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- USB Device Firmware Update (DFU) class support: 1176 CONFIG_DFU_OVER_USB 1177 This enables the USB portion of the DFU USB class 1178 1179 CONFIG_DFU_MMC 1180 This enables support for exposing (e)MMC devices via DFU. 1181 1182 CONFIG_DFU_NAND 1183 This enables support for exposing NAND devices via DFU. 1184 1185 CONFIG_DFU_RAM 1186 This enables support for exposing RAM via DFU. 1187 Note: DFU spec refer to non-volatile memory usage, but 1188 allow usages beyond the scope of spec - here RAM usage, 1189 one that would help mostly the developer. 1190 1191 CONFIG_SYS_DFU_DATA_BUF_SIZE 1192 Dfu transfer uses a buffer before writing data to the 1193 raw storage device. Make the size (in bytes) of this buffer 1194 configurable. The size of this buffer is also configurable 1195 through the "dfu_bufsiz" environment variable. 1196 1197 CONFIG_SYS_DFU_MAX_FILE_SIZE 1198 When updating files rather than the raw storage device, 1199 we use a static buffer to copy the file into and then write 1200 the buffer once we've been given the whole file. Define 1201 this to the maximum filesize (in bytes) for the buffer. 1202 Default is 4 MiB if undefined. 1203 1204 DFU_DEFAULT_POLL_TIMEOUT 1205 Poll timeout [ms], is the timeout a device can send to the 1206 host. The host must wait for this timeout before sending 1207 a subsequent DFU_GET_STATUS request to the device. 1208 1209 DFU_MANIFEST_POLL_TIMEOUT 1210 Poll timeout [ms], which the device sends to the host when 1211 entering dfuMANIFEST state. Host waits this timeout, before 1212 sending again an USB request to the device. 1213 1214- Journaling Flash filesystem support: 1215 CONFIG_JFFS2_NAND 1216 Define these for a default partition on a NAND device 1217 1218 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1219 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1220 Define these for a default partition on a NOR device 1221 1222- Keyboard Support: 1223 See Kconfig help for available keyboard drivers. 1224 1225 CONFIG_KEYBOARD 1226 1227 Define this to enable a custom keyboard support. 1228 This simply calls drv_keyboard_init() which must be 1229 defined in your board-specific files. This option is deprecated 1230 and is only used by novena. For new boards, use driver model 1231 instead. 1232 1233- Video support: 1234 CONFIG_FSL_DIU_FB 1235 Enable the Freescale DIU video driver. Reference boards for 1236 SOCs that have a DIU should define this macro to enable DIU 1237 support, and should also define these other macros: 1238 1239 CONFIG_SYS_DIU_ADDR 1240 CONFIG_VIDEO 1241 CONFIG_CFB_CONSOLE 1242 CONFIG_VIDEO_SW_CURSOR 1243 CONFIG_VGA_AS_SINGLE_DEVICE 1244 CONFIG_VIDEO_LOGO 1245 CONFIG_VIDEO_BMP_LOGO 1246 1247 The DIU driver will look for the 'video-mode' environment 1248 variable, and if defined, enable the DIU as a console during 1249 boot. See the documentation file doc/README.video for a 1250 description of this variable. 1251 1252- LCD Support: CONFIG_LCD 1253 1254 Define this to enable LCD support (for output to LCD 1255 display); also select one of the supported displays 1256 by defining one of these: 1257 1258 CONFIG_ATMEL_LCD: 1259 1260 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1261 1262 CONFIG_NEC_NL6448AC33: 1263 1264 NEC NL6448AC33-18. Active, color, single scan. 1265 1266 CONFIG_NEC_NL6448BC20 1267 1268 NEC NL6448BC20-08. 6.5", 640x480. 1269 Active, color, single scan. 1270 1271 CONFIG_NEC_NL6448BC33_54 1272 1273 NEC NL6448BC33-54. 10.4", 640x480. 1274 Active, color, single scan. 1275 1276 CONFIG_SHARP_16x9 1277 1278 Sharp 320x240. Active, color, single scan. 1279 It isn't 16x9, and I am not sure what it is. 1280 1281 CONFIG_SHARP_LQ64D341 1282 1283 Sharp LQ64D341 display, 640x480. 1284 Active, color, single scan. 1285 1286 CONFIG_HLD1045 1287 1288 HLD1045 display, 640x480. 1289 Active, color, single scan. 1290 1291 CONFIG_OPTREX_BW 1292 1293 Optrex CBL50840-2 NF-FW 99 22 M5 1294 or 1295 Hitachi LMG6912RPFC-00T 1296 or 1297 Hitachi SP14Q002 1298 1299 320x240. Black & white. 1300 1301 CONFIG_LCD_ALIGNMENT 1302 1303 Normally the LCD is page-aligned (typically 4KB). If this is 1304 defined then the LCD will be aligned to this value instead. 1305 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1306 here, since it is cheaper to change data cache settings on 1307 a per-section basis. 1308 1309 1310 CONFIG_LCD_ROTATION 1311 1312 Sometimes, for example if the display is mounted in portrait 1313 mode or even if it's mounted landscape but rotated by 180degree, 1314 we need to rotate our content of the display relative to the 1315 framebuffer, so that user can read the messages which are 1316 printed out. 1317 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1318 initialized with a given rotation from "vl_rot" out of 1319 "vidinfo_t" which is provided by the board specific code. 1320 The value for vl_rot is coded as following (matching to 1321 fbcon=rotate:<n> linux-kernel commandline): 1322 0 = no rotation respectively 0 degree 1323 1 = 90 degree rotation 1324 2 = 180 degree rotation 1325 3 = 270 degree rotation 1326 1327 If CONFIG_LCD_ROTATION is not defined, the console will be 1328 initialized with 0degree rotation. 1329 1330 CONFIG_LCD_BMP_RLE8 1331 1332 Support drawing of RLE8-compressed bitmaps on the LCD. 1333 1334 CONFIG_I2C_EDID 1335 1336 Enables an 'i2c edid' command which can read EDID 1337 information over I2C from an attached LCD display. 1338 1339- Splash Screen Support: CONFIG_SPLASH_SCREEN 1340 1341 If this option is set, the environment is checked for 1342 a variable "splashimage". If found, the usual display 1343 of logo, copyright and system information on the LCD 1344 is suppressed and the BMP image at the address 1345 specified in "splashimage" is loaded instead. The 1346 console is redirected to the "nulldev", too. This 1347 allows for a "silent" boot where a splash screen is 1348 loaded very quickly after power-on. 1349 1350 CONFIG_SPLASHIMAGE_GUARD 1351 1352 If this option is set, then U-Boot will prevent the environment 1353 variable "splashimage" from being set to a problematic address 1354 (see doc/README.displaying-bmps). 1355 This option is useful for targets where, due to alignment 1356 restrictions, an improperly aligned BMP image will cause a data 1357 abort. If you think you will not have problems with unaligned 1358 accesses (for example because your toolchain prevents them) 1359 there is no need to set this option. 