variable 3968bootm - boot application image from memory 3969bootp - boot image via network using BootP/TFTP protocol 3970bootz - boot zImage from memory 3971tftpboot- boot image via network using TFTP protocol 3972 and env variables "ipaddr" and "serverip" 3973 (and eventually "gatewayip") 3974tftpput - upload a file via network using TFTP protocol 3975rarpboot- boot image via network using RARP/TFTP protocol 3976diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3977loads - load S-Record file over serial line 3978loadb - load binary file over serial line (kermit mode) 3979md - memory display 3980mm - memory modify (auto-incrementing) 3981nm - memory modify (constant address) 3982mw - memory write (fill) 3983cp - memory copy 3984cmp - memory compare 3985crc32 - checksum calculation 3986i2c - I2C sub-system 3987sspi - SPI utility commands 3988base - print or set address offset 3989printenv- print environment variables 3990setenv - set environment variables 3991saveenv - save environment variables to persistent storage 3992protect - enable or disable FLASH write protection 3993erase - erase FLASH memory 3994flinfo - print FLASH memory information 3995nand - NAND memory operations (see doc/README.nand) 3996bdinfo - print Board Info structure 3997iminfo - print header information for application image 3998coninfo - print console devices and informations 3999ide - IDE sub-system 4000loop - infinite loop on address range 4001loopw - infinite write loop on address range 4002mtest - simple RAM test 4003icache - enable or disable instruction cache 4004dcache - enable or disable data cache 4005reset - Perform RESET of the CPU 4006echo - echo args to console 4007version - print monitor version 4008help - print online help 4009? - alias for 'help' 4010 4011 4012Monitor Commands - Detailed Description: 4013======================================== 4014 4015TODO. 4016 4017For now: just type "help <command>". 4018 4019 4020Environment Variables: 4021====================== 4022 4023U-Boot supports user configuration using Environment Variables which 4024can be made persistent by saving to Flash memory. 4025 4026Environment Variables are set using "setenv", printed using 4027"printenv", and saved to Flash using "saveenv". Using "setenv" 4028without a value can be used to delete a variable from the 4029environment. As long as you don't save the environment you are 4030working with an in-memory copy. In case the Flash area containing the 4031environment is erased by accident, a default environment is provided. 4032 4033Some configuration options can be set using Environment Variables. 4034 4035List of environment variables (most likely not complete): 4036 4037 baudrate - see CONFIG_BAUDRATE 4038 4039 bootdelay - see CONFIG_BOOTDELAY 4040 4041 bootcmd - see CONFIG_BOOTCOMMAND 4042 4043 bootargs - Boot arguments when booting an RTOS image 4044 4045 bootfile - Name of the image to load with TFTP 4046 4047 bootm_low - Memory range available for image processing in the bootm 4048 command can be restricted. This variable is given as 4049 a hexadecimal number and defines lowest address allowed 4050 for use by the bootm command. See also "bootm_size" 4051 environment variable. Address defined by "bootm_low" is 4052 also the base of the initial memory mapping for the Linux 4053 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4054 bootm_mapsize. 4055 4056 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4057 This variable is given as a hexadecimal number and it 4058 defines the size of the memory region starting at base 4059 address bootm_low that is accessible by the Linux kernel 4060 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4061 as the default value if it is defined, and bootm_size is 4062 used otherwise. 4063 4064 bootm_size - Memory range available for image processing in the bootm 4065 command can be restricted. This variable is given as 4066 a hexadecimal number and defines the size of the region 4067 allowed for use by the bootm command. See also "bootm_low" 4068 environment variable. 4069 4070 updatefile - Location of the software update file on a TFTP server, used 4071 by the automatic software update feature. Please refer to 4072 documentation in doc/README.update for more details. 4073 4074 autoload - if set to "no" (any string beginning with 'n'), 4075 "bootp" will just load perform a lookup of the 4076 configuration from the BOOTP server, but not try to 4077 load any image using TFTP 4078 4079 autostart - if set to "yes", an image loaded using the "bootp", 4080 "rarpboot", "tftpboot" or "diskboot" commands will 4081 be automatically started (by internally calling 4082 "bootm") 4083 4084 If set to "no", a standalone image passed to the 4085 "bootm" command will be copied to the load address 4086 (and eventually uncompressed), but NOT be started. 4087 This can be used to load and uncompress arbitrary 4088 data. 4089 4090 fdt_high - if set this restricts the maximum address that the 4091 flattened device tree will be copied into upon boot. 4092 For example, if you have a system with 1 GB memory 4093 at physical address 0x10000000, while Linux kernel 4094 only recognizes the first 704 MB as low memory, you 4095 may need to set fdt_high as 0x3C000000 to have the 4096 device tree blob be copied to the maximum address 4097 of the 704 MB low memory, so that Linux kernel can 4098 access it during the boot procedure. 4099 4100 If this is set to the special value 0xFFFFFFFF then 4101 the fdt will not be copied at all on boot. For this 4102 to work it must reside in writable memory, have 4103 sufficient padding on the end of it for u-boot to 4104 add the information it needs into it, and the memory 4105 must be accessible by the kernel. 4106 4107 fdtcontroladdr- if set this is the address of the control flattened 4108 device tree used by U-Boot when CONFIG_OF_CONTROL is 4109 defined. 4110 4111 i2cfast - (PPC405GP|PPC405EP only) 4112 if set to 'y' configures Linux I2C driver for fast 4113 mode (400kHZ). This environment variable is used in 4114 initialization code. So, for changes to be effective 4115 it must be saved and board must be reset. 4116 4117 initrd_high - restrict positioning of initrd images: 4118 If this variable is not set, initrd images will be 4119 copied to the highest possible address in RAM; this 4120 is usually what you want since it allows for 4121 maximum initrd size. If for some reason you want to 4122 make sure that the initrd image is loaded below the 4123 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4124 variable to a value of "no" or "off" or "0". 4125 Alternatively, you can set it to a maximum upper 4126 address to use (U-Boot will still check that it 4127 does not overwrite the U-Boot stack and data). 4128 4129 For instance, when you have a system with 16 MB 4130 RAM, and want to reserve 4 MB from use by Linux, 4131 you can do this by adding "mem=12M" to the value of 4132 the "bootargs" variable. However, now you must make 4133 sure that the initrd image is placed in the first 4134 12 MB as well - this can be done with 4135 4136 setenv initrd_high 00c00000 4137 4138 If you set initrd_high to 0xFFFFFFFF, this is an 4139 indication to U-Boot that all addresses are legal 4140 for the Linux kernel, including addresses in flash 4141 memory. In this case U-Boot will NOT COPY the 4142 ramdisk at all. This may be useful to reduce the 4143 boot time on your system, but requires that this 4144 feature is supported by your Linux kernel. 