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_NAND * NAND support 814 CONFIG_CMD_NET bootp, tftpboot, rarpboot 815 CONFIG_CMD_NFS NFS support 816 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands 817 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command 818 CONFIG_CMD_PCI * pciinfo 819 CONFIG_CMD_PCMCIA * PCMCIA support 820 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network 821 host 822 CONFIG_CMD_PORTIO * Port I/O 823 CONFIG_CMD_READ * Read raw data from partition 824 CONFIG_CMD_REGINFO * Register dump 825 CONFIG_CMD_RUN run command in env variable 826 CONFIG_CMD_SANDBOX * sb command to access sandbox features 827 CONFIG_CMD_SAVES * save S record dump 828 CONFIG_CMD_SDRAM * print SDRAM configuration information 829 (requires CONFIG_CMD_I2C) 830 CONFIG_CMD_SF * Read/write/erase SPI NOR flash 831 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x 832 CONFIG_CMD_SOURCE "source" command Support 833 CONFIG_CMD_SPI * SPI serial bus support 834 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode 835 CONFIG_CMD_TFTPPUT * TFTP put command (upload) 836 CONFIG_CMD_TIME * run command and report execution time (ARM specific) 837 CONFIG_CMD_TIMER * access to the system tick timer 838 CONFIG_CMD_USB * USB support 839 CONFIG_CMD_CDP * Cisco Discover Protocol support 840 CONFIG_CMD_MFSL * Microblaze FSL support 841 CONFIG_CMD_XIMG Load part of Multi Image 842 CONFIG_CMD_UUID * Generate random UUID or GUID string 843 844 EXAMPLE: If you want all functions except of network 845 support you can write: 846 847 #include "config_cmd_all.h" 848 #undef CONFIG_CMD_NET 849 850 Other Commands: 851 fdt (flattened device tree) command: CONFIG_OF_LIBFDT 852 853 Note: Don't enable the "icache" and "dcache" commands 854 (configuration option CONFIG_CMD_CACHE) unless you know 855 what you (and your U-Boot users) are doing. Data 856 cache cannot be enabled on systems like the 857 8xx (where accesses to the IMMR region must be 858 uncached), and it cannot be disabled on all other 859 systems where we (mis-) use the data cache to hold an 860 initial stack and some data. 861 862 863 XXX - this list needs to get updated! 864 865- Removal of commands 866 If no commands are needed to boot, you can disable 867 CONFIG_CMDLINE to remove them. In this case, the command line 868 will not be available, and when U-Boot wants to execute the 869 boot command (on start-up) it will call board_run_command() 870 instead. This can reduce image size significantly for very 871 simple boot procedures. 872 873- Regular expression support: 874 CONFIG_REGEX 875 If this variable is defined, U-Boot is linked against 876 the SLRE (Super Light Regular Expression) library, 877 which adds regex support to some commands, as for 878 example "env grep" and "setexpr". 879 880- Device tree: 881 CONFIG_OF_CONTROL 882 If this variable is defined, U-Boot will use a device tree 883 to configure its devices, instead of relying on statically 884 compiled #defines in the board file. This option is 885 experimental and only available on a few boards. The device 886 tree is available in the global data as gd->fdt_blob. 887 888 U-Boot needs to get its device tree from somewhere. This can 889 be done using one of the three options below: 890 891 CONFIG_OF_EMBED 892 If this variable is defined, U-Boot will embed a device tree 893 binary in its image. This device tree file should be in the 894 board directory and called <soc>-<board>.dts. The binary file 895 is then picked up in board_init_f() and made available through 896 the global data structure as gd->blob. 897 898 CONFIG_OF_SEPARATE 899 If this variable is defined, U-Boot will build a device tree 900 binary. It will be called u-boot.dtb. Architecture-specific 901 code will locate it at run-time. Generally this works by: 902 903 cat u-boot.bin u-boot.dtb >image.bin 904 905 and in fact, U-Boot does this for you, creating a file called 906 u-boot-dtb.bin which is useful in the common case. You can 907 still use the individual files if you need something more 908 exotic. 909 910 CONFIG_OF_BOARD 911 If this variable is defined, U-Boot will use the device tree 912 provided by the board at runtime instead of embedding one with 913 the image. Only boards defining board_fdt_blob_setup() support 914 this option (see include/fdtdec.h file). 915 916- Watchdog: 917 CONFIG_WATCHDOG 918 If this variable is defined, it enables watchdog 919 support for the SoC. There must be support in the SoC 920 specific code for a watchdog. For the 8xx 921 CPUs, the SIU Watchdog feature is enabled in the SYPCR 922 register. When supported for a specific SoC is 923 available, then no further board specific code should 924 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 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 1045 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 1046 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 1047 maximum numbers of LUNs, SCSI ID's and target 1048 devices. 1049 1050 The environment variable 'scsidevs' is set to the number of 1051 SCSI devices found during the last scan. 1052 1053- NETWORK Support (PCI): 1054 CONFIG_E1000 1055 Support for Intel 8254x/8257x gigabit chips. 1056 1057 CONFIG_E1000_SPI 1058 Utility code for direct access to the SPI bus on Intel 8257x. 1059 This does not do anything useful unless you set at least one 1060 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 1061 1062 CONFIG_E1000_SPI_GENERIC 1063 Allow generic access to the SPI bus on the Intel 8257x, for 1064 example with the "sspi" command. 1065 1066 CONFIG_CMD_E1000 1067 Management command for E1000 devices. When used on devices 1068 with SPI support you can reprogram the EEPROM from U-Boot. 1069 1070 CONFIG_EEPRO100 1071 Support for Intel 82557/82559/82559ER chips. 1072 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 1073 write routine for first time initialisation. 1074 1075 CONFIG_TULIP 1076 Support for Digital 2114x chips. 1077 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 1078 modem chip initialisation (KS8761/QS6611). 1079 1080 CONFIG_NATSEMI 1081 Support for National dp83815 chips. 1082 1083 CONFIG_NS8382X 1084 Support for National dp8382[01] gigabit chips. 1085 1086- NETWORK Support (other): 1087 1088 CONFIG_DRIVER_AT91EMAC 1089 Support for AT91RM9200 EMAC. 1090 1091 CONFIG_RMII 1092 Define this to use reduced MII inteface 1093 1094 CONFIG_DRIVER_AT91EMAC_QUIET 1095 If this defined, the driver is quiet. 1096 The driver doen't show link status messages. 1097 1098 CONFIG_CALXEDA_XGMAC 1099 Support for the Calxeda XGMAC device 1100 1101 CONFIG_LAN91C96 1102 Support for SMSC's LAN91C96 chips. 1103 1104 CONFIG_LAN91C96_USE_32_BIT 1105 Define this to enable 32 bit addressing 1106 1107 CONFIG_SMC91111 1108 Support for SMSC's LAN91C111 chip 1109 1110 CONFIG_SMC91111_BASE 1111 Define this to hold the physical address 1112 of the device (I/O space) 1113 1114 CONFIG_SMC_USE_32_BIT 1115 Define this if data bus is 32 bits 1116 1117 CONFIG_SMC_USE_IOFUNCS 1118 Define this to use i/o functions instead of macros 1119 (some hardware wont work with macros) 1120 1121 CONFIG_DRIVER_TI_EMAC 1122 Support for davinci emac 1123 1124 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1125 Define this if you have more then 3 PHYs. 1126 1127 CONFIG_FTGMAC100 1128 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1129 1130 CONFIG_FTGMAC100_EGIGA 1131 Define this to use GE link update with gigabit PHY. 1132 Define this if FTGMAC100 is connected to gigabit PHY. 1133 If your system has 10/100 PHY only, it might not occur 1134 wrong behavior. Because PHY usually return timeout or 1135 useless data when polling gigabit status and gigabit 1136 control registers. This behavior won't affect the 1137 correctnessof 10/100 link speed update. 1138 1139 CONFIG_SMC911X 1140 Support for SMSC's LAN911x and LAN921x chips 1141 1142 CONFIG_SMC911X_BASE 1143 Define this to hold the physical address 1144 of the device (I/O space) 1145 1146 CONFIG_SMC911X_32_BIT 1147 Define this if data bus is 32 bits 1148 1149 CONFIG_SMC911X_16_BIT 1150 Define this if data bus is 16 bits. If your processor 1151 automatically converts one 32 bit word to two 16 bit 1152 words you may also try CONFIG_SMC911X_32_BIT. 1153 1154 CONFIG_SH_ETHER 1155 Support for Renesas on-chip Ethernet controller 1156 1157 CONFIG_SH_ETHER_USE_PORT 1158 Define the number of ports to be used 1159 1160 CONFIG_SH_ETHER_PHY_ADDR 1161 Define the ETH PHY's address 1162 1163 CONFIG_SH_ETHER_CACHE_WRITEBACK 1164 If this option is set, the driver enables cache flush. 1165 1166- PWM Support: 1167 CONFIG_PWM_IMX 1168 Support for PWM module on the imx6. 1169 1170- TPM Support: 1171 CONFIG_TPM 1172 Support TPM devices. 1173 1174 CONFIG_TPM_TIS_INFINEON 1175 Support for Infineon i2c bus TPM devices. Only one device 1176 per system is supported at this time. 1177 1178 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1179 Define the burst count bytes upper limit 1180 1181 CONFIG_TPM_ST33ZP24 1182 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1183 1184 CONFIG_TPM_ST33ZP24_I2C 1185 Support for STMicroelectronics ST33ZP24 I2C devices. 1186 Requires TPM_ST33ZP24 and I2C. 1187 1188 CONFIG_TPM_ST33ZP24_SPI 1189 Support for STMicroelectronics ST33ZP24 SPI devices. 1190 Requires TPM_ST33ZP24 and SPI. 1191 1192 CONFIG_TPM_ATMEL_TWI 1193 Support for Atmel TWI TPM device. Requires I2C support. 1194 1195 CONFIG_TPM_TIS_LPC 1196 Support for generic parallel port TPM devices. Only one device 1197 per system is supported at this time. 1198 1199 CONFIG_TPM_TIS_BASE_ADDRESS 1200 Base address where the generic TPM device is mapped 1201 to. Contemporary x86 systems usually map it at 1202 0xfed40000. 1203 1204 CONFIG_CMD_TPM 1205 Add tpm monitor functions. 1206 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also 1207 provides monitor access to authorized functions. 1208 1209 CONFIG_TPM 1210 Define this to enable the TPM support library which provides 1211 functional interfaces to some TPM commands. 1212 Requires support for a TPM device. 1213 1214 CONFIG_TPM_AUTH_SESSIONS 1215 Define this to enable authorized functions in the TPM library. 1216 Requires CONFIG_TPM and CONFIG_SHA1. 1217 1218- USB Support: 1219 At the moment only the UHCI host controller is 1220 supported (PIP405, MIP405); define 1221 CONFIG_USB_UHCI to enable it. 1222 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1223 and define CONFIG_USB_STORAGE to enable the USB 1224 storage devices. 1225 Note: 1226 Supported are USB Keyboards and USB Floppy drives 1227 (TEAC FD-05PUB). 1228 1229 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1230 txfilltuning field in the EHCI controller on reset. 1231 1232 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1233 HW module registers. 1234 1235- USB Device: 1236 Define the below if you wish to use the USB console. 1237 Once firmware is rebuilt from a serial console issue the 1238 command "setenv stdin usbtty; setenv stdout usbtty" and 1239 attach your USB cable. The Unix command "dmesg" should print 1240 it has found a new device. The environment variable usbtty 1241 can be set to gserial or cdc_acm to enable your device to 1242 appear to a USB host as a Linux gserial device or a 1243 Common Device Class Abstract Control Model serial device. 1244 If you select usbtty = gserial you should be able to enumerate 1245 a Linux host by 1246 # modprobe usbserial vendor=0xVendorID product=0xProductID 1247 else if using cdc_acm, simply setting the environment 1248 variable usbtty to be cdc_acm should suffice. The following 1249 might be defined in YourBoardName.h 1250 1251 CONFIG_USB_DEVICE 1252 Define this to build a UDC device 1253 1254 CONFIG_USB_TTY 1255 Define this to have a tty type of device available to 1256 talk to the UDC device 1257 1258 CONFIG_USBD_HS 1259 Define this to enable the high speed support for usb 1260 device and usbtty. If this feature is enabled, a routine 1261 int is_usbd_high_speed(void) 1262 also needs to be defined by the driver to dynamically poll 1263 whether the enumeration has succeded at high speed or full 1264 speed. 1265 1266 CONFIG_SYS_CONSOLE_IS_IN_ENV 1267 Define this if you want stdin, stdout &/or stderr to 1268 be set to usbtty. 1269 1270 If you have a USB-IF assigned VendorID then you may wish to 1271 define your own vendor specific values either in BoardName.h 1272 or directly in usbd_vendor_info.h. If you don't define 1273 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1274 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1275 should pretend to be a Linux device to it's target host. 1276 1277 CONFIG_USBD_MANUFACTURER 1278 Define this string as the name of your company for 1279 - CONFIG_USBD_MANUFACTURER "my company" 1280 1281 CONFIG_USBD_PRODUCT_NAME 1282 Define this string as the name of your product 1283 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1284 1285 CONFIG_USBD_VENDORID 1286 Define this as your assigned Vendor ID from the USB 1287 Implementors Forum. This *must* be a genuine Vendor ID 1288 to avoid polluting the USB namespace. 1289 - CONFIG_USBD_VENDORID 0xFFFF 1290 1291 CONFIG_USBD_PRODUCTID 1292 Define this as the unique Product ID 1293 for your device 1294 - CONFIG_USBD_PRODUCTID 0xFFFF 1295 1296- ULPI Layer Support: 1297 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1298 the generic ULPI layer. The generic layer accesses the ULPI PHY 1299 via the platform viewport, so you need both the genric layer and 1300 the viewport enabled. Currently only Chipidea/ARC based 1301 viewport is supported. 1302 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1303 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1304 If your ULPI phy needs a different reference clock than the 1305 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1306 the appropriate value in Hz. 1307 1308- MMC Support: 1309 The MMC controller on the Intel PXA is supported. To 1310 enable this define CONFIG_MMC. The MMC can be 1311 accessed from the boot prompt by mapping the device 1312 to physical memory similar to flash. Command line is 1313 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1314 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1315 1316 CONFIG_SH_MMCIF 1317 Support for Renesas on-chip MMCIF controller 1318 1319 CONFIG_SH_MMCIF_ADDR 1320 Define the base address of MMCIF registers 1321 1322 CONFIG_SH_MMCIF_CLK 1323 Define the clock frequency for MMCIF 1324 1325 CONFIG_SUPPORT_EMMC_BOOT 1326 Enable some additional features of the eMMC boot partitions. 1327 1328 CONFIG_SUPPORT_EMMC_RPMB 1329 Enable the commands for reading, writing and programming the 1330 key for the Replay Protection Memory Block partition in eMMC. 1331 1332- USB Device Firmware Update (DFU) class support: 1333 CONFIG_USB_FUNCTION_DFU 1334 This enables the USB portion of the DFU USB class 1335 1336 CONFIG_CMD_DFU 1337 This enables the command "dfu" which is used to have 1338 U-Boot create a DFU class device via USB. This command 1339 requires that the "dfu_alt_info" environment variable be 1340 set and define the alt settings to expose to the host. 1341 1342 CONFIG_DFU_MMC 1343 This enables support for exposing (e)MMC devices via DFU. 1344 1345 CONFIG_DFU_NAND 1346 This enables support for exposing NAND devices via DFU. 1347 1348 CONFIG_DFU_RAM 1349 This enables support for exposing RAM via DFU. 1350 Note: DFU spec refer to non-volatile memory usage, but 1351 allow usages beyond the scope of spec - here RAM usage, 1352 one that would help mostly the developer. 1353 1354 CONFIG_SYS_DFU_DATA_BUF_SIZE 1355 Dfu transfer uses a buffer before writing data to the 1356 raw storage device. Make the size (in bytes) of this buffer 1357 configurable. The size of this buffer is also configurable 1358 through the "dfu_bufsiz" environment variable. 1359 1360 CONFIG_SYS_DFU_MAX_FILE_SIZE 1361 When updating files rather than the raw storage device, 1362 we use a static buffer to copy the file into and then write 1363 the buffer once we've been given the whole file. Define 1364 this to the maximum filesize (in bytes) for the buffer. 1365 Default is 4 MiB if undefined. 1366 1367 DFU_DEFAULT_POLL_TIMEOUT 1368 Poll timeout [ms], is the timeout a device can send to the 1369 host. The host must wait for this timeout before sending 1370 a subsequent DFU_GET_STATUS request to the device. 1371 1372 DFU_MANIFEST_POLL_TIMEOUT 1373 Poll timeout [ms], which the device sends to the host when 1374 entering dfuMANIFEST state. Host waits this timeout, before 1375 sending again an USB request to the device. 1376 1377- USB Device Android Fastboot support: 1378 CONFIG_USB_FUNCTION_FASTBOOT 1379 This enables the USB part of the fastboot gadget 1380 1381 CONFIG_CMD_FASTBOOT 1382 This enables the command "fastboot" which enables the Android 1383 fastboot mode for the platform's USB device. Fastboot is a USB 1384 protocol for downloading images, flashing and device control 1385 used on Android devices. 1386 See doc/README.android-fastboot for more information. 1387 1388 CONFIG_ANDROID_BOOT_IMAGE 1389 This enables support for booting images which use the Android 1390 image format header. 1391 1392 CONFIG_FASTBOOT_BUF_ADDR 1393 The fastboot protocol requires a large memory buffer for 1394 downloads. Define this to the starting RAM address to use for 1395 downloaded images. 1396 1397 CONFIG_FASTBOOT_BUF_SIZE 1398 The fastboot protocol requires a large memory buffer for 1399 downloads. This buffer should be as large as possible for a 1400 platform. Define this to the size available RAM for fastboot. 1401 1402 CONFIG_FASTBOOT_FLASH 1403 The fastboot protocol includes a "flash" command for writing 1404 the downloaded image to a non-volatile storage device. Define 1405 this to enable the "fastboot flash" command. 1406 1407 CONFIG_FASTBOOT_FLASH_MMC_DEV 1408 The fastboot "flash" command requires additional information 1409 regarding the non-volatile storage device. Define this to 1410 the eMMC device that fastboot should use to store the image. 1411 1412 CONFIG_FASTBOOT_GPT_NAME 1413 The fastboot "flash" command supports writing the downloaded 1414 image to the Protective MBR and the Primary GUID Partition 1415 Table. (Additionally, this downloaded image is post-processed 1416 to generate and write the Backup GUID Partition Table.) 1417 This occurs when the specified "partition name" on the 1418 "fastboot flash" command line matches this value. 1419 The default is "gpt" if undefined. 1420 1421 CONFIG_FASTBOOT_MBR_NAME 1422 The fastboot "flash" command supports writing the downloaded 1423 image to DOS MBR. 1424 This occurs when the "partition name" specified on the 1425 "fastboot flash" command line matches this value. 1426 If not defined the default value "mbr" is used. 1427 1428- Journaling Flash filesystem support: 1429 CONFIG_JFFS2_NAND 1430 Define these for a default partition on a NAND device 1431 1432 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1433 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1434 Define these for a default partition on a NOR device 1435 1436- Keyboard Support: 1437 See Kconfig help for available keyboard drivers. 1438 1439 CONFIG_KEYBOARD 1440 1441 Define this to enable a custom keyboard support. 1442 This simply calls drv_keyboard_init() which must be 1443 defined in your board-specific files. This option is deprecated 1444 and is only used by novena. For new boards, use driver model 1445 instead. 1446 1447- Video support: 1448 CONFIG_FSL_DIU_FB 1449 Enable the Freescale DIU video driver. Reference boards for 1450 SOCs that have a DIU should define this macro to enable DIU 1451 support, and should also define these other macros: 1452 1453 CONFIG_SYS_DIU_ADDR 1454 CONFIG_VIDEO 1455 CONFIG_CFB_CONSOLE 1456 CONFIG_VIDEO_SW_CURSOR 1457 CONFIG_VGA_AS_SINGLE_DEVICE 1458 CONFIG_VIDEO_LOGO 1459 CONFIG_VIDEO_BMP_LOGO 1460 1461 The DIU driver will look for the 'video-mode' environment 1462 variable, and if defined, enable the DIU as a console during 1463 boot. See the documentation file doc/README.video for a 1464 description of this variable. 1465 1466- LCD Support: CONFIG_LCD 1467 1468 Define this to enable LCD support (for output to LCD 1469 display); also select one of the supported displays 1470 by defining one of these: 1471 1472 CONFIG_ATMEL_LCD: 1473 1474 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1475 1476 CONFIG_NEC_NL6448AC33: 1477 1478 NEC NL6448AC33-18. Active, color, single scan. 1479 1480 CONFIG_NEC_NL6448BC20 1481 1482 NEC NL6448BC20-08. 6.5", 640x480. 1483 Active, color, single scan. 1484 1485 CONFIG_NEC_NL6448BC33_54 1486 1487 NEC NL6448BC33-54. 10.4", 640x480. 1488 Active, color, single scan. 1489 1490 CONFIG_SHARP_16x9 1491 1492 Sharp 320x240. Active, color, single scan. 1493 It isn't 16x9, and I am not sure what it is. 1494 1495 CONFIG_SHARP_LQ64D341 1496 1497 Sharp LQ64D341 display, 640x480. 1498 Active, color, single scan. 1499 1500 CONFIG_HLD1045 1501 1502 HLD1045 display, 640x480. 1503 Active, color, single scan. 1504 1505 CONFIG_OPTREX_BW 1506 1507 Optrex CBL50840-2 NF-FW 99 22 M5 1508 or 1509 Hitachi LMG6912RPFC-00T 1510 or 1511 Hitachi SP14Q002 1512 1513 320x240. Black & white. 1514 1515 CONFIG_LCD_ALIGNMENT 1516 1517 Normally the LCD is page-aligned (typically 4KB). If this is 1518 defined then the LCD will be aligned to this value instead. 1519 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1520 here, since it is cheaper to change data cache settings on 1521 a per-section basis. 1522 1523 1524 CONFIG_LCD_ROTATION 1525 1526 Sometimes, for example if the display is mounted in portrait 1527 mode or even if it's mounted landscape but rotated by 180degree, 1528 we need to rotate our content of the display relative to the 1529 framebuffer, so that user can read the messages which are 1530 printed out. 1531 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1532 initialized with a given rotation from "vl_rot" out of 1533 "vidinfo_t" which is provided by the board specific code. 1534 The value for vl_rot is coded as following (matching to 1535 fbcon=rotate:<n> linux-kernel commandline): 1536 0 = no rotation respectively 0 degree 1537 1 = 90 degree rotation 1538 2 = 180 degree rotation 1539 3 = 270 degree rotation 1540 1541 If CONFIG_LCD_ROTATION is not defined, the console will be 1542 initialized with 0degree rotation. 1543 1544 CONFIG_LCD_BMP_RLE8 1545 1546 Support drawing of RLE8-compressed bitmaps on the LCD. 1547 1548 CONFIG_I2C_EDID 1549 1550 Enables an 'i2c edid' command which can read EDID 1551 information over I2C from an attached LCD display. 1552 1553- Splash Screen Support: CONFIG_SPLASH_SCREEN 1554 1555 If this option is set, the environment is checked for 1556 a variable "splashimage". If found, the usual display 1557 of logo, copyright and system information on the LCD 1558 is suppressed and the BMP image at the address 1559 specified in "splashimage" is loaded instead. The 1560 console is redirected to the "nulldev", too. This 1561 allows for a "silent" boot where a splash screen is 1562 loaded very quickly after power-on. 1563 1564 CONFIG_SPLASHIMAGE_GUARD 1565 1566 If this option is set, then U-Boot will prevent the environment 1567 variable "splashimage" from being set to a problematic address 1568 (see doc/README.displaying-bmps). 