1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /m68k Files generic to m68k architecture 140 /microblaze Files generic to microblaze architecture 141 /mips Files generic to MIPS architecture 142 /nds32 Files generic to NDS32 architecture 143 /nios2 Files generic to Altera NIOS2 architecture 144 /openrisc Files generic to OpenRISC architecture 145 /powerpc Files generic to PowerPC architecture 146 /sandbox Files generic to HW-independent "sandbox" 147 /sh Files generic to SH architecture 148 /x86 Files generic to x86 architecture 149/api Machine/arch independent API for external apps 150/board Board dependent files 151/cmd U-Boot commands functions 152/common Misc architecture independent functions 153/configs Board default configuration files 154/disk Code for disk drive partition handling 155/doc Documentation (don't expect too much) 156/drivers Commonly used device drivers 157/dts Contains Makefile for building internal U-Boot fdt. 158/examples Example code for standalone applications, etc. 159/fs Filesystem code (cramfs, ext2, jffs2, etc.) 160/include Header Files 161/lib Library routines generic to all architectures 162/Licenses Various license files 163/net Networking code 164/post Power On Self Test 165/scripts Various build scripts and Makefiles 166/test Various unit test files 167/tools Tools to build S-Record or U-Boot images, etc. 168 169Software Configuration: 170======================= 171 172Configuration is usually done using C preprocessor defines; the 173rationale behind that is to avoid dead code whenever possible. 174 175There are two classes of configuration variables: 176 177* Configuration _OPTIONS_: 178 These are selectable by the user and have names beginning with 179 "CONFIG_". 180 181* Configuration _SETTINGS_: 182 These depend on the hardware etc. and should not be meddled with if 183 you don't know what you're doing; they have names beginning with 184 "CONFIG_SYS_". 185 186Previously, all configuration was done by hand, which involved creating 187symbolic links and editing configuration files manually. More recently, 188U-Boot has added the Kbuild infrastructure used by the Linux kernel, 189allowing you to use the "make menuconfig" command to configure your 190build. 191 192 193Selection of Processor Architecture and Board Type: 194--------------------------------------------------- 195 196For all supported boards there are ready-to-use default 197configurations available; just type "make <board_name>_defconfig". 198 199Example: For a TQM823L module type: 200 201 cd u-boot 202 make TQM823L_defconfig 203 204Note: If you're looking for the default configuration file for a board 205you're sure used to be there but is now missing, check the file 206doc/README.scrapyard for a list of no longer supported boards. 207 208Sandbox Environment: 209-------------------- 210 211U-Boot can be built natively to run on a Linux host using the 'sandbox' 212board. This allows feature development which is not board- or architecture- 213specific to be undertaken on a native platform. The sandbox is also used to 214run some of U-Boot's tests. 215 216See board/sandbox/README.sandbox for more details. 217 218 219Board Initialisation Flow: 220-------------------------- 221 222This is the intended start-up flow for boards. This should apply for both 223SPL and U-Boot proper (i.e. they both follow the same rules). 224 225Note: "SPL" stands for "Secondary Program Loader," which is explained in 226more detail later in this file. 227 228At present, SPL mostly uses a separate code path, but the function names 229and roles of each function are the same. Some boards or architectures 230may not conform to this. At least most ARM boards which use 231CONFIG_SPL_FRAMEWORK conform to this. 232 233Execution typically starts with an architecture-specific (and possibly 234CPU-specific) start.S file, such as: 235 236 - arch/arm/cpu/armv7/start.S 237 - arch/powerpc/cpu/mpc83xx/start.S 238 - arch/mips/cpu/start.S 239 240and so on. From there, three functions are called; the purpose and 241limitations of each of these functions are described below. 242 243lowlevel_init(): 244 - purpose: essential init to permit execution to reach board_init_f() 245 - no global_data or BSS 246 - there is no stack (ARMv7 may have one but it will soon be removed) 247 - must not set up SDRAM or use console 248 - must only do the bare minimum to allow execution to continue to 249 board_init_f() 250 - this is almost never needed 251 - return normally from this function 252 253board_init_f(): 254 - purpose: set up the machine ready for running board_init_r(): 255 i.e. SDRAM and serial UART 256 - global_data is available 257 - stack is in SRAM 258 - BSS is not available, so you cannot use global/static variables, 259 only stack variables and global_data 260 261 Non-SPL-specific notes: 262 - dram_init() is called to set up DRAM. If already done in SPL this 263 can do nothing 264 265 SPL-specific notes: 266 - you can override the entire board_init_f() function with your own 267 version as needed. 268 - preloader_console_init() can be called here in extremis 269 - should set up SDRAM, and anything needed to make the UART work 270 - these is no need to clear BSS, it will be done by crt0.S 271 - must return normally from this function (don't call board_init_r() 272 directly) 273 274Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 275this point the stack and global_data are relocated to below 276CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 277memory. 278 279board_init_r(): 280 - purpose: main execution, common code 281 - global_data is available 282 - SDRAM is available 283 - BSS is available, all static/global variables can be used 284 - execution eventually continues to main_loop() 285 286 Non-SPL-specific notes: 287 - U-Boot is relocated to the top of memory and is now running from 288 there. 289 290 SPL-specific notes: 291 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 292 CONFIG_SPL_STACK_R_ADDR points into SDRAM 293 - preloader_console_init() can be called here - typically this is 294 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 295 spl_board_init() function containing this call 296 - loads U-Boot or (in falcon mode) Linux 297 298 299 300Configuration Options: 301---------------------- 302 303Configuration depends on the combination of board and CPU type; all 304such information is kept in a configuration file 305"include/configs/<board_name>.h". 306 307Example: For a TQM823L module, all configuration settings are in 308"include/configs/TQM823L.h". 309 310 311Many of the options are named exactly as the corresponding Linux 312kernel configuration options. The intention is to make it easier to 313build a config tool - later. 314 315 316The following options need to be configured: 317 318- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 319 320- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 321 322- Marvell Family Member 323 CONFIG_SYS_MVFS - define it if you want to enable 324 multiple fs option at one time 325 for marvell soc family 326 327- 85xx CPU Options: 328 CONFIG_SYS_PPC64 329 330 Specifies that the core is a 64-bit PowerPC implementation (implements 331 the "64" category of the Power ISA). This is necessary for ePAPR 332 compliance, among other possible reasons. 333 334 CONFIG_SYS_FSL_TBCLK_DIV 335 336 Defines the core time base clock divider ratio compared to the 337 system clock. On most PQ3 devices this is 8, on newer QorIQ 338 devices it can be 16 or 32. The ratio varies from SoC to Soc. 339 340 CONFIG_SYS_FSL_PCIE_COMPAT 341 342 Defines the string to utilize when trying to match PCIe device 343 tree nodes for the given platform. 344 345 CONFIG_SYS_FSL_ERRATUM_A004510 346 347 Enables a workaround for erratum A004510. If set, 348 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 350 351 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 352 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 353 354 Defines one or two SoC revisions (low 8 bits of SVR) 355 for which the A004510 workaround should be applied. 356 357 The rest of SVR is either not relevant to the decision 358 of whether the erratum is present (e.g. p2040 versus 359 p2041) or is implied by the build target, which controls 360 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 361 362 See Freescale App Note 4493 for more information about 363 this erratum. 364 365 CONFIG_A003399_NOR_WORKAROUND 366 Enables a workaround for IFC erratum A003399. It is only 367 required during NOR boot. 368 369 CONFIG_A008044_WORKAROUND 370 Enables a workaround for T1040/T1042 erratum A008044. It is only 371 required during NAND boot and valid for Rev 1.0 SoC revision 372 373 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 374 375 This is the value to write into CCSR offset 0x18600 376 according to the A004510 workaround. 377 378 CONFIG_SYS_FSL_DSP_DDR_ADDR 379 This value denotes start offset of DDR memory which is 380 connected exclusively to the DSP cores. 381 382 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 383 This value denotes start offset of M2 memory 384 which is directly connected to the DSP core. 385 386 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 387 This value denotes start offset of M3 memory which is directly 388 connected to the DSP core. 389 390 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 391 This value denotes start offset of DSP CCSR space. 392 393 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 394 Single Source Clock is clocking mode present in some of FSL SoC's. 395 In this mode, a single differential clock is used to supply 396 clocks to the sysclock, ddrclock and usbclock. 397 398 CONFIG_SYS_CPC_REINIT_F 399 This CONFIG is defined when the CPC is configured as SRAM at the 400 time of U-Boot entry and is required to be re-initialized. 401 402 CONFIG_DEEP_SLEEP 403 Indicates this SoC supports deep sleep feature. If deep sleep is 404 supported, core will start to execute uboot when wakes up. 405 406- Generic CPU options: 407 CONFIG_SYS_GENERIC_GLOBAL_DATA 408 Defines global data is initialized in generic board board_init_f(). 409 If this macro is defined, global data is created and cleared in 410 generic board board_init_f(). Without this macro, architecture/board 411 should initialize global data before calling board_init_f(). 412 413 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 414 415 Defines the endianess of the CPU. Implementation of those 416 values is arch specific. 417 418 CONFIG_SYS_FSL_DDR 419 Freescale DDR driver in use. This type of DDR controller is 420 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 421 SoCs. 422 423 CONFIG_SYS_FSL_DDR_ADDR 424 Freescale DDR memory-mapped register base. 425 426 CONFIG_SYS_FSL_DDR_EMU 427 Specify emulator support for DDR. Some DDR features such as 428 deskew training are not available. 429 430 CONFIG_SYS_FSL_DDRC_GEN1 431 Freescale DDR1 controller. 432 433 CONFIG_SYS_FSL_DDRC_GEN2 434 Freescale DDR2 controller. 435 436 CONFIG_SYS_FSL_DDRC_GEN3 437 Freescale DDR3 controller. 438 439 CONFIG_SYS_FSL_DDRC_GEN4 440 Freescale DDR4 controller. 441 442 CONFIG_SYS_FSL_DDRC_ARM_GEN3 443 Freescale DDR3 controller for ARM-based SoCs. 444 445 CONFIG_SYS_FSL_DDR1 446 Board config to use DDR1. It can be enabled for SoCs with 447 Freescale DDR1 or DDR2 controllers, depending on the board 448 implemetation. 449 450 CONFIG_SYS_FSL_DDR2 451 Board config to use DDR2. It can be enabled for SoCs with 452 Freescale DDR2 or DDR3 controllers, depending on the board 453 implementation. 454 455 CONFIG_SYS_FSL_DDR3 456 Board config to use DDR3. It can be enabled for SoCs with 457 Freescale DDR3 or DDR3L controllers. 458 459 CONFIG_SYS_FSL_DDR3L 460 Board config to use DDR3L. It can be enabled for SoCs with 461 DDR3L controllers. 462 463 CONFIG_SYS_FSL_DDR4 464 Board config to use DDR4. It can be enabled for SoCs with 465 DDR4 controllers. 466 467 CONFIG_SYS_FSL_IFC_BE 468 Defines the IFC controller register space as Big Endian 469 470 CONFIG_SYS_FSL_IFC_LE 471 Defines the IFC controller register space as Little Endian 472 473 CONFIG_SYS_FSL_IFC_CLK_DIV 474 Defines divider of platform clock(clock input to IFC controller). 475 476 CONFIG_SYS_FSL_LBC_CLK_DIV 477 Defines divider of platform clock(clock input to eLBC controller). 478 479 CONFIG_SYS_FSL_PBL_PBI 480 It enables addition of RCW (Power on reset configuration) in built image. 481 Please refer doc/README.pblimage for more details 482 483 CONFIG_SYS_FSL_PBL_RCW 484 It adds PBI(pre-boot instructions) commands in u-boot build image. 485 PBI commands can be used to configure SoC before it starts the execution. 486 Please refer doc/README.pblimage for more details 487 488 CONFIG_SPL_FSL_PBL 489 It adds a target to create boot binary having SPL binary in PBI format 490 concatenated with u-boot binary. 491 492 CONFIG_SYS_FSL_DDR_BE 493 Defines the DDR controller register space as Big Endian 494 495 CONFIG_SYS_FSL_DDR_LE 496 Defines the DDR controller register space as Little Endian 497 498 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 499 Physical address from the view of DDR controllers. It is the 500 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 501 it could be different for ARM SoCs. 502 503 CONFIG_SYS_FSL_DDR_INTLV_256B 504 DDR controller interleaving on 256-byte. This is a special 505 interleaving mode, handled by Dickens for Freescale layerscape 506 SoCs with ARM core. 507 508 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 509 Number of controllers used as main memory. 510 511 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 512 Number of controllers used for other than main memory. 513 514 CONFIG_SYS_FSL_HAS_DP_DDR 515 Defines the SoC has DP-DDR used for DPAA. 516 517 CONFIG_SYS_FSL_SEC_BE 518 Defines the SEC controller register space as Big Endian 519 520 CONFIG_SYS_FSL_SEC_LE 521 Defines the SEC controller register space as Little Endian 522 523- MIPS CPU options: 524 CONFIG_SYS_INIT_SP_OFFSET 525 526 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 527 pointer. This is needed for the temporary stack before 528 relocation. 529 530 CONFIG_SYS_MIPS_CACHE_MODE 531 532 Cache operation mode for the MIPS CPU. 533 See also arch/mips/include/asm/mipsregs.h. 534 Possible values are: 535 CONF_CM_CACHABLE_NO_WA 536 CONF_CM_CACHABLE_WA 537 CONF_CM_UNCACHED 538 CONF_CM_CACHABLE_NONCOHERENT 539 CONF_CM_CACHABLE_CE 540 CONF_CM_CACHABLE_COW 541 CONF_CM_CACHABLE_CUW 542 CONF_CM_CACHABLE_ACCELERATED 543 544 CONFIG_SYS_XWAY_EBU_BOOTCFG 545 546 Special option for Lantiq XWAY SoCs for booting from NOR flash. 547 See also arch/mips/cpu/mips32/start.S. 548 549 CONFIG_XWAY_SWAP_BYTES 550 551 Enable compilation of tools/xway-swap-bytes needed for Lantiq 552 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 553 be swapped if a flash programmer is used. 554 555- ARM options: 556 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 557 558 Select high exception vectors of the ARM core, e.g., do not 559 clear the V bit of the c1 register of CP15. 560 561 COUNTER_FREQUENCY 562 Generic timer clock source frequency. 563 564 COUNTER_FREQUENCY_REAL 565 Generic timer clock source frequency if the real clock is 566 different from COUNTER_FREQUENCY, and can only be determined 567 at run time. 568 569- Tegra SoC options: 570 CONFIG_TEGRA_SUPPORT_NON_SECURE 571 572 Support executing U-Boot in non-secure (NS) mode. Certain 573 impossible actions will be skipped if the CPU is in NS mode, 574 such as ARM architectural timer initialization. 575 576- Linux Kernel Interface: 577 CONFIG_CLOCKS_IN_MHZ 578 579 U-Boot stores all clock information in Hz 580 internally. For binary compatibility with older Linux 581 kernels (which expect the clocks passed in the 582 bd_info data to be in MHz) the environment variable 583 "clocks_in_mhz" can be defined so that U-Boot 584 converts clock data to MHZ before passing it to the 585 Linux kernel. 586 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 587 "clocks_in_mhz=1" is automatically included in the 588 default environment. 589 590 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 591 592 When transferring memsize parameter to Linux, some versions 593 expect it to be in bytes, others in MB. 594 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 595 596 CONFIG_OF_LIBFDT 597 598 New kernel versions are expecting firmware settings to be 599 passed using flattened device trees (based on open firmware 600 concepts). 601 602 CONFIG_OF_LIBFDT 603 * New libfdt-based support 604 * Adds the "fdt" command 605 * The bootm command automatically updates the fdt 606 607 OF_TBCLK - The timebase frequency. 608 OF_STDOUT_PATH - The path to the console device 609 610 boards with QUICC Engines require OF_QE to set UCC MAC 611 addresses 612 613 CONFIG_OF_BOARD_SETUP 614 615 Board code has addition modification that it wants to make 616 to the flat device tree before handing it off to the kernel 617 618 CONFIG_OF_SYSTEM_SETUP 619 620 Other code has addition modification that it wants to make 621 to the flat device tree before handing it off to the kernel. 622 This causes ft_system_setup() to be called before booting 623 the kernel. 624 625 CONFIG_OF_IDE_FIXUP 626 627 U-Boot can detect if an IDE device is present or not. 628 If not, and this new config option is activated, U-Boot 629 removes the ATA node from the DTS before booting Linux, 630 so the Linux IDE driver does not probe the device and 631 crash. This is needed for buggy hardware (uc101) where 632 no pull down resistor is connected to the signal IDE5V_DD7. 633 634 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 635 636 This setting is mandatory for all boards that have only one 637 machine type and must be used to specify the machine type 638 number as it appears in the ARM machine registry 639 (see http://www.arm.linux.org.uk/developer/machines/). 640 Only boards that have multiple machine types supported 641 in a single configuration file and the machine type is 642 runtime discoverable, do not have to use this setting. 643 644- vxWorks boot parameters: 645 646 bootvx constructs a valid bootline using the following 647 environments variables: bootdev, bootfile, ipaddr, netmask, 648 serverip, gatewayip, hostname, othbootargs. 649 It loads the vxWorks image pointed bootfile. 650 651 Note: If a "bootargs" environment is defined, it will overwride 652 the defaults discussed just above. 653 654- Cache Configuration: 655 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 656 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 657 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 658 659- Cache Configuration for ARM: 660 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 661 controller 662 CONFIG_SYS_PL310_BASE - Physical base address of PL310 663 controller register space 664 665- Serial Ports: 666 CONFIG_PL010_SERIAL 667 668 Define this if you want support for Amba PrimeCell PL010 UARTs. 669 670 CONFIG_PL011_SERIAL 671 672 Define this if you want support for Amba PrimeCell PL011 UARTs. 673 674 CONFIG_PL011_CLOCK 675 676 If you have Amba PrimeCell PL011 UARTs, set this variable to 677 the clock speed of the UARTs. 678 679 CONFIG_PL01x_PORTS 680 681 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 682 define this to a list of base addresses for each (supported) 683 port. See e.g. include/configs/versatile.h 684 685 CONFIG_SERIAL_HW_FLOW_CONTROL 686 687 Define this variable to enable hw flow control in serial driver. 688 Current user of this option is drivers/serial/nsl16550.c driver 689 690- Console Baudrate: 691 CONFIG_BAUDRATE - in bps 692 Select one of the baudrates listed in 693 CONFIG_SYS_BAUDRATE_TABLE, see below. 694 695- Autoboot Command: 696 CONFIG_BOOTCOMMAND 697 Only needed when CONFIG_BOOTDELAY is enabled; 698 define a command string that is automatically executed 699 when no character is read on the console interface 700 within "Boot Delay" after reset. 701 702 CONFIG_BOOTARGS 703 This can be used to pass arguments to the bootm 704 command. The value of CONFIG_BOOTARGS goes into the 705 environment value "bootargs". 706 707 CONFIG_RAMBOOT and CONFIG_NFSBOOT 708 The value of these goes into the environment as 709 "ramboot" and "nfsboot" respectively, and can be used 710 as a convenience, when switching between booting from 711 RAM and NFS. 712 713- Bootcount: 714 CONFIG_BOOTCOUNT_LIMIT 715 Implements a mechanism for detecting a repeating reboot 716 cycle, see: 717 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit 718 719 CONFIG_BOOTCOUNT_ENV 720 If no softreset save registers are found on the hardware 721 "bootcount" is stored in the environment. To prevent a 722 saveenv on all reboots, the environment variable 723 "upgrade_available" is used. If "upgrade_available" is 724 0, "bootcount" is always 0, if "upgrade_available" is 725 1 "bootcount" is incremented in the environment. 726 So the Userspace Applikation must set the "upgrade_available" 727 and "bootcount" variable to 0, if a boot was successfully. 728 729- Pre-Boot Commands: 730 CONFIG_PREBOOT 731 732 When this option is #defined, the existence of the 733 environment variable "preboot" will be checked 734 immediately before starting the CONFIG_BOOTDELAY 735 countdown and/or running the auto-boot command resp. 736 entering interactive mode. 737 738 This feature is especially useful when "preboot" is 739 automatically generated or modified. For an example 740 see the LWMON board specific code: here "preboot" is 741 modified when the user holds down a certain 742 combination of keys on the (special) keyboard when 743 booting the systems 744 745- Serial Download Echo Mode: 746 CONFIG_LOADS_ECHO 747 If defined to 1, all characters received during a 748 serial download (using the "loads" command) are 749 echoed back. This might be needed by some terminal 750 emulations (like "cu"), but may as well just take 751 time on others. This setting #define's the initial 752 value of the "loads_echo" environment variable. 753 754- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 755 CONFIG_KGDB_BAUDRATE 756 Select one of the baudrates listed in 757 CONFIG_SYS_BAUDRATE_TABLE, see below. 758 759- Monitor Functions: 760 Monitor commands can be included or excluded 761 from the build by using the #include files 762 <config_cmd_all.h> and #undef'ing unwanted 763 commands, or adding #define's for wanted commands. 764 765 The default command configuration includes all commands 766 except those marked below with a "*". 767 768 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt 769 CONFIG_CMD_ASKENV * ask for env variable 770 CONFIG_CMD_BDI bdinfo 771 CONFIG_CMD_BOOTD bootd 772 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support 773 CONFIG_CMD_CACHE * icache, dcache 774 CONFIG_CMD_CONSOLE coninfo 775 CONFIG_CMD_DHCP * DHCP support 776 CONFIG_CMD_DIAG * Diagnostics 777 CONFIG_CMD_ECHO echo arguments 778 CONFIG_CMD_EDITENV edit env variable 779 CONFIG_CMD_ELF * bootelf, bootvx 780 CONFIG_CMD_ENV_EXISTS * check existence of env variable 781 CONFIG_CMD_EXPORTENV * export the environment 782 CONFIG_CMD_EXT2 * ext2 command support 783 CONFIG_CMD_EXT4 * ext4 command support 784 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls) 785 that work for multiple fs types 786 CONFIG_CMD_FS_UUID * Look up a filesystem UUID 787 CONFIG_CMD_SAVEENV saveenv 788 CONFIG_CMD_FLASH flinfo, erase, protect 789 CONFIG_CMD_FPGA FPGA device initialization support 790 CONFIG_CMD_GO * the 'go' command (exec code) 791 CONFIG_CMD_GREPENV * search environment 792 CONFIG_CMD_I2C * I2C serial bus support 793 CONFIG_CMD_IMI iminfo 794 CONFIG_CMD_IMLS List all images found in NOR flash 795 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash 796 CONFIG_CMD_IMPORTENV * import an environment 797 CONFIG_CMD_INI * import data from an ini file into the env 798 CONFIG_CMD_ITEST Integer/string test of 2 values 799 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader) 800 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration 801 (169.254.*.*) 802 CONFIG_CMD_LOADB loadb 803 CONFIG_CMD_LOADS loads 804 CONFIG_CMD_MD5SUM * print md5 message digest 805 (requires CONFIG_CMD_MEMORY and CONFIG_MD5) 806 CONFIG_CMD_MEMINFO * Display detailed memory information 807 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base, 808 loop, loopw 809 CONFIG_CMD_MEMTEST * mtest 810 CONFIG_CMD_MISC Misc functions like sleep etc 811 CONFIG_CMD_MMC * MMC memory mapped support 812 CONFIG_CMD_MII * MII utility commands 813 CONFIG_CMD_MTDPARTS * MTD partition support 814 CONFIG_CMD_NAND * NAND support 815 CONFIG_CMD_NET bootp, tftpboot, rarpboot 816 CONFIG_CMD_NFS NFS support 817 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 818 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 819 CONFIG_CMD_PCI * pciinfo 820 CONFIG_CMD_PCMCIA * PCMCIA support 821 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 822 host 823 CONFIG_CMD_PORTIO * Port I/O 824 CONFIG_CMD_READ * Read raw data from partition 825 CONFIG_CMD_REGINFO * Register dump 826 CONFIG_CMD_RUN run command in env variable 827 CONFIG_CMD_SANDBOX * sb command to access sandbox features 828 CONFIG_CMD_SAVES * save S record dump 829 CONFIG_SCSI * SCSI Support 830 CONFIG_CMD_SDRAM * print SDRAM configuration information 831 (requires CONFIG_CMD_I2C) 832 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 833 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 834 CONFIG_CMD_SOURCE "source" command Support 835 CONFIG_CMD_SPI * SPI serial bus support 836 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 837 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 838 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 839 CONFIG_CMD_TIMER * access to the system tick timer 840 CONFIG_CMD_USB * USB support 841 CONFIG_CMD_CDP * Cisco Discover Protocol support 842 CONFIG_CMD_MFSL * Microblaze FSL support 843 CONFIG_CMD_XIMG Load part of Multi Image 844 CONFIG_CMD_UUID * Generate random UUID or GUID string 845 846 EXAMPLE: If you want all functions except of network 847 support you can write: 848 849 #include "config_cmd_all.h" 850 #undef CONFIG_CMD_NET 851 852 Other Commands: 853 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 854 855 Note: Don't enable the "icache" and "dcache" commands 856 (configuration option CONFIG_CMD_CACHE) unless you know 857 what you (and your U-Boot users) are doing. Data 858 cache cannot be enabled on systems like the 859 8260 (where accesses to the IMMR region must be 860 uncached), and it cannot be disabled on all other 861 systems where we (mis-) use the data cache to hold an 862 initial stack and some data. 863 864 865 XXX - this list needs to get updated! 866 867- Removal of commands 868 If no commands are needed to boot, you can disable 869 CONFIG_CMDLINE to remove them. In this case, the command line 870 will not be available, and when U-Boot wants to execute the 871 boot command (on start-up) it will call board_run_command() 872 instead. This can reduce image size significantly for very 873 simple boot procedures. 