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- Real-Time Clock: 816 817 When CONFIG_CMD_DATE is selected, the type of the RTC 818 has to be selected, too. Define exactly one of the 819 following options: 820 821 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 822 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 823 CONFIG_RTC_MC146818 - use MC146818 RTC 824 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 825 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 826 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 827 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 828 CONFIG_RTC_DS164x - use Dallas DS164x RTC 829 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 830 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 831 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 832 CONFIG_SYS_RV3029_TCR - enable trickle charger on 833 RV3029 RTC. 834 835 Note that if the RTC uses I2C, then the I2C interface 836 must also be configured. See I2C Support, below. 837 838- GPIO Support: 839 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 840 841 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 842 chip-ngpio pairs that tell the PCA953X driver the number of 843 pins supported by a particular chip. 844 845 Note that if the GPIO device uses I2C, then the I2C interface 846 must also be configured. See I2C Support, below. 847 848- I/O tracing: 849 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 850 accesses and can checksum them or write a list of them out 851 to memory. See the 'iotrace' command for details. This is 852 useful for testing device drivers since it can confirm that 853 the driver behaves the same way before and after a code 854 change. Currently this is supported on sandbox and arm. To 855 add support for your architecture, add '#include <iotrace.h>' 856 to the bottom of arch/<arch>/include/asm/io.h and test. 857 858 Example output from the 'iotrace stats' command is below. 859 Note that if the trace buffer is exhausted, the checksum will 860 still continue to operate. 861 862 iotrace is enabled 863 Start: 10000000 (buffer start address) 864 Size: 00010000 (buffer size) 865 Offset: 00000120 (current buffer offset) 866 Output: 10000120 (start + offset) 867 Count: 00000018 (number of trace records) 868 CRC32: 9526fb66 (CRC32 of all trace records) 869 870- Timestamp Support: 871 872 When CONFIG_TIMESTAMP is selected, the timestamp 873 (date and time) of an image is printed by image 874 commands like bootm or iminfo. This option is 875 automatically enabled when you select CONFIG_CMD_DATE . 876 877- Partition Labels (disklabels) Supported: 878 Zero or more of the following: 879 CONFIG_MAC_PARTITION Apple's MacOS partition table. 880 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 881 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 882 bootloader. Note 2TB partition limit; see 883 disk/part_efi.c 884 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 885 886 If IDE or SCSI support is enabled (CONFIG_IDE or 887 CONFIG_SCSI) you must configure support for at 888 least one non-MTD partition type as well. 889 890- IDE Reset method: 891 CONFIG_IDE_RESET_ROUTINE - this is defined in several 892 board configurations files but used nowhere! 893 894 CONFIG_IDE_RESET - is this is defined, IDE Reset will 895 be performed by calling the function 896 ide_set_reset(int reset) 897 which has to be defined in a board specific file 898 899- ATAPI Support: 900 CONFIG_ATAPI 901 902 Set this to enable ATAPI support. 903 904- LBA48 Support 905 CONFIG_LBA48 906 907 Set this to enable support for disks larger than 137GB 908 Also look at CONFIG_SYS_64BIT_LBA. 909 Whithout these , LBA48 support uses 32bit variables and will 'only' 910 support disks up to 2.1TB. 911 912 CONFIG_SYS_64BIT_LBA: 913 When enabled, makes the IDE subsystem use 64bit sector addresses. 914 Default is 32bit. 915 916- SCSI Support: 917 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 918 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 919 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 920 maximum numbers of LUNs, SCSI ID's and target 921 devices. 922 923 The environment variable 'scsidevs' is set to the number of 924 SCSI devices found during the last scan. 925 926- NETWORK Support (PCI): 927 CONFIG_E1000 928 Support for Intel 8254x/8257x gigabit chips. 929 930 CONFIG_E1000_SPI 931 Utility code for direct access to the SPI bus on Intel 8257x. 932 This does not do anything useful unless you set at least one 933 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 934 935 CONFIG_E1000_SPI_GENERIC 936 Allow generic access to the SPI bus on the Intel 8257x, for 937 example with the "sspi" command. 938 939 CONFIG_EEPRO100 940 Support for Intel 82557/82559/82559ER chips. 941 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 942 write routine for first time initialisation. 943 944 CONFIG_TULIP 945 Support for Digital 2114x chips. 946 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 947 modem chip initialisation (KS8761/QS6611). 948 949 CONFIG_NATSEMI 950 Support for National dp83815 chips. 951 952 CONFIG_NS8382X 953 Support for National dp8382[01] gigabit chips. 954 955- NETWORK Support (other): 956 957 CONFIG_DRIVER_AT91EMAC 958 Support for AT91RM9200 EMAC. 959 960 CONFIG_RMII 961 Define this to use reduced MII inteface 962 963 CONFIG_DRIVER_AT91EMAC_QUIET 964 If this defined, the driver is quiet. 965 The driver doen't show link status messages. 966 967 CONFIG_CALXEDA_XGMAC 968 Support for the Calxeda XGMAC device 969 970 CONFIG_LAN91C96 971 Support for SMSC's LAN91C96 chips. 972 973 CONFIG_LAN91C96_USE_32_BIT 974 Define this to enable 32 bit addressing 975 976 CONFIG_SMC91111 977 Support for SMSC's LAN91C111 chip 978 979 CONFIG_SMC91111_BASE 980 Define this to hold the physical address 981 of the device (I/O space) 982 983 CONFIG_SMC_USE_32_BIT 984 Define this if data bus is 32 bits 985 986 CONFIG_SMC_USE_IOFUNCS 987 Define this to use i/o functions instead of macros 988 (some hardware wont work with macros) 989 990 CONFIG_DRIVER_TI_EMAC 991 Support for davinci emac 992 993 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 994 Define this if you have more then 3 PHYs. 995 996 CONFIG_FTGMAC100 997 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 998 999 CONFIG_FTGMAC100_EGIGA 1000 Define this to use GE link update with gigabit PHY. 1001 Define this if FTGMAC100 is connected to gigabit PHY. 1002 If your system has 10/100 PHY only, it might not occur 1003 wrong behavior. Because PHY usually return timeout or 1004 useless data when polling gigabit status and gigabit 1005 control registers. This behavior won't affect the 1006 correctnessof 10/100 link speed update. 1007 1008 CONFIG_SH_ETHER 1009 Support for Renesas on-chip Ethernet controller 1010 1011 CONFIG_SH_ETHER_USE_PORT 1012 Define the number of ports to be used 1013 1014 CONFIG_SH_ETHER_PHY_ADDR 1015 Define the ETH PHY's address 1016 1017 CONFIG_SH_ETHER_CACHE_WRITEBACK 1018 If this option is set, the driver enables cache flush. 1019 1020- PWM Support: 1021 CONFIG_PWM_IMX 1022 Support for PWM module on the imx6. 1023 1024- TPM Support: 1025 CONFIG_TPM 1026 Support TPM devices. 1027 1028 CONFIG_TPM_TIS_INFINEON 1029 Support for Infineon i2c bus TPM devices. Only one device 1030 per system is supported at this time. 1031 1032 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1033 Define the burst count bytes upper limit 1034 1035 CONFIG_TPM_ST33ZP24 1036 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1037 1038 CONFIG_TPM_ST33ZP24_I2C 1039 Support for STMicroelectronics ST33ZP24 I2C devices. 1040 Requires TPM_ST33ZP24 and I2C. 1041 1042 CONFIG_TPM_ST33ZP24_SPI 1043 Support for STMicroelectronics ST33ZP24 SPI devices. 1044 Requires TPM_ST33ZP24 and SPI. 1045 1046 CONFIG_TPM_ATMEL_TWI 1047 Support for Atmel TWI TPM device. Requires I2C support. 1048 1049 CONFIG_TPM_TIS_LPC 1050 Support for generic parallel port TPM devices. Only one device 1051 per system is supported at this time. 1052 1053 CONFIG_TPM_TIS_BASE_ADDRESS 1054 Base address where the generic TPM device is mapped 1055 to. Contemporary x86 systems usually map it at 1056 0xfed40000. 1057 1058 CONFIG_TPM 1059 Define this to enable the TPM support library which provides 1060 functional interfaces to some TPM commands. 1061 Requires support for a TPM device. 1062 1063 CONFIG_TPM_AUTH_SESSIONS 1064 Define this to enable authorized functions in the TPM library. 1065 Requires CONFIG_TPM and CONFIG_SHA1. 1066 1067- USB Support: 1068 At the moment only the UHCI host controller is 1069 supported (PIP405, MIP405); define 1070 CONFIG_USB_UHCI to enable it. 1071 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1072 and define CONFIG_USB_STORAGE to enable the USB 1073 storage devices. 1074 Note: 1075 Supported are USB Keyboards and USB Floppy drives 1076 (TEAC FD-05PUB). 1077 1078 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1079 txfilltuning field in the EHCI controller on reset. 1080 1081 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1082 HW module registers. 1083 1084- USB Device: 1085 Define the below if you wish to use the USB console. 1086 Once firmware is rebuilt from a serial console issue the 1087 command "setenv stdin usbtty; setenv stdout usbtty" and 1088 attach your USB cable. The Unix command "dmesg" should print 1089 it has found a new device. The environment variable usbtty 1090 can be set to gserial or cdc_acm to enable your device to 1091 appear to a USB host as a Linux gserial device or a 1092 Common Device Class Abstract Control Model serial device. 1093 If you select usbtty = gserial you should be able to enumerate 1094 a Linux host by 1095 # modprobe usbserial vendor=0xVendorID product=0xProductID 1096 else if using cdc_acm, simply setting the environment 1097 variable usbtty to be cdc_acm should suffice. The following 1098 might be defined in YourBoardName.h 1099 1100 CONFIG_USB_DEVICE 1101 Define this to build a UDC device 1102 1103 CONFIG_USB_TTY 1104 Define this to have a tty type of device available to 1105 talk to the UDC device 1106 1107 CONFIG_USBD_HS 1108 Define this to enable the high speed support for usb 1109 device and usbtty. If this feature is enabled, a routine 1110 int is_usbd_high_speed(void) 1111 also needs to be defined by the driver to dynamically poll 1112 whether the enumeration has succeded at high speed or full 1113 speed. 1114 1115 CONFIG_SYS_CONSOLE_IS_IN_ENV 1116 Define this if you want stdin, stdout &/or stderr to 1117 be set to usbtty. 1118 1119 If you have a USB-IF assigned VendorID then you may wish to 1120 define your own vendor specific values either in BoardName.h 1121 or directly in usbd_vendor_info.h. If you don't define 1122 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1123 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1124 should pretend to be a Linux device to it's target host. 1125 1126 CONFIG_USBD_MANUFACTURER 1127 Define this string as the name of your company for 1128 - CONFIG_USBD_MANUFACTURER "my company" 1129 1130 CONFIG_USBD_PRODUCT_NAME 1131 Define this string as the name of your product 1132 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1133 1134 CONFIG_USBD_VENDORID 1135 Define this as your assigned Vendor ID from the USB 1136 Implementors Forum. This *must* be a genuine Vendor ID 1137 to avoid polluting the USB namespace. 1138 - CONFIG_USBD_VENDORID 0xFFFF 1139 1140 CONFIG_USBD_PRODUCTID 1141 Define this as the unique Product ID 1142 for your device 1143 - CONFIG_USBD_PRODUCTID 0xFFFF 1144 1145- ULPI Layer Support: 1146 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1147 the generic ULPI layer. The generic layer accesses the ULPI PHY 1148 via the platform viewport, so you need both the genric layer and 1149 the viewport enabled. Currently only Chipidea/ARC based 1150 viewport is supported. 1151 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1152 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1153 If your ULPI phy needs a different reference clock than the 1154 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1155 the appropriate value in Hz. 1156 1157- MMC Support: 1158 The MMC controller on the Intel PXA is supported. To 1159 enable this define CONFIG_MMC. The MMC can be 1160 accessed from the boot prompt by mapping the device 1161 to physical memory similar to flash. Command line is 1162 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1163 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1164 1165 CONFIG_SH_MMCIF 1166 Support for Renesas on-chip MMCIF controller 1167 1168 CONFIG_SH_MMCIF_ADDR 1169 Define the base address of MMCIF registers 1170 1171 CONFIG_SH_MMCIF_CLK 1172 Define the clock frequency for MMCIF 1173 1174 CONFIG_SUPPORT_EMMC_BOOT 1175 Enable some additional features of the eMMC boot partitions. 1176 1177 CONFIG_SUPPORT_EMMC_RPMB 1178 Enable the commands for reading, writing and programming the 1179 key for the Replay Protection Memory Block partition in eMMC. 1180 1181- USB Device Firmware Update (DFU) class support: 1182 CONFIG_DFU_OVER_USB 1183 This enables the USB portion of the DFU USB class 1184 1185 CONFIG_DFU_MMC 1186 This enables support for exposing (e)MMC devices via DFU. 1187 1188 CONFIG_DFU_NAND 1189 This enables support for exposing NAND devices via DFU. 1190 1191 CONFIG_DFU_RAM 1192 This enables support for exposing RAM via DFU. 1193 Note: DFU spec refer to non-volatile memory usage, but 1194 allow usages beyond the scope of spec - here RAM usage, 1195 one that would help mostly the developer. 1196 1197 CONFIG_SYS_DFU_DATA_BUF_SIZE 1198 Dfu transfer uses a buffer before writing data to the 1199 raw storage device. Make the size (in bytes) of this buffer 1200 configurable. The size of this buffer is also configurable 1201 through the "dfu_bufsiz" environment variable. 1202 1203 CONFIG_SYS_DFU_MAX_FILE_SIZE 1204 When updating files rather than the raw storage device, 1205 we use a static buffer to copy the file into and then write 1206 the buffer once we've been given the whole file. Define 1207 this to the maximum filesize (in bytes) for the buffer. 1208 Default is 4 MiB if undefined. 1209 1210 DFU_DEFAULT_POLL_TIMEOUT 1211 Poll timeout [ms], is the timeout a device can send to the 1212 host. The host must wait for this timeout before sending 1213 a subsequent DFU_GET_STATUS request to the device. 1214 1215 DFU_MANIFEST_POLL_TIMEOUT 1216 Poll timeout [ms], which the device sends to the host when 1217 entering dfuMANIFEST state. Host waits this timeout, before 1218 sending again an USB request to the device. 1219 1220- Journaling Flash filesystem support: 1221 CONFIG_JFFS2_NAND 1222 Define these for a default partition on a NAND device 1223 1224 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1225 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1226 Define these for a default partition on a NOR device 1227 1228- Keyboard Support: 1229 See Kconfig help for available keyboard drivers. 1230 1231 CONFIG_KEYBOARD 1232 1233 Define this to enable a custom keyboard support. 1234 This simply calls drv_keyboard_init() which must be 1235 defined in your board-specific files. This option is deprecated 1236 and is only used by novena. For new boards, use driver model 1237 instead. 1238 1239- Video support: 1240 CONFIG_FSL_DIU_FB 1241 Enable the Freescale DIU video driver. Reference boards for 1242 SOCs that have a DIU should define this macro to enable DIU 1243 support, and should also define these other macros: 1244 1245 CONFIG_SYS_DIU_ADDR 1246 CONFIG_VIDEO 1247 CONFIG_CFB_CONSOLE 1248 CONFIG_VIDEO_SW_CURSOR 1249 CONFIG_VGA_AS_SINGLE_DEVICE 1250 CONFIG_VIDEO_LOGO 1251 CONFIG_VIDEO_BMP_LOGO 1252 1253 The DIU driver will look for the 'video-mode' environment 1254 variable, and if defined, enable the DIU as a console during 1255 boot. See the documentation file doc/README.video for a 1256 description of this variable. 1257 1258- LCD Support: CONFIG_LCD 1259 1260 Define this to enable LCD support (for output to LCD 1261 display); also select one of the supported displays 1262 by defining one of these: 1263 1264 CONFIG_ATMEL_LCD: 1265 1266 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1267 1268 CONFIG_NEC_NL6448AC33: 1269 1270 NEC NL6448AC33-18. Active, color, single scan. 1271 1272 CONFIG_NEC_NL6448BC20 1273 1274 NEC NL6448BC20-08. 6.5", 640x480. 1275 Active, color, single scan. 1276 1277 CONFIG_NEC_NL6448BC33_54 1278 1279 NEC NL6448BC33-54. 10.4", 640x480. 1280 Active, color, single scan. 1281 1282 CONFIG_SHARP_16x9 1283 1284 Sharp 320x240. Active, color, single scan. 1285 It isn't 16x9, and I am not sure what it is. 1286 1287 CONFIG_SHARP_LQ64D341 1288 1289 Sharp LQ64D341 display, 640x480. 1290 Active, color, single scan. 1291 1292 CONFIG_HLD1045 1293 1294 HLD1045 display, 640x480. 1295 Active, color, single scan. 1296 1297 CONFIG_OPTREX_BW 1298 1299 Optrex CBL50840-2 NF-FW 99 22 M5 1300 or 1301 Hitachi LMG6912RPFC-00T 1302 or 1303 Hitachi SP14Q002 1304 1305 320x240. Black & white. 1306 1307 CONFIG_LCD_ALIGNMENT 1308 1309 Normally the LCD is page-aligned (typically 4KB). If this is 1310 defined then the LCD will be aligned to this value instead. 1311 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1312 here, since it is cheaper to change data cache settings on 1313 a per-section basis. 1314 1315 1316 CONFIG_LCD_ROTATION 1317 1318 Sometimes, for example if the display is mounted in portrait 1319 mode or even if it's mounted landscape but rotated by 180degree, 1320 we need to rotate our content of the display relative to the 1321 framebuffer, so that user can read the messages which are 1322 printed out. 1323 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1324 initialized with a given rotation from "vl_rot" out of 1325 "vidinfo_t" which is provided by the board specific code. 1326 The value for vl_rot is coded as following (matching to 1327 fbcon=rotate:<n> linux-kernel commandline): 1328 0 = no rotation respectively 0 degree 1329 1 = 90 degree rotation 1330 2 = 180 degree rotation 1331 3 = 270 degree rotation 1332 1333 If CONFIG_LCD_ROTATION is not defined, the console will be 1334 initialized with 0degree rotation. 1335 1336 CONFIG_LCD_BMP_RLE8 1337 1338 Support drawing of RLE8-compressed bitmaps on the LCD. 1339 1340 CONFIG_I2C_EDID 1341 1342 Enables an 'i2c edid' command which can read EDID 1343 information over I2C from an attached LCD display. 1344 1345- Splash Screen Support: CONFIG_SPLASH_SCREEN 1346 1347 If this option is set, the environment is checked for 1348 a variable "splashimage". If found, the usual display 1349 of logo, copyright and system information on the LCD 1350 is suppressed and the BMP image at the address 1351 specified in "splashimage" is loaded instead. The 1352 console is redirected to the "nulldev", too. This 1353 allows for a "silent" boot where a splash screen is 1354 loaded very quickly after power-on. 1355 1356 CONFIG_SPLASHIMAGE_GUARD 1357 1358 If this option is set, then U-Boot will prevent the environment 1359 variable "splashimage" from being set to a problematic address 1360 (see doc/README.displaying-bmps). 1361 This option is useful for targets where, due to alignment 1362 restrictions, an improperly aligned BMP image will cause a data 1363 abort. If you think you will not have problems with unaligned 1364 accesses (for example because your toolchain prevents them) 1365 there is no need to set this option. 1366 1367 CONFIG_SPLASH_SCREEN_ALIGN 1368 1369 If this option is set the splash image can be freely positioned 1370 on the screen. Environment variable "splashpos" specifies the 1371 position as "x,y". If a positive number is given it is used as 1372 number of pixel from left/top. If a negative number is given it 1373 is used as number of pixel from right/bottom. You can also 1374 specify 'm' for centering the image. 1375 1376 Example: 1377 setenv splashpos m,m 1378 => image at center of screen 1379 1380 setenv splashpos 30,20 1381 => image at x = 30 and y = 20 1382 1383 setenv splashpos -10,m 1384 => vertically centered image 1385 at x = dspWidth - bmpWidth - 9 1386 1387- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1388 1389 If this option is set, additionally to standard BMP 1390 images, gzipped BMP images can be displayed via the 1391 splashscreen support or the bmp command. 1392 1393- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1394 1395 If this option is set, 8-bit RLE compressed BMP images 1396 can be displayed via the splashscreen support or the 1397 bmp command. 1398 1399- Compression support: 1400 CONFIG_GZIP 1401 1402 Enabled by default to support gzip compressed images. 1403 1404 CONFIG_BZIP2 1405 1406 If this option is set, support for bzip2 compressed 1407 images is included. If not, only uncompressed and gzip 1408 compressed images are supported. 