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 /riscv Files generic to RISC-V architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316- ARM Platform Bus Type(CCI): 317 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which 318 provides full cache coherency between two clusters of multi-core 319 CPUs and I/O coherency for devices and I/O masters 320 321 CONFIG_SYS_FSL_HAS_CCI400 322 323 Defined For SoC that has cache coherent interconnect 324 CCN-400 325 326 CONFIG_SYS_FSL_HAS_CCN504 327 328 Defined for SoC that has cache coherent interconnect CCN-504 329 330The following options need to be configured: 331 332- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 333 334- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 335 336- Marvell Family Member 337 CONFIG_SYS_MVFS - define it if you want to enable 338 multiple fs option at one time 339 for marvell soc family 340 341- 85xx CPU Options: 342 CONFIG_SYS_PPC64 343 344 Specifies that the core is a 64-bit PowerPC implementation (implements 345 the "64" category of the Power ISA). This is necessary for ePAPR 346 compliance, among other possible reasons. 347 348 CONFIG_SYS_FSL_TBCLK_DIV 349 350 Defines the core time base clock divider ratio compared to the 351 system clock. On most PQ3 devices this is 8, on newer QorIQ 352 devices it can be 16 or 32. The ratio varies from SoC to Soc. 353 354 CONFIG_SYS_FSL_PCIE_COMPAT 355 356 Defines the string to utilize when trying to match PCIe device 357 tree nodes for the given platform. 358 359 CONFIG_SYS_FSL_ERRATUM_A004510 360 361 Enables a workaround for erratum A004510. If set, 362 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 363 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 364 365 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 366 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 367 368 Defines one or two SoC revisions (low 8 bits of SVR) 369 for which the A004510 workaround should be applied. 370 371 The rest of SVR is either not relevant to the decision 372 of whether the erratum is present (e.g. p2040 versus 373 p2041) or is implied by the build target, which controls 374 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 375 376 See Freescale App Note 4493 for more information about 377 this erratum. 378 379 CONFIG_A003399_NOR_WORKAROUND 380 Enables a workaround for IFC erratum A003399. It is only 381 required during NOR boot. 382 383 CONFIG_A008044_WORKAROUND 384 Enables a workaround for T1040/T1042 erratum A008044. It is only 385 required during NAND boot and valid for Rev 1.0 SoC revision 386 387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 388 389 This is the value to write into CCSR offset 0x18600 390 according to the A004510 workaround. 391 392 CONFIG_SYS_FSL_DSP_DDR_ADDR 393 This value denotes start offset of DDR memory which is 394 connected exclusively to the DSP cores. 395 396 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 397 This value denotes start offset of M2 memory 398 which is directly connected to the DSP core. 399 400 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 401 This value denotes start offset of M3 memory which is directly 402 connected to the DSP core. 403 404 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 405 This value denotes start offset of DSP CCSR space. 406 407 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 408 Single Source Clock is clocking mode present in some of FSL SoC's. 409 In this mode, a single differential clock is used to supply 410 clocks to the sysclock, ddrclock and usbclock. 411 412 CONFIG_SYS_CPC_REINIT_F 413 This CONFIG is defined when the CPC is configured as SRAM at the 414 time of U-Boot entry and is required to be re-initialized. 415 416 CONFIG_DEEP_SLEEP 417 Indicates this SoC supports deep sleep feature. If deep sleep is 418 supported, core will start to execute uboot when wakes up. 419 420- Generic CPU options: 421 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 422 423 Defines the endianess of the CPU. Implementation of those 424 values is arch specific. 425 426 CONFIG_SYS_FSL_DDR 427 Freescale DDR driver in use. This type of DDR controller is 428 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 429 SoCs. 430 431 CONFIG_SYS_FSL_DDR_ADDR 432 Freescale DDR memory-mapped register base. 433 434 CONFIG_SYS_FSL_DDR_EMU 435 Specify emulator support for DDR. Some DDR features such as 436 deskew training are not available. 437 438 CONFIG_SYS_FSL_DDRC_GEN1 439 Freescale DDR1 controller. 440 441 CONFIG_SYS_FSL_DDRC_GEN2 442 Freescale DDR2 controller. 443 444 CONFIG_SYS_FSL_DDRC_GEN3 445 Freescale DDR3 controller. 446 447 CONFIG_SYS_FSL_DDRC_GEN4 448 Freescale DDR4 controller. 449 450 CONFIG_SYS_FSL_DDRC_ARM_GEN3 451 Freescale DDR3 controller for ARM-based SoCs. 452 453 CONFIG_SYS_FSL_DDR1 454 Board config to use DDR1. It can be enabled for SoCs with 455 Freescale DDR1 or DDR2 controllers, depending on the board 456 implemetation. 457 458 CONFIG_SYS_FSL_DDR2 459 Board config to use DDR2. It can be enabled for SoCs with 460 Freescale DDR2 or DDR3 controllers, depending on the board 461 implementation. 462 463 CONFIG_SYS_FSL_DDR3 464 Board config to use DDR3. It can be enabled for SoCs with 465 Freescale DDR3 or DDR3L controllers. 466 467 CONFIG_SYS_FSL_DDR3L 468 Board config to use DDR3L. It can be enabled for SoCs with 469 DDR3L controllers. 470 471 CONFIG_SYS_FSL_DDR4 472 Board config to use DDR4. It can be enabled for SoCs with 473 DDR4 controllers. 474 475 CONFIG_SYS_FSL_IFC_BE 476 Defines the IFC controller register space as Big Endian 477 478 CONFIG_SYS_FSL_IFC_LE 479 Defines the IFC controller register space as Little Endian 480 481 CONFIG_SYS_FSL_IFC_CLK_DIV 482 Defines divider of platform clock(clock input to IFC controller). 483 484 CONFIG_SYS_FSL_LBC_CLK_DIV 485 Defines divider of platform clock(clock input to eLBC controller). 486 487 CONFIG_SYS_FSL_PBL_PBI 488 It enables addition of RCW (Power on reset configuration) in built image. 489 Please refer doc/README.pblimage for more details 490 491 CONFIG_SYS_FSL_PBL_RCW 492 It adds PBI(pre-boot instructions) commands in u-boot build image. 493 PBI commands can be used to configure SoC before it starts the execution. 494 Please refer doc/README.pblimage for more details 495 496 CONFIG_SPL_FSL_PBL 497 It adds a target to create boot binary having SPL binary in PBI format 498 concatenated with u-boot binary. 499 500 CONFIG_SYS_FSL_DDR_BE 501 Defines the DDR controller register space as Big Endian 502 503 CONFIG_SYS_FSL_DDR_LE 504 Defines the DDR controller register space as Little Endian 505 506 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 507 Physical address from the view of DDR controllers. It is the 508 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 509 it could be different for ARM SoCs. 510 511 CONFIG_SYS_FSL_DDR_INTLV_256B 512 DDR controller interleaving on 256-byte. This is a special 513 interleaving mode, handled by Dickens for Freescale layerscape 514 SoCs with ARM core. 515 516 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 517 Number of controllers used as main memory. 518 519 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 520 Number of controllers used for other than main memory. 521 522 CONFIG_SYS_FSL_HAS_DP_DDR 523 Defines the SoC has DP-DDR used for DPAA. 524 525 CONFIG_SYS_FSL_SEC_BE 526 Defines the SEC controller register space as Big Endian 527 528 CONFIG_SYS_FSL_SEC_LE 529 Defines the SEC controller register space as Little Endian 530 531- MIPS CPU options: 532 CONFIG_SYS_INIT_SP_OFFSET 533 534 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 535 pointer. This is needed for the temporary stack before 536 relocation. 537 538 CONFIG_SYS_MIPS_CACHE_MODE 539 540 Cache operation mode for the MIPS CPU. 541 See also arch/mips/include/asm/mipsregs.h. 542 Possible values are: 543 CONF_CM_CACHABLE_NO_WA 544 CONF_CM_CACHABLE_WA 545 CONF_CM_UNCACHED 546 CONF_CM_CACHABLE_NONCOHERENT 547 CONF_CM_CACHABLE_CE 548 CONF_CM_CACHABLE_COW 549 CONF_CM_CACHABLE_CUW 550 CONF_CM_CACHABLE_ACCELERATED 551 552 CONFIG_SYS_XWAY_EBU_BOOTCFG 553 554 Special option for Lantiq XWAY SoCs for booting from NOR flash. 555 See also arch/mips/cpu/mips32/start.S. 556 557 CONFIG_XWAY_SWAP_BYTES 558 559 Enable compilation of tools/xway-swap-bytes needed for Lantiq 560 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 561 be swapped if a flash programmer is used. 562 563- ARM options: 564 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 565 566 Select high exception vectors of the ARM core, e.g., do not 567 clear the V bit of the c1 register of CP15. 568 569 COUNTER_FREQUENCY 570 Generic timer clock source frequency. 571 572 COUNTER_FREQUENCY_REAL 573 Generic timer clock source frequency if the real clock is 574 different from COUNTER_FREQUENCY, and can only be determined 575 at run time. 576 577- Tegra SoC options: 578 CONFIG_TEGRA_SUPPORT_NON_SECURE 579 580 Support executing U-Boot in non-secure (NS) mode. Certain 581 impossible actions will be skipped if the CPU is in NS mode, 582 such as ARM architectural timer initialization. 583 584- Linux Kernel Interface: 585 CONFIG_CLOCKS_IN_MHZ 586 587 U-Boot stores all clock information in Hz 588 internally. For binary compatibility with older Linux 589 kernels (which expect the clocks passed in the 590 bd_info data to be in MHz) the environment variable 591 "clocks_in_mhz" can be defined so that U-Boot 592 converts clock data to MHZ before passing it to the 593 Linux kernel. 594 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 595 "clocks_in_mhz=1" is automatically included in the 596 default environment. 597 598 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 599 600 When transferring memsize parameter to Linux, some versions 601 expect it to be in bytes, others in MB. 602 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 603 604 CONFIG_OF_LIBFDT 605 606 New kernel versions are expecting firmware settings to be 607 passed using flattened device trees (based on open firmware 608 concepts). 609 610 CONFIG_OF_LIBFDT 611 * New libfdt-based support 612 * Adds the "fdt" command 613 * The bootm command automatically updates the fdt 614 615 OF_TBCLK - The timebase frequency. 616 OF_STDOUT_PATH - The path to the console device 617 618 boards with QUICC Engines require OF_QE to set UCC MAC 619 addresses 620 621 CONFIG_OF_BOARD_SETUP 622 623 Board code has addition modification that it wants to make 624 to the flat device tree before handing it off to the kernel 625 626 CONFIG_OF_SYSTEM_SETUP 627 628 Other code has addition modification that it wants to make 629 to the flat device tree before handing it off to the kernel. 630 This causes ft_system_setup() to be called before booting 631 the kernel. 632 633 CONFIG_OF_IDE_FIXUP 634 635 U-Boot can detect if an IDE device is present or not. 636 If not, and this new config option is activated, U-Boot 637 removes the ATA node from the DTS before booting Linux, 638 so the Linux IDE driver does not probe the device and 639 crash. This is needed for buggy hardware (uc101) where 640 no pull down resistor is connected to the signal IDE5V_DD7. 641 642 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 643 644 This setting is mandatory for all boards that have only one 645 machine type and must be used to specify the machine type 646 number as it appears in the ARM machine registry 647 (see http://www.arm.linux.org.uk/developer/machines/). 648 Only boards that have multiple machine types supported 649 in a single configuration file and the machine type is 650 runtime discoverable, do not have to use this setting. 651 652- vxWorks boot parameters: 653 654 bootvx constructs a valid bootline using the following 655 environments variables: bootdev, bootfile, ipaddr, netmask, 656 serverip, gatewayip, hostname, othbootargs. 657 It loads the vxWorks image pointed bootfile. 658 659 Note: If a "bootargs" environment is defined, it will overwride 660 the defaults discussed just above. 661 662- Cache Configuration: 663 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 664 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 665 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 666 667- Cache Configuration for ARM: 668 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 669 controller 670 CONFIG_SYS_PL310_BASE - Physical base address of PL310 671 controller register space 672 673- Serial Ports: 674 CONFIG_PL010_SERIAL 675 676 Define this if you want support for Amba PrimeCell PL010 UARTs. 677 678 CONFIG_PL011_SERIAL 679 680 Define this if you want support for Amba PrimeCell PL011 UARTs. 681 682 CONFIG_PL011_CLOCK 683 684 If you have Amba PrimeCell PL011 UARTs, set this variable to 685 the clock speed of the UARTs. 686 687 CONFIG_PL01x_PORTS 688 689 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 690 define this to a list of base addresses for each (supported) 691 port. See e.g. include/configs/versatile.h 692 693 CONFIG_SERIAL_HW_FLOW_CONTROL 694 695 Define this variable to enable hw flow control in serial driver. 696 Current user of this option is drivers/serial/nsl16550.c driver 697 698- Console Baudrate: 699 CONFIG_BAUDRATE - in bps 700 Select one of the baudrates listed in 701 CONFIG_SYS_BAUDRATE_TABLE, see below. 702 703- Autoboot Command: 704 CONFIG_BOOTCOMMAND 705 Only needed when CONFIG_BOOTDELAY is enabled; 706 define a command string that is automatically executed 707 when no character is read on the console interface 708 within "Boot Delay" after reset. 709 710 CONFIG_RAMBOOT and CONFIG_NFSBOOT 711 The value of these goes into the environment as 712 "ramboot" and "nfsboot" respectively, and can be used 713 as a convenience, when switching between booting from 714 RAM and NFS. 715 716- Pre-Boot Commands: 717 CONFIG_PREBOOT 718 719 When this option is #defined, the existence of the 720 environment variable "preboot" will be checked 721 immediately before starting the CONFIG_BOOTDELAY 722 countdown and/or running the auto-boot command resp. 723 entering interactive mode. 724 725 This feature is especially useful when "preboot" is 726 automatically generated or modified. For an example 727 see the LWMON board specific code: here "preboot" is 728 modified when the user holds down a certain 729 combination of keys on the (special) keyboard when 730 booting the systems 731 732- Serial Download Echo Mode: 733 CONFIG_LOADS_ECHO 734 If defined to 1, all characters received during a 735 serial download (using the "loads" command) are 736 echoed back. This might be needed by some terminal 737 emulations (like "cu"), but may as well just take 738 time on others. This setting #define's the initial 739 value of the "loads_echo" environment variable. 740 741- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 742 CONFIG_KGDB_BAUDRATE 743 Select one of the baudrates listed in 744 CONFIG_SYS_BAUDRATE_TABLE, see below. 745 746- Removal of commands 747 If no commands are needed to boot, you can disable 748 CONFIG_CMDLINE to remove them. In this case, the command line 749 will not be available, and when U-Boot wants to execute the 750 boot command (on start-up) it will call board_run_command() 751 instead. This can reduce image size significantly for very 752 simple boot procedures. 753 754- Regular expression support: 755 CONFIG_REGEX 756 If this variable is defined, U-Boot is linked against 757 the SLRE (Super Light Regular Expression) library, 758 which adds regex support to some commands, as for 759 example "env grep" and "setexpr". 760 761- Device tree: 762 CONFIG_OF_CONTROL 763 If this variable is defined, U-Boot will use a device tree 764 to configure its devices, instead of relying on statically 765 compiled #defines in the board file. This option is 766 experimental and only available on a few boards. The device 767 tree is available in the global data as gd->fdt_blob. 768 769 U-Boot needs to get its device tree from somewhere. This can 770 be done using one of the three options below: 771 772 CONFIG_OF_EMBED 773 If this variable is defined, U-Boot will embed a device tree 774 binary in its image. This device tree file should be in the 775 board directory and called <soc>-<board>.dts. The binary file 776 is then picked up in board_init_f() and made available through 777 the global data structure as gd->fdt_blob. 778 779 CONFIG_OF_SEPARATE 780 If this variable is defined, U-Boot will build a device tree 781 binary. It will be called u-boot.dtb. Architecture-specific 782 code will locate it at run-time. Generally this works by: 783 784 cat u-boot.bin u-boot.dtb >image.bin 785 786 and in fact, U-Boot does this for you, creating a file called 787 u-boot-dtb.bin which is useful in the common case. You can 788 still use the individual files if you need something more 789 exotic. 790 791 CONFIG_OF_BOARD 792 If this variable is defined, U-Boot will use the device tree 793 provided by the board at runtime instead of embedding one with 794 the image. Only boards defining board_fdt_blob_setup() support 795 this option (see include/fdtdec.h file). 796 797- Watchdog: 798 CONFIG_WATCHDOG 799 If this variable is defined, it enables watchdog 800 support for the SoC. There must be support in the SoC 801 specific code for a watchdog. For the 8xx 802 CPUs, the SIU Watchdog feature is enabled in the SYPCR 803 register. When supported for a specific SoC is 804 available, then no further board specific code should 805 be needed to use it. 806 807 CONFIG_HW_WATCHDOG 808 When using a watchdog circuitry external to the used 809 SoC, then define this variable and provide board 810 specific code for the "hw_watchdog_reset" function. 811 812 CONFIG_AT91_HW_WDT_TIMEOUT 813 specify the timeout in seconds. default 2 seconds. 814 815- U-Boot Version: 816 CONFIG_VERSION_VARIABLE 817 If this variable is defined, an environment variable 818 named "ver" is created by U-Boot showing the U-Boot 819 version as printed by the "version" command. 820 Any change to this variable will be reverted at the 821 next reset. 822 823- Real-Time Clock: 824 825 When CONFIG_CMD_DATE is selected, the type of the RTC 826 has to be selected, too. Define exactly one of the 827 following options: 828 829 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 830 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 831 CONFIG_RTC_MC146818 - use MC146818 RTC 832 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 833 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 834 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 835 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 836 CONFIG_RTC_DS164x - use Dallas DS164x RTC 837 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 838 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 839 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 840 CONFIG_SYS_RV3029_TCR - enable trickle charger on 841 RV3029 RTC. 842 843 Note that if the RTC uses I2C, then the I2C interface 844 must also be configured. See I2C Support, below. 845 846- GPIO Support: 847 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 848 849 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 850 chip-ngpio pairs that tell the PCA953X driver the number of 851 pins supported by a particular chip. 852 853 Note that if the GPIO device uses I2C, then the I2C interface 854 must also be configured. See I2C Support, below. 855 856- I/O tracing: 857 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 858 accesses and can checksum them or write a list of them out 859 to memory. See the 'iotrace' command for details. This is 860 useful for testing device drivers since it can confirm that 861 the driver behaves the same way before and after a code 862 change. Currently this is supported on sandbox and arm. To 863 add support for your architecture, add '#include <iotrace.h>' 864 to the bottom of arch/<arch>/include/asm/io.h and test. 865 866 Example output from the 'iotrace stats' command is below. 867 Note that if the trace buffer is exhausted, the checksum will 868 still continue to operate. 869 870 iotrace is enabled 871 Start: 10000000 (buffer start address) 872 Size: 00010000 (buffer size) 873 Offset: 00000120 (current buffer offset) 874 Output: 10000120 (start + offset) 875 Count: 00000018 (number of trace records) 876 CRC32: 9526fb66 (CRC32 of all trace records) 877 878- Timestamp Support: 879 880 When CONFIG_TIMESTAMP is selected, the timestamp 881 (date and time) of an image is printed by image 882 commands like bootm or iminfo. This option is 883 automatically enabled when you select CONFIG_CMD_DATE . 884 885- Partition Labels (disklabels) Supported: 886 Zero or more of the following: 887 CONFIG_MAC_PARTITION Apple's MacOS partition table. 888 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 889 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 890 bootloader. Note 2TB partition limit; see 891 disk/part_efi.c 892 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 893 894 If IDE or SCSI support is enabled (CONFIG_IDE or 895 CONFIG_SCSI) you must configure support for at 896 least one non-MTD partition type as well. 897 898- IDE Reset method: 899 CONFIG_IDE_RESET_ROUTINE - this is defined in several 900 board configurations files but used nowhere! 901 902 CONFIG_IDE_RESET - is this is defined, IDE Reset will 903 be performed by calling the function 904 ide_set_reset(int reset) 905 which has to be defined in a board specific file 906 907- ATAPI Support: 908 CONFIG_ATAPI 909 910 Set this to enable ATAPI support. 911 912- LBA48 Support 913 CONFIG_LBA48 914 915 Set this to enable support for disks larger than 137GB 916 Also look at CONFIG_SYS_64BIT_LBA. 917 Whithout these , LBA48 support uses 32bit variables and will 'only' 918 support disks up to 2.1TB. 919 920 CONFIG_SYS_64BIT_LBA: 921 When enabled, makes the IDE subsystem use 64bit sector addresses. 922 Default is 32bit. 923 924- SCSI Support: 925 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 926 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 927 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 928 maximum numbers of LUNs, SCSI ID's and target 929 devices. 930 931 The environment variable 'scsidevs' is set to the number of 932 SCSI devices found during the last scan. 933 934- NETWORK Support (PCI): 935 CONFIG_E1000 936 Support for Intel 8254x/8257x gigabit chips. 937 938 CONFIG_E1000_SPI 939 Utility code for direct access to the SPI bus on Intel 8257x. 940 This does not do anything useful unless you set at least one 941 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 942 943 CONFIG_E1000_SPI_GENERIC 944 Allow generic access to the SPI bus on the Intel 8257x, for 945 example with the "sspi" command. 946 947 CONFIG_EEPRO100 948 Support for Intel 82557/82559/82559ER chips. 949 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 950 write routine for first time initialisation. 951 952 CONFIG_TULIP 953 Support for Digital 2114x chips. 954 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 955 modem chip initialisation (KS8761/QS6611). 956 957 CONFIG_NATSEMI 958 Support for National dp83815 chips. 959 960 CONFIG_NS8382X 961 Support for National dp8382[01] gigabit chips. 