1569 This option is useful for targets where, due to alignment 1570 restrictions, an improperly aligned BMP image will cause a data 1571 abort. If you think you will not have problems with unaligned 1572 accesses (for example because your toolchain prevents them) 1573 there is no need to set this option. 1574 1575 CONFIG_SPLASH_SCREEN_ALIGN 1576 1577 If this option is set the splash image can be freely positioned 1578 on the screen. Environment variable "splashpos" specifies the 1579 position as "x,y". If a positive number is given it is used as 1580 number of pixel from left/top. If a negative number is given it 1581 is used as number of pixel from right/bottom. You can also 1582 specify 'm' for centering the image. 1583 1584 Example: 1585 setenv splashpos m,m 1586 => image at center of screen 1587 1588 setenv splashpos 30,20 1589 => image at x = 30 and y = 20 1590 1591 setenv splashpos -10,m 1592 => vertically centered image 1593 at x = dspWidth - bmpWidth - 9 1594 1595- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1596 1597 If this option is set, additionally to standard BMP 1598 images, gzipped BMP images can be displayed via the 1599 splashscreen support or the bmp command. 1600 1601- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1602 1603 If this option is set, 8-bit RLE compressed BMP images 1604 can be displayed via the splashscreen support or the 1605 bmp command. 1606 1607- Compression support: 1608 CONFIG_GZIP 1609 1610 Enabled by default to support gzip compressed images. 1611 1612 CONFIG_BZIP2 1613 1614 If this option is set, support for bzip2 compressed 1615 images is included. If not, only uncompressed and gzip 1616 compressed images are supported. 1617 1618 NOTE: the bzip2 algorithm requires a lot of RAM, so 1619 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1620 be at least 4MB. 1621 1622- MII/PHY support: 1623 CONFIG_PHY_ADDR 1624 1625 The address of PHY on MII bus. 1626 1627 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1628 1629 The clock frequency of the MII bus 1630 1631 CONFIG_PHY_GIGE 1632 1633 If this option is set, support for speed/duplex 1634 detection of gigabit PHY is included. 1635 1636 CONFIG_PHY_RESET_DELAY 1637 1638 Some PHY like Intel LXT971A need extra delay after 1639 reset before any MII register access is possible. 1640 For such PHY, set this option to the usec delay 1641 required. (minimum 300usec for LXT971A) 1642 1643 CONFIG_PHY_CMD_DELAY (ppc4xx) 1644 1645 Some PHY like Intel LXT971A need extra delay after 1646 command issued before MII status register can be read 1647 1648- IP address: 1649 CONFIG_IPADDR 1650 1651 Define a default value for the IP address to use for 1652 the default Ethernet interface, in case this is not 1653 determined through e.g. bootp. 1654 (Environment variable "ipaddr") 1655 1656- Server IP address: 1657 CONFIG_SERVERIP 1658 1659 Defines a default value for the IP address of a TFTP 1660 server to contact when using the "tftboot" command. 1661 (Environment variable "serverip") 1662 1663 CONFIG_KEEP_SERVERADDR 1664 1665 Keeps the server's MAC address, in the env 'serveraddr' 1666 for passing to bootargs (like Linux's netconsole option) 1667 1668- Gateway IP address: 1669 CONFIG_GATEWAYIP 1670 1671 Defines a default value for the IP address of the 1672 default router where packets to other networks are 1673 sent to. 1674 (Environment variable "gatewayip") 1675 1676- Subnet mask: 1677 CONFIG_NETMASK 1678 1679 Defines a default value for the subnet mask (or 1680 routing prefix) which is used to determine if an IP 1681 address belongs to the local subnet or needs to be 1682 forwarded through a router. 1683 (Environment variable "netmask") 1684 1685- Multicast TFTP Mode: 1686 CONFIG_MCAST_TFTP 1687 1688 Defines whether you want to support multicast TFTP as per 1689 rfc-2090; for example to work with atftp. Lets lots of targets 1690 tftp down the same boot image concurrently. Note: the Ethernet 1691 driver in use must provide a function: mcast() to join/leave a 1692 multicast group. 1693 1694- BOOTP Recovery Mode: 1695 CONFIG_BOOTP_RANDOM_DELAY 1696 1697 If you have many targets in a network that try to 1698 boot using BOOTP, you may want to avoid that all 1699 systems send out BOOTP requests at precisely the same 1700 moment (which would happen for instance at recovery 1701 from a power failure, when all systems will try to 1702 boot, thus flooding the BOOTP server. Defining 1703 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1704 inserted before sending out BOOTP requests. The 1705 following delays are inserted then: 1706 1707 1st BOOTP request: delay 0 ... 1 sec 1708 2nd BOOTP request: delay 0 ... 2 sec 1709 3rd BOOTP request: delay 0 ... 4 sec 1710 4th and following 1711 BOOTP requests: delay 0 ... 8 sec 1712 1713 CONFIG_BOOTP_ID_CACHE_SIZE 1714 1715 BOOTP packets are uniquely identified using a 32-bit ID. The 1716 server will copy the ID from client requests to responses and 1717 U-Boot will use this to determine if it is the destination of 1718 an incoming response. Some servers will check that addresses 1719 aren't in use before handing them out (usually using an ARP 1720 ping) and therefore take up to a few hundred milliseconds to 1721 respond. Network congestion may also influence the time it 1722 takes for a response to make it back to the client. If that 1723 time is too long, U-Boot will retransmit requests. In order 1724 to allow earlier responses to still be accepted after these 1725 retransmissions, U-Boot's BOOTP client keeps a small cache of 1726 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1727 cache. The default is to keep IDs for up to four outstanding 1728 requests. Increasing this will allow U-Boot to accept offers 1729 from a BOOTP client in networks with unusually high latency. 1730 1731- DHCP Advanced Options: 1732 You can fine tune the DHCP functionality by defining 1733 CONFIG_BOOTP_* symbols: 1734 1735 CONFIG_BOOTP_SUBNETMASK 1736 CONFIG_BOOTP_GATEWAY 1737 CONFIG_BOOTP_HOSTNAME 1738 CONFIG_BOOTP_NISDOMAIN 1739 CONFIG_BOOTP_BOOTPATH 1740 CONFIG_BOOTP_BOOTFILESIZE 1741 CONFIG_BOOTP_DNS 1742 CONFIG_BOOTP_DNS2 1743 CONFIG_BOOTP_SEND_HOSTNAME 1744 CONFIG_BOOTP_NTPSERVER 1745 CONFIG_BOOTP_TIMEOFFSET 1746 CONFIG_BOOTP_VENDOREX 1747 CONFIG_BOOTP_MAY_FAIL 1748 1749 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1750 environment variable, not the BOOTP server. 1751 1752 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1753 after the configured retry count, the call will fail 1754 instead of starting over. This can be used to fail over 1755 to Link-local IP address configuration if the DHCP server 1756 is not available. 1757 1758 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS 1759 serverip from a DHCP server, it is possible that more 1760 than one DNS serverip is offered to the client. 1761 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS 1762 serverip will be stored in the additional environment 1763 variable "dnsip2". The first DNS serverip is always 1764 stored in the variable "dnsip", when CONFIG_BOOTP_DNS 1765 is defined. 1766 1767 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1768 to do a dynamic update of a DNS server. To do this, they 1769 need the hostname of the DHCP requester. 1770 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1771 of the "hostname" environment variable is passed as 1772 option 12 to the DHCP server. 1773 1774 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1775 1776 A 32bit value in microseconds for a delay between 1777 receiving a "DHCP Offer" and sending the "DHCP Request". 1778 This fixes a problem with certain DHCP servers that don't 1779 respond 100% of the time to a "DHCP request". E.g. On an 1780 AT91RM9200 processor running at 180MHz, this delay needed 1781 to be *at least* 15,000 usec before a Windows Server 2003 1782 DHCP server would reply 100% of the time. I recommend at 1783 least 50,000 usec to be safe. The alternative is to hope 1784 that one of the retries will be successful but note that 1785 the DHCP timeout and retry process takes a longer than 1786 this delay. 1787 1788 - Link-local IP address negotiation: 1789 Negotiate with other link-local clients on the local network 1790 for an address that doesn't require explicit configuration. 1791 This is especially useful if a DHCP server cannot be guaranteed 1792 to exist in all environments that the device must operate. 1793 1794 See doc/README.link-local for more information. 1795 1796 - CDP Options: 1797 CONFIG_CDP_DEVICE_ID 1798 1799 The device id used in CDP trigger frames. 1800 1801 CONFIG_CDP_DEVICE_ID_PREFIX 1802 1803 A two character string which is prefixed to the MAC address 1804 of the device. 1805 1806 CONFIG_CDP_PORT_ID 1807 1808 A printf format string which contains the ascii name of 1809 the port. Normally is set to "eth%d" which sets 1810 eth0 for the first Ethernet, eth1 for the second etc. 1811 1812 CONFIG_CDP_CAPABILITIES 1813 1814 A 32bit integer which indicates the device capabilities; 1815 0x00000010 for a normal host which does not forwards. 1816 1817 CONFIG_CDP_VERSION 1818 1819 An ascii string containing the version of the software. 1820 1821 CONFIG_CDP_PLATFORM 1822 1823 An ascii string containing the name of the platform. 1824 1825 CONFIG_CDP_TRIGGER 1826 1827 A 32bit integer sent on the trigger. 1828 1829 CONFIG_CDP_POWER_CONSUMPTION 1830 1831 A 16bit integer containing the power consumption of the 1832 device in .1 of milliwatts. 1833 1834 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1835 1836 A byte containing the id of the VLAN. 1837 1838- Status LED: CONFIG_LED_STATUS 1839 1840 Several configurations allow to display the current 1841 status using a LED. For instance, the LED will blink 1842 fast while running U-Boot code, stop blinking as 1843 soon as a reply to a BOOTP request was received, and 1844 start blinking slow once the Linux kernel is running 1845 (supported by a status LED driver in the Linux 1846 kernel). Defining CONFIG_LED_STATUS enables this 1847 feature in U-Boot. 1848 1849 Additional options: 1850 1851 CONFIG_LED_STATUS_GPIO 1852 The status LED can be connected to a GPIO pin. 1853 In such cases, the gpio_led driver can be used as a 1854 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1855 to include the gpio_led driver in the U-Boot binary. 1856 1857 CONFIG_GPIO_LED_INVERTED_TABLE 1858 Some GPIO connected LEDs may have inverted polarity in which 1859 case the GPIO high value corresponds to LED off state and 1860 GPIO low value corresponds to LED on state. 1861 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1862 with a list of GPIO LEDs that have inverted polarity. 1863 1864- I2C Support: CONFIG_SYS_I2C 1865 1866 This enable the NEW i2c subsystem, and will allow you to use 1867 i2c commands at the u-boot command line (as long as you set 1868 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1869 based realtime clock chips or other i2c devices. See 1870 common/cmd_i2c.c for a description of the command line 1871 interface. 1872 1873 ported i2c driver to the new framework: 1874 - drivers/i2c/soft_i2c.c: 1875 - activate first bus with CONFIG_SYS_I2C_SOFT define 1876 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1877 for defining speed and slave address 1878 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1879 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1880 for defining speed and slave address 1881 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1882 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1883 for defining speed and slave address 1884 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1885 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1886 for defining speed and slave address 1887 1888 - drivers/i2c/fsl_i2c.c: 1889 - activate i2c driver with CONFIG_SYS_I2C_FSL 1890 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1891 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1892 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1893 bus. 1894 - If your board supports a second fsl i2c bus, define 1895 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1896 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1897 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1898 second bus. 1899 1900 - drivers/i2c/tegra_i2c.c: 1901 - activate this driver with CONFIG_SYS_I2C_TEGRA 1902 - This driver adds 4 i2c buses with a fix speed from 1903 100000 and the slave addr 0! 1904 1905 - drivers/i2c/ppc4xx_i2c.c 1906 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1907 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1908 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1909 1910 - drivers/i2c/i2c_mxc.c 1911 - activate this driver with CONFIG_SYS_I2C_MXC 1912 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1913 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1914 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1915 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1916 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1917 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1918 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1919 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1920 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1921 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1922 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1923 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1924 If those defines are not set, default value is 100000 1925 for speed, and 0 for slave. 1926 1927 - drivers/i2c/rcar_i2c.c: 1928 - activate this driver with CONFIG_SYS_I2C_RCAR 1929 - This driver adds 4 i2c buses 1930 1931 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1932 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1933 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1934 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1935 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1936 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1937 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1938 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1939 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1940 1941 - drivers/i2c/sh_i2c.c: 1942 - activate this driver with CONFIG_SYS_I2C_SH 1943 - This driver adds from 2 to 5 i2c buses 1944 1945 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1946 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1947 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1948 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1949 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1950 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1951 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1952 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1953 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1954 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1955 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1956 1957 - drivers/i2c/omap24xx_i2c.c 1958 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1959 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1960 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1961 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1962 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1963 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1964 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1965 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1966 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1967 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1968 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1969 1970 - drivers/i2c/zynq_i2c.c 1971 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1972 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1973 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1974 1975 - drivers/i2c/s3c24x0_i2c.c: 1976 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1977 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1978 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1979 with a fix speed from 100000 and the slave addr 0! 1980 1981 - drivers/i2c/ihs_i2c.c 1982 - activate this driver with CONFIG_SYS_I2C_IHS 1983 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1984 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1985 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1986 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1987 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1988 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1989 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1990 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1991 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1992 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1993 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1994 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1995 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1996 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1997 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1998 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1999 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 2000 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 2001 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 2002 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 2003 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 2004 2005 additional defines: 2006 2007 CONFIG_SYS_NUM_I2C_BUSES 2008 Hold the number of i2c buses you want to use. 2009 2010 CONFIG_SYS_I2C_DIRECT_BUS 2011 define this, if you don't use i2c muxes on your hardware. 2012 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 2013 omit this define. 2014 2015 CONFIG_SYS_I2C_MAX_HOPS 2016 define how many muxes are maximal consecutively connected 2017 on one i2c bus. If you not use i2c muxes, omit this 2018 define. 2019 2020 CONFIG_SYS_I2C_BUSES 2021 hold a list of buses you want to use, only used if 2022 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 2023 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 2024 CONFIG_SYS_NUM_I2C_BUSES = 9: 2025 2026 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 2027 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 2028 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 2029 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 2030 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 2031 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 2032 {1, {I2C_NULL_HOP}}, \ 2033 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 2034 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 2035 } 2036 2037 which defines 2038 bus 0 on adapter 0 without a mux 2039 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 2040 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 2041 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 2042 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 2043 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 2044 bus 6 on adapter 1 without a mux 2045 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 2046 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 2047 2048 If you do not have i2c muxes on your board, omit this define. 2049 2050- Legacy I2C Support: 2051 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 2052 then the following macros need to be defined (examples are 2053 from include/configs/lwmon.h): 2054 2055 I2C_INIT 2056 2057 (Optional). Any commands necessary to enable the I2C 2058 controller or configure ports. 2059 2060 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 2061 2062 I2C_ACTIVE 2063 2064 The code necessary to make the I2C data line active 2065 (driven). If the data line is open collector, this 2066 define can be null. 2067 2068 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 2069 2070 I2C_TRISTATE 2071 2072 The code necessary to make the I2C data line tri-stated 2073 (inactive). If the data line is open collector, this 2074 define can be null. 2075 2076 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 2077 2078 I2C_READ 2079 2080 Code that returns true if the I2C data line is high, 2081 false if it is low. 2082 2083 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 2084 2085 I2C_SDA(bit) 2086 2087 If <bit> is true, sets the I2C data line high. If it 2088 is false, it clears it (low). 2089 2090 eg: #define I2C_SDA(bit) \ 2091 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 2092 else immr->im_cpm.cp_pbdat &= ~PB_SDA 2093 2094 I2C_SCL(bit) 2095 2096 If <bit> is true, sets the I2C clock line high. If it 2097 is false, it clears it (low). 2098 2099 eg: #define I2C_SCL(bit) \ 2100 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 2101 else immr->im_cpm.cp_pbdat &= ~PB_SCL 2102 2103 I2C_DELAY 2104 2105 This delay is invoked four times per clock cycle so this 2106 controls the rate of data transfer. The data rate thus 2107 is 1 / (I2C_DELAY * 4). Often defined to be something 2108 like: 2109 2110 #define I2C_DELAY udelay(2) 2111 2112 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 2113 2114 If your arch supports the generic GPIO framework (asm/gpio.h), 2115 then you may alternatively define the two GPIOs that are to be 2116 used as SCL / SDA. Any of the previous I2C_xxx macros will 2117 have GPIO-based defaults assigned to them as appropriate. 2118 2119 You should define these to the GPIO value as given directly to 2120 the generic GPIO functions. 2121 2122 CONFIG_SYS_I2C_INIT_BOARD 2123 2124 When a board is reset during an i2c bus transfer 2125 chips might think that the current transfer is still 2126 in progress. On some boards it is possible to access 2127 the i2c SCLK line directly, either by using the 2128 processor pin as a GPIO or by having a second pin 2129 connected to the bus. If this option is defined a 2130 custom i2c_init_board() routine in boards/xxx/board.c 2131 is run early in the boot sequence. 2132 2133 CONFIG_I2C_MULTI_BUS 2134 2135 This option allows the use of multiple I2C buses, each of which 2136 must have a controller. At any point in time, only one bus is 2137 active. To switch to a different bus, use the 'i2c dev' command. 2138 Note that bus numbering is zero-based. 