1409 1410 NOTE: the bzip2 algorithm requires a lot of RAM, so 1411 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1412 be at least 4MB. 1413 1414- MII/PHY support: 1415 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1416 1417 The clock frequency of the MII bus 1418 1419 CONFIG_PHY_RESET_DELAY 1420 1421 Some PHY like Intel LXT971A need extra delay after 1422 reset before any MII register access is possible. 1423 For such PHY, set this option to the usec delay 1424 required. (minimum 300usec for LXT971A) 1425 1426 CONFIG_PHY_CMD_DELAY (ppc4xx) 1427 1428 Some PHY like Intel LXT971A need extra delay after 1429 command issued before MII status register can be read 1430 1431- IP address: 1432 CONFIG_IPADDR 1433 1434 Define a default value for the IP address to use for 1435 the default Ethernet interface, in case this is not 1436 determined through e.g. bootp. 1437 (Environment variable "ipaddr") 1438 1439- Server IP address: 1440 CONFIG_SERVERIP 1441 1442 Defines a default value for the IP address of a TFTP 1443 server to contact when using the "tftboot" command. 1444 (Environment variable "serverip") 1445 1446 CONFIG_KEEP_SERVERADDR 1447 1448 Keeps the server's MAC address, in the env 'serveraddr' 1449 for passing to bootargs (like Linux's netconsole option) 1450 1451- Gateway IP address: 1452 CONFIG_GATEWAYIP 1453 1454 Defines a default value for the IP address of the 1455 default router where packets to other networks are 1456 sent to. 1457 (Environment variable "gatewayip") 1458 1459- Subnet mask: 1460 CONFIG_NETMASK 1461 1462 Defines a default value for the subnet mask (or 1463 routing prefix) which is used to determine if an IP 1464 address belongs to the local subnet or needs to be 1465 forwarded through a router. 1466 (Environment variable "netmask") 1467 1468- Multicast TFTP Mode: 1469 CONFIG_MCAST_TFTP 1470 1471 Defines whether you want to support multicast TFTP as per 1472 rfc-2090; for example to work with atftp. Lets lots of targets 1473 tftp down the same boot image concurrently. Note: the Ethernet 1474 driver in use must provide a function: mcast() to join/leave a 1475 multicast group. 1476 1477- BOOTP Recovery Mode: 1478 CONFIG_BOOTP_RANDOM_DELAY 1479 1480 If you have many targets in a network that try to 1481 boot using BOOTP, you may want to avoid that all 1482 systems send out BOOTP requests at precisely the same 1483 moment (which would happen for instance at recovery 1484 from a power failure, when all systems will try to 1485 boot, thus flooding the BOOTP server. Defining 1486 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1487 inserted before sending out BOOTP requests. The 1488 following delays are inserted then: 1489 1490 1st BOOTP request: delay 0 ... 1 sec 1491 2nd BOOTP request: delay 0 ... 2 sec 1492 3rd BOOTP request: delay 0 ... 4 sec 1493 4th and following 1494 BOOTP requests: delay 0 ... 8 sec 1495 1496 CONFIG_BOOTP_ID_CACHE_SIZE 1497 1498 BOOTP packets are uniquely identified using a 32-bit ID. The 1499 server will copy the ID from client requests to responses and 1500 U-Boot will use this to determine if it is the destination of 1501 an incoming response. Some servers will check that addresses 1502 aren't in use before handing them out (usually using an ARP 1503 ping) and therefore take up to a few hundred milliseconds to 1504 respond. Network congestion may also influence the time it 1505 takes for a response to make it back to the client. If that 1506 time is too long, U-Boot will retransmit requests. In order 1507 to allow earlier responses to still be accepted after these 1508 retransmissions, U-Boot's BOOTP client keeps a small cache of 1509 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1510 cache. The default is to keep IDs for up to four outstanding 1511 requests. Increasing this will allow U-Boot to accept offers 1512 from a BOOTP client in networks with unusually high latency. 1513 1514- DHCP Advanced Options: 1515 You can fine tune the DHCP functionality by defining 1516 CONFIG_BOOTP_* symbols: 1517 1518 CONFIG_BOOTP_NISDOMAIN 1519 CONFIG_BOOTP_BOOTFILESIZE 1520 CONFIG_BOOTP_SEND_HOSTNAME 1521 CONFIG_BOOTP_NTPSERVER 1522 CONFIG_BOOTP_TIMEOFFSET 1523 CONFIG_BOOTP_VENDOREX 1524 CONFIG_BOOTP_MAY_FAIL 1525 1526 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1527 environment variable, not the BOOTP server. 1528 1529 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1530 after the configured retry count, the call will fail 1531 instead of starting over. This can be used to fail over 1532 to Link-local IP address configuration if the DHCP server 1533 is not available. 1534 1535 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1536 to do a dynamic update of a DNS server. To do this, they 1537 need the hostname of the DHCP requester. 1538 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1539 of the "hostname" environment variable is passed as 1540 option 12 to the DHCP server. 1541 1542 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1543 1544 A 32bit value in microseconds for a delay between 1545 receiving a "DHCP Offer" and sending the "DHCP Request". 1546 This fixes a problem with certain DHCP servers that don't 1547 respond 100% of the time to a "DHCP request". E.g. On an 1548 AT91RM9200 processor running at 180MHz, this delay needed 1549 to be *at least* 15,000 usec before a Windows Server 2003 1550 DHCP server would reply 100% of the time. I recommend at 1551 least 50,000 usec to be safe. The alternative is to hope 1552 that one of the retries will be successful but note that 1553 the DHCP timeout and retry process takes a longer than 1554 this delay. 1555 1556 - Link-local IP address negotiation: 1557 Negotiate with other link-local clients on the local network 1558 for an address that doesn't require explicit configuration. 1559 This is especially useful if a DHCP server cannot be guaranteed 1560 to exist in all environments that the device must operate. 1561 1562 See doc/README.link-local for more information. 1563 1564 - MAC address from environment variables 1565 1566 FDT_SEQ_MACADDR_FROM_ENV 1567 1568 Fix-up device tree with MAC addresses fetched sequentially from 1569 environment variables. This config work on assumption that 1570 non-usable ethernet node of device-tree are either not present 1571 or their status has been marked as "disabled". 1572 1573 - CDP Options: 1574 CONFIG_CDP_DEVICE_ID 1575 1576 The device id used in CDP trigger frames. 1577 1578 CONFIG_CDP_DEVICE_ID_PREFIX 1579 1580 A two character string which is prefixed to the MAC address 1581 of the device. 1582 1583 CONFIG_CDP_PORT_ID 1584 1585 A printf format string which contains the ascii name of 1586 the port. Normally is set to "eth%d" which sets 1587 eth0 for the first Ethernet, eth1 for the second etc. 1588 1589 CONFIG_CDP_CAPABILITIES 1590 1591 A 32bit integer which indicates the device capabilities; 1592 0x00000010 for a normal host which does not forwards. 1593 1594 CONFIG_CDP_VERSION 1595 1596 An ascii string containing the version of the software. 1597 1598 CONFIG_CDP_PLATFORM 1599 1600 An ascii string containing the name of the platform. 1601 1602 CONFIG_CDP_TRIGGER 1603 1604 A 32bit integer sent on the trigger. 1605 1606 CONFIG_CDP_POWER_CONSUMPTION 1607 1608 A 16bit integer containing the power consumption of the 1609 device in .1 of milliwatts. 1610 1611 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1612 1613 A byte containing the id of the VLAN. 1614 1615- Status LED: CONFIG_LED_STATUS 1616 1617 Several configurations allow to display the current 1618 status using a LED. For instance, the LED will blink 1619 fast while running U-Boot code, stop blinking as 1620 soon as a reply to a BOOTP request was received, and 1621 start blinking slow once the Linux kernel is running 1622 (supported by a status LED driver in the Linux 1623 kernel). Defining CONFIG_LED_STATUS enables this 1624 feature in U-Boot. 1625 1626 Additional options: 1627 1628 CONFIG_LED_STATUS_GPIO 1629 The status LED can be connected to a GPIO pin. 1630 In such cases, the gpio_led driver can be used as a 1631 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1632 to include the gpio_led driver in the U-Boot binary. 1633 1634 CONFIG_GPIO_LED_INVERTED_TABLE 1635 Some GPIO connected LEDs may have inverted polarity in which 1636 case the GPIO high value corresponds to LED off state and 1637 GPIO low value corresponds to LED on state. 1638 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1639 with a list of GPIO LEDs that have inverted polarity. 1640 1641- I2C Support: CONFIG_SYS_I2C 1642 1643 This enable the NEW i2c subsystem, and will allow you to use 1644 i2c commands at the u-boot command line (as long as you set 1645 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1646 based realtime clock chips or other i2c devices. See 1647 common/cmd_i2c.c for a description of the command line 1648 interface. 1649 1650 ported i2c driver to the new framework: 1651 - drivers/i2c/soft_i2c.c: 1652 - activate first bus with CONFIG_SYS_I2C_SOFT define 1653 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1654 for defining speed and slave address 1655 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1656 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1657 for defining speed and slave address 1658 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1659 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1660 for defining speed and slave address 1661 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1662 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1663 for defining speed and slave address 1664 1665 - drivers/i2c/fsl_i2c.c: 1666 - activate i2c driver with CONFIG_SYS_I2C_FSL 1667 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1668 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1669 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1670 bus. 1671 - If your board supports a second fsl i2c bus, define 1672 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1673 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1674 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1675 second bus. 1676 1677 - drivers/i2c/tegra_i2c.c: 1678 - activate this driver with CONFIG_SYS_I2C_TEGRA 1679 - This driver adds 4 i2c buses with a fix speed from 1680 100000 and the slave addr 0! 1681 1682 - drivers/i2c/ppc4xx_i2c.c 1683 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1684 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1685 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1686 1687 - drivers/i2c/i2c_mxc.c 1688 - activate this driver with CONFIG_SYS_I2C_MXC 1689 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1690 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1691 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1692 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1693 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1694 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1695 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1696 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1697 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1698 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1699 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1700 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1701 If those defines are not set, default value is 100000 1702 for speed, and 0 for slave. 1703 1704 - drivers/i2c/rcar_i2c.c: 1705 - activate this driver with CONFIG_SYS_I2C_RCAR 1706 - This driver adds 4 i2c buses 1707 1708 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1709 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1710 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1711 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1712 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1713 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1714 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1715 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1716 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1717 1718 - drivers/i2c/sh_i2c.c: 1719 - activate this driver with CONFIG_SYS_I2C_SH 1720 - This driver adds from 2 to 5 i2c buses 1721 1722 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1723 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1724 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1725 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1726 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1727 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1728 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1729 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1730 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1731 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1732 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1733 1734 - drivers/i2c/omap24xx_i2c.c 1735 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1736 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1737 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1738 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1739 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1740 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1741 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1742 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1743 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1744 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1745 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1746 1747 - drivers/i2c/zynq_i2c.c 1748 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1749 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1750 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1751 1752 - drivers/i2c/s3c24x0_i2c.c: 1753 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1754 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1755 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1756 with a fix speed from 100000 and the slave addr 0! 1757 1758 - drivers/i2c/ihs_i2c.c 1759 - activate this driver with CONFIG_SYS_I2C_IHS 1760 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1761 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1762 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1763 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1764 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1765 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1766 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1767 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1768 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1769 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1770 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1771 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1772 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1773 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1774 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1775 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1776 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1777 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1778 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1779 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1780 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1781 1782 additional defines: 1783 1784 CONFIG_SYS_NUM_I2C_BUSES 1785 Hold the number of i2c buses you want to use. 1786 1787 CONFIG_SYS_I2C_DIRECT_BUS 1788 define this, if you don't use i2c muxes on your hardware. 1789 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1790 omit this define. 1791 1792 CONFIG_SYS_I2C_MAX_HOPS 1793 define how many muxes are maximal consecutively connected 1794 on one i2c bus. If you not use i2c muxes, omit this 1795 define. 1796 1797 CONFIG_SYS_I2C_BUSES 1798 hold a list of buses you want to use, only used if 1799 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1800 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1801 CONFIG_SYS_NUM_I2C_BUSES = 9: 1802 1803 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1804 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1805 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1806 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1807 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1808 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1809 {1, {I2C_NULL_HOP}}, \ 1810 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1811 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1812 } 1813 1814 which defines 1815 bus 0 on adapter 0 without a mux 1816 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1817 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1818 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1819 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1820 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1821 bus 6 on adapter 1 without a mux 1822 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1823 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1824 1825 If you do not have i2c muxes on your board, omit this define. 1826 1827- Legacy I2C Support: 1828 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1829 then the following macros need to be defined (examples are 1830 from include/configs/lwmon.h): 1831 1832 I2C_INIT 1833 1834 (Optional). Any commands necessary to enable the I2C 1835 controller or configure ports. 1836 1837 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1838 1839 I2C_ACTIVE 1840 1841 The code necessary to make the I2C data line active 1842 (driven). If the data line is open collector, this 1843 define can be null. 1844 1845 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1846 1847 I2C_TRISTATE 1848 1849 The code necessary to make the I2C data line tri-stated 1850 (inactive). If the data line is open collector, this 1851 define can be null. 1852 1853 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1854 1855 I2C_READ 1856 1857 Code that returns true if the I2C data line is high, 1858 false if it is low. 1859 1860 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1861 1862 I2C_SDA(bit) 1863 1864 If <bit> is true, sets the I2C data line high. If it 1865 is false, it clears it (low). 1866 1867 eg: #define I2C_SDA(bit) \ 1868 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1869 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1870 1871 I2C_SCL(bit) 1872 1873 If <bit> is true, sets the I2C clock line high. If it 1874 is false, it clears it (low). 1875 1876 eg: #define I2C_SCL(bit) \ 1877 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1878 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1879 1880 I2C_DELAY 1881 1882 This delay is invoked four times per clock cycle so this 1883 controls the rate of data transfer. The data rate thus 1884 is 1 / (I2C_DELAY * 4). Often defined to be something 1885 like: 1886 1887 #define I2C_DELAY udelay(2) 1888 1889 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1890 1891 If your arch supports the generic GPIO framework (asm/gpio.h), 1892 then you may alternatively define the two GPIOs that are to be 1893 used as SCL / SDA. Any of the previous I2C_xxx macros will 1894 have GPIO-based defaults assigned to them as appropriate. 1895 1896 You should define these to the GPIO value as given directly to 1897 the generic GPIO functions. 1898 1899 CONFIG_SYS_I2C_INIT_BOARD 1900 1901 When a board is reset during an i2c bus transfer 1902 chips might think that the current transfer is still 1903 in progress. On some boards it is possible to access 1904 the i2c SCLK line directly, either by using the 1905 processor pin as a GPIO or by having a second pin 1906 connected to the bus. If this option is defined a 1907 custom i2c_init_board() routine in boards/xxx/board.c 1908 is run early in the boot sequence. 1909 1910 CONFIG_I2C_MULTI_BUS 1911 1912 This option allows the use of multiple I2C buses, each of which 1913 must have a controller. At any point in time, only one bus is 1914 active. To switch to a different bus, use the 'i2c dev' command. 1915 Note that bus numbering is zero-based. 1916 1917 CONFIG_SYS_I2C_NOPROBES 1918 1919 This option specifies a list of I2C devices that will be skipped 1920 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1921 is set, specify a list of bus-device pairs. Otherwise, specify 1922 a 1D array of device addresses 1923 1924 e.g. 1925 #undef CONFIG_I2C_MULTI_BUS 1926 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1927 1928 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1929 1930 #define CONFIG_I2C_MULTI_BUS 1931 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1932 1933 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1934 1935 CONFIG_SYS_SPD_BUS_NUM 1936 1937 If defined, then this indicates the I2C bus number for DDR SPD. 1938 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1939 1940 CONFIG_SYS_RTC_BUS_NUM 1941 1942 If defined, then this indicates the I2C bus number for the RTC. 1943 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1944 1945 CONFIG_SOFT_I2C_READ_REPEATED_START 1946 1947 defining this will force the i2c_read() function in 1948 the soft_i2c driver to perform an I2C repeated start 1949 between writing the address pointer and reading the 1950 data. If this define is omitted the default behaviour 1951 of doing a stop-start sequence will be used. Most I2C 1952 devices can use either method, but some require one or 1953 the other. 