4145 4146 ipaddr - IP address; needed for tftpboot command 4147 4148 loadaddr - Default load address for commands like "bootp", 4149 "rarpboot", "tftpboot", "loadb" or "diskboot" 4150 4151 loads_echo - see CONFIG_LOADS_ECHO 4152 4153 serverip - TFTP server IP address; needed for tftpboot command 4154 4155 bootretry - see CONFIG_BOOT_RETRY_TIME 4156 4157 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4158 4159 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4160 4161 ethprime - controls which interface is used first. 4162 4163 ethact - controls which interface is currently active. 4164 For example you can do the following 4165 4166 => setenv ethact FEC 4167 => ping 192.168.0.1 # traffic sent on FEC 4168 => setenv ethact SCC 4169 => ping 10.0.0.1 # traffic sent on SCC 4170 4171 ethrotate - When set to "no" U-Boot does not go through all 4172 available network interfaces. 4173 It just stays at the currently selected interface. 4174 4175 netretry - When set to "no" each network operation will 4176 either succeed or fail without retrying. 4177 When set to "once" the network operation will 4178 fail when all the available network interfaces 4179 are tried once without success. 4180 Useful on scripts which control the retry operation 4181 themselves. 4182 4183 npe_ucode - set load address for the NPE microcode 4184 4185 silent_linux - If set then Linux will be told to boot silently, by 4186 changing the console to be empty. If "yes" it will be 4187 made silent. If "no" it will not be made silent. If 4188 unset, then it will be made silent if the U-Boot console 4189 is silent. 4190 4191 tftpsrcp - If this is set, the value is used for TFTP's 4192 UDP source port. 4193 4194 tftpdstp - If this is set, the value is used for TFTP's UDP 4195 destination port instead of the Well Know Port 69. 4196 4197 tftpblocksize - Block size to use for TFTP transfers; if not set, 4198 we use the TFTP server's default block size 4199 4200 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4201 seconds, minimum value is 1000 = 1 second). Defines 4202 when a packet is considered to be lost so it has to 4203 be retransmitted. The default is 5000 = 5 seconds. 4204 Lowering this value may make downloads succeed 4205 faster in networks with high packet loss rates or 4206 with unreliable TFTP servers. 4207 4208 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4209 unit, minimum value = 0). Defines how many timeouts 4210 can happen during a single file transfer before that 4211 transfer is aborted. The default is 10, and 0 means 4212 'no timeouts allowed'. Increasing this value may help 4213 downloads succeed with high packet loss rates, or with 4214 unreliable TFTP servers or client hardware. 4215 4216 vlan - When set to a value < 4095 the traffic over 4217 Ethernet is encapsulated/received over 802.1q 4218 VLAN tagged frames. 4219 4220 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4221 Unsigned value, in milliseconds. If not set, the period will 4222 be either the default (28000), or a value based on 4223 CONFIG_NET_RETRY_COUNT, if defined. This value has 4224 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4225 4226The following image location variables contain the location of images 4227used in booting. The "Image" column gives the role of the image and is 4228not an environment variable name. The other columns are environment 4229variable names. "File Name" gives the name of the file on a TFTP 4230server, "RAM Address" gives the location in RAM the image will be 4231loaded to, and "Flash Location" gives the image's address in NOR 4232flash or offset in NAND flash. 4233 4234*Note* - these variables don't have to be defined for all boards, some 4235boards currently use other variables for these purposes, and some 4236boards use these variables for other purposes. 4237 4238Image File Name RAM Address Flash Location 4239----- --------- ----------- -------------- 4240u-boot u-boot u-boot_addr_r u-boot_addr 4241Linux kernel bootfile kernel_addr_r kernel_addr 4242device tree blob fdtfile fdt_addr_r fdt_addr 4243ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4244 4245The following environment variables may be used and automatically 4246updated by the network boot commands ("bootp" and "rarpboot"), 4247depending the information provided by your boot server: 4248 4249 bootfile - see above 4250 dnsip - IP address of your Domain Name Server 4251 dnsip2 - IP address of your secondary Domain Name Server 4252 gatewayip - IP address of the Gateway (Router) to use 4253 hostname - Target hostname 4254 ipaddr - see above 4255 netmask - Subnet Mask 4256 rootpath - Pathname of the root filesystem on the NFS server 4257 serverip - see above 4258 4259 4260There are two special Environment Variables: 4261 4262 serial# - contains hardware identification information such 4263 as type string and/or serial number 4264 ethaddr - Ethernet address 4265 4266These variables can be set only once (usually during manufacturing of 4267the board). U-Boot refuses to delete or overwrite these variables 4268once they have been set once. 4269 4270 4271Further special Environment Variables: 4272 4273 ver - Contains the U-Boot version string as printed 4274 with the "version" command. This variable is 4275 readonly (see CONFIG_VERSION_VARIABLE). 4276 4277 4278Please note that changes to some configuration parameters may take 4279only effect after the next boot (yes, that's just like Windoze :-). 4280 4281 4282Callback functions for environment variables: 4283--------------------------------------------- 4284 4285For some environment variables, the behavior of u-boot needs to change 4286when their values are changed. This functionality allows functions to 4287be associated with arbitrary variables. On creation, overwrite, or 4288deletion, the callback will provide the opportunity for some side 4289effect to happen or for the change to be rejected. 4290 4291The callbacks are named and associated with a function using the 4292U_BOOT_ENV_CALLBACK macro in your board or driver code. 4293 4294These callbacks are associated with variables in one of two ways. The 4295static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4296in the board configuration to a string that defines a list of 4297associations. The list must be in the following format: 4298 4299 entry = variable_name[:callback_name] 4300 list = entry[,list] 4301 4302If the callback name is not specified, then the callback is deleted. 4303Spaces are also allowed anywhere in the list. 4304 4305Callbacks can also be associated by defining the ".callbacks" variable 4306with the same list format above. Any association in ".callbacks" will 4307override any association in the static list. You can define 4308CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4309".callbacks" environment variable in the default or embedded environment. 