2139 2140 CONFIG_SYS_I2C_NOPROBES 2141 2142 This option specifies a list of I2C devices that will be skipped 2143 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 2144 is set, specify a list of bus-device pairs. Otherwise, specify 2145 a 1D array of device addresses 2146 2147 e.g. 2148 #undef CONFIG_I2C_MULTI_BUS 2149 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 2150 2151 will skip addresses 0x50 and 0x68 on a board with one I2C bus 2152 2153 #define CONFIG_I2C_MULTI_BUS 2154 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 2155 2156 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 2157 2158 CONFIG_SYS_SPD_BUS_NUM 2159 2160 If defined, then this indicates the I2C bus number for DDR SPD. 2161 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 2162 2163 CONFIG_SYS_RTC_BUS_NUM 2164 2165 If defined, then this indicates the I2C bus number for the RTC. 2166 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 2167 2168 CONFIG_SOFT_I2C_READ_REPEATED_START 2169 2170 defining this will force the i2c_read() function in 2171 the soft_i2c driver to perform an I2C repeated start 2172 between writing the address pointer and reading the 2173 data. If this define is omitted the default behaviour 2174 of doing a stop-start sequence will be used. Most I2C 2175 devices can use either method, but some require one or 2176 the other. 2177 2178- SPI Support: CONFIG_SPI 2179 2180 Enables SPI driver (so far only tested with 2181 SPI EEPROM, also an instance works with Crystal A/D and 2182 D/As on the SACSng board) 2183 2184 CONFIG_SH_SPI 2185 2186 Enables the driver for SPI controller on SuperH. Currently 2187 only SH7757 is supported. 2188 2189 CONFIG_SOFT_SPI 2190 2191 Enables a software (bit-bang) SPI driver rather than 2192 using hardware support. This is a general purpose 2193 driver that only requires three general I/O port pins 2194 (two outputs, one input) to function. If this is 2195 defined, the board configuration must define several 2196 SPI configuration items (port pins to use, etc). For 2197 an example, see include/configs/sacsng.h. 2198 2199 CONFIG_HARD_SPI 2200 2201 Enables a hardware SPI driver for general-purpose reads 2202 and writes. As with CONFIG_SOFT_SPI, the board configuration 2203 must define a list of chip-select function pointers. 2204 Currently supported on some MPC8xxx processors. For an 2205 example, see include/configs/mpc8349emds.h. 2206 2207 CONFIG_MXC_SPI 2208 2209 Enables the driver for the SPI controllers on i.MX and MXC 2210 SoCs. Currently i.MX31/35/51 are supported. 2211 2212 CONFIG_SYS_SPI_MXC_WAIT 2213 Timeout for waiting until spi transfer completed. 2214 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2215 2216- FPGA Support: CONFIG_FPGA 2217 2218 Enables FPGA subsystem. 2219 2220 CONFIG_FPGA_<vendor> 2221 2222 Enables support for specific chip vendors. 2223 (ALTERA, XILINX) 2224 2225 CONFIG_FPGA_<family> 2226 2227 Enables support for FPGA family. 2228 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2229 2230 CONFIG_FPGA_COUNT 2231 2232 Specify the number of FPGA devices to support. 2233 2234 CONFIG_SYS_FPGA_PROG_FEEDBACK 2235 2236 Enable printing of hash marks during FPGA configuration. 2237 2238 CONFIG_SYS_FPGA_CHECK_BUSY 2239 2240 Enable checks on FPGA configuration interface busy 2241 status by the configuration function. This option 2242 will require a board or device specific function to 2243 be written. 2244 2245 CONFIG_FPGA_DELAY 2246 2247 If defined, a function that provides delays in the FPGA 2248 configuration driver. 2249 2250 CONFIG_SYS_FPGA_CHECK_CTRLC 2251 Allow Control-C to interrupt FPGA configuration 2252 2253 CONFIG_SYS_FPGA_CHECK_ERROR 2254 2255 Check for configuration errors during FPGA bitfile 2256 loading. For example, abort during Virtex II 2257 configuration if the INIT_B line goes low (which 2258 indicated a CRC error). 2259 2260 CONFIG_SYS_FPGA_WAIT_INIT 2261 2262 Maximum time to wait for the INIT_B line to de-assert 2263 after PROB_B has been de-asserted during a Virtex II 2264 FPGA configuration sequence. The default time is 500 2265 ms. 2266 2267 CONFIG_SYS_FPGA_WAIT_BUSY 2268 2269 Maximum time to wait for BUSY to de-assert during 2270 Virtex II FPGA configuration. The default is 5 ms. 2271 2272 CONFIG_SYS_FPGA_WAIT_CONFIG 2273 2274 Time to wait after FPGA configuration. The default is 2275 200 ms. 2276 2277- Configuration Management: 2278 CONFIG_BUILD_TARGET 2279 2280 Some SoCs need special image types (e.g. U-Boot binary 2281 with a special header) as build targets. By defining 2282 CONFIG_BUILD_TARGET in the SoC / board header, this 2283 special image will be automatically built upon calling 2284 make / buildman. 2285 2286 CONFIG_IDENT_STRING 2287 2288 If defined, this string will be added to the U-Boot 2289 version information (U_BOOT_VERSION) 2290 2291- Vendor Parameter Protection: 2292 2293 U-Boot considers the values of the environment 2294 variables "serial#" (Board Serial Number) and 2295 "ethaddr" (Ethernet Address) to be parameters that 2296 are set once by the board vendor / manufacturer, and 2297 protects these variables from casual modification by 2298 the user. Once set, these variables are read-only, 2299 and write or delete attempts are rejected. You can 2300 change this behaviour: 2301 2302 If CONFIG_ENV_OVERWRITE is #defined in your config 2303 file, the write protection for vendor parameters is 2304 completely disabled. Anybody can change or delete 2305 these parameters. 2306 2307 Alternatively, if you define _both_ an ethaddr in the 2308 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2309 Ethernet address is installed in the environment, 2310 which can be changed exactly ONCE by the user. [The 2311 serial# is unaffected by this, i. e. it remains 2312 read-only.] 2313 2314 The same can be accomplished in a more flexible way 2315 for any variable by configuring the type of access 2316 to allow for those variables in the ".flags" variable 2317 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2318 2319- Protected RAM: 2320 CONFIG_PRAM 2321 2322 Define this variable to enable the reservation of 2323 "protected RAM", i. e. RAM which is not overwritten 2324 by U-Boot. Define CONFIG_PRAM to hold the number of 2325 kB you want to reserve for pRAM. You can overwrite 2326 this default value by defining an environment 2327 variable "pram" to the number of kB you want to 2328 reserve. Note that the board info structure will 2329 still show the full amount of RAM. If pRAM is 2330 reserved, a new environment variable "mem" will 2331 automatically be defined to hold the amount of 2332 remaining RAM in a form that can be passed as boot 2333 argument to Linux, for instance like that: 2334 2335 setenv bootargs ... mem=\${mem} 2336 saveenv 2337 2338 This way you can tell Linux not to use this memory, 2339 either, which results in a memory region that will 2340 not be affected by reboots. 2341 2342 *WARNING* If your board configuration uses automatic 2343 detection of the RAM size, you must make sure that 2344 this memory test is non-destructive. So far, the 2345 following board configurations are known to be 2346 "pRAM-clean": 2347 2348 IVMS8, IVML24, SPD8xx, 2349 HERMES, IP860, RPXlite, LWMON, 2350 FLAGADM 2351 2352- Access to physical memory region (> 4GB) 2353 Some basic support is provided for operations on memory not 2354 normally accessible to U-Boot - e.g. some architectures 2355 support access to more than 4GB of memory on 32-bit 2356 machines using physical address extension or similar. 2357 Define CONFIG_PHYSMEM to access this basic support, which 2358 currently only supports clearing the memory. 2359 2360- Error Recovery: 2361 CONFIG_PANIC_HANG 2362 2363 Define this variable to stop the system in case of a 2364 fatal error, so that you have to reset it manually. 2365 This is probably NOT a good idea for an embedded 2366 system where you want the system to reboot 2367 automatically as fast as possible, but it may be 2368 useful during development since you can try to debug 2369 the conditions that lead to the situation. 2370 2371 CONFIG_NET_RETRY_COUNT 2372 2373 This variable defines the number of retries for 2374 network operations like ARP, RARP, TFTP, or BOOTP 2375 before giving up the operation. If not defined, a 2376 default value of 5 is used. 2377 2378 CONFIG_ARP_TIMEOUT 2379 2380 Timeout waiting for an ARP reply in milliseconds. 2381 2382 CONFIG_NFS_TIMEOUT 2383 2384 Timeout in milliseconds used in NFS protocol. 2385 If you encounter "ERROR: Cannot umount" in nfs command, 2386 try longer timeout such as 2387 #define CONFIG_NFS_TIMEOUT 10000UL 2388 2389- Command Interpreter: 2390 CONFIG_AUTO_COMPLETE 2391 2392 Enable auto completion of commands using TAB. 2393 2394 CONFIG_SYS_PROMPT_HUSH_PS2 2395 2396 This defines the secondary prompt string, which is 2397 printed when the command interpreter needs more input 2398 to complete a command. Usually "> ". 2399 2400 Note: 2401 2402 In the current implementation, the local variables 2403 space and global environment variables space are 2404 separated. Local variables are those you define by 2405 simply typing `name=value'. To access a local 2406 variable later on, you have write `$name' or 2407 `${name}'; to execute the contents of a variable 2408 directly type `$name' at the command prompt. 2409 2410 Global environment variables are those you use 2411 setenv/printenv to work with. To run a command stored 2412 in such a variable, you need to use the run command, 2413 and you must not use the '$' sign to access them. 2414 2415 To store commands and special characters in a 2416 variable, please use double quotation marks 2417 surrounding the whole text of the variable, instead 2418 of the backslashes before semicolons and special 2419 symbols. 2420 2421- Command Line Editing and History: 2422 CONFIG_CMDLINE_EDITING 2423 2424 Enable editing and History functions for interactive 2425 command line input operations 2426 2427- Command Line PS1/PS2 support: 2428 CONFIG_CMDLINE_PS_SUPPORT 2429 2430 Enable support for changing the command prompt string 2431 at run-time. Only static string is supported so far. 2432 The string is obtained from environment variables PS1 2433 and PS2. 2434 2435- Default Environment: 2436 CONFIG_EXTRA_ENV_SETTINGS 2437 2438 Define this to contain any number of null terminated 2439 strings (variable = value pairs) that will be part of 2440 the default environment compiled into the boot image. 2441 2442 For example, place something like this in your 2443 board's config file: 2444 2445 #define CONFIG_EXTRA_ENV_SETTINGS \ 2446 "myvar1=value1\0" \ 2447 "myvar2=value2\0" 2448 2449 Warning: This method is based on knowledge about the 2450 internal format how the environment is stored by the 2451 U-Boot code. This is NOT an official, exported 2452 interface! Although it is unlikely that this format 2453 will change soon, there is no guarantee either. 2454 You better know what you are doing here. 2455 2456 Note: overly (ab)use of the default environment is 2457 discouraged. Make sure to check other ways to preset 2458 the environment like the "source" command or the 2459 boot command first. 2460 2461 CONFIG_ENV_VARS_UBOOT_CONFIG 2462 2463 Define this in order to add variables describing the 2464 U-Boot build configuration to the default environment. 2465 These will be named arch, cpu, board, vendor, and soc. 2466 2467 Enabling this option will cause the following to be defined: 2468 2469 - CONFIG_SYS_ARCH 2470 - CONFIG_SYS_CPU 2471 - CONFIG_SYS_BOARD 2472 - CONFIG_SYS_VENDOR 2473 - CONFIG_SYS_SOC 2474 2475 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2476 2477 Define this in order to add variables describing certain 2478 run-time determined information about the hardware to the 2479 environment. These will be named board_name, board_rev. 2480 2481 CONFIG_DELAY_ENVIRONMENT 2482 2483 Normally the environment is loaded when the board is 2484 initialised so that it is available to U-Boot. This inhibits 2485 that so that the environment is not available until 2486 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2487 this is instead controlled by the value of 2488 /config/load-environment. 2489 2490- DataFlash Support: 2491 CONFIG_HAS_DATAFLASH 2492 2493 Defining this option enables DataFlash features and 2494 allows to read/write in Dataflash via the standard 2495 commands cp, md... 2496 2497- Serial Flash support 2498 CONFIG_CMD_SF 2499 2500 Defining this option enables SPI flash commands 2501 'sf probe/read/write/erase/update'. 2502 2503 Usage requires an initial 'probe' to define the serial 2504 flash parameters, followed by read/write/erase/update 2505 commands. 2506 2507 The following defaults may be provided by the platform 2508 to handle the common case when only a single serial 2509 flash is present on the system. 2510 2511 CONFIG_SF_DEFAULT_BUS Bus identifier 2512 CONFIG_SF_DEFAULT_CS Chip-select 2513 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2514 CONFIG_SF_DEFAULT_SPEED in Hz 2515 2516 CONFIG_CMD_SF_TEST 2517 2518 Define this option to include a destructive SPI flash 2519 test ('sf test'). 2520 2521- SystemACE Support: 2522 CONFIG_SYSTEMACE 2523 2524 Adding this option adds support for Xilinx SystemACE 2525 chips attached via some sort of local bus. The address 2526 of the chip must also be defined in the 2527 CONFIG_SYS_SYSTEMACE_BASE macro. For example: 2528 2529 #define CONFIG_SYSTEMACE 2530 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000 2531 2532 When SystemACE support is added, the "ace" device type 2533 becomes available to the fat commands, i.e. fatls. 2534 2535- TFTP Fixed UDP Port: 2536 CONFIG_TFTP_PORT 2537 2538 If this is defined, the environment variable tftpsrcp 2539 is used to supply the TFTP UDP source port value. 2540 If tftpsrcp isn't defined, the normal pseudo-random port 2541 number generator is used. 2542 2543 Also, the environment variable tftpdstp is used to supply 2544 the TFTP UDP destination port value. If tftpdstp isn't 2545 defined, the normal port 69 is used. 2546 2547 The purpose for tftpsrcp is to allow a TFTP server to 2548 blindly start the TFTP transfer using the pre-configured 2549 target IP address and UDP port. This has the effect of 2550 "punching through" the (Windows XP) firewall, allowing 2551 the remainder of the TFTP transfer to proceed normally. 2552 A better solution is to properly configure the firewall, 2553 but sometimes that is not allowed. 2554 2555- bootcount support: 2556 CONFIG_BOOTCOUNT_LIMIT 2557 2558 This enables the bootcounter support, see: 2559 http://www.denx.de/wiki/DULG/UBootBootCountLimit 2560 2561 CONFIG_AT91SAM9XE 2562 enable special bootcounter support on at91sam9xe based boards. 2563 CONFIG_SOC_DA8XX 2564 enable special bootcounter support on da850 based boards. 2565 CONFIG_BOOTCOUNT_RAM 2566 enable support for the bootcounter in RAM 2567 CONFIG_BOOTCOUNT_I2C 2568 enable support for the bootcounter on an i2c (like RTC) device. 2569 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2570 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2571 the bootcounter. 2572 CONFIG_BOOTCOUNT_ALEN = address len 2573 2574- Show boot progress: 2575 CONFIG_SHOW_BOOT_PROGRESS 2576 2577 Defining this option allows to add some board- 2578 specific code (calling a user-provided function 2579 "show_boot_progress(int)") that enables you to show 2580 the system's boot progress on some display (for 2581 example, some LED's) on your board. At the moment, 2582 the following checkpoints are implemented: 2583 2584 2585Legacy uImage format: 2586 2587 Arg Where When 2588 1 common/cmd_bootm.c before attempting to boot an image 2589 -1 common/cmd_bootm.c Image header has bad magic number 2590 2 common/cmd_bootm.c Image header has correct magic number 2591 -2 common/cmd_bootm.c Image header has bad checksum 2592 3 common/cmd_bootm.c Image header has correct checksum 2593 -3 common/cmd_bootm.c Image data has bad checksum 2594 4 common/cmd_bootm.c Image data has correct checksum 2595 -4 common/cmd_bootm.c Image is for unsupported architecture 2596 5 common/cmd_bootm.c Architecture check OK 2597 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2598 6 common/cmd_bootm.c Image Type check OK 2599 -6 common/cmd_bootm.c gunzip uncompression error 2600 -7 common/cmd_bootm.c Unimplemented compression type 2601 7 common/cmd_bootm.c Uncompression OK 2602 8 common/cmd_bootm.c No uncompress/copy overwrite error 2603 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2604 2605 9 common/image.c Start initial ramdisk verification 2606 -10 common/image.c Ramdisk header has bad magic number 2607 -11 common/image.c Ramdisk header has bad checksum 2608 10 common/image.c Ramdisk header is OK 2609 -12 common/image.c Ramdisk data has bad checksum 2610 11 common/image.c Ramdisk data has correct checksum 2611 12 common/image.c Ramdisk verification complete, start loading 2612 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2613 13 common/image.c Start multifile image verification 2614 14 common/image.c No initial ramdisk, no multifile, continue. 2615 2616 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2617 2618 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2619 -31 post/post.c POST test failed, detected by post_output_backlog() 2620 -32 post/post.c POST test failed, detected by post_run_single() 2621 2622 34 common/cmd_doc.c before loading a Image from a DOC device 2623 -35 common/cmd_doc.c Bad usage of "doc" command 2624 35 common/cmd_doc.c correct usage of "doc" command 2625 -36 common/cmd_doc.c No boot device 2626 36 common/cmd_doc.c correct boot device 2627 -37 common/cmd_doc.c Unknown Chip ID on boot device 2628 37 common/cmd_doc.c correct chip ID found, device available 2629 -38 common/cmd_doc.c Read Error on boot device 2630 38 common/cmd_doc.c reading Image header from DOC device OK 2631 -39 common/cmd_doc.c Image header has bad magic number 2632 39 common/cmd_doc.c Image header has correct magic number 2633 -40 common/cmd_doc.c Error reading Image from DOC device 2634 40 common/cmd_doc.c Image header has correct magic number 2635 41 common/cmd_ide.c before loading a Image from a IDE device 2636 -42 common/cmd_ide.c Bad usage of "ide" command 2637 42 common/cmd_ide.c correct usage of "ide" command 2638 -43 common/cmd_ide.c No boot device 2639 43 common/cmd_ide.c boot device found 2640 -44 common/cmd_ide.c Device not available 2641 44 common/cmd_ide.c Device available 2642 -45 common/cmd_ide.c wrong partition selected 2643 45 common/cmd_ide.c partition selected 2644 -46 common/cmd_ide.c Unknown partition table 2645 46 common/cmd_ide.c valid partition table found 2646 -47 common/cmd_ide.c Invalid partition type 2647 47 common/cmd_ide.c correct partition type 2648 -48 common/cmd_ide.c Error reading Image Header on boot device 2649 48 common/cmd_ide.c reading Image Header from IDE device OK 2650 -49 common/cmd_ide.c Image header has bad magic number 2651 49 common/cmd_ide.c Image header has correct magic number 2652 -50 common/cmd_ide.c Image header has bad checksum 2653 50 common/cmd_ide.c Image header has correct checksum 2654 -51 common/cmd_ide.c Error reading Image from IDE device 2655 51 common/cmd_ide.c reading Image from IDE device OK 2656 52 common/cmd_nand.c before loading a Image from a NAND device 2657 -53 common/cmd_nand.c Bad usage of "nand" command 2658 53 common/cmd_nand.c correct usage of "nand" command 2659 -54 common/cmd_nand.c No boot device 2660 54 common/cmd_nand.c boot device found 2661 -55 common/cmd_nand.c Unknown Chip ID on boot device 2662 55 common/cmd_nand.c correct chip ID found, device available 2663 -56 common/cmd_nand.c Error reading Image Header on boot device 2664 56 common/cmd_nand.c reading Image Header from NAND device OK 2665 -57 common/cmd_nand.c Image header has bad magic number 2666 57 common/cmd_nand.c Image header has correct magic number 2667 -58 common/cmd_nand.c Error reading Image from NAND device 2668 58 common/cmd_nand.c reading Image from NAND device OK 2669 2670 -60 common/env_common.c Environment has a bad CRC, using default 2671 2672 64 net/eth.c starting with Ethernet configuration. 2673 -64 net/eth.c no Ethernet found. 2674 65 net/eth.c Ethernet found. 2675 2676 -80 common/cmd_net.c usage wrong 2677 80 common/cmd_net.c before calling net_loop() 2678 -81 common/cmd_net.c some error in net_loop() occurred 2679 81 common/cmd_net.c net_loop() back without error 2680 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2681 82 common/cmd_net.c trying automatic boot 2682 83 common/cmd_net.c running "source" command 2683 -83 common/cmd_net.c some error in automatic boot or "source" command 2684 84 common/cmd_net.c end without errors 2685 2686FIT uImage format: 2687 2688 Arg Where When 2689 100 common/cmd_bootm.c Kernel FIT Image has correct format 2690 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2691 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2692 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2693 102 common/cmd_bootm.c Kernel unit name specified 2694 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2695 103 common/cmd_bootm.c Found configuration node 2696 104 common/cmd_bootm.c Got kernel subimage node offset 2697 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2698 105 common/cmd_bootm.c Kernel subimage hash verification OK 2699 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2700 106 common/cmd_bootm.c Architecture check OK 2701 -106 common/cmd_bootm.c Kernel subimage has wrong type 2702 107 common/cmd_bootm.c Kernel subimage type OK 2703 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2704 108 common/cmd_bootm.c Got kernel subimage data/size 2705 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2706 -109 common/cmd_bootm.c Can't get kernel subimage type 2707 -110 common/cmd_bootm.c Can't get kernel subimage comp 2708 -111 common/cmd_bootm.c Can't get kernel subimage os 2709 -112 common/cmd_bootm.c Can't get kernel subimage load address 2710 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2711 2712 120 common/image.c Start initial ramdisk verification 2713 -120 common/image.c Ramdisk FIT image has incorrect format 2714 121 common/image.c Ramdisk FIT image has correct format 2715 122 common/image.c No ramdisk subimage unit name, using configuration 2716 -122 common/image.c Can't get configuration for ramdisk subimage 2717 123 common/image.c Ramdisk unit name specified 2718 -124 common/image.c Can't get ramdisk subimage node offset 2719 125 common/image.c Got ramdisk subimage node offset 2720 -125 common/image.c Ramdisk subimage hash verification failed 2721 126 common/image.c Ramdisk subimage hash verification OK 2722 -126 common/image.c Ramdisk subimage for unsupported architecture 2723 127 common/image.c Architecture check OK 2724 -127 common/image.c Can't get ramdisk subimage data/size 2725 128 common/image.c Got ramdisk subimage data/size 2726 129 common/image.c Can't get ramdisk load address 2727 -129 common/image.c Got ramdisk load address 2728 2729 -130 common/cmd_doc.c Incorrect FIT image format 2730 131 common/cmd_doc.c FIT image format OK 2731 2732 -140 common/cmd_ide.c Incorrect FIT image format 2733 141 common/cmd_ide.c FIT image format OK 2734 2735 -150 common/cmd_nand.c Incorrect FIT image format 2736 151 common/cmd_nand.c FIT image format OK 2737 2738- legacy image format: 2739 CONFIG_IMAGE_FORMAT_LEGACY 2740 enables the legacy image format support in U-Boot. 2741 2742 Default: 2743 enabled if CONFIG_FIT_SIGNATURE is not defined. 