1360 1361 CONFIG_SPLASH_SCREEN_ALIGN 1362 1363 If this option is set the splash image can be freely positioned 1364 on the screen. Environment variable "splashpos" specifies the 1365 position as "x,y". If a positive number is given it is used as 1366 number of pixel from left/top. If a negative number is given it 1367 is used as number of pixel from right/bottom. You can also 1368 specify 'm' for centering the image. 1369 1370 Example: 1371 setenv splashpos m,m 1372 => image at center of screen 1373 1374 setenv splashpos 30,20 1375 => image at x = 30 and y = 20 1376 1377 setenv splashpos -10,m 1378 => vertically centered image 1379 at x = dspWidth - bmpWidth - 9 1380 1381- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1382 1383 If this option is set, additionally to standard BMP 1384 images, gzipped BMP images can be displayed via the 1385 splashscreen support or the bmp command. 1386 1387- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1388 1389 If this option is set, 8-bit RLE compressed BMP images 1390 can be displayed via the splashscreen support or the 1391 bmp command. 1392 1393- Compression support: 1394 CONFIG_GZIP 1395 1396 Enabled by default to support gzip compressed images. 1397 1398 CONFIG_BZIP2 1399 1400 If this option is set, support for bzip2 compressed 1401 images is included. If not, only uncompressed and gzip 1402 compressed images are supported. 1403 1404 NOTE: the bzip2 algorithm requires a lot of RAM, so 1405 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1406 be at least 4MB. 1407 1408- MII/PHY support: 1409 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1410 1411 The clock frequency of the MII bus 1412 1413 CONFIG_PHY_RESET_DELAY 1414 1415 Some PHY like Intel LXT971A need extra delay after 1416 reset before any MII register access is possible. 1417 For such PHY, set this option to the usec delay 1418 required. (minimum 300usec for LXT971A) 1419 1420 CONFIG_PHY_CMD_DELAY (ppc4xx) 1421 1422 Some PHY like Intel LXT971A need extra delay after 1423 command issued before MII status register can be read 1424 1425- IP address: 1426 CONFIG_IPADDR 1427 1428 Define a default value for the IP address to use for 1429 the default Ethernet interface, in case this is not 1430 determined through e.g. bootp. 1431 (Environment variable "ipaddr") 1432 1433- Server IP address: 1434 CONFIG_SERVERIP 1435 1436 Defines a default value for the IP address of a TFTP 1437 server to contact when using the "tftboot" command. 1438 (Environment variable "serverip") 1439 1440 CONFIG_KEEP_SERVERADDR 1441 1442 Keeps the server's MAC address, in the env 'serveraddr' 1443 for passing to bootargs (like Linux's netconsole option) 1444 1445- Gateway IP address: 1446 CONFIG_GATEWAYIP 1447 1448 Defines a default value for the IP address of the 1449 default router where packets to other networks are 1450 sent to. 1451 (Environment variable "gatewayip") 1452 1453- Subnet mask: 1454 CONFIG_NETMASK 1455 1456 Defines a default value for the subnet mask (or 1457 routing prefix) which is used to determine if an IP 1458 address belongs to the local subnet or needs to be 1459 forwarded through a router. 1460 (Environment variable "netmask") 1461 1462- Multicast TFTP Mode: 1463 CONFIG_MCAST_TFTP 1464 1465 Defines whether you want to support multicast TFTP as per 1466 rfc-2090; for example to work with atftp. Lets lots of targets 1467 tftp down the same boot image concurrently. Note: the Ethernet 1468 driver in use must provide a function: mcast() to join/leave a 1469 multicast group. 1470 1471- BOOTP Recovery Mode: 1472 CONFIG_BOOTP_RANDOM_DELAY 1473 1474 If you have many targets in a network that try to 1475 boot using BOOTP, you may want to avoid that all 1476 systems send out BOOTP requests at precisely the same 1477 moment (which would happen for instance at recovery 1478 from a power failure, when all systems will try to 1479 boot, thus flooding the BOOTP server. Defining 1480 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1481 inserted before sending out BOOTP requests. The 1482 following delays are inserted then: 1483 1484 1st BOOTP request: delay 0 ... 1 sec 1485 2nd BOOTP request: delay 0 ... 2 sec 1486 3rd BOOTP request: delay 0 ... 4 sec 1487 4th and following 1488 BOOTP requests: delay 0 ... 8 sec 1489 1490 CONFIG_BOOTP_ID_CACHE_SIZE 1491 1492 BOOTP packets are uniquely identified using a 32-bit ID. The 1493 server will copy the ID from client requests to responses and 1494 U-Boot will use this to determine if it is the destination of 1495 an incoming response. Some servers will check that addresses 1496 aren't in use before handing them out (usually using an ARP 1497 ping) and therefore take up to a few hundred milliseconds to 1498 respond. Network congestion may also influence the time it 1499 takes for a response to make it back to the client. If that 1500 time is too long, U-Boot will retransmit requests. In order 1501 to allow earlier responses to still be accepted after these 1502 retransmissions, U-Boot's BOOTP client keeps a small cache of 1503 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1504 cache. The default is to keep IDs for up to four outstanding 1505 requests. Increasing this will allow U-Boot to accept offers 1506 from a BOOTP client in networks with unusually high latency. 1507 1508- DHCP Advanced Options: 1509 You can fine tune the DHCP functionality by defining 1510 CONFIG_BOOTP_* symbols: 1511 1512 CONFIG_BOOTP_NISDOMAIN 1513 CONFIG_BOOTP_BOOTFILESIZE 1514 CONFIG_BOOTP_SEND_HOSTNAME 1515 CONFIG_BOOTP_NTPSERVER 1516 CONFIG_BOOTP_TIMEOFFSET 1517 CONFIG_BOOTP_VENDOREX 1518 CONFIG_BOOTP_MAY_FAIL 1519 1520 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1521 environment variable, not the BOOTP server. 1522 1523 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1524 after the configured retry count, the call will fail 1525 instead of starting over. This can be used to fail over 1526 to Link-local IP address configuration if the DHCP server 1527 is not available. 1528 1529 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1530 to do a dynamic update of a DNS server. To do this, they 1531 need the hostname of the DHCP requester. 1532 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1533 of the "hostname" environment variable is passed as 1534 option 12 to the DHCP server. 1535 1536 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1537 1538 A 32bit value in microseconds for a delay between 1539 receiving a "DHCP Offer" and sending the "DHCP Request". 