4310 4311If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4312regular expression. This allows multiple variables to be connected to 4313the same callback without explicitly listing them all out. 4314 4315 4316Command Line Parsing: 4317===================== 4318 4319There are two different command line parsers available with U-Boot: 4320the old "simple" one, and the much more powerful "hush" shell: 4321 4322Old, simple command line parser: 4323-------------------------------- 4324 4325- supports environment variables (through setenv / saveenv commands) 4326- several commands on one line, separated by ';' 4327- variable substitution using "... ${name} ..." syntax 4328- special characters ('$', ';') can be escaped by prefixing with '\', 4329 for example: 4330 setenv bootcmd bootm \${address} 4331- You can also escape text by enclosing in single apostrophes, for example: 4332 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4333 4334Hush shell: 4335----------- 4336 4337- similar to Bourne shell, with control structures like 4338 if...then...else...fi, for...do...done; while...do...done, 4339 until...do...done, ... 4340- supports environment ("global") variables (through setenv / saveenv 4341 commands) and local shell variables (through standard shell syntax 4342 "name=value"); only environment variables can be used with "run" 4343 command 4344 4345General rules: 4346-------------- 4347 4348(1) If a command line (or an environment variable executed by a "run" 4349 command) contains several commands separated by semicolon, and 4350 one of these commands fails, then the remaining commands will be 4351 executed anyway. 4352 4353(2) If you execute several variables with one call to run (i. e. 4354 calling run with a list of variables as arguments), any failing 4355 command will cause "run" to terminate, i. e. the remaining 4356 variables are not executed. 4357 4358Note for Redundant Ethernet Interfaces: 4359======================================= 4360 4361Some boards come with redundant Ethernet interfaces; U-Boot supports 4362such configurations and is capable of automatic selection of a 4363"working" interface when needed. MAC assignment works as follows: 4364 4365Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4366MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4367"eth1addr" (=>eth1), "eth2addr", ... 4368 4369If the network interface stores some valid MAC address (for instance 4370in SROM), this is used as default address if there is NO correspon- 4371ding setting in the environment; if the corresponding environment 4372variable is set, this overrides the settings in the card; that means: 4373 4374o If the SROM has a valid MAC address, and there is no address in the 4375 environment, the SROM's address is used. 4376 4377o If there is no valid address in the SROM, and a definition in the 4378 environment exists, then the value from the environment variable is 4379 used. 4380 4381o If both the SROM and the environment contain a MAC address, and 4382 both addresses are the same, this MAC address is used. 4383 4384o If both the SROM and the environment contain a MAC address, and the 4385 addresses differ, the value from the environment is used and a 4386 warning is printed. 4387 4388o If neither SROM nor the environment contain a MAC address, an error 4389 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4390 a random, locally-assigned MAC is used. 4391 4392If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4393will be programmed into hardware as part of the initialization process. This 4394may be skipped by setting the appropriate 'ethmacskip' environment variable. 4395The naming convention is as follows: 4396"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4397 4398Image Formats: 4399============== 4400 4401U-Boot is capable of booting (and performing other auxiliary operations on) 4402images in two formats: 4403 4404New uImage format (FIT) 4405----------------------- 4406 4407Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4408to Flattened Device Tree). It allows the use of images with multiple 4409components (several kernels, ramdisks, etc.), with contents protected by 4410SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4411 4412 4413Old uImage format 4414----------------- 4415 4416Old image format is based on binary files which can be basically anything, 4417preceded by a special header; see the definitions in include/image.h for 4418details; basically, the header defines the following image properties: 4419 4420* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4421 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4422 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4423 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4424 INTEGRITY). 4425* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4426 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4427 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4428* Compression Type (uncompressed, gzip, bzip2) 4429* Load Address 4430* Entry Point 4431* Image Name 4432* Image Timestamp 4433 4434The header is marked by a special Magic Number, and both the header 4435and the data portions of the image are secured against corruption by 4436CRC32 checksums. 4437 4438 4439Linux Support: 4440============== 4441 4442Although U-Boot should support any OS or standalone application 4443easily, the main focus has always been on Linux during the design of 4444U-Boot. 4445 4446U-Boot includes many features that so far have been part of some 4447special "boot loader" code within the Linux kernel. Also, any 4448"initrd" images to be used are no longer part of one big Linux image; 4449instead, kernel and "initrd" are separate images. This implementation 4450serves several purposes: 4451 4452- the same features can be used for other OS or standalone 4453 applications (for instance: using compressed images to reduce the 4454 Flash memory footprint) 4455 4456- it becomes much easier to port new Linux kernel versions because 4457 lots of low-level, hardware dependent stuff are done by U-Boot 4458 4459- the same Linux kernel image can now be used with different "initrd" 4460 images; of course this also means that different kernel images can 4461 be run with the same "initrd". This makes testing easier (you don't 4462 have to build a new "zImage.initrd" Linux image when you just 4463 change a file in your "initrd"). Also, a field-upgrade of the 4464 software is easier now. 4465 4466 4467Linux HOWTO: 4468============ 4469 4470Porting Linux to U-Boot based systems: 4471--------------------------------------- 4472 4473U-Boot cannot save you from doing all the necessary modifications to 4474configure the Linux device drivers for use with your target hardware 4475(no, we don't intend to provide a full virtual machine interface to 4476Linux :-). 