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_ADDR 1424 1425 The address of PHY on MII bus. 1426 1427 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1428 1429 The clock frequency of the MII bus 1430 1431 CONFIG_PHY_RESET_DELAY 1432 1433 Some PHY like Intel LXT971A need extra delay after 1434 reset before any MII register access is possible. 1435 For such PHY, set this option to the usec delay 1436 required. (minimum 300usec for LXT971A) 1437 1438 CONFIG_PHY_CMD_DELAY (ppc4xx) 1439 1440 Some PHY like Intel LXT971A need extra delay after 1441 command issued before MII status register can be read 1442 1443- IP address: 1444 CONFIG_IPADDR 1445 1446 Define a default value for the IP address to use for 1447 the default Ethernet interface, in case this is not 1448 determined through e.g. bootp. 1449 (Environment variable "ipaddr") 1450 1451- Server IP address: 1452 CONFIG_SERVERIP 1453 1454 Defines a default value for the IP address of a TFTP 1455 server to contact when using the "tftboot" command. 1456 (Environment variable "serverip") 1457 1458 CONFIG_KEEP_SERVERADDR 1459 1460 Keeps the server's MAC address, in the env 'serveraddr' 1461 for passing to bootargs (like Linux's netconsole option) 1462 1463- Gateway IP address: 1464 CONFIG_GATEWAYIP 1465 1466 Defines a default value for the IP address of the 1467 default router where packets to other networks are 1468 sent to. 1469 (Environment variable "gatewayip") 1470 1471- Subnet mask: 1472 CONFIG_NETMASK 1473 1474 Defines a default value for the subnet mask (or 1475 routing prefix) which is used to determine if an IP 1476 address belongs to the local subnet or needs to be 1477 forwarded through a router. 1478 (Environment variable "netmask") 1479 1480- Multicast TFTP Mode: 1481 CONFIG_MCAST_TFTP 1482 1483 Defines whether you want to support multicast TFTP as per 1484 rfc-2090; for example to work with atftp. Lets lots of targets 1485 tftp down the same boot image concurrently. Note: the Ethernet 1486 driver in use must provide a function: mcast() to join/leave a 1487 multicast group. 1488 1489- BOOTP Recovery Mode: 1490 CONFIG_BOOTP_RANDOM_DELAY 1491 1492 If you have many targets in a network that try to 1493 boot using BOOTP, you may want to avoid that all 1494 systems send out BOOTP requests at precisely the same 1495 moment (which would happen for instance at recovery 1496 from a power failure, when all systems will try to 1497 boot, thus flooding the BOOTP server. Defining 1498 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1499 inserted before sending out BOOTP requests. The 1500 following delays are inserted then: 1501 1502 1st BOOTP request: delay 0 ... 1 sec 1503 2nd BOOTP request: delay 0 ... 2 sec 1504 3rd BOOTP request: delay 0 ... 4 sec 1505 4th and following 1506 BOOTP requests: delay 0 ... 8 sec 1507 1508 CONFIG_BOOTP_ID_CACHE_SIZE 1509 1510 BOOTP packets are uniquely identified using a 32-bit ID. The 1511 server will copy the ID from client requests to responses and 1512 U-Boot will use this to determine if it is the destination of 1513 an incoming response. Some servers will check that addresses 1514 aren't in use before handing them out (usually using an ARP 1515 ping) and therefore take up to a few hundred milliseconds to 1516 respond. Network congestion may also influence the time it 1517 takes for a response to make it back to the client. If that 1518 time is too long, U-Boot will retransmit requests. In order 1519 to allow earlier responses to still be accepted after these 1520 retransmissions, U-Boot's BOOTP client keeps a small cache of 1521 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1522 cache. The default is to keep IDs for up to four outstanding 1523 requests. Increasing this will allow U-Boot to accept offers 1524 from a BOOTP client in networks with unusually high latency. 1525 1526- DHCP Advanced Options: 1527 You can fine tune the DHCP functionality by defining 1528 CONFIG_BOOTP_* symbols: 1529 1530 CONFIG_BOOTP_NISDOMAIN 1531 CONFIG_BOOTP_BOOTFILESIZE 1532 CONFIG_BOOTP_SEND_HOSTNAME 1533 CONFIG_BOOTP_NTPSERVER 1534 CONFIG_BOOTP_TIMEOFFSET 1535 CONFIG_BOOTP_VENDOREX 1536 CONFIG_BOOTP_MAY_FAIL 1537 1538 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1539 environment variable, not the BOOTP server. 1540 1541 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1542 after the configured retry count, the call will fail 1543 instead of starting over. This can be used to fail over 1544 to Link-local IP address configuration if the DHCP server 1545 is not available. 1546 1547 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1548 to do a dynamic update of a DNS server. To do this, they 1549 need the hostname of the DHCP requester. 1550 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1551 of the "hostname" environment variable is passed as 1552 option 12 to the DHCP server. 1553 1554 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1555 1556 A 32bit value in microseconds for a delay between 1557 receiving a "DHCP Offer" and sending the "DHCP Request". 1558 This fixes a problem with certain DHCP servers that don't 1559 respond 100% of the time to a "DHCP request". E.g. On an 1560 AT91RM9200 processor running at 180MHz, this delay needed 1561 to be *at least* 15,000 usec before a Windows Server 2003 1562 DHCP server would reply 100% of the time. I recommend at 1563 least 50,000 usec to be safe. The alternative is to hope 1564 that one of the retries will be successful but note that 1565 the DHCP timeout and retry process takes a longer than 1566 this delay. 1567 1568 - Link-local IP address negotiation: 1569 Negotiate with other link-local clients on the local network 1570 for an address that doesn't require explicit configuration. 1571 This is especially useful if a DHCP server cannot be guaranteed 1572 to exist in all environments that the device must operate. 1573 1574 See doc/README.link-local for more information. 1575 1576 - MAC address from environment variables 1577 1578 FDT_SEQ_MACADDR_FROM_ENV 1579 1580 Fix-up device tree with MAC addresses fetched sequentially from 1581 environment variables. This config work on assumption that 1582 non-usable ethernet node of device-tree are either not present 1583 or their status has been marked as "disabled". 1584 1585 - CDP Options: 1586 CONFIG_CDP_DEVICE_ID 1587 1588 The device id used in CDP trigger frames. 1589 1590 CONFIG_CDP_DEVICE_ID_PREFIX 1591 1592 A two character string which is prefixed to the MAC address 1593 of the device. 1594 1595 CONFIG_CDP_PORT_ID 1596 1597 A printf format string which contains the ascii name of 1598 the port. Normally is set to "eth%d" which sets 1599 eth0 for the first Ethernet, eth1 for the second etc. 1600 1601 CONFIG_CDP_CAPABILITIES 1602 1603 A 32bit integer which indicates the device capabilities; 1604 0x00000010 for a normal host which does not forwards. 1605 1606 CONFIG_CDP_VERSION 1607 1608 An ascii string containing the version of the software. 1609 1610 CONFIG_CDP_PLATFORM 1611 1612 An ascii string containing the name of the platform. 1613 1614 CONFIG_CDP_TRIGGER 1615 1616 A 32bit integer sent on the trigger. 1617 1618 CONFIG_CDP_POWER_CONSUMPTION 1619 1620 A 16bit integer containing the power consumption of the 1621 device in .1 of milliwatts. 1622 1623 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1624 1625 A byte containing the id of the VLAN. 1626 1627- Status LED: CONFIG_LED_STATUS 1628 1629 Several configurations allow to display the current 1630 status using a LED. For instance, the LED will blink 1631 fast while running U-Boot code, stop blinking as 1632 soon as a reply to a BOOTP request was received, and 1633 start blinking slow once the Linux kernel is running 1634 (supported by a status LED driver in the Linux 1635 kernel). Defining CONFIG_LED_STATUS enables this 1636 feature in U-Boot. 1637 1638 Additional options: 1639 1640 CONFIG_LED_STATUS_GPIO 1641 The status LED can be connected to a GPIO pin. 1642 In such cases, the gpio_led driver can be used as a 1643 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1644 to include the gpio_led driver in the U-Boot binary. 1645 1646 CONFIG_GPIO_LED_INVERTED_TABLE 1647 Some GPIO connected LEDs may have inverted polarity in which 1648 case the GPIO high value corresponds to LED off state and 1649 GPIO low value corresponds to LED on state. 1650 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1651 with a list of GPIO LEDs that have inverted polarity. 1652 1653- I2C Support: CONFIG_SYS_I2C 1654 1655 This enable the NEW i2c subsystem, and will allow you to use 1656 i2c commands at the u-boot command line (as long as you set 1657 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1658 based realtime clock chips or other i2c devices. See 1659 common/cmd_i2c.c for a description of the command line 1660 interface. 1661 1662 ported i2c driver to the new framework: 1663 - drivers/i2c/soft_i2c.c: 1664 - activate first bus with CONFIG_SYS_I2C_SOFT define 1665 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1666 for defining speed and slave address 1667 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1668 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1669 for defining speed and slave address 1670 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1671 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1672 for defining speed and slave address 1673 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1674 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1675 for defining speed and slave address 1676 1677 - drivers/i2c/fsl_i2c.c: 1678 - activate i2c driver with CONFIG_SYS_I2C_FSL 1679 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1680 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1681 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1682 bus. 1683 - If your board supports a second fsl i2c bus, define 1684 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1685 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1686 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1687 second bus. 1688 1689 - drivers/i2c/tegra_i2c.c: 1690 - activate this driver with CONFIG_SYS_I2C_TEGRA 1691 - This driver adds 4 i2c buses with a fix speed from 1692 100000 and the slave addr 0! 1693 1694 - drivers/i2c/ppc4xx_i2c.c 1695 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1696 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1697 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1698 1699 - drivers/i2c/i2c_mxc.c 1700 - activate this driver with CONFIG_SYS_I2C_MXC 1701 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1702 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1703 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1704 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1705 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1706 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1707 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1708 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1709 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1710 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1711 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1712 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1713 If those defines are not set, default value is 100000 1714 for speed, and 0 for slave. 1715 1716 - drivers/i2c/rcar_i2c.c: 1717 - activate this driver with CONFIG_SYS_I2C_RCAR 1718 - This driver adds 4 i2c buses 1719 1720 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1721 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1722 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1723 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1724 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1725 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1726 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1727 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1728 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1729 1730 - drivers/i2c/sh_i2c.c: 1731 - activate this driver with CONFIG_SYS_I2C_SH 1732 - This driver adds from 2 to 5 i2c buses 1733 1734 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1735 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1736 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1737 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1738 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1739 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1740 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1741 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1742 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1743 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1744 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1745 1746 - drivers/i2c/omap24xx_i2c.c 1747 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1748 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1749 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1750 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1751 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1752 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1753 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1754 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1755 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1756 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1757 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1758 1759 - drivers/i2c/zynq_i2c.c 1760 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1761 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1762 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1763 1764 - drivers/i2c/s3c24x0_i2c.c: 1765 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1766 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1767 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1768 with a fix speed from 100000 and the slave addr 0! 1769 1770 - drivers/i2c/ihs_i2c.c 1771 - activate this driver with CONFIG_SYS_I2C_IHS 1772 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1773 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1774 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1775 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1776 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1777 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1778 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1779 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1780 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1781 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1782 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1783 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1784 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1785 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1786 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1787 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1788 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1789 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1790 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1791 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1792 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1793 1794 additional defines: 1795 1796 CONFIG_SYS_NUM_I2C_BUSES 1797 Hold the number of i2c buses you want to use. 1798 1799 CONFIG_SYS_I2C_DIRECT_BUS 1800 define this, if you don't use i2c muxes on your hardware. 1801 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1802 omit this define. 1803 1804 CONFIG_SYS_I2C_MAX_HOPS 1805 define how many muxes are maximal consecutively connected 1806 on one i2c bus. If you not use i2c muxes, omit this 1807 define. 1808 1809 CONFIG_SYS_I2C_BUSES 1810 hold a list of buses you want to use, only used if 1811 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1812 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1813 CONFIG_SYS_NUM_I2C_BUSES = 9: 1814 1815 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1816 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1817 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1818 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1819 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1820 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1821 {1, {I2C_NULL_HOP}}, \ 1822 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1823 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1824 } 1825 1826 which defines 1827 bus 0 on adapter 0 without a mux 1828 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1829 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1830 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1831 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1832 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1833 bus 6 on adapter 1 without a mux 1834 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1835 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1836 1837 If you do not have i2c muxes on your board, omit this define. 1838 1839- Legacy I2C Support: 1840 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1841 then the following macros need to be defined (examples are 1842 from include/configs/lwmon.h): 1843 1844 I2C_INIT 1845 1846 (Optional). Any commands necessary to enable the I2C 1847 controller or configure ports. 1848 1849 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1850 1851 I2C_ACTIVE 1852 1853 The code necessary to make the I2C data line active 1854 (driven). If the data line is open collector, this 1855 define can be null. 1856 1857 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1858 1859 I2C_TRISTATE 1860 1861 The code necessary to make the I2C data line tri-stated 1862 (inactive). If the data line is open collector, this 1863 define can be null. 1864 1865 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1866 1867 I2C_READ 1868 1869 Code that returns true if the I2C data line is high, 1870 false if it is low. 1871 1872 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1873 1874 I2C_SDA(bit) 1875 1876 If <bit> is true, sets the I2C data line high. If it 1877 is false, it clears it (low). 1878 1879 eg: #define I2C_SDA(bit) \ 1880 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1881 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1882 1883 I2C_SCL(bit) 1884 1885 If <bit> is true, sets the I2C clock line high. If it 1886 is false, it clears it (low). 