1540 This fixes a problem with certain DHCP servers that don't 1541 respond 100% of the time to a "DHCP request". E.g. On an 1542 AT91RM9200 processor running at 180MHz, this delay needed 1543 to be *at least* 15,000 usec before a Windows Server 2003 1544 DHCP server would reply 100% of the time. I recommend at 1545 least 50,000 usec to be safe. The alternative is to hope 1546 that one of the retries will be successful but note that 1547 the DHCP timeout and retry process takes a longer than 1548 this delay. 1549 1550 - Link-local IP address negotiation: 1551 Negotiate with other link-local clients on the local network 1552 for an address that doesn't require explicit configuration. 1553 This is especially useful if a DHCP server cannot be guaranteed 1554 to exist in all environments that the device must operate. 1555 1556 See doc/README.link-local for more information. 1557 1558 - MAC address from environment variables 1559 1560 FDT_SEQ_MACADDR_FROM_ENV 1561 1562 Fix-up device tree with MAC addresses fetched sequentially from 1563 environment variables. This config work on assumption that 1564 non-usable ethernet node of device-tree are either not present 1565 or their status has been marked as "disabled". 1566 1567 - CDP Options: 1568 CONFIG_CDP_DEVICE_ID 1569 1570 The device id used in CDP trigger frames. 1571 1572 CONFIG_CDP_DEVICE_ID_PREFIX 1573 1574 A two character string which is prefixed to the MAC address 1575 of the device. 1576 1577 CONFIG_CDP_PORT_ID 1578 1579 A printf format string which contains the ascii name of 1580 the port. Normally is set to "eth%d" which sets 1581 eth0 for the first Ethernet, eth1 for the second etc. 1582 1583 CONFIG_CDP_CAPABILITIES 1584 1585 A 32bit integer which indicates the device capabilities; 1586 0x00000010 for a normal host which does not forwards. 1587 1588 CONFIG_CDP_VERSION 1589 1590 An ascii string containing the version of the software. 1591 1592 CONFIG_CDP_PLATFORM 1593 1594 An ascii string containing the name of the platform. 1595 1596 CONFIG_CDP_TRIGGER 1597 1598 A 32bit integer sent on the trigger. 1599 1600 CONFIG_CDP_POWER_CONSUMPTION 1601 1602 A 16bit integer containing the power consumption of the 1603 device in .1 of milliwatts. 1604 1605 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1606 1607 A byte containing the id of the VLAN. 1608 1609- Status LED: CONFIG_LED_STATUS 1610 1611 Several configurations allow to display the current 1612 status using a LED. For instance, the LED will blink 1613 fast while running U-Boot code, stop blinking as 1614 soon as a reply to a BOOTP request was received, and 1615 start blinking slow once the Linux kernel is running 1616 (supported by a status LED driver in the Linux 1617 kernel). Defining CONFIG_LED_STATUS enables this 1618 feature in U-Boot. 1619 1620 Additional options: 1621 1622 CONFIG_LED_STATUS_GPIO 1623 The status LED can be connected to a GPIO pin. 1624 In such cases, the gpio_led driver can be used as a 1625 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1626 to include the gpio_led driver in the U-Boot binary. 1627 1628 CONFIG_GPIO_LED_INVERTED_TABLE 1629 Some GPIO connected LEDs may have inverted polarity in which 1630 case the GPIO high value corresponds to LED off state and 1631 GPIO low value corresponds to LED on state. 1632 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1633 with a list of GPIO LEDs that have inverted polarity. 1634 1635- I2C Support: CONFIG_SYS_I2C 1636 1637 This enable the NEW i2c subsystem, and will allow you to use 1638 i2c commands at the u-boot command line (as long as you set 1639 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1640 based realtime clock chips or other i2c devices. See 1641 common/cmd_i2c.c for a description of the command line 1642 interface. 1643 1644 ported i2c driver to the new framework: 1645 - drivers/i2c/soft_i2c.c: 1646 - activate first bus with CONFIG_SYS_I2C_SOFT define 1647 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1648 for defining speed and slave address 1649 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1650 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1651 for defining speed and slave address 1652 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1653 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1654 for defining speed and slave address 1655 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1656 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1657 for defining speed and slave address 1658 1659 - drivers/i2c/fsl_i2c.c: 1660 - activate i2c driver with CONFIG_SYS_I2C_FSL 1661 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1662 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1663 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1664 bus. 1665 - If your board supports a second fsl i2c bus, define 1666 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1667 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1668 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1669 second bus. 1670 1671 - drivers/i2c/tegra_i2c.c: 1672 - activate this driver with CONFIG_SYS_I2C_TEGRA 1673 - This driver adds 4 i2c buses with a fix speed from 1674 100000 and the slave addr 0! 1675 1676 - drivers/i2c/ppc4xx_i2c.c 1677 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1678 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1679 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1680 1681 - drivers/i2c/i2c_mxc.c 1682 - activate this driver with CONFIG_SYS_I2C_MXC 1683 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1684 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1685 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1686 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1687 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1688 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1689 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1690 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1691 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1692 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1693 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1694 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1695 If those defines are not set, default value is 100000 1696 for speed, and 0 for slave. 