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- 8xx CPU Options: (if using an MPC8xx CPU) 328 CONFIG_8xx_GCLK_FREQ - CPU clock 329 330- 85xx CPU Options: 331 CONFIG_SYS_PPC64 332 333 Specifies that the core is a 64-bit PowerPC implementation (implements 334 the "64" category of the Power ISA). This is necessary for ePAPR 335 compliance, among other possible reasons. 336 337 CONFIG_SYS_FSL_TBCLK_DIV 338 339 Defines the core time base clock divider ratio compared to the 340 system clock. On most PQ3 devices this is 8, on newer QorIQ 341 devices it can be 16 or 32. The ratio varies from SoC to Soc. 342 343 CONFIG_SYS_FSL_PCIE_COMPAT 344 345 Defines the string to utilize when trying to match PCIe device 346 tree nodes for the given platform. 347 348 CONFIG_SYS_FSL_ERRATUM_A004510 349 350 Enables a workaround for erratum A004510. If set, 351 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 352 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 353 354 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 355 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 356 357 Defines one or two SoC revisions (low 8 bits of SVR) 358 for which the A004510 workaround should be applied. 359 360 The rest of SVR is either not relevant to the decision 361 of whether the erratum is present (e.g. p2040 versus 362 p2041) or is implied by the build target, which controls 363 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 364 365 See Freescale App Note 4493 for more information about 366 this erratum. 367 368 CONFIG_A003399_NOR_WORKAROUND 369 Enables a workaround for IFC erratum A003399. It is only 370 required during NOR boot. 371 372 CONFIG_A008044_WORKAROUND 373 Enables a workaround for T1040/T1042 erratum A008044. It is only 374 required during NAND boot and valid for Rev 1.0 SoC revision 375 376 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 377 378 This is the value to write into CCSR offset 0x18600 379 according to the A004510 workaround. 380 381 CONFIG_SYS_FSL_DSP_DDR_ADDR 382 This value denotes start offset of DDR memory which is 383 connected exclusively to the DSP cores. 384 385 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 386 This value denotes start offset of M2 memory 387 which is directly connected to the DSP core. 388 389 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 390 This value denotes start offset of M3 memory which is directly 391 connected to the DSP core. 392 393 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 394 This value denotes start offset of DSP CCSR space. 395 396 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 397 Single Source Clock is clocking mode present in some of FSL SoC's. 398 In this mode, a single differential clock is used to supply 399 clocks to the sysclock, ddrclock and usbclock. 400 401 CONFIG_SYS_CPC_REINIT_F 402 This CONFIG is defined when the CPC is configured as SRAM at the 403 time of U-Boot entry and is required to be re-initialized. 404 405 CONFIG_DEEP_SLEEP 406 Indicates this SoC supports deep sleep feature. If deep sleep is 407 supported, core will start to execute uboot when wakes up. 408 409- Generic CPU options: 410 CONFIG_SYS_GENERIC_GLOBAL_DATA 411 Defines global data is initialized in generic board board_init_f(). 412 If this macro is defined, global data is created and cleared in 413 generic board board_init_f(). Without this macro, architecture/board 414 should initialize global data before calling board_init_f(). 415 416 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 417 418 Defines the endianess of the CPU. Implementation of those 419 values is arch specific. 420 421 CONFIG_SYS_FSL_DDR 422 Freescale DDR driver in use. This type of DDR controller is 423 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 424 SoCs. 425 426 CONFIG_SYS_FSL_DDR_ADDR 427 Freescale DDR memory-mapped register base. 428 429 CONFIG_SYS_FSL_DDR_EMU 430 Specify emulator support for DDR. Some DDR features such as 431 deskew training are not available. 432 433 CONFIG_SYS_FSL_DDRC_GEN1 434 Freescale DDR1 controller. 435 436 CONFIG_SYS_FSL_DDRC_GEN2 437 Freescale DDR2 controller. 438 439 CONFIG_SYS_FSL_DDRC_GEN3 440 Freescale DDR3 controller. 441 442 CONFIG_SYS_FSL_DDRC_GEN4 443 Freescale DDR4 controller. 444 445 CONFIG_SYS_FSL_DDRC_ARM_GEN3 446 Freescale DDR3 controller for ARM-based SoCs. 447 448 CONFIG_SYS_FSL_DDR1 449 Board config to use DDR1. It can be enabled for SoCs with 450 Freescale DDR1 or DDR2 controllers, depending on the board 451 implemetation. 452 453 CONFIG_SYS_FSL_DDR2 454 Board config to use DDR2. It can be enabled for SoCs with 455 Freescale DDR2 or DDR3 controllers, depending on the board 456 implementation. 457 458 CONFIG_SYS_FSL_DDR3 459 Board config to use DDR3. It can be enabled for SoCs with 460 Freescale DDR3 or DDR3L controllers. 461 462 CONFIG_SYS_FSL_DDR3L 463 Board config to use DDR3L. It can be enabled for SoCs with 464 DDR3L controllers. 465 466 CONFIG_SYS_FSL_DDR4 467 Board config to use DDR4. It can be enabled for SoCs with 468 DDR4 controllers. 469 470 CONFIG_SYS_FSL_IFC_BE 471 Defines the IFC controller register space as Big Endian 472 473 CONFIG_SYS_FSL_IFC_LE 474 Defines the IFC controller register space as Little Endian 475 476 CONFIG_SYS_FSL_IFC_CLK_DIV 477 Defines divider of platform clock(clock input to IFC controller). 478 479 CONFIG_SYS_FSL_LBC_CLK_DIV 480 Defines divider of platform clock(clock input to eLBC controller). 481 482 CONFIG_SYS_FSL_PBL_PBI 483 It enables addition of RCW (Power on reset configuration) in built image. 484 Please refer doc/README.pblimage for more details 485 486 CONFIG_SYS_FSL_PBL_RCW 487 It adds PBI(pre-boot instructions) commands in u-boot build image. 488 PBI commands can be used to configure SoC before it starts the execution. 489 Please refer doc/README.pblimage for more details 490 491 CONFIG_SPL_FSL_PBL 492 It adds a target to create boot binary having SPL binary in PBI format 493 concatenated with u-boot binary. 494 495 CONFIG_SYS_FSL_DDR_BE 496 Defines the DDR controller register space as Big Endian 497 498 CONFIG_SYS_FSL_DDR_LE 499 Defines the DDR controller register space as Little Endian 500 501 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 502 Physical address from the view of DDR controllers. It is the 503 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 504 it could be different for ARM SoCs. 505 506 CONFIG_SYS_FSL_DDR_INTLV_256B 507 DDR controller interleaving on 256-byte. This is a special 508 interleaving mode, handled by Dickens for Freescale layerscape 509 SoCs with ARM core. 510 511 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 512 Number of controllers used as main memory. 513 514 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 515 Number of controllers used for other than main memory. 516 517 CONFIG_SYS_FSL_HAS_DP_DDR 518 Defines the SoC has DP-DDR used for DPAA. 519 520 CONFIG_SYS_FSL_SEC_BE 521 Defines the SEC controller register space as Big Endian 522 523 CONFIG_SYS_FSL_SEC_LE 524 Defines the SEC controller register space as Little Endian 525 526- MIPS CPU options: 527 CONFIG_SYS_INIT_SP_OFFSET 528 529 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 530 pointer. This is needed for the temporary stack before 531 relocation. 532 533 CONFIG_SYS_MIPS_CACHE_MODE 534 535 Cache operation mode for the MIPS CPU. 536 See also arch/mips/include/asm/mipsregs.h. 537 Possible values are: 538 CONF_CM_CACHABLE_NO_WA 539 CONF_CM_CACHABLE_WA 540 CONF_CM_UNCACHED 541 CONF_CM_CACHABLE_NONCOHERENT 542 CONF_CM_CACHABLE_CE 543 CONF_CM_CACHABLE_COW 544 CONF_CM_CACHABLE_CUW 545 CONF_CM_CACHABLE_ACCELERATED 546 547 CONFIG_SYS_XWAY_EBU_BOOTCFG 548 549 Special option for Lantiq XWAY SoCs for booting from NOR flash. 550 See also arch/mips/cpu/mips32/start.S. 551 552 CONFIG_XWAY_SWAP_BYTES 553 554 Enable compilation of tools/xway-swap-bytes needed for Lantiq 555 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 556 be swapped if a flash programmer is used. 557 558- ARM options: 559 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 560 561 Select high exception vectors of the ARM core, e.g., do not 562 clear the V bit of the c1 register of CP15. 563 564 COUNTER_FREQUENCY 565 Generic timer clock source frequency. 566 567 COUNTER_FREQUENCY_REAL 568 Generic timer clock source frequency if the real clock is 569 different from COUNTER_FREQUENCY, and can only be determined 570 at run time. 571 572- Tegra SoC options: 573 CONFIG_TEGRA_SUPPORT_NON_SECURE 574 575 Support executing U-Boot in non-secure (NS) mode. Certain 576 impossible actions will be skipped if the CPU is in NS mode, 577 such as ARM architectural timer initialization. 578 579- Linux Kernel Interface: 580 CONFIG_CLOCKS_IN_MHZ 581 582 U-Boot stores all clock information in Hz 583 internally. For binary compatibility with older Linux 584 kernels (which expect the clocks passed in the 585 bd_info data to be in MHz) the environment variable 586 "clocks_in_mhz" can be defined so that U-Boot 587 converts clock data to MHZ before passing it to the 588 Linux kernel. 589 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 590 "clocks_in_mhz=1" is automatically included in the 591 default environment. 592 593 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 594 595 When transferring memsize parameter to Linux, some versions 596 expect it to be in bytes, others in MB. 597 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 598 599 CONFIG_OF_LIBFDT 600 601 New kernel versions are expecting firmware settings to be 602 passed using flattened device trees (based on open firmware 603 concepts). 604 605 CONFIG_OF_LIBFDT 606 * New libfdt-based support 607 * Adds the "fdt" command 608 * The bootm command automatically updates the fdt 609 610 OF_TBCLK - The timebase frequency. 611 OF_STDOUT_PATH - The path to the console device 612 613 boards with QUICC Engines require OF_QE to set UCC MAC 614 addresses 615 616 CONFIG_OF_BOARD_SETUP 617 618 Board code has addition modification that it wants to make 619 to the flat device tree before handing it off to the kernel 620 621 CONFIG_OF_SYSTEM_SETUP 622 623 Other code has addition modification that it wants to make 624 to the flat device tree before handing it off to the kernel. 625 This causes ft_system_setup() to be called before booting 626 the kernel. 627 628 CONFIG_OF_IDE_FIXUP 629 630 U-Boot can detect if an IDE device is present or not. 631 If not, and this new config option is activated, U-Boot 632 removes the ATA node from the DTS before booting Linux, 633 so the Linux IDE driver does not probe the device and 634 crash. This is needed for buggy hardware (uc101) where 635 no pull down resistor is connected to the signal IDE5V_DD7. 636 637 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 638 639 This setting is mandatory for all boards that have only one 640 machine type and must be used to specify the machine type 641 number as it appears in the ARM machine registry 642 (see http://www.arm.linux.org.uk/developer/machines/). 643 Only boards that have multiple machine types supported 644 in a single configuration file and the machine type is 645 runtime discoverable, do not have to use this setting. 646 647- vxWorks boot parameters: 648 649 bootvx constructs a valid bootline using the following 650 environments variables: bootdev, bootfile, ipaddr, netmask, 651 serverip, gatewayip, hostname, othbootargs. 652 It loads the vxWorks image pointed bootfile. 653 654 Note: If a "bootargs" environment is defined, it will overwride 655 the defaults discussed just above. 656 657- Cache Configuration: 658 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 659 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 660 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 661 662- Cache Configuration for ARM: 663 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 664 controller 665 CONFIG_SYS_PL310_BASE - Physical base address of PL310 666 controller register space 667 668- Serial Ports: 669 CONFIG_PL010_SERIAL 670 671 Define this if you want support for Amba PrimeCell PL010 UARTs. 672 673 CONFIG_PL011_SERIAL 674 675 Define this if you want support for Amba PrimeCell PL011 UARTs. 676 677 CONFIG_PL011_CLOCK 678 679 If you have Amba PrimeCell PL011 UARTs, set this variable to 680 the clock speed of the UARTs. 681 682 CONFIG_PL01x_PORTS 683 684 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 685 define this to a list of base addresses for each (supported) 686 port. See e.g. include/configs/versatile.h 687 688 CONFIG_SERIAL_HW_FLOW_CONTROL 689 690 Define this variable to enable hw flow control in serial driver. 691 Current user of this option is drivers/serial/nsl16550.c driver 692 693- Console Interface: 694 Depending on board, define exactly one serial port 695 (CONFIG_8xx_CONS_SMC1 or CONFIG_8xx_CONS_SMC2), 696 or switch off the serial console by defining 697 CONFIG_8xx_CONS_NONE 698 699 Note: if CONFIG_8xx_CONS_NONE is defined, the serial 700 port routines must be defined elsewhere 701 (i.e. serial_init(), serial_getc(), ...) 702 703- Console Baudrate: 704 CONFIG_BAUDRATE - in bps 705 Select one of the baudrates listed in 706 CONFIG_SYS_BAUDRATE_TABLE, see below. 707 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale 708 709- Console Rx buffer length 710 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define 711 the maximum receive buffer length for the SMC. 712 This option is actual only for 8xx possible. 713 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE 714 must be defined, to setup the maximum idle timeout for 715 the SMC. 716 717- Autoboot Command: 718 CONFIG_BOOTCOMMAND 719 Only needed when CONFIG_BOOTDELAY is enabled; 720 define a command string that is automatically executed 721 when no character is read on the console interface 722 within "Boot Delay" after reset. 723 724 CONFIG_BOOTARGS 725 This can be used to pass arguments to the bootm 726 command. The value of CONFIG_BOOTARGS goes into the 727 environment value "bootargs". 728 729 CONFIG_RAMBOOT and CONFIG_NFSBOOT 730 The value of these goes into the environment as 731 "ramboot" and "nfsboot" respectively, and can be used 732 as a convenience, when switching between booting from 733 RAM and NFS. 734 735- Bootcount: 736 CONFIG_BOOTCOUNT_LIMIT 737 Implements a mechanism for detecting a repeating reboot 738 cycle, see: 739 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 740 741 CONFIG_BOOTCOUNT_ENV 742 If no softreset save registers are found on the hardware 743 "bootcount" is stored in the environment. To prevent a 744 saveenv on all reboots, the environment variable 745 "upgrade_available" is used. If "upgrade_available" is 746 0, "bootcount" is always 0, if "upgrade_available" is 747 1 "bootcount" is incremented in the environment. 748 So the Userspace Applikation must set the "upgrade_available" 749 and "bootcount" variable to 0, if a boot was successfully. 750 751- Pre-Boot Commands: 752 CONFIG_PREBOOT 753 754 When this option is #defined, the existence of the 755 environment variable "preboot" will be checked 756 immediately before starting the CONFIG_BOOTDELAY 757 countdown and/or running the auto-boot command resp. 758 entering interactive mode. 759 760 This feature is especially useful when "preboot" is 761 automatically generated or modified. For an example 762 see the LWMON board specific code: here "preboot" is 763 modified when the user holds down a certain 764 combination of keys on the (special) keyboard when 765 booting the systems 766 767- Serial Download Echo Mode: 768 CONFIG_LOADS_ECHO 769 If defined to 1, all characters received during a 770 serial download (using the "loads" command) are 771 echoed back. This might be needed by some terminal 772 emulations (like "cu"), but may as well just take 773 time on others. This setting #define's the initial 774 value of the "loads_echo" environment variable. 775 776- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 777 CONFIG_KGDB_BAUDRATE 778 Select one of the baudrates listed in 779 CONFIG_SYS_BAUDRATE_TABLE, see below. 780 781- Monitor Functions: 782 Monitor commands can be included or excluded 783 from the build by using the #include files 784 <config_cmd_all.h> and #undef'ing unwanted 785 commands, or adding #define's for wanted commands. 786 787 The default command configuration includes all commands 788 except those marked below with a "*". 789 790 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 791 CONFIG_CMD_ASKENV * ask for env variable 792 CONFIG_CMD_BDI bdinfo 793 CONFIG_CMD_BOOTD bootd 794 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 795 CONFIG_CMD_CACHE * icache, dcache 796 CONFIG_CMD_CONSOLE coninfo 797 CONFIG_CMD_DHCP * DHCP support 798 CONFIG_CMD_DIAG * Diagnostics 799 CONFIG_CMD_ECHO echo arguments 800 CONFIG_CMD_EDITENV edit env variable 801 CONFIG_CMD_ELF * bootelf, bootvx 802 CONFIG_CMD_ENV_EXISTS * check existence of env variable 803 CONFIG_CMD_EXPORTENV * export the environment 804 CONFIG_CMD_EXT2 * ext2 command support 805 CONFIG_CMD_EXT4 * ext4 command support 806 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 807 that work for multiple fs types 808 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 809 CONFIG_CMD_SAVEENV saveenv 810 CONFIG_CMD_FLASH flinfo, erase, protect 811 CONFIG_CMD_FPGA FPGA device initialization support 812 CONFIG_CMD_GO * the 'go' command (exec code) 813 CONFIG_CMD_GREPENV * search environment 814 CONFIG_CMD_I2C * I2C serial bus support 815 CONFIG_CMD_IMI iminfo 816 CONFIG_CMD_IMLS List all images found in NOR flash 817 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 818 CONFIG_CMD_IMPORTENV * import an environment 819 CONFIG_CMD_INI * import data from an ini file into the env 820 CONFIG_CMD_ITEST Integer/string test of 2 values 821 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 822 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 823 (169.254.*.*) 824 CONFIG_CMD_LOADB loadb 825 CONFIG_CMD_LOADS loads 826 CONFIG_CMD_MD5SUM * print md5 message digest 827 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 828 CONFIG_CMD_MEMINFO * Display detailed memory information 829 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 830 loop, loopw 831 CONFIG_CMD_MEMTEST * mtest 832 CONFIG_CMD_MISC Misc functions like sleep etc 833 CONFIG_CMD_MMC * MMC memory mapped support 834 CONFIG_CMD_MII * MII utility commands 835 CONFIG_CMD_MTDPARTS * MTD partition support 836 CONFIG_CMD_NAND * NAND support 837 CONFIG_CMD_NET bootp, tftpboot, rarpboot 838 CONFIG_CMD_NFS NFS support 839 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 840 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 841 CONFIG_CMD_PCI * pciinfo 842 CONFIG_CMD_PCMCIA * PCMCIA support 843 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 844 host 845 CONFIG_CMD_PORTIO * Port I/O 846 CONFIG_CMD_READ * Read raw data from partition 847 CONFIG_CMD_REGINFO * Register dump 848 CONFIG_CMD_RUN run command in env variable 849 CONFIG_CMD_SANDBOX * sb command to access sandbox features 850 CONFIG_CMD_SAVES * save S record dump 851 CONFIG_SCSI * SCSI Support 852 CONFIG_CMD_SDRAM * print SDRAM configuration information 853 (requires CONFIG_CMD_I2C) 854 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 855 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 856 CONFIG_CMD_SOURCE "source" command Support 857 CONFIG_CMD_SPI * SPI serial bus support 858 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 859 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 860 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 861 CONFIG_CMD_TIMER * access to the system tick timer 862 CONFIG_CMD_USB * USB support 863 CONFIG_CMD_CDP * Cisco Discover Protocol support 864 CONFIG_CMD_MFSL * Microblaze FSL support 865 CONFIG_CMD_XIMG Load part of Multi Image 866 CONFIG_CMD_UUID * Generate random UUID or GUID string 867 868 EXAMPLE: If you want all functions except of network 869 support you can write: 870 871 #include "config_cmd_all.h" 872 #undef CONFIG_CMD_NET 873 874 Other Commands: 875 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 876 877 Note: Don't enable the "icache" and "dcache" commands 878 (configuration option CONFIG_CMD_CACHE) unless you know 879 what you (and your U-Boot users) are doing. Data 880 cache cannot be enabled on systems like the 881 8xx (where accesses to the IMMR region must be 882 uncached), and it cannot be disabled on all other 883 systems where we (mis-) use the data cache to hold an 884 initial stack and some data. 885 886 887 XXX - this list needs to get updated! 888 889- Removal of commands 890 If no commands are needed to boot, you can disable 891 CONFIG_CMDLINE to remove them. In this case, the command line 892 will not be available, and when U-Boot wants to execute the 893 boot command (on start-up) it will call board_run_command() 894 instead. This can reduce image size significantly for very 895 simple boot procedures. 896 897- Regular expression support: 898 CONFIG_REGEX 899 If this variable is defined, U-Boot is linked against 900 the SLRE (Super Light Regular Expression) library, 901 which adds regex support to some commands, as for 902 example "env grep" and "setexpr". 903 904- Device tree: 905 CONFIG_OF_CONTROL 906 If this variable is defined, U-Boot will use a device tree 907 to configure its devices, instead of relying on statically 908 compiled #defines in the board file. This option is 909 experimental and only available on a few boards. The device 910 tree is available in the global data as gd->fdt_blob. 911 912 U-Boot needs to get its device tree from somewhere. This can 913 be done using one of the three options below: 914 915 CONFIG_OF_EMBED 916 If this variable is defined, U-Boot will embed a device tree 917 binary in its image. This device tree file should be in the 918 board directory and called <soc>-<board>.dts. The binary file 919 is then picked up in board_init_f() and made available through 920 the global data structure as gd->blob. 921 922 CONFIG_OF_SEPARATE 923 If this variable is defined, U-Boot will build a device tree 924 binary. It will be called u-boot.dtb. Architecture-specific 925 code will locate it at run-time. Generally this works by: 926 927 cat u-boot.bin u-boot.dtb >image.bin 928 929 and in fact, U-Boot does this for you, creating a file called 930 u-boot-dtb.bin which is useful in the common case. You can 931 still use the individual files if you need something more 932 exotic. 933 934 CONFIG_OF_BOARD 935 If this variable is defined, U-Boot will use the device tree 936 provided by the board at runtime instead of embedding one with 937 the image. Only boards defining board_fdt_blob_setup() support 938 this option (see include/fdtdec.h file). 939 940- Watchdog: 941 CONFIG_WATCHDOG 942 If this variable is defined, it enables watchdog 943 support for the SoC. There must be support in the SoC 944 specific code for a watchdog. For the 8xx 945 CPUs, the SIU Watchdog feature is enabled in the SYPCR 946 register. When supported for a specific SoC is 947 available, then no further board specific code should 948 be needed to use it. 949 950 CONFIG_HW_WATCHDOG 951 When using a watchdog circuitry external to the used 952 SoC, then define this variable and provide board 953 specific code for the "hw_watchdog_reset" function. 954 955 CONFIG_AT91_HW_WDT_TIMEOUT 956 specify the timeout in seconds. default 2 seconds. 957 958- U-Boot Version: 959 CONFIG_VERSION_VARIABLE 960 If this variable is defined, an environment variable 961 named "ver" is created by U-Boot showing the U-Boot 962 version as printed by the "version" command. 963 Any change to this variable will be reverted at the 964 next reset. 965 966- Real-Time Clock: 967 968 When CONFIG_CMD_DATE is selected, the type of the RTC 969 has to be selected, too. Define exactly one of the 970 following options: 971 972 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 973 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 974 CONFIG_RTC_MC146818 - use MC146818 RTC 975 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 976 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 977 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 978 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 979 CONFIG_RTC_DS164x - use Dallas DS164x RTC 980 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 981 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 982 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 983 CONFIG_SYS_RV3029_TCR - enable trickle charger on 984 RV3029 RTC. 985 986 Note that if the RTC uses I2C, then the I2C interface 987 must also be configured. See I2C Support, below. 988 989- GPIO Support: 990 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 991 992 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 993 chip-ngpio pairs that tell the PCA953X driver the number of 994 pins supported by a particular chip. 995 996 Note that if the GPIO device uses I2C, then the I2C interface 997 must also be configured. See I2C Support, below. 998 999- I/O tracing: 1000 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 1001 accesses and can checksum them or write a list of them out 1002 to memory. See the 'iotrace' command for details. This is 1003 useful for testing device drivers since it can confirm that 1004 the driver behaves the same way before and after a code 1005 change. Currently this is supported on sandbox and arm. To 1006 add support for your architecture, add '#include <iotrace.h>' 1007 to the bottom of arch/<arch>/include/asm/io.h and test. 1008 1009 Example output from the 'iotrace stats' command is below. 1010 Note that if the trace buffer is exhausted, the checksum will 1011 still continue to operate. 1012 1013 iotrace is enabled 1014 Start: 10000000 (buffer start address) 1015 Size: 00010000 (buffer size) 1016 Offset: 00000120 (current buffer offset) 1017 Output: 10000120 (start + offset) 1018 Count: 00000018 (number of trace records) 1019 CRC32: 9526fb66 (CRC32 of all trace records) 1020 1021- Timestamp Support: 1022 1023 When CONFIG_TIMESTAMP is selected, the timestamp 1024 (date and time) of an image is printed by image 1025 commands like bootm or iminfo. This option is 1026 automatically enabled when you select CONFIG_CMD_DATE . 