1887 1888 eg: #define I2C_SCL(bit) \ 1889 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1890 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1891 1892 I2C_DELAY 1893 1894 This delay is invoked four times per clock cycle so this 1895 controls the rate of data transfer. The data rate thus 1896 is 1 / (I2C_DELAY * 4). Often defined to be something 1897 like: 1898 1899 #define I2C_DELAY udelay(2) 1900 1901 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1902 1903 If your arch supports the generic GPIO framework (asm/gpio.h), 1904 then you may alternatively define the two GPIOs that are to be 1905 used as SCL / SDA. Any of the previous I2C_xxx macros will 1906 have GPIO-based defaults assigned to them as appropriate. 1907 1908 You should define these to the GPIO value as given directly to 1909 the generic GPIO functions. 1910 1911 CONFIG_SYS_I2C_INIT_BOARD 1912 1913 When a board is reset during an i2c bus transfer 1914 chips might think that the current transfer is still 1915 in progress. On some boards it is possible to access 1916 the i2c SCLK line directly, either by using the 1917 processor pin as a GPIO or by having a second pin 1918 connected to the bus. If this option is defined a 1919 custom i2c_init_board() routine in boards/xxx/board.c 1920 is run early in the boot sequence. 1921 1922 CONFIG_I2C_MULTI_BUS 1923 1924 This option allows the use of multiple I2C buses, each of which 1925 must have a controller. At any point in time, only one bus is 1926 active. To switch to a different bus, use the 'i2c dev' command. 1927 Note that bus numbering is zero-based. 1928 1929 CONFIG_SYS_I2C_NOPROBES 1930 1931 This option specifies a list of I2C devices that will be skipped 1932 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1933 is set, specify a list of bus-device pairs. Otherwise, specify 1934 a 1D array of device addresses 1935 1936 e.g. 1937 #undef CONFIG_I2C_MULTI_BUS 1938 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1939 1940 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1941 1942 #define CONFIG_I2C_MULTI_BUS 1943 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1944 1945 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1946 1947 CONFIG_SYS_SPD_BUS_NUM 1948 1949 If defined, then this indicates the I2C bus number for DDR SPD. 1950 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1951 1952 CONFIG_SYS_RTC_BUS_NUM 1953 1954 If defined, then this indicates the I2C bus number for the RTC. 1955 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1956 1957 CONFIG_SOFT_I2C_READ_REPEATED_START 1958 1959 defining this will force the i2c_read() function in 1960 the soft_i2c driver to perform an I2C repeated start 1961 between writing the address pointer and reading the 1962 data. If this define is omitted the default behaviour 1963 of doing a stop-start sequence will be used. Most I2C 1964 devices can use either method, but some require one or 1965 the other. 1966 1967- SPI Support: CONFIG_SPI 1968 1969 Enables SPI driver (so far only tested with 1970 SPI EEPROM, also an instance works with Crystal A/D and 1971 D/As on the SACSng board) 1972 1973 CONFIG_SOFT_SPI 1974 1975 Enables a software (bit-bang) SPI driver rather than 1976 using hardware support. This is a general purpose 1977 driver that only requires three general I/O port pins 1978 (two outputs, one input) to function. If this is 1979 defined, the board configuration must define several 1980 SPI configuration items (port pins to use, etc). For 1981 an example, see include/configs/sacsng.h. 1982 1983 CONFIG_HARD_SPI 1984 1985 Enables a hardware SPI driver for general-purpose reads 1986 and writes. As with CONFIG_SOFT_SPI, the board configuration 1987 must define a list of chip-select function pointers. 1988 Currently supported on some MPC8xxx processors. For an 1989 example, see include/configs/mpc8349emds.h. 1990 1991 CONFIG_SYS_SPI_MXC_WAIT 1992 Timeout for waiting until spi transfer completed. 1993 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1994 1995- FPGA Support: CONFIG_FPGA 1996 1997 Enables FPGA subsystem. 1998 1999 CONFIG_FPGA_<vendor> 2000 2001 Enables support for specific chip vendors. 2002 (ALTERA, XILINX) 2003 2004 CONFIG_FPGA_<family> 2005 2006 Enables support for FPGA family. 2007 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2008 2009 CONFIG_FPGA_COUNT 2010 2011 Specify the number of FPGA devices to support. 2012 2013 CONFIG_SYS_FPGA_PROG_FEEDBACK 2014 2015 Enable printing of hash marks during FPGA configuration. 2016 2017 CONFIG_SYS_FPGA_CHECK_BUSY 2018 2019 Enable checks on FPGA configuration interface busy 2020 status by the configuration function. This option 2021 will require a board or device specific function to 2022 be written. 2023 2024 CONFIG_FPGA_DELAY 2025 2026 If defined, a function that provides delays in the FPGA 2027 configuration driver. 2028 2029 CONFIG_SYS_FPGA_CHECK_CTRLC 2030 Allow Control-C to interrupt FPGA configuration 2031 2032 CONFIG_SYS_FPGA_CHECK_ERROR 2033 2034 Check for configuration errors during FPGA bitfile 2035 loading. For example, abort during Virtex II 2036 configuration if the INIT_B line goes low (which 2037 indicated a CRC error). 2038 2039 CONFIG_SYS_FPGA_WAIT_INIT 2040 2041 Maximum time to wait for the INIT_B line to de-assert 2042 after PROB_B has been de-asserted during a Virtex II 2043 FPGA configuration sequence. The default time is 500 2044 ms. 2045 2046 CONFIG_SYS_FPGA_WAIT_BUSY 2047 2048 Maximum time to wait for BUSY to de-assert during 2049 Virtex II FPGA configuration. The default is 5 ms. 2050 2051 CONFIG_SYS_FPGA_WAIT_CONFIG 2052 2053 Time to wait after FPGA configuration. The default is 2054 200 ms. 2055 2056- Configuration Management: 2057 CONFIG_BUILD_TARGET 2058 2059 Some SoCs need special image types (e.g. U-Boot binary 2060 with a special header) as build targets. By defining 2061 CONFIG_BUILD_TARGET in the SoC / board header, this 2062 special image will be automatically built upon calling 2063 make / buildman. 2064 2065 CONFIG_IDENT_STRING 2066 2067 If defined, this string will be added to the U-Boot 2068 version information (U_BOOT_VERSION) 2069 2070- Vendor Parameter Protection: 2071 2072 U-Boot considers the values of the environment 2073 variables "serial#" (Board Serial Number) and 2074 "ethaddr" (Ethernet Address) to be parameters that 2075 are set once by the board vendor / manufacturer, and 2076 protects these variables from casual modification by 2077 the user. Once set, these variables are read-only, 2078 and write or delete attempts are rejected. You can 2079 change this behaviour: 2080 2081 If CONFIG_ENV_OVERWRITE is #defined in your config 2082 file, the write protection for vendor parameters is 2083 completely disabled. Anybody can change or delete 2084 these parameters. 2085 2086 Alternatively, if you define _both_ an ethaddr in the 2087 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2088 Ethernet address is installed in the environment, 2089 which can be changed exactly ONCE by the user. [The 2090 serial# is unaffected by this, i. e. it remains 2091 read-only.] 2092 2093 The same can be accomplished in a more flexible way 2094 for any variable by configuring the type of access 2095 to allow for those variables in the ".flags" variable 2096 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2097 2098- Protected RAM: 2099 CONFIG_PRAM 2100 2101 Define this variable to enable the reservation of 2102 "protected RAM", i. e. RAM which is not overwritten 2103 by U-Boot. Define CONFIG_PRAM to hold the number of 2104 kB you want to reserve for pRAM. You can overwrite 2105 this default value by defining an environment 2106 variable "pram" to the number of kB you want to 2107 reserve. Note that the board info structure will 2108 still show the full amount of RAM. If pRAM is 2109 reserved, a new environment variable "mem" will 2110 automatically be defined to hold the amount of 2111 remaining RAM in a form that can be passed as boot 2112 argument to Linux, for instance like that: 2113 2114 setenv bootargs ... mem=\${mem} 2115 saveenv 2116 2117 This way you can tell Linux not to use this memory, 2118 either, which results in a memory region that will 2119 not be affected by reboots. 2120 2121 *WARNING* If your board configuration uses automatic 2122 detection of the RAM size, you must make sure that 2123 this memory test is non-destructive. So far, the 2124 following board configurations are known to be 2125 "pRAM-clean": 2126 2127 IVMS8, IVML24, SPD8xx, 2128 HERMES, IP860, RPXlite, LWMON, 2129 FLAGADM 2130 2131- Access to physical memory region (> 4GB) 2132 Some basic support is provided for operations on memory not 2133 normally accessible to U-Boot - e.g. some architectures 2134 support access to more than 4GB of memory on 32-bit 2135 machines using physical address extension or similar. 2136 Define CONFIG_PHYSMEM to access this basic support, which 2137 currently only supports clearing the memory. 2138 2139- Error Recovery: 2140 CONFIG_NET_RETRY_COUNT 2141 2142 This variable defines the number of retries for 2143 network operations like ARP, RARP, TFTP, or BOOTP 2144 before giving up the operation. If not defined, a 2145 default value of 5 is used. 2146 2147 CONFIG_ARP_TIMEOUT 2148 2149 Timeout waiting for an ARP reply in milliseconds. 2150 2151 CONFIG_NFS_TIMEOUT 2152 2153 Timeout in milliseconds used in NFS protocol. 2154 If you encounter "ERROR: Cannot umount" in nfs command, 2155 try longer timeout such as 2156 #define CONFIG_NFS_TIMEOUT 10000UL 2157 2158- Command Interpreter: 2159 CONFIG_SYS_PROMPT_HUSH_PS2 2160 2161 This defines the secondary prompt string, which is 2162 printed when the command interpreter needs more input 2163 to complete a command. Usually "> ". 2164 2165 Note: 2166 2167 In the current implementation, the local variables 2168 space and global environment variables space are 2169 separated. Local variables are those you define by 2170 simply typing `name=value'. To access a local 2171 variable later on, you have write `$name' or 2172 `${name}'; to execute the contents of a variable 2173 directly type `$name' at the command prompt. 2174 2175 Global environment variables are those you use 2176 setenv/printenv to work with. To run a command stored 2177 in such a variable, you need to use the run command, 2178 and you must not use the '$' sign to access them. 2179 2180 To store commands and special characters in a 2181 variable, please use double quotation marks 2182 surrounding the whole text of the variable, instead 2183 of the backslashes before semicolons and special 2184 symbols. 2185 2186- Command Line Editing and History: 2187 CONFIG_CMDLINE_PS_SUPPORT 2188 2189 Enable support for changing the command prompt string 2190 at run-time. Only static string is supported so far. 2191 The string is obtained from environment variables PS1 2192 and PS2. 2193 2194- Default Environment: 2195 CONFIG_EXTRA_ENV_SETTINGS 2196 2197 Define this to contain any number of null terminated 2198 strings (variable = value pairs) that will be part of 2199 the default environment compiled into the boot image. 2200 2201 For example, place something like this in your 2202 board's config file: 2203 2204 #define CONFIG_EXTRA_ENV_SETTINGS \ 2205 "myvar1=value1\0" \ 2206 "myvar2=value2\0" 2207 2208 Warning: This method is based on knowledge about the 2209 internal format how the environment is stored by the 2210 U-Boot code. This is NOT an official, exported 2211 interface! Although it is unlikely that this format 2212 will change soon, there is no guarantee either. 2213 You better know what you are doing here. 2214 2215 Note: overly (ab)use of the default environment is 2216 discouraged. Make sure to check other ways to preset 2217 the environment like the "source" command or the 2218 boot command first. 2219 2220 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2221 2222 Define this in order to add variables describing certain 2223 run-time determined information about the hardware to the 2224 environment. These will be named board_name, board_rev. 2225 2226 CONFIG_DELAY_ENVIRONMENT 2227 2228 Normally the environment is loaded when the board is 2229 initialised so that it is available to U-Boot. This inhibits 2230 that so that the environment is not available until 2231 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2232 this is instead controlled by the value of 2233 /config/load-environment. 2234 2235- Serial Flash support 2236 Usage requires an initial 'sf probe' to define the serial 2237 flash parameters, followed by read/write/erase/update 2238 commands. 2239 2240 The following defaults may be provided by the platform 2241 to handle the common case when only a single serial 2242 flash is present on the system. 2243 2244 CONFIG_SF_DEFAULT_BUS Bus identifier 2245 CONFIG_SF_DEFAULT_CS Chip-select 2246 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2247 CONFIG_SF_DEFAULT_SPEED in Hz 2248 2249 2250- TFTP Fixed UDP Port: 2251 CONFIG_TFTP_PORT 2252 2253 If this is defined, the environment variable tftpsrcp 2254 is used to supply the TFTP UDP source port value. 2255 If tftpsrcp isn't defined, the normal pseudo-random port 2256 number generator is used. 2257 2258 Also, the environment variable tftpdstp is used to supply 2259 the TFTP UDP destination port value. If tftpdstp isn't 2260 defined, the normal port 69 is used. 2261 2262 The purpose for tftpsrcp is to allow a TFTP server to 2263 blindly start the TFTP transfer using the pre-configured 2264 target IP address and UDP port. This has the effect of 2265 "punching through" the (Windows XP) firewall, allowing 2266 the remainder of the TFTP transfer to proceed normally. 2267 A better solution is to properly configure the firewall, 2268 but sometimes that is not allowed. 2269 2270- Show boot progress: 2271 CONFIG_SHOW_BOOT_PROGRESS 2272 2273 Defining this option allows to add some board- 2274 specific code (calling a user-provided function 2275 "show_boot_progress(int)") that enables you to show 2276 the system's boot progress on some display (for 2277 example, some LED's) on your board. At the moment, 2278 the following checkpoints are implemented: 2279 2280 2281Legacy uImage format: 2282 2283 Arg Where When 2284 1 common/cmd_bootm.c before attempting to boot an image 2285 -1 common/cmd_bootm.c Image header has bad magic number 2286 2 common/cmd_bootm.c Image header has correct magic number 2287 -2 common/cmd_bootm.c Image header has bad checksum 2288 3 common/cmd_bootm.c Image header has correct checksum 2289 -3 common/cmd_bootm.c Image data has bad checksum 2290 4 common/cmd_bootm.c Image data has correct checksum 2291 -4 common/cmd_bootm.c Image is for unsupported architecture 2292 5 common/cmd_bootm.c Architecture check OK 2293 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2294 6 common/cmd_bootm.c Image Type check OK 2295 -6 common/cmd_bootm.c gunzip uncompression error 2296 -7 common/cmd_bootm.c Unimplemented compression type 2297 7 common/cmd_bootm.c Uncompression OK 2298 8 common/cmd_bootm.c No uncompress/copy overwrite error 2299 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2300 2301 9 common/image.c Start initial ramdisk verification 2302 -10 common/image.c Ramdisk header has bad magic number 2303 -11 common/image.c Ramdisk header has bad checksum 2304 10 common/image.c Ramdisk header is OK 2305 -12 common/image.c Ramdisk data has bad checksum 2306 11 common/image.c Ramdisk data has correct checksum 2307 12 common/image.c Ramdisk verification complete, start loading 2308 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2309 13 common/image.c Start multifile image verification 2310 14 common/image.c No initial ramdisk, no multifile, continue. 2311 2312 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2313 2314 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2315 -31 post/post.c POST test failed, detected by post_output_backlog() 2316 -32 post/post.c POST test failed, detected by post_run_single() 2317 2318 34 common/cmd_doc.c before loading a Image from a DOC device 2319 -35 common/cmd_doc.c Bad usage of "doc" command 2320 35 common/cmd_doc.c correct usage of "doc" command 2321 -36 common/cmd_doc.c No boot device 2322 36 common/cmd_doc.c correct boot device 2323 -37 common/cmd_doc.c Unknown Chip ID on boot device 2324 37 common/cmd_doc.c correct chip ID found, device available 2325 -38 common/cmd_doc.c Read Error on boot device 2326 38 common/cmd_doc.c reading Image header from DOC device OK 2327 -39 common/cmd_doc.c Image header has bad magic number 2328 39 common/cmd_doc.c Image header has correct magic number 2329 -40 common/cmd_doc.c Error reading Image from DOC device 2330 40 common/cmd_doc.c Image header has correct magic number 2331 41 common/cmd_ide.c before loading a Image from a IDE device 2332 -42 common/cmd_ide.c Bad usage of "ide" command 2333 42 common/cmd_ide.c correct usage of "ide" command 2334 -43 common/cmd_ide.c No boot device 2335 43 common/cmd_ide.c boot device found 2336 -44 common/cmd_ide.c Device not available 2337 44 common/cmd_ide.c Device available 2338 -45 common/cmd_ide.c wrong partition selected 2339 45 common/cmd_ide.c partition selected 2340 -46 common/cmd_ide.c Unknown partition table 2341 46 common/cmd_ide.c valid partition table found 2342 -47 common/cmd_ide.c Invalid partition type 2343 47 common/cmd_ide.c correct partition type 2344 -48 common/cmd_ide.c Error reading Image Header on boot device 2345 48 common/cmd_ide.c reading Image Header from IDE device OK 2346 -49 common/cmd_ide.c Image header has bad magic number 2347 49 common/cmd_ide.c Image header has correct magic number 2348 -50 common/cmd_ide.c Image header has bad checksum 2349 50 common/cmd_ide.c Image header has correct checksum 2350 -51 common/cmd_ide.c Error reading Image from IDE device 2351 51 common/cmd_ide.c reading Image from IDE device OK 2352 52 common/cmd_nand.c before loading a Image from a NAND device 2353 -53 common/cmd_nand.c Bad usage of "nand" command 2354 53 common/cmd_nand.c correct usage of "nand" command 2355 -54 common/cmd_nand.c No boot device 2356 54 common/cmd_nand.c boot device found 2357 -55 common/cmd_nand.c Unknown Chip ID on boot device 2358 55 common/cmd_nand.c correct chip ID found, device available 2359 -56 common/cmd_nand.c Error reading Image Header on boot device 2360 56 common/cmd_nand.c reading Image Header from NAND device OK 2361 -57 common/cmd_nand.c Image header has bad magic number 2362 57 common/cmd_nand.c Image header has correct magic number 2363 -58 common/cmd_nand.c Error reading Image from NAND device 2364 58 common/cmd_nand.c reading Image from NAND device OK 2365 2366 -60 common/env_common.c Environment has a bad CRC, using default 2367 2368 64 net/eth.c starting with Ethernet configuration. 