2744 2745 CONFIG_DISABLE_IMAGE_LEGACY 2746 disable the legacy image format 2747 2748 This define is introduced, as the legacy image format is 2749 enabled per default for backward compatibility. 2750 2751- Standalone program support: 2752 CONFIG_STANDALONE_LOAD_ADDR 2753 2754 This option defines a board specific value for the 2755 address where standalone program gets loaded, thus 2756 overwriting the architecture dependent default 2757 settings. 2758 2759- Frame Buffer Address: 2760 CONFIG_FB_ADDR 2761 2762 Define CONFIG_FB_ADDR if you want to use specific 2763 address for frame buffer. This is typically the case 2764 when using a graphics controller has separate video 2765 memory. U-Boot will then place the frame buffer at 2766 the given address instead of dynamically reserving it 2767 in system RAM by calling lcd_setmem(), which grabs 2768 the memory for the frame buffer depending on the 2769 configured panel size. 2770 2771 Please see board_init_f function. 2772 2773- Automatic software updates via TFTP server 2774 CONFIG_UPDATE_TFTP 2775 CONFIG_UPDATE_TFTP_CNT_MAX 2776 CONFIG_UPDATE_TFTP_MSEC_MAX 2777 2778 These options enable and control the auto-update feature; 2779 for a more detailed description refer to doc/README.update. 2780 2781- MTD Support (mtdparts command, UBI support) 2782 CONFIG_MTD_DEVICE 2783 2784 Adds the MTD device infrastructure from the Linux kernel. 2785 Needed for mtdparts command support. 2786 2787 CONFIG_MTD_PARTITIONS 2788 2789 Adds the MTD partitioning infrastructure from the Linux 2790 kernel. Needed for UBI support. 2791 2792- UBI support 2793 CONFIG_UBI_SILENCE_MSG 2794 2795 Make the verbose messages from UBI stop printing. This leaves 2796 warnings and errors enabled. 2797 2798 2799 CONFIG_MTD_UBI_WL_THRESHOLD 2800 This parameter defines the maximum difference between the highest 2801 erase counter value and the lowest erase counter value of eraseblocks 2802 of UBI devices. When this threshold is exceeded, UBI starts performing 2803 wear leveling by means of moving data from eraseblock with low erase 2804 counter to eraseblocks with high erase counter. 2805 2806 The default value should be OK for SLC NAND flashes, NOR flashes and 2807 other flashes which have eraseblock life-cycle 100000 or more. 2808 However, in case of MLC NAND flashes which typically have eraseblock 2809 life-cycle less than 10000, the threshold should be lessened (e.g., 2810 to 128 or 256, although it does not have to be power of 2). 2811 2812 default: 4096 2813 2814 CONFIG_MTD_UBI_BEB_LIMIT 2815 This option specifies the maximum bad physical eraseblocks UBI 2816 expects on the MTD device (per 1024 eraseblocks). If the 2817 underlying flash does not admit of bad eraseblocks (e.g. NOR 2818 flash), this value is ignored. 2819 2820 NAND datasheets often specify the minimum and maximum NVM 2821 (Number of Valid Blocks) for the flashes' endurance lifetime. 2822 The maximum expected bad eraseblocks per 1024 eraseblocks 2823 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2824 which gives 20 for most NANDs (MaxNVB is basically the total 2825 count of eraseblocks on the chip). 2826 2827 To put it differently, if this value is 20, UBI will try to 2828 reserve about 1.9% of physical eraseblocks for bad blocks 2829 handling. And that will be 1.9% of eraseblocks on the entire 2830 NAND chip, not just the MTD partition UBI attaches. This means 2831 that if you have, say, a NAND flash chip admits maximum 40 bad 2832 eraseblocks, and it is split on two MTD partitions of the same 2833 size, UBI will reserve 40 eraseblocks when attaching a 2834 partition. 2835 2836 default: 20 2837 2838 CONFIG_MTD_UBI_FASTMAP 2839 Fastmap is a mechanism which allows attaching an UBI device 2840 in nearly constant time. Instead of scanning the whole MTD device it 2841 only has to locate a checkpoint (called fastmap) on the device. 2842 The on-flash fastmap contains all information needed to attach 2843 the device. Using fastmap makes only sense on large devices where 2844 attaching by scanning takes long. UBI will not automatically install 2845 a fastmap on old images, but you can set the UBI parameter 2846 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2847 that fastmap-enabled images are still usable with UBI implementations 2848 without fastmap support. On typical flash devices the whole fastmap 2849 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2850 2851 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2852 Set this parameter to enable fastmap automatically on images 2853 without a fastmap. 2854 default: 0 2855 2856 CONFIG_MTD_UBI_FM_DEBUG 2857 Enable UBI fastmap debug 2858 default: 0 2859 2860- UBIFS support 2861 CONFIG_UBIFS_SILENCE_MSG 2862 2863 Make the verbose messages from UBIFS stop printing. This leaves 2864 warnings and errors enabled. 2865 2866- SPL framework 2867 CONFIG_SPL 2868 Enable building of SPL globally. 2869 2870 CONFIG_SPL_LDSCRIPT 2871 LDSCRIPT for linking the SPL binary. 2872 2873 CONFIG_SPL_MAX_FOOTPRINT 2874 Maximum size in memory allocated to the SPL, BSS included. 2875 When defined, the linker checks that the actual memory 2876 used by SPL from _start to __bss_end does not exceed it. 2877 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2878 must not be both defined at the same time. 2879 2880 CONFIG_SPL_MAX_SIZE 2881 Maximum size of the SPL image (text, data, rodata, and 2882 linker lists sections), BSS excluded. 2883 When defined, the linker checks that the actual size does 2884 not exceed it. 2885 2886 CONFIG_SPL_TEXT_BASE 2887 TEXT_BASE for linking the SPL binary. 2888 2889 CONFIG_SPL_RELOC_TEXT_BASE 2890 Address to relocate to. If unspecified, this is equal to 2891 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2892 2893 CONFIG_SPL_BSS_START_ADDR 2894 Link address for the BSS within the SPL binary. 2895 2896 CONFIG_SPL_BSS_MAX_SIZE 2897 Maximum size in memory allocated to the SPL BSS. 2898 When defined, the linker checks that the actual memory used 2899 by SPL from __bss_start to __bss_end does not exceed it. 2900 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2901 must not be both defined at the same time. 2902 2903 CONFIG_SPL_STACK 2904 Adress of the start of the stack SPL will use 2905 2906 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2907 When defined, SPL will panic() if the image it has 2908 loaded does not have a signature. 2909 Defining this is useful when code which loads images 2910 in SPL cannot guarantee that absolutely all read errors 2911 will be caught. 2912 An example is the LPC32XX MLC NAND driver, which will 2913 consider that a completely unreadable NAND block is bad, 2914 and thus should be skipped silently. 2915 2916 CONFIG_SPL_RELOC_STACK 2917 Adress of the start of the stack SPL will use after 2918 relocation. If unspecified, this is equal to 2919 CONFIG_SPL_STACK. 2920 2921 CONFIG_SYS_SPL_MALLOC_START 2922 Starting address of the malloc pool used in SPL. 2923 When this option is set the full malloc is used in SPL and 2924 it is set up by spl_init() and before that, the simple malloc() 2925 can be used if CONFIG_SYS_MALLOC_F is defined. 2926 2927 CONFIG_SYS_SPL_MALLOC_SIZE 2928 The size of the malloc pool used in SPL. 2929 2930 CONFIG_SPL_FRAMEWORK 2931 Enable the SPL framework under common/. This framework 2932 supports MMC, NAND and YMODEM loading of U-Boot and NAND 2933 NAND loading of the Linux Kernel. 2934 2935 CONFIG_SPL_OS_BOOT 2936 Enable booting directly to an OS from SPL. 2937 See also: doc/README.falcon 2938 2939 CONFIG_SPL_DISPLAY_PRINT 2940 For ARM, enable an optional function to print more information 2941 about the running system. 2942 2943 CONFIG_SPL_INIT_MINIMAL 2944 Arch init code should be built for a very small image 2945 2946 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2947 Partition on the MMC to load U-Boot from when the MMC is being 2948 used in raw mode 2949 2950 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2951 Sector to load kernel uImage from when MMC is being 2952 used in raw mode (for Falcon mode) 2953 2954 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2955 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2956 Sector and number of sectors to load kernel argument 2957 parameters from when MMC is being used in raw mode 2958 (for falcon mode) 2959 2960 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2961 Partition on the MMC to load U-Boot from when the MMC is being 2962 used in fs mode 2963 2964 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2965 Filename to read to load U-Boot when reading from filesystem 2966 2967 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2968 Filename to read to load kernel uImage when reading 2969 from filesystem (for Falcon mode) 2970 2971 CONFIG_SPL_FS_LOAD_ARGS_NAME 2972 Filename to read to load kernel argument parameters 2973 when reading from filesystem (for Falcon mode) 2974 2975 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2976 Set this for NAND SPL on PPC mpc83xx targets, so that 2977 start.S waits for the rest of the SPL to load before 2978 continuing (the hardware starts execution after just 2979 loading the first page rather than the full 4K). 2980 2981 CONFIG_SPL_SKIP_RELOCATE 2982 Avoid SPL relocation 2983 2984 CONFIG_SPL_NAND_BASE 2985 Include nand_base.c in the SPL. Requires 2986 CONFIG_SPL_NAND_DRIVERS. 2987 2988 CONFIG_SPL_NAND_DRIVERS 2989 SPL uses normal NAND drivers, not minimal drivers. 2990 2991 CONFIG_SPL_NAND_ECC 2992 Include standard software ECC in the SPL 2993 2994 CONFIG_SPL_NAND_SIMPLE 2995 Support for NAND boot using simple NAND drivers that 2996 expose the cmd_ctrl() interface. 2997 2998 CONFIG_SPL_UBI 2999 Support for a lightweight UBI (fastmap) scanner and 3000 loader 3001 3002 CONFIG_SPL_NAND_RAW_ONLY 3003 Support to boot only raw u-boot.bin images. Use this only 3004 if you need to save space. 3005 3006 CONFIG_SPL_COMMON_INIT_DDR 3007 Set for common ddr init with serial presence detect in 3008 SPL binary. 3009 3010 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 3011 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 3012 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 3013 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 3014 CONFIG_SYS_NAND_ECCBYTES 3015 Defines the size and behavior of the NAND that SPL uses 3016 to read U-Boot 3017 3018 CONFIG_SPL_NAND_BOOT 3019 Add support NAND boot 3020 3021 CONFIG_SYS_NAND_U_BOOT_OFFS 3022 Location in NAND to read U-Boot from 3023 3024 CONFIG_SYS_NAND_U_BOOT_DST 3025 Location in memory to load U-Boot to 3026 3027 CONFIG_SYS_NAND_U_BOOT_SIZE 3028 Size of image to load 3029 3030 CONFIG_SYS_NAND_U_BOOT_START 3031 Entry point in loaded image to jump to 3032 3033 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 3034 Define this if you need to first read the OOB and then the 3035 data. This is used, for example, on davinci platforms. 3036 3037 CONFIG_SPL_OMAP3_ID_NAND 3038 Support for an OMAP3-specific set of functions to return the 3039 ID and MFR of the first attached NAND chip, if present. 3040 3041 CONFIG_SPL_RAM_DEVICE 3042 Support for running image already present in ram, in SPL binary 3043 3044 CONFIG_SPL_PAD_TO 3045 Image offset to which the SPL should be padded before appending 3046 the SPL payload. By default, this is defined as 3047 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3048 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3049 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3050 3051 CONFIG_SPL_TARGET 3052 Final target image containing SPL and payload. Some SPLs 3053 use an arch-specific makefile fragment instead, for 3054 example if more than one image needs to be produced. 3055 3056 CONFIG_FIT_SPL_PRINT 3057 Printing information about a FIT image adds quite a bit of 3058 code to SPL. So this is normally disabled in SPL. Use this 3059 option to re-enable it. This will affect the output of the 3060 bootm command when booting a FIT image. 3061 3062- TPL framework 3063 CONFIG_TPL 3064 Enable building of TPL globally. 3065 3066 CONFIG_TPL_PAD_TO 3067 Image offset to which the TPL should be padded before appending 3068 the TPL payload. By default, this is defined as 3069 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 3070 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 3071 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 3072 3073- Interrupt support (PPC): 3074 3075 There are common interrupt_init() and timer_interrupt() 3076 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 3077 for CPU specific initialization. interrupt_init_cpu() 3078 should set decrementer_count to appropriate value. If 3079 CPU resets decrementer automatically after interrupt 3080 (ppc4xx) it should set decrementer_count to zero. 3081 timer_interrupt() calls timer_interrupt_cpu() for CPU 3082 specific handling. If board has watchdog / status_led 3083 / other_activity_monitor it works automatically from 3084 general timer_interrupt(). 3085 3086 3087Board initialization settings: 3088------------------------------ 3089 3090During Initialization u-boot calls a number of board specific functions 3091to allow the preparation of board specific prerequisites, e.g. pin setup 3092before drivers are initialized. To enable these callbacks the 3093following configuration macros have to be defined. Currently this is 3094architecture specific, so please check arch/your_architecture/lib/board.c 3095typically in board_init_f() and board_init_r(). 3096 3097- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 3098- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 3099- CONFIG_BOARD_LATE_INIT: Call board_late_init() 3100- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 3101 3102Configuration Settings: 3103----------------------- 3104 3105- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 3106 Optionally it can be defined to support 64-bit memory commands. 3107 3108- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 3109 undefine this when you're short of memory. 3110 3111- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 3112 width of the commands listed in the 'help' command output. 3113 3114- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 3115 prompt for user input. 3116 3117- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 3118 3119- CONFIG_SYS_PBSIZE: Buffer size for Console output 3120 3121- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 3122 3123- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 3124 the application (usually a Linux kernel) when it is 3125 booted 3126 3127- CONFIG_SYS_BAUDRATE_TABLE: 3128 List of legal baudrate settings for this board. 3129 3130- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 3131 Begin and End addresses of the area used by the 3132 simple memory test. 3133 3134- CONFIG_SYS_ALT_MEMTEST: 3135 Enable an alternate, more extensive memory test. 3136 3137- CONFIG_SYS_MEMTEST_SCRATCH: 3138 Scratch address used by the alternate memory test 3139 You only need to set this if address zero isn't writeable 3140 3141- CONFIG_SYS_MEM_RESERVE_SECURE 3142 Only implemented for ARMv8 for now. 3143 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 3144 is substracted from total RAM and won't be reported to OS. 3145 This memory can be used as secure memory. A variable 3146 gd->arch.secure_ram is used to track the location. In systems 3147 the RAM base is not zero, or RAM is divided into banks, 3148 this variable needs to be recalcuated to get the address. 3149 3150- CONFIG_SYS_MEM_TOP_HIDE: 3151 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 3152 this specified memory area will get subtracted from the top 3153 (end) of RAM and won't get "touched" at all by U-Boot. By 3154 fixing up gd->ram_size the Linux kernel should gets passed 3155 the now "corrected" memory size and won't touch it either. 3156 This should work for arch/ppc and arch/powerpc. Only Linux 3157 board ports in arch/powerpc with bootwrapper support that 3158 recalculate the memory size from the SDRAM controller setup 3159 will have to get fixed in Linux additionally. 3160 3161 This option can be used as a workaround for the 440EPx/GRx 3162 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 3163 be touched. 3164 3165 WARNING: Please make sure that this value is a multiple of 3166 the Linux page size (normally 4k). If this is not the case, 3167 then the end address of the Linux memory will be located at a 3168 non page size aligned address and this could cause major 3169 problems. 3170 3171- CONFIG_SYS_LOADS_BAUD_CHANGE: 3172 Enable temporary baudrate change while serial download 3173 3174- CONFIG_SYS_SDRAM_BASE: 3175 Physical start address of SDRAM. _Must_ be 0 here. 3176 3177- CONFIG_SYS_FLASH_BASE: 3178 Physical start address of Flash memory. 3179 3180- CONFIG_SYS_MONITOR_BASE: 3181 Physical start address of boot monitor code (set by 3182 make config files to be same as the text base address 3183 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 3184 CONFIG_SYS_FLASH_BASE when booting from flash. 3185 3186- CONFIG_SYS_MONITOR_LEN: 3187 Size of memory reserved for monitor code, used to 3188 determine _at_compile_time_ (!) if the environment is 3189 embedded within the U-Boot image, or in a separate 3190 flash sector. 3191 3192- CONFIG_SYS_MALLOC_LEN: 3193 Size of DRAM reserved for malloc() use. 3194 3195- CONFIG_SYS_MALLOC_F_LEN 3196 Size of the malloc() pool for use before relocation. If 3197 this is defined, then a very simple malloc() implementation 3198 will become available before relocation. The address is just 3199 below the global data, and the stack is moved down to make 3200 space. 3201 3202 This feature allocates regions with increasing addresses 3203 within the region. calloc() is supported, but realloc() 3204 is not available. free() is supported but does nothing. 3205 The memory will be freed (or in fact just forgotten) when 3206 U-Boot relocates itself. 3207 3208- CONFIG_SYS_MALLOC_SIMPLE 3209 Provides a simple and small malloc() and calloc() for those 3210 boards which do not use the full malloc in SPL (which is 3211 enabled with CONFIG_SYS_SPL_MALLOC_START). 3212 3213- CONFIG_SYS_NONCACHED_MEMORY: 3214 Size of non-cached memory area. This area of memory will be 3215 typically located right below the malloc() area and mapped 3216 uncached in the MMU. This is useful for drivers that would 3217 otherwise require a lot of explicit cache maintenance. For 3218 some drivers it's also impossible to properly maintain the 3219 cache. For example if the regions that need to be flushed 3220 are not a multiple of the cache-line size, *and* padding 3221 cannot be allocated between the regions to align them (i.e. 3222 if the HW requires a contiguous array of regions, and the 3223 size of each region is not cache-aligned), then a flush of 3224 one region may result in overwriting data that hardware has 3225 written to another region in the same cache-line. This can 3226 happen for example in network drivers where descriptors for 3227 buffers are typically smaller than the CPU cache-line (e.g. 3228 16 bytes vs. 32 or 64 bytes). 3229 3230 Non-cached memory is only supported on 32-bit ARM at present. 3231 3232- CONFIG_SYS_BOOTM_LEN: 3233 Normally compressed uImages are limited to an 3234 uncompressed size of 8 MBytes. If this is not enough, 3235 you can define CONFIG_SYS_BOOTM_LEN in your board config file 3236 to adjust this setting to your needs. 3237 3238- CONFIG_SYS_BOOTMAPSZ: 3239 Maximum size of memory mapped by the startup code of 3240 the Linux kernel; all data that must be processed by 3241 the Linux kernel (bd_info, boot arguments, FDT blob if 3242 used) must be put below this limit, unless "bootm_low" 3243 environment variable is defined and non-zero. In such case 3244 all data for the Linux kernel must be between "bootm_low" 3245 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 3246 variable "bootm_mapsize" will override the value of 3247 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 3248 then the value in "bootm_size" will be used instead. 3249 3250- CONFIG_SYS_BOOT_RAMDISK_HIGH: 3251 Enable initrd_high functionality. If defined then the 3252 initrd_high feature is enabled and the bootm ramdisk subcommand 3253 is enabled. 3254 3255- CONFIG_SYS_BOOT_GET_CMDLINE: 3256 Enables allocating and saving kernel cmdline in space between 3257 "bootm_low" and "bootm_low" + BOOTMAPSZ. 3258 3259- CONFIG_SYS_BOOT_GET_KBD: 3260 Enables allocating and saving a kernel copy of the bd_info in 3261 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 3262 3263- CONFIG_SYS_MAX_FLASH_BANKS: 3264 Max number of Flash memory banks 3265 3266- CONFIG_SYS_MAX_FLASH_SECT: 3267 Max number of sectors on a Flash chip 3268 3269- CONFIG_SYS_FLASH_ERASE_TOUT: 3270 Timeout for Flash erase operations (in ms) 3271 3272- CONFIG_SYS_FLASH_WRITE_TOUT: 3273 Timeout for Flash write operations (in ms) 3274 3275- CONFIG_SYS_FLASH_LOCK_TOUT 3276 Timeout for Flash set sector lock bit operation (in ms) 3277 3278- CONFIG_SYS_FLASH_UNLOCK_TOUT 3279 Timeout for Flash clear lock bits operation (in ms) 3280 3281- CONFIG_SYS_FLASH_PROTECTION 3282 If defined, hardware flash sectors protection is used 3283 instead of U-Boot software protection. 3284 3285- CONFIG_SYS_DIRECT_FLASH_TFTP: 3286 3287 Enable TFTP transfers directly to flash memory; 3288 without this option such a download has to be 3289 performed in two steps: (1) download to RAM, and (2) 3290 copy from RAM to flash. 3291 3292 The two-step approach is usually more reliable, since 3293 you can check if the download worked before you erase 3294 the flash, but in some situations (when system RAM is 3295 too limited to allow for a temporary copy of the 3296 downloaded image) this option may be very useful. 3297 3298- CONFIG_SYS_FLASH_CFI: 3299 Define if the flash driver uses extra elements in the 3300 common flash structure for storing flash geometry. 3301 3302- CONFIG_FLASH_CFI_DRIVER 3303 This option also enables the building of the cfi_flash driver 3304 in the drivers directory 3305 3306- CONFIG_FLASH_CFI_MTD 3307 This option enables the building of the cfi_mtd driver 3308 in the drivers directory. The driver exports CFI flash 3309 to the MTD layer. 3310 3311- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3312 Use buffered writes to flash. 3313 3314- CONFIG_FLASH_SPANSION_S29WS_N 3315 s29ws-n MirrorBit flash has non-standard addresses for buffered 3316 write commands. 3317 3318- CONFIG_SYS_FLASH_QUIET_TEST 3319 If this option is defined, the common CFI flash doesn't 3320 print it's warning upon not recognized FLASH banks. This 3321 is useful, if some of the configured banks are only 3322 optionally available. 