1# SPDX-License-Identifier: GPL-2.0+ 2# 3# (C) Copyright 2000 - 2013 4# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 5 6Summary: 7======== 8 9This directory contains the source code for U-Boot, a boot loader for 10Embedded boards based on PowerPC, ARM, MIPS and several other 11processors, which can be installed in a boot ROM and used to 12initialize and test the hardware or to download and run application 13code. 14 15The development of U-Boot is closely related to Linux: some parts of 16the source code originate in the Linux source tree, we have some 17header files in common, and special provision has been made to 18support booting of Linux images. 19 20Some attention has been paid to make this software easily 21configurable and extendable. For instance, all monitor commands are 22implemented with the same call interface, so that it's very easy to 23add new commands. Also, instead of permanently adding rarely used 24code (for instance hardware test utilities) to the monitor, you can 25load and run it dynamically. 26 27 28Status: 29======= 30 31In general, all boards for which a configuration option exists in the 32Makefile have been tested to some extent and can be considered 33"working". In fact, many of them are used in production systems. 34 35In case of problems see the CHANGELOG file to find out who contributed 36the specific port. In addition, there are various MAINTAINERS files 37scattered throughout the U-Boot source identifying the people or 38companies responsible for various boards and subsystems. 39 40Note: As of August, 2010, there is no longer a CHANGELOG file in the 41actual U-Boot source tree; however, it can be created dynamically 42from the Git log using: 43 44 make CHANGELOG 45 46 47Where to get help: 48================== 49 50In case you have questions about, problems with or contributions for 51U-Boot, you should send a message to the U-Boot mailing list at 52<u-boot@lists.denx.de>. There is also an archive of previous traffic 53on the mailing list - please search the archive before asking FAQ's. 54Please see http://lists.denx.de/pipermail/u-boot and 55http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 56 57 58Where to get source code: 59========================= 60 61The U-Boot source code is maintained in the Git repository at 62git://www.denx.de/git/u-boot.git ; you can browse it online at 63http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 64 65The "snapshot" links on this page allow you to download tarballs of 66any version you might be interested in. Official releases are also 67available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 68directory. 69 70Pre-built (and tested) images are available from 71ftp://ftp.denx.de/pub/u-boot/images/ 72 73 74Where we come from: 75=================== 76 77- start from 8xxrom sources 78- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 79- clean up code 80- make it easier to add custom boards 81- make it possible to add other [PowerPC] CPUs 82- extend functions, especially: 83 * Provide extended interface to Linux boot loader 84 * S-Record download 85 * network boot 86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 87- create ARMBoot project (http://sourceforge.net/projects/armboot) 88- add other CPU families (starting with ARM) 89- create U-Boot project (http://sourceforge.net/projects/u-boot) 90- current project page: see http://www.denx.de/wiki/U-Boot 91 92 93Names and Spelling: 94=================== 95 96The "official" name of this project is "Das U-Boot". The spelling 97"U-Boot" shall be used in all written text (documentation, comments 98in source files etc.). Example: 99 100 This is the README file for the U-Boot project. 101 102File names etc. shall be based on the string "u-boot". Examples: 103 104 include/asm-ppc/u-boot.h 105 106 #include <asm/u-boot.h> 107 108Variable names, preprocessor constants etc. shall be either based on 109the string "u_boot" or on "U_BOOT". Example: 110 111 U_BOOT_VERSION u_boot_logo 112 IH_OS_U_BOOT u_boot_hush_start 113 114 115Versioning: 116=========== 117 118Starting with the release in October 2008, the names of the releases 119were changed from numerical release numbers without deeper meaning 120into a time stamp based numbering. Regular releases are identified by 121names consisting of the calendar year and month of the release date. 122Additional fields (if present) indicate release candidates or bug fix 123releases in "stable" maintenance trees. 124 125Examples: 126 U-Boot v2009.11 - Release November 2009 127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 128 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 129 130 131Directory Hierarchy: 132==================== 133 134/arch Architecture specific files 135 /arc Files generic to ARC architecture 136 /arm Files generic to ARM architecture 137 /m68k Files generic to m68k architecture 138 /microblaze Files generic to microblaze architecture 139 /mips Files generic to MIPS architecture 140 /nds32 Files generic to NDS32 architecture 141 /nios2 Files generic to Altera NIOS2 architecture 142 /openrisc Files generic to OpenRISC architecture 143 /powerpc Files generic to PowerPC architecture 144 /riscv Files generic to RISC-V architecture 145 /sandbox Files generic to HW-independent "sandbox" 146 /sh Files generic to SH architecture 147 /x86 Files generic to x86 architecture 148/api Machine/arch independent API for external apps 149/board Board dependent files 150/cmd U-Boot commands functions 151/common Misc architecture independent functions 152/configs Board default configuration files 153/disk Code for disk drive partition handling 154/doc Documentation (don't expect too much) 155/drivers Commonly used device drivers 156/dts Contains Makefile for building internal U-Boot fdt. 157/examples Example code for standalone applications, etc. 158/fs Filesystem code (cramfs, ext2, jffs2, etc.) 159/include Header Files 160/lib Library routines generic to all architectures 161/Licenses Various license files 162/net Networking code 163/post Power On Self Test 164/scripts Various build scripts and Makefiles 165/test Various unit test files 166/tools Tools to build S-Record or U-Boot images, etc. 167 168Software Configuration: 169======================= 170 171Configuration is usually done using C preprocessor defines; the 172rationale behind that is to avoid dead code whenever possible. 173 174There are two classes of configuration variables: 175 176* Configuration _OPTIONS_: 177 These are selectable by the user and have names beginning with 178 "CONFIG_". 179 180* Configuration _SETTINGS_: 181 These depend on the hardware etc. and should not be meddled with if 182 you don't know what you're doing; they have names beginning with 183 "CONFIG_SYS_". 184 185Previously, all configuration was done by hand, which involved creating 186symbolic links and editing configuration files manually. More recently, 187U-Boot has added the Kbuild infrastructure used by the Linux kernel, 188allowing you to use the "make menuconfig" command to configure your 189build. 190 191 192Selection of Processor Architecture and Board Type: 193--------------------------------------------------- 194 195For all supported boards there are ready-to-use default 196configurations available; just type "make <board_name>_defconfig". 197 198Example: For a TQM823L module type: 199 200 cd u-boot 201 make TQM823L_defconfig 202 203Note: If you're looking for the default configuration file for a board 204you're sure used to be there but is now missing, check the file 205doc/README.scrapyard for a list of no longer supported boards. 206 207Sandbox Environment: 208-------------------- 209 210U-Boot can be built natively to run on a Linux host using the 'sandbox' 211board. This allows feature development which is not board- or architecture- 212specific to be undertaken on a native platform. The sandbox is also used to 213run some of U-Boot's tests. 214 215See board/sandbox/README.sandbox for more details. 216 217 218Board Initialisation Flow: 219-------------------------- 220 221This is the intended start-up flow for boards. This should apply for both 222SPL and U-Boot proper (i.e. they both follow the same rules). 223 224Note: "SPL" stands for "Secondary Program Loader," which is explained in 225more detail later in this file. 226 227At present, SPL mostly uses a separate code path, but the function names 228and roles of each function are the same. Some boards or architectures 229may not conform to this. At least most ARM boards which use 230CONFIG_SPL_FRAMEWORK conform to this. 231 232Execution typically starts with an architecture-specific (and possibly 233CPU-specific) start.S file, such as: 234 235 - arch/arm/cpu/armv7/start.S 236 - arch/powerpc/cpu/mpc83xx/start.S 237 - arch/mips/cpu/start.S 238 239and so on. From there, three functions are called; the purpose and 240limitations of each of these functions are described below. 241 242lowlevel_init(): 243 - purpose: essential init to permit execution to reach board_init_f() 244 - no global_data or BSS 245 - there is no stack (ARMv7 may have one but it will soon be removed) 246 - must not set up SDRAM or use console 247 - must only do the bare minimum to allow execution to continue to 248 board_init_f() 249 - this is almost never needed 250 - return normally from this function 251 252board_init_f(): 253 - purpose: set up the machine ready for running board_init_r(): 254 i.e. SDRAM and serial UART 255 - global_data is available 256 - stack is in SRAM 257 - BSS is not available, so you cannot use global/static variables, 258 only stack variables and global_data 259 260 Non-SPL-specific notes: 261 - dram_init() is called to set up DRAM. If already done in SPL this 262 can do nothing 263 264 SPL-specific notes: 265 - you can override the entire board_init_f() function with your own 266 version as needed. 267 - preloader_console_init() can be called here in extremis 268 - should set up SDRAM, and anything needed to make the UART work 269 - these is no need to clear BSS, it will be done by crt0.S 270 - must return normally from this function (don't call board_init_r() 271 directly) 272 273Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 274this point the stack and global_data are relocated to below 275CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 276memory. 277 278board_init_r(): 279 - purpose: main execution, common code 280 - global_data is available 281 - SDRAM is available 282 - BSS is available, all static/global variables can be used 283 - execution eventually continues to main_loop() 284 285 Non-SPL-specific notes: 286 - U-Boot is relocated to the top of memory and is now running from 287 there. 288 289 SPL-specific notes: 290 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 291 CONFIG_SPL_STACK_R_ADDR points into SDRAM 292 - preloader_console_init() can be called here - typically this is 293 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 294 spl_board_init() function containing this call 295 - loads U-Boot or (in falcon mode) Linux 296 297 298 299Configuration Options: 300---------------------- 301 302Configuration depends on the combination of board and CPU type; all 303such information is kept in a configuration file 304"include/configs/<board_name>.h". 305 306Example: For a TQM823L module, all configuration settings are in 307"include/configs/TQM823L.h". 308 309 310Many of the options are named exactly as the corresponding Linux 311kernel configuration options. The intention is to make it easier to 312build a config tool - later. 313 314- ARM Platform Bus Type(CCI): 315 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which 316 provides full cache coherency between two clusters of multi-core 317 CPUs and I/O coherency for devices and I/O masters 318 319 CONFIG_SYS_FSL_HAS_CCI400 320 321 Defined For SoC that has cache coherent interconnect 322 CCN-400 323 324 CONFIG_SYS_FSL_HAS_CCN504 325 326 Defined for SoC that has cache coherent interconnect CCN-504 327 328The following options need to be configured: 329 330- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 331 332- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 333 334- Marvell Family Member 335 CONFIG_SYS_MVFS - define it if you want to enable 336 multiple fs option at one time 337 for marvell soc family 338 339- 85xx CPU Options: 340 CONFIG_SYS_PPC64 341 342 Specifies that the core is a 64-bit PowerPC implementation (implements 343 the "64" category of the Power ISA). This is necessary for ePAPR 344 compliance, among other possible reasons. 345 346 CONFIG_SYS_FSL_TBCLK_DIV 347 348 Defines the core time base clock divider ratio compared to the 349 system clock. On most PQ3 devices this is 8, on newer QorIQ 350 devices it can be 16 or 32. The ratio varies from SoC to Soc. 351 352 CONFIG_SYS_FSL_PCIE_COMPAT 353 354 Defines the string to utilize when trying to match PCIe device 355 tree nodes for the given platform. 356 357 CONFIG_SYS_FSL_ERRATUM_A004510 358 359 Enables a workaround for erratum A004510. If set, 360 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 361 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 362 363 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 364 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 365 366 Defines one or two SoC revisions (low 8 bits of SVR) 367 for which the A004510 workaround should be applied. 368 369 The rest of SVR is either not relevant to the decision 370 of whether the erratum is present (e.g. p2040 versus 371 p2041) or is implied by the build target, which controls 372 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 373 374 See Freescale App Note 4493 for more information about 375 this erratum. 376 377 CONFIG_A003399_NOR_WORKAROUND 378 Enables a workaround for IFC erratum A003399. It is only 379 required during NOR boot. 380 381 CONFIG_A008044_WORKAROUND 382 Enables a workaround for T1040/T1042 erratum A008044. It is only 383 required during NAND boot and valid for Rev 1.0 SoC revision 384 385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 386 387 This is the value to write into CCSR offset 0x18600 388 according to the A004510 workaround. 389 390 CONFIG_SYS_FSL_DSP_DDR_ADDR 391 This value denotes start offset of DDR memory which is 392 connected exclusively to the DSP cores. 393 394 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 395 This value denotes start offset of M2 memory 396 which is directly connected to the DSP core. 397 398 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 399 This value denotes start offset of M3 memory which is directly 400 connected to the DSP core. 401 402 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 403 This value denotes start offset of DSP CCSR space. 404 405 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 406 Single Source Clock is clocking mode present in some of FSL SoC's. 407 In this mode, a single differential clock is used to supply 408 clocks to the sysclock, ddrclock and usbclock. 409 410 CONFIG_SYS_CPC_REINIT_F 411 This CONFIG is defined when the CPC is configured as SRAM at the 412 time of U-Boot entry and is required to be re-initialized. 413 414 CONFIG_DEEP_SLEEP 415 Indicates this SoC supports deep sleep feature. If deep sleep is 416 supported, core will start to execute uboot when wakes up. 417 418- Generic CPU options: 419 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 420 421 Defines the endianess of the CPU. Implementation of those 422 values is arch specific. 423 424 CONFIG_SYS_FSL_DDR 425 Freescale DDR driver in use. This type of DDR controller is 426 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 427 SoCs. 428 429 CONFIG_SYS_FSL_DDR_ADDR 430 Freescale DDR memory-mapped register base. 431 432 CONFIG_SYS_FSL_DDR_EMU 433 Specify emulator support for DDR. Some DDR features such as 434 deskew training are not available. 435 436 CONFIG_SYS_FSL_DDRC_GEN1 437 Freescale DDR1 controller. 438 439 CONFIG_SYS_FSL_DDRC_GEN2 440 Freescale DDR2 controller. 441 442 CONFIG_SYS_FSL_DDRC_GEN3 443 Freescale DDR3 controller. 444 445 CONFIG_SYS_FSL_DDRC_GEN4 446 Freescale DDR4 controller. 447 448 CONFIG_SYS_FSL_DDRC_ARM_GEN3 449 Freescale DDR3 controller for ARM-based SoCs. 450 451 CONFIG_SYS_FSL_DDR1 452 Board config to use DDR1. It can be enabled for SoCs with 453 Freescale DDR1 or DDR2 controllers, depending on the board 454 implemetation. 455 456 CONFIG_SYS_FSL_DDR2 457 Board config to use DDR2. It can be enabled for SoCs with 458 Freescale DDR2 or DDR3 controllers, depending on the board 459 implementation. 460 461 CONFIG_SYS_FSL_DDR3 462 Board config to use DDR3. It can be enabled for SoCs with 463 Freescale DDR3 or DDR3L controllers. 464 465 CONFIG_SYS_FSL_DDR3L 466 Board config to use DDR3L. It can be enabled for SoCs with 467 DDR3L controllers. 468 469 CONFIG_SYS_FSL_DDR4 470 Board config to use DDR4. It can be enabled for SoCs with 471 DDR4 controllers. 472 473 CONFIG_SYS_FSL_IFC_BE 474 Defines the IFC controller register space as Big Endian 475 476 CONFIG_SYS_FSL_IFC_LE 477 Defines the IFC controller register space as Little Endian 478 479 CONFIG_SYS_FSL_IFC_CLK_DIV 480 Defines divider of platform clock(clock input to IFC controller). 481 482 CONFIG_SYS_FSL_LBC_CLK_DIV 483 Defines divider of platform clock(clock input to eLBC controller). 484 485 CONFIG_SYS_FSL_PBL_PBI 486 It enables addition of RCW (Power on reset configuration) in built image. 487 Please refer doc/README.pblimage for more details 488 489 CONFIG_SYS_FSL_PBL_RCW 490 It adds PBI(pre-boot instructions) commands in u-boot build image. 491 PBI commands can be used to configure SoC before it starts the execution. 492 Please refer doc/README.pblimage for more details 493 494 CONFIG_SPL_FSL_PBL 495 It adds a target to create boot binary having SPL binary in PBI format 496 concatenated with u-boot binary. 497 498 CONFIG_SYS_FSL_DDR_BE 499 Defines the DDR controller register space as Big Endian 500 501 CONFIG_SYS_FSL_DDR_LE 502 Defines the DDR controller register space as Little Endian 503 504 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 505 Physical address from the view of DDR controllers. It is the 506 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 507 it could be different for ARM SoCs. 508 509 CONFIG_SYS_FSL_DDR_INTLV_256B 510 DDR controller interleaving on 256-byte. This is a special 511 interleaving mode, handled by Dickens for Freescale layerscape 512 SoCs with ARM core. 513 514 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 515 Number of controllers used as main memory. 516 517 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 518 Number of controllers used for other than main memory. 519 520 CONFIG_SYS_FSL_HAS_DP_DDR 521 Defines the SoC has DP-DDR used for DPAA. 522 523 CONFIG_SYS_FSL_SEC_BE 524 Defines the SEC controller register space as Big Endian 525 526 CONFIG_SYS_FSL_SEC_LE 527 Defines the SEC controller register space as Little Endian 528 529- MIPS CPU options: 530 CONFIG_SYS_INIT_SP_OFFSET 531 532 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 533 pointer. This is needed for the temporary stack before 534 relocation. 535 536 CONFIG_SYS_MIPS_CACHE_MODE 537 538 Cache operation mode for the MIPS CPU. 539 See also arch/mips/include/asm/mipsregs.h. 540 Possible values are: 541 CONF_CM_CACHABLE_NO_WA 542 CONF_CM_CACHABLE_WA 543 CONF_CM_UNCACHED 544 CONF_CM_CACHABLE_NONCOHERENT 545 CONF_CM_CACHABLE_CE 546 CONF_CM_CACHABLE_COW 547 CONF_CM_CACHABLE_CUW 548 CONF_CM_CACHABLE_ACCELERATED 549 550 CONFIG_SYS_XWAY_EBU_BOOTCFG 551 552 Special option for Lantiq XWAY SoCs for booting from NOR flash. 553 See also arch/mips/cpu/mips32/start.S. 554 555 CONFIG_XWAY_SWAP_BYTES 556 557 Enable compilation of tools/xway-swap-bytes needed for Lantiq 558 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 559 be swapped if a flash programmer is used. 560 561- ARM options: 562 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 563 564 Select high exception vectors of the ARM core, e.g., do not 565 clear the V bit of the c1 register of CP15. 566 567 COUNTER_FREQUENCY 568 Generic timer clock source frequency. 569 570 COUNTER_FREQUENCY_REAL 571 Generic timer clock source frequency if the real clock is 572 different from COUNTER_FREQUENCY, and can only be determined 573 at run time. 574 575- Tegra SoC options: 576 CONFIG_TEGRA_SUPPORT_NON_SECURE 577 578 Support executing U-Boot in non-secure (NS) mode. Certain 579 impossible actions will be skipped if the CPU is in NS mode, 580 such as ARM architectural timer initialization. 581 582- Linux Kernel Interface: 583 CONFIG_CLOCKS_IN_MHZ 584 585 U-Boot stores all clock information in Hz 586 internally. For binary compatibility with older Linux 587 kernels (which expect the clocks passed in the 588 bd_info data to be in MHz) the environment variable 589 "clocks_in_mhz" can be defined so that U-Boot 590 converts clock data to MHZ before passing it to the 591 Linux kernel. 592 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 593 "clocks_in_mhz=1" is automatically included in the 594 default environment. 595 596 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 597 598 When transferring memsize parameter to Linux, some versions 599 expect it to be in bytes, others in MB. 600 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 601 602 CONFIG_OF_LIBFDT 603 604 New kernel versions are expecting firmware settings to be 605 passed using flattened device trees (based on open firmware 606 concepts). 607 608 CONFIG_OF_LIBFDT 609 * New libfdt-based support 610 * Adds the "fdt" command 611 * The bootm command automatically updates the fdt 612 613 OF_TBCLK - The timebase frequency. 614 OF_STDOUT_PATH - The path to the console device 615 616 boards with QUICC Engines require OF_QE to set UCC MAC 617 addresses 618 619 CONFIG_OF_BOARD_SETUP 620 621 Board code has addition modification that it wants to make 622 to the flat device tree before handing it off to the kernel 623 624 CONFIG_OF_SYSTEM_SETUP 625 626 Other code has addition modification that it wants to make 627 to the flat device tree before handing it off to the kernel. 628 This causes ft_system_setup() to be called before booting 629 the kernel. 630 631 CONFIG_OF_IDE_FIXUP 632 633 U-Boot can detect if an IDE device is present or not. 634 If not, and this new config option is activated, U-Boot 635 removes the ATA node from the DTS before booting Linux, 636 so the Linux IDE driver does not probe the device and 637 crash. This is needed for buggy hardware (uc101) where 638 no pull down resistor is connected to the signal IDE5V_DD7. 639 640 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 641 642 This setting is mandatory for all boards that have only one 643 machine type and must be used to specify the machine type 644 number as it appears in the ARM machine registry 645 (see http://www.arm.linux.org.uk/developer/machines/). 646 Only boards that have multiple machine types supported 647 in a single configuration file and the machine type is 648 runtime discoverable, do not have to use this setting. 649 650- vxWorks boot parameters: 651 652 bootvx constructs a valid bootline using the following 653 environments variables: bootdev, bootfile, ipaddr, netmask, 654 serverip, gatewayip, hostname, othbootargs. 655 It loads the vxWorks image pointed bootfile. 656 657 Note: If a "bootargs" environment is defined, it will overwride 658 the defaults discussed just above. 659 660- Cache Configuration: 661 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 662 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 663 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 664 665- Cache Configuration for ARM: 666 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 667 controller 668 CONFIG_SYS_PL310_BASE - Physical base address of PL310 669 controller register space 670 671- Serial Ports: 672 CONFIG_PL010_SERIAL 673 674 Define this if you want support for Amba PrimeCell PL010 UARTs. 675 676 CONFIG_PL011_SERIAL 677 678 Define this if you want support for Amba PrimeCell PL011 UARTs. 679 680 CONFIG_PL011_CLOCK 681 682 If you have Amba PrimeCell PL011 UARTs, set this variable to 683 the clock speed of the UARTs. 684 685 CONFIG_PL01x_PORTS 686 687 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 688 define this to a list of base addresses for each (supported) 689 port. See e.g. include/configs/versatile.h 690 691 CONFIG_SERIAL_HW_FLOW_CONTROL 692 693 Define this variable to enable hw flow control in serial driver. 