1027 1028- Partition Labels (disklabels) Supported: 1029 Zero or more of the following: 1030 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1031 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1032 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1033 bootloader. Note 2TB partition limit; see 1034 disk/part_efi.c 1035 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1036 1037 If IDE or SCSI support is enabled (CONFIG_IDE or 1038 CONFIG_SCSI) you must configure support for at 1039 least one non-MTD partition type as well. 1040 1041- IDE Reset method: 1042 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1043 board configurations files but used nowhere! 1044 1045 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1046 be performed by calling the function 1047 ide_set_reset(int reset) 1048 which has to be defined in a board specific file 1049 1050- ATAPI Support: 1051 CONFIG_ATAPI 1052 1053 Set this to enable ATAPI support. 1054 1055- LBA48 Support 1056 CONFIG_LBA48 1057 1058 Set this to enable support for disks larger than 137GB 1059 Also look at CONFIG_SYS_64BIT_LBA. 1060 Whithout these , LBA48 support uses 32bit variables and will 'only' 1061 support disks up to 2.1TB. 1062 1063 CONFIG_SYS_64BIT_LBA: 1064 When enabled, makes the IDE subsystem use 64bit sector addresses. 1065 Default is 32bit. 1066 1067- SCSI Support: 1068 At the moment only there is only support for the 1069 SYM53C8XX SCSI controller; define 1070 CONFIG_SCSI_SYM53C8XX to enable it. 1071 1072 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1073 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1074 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1075 maximum numbers of LUNs, SCSI ID's and target 1076 devices. 1077 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1078 1079 The environment variable 'scsidevs' is set to the number of 1080 SCSI devices found during the last scan. 1081 1082- NETWORK Support (PCI): 1083 CONFIG_E1000 1084 Support for Intel 8254x/8257x gigabit chips. 1085 1086 CONFIG_E1000_SPI 1087 Utility code for direct access to the SPI bus on Intel 8257x. 1088 This does not do anything useful unless you set at least one 1089 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1090 1091 CONFIG_E1000_SPI_GENERIC 1092 Allow generic access to the SPI bus on the Intel 8257x, for 1093 example with the "sspi" command. 1094 1095 CONFIG_CMD_E1000 1096 Management command for E1000 devices. When used on devices 1097 with SPI support you can reprogram the EEPROM from U-Boot. 1098 1099 CONFIG_EEPRO100 1100 Support for Intel 82557/82559/82559ER chips. 1101 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1102 write routine for first time initialisation. 1103 1104 CONFIG_TULIP 1105 Support for Digital 2114x chips. 1106 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1107 modem chip initialisation (KS8761/QS6611). 1108 1109 CONFIG_NATSEMI 1110 Support for National dp83815 chips. 1111 1112 CONFIG_NS8382X 1113 Support for National dp8382[01] gigabit chips. 1114 1115- NETWORK Support (other): 1116 1117 CONFIG_DRIVER_AT91EMAC 1118 Support for AT91RM9200 EMAC. 1119 1120 CONFIG_RMII 1121 Define this to use reduced MII inteface 1122 1123 CONFIG_DRIVER_AT91EMAC_QUIET 1124 If this defined, the driver is quiet. 1125 The driver doen't show link status messages. 1126 1127 CONFIG_CALXEDA_XGMAC 1128 Support for the Calxeda XGMAC device 1129 1130 CONFIG_LAN91C96 1131 Support for SMSC's LAN91C96 chips. 1132 1133 CONFIG_LAN91C96_USE_32_BIT 1134 Define this to enable 32 bit addressing 1135 1136 CONFIG_SMC91111 1137 Support for SMSC's LAN91C111 chip 1138 1139 CONFIG_SMC91111_BASE 1140 Define this to hold the physical address 1141 of the device (I/O space) 1142 1143 CONFIG_SMC_USE_32_BIT 1144 Define this if data bus is 32 bits 1145 1146 CONFIG_SMC_USE_IOFUNCS 1147 Define this to use i/o functions instead of macros 1148 (some hardware wont work with macros) 1149 1150 CONFIG_DRIVER_TI_EMAC 1151 Support for davinci emac 1152 1153 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1154 Define this if you have more then 3 PHYs. 1155 1156 CONFIG_FTGMAC100 1157 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1158 1159 CONFIG_FTGMAC100_EGIGA 1160 Define this to use GE link update with gigabit PHY. 1161 Define this if FTGMAC100 is connected to gigabit PHY. 1162 If your system has 10/100 PHY only, it might not occur 1163 wrong behavior. Because PHY usually return timeout or 1164 useless data when polling gigabit status and gigabit 1165 control registers. This behavior won't affect the 1166 correctnessof 10/100 link speed update. 1167 1168 CONFIG_SMC911X 1169 Support for SMSC's LAN911x and LAN921x chips 1170 1171 CONFIG_SMC911X_BASE 1172 Define this to hold the physical address 1173 of the device (I/O space) 1174 1175 CONFIG_SMC911X_32_BIT 1176 Define this if data bus is 32 bits 1177 1178 CONFIG_SMC911X_16_BIT 1179 Define this if data bus is 16 bits. If your processor 1180 automatically converts one 32 bit word to two 16 bit 1181 words you may also try CONFIG_SMC911X_32_BIT. 1182 1183 CONFIG_SH_ETHER 1184 Support for Renesas on-chip Ethernet controller 1185 1186 CONFIG_SH_ETHER_USE_PORT 1187 Define the number of ports to be used 1188 1189 CONFIG_SH_ETHER_PHY_ADDR 1190 Define the ETH PHY's address 1191 1192 CONFIG_SH_ETHER_CACHE_WRITEBACK 1193 If this option is set, the driver enables cache flush. 1194 1195- PWM Support: 1196 CONFIG_PWM_IMX 1197 Support for PWM module on the imx6. 1198 1199- TPM Support: 1200 CONFIG_TPM 1201 Support TPM devices. 1202 1203 CONFIG_TPM_TIS_INFINEON 1204 Support for Infineon i2c bus TPM devices. Only one device 1205 per system is supported at this time. 1206 1207 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1208 Define the burst count bytes upper limit 1209 1210 CONFIG_TPM_ST33ZP24 1211 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1212 1213 CONFIG_TPM_ST33ZP24_I2C 1214 Support for STMicroelectronics ST33ZP24 I2C devices. 1215 Requires TPM_ST33ZP24 and I2C. 1216 1217 CONFIG_TPM_ST33ZP24_SPI 1218 Support for STMicroelectronics ST33ZP24 SPI devices. 1219 Requires TPM_ST33ZP24 and SPI. 1220 1221 CONFIG_TPM_ATMEL_TWI 1222 Support for Atmel TWI TPM device. Requires I2C support. 1223 1224 CONFIG_TPM_TIS_LPC 1225 Support for generic parallel port TPM devices. Only one device 1226 per system is supported at this time. 1227 1228 CONFIG_TPM_TIS_BASE_ADDRESS 1229 Base address where the generic TPM device is mapped 1230 to. Contemporary x86 systems usually map it at 1231 0xfed40000. 1232 1233 CONFIG_CMD_TPM 1234 Add tpm monitor functions. 1235 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1236 provides monitor access to authorized functions. 1237 1238 CONFIG_TPM 1239 Define this to enable the TPM support library which provides 1240 functional interfaces to some TPM commands. 1241 Requires support for a TPM device. 1242 1243 CONFIG_TPM_AUTH_SESSIONS 1244 Define this to enable authorized functions in the TPM library. 1245 Requires CONFIG_TPM and CONFIG_SHA1. 1246 1247- USB Support: 1248 At the moment only the UHCI host controller is 1249 supported (PIP405, MIP405); define 1250 CONFIG_USB_UHCI to enable it. 1251 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1252 and define CONFIG_USB_STORAGE to enable the USB 1253 storage devices. 1254 Note: 1255 Supported are USB Keyboards and USB Floppy drives 1256 (TEAC FD-05PUB). 1257 1258 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1259 txfilltuning field in the EHCI controller on reset. 1260 1261 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1262 HW module registers. 1263 1264- USB Device: 1265 Define the below if you wish to use the USB console. 1266 Once firmware is rebuilt from a serial console issue the 1267 command "setenv stdin usbtty; setenv stdout usbtty" and 1268 attach your USB cable. The Unix command "dmesg" should print 1269 it has found a new device. The environment variable usbtty 1270 can be set to gserial or cdc_acm to enable your device to 1271 appear to a USB host as a Linux gserial device or a 1272 Common Device Class Abstract Control Model serial device. 1273 If you select usbtty = gserial you should be able to enumerate 1274 a Linux host by 1275 # modprobe usbserial vendor=0xVendorID product=0xProductID 1276 else if using cdc_acm, simply setting the environment 1277 variable usbtty to be cdc_acm should suffice. The following 1278 might be defined in YourBoardName.h 1279 1280 CONFIG_USB_DEVICE 1281 Define this to build a UDC device 1282 1283 CONFIG_USB_TTY 1284 Define this to have a tty type of device available to 1285 talk to the UDC device 1286 1287 CONFIG_USBD_HS 1288 Define this to enable the high speed support for usb 1289 device and usbtty. If this feature is enabled, a routine 1290 int is_usbd_high_speed(void) 1291 also needs to be defined by the driver to dynamically poll 1292 whether the enumeration has succeded at high speed or full 1293 speed. 1294 1295 CONFIG_SYS_CONSOLE_IS_IN_ENV 1296 Define this if you want stdin, stdout &/or stderr to 1297 be set to usbtty. 1298 1299 If you have a USB-IF assigned VendorID then you may wish to 1300 define your own vendor specific values either in BoardName.h 1301 or directly in usbd_vendor_info.h. If you don't define 1302 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1303 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1304 should pretend to be a Linux device to it's target host. 1305 1306 CONFIG_USBD_MANUFACTURER 1307 Define this string as the name of your company for 1308 - CONFIG_USBD_MANUFACTURER "my company" 1309 1310 CONFIG_USBD_PRODUCT_NAME 1311 Define this string as the name of your product 1312 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1313 1314 CONFIG_USBD_VENDORID 1315 Define this as your assigned Vendor ID from the USB 1316 Implementors Forum. This *must* be a genuine Vendor ID 1317 to avoid polluting the USB namespace. 1318 - CONFIG_USBD_VENDORID 0xFFFF 1319 1320 CONFIG_USBD_PRODUCTID 1321 Define this as the unique Product ID 1322 for your device 1323 - CONFIG_USBD_PRODUCTID 0xFFFF 1324 1325- ULPI Layer Support: 1326 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1327 the generic ULPI layer. The generic layer accesses the ULPI PHY 1328 via the platform viewport, so you need both the genric layer and 1329 the viewport enabled. Currently only Chipidea/ARC based 1330 viewport is supported. 1331 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1332 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1333 If your ULPI phy needs a different reference clock than the 1334 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1335 the appropriate value in Hz. 1336 1337- MMC Support: 1338 The MMC controller on the Intel PXA is supported. To 1339 enable this define CONFIG_MMC. The MMC can be 1340 accessed from the boot prompt by mapping the device 1341 to physical memory similar to flash. Command line is 1342 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1343 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1344 1345 CONFIG_SH_MMCIF 1346 Support for Renesas on-chip MMCIF controller 1347 1348 CONFIG_SH_MMCIF_ADDR 1349 Define the base address of MMCIF registers 1350 1351 CONFIG_SH_MMCIF_CLK 1352 Define the clock frequency for MMCIF 1353 1354 CONFIG_SUPPORT_EMMC_BOOT 1355 Enable some additional features of the eMMC boot partitions. 1356 1357 CONFIG_SUPPORT_EMMC_RPMB 1358 Enable the commands for reading, writing and programming the 1359 key for the Replay Protection Memory Block partition in eMMC. 1360 1361- USB Device Firmware Update (DFU) class support: 1362 CONFIG_USB_FUNCTION_DFU 1363 This enables the USB portion of the DFU USB class 1364 1365 CONFIG_CMD_DFU 1366 This enables the command "dfu" which is used to have 1367 U-Boot create a DFU class device via USB. This command 1368 requires that the "dfu_alt_info" environment variable be 1369 set and define the alt settings to expose to the host. 1370 1371 CONFIG_DFU_MMC 1372 This enables support for exposing (e)MMC devices via DFU. 1373 1374 CONFIG_DFU_NAND 1375 This enables support for exposing NAND devices via DFU. 1376 1377 CONFIG_DFU_RAM 1378 This enables support for exposing RAM via DFU. 1379 Note: DFU spec refer to non-volatile memory usage, but 1380 allow usages beyond the scope of spec - here RAM usage, 1381 one that would help mostly the developer. 1382 1383 CONFIG_SYS_DFU_DATA_BUF_SIZE 1384 Dfu transfer uses a buffer before writing data to the 1385 raw storage device. Make the size (in bytes) of this buffer 1386 configurable. The size of this buffer is also configurable 1387 through the "dfu_bufsiz" environment variable. 1388 1389 CONFIG_SYS_DFU_MAX_FILE_SIZE 1390 When updating files rather than the raw storage device, 1391 we use a static buffer to copy the file into and then write 1392 the buffer once we've been given the whole file. Define 1393 this to the maximum filesize (in bytes) for the buffer. 1394 Default is 4 MiB if undefined. 1395 1396 DFU_DEFAULT_POLL_TIMEOUT 1397 Poll timeout [ms], is the timeout a device can send to the 1398 host. The host must wait for this timeout before sending 1399 a subsequent DFU_GET_STATUS request to the device. 1400 1401 DFU_MANIFEST_POLL_TIMEOUT 1402 Poll timeout [ms], which the device sends to the host when 1403 entering dfuMANIFEST state. Host waits this timeout, before 1404 sending again an USB request to the device. 1405 1406- USB Device Android Fastboot support: 1407 CONFIG_USB_FUNCTION_FASTBOOT 1408 This enables the USB part of the fastboot gadget 1409 1410 CONFIG_CMD_FASTBOOT 1411 This enables the command "fastboot" which enables the Android 1412 fastboot mode for the platform's USB device. Fastboot is a USB 1413 protocol for downloading images, flashing and device control 1414 used on Android devices. 1415 See doc/README.android-fastboot for more information. 1416 1417 CONFIG_ANDROID_BOOT_IMAGE 1418 This enables support for booting images which use the Android 1419 image format header. 1420 1421 CONFIG_FASTBOOT_BUF_ADDR 1422 The fastboot protocol requires a large memory buffer for 1423 downloads. Define this to the starting RAM address to use for 1424 downloaded images. 1425 1426 CONFIG_FASTBOOT_BUF_SIZE 1427 The fastboot protocol requires a large memory buffer for 1428 downloads. This buffer should be as large as possible for a 1429 platform. Define this to the size available RAM for fastboot. 1430 1431 CONFIG_FASTBOOT_FLASH 1432 The fastboot protocol includes a "flash" command for writing 1433 the downloaded image to a non-volatile storage device. Define 1434 this to enable the "fastboot flash" command. 1435 1436 CONFIG_FASTBOOT_FLASH_MMC_DEV 1437 The fastboot "flash" command requires additional information 1438 regarding the non-volatile storage device. Define this to 1439 the eMMC device that fastboot should use to store the image. 1440 1441 CONFIG_FASTBOOT_GPT_NAME 1442 The fastboot "flash" command supports writing the downloaded 1443 image to the Protective MBR and the Primary GUID Partition 1444 Table. (Additionally, this downloaded image is post-processed 1445 to generate and write the Backup GUID Partition Table.) 1446 This occurs when the specified "partition name" on the 1447 "fastboot flash" command line matches this value. 1448 The default is "gpt" if undefined. 1449 1450 CONFIG_FASTBOOT_MBR_NAME 1451 The fastboot "flash" command supports writing the downloaded 1452 image to DOS MBR. 1453 This occurs when the "partition name" specified on the 1454 "fastboot flash" command line matches this value. 1455 If not defined the default value "mbr" is used. 1456 1457- Journaling Flash filesystem support: 1458 CONFIG_JFFS2_NAND 1459 Define these for a default partition on a NAND device 1460 1461 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1462 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1463 Define these for a default partition on a NOR device 1464 1465- Keyboard Support: 1466 See Kconfig help for available keyboard drivers. 1467 1468 CONFIG_KEYBOARD 1469 1470 Define this to enable a custom keyboard support. 1471 This simply calls drv_keyboard_init() which must be 1472 defined in your board-specific files. This option is deprecated 1473 and is only used by novena. For new boards, use driver model 1474 instead. 1475 1476- Video support: 1477 CONFIG_FSL_DIU_FB 1478 Enable the Freescale DIU video driver. Reference boards for 1479 SOCs that have a DIU should define this macro to enable DIU 1480 support, and should also define these other macros: 1481 1482 CONFIG_SYS_DIU_ADDR 1483 CONFIG_VIDEO 1484 CONFIG_CFB_CONSOLE 1485 CONFIG_VIDEO_SW_CURSOR 1486 CONFIG_VGA_AS_SINGLE_DEVICE 1487 CONFIG_VIDEO_LOGO 1488 CONFIG_VIDEO_BMP_LOGO 1489 1490 The DIU driver will look for the 'video-mode' environment 1491 variable, and if defined, enable the DIU as a console during 1492 boot. See the documentation file doc/README.video for a 1493 description of this variable. 1494 1495- LCD Support: CONFIG_LCD 1496 1497 Define this to enable LCD support (for output to LCD 1498 display); also select one of the supported displays 1499 by defining one of these: 1500 1501 CONFIG_ATMEL_LCD: 1502 1503 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1504 1505 CONFIG_NEC_NL6448AC33: 1506 1507 NEC NL6448AC33-18. Active, color, single scan. 1508 1509 CONFIG_NEC_NL6448BC20 1510 1511 NEC NL6448BC20-08. 6.5", 640x480. 1512 Active, color, single scan. 1513 1514 CONFIG_NEC_NL6448BC33_54 1515 1516 NEC NL6448BC33-54. 10.4", 640x480. 1517 Active, color, single scan. 1518 1519 CONFIG_SHARP_16x9 1520 1521 Sharp 320x240. Active, color, single scan. 1522 It isn't 16x9, and I am not sure what it is. 1523 1524 CONFIG_SHARP_LQ64D341 1525 1526 Sharp LQ64D341 display, 640x480. 1527 Active, color, single scan. 1528 1529 CONFIG_HLD1045 1530 1531 HLD1045 display, 640x480. 1532 Active, color, single scan. 1533 1534 CONFIG_OPTREX_BW 1535 1536 Optrex CBL50840-2 NF-FW 99 22 M5 1537 or 1538 Hitachi LMG6912RPFC-00T 1539 or 1540 Hitachi SP14Q002 1541 1542 320x240. Black & white. 1543 1544 CONFIG_LCD_ALIGNMENT 1545 1546 Normally the LCD is page-aligned (typically 4KB). If this is 1547 defined then the LCD will be aligned to this value instead. 1548 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1549 here, since it is cheaper to change data cache settings on 1550 a per-section basis. 1551 1552 1553 CONFIG_LCD_ROTATION 1554 1555 Sometimes, for example if the display is mounted in portrait 1556 mode or even if it's mounted landscape but rotated by 180degree, 1557 we need to rotate our content of the display relative to the 1558 framebuffer, so that user can read the messages which are 1559 printed out. 1560 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1561 initialized with a given rotation from "vl_rot" out of 1562 "vidinfo_t" which is provided by the board specific code. 1563 The value for vl_rot is coded as following (matching to 1564 fbcon=rotate:<n> linux-kernel commandline): 1565 0 = no rotation respectively 0 degree 1566 1 = 90 degree rotation 1567 2 = 180 degree rotation 1568 3 = 270 degree rotation 1569 1570 If CONFIG_LCD_ROTATION is not defined, the console will be 1571 initialized with 0degree rotation. 1572 1573 CONFIG_LCD_BMP_RLE8 1574 1575 Support drawing of RLE8-compressed bitmaps on the LCD. 1576 1577 CONFIG_I2C_EDID 1578 1579 Enables an 'i2c edid' command which can read EDID 1580 information over I2C from an attached LCD display. 1581 1582- Splash Screen Support: CONFIG_SPLASH_SCREEN 1583 1584 If this option is set, the environment is checked for 1585 a variable "splashimage". If found, the usual display 1586 of logo, copyright and system information on the LCD 1587 is suppressed and the BMP image at the address 1588 specified in "splashimage" is loaded instead. The 1589 console is redirected to the "nulldev", too. This 1590 allows for a "silent" boot where a splash screen is 1591 loaded very quickly after power-on. 1592 1593 CONFIG_SPLASHIMAGE_GUARD 1594 1595 If this option is set, then U-Boot will prevent the environment 1596 variable "splashimage" from being set to a problematic address 1597 (see doc/README.displaying-bmps). 1598 This option is useful for targets where, due to alignment 1599 restrictions, an improperly aligned BMP image will cause a data 1600 abort. If you think you will not have problems with unaligned 1601 accesses (for example because your toolchain prevents them) 1602 there is no need to set this option. 1603 1604 CONFIG_SPLASH_SCREEN_ALIGN 1605 1606 If this option is set the splash image can be freely positioned 1607 on the screen. Environment variable "splashpos" specifies the 1608 position as "x,y". If a positive number is given it is used as 1609 number of pixel from left/top. If a negative number is given it 1610 is used as number of pixel from right/bottom. You can also 1611 specify 'm' for centering the image. 1612 1613 Example: 1614 setenv splashpos m,m 1615 => image at center of screen 1616 1617 setenv splashpos 30,20 1618 => image at x = 30 and y = 20 1619 1620 setenv splashpos -10,m 1621 => vertically centered image 1622 at x = dspWidth - bmpWidth - 9 1623 1624- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1625 1626 If this option is set, additionally to standard BMP 1627 images, gzipped BMP images can be displayed via the 1628 splashscreen support or the bmp command. 1629 1630- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1631 1632 If this option is set, 8-bit RLE compressed BMP images 1633 can be displayed via the splashscreen support or the 1634 bmp command. 1635 1636- Compression support: 1637 CONFIG_GZIP 1638 1639 Enabled by default to support gzip compressed images. 1640 1641 CONFIG_BZIP2 1642 1643 If this option is set, support for bzip2 compressed 1644 images is included. If not, only uncompressed and gzip 1645 compressed images are supported. 1646 1647 NOTE: the bzip2 algorithm requires a lot of RAM, so 1648 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1649 be at least 4MB. 1650 1651 CONFIG_LZO 1652 1653 If this option is set, support for LZO compressed images 1654 is included. 1655 1656- MII/PHY support: 1657 CONFIG_PHY_ADDR 1658 1659 The address of PHY on MII bus. 1660 1661 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1662 1663 The clock frequency of the MII bus 1664 1665 CONFIG_PHY_GIGE 1666 1667 If this option is set, support for speed/duplex 1668 detection of gigabit PHY is included. 1669 1670 CONFIG_PHY_RESET_DELAY 1671 1672 Some PHY like Intel LXT971A need extra delay after 1673 reset before any MII register access is possible. 1674 For such PHY, set this option to the usec delay 1675 required. (minimum 300usec for LXT971A) 1676 1677 CONFIG_PHY_CMD_DELAY (ppc4xx) 1678 1679 Some PHY like Intel LXT971A need extra delay after 1680 command issued before MII status register can be read 1681 1682- IP address: 1683 CONFIG_IPADDR 1684 1685 Define a default value for the IP address to use for 1686 the default Ethernet interface, in case this is not 1687 determined through e.g. bootp. 1688 (Environment variable "ipaddr") 1689 1690- Server IP address: 1691 CONFIG_SERVERIP 1692 1693 Defines a default value for the IP address of a TFTP 1694 server to contact when using the "tftboot" command. 1695 (Environment variable "serverip") 1696 1697 CONFIG_KEEP_SERVERADDR 1698 1699 Keeps the server's MAC address, in the env 'serveraddr' 1700 for passing to bootargs (like Linux's netconsole option) 1701 1702- Gateway IP address: 1703 CONFIG_GATEWAYIP 1704 1705 Defines a default value for the IP address of the 1706 default router where packets to other networks are 1707 sent to. 1708 (Environment variable "gatewayip") 1709 1710- Subnet mask: 1711 CONFIG_NETMASK 1712 1713 Defines a default value for the subnet mask (or 1714 routing prefix) which is used to determine if an IP 1715 address belongs to the local subnet or needs to be 1716 forwarded through a router. 1717 (Environment variable "netmask") 1718 1719- Multicast TFTP Mode: 1720 CONFIG_MCAST_TFTP 1721 1722 Defines whether you want to support multicast TFTP as per 1723 rfc-2090; for example to work with atftp. Lets lots of targets 1724 tftp down the same boot image concurrently. Note: the Ethernet 1725 driver in use must provide a function: mcast() to join/leave a 1726 multicast group. 1727 1728- BOOTP Recovery Mode: 1729 CONFIG_BOOTP_RANDOM_DELAY 1730 1731 If you have many targets in a network that try to 1732 boot using BOOTP, you may want to avoid that all 1733 systems send out BOOTP requests at precisely the same 1734 moment (which would happen for instance at recovery 1735 from a power failure, when all systems will try to 1736 boot, thus flooding the BOOTP server. Defining 1737 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1738 inserted before sending out BOOTP requests. The 1739 following delays are inserted then: 1740 1741 1st BOOTP request: delay 0 ... 1 sec 1742 2nd BOOTP request: delay 0 ... 2 sec 1743 3rd BOOTP request: delay 0 ... 4 sec 1744 4th and following 1745 BOOTP requests: delay 0 ... 8 sec 1746 1747 CONFIG_BOOTP_ID_CACHE_SIZE 1748 1749 BOOTP packets are uniquely identified using a 32-bit ID. The 1750 server will copy the ID from client requests to responses and 1751 U-Boot will use this to determine if it is the destination of 1752 an incoming response. Some servers will check that addresses 1753 aren't in use before handing them out (usually using an ARP 1754 ping) and therefore take up to a few hundred milliseconds to 1755 respond. Network congestion may also influence the time it 1756 takes for a response to make it back to the client. If that 1757 time is too long, U-Boot will retransmit requests. In order 1758 to allow earlier responses to still be accepted after these 1759 retransmissions, U-Boot's BOOTP client keeps a small cache of 1760 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1761 cache. The default is to keep IDs for up to four outstanding 1762 requests. Increasing this will allow U-Boot to accept offers 1763 from a BOOTP client in networks with unusually high latency. 1764 1765- DHCP Advanced Options: 1766 You can fine tune the DHCP functionality by defining 1767 CONFIG_BOOTP_* symbols: 1768 1769 CONFIG_BOOTP_SUBNETMASK 1770 CONFIG_BOOTP_GATEWAY 1771 CONFIG_BOOTP_HOSTNAME 1772 CONFIG_BOOTP_NISDOMAIN 1773 CONFIG_BOOTP_BOOTPATH 1774 CONFIG_BOOTP_BOOTFILESIZE 1775 CONFIG_BOOTP_DNS 1776 CONFIG_BOOTP_DNS2 1777 CONFIG_BOOTP_SEND_HOSTNAME 1778 CONFIG_BOOTP_NTPSERVER 1779 CONFIG_BOOTP_TIMEOFFSET 1780 CONFIG_BOOTP_VENDOREX 1781 CONFIG_BOOTP_MAY_FAIL 1782 1783 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1784 environment variable, not the BOOTP server. 1785 1786 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1787 after the configured retry count, the call will fail 1788 instead of starting over. This can be used to fail over 1789 to Link-local IP address configuration if the DHCP server 1790 is not available. 