2369 -64 net/eth.c no Ethernet found. 2370 65 net/eth.c Ethernet found. 2371 2372 -80 common/cmd_net.c usage wrong 2373 80 common/cmd_net.c before calling net_loop() 2374 -81 common/cmd_net.c some error in net_loop() occurred 2375 81 common/cmd_net.c net_loop() back without error 2376 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2377 82 common/cmd_net.c trying automatic boot 2378 83 common/cmd_net.c running "source" command 2379 -83 common/cmd_net.c some error in automatic boot or "source" command 2380 84 common/cmd_net.c end without errors 2381 2382FIT uImage format: 2383 2384 Arg Where When 2385 100 common/cmd_bootm.c Kernel FIT Image has correct format 2386 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2387 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2388 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2389 102 common/cmd_bootm.c Kernel unit name specified 2390 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2391 103 common/cmd_bootm.c Found configuration node 2392 104 common/cmd_bootm.c Got kernel subimage node offset 2393 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2394 105 common/cmd_bootm.c Kernel subimage hash verification OK 2395 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2396 106 common/cmd_bootm.c Architecture check OK 2397 -106 common/cmd_bootm.c Kernel subimage has wrong type 2398 107 common/cmd_bootm.c Kernel subimage type OK 2399 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2400 108 common/cmd_bootm.c Got kernel subimage data/size 2401 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2402 -109 common/cmd_bootm.c Can't get kernel subimage type 2403 -110 common/cmd_bootm.c Can't get kernel subimage comp 2404 -111 common/cmd_bootm.c Can't get kernel subimage os 2405 -112 common/cmd_bootm.c Can't get kernel subimage load address 2406 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2407 2408 120 common/image.c Start initial ramdisk verification 2409 -120 common/image.c Ramdisk FIT image has incorrect format 2410 121 common/image.c Ramdisk FIT image has correct format 2411 122 common/image.c No ramdisk subimage unit name, using configuration 2412 -122 common/image.c Can't get configuration for ramdisk subimage 2413 123 common/image.c Ramdisk unit name specified 2414 -124 common/image.c Can't get ramdisk subimage node offset 2415 125 common/image.c Got ramdisk subimage node offset 2416 -125 common/image.c Ramdisk subimage hash verification failed 2417 126 common/image.c Ramdisk subimage hash verification OK 2418 -126 common/image.c Ramdisk subimage for unsupported architecture 2419 127 common/image.c Architecture check OK 2420 -127 common/image.c Can't get ramdisk subimage data/size 2421 128 common/image.c Got ramdisk subimage data/size 2422 129 common/image.c Can't get ramdisk load address 2423 -129 common/image.c Got ramdisk load address 2424 2425 -130 common/cmd_doc.c Incorrect FIT image format 2426 131 common/cmd_doc.c FIT image format OK 2427 2428 -140 common/cmd_ide.c Incorrect FIT image format 2429 141 common/cmd_ide.c FIT image format OK 2430 2431 -150 common/cmd_nand.c Incorrect FIT image format 2432 151 common/cmd_nand.c FIT image format OK 2433 2434- legacy image format: 2435 CONFIG_IMAGE_FORMAT_LEGACY 2436 enables the legacy image format support in U-Boot. 2437 2438 Default: 2439 enabled if CONFIG_FIT_SIGNATURE is not defined. 2440 2441 CONFIG_DISABLE_IMAGE_LEGACY 2442 disable the legacy image format 2443 2444 This define is introduced, as the legacy image format is 2445 enabled per default for backward compatibility. 2446 2447- Standalone program support: 2448 CONFIG_STANDALONE_LOAD_ADDR 2449 2450 This option defines a board specific value for the 2451 address where standalone program gets loaded, thus 2452 overwriting the architecture dependent default 2453 settings. 2454 2455- Frame Buffer Address: 2456 CONFIG_FB_ADDR 2457 2458 Define CONFIG_FB_ADDR if you want to use specific 2459 address for frame buffer. This is typically the case 2460 when using a graphics controller has separate video 2461 memory. U-Boot will then place the frame buffer at 2462 the given address instead of dynamically reserving it 2463 in system RAM by calling lcd_setmem(), which grabs 2464 the memory for the frame buffer depending on the 2465 configured panel size. 2466 2467 Please see board_init_f function. 2468 2469- Automatic software updates via TFTP server 2470 CONFIG_UPDATE_TFTP 2471 CONFIG_UPDATE_TFTP_CNT_MAX 2472 CONFIG_UPDATE_TFTP_MSEC_MAX 2473 2474 These options enable and control the auto-update feature; 2475 for a more detailed description refer to doc/README.update. 2476 2477- MTD Support (mtdparts command, UBI support) 2478 CONFIG_MTD_DEVICE 2479 2480 Adds the MTD device infrastructure from the Linux kernel. 2481 Needed for mtdparts command support. 2482 2483 CONFIG_MTD_PARTITIONS 2484 2485 Adds the MTD partitioning infrastructure from the Linux 2486 kernel. Needed for UBI support. 2487 2488- UBI support 2489 CONFIG_UBI_SILENCE_MSG 2490 2491 Make the verbose messages from UBI stop printing. This leaves 2492 warnings and errors enabled. 2493 2494 2495 CONFIG_MTD_UBI_WL_THRESHOLD 2496 This parameter defines the maximum difference between the highest 2497 erase counter value and the lowest erase counter value of eraseblocks 2498 of UBI devices. When this threshold is exceeded, UBI starts performing 2499 wear leveling by means of moving data from eraseblock with low erase 2500 counter to eraseblocks with high erase counter. 2501 2502 The default value should be OK for SLC NAND flashes, NOR flashes and 2503 other flashes which have eraseblock life-cycle 100000 or more. 2504 However, in case of MLC NAND flashes which typically have eraseblock 2505 life-cycle less than 10000, the threshold should be lessened (e.g., 2506 to 128 or 256, although it does not have to be power of 2). 2507 2508 default: 4096 2509 2510 CONFIG_MTD_UBI_BEB_LIMIT 2511 This option specifies the maximum bad physical eraseblocks UBI 2512 expects on the MTD device (per 1024 eraseblocks). If the 2513 underlying flash does not admit of bad eraseblocks (e.g. NOR 2514 flash), this value is ignored. 2515 2516 NAND datasheets often specify the minimum and maximum NVM 2517 (Number of Valid Blocks) for the flashes' endurance lifetime. 2518 The maximum expected bad eraseblocks per 1024 eraseblocks 2519 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2520 which gives 20 for most NANDs (MaxNVB is basically the total 2521 count of eraseblocks on the chip). 2522 2523 To put it differently, if this value is 20, UBI will try to 2524 reserve about 1.9% of physical eraseblocks for bad blocks 2525 handling. And that will be 1.9% of eraseblocks on the entire 2526 NAND chip, not just the MTD partition UBI attaches. This means 2527 that if you have, say, a NAND flash chip admits maximum 40 bad 2528 eraseblocks, and it is split on two MTD partitions of the same 2529 size, UBI will reserve 40 eraseblocks when attaching a 2530 partition. 2531 2532 default: 20 2533 2534 CONFIG_MTD_UBI_FASTMAP 2535 Fastmap is a mechanism which allows attaching an UBI device 2536 in nearly constant time. Instead of scanning the whole MTD device it 2537 only has to locate a checkpoint (called fastmap) on the device. 2538 The on-flash fastmap contains all information needed to attach 2539 the device. Using fastmap makes only sense on large devices where 2540 attaching by scanning takes long. UBI will not automatically install 2541 a fastmap on old images, but you can set the UBI parameter 2542 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2543 that fastmap-enabled images are still usable with UBI implementations 2544 without fastmap support. On typical flash devices the whole fastmap 2545 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2546 2547 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2548 Set this parameter to enable fastmap automatically on images 2549 without a fastmap. 2550 default: 0 2551 2552 CONFIG_MTD_UBI_FM_DEBUG 2553 Enable UBI fastmap debug 2554 default: 0 2555 2556- UBIFS support 2557 CONFIG_UBIFS_SILENCE_MSG 2558 2559 Make the verbose messages from UBIFS stop printing. This leaves 2560 warnings and errors enabled. 2561 2562- SPL framework 2563 CONFIG_SPL 2564 Enable building of SPL globally. 2565 2566 CONFIG_SPL_LDSCRIPT 2567 LDSCRIPT for linking the SPL binary. 2568 2569 CONFIG_SPL_MAX_FOOTPRINT 2570 Maximum size in memory allocated to the SPL, BSS included. 2571 When defined, the linker checks that the actual memory 2572 used by SPL from _start to __bss_end does not exceed it. 2573 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2574 must not be both defined at the same time. 2575 2576 CONFIG_SPL_MAX_SIZE 2577 Maximum size of the SPL image (text, data, rodata, and 2578 linker lists sections), BSS excluded. 2579 When defined, the linker checks that the actual size does 2580 not exceed it. 2581 2582 CONFIG_SPL_TEXT_BASE 2583 TEXT_BASE for linking the SPL binary. 2584 2585 CONFIG_SPL_RELOC_TEXT_BASE 2586 Address to relocate to. If unspecified, this is equal to 2587 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2588 2589 CONFIG_SPL_BSS_START_ADDR 2590 Link address for the BSS within the SPL binary. 2591 2592 CONFIG_SPL_BSS_MAX_SIZE 2593 Maximum size in memory allocated to the SPL BSS. 2594 When defined, the linker checks that the actual memory used 2595 by SPL from __bss_start to __bss_end does not exceed it. 2596 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2597 must not be both defined at the same time. 2598 2599 CONFIG_SPL_STACK 2600 Adress of the start of the stack SPL will use 2601 2602 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2603 When defined, SPL will panic() if the image it has 2604 loaded does not have a signature. 2605 Defining this is useful when code which loads images 2606 in SPL cannot guarantee that absolutely all read errors 2607 will be caught. 2608 An example is the LPC32XX MLC NAND driver, which will 2609 consider that a completely unreadable NAND block is bad, 2610 and thus should be skipped silently. 2611 2612 CONFIG_SPL_RELOC_STACK 2613 Adress of the start of the stack SPL will use after 2614 relocation. If unspecified, this is equal to 2615 CONFIG_SPL_STACK. 2616 2617 CONFIG_SYS_SPL_MALLOC_START 2618 Starting address of the malloc pool used in SPL. 2619 When this option is set the full malloc is used in SPL and 2620 it is set up by spl_init() and before that, the simple malloc() 2621 can be used if CONFIG_SYS_MALLOC_F is defined. 2622 2623 CONFIG_SYS_SPL_MALLOC_SIZE 2624 The size of the malloc pool used in SPL. 2625 2626 CONFIG_SPL_OS_BOOT 2627 Enable booting directly to an OS from SPL. 2628 See also: doc/README.falcon 2629 2630 CONFIG_SPL_DISPLAY_PRINT 2631 For ARM, enable an optional function to print more information 2632 about the running system. 2633 2634 CONFIG_SPL_INIT_MINIMAL 2635 Arch init code should be built for a very small image 2636 2637 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2638 Partition on the MMC to load U-Boot from when the MMC is being 2639 used in raw mode 2640 2641 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2642 Sector to load kernel uImage from when MMC is being 2643 used in raw mode (for Falcon mode) 2644 2645 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2646 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2647 Sector and number of sectors to load kernel argument 2648 parameters from when MMC is being used in raw mode 2649 (for falcon mode) 2650 2651 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2652 Partition on the MMC to load U-Boot from when the MMC is being 2653 used in fs mode 2654 2655 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2656 Filename to read to load U-Boot when reading from filesystem 2657 2658 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2659 Filename to read to load kernel uImage when reading 2660 from filesystem (for Falcon mode) 2661 2662 CONFIG_SPL_FS_LOAD_ARGS_NAME 2663 Filename to read to load kernel argument parameters 2664 when reading from filesystem (for Falcon mode) 2665 2666 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2667 Set this for NAND SPL on PPC mpc83xx targets, so that 2668 start.S waits for the rest of the SPL to load before 2669 continuing (the hardware starts execution after just 2670 loading the first page rather than the full 4K). 2671 2672 CONFIG_SPL_SKIP_RELOCATE 2673 Avoid SPL relocation 2674 2675 CONFIG_SPL_NAND_BASE 2676 Include nand_base.c in the SPL. Requires 2677 CONFIG_SPL_NAND_DRIVERS. 2678 2679 CONFIG_SPL_NAND_DRIVERS 2680 SPL uses normal NAND drivers, not minimal drivers. 2681 2682 CONFIG_SPL_NAND_ECC 2683 Include standard software ECC in the SPL 2684 2685 CONFIG_SPL_NAND_SIMPLE 2686 Support for NAND boot using simple NAND drivers that 2687 expose the cmd_ctrl() interface. 2688 2689 CONFIG_SPL_UBI 2690 Support for a lightweight UBI (fastmap) scanner and 2691 loader 2692 2693 CONFIG_SPL_NAND_RAW_ONLY 2694 Support to boot only raw u-boot.bin images. Use this only 2695 if you need to save space. 2696 2697 CONFIG_SPL_COMMON_INIT_DDR 2698 Set for common ddr init with serial presence detect in 2699 SPL binary. 2700 2701 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2702 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2703 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2704 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2705 CONFIG_SYS_NAND_ECCBYTES 2706 Defines the size and behavior of the NAND that SPL uses 2707 to read U-Boot 2708 2709 CONFIG_SPL_NAND_BOOT 2710 Add support NAND boot 2711 2712 CONFIG_SYS_NAND_U_BOOT_OFFS 2713 Location in NAND to read U-Boot from 2714 2715 CONFIG_SYS_NAND_U_BOOT_DST 2716 Location in memory to load U-Boot to 2717 2718 CONFIG_SYS_NAND_U_BOOT_SIZE 2719 Size of image to load 2720 2721 CONFIG_SYS_NAND_U_BOOT_START 2722 Entry point in loaded image to jump to 2723 2724 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2725 Define this if you need to first read the OOB and then the 2726 data. This is used, for example, on davinci platforms. 2727 2728 CONFIG_SPL_RAM_DEVICE 2729 Support for running image already present in ram, in SPL binary 2730 2731 CONFIG_SPL_PAD_TO 2732 Image offset to which the SPL should be padded before appending 2733 the SPL payload. By default, this is defined as 2734 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2735 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2736 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2737 2738 CONFIG_SPL_TARGET 2739 Final target image containing SPL and payload. Some SPLs 2740 use an arch-specific makefile fragment instead, for 2741 example if more than one image needs to be produced. 2742 2743 CONFIG_FIT_SPL_PRINT 2744 Printing information about a FIT image adds quite a bit of 2745 code to SPL. So this is normally disabled in SPL. Use this 2746 option to re-enable it. This will affect the output of the 2747 bootm command when booting a FIT image. 2748 2749- TPL framework 2750 CONFIG_TPL 2751 Enable building of TPL globally. 2752 2753 CONFIG_TPL_PAD_TO 2754 Image offset to which the TPL should be padded before appending 2755 the TPL payload. By default, this is defined as 2756 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2757 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2758 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2759 2760- Interrupt support (PPC): 2761 2762 There are common interrupt_init() and timer_interrupt() 2763 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2764 for CPU specific initialization. interrupt_init_cpu() 2765 should set decrementer_count to appropriate value. If 2766 CPU resets decrementer automatically after interrupt 2767 (ppc4xx) it should set decrementer_count to zero. 2768 timer_interrupt() calls timer_interrupt_cpu() for CPU 2769 specific handling. If board has watchdog / status_led 2770 / other_activity_monitor it works automatically from 2771 general timer_interrupt(). 2772 2773 2774Board initialization settings: 2775------------------------------ 2776 2777During Initialization u-boot calls a number of board specific functions 2778to allow the preparation of board specific prerequisites, e.g. pin setup 2779before drivers are initialized. To enable these callbacks the 2780following configuration macros have to be defined. Currently this is 2781architecture specific, so please check arch/your_architecture/lib/board.c 2782typically in board_init_f() and board_init_r(). 2783 2784- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2785- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2786- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2787- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2788 2789Configuration Settings: 2790----------------------- 2791 2792- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2793 Optionally it can be defined to support 64-bit memory commands. 2794 2795- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2796 undefine this when you're short of memory. 2797 2798- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2799 width of the commands listed in the 'help' command output. 2800 2801- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2802 prompt for user input. 2803 2804- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2805 2806- CONFIG_SYS_PBSIZE: Buffer size for Console output 2807 2808- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2809 2810- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2811 the application (usually a Linux kernel) when it is 2812 booted 2813 2814- CONFIG_SYS_BAUDRATE_TABLE: 2815 List of legal baudrate settings for this board. 