694 Current user of this option is drivers/serial/nsl16550.c driver 695 696- Console Baudrate: 697 CONFIG_BAUDRATE - in bps 698 Select one of the baudrates listed in 699 CONFIG_SYS_BAUDRATE_TABLE, see below. 700 701- Autoboot Command: 702 CONFIG_BOOTCOMMAND 703 Only needed when CONFIG_BOOTDELAY is enabled; 704 define a command string that is automatically executed 705 when no character is read on the console interface 706 within "Boot Delay" after reset. 707 708 CONFIG_RAMBOOT and CONFIG_NFSBOOT 709 The value of these goes into the environment as 710 "ramboot" and "nfsboot" respectively, and can be used 711 as a convenience, when switching between booting from 712 RAM and NFS. 713 714- Pre-Boot Commands: 715 CONFIG_PREBOOT 716 717 When this option is #defined, the existence of the 718 environment variable "preboot" will be checked 719 immediately before starting the CONFIG_BOOTDELAY 720 countdown and/or running the auto-boot command resp. 721 entering interactive mode. 722 723 This feature is especially useful when "preboot" is 724 automatically generated or modified. For an example 725 see the LWMON board specific code: here "preboot" is 726 modified when the user holds down a certain 727 combination of keys on the (special) keyboard when 728 booting the systems 729 730- Serial Download Echo Mode: 731 CONFIG_LOADS_ECHO 732 If defined to 1, all characters received during a 733 serial download (using the "loads" command) are 734 echoed back. This might be needed by some terminal 735 emulations (like "cu"), but may as well just take 736 time on others. This setting #define's the initial 737 value of the "loads_echo" environment variable. 738 739- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 740 CONFIG_KGDB_BAUDRATE 741 Select one of the baudrates listed in 742 CONFIG_SYS_BAUDRATE_TABLE, see below. 743 744- Removal of commands 745 If no commands are needed to boot, you can disable 746 CONFIG_CMDLINE to remove them. In this case, the command line 747 will not be available, and when U-Boot wants to execute the 748 boot command (on start-up) it will call board_run_command() 749 instead. This can reduce image size significantly for very 750 simple boot procedures. 751 752- Regular expression support: 753 CONFIG_REGEX 754 If this variable is defined, U-Boot is linked against 755 the SLRE (Super Light Regular Expression) library, 756 which adds regex support to some commands, as for 757 example "env grep" and "setexpr". 758 759- Device tree: 760 CONFIG_OF_CONTROL 761 If this variable is defined, U-Boot will use a device tree 762 to configure its devices, instead of relying on statically 763 compiled #defines in the board file. This option is 764 experimental and only available on a few boards. The device 765 tree is available in the global data as gd->fdt_blob. 766 767 U-Boot needs to get its device tree from somewhere. This can 768 be done using one of the three options below: 769 770 CONFIG_OF_EMBED 771 If this variable is defined, U-Boot will embed a device tree 772 binary in its image. This device tree file should be in the 773 board directory and called <soc>-<board>.dts. The binary file 774 is then picked up in board_init_f() and made available through 775 the global data structure as gd->fdt_blob. 776 777 CONFIG_OF_SEPARATE 778 If this variable is defined, U-Boot will build a device tree 779 binary. It will be called u-boot.dtb. Architecture-specific 780 code will locate it at run-time. Generally this works by: 781 782 cat u-boot.bin u-boot.dtb >image.bin 783 784 and in fact, U-Boot does this for you, creating a file called 785 u-boot-dtb.bin which is useful in the common case. You can 786 still use the individual files if you need something more 787 exotic. 788 789 CONFIG_OF_BOARD 790 If this variable is defined, U-Boot will use the device tree 791 provided by the board at runtime instead of embedding one with 792 the image. Only boards defining board_fdt_blob_setup() support 793 this option (see include/fdtdec.h file). 794 795- Watchdog: 796 CONFIG_WATCHDOG 797 If this variable is defined, it enables watchdog 798 support for the SoC. There must be support in the SoC 799 specific code for a watchdog. For the 8xx 800 CPUs, the SIU Watchdog feature is enabled in the SYPCR 801 register. When supported for a specific SoC is 802 available, then no further board specific code should 803 be needed to use it. 804 805 CONFIG_HW_WATCHDOG 806 When using a watchdog circuitry external to the used 807 SoC, then define this variable and provide board 808 specific code for the "hw_watchdog_reset" function. 809 810 CONFIG_AT91_HW_WDT_TIMEOUT 811 specify the timeout in seconds. default 2 seconds. 812 813- Real-Time Clock: 814 815 When CONFIG_CMD_DATE is selected, the type of the RTC 816 has to be selected, too. Define exactly one of the 817 following options: 818 819 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 820 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 821 CONFIG_RTC_MC146818 - use MC146818 RTC 822 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 823 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 824 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 825 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 826 CONFIG_RTC_DS164x - use Dallas DS164x RTC 827 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 828 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 829 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 830 CONFIG_SYS_RV3029_TCR - enable trickle charger on 831 RV3029 RTC. 832 833 Note that if the RTC uses I2C, then the I2C interface 834 must also be configured. See I2C Support, below. 835 836- GPIO Support: 837 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 838 839 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 840 chip-ngpio pairs that tell the PCA953X driver the number of 841 pins supported by a particular chip. 842 843 Note that if the GPIO device uses I2C, then the I2C interface 844 must also be configured. See I2C Support, below. 845 846- I/O tracing: 847 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 848 accesses and can checksum them or write a list of them out 849 to memory. See the 'iotrace' command for details. This is 850 useful for testing device drivers since it can confirm that 851 the driver behaves the same way before and after a code 852 change. Currently this is supported on sandbox and arm. To 853 add support for your architecture, add '#include <iotrace.h>' 854 to the bottom of arch/<arch>/include/asm/io.h and test. 855 856 Example output from the 'iotrace stats' command is below. 857 Note that if the trace buffer is exhausted, the checksum will 858 still continue to operate. 859 860 iotrace is enabled 861 Start: 10000000 (buffer start address) 862 Size: 00010000 (buffer size) 863 Offset: 00000120 (current buffer offset) 864 Output: 10000120 (start + offset) 865 Count: 00000018 (number of trace records) 866 CRC32: 9526fb66 (CRC32 of all trace records) 867 868- Timestamp Support: 869 870 When CONFIG_TIMESTAMP is selected, the timestamp 871 (date and time) of an image is printed by image 872 commands like bootm or iminfo. This option is 873 automatically enabled when you select CONFIG_CMD_DATE . 874 875- Partition Labels (disklabels) Supported: 876 Zero or more of the following: 877 CONFIG_MAC_PARTITION Apple's MacOS partition table. 878 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 879 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 880 bootloader. Note 2TB partition limit; see 881 disk/part_efi.c 882 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 883 884 If IDE or SCSI support is enabled (CONFIG_IDE or 885 CONFIG_SCSI) you must configure support for at 886 least one non-MTD partition type as well. 887 888- IDE Reset method: 889 CONFIG_IDE_RESET_ROUTINE - this is defined in several 890 board configurations files but used nowhere! 891 892 CONFIG_IDE_RESET - is this is defined, IDE Reset will 893 be performed by calling the function 894 ide_set_reset(int reset) 895 which has to be defined in a board specific file 896 897- ATAPI Support: 898 CONFIG_ATAPI 899 900 Set this to enable ATAPI support. 901 902- LBA48 Support 903 CONFIG_LBA48 904 905 Set this to enable support for disks larger than 137GB 906 Also look at CONFIG_SYS_64BIT_LBA. 907 Whithout these , LBA48 support uses 32bit variables and will 'only' 908 support disks up to 2.1TB. 909 910 CONFIG_SYS_64BIT_LBA: 911 When enabled, makes the IDE subsystem use 64bit sector addresses. 912 Default is 32bit. 913 914- SCSI Support: 915 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 916 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 917 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 918 maximum numbers of LUNs, SCSI ID's and target 919 devices. 920 921 The environment variable 'scsidevs' is set to the number of 922 SCSI devices found during the last scan. 923 924- NETWORK Support (PCI): 925 CONFIG_E1000 926 Support for Intel 8254x/8257x gigabit chips. 927 928 CONFIG_E1000_SPI 929 Utility code for direct access to the SPI bus on Intel 8257x. 930 This does not do anything useful unless you set at least one 931 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 932 933 CONFIG_E1000_SPI_GENERIC 934 Allow generic access to the SPI bus on the Intel 8257x, for 935 example with the "sspi" command. 936 937 CONFIG_EEPRO100 938 Support for Intel 82557/82559/82559ER chips. 939 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 940 write routine for first time initialisation. 941 942 CONFIG_TULIP 943 Support for Digital 2114x chips. 944 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 945 modem chip initialisation (KS8761/QS6611). 946 947 CONFIG_NATSEMI 948 Support for National dp83815 chips. 949 950 CONFIG_NS8382X 951 Support for National dp8382[01] gigabit chips. 952 953- NETWORK Support (other): 954 955 CONFIG_DRIVER_AT91EMAC 956 Support for AT91RM9200 EMAC. 957 958 CONFIG_RMII 959 Define this to use reduced MII inteface 960 961 CONFIG_DRIVER_AT91EMAC_QUIET 962 If this defined, the driver is quiet. 963 The driver doen't show link status messages. 964 965 CONFIG_CALXEDA_XGMAC 966 Support for the Calxeda XGMAC device 967 968 CONFIG_LAN91C96 969 Support for SMSC's LAN91C96 chips. 970 971 CONFIG_LAN91C96_USE_32_BIT 972 Define this to enable 32 bit addressing 973 974 CONFIG_SMC91111 975 Support for SMSC's LAN91C111 chip 976 977 CONFIG_SMC91111_BASE 978 Define this to hold the physical address 979 of the device (I/O space) 980 981 CONFIG_SMC_USE_32_BIT 982 Define this if data bus is 32 bits 983 984 CONFIG_SMC_USE_IOFUNCS 985 Define this to use i/o functions instead of macros 986 (some hardware wont work with macros) 987 988 CONFIG_DRIVER_TI_EMAC 989 Support for davinci emac 990 991 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 992 Define this if you have more then 3 PHYs. 993 994 CONFIG_FTGMAC100 995 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 996 997 CONFIG_FTGMAC100_EGIGA 998 Define this to use GE link update with gigabit PHY. 999 Define this if FTGMAC100 is connected to gigabit PHY. 1000 If your system has 10/100 PHY only, it might not occur 1001 wrong behavior. Because PHY usually return timeout or 1002 useless data when polling gigabit status and gigabit 1003 control registers. This behavior won't affect the 1004 correctnessof 10/100 link speed update. 1005 1006 CONFIG_SH_ETHER 1007 Support for Renesas on-chip Ethernet controller 1008 1009 CONFIG_SH_ETHER_USE_PORT 1010 Define the number of ports to be used 1011 1012 CONFIG_SH_ETHER_PHY_ADDR 1013 Define the ETH PHY's address 1014 1015 CONFIG_SH_ETHER_CACHE_WRITEBACK 1016 If this option is set, the driver enables cache flush. 1017 1018- PWM Support: 1019 CONFIG_PWM_IMX 1020 Support for PWM module on the imx6. 1021 1022- TPM Support: 1023 CONFIG_TPM 1024 Support TPM devices. 1025 1026 CONFIG_TPM_TIS_INFINEON 1027 Support for Infineon i2c bus TPM devices. Only one device 1028 per system is supported at this time. 1029 1030 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1031 Define the burst count bytes upper limit 1032 1033 CONFIG_TPM_ST33ZP24 1034 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1035 1036 CONFIG_TPM_ST33ZP24_I2C 1037 Support for STMicroelectronics ST33ZP24 I2C devices. 1038 Requires TPM_ST33ZP24 and I2C. 1039 1040 CONFIG_TPM_ST33ZP24_SPI 1041 Support for STMicroelectronics ST33ZP24 SPI devices. 1042 Requires TPM_ST33ZP24 and SPI. 1043 1044 CONFIG_TPM_ATMEL_TWI 1045 Support for Atmel TWI TPM device. Requires I2C support. 1046 1047 CONFIG_TPM_TIS_LPC 1048 Support for generic parallel port TPM devices. Only one device 1049 per system is supported at this time. 1050 1051 CONFIG_TPM_TIS_BASE_ADDRESS 1052 Base address where the generic TPM device is mapped 1053 to. Contemporary x86 systems usually map it at 1054 0xfed40000. 1055 1056 CONFIG_TPM 1057 Define this to enable the TPM support library which provides 1058 functional interfaces to some TPM commands. 1059 Requires support for a TPM device. 1060 1061 CONFIG_TPM_AUTH_SESSIONS 1062 Define this to enable authorized functions in the TPM library. 1063 Requires CONFIG_TPM and CONFIG_SHA1. 1064 1065- USB Support: 1066 At the moment only the UHCI host controller is 1067 supported (PIP405, MIP405); define 1068 CONFIG_USB_UHCI to enable it. 1069 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1070 and define CONFIG_USB_STORAGE to enable the USB 1071 storage devices. 1072 Note: 1073 Supported are USB Keyboards and USB Floppy drives 1074 (TEAC FD-05PUB). 1075 1076 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1077 txfilltuning field in the EHCI controller on reset. 1078 1079 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1080 HW module registers. 1081 1082- USB Device: 1083 Define the below if you wish to use the USB console. 1084 Once firmware is rebuilt from a serial console issue the 1085 command "setenv stdin usbtty; setenv stdout usbtty" and 1086 attach your USB cable. The Unix command "dmesg" should print 1087 it has found a new device. The environment variable usbtty 1088 can be set to gserial or cdc_acm to enable your device to 1089 appear to a USB host as a Linux gserial device or a 1090 Common Device Class Abstract Control Model serial device. 1091 If you select usbtty = gserial you should be able to enumerate 1092 a Linux host by 1093 # modprobe usbserial vendor=0xVendorID product=0xProductID 1094 else if using cdc_acm, simply setting the environment 1095 variable usbtty to be cdc_acm should suffice. The following 1096 might be defined in YourBoardName.h 1097 1098 CONFIG_USB_DEVICE 1099 Define this to build a UDC device 1100 1101 CONFIG_USB_TTY 1102 Define this to have a tty type of device available to 1103 talk to the UDC device 1104 1105 CONFIG_USBD_HS 1106 Define this to enable the high speed support for usb 1107 device and usbtty. If this feature is enabled, a routine 1108 int is_usbd_high_speed(void) 1109 also needs to be defined by the driver to dynamically poll 1110 whether the enumeration has succeded at high speed or full 1111 speed. 1112 1113 CONFIG_SYS_CONSOLE_IS_IN_ENV 1114 Define this if you want stdin, stdout &/or stderr to 1115 be set to usbtty. 1116 1117 If you have a USB-IF assigned VendorID then you may wish to 1118 define your own vendor specific values either in BoardName.h 1119 or directly in usbd_vendor_info.h. If you don't define 1120 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1121 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1122 should pretend to be a Linux device to it's target host. 1123 1124 CONFIG_USBD_MANUFACTURER 1125 Define this string as the name of your company for 1126 - CONFIG_USBD_MANUFACTURER "my company" 1127 1128 CONFIG_USBD_PRODUCT_NAME 1129 Define this string as the name of your product 1130 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1131 1132 CONFIG_USBD_VENDORID 1133 Define this as your assigned Vendor ID from the USB 1134 Implementors Forum. This *must* be a genuine Vendor ID 1135 to avoid polluting the USB namespace. 1136 - CONFIG_USBD_VENDORID 0xFFFF 1137 1138 CONFIG_USBD_PRODUCTID 1139 Define this as the unique Product ID 1140 for your device 1141 - CONFIG_USBD_PRODUCTID 0xFFFF 1142 1143- ULPI Layer Support: 1144 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1145 the generic ULPI layer. The generic layer accesses the ULPI PHY 1146 via the platform viewport, so you need both the genric layer and 1147 the viewport enabled. Currently only Chipidea/ARC based 1148 viewport is supported. 1149 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1150 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1151 If your ULPI phy needs a different reference clock than the 1152 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1153 the appropriate value in Hz. 1154 1155- MMC Support: 1156 The MMC controller on the Intel PXA is supported. To 1157 enable this define CONFIG_MMC. The MMC can be 1158 accessed from the boot prompt by mapping the device 1159 to physical memory similar to flash. Command line is 1160 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1161 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1162 1163 CONFIG_SH_MMCIF 1164 Support for Renesas on-chip MMCIF controller 1165 1166 CONFIG_SH_MMCIF_ADDR 1167 Define the base address of MMCIF registers 1168 1169 CONFIG_SH_MMCIF_CLK 1170 Define the clock frequency for MMCIF 1171 1172 CONFIG_SUPPORT_EMMC_BOOT 1173 Enable some additional features of the eMMC boot partitions. 1174 1175 CONFIG_SUPPORT_EMMC_RPMB 1176 Enable the commands for reading, writing and programming the 1177 key for the Replay Protection Memory Block partition in eMMC. 1178 1179- USB Device Firmware Update (DFU) class support: 1180 CONFIG_DFU_OVER_USB 1181 This enables the USB portion of the DFU USB class 1182 1183 CONFIG_DFU_MMC 1184 This enables support for exposing (e)MMC devices via DFU. 1185 1186 CONFIG_DFU_NAND 1187 This enables support for exposing NAND devices via DFU. 1188 1189 CONFIG_DFU_RAM 1190 This enables support for exposing RAM via DFU. 1191 Note: DFU spec refer to non-volatile memory usage, but 1192 allow usages beyond the scope of spec - here RAM usage, 1193 one that would help mostly the developer. 1194 1195 CONFIG_SYS_DFU_DATA_BUF_SIZE 1196 Dfu transfer uses a buffer before writing data to the 1197 raw storage device. Make the size (in bytes) of this buffer 1198 configurable. The size of this buffer is also configurable 1199 through the "dfu_bufsiz" environment variable. 1200 1201 CONFIG_SYS_DFU_MAX_FILE_SIZE 1202 When updating files rather than the raw storage device, 1203 we use a static buffer to copy the file into and then write 1204 the buffer once we've been given the whole file. Define 1205 this to the maximum filesize (in bytes) for the buffer. 1206 Default is 4 MiB if undefined. 1207 1208 DFU_DEFAULT_POLL_TIMEOUT 1209 Poll timeout [ms], is the timeout a device can send to the 1210 host. The host must wait for this timeout before sending 1211 a subsequent DFU_GET_STATUS request to the device. 1212 1213 DFU_MANIFEST_POLL_TIMEOUT 1214 Poll timeout [ms], which the device sends to the host when 1215 entering dfuMANIFEST state. Host waits this timeout, before 1216 sending again an USB request to the device. 1217 1218- Journaling Flash filesystem support: 1219 CONFIG_JFFS2_NAND 1220 Define these for a default partition on a NAND device 1221 1222 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1223 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1224 Define these for a default partition on a NOR device 1225 1226- Keyboard Support: 1227 See Kconfig help for available keyboard drivers. 1228 1229 CONFIG_KEYBOARD 1230 1231 Define this to enable a custom keyboard support. 1232 This simply calls drv_keyboard_init() which must be 1233 defined in your board-specific files. This option is deprecated 1234 and is only used by novena. For new boards, use driver model 1235 instead. 1236 1237- Video support: 1238 CONFIG_FSL_DIU_FB 1239 Enable the Freescale DIU video driver. Reference boards for 1240 SOCs that have a DIU should define this macro to enable DIU 1241 support, and should also define these other macros: 1242 1243 CONFIG_SYS_DIU_ADDR 1244 CONFIG_VIDEO 1245 CONFIG_CFB_CONSOLE 1246 CONFIG_VIDEO_SW_CURSOR 1247 CONFIG_VGA_AS_SINGLE_DEVICE 1248 CONFIG_VIDEO_LOGO 1249 CONFIG_VIDEO_BMP_LOGO 1250 1251 The DIU driver will look for the 'video-mode' environment 1252 variable, and if defined, enable the DIU as a console during 1253 boot. See the documentation file doc/README.video for a 1254 description of this variable. 1255 1256- LCD Support: CONFIG_LCD 1257 1258 Define this to enable LCD support (for output to LCD 1259 display); also select one of the supported displays 1260 by defining one of these: 1261 1262 CONFIG_ATMEL_LCD: 1263 1264 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1265 1266 CONFIG_NEC_NL6448AC33: 1267 1268 NEC NL6448AC33-18. Active, color, single scan. 1269 1270 CONFIG_NEC_NL6448BC20 1271 1272 NEC NL6448BC20-08. 6.5", 640x480. 1273 Active, color, single scan. 1274 1275 CONFIG_NEC_NL6448BC33_54 1276 1277 NEC NL6448BC33-54. 10.4", 640x480. 1278 Active, color, single scan. 1279 1280 CONFIG_SHARP_16x9 1281 1282 Sharp 320x240. Active, color, single scan. 1283 It isn't 16x9, and I am not sure what it is. 1284 1285 CONFIG_SHARP_LQ64D341 1286 1287 Sharp LQ64D341 display, 640x480. 1288 Active, color, single scan. 1289 1290 CONFIG_HLD1045 1291 1292 HLD1045 display, 640x480. 1293 Active, color, single scan. 1294 1295 CONFIG_OPTREX_BW 1296 1297 Optrex CBL50840-2 NF-FW 99 22 M5 1298 or 1299 Hitachi LMG6912RPFC-00T 1300 or 1301 Hitachi SP14Q002 1302 1303 320x240. Black & white. 1304 1305 CONFIG_LCD_ALIGNMENT 1306 1307 Normally the LCD is page-aligned (typically 4KB). If this is 1308 defined then the LCD will be aligned to this value instead. 1309 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1310 here, since it is cheaper to change data cache settings on 1311 a per-section basis. 1312 1313 1314 CONFIG_LCD_ROTATION 1315 1316 Sometimes, for example if the display is mounted in portrait 1317 mode or even if it's mounted landscape but rotated by 180degree, 1318 we need to rotate our content of the display relative to the 1319 framebuffer, so that user can read the messages which are 1320 printed out. 1321 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1322 initialized with a given rotation from "vl_rot" out of 1323 "vidinfo_t" which is provided by the board specific code. 1324 The value for vl_rot is coded as following (matching to 1325 fbcon=rotate:<n> linux-kernel commandline): 1326 0 = no rotation respectively 0 degree 1327 1 = 90 degree rotation 1328 2 = 180 degree rotation 1329 3 = 270 degree rotation 1330 1331 If CONFIG_LCD_ROTATION is not defined, the console will be 1332 initialized with 0degree rotation. 1333 1334 CONFIG_LCD_BMP_RLE8 1335 1336 Support drawing of RLE8-compressed bitmaps on the LCD. 1337 1338 CONFIG_I2C_EDID 1339 1340 Enables an 'i2c edid' command which can read EDID 1341 information over I2C from an attached LCD display. 1342 1343- Splash Screen Support: CONFIG_SPLASH_SCREEN 1344 1345 If this option is set, the environment is checked for 1346 a variable "splashimage". If found, the usual display 1347 of logo, copyright and system information on the LCD 1348 is suppressed and the BMP image at the address 1349 specified in "splashimage" is loaded instead. The 1350 console is redirected to the "nulldev", too. This 1351 allows for a "silent" boot where a splash screen is 1352 loaded very quickly after power-on. 1353 1354 CONFIG_SPLASHIMAGE_GUARD 1355 1356 If this option is set, then U-Boot will prevent the environment 1357 variable "splashimage" from being set to a problematic address 1358 (see doc/README.displaying-bmps). 1359 This option is useful for targets where, due to alignment 1360 restrictions, an improperly aligned BMP image will cause a data 1361 abort. If you think you will not have problems with unaligned 1362 accesses (for example because your toolchain prevents them) 1363 there is no need to set this option. 1364 1365 CONFIG_SPLASH_SCREEN_ALIGN 1366 1367 If this option is set the splash image can be freely positioned 1368 on the screen. Environment variable "splashpos" specifies the 1369 position as "x,y". If a positive number is given it is used as 1370 number of pixel from left/top. If a negative number is given it 1371 is used as number of pixel from right/bottom. You can also 1372 specify 'm' for centering the image. 