1954 1955- SPI Support: CONFIG_SPI 1956 1957 Enables SPI driver (so far only tested with 1958 SPI EEPROM, also an instance works with Crystal A/D and 1959 D/As on the SACSng board) 1960 1961 CONFIG_SOFT_SPI 1962 1963 Enables a software (bit-bang) SPI driver rather than 1964 using hardware support. This is a general purpose 1965 driver that only requires three general I/O port pins 1966 (two outputs, one input) to function. If this is 1967 defined, the board configuration must define several 1968 SPI configuration items (port pins to use, etc). For 1969 an example, see include/configs/sacsng.h. 1970 1971 CONFIG_HARD_SPI 1972 1973 Enables a hardware SPI driver for general-purpose reads 1974 and writes. As with CONFIG_SOFT_SPI, the board configuration 1975 must define a list of chip-select function pointers. 1976 Currently supported on some MPC8xxx processors. For an 1977 example, see include/configs/mpc8349emds.h. 1978 1979 CONFIG_SYS_SPI_MXC_WAIT 1980 Timeout for waiting until spi transfer completed. 1981 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1982 1983- FPGA Support: CONFIG_FPGA 1984 1985 Enables FPGA subsystem. 1986 1987 CONFIG_FPGA_<vendor> 1988 1989 Enables support for specific chip vendors. 1990 (ALTERA, XILINX) 1991 1992 CONFIG_FPGA_<family> 1993 1994 Enables support for FPGA family. 1995 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1996 1997 CONFIG_FPGA_COUNT 1998 1999 Specify the number of FPGA devices to support. 2000 2001 CONFIG_SYS_FPGA_PROG_FEEDBACK 2002 2003 Enable printing of hash marks during FPGA configuration. 2004 2005 CONFIG_SYS_FPGA_CHECK_BUSY 2006 2007 Enable checks on FPGA configuration interface busy 2008 status by the configuration function. This option 2009 will require a board or device specific function to 2010 be written. 2011 2012 CONFIG_FPGA_DELAY 2013 2014 If defined, a function that provides delays in the FPGA 2015 configuration driver. 2016 2017 CONFIG_SYS_FPGA_CHECK_CTRLC 2018 Allow Control-C to interrupt FPGA configuration 2019 2020 CONFIG_SYS_FPGA_CHECK_ERROR 2021 2022 Check for configuration errors during FPGA bitfile 2023 loading. For example, abort during Virtex II 2024 configuration if the INIT_B line goes low (which 2025 indicated a CRC error). 2026 2027 CONFIG_SYS_FPGA_WAIT_INIT 2028 2029 Maximum time to wait for the INIT_B line to de-assert 2030 after PROB_B has been de-asserted during a Virtex II 2031 FPGA configuration sequence. The default time is 500 2032 ms. 2033 2034 CONFIG_SYS_FPGA_WAIT_BUSY 2035 2036 Maximum time to wait for BUSY to de-assert during 2037 Virtex II FPGA configuration. The default is 5 ms. 2038 2039 CONFIG_SYS_FPGA_WAIT_CONFIG 2040 2041 Time to wait after FPGA configuration. The default is 2042 200 ms. 2043 2044- Configuration Management: 2045 CONFIG_BUILD_TARGET 2046 2047 Some SoCs need special image types (e.g. U-Boot binary 2048 with a special header) as build targets. By defining 2049 CONFIG_BUILD_TARGET in the SoC / board header, this 2050 special image will be automatically built upon calling 2051 make / buildman. 2052 2053 CONFIG_IDENT_STRING 2054 2055 If defined, this string will be added to the U-Boot 2056 version information (U_BOOT_VERSION) 2057 2058- Vendor Parameter Protection: 2059 2060 U-Boot considers the values of the environment 2061 variables "serial#" (Board Serial Number) and 2062 "ethaddr" (Ethernet Address) to be parameters that 2063 are set once by the board vendor / manufacturer, and 2064 protects these variables from casual modification by 2065 the user. Once set, these variables are read-only, 2066 and write or delete attempts are rejected. You can 2067 change this behaviour: 2068 2069 If CONFIG_ENV_OVERWRITE is #defined in your config 2070 file, the write protection for vendor parameters is 2071 completely disabled. Anybody can change or delete 2072 these parameters. 2073 2074 Alternatively, if you define _both_ an ethaddr in the 2075 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2076 Ethernet address is installed in the environment, 2077 which can be changed exactly ONCE by the user. [The 2078 serial# is unaffected by this, i. e. it remains 2079 read-only.] 2080 2081 The same can be accomplished in a more flexible way 2082 for any variable by configuring the type of access 2083 to allow for those variables in the ".flags" variable 2084 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2085 2086- Protected RAM: 2087 CONFIG_PRAM 2088 2089 Define this variable to enable the reservation of 2090 "protected RAM", i. e. RAM which is not overwritten 2091 by U-Boot. Define CONFIG_PRAM to hold the number of 2092 kB you want to reserve for pRAM. You can overwrite 2093 this default value by defining an environment 2094 variable "pram" to the number of kB you want to 2095 reserve. Note that the board info structure will 2096 still show the full amount of RAM. If pRAM is 2097 reserved, a new environment variable "mem" will 2098 automatically be defined to hold the amount of 2099 remaining RAM in a form that can be passed as boot 2100 argument to Linux, for instance like that: 2101 2102 setenv bootargs ... mem=\${mem} 2103 saveenv 2104 2105 This way you can tell Linux not to use this memory, 2106 either, which results in a memory region that will 2107 not be affected by reboots. 2108 2109 *WARNING* If your board configuration uses automatic 2110 detection of the RAM size, you must make sure that 2111 this memory test is non-destructive. So far, the 2112 following board configurations are known to be 2113 "pRAM-clean": 2114 2115 IVMS8, IVML24, SPD8xx, 2116 HERMES, IP860, RPXlite, LWMON, 2117 FLAGADM 2118 2119- Access to physical memory region (> 4GB) 2120 Some basic support is provided for operations on memory not 2121 normally accessible to U-Boot - e.g. some architectures 2122 support access to more than 4GB of memory on 32-bit 2123 machines using physical address extension or similar. 2124 Define CONFIG_PHYSMEM to access this basic support, which 2125 currently only supports clearing the memory. 2126 2127- Error Recovery: 2128 CONFIG_NET_RETRY_COUNT 2129 2130 This variable defines the number of retries for 2131 network operations like ARP, RARP, TFTP, or BOOTP 2132 before giving up the operation. If not defined, a 2133 default value of 5 is used. 2134 2135 CONFIG_ARP_TIMEOUT 2136 2137 Timeout waiting for an ARP reply in milliseconds. 2138 2139 CONFIG_NFS_TIMEOUT 2140 2141 Timeout in milliseconds used in NFS protocol. 2142 If you encounter "ERROR: Cannot umount" in nfs command, 2143 try longer timeout such as 2144 #define CONFIG_NFS_TIMEOUT 10000UL 2145 2146- Command Interpreter: 2147 CONFIG_SYS_PROMPT_HUSH_PS2 2148 2149 This defines the secondary prompt string, which is 2150 printed when the command interpreter needs more input 2151 to complete a command. Usually "> ". 2152 2153 Note: 2154 2155 In the current implementation, the local variables 2156 space and global environment variables space are 2157 separated. Local variables are those you define by 2158 simply typing `name=value'. To access a local 2159 variable later on, you have write `$name' or 2160 `${name}'; to execute the contents of a variable 2161 directly type `$name' at the command prompt. 2162 2163 Global environment variables are those you use 2164 setenv/printenv to work with. To run a command stored 2165 in such a variable, you need to use the run command, 2166 and you must not use the '$' sign to access them. 2167 2168 To store commands and special characters in a 2169 variable, please use double quotation marks 2170 surrounding the whole text of the variable, instead 2171 of the backslashes before semicolons and special 2172 symbols. 2173 2174- Command Line Editing and History: 2175 CONFIG_CMDLINE_PS_SUPPORT 2176 2177 Enable support for changing the command prompt string 2178 at run-time. Only static string is supported so far. 2179 The string is obtained from environment variables PS1 2180 and PS2. 2181 2182- Default Environment: 2183 CONFIG_EXTRA_ENV_SETTINGS 2184 2185 Define this to contain any number of null terminated 2186 strings (variable = value pairs) that will be part of 2187 the default environment compiled into the boot image. 2188 2189 For example, place something like this in your 2190 board's config file: 2191 2192 #define CONFIG_EXTRA_ENV_SETTINGS \ 2193 "myvar1=value1\0" \ 2194 "myvar2=value2\0" 2195 2196 Warning: This method is based on knowledge about the 2197 internal format how the environment is stored by the 2198 U-Boot code. This is NOT an official, exported 2199 interface! Although it is unlikely that this format 2200 will change soon, there is no guarantee either. 2201 You better know what you are doing here. 2202 2203 Note: overly (ab)use of the default environment is 2204 discouraged. Make sure to check other ways to preset 2205 the environment like the "source" command or the 2206 boot command first. 2207 2208 CONFIG_DELAY_ENVIRONMENT 2209 2210 Normally the environment is loaded when the board is 2211 initialised so that it is available to U-Boot. This inhibits 2212 that so that the environment is not available until 2213 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2214 this is instead controlled by the value of 2215 /config/load-environment. 2216 2217- Serial Flash support 2218 Usage requires an initial 'sf probe' to define the serial 2219 flash parameters, followed by read/write/erase/update 2220 commands. 2221 2222 The following defaults may be provided by the platform 2223 to handle the common case when only a single serial 2224 flash is present on the system. 2225 2226 CONFIG_SF_DEFAULT_BUS Bus identifier 2227 CONFIG_SF_DEFAULT_CS Chip-select 2228 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2229 CONFIG_SF_DEFAULT_SPEED in Hz 2230 2231 2232- TFTP Fixed UDP Port: 2233 CONFIG_TFTP_PORT 2234 2235 If this is defined, the environment variable tftpsrcp 2236 is used to supply the TFTP UDP source port value. 2237 If tftpsrcp isn't defined, the normal pseudo-random port 2238 number generator is used. 2239 2240 Also, the environment variable tftpdstp is used to supply 2241 the TFTP UDP destination port value. If tftpdstp isn't 2242 defined, the normal port 69 is used. 2243 2244 The purpose for tftpsrcp is to allow a TFTP server to 2245 blindly start the TFTP transfer using the pre-configured 2246 target IP address and UDP port. This has the effect of 2247 "punching through" the (Windows XP) firewall, allowing 2248 the remainder of the TFTP transfer to proceed normally. 2249 A better solution is to properly configure the firewall, 2250 but sometimes that is not allowed. 2251 2252- Show boot progress: 2253 CONFIG_SHOW_BOOT_PROGRESS 2254 2255 Defining this option allows to add some board- 2256 specific code (calling a user-provided function 2257 "show_boot_progress(int)") that enables you to show 2258 the system's boot progress on some display (for 2259 example, some LED's) on your board. At the moment, 2260 the following checkpoints are implemented: 2261 2262 2263Legacy uImage format: 2264 2265 Arg Where When 2266 1 common/cmd_bootm.c before attempting to boot an image 2267 -1 common/cmd_bootm.c Image header has bad magic number 2268 2 common/cmd_bootm.c Image header has correct magic number 2269 -2 common/cmd_bootm.c Image header has bad checksum 2270 3 common/cmd_bootm.c Image header has correct checksum 2271 -3 common/cmd_bootm.c Image data has bad checksum 2272 4 common/cmd_bootm.c Image data has correct checksum 2273 -4 common/cmd_bootm.c Image is for unsupported architecture 2274 5 common/cmd_bootm.c Architecture check OK 2275 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2276 6 common/cmd_bootm.c Image Type check OK 2277 -6 common/cmd_bootm.c gunzip uncompression error 2278 -7 common/cmd_bootm.c Unimplemented compression type 2279 7 common/cmd_bootm.c Uncompression OK 2280 8 common/cmd_bootm.c No uncompress/copy overwrite error 2281 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2282 2283 9 common/image.c Start initial ramdisk verification 2284 -10 common/image.c Ramdisk header has bad magic number 2285 -11 common/image.c Ramdisk header has bad checksum 2286 10 common/image.c Ramdisk header is OK 2287 -12 common/image.c Ramdisk data has bad checksum 2288 11 common/image.c Ramdisk data has correct checksum 2289 12 common/image.c Ramdisk verification complete, start loading 2290 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2291 13 common/image.c Start multifile image verification 2292 14 common/image.c No initial ramdisk, no multifile, continue. 2293 2294 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2295 2296 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2297 -31 post/post.c POST test failed, detected by post_output_backlog() 2298 -32 post/post.c POST test failed, detected by post_run_single() 2299 2300 34 common/cmd_doc.c before loading a Image from a DOC device 2301 -35 common/cmd_doc.c Bad usage of "doc" command 2302 35 common/cmd_doc.c correct usage of "doc" command 2303 -36 common/cmd_doc.c No boot device 2304 36 common/cmd_doc.c correct boot device 2305 -37 common/cmd_doc.c Unknown Chip ID on boot device 2306 37 common/cmd_doc.c correct chip ID found, device available 2307 -38 common/cmd_doc.c Read Error on boot device 2308 38 common/cmd_doc.c reading Image header from DOC device OK 2309 -39 common/cmd_doc.c Image header has bad magic number 2310 39 common/cmd_doc.c Image header has correct magic number 2311 -40 common/cmd_doc.c Error reading Image from DOC device 2312 40 common/cmd_doc.c Image header has correct magic number 2313 41 common/cmd_ide.c before loading a Image from a IDE device 2314 -42 common/cmd_ide.c Bad usage of "ide" command 2315 42 common/cmd_ide.c correct usage of "ide" command 2316 -43 common/cmd_ide.c No boot device 2317 43 common/cmd_ide.c boot device found 2318 -44 common/cmd_ide.c Device not available 2319 44 common/cmd_ide.c Device available 2320 -45 common/cmd_ide.c wrong partition selected 2321 45 common/cmd_ide.c partition selected 2322 -46 common/cmd_ide.c Unknown partition table 2323 46 common/cmd_ide.c valid partition table found 2324 -47 common/cmd_ide.c Invalid partition type 2325 47 common/cmd_ide.c correct partition type 2326 -48 common/cmd_ide.c Error reading Image Header on boot device 2327 48 common/cmd_ide.c reading Image Header from IDE device OK 2328 -49 common/cmd_ide.c Image header has bad magic number 2329 49 common/cmd_ide.c Image header has correct magic number 2330 -50 common/cmd_ide.c Image header has bad checksum 2331 50 common/cmd_ide.c Image header has correct checksum 2332 -51 common/cmd_ide.c Error reading Image from IDE device 2333 51 common/cmd_ide.c reading Image from IDE device OK 2334 52 common/cmd_nand.c before loading a Image from a NAND device 2335 -53 common/cmd_nand.c Bad usage of "nand" command 2336 53 common/cmd_nand.c correct usage of "nand" command 2337 -54 common/cmd_nand.c No boot device 2338 54 common/cmd_nand.c boot device found 2339 -55 common/cmd_nand.c Unknown Chip ID on boot device 2340 55 common/cmd_nand.c correct chip ID found, device available 2341 -56 common/cmd_nand.c Error reading Image Header on boot device 2342 56 common/cmd_nand.c reading Image Header from NAND device OK 2343 -57 common/cmd_nand.c Image header has bad magic number 2344 57 common/cmd_nand.c Image header has correct magic number 2345 -58 common/cmd_nand.c Error reading Image from NAND device 2346 58 common/cmd_nand.c reading Image from NAND device OK 2347 2348 -60 common/env_common.c Environment has a bad CRC, using default 2349 2350 64 net/eth.c starting with Ethernet configuration. 2351 -64 net/eth.c no Ethernet found. 2352 65 net/eth.c Ethernet found. 2353 2354 -80 common/cmd_net.c usage wrong 2355 80 common/cmd_net.c before calling net_loop() 2356 -81 common/cmd_net.c some error in net_loop() occurred 2357 81 common/cmd_net.c net_loop() back without error 2358 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2359 82 common/cmd_net.c trying automatic boot 2360 83 common/cmd_net.c running "source" command 2361 -83 common/cmd_net.c some error in automatic boot or "source" command 2362 84 common/cmd_net.c end without errors 2363 2364FIT uImage format: 2365 2366 Arg Where When 2367 100 common/cmd_bootm.c Kernel FIT Image has correct format 2368 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2369 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2370 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2371 102 common/cmd_bootm.c Kernel unit name specified 2372 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2373 103 common/cmd_bootm.c Found configuration node 2374 104 common/cmd_bootm.c Got kernel subimage node offset 2375 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2376 105 common/cmd_bootm.c Kernel subimage hash verification OK 2377 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2378 106 common/cmd_bootm.c Architecture check OK 2379 -106 common/cmd_bootm.c Kernel subimage has wrong type 2380 107 common/cmd_bootm.c Kernel subimage type OK 2381 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2382 108 common/cmd_bootm.c Got kernel subimage data/size 2383 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2384 -109 common/cmd_bootm.c Can't get kernel subimage type 2385 -110 common/cmd_bootm.c Can't get kernel subimage comp 2386 -111 common/cmd_bootm.c Can't get kernel subimage os 2387 -112 common/cmd_bootm.c Can't get kernel subimage load address 2388 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2389 2390 120 common/image.c Start initial ramdisk verification 2391 -120 common/image.c Ramdisk FIT image has incorrect format 2392 121 common/image.c Ramdisk FIT image has correct format 2393 122 common/image.c No ramdisk subimage unit name, using configuration 2394 -122 common/image.c Can't get configuration for ramdisk subimage 2395 123 common/image.c Ramdisk unit name specified 2396 -124 common/image.c Can't get ramdisk subimage node offset 2397 125 common/image.c Got ramdisk subimage node offset 2398 -125 common/image.c Ramdisk subimage hash verification failed 2399 126 common/image.c Ramdisk subimage hash verification OK 2400 -126 common/image.c Ramdisk subimage for unsupported architecture 2401 127 common/image.c Architecture check OK 2402 -127 common/image.c Can't get ramdisk subimage data/size 2403 128 common/image.c Got ramdisk subimage data/size 2404 129 common/image.c Can't get ramdisk load address 2405 -129 common/image.c Got ramdisk load address 2406 2407 -130 common/cmd_doc.c Incorrect FIT image format 2408 131 common/cmd_doc.c FIT image format OK 2409 2410 -140 common/cmd_ide.c Incorrect FIT image format 2411 141 common/cmd_ide.c FIT image format OK 2412 2413 -150 common/cmd_nand.c Incorrect FIT image format 2414 151 common/cmd_nand.c FIT image format OK 2415 2416- legacy image format: 2417 CONFIG_IMAGE_FORMAT_LEGACY 2418 enables the legacy image format support in U-Boot. 2419 2420 Default: 2421 enabled if CONFIG_FIT_SIGNATURE is not defined. 2422 2423 CONFIG_DISABLE_IMAGE_LEGACY 2424 disable the legacy image format 2425 2426 This define is introduced, as the legacy image format is 2427 enabled per default for backward compatibility. 2428 2429- Standalone program support: 2430 CONFIG_STANDALONE_LOAD_ADDR 2431 2432 This option defines a board specific value for the 2433 address where standalone program gets loaded, thus 2434 overwriting the architecture dependent default 2435 settings. 2436 2437- Frame Buffer Address: 2438 CONFIG_FB_ADDR 2439 2440 Define CONFIG_FB_ADDR if you want to use specific 2441 address for frame buffer. This is typically the case 2442 when using a graphics controller has separate video 2443 memory. U-Boot will then place the frame buffer at 2444 the given address instead of dynamically reserving it 2445 in system RAM by calling lcd_setmem(), which grabs 2446 the memory for the frame buffer depending on the 2447 configured panel size. 2448 2449 Please see board_init_f function. 2450 2451- Automatic software updates via TFTP server 2452 CONFIG_UPDATE_TFTP 2453 CONFIG_UPDATE_TFTP_CNT_MAX 2454 CONFIG_UPDATE_TFTP_MSEC_MAX 2455 2456 These options enable and control the auto-update feature; 2457 for a more detailed description refer to doc/README.update. 2458 2459- MTD Support (mtdparts command, UBI support) 2460 CONFIG_MTD_DEVICE 2461 2462 Adds the MTD device infrastructure from the Linux kernel. 