874 875- Regular expression support: 876 CONFIG_REGEX 877 If this variable is defined, U-Boot is linked against 878 the SLRE (Super Light Regular Expression) library, 879 which adds regex support to some commands, as for 880 example "env grep" and "setexpr". 881 882- Device tree: 883 CONFIG_OF_CONTROL 884 If this variable is defined, U-Boot will use a device tree 885 to configure its devices, instead of relying on statically 886 compiled #defines in the board file. This option is 887 experimental and only available on a few boards. The device 888 tree is available in the global data as gd->fdt_blob. 889 890 U-Boot needs to get its device tree from somewhere. This can 891 be done using one of the three options below: 892 893 CONFIG_OF_EMBED 894 If this variable is defined, U-Boot will embed a device tree 895 binary in its image. This device tree file should be in the 896 board directory and called <soc>-<board>.dts. The binary file 897 is then picked up in board_init_f() and made available through 898 the global data structure as gd->blob. 899 900 CONFIG_OF_SEPARATE 901 If this variable is defined, U-Boot will build a device tree 902 binary. It will be called u-boot.dtb. Architecture-specific 903 code will locate it at run-time. Generally this works by: 904 905 cat u-boot.bin u-boot.dtb >image.bin 906 907 and in fact, U-Boot does this for you, creating a file called 908 u-boot-dtb.bin which is useful in the common case. You can 909 still use the individual files if you need something more 910 exotic. 911 912 CONFIG_OF_BOARD 913 If this variable is defined, U-Boot will use the device tree 914 provided by the board at runtime instead of embedding one with 915 the image. Only boards defining board_fdt_blob_setup() support 916 this option (see include/fdtdec.h file). 917 918- Watchdog: 919 CONFIG_WATCHDOG 920 If this variable is defined, it enables watchdog 921 support for the SoC. There must be support in the SoC 922 specific code for a watchdog. When supported for a 923 specific SoC is available, then no further board specific 924 code should be needed to use it. 925 926 CONFIG_HW_WATCHDOG 927 When using a watchdog circuitry external to the used 928 SoC, then define this variable and provide board 929 specific code for the "hw_watchdog_reset" function. 930 931 CONFIG_AT91_HW_WDT_TIMEOUT 932 specify the timeout in seconds. default 2 seconds. 933 934- U-Boot Version: 935 CONFIG_VERSION_VARIABLE 936 If this variable is defined, an environment variable 937 named "ver" is created by U-Boot showing the U-Boot 938 version as printed by the "version" command. 939 Any change to this variable will be reverted at the 940 next reset. 941 942- Real-Time Clock: 943 944 When CONFIG_CMD_DATE is selected, the type of the RTC 945 has to be selected, too. Define exactly one of the 946 following options: 947 948 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 949 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 950 CONFIG_RTC_MC146818 - use MC146818 RTC 951 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 952 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 953 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 954 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 955 CONFIG_RTC_DS164x - use Dallas DS164x RTC 956 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 957 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 958 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 959 CONFIG_SYS_RV3029_TCR - enable trickle charger on 960 RV3029 RTC. 961 962 Note that if the RTC uses I2C, then the I2C interface 963 must also be configured. See I2C Support, below. 964 965- GPIO Support: 966 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 967 968 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 969 chip-ngpio pairs that tell the PCA953X driver the number of 970 pins supported by a particular chip. 971 972 Note that if the GPIO device uses I2C, then the I2C interface 973 must also be configured. See I2C Support, below. 974 975- I/O tracing: 976 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 977 accesses and can checksum them or write a list of them out 978 to memory. See the 'iotrace' command for details. This is 979 useful for testing device drivers since it can confirm that 980 the driver behaves the same way before and after a code 981 change. Currently this is supported on sandbox and arm. To 982 add support for your architecture, add '#include <iotrace.h>' 983 to the bottom of arch/<arch>/include/asm/io.h and test. 984 985 Example output from the 'iotrace stats' command is below. 986 Note that if the trace buffer is exhausted, the checksum will 987 still continue to operate. 988 989 iotrace is enabled 990 Start: 10000000 (buffer start address) 991 Size: 00010000 (buffer size) 992 Offset: 00000120 (current buffer offset) 993 Output: 10000120 (start + offset) 994 Count: 00000018 (number of trace records) 995 CRC32: 9526fb66 (CRC32 of all trace records) 996 997- Timestamp Support: 998 999 When CONFIG_TIMESTAMP is selected, the timestamp 1000 (date and time) of an image is printed by image 1001 commands like bootm or iminfo. This option is 1002 automatically enabled when you select CONFIG_CMD_DATE . 1003 1004- Partition Labels (disklabels) Supported: 1005 Zero or more of the following: 1006 CONFIG_MAC_PARTITION Apple's MacOS partition table. 1007 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 1008 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 1009 bootloader. Note 2TB partition limit; see 1010 disk/part_efi.c 1011 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 1012 1013 If IDE or SCSI support is enabled (CONFIG_IDE or 1014 CONFIG_SCSI) you must configure support for at 1015 least one non-MTD partition type as well. 1016 1017- IDE Reset method: 1018 CONFIG_IDE_RESET_ROUTINE - this is defined in several 1019 board configurations files but used nowhere! 1020 1021 CONFIG_IDE_RESET - is this is defined, IDE Reset will 1022 be performed by calling the function 1023 ide_set_reset(int reset) 1024 which has to be defined in a board specific file 1025 1026- ATAPI Support: 1027 CONFIG_ATAPI 1028 1029 Set this to enable ATAPI support. 1030 1031- LBA48 Support 1032 CONFIG_LBA48 1033 1034 Set this to enable support for disks larger than 137GB 1035 Also look at CONFIG_SYS_64BIT_LBA. 1036 Whithout these , LBA48 support uses 32bit variables and will 'only' 1037 support disks up to 2.1TB. 1038 1039 CONFIG_SYS_64BIT_LBA: 1040 When enabled, makes the IDE subsystem use 64bit sector addresses. 1041 Default is 32bit. 1042 1043- SCSI Support: 1044 At the moment only there is only support for the 1045 SYM53C8XX SCSI controller; define 1046 CONFIG_SCSI_SYM53C8XX to enable it. 1047 1048 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1049 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1050 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1051 maximum numbers of LUNs, SCSI ID's and target 1052 devices. 1053 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz) 1054 1055 The environment variable 'scsidevs' is set to the number of 1056 SCSI devices found during the last scan. 1057 1058- NETWORK Support (PCI): 1059 CONFIG_E1000 1060 Support for Intel 8254x/8257x gigabit chips. 1061 1062 CONFIG_E1000_SPI 1063 Utility code for direct access to the SPI bus on Intel 8257x. 1064 This does not do anything useful unless you set at least one 1065 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1066 1067 CONFIG_E1000_SPI_GENERIC 1068 Allow generic access to the SPI bus on the Intel 8257x, for 1069 example with the "sspi" command. 1070 1071 CONFIG_CMD_E1000 1072 Management command for E1000 devices. When used on devices 1073 with SPI support you can reprogram the EEPROM from U-Boot. 1074 1075 CONFIG_EEPRO100 1076 Support for Intel 82557/82559/82559ER chips. 1077 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1078 write routine for first time initialisation. 1079 1080 CONFIG_TULIP 1081 Support for Digital 2114x chips. 1082 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1083 modem chip initialisation (KS8761/QS6611). 1084 1085 CONFIG_NATSEMI 1086 Support for National dp83815 chips. 1087 1088 CONFIG_NS8382X 1089 Support for National dp8382[01] gigabit chips. 1090 1091- NETWORK Support (other): 1092 1093 CONFIG_DRIVER_AT91EMAC 1094 Support for AT91RM9200 EMAC. 1095 1096 CONFIG_RMII 1097 Define this to use reduced MII inteface 1098 1099 CONFIG_DRIVER_AT91EMAC_QUIET 1100 If this defined, the driver is quiet. 1101 The driver doen't show link status messages. 1102 1103 CONFIG_CALXEDA_XGMAC 1104 Support for the Calxeda XGMAC device 1105 1106 CONFIG_LAN91C96 1107 Support for SMSC's LAN91C96 chips. 1108 1109 CONFIG_LAN91C96_USE_32_BIT 1110 Define this to enable 32 bit addressing 1111 1112 CONFIG_SMC91111 1113 Support for SMSC's LAN91C111 chip 1114 1115 CONFIG_SMC91111_BASE 1116 Define this to hold the physical address 1117 of the device (I/O space) 1118 1119 CONFIG_SMC_USE_32_BIT 1120 Define this if data bus is 32 bits 1121 1122 CONFIG_SMC_USE_IOFUNCS 1123 Define this to use i/o functions instead of macros 1124 (some hardware wont work with macros) 1125 1126 CONFIG_DRIVER_TI_EMAC 1127 Support for davinci emac 1128 1129 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1130 Define this if you have more then 3 PHYs. 1131 1132 CONFIG_FTGMAC100 1133 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1134 1135 CONFIG_FTGMAC100_EGIGA 1136 Define this to use GE link update with gigabit PHY. 1137 Define this if FTGMAC100 is connected to gigabit PHY. 1138 If your system has 10/100 PHY only, it might not occur 1139 wrong behavior. Because PHY usually return timeout or 1140 useless data when polling gigabit status and gigabit 1141 control registers. This behavior won't affect the 1142 correctnessof 10/100 link speed update. 1143 1144 CONFIG_SMC911X 1145 Support for SMSC's LAN911x and LAN921x chips 1146 1147 CONFIG_SMC911X_BASE 1148 Define this to hold the physical address 1149 of the device (I/O space) 1150 1151 CONFIG_SMC911X_32_BIT 1152 Define this if data bus is 32 bits 1153 1154 CONFIG_SMC911X_16_BIT 1155 Define this if data bus is 16 bits. If your processor 1156 automatically converts one 32 bit word to two 16 bit 1157 words you may also try CONFIG_SMC911X_32_BIT. 1158 1159 CONFIG_SH_ETHER 1160 Support for Renesas on-chip Ethernet controller 1161 1162 CONFIG_SH_ETHER_USE_PORT 1163 Define the number of ports to be used 1164 1165 CONFIG_SH_ETHER_PHY_ADDR 1166 Define the ETH PHY's address 1167 1168 CONFIG_SH_ETHER_CACHE_WRITEBACK 1169 If this option is set, the driver enables cache flush. 1170 1171- PWM Support: 1172 CONFIG_PWM_IMX 1173 Support for PWM module on the imx6. 1174 1175- TPM Support: 1176 CONFIG_TPM 1177 Support TPM devices. 1178 1179 CONFIG_TPM_TIS_INFINEON 1180 Support for Infineon i2c bus TPM devices. Only one device 1181 per system is supported at this time. 1182 1183 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1184 Define the burst count bytes upper limit 1185 1186 CONFIG_TPM_ST33ZP24 1187 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1188 1189 CONFIG_TPM_ST33ZP24_I2C 1190 Support for STMicroelectronics ST33ZP24 I2C devices. 1191 Requires TPM_ST33ZP24 and I2C. 1192 1193 CONFIG_TPM_ST33ZP24_SPI 1194 Support for STMicroelectronics ST33ZP24 SPI devices. 1195 Requires TPM_ST33ZP24 and SPI. 1196 1197 CONFIG_TPM_ATMEL_TWI 1198 Support for Atmel TWI TPM device. Requires I2C support. 1199 1200 CONFIG_TPM_TIS_LPC 1201 Support for generic parallel port TPM devices. Only one device 1202 per system is supported at this time. 1203 1204 CONFIG_TPM_TIS_BASE_ADDRESS 1205 Base address where the generic TPM device is mapped 1206 to. Contemporary x86 systems usually map it at 1207 0xfed40000. 1208 1209 CONFIG_CMD_TPM 1210 Add tpm monitor functions. 1211 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1212 provides monitor access to authorized functions. 1213 1214 CONFIG_TPM 1215 Define this to enable the TPM support library which provides 1216 functional interfaces to some TPM commands. 1217 Requires support for a TPM device. 1218 1219 CONFIG_TPM_AUTH_SESSIONS 1220 Define this to enable authorized functions in the TPM library. 1221 Requires CONFIG_TPM and CONFIG_SHA1. 1222 1223- USB Support: 1224 At the moment only the UHCI host controller is 1225 supported (PIP405, MIP405); define 1226 CONFIG_USB_UHCI to enable it. 1227 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1228 and define CONFIG_USB_STORAGE to enable the USB 1229 storage devices. 1230 Note: 1231 Supported are USB Keyboards and USB Floppy drives 1232 (TEAC FD-05PUB). 1233 1234 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1235 txfilltuning field in the EHCI controller on reset. 1236 1237 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1238 HW module registers. 1239 1240- USB Device: 1241 Define the below if you wish to use the USB console. 1242 Once firmware is rebuilt from a serial console issue the 1243 command "setenv stdin usbtty; setenv stdout usbtty" and 1244 attach your USB cable. The Unix command "dmesg" should print 1245 it has found a new device. The environment variable usbtty 1246 can be set to gserial or cdc_acm to enable your device to 1247 appear to a USB host as a Linux gserial device or a 1248 Common Device Class Abstract Control Model serial device. 1249 If you select usbtty = gserial you should be able to enumerate 1250 a Linux host by 1251 # modprobe usbserial vendor=0xVendorID product=0xProductID 1252 else if using cdc_acm, simply setting the environment 1253 variable usbtty to be cdc_acm should suffice. The following 1254 might be defined in YourBoardName.h 1255 1256 CONFIG_USB_DEVICE 1257 Define this to build a UDC device 1258 1259 CONFIG_USB_TTY 1260 Define this to have a tty type of device available to 1261 talk to the UDC device 1262 1263 CONFIG_USBD_HS 1264 Define this to enable the high speed support for usb 1265 device and usbtty. If this feature is enabled, a routine 1266 int is_usbd_high_speed(void) 1267 also needs to be defined by the driver to dynamically poll 1268 whether the enumeration has succeded at high speed or full 1269 speed. 1270 1271 CONFIG_SYS_CONSOLE_IS_IN_ENV 1272 Define this if you want stdin, stdout &/or stderr to 1273 be set to usbtty. 1274 1275 If you have a USB-IF assigned VendorID then you may wish to 1276 define your own vendor specific values either in BoardName.h 1277 or directly in usbd_vendor_info.h. If you don't define 1278 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1279 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1280 should pretend to be a Linux device to it's target host. 1281 1282 CONFIG_USBD_MANUFACTURER 1283 Define this string as the name of your company for 1284 - CONFIG_USBD_MANUFACTURER "my company" 1285 1286 CONFIG_USBD_PRODUCT_NAME 1287 Define this string as the name of your product 1288 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1289 1290 CONFIG_USBD_VENDORID 1291 Define this as your assigned Vendor ID from the USB 1292 Implementors Forum. This *must* be a genuine Vendor ID 1293 to avoid polluting the USB namespace. 1294 - CONFIG_USBD_VENDORID 0xFFFF 1295 1296 CONFIG_USBD_PRODUCTID 1297 Define this as the unique Product ID 1298 for your device 1299 - CONFIG_USBD_PRODUCTID 0xFFFF 1300 1301- ULPI Layer Support: 1302 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1303 the generic ULPI layer. The generic layer accesses the ULPI PHY 1304 via the platform viewport, so you need both the genric layer and 1305 the viewport enabled. Currently only Chipidea/ARC based 1306 viewport is supported. 1307 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1308 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1309 If your ULPI phy needs a different reference clock than the 1310 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1311 the appropriate value in Hz. 1312 1313- MMC Support: 1314 The MMC controller on the Intel PXA is supported. To 1315 enable this define CONFIG_MMC. The MMC can be 1316 accessed from the boot prompt by mapping the device 1317 to physical memory similar to flash. Command line is 1318 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1319 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1320 1321 CONFIG_SH_MMCIF 1322 Support for Renesas on-chip MMCIF controller 1323 1324 CONFIG_SH_MMCIF_ADDR 1325 Define the base address of MMCIF registers 1326 1327 CONFIG_SH_MMCIF_CLK 1328 Define the clock frequency for MMCIF 1329 1330 CONFIG_SUPPORT_EMMC_BOOT 1331 Enable some additional features of the eMMC boot partitions. 1332 1333 CONFIG_SUPPORT_EMMC_RPMB 1334 Enable the commands for reading, writing and programming the 1335 key for the Replay Protection Memory Block partition in eMMC. 1336 1337- USB Device Firmware Update (DFU) class support: 1338 CONFIG_USB_FUNCTION_DFU 1339 This enables the USB portion of the DFU USB class 1340 1341 CONFIG_CMD_DFU 1342 This enables the command "dfu" which is used to have 1343 U-Boot create a DFU class device via USB. This command 1344 requires that the "dfu_alt_info" environment variable be 1345 set and define the alt settings to expose to the host. 1346 1347 CONFIG_DFU_MMC 1348 This enables support for exposing (e)MMC devices via DFU. 1349 1350 CONFIG_DFU_NAND 1351 This enables support for exposing NAND devices via DFU. 1352 1353 CONFIG_DFU_RAM 1354 This enables support for exposing RAM via DFU. 1355 Note: DFU spec refer to non-volatile memory usage, but 1356 allow usages beyond the scope of spec - here RAM usage, 1357 one that would help mostly the developer. 1358 1359 CONFIG_SYS_DFU_DATA_BUF_SIZE 1360 Dfu transfer uses a buffer before writing data to the 1361 raw storage device. Make the size (in bytes) of this buffer 1362 configurable. The size of this buffer is also configurable 1363 through the "dfu_bufsiz" environment variable. 1364 1365 CONFIG_SYS_DFU_MAX_FILE_SIZE 1366 When updating files rather than the raw storage device, 1367 we use a static buffer to copy the file into and then write 1368 the buffer once we've been given the whole file. Define 1369 this to the maximum filesize (in bytes) for the buffer. 1370 Default is 4 MiB if undefined. 1371 1372 DFU_DEFAULT_POLL_TIMEOUT 1373 Poll timeout [ms], is the timeout a device can send to the 1374 host. The host must wait for this timeout before sending 1375 a subsequent DFU_GET_STATUS request to the device. 1376 1377 DFU_MANIFEST_POLL_TIMEOUT 1378 Poll timeout [ms], which the device sends to the host when 1379 entering dfuMANIFEST state. Host waits this timeout, before 1380 sending again an USB request to the device. 1381 1382- USB Device Android Fastboot support: 1383 CONFIG_USB_FUNCTION_FASTBOOT 1384 This enables the USB part of the fastboot gadget 1385 1386 CONFIG_CMD_FASTBOOT 1387 This enables the command "fastboot" which enables the Android 1388 fastboot mode for the platform's USB device. Fastboot is a USB 1389 protocol for downloading images, flashing and device control 1390 used on Android devices. 1391 See doc/README.android-fastboot for more information. 1392 1393 CONFIG_ANDROID_BOOT_IMAGE 1394 This enables support for booting images which use the Android 1395 image format header. 1396 1397 CONFIG_FASTBOOT_BUF_ADDR 1398 The fastboot protocol requires a large memory buffer for 1399 downloads. Define this to the starting RAM address to use for 1400 downloaded images. 1401 1402 CONFIG_FASTBOOT_BUF_SIZE 1403 The fastboot protocol requires a large memory buffer for 1404 downloads. This buffer should be as large as possible for a 1405 platform. Define this to the size available RAM for fastboot. 1406 1407 CONFIG_FASTBOOT_FLASH 1408 The fastboot protocol includes a "flash" command for writing 1409 the downloaded image to a non-volatile storage device. Define 1410 this to enable the "fastboot flash" command. 1411 1412 CONFIG_FASTBOOT_FLASH_MMC_DEV 1413 The fastboot "flash" command requires additional information 1414 regarding the non-volatile storage device. Define this to 1415 the eMMC device that fastboot should use to store the image. 1416 1417 CONFIG_FASTBOOT_GPT_NAME 1418 The fastboot "flash" command supports writing the downloaded 1419 image to the Protective MBR and the Primary GUID Partition 1420 Table. (Additionally, this downloaded image is post-processed 1421 to generate and write the Backup GUID Partition Table.) 1422 This occurs when the specified "partition name" on the 1423 "fastboot flash" command line matches this value. 1424 The default is "gpt" if undefined. 1425 1426 CONFIG_FASTBOOT_MBR_NAME 1427 The fastboot "flash" command supports writing the downloaded 1428 image to DOS MBR. 1429 This occurs when the "partition name" specified on the 1430 "fastboot flash" command line matches this value. 1431 If not defined the default value "mbr" is used. 1432 1433- Journaling Flash filesystem support: 1434 CONFIG_JFFS2_NAND 1435 Define these for a default partition on a NAND device 1436 1437 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1438 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1439 Define these for a default partition on a NOR device 1440 1441- Keyboard Support: 1442 See Kconfig help for available keyboard drivers. 1443 1444 CONFIG_KEYBOARD 1445 1446 Define this to enable a custom keyboard support. 1447 This simply calls drv_keyboard_init() which must be 1448 defined in your board-specific files. This option is deprecated 1449 and is only used by novena. For new boards, use driver model 1450 instead. 1451 1452- Video support: 1453 CONFIG_FSL_DIU_FB 1454 Enable the Freescale DIU video driver. Reference boards for 1455 SOCs that have a DIU should define this macro to enable DIU 1456 support, and should also define these other macros: 1457 1458 CONFIG_SYS_DIU_ADDR 1459 CONFIG_VIDEO 1460 CONFIG_CFB_CONSOLE 1461 CONFIG_VIDEO_SW_CURSOR 1462 CONFIG_VGA_AS_SINGLE_DEVICE 1463 CONFIG_VIDEO_LOGO 1464 CONFIG_VIDEO_BMP_LOGO 1465 1466 The DIU driver will look for the 'video-mode' environment 1467 variable, and if defined, enable the DIU as a console during 1468 boot. See the documentation file doc/README.video for a 1469 description of this variable. 1470 1471- LCD Support: CONFIG_LCD 1472 1473 Define this to enable LCD support (for output to LCD 1474 display); also select one of the supported displays 1475 by defining one of these: 1476 1477 CONFIG_ATMEL_LCD: 1478 1479 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1480 1481 CONFIG_NEC_NL6448AC33: 1482 1483 NEC NL6448AC33-18. Active, color, single scan. 1484 1485 CONFIG_NEC_NL6448BC20 1486 1487 NEC NL6448BC20-08. 6.5", 640x480. 1488 Active, color, single scan. 1489 1490 CONFIG_NEC_NL6448BC33_54 1491 1492 NEC NL6448BC33-54. 10.4", 640x480. 1493 Active, color, single scan. 1494 1495 CONFIG_SHARP_16x9 1496 1497 Sharp 320x240. Active, color, single scan. 1498 It isn't 16x9, and I am not sure what it is. 1499 1500 CONFIG_SHARP_LQ64D341 1501 1502 Sharp LQ64D341 display, 640x480. 1503 Active, color, single scan. 1504 1505 CONFIG_HLD1045 1506 1507 HLD1045 display, 640x480. 1508 Active, color, single scan. 1509 1510 CONFIG_OPTREX_BW 1511 1512 Optrex CBL50840-2 NF-FW 99 22 M5 1513 or 1514 Hitachi LMG6912RPFC-00T 1515 or 1516 Hitachi SP14Q002 1517 1518 320x240. Black & white. 1519 1520 CONFIG_LCD_ALIGNMENT 1521 1522 Normally the LCD is page-aligned (typically 4KB). If this is 1523 defined then the LCD will be aligned to this value instead. 1524 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1525 here, since it is cheaper to change data cache settings on 1526 a per-section basis. 1527 1528 1529 CONFIG_LCD_ROTATION 1530 1531 Sometimes, for example if the display is mounted in portrait 1532 mode or even if it's mounted landscape but rotated by 180degree, 1533 we need to rotate our content of the display relative to the 1534 framebuffer, so that user can read the messages which are 1535 printed out. 1536 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1537 initialized with a given rotation from "vl_rot" out of 1538 "vidinfo_t" which is provided by the board specific code. 1539 The value for vl_rot is coded as following (matching to 1540 fbcon=rotate:<n> linux-kernel commandline): 1541 0 = no rotation respectively 0 degree 1542 1 = 90 degree rotation 1543 2 = 180 degree rotation 1544 3 = 270 degree rotation 1545 1546 If CONFIG_LCD_ROTATION is not defined, the console will be 1547 initialized with 0degree rotation. 1548 1549 CONFIG_LCD_BMP_RLE8 1550 1551 Support drawing of RLE8-compressed bitmaps on the LCD. 1552 1553 CONFIG_I2C_EDID 1554 1555 Enables an 'i2c edid' command which can read EDID 1556 information over I2C from an attached LCD display. 1557 1558- Splash Screen Support: CONFIG_SPLASH_SCREEN 1559 1560 If this option is set, the environment is checked for 1561 a variable "splashimage". If found, the usual display 1562 of logo, copyright and system information on the LCD 1563 is suppressed and the BMP image at the address 1564 specified in "splashimage" is loaded instead. The 1565 console is redirected to the "nulldev", too. This 1566 allows for a "silent" boot where a splash screen is 1567 loaded very quickly after power-on. 1568 1569 CONFIG_SPLASHIMAGE_GUARD 1570 1571 If this option is set, then U-Boot will prevent the environment 1572 variable "splashimage" from being set to a problematic address 1573 (see doc/README.displaying-bmps). 1574 This option is useful for targets where, due to alignment 1575 restrictions, an improperly aligned BMP image will cause a data 1576 abort. If you think you will not have problems with unaligned 1577 accesses (for example because your toolchain prevents them) 1578 there is no need to set this option. 1579 1580 CONFIG_SPLASH_SCREEN_ALIGN 1581 1582 If this option is set the splash image can be freely positioned 1583 on the screen. Environment variable "splashpos" specifies the 1584 position as "x,y". If a positive number is given it is used as 1585 number of pixel from left/top. If a negative number is given it 1586 is used as number of pixel from right/bottom. You can also 1587 specify 'm' for centering the image. 1588 1589 Example: 1590 setenv splashpos m,m 1591 => image at center of screen 1592 1593 setenv splashpos 30,20 1594 => image at x = 30 and y = 20 1595 1596 setenv splashpos -10,m 1597 => vertically centered image 1598 at x = dspWidth - bmpWidth - 9 1599 1600- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1601 1602 If this option is set, additionally to standard BMP 1603 images, gzipped BMP images can be displayed via the 1604 splashscreen support or the bmp command. 1605 1606- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1607 1608 If this option is set, 8-bit RLE compressed BMP images 1609 can be displayed via the splashscreen support or the 1610 bmp command. 1611 1612- Compression support: 1613 CONFIG_GZIP 1614 1615 Enabled by default to support gzip compressed images. 1616 1617 CONFIG_BZIP2 1618 1619 If this option is set, support for bzip2 compressed 1620 images is included. If not, only uncompressed and gzip 1621 compressed images are supported. 1622 1623 NOTE: the bzip2 algorithm requires a lot of RAM, so 1624 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1625 be at least 4MB. 1626 1627 CONFIG_LZO 1628 1629 If this option is set, support for LZO compressed images 1630 is included. 