1373 1374 Example: 1375 setenv splashpos m,m 1376 => image at center of screen 1377 1378 setenv splashpos 30,20 1379 => image at x = 30 and y = 20 1380 1381 setenv splashpos -10,m 1382 => vertically centered image 1383 at x = dspWidth - bmpWidth - 9 1384 1385- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1386 1387 If this option is set, additionally to standard BMP 1388 images, gzipped BMP images can be displayed via the 1389 splashscreen support or the bmp command. 1390 1391- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1392 1393 If this option is set, 8-bit RLE compressed BMP images 1394 can be displayed via the splashscreen support or the 1395 bmp command. 1396 1397- Compression support: 1398 CONFIG_GZIP 1399 1400 Enabled by default to support gzip compressed images. 1401 1402 CONFIG_BZIP2 1403 1404 If this option is set, support for bzip2 compressed 1405 images is included. If not, only uncompressed and gzip 1406 compressed images are supported. 1407 1408 NOTE: the bzip2 algorithm requires a lot of RAM, so 1409 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1410 be at least 4MB. 1411 1412- MII/PHY support: 1413 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1414 1415 The clock frequency of the MII bus 1416 1417 CONFIG_PHY_RESET_DELAY 1418 1419 Some PHY like Intel LXT971A need extra delay after 1420 reset before any MII register access is possible. 1421 For such PHY, set this option to the usec delay 1422 required. (minimum 300usec for LXT971A) 1423 1424 CONFIG_PHY_CMD_DELAY (ppc4xx) 1425 1426 Some PHY like Intel LXT971A need extra delay after 1427 command issued before MII status register can be read 1428 1429- IP address: 1430 CONFIG_IPADDR 1431 1432 Define a default value for the IP address to use for 1433 the default Ethernet interface, in case this is not 1434 determined through e.g. bootp. 1435 (Environment variable "ipaddr") 1436 1437- Server IP address: 1438 CONFIG_SERVERIP 1439 1440 Defines a default value for the IP address of a TFTP 1441 server to contact when using the "tftboot" command. 1442 (Environment variable "serverip") 1443 1444 CONFIG_KEEP_SERVERADDR 1445 1446 Keeps the server's MAC address, in the env 'serveraddr' 1447 for passing to bootargs (like Linux's netconsole option) 1448 1449- Gateway IP address: 1450 CONFIG_GATEWAYIP 1451 1452 Defines a default value for the IP address of the 1453 default router where packets to other networks are 1454 sent to. 1455 (Environment variable "gatewayip") 1456 1457- Subnet mask: 1458 CONFIG_NETMASK 1459 1460 Defines a default value for the subnet mask (or 1461 routing prefix) which is used to determine if an IP 1462 address belongs to the local subnet or needs to be 1463 forwarded through a router. 1464 (Environment variable "netmask") 1465 1466- Multicast TFTP Mode: 1467 CONFIG_MCAST_TFTP 1468 1469 Defines whether you want to support multicast TFTP as per 1470 rfc-2090; for example to work with atftp. Lets lots of targets 1471 tftp down the same boot image concurrently. Note: the Ethernet 1472 driver in use must provide a function: mcast() to join/leave a 1473 multicast group. 1474 1475- BOOTP Recovery Mode: 1476 CONFIG_BOOTP_RANDOM_DELAY 1477 1478 If you have many targets in a network that try to 1479 boot using BOOTP, you may want to avoid that all 1480 systems send out BOOTP requests at precisely the same 1481 moment (which would happen for instance at recovery 1482 from a power failure, when all systems will try to 1483 boot, thus flooding the BOOTP server. Defining 1484 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1485 inserted before sending out BOOTP requests. The 1486 following delays are inserted then: 1487 1488 1st BOOTP request: delay 0 ... 1 sec 1489 2nd BOOTP request: delay 0 ... 2 sec 1490 3rd BOOTP request: delay 0 ... 4 sec 1491 4th and following 1492 BOOTP requests: delay 0 ... 8 sec 1493 1494 CONFIG_BOOTP_ID_CACHE_SIZE 1495 1496 BOOTP packets are uniquely identified using a 32-bit ID. The 1497 server will copy the ID from client requests to responses and 1498 U-Boot will use this to determine if it is the destination of 1499 an incoming response. Some servers will check that addresses 1500 aren't in use before handing them out (usually using an ARP 1501 ping) and therefore take up to a few hundred milliseconds to 1502 respond. Network congestion may also influence the time it 1503 takes for a response to make it back to the client. If that 1504 time is too long, U-Boot will retransmit requests. In order 1505 to allow earlier responses to still be accepted after these 1506 retransmissions, U-Boot's BOOTP client keeps a small cache of 1507 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1508 cache. The default is to keep IDs for up to four outstanding 1509 requests. Increasing this will allow U-Boot to accept offers 1510 from a BOOTP client in networks with unusually high latency. 1511 1512- DHCP Advanced Options: 1513 You can fine tune the DHCP functionality by defining 1514 CONFIG_BOOTP_* symbols: 1515 1516 CONFIG_BOOTP_NISDOMAIN 1517 CONFIG_BOOTP_BOOTFILESIZE 1518 CONFIG_BOOTP_SEND_HOSTNAME 1519 CONFIG_BOOTP_NTPSERVER 1520 CONFIG_BOOTP_TIMEOFFSET 1521 CONFIG_BOOTP_VENDOREX 1522 CONFIG_BOOTP_MAY_FAIL 1523 1524 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1525 environment variable, not the BOOTP server. 1526 1527 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1528 after the configured retry count, the call will fail 1529 instead of starting over. This can be used to fail over 1530 to Link-local IP address configuration if the DHCP server 1531 is not available. 1532 1533 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1534 to do a dynamic update of a DNS server. To do this, they 1535 need the hostname of the DHCP requester. 1536 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1537 of the "hostname" environment variable is passed as 1538 option 12 to the DHCP server. 1539 1540 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1541 1542 A 32bit value in microseconds for a delay between 1543 receiving a "DHCP Offer" and sending the "DHCP Request". 1544 This fixes a problem with certain DHCP servers that don't 1545 respond 100% of the time to a "DHCP request". E.g. On an 1546 AT91RM9200 processor running at 180MHz, this delay needed 1547 to be *at least* 15,000 usec before a Windows Server 2003 1548 DHCP server would reply 100% of the time. I recommend at 1549 least 50,000 usec to be safe. The alternative is to hope 1550 that one of the retries will be successful but note that 1551 the DHCP timeout and retry process takes a longer than 1552 this delay. 1553 1554 - Link-local IP address negotiation: 1555 Negotiate with other link-local clients on the local network 1556 for an address that doesn't require explicit configuration. 1557 This is especially useful if a DHCP server cannot be guaranteed 1558 to exist in all environments that the device must operate. 1559 1560 See doc/README.link-local for more information. 1561 1562 - MAC address from environment variables 1563 1564 FDT_SEQ_MACADDR_FROM_ENV 1565 1566 Fix-up device tree with MAC addresses fetched sequentially from 1567 environment variables. This config work on assumption that 1568 non-usable ethernet node of device-tree are either not present 1569 or their status has been marked as "disabled". 1570 1571 - CDP Options: 1572 CONFIG_CDP_DEVICE_ID 1573 1574 The device id used in CDP trigger frames. 1575 1576 CONFIG_CDP_DEVICE_ID_PREFIX 1577 1578 A two character string which is prefixed to the MAC address 1579 of the device. 1580 1581 CONFIG_CDP_PORT_ID 1582 1583 A printf format string which contains the ascii name of 1584 the port. Normally is set to "eth%d" which sets 1585 eth0 for the first Ethernet, eth1 for the second etc. 1586 1587 CONFIG_CDP_CAPABILITIES 1588 1589 A 32bit integer which indicates the device capabilities; 1590 0x00000010 for a normal host which does not forwards. 1591 1592 CONFIG_CDP_VERSION 1593 1594 An ascii string containing the version of the software. 1595 1596 CONFIG_CDP_PLATFORM 1597 1598 An ascii string containing the name of the platform. 1599 1600 CONFIG_CDP_TRIGGER 1601 1602 A 32bit integer sent on the trigger. 1603 1604 CONFIG_CDP_POWER_CONSUMPTION 1605 1606 A 16bit integer containing the power consumption of the 1607 device in .1 of milliwatts. 1608 1609 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1610 1611 A byte containing the id of the VLAN. 1612 1613- Status LED: CONFIG_LED_STATUS 1614 1615 Several configurations allow to display the current 1616 status using a LED. For instance, the LED will blink 1617 fast while running U-Boot code, stop blinking as 1618 soon as a reply to a BOOTP request was received, and 1619 start blinking slow once the Linux kernel is running 1620 (supported by a status LED driver in the Linux 1621 kernel). Defining CONFIG_LED_STATUS enables this 1622 feature in U-Boot. 1623 1624 Additional options: 1625 1626 CONFIG_LED_STATUS_GPIO 1627 The status LED can be connected to a GPIO pin. 1628 In such cases, the gpio_led driver can be used as a 1629 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1630 to include the gpio_led driver in the U-Boot binary. 1631 1632 CONFIG_GPIO_LED_INVERTED_TABLE 1633 Some GPIO connected LEDs may have inverted polarity in which 1634 case the GPIO high value corresponds to LED off state and 1635 GPIO low value corresponds to LED on state. 1636 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1637 with a list of GPIO LEDs that have inverted polarity. 1638 1639- I2C Support: CONFIG_SYS_I2C 1640 1641 This enable the NEW i2c subsystem, and will allow you to use 1642 i2c commands at the u-boot command line (as long as you set 1643 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1644 based realtime clock chips or other i2c devices. See 1645 common/cmd_i2c.c for a description of the command line 1646 interface. 1647 1648 ported i2c driver to the new framework: 1649 - drivers/i2c/soft_i2c.c: 1650 - activate first bus with CONFIG_SYS_I2C_SOFT define 1651 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1652 for defining speed and slave address 1653 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1654 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1655 for defining speed and slave address 1656 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1657 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1658 for defining speed and slave address 1659 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1660 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1661 for defining speed and slave address 1662 1663 - drivers/i2c/fsl_i2c.c: 1664 - activate i2c driver with CONFIG_SYS_I2C_FSL 1665 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1666 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1667 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1668 bus. 1669 - If your board supports a second fsl i2c bus, define 1670 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1671 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1672 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1673 second bus. 1674 1675 - drivers/i2c/tegra_i2c.c: 1676 - activate this driver with CONFIG_SYS_I2C_TEGRA 1677 - This driver adds 4 i2c buses with a fix speed from 1678 100000 and the slave addr 0! 1679 1680 - drivers/i2c/ppc4xx_i2c.c 1681 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1682 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1683 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1684 1685 - drivers/i2c/i2c_mxc.c 1686 - activate this driver with CONFIG_SYS_I2C_MXC 1687 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1688 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1689 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1690 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1691 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1692 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1693 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1694 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1695 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1696 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1697 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1698 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1699 If those defines are not set, default value is 100000 1700 for speed, and 0 for slave. 1701 1702 - drivers/i2c/rcar_i2c.c: 1703 - activate this driver with CONFIG_SYS_I2C_RCAR 1704 - This driver adds 4 i2c buses 1705 1706 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1707 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1708 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1709 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1710 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1711 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1712 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1713 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1714 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1715 1716 - drivers/i2c/sh_i2c.c: 1717 - activate this driver with CONFIG_SYS_I2C_SH 1718 - This driver adds from 2 to 5 i2c buses 1719 1720 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1721 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1722 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1723 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1724 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1725 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1726 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1727 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1728 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1729 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1730 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1731 1732 - drivers/i2c/omap24xx_i2c.c 1733 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1734 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1735 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1736 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1737 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1738 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1739 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1740 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1741 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1742 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1743 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1744 1745 - drivers/i2c/zynq_i2c.c 1746 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1747 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1748 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1749 1750 - drivers/i2c/s3c24x0_i2c.c: 1751 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1752 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1753 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1754 with a fix speed from 100000 and the slave addr 0! 1755 1756 - drivers/i2c/ihs_i2c.c 1757 - activate this driver with CONFIG_SYS_I2C_IHS 1758 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1759 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1760 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1761 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1762 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1763 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1764 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1765 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1766 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1767 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1768 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1769 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1770 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1771 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1772 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1773 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1774 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1775 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1776 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1777 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1778 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1779 1780 additional defines: 1781 1782 CONFIG_SYS_NUM_I2C_BUSES 1783 Hold the number of i2c buses you want to use. 1784 1785 CONFIG_SYS_I2C_DIRECT_BUS 1786 define this, if you don't use i2c muxes on your hardware. 1787 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1788 omit this define. 1789 1790 CONFIG_SYS_I2C_MAX_HOPS 1791 define how many muxes are maximal consecutively connected 1792 on one i2c bus. If you not use i2c muxes, omit this 1793 define. 1794 1795 CONFIG_SYS_I2C_BUSES 1796 hold a list of buses you want to use, only used if 1797 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1798 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1799 CONFIG_SYS_NUM_I2C_BUSES = 9: 1800 1801 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1802 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1803 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1804 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1805 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1806 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1807 {1, {I2C_NULL_HOP}}, \ 1808 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1809 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1810 } 1811 1812 which defines 1813 bus 0 on adapter 0 without a mux 1814 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1815 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1816 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1817 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1818 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1819 bus 6 on adapter 1 without a mux 1820 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1821 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1822 1823 If you do not have i2c muxes on your board, omit this define. 1824 1825- Legacy I2C Support: 1826 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1827 then the following macros need to be defined (examples are 1828 from include/configs/lwmon.h): 1829 1830 I2C_INIT 1831 1832 (Optional). Any commands necessary to enable the I2C 1833 controller or configure ports. 1834 1835 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1836 1837 I2C_ACTIVE 1838 1839 The code necessary to make the I2C data line active 1840 (driven). If the data line is open collector, this 1841 define can be null. 1842 1843 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1844 1845 I2C_TRISTATE 1846 1847 The code necessary to make the I2C data line tri-stated 1848 (inactive). If the data line is open collector, this 1849 define can be null. 1850 1851 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1852 1853 I2C_READ 1854 1855 Code that returns true if the I2C data line is high, 1856 false if it is low. 1857 1858 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1859 1860 I2C_SDA(bit) 1861 1862 If <bit> is true, sets the I2C data line high. If it 1863 is false, it clears it (low). 1864 1865 eg: #define I2C_SDA(bit) \ 1866 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1867 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1868 1869 I2C_SCL(bit) 1870 1871 If <bit> is true, sets the I2C clock line high. If it 1872 is false, it clears it (low). 1873 1874 eg: #define I2C_SCL(bit) \ 1875 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1876 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1877 1878 I2C_DELAY 1879 1880 This delay is invoked four times per clock cycle so this 1881 controls the rate of data transfer. The data rate thus 1882 is 1 / (I2C_DELAY * 4). Often defined to be something 1883 like: 1884 1885 #define I2C_DELAY udelay(2) 1886 1887 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1888 1889 If your arch supports the generic GPIO framework (asm/gpio.h), 1890 then you may alternatively define the two GPIOs that are to be 1891 used as SCL / SDA. Any of the previous I2C_xxx macros will 1892 have GPIO-based defaults assigned to them as appropriate. 1893 1894 You should define these to the GPIO value as given directly to 1895 the generic GPIO functions. 1896 1897 CONFIG_SYS_I2C_INIT_BOARD 1898 1899 When a board is reset during an i2c bus transfer 1900 chips might think that the current transfer is still 1901 in progress. On some boards it is possible to access 1902 the i2c SCLK line directly, either by using the 1903 processor pin as a GPIO or by having a second pin 1904 connected to the bus. If this option is defined a 1905 custom i2c_init_board() routine in boards/xxx/board.c 1906 is run early in the boot sequence. 1907 1908 CONFIG_I2C_MULTI_BUS 1909 1910 This option allows the use of multiple I2C buses, each of which 1911 must have a controller. At any point in time, only one bus is 1912 active. To switch to a different bus, use the 'i2c dev' command. 1913 Note that bus numbering is zero-based. 1914 1915 CONFIG_SYS_I2C_NOPROBES 1916 1917 This option specifies a list of I2C devices that will be skipped 1918 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1919 is set, specify a list of bus-device pairs. Otherwise, specify 1920 a 1D array of device addresses 1921 1922 e.g. 1923 #undef CONFIG_I2C_MULTI_BUS 1924 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1925 1926 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1927 1928 #define CONFIG_I2C_MULTI_BUS 1929 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1930 1931 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1932 1933 CONFIG_SYS_SPD_BUS_NUM 1934 1935 If defined, then this indicates the I2C bus number for DDR SPD. 1936 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1937 1938 CONFIG_SYS_RTC_BUS_NUM 1939 1940 If defined, then this indicates the I2C bus number for the RTC. 1941 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1942 1943 CONFIG_SOFT_I2C_READ_REPEATED_START 1944 1945 defining this will force the i2c_read() function in 1946 the soft_i2c driver to perform an I2C repeated start 1947 between writing the address pointer and reading the 1948 data. If this define is omitted the default behaviour 1949 of doing a stop-start sequence will be used. Most I2C 1950 devices can use either method, but some require one or 1951 the other. 1952 1953- SPI Support: CONFIG_SPI 1954 1955 Enables SPI driver (so far only tested with 1956 SPI EEPROM, also an instance works with Crystal A/D and 1957 D/As on the SACSng board) 1958 1959 CONFIG_SOFT_SPI 1960 1961 Enables a software (bit-bang) SPI driver rather than 1962 using hardware support. This is a general purpose 1963 driver that only requires three general I/O port pins 1964 (two outputs, one input) to function. If this is 1965 defined, the board configuration must define several 1966 SPI configuration items (port pins to use, etc). For 1967 an example, see include/configs/sacsng.h. 1968 1969 CONFIG_HARD_SPI 1970 1971 Enables a hardware SPI driver for general-purpose reads 1972 and writes. As with CONFIG_SOFT_SPI, the board configuration 1973 must define a list of chip-select function pointers. 1974 Currently supported on some MPC8xxx processors. For an 1975 example, see include/configs/mpc8349emds.h. 1976 1977 CONFIG_SYS_SPI_MXC_WAIT 1978 Timeout for waiting until spi transfer completed. 1979 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1980 1981- FPGA Support: CONFIG_FPGA 1982 1983 Enables FPGA subsystem. 1984 1985 CONFIG_FPGA_<vendor> 1986 1987 Enables support for specific chip vendors. 1988 (ALTERA, XILINX) 1989 1990 CONFIG_FPGA_<family> 1991 1992 Enables support for FPGA family. 1993 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1994 1995 CONFIG_FPGA_COUNT 1996 1997 Specify the number of FPGA devices to support. 1998 1999 CONFIG_SYS_FPGA_PROG_FEEDBACK 2000 2001 Enable printing of hash marks during FPGA configuration. 2002 2003 CONFIG_SYS_FPGA_CHECK_BUSY 2004 2005 Enable checks on FPGA configuration interface busy 2006 status by the configuration function. This option 2007 will require a board or device specific function to 2008 be written. 2009 2010 CONFIG_FPGA_DELAY 2011 2012 If defined, a function that provides delays in the FPGA 2013 configuration driver. 