1791 1792 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1793 serverip from a DHCP server, it is possible that more 1794 than one DNS serverip is offered to the client. 1795 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1796 serverip will be stored in the additional environment 1797 variable "dnsip2". The first DNS serverip is always 1798 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1799 is defined. 1800 1801 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1802 to do a dynamic update of a DNS server. To do this, they 1803 need the hostname of the DHCP requester. 1804 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1805 of the "hostname" environment variable is passed as 1806 option 12 to the DHCP server. 1807 1808 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1809 1810 A 32bit value in microseconds for a delay between 1811 receiving a "DHCP Offer" and sending the "DHCP Request". 1812 This fixes a problem with certain DHCP servers that don't 1813 respond 100% of the time to a "DHCP request". E.g. On an 1814 AT91RM9200 processor running at 180MHz, this delay needed 1815 to be *at least* 15,000 usec before a Windows Server 2003 1816 DHCP server would reply 100% of the time. I recommend at 1817 least 50,000 usec to be safe. The alternative is to hope 1818 that one of the retries will be successful but note that 1819 the DHCP timeout and retry process takes a longer than 1820 this delay. 1821 1822 - Link-local IP address negotiation: 1823 Negotiate with other link-local clients on the local network 1824 for an address that doesn't require explicit configuration. 1825 This is especially useful if a DHCP server cannot be guaranteed 1826 to exist in all environments that the device must operate. 1827 1828 See doc/README.link-local for more information. 1829 1830 - CDP Options: 1831 CONFIG_CDP_DEVICE_ID 1832 1833 The device id used in CDP trigger frames. 1834 1835 CONFIG_CDP_DEVICE_ID_PREFIX 1836 1837 A two character string which is prefixed to the MAC address 1838 of the device. 1839 1840 CONFIG_CDP_PORT_ID 1841 1842 A printf format string which contains the ascii name of 1843 the port. Normally is set to "eth%d" which sets 1844 eth0 for the first Ethernet, eth1 for the second etc. 1845 1846 CONFIG_CDP_CAPABILITIES 1847 1848 A 32bit integer which indicates the device capabilities; 1849 0x00000010 for a normal host which does not forwards. 1850 1851 CONFIG_CDP_VERSION 1852 1853 An ascii string containing the version of the software. 1854 1855 CONFIG_CDP_PLATFORM 1856 1857 An ascii string containing the name of the platform. 1858 1859 CONFIG_CDP_TRIGGER 1860 1861 A 32bit integer sent on the trigger. 1862 1863 CONFIG_CDP_POWER_CONSUMPTION 1864 1865 A 16bit integer containing the power consumption of the 1866 device in .1 of milliwatts. 1867 1868 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1869 1870 A byte containing the id of the VLAN. 1871 1872- Status LED: CONFIG_LED_STATUS 1873 1874 Several configurations allow to display the current 1875 status using a LED. For instance, the LED will blink 1876 fast while running U-Boot code, stop blinking as 1877 soon as a reply to a BOOTP request was received, and 1878 start blinking slow once the Linux kernel is running 1879 (supported by a status LED driver in the Linux 1880 kernel). Defining CONFIG_LED_STATUS enables this 1881 feature in U-Boot. 1882 1883 Additional options: 1884 1885 CONFIG_LED_STATUS_GPIO 1886 The status LED can be connected to a GPIO pin. 1887 In such cases, the gpio_led driver can be used as a 1888 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1889 to include the gpio_led driver in the U-Boot binary. 1890 1891 CONFIG_GPIO_LED_INVERTED_TABLE 1892 Some GPIO connected LEDs may have inverted polarity in which 1893 case the GPIO high value corresponds to LED off state and 1894 GPIO low value corresponds to LED on state. 1895 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1896 with a list of GPIO LEDs that have inverted polarity. 1897 1898- I2C Support: CONFIG_SYS_I2C 1899 1900 This enable the NEW i2c subsystem, and will allow you to use 1901 i2c commands at the u-boot command line (as long as you set 1902 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1903 based realtime clock chips or other i2c devices. See 1904 common/cmd_i2c.c for a description of the command line 1905 interface. 1906 1907 ported i2c driver to the new framework: 1908 - drivers/i2c/soft_i2c.c: 1909 - activate first bus with CONFIG_SYS_I2C_SOFT define 1910 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1911 for defining speed and slave address 1912 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1913 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1914 for defining speed and slave address 1915 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1916 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1917 for defining speed and slave address 1918 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1919 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1920 for defining speed and slave address 1921 1922 - drivers/i2c/fsl_i2c.c: 1923 - activate i2c driver with CONFIG_SYS_I2C_FSL 1924 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1925 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1926 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1927 bus. 1928 - If your board supports a second fsl i2c bus, define 1929 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1930 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1931 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1932 second bus. 1933 1934 - drivers/i2c/tegra_i2c.c: 1935 - activate this driver with CONFIG_SYS_I2C_TEGRA 1936 - This driver adds 4 i2c buses with a fix speed from 1937 100000 and the slave addr 0! 1938 1939 - drivers/i2c/ppc4xx_i2c.c 1940 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1941 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1942 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1943 1944 - drivers/i2c/i2c_mxc.c 1945 - activate this driver with CONFIG_SYS_I2C_MXC 1946 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1947 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1948 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1949 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1950 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1951 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1952 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1953 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1954 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1955 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1956 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1957 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1958 If those defines are not set, default value is 100000 1959 for speed, and 0 for slave. 1960 1961 - drivers/i2c/rcar_i2c.c: 1962 - activate this driver with CONFIG_SYS_I2C_RCAR 1963 - This driver adds 4 i2c buses 1964 1965 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1966 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1967 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1968 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1969 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1970 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1971 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1972 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1973 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1974 1975 - drivers/i2c/sh_i2c.c: 1976 - activate this driver with CONFIG_SYS_I2C_SH 1977 - This driver adds from 2 to 5 i2c buses 1978 1979 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1980 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1981 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1982 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1983 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1984 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1985 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1986 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1987 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1988 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1989 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1990 1991 - drivers/i2c/omap24xx_i2c.c 1992 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1993 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1994 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1995 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1996 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1997 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1998 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1999 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 2000 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 2001 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 2002 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 2003 2004 - drivers/i2c/zynq_i2c.c 2005 - activate this driver with CONFIG_SYS_I2C_ZYNQ 2006 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 2007 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 2008 2009 - drivers/i2c/s3c24x0_i2c.c: 2010 - activate this driver with CONFIG_SYS_I2C_S3C24X0 2011 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 2012 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 2013 with a fix speed from 100000 and the slave addr 0! 2014 2015 - drivers/i2c/ihs_i2c.c 2016 - activate this driver with CONFIG_SYS_I2C_IHS 2017 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 2018 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 2019 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 2020 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 2021 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 2022 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 2023 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2024 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2025 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2026 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2027 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2028 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2029 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2030 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2031 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2032 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2033 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2034 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2035 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2036 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2037 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2038 2039 additional defines: 2040 2041 CONFIG_SYS_NUM_I2C_BUSES 2042 Hold the number of i2c buses you want to use. 2043 2044 CONFIG_SYS_I2C_DIRECT_BUS 2045 define this, if you don't use i2c muxes on your hardware. 2046 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2047 omit this define. 2048 2049 CONFIG_SYS_I2C_MAX_HOPS 2050 define how many muxes are maximal consecutively connected 2051 on one i2c bus. If you not use i2c muxes, omit this 2052 define. 2053 2054 CONFIG_SYS_I2C_BUSES 2055 hold a list of buses you want to use, only used if 2056 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2057 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2058 CONFIG_SYS_NUM_I2C_BUSES = 9: 2059 2060 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2061 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2062 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2063 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2064 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2065 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2066 {1, {I2C_NULL_HOP}}, \ 2067 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2068 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2069 } 2070 2071 which defines 2072 bus 0 on adapter 0 without a mux 2073 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2074 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2075 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2076 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2077 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2078 bus 6 on adapter 1 without a mux 2079 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2080 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2081 2082 If you do not have i2c muxes on your board, omit this define. 2083 2084- Legacy I2C Support: 2085 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2086 then the following macros need to be defined (examples are 2087 from include/configs/lwmon.h): 2088 2089 I2C_INIT 2090 2091 (Optional). Any commands necessary to enable the I2C 2092 controller or configure ports. 2093 2094 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2095 2096 I2C_ACTIVE 2097 2098 The code necessary to make the I2C data line active 2099 (driven). If the data line is open collector, this 2100 define can be null. 2101 2102 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2103 2104 I2C_TRISTATE 2105 2106 The code necessary to make the I2C data line tri-stated 2107 (inactive). If the data line is open collector, this 2108 define can be null. 2109 2110 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2111 2112 I2C_READ 2113 2114 Code that returns true if the I2C data line is high, 2115 false if it is low. 2116 2117 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2118 2119 I2C_SDA(bit) 2120 2121 If <bit> is true, sets the I2C data line high. If it 2122 is false, it clears it (low). 2123 2124 eg: #define I2C_SDA(bit) \ 2125 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2126 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2127 2128 I2C_SCL(bit) 2129 2130 If <bit> is true, sets the I2C clock line high. If it 2131 is false, it clears it (low). 2132 2133 eg: #define I2C_SCL(bit) \ 2134 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2135 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2136 2137 I2C_DELAY 2138 2139 This delay is invoked four times per clock cycle so this 2140 controls the rate of data transfer. The data rate thus 2141 is 1 / (I2C_DELAY * 4). Often defined to be something 2142 like: 2143 2144 #define I2C_DELAY udelay(2) 2145 2146 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2147 2148 If your arch supports the generic GPIO framework (asm/gpio.h), 2149 then you may alternatively define the two GPIOs that are to be 2150 used as SCL / SDA. Any of the previous I2C_xxx macros will 2151 have GPIO-based defaults assigned to them as appropriate. 2152 2153 You should define these to the GPIO value as given directly to 2154 the generic GPIO functions. 2155 2156 CONFIG_SYS_I2C_INIT_BOARD 2157 2158 When a board is reset during an i2c bus transfer 2159 chips might think that the current transfer is still 2160 in progress. On some boards it is possible to access 2161 the i2c SCLK line directly, either by using the 2162 processor pin as a GPIO or by having a second pin 2163 connected to the bus. If this option is defined a 2164 custom i2c_init_board() routine in boards/xxx/board.c 2165 is run early in the boot sequence. 2166 2167 CONFIG_I2C_MULTI_BUS 2168 2169 This option allows the use of multiple I2C buses, each of which 2170 must have a controller. At any point in time, only one bus is 2171 active. To switch to a different bus, use the 'i2c dev' command. 2172 Note that bus numbering is zero-based. 2173 2174 CONFIG_SYS_I2C_NOPROBES 2175 2176 This option specifies a list of I2C devices that will be skipped 2177 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2178 is set, specify a list of bus-device pairs. Otherwise, specify 2179 a 1D array of device addresses 2180 2181 e.g. 2182 #undef CONFIG_I2C_MULTI_BUS 2183 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2184 2185 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2186 2187 #define CONFIG_I2C_MULTI_BUS 2188 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2189 2190 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2191 2192 CONFIG_SYS_SPD_BUS_NUM 2193 2194 If defined, then this indicates the I2C bus number for DDR SPD. 2195 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2196 2197 CONFIG_SYS_RTC_BUS_NUM 2198 2199 If defined, then this indicates the I2C bus number for the RTC. 2200 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2201 2202 CONFIG_SOFT_I2C_READ_REPEATED_START 2203 2204 defining this will force the i2c_read() function in 2205 the soft_i2c driver to perform an I2C repeated start 2206 between writing the address pointer and reading the 2207 data. If this define is omitted the default behaviour 2208 of doing a stop-start sequence will be used. Most I2C 2209 devices can use either method, but some require one or 2210 the other. 2211 2212- SPI Support: CONFIG_SPI 2213 2214 Enables SPI driver (so far only tested with 2215 SPI EEPROM, also an instance works with Crystal A/D and 2216 D/As on the SACSng board) 2217 2218 CONFIG_SH_SPI 2219 2220 Enables the driver for SPI controller on SuperH. Currently 2221 only SH7757 is supported. 2222 2223 CONFIG_SOFT_SPI 2224 2225 Enables a software (bit-bang) SPI driver rather than 2226 using hardware support. This is a general purpose 2227 driver that only requires three general I/O port pins 2228 (two outputs, one input) to function. If this is 2229 defined, the board configuration must define several 2230 SPI configuration items (port pins to use, etc). For 2231 an example, see include/configs/sacsng.h. 2232 2233 CONFIG_HARD_SPI 2234 2235 Enables a hardware SPI driver for general-purpose reads 2236 and writes. As with CONFIG_SOFT_SPI, the board configuration 2237 must define a list of chip-select function pointers. 2238 Currently supported on some MPC8xxx processors. For an 2239 example, see include/configs/mpc8349emds.h. 2240 2241 CONFIG_MXC_SPI 2242 2243 Enables the driver for the SPI controllers on i.MX and MXC 2244 SoCs. Currently i.MX31/35/51 are supported. 2245 2246 CONFIG_SYS_SPI_MXC_WAIT 2247 Timeout for waiting until spi transfer completed. 2248 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2249 2250- FPGA Support: CONFIG_FPGA 2251 2252 Enables FPGA subsystem. 2253 2254 CONFIG_FPGA_<vendor> 2255 2256 Enables support for specific chip vendors. 2257 (ALTERA, XILINX) 2258 2259 CONFIG_FPGA_<family> 2260 2261 Enables support for FPGA family. 2262 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2263 2264 CONFIG_FPGA_COUNT 2265 2266 Specify the number of FPGA devices to support. 2267 2268 CONFIG_SYS_FPGA_PROG_FEEDBACK 2269 2270 Enable printing of hash marks during FPGA configuration. 2271 2272 CONFIG_SYS_FPGA_CHECK_BUSY 2273 2274 Enable checks on FPGA configuration interface busy 2275 status by the configuration function. This option 2276 will require a board or device specific function to 2277 be written. 2278 2279 CONFIG_FPGA_DELAY 2280 2281 If defined, a function that provides delays in the FPGA 2282 configuration driver. 2283 2284 CONFIG_SYS_FPGA_CHECK_CTRLC 2285 Allow Control-C to interrupt FPGA configuration 2286 2287 CONFIG_SYS_FPGA_CHECK_ERROR 2288 2289 Check for configuration errors during FPGA bitfile 2290 loading. For example, abort during Virtex II 2291 configuration if the INIT_B line goes low (which 2292 indicated a CRC error). 2293 2294 CONFIG_SYS_FPGA_WAIT_INIT 2295 2296 Maximum time to wait for the INIT_B line to de-assert 2297 after PROB_B has been de-asserted during a Virtex II 2298 FPGA configuration sequence. The default time is 500 2299 ms. 2300 2301 CONFIG_SYS_FPGA_WAIT_BUSY 2302 2303 Maximum time to wait for BUSY to de-assert during 2304 Virtex II FPGA configuration. The default is 5 ms. 2305 2306 CONFIG_SYS_FPGA_WAIT_CONFIG 2307 2308 Time to wait after FPGA configuration. The default is 2309 200 ms. 2310 2311- Configuration Management: 2312 CONFIG_BUILD_TARGET 2313 2314 Some SoCs need special image types (e.g. U-Boot binary 2315 with a special header) as build targets. By defining 2316 CONFIG_BUILD_TARGET in the SoC / board header, this 2317 special image will be automatically built upon calling 2318 make / buildman. 2319 2320 CONFIG_IDENT_STRING 2321 2322 If defined, this string will be added to the U-Boot 2323 version information (U_BOOT_VERSION) 2324 2325- Vendor Parameter Protection: 2326 2327 U-Boot considers the values of the environment 2328 variables "serial#" (Board Serial Number) and 2329 "ethaddr" (Ethernet Address) to be parameters that 2330 are set once by the board vendor / manufacturer, and 2331 protects these variables from casual modification by 2332 the user. Once set, these variables are read-only, 2333 and write or delete attempts are rejected. You can 2334 change this behaviour: 2335 2336 If CONFIG_ENV_OVERWRITE is #defined in your config 2337 file, the write protection for vendor parameters is 2338 completely disabled. Anybody can change or delete 2339 these parameters. 2340 2341 Alternatively, if you define _both_ an ethaddr in the 2342 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2343 Ethernet address is installed in the environment, 2344 which can be changed exactly ONCE by the user. [The 2345 serial# is unaffected by this, i. e. it remains 2346 read-only.] 2347 2348 The same can be accomplished in a more flexible way 2349 for any variable by configuring the type of access 2350 to allow for those variables in the ".flags" variable 2351 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2352 2353- Protected RAM: 2354 CONFIG_PRAM 2355 2356 Define this variable to enable the reservation of 2357 "protected RAM", i. e. RAM which is not overwritten 2358 by U-Boot. Define CONFIG_PRAM to hold the number of 2359 kB you want to reserve for pRAM. You can overwrite 2360 this default value by defining an environment 2361 variable "pram" to the number of kB you want to 2362 reserve. Note that the board info structure will 2363 still show the full amount of RAM. If pRAM is 2364 reserved, a new environment variable "mem" will 2365 automatically be defined to hold the amount of 2366 remaining RAM in a form that can be passed as boot 2367 argument to Linux, for instance like that: 2368 2369 setenv bootargs ... mem=\${mem} 2370 saveenv 2371 2372 This way you can tell Linux not to use this memory, 2373 either, which results in a memory region that will 2374 not be affected by reboots. 2375 2376 *WARNING* If your board configuration uses automatic 2377 detection of the RAM size, you must make sure that 2378 this memory test is non-destructive. So far, the 2379 following board configurations are known to be 2380 "pRAM-clean": 2381 2382 IVMS8, IVML24, SPD8xx, 2383 HERMES, IP860, RPXlite, LWMON, 2384 FLAGADM 2385 2386- Access to physical memory region (> 4GB) 2387 Some basic support is provided for operations on memory not 2388 normally accessible to U-Boot - e.g. some architectures 2389 support access to more than 4GB of memory on 32-bit 2390 machines using physical address extension or similar. 2391 Define CONFIG_PHYSMEM to access this basic support, which 2392 currently only supports clearing the memory. 2393 2394- Error Recovery: 2395 CONFIG_PANIC_HANG 2396 2397 Define this variable to stop the system in case of a 2398 fatal error, so that you have to reset it manually. 2399 This is probably NOT a good idea for an embedded 2400 system where you want the system to reboot 2401 automatically as fast as possible, but it may be 2402 useful during development since you can try to debug 2403 the conditions that lead to the situation. 2404 2405 CONFIG_NET_RETRY_COUNT 2406 2407 This variable defines the number of retries for 2408 network operations like ARP, RARP, TFTP, or BOOTP 2409 before giving up the operation. If not defined, a 2410 default value of 5 is used. 2411 2412 CONFIG_ARP_TIMEOUT 2413 2414 Timeout waiting for an ARP reply in milliseconds. 2415 2416 CONFIG_NFS_TIMEOUT 2417 2418 Timeout in milliseconds used in NFS protocol. 2419 If you encounter "ERROR: Cannot umount" in nfs command, 2420 try longer timeout such as 2421 #define CONFIG_NFS_TIMEOUT 10000UL 2422 2423- Command Interpreter: 2424 CONFIG_AUTO_COMPLETE 2425 2426 Enable auto completion of commands using TAB. 2427 2428 CONFIG_SYS_PROMPT_HUSH_PS2 2429 2430 This defines the secondary prompt string, which is 2431 printed when the command interpreter needs more input 2432 to complete a command. Usually "> ". 2433 2434 Note: 2435 2436 In the current implementation, the local variables 2437 space and global environment variables space are 2438 separated. Local variables are those you define by 2439 simply typing `name=value'. To access a local 2440 variable later on, you have write `$name' or 2441 `${name}'; to execute the contents of a variable 2442 directly type `$name' at the command prompt. 2443 2444 Global environment variables are those you use 2445 setenv/printenv to work with. To run a command stored 2446 in such a variable, you need to use the run command, 2447 and you must not use the '$' sign to access them. 2448 2449 To store commands and special characters in a 2450 variable, please use double quotation marks 2451 surrounding the whole text of the variable, instead 2452 of the backslashes before semicolons and special 2453 symbols. 2454 2455- Command Line Editing and History: 2456 CONFIG_CMDLINE_EDITING 2457 2458 Enable editing and History functions for interactive 2459 command line input operations 2460 2461- Command Line PS1/PS2 support: 2462 CONFIG_CMDLINE_PS_SUPPORT 2463 2464 Enable support for changing the command prompt string 2465 at run-time. Only static string is supported so far. 2466 The string is obtained from environment variables PS1 2467 and PS2. 2468 2469- Default Environment: 2470 CONFIG_EXTRA_ENV_SETTINGS 2471 2472 Define this to contain any number of null terminated 2473 strings (variable = value pairs) that will be part of 2474 the default environment compiled into the boot image. 2475 2476 For example, place something like this in your 2477 board's config file: 2478 2479 #define CONFIG_EXTRA_ENV_SETTINGS \ 2480 "myvar1=value1\0" \ 2481 "myvar2=value2\0" 2482 2483 Warning: This method is based on knowledge about the 2484 internal format how the environment is stored by the 2485 U-Boot code. This is NOT an official, exported 2486 interface! Although it is unlikely that this format 2487 will change soon, there is no guarantee either. 