1697 1698 - drivers/i2c/rcar_i2c.c: 1699 - activate this driver with CONFIG_SYS_I2C_RCAR 1700 - This driver adds 4 i2c buses 1701 1702 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1703 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1704 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1705 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1706 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1707 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1708 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1709 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1710 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1711 1712 - drivers/i2c/sh_i2c.c: 1713 - activate this driver with CONFIG_SYS_I2C_SH 1714 - This driver adds from 2 to 5 i2c buses 1715 1716 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1717 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1718 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1719 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1720 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1721 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1722 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1723 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1724 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1725 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1726 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1727 1728 - drivers/i2c/omap24xx_i2c.c 1729 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1730 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1731 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1732 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1733 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1734 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1735 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1736 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1737 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1738 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1739 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1740 1741 - drivers/i2c/zynq_i2c.c 1742 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1743 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1744 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1745 1746 - drivers/i2c/s3c24x0_i2c.c: 1747 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1748 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1749 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1750 with a fix speed from 100000 and the slave addr 0! 1751 1752 - drivers/i2c/ihs_i2c.c 1753 - activate this driver with CONFIG_SYS_I2C_IHS 1754 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1755 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1756 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1757 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1758 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1759 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1760 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1761 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1762 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1763 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1764 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1765 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1766 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1767 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1768 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1769 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1770 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1771 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1772 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1773 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1774 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1775 1776 additional defines: 1777 1778 CONFIG_SYS_NUM_I2C_BUSES 1779 Hold the number of i2c buses you want to use. 1780 1781 CONFIG_SYS_I2C_DIRECT_BUS 1782 define this, if you don't use i2c muxes on your hardware. 1783 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1784 omit this define. 1785 1786 CONFIG_SYS_I2C_MAX_HOPS 1787 define how many muxes are maximal consecutively connected 1788 on one i2c bus. If you not use i2c muxes, omit this 1789 define. 1790 1791 CONFIG_SYS_I2C_BUSES 1792 hold a list of buses you want to use, only used if 1793 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1794 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1795 CONFIG_SYS_NUM_I2C_BUSES = 9: 1796 1797 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1798 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1799 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1800 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1801 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1802 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1803 {1, {I2C_NULL_HOP}}, \ 1804 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1805 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1806 } 1807 1808 which defines 1809 bus 0 on adapter 0 without a mux 1810 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1811 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1812 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1813 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1814 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1815 bus 6 on adapter 1 without a mux 1816 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1817 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1818 1819 If you do not have i2c muxes on your board, omit this define. 1820 1821- Legacy I2C Support: 1822 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1823 then the following macros need to be defined (examples are 1824 from include/configs/lwmon.h): 1825 1826 I2C_INIT 1827 1828 (Optional). Any commands necessary to enable the I2C 1829 controller or configure ports. 1830 1831 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1832 1833 I2C_ACTIVE 1834 1835 The code necessary to make the I2C data line active 1836 (driven). If the data line is open collector, this 1837 define can be null. 1838 1839 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1840 1841 I2C_TRISTATE 1842 1843 The code necessary to make the I2C data line tri-stated 1844 (inactive). If the data line is open collector, this 1845 define can be null. 1846 1847 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1848 1849 I2C_READ 1850 1851 Code that returns true if the I2C data line is high, 1852 false if it is low. 1853 1854 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1855 1856 I2C_SDA(bit) 1857 1858 If <bit> is true, sets the I2C data line high. If it 1859 is false, it clears it (low). 