3323 3324- CONFIG_FLASH_SHOW_PROGRESS 3325 If defined (must be an integer), print out countdown 3326 digits and dots. Recommended value: 45 (9..1) for 80 3327 column displays, 15 (3..1) for 40 column displays. 3328 3329- CONFIG_FLASH_VERIFY 3330 If defined, the content of the flash (destination) is compared 3331 against the source after the write operation. An error message 3332 will be printed when the contents are not identical. 3333 Please note that this option is useless in nearly all cases, 3334 since such flash programming errors usually are detected earlier 3335 while unprotecting/erasing/programming. Please only enable 3336 this option if you really know what you are doing. 3337 3338- CONFIG_SYS_RX_ETH_BUFFER: 3339 Defines the number of Ethernet receive buffers. On some 3340 Ethernet controllers it is recommended to set this value 3341 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3342 buffers can be full shortly after enabling the interface 3343 on high Ethernet traffic. 3344 Defaults to 4 if not defined. 3345 3346- CONFIG_ENV_MAX_ENTRIES 3347 3348 Maximum number of entries in the hash table that is used 3349 internally to store the environment settings. The default 3350 setting is supposed to be generous and should work in most 3351 cases. This setting can be used to tune behaviour; see 3352 lib/hashtable.c for details. 3353 3354- CONFIG_ENV_FLAGS_LIST_DEFAULT 3355- CONFIG_ENV_FLAGS_LIST_STATIC 3356 Enable validation of the values given to environment variables when 3357 calling env set. Variables can be restricted to only decimal, 3358 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3359 the variables can also be restricted to IP address or MAC address. 3360 3361 The format of the list is: 3362 type_attribute = [s|d|x|b|i|m] 3363 access_attribute = [a|r|o|c] 3364 attributes = type_attribute[access_attribute] 3365 entry = variable_name[:attributes] 3366 list = entry[,list] 3367 3368 The type attributes are: 3369 s - String (default) 3370 d - Decimal 3371 x - Hexadecimal 3372 b - Boolean ([1yYtT|0nNfF]) 3373 i - IP address 3374 m - MAC address 3375 3376 The access attributes are: 3377 a - Any (default) 3378 r - Read-only 3379 o - Write-once 3380 c - Change-default 3381 3382 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3383 Define this to a list (string) to define the ".flags" 3384 environment variable in the default or embedded environment. 3385 3386 - CONFIG_ENV_FLAGS_LIST_STATIC 3387 Define this to a list (string) to define validation that 3388 should be done if an entry is not found in the ".flags" 3389 environment variable. To override a setting in the static 3390 list, simply add an entry for the same variable name to the 3391 ".flags" variable. 3392 3393 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3394 regular expression. This allows multiple variables to define the same 3395 flags without explicitly listing them for each variable. 3396 3397- CONFIG_ENV_ACCESS_IGNORE_FORCE 3398 If defined, don't allow the -f switch to env set override variable 3399 access flags. 3400 3401- CONFIG_USE_STDINT 3402 If stdint.h is available with your toolchain you can define this 3403 option to enable it. You can provide option 'USE_STDINT=1' when 3404 building U-Boot to enable this. 3405 3406The following definitions that deal with the placement and management 3407of environment data (variable area); in general, we support the 3408following configurations: 3409 3410- CONFIG_BUILD_ENVCRC: 3411 3412 Builds up envcrc with the target environment so that external utils 3413 may easily extract it and embed it in final U-Boot images. 3414 3415- CONFIG_ENV_IS_IN_FLASH: 3416 3417 Define this if the environment is in flash memory. 3418 3419 a) The environment occupies one whole flash sector, which is 3420 "embedded" in the text segment with the U-Boot code. This 3421 happens usually with "bottom boot sector" or "top boot 3422 sector" type flash chips, which have several smaller 3423 sectors at the start or the end. For instance, such a 3424 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In 3425 such a case you would place the environment in one of the 3426 4 kB sectors - with U-Boot code before and after it. With 3427 "top boot sector" type flash chips, you would put the 3428 environment in one of the last sectors, leaving a gap 3429 between U-Boot and the environment. 3430 3431 - CONFIG_ENV_OFFSET: 3432 3433 Offset of environment data (variable area) to the 3434 beginning of flash memory; for instance, with bottom boot 3435 type flash chips the second sector can be used: the offset 3436 for this sector is given here. 3437 3438 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE. 3439 3440 - CONFIG_ENV_ADDR: 3441 3442 This is just another way to specify the start address of 3443 the flash sector containing the environment (instead of 3444 CONFIG_ENV_OFFSET). 3445 3446 - CONFIG_ENV_SECT_SIZE: 3447 3448 Size of the sector containing the environment. 3449 3450 3451 b) Sometimes flash chips have few, equal sized, BIG sectors. 3452 In such a case you don't want to spend a whole sector for 3453 the environment. 3454 3455 - CONFIG_ENV_SIZE: 3456 3457 If you use this in combination with CONFIG_ENV_IS_IN_FLASH 3458 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part 3459 of this flash sector for the environment. This saves 3460 memory for the RAM copy of the environment. 3461 3462 It may also save flash memory if you decide to use this 3463 when your environment is "embedded" within U-Boot code, 3464 since then the remainder of the flash sector could be used 3465 for U-Boot code. It should be pointed out that this is 3466 STRONGLY DISCOURAGED from a robustness point of view: 3467 updating the environment in flash makes it always 3468 necessary to erase the WHOLE sector. If something goes 3469 wrong before the contents has been restored from a copy in 3470 RAM, your target system will be dead. 3471 3472 - CONFIG_ENV_ADDR_REDUND 3473 CONFIG_ENV_SIZE_REDUND 3474 3475 These settings describe a second storage area used to hold 3476 a redundant copy of the environment data, so that there is 3477 a valid backup copy in case there is a power failure during 3478 a "saveenv" operation. 3479 3480BE CAREFUL! Any changes to the flash layout, and some changes to the 3481source code will make it necessary to adapt <board>/u-boot.lds* 3482accordingly! 3483 3484 3485- CONFIG_ENV_IS_IN_NVRAM: 3486 3487 Define this if you have some non-volatile memory device 3488 (NVRAM, battery buffered SRAM) which you want to use for the 3489 environment. 3490 3491 - CONFIG_ENV_ADDR: 3492 - CONFIG_ENV_SIZE: 3493 3494 These two #defines are used to determine the memory area you 3495 want to use for environment. It is assumed that this memory 3496 can just be read and written to, without any special 3497 provision. 3498 3499BE CAREFUL! The first access to the environment happens quite early 3500in U-Boot initialization (when we try to get the setting of for the 3501console baudrate). You *MUST* have mapped your NVRAM area then, or 3502U-Boot will hang. 3503 3504Please note that even with NVRAM we still use a copy of the 3505environment in RAM: we could work on NVRAM directly, but we want to 3506keep settings there always unmodified except somebody uses "saveenv" 3507to save the current settings. 3508 3509 3510- CONFIG_ENV_IS_IN_EEPROM: 3511 3512 Use this if you have an EEPROM or similar serial access 3513 device and a driver for it. 3514 3515 - CONFIG_ENV_OFFSET: 3516 - CONFIG_ENV_SIZE: 3517 3518 These two #defines specify the offset and size of the 3519 environment area within the total memory of your EEPROM. 3520 3521 - CONFIG_SYS_I2C_EEPROM_ADDR: 3522 If defined, specified the chip address of the EEPROM device. 3523 The default address is zero. 3524 3525 - CONFIG_SYS_I2C_EEPROM_BUS: 3526 If defined, specified the i2c bus of the EEPROM device. 3527 3528 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS: 3529 If defined, the number of bits used to address bytes in a 3530 single page in the EEPROM device. A 64 byte page, for example 3531 would require six bits. 3532 3533 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS: 3534 If defined, the number of milliseconds to delay between 3535 page writes. The default is zero milliseconds. 3536 3537 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN: 3538 The length in bytes of the EEPROM memory array address. Note 3539 that this is NOT the chip address length! 3540 3541 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW: 3542 EEPROM chips that implement "address overflow" are ones 3543 like Catalyst 24WC04/08/16 which has 9/10/11 bits of 3544 address and the extra bits end up in the "chip address" bit 3545 slots. This makes a 24WC08 (1Kbyte) chip look like four 256 3546 byte chips. 3547 3548 Note that we consider the length of the address field to 3549 still be one byte because the extra address bits are hidden 3550 in the chip address. 3551 3552 - CONFIG_SYS_EEPROM_SIZE: 3553 The size in bytes of the EEPROM device. 3554 3555 - CONFIG_ENV_EEPROM_IS_ON_I2C 3556 define this, if you have I2C and SPI activated, and your 3557 EEPROM, which holds the environment, is on the I2C bus. 3558 3559 - CONFIG_I2C_ENV_EEPROM_BUS 3560 if you have an Environment on an EEPROM reached over 3561 I2C muxes, you can define here, how to reach this 3562 EEPROM. For example: 3563 3564 #define CONFIG_I2C_ENV_EEPROM_BUS 1 3565 3566 EEPROM which holds the environment, is reached over 3567 a pca9547 i2c mux with address 0x70, channel 3. 3568 3569- CONFIG_ENV_IS_IN_DATAFLASH: 3570 3571 Define this if you have a DataFlash memory device which you 3572 want to use for the environment. 3573 3574 - CONFIG_ENV_OFFSET: 3575 - CONFIG_ENV_ADDR: 3576 - CONFIG_ENV_SIZE: 3577 3578 These three #defines specify the offset and size of the 3579 environment area within the total memory of your DataFlash placed 3580 at the specified address. 3581 3582- CONFIG_ENV_IS_IN_SPI_FLASH: 3583 3584 Define this if you have a SPI Flash memory device which you 3585 want to use for the environment. 3586 3587 - CONFIG_ENV_OFFSET: 3588 - CONFIG_ENV_SIZE: 3589 3590 These two #defines specify the offset and size of the 3591 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be 3592 aligned to an erase sector boundary. 3593 3594 - CONFIG_ENV_SECT_SIZE: 3595 3596 Define the SPI flash's sector size. 3597 3598 - CONFIG_ENV_OFFSET_REDUND (optional): 3599 3600 This setting describes a second storage area of CONFIG_ENV_SIZE 3601 size used to hold a redundant copy of the environment data, so 3602 that there is a valid backup copy in case there is a power failure 3603 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be 3604 aligned to an erase sector boundary. 3605 3606 - CONFIG_ENV_SPI_BUS (optional): 3607 - CONFIG_ENV_SPI_CS (optional): 3608 3609 Define the SPI bus and chip select. If not defined they will be 0. 3610 3611 - CONFIG_ENV_SPI_MAX_HZ (optional): 3612 3613 Define the SPI max work clock. If not defined then use 1MHz. 3614 3615 - CONFIG_ENV_SPI_MODE (optional): 3616 3617 Define the SPI work mode. If not defined then use SPI_MODE_3. 3618 3619- CONFIG_ENV_IS_IN_REMOTE: 3620 3621 Define this if you have a remote memory space which you 3622 want to use for the local device's environment. 3623 3624 - CONFIG_ENV_ADDR: 3625 - CONFIG_ENV_SIZE: 3626 3627 These two #defines specify the address and size of the 3628 environment area within the remote memory space. The 3629 local device can get the environment from remote memory 3630 space by SRIO or PCIE links. 3631 3632BE CAREFUL! For some special cases, the local device can not use 3633"saveenv" command. For example, the local device will get the 3634environment stored in a remote NOR flash by SRIO or PCIE link, 3635but it can not erase, write this NOR flash by SRIO or PCIE interface. 3636 3637- CONFIG_NAND_ENV_DST 3638 3639 Defines address in RAM to which the nand_spl code should copy the 3640 environment. If redundant environment is used, it will be copied to 3641 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3642 3643- CONFIG_ENV_IS_IN_FAT: 3644 Define this if you want to use the FAT file system for the environment. 3645 3646 - FAT_ENV_INTERFACE: 3647 3648 Define this to a string that is the name of the block device. 3649 3650 - FAT_ENV_DEVICE_AND_PART: 3651 3652 Define this to a string to specify the partition of the device. It can 3653 be as following: 3654 3655 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1) 3656 - "D:P": device D partition P. Error occurs if device D has no 3657 partition table. 3658 - "D:0": device D. 3659 - "D" or "D:": device D partition 1 if device D has partition 3660 table, or the whole device D if has no partition 3661 table. 3662 - "D:auto": first partition in device D with bootable flag set. 3663 If none, first valid partition in device D. If no 3664 partition table then means device D. 3665 3666 - FAT_ENV_FILE: 3667 3668 It's a string of the FAT file name. This file use to store the 3669 environment. 3670 3671 - CONFIG_FAT_WRITE: 3672 This must be enabled. Otherwise it cannot save the environment file. 3673 3674Please note that the environment is read-only until the monitor 3675has been relocated to RAM and a RAM copy of the environment has been 3676created; also, when using EEPROM you will have to use getenv_f() 3677until then to read environment variables. 3678 3679The environment is protected by a CRC32 checksum. Before the monitor 3680is relocated into RAM, as a result of a bad CRC you will be working 3681with the compiled-in default environment - *silently*!!! [This is 3682necessary, because the first environment variable we need is the 3683"baudrate" setting for the console - if we have a bad CRC, we don't 3684have any device yet where we could complain.] 3685 3686Note: once the monitor has been relocated, then it will complain if 3687the default environment is used; a new CRC is computed as soon as you 3688use the "saveenv" command to store a valid environment. 3689 3690- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3691 Echo the inverted Ethernet link state to the fault LED. 3692 3693 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3694 also needs to be defined. 3695 3696- CONFIG_SYS_FAULT_MII_ADDR: 3697 MII address of the PHY to check for the Ethernet link state. 3698 3699- CONFIG_NS16550_MIN_FUNCTIONS: 3700 Define this if you desire to only have use of the NS16550_init 3701 and NS16550_putc functions for the serial driver located at 3702 drivers/serial/ns16550.c. This option is useful for saving 3703 space for already greatly restricted images, including but not 3704 limited to NAND_SPL configurations. 3705 3706- CONFIG_DISPLAY_BOARDINFO 3707 Display information about the board that U-Boot is running on 3708 when U-Boot starts up. The board function checkboard() is called 3709 to do this. 3710 3711- CONFIG_DISPLAY_BOARDINFO_LATE 3712 Similar to the previous option, but display this information 3713 later, once stdio is running and output goes to the LCD, if 3714 present. 3715 3716- CONFIG_BOARD_SIZE_LIMIT: 3717 Maximum size of the U-Boot image. When defined, the 3718 build system checks that the actual size does not 3719 exceed it. 3720 3721Low Level (hardware related) configuration options: 3722--------------------------------------------------- 3723 3724- CONFIG_SYS_CACHELINE_SIZE: 3725 Cache Line Size of the CPU. 3726 3727- CONFIG_SYS_CCSRBAR_DEFAULT: 3728 Default (power-on reset) physical address of CCSR on Freescale 3729 PowerPC SOCs. 3730 3731- CONFIG_SYS_CCSRBAR: 3732 Virtual address of CCSR. On a 32-bit build, this is typically 3733 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3734 3735- CONFIG_SYS_CCSRBAR_PHYS: 3736 Physical address of CCSR. CCSR can be relocated to a new 3737 physical address, if desired. In this case, this macro should 3738 be set to that address. Otherwise, it should be set to the 3739 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3740 is typically relocated on 36-bit builds. It is recommended 3741 that this macro be defined via the _HIGH and _LOW macros: 3742 3743 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3744 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3745 3746- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3747 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3748 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3749 used in assembly code, so it must not contain typecasts or 3750 integer size suffixes (e.g. "ULL"). 3751 3752- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3753 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3754 used in assembly code, so it must not contain typecasts or 3755 integer size suffixes (e.g. "ULL"). 3756 3757- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3758 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3759 forced to a value that ensures that CCSR is not relocated. 3760 3761- Floppy Disk Support: 3762 CONFIG_SYS_FDC_DRIVE_NUMBER 3763 3764 the default drive number (default value 0) 3765 3766 CONFIG_SYS_ISA_IO_STRIDE 3767 3768 defines the spacing between FDC chipset registers 3769 (default value 1) 3770 3771 CONFIG_SYS_ISA_IO_OFFSET 3772 3773 defines the offset of register from address. It 3774 depends on which part of the data bus is connected to 3775 the FDC chipset. (default value 0) 3776 3777 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3778 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3779 default value. 3780 3781 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3782 fdc_hw_init() is called at the beginning of the FDC 3783 setup. fdc_hw_init() must be provided by the board 3784 source code. It is used to make hardware-dependent 3785 initializations. 3786 3787- CONFIG_IDE_AHB: 3788 Most IDE controllers were designed to be connected with PCI 3789 interface. Only few of them were designed for AHB interface. 3790 When software is doing ATA command and data transfer to 3791 IDE devices through IDE-AHB controller, some additional 3792 registers accessing to these kind of IDE-AHB controller 3793 is required. 3794 3795- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3796 DO NOT CHANGE unless you know exactly what you're 3797 doing! (11-4) [MPC8xx systems only] 3798 3799- CONFIG_SYS_INIT_RAM_ADDR: 3800 3801 Start address of memory area that can be used for 3802 initial data and stack; please note that this must be 3803 writable memory that is working WITHOUT special 3804 initialization, i. e. you CANNOT use normal RAM which 3805 will become available only after programming the 3806 memory controller and running certain initialization 3807 sequences. 3808 3809 U-Boot uses the following memory types: 3810 - MPC8xx: IMMR (internal memory of the CPU) 3811 3812- CONFIG_SYS_GBL_DATA_OFFSET: 3813 3814 Offset of the initial data structure in the memory 3815 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3816 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3817 data is located at the end of the available space 3818 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3819 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3820 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3821 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3822 3823 Note: 3824 On the MPC824X (or other systems that use the data 3825 cache for initial memory) the address chosen for 3826 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3827 point to an otherwise UNUSED address space between 3828 the top of RAM and the start of the PCI space. 3829 3830- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3831 3832- CONFIG_SYS_OR_TIMING_SDRAM: 3833 SDRAM timing 3834 3835- CONFIG_SYS_MAMR_PTA: 3836 periodic timer for refresh 3837 3838- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3839 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3840 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3841 CONFIG_SYS_BR1_PRELIM: 3842 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3843 3844- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3845 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3846 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3847 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3848 3849- CONFIG_PCI_ENUM_ONLY 3850 Only scan through and get the devices on the buses. 3851 Don't do any setup work, presumably because someone or 3852 something has already done it, and we don't need to do it 3853 a second time. Useful for platforms that are pre-booted 3854 by coreboot or similar. 3855 3856- CONFIG_PCI_INDIRECT_BRIDGE: 3857 Enable support for indirect PCI bridges. 3858 3859- CONFIG_SYS_SRIO: 3860 Chip has SRIO or not 3861 3862- CONFIG_SRIO1: 3863 Board has SRIO 1 port available 3864 3865- CONFIG_SRIO2: 3866 Board has SRIO 2 port available 3867 3868- CONFIG_SRIO_PCIE_BOOT_MASTER 3869 Board can support master function for Boot from SRIO and PCIE 3870 3871- CONFIG_SYS_SRIOn_MEM_VIRT: 3872 Virtual Address of SRIO port 'n' memory region 3873 3874- CONFIG_SYS_SRIOn_MEM_PHYS: 3875 Physical Address of SRIO port 'n' memory region 3876 3877- CONFIG_SYS_SRIOn_MEM_SIZE: 3878 Size of SRIO port 'n' memory region 3879 3880- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3881 Defined to tell the NAND controller that the NAND chip is using 3882 a 16 bit bus. 3883 Not all NAND drivers use this symbol. 3884 Example of drivers that use it: 3885 - drivers/mtd/nand/ndfc.c 3886 - drivers/mtd/nand/mxc_nand.c 3887 3888- CONFIG_SYS_NDFC_EBC0_CFG 3889 Sets the EBC0_CFG register for the NDFC. If not defined 3890 a default value will be used. 3891 3892- CONFIG_SPD_EEPROM 3893 Get DDR timing information from an I2C EEPROM. Common 3894 with pluggable memory modules such as SODIMMs 3895 3896 SPD_EEPROM_ADDRESS 3897 I2C address of the SPD EEPROM 3898 3899- CONFIG_SYS_SPD_BUS_NUM 3900 If SPD EEPROM is on an I2C bus other than the first 3901 one, specify here. Note that the value must resolve 3902 to something your driver can deal with. 3903 3904- CONFIG_SYS_DDR_RAW_TIMING 3905 Get DDR timing information from other than SPD. Common with 3906 soldered DDR chips onboard without SPD. DDR raw timing 3907 parameters are extracted from datasheet and hard-coded into 3908 header files or board specific files. 3909 3910- CONFIG_FSL_DDR_INTERACTIVE 3911 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3912 3913- CONFIG_FSL_DDR_SYNC_REFRESH 3914 Enable sync of refresh for multiple controllers. 3915 3916- CONFIG_FSL_DDR_BIST 3917 Enable built-in memory test for Freescale DDR controllers. 3918 3919- CONFIG_SYS_83XX_DDR_USES_CS0 3920 Only for 83xx systems. If specified, then DDR should 3921 be configured using CS0 and CS1 instead of CS2 and CS3. 3922 3923- CONFIG_RMII 3924 Enable RMII mode for all FECs. 3925 Note that this is a global option, we can't 3926 have one FEC in standard MII mode and another in RMII mode. 3927 3928- CONFIG_CRC32_VERIFY 3929 Add a verify option to the crc32 command. 