4477 4478But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4479 4480Just make sure your machine specific header file (for instance 4481include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4482Information structure as we define in include/asm-<arch>/u-boot.h, 4483and make sure that your definition of IMAP_ADDR uses the same value 4484as your U-Boot configuration in CONFIG_SYS_IMMR. 4485 4486Note that U-Boot now has a driver model, a unified model for drivers. 4487If you are adding a new driver, plumb it into driver model. If there 4488is no uclass available, you are encouraged to create one. See 4489doc/driver-model. 4490 4491 4492Configuring the Linux kernel: 4493----------------------------- 4494 4495No specific requirements for U-Boot. Make sure you have some root 4496device (initial ramdisk, NFS) for your target system. 4497 4498 4499Building a Linux Image: 4500----------------------- 4501 4502With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4503not used. If you use recent kernel source, a new build target 4504"uImage" will exist which automatically builds an image usable by 4505U-Boot. Most older kernels also have support for a "pImage" target, 4506which was introduced for our predecessor project PPCBoot and uses a 4507100% compatible format. 4508 4509Example: 4510 4511 make TQM850L_defconfig 4512 make oldconfig 4513 make dep 4514 make uImage 4515 4516The "uImage" build target uses a special tool (in 'tools/mkimage') to 4517encapsulate a compressed Linux kernel image with header information, 4518CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4519 4520* build a standard "vmlinux" kernel image (in ELF binary format): 4521 4522* convert the kernel into a raw binary image: 4523 4524 ${CROSS_COMPILE}-objcopy -O binary \ 4525 -R .note -R .comment \ 4526 -S vmlinux linux.bin 4527 4528* compress the binary image: 4529 4530 gzip -9 linux.bin 4531 4532* package compressed binary image for U-Boot: 4533 4534 mkimage -A ppc -O linux -T kernel -C gzip \ 4535 -a 0 -e 0 -n "Linux Kernel Image" \ 4536 -d linux.bin.gz uImage 4537 4538 4539The "mkimage" tool can also be used to create ramdisk images for use 4540with U-Boot, either separated from the Linux kernel image, or 4541combined into one file. "mkimage" encapsulates the images with a 64 4542byte header containing information about target architecture, 4543operating system, image type, compression method, entry points, time 4544stamp, CRC32 checksums, etc. 4545 4546"mkimage" can be called in two ways: to verify existing images and 4547print the header information, or to build new images. 4548 4549In the first form (with "-l" option) mkimage lists the information 4550contained in the header of an existing U-Boot image; this includes 4551checksum verification: 4552 4553 tools/mkimage -l image 4554 -l ==> list image header information 4555 4556The second form (with "-d" option) is used to build a U-Boot image 4557from a "data file" which is used as image payload: 4558 4559 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4560 -n name -d data_file image 4561 -A ==> set architecture to 'arch' 4562 -O ==> set operating system to 'os' 4563 -T ==> set image type to 'type' 4564 -C ==> set compression type 'comp' 4565 -a ==> set load address to 'addr' (hex) 4566 -e ==> set entry point to 'ep' (hex) 4567 -n ==> set image name to 'name' 4568 -d ==> use image data from 'datafile' 4569 4570Right now, all Linux kernels for PowerPC systems use the same load 4571address (0x00000000), but the entry point address depends on the 4572kernel version: 4573 4574- 2.2.x kernels have the entry point at 0x0000000C, 4575- 2.3.x and later kernels have the entry point at 0x00000000. 4576 4577So a typical call to build a U-Boot image would read: 4578 4579 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4580 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4581 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4582 > examples/uImage.TQM850L 4583 Image Name: 2.4.4 kernel for TQM850L 4584 Created: Wed Jul 19 02:34:59 2000 4585 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4586 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4587 Load Address: 0x00000000 4588 Entry Point: 0x00000000 4589 4590To verify the contents of the image (or check for corruption): 4591 4592 -> tools/mkimage -l examples/uImage.TQM850L 4593 Image Name: 2.4.4 kernel for TQM850L 4594 Created: Wed Jul 19 02:34:59 2000 4595 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4596 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4597 Load Address: 0x00000000 4598 Entry Point: 0x00000000 4599 4600NOTE: for embedded systems where boot time is critical you can trade 4601speed for memory and install an UNCOMPRESSED image instead: this 4602needs more space in Flash, but boots much faster since it does not 4603need to be uncompressed: 4604 4605 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4606 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4607 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4608 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4609 > examples/uImage.TQM850L-uncompressed 4610 Image Name: 2.4.4 kernel for TQM850L 4611 Created: Wed Jul 19 02:34:59 2000 4612 Image Type: PowerPC Linux Kernel Image (uncompressed) 4613 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4614 Load Address: 0x00000000 4615 Entry Point: 0x00000000 4616 4617 4618Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4619when your kernel is intended to use an initial ramdisk: 4620 4621 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4622 > -A ppc -O linux -T ramdisk -C gzip \ 4623 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4624 Image Name: Simple Ramdisk Image 4625 Created: Wed Jan 12 14:01:50 2000 4626 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4627 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4628 Load Address: 0x00000000 4629 Entry Point: 0x00000000 4630 4631The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4632option performs the converse operation of the mkimage's second form (the "-d" 4633option). Given an image built by mkimage, the dumpimage extracts a "data file" 4634from the image: 4635 4636 tools/dumpimage -i image -T type -p position data_file 4637 -i ==> extract from the 'image' a specific 'data_file' 4638 -T ==> set image type to 'type' 4639 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4640 4641 4642Installing a Linux Image: 4643------------------------- 4644 4645To downloading a U-Boot image over the serial (console) interface, 4646you must convert the image to S-Record format: 4647 4648 objcopy -I binary -O srec examples/image examples/image.srec 4649 4650The 'objcopy' does not understand the information in the U-Boot 4651image header, so the resulting S-Record file will be relative to 4652address 0x00000000. To load it to a given address, you need to 4653specify the target address as 'offset' parameter with the 'loads' 4654command. 4655 4656Example: install the image to address 0x40100000 (which on the 4657TQM8xxL is in the first Flash bank): 4658 4659 => erase 40100000 401FFFFF 4660 4661 .......... done 4662 Erased 8 sectors 4663 4664 => loads 40100000 4665 ## Ready for S-Record download ... 4666 ~>examples/image.srec 4667 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4668 ... 