2816 2817- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2818 Begin and End addresses of the area used by the 2819 simple memory test. 2820 2821- CONFIG_SYS_ALT_MEMTEST: 2822 Enable an alternate, more extensive memory test. 2823 2824- CONFIG_SYS_MEMTEST_SCRATCH: 2825 Scratch address used by the alternate memory test 2826 You only need to set this if address zero isn't writeable 2827 2828- CONFIG_SYS_MEM_RESERVE_SECURE 2829 Only implemented for ARMv8 for now. 2830 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2831 is substracted from total RAM and won't be reported to OS. 2832 This memory can be used as secure memory. A variable 2833 gd->arch.secure_ram is used to track the location. In systems 2834 the RAM base is not zero, or RAM is divided into banks, 2835 this variable needs to be recalcuated to get the address. 2836 2837- CONFIG_SYS_MEM_TOP_HIDE: 2838 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2839 this specified memory area will get subtracted from the top 2840 (end) of RAM and won't get "touched" at all by U-Boot. By 2841 fixing up gd->ram_size the Linux kernel should gets passed 2842 the now "corrected" memory size and won't touch it either. 2843 This should work for arch/ppc and arch/powerpc. Only Linux 2844 board ports in arch/powerpc with bootwrapper support that 2845 recalculate the memory size from the SDRAM controller setup 2846 will have to get fixed in Linux additionally. 2847 2848 This option can be used as a workaround for the 440EPx/GRx 2849 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2850 be touched. 2851 2852 WARNING: Please make sure that this value is a multiple of 2853 the Linux page size (normally 4k). If this is not the case, 2854 then the end address of the Linux memory will be located at a 2855 non page size aligned address and this could cause major 2856 problems. 2857 2858- CONFIG_SYS_LOADS_BAUD_CHANGE: 2859 Enable temporary baudrate change while serial download 2860 2861- CONFIG_SYS_SDRAM_BASE: 2862 Physical start address of SDRAM. _Must_ be 0 here. 2863 2864- CONFIG_SYS_FLASH_BASE: 2865 Physical start address of Flash memory. 2866 2867- CONFIG_SYS_MONITOR_BASE: 2868 Physical start address of boot monitor code (set by 2869 make config files to be same as the text base address 2870 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2871 CONFIG_SYS_FLASH_BASE when booting from flash. 2872 2873- CONFIG_SYS_MONITOR_LEN: 2874 Size of memory reserved for monitor code, used to 2875 determine _at_compile_time_ (!) if the environment is 2876 embedded within the U-Boot image, or in a separate 2877 flash sector. 2878 2879- CONFIG_SYS_MALLOC_LEN: 2880 Size of DRAM reserved for malloc() use. 2881 2882- CONFIG_SYS_MALLOC_F_LEN 2883 Size of the malloc() pool for use before relocation. If 2884 this is defined, then a very simple malloc() implementation 2885 will become available before relocation. The address is just 2886 below the global data, and the stack is moved down to make 2887 space. 2888 2889 This feature allocates regions with increasing addresses 2890 within the region. calloc() is supported, but realloc() 2891 is not available. free() is supported but does nothing. 2892 The memory will be freed (or in fact just forgotten) when 2893 U-Boot relocates itself. 2894 2895- CONFIG_SYS_MALLOC_SIMPLE 2896 Provides a simple and small malloc() and calloc() for those 2897 boards which do not use the full malloc in SPL (which is 2898 enabled with CONFIG_SYS_SPL_MALLOC_START). 2899 2900- CONFIG_SYS_NONCACHED_MEMORY: 2901 Size of non-cached memory area. This area of memory will be 2902 typically located right below the malloc() area and mapped 2903 uncached in the MMU. This is useful for drivers that would 2904 otherwise require a lot of explicit cache maintenance. For 2905 some drivers it's also impossible to properly maintain the 2906 cache. For example if the regions that need to be flushed 2907 are not a multiple of the cache-line size, *and* padding 2908 cannot be allocated between the regions to align them (i.e. 2909 if the HW requires a contiguous array of regions, and the 2910 size of each region is not cache-aligned), then a flush of 2911 one region may result in overwriting data that hardware has 2912 written to another region in the same cache-line. This can 2913 happen for example in network drivers where descriptors for 2914 buffers are typically smaller than the CPU cache-line (e.g. 2915 16 bytes vs. 32 or 64 bytes). 2916 2917 Non-cached memory is only supported on 32-bit ARM at present. 2918 2919- CONFIG_SYS_BOOTM_LEN: 2920 Normally compressed uImages are limited to an 2921 uncompressed size of 8 MBytes. If this is not enough, 2922 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2923 to adjust this setting to your needs. 2924 2925- CONFIG_SYS_BOOTMAPSZ: 2926 Maximum size of memory mapped by the startup code of 2927 the Linux kernel; all data that must be processed by 2928 the Linux kernel (bd_info, boot arguments, FDT blob if 2929 used) must be put below this limit, unless "bootm_low" 2930 environment variable is defined and non-zero. In such case 2931 all data for the Linux kernel must be between "bootm_low" 2932 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2933 variable "bootm_mapsize" will override the value of 2934 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2935 then the value in "bootm_size" will be used instead. 2936 2937- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2938 Enable initrd_high functionality. If defined then the 2939 initrd_high feature is enabled and the bootm ramdisk subcommand 2940 is enabled. 2941 2942- CONFIG_SYS_BOOT_GET_CMDLINE: 2943 Enables allocating and saving kernel cmdline in space between 2944 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2945 2946- CONFIG_SYS_BOOT_GET_KBD: 2947 Enables allocating and saving a kernel copy of the bd_info in 2948 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2949 2950- CONFIG_SYS_MAX_FLASH_BANKS: 2951 Max number of Flash memory banks 2952 2953- CONFIG_SYS_MAX_FLASH_SECT: 2954 Max number of sectors on a Flash chip 2955 2956- CONFIG_SYS_FLASH_ERASE_TOUT: 2957 Timeout for Flash erase operations (in ms) 2958 2959- CONFIG_SYS_FLASH_WRITE_TOUT: 2960 Timeout for Flash write operations (in ms) 2961 2962- CONFIG_SYS_FLASH_LOCK_TOUT 2963 Timeout for Flash set sector lock bit operation (in ms) 2964 2965- CONFIG_SYS_FLASH_UNLOCK_TOUT 2966 Timeout for Flash clear lock bits operation (in ms) 2967 2968- CONFIG_SYS_FLASH_PROTECTION 2969 If defined, hardware flash sectors protection is used 2970 instead of U-Boot software protection. 2971 2972- CONFIG_SYS_DIRECT_FLASH_TFTP: 2973 2974 Enable TFTP transfers directly to flash memory; 2975 without this option such a download has to be 2976 performed in two steps: (1) download to RAM, and (2) 2977 copy from RAM to flash. 2978 2979 The two-step approach is usually more reliable, since 2980 you can check if the download worked before you erase 2981 the flash, but in some situations (when system RAM is 2982 too limited to allow for a temporary copy of the 2983 downloaded image) this option may be very useful. 2984 2985- CONFIG_SYS_FLASH_CFI: 2986 Define if the flash driver uses extra elements in the 2987 common flash structure for storing flash geometry. 2988 2989- CONFIG_FLASH_CFI_DRIVER 2990 This option also enables the building of the cfi_flash driver 2991 in the drivers directory 2992 2993- CONFIG_FLASH_CFI_MTD 2994 This option enables the building of the cfi_mtd driver 2995 in the drivers directory. The driver exports CFI flash 2996 to the MTD layer. 2997 2998- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2999 Use buffered writes to flash. 3000 3001- CONFIG_FLASH_SPANSION_S29WS_N 3002 s29ws-n MirrorBit flash has non-standard addresses for buffered 3003 write commands. 3004 3005- CONFIG_SYS_FLASH_QUIET_TEST 3006 If this option is defined, the common CFI flash doesn't 3007 print it's warning upon not recognized FLASH banks. This 3008 is useful, if some of the configured banks are only 3009 optionally available. 3010 3011- CONFIG_FLASH_SHOW_PROGRESS 3012 If defined (must be an integer), print out countdown 3013 digits and dots. Recommended value: 45 (9..1) for 80 3014 column displays, 15 (3..1) for 40 column displays. 3015 3016- CONFIG_FLASH_VERIFY 3017 If defined, the content of the flash (destination) is compared 3018 against the source after the write operation. An error message 3019 will be printed when the contents are not identical. 3020 Please note that this option is useless in nearly all cases, 3021 since such flash programming errors usually are detected earlier 3022 while unprotecting/erasing/programming. Please only enable 3023 this option if you really know what you are doing. 3024 3025- CONFIG_SYS_RX_ETH_BUFFER: 3026 Defines the number of Ethernet receive buffers. On some 3027 Ethernet controllers it is recommended to set this value 3028 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3029 buffers can be full shortly after enabling the interface 3030 on high Ethernet traffic. 3031 Defaults to 4 if not defined. 3032 3033- CONFIG_ENV_MAX_ENTRIES 3034 3035 Maximum number of entries in the hash table that is used 3036 internally to store the environment settings. The default 3037 setting is supposed to be generous and should work in most 3038 cases. This setting can be used to tune behaviour; see 3039 lib/hashtable.c for details. 3040 3041- CONFIG_ENV_FLAGS_LIST_DEFAULT 3042- CONFIG_ENV_FLAGS_LIST_STATIC 3043 Enable validation of the values given to environment variables when 3044 calling env set. Variables can be restricted to only decimal, 3045 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3046 the variables can also be restricted to IP address or MAC address. 3047 3048 The format of the list is: 3049 type_attribute = [s|d|x|b|i|m] 3050 access_attribute = [a|r|o|c] 3051 attributes = type_attribute[access_attribute] 3052 entry = variable_name[:attributes] 3053 list = entry[,list] 3054 3055 The type attributes are: 3056 s - String (default) 3057 d - Decimal 3058 x - Hexadecimal 3059 b - Boolean ([1yYtT|0nNfF]) 3060 i - IP address 3061 m - MAC address 3062 3063 The access attributes are: 3064 a - Any (default) 3065 r - Read-only 3066 o - Write-once 3067 c - Change-default 3068 3069 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3070 Define this to a list (string) to define the ".flags" 3071 environment variable in the default or embedded environment. 3072 3073 - CONFIG_ENV_FLAGS_LIST_STATIC 3074 Define this to a list (string) to define validation that 3075 should be done if an entry is not found in the ".flags" 3076 environment variable. To override a setting in the static 3077 list, simply add an entry for the same variable name to the 3078 ".flags" variable. 3079 3080 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3081 regular expression. This allows multiple variables to define the same 3082 flags without explicitly listing them for each variable. 3083 3084- CONFIG_ENV_ACCESS_IGNORE_FORCE 3085 If defined, don't allow the -f switch to env set override variable 3086 access flags. 3087 3088- CONFIG_USE_STDINT 3089 If stdint.h is available with your toolchain you can define this 3090 option to enable it. You can provide option 'USE_STDINT=1' when 3091 building U-Boot to enable this. 3092 3093The following definitions that deal with the placement and management 3094of environment data (variable area); in general, we support the 3095following configurations: 3096 3097- CONFIG_BUILD_ENVCRC: 3098 3099 Builds up envcrc with the target environment so that external utils 3100 may easily extract it and embed it in final U-Boot images. 3101 3102BE CAREFUL! The first access to the environment happens quite early 3103in U-Boot initialization (when we try to get the setting of for the 3104console baudrate). You *MUST* have mapped your NVRAM area then, or 3105U-Boot will hang. 3106 3107Please note that even with NVRAM we still use a copy of the 3108environment in RAM: we could work on NVRAM directly, but we want to 3109keep settings there always unmodified except somebody uses "saveenv" 3110to save the current settings. 3111 3112BE CAREFUL! For some special cases, the local device can not use 3113"saveenv" command. For example, the local device will get the 3114environment stored in a remote NOR flash by SRIO or PCIE link, 3115but it can not erase, write this NOR flash by SRIO or PCIE interface. 3116 3117- CONFIG_NAND_ENV_DST 3118 3119 Defines address in RAM to which the nand_spl code should copy the 3120 environment. If redundant environment is used, it will be copied to 3121 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3122 3123Please note that the environment is read-only until the monitor 3124has been relocated to RAM and a RAM copy of the environment has been 3125created; also, when using EEPROM you will have to use env_get_f() 3126until then to read environment variables. 3127 3128The environment is protected by a CRC32 checksum. Before the monitor 3129is relocated into RAM, as a result of a bad CRC you will be working 3130with the compiled-in default environment - *silently*!!! [This is 3131necessary, because the first environment variable we need is the 3132"baudrate" setting for the console - if we have a bad CRC, we don't 3133have any device yet where we could complain.] 3134 3135Note: once the monitor has been relocated, then it will complain if 3136the default environment is used; a new CRC is computed as soon as you 3137use the "saveenv" command to store a valid environment. 3138 3139- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3140 Echo the inverted Ethernet link state to the fault LED. 3141 3142 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3143 also needs to be defined. 3144 3145- CONFIG_SYS_FAULT_MII_ADDR: 3146 MII address of the PHY to check for the Ethernet link state. 3147 3148- CONFIG_NS16550_MIN_FUNCTIONS: 3149 Define this if you desire to only have use of the NS16550_init 3150 and NS16550_putc functions for the serial driver located at 3151 drivers/serial/ns16550.c. This option is useful for saving 3152 space for already greatly restricted images, including but not 3153 limited to NAND_SPL configurations. 3154 3155- CONFIG_DISPLAY_BOARDINFO 3156 Display information about the board that U-Boot is running on 3157 when U-Boot starts up. The board function checkboard() is called 3158 to do this. 3159 3160- CONFIG_DISPLAY_BOARDINFO_LATE 3161 Similar to the previous option, but display this information 3162 later, once stdio is running and output goes to the LCD, if 3163 present. 3164 3165- CONFIG_BOARD_SIZE_LIMIT: 3166 Maximum size of the U-Boot image. When defined, the 3167 build system checks that the actual size does not 3168 exceed it. 3169 3170Low Level (hardware related) configuration options: 3171--------------------------------------------------- 3172 3173- CONFIG_SYS_CACHELINE_SIZE: 3174 Cache Line Size of the CPU. 3175 3176- CONFIG_SYS_CCSRBAR_DEFAULT: 3177 Default (power-on reset) physical address of CCSR on Freescale 3178 PowerPC SOCs. 3179 3180- CONFIG_SYS_CCSRBAR: 3181 Virtual address of CCSR. On a 32-bit build, this is typically 3182 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3183 3184- CONFIG_SYS_CCSRBAR_PHYS: 3185 Physical address of CCSR. CCSR can be relocated to a new 3186 physical address, if desired. In this case, this macro should 3187 be set to that address. Otherwise, it should be set to the 3188 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3189 is typically relocated on 36-bit builds. It is recommended 3190 that this macro be defined via the _HIGH and _LOW macros: 3191 3192 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3193 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3194 3195- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3196 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3197 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3198 used in assembly code, so it must not contain typecasts or 3199 integer size suffixes (e.g. "ULL"). 3200 3201- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3202 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3203 used in assembly code, so it must not contain typecasts or 3204 integer size suffixes (e.g. "ULL"). 3205 3206- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3207 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3208 forced to a value that ensures that CCSR is not relocated. 3209 3210- Floppy Disk Support: 3211 CONFIG_SYS_FDC_DRIVE_NUMBER 3212 3213 the default drive number (default value 0) 3214 3215 CONFIG_SYS_ISA_IO_STRIDE 3216 3217 defines the spacing between FDC chipset registers 3218 (default value 1) 3219 3220 CONFIG_SYS_ISA_IO_OFFSET 3221 3222 defines the offset of register from address. It 3223 depends on which part of the data bus is connected to 3224 the FDC chipset. (default value 0) 3225 3226 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3227 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3228 default value. 3229 3230 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3231 fdc_hw_init() is called at the beginning of the FDC 3232 setup. fdc_hw_init() must be provided by the board 3233 source code. It is used to make hardware-dependent 3234 initializations. 3235 3236- CONFIG_IDE_AHB: 3237 Most IDE controllers were designed to be connected with PCI 3238 interface. Only few of them were designed for AHB interface. 3239 When software is doing ATA command and data transfer to 3240 IDE devices through IDE-AHB controller, some additional 3241 registers accessing to these kind of IDE-AHB controller 3242 is required. 3243 3244- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3245 DO NOT CHANGE unless you know exactly what you're 3246 doing! (11-4) [MPC8xx systems only] 3247 3248- CONFIG_SYS_INIT_RAM_ADDR: 3249 3250 Start address of memory area that can be used for 3251 initial data and stack; please note that this must be 3252 writable memory that is working WITHOUT special 3253 initialization, i. e. you CANNOT use normal RAM which 3254 will become available only after programming the 3255 memory controller and running certain initialization 3256 sequences. 