2488 You better know what you are doing here. 2489 2490 Note: overly (ab)use of the default environment is 2491 discouraged. Make sure to check other ways to preset 2492 the environment like the "source" command or the 2493 boot command first. 2494 2495 CONFIG_ENV_VARS_UBOOT_CONFIG 2496 2497 Define this in order to add variables describing the 2498 U-Boot build configuration to the default environment. 2499 These will be named arch, cpu, board, vendor, and soc. 2500 2501 Enabling this option will cause the following to be defined: 2502 2503 - CONFIG_SYS_ARCH 2504 - CONFIG_SYS_CPU 2505 - CONFIG_SYS_BOARD 2506 - CONFIG_SYS_VENDOR 2507 - CONFIG_SYS_SOC 2508 2509 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2510 2511 Define this in order to add variables describing certain 2512 run-time determined information about the hardware to the 2513 environment. These will be named board_name, board_rev. 2514 2515 CONFIG_DELAY_ENVIRONMENT 2516 2517 Normally the environment is loaded when the board is 2518 initialised so that it is available to U-Boot. This inhibits 2519 that so that the environment is not available until 2520 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2521 this is instead controlled by the value of 2522 /config/load-environment. 2523 2524- DataFlash Support: 2525 CONFIG_HAS_DATAFLASH 2526 2527 Defining this option enables DataFlash features and 2528 allows to read/write in Dataflash via the standard 2529 commands cp, md... 2530 2531- Serial Flash support 2532 CONFIG_CMD_SF 2533 2534 Defining this option enables SPI flash commands 2535 'sf probe/read/write/erase/update'. 2536 2537 Usage requires an initial 'probe' to define the serial 2538 flash parameters, followed by read/write/erase/update 2539 commands. 2540 2541 The following defaults may be provided by the platform 2542 to handle the common case when only a single serial 2543 flash is present on the system. 2544 2545 CONFIG_SF_DEFAULT_BUS Bus identifier 2546 CONFIG_SF_DEFAULT_CS Chip-select 2547 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2548 CONFIG_SF_DEFAULT_SPEED in Hz 2549 2550 CONFIG_CMD_SF_TEST 2551 2552 Define this option to include a destructive SPI flash 2553 test ('sf test'). 2554 2555- SystemACE Support: 2556 CONFIG_SYSTEMACE 2557 2558 Adding this option adds support for Xilinx SystemACE 2559 chips attached via some sort of local bus. The address 2560 of the chip must also be defined in the 2561 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2562 2563 #define CONFIG_SYSTEMACE 2564 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2565 2566 When SystemACE support is added, the "ace" device type 2567 becomes available to the fat commands, i.e. fatls. 2568 2569- TFTP Fixed UDP Port: 2570 CONFIG_TFTP_PORT 2571 2572 If this is defined, the environment variable tftpsrcp 2573 is used to supply the TFTP UDP source port value. 2574 If tftpsrcp isn't defined, the normal pseudo-random port 2575 number generator is used. 2576 2577 Also, the environment variable tftpdstp is used to supply 2578 the TFTP UDP destination port value. If tftpdstp isn't 2579 defined, the normal port 69 is used. 2580 2581 The purpose for tftpsrcp is to allow a TFTP server to 2582 blindly start the TFTP transfer using the pre-configured 2583 target IP address and UDP port. This has the effect of 2584 "punching through" the (Windows XP) firewall, allowing 2585 the remainder of the TFTP transfer to proceed normally. 2586 A better solution is to properly configure the firewall, 2587 but sometimes that is not allowed. 2588 2589- bootcount support: 2590 CONFIG_BOOTCOUNT_LIMIT 2591 2592 This enables the bootcounter support, see: 2593 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2594 2595 CONFIG_AT91SAM9XE 2596 enable special bootcounter support on at91sam9xe based boards. 2597 CONFIG_SOC_DA8XX 2598 enable special bootcounter support on da850 based boards. 2599 CONFIG_BOOTCOUNT_RAM 2600 enable support for the bootcounter in RAM 2601 CONFIG_BOOTCOUNT_I2C 2602 enable support for the bootcounter on an i2c (like RTC) device. 2603 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2604 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2605 the bootcounter. 2606 CONFIG_BOOTCOUNT_ALEN = address len 2607 2608- Show boot progress: 2609 CONFIG_SHOW_BOOT_PROGRESS 2610 2611 Defining this option allows to add some board- 2612 specific code (calling a user-provided function 2613 "show_boot_progress(int)") that enables you to show 2614 the system's boot progress on some display (for 2615 example, some LED's) on your board. At the moment, 2616 the following checkpoints are implemented: 2617 2618 2619Legacy uImage format: 2620 2621 Arg Where When 2622 1 common/cmd_bootm.c before attempting to boot an image 2623 -1 common/cmd_bootm.c Image header has bad magic number 2624 2 common/cmd_bootm.c Image header has correct magic number 2625 -2 common/cmd_bootm.c Image header has bad checksum 2626 3 common/cmd_bootm.c Image header has correct checksum 2627 -3 common/cmd_bootm.c Image data has bad checksum 2628 4 common/cmd_bootm.c Image data has correct checksum 2629 -4 common/cmd_bootm.c Image is for unsupported architecture 2630 5 common/cmd_bootm.c Architecture check OK 2631 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2632 6 common/cmd_bootm.c Image Type check OK 2633 -6 common/cmd_bootm.c gunzip uncompression error 2634 -7 common/cmd_bootm.c Unimplemented compression type 2635 7 common/cmd_bootm.c Uncompression OK 2636 8 common/cmd_bootm.c No uncompress/copy overwrite error 2637 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2638 2639 9 common/image.c Start initial ramdisk verification 2640 -10 common/image.c Ramdisk header has bad magic number 2641 -11 common/image.c Ramdisk header has bad checksum 2642 10 common/image.c Ramdisk header is OK 2643 -12 common/image.c Ramdisk data has bad checksum 2644 11 common/image.c Ramdisk data has correct checksum 2645 12 common/image.c Ramdisk verification complete, start loading 2646 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2647 13 common/image.c Start multifile image verification 2648 14 common/image.c No initial ramdisk, no multifile, continue. 2649 2650 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2651 2652 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2653 -31 post/post.c POST test failed, detected by post_output_backlog() 2654 -32 post/post.c POST test failed, detected by post_run_single() 2655 2656 34 common/cmd_doc.c before loading a Image from a DOC device 2657 -35 common/cmd_doc.c Bad usage of "doc" command 2658 35 common/cmd_doc.c correct usage of "doc" command 2659 -36 common/cmd_doc.c No boot device 2660 36 common/cmd_doc.c correct boot device 2661 -37 common/cmd_doc.c Unknown Chip ID on boot device 2662 37 common/cmd_doc.c correct chip ID found, device available 2663 -38 common/cmd_doc.c Read Error on boot device 2664 38 common/cmd_doc.c reading Image header from DOC device OK 2665 -39 common/cmd_doc.c Image header has bad magic number 2666 39 common/cmd_doc.c Image header has correct magic number 2667 -40 common/cmd_doc.c Error reading Image from DOC device 2668 40 common/cmd_doc.c Image header has correct magic number 2669 41 common/cmd_ide.c before loading a Image from a IDE device 2670 -42 common/cmd_ide.c Bad usage of "ide" command 2671 42 common/cmd_ide.c correct usage of "ide" command 2672 -43 common/cmd_ide.c No boot device 2673 43 common/cmd_ide.c boot device found 2674 -44 common/cmd_ide.c Device not available 2675 44 common/cmd_ide.c Device available 2676 -45 common/cmd_ide.c wrong partition selected 2677 45 common/cmd_ide.c partition selected 2678 -46 common/cmd_ide.c Unknown partition table 2679 46 common/cmd_ide.c valid partition table found 2680 -47 common/cmd_ide.c Invalid partition type 2681 47 common/cmd_ide.c correct partition type 2682 -48 common/cmd_ide.c Error reading Image Header on boot device 2683 48 common/cmd_ide.c reading Image Header from IDE device OK 2684 -49 common/cmd_ide.c Image header has bad magic number 2685 49 common/cmd_ide.c Image header has correct magic number 2686 -50 common/cmd_ide.c Image header has bad checksum 2687 50 common/cmd_ide.c Image header has correct checksum 2688 -51 common/cmd_ide.c Error reading Image from IDE device 2689 51 common/cmd_ide.c reading Image from IDE device OK 2690 52 common/cmd_nand.c before loading a Image from a NAND device 2691 -53 common/cmd_nand.c Bad usage of "nand" command 2692 53 common/cmd_nand.c correct usage of "nand" command 2693 -54 common/cmd_nand.c No boot device 2694 54 common/cmd_nand.c boot device found 2695 -55 common/cmd_nand.c Unknown Chip ID on boot device 2696 55 common/cmd_nand.c correct chip ID found, device available 2697 -56 common/cmd_nand.c Error reading Image Header on boot device 2698 56 common/cmd_nand.c reading Image Header from NAND device OK 2699 -57 common/cmd_nand.c Image header has bad magic number 2700 57 common/cmd_nand.c Image header has correct magic number 2701 -58 common/cmd_nand.c Error reading Image from NAND device 2702 58 common/cmd_nand.c reading Image from NAND device OK 2703 2704 -60 common/env_common.c Environment has a bad CRC, using default 2705 2706 64 net/eth.c starting with Ethernet configuration. 2707 -64 net/eth.c no Ethernet found. 2708 65 net/eth.c Ethernet found. 2709 2710 -80 common/cmd_net.c usage wrong 2711 80 common/cmd_net.c before calling net_loop() 2712 -81 common/cmd_net.c some error in net_loop() occurred 2713 81 common/cmd_net.c net_loop() back without error 2714 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2715 82 common/cmd_net.c trying automatic boot 2716 83 common/cmd_net.c running "source" command 2717 -83 common/cmd_net.c some error in automatic boot or "source" command 2718 84 common/cmd_net.c end without errors 2719 2720FIT uImage format: 2721 2722 Arg Where When 2723 100 common/cmd_bootm.c Kernel FIT Image has correct format 2724 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2725 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2726 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2727 102 common/cmd_bootm.c Kernel unit name specified 2728 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2729 103 common/cmd_bootm.c Found configuration node 2730 104 common/cmd_bootm.c Got kernel subimage node offset 2731 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2732 105 common/cmd_bootm.c Kernel subimage hash verification OK 2733 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2734 106 common/cmd_bootm.c Architecture check OK 2735 -106 common/cmd_bootm.c Kernel subimage has wrong type 2736 107 common/cmd_bootm.c Kernel subimage type OK 2737 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2738 108 common/cmd_bootm.c Got kernel subimage data/size 2739 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2740 -109 common/cmd_bootm.c Can't get kernel subimage type 2741 -110 common/cmd_bootm.c Can't get kernel subimage comp 2742 -111 common/cmd_bootm.c Can't get kernel subimage os 2743 -112 common/cmd_bootm.c Can't get kernel subimage load address 2744 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2745 2746 120 common/image.c Start initial ramdisk verification 2747 -120 common/image.c Ramdisk FIT image has incorrect format 2748 121 common/image.c Ramdisk FIT image has correct format 2749 122 common/image.c No ramdisk subimage unit name, using configuration 2750 -122 common/image.c Can't get configuration for ramdisk subimage 2751 123 common/image.c Ramdisk unit name specified 2752 -124 common/image.c Can't get ramdisk subimage node offset 2753 125 common/image.c Got ramdisk subimage node offset 2754 -125 common/image.c Ramdisk subimage hash verification failed 2755 126 common/image.c Ramdisk subimage hash verification OK 2756 -126 common/image.c Ramdisk subimage for unsupported architecture 2757 127 common/image.c Architecture check OK 2758 -127 common/image.c Can't get ramdisk subimage data/size 2759 128 common/image.c Got ramdisk subimage data/size 2760 129 common/image.c Can't get ramdisk load address 2761 -129 common/image.c Got ramdisk load address 2762 2763 -130 common/cmd_doc.c Incorrect FIT image format 2764 131 common/cmd_doc.c FIT image format OK 2765 2766 -140 common/cmd_ide.c Incorrect FIT image format 2767 141 common/cmd_ide.c FIT image format OK 2768 2769 -150 common/cmd_nand.c Incorrect FIT image format 2770 151 common/cmd_nand.c FIT image format OK 2771 2772- legacy image format: 2773 CONFIG_IMAGE_FORMAT_LEGACY 2774 enables the legacy image format support in U-Boot. 2775 2776 Default: 2777 enabled if CONFIG_FIT_SIGNATURE is not defined. 2778 2779 CONFIG_DISABLE_IMAGE_LEGACY 2780 disable the legacy image format 2781 2782 This define is introduced, as the legacy image format is 2783 enabled per default for backward compatibility. 2784 2785- Standalone program support: 2786 CONFIG_STANDALONE_LOAD_ADDR 2787 2788 This option defines a board specific value for the 2789 address where standalone program gets loaded, thus 2790 overwriting the architecture dependent default 2791 settings. 2792 2793- Frame Buffer Address: 2794 CONFIG_FB_ADDR 2795 2796 Define CONFIG_FB_ADDR if you want to use specific 2797 address for frame buffer. This is typically the case 2798 when using a graphics controller has separate video 2799 memory. U-Boot will then place the frame buffer at 2800 the given address instead of dynamically reserving it 2801 in system RAM by calling lcd_setmem(), which grabs 2802 the memory for the frame buffer depending on the 2803 configured panel size. 2804 2805 Please see board_init_f function. 2806 2807- Automatic software updates via TFTP server 2808 CONFIG_UPDATE_TFTP 2809 CONFIG_UPDATE_TFTP_CNT_MAX 2810 CONFIG_UPDATE_TFTP_MSEC_MAX 2811 2812 These options enable and control the auto-update feature; 2813 for a more detailed description refer to doc/README.update. 2814 2815- MTD Support (mtdparts command, UBI support) 2816 CONFIG_MTD_DEVICE 2817 2818 Adds the MTD device infrastructure from the Linux kernel. 2819 Needed for mtdparts command support. 2820 2821 CONFIG_MTD_PARTITIONS 2822 2823 Adds the MTD partitioning infrastructure from the Linux 2824 kernel. Needed for UBI support. 2825 2826- UBI support 2827 CONFIG_CMD_UBI 2828 2829 Adds commands for interacting with MTD partitions formatted 2830 with the UBI flash translation layer 2831 2832 Requires also defining CONFIG_RBTREE 2833 2834 CONFIG_UBI_SILENCE_MSG 2835 2836 Make the verbose messages from UBI stop printing. This leaves 2837 warnings and errors enabled. 2838 2839 2840 CONFIG_MTD_UBI_WL_THRESHOLD 2841 This parameter defines the maximum difference between the highest 2842 erase counter value and the lowest erase counter value of eraseblocks 2843 of UBI devices. When this threshold is exceeded, UBI starts performing 2844 wear leveling by means of moving data from eraseblock with low erase 2845 counter to eraseblocks with high erase counter. 2846 2847 The default value should be OK for SLC NAND flashes, NOR flashes and 2848 other flashes which have eraseblock life-cycle 100000 or more. 2849 However, in case of MLC NAND flashes which typically have eraseblock 2850 life-cycle less than 10000, the threshold should be lessened (e.g., 2851 to 128 or 256, although it does not have to be power of 2). 2852 2853 default: 4096 2854 2855 CONFIG_MTD_UBI_BEB_LIMIT 2856 This option specifies the maximum bad physical eraseblocks UBI 2857 expects on the MTD device (per 1024 eraseblocks). If the 2858 underlying flash does not admit of bad eraseblocks (e.g. NOR 2859 flash), this value is ignored. 2860 2861 NAND datasheets often specify the minimum and maximum NVM 2862 (Number of Valid Blocks) for the flashes' endurance lifetime. 2863 The maximum expected bad eraseblocks per 1024 eraseblocks 2864 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2865 which gives 20 for most NANDs (MaxNVB is basically the total 2866 count of eraseblocks on the chip). 2867 2868 To put it differently, if this value is 20, UBI will try to 2869 reserve about 1.9% of physical eraseblocks for bad blocks 2870 handling. And that will be 1.9% of eraseblocks on the entire 2871 NAND chip, not just the MTD partition UBI attaches. This means 2872 that if you have, say, a NAND flash chip admits maximum 40 bad 2873 eraseblocks, and it is split on two MTD partitions of the same 2874 size, UBI will reserve 40 eraseblocks when attaching a 2875 partition. 2876 2877 default: 20 2878 2879 CONFIG_MTD_UBI_FASTMAP 2880 Fastmap is a mechanism which allows attaching an UBI device 2881 in nearly constant time. Instead of scanning the whole MTD device it 2882 only has to locate a checkpoint (called fastmap) on the device. 2883 The on-flash fastmap contains all information needed to attach 2884 the device. Using fastmap makes only sense on large devices where 2885 attaching by scanning takes long. UBI will not automatically install 2886 a fastmap on old images, but you can set the UBI parameter 2887 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2888 that fastmap-enabled images are still usable with UBI implementations 2889 without fastmap support. On typical flash devices the whole fastmap 2890 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2891 2892 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2893 Set this parameter to enable fastmap automatically on images 2894 without a fastmap. 2895 default: 0 2896 2897 CONFIG_MTD_UBI_FM_DEBUG 2898 Enable UBI fastmap debug 2899 default: 0 2900 2901- UBIFS support 2902 CONFIG_CMD_UBIFS 2903 2904 Adds commands for interacting with UBI volumes formatted as 2905 UBIFS. UBIFS is read-only in u-boot. 2906 2907 Requires UBI support as well as CONFIG_LZO 2908 2909 CONFIG_UBIFS_SILENCE_MSG 2910 2911 Make the verbose messages from UBIFS stop printing. This leaves 2912 warnings and errors enabled. 2913 2914- SPL framework 2915 CONFIG_SPL 2916 Enable building of SPL globally. 2917 2918 CONFIG_SPL_LDSCRIPT 2919 LDSCRIPT for linking the SPL binary. 2920 2921 CONFIG_SPL_MAX_FOOTPRINT 2922 Maximum size in memory allocated to the SPL, BSS included. 2923 When defined, the linker checks that the actual memory 2924 used by SPL from _start to __bss_end does not exceed it. 2925 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2926 must not be both defined at the same time. 2927 2928 CONFIG_SPL_MAX_SIZE 2929 Maximum size of the SPL image (text, data, rodata, and 2930 linker lists sections), BSS excluded. 2931 When defined, the linker checks that the actual size does 2932 not exceed it. 2933 2934 CONFIG_SPL_TEXT_BASE 2935 TEXT_BASE for linking the SPL binary. 2936 2937 CONFIG_SPL_RELOC_TEXT_BASE 2938 Address to relocate to. If unspecified, this is equal to 2939 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2940 2941 CONFIG_SPL_BSS_START_ADDR 2942 Link address for the BSS within the SPL binary. 2943 2944 CONFIG_SPL_BSS_MAX_SIZE 2945 Maximum size in memory allocated to the SPL BSS. 2946 When defined, the linker checks that the actual memory used 2947 by SPL from __bss_start to __bss_end does not exceed it. 2948 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2949 must not be both defined at the same time. 2950 2951 CONFIG_SPL_STACK 2952 Adress of the start of the stack SPL will use 2953 2954 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2955 When defined, SPL will panic() if the image it has 2956 loaded does not have a signature. 2957 Defining this is useful when code which loads images 2958 in SPL cannot guarantee that absolutely all read errors 2959 will be caught. 2960 An example is the LPC32XX MLC NAND driver, which will 2961 consider that a completely unreadable NAND block is bad, 2962 and thus should be skipped silently. 2963 2964 CONFIG_SPL_RELOC_STACK 2965 Adress of the start of the stack SPL will use after 2966 relocation. If unspecified, this is equal to 2967 CONFIG_SPL_STACK. 2968 2969 CONFIG_SYS_SPL_MALLOC_START 2970 Starting address of the malloc pool used in SPL. 2971 When this option is set the full malloc is used in SPL and 2972 it is set up by spl_init() and before that, the simple malloc() 2973 can be used if CONFIG_SYS_MALLOC_F is defined. 2974 2975 CONFIG_SYS_SPL_MALLOC_SIZE 2976 The size of the malloc pool used in SPL. 2977 2978 CONFIG_SPL_FRAMEWORK 2979 Enable the SPL framework under common/. This framework 2980 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2981 NAND loading of the Linux Kernel. 2982 2983 CONFIG_SPL_OS_BOOT 2984 Enable booting directly to an OS from SPL. 2985 See also: doc/README.falcon 2986 2987 CONFIG_SPL_DISPLAY_PRINT 2988 For ARM, enable an optional function to print more information 2989 about the running system. 2990 2991 CONFIG_SPL_INIT_MINIMAL 2992 Arch init code should be built for a very small image 2993 2994 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2995 Partition on the MMC to load U-Boot from when the MMC is being 2996 used in raw mode 2997 2998 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2999 Sector to load kernel uImage from when MMC is being 3000 used in raw mode (for Falcon mode) 3001 3002 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 3003 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 3004 Sector and number of sectors to load kernel argument 3005 parameters from when MMC is being used in raw mode 3006 (for falcon mode) 3007 3008 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 3009 Partition on the MMC to load U-Boot from when the MMC is being 3010 used in fs mode 3011 3012 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 3013 Filename to read to load U-Boot when reading from filesystem 3014 3015 CONFIG_SPL_FS_LOAD_KERNEL_NAME 3016 Filename to read to load kernel uImage when reading 3017 from filesystem (for Falcon mode) 3018 3019 CONFIG_SPL_FS_LOAD_ARGS_NAME 3020 Filename to read to load kernel argument parameters 3021 when reading from filesystem (for Falcon mode) 3022 3023 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3024 Set this for NAND SPL on PPC mpc83xx targets, so that 3025 start.S waits for the rest of the SPL to load before 3026 continuing (the hardware starts execution after just 3027 loading the first page rather than the full 4K). 3028 3029 CONFIG_SPL_SKIP_RELOCATE 3030 Avoid SPL relocation 3031 3032 CONFIG_SPL_NAND_BASE 3033 Include nand_base.c in the SPL. Requires 3034 CONFIG_SPL_NAND_DRIVERS. 3035 3036 CONFIG_SPL_NAND_DRIVERS 3037 SPL uses normal NAND drivers, not minimal drivers. 3038 3039 CONFIG_SPL_NAND_ECC 3040 Include standard software ECC in the SPL 3041 3042 CONFIG_SPL_NAND_SIMPLE 3043 Support for NAND boot using simple NAND drivers that 3044 expose the cmd_ctrl() interface. 3045 3046 CONFIG_SPL_UBI 3047 Support for a lightweight UBI (fastmap) scanner and 3048 loader 3049 3050 CONFIG_SPL_NAND_RAW_ONLY 3051 Support to boot only raw u-boot.bin images. Use this only 3052 if you need to save space. 3053 3054 CONFIG_SPL_COMMON_INIT_DDR 3055 Set for common ddr init with serial presence detect in 3056 SPL binary. 3057 3058 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3059 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3060 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3061 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3062 CONFIG_SYS_NAND_ECCBYTES 3063 Defines the size and behavior of the NAND that SPL uses 3064 to read U-Boot 3065 3066 CONFIG_SPL_NAND_BOOT 3067 Add support NAND boot 3068 3069 CONFIG_SYS_NAND_U_BOOT_OFFS 3070 Location in NAND to read U-Boot from 3071 3072 CONFIG_SYS_NAND_U_BOOT_DST 3073 Location in memory to load U-Boot to 3074 3075 CONFIG_SYS_NAND_U_BOOT_SIZE 3076 Size of image to load 3077 3078 CONFIG_SYS_NAND_U_BOOT_START 3079 Entry point in loaded image to jump to 3080 3081 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3082 Define this if you need to first read the OOB and then the 3083 data. This is used, for example, on davinci platforms. 3084 3085 CONFIG_SPL_OMAP3_ID_NAND 3086 Support for an OMAP3-specific set of functions to return the 3087 ID and MFR of the first attached NAND chip, if present. 3088 3089 CONFIG_SPL_RAM_DEVICE 3090 Support for running image already present in ram, in SPL binary 3091 3092 CONFIG_SPL_PAD_TO 3093 Image offset to which the SPL should be padded before appending 3094 the SPL payload. By default, this is defined as 3095 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3096 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3097 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3098 3099 CONFIG_SPL_TARGET 3100 Final target image containing SPL and payload. Some SPLs 3101 use an arch-specific makefile fragment instead, for 3102 example if more than one image needs to be produced. 3103 3104 CONFIG_FIT_SPL_PRINT 3105 Printing information about a FIT image adds quite a bit of 3106 code to SPL. So this is normally disabled in SPL. Use this 3107 option to re-enable it. This will affect the output of the 3108 bootm command when booting a FIT image. 3109 3110- TPL framework 3111 CONFIG_TPL 3112 Enable building of TPL globally. 3113 3114 CONFIG_TPL_PAD_TO 3115 Image offset to which the TPL should be padded before appending 3116 the TPL payload. By default, this is defined as 3117 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3118 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3119 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3120 3121- Interrupt support (PPC): 3122 3123 There are common interrupt_init() and timer_interrupt() 3124 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3125 for CPU specific initialization. interrupt_init_cpu() 3126 should set decrementer_count to appropriate value. If 3127 CPU resets decrementer automatically after interrupt 3128 (ppc4xx) it should set decrementer_count to zero. 3129 timer_interrupt() calls timer_interrupt_cpu() for CPU 3130 specific handling. If board has watchdog / status_led 3131 / other_activity_monitor it works automatically from 3132 general timer_interrupt(). 3133 3134 3135Board initialization settings: 3136------------------------------ 3137 3138During Initialization u-boot calls a number of board specific functions 3139to allow the preparation of board specific prerequisites, e.g. pin setup 3140before drivers are initialized. To enable these callbacks the 3141following configuration macros have to be defined. Currently this is 3142architecture specific, so please check arch/your_architecture/lib/board.c 3143typically in board_init_f() and board_init_r(). 