1860 1861 eg: #define I2C_SDA(bit) \ 1862 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1863 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1864 1865 I2C_SCL(bit) 1866 1867 If <bit> is true, sets the I2C clock line high. If it 1868 is false, it clears it (low). 1869 1870 eg: #define I2C_SCL(bit) \ 1871 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1872 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1873 1874 I2C_DELAY 1875 1876 This delay is invoked four times per clock cycle so this 1877 controls the rate of data transfer. The data rate thus 1878 is 1 / (I2C_DELAY * 4). Often defined to be something 1879 like: 1880 1881 #define I2C_DELAY udelay(2) 1882 1883 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1884 1885 If your arch supports the generic GPIO framework (asm/gpio.h), 1886 then you may alternatively define the two GPIOs that are to be 1887 used as SCL / SDA. Any of the previous I2C_xxx macros will 1888 have GPIO-based defaults assigned to them as appropriate. 1889 1890 You should define these to the GPIO value as given directly to 1891 the generic GPIO functions. 1892 1893 CONFIG_SYS_I2C_INIT_BOARD 1894 1895 When a board is reset during an i2c bus transfer 1896 chips might think that the current transfer is still 1897 in progress. On some boards it is possible to access 1898 the i2c SCLK line directly, either by using the 1899 processor pin as a GPIO or by having a second pin 1900 connected to the bus. If this option is defined a 1901 custom i2c_init_board() routine in boards/xxx/board.c 1902 is run early in the boot sequence. 1903 1904 CONFIG_I2C_MULTI_BUS 1905 1906 This option allows the use of multiple I2C buses, each of which 1907 must have a controller. At any point in time, only one bus is 1908 active. To switch to a different bus, use the 'i2c dev' command. 1909 Note that bus numbering is zero-based. 1910 1911 CONFIG_SYS_I2C_NOPROBES 1912 1913 This option specifies a list of I2C devices that will be skipped 1914 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1915 is set, specify a list of bus-device pairs. Otherwise, specify 1916 a 1D array of device addresses 1917 1918 e.g. 1919 #undef CONFIG_I2C_MULTI_BUS 1920 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1921 1922 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1923 1924 #define CONFIG_I2C_MULTI_BUS 1925 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1926 1927 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1928 1929 CONFIG_SYS_SPD_BUS_NUM 1930 1931 If defined, then this indicates the I2C bus number for DDR SPD. 1932 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1933 1934 CONFIG_SYS_RTC_BUS_NUM 1935 1936 If defined, then this indicates the I2C bus number for the RTC. 1937 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1938 1939 CONFIG_SOFT_I2C_READ_REPEATED_START 1940 1941 defining this will force the i2c_read() function in 1942 the soft_i2c driver to perform an I2C repeated start 1943 between writing the address pointer and reading the 1944 data. If this define is omitted the default behaviour 1945 of doing a stop-start sequence will be used. Most I2C 1946 devices can use either method, but some require one or 1947 the other. 1948 1949- SPI Support: CONFIG_SPI 1950 1951 Enables SPI driver (so far only tested with 1952 SPI EEPROM, also an instance works with Crystal A/D and 1953 D/As on the SACSng board) 1954 1955 CONFIG_SOFT_SPI 1956 1957 Enables a software (bit-bang) SPI driver rather than 1958 using hardware support. This is a general purpose 1959 driver that only requires three general I/O port pins 1960 (two outputs, one input) to function. If this is 1961 defined, the board configuration must define several 1962 SPI configuration items (port pins to use, etc). For 1963 an example, see include/configs/sacsng.h. 1964 1965 CONFIG_HARD_SPI 1966 1967 Enables a hardware SPI driver for general-purpose reads 1968 and writes. As with CONFIG_SOFT_SPI, the board configuration 1969 must define a list of chip-select function pointers. 1970 Currently supported on some MPC8xxx processors. For an 1971 example, see include/configs/mpc8349emds.h. 1972 1973 CONFIG_SYS_SPI_MXC_WAIT 1974 Timeout for waiting until spi transfer completed. 1975 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1976 1977- FPGA Support: CONFIG_FPGA 1978 1979 Enables FPGA subsystem. 1980 1981 CONFIG_FPGA_<vendor> 1982 1983 Enables support for specific chip vendors. 1984 (ALTERA, XILINX) 1985 1986 CONFIG_FPGA_<family> 1987 1988 Enables support for FPGA family. 1989 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1990 1991 CONFIG_FPGA_COUNT 1992 1993 Specify the number of FPGA devices to support. 1994 1995 CONFIG_SYS_FPGA_PROG_FEEDBACK 1996 1997 Enable printing of hash marks during FPGA configuration. 1998 1999 CONFIG_SYS_FPGA_CHECK_BUSY 2000 2001 Enable checks on FPGA configuration interface busy 2002 status by the configuration function. This option 2003 will require a board or device specific function to 2004 be written. 2005 2006 CONFIG_FPGA_DELAY 2007 2008 If defined, a function that provides delays in the FPGA 2009 configuration driver. 2010 2011 CONFIG_SYS_FPGA_CHECK_CTRLC 2012 Allow Control-C to interrupt FPGA configuration 2013 2014 CONFIG_SYS_FPGA_CHECK_ERROR 2015 2016 Check for configuration errors during FPGA bitfile 2017 loading. For example, abort during Virtex II 2018 configuration if the INIT_B line goes low (which 2019 indicated a CRC error). 2020 2021 CONFIG_SYS_FPGA_WAIT_INIT 2022 2023 Maximum time to wait for the INIT_B line to de-assert 2024 after PROB_B has been de-asserted during a Virtex II 2025 FPGA configuration sequence. The default time is 500 2026 ms. 2027 2028 CONFIG_SYS_FPGA_WAIT_BUSY 2029 2030 Maximum time to wait for BUSY to de-assert during 2031 Virtex II FPGA configuration. The default is 5 ms. 2032 2033 CONFIG_SYS_FPGA_WAIT_CONFIG 2034 2035 Time to wait after FPGA configuration. The default is 2036 200 ms. 2037 2038- Configuration Management: 2039 CONFIG_BUILD_TARGET 2040 2041 Some SoCs need special image types (e.g. U-Boot binary 2042 with a special header) as build targets. By defining 2043 CONFIG_BUILD_TARGET in the SoC / board header, this 2044 special image will be automatically built upon calling 2045 make / buildman. 