2463 Needed for mtdparts command support. 2464 2465 CONFIG_MTD_PARTITIONS 2466 2467 Adds the MTD partitioning infrastructure from the Linux 2468 kernel. Needed for UBI support. 2469 2470- UBI support 2471 CONFIG_MTD_UBI_WL_THRESHOLD 2472 This parameter defines the maximum difference between the highest 2473 erase counter value and the lowest erase counter value of eraseblocks 2474 of UBI devices. When this threshold is exceeded, UBI starts performing 2475 wear leveling by means of moving data from eraseblock with low erase 2476 counter to eraseblocks with high erase counter. 2477 2478 The default value should be OK for SLC NAND flashes, NOR flashes and 2479 other flashes which have eraseblock life-cycle 100000 or more. 2480 However, in case of MLC NAND flashes which typically have eraseblock 2481 life-cycle less than 10000, the threshold should be lessened (e.g., 2482 to 128 or 256, although it does not have to be power of 2). 2483 2484 default: 4096 2485 2486 CONFIG_MTD_UBI_BEB_LIMIT 2487 This option specifies the maximum bad physical eraseblocks UBI 2488 expects on the MTD device (per 1024 eraseblocks). If the 2489 underlying flash does not admit of bad eraseblocks (e.g. NOR 2490 flash), this value is ignored. 2491 2492 NAND datasheets often specify the minimum and maximum NVM 2493 (Number of Valid Blocks) for the flashes' endurance lifetime. 2494 The maximum expected bad eraseblocks per 1024 eraseblocks 2495 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2496 which gives 20 for most NANDs (MaxNVB is basically the total 2497 count of eraseblocks on the chip). 2498 2499 To put it differently, if this value is 20, UBI will try to 2500 reserve about 1.9% of physical eraseblocks for bad blocks 2501 handling. And that will be 1.9% of eraseblocks on the entire 2502 NAND chip, not just the MTD partition UBI attaches. This means 2503 that if you have, say, a NAND flash chip admits maximum 40 bad 2504 eraseblocks, and it is split on two MTD partitions of the same 2505 size, UBI will reserve 40 eraseblocks when attaching a 2506 partition. 2507 2508 default: 20 2509 2510 CONFIG_MTD_UBI_FASTMAP 2511 Fastmap is a mechanism which allows attaching an UBI device 2512 in nearly constant time. Instead of scanning the whole MTD device it 2513 only has to locate a checkpoint (called fastmap) on the device. 2514 The on-flash fastmap contains all information needed to attach 2515 the device. Using fastmap makes only sense on large devices where 2516 attaching by scanning takes long. UBI will not automatically install 2517 a fastmap on old images, but you can set the UBI parameter 2518 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2519 that fastmap-enabled images are still usable with UBI implementations 2520 without fastmap support. On typical flash devices the whole fastmap 2521 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2522 2523 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2524 Set this parameter to enable fastmap automatically on images 2525 without a fastmap. 2526 default: 0 2527 2528 CONFIG_MTD_UBI_FM_DEBUG 2529 Enable UBI fastmap debug 2530 default: 0 2531 2532- SPL framework 2533 CONFIG_SPL 2534 Enable building of SPL globally. 2535 2536 CONFIG_SPL_LDSCRIPT 2537 LDSCRIPT for linking the SPL binary. 2538 2539 CONFIG_SPL_MAX_FOOTPRINT 2540 Maximum size in memory allocated to the SPL, BSS included. 2541 When defined, the linker checks that the actual memory 2542 used by SPL from _start to __bss_end does not exceed it. 2543 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2544 must not be both defined at the same time. 2545 2546 CONFIG_SPL_MAX_SIZE 2547 Maximum size of the SPL image (text, data, rodata, and 2548 linker lists sections), BSS excluded. 2549 When defined, the linker checks that the actual size does 2550 not exceed it. 2551 2552 CONFIG_SPL_TEXT_BASE 2553 TEXT_BASE for linking the SPL binary. 2554 2555 CONFIG_SPL_RELOC_TEXT_BASE 2556 Address to relocate to. If unspecified, this is equal to 2557 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2558 2559 CONFIG_SPL_BSS_START_ADDR 2560 Link address for the BSS within the SPL binary. 2561 2562 CONFIG_SPL_BSS_MAX_SIZE 2563 Maximum size in memory allocated to the SPL BSS. 2564 When defined, the linker checks that the actual memory used 2565 by SPL from __bss_start to __bss_end does not exceed it. 2566 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2567 must not be both defined at the same time. 2568 2569 CONFIG_SPL_STACK 2570 Adress of the start of the stack SPL will use 2571 2572 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2573 When defined, SPL will panic() if the image it has 2574 loaded does not have a signature. 2575 Defining this is useful when code which loads images 2576 in SPL cannot guarantee that absolutely all read errors 2577 will be caught. 2578 An example is the LPC32XX MLC NAND driver, which will 2579 consider that a completely unreadable NAND block is bad, 2580 and thus should be skipped silently. 2581 2582 CONFIG_SPL_RELOC_STACK 2583 Adress of the start of the stack SPL will use after 2584 relocation. If unspecified, this is equal to 2585 CONFIG_SPL_STACK. 2586 2587 CONFIG_SYS_SPL_MALLOC_START 2588 Starting address of the malloc pool used in SPL. 2589 When this option is set the full malloc is used in SPL and 2590 it is set up by spl_init() and before that, the simple malloc() 2591 can be used if CONFIG_SYS_MALLOC_F is defined. 2592 2593 CONFIG_SYS_SPL_MALLOC_SIZE 2594 The size of the malloc pool used in SPL. 2595 2596 CONFIG_SPL_OS_BOOT 2597 Enable booting directly to an OS from SPL. 2598 See also: doc/README.falcon 2599 2600 CONFIG_SPL_DISPLAY_PRINT 2601 For ARM, enable an optional function to print more information 2602 about the running system. 2603 2604 CONFIG_SPL_INIT_MINIMAL 2605 Arch init code should be built for a very small image 2606 2607 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2608 Partition on the MMC to load U-Boot from when the MMC is being 2609 used in raw mode 2610 2611 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2612 Sector to load kernel uImage from when MMC is being 2613 used in raw mode (for Falcon mode) 2614 2615 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2616 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2617 Sector and number of sectors to load kernel argument 2618 parameters from when MMC is being used in raw mode 2619 (for falcon mode) 2620 2621 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2622 Partition on the MMC to load U-Boot from when the MMC is being 2623 used in fs mode 2624 2625 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2626 Filename to read to load U-Boot when reading from filesystem 2627 2628 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2629 Filename to read to load kernel uImage when reading 2630 from filesystem (for Falcon mode) 2631 2632 CONFIG_SPL_FS_LOAD_ARGS_NAME 2633 Filename to read to load kernel argument parameters 2634 when reading from filesystem (for Falcon mode) 2635 2636 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2637 Set this for NAND SPL on PPC mpc83xx targets, so that 2638 start.S waits for the rest of the SPL to load before 2639 continuing (the hardware starts execution after just 2640 loading the first page rather than the full 4K). 2641 2642 CONFIG_SPL_SKIP_RELOCATE 2643 Avoid SPL relocation 2644 2645 CONFIG_SPL_NAND_BASE 2646 Include nand_base.c in the SPL. Requires 2647 CONFIG_SPL_NAND_DRIVERS. 2648 2649 CONFIG_SPL_NAND_DRIVERS 2650 SPL uses normal NAND drivers, not minimal drivers. 2651 2652 CONFIG_SPL_NAND_ECC 2653 Include standard software ECC in the SPL 2654 2655 CONFIG_SPL_NAND_SIMPLE 2656 Support for NAND boot using simple NAND drivers that 2657 expose the cmd_ctrl() interface. 2658 2659 CONFIG_SPL_UBI 2660 Support for a lightweight UBI (fastmap) scanner and 2661 loader 2662 2663 CONFIG_SPL_NAND_RAW_ONLY 2664 Support to boot only raw u-boot.bin images. Use this only 2665 if you need to save space. 2666 2667 CONFIG_SPL_COMMON_INIT_DDR 2668 Set for common ddr init with serial presence detect in 2669 SPL binary. 2670 2671 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2672 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2673 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2674 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2675 CONFIG_SYS_NAND_ECCBYTES 2676 Defines the size and behavior of the NAND that SPL uses 2677 to read U-Boot 2678 2679 CONFIG_SPL_NAND_BOOT 2680 Add support NAND boot 2681 2682 CONFIG_SYS_NAND_U_BOOT_OFFS 2683 Location in NAND to read U-Boot from 2684 2685 CONFIG_SYS_NAND_U_BOOT_DST 2686 Location in memory to load U-Boot to 2687 2688 CONFIG_SYS_NAND_U_BOOT_SIZE 2689 Size of image to load 2690 2691 CONFIG_SYS_NAND_U_BOOT_START 2692 Entry point in loaded image to jump to 2693 2694 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2695 Define this if you need to first read the OOB and then the 2696 data. This is used, for example, on davinci platforms. 2697 2698 CONFIG_SPL_RAM_DEVICE 2699 Support for running image already present in ram, in SPL binary 2700 2701 CONFIG_SPL_PAD_TO 2702 Image offset to which the SPL should be padded before appending 2703 the SPL payload. By default, this is defined as 2704 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2705 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2706 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2707 2708 CONFIG_SPL_TARGET 2709 Final target image containing SPL and payload. Some SPLs 2710 use an arch-specific makefile fragment instead, for 2711 example if more than one image needs to be produced. 2712 2713 CONFIG_FIT_SPL_PRINT 2714 Printing information about a FIT image adds quite a bit of 2715 code to SPL. So this is normally disabled in SPL. Use this 2716 option to re-enable it. This will affect the output of the 2717 bootm command when booting a FIT image. 2718 2719- TPL framework 2720 CONFIG_TPL 2721 Enable building of TPL globally. 2722 2723 CONFIG_TPL_PAD_TO 2724 Image offset to which the TPL should be padded before appending 2725 the TPL payload. By default, this is defined as 2726 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2727 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2728 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2729 2730- Interrupt support (PPC): 2731 2732 There are common interrupt_init() and timer_interrupt() 2733 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2734 for CPU specific initialization. interrupt_init_cpu() 2735 should set decrementer_count to appropriate value. If 2736 CPU resets decrementer automatically after interrupt 2737 (ppc4xx) it should set decrementer_count to zero. 2738 timer_interrupt() calls timer_interrupt_cpu() for CPU 2739 specific handling. If board has watchdog / status_led 2740 / other_activity_monitor it works automatically from 2741 general timer_interrupt(). 2742 2743 2744Board initialization settings: 2745------------------------------ 2746 2747During Initialization u-boot calls a number of board specific functions 2748to allow the preparation of board specific prerequisites, e.g. pin setup 2749before drivers are initialized. To enable these callbacks the 2750following configuration macros have to be defined. Currently this is 2751architecture specific, so please check arch/your_architecture/lib/board.c 2752typically in board_init_f() and board_init_r(). 2753 2754- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2755- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2756- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2757- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2758 2759Configuration Settings: 2760----------------------- 2761 2762- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2763 Optionally it can be defined to support 64-bit memory commands. 2764 2765- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2766 undefine this when you're short of memory. 2767 2768- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2769 width of the commands listed in the 'help' command output. 2770 2771- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2772 prompt for user input. 2773 2774- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2775 2776- CONFIG_SYS_PBSIZE: Buffer size for Console output 2777 2778- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2779 2780- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2781 the application (usually a Linux kernel) when it is 2782 booted 2783 2784- CONFIG_SYS_BAUDRATE_TABLE: 2785 List of legal baudrate settings for this board. 2786 2787- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2788 Begin and End addresses of the area used by the 2789 simple memory test. 2790 2791- CONFIG_SYS_MEMTEST_SCRATCH: 2792 Scratch address used by the alternate memory test 2793 You only need to set this if address zero isn't writeable 2794 2795- CONFIG_SYS_MEM_RESERVE_SECURE 2796 Only implemented for ARMv8 for now. 2797 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2798 is substracted from total RAM and won't be reported to OS. 2799 This memory can be used as secure memory. A variable 2800 gd->arch.secure_ram is used to track the location. In systems 2801 the RAM base is not zero, or RAM is divided into banks, 2802 this variable needs to be recalcuated to get the address. 2803 2804- CONFIG_SYS_MEM_TOP_HIDE: 2805 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2806 this specified memory area will get subtracted from the top 2807 (end) of RAM and won't get "touched" at all by U-Boot. By 2808 fixing up gd->ram_size the Linux kernel should gets passed 2809 the now "corrected" memory size and won't touch it either. 2810 This should work for arch/ppc and arch/powerpc. Only Linux 2811 board ports in arch/powerpc with bootwrapper support that 2812 recalculate the memory size from the SDRAM controller setup 2813 will have to get fixed in Linux additionally. 2814 2815 This option can be used as a workaround for the 440EPx/GRx 2816 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2817 be touched. 2818 2819 WARNING: Please make sure that this value is a multiple of 2820 the Linux page size (normally 4k). If this is not the case, 2821 then the end address of the Linux memory will be located at a 2822 non page size aligned address and this could cause major 2823 problems. 2824 2825- CONFIG_SYS_LOADS_BAUD_CHANGE: 2826 Enable temporary baudrate change while serial download 2827 2828- CONFIG_SYS_SDRAM_BASE: 2829 Physical start address of SDRAM. _Must_ be 0 here. 2830 2831- CONFIG_SYS_FLASH_BASE: 2832 Physical start address of Flash memory. 2833 2834- CONFIG_SYS_MONITOR_BASE: 2835 Physical start address of boot monitor code (set by 2836 make config files to be same as the text base address 2837 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2838 CONFIG_SYS_FLASH_BASE when booting from flash. 2839 2840- CONFIG_SYS_MONITOR_LEN: 2841 Size of memory reserved for monitor code, used to 2842 determine _at_compile_time_ (!) if the environment is 2843 embedded within the U-Boot image, or in a separate 2844 flash sector. 2845 2846- CONFIG_SYS_MALLOC_LEN: 2847 Size of DRAM reserved for malloc() use. 2848 2849- CONFIG_SYS_MALLOC_F_LEN 2850 Size of the malloc() pool for use before relocation. If 2851 this is defined, then a very simple malloc() implementation 2852 will become available before relocation. The address is just 2853 below the global data, and the stack is moved down to make 2854 space. 2855 2856 This feature allocates regions with increasing addresses 2857 within the region. calloc() is supported, but realloc() 2858 is not available. free() is supported but does nothing. 2859 The memory will be freed (or in fact just forgotten) when 2860 U-Boot relocates itself. 2861 2862- CONFIG_SYS_MALLOC_SIMPLE 2863 Provides a simple and small malloc() and calloc() for those 2864 boards which do not use the full malloc in SPL (which is 2865 enabled with CONFIG_SYS_SPL_MALLOC_START). 2866 2867- CONFIG_SYS_NONCACHED_MEMORY: 2868 Size of non-cached memory area. This area of memory will be 2869 typically located right below the malloc() area and mapped 2870 uncached in the MMU. This is useful for drivers that would 2871 otherwise require a lot of explicit cache maintenance. For 2872 some drivers it's also impossible to properly maintain the 2873 cache. For example if the regions that need to be flushed 2874 are not a multiple of the cache-line size, *and* padding 2875 cannot be allocated between the regions to align them (i.e. 2876 if the HW requires a contiguous array of regions, and the 2877 size of each region is not cache-aligned), then a flush of 2878 one region may result in overwriting data that hardware has 2879 written to another region in the same cache-line. This can 2880 happen for example in network drivers where descriptors for 2881 buffers are typically smaller than the CPU cache-line (e.g. 2882 16 bytes vs. 32 or 64 bytes). 2883 2884 Non-cached memory is only supported on 32-bit ARM at present. 2885 2886- CONFIG_SYS_BOOTM_LEN: 2887 Normally compressed uImages are limited to an 2888 uncompressed size of 8 MBytes. If this is not enough, 2889 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2890 to adjust this setting to your needs. 2891 2892- CONFIG_SYS_BOOTMAPSZ: 2893 Maximum size of memory mapped by the startup code of 2894 the Linux kernel; all data that must be processed by 2895 the Linux kernel (bd_info, boot arguments, FDT blob if 2896 used) must be put below this limit, unless "bootm_low" 2897 environment variable is defined and non-zero. In such case 2898 all data for the Linux kernel must be between "bootm_low" 2899 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2900 variable "bootm_mapsize" will override the value of 2901 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2902 then the value in "bootm_size" will be used instead. 2903 2904- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2905 Enable initrd_high functionality. If defined then the 2906 initrd_high feature is enabled and the bootm ramdisk subcommand 2907 is enabled. 2908 2909- CONFIG_SYS_BOOT_GET_CMDLINE: 2910 Enables allocating and saving kernel cmdline in space between 2911 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2912 2913- CONFIG_SYS_BOOT_GET_KBD: 2914 Enables allocating and saving a kernel copy of the bd_info in 2915 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2916 2917- CONFIG_SYS_MAX_FLASH_BANKS: 2918 Max number of Flash memory banks 2919 2920- CONFIG_SYS_MAX_FLASH_SECT: 2921 Max number of sectors on a Flash chip 2922 2923- CONFIG_SYS_FLASH_ERASE_TOUT: 2924 Timeout for Flash erase operations (in ms) 2925 2926- CONFIG_SYS_FLASH_WRITE_TOUT: 2927 Timeout for Flash write operations (in ms) 2928 2929- CONFIG_SYS_FLASH_LOCK_TOUT 2930 Timeout for Flash set sector lock bit operation (in ms) 2931 2932- CONFIG_SYS_FLASH_UNLOCK_TOUT 2933 Timeout for Flash clear lock bits operation (in ms) 2934 2935- CONFIG_SYS_FLASH_PROTECTION 2936 If defined, hardware flash sectors protection is used 2937 instead of U-Boot software protection. 2938 2939- CONFIG_SYS_DIRECT_FLASH_TFTP: 2940 2941 Enable TFTP transfers directly to flash memory; 2942 without this option such a download has to be 2943 performed in two steps: (1) download to RAM, and (2) 2944 copy from RAM to flash. 2945 2946 The two-step approach is usually more reliable, since 2947 you can check if the download worked before you erase 2948 the flash, but in some situations (when system RAM is 2949 too limited to allow for a temporary copy of the 2950 downloaded image) this option may be very useful. 2951 2952- CONFIG_SYS_FLASH_CFI: 2953 Define if the flash driver uses extra elements in the 2954 common flash structure for storing flash geometry. 2955 2956- CONFIG_FLASH_CFI_DRIVER 2957 This option also enables the building of the cfi_flash driver 2958 in the drivers directory 2959 2960- CONFIG_FLASH_CFI_MTD 2961 This option enables the building of the cfi_mtd driver 2962 in the drivers directory. The driver exports CFI flash 2963 to the MTD layer. 2964 2965- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2966 Use buffered writes to flash. 2967 2968- CONFIG_FLASH_SPANSION_S29WS_N 2969 s29ws-n MirrorBit flash has non-standard addresses for buffered 2970 write commands. 2971 2972- CONFIG_SYS_FLASH_QUIET_TEST 2973 If this option is defined, the common CFI flash doesn't 2974 print it's warning upon not recognized FLASH banks. This 2975 is useful, if some of the configured banks are only 2976 optionally available. 2977 2978- CONFIG_FLASH_SHOW_PROGRESS 2979 If defined (must be an integer), print out countdown 2980 digits and dots. Recommended value: 45 (9..1) for 80 2981 column displays, 15 (3..1) for 40 column displays. 