3144 3145- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3146- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3147- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3148- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3149 3150Configuration Settings: 3151----------------------- 3152 3153- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3154 Optionally it can be defined to support 64-bit memory commands. 3155 3156- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3157 undefine this when you're short of memory. 3158 3159- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3160 width of the commands listed in the 'help' command output. 3161 3162- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3163 prompt for user input. 3164 3165- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3166 3167- CONFIG_SYS_PBSIZE: Buffer size for Console output 3168 3169- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3170 3171- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3172 the application (usually a Linux kernel) when it is 3173 booted 3174 3175- CONFIG_SYS_BAUDRATE_TABLE: 3176 List of legal baudrate settings for this board. 3177 3178- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3179 Begin and End addresses of the area used by the 3180 simple memory test. 3181 3182- CONFIG_SYS_ALT_MEMTEST: 3183 Enable an alternate, more extensive memory test. 3184 3185- CONFIG_SYS_MEMTEST_SCRATCH: 3186 Scratch address used by the alternate memory test 3187 You only need to set this if address zero isn't writeable 3188 3189- CONFIG_SYS_MEM_RESERVE_SECURE 3190 Only implemented for ARMv8 for now. 3191 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3192 is substracted from total RAM and won't be reported to OS. 3193 This memory can be used as secure memory. A variable 3194 gd->arch.secure_ram is used to track the location. In systems 3195 the RAM base is not zero, or RAM is divided into banks, 3196 this variable needs to be recalcuated to get the address. 3197 3198- CONFIG_SYS_MEM_TOP_HIDE: 3199 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3200 this specified memory area will get subtracted from the top 3201 (end) of RAM and won't get "touched" at all by U-Boot. By 3202 fixing up gd->ram_size the Linux kernel should gets passed 3203 the now "corrected" memory size and won't touch it either. 3204 This should work for arch/ppc and arch/powerpc. Only Linux 3205 board ports in arch/powerpc with bootwrapper support that 3206 recalculate the memory size from the SDRAM controller setup 3207 will have to get fixed in Linux additionally. 3208 3209 This option can be used as a workaround for the 440EPx/GRx 3210 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3211 be touched. 3212 3213 WARNING: Please make sure that this value is a multiple of 3214 the Linux page size (normally 4k). If this is not the case, 3215 then the end address of the Linux memory will be located at a 3216 non page size aligned address and this could cause major 3217 problems. 3218 3219- CONFIG_SYS_LOADS_BAUD_CHANGE: 3220 Enable temporary baudrate change while serial download 3221 3222- CONFIG_SYS_SDRAM_BASE: 3223 Physical start address of SDRAM. _Must_ be 0 here. 3224 3225- CONFIG_SYS_FLASH_BASE: 3226 Physical start address of Flash memory. 3227 3228- CONFIG_SYS_MONITOR_BASE: 3229 Physical start address of boot monitor code (set by 3230 make config files to be same as the text base address 3231 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3232 CONFIG_SYS_FLASH_BASE when booting from flash. 3233 3234- CONFIG_SYS_MONITOR_LEN: 3235 Size of memory reserved for monitor code, used to 3236 determine _at_compile_time_ (!) if the environment is 3237 embedded within the U-Boot image, or in a separate 3238 flash sector. 3239 3240- CONFIG_SYS_MALLOC_LEN: 3241 Size of DRAM reserved for malloc() use. 3242 3243- CONFIG_SYS_MALLOC_F_LEN 3244 Size of the malloc() pool for use before relocation. If 3245 this is defined, then a very simple malloc() implementation 3246 will become available before relocation. The address is just 3247 below the global data, and the stack is moved down to make 3248 space. 3249 3250 This feature allocates regions with increasing addresses 3251 within the region. calloc() is supported, but realloc() 3252 is not available. free() is supported but does nothing. 3253 The memory will be freed (or in fact just forgotten) when 3254 U-Boot relocates itself. 3255 3256- CONFIG_SYS_MALLOC_SIMPLE 3257 Provides a simple and small malloc() and calloc() for those 3258 boards which do not use the full malloc in SPL (which is 3259 enabled with CONFIG_SYS_SPL_MALLOC_START). 3260 3261- CONFIG_SYS_NONCACHED_MEMORY: 3262 Size of non-cached memory area. This area of memory will be 3263 typically located right below the malloc() area and mapped 3264 uncached in the MMU. This is useful for drivers that would 3265 otherwise require a lot of explicit cache maintenance. For 3266 some drivers it's also impossible to properly maintain the 3267 cache. For example if the regions that need to be flushed 3268 are not a multiple of the cache-line size, *and* padding 3269 cannot be allocated between the regions to align them (i.e. 3270 if the HW requires a contiguous array of regions, and the 3271 size of each region is not cache-aligned), then a flush of 3272 one region may result in overwriting data that hardware has 3273 written to another region in the same cache-line. This can 3274 happen for example in network drivers where descriptors for 3275 buffers are typically smaller than the CPU cache-line (e.g. 3276 16 bytes vs. 32 or 64 bytes). 3277 3278 Non-cached memory is only supported on 32-bit ARM at present. 3279 3280- CONFIG_SYS_BOOTM_LEN: 3281 Normally compressed uImages are limited to an 3282 uncompressed size of 8 MBytes. If this is not enough, 3283 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3284 to adjust this setting to your needs. 3285 3286- CONFIG_SYS_BOOTMAPSZ: 3287 Maximum size of memory mapped by the startup code of 3288 the Linux kernel; all data that must be processed by 3289 the Linux kernel (bd_info, boot arguments, FDT blob if 3290 used) must be put below this limit, unless "bootm_low" 3291 environment variable is defined and non-zero. In such case 3292 all data for the Linux kernel must be between "bootm_low" 3293 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3294 variable "bootm_mapsize" will override the value of 3295 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3296 then the value in "bootm_size" will be used instead. 3297 3298- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3299 Enable initrd_high functionality. If defined then the 3300 initrd_high feature is enabled and the bootm ramdisk subcommand 3301 is enabled. 3302 3303- CONFIG_SYS_BOOT_GET_CMDLINE: 3304 Enables allocating and saving kernel cmdline in space between 3305 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3306 3307- CONFIG_SYS_BOOT_GET_KBD: 3308 Enables allocating and saving a kernel copy of the bd_info in 3309 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3310 3311- CONFIG_SYS_MAX_FLASH_BANKS: 3312 Max number of Flash memory banks 3313 3314- CONFIG_SYS_MAX_FLASH_SECT: 3315 Max number of sectors on a Flash chip 3316 3317- CONFIG_SYS_FLASH_ERASE_TOUT: 3318 Timeout for Flash erase operations (in ms) 3319 3320- CONFIG_SYS_FLASH_WRITE_TOUT: 3321 Timeout for Flash write operations (in ms) 3322 3323- CONFIG_SYS_FLASH_LOCK_TOUT 3324 Timeout for Flash set sector lock bit operation (in ms) 3325 3326- CONFIG_SYS_FLASH_UNLOCK_TOUT 3327 Timeout for Flash clear lock bits operation (in ms) 3328 3329- CONFIG_SYS_FLASH_PROTECTION 3330 If defined, hardware flash sectors protection is used 3331 instead of U-Boot software protection. 3332 3333- CONFIG_SYS_DIRECT_FLASH_TFTP: 3334 3335 Enable TFTP transfers directly to flash memory; 3336 without this option such a download has to be 3337 performed in two steps: (1) download to RAM, and (2) 3338 copy from RAM to flash. 3339 3340 The two-step approach is usually more reliable, since 3341 you can check if the download worked before you erase 3342 the flash, but in some situations (when system RAM is 3343 too limited to allow for a temporary copy of the 3344 downloaded image) this option may be very useful. 3345 3346- CONFIG_SYS_FLASH_CFI: 3347 Define if the flash driver uses extra elements in the 3348 common flash structure for storing flash geometry. 3349 3350- CONFIG_FLASH_CFI_DRIVER 3351 This option also enables the building of the cfi_flash driver 3352 in the drivers directory 3353 3354- CONFIG_FLASH_CFI_MTD 3355 This option enables the building of the cfi_mtd driver 3356 in the drivers directory. The driver exports CFI flash 3357 to the MTD layer. 3358 3359- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3360 Use buffered writes to flash. 3361 3362- CONFIG_FLASH_SPANSION_S29WS_N 3363 s29ws-n MirrorBit flash has non-standard addresses for buffered 3364 write commands. 3365 3366- CONFIG_SYS_FLASH_QUIET_TEST 3367 If this option is defined, the common CFI flash doesn't 3368 print it's warning upon not recognized FLASH banks. This 3369 is useful, if some of the configured banks are only 3370 optionally available. 3371 3372- CONFIG_FLASH_SHOW_PROGRESS 3373 If defined (must be an integer), print out countdown 3374 digits and dots. Recommended value: 45 (9..1) for 80 3375 column displays, 15 (3..1) for 40 column displays. 3376 3377- CONFIG_FLASH_VERIFY 3378 If defined, the content of the flash (destination) is compared 3379 against the source after the write operation. An error message 3380 will be printed when the contents are not identical. 3381 Please note that this option is useless in nearly all cases, 3382 since such flash programming errors usually are detected earlier 3383 while unprotecting/erasing/programming. Please only enable 3384 this option if you really know what you are doing. 3385 3386- CONFIG_SYS_RX_ETH_BUFFER: 3387 Defines the number of Ethernet receive buffers. On some 3388 Ethernet controllers it is recommended to set this value 3389 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3390 buffers can be full shortly after enabling the interface 3391 on high Ethernet traffic. 3392 Defaults to 4 if not defined. 3393 3394- CONFIG_ENV_MAX_ENTRIES 3395 3396 Maximum number of entries in the hash table that is used 3397 internally to store the environment settings. The default 3398 setting is supposed to be generous and should work in most 3399 cases. This setting can be used to tune behaviour; see 3400 lib/hashtable.c for details. 3401 3402- CONFIG_ENV_FLAGS_LIST_DEFAULT 3403- CONFIG_ENV_FLAGS_LIST_STATIC 3404 Enable validation of the values given to environment variables when 3405 calling env set. Variables can be restricted to only decimal, 3406 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3407 the variables can also be restricted to IP address or MAC address. 3408 3409 The format of the list is: 3410 type_attribute = [s|d|x|b|i|m] 3411 access_attribute = [a|r|o|c] 3412 attributes = type_attribute[access_attribute] 3413 entry = variable_name[:attributes] 3414 list = entry[,list] 3415 3416 The type attributes are: 3417 s - String (default) 3418 d - Decimal 3419 x - Hexadecimal 3420 b - Boolean ([1yYtT|0nNfF]) 3421 i - IP address 3422 m - MAC address 3423 3424 The access attributes are: 3425 a - Any (default) 3426 r - Read-only 3427 o - Write-once 3428 c - Change-default 3429 3430 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3431 Define this to a list (string) to define the ".flags" 3432 environment variable in the default or embedded environment. 3433 3434 - CONFIG_ENV_FLAGS_LIST_STATIC 3435 Define this to a list (string) to define validation that 3436 should be done if an entry is not found in the ".flags" 3437 environment variable. To override a setting in the static 3438 list, simply add an entry for the same variable name to the 3439 ".flags" variable. 3440 3441 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3442 regular expression. This allows multiple variables to define the same 3443 flags without explicitly listing them for each variable. 3444 3445- CONFIG_ENV_ACCESS_IGNORE_FORCE 3446 If defined, don't allow the -f switch to env set override variable 3447 access flags. 3448 3449- CONFIG_USE_STDINT 3450 If stdint.h is available with your toolchain you can define this 3451 option to enable it. You can provide option 'USE_STDINT=1' when 3452 building U-Boot to enable this. 3453 3454The following definitions that deal with the placement and management 3455of environment data (variable area); in general, we support the 3456following configurations: 3457 3458- CONFIG_BUILD_ENVCRC: 3459 3460 Builds up envcrc with the target environment so that external utils 3461 may easily extract it and embed it in final U-Boot images. 3462 3463- CONFIG_ENV_IS_IN_FLASH: 3464 3465 Define this if the environment is in flash memory. 3466 3467 a) The environment occupies one whole flash sector, which is 3468 "embedded" in the text segment with the U-Boot code. This 3469 happens usually with "bottom boot sector" or "top boot 3470 sector" type flash chips, which have several smaller 3471 sectors at the start or the end. For instance, such a 3472 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3473 such a case you would place the environment in one of the 3474 4 kB sectors - with U-Boot code before and after it. With 3475 "top boot sector" type flash chips, you would put the 3476 environment in one of the last sectors, leaving a gap 3477 between U-Boot and the environment. 3478 3479 - CONFIG_ENV_OFFSET: 3480 3481 Offset of environment data (variable area) to the 3482 beginning of flash memory; for instance, with bottom boot 3483 type flash chips the second sector can be used: the offset 3484 for this sector is given here. 3485 3486 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3487 3488 - CONFIG_ENV_ADDR: 3489 3490 This is just another way to specify the start address of 3491 the flash sector containing the environment (instead of 3492 CONFIG_ENV_OFFSET). 3493 3494 - CONFIG_ENV_SECT_SIZE: 3495 3496 Size of the sector containing the environment. 3497 3498 3499 b) Sometimes flash chips have few, equal sized, BIG sectors. 3500 In such a case you don't want to spend a whole sector for 3501 the environment. 3502 3503 - CONFIG_ENV_SIZE: 3504 3505 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3506 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3507 of this flash sector for the environment. This saves 3508 memory for the RAM copy of the environment. 3509 3510 It may also save flash memory if you decide to use this 3511 when your environment is "embedded" within U-Boot code, 3512 since then the remainder of the flash sector could be used 3513 for U-Boot code. It should be pointed out that this is 3514 STRONGLY DISCOURAGED from a robustness point of view: 3515 updating the environment in flash makes it always 3516 necessary to erase the WHOLE sector. If something goes 3517 wrong before the contents has been restored from a copy in 3518 RAM, your target system will be dead. 3519 3520 - CONFIG_ENV_ADDR_REDUND 3521 CONFIG_ENV_SIZE_REDUND 3522 3523 These settings describe a second storage area used to hold 3524 a redundant copy of the environment data, so that there is 3525 a valid backup copy in case there is a power failure during 3526 a "saveenv" operation. 3527 3528BE CAREFUL! Any changes to the flash layout, and some changes to the 3529source code will make it necessary to adapt <board>/u-boot.lds* 3530accordingly! 3531 3532 3533- CONFIG_ENV_IS_IN_NVRAM: 3534 3535 Define this if you have some non-volatile memory device 3536 (NVRAM, battery buffered SRAM) which you want to use for the 3537 environment. 3538 3539 - CONFIG_ENV_ADDR: 3540 - CONFIG_ENV_SIZE: 3541 3542 These two #defines are used to determine the memory area you 3543 want to use for environment. It is assumed that this memory 3544 can just be read and written to, without any special 3545 provision. 3546 3547BE CAREFUL! The first access to the environment happens quite early 3548in U-Boot initialization (when we try to get the setting of for the 3549console baudrate). You *MUST* have mapped your NVRAM area then, or 3550U-Boot will hang. 3551 3552Please note that even with NVRAM we still use a copy of the 3553environment in RAM: we could work on NVRAM directly, but we want to 3554keep settings there always unmodified except somebody uses "saveenv" 3555to save the current settings. 3556 3557 3558- CONFIG_ENV_IS_IN_EEPROM: 3559 3560 Use this if you have an EEPROM or similar serial access 3561 device and a driver for it. 3562 3563 - CONFIG_ENV_OFFSET: 3564 - CONFIG_ENV_SIZE: 3565 3566 These two #defines specify the offset and size of the 3567 environment area within the total memory of your EEPROM. 3568 3569 - CONFIG_SYS_I2C_EEPROM_ADDR: 3570 If defined, specified the chip address of the EEPROM device. 3571 The default address is zero. 3572 3573 - CONFIG_SYS_I2C_EEPROM_BUS: 3574 If defined, specified the i2c bus of the EEPROM device. 3575 3576 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3577 If defined, the number of bits used to address bytes in a 3578 single page in the EEPROM device. A 64 byte page, for example 3579 would require six bits. 3580 3581 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3582 If defined, the number of milliseconds to delay between 3583 page writes. The default is zero milliseconds. 3584 3585 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3586 The length in bytes of the EEPROM memory array address. Note 3587 that this is NOT the chip address length! 3588 3589 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3590 EEPROM chips that implement "address overflow" are ones 3591 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3592 address and the extra bits end up in the "chip address" bit 3593 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3594 byte chips. 3595 3596 Note that we consider the length of the address field to 3597 still be one byte because the extra address bits are hidden 3598 in the chip address. 3599 3600 - CONFIG_SYS_EEPROM_SIZE: 3601 The size in bytes of the EEPROM device. 3602 3603 - CONFIG_ENV_EEPROM_IS_ON_I2C 3604 define this, if you have I2C and SPI activated, and your 3605 EEPROM, which holds the environment, is on the I2C bus. 3606 3607 - CONFIG_I2C_ENV_EEPROM_BUS 3608 if you have an Environment on an EEPROM reached over 3609 I2C muxes, you can define here, how to reach this 3610 EEPROM. For example: 3611 3612 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3613 3614 EEPROM which holds the environment, is reached over 3615 a pca9547 i2c mux with address 0x70, channel 3. 3616 3617- CONFIG_ENV_IS_IN_DATAFLASH: 3618 3619 Define this if you have a DataFlash memory device which you 3620 want to use for the environment. 3621 3622 - CONFIG_ENV_OFFSET: 3623 - CONFIG_ENV_ADDR: 3624 - CONFIG_ENV_SIZE: 3625 3626 These three #defines specify the offset and size of the 3627 environment area within the total memory of your DataFlash placed 3628 at the specified address. 3629 3630- CONFIG_ENV_IS_IN_SPI_FLASH: 3631 3632 Define this if you have a SPI Flash memory device which you 3633 want to use for the environment. 3634 3635 - CONFIG_ENV_OFFSET: 3636 - CONFIG_ENV_SIZE: 3637 3638 These two #defines specify the offset and size of the 3639 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3640 aligned to an erase sector boundary. 3641 3642 - CONFIG_ENV_SECT_SIZE: 3643 3644 Define the SPI flash's sector size. 3645 3646 - CONFIG_ENV_OFFSET_REDUND (optional): 3647 3648 This setting describes a second storage area of CONFIG_ENV_SIZE 3649 size used to hold a redundant copy of the environment data, so 3650 that there is a valid backup copy in case there is a power failure 3651 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3652 aligned to an erase sector boundary. 3653 3654 - CONFIG_ENV_SPI_BUS (optional): 3655 - CONFIG_ENV_SPI_CS (optional): 3656 3657 Define the SPI bus and chip select. If not defined they will be 0. 3658 3659 - CONFIG_ENV_SPI_MAX_HZ (optional): 3660 3661 Define the SPI max work clock. If not defined then use 1MHz. 3662 3663 - CONFIG_ENV_SPI_MODE (optional): 3664 3665 Define the SPI work mode. If not defined then use SPI_MODE_3. 3666 3667- CONFIG_ENV_IS_IN_REMOTE: 3668 3669 Define this if you have a remote memory space which you 3670 want to use for the local device's environment. 3671 3672 - CONFIG_ENV_ADDR: 3673 - CONFIG_ENV_SIZE: 3674 3675 These two #defines specify the address and size of the 3676 environment area within the remote memory space. The 3677 local device can get the environment from remote memory 3678 space by SRIO or PCIE links. 3679 3680BE CAREFUL! For some special cases, the local device can not use 3681"saveenv" command. For example, the local device will get the 3682environment stored in a remote NOR flash by SRIO or PCIE link, 3683but it can not erase, write this NOR flash by SRIO or PCIE interface. 3684 3685- CONFIG_ENV_IS_IN_NAND: 3686 3687 Define this if you have a NAND device which you want to use 3688 for the environment. 3689 3690 - CONFIG_ENV_OFFSET: 3691 - CONFIG_ENV_SIZE: 3692 3693 These two #defines specify the offset and size of the environment 3694 area within the first NAND device. CONFIG_ENV_OFFSET must be 3695 aligned to an erase block boundary. 3696 3697 - CONFIG_ENV_OFFSET_REDUND (optional): 3698 3699 This setting describes a second storage area of CONFIG_ENV_SIZE 3700 size used to hold a redundant copy of the environment data, so 3701 that there is a valid backup copy in case there is a power failure 3702 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3703 aligned to an erase block boundary. 3704 3705 - CONFIG_ENV_RANGE (optional): 3706 3707 Specifies the length of the region in which the environment 3708 can be written. This should be a multiple of the NAND device's 3709 block size. Specifying a range with more erase blocks than 3710 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3711 the range to be avoided. 3712 3713 - CONFIG_ENV_OFFSET_OOB (optional): 3714 3715 Enables support for dynamically retrieving the offset of the 3716 environment from block zero's out-of-band data. The 3717 "nand env.oob" command can be used to record this offset. 3718 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3719 using CONFIG_ENV_OFFSET_OOB. 3720 3721- CONFIG_NAND_ENV_DST 3722 3723 Defines address in RAM to which the nand_spl code should copy the 3724 environment. If redundant environment is used, it will be copied to 3725 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3726 3727- CONFIG_ENV_IS_IN_UBI: 3728 3729 Define this if you have an UBI volume that you want to use for the 3730 environment. This has the benefit of wear-leveling the environment 3731 accesses, which is important on NAND. 3732 3733 - CONFIG_ENV_UBI_PART: 3734 3735 Define this to a string that is the mtd partition containing the UBI. 3736 3737 - CONFIG_ENV_UBI_VOLUME: 3738 3739 Define this to the name of the volume that you want to store the 3740 environment in. 3741 3742 - CONFIG_ENV_UBI_VOLUME_REDUND: 3743 3744 Define this to the name of another volume to store a second copy of 3745 the environment in. This will enable redundant environments in UBI. 3746 It is assumed that both volumes are in the same MTD partition. 3747 3748 - CONFIG_UBI_SILENCE_MSG 3749 - CONFIG_UBIFS_SILENCE_MSG 3750 3751 You will probably want to define these to avoid a really noisy system 3752 when storing the env in UBI. 3753 3754- CONFIG_ENV_IS_IN_FAT: 3755 Define this if you want to use the FAT file system for the environment. 3756 3757 - FAT_ENV_INTERFACE: 3758 3759 Define this to a string that is the name of the block device. 3760 3761 - FAT_ENV_DEVICE_AND_PART: 3762 3763 Define this to a string to specify the partition of the device. It can 3764 be as following: 3765 3766 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3767 - "D:P": device D partition P. Error occurs if device D has no 3768 partition table. 3769 - "D:0": device D. 3770 - "D" or "D:": device D partition 1 if device D has partition 3771 table, or the whole device D if has no partition 3772 table. 3773 - "D:auto": first partition in device D with bootable flag set. 3774 If none, first valid partition in device D. If no 3775 partition table then means device D. 3776 3777 - FAT_ENV_FILE: 3778 3779 It's a string of the FAT file name. This file use to store the 3780 environment. 3781 3782 - CONFIG_FAT_WRITE: 3783 This must be enabled. Otherwise it cannot save the environment file. 3784 3785- CONFIG_ENV_IS_IN_MMC: 3786 3787 Define this if you have an MMC device which you want to use for the 3788 environment. 3789 3790 - CONFIG_SYS_MMC_ENV_DEV: 3791 3792 Specifies which MMC device the environment is stored in. 3793 3794 - CONFIG_SYS_MMC_ENV_PART (optional): 3795 3796 Specifies which MMC partition the environment is stored in. If not 3797 set, defaults to partition 0, the user area. Common values might be 3798 1 (first MMC boot partition), 2 (second MMC boot partition). 3799 3800 - CONFIG_ENV_OFFSET: 3801 - CONFIG_ENV_SIZE: 3802 3803 These two #defines specify the offset and size of the environment 3804 area within the specified MMC device. 3805 3806 If offset is positive (the usual case), it is treated as relative to 3807 the start of the MMC partition. If offset is negative, it is treated 3808 as relative to the end of the MMC partition. This can be useful if 3809 your board may be fitted with different MMC devices, which have 3810 different sizes for the MMC partitions, and you always want the 3811 environment placed at the very end of the partition, to leave the 3812 maximum possible space before it, to store other data. 3813 3814 These two values are in units of bytes, but must be aligned to an 3815 MMC sector boundary. 3816 3817 - CONFIG_ENV_OFFSET_REDUND (optional): 3818 3819 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3820 hold a redundant copy of the environment data. This provides a 3821 valid backup copy in case the other copy is corrupted, e.g. due 3822 to a power failure during a "saveenv" operation. 3823 3824 This value may also be positive or negative; this is handled in the 3825 same way as CONFIG_ENV_OFFSET. 3826 3827 This value is also in units of bytes, but must also be aligned to 3828 an MMC sector boundary. 