2046 2047 CONFIG_IDENT_STRING 2048 2049 If defined, this string will be added to the U-Boot 2050 version information (U_BOOT_VERSION) 2051 2052- Vendor Parameter Protection: 2053 2054 U-Boot considers the values of the environment 2055 variables "serial#" (Board Serial Number) and 2056 "ethaddr" (Ethernet Address) to be parameters that 2057 are set once by the board vendor / manufacturer, and 2058 protects these variables from casual modification by 2059 the user. Once set, these variables are read-only, 2060 and write or delete attempts are rejected. You can 2061 change this behaviour: 2062 2063 If CONFIG_ENV_OVERWRITE is #defined in your config 2064 file, the write protection for vendor parameters is 2065 completely disabled. Anybody can change or delete 2066 these parameters. 2067 2068 Alternatively, if you define _both_ an ethaddr in the 2069 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2070 Ethernet address is installed in the environment, 2071 which can be changed exactly ONCE by the user. [The 2072 serial# is unaffected by this, i. e. it remains 2073 read-only.] 2074 2075 The same can be accomplished in a more flexible way 2076 for any variable by configuring the type of access 2077 to allow for those variables in the ".flags" variable 2078 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2079 2080- Protected RAM: 2081 CONFIG_PRAM 2082 2083 Define this variable to enable the reservation of 2084 "protected RAM", i. e. RAM which is not overwritten 2085 by U-Boot. Define CONFIG_PRAM to hold the number of 2086 kB you want to reserve for pRAM. You can overwrite 2087 this default value by defining an environment 2088 variable "pram" to the number of kB you want to 2089 reserve. Note that the board info structure will 2090 still show the full amount of RAM. If pRAM is 2091 reserved, a new environment variable "mem" will 2092 automatically be defined to hold the amount of 2093 remaining RAM in a form that can be passed as boot 2094 argument to Linux, for instance like that: 2095 2096 setenv bootargs ... mem=\${mem} 2097 saveenv 2098 2099 This way you can tell Linux not to use this memory, 2100 either, which results in a memory region that will 2101 not be affected by reboots. 2102 2103 *WARNING* If your board configuration uses automatic 2104 detection of the RAM size, you must make sure that 2105 this memory test is non-destructive. So far, the 2106 following board configurations are known to be 2107 "pRAM-clean": 2108 2109 IVMS8, IVML24, SPD8xx, 2110 HERMES, IP860, RPXlite, LWMON, 2111 FLAGADM 2112 2113- Access to physical memory region (> 4GB) 2114 Some basic support is provided for operations on memory not 2115 normally accessible to U-Boot - e.g. some architectures 2116 support access to more than 4GB of memory on 32-bit 2117 machines using physical address extension or similar. 2118 Define CONFIG_PHYSMEM to access this basic support, which 2119 currently only supports clearing the memory. 2120 2121- Error Recovery: 2122 CONFIG_NET_RETRY_COUNT 2123 2124 This variable defines the number of retries for 2125 network operations like ARP, RARP, TFTP, or BOOTP 2126 before giving up the operation. If not defined, a 2127 default value of 5 is used. 2128 2129 CONFIG_ARP_TIMEOUT 2130 2131 Timeout waiting for an ARP reply in milliseconds. 2132 2133 CONFIG_NFS_TIMEOUT 2134 2135 Timeout in milliseconds used in NFS protocol. 2136 If you encounter "ERROR: Cannot umount" in nfs command, 2137 try longer timeout such as 2138 #define CONFIG_NFS_TIMEOUT 10000UL 2139 2140- Command Interpreter: 2141 CONFIG_SYS_PROMPT_HUSH_PS2 2142 2143 This defines the secondary prompt string, which is 2144 printed when the command interpreter needs more input 2145 to complete a command. Usually "> ". 2146 2147 Note: 2148 2149 In the current implementation, the local variables 2150 space and global environment variables space are 2151 separated. Local variables are those you define by 2152 simply typing `name=value'. To access a local 2153 variable later on, you have write `$name' or 2154 `${name}'; to execute the contents of a variable 2155 directly type `$name' at the command prompt. 2156 2157 Global environment variables are those you use 2158 setenv/printenv to work with. To run a command stored 2159 in such a variable, you need to use the run command, 2160 and you must not use the '$' sign to access them. 2161 2162 To store commands and special characters in a 2163 variable, please use double quotation marks 2164 surrounding the whole text of the variable, instead 2165 of the backslashes before semicolons and special 2166 symbols. 2167 2168- Command Line Editing and History: 2169 CONFIG_CMDLINE_PS_SUPPORT 2170 2171 Enable support for changing the command prompt string 2172 at run-time. Only static string is supported so far. 2173 The string is obtained from environment variables PS1 2174 and PS2. 2175 2176- Default Environment: 2177 CONFIG_EXTRA_ENV_SETTINGS 2178 2179 Define this to contain any number of null terminated 2180 strings (variable = value pairs) that will be part of 2181 the default environment compiled into the boot image. 2182 2183 For example, place something like this in your 2184 board's config file: 2185 2186 #define CONFIG_EXTRA_ENV_SETTINGS \ 2187 "myvar1=value1\0" \ 2188 "myvar2=value2\0" 2189 2190 Warning: This method is based on knowledge about the 2191 internal format how the environment is stored by the 2192 U-Boot code. This is NOT an official, exported 2193 interface! Although it is unlikely that this format 2194 will change soon, there is no guarantee either. 2195 You better know what you are doing here. 2196 2197 Note: overly (ab)use of the default environment is 2198 discouraged. Make sure to check other ways to preset 2199 the environment like the "source" command or the 2200 boot command first. 2201 2202 CONFIG_DELAY_ENVIRONMENT 2203 2204 Normally the environment is loaded when the board is 2205 initialised so that it is available to U-Boot. This inhibits 2206 that so that the environment is not available until 2207 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2208 this is instead controlled by the value of 2209 /config/load-environment. 2210 2211- Serial Flash support 2212 Usage requires an initial 'sf probe' to define the serial 2213 flash parameters, followed by read/write/erase/update 2214 commands. 2215 2216 The following defaults may be provided by the platform 2217 to handle the common case when only a single serial 2218 flash is present on the system. 