1631 1632- MII/PHY support: 1633 CONFIG_PHY_ADDR 1634 1635 The address of PHY on MII bus. 1636 1637 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1638 1639 The clock frequency of the MII bus 1640 1641 CONFIG_PHY_GIGE 1642 1643 If this option is set, support for speed/duplex 1644 detection of gigabit PHY is included. 1645 1646 CONFIG_PHY_RESET_DELAY 1647 1648 Some PHY like Intel LXT971A need extra delay after 1649 reset before any MII register access is possible. 1650 For such PHY, set this option to the usec delay 1651 required. (minimum 300usec for LXT971A) 1652 1653 CONFIG_PHY_CMD_DELAY (ppc4xx) 1654 1655 Some PHY like Intel LXT971A need extra delay after 1656 command issued before MII status register can be read 1657 1658- IP address: 1659 CONFIG_IPADDR 1660 1661 Define a default value for the IP address to use for 1662 the default Ethernet interface, in case this is not 1663 determined through e.g. bootp. 1664 (Environment variable "ipaddr") 1665 1666- Server IP address: 1667 CONFIG_SERVERIP 1668 1669 Defines a default value for the IP address of a TFTP 1670 server to contact when using the "tftboot" command. 1671 (Environment variable "serverip") 1672 1673 CONFIG_KEEP_SERVERADDR 1674 1675 Keeps the server's MAC address, in the env 'serveraddr' 1676 for passing to bootargs (like Linux's netconsole option) 1677 1678- Gateway IP address: 1679 CONFIG_GATEWAYIP 1680 1681 Defines a default value for the IP address of the 1682 default router where packets to other networks are 1683 sent to. 1684 (Environment variable "gatewayip") 1685 1686- Subnet mask: 1687 CONFIG_NETMASK 1688 1689 Defines a default value for the subnet mask (or 1690 routing prefix) which is used to determine if an IP 1691 address belongs to the local subnet or needs to be 1692 forwarded through a router. 1693 (Environment variable "netmask") 1694 1695- Multicast TFTP Mode: 1696 CONFIG_MCAST_TFTP 1697 1698 Defines whether you want to support multicast TFTP as per 1699 rfc-2090; for example to work with atftp. Lets lots of targets 1700 tftp down the same boot image concurrently. Note: the Ethernet 1701 driver in use must provide a function: mcast() to join/leave a 1702 multicast group. 1703 1704- BOOTP Recovery Mode: 1705 CONFIG_BOOTP_RANDOM_DELAY 1706 1707 If you have many targets in a network that try to 1708 boot using BOOTP, you may want to avoid that all 1709 systems send out BOOTP requests at precisely the same 1710 moment (which would happen for instance at recovery 1711 from a power failure, when all systems will try to 1712 boot, thus flooding the BOOTP server. Defining 1713 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1714 inserted before sending out BOOTP requests. The 1715 following delays are inserted then: 1716 1717 1st BOOTP request: delay 0 ... 1 sec 1718 2nd BOOTP request: delay 0 ... 2 sec 1719 3rd BOOTP request: delay 0 ... 4 sec 1720 4th and following 1721 BOOTP requests: delay 0 ... 8 sec 1722 1723 CONFIG_BOOTP_ID_CACHE_SIZE 1724 1725 BOOTP packets are uniquely identified using a 32-bit ID. The 1726 server will copy the ID from client requests to responses and 1727 U-Boot will use this to determine if it is the destination of 1728 an incoming response. Some servers will check that addresses 1729 aren't in use before handing them out (usually using an ARP 1730 ping) and therefore take up to a few hundred milliseconds to 1731 respond. Network congestion may also influence the time it 1732 takes for a response to make it back to the client. If that 1733 time is too long, U-Boot will retransmit requests. In order 1734 to allow earlier responses to still be accepted after these 1735 retransmissions, U-Boot's BOOTP client keeps a small cache of 1736 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1737 cache. The default is to keep IDs for up to four outstanding 1738 requests. Increasing this will allow U-Boot to accept offers 1739 from a BOOTP client in networks with unusually high latency. 1740 1741- DHCP Advanced Options: 1742 You can fine tune the DHCP functionality by defining 1743 CONFIG_BOOTP_* symbols: 1744 1745 CONFIG_BOOTP_SUBNETMASK 1746 CONFIG_BOOTP_GATEWAY 1747 CONFIG_BOOTP_HOSTNAME 1748 CONFIG_BOOTP_NISDOMAIN 1749 CONFIG_BOOTP_BOOTPATH 1750 CONFIG_BOOTP_BOOTFILESIZE 1751 CONFIG_BOOTP_DNS 1752 CONFIG_BOOTP_DNS2 1753 CONFIG_BOOTP_SEND_HOSTNAME 1754 CONFIG_BOOTP_NTPSERVER 1755 CONFIG_BOOTP_TIMEOFFSET 1756 CONFIG_BOOTP_VENDOREX 1757 CONFIG_BOOTP_MAY_FAIL 1758 1759 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1760 environment variable, not the BOOTP server. 1761 1762 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1763 after the configured retry count, the call will fail 1764 instead of starting over. This can be used to fail over 1765 to Link-local IP address configuration if the DHCP server 1766 is not available. 1767 1768 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1769 serverip from a DHCP server, it is possible that more 1770 than one DNS serverip is offered to the client. 1771 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1772 serverip will be stored in the additional environment 1773 variable "dnsip2". The first DNS serverip is always 1774 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1775 is defined. 1776 1777 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1778 to do a dynamic update of a DNS server. To do this, they 1779 need the hostname of the DHCP requester. 1780 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1781 of the "hostname" environment variable is passed as 1782 option 12 to the DHCP server. 1783 1784 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1785 1786 A 32bit value in microseconds for a delay between 1787 receiving a "DHCP Offer" and sending the "DHCP Request". 1788 This fixes a problem with certain DHCP servers that don't 1789 respond 100% of the time to a "DHCP request". E.g. On an 1790 AT91RM9200 processor running at 180MHz, this delay needed 1791 to be *at least* 15,000 usec before a Windows Server 2003 1792 DHCP server would reply 100% of the time. I recommend at 1793 least 50,000 usec to be safe. The alternative is to hope 1794 that one of the retries will be successful but note that 1795 the DHCP timeout and retry process takes a longer than 1796 this delay. 1797 1798 - Link-local IP address negotiation: 1799 Negotiate with other link-local clients on the local network 1800 for an address that doesn't require explicit configuration. 1801 This is especially useful if a DHCP server cannot be guaranteed 1802 to exist in all environments that the device must operate. 1803 1804 See doc/README.link-local for more information. 1805 1806 - CDP Options: 1807 CONFIG_CDP_DEVICE_ID 1808 1809 The device id used in CDP trigger frames. 1810 1811 CONFIG_CDP_DEVICE_ID_PREFIX 1812 1813 A two character string which is prefixed to the MAC address 1814 of the device. 1815 1816 CONFIG_CDP_PORT_ID 1817 1818 A printf format string which contains the ascii name of 1819 the port. Normally is set to "eth%d" which sets 1820 eth0 for the first Ethernet, eth1 for the second etc. 1821 1822 CONFIG_CDP_CAPABILITIES 1823 1824 A 32bit integer which indicates the device capabilities; 1825 0x00000010 for a normal host which does not forwards. 1826 1827 CONFIG_CDP_VERSION 1828 1829 An ascii string containing the version of the software. 1830 1831 CONFIG_CDP_PLATFORM 1832 1833 An ascii string containing the name of the platform. 1834 1835 CONFIG_CDP_TRIGGER 1836 1837 A 32bit integer sent on the trigger. 1838 1839 CONFIG_CDP_POWER_CONSUMPTION 1840 1841 A 16bit integer containing the power consumption of the 1842 device in .1 of milliwatts. 1843 1844 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1845 1846 A byte containing the id of the VLAN. 1847 1848- Status LED: CONFIG_LED_STATUS 1849 1850 Several configurations allow to display the current 1851 status using a LED. For instance, the LED will blink 1852 fast while running U-Boot code, stop blinking as 1853 soon as a reply to a BOOTP request was received, and 1854 start blinking slow once the Linux kernel is running 1855 (supported by a status LED driver in the Linux 1856 kernel). Defining CONFIG_LED_STATUS enables this 1857 feature in U-Boot. 1858 1859 Additional options: 1860 1861 CONFIG_LED_STATUS_GPIO 1862 The status LED can be connected to a GPIO pin. 1863 In such cases, the gpio_led driver can be used as a 1864 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1865 to include the gpio_led driver in the U-Boot binary. 1866 1867 CONFIG_GPIO_LED_INVERTED_TABLE 1868 Some GPIO connected LEDs may have inverted polarity in which 1869 case the GPIO high value corresponds to LED off state and 1870 GPIO low value corresponds to LED on state. 1871 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1872 with a list of GPIO LEDs that have inverted polarity. 1873 1874- I2C Support: CONFIG_SYS_I2C 1875 1876 This enable the NEW i2c subsystem, and will allow you to use 1877 i2c commands at the u-boot command line (as long as you set 1878 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1879 based realtime clock chips or other i2c devices. See 1880 common/cmd_i2c.c for a description of the command line 1881 interface. 1882 1883 ported i2c driver to the new framework: 1884 - drivers/i2c/soft_i2c.c: 1885 - activate first bus with CONFIG_SYS_I2C_SOFT define 1886 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1887 for defining speed and slave address 1888 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1889 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1890 for defining speed and slave address 1891 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1892 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1893 for defining speed and slave address 1894 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1895 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1896 for defining speed and slave address 1897 1898 - drivers/i2c/fsl_i2c.c: 1899 - activate i2c driver with CONFIG_SYS_I2C_FSL 1900 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1901 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1902 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1903 bus. 1904 - If your board supports a second fsl i2c bus, define 1905 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1906 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1907 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1908 second bus. 1909 1910 - drivers/i2c/tegra_i2c.c: 1911 - activate this driver with CONFIG_SYS_I2C_TEGRA 1912 - This driver adds 4 i2c buses with a fix speed from 1913 100000 and the slave addr 0! 1914 1915 - drivers/i2c/ppc4xx_i2c.c 1916 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1917 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1918 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1919 1920 - drivers/i2c/i2c_mxc.c 1921 - activate this driver with CONFIG_SYS_I2C_MXC 1922 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1923 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1924 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1925 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1926 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1927 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1928 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1929 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1930 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1931 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1932 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1933 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1934 If those defines are not set, default value is 100000 1935 for speed, and 0 for slave. 1936 1937 - drivers/i2c/rcar_i2c.c: 1938 - activate this driver with CONFIG_SYS_I2C_RCAR 1939 - This driver adds 4 i2c buses 1940 1941 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1942 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1943 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1944 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1945 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1946 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1947 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1948 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1949 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1950 1951 - drivers/i2c/sh_i2c.c: 1952 - activate this driver with CONFIG_SYS_I2C_SH 1953 - This driver adds from 2 to 5 i2c buses 1954 1955 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1956 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1957 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1958 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1959 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1960 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1961 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1962 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1963 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1964 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1965 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1966 1967 - drivers/i2c/omap24xx_i2c.c 1968 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1969 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1970 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1971 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1972 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1973 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1974 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1975 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1976 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1977 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1978 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1979 1980 - drivers/i2c/zynq_i2c.c 1981 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1982 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1983 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1984 1985 - drivers/i2c/s3c24x0_i2c.c: 1986 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1987 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1988 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1989 with a fix speed from 100000 and the slave addr 0! 1990 1991 - drivers/i2c/ihs_i2c.c 1992 - activate this driver with CONFIG_SYS_I2C_IHS 1993 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1994 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1995 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1996 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1997 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1998 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1999 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 2000 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 2001 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 2002 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 2003 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 2004 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 2005 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 2006 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 2007 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 2008 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 2009 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2010 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2011 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2012 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2013 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2014 2015 additional defines: 2016 2017 CONFIG_SYS_NUM_I2C_BUSES 2018 Hold the number of i2c buses you want to use. 2019 2020 CONFIG_SYS_I2C_DIRECT_BUS 2021 define this, if you don't use i2c muxes on your hardware. 2022 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2023 omit this define. 2024 2025 CONFIG_SYS_I2C_MAX_HOPS 2026 define how many muxes are maximal consecutively connected 2027 on one i2c bus. If you not use i2c muxes, omit this 2028 define. 2029 2030 CONFIG_SYS_I2C_BUSES 2031 hold a list of buses you want to use, only used if 2032 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2033 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2034 CONFIG_SYS_NUM_I2C_BUSES = 9: 2035 2036 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2037 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2038 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2039 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2040 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2041 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2042 {1, {I2C_NULL_HOP}}, \ 2043 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2044 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2045 } 2046 2047 which defines 2048 bus 0 on adapter 0 without a mux 2049 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2050 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2051 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2052 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2053 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2054 bus 6 on adapter 1 without a mux 2055 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2056 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2057 2058 If you do not have i2c muxes on your board, omit this define. 2059 2060- Legacy I2C Support: 2061 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2062 then the following macros need to be defined (examples are 2063 from include/configs/lwmon.h): 2064 2065 I2C_INIT 2066 2067 (Optional). Any commands necessary to enable the I2C 2068 controller or configure ports. 2069 2070 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2071 2072 I2C_ACTIVE 2073 2074 The code necessary to make the I2C data line active 2075 (driven). If the data line is open collector, this 2076 define can be null. 2077 2078 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2079 2080 I2C_TRISTATE 2081 2082 The code necessary to make the I2C data line tri-stated 2083 (inactive). If the data line is open collector, this 2084 define can be null. 2085 2086 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2087 2088 I2C_READ 2089 2090 Code that returns true if the I2C data line is high, 2091 false if it is low. 2092 2093 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2094 2095 I2C_SDA(bit) 2096 2097 If <bit> is true, sets the I2C data line high. If it 2098 is false, it clears it (low). 2099 2100 eg: #define I2C_SDA(bit) \ 2101 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2102 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2103 2104 I2C_SCL(bit) 2105 2106 If <bit> is true, sets the I2C clock line high. If it 2107 is false, it clears it (low). 2108 2109 eg: #define I2C_SCL(bit) \ 2110 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2111 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2112 2113 I2C_DELAY 2114 2115 This delay is invoked four times per clock cycle so this 2116 controls the rate of data transfer. The data rate thus 2117 is 1 / (I2C_DELAY * 4). Often defined to be something 2118 like: 2119 2120 #define I2C_DELAY udelay(2) 2121 2122 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2123 2124 If your arch supports the generic GPIO framework (asm/gpio.h), 2125 then you may alternatively define the two GPIOs that are to be 2126 used as SCL / SDA. Any of the previous I2C_xxx macros will 2127 have GPIO-based defaults assigned to them as appropriate. 2128 2129 You should define these to the GPIO value as given directly to 2130 the generic GPIO functions. 2131 2132 CONFIG_SYS_I2C_INIT_BOARD 2133 2134 When a board is reset during an i2c bus transfer 2135 chips might think that the current transfer is still 2136 in progress. On some boards it is possible to access 2137 the i2c SCLK line directly, either by using the 2138 processor pin as a GPIO or by having a second pin 2139 connected to the bus. If this option is defined a 2140 custom i2c_init_board() routine in boards/xxx/board.c 2141 is run early in the boot sequence. 2142 2143 CONFIG_I2C_MULTI_BUS 2144 2145 This option allows the use of multiple I2C buses, each of which 2146 must have a controller. At any point in time, only one bus is 2147 active. To switch to a different bus, use the 'i2c dev' command. 2148 Note that bus numbering is zero-based. 2149 2150 CONFIG_SYS_I2C_NOPROBES 2151 2152 This option specifies a list of I2C devices that will be skipped 2153 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2154 is set, specify a list of bus-device pairs. Otherwise, specify 2155 a 1D array of device addresses 2156 2157 e.g. 2158 #undef CONFIG_I2C_MULTI_BUS 2159 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2160 2161 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2162 2163 #define CONFIG_I2C_MULTI_BUS 2164 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2165 2166 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2167 2168 CONFIG_SYS_SPD_BUS_NUM 2169 2170 If defined, then this indicates the I2C bus number for DDR SPD. 2171 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2172 2173 CONFIG_SYS_RTC_BUS_NUM 2174 2175 If defined, then this indicates the I2C bus number for the RTC. 2176 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2177 2178 CONFIG_SOFT_I2C_READ_REPEATED_START 2179 2180 defining this will force the i2c_read() function in 2181 the soft_i2c driver to perform an I2C repeated start 2182 between writing the address pointer and reading the 2183 data. If this define is omitted the default behaviour 2184 of doing a stop-start sequence will be used. Most I2C 2185 devices can use either method, but some require one or 2186 the other. 2187 2188- SPI Support: CONFIG_SPI 2189 2190 Enables SPI driver (so far only tested with 2191 SPI EEPROM, also an instance works with Crystal A/D and 2192 D/As on the SACSng board) 2193 2194 CONFIG_SH_SPI 2195 2196 Enables the driver for SPI controller on SuperH. Currently 2197 only SH7757 is supported. 2198 2199 CONFIG_SOFT_SPI 2200 2201 Enables a software (bit-bang) SPI driver rather than 2202 using hardware support. This is a general purpose 2203 driver that only requires three general I/O port pins 2204 (two outputs, one input) to function. If this is 2205 defined, the board configuration must define several 2206 SPI configuration items (port pins to use, etc). For 2207 an example, see include/configs/sacsng.h. 2208 2209 CONFIG_HARD_SPI 2210 2211 Enables a hardware SPI driver for general-purpose reads 2212 and writes. As with CONFIG_SOFT_SPI, the board configuration 2213 must define a list of chip-select function pointers. 2214 Currently supported on some MPC8xxx processors. For an 2215 example, see include/configs/mpc8349emds.h. 2216 2217 CONFIG_MXC_SPI 2218 2219 Enables the driver for the SPI controllers on i.MX and MXC 2220 SoCs. Currently i.MX31/35/51 are supported. 2221 2222 CONFIG_SYS_SPI_MXC_WAIT 2223 Timeout for waiting until spi transfer completed. 2224 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2225 2226- FPGA Support: CONFIG_FPGA 2227 2228 Enables FPGA subsystem. 2229 2230 CONFIG_FPGA_<vendor> 2231 2232 Enables support for specific chip vendors. 2233 (ALTERA, XILINX) 2234 2235 CONFIG_FPGA_<family> 2236 2237 Enables support for FPGA family. 2238 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2239 2240 CONFIG_FPGA_COUNT 2241 2242 Specify the number of FPGA devices to support. 2243 2244 CONFIG_SYS_FPGA_PROG_FEEDBACK 2245 2246 Enable printing of hash marks during FPGA configuration. 2247 2248 CONFIG_SYS_FPGA_CHECK_BUSY 2249 2250 Enable checks on FPGA configuration interface busy 2251 status by the configuration function. This option 2252 will require a board or device specific function to 2253 be written. 2254 2255 CONFIG_FPGA_DELAY 2256 2257 If defined, a function that provides delays in the FPGA 2258 configuration driver. 2259 2260 CONFIG_SYS_FPGA_CHECK_CTRLC 2261 Allow Control-C to interrupt FPGA configuration 2262 2263 CONFIG_SYS_FPGA_CHECK_ERROR 2264 2265 Check for configuration errors during FPGA bitfile 2266 loading. For example, abort during Virtex II 2267 configuration if the INIT_B line goes low (which 2268 indicated a CRC error). 2269 2270 CONFIG_SYS_FPGA_WAIT_INIT 2271 2272 Maximum time to wait for the INIT_B line to de-assert 2273 after PROB_B has been de-asserted during a Virtex II 2274 FPGA configuration sequence. The default time is 500 2275 ms. 2276 2277 CONFIG_SYS_FPGA_WAIT_BUSY 2278 2279 Maximum time to wait for BUSY to de-assert during 2280 Virtex II FPGA configuration. The default is 5 ms. 2281 2282 CONFIG_SYS_FPGA_WAIT_CONFIG 2283 2284 Time to wait after FPGA configuration. The default is 2285 200 ms. 2286 2287- Configuration Management: 2288 CONFIG_BUILD_TARGET 2289 2290 Some SoCs need special image types (e.g. U-Boot binary 2291 with a special header) as build targets. By defining 2292 CONFIG_BUILD_TARGET in the SoC / board header, this 2293 special image will be automatically built upon calling 2294 make / buildman. 2295 2296 CONFIG_IDENT_STRING 2297 2298 If defined, this string will be added to the U-Boot 2299 version information (U_BOOT_VERSION) 2300 2301- Vendor Parameter Protection: 2302 2303 U-Boot considers the values of the environment 2304 variables "serial#" (Board Serial Number) and 2305 "ethaddr" (Ethernet Address) to be parameters that 2306 are set once by the board vendor / manufacturer, and 2307 protects these variables from casual modification by 2308 the user. Once set, these variables are read-only, 2309 and write or delete attempts are rejected. You can 2310 change this behaviour: 2311 2312 If CONFIG_ENV_OVERWRITE is #defined in your config 2313 file, the write protection for vendor parameters is 2314 completely disabled. Anybody can change or delete 2315 these parameters. 2316 2317 Alternatively, if you define _both_ an ethaddr in the 2318 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2319 Ethernet address is installed in the environment, 2320 which can be changed exactly ONCE by the user. [The 2321 serial# is unaffected by this, i. e. it remains 2322 read-only.] 2323 2324 The same can be accomplished in a more flexible way 2325 for any variable by configuring the type of access 2326 to allow for those variables in the ".flags" variable 2327 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2328 2329- Protected RAM: 2330 CONFIG_PRAM 2331 2332 Define this variable to enable the reservation of 2333 "protected RAM", i. e. RAM which is not overwritten 2334 by U-Boot. Define CONFIG_PRAM to hold the number of 2335 kB you want to reserve for pRAM. You can overwrite 2336 this default value by defining an environment 2337 variable "pram" to the number of kB you want to 2338 reserve. Note that the board info structure will 2339 still show the full amount of RAM. If pRAM is 2340 reserved, a new environment variable "mem" will 2341 automatically be defined to hold the amount of 2342 remaining RAM in a form that can be passed as boot 2343 argument to Linux, for instance like that: 2344 2345 setenv bootargs ... mem=\${mem} 2346 saveenv 2347 2348 This way you can tell Linux not to use this memory, 2349 either, which results in a memory region that will 2350 not be affected by reboots. 