3930 The syntax is: 3931 3932 => crc32 -v <address> <count> <crc32> 3933 3934 Where address/count indicate a memory area 3935 and crc32 is the correct crc32 which the 3936 area should have. 3937 3938- CONFIG_LOOPW 3939 Add the "loopw" memory command. This only takes effect if 3940 the memory commands are activated globally (CONFIG_CMD_MEM). 3941 3942- CONFIG_MX_CYCLIC 3943 Add the "mdc" and "mwc" memory commands. These are cyclic 3944 "md/mw" commands. 3945 Examples: 3946 3947 => mdc.b 10 4 500 3948 This command will print 4 bytes (10,11,12,13) each 500 ms. 3949 3950 => mwc.l 100 12345678 10 3951 This command will write 12345678 to address 100 all 10 ms. 3952 3953 This only takes effect if the memory commands are activated 3954 globally (CONFIG_CMD_MEM). 3955 3956- CONFIG_SKIP_LOWLEVEL_INIT 3957 [ARM, NDS32, MIPS only] If this variable is defined, then certain 3958 low level initializations (like setting up the memory 3959 controller) are omitted and/or U-Boot does not 3960 relocate itself into RAM. 3961 3962 Normally this variable MUST NOT be defined. The only 3963 exception is when U-Boot is loaded (to RAM) by some 3964 other boot loader or by a debugger which performs 3965 these initializations itself. 3966 3967- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3968 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3969 to be skipped. The normal CP15 init (such as enabling the 3970 instruction cache) is still performed. 3971 3972- CONFIG_SPL_BUILD 3973 Modifies the behaviour of start.S when compiling a loader 3974 that is executed before the actual U-Boot. E.g. when 3975 compiling a NAND SPL. 3976 3977- CONFIG_TPL_BUILD 3978 Modifies the behaviour of start.S when compiling a loader 3979 that is executed after the SPL and before the actual U-Boot. 3980 It is loaded by the SPL. 3981 3982- CONFIG_SYS_MPC85XX_NO_RESETVEC 3983 Only for 85xx systems. If this variable is specified, the section 3984 .resetvec is not kept and the section .bootpg is placed in the 3985 previous 4k of the .text section. 3986 3987- CONFIG_ARCH_MAP_SYSMEM 3988 Generally U-Boot (and in particular the md command) uses 3989 effective address. It is therefore not necessary to regard 3990 U-Boot address as virtual addresses that need to be translated 3991 to physical addresses. However, sandbox requires this, since 3992 it maintains its own little RAM buffer which contains all 3993 addressable memory. This option causes some memory accesses 3994 to be mapped through map_sysmem() / unmap_sysmem(). 3995 3996- CONFIG_X86_RESET_VECTOR 3997 If defined, the x86 reset vector code is included. This is not 3998 needed when U-Boot is running from Coreboot. 3999 4000- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 4001 Enables the RTC32K OSC on AM33xx based plattforms 4002 4003- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 4004 Option to disable subpage write in NAND driver 4005 driver that uses this: 4006 drivers/mtd/nand/davinci_nand.c 4007 4008Freescale QE/FMAN Firmware Support: 4009----------------------------------- 4010 4011The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 4012loading of "firmware", which is encoded in the QE firmware binary format. 4013This firmware often needs to be loaded during U-Boot booting, so macros 4014are used to identify the storage device (NOR flash, SPI, etc) and the address 4015within that device. 4016 4017- CONFIG_SYS_FMAN_FW_ADDR 4018 The address in the storage device where the FMAN microcode is located. The 4019 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4020 is also specified. 4021 4022- CONFIG_SYS_QE_FW_ADDR 4023 The address in the storage device where the QE microcode is located. The 4024 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 4025 is also specified. 4026 4027- CONFIG_SYS_QE_FMAN_FW_LENGTH 4028 The maximum possible size of the firmware. The firmware binary format 4029 has a field that specifies the actual size of the firmware, but it 4030 might not be possible to read any part of the firmware unless some 4031 local storage is allocated to hold the entire firmware first. 4032 4033- CONFIG_SYS_QE_FMAN_FW_IN_NOR 4034 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 4035 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 4036 virtual address in NOR flash. 4037 4038- CONFIG_SYS_QE_FMAN_FW_IN_NAND 4039 Specifies that QE/FMAN firmware is located in NAND flash. 4040 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 4041 4042- CONFIG_SYS_QE_FMAN_FW_IN_MMC 4043 Specifies that QE/FMAN firmware is located on the primary SD/MMC 4044 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 4045 4046- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 4047 Specifies that QE/FMAN firmware is located in the remote (master) 4048 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 4049 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 4050 window->master inbound window->master LAW->the ucode address in 4051 master's memory space. 4052 4053Freescale Layerscape Management Complex Firmware Support: 4054--------------------------------------------------------- 4055The Freescale Layerscape Management Complex (MC) supports the loading of 4056"firmware". 4057This firmware often needs to be loaded during U-Boot booting, so macros 4058are used to identify the storage device (NOR flash, SPI, etc) and the address 4059within that device. 4060 4061- CONFIG_FSL_MC_ENET 4062 Enable the MC driver for Layerscape SoCs. 4063 4064Freescale Layerscape Debug Server Support: 4065------------------------------------------- 4066The Freescale Layerscape Debug Server Support supports the loading of 4067"Debug Server firmware" and triggering SP boot-rom. 4068This firmware often needs to be loaded during U-Boot booting. 4069 4070- CONFIG_SYS_MC_RSV_MEM_ALIGN 4071 Define alignment of reserved memory MC requires 4072 4073Reproducible builds 4074------------------- 4075 4076In order to achieve reproducible builds, timestamps used in the U-Boot build 4077process have to be set to a fixed value. 4078 4079This is done using the SOURCE_DATE_EPOCH environment variable. 4080SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 4081option for U-Boot or an environment variable in U-Boot. 4082 4083SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 4084 4085Building the Software: 4086====================== 4087 4088Building U-Boot has been tested in several native build environments 4089and in many different cross environments. Of course we cannot support 4090all possibly existing versions of cross development tools in all 4091(potentially obsolete) versions. In case of tool chain problems we 4092recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 4093which is extensively used to build and test U-Boot. 4094 4095If you are not using a native environment, it is assumed that you 4096have GNU cross compiling tools available in your path. In this case, 4097you must set the environment variable CROSS_COMPILE in your shell. 4098Note that no changes to the Makefile or any other source files are 4099necessary. For example using the ELDK on a 4xx CPU, please enter: 4100 4101 $ CROSS_COMPILE=ppc_4xx- 4102 $ export CROSS_COMPILE 4103 4104Note: If you wish to generate Windows versions of the utilities in 4105 the tools directory you can use the MinGW toolchain 4106 (http://www.mingw.org). Set your HOST tools to the MinGW 4107 toolchain and execute 'make tools'. For example: 4108 4109 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 4110 4111 Binaries such as tools/mkimage.exe will be created which can 4112 be executed on computers running Windows. 4113 4114U-Boot is intended to be simple to build. After installing the 4115sources you must configure U-Boot for one specific board type. This 4116is done by typing: 4117 4118 make NAME_defconfig 4119 4120where "NAME_defconfig" is the name of one of the existing configu- 4121rations; see boards.cfg for supported names. 4122 4123Note: for some board special configuration names may exist; check if 4124 additional information is available from the board vendor; for 4125 instance, the TQM823L systems are available without (standard) 4126 or with LCD support. You can select such additional "features" 4127 when choosing the configuration, i. e. 4128 4129 make TQM823L_defconfig 4130 - will configure for a plain TQM823L, i. e. no LCD support 4131 4132 make TQM823L_LCD_defconfig 4133 - will configure for a TQM823L with U-Boot console on LCD 4134 4135 etc. 4136 4137 4138Finally, type "make all", and you should get some working U-Boot 4139images ready for download to / installation on your system: 4140 4141- "u-boot.bin" is a raw binary image 4142- "u-boot" is an image in ELF binary format 4143- "u-boot.srec" is in Motorola S-Record format 4144 4145By default the build is performed locally and the objects are saved 4146in the source directory. One of the two methods can be used to change 4147this behavior and build U-Boot to some external directory: 4148 41491. Add O= to the make command line invocations: 4150 4151 make O=/tmp/build distclean 4152 make O=/tmp/build NAME_defconfig 4153 make O=/tmp/build all 4154 41552. Set environment variable KBUILD_OUTPUT to point to the desired location: 4156 4157 export KBUILD_OUTPUT=/tmp/build 4158 make distclean 4159 make NAME_defconfig 4160 make all 4161 4162Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 4163variable. 4164 4165 4166Please be aware that the Makefiles assume you are using GNU make, so 4167for instance on NetBSD you might need to use "gmake" instead of 4168native "make". 4169 4170 4171If the system board that you have is not listed, then you will need 4172to port U-Boot to your hardware platform. To do this, follow these 4173steps: 4174 41751. Create a new directory to hold your board specific code. Add any 4176 files you need. In your board directory, you will need at least 4177 the "Makefile" and a "<board>.c". 41782. Create a new configuration file "include/configs/<board>.h" for 4179 your board. 41803. If you're porting U-Boot to a new CPU, then also create a new 4181 directory to hold your CPU specific code. Add any files you need. 41824. Run "make <board>_defconfig" with your new name. 41835. Type "make", and you should get a working "u-boot.srec" file 4184 to be installed on your target system. 41856. Debug and solve any problems that might arise. 4186 [Of course, this last step is much harder than it sounds.] 4187 4188 4189Testing of U-Boot Modifications, Ports to New Hardware, etc.: 4190============================================================== 4191 4192If you have modified U-Boot sources (for instance added a new board 4193or support for new devices, a new CPU, etc.) you are expected to 4194provide feedback to the other developers. The feedback normally takes 4195the form of a "patch", i. e. a context diff against a certain (latest 4196official or latest in the git repository) version of U-Boot sources. 4197 4198But before you submit such a patch, please verify that your modifi- 4199cation did not break existing code. At least make sure that *ALL* of 4200the supported boards compile WITHOUT ANY compiler warnings. To do so, 4201just run the buildman script (tools/buildman/buildman), which will 4202configure and build U-Boot for ALL supported system. Be warned, this 4203will take a while. Please see the buildman README, or run 'buildman -H' 4204for documentation. 4205 4206 4207See also "U-Boot Porting Guide" below. 4208 4209 4210Monitor Commands - Overview: 4211============================ 4212 4213go - start application at address 'addr' 4214run - run commands in an environment variable 4215bootm - boot application image from memory 4216bootp - boot image via network using BootP/TFTP protocol 4217bootz - boot zImage from memory 4218tftpboot- boot image via network using TFTP protocol 4219 and env variables "ipaddr" and "serverip" 4220 (and eventually "gatewayip") 4221tftpput - upload a file via network using TFTP protocol 4222rarpboot- boot image via network using RARP/TFTP protocol 4223diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 4224loads - load S-Record file over serial line 4225loadb - load binary file over serial line (kermit mode) 4226md - memory display 4227mm - memory modify (auto-incrementing) 4228nm - memory modify (constant address) 4229mw - memory write (fill) 4230cp - memory copy 4231cmp - memory compare 4232crc32 - checksum calculation 4233i2c - I2C sub-system 4234sspi - SPI utility commands 4235base - print or set address offset 4236printenv- print environment variables 4237setenv - set environment variables 4238saveenv - save environment variables to persistent storage 4239protect - enable or disable FLASH write protection 4240erase - erase FLASH memory 4241flinfo - print FLASH memory information 4242nand - NAND memory operations (see doc/README.nand) 4243bdinfo - print Board Info structure 4244iminfo - print header information for application image 4245coninfo - print console devices and informations 4246ide - IDE sub-system 4247loop - infinite loop on address range 4248loopw - infinite write loop on address range 4249mtest - simple RAM test 4250icache - enable or disable instruction cache 4251dcache - enable or disable data cache 4252reset - Perform RESET of the CPU 4253echo - echo args to console 4254version - print monitor version 4255help - print online help 4256? - alias for 'help' 4257 4258 4259Monitor Commands - Detailed Description: 4260======================================== 4261 4262TODO. 4263 4264For now: just type "help <command>". 4265 4266 4267Environment Variables: 4268====================== 4269 4270U-Boot supports user configuration using Environment Variables which 4271can be made persistent by saving to Flash memory. 4272 4273Environment Variables are set using "setenv", printed using 4274"printenv", and saved to Flash using "saveenv". Using "setenv" 4275without a value can be used to delete a variable from the 4276environment. As long as you don't save the environment you are 4277working with an in-memory copy. In case the Flash area containing the 4278environment is erased by accident, a default environment is provided. 4279 4280Some configuration options can be set using Environment Variables. 4281 4282List of environment variables (most likely not complete): 4283 4284 baudrate - see CONFIG_BAUDRATE 4285 4286 bootdelay - see CONFIG_BOOTDELAY 4287 4288 bootcmd - see CONFIG_BOOTCOMMAND 4289 4290 bootargs - Boot arguments when booting an RTOS image 4291 4292 bootfile - Name of the image to load with TFTP 4293 4294 bootm_low - Memory range available for image processing in the bootm 4295 command can be restricted. This variable is given as 4296 a hexadecimal number and defines lowest address allowed 4297 for use by the bootm command. See also "bootm_size" 4298 environment variable. Address defined by "bootm_low" is 4299 also the base of the initial memory mapping for the Linux 4300 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 4301 bootm_mapsize. 4302 4303 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 4304 This variable is given as a hexadecimal number and it 4305 defines the size of the memory region starting at base 4306 address bootm_low that is accessible by the Linux kernel 4307 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 4308 as the default value if it is defined, and bootm_size is 4309 used otherwise. 4310 4311 bootm_size - Memory range available for image processing in the bootm 4312 command can be restricted. This variable is given as 4313 a hexadecimal number and defines the size of the region 4314 allowed for use by the bootm command. See also "bootm_low" 4315 environment variable. 4316 4317 updatefile - Location of the software update file on a TFTP server, used 4318 by the automatic software update feature. Please refer to 4319 documentation in doc/README.update for more details. 4320 4321 autoload - if set to "no" (any string beginning with 'n'), 4322 "bootp" will just load perform a lookup of the 4323 configuration from the BOOTP server, but not try to 4324 load any image using TFTP 4325 4326 autostart - if set to "yes", an image loaded using the "bootp", 4327 "rarpboot", "tftpboot" or "diskboot" commands will 4328 be automatically started (by internally calling 4329 "bootm") 4330 4331 If set to "no", a standalone image passed to the 4332 "bootm" command will be copied to the load address 4333 (and eventually uncompressed), but NOT be started. 4334 This can be used to load and uncompress arbitrary 4335 data. 4336 4337 fdt_high - if set this restricts the maximum address that the 4338 flattened device tree will be copied into upon boot. 4339 For example, if you have a system with 1 GB memory 4340 at physical address 0x10000000, while Linux kernel 4341 only recognizes the first 704 MB as low memory, you 4342 may need to set fdt_high as 0x3C000000 to have the 4343 device tree blob be copied to the maximum address 4344 of the 704 MB low memory, so that Linux kernel can 4345 access it during the boot procedure. 4346 4347 If this is set to the special value 0xFFFFFFFF then 4348 the fdt will not be copied at all on boot. For this 4349 to work it must reside in writable memory, have 4350 sufficient padding on the end of it for u-boot to 4351 add the information it needs into it, and the memory 4352 must be accessible by the kernel. 4353 4354 fdtcontroladdr- if set this is the address of the control flattened 4355 device tree used by U-Boot when CONFIG_OF_CONTROL is 4356 defined. 4357 4358 i2cfast - (PPC405GP|PPC405EP only) 4359 if set to 'y' configures Linux I2C driver for fast 4360 mode (400kHZ). This environment variable is used in 4361 initialization code. So, for changes to be effective 4362 it must be saved and board must be reset. 4363 4364 initrd_high - restrict positioning of initrd images: 4365 If this variable is not set, initrd images will be 4366 copied to the highest possible address in RAM; this 4367 is usually what you want since it allows for 4368 maximum initrd size. If for some reason you want to 4369 make sure that the initrd image is loaded below the 4370 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 4371 variable to a value of "no" or "off" or "0". 4372 Alternatively, you can set it to a maximum upper 4373 address to use (U-Boot will still check that it 4374 does not overwrite the U-Boot stack and data). 4375 4376 For instance, when you have a system with 16 MB 4377 RAM, and want to reserve 4 MB from use by Linux, 4378 you can do this by adding "mem=12M" to the value of 4379 the "bootargs" variable. However, now you must make 4380 sure that the initrd image is placed in the first 4381 12 MB as well - this can be done with 4382 4383 setenv initrd_high 00c00000 4384 4385 If you set initrd_high to 0xFFFFFFFF, this is an 4386 indication to U-Boot that all addresses are legal 4387 for the Linux kernel, including addresses in flash 4388 memory. In this case U-Boot will NOT COPY the 4389 ramdisk at all. This may be useful to reduce the 4390 boot time on your system, but requires that this 4391 feature is supported by your Linux kernel. 4392 4393 ipaddr - IP address; needed for tftpboot command 4394 4395 loadaddr - Default load address for commands like "bootp", 4396 "rarpboot", "tftpboot", "loadb" or "diskboot" 4397 4398 loads_echo - see CONFIG_LOADS_ECHO 4399 4400 serverip - TFTP server IP address; needed for tftpboot command 4401 4402 bootretry - see CONFIG_BOOT_RETRY_TIME 4403 4404 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 4405 4406 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 4407 4408 ethprime - controls which interface is used first. 4409 4410 ethact - controls which interface is currently active. 4411 For example you can do the following 4412 4413 => setenv ethact FEC 4414 => ping 192.168.0.1 # traffic sent on FEC 4415 => setenv ethact SCC 4416 => ping 10.0.0.1 # traffic sent on SCC 4417 4418 ethrotate - When set to "no" U-Boot does not go through all 4419 available network interfaces. 4420 It just stays at the currently selected interface. 4421 4422 netretry - When set to "no" each network operation will 4423 either succeed or fail without retrying. 4424 When set to "once" the network operation will 4425 fail when all the available network interfaces 4426 are tried once without success. 4427 Useful on scripts which control the retry operation 4428 themselves. 4429 4430 npe_ucode - set load address for the NPE microcode 4431 4432 silent_linux - If set then Linux will be told to boot silently, by 4433 changing the console to be empty. If "yes" it will be 4434 made silent. If "no" it will not be made silent. If 4435 unset, then it will be made silent if the U-Boot console 4436 is silent. 4437 4438 tftpsrcp - If this is set, the value is used for TFTP's 4439 UDP source port. 4440 4441 tftpdstp - If this is set, the value is used for TFTP's UDP 4442 destination port instead of the Well Know Port 69. 4443 4444 tftpblocksize - Block size to use for TFTP transfers; if not set, 4445 we use the TFTP server's default block size 4446 4447 tftptimeout - Retransmission timeout for TFTP packets (in milli- 4448 seconds, minimum value is 1000 = 1 second). Defines 4449 when a packet is considered to be lost so it has to 4450 be retransmitted. The default is 5000 = 5 seconds. 4451 Lowering this value may make downloads succeed 4452 faster in networks with high packet loss rates or 4453 with unreliable TFTP servers. 4454 4455 tftptimeoutcountmax - maximum count of TFTP timeouts (no 4456 unit, minimum value = 0). Defines how many timeouts 4457 can happen during a single file transfer before that 4458 transfer is aborted. The default is 10, and 0 means 4459 'no timeouts allowed'. Increasing this value may help 4460 downloads succeed with high packet loss rates, or with 4461 unreliable TFTP servers or client hardware. 4462 4463 vlan - When set to a value < 4095 the traffic over 4464 Ethernet is encapsulated/received over 802.1q 4465 VLAN tagged frames. 4466 4467 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 4468 Unsigned value, in milliseconds. If not set, the period will 4469 be either the default (28000), or a value based on 4470 CONFIG_NET_RETRY_COUNT, if defined. This value has 4471 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 4472 4473The following image location variables contain the location of images 4474used in booting. The "Image" column gives the role of the image and is 4475not an environment variable name. The other columns are environment 4476variable names. "File Name" gives the name of the file on a TFTP 4477server, "RAM Address" gives the location in RAM the image will be 4478loaded to, and "Flash Location" gives the image's address in NOR 4479flash or offset in NAND flash. 4480 4481*Note* - these variables don't have to be defined for all boards, some 4482boards currently use other variables for these purposes, and some 4483boards use these variables for other purposes. 