2982 2983- CONFIG_FLASH_VERIFY 2984 If defined, the content of the flash (destination) is compared 2985 against the source after the write operation. An error message 2986 will be printed when the contents are not identical. 2987 Please note that this option is useless in nearly all cases, 2988 since such flash programming errors usually are detected earlier 2989 while unprotecting/erasing/programming. Please only enable 2990 this option if you really know what you are doing. 2991 2992- CONFIG_SYS_RX_ETH_BUFFER: 2993 Defines the number of Ethernet receive buffers. On some 2994 Ethernet controllers it is recommended to set this value 2995 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2996 buffers can be full shortly after enabling the interface 2997 on high Ethernet traffic. 2998 Defaults to 4 if not defined. 2999 3000- CONFIG_ENV_MAX_ENTRIES 3001 3002 Maximum number of entries in the hash table that is used 3003 internally to store the environment settings. The default 3004 setting is supposed to be generous and should work in most 3005 cases. This setting can be used to tune behaviour; see 3006 lib/hashtable.c for details. 3007 3008- CONFIG_ENV_FLAGS_LIST_DEFAULT 3009- CONFIG_ENV_FLAGS_LIST_STATIC 3010 Enable validation of the values given to environment variables when 3011 calling env set. Variables can be restricted to only decimal, 3012 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3013 the variables can also be restricted to IP address or MAC address. 3014 3015 The format of the list is: 3016 type_attribute = [s|d|x|b|i|m] 3017 access_attribute = [a|r|o|c] 3018 attributes = type_attribute[access_attribute] 3019 entry = variable_name[:attributes] 3020 list = entry[,list] 3021 3022 The type attributes are: 3023 s - String (default) 3024 d - Decimal 3025 x - Hexadecimal 3026 b - Boolean ([1yYtT|0nNfF]) 3027 i - IP address 3028 m - MAC address 3029 3030 The access attributes are: 3031 a - Any (default) 3032 r - Read-only 3033 o - Write-once 3034 c - Change-default 3035 3036 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3037 Define this to a list (string) to define the ".flags" 3038 environment variable in the default or embedded environment. 3039 3040 - CONFIG_ENV_FLAGS_LIST_STATIC 3041 Define this to a list (string) to define validation that 3042 should be done if an entry is not found in the ".flags" 3043 environment variable. To override a setting in the static 3044 list, simply add an entry for the same variable name to the 3045 ".flags" variable. 3046 3047 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3048 regular expression. This allows multiple variables to define the same 3049 flags without explicitly listing them for each variable. 3050 3051- CONFIG_ENV_ACCESS_IGNORE_FORCE 3052 If defined, don't allow the -f switch to env set override variable 3053 access flags. 3054 3055- CONFIG_USE_STDINT 3056 If stdint.h is available with your toolchain you can define this 3057 option to enable it. You can provide option 'USE_STDINT=1' when 3058 building U-Boot to enable this. 3059 3060The following definitions that deal with the placement and management 3061of environment data (variable area); in general, we support the 3062following configurations: 3063 3064- CONFIG_BUILD_ENVCRC: 3065 3066 Builds up envcrc with the target environment so that external utils 3067 may easily extract it and embed it in final U-Boot images. 3068 3069BE CAREFUL! The first access to the environment happens quite early 3070in U-Boot initialization (when we try to get the setting of for the 3071console baudrate). You *MUST* have mapped your NVRAM area then, or 3072U-Boot will hang. 3073 3074Please note that even with NVRAM we still use a copy of the 3075environment in RAM: we could work on NVRAM directly, but we want to 3076keep settings there always unmodified except somebody uses "saveenv" 3077to save the current settings. 3078 3079BE CAREFUL! For some special cases, the local device can not use 3080"saveenv" command. For example, the local device will get the 3081environment stored in a remote NOR flash by SRIO or PCIE link, 3082but it can not erase, write this NOR flash by SRIO or PCIE interface. 3083 3084- CONFIG_NAND_ENV_DST 3085 3086 Defines address in RAM to which the nand_spl code should copy the 3087 environment. If redundant environment is used, it will be copied to 3088 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3089 3090Please note that the environment is read-only until the monitor 3091has been relocated to RAM and a RAM copy of the environment has been 3092created; also, when using EEPROM you will have to use env_get_f() 3093until then to read environment variables. 3094 3095The environment is protected by a CRC32 checksum. Before the monitor 3096is relocated into RAM, as a result of a bad CRC you will be working 3097with the compiled-in default environment - *silently*!!! [This is 3098necessary, because the first environment variable we need is the 3099"baudrate" setting for the console - if we have a bad CRC, we don't 3100have any device yet where we could complain.] 3101 3102Note: once the monitor has been relocated, then it will complain if 3103the default environment is used; a new CRC is computed as soon as you 3104use the "saveenv" command to store a valid environment. 3105 3106- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3107 Echo the inverted Ethernet link state to the fault LED. 3108 3109 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3110 also needs to be defined. 3111 3112- CONFIG_SYS_FAULT_MII_ADDR: 3113 MII address of the PHY to check for the Ethernet link state. 3114 3115- CONFIG_NS16550_MIN_FUNCTIONS: 3116 Define this if you desire to only have use of the NS16550_init 3117 and NS16550_putc functions for the serial driver located at 3118 drivers/serial/ns16550.c. This option is useful for saving 3119 space for already greatly restricted images, including but not 3120 limited to NAND_SPL configurations. 3121 3122- CONFIG_DISPLAY_BOARDINFO 3123 Display information about the board that U-Boot is running on 3124 when U-Boot starts up. The board function checkboard() is called 3125 to do this. 3126 3127- CONFIG_DISPLAY_BOARDINFO_LATE 3128 Similar to the previous option, but display this information 3129 later, once stdio is running and output goes to the LCD, if 3130 present. 3131 3132- CONFIG_BOARD_SIZE_LIMIT: 3133 Maximum size of the U-Boot image. When defined, the 3134 build system checks that the actual size does not 3135 exceed it. 3136 3137Low Level (hardware related) configuration options: 3138--------------------------------------------------- 3139 3140- CONFIG_SYS_CACHELINE_SIZE: 3141 Cache Line Size of the CPU. 3142 3143- CONFIG_SYS_CCSRBAR_DEFAULT: 3144 Default (power-on reset) physical address of CCSR on Freescale 3145 PowerPC SOCs. 3146 3147- CONFIG_SYS_CCSRBAR: 3148 Virtual address of CCSR. On a 32-bit build, this is typically 3149 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3150 3151- CONFIG_SYS_CCSRBAR_PHYS: 3152 Physical address of CCSR. CCSR can be relocated to a new 3153 physical address, if desired. In this case, this macro should 3154 be set to that address. Otherwise, it should be set to the 3155 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3156 is typically relocated on 36-bit builds. It is recommended 3157 that this macro be defined via the _HIGH and _LOW macros: 3158 3159 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3160 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3161 3162- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3163 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3164 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3165 used in assembly code, so it must not contain typecasts or 3166 integer size suffixes (e.g. "ULL"). 3167 3168- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3169 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3170 used in assembly code, so it must not contain typecasts or 3171 integer size suffixes (e.g. "ULL"). 3172 3173- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3174 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3175 forced to a value that ensures that CCSR is not relocated. 3176 3177- Floppy Disk Support: 3178 CONFIG_SYS_FDC_DRIVE_NUMBER 3179 3180 the default drive number (default value 0) 3181 3182 CONFIG_SYS_ISA_IO_STRIDE 3183 3184 defines the spacing between FDC chipset registers 3185 (default value 1) 3186 3187 CONFIG_SYS_ISA_IO_OFFSET 3188 3189 defines the offset of register from address. It 3190 depends on which part of the data bus is connected to 3191 the FDC chipset. (default value 0) 3192 3193 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3194 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3195 default value. 3196 3197 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3198 fdc_hw_init() is called at the beginning of the FDC 3199 setup. fdc_hw_init() must be provided by the board 3200 source code. It is used to make hardware-dependent 3201 initializations. 3202 3203- CONFIG_IDE_AHB: 3204 Most IDE controllers were designed to be connected with PCI 3205 interface. Only few of them were designed for AHB interface. 3206 When software is doing ATA command and data transfer to 3207 IDE devices through IDE-AHB controller, some additional 3208 registers accessing to these kind of IDE-AHB controller 3209 is required. 3210 3211- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3212 DO NOT CHANGE unless you know exactly what you're 3213 doing! (11-4) [MPC8xx systems only] 3214 3215- CONFIG_SYS_INIT_RAM_ADDR: 3216 3217 Start address of memory area that can be used for 3218 initial data and stack; please note that this must be 3219 writable memory that is working WITHOUT special 3220 initialization, i. e. you CANNOT use normal RAM which 3221 will become available only after programming the 3222 memory controller and running certain initialization 3223 sequences. 3224 3225 U-Boot uses the following memory types: 3226 - MPC8xx: IMMR (internal memory of the CPU) 3227 3228- CONFIG_SYS_GBL_DATA_OFFSET: 3229 3230 Offset of the initial data structure in the memory 3231 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3232 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3233 data is located at the end of the available space 3234 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3235 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3236 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3237 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3238 3239 Note: 3240 On the MPC824X (or other systems that use the data 3241 cache for initial memory) the address chosen for 3242 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3243 point to an otherwise UNUSED address space between 3244 the top of RAM and the start of the PCI space. 3245 3246- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3247 3248- CONFIG_SYS_OR_TIMING_SDRAM: 3249 SDRAM timing 3250 3251- CONFIG_SYS_MAMR_PTA: 3252 periodic timer for refresh 3253 3254- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3255 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3256 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3257 CONFIG_SYS_BR1_PRELIM: 3258 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3259 3260- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3261 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3262 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3263 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3264 3265- CONFIG_PCI_ENUM_ONLY 3266 Only scan through and get the devices on the buses. 3267 Don't do any setup work, presumably because someone or 3268 something has already done it, and we don't need to do it 3269 a second time. Useful for platforms that are pre-booted 3270 by coreboot or similar. 3271 3272- CONFIG_PCI_INDIRECT_BRIDGE: 3273 Enable support for indirect PCI bridges. 3274 3275- CONFIG_SYS_SRIO: 3276 Chip has SRIO or not 3277 3278- CONFIG_SRIO1: 3279 Board has SRIO 1 port available 3280 3281- CONFIG_SRIO2: 3282 Board has SRIO 2 port available 3283 3284- CONFIG_SRIO_PCIE_BOOT_MASTER 3285 Board can support master function for Boot from SRIO and PCIE 3286 3287- CONFIG_SYS_SRIOn_MEM_VIRT: 3288 Virtual Address of SRIO port 'n' memory region 3289 3290- CONFIG_SYS_SRIOn_MEM_PHYS: 3291 Physical Address of SRIO port 'n' memory region 3292 3293- CONFIG_SYS_SRIOn_MEM_SIZE: 3294 Size of SRIO port 'n' memory region 3295 3296- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3297 Defined to tell the NAND controller that the NAND chip is using 3298 a 16 bit bus. 3299 Not all NAND drivers use this symbol. 3300 Example of drivers that use it: 3301 - drivers/mtd/nand/ndfc.c 3302 - drivers/mtd/nand/mxc_nand.c 3303 3304- CONFIG_SYS_NDFC_EBC0_CFG 3305 Sets the EBC0_CFG register for the NDFC. If not defined 3306 a default value will be used. 3307 3308- CONFIG_SPD_EEPROM 3309 Get DDR timing information from an I2C EEPROM. Common 3310 with pluggable memory modules such as SODIMMs 3311 3312 SPD_EEPROM_ADDRESS 3313 I2C address of the SPD EEPROM 3314 3315- CONFIG_SYS_SPD_BUS_NUM 3316 If SPD EEPROM is on an I2C bus other than the first 3317 one, specify here. Note that the value must resolve 3318 to something your driver can deal with. 3319 3320- CONFIG_SYS_DDR_RAW_TIMING 3321 Get DDR timing information from other than SPD. Common with 3322 soldered DDR chips onboard without SPD. DDR raw timing 3323 parameters are extracted from datasheet and hard-coded into 3324 header files or board specific files. 3325 3326- CONFIG_FSL_DDR_INTERACTIVE 3327 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3328 3329- CONFIG_FSL_DDR_SYNC_REFRESH 3330 Enable sync of refresh for multiple controllers. 3331 3332- CONFIG_FSL_DDR_BIST 3333 Enable built-in memory test for Freescale DDR controllers. 3334 3335- CONFIG_SYS_83XX_DDR_USES_CS0 3336 Only for 83xx systems. If specified, then DDR should 3337 be configured using CS0 and CS1 instead of CS2 and CS3. 3338 3339- CONFIG_RMII 3340 Enable RMII mode for all FECs. 3341 Note that this is a global option, we can't 3342 have one FEC in standard MII mode and another in RMII mode. 3343 3344- CONFIG_CRC32_VERIFY 3345 Add a verify option to the crc32 command. 3346 The syntax is: 3347 3348 => crc32 -v <address> <count> <crc32> 3349 3350 Where address/count indicate a memory area 3351 and crc32 is the correct crc32 which the 3352 area should have. 3353 3354- CONFIG_LOOPW 3355 Add the "loopw" memory command. This only takes effect if 3356 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3357 3358- CONFIG_MX_CYCLIC 3359 Add the "mdc" and "mwc" memory commands. These are cyclic 3360 "md/mw" commands. 3361 Examples: 3362 3363 => mdc.b 10 4 500 3364 This command will print 4 bytes (10,11,12,13) each 500 ms. 3365 3366 => mwc.l 100 12345678 10 3367 This command will write 12345678 to address 100 all 10 ms. 3368 3369 This only takes effect if the memory commands are activated 3370 globally (CONFIG_CMD_MEMORY). 3371 3372- CONFIG_SKIP_LOWLEVEL_INIT 3373 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3374 low level initializations (like setting up the memory 3375 controller) are omitted and/or U-Boot does not 3376 relocate itself into RAM. 3377 3378 Normally this variable MUST NOT be defined. The only 3379 exception is when U-Boot is loaded (to RAM) by some 3380 other boot loader or by a debugger which performs 3381 these initializations itself. 3382 3383- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3384 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3385 to be skipped. The normal CP15 init (such as enabling the 3386 instruction cache) is still performed. 3387 3388- CONFIG_SPL_BUILD 3389 Modifies the behaviour of start.S when compiling a loader 3390 that is executed before the actual U-Boot. E.g. when 3391 compiling a NAND SPL. 3392 3393- CONFIG_TPL_BUILD 3394 Modifies the behaviour of start.S when compiling a loader 3395 that is executed after the SPL and before the actual U-Boot. 3396 It is loaded by the SPL. 3397 3398- CONFIG_SYS_MPC85XX_NO_RESETVEC 3399 Only for 85xx systems. If this variable is specified, the section 3400 .resetvec is not kept and the section .bootpg is placed in the 3401 previous 4k of the .text section. 3402 3403- CONFIG_ARCH_MAP_SYSMEM 3404 Generally U-Boot (and in particular the md command) uses 3405 effective address. It is therefore not necessary to regard 3406 U-Boot address as virtual addresses that need to be translated 3407 to physical addresses. However, sandbox requires this, since 3408 it maintains its own little RAM buffer which contains all 3409 addressable memory. This option causes some memory accesses 3410 to be mapped through map_sysmem() / unmap_sysmem(). 3411 3412- CONFIG_X86_RESET_VECTOR 3413 If defined, the x86 reset vector code is included. This is not 3414 needed when U-Boot is running from Coreboot. 3415 3416- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3417 Option to disable subpage write in NAND driver 3418 driver that uses this: 3419 drivers/mtd/nand/davinci_nand.c 3420 3421Freescale QE/FMAN Firmware Support: 3422----------------------------------- 3423 3424The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3425loading of "firmware", which is encoded in the QE firmware binary format. 3426This firmware often needs to be loaded during U-Boot booting, so macros 3427are used to identify the storage device (NOR flash, SPI, etc) and the address 3428within that device. 3429 3430- CONFIG_SYS_FMAN_FW_ADDR 3431 The address in the storage device where the FMAN microcode is located. The 3432 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3433 is also specified. 3434 3435- CONFIG_SYS_QE_FW_ADDR 3436 The address in the storage device where the QE microcode is located. The 3437 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3438 is also specified. 3439 3440- CONFIG_SYS_QE_FMAN_FW_LENGTH 3441 The maximum possible size of the firmware. The firmware binary format 3442 has a field that specifies the actual size of the firmware, but it 3443 might not be possible to read any part of the firmware unless some 3444 local storage is allocated to hold the entire firmware first. 3445 3446- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3447 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3448 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3449 virtual address in NOR flash. 3450 3451- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3452 Specifies that QE/FMAN firmware is located in NAND flash. 3453 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3454 3455- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3456 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3457 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3458 3459- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3460 Specifies that QE/FMAN firmware is located in the remote (master) 3461 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3462 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3463 window->master inbound window->master LAW->the ucode address in 3464 master's memory space. 3465 3466Freescale Layerscape Management Complex Firmware Support: 3467--------------------------------------------------------- 3468The Freescale Layerscape Management Complex (MC) supports the loading of 3469"firmware". 3470This firmware often needs to be loaded during U-Boot booting, so macros 3471are used to identify the storage device (NOR flash, SPI, etc) and the address 3472within that device. 3473 3474- CONFIG_FSL_MC_ENET 3475 Enable the MC driver for Layerscape SoCs. 3476 3477Freescale Layerscape Debug Server Support: 3478------------------------------------------- 3479The Freescale Layerscape Debug Server Support supports the loading of 3480"Debug Server firmware" and triggering SP boot-rom. 3481This firmware often needs to be loaded during U-Boot booting. 3482 3483- CONFIG_SYS_MC_RSV_MEM_ALIGN 3484 Define alignment of reserved memory MC requires 3485 3486Reproducible builds 3487------------------- 3488 3489In order to achieve reproducible builds, timestamps used in the U-Boot build 3490process have to be set to a fixed value. 3491 3492This is done using the SOURCE_DATE_EPOCH environment variable. 3493SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3494option for U-Boot or an environment variable in U-Boot. 3495 3496SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3497 3498Building the Software: 3499====================== 3500 3501Building U-Boot has been tested in several native build environments 3502and in many different cross environments. Of course we cannot support 3503all possibly existing versions of cross development tools in all 3504(potentially obsolete) versions. In case of tool chain problems we 3505recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3506which is extensively used to build and test U-Boot. 3507 3508If you are not using a native environment, it is assumed that you 3509have GNU cross compiling tools available in your path. In this case, 3510you must set the environment variable CROSS_COMPILE in your shell. 