2351 2352 *WARNING* If your board configuration uses automatic 2353 detection of the RAM size, you must make sure that 2354 this memory test is non-destructive. So far, the 2355 following board configurations are known to be 2356 "pRAM-clean": 2357 2358 IVMS8, IVML24, SPD8xx, 2359 HERMES, IP860, RPXlite, LWMON, 2360 FLAGADM 2361 2362- Access to physical memory region (> 4GB) 2363 Some basic support is provided for operations on memory not 2364 normally accessible to U-Boot - e.g. some architectures 2365 support access to more than 4GB of memory on 32-bit 2366 machines using physical address extension or similar. 2367 Define CONFIG_PHYSMEM to access this basic support, which 2368 currently only supports clearing the memory. 2369 2370- Error Recovery: 2371 CONFIG_PANIC_HANG 2372 2373 Define this variable to stop the system in case of a 2374 fatal error, so that you have to reset it manually. 2375 This is probably NOT a good idea for an embedded 2376 system where you want the system to reboot 2377 automatically as fast as possible, but it may be 2378 useful during development since you can try to debug 2379 the conditions that lead to the situation. 2380 2381 CONFIG_NET_RETRY_COUNT 2382 2383 This variable defines the number of retries for 2384 network operations like ARP, RARP, TFTP, or BOOTP 2385 before giving up the operation. If not defined, a 2386 default value of 5 is used. 2387 2388 CONFIG_ARP_TIMEOUT 2389 2390 Timeout waiting for an ARP reply in milliseconds. 2391 2392 CONFIG_NFS_TIMEOUT 2393 2394 Timeout in milliseconds used in NFS protocol. 2395 If you encounter "ERROR: Cannot umount" in nfs command, 2396 try longer timeout such as 2397 #define CONFIG_NFS_TIMEOUT 10000UL 2398 2399- Command Interpreter: 2400 CONFIG_AUTO_COMPLETE 2401 2402 Enable auto completion of commands using TAB. 2403 2404 CONFIG_SYS_PROMPT_HUSH_PS2 2405 2406 This defines the secondary prompt string, which is 2407 printed when the command interpreter needs more input 2408 to complete a command. Usually "> ". 2409 2410 Note: 2411 2412 In the current implementation, the local variables 2413 space and global environment variables space are 2414 separated. Local variables are those you define by 2415 simply typing `name=value'. To access a local 2416 variable later on, you have write `$name' or 2417 `${name}'; to execute the contents of a variable 2418 directly type `$name' at the command prompt. 2419 2420 Global environment variables are those you use 2421 setenv/printenv to work with. To run a command stored 2422 in such a variable, you need to use the run command, 2423 and you must not use the '$' sign to access them. 2424 2425 To store commands and special characters in a 2426 variable, please use double quotation marks 2427 surrounding the whole text of the variable, instead 2428 of the backslashes before semicolons and special 2429 symbols. 2430 2431- Command Line Editing and History: 2432 CONFIG_CMDLINE_EDITING 2433 2434 Enable editing and History functions for interactive 2435 command line input operations 2436 2437- Command Line PS1/PS2 support: 2438 CONFIG_CMDLINE_PS_SUPPORT 2439 2440 Enable support for changing the command prompt string 2441 at run-time. Only static string is supported so far. 2442 The string is obtained from environment variables PS1 2443 and PS2. 2444 2445- Default Environment: 2446 CONFIG_EXTRA_ENV_SETTINGS 2447 2448 Define this to contain any number of null terminated 2449 strings (variable = value pairs) that will be part of 2450 the default environment compiled into the boot image. 2451 2452 For example, place something like this in your 2453 board's config file: 2454 2455 #define CONFIG_EXTRA_ENV_SETTINGS \ 2456 "myvar1=value1\0" \ 2457 "myvar2=value2\0" 2458 2459 Warning: This method is based on knowledge about the 2460 internal format how the environment is stored by the 2461 U-Boot code. This is NOT an official, exported 2462 interface! Although it is unlikely that this format 2463 will change soon, there is no guarantee either. 2464 You better know what you are doing here. 2465 2466 Note: overly (ab)use of the default environment is 2467 discouraged. Make sure to check other ways to preset 2468 the environment like the "source" command or the 2469 boot command first. 2470 2471 CONFIG_ENV_VARS_UBOOT_CONFIG 2472 2473 Define this in order to add variables describing the 2474 U-Boot build configuration to the default environment. 2475 These will be named arch, cpu, board, vendor, and soc. 2476 2477 Enabling this option will cause the following to be defined: 2478 2479 - CONFIG_SYS_ARCH 2480 - CONFIG_SYS_CPU 2481 - CONFIG_SYS_BOARD 2482 - CONFIG_SYS_VENDOR 2483 - CONFIG_SYS_SOC 2484 2485 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2486 2487 Define this in order to add variables describing certain 2488 run-time determined information about the hardware to the 2489 environment. These will be named board_name, board_rev. 2490 2491 CONFIG_DELAY_ENVIRONMENT 2492 2493 Normally the environment is loaded when the board is 2494 initialised so that it is available to U-Boot. This inhibits 2495 that so that the environment is not available until 2496 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2497 this is instead controlled by the value of 2498 /config/load-environment. 2499 2500- DataFlash Support: 2501 CONFIG_HAS_DATAFLASH 2502 2503 Defining this option enables DataFlash features and 2504 allows to read/write in Dataflash via the standard 2505 commands cp, md... 2506 2507- Serial Flash support 2508 CONFIG_CMD_SF 2509 2510 Defining this option enables SPI flash commands 2511 'sf probe/read/write/erase/update'. 2512 2513 Usage requires an initial 'probe' to define the serial 2514 flash parameters, followed by read/write/erase/update 2515 commands. 2516 2517 The following defaults may be provided by the platform 2518 to handle the common case when only a single serial 2519 flash is present on the system. 2520 2521 CONFIG_SF_DEFAULT_BUS Bus identifier 2522 CONFIG_SF_DEFAULT_CS Chip-select 2523 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2524 CONFIG_SF_DEFAULT_SPEED in Hz 2525 2526 CONFIG_CMD_SF_TEST 2527 2528 Define this option to include a destructive SPI flash 2529 test ('sf test'). 2530 2531- SystemACE Support: 2532 CONFIG_SYSTEMACE 2533 2534 Adding this option adds support for Xilinx SystemACE 2535 chips attached via some sort of local bus. The address 2536 of the chip must also be defined in the 2537 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2538 2539 #define CONFIG_SYSTEMACE 2540 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2541 2542 When SystemACE support is added, the "ace" device type 2543 becomes available to the fat commands, i.e. fatls. 2544 2545- TFTP Fixed UDP Port: 2546 CONFIG_TFTP_PORT 2547 2548 If this is defined, the environment variable tftpsrcp 2549 is used to supply the TFTP UDP source port value. 2550 If tftpsrcp isn't defined, the normal pseudo-random port 2551 number generator is used. 2552 2553 Also, the environment variable tftpdstp is used to supply 2554 the TFTP UDP destination port value. If tftpdstp isn't 2555 defined, the normal port 69 is used. 2556 2557 The purpose for tftpsrcp is to allow a TFTP server to 2558 blindly start the TFTP transfer using the pre-configured 2559 target IP address and UDP port. This has the effect of 2560 "punching through" the (Windows XP) firewall, allowing 2561 the remainder of the TFTP transfer to proceed normally. 2562 A better solution is to properly configure the firewall, 2563 but sometimes that is not allowed. 2564 2565- bootcount support: 2566 CONFIG_BOOTCOUNT_LIMIT 2567 2568 This enables the bootcounter support, see: 2569 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2570 2571 CONFIG_AT91SAM9XE 2572 enable special bootcounter support on at91sam9xe based boards. 2573 CONFIG_SOC_DA8XX 2574 enable special bootcounter support on da850 based boards. 2575 CONFIG_BOOTCOUNT_RAM 2576 enable support for the bootcounter in RAM 2577 CONFIG_BOOTCOUNT_I2C 2578 enable support for the bootcounter on an i2c (like RTC) device. 2579 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2580 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2581 the bootcounter. 2582 CONFIG_BOOTCOUNT_ALEN = address len 2583 2584- Show boot progress: 2585 CONFIG_SHOW_BOOT_PROGRESS 2586 2587 Defining this option allows to add some board- 2588 specific code (calling a user-provided function 2589 "show_boot_progress(int)") that enables you to show 2590 the system's boot progress on some display (for 2591 example, some LED's) on your board. At the moment, 2592 the following checkpoints are implemented: 2593 2594 2595Legacy uImage format: 2596 2597 Arg Where When 2598 1 common/cmd_bootm.c before attempting to boot an image 2599 -1 common/cmd_bootm.c Image header has bad magic number 2600 2 common/cmd_bootm.c Image header has correct magic number 2601 -2 common/cmd_bootm.c Image header has bad checksum 2602 3 common/cmd_bootm.c Image header has correct checksum 2603 -3 common/cmd_bootm.c Image data has bad checksum 2604 4 common/cmd_bootm.c Image data has correct checksum 2605 -4 common/cmd_bootm.c Image is for unsupported architecture 2606 5 common/cmd_bootm.c Architecture check OK 2607 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2608 6 common/cmd_bootm.c Image Type check OK 2609 -6 common/cmd_bootm.c gunzip uncompression error 2610 -7 common/cmd_bootm.c Unimplemented compression type 2611 7 common/cmd_bootm.c Uncompression OK 2612 8 common/cmd_bootm.c No uncompress/copy overwrite error 2613 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2614 2615 9 common/image.c Start initial ramdisk verification 2616 -10 common/image.c Ramdisk header has bad magic number 2617 -11 common/image.c Ramdisk header has bad checksum 2618 10 common/image.c Ramdisk header is OK 2619 -12 common/image.c Ramdisk data has bad checksum 2620 11 common/image.c Ramdisk data has correct checksum 2621 12 common/image.c Ramdisk verification complete, start loading 2622 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2623 13 common/image.c Start multifile image verification 2624 14 common/image.c No initial ramdisk, no multifile, continue. 2625 2626 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2627 2628 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2629 -31 post/post.c POST test failed, detected by post_output_backlog() 2630 -32 post/post.c POST test failed, detected by post_run_single() 2631 2632 34 common/cmd_doc.c before loading a Image from a DOC device 2633 -35 common/cmd_doc.c Bad usage of "doc" command 2634 35 common/cmd_doc.c correct usage of "doc" command 2635 -36 common/cmd_doc.c No boot device 2636 36 common/cmd_doc.c correct boot device 2637 -37 common/cmd_doc.c Unknown Chip ID on boot device 2638 37 common/cmd_doc.c correct chip ID found, device available 2639 -38 common/cmd_doc.c Read Error on boot device 2640 38 common/cmd_doc.c reading Image header from DOC device OK 2641 -39 common/cmd_doc.c Image header has bad magic number 2642 39 common/cmd_doc.c Image header has correct magic number 2643 -40 common/cmd_doc.c Error reading Image from DOC device 2644 40 common/cmd_doc.c Image header has correct magic number 2645 41 common/cmd_ide.c before loading a Image from a IDE device 2646 -42 common/cmd_ide.c Bad usage of "ide" command 2647 42 common/cmd_ide.c correct usage of "ide" command 2648 -43 common/cmd_ide.c No boot device 2649 43 common/cmd_ide.c boot device found 2650 -44 common/cmd_ide.c Device not available 2651 44 common/cmd_ide.c Device available 2652 -45 common/cmd_ide.c wrong partition selected 2653 45 common/cmd_ide.c partition selected 2654 -46 common/cmd_ide.c Unknown partition table 2655 46 common/cmd_ide.c valid partition table found 2656 -47 common/cmd_ide.c Invalid partition type 2657 47 common/cmd_ide.c correct partition type 2658 -48 common/cmd_ide.c Error reading Image Header on boot device 2659 48 common/cmd_ide.c reading Image Header from IDE device OK 2660 -49 common/cmd_ide.c Image header has bad magic number 2661 49 common/cmd_ide.c Image header has correct magic number 2662 -50 common/cmd_ide.c Image header has bad checksum 2663 50 common/cmd_ide.c Image header has correct checksum 2664 -51 common/cmd_ide.c Error reading Image from IDE device 2665 51 common/cmd_ide.c reading Image from IDE device OK 2666 52 common/cmd_nand.c before loading a Image from a NAND device 2667 -53 common/cmd_nand.c Bad usage of "nand" command 2668 53 common/cmd_nand.c correct usage of "nand" command 2669 -54 common/cmd_nand.c No boot device 2670 54 common/cmd_nand.c boot device found 2671 -55 common/cmd_nand.c Unknown Chip ID on boot device 2672 55 common/cmd_nand.c correct chip ID found, device available 2673 -56 common/cmd_nand.c Error reading Image Header on boot device 2674 56 common/cmd_nand.c reading Image Header from NAND device OK 2675 -57 common/cmd_nand.c Image header has bad magic number 2676 57 common/cmd_nand.c Image header has correct magic number 2677 -58 common/cmd_nand.c Error reading Image from NAND device 2678 58 common/cmd_nand.c reading Image from NAND device OK 2679 2680 -60 common/env_common.c Environment has a bad CRC, using default 2681 2682 64 net/eth.c starting with Ethernet configuration. 2683 -64 net/eth.c no Ethernet found. 2684 65 net/eth.c Ethernet found. 2685 2686 -80 common/cmd_net.c usage wrong 2687 80 common/cmd_net.c before calling net_loop() 2688 -81 common/cmd_net.c some error in net_loop() occurred 2689 81 common/cmd_net.c net_loop() back without error 2690 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2691 82 common/cmd_net.c trying automatic boot 2692 83 common/cmd_net.c running "source" command 2693 -83 common/cmd_net.c some error in automatic boot or "source" command 2694 84 common/cmd_net.c end without errors 2695 2696FIT uImage format: 2697 2698 Arg Where When 2699 100 common/cmd_bootm.c Kernel FIT Image has correct format 2700 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2701 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2702 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2703 102 common/cmd_bootm.c Kernel unit name specified 2704 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2705 103 common/cmd_bootm.c Found configuration node 2706 104 common/cmd_bootm.c Got kernel subimage node offset 2707 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2708 105 common/cmd_bootm.c Kernel subimage hash verification OK 2709 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2710 106 common/cmd_bootm.c Architecture check OK 2711 -106 common/cmd_bootm.c Kernel subimage has wrong type 2712 107 common/cmd_bootm.c Kernel subimage type OK 2713 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2714 108 common/cmd_bootm.c Got kernel subimage data/size 2715 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2716 -109 common/cmd_bootm.c Can't get kernel subimage type 2717 -110 common/cmd_bootm.c Can't get kernel subimage comp 2718 -111 common/cmd_bootm.c Can't get kernel subimage os 2719 -112 common/cmd_bootm.c Can't get kernel subimage load address 2720 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2721 2722 120 common/image.c Start initial ramdisk verification 2723 -120 common/image.c Ramdisk FIT image has incorrect format 2724 121 common/image.c Ramdisk FIT image has correct format 2725 122 common/image.c No ramdisk subimage unit name, using configuration 2726 -122 common/image.c Can't get configuration for ramdisk subimage 2727 123 common/image.c Ramdisk unit name specified 2728 -124 common/image.c Can't get ramdisk subimage node offset 2729 125 common/image.c Got ramdisk subimage node offset 2730 -125 common/image.c Ramdisk subimage hash verification failed 2731 126 common/image.c Ramdisk subimage hash verification OK 2732 -126 common/image.c Ramdisk subimage for unsupported architecture 2733 127 common/image.c Architecture check OK 2734 -127 common/image.c Can't get ramdisk subimage data/size 2735 128 common/image.c Got ramdisk subimage data/size 2736 129 common/image.c Can't get ramdisk load address 2737 -129 common/image.c Got ramdisk load address 2738 2739 -130 common/cmd_doc.c Incorrect FIT image format 2740 131 common/cmd_doc.c FIT image format OK 2741 2742 -140 common/cmd_ide.c Incorrect FIT image format 2743 141 common/cmd_ide.c FIT image format OK 2744 2745 -150 common/cmd_nand.c Incorrect FIT image format 2746 151 common/cmd_nand.c FIT image format OK 2747 2748- legacy image format: 2749 CONFIG_IMAGE_FORMAT_LEGACY 2750 enables the legacy image format support in U-Boot. 2751 2752 Default: 2753 enabled if CONFIG_FIT_SIGNATURE is not defined. 2754 2755 CONFIG_DISABLE_IMAGE_LEGACY 2756 disable the legacy image format 2757 2758 This define is introduced, as the legacy image format is 2759 enabled per default for backward compatibility. 2760 2761- Standalone program support: 2762 CONFIG_STANDALONE_LOAD_ADDR 2763 2764 This option defines a board specific value for the 2765 address where standalone program gets loaded, thus 2766 overwriting the architecture dependent default 2767 settings. 2768 2769- Frame Buffer Address: 2770 CONFIG_FB_ADDR 2771 2772 Define CONFIG_FB_ADDR if you want to use specific 2773 address for frame buffer. This is typically the case 2774 when using a graphics controller has separate video 2775 memory. U-Boot will then place the frame buffer at 2776 the given address instead of dynamically reserving it 2777 in system RAM by calling lcd_setmem(), which grabs 2778 the memory for the frame buffer depending on the 2779 configured panel size. 2780 2781 Please see board_init_f function. 2782 2783- Automatic software updates via TFTP server 2784 CONFIG_UPDATE_TFTP 2785 CONFIG_UPDATE_TFTP_CNT_MAX 2786 CONFIG_UPDATE_TFTP_MSEC_MAX 2787 2788 These options enable and control the auto-update feature; 2789 for a more detailed description refer to doc/README.update. 2790 2791- MTD Support (mtdparts command, UBI support) 2792 CONFIG_MTD_DEVICE 2793 2794 Adds the MTD device infrastructure from the Linux kernel. 2795 Needed for mtdparts command support. 2796 2797 CONFIG_MTD_PARTITIONS 2798 2799 Adds the MTD partitioning infrastructure from the Linux 2800 kernel. Needed for UBI support. 2801 2802- UBI support 2803 CONFIG_CMD_UBI 2804 2805 Adds commands for interacting with MTD partitions formatted 2806 with the UBI flash translation layer 2807 2808 Requires also defining CONFIG_RBTREE 2809 2810 CONFIG_UBI_SILENCE_MSG 2811 2812 Make the verbose messages from UBI stop printing. This leaves 2813 warnings and errors enabled. 2814 2815 2816 CONFIG_MTD_UBI_WL_THRESHOLD 2817 This parameter defines the maximum difference between the highest 2818 erase counter value and the lowest erase counter value of eraseblocks 2819 of UBI devices. When this threshold is exceeded, UBI starts performing 2820 wear leveling by means of moving data from eraseblock with low erase 2821 counter to eraseblocks with high erase counter. 2822 2823 The default value should be OK for SLC NAND flashes, NOR flashes and 2824 other flashes which have eraseblock life-cycle 100000 or more. 2825 However, in case of MLC NAND flashes which typically have eraseblock 2826 life-cycle less than 10000, the threshold should be lessened (e.g., 2827 to 128 or 256, although it does not have to be power of 2). 2828 2829 default: 4096 2830 2831 CONFIG_MTD_UBI_BEB_LIMIT 2832 This option specifies the maximum bad physical eraseblocks UBI 2833 expects on the MTD device (per 1024 eraseblocks). If the 2834 underlying flash does not admit of bad eraseblocks (e.g. NOR 2835 flash), this value is ignored. 2836 2837 NAND datasheets often specify the minimum and maximum NVM 2838 (Number of Valid Blocks) for the flashes' endurance lifetime. 2839 The maximum expected bad eraseblocks per 1024 eraseblocks 2840 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2841 which gives 20 for most NANDs (MaxNVB is basically the total 2842 count of eraseblocks on the chip). 2843 2844 To put it differently, if this value is 20, UBI will try to 2845 reserve about 1.9% of physical eraseblocks for bad blocks 2846 handling. And that will be 1.9% of eraseblocks on the entire 2847 NAND chip, not just the MTD partition UBI attaches. This means 2848 that if you have, say, a NAND flash chip admits maximum 40 bad 2849 eraseblocks, and it is split on two MTD partitions of the same 2850 size, UBI will reserve 40 eraseblocks when attaching a 2851 partition. 2852 2853 default: 20 2854 2855 CONFIG_MTD_UBI_FASTMAP 2856 Fastmap is a mechanism which allows attaching an UBI device 2857 in nearly constant time. Instead of scanning the whole MTD device it 2858 only has to locate a checkpoint (called fastmap) on the device. 2859 The on-flash fastmap contains all information needed to attach 2860 the device. Using fastmap makes only sense on large devices where 2861 attaching by scanning takes long. UBI will not automatically install 2862 a fastmap on old images, but you can set the UBI parameter 2863 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2864 that fastmap-enabled images are still usable with UBI implementations 2865 without fastmap support. On typical flash devices the whole fastmap 2866 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2867 2868 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2869 Set this parameter to enable fastmap automatically on images 2870 without a fastmap. 2871 default: 0 2872 2873 CONFIG_MTD_UBI_FM_DEBUG 2874 Enable UBI fastmap debug 2875 default: 0 2876 2877- UBIFS support 2878 CONFIG_CMD_UBIFS 2879 2880 Adds commands for interacting with UBI volumes formatted as 2881 UBIFS. UBIFS is read-only in u-boot. 2882 2883 Requires UBI support as well as CONFIG_LZO 2884 2885 CONFIG_UBIFS_SILENCE_MSG 2886 2887 Make the verbose messages from UBIFS stop printing. This leaves 2888 warnings and errors enabled. 2889 2890- SPL framework 2891 CONFIG_SPL 2892 Enable building of SPL globally. 2893 2894 CONFIG_SPL_LDSCRIPT 2895 LDSCRIPT for linking the SPL binary. 2896 2897 CONFIG_SPL_MAX_FOOTPRINT 2898 Maximum size in memory allocated to the SPL, BSS included. 2899 When defined, the linker checks that the actual memory 2900 used by SPL from _start to __bss_end does not exceed it. 2901 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2902 must not be both defined at the same time. 2903 2904 CONFIG_SPL_MAX_SIZE 2905 Maximum size of the SPL image (text, data, rodata, and 2906 linker lists sections), BSS excluded. 2907 When defined, the linker checks that the actual size does 2908 not exceed it. 2909 2910 CONFIG_SPL_TEXT_BASE 2911 TEXT_BASE for linking the SPL binary. 2912 2913 CONFIG_SPL_RELOC_TEXT_BASE 2914 Address to relocate to. If unspecified, this is equal to 2915 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2916 2917 CONFIG_SPL_BSS_START_ADDR 2918 Link address for the BSS within the SPL binary. 2919 2920 CONFIG_SPL_BSS_MAX_SIZE 2921 Maximum size in memory allocated to the SPL BSS. 2922 When defined, the linker checks that the actual memory used 2923 by SPL from __bss_start to __bss_end does not exceed it. 2924 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2925 must not be both defined at the same time. 2926 2927 CONFIG_SPL_STACK 2928 Adress of the start of the stack SPL will use 2929 2930 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2931 When defined, SPL will panic() if the image it has 2932 loaded does not have a signature. 2933 Defining this is useful when code which loads images 2934 in SPL cannot guarantee that absolutely all read errors 2935 will be caught. 2936 An example is the LPC32XX MLC NAND driver, which will 2937 consider that a completely unreadable NAND block is bad, 2938 and thus should be skipped silently. 2939 2940 CONFIG_SPL_RELOC_STACK 2941 Adress of the start of the stack SPL will use after 2942 relocation. If unspecified, this is equal to 2943 CONFIG_SPL_STACK. 2944 2945 CONFIG_SYS_SPL_MALLOC_START 2946 Starting address of the malloc pool used in SPL. 2947 When this option is set the full malloc is used in SPL and 2948 it is set up by spl_init() and before that, the simple malloc() 2949 can be used if CONFIG_SYS_MALLOC_F is defined. 2950 2951 CONFIG_SYS_SPL_MALLOC_SIZE 2952 The size of the malloc pool used in SPL. 2953 2954 CONFIG_SPL_FRAMEWORK 2955 Enable the SPL framework under common/. This framework 2956 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2957 NAND loading of the Linux Kernel. 2958 2959 CONFIG_SPL_OS_BOOT 2960 Enable booting directly to an OS from SPL. 2961 See also: doc/README.falcon 2962 2963 CONFIG_SPL_DISPLAY_PRINT 2964 For ARM, enable an optional function to print more information 2965 about the running system. 2966 2967 CONFIG_SPL_INIT_MINIMAL 2968 Arch init code should be built for a very small image 2969 2970 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2971 Partition on the MMC to load U-Boot from when the MMC is being 2972 used in raw mode 2973 2974 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2975 Sector to load kernel uImage from when MMC is being 2976 used in raw mode (for Falcon mode) 2977 2978 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2979 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2980 Sector and number of sectors to load kernel argument 2981 parameters from when MMC is being used in raw mode 2982 (for falcon mode) 2983 2984 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2985 Partition on the MMC to load U-Boot from when the MMC is being 2986 used in fs mode 2987 2988 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2989 Filename to read to load U-Boot when reading from filesystem 2990 2991 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2992 Filename to read to load kernel uImage when reading 2993 from filesystem (for Falcon mode) 2994 2995 CONFIG_SPL_FS_LOAD_ARGS_NAME 2996 Filename to read to load kernel argument parameters 2997 when reading from filesystem (for Falcon mode) 2998 2999 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 3000 Set this for NAND SPL on PPC mpc83xx targets, so that 3001 start.S waits for the rest of the SPL to load before 3002 continuing (the hardware starts execution after just 3003 loading the first page rather than the full 4K). 3004 3005 CONFIG_SPL_SKIP_RELOCATE 3006 Avoid SPL relocation 3007 3008 CONFIG_SPL_NAND_BASE 3009 Include nand_base.c in the SPL. Requires 3010 CONFIG_SPL_NAND_DRIVERS. 3011 3012 CONFIG_SPL_NAND_DRIVERS 3013 SPL uses normal NAND drivers, not minimal drivers. 3014 3015 CONFIG_SPL_NAND_ECC 3016 Include standard software ECC in the SPL 3017 3018 CONFIG_SPL_NAND_SIMPLE 3019 Support for NAND boot using simple NAND drivers that 3020 expose the cmd_ctrl() interface. 3021 3022 CONFIG_SPL_UBI 3023 Support for a lightweight UBI (fastmap) scanner and 3024 loader 3025 3026 CONFIG_SPL_NAND_RAW_ONLY 3027 Support to boot only raw u-boot.bin images. Use this only 3028 if you need to save space. 3029 3030 CONFIG_SPL_COMMON_INIT_DDR 3031 Set for common ddr init with serial presence detect in 3032 SPL binary. 