4669 15989 15990 15991 15992 4670 [file transfer complete] 4671 [connected] 4672 ## Start Addr = 0x00000000 4673 4674 4675You can check the success of the download using the 'iminfo' command; 4676this includes a checksum verification so you can be sure no data 4677corruption happened: 4678 4679 => imi 40100000 4680 4681 ## Checking Image at 40100000 ... 4682 Image Name: 2.2.13 for initrd on TQM850L 4683 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4684 Data Size: 335725 Bytes = 327 kB = 0 MB 4685 Load Address: 00000000 4686 Entry Point: 0000000c 4687 Verifying Checksum ... OK 4688 4689 4690Boot Linux: 4691----------- 4692 4693The "bootm" command is used to boot an application that is stored in 4694memory (RAM or Flash). In case of a Linux kernel image, the contents 4695of the "bootargs" environment variable is passed to the kernel as 4696parameters. You can check and modify this variable using the 4697"printenv" and "setenv" commands: 4698 4699 4700 => printenv bootargs 4701 bootargs=root=/dev/ram 4702 4703 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4704 4705 => printenv bootargs 4706 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4707 4708 => bootm 40020000 4709 ## Booting Linux kernel at 40020000 ... 4710 Image Name: 2.2.13 for NFS on TQM850L 4711 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4712 Data Size: 381681 Bytes = 372 kB = 0 MB 4713 Load Address: 00000000 4714 Entry Point: 0000000c 4715 Verifying Checksum ... OK 4716 Uncompressing Kernel Image ... OK 4717 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 4718 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4719 time_init: decrementer frequency = 187500000/60 4720 Calibrating delay loop... 49.77 BogoMIPS 4721 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4722 ... 4723 4724If you want to boot a Linux kernel with initial RAM disk, you pass 4725the memory addresses of both the kernel and the initrd image (PPBCOOT 4726format!) to the "bootm" command: 4727 4728 => imi 40100000 40200000 4729 4730 ## Checking Image at 40100000 ... 4731 Image Name: 2.2.13 for initrd on TQM850L 4732 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4733 Data Size: 335725 Bytes = 327 kB = 0 MB 4734 Load Address: 00000000 4735 Entry Point: 0000000c 4736 Verifying Checksum ... OK 4737 4738 ## Checking Image at 40200000 ... 4739 Image Name: Simple Ramdisk Image 4740 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4741 Data Size: 566530 Bytes = 553 kB = 0 MB 4742 Load Address: 00000000 4743 Entry Point: 00000000 4744 Verifying Checksum ... OK 4745 4746 => bootm 40100000 40200000 4747 ## Booting Linux kernel at 40100000 ... 4748 Image Name: 2.2.13 for initrd on TQM850L 4749 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4750 Data Size: 335725 Bytes = 327 kB = 0 MB 4751 Load Address: 00000000 4752 Entry Point: 0000000c 4753 Verifying Checksum ... OK 4754 Uncompressing Kernel Image ... OK 4755 ## Loading RAMDisk Image at 40200000 ... 4756 Image Name: Simple Ramdisk Image 4757 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4758 Data Size: 566530 Bytes = 553 kB = 0 MB 4759 Load Address: 00000000 4760 Entry Point: 00000000 4761 Verifying Checksum ... OK 4762 Loading Ramdisk ... OK 4763 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 4764 Boot arguments: root=/dev/ram 4765 time_init: decrementer frequency = 187500000/60 4766 Calibrating delay loop... 49.77 BogoMIPS 4767 ... 4768 RAMDISK: Compressed image found at block 0 4769 VFS: Mounted root (ext2 filesystem). 4770 4771 bash# 4772 4773Boot Linux and pass a flat device tree: 4774----------- 4775 4776First, U-Boot must be compiled with the appropriate defines. See the section 4777titled "Linux Kernel Interface" above for a more in depth explanation. The 4778following is an example of how to start a kernel and pass an updated 4779flat device tree: 4780 4781=> print oftaddr 4782oftaddr=0x300000 4783=> print oft 4784oft=oftrees/mpc8540ads.dtb 4785=> tftp $oftaddr $oft 4786Speed: 1000, full duplex 4787Using TSEC0 device 4788TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4789Filename 'oftrees/mpc8540ads.dtb'. 4790Load address: 0x300000 4791Loading: # 4792done 4793Bytes transferred = 4106 (100a hex) 4794=> tftp $loadaddr $bootfile 4795Speed: 1000, full duplex 4796Using TSEC0 device 4797TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4798Filename 'uImage'. 4799Load address: 0x200000 4800Loading:############ 4801done 4802Bytes transferred = 1029407 (fb51f hex) 4803=> print loadaddr 4804loadaddr=200000 4805=> print oftaddr 4806oftaddr=0x300000 4807=> bootm $loadaddr - $oftaddr 4808## Booting image at 00200000 ... 4809 Image Name: Linux-2.6.17-dirty 4810 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4811 Data Size: 1029343 Bytes = 1005.2 kB 4812 Load Address: 00000000 4813 Entry Point: 00000000 4814 Verifying Checksum ... OK 4815 Uncompressing Kernel Image ... OK 4816Booting using flat device tree at 0x300000 4817Using MPC85xx ADS machine description 4818Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4819[snip] 4820 4821 4822More About U-Boot Image Types: 4823------------------------------ 4824 4825U-Boot supports the following image types: 4826 4827 "Standalone Programs" are directly runnable in the environment 4828 provided by U-Boot; it is expected that (if they behave 4829 well) you can continue to work in U-Boot after return from 4830 the Standalone Program. 4831 "OS Kernel Images" are usually images of some Embedded OS which 4832 will take over control completely. Usually these programs 4833 will install their own set of exception handlers, device 4834 drivers, set up the MMU, etc. - this means, that you cannot 4835 expect to re-enter U-Boot except by resetting the CPU. 4836 "RAMDisk Images" are more or less just data blocks, and their 4837 parameters (address, size) are passed to an OS kernel that is 4838 being started. 4839 "Multi-File Images" contain several images, typically an OS 4840 (Linux) kernel image and one or more data images like 4841 RAMDisks. This construct is useful for instance when you want 4842 to boot over the network using BOOTP etc., where the boot 4843 server provides just a single image file, but you want to get 4844 for instance an OS kernel and a RAMDisk image. 4845 4846 "Multi-File Images" start with a list of image sizes, each 4847 image size (in bytes) specified by an "uint32_t" in network 4848 byte order. This list is terminated by an "(uint32_t)0". 4849 Immediately after the terminating 0 follow the images, one by 4850 one, all aligned on "uint32_t" boundaries (size rounded up to 4851 a multiple of 4 bytes). 4852 4853 "Firmware Images" are binary images containing firmware (like 4854 U-Boot or FPGA images) which usually will be programmed to 4855 flash memory. 4856 4857 "Script files" are command sequences that will be executed by 4858 U-Boot's command interpreter; this feature is especially 4859 useful when you configure U-Boot to use a real shell (hush) 4860 as command interpreter. 4861 4862Booting the Linux zImage: 4863------------------------- 4864 4865On some platforms, it's possible to boot Linux zImage. This is done 4866using the "bootz" command. The syntax of "bootz" command is the same 4867as the syntax of "bootm" command. 