3511Note that no changes to the Makefile or any other source files are 3512necessary. For example using the ELDK on a 4xx CPU, please enter: 3513 3514 $ CROSS_COMPILE=ppc_4xx- 3515 $ export CROSS_COMPILE 3516 3517Note: If you wish to generate Windows versions of the utilities in 3518 the tools directory you can use the MinGW toolchain 3519 (http://www.mingw.org). Set your HOST tools to the MinGW 3520 toolchain and execute 'make tools'. For example: 3521 3522 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3523 3524 Binaries such as tools/mkimage.exe will be created which can 3525 be executed on computers running Windows. 3526 3527U-Boot is intended to be simple to build. After installing the 3528sources you must configure U-Boot for one specific board type. This 3529is done by typing: 3530 3531 make NAME_defconfig 3532 3533where "NAME_defconfig" is the name of one of the existing configu- 3534rations; see boards.cfg for supported names. 3535 3536Note: for some board special configuration names may exist; check if 3537 additional information is available from the board vendor; for 3538 instance, the TQM823L systems are available without (standard) 3539 or with LCD support. You can select such additional "features" 3540 when choosing the configuration, i. e. 3541 3542 make TQM823L_defconfig 3543 - will configure for a plain TQM823L, i. e. no LCD support 3544 3545 make TQM823L_LCD_defconfig 3546 - will configure for a TQM823L with U-Boot console on LCD 3547 3548 etc. 3549 3550 3551Finally, type "make all", and you should get some working U-Boot 3552images ready for download to / installation on your system: 3553 3554- "u-boot.bin" is a raw binary image 3555- "u-boot" is an image in ELF binary format 3556- "u-boot.srec" is in Motorola S-Record format 3557 3558By default the build is performed locally and the objects are saved 3559in the source directory. One of the two methods can be used to change 3560this behavior and build U-Boot to some external directory: 3561 35621. Add O= to the make command line invocations: 3563 3564 make O=/tmp/build distclean 3565 make O=/tmp/build NAME_defconfig 3566 make O=/tmp/build all 3567 35682. Set environment variable KBUILD_OUTPUT to point to the desired location: 3569 3570 export KBUILD_OUTPUT=/tmp/build 3571 make distclean 3572 make NAME_defconfig 3573 make all 3574 3575Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3576variable. 3577 3578User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3579setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3580For example to treat all compiler warnings as errors: 3581 3582 make KCFLAGS=-Werror 3583 3584Please be aware that the Makefiles assume you are using GNU make, so 3585for instance on NetBSD you might need to use "gmake" instead of 3586native "make". 3587 3588 3589If the system board that you have is not listed, then you will need 3590to port U-Boot to your hardware platform. To do this, follow these 3591steps: 3592 35931. Create a new directory to hold your board specific code. Add any 3594 files you need. In your board directory, you will need at least 3595 the "Makefile" and a "<board>.c". 35962. Create a new configuration file "include/configs/<board>.h" for 3597 your board. 35983. If you're porting U-Boot to a new CPU, then also create a new 3599 directory to hold your CPU specific code. Add any files you need. 36004. Run "make <board>_defconfig" with your new name. 36015. Type "make", and you should get a working "u-boot.srec" file 3602 to be installed on your target system. 36036. Debug and solve any problems that might arise. 3604 [Of course, this last step is much harder than it sounds.] 3605 3606 3607Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3608============================================================== 3609 3610If you have modified U-Boot sources (for instance added a new board 3611or support for new devices, a new CPU, etc.) you are expected to 3612provide feedback to the other developers. The feedback normally takes 3613the form of a "patch", i. e. a context diff against a certain (latest 3614official or latest in the git repository) version of U-Boot sources. 3615 3616But before you submit such a patch, please verify that your modifi- 3617cation did not break existing code. At least make sure that *ALL* of 3618the supported boards compile WITHOUT ANY compiler warnings. To do so, 3619just run the buildman script (tools/buildman/buildman), which will 3620configure and build U-Boot for ALL supported system. Be warned, this 3621will take a while. Please see the buildman README, or run 'buildman -H' 3622for documentation. 3623 3624 3625See also "U-Boot Porting Guide" below. 3626 3627 3628Monitor Commands - Overview: 3629============================ 3630 3631go - start application at address 'addr' 3632run - run commands in an environment variable 3633bootm - boot application image from memory 3634bootp - boot image via network using BootP/TFTP protocol 3635bootz - boot zImage from memory 3636tftpboot- boot image via network using TFTP protocol 3637 and env variables "ipaddr" and "serverip" 3638 (and eventually "gatewayip") 3639tftpput - upload a file via network using TFTP protocol 3640rarpboot- boot image via network using RARP/TFTP protocol 3641diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3642loads - load S-Record file over serial line 3643loadb - load binary file over serial line (kermit mode) 3644md - memory display 3645mm - memory modify (auto-incrementing) 3646nm - memory modify (constant address) 3647mw - memory write (fill) 3648cp - memory copy 3649cmp - memory compare 3650crc32 - checksum calculation 3651i2c - I2C sub-system 3652sspi - SPI utility commands 3653base - print or set address offset 3654printenv- print environment variables 3655setenv - set environment variables 3656saveenv - save environment variables to persistent storage 3657protect - enable or disable FLASH write protection 3658erase - erase FLASH memory 3659flinfo - print FLASH memory information 3660nand - NAND memory operations (see doc/README.nand) 3661bdinfo - print Board Info structure 3662iminfo - print header information for application image 3663coninfo - print console devices and informations 3664ide - IDE sub-system 3665loop - infinite loop on address range 3666loopw - infinite write loop on address range 3667mtest - simple RAM test 3668icache - enable or disable instruction cache 3669dcache - enable or disable data cache 3670reset - Perform RESET of the CPU 3671echo - echo args to console 3672version - print monitor version 3673help - print online help 3674? - alias for 'help' 3675 3676 3677Monitor Commands - Detailed Description: 3678======================================== 3679 3680TODO. 3681 3682For now: just type "help <command>". 3683 3684 3685Environment Variables: 3686====================== 3687 3688U-Boot supports user configuration using Environment Variables which 3689can be made persistent by saving to Flash memory. 3690 3691Environment Variables are set using "setenv", printed using 3692"printenv", and saved to Flash using "saveenv". Using "setenv" 3693without a value can be used to delete a variable from the 3694environment. As long as you don't save the environment you are 3695working with an in-memory copy. In case the Flash area containing the 3696environment is erased by accident, a default environment is provided. 3697 3698Some configuration options can be set using Environment Variables. 3699 3700List of environment variables (most likely not complete): 3701 3702 baudrate - see CONFIG_BAUDRATE 3703 3704 bootdelay - see CONFIG_BOOTDELAY 3705 3706 bootcmd - see CONFIG_BOOTCOMMAND 3707 3708 bootargs - Boot arguments when booting an RTOS image 3709 3710 bootfile - Name of the image to load with TFTP 3711 3712 bootm_low - Memory range available for image processing in the bootm 3713 command can be restricted. This variable is given as 3714 a hexadecimal number and defines lowest address allowed 3715 for use by the bootm command. See also "bootm_size" 3716 environment variable. Address defined by "bootm_low" is 3717 also the base of the initial memory mapping for the Linux 3718 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3719 bootm_mapsize. 3720 3721 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3722 This variable is given as a hexadecimal number and it 3723 defines the size of the memory region starting at base 3724 address bootm_low that is accessible by the Linux kernel 3725 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3726 as the default value if it is defined, and bootm_size is 3727 used otherwise. 3728 3729 bootm_size - Memory range available for image processing in the bootm 3730 command can be restricted. This variable is given as 3731 a hexadecimal number and defines the size of the region 3732 allowed for use by the bootm command. See also "bootm_low" 3733 environment variable. 3734 3735 updatefile - Location of the software update file on a TFTP server, used 3736 by the automatic software update feature. Please refer to 3737 documentation in doc/README.update for more details. 3738 3739 autoload - if set to "no" (any string beginning with 'n'), 3740 "bootp" will just load perform a lookup of the 3741 configuration from the BOOTP server, but not try to 3742 load any image using TFTP 3743 3744 autostart - if set to "yes", an image loaded using the "bootp", 3745 "rarpboot", "tftpboot" or "diskboot" commands will 3746 be automatically started (by internally calling 3747 "bootm") 3748 3749 If set to "no", a standalone image passed to the 3750 "bootm" command will be copied to the load address 3751 (and eventually uncompressed), but NOT be started. 3752 This can be used to load and uncompress arbitrary 3753 data. 3754 3755 fdt_high - if set this restricts the maximum address that the 3756 flattened device tree will be copied into upon boot. 3757 For example, if you have a system with 1 GB memory 3758 at physical address 0x10000000, while Linux kernel 3759 only recognizes the first 704 MB as low memory, you 3760 may need to set fdt_high as 0x3C000000 to have the 3761 device tree blob be copied to the maximum address 3762 of the 704 MB low memory, so that Linux kernel can 3763 access it during the boot procedure. 3764 3765 If this is set to the special value 0xFFFFFFFF then 3766 the fdt will not be copied at all on boot. For this 3767 to work it must reside in writable memory, have 3768 sufficient padding on the end of it for u-boot to 3769 add the information it needs into it, and the memory 3770 must be accessible by the kernel. 3771 3772 fdtcontroladdr- if set this is the address of the control flattened 3773 device tree used by U-Boot when CONFIG_OF_CONTROL is 3774 defined. 3775 3776 i2cfast - (PPC405GP|PPC405EP only) 3777 if set to 'y' configures Linux I2C driver for fast 3778 mode (400kHZ). This environment variable is used in 3779 initialization code. So, for changes to be effective 3780 it must be saved and board must be reset. 3781 3782 initrd_high - restrict positioning of initrd images: 3783 If this variable is not set, initrd images will be 3784 copied to the highest possible address in RAM; this 3785 is usually what you want since it allows for 3786 maximum initrd size. If for some reason you want to 3787 make sure that the initrd image is loaded below the 3788 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3789 variable to a value of "no" or "off" or "0". 3790 Alternatively, you can set it to a maximum upper 3791 address to use (U-Boot will still check that it 3792 does not overwrite the U-Boot stack and data). 3793 3794 For instance, when you have a system with 16 MB 3795 RAM, and want to reserve 4 MB from use by Linux, 3796 you can do this by adding "mem=12M" to the value of 3797 the "bootargs" variable. However, now you must make 3798 sure that the initrd image is placed in the first 3799 12 MB as well - this can be done with 3800 3801 setenv initrd_high 00c00000 3802 3803 If you set initrd_high to 0xFFFFFFFF, this is an 3804 indication to U-Boot that all addresses are legal 3805 for the Linux kernel, including addresses in flash 3806 memory. In this case U-Boot will NOT COPY the 3807 ramdisk at all. This may be useful to reduce the 3808 boot time on your system, but requires that this 3809 feature is supported by your Linux kernel. 3810 3811 ipaddr - IP address; needed for tftpboot command 3812 3813 loadaddr - Default load address for commands like "bootp", 3814 "rarpboot", "tftpboot", "loadb" or "diskboot" 3815 3816 loads_echo - see CONFIG_LOADS_ECHO 3817 3818 serverip - TFTP server IP address; needed for tftpboot command 3819 3820 bootretry - see CONFIG_BOOT_RETRY_TIME 3821 3822 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3823 3824 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3825 3826 ethprime - controls which interface is used first. 3827 3828 ethact - controls which interface is currently active. 3829 For example you can do the following 3830 3831 => setenv ethact FEC 3832 => ping 192.168.0.1 # traffic sent on FEC 3833 => setenv ethact SCC 3834 => ping 10.0.0.1 # traffic sent on SCC 3835 3836 ethrotate - When set to "no" U-Boot does not go through all 3837 available network interfaces. 3838 It just stays at the currently selected interface. 3839 3840 netretry - When set to "no" each network operation will 3841 either succeed or fail without retrying. 3842 When set to "once" the network operation will 3843 fail when all the available network interfaces 3844 are tried once without success. 3845 Useful on scripts which control the retry operation 3846 themselves. 3847 3848 npe_ucode - set load address for the NPE microcode 3849 3850 silent_linux - If set then Linux will be told to boot silently, by 3851 changing the console to be empty. If "yes" it will be 3852 made silent. If "no" it will not be made silent. If 3853 unset, then it will be made silent if the U-Boot console 3854 is silent. 3855 3856 tftpsrcp - If this is set, the value is used for TFTP's 3857 UDP source port. 3858 3859 tftpdstp - If this is set, the value is used for TFTP's UDP 3860 destination port instead of the Well Know Port 69. 3861 3862 tftpblocksize - Block size to use for TFTP transfers; if not set, 3863 we use the TFTP server's default block size 3864 3865 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3866 seconds, minimum value is 1000 = 1 second). Defines 3867 when a packet is considered to be lost so it has to 3868 be retransmitted. The default is 5000 = 5 seconds. 3869 Lowering this value may make downloads succeed 3870 faster in networks with high packet loss rates or 3871 with unreliable TFTP servers. 3872 3873 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3874 unit, minimum value = 0). Defines how many timeouts 3875 can happen during a single file transfer before that 3876 transfer is aborted. The default is 10, and 0 means 3877 'no timeouts allowed'. Increasing this value may help 3878 downloads succeed with high packet loss rates, or with 3879 unreliable TFTP servers or client hardware. 3880 3881 vlan - When set to a value < 4095 the traffic over 3882 Ethernet is encapsulated/received over 802.1q 3883 VLAN tagged frames. 3884 3885 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3886 Unsigned value, in milliseconds. If not set, the period will 3887 be either the default (28000), or a value based on 3888 CONFIG_NET_RETRY_COUNT, if defined. This value has 3889 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3890 3891The following image location variables contain the location of images 3892used in booting. The "Image" column gives the role of the image and is 3893not an environment variable name. The other columns are environment 3894variable names. "File Name" gives the name of the file on a TFTP 3895server, "RAM Address" gives the location in RAM the image will be 3896loaded to, and "Flash Location" gives the image's address in NOR 3897flash or offset in NAND flash. 3898 3899*Note* - these variables don't have to be defined for all boards, some 3900boards currently use other variables for these purposes, and some 3901boards use these variables for other purposes. 3902 3903Image File Name RAM Address Flash Location 3904----- --------- ----------- -------------- 3905u-boot u-boot u-boot_addr_r u-boot_addr 3906Linux kernel bootfile kernel_addr_r kernel_addr 3907device tree blob fdtfile fdt_addr_r fdt_addr 3908ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3909 3910The following environment variables may be used and automatically 3911updated by the network boot commands ("bootp" and "rarpboot"), 3912depending the information provided by your boot server: 3913 3914 bootfile - see above 3915 dnsip - IP address of your Domain Name Server 3916 dnsip2 - IP address of your secondary Domain Name Server 3917 gatewayip - IP address of the Gateway (Router) to use 3918 hostname - Target hostname 3919 ipaddr - see above 3920 netmask - Subnet Mask 3921 rootpath - Pathname of the root filesystem on the NFS server 3922 serverip - see above 3923 3924 3925There are two special Environment Variables: 3926 3927 serial# - contains hardware identification information such 3928 as type string and/or serial number 3929 ethaddr - Ethernet address 3930 3931These variables can be set only once (usually during manufacturing of 3932the board). U-Boot refuses to delete or overwrite these variables 3933once they have been set once. 3934 3935 3936Further special Environment Variables: 3937 3938 ver - Contains the U-Boot version string as printed 3939 with the "version" command. This variable is 3940 readonly (see CONFIG_VERSION_VARIABLE). 3941 3942 3943Please note that changes to some configuration parameters may take 3944only effect after the next boot (yes, that's just like Windoze :-). 3945 3946 3947Callback functions for environment variables: 3948--------------------------------------------- 3949 3950For some environment variables, the behavior of u-boot needs to change 3951when their values are changed. This functionality allows functions to 3952be associated with arbitrary variables. On creation, overwrite, or 3953deletion, the callback will provide the opportunity for some side 3954effect to happen or for the change to be rejected. 3955 3956The callbacks are named and associated with a function using the 3957U_BOOT_ENV_CALLBACK macro in your board or driver code. 3958 3959These callbacks are associated with variables in one of two ways. The 3960static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3961in the board configuration to a string that defines a list of 3962associations. The list must be in the following format: 3963 3964 entry = variable_name[:callback_name] 3965 list = entry[,list] 3966 3967If the callback name is not specified, then the callback is deleted. 3968Spaces are also allowed anywhere in the list. 3969 3970Callbacks can also be associated by defining the ".callbacks" variable 3971with the same list format above. Any association in ".callbacks" will 3972override any association in the static list. You can define 3973CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 3974".callbacks" environment variable in the default or embedded environment. 3975 3976If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3977regular expression. This allows multiple variables to be connected to 3978the same callback without explicitly listing them all out. 3979 3980 3981Command Line Parsing: 3982===================== 3983 3984There are two different command line parsers available with U-Boot: 3985the old "simple" one, and the much more powerful "hush" shell: 3986 3987Old, simple command line parser: 3988-------------------------------- 3989 3990- supports environment variables (through setenv / saveenv commands) 3991- several commands on one line, separated by ';' 3992- variable substitution using "... ${name} ..." syntax 3993- special characters ('$', ';') can be escaped by prefixing with '\', 3994 for example: 3995 setenv bootcmd bootm \${address} 3996- You can also escape text by enclosing in single apostrophes, for example: 3997 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 3998 3999Hush shell: 4000----------- 4001 4002- similar to Bourne shell, with control structures like 4003 if...then...else...fi, for...do...done; while...do...done, 4004 until...do...done, ... 4005- supports environment ("global") variables (through setenv / saveenv 4006 commands) and local shell variables (through standard shell syntax 4007 "name=value"); only environment variables can be used with "run" 4008 command 4009 4010General rules: 4011-------------- 4012 4013(1) If a command line (or an environment variable executed by a "run" 4014 command) contains several commands separated by semicolon, and 4015 one of these commands fails, then the remaining commands will be 4016 executed anyway. 