3033 3034 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3035 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3036 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3037 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3038 CONFIG_SYS_NAND_ECCBYTES 3039 Defines the size and behavior of the NAND that SPL uses 3040 to read U-Boot 3041 3042 CONFIG_SPL_NAND_BOOT 3043 Add support NAND boot 3044 3045 CONFIG_SYS_NAND_U_BOOT_OFFS 3046 Location in NAND to read U-Boot from 3047 3048 CONFIG_SYS_NAND_U_BOOT_DST 3049 Location in memory to load U-Boot to 3050 3051 CONFIG_SYS_NAND_U_BOOT_SIZE 3052 Size of image to load 3053 3054 CONFIG_SYS_NAND_U_BOOT_START 3055 Entry point in loaded image to jump to 3056 3057 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3058 Define this if you need to first read the OOB and then the 3059 data. This is used, for example, on davinci platforms. 3060 3061 CONFIG_SPL_OMAP3_ID_NAND 3062 Support for an OMAP3-specific set of functions to return the 3063 ID and MFR of the first attached NAND chip, if present. 3064 3065 CONFIG_SPL_RAM_DEVICE 3066 Support for running image already present in ram, in SPL binary 3067 3068 CONFIG_SPL_PAD_TO 3069 Image offset to which the SPL should be padded before appending 3070 the SPL payload. By default, this is defined as 3071 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3072 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3073 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3074 3075 CONFIG_SPL_TARGET 3076 Final target image containing SPL and payload. Some SPLs 3077 use an arch-specific makefile fragment instead, for 3078 example if more than one image needs to be produced. 3079 3080 CONFIG_FIT_SPL_PRINT 3081 Printing information about a FIT image adds quite a bit of 3082 code to SPL. So this is normally disabled in SPL. Use this 3083 option to re-enable it. This will affect the output of the 3084 bootm command when booting a FIT image. 3085 3086- TPL framework 3087 CONFIG_TPL 3088 Enable building of TPL globally. 3089 3090 CONFIG_TPL_PAD_TO 3091 Image offset to which the TPL should be padded before appending 3092 the TPL payload. By default, this is defined as 3093 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3094 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3095 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3096 3097- Interrupt support (PPC): 3098 3099 There are common interrupt_init() and timer_interrupt() 3100 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3101 for CPU specific initialization. interrupt_init_cpu() 3102 should set decrementer_count to appropriate value. If 3103 CPU resets decrementer automatically after interrupt 3104 (ppc4xx) it should set decrementer_count to zero. 3105 timer_interrupt() calls timer_interrupt_cpu() for CPU 3106 specific handling. If board has watchdog / status_led 3107 / other_activity_monitor it works automatically from 3108 general timer_interrupt(). 3109 3110 3111Board initialization settings: 3112------------------------------ 3113 3114During Initialization u-boot calls a number of board specific functions 3115to allow the preparation of board specific prerequisites, e.g. pin setup 3116before drivers are initialized. To enable these callbacks the 3117following configuration macros have to be defined. Currently this is 3118architecture specific, so please check arch/your_architecture/lib/board.c 3119typically in board_init_f() and board_init_r(). 3120 3121- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3122- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3123- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3124- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3125 3126Configuration Settings: 3127----------------------- 3128 3129- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3130 Optionally it can be defined to support 64-bit memory commands. 3131 3132- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3133 undefine this when you're short of memory. 3134 3135- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3136 width of the commands listed in the 'help' command output. 3137 3138- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3139 prompt for user input. 3140 3141- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3142 3143- CONFIG_SYS_PBSIZE: Buffer size for Console output 3144 3145- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3146 3147- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3148 the application (usually a Linux kernel) when it is 3149 booted 3150 3151- CONFIG_SYS_BAUDRATE_TABLE: 3152 List of legal baudrate settings for this board. 3153 3154- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3155 Begin and End addresses of the area used by the 3156 simple memory test. 3157 3158- CONFIG_SYS_ALT_MEMTEST: 3159 Enable an alternate, more extensive memory test. 3160 3161- CONFIG_SYS_MEMTEST_SCRATCH: 3162 Scratch address used by the alternate memory test 3163 You only need to set this if address zero isn't writeable 3164 3165- CONFIG_SYS_MEM_RESERVE_SECURE 3166 Only implemented for ARMv8 for now. 3167 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3168 is substracted from total RAM and won't be reported to OS. 3169 This memory can be used as secure memory. A variable 3170 gd->arch.secure_ram is used to track the location. In systems 3171 the RAM base is not zero, or RAM is divided into banks, 3172 this variable needs to be recalcuated to get the address. 3173 3174- CONFIG_SYS_MEM_TOP_HIDE: 3175 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3176 this specified memory area will get subtracted from the top 3177 (end) of RAM and won't get "touched" at all by U-Boot. By 3178 fixing up gd->ram_size the Linux kernel should gets passed 3179 the now "corrected" memory size and won't touch it either. 3180 This should work for arch/ppc and arch/powerpc. Only Linux 3181 board ports in arch/powerpc with bootwrapper support that 3182 recalculate the memory size from the SDRAM controller setup 3183 will have to get fixed in Linux additionally. 3184 3185 This option can be used as a workaround for the 440EPx/GRx 3186 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3187 be touched. 3188 3189 WARNING: Please make sure that this value is a multiple of 3190 the Linux page size (normally 4k). If this is not the case, 3191 then the end address of the Linux memory will be located at a 3192 non page size aligned address and this could cause major 3193 problems. 3194 3195- CONFIG_SYS_LOADS_BAUD_CHANGE: 3196 Enable temporary baudrate change while serial download 3197 3198- CONFIG_SYS_SDRAM_BASE: 3199 Physical start address of SDRAM. _Must_ be 0 here. 3200 3201- CONFIG_SYS_FLASH_BASE: 3202 Physical start address of Flash memory. 3203 3204- CONFIG_SYS_MONITOR_BASE: 3205 Physical start address of boot monitor code (set by 3206 make config files to be same as the text base address 3207 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3208 CONFIG_SYS_FLASH_BASE when booting from flash. 3209 3210- CONFIG_SYS_MONITOR_LEN: 3211 Size of memory reserved for monitor code, used to 3212 determine _at_compile_time_ (!) if the environment is 3213 embedded within the U-Boot image, or in a separate 3214 flash sector. 3215 3216- CONFIG_SYS_MALLOC_LEN: 3217 Size of DRAM reserved for malloc() use. 3218 3219- CONFIG_SYS_MALLOC_F_LEN 3220 Size of the malloc() pool for use before relocation. If 3221 this is defined, then a very simple malloc() implementation 3222 will become available before relocation. The address is just 3223 below the global data, and the stack is moved down to make 3224 space. 3225 3226 This feature allocates regions with increasing addresses 3227 within the region. calloc() is supported, but realloc() 3228 is not available. free() is supported but does nothing. 3229 The memory will be freed (or in fact just forgotten) when 3230 U-Boot relocates itself. 3231 3232- CONFIG_SYS_MALLOC_SIMPLE 3233 Provides a simple and small malloc() and calloc() for those 3234 boards which do not use the full malloc in SPL (which is 3235 enabled with CONFIG_SYS_SPL_MALLOC_START). 3236 3237- CONFIG_SYS_NONCACHED_MEMORY: 3238 Size of non-cached memory area. This area of memory will be 3239 typically located right below the malloc() area and mapped 3240 uncached in the MMU. This is useful for drivers that would 3241 otherwise require a lot of explicit cache maintenance. For 3242 some drivers it's also impossible to properly maintain the 3243 cache. For example if the regions that need to be flushed 3244 are not a multiple of the cache-line size, *and* padding 3245 cannot be allocated between the regions to align them (i.e. 3246 if the HW requires a contiguous array of regions, and the 3247 size of each region is not cache-aligned), then a flush of 3248 one region may result in overwriting data that hardware has 3249 written to another region in the same cache-line. This can 3250 happen for example in network drivers where descriptors for 3251 buffers are typically smaller than the CPU cache-line (e.g. 3252 16 bytes vs. 32 or 64 bytes). 3253 3254 Non-cached memory is only supported on 32-bit ARM at present. 3255 3256- CONFIG_SYS_BOOTM_LEN: 3257 Normally compressed uImages are limited to an 3258 uncompressed size of 8 MBytes. If this is not enough, 3259 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3260 to adjust this setting to your needs. 3261 3262- CONFIG_SYS_BOOTMAPSZ: 3263 Maximum size of memory mapped by the startup code of 3264 the Linux kernel; all data that must be processed by 3265 the Linux kernel (bd_info, boot arguments, FDT blob if 3266 used) must be put below this limit, unless "bootm_low" 3267 environment variable is defined and non-zero. In such case 3268 all data for the Linux kernel must be between "bootm_low" 3269 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3270 variable "bootm_mapsize" will override the value of 3271 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3272 then the value in "bootm_size" will be used instead. 3273 3274- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3275 Enable initrd_high functionality. If defined then the 3276 initrd_high feature is enabled and the bootm ramdisk subcommand 3277 is enabled. 3278 3279- CONFIG_SYS_BOOT_GET_CMDLINE: 3280 Enables allocating and saving kernel cmdline in space between 3281 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3282 3283- CONFIG_SYS_BOOT_GET_KBD: 3284 Enables allocating and saving a kernel copy of the bd_info in 3285 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3286 3287- CONFIG_SYS_MAX_FLASH_BANKS: 3288 Max number of Flash memory banks 3289 3290- CONFIG_SYS_MAX_FLASH_SECT: 3291 Max number of sectors on a Flash chip 3292 3293- CONFIG_SYS_FLASH_ERASE_TOUT: 3294 Timeout for Flash erase operations (in ms) 3295 3296- CONFIG_SYS_FLASH_WRITE_TOUT: 3297 Timeout for Flash write operations (in ms) 3298 3299- CONFIG_SYS_FLASH_LOCK_TOUT 3300 Timeout for Flash set sector lock bit operation (in ms) 3301 3302- CONFIG_SYS_FLASH_UNLOCK_TOUT 3303 Timeout for Flash clear lock bits operation (in ms) 3304 3305- CONFIG_SYS_FLASH_PROTECTION 3306 If defined, hardware flash sectors protection is used 3307 instead of U-Boot software protection. 3308 3309- CONFIG_SYS_DIRECT_FLASH_TFTP: 3310 3311 Enable TFTP transfers directly to flash memory; 3312 without this option such a download has to be 3313 performed in two steps: (1) download to RAM, and (2) 3314 copy from RAM to flash. 3315 3316 The two-step approach is usually more reliable, since 3317 you can check if the download worked before you erase 3318 the flash, but in some situations (when system RAM is 3319 too limited to allow for a temporary copy of the 3320 downloaded image) this option may be very useful. 3321 3322- CONFIG_SYS_FLASH_CFI: 3323 Define if the flash driver uses extra elements in the 3324 common flash structure for storing flash geometry. 3325 3326- CONFIG_FLASH_CFI_DRIVER 3327 This option also enables the building of the cfi_flash driver 3328 in the drivers directory 3329 3330- CONFIG_FLASH_CFI_MTD 3331 This option enables the building of the cfi_mtd driver 3332 in the drivers directory. The driver exports CFI flash 3333 to the MTD layer. 3334 3335- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3336 Use buffered writes to flash. 3337 3338- CONFIG_FLASH_SPANSION_S29WS_N 3339 s29ws-n MirrorBit flash has non-standard addresses for buffered 3340 write commands. 3341 3342- CONFIG_SYS_FLASH_QUIET_TEST 3343 If this option is defined, the common CFI flash doesn't 3344 print it's warning upon not recognized FLASH banks. This 3345 is useful, if some of the configured banks are only 3346 optionally available. 3347 3348- CONFIG_FLASH_SHOW_PROGRESS 3349 If defined (must be an integer), print out countdown 3350 digits and dots. Recommended value: 45 (9..1) for 80 3351 column displays, 15 (3..1) for 40 column displays. 3352 3353- CONFIG_FLASH_VERIFY 3354 If defined, the content of the flash (destination) is compared 3355 against the source after the write operation. An error message 3356 will be printed when the contents are not identical. 3357 Please note that this option is useless in nearly all cases, 3358 since such flash programming errors usually are detected earlier 3359 while unprotecting/erasing/programming. Please only enable 3360 this option if you really know what you are doing. 3361 3362- CONFIG_SYS_RX_ETH_BUFFER: 3363 Defines the number of Ethernet receive buffers. On some 3364 Ethernet controllers it is recommended to set this value 3365 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3366 buffers can be full shortly after enabling the interface 3367 on high Ethernet traffic. 3368 Defaults to 4 if not defined. 3369 3370- CONFIG_ENV_MAX_ENTRIES 3371 3372 Maximum number of entries in the hash table that is used 3373 internally to store the environment settings. The default 3374 setting is supposed to be generous and should work in most 3375 cases. This setting can be used to tune behaviour; see 3376 lib/hashtable.c for details. 3377 3378- CONFIG_ENV_FLAGS_LIST_DEFAULT 3379- CONFIG_ENV_FLAGS_LIST_STATIC 3380 Enable validation of the values given to environment variables when 3381 calling env set. Variables can be restricted to only decimal, 3382 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3383 the variables can also be restricted to IP address or MAC address. 3384 3385 The format of the list is: 3386 type_attribute = [s|d|x|b|i|m] 3387 access_attribute = [a|r|o|c] 3388 attributes = type_attribute[access_attribute] 3389 entry = variable_name[:attributes] 3390 list = entry[,list] 3391 3392 The type attributes are: 3393 s - String (default) 3394 d - Decimal 3395 x - Hexadecimal 3396 b - Boolean ([1yYtT|0nNfF]) 3397 i - IP address 3398 m - MAC address 3399 3400 The access attributes are: 3401 a - Any (default) 3402 r - Read-only 3403 o - Write-once 3404 c - Change-default 3405 3406 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3407 Define this to a list (string) to define the ".flags" 3408 environment variable in the default or embedded environment. 3409 3410 - CONFIG_ENV_FLAGS_LIST_STATIC 3411 Define this to a list (string) to define validation that 3412 should be done if an entry is not found in the ".flags" 3413 environment variable. To override a setting in the static 3414 list, simply add an entry for the same variable name to the 3415 ".flags" variable. 3416 3417 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3418 regular expression. This allows multiple variables to define the same 3419 flags without explicitly listing them for each variable. 3420 3421- CONFIG_ENV_ACCESS_IGNORE_FORCE 3422 If defined, don't allow the -f switch to env set override variable 3423 access flags. 3424 3425- CONFIG_USE_STDINT 3426 If stdint.h is available with your toolchain you can define this 3427 option to enable it. You can provide option 'USE_STDINT=1' when 3428 building U-Boot to enable this. 3429 3430The following definitions that deal with the placement and management 3431of environment data (variable area); in general, we support the 3432following configurations: 3433 3434- CONFIG_BUILD_ENVCRC: 3435 3436 Builds up envcrc with the target environment so that external utils 3437 may easily extract it and embed it in final U-Boot images. 3438 3439- CONFIG_ENV_IS_IN_FLASH: 3440 3441 Define this if the environment is in flash memory. 3442 3443 a) The environment occupies one whole flash sector, which is 3444 "embedded" in the text segment with the U-Boot code. This 3445 happens usually with "bottom boot sector" or "top boot 3446 sector" type flash chips, which have several smaller 3447 sectors at the start or the end. For instance, such a 3448 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3449 such a case you would place the environment in one of the 3450 4 kB sectors - with U-Boot code before and after it. With 3451 "top boot sector" type flash chips, you would put the 3452 environment in one of the last sectors, leaving a gap 3453 between U-Boot and the environment. 3454 3455 - CONFIG_ENV_OFFSET: 3456 3457 Offset of environment data (variable area) to the 3458 beginning of flash memory; for instance, with bottom boot 3459 type flash chips the second sector can be used: the offset 3460 for this sector is given here. 3461 3462 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3463 3464 - CONFIG_ENV_ADDR: 3465 3466 This is just another way to specify the start address of 3467 the flash sector containing the environment (instead of 3468 CONFIG_ENV_OFFSET). 3469 3470 - CONFIG_ENV_SECT_SIZE: 3471 3472 Size of the sector containing the environment. 3473 3474 3475 b) Sometimes flash chips have few, equal sized, BIG sectors. 3476 In such a case you don't want to spend a whole sector for 3477 the environment. 3478 3479 - CONFIG_ENV_SIZE: 3480 3481 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3482 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3483 of this flash sector for the environment. This saves 3484 memory for the RAM copy of the environment. 3485 3486 It may also save flash memory if you decide to use this 3487 when your environment is "embedded" within U-Boot code, 3488 since then the remainder of the flash sector could be used 3489 for U-Boot code. It should be pointed out that this is 3490 STRONGLY DISCOURAGED from a robustness point of view: 3491 updating the environment in flash makes it always 3492 necessary to erase the WHOLE sector. If something goes 3493 wrong before the contents has been restored from a copy in 3494 RAM, your target system will be dead. 3495 3496 - CONFIG_ENV_ADDR_REDUND 3497 CONFIG_ENV_SIZE_REDUND 3498 3499 These settings describe a second storage area used to hold 3500 a redundant copy of the environment data, so that there is 3501 a valid backup copy in case there is a power failure during 3502 a "saveenv" operation. 3503 3504BE CAREFUL! Any changes to the flash layout, and some changes to the 3505source code will make it necessary to adapt <board>/u-boot.lds* 3506accordingly! 3507 3508 3509- CONFIG_ENV_IS_IN_NVRAM: 3510 3511 Define this if you have some non-volatile memory device 3512 (NVRAM, battery buffered SRAM) which you want to use for the 3513 environment. 3514 3515 - CONFIG_ENV_ADDR: 3516 - CONFIG_ENV_SIZE: 3517 3518 These two #defines are used to determine the memory area you 3519 want to use for environment. It is assumed that this memory 3520 can just be read and written to, without any special 3521 provision. 3522 3523BE CAREFUL! The first access to the environment happens quite early 3524in U-Boot initialization (when we try to get the setting of for the 3525console baudrate). You *MUST* have mapped your NVRAM area then, or 3526U-Boot will hang. 3527 3528Please note that even with NVRAM we still use a copy of the 3529environment in RAM: we could work on NVRAM directly, but we want to 3530keep settings there always unmodified except somebody uses "saveenv" 3531to save the current settings. 3532 3533 3534- CONFIG_ENV_IS_IN_EEPROM: 3535 3536 Use this if you have an EEPROM or similar serial access 3537 device and a driver for it. 3538 3539 - CONFIG_ENV_OFFSET: 3540 - CONFIG_ENV_SIZE: 3541 3542 These two #defines specify the offset and size of the 3543 environment area within the total memory of your EEPROM. 3544 3545 - CONFIG_SYS_I2C_EEPROM_ADDR: 3546 If defined, specified the chip address of the EEPROM device. 3547 The default address is zero. 3548 3549 - CONFIG_SYS_I2C_EEPROM_BUS: 3550 If defined, specified the i2c bus of the EEPROM device. 3551 3552 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3553 If defined, the number of bits used to address bytes in a 3554 single page in the EEPROM device. A 64 byte page, for example 3555 would require six bits. 3556 3557 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3558 If defined, the number of milliseconds to delay between 3559 page writes. The default is zero milliseconds. 3560 3561 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3562 The length in bytes of the EEPROM memory array address. Note 3563 that this is NOT the chip address length! 3564 3565 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3566 EEPROM chips that implement "address overflow" are ones 3567 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3568 address and the extra bits end up in the "chip address" bit 3569 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3570 byte chips. 3571 3572 Note that we consider the length of the address field to 3573 still be one byte because the extra address bits are hidden 3574 in the chip address. 3575 3576 - CONFIG_SYS_EEPROM_SIZE: 3577 The size in bytes of the EEPROM device. 3578 3579 - CONFIG_ENV_EEPROM_IS_ON_I2C 3580 define this, if you have I2C and SPI activated, and your 3581 EEPROM, which holds the environment, is on the I2C bus. 3582 3583 - CONFIG_I2C_ENV_EEPROM_BUS 3584 if you have an Environment on an EEPROM reached over 3585 I2C muxes, you can define here, how to reach this 3586 EEPROM. For example: 3587 3588 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3589 3590 EEPROM which holds the environment, is reached over 3591 a pca9547 i2c mux with address 0x70, channel 3. 3592 3593- CONFIG_ENV_IS_IN_DATAFLASH: 3594 3595 Define this if you have a DataFlash memory device which you 3596 want to use for the environment. 3597 3598 - CONFIG_ENV_OFFSET: 3599 - CONFIG_ENV_ADDR: 3600 - CONFIG_ENV_SIZE: 3601 3602 These three #defines specify the offset and size of the 3603 environment area within the total memory of your DataFlash placed 3604 at the specified address. 3605 3606- CONFIG_ENV_IS_IN_SPI_FLASH: 3607 3608 Define this if you have a SPI Flash memory device which you 3609 want to use for the environment. 3610 3611 - CONFIG_ENV_OFFSET: 3612 - CONFIG_ENV_SIZE: 3613 3614 These two #defines specify the offset and size of the 3615 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3616 aligned to an erase sector boundary. 3617 3618 - CONFIG_ENV_SECT_SIZE: 3619 3620 Define the SPI flash's sector size. 3621 3622 - CONFIG_ENV_OFFSET_REDUND (optional): 3623 3624 This setting describes a second storage area of CONFIG_ENV_SIZE 3625 size used to hold a redundant copy of the environment data, so 3626 that there is a valid backup copy in case there is a power failure 3627 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3628 aligned to an erase sector boundary. 3629 3630 - CONFIG_ENV_SPI_BUS (optional): 3631 - CONFIG_ENV_SPI_CS (optional): 3632 3633 Define the SPI bus and chip select. If not defined they will be 0. 3634 3635 - CONFIG_ENV_SPI_MAX_HZ (optional): 3636 3637 Define the SPI max work clock. If not defined then use 1MHz. 3638 3639 - CONFIG_ENV_SPI_MODE (optional): 3640 3641 Define the SPI work mode. If not defined then use SPI_MODE_3. 3642 3643- CONFIG_ENV_IS_IN_REMOTE: 3644 3645 Define this if you have a remote memory space which you 3646 want to use for the local device's environment. 3647 3648 - CONFIG_ENV_ADDR: 3649 - CONFIG_ENV_SIZE: 3650 3651 These two #defines specify the address and size of the 3652 environment area within the remote memory space. The 3653 local device can get the environment from remote memory 3654 space by SRIO or PCIE links. 3655 3656BE CAREFUL! For some special cases, the local device can not use 3657"saveenv" command. For example, the local device will get the 3658environment stored in a remote NOR flash by SRIO or PCIE link, 3659but it can not erase, write this NOR flash by SRIO or PCIE interface. 3660 3661- CONFIG_ENV_IS_IN_NAND: 3662 3663 Define this if you have a NAND device which you want to use 3664 for the environment. 3665 3666 - CONFIG_ENV_OFFSET: 3667 - CONFIG_ENV_SIZE: 3668 3669 These two #defines specify the offset and size of the environment 3670 area within the first NAND device. CONFIG_ENV_OFFSET must be 3671 aligned to an erase block boundary. 3672 3673 - CONFIG_ENV_OFFSET_REDUND (optional): 3674 3675 This setting describes a second storage area of CONFIG_ENV_SIZE 3676 size used to hold a redundant copy of the environment data, so 3677 that there is a valid backup copy in case there is a power failure 3678 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3679 aligned to an erase block boundary. 3680 3681 - CONFIG_ENV_RANGE (optional): 3682 3683 Specifies the length of the region in which the environment 3684 can be written. This should be a multiple of the NAND device's 3685 block size. Specifying a range with more erase blocks than 3686 are needed to hold CONFIG_ENV_SIZE allows bad blocks within 3687 the range to be avoided. 3688 3689 - CONFIG_ENV_OFFSET_OOB (optional): 3690 3691 Enables support for dynamically retrieving the offset of the 3692 environment from block zero's out-of-band data. The 3693 "nand env.oob" command can be used to record this offset. 3694 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when 3695 using CONFIG_ENV_OFFSET_OOB. 3696 3697- CONFIG_NAND_ENV_DST 3698 3699 Defines address in RAM to which the nand_spl code should copy the 3700 environment. If redundant environment is used, it will be copied to 3701 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3702 3703- CONFIG_ENV_IS_IN_UBI: 3704 3705 Define this if you have an UBI volume that you want to use for the 3706 environment. This has the benefit of wear-leveling the environment 3707 accesses, which is important on NAND. 3708 3709 - CONFIG_ENV_UBI_PART: 3710 3711 Define this to a string that is the mtd partition containing the UBI. 3712 3713 - CONFIG_ENV_UBI_VOLUME: 3714 3715 Define this to the name of the volume that you want to store the 3716 environment in. 3717 3718 - CONFIG_ENV_UBI_VOLUME_REDUND: 3719 3720 Define this to the name of another volume to store a second copy of 3721 the environment in. This will enable redundant environments in UBI. 3722 It is assumed that both volumes are in the same MTD partition. 3723 3724 - CONFIG_UBI_SILENCE_MSG 3725 - CONFIG_UBIFS_SILENCE_MSG 3726 3727 You will probably want to define these to avoid a really noisy system 3728 when storing the env in UBI. 3729 3730- CONFIG_ENV_IS_IN_FAT: 3731 Define this if you want to use the FAT file system for the environment. 