3829 3830 - CONFIG_ENV_SIZE_REDUND (optional): 3831 3832 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3833 set. If this value is set, it must be set to the same value as 3834 CONFIG_ENV_SIZE. 3835 3836Please note that the environment is read-only until the monitor 3837has been relocated to RAM and a RAM copy of the environment has been 3838created; also, when using EEPROM you will have to use getenv_f() 3839until then to read environment variables. 3840 3841The environment is protected by a CRC32 checksum. Before the monitor 3842is relocated into RAM, as a result of a bad CRC you will be working 3843with the compiled-in default environment - *silently*!!! [This is 3844necessary, because the first environment variable we need is the 3845"baudrate" setting for the console - if we have a bad CRC, we don't 3846have any device yet where we could complain.] 3847 3848Note: once the monitor has been relocated, then it will complain if 3849the default environment is used; a new CRC is computed as soon as you 3850use the "saveenv" command to store a valid environment. 3851 3852- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3853 Echo the inverted Ethernet link state to the fault LED. 3854 3855 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3856 also needs to be defined. 3857 3858- CONFIG_SYS_FAULT_MII_ADDR: 3859 MII address of the PHY to check for the Ethernet link state. 3860 3861- CONFIG_NS16550_MIN_FUNCTIONS: 3862 Define this if you desire to only have use of the NS16550_init 3863 and NS16550_putc functions for the serial driver located at 3864 drivers/serial/ns16550.c. This option is useful for saving 3865 space for already greatly restricted images, including but not 3866 limited to NAND_SPL configurations. 3867 3868- CONFIG_DISPLAY_BOARDINFO 3869 Display information about the board that U-Boot is running on 3870 when U-Boot starts up. The board function checkboard() is called 3871 to do this. 3872 3873- CONFIG_DISPLAY_BOARDINFO_LATE 3874 Similar to the previous option, but display this information 3875 later, once stdio is running and output goes to the LCD, if 3876 present. 3877 3878- CONFIG_BOARD_SIZE_LIMIT: 3879 Maximum size of the U-Boot image. When defined, the 3880 build system checks that the actual size does not 3881 exceed it. 3882 3883Low Level (hardware related) configuration options: 3884--------------------------------------------------- 3885 3886- CONFIG_SYS_CACHELINE_SIZE: 3887 Cache Line Size of the CPU. 3888 3889- CONFIG_SYS_CCSRBAR_DEFAULT: 3890 Default (power-on reset) physical address of CCSR on Freescale 3891 PowerPC SOCs. 3892 3893- CONFIG_SYS_CCSRBAR: 3894 Virtual address of CCSR. On a 32-bit build, this is typically 3895 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3896 3897- CONFIG_SYS_CCSRBAR_PHYS: 3898 Physical address of CCSR. CCSR can be relocated to a new 3899 physical address, if desired. In this case, this macro should 3900 be set to that address. Otherwise, it should be set to the 3901 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3902 is typically relocated on 36-bit builds. It is recommended 3903 that this macro be defined via the _HIGH and _LOW macros: 3904 3905 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3906 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3907 3908- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3909 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3910 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3911 used in assembly code, so it must not contain typecasts or 3912 integer size suffixes (e.g. "ULL"). 3913 3914- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3915 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3916 used in assembly code, so it must not contain typecasts or 3917 integer size suffixes (e.g. "ULL"). 3918 3919- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3920 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3921 forced to a value that ensures that CCSR is not relocated. 3922 3923- Floppy Disk Support: 3924 CONFIG_SYS_FDC_DRIVE_NUMBER 3925 3926 the default drive number (default value 0) 3927 3928 CONFIG_SYS_ISA_IO_STRIDE 3929 3930 defines the spacing between FDC chipset registers 3931 (default value 1) 3932 3933 CONFIG_SYS_ISA_IO_OFFSET 3934 3935 defines the offset of register from address. It 3936 depends on which part of the data bus is connected to 3937 the FDC chipset. (default value 0) 3938 3939 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3940 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3941 default value. 3942 3943 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3944 fdc_hw_init() is called at the beginning of the FDC 3945 setup. fdc_hw_init() must be provided by the board 3946 source code. It is used to make hardware-dependent 3947 initializations. 3948 3949- CONFIG_IDE_AHB: 3950 Most IDE controllers were designed to be connected with PCI 3951 interface. Only few of them were designed for AHB interface. 3952 When software is doing ATA command and data transfer to 3953 IDE devices through IDE-AHB controller, some additional 3954 registers accessing to these kind of IDE-AHB controller 3955 is required. 3956 3957- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3958 DO NOT CHANGE unless you know exactly what you're 3959 doing! (11-4) [MPC8xx systems only] 3960 3961- CONFIG_SYS_INIT_RAM_ADDR: 3962 3963 Start address of memory area that can be used for 3964 initial data and stack; please note that this must be 3965 writable memory that is working WITHOUT special 3966 initialization, i. e. you CANNOT use normal RAM which 3967 will become available only after programming the 3968 memory controller and running certain initialization 3969 sequences. 3970 3971 U-Boot uses the following memory types: 3972 - MPC8xx: IMMR (internal memory of the CPU) 3973 3974- CONFIG_SYS_GBL_DATA_OFFSET: 3975 3976 Offset of the initial data structure in the memory 3977 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3978 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3979 data is located at the end of the available space 3980 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3981 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3982 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3983 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3984 3985 Note: 3986 On the MPC824X (or other systems that use the data 3987 cache for initial memory) the address chosen for 3988 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3989 point to an otherwise UNUSED address space between 3990 the top of RAM and the start of the PCI space. 3991 3992- CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6) 3993 3994- CONFIG_SYS_SYPCR: System Protection Control (11-9) 3995 3996- CONFIG_SYS_TBSCR: Time Base Status and Control (11-26) 3997 3998- CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31) 3999 4000- CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30) 4001 4002- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 4003 4004- CONFIG_SYS_OR_TIMING_SDRAM: 4005 SDRAM timing 4006 4007- CONFIG_SYS_MAMR_PTA: 4008 periodic timer for refresh 4009 4010- CONFIG_SYS_DER: Debug Event Register (37-47) 4011 4012- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 4013 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 4014 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 4015 CONFIG_SYS_BR1_PRELIM: 4016 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 4017 4018- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 4019 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 4020 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 4021 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 4022 4023- CONFIG_PCI_ENUM_ONLY 4024 Only scan through and get the devices on the buses. 4025 Don't do any setup work, presumably because someone or 4026 something has already done it, and we don't need to do it 4027 a second time. Useful for platforms that are pre-booted 4028 by coreboot or similar. 4029 4030- CONFIG_PCI_INDIRECT_BRIDGE: 4031 Enable support for indirect PCI bridges. 4032 4033- CONFIG_SYS_SRIO: 4034 Chip has SRIO or not 4035 4036- CONFIG_SRIO1: 4037 Board has SRIO 1 port available 4038 4039- CONFIG_SRIO2: 4040 Board has SRIO 2 port available 4041 4042- CONFIG_SRIO_PCIE_BOOT_MASTER 4043 Board can support master function for Boot from SRIO and PCIE 4044 4045- CONFIG_SYS_SRIOn_MEM_VIRT: 4046 Virtual Address of SRIO port 'n' memory region 4047 4048- CONFIG_SYS_SRIOn_MEM_PHYS: 4049 Physical Address of SRIO port 'n' memory region 4050 4051- CONFIG_SYS_SRIOn_MEM_SIZE: 4052 Size of SRIO port 'n' memory region 4053 4054- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4055 Defined to tell the NAND controller that the NAND chip is using 4056 a 16 bit bus. 4057 Not all NAND drivers use this symbol. 4058 Example of drivers that use it: 4059 - drivers/mtd/nand/ndfc.c 4060 - drivers/mtd/nand/mxc_nand.c 4061 4062- CONFIG_SYS_NDFC_EBC0_CFG 4063 Sets the EBC0_CFG register for the NDFC. If not defined 4064 a default value will be used. 4065 4066- CONFIG_SPD_EEPROM 4067 Get DDR timing information from an I2C EEPROM. Common 4068 with pluggable memory modules such as SODIMMs 4069 4070 SPD_EEPROM_ADDRESS 4071 I2C address of the SPD EEPROM 4072 4073- CONFIG_SYS_SPD_BUS_NUM 4074 If SPD EEPROM is on an I2C bus other than the first 4075 one, specify here. Note that the value must resolve 4076 to something your driver can deal with. 4077 4078- CONFIG_SYS_DDR_RAW_TIMING 4079 Get DDR timing information from other than SPD. Common with 4080 soldered DDR chips onboard without SPD. DDR raw timing 4081 parameters are extracted from datasheet and hard-coded into 4082 header files or board specific files. 4083 4084- CONFIG_FSL_DDR_INTERACTIVE 4085 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4086 4087- CONFIG_FSL_DDR_SYNC_REFRESH 4088 Enable sync of refresh for multiple controllers. 4089 4090- CONFIG_FSL_DDR_BIST 4091 Enable built-in memory test for Freescale DDR controllers. 4092 4093- CONFIG_SYS_83XX_DDR_USES_CS0 4094 Only for 83xx systems. If specified, then DDR should 4095 be configured using CS0 and CS1 instead of CS2 and CS3. 4096 4097- CONFIG_ETHER_ON_FEC[12] 4098 Define to enable FEC[12] on a 8xx series processor. 4099 4100- CONFIG_FEC[12]_PHY 4101 Define to the hardcoded PHY address which corresponds 4102 to the given FEC; i. e. 4103 #define CONFIG_FEC1_PHY 4 4104 means that the PHY with address 4 is connected to FEC1 4105 4106 When set to -1, means to probe for first available. 4107 4108- CONFIG_FEC[12]_PHY_NORXERR 4109 The PHY does not have a RXERR line (RMII only). 4110 (so program the FEC to ignore it). 4111 4112- CONFIG_RMII 4113 Enable RMII mode for all FECs. 4114 Note that this is a global option, we can't 4115 have one FEC in standard MII mode and another in RMII mode. 4116 4117- CONFIG_CRC32_VERIFY 4118 Add a verify option to the crc32 command. 4119 The syntax is: 4120 4121 => crc32 -v <address> <count> <crc32> 4122 4123 Where address/count indicate a memory area 4124 and crc32 is the correct crc32 which the 4125 area should have. 4126 4127- CONFIG_LOOPW 4128 Add the "loopw" memory command. This only takes effect if 4129 the memory commands are activated globally (CONFIG_CMD_MEM). 4130 4131- CONFIG_MX_CYCLIC 4132 Add the "mdc" and "mwc" memory commands. These are cyclic 4133 "md/mw" commands. 4134 Examples: 4135 4136 => mdc.b 10 4 500 4137 This command will print 4 bytes (10,11,12,13) each 500 ms. 4138 4139 => mwc.l 100 12345678 10 4140 This command will write 12345678 to address 100 all 10 ms. 4141 4142 This only takes effect if the memory commands are activated 4143 globally (CONFIG_CMD_MEM). 4144 4145- CONFIG_SKIP_LOWLEVEL_INIT 4146 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4147 low level initializations (like setting up the memory 4148 controller) are omitted and/or U-Boot does not 4149 relocate itself into RAM. 4150 4151 Normally this variable MUST NOT be defined. The only 4152 exception is when U-Boot is loaded (to RAM) by some 4153 other boot loader or by a debugger which performs 4154 these initializations itself. 4155 4156- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4157 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4158 to be skipped. The normal CP15 init (such as enabling the 4159 instruction cache) is still performed. 4160 4161- CONFIG_SPL_BUILD 4162 Modifies the behaviour of start.S when compiling a loader 4163 that is executed before the actual U-Boot. E.g. when 4164 compiling a NAND SPL. 4165 4166- CONFIG_TPL_BUILD 4167 Modifies the behaviour of start.S when compiling a loader 4168 that is executed after the SPL and before the actual U-Boot. 4169 It is loaded by the SPL. 4170 4171- CONFIG_SYS_MPC85XX_NO_RESETVEC 4172 Only for 85xx systems. If this variable is specified, the section 4173 .resetvec is not kept and the section .bootpg is placed in the 4174 previous 4k of the .text section. 4175 4176- CONFIG_ARCH_MAP_SYSMEM 4177 Generally U-Boot (and in particular the md command) uses 4178 effective address. It is therefore not necessary to regard 4179 U-Boot address as virtual addresses that need to be translated 4180 to physical addresses. However, sandbox requires this, since 4181 it maintains its own little RAM buffer which contains all 4182 addressable memory. This option causes some memory accesses 4183 to be mapped through map_sysmem() / unmap_sysmem(). 4184 4185- CONFIG_X86_RESET_VECTOR 4186 If defined, the x86 reset vector code is included. This is not 4187 needed when U-Boot is running from Coreboot. 4188 4189- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4190 Enables the RTC32K OSC on AM33xx based plattforms 4191 4192- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4193 Option to disable subpage write in NAND driver 4194 driver that uses this: 4195 drivers/mtd/nand/davinci_nand.c 4196 4197Freescale QE/FMAN Firmware Support: 4198----------------------------------- 4199 4200The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4201loading of "firmware", which is encoded in the QE firmware binary format. 4202This firmware often needs to be loaded during U-Boot booting, so macros 4203are used to identify the storage device (NOR flash, SPI, etc) and the address 4204within that device. 4205 4206- CONFIG_SYS_FMAN_FW_ADDR 4207 The address in the storage device where the FMAN microcode is located. The 4208 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4209 is also specified. 4210 4211- CONFIG_SYS_QE_FW_ADDR 4212 The address in the storage device where the QE microcode is located. The 4213 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4214 is also specified. 4215 4216- CONFIG_SYS_QE_FMAN_FW_LENGTH 4217 The maximum possible size of the firmware. The firmware binary format 4218 has a field that specifies the actual size of the firmware, but it 4219 might not be possible to read any part of the firmware unless some 4220 local storage is allocated to hold the entire firmware first. 4221 4222- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4223 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4224 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4225 virtual address in NOR flash. 4226 4227- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4228 Specifies that QE/FMAN firmware is located in NAND flash. 4229 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4230 4231- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4232 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4233 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4234 4235- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4236 Specifies that QE/FMAN firmware is located in the remote (master) 4237 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4238 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4239 window->master inbound window->master LAW->the ucode address in 4240 master's memory space. 4241 4242Freescale Layerscape Management Complex Firmware Support: 4243--------------------------------------------------------- 4244The Freescale Layerscape Management Complex (MC) supports the loading of 4245"firmware". 4246This firmware often needs to be loaded during U-Boot booting, so macros 4247are used to identify the storage device (NOR flash, SPI, etc) and the address 4248within that device. 4249 4250- CONFIG_FSL_MC_ENET 4251 Enable the MC driver for Layerscape SoCs. 4252 4253Freescale Layerscape Debug Server Support: 4254------------------------------------------- 4255The Freescale Layerscape Debug Server Support supports the loading of 4256"Debug Server firmware" and triggering SP boot-rom. 4257This firmware often needs to be loaded during U-Boot booting. 4258 4259- CONFIG_SYS_MC_RSV_MEM_ALIGN 4260 Define alignment of reserved memory MC requires 4261 4262Reproducible builds 4263------------------- 4264 4265In order to achieve reproducible builds, timestamps used in the U-Boot build 4266process have to be set to a fixed value. 4267 4268This is done using the SOURCE_DATE_EPOCH environment variable. 4269SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4270option for U-Boot or an environment variable in U-Boot. 4271 4272SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4273 4274Building the Software: 4275====================== 4276 4277Building U-Boot has been tested in several native build environments 4278and in many different cross environments. Of course we cannot support 4279all possibly existing versions of cross development tools in all 4280(potentially obsolete) versions. In case of tool chain problems we 4281recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4282which is extensively used to build and test U-Boot. 4283 4284If you are not using a native environment, it is assumed that you 4285have GNU cross compiling tools available in your path. In this case, 4286you must set the environment variable CROSS_COMPILE in your shell. 4287Note that no changes to the Makefile or any other source files are 4288necessary. For example using the ELDK on a 4xx CPU, please enter: 4289 4290 $ CROSS_COMPILE=ppc_4xx- 4291 $ export CROSS_COMPILE 4292 4293Note: If you wish to generate Windows versions of the utilities in 4294 the tools directory you can use the MinGW toolchain 4295 (http://www.mingw.org). Set your HOST tools to the MinGW 4296 toolchain and execute 'make tools'. For example: 4297 4298 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4299 4300 Binaries such as tools/mkimage.exe will be created which can 4301 be executed on computers running Windows. 4302 4303U-Boot is intended to be simple to build. After installing the 4304sources you must configure U-Boot for one specific board type. This 4305is done by typing: 4306 4307 make NAME_defconfig 4308 4309where "NAME_defconfig" is the name of one of the existing configu- 4310rations; see boards.cfg for supported names. 4311 4312Note: for some board special configuration names may exist; check if 4313 additional information is available from the board vendor; for 4314 instance, the TQM823L systems are available without (standard) 4315 or with LCD support. You can select such additional "features" 4316 when choosing the configuration, i. e. 4317 4318 make TQM823L_defconfig 4319 - will configure for a plain TQM823L, i. e. no LCD support 4320 4321 make TQM823L_LCD_defconfig 4322 - will configure for a TQM823L with U-Boot console on LCD 4323 4324 etc. 4325 4326 4327Finally, type "make all", and you should get some working U-Boot 4328images ready for download to / installation on your system: 4329 4330- "u-boot.bin" is a raw binary image 4331- "u-boot" is an image in ELF binary format 4332- "u-boot.srec" is in Motorola S-Record format 4333 4334By default the build is performed locally and the objects are saved 4335in the source directory. One of the two methods can be used to change 4336this behavior and build U-Boot to some external directory: 4337 43381. Add O= to the make command line invocations: 4339 4340 make O=/tmp/build distclean 4341 make O=/tmp/build NAME_defconfig 4342 make O=/tmp/build all 4343 43442. Set environment variable KBUILD_OUTPUT to point to the desired location: 4345 4346 export KBUILD_OUTPUT=/tmp/build 4347 make distclean 4348 make NAME_defconfig 4349 make all 4350 4351Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4352variable. 4353 4354 4355Please be aware that the Makefiles assume you are using GNU make, so 4356for instance on NetBSD you might need to use "gmake" instead of 4357native "make". 4358 4359 4360If the system board that you have is not listed, then you will need 4361to port U-Boot to your hardware platform. To do this, follow these 4362steps: 4363 43641. Create a new directory to hold your board specific code. Add any 4365 files you need. In your board directory, you will need at least 4366 the "Makefile" and a "<board>.c". 43672. Create a new configuration file "include/configs/<board>.h" for 4368 your board. 43693. If you're porting U-Boot to a new CPU, then also create a new 4370 directory to hold your CPU specific code. Add any files you need. 43714. Run "make <board>_defconfig" with your new name. 43725. Type "make", and you should get a working "u-boot.srec" file 4373 to be installed on your target system. 43746. Debug and solve any problems that might arise. 4375 [Of course, this last step is much harder than it sounds.] 4376 4377 4378Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4379============================================================== 4380 4381If you have modified U-Boot sources (for instance added a new board 4382or support for new devices, a new CPU, etc.) you are expected to 4383provide feedback to the other developers. The feedback normally takes 4384the form of a "patch", i. e. a context diff against a certain (latest 4385official or latest in the git repository) version of U-Boot sources. 4386 4387But before you submit such a patch, please verify that your modifi- 4388cation did not break existing code. At least make sure that *ALL* of 4389the supported boards compile WITHOUT ANY compiler warnings. To do so, 4390just run the buildman script (tools/buildman/buildman), which will 4391configure and build U-Boot for ALL supported system. Be warned, this 4392will take a while. Please see the buildman README, or run 'buildman -H' 4393for documentation. 4394 4395 4396See also "U-Boot Porting Guide" below. 4397 4398 4399Monitor Commands - Overview: 4400============================ 4401 4402go - start application at address 'addr' 4403run - run commands in an environment variable 4404bootm - boot application image from memory 4405bootp - boot image via network using BootP/TFTP protocol 4406bootz - boot zImage from memory 4407tftpboot- boot image via network using TFTP protocol 4408 and env variables "ipaddr" and "serverip" 4409 (and eventually "gatewayip") 4410tftpput - upload a file via network using TFTP protocol 4411rarpboot- boot image via network using RARP/TFTP protocol 4412diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4413loads - load S-Record file over serial line 4414loadb - load binary file over serial line (kermit mode) 4415md - memory display 4416mm - memory modify (auto-incrementing) 4417nm - memory modify (constant address) 4418mw - memory write (fill) 4419cp - memory copy 4420cmp - memory compare 4421crc32 - checksum calculation 4422i2c - I2C sub-system 4423sspi - SPI utility commands 4424base - print or set address offset 4425printenv- print environment variables 4426setenv - set environment variables 4427saveenv - save environment variables to persistent storage 4428protect - enable or disable FLASH write protection 4429erase - erase FLASH memory 4430flinfo - print FLASH memory information 4431nand - NAND memory operations (see doc/README.nand) 4432bdinfo - print Board Info structure 4433iminfo - print header information for application image 4434coninfo - print console devices and informations 4435ide - IDE sub-system 4436loop - infinite loop on address range 4437loopw - infinite write loop on address range 4438mtest - simple RAM test 4439icache - enable or disable instruction cache 4440dcache - enable or disable data cache 4441reset - Perform RESET of the CPU 4442echo - echo args to console 4443version - print monitor version 4444help - print online help 4445? - alias for 'help' 4446 4447 4448Monitor Commands - Detailed Description: 4449======================================== 4450 4451TODO. 4452 4453For now: just type "help <command>". 4454 4455 4456Environment Variables: 4457====================== 4458 4459U-Boot supports user configuration using Environment Variables which 4460can be made persistent by saving to Flash memory. 4461 4462Environment Variables are set using "setenv", printed using 4463"printenv", and saved to Flash using "saveenv". Using "setenv" 4464without a value can be used to delete a variable from the 4465environment. As long as you don't save the environment you are 4466working with an in-memory copy. In case the Flash area containing the 4467environment is erased by accident, a default environment is provided. 4468 4469Some configuration options can be set using Environment Variables. 4470 4471List of environment variables (most likely not complete): 4472 4473 baudrate - see CONFIG_BAUDRATE 4474 4475 bootdelay - see CONFIG_BOOTDELAY 4476 4477 bootcmd - see CONFIG_BOOTCOMMAND 4478 4479 bootargs - Boot arguments when booting an RTOS image 4480 4481 bootfile - Name of the image to load with TFTP 4482 4483 bootm_low - Memory range available for image processing in the bootm 4484 command can be restricted. This variable is given as 4485 a hexadecimal number and defines lowest address allowed 4486 for use by the bootm command. See also "bootm_size" 4487 environment variable. Address defined by "bootm_low" is 4488 also the base of the initial memory mapping for the Linux 4489 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4490 bootm_mapsize. 4491 4492 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4493 This variable is given as a hexadecimal number and it 4494 defines the size of the memory region starting at base 4495 address bootm_low that is accessible by the Linux kernel 4496 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4497 as the default value if it is defined, and bootm_size is 4498 used otherwise. 4499 4500 bootm_size - Memory range available for image processing in the bootm 4501 command can be restricted. This variable is given as 4502 a hexadecimal number and defines the size of the region 4503 allowed for use by the bootm command. See also "bootm_low" 4504 environment variable. 