4868 4869Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4870kernel with raw initrd images. The syntax is slightly different, the 4871address of the initrd must be augmented by it's size, in the following 4872format: "<initrd addres>:<initrd size>". 4873 4874 4875Standalone HOWTO: 4876================= 4877 4878One of the features of U-Boot is that you can dynamically load and 4879run "standalone" applications, which can use some resources of 4880U-Boot like console I/O functions or interrupt services. 4881 4882Two simple examples are included with the sources: 4883 4884"Hello World" Demo: 4885------------------- 4886 4887'examples/hello_world.c' contains a small "Hello World" Demo 4888application; it is automatically compiled when you build U-Boot. 4889It's configured to run at address 0x00040004, so you can play with it 4890like that: 4891 4892 => loads 4893 ## Ready for S-Record download ... 4894 ~>examples/hello_world.srec 4895 1 2 3 4 5 6 7 8 9 10 11 ... 4896 [file transfer complete] 4897 [connected] 4898 ## Start Addr = 0x00040004 4899 4900 => go 40004 Hello World! This is a test. 4901 ## Starting application at 0x00040004 ... 4902 Hello World 4903 argc = 7 4904 argv[0] = "40004" 4905 argv[1] = "Hello" 4906 argv[2] = "World!" 4907 argv[3] = "This" 4908 argv[4] = "is" 4909 argv[5] = "a" 4910 argv[6] = "test." 4911 argv[7] = "<NULL>" 4912 Hit any key to exit ... 4913 4914 ## Application terminated, rc = 0x0 4915 4916Another example, which demonstrates how to register a CPM interrupt 4917handler with the U-Boot code, can be found in 'examples/timer.c'. 4918Here, a CPM timer is set up to generate an interrupt every second. 4919The interrupt service routine is trivial, just printing a '.' 4920character, but this is just a demo program. The application can be 4921controlled by the following keys: 4922 4923 ? - print current values og the CPM Timer registers 4924 b - enable interrupts and start timer 4925 e - stop timer and disable interrupts 4926 q - quit application 4927 4928 => loads 4929 ## Ready for S-Record download ... 4930 ~>examples/timer.srec 4931 1 2 3 4 5 6 7 8 9 10 11 ... 4932 [file transfer complete] 4933 [connected] 4934 ## Start Addr = 0x00040004 4935 4936 => go 40004 4937 ## Starting application at 0x00040004 ... 4938 TIMERS=0xfff00980 4939 Using timer 1 4940 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4941 4942Hit 'b': 4943 [q, b, e, ?] Set interval 1000000 us 4944 Enabling timer 4945Hit '?': 4946 [q, b, e, ?] ........ 4947 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4948Hit '?': 4949 [q, b, e, ?] . 4950 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4951Hit '?': 4952 [q, b, e, ?] . 4953 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4954Hit '?': 4955 [q, b, e, ?] . 4956 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4957Hit 'e': 4958 [q, b, e, ?] ...Stopping timer 4959Hit 'q': 4960 [q, b, e, ?] ## Application terminated, rc = 0x0 4961 4962 4963Minicom warning: 4964================ 4965 4966Over time, many people have reported problems when trying to use the 4967"minicom" terminal emulation program for serial download. I (wd) 4968consider minicom to be broken, and recommend not to use it. Under 4969Unix, I recommend to use C-Kermit for general purpose use (and 4970especially for kermit binary protocol download ("loadb" command), and 4971use "cu" for S-Record download ("loads" command). See 4972http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4973for help with kermit. 4974 4975 4976Nevertheless, if you absolutely want to use it try adding this 4977configuration to your "File transfer protocols" section: 4978 4979 Name Program Name U/D FullScr IO-Red. Multi 4980 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4981 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4982 4983 4984NetBSD Notes: 4985============= 4986 4987Starting at version 0.9.2, U-Boot supports NetBSD both as host 4988(build U-Boot) and target system (boots NetBSD/mpc8xx). 4989 4990Building requires a cross environment; it is known to work on 4991NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4992need gmake since the Makefiles are not compatible with BSD make). 4993Note that the cross-powerpc package does not install include files; 4994attempting to build U-Boot will fail because <machine/ansi.h> is 4995missing. This file has to be installed and patched manually: 4996 4997 # cd /usr/pkg/cross/powerpc-netbsd/include 4998 # mkdir powerpc 4999 # ln -s powerpc machine 5000 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5001 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5002 5003Native builds *don't* work due to incompatibilities between native 5004and U-Boot include files. 5005 5006Booting assumes that (the first part of) the image booted is a 5007stage-2 loader which in turn loads and then invokes the kernel 5008proper. Loader sources will eventually appear in the NetBSD source 5009tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5010meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5011 5012 5013Implementation Internals: 5014========================= 5015 5016The following is not intended to be a complete description of every 5017implementation detail. However, it should help to understand the 5018inner workings of U-Boot and make it easier to port it to custom 5019hardware. 5020 5021 5022Initial Stack, Global Data: 5023--------------------------- 5024 5025The implementation of U-Boot is complicated by the fact that U-Boot 5026starts running out of ROM (flash memory), usually without access to 5027system RAM (because the memory controller is not initialized yet). 5028This means that we don't have writable Data or BSS segments, and BSS 5029is not initialized as zero. To be able to get a C environment working 5030at all, we have to allocate at least a minimal stack. Implementation 5031options for this are defined and restricted by the CPU used: Some CPU 5032models provide on-chip memory (like the IMMR area on MPC8xx and 5033MPC826x processors), on others (parts of) the data cache can be 5034locked as (mis-) used as memory, etc. 5035 5036 Chris Hallinan posted a good summary of these issues to the 5037 U-Boot mailing list: 5038 5039 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5040 From: "Chris Hallinan" <clh@net1plus.com> 5041 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5042 ... 5043 5044 Correct me if I'm wrong, folks, but the way I understand it 5045 is this: Using DCACHE as initial RAM for Stack, etc, does not 5046 require any physical RAM backing up the cache. The cleverness 5047 is that the cache is being used as a temporary supply of 5048 necessary storage before the SDRAM controller is setup. It's 5049 beyond the scope of this list to explain the details, but you 5050 can see how this works by studying the cache architecture and 5051 operation in the architecture and processor-specific manuals. 