962 963- NETWORK Support (other): 964 965 CONFIG_DRIVER_AT91EMAC 966 Support for AT91RM9200 EMAC. 967 968 CONFIG_RMII 969 Define this to use reduced MII inteface 970 971 CONFIG_DRIVER_AT91EMAC_QUIET 972 If this defined, the driver is quiet. 973 The driver doen't show link status messages. 974 975 CONFIG_CALXEDA_XGMAC 976 Support for the Calxeda XGMAC device 977 978 CONFIG_LAN91C96 979 Support for SMSC's LAN91C96 chips. 980 981 CONFIG_LAN91C96_USE_32_BIT 982 Define this to enable 32 bit addressing 983 984 CONFIG_SMC91111 985 Support for SMSC's LAN91C111 chip 986 987 CONFIG_SMC91111_BASE 988 Define this to hold the physical address 989 of the device (I/O space) 990 991 CONFIG_SMC_USE_32_BIT 992 Define this if data bus is 32 bits 993 994 CONFIG_SMC_USE_IOFUNCS 995 Define this to use i/o functions instead of macros 996 (some hardware wont work with macros) 997 998 CONFIG_DRIVER_TI_EMAC 999 Support for davinci emac 1000 1001 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1002 Define this if you have more then 3 PHYs. 1003 1004 CONFIG_FTGMAC100 1005 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1006 1007 CONFIG_FTGMAC100_EGIGA 1008 Define this to use GE link update with gigabit PHY. 1009 Define this if FTGMAC100 is connected to gigabit PHY. 1010 If your system has 10/100 PHY only, it might not occur 1011 wrong behavior. Because PHY usually return timeout or 1012 useless data when polling gigabit status and gigabit 1013 control registers. This behavior won't affect the 1014 correctnessof 10/100 link speed update. 1015 1016 CONFIG_SH_ETHER 1017 Support for Renesas on-chip Ethernet controller 1018 1019 CONFIG_SH_ETHER_USE_PORT 1020 Define the number of ports to be used 1021 1022 CONFIG_SH_ETHER_PHY_ADDR 1023 Define the ETH PHY's address 1024 1025 CONFIG_SH_ETHER_CACHE_WRITEBACK 1026 If this option is set, the driver enables cache flush. 1027 1028- PWM Support: 1029 CONFIG_PWM_IMX 1030 Support for PWM module on the imx6. 1031 1032- TPM Support: 1033 CONFIG_TPM 1034 Support TPM devices. 1035 1036 CONFIG_TPM_TIS_INFINEON 1037 Support for Infineon i2c bus TPM devices. Only one device 1038 per system is supported at this time. 1039 1040 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1041 Define the burst count bytes upper limit 1042 1043 CONFIG_TPM_ST33ZP24 1044 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1045 1046 CONFIG_TPM_ST33ZP24_I2C 1047 Support for STMicroelectronics ST33ZP24 I2C devices. 1048 Requires TPM_ST33ZP24 and I2C. 1049 1050 CONFIG_TPM_ST33ZP24_SPI 1051 Support for STMicroelectronics ST33ZP24 SPI devices. 1052 Requires TPM_ST33ZP24 and SPI. 1053 1054 CONFIG_TPM_ATMEL_TWI 1055 Support for Atmel TWI TPM device. Requires I2C support. 1056 1057 CONFIG_TPM_TIS_LPC 1058 Support for generic parallel port TPM devices. Only one device 1059 per system is supported at this time. 1060 1061 CONFIG_TPM_TIS_BASE_ADDRESS 1062 Base address where the generic TPM device is mapped 1063 to. Contemporary x86 systems usually map it at 1064 0xfed40000. 1065 1066 CONFIG_TPM 1067 Define this to enable the TPM support library which provides 1068 functional interfaces to some TPM commands. 1069 Requires support for a TPM device. 1070 1071 CONFIG_TPM_AUTH_SESSIONS 1072 Define this to enable authorized functions in the TPM library. 1073 Requires CONFIG_TPM and CONFIG_SHA1. 1074 1075- USB Support: 1076 At the moment only the UHCI host controller is 1077 supported (PIP405, MIP405); define 1078 CONFIG_USB_UHCI to enable it. 1079 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1080 and define CONFIG_USB_STORAGE to enable the USB 1081 storage devices. 1082 Note: 1083 Supported are USB Keyboards and USB Floppy drives 1084 (TEAC FD-05PUB). 1085 1086 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1087 txfilltuning field in the EHCI controller on reset. 1088 1089 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1090 HW module registers. 1091 1092- USB Device: 1093 Define the below if you wish to use the USB console. 1094 Once firmware is rebuilt from a serial console issue the 1095 command "setenv stdin usbtty; setenv stdout usbtty" and 1096 attach your USB cable. The Unix command "dmesg" should print 1097 it has found a new device. The environment variable usbtty 1098 can be set to gserial or cdc_acm to enable your device to 1099 appear to a USB host as a Linux gserial device or a 1100 Common Device Class Abstract Control Model serial device. 1101 If you select usbtty = gserial you should be able to enumerate 1102 a Linux host by 1103 # modprobe usbserial vendor=0xVendorID product=0xProductID 1104 else if using cdc_acm, simply setting the environment 1105 variable usbtty to be cdc_acm should suffice. The following 1106 might be defined in YourBoardName.h 1107 1108 CONFIG_USB_DEVICE 1109 Define this to build a UDC device 1110 1111 CONFIG_USB_TTY 1112 Define this to have a tty type of device available to 1113 talk to the UDC device 1114 1115 CONFIG_USBD_HS 1116 Define this to enable the high speed support for usb 1117 device and usbtty. If this feature is enabled, a routine 1118 int is_usbd_high_speed(void) 1119 also needs to be defined by the driver to dynamically poll 1120 whether the enumeration has succeded at high speed or full 1121 speed. 1122 1123 CONFIG_SYS_CONSOLE_IS_IN_ENV 1124 Define this if you want stdin, stdout &/or stderr to 1125 be set to usbtty. 1126 1127 If you have a USB-IF assigned VendorID then you may wish to 1128 define your own vendor specific values either in BoardName.h 1129 or directly in usbd_vendor_info.h. If you don't define 1130 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1131 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1132 should pretend to be a Linux device to it's target host. 1133 1134 CONFIG_USBD_MANUFACTURER 1135 Define this string as the name of your company for 1136 - CONFIG_USBD_MANUFACTURER "my company" 1137 1138 CONFIG_USBD_PRODUCT_NAME 1139 Define this string as the name of your product 1140 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1141 1142 CONFIG_USBD_VENDORID 1143 Define this as your assigned Vendor ID from the USB 1144 Implementors Forum. This *must* be a genuine Vendor ID 1145 to avoid polluting the USB namespace. 1146 - CONFIG_USBD_VENDORID 0xFFFF 1147 1148 CONFIG_USBD_PRODUCTID 1149 Define this as the unique Product ID 1150 for your device 1151 - CONFIG_USBD_PRODUCTID 0xFFFF 1152 1153- ULPI Layer Support: 1154 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1155 the generic ULPI layer. The generic layer accesses the ULPI PHY 1156 via the platform viewport, so you need both the genric layer and 1157 the viewport enabled. Currently only Chipidea/ARC based 1158 viewport is supported. 1159 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1160 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1161 If your ULPI phy needs a different reference clock than the 1162 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1163 the appropriate value in Hz. 1164 1165- MMC Support: 1166 The MMC controller on the Intel PXA is supported. To 1167 enable this define CONFIG_MMC. The MMC can be 1168 accessed from the boot prompt by mapping the device 1169 to physical memory similar to flash. Command line is 1170 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1171 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1172 1173 CONFIG_SH_MMCIF 1174 Support for Renesas on-chip MMCIF controller 1175 1176 CONFIG_SH_MMCIF_ADDR 1177 Define the base address of MMCIF registers 1178 1179 CONFIG_SH_MMCIF_CLK 1180 Define the clock frequency for MMCIF 1181 1182 CONFIG_SUPPORT_EMMC_BOOT 1183 Enable some additional features of the eMMC boot partitions. 1184 1185 CONFIG_SUPPORT_EMMC_RPMB 1186 Enable the commands for reading, writing and programming the 1187 key for the Replay Protection Memory Block partition in eMMC. 1188 1189- USB Device Firmware Update (DFU) class support: 1190 CONFIG_DFU_OVER_USB 1191 This enables the USB portion of the DFU USB class 1192 1193 CONFIG_DFU_MMC 1194 This enables support for exposing (e)MMC devices via DFU. 1195 1196 CONFIG_DFU_NAND 1197 This enables support for exposing NAND devices via DFU. 1198 1199 CONFIG_DFU_RAM 1200 This enables support for exposing RAM via DFU. 1201 Note: DFU spec refer to non-volatile memory usage, but 1202 allow usages beyond the scope of spec - here RAM usage, 1203 one that would help mostly the developer. 1204 1205 CONFIG_SYS_DFU_DATA_BUF_SIZE 1206 Dfu transfer uses a buffer before writing data to the 1207 raw storage device. Make the size (in bytes) of this buffer 1208 configurable. The size of this buffer is also configurable 1209 through the "dfu_bufsiz" environment variable. 1210 1211 CONFIG_SYS_DFU_MAX_FILE_SIZE 1212 When updating files rather than the raw storage device, 1213 we use a static buffer to copy the file into and then write 1214 the buffer once we've been given the whole file. Define 1215 this to the maximum filesize (in bytes) for the buffer. 1216 Default is 4 MiB if undefined. 1217 1218 DFU_DEFAULT_POLL_TIMEOUT 1219 Poll timeout [ms], is the timeout a device can send to the 1220 host. The host must wait for this timeout before sending 1221 a subsequent DFU_GET_STATUS request to the device. 1222 1223 DFU_MANIFEST_POLL_TIMEOUT 1224 Poll timeout [ms], which the device sends to the host when 1225 entering dfuMANIFEST state. Host waits this timeout, before 1226 sending again an USB request to the device. 1227 1228- Journaling Flash filesystem support: 1229 CONFIG_JFFS2_NAND 1230 Define these for a default partition on a NAND device 1231 1232 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1233 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1234 Define these for a default partition on a NOR device 1235 1236- Keyboard Support: 1237 See Kconfig help for available keyboard drivers. 1238 1239 CONFIG_KEYBOARD 1240 1241 Define this to enable a custom keyboard support. 1242 This simply calls drv_keyboard_init() which must be 1243 defined in your board-specific files. This option is deprecated 1244 and is only used by novena. For new boards, use driver model 1245 instead. 1246 1247- Video support: 1248 CONFIG_FSL_DIU_FB 1249 Enable the Freescale DIU video driver. Reference boards for 1250 SOCs that have a DIU should define this macro to enable DIU 1251 support, and should also define these other macros: 1252 1253 CONFIG_SYS_DIU_ADDR 1254 CONFIG_VIDEO 1255 CONFIG_CFB_CONSOLE 1256 CONFIG_VIDEO_SW_CURSOR 1257 CONFIG_VGA_AS_SINGLE_DEVICE 1258 CONFIG_VIDEO_LOGO 1259 CONFIG_VIDEO_BMP_LOGO 1260 1261 The DIU driver will look for the 'video-mode' environment 1262 variable, and if defined, enable the DIU as a console during 1263 boot. See the documentation file doc/README.video for a 1264 description of this variable. 1265 1266- LCD Support: CONFIG_LCD 1267 1268 Define this to enable LCD support (for output to LCD 1269 display); also select one of the supported displays 1270 by defining one of these: 1271 1272 CONFIG_ATMEL_LCD: 1273 1274 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1275 1276 CONFIG_NEC_NL6448AC33: 1277 1278 NEC NL6448AC33-18. Active, color, single scan. 1279 1280 CONFIG_NEC_NL6448BC20 1281 1282 NEC NL6448BC20-08. 6.5", 640x480. 1283 Active, color, single scan. 1284 1285 CONFIG_NEC_NL6448BC33_54 1286 1287 NEC NL6448BC33-54. 10.4", 640x480. 1288 Active, color, single scan. 1289 1290 CONFIG_SHARP_16x9 1291 1292 Sharp 320x240. Active, color, single scan. 1293 It isn't 16x9, and I am not sure what it is. 1294 1295 CONFIG_SHARP_LQ64D341 1296 1297 Sharp LQ64D341 display, 640x480. 1298 Active, color, single scan. 1299 1300 CONFIG_HLD1045 1301 1302 HLD1045 display, 640x480. 1303 Active, color, single scan. 1304 1305 CONFIG_OPTREX_BW 1306 1307 Optrex CBL50840-2 NF-FW 99 22 M5 1308 or 1309 Hitachi LMG6912RPFC-00T 1310 or 1311 Hitachi SP14Q002 1312 1313 320x240. Black & white. 1314 1315 CONFIG_LCD_ALIGNMENT 1316 1317 Normally the LCD is page-aligned (typically 4KB). If this is 1318 defined then the LCD will be aligned to this value instead. 1319 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1320 here, since it is cheaper to change data cache settings on 1321 a per-section basis. 1322 1323 1324 CONFIG_LCD_ROTATION 1325 1326 Sometimes, for example if the display is mounted in portrait 1327 mode or even if it's mounted landscape but rotated by 180degree, 1328 we need to rotate our content of the display relative to the 1329 framebuffer, so that user can read the messages which are 1330 printed out. 1331 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1332 initialized with a given rotation from "vl_rot" out of 1333 "vidinfo_t" which is provided by the board specific code. 1334 The value for vl_rot is coded as following (matching to 1335 fbcon=rotate:<n> linux-kernel commandline): 1336 0 = no rotation respectively 0 degree 1337 1 = 90 degree rotation 1338 2 = 180 degree rotation 1339 3 = 270 degree rotation 1340 1341 If CONFIG_LCD_ROTATION is not defined, the console will be 1342 initialized with 0degree rotation. 1343 1344 CONFIG_LCD_BMP_RLE8 1345 1346 Support drawing of RLE8-compressed bitmaps on the LCD. 1347 1348 CONFIG_I2C_EDID 1349 1350 Enables an 'i2c edid' command which can read EDID 1351 information over I2C from an attached LCD display. 1352 1353- Splash Screen Support: CONFIG_SPLASH_SCREEN 1354 1355 If this option is set, the environment is checked for 1356 a variable "splashimage". If found, the usual display 1357 of logo, copyright and system information on the LCD 1358 is suppressed and the BMP image at the address 1359 specified in "splashimage" is loaded instead. The 1360 console is redirected to the "nulldev", too. This 1361 allows for a "silent" boot where a splash screen is 1362 loaded very quickly after power-on. 1363 1364 CONFIG_SPLASHIMAGE_GUARD 1365 1366 If this option is set, then U-Boot will prevent the environment 1367 variable "splashimage" from being set to a problematic address 1368 (see doc/README.displaying-bmps). 1369 This option is useful for targets where, due to alignment 1370 restrictions, an improperly aligned BMP image will cause a data 1371 abort. If you think you will not have problems with unaligned 1372 accesses (for example because your toolchain prevents them) 1373 there is no need to set this option. 1374 1375 CONFIG_SPLASH_SCREEN_ALIGN 1376 1377 If this option is set the splash image can be freely positioned 1378 on the screen. Environment variable "splashpos" specifies the 1379 position as "x,y". If a positive number is given it is used as 1380 number of pixel from left/top. If a negative number is given it 1381 is used as number of pixel from right/bottom. You can also 1382 specify 'm' for centering the image. 1383 1384 Example: 1385 setenv splashpos m,m 1386 => image at center of screen 1387 1388 setenv splashpos 30,20 1389 => image at x = 30 and y = 20 1390 1391 setenv splashpos -10,m 1392 => vertically centered image 1393 at x = dspWidth - bmpWidth - 9 1394 1395- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1396 1397 If this option is set, additionally to standard BMP 1398 images, gzipped BMP images can be displayed via the 1399 splashscreen support or the bmp command. 1400 1401- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1402 1403 If this option is set, 8-bit RLE compressed BMP images 1404 can be displayed via the splashscreen support or the 1405 bmp command. 1406 1407- Compression support: 1408 CONFIG_GZIP 1409 1410 Enabled by default to support gzip compressed images. 1411 1412 CONFIG_BZIP2 1413 1414 If this option is set, support for bzip2 compressed 1415 images is included. If not, only uncompressed and gzip 1416 compressed images are supported. 1417 1418 NOTE: the bzip2 algorithm requires a lot of RAM, so 1419 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1420 be at least 4MB. 1421 1422- MII/PHY support: 1423 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1424 1425 The clock frequency of the MII bus 1426 1427 CONFIG_PHY_RESET_DELAY 1428 1429 Some PHY like Intel LXT971A need extra delay after 1430 reset before any MII register access is possible. 1431 For such PHY, set this option to the usec delay 1432 required. (minimum 300usec for LXT971A) 1433 1434 CONFIG_PHY_CMD_DELAY (ppc4xx) 1435 1436 Some PHY like Intel LXT971A need extra delay after 1437 command issued before MII status register can be read 1438 1439- IP address: 1440 CONFIG_IPADDR 1441 1442 Define a default value for the IP address to use for 1443 the default Ethernet interface, in case this is not 1444 determined through e.g. bootp. 1445 (Environment variable "ipaddr") 1446 1447- Server IP address: 1448 CONFIG_SERVERIP 1449 1450 Defines a default value for the IP address of a TFTP 1451 server to contact when using the "tftboot" command. 1452 (Environment variable "serverip") 1453 1454 CONFIG_KEEP_SERVERADDR 1455 1456 Keeps the server's MAC address, in the env 'serveraddr' 1457 for passing to bootargs (like Linux's netconsole option) 1458 1459- Gateway IP address: 1460 CONFIG_GATEWAYIP 1461 1462 Defines a default value for the IP address of the 1463 default router where packets to other networks are 1464 sent to. 1465 (Environment variable "gatewayip") 1466 1467- Subnet mask: 1468 CONFIG_NETMASK 1469 1470 Defines a default value for the subnet mask (or 1471 routing prefix) which is used to determine if an IP 1472 address belongs to the local subnet or needs to be 1473 forwarded through a router. 1474 (Environment variable "netmask") 1475 1476- Multicast TFTP Mode: 1477 CONFIG_MCAST_TFTP 1478 1479 Defines whether you want to support multicast TFTP as per 1480 rfc-2090; for example to work with atftp. Lets lots of targets 1481 tftp down the same boot image concurrently. Note: the Ethernet 1482 driver in use must provide a function: mcast() to join/leave a 1483 multicast group. 1484 1485- BOOTP Recovery Mode: 1486 CONFIG_BOOTP_RANDOM_DELAY 1487 1488 If you have many targets in a network that try to 1489 boot using BOOTP, you may want to avoid that all 1490 systems send out BOOTP requests at precisely the same 1491 moment (which would happen for instance at recovery 1492 from a power failure, when all systems will try to 1493 boot, thus flooding the BOOTP server. Defining 1494 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1495 inserted before sending out BOOTP requests. The 1496 following delays are inserted then: 1497 1498 1st BOOTP request: delay 0 ... 1 sec 1499 2nd BOOTP request: delay 0 ... 2 sec 1500 3rd BOOTP request: delay 0 ... 4 sec 1501 4th and following 1502 BOOTP requests: delay 0 ... 8 sec 1503 1504 CONFIG_BOOTP_ID_CACHE_SIZE 1505 1506 BOOTP packets are uniquely identified using a 32-bit ID. The 1507 server will copy the ID from client requests to responses and 1508 U-Boot will use this to determine if it is the destination of 1509 an incoming response. Some servers will check that addresses 1510 aren't in use before handing them out (usually using an ARP 1511 ping) and therefore take up to a few hundred milliseconds to 1512 respond. Network congestion may also influence the time it 1513 takes for a response to make it back to the client. If that 1514 time is too long, U-Boot will retransmit requests. In order 1515 to allow earlier responses to still be accepted after these 1516 retransmissions, U-Boot's BOOTP client keeps a small cache of 1517 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1518 cache. The default is to keep IDs for up to four outstanding 1519 requests. Increasing this will allow U-Boot to accept offers 1520 from a BOOTP client in networks with unusually high latency. 1521 1522- DHCP Advanced Options: 1523 You can fine tune the DHCP functionality by defining 1524 CONFIG_BOOTP_* symbols: 1525 1526 CONFIG_BOOTP_NISDOMAIN 1527 CONFIG_BOOTP_BOOTFILESIZE 1528 CONFIG_BOOTP_SEND_HOSTNAME 1529 CONFIG_BOOTP_NTPSERVER 1530 CONFIG_BOOTP_TIMEOFFSET 1531 CONFIG_BOOTP_VENDOREX 1532 CONFIG_BOOTP_MAY_FAIL 1533 1534 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1535 environment variable, not the BOOTP server. 1536 1537 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1538 after the configured retry count, the call will fail 1539 instead of starting over. This can be used to fail over 1540 to Link-local IP address configuration if the DHCP server 1541 is not available. 1542 1543 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1544 to do a dynamic update of a DNS server. To do this, they 1545 need the hostname of the DHCP requester. 1546 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1547 of the "hostname" environment variable is passed as 1548 option 12 to the DHCP server. 1549 1550 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1551 1552 A 32bit value in microseconds for a delay between 1553 receiving a "DHCP Offer" and sending the "DHCP Request". 1554 This fixes a problem with certain DHCP servers that don't 1555 respond 100% of the time to a "DHCP request". E.g. On an 1556 AT91RM9200 processor running at 180MHz, this delay needed 1557 to be *at least* 15,000 usec before a Windows Server 2003 1558 DHCP server would reply 100% of the time. I recommend at 1559 least 50,000 usec to be safe. The alternative is to hope 1560 that one of the retries will be successful but note that 1561 the DHCP timeout and retry process takes a longer than 1562 this delay. 1563 1564 - Link-local IP address negotiation: 1565 Negotiate with other link-local clients on the local network 1566 for an address that doesn't require explicit configuration. 1567 This is especially useful if a DHCP server cannot be guaranteed 1568 to exist in all environments that the device must operate. 1569 1570 See doc/README.link-local for more information. 1571 1572 - MAC address from environment variables 1573 1574 FDT_SEQ_MACADDR_FROM_ENV 1575 1576 Fix-up device tree with MAC addresses fetched sequentially from 1577 environment variables. This config work on assumption that 1578 non-usable ethernet node of device-tree are either not present 1579 or their status has been marked as "disabled". 1580 1581 - CDP Options: 1582 CONFIG_CDP_DEVICE_ID 1583 1584 The device id used in CDP trigger frames. 1585 1586 CONFIG_CDP_DEVICE_ID_PREFIX 1587 1588 A two character string which is prefixed to the MAC address 1589 of the device. 1590 1591 CONFIG_CDP_PORT_ID 1592 1593 A printf format string which contains the ascii name of 1594 the port. Normally is set to "eth%d" which sets 1595 eth0 for the first Ethernet, eth1 for the second etc. 1596 1597 CONFIG_CDP_CAPABILITIES 1598 1599 A 32bit integer which indicates the device capabilities; 1600 0x00000010 for a normal host which does not forwards. 1601 1602 CONFIG_CDP_VERSION 1603 1604 An ascii string containing the version of the software. 1605 1606 CONFIG_CDP_PLATFORM 1607 1608 An ascii string containing the name of the platform. 1609 1610 CONFIG_CDP_TRIGGER 1611 1612 A 32bit integer sent on the trigger. 1613 1614 CONFIG_CDP_POWER_CONSUMPTION 1615 1616 A 16bit integer containing the power consumption of the 1617 device in .1 of milliwatts. 