2219 2220 CONFIG_SF_DEFAULT_BUS Bus identifier 2221 CONFIG_SF_DEFAULT_CS Chip-select 2222 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2223 CONFIG_SF_DEFAULT_SPEED in Hz 2224 2225 2226- TFTP Fixed UDP Port: 2227 CONFIG_TFTP_PORT 2228 2229 If this is defined, the environment variable tftpsrcp 2230 is used to supply the TFTP UDP source port value. 2231 If tftpsrcp isn't defined, the normal pseudo-random port 2232 number generator is used. 2233 2234 Also, the environment variable tftpdstp is used to supply 2235 the TFTP UDP destination port value. If tftpdstp isn't 2236 defined, the normal port 69 is used. 2237 2238 The purpose for tftpsrcp is to allow a TFTP server to 2239 blindly start the TFTP transfer using the pre-configured 2240 target IP address and UDP port. This has the effect of 2241 "punching through" the (Windows XP) firewall, allowing 2242 the remainder of the TFTP transfer to proceed normally. 2243 A better solution is to properly configure the firewall, 2244 but sometimes that is not allowed. 2245 2246- Show boot progress: 2247 CONFIG_SHOW_BOOT_PROGRESS 2248 2249 Defining this option allows to add some board- 2250 specific code (calling a user-provided function 2251 "show_boot_progress(int)") that enables you to show 2252 the system's boot progress on some display (for 2253 example, some LED's) on your board. At the moment, 2254 the following checkpoints are implemented: 2255 2256 2257Legacy uImage format: 2258 2259 Arg Where When 2260 1 common/cmd_bootm.c before attempting to boot an image 2261 -1 common/cmd_bootm.c Image header has bad magic number 2262 2 common/cmd_bootm.c Image header has correct magic number 2263 -2 common/cmd_bootm.c Image header has bad checksum 2264 3 common/cmd_bootm.c Image header has correct checksum 2265 -3 common/cmd_bootm.c Image data has bad checksum 2266 4 common/cmd_bootm.c Image data has correct checksum 2267 -4 common/cmd_bootm.c Image is for unsupported architecture 2268 5 common/cmd_bootm.c Architecture check OK 2269 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2270 6 common/cmd_bootm.c Image Type check OK 2271 -6 common/cmd_bootm.c gunzip uncompression error 2272 -7 common/cmd_bootm.c Unimplemented compression type 2273 7 common/cmd_bootm.c Uncompression OK 2274 8 common/cmd_bootm.c No uncompress/copy overwrite error 2275 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2276 2277 9 common/image.c Start initial ramdisk verification 2278 -10 common/image.c Ramdisk header has bad magic number 2279 -11 common/image.c Ramdisk header has bad checksum 2280 10 common/image.c Ramdisk header is OK 2281 -12 common/image.c Ramdisk data has bad checksum 2282 11 common/image.c Ramdisk data has correct checksum 2283 12 common/image.c Ramdisk verification complete, start loading 2284 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2285 13 common/image.c Start multifile image verification 2286 14 common/image.c No initial ramdisk, no multifile, continue. 2287 2288 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2289 2290 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2291 -31 post/post.c POST test failed, detected by post_output_backlog() 2292 -32 post/post.c POST test failed, detected by post_run_single() 2293 2294 34 common/cmd_doc.c before loading a Image from a DOC device 2295 -35 common/cmd_doc.c Bad usage of "doc" command 2296 35 common/cmd_doc.c correct usage of "doc" command 2297 -36 common/cmd_doc.c No boot device 2298 36 common/cmd_doc.c correct boot device 2299 -37 common/cmd_doc.c Unknown Chip ID on boot device 2300 37 common/cmd_doc.c correct chip ID found, device available 2301 -38 common/cmd_doc.c Read Error on boot device 2302 38 common/cmd_doc.c reading Image header from DOC device OK 2303 -39 common/cmd_doc.c Image header has bad magic number 2304 39 common/cmd_doc.c Image header has correct magic number 2305 -40 common/cmd_doc.c Error reading Image from DOC device 2306 40 common/cmd_doc.c Image header has correct magic number 2307 41 common/cmd_ide.c before loading a Image from a IDE device 2308 -42 common/cmd_ide.c Bad usage of "ide" command 2309 42 common/cmd_ide.c correct usage of "ide" command 2310 -43 common/cmd_ide.c No boot device 2311 43 common/cmd_ide.c boot device found 2312 -44 common/cmd_ide.c Device not available 2313 44 common/cmd_ide.c Device available 2314 -45 common/cmd_ide.c wrong partition selected 2315 45 common/cmd_ide.c partition selected 2316 -46 common/cmd_ide.c Unknown partition table 2317 46 common/cmd_ide.c valid partition table found 2318 -47 common/cmd_ide.c Invalid partition type 2319 47 common/cmd_ide.c correct partition type 2320 -48 common/cmd_ide.c Error reading Image Header on boot device 2321 48 common/cmd_ide.c reading Image Header from IDE device OK 2322 -49 common/cmd_ide.c Image header has bad magic number 2323 49 common/cmd_ide.c Image header has correct magic number 2324 -50 common/cmd_ide.c Image header has bad checksum 2325 50 common/cmd_ide.c Image header has correct checksum 2326 -51 common/cmd_ide.c Error reading Image from IDE device 2327 51 common/cmd_ide.c reading Image from IDE device OK 2328 52 common/cmd_nand.c before loading a Image from a NAND device 2329 -53 common/cmd_nand.c Bad usage of "nand" command 2330 53 common/cmd_nand.c correct usage of "nand" command 2331 -54 common/cmd_nand.c No boot device 2332 54 common/cmd_nand.c boot device found 2333 -55 common/cmd_nand.c Unknown Chip ID on boot device 2334 55 common/cmd_nand.c correct chip ID found, device available 2335 -56 common/cmd_nand.c Error reading Image Header on boot device 2336 56 common/cmd_nand.c reading Image Header from NAND device OK 2337 -57 common/cmd_nand.c Image header has bad magic number 2338 57 common/cmd_nand.c Image header has correct magic number 2339 -58 common/cmd_nand.c Error reading Image from NAND device 2340 58 common/cmd_nand.c reading Image from NAND device OK 2341 2342 -60 common/env_common.c Environment has a bad CRC, using default 2343 2344 64 net/eth.c starting with Ethernet configuration. 2345 -64 net/eth.c no Ethernet found. 2346 65 net/eth.c Ethernet found. 