5052 5053 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5054 is another option for the system designer to use as an 5055 initial stack/RAM area prior to SDRAM being available. Either 5056 option should work for you. Using CS 4 should be fine if your 5057 board designers haven't used it for something that would 5058 cause you grief during the initial boot! It is frequently not 5059 used. 5060 5061 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5062 with your processor/board/system design. The default value 5063 you will find in any recent u-boot distribution in 5064 walnut.h should work for you. I'd set it to a value larger 5065 than your SDRAM module. If you have a 64MB SDRAM module, set 5066 it above 400_0000. Just make sure your board has no resources 5067 that are supposed to respond to that address! That code in 5068 start.S has been around a while and should work as is when 5069 you get the config right. 5070 5071 -Chris Hallinan 5072 DS4.COM, Inc. 5073 5074It is essential to remember this, since it has some impact on the C 5075code for the initialization procedures: 5076 5077* Initialized global data (data segment) is read-only. Do not attempt 5078 to write it. 5079 5080* Do not use any uninitialized global data (or implicitly initialized 5081 as zero data - BSS segment) at all - this is undefined, initiali- 5082 zation is performed later (when relocating to RAM). 5083 5084* Stack space is very limited. Avoid big data buffers or things like 5085 that. 5086 5087Having only the stack as writable memory limits means we cannot use 5088normal global data to share information between the code. But it 5089turned out that the implementation of U-Boot can be greatly 5090simplified by making a global data structure (gd_t) available to all 5091functions. We could pass a pointer to this data as argument to _all_ 5092functions, but this would bloat the code. Instead we use a feature of 5093the GCC compiler (Global Register Variables) to share the data: we 5094place a pointer (gd) to the global data into a register which we 5095reserve for this purpose. 5096 5097When choosing a register for such a purpose we are restricted by the 5098relevant (E)ABI specifications for the current architecture, and by 5099GCC's implementation. 5100 5101For PowerPC, the following registers have specific use: 5102 R1: stack pointer 5103 R2: reserved for system use 5104 R3-R4: parameter passing and return values 5105 R5-R10: parameter passing 5106 R13: small data area pointer 5107 R30: GOT pointer 5108 R31: frame pointer 5109 5110 (U-Boot also uses R12 as internal GOT pointer. r12 5111 is a volatile register so r12 needs to be reset when 5112 going back and forth between asm and C) 5113 5114 ==> U-Boot will use R2 to hold a pointer to the global data 5115 5116 Note: on PPC, we could use a static initializer (since the 5117 address of the global data structure is known at compile time), 5118 but it turned out that reserving a register results in somewhat 5119 smaller code - although the code savings are not that big (on 5120 average for all boards 752 bytes for the whole U-Boot image, 5121 624 text + 127 data). 5122 5123On ARM, the following registers are used: 5124 5125 R0: function argument word/integer result 5126 R1-R3: function argument word 5127 R9: platform specific 5128 R10: stack limit (used only if stack checking is enabled) 5129 R11: argument (frame) pointer 5130 R12: temporary workspace 5131 R13: stack pointer 5132 R14: link register 5133 R15: program counter 5134 5135 ==> U-Boot will use R9 to hold a pointer to the global data 5136 5137 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5138 5139On Nios II, the ABI is documented here: 5140 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5141 5142 ==> U-Boot will use gp to hold a pointer to the global data 5143 5144 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5145 to access small data sections, so gp is free. 5146 5147On NDS32, the following registers are used: 5148 5149 R0-R1: argument/return 5150 R2-R5: argument 5151 R15: temporary register for assembler 5152 R16: trampoline register 5153 R28: frame pointer (FP) 5154 R29: global pointer (GP) 5155 R30: link register (LP) 5156 R31: stack pointer (SP) 5157 PC: program counter (PC) 5158 5159 ==> U-Boot will use R10 to hold a pointer to the global data 5160 5161NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5162or current versions of GCC may "optimize" the code too much. 5163 5164Memory Management: 5165------------------ 5166 5167U-Boot runs in system state and uses physical addresses, i.e. the 5168MMU is not used either for address mapping nor for memory protection. 5169 5170The available memory is mapped to fixed addresses using the memory 5171controller. In this process, a contiguous block is formed for each 5172memory type (Flash, SDRAM, SRAM), even when it consists of several 5173physical memory banks. 5174 5175U-Boot is installed in the first 128 kB of the first Flash bank (on 5176TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5177booting and sizing and initializing DRAM, the code relocates itself 5178to the upper end of DRAM. Immediately below the U-Boot code some 5179memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5180configuration setting]. Below that, a structure with global Board 5181Info data is placed, followed by the stack (growing downward). 5182 5183Additionally, some exception handler code is copied to the low 8 kB 5184of DRAM (0x00000000 ... 0x00001FFF). 5185 5186So a typical memory configuration with 16 MB of DRAM could look like 5187this: 5188 5189 0x0000 0000 Exception Vector code 5190 : 5191 0x0000 1FFF 5192 0x0000 2000 Free for Application Use 5193 : 5194 : 5195 5196 : 5197 : 5198 0x00FB FF20 Monitor Stack (Growing downward) 5199 0x00FB FFAC Board Info Data and permanent copy of global data 5200 0x00FC 0000 Malloc Arena 5201 : 5202 0x00FD FFFF 5203 0x00FE 0000 RAM Copy of Monitor Code 5204 ... eventually: LCD or video framebuffer 5205 ... eventually: pRAM (Protected RAM - unchanged by reset) 5206 0x00FF FFFF [End of RAM] 5207 5208 5209System Initialization: 5210---------------------- 5211 5212In the reset configuration, U-Boot starts at the reset entry point 5213(on most PowerPC systems at address 0x00000100). Because of the reset 5214configuration for CS0# this is a mirror of the on board Flash memory. 5215To be able to re-map memory U-Boot then jumps to its link address. 5216To be able to implement the initialization code in C, a (small!) 5217initial stack is set up in the internal Dual Ported RAM (in case CPUs 5218which provide such a feature like), or in a locked part of the data 5219cache. After that, U-Boot initializes the CPU core, the caches and 5220the SIU. 5221 5222Next, all (potentially) available memory banks are mapped using a 5223preliminary mapping. For example, we put them on 512 MB boundaries 5224(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5225on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5226programmed for SDRAM access. Using the temporary configuration, a 5227simple memory test is run that determines the size of the SDRAM 5228banks. 