1618 1619 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1620 1621 A byte containing the id of the VLAN. 1622 1623- Status LED: CONFIG_LED_STATUS 1624 1625 Several configurations allow to display the current 1626 status using a LED. For instance, the LED will blink 1627 fast while running U-Boot code, stop blinking as 1628 soon as a reply to a BOOTP request was received, and 1629 start blinking slow once the Linux kernel is running 1630 (supported by a status LED driver in the Linux 1631 kernel). Defining CONFIG_LED_STATUS enables this 1632 feature in U-Boot. 1633 1634 Additional options: 1635 1636 CONFIG_LED_STATUS_GPIO 1637 The status LED can be connected to a GPIO pin. 1638 In such cases, the gpio_led driver can be used as a 1639 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1640 to include the gpio_led driver in the U-Boot binary. 1641 1642 CONFIG_GPIO_LED_INVERTED_TABLE 1643 Some GPIO connected LEDs may have inverted polarity in which 1644 case the GPIO high value corresponds to LED off state and 1645 GPIO low value corresponds to LED on state. 1646 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1647 with a list of GPIO LEDs that have inverted polarity. 1648 1649- I2C Support: CONFIG_SYS_I2C 1650 1651 This enable the NEW i2c subsystem, and will allow you to use 1652 i2c commands at the u-boot command line (as long as you set 1653 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1654 based realtime clock chips or other i2c devices. See 1655 common/cmd_i2c.c for a description of the command line 1656 interface. 1657 1658 ported i2c driver to the new framework: 1659 - drivers/i2c/soft_i2c.c: 1660 - activate first bus with CONFIG_SYS_I2C_SOFT define 1661 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1662 for defining speed and slave address 1663 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1664 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1665 for defining speed and slave address 1666 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1667 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1668 for defining speed and slave address 1669 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1670 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1671 for defining speed and slave address 1672 1673 - drivers/i2c/fsl_i2c.c: 1674 - activate i2c driver with CONFIG_SYS_I2C_FSL 1675 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1676 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1677 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1678 bus. 1679 - If your board supports a second fsl i2c bus, define 1680 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1681 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1682 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1683 second bus. 1684 1685 - drivers/i2c/tegra_i2c.c: 1686 - activate this driver with CONFIG_SYS_I2C_TEGRA 1687 - This driver adds 4 i2c buses with a fix speed from 1688 100000 and the slave addr 0! 1689 1690 - drivers/i2c/ppc4xx_i2c.c 1691 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1692 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1693 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1694 1695 - drivers/i2c/i2c_mxc.c 1696 - activate this driver with CONFIG_SYS_I2C_MXC 1697 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1698 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1699 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1700 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1701 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1702 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1703 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1704 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1705 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1706 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1707 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1708 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1709 If those defines are not set, default value is 100000 1710 for speed, and 0 for slave. 1711 1712 - drivers/i2c/rcar_i2c.c: 1713 - activate this driver with CONFIG_SYS_I2C_RCAR 1714 - This driver adds 4 i2c buses 1715 1716 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1717 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1718 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1719 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1720 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1721 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1722 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1723 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1724 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1725 1726 - drivers/i2c/sh_i2c.c: 1727 - activate this driver with CONFIG_SYS_I2C_SH 1728 - This driver adds from 2 to 5 i2c buses 1729 1730 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1731 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1732 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1733 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1734 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1735 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1736 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1737 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1738 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1739 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1740 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1741 1742 - drivers/i2c/omap24xx_i2c.c 1743 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1744 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1745 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1746 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1747 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1748 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1749 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1750 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1751 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1752 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1753 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1754 1755 - drivers/i2c/zynq_i2c.c 1756 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1757 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1758 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1759 1760 - drivers/i2c/s3c24x0_i2c.c: 1761 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1762 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1763 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1764 with a fix speed from 100000 and the slave addr 0! 1765 1766 - drivers/i2c/ihs_i2c.c 1767 - activate this driver with CONFIG_SYS_I2C_IHS 1768 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1769 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1770 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1771 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1772 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1773 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1774 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1775 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1776 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1777 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1778 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1779 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1780 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1781 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1782 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1783 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1784 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1785 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1786 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1787 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1788 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1789 1790 additional defines: 1791 1792 CONFIG_SYS_NUM_I2C_BUSES 1793 Hold the number of i2c buses you want to use. 1794 1795 CONFIG_SYS_I2C_DIRECT_BUS 1796 define this, if you don't use i2c muxes on your hardware. 1797 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1798 omit this define. 1799 1800 CONFIG_SYS_I2C_MAX_HOPS 1801 define how many muxes are maximal consecutively connected 1802 on one i2c bus. If you not use i2c muxes, omit this 1803 define. 1804 1805 CONFIG_SYS_I2C_BUSES 1806 hold a list of buses you want to use, only used if 1807 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1808 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1809 CONFIG_SYS_NUM_I2C_BUSES = 9: 1810 1811 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1812 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1813 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1814 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1815 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1816 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1817 {1, {I2C_NULL_HOP}}, \ 1818 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1819 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1820 } 1821 1822 which defines 1823 bus 0 on adapter 0 without a mux 1824 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1825 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1826 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1827 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1828 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1829 bus 6 on adapter 1 without a mux 1830 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1831 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1832 1833 If you do not have i2c muxes on your board, omit this define. 1834 1835- Legacy I2C Support: 1836 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1837 then the following macros need to be defined (examples are 1838 from include/configs/lwmon.h): 1839 1840 I2C_INIT 1841 1842 (Optional). Any commands necessary to enable the I2C 1843 controller or configure ports. 1844 1845 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1846 1847 I2C_ACTIVE 1848 1849 The code necessary to make the I2C data line active 1850 (driven). If the data line is open collector, this 1851 define can be null. 1852 1853 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1854 1855 I2C_TRISTATE 1856 1857 The code necessary to make the I2C data line tri-stated 1858 (inactive). If the data line is open collector, this 1859 define can be null. 1860 1861 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1862 1863 I2C_READ 1864 1865 Code that returns true if the I2C data line is high, 1866 false if it is low. 1867 1868 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1869 1870 I2C_SDA(bit) 1871 1872 If <bit> is true, sets the I2C data line high. If it 1873 is false, it clears it (low). 1874 1875 eg: #define I2C_SDA(bit) \ 1876 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1877 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1878 1879 I2C_SCL(bit) 1880 1881 If <bit> is true, sets the I2C clock line high. If it 1882 is false, it clears it (low). 1883 1884 eg: #define I2C_SCL(bit) \ 1885 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1886 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1887 1888 I2C_DELAY 1889 1890 This delay is invoked four times per clock cycle so this 1891 controls the rate of data transfer. The data rate thus 1892 is 1 / (I2C_DELAY * 4). Often defined to be something 1893 like: 1894 1895 #define I2C_DELAY udelay(2) 1896 1897 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1898 1899 If your arch supports the generic GPIO framework (asm/gpio.h), 1900 then you may alternatively define the two GPIOs that are to be 1901 used as SCL / SDA. Any of the previous I2C_xxx macros will 1902 have GPIO-based defaults assigned to them as appropriate. 1903 1904 You should define these to the GPIO value as given directly to 1905 the generic GPIO functions. 1906 1907 CONFIG_SYS_I2C_INIT_BOARD 1908 1909 When a board is reset during an i2c bus transfer 1910 chips might think that the current transfer is still 1911 in progress. On some boards it is possible to access 1912 the i2c SCLK line directly, either by using the 1913 processor pin as a GPIO or by having a second pin 1914 connected to the bus. If this option is defined a 1915 custom i2c_init_board() routine in boards/xxx/board.c 1916 is run early in the boot sequence. 1917 1918 CONFIG_I2C_MULTI_BUS 1919 1920 This option allows the use of multiple I2C buses, each of which 1921 must have a controller. At any point in time, only one bus is 1922 active. To switch to a different bus, use the 'i2c dev' command. 1923 Note that bus numbering is zero-based. 1924 1925 CONFIG_SYS_I2C_NOPROBES 1926 1927 This option specifies a list of I2C devices that will be skipped 1928 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1929 is set, specify a list of bus-device pairs. Otherwise, specify 1930 a 1D array of device addresses 1931 1932 e.g. 1933 #undef CONFIG_I2C_MULTI_BUS 1934 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1935 1936 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1937 1938 #define CONFIG_I2C_MULTI_BUS 1939 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1940 1941 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1942 1943 CONFIG_SYS_SPD_BUS_NUM 1944 1945 If defined, then this indicates the I2C bus number for DDR SPD. 1946 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1947 1948 CONFIG_SYS_RTC_BUS_NUM 1949 1950 If defined, then this indicates the I2C bus number for the RTC. 1951 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1952 1953 CONFIG_SOFT_I2C_READ_REPEATED_START 1954 1955 defining this will force the i2c_read() function in 1956 the soft_i2c driver to perform an I2C repeated start 1957 between writing the address pointer and reading the 1958 data. If this define is omitted the default behaviour 1959 of doing a stop-start sequence will be used. Most I2C 1960 devices can use either method, but some require one or 1961 the other. 1962 1963- SPI Support: CONFIG_SPI 1964 1965 Enables SPI driver (so far only tested with 1966 SPI EEPROM, also an instance works with Crystal A/D and 1967 D/As on the SACSng board) 1968 1969 CONFIG_SOFT_SPI 1970 1971 Enables a software (bit-bang) SPI driver rather than 1972 using hardware support. This is a general purpose 1973 driver that only requires three general I/O port pins 1974 (two outputs, one input) to function. If this is 1975 defined, the board configuration must define several 1976 SPI configuration items (port pins to use, etc). For 1977 an example, see include/configs/sacsng.h. 1978 1979 CONFIG_HARD_SPI 1980 1981 Enables a hardware SPI driver for general-purpose reads 1982 and writes. As with CONFIG_SOFT_SPI, the board configuration 1983 must define a list of chip-select function pointers. 1984 Currently supported on some MPC8xxx processors. For an 1985 example, see include/configs/mpc8349emds.h. 1986 1987 CONFIG_SYS_SPI_MXC_WAIT 1988 Timeout for waiting until spi transfer completed. 1989 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1990 1991- FPGA Support: CONFIG_FPGA 1992 1993 Enables FPGA subsystem. 1994 1995 CONFIG_FPGA_<vendor> 1996 1997 Enables support for specific chip vendors. 1998 (ALTERA, XILINX) 1999 2000 CONFIG_FPGA_<family> 2001 2002 Enables support for FPGA family. 2003 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2004 2005 CONFIG_FPGA_COUNT 2006 2007 Specify the number of FPGA devices to support. 2008 2009 CONFIG_SYS_FPGA_PROG_FEEDBACK 2010 2011 Enable printing of hash marks during FPGA configuration. 2012 2013 CONFIG_SYS_FPGA_CHECK_BUSY 2014 2015 Enable checks on FPGA configuration interface busy 2016 status by the configuration function. This option 2017 will require a board or device specific function to 2018 be written. 2019 2020 CONFIG_FPGA_DELAY 2021 2022 If defined, a function that provides delays in the FPGA 2023 configuration driver. 2024 2025 CONFIG_SYS_FPGA_CHECK_CTRLC 2026 Allow Control-C to interrupt FPGA configuration 2027 2028 CONFIG_SYS_FPGA_CHECK_ERROR 2029 2030 Check for configuration errors during FPGA bitfile 2031 loading. For example, abort during Virtex II 2032 configuration if the INIT_B line goes low (which 2033 indicated a CRC error). 2034 2035 CONFIG_SYS_FPGA_WAIT_INIT 2036 2037 Maximum time to wait for the INIT_B line to de-assert 2038 after PROB_B has been de-asserted during a Virtex II 2039 FPGA configuration sequence. The default time is 500 2040 ms. 2041 2042 CONFIG_SYS_FPGA_WAIT_BUSY 2043 2044 Maximum time to wait for BUSY to de-assert during 2045 Virtex II FPGA configuration. The default is 5 ms. 2046 2047 CONFIG_SYS_FPGA_WAIT_CONFIG 2048 2049 Time to wait after FPGA configuration. The default is 2050 200 ms. 2051 2052- Configuration Management: 2053 CONFIG_BUILD_TARGET 2054 2055 Some SoCs need special image types (e.g. U-Boot binary 2056 with a special header) as build targets. By defining 2057 CONFIG_BUILD_TARGET in the SoC / board header, this 2058 special image will be automatically built upon calling 2059 make / buildman. 2060 2061 CONFIG_IDENT_STRING 2062 2063 If defined, this string will be added to the U-Boot 2064 version information (U_BOOT_VERSION) 2065 2066- Vendor Parameter Protection: 2067 2068 U-Boot considers the values of the environment 2069 variables "serial#" (Board Serial Number) and 2070 "ethaddr" (Ethernet Address) to be parameters that 2071 are set once by the board vendor / manufacturer, and 2072 protects these variables from casual modification by 2073 the user. Once set, these variables are read-only, 2074 and write or delete attempts are rejected. You can 2075 change this behaviour: 2076 2077 If CONFIG_ENV_OVERWRITE is #defined in your config 2078 file, the write protection for vendor parameters is 2079 completely disabled. Anybody can change or delete 2080 these parameters. 2081 2082 Alternatively, if you define _both_ an ethaddr in the 2083 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2084 Ethernet address is installed in the environment, 2085 which can be changed exactly ONCE by the user. [The 2086 serial# is unaffected by this, i. e. it remains 2087 read-only.] 2088 2089 The same can be accomplished in a more flexible way 2090 for any variable by configuring the type of access 2091 to allow for those variables in the ".flags" variable 2092 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2093 2094- Protected RAM: 2095 CONFIG_PRAM 2096 2097 Define this variable to enable the reservation of 2098 "protected RAM", i. e. RAM which is not overwritten 2099 by U-Boot. Define CONFIG_PRAM to hold the number of 2100 kB you want to reserve for pRAM. You can overwrite 2101 this default value by defining an environment 2102 variable "pram" to the number of kB you want to 2103 reserve. Note that the board info structure will 2104 still show the full amount of RAM. If pRAM is 2105 reserved, a new environment variable "mem" will 2106 automatically be defined to hold the amount of 2107 remaining RAM in a form that can be passed as boot 2108 argument to Linux, for instance like that: 2109 2110 setenv bootargs ... mem=\${mem} 2111 saveenv 2112 2113 This way you can tell Linux not to use this memory, 2114 either, which results in a memory region that will 2115 not be affected by reboots. 2116 2117 *WARNING* If your board configuration uses automatic 2118 detection of the RAM size, you must make sure that 2119 this memory test is non-destructive. So far, the 2120 following board configurations are known to be 2121 "pRAM-clean": 2122 2123 IVMS8, IVML24, SPD8xx, 2124 HERMES, IP860, RPXlite, LWMON, 2125 FLAGADM 2126 2127- Access to physical memory region (> 4GB) 2128 Some basic support is provided for operations on memory not 2129 normally accessible to U-Boot - e.g. some architectures 2130 support access to more than 4GB of memory on 32-bit 2131 machines using physical address extension or similar. 2132 Define CONFIG_PHYSMEM to access this basic support, which 2133 currently only supports clearing the memory. 2134 2135- Error Recovery: 2136 CONFIG_NET_RETRY_COUNT 2137 2138 This variable defines the number of retries for 2139 network operations like ARP, RARP, TFTP, or BOOTP 2140 before giving up the operation. If not defined, a 2141 default value of 5 is used. 2142 2143 CONFIG_ARP_TIMEOUT 2144 2145 Timeout waiting for an ARP reply in milliseconds. 2146 2147 CONFIG_NFS_TIMEOUT 2148 2149 Timeout in milliseconds used in NFS protocol. 2150 If you encounter "ERROR: Cannot umount" in nfs command, 2151 try longer timeout such as 2152 #define CONFIG_NFS_TIMEOUT 10000UL 2153 2154- Command Interpreter: 2155 CONFIG_SYS_PROMPT_HUSH_PS2 2156 2157 This defines the secondary prompt string, which is 2158 printed when the command interpreter needs more input 2159 to complete a command. Usually "> ". 2160 2161 Note: 2162 2163 In the current implementation, the local variables 2164 space and global environment variables space are 2165 separated. Local variables are those you define by 2166 simply typing `name=value'. To access a local 2167 variable later on, you have write `$name' or 2168 `${name}'; to execute the contents of a variable 2169 directly type `$name' at the command prompt. 2170 2171 Global environment variables are those you use 2172 setenv/printenv to work with. To run a command stored 2173 in such a variable, you need to use the run command, 2174 and you must not use the '$' sign to access them. 2175 2176 To store commands and special characters in a 2177 variable, please use double quotation marks 2178 surrounding the whole text of the variable, instead 2179 of the backslashes before semicolons and special 2180 symbols. 2181 2182- Command Line Editing and History: 2183 CONFIG_CMDLINE_PS_SUPPORT 2184 2185 Enable support for changing the command prompt string 2186 at run-time. Only static string is supported so far. 2187 The string is obtained from environment variables PS1 2188 and PS2. 2189 2190- Default Environment: 2191 CONFIG_EXTRA_ENV_SETTINGS 2192 2193 Define this to contain any number of null terminated 2194 strings (variable = value pairs) that will be part of 2195 the default environment compiled into the boot image. 2196 2197 For example, place something like this in your 2198 board's config file: 2199 2200 #define CONFIG_EXTRA_ENV_SETTINGS \ 2201 "myvar1=value1\0" \ 2202 "myvar2=value2\0" 2203 2204 Warning: This method is based on knowledge about the 2205 internal format how the environment is stored by the 2206 U-Boot code. This is NOT an official, exported 2207 interface! Although it is unlikely that this format 2208 will change soon, there is no guarantee either. 2209 You better know what you are doing here. 2210 2211 Note: overly (ab)use of the default environment is 2212 discouraged. Make sure to check other ways to preset 2213 the environment like the "source" command or the 2214 boot command first. 2215 2216 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2217 2218 Define this in order to add variables describing certain 2219 run-time determined information about the hardware to the 2220 environment. These will be named board_name, board_rev. 2221 2222 CONFIG_DELAY_ENVIRONMENT 2223 2224 Normally the environment is loaded when the board is 2225 initialised so that it is available to U-Boot. This inhibits 2226 that so that the environment is not available until 2227 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2228 this is instead controlled by the value of 2229 /config/load-environment. 