4484 4485Image File Name RAM Address Flash Location 4486----- --------- ----------- -------------- 4487u-boot u-boot u-boot_addr_r u-boot_addr 4488Linux kernel bootfile kernel_addr_r kernel_addr 4489device tree blob fdtfile fdt_addr_r fdt_addr 4490ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 4491 4492The following environment variables may be used and automatically 4493updated by the network boot commands ("bootp" and "rarpboot"), 4494depending the information provided by your boot server: 4495 4496 bootfile - see above 4497 dnsip - IP address of your Domain Name Server 4498 dnsip2 - IP address of your secondary Domain Name Server 4499 gatewayip - IP address of the Gateway (Router) to use 4500 hostname - Target hostname 4501 ipaddr - see above 4502 netmask - Subnet Mask 4503 rootpath - Pathname of the root filesystem on the NFS server 4504 serverip - see above 4505 4506 4507There are two special Environment Variables: 4508 4509 serial# - contains hardware identification information such 4510 as type string and/or serial number 4511 ethaddr - Ethernet address 4512 4513These variables can be set only once (usually during manufacturing of 4514the board). U-Boot refuses to delete or overwrite these variables 4515once they have been set once. 4516 4517 4518Further special Environment Variables: 4519 4520 ver - Contains the U-Boot version string as printed 4521 with the "version" command. This variable is 4522 readonly (see CONFIG_VERSION_VARIABLE). 4523 4524 4525Please note that changes to some configuration parameters may take 4526only effect after the next boot (yes, that's just like Windoze :-). 4527 4528 4529Callback functions for environment variables: 4530--------------------------------------------- 4531 4532For some environment variables, the behavior of u-boot needs to change 4533when their values are changed. This functionality allows functions to 4534be associated with arbitrary variables. On creation, overwrite, or 4535deletion, the callback will provide the opportunity for some side 4536effect to happen or for the change to be rejected. 4537 4538The callbacks are named and associated with a function using the 4539U_BOOT_ENV_CALLBACK macro in your board or driver code. 4540 4541These callbacks are associated with variables in one of two ways. The 4542static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4543in the board configuration to a string that defines a list of 4544associations. The list must be in the following format: 4545 4546 entry = variable_name[:callback_name] 4547 list = entry[,list] 4548 4549If the callback name is not specified, then the callback is deleted. 4550Spaces are also allowed anywhere in the list. 4551 4552Callbacks can also be associated by defining the ".callbacks" variable 4553with the same list format above. Any association in ".callbacks" will 4554override any association in the static list. You can define 4555CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4556".callbacks" environment variable in the default or embedded environment. 4557 4558If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4559regular expression. This allows multiple variables to be connected to 4560the same callback without explicitly listing them all out. 4561 4562 4563Command Line Parsing: 4564===================== 4565 4566There are two different command line parsers available with U-Boot: 4567the old "simple" one, and the much more powerful "hush" shell: 4568 4569Old, simple command line parser: 4570-------------------------------- 4571 4572- supports environment variables (through setenv / saveenv commands) 4573- several commands on one line, separated by ';' 4574- variable substitution using "... ${name} ..." syntax 4575- special characters ('$', ';') can be escaped by prefixing with '\', 4576 for example: 4577 setenv bootcmd bootm \${address} 4578- You can also escape text by enclosing in single apostrophes, for example: 4579 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4580 4581Hush shell: 4582----------- 4583 4584- similar to Bourne shell, with control structures like 4585 if...then...else...fi, for...do...done; while...do...done, 4586 until...do...done, ... 4587- supports environment ("global") variables (through setenv / saveenv 4588 commands) and local shell variables (through standard shell syntax 4589 "name=value"); only environment variables can be used with "run" 4590 command 4591 4592General rules: 4593-------------- 4594 4595(1) If a command line (or an environment variable executed by a "run" 4596 command) contains several commands separated by semicolon, and 4597 one of these commands fails, then the remaining commands will be 4598 executed anyway. 4599 4600(2) If you execute several variables with one call to run (i. e. 4601 calling run with a list of variables as arguments), any failing 4602 command will cause "run" to terminate, i. e. the remaining 4603 variables are not executed. 4604 4605Note for Redundant Ethernet Interfaces: 4606======================================= 4607 4608Some boards come with redundant Ethernet interfaces; U-Boot supports 4609such configurations and is capable of automatic selection of a 4610"working" interface when needed. MAC assignment works as follows: 4611 4612Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4613MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4614"eth1addr" (=>eth1), "eth2addr", ... 4615 4616If the network interface stores some valid MAC address (for instance 4617in SROM), this is used as default address if there is NO correspon- 4618ding setting in the environment; if the corresponding environment 4619variable is set, this overrides the settings in the card; that means: 4620 4621o If the SROM has a valid MAC address, and there is no address in the 4622 environment, the SROM's address is used. 4623 4624o If there is no valid address in the SROM, and a definition in the 4625 environment exists, then the value from the environment variable is 4626 used. 4627 4628o If both the SROM and the environment contain a MAC address, and 4629 both addresses are the same, this MAC address is used. 4630 4631o If both the SROM and the environment contain a MAC address, and the 4632 addresses differ, the value from the environment is used and a 4633 warning is printed. 4634 4635o If neither SROM nor the environment contain a MAC address, an error 4636 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4637 a random, locally-assigned MAC is used. 4638 4639If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4640will be programmed into hardware as part of the initialization process. This 4641may be skipped by setting the appropriate 'ethmacskip' environment variable. 4642The naming convention is as follows: 4643"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4644 4645Image Formats: 4646============== 4647 4648U-Boot is capable of booting (and performing other auxiliary operations on) 4649images in two formats: 4650 4651New uImage format (FIT) 4652----------------------- 4653 4654Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4655to Flattened Device Tree). It allows the use of images with multiple 4656components (several kernels, ramdisks, etc.), with contents protected by 4657SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4658 4659 4660Old uImage format 4661----------------- 4662 4663Old image format is based on binary files which can be basically anything, 4664preceded by a special header; see the definitions in include/image.h for 4665details; basically, the header defines the following image properties: 4666 4667* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4668 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4669 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4670 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4671 INTEGRITY). 4672* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4673 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4674 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4675* Compression Type (uncompressed, gzip, bzip2) 4676* Load Address 4677* Entry Point 4678* Image Name 4679* Image Timestamp 4680 4681The header is marked by a special Magic Number, and both the header 4682and the data portions of the image are secured against corruption by 4683CRC32 checksums. 4684 4685 4686Linux Support: 4687============== 4688 4689Although U-Boot should support any OS or standalone application 4690easily, the main focus has always been on Linux during the design of 4691U-Boot. 4692 4693U-Boot includes many features that so far have been part of some 4694special "boot loader" code within the Linux kernel. Also, any 4695"initrd" images to be used are no longer part of one big Linux image; 4696instead, kernel and "initrd" are separate images. This implementation 4697serves several purposes: 4698 4699- the same features can be used for other OS or standalone 4700 applications (for instance: using compressed images to reduce the 4701 Flash memory footprint) 4702 4703- it becomes much easier to port new Linux kernel versions because 4704 lots of low-level, hardware dependent stuff are done by U-Boot 4705 4706- the same Linux kernel image can now be used with different "initrd" 4707 images; of course this also means that different kernel images can 4708 be run with the same "initrd". This makes testing easier (you don't 4709 have to build a new "zImage.initrd" Linux image when you just 4710 change a file in your "initrd"). Also, a field-upgrade of the 4711 software is easier now. 4712 4713 4714Linux HOWTO: 4715============ 4716 4717Porting Linux to U-Boot based systems: 4718--------------------------------------- 4719 4720U-Boot cannot save you from doing all the necessary modifications to 4721configure the Linux device drivers for use with your target hardware 4722(no, we don't intend to provide a full virtual machine interface to 4723Linux :-). 4724 4725But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4726 4727Just make sure your machine specific header file (for instance 4728include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4729Information structure as we define in include/asm-<arch>/u-boot.h, 4730and make sure that your definition of IMAP_ADDR uses the same value 4731as your U-Boot configuration in CONFIG_SYS_IMMR. 4732 4733Note that U-Boot now has a driver model, a unified model for drivers. 4734If you are adding a new driver, plumb it into driver model. If there 4735is no uclass available, you are encouraged to create one. See 4736doc/driver-model. 4737 4738 4739Configuring the Linux kernel: 4740----------------------------- 4741 4742No specific requirements for U-Boot. Make sure you have some root 4743device (initial ramdisk, NFS) for your target system. 4744 4745 4746Building a Linux Image: 4747----------------------- 4748 4749With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4750not used. If you use recent kernel source, a new build target 4751"uImage" will exist which automatically builds an image usable by 4752U-Boot. Most older kernels also have support for a "pImage" target, 4753which was introduced for our predecessor project PPCBoot and uses a 4754100% compatible format. 4755 4756Example: 4757 4758 make TQM850L_defconfig 4759 make oldconfig 4760 make dep 4761 make uImage 4762 4763The "uImage" build target uses a special tool (in 'tools/mkimage') to 4764encapsulate a compressed Linux kernel image with header information, 4765CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4766 4767* build a standard "vmlinux" kernel image (in ELF binary format): 4768 4769* convert the kernel into a raw binary image: 4770 4771 ${CROSS_COMPILE}-objcopy -O binary \ 4772 -R .note -R .comment \ 4773 -S vmlinux linux.bin 4774 4775* compress the binary image: 4776 4777 gzip -9 linux.bin 4778 4779* package compressed binary image for U-Boot: 4780 4781 mkimage -A ppc -O linux -T kernel -C gzip \ 4782 -a 0 -e 0 -n "Linux Kernel Image" \ 4783 -d linux.bin.gz uImage 4784 4785 4786The "mkimage" tool can also be used to create ramdisk images for use 4787with U-Boot, either separated from the Linux kernel image, or 4788combined into one file. "mkimage" encapsulates the images with a 64 4789byte header containing information about target architecture, 4790operating system, image type, compression method, entry points, time 4791stamp, CRC32 checksums, etc. 4792 4793"mkimage" can be called in two ways: to verify existing images and 4794print the header information, or to build new images. 4795 4796In the first form (with "-l" option) mkimage lists the information 4797contained in the header of an existing U-Boot image; this includes 4798checksum verification: 4799 4800 tools/mkimage -l image 4801 -l ==> list image header information 4802 4803The second form (with "-d" option) is used to build a U-Boot image 4804from a "data file" which is used as image payload: 4805 4806 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4807 -n name -d data_file image 4808 -A ==> set architecture to 'arch' 4809 -O ==> set operating system to 'os' 4810 -T ==> set image type to 'type' 4811 -C ==> set compression type 'comp' 4812 -a ==> set load address to 'addr' (hex) 4813 -e ==> set entry point to 'ep' (hex) 4814 -n ==> set image name to 'name' 4815 -d ==> use image data from 'datafile' 4816 4817Right now, all Linux kernels for PowerPC systems use the same load 4818address (0x00000000), but the entry point address depends on the 4819kernel version: 4820 4821- 2.2.x kernels have the entry point at 0x0000000C, 4822- 2.3.x and later kernels have the entry point at 0x00000000. 4823 4824So a typical call to build a U-Boot image would read: 4825 4826 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4827 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4828 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4829 > examples/uImage.TQM850L 4830 Image Name: 2.4.4 kernel for TQM850L 4831 Created: Wed Jul 19 02:34:59 2000 4832 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4833 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4834 Load Address: 0x00000000 4835 Entry Point: 0x00000000 4836 4837To verify the contents of the image (or check for corruption): 4838 4839 -> tools/mkimage -l examples/uImage.TQM850L 4840 Image Name: 2.4.4 kernel for TQM850L 4841 Created: Wed Jul 19 02:34:59 2000 4842 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4843 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4844 Load Address: 0x00000000 4845 Entry Point: 0x00000000 4846 4847NOTE: for embedded systems where boot time is critical you can trade 4848speed for memory and install an UNCOMPRESSED image instead: this 4849needs more space in Flash, but boots much faster since it does not 4850need to be uncompressed: 4851 4852 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4853 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4854 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4855 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4856 > examples/uImage.TQM850L-uncompressed 4857 Image Name: 2.4.4 kernel for TQM850L 4858 Created: Wed Jul 19 02:34:59 2000 4859 Image Type: PowerPC Linux Kernel Image (uncompressed) 4860 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4861 Load Address: 0x00000000 4862 Entry Point: 0x00000000 4863 4864 4865Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4866when your kernel is intended to use an initial ramdisk: 4867 4868 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4869 > -A ppc -O linux -T ramdisk -C gzip \ 4870 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4871 Image Name: Simple Ramdisk Image 4872 Created: Wed Jan 12 14:01:50 2000 4873 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4874 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4875 Load Address: 0x00000000 4876 Entry Point: 0x00000000 4877 4878The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4879option performs the converse operation of the mkimage's second form (the "-d" 4880option). Given an image built by mkimage, the dumpimage extracts a "data file" 4881from the image: 4882 4883 tools/dumpimage -i image -T type -p position data_file 4884 -i ==> extract from the 'image' a specific 'data_file' 4885 -T ==> set image type to 'type' 4886 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4887 4888 4889Installing a Linux Image: 4890------------------------- 4891 4892To downloading a U-Boot image over the serial (console) interface, 4893you must convert the image to S-Record format: 4894 4895 objcopy -I binary -O srec examples/image examples/image.srec 4896 4897The 'objcopy' does not understand the information in the U-Boot 4898image header, so the resulting S-Record file will be relative to 4899address 0x00000000. To load it to a given address, you need to 4900specify the target address as 'offset' parameter with the 'loads' 4901command. 4902 4903Example: install the image to address 0x40100000 (which on the 4904TQM8xxL is in the first Flash bank): 4905 4906 => erase 40100000 401FFFFF 4907 4908 .......... done 4909 Erased 8 sectors 4910 4911 => loads 40100000 4912 ## Ready for S-Record download ... 4913 ~>examples/image.srec 4914 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4915 ... 4916 15989 15990 15991 15992 4917 [file transfer complete] 4918 [connected] 4919 ## Start Addr = 0x00000000 4920 4921 4922You can check the success of the download using the 'iminfo' command; 4923this includes a checksum verification so you can be sure no data 4924corruption happened: 4925 4926 => imi 40100000 4927 4928 ## Checking Image at 40100000 ... 4929 Image Name: 2.2.13 for initrd on TQM850L 4930 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4931 Data Size: 335725 Bytes = 327 kB = 0 MB 4932 Load Address: 00000000 4933 Entry Point: 0000000c 4934 Verifying Checksum ... OK 4935 4936 4937Boot Linux: 4938----------- 4939 4940The "bootm" command is used to boot an application that is stored in 4941memory (RAM or Flash). In case of a Linux kernel image, the contents 4942of the "bootargs" environment variable is passed to the kernel as 4943parameters. You can check and modify this variable using the 4944"printenv" and "setenv" commands: 4945 4946 4947 => printenv bootargs 4948 bootargs=root=/dev/ram 4949 4950 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4951 4952 => printenv bootargs 4953 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4954 4955 => bootm 40020000 4956 ## Booting Linux kernel at 40020000 ... 4957 Image Name: 2.2.13 for NFS on TQM850L 4958 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4959 Data Size: 381681 Bytes = 372 kB = 0 MB 4960 Load Address: 00000000 4961 Entry Point: 0000000c 4962 Verifying Checksum ... OK 4963 Uncompressing Kernel Image ... OK 4964 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 4965 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4966 time_init: decrementer frequency = 187500000/60 4967 Calibrating delay loop... 49.77 BogoMIPS 4968 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4969 ... 4970 4971If you want to boot a Linux kernel with initial RAM disk, you pass 4972the memory addresses of both the kernel and the initrd image (PPBCOOT 4973format!) to the "bootm" command: 4974 4975 => imi 40100000 40200000 4976 4977 ## Checking Image at 40100000 ... 4978 Image Name: 2.2.13 for initrd on TQM850L 4979 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4980 Data Size: 335725 Bytes = 327 kB = 0 MB 4981 Load Address: 00000000 4982 Entry Point: 0000000c 4983 Verifying Checksum ... OK 4984 4985 ## Checking Image at 40200000 ... 4986 Image Name: Simple Ramdisk Image 4987 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4988 Data Size: 566530 Bytes = 553 kB = 0 MB 4989 Load Address: 00000000 4990 Entry Point: 00000000 4991 Verifying Checksum ... OK 4992 4993 => bootm 40100000 40200000 4994 ## Booting Linux kernel at 40100000 ... 4995 Image Name: 2.2.13 for initrd on TQM850L 4996 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4997 Data Size: 335725 Bytes = 327 kB = 0 MB 4998 Load Address: 00000000 4999 Entry Point: 0000000c 5000 Verifying Checksum ... OK 5001 Uncompressing Kernel Image ... OK 5002 ## Loading RAMDisk Image at 40200000 ... 5003 Image Name: Simple Ramdisk Image 5004 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 5005 Data Size: 566530 Bytes = 553 kB = 0 MB 5006 Load Address: 00000000 5007 Entry Point: 00000000 5008 Verifying Checksum ... OK 5009 Loading Ramdisk ... OK 5010 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 5011 Boot arguments: root=/dev/ram 5012 time_init: decrementer frequency = 187500000/60 5013 Calibrating delay loop... 49.77 BogoMIPS 5014 ... 5015 RAMDISK: Compressed image found at block 0 5016 VFS: Mounted root (ext2 filesystem). 5017 5018 bash# 5019 5020Boot Linux and pass a flat device tree: 5021----------- 5022 5023First, U-Boot must be compiled with the appropriate defines. See the section 5024titled "Linux Kernel Interface" above for a more in depth explanation. The 5025following is an example of how to start a kernel and pass an updated 5026flat device tree: 5027 5028=> print oftaddr 5029oftaddr=0x300000 5030=> print oft 5031oft=oftrees/mpc8540ads.dtb 5032=> tftp $oftaddr $oft 5033Speed: 1000, full duplex 5034Using TSEC0 device 5035TFTP from server 192.168.1.1; our IP address is 192.168.1.101 5036Filename 'oftrees/mpc8540ads.dtb'. 5037Load address: 0x300000 5038Loading: # 5039done 5040Bytes transferred = 4106 (100a hex) 5041=> tftp $loadaddr $bootfile 5042Speed: 1000, full duplex 5043Using TSEC0 device 5044TFTP from server 192.168.1.1; our IP address is 192.168.1.2 5045Filename 'uImage'. 5046Load address: 0x200000 5047Loading:############ 5048done 5049Bytes transferred = 1029407 (fb51f hex) 5050=> print loadaddr 5051loadaddr=200000 5052=> print oftaddr 5053oftaddr=0x300000 5054=> bootm $loadaddr - $oftaddr 5055## Booting image at 00200000 ... 5056 Image Name: Linux-2.6.17-dirty 5057 Image Type: PowerPC Linux Kernel Image (gzip compressed) 5058 Data Size: 1029343 Bytes = 1005.2 kB 5059 Load Address: 00000000 5060 Entry Point: 00000000 5061 Verifying Checksum ... OK 5062 Uncompressing Kernel Image ... OK 5063Booting using flat device tree at 0x300000 5064Using MPC85xx ADS machine description 5065Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 5066[snip] 5067 5068 5069More About U-Boot Image Types: 5070------------------------------ 5071 5072U-Boot supports the following image types: 5073 5074 "Standalone Programs" are directly runnable in the environment 5075 provided by U-Boot; it is expected that (if they behave 5076 well) you can continue to work in U-Boot after return from 5077 the Standalone Program. 5078 "OS Kernel Images" are usually images of some Embedded OS which 5079 will take over control completely. Usually these programs 5080 will install their own set of exception handlers, device 5081 drivers, set up the MMU, etc. - this means, that you cannot 5082 expect to re-enter U-Boot except by resetting the CPU. 5083 "RAMDisk Images" are more or less just data blocks, and their 5084 parameters (address, size) are passed to an OS kernel that is 5085 being started. 