3257 3258 U-Boot uses the following memory types: 3259 - MPC8xx: IMMR (internal memory of the CPU) 3260 3261- CONFIG_SYS_GBL_DATA_OFFSET: 3262 3263 Offset of the initial data structure in the memory 3264 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3265 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3266 data is located at the end of the available space 3267 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3268 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3269 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3270 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3271 3272 Note: 3273 On the MPC824X (or other systems that use the data 3274 cache for initial memory) the address chosen for 3275 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3276 point to an otherwise UNUSED address space between 3277 the top of RAM and the start of the PCI space. 3278 3279- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3280 3281- CONFIG_SYS_OR_TIMING_SDRAM: 3282 SDRAM timing 3283 3284- CONFIG_SYS_MAMR_PTA: 3285 periodic timer for refresh 3286 3287- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3288 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3289 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3290 CONFIG_SYS_BR1_PRELIM: 3291 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3292 3293- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3294 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3295 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3296 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3297 3298- CONFIG_PCI_ENUM_ONLY 3299 Only scan through and get the devices on the buses. 3300 Don't do any setup work, presumably because someone or 3301 something has already done it, and we don't need to do it 3302 a second time. Useful for platforms that are pre-booted 3303 by coreboot or similar. 3304 3305- CONFIG_PCI_INDIRECT_BRIDGE: 3306 Enable support for indirect PCI bridges. 3307 3308- CONFIG_SYS_SRIO: 3309 Chip has SRIO or not 3310 3311- CONFIG_SRIO1: 3312 Board has SRIO 1 port available 3313 3314- CONFIG_SRIO2: 3315 Board has SRIO 2 port available 3316 3317- CONFIG_SRIO_PCIE_BOOT_MASTER 3318 Board can support master function for Boot from SRIO and PCIE 3319 3320- CONFIG_SYS_SRIOn_MEM_VIRT: 3321 Virtual Address of SRIO port 'n' memory region 3322 3323- CONFIG_SYS_SRIOn_MEM_PHYS: 3324 Physical Address of SRIO port 'n' memory region 3325 3326- CONFIG_SYS_SRIOn_MEM_SIZE: 3327 Size of SRIO port 'n' memory region 3328 3329- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3330 Defined to tell the NAND controller that the NAND chip is using 3331 a 16 bit bus. 3332 Not all NAND drivers use this symbol. 3333 Example of drivers that use it: 3334 - drivers/mtd/nand/ndfc.c 3335 - drivers/mtd/nand/mxc_nand.c 3336 3337- CONFIG_SYS_NDFC_EBC0_CFG 3338 Sets the EBC0_CFG register for the NDFC. If not defined 3339 a default value will be used. 3340 3341- CONFIG_SPD_EEPROM 3342 Get DDR timing information from an I2C EEPROM. Common 3343 with pluggable memory modules such as SODIMMs 3344 3345 SPD_EEPROM_ADDRESS 3346 I2C address of the SPD EEPROM 3347 3348- CONFIG_SYS_SPD_BUS_NUM 3349 If SPD EEPROM is on an I2C bus other than the first 3350 one, specify here. Note that the value must resolve 3351 to something your driver can deal with. 3352 3353- CONFIG_SYS_DDR_RAW_TIMING 3354 Get DDR timing information from other than SPD. Common with 3355 soldered DDR chips onboard without SPD. DDR raw timing 3356 parameters are extracted from datasheet and hard-coded into 3357 header files or board specific files. 3358 3359- CONFIG_FSL_DDR_INTERACTIVE 3360 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3361 3362- CONFIG_FSL_DDR_SYNC_REFRESH 3363 Enable sync of refresh for multiple controllers. 3364 3365- CONFIG_FSL_DDR_BIST 3366 Enable built-in memory test for Freescale DDR controllers. 3367 3368- CONFIG_SYS_83XX_DDR_USES_CS0 3369 Only for 83xx systems. If specified, then DDR should 3370 be configured using CS0 and CS1 instead of CS2 and CS3. 3371 3372- CONFIG_RMII 3373 Enable RMII mode for all FECs. 3374 Note that this is a global option, we can't 3375 have one FEC in standard MII mode and another in RMII mode. 3376 3377- CONFIG_CRC32_VERIFY 3378 Add a verify option to the crc32 command. 3379 The syntax is: 3380 3381 => crc32 -v <address> <count> <crc32> 3382 3383 Where address/count indicate a memory area 3384 and crc32 is the correct crc32 which the 3385 area should have. 3386 3387- CONFIG_LOOPW 3388 Add the "loopw" memory command. This only takes effect if 3389 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3390 3391- CONFIG_MX_CYCLIC 3392 Add the "mdc" and "mwc" memory commands. These are cyclic 3393 "md/mw" commands. 3394 Examples: 3395 3396 => mdc.b 10 4 500 3397 This command will print 4 bytes (10,11,12,13) each 500 ms. 3398 3399 => mwc.l 100 12345678 10 3400 This command will write 12345678 to address 100 all 10 ms. 3401 3402 This only takes effect if the memory commands are activated 3403 globally (CONFIG_CMD_MEMORY). 3404 3405- CONFIG_SKIP_LOWLEVEL_INIT 3406 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3407 low level initializations (like setting up the memory 3408 controller) are omitted and/or U-Boot does not 3409 relocate itself into RAM. 3410 3411 Normally this variable MUST NOT be defined. The only 3412 exception is when U-Boot is loaded (to RAM) by some 3413 other boot loader or by a debugger which performs 3414 these initializations itself. 3415 3416- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3417 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3418 to be skipped. The normal CP15 init (such as enabling the 3419 instruction cache) is still performed. 3420 3421- CONFIG_SPL_BUILD 3422 Modifies the behaviour of start.S when compiling a loader 3423 that is executed before the actual U-Boot. E.g. when 3424 compiling a NAND SPL. 3425 3426- CONFIG_TPL_BUILD 3427 Modifies the behaviour of start.S when compiling a loader 3428 that is executed after the SPL and before the actual U-Boot. 3429 It is loaded by the SPL. 3430 3431- CONFIG_SYS_MPC85XX_NO_RESETVEC 3432 Only for 85xx systems. If this variable is specified, the section 3433 .resetvec is not kept and the section .bootpg is placed in the 3434 previous 4k of the .text section. 3435 3436- CONFIG_ARCH_MAP_SYSMEM 3437 Generally U-Boot (and in particular the md command) uses 3438 effective address. It is therefore not necessary to regard 3439 U-Boot address as virtual addresses that need to be translated 3440 to physical addresses. However, sandbox requires this, since 3441 it maintains its own little RAM buffer which contains all 3442 addressable memory. This option causes some memory accesses 3443 to be mapped through map_sysmem() / unmap_sysmem(). 3444 3445- CONFIG_X86_RESET_VECTOR 3446 If defined, the x86 reset vector code is included. This is not 3447 needed when U-Boot is running from Coreboot. 3448 3449- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3450 Enables the RTC32K OSC on AM33xx based plattforms 3451 3452- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3453 Option to disable subpage write in NAND driver 3454 driver that uses this: 3455 drivers/mtd/nand/davinci_nand.c 3456 3457Freescale QE/FMAN Firmware Support: 3458----------------------------------- 3459 3460The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3461loading of "firmware", which is encoded in the QE firmware binary format. 3462This firmware often needs to be loaded during U-Boot booting, so macros 3463are used to identify the storage device (NOR flash, SPI, etc) and the address 3464within that device. 3465 3466- CONFIG_SYS_FMAN_FW_ADDR 3467 The address in the storage device where the FMAN microcode is located. The 3468 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3469 is also specified. 3470 3471- CONFIG_SYS_QE_FW_ADDR 3472 The address in the storage device where the QE microcode is located. The 3473 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3474 is also specified. 3475 3476- CONFIG_SYS_QE_FMAN_FW_LENGTH 3477 The maximum possible size of the firmware. The firmware binary format 3478 has a field that specifies the actual size of the firmware, but it 3479 might not be possible to read any part of the firmware unless some 3480 local storage is allocated to hold the entire firmware first. 3481 3482- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3483 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3484 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3485 virtual address in NOR flash. 3486 3487- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3488 Specifies that QE/FMAN firmware is located in NAND flash. 3489 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3490 3491- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3492 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3493 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3494 3495- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3496 Specifies that QE/FMAN firmware is located in the remote (master) 3497 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3498 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3499 window->master inbound window->master LAW->the ucode address in 3500 master's memory space. 3501 3502Freescale Layerscape Management Complex Firmware Support: 3503--------------------------------------------------------- 3504The Freescale Layerscape Management Complex (MC) supports the loading of 3505"firmware". 3506This firmware often needs to be loaded during U-Boot booting, so macros 3507are used to identify the storage device (NOR flash, SPI, etc) and the address 3508within that device. 3509 3510- CONFIG_FSL_MC_ENET 3511 Enable the MC driver for Layerscape SoCs. 3512 3513Freescale Layerscape Debug Server Support: 3514------------------------------------------- 3515The Freescale Layerscape Debug Server Support supports the loading of 3516"Debug Server firmware" and triggering SP boot-rom. 3517This firmware often needs to be loaded during U-Boot booting. 3518 3519- CONFIG_SYS_MC_RSV_MEM_ALIGN 3520 Define alignment of reserved memory MC requires 3521 3522Reproducible builds 3523------------------- 3524 3525In order to achieve reproducible builds, timestamps used in the U-Boot build 3526process have to be set to a fixed value. 3527 3528This is done using the SOURCE_DATE_EPOCH environment variable. 3529SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3530option for U-Boot or an environment variable in U-Boot. 3531 3532SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3533 3534Building the Software: 3535====================== 3536 3537Building U-Boot has been tested in several native build environments 3538and in many different cross environments. Of course we cannot support 3539all possibly existing versions of cross development tools in all 3540(potentially obsolete) versions. In case of tool chain problems we 3541recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3542which is extensively used to build and test U-Boot. 3543 3544If you are not using a native environment, it is assumed that you 3545have GNU cross compiling tools available in your path. In this case, 3546you must set the environment variable CROSS_COMPILE in your shell. 3547Note that no changes to the Makefile or any other source files are 3548necessary. For example using the ELDK on a 4xx CPU, please enter: 3549 3550 $ CROSS_COMPILE=ppc_4xx- 3551 $ export CROSS_COMPILE 3552 3553Note: If you wish to generate Windows versions of the utilities in 3554 the tools directory you can use the MinGW toolchain 3555 (http://www.mingw.org). Set your HOST tools to the MinGW 3556 toolchain and execute 'make tools'. For example: 3557 3558 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3559 3560 Binaries such as tools/mkimage.exe will be created which can 3561 be executed on computers running Windows. 3562 3563U-Boot is intended to be simple to build. After installing the 3564sources you must configure U-Boot for one specific board type. This 3565is done by typing: 3566 3567 make NAME_defconfig 3568 3569where "NAME_defconfig" is the name of one of the existing configu- 3570rations; see boards.cfg for supported names. 3571 3572Note: for some board special configuration names may exist; check if 3573 additional information is available from the board vendor; for 3574 instance, the TQM823L systems are available without (standard) 3575 or with LCD support. You can select such additional "features" 3576 when choosing the configuration, i. e. 3577 3578 make TQM823L_defconfig 3579 - will configure for a plain TQM823L, i. e. no LCD support 3580 3581 make TQM823L_LCD_defconfig 3582 - will configure for a TQM823L with U-Boot console on LCD 3583 3584 etc. 3585 3586 3587Finally, type "make all", and you should get some working U-Boot 3588images ready for download to / installation on your system: 3589 3590- "u-boot.bin" is a raw binary image 3591- "u-boot" is an image in ELF binary format 3592- "u-boot.srec" is in Motorola S-Record format 3593 3594By default the build is performed locally and the objects are saved 3595in the source directory. One of the two methods can be used to change 3596this behavior and build U-Boot to some external directory: 3597 35981. Add O= to the make command line invocations: 3599 3600 make O=/tmp/build distclean 3601 make O=/tmp/build NAME_defconfig 3602 make O=/tmp/build all 3603 36042. Set environment variable KBUILD_OUTPUT to point to the desired location: 3605 3606 export KBUILD_OUTPUT=/tmp/build 3607 make distclean 3608 make NAME_defconfig 3609 make all 3610 3611Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3612variable. 3613 3614User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3615setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3616For example to treat all compiler warnings as errors: 3617 3618 make KCFLAGS=-Werror 3619 3620Please be aware that the Makefiles assume you are using GNU make, so 3621for instance on NetBSD you might need to use "gmake" instead of 3622native "make". 3623 3624 3625If the system board that you have is not listed, then you will need 3626to port U-Boot to your hardware platform. To do this, follow these 3627steps: 3628 36291. Create a new directory to hold your board specific code. Add any 3630 files you need. In your board directory, you will need at least 3631 the "Makefile" and a "<board>.c". 36322. Create a new configuration file "include/configs/<board>.h" for 3633 your board. 36343. If you're porting U-Boot to a new CPU, then also create a new 3635 directory to hold your CPU specific code. Add any files you need. 36364. Run "make <board>_defconfig" with your new name. 36375. Type "make", and you should get a working "u-boot.srec" file 3638 to be installed on your target system. 36396. Debug and solve any problems that might arise. 3640 [Of course, this last step is much harder than it sounds.] 3641 3642 3643Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3644============================================================== 3645 3646If you have modified U-Boot sources (for instance added a new board 3647or support for new devices, a new CPU, etc.) you are expected to 3648provide feedback to the other developers. The feedback normally takes 3649the form of a "patch", i. e. a context diff against a certain (latest 3650official or latest in the git repository) version of U-Boot sources. 3651 3652But before you submit such a patch, please verify that your modifi- 3653cation did not break existing code. At least make sure that *ALL* of 3654the supported boards compile WITHOUT ANY compiler warnings. To do so, 3655just run the buildman script (tools/buildman/buildman), which will 3656configure and build U-Boot for ALL supported system. Be warned, this 3657will take a while. Please see the buildman README, or run 'buildman -H' 3658for documentation. 3659 3660 3661See also "U-Boot Porting Guide" below. 3662 3663 3664Monitor Commands - Overview: 3665============================ 3666 3667go - start application at address 'addr' 3668run - run commands in an environment variable 3669bootm - boot application image from memory 3670bootp - boot image via network using BootP/TFTP protocol 3671bootz - boot zImage from memory 3672tftpboot- boot image via network using TFTP protocol 3673 and env variables "ipaddr" and "serverip" 3674 (and eventually "gatewayip") 3675tftpput - upload a file via network using TFTP protocol 3676rarpboot- boot image via network using RARP/TFTP protocol 3677diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3678loads - load S-Record file over serial line 3679loadb - load binary file over serial line (kermit mode) 3680md - memory display 3681mm - memory modify (auto-incrementing) 3682nm - memory modify (constant address) 3683mw - memory write (fill) 3684cp - memory copy 3685cmp - memory compare 3686crc32 - checksum calculation 3687i2c - I2C sub-system 3688sspi - SPI utility commands 3689base - print or set address offset 3690printenv- print environment variables 3691setenv - set environment variables 3692saveenv - save environment variables to persistent storage 3693protect - enable or disable FLASH write protection 3694erase - erase FLASH memory 3695flinfo - print FLASH memory information 3696nand - NAND memory operations (see doc/README.nand) 3697bdinfo - print Board Info structure 3698iminfo - print header information for application image 3699coninfo - print console devices and informations 3700ide - IDE sub-system 3701loop - infinite loop on address range 3702loopw - infinite write loop on address range 3703mtest - simple RAM test 3704icache - enable or disable instruction cache 3705dcache - enable or disable data cache 3706reset - Perform RESET of the CPU 3707echo - echo args to console 3708version - print monitor version 3709help - print online help 3710? - alias for 'help' 3711 3712 3713Monitor Commands - Detailed Description: 3714======================================== 3715 3716TODO. 3717 3718For now: just type "help <command>". 3719 3720 3721Environment Variables: 3722====================== 3723 3724U-Boot supports user configuration using Environment Variables which 3725can be made persistent by saving to Flash memory. 3726 3727Environment Variables are set using "setenv", printed using 3728"printenv", and saved to Flash using "saveenv". Using "setenv" 3729without a value can be used to delete a variable from the 3730environment. As long as you don't save the environment you are 3731working with an in-memory copy. In case the Flash area containing the 3732environment is erased by accident, a default environment is provided. 