2230 2231- Serial Flash support 2232 Usage requires an initial 'sf probe' to define the serial 2233 flash parameters, followed by read/write/erase/update 2234 commands. 2235 2236 The following defaults may be provided by the platform 2237 to handle the common case when only a single serial 2238 flash is present on the system. 2239 2240 CONFIG_SF_DEFAULT_BUS Bus identifier 2241 CONFIG_SF_DEFAULT_CS Chip-select 2242 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2243 CONFIG_SF_DEFAULT_SPEED in Hz 2244 2245 2246- TFTP Fixed UDP Port: 2247 CONFIG_TFTP_PORT 2248 2249 If this is defined, the environment variable tftpsrcp 2250 is used to supply the TFTP UDP source port value. 2251 If tftpsrcp isn't defined, the normal pseudo-random port 2252 number generator is used. 2253 2254 Also, the environment variable tftpdstp is used to supply 2255 the TFTP UDP destination port value. If tftpdstp isn't 2256 defined, the normal port 69 is used. 2257 2258 The purpose for tftpsrcp is to allow a TFTP server to 2259 blindly start the TFTP transfer using the pre-configured 2260 target IP address and UDP port. This has the effect of 2261 "punching through" the (Windows XP) firewall, allowing 2262 the remainder of the TFTP transfer to proceed normally. 2263 A better solution is to properly configure the firewall, 2264 but sometimes that is not allowed. 2265 2266- Show boot progress: 2267 CONFIG_SHOW_BOOT_PROGRESS 2268 2269 Defining this option allows to add some board- 2270 specific code (calling a user-provided function 2271 "show_boot_progress(int)") that enables you to show 2272 the system's boot progress on some display (for 2273 example, some LED's) on your board. At the moment, 2274 the following checkpoints are implemented: 2275 2276 2277Legacy uImage format: 2278 2279 Arg Where When 2280 1 common/cmd_bootm.c before attempting to boot an image 2281 -1 common/cmd_bootm.c Image header has bad magic number 2282 2 common/cmd_bootm.c Image header has correct magic number 2283 -2 common/cmd_bootm.c Image header has bad checksum 2284 3 common/cmd_bootm.c Image header has correct checksum 2285 -3 common/cmd_bootm.c Image data has bad checksum 2286 4 common/cmd_bootm.c Image data has correct checksum 2287 -4 common/cmd_bootm.c Image is for unsupported architecture 2288 5 common/cmd_bootm.c Architecture check OK 2289 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2290 6 common/cmd_bootm.c Image Type check OK 2291 -6 common/cmd_bootm.c gunzip uncompression error 2292 -7 common/cmd_bootm.c Unimplemented compression type 2293 7 common/cmd_bootm.c Uncompression OK 2294 8 common/cmd_bootm.c No uncompress/copy overwrite error 2295 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2296 2297 9 common/image.c Start initial ramdisk verification 2298 -10 common/image.c Ramdisk header has bad magic number 2299 -11 common/image.c Ramdisk header has bad checksum 2300 10 common/image.c Ramdisk header is OK 2301 -12 common/image.c Ramdisk data has bad checksum 2302 11 common/image.c Ramdisk data has correct checksum 2303 12 common/image.c Ramdisk verification complete, start loading 2304 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2305 13 common/image.c Start multifile image verification 2306 14 common/image.c No initial ramdisk, no multifile, continue. 2307 2308 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2309 2310 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2311 -31 post/post.c POST test failed, detected by post_output_backlog() 2312 -32 post/post.c POST test failed, detected by post_run_single() 2313 2314 34 common/cmd_doc.c before loading a Image from a DOC device 2315 -35 common/cmd_doc.c Bad usage of "doc" command 2316 35 common/cmd_doc.c correct usage of "doc" command 2317 -36 common/cmd_doc.c No boot device 2318 36 common/cmd_doc.c correct boot device 2319 -37 common/cmd_doc.c Unknown Chip ID on boot device 2320 37 common/cmd_doc.c correct chip ID found, device available 2321 -38 common/cmd_doc.c Read Error on boot device 2322 38 common/cmd_doc.c reading Image header from DOC device OK 2323 -39 common/cmd_doc.c Image header has bad magic number 2324 39 common/cmd_doc.c Image header has correct magic number 2325 -40 common/cmd_doc.c Error reading Image from DOC device 2326 40 common/cmd_doc.c Image header has correct magic number 2327 41 common/cmd_ide.c before loading a Image from a IDE device 2328 -42 common/cmd_ide.c Bad usage of "ide" command 2329 42 common/cmd_ide.c correct usage of "ide" command 2330 -43 common/cmd_ide.c No boot device 2331 43 common/cmd_ide.c boot device found 2332 -44 common/cmd_ide.c Device not available 2333 44 common/cmd_ide.c Device available 2334 -45 common/cmd_ide.c wrong partition selected 2335 45 common/cmd_ide.c partition selected 2336 -46 common/cmd_ide.c Unknown partition table 2337 46 common/cmd_ide.c valid partition table found 2338 -47 common/cmd_ide.c Invalid partition type 2339 47 common/cmd_ide.c correct partition type 2340 -48 common/cmd_ide.c Error reading Image Header on boot device 2341 48 common/cmd_ide.c reading Image Header from IDE device OK 2342 -49 common/cmd_ide.c Image header has bad magic number 2343 49 common/cmd_ide.c Image header has correct magic number 2344 -50 common/cmd_ide.c Image header has bad checksum 2345 50 common/cmd_ide.c Image header has correct checksum 2346 -51 common/cmd_ide.c Error reading Image from IDE device 2347 51 common/cmd_ide.c reading Image from IDE device OK 2348 52 common/cmd_nand.c before loading a Image from a NAND device 2349 -53 common/cmd_nand.c Bad usage of "nand" command 2350 53 common/cmd_nand.c correct usage of "nand" command 2351 -54 common/cmd_nand.c No boot device 2352 54 common/cmd_nand.c boot device found 2353 -55 common/cmd_nand.c Unknown Chip ID on boot device 2354 55 common/cmd_nand.c correct chip ID found, device available 2355 -56 common/cmd_nand.c Error reading Image Header on boot device 2356 56 common/cmd_nand.c reading Image Header from NAND device OK 2357 -57 common/cmd_nand.c Image header has bad magic number 2358 57 common/cmd_nand.c Image header has correct magic number 2359 -58 common/cmd_nand.c Error reading Image from NAND device 2360 58 common/cmd_nand.c reading Image from NAND device OK 2361 2362 -60 common/env_common.c Environment has a bad CRC, using default 2363 2364 64 net/eth.c starting with Ethernet configuration. 2365 -64 net/eth.c no Ethernet found. 2366 65 net/eth.c Ethernet found. 2367 2368 -80 common/cmd_net.c usage wrong 2369 80 common/cmd_net.c before calling net_loop() 2370 -81 common/cmd_net.c some error in net_loop() occurred 2371 81 common/cmd_net.c net_loop() back without error 2372 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2373 82 common/cmd_net.c trying automatic boot 2374 83 common/cmd_net.c running "source" command 2375 -83 common/cmd_net.c some error in automatic boot or "source" command 2376 84 common/cmd_net.c end without errors 2377 2378FIT uImage format: 2379 2380 Arg Where When 2381 100 common/cmd_bootm.c Kernel FIT Image has correct format 2382 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2383 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2384 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2385 102 common/cmd_bootm.c Kernel unit name specified 2386 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2387 103 common/cmd_bootm.c Found configuration node 2388 104 common/cmd_bootm.c Got kernel subimage node offset 2389 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2390 105 common/cmd_bootm.c Kernel subimage hash verification OK 2391 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2392 106 common/cmd_bootm.c Architecture check OK 2393 -106 common/cmd_bootm.c Kernel subimage has wrong type 2394 107 common/cmd_bootm.c Kernel subimage type OK 2395 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2396 108 common/cmd_bootm.c Got kernel subimage data/size 2397 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2398 -109 common/cmd_bootm.c Can't get kernel subimage type 2399 -110 common/cmd_bootm.c Can't get kernel subimage comp 2400 -111 common/cmd_bootm.c Can't get kernel subimage os 2401 -112 common/cmd_bootm.c Can't get kernel subimage load address 2402 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2403 2404 120 common/image.c Start initial ramdisk verification 2405 -120 common/image.c Ramdisk FIT image has incorrect format 2406 121 common/image.c Ramdisk FIT image has correct format 2407 122 common/image.c No ramdisk subimage unit name, using configuration 2408 -122 common/image.c Can't get configuration for ramdisk subimage 2409 123 common/image.c Ramdisk unit name specified 2410 -124 common/image.c Can't get ramdisk subimage node offset 2411 125 common/image.c Got ramdisk subimage node offset 2412 -125 common/image.c Ramdisk subimage hash verification failed 2413 126 common/image.c Ramdisk subimage hash verification OK 2414 -126 common/image.c Ramdisk subimage for unsupported architecture 2415 127 common/image.c Architecture check OK 2416 -127 common/image.c Can't get ramdisk subimage data/size 2417 128 common/image.c Got ramdisk subimage data/size 2418 129 common/image.c Can't get ramdisk load address 2419 -129 common/image.c Got ramdisk load address 2420 2421 -130 common/cmd_doc.c Incorrect FIT image format 2422 131 common/cmd_doc.c FIT image format OK 2423 2424 -140 common/cmd_ide.c Incorrect FIT image format 2425 141 common/cmd_ide.c FIT image format OK 2426 2427 -150 common/cmd_nand.c Incorrect FIT image format 2428 151 common/cmd_nand.c FIT image format OK 2429 2430- legacy image format: 2431 CONFIG_IMAGE_FORMAT_LEGACY 2432 enables the legacy image format support in U-Boot. 2433 2434 Default: 2435 enabled if CONFIG_FIT_SIGNATURE is not defined. 2436 2437 CONFIG_DISABLE_IMAGE_LEGACY 2438 disable the legacy image format 2439 2440 This define is introduced, as the legacy image format is 2441 enabled per default for backward compatibility. 2442 2443- Standalone program support: 2444 CONFIG_STANDALONE_LOAD_ADDR 2445 2446 This option defines a board specific value for the 2447 address where standalone program gets loaded, thus 2448 overwriting the architecture dependent default 2449 settings. 2450 2451- Frame Buffer Address: 2452 CONFIG_FB_ADDR 2453 2454 Define CONFIG_FB_ADDR if you want to use specific 2455 address for frame buffer. This is typically the case 2456 when using a graphics controller has separate video 2457 memory. U-Boot will then place the frame buffer at 2458 the given address instead of dynamically reserving it 2459 in system RAM by calling lcd_setmem(), which grabs 2460 the memory for the frame buffer depending on the 2461 configured panel size. 2462 2463 Please see board_init_f function. 2464 2465- Automatic software updates via TFTP server 2466 CONFIG_UPDATE_TFTP 2467 CONFIG_UPDATE_TFTP_CNT_MAX 2468 CONFIG_UPDATE_TFTP_MSEC_MAX 2469 2470 These options enable and control the auto-update feature; 2471 for a more detailed description refer to doc/README.update. 2472 2473- MTD Support (mtdparts command, UBI support) 2474 CONFIG_MTD_DEVICE 2475 2476 Adds the MTD device infrastructure from the Linux kernel. 2477 Needed for mtdparts command support. 2478 2479 CONFIG_MTD_PARTITIONS 2480 2481 Adds the MTD partitioning infrastructure from the Linux 2482 kernel. Needed for UBI support. 2483 2484- UBI support 2485 CONFIG_UBI_SILENCE_MSG 2486 2487 Make the verbose messages from UBI stop printing. This leaves 2488 warnings and errors enabled. 2489 2490 2491 CONFIG_MTD_UBI_WL_THRESHOLD 2492 This parameter defines the maximum difference between the highest 2493 erase counter value and the lowest erase counter value of eraseblocks 2494 of UBI devices. When this threshold is exceeded, UBI starts performing 2495 wear leveling by means of moving data from eraseblock with low erase 2496 counter to eraseblocks with high erase counter. 2497 2498 The default value should be OK for SLC NAND flashes, NOR flashes and 2499 other flashes which have eraseblock life-cycle 100000 or more. 2500 However, in case of MLC NAND flashes which typically have eraseblock 2501 life-cycle less than 10000, the threshold should be lessened (e.g., 2502 to 128 or 256, although it does not have to be power of 2). 2503 2504 default: 4096 2505 2506 CONFIG_MTD_UBI_BEB_LIMIT 2507 This option specifies the maximum bad physical eraseblocks UBI 2508 expects on the MTD device (per 1024 eraseblocks). If the 2509 underlying flash does not admit of bad eraseblocks (e.g. NOR 2510 flash), this value is ignored. 2511 2512 NAND datasheets often specify the minimum and maximum NVM 2513 (Number of Valid Blocks) for the flashes' endurance lifetime. 2514 The maximum expected bad eraseblocks per 1024 eraseblocks 2515 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2516 which gives 20 for most NANDs (MaxNVB is basically the total 2517 count of eraseblocks on the chip). 2518 2519 To put it differently, if this value is 20, UBI will try to 2520 reserve about 1.9% of physical eraseblocks for bad blocks 2521 handling. And that will be 1.9% of eraseblocks on the entire 2522 NAND chip, not just the MTD partition UBI attaches. This means 2523 that if you have, say, a NAND flash chip admits maximum 40 bad 2524 eraseblocks, and it is split on two MTD partitions of the same 2525 size, UBI will reserve 40 eraseblocks when attaching a 2526 partition. 2527 2528 default: 20 2529 2530 CONFIG_MTD_UBI_FASTMAP 2531 Fastmap is a mechanism which allows attaching an UBI device 2532 in nearly constant time. Instead of scanning the whole MTD device it 2533 only has to locate a checkpoint (called fastmap) on the device. 2534 The on-flash fastmap contains all information needed to attach 2535 the device. Using fastmap makes only sense on large devices where 2536 attaching by scanning takes long. UBI will not automatically install 2537 a fastmap on old images, but you can set the UBI parameter 2538 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2539 that fastmap-enabled images are still usable with UBI implementations 2540 without fastmap support. On typical flash devices the whole fastmap 2541 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2542 2543 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2544 Set this parameter to enable fastmap automatically on images 2545 without a fastmap. 2546 default: 0 2547 2548 CONFIG_MTD_UBI_FM_DEBUG 2549 Enable UBI fastmap debug 2550 default: 0 2551 2552- UBIFS support 2553 CONFIG_UBIFS_SILENCE_MSG 2554 2555 Make the verbose messages from UBIFS stop printing. This leaves 2556 warnings and errors enabled. 2557 2558- SPL framework 2559 CONFIG_SPL 2560 Enable building of SPL globally. 2561 2562 CONFIG_SPL_LDSCRIPT 2563 LDSCRIPT for linking the SPL binary. 2564 2565 CONFIG_SPL_MAX_FOOTPRINT 2566 Maximum size in memory allocated to the SPL, BSS included. 2567 When defined, the linker checks that the actual memory 2568 used by SPL from _start to __bss_end does not exceed it. 2569 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2570 must not be both defined at the same time. 2571 2572 CONFIG_SPL_MAX_SIZE 2573 Maximum size of the SPL image (text, data, rodata, and 2574 linker lists sections), BSS excluded. 2575 When defined, the linker checks that the actual size does 2576 not exceed it. 2577 2578 CONFIG_SPL_TEXT_BASE 2579 TEXT_BASE for linking the SPL binary. 2580 2581 CONFIG_SPL_RELOC_TEXT_BASE 2582 Address to relocate to. If unspecified, this is equal to 2583 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2584 2585 CONFIG_SPL_BSS_START_ADDR 2586 Link address for the BSS within the SPL binary. 2587 2588 CONFIG_SPL_BSS_MAX_SIZE 2589 Maximum size in memory allocated to the SPL BSS. 2590 When defined, the linker checks that the actual memory used 2591 by SPL from __bss_start to __bss_end does not exceed it. 2592 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2593 must not be both defined at the same time. 2594 2595 CONFIG_SPL_STACK 2596 Adress of the start of the stack SPL will use 2597 2598 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2599 When defined, SPL will panic() if the image it has 2600 loaded does not have a signature. 2601 Defining this is useful when code which loads images 2602 in SPL cannot guarantee that absolutely all read errors 2603 will be caught. 2604 An example is the LPC32XX MLC NAND driver, which will 2605 consider that a completely unreadable NAND block is bad, 2606 and thus should be skipped silently. 2607 2608 CONFIG_SPL_RELOC_STACK 2609 Adress of the start of the stack SPL will use after 2610 relocation. If unspecified, this is equal to 2611 CONFIG_SPL_STACK. 2612 2613 CONFIG_SYS_SPL_MALLOC_START 2614 Starting address of the malloc pool used in SPL. 2615 When this option is set the full malloc is used in SPL and 2616 it is set up by spl_init() and before that, the simple malloc() 2617 can be used if CONFIG_SYS_MALLOC_F is defined. 2618 2619 CONFIG_SYS_SPL_MALLOC_SIZE 2620 The size of the malloc pool used in SPL. 2621 2622 CONFIG_SPL_OS_BOOT 2623 Enable booting directly to an OS from SPL. 2624 See also: doc/README.falcon 2625 2626 CONFIG_SPL_DISPLAY_PRINT 2627 For ARM, enable an optional function to print more information 2628 about the running system. 2629 2630 CONFIG_SPL_INIT_MINIMAL 2631 Arch init code should be built for a very small image 2632 2633 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2634 Partition on the MMC to load U-Boot from when the MMC is being 2635 used in raw mode 2636 2637 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2638 Sector to load kernel uImage from when MMC is being 2639 used in raw mode (for Falcon mode) 2640 2641 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2642 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2643 Sector and number of sectors to load kernel argument 2644 parameters from when MMC is being used in raw mode 2645 (for falcon mode) 2646 2647 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2648 Partition on the MMC to load U-Boot from when the MMC is being 2649 used in fs mode 2650 2651 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2652 Filename to read to load U-Boot when reading from filesystem 2653 2654 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2655 Filename to read to load kernel uImage when reading 2656 from filesystem (for Falcon mode) 2657 2658 CONFIG_SPL_FS_LOAD_ARGS_NAME 2659 Filename to read to load kernel argument parameters 2660 when reading from filesystem (for Falcon mode) 2661 2662 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2663 Set this for NAND SPL on PPC mpc83xx targets, so that 2664 start.S waits for the rest of the SPL to load before 2665 continuing (the hardware starts execution after just 2666 loading the first page rather than the full 4K). 2667 2668 CONFIG_SPL_SKIP_RELOCATE 2669 Avoid SPL relocation 2670 2671 CONFIG_SPL_NAND_BASE 2672 Include nand_base.c in the SPL. Requires 2673 CONFIG_SPL_NAND_DRIVERS. 2674 2675 CONFIG_SPL_NAND_DRIVERS 2676 SPL uses normal NAND drivers, not minimal drivers. 2677 2678 CONFIG_SPL_NAND_ECC 2679 Include standard software ECC in the SPL 2680 2681 CONFIG_SPL_NAND_SIMPLE 2682 Support for NAND boot using simple NAND drivers that 2683 expose the cmd_ctrl() interface. 2684 2685 CONFIG_SPL_UBI 2686 Support for a lightweight UBI (fastmap) scanner and 2687 loader 2688 2689 CONFIG_SPL_NAND_RAW_ONLY 2690 Support to boot only raw u-boot.bin images. Use this only 2691 if you need to save space. 2692 2693 CONFIG_SPL_COMMON_INIT_DDR 2694 Set for common ddr init with serial presence detect in 2695 SPL binary. 2696 2697 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2698 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2699 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2700 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2701 CONFIG_SYS_NAND_ECCBYTES 2702 Defines the size and behavior of the NAND that SPL uses 2703 to read U-Boot 2704 2705 CONFIG_SPL_NAND_BOOT 2706 Add support NAND boot 2707 2708 CONFIG_SYS_NAND_U_BOOT_OFFS 2709 Location in NAND to read U-Boot from 2710 2711 CONFIG_SYS_NAND_U_BOOT_DST 2712 Location in memory to load U-Boot to 2713 2714 CONFIG_SYS_NAND_U_BOOT_SIZE 2715 Size of image to load 2716 2717 CONFIG_SYS_NAND_U_BOOT_START 2718 Entry point in loaded image to jump to 2719 2720 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2721 Define this if you need to first read the OOB and then the 2722 data. This is used, for example, on davinci platforms. 2723 2724 CONFIG_SPL_RAM_DEVICE 2725 Support for running image already present in ram, in SPL binary 2726 2727 CONFIG_SPL_PAD_TO 2728 Image offset to which the SPL should be padded before appending 2729 the SPL payload. By default, this is defined as 2730 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2731 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2732 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2733 2734 CONFIG_SPL_TARGET 2735 Final target image containing SPL and payload. Some SPLs 2736 use an arch-specific makefile fragment instead, for 2737 example if more than one image needs to be produced. 2738 2739 CONFIG_FIT_SPL_PRINT 2740 Printing information about a FIT image adds quite a bit of 2741 code to SPL. So this is normally disabled in SPL. Use this 2742 option to re-enable it. This will affect the output of the 2743 bootm command when booting a FIT image. 2744 2745- TPL framework 2746 CONFIG_TPL 2747 Enable building of TPL globally. 2748 2749 CONFIG_TPL_PAD_TO 2750 Image offset to which the TPL should be padded before appending 2751 the TPL payload. By default, this is defined as 2752 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2753 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2754 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2755 2756- Interrupt support (PPC): 2757 2758 There are common interrupt_init() and timer_interrupt() 2759 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2760 for CPU specific initialization. interrupt_init_cpu() 2761 should set decrementer_count to appropriate value. If 2762 CPU resets decrementer automatically after interrupt 2763 (ppc4xx) it should set decrementer_count to zero. 2764 timer_interrupt() calls timer_interrupt_cpu() for CPU 2765 specific handling. If board has watchdog / status_led 2766 / other_activity_monitor it works automatically from 2767 general timer_interrupt(). 2768 2769 2770Board initialization settings: 2771------------------------------ 2772 2773During Initialization u-boot calls a number of board specific functions 2774to allow the preparation of board specific prerequisites, e.g. pin setup 2775before drivers are initialized. To enable these callbacks the 2776following configuration macros have to be defined. Currently this is 2777architecture specific, so please check arch/your_architecture/lib/board.c 2778typically in board_init_f() and board_init_r(). 2779 2780- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2781- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2782- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2783- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2784 2785Configuration Settings: 2786----------------------- 2787 2788- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2789 Optionally it can be defined to support 64-bit memory commands. 