2014 2015 CONFIG_SYS_FPGA_CHECK_CTRLC 2016 Allow Control-C to interrupt FPGA configuration 2017 2018 CONFIG_SYS_FPGA_CHECK_ERROR 2019 2020 Check for configuration errors during FPGA bitfile 2021 loading. For example, abort during Virtex II 2022 configuration if the INIT_B line goes low (which 2023 indicated a CRC error). 2024 2025 CONFIG_SYS_FPGA_WAIT_INIT 2026 2027 Maximum time to wait for the INIT_B line to de-assert 2028 after PROB_B has been de-asserted during a Virtex II 2029 FPGA configuration sequence. The default time is 500 2030 ms. 2031 2032 CONFIG_SYS_FPGA_WAIT_BUSY 2033 2034 Maximum time to wait for BUSY to de-assert during 2035 Virtex II FPGA configuration. The default is 5 ms. 2036 2037 CONFIG_SYS_FPGA_WAIT_CONFIG 2038 2039 Time to wait after FPGA configuration. The default is 2040 200 ms. 2041 2042- Configuration Management: 2043 CONFIG_BUILD_TARGET 2044 2045 Some SoCs need special image types (e.g. U-Boot binary 2046 with a special header) as build targets. By defining 2047 CONFIG_BUILD_TARGET in the SoC / board header, this 2048 special image will be automatically built upon calling 2049 make / buildman. 2050 2051 CONFIG_IDENT_STRING 2052 2053 If defined, this string will be added to the U-Boot 2054 version information (U_BOOT_VERSION) 2055 2056- Vendor Parameter Protection: 2057 2058 U-Boot considers the values of the environment 2059 variables "serial#" (Board Serial Number) and 2060 "ethaddr" (Ethernet Address) to be parameters that 2061 are set once by the board vendor / manufacturer, and 2062 protects these variables from casual modification by 2063 the user. Once set, these variables are read-only, 2064 and write or delete attempts are rejected. You can 2065 change this behaviour: 2066 2067 If CONFIG_ENV_OVERWRITE is #defined in your config 2068 file, the write protection for vendor parameters is 2069 completely disabled. Anybody can change or delete 2070 these parameters. 2071 2072 Alternatively, if you define _both_ an ethaddr in the 2073 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2074 Ethernet address is installed in the environment, 2075 which can be changed exactly ONCE by the user. [The 2076 serial# is unaffected by this, i. e. it remains 2077 read-only.] 2078 2079 The same can be accomplished in a more flexible way 2080 for any variable by configuring the type of access 2081 to allow for those variables in the ".flags" variable 2082 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2083 2084- Protected RAM: 2085 CONFIG_PRAM 2086 2087 Define this variable to enable the reservation of 2088 "protected RAM", i. e. RAM which is not overwritten 2089 by U-Boot. Define CONFIG_PRAM to hold the number of 2090 kB you want to reserve for pRAM. You can overwrite 2091 this default value by defining an environment 2092 variable "pram" to the number of kB you want to 2093 reserve. Note that the board info structure will 2094 still show the full amount of RAM. If pRAM is 2095 reserved, a new environment variable "mem" will 2096 automatically be defined to hold the amount of 2097 remaining RAM in a form that can be passed as boot 2098 argument to Linux, for instance like that: 2099 2100 setenv bootargs ... mem=\${mem} 2101 saveenv 2102 2103 This way you can tell Linux not to use this memory, 2104 either, which results in a memory region that will 2105 not be affected by reboots. 2106 2107 *WARNING* If your board configuration uses automatic 2108 detection of the RAM size, you must make sure that 2109 this memory test is non-destructive. So far, the 2110 following board configurations are known to be 2111 "pRAM-clean": 2112 2113 IVMS8, IVML24, SPD8xx, 2114 HERMES, IP860, RPXlite, LWMON, 2115 FLAGADM 2116 2117- Access to physical memory region (> 4GB) 2118 Some basic support is provided for operations on memory not 2119 normally accessible to U-Boot - e.g. some architectures 2120 support access to more than 4GB of memory on 32-bit 2121 machines using physical address extension or similar. 2122 Define CONFIG_PHYSMEM to access this basic support, which 2123 currently only supports clearing the memory. 2124 2125- Error Recovery: 2126 CONFIG_NET_RETRY_COUNT 2127 2128 This variable defines the number of retries for 2129 network operations like ARP, RARP, TFTP, or BOOTP 2130 before giving up the operation. If not defined, a 2131 default value of 5 is used. 2132 2133 CONFIG_ARP_TIMEOUT 2134 2135 Timeout waiting for an ARP reply in milliseconds. 2136 2137 CONFIG_NFS_TIMEOUT 2138 2139 Timeout in milliseconds used in NFS protocol. 2140 If you encounter "ERROR: Cannot umount" in nfs command, 2141 try longer timeout such as 2142 #define CONFIG_NFS_TIMEOUT 10000UL 2143 2144- Command Interpreter: 2145 CONFIG_SYS_PROMPT_HUSH_PS2 2146 2147 This defines the secondary prompt string, which is 2148 printed when the command interpreter needs more input 2149 to complete a command. Usually "> ". 2150 2151 Note: 2152 2153 In the current implementation, the local variables 2154 space and global environment variables space are 2155 separated. Local variables are those you define by 2156 simply typing `name=value'. To access a local 2157 variable later on, you have write `$name' or 2158 `${name}'; to execute the contents of a variable 2159 directly type `$name' at the command prompt. 2160 2161 Global environment variables are those you use 2162 setenv/printenv to work with. To run a command stored 2163 in such a variable, you need to use the run command, 2164 and you must not use the '$' sign to access them. 2165 2166 To store commands and special characters in a 2167 variable, please use double quotation marks 2168 surrounding the whole text of the variable, instead 2169 of the backslashes before semicolons and special 2170 symbols. 2171 2172- Command Line Editing and History: 2173 CONFIG_CMDLINE_PS_SUPPORT 2174 2175 Enable support for changing the command prompt string 2176 at run-time. Only static string is supported so far. 2177 The string is obtained from environment variables PS1 2178 and PS2. 2179 2180- Default Environment: 2181 CONFIG_EXTRA_ENV_SETTINGS 2182 2183 Define this to contain any number of null terminated 2184 strings (variable = value pairs) that will be part of 2185 the default environment compiled into the boot image. 2186 2187 For example, place something like this in your 2188 board's config file: 2189 2190 #define CONFIG_EXTRA_ENV_SETTINGS \ 2191 "myvar1=value1\0" \ 2192 "myvar2=value2\0" 2193 2194 Warning: This method is based on knowledge about the 2195 internal format how the environment is stored by the 2196 U-Boot code. This is NOT an official, exported 2197 interface! Although it is unlikely that this format 2198 will change soon, there is no guarantee either. 2199 You better know what you are doing here. 2200 2201 Note: overly (ab)use of the default environment is 2202 discouraged. Make sure to check other ways to preset 2203 the environment like the "source" command or the 2204 boot command first. 2205 2206 CONFIG_DELAY_ENVIRONMENT 2207 2208 Normally the environment is loaded when the board is 2209 initialised so that it is available to U-Boot. This inhibits 2210 that so that the environment is not available until 2211 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2212 this is instead controlled by the value of 2213 /config/load-environment. 2214 2215- Serial Flash support 2216 Usage requires an initial 'sf probe' to define the serial 2217 flash parameters, followed by read/write/erase/update 2218 commands. 2219 2220 The following defaults may be provided by the platform 2221 to handle the common case when only a single serial 2222 flash is present on the system. 2223 2224 CONFIG_SF_DEFAULT_BUS Bus identifier 2225 CONFIG_SF_DEFAULT_CS Chip-select 2226 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2227 CONFIG_SF_DEFAULT_SPEED in Hz 2228 2229 2230- TFTP Fixed UDP Port: 2231 CONFIG_TFTP_PORT 2232 2233 If this is defined, the environment variable tftpsrcp 2234 is used to supply the TFTP UDP source port value. 2235 If tftpsrcp isn't defined, the normal pseudo-random port 2236 number generator is used. 2237 2238 Also, the environment variable tftpdstp is used to supply 2239 the TFTP UDP destination port value. If tftpdstp isn't 2240 defined, the normal port 69 is used. 2241 2242 The purpose for tftpsrcp is to allow a TFTP server to 2243 blindly start the TFTP transfer using the pre-configured 2244 target IP address and UDP port. This has the effect of 2245 "punching through" the (Windows XP) firewall, allowing 2246 the remainder of the TFTP transfer to proceed normally. 2247 A better solution is to properly configure the firewall, 2248 but sometimes that is not allowed. 2249 2250- Show boot progress: 2251 CONFIG_SHOW_BOOT_PROGRESS 2252 2253 Defining this option allows to add some board- 2254 specific code (calling a user-provided function 2255 "show_boot_progress(int)") that enables you to show 2256 the system's boot progress on some display (for 2257 example, some LED's) on your board. At the moment, 2258 the following checkpoints are implemented: 2259 2260 2261Legacy uImage format: 2262 2263 Arg Where When 2264 1 common/cmd_bootm.c before attempting to boot an image 2265 -1 common/cmd_bootm.c Image header has bad magic number 2266 2 common/cmd_bootm.c Image header has correct magic number 2267 -2 common/cmd_bootm.c Image header has bad checksum 2268 3 common/cmd_bootm.c Image header has correct checksum 2269 -3 common/cmd_bootm.c Image data has bad checksum 2270 4 common/cmd_bootm.c Image data has correct checksum 2271 -4 common/cmd_bootm.c Image is for unsupported architecture 2272 5 common/cmd_bootm.c Architecture check OK 2273 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2274 6 common/cmd_bootm.c Image Type check OK 2275 -6 common/cmd_bootm.c gunzip uncompression error 2276 -7 common/cmd_bootm.c Unimplemented compression type 2277 7 common/cmd_bootm.c Uncompression OK 2278 8 common/cmd_bootm.c No uncompress/copy overwrite error 2279 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2280 2281 9 common/image.c Start initial ramdisk verification 2282 -10 common/image.c Ramdisk header has bad magic number 2283 -11 common/image.c Ramdisk header has bad checksum 2284 10 common/image.c Ramdisk header is OK 2285 -12 common/image.c Ramdisk data has bad checksum 2286 11 common/image.c Ramdisk data has correct checksum 2287 12 common/image.c Ramdisk verification complete, start loading 2288 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2289 13 common/image.c Start multifile image verification 2290 14 common/image.c No initial ramdisk, no multifile, continue. 2291 2292 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2293 2294 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2295 -31 post/post.c POST test failed, detected by post_output_backlog() 2296 -32 post/post.c POST test failed, detected by post_run_single() 2297 2298 34 common/cmd_doc.c before loading a Image from a DOC device 2299 -35 common/cmd_doc.c Bad usage of "doc" command 2300 35 common/cmd_doc.c correct usage of "doc" command 2301 -36 common/cmd_doc.c No boot device 2302 36 common/cmd_doc.c correct boot device 2303 -37 common/cmd_doc.c Unknown Chip ID on boot device 2304 37 common/cmd_doc.c correct chip ID found, device available 2305 -38 common/cmd_doc.c Read Error on boot device 2306 38 common/cmd_doc.c reading Image header from DOC device OK 2307 -39 common/cmd_doc.c Image header has bad magic number 2308 39 common/cmd_doc.c Image header has correct magic number 2309 -40 common/cmd_doc.c Error reading Image from DOC device 2310 40 common/cmd_doc.c Image header has correct magic number 2311 41 common/cmd_ide.c before loading a Image from a IDE device 2312 -42 common/cmd_ide.c Bad usage of "ide" command 2313 42 common/cmd_ide.c correct usage of "ide" command 2314 -43 common/cmd_ide.c No boot device 2315 43 common/cmd_ide.c boot device found 2316 -44 common/cmd_ide.c Device not available 2317 44 common/cmd_ide.c Device available 2318 -45 common/cmd_ide.c wrong partition selected 2319 45 common/cmd_ide.c partition selected 2320 -46 common/cmd_ide.c Unknown partition table 2321 46 common/cmd_ide.c valid partition table found 2322 -47 common/cmd_ide.c Invalid partition type 2323 47 common/cmd_ide.c correct partition type 2324 -48 common/cmd_ide.c Error reading Image Header on boot device 2325 48 common/cmd_ide.c reading Image Header from IDE device OK 2326 -49 common/cmd_ide.c Image header has bad magic number 2327 49 common/cmd_ide.c Image header has correct magic number 2328 -50 common/cmd_ide.c Image header has bad checksum 2329 50 common/cmd_ide.c Image header has correct checksum 2330 -51 common/cmd_ide.c Error reading Image from IDE device 2331 51 common/cmd_ide.c reading Image from IDE device OK 2332 52 common/cmd_nand.c before loading a Image from a NAND device 2333 -53 common/cmd_nand.c Bad usage of "nand" command 2334 53 common/cmd_nand.c correct usage of "nand" command 2335 -54 common/cmd_nand.c No boot device 2336 54 common/cmd_nand.c boot device found 2337 -55 common/cmd_nand.c Unknown Chip ID on boot device 2338 55 common/cmd_nand.c correct chip ID found, device available 2339 -56 common/cmd_nand.c Error reading Image Header on boot device 2340 56 common/cmd_nand.c reading Image Header from NAND device OK 2341 -57 common/cmd_nand.c Image header has bad magic number 2342 57 common/cmd_nand.c Image header has correct magic number 2343 -58 common/cmd_nand.c Error reading Image from NAND device 2344 58 common/cmd_nand.c reading Image from NAND device OK 2345 2346 -60 common/env_common.c Environment has a bad CRC, using default 2347 2348 64 net/eth.c starting with Ethernet configuration. 2349 -64 net/eth.c no Ethernet found. 2350 65 net/eth.c Ethernet found. 2351 2352 -80 common/cmd_net.c usage wrong 2353 80 common/cmd_net.c before calling net_loop() 2354 -81 common/cmd_net.c some error in net_loop() occurred 2355 81 common/cmd_net.c net_loop() back without error 2356 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2357 82 common/cmd_net.c trying automatic boot 2358 83 common/cmd_net.c running "source" command 2359 -83 common/cmd_net.c some error in automatic boot or "source" command 2360 84 common/cmd_net.c end without errors 2361 2362FIT uImage format: 2363 2364 Arg Where When 2365 100 common/cmd_bootm.c Kernel FIT Image has correct format 2366 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2367 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2368 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2369 102 common/cmd_bootm.c Kernel unit name specified 2370 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2371 103 common/cmd_bootm.c Found configuration node 2372 104 common/cmd_bootm.c Got kernel subimage node offset 2373 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2374 105 common/cmd_bootm.c Kernel subimage hash verification OK 2375 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2376 106 common/cmd_bootm.c Architecture check OK 2377 -106 common/cmd_bootm.c Kernel subimage has wrong type 2378 107 common/cmd_bootm.c Kernel subimage type OK 2379 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2380 108 common/cmd_bootm.c Got kernel subimage data/size 2381 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2382 -109 common/cmd_bootm.c Can't get kernel subimage type 2383 -110 common/cmd_bootm.c Can't get kernel subimage comp 2384 -111 common/cmd_bootm.c Can't get kernel subimage os 2385 -112 common/cmd_bootm.c Can't get kernel subimage load address 2386 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2387 2388 120 common/image.c Start initial ramdisk verification 2389 -120 common/image.c Ramdisk FIT image has incorrect format 2390 121 common/image.c Ramdisk FIT image has correct format 2391 122 common/image.c No ramdisk subimage unit name, using configuration 2392 -122 common/image.c Can't get configuration for ramdisk subimage 2393 123 common/image.c Ramdisk unit name specified 2394 -124 common/image.c Can't get ramdisk subimage node offset 2395 125 common/image.c Got ramdisk subimage node offset 2396 -125 common/image.c Ramdisk subimage hash verification failed 2397 126 common/image.c Ramdisk subimage hash verification OK 2398 -126 common/image.c Ramdisk subimage for unsupported architecture 2399 127 common/image.c Architecture check OK 2400 -127 common/image.c Can't get ramdisk subimage data/size 2401 128 common/image.c Got ramdisk subimage data/size 2402 129 common/image.c Can't get ramdisk load address 2403 -129 common/image.c Got ramdisk load address 2404 2405 -130 common/cmd_doc.c Incorrect FIT image format 2406 131 common/cmd_doc.c FIT image format OK 2407 2408 -140 common/cmd_ide.c Incorrect FIT image format 2409 141 common/cmd_ide.c FIT image format OK 2410 2411 -150 common/cmd_nand.c Incorrect FIT image format 2412 151 common/cmd_nand.c FIT image format OK 2413 2414- Standalone program support: 2415 CONFIG_STANDALONE_LOAD_ADDR 2416 2417 This option defines a board specific value for the 2418 address where standalone program gets loaded, thus 2419 overwriting the architecture dependent default 2420 settings. 2421 2422- Frame Buffer Address: 2423 CONFIG_FB_ADDR 2424 2425 Define CONFIG_FB_ADDR if you want to use specific 2426 address for frame buffer. This is typically the case 2427 when using a graphics controller has separate video 2428 memory. U-Boot will then place the frame buffer at 2429 the given address instead of dynamically reserving it 2430 in system RAM by calling lcd_setmem(), which grabs 2431 the memory for the frame buffer depending on the 2432 configured panel size. 2433 2434 Please see board_init_f function. 2435 2436- Automatic software updates via TFTP server 2437 CONFIG_UPDATE_TFTP 2438 CONFIG_UPDATE_TFTP_CNT_MAX 2439 CONFIG_UPDATE_TFTP_MSEC_MAX 2440 2441 These options enable and control the auto-update feature; 2442 for a more detailed description refer to doc/README.update. 2443 2444- MTD Support (mtdparts command, UBI support) 2445 CONFIG_MTD_DEVICE 2446 2447 Adds the MTD device infrastructure from the Linux kernel. 2448 Needed for mtdparts command support. 2449 2450 CONFIG_MTD_PARTITIONS 2451 2452 Adds the MTD partitioning infrastructure from the Linux 2453 kernel. Needed for UBI support. 2454 2455- UBI support 2456 CONFIG_MTD_UBI_WL_THRESHOLD 2457 This parameter defines the maximum difference between the highest 2458 erase counter value and the lowest erase counter value of eraseblocks 2459 of UBI devices. When this threshold is exceeded, UBI starts performing 2460 wear leveling by means of moving data from eraseblock with low erase 2461 counter to eraseblocks with high erase counter. 2462 2463 The default value should be OK for SLC NAND flashes, NOR flashes and 2464 other flashes which have eraseblock life-cycle 100000 or more. 2465 However, in case of MLC NAND flashes which typically have eraseblock 2466 life-cycle less than 10000, the threshold should be lessened (e.g., 2467 to 128 or 256, although it does not have to be power of 2). 2468 2469 default: 4096 2470 2471 CONFIG_MTD_UBI_BEB_LIMIT 2472 This option specifies the maximum bad physical eraseblocks UBI 2473 expects on the MTD device (per 1024 eraseblocks). If the 2474 underlying flash does not admit of bad eraseblocks (e.g. NOR 2475 flash), this value is ignored. 2476 2477 NAND datasheets often specify the minimum and maximum NVM 2478 (Number of Valid Blocks) for the flashes' endurance lifetime. 2479 The maximum expected bad eraseblocks per 1024 eraseblocks 2480 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2481 which gives 20 for most NANDs (MaxNVB is basically the total 2482 count of eraseblocks on the chip). 2483 2484 To put it differently, if this value is 20, UBI will try to 2485 reserve about 1.9% of physical eraseblocks for bad blocks 2486 handling. And that will be 1.9% of eraseblocks on the entire 2487 NAND chip, not just the MTD partition UBI attaches. This means 2488 that if you have, say, a NAND flash chip admits maximum 40 bad 2489 eraseblocks, and it is split on two MTD partitions of the same 2490 size, UBI will reserve 40 eraseblocks when attaching a 2491 partition. 2492 2493 default: 20 2494 2495 CONFIG_MTD_UBI_FASTMAP 2496 Fastmap is a mechanism which allows attaching an UBI device 2497 in nearly constant time. Instead of scanning the whole MTD device it 2498 only has to locate a checkpoint (called fastmap) on the device. 2499 The on-flash fastmap contains all information needed to attach 2500 the device. Using fastmap makes only sense on large devices where 2501 attaching by scanning takes long. UBI will not automatically install 2502 a fastmap on old images, but you can set the UBI parameter 2503 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2504 that fastmap-enabled images are still usable with UBI implementations 2505 without fastmap support. On typical flash devices the whole fastmap 2506 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2507 2508 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2509 Set this parameter to enable fastmap automatically on images 2510 without a fastmap. 2511 default: 0 2512 2513 CONFIG_MTD_UBI_FM_DEBUG 2514 Enable UBI fastmap debug 2515 default: 0 2516 2517- SPL framework 2518 CONFIG_SPL 2519 Enable building of SPL globally. 2520 2521 CONFIG_SPL_LDSCRIPT 2522 LDSCRIPT for linking the SPL binary. 2523 2524 CONFIG_SPL_MAX_FOOTPRINT 2525 Maximum size in memory allocated to the SPL, BSS included. 2526 When defined, the linker checks that the actual memory 2527 used by SPL from _start to __bss_end does not exceed it. 2528 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2529 must not be both defined at the same time. 2530 2531 CONFIG_SPL_MAX_SIZE 2532 Maximum size of the SPL image (text, data, rodata, and 2533 linker lists sections), BSS excluded. 2534 When defined, the linker checks that the actual size does 2535 not exceed it. 2536 2537 CONFIG_SPL_TEXT_BASE 2538 TEXT_BASE for linking the SPL binary. 2539 2540 CONFIG_SPL_RELOC_TEXT_BASE 2541 Address to relocate to. If unspecified, this is equal to 2542 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2543 2544 CONFIG_SPL_BSS_START_ADDR 2545 Link address for the BSS within the SPL binary. 2546 2547 CONFIG_SPL_BSS_MAX_SIZE 2548 Maximum size in memory allocated to the SPL BSS. 2549 When defined, the linker checks that the actual memory used 2550 by SPL from __bss_start to __bss_end does not exceed it. 2551 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2552 must not be both defined at the same time. 2553 2554 CONFIG_SPL_STACK 2555 Adress of the start of the stack SPL will use 2556 2557 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2558 When defined, SPL will panic() if the image it has 2559 loaded does not have a signature. 2560 Defining this is useful when code which loads images 2561 in SPL cannot guarantee that absolutely all read errors 2562 will be caught. 2563 An example is the LPC32XX MLC NAND driver, which will 2564 consider that a completely unreadable NAND block is bad, 2565 and thus should be skipped silently. 2566 2567 CONFIG_SPL_RELOC_STACK 2568 Adress of the start of the stack SPL will use after 2569 relocation. If unspecified, this is equal to 2570 CONFIG_SPL_STACK. 2571 2572 CONFIG_SYS_SPL_MALLOC_START 2573 Starting address of the malloc pool used in SPL. 2574 When this option is set the full malloc is used in SPL and 2575 it is set up by spl_init() and before that, the simple malloc() 2576 can be used if CONFIG_SYS_MALLOC_F is defined. 2577 2578 CONFIG_SYS_SPL_MALLOC_SIZE 2579 The size of the malloc pool used in SPL. 2580 2581 CONFIG_SPL_OS_BOOT 2582 Enable booting directly to an OS from SPL. 2583 See also: doc/README.falcon 2584 2585 CONFIG_SPL_DISPLAY_PRINT 2586 For ARM, enable an optional function to print more information 2587 about the running system. 