3732 3733 - FAT_ENV_INTERFACE: 3734 3735 Define this to a string that is the name of the block device. 3736 3737 - FAT_ENV_DEVICE_AND_PART: 3738 3739 Define this to a string to specify the partition of the device. It can 3740 be as following: 3741 3742 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3743 - "D:P": device D partition P. Error occurs if device D has no 3744 partition table. 3745 - "D:0": device D. 3746 - "D" or "D:": device D partition 1 if device D has partition 3747 table, or the whole device D if has no partition 3748 table. 3749 - "D:auto": first partition in device D with bootable flag set. 3750 If none, first valid partition in device D. If no 3751 partition table then means device D. 3752 3753 - FAT_ENV_FILE: 3754 3755 It's a string of the FAT file name. This file use to store the 3756 environment. 3757 3758 - CONFIG_FAT_WRITE: 3759 This must be enabled. Otherwise it cannot save the environment file. 3760 3761- CONFIG_ENV_IS_IN_MMC: 3762 3763 Define this if you have an MMC device which you want to use for the 3764 environment. 3765 3766 - CONFIG_SYS_MMC_ENV_DEV: 3767 3768 Specifies which MMC device the environment is stored in. 3769 3770 - CONFIG_SYS_MMC_ENV_PART (optional): 3771 3772 Specifies which MMC partition the environment is stored in. If not 3773 set, defaults to partition 0, the user area. Common values might be 3774 1 (first MMC boot partition), 2 (second MMC boot partition). 3775 3776 - CONFIG_ENV_OFFSET: 3777 - CONFIG_ENV_SIZE: 3778 3779 These two #defines specify the offset and size of the environment 3780 area within the specified MMC device. 3781 3782 If offset is positive (the usual case), it is treated as relative to 3783 the start of the MMC partition. If offset is negative, it is treated 3784 as relative to the end of the MMC partition. This can be useful if 3785 your board may be fitted with different MMC devices, which have 3786 different sizes for the MMC partitions, and you always want the 3787 environment placed at the very end of the partition, to leave the 3788 maximum possible space before it, to store other data. 3789 3790 These two values are in units of bytes, but must be aligned to an 3791 MMC sector boundary. 3792 3793 - CONFIG_ENV_OFFSET_REDUND (optional): 3794 3795 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to 3796 hold a redundant copy of the environment data. This provides a 3797 valid backup copy in case the other copy is corrupted, e.g. due 3798 to a power failure during a "saveenv" operation. 3799 3800 This value may also be positive or negative; this is handled in the 3801 same way as CONFIG_ENV_OFFSET. 3802 3803 This value is also in units of bytes, but must also be aligned to 3804 an MMC sector boundary. 3805 3806 - CONFIG_ENV_SIZE_REDUND (optional): 3807 3808 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is 3809 set. If this value is set, it must be set to the same value as 3810 CONFIG_ENV_SIZE. 3811 3812Please note that the environment is read-only until the monitor 3813has been relocated to RAM and a RAM copy of the environment has been 3814created; also, when using EEPROM you will have to use getenv_f() 3815until then to read environment variables. 3816 3817The environment is protected by a CRC32 checksum. Before the monitor 3818is relocated into RAM, as a result of a bad CRC you will be working 3819with the compiled-in default environment - *silently*!!! [This is 3820necessary, because the first environment variable we need is the 3821"baudrate" setting for the console - if we have a bad CRC, we don't 3822have any device yet where we could complain.] 3823 3824Note: once the monitor has been relocated, then it will complain if 3825the default environment is used; a new CRC is computed as soon as you 3826use the "saveenv" command to store a valid environment. 3827 3828- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3829 Echo the inverted Ethernet link state to the fault LED. 3830 3831 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3832 also needs to be defined. 3833 3834- CONFIG_SYS_FAULT_MII_ADDR: 3835 MII address of the PHY to check for the Ethernet link state. 3836 3837- CONFIG_NS16550_MIN_FUNCTIONS: 3838 Define this if you desire to only have use of the NS16550_init 3839 and NS16550_putc functions for the serial driver located at 3840 drivers/serial/ns16550.c. This option is useful for saving 3841 space for already greatly restricted images, including but not 3842 limited to NAND_SPL configurations. 3843 3844- CONFIG_DISPLAY_BOARDINFO 3845 Display information about the board that U-Boot is running on 3846 when U-Boot starts up. The board function checkboard() is called 3847 to do this. 3848 3849- CONFIG_DISPLAY_BOARDINFO_LATE 3850 Similar to the previous option, but display this information 3851 later, once stdio is running and output goes to the LCD, if 3852 present. 3853 3854- CONFIG_BOARD_SIZE_LIMIT: 3855 Maximum size of the U-Boot image. When defined, the 3856 build system checks that the actual size does not 3857 exceed it. 3858 3859Low Level (hardware related) configuration options: 3860--------------------------------------------------- 3861 3862- CONFIG_SYS_CACHELINE_SIZE: 3863 Cache Line Size of the CPU. 3864 3865- CONFIG_SYS_CCSRBAR_DEFAULT: 3866 Default (power-on reset) physical address of CCSR on Freescale 3867 PowerPC SOCs. 3868 3869- CONFIG_SYS_CCSRBAR: 3870 Virtual address of CCSR. On a 32-bit build, this is typically 3871 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3872 3873- CONFIG_SYS_CCSRBAR_PHYS: 3874 Physical address of CCSR. CCSR can be relocated to a new 3875 physical address, if desired. In this case, this macro should 3876 be set to that address. Otherwise, it should be set to the 3877 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3878 is typically relocated on 36-bit builds. It is recommended 3879 that this macro be defined via the _HIGH and _LOW macros: 3880 3881 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3882 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3883 3884- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3885 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3886 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3887 used in assembly code, so it must not contain typecasts or 3888 integer size suffixes (e.g. "ULL"). 3889 3890- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3891 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3892 used in assembly code, so it must not contain typecasts or 3893 integer size suffixes (e.g. "ULL"). 3894 3895- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3896 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3897 forced to a value that ensures that CCSR is not relocated. 3898 3899- Floppy Disk Support: 3900 CONFIG_SYS_FDC_DRIVE_NUMBER 3901 3902 the default drive number (default value 0) 3903 3904 CONFIG_SYS_ISA_IO_STRIDE 3905 3906 defines the spacing between FDC chipset registers 3907 (default value 1) 3908 3909 CONFIG_SYS_ISA_IO_OFFSET 3910 3911 defines the offset of register from address. It 3912 depends on which part of the data bus is connected to 3913 the FDC chipset. (default value 0) 3914 3915 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3916 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3917 default value. 3918 3919 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3920 fdc_hw_init() is called at the beginning of the FDC 3921 setup. fdc_hw_init() must be provided by the board 3922 source code. It is used to make hardware-dependent 3923 initializations. 3924 3925- CONFIG_IDE_AHB: 3926 Most IDE controllers were designed to be connected with PCI 3927 interface. Only few of them were designed for AHB interface. 3928 When software is doing ATA command and data transfer to 3929 IDE devices through IDE-AHB controller, some additional 3930 registers accessing to these kind of IDE-AHB controller 3931 is required. 3932 3933- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3934 DO NOT CHANGE unless you know exactly what you're 3935 doing! (11-4) [82xx systems only] 3936 3937- CONFIG_SYS_INIT_RAM_ADDR: 3938 3939 Start address of memory area that can be used for 3940 initial data and stack; please note that this must be 3941 writable memory that is working WITHOUT special 3942 initialization, i. e. you CANNOT use normal RAM which 3943 will become available only after programming the 3944 memory controller and running certain initialization 3945 sequences. 3946 3947 U-Boot uses the following memory types: 3948 3949- CONFIG_SYS_GBL_DATA_OFFSET: 3950 3951 Offset of the initial data structure in the memory 3952 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3953 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3954 data is located at the end of the available space 3955 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3956 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3957 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3958 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3959 3960 Note: 3961 On the MPC824X (or other systems that use the data 3962 cache for initial memory) the address chosen for 3963 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3964 point to an otherwise UNUSED address space between 3965 the top of RAM and the start of the PCI space. 3966 3967- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3968 3969- CONFIG_SYS_OR_TIMING_SDRAM: 3970 SDRAM timing 3971 3972- CONFIG_SYS_MAMR_PTA: 3973 periodic timer for refresh 3974 3975- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3976 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3977 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3978 CONFIG_SYS_BR1_PRELIM: 3979 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3980 3981- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3982 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3983 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3984 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3985 3986- CONFIG_PCI_ENUM_ONLY 3987 Only scan through and get the devices on the buses. 3988 Don't do any setup work, presumably because someone or 3989 something has already done it, and we don't need to do it 3990 a second time. Useful for platforms that are pre-booted 3991 by coreboot or similar. 3992 3993- CONFIG_PCI_INDIRECT_BRIDGE: 3994 Enable support for indirect PCI bridges. 3995 3996- CONFIG_SYS_SRIO: 3997 Chip has SRIO or not 3998 3999- CONFIG_SRIO1: 4000 Board has SRIO 1 port available 4001 4002- CONFIG_SRIO2: 4003 Board has SRIO 2 port available 4004 4005- CONFIG_SRIO_PCIE_BOOT_MASTER 4006 Board can support master function for Boot from SRIO and PCIE 4007 4008- CONFIG_SYS_SRIOn_MEM_VIRT: 4009 Virtual Address of SRIO port 'n' memory region 4010 4011- CONFIG_SYS_SRIOn_MEM_PHYS: 4012 Physical Address of SRIO port 'n' memory region 4013 4014- CONFIG_SYS_SRIOn_MEM_SIZE: 4015 Size of SRIO port 'n' memory region 4016 4017- CONFIG_SYS_NAND_BUSWIDTH_16BIT 4018 Defined to tell the NAND controller that the NAND chip is using 4019 a 16 bit bus. 4020 Not all NAND drivers use this symbol. 4021 Example of drivers that use it: 4022 - drivers/mtd/nand/ndfc.c 4023 - drivers/mtd/nand/mxc_nand.c 4024 4025- CONFIG_SYS_NDFC_EBC0_CFG 4026 Sets the EBC0_CFG register for the NDFC. If not defined 4027 a default value will be used. 4028 4029- CONFIG_SPD_EEPROM 4030 Get DDR timing information from an I2C EEPROM. Common 4031 with pluggable memory modules such as SODIMMs 4032 4033 SPD_EEPROM_ADDRESS 4034 I2C address of the SPD EEPROM 4035 4036- CONFIG_SYS_SPD_BUS_NUM 4037 If SPD EEPROM is on an I2C bus other than the first 4038 one, specify here. Note that the value must resolve 4039 to something your driver can deal with. 4040 4041- CONFIG_SYS_DDR_RAW_TIMING 4042 Get DDR timing information from other than SPD. Common with 4043 soldered DDR chips onboard without SPD. DDR raw timing 4044 parameters are extracted from datasheet and hard-coded into 4045 header files or board specific files. 4046 4047- CONFIG_FSL_DDR_INTERACTIVE 4048 Enable interactive DDR debugging. See doc/README.fsl-ddr. 4049 4050- CONFIG_FSL_DDR_SYNC_REFRESH 4051 Enable sync of refresh for multiple controllers. 4052 4053- CONFIG_FSL_DDR_BIST 4054 Enable built-in memory test for Freescale DDR controllers. 4055 4056- CONFIG_SYS_83XX_DDR_USES_CS0 4057 Only for 83xx systems. If specified, then DDR should 4058 be configured using CS0 and CS1 instead of CS2 and CS3. 4059 4060- CONFIG_RMII 4061 Enable RMII mode for all FECs. 4062 Note that this is a global option, we can't 4063 have one FEC in standard MII mode and another in RMII mode. 4064 4065- CONFIG_CRC32_VERIFY 4066 Add a verify option to the crc32 command. 4067 The syntax is: 4068 4069 => crc32 -v <address> <count> <crc32> 4070 4071 Where address/count indicate a memory area 4072 and crc32 is the correct crc32 which the 4073 area should have. 4074 4075- CONFIG_LOOPW 4076 Add the "loopw" memory command. This only takes effect if 4077 the memory commands are activated globally (CONFIG_CMD_MEM). 4078 4079- CONFIG_MX_CYCLIC 4080 Add the "mdc" and "mwc" memory commands. These are cyclic 4081 "md/mw" commands. 4082 Examples: 4083 4084 => mdc.b 10 4 500 4085 This command will print 4 bytes (10,11,12,13) each 500 ms. 4086 4087 => mwc.l 100 12345678 10 4088 This command will write 12345678 to address 100 all 10 ms. 4089 4090 This only takes effect if the memory commands are activated 4091 globally (CONFIG_CMD_MEM). 4092 4093- CONFIG_SKIP_LOWLEVEL_INIT 4094 [ARM, NDS32, MIPS only] If this variable is defined, then certain 4095 low level initializations (like setting up the memory 4096 controller) are omitted and/or U-Boot does not 4097 relocate itself into RAM. 4098 4099 Normally this variable MUST NOT be defined. The only 4100 exception is when U-Boot is loaded (to RAM) by some 4101 other boot loader or by a debugger which performs 4102 these initializations itself. 4103 4104- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 4105 [ARM926EJ-S only] This allows just the call to lowlevel_init() 4106 to be skipped. The normal CP15 init (such as enabling the 4107 instruction cache) is still performed. 4108 4109- CONFIG_SPL_BUILD 4110 Modifies the behaviour of start.S when compiling a loader 4111 that is executed before the actual U-Boot. E.g. when 4112 compiling a NAND SPL. 4113 4114- CONFIG_TPL_BUILD 4115 Modifies the behaviour of start.S when compiling a loader 4116 that is executed after the SPL and before the actual U-Boot. 4117 It is loaded by the SPL. 4118 4119- CONFIG_SYS_MPC85XX_NO_RESETVEC 4120 Only for 85xx systems. If this variable is specified, the section 4121 .resetvec is not kept and the section .bootpg is placed in the 4122 previous 4k of the .text section. 4123 4124- CONFIG_ARCH_MAP_SYSMEM 4125 Generally U-Boot (and in particular the md command) uses 4126 effective address. It is therefore not necessary to regard 4127 U-Boot address as virtual addresses that need to be translated 4128 to physical addresses. However, sandbox requires this, since 4129 it maintains its own little RAM buffer which contains all 4130 addressable memory. This option causes some memory accesses 4131 to be mapped through map_sysmem() / unmap_sysmem(). 4132 4133- CONFIG_X86_RESET_VECTOR 4134 If defined, the x86 reset vector code is included. This is not 4135 needed when U-Boot is running from Coreboot. 4136 4137- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4138 Enables the RTC32K OSC on AM33xx based plattforms 4139 4140- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4141 Option to disable subpage write in NAND driver 4142 driver that uses this: 4143 drivers/mtd/nand/davinci_nand.c 4144 4145Freescale QE/FMAN Firmware Support: 4146----------------------------------- 4147 4148The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4149loading of "firmware", which is encoded in the QE firmware binary format. 4150This firmware often needs to be loaded during U-Boot booting, so macros 4151are used to identify the storage device (NOR flash, SPI, etc) and the address 4152within that device. 4153 4154- CONFIG_SYS_FMAN_FW_ADDR 4155 The address in the storage device where the FMAN microcode is located. The 4156 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4157 is also specified. 4158 4159- CONFIG_SYS_QE_FW_ADDR 4160 The address in the storage device where the QE microcode is located. The 4161 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4162 is also specified. 4163 4164- CONFIG_SYS_QE_FMAN_FW_LENGTH 4165 The maximum possible size of the firmware. The firmware binary format 4166 has a field that specifies the actual size of the firmware, but it 4167 might not be possible to read any part of the firmware unless some 4168 local storage is allocated to hold the entire firmware first. 4169 4170- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4171 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4172 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4173 virtual address in NOR flash. 4174 4175- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4176 Specifies that QE/FMAN firmware is located in NAND flash. 4177 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4178 4179- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4180 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4181 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4182 4183- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4184 Specifies that QE/FMAN firmware is located in the remote (master) 4185 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4186 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4187 window->master inbound window->master LAW->the ucode address in 4188 master's memory space. 4189 4190Freescale Layerscape Management Complex Firmware Support: 4191--------------------------------------------------------- 4192The Freescale Layerscape Management Complex (MC) supports the loading of 4193"firmware". 4194This firmware often needs to be loaded during U-Boot booting, so macros 4195are used to identify the storage device (NOR flash, SPI, etc) and the address 4196within that device. 4197 4198- CONFIG_FSL_MC_ENET 4199 Enable the MC driver for Layerscape SoCs. 4200 4201Freescale Layerscape Debug Server Support: 4202------------------------------------------- 4203The Freescale Layerscape Debug Server Support supports the loading of 4204"Debug Server firmware" and triggering SP boot-rom. 4205This firmware often needs to be loaded during U-Boot booting. 4206 4207- CONFIG_SYS_MC_RSV_MEM_ALIGN 4208 Define alignment of reserved memory MC requires 4209 4210Reproducible builds 4211------------------- 4212 4213In order to achieve reproducible builds, timestamps used in the U-Boot build 4214process have to be set to a fixed value. 4215 4216This is done using the SOURCE_DATE_EPOCH environment variable. 4217SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4218option for U-Boot or an environment variable in U-Boot. 4219 4220SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4221 4222Building the Software: 4223====================== 4224 4225Building U-Boot has been tested in several native build environments 4226and in many different cross environments. Of course we cannot support 4227all possibly existing versions of cross development tools in all 4228(potentially obsolete) versions. In case of tool chain problems we 4229recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4230which is extensively used to build and test U-Boot. 4231 4232If you are not using a native environment, it is assumed that you 4233have GNU cross compiling tools available in your path. In this case, 4234you must set the environment variable CROSS_COMPILE in your shell. 4235Note that no changes to the Makefile or any other source files are 4236necessary. For example using the ELDK on a 4xx CPU, please enter: 4237 4238 $ CROSS_COMPILE=ppc_4xx- 4239 $ export CROSS_COMPILE 4240 4241Note: If you wish to generate Windows versions of the utilities in 4242 the tools directory you can use the MinGW toolchain 4243 (http://www.mingw.org). Set your HOST tools to the MinGW 4244 toolchain and execute 'make tools'. For example: 4245 4246 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4247 4248 Binaries such as tools/mkimage.exe will be created which can 4249 be executed on computers running Windows. 4250 4251U-Boot is intended to be simple to build. After installing the 4252sources you must configure U-Boot for one specific board type. This 4253is done by typing: 4254 4255 make NAME_defconfig 4256 4257where "NAME_defconfig" is the name of one of the existing configu- 4258rations; see boards.cfg for supported names. 4259 4260Note: for some board special configuration names may exist; check if 4261 additional information is available from the board vendor; for 4262 instance, the TQM823L systems are available without (standard) 4263 or with LCD support. You can select such additional "features" 4264 when choosing the configuration, i. e. 4265 4266 make TQM823L_defconfig 4267 - will configure for a plain TQM823L, i. e. no LCD support 4268 4269 make TQM823L_LCD_defconfig 4270 - will configure for a TQM823L with U-Boot console on LCD 4271 4272 etc. 4273 4274 4275Finally, type "make all", and you should get some working U-Boot 4276images ready for download to / installation on your system: 4277 4278- "u-boot.bin" is a raw binary image 4279- "u-boot" is an image in ELF binary format 4280- "u-boot.srec" is in Motorola S-Record format 4281 4282By default the build is performed locally and the objects are saved 4283in the source directory. One of the two methods can be used to change 4284this behavior and build U-Boot to some external directory: 4285 42861. Add O= to the make command line invocations: 4287 4288 make O=/tmp/build distclean 4289 make O=/tmp/build NAME_defconfig 4290 make O=/tmp/build all 4291 42922. Set environment variable KBUILD_OUTPUT to point to the desired location: 4293 4294 export KBUILD_OUTPUT=/tmp/build 4295 make distclean 4296 make NAME_defconfig 4297 make all 4298 4299Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4300variable. 4301 4302 4303Please be aware that the Makefiles assume you are using GNU make, so 4304for instance on NetBSD you might need to use "gmake" instead of 4305native "make". 4306 4307 4308If the system board that you have is not listed, then you will need 4309to port U-Boot to your hardware platform. To do this, follow these 4310steps: 4311 43121. Create a new directory to hold your board specific code. Add any 4313 files you need. In your board directory, you will need at least 4314 the "Makefile" and a "<board>.c". 43152. Create a new configuration file "include/configs/<board>.h" for 4316 your board. 43173. If you're porting U-Boot to a new CPU, then also create a new 4318 directory to hold your CPU specific code. Add any files you need. 43194. Run "make <board>_defconfig" with your new name. 43205. Type "make", and you should get a working "u-boot.srec" file 4321 to be installed on your target system. 43226. Debug and solve any problems that might arise. 4323 [Of course, this last step is much harder than it sounds.] 4324 4325 4326Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4327============================================================== 4328 4329If you have modified U-Boot sources (for instance added a new board 4330or support for new devices, a new CPU, etc.) you are expected to 4331provide feedback to the other developers. The feedback normally takes 4332the form of a "patch", i. e. a context diff against a certain (latest 4333official or latest in the git repository) version of U-Boot sources. 4334 4335But before you submit such a patch, please verify that your modifi- 4336cation did not break existing code. At least make sure that *ALL* of 4337the supported boards compile WITHOUT ANY compiler warnings. To do so, 4338just run the buildman script (tools/buildman/buildman), which will 4339configure and build U-Boot for ALL supported system. Be warned, this 4340will take a while. Please see the buildman README, or run 'buildman -H' 4341for documentation. 4342 4343 4344See also "U-Boot Porting Guide" below. 4345 4346 4347Monitor Commands - Overview: 4348============================ 4349 4350go - start application at address 'addr' 4351run - run commands in an environment variable 4352bootm - boot application image from memory 4353bootp - boot image via network using BootP/TFTP protocol 4354bootz - boot zImage from memory 4355tftpboot- boot image via network using TFTP protocol 4356 and env variables "ipaddr" and "serverip" 4357 (and eventually "gatewayip") 4358tftpput - upload a file via network using TFTP protocol 4359rarpboot- boot image via network using RARP/TFTP protocol 4360diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4361loads - load S-Record file over serial line 4362loadb - load binary file over serial line (kermit mode) 4363md - memory display 4364mm - memory modify (auto-incrementing) 4365nm - memory modify (constant address) 4366mw - memory write (fill) 4367cp - memory copy 4368cmp - memory compare 4369crc32 - checksum calculation 4370i2c - I2C sub-system 4371sspi - SPI utility commands 4372base - print or set address offset 4373printenv- print environment variables 4374setenv - set environment variables 4375saveenv - save environment variables to persistent storage 4376protect - enable or disable FLASH write protection 4377erase - erase FLASH memory 4378flinfo - print FLASH memory information 4379nand - NAND memory operations (see doc/README.nand) 4380bdinfo - print Board Info structure 4381iminfo - print header information for application image 4382coninfo - print console devices and informations 4383ide - IDE sub-system 4384loop - infinite loop on address range 4385loopw - infinite write loop on address range 4386mtest - simple RAM test 4387icache - enable or disable instruction cache 4388dcache - enable or disable data cache 4389reset - Perform RESET of the CPU 4390echo - echo args to console 4391version - print monitor version 4392help - print online help 4393? - alias for 'help' 4394 4395 4396Monitor Commands - Detailed Description: 4397======================================== 4398 4399TODO. 4400 4401For now: just type "help <command>". 4402 4403 4404Environment Variables: 4405====================== 4406 4407U-Boot supports user configuration using Environment Variables which 4408can be made persistent by saving to Flash memory. 4409 4410Environment Variables are set using "setenv", printed using 4411"printenv", and saved to Flash using "saveenv". Using "setenv" 4412without a value can be used to delete a variable from the 4413environment. As long as you don't save the environment you are 4414working with an in-memory copy. In case the Flash area containing the 4415environment is erased by accident, a default environment is provided. 4416 4417Some configuration options can be set using Environment Variables. 