2790 2791- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2792 undefine this when you're short of memory. 2793 2794- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2795 width of the commands listed in the 'help' command output. 2796 2797- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2798 prompt for user input. 2799 2800- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2801 2802- CONFIG_SYS_PBSIZE: Buffer size for Console output 2803 2804- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2805 2806- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2807 the application (usually a Linux kernel) when it is 2808 booted 2809 2810- CONFIG_SYS_BAUDRATE_TABLE: 2811 List of legal baudrate settings for this board. 2812 2813- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2814 Begin and End addresses of the area used by the 2815 simple memory test. 2816 2817- CONFIG_SYS_ALT_MEMTEST: 2818 Enable an alternate, more extensive memory test. 2819 2820- CONFIG_SYS_MEMTEST_SCRATCH: 2821 Scratch address used by the alternate memory test 2822 You only need to set this if address zero isn't writeable 2823 2824- CONFIG_SYS_MEM_RESERVE_SECURE 2825 Only implemented for ARMv8 for now. 2826 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2827 is substracted from total RAM and won't be reported to OS. 2828 This memory can be used as secure memory. A variable 2829 gd->arch.secure_ram is used to track the location. In systems 2830 the RAM base is not zero, or RAM is divided into banks, 2831 this variable needs to be recalcuated to get the address. 2832 2833- CONFIG_SYS_MEM_TOP_HIDE: 2834 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2835 this specified memory area will get subtracted from the top 2836 (end) of RAM and won't get "touched" at all by U-Boot. By 2837 fixing up gd->ram_size the Linux kernel should gets passed 2838 the now "corrected" memory size and won't touch it either. 2839 This should work for arch/ppc and arch/powerpc. Only Linux 2840 board ports in arch/powerpc with bootwrapper support that 2841 recalculate the memory size from the SDRAM controller setup 2842 will have to get fixed in Linux additionally. 2843 2844 This option can be used as a workaround for the 440EPx/GRx 2845 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2846 be touched. 2847 2848 WARNING: Please make sure that this value is a multiple of 2849 the Linux page size (normally 4k). If this is not the case, 2850 then the end address of the Linux memory will be located at a 2851 non page size aligned address and this could cause major 2852 problems. 2853 2854- CONFIG_SYS_LOADS_BAUD_CHANGE: 2855 Enable temporary baudrate change while serial download 2856 2857- CONFIG_SYS_SDRAM_BASE: 2858 Physical start address of SDRAM. _Must_ be 0 here. 2859 2860- CONFIG_SYS_FLASH_BASE: 2861 Physical start address of Flash memory. 2862 2863- CONFIG_SYS_MONITOR_BASE: 2864 Physical start address of boot monitor code (set by 2865 make config files to be same as the text base address 2866 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2867 CONFIG_SYS_FLASH_BASE when booting from flash. 2868 2869- CONFIG_SYS_MONITOR_LEN: 2870 Size of memory reserved for monitor code, used to 2871 determine _at_compile_time_ (!) if the environment is 2872 embedded within the U-Boot image, or in a separate 2873 flash sector. 2874 2875- CONFIG_SYS_MALLOC_LEN: 2876 Size of DRAM reserved for malloc() use. 2877 2878- CONFIG_SYS_MALLOC_F_LEN 2879 Size of the malloc() pool for use before relocation. If 2880 this is defined, then a very simple malloc() implementation 2881 will become available before relocation. The address is just 2882 below the global data, and the stack is moved down to make 2883 space. 2884 2885 This feature allocates regions with increasing addresses 2886 within the region. calloc() is supported, but realloc() 2887 is not available. free() is supported but does nothing. 2888 The memory will be freed (or in fact just forgotten) when 2889 U-Boot relocates itself. 2890 2891- CONFIG_SYS_MALLOC_SIMPLE 2892 Provides a simple and small malloc() and calloc() for those 2893 boards which do not use the full malloc in SPL (which is 2894 enabled with CONFIG_SYS_SPL_MALLOC_START). 2895 2896- CONFIG_SYS_NONCACHED_MEMORY: 2897 Size of non-cached memory area. This area of memory will be 2898 typically located right below the malloc() area and mapped 2899 uncached in the MMU. This is useful for drivers that would 2900 otherwise require a lot of explicit cache maintenance. For 2901 some drivers it's also impossible to properly maintain the 2902 cache. For example if the regions that need to be flushed 2903 are not a multiple of the cache-line size, *and* padding 2904 cannot be allocated between the regions to align them (i.e. 2905 if the HW requires a contiguous array of regions, and the 2906 size of each region is not cache-aligned), then a flush of 2907 one region may result in overwriting data that hardware has 2908 written to another region in the same cache-line. This can 2909 happen for example in network drivers where descriptors for 2910 buffers are typically smaller than the CPU cache-line (e.g. 2911 16 bytes vs. 32 or 64 bytes). 2912 2913 Non-cached memory is only supported on 32-bit ARM at present. 2914 2915- CONFIG_SYS_BOOTM_LEN: 2916 Normally compressed uImages are limited to an 2917 uncompressed size of 8 MBytes. If this is not enough, 2918 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2919 to adjust this setting to your needs. 2920 2921- CONFIG_SYS_BOOTMAPSZ: 2922 Maximum size of memory mapped by the startup code of 2923 the Linux kernel; all data that must be processed by 2924 the Linux kernel (bd_info, boot arguments, FDT blob if 2925 used) must be put below this limit, unless "bootm_low" 2926 environment variable is defined and non-zero. In such case 2927 all data for the Linux kernel must be between "bootm_low" 2928 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2929 variable "bootm_mapsize" will override the value of 2930 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2931 then the value in "bootm_size" will be used instead. 2932 2933- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2934 Enable initrd_high functionality. If defined then the 2935 initrd_high feature is enabled and the bootm ramdisk subcommand 2936 is enabled. 2937 2938- CONFIG_SYS_BOOT_GET_CMDLINE: 2939 Enables allocating and saving kernel cmdline in space between 2940 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2941 2942- CONFIG_SYS_BOOT_GET_KBD: 2943 Enables allocating and saving a kernel copy of the bd_info in 2944 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2945 2946- CONFIG_SYS_MAX_FLASH_BANKS: 2947 Max number of Flash memory banks 2948 2949- CONFIG_SYS_MAX_FLASH_SECT: 2950 Max number of sectors on a Flash chip 2951 2952- CONFIG_SYS_FLASH_ERASE_TOUT: 2953 Timeout for Flash erase operations (in ms) 2954 2955- CONFIG_SYS_FLASH_WRITE_TOUT: 2956 Timeout for Flash write operations (in ms) 2957 2958- CONFIG_SYS_FLASH_LOCK_TOUT 2959 Timeout for Flash set sector lock bit operation (in ms) 2960 2961- CONFIG_SYS_FLASH_UNLOCK_TOUT 2962 Timeout for Flash clear lock bits operation (in ms) 2963 2964- CONFIG_SYS_FLASH_PROTECTION 2965 If defined, hardware flash sectors protection is used 2966 instead of U-Boot software protection. 2967 2968- CONFIG_SYS_DIRECT_FLASH_TFTP: 2969 2970 Enable TFTP transfers directly to flash memory; 2971 without this option such a download has to be 2972 performed in two steps: (1) download to RAM, and (2) 2973 copy from RAM to flash. 2974 2975 The two-step approach is usually more reliable, since 2976 you can check if the download worked before you erase 2977 the flash, but in some situations (when system RAM is 2978 too limited to allow for a temporary copy of the 2979 downloaded image) this option may be very useful. 2980 2981- CONFIG_SYS_FLASH_CFI: 2982 Define if the flash driver uses extra elements in the 2983 common flash structure for storing flash geometry. 2984 2985- CONFIG_FLASH_CFI_DRIVER 2986 This option also enables the building of the cfi_flash driver 2987 in the drivers directory 2988 2989- CONFIG_FLASH_CFI_MTD 2990 This option enables the building of the cfi_mtd driver 2991 in the drivers directory. The driver exports CFI flash 2992 to the MTD layer. 2993 2994- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2995 Use buffered writes to flash. 2996 2997- CONFIG_FLASH_SPANSION_S29WS_N 2998 s29ws-n MirrorBit flash has non-standard addresses for buffered 2999 write commands. 3000 3001- CONFIG_SYS_FLASH_QUIET_TEST 3002 If this option is defined, the common CFI flash doesn't 3003 print it's warning upon not recognized FLASH banks. This 3004 is useful, if some of the configured banks are only 3005 optionally available. 3006 3007- CONFIG_FLASH_SHOW_PROGRESS 3008 If defined (must be an integer), print out countdown 3009 digits and dots. Recommended value: 45 (9..1) for 80 3010 column displays, 15 (3..1) for 40 column displays. 3011 3012- CONFIG_FLASH_VERIFY 3013 If defined, the content of the flash (destination) is compared 3014 against the source after the write operation. An error message 3015 will be printed when the contents are not identical. 3016 Please note that this option is useless in nearly all cases, 3017 since such flash programming errors usually are detected earlier 3018 while unprotecting/erasing/programming. Please only enable 3019 this option if you really know what you are doing. 3020 3021- CONFIG_SYS_RX_ETH_BUFFER: 3022 Defines the number of Ethernet receive buffers. On some 3023 Ethernet controllers it is recommended to set this value 3024 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3025 buffers can be full shortly after enabling the interface 3026 on high Ethernet traffic. 3027 Defaults to 4 if not defined. 3028 3029- CONFIG_ENV_MAX_ENTRIES 3030 3031 Maximum number of entries in the hash table that is used 3032 internally to store the environment settings. The default 3033 setting is supposed to be generous and should work in most 3034 cases. This setting can be used to tune behaviour; see 3035 lib/hashtable.c for details. 3036 3037- CONFIG_ENV_FLAGS_LIST_DEFAULT 3038- CONFIG_ENV_FLAGS_LIST_STATIC 3039 Enable validation of the values given to environment variables when 3040 calling env set. Variables can be restricted to only decimal, 3041 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3042 the variables can also be restricted to IP address or MAC address. 3043 3044 The format of the list is: 3045 type_attribute = [s|d|x|b|i|m] 3046 access_attribute = [a|r|o|c] 3047 attributes = type_attribute[access_attribute] 3048 entry = variable_name[:attributes] 3049 list = entry[,list] 3050 3051 The type attributes are: 3052 s - String (default) 3053 d - Decimal 3054 x - Hexadecimal 3055 b - Boolean ([1yYtT|0nNfF]) 3056 i - IP address 3057 m - MAC address 3058 3059 The access attributes are: 3060 a - Any (default) 3061 r - Read-only 3062 o - Write-once 3063 c - Change-default 3064 3065 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3066 Define this to a list (string) to define the ".flags" 3067 environment variable in the default or embedded environment. 3068 3069 - CONFIG_ENV_FLAGS_LIST_STATIC 3070 Define this to a list (string) to define validation that 3071 should be done if an entry is not found in the ".flags" 3072 environment variable. To override a setting in the static 3073 list, simply add an entry for the same variable name to the 3074 ".flags" variable. 3075 3076 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3077 regular expression. This allows multiple variables to define the same 3078 flags without explicitly listing them for each variable. 3079 3080- CONFIG_ENV_ACCESS_IGNORE_FORCE 3081 If defined, don't allow the -f switch to env set override variable 3082 access flags. 3083 3084- CONFIG_USE_STDINT 3085 If stdint.h is available with your toolchain you can define this 3086 option to enable it. You can provide option 'USE_STDINT=1' when 3087 building U-Boot to enable this. 3088 3089The following definitions that deal with the placement and management 3090of environment data (variable area); in general, we support the 3091following configurations: 3092 3093- CONFIG_BUILD_ENVCRC: 3094 3095 Builds up envcrc with the target environment so that external utils 3096 may easily extract it and embed it in final U-Boot images. 3097 3098BE CAREFUL! The first access to the environment happens quite early 3099in U-Boot initialization (when we try to get the setting of for the 3100console baudrate). You *MUST* have mapped your NVRAM area then, or 3101U-Boot will hang. 3102 3103Please note that even with NVRAM we still use a copy of the 3104environment in RAM: we could work on NVRAM directly, but we want to 3105keep settings there always unmodified except somebody uses "saveenv" 3106to save the current settings. 3107 3108BE CAREFUL! For some special cases, the local device can not use 3109"saveenv" command. For example, the local device will get the 3110environment stored in a remote NOR flash by SRIO or PCIE link, 3111but it can not erase, write this NOR flash by SRIO or PCIE interface. 3112 3113- CONFIG_NAND_ENV_DST 3114 3115 Defines address in RAM to which the nand_spl code should copy the 3116 environment. If redundant environment is used, it will be copied to 3117 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3118 3119Please note that the environment is read-only until the monitor 3120has been relocated to RAM and a RAM copy of the environment has been 3121created; also, when using EEPROM you will have to use env_get_f() 3122until then to read environment variables. 3123 3124The environment is protected by a CRC32 checksum. Before the monitor 3125is relocated into RAM, as a result of a bad CRC you will be working 3126with the compiled-in default environment - *silently*!!! [This is 3127necessary, because the first environment variable we need is the 3128"baudrate" setting for the console - if we have a bad CRC, we don't 3129have any device yet where we could complain.] 3130 3131Note: once the monitor has been relocated, then it will complain if 3132the default environment is used; a new CRC is computed as soon as you 3133use the "saveenv" command to store a valid environment. 3134 3135- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3136 Echo the inverted Ethernet link state to the fault LED. 3137 3138 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3139 also needs to be defined. 3140 3141- CONFIG_SYS_FAULT_MII_ADDR: 3142 MII address of the PHY to check for the Ethernet link state. 3143 3144- CONFIG_NS16550_MIN_FUNCTIONS: 3145 Define this if you desire to only have use of the NS16550_init 3146 and NS16550_putc functions for the serial driver located at 3147 drivers/serial/ns16550.c. This option is useful for saving 3148 space for already greatly restricted images, including but not 3149 limited to NAND_SPL configurations. 3150 3151- CONFIG_DISPLAY_BOARDINFO 3152 Display information about the board that U-Boot is running on 3153 when U-Boot starts up. The board function checkboard() is called 3154 to do this. 3155 3156- CONFIG_DISPLAY_BOARDINFO_LATE 3157 Similar to the previous option, but display this information 3158 later, once stdio is running and output goes to the LCD, if 3159 present. 3160 3161- CONFIG_BOARD_SIZE_LIMIT: 3162 Maximum size of the U-Boot image. When defined, the 3163 build system checks that the actual size does not 3164 exceed it. 3165 3166Low Level (hardware related) configuration options: 3167--------------------------------------------------- 3168 3169- CONFIG_SYS_CACHELINE_SIZE: 3170 Cache Line Size of the CPU. 3171 3172- CONFIG_SYS_CCSRBAR_DEFAULT: 3173 Default (power-on reset) physical address of CCSR on Freescale 3174 PowerPC SOCs. 3175 3176- CONFIG_SYS_CCSRBAR: 3177 Virtual address of CCSR. On a 32-bit build, this is typically 3178 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3179 3180- CONFIG_SYS_CCSRBAR_PHYS: 3181 Physical address of CCSR. CCSR can be relocated to a new 3182 physical address, if desired. In this case, this macro should 3183 be set to that address. Otherwise, it should be set to the 3184 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3185 is typically relocated on 36-bit builds. It is recommended 3186 that this macro be defined via the _HIGH and _LOW macros: 3187 3188 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3189 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3190 3191- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3192 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3193 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3194 used in assembly code, so it must not contain typecasts or 3195 integer size suffixes (e.g. "ULL"). 3196 3197- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3198 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3199 used in assembly code, so it must not contain typecasts or 3200 integer size suffixes (e.g. "ULL"). 3201 3202- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3203 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3204 forced to a value that ensures that CCSR is not relocated. 3205 3206- Floppy Disk Support: 3207 CONFIG_SYS_FDC_DRIVE_NUMBER 3208 3209 the default drive number (default value 0) 3210 3211 CONFIG_SYS_ISA_IO_STRIDE 3212 3213 defines the spacing between FDC chipset registers 3214 (default value 1) 3215 3216 CONFIG_SYS_ISA_IO_OFFSET 3217 3218 defines the offset of register from address. It 3219 depends on which part of the data bus is connected to 3220 the FDC chipset. (default value 0) 3221 3222 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3223 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3224 default value. 3225 3226 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3227 fdc_hw_init() is called at the beginning of the FDC 3228 setup. fdc_hw_init() must be provided by the board 3229 source code. It is used to make hardware-dependent 3230 initializations. 3231 3232- CONFIG_IDE_AHB: 3233 Most IDE controllers were designed to be connected with PCI 3234 interface. Only few of them were designed for AHB interface. 3235 When software is doing ATA command and data transfer to 3236 IDE devices through IDE-AHB controller, some additional 3237 registers accessing to these kind of IDE-AHB controller 3238 is required. 3239 3240- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3241 DO NOT CHANGE unless you know exactly what you're 3242 doing! (11-4) [MPC8xx systems only] 3243 3244- CONFIG_SYS_INIT_RAM_ADDR: 3245 3246 Start address of memory area that can be used for 3247 initial data and stack; please note that this must be 3248 writable memory that is working WITHOUT special 3249 initialization, i. e. you CANNOT use normal RAM which 3250 will become available only after programming the 3251 memory controller and running certain initialization 3252 sequences. 3253 3254 U-Boot uses the following memory types: 3255 - MPC8xx: IMMR (internal memory of the CPU) 3256 3257- CONFIG_SYS_GBL_DATA_OFFSET: 3258 3259 Offset of the initial data structure in the memory 3260 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3261 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3262 data is located at the end of the available space 3263 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3264 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3265 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3266 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3267 3268 Note: 3269 On the MPC824X (or other systems that use the data 3270 cache for initial memory) the address chosen for 3271 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3272 point to an otherwise UNUSED address space between 3273 the top of RAM and the start of the PCI space. 3274 3275- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3276 3277- CONFIG_SYS_OR_TIMING_SDRAM: 3278 SDRAM timing 3279 3280- CONFIG_SYS_MAMR_PTA: 3281 periodic timer for refresh 3282 3283- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3284 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3285 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3286 CONFIG_SYS_BR1_PRELIM: 3287 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3288 3289- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3290 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3291 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3292 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3293 3294- CONFIG_PCI_ENUM_ONLY 3295 Only scan through and get the devices on the buses. 3296 Don't do any setup work, presumably because someone or 3297 something has already done it, and we don't need to do it 3298 a second time. Useful for platforms that are pre-booted 3299 by coreboot or similar. 3300 3301- CONFIG_PCI_INDIRECT_BRIDGE: 3302 Enable support for indirect PCI bridges. 3303 3304- CONFIG_SYS_SRIO: 3305 Chip has SRIO or not 3306 3307- CONFIG_SRIO1: 3308 Board has SRIO 1 port available 3309 3310- CONFIG_SRIO2: 3311 Board has SRIO 2 port available 3312 3313- CONFIG_SRIO_PCIE_BOOT_MASTER 3314 Board can support master function for Boot from SRIO and PCIE 3315 3316- CONFIG_SYS_SRIOn_MEM_VIRT: 3317 Virtual Address of SRIO port 'n' memory region 3318 3319- CONFIG_SYS_SRIOn_MEM_PHYS: 3320 Physical Address of SRIO port 'n' memory region 3321 3322- CONFIG_SYS_SRIOn_MEM_SIZE: 3323 Size of SRIO port 'n' memory region 3324 3325- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3326 Defined to tell the NAND controller that the NAND chip is using 3327 a 16 bit bus. 3328 Not all NAND drivers use this symbol. 3329 Example of drivers that use it: 3330 - drivers/mtd/nand/ndfc.c 3331 - drivers/mtd/nand/mxc_nand.c 3332 3333- CONFIG_SYS_NDFC_EBC0_CFG 3334 Sets the EBC0_CFG register for the NDFC. If not defined 3335 a default value will be used. 3336 3337- CONFIG_SPD_EEPROM 3338 Get DDR timing information from an I2C EEPROM. Common 3339 with pluggable memory modules such as SODIMMs 3340 3341 SPD_EEPROM_ADDRESS 3342 I2C address of the SPD EEPROM 3343 3344- CONFIG_SYS_SPD_BUS_NUM 3345 If SPD EEPROM is on an I2C bus other than the first 3346 one, specify here. Note that the value must resolve 3347 to something your driver can deal with. 3348 3349- CONFIG_SYS_DDR_RAW_TIMING 3350 Get DDR timing information from other than SPD. Common with 3351 soldered DDR chips onboard without SPD. DDR raw timing 3352 parameters are extracted from datasheet and hard-coded into 3353 header files or board specific files. 3354 3355- CONFIG_FSL_DDR_INTERACTIVE 3356 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3357 3358- CONFIG_FSL_DDR_SYNC_REFRESH 3359 Enable sync of refresh for multiple controllers. 3360 3361- CONFIG_FSL_DDR_BIST 3362 Enable built-in memory test for Freescale DDR controllers. 3363 3364- CONFIG_SYS_83XX_DDR_USES_CS0 3365 Only for 83xx systems. If specified, then DDR should 3366 be configured using CS0 and CS1 instead of CS2 and CS3. 