3733 3734Some configuration options can be set using Environment Variables. 3735 3736List of environment variables (most likely not complete): 3737 3738 baudrate - see CONFIG_BAUDRATE 3739 3740 bootdelay - see CONFIG_BOOTDELAY 3741 3742 bootcmd - see CONFIG_BOOTCOMMAND 3743 3744 bootargs - Boot arguments when booting an RTOS image 3745 3746 bootfile - Name of the image to load with TFTP 3747 3748 bootm_low - Memory range available for image processing in the bootm 3749 command can be restricted. This variable is given as 3750 a hexadecimal number and defines lowest address allowed 3751 for use by the bootm command. See also "bootm_size" 3752 environment variable. Address defined by "bootm_low" is 3753 also the base of the initial memory mapping for the Linux 3754 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3755 bootm_mapsize. 3756 3757 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3758 This variable is given as a hexadecimal number and it 3759 defines the size of the memory region starting at base 3760 address bootm_low that is accessible by the Linux kernel 3761 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3762 as the default value if it is defined, and bootm_size is 3763 used otherwise. 3764 3765 bootm_size - Memory range available for image processing in the bootm 3766 command can be restricted. This variable is given as 3767 a hexadecimal number and defines the size of the region 3768 allowed for use by the bootm command. See also "bootm_low" 3769 environment variable. 3770 3771 updatefile - Location of the software update file on a TFTP server, used 3772 by the automatic software update feature. Please refer to 3773 documentation in doc/README.update for more details. 3774 3775 autoload - if set to "no" (any string beginning with 'n'), 3776 "bootp" will just load perform a lookup of the 3777 configuration from the BOOTP server, but not try to 3778 load any image using TFTP 3779 3780 autostart - if set to "yes", an image loaded using the "bootp", 3781 "rarpboot", "tftpboot" or "diskboot" commands will 3782 be automatically started (by internally calling 3783 "bootm") 3784 3785 If set to "no", a standalone image passed to the 3786 "bootm" command will be copied to the load address 3787 (and eventually uncompressed), but NOT be started. 3788 This can be used to load and uncompress arbitrary 3789 data. 3790 3791 fdt_high - if set this restricts the maximum address that the 3792 flattened device tree will be copied into upon boot. 3793 For example, if you have a system with 1 GB memory 3794 at physical address 0x10000000, while Linux kernel 3795 only recognizes the first 704 MB as low memory, you 3796 may need to set fdt_high as 0x3C000000 to have the 3797 device tree blob be copied to the maximum address 3798 of the 704 MB low memory, so that Linux kernel can 3799 access it during the boot procedure. 3800 3801 If this is set to the special value 0xFFFFFFFF then 3802 the fdt will not be copied at all on boot. For this 3803 to work it must reside in writable memory, have 3804 sufficient padding on the end of it for u-boot to 3805 add the information it needs into it, and the memory 3806 must be accessible by the kernel. 3807 3808 fdtcontroladdr- if set this is the address of the control flattened 3809 device tree used by U-Boot when CONFIG_OF_CONTROL is 3810 defined. 3811 3812 i2cfast - (PPC405GP|PPC405EP only) 3813 if set to 'y' configures Linux I2C driver for fast 3814 mode (400kHZ). This environment variable is used in 3815 initialization code. So, for changes to be effective 3816 it must be saved and board must be reset. 3817 3818 initrd_high - restrict positioning of initrd images: 3819 If this variable is not set, initrd images will be 3820 copied to the highest possible address in RAM; this 3821 is usually what you want since it allows for 3822 maximum initrd size. If for some reason you want to 3823 make sure that the initrd image is loaded below the 3824 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3825 variable to a value of "no" or "off" or "0". 3826 Alternatively, you can set it to a maximum upper 3827 address to use (U-Boot will still check that it 3828 does not overwrite the U-Boot stack and data). 3829 3830 For instance, when you have a system with 16 MB 3831 RAM, and want to reserve 4 MB from use by Linux, 3832 you can do this by adding "mem=12M" to the value of 3833 the "bootargs" variable. However, now you must make 3834 sure that the initrd image is placed in the first 3835 12 MB as well - this can be done with 3836 3837 setenv initrd_high 00c00000 3838 3839 If you set initrd_high to 0xFFFFFFFF, this is an 3840 indication to U-Boot that all addresses are legal 3841 for the Linux kernel, including addresses in flash 3842 memory. In this case U-Boot will NOT COPY the 3843 ramdisk at all. This may be useful to reduce the 3844 boot time on your system, but requires that this 3845 feature is supported by your Linux kernel. 3846 3847 ipaddr - IP address; needed for tftpboot command 3848 3849 loadaddr - Default load address for commands like "bootp", 3850 "rarpboot", "tftpboot", "loadb" or "diskboot" 3851 3852 loads_echo - see CONFIG_LOADS_ECHO 3853 3854 serverip - TFTP server IP address; needed for tftpboot command 3855 3856 bootretry - see CONFIG_BOOT_RETRY_TIME 3857 3858 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3859 3860 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3861 3862 ethprime - controls which interface is used first. 3863 3864 ethact - controls which interface is currently active. 3865 For example you can do the following 3866 3867 => setenv ethact FEC 3868 => ping 192.168.0.1 # traffic sent on FEC 3869 => setenv ethact SCC 3870 => ping 10.0.0.1 # traffic sent on SCC 3871 3872 ethrotate - When set to "no" U-Boot does not go through all 3873 available network interfaces. 3874 It just stays at the currently selected interface. 3875 3876 netretry - When set to "no" each network operation will 3877 either succeed or fail without retrying. 3878 When set to "once" the network operation will 3879 fail when all the available network interfaces 3880 are tried once without success. 3881 Useful on scripts which control the retry operation 3882 themselves. 3883 3884 npe_ucode - set load address for the NPE microcode 3885 3886 silent_linux - If set then Linux will be told to boot silently, by 3887 changing the console to be empty. If "yes" it will be 3888 made silent. If "no" it will not be made silent. If 3889 unset, then it will be made silent if the U-Boot console 3890 is silent. 3891 3892 tftpsrcp - If this is set, the value is used for TFTP's 3893 UDP source port. 3894 3895 tftpdstp - If this is set, the value is used for TFTP's UDP 3896 destination port instead of the Well Know Port 69. 3897 3898 tftpblocksize - Block size to use for TFTP transfers; if not set, 3899 we use the TFTP server's default block size 3900 3901 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3902 seconds, minimum value is 1000 = 1 second). Defines 3903 when a packet is considered to be lost so it has to 3904 be retransmitted. The default is 5000 = 5 seconds. 3905 Lowering this value may make downloads succeed 3906 faster in networks with high packet loss rates or 3907 with unreliable TFTP servers. 3908 3909 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3910 unit, minimum value = 0). Defines how many timeouts 3911 can happen during a single file transfer before that 3912 transfer is aborted. The default is 10, and 0 means 3913 'no timeouts allowed'. Increasing this value may help 3914 downloads succeed with high packet loss rates, or with 3915 unreliable TFTP servers or client hardware. 3916 3917 vlan - When set to a value < 4095 the traffic over 3918 Ethernet is encapsulated/received over 802.1q 3919 VLAN tagged frames. 3920 3921 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3922 Unsigned value, in milliseconds. If not set, the period will 3923 be either the default (28000), or a value based on 3924 CONFIG_NET_RETRY_COUNT, if defined. This value has 3925 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3926 3927The following image location variables contain the location of images 3928used in booting. The "Image" column gives the role of the image and is 3929not an environment variable name. The other columns are environment 3930variable names. "File Name" gives the name of the file on a TFTP 3931server, "RAM Address" gives the location in RAM the image will be 3932loaded to, and "Flash Location" gives the image's address in NOR 3933flash or offset in NAND flash. 3934 3935*Note* - these variables don't have to be defined for all boards, some 3936boards currently use other variables for these purposes, and some 3937boards use these variables for other purposes. 3938 3939Image File Name RAM Address Flash Location 3940----- --------- ----------- -------------- 3941u-boot u-boot u-boot_addr_r u-boot_addr 3942Linux kernel bootfile kernel_addr_r kernel_addr 3943device tree blob fdtfile fdt_addr_r fdt_addr 3944ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3945 3946The following environment variables may be used and automatically 3947updated by the network boot commands ("bootp" and "rarpboot"), 3948depending the information provided by your boot server: 3949 3950 bootfile - see above 3951 dnsip - IP address of your Domain Name Server 3952 dnsip2 - IP address of your secondary Domain Name Server 3953 gatewayip - IP address of the Gateway (Router) to use 3954 hostname - Target hostname 3955 ipaddr - see above 3956 netmask - Subnet Mask 3957 rootpath - Pathname of the root filesystem on the NFS server 3958 serverip - see above 3959 3960 3961There are two special Environment Variables: 3962 3963 serial# - contains hardware identification information such 3964 as type string and/or serial number 3965 ethaddr - Ethernet address 3966 3967These variables can be set only once (usually during manufacturing of 3968the board). U-Boot refuses to delete or overwrite these variables 3969once they have been set once. 3970 3971 3972Further special Environment Variables: 3973 3974 ver - Contains the U-Boot version string as printed 3975 with the "version" command. This variable is 3976 readonly (see CONFIG_VERSION_VARIABLE). 3977 3978 3979Please note that changes to some configuration parameters may take 3980only effect after the next boot (yes, that's just like Windoze :-). 3981 3982 3983Callback functions for environment variables: 3984--------------------------------------------- 3985 3986For some environment variables, the behavior of u-boot needs to change 3987when their values are changed. This functionality allows functions to 3988be associated with arbitrary variables. On creation, overwrite, or 3989deletion, the callback will provide the opportunity for some side 3990effect to happen or for the change to be rejected. 3991 3992The callbacks are named and associated with a function using the 3993U_BOOT_ENV_CALLBACK macro in your board or driver code. 3994 3995These callbacks are associated with variables in one of two ways. The 3996static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3997in the board configuration to a string that defines a list of 3998associations. The list must be in the following format: 3999 4000 entry = variable_name[:callback_name] 4001 list = entry[,list] 4002 4003If the callback name is not specified, then the callback is deleted. 4004Spaces are also allowed anywhere in the list. 4005 4006Callbacks can also be associated by defining the ".callbacks" variable 4007with the same list format above. Any association in ".callbacks" will 4008override any association in the static list. You can define 4009CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4010".callbacks" environment variable in the default or embedded environment. 4011 4012If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4013regular expression. This allows multiple variables to be connected to 4014the same callback without explicitly listing them all out. 4015 4016 4017Command Line Parsing: 4018===================== 4019 4020There are two different command line parsers available with U-Boot: 4021the old "simple" one, and the much more powerful "hush" shell: 4022 4023Old, simple command line parser: 4024-------------------------------- 4025 4026- supports environment variables (through setenv / saveenv commands) 4027- several commands on one line, separated by ';' 4028- variable substitution using "... ${name} ..." syntax 4029- special characters ('$', ';') can be escaped by prefixing with '\', 4030 for example: 4031 setenv bootcmd bootm \${address} 4032- You can also escape text by enclosing in single apostrophes, for example: 4033 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4034 4035Hush shell: 4036----------- 4037 4038- similar to Bourne shell, with control structures like 4039 if...then...else...fi, for...do...done; while...do...done, 4040 until...do...done, ... 4041- supports environment ("global") variables (through setenv / saveenv 4042 commands) and local shell variables (through standard shell syntax 4043 "name=value"); only environment variables can be used with "run" 4044 command 4045 4046General rules: 4047-------------- 4048 4049(1) If a command line (or an environment variable executed by a "run" 4050 command) contains several commands separated by semicolon, and 4051 one of these commands fails, then the remaining commands will be 4052 executed anyway. 4053 4054(2) If you execute several variables with one call to run (i. e. 4055 calling run with a list of variables as arguments), any failing 4056 command will cause "run" to terminate, i. e. the remaining 4057 variables are not executed. 4058 4059Note for Redundant Ethernet Interfaces: 4060======================================= 4061 4062Some boards come with redundant Ethernet interfaces; U-Boot supports 4063such configurations and is capable of automatic selection of a 4064"working" interface when needed. MAC assignment works as follows: 4065 4066Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4067MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4068"eth1addr" (=>eth1), "eth2addr", ... 4069 4070If the network interface stores some valid MAC address (for instance 4071in SROM), this is used as default address if there is NO correspon- 4072ding setting in the environment; if the corresponding environment 4073variable is set, this overrides the settings in the card; that means: 4074 4075o If the SROM has a valid MAC address, and there is no address in the 4076 environment, the SROM's address is used. 4077 4078o If there is no valid address in the SROM, and a definition in the 4079 environment exists, then the value from the environment variable is 4080 used. 4081 4082o If both the SROM and the environment contain a MAC address, and 4083 both addresses are the same, this MAC address is used. 4084 4085o If both the SROM and the environment contain a MAC address, and the 4086 addresses differ, the value from the environment is used and a 4087 warning is printed. 4088 4089o If neither SROM nor the environment contain a MAC address, an error 4090 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4091 a random, locally-assigned MAC is used. 4092 4093If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4094will be programmed into hardware as part of the initialization process. This 4095may be skipped by setting the appropriate 'ethmacskip' environment variable. 4096The naming convention is as follows: 4097"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4098 4099Image Formats: 4100============== 4101 4102U-Boot is capable of booting (and performing other auxiliary operations on) 4103images in two formats: 4104 4105New uImage format (FIT) 4106----------------------- 4107 4108Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4109to Flattened Device Tree). It allows the use of images with multiple 4110components (several kernels, ramdisks, etc.), with contents protected by 4111SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4112 4113 4114Old uImage format 4115----------------- 4116 4117Old image format is based on binary files which can be basically anything, 4118preceded by a special header; see the definitions in include/image.h for 4119details; basically, the header defines the following image properties: 4120 4121* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4122 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4123 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4124 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4125 INTEGRITY). 4126* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4127 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4128 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4129* Compression Type (uncompressed, gzip, bzip2) 4130* Load Address 4131* Entry Point 4132* Image Name 4133* Image Timestamp 4134 4135The header is marked by a special Magic Number, and both the header 4136and the data portions of the image are secured against corruption by 4137CRC32 checksums. 4138 4139 4140Linux Support: 4141============== 4142 4143Although U-Boot should support any OS or standalone application 4144easily, the main focus has always been on Linux during the design of 4145U-Boot. 4146 4147U-Boot includes many features that so far have been part of some 4148special "boot loader" code within the Linux kernel. Also, any 4149"initrd" images to be used are no longer part of one big Linux image; 4150instead, kernel and "initrd" are separate images. This implementation 4151serves several purposes: 4152 4153- the same features can be used for other OS or standalone 4154 applications (for instance: using compressed images to reduce the 4155 Flash memory footprint) 4156 4157- it becomes much easier to port new Linux kernel versions because 4158 lots of low-level, hardware dependent stuff are done by U-Boot 4159 4160- the same Linux kernel image can now be used with different "initrd" 4161 images; of course this also means that different kernel images can 4162 be run with the same "initrd". This makes testing easier (you don't 4163 have to build a new "zImage.initrd" Linux image when you just 4164 change a file in your "initrd"). Also, a field-upgrade of the 4165 software is easier now. 4166 4167 4168Linux HOWTO: 4169============ 4170 4171Porting Linux to U-Boot based systems: 4172--------------------------------------- 4173 4174U-Boot cannot save you from doing all the necessary modifications to 4175configure the Linux device drivers for use with your target hardware 4176(no, we don't intend to provide a full virtual machine interface to 4177Linux :-). 