4505 4506 updatefile - Location of the software update file on a TFTP server, used 4507 by the automatic software update feature. Please refer to 4508 documentation in doc/README.update for more details. 4509 4510 autoload - if set to "no" (any string beginning with 'n'), 4511 "bootp" will just load perform a lookup of the 4512 configuration from the BOOTP server, but not try to 4513 load any image using TFTP 4514 4515 autostart - if set to "yes", an image loaded using the "bootp", 4516 "rarpboot", "tftpboot" or "diskboot" commands will 4517 be automatically started (by internally calling 4518 "bootm") 4519 4520 If set to "no", a standalone image passed to the 4521 "bootm" command will be copied to the load address 4522 (and eventually uncompressed), but NOT be started. 4523 This can be used to load and uncompress arbitrary 4524 data. 4525 4526 fdt_high - if set this restricts the maximum address that the 4527 flattened device tree will be copied into upon boot. 4528 For example, if you have a system with 1 GB memory 4529 at physical address 0x10000000, while Linux kernel 4530 only recognizes the first 704 MB as low memory, you 4531 may need to set fdt_high as 0x3C000000 to have the 4532 device tree blob be copied to the maximum address 4533 of the 704 MB low memory, so that Linux kernel can 4534 access it during the boot procedure. 4535 4536 If this is set to the special value 0xFFFFFFFF then 4537 the fdt will not be copied at all on boot. For this 4538 to work it must reside in writable memory, have 4539 sufficient padding on the end of it for u-boot to 4540 add the information it needs into it, and the memory 4541 must be accessible by the kernel. 4542 4543 fdtcontroladdr- if set this is the address of the control flattened 4544 device tree used by U-Boot when CONFIG_OF_CONTROL is 4545 defined. 4546 4547 i2cfast - (PPC405GP|PPC405EP only) 4548 if set to 'y' configures Linux I2C driver for fast 4549 mode (400kHZ). This environment variable is used in 4550 initialization code. So, for changes to be effective 4551 it must be saved and board must be reset. 4552 4553 initrd_high - restrict positioning of initrd images: 4554 If this variable is not set, initrd images will be 4555 copied to the highest possible address in RAM; this 4556 is usually what you want since it allows for 4557 maximum initrd size. If for some reason you want to 4558 make sure that the initrd image is loaded below the 4559 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4560 variable to a value of "no" or "off" or "0". 4561 Alternatively, you can set it to a maximum upper 4562 address to use (U-Boot will still check that it 4563 does not overwrite the U-Boot stack and data). 4564 4565 For instance, when you have a system with 16 MB 4566 RAM, and want to reserve 4 MB from use by Linux, 4567 you can do this by adding "mem=12M" to the value of 4568 the "bootargs" variable. However, now you must make 4569 sure that the initrd image is placed in the first 4570 12 MB as well - this can be done with 4571 4572 setenv initrd_high 00c00000 4573 4574 If you set initrd_high to 0xFFFFFFFF, this is an 4575 indication to U-Boot that all addresses are legal 4576 for the Linux kernel, including addresses in flash 4577 memory. In this case U-Boot will NOT COPY the 4578 ramdisk at all. This may be useful to reduce the 4579 boot time on your system, but requires that this 4580 feature is supported by your Linux kernel. 4581 4582 ipaddr - IP address; needed for tftpboot command 4583 4584 loadaddr - Default load address for commands like "bootp", 4585 "rarpboot", "tftpboot", "loadb" or "diskboot" 4586 4587 loads_echo - see CONFIG_LOADS_ECHO 4588 4589 serverip - TFTP server IP address; needed for tftpboot command 4590 4591 bootretry - see CONFIG_BOOT_RETRY_TIME 4592 4593 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4594 4595 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4596 4597 ethprime - controls which interface is used first. 4598 4599 ethact - controls which interface is currently active. 4600 For example you can do the following 4601 4602 => setenv ethact FEC 4603 => ping 192.168.0.1 # traffic sent on FEC 4604 => setenv ethact SCC 4605 => ping 10.0.0.1 # traffic sent on SCC 4606 4607 ethrotate - When set to "no" U-Boot does not go through all 4608 available network interfaces. 4609 It just stays at the currently selected interface. 4610 4611 netretry - When set to "no" each network operation will 4612 either succeed or fail without retrying. 4613 When set to "once" the network operation will 4614 fail when all the available network interfaces 4615 are tried once without success. 4616 Useful on scripts which control the retry operation 4617 themselves. 4618 4619 npe_ucode - set load address for the NPE microcode 4620 4621 silent_linux - If set then Linux will be told to boot silently, by 4622 changing the console to be empty. If "yes" it will be 4623 made silent. If "no" it will not be made silent. If 4624 unset, then it will be made silent if the U-Boot console 4625 is silent. 4626 4627 tftpsrcp - If this is set, the value is used for TFTP's 4628 UDP source port. 4629 4630 tftpdstp - If this is set, the value is used for TFTP's UDP 4631 destination port instead of the Well Know Port 69. 4632 4633 tftpblocksize - Block size to use for TFTP transfers; if not set, 4634 we use the TFTP server's default block size 4635 4636 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4637 seconds, minimum value is 1000 = 1 second). Defines 4638 when a packet is considered to be lost so it has to 4639 be retransmitted. The default is 5000 = 5 seconds. 4640 Lowering this value may make downloads succeed 4641 faster in networks with high packet loss rates or 4642 with unreliable TFTP servers. 4643 4644 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4645 unit, minimum value = 0). Defines how many timeouts 4646 can happen during a single file transfer before that 4647 transfer is aborted. The default is 10, and 0 means 4648 'no timeouts allowed'. Increasing this value may help 4649 downloads succeed with high packet loss rates, or with 4650 unreliable TFTP servers or client hardware. 4651 4652 vlan - When set to a value < 4095 the traffic over 4653 Ethernet is encapsulated/received over 802.1q 4654 VLAN tagged frames. 4655 4656 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4657 Unsigned value, in milliseconds. If not set, the period will 4658 be either the default (28000), or a value based on 4659 CONFIG_NET_RETRY_COUNT, if defined. This value has 4660 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4661 4662The following image location variables contain the location of images 4663used in booting. The "Image" column gives the role of the image and is 4664not an environment variable name. The other columns are environment 4665variable names. "File Name" gives the name of the file on a TFTP 4666server, "RAM Address" gives the location in RAM the image will be 4667loaded to, and "Flash Location" gives the image's address in NOR 4668flash or offset in NAND flash. 4669 4670*Note* - these variables don't have to be defined for all boards, some 4671boards currently use other variables for these purposes, and some 4672boards use these variables for other purposes. 4673 4674Image File Name RAM Address Flash Location 4675----- --------- ----------- -------------- 4676u-boot u-boot u-boot_addr_r u-boot_addr 4677Linux kernel bootfile kernel_addr_r kernel_addr 4678device tree blob fdtfile fdt_addr_r fdt_addr 4679ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4680 4681The following environment variables may be used and automatically 4682updated by the network boot commands ("bootp" and "rarpboot"), 4683depending the information provided by your boot server: 4684 4685 bootfile - see above 4686 dnsip - IP address of your Domain Name Server 4687 dnsip2 - IP address of your secondary Domain Name Server 4688 gatewayip - IP address of the Gateway (Router) to use 4689 hostname - Target hostname 4690 ipaddr - see above 4691 netmask - Subnet Mask 4692 rootpath - Pathname of the root filesystem on the NFS server 4693 serverip - see above 4694 4695 4696There are two special Environment Variables: 4697 4698 serial# - contains hardware identification information such 4699 as type string and/or serial number 4700 ethaddr - Ethernet address 4701 4702These variables can be set only once (usually during manufacturing of 4703the board). U-Boot refuses to delete or overwrite these variables 4704once they have been set once. 4705 4706 4707Further special Environment Variables: 4708 4709 ver - Contains the U-Boot version string as printed 4710 with the "version" command. This variable is 4711 readonly (see CONFIG_VERSION_VARIABLE). 4712 4713 4714Please note that changes to some configuration parameters may take 4715only effect after the next boot (yes, that's just like Windoze :-). 4716 4717 4718Callback functions for environment variables: 4719--------------------------------------------- 4720 4721For some environment variables, the behavior of u-boot needs to change 4722when their values are changed. This functionality allows functions to 4723be associated with arbitrary variables. On creation, overwrite, or 4724deletion, the callback will provide the opportunity for some side 4725effect to happen or for the change to be rejected. 4726 4727The callbacks are named and associated with a function using the 4728U_BOOT_ENV_CALLBACK macro in your board or driver code. 4729 4730These callbacks are associated with variables in one of two ways. The 4731static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4732in the board configuration to a string that defines a list of 4733associations. The list must be in the following format: 4734 4735 entry = variable_name[:callback_name] 4736 list = entry[,list] 4737 4738If the callback name is not specified, then the callback is deleted. 4739Spaces are also allowed anywhere in the list. 4740 4741Callbacks can also be associated by defining the ".callbacks" variable 4742with the same list format above. Any association in ".callbacks" will 4743override any association in the static list. You can define 4744CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4745".callbacks" environment variable in the default or embedded environment. 4746 4747If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4748regular expression. This allows multiple variables to be connected to 4749the same callback without explicitly listing them all out. 4750 4751 4752Command Line Parsing: 4753===================== 4754 4755There are two different command line parsers available with U-Boot: 4756the old "simple" one, and the much more powerful "hush" shell: 4757 4758Old, simple command line parser: 4759-------------------------------- 4760 4761- supports environment variables (through setenv / saveenv commands) 4762- several commands on one line, separated by ';' 4763- variable substitution using "... ${name} ..." syntax 4764- special characters ('$', ';') can be escaped by prefixing with '\', 4765 for example: 4766 setenv bootcmd bootm \${address} 4767- You can also escape text by enclosing in single apostrophes, for example: 4768 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4769 4770Hush shell: 4771----------- 4772 4773- similar to Bourne shell, with control structures like 4774 if...then...else...fi, for...do...done; while...do...done, 4775 until...do...done, ... 4776- supports environment ("global") variables (through setenv / saveenv 4777 commands) and local shell variables (through standard shell syntax 4778 "name=value"); only environment variables can be used with "run" 4779 command 4780 4781General rules: 4782-------------- 4783 4784(1) If a command line (or an environment variable executed by a "run" 4785 command) contains several commands separated by semicolon, and 4786 one of these commands fails, then the remaining commands will be 4787 executed anyway. 4788 4789(2) If you execute several variables with one call to run (i. e. 4790 calling run with a list of variables as arguments), any failing 4791 command will cause "run" to terminate, i. e. the remaining 4792 variables are not executed. 4793 4794Note for Redundant Ethernet Interfaces: 4795======================================= 4796 4797Some boards come with redundant Ethernet interfaces; U-Boot supports 4798such configurations and is capable of automatic selection of a 4799"working" interface when needed. MAC assignment works as follows: 4800 4801Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4802MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4803"eth1addr" (=>eth1), "eth2addr", ... 4804 4805If the network interface stores some valid MAC address (for instance 4806in SROM), this is used as default address if there is NO correspon- 4807ding setting in the environment; if the corresponding environment 4808variable is set, this overrides the settings in the card; that means: 4809 4810o If the SROM has a valid MAC address, and there is no address in the 4811 environment, the SROM's address is used. 4812 4813o If there is no valid address in the SROM, and a definition in the 4814 environment exists, then the value from the environment variable is 4815 used. 4816 4817o If both the SROM and the environment contain a MAC address, and 4818 both addresses are the same, this MAC address is used. 4819 4820o If both the SROM and the environment contain a MAC address, and the 4821 addresses differ, the value from the environment is used and a 4822 warning is printed. 4823 4824o If neither SROM nor the environment contain a MAC address, an error 4825 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4826 a random, locally-assigned MAC is used. 4827 4828If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4829will be programmed into hardware as part of the initialization process. This 4830may be skipped by setting the appropriate 'ethmacskip' environment variable. 4831The naming convention is as follows: 4832"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4833 4834Image Formats: 4835============== 4836 4837U-Boot is capable of booting (and performing other auxiliary operations on) 4838images in two formats: 4839 4840New uImage format (FIT) 4841----------------------- 4842 4843Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4844to Flattened Device Tree). It allows the use of images with multiple 4845components (several kernels, ramdisks, etc.), with contents protected by 4846SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4847 4848 4849Old uImage format 4850----------------- 4851 4852Old image format is based on binary files which can be basically anything, 4853preceded by a special header; see the definitions in include/image.h for 4854details; basically, the header defines the following image properties: 4855 4856* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4857 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4858 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4859 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4860 INTEGRITY). 4861* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4862 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4863 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4864* Compression Type (uncompressed, gzip, bzip2) 4865* Load Address 4866* Entry Point 4867* Image Name 4868* Image Timestamp 4869 4870The header is marked by a special Magic Number, and both the header 4871and the data portions of the image are secured against corruption by 4872CRC32 checksums. 4873 4874 4875Linux Support: 4876============== 4877 4878Although U-Boot should support any OS or standalone application 4879easily, the main focus has always been on Linux during the design of 4880U-Boot. 4881 4882U-Boot includes many features that so far have been part of some 4883special "boot loader" code within the Linux kernel. Also, any 4884"initrd" images to be used are no longer part of one big Linux image; 4885instead, kernel and "initrd" are separate images. This implementation 4886serves several purposes: 4887 4888- the same features can be used for other OS or standalone 4889 applications (for instance: using compressed images to reduce the 4890 Flash memory footprint) 4891 4892- it becomes much easier to port new Linux kernel versions because 4893 lots of low-level, hardware dependent stuff are done by U-Boot 4894 4895- the same Linux kernel image can now be used with different "initrd" 4896 images; of course this also means that different kernel images can 4897 be run with the same "initrd". This makes testing easier (you don't 4898 have to build a new "zImage.initrd" Linux image when you just 4899 change a file in your "initrd"). Also, a field-upgrade of the 4900 software is easier now. 4901 4902 4903Linux HOWTO: 4904============ 4905 4906Porting Linux to U-Boot based systems: 4907--------------------------------------- 4908 4909U-Boot cannot save you from doing all the necessary modifications to 4910configure the Linux device drivers for use with your target hardware 4911(no, we don't intend to provide a full virtual machine interface to 4912Linux :-). 4913 4914But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4915 4916Just make sure your machine specific header file (for instance 4917include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4918Information structure as we define in include/asm-<arch>/u-boot.h, 4919and make sure that your definition of IMAP_ADDR uses the same value 4920as your U-Boot configuration in CONFIG_SYS_IMMR. 4921 4922Note that U-Boot now has a driver model, a unified model for drivers. 4923If you are adding a new driver, plumb it into driver model. If there 4924is no uclass available, you are encouraged to create one. See 4925doc/driver-model. 4926 4927 4928Configuring the Linux kernel: 4929----------------------------- 4930 4931No specific requirements for U-Boot. Make sure you have some root 4932device (initial ramdisk, NFS) for your target system. 4933 4934 4935Building a Linux Image: 4936----------------------- 4937 4938With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4939not used. If you use recent kernel source, a new build target 4940"uImage" will exist which automatically builds an image usable by 4941U-Boot. Most older kernels also have support for a "pImage" target, 4942which was introduced for our predecessor project PPCBoot and uses a 4943100% compatible format. 4944 4945Example: 4946 4947 make TQM850L_defconfig 4948 make oldconfig 4949 make dep 4950 make uImage 4951 4952The "uImage" build target uses a special tool (in 'tools/mkimage') to 4953encapsulate a compressed Linux kernel image with header information, 4954CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4955 4956* build a standard "vmlinux" kernel image (in ELF binary format): 4957 4958* convert the kernel into a raw binary image: 4959 4960 ${CROSS_COMPILE}-objcopy -O binary \ 4961 -R .note -R .comment \ 4962 -S vmlinux linux.bin 4963 4964* compress the binary image: 4965 4966 gzip -9 linux.bin 4967 4968* package compressed binary image for U-Boot: 4969 4970 mkimage -A ppc -O linux -T kernel -C gzip \ 4971 -a 0 -e 0 -n "Linux Kernel Image" \ 4972 -d linux.bin.gz uImage 4973 4974 4975The "mkimage" tool can also be used to create ramdisk images for use 4976with U-Boot, either separated from the Linux kernel image, or 4977combined into one file. "mkimage" encapsulates the images with a 64 4978byte header containing information about target architecture, 4979operating system, image type, compression method, entry points, time 4980stamp, CRC32 checksums, etc. 4981 4982"mkimage" can be called in two ways: to verify existing images and 4983print the header information, or to build new images. 4984 4985In the first form (with "-l" option) mkimage lists the information 4986contained in the header of an existing U-Boot image; this includes 4987checksum verification: 4988 4989 tools/mkimage -l image 4990 -l ==> list image header information 4991 4992The second form (with "-d" option) is used to build a U-Boot image 4993from a "data file" which is used as image payload: 4994 4995 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4996 -n name -d data_file image 4997 -A ==> set architecture to 'arch' 4998 -O ==> set operating system to 'os' 4999 -T ==> set image type to 'type' 5000 -C ==> set compression type 'comp' 5001 -a ==> set load address to 'addr' (hex) 5002 -e ==> set entry point to 'ep' (hex) 5003 -n ==> set image name to 'name' 5004 -d ==> use image data from 'datafile' 5005 5006Right now, all Linux kernels for PowerPC systems use the same load 5007address (0x00000000), but the entry point address depends on the 5008kernel version: 5009 5010- 2.2.x kernels have the entry point at 0x0000000C, 5011- 2.3.x and later kernels have the entry point at 0x00000000. 5012 5013So a typical call to build a U-Boot image would read: 5014 5015 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5016 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 5017 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 5018 > examples/uImage.TQM850L 5019 Image Name: 2.4.4 kernel for TQM850L 5020 Created: Wed Jul 19 02:34:59 2000 5021 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5022 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5023 Load Address: 0x00000000 5024 Entry Point: 0x00000000 5025 5026To verify the contents of the image (or check for corruption): 5027 5028 -> tools/mkimage -l examples/uImage.TQM850L 5029 Image Name: 2.4.4 kernel for TQM850L 5030 Created: Wed Jul 19 02:34:59 2000 5031 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5032 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 5033 Load Address: 0x00000000 5034 Entry Point: 0x00000000 5035 5036NOTE: for embedded systems where boot time is critical you can trade 5037speed for memory and install an UNCOMPRESSED image instead: this 5038needs more space in Flash, but boots much faster since it does not 5039need to be uncompressed: 5040 5041 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 5042 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 5043 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 5044 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 5045 > examples/uImage.TQM850L-uncompressed 5046 Image Name: 2.4.4 kernel for TQM850L 5047 Created: Wed Jul 19 02:34:59 2000 5048 Image Type: PowerPC Linux Kernel Image (uncompressed) 5049 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 5050 Load Address: 0x00000000 5051 Entry Point: 0x00000000 5052 5053 5054Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5055when your kernel is intended to use an initial ramdisk: 5056 5057 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5058 > -A ppc -O linux -T ramdisk -C gzip \ 5059 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5060 Image Name: Simple Ramdisk Image 5061 Created: Wed Jan 12 14:01:50 2000 5062 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5063 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5064 Load Address: 0x00000000 5065 Entry Point: 0x00000000 5066 5067The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5068option performs the converse operation of the mkimage's second form (the "-d" 5069option). Given an image built by mkimage, the dumpimage extracts a "data file" 5070from the image: 5071 5072 tools/dumpimage -i image -T type -p position data_file 5073 -i ==> extract from the 'image' a specific 'data_file' 5074 -T ==> set image type to 'type' 5075 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5076 5077 5078Installing a Linux Image: 5079------------------------- 5080 5081To downloading a U-Boot image over the serial (console) interface, 5082you must convert the image to S-Record format: 5083 5084 objcopy -I binary -O srec examples/image examples/image.srec 5085 5086The 'objcopy' does not understand the information in the U-Boot 5087image header, so the resulting S-Record file will be relative to 5088address 0x00000000. To load it to a given address, you need to 5089specify the target address as 'offset' parameter with the 'loads' 5090command. 5091 5092Example: install the image to address 0x40100000 (which on the 5093TQM8xxL is in the first Flash bank): 5094 5095 => erase 40100000 401FFFFF 5096 5097 .......... done 5098 Erased 8 sectors 5099 5100 => loads 40100000 5101 ## Ready for S-Record download ... 5102 ~>examples/image.srec 5103 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5104 ... 5105 15989 15990 15991 15992 5106 [file transfer complete] 5107 [connected] 5108 ## Start Addr = 0x00000000 5109 5110 5111You can check the success of the download using the 'iminfo' command; 5112this includes a checksum verification so you can be sure no data 5113corruption happened: 5114 5115 => imi 40100000 5116 5117 ## Checking Image at 40100000 ... 5118 Image Name: 2.2.13 for initrd on TQM850L 5119 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5120 Data Size: 335725 Bytes = 327 kB = 0 MB 5121 Load Address: 00000000 5122 Entry Point: 0000000c 5123 Verifying Checksum ... OK 5124 5125 5126Boot Linux: 5127----------- 5128 5129The "bootm" command is used to boot an application that is stored in 5130memory (RAM or Flash). In case of a Linux kernel image, the contents 5131of the "bootargs" environment variable is passed to the kernel as 5132parameters. You can check and modify this variable using the 5133"printenv" and "setenv" commands: 5134 5135 5136 => printenv bootargs 5137 bootargs=root=/dev/ram 5138 5139 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5140 5141 => printenv bootargs 5142 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5143 5144 => bootm 40020000 5145 ## Booting Linux kernel at 40020000 ... 5146 Image Name: 2.2.13 for NFS on TQM850L 5147 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5148 Data Size: 381681 Bytes = 372 kB = 0 MB 5149 Load Address: 00000000 5150 Entry Point: 0000000c 5151 Verifying Checksum ... OK 5152 Uncompressing Kernel Image ... OK 5153 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 5154 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5155 time_init: decrementer frequency = 187500000/60 5156 Calibrating delay loop... 49.77 BogoMIPS 5157 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5158 ... 5159 5160If you want to boot a Linux kernel with initial RAM disk, you pass 5161the memory addresses of both the kernel and the initrd image (PPBCOOT 5162format!) to the "bootm" command: 5163 5164 => imi 40100000 40200000 5165 5166 ## Checking Image at 40100000 ... 