2588 2589 CONFIG_SPL_INIT_MINIMAL 2590 Arch init code should be built for a very small image 2591 2592 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2593 Partition on the MMC to load U-Boot from when the MMC is being 2594 used in raw mode 2595 2596 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2597 Sector to load kernel uImage from when MMC is being 2598 used in raw mode (for Falcon mode) 2599 2600 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2601 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2602 Sector and number of sectors to load kernel argument 2603 parameters from when MMC is being used in raw mode 2604 (for falcon mode) 2605 2606 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2607 Partition on the MMC to load U-Boot from when the MMC is being 2608 used in fs mode 2609 2610 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2611 Filename to read to load U-Boot when reading from filesystem 2612 2613 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2614 Filename to read to load kernel uImage when reading 2615 from filesystem (for Falcon mode) 2616 2617 CONFIG_SPL_FS_LOAD_ARGS_NAME 2618 Filename to read to load kernel argument parameters 2619 when reading from filesystem (for Falcon mode) 2620 2621 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2622 Set this for NAND SPL on PPC mpc83xx targets, so that 2623 start.S waits for the rest of the SPL to load before 2624 continuing (the hardware starts execution after just 2625 loading the first page rather than the full 4K). 2626 2627 CONFIG_SPL_SKIP_RELOCATE 2628 Avoid SPL relocation 2629 2630 CONFIG_SPL_NAND_BASE 2631 Include nand_base.c in the SPL. Requires 2632 CONFIG_SPL_NAND_DRIVERS. 2633 2634 CONFIG_SPL_NAND_DRIVERS 2635 SPL uses normal NAND drivers, not minimal drivers. 2636 2637 CONFIG_SPL_NAND_ECC 2638 Include standard software ECC in the SPL 2639 2640 CONFIG_SPL_NAND_SIMPLE 2641 Support for NAND boot using simple NAND drivers that 2642 expose the cmd_ctrl() interface. 2643 2644 CONFIG_SPL_UBI 2645 Support for a lightweight UBI (fastmap) scanner and 2646 loader 2647 2648 CONFIG_SPL_NAND_RAW_ONLY 2649 Support to boot only raw u-boot.bin images. Use this only 2650 if you need to save space. 2651 2652 CONFIG_SPL_COMMON_INIT_DDR 2653 Set for common ddr init with serial presence detect in 2654 SPL binary. 2655 2656 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2657 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2658 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2659 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2660 CONFIG_SYS_NAND_ECCBYTES 2661 Defines the size and behavior of the NAND that SPL uses 2662 to read U-Boot 2663 2664 CONFIG_SPL_NAND_BOOT 2665 Add support NAND boot 2666 2667 CONFIG_SYS_NAND_U_BOOT_OFFS 2668 Location in NAND to read U-Boot from 2669 2670 CONFIG_SYS_NAND_U_BOOT_DST 2671 Location in memory to load U-Boot to 2672 2673 CONFIG_SYS_NAND_U_BOOT_SIZE 2674 Size of image to load 2675 2676 CONFIG_SYS_NAND_U_BOOT_START 2677 Entry point in loaded image to jump to 2678 2679 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2680 Define this if you need to first read the OOB and then the 2681 data. This is used, for example, on davinci platforms. 2682 2683 CONFIG_SPL_RAM_DEVICE 2684 Support for running image already present in ram, in SPL binary 2685 2686 CONFIG_SPL_PAD_TO 2687 Image offset to which the SPL should be padded before appending 2688 the SPL payload. By default, this is defined as 2689 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2690 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2691 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2692 2693 CONFIG_SPL_TARGET 2694 Final target image containing SPL and payload. Some SPLs 2695 use an arch-specific makefile fragment instead, for 2696 example if more than one image needs to be produced. 2697 2698 CONFIG_FIT_SPL_PRINT 2699 Printing information about a FIT image adds quite a bit of 2700 code to SPL. So this is normally disabled in SPL. Use this 2701 option to re-enable it. This will affect the output of the 2702 bootm command when booting a FIT image. 2703 2704- TPL framework 2705 CONFIG_TPL 2706 Enable building of TPL globally. 2707 2708 CONFIG_TPL_PAD_TO 2709 Image offset to which the TPL should be padded before appending 2710 the TPL payload. By default, this is defined as 2711 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2712 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2713 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2714 2715- Interrupt support (PPC): 2716 2717 There are common interrupt_init() and timer_interrupt() 2718 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2719 for CPU specific initialization. interrupt_init_cpu() 2720 should set decrementer_count to appropriate value. If 2721 CPU resets decrementer automatically after interrupt 2722 (ppc4xx) it should set decrementer_count to zero. 2723 timer_interrupt() calls timer_interrupt_cpu() for CPU 2724 specific handling. If board has watchdog / status_led 2725 / other_activity_monitor it works automatically from 2726 general timer_interrupt(). 2727 2728 2729Board initialization settings: 2730------------------------------ 2731 2732During Initialization u-boot calls a number of board specific functions 2733to allow the preparation of board specific prerequisites, e.g. pin setup 2734before drivers are initialized. To enable these callbacks the 2735following configuration macros have to be defined. Currently this is 2736architecture specific, so please check arch/your_architecture/lib/board.c 2737typically in board_init_f() and board_init_r(). 2738 2739- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2740- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2741- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2742- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2743 2744Configuration Settings: 2745----------------------- 2746 2747- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2748 Optionally it can be defined to support 64-bit memory commands. 2749 2750- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2751 undefine this when you're short of memory. 2752 2753- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2754 width of the commands listed in the 'help' command output. 2755 2756- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2757 prompt for user input. 2758 2759- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2760 2761- CONFIG_SYS_PBSIZE: Buffer size for Console output 2762 2763- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2764 2765- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2766 the application (usually a Linux kernel) when it is 2767 booted 2768 2769- CONFIG_SYS_BAUDRATE_TABLE: 2770 List of legal baudrate settings for this board. 2771 2772- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2773 Begin and End addresses of the area used by the 2774 simple memory test. 2775 2776- CONFIG_SYS_MEMTEST_SCRATCH: 2777 Scratch address used by the alternate memory test 2778 You only need to set this if address zero isn't writeable 2779 2780- CONFIG_SYS_MEM_RESERVE_SECURE 2781 Only implemented for ARMv8 for now. 2782 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2783 is substracted from total RAM and won't be reported to OS. 2784 This memory can be used as secure memory. A variable 2785 gd->arch.secure_ram is used to track the location. In systems 2786 the RAM base is not zero, or RAM is divided into banks, 2787 this variable needs to be recalcuated to get the address. 2788 2789- CONFIG_SYS_MEM_TOP_HIDE: 2790 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2791 this specified memory area will get subtracted from the top 2792 (end) of RAM and won't get "touched" at all by U-Boot. By 2793 fixing up gd->ram_size the Linux kernel should gets passed 2794 the now "corrected" memory size and won't touch it either. 2795 This should work for arch/ppc and arch/powerpc. Only Linux 2796 board ports in arch/powerpc with bootwrapper support that 2797 recalculate the memory size from the SDRAM controller setup 2798 will have to get fixed in Linux additionally. 2799 2800 This option can be used as a workaround for the 440EPx/GRx 2801 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2802 be touched. 2803 2804 WARNING: Please make sure that this value is a multiple of 2805 the Linux page size (normally 4k). If this is not the case, 2806 then the end address of the Linux memory will be located at a 2807 non page size aligned address and this could cause major 2808 problems. 2809 2810- CONFIG_SYS_LOADS_BAUD_CHANGE: 2811 Enable temporary baudrate change while serial download 2812 2813- CONFIG_SYS_SDRAM_BASE: 2814 Physical start address of SDRAM. _Must_ be 0 here. 2815 2816- CONFIG_SYS_FLASH_BASE: 2817 Physical start address of Flash memory. 2818 2819- CONFIG_SYS_MONITOR_BASE: 2820 Physical start address of boot monitor code (set by 2821 make config files to be same as the text base address 2822 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2823 CONFIG_SYS_FLASH_BASE when booting from flash. 2824 2825- CONFIG_SYS_MONITOR_LEN: 2826 Size of memory reserved for monitor code, used to 2827 determine _at_compile_time_ (!) if the environment is 2828 embedded within the U-Boot image, or in a separate 2829 flash sector. 2830 2831- CONFIG_SYS_MALLOC_LEN: 2832 Size of DRAM reserved for malloc() use. 2833 2834- CONFIG_SYS_MALLOC_F_LEN 2835 Size of the malloc() pool for use before relocation. If 2836 this is defined, then a very simple malloc() implementation 2837 will become available before relocation. The address is just 2838 below the global data, and the stack is moved down to make 2839 space. 2840 2841 This feature allocates regions with increasing addresses 2842 within the region. calloc() is supported, but realloc() 2843 is not available. free() is supported but does nothing. 2844 The memory will be freed (or in fact just forgotten) when 2845 U-Boot relocates itself. 2846 2847- CONFIG_SYS_MALLOC_SIMPLE 2848 Provides a simple and small malloc() and calloc() for those 2849 boards which do not use the full malloc in SPL (which is 2850 enabled with CONFIG_SYS_SPL_MALLOC_START). 2851 2852- CONFIG_SYS_NONCACHED_MEMORY: 2853 Size of non-cached memory area. This area of memory will be 2854 typically located right below the malloc() area and mapped 2855 uncached in the MMU. This is useful for drivers that would 2856 otherwise require a lot of explicit cache maintenance. For 2857 some drivers it's also impossible to properly maintain the 2858 cache. For example if the regions that need to be flushed 2859 are not a multiple of the cache-line size, *and* padding 2860 cannot be allocated between the regions to align them (i.e. 2861 if the HW requires a contiguous array of regions, and the 2862 size of each region is not cache-aligned), then a flush of 2863 one region may result in overwriting data that hardware has 2864 written to another region in the same cache-line. This can 2865 happen for example in network drivers where descriptors for 2866 buffers are typically smaller than the CPU cache-line (e.g. 2867 16 bytes vs. 32 or 64 bytes). 2868 2869 Non-cached memory is only supported on 32-bit ARM at present. 2870 2871- CONFIG_SYS_BOOTM_LEN: 2872 Normally compressed uImages are limited to an 2873 uncompressed size of 8 MBytes. If this is not enough, 2874 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2875 to adjust this setting to your needs. 2876 2877- CONFIG_SYS_BOOTMAPSZ: 2878 Maximum size of memory mapped by the startup code of 2879 the Linux kernel; all data that must be processed by 2880 the Linux kernel (bd_info, boot arguments, FDT blob if 2881 used) must be put below this limit, unless "bootm_low" 2882 environment variable is defined and non-zero. In such case 2883 all data for the Linux kernel must be between "bootm_low" 2884 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2885 variable "bootm_mapsize" will override the value of 2886 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2887 then the value in "bootm_size" will be used instead. 2888 2889- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2890 Enable initrd_high functionality. If defined then the 2891 initrd_high feature is enabled and the bootm ramdisk subcommand 2892 is enabled. 2893 2894- CONFIG_SYS_BOOT_GET_CMDLINE: 2895 Enables allocating and saving kernel cmdline in space between 2896 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2897 2898- CONFIG_SYS_BOOT_GET_KBD: 2899 Enables allocating and saving a kernel copy of the bd_info in 2900 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2901 2902- CONFIG_SYS_MAX_FLASH_BANKS: 2903 Max number of Flash memory banks 2904 2905- CONFIG_SYS_MAX_FLASH_SECT: 2906 Max number of sectors on a Flash chip 2907 2908- CONFIG_SYS_FLASH_ERASE_TOUT: 2909 Timeout for Flash erase operations (in ms) 2910 2911- CONFIG_SYS_FLASH_WRITE_TOUT: 2912 Timeout for Flash write operations (in ms) 2913 2914- CONFIG_SYS_FLASH_LOCK_TOUT 2915 Timeout for Flash set sector lock bit operation (in ms) 2916 2917- CONFIG_SYS_FLASH_UNLOCK_TOUT 2918 Timeout for Flash clear lock bits operation (in ms) 2919 2920- CONFIG_SYS_FLASH_PROTECTION 2921 If defined, hardware flash sectors protection is used 2922 instead of U-Boot software protection. 2923 2924- CONFIG_SYS_DIRECT_FLASH_TFTP: 2925 2926 Enable TFTP transfers directly to flash memory; 2927 without this option such a download has to be 2928 performed in two steps: (1) download to RAM, and (2) 2929 copy from RAM to flash. 2930 2931 The two-step approach is usually more reliable, since 2932 you can check if the download worked before you erase 2933 the flash, but in some situations (when system RAM is 2934 too limited to allow for a temporary copy of the 2935 downloaded image) this option may be very useful. 2936 2937- CONFIG_SYS_FLASH_CFI: 2938 Define if the flash driver uses extra elements in the 2939 common flash structure for storing flash geometry. 2940 2941- CONFIG_FLASH_CFI_DRIVER 2942 This option also enables the building of the cfi_flash driver 2943 in the drivers directory 2944 2945- CONFIG_FLASH_CFI_MTD 2946 This option enables the building of the cfi_mtd driver 2947 in the drivers directory. The driver exports CFI flash 2948 to the MTD layer. 2949 2950- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2951 Use buffered writes to flash. 2952 2953- CONFIG_FLASH_SPANSION_S29WS_N 2954 s29ws-n MirrorBit flash has non-standard addresses for buffered 2955 write commands. 2956 2957- CONFIG_SYS_FLASH_QUIET_TEST 2958 If this option is defined, the common CFI flash doesn't 2959 print it's warning upon not recognized FLASH banks. This 2960 is useful, if some of the configured banks are only 2961 optionally available. 2962 2963- CONFIG_FLASH_SHOW_PROGRESS 2964 If defined (must be an integer), print out countdown 2965 digits and dots. Recommended value: 45 (9..1) for 80 2966 column displays, 15 (3..1) for 40 column displays. 2967 2968- CONFIG_FLASH_VERIFY 2969 If defined, the content of the flash (destination) is compared 2970 against the source after the write operation. An error message 2971 will be printed when the contents are not identical. 2972 Please note that this option is useless in nearly all cases, 2973 since such flash programming errors usually are detected earlier 2974 while unprotecting/erasing/programming. Please only enable 2975 this option if you really know what you are doing. 2976 2977- CONFIG_SYS_RX_ETH_BUFFER: 2978 Defines the number of Ethernet receive buffers. On some 2979 Ethernet controllers it is recommended to set this value 2980 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2981 buffers can be full shortly after enabling the interface 2982 on high Ethernet traffic. 2983 Defaults to 4 if not defined. 2984 2985- CONFIG_ENV_MAX_ENTRIES 2986 2987 Maximum number of entries in the hash table that is used 2988 internally to store the environment settings. The default 2989 setting is supposed to be generous and should work in most 2990 cases. This setting can be used to tune behaviour; see 2991 lib/hashtable.c for details. 2992 2993- CONFIG_ENV_FLAGS_LIST_DEFAULT 2994- CONFIG_ENV_FLAGS_LIST_STATIC 2995 Enable validation of the values given to environment variables when 2996 calling env set. Variables can be restricted to only decimal, 2997 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 2998 the variables can also be restricted to IP address or MAC address. 2999 3000 The format of the list is: 3001 type_attribute = [s|d|x|b|i|m] 3002 access_attribute = [a|r|o|c] 3003 attributes = type_attribute[access_attribute] 3004 entry = variable_name[:attributes] 3005 list = entry[,list] 3006 3007 The type attributes are: 3008 s - String (default) 3009 d - Decimal 3010 x - Hexadecimal 3011 b - Boolean ([1yYtT|0nNfF]) 3012 i - IP address 3013 m - MAC address 3014 3015 The access attributes are: 3016 a - Any (default) 3017 r - Read-only 3018 o - Write-once 3019 c - Change-default 3020 3021 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3022 Define this to a list (string) to define the ".flags" 3023 environment variable in the default or embedded environment. 3024 3025 - CONFIG_ENV_FLAGS_LIST_STATIC 3026 Define this to a list (string) to define validation that 3027 should be done if an entry is not found in the ".flags" 3028 environment variable. To override a setting in the static 3029 list, simply add an entry for the same variable name to the 3030 ".flags" variable. 3031 3032 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3033 regular expression. This allows multiple variables to define the same 3034 flags without explicitly listing them for each variable. 3035 3036- CONFIG_ENV_ACCESS_IGNORE_FORCE 3037 If defined, don't allow the -f switch to env set override variable 3038 access flags. 3039 3040- CONFIG_USE_STDINT 3041 If stdint.h is available with your toolchain you can define this 3042 option to enable it. You can provide option 'USE_STDINT=1' when 3043 building U-Boot to enable this. 3044 3045The following definitions that deal with the placement and management 3046of environment data (variable area); in general, we support the 3047following configurations: 3048 3049- CONFIG_BUILD_ENVCRC: 3050 3051 Builds up envcrc with the target environment so that external utils 3052 may easily extract it and embed it in final U-Boot images. 3053 3054BE CAREFUL! The first access to the environment happens quite early 3055in U-Boot initialization (when we try to get the setting of for the 3056console baudrate). You *MUST* have mapped your NVRAM area then, or 3057U-Boot will hang. 3058 3059Please note that even with NVRAM we still use a copy of the 3060environment in RAM: we could work on NVRAM directly, but we want to 3061keep settings there always unmodified except somebody uses "saveenv" 3062to save the current settings. 3063 3064BE CAREFUL! For some special cases, the local device can not use 3065"saveenv" command. For example, the local device will get the 3066environment stored in a remote NOR flash by SRIO or PCIE link, 3067but it can not erase, write this NOR flash by SRIO or PCIE interface. 3068 3069- CONFIG_NAND_ENV_DST 3070 3071 Defines address in RAM to which the nand_spl code should copy the 3072 environment. If redundant environment is used, it will be copied to 3073 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3074 3075Please note that the environment is read-only until the monitor 3076has been relocated to RAM and a RAM copy of the environment has been 3077created; also, when using EEPROM you will have to use env_get_f() 3078until then to read environment variables. 3079 3080The environment is protected by a CRC32 checksum. Before the monitor 3081is relocated into RAM, as a result of a bad CRC you will be working 3082with the compiled-in default environment - *silently*!!! [This is 3083necessary, because the first environment variable we need is the 3084"baudrate" setting for the console - if we have a bad CRC, we don't 3085have any device yet where we could complain.] 3086 3087Note: once the monitor has been relocated, then it will complain if 3088the default environment is used; a new CRC is computed as soon as you 3089use the "saveenv" command to store a valid environment. 3090 3091- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3092 Echo the inverted Ethernet link state to the fault LED. 3093 3094 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3095 also needs to be defined. 3096 3097- CONFIG_SYS_FAULT_MII_ADDR: 3098 MII address of the PHY to check for the Ethernet link state. 3099 3100- CONFIG_NS16550_MIN_FUNCTIONS: 3101 Define this if you desire to only have use of the NS16550_init 3102 and NS16550_putc functions for the serial driver located at 3103 drivers/serial/ns16550.c. This option is useful for saving 3104 space for already greatly restricted images, including but not 3105 limited to NAND_SPL configurations. 3106 3107- CONFIG_DISPLAY_BOARDINFO 3108 Display information about the board that U-Boot is running on 3109 when U-Boot starts up. The board function checkboard() is called 3110 to do this. 3111 3112- CONFIG_DISPLAY_BOARDINFO_LATE 3113 Similar to the previous option, but display this information 3114 later, once stdio is running and output goes to the LCD, if 3115 present. 3116 3117- CONFIG_BOARD_SIZE_LIMIT: 3118 Maximum size of the U-Boot image. When defined, the 3119 build system checks that the actual size does not 3120 exceed it. 3121 3122Low Level (hardware related) configuration options: 3123--------------------------------------------------- 3124 3125- CONFIG_SYS_CACHELINE_SIZE: 3126 Cache Line Size of the CPU. 3127 3128- CONFIG_SYS_CCSRBAR_DEFAULT: 3129 Default (power-on reset) physical address of CCSR on Freescale 3130 PowerPC SOCs. 3131 3132- CONFIG_SYS_CCSRBAR: 3133 Virtual address of CCSR. On a 32-bit build, this is typically 3134 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3135 3136- CONFIG_SYS_CCSRBAR_PHYS: 3137 Physical address of CCSR. CCSR can be relocated to a new 3138 physical address, if desired. In this case, this macro should 3139 be set to that address. Otherwise, it should be set to the 3140 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3141 is typically relocated on 36-bit builds. It is recommended 3142 that this macro be defined via the _HIGH and _LOW macros: 3143 3144 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3145 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3146 3147- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3148 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3149 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3150 used in assembly code, so it must not contain typecasts or 3151 integer size suffixes (e.g. "ULL"). 3152 3153- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3154 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3155 used in assembly code, so it must not contain typecasts or 3156 integer size suffixes (e.g. "ULL"). 3157 3158- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3159 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3160 forced to a value that ensures that CCSR is not relocated. 3161 3162- Floppy Disk Support: 3163 CONFIG_SYS_FDC_DRIVE_NUMBER 3164 3165 the default drive number (default value 0) 3166 3167 CONFIG_SYS_ISA_IO_STRIDE 3168 3169 defines the spacing between FDC chipset registers 3170 (default value 1) 3171 3172 CONFIG_SYS_ISA_IO_OFFSET 3173 3174 defines the offset of register from address. It 3175 depends on which part of the data bus is connected to 3176 the FDC chipset. (default value 0) 3177 3178 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3179 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3180 default value. 3181 3182 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3183 fdc_hw_init() is called at the beginning of the FDC 3184 setup. fdc_hw_init() must be provided by the board 3185 source code. It is used to make hardware-dependent 3186 initializations. 3187 3188- CONFIG_IDE_AHB: 3189 Most IDE controllers were designed to be connected with PCI 3190 interface. Only few of them were designed for AHB interface. 3191 When software is doing ATA command and data transfer to 3192 IDE devices through IDE-AHB controller, some additional 3193 registers accessing to these kind of IDE-AHB controller 3194 is required. 3195 3196- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3197 DO NOT CHANGE unless you know exactly what you're 3198 doing! (11-4) [MPC8xx systems only] 3199 3200- CONFIG_SYS_INIT_RAM_ADDR: 3201 3202 Start address of memory area that can be used for 3203 initial data and stack; please note that this must be 3204 writable memory that is working WITHOUT special 3205 initialization, i. e. you CANNOT use normal RAM which 3206 will become available only after programming the 3207 memory controller and running certain initialization 3208 sequences. 