3367 3368- CONFIG_RMII 3369 Enable RMII mode for all FECs. 3370 Note that this is a global option, we can't 3371 have one FEC in standard MII mode and another in RMII mode. 3372 3373- CONFIG_CRC32_VERIFY 3374 Add a verify option to the crc32 command. 3375 The syntax is: 3376 3377 => crc32 -v <address> <count> <crc32> 3378 3379 Where address/count indicate a memory area 3380 and crc32 is the correct crc32 which the 3381 area should have. 3382 3383- CONFIG_LOOPW 3384 Add the "loopw" memory command. This only takes effect if 3385 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3386 3387- CONFIG_MX_CYCLIC 3388 Add the "mdc" and "mwc" memory commands. These are cyclic 3389 "md/mw" commands. 3390 Examples: 3391 3392 => mdc.b 10 4 500 3393 This command will print 4 bytes (10,11,12,13) each 500 ms. 3394 3395 => mwc.l 100 12345678 10 3396 This command will write 12345678 to address 100 all 10 ms. 3397 3398 This only takes effect if the memory commands are activated 3399 globally (CONFIG_CMD_MEMORY). 3400 3401- CONFIG_SKIP_LOWLEVEL_INIT 3402 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3403 low level initializations (like setting up the memory 3404 controller) are omitted and/or U-Boot does not 3405 relocate itself into RAM. 3406 3407 Normally this variable MUST NOT be defined. The only 3408 exception is when U-Boot is loaded (to RAM) by some 3409 other boot loader or by a debugger which performs 3410 these initializations itself. 3411 3412- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3413 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3414 to be skipped. The normal CP15 init (such as enabling the 3415 instruction cache) is still performed. 3416 3417- CONFIG_SPL_BUILD 3418 Modifies the behaviour of start.S when compiling a loader 3419 that is executed before the actual U-Boot. E.g. when 3420 compiling a NAND SPL. 3421 3422- CONFIG_TPL_BUILD 3423 Modifies the behaviour of start.S when compiling a loader 3424 that is executed after the SPL and before the actual U-Boot. 3425 It is loaded by the SPL. 3426 3427- CONFIG_SYS_MPC85XX_NO_RESETVEC 3428 Only for 85xx systems. If this variable is specified, the section 3429 .resetvec is not kept and the section .bootpg is placed in the 3430 previous 4k of the .text section. 3431 3432- CONFIG_ARCH_MAP_SYSMEM 3433 Generally U-Boot (and in particular the md command) uses 3434 effective address. It is therefore not necessary to regard 3435 U-Boot address as virtual addresses that need to be translated 3436 to physical addresses. However, sandbox requires this, since 3437 it maintains its own little RAM buffer which contains all 3438 addressable memory. This option causes some memory accesses 3439 to be mapped through map_sysmem() / unmap_sysmem(). 3440 3441- CONFIG_X86_RESET_VECTOR 3442 If defined, the x86 reset vector code is included. This is not 3443 needed when U-Boot is running from Coreboot. 3444 3445- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3446 Enables the RTC32K OSC on AM33xx based plattforms 3447 3448- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3449 Option to disable subpage write in NAND driver 3450 driver that uses this: 3451 drivers/mtd/nand/davinci_nand.c 3452 3453Freescale QE/FMAN Firmware Support: 3454----------------------------------- 3455 3456The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3457loading of "firmware", which is encoded in the QE firmware binary format. 3458This firmware often needs to be loaded during U-Boot booting, so macros 3459are used to identify the storage device (NOR flash, SPI, etc) and the address 3460within that device. 3461 3462- CONFIG_SYS_FMAN_FW_ADDR 3463 The address in the storage device where the FMAN microcode is located. The 3464 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3465 is also specified. 3466 3467- CONFIG_SYS_QE_FW_ADDR 3468 The address in the storage device where the QE microcode is located. The 3469 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3470 is also specified. 3471 3472- CONFIG_SYS_QE_FMAN_FW_LENGTH 3473 The maximum possible size of the firmware. The firmware binary format 3474 has a field that specifies the actual size of the firmware, but it 3475 might not be possible to read any part of the firmware unless some 3476 local storage is allocated to hold the entire firmware first. 3477 3478- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3479 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3480 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3481 virtual address in NOR flash. 3482 3483- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3484 Specifies that QE/FMAN firmware is located in NAND flash. 3485 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3486 3487- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3488 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3489 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3490 3491- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3492 Specifies that QE/FMAN firmware is located in the remote (master) 3493 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3494 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3495 window->master inbound window->master LAW->the ucode address in 3496 master's memory space. 3497 3498Freescale Layerscape Management Complex Firmware Support: 3499--------------------------------------------------------- 3500The Freescale Layerscape Management Complex (MC) supports the loading of 3501"firmware". 3502This firmware often needs to be loaded during U-Boot booting, so macros 3503are used to identify the storage device (NOR flash, SPI, etc) and the address 3504within that device. 3505 3506- CONFIG_FSL_MC_ENET 3507 Enable the MC driver for Layerscape SoCs. 3508 3509Freescale Layerscape Debug Server Support: 3510------------------------------------------- 3511The Freescale Layerscape Debug Server Support supports the loading of 3512"Debug Server firmware" and triggering SP boot-rom. 3513This firmware often needs to be loaded during U-Boot booting. 3514 3515- CONFIG_SYS_MC_RSV_MEM_ALIGN 3516 Define alignment of reserved memory MC requires 3517 3518Reproducible builds 3519------------------- 3520 3521In order to achieve reproducible builds, timestamps used in the U-Boot build 3522process have to be set to a fixed value. 3523 3524This is done using the SOURCE_DATE_EPOCH environment variable. 3525SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3526option for U-Boot or an environment variable in U-Boot. 3527 3528SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3529 3530Building the Software: 3531====================== 3532 3533Building U-Boot has been tested in several native build environments 3534and in many different cross environments. Of course we cannot support 3535all possibly existing versions of cross development tools in all 3536(potentially obsolete) versions. In case of tool chain problems we 3537recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3538which is extensively used to build and test U-Boot. 3539 3540If you are not using a native environment, it is assumed that you 3541have GNU cross compiling tools available in your path. In this case, 3542you must set the environment variable CROSS_COMPILE in your shell. 3543Note that no changes to the Makefile or any other source files are 3544necessary. For example using the ELDK on a 4xx CPU, please enter: 3545 3546 $ CROSS_COMPILE=ppc_4xx- 3547 $ export CROSS_COMPILE 3548 3549Note: If you wish to generate Windows versions of the utilities in 3550 the tools directory you can use the MinGW toolchain 3551 (http://www.mingw.org). Set your HOST tools to the MinGW 3552 toolchain and execute 'make tools'. For example: 3553 3554 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3555 3556 Binaries such as tools/mkimage.exe will be created which can 3557 be executed on computers running Windows. 3558 3559U-Boot is intended to be simple to build. After installing the 3560sources you must configure U-Boot for one specific board type. This 3561is done by typing: 3562 3563 make NAME_defconfig 3564 3565where "NAME_defconfig" is the name of one of the existing configu- 3566rations; see boards.cfg for supported names. 3567 3568Note: for some board special configuration names may exist; check if 3569 additional information is available from the board vendor; for 3570 instance, the TQM823L systems are available without (standard) 3571 or with LCD support. You can select such additional "features" 3572 when choosing the configuration, i. e. 3573 3574 make TQM823L_defconfig 3575 - will configure for a plain TQM823L, i. e. no LCD support 3576 3577 make TQM823L_LCD_defconfig 3578 - will configure for a TQM823L with U-Boot console on LCD 3579 3580 etc. 3581 3582 3583Finally, type "make all", and you should get some working U-Boot 3584images ready for download to / installation on your system: 3585 3586- "u-boot.bin" is a raw binary image 3587- "u-boot" is an image in ELF binary format 3588- "u-boot.srec" is in Motorola S-Record format 3589 3590By default the build is performed locally and the objects are saved 3591in the source directory. One of the two methods can be used to change 3592this behavior and build U-Boot to some external directory: 3593 35941. Add O= to the make command line invocations: 3595 3596 make O=/tmp/build distclean 3597 make O=/tmp/build NAME_defconfig 3598 make O=/tmp/build all 3599 36002. Set environment variable KBUILD_OUTPUT to point to the desired location: 3601 3602 export KBUILD_OUTPUT=/tmp/build 3603 make distclean 3604 make NAME_defconfig 3605 make all 3606 3607Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3608variable. 3609 3610User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3611setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3612For example to treat all compiler warnings as errors: 3613 3614 make KCFLAGS=-Werror 3615 3616Please be aware that the Makefiles assume you are using GNU make, so 3617for instance on NetBSD you might need to use "gmake" instead of 3618native "make". 3619 3620 3621If the system board that you have is not listed, then you will need 3622to port U-Boot to your hardware platform. To do this, follow these 3623steps: 3624 36251. Create a new directory to hold your board specific code. Add any 3626 files you need. In your board directory, you will need at least 3627 the "Makefile" and a "<board>.c". 36282. Create a new configuration file "include/configs/<board>.h" for 3629 your board. 36303. If you're porting U-Boot to a new CPU, then also create a new 3631 directory to hold your CPU specific code. Add any files you need. 36324. Run "make <board>_defconfig" with your new name. 36335. Type "make", and you should get a working "u-boot.srec" file 3634 to be installed on your target system. 36356. Debug and solve any problems that might arise. 3636 [Of course, this last step is much harder than it sounds.] 3637 3638 3639Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3640============================================================== 3641 3642If you have modified U-Boot sources (for instance added a new board 3643or support for new devices, a new CPU, etc.) you are expected to 3644provide feedback to the other developers. The feedback normally takes 3645the form of a "patch", i. e. a context diff against a certain (latest 3646official or latest in the git repository) version of U-Boot sources. 3647 3648But before you submit such a patch, please verify that your modifi- 3649cation did not break existing code. At least make sure that *ALL* of 3650the supported boards compile WITHOUT ANY compiler warnings. To do so, 3651just run the buildman script (tools/buildman/buildman), which will 3652configure and build U-Boot for ALL supported system. Be warned, this 3653will take a while. Please see the buildman README, or run 'buildman -H' 3654for documentation. 3655 3656 3657See also "U-Boot Porting Guide" below. 3658 3659 3660Monitor Commands - Overview: 3661============================ 3662 3663go - start application at address 'addr' 3664run - run commands in an environment variable 3665bootm - boot application image from memory 3666bootp - boot image via network using BootP/TFTP protocol 3667bootz - boot zImage from memory 3668tftpboot- boot image via network using TFTP protocol 3669 and env variables "ipaddr" and "serverip" 3670 (and eventually "gatewayip") 3671tftpput - upload a file via network using TFTP protocol 3672rarpboot- boot image via network using RARP/TFTP protocol 3673diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3674loads - load S-Record file over serial line 3675loadb - load binary file over serial line (kermit mode) 3676md - memory display 3677mm - memory modify (auto-incrementing) 3678nm - memory modify (constant address) 3679mw - memory write (fill) 3680cp - memory copy 3681cmp - memory compare 3682crc32 - checksum calculation 3683i2c - I2C sub-system 3684sspi - SPI utility commands 3685base - print or set address offset 3686printenv- print environment variables 3687setenv - set environment variables 3688saveenv - save environment variables to persistent storage 3689protect - enable or disable FLASH write protection 3690erase - erase FLASH memory 3691flinfo - print FLASH memory information 3692nand - NAND memory operations (see doc/README.nand) 3693bdinfo - print Board Info structure 3694iminfo - print header information for application image 3695coninfo - print console devices and informations 3696ide - IDE sub-system 3697loop - infinite loop on address range 3698loopw - infinite write loop on address range 3699mtest - simple RAM test 3700icache - enable or disable instruction cache 3701dcache - enable or disable data cache 3702reset - Perform RESET of the CPU 3703echo - echo args to console 3704version - print monitor version 3705help - print online help 3706? - alias for 'help' 3707 3708 3709Monitor Commands - Detailed Description: 3710======================================== 3711 3712TODO. 3713 3714For now: just type "help <command>". 3715 3716 3717Environment Variables: 3718====================== 3719 3720U-Boot supports user configuration using Environment Variables which 3721can be made persistent by saving to Flash memory. 3722 3723Environment Variables are set using "setenv", printed using 3724"printenv", and saved to Flash using "saveenv". Using "setenv" 3725without a value can be used to delete a variable from the 3726environment. As long as you don't save the environment you are 3727working with an in-memory copy. In case the Flash area containing the 3728environment is erased by accident, a default environment is provided. 3729 3730Some configuration options can be set using Environment Variables. 3731 3732List of environment variables (most likely not complete): 3733 3734 baudrate - see CONFIG_BAUDRATE 3735 3736 bootdelay - see CONFIG_BOOTDELAY 3737 3738 bootcmd - see CONFIG_BOOTCOMMAND 3739 3740 bootargs - Boot arguments when booting an RTOS image 3741 3742 bootfile - Name of the image to load with TFTP 3743 3744 bootm_low - Memory range available for image processing in the bootm 3745 command can be restricted. This variable is given as 3746 a hexadecimal number and defines lowest address allowed 3747 for use by the bootm command. See also "bootm_size" 3748 environment variable. Address defined by "bootm_low" is 3749 also the base of the initial memory mapping for the Linux 3750 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3751 bootm_mapsize. 3752 3753 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3754 This variable is given as a hexadecimal number and it 3755 defines the size of the memory region starting at base 3756 address bootm_low that is accessible by the Linux kernel 3757 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3758 as the default value if it is defined, and bootm_size is 3759 used otherwise. 3760 3761 bootm_size - Memory range available for image processing in the bootm 3762 command can be restricted. This variable is given as 3763 a hexadecimal number and defines the size of the region 3764 allowed for use by the bootm command. See also "bootm_low" 3765 environment variable. 3766 3767 updatefile - Location of the software update file on a TFTP server, used 3768 by the automatic software update feature. Please refer to 3769 documentation in doc/README.update for more details. 3770 3771 autoload - if set to "no" (any string beginning with 'n'), 3772 "bootp" will just load perform a lookup of the 3773 configuration from the BOOTP server, but not try to 3774 load any image using TFTP 3775 3776 autostart - if set to "yes", an image loaded using the "bootp", 3777 "rarpboot", "tftpboot" or "diskboot" commands will 3778 be automatically started (by internally calling 3779 "bootm") 3780 3781 If set to "no", a standalone image passed to the 3782 "bootm" command will be copied to the load address 3783 (and eventually uncompressed), but NOT be started. 3784 This can be used to load and uncompress arbitrary 3785 data. 3786 3787 fdt_high - if set this restricts the maximum address that the 3788 flattened device tree will be copied into upon boot. 3789 For example, if you have a system with 1 GB memory 3790 at physical address 0x10000000, while Linux kernel 3791 only recognizes the first 704 MB as low memory, you 3792 may need to set fdt_high as 0x3C000000 to have the 3793 device tree blob be copied to the maximum address 3794 of the 704 MB low memory, so that Linux kernel can 3795 access it during the boot procedure. 3796 3797 If this is set to the special value 0xFFFFFFFF then 3798 the fdt will not be copied at all on boot. For this 3799 to work it must reside in writable memory, have 3800 sufficient padding on the end of it for u-boot to 3801 add the information it needs into it, and the memory 3802 must be accessible by the kernel. 3803 3804 fdtcontroladdr- if set this is the address of the control flattened 3805 device tree used by U-Boot when CONFIG_OF_CONTROL is 3806 defined. 3807 3808 i2cfast - (PPC405GP|PPC405EP only) 3809 if set to 'y' configures Linux I2C driver for fast 3810 mode (400kHZ). This environment variable is used in 3811 initialization code. So, for changes to be effective 3812 it must be saved and board must be reset. 3813 3814 initrd_high - restrict positioning of initrd images: 3815 If this variable is not set, initrd images will be 3816 copied to the highest possible address in RAM; this 3817 is usually what you want since it allows for 3818 maximum initrd size. If for some reason you want to 3819 make sure that the initrd image is loaded below the 3820 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3821 variable to a value of "no" or "off" or "0". 3822 Alternatively, you can set it to a maximum upper 3823 address to use (U-Boot will still check that it 3824 does not overwrite the U-Boot stack and data). 3825 3826 For instance, when you have a system with 16 MB 3827 RAM, and want to reserve 4 MB from use by Linux, 3828 you can do this by adding "mem=12M" to the value of 3829 the "bootargs" variable. However, now you must make 3830 sure that the initrd image is placed in the first 3831 12 MB as well - this can be done with 3832 3833 setenv initrd_high 00c00000 3834 3835 If you set initrd_high to 0xFFFFFFFF, this is an 3836 indication to U-Boot that all addresses are legal 3837 for the Linux kernel, including addresses in flash 3838 memory. In this case U-Boot will NOT COPY the 3839 ramdisk at all. This may be useful to reduce the 3840 boot time on your system, but requires that this 3841 feature is supported by your Linux kernel. 3842 3843 ipaddr - IP address; needed for tftpboot command 3844 3845 loadaddr - Default load address for commands like "bootp", 3846 "rarpboot", "tftpboot", "loadb" or "diskboot" 3847 3848 loads_echo - see CONFIG_LOADS_ECHO 3849 3850 serverip - TFTP server IP address; needed for tftpboot command 3851 3852 bootretry - see CONFIG_BOOT_RETRY_TIME 3853 3854 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3855 3856 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3857 3858 ethprime - controls which interface is used first. 3859 3860 ethact - controls which interface is currently active. 3861 For example you can do the following 3862 3863 => setenv ethact FEC 3864 => ping 192.168.0.1 # traffic sent on FEC 3865 => setenv ethact SCC 3866 => ping 10.0.0.1 # traffic sent on SCC 3867 3868 ethrotate - When set to "no" U-Boot does not go through all 3869 available network interfaces. 3870 It just stays at the currently selected interface. 3871 3872 netretry - When set to "no" each network operation will 3873 either succeed or fail without retrying. 3874 When set to "once" the network operation will 3875 fail when all the available network interfaces 3876 are tried once without success. 3877 Useful on scripts which control the retry operation 3878 themselves. 3879 3880 npe_ucode - set load address for the NPE microcode 3881 3882 silent_linux - If set then Linux will be told to boot silently, by 3883 changing the console to be empty. If "yes" it will be 3884 made silent. If "no" it will not be made silent. If 3885 unset, then it will be made silent if the U-Boot console 3886 is silent. 3887 3888 tftpsrcp - If this is set, the value is used for TFTP's 3889 UDP source port. 3890 3891 tftpdstp - If this is set, the value is used for TFTP's UDP 3892 destination port instead of the Well Know Port 69. 3893 3894 tftpblocksize - Block size to use for TFTP transfers; if not set, 3895 we use the TFTP server's default block size 3896 3897 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3898 seconds, minimum value is 1000 = 1 second). Defines 3899 when a packet is considered to be lost so it has to 3900 be retransmitted. The default is 5000 = 5 seconds. 3901 Lowering this value may make downloads succeed 3902 faster in networks with high packet loss rates or 3903 with unreliable TFTP servers. 3904 3905 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3906 unit, minimum value = 0). Defines how many timeouts 3907 can happen during a single file transfer before that 3908 transfer is aborted. The default is 10, and 0 means 3909 'no timeouts allowed'. Increasing this value may help 3910 downloads succeed with high packet loss rates, or with 3911 unreliable TFTP servers or client hardware. 3912 3913 vlan - When set to a value < 4095 the traffic over 3914 Ethernet is encapsulated/received over 802.1q 3915 VLAN tagged frames. 3916 3917 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3918 Unsigned value, in milliseconds. If not set, the period will 3919 be either the default (28000), or a value based on 3920 CONFIG_NET_RETRY_COUNT, if defined. This value has 3921 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3922 3923The following image location variables contain the location of images 3924used in booting. The "Image" column gives the role of the image and is 3925not an environment variable name. The other columns are environment 3926variable names. "File Name" gives the name of the file on a TFTP 3927server, "RAM Address" gives the location in RAM the image will be 3928loaded to, and "Flash Location" gives the image's address in NOR 3929flash or offset in NAND flash. 