5167 Image Name: 2.2.13 for initrd on TQM850L 5168 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5169 Data Size: 335725 Bytes = 327 kB = 0 MB 5170 Load Address: 00000000 5171 Entry Point: 0000000c 5172 Verifying Checksum ... OK 5173 5174 ## Checking Image at 40200000 ... 5175 Image Name: Simple Ramdisk Image 5176 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5177 Data Size: 566530 Bytes = 553 kB = 0 MB 5178 Load Address: 00000000 5179 Entry Point: 00000000 5180 Verifying Checksum ... OK 5181 5182 => bootm 40100000 40200000 5183 ## Booting Linux kernel at 40100000 ... 5184 Image Name: 2.2.13 for initrd on TQM850L 5185 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5186 Data Size: 335725 Bytes = 327 kB = 0 MB 5187 Load Address: 00000000 5188 Entry Point: 0000000c 5189 Verifying Checksum ... OK 5190 Uncompressing Kernel Image ... OK 5191 ## Loading RAMDisk Image at 40200000 ... 5192 Image Name: Simple Ramdisk Image 5193 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5194 Data Size: 566530 Bytes = 553 kB = 0 MB 5195 Load Address: 00000000 5196 Entry Point: 00000000 5197 Verifying Checksum ... OK 5198 Loading Ramdisk ... OK 5199 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 5200 Boot arguments: root=/dev/ram 5201 time_init: decrementer frequency = 187500000/60 5202 Calibrating delay loop... 49.77 BogoMIPS 5203 ... 5204 RAMDISK: Compressed image found at block 0 5205 VFS: Mounted root (ext2 filesystem). 5206 5207 bash# 5208 5209Boot Linux and pass a flat device tree: 5210----------- 5211 5212First, U-Boot must be compiled with the appropriate defines. See the section 5213titled "Linux Kernel Interface" above for a more in depth explanation. The 5214following is an example of how to start a kernel and pass an updated 5215flat device tree: 5216 5217=> print oftaddr 5218oftaddr=0x300000 5219=> print oft 5220oft=oftrees/mpc8540ads.dtb 5221=> tftp $oftaddr $oft 5222Speed: 1000, full duplex 5223Using TSEC0 device 5224TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5225Filename 'oftrees/mpc8540ads.dtb'. 5226Load address: 0x300000 5227Loading: # 5228done 5229Bytes transferred = 4106 (100a hex) 5230=> tftp $loadaddr $bootfile 5231Speed: 1000, full duplex 5232Using TSEC0 device 5233TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5234Filename 'uImage'. 5235Load address: 0x200000 5236Loading:############ 5237done 5238Bytes transferred = 1029407 (fb51f hex) 5239=> print loadaddr 5240loadaddr=200000 5241=> print oftaddr 5242oftaddr=0x300000 5243=> bootm $loadaddr - $oftaddr 5244## Booting image at 00200000 ... 5245 Image Name: Linux-2.6.17-dirty 5246 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5247 Data Size: 1029343 Bytes = 1005.2 kB 5248 Load Address: 00000000 5249 Entry Point: 00000000 5250 Verifying Checksum ... OK 5251 Uncompressing Kernel Image ... OK 5252Booting using flat device tree at 0x300000 5253Using MPC85xx ADS machine description 5254Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5255[snip] 5256 5257 5258More About U-Boot Image Types: 5259------------------------------ 5260 5261U-Boot supports the following image types: 5262 5263 "Standalone Programs" are directly runnable in the environment 5264 provided by U-Boot; it is expected that (if they behave 5265 well) you can continue to work in U-Boot after return from 5266 the Standalone Program. 5267 "OS Kernel Images" are usually images of some Embedded OS which 5268 will take over control completely. Usually these programs 5269 will install their own set of exception handlers, device 5270 drivers, set up the MMU, etc. - this means, that you cannot 5271 expect to re-enter U-Boot except by resetting the CPU. 5272 "RAMDisk Images" are more or less just data blocks, and their 5273 parameters (address, size) are passed to an OS kernel that is 5274 being started. 5275 "Multi-File Images" contain several images, typically an OS 5276 (Linux) kernel image and one or more data images like 5277 RAMDisks. This construct is useful for instance when you want 5278 to boot over the network using BOOTP etc., where the boot 5279 server provides just a single image file, but you want to get 5280 for instance an OS kernel and a RAMDisk image. 5281 5282 "Multi-File Images" start with a list of image sizes, each 5283 image size (in bytes) specified by an "uint32_t" in network 5284 byte order. This list is terminated by an "(uint32_t)0". 5285 Immediately after the terminating 0 follow the images, one by 5286 one, all aligned on "uint32_t" boundaries (size rounded up to 5287 a multiple of 4 bytes). 5288 5289 "Firmware Images" are binary images containing firmware (like 5290 U-Boot or FPGA images) which usually will be programmed to 5291 flash memory. 5292 5293 "Script files" are command sequences that will be executed by 5294 U-Boot's command interpreter; this feature is especially 5295 useful when you configure U-Boot to use a real shell (hush) 5296 as command interpreter. 5297 5298Booting the Linux zImage: 5299------------------------- 5300 5301On some platforms, it's possible to boot Linux zImage. This is done 5302using the "bootz" command. The syntax of "bootz" command is the same 5303as the syntax of "bootm" command. 5304 5305Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5306kernel with raw initrd images. The syntax is slightly different, the 5307address of the initrd must be augmented by it's size, in the following 5308format: "<initrd addres>:<initrd size>". 5309 5310 5311Standalone HOWTO: 5312================= 5313 5314One of the features of U-Boot is that you can dynamically load and 5315run "standalone" applications, which can use some resources of 5316U-Boot like console I/O functions or interrupt services. 5317 5318Two simple examples are included with the sources: 5319 5320"Hello World" Demo: 5321------------------- 5322 5323'examples/hello_world.c' contains a small "Hello World" Demo 5324application; it is automatically compiled when you build U-Boot. 5325It's configured to run at address 0x00040004, so you can play with it 5326like that: 5327 5328 => loads 5329 ## Ready for S-Record download ... 5330 ~>examples/hello_world.srec 5331 1 2 3 4 5 6 7 8 9 10 11 ... 5332 [file transfer complete] 5333 [connected] 5334 ## Start Addr = 0x00040004 5335 5336 => go 40004 Hello World! This is a test. 5337 ## Starting application at 0x00040004 ... 5338 Hello World 5339 argc = 7 5340 argv[0] = "40004" 5341 argv[1] = "Hello" 5342 argv[2] = "World!" 5343 argv[3] = "This" 5344 argv[4] = "is" 5345 argv[5] = "a" 5346 argv[6] = "test." 5347 argv[7] = "<NULL>" 5348 Hit any key to exit ... 5349 5350 ## Application terminated, rc = 0x0 5351 5352Another example, which demonstrates how to register a CPM interrupt 5353handler with the U-Boot code, can be found in 'examples/timer.c'. 5354Here, a CPM timer is set up to generate an interrupt every second. 5355The interrupt service routine is trivial, just printing a '.' 5356character, but this is just a demo program. The application can be 5357controlled by the following keys: 5358 5359 ? - print current values og the CPM Timer registers 5360 b - enable interrupts and start timer 5361 e - stop timer and disable interrupts 5362 q - quit application 5363 5364 => loads 5365 ## Ready for S-Record download ... 5366 ~>examples/timer.srec 5367 1 2 3 4 5 6 7 8 9 10 11 ... 5368 [file transfer complete] 5369 [connected] 5370 ## Start Addr = 0x00040004 5371 5372 => go 40004 5373 ## Starting application at 0x00040004 ... 5374 TIMERS=0xfff00980 5375 Using timer 1 5376 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5377 5378Hit 'b': 5379 [q, b, e, ?] Set interval 1000000 us 5380 Enabling timer 5381Hit '?': 5382 [q, b, e, ?] ........ 5383 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5384Hit '?': 5385 [q, b, e, ?] . 5386 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5387Hit '?': 5388 [q, b, e, ?] . 5389 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5390Hit '?': 5391 [q, b, e, ?] . 5392 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5393Hit 'e': 5394 [q, b, e, ?] ...Stopping timer 5395Hit 'q': 5396 [q, b, e, ?] ## Application terminated, rc = 0x0 5397 5398 5399Minicom warning: 5400================ 5401 5402Over time, many people have reported problems when trying to use the 5403"minicom" terminal emulation program for serial download. I (wd) 5404consider minicom to be broken, and recommend not to use it. Under 5405Unix, I recommend to use C-Kermit for general purpose use (and 5406especially for kermit binary protocol download ("loadb" command), and 5407use "cu" for S-Record download ("loads" command). See 5408http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5409for help with kermit. 5410 5411 5412Nevertheless, if you absolutely want to use it try adding this 5413configuration to your "File transfer protocols" section: 5414 5415 Name Program Name U/D FullScr IO-Red. Multi 5416 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5417 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5418 5419 5420NetBSD Notes: 5421============= 5422 5423Starting at version 0.9.2, U-Boot supports NetBSD both as host 5424(build U-Boot) and target system (boots NetBSD/mpc8xx). 5425 5426Building requires a cross environment; it is known to work on 5427NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5428need gmake since the Makefiles are not compatible with BSD make). 5429Note that the cross-powerpc package does not install include files; 5430attempting to build U-Boot will fail because <machine/ansi.h> is 5431missing. This file has to be installed and patched manually: 5432 5433 # cd /usr/pkg/cross/powerpc-netbsd/include 5434 # mkdir powerpc 5435 # ln -s powerpc machine 5436 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5437 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5438 5439Native builds *don't* work due to incompatibilities between native 5440and U-Boot include files. 5441 5442Booting assumes that (the first part of) the image booted is a 5443stage-2 loader which in turn loads and then invokes the kernel 5444proper. Loader sources will eventually appear in the NetBSD source 5445tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5446meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5447 5448 5449Implementation Internals: 5450========================= 5451 5452The following is not intended to be a complete description of every 5453implementation detail. However, it should help to understand the 5454inner workings of U-Boot and make it easier to port it to custom 5455hardware. 5456 5457 5458Initial Stack, Global Data: 5459--------------------------- 5460 5461The implementation of U-Boot is complicated by the fact that U-Boot 5462starts running out of ROM (flash memory), usually without access to 5463system RAM (because the memory controller is not initialized yet). 5464This means that we don't have writable Data or BSS segments, and BSS 5465is not initialized as zero. To be able to get a C environment working 5466at all, we have to allocate at least a minimal stack. Implementation 5467options for this are defined and restricted by the CPU used: Some CPU 5468models provide on-chip memory (like the IMMR area on MPC8xx and 5469MPC826x processors), on others (parts of) the data cache can be 5470locked as (mis-) used as memory, etc. 5471 5472 Chris Hallinan posted a good summary of these issues to the 5473 U-Boot mailing list: 5474 5475 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5476 From: "Chris Hallinan" <clh@net1plus.com> 5477 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5478 ... 5479 5480 Correct me if I'm wrong, folks, but the way I understand it 5481 is this: Using DCACHE as initial RAM for Stack, etc, does not 5482 require any physical RAM backing up the cache. The cleverness 5483 is that the cache is being used as a temporary supply of 5484 necessary storage before the SDRAM controller is setup. It's 5485 beyond the scope of this list to explain the details, but you 5486 can see how this works by studying the cache architecture and 5487 operation in the architecture and processor-specific manuals. 5488 5489 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5490 is another option for the system designer to use as an 5491 initial stack/RAM area prior to SDRAM being available. Either 5492 option should work for you. Using CS 4 should be fine if your 5493 board designers haven't used it for something that would 5494 cause you grief during the initial boot! It is frequently not 5495 used. 5496 5497 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5498 with your processor/board/system design. The default value 5499 you will find in any recent u-boot distribution in 5500 walnut.h should work for you. I'd set it to a value larger 5501 than your SDRAM module. If you have a 64MB SDRAM module, set 5502 it above 400_0000. Just make sure your board has no resources 5503 that are supposed to respond to that address! That code in 5504 start.S has been around a while and should work as is when 5505 you get the config right. 5506 5507 -Chris Hallinan 5508 DS4.COM, Inc. 5509 5510It is essential to remember this, since it has some impact on the C 5511code for the initialization procedures: 5512 5513* Initialized global data (data segment) is read-only. Do not attempt 5514 to write it. 5515 5516* Do not use any uninitialized global data (or implicitly initialized 5517 as zero data - BSS segment) at all - this is undefined, initiali- 5518 zation is performed later (when relocating to RAM). 5519 5520* Stack space is very limited. Avoid big data buffers or things like 5521 that. 5522 5523Having only the stack as writable memory limits means we cannot use 5524normal global data to share information between the code. But it 5525turned out that the implementation of U-Boot can be greatly 5526simplified by making a global data structure (gd_t) available to all 5527functions. We could pass a pointer to this data as argument to _all_ 5528functions, but this would bloat the code. Instead we use a feature of 5529the GCC compiler (Global Register Variables) to share the data: we 5530place a pointer (gd) to the global data into a register which we 5531reserve for this purpose. 5532 5533When choosing a register for such a purpose we are restricted by the 5534relevant (E)ABI specifications for the current architecture, and by 5535GCC's implementation. 5536 5537For PowerPC, the following registers have specific use: 5538 R1: stack pointer 5539 R2: reserved for system use 5540 R3-R4: parameter passing and return values 5541 R5-R10: parameter passing 5542 R13: small data area pointer 5543 R30: GOT pointer 5544 R31: frame pointer 5545 5546 (U-Boot also uses R12 as internal GOT pointer. r12 5547 is a volatile register so r12 needs to be reset when 5548 going back and forth between asm and C) 5549 5550 ==> U-Boot will use R2 to hold a pointer to the global data 5551 5552 Note: on PPC, we could use a static initializer (since the 5553 address of the global data structure is known at compile time), 5554 but it turned out that reserving a register results in somewhat 5555 smaller code - although the code savings are not that big (on 5556 average for all boards 752 bytes for the whole U-Boot image, 5557 624 text + 127 data). 5558 5559On ARM, the following registers are used: 5560 5561 R0: function argument word/integer result 5562 R1-R3: function argument word 5563 R9: platform specific 5564 R10: stack limit (used only if stack checking is enabled) 5565 R11: argument (frame) pointer 5566 R12: temporary workspace 5567 R13: stack pointer 5568 R14: link register 5569 R15: program counter 5570 5571 ==> U-Boot will use R9 to hold a pointer to the global data 5572 5573 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5574 5575On Nios II, the ABI is documented here: 5576 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5577 5578 ==> U-Boot will use gp to hold a pointer to the global data 5579 5580 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5581 to access small data sections, so gp is free. 5582 5583On NDS32, the following registers are used: 5584 5585 R0-R1: argument/return 5586 R2-R5: argument 5587 R15: temporary register for assembler 5588 R16: trampoline register 5589 R28: frame pointer (FP) 5590 R29: global pointer (GP) 5591 R30: link register (LP) 5592 R31: stack pointer (SP) 5593 PC: program counter (PC) 5594 5595 ==> U-Boot will use R10 to hold a pointer to the global data 5596 5597NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5598or current versions of GCC may "optimize" the code too much. 5599 5600Memory Management: 5601------------------ 5602 5603U-Boot runs in system state and uses physical addresses, i.e. the 5604MMU is not used either for address mapping nor for memory protection. 5605 5606The available memory is mapped to fixed addresses using the memory 5607controller. In this process, a contiguous block is formed for each 5608memory type (Flash, SDRAM, SRAM), even when it consists of several 5609physical memory banks. 5610 5611U-Boot is installed in the first 128 kB of the first Flash bank (on 5612TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5613booting and sizing and initializing DRAM, the code relocates itself 5614to the upper end of DRAM. Immediately below the U-Boot code some 5615memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5616configuration setting]. Below that, a structure with global Board 5617Info data is placed, followed by the stack (growing downward). 5618 5619Additionally, some exception handler code is copied to the low 8 kB 5620of DRAM (0x00000000 ... 0x00001FFF). 5621 5622So a typical memory configuration with 16 MB of DRAM could look like 5623this: 5624 5625 0x0000 0000 Exception Vector code 5626 : 5627 0x0000 1FFF 5628 0x0000 2000 Free for Application Use 5629 : 5630 : 5631 5632 : 5633 : 5634 0x00FB FF20 Monitor Stack (Growing downward) 5635 0x00FB FFAC Board Info Data and permanent copy of global data 5636 0x00FC 0000 Malloc Arena 5637 : 5638 0x00FD FFFF 5639 0x00FE 0000 RAM Copy of Monitor Code 5640 ... eventually: LCD or video framebuffer 5641 ... eventually: pRAM (Protected RAM - unchanged by reset) 5642 0x00FF FFFF [End of RAM] 5643 5644 5645System Initialization: 5646---------------------- 5647 5648In the reset configuration, U-Boot starts at the reset entry point 5649(on most PowerPC systems at address 0x00000100). Because of the reset 5650configuration for CS0# this is a mirror of the on board Flash memory. 5651To be able to re-map memory U-Boot then jumps to its link address. 5652To be able to implement the initialization code in C, a (small!) 5653initial stack is set up in the internal Dual Ported RAM (in case CPUs 5654which provide such a feature like), or in a locked part of the data 5655cache. After that, U-Boot initializes the CPU core, the caches and 5656the SIU. 5657 5658Next, all (potentially) available memory banks are mapped using a 5659preliminary mapping. For example, we put them on 512 MB boundaries 5660(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5661on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5662programmed for SDRAM access. Using the temporary configuration, a 5663simple memory test is run that determines the size of the SDRAM 5664banks. 5665 5666When there is more than one SDRAM bank, and the banks are of 5667different size, the largest is mapped first. For equal size, the first 5668bank (CS2#) is mapped first. The first mapping is always for address 56690x00000000, with any additional banks following immediately to create 5670contiguous memory starting from 0. 5671 5672Then, the monitor installs itself at the upper end of the SDRAM area 5673and allocates memory for use by malloc() and for the global Board 5674Info data; also, the exception vector code is copied to the low RAM 5675pages, and the final stack is set up. 5676 5677Only after this relocation will you have a "normal" C environment; 5678until that you are restricted in several ways, mostly because you are 5679running from ROM, and because the code will have to be relocated to a 5680new address in RAM. 5681 5682 5683U-Boot Porting Guide: 5684---------------------- 5685 5686[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5687list, October 2002] 5688 5689 5690int main(int argc, char *argv[]) 5691{ 5692 sighandler_t no_more_time; 5693 5694 signal(SIGALRM, no_more_time); 5695 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5696 5697 if (available_money > available_manpower) { 5698 Pay consultant to port U-Boot; 5699 return 0; 5700 } 5701 5702 Download latest U-Boot source; 5703 5704 Subscribe to u-boot mailing list; 5705 5706 if (clueless) 5707 email("Hi, I am new to U-Boot, how do I get started?"); 5708 5709 while (learning) { 5710 Read the README file in the top level directory; 5711 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5712 Read applicable doc/*.README; 5713 Read the source, Luke; 5714 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5715 } 5716 5717 if (available_money > toLocalCurrency ($2500)) 5718 Buy a BDI3000; 5719 else 5720 Add a lot of aggravation and time; 5721 5722 if (a similar board exists) { /* hopefully... */ 5723 cp -a board/<similar> board/<myboard> 5724 cp include/configs/<similar>.h include/configs/<myboard>.h 5725 } else { 5726 Create your own board support subdirectory; 5727 Create your own board include/configs/<myboard>.h file; 5728 } 5729 Edit new board/<myboard> files 5730 Edit new include/configs/<myboard>.h 5731 5732 while (!accepted) { 5733 while (!running) { 5734 do { 5735 Add / modify source code; 5736 } until (compiles); 5737 Debug; 5738 if (clueless) 5739 email("Hi, I am having problems..."); 5740 } 5741 Send patch file to the U-Boot email list; 5742 if (reasonable critiques) 5743 Incorporate improvements from email list code review; 5744 else 5745 Defend code as written; 5746 } 5747 5748 return 0; 5749} 5750 5751void no_more_time (int sig) 5752{ 5753 hire_a_guru(); 5754} 5755 5756 5757Coding Standards: 5758----------------- 5759 5760All contributions to U-Boot should conform to the Linux kernel 5761coding style; see the file "Documentation/CodingStyle" and the script 5762"scripts/Lindent" in your Linux kernel source directory. 5763 5764Source files originating from a different project (for example the 5765MTD subsystem) are generally exempt from these guidelines and are not 5766reformatted to ease subsequent migration to newer versions of those 5767sources. 5768 5769Please note that U-Boot is implemented in C (and to some small parts in 5770Assembler); no C++ is used, so please do not use C++ style comments (//) 5771in your code. 5772 5773Please also stick to the following formatting rules: 5774- remove any trailing white space 5775- use TAB characters for indentation and vertical alignment, not spaces 5776- make sure NOT to use DOS '\r\n' line feeds 5777- do not add more than 2 consecutive empty lines to source files 5778- do not add trailing empty lines to source files 5779 5780Submissions which do not conform to the standards may be returned 5781with a request to reformat the changes. 5782 5783 5784Submitting Patches: 5785------------------- 5786 5787Since the number of patches for U-Boot is growing, we need to 5788establish some rules. Submissions which do not conform to these rules 5789may be rejected, even when they contain important and valuable stuff. 5790 5791Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5792 5793Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5794see http://lists.denx.de/mailman/listinfo/u-boot 5795 5796When you send a patch, please include the following information with 5797it: 5798 5799* For bug fixes: a description of the bug and how your patch fixes 5800 this bug. Please try to include a way of demonstrating that the 5801 patch actually fixes something. 5802 5803* For new features: a description of the feature and your 5804 implementation. 5805 5806* A CHANGELOG entry as plaintext (separate from the patch) 5807 5808* For major contributions, add a MAINTAINERS file with your 5809 information and associated file and directory references. 5810 5811* When you add support for a new board, don't forget to add a 5812 maintainer e-mail address to the boards.cfg file, too. 5813 5814* If your patch adds new configuration options, don't forget to 5815 document these in the README file. 5816 5817* The patch itself. If you are using git (which is *strongly* 5818 recommended) you can easily generate the patch using the 5819 "git format-patch". If you then use "git send-email" to send it to 5820 the U-Boot mailing list, you will avoid most of the common problems 5821 with some other mail clients. 5822 5823 If you cannot use git, use "diff -purN OLD NEW". If your version of 5824 diff does not support these options, then get the latest version of 5825 GNU diff. 5826 5827 The current directory when running this command shall be the parent 5828 directory of the U-Boot source tree (i. e. please make sure that 5829 your patch includes sufficient directory information for the 5830 affected files). 5831 5832 We prefer patches as plain text. MIME attachments are discouraged, 5833 and compressed attachments must not be used. 5834 5835* If one logical set of modifications affects or creates several 5836 files, all these changes shall be submitted in a SINGLE patch file. 5837 5838* Changesets that contain different, unrelated modifications shall be 5839 submitted as SEPARATE patches, one patch per changeset. 5840 5841 5842Notes: 5843 5844* Before sending the patch, run the buildman script on your patched 5845 source tree and make sure that no errors or warnings are reported 5846 for any of the boards. 5847 5848* Keep your modifications to the necessary minimum: A patch 5849 containing several unrelated changes or arbitrary reformats will be 5850 returned with a request to re-formatting / split it. 5851 5852* If you modify existing code, make sure that your new code does not 5853 add to the memory footprint of the code ;-) Small is beautiful! 5854 When adding new features, these should compile conditionally only 5855 (using #ifdef), and the resulting code with the new feature 5856 disabled must not need more memory than the old code without your 5857 modification. 5858 5859* Remember that there is a size limit of 100 kB per message on the 5860 u-boot mailing list. Bigger patches will be moderated. If they are 5861 reasonable and not too big, they will be acknowledged. But patches 5862 bigger than the size limit should be avoided. 5863