5229 5230When there is more than one SDRAM bank, and the banks are of 5231different size, the largest is mapped first. For equal size, the first 5232bank (CS2#) is mapped first. The first mapping is always for address 52330x00000000, with any additional banks following immediately to create 5234contiguous memory starting from 0. 5235 5236Then, the monitor installs itself at the upper end of the SDRAM area 5237and allocates memory for use by malloc() and for the global Board 5238Info data; also, the exception vector code is copied to the low RAM 5239pages, and the final stack is set up. 5240 5241Only after this relocation will you have a "normal" C environment; 5242until that you are restricted in several ways, mostly because you are 5243running from ROM, and because the code will have to be relocated to a 5244new address in RAM. 5245 5246 5247U-Boot Porting Guide: 5248---------------------- 5249 5250[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5251list, October 2002] 5252 5253 5254int main(int argc, char *argv[]) 5255{ 5256 sighandler_t no_more_time; 5257 5258 signal(SIGALRM, no_more_time); 5259 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5260 5261 if (available_money > available_manpower) { 5262 Pay consultant to port U-Boot; 5263 return 0; 5264 } 5265 5266 Download latest U-Boot source; 5267 5268 Subscribe to u-boot mailing list; 5269 5270 if (clueless) 5271 email("Hi, I am new to U-Boot, how do I get started?"); 5272 5273 while (learning) { 5274 Read the README file in the top level directory; 5275 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5276 Read applicable doc/*.README; 5277 Read the source, Luke; 5278 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5279 } 5280 5281 if (available_money > toLocalCurrency ($2500)) 5282 Buy a BDI3000; 5283 else 5284 Add a lot of aggravation and time; 5285 5286 if (a similar board exists) { /* hopefully... */ 5287 cp -a board/<similar> board/<myboard> 5288 cp include/configs/<similar>.h include/configs/<myboard>.h 5289 } else { 5290 Create your own board support subdirectory; 5291 Create your own board include/configs/<myboard>.h file; 5292 } 5293 Edit new board/<myboard> files 5294 Edit new include/configs/<myboard>.h 5295 5296 while (!accepted) { 5297 while (!running) { 5298 do { 5299 Add / modify source code; 5300 } until (compiles); 5301 Debug; 5302 if (clueless) 5303 email("Hi, I am having problems..."); 5304 } 5305 Send patch file to the U-Boot email list; 5306 if (reasonable critiques) 5307 Incorporate improvements from email list code review; 5308 else 5309 Defend code as written; 5310 } 5311 5312 return 0; 5313} 5314 5315void no_more_time (int sig) 5316{ 5317 hire_a_guru(); 5318} 5319 5320 5321Coding Standards: 5322----------------- 5323 5324All contributions to U-Boot should conform to the Linux kernel 5325coding style; see the file "Documentation/CodingStyle" and the script 5326"scripts/Lindent" in your Linux kernel source directory. 5327 5328Source files originating from a different project (for example the 5329MTD subsystem) are generally exempt from these guidelines and are not 5330reformatted to ease subsequent migration to newer versions of those 5331sources. 5332 5333Please note that U-Boot is implemented in C (and to some small parts in 5334Assembler); no C++ is used, so please do not use C++ style comments (//) 5335in your code. 5336 5337Please also stick to the following formatting rules: 5338- remove any trailing white space 5339- use TAB characters for indentation and vertical alignment, not spaces 5340- make sure NOT to use DOS '\r\n' line feeds 5341- do not add more than 2 consecutive empty lines to source files 5342- do not add trailing empty lines to source files 5343 5344Submissions which do not conform to the standards may be returned 5345with a request to reformat the changes. 5346 5347 5348Submitting Patches: 5349------------------- 5350 5351Since the number of patches for U-Boot is growing, we need to 5352establish some rules. Submissions which do not conform to these rules 5353may be rejected, even when they contain important and valuable stuff. 5354 5355Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5356 5357Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5358see http://lists.denx.de/mailman/listinfo/u-boot 5359 5360When you send a patch, please include the following information with 5361it: 5362 5363* For bug fixes: a description of the bug and how your patch fixes 5364 this bug. Please try to include a way of demonstrating that the 5365 patch actually fixes something. 5366 5367* For new features: a description of the feature and your 5368 implementation. 5369 5370* A CHANGELOG entry as plaintext (separate from the patch) 5371 5372* For major contributions, add a MAINTAINERS file with your 5373 information and associated file and directory references. 5374 5375* When you add support for a new board, don't forget to add a 5376 maintainer e-mail address to the boards.cfg file, too. 5377 5378* If your patch adds new configuration options, don't forget to 5379 document these in the README file. 5380 5381* The patch itself. If you are using git (which is *strongly* 5382 recommended) you can easily generate the patch using the 5383 "git format-patch". If you then use "git send-email" to send it to 5384 the U-Boot mailing list, you will avoid most of the common problems 5385 with some other mail clients. 5386 5387 If you cannot use git, use "diff -purN OLD NEW". If your version of 5388 diff does not support these options, then get the latest version of 5389 GNU diff. 5390 5391 The current directory when running this command shall be the parent 5392 directory of the U-Boot source tree (i. e. please make sure that 5393 your patch includes sufficient directory information for the 5394 affected files). 5395 5396 We prefer patches as plain text. MIME attachments are discouraged, 5397 and compressed attachments must not be used. 5398 5399* If one logical set of modifications affects or creates several 5400 files, all these changes shall be submitted in a SINGLE patch file. 5401 5402* Changesets that contain different, unrelated modifications shall be 5403 submitted as SEPARATE patches, one patch per changeset. 5404 5405 5406Notes: 5407 5408* Before sending the patch, run the buildman script on your patched 5409 source tree and make sure that no errors or warnings are reported 5410 for any of the boards. 5411 5412* Keep your modifications to the necessary minimum: A patch 5413 containing several unrelated changes or arbitrary reformats will be 5414 returned with a request to re-formatting / split it. 5415 5416* If you modify existing code, make sure that your new code does not 5417 add to the memory footprint of the code ;-) Small is beautiful! 5418 When adding new features, these should compile conditionally only 5419 (using #ifdef), and the resulting code with the new feature 5420 disabled must not need more memory than the old code without your 5421 modification. 5422 5423* Remember that there is a size limit of 100 kB per message on the 5424 u-boot mailing list. Bigger patches will be moderated. If they are 5425 reasonable and not too big, they will be acknowledged. But patches 5426 bigger than the size limit should be avoided. 5427