4418 4419List of environment variables (most likely not complete): 4420 4421 baudrate - see CONFIG_BAUDRATE 4422 4423 bootdelay - see CONFIG_BOOTDELAY 4424 4425 bootcmd - see CONFIG_BOOTCOMMAND 4426 4427 bootargs - Boot arguments when booting an RTOS image 4428 4429 bootfile - Name of the image to load with TFTP 4430 4431 bootm_low - Memory range available for image processing in the bootm 4432 command can be restricted. This variable is given as 4433 a hexadecimal number and defines lowest address allowed 4434 for use by the bootm command. See also "bootm_size" 4435 environment variable. Address defined by "bootm_low" is 4436 also the base of the initial memory mapping for the Linux 4437 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4438 bootm_mapsize. 4439 4440 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4441 This variable is given as a hexadecimal number and it 4442 defines the size of the memory region starting at base 4443 address bootm_low that is accessible by the Linux kernel 4444 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4445 as the default value if it is defined, and bootm_size is 4446 used otherwise. 4447 4448 bootm_size - Memory range available for image processing in the bootm 4449 command can be restricted. This variable is given as 4450 a hexadecimal number and defines the size of the region 4451 allowed for use by the bootm command. See also "bootm_low" 4452 environment variable. 4453 4454 updatefile - Location of the software update file on a TFTP server, used 4455 by the automatic software update feature. Please refer to 4456 documentation in doc/README.update for more details. 4457 4458 autoload - if set to "no" (any string beginning with 'n'), 4459 "bootp" will just load perform a lookup of the 4460 configuration from the BOOTP server, but not try to 4461 load any image using TFTP 4462 4463 autostart - if set to "yes", an image loaded using the "bootp", 4464 "rarpboot", "tftpboot" or "diskboot" commands will 4465 be automatically started (by internally calling 4466 "bootm") 4467 4468 If set to "no", a standalone image passed to the 4469 "bootm" command will be copied to the load address 4470 (and eventually uncompressed), but NOT be started. 4471 This can be used to load and uncompress arbitrary 4472 data. 4473 4474 fdt_high - if set this restricts the maximum address that the 4475 flattened device tree will be copied into upon boot. 4476 For example, if you have a system with 1 GB memory 4477 at physical address 0x10000000, while Linux kernel 4478 only recognizes the first 704 MB as low memory, you 4479 may need to set fdt_high as 0x3C000000 to have the 4480 device tree blob be copied to the maximum address 4481 of the 704 MB low memory, so that Linux kernel can 4482 access it during the boot procedure. 4483 4484 If this is set to the special value 0xFFFFFFFF then 4485 the fdt will not be copied at all on boot. For this 4486 to work it must reside in writable memory, have 4487 sufficient padding on the end of it for u-boot to 4488 add the information it needs into it, and the memory 4489 must be accessible by the kernel. 4490 4491 fdtcontroladdr- if set this is the address of the control flattened 4492 device tree used by U-Boot when CONFIG_OF_CONTROL is 4493 defined. 4494 4495 i2cfast - (PPC405GP|PPC405EP only) 4496 if set to 'y' configures Linux I2C driver for fast 4497 mode (400kHZ). This environment variable is used in 4498 initialization code. So, for changes to be effective 4499 it must be saved and board must be reset. 4500 4501 initrd_high - restrict positioning of initrd images: 4502 If this variable is not set, initrd images will be 4503 copied to the highest possible address in RAM; this 4504 is usually what you want since it allows for 4505 maximum initrd size. If for some reason you want to 4506 make sure that the initrd image is loaded below the 4507 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4508 variable to a value of "no" or "off" or "0". 4509 Alternatively, you can set it to a maximum upper 4510 address to use (U-Boot will still check that it 4511 does not overwrite the U-Boot stack and data). 4512 4513 For instance, when you have a system with 16 MB 4514 RAM, and want to reserve 4 MB from use by Linux, 4515 you can do this by adding "mem=12M" to the value of 4516 the "bootargs" variable. However, now you must make 4517 sure that the initrd image is placed in the first 4518 12 MB as well - this can be done with 4519 4520 setenv initrd_high 00c00000 4521 4522 If you set initrd_high to 0xFFFFFFFF, this is an 4523 indication to U-Boot that all addresses are legal 4524 for the Linux kernel, including addresses in flash 4525 memory. In this case U-Boot will NOT COPY the 4526 ramdisk at all. This may be useful to reduce the 4527 boot time on your system, but requires that this 4528 feature is supported by your Linux kernel. 4529 4530 ipaddr - IP address; needed for tftpboot command 4531 4532 loadaddr - Default load address for commands like "bootp", 4533 "rarpboot", "tftpboot", "loadb" or "diskboot" 4534 4535 loads_echo - see CONFIG_LOADS_ECHO 4536 4537 serverip - TFTP server IP address; needed for tftpboot command 4538 4539 bootretry - see CONFIG_BOOT_RETRY_TIME 4540 4541 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4542 4543 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4544 4545 ethprime - controls which interface is used first. 4546 4547 ethact - controls which interface is currently active. 4548 For example you can do the following 4549 4550 => setenv ethact FEC 4551 => ping 192.168.0.1 # traffic sent on FEC 4552 => setenv ethact SCC 4553 => ping 10.0.0.1 # traffic sent on SCC 4554 4555 ethrotate - When set to "no" U-Boot does not go through all 4556 available network interfaces. 4557 It just stays at the currently selected interface. 4558 4559 netretry - When set to "no" each network operation will 4560 either succeed or fail without retrying. 4561 When set to "once" the network operation will 4562 fail when all the available network interfaces 4563 are tried once without success. 4564 Useful on scripts which control the retry operation 4565 themselves. 4566 4567 npe_ucode - set load address for the NPE microcode 4568 4569 silent_linux - If set then Linux will be told to boot silently, by 4570 changing the console to be empty. If "yes" it will be 4571 made silent. If "no" it will not be made silent. If 4572 unset, then it will be made silent if the U-Boot console 4573 is silent. 4574 4575 tftpsrcp - If this is set, the value is used for TFTP's 4576 UDP source port. 4577 4578 tftpdstp - If this is set, the value is used for TFTP's UDP 4579 destination port instead of the Well Know Port 69. 4580 4581 tftpblocksize - Block size to use for TFTP transfers; if not set, 4582 we use the TFTP server's default block size 4583 4584 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4585 seconds, minimum value is 1000 = 1 second). Defines 4586 when a packet is considered to be lost so it has to 4587 be retransmitted. The default is 5000 = 5 seconds. 4588 Lowering this value may make downloads succeed 4589 faster in networks with high packet loss rates or 4590 with unreliable TFTP servers. 4591 4592 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4593 unit, minimum value = 0). Defines how many timeouts 4594 can happen during a single file transfer before that 4595 transfer is aborted. The default is 10, and 0 means 4596 'no timeouts allowed'. Increasing this value may help 4597 downloads succeed with high packet loss rates, or with 4598 unreliable TFTP servers or client hardware. 4599 4600 vlan - When set to a value < 4095 the traffic over 4601 Ethernet is encapsulated/received over 802.1q 4602 VLAN tagged frames. 4603 4604 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4605 Unsigned value, in milliseconds. If not set, the period will 4606 be either the default (28000), or a value based on 4607 CONFIG_NET_RETRY_COUNT, if defined. This value has 4608 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4609 4610The following image location variables contain the location of images 4611used in booting. The "Image" column gives the role of the image and is 4612not an environment variable name. The other columns are environment 4613variable names. "File Name" gives the name of the file on a TFTP 4614server, "RAM Address" gives the location in RAM the image will be 4615loaded to, and "Flash Location" gives the image's address in NOR 4616flash or offset in NAND flash. 4617 4618*Note* - these variables don't have to be defined for all boards, some 4619boards currently use other variables for these purposes, and some 4620boards use these variables for other purposes. 4621 4622Image File Name RAM Address Flash Location 4623----- --------- ----------- -------------- 4624u-boot u-boot u-boot_addr_r u-boot_addr 4625Linux kernel bootfile kernel_addr_r kernel_addr 4626device tree blob fdtfile fdt_addr_r fdt_addr 4627ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4628 4629The following environment variables may be used and automatically 4630updated by the network boot commands ("bootp" and "rarpboot"), 4631depending the information provided by your boot server: 4632 4633 bootfile - see above 4634 dnsip - IP address of your Domain Name Server 4635 dnsip2 - IP address of your secondary Domain Name Server 4636 gatewayip - IP address of the Gateway (Router) to use 4637 hostname - Target hostname 4638 ipaddr - see above 4639 netmask - Subnet Mask 4640 rootpath - Pathname of the root filesystem on the NFS server 4641 serverip - see above 4642 4643 4644There are two special Environment Variables: 4645 4646 serial# - contains hardware identification information such 4647 as type string and/or serial number 4648 ethaddr - Ethernet address 4649 4650These variables can be set only once (usually during manufacturing of 4651the board). U-Boot refuses to delete or overwrite these variables 4652once they have been set once. 4653 4654 4655Further special Environment Variables: 4656 4657 ver - Contains the U-Boot version string as printed 4658 with the "version" command. This variable is 4659 readonly (see CONFIG_VERSION_VARIABLE). 4660 4661 4662Please note that changes to some configuration parameters may take 4663only effect after the next boot (yes, that's just like Windoze :-). 4664 4665 4666Callback functions for environment variables: 4667--------------------------------------------- 4668 4669For some environment variables, the behavior of u-boot needs to change 4670when their values are changed. This functionality allows functions to 4671be associated with arbitrary variables. On creation, overwrite, or 4672deletion, the callback will provide the opportunity for some side 4673effect to happen or for the change to be rejected. 4674 4675The callbacks are named and associated with a function using the 4676U_BOOT_ENV_CALLBACK macro in your board or driver code. 4677 4678These callbacks are associated with variables in one of two ways. The 4679static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4680in the board configuration to a string that defines a list of 4681associations. The list must be in the following format: 4682 4683 entry = variable_name[:callback_name] 4684 list = entry[,list] 4685 4686If the callback name is not specified, then the callback is deleted. 4687Spaces are also allowed anywhere in the list. 4688 4689Callbacks can also be associated by defining the ".callbacks" variable 4690with the same list format above. Any association in ".callbacks" will 4691override any association in the static list. You can define 4692CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4693".callbacks" environment variable in the default or embedded environment. 4694 4695If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4696regular expression. This allows multiple variables to be connected to 4697the same callback without explicitly listing them all out. 4698 4699 4700Command Line Parsing: 4701===================== 4702 4703There are two different command line parsers available with U-Boot: 4704the old "simple" one, and the much more powerful "hush" shell: 4705 4706Old, simple command line parser: 4707-------------------------------- 4708 4709- supports environment variables (through setenv / saveenv commands) 4710- several commands on one line, separated by ';' 4711- variable substitution using "... ${name} ..." syntax 4712- special characters ('$', ';') can be escaped by prefixing with '\', 4713 for example: 4714 setenv bootcmd bootm \${address} 4715- You can also escape text by enclosing in single apostrophes, for example: 4716 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4717 4718Hush shell: 4719----------- 4720 4721- similar to Bourne shell, with control structures like 4722 if...then...else...fi, for...do...done; while...do...done, 4723 until...do...done, ... 4724- supports environment ("global") variables (through setenv / saveenv 4725 commands) and local shell variables (through standard shell syntax 4726 "name=value"); only environment variables can be used with "run" 4727 command 4728 4729General rules: 4730-------------- 4731 4732(1) If a command line (or an environment variable executed by a "run" 4733 command) contains several commands separated by semicolon, and 4734 one of these commands fails, then the remaining commands will be 4735 executed anyway. 4736 4737(2) If you execute several variables with one call to run (i. e. 4738 calling run with a list of variables as arguments), any failing 4739 command will cause "run" to terminate, i. e. the remaining 4740 variables are not executed. 4741 4742Note for Redundant Ethernet Interfaces: 4743======================================= 4744 4745Some boards come with redundant Ethernet interfaces; U-Boot supports 4746such configurations and is capable of automatic selection of a 4747"working" interface when needed. MAC assignment works as follows: 4748 4749Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4750MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4751"eth1addr" (=>eth1), "eth2addr", ... 4752 4753If the network interface stores some valid MAC address (for instance 4754in SROM), this is used as default address if there is NO correspon- 4755ding setting in the environment; if the corresponding environment 4756variable is set, this overrides the settings in the card; that means: 4757 4758o If the SROM has a valid MAC address, and there is no address in the 4759 environment, the SROM's address is used. 4760 4761o If there is no valid address in the SROM, and a definition in the 4762 environment exists, then the value from the environment variable is 4763 used. 4764 4765o If both the SROM and the environment contain a MAC address, and 4766 both addresses are the same, this MAC address is used. 4767 4768o If both the SROM and the environment contain a MAC address, and the 4769 addresses differ, the value from the environment is used and a 4770 warning is printed. 4771 4772o If neither SROM nor the environment contain a MAC address, an error 4773 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4774 a random, locally-assigned MAC is used. 4775 4776If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4777will be programmed into hardware as part of the initialization process. This 4778may be skipped by setting the appropriate 'ethmacskip' environment variable. 4779The naming convention is as follows: 4780"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4781 4782Image Formats: 4783============== 4784 4785U-Boot is capable of booting (and performing other auxiliary operations on) 4786images in two formats: 4787 4788New uImage format (FIT) 4789----------------------- 4790 4791Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4792to Flattened Device Tree). It allows the use of images with multiple 4793components (several kernels, ramdisks, etc.), with contents protected by 4794SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4795 4796 4797Old uImage format 4798----------------- 4799 4800Old image format is based on binary files which can be basically anything, 4801preceded by a special header; see the definitions in include/image.h for 4802details; basically, the header defines the following image properties: 4803 4804* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4805 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4806 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4807 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4808 INTEGRITY). 4809* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4810 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4811 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4812* Compression Type (uncompressed, gzip, bzip2) 4813* Load Address 4814* Entry Point 4815* Image Name 4816* Image Timestamp 4817 4818The header is marked by a special Magic Number, and both the header 4819and the data portions of the image are secured against corruption by 4820CRC32 checksums. 4821 4822 4823Linux Support: 4824============== 4825 4826Although U-Boot should support any OS or standalone application 4827easily, the main focus has always been on Linux during the design of 4828U-Boot. 4829 4830U-Boot includes many features that so far have been part of some 4831special "boot loader" code within the Linux kernel. Also, any 4832"initrd" images to be used are no longer part of one big Linux image; 4833instead, kernel and "initrd" are separate images. This implementation 4834serves several purposes: 4835 4836- the same features can be used for other OS or standalone 4837 applications (for instance: using compressed images to reduce the 4838 Flash memory footprint) 4839 4840- it becomes much easier to port new Linux kernel versions because 4841 lots of low-level, hardware dependent stuff are done by U-Boot 4842 4843- the same Linux kernel image can now be used with different "initrd" 4844 images; of course this also means that different kernel images can 4845 be run with the same "initrd". This makes testing easier (you don't 4846 have to build a new "zImage.initrd" Linux image when you just 4847 change a file in your "initrd"). Also, a field-upgrade of the 4848 software is easier now. 4849 4850 4851Linux HOWTO: 4852============ 4853 4854Porting Linux to U-Boot based systems: 4855--------------------------------------- 4856 4857U-Boot cannot save you from doing all the necessary modifications to 4858configure the Linux device drivers for use with your target hardware 4859(no, we don't intend to provide a full virtual machine interface to 4860Linux :-). 4861 4862But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4863 4864Just make sure your machine specific header file (for instance 4865include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4866Information structure as we define in include/asm-<arch>/u-boot.h, 4867and make sure that your definition of IMAP_ADDR uses the same value 4868as your U-Boot configuration in CONFIG_SYS_IMMR. 4869 4870Note that U-Boot now has a driver model, a unified model for drivers. 4871If you are adding a new driver, plumb it into driver model. If there 4872is no uclass available, you are encouraged to create one. See 4873doc/driver-model. 4874 4875 4876Configuring the Linux kernel: 4877----------------------------- 4878 4879No specific requirements for U-Boot. Make sure you have some root 4880device (initial ramdisk, NFS) for your target system. 4881 4882 4883Building a Linux Image: 4884----------------------- 4885 4886With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4887not used. If you use recent kernel source, a new build target 4888"uImage" will exist which automatically builds an image usable by 4889U-Boot. Most older kernels also have support for a "pImage" target, 4890which was introduced for our predecessor project PPCBoot and uses a 4891100% compatible format. 4892 4893Example: 4894 4895 make TQM850L_defconfig 4896 make oldconfig 4897 make dep 4898 make uImage 4899 4900The "uImage" build target uses a special tool (in 'tools/mkimage') to 4901encapsulate a compressed Linux kernel image with header information, 4902CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4903 4904* build a standard "vmlinux" kernel image (in ELF binary format): 4905 4906* convert the kernel into a raw binary image: 4907 4908 ${CROSS_COMPILE}-objcopy -O binary \ 4909 -R .note -R .comment \ 4910 -S vmlinux linux.bin 4911 4912* compress the binary image: 4913 4914 gzip -9 linux.bin 4915 4916* package compressed binary image for U-Boot: 4917 4918 mkimage -A ppc -O linux -T kernel -C gzip \ 4919 -a 0 -e 0 -n "Linux Kernel Image" \ 4920 -d linux.bin.gz uImage 4921 4922 4923The "mkimage" tool can also be used to create ramdisk images for use 4924with U-Boot, either separated from the Linux kernel image, or 4925combined into one file. "mkimage" encapsulates the images with a 64 4926byte header containing information about target architecture, 4927operating system, image type, compression method, entry points, time 4928stamp, CRC32 checksums, etc. 4929 4930"mkimage" can be called in two ways: to verify existing images and 4931print the header information, or to build new images. 4932 4933In the first form (with "-l" option) mkimage lists the information 4934contained in the header of an existing U-Boot image; this includes 4935checksum verification: 4936 4937 tools/mkimage -l image 4938 -l ==> list image header information 4939 4940The second form (with "-d" option) is used to build a U-Boot image 4941from a "data file" which is used as image payload: 4942 4943 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4944 -n name -d data_file image 4945 -A ==> set architecture to 'arch' 4946 -O ==> set operating system to 'os' 4947 -T ==> set image type to 'type' 4948 -C ==> set compression type 'comp' 4949 -a ==> set load address to 'addr' (hex) 4950 -e ==> set entry point to 'ep' (hex) 4951 -n ==> set image name to 'name' 4952 -d ==> use image data from 'datafile' 4953 4954Right now, all Linux kernels for PowerPC systems use the same load 4955address (0x00000000), but the entry point address depends on the 4956kernel version: 4957 4958- 2.2.x kernels have the entry point at 0x0000000C, 4959- 2.3.x and later kernels have the entry point at 0x00000000. 4960 4961So a typical call to build a U-Boot image would read: 4962 4963 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4964 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4965 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4966 > examples/uImage.TQM850L 4967 Image Name: 2.4.4 kernel for TQM850L 4968 Created: Wed Jul 19 02:34:59 2000 4969 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4970 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4971 Load Address: 0x00000000 4972 Entry Point: 0x00000000 4973 4974To verify the contents of the image (or check for corruption): 4975 4976 -> tools/mkimage -l examples/uImage.TQM850L 4977 Image Name: 2.4.4 kernel for TQM850L 4978 Created: Wed Jul 19 02:34:59 2000 4979 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4980 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4981 Load Address: 0x00000000 4982 Entry Point: 0x00000000 4983 4984NOTE: for embedded systems where boot time is critical you can trade 4985speed for memory and install an UNCOMPRESSED image instead: this 4986needs more space in Flash, but boots much faster since it does not 4987need to be uncompressed: 4988 4989 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4990 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4991 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4992 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4993 > examples/uImage.TQM850L-uncompressed 4994 Image Name: 2.4.4 kernel for TQM850L 4995 Created: Wed Jul 19 02:34:59 2000 4996 Image Type: PowerPC Linux Kernel Image (uncompressed) 4997 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4998 Load Address: 0x00000000 4999 Entry Point: 0x00000000 5000 5001 5002Similar you can build U-Boot images from a 'ramdisk.image.gz' file 5003when your kernel is intended to use an initial ramdisk: 5004 5005 -> tools/mkimage -n 'Simple Ramdisk Image' \ 5006 > -A ppc -O linux -T ramdisk -C gzip \ 5007 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 5008 Image Name: Simple Ramdisk Image 5009 Created: Wed Jan 12 14:01:50 2000 5010 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5011 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 5012 Load Address: 0x00000000 5013 Entry Point: 0x00000000 5014 5015The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 5016option performs the converse operation of the mkimage's second form (the "-d" 5017option). Given an image built by mkimage, the dumpimage extracts a "data file" 5018from the image: 5019 5020 tools/dumpimage -i image -T type -p position data_file 5021 -i ==> extract from the 'image' a specific 'data_file' 5022 -T ==> set image type to 'type' 5023 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 5024 5025 5026Installing a Linux Image: 5027------------------------- 5028 5029To downloading a U-Boot image over the serial (console) interface, 5030you must convert the image to S-Record format: 5031 5032 objcopy -I binary -O srec examples/image examples/image.srec 5033 5034The 'objcopy' does not understand the information in the U-Boot 5035image header, so the resulting S-Record file will be relative to 5036address 0x00000000. To load it to a given address, you need to 5037specify the target address as 'offset' parameter with the 'loads' 5038command. 5039 5040Example: install the image to address 0x40100000 (which on the 5041TQM8xxL is in the first Flash bank): 5042 5043 => erase 40100000 401FFFFF 5044 5045 .......... done 5046 Erased 8 sectors 5047 5048 => loads 40100000 5049 ## Ready for S-Record download ... 5050 ~>examples/image.srec 5051 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 5052 ... 5053 15989 15990 15991 15992 5054 [file transfer complete] 5055 [connected] 5056 ## Start Addr = 0x00000000 5057 5058 5059You can check the success of the download using the 'iminfo' command; 5060this includes a checksum verification so you can be sure no data 5061corruption happened: 5062 5063 => imi 40100000 5064 5065 ## Checking Image at 40100000 ... 5066 Image Name: 2.2.13 for initrd on TQM850L 5067 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5068 Data Size: 335725 Bytes = 327 kB = 0 MB 5069 Load Address: 00000000 5070 Entry Point: 0000000c 5071 Verifying Checksum ... OK 5072 5073 5074Boot Linux: 5075----------- 5076 5077The "bootm" command is used to boot an application that is stored in 5078memory (RAM or Flash). In case of a Linux kernel image, the contents 5079of the "bootargs" environment variable is passed to the kernel as 5080parameters. You can check and modify this variable using the 5081"printenv" and "setenv" commands: 5082 5083 5084 => printenv bootargs 5085 bootargs=root=/dev/ram 5086 5087 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5088 5089 => printenv bootargs 5090 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5091 5092 => bootm 40020000 5093 ## Booting Linux kernel at 40020000 ... 