4017 4018(2) If you execute several variables with one call to run (i. e. 4019 calling run with a list of variables as arguments), any failing 4020 command will cause "run" to terminate, i. e. the remaining 4021 variables are not executed. 4022 4023Note for Redundant Ethernet Interfaces: 4024======================================= 4025 4026Some boards come with redundant Ethernet interfaces; U-Boot supports 4027such configurations and is capable of automatic selection of a 4028"working" interface when needed. MAC assignment works as follows: 4029 4030Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4031MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4032"eth1addr" (=>eth1), "eth2addr", ... 4033 4034If the network interface stores some valid MAC address (for instance 4035in SROM), this is used as default address if there is NO correspon- 4036ding setting in the environment; if the corresponding environment 4037variable is set, this overrides the settings in the card; that means: 4038 4039o If the SROM has a valid MAC address, and there is no address in the 4040 environment, the SROM's address is used. 4041 4042o If there is no valid address in the SROM, and a definition in the 4043 environment exists, then the value from the environment variable is 4044 used. 4045 4046o If both the SROM and the environment contain a MAC address, and 4047 both addresses are the same, this MAC address is used. 4048 4049o If both the SROM and the environment contain a MAC address, and the 4050 addresses differ, the value from the environment is used and a 4051 warning is printed. 4052 4053o If neither SROM nor the environment contain a MAC address, an error 4054 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4055 a random, locally-assigned MAC is used. 4056 4057If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4058will be programmed into hardware as part of the initialization process. This 4059may be skipped by setting the appropriate 'ethmacskip' environment variable. 4060The naming convention is as follows: 4061"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4062 4063Image Formats: 4064============== 4065 4066U-Boot is capable of booting (and performing other auxiliary operations on) 4067images in two formats: 4068 4069New uImage format (FIT) 4070----------------------- 4071 4072Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4073to Flattened Device Tree). It allows the use of images with multiple 4074components (several kernels, ramdisks, etc.), with contents protected by 4075SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4076 4077 4078Old uImage format 4079----------------- 4080 4081Old image format is based on binary files which can be basically anything, 4082preceded by a special header; see the definitions in include/image.h for 4083details; basically, the header defines the following image properties: 4084 4085* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4086 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4087 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4088 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4089 INTEGRITY). 4090* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4091 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4092 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4093* Compression Type (uncompressed, gzip, bzip2) 4094* Load Address 4095* Entry Point 4096* Image Name 4097* Image Timestamp 4098 4099The header is marked by a special Magic Number, and both the header 4100and the data portions of the image are secured against corruption by 4101CRC32 checksums. 4102 4103 4104Linux Support: 4105============== 4106 4107Although U-Boot should support any OS or standalone application 4108easily, the main focus has always been on Linux during the design of 4109U-Boot. 4110 4111U-Boot includes many features that so far have been part of some 4112special "boot loader" code within the Linux kernel. Also, any 4113"initrd" images to be used are no longer part of one big Linux image; 4114instead, kernel and "initrd" are separate images. This implementation 4115serves several purposes: 4116 4117- the same features can be used for other OS or standalone 4118 applications (for instance: using compressed images to reduce the 4119 Flash memory footprint) 4120 4121- it becomes much easier to port new Linux kernel versions because 4122 lots of low-level, hardware dependent stuff are done by U-Boot 4123 4124- the same Linux kernel image can now be used with different "initrd" 4125 images; of course this also means that different kernel images can 4126 be run with the same "initrd". This makes testing easier (you don't 4127 have to build a new "zImage.initrd" Linux image when you just 4128 change a file in your "initrd"). Also, a field-upgrade of the 4129 software is easier now. 4130 4131 4132Linux HOWTO: 4133============ 4134 4135Porting Linux to U-Boot based systems: 4136--------------------------------------- 4137 4138U-Boot cannot save you from doing all the necessary modifications to 4139configure the Linux device drivers for use with your target hardware 4140(no, we don't intend to provide a full virtual machine interface to 4141Linux :-). 4142 4143But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4144 4145Just make sure your machine specific header file (for instance 4146include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4147Information structure as we define in include/asm-<arch>/u-boot.h, 4148and make sure that your definition of IMAP_ADDR uses the same value 4149as your U-Boot configuration in CONFIG_SYS_IMMR. 4150 4151Note that U-Boot now has a driver model, a unified model for drivers. 4152If you are adding a new driver, plumb it into driver model. If there 4153is no uclass available, you are encouraged to create one. See 4154doc/driver-model. 4155 4156 4157Configuring the Linux kernel: 4158----------------------------- 4159 4160No specific requirements for U-Boot. Make sure you have some root 4161device (initial ramdisk, NFS) for your target system. 4162 4163 4164Building a Linux Image: 4165----------------------- 4166 4167With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4168not used. If you use recent kernel source, a new build target 4169"uImage" will exist which automatically builds an image usable by 4170U-Boot. Most older kernels also have support for a "pImage" target, 4171which was introduced for our predecessor project PPCBoot and uses a 4172100% compatible format. 4173 4174Example: 4175 4176 make TQM850L_defconfig 4177 make oldconfig 4178 make dep 4179 make uImage 4180 4181The "uImage" build target uses a special tool (in 'tools/mkimage') to 4182encapsulate a compressed Linux kernel image with header information, 4183CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4184 4185* build a standard "vmlinux" kernel image (in ELF binary format): 4186 4187* convert the kernel into a raw binary image: 4188 4189 ${CROSS_COMPILE}-objcopy -O binary \ 4190 -R .note -R .comment \ 4191 -S vmlinux linux.bin 4192 4193* compress the binary image: 4194 4195 gzip -9 linux.bin 4196 4197* package compressed binary image for U-Boot: 4198 4199 mkimage -A ppc -O linux -T kernel -C gzip \ 4200 -a 0 -e 0 -n "Linux Kernel Image" \ 4201 -d linux.bin.gz uImage 4202 4203 4204The "mkimage" tool can also be used to create ramdisk images for use 4205with U-Boot, either separated from the Linux kernel image, or 4206combined into one file. "mkimage" encapsulates the images with a 64 4207byte header containing information about target architecture, 4208operating system, image type, compression method, entry points, time 4209stamp, CRC32 checksums, etc. 4210 4211"mkimage" can be called in two ways: to verify existing images and 4212print the header information, or to build new images. 4213 4214In the first form (with "-l" option) mkimage lists the information 4215contained in the header of an existing U-Boot image; this includes 4216checksum verification: 4217 4218 tools/mkimage -l image 4219 -l ==> list image header information 4220 4221The second form (with "-d" option) is used to build a U-Boot image 4222from a "data file" which is used as image payload: 4223 4224 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4225 -n name -d data_file image 4226 -A ==> set architecture to 'arch' 4227 -O ==> set operating system to 'os' 4228 -T ==> set image type to 'type' 4229 -C ==> set compression type 'comp' 4230 -a ==> set load address to 'addr' (hex) 4231 -e ==> set entry point to 'ep' (hex) 4232 -n ==> set image name to 'name' 4233 -d ==> use image data from 'datafile' 4234 4235Right now, all Linux kernels for PowerPC systems use the same load 4236address (0x00000000), but the entry point address depends on the 4237kernel version: 4238 4239- 2.2.x kernels have the entry point at 0x0000000C, 4240- 2.3.x and later kernels have the entry point at 0x00000000. 4241 4242So a typical call to build a U-Boot image would read: 4243 4244 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4245 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4246 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4247 > examples/uImage.TQM850L 4248 Image Name: 2.4.4 kernel for TQM850L 4249 Created: Wed Jul 19 02:34:59 2000 4250 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4251 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4252 Load Address: 0x00000000 4253 Entry Point: 0x00000000 4254 4255To verify the contents of the image (or check for corruption): 4256 4257 -> tools/mkimage -l examples/uImage.TQM850L 4258 Image Name: 2.4.4 kernel for TQM850L 4259 Created: Wed Jul 19 02:34:59 2000 4260 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4261 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4262 Load Address: 0x00000000 4263 Entry Point: 0x00000000 4264 4265NOTE: for embedded systems where boot time is critical you can trade 4266speed for memory and install an UNCOMPRESSED image instead: this 4267needs more space in Flash, but boots much faster since it does not 4268need to be uncompressed: 4269 4270 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4271 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4272 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4273 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4274 > examples/uImage.TQM850L-uncompressed 4275 Image Name: 2.4.4 kernel for TQM850L 4276 Created: Wed Jul 19 02:34:59 2000 4277 Image Type: PowerPC Linux Kernel Image (uncompressed) 4278 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4279 Load Address: 0x00000000 4280 Entry Point: 0x00000000 4281 4282 4283Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4284when your kernel is intended to use an initial ramdisk: 4285 4286 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4287 > -A ppc -O linux -T ramdisk -C gzip \ 4288 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4289 Image Name: Simple Ramdisk Image 4290 Created: Wed Jan 12 14:01:50 2000 4291 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4292 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4293 Load Address: 0x00000000 4294 Entry Point: 0x00000000 4295 4296The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4297option performs the converse operation of the mkimage's second form (the "-d" 4298option). Given an image built by mkimage, the dumpimage extracts a "data file" 4299from the image: 4300 4301 tools/dumpimage -i image -T type -p position data_file 4302 -i ==> extract from the 'image' a specific 'data_file' 4303 -T ==> set image type to 'type' 4304 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4305 4306 4307Installing a Linux Image: 4308------------------------- 4309 4310To downloading a U-Boot image over the serial (console) interface, 4311you must convert the image to S-Record format: 4312 4313 objcopy -I binary -O srec examples/image examples/image.srec 4314 4315The 'objcopy' does not understand the information in the U-Boot 4316image header, so the resulting S-Record file will be relative to 4317address 0x00000000. To load it to a given address, you need to 4318specify the target address as 'offset' parameter with the 'loads' 4319command. 4320 4321Example: install the image to address 0x40100000 (which on the 4322TQM8xxL is in the first Flash bank): 4323 4324 => erase 40100000 401FFFFF 4325 4326 .......... done 4327 Erased 8 sectors 4328 4329 => loads 40100000 4330 ## Ready for S-Record download ... 4331 ~>examples/image.srec 4332 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4333 ... 4334 15989 15990 15991 15992 4335 [file transfer complete] 4336 [connected] 4337 ## Start Addr = 0x00000000 4338 4339 4340You can check the success of the download using the 'iminfo' command; 4341this includes a checksum verification so you can be sure no data 4342corruption happened: 4343 4344 => imi 40100000 4345 4346 ## Checking Image at 40100000 ... 4347 Image Name: 2.2.13 for initrd on TQM850L 4348 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4349 Data Size: 335725 Bytes = 327 kB = 0 MB 4350 Load Address: 00000000 4351 Entry Point: 0000000c 4352 Verifying Checksum ... OK 4353 4354 4355Boot Linux: 4356----------- 4357 4358The "bootm" command is used to boot an application that is stored in 4359memory (RAM or Flash). In case of a Linux kernel image, the contents 4360of the "bootargs" environment variable is passed to the kernel as 4361parameters. You can check and modify this variable using the 4362"printenv" and "setenv" commands: 4363 4364 4365 => printenv bootargs 4366 bootargs=root=/dev/ram 4367 4368 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4369 4370 => printenv bootargs 4371 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4372 4373 => bootm 40020000 4374 ## Booting Linux kernel at 40020000 ... 4375 Image Name: 2.2.13 for NFS on TQM850L 4376 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4377 Data Size: 381681 Bytes = 372 kB = 0 MB 4378 Load Address: 00000000 4379 Entry Point: 0000000c 4380 Verifying Checksum ... OK 4381 Uncompressing Kernel Image ... OK 4382 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 4383 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4384 time_init: decrementer frequency = 187500000/60 4385 Calibrating delay loop... 49.77 BogoMIPS 4386 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4387 ... 4388 4389If you want to boot a Linux kernel with initial RAM disk, you pass 4390the memory addresses of both the kernel and the initrd image (PPBCOOT 4391format!) to the "bootm" command: 4392 4393 => imi 40100000 40200000 4394 4395 ## Checking Image at 40100000 ... 4396 Image Name: 2.2.13 for initrd on TQM850L 4397 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4398 Data Size: 335725 Bytes = 327 kB = 0 MB 4399 Load Address: 00000000 4400 Entry Point: 0000000c 4401 Verifying Checksum ... OK 4402 4403 ## Checking Image at 40200000 ... 4404 Image Name: Simple Ramdisk Image 4405 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4406 Data Size: 566530 Bytes = 553 kB = 0 MB 4407 Load Address: 00000000 4408 Entry Point: 00000000 4409 Verifying Checksum ... OK 4410 4411 => bootm 40100000 40200000 4412 ## Booting Linux kernel at 40100000 ... 4413 Image Name: 2.2.13 for initrd on TQM850L 4414 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4415 Data Size: 335725 Bytes = 327 kB = 0 MB 4416 Load Address: 00000000 4417 Entry Point: 0000000c 4418 Verifying Checksum ... OK 4419 Uncompressing Kernel Image ... OK 4420 ## Loading RAMDisk Image at 40200000 ... 4421 Image Name: Simple Ramdisk Image 4422 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4423 Data Size: 566530 Bytes = 553 kB = 0 MB 4424 Load Address: 00000000 4425 Entry Point: 00000000 4426 Verifying Checksum ... OK 4427 Loading Ramdisk ... OK 4428 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 4429 Boot arguments: root=/dev/ram 4430 time_init: decrementer frequency = 187500000/60 4431 Calibrating delay loop... 49.77 BogoMIPS 4432 ... 4433 RAMDISK: Compressed image found at block 0 4434 VFS: Mounted root (ext2 filesystem). 4435 4436 bash# 4437 4438Boot Linux and pass a flat device tree: 4439----------- 4440 4441First, U-Boot must be compiled with the appropriate defines. See the section 4442titled "Linux Kernel Interface" above for a more in depth explanation. The 4443following is an example of how to start a kernel and pass an updated 4444flat device tree: 4445 4446=> print oftaddr 4447oftaddr=0x300000 4448=> print oft 4449oft=oftrees/mpc8540ads.dtb 4450=> tftp $oftaddr $oft 4451Speed: 1000, full duplex 4452Using TSEC0 device 4453TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4454Filename 'oftrees/mpc8540ads.dtb'. 4455Load address: 0x300000 4456Loading: # 4457done 4458Bytes transferred = 4106 (100a hex) 4459=> tftp $loadaddr $bootfile 4460Speed: 1000, full duplex 4461Using TSEC0 device 4462TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4463Filename 'uImage'. 4464Load address: 0x200000 4465Loading:############ 4466done 4467Bytes transferred = 1029407 (fb51f hex) 4468=> print loadaddr 4469loadaddr=200000 4470=> print oftaddr 4471oftaddr=0x300000 4472=> bootm $loadaddr - $oftaddr 4473## Booting image at 00200000 ... 4474 Image Name: Linux-2.6.17-dirty 4475 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4476 Data Size: 1029343 Bytes = 1005.2 kB 4477 Load Address: 00000000 4478 Entry Point: 00000000 4479 Verifying Checksum ... OK 4480 Uncompressing Kernel Image ... OK 4481Booting using flat device tree at 0x300000 4482Using MPC85xx ADS machine description 4483Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4484[snip] 4485 4486 4487More About U-Boot Image Types: 4488------------------------------ 4489 4490U-Boot supports the following image types: 4491 4492 "Standalone Programs" are directly runnable in the environment 4493 provided by U-Boot; it is expected that (if they behave 4494 well) you can continue to work in U-Boot after return from 4495 the Standalone Program. 4496 "OS Kernel Images" are usually images of some Embedded OS which 4497 will take over control completely. Usually these programs 4498 will install their own set of exception handlers, device 4499 drivers, set up the MMU, etc. - this means, that you cannot 4500 expect to re-enter U-Boot except by resetting the CPU. 4501 "RAMDisk Images" are more or less just data blocks, and their 4502 parameters (address, size) are passed to an OS kernel that is 4503 being started. 4504 "Multi-File Images" contain several images, typically an OS 4505 (Linux) kernel image and one or more data images like 4506 RAMDisks. This construct is useful for instance when you want 4507 to boot over the network using BOOTP etc., where the boot 4508 server provides just a single image file, but you want to get 4509 for instance an OS kernel and a RAMDisk image. 4510 4511 "Multi-File Images" start with a list of image sizes, each 4512 image size (in bytes) specified by an "uint32_t" in network 4513 byte order. This list is terminated by an "(uint32_t)0". 4514 Immediately after the terminating 0 follow the images, one by 4515 one, all aligned on "uint32_t" boundaries (size rounded up to 4516 a multiple of 4 bytes). 4517 4518 "Firmware Images" are binary images containing firmware (like 4519 U-Boot or FPGA images) which usually will be programmed to 4520 flash memory. 4521 4522 "Script files" are command sequences that will be executed by 4523 U-Boot's command interpreter; this feature is especially 4524 useful when you configure U-Boot to use a real shell (hush) 4525 as command interpreter. 4526 4527Booting the Linux zImage: 4528------------------------- 4529 4530On some platforms, it's possible to boot Linux zImage. This is done 4531using the "bootz" command. The syntax of "bootz" command is the same 4532as the syntax of "bootm" command. 4533 4534Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4535kernel with raw initrd images. The syntax is slightly different, the 4536address of the initrd must be augmented by it's size, in the following 4537format: "<initrd addres>:<initrd size>". 4538 4539 4540Standalone HOWTO: 4541================= 4542 4543One of the features of U-Boot is that you can dynamically load and 4544run "standalone" applications, which can use some resources of 4545U-Boot like console I/O functions or interrupt services. 4546 4547Two simple examples are included with the sources: 4548 4549"Hello World" Demo: 4550------------------- 4551 4552'examples/hello_world.c' contains a small "Hello World" Demo 4553application; it is automatically compiled when you build U-Boot. 4554It's configured to run at address 0x00040004, so you can play with it 4555like that: 4556 4557 => loads 4558 ## Ready for S-Record download ... 