2347 2348 -80 common/cmd_net.c usage wrong 2349 80 common/cmd_net.c before calling net_loop() 2350 -81 common/cmd_net.c some error in net_loop() occurred 2351 81 common/cmd_net.c net_loop() back without error 2352 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2353 82 common/cmd_net.c trying automatic boot 2354 83 common/cmd_net.c running "source" command 2355 -83 common/cmd_net.c some error in automatic boot or "source" command 2356 84 common/cmd_net.c end without errors 2357 2358FIT uImage format: 2359 2360 Arg Where When 2361 100 common/cmd_bootm.c Kernel FIT Image has correct format 2362 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2363 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2364 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2365 102 common/cmd_bootm.c Kernel unit name specified 2366 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2367 103 common/cmd_bootm.c Found configuration node 2368 104 common/cmd_bootm.c Got kernel subimage node offset 2369 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2370 105 common/cmd_bootm.c Kernel subimage hash verification OK 2371 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2372 106 common/cmd_bootm.c Architecture check OK 2373 -106 common/cmd_bootm.c Kernel subimage has wrong type 2374 107 common/cmd_bootm.c Kernel subimage type OK 2375 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2376 108 common/cmd_bootm.c Got kernel subimage data/size 2377 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2378 -109 common/cmd_bootm.c Can't get kernel subimage type 2379 -110 common/cmd_bootm.c Can't get kernel subimage comp 2380 -111 common/cmd_bootm.c Can't get kernel subimage os 2381 -112 common/cmd_bootm.c Can't get kernel subimage load address 2382 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2383 2384 120 common/image.c Start initial ramdisk verification 2385 -120 common/image.c Ramdisk FIT image has incorrect format 2386 121 common/image.c Ramdisk FIT image has correct format 2387 122 common/image.c No ramdisk subimage unit name, using configuration 2388 -122 common/image.c Can't get configuration for ramdisk subimage 2389 123 common/image.c Ramdisk unit name specified 2390 -124 common/image.c Can't get ramdisk subimage node offset 2391 125 common/image.c Got ramdisk subimage node offset 2392 -125 common/image.c Ramdisk subimage hash verification failed 2393 126 common/image.c Ramdisk subimage hash verification OK 2394 -126 common/image.c Ramdisk subimage for unsupported architecture 2395 127 common/image.c Architecture check OK 2396 -127 common/image.c Can't get ramdisk subimage data/size 2397 128 common/image.c Got ramdisk subimage data/size 2398 129 common/image.c Can't get ramdisk load address 2399 -129 common/image.c Got ramdisk load address 2400 2401 -130 common/cmd_doc.c Incorrect FIT image format 2402 131 common/cmd_doc.c FIT image format OK 2403 2404 -140 common/cmd_ide.c Incorrect FIT image format 2405 141 common/cmd_ide.c FIT image format OK 2406 2407 -150 common/cmd_nand.c Incorrect FIT image format 2408 151 common/cmd_nand.c FIT image format OK 2409 2410- Standalone program support: 2411 CONFIG_STANDALONE_LOAD_ADDR 2412 2413 This option defines a board specific value for the 2414 address where standalone program gets loaded, thus 2415 overwriting the architecture dependent default 2416 settings. 2417 2418- Frame Buffer Address: 2419 CONFIG_FB_ADDR 2420 2421 Define CONFIG_FB_ADDR if you want to use specific 2422 address for frame buffer. This is typically the case 2423 when using a graphics controller has separate video 2424 memory. U-Boot will then place the frame buffer at 2425 the given address instead of dynamically reserving it 2426 in system RAM by calling lcd_setmem(), which grabs 2427 the memory for the frame buffer depending on the 2428 configured panel size. 2429 2430 Please see board_init_f function. 2431 2432- Automatic software updates via TFTP server 2433 CONFIG_UPDATE_TFTP 2434 CONFIG_UPDATE_TFTP_CNT_MAX 2435 CONFIG_UPDATE_TFTP_MSEC_MAX 2436 2437 These options enable and control the auto-update feature; 2438 for a more detailed description refer to doc/README.update. 2439 2440- MTD Support (mtdparts command, UBI support) 2441 CONFIG_MTD_DEVICE 2442 2443 Adds the MTD device infrastructure from the Linux kernel. 2444 Needed for mtdparts command support. 2445 2446 CONFIG_MTD_PARTITIONS 2447 2448 Adds the MTD partitioning infrastructure from the Linux 2449 kernel. Needed for UBI support. 2450 2451- UBI support 2452 CONFIG_MTD_UBI_WL_THRESHOLD 2453 This parameter defines the maximum difference between the highest 2454 erase counter value and the lowest erase counter value of eraseblocks 2455 of UBI devices. When this threshold is exceeded, UBI starts performing 2456 wear leveling by means of moving data from eraseblock with low erase 2457 counter to eraseblocks with high erase counter. 2458 2459 The default value should be OK for SLC NAND flashes, NOR flashes and 2460 other flashes which have eraseblock life-cycle 100000 or more. 2461 However, in case of MLC NAND flashes which typically have eraseblock 2462 life-cycle less than 10000, the threshold should be lessened (e.g., 2463 to 128 or 256, although it does not have to be power of 2). 2464 2465 default: 4096 2466 2467 CONFIG_MTD_UBI_BEB_LIMIT 2468 This option specifies the maximum bad physical eraseblocks UBI 2469 expects on the MTD device (per 1024 eraseblocks). If the 2470 underlying flash does not admit of bad eraseblocks (e.g. NOR 2471 flash), this value is ignored. 2472 2473 NAND datasheets often specify the minimum and maximum NVM 2474 (Number of Valid Blocks) for the flashes' endurance lifetime. 2475 The maximum expected bad eraseblocks per 1024 eraseblocks 2476 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2477 which gives 20 for most NANDs (MaxNVB is basically the total 2478 count of eraseblocks on the chip). 2479 2480 To put it differently, if this value is 20, UBI will try to 2481 reserve about 1.9% of physical eraseblocks for bad blocks 2482 handling. And that will be 1.9% of eraseblocks on the entire 2483 NAND chip, not just the MTD partition UBI attaches. This means 2484 that if you have, say, a NAND flash chip admits maximum 40 bad 2485 eraseblocks, and it is split on two MTD partitions of the same 2486 size, UBI will reserve 40 eraseblocks when attaching a 2487 partition. 2488 2489 default: 20 2490 2491 CONFIG_MTD_UBI_FASTMAP 2492 Fastmap is a mechanism which allows attaching an UBI device 2493 in nearly constant time. Instead of scanning the whole MTD device it 2494 only has to locate a checkpoint (called fastmap) on the device. 2495 The on-flash fastmap contains all information needed to attach 2496 the device. Using fastmap makes only sense on large devices where 2497 attaching by scanning takes long. UBI will not automatically install 2498 a fastmap on old images, but you can set the UBI parameter 2499 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2500 that fastmap-enabled images are still usable with UBI implementations 2