5086 "Multi-File Images" contain several images, typically an OS 5087 (Linux) kernel image and one or more data images like 5088 RAMDisks. This construct is useful for instance when you want 5089 to boot over the network using BOOTP etc., where the boot 5090 server provides just a single image file, but you want to get 5091 for instance an OS kernel and a RAMDisk image. 5092 5093 "Multi-File Images" start with a list of image sizes, each 5094 image size (in bytes) specified by an "uint32_t" in network 5095 byte order. This list is terminated by an "(uint32_t)0". 5096 Immediately after the terminating 0 follow the images, one by 5097 one, all aligned on "uint32_t" boundaries (size rounded up to 5098 a multiple of 4 bytes). 5099 5100 "Firmware Images" are binary images containing firmware (like 5101 U-Boot or FPGA images) which usually will be programmed to 5102 flash memory. 5103 5104 "Script files" are command sequences that will be executed by 5105 U-Boot's command interpreter; this feature is especially 5106 useful when you configure U-Boot to use a real shell (hush) 5107 as command interpreter. 5108 5109Booting the Linux zImage: 5110------------------------- 5111 5112On some platforms, it's possible to boot Linux zImage. This is done 5113using the "bootz" command. The syntax of "bootz" command is the same 5114as the syntax of "bootm" command. 5115 5116Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 5117kernel with raw initrd images. The syntax is slightly different, the 5118address of the initrd must be augmented by it's size, in the following 5119format: "<initrd addres>:<initrd size>". 5120 5121 5122Standalone HOWTO: 5123================= 5124 5125One of the features of U-Boot is that you can dynamically load and 5126run "standalone" applications, which can use some resources of 5127U-Boot like console I/O functions or interrupt services. 5128 5129Two simple examples are included with the sources: 5130 5131"Hello World" Demo: 5132------------------- 5133 5134'examples/hello_world.c' contains a small "Hello World" Demo 5135application; it is automatically compiled when you build U-Boot. 5136It's configured to run at address 0x00040004, so you can play with it 5137like that: 5138 5139 => loads 5140 ## Ready for S-Record download ... 5141 ~>examples/hello_world.srec 5142 1 2 3 4 5 6 7 8 9 10 11 ... 5143 [file transfer complete] 5144 [connected] 5145 ## Start Addr = 0x00040004 5146 5147 => go 40004 Hello World! This is a test. 5148 ## Starting application at 0x00040004 ... 5149 Hello World 5150 argc = 7 5151 argv[0] = "40004" 5152 argv[1] = "Hello" 5153 argv[2] = "World!" 5154 argv[3] = "This" 5155 argv[4] = "is" 5156 argv[5] = "a" 5157 argv[6] = "test." 5158 argv[7] = "<NULL>" 5159 Hit any key to exit ... 5160 5161 ## Application terminated, rc = 0x0 5162 5163Another example, which demonstrates how to register a CPM interrupt 5164handler with the U-Boot code, can be found in 'examples/timer.c'. 5165Here, a CPM timer is set up to generate an interrupt every second. 5166The interrupt service routine is trivial, just printing a '.' 5167character, but this is just a demo program. The application can be 5168controlled by the following keys: 5169 5170 ? - print current values og the CPM Timer registers 5171 b - enable interrupts and start timer 5172 e - stop timer and disable interrupts 5173 q - quit application 5174 5175 => loads 5176 ## Ready for S-Record download ... 5177 ~>examples/timer.srec 5178 1 2 3 4 5 6 7 8 9 10 11 ... 5179 [file transfer complete] 5180 [connected] 5181 ## Start Addr = 0x00040004 5182 5183 => go 40004 5184 ## Starting application at 0x00040004 ... 5185 TIMERS=0xfff00980 5186 Using timer 1 5187 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 5188 5189Hit 'b': 5190 [q, b, e, ?] Set interval 1000000 us 5191 Enabling timer 5192Hit '?': 5193 [q, b, e, ?] ........ 5194 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 5195Hit '?': 5196 [q, b, e, ?] . 5197 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 5198Hit '?': 5199 [q, b, e, ?] . 5200 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 5201Hit '?': 5202 [q, b, e, ?] . 5203 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 5204Hit 'e': 5205 [q, b, e, ?] ...Stopping timer 5206Hit 'q': 5207 [q, b, e, ?] ## Application terminated, rc = 0x0 5208 5209 5210Minicom warning: 5211================ 5212 5213Over time, many people have reported problems when trying to use the 5214"minicom" terminal emulation program for serial download. I (wd) 5215consider minicom to be broken, and recommend not to use it. Under 5216Unix, I recommend to use C-Kermit for general purpose use (and 5217especially for kermit binary protocol download ("loadb" command), and 5218use "cu" for S-Record download ("loads" command). See 5219http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 5220for help with kermit. 5221 5222 5223Nevertheless, if you absolutely want to use it try adding this 5224configuration to your "File transfer protocols" section: 5225 5226 Name Program Name U/D FullScr IO-Red. Multi 5227 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 5228 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 5229 5230 5231NetBSD Notes: 5232============= 5233 5234Starting at version 0.9.2, U-Boot supports NetBSD both as host 5235(build U-Boot) and target system (boots NetBSD/mpc8xx). 5236 5237Building requires a cross environment; it is known to work on 5238NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 5239need gmake since the Makefiles are not compatible with BSD make). 5240Note that the cross-powerpc package does not install include files; 5241attempting to build U-Boot will fail because <machine/ansi.h> is 5242missing. This file has to be installed and patched manually: 5243 5244 # cd /usr/pkg/cross/powerpc-netbsd/include 5245 # mkdir powerpc 5246 # ln -s powerpc machine 5247 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 5248 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 5249 5250Native builds *don't* work due to incompatibilities between native 5251and U-Boot include files. 5252 5253Booting assumes that (the first part of) the image booted is a 5254stage-2 loader which in turn loads and then invokes the kernel 5255proper. Loader sources will eventually appear in the NetBSD source 5256tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 5257meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 5258 5259 5260Implementation Internals: 5261========================= 5262 5263The following is not intended to be a complete description of every 5264implementation detail. However, it should help to understand the 5265inner workings of U-Boot and make it easier to port it to custom 5266hardware. 5267 5268 5269Initial Stack, Global Data: 5270--------------------------- 5271 5272The implementation of U-Boot is complicated by the fact that U-Boot 5273starts running out of ROM (flash memory), usually without access to 5274system RAM (because the memory controller is not initialized yet). 5275This means that we don't have writable Data or BSS segments, and BSS 5276is not initialized as zero. To be able to get a C environment working 5277at all, we have to allocate at least a minimal stack. Implementation 5278options for this are defined and restricted by the CPU used: Some CPU 5279models provide on-chip memory (like the IMMR area on MPC8xx and 5280MPC826x processors), on others (parts of) the data cache can be 5281locked as (mis-) used as memory, etc. 5282 5283 Chris Hallinan posted a good summary of these issues to the 5284 U-Boot mailing list: 5285 5286 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 5287 From: "Chris Hallinan" <clh@net1plus.com> 5288 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 5289 ... 5290 5291 Correct me if I'm wrong, folks, but the way I understand it 5292 is this: Using DCACHE as initial RAM for Stack, etc, does not 5293 require any physical RAM backing up the cache. The cleverness 5294 is that the cache is being used as a temporary supply of 5295 necessary storage before the SDRAM controller is setup. It's 5296 beyond the scope of this list to explain the details, but you 5297 can see how this works by studying the cache architecture and 5298 operation in the architecture and processor-specific manuals. 5299 5300 OCM is On Chip Memory, which I believe the 405GP has 4K. It 5301 is another option for the system designer to use as an 5302 initial stack/RAM area prior to SDRAM being available. Either 5303 option should work for you. Using CS 4 should be fine if your 5304 board designers haven't used it for something that would 5305 cause you grief during the initial boot! It is frequently not 5306 used. 5307 5308 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 5309 with your processor/board/system design. The default value 5310 you will find in any recent u-boot distribution in 5311 walnut.h should work for you. I'd set it to a value larger 5312 than your SDRAM module. If you have a 64MB SDRAM module, set 5313 it above 400_0000. Just make sure your board has no resources 5314 that are supposed to respond to that address! That code in 5315 start.S has been around a while and should work as is when 5316 you get the config right. 5317 5318 -Chris Hallinan 5319 DS4.COM, Inc. 5320 5321It is essential to remember this, since it has some impact on the C 5322code for the initialization procedures: 5323 5324* Initialized global data (data segment) is read-only. Do not attempt 5325 to write it. 5326 5327* Do not use any uninitialized global data (or implicitly initialized 5328 as zero data - BSS segment) at all - this is undefined, initiali- 5329 zation is performed later (when relocating to RAM). 5330 5331* Stack space is very limited. Avoid big data buffers or things like 5332 that. 5333 5334Having only the stack as writable memory limits means we cannot use 5335normal global data to share information between the code. But it 5336turned out that the implementation of U-Boot can be greatly 5337simplified by making a global data structure (gd_t) available to all 5338functions. We could pass a pointer to this data as argument to _all_ 5339functions, but this would bloat the code. Instead we use a feature of 5340the GCC compiler (Global Register Variables) to share the data: we 5341place a pointer (gd) to the global data into a register which we 5342reserve for this purpose. 5343 5344When choosing a register for such a purpose we are restricted by the 5345relevant (E)ABI specifications for the current architecture, and by 5346GCC's implementation. 5347 5348For PowerPC, the following registers have specific use: 5349 R1: stack pointer 5350 R2: reserved for system use 5351 R3-R4: parameter passing and return values 5352 R5-R10: parameter passing 5353 R13: small data area pointer 5354 R30: GOT pointer 5355 R31: frame pointer 5356 5357 (U-Boot also uses R12 as internal GOT pointer. r12 5358 is a volatile register so r12 needs to be reset when 5359 going back and forth between asm and C) 5360 5361 ==> U-Boot will use R2 to hold a pointer to the global data 5362 5363 Note: on PPC, we could use a static initializer (since the 5364 address of the global data structure is known at compile time), 5365 but it turned out that reserving a register results in somewhat 5366 smaller code - although the code savings are not that big (on 5367 average for all boards 752 bytes for the whole U-Boot image, 5368 624 text + 127 data). 5369 5370On ARM, the following registers are used: 5371 5372 R0: function argument word/integer result 5373 R1-R3: function argument word 5374 R9: platform specific 5375 R10: stack limit (used only if stack checking is enabled) 5376 R11: argument (frame) pointer 5377 R12: temporary workspace 5378 R13: stack pointer 5379 R14: link register 5380 R15: program counter 5381 5382 ==> U-Boot will use R9 to hold a pointer to the global data 5383 5384 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 5385 5386On Nios II, the ABI is documented here: 5387 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 5388 5389 ==> U-Boot will use gp to hold a pointer to the global data 5390 5391 Note: on Nios II, we give "-G0" option to gcc and don't use gp 5392 to access small data sections, so gp is free. 5393 5394On NDS32, the following registers are used: 5395 5396 R0-R1: argument/return 5397 R2-R5: argument 5398 R15: temporary register for assembler 5399 R16: trampoline register 5400 R28: frame pointer (FP) 5401 R29: global pointer (GP) 5402 R30: link register (LP) 5403 R31: stack pointer (SP) 5404 PC: program counter (PC) 5405 5406 ==> U-Boot will use R10 to hold a pointer to the global data 5407 5408NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 5409or current versions of GCC may "optimize" the code too much. 5410 5411Memory Management: 5412------------------ 5413 5414U-Boot runs in system state and uses physical addresses, i.e. the 5415MMU is not used either for address mapping nor for memory protection. 5416 5417The available memory is mapped to fixed addresses using the memory 5418controller. In this process, a contiguous block is formed for each 5419memory type (Flash, SDRAM, SRAM), even when it consists of several 5420physical memory banks. 5421 5422U-Boot is installed in the first 128 kB of the first Flash bank (on 5423TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 5424booting and sizing and initializing DRAM, the code relocates itself 5425to the upper end of DRAM. Immediately below the U-Boot code some 5426memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 5427configuration setting]. Below that, a structure with global Board 5428Info data is placed, followed by the stack (growing downward). 5429 5430Additionally, some exception handler code is copied to the low 8 kB 5431of DRAM (0x00000000 ... 0x00001FFF). 5432 5433So a typical memory configuration with 16 MB of DRAM could look like 5434this: 5435 5436 0x0000 0000 Exception Vector code 5437 : 5438 0x0000 1FFF 5439 0x0000 2000 Free for Application Use 5440 : 5441 : 5442 5443 : 5444 : 5445 0x00FB FF20 Monitor Stack (Growing downward) 5446 0x00FB FFAC Board Info Data and permanent copy of global data 5447 0x00FC 0000 Malloc Arena 5448 : 5449 0x00FD FFFF 5450 0x00FE 0000 RAM Copy of Monitor Code 5451 ... eventually: LCD or video framebuffer 5452 ... eventually: pRAM (Protected RAM - unchanged by reset) 5453 0x00FF FFFF [End of RAM] 5454 5455 5456System Initialization: 5457---------------------- 5458 5459In the reset configuration, U-Boot starts at the reset entry point 5460(on most PowerPC systems at address 0x00000100). Because of the reset 5461configuration for CS0# this is a mirror of the on board Flash memory. 5462To be able to re-map memory U-Boot then jumps to its link address. 5463To be able to implement the initialization code in C, a (small!) 5464initial stack is set up in the internal Dual Ported RAM (in case CPUs 5465which provide such a feature like), or in a locked part of the data 5466cache. After that, U-Boot initializes the CPU core, the caches and 5467the SIU. 5468 5469Next, all (potentially) available memory banks are mapped using a 5470preliminary mapping. For example, we put them on 512 MB boundaries 5471(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 5472on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 5473programmed for SDRAM access. Using the temporary configuration, a 5474simple memory test is run that determines the size of the SDRAM 5475banks. 5476 5477When there is more than one SDRAM bank, and the banks are of 5478different size, the largest is mapped first. For equal size, the first 5479bank (CS2#) is mapped first. The first mapping is always for address 54800x00000000, with any additional banks following immediately to create 5481contiguous memory starting from 0. 5482 5483Then, the monitor installs itself at the upper end of the SDRAM area 5484and allocates memory for use by malloc() and for the global Board 5485Info data; also, the exception vector code is copied to the low RAM 5486pages, and the final stack is set up. 5487 5488Only after this relocation will you have a "normal" C environment; 5489until that you are restricted in several ways, mostly because you are 5490running from ROM, and because the code will have to be relocated to a 5491new address in RAM. 5492 5493 5494U-Boot Porting Guide: 5495---------------------- 5496 5497[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 5498list, October 2002] 5499 5500 5501int main(int argc, char *argv[]) 5502{ 5503 sighandler_t no_more_time; 5504 5505 signal(SIGALRM, no_more_time); 5506 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5507 5508 if (available_money > available_manpower) { 5509 Pay consultant to port U-Boot; 5510 return 0; 5511 } 5512 5513 Download latest U-Boot source; 5514 5515 Subscribe to u-boot mailing list; 5516 5517 if (clueless) 5518 email("Hi, I am new to U-Boot, how do I get started?"); 5519 5520 while (learning) { 5521 Read the README file in the top level directory; 5522 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5523 Read applicable doc/*.README; 5524 Read the source, Luke; 5525 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5526 } 5527 5528 if (available_money > toLocalCurrency ($2500)) 5529 Buy a BDI3000; 5530 else 5531 Add a lot of aggravation and time; 5532 5533 if (a similar board exists) { /* hopefully... */ 5534 cp -a board/<similar> board/<myboard> 5535 cp include/configs/<similar>.h include/configs/<myboard>.h 5536 } else { 5537 Create your own board support subdirectory; 5538 Create your own board include/configs/<myboard>.h file; 5539 } 5540 Edit new board/<myboard> files 5541 Edit new include/configs/<myboard>.h 5542 5543 while (!accepted) { 5544 while (!running) { 5545 do { 5546 Add / modify source code; 5547 } until (compiles); 5548 Debug; 5549 if (clueless) 5550 email("Hi, I am having problems..."); 5551 } 5552 Send patch file to the U-Boot email list; 5553 if (reasonable critiques) 5554 Incorporate improvements from email list code review; 5555 else 5556 Defend code as written; 5557 } 5558 5559 return 0; 5560} 5561 5562void no_more_time (int sig) 5563{ 5564 hire_a_guru(); 5565} 5566 5567 5568Coding Standards: 5569----------------- 5570 5571All contributions to U-Boot should conform to the Linux kernel 5572coding style; see the file "Documentation/CodingStyle" and the script 5573"scripts/Lindent" in your Linux kernel source directory. 5574 5575Source files originating from a different project (for example the 5576MTD subsystem) are generally exempt from these guidelines and are not 5577reformatted to ease subsequent migration to newer versions of those 5578sources. 5579 5580Please note that U-Boot is implemented in C (and to some small parts in 5581Assembler); no C++ is used, so please do not use C++ style comments (//) 5582in your code. 5583 5584Please also stick to the following formatting rules: 5585- remove any trailing white space 5586- use TAB characters for indentation and vertical alignment, not spaces 5587- make sure NOT to use DOS '\r\n' line feeds 5588- do not add more than 2 consecutive empty lines to source files 5589- do not add trailing empty lines to source files 5590 5591Submissions which do not conform to the standards may be returned 5592with a request to reformat the changes. 5593 5594 5595Submitting Patches: 5596------------------- 5597 5598Since the number of patches for U-Boot is growing, we need to 5599establish some rules. Submissions which do not conform to these rules 5600may be rejected, even when they contain important and valuable stuff. 5601 5602Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5603 5604Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5605see http://lists.denx.de/mailman/listinfo/u-boot 5606 5607When you send a patch, please include the following information with 5608it: 5609 5610* For bug fixes: a description of the bug and how your patch fixes 5611 this bug. Please try to include a way of demonstrating that the 5612 patch actually fixes something. 5613 5614* For new features: a description of the feature and your 5615 implementation. 5616 5617* A CHANGELOG entry as plaintext (separate from the patch) 5618 5619* For major contributions, add a MAINTAINERS file with your 5620 information and associated file and directory references. 5621 5622* When you add support for a new board, don't forget to add a 5623 maintainer e-mail address to the boards.cfg file, too. 5624 5625* If your patch adds new configuration options, don't forget to 5626 document these in the README file. 5627 5628* The patch itself. If you are using git (which is *strongly* 5629 recommended) you can easily generate the patch using the 5630 "git format-patch". If you then use "git send-email" to send it to 5631 the U-Boot mailing list, you will avoid most of the common problems 5632 with some other mail clients. 5633 5634 If you cannot use git, use "diff -purN OLD NEW". If your version of 5635 diff does not support these options, then get the latest version of 5636 GNU diff. 5637 5638 The current directory when running this command shall be the parent 5639 directory of the U-Boot source tree (i. e. please make sure that 5640 your patch includes sufficient directory information for the 5641 affected files). 5642 5643 We prefer patches as plain text. MIME attachments are discouraged, 5644 and compressed attachments must not be used. 5645 5646* If one logical set of modifications affects or creates several 5647 files, all these changes shall be submitted in a SINGLE patch file. 5648 5649* Changesets that contain different, unrelated modifications shall be 5650 submitted as SEPARATE patches, one patch per changeset. 5651 5652 5653Notes: 5654 5655* Before sending the patch, run the buildman script on your patched 5656 source tree and make sure that no errors or warnings are reported 5657 for any of the boards. 5658 5659* Keep your modifications to the necessary minimum: A patch 5660 containing several unrelated changes or arbitrary reformats will be 5661 returned with a request to re-formatting / split it. 5662 5663* If you modify existing code, make sure that your new code does not 5664 add to the memory footprint of the code ;-) Small is beautiful! 5665 When adding new features, these should compile conditionally only 5666 (using #ifdef), and the resulting code with the new feature 5667 disabled must not need more memory than the old code without your 5668 modification. 5669 5670* Remember that there is a size limit of 100 kB per message on the 5671 u-boot mailing list. Bigger patches will be moderated. If they are 5672 reasonable and not too big, they will be acknowledged. But patches 5673 bigger than the size limit should be avoided. 5674