4559 ~>examples/hello_world.srec 4560 1 2 3 4 5 6 7 8 9 10 11 ... 4561 [file transfer complete] 4562 [connected] 4563 ## Start Addr = 0x00040004 4564 4565 => go 40004 Hello World! This is a test. 4566 ## Starting application at 0x00040004 ... 4567 Hello World 4568 argc = 7 4569 argv[0] = "40004" 4570 argv[1] = "Hello" 4571 argv[2] = "World!" 4572 argv[3] = "This" 4573 argv[4] = "is" 4574 argv[5] = "a" 4575 argv[6] = "test." 4576 argv[7] = "<NULL>" 4577 Hit any key to exit ... 4578 4579 ## Application terminated, rc = 0x0 4580 4581Another example, which demonstrates how to register a CPM interrupt 4582handler with the U-Boot code, can be found in 'examples/timer.c'. 4583Here, a CPM timer is set up to generate an interrupt every second. 4584The interrupt service routine is trivial, just printing a '.' 4585character, but this is just a demo program. The application can be 4586controlled by the following keys: 4587 4588 ? - print current values og the CPM Timer registers 4589 b - enable interrupts and start timer 4590 e - stop timer and disable interrupts 4591 q - quit application 4592 4593 => loads 4594 ## Ready for S-Record download ... 4595 ~>examples/timer.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 4602 ## Starting application at 0x00040004 ... 4603 TIMERS=0xfff00980 4604 Using timer 1 4605 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4606 4607Hit 'b': 4608 [q, b, e, ?] Set interval 1000000 us 4609 Enabling timer 4610Hit '?': 4611 [q, b, e, ?] ........ 4612 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4613Hit '?': 4614 [q, b, e, ?] . 4615 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4616Hit '?': 4617 [q, b, e, ?] . 4618 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4619Hit '?': 4620 [q, b, e, ?] . 4621 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4622Hit 'e': 4623 [q, b, e, ?] ...Stopping timer 4624Hit 'q': 4625 [q, b, e, ?] ## Application terminated, rc = 0x0 4626 4627 4628Minicom warning: 4629================ 4630 4631Over time, many people have reported problems when trying to use the 4632"minicom" terminal emulation program for serial download. I (wd) 4633consider minicom to be broken, and recommend not to use it. Under 4634Unix, I recommend to use C-Kermit for general purpose use (and 4635especially for kermit binary protocol download ("loadb" command), and 4636use "cu" for S-Record download ("loads" command). See 4637http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4638for help with kermit. 4639 4640 4641Nevertheless, if you absolutely want to use it try adding this 4642configuration to your "File transfer protocols" section: 4643 4644 Name Program Name U/D FullScr IO-Red. Multi 4645 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4646 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4647 4648 4649NetBSD Notes: 4650============= 4651 4652Starting at version 0.9.2, U-Boot supports NetBSD both as host 4653(build U-Boot) and target system (boots NetBSD/mpc8xx). 4654 4655Building requires a cross environment; it is known to work on 4656NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4657need gmake since the Makefiles are not compatible with BSD make). 4658Note that the cross-powerpc package does not install include files; 4659attempting to build U-Boot will fail because <machine/ansi.h> is 4660missing. This file has to be installed and patched manually: 4661 4662 # cd /usr/pkg/cross/powerpc-netbsd/include 4663 # mkdir powerpc 4664 # ln -s powerpc machine 4665 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4666 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4667 4668Native builds *don't* work due to incompatibilities between native 4669and U-Boot include files. 4670 4671Booting assumes that (the first part of) the image booted is a 4672stage-2 loader which in turn loads and then invokes the kernel 4673proper. Loader sources will eventually appear in the NetBSD source 4674tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4675meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4676 4677 4678Implementation Internals: 4679========================= 4680 4681The following is not intended to be a complete description of every 4682implementation detail. However, it should help to understand the 4683inner workings of U-Boot and make it easier to port it to custom 4684hardware. 4685 4686 4687Initial Stack, Global Data: 4688--------------------------- 4689 4690The implementation of U-Boot is complicated by the fact that U-Boot 4691starts running out of ROM (flash memory), usually without access to 4692system RAM (because the memory controller is not initialized yet). 4693This means that we don't have writable Data or BSS segments, and BSS 4694is not initialized as zero. To be able to get a C environment working 4695at all, we have to allocate at least a minimal stack. Implementation 4696options for this are defined and restricted by the CPU used: Some CPU 4697models provide on-chip memory (like the IMMR area on MPC8xx and 4698MPC826x processors), on others (parts of) the data cache can be 4699locked as (mis-) used as memory, etc. 4700 4701 Chris Hallinan posted a good summary of these issues to the 4702 U-Boot mailing list: 4703 4704 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4705 From: "Chris Hallinan" <clh@net1plus.com> 4706 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4707 ... 4708 4709 Correct me if I'm wrong, folks, but the way I understand it 4710 is this: Using DCACHE as initial RAM for Stack, etc, does not 4711 require any physical RAM backing up the cache. The cleverness 4712 is that the cache is being used as a temporary supply of 4713 necessary storage before the SDRAM controller is setup. It's 4714 beyond the scope of this list to explain the details, but you 4715 can see how this works by studying the cache architecture and 4716 operation in the architecture and processor-specific manuals. 4717 4718 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4719 is another option for the system designer to use as an 4720 initial stack/RAM area prior to SDRAM being available. Either 4721 option should work for you. Using CS 4 should be fine if your 4722 board designers haven't used it for something that would 4723 cause you grief during the initial boot! It is frequently not 4724 used. 4725 4726 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4727 with your processor/board/system design. The default value 4728 you will find in any recent u-boot distribution in 4729 walnut.h should work for you. I'd set it to a value larger 4730 than your SDRAM module. If you have a 64MB SDRAM module, set 4731 it above 400_0000. Just make sure your board has no resources 4732 that are supposed to respond to that address! That code in 4733 start.S has been around a while and should work as is when 4734 you get the config right. 4735 4736 -Chris Hallinan 4737 DS4.COM, Inc. 4738 4739It is essential to remember this, since it has some impact on the C 4740code for the initialization procedures: 4741 4742* Initialized global data (data segment) is read-only. Do not attempt 4743 to write it. 4744 4745* Do not use any uninitialized global data (or implicitly initialized 4746 as zero data - BSS segment) at all - this is undefined, initiali- 4747 zation is performed later (when relocating to RAM). 4748 4749* Stack space is very limited. Avoid big data buffers or things like 4750 that. 4751 4752Having only the stack as writable memory limits means we cannot use 4753normal global data to share information between the code. But it 4754turned out that the implementation of U-Boot can be greatly 4755simplified by making a global data structure (gd_t) available to all 4756functions. We could pass a pointer to this data as argument to _all_ 4757functions, but this would bloat the code. Instead we use a feature of 4758the GCC compiler (Global Register Variables) to share the data: we 4759place a pointer (gd) to the global data into a register which we 4760reserve for this purpose. 4761 4762When choosing a register for such a purpose we are restricted by the 4763relevant (E)ABI specifications for the current architecture, and by 4764GCC's implementation. 4765 4766For PowerPC, the following registers have specific use: 4767 R1: stack pointer 4768 R2: reserved for system use 4769 R3-R4: parameter passing and return values 4770 R5-R10: parameter passing 4771 R13: small data area pointer 4772 R30: GOT pointer 4773 R31: frame pointer 4774 4775 (U-Boot also uses R12 as internal GOT pointer. r12 4776 is a volatile register so r12 needs to be reset when 4777 going back and forth between asm and C) 4778 4779 ==> U-Boot will use R2 to hold a pointer to the global data 4780 4781 Note: on PPC, we could use a static initializer (since the 4782 address of the global data structure is known at compile time), 4783 but it turned out that reserving a register results in somewhat 4784 smaller code - although the code savings are not that big (on 4785 average for all boards 752 bytes for the whole U-Boot image, 4786 624 text + 127 data). 4787 4788On ARM, the following registers are used: 4789 4790 R0: function argument word/integer result 4791 R1-R3: function argument word 4792 R9: platform specific 4793 R10: stack limit (used only if stack checking is enabled) 4794 R11: argument (frame) pointer 4795 R12: temporary workspace 4796 R13: stack pointer 4797 R14: link register 4798 R15: program counter 4799 4800 ==> U-Boot will use R9 to hold a pointer to the global data 4801 4802 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4803 4804On Nios II, the ABI is documented here: 4805 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4806 4807 ==> U-Boot will use gp to hold a pointer to the global data 4808 4809 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4810 to access small data sections, so gp is free. 4811 4812On NDS32, the following registers are used: 4813 4814 R0-R1: argument/return 4815 R2-R5: argument 4816 R15: temporary register for assembler 4817 R16: trampoline register 4818 R28: frame pointer (FP) 4819 R29: global pointer (GP) 4820 R30: link register (LP) 4821 R31: stack pointer (SP) 4822 PC: program counter (PC) 4823 4824 ==> U-Boot will use R10 to hold a pointer to the global data 4825 4826NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4827or current versions of GCC may "optimize" the code too much. 4828 4829On RISC-V, the following registers are used: 4830 4831 x0: hard-wired zero (zero) 4832 x1: return address (ra) 4833 x2: stack pointer (sp) 4834 x3: global pointer (gp) 4835 x4: thread pointer (tp) 4836 x5: link register (t0) 4837 x8: frame pointer (fp) 4838 x10-x11: arguments/return values (a0-1) 4839 x12-x17: arguments (a2-7) 4840 x28-31: temporaries (t3-6) 4841 pc: program counter (pc) 4842 4843 ==> U-Boot will use gp to hold a pointer to the global data 4844 4845Memory Management: 4846------------------ 4847 4848U-Boot runs in system state and uses physical addresses, i.e. the 4849MMU is not used either for address mapping nor for memory protection. 4850 4851The available memory is mapped to fixed addresses using the memory 4852controller. In this process, a contiguous block is formed for each 4853memory type (Flash, SDRAM, SRAM), even when it consists of several 4854physical memory banks. 4855 4856U-Boot is installed in the first 128 kB of the first Flash bank (on 4857TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4858booting and sizing and initializing DRAM, the code relocates itself 4859to the upper end of DRAM. Immediately below the U-Boot code some 4860memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4861configuration setting]. Below that, a structure with global Board 4862Info data is placed, followed by the stack (growing downward). 4863 4864Additionally, some exception handler code is copied to the low 8 kB 4865of DRAM (0x00000000 ... 0x00001FFF). 4866 4867So a typical memory configuration with 16 MB of DRAM could look like 4868this: 4869 4870 0x0000 0000 Exception Vector code 4871 : 4872 0x0000 1FFF 4873 0x0000 2000 Free for Application Use 4874 : 4875 : 4876 4877 : 4878 : 4879 0x00FB FF20 Monitor Stack (Growing downward) 4880 0x00FB FFAC Board Info Data and permanent copy of global data 4881 0x00FC 0000 Malloc Arena 4882 : 4883 0x00FD FFFF 4884 0x00FE 0000 RAM Copy of Monitor Code 4885 ... eventually: LCD or video framebuffer 4886 ... eventually: pRAM (Protected RAM - unchanged by reset) 4887 0x00FF FFFF [End of RAM] 4888 4889 4890System Initialization: 4891---------------------- 4892 4893In the reset configuration, U-Boot starts at the reset entry point 4894(on most PowerPC systems at address 0x00000100). Because of the reset 4895configuration for CS0# this is a mirror of the on board Flash memory. 4896To be able to re-map memory U-Boot then jumps to its link address. 4897To be able to implement the initialization code in C, a (small!) 4898initial stack is set up in the internal Dual Ported RAM (in case CPUs 4899which provide such a feature like), or in a locked part of the data 4900cache. After that, U-Boot initializes the CPU core, the caches and 4901the SIU. 4902 4903Next, all (potentially) available memory banks are mapped using a 4904preliminary mapping. For example, we put them on 512 MB boundaries 4905(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4906on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4907programmed for SDRAM access. Using the temporary configuration, a 4908simple memory test is run that determines the size of the SDRAM 4909banks. 4910 4911When there is more than one SDRAM bank, and the banks are of 4912different size, the largest is mapped first. For equal size, the first 4913bank (CS2#) is mapped first. The first mapping is always for address 49140x00000000, with any additional banks following immediately to create 4915contiguous memory starting from 0. 4916 4917Then, the monitor installs itself at the upper end of the SDRAM area 4918and allocates memory for use by malloc() and for the global Board 4919Info data; also, the exception vector code is copied to the low RAM 4920pages, and the final stack is set up. 4921 4922Only after this relocation will you have a "normal" C environment; 4923until that you are restricted in several ways, mostly because you are 4924running from ROM, and because the code will have to be relocated to a 4925new address in RAM. 4926 4927 4928U-Boot Porting Guide: 4929---------------------- 4930 4931[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4932list, October 2002] 4933 4934 4935int main(int argc, char *argv[]) 4936{ 4937 sighandler_t no_more_time; 4938 4939 signal(SIGALRM, no_more_time); 4940 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4941 4942 if (available_money > available_manpower) { 4943 Pay consultant to port U-Boot; 4944 return 0; 4945 } 4946 4947 Download latest U-Boot source; 4948 4949 Subscribe to u-boot mailing list; 4950 4951 if (clueless) 4952 email("Hi, I am new to U-Boot, how do I get started?"); 4953 4954 while (learning) { 4955 Read the README file in the top level directory; 4956 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4957 Read applicable doc/*.README; 4958 Read the source, Luke; 4959 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4960 } 4961 4962 if (available_money > toLocalCurrency ($2500)) 4963 Buy a BDI3000; 4964 else 4965 Add a lot of aggravation and time; 4966 4967 if (a similar board exists) { /* hopefully... */ 4968 cp -a board/<similar> board/<myboard> 4969 cp include/configs/<similar>.h include/configs/<myboard>.h 4970 } else { 4971 Create your own board support subdirectory; 4972 Create your own board include/configs/<myboard>.h file; 4973 } 4974 Edit new board/<myboard> files 4975 Edit new include/configs/<myboard>.h 4976 4977 while (!accepted) { 4978 while (!running) { 4979 do { 4980 Add / modify source code; 4981 } until (compiles); 4982 Debug; 4983 if (clueless) 4984 email("Hi, I am having problems..."); 4985 } 4986 Send patch file to the U-Boot email list; 4987 if (reasonable critiques) 4988 Incorporate improvements from email list code review; 4989 else 4990 Defend code as written; 4991 } 4992 4993 return 0; 4994} 4995 4996void no_more_time (int sig) 4997{ 4998 hire_a_guru(); 4999} 5000 5001 5002Coding Standards: 5003----------------- 5004 5005All contributions to U-Boot should conform to the Linux kernel 5006coding style; see the kernel coding style guide at 5007https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 5008script "scripts/Lindent" in your Linux kernel source directory. 5009 5010Source files originating from a different project (for example the 5011MTD subsystem) are generally exempt from these guidelines and are not 5012reformatted to ease subsequent migration to newer versions of those 5013sources. 5014 5015Please note that U-Boot is implemented in C (and to some small parts in 5016Assembler); no C++ is used, so please do not use C++ style comments (//) 5017in your code. 5018 5019Please also stick to the following formatting rules: 5020- remove any trailing white space 5021- use TAB characters for indentation and vertical alignment, not spaces 5022- make sure NOT to use DOS '\r\n' line feeds 5023- do not add more than 2 consecutive empty lines to source files 5024- do not add trailing empty lines to source files 5025 5026Submissions which do not conform to the standards may be returned 5027with a request to reformat the changes. 5028 5029 5030Submitting Patches: 5031------------------- 5032 5033Since the number of patches for U-Boot is growing, we need to 5034establish some rules. Submissions which do not conform to these rules 5035may be rejected, even when they contain important and valuable stuff. 5036 5037Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5038 5039Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5040see https://lists.denx.de/listinfo/u-boot 5041 5042When you send a patch, please include the following information with 5043it: 5044 5045* For bug fixes: a description of the bug and how your patch fixes 5046 this bug. Please try to include a way of demonstrating that the 5047 patch actually fixes something. 5048 5049* For new features: a description of the feature and your 5050 implementation. 5051 5052* A CHANGELOG entry as plaintext (separate from the patch) 5053 5054* For major contributions, add a MAINTAINERS file with your 5055 information and associated file and directory references. 5056 5057* When you add support for a new board, don't forget to add a 5058 maintainer e-mail address to the boards.cfg file, too. 5059 5060* If your patch adds new configuration options, don't forget to 5061 document these in the README file. 5062 5063* The patch itself. If you are using git (which is *strongly* 5064 recommended) you can easily generate the patch using the 5065 "git format-patch". If you then use "git send-email" to send it to 5066 the U-Boot mailing list, you will avoid most of the common problems 5067 with some other mail clients. 5068 5069 If you cannot use git, use "diff -purN OLD NEW". If your version of 5070 diff does not support these options, then get the latest version of 5071 GNU diff. 5072 5073 The current directory when running this command shall be the parent 5074 directory of the U-Boot source tree (i. e. please make sure that 5075 your patch includes sufficient directory information for the 5076 affected files). 5077 5078 We prefer patches as plain text. MIME attachments are discouraged, 5079 and compressed attachments must not be used. 5080 5081* If one logical set of modifications affects or creates several 5082 files, all these changes shall be submitted in a SINGLE patch file. 5083 5084* Changesets that contain different, unrelated modifications shall be 5085 submitted as SEPARATE patches, one patch per changeset. 5086 5087 5088Notes: 5089 5090* Before sending the patch, run the buildman script on your patched 5091 source tree and make sure that no errors or warnings are reported 5092 for any of the boards. 5093 5094* Keep your modifications to the necessary minimum: A patch 5095 containing several unrelated changes or arbitrary reformats will be 5096 returned with a request to re-formatting / split it. 5097 5098* If you modify existing code, make sure that your new code does not 5099 add to the memory footprint of the code ;-) Small is beautiful! 5100 When adding new features, these should compile conditionally only 5101 (using #ifdef), and the resulting code with the new feature 5102 disabled must not need more memory than the old code without your 5103 modification. 5104 5105* Remember that there is a size limit of 100 kB per message on the 5106 u-boot mailing list. Bigger patches will be moderated. If they are 5107 reasonable and not too big, they will be acknowledged. But patches 5108 bigger than the size limit should be avoided. 5109