3930 3931*Note* - these variables don't have to be defined for all boards, some 3932boards currently use other variables for these purposes, and some 3933boards use these variables for other purposes. 3934 3935Image File Name RAM Address Flash Location 3936----- --------- ----------- -------------- 3937u-boot u-boot u-boot_addr_r u-boot_addr 3938Linux kernel bootfile kernel_addr_r kernel_addr 3939device tree blob fdtfile fdt_addr_r fdt_addr 3940ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3941 3942The following environment variables may be used and automatically 3943updated by the network boot commands ("bootp" and "rarpboot"), 3944depending the information provided by your boot server: 3945 3946 bootfile - see above 3947 dnsip - IP address of your Domain Name Server 3948 dnsip2 - IP address of your secondary Domain Name Server 3949 gatewayip - IP address of the Gateway (Router) to use 3950 hostname - Target hostname 3951 ipaddr - see above 3952 netmask - Subnet Mask 3953 rootpath - Pathname of the root filesystem on the NFS server 3954 serverip - see above 3955 3956 3957There are two special Environment Variables: 3958 3959 serial# - contains hardware identification information such 3960 as type string and/or serial number 3961 ethaddr - Ethernet address 3962 3963These variables can be set only once (usually during manufacturing of 3964the board). U-Boot refuses to delete or overwrite these variables 3965once they have been set once. 3966 3967 3968Further special Environment Variables: 3969 3970 ver - Contains the U-Boot version string as printed 3971 with the "version" command. This variable is 3972 readonly (see CONFIG_VERSION_VARIABLE). 3973 3974 3975Please note that changes to some configuration parameters may take 3976only effect after the next boot (yes, that's just like Windoze :-). 3977 3978 3979Callback functions for environment variables: 3980--------------------------------------------- 3981 3982For some environment variables, the behavior of u-boot needs to change 3983when their values are changed. This functionality allows functions to 3984be associated with arbitrary variables. On creation, overwrite, or 3985deletion, the callback will provide the opportunity for some side 3986effect to happen or for the change to be rejected. 3987 3988The callbacks are named and associated with a function using the 3989U_BOOT_ENV_CALLBACK macro in your board or driver code. 3990 3991These callbacks are associated with variables in one of two ways. The 3992static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3993in the board configuration to a string that defines a list of 3994associations. The list must be in the following format: 3995 3996 entry = variable_name[:callback_name] 3997 list = entry[,list] 3998 3999If the callback name is not specified, then the callback is deleted. 4000Spaces are also allowed anywhere in the list. 4001 4002Callbacks can also be associated by defining the ".callbacks" variable 4003with the same list format above. Any association in ".callbacks" will 4004override any association in the static list. You can define 4005CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4006".callbacks" environment variable in the default or embedded environment. 4007 4008If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4009regular expression. This allows multiple variables to be connected to 4010the same callback without explicitly listing them all out. 4011 4012 4013Command Line Parsing: 4014===================== 4015 4016There are two different command line parsers available with U-Boot: 4017the old "simple" one, and the much more powerful "hush" shell: 4018 4019Old, simple command line parser: 4020-------------------------------- 4021 4022- supports environment variables (through setenv / saveenv commands) 4023- several commands on one line, separated by ';' 4024- variable substitution using "... ${name} ..." syntax 4025- special characters ('$', ';') can be escaped by prefixing with '\', 4026 for example: 4027 setenv bootcmd bootm \${address} 4028- You can also escape text by enclosing in single apostrophes, for example: 4029 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4030 4031Hush shell: 4032----------- 4033 4034- similar to Bourne shell, with control structures like 4035 if...then...else...fi, for...do...done; while...do...done, 4036 until...do...done, ... 4037- supports environment ("global") variables (through setenv / saveenv 4038 commands) and local shell variables (through standard shell syntax 4039 "name=value"); only environment variables can be used with "run" 4040 command 4041 4042General rules: 4043-------------- 4044 4045(1) If a command line (or an environment variable executed by a "run" 4046 command) contains several commands separated by semicolon, and 4047 one of these commands fails, then the remaining commands will be 4048 executed anyway. 4049 4050(2) If you execute several variables with one call to run (i. e. 4051 calling run with a list of variables as arguments), any failing 4052 command will cause "run" to terminate, i. e. the remaining 4053 variables are not executed. 4054 4055Note for Redundant Ethernet Interfaces: 4056======================================= 4057 4058Some boards come with redundant Ethernet interfaces; U-Boot supports 4059such configurations and is capable of automatic selection of a 4060"working" interface when needed. MAC assignment works as follows: 4061 4062Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4063MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4064"eth1addr" (=>eth1), "eth2addr", ... 4065 4066If the network interface stores some valid MAC address (for instance 4067in SROM), this is used as default address if there is NO correspon- 4068ding setting in the environment; if the corresponding environment 4069variable is set, this overrides the settings in the card; that means: 4070 4071o If the SROM has a valid MAC address, and there is no address in the 4072 environment, the SROM's address is used. 4073 4074o If there is no valid address in the SROM, and a definition in the 4075 environment exists, then the value from the environment variable is 4076 used. 4077 4078o If both the SROM and the environment contain a MAC address, and 4079 both addresses are the same, this MAC address is used. 4080 4081o If both the SROM and the environment contain a MAC address, and the 4082 addresses differ, the value from the environment is used and a 4083 warning is printed. 4084 4085o If neither SROM nor the environment contain a MAC address, an error 4086 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4087 a random, locally-assigned MAC is used. 4088 4089If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4090will be programmed into hardware as part of the initialization process. This 4091may be skipped by setting the appropriate 'ethmacskip' environment variable. 4092The naming convention is as follows: 4093"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4094 4095Image Formats: 4096============== 4097 4098U-Boot is capable of booting (and performing other auxiliary operations on) 4099images in two formats: 4100 4101New uImage format (FIT) 4102----------------------- 4103 4104Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4105to Flattened Device Tree). It allows the use of images with multiple 4106components (several kernels, ramdisks, etc.), with contents protected by 4107SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4108 4109 4110Old uImage format 4111----------------- 4112 4113Old image format is based on binary files which can be basically anything, 4114preceded by a special header; see the definitions in include/image.h for 4115details; basically, the header defines the following image properties: 4116 4117* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4118 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4119 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4120 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4121 INTEGRITY). 4122* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4123 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4124 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4125* Compression Type (uncompressed, gzip, bzip2) 4126* Load Address 4127* Entry Point 4128* Image Name 4129* Image Timestamp 4130 4131The header is marked by a special Magic Number, and both the header 4132and the data portions of the image are secured against corruption by 4133CRC32 checksums. 4134 4135 4136Linux Support: 4137============== 4138 4139Although U-Boot should support any OS or standalone application 4140easily, the main focus has always been on Linux during the design of 4141U-Boot. 4142 4143U-Boot includes many features that so far have been part of some 4144special "boot loader" code within the Linux kernel. Also, any 4145"initrd" images to be used are no longer part of one big Linux image; 4146instead, kernel and "initrd" are separate images. This implementation 4147serves several purposes: 4148 4149- the same features can be used for other OS or standalone 4150 applications (for instance: using compressed images to reduce the 4151 Flash memory footprint) 4152 4153- it becomes much easier to port new Linux kernel versions because 4154 lots of low-level, hardware dependent stuff are done by U-Boot 4155 4156- the same Linux kernel image can now be used with different "initrd" 4157 images; of course this also means that different kernel images can 4158 be run with the same "initrd". This makes testing easier (you don't 4159 have to build a new "zImage.initrd" Linux image when you just 4160 change a file in your "initrd"). Also, a field-upgrade of the 4161 software is easier now. 4162 4163 4164Linux HOWTO: 4165============ 4166 4167Porting Linux to U-Boot based systems: 4168--------------------------------------- 4169 4170U-Boot cannot save you from doing all the necessary modifications to 4171configure the Linux device drivers for use with your target hardware 4172(no, we don't intend to provide a full virtual machine interface to 4173Linux :-). 4174 4175But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4176 4177Just make sure your machine specific header file (for instance 4178include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4179Information structure as we define in include/asm-<arch>/u-boot.h, 4180and make sure that your definition of IMAP_ADDR uses the same value 4181as your U-Boot configuration in CONFIG_SYS_IMMR. 4182 4183Note that U-Boot now has a driver model, a unified model for drivers. 4184If you are adding a new driver, plumb it into driver model. If there 4185is no uclass available, you are encouraged to create one. See 4186doc/driver-model. 4187 4188 4189Configuring the Linux kernel: 4190----------------------------- 4191 4192No specific requirements for U-Boot. Make sure you have some root 4193device (initial ramdisk, NFS) for your target system. 4194 4195 4196Building a Linux Image: 4197----------------------- 4198 4199With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4200not used. If you use recent kernel source, a new build target 4201"uImage" will exist which automatically builds an image usable by 4202U-Boot. Most older kernels also have support for a "pImage" target, 4203which was introduced for our predecessor project PPCBoot and uses a 4204100% compatible format. 4205 4206Example: 4207 4208 make TQM850L_defconfig 4209 make oldconfig 4210 make dep 4211 make uImage 4212 4213The "uImage" build target uses a special tool (in 'tools/mkimage') to 4214encapsulate a compressed Linux kernel image with header information, 4215CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4216 4217* build a standard "vmlinux" kernel image (in ELF binary format): 4218 4219* convert the kernel into a raw binary image: 4220 4221 ${CROSS_COMPILE}-objcopy -O binary \ 4222 -R .note -R .comment \ 4223 -S vmlinux linux.bin 4224 4225* compress the binary image: 4226 4227 gzip -9 linux.bin 4228 4229* package compressed binary image for U-Boot: 4230 4231 mkimage -A ppc -O linux -T kernel -C gzip \ 4232 -a 0 -e 0 -n "Linux Kernel Image" \ 4233 -d linux.bin.gz uImage 4234 4235 4236The "mkimage" tool can also be used to create ramdisk images for use 4237with U-Boot, either separated from the Linux kernel image, or 4238combined into one file. "mkimage" encapsulates the images with a 64 4239byte header containing information about target architecture, 4240operating system, image type, compression method, entry points, time 4241stamp, CRC32 checksums, etc. 4242 4243"mkimage" can be called in two ways: to verify existing images and 4244print the header information, or to build new images. 4245 4246In the first form (with "-l" option) mkimage lists the information 4247contained in the header of an existing U-Boot image; this includes 4248checksum verification: 4249 4250 tools/mkimage -l image 4251 -l ==> list image header information 4252 4253The second form (with "-d" option) is used to build a U-Boot image 4254from a "data file" which is used as image payload: 4255 4256 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4257 -n name -d data_file image 4258 -A ==> set architecture to 'arch' 4259 -O ==> set operating system to 'os' 4260 -T ==> set image type to 'type' 4261 -C ==> set compression type 'comp' 4262 -a ==> set load address to 'addr' (hex) 4263 -e ==> set entry point to 'ep' (hex) 4264 -n ==> set image name to 'name' 4265 -d ==> use image data from 'datafile' 4266 4267Right now, all Linux kernels for PowerPC systems use the same load 4268address (0x00000000), but the entry point address depends on the 4269kernel version: 4270 4271- 2.2.x kernels have the entry point at 0x0000000C, 4272- 2.3.x and later kernels have the entry point at 0x00000000. 4273 4274So a typical call to build a U-Boot image would read: 4275 4276 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4277 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4278 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4279 > examples/uImage.TQM850L 4280 Image Name: 2.4.4 kernel for TQM850L 4281 Created: Wed Jul 19 02:34:59 2000 4282 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4283 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4284 Load Address: 0x00000000 4285 Entry Point: 0x00000000 4286 4287To verify the contents of the image (or check for corruption): 4288 4289 -> tools/mkimage -l examples/uImage.TQM850L 4290 Image Name: 2.4.4 kernel for TQM850L 4291 Created: Wed Jul 19 02:34:59 2000 4292 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4293 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4294 Load Address: 0x00000000 4295 Entry Point: 0x00000000 4296 4297NOTE: for embedded systems where boot time is critical you can trade 4298speed for memory and install an UNCOMPRESSED image instead: this 4299needs more space in Flash, but boots much faster since it does not 4300need to be uncompressed: 4301 4302 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4303 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4304 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4305 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4306 > examples/uImage.TQM850L-uncompressed 4307 Image Name: 2.4.4 kernel for TQM850L 4308 Created: Wed Jul 19 02:34:59 2000 4309 Image Type: PowerPC Linux Kernel Image (uncompressed) 4310 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4311 Load Address: 0x00000000 4312 Entry Point: 0x00000000 4313 4314 4315Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4316when your kernel is intended to use an initial ramdisk: 4317 4318 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4319 > -A ppc -O linux -T ramdisk -C gzip \ 4320 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4321 Image Name: Simple Ramdisk Image 4322 Created: Wed Jan 12 14:01:50 2000 4323 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4324 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4325 Load Address: 0x00000000 4326 Entry Point: 0x00000000 4327 4328The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4329option performs the converse operation of the mkimage's second form (the "-d" 4330option). Given an image built by mkimage, the dumpimage extracts a "data file" 4331from the image: 4332 4333 tools/dumpimage -i image -T type -p position data_file 4334 -i ==> extract from the 'image' a specific 'data_file' 4335 -T ==> set image type to 'type' 4336 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4337 4338 4339Installing a Linux Image: 4340------------------------- 4341 4342To downloading a U-Boot image over the serial (console) interface, 4343you must convert the image to S-Record format: 4344 4345 objcopy -I binary -O srec examples/image examples/image.srec 4346 4347The 'objcopy' does not understand the information in the U-Boot 4348image header, so the resulting S-Record file will be relative to 4349address 0x00000000. To load it to a given address, you need to 4350specify the target address as 'offset' parameter with the 'loads' 4351command. 4352 4353Example: install the image to address 0x40100000 (which on the 4354TQM8xxL is in the first Flash bank): 4355 4356 => erase 40100000 401FFFFF 4357 4358 .......... done 4359 Erased 8 sectors 4360 4361 => loads 40100000 4362 ## Ready for S-Record download ... 4363 ~>examples/image.srec 4364 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4365 ... 4366 15989 15990 15991 15992 4367 [file transfer complete] 4368 [connected] 4369 ## Start Addr = 0x00000000 4370 4371 4372You can check the success of the download using the 'iminfo' command; 4373this includes a checksum verification so you can be sure no data 4374corruption happened: 4375 4376 => imi 40100000 4377 4378 ## Checking Image at 40100000 ... 4379 Image Name: 2.2.13 for initrd on TQM850L 4380 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4381 Data Size: 335725 Bytes = 327 kB = 0 MB 4382 Load Address: 00000000 4383 Entry Point: 0000000c 4384 Verifying Checksum ... OK 4385 4386 4387Boot Linux: 4388----------- 4389 4390The "bootm" command is used to boot an application that is stored in 4391memory (RAM or Flash). In case of a Linux kernel image, the contents 4392of the "bootargs" environment variable is passed to the kernel as 4393parameters. You can check and modify this variable using the 4394"printenv" and "setenv" commands: 4395 4396 4397 => printenv bootargs 4398 bootargs=root=/dev/ram 4399 4400 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4401 4402 => printenv bootargs 4403 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4404 4405 => bootm 40020000 4406 ## Booting Linux kernel at 40020000 ... 4407 Image Name: 2.2.13 for NFS on TQM850L 4408 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4409 Data Size: 381681 Bytes = 372 kB = 0 MB 4410 Load Address: 00000000 4411 Entry Point: 0000000c 4412 Verifying Checksum ... OK 4413 Uncompressing Kernel Image ... OK 4414 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 4415 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4416 time_init: decrementer frequency = 187500000/60 4417 Calibrating delay loop... 49.77 BogoMIPS 4418 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4419 ... 4420 4421If you want to boot a Linux kernel with initial RAM disk, you pass 4422the memory addresses of both the kernel and the initrd image (PPBCOOT 4423format!) to the "bootm" command: 4424 4425 => imi 40100000 40200000 4426 4427 ## Checking Image at 40100000 ... 4428 Image Name: 2.2.13 for initrd on TQM850L 4429 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4430 Data Size: 335725 Bytes = 327 kB = 0 MB 4431 Load Address: 00000000 4432 Entry Point: 0000000c 4433 Verifying Checksum ... OK 4434 4435 ## Checking Image at 40200000 ... 4436 Image Name: Simple Ramdisk Image 4437 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4438 Data Size: 566530 Bytes = 553 kB = 0 MB 4439 Load Address: 00000000 4440 Entry Point: 00000000 4441 Verifying Checksum ... OK 4442 4443 => bootm 40100000 40200000 4444 ## Booting Linux kernel at 40100000 ... 4445 Image Name: 2.2.13 for initrd on TQM850L 4446 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4447 Data Size: 335725 Bytes = 327 kB = 0 MB 4448 Load Address: 00000000 4449 Entry Point: 0000000c 4450 Verifying Checksum ... OK 4451 Uncompressing Kernel Image ... OK 4452 ## Loading RAMDisk Image at 40200000 ... 4453 Image Name: Simple Ramdisk Image 4454 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4455 Data Size: 566530 Bytes = 553 kB = 0 MB 4456 Load Address: 00000000 4457 Entry Point: 00000000 4458 Verifying Checksum ... OK 4459 Loading Ramdisk ... OK 4460 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 4461 Boot arguments: root=/dev/ram 4462 time_init: decrementer frequency = 187500000/60 4463 Calibrating delay loop... 49.77 BogoMIPS 4464 ... 4465 RAMDISK: Compressed image found at block 0 4466 VFS: Mounted root (ext2 filesystem). 4467 4468 bash# 4469 4470Boot Linux and pass a flat device tree: 4471----------- 4472 4473First, U-Boot must be compiled with the appropriate defines. See the section 4474titled "Linux Kernel Interface" above for a more in depth explanation. The 4475following is an example of how to start a kernel and pass an updated 4476flat device tree: 4477 4478=> print oftaddr 4479oftaddr=0x300000 4480=> print oft 4481oft=oftrees/mpc8540ads.dtb 4482=> tftp $oftaddr $oft 4483Speed: 1000, full duplex 4484Using TSEC0 device 4485TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4486Filename 'oftrees/mpc8540ads.dtb'. 4487Load address: 0x300000 4488Loading: # 4489done 4490Bytes transferred = 4106 (100a hex) 4491=> tftp $loadaddr $bootfile 4492Speed: 1000, full duplex 4493Using TSEC0 device 4494TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4495Filename 'uImage'. 4496Load address: 0x200000 4497Loading:############ 4498done 4499Bytes transferred = 1029407 (fb51f hex) 4500=> print loadaddr 4501loadaddr=200000 4502=> print oftaddr 4503oftaddr=0x300000 4504=> bootm $loadaddr - $oftaddr 4505## Booting image at 00200000 ... 4506 Image Name: Linux-2.6.17-dirty 4507 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4508 Data Size: 1029343 Bytes = 1005.2 kB 4509 Load Address: 00000000 4510 Entry Point: 00000000 4511 Verifying Checksum ... OK 4512 Uncompressing Kernel Image ... OK 4513Booting using flat device tree at 0x300000 4514Using MPC85xx ADS machine description 4515Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4516[snip] 4517 4518 4519More About U-Boot Image Types: 4520------------------------------ 4521 4522U-Boot supports the following image types: 4523 4524 "Standalone Programs" are directly runnable in the environment 4525 provided by U-Boot; it is expected that (if they behave 4526 well) you can continue to work in U-Boot after return from 4527 the Standalone Program. 4528 "OS Kernel Images" are usually images of some Embedded OS which 4529 will take over control completely. Usually these programs 4530 will install their own set of exception handlers, device 4531 drivers, set up the MMU, etc. - this means, that you cannot 4532 expect to re-enter U-Boot except by resetting the CPU. 4533 "RAMDisk Images" are more or less just data blocks, and their 4534 parameters (address, size) are passed to an OS kernel that is 4535 being started. 