5094 Image Name: 2.2.13 for NFS on TQM850L 5095 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5096 Data Size: 381681 Bytes = 372 kB = 0 MB 5097 Load Address: 00000000 5098 Entry Point: 0000000c 5099 Verifying Checksum ... OK 5100 Uncompressing Kernel Image ... OK 5101 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 5102 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 5103 time_init: decrementer frequency = 187500000/60 5104 Calibrating delay loop... 49.77 BogoMIPS 5105 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 5106 ... 5107 5108If you want to boot a Linux kernel with initial RAM disk, you pass 5109the memory addresses of both the kernel and the initrd image (PPBCOOT 5110format!) to the "bootm" command: 5111 5112 => imi 40100000 40200000 5113 5114 ## Checking Image at 40100000 ... 5115 Image Name: 2.2.13 for initrd on TQM850L 5116 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5117 Data Size: 335725 Bytes = 327 kB = 0 MB 5118 Load Address: 00000000 5119 Entry Point: 0000000c 5120 Verifying Checksum ... OK 5121 5122 ## Checking Image at 40200000 ... 5123 Image Name: Simple Ramdisk Image 5124 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5125 Data Size: 566530 Bytes = 553 kB = 0 MB 5126 Load Address: 00000000 5127 Entry Point: 00000000 5128 Verifying Checksum ... OK 5129 5130 => bootm 40100000 40200000 5131 ## Booting Linux kernel at 40100000 ... 5132 Image Name: 2.2.13 for initrd on TQM850L 5133 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5134 Data Size: 335725 Bytes = 327 kB = 0 MB 5135 Load Address: 00000000 5136 Entry Point: 0000000c 5137 Verifying Checksum ... OK 5138 Uncompressing Kernel Image ... OK 5139 ## Loading RAMDisk Image at 40200000 ... 5140 Image Name: Simple Ramdisk Image 5141 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5142 Data Size: 566530 Bytes = 553 kB = 0 MB 5143 Load Address: 00000000 5144 Entry Point: 00000000 5145 Verifying Checksum ... OK 5146 Loading Ramdisk ... OK 5147 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 5148 Boot arguments: root=/dev/ram 5149 time_init: decrementer frequency = 187500000/60 5150 Calibrating delay loop... 49.77 BogoMIPS 5151 ... 5152 RAMDISK: Compressed image found at block 0 5153 VFS: Mounted root (ext2 filesystem). 5154 5155 bash# 5156 5157Boot Linux and pass a flat device tree: 5158----------- 5159 5160First, U-Boot must be compiled with the appropriate defines. See the section 5161titled "Linux Kernel Interface" above for a more in depth explanation. The 5162following is an example of how to start a kernel and pass an updated 5163flat device tree: 5164 5165=> print oftaddr 5166oftaddr=0x300000 5167=> print oft 5168oft=oftrees/mpc8540ads.dtb 5169=> tftp $oftaddr $oft 5170Speed: 1000, full duplex 5171Using TSEC0 device 5172TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5173Filename 'oftrees/mpc8540ads.dtb'. 5174Load address: 0x300000 5175Loading: # 5176done 5177Bytes transferred = 4106 (100a hex) 5178=> tftp $loadaddr $bootfile 5179Speed: 1000, full duplex 5180Using TSEC0 device 5181TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5182Filename 'uImage'. 5183Load address: 0x200000 5184Loading:############ 5185done 5186Bytes transferred = 1029407 (fb51f hex) 5187=> print loadaddr 5188loadaddr=200000 5189=> print oftaddr 5190oftaddr=0x300000 5191=> bootm $loadaddr - $oftaddr 5192## Booting image at 00200000 ... 5193 Image Name: Linux-2.6.17-dirty 5194 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5195 Data Size: 1029343 Bytes = 1005.2 kB 5196 Load Address: 00000000 5197 Entry Point: 00000000 5198 Verifying Checksum ... OK 5199 Uncompressing Kernel Image ... OK 5200Booting using flat device tree at 0x300000 5201Using MPC85xx ADS machine description 5202Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5203[snip] 5204 5205 5206More About U-Boot Image Types: 5207------------------------------ 5208 5209U-Boot supports the following image types: 5210 5211 "Standalone Programs" are directly runnable in the environment 5212 provided by U-Boot; it is expected that (if they behave 5213 well) you can continue to work in U-Boot after return from 5214 the Standalone Program. 5215 "OS Kernel Images" are usually images of some Embedded OS which 5216 will take over control completely. Usually these programs 5217 will install their own set of exception handlers, device 5218 drivers, set up the MMU, etc. - this means, that you cannot 5219 expect to re-enter U-Boot except by resetting the CPU. 5220 "RAMDisk Images" are more or less just data blocks, and their 5221 parameters (address, size) are passed to an OS kernel that is 5222 being started. 5223 "Multi-File Images" contain several images, typically an OS 5224 (Linux) kernel image and one or more data images like 5225 RAMDisks. This construct is useful for instance when you want 5226 to boot over the network using BOOTP etc., where the boot 5227 server provides just a single image file, but you want to get 5228 for instance an OS kernel and a RAMDisk image. 5229 5230 "Multi-File Images" start with a list of image sizes, each 5231 image size (in bytes) specified by an "uint32_t" in network 5232 byte order. This list is terminated by an "(uint32_t)0". 5233 Immediately after the terminating 0 follow the images, one by 5234 one, all aligned on "uint32_t" boundaries (size rounded up to 5235 a multiple of 4 bytes). 5236 5237 "Firmware Images" are binary images containing firmware (like 5238 U-Boot or FPGA images) which usually will be programmed to 5239 flash memory. 5240 5241 "Script files" are command sequences that will be executed by 5242 U-Boot's command interpreter; this feature is especially 5243 useful when you configure U-Boot to use a real shell (hush) 5244 as command interpreter. 5245 5246Booting the Linux zImage: 5247------------------------- 5248 5249On some platforms, it's possible to boot Linux zImage. This is done 5250using the "bootz" command. The syntax of "bootz" command is the same 5251as the syntax of "bootm" command. 5252 5253Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5254kernel with raw initrd images. The syntax is slightly different, the 5255address of the initrd must be augmented by it's size, in the following 5256format: "<initrd addres>:<initrd size>". 5257 5258 5259Standalone HOWTO: 5260================= 5261 5262One of the features of U-Boot is that you can dynamically load and 5263run "standalone" applications, which can use some resources of 5264U-Boot like console I/O functions or interrupt services. 5265 5266Two simple examples are included with the sources: 5267 5268"Hello World" Demo: 5269------------------- 5270 5271'examples/hello_world.c' contains a small "Hello World" Demo 5272application; it is automatically compiled when you build U-Boot. 5273It's configured to run at address 0x00040004, so you can play with it 5274like that: 5275 5276 => loads 5277 ## Ready for S-Record download ... 5278 ~>examples/hello_world.srec 5279 1 2 3 4 5 6 7 8 9 10 11 ... 5280 [file transfer complete] 5281 [connected] 5282 ## Start Addr = 0x00040004 5283 5284 => go 40004 Hello World! This is a test. 5285 ## Starting application at 0x00040004 ... 5286 Hello World 5287 argc = 7 5288 argv[0] = "40004" 5289 argv[1] = "Hello" 5290 argv[2] = "World!" 5291 argv[3] = "This" 5292 argv[4] = "is" 5293 argv[5] = "a" 5294 argv[6] = "test." 5295 argv[7] = "<NULL>" 5296 Hit any key to exit ... 5297 5298 ## Application terminated, rc = 0x0 5299 5300Another example, which demonstrates how to register a CPM interrupt 5301handler with the U-Boot code, can be found in 'examples/timer.c'. 5302Here, a CPM timer is set up to generate an interrupt every second. 5303The interrupt service routine is trivial, just printing a '.' 5304character, but this is just a demo program. The application can be 5305controlled by the following keys: 5306 5307 ? - print current values og the CPM Timer registers 5308 b - enable interrupts and start timer 5309 e - stop timer and disable interrupts 5310 q - quit application 5311 5312 => loads 5313 ## Ready for S-Record download ... 5314 ~>examples/timer.srec 5315 1 2 3 4 5 6 7 8 9 10 11 ... 5316 [file transfer complete] 5317 [connected] 5318 ## Start Addr = 0x00040004 5319 5320 => go 40004 5321 ## Starting application at 0x00040004 ... 5322 TIMERS=0xfff00980 5323 Using timer 1 5324 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5325 5326Hit 'b': 5327 [q, b, e, ?] Set interval 1000000 us 5328 Enabling timer 5329Hit '?': 5330 [q, b, e, ?] ........ 5331 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5332Hit '?': 5333 [q, b, e, ?] . 5334 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5335Hit '?': 5336 [q, b, e, ?] . 5337 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5338Hit '?': 5339 [q, b, e, ?] . 5340 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5341Hit 'e': 5342 [q, b, e, ?] ...Stopping timer 5343Hit 'q': 5344 [q, b, e, ?] ## Application terminated, rc = 0x0 5345 5346 5347Minicom warning: 5348================ 5349 5350Over time, many people have reported problems when trying to use the 5351"minicom" terminal emulation program for serial download. I (wd) 5352consider minicom to be broken, and recommend not to use it. Under 5353Unix, I recommend to use C-Kermit for general purpose use (and 5354especially for kermit binary protocol download ("loadb" command), and 5355use "cu" for S-Record download ("loads" command). See 5356http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5357for help with kermit. 5358 5359 5360Nevertheless, if you absolutely want to use it try adding this 5361configuration to your "File transfer protocols" section: 5362 5363 Name Program Name U/D FullScr IO-Red. Multi 5364 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5365 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5366 5367 5368NetBSD Notes: 5369============= 5370 5371Starting at version 0.9.2, U-Boot supports NetBSD both as host 5372(build U-Boot) and target system (boots NetBSD/mpc8xx). 5373 5374Building requires a cross environment; it is known to work on 5375NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5376need gmake since the Makefiles are not compatible with BSD make). 5377Note that the cross-powerpc package does not install include files; 5378attempting to build U-Boot will fail because <machine/ansi.h> is 5379missing. This file has to be installed and patched manually: 5380 5381 # cd /usr/pkg/cross/powerpc-netbsd/include 5382 # mkdir powerpc 5383 # ln -s powerpc machine 5384 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5385 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5386 5387Native builds *don't* work due to incompatibilities between native 5388and U-Boot include files. 5389 5390Booting assumes that (the first part of) the image booted is a 5391stage-2 loader which in turn loads and then invokes the kernel 5392proper. Loader sources will eventually appear in the NetBSD source 5393tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5394meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5395 5396 5397Implementation Internals: 5398========================= 5399 5400The following is not intended to be a complete description of every 5401implementation detail. However, it should help to understand the 5402inner workings of U-Boot and make it easier to port it to custom 5403hardware. 5404 5405 5406Initial Stack, Global Data: 5407--------------------------- 5408 5409The implementation of U-Boot is complicated by the fact that U-Boot 5410starts running out of ROM (flash memory), usually without access to 5411system RAM (because the memory controller is not initialized yet). 5412This means that we don't have writable Data or BSS segments, and BSS 5413is not initialized as zero. To be able to get a C environment working 5414at all, we have to allocate at least a minimal stack. Implementation 5415options for this are defined and restricted by the CPU used: Some CPU 5416models provide on-chip memory (like the IMMR area on MPC8xx and 5417MPC826x processors), on others (parts of) the data cache can be 5418locked as (mis-) used as memory, etc. 5419 5420 Chris Hallinan posted a good summary of these issues to the 5421 U-Boot mailing list: 5422 5423 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5424 From: "Chris Hallinan" <clh@net1plus.com> 5425 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5426 ... 5427 5428 Correct me if I'm wrong, folks, but the way I understand it 5429 is this: Using DCACHE as initial RAM for Stack, etc, does not 5430 require any physical RAM backing up the cache. The cleverness 5431 is that the cache is being used as a temporary supply of 5432 necessary storage before the SDRAM controller is setup. It's 5433 beyond the scope of this list to explain the details, but you 5434 can see how this works by studying the cache architecture and 5435 operation in the architecture and processor-specific manuals. 5436 5437 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5438 is another option for the system designer to use as an 5439 initial stack/RAM area prior to SDRAM being available. Either 5440 option should work for you. Using CS 4 should be fine if your 5441 board designers haven't used it for something that would 5442 cause you grief during the initial boot! It is frequently not 5443 used. 5444 5445 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5446 with your processor/board/system design. The default value 5447 you will find in any recent u-boot distribution in 5448 walnut.h should work for you. I'd set it to a value larger 5449 than your SDRAM module. If you have a 64MB SDRAM module, set 5450 it above 400_0000. Just make sure your board has no resources 5451 that are supposed to respond to that address! That code in 5452 start.S has been around a while and should work as is when 5453 you get the config right. 5454 5455 -Chris Hallinan 5456 DS4.COM, Inc. 5457 5458It is essential to remember this, since it has some impact on the C 5459code for the initialization procedures: 5460 5461* Initialized global data (data segment) is read-only. Do not attempt 5462 to write it. 5463 5464* Do not use any uninitialized global data (or implicitly initialized 5465 as zero data - BSS segment) at all - this is undefined, initiali- 5466 zation is performed later (when relocating to RAM). 5467 5468* Stack space is very limited. Avoid big data buffers or things like 5469 that. 5470 5471Having only the stack as writable memory limits means we cannot use 5472normal global data to share information between the code. But it 5473turned out that the implementation of U-Boot can be greatly 5474simplified by making a global data structure (gd_t) available to all 5475functions. We could pass a pointer to this data as argument to _all_ 5476functions, but this would bloat the code. Instead we use a feature of 5477the GCC compiler (Global Register Variables) to share the data: we 5478place a pointer (gd) to the global data into a register which we 5479reserve for this purpose. 5480 5481When choosing a register for such a purpose we are restricted by the 5482relevant (E)ABI specifications for the current architecture, and by 5483GCC's implementation. 5484 5485For PowerPC, the following registers have specific use: 5486 R1: stack pointer 5487 R2: reserved for system use 5488 R3-R4: parameter passing and return values 5489 R5-R10: parameter passing 5490 R13: small data area pointer 5491 R30: GOT pointer 5492 R31: frame pointer 5493 5494 (U-Boot also uses R12 as internal GOT pointer. r12 5495 is a volatile register so r12 needs to be reset when 5496 going back and forth between asm and C) 5497 5498 ==> U-Boot will use R2 to hold a pointer to the global data 5499 5500 Note: on PPC, we could use a static initializer (since the 5501 address of the global data structure is known at compile time), 5502 but it turned out that reserving a register results in somewhat 5503 smaller code - although the code savings are not that big (on 5504 average for all boards 752 bytes for the whole U-Boot image, 5505 624 text + 127 data). 5506 5507On ARM, the following registers are used: 5508 5509 R0: function argument word/integer result 5510 R1-R3: function argument word 5511 R9: platform specific 5512 R10: stack limit (used only if stack checking is enabled) 5513 R11: argument (frame) pointer 5514 R12: temporary workspace 5515 R13: stack pointer 5516 R14: link register 5517 R15: program counter 5518 5519 ==> U-Boot will use R9 to hold a pointer to the global data 5520 5521 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5522 5523On Nios II, the ABI is documented here: 5524 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5525 5526 ==> U-Boot will use gp to hold a pointer to the global data 5527 5528 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5529 to access small data sections, so gp is free. 5530 5531On NDS32, the following registers are used: 5532 5533 R0-R1: argument/return 5534 R2-R5: argument 5535 R15: temporary register for assembler 5536 R16: trampoline register 5537 R28: frame pointer (FP) 5538 R29: global pointer (GP) 5539 R30: link register (LP) 5540 R31: stack pointer (SP) 5541 PC: program counter (PC) 5542 5543 ==> U-Boot will use R10 to hold a pointer to the global data 5544 5545NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5546or current versions of GCC may "optimize" the code too much. 5547 5548Memory Management: 5549------------------ 5550 5551U-Boot runs in system state and uses physical addresses, i.e. the 5552MMU is not used either for address mapping nor for memory protection. 5553 5554The available memory is mapped to fixed addresses using the memory 5555controller. In this process, a contiguous block is formed for each 5556memory type (Flash, SDRAM, SRAM), even when it consists of several 5557physical memory banks. 5558 5559U-Boot is installed in the first 128 kB of the first Flash bank (on 5560TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5561booting and sizing and initializing DRAM, the code relocates itself 5562to the upper end of DRAM. Immediately below the U-Boot code some 5563memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5564configuration setting]. Below that, a structure with global Board 5565Info data is placed, followed by the stack (growing downward). 5566 5567Additionally, some exception handler code is copied to the low 8 kB 5568of DRAM (0x00000000 ... 0x00001FFF). 5569 5570So a typical memory configuration with 16 MB of DRAM could look like 5571this: 5572 5573 0x0000 0000 Exception Vector code 5574 : 5575 0x0000 1FFF 5576 0x0000 2000 Free for Application Use 5577 : 5578 : 5579 5580 : 5581 : 5582 0x00FB FF20 Monitor Stack (Growing downward) 5583 0x00FB FFAC Board Info Data and permanent copy of global data 5584 0x00FC 0000 Malloc Arena 5585 : 5586 0x00FD FFFF 5587 0x00FE 0000 RAM Copy of Monitor Code 5588 ... eventually: LCD or video framebuffer 5589 ... eventually: pRAM (Protected RAM - unchanged by reset) 5590 0x00FF FFFF [End of RAM] 5591 5592 5593System Initialization: 5594---------------------- 5595 5596In the reset configuration, U-Boot starts at the reset entry point 5597(on most PowerPC systems at address 0x00000100). Because of the reset 5598configuration for CS0# this is a mirror of the on board Flash memory. 5599To be able to re-map memory U-Boot then jumps to its link address. 5600To be able to implement the initialization code in C, a (small!) 5601initial stack is set up in the internal Dual Ported RAM (in case CPUs 5602which provide such a feature like), or in a locked part of the data 5603cache. After that, U-Boot initializes the CPU core, the caches and 5604the SIU. 5605 5606Next, all (potentially) available memory banks are mapped using a 5607preliminary mapping. For example, we put them on 512 MB boundaries 5608(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5609on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5610programmed for SDRAM access. Using the temporary configuration, a 5611simple memory test is run that determines the size of the SDRAM 5612banks. 5613 5614When there is more than one SDRAM bank, and the banks are of 5615different size, the largest is mapped first. For equal size, the first 5616bank (CS2#) is mapped first. The first mapping is always for address 56170x00000000, with any additional banks following immediately to create 5618contiguous memory starting from 0. 5619 5620Then, the monitor installs itself at the upper end of the SDRAM area 5621and allocates memory for use by malloc() and for the global Board 5622Info data; also, the exception vector code is copied to the low RAM 5623pages, and the final stack is set up. 5624 5625Only after this relocation will you have a "normal" C environment; 5626until that you are restricted in several ways, mostly because you are 5627running from ROM, and because the code will have to be relocated to a 5628new address in RAM. 5629 5630 5631U-Boot Porting Guide: 5632---------------------- 5633 5634[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5635list, October 2002] 5636 5637 5638int main(int argc, char *argv[]) 5639{ 5640 sighandler_t no_more_time; 5641 5642 signal(SIGALRM, no_more_time); 5643 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5644 5645 if (available_money > available_manpower) { 5646 Pay consultant to port U-Boot; 5647 return 0; 5648 } 5649 5650 Download latest U-Boot source; 5651 5652 Subscribe to u-boot mailing list; 5653 5654 if (clueless) 5655 email("Hi, I am new to U-Boot, how do I get started?"); 5656 5657 while (learning) { 5658 Read the README file in the top level directory; 5659 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5660 Read applicable doc/*.README; 5661 Read the source, Luke; 5662 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5663 } 5664 5665 if (available_money > toLocalCurrency ($2500)) 5666 Buy a BDI3000; 5667 else 5668 Add a lot of aggravation and time; 5669 5670 if (a similar board exists) { /* hopefully... */ 5671 cp -a board/<similar> board/<myboard> 5672 cp include/configs/<similar>.h include/configs/<myboard>.h 5673 } else { 5674 Create your own board support subdirectory; 5675 Create your own board include/configs/<myboard>.h file; 5676 } 5677 Edit new board/<myboard> files 5678 Edit new include/configs/<myboard>.h 5679 5680 while (!accepted) { 5681 while (!running) { 5682 do { 5683 Add / modify source code; 5684 } until (compiles); 5685 Debug; 5686 if (clueless) 5687 email("Hi, I am having problems..."); 5688 } 5689 Send patch file to the U-Boot email list; 5690 if (reasonable critiques) 5691 Incorporate improvements from email list code review; 5692 else 5693 Defend code as written; 5694 } 5695 5696 return 0; 5697} 5698 5699void no_more_time (int sig) 5700{ 5701 hire_a_guru(); 5702} 5703 5704 5705Coding Standards: 5706----------------- 5707 5708All contributions to U-Boot should conform to the Linux kernel 5709coding style; see the file "Documentation/CodingStyle" and the script 5710"scripts/Lindent" in your Linux kernel source directory. 5711 5712Source files originating from a different project (for example the 5713MTD subsystem) are generally exempt from these guidelines and are not 5714reformatted to ease subsequent migration to newer versions of those 5715sources. 5716 5717Please note that U-Boot is implemented in C (and to some small parts in 5718Assembler); no C++ is used, so please do not use C++ style comments (//) 5719in your code. 5720 5721Please also stick to the following formatting rules: 5722- remove any trailing white space 5723- use TAB characters for indentation and vertical alignment, not spaces 5724- make sure NOT to use DOS '\r\n' line feeds 5725- do not add more than 2 consecutive empty lines to source files 5726- do not add trailing empty lines to source files 5727 5728Submissions which do not conform to the standards may be returned 5729with a request to reformat the changes. 5730 5731 5732Submitting Patches: 5733------------------- 5734 5735Since the number of patches for U-Boot is growing, we need to 5736establish some rules. Submissions which do not conform to these rules 5737may be rejected, even when they contain important and valuable stuff. 5738 5739Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5740 5741Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5742see http://lists.denx.de/mailman/listinfo/u-boot 5743 5744When you send a patch, please include the following information with 5745it: 5746 5747* For bug fixes: a description of the bug and how your patch fixes 5748 this bug. Please try to include a way of demonstrating that the 5749 patch actually fixes something. 5750 5751* For new features: a description of the feature and your 5752 implementation. 5753 5754* A CHANGELOG entry as plaintext (separate from the patch) 5755 5756* For major contributions, add a MAINTAINERS file with your 5757 information and associated file and directory references. 5758 5759* When you add support for a new board, don't forget to add a 5760 maintainer e-mail address to the boards.cfg file, too. 5761 5762* If your patch adds new configuration options, don't forget to 5763 document these in the README file. 5764 5765* The patch itself. If you are using git (which is *strongly* 5766 recommended) you can easily generate the patch using the 5767 "git format-patch". If you then use "git send-email" to send it to 5768 the U-Boot mailing list, you will avoid most of the common problems 5769 with some other mail clients. 5770 5771 If you cannot use git, use "diff -purN OLD NEW". If your version of 5772 diff does not support these options, then get the latest version of 5773 GNU diff. 5774 5775 The current directory when running this command shall be the parent 5776 directory of the U-Boot source tree (i. e. please make sure that 5777 your patch includes sufficient directory information for the 5778 affected files). 5779 5780 We prefer patches as plain text. MIME attachments are discouraged, 5781 and compressed attachments must not be used. 5782 5783* If one logical set of modifications affects or creates several 5784 files, all these changes shall be submitted in a SINGLE patch file. 5785 5786* Changesets that contain different, unrelated modifications shall be 5787 submitted as SEPARATE patches, one patch per changeset. 5788 5789 5790Notes: 5791 5792* Before sending the patch, run the buildman script on your patched 5793 source tree and make sure that no errors or warnings are reported 5794 for any of the boards. 5795 5796* Keep your modifications to the necessary minimum: A patch 5797 containing several unrelated changes or arbitrary reformats will be 5798 returned with a request to re-formatting / split it. 5799 5800* If you modify existing code, make sure that your new code does not 5801 add to the memory footprint of the code ;-) Small is beautiful! 5802 When adding new features, these should compile conditionally only 5803 (using #ifdef), and the resulting code with the new feature 5804 disabled must not need more memory than the old code without your 5805 modification. 5806 5807* Remember that there is a size limit of 100 kB per message on the 5808 u-boot mailing list. Bigger patches will be moderated. If they are 5809 reasonable and not too big, they will be acknowledged. But patches 5810 bigger than the size limit should be avoided. 5811