3209 3210 U-Boot uses the following memory types: 3211 - MPC8xx: IMMR (internal memory of the CPU) 3212 3213- CONFIG_SYS_GBL_DATA_OFFSET: 3214 3215 Offset of the initial data structure in the memory 3216 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3217 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3218 data is located at the end of the available space 3219 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3220 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3221 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3222 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3223 3224 Note: 3225 On the MPC824X (or other systems that use the data 3226 cache for initial memory) the address chosen for 3227 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3228 point to an otherwise UNUSED address space between 3229 the top of RAM and the start of the PCI space. 3230 3231- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3232 3233- CONFIG_SYS_OR_TIMING_SDRAM: 3234 SDRAM timing 3235 3236- CONFIG_SYS_MAMR_PTA: 3237 periodic timer for refresh 3238 3239- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3240 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3241 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3242 CONFIG_SYS_BR1_PRELIM: 3243 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3244 3245- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3246 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3247 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3248 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3249 3250- CONFIG_PCI_ENUM_ONLY 3251 Only scan through and get the devices on the buses. 3252 Don't do any setup work, presumably because someone or 3253 something has already done it, and we don't need to do it 3254 a second time. Useful for platforms that are pre-booted 3255 by coreboot or similar. 3256 3257- CONFIG_PCI_INDIRECT_BRIDGE: 3258 Enable support for indirect PCI bridges. 3259 3260- CONFIG_SYS_SRIO: 3261 Chip has SRIO or not 3262 3263- CONFIG_SRIO1: 3264 Board has SRIO 1 port available 3265 3266- CONFIG_SRIO2: 3267 Board has SRIO 2 port available 3268 3269- CONFIG_SRIO_PCIE_BOOT_MASTER 3270 Board can support master function for Boot from SRIO and PCIE 3271 3272- CONFIG_SYS_SRIOn_MEM_VIRT: 3273 Virtual Address of SRIO port 'n' memory region 3274 3275- CONFIG_SYS_SRIOn_MEM_PHYS: 3276 Physical Address of SRIO port 'n' memory region 3277 3278- CONFIG_SYS_SRIOn_MEM_SIZE: 3279 Size of SRIO port 'n' memory region 3280 3281- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3282 Defined to tell the NAND controller that the NAND chip is using 3283 a 16 bit bus. 3284 Not all NAND drivers use this symbol. 3285 Example of drivers that use it: 3286 - drivers/mtd/nand/ndfc.c 3287 - drivers/mtd/nand/mxc_nand.c 3288 3289- CONFIG_SYS_NDFC_EBC0_CFG 3290 Sets the EBC0_CFG register for the NDFC. If not defined 3291 a default value will be used. 3292 3293- CONFIG_SPD_EEPROM 3294 Get DDR timing information from an I2C EEPROM. Common 3295 with pluggable memory modules such as SODIMMs 3296 3297 SPD_EEPROM_ADDRESS 3298 I2C address of the SPD EEPROM 3299 3300- CONFIG_SYS_SPD_BUS_NUM 3301 If SPD EEPROM is on an I2C bus other than the first 3302 one, specify here. Note that the value must resolve 3303 to something your driver can deal with. 3304 3305- CONFIG_SYS_DDR_RAW_TIMING 3306 Get DDR timing information from other than SPD. Common with 3307 soldered DDR chips onboard without SPD. DDR raw timing 3308 parameters are extracted from datasheet and hard-coded into 3309 header files or board specific files. 3310 3311- CONFIG_FSL_DDR_INTERACTIVE 3312 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3313 3314- CONFIG_FSL_DDR_SYNC_REFRESH 3315 Enable sync of refresh for multiple controllers. 3316 3317- CONFIG_FSL_DDR_BIST 3318 Enable built-in memory test for Freescale DDR controllers. 3319 3320- CONFIG_SYS_83XX_DDR_USES_CS0 3321 Only for 83xx systems. If specified, then DDR should 3322 be configured using CS0 and CS1 instead of CS2 and CS3. 3323 3324- CONFIG_RMII 3325 Enable RMII mode for all FECs. 3326 Note that this is a global option, we can't 3327 have one FEC in standard MII mode and another in RMII mode. 3328 3329- CONFIG_CRC32_VERIFY 3330 Add a verify option to the crc32 command. 3331 The syntax is: 3332 3333 => crc32 -v <address> <count> <crc32> 3334 3335 Where address/count indicate a memory area 3336 and crc32 is the correct crc32 which the 3337 area should have. 3338 3339- CONFIG_LOOPW 3340 Add the "loopw" memory command. This only takes effect if 3341 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3342 3343- CONFIG_MX_CYCLIC 3344 Add the "mdc" and "mwc" memory commands. These are cyclic 3345 "md/mw" commands. 3346 Examples: 3347 3348 => mdc.b 10 4 500 3349 This command will print 4 bytes (10,11,12,13) each 500 ms. 3350 3351 => mwc.l 100 12345678 10 3352 This command will write 12345678 to address 100 all 10 ms. 3353 3354 This only takes effect if the memory commands are activated 3355 globally (CONFIG_CMD_MEMORY). 3356 3357- CONFIG_SKIP_LOWLEVEL_INIT 3358 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3359 low level initializations (like setting up the memory 3360 controller) are omitted and/or U-Boot does not 3361 relocate itself into RAM. 3362 3363 Normally this variable MUST NOT be defined. The only 3364 exception is when U-Boot is loaded (to RAM) by some 3365 other boot loader or by a debugger which performs 3366 these initializations itself. 3367 3368- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3369 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3370 to be skipped. The normal CP15 init (such as enabling the 3371 instruction cache) is still performed. 3372 3373- CONFIG_SPL_BUILD 3374 Modifies the behaviour of start.S when compiling a loader 3375 that is executed before the actual U-Boot. E.g. when 3376 compiling a NAND SPL. 3377 3378- CONFIG_TPL_BUILD 3379 Modifies the behaviour of start.S when compiling a loader 3380 that is executed after the SPL and before the actual U-Boot. 3381 It is loaded by the SPL. 3382 3383- CONFIG_SYS_MPC85XX_NO_RESETVEC 3384 Only for 85xx systems. If this variable is specified, the section 3385 .resetvec is not kept and the section .bootpg is placed in the 3386 previous 4k of the .text section. 3387 3388- CONFIG_ARCH_MAP_SYSMEM 3389 Generally U-Boot (and in particular the md command) uses 3390 effective address. It is therefore not necessary to regard 3391 U-Boot address as virtual addresses that need to be translated 3392 to physical addresses. However, sandbox requires this, since 3393 it maintains its own little RAM buffer which contains all 3394 addressable memory. This option causes some memory accesses 3395 to be mapped through map_sysmem() / unmap_sysmem(). 3396 3397- CONFIG_X86_RESET_VECTOR 3398 If defined, the x86 reset vector code is included. This is not 3399 needed when U-Boot is running from Coreboot. 3400 3401- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3402 Option to disable subpage write in NAND driver 3403 driver that uses this: 3404 drivers/mtd/nand/davinci_nand.c 3405 3406Freescale QE/FMAN Firmware Support: 3407----------------------------------- 3408 3409The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3410loading of "firmware", which is encoded in the QE firmware binary format. 3411This firmware often needs to be loaded during U-Boot booting, so macros 3412are used to identify the storage device (NOR flash, SPI, etc) and the address 3413within that device. 3414 3415- CONFIG_SYS_FMAN_FW_ADDR 3416 The address in the storage device where the FMAN microcode is located. The 3417 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3418 is also specified. 3419 3420- CONFIG_SYS_QE_FW_ADDR 3421 The address in the storage device where the QE microcode is located. The 3422 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3423 is also specified. 3424 3425- CONFIG_SYS_QE_FMAN_FW_LENGTH 3426 The maximum possible size of the firmware. The firmware binary format 3427 has a field that specifies the actual size of the firmware, but it 3428 might not be possible to read any part of the firmware unless some 3429 local storage is allocated to hold the entire firmware first. 3430 3431- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3432 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3433 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3434 virtual address in NOR flash. 3435 3436- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3437 Specifies that QE/FMAN firmware is located in NAND flash. 3438 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3439 3440- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3441 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3442 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3443 3444- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3445 Specifies that QE/FMAN firmware is located in the remote (master) 3446 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3447 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3448 window->master inbound window->master LAW->the ucode address in 3449 master's memory space. 3450 3451Freescale Layerscape Management Complex Firmware Support: 3452--------------------------------------------------------- 3453The Freescale Layerscape Management Complex (MC) supports the loading of 3454"firmware". 3455This firmware often needs to be loaded during U-Boot booting, so macros 3456are used to identify the storage device (NOR flash, SPI, etc) and the address 3457within that device. 3458 3459- CONFIG_FSL_MC_ENET 3460 Enable the MC driver for Layerscape SoCs. 3461 3462Freescale Layerscape Debug Server Support: 3463------------------------------------------- 3464The Freescale Layerscape Debug Server Support supports the loading of 3465"Debug Server firmware" and triggering SP boot-rom. 3466This firmware often needs to be loaded during U-Boot booting. 3467 3468- CONFIG_SYS_MC_RSV_MEM_ALIGN 3469 Define alignment of reserved memory MC requires 3470 3471Reproducible builds 3472------------------- 3473 3474In order to achieve reproducible builds, timestamps used in the U-Boot build 3475process have to be set to a fixed value. 3476 3477This is done using the SOURCE_DATE_EPOCH environment variable. 3478SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3479option for U-Boot or an environment variable in U-Boot. 3480 3481SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3482 3483Building the Software: 3484====================== 3485 3486Building U-Boot has been tested in several native build environments 3487and in many different cross environments. Of course we cannot support 3488all possibly existing versions of cross development tools in all 3489(potentially obsolete) versions. In case of tool chain problems we 3490recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3491which is extensively used to build and test U-Boot. 3492 3493If you are not using a native environment, it is assumed that you 3494have GNU cross compiling tools available in your path. In this case, 3495you must set the environment variable CROSS_COMPILE in your shell. 3496Note that no changes to the Makefile or any other source files are 3497necessary. For example using the ELDK on a 4xx CPU, please enter: 3498 3499 $ CROSS_COMPILE=ppc_4xx- 3500 $ export CROSS_COMPILE 3501 3502Note: If you wish to generate Windows versions of the utilities in 3503 the tools directory you can use the MinGW toolchain 3504 (http://www.mingw.org). Set your HOST tools to the MinGW 3505 toolchain and execute 'make tools'. For example: 3506 3507 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3508 3509 Binaries such as tools/mkimage.exe will be created which can 3510 be executed on computers running Windows. 3511 3512U-Boot is intended to be simple to build. After installing the 3513sources you must configure U-Boot for one specific board type. This 3514is done by typing: 3515 3516 make NAME_defconfig 3517 3518where "NAME_defconfig" is the name of one of the existing configu- 3519rations; see boards.cfg for supported names. 3520 3521Note: for some board special configuration names may exist; check if 3522 additional information is available from the board vendor; for 3523 instance, the TQM823L systems are available without (standard) 3524 or with LCD support. You can select such additional "features" 3525 when choosing the configuration, i. e. 3526 3527 make TQM823L_defconfig 3528 - will configure for a plain TQM823L, i. e. no LCD support 3529 3530 make TQM823L_LCD_defconfig 3531 - will configure for a TQM823L with U-Boot console on LCD 3532 3533 etc. 3534 3535 3536Finally, type "make all", and you should get some working U-Boot 3537images ready for download to / installation on your system: 3538 3539- "u-boot.bin" is a raw binary image 3540- "u-boot" is an image in ELF binary format 3541- "u-boot.srec" is in Motorola S-Record format 3542 3543By default the build is performed locally and the objects are saved 3544in the source directory. One of the two methods can be used to change 3545this behavior and build U-Boot to some external directory: 3546 35471. Add O= to the make command line invocations: 3548 3549 make O=/tmp/build distclean 3550 make O=/tmp/build NAME_defconfig 3551 make O=/tmp/build all 3552 35532. Set environment variable KBUILD_OUTPUT to point to the desired location: 3554 3555 export KBUILD_OUTPUT=/tmp/build 3556 make distclean 3557 make NAME_defconfig 3558 make all 3559 3560Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3561variable. 3562 3563User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3564setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3565For example to treat all compiler warnings as errors: 3566 3567 make KCFLAGS=-Werror 3568 3569Please be aware that the Makefiles assume you are using GNU make, so 3570for instance on NetBSD you might need to use "gmake" instead of 3571native "make". 3572 3573 3574If the system board that you have is not listed, then you will need 3575to port U-Boot to your hardware platform. To do this, follow these 3576steps: 3577 35781. Create a new directory to hold your board specific code. Add any 3579 files you need. In your board directory, you will need at least 3580 the "Makefile" and a "<board>.c". 35812. Create a new configuration file "include/configs/<board>.h" for 3582 your board. 35833. If you're porting U-Boot to a new CPU, then also create a new 3584 directory to hold your CPU specific code. Add any files you need. 35854. Run "make <board>_defconfig" with your new name. 35865. Type "make", and you should get a working "u-boot.srec" file 3587 to be installed on your target system. 35886. Debug and solve any problems that might arise. 3589 [Of course, this last step is much harder than it sounds.] 3590 3591 3592Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3593============================================================== 3594 3595If you have modified U-Boot sources (for instance added a new board 3596or support for new devices, a new CPU, etc.) you are expected to 3597provide feedback to the other developers. The feedback normally takes 3598the form of a "patch", i. e. a context diff against a certain (latest 3599official or latest in the git repository) version of U-Boot sources. 3600 3601But before you submit such a patch, please verify that your modifi- 3602cation did not break existing code. At least make sure that *ALL* of 3603the supported boards compile WITHOUT ANY compiler warnings. To do so, 3604just run the buildman script (tools/buildman/buildman), which will 3605configure and build U-Boot for ALL supported system. Be warned, this 3606will take a while. Please see the buildman README, or run 'buildman -H' 3607for documentation. 3608 3609 3610See also "U-Boot Porting Guide" below. 3611 3612 3613Monitor Commands - Overview: 3614============================ 3615 3616go - start application at address 'addr' 3617run - run commands in an environment variable 3618bootm - boot application image from memory 3619bootp - boot image via network using BootP/TFTP protocol 3620bootz - boot zImage from memory 3621tftpboot- boot image via network using TFTP protocol 3622 and env variables "ipaddr" and "serverip" 3623 (and eventually "gatewayip") 3624tftpput - upload a file via network using TFTP protocol 3625rarpboot- boot image via network using RARP/TFTP protocol 3626diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3627loads - load S-Record file over serial line 3628loadb - load binary file over serial line (kermit mode) 3629md - memory display 3630mm - memory modify (auto-incrementing) 3631nm - memory modify (constant address) 3632mw - memory write (fill) 3633cp - memory copy 3634cmp - memory compare 3635crc32 - checksum calculation 3636i2c - I2C sub-system 3637sspi - SPI utility commands 3638base - print or set address offset 3639printenv- print environment variables 3640setenv - set environment variables 3641saveenv - save environment variables to persistent storage 3642protect - enable or disable FLASH write protection 3643erase - erase FLASH memory 3644flinfo - print FLASH memory information 3645nand - NAND memory operations (see doc/README.nand) 3646bdinfo - print Board Info structure 3647iminfo - print header information for application image 3648coninfo - print console devices and informations 3649ide - IDE sub-system 3650loop - infinite loop on address range 3651loopw - infinite write loop on address range 3652mtest - simple RAM test 3653icache - enable or disable instruction cache 3654dcache - enable or disable data cache 3655reset - Perform RESET of the CPU 3656echo - echo args to console 3657version - print monitor version 3658help - print online help 3659? - alias for 'help' 3660 3661 3662Monitor Commands - Detailed Description: 3663======================================== 3664 3665TODO. 3666 3667For now: just type "help <command>". 3668 3669 3670Environment Variables: 3671====================== 3672 3673U-Boot supports user configuration using Environment Variables which 3674can be made persistent by saving to Flash memory. 3675 3676Environment Variables are set using "setenv", printed using 3677"printenv", and saved to Flash using "saveenv". Using "setenv" 3678without a value can be used to delete a variable from the 3679environment. As long as you don't save the environment you are 3680working with an in-memory copy. In case the Flash area containing the 3681environment is erased by accident, a default environment is provided. 3682 3683Some configuration options can be set using Environment Variables. 3684 3685List of environment variables (most likely not complete): 3686 3687 baudrate - see CONFIG_BAUDRATE 3688 3689 bootdelay - see CONFIG_BOOTDELAY 3690 3691 bootcmd - see CONFIG_BOOTCOMMAND 3692 3693 bootargs - Boot arguments when booting an RTOS image 3694 3695 bootfile - Name of the image to load with TFTP 3696 3697 bootm_low - Memory range available for image processing in the bootm 3698 command can be restricted. This variable is given as 3699 a hexadecimal number and defines lowest address allowed 3700 for use by the bootm command. See also "bootm_size" 3701 environment variable. Address defined by "bootm_low" is 3702 also the base of the initial memory mapping for the Linux 3703 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3704 bootm_mapsize. 3705 3706 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3707 This variable is given as a hexadecimal number and it 3708 defines the size of the memory region starting at base 3709 address bootm_low that is accessible by the Linux kernel 3710 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3711 as the default value if it is defined, and bootm_size is 3712 used otherwise. 3713 3714 bootm_size - Memory range available for image processing in the bootm 3715 command can be restricted. This variable is given as 3716 a hexadecimal number and defines the size of the region 3717 allowed for use by the bootm command. See also "bootm_low" 3718 environment variable. 3719 3720 updatefile - Location of the software update file on a TFTP server, used 3721 by the automatic software update feature. Please refer to 3722 documentation in doc/README.update for more details. 3723 3724 autoload - if set to "no" (any string beginning with 'n'), 3725 "bootp" will just load perform a lookup of the 3726 configuration from the BOOTP server, but not try to 3727 load any image using TFTP 3728 3729 autostart - if set to "yes", an image loaded using the "bootp", 3730 "rarpboot", "tftpboot" or "diskboot" commands will 3731 be automatically started (by internally calling 3732 "bootm") 3733 3734 If set to "no", a standalone image passed to the 3735 "bootm" command will be copied to the load address 3736 (and eventually uncompressed), but NOT be started. 3737 This can be used to load and uncompress arbitrary 3738 data. 3739 3740 fdt_high - if set this restricts the maximum address that the 3741 flattened device tree will be copied into upon boot. 3742 For example, if you have a system with 1 GB memory 3743 at physical address 0x10000000, while Linux kernel 3744 only recognizes the first 704 MB as low memory, you 3745 may need to set fdt_high as 0x3C000000 to have the 3746 device tree blob be copied to the maximum address 3747 of the 704 MB low memory, so that Linux kernel can 3748 access it during the boot procedure. 3749 3750 If this is set to the special value 0xFFFFFFFF then 3751 the fdt will not be copied at all on boot. For this 3752 to work it must reside in writable memory, have 3753 sufficient padding on the end of it for u-boot to 3754 add the information it needs into it, and the memory 3755 must be accessible by the kernel. 3756 3757 fdtcontroladdr- if set this is the address of the control flattened 3758 device tree used by U-Boot when CONFIG_OF_CONTROL is 3759 defined. 3760 3761 i2cfast - (PPC405GP|PPC405EP only) 3762 if set to 'y' configures Linux I2C driver for fast 3763 mode (400kHZ). This environment variable is used in 3764 initialization code. So, for changes to be effective 3765 it must be saved and board must be reset. 3766 3767 initrd_high - restrict positioning of initrd images: 3768 If this variable is not set, initrd images will be 3769 copied to the highest possible address in RAM; this 3770 is usually what you want since it allows for 3771 maximum initrd size. If for some reason you want to 3772 make sure that the initrd image is loaded below the 3773 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3774 variable to a value of "no" or "off" or "0". 3775 Alternatively, you can set it to a maximum upper 3776 address to use (U-Boot will still check that it 3777 does not overwrite the U-Boot stack and data). 3778 3779 For instance, when you have a system with 16 MB 3780 RAM, and want to reserve 4 MB from use by Linux, 3781 you can do this by adding "mem=12M" to the value of 3782 the "bootargs" variable. However, now you must make 3783 sure that the initrd image is placed in the first 3784 12 MB as well - this can be done with 3785 3786 setenv initrd_high 00c00000 3787 3788 If you set initrd_high to 0xFFFFFFFF, this is an 3789 indication to U-Boot that all addresses are legal 3790 for the Linux kernel, including addresses in flash 3791 memory. In this case U-Boot will NOT COPY the 3792 ramdisk at all. This may be useful to reduce the 3793 boot time on your system, but requires that this 3794 feature is supported by your Linux kernel. 3795 3796 ipaddr - IP address; needed for tftpboot command 3797 3798 loadaddr - Default load address for commands like "bootp", 3799 "rarpboot", "tftpboot", "loadb" or "diskboot" 3800 3801 loads_echo - see CONFIG_LOADS_ECHO 3802 3803 serverip - TFTP server IP address; needed for tftpboot command 3804 3805 bootretry - see CONFIG_BOOT_RETRY_TIME 3806 3807 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3808 3809 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3810 3811 ethprime - controls which interface is used first. 3812 3813 ethact - controls which interface is currently active. 3814 For example you can do the following 3815 3816 => setenv ethact FEC 3817 => ping 192.168.0.1 # traffic sent on FEC 3818 => setenv ethact SCC 3819 => ping 10.0.0.1 # traffic sent on SCC 3820 3821 ethrotate - When set to "no" U-Boot does not go through all 3822 available network interfaces. 3823 It just stays at the currently selected interface. 3824 3825 netretry - When set to "no" each network operation will 3826 either succeed or fail without retrying. 3827 When set to "once" the network operation will 3828 fail when all the available network interfaces 3829 are tried once without success. 