4536 "Multi-File Images" contain several images, typically an OS 4537 (Linux) kernel image and one or more data images like 4538 RAMDisks. This construct is useful for instance when you want 4539 to boot over the network using BOOTP etc., where the boot 4540 server provides just a single image file, but you want to get 4541 for instance an OS kernel and a RAMDisk image. 4542 4543 "Multi-File Images" start with a list of image sizes, each 4544 image size (in bytes) specified by an "uint32_t" in network 4545 byte order. This list is terminated by an "(uint32_t)0". 4546 Immediately after the terminating 0 follow the images, one by 4547 one, all aligned on "uint32_t" boundaries (size rounded up to 4548 a multiple of 4 bytes). 4549 4550 "Firmware Images" are binary images containing firmware (like 4551 U-Boot or FPGA images) which usually will be programmed to 4552 flash memory. 4553 4554 "Script files" are command sequences that will be executed by 4555 U-Boot's command interpreter; this feature is especially 4556 useful when you configure U-Boot to use a real shell (hush) 4557 as command interpreter. 4558 4559Booting the Linux zImage: 4560------------------------- 4561 4562On some platforms, it's possible to boot Linux zImage. This is done 4563using the "bootz" command. The syntax of "bootz" command is the same 4564as the syntax of "bootm" command. 4565 4566Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4567kernel with raw initrd images. The syntax is slightly different, the 4568address of the initrd must be augmented by it's size, in the following 4569format: "<initrd addres>:<initrd size>". 4570 4571 4572Standalone HOWTO: 4573================= 4574 4575One of the features of U-Boot is that you can dynamically load and 4576run "standalone" applications, which can use some resources of 4577U-Boot like console I/O functions or interrupt services. 4578 4579Two simple examples are included with the sources: 4580 4581"Hello World" Demo: 4582------------------- 4583 4584'examples/hello_world.c' contains a small "Hello World" Demo 4585application; it is automatically compiled when you build U-Boot. 4586It's configured to run at address 0x00040004, so you can play with it 4587like that: 4588 4589 => loads 4590 ## Ready for S-Record download ... 4591 ~>examples/hello_world.srec 4592 1 2 3 4 5 6 7 8 9 10 11 ... 4593 [file transfer complete] 4594 [connected] 4595 ## Start Addr = 0x00040004 4596 4597 => go 40004 Hello World! This is a test. 4598 ## Starting application at 0x00040004 ... 4599 Hello World 4600 argc = 7 4601 argv[0] = "40004" 4602 argv[1] = "Hello" 4603 argv[2] = "World!" 4604 argv[3] = "This" 4605 argv[4] = "is" 4606 argv[5] = "a" 4607 argv[6] = "test." 4608 argv[7] = "<NULL>" 4609 Hit any key to exit ... 4610 4611 ## Application terminated, rc = 0x0 4612 4613Another example, which demonstrates how to register a CPM interrupt 4614handler with the U-Boot code, can be found in 'examples/timer.c'. 4615Here, a CPM timer is set up to generate an interrupt every second. 4616The interrupt service routine is trivial, just printing a '.' 4617character, but this is just a demo program. The application can be 4618controlled by the following keys: 4619 4620 ? - print current values og the CPM Timer registers 4621 b - enable interrupts and start timer 4622 e - stop timer and disable interrupts 4623 q - quit application 4624 4625 => loads 4626 ## Ready for S-Record download ... 4627 ~>examples/timer.srec 4628 1 2 3 4 5 6 7 8 9 10 11 ... 4629 [file transfer complete] 4630 [connected] 4631 ## Start Addr = 0x00040004 4632 4633 => go 40004 4634 ## Starting application at 0x00040004 ... 4635 TIMERS=0xfff00980 4636 Using timer 1 4637 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4638 4639Hit 'b': 4640 [q, b, e, ?] Set interval 1000000 us 4641 Enabling timer 4642Hit '?': 4643 [q, b, e, ?] ........ 4644 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4645Hit '?': 4646 [q, b, e, ?] . 4647 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4648Hit '?': 4649 [q, b, e, ?] . 4650 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4651Hit '?': 4652 [q, b, e, ?] . 4653 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4654Hit 'e': 4655 [q, b, e, ?] ...Stopping timer 4656Hit 'q': 4657 [q, b, e, ?] ## Application terminated, rc = 0x0 4658 4659 4660Minicom warning: 4661================ 4662 4663Over time, many people have reported problems when trying to use the 4664"minicom" terminal emulation program for serial download. I (wd) 4665consider minicom to be broken, and recommend not to use it. Under 4666Unix, I recommend to use C-Kermit for general purpose use (and 4667especially for kermit binary protocol download ("loadb" command), and 4668use "cu" for S-Record download ("loads" command). See 4669http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4670for help with kermit. 4671 4672 4673Nevertheless, if you absolutely want to use it try adding this 4674configuration to your "File transfer protocols" section: 4675 4676 Name Program Name U/D FullScr IO-Red. Multi 4677 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4678 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4679 4680 4681NetBSD Notes: 4682============= 4683 4684Starting at version 0.9.2, U-Boot supports NetBSD both as host 4685(build U-Boot) and target system (boots NetBSD/mpc8xx). 4686 4687Building requires a cross environment; it is known to work on 4688NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4689need gmake since the Makefiles are not compatible with BSD make). 4690Note that the cross-powerpc package does not install include files; 4691attempting to build U-Boot will fail because <machine/ansi.h> is 4692missing. This file has to be installed and patched manually: 4693 4694 # cd /usr/pkg/cross/powerpc-netbsd/include 4695 # mkdir powerpc 4696 # ln -s powerpc machine 4697 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4698 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4699 4700Native builds *don't* work due to incompatibilities between native 4701and U-Boot include files. 4702 4703Booting assumes that (the first part of) the image booted is a 4704stage-2 loader which in turn loads and then invokes the kernel 4705proper. Loader sources will eventually appear in the NetBSD source 4706tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4707meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4708 4709 4710Implementation Internals: 4711========================= 4712 4713The following is not intended to be a complete description of every 4714implementation detail. However, it should help to understand the 4715inner workings of U-Boot and make it easier to port it to custom 4716hardware. 4717 4718 4719Initial Stack, Global Data: 4720--------------------------- 4721 4722The implementation of U-Boot is complicated by the fact that U-Boot 4723starts running out of ROM (flash memory), usually without access to 4724system RAM (because the memory controller is not initialized yet). 4725This means that we don't have writable Data or BSS segments, and BSS 4726is not initialized as zero. To be able to get a C environment working 4727at all, we have to allocate at least a minimal stack. Implementation 4728options for this are defined and restricted by the CPU used: Some CPU 4729models provide on-chip memory (like the IMMR area on MPC8xx and 4730MPC826x processors), on others (parts of) the data cache can be 4731locked as (mis-) used as memory, etc. 4732 4733 Chris Hallinan posted a good summary of these issues to the 4734 U-Boot mailing list: 4735 4736 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4737 From: "Chris Hallinan" <clh@net1plus.com> 4738 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4739 ... 4740 4741 Correct me if I'm wrong, folks, but the way I understand it 4742 is this: Using DCACHE as initial RAM for Stack, etc, does not 4743 require any physical RAM backing up the cache. The cleverness 4744 is that the cache is being used as a temporary supply of 4745 necessary storage before the SDRAM controller is setup. It's 4746 beyond the scope of this list to explain the details, but you 4747 can see how this works by studying the cache architecture and 4748 operation in the architecture and processor-specific manuals. 4749 4750 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4751 is another option for the system designer to use as an 4752 initial stack/RAM area prior to SDRAM being available. Either 4753 option should work for you. Using CS 4 should be fine if your 4754 board designers haven't used it for something that would 4755 cause you grief during the initial boot! It is frequently not 4756 used. 4757 4758 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4759 with your processor/board/system design. The default value 4760 you will find in any recent u-boot distribution in 4761 walnut.h should work for you. I'd set it to a value larger 4762 than your SDRAM module. If you have a 64MB SDRAM module, set 4763 it above 400_0000. Just make sure your board has no resources 4764 that are supposed to respond to that address! That code in 4765 start.S has been around a while and should work as is when 4766 you get the config right. 4767 4768 -Chris Hallinan 4769 DS4.COM, Inc. 4770 4771It is essential to remember this, since it has some impact on the C 4772code for the initialization procedures: 4773 4774* Initialized global data (data segment) is read-only. Do not attempt 4775 to write it. 4776 4777* Do not use any uninitialized global data (or implicitly initialized 4778 as zero data - BSS segment) at all - this is undefined, initiali- 4779 zation is performed later (when relocating to RAM). 4780 4781* Stack space is very limited. Avoid big data buffers or things like 4782 that. 4783 4784Having only the stack as writable memory limits means we cannot use 4785normal global data to share information between the code. But it 4786turned out that the implementation of U-Boot can be greatly 4787simplified by making a global data structure (gd_t) available to all 4788functions. We could pass a pointer to this data as argument to _all_ 4789functions, but this would bloat the code. Instead we use a feature of 4790the GCC compiler (Global Register Variables) to share the data: we 4791place a pointer (gd) to the global data into a register which we 4792reserve for this purpose. 4793 4794When choosing a register for such a purpose we are restricted by the 4795relevant (E)ABI specifications for the current architecture, and by 4796GCC's implementation. 4797 4798For PowerPC, the following registers have specific use: 4799 R1: stack pointer 4800 R2: reserved for system use 4801 R3-R4: parameter passing and return values 4802 R5-R10: parameter passing 4803 R13: small data area pointer 4804 R30: GOT pointer 4805 R31: frame pointer 4806 4807 (U-Boot also uses R12 as internal GOT pointer. r12 4808 is a volatile register so r12 needs to be reset when 4809 going back and forth between asm and C) 4810 4811 ==> U-Boot will use R2 to hold a pointer to the global data 4812 4813 Note: on PPC, we could use a static initializer (since the 4814 address of the global data structure is known at compile time), 4815 but it turned out that reserving a register results in somewhat 4816 smaller code - although the code savings are not that big (on 4817 average for all boards 752 bytes for the whole U-Boot image, 4818 624 text + 127 data). 4819 4820On ARM, the following registers are used: 4821 4822 R0: function argument word/integer result 4823 R1-R3: function argument word 4824 R9: platform specific 4825 R10: stack limit (used only if stack checking is enabled) 4826 R11: argument (frame) pointer 4827 R12: temporary workspace 4828 R13: stack pointer 4829 R14: link register 4830 R15: program counter 4831 4832 ==> U-Boot will use R9 to hold a pointer to the global data 4833 4834 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4835 4836On Nios II, the ABI is documented here: 4837 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4838 4839 ==> U-Boot will use gp to hold a pointer to the global data 4840 4841 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4842 to access small data sections, so gp is free. 4843 4844On NDS32, the following registers are used: 4845 4846 R0-R1: argument/return 4847 R2-R5: argument 4848 R15: temporary register for assembler 4849 R16: trampoline register 4850 R28: frame pointer (FP) 4851 R29: global pointer (GP) 4852 R30: link register (LP) 4853 R31: stack pointer (SP) 4854 PC: program counter (PC) 4855 4856 ==> U-Boot will use R10 to hold a pointer to the global data 4857 4858NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4859or current versions of GCC may "optimize" the code too much. 4860 4861On RISC-V, the following registers are used: 4862 4863 x0: hard-wired zero (zero) 4864 x1: return address (ra) 4865 x2: stack pointer (sp) 4866 x3: global pointer (gp) 4867 x4: thread pointer (tp) 4868 x5: link register (t0) 4869 x8: frame pointer (fp) 4870 x10-x11: arguments/return values (a0-1) 4871 x12-x17: arguments (a2-7) 4872 x28-31: temporaries (t3-6) 4873 pc: program counter (pc) 4874 4875 ==> U-Boot will use gp to hold a pointer to the global data 4876 4877Memory Management: 4878------------------ 4879 4880U-Boot runs in system state and uses physical addresses, i.e. the 4881MMU is not used either for address mapping nor for memory protection. 4882 4883The available memory is mapped to fixed addresses using the memory 4884controller. In this process, a contiguous block is formed for each 4885memory type (Flash, SDRAM, SRAM), even when it consists of several 4886physical memory banks. 4887 4888U-Boot is installed in the first 128 kB of the first Flash bank (on 4889TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4890booting and sizing and initializing DRAM, the code relocates itself 4891to the upper end of DRAM. Immediately below the U-Boot code some 4892memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4893configuration setting]. Below that, a structure with global Board 4894Info data is placed, followed by the stack (growing downward). 4895 4896Additionally, some exception handler code is copied to the low 8 kB 4897of DRAM (0x00000000 ... 0x00001FFF). 4898 4899So a typical memory configuration with 16 MB of DRAM could look like 4900this: 4901 4902 0x0000 0000 Exception Vector code 4903 : 4904 0x0000 1FFF 4905 0x0000 2000 Free for Application Use 4906 : 4907 : 4908 4909 : 4910 : 4911 0x00FB FF20 Monitor Stack (Growing downward) 4912 0x00FB FFAC Board Info Data and permanent copy of global data 4913 0x00FC 0000 Malloc Arena 4914 : 4915 0x00FD FFFF 4916 0x00FE 0000 RAM Copy of Monitor Code 4917 ... eventually: LCD or video framebuffer 4918 ... eventually: pRAM (Protected RAM - unchanged by reset) 4919 0x00FF FFFF [End of RAM] 4920 4921 4922System Initialization: 4923---------------------- 4924 4925In the reset configuration, U-Boot starts at the reset entry point 4926(on most PowerPC systems at address 0x00000100). Because of the reset 4927configuration for CS0# this is a mirror of the on board Flash memory. 4928To be able to re-map memory U-Boot then jumps to its link address. 4929To be able to implement the initialization code in C, a (small!) 4930initial stack is set up in the internal Dual Ported RAM (in case CPUs 4931which provide such a feature like), or in a locked part of the data 4932cache. After that, U-Boot initializes the CPU core, the caches and 4933the SIU. 4934 4935Next, all (potentially) available memory banks are mapped using a 4936preliminary mapping. For example, we put them on 512 MB boundaries 4937(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4938on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4939programmed for SDRAM access. Using the temporary configuration, a 4940simple memory test is run that determines the size of the SDRAM 4941banks. 4942 4943When there is more than one SDRAM bank, and the banks are of 4944different size, the largest is mapped first. For equal size, the first 4945bank (CS2#) is mapped first. The first mapping is always for address 49460x00000000, with any additional banks following immediately to create 4947contiguous memory starting from 0. 4948 4949Then, the monitor installs itself at the upper end of the SDRAM area 4950and allocates memory for use by malloc() and for the global Board 4951Info data; also, the exception vector code is copied to the low RAM 4952pages, and the final stack is set up. 4953 4954Only after this relocation will you have a "normal" C environment; 4955until that you are restricted in several ways, mostly because you are 4956running from ROM, and because the code will have to be relocated to a 4957new address in RAM. 4958 4959 4960U-Boot Porting Guide: 4961---------------------- 4962 4963[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4964list, October 2002] 4965 4966 4967int main(int argc, char *argv[]) 4968{ 4969 sighandler_t no_more_time; 4970 4971 signal(SIGALRM, no_more_time); 4972 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4973 4974 if (available_money > available_manpower) { 4975 Pay consultant to port U-Boot; 4976 return 0; 4977 } 4978 4979 Download latest U-Boot source; 4980 4981 Subscribe to u-boot mailing list; 4982 4983 if (clueless) 4984 email("Hi, I am new to U-Boot, how do I get started?"); 4985 4986 while (learning) { 4987 Read the README file in the top level directory; 4988 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4989 Read applicable doc/*.README; 4990 Read the source, Luke; 4991 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4992 } 4993 4994 if (available_money > toLocalCurrency ($2500)) 4995 Buy a BDI3000; 4996 else 4997 Add a lot of aggravation and time; 4998 4999 if (a similar board exists) { /* hopefully... */ 5000 cp -a board/<similar> board/<myboard> 5001 cp include/configs/<similar>.h include/configs/<myboard>.h 5002 } else { 5003 Create your own board support subdirectory; 5004 Create your own board include/configs/<myboard>.h file; 5005 } 5006 Edit new board/<myboard> files 5007 Edit new include/configs/<myboard>.h 5008 5009 while (!accepted) { 5010 while (!running) { 5011 do { 5012 Add / modify source code; 5013 } until (compiles); 5014 Debug; 5015 if (clueless) 5016 email("Hi, I am having problems..."); 5017 } 5018 Send patch file to the U-Boot email list; 5019 if (reasonable critiques) 5020 Incorporate improvements from email list code review; 5021 else 5022 Defend code as written; 5023 } 5024 5025 return 0; 5026} 5027 5028void no_more_time (int sig) 5029{ 5030 hire_a_guru(); 5031} 5032 5033 5034Coding Standards: 5035----------------- 5036 5037All contributions to U-Boot should conform to the Linux kernel 5038coding style; see the kernel coding style guide at 5039https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 5040script "scripts/Lindent" in your Linux kernel source directory. 5041 5042Source files originating from a different project (for example the 5043MTD subsystem) are generally exempt from these guidelines and are not 5044reformatted to ease subsequent migration to newer versions of those 5045sources. 5046 5047Please note that U-Boot is implemented in C (and to some small parts in 5048Assembler); no C++ is used, so please do not use C++ style comments (//) 5049in your code. 5050 5051Please also stick to the following formatting rules: 5052- remove any trailing white space 5053- use TAB characters for indentation and vertical alignment, not spaces 5054- make sure NOT to use DOS '\r\n' line feeds 5055- do not add more than 2 consecutive empty lines to source files 5056- do not add trailing empty lines to source files 5057 5058Submissions which do not conform to the standards may be returned 5059with a request to reformat the changes. 5060 5061 5062Submitting Patches: 5063------------------- 5064 5065Since the number of patches for U-Boot is growing, we need to 5066establish some rules. Submissions which do not conform to these rules 5067may be rejected, even when they contain important and valuable stuff. 5068 5069Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5070 5071Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5072see https://lists.denx.de/listinfo/u-boot 5073 5074When you send a patch, please include the following information with 5075it: 5076 5077* For bug fixes: a description of the bug and how your patch fixes 5078 this bug. Please try to include a way of demonstrating that the 5079 patch actually fixes something. 5080 5081* For new features: a description of the feature and your 5082 implementation. 5083 5084* A CHANGELOG entry as plaintext (separate from the patch) 5085 5086* For major contributions, add a MAINTAINERS file with your 5087 information and associated file and directory references. 5088 5089* When you add support for a new board, don't forget to add a 5090 maintainer e-mail address to the boards.cfg file, too. 5091 5092* If your patch adds new configuration options, don't forget to 5093 document these in the README file. 5094 5095* The patch itself. If you are using git (which is *strongly* 5096 recommended) you can easily generate the patch using the 5097 "git format-patch". If you then use "git send-email" to send it to 5098 the U-Boot mailing list, you will avoid most of the common problems 5099 with some other mail clients. 5100 5101 If you cannot use git, use "diff -purN OLD NEW". If your version of 5102 diff does not support these options, then get the latest version of 5103 GNU diff. 5104 5105 The current directory when running this command shall be the parent 5106 directory of the U-Boot source tree (i. e. please make sure that 5107 your patch includes sufficient directory information for the 5108 affected files). 5109 5110 We prefer patches as plain text. MIME attachments are discouraged, 5111 and compressed attachments must not be used. 5112 5113* If one logical set of modifications affects or creates several 5114 files, all these changes shall be submitted in a SINGLE patch file. 5115 5116* Changesets that contain different, unrelated modifications shall be 5117 submitted as SEPARATE patches, one patch per changeset. 5118 5119 5120Notes: 5121 5122* Before sending the patch, run the buildman script on your patched 5123 source tree and make sure that no errors or warnings are reported 5124 for any of the boards. 5125 5126* Keep your modifications to the necessary minimum: A patch 5127 containing several unrelated changes or arbitrary reformats will be 5128 returned with a request to re-formatting / split it. 5129 5130* If you modify existing code, make sure that your new code does not 5131 add to the memory footprint of the code ;-) Small is beautiful! 5132 When adding new features, these should compile conditionally only 5133 (using #ifdef), and the resulting code with the new feature 5134 disabled must not need more memory than the old code without your 5135 modification. 5136 5137* Remember that there is a size limit of 100 kB per message on the 5138 u-boot mailing list. Bigger patches will be moderated. If they are 5139 reasonable and not too big, they will be acknowledged. But patches 5140 bigger than the size limit should be avoided. 5141