4178 4179But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4180 4181Just make sure your machine specific header file (for instance 4182include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4183Information structure as we define in include/asm-<arch>/u-boot.h, 4184and make sure that your definition of IMAP_ADDR uses the same value 4185as your U-Boot configuration in CONFIG_SYS_IMMR. 4186 4187Note that U-Boot now has a driver model, a unified model for drivers. 4188If you are adding a new driver, plumb it into driver model. If there 4189is no uclass available, you are encouraged to create one. See 4190doc/driver-model. 4191 4192 4193Configuring the Linux kernel: 4194----------------------------- 4195 4196No specific requirements for U-Boot. Make sure you have some root 4197device (initial ramdisk, NFS) for your target system. 4198 4199 4200Building a Linux Image: 4201----------------------- 4202 4203With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4204not used. If you use recent kernel source, a new build target 4205"uImage" will exist which automatically builds an image usable by 4206U-Boot. Most older kernels also have support for a "pImage" target, 4207which was introduced for our predecessor project PPCBoot and uses a 4208100% compatible format. 4209 4210Example: 4211 4212 make TQM850L_defconfig 4213 make oldconfig 4214 make dep 4215 make uImage 4216 4217The "uImage" build target uses a special tool (in 'tools/mkimage') to 4218encapsulate a compressed Linux kernel image with header information, 4219CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4220 4221* build a standard "vmlinux" kernel image (in ELF binary format): 4222 4223* convert the kernel into a raw binary image: 4224 4225 ${CROSS_COMPILE}-objcopy -O binary \ 4226 -R .note -R .comment \ 4227 -S vmlinux linux.bin 4228 4229* compress the binary image: 4230 4231 gzip -9 linux.bin 4232 4233* package compressed binary image for U-Boot: 4234 4235 mkimage -A ppc -O linux -T kernel -C gzip \ 4236 -a 0 -e 0 -n "Linux Kernel Image" \ 4237 -d linux.bin.gz uImage 4238 4239 4240The "mkimage" tool can also be used to create ramdisk images for use 4241with U-Boot, either separated from the Linux kernel image, or 4242combined into one file. "mkimage" encapsulates the images with a 64 4243byte header containing information about target architecture, 4244operating system, image type, compression method, entry points, time 4245stamp, CRC32 checksums, etc. 4246 4247"mkimage" can be called in two ways: to verify existing images and 4248print the header information, or to build new images. 4249 4250In the first form (with "-l" option) mkimage lists the information 4251contained in the header of an existing U-Boot image; this includes 4252checksum verification: 4253 4254 tools/mkimage -l image 4255 -l ==> list image header information 4256 4257The second form (with "-d" option) is used to build a U-Boot image 4258from a "data file" which is used as image payload: 4259 4260 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4261 -n name -d data_file image 4262 -A ==> set architecture to 'arch' 4263 -O ==> set operating system to 'os' 4264 -T ==> set image type to 'type' 4265 -C ==> set compression type 'comp' 4266 -a ==> set load address to 'addr' (hex) 4267 -e ==> set entry point to 'ep' (hex) 4268 -n ==> set image name to 'name' 4269 -d ==> use image data from 'datafile' 4270 4271Right now, all Linux kernels for PowerPC systems use the same load 4272address (0x00000000), but the entry point address depends on the 4273kernel version: 4274 4275- 2.2.x kernels have the entry point at 0x0000000C, 4276- 2.3.x and later kernels have the entry point at 0x00000000. 4277 4278So a typical call to build a U-Boot image would read: 4279 4280 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4281 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4282 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4283 > examples/uImage.TQM850L 4284 Image Name: 2.4.4 kernel for TQM850L 4285 Created: Wed Jul 19 02:34:59 2000 4286 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4287 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4288 Load Address: 0x00000000 4289 Entry Point: 0x00000000 4290 4291To verify the contents of the image (or check for corruption): 4292 4293 -> tools/mkimage -l examples/uImage.TQM850L 4294 Image Name: 2.4.4 kernel for TQM850L 4295 Created: Wed Jul 19 02:34:59 2000 4296 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4297 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4298 Load Address: 0x00000000 4299 Entry Point: 0x00000000 4300 4301NOTE: for embedded systems where boot time is critical you can trade 4302speed for memory and install an UNCOMPRESSED image instead: this 4303needs more space in Flash, but boots much faster since it does not 4304need to be uncompressed: 4305 4306 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4307 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4308 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4309 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4310 > examples/uImage.TQM850L-uncompressed 4311 Image Name: 2.4.4 kernel for TQM850L 4312 Created: Wed Jul 19 02:34:59 2000 4313 Image Type: PowerPC Linux Kernel Image (uncompressed) 4314 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4315 Load Address: 0x00000000 4316 Entry Point: 0x00000000 4317 4318 4319Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4320when your kernel is intended to use an initial ramdisk: 4321 4322 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4323 > -A ppc -O linux -T ramdisk -C gzip \ 4324 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4325 Image Name: Simple Ramdisk Image 4326 Created: Wed Jan 12 14:01:50 2000 4327 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4328 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4329 Load Address: 0x00000000 4330 Entry Point: 0x00000000 4331 4332The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4333option performs the converse operation of the mkimage's second form (the "-d" 4334option). Given an image built by mkimage, the dumpimage extracts a "data file" 4335from the image: 4336 4337 tools/dumpimage -i image -T type -p position data_file 4338 -i ==> extract from the 'image' a specific 'data_file' 4339 -T ==> set image type to 'type' 4340 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4341 4342 4343Installing a Linux Image: 4344------------------------- 4345 4346To downloading a U-Boot image over the serial (console) interface, 4347you must convert the image to S-Record format: 4348 4349 objcopy -I binary -O srec examples/image examples/image.srec 4350 4351The 'objcopy' does not understand the information in the U-Boot 4352image header, so the resulting S-Record file will be relative to 4353address 0x00000000. To load it to a given address, you need to 4354specify the target address as 'offset' parameter with the 'loads' 4355command. 4356 4357Example: install the image to address 0x40100000 (which on the 4358TQM8xxL is in the first Flash bank): 4359 4360 => erase 40100000 401FFFFF 4361 4362 .......... done 4363 Erased 8 sectors 4364 4365 => loads 40100000 4366 ## Ready for S-Record download ... 4367 ~>examples/image.srec 4368 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4369 ... 4370 15989 15990 15991 15992 4371 [file transfer complete] 4372 [connected] 4373 ## Start Addr = 0x00000000 4374 4375 4376You can check the success of the download using the 'iminfo' command; 4377this includes a checksum verification so you can be sure no data 4378corruption happened: 4379 4380 => imi 40100000 4381 4382 ## Checking Image at 40100000 ... 4383 Image Name: 2.2.13 for initrd on TQM850L 4384 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4385 Data Size: 335725 Bytes = 327 kB = 0 MB 4386 Load Address: 00000000 4387 Entry Point: 0000000c 4388 Verifying Checksum ... OK 4389 4390 4391Boot Linux: 4392----------- 4393 4394The "bootm" command is used to boot an application that is stored in 4395memory (RAM or Flash). In case of a Linux kernel image, the contents 4396of the "bootargs" environment variable is passed to the kernel as 4397parameters. You can check and modify this variable using the 4398"printenv" and "setenv" commands: 4399 4400 4401 => printenv bootargs 4402 bootargs=root=/dev/ram 4403 4404 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4405 4406 => printenv bootargs 4407 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4408 4409 => bootm 40020000 4410 ## Booting Linux kernel at 40020000 ... 4411 Image Name: 2.2.13 for NFS on TQM850L 4412 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4413 Data Size: 381681 Bytes = 372 kB = 0 MB 4414 Load Address: 00000000 4415 Entry Point: 0000000c 4416 Verifying Checksum ... OK 4417 Uncompressing Kernel Image ... OK 4418 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 4419 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4420 time_init: decrementer frequency = 187500000/60 4421 Calibrating delay loop... 49.77 BogoMIPS 4422 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4423 ... 4424 4425If you want to boot a Linux kernel with initial RAM disk, you pass 4426the memory addresses of both the kernel and the initrd image (PPBCOOT 4427format!) to the "bootm" command: 4428 4429 => imi 40100000 40200000 4430 4431 ## Checking Image at 40100000 ... 4432 Image Name: 2.2.13 for initrd on TQM850L 4433 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4434 Data Size: 335725 Bytes = 327 kB = 0 MB 4435 Load Address: 00000000 4436 Entry Point: 0000000c 4437 Verifying Checksum ... OK 4438 4439 ## Checking Image at 40200000 ... 4440 Image Name: Simple Ramdisk Image 4441 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4442 Data Size: 566530 Bytes = 553 kB = 0 MB 4443 Load Address: 00000000 4444 Entry Point: 00000000 4445 Verifying Checksum ... OK 4446 4447 => bootm 40100000 40200000 4448 ## Booting Linux kernel at 40100000 ... 4449 Image Name: 2.2.13 for initrd on TQM850L 4450 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4451 Data Size: 335725 Bytes = 327 kB = 0 MB 4452 Load Address: 00000000 4453 Entry Point: 0000000c 4454 Verifying Checksum ... OK 4455 Uncompressing Kernel Image ... OK 4456 ## Loading RAMDisk Image at 40200000 ... 4457 Image Name: Simple Ramdisk Image 4458 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4459 Data Size: 566530 Bytes = 553 kB = 0 MB 4460 Load Address: 00000000 4461 Entry Point: 00000000 4462 Verifying Checksum ... OK 4463 Loading Ramdisk ... OK 4464 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 4465 Boot arguments: root=/dev/ram 4466 time_init: decrementer frequency = 187500000/60 4467 Calibrating delay loop... 49.77 BogoMIPS 4468 ... 4469 RAMDISK: Compressed image found at block 0 4470 VFS: Mounted root (ext2 filesystem). 4471 4472 bash# 4473 4474Boot Linux and pass a flat device tree: 4475----------- 4476 4477First, U-Boot must be compiled with the appropriate defines. See the section 4478titled "Linux Kernel Interface" above for a more in depth explanation. The 4479following is an example of how to start a kernel and pass an updated 4480flat device tree: 4481 4482=> print oftaddr 4483oftaddr=0x300000 4484=> print oft 4485oft=oftrees/mpc8540ads.dtb 4486=> tftp $oftaddr $oft 4487Speed: 1000, full duplex 4488Using TSEC0 device 4489TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4490Filename 'oftrees/mpc8540ads.dtb'. 4491Load address: 0x300000 4492Loading: # 4493done 4494Bytes transferred = 4106 (100a hex) 4495=> tftp $loadaddr $bootfile 4496Speed: 1000, full duplex 4497Using TSEC0 device 4498TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4499Filename 'uImage'. 4500Load address: 0x200000 4501Loading:############ 4502done 4503Bytes transferred = 1029407 (fb51f hex) 4504=> print loadaddr 4505loadaddr=200000 4506=> print oftaddr 4507oftaddr=0x300000 4508=> bootm $loadaddr - $oftaddr 4509## Booting image at 00200000 ... 4510 Image Name: Linux-2.6.17-dirty 4511 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4512 Data Size: 1029343 Bytes = 1005.2 kB 4513 Load Address: 00000000 4514 Entry Point: 00000000 4515 Verifying Checksum ... OK 4516 Uncompressing Kernel Image ... OK 4517Booting using flat device tree at 0x300000 4518Using MPC85xx ADS machine description 4519Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4520[snip] 4521 4522 4523More About U-Boot Image Types: 4524------------------------------ 4525 4526U-Boot supports the following image types: 4527 4528 "Standalone Programs" are directly runnable in the environment 4529 provided by U-Boot; it is expected that (if they behave 4530 well) you can continue to work in U-Boot after return from 4531 the Standalone Program. 4532 "OS Kernel Images" are usually images of some Embedded OS which 4533 will take over control completely. Usually these programs 4534 will install their own set of exception handlers, device 4535 drivers, set up the MMU, etc. - this means, that you cannot 4536 expect to re-enter U-Boot except by resetting the CPU. 4537 "RAMDisk Images" are more or less just data blocks, and their 4538 parameters (address, size) are passed to an OS kernel that is 4539 being started. 4540 "Multi-File Images" contain several images, typically an OS 4541 (Linux) kernel image and one or more data images like 4542 RAMDisks. This construct is useful for instance when you want 4543 to boot over the network using BOOTP etc., where the boot 4544 server provides just a single image file, but you want to get 4545 for instance an OS kernel and a RAMDisk image. 4546 4547 "Multi-File Images" start with a list of image sizes, each 4548 image size (in bytes) specified by an "uint32_t" in network 4549 byte order. This list is terminated by an "(uint32_t)0". 4550 Immediately after the terminating 0 follow the images, one by 4551 one, all aligned on "uint32_t" boundaries (size rounded up to 4552 a multiple of 4 bytes). 4553 4554 "Firmware Images" are binary images containing firmware (like 4555 U-Boot or FPGA images) which usually will be programmed to 4556 flash memory. 4557 4558 "Script files" are command sequences that will be executed by 4559 U-Boot's command interpreter; this feature is especially 4560 useful when you configure U-Boot to use a real shell (hush) 4561 as command interpreter. 4562 4563Booting the Linux zImage: 4564------------------------- 4565 4566On some platforms, it's possible to boot Linux zImage. This is done 4567using the "bootz" command. The syntax of "bootz" command is the same 4568as the syntax of "bootm" command. 4569 4570Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4571kernel with raw initrd images. The syntax is slightly different, the 4572address of the initrd must be augmented by it's size, in the following 4573format: "<initrd addres>:<initrd size>". 4574 4575 4576Standalone HOWTO: 4577================= 4578 4579One of the features of U-Boot is that you can dynamically load and 4580run "standalone" applications, which can use some resources of 4581U-Boot like console I/O functions or interrupt services. 4582 4583Two simple examples are included with the sources: 4584 4585"Hello World" Demo: 4586------------------- 4587 4588'examples/hello_world.c' contains a small "Hello World" Demo 4589application; it is automatically compiled when you build U-Boot. 4590It's configured to run at address 0x00040004, so you can play with it 4591like that: 4592 4593 => loads 4594 ## Ready for S-Record download ... 4595 ~>examples/hello_world.srec 4596 1 2 3 4 5 6 7 8 9 10 11 ... 4597 [file transfer complete] 4598 [connected] 4599 ## Start Addr = 0x00040004 4600 4601 => go 40004 Hello World! This is a test. 4602 ## Starting application at 0x00040004 ... 4603 Hello World 4604 argc = 7 4605 argv[0] = "40004" 4606 argv[1] = "Hello" 4607 argv[2] = "World!" 4608 argv[3] = "This" 4609 argv[4] = "is" 4610 argv[5] = "a" 4611 argv[6] = "test." 4612 argv[7] = "<NULL>" 4613 Hit any key to exit ... 4614 4615 ## Application terminated, rc = 0x0 4616 4617Another example, which demonstrates how to register a CPM interrupt 4618handler with the U-Boot code, can be found in 'examples/timer.c'. 4619Here, a CPM timer is set up to generate an interrupt every second. 4620The interrupt service routine is trivial, just printing a '.' 4621character, but this is just a demo program. The application can be 4622controlled by the following keys: 4623 4624 ? - print current values og the CPM Timer registers 4625 b - enable interrupts and start timer 4626 e - stop timer and disable interrupts 4627 q - quit application 4628 4629 => loads 4630 ## Ready for S-Record download ... 4631 ~>examples/timer.srec 4632 1 2 3 4 5 6 7 8 9 10 11 ... 4633 [file transfer complete] 4634 [connected] 4635 ## Start Addr = 0x00040004 4636 4637 => go 40004 4638 ## Starting application at 0x00040004 ... 4639 TIMERS=0xfff00980 4640 Using timer 1 4641 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4642 4643Hit 'b': 4644 [q, b, e, ?] Set interval 1000000 us 4645 Enabling timer 4646Hit '?': 4647 [q, b, e, ?] ........ 4648 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4649Hit '?': 4650 [q, b, e, ?] . 4651 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4652Hit '?': 4653 [q, b, e, ?] . 4654 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4655Hit '?': 4656 [q, b, e, ?] . 4657 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4658Hit 'e': 4659 [q, b, e, ?] ...Stopping timer 4660Hit 'q': 4661 [q, b, e, ?] ## Application terminated, rc = 0x0 4662 4663 4664Minicom warning: 4665================ 4666 4667Over time, many people have reported problems when trying to use the 4668"minicom" terminal emulation program for serial download. I (wd) 4669consider minicom to be broken, and recommend not to use it. Under 4670Unix, I recommend to use C-Kermit for general purpose use (and 4671especially for kermit binary protocol download ("loadb" command), and 4672use "cu" for S-Record download ("loads" command). See 4673http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4674for help with kermit. 