3830 Useful on scripts which control the retry operation 3831 themselves. 3832 3833 npe_ucode - set load address for the NPE microcode 3834 3835 silent_linux - If set then Linux will be told to boot silently, by 3836 changing the console to be empty. If "yes" it will be 3837 made silent. If "no" it will not be made silent. If 3838 unset, then it will be made silent if the U-Boot console 3839 is silent. 3840 3841 tftpsrcp - If this is set, the value is used for TFTP's 3842 UDP source port. 3843 3844 tftpdstp - If this is set, the value is used for TFTP's UDP 3845 destination port instead of the Well Know Port 69. 3846 3847 tftpblocksize - Block size to use for TFTP transfers; if not set, 3848 we use the TFTP server's default block size 3849 3850 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3851 seconds, minimum value is 1000 = 1 second). Defines 3852 when a packet is considered to be lost so it has to 3853 be retransmitted. The default is 5000 = 5 seconds. 3854 Lowering this value may make downloads succeed 3855 faster in networks with high packet loss rates or 3856 with unreliable TFTP servers. 3857 3858 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3859 unit, minimum value = 0). Defines how many timeouts 3860 can happen during a single file transfer before that 3861 transfer is aborted. The default is 10, and 0 means 3862 'no timeouts allowed'. Increasing this value may help 3863 downloads succeed with high packet loss rates, or with 3864 unreliable TFTP servers or client hardware. 3865 3866 vlan - When set to a value < 4095 the traffic over 3867 Ethernet is encapsulated/received over 802.1q 3868 VLAN tagged frames. 3869 3870 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3871 Unsigned value, in milliseconds. If not set, the period will 3872 be either the default (28000), or a value based on 3873 CONFIG_NET_RETRY_COUNT, if defined. This value has 3874 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3875 3876The following image location variables contain the location of images 3877used in booting. The "Image" column gives the role of the image and is 3878not an environment variable name. The other columns are environment 3879variable names. "File Name" gives the name of the file on a TFTP 3880server, "RAM Address" gives the location in RAM the image will be 3881loaded to, and "Flash Location" gives the image's address in NOR 3882flash or offset in NAND flash. 3883 3884*Note* - these variables don't have to be defined for all boards, some 3885boards currently use other variables for these purposes, and some 3886boards use these variables for other purposes. 3887 3888Image File Name RAM Address Flash Location 3889----- --------- ----------- -------------- 3890u-boot u-boot u-boot_addr_r u-boot_addr 3891Linux kernel bootfile kernel_addr_r kernel_addr 3892device tree blob fdtfile fdt_addr_r fdt_addr 3893ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3894 3895The following environment variables may be used and automatically 3896updated by the network boot commands ("bootp" and "rarpboot"), 3897depending the information provided by your boot server: 3898 3899 bootfile - see above 3900 dnsip - IP address of your Domain Name Server 3901 dnsip2 - IP address of your secondary Domain Name Server 3902 gatewayip - IP address of the Gateway (Router) to use 3903 hostname - Target hostname 3904 ipaddr - see above 3905 netmask - Subnet Mask 3906 rootpath - Pathname of the root filesystem on the NFS server 3907 serverip - see above 3908 3909 3910There are two special Environment Variables: 3911 3912 serial# - contains hardware identification information such 3913 as type string and/or serial number 3914 ethaddr - Ethernet address 3915 3916These variables can be set only once (usually during manufacturing of 3917the board). U-Boot refuses to delete or overwrite these variables 3918once they have been set once. 3919 3920 3921Further special Environment Variables: 3922 3923 ver - Contains the U-Boot version string as printed 3924 with the "version" command. This variable is 3925 readonly (see CONFIG_VERSION_VARIABLE). 3926 3927 3928Please note that changes to some configuration parameters may take 3929only effect after the next boot (yes, that's just like Windoze :-). 3930 3931 3932Callback functions for environment variables: 3933--------------------------------------------- 3934 3935For some environment variables, the behavior of u-boot needs to change 3936when their values are changed. This functionality allows functions to 3937be associated with arbitrary variables. On creation, overwrite, or 3938deletion, the callback will provide the opportunity for some side 3939effect to happen or for the change to be rejected. 3940 3941The callbacks are named and associated with a function using the 3942U_BOOT_ENV_CALLBACK macro in your board or driver code. 3943 3944These callbacks are associated with variables in one of two ways. The 3945static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3946in the board configuration to a string that defines a list of 3947associations. The list must be in the following format: 3948 3949 entry = variable_name[:callback_name] 3950 list = entry[,list] 3951 3952If the callback name is not specified, then the callback is deleted. 3953Spaces are also allowed anywhere in the list. 3954 3955Callbacks can also be associated by defining the ".callbacks" variable 3956with the same list format above. Any association in ".callbacks" will 3957override any association in the static list. You can define 3958CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 3959".callbacks" environment variable in the default or embedded environment. 3960 3961If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3962regular expression. This allows multiple variables to be connected to 3963the same callback without explicitly listing them all out. 3964 3965 3966Command Line Parsing: 3967===================== 3968 3969There are two different command line parsers available with U-Boot: 3970the old "simple" one, and the much more powerful "hush" shell: 3971 3972Old, simple command line parser: 3973-------------------------------- 3974 3975- supports environment variables (through setenv / saveenv commands) 3976- several commands on one line, separated by ';' 3977- variable substitution using "... ${name} ..." syntax 3978- special characters ('$', ';') can be escaped by prefixing with '\', 3979 for example: 3980 setenv bootcmd bootm \${address} 3981- You can also escape text by enclosing in single apostrophes, for example: 3982 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 3983 3984Hush shell: 3985----------- 3986 3987- similar to Bourne shell, with control structures like 3988 if...then...else...fi, for...do...done; while...do...done, 3989 until...do...done, ... 3990- supports environment ("global") variables (through setenv / saveenv 3991 commands) and local shell variables (through standard shell syntax 3992 "name=value"); only environment variables can be used with "run" 3993 command 3994 3995General rules: 3996-------------- 3997 3998(1) If a command line (or an environment variable executed by a "run" 3999 command) contains several commands separated by semicolon, and 4000 one of these commands fails, then the remaining commands will be 4001 executed anyway. 4002 4003(2) If you execute several variables with one call to run (i. e. 4004 calling run with a list of variables as arguments), any failing 4005 command will cause "run" to terminate, i. e. the remaining 4006 variables are not executed. 4007 4008Note for Redundant Ethernet Interfaces: 4009======================================= 4010 4011Some boards come with redundant Ethernet interfaces; U-Boot supports 4012such configurations and is capable of automatic selection of a 4013"working" interface when needed. MAC assignment works as follows: 4014 4015Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4016MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4017"eth1addr" (=>eth1), "eth2addr", ... 4018 4019If the network interface stores some valid MAC address (for instance 4020in SROM), this is used as default address if there is NO correspon- 4021ding setting in the environment; if the corresponding environment 4022variable is set, this overrides the settings in the card; that means: 4023 4024o If the SROM has a valid MAC address, and there is no address in the 4025 environment, the SROM's address is used. 4026 4027o If there is no valid address in the SROM, and a definition in the 4028 environment exists, then the value from the environment variable is 4029 used. 4030 4031o If both the SROM and the environment contain a MAC address, and 4032 both addresses are the same, this MAC address is used. 4033 4034o If both the SROM and the environment contain a MAC address, and the 4035 addresses differ, the value from the environment is used and a 4036 warning is printed. 4037 4038o If neither SROM nor the environment contain a MAC address, an error 4039 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4040 a random, locally-assigned MAC is used. 4041 4042If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4043will be programmed into hardware as part of the initialization process. This 4044may be skipped by setting the appropriate 'ethmacskip' environment variable. 4045The naming convention is as follows: 4046"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4047 4048Image Formats: 4049============== 4050 4051U-Boot is capable of booting (and performing other auxiliary operations on) 4052images in two formats: 4053 4054New uImage format (FIT) 4055----------------------- 4056 4057Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4058to Flattened Device Tree). It allows the use of images with multiple 4059components (several kernels, ramdisks, etc.), with contents protected by 4060SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4061 4062 4063Old uImage format 4064----------------- 4065 4066Old image format is based on binary files which can be basically anything, 4067preceded by a special header; see the definitions in include/image.h for 4068details; basically, the header defines the following image properties: 4069 4070* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4071 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4072 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4073 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4074 INTEGRITY). 4075* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4076 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4077 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4078* Compression Type (uncompressed, gzip, bzip2) 4079* Load Address 4080* Entry Point 4081* Image Name 4082* Image Timestamp 4083 4084The header is marked by a special Magic Number, and both the header 4085and the data portions of the image are secured against corruption by 4086CRC32 checksums. 4087 4088 4089Linux Support: 4090============== 4091 4092Although U-Boot should support any OS or standalone application 4093easily, the main focus has always been on Linux during the design of 4094U-Boot. 4095 4096U-Boot includes many features that so far have been part of some 4097special "boot loader" code within the Linux kernel. Also, any 4098"initrd" images to be used are no longer part of one big Linux image; 4099instead, kernel and "initrd" are separate images. This implementation 4100serves several purposes: 4101 4102- the same features can be used for other OS or standalone 4103 applications (for instance: using compressed images to reduce the 4104 Flash memory footprint) 4105 4106- it becomes much easier to port new Linux kernel versions because 4107 lots of low-level, hardware dependent stuff are done by U-Boot 4108 4109- the same Linux kernel image can now be used with different "initrd" 4110 images; of course this also means that different kernel images can 4111 be run with the same "initrd". This makes testing easier (you don't 4112 have to build a new "zImage.initrd" Linux image when you just 4113 change a file in your "initrd"). Also, a field-upgrade of the 4114 software is easier now. 4115 4116 4117Linux HOWTO: 4118============ 4119 4120Porting Linux to U-Boot based systems: 4121--------------------------------------- 4122 4123U-Boot cannot save you from doing all the necessary modifications to 4124configure the Linux device drivers for use with your target hardware 4125(no, we don't intend to provide a full virtual machine interface to 4126Linux :-). 4127 4128But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4129 4130Just make sure your machine specific header file (for instance 4131include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4132Information structure as we define in include/asm-<arch>/u-boot.h, 4133and make sure that your definition of IMAP_ADDR uses the same value 4134as your U-Boot configuration in CONFIG_SYS_IMMR. 4135 4136Note that U-Boot now has a driver model, a unified model for drivers. 4137If you are adding a new driver, plumb it into driver model. If there 4138is no uclass available, you are encouraged to create one. See 4139doc/driver-model. 4140 4141 4142Configuring the Linux kernel: 4143----------------------------- 4144 4145No specific requirements for U-Boot. Make sure you have some root 4146device (initial ramdisk, NFS) for your target system. 4147 4148 4149Building a Linux Image: 4150----------------------- 4151 4152With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4153not used. If you use recent kernel source, a new build target 4154"uImage" will exist which automatically builds an image usable by 4155U-Boot. Most older kernels also have support for a "pImage" target, 4156which was introduced for our predecessor project PPCBoot and uses a 4157100% compatible format. 4158 4159Example: 4160 4161 make TQM850L_defconfig 4162 make oldconfig 4163 make dep 4164 make uImage 4165 4166The "uImage" build target uses a special tool (in 'tools/mkimage') to 4167encapsulate a compressed Linux kernel image with header information, 4168CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4169 4170* build a standard "vmlinux" kernel image (in ELF binary format): 4171 4172* convert the kernel into a raw binary image: 4173 4174 ${CROSS_COMPILE}-objcopy -O binary \ 4175 -R .note -R .comment \ 4176 -S vmlinux linux.bin 4177 4178* compress the binary image: 4179 4180 gzip -9 linux.bin 4181 4182* package compressed binary image for U-Boot: 4183 4184 mkimage -A ppc -O linux -T kernel -C gzip \ 4185 -a 0 -e 0 -n "Linux Kernel Image" \ 4186 -d linux.bin.gz uImage 4187 4188 4189The "mkimage" tool can also be used to create ramdisk images for use 4190with U-Boot, either separated from the Linux kernel image, or 4191combined into one file. "mkimage" encapsulates the images with a 64 4192byte header containing information about target architecture, 4193operating system, image type, compression method, entry points, time 4194stamp, CRC32 checksums, etc. 4195 4196"mkimage" can be called in two ways: to verify existing images and 4197print the header information, or to build new images. 4198 4199In the first form (with "-l" option) mkimage lists the information 4200contained in the header of an existing U-Boot image; this includes 4201checksum verification: 4202 4203 tools/mkimage -l image 4204 -l ==> list image header information 4205 4206The second form (with "-d" option) is used to build a U-Boot image 4207from a "data file" which is used as image payload: 4208 4209 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4210 -n name -d data_file image 4211 -A ==> set architecture to 'arch' 4212 -O ==> set operating system to 'os' 4213 -T ==> set image type to 'type' 4214 -C ==> set compression type 'comp' 4215 -a ==> set load address to 'addr' (hex) 4216 -e ==> set entry point to 'ep' (hex) 4217 -n ==> set image name to 'name' 4218 -d ==> use image data from 'datafile' 4219 4220Right now, all Linux kernels for PowerPC systems use the same load 4221address (0x00000000), but the entry point address depends on the 4222kernel version: 4223 4224- 2.2.x kernels have the entry point at 0x0000000C, 4225- 2.3.x and later kernels have the entry point at 0x00000000. 4226 4227So a typical call to build a U-Boot image would read: 4228 4229 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4230 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4231 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4232 > examples/uImage.TQM850L 4233 Image Name: 2.4.4 kernel for TQM850L 4234 Created: Wed Jul 19 02:34:59 2000 4235 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4236 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4237 Load Address: 0x00000000 4238 Entry Point: 0x00000000 4239 4240To verify the contents of the image (or check for corruption): 4241 4242 -> tools/mkimage -l examples/uImage.TQM850L 4243 Image Name: 2.4.4 kernel for TQM850L 4244 Created: Wed Jul 19 02:34:59 2000 4245 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4246 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4247 Load Address: 0x00000000 4248 Entry Point: 0x00000000 4249 4250NOTE: for embedded systems where boot time is critical you can trade 4251speed for memory and install an UNCOMPRESSED image instead: this 4252needs more space in Flash, but boots much faster since it does not 4253need to be uncompressed: 4254 4255 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4256 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4257 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4258 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4259 > examples/uImage.TQM850L-uncompressed 4260 Image Name: 2.4.4 kernel for TQM850L 4261 Created: Wed Jul 19 02:34:59 2000 4262 Image Type: PowerPC Linux Kernel Image (uncompressed) 4263 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4264 Load Address: 0x00000000 4265 Entry Point: 0x00000000 4266 4267 4268Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4269when your kernel is intended to use an initial ramdisk: 4270 4271 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4272 > -A ppc -O linux -T ramdisk -C gzip \ 4273 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4274 Image Name: Simple Ramdisk Image 4275 Created: Wed Jan 12 14:01:50 2000 4276 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4277 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4278 Load Address: 0x00000000 4279 Entry Point: 0x00000000 4280 4281The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4282option performs the converse operation of the mkimage's second form (the "-d" 4283option). Given an image built by mkimage, the dumpimage extracts a "data file" 4284from the image: 4285 4286 tools/dumpimage -i image -T type -p position data_file 4287 -i ==> extract from the 'image' a specific 'data_file' 4288 -T ==> set image type to 'type' 4289 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4290 4291 4292Installing a Linux Image: 4293------------------------- 4294 4295To downloading a U-Boot image over the serial (console) interface, 4296you must convert the image to S-Record format: 4297 4298 objcopy -I binary -O srec examples/image examples/image.srec 4299 4300The 'objcopy' does not understand the information in the U-Boot 4301image header, so the resulting S-Record file will be relative to 4302address 0x00000000. To load it to a given address, you need to 4303specify the target address as 'offset' parameter with the 'loads' 4304command. 4305 4306Example: install the image to address 0x40100000 (which on the 4307TQM8xxL is in the first Flash bank): 4308 4309 => erase 40100000 401FFFFF 4310 4311 .......... done 4312 Erased 8 sectors 4313 4314 => loads 40100000 4315 ## Ready for S-Record download ... 4316 ~>examples/image.srec 4317 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4318 ... 4319 15989 15990 15991 15992 4320 [file transfer complete] 4321 [connected] 4322 ## Start Addr = 0x00000000 4323 4324 4325You can check the success of the download using the 'iminfo' command; 4326this includes a checksum verification so you can be sure no data 4327corruption happened: 4328 4329 => imi 40100000 4330 4331 ## Checking Image at 40100000 ... 4332 Image Name: 2.2.13 for initrd on TQM850L 4333 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4334 Data Size: 335725 Bytes = 327 kB = 0 MB 4335 Load Address: 00000000 4336 Entry Point: 0000000c 4337 Verifying Checksum ... OK 4338 4339 4340Boot Linux: 4341----------- 4342 4343The "bootm" command is used to boot an application that is stored in 4344memory (RAM or Flash). In case of a Linux kernel image, the contents 4345of the "bootargs" environment variable is passed to the kernel as 4346parameters. You can check and modify this variable using the 4347"printenv" and "setenv" commands: 4348 4349 4350 => printenv bootargs 4351 bootargs=root=/dev/ram 4352 4353 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4354 4355 => printenv bootargs 4356 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4357 4358 => bootm 40020000 4359 ## Booting Linux kernel at 40020000 ... 4360 Image Name: 2.2.13 for NFS on TQM850L 4361 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4362 Data Size: 381681 Bytes = 372 kB = 0 MB 4363 Load Address: 00000000 4364 Entry Point: 0000000c 4365 Verifying Checksum ... OK 4366 Uncompressing Kernel Image ... OK 4367 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 4368 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4369 time_init: decrementer frequency = 187500000/60 4370 Calibrating delay loop... 49.77 BogoMIPS 4371 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4372 ... 4373 4374If you want to boot a Linux kernel with initial RAM disk, you pass 4375the memory addresses of both the kernel and the initrd image (PPBCOOT 4376format!) to the "bootm" command: 4377 4378 => imi 40100000 40200000 4379 4380 ## Checking Image at 40100000 ... 4381 Image Name: 2.2.13 for initrd on TQM850L 4382 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4383 Data Size: 335725 Bytes = 327 kB = 0 MB 4384 Load Address: 00000000 4385 Entry Point: 0000000c 4386 Verifying Checksum ... OK 4387 4388 ## Checking Image at 40200000 ... 4389 Image Name: Simple Ramdisk Image 4390 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4391 Data Size: 566530 Bytes = 553 kB = 0 MB 4392 Load Address: 00000000 4393 Entry Point: 00000000 4394 Verifying Checksum ... OK 4395 4396 => bootm 40100000 40200000 4397 ## Booting Linux kernel at 40100000 ... 4398 Image Name: 2.2.13 for initrd on TQM850L 4399 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4400 Data Size: 335725 Bytes = 327 kB = 0 MB 4401 Load Address: 00000000 4402 Entry Point: 0000000c 4403 Verifying Checksum ... OK 4404 Uncompressing Kernel Image ... OK 4405 ## Loading RAMDisk Image at 40200000 ... 4406 Image Name: Simple Ramdisk Image 4407 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4408 Data Size: 566530 Bytes = 553 kB = 0 MB 4409 Load Address: 00000000 4410 Entry Point: 00000000 4411 Verifying Checksum ... OK 4412 Loading Ramdisk ... OK 4413 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 4414 Boot arguments: root=/dev/ram 4415 time_init: decrementer frequency = 187500000/60 4416 Calibrating delay loop... 49.77 BogoMIPS 4417 ... 4418 RAMDISK: Compressed image found at block 0 4419 VFS: Mounted root (ext2 filesystem). 4420 4421 bash# 4422 4423Boot Linux and pass a flat device tree: 4424----------- 4425 4426First, U-Boot must be compiled with the appropriate defines. See the section 4427titled "Linux Kernel Interface" above for a more in depth explanation. The 4428following is an example of how to start a kernel and pass an updated 4429flat device tree: 4430 4431=> print oftaddr 4432oftaddr=0x300000 4433=> print oft 4434oft=oftrees/mpc8540ads.dtb 4435=> tftp $oftaddr $oft 4436Speed: 1000, full duplex 4437Using TSEC0 device 4438TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4439Filename 'oftrees/mpc8540ads.dtb'. 4440Load address: 0x300000 4441Loading: # 4442done 4443Bytes transferred = 4106 (100a hex) 4444=> tftp $loadaddr $bootfile 4445Speed: 1000, full duplex 4446Using TSEC0 device 4447TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4448Filename 'uImage'. 4449Load address: 0x200000 4450Loading:############ 4451done 4452Bytes transferred = 1029407 (fb51f hex) 4453=> print loadaddr 4454loadaddr=200000 4455=> print oftaddr 4456oftaddr=0x300000 4457=> bootm $loadaddr - $oftaddr 4458## Booting image at 00200000 ... 