4675 4676 4677Nevertheless, if you absolutely want to use it try adding this 4678configuration to your "File transfer protocols" section: 4679 4680 Name Program Name U/D FullScr IO-Red. Multi 4681 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4682 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4683 4684 4685NetBSD Notes: 4686============= 4687 4688Starting at version 0.9.2, U-Boot supports NetBSD both as host 4689(build U-Boot) and target system (boots NetBSD/mpc8xx). 4690 4691Building requires a cross environment; it is known to work on 4692NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4693need gmake since the Makefiles are not compatible with BSD make). 4694Note that the cross-powerpc package does not install include files; 4695attempting to build U-Boot will fail because <machine/ansi.h> is 4696missing. This file has to be installed and patched manually: 4697 4698 # cd /usr/pkg/cross/powerpc-netbsd/include 4699 # mkdir powerpc 4700 # ln -s powerpc machine 4701 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4702 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4703 4704Native builds *don't* work due to incompatibilities between native 4705and U-Boot include files. 4706 4707Booting assumes that (the first part of) the image booted is a 4708stage-2 loader which in turn loads and then invokes the kernel 4709proper. Loader sources will eventually appear in the NetBSD source 4710tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4711meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4712 4713 4714Implementation Internals: 4715========================= 4716 4717The following is not intended to be a complete description of every 4718implementation detail. However, it should help to understand the 4719inner workings of U-Boot and make it easier to port it to custom 4720hardware. 4721 4722 4723Initial Stack, Global Data: 4724--------------------------- 4725 4726The implementation of U-Boot is complicated by the fact that U-Boot 4727starts running out of ROM (flash memory), usually without access to 4728system RAM (because the memory controller is not initialized yet). 4729This means that we don't have writable Data or BSS segments, and BSS 4730is not initialized as zero. To be able to get a C environment working 4731at all, we have to allocate at least a minimal stack. Implementation 4732options for this are defined and restricted by the CPU used: Some CPU 4733models provide on-chip memory (like the IMMR area on MPC8xx and 4734MPC826x processors), on others (parts of) the data cache can be 4735locked as (mis-) used as memory, etc. 4736 4737 Chris Hallinan posted a good summary of these issues to the 4738 U-Boot mailing list: 4739 4740 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4741 From: "Chris Hallinan" <clh@net1plus.com> 4742 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4743 ... 4744 4745 Correct me if I'm wrong, folks, but the way I understand it 4746 is this: Using DCACHE as initial RAM for Stack, etc, does not 4747 require any physical RAM backing up the cache. The cleverness 4748 is that the cache is being used as a temporary supply of 4749 necessary storage before the SDRAM controller is setup. It's 4750 beyond the scope of this list to explain the details, but you 4751 can see how this works by studying the cache architecture and 4752 operation in the architecture and processor-specific manuals. 4753 4754 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4755 is another option for the system designer to use as an 4756 initial stack/RAM area prior to SDRAM being available. Either 4757 option should work for you. Using CS 4 should be fine if your 4758 board designers haven't used it for something that would 4759 cause you grief during the initial boot! It is frequently not 4760 used. 4761 4762 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4763 with your processor/board/system design. The default value 4764 you will find in any recent u-boot distribution in 4765 walnut.h should work for you. I'd set it to a value larger 4766 than your SDRAM module. If you have a 64MB SDRAM module, set 4767 it above 400_0000. Just make sure your board has no resources 4768 that are supposed to respond to that address! That code in 4769 start.S has been around a while and should work as is when 4770 you get the config right. 4771 4772 -Chris Hallinan 4773 DS4.COM, Inc. 4774 4775It is essential to remember this, since it has some impact on the C 4776code for the initialization procedures: 4777 4778* Initialized global data (data segment) is read-only. Do not attempt 4779 to write it. 4780 4781* Do not use any uninitialized global data (or implicitly initialized 4782 as zero data - BSS segment) at all - this is undefined, initiali- 4783 zation is performed later (when relocating to RAM). 4784 4785* Stack space is very limited. Avoid big data buffers or things like 4786 that. 4787 4788Having only the stack as writable memory limits means we cannot use 4789normal global data to share information between the code. But it 4790turned out that the implementation of U-Boot can be greatly 4791simplified by making a global data structure (gd_t) available to all 4792functions. We could pass a pointer to this data as argument to _all_ 4793functions, but this would bloat the code. Instead we use a feature of 4794the GCC compiler (Global Register Variables) to share the data: we 4795place a pointer (gd) to the global data into a register which we 4796reserve for this purpose. 4797 4798When choosing a register for such a purpose we are restricted by the 4799relevant (E)ABI specifications for the current architecture, and by 4800GCC's implementation. 4801 4802For PowerPC, the following registers have specific use: 4803 R1: stack pointer 4804 R2: reserved for system use 4805 R3-R4: parameter passing and return values 4806 R5-R10: parameter passing 4807 R13: small data area pointer 4808 R30: GOT pointer 4809 R31: frame pointer 4810 4811 (U-Boot also uses R12 as internal GOT pointer. r12 4812 is a volatile register so r12 needs to be reset when 4813 going back and forth between asm and C) 4814 4815 ==> U-Boot will use R2 to hold a pointer to the global data 4816 4817 Note: on PPC, we could use a static initializer (since the 4818 address of the global data structure is known at compile time), 4819 but it turned out that reserving a register results in somewhat 4820 smaller code - although the code savings are not that big (on 4821 average for all boards 752 bytes for the whole U-Boot image, 4822 624 text + 127 data). 4823 4824On ARM, the following registers are used: 4825 4826 R0: function argument word/integer result 4827 R1-R3: function argument word 4828 R9: platform specific 4829 R10: stack limit (used only if stack checking is enabled) 4830 R11: argument (frame) pointer 4831 R12: temporary workspace 4832 R13: stack pointer 4833 R14: link register 4834 R15: program counter 4835 4836 ==> U-Boot will use R9 to hold a pointer to the global data 4837 4838 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4839 4840On Nios II, the ABI is documented here: 4841 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4842 4843 ==> U-Boot will use gp to hold a pointer to the global data 4844 4845 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4846 to access small data sections, so gp is free. 4847 4848On NDS32, the following registers are used: 4849 4850 R0-R1: argument/return 4851 R2-R5: argument 4852 R15: temporary register for assembler 4853 R16: trampoline register 4854 R28: frame pointer (FP) 4855 R29: global pointer (GP) 4856 R30: link register (LP) 4857 R31: stack pointer (SP) 4858 PC: program counter (PC) 4859 4860 ==> U-Boot will use R10 to hold a pointer to the global data 4861 4862NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4863or current versions of GCC may "optimize" the code too much. 4864 4865On RISC-V, the following registers are used: 4866 4867 x0: hard-wired zero (zero) 4868 x1: return address (ra) 4869 x2: stack pointer (sp) 4870 x3: global pointer (gp) 4871 x4: thread pointer (tp) 4872 x5: link register (t0) 4873 x8: frame pointer (fp) 4874 x10-x11: arguments/return values (a0-1) 4875 x12-x17: arguments (a2-7) 4876 x28-31: temporaries (t3-6) 4877 pc: program counter (pc) 4878 4879 ==> U-Boot will use gp to hold a pointer to the global data 4880 4881Memory Management: 4882------------------ 4883 4884U-Boot runs in system state and uses physical addresses, i.e. the 4885MMU is not used either for address mapping nor for memory protection. 4886 4887The available memory is mapped to fixed addresses using the memory 4888controller. In this process, a contiguous block is formed for each 4889memory type (Flash, SDRAM, SRAM), even when it consists of several 4890physical memory banks. 4891 4892U-Boot is installed in the first 128 kB of the first Flash bank (on 4893TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4894booting and sizing and initializing DRAM, the code relocates itself 4895to the upper end of DRAM. Immediately below the U-Boot code some 4896memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4897configuration setting]. Below that, a structure with global Board 4898Info data is placed, followed by the stack (growing downward). 4899 4900Additionally, some exception handler code is copied to the low 8 kB 4901of DRAM (0x00000000 ... 0x00001FFF). 4902 4903So a typical memory configuration with 16 MB of DRAM could look like 4904this: 4905 4906 0x0000 0000 Exception Vector code 4907 : 4908 0x0000 1FFF 4909 0x0000 2000 Free for Application Use 4910 : 4911 : 4912 4913 : 4914 : 4915 0x00FB FF20 Monitor Stack (Growing downward) 4916 0x00FB FFAC Board Info Data and permanent copy of global data 4917 0x00FC 0000 Malloc Arena 4918 : 4919 0x00FD FFFF 4920 0x00FE 0000 RAM Copy of Monitor Code 4921 ... eventually: LCD or video framebuffer 4922 ... eventually: pRAM (Protected RAM - unchanged by reset) 4923 0x00FF FFFF [End of RAM] 4924 4925 4926System Initialization: 4927---------------------- 4928 4929In the reset configuration, U-Boot starts at the reset entry point 4930(on most PowerPC systems at address 0x00000100). Because of the reset 4931configuration for CS0# this is a mirror of the on board Flash memory. 4932To be able to re-map memory U-Boot then jumps to its link address. 4933To be able to implement the initialization code in C, a (small!) 4934initial stack is set up in the internal Dual Ported RAM (in case CPUs 4935which provide such a feature like), or in a locked part of the data 4936cache. After that, U-Boot initializes the CPU core, the caches and 4937the SIU. 4938 4939Next, all (potentially) available memory banks are mapped using a 4940preliminary mapping. For example, we put them on 512 MB boundaries 4941(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4942on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4943programmed for SDRAM access. Using the temporary configuration, a 4944simple memory test is run that determines the size of the SDRAM 4945banks. 4946 4947When there is more than one SDRAM bank, and the banks are of 4948different size, the largest is mapped first. For equal size, the first 4949bank (CS2#) is mapped first. The first mapping is always for address 49500x00000000, with any additional banks following immediately to create 4951contiguous memory starting from 0. 4952 4953Then, the monitor installs itself at the upper end of the SDRAM area 4954and allocates memory for use by malloc() and for the global Board 4955Info data; also, the exception vector code is copied to the low RAM 4956pages, and the final stack is set up. 4957 4958Only after this relocation will you have a "normal" C environment; 4959until that you are restricted in several ways, mostly because you are 4960running from ROM, and because the code will have to be relocated to a 4961new address in RAM. 4962 4963 4964U-Boot Porting Guide: 4965---------------------- 4966 4967[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4968list, October 2002] 4969 4970 4971int main(int argc, char *argv[]) 4972{ 4973 sighandler_t no_more_time; 4974 4975 signal(SIGALRM, no_more_time); 4976 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4977 4978 if (available_money > available_manpower) { 4979 Pay consultant to port U-Boot; 4980 return 0; 4981 } 4982 4983 Download latest U-Boot source; 4984 4985 Subscribe to u-boot mailing list; 4986 4987 if (clueless) 4988 email("Hi, I am new to U-Boot, how do I get started?"); 4989 4990 while (learning) { 4991 Read the README file in the top level directory; 4992 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4993 Read applicable doc/*.README; 4994 Read the source, Luke; 4995 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4996 } 4997 4998 if (available_money > toLocalCurrency ($2500)) 4999 Buy a BDI3000; 5000 else 5001 Add a lot of aggravation and time; 5002 5003 if (a similar board exists) { /* hopefully... */ 5004 cp -a board/<similar> board/<myboard> 5005 cp include/configs/<similar>.h include/configs/<myboard>.h 5006 } else { 5007 Create your own board support subdirectory; 5008 Create your own board include/configs/<myboard>.h file; 5009 } 5010 Edit new board/<myboard> files 5011 Edit new include/configs/<myboard>.h 5012 5013 while (!accepted) { 5014 while (!running) { 5015 do { 5016 Add / modify source code; 5017 } until (compiles); 5018 Debug; 5019 if (clueless) 5020 email("Hi, I am having problems..."); 5021 } 5022 Send patch file to the U-Boot email list; 5023 if (reasonable critiques) 5024 Incorporate improvements from email list code review; 5025 else 5026 Defend code as written; 5027 } 5028 5029 return 0; 5030} 5031 5032void no_more_time (int sig) 5033{ 5034 hire_a_guru(); 5035} 5036 5037 5038Coding Standards: 5039----------------- 5040 5041All contributions to U-Boot should conform to the Linux kernel 5042coding style; see the kernel coding style guide at 5043https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 5044script "scripts/Lindent" in your Linux kernel source directory. 5045 5046Source files originating from a different project (for example the 5047MTD subsystem) are generally exempt from these guidelines and are not 5048reformatted to ease subsequent migration to newer versions of those 5049sources. 5050 5051Please note that U-Boot is implemented in C (and to some small parts in 5052Assembler); no C++ is used, so please do not use C++ style comments (//) 5053in your code. 5054 5055Please also stick to the following formatting rules: 5056- remove any trailing white space 5057- use TAB characters for indentation and vertical alignment, not spaces 5058- make sure NOT to use DOS '\r\n' line feeds 5059- do not add more than 2 consecutive empty lines to source files 5060- do not add trailing empty lines to source files 5061 5062Submissions which do not conform to the standards may be returned 5063with a request to reformat the changes. 5064 5065 5066Submitting Patches: 5067------------------- 5068 5069Since the number of patches for U-Boot is growing, we need to 5070establish some rules. Submissions which do not conform to these rules 5071may be rejected, even when they contain important and valuable stuff. 5072 5073Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5074 5075Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5076see https://lists.denx.de/listinfo/u-boot 5077 5078When you send a patch, please include the following information with 5079it: 5080 5081* For bug fixes: a description of the bug and how your patch fixes 5082 this bug. Please try to include a way of demonstrating that the 5083 patch actually fixes something. 5084 5085* For new features: a description of the feature and your 5086 implementation. 5087 5088* A CHANGELOG entry as plaintext (separate from the patch) 5089 5090* For major contributions, add a MAINTAINERS file with your 5091 information and associated file and directory references. 5092 5093* When you add support for a new board, don't forget to add a 5094 maintainer e-mail address to the boards.cfg file, too. 5095 5096* If your patch adds new configuration options, don't forget to 5097 document these in the README file. 5098 5099* The patch itself. If you are using git (which is *strongly* 5100 recommended) you can easily generate the patch using the 5101 "git format-patch". If you then use "git send-email" to send it to 5102 the U-Boot mailing list, you will avoid most of the common problems 5103 with some other mail clients. 5104 5105 If you cannot use git, use "diff -purN OLD NEW". If your version of 5106 diff does not support these options, then get the latest version of 5107 GNU diff. 5108 5109 The current directory when running this command shall be the parent 5110 directory of the U-Boot source tree (i. e. please make sure that 5111 your patch includes sufficient directory information for the 5112 affected files). 5113 5114 We prefer patches as plain text. MIME attachments are discouraged, 5115 and compressed attachments must not be used. 5116 5117* If one logical set of modifications affects or creates several 5118 files, all these changes shall be submitted in a SINGLE patch file. 5119 5120* Changesets that contain different, unrelated modifications shall be 5121 submitted as SEPARATE patches, one patch per changeset. 5122 5123 5124Notes: 5125 5126* Before sending the patch, run the buildman script on your patched 5127 source tree and make sure that no errors or warnings are reported 5128 for any of the boards. 5129 5130* Keep your modifications to the necessary minimum: A patch 5131 containing several unrelated changes or arbitrary reformats will be 5132 returned with a request to re-formatting / split it. 5133 5134* If you modify existing code, make sure that your new code does not 5135 add to the memory footprint of the code ;-) Small is beautiful! 5136 When adding new features, these should compile conditionally only 5137 (using #ifdef), and the resulting code with the new feature 5138 disabled must not need more memory than the old code without your 5139 modification. 5140 5141* Remember that there is a size limit of 100 kB per message on the 5142 u-boot mailing list. Bigger patches will be moderated. If they are 5143 reasonable and not too big, they will be acknowledged. But patches 5144 bigger than the size limit should be avoided. 5145