4459 Image Name: Linux-2.6.17-dirty 4460 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4461 Data Size: 1029343 Bytes = 1005.2 kB 4462 Load Address: 00000000 4463 Entry Point: 00000000 4464 Verifying Checksum ... OK 4465 Uncompressing Kernel Image ... OK 4466Booting using flat device tree at 0x300000 4467Using MPC85xx ADS machine description 4468Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4469[snip] 4470 4471 4472More About U-Boot Image Types: 4473------------------------------ 4474 4475U-Boot supports the following image types: 4476 4477 "Standalone Programs" are directly runnable in the environment 4478 provided by U-Boot; it is expected that (if they behave 4479 well) you can continue to work in U-Boot after return from 4480 the Standalone Program. 4481 "OS Kernel Images" are usually images of some Embedded OS which 4482 will take over control completely. Usually these programs 4483 will install their own set of exception handlers, device 4484 drivers, set up the MMU, etc. - this means, that you cannot 4485 expect to re-enter U-Boot except by resetting the CPU. 4486 "RAMDisk Images" are more or less just data blocks, and their 4487 parameters (address, size) are passed to an OS kernel that is 4488 being started. 4489 "Multi-File Images" contain several images, typically an OS 4490 (Linux) kernel image and one or more data images like 4491 RAMDisks. This construct is useful for instance when you want 4492 to boot over the network using BOOTP etc., where the boot 4493 server provides just a single image file, but you want to get 4494 for instance an OS kernel and a RAMDisk image. 4495 4496 "Multi-File Images" start with a list of image sizes, each 4497 image size (in bytes) specified by an "uint32_t" in network 4498 byte order. This list is terminated by an "(uint32_t)0". 4499 Immediately after the terminating 0 follow the images, one by 4500 one, all aligned on "uint32_t" boundaries (size rounded up to 4501 a multiple of 4 bytes). 4502 4503 "Firmware Images" are binary images containing firmware (like 4504 U-Boot or FPGA images) which usually will be programmed to 4505 flash memory. 4506 4507 "Script files" are command sequences that will be executed by 4508 U-Boot's command interpreter; this feature is especially 4509 useful when you configure U-Boot to use a real shell (hush) 4510 as command interpreter. 4511 4512Booting the Linux zImage: 4513------------------------- 4514 4515On some platforms, it's possible to boot Linux zImage. This is done 4516using the "bootz" command. The syntax of "bootz" command is the same 4517as the syntax of "bootm" command. 4518 4519Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4520kernel with raw initrd images. The syntax is slightly different, the 4521address of the initrd must be augmented by it's size, in the following 4522format: "<initrd addres>:<initrd size>". 4523 4524 4525Standalone HOWTO: 4526================= 4527 4528One of the features of U-Boot is that you can dynamically load and 4529run "standalone" applications, which can use some resources of 4530U-Boot like console I/O functions or interrupt services. 4531 4532Two simple examples are included with the sources: 4533 4534"Hello World" Demo: 4535------------------- 4536 4537'examples/hello_world.c' contains a small "Hello World" Demo 4538application; it is automatically compiled when you build U-Boot. 4539It's configured to run at address 0x00040004, so you can play with it 4540like that: 4541 4542 => loads 4543 ## Ready for S-Record download ... 4544 ~>examples/hello_world.srec 4545 1 2 3 4 5 6 7 8 9 10 11 ... 4546 [file transfer complete] 4547 [connected] 4548 ## Start Addr = 0x00040004 4549 4550 => go 40004 Hello World! This is a test. 4551 ## Starting application at 0x00040004 ... 4552 Hello World 4553 argc = 7 4554 argv[0] = "40004" 4555 argv[1] = "Hello" 4556 argv[2] = "World!" 4557 argv[3] = "This" 4558 argv[4] = "is" 4559 argv[5] = "a" 4560 argv[6] = "test." 4561 argv[7] = "<NULL>" 4562 Hit any key to exit ... 4563 4564 ## Application terminated, rc = 0x0 4565 4566Another example, which demonstrates how to register a CPM interrupt 4567handler with the U-Boot code, can be found in 'examples/timer.c'. 4568Here, a CPM timer is set up to generate an interrupt every second. 4569The interrupt service routine is trivial, just printing a '.' 4570character, but this is just a demo program. The application can be 4571controlled by the following keys: 4572 4573 ? - print current values og the CPM Timer registers 4574 b - enable interrupts and start timer 4575 e - stop timer and disable interrupts 4576 q - quit application 4577 4578 => loads 4579 ## Ready for S-Record download ... 4580 ~>examples/timer.srec 4581 1 2 3 4 5 6 7 8 9 10 11 ... 4582 [file transfer complete] 4583 [connected] 4584 ## Start Addr = 0x00040004 4585 4586 => go 40004 4587 ## Starting application at 0x00040004 ... 4588 TIMERS=0xfff00980 4589 Using timer 1 4590 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4591 4592Hit 'b': 4593 [q, b, e, ?] Set interval 1000000 us 4594 Enabling timer 4595Hit '?': 4596 [q, b, e, ?] ........ 4597 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4598Hit '?': 4599 [q, b, e, ?] . 4600 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4601Hit '?': 4602 [q, b, e, ?] . 4603 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4604Hit '?': 4605 [q, b, e, ?] . 4606 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4607Hit 'e': 4608 [q, b, e, ?] ...Stopping timer 4609Hit 'q': 4610 [q, b, e, ?] ## Application terminated, rc = 0x0 4611 4612 4613Minicom warning: 4614================ 4615 4616Over time, many people have reported problems when trying to use the 4617"minicom" terminal emulation program for serial download. I (wd) 4618consider minicom to be broken, and recommend not to use it. Under 4619Unix, I recommend to use C-Kermit for general purpose use (and 4620especially for kermit binary protocol download ("loadb" command), and 4621use "cu" for S-Record download ("loads" command). See 4622http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4623for help with kermit. 4624 4625 4626Nevertheless, if you absolutely want to use it try adding this 4627configuration to your "File transfer protocols" section: 4628 4629 Name Program Name U/D FullScr IO-Red. Multi 4630 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4631 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4632 4633 4634NetBSD Notes: 4635============= 4636 4637Starting at version 0.9.2, U-Boot supports NetBSD both as host 4638(build U-Boot) and target system (boots NetBSD/mpc8xx). 4639 4640Building requires a cross environment; it is known to work on 4641NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4642need gmake since the Makefiles are not compatible with BSD make). 4643Note that the cross-powerpc package does not install include files; 4644attempting to build U-Boot will fail because <machine/ansi.h> is 4645missing. This file has to be installed and patched manually: 4646 4647 # cd /usr/pkg/cross/powerpc-netbsd/include 4648 # mkdir powerpc 4649 # ln -s powerpc machine 4650 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4651 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4652 4653Native builds *don't* work due to incompatibilities between native 4654and U-Boot include files. 4655 4656Booting assumes that (the first part of) the image booted is a 4657stage-2 loader which in turn loads and then invokes the kernel 4658proper. Loader sources will eventually appear in the NetBSD source 4659tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4660meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4661 4662 4663Implementation Internals: 4664========================= 4665 4666The following is not intended to be a complete description of every 4667implementation detail. However, it should help to understand the 4668inner workings of U-Boot and make it easier to port it to custom 4669hardware. 4670 4671 4672Initial Stack, Global Data: 4673--------------------------- 4674 4675The implementation of U-Boot is complicated by the fact that U-Boot 4676starts running out of ROM (flash memory), usually without access to 4677system RAM (because the memory controller is not initialized yet). 4678This means that we don't have writable Data or BSS segments, and BSS 4679is not initialized as zero. To be able to get a C environment working 4680at all, we have to allocate at least a minimal stack. Implementation 4681options for this are defined and restricted by the CPU used: Some CPU 4682models provide on-chip memory (like the IMMR area on MPC8xx and 4683MPC826x processors), on others (parts of) the data cache can be 4684locked as (mis-) used as memory, etc. 4685 4686 Chris Hallinan posted a good summary of these issues to the 4687 U-Boot mailing list: 4688 4689 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4690 From: "Chris Hallinan" <clh@net1plus.com> 4691 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4692 ... 4693 4694 Correct me if I'm wrong, folks, but the way I understand it 4695 is this: Using DCACHE as initial RAM for Stack, etc, does not 4696 require any physical RAM backing up the cache. The cleverness 4697 is that the cache is being used as a temporary supply of 4698 necessary storage before the SDRAM controller is setup. It's 4699 beyond the scope of this list to explain the details, but you 4700 can see how this works by studying the cache architecture and 4701 operation in the architecture and processor-specific manuals. 4702 4703 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4704 is another option for the system designer to use as an 4705 initial stack/RAM area prior to SDRAM being available. Either 4706 option should work for you. Using CS 4 should be fine if your 4707 board designers haven't used it for something that would 4708 cause you grief during the initial boot! It is frequently not 4709 used. 4710 4711 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4712 with your processor/board/system design. The default value 4713 you will find in any recent u-boot distribution in 4714 walnut.h should work for you. I'd set it to a value larger 4715 than your SDRAM module. If you have a 64MB SDRAM module, set 4716 it above 400_0000. Just make sure your board has no resources 4717 that are supposed to respond to that address! That code in 4718 start.S has been around a while and should work as is when 4719 you get the config right. 4720 4721 -Chris Hallinan 4722 DS4.COM, Inc. 4723 4724It is essential to remember this, since it has some impact on the C 4725code for the initialization procedures: 4726 4727* Initialized global data (data segment) is read-only. Do not attempt 4728 to write it. 4729 4730* Do not use any uninitialized global data (or implicitly initialized 4731 as zero data - BSS segment) at all - this is undefined, initiali- 4732 zation is performed later (when relocating to RAM). 4733 4734* Stack space is very limited. Avoid big data buffers or things like 4735 that. 4736 4737Having only the stack as writable memory limits means we cannot use 4738normal global data to share information between the code. But it 4739turned out that the implementation of U-Boot can be greatly 4740simplified by making a global data structure (gd_t) available to all 4741functions. We could pass a pointer to this data as argument to _all_ 4742functions, but this would bloat the code. Instead we use a feature of 4743the GCC compiler (Global Register Variables) to share the data: we 4744place a pointer (gd) to the global data into a register which we 4745reserve for this purpose. 4746 4747When choosing a register for such a purpose we are restricted by the 4748relevant (E)ABI specifications for the current architecture, and by 4749GCC's implementation. 4750 4751For PowerPC, the following registers have specific use: 4752 R1: stack pointer 4753 R2: reserved for system use 4754 R3-R4: parameter passing and return values 4755 R5-R10: parameter passing 4756 R13: small data area pointer 4757 R30: GOT pointer 4758 R31: frame pointer 4759 4760 (U-Boot also uses R12 as internal GOT pointer. r12 4761 is a volatile register so r12 needs to be reset when 4762 going back and forth between asm and C) 4763 4764 ==> U-Boot will use R2 to hold a pointer to the global data 4765 4766 Note: on PPC, we could use a static initializer (since the 4767 address of the global data structure is known at compile time), 4768 but it turned out that reserving a register results in somewhat 4769 smaller code - although the code savings are not that big (on 4770 average for all boards 752 bytes for the whole U-Boot image, 4771 624 text + 127 data). 4772 4773On ARM, the following registers are used: 4774 4775 R0: function argument word/integer result 4776 R1-R3: function argument word 4777 R9: platform specific 4778 R10: stack limit (used only if stack checking is enabled) 4779 R11: argument (frame) pointer 4780 R12: temporary workspace 4781 R13: stack pointer 4782 R14: link register 4783 R15: program counter 4784 4785 ==> U-Boot will use R9 to hold a pointer to the global data 4786 4787 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4788 4789On Nios II, the ABI is documented here: 4790 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4791 4792 ==> U-Boot will use gp to hold a pointer to the global data 4793 4794 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4795 to access small data sections, so gp is free. 4796 4797On NDS32, the following registers are used: 4798 4799 R0-R1: argument/return 4800 R2-R5: argument 4801 R15: temporary register for assembler 4802 R16: trampoline register 4803 R28: frame pointer (FP) 4804 R29: global pointer (GP) 4805 R30: link register (LP) 4806 R31: stack pointer (SP) 4807 PC: program counter (PC) 4808 4809 ==> U-Boot will use R10 to hold a pointer to the global data 4810 4811NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4812or current versions of GCC may "optimize" the code too much. 4813 4814On RISC-V, the following registers are used: 4815 4816 x0: hard-wired zero (zero) 4817 x1: return address (ra) 4818 x2: stack pointer (sp) 4819 x3: global pointer (gp) 4820 x4: thread pointer (tp) 4821 x5: link register (t0) 4822 x8: frame pointer (fp) 4823 x10-x11: arguments/return values (a0-1) 4824 x12-x17: arguments (a2-7) 4825 x28-31: temporaries (t3-6) 4826 pc: program counter (pc) 4827 4828 ==> U-Boot will use gp to hold a pointer to the global data 4829 4830Memory Management: 4831------------------ 4832 4833U-Boot runs in system state and uses physical addresses, i.e. the 4834MMU is not used either for address mapping nor for memory protection. 4835 4836The available memory is mapped to fixed addresses using the memory 4837controller. In this process, a contiguous block is formed for each 4838memory type (Flash, SDRAM, SRAM), even when it consists of several 4839physical memory banks. 4840 4841U-Boot is installed in the first 128 kB of the first Flash bank (on 4842TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4843booting and sizing and initializing DRAM, the code relocates itself 4844to the upper end of DRAM. Immediately below the U-Boot code some 4845memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4846configuration setting]. Below that, a structure with global Board 4847Info data is placed, followed by the stack (growing downward). 4848 4849Additionally, some exception handler code is copied to the low 8 kB 4850of DRAM (0x00000000 ... 0x00001FFF). 4851 4852So a typical memory configuration with 16 MB of DRAM could look like 4853this: 4854 4855 0x0000 0000 Exception Vector code 4856 : 4857 0x0000 1FFF 4858 0x0000 2000 Free for Application Use 4859 : 4860 : 4861 4862 : 4863 : 4864 0x00FB FF20 Monitor Stack (Growing downward) 4865 0x00FB FFAC Board Info Data and permanent copy of global data 4866 0x00FC 0000 Malloc Arena 4867 : 4868 0x00FD FFFF 4869 0x00FE 0000 RAM Copy of Monitor Code 4870 ... eventually: LCD or video framebuffer 4871 ... eventually: pRAM (Protected RAM - unchanged by reset) 4872 0x00FF FFFF [End of RAM] 4873 4874 4875System Initialization: 4876---------------------- 4877 4878In the reset configuration, U-Boot starts at the reset entry point 4879(on most PowerPC systems at address 0x00000100). Because of the reset 4880configuration for CS0# this is a mirror of the on board Flash memory. 4881To be able to re-map memory U-Boot then jumps to its link address. 4882To be able to implement the initialization code in C, a (small!) 4883initial stack is set up in the internal Dual Ported RAM (in case CPUs 4884which provide such a feature like), or in a locked part of the data 4885cache. After that, U-Boot initializes the CPU core, the caches and 4886the SIU. 4887 4888Next, all (potentially) available memory banks are mapped using a 4889preliminary mapping. For example, we put them on 512 MB boundaries 4890(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4891on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4892programmed for SDRAM access. Using the temporary configuration, a 4893simple memory test is run that determines the size of the SDRAM 4894banks. 4895 4896When there is more than one SDRAM bank, and the banks are of 4897different size, the largest is mapped first. For equal size, the first 4898bank (CS2#) is mapped first. The first mapping is always for address 48990x00000000, with any additional banks following immediately to create 4900contiguous memory starting from 0. 4901 4902Then, the monitor installs itself at the upper end of the SDRAM area 4903and allocates memory for use by malloc() and for the global Board 4904Info data; also, the exception vector code is copied to the low RAM 4905pages, and the final stack is set up. 4906 4907Only after this relocation will you have a "normal" C environment; 4908until that you are restricted in several ways, mostly because you are 4909running from ROM, and because the code will have to be relocated to a 4910new address in RAM. 4911 4912 4913U-Boot Porting Guide: 4914---------------------- 4915 4916[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4917list, October 2002] 4918 4919 4920int main(int argc, char *argv[]) 4921{ 4922 sighandler_t no_more_time; 4923 4924 signal(SIGALRM, no_more_time); 4925 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4926 4927 if (available_money > available_manpower) { 4928 Pay consultant to port U-Boot; 4929 return 0; 4930 } 4931 4932 Download latest U-Boot source; 4933 4934 Subscribe to u-boot mailing list; 4935 4936 if (clueless) 4937 email("Hi, I am new to U-Boot, how do I get started?"); 4938 4939 while (learning) { 4940 Read the README file in the top level directory; 4941 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4942 Read applicable doc/*.README; 4943 Read the source, Luke; 4944 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4945 } 4946 4947 if (available_money > toLocalCurrency ($2500)) 4948 Buy a BDI3000; 4949 else 4950 Add a lot of aggravation and time; 4951 4952 if (a similar board exists) { /* hopefully... */ 4953 cp -a board/<similar> board/<myboard> 4954 cp include/configs/<similar>.h include/configs/<myboard>.h 4955 } else { 4956 Create your own board support subdirectory; 4957 Create your own board include/configs/<myboard>.h file; 4958 } 4959 Edit new board/<myboard> files 4960 Edit new include/configs/<myboard>.h 4961 4962 while (!accepted) { 4963 while (!running) { 4964 do { 4965 Add / modify source code; 4966 } until (compiles); 4967 Debug; 4968 if (clueless) 4969 email("Hi, I am having problems..."); 4970 } 4971 Send patch file to the U-Boot email list; 4972 if (reasonable critiques) 4973 Incorporate improvements from email list code review; 4974 else 4975 Defend code as written; 4976 } 4977 4978 return 0; 4979} 4980 4981void no_more_time (int sig) 4982{ 4983 hire_a_guru(); 4984} 4985 4986 4987Coding Standards: 4988----------------- 4989 4990All contributions to U-Boot should conform to the Linux kernel 4991coding style; see the kernel coding style guide at 4992https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 4993script "scripts/Lindent" in your Linux kernel source directory. 4994 4995Source files originating from a different project (for example the 4996MTD subsystem) are generally exempt from these guidelines and are not 4997reformatted to ease subsequent migration to newer versions of those 4998sources. 4999 5000Please note that U-Boot is implemented in C (and to some small parts in 5001Assembler); no C++ is used, so please do not use C++ style comments (//) 5002in your code. 5003 5004Please also stick to the following formatting rules: 5005- remove any trailing white space 5006- use TAB characters for indentation and vertical alignment, not spaces 5007- make sure NOT to use DOS '\r\n' line feeds 5008- do not add more than 2 consecutive empty lines to source files 5009- do not add trailing empty lines to source files 5010 5011Submissions which do not conform to the standards may be returned 5012with a request to reformat the changes. 5013 5014 5015Submitting Patches: 5016------------------- 5017 5018Since the number of patches for U-Boot is growing, we need to 5019establish some rules. Submissions which do not conform to these rules 5020may be rejected, even when they contain important and valuable stuff. 5021 5022Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5023 5024Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5025see https://lists.denx.de/listinfo/u-boot 5026 5027When you send a patch, please include the following information with 5028it: 5029 5030* For bug fixes: a description of the bug and how your patch fixes 5031 this bug. Please try to include a way of demonstrating that the 5032 patch actually fixes something. 5033 5034* For new features: a description of the feature and your 5035 implementation. 5036 5037* A CHANGELOG entry as plaintext (separate from the patch) 5038 5039* For major contributions, add a MAINTAINERS file with your 5040 information and associated file and directory references. 5041 5042* When you add support for a new board, don't forget to add a 5043 maintainer e-mail address to the boards.cfg file, too. 5044 5045* If your patch adds new configuration options, don't forget to 5046 document these in the README file. 5047 5048* The patch itself. If you are using git (which is *strongly* 5049 recommended) you can easily generate the patch using the 5050 "git format-patch". If you then use "git send-email" to send it to 5051 the U-Boot mailing list, you will avoid most of the common problems 5052 with some other mail clients. 5053 5054 If you cannot use git, use "diff -purN OLD NEW". If your version of 5055 diff does not support these options, then get the latest version of 5056 GNU diff. 5057 5058 The current directory when running this command shall be the parent 5059 directory of the U-Boot source tree (i. e. please make sure that 5060 your patch includes sufficient directory information for the 5061 affected files). 5062 5063 We prefer patches as plain text. MIME attachments are discouraged, 5064 and compressed attachments must not be used. 5065 5066* If one logical set of modifications affects or creates several 5067 files, all these changes shall be submitted in a SINGLE patch file. 5068 5069* Changesets that contain different, unrelated modifications shall be 5070 submitted as SEPARATE patches, one patch per changeset. 5071 5072 5073Notes: 5074 5075* Before sending the patch, run the buildman script on your patched 5076 source tree and make sure that no errors or warnings are reported 5077 for any of the boards. 5078 5079* Keep your modifications to the necessary minimum: A patch 5080 containing several unrelated changes or arbitrary reformats will be 5081 returned with a request to re-formatting / split it. 5082 5083* If you modify existing code, make sure that your new code does not 5084 add to the memory footprint of the code ;-) Small is beautiful! 5085 When adding new features, these should compile conditionally only 5086 (using #ifdef), and the resulting code with the new feature 5087 disabled must not need more memory than the old code without your 5088 modification. 5089 5090* Remember that there is a size limit of 100 kB per message on the 5091 u-boot mailing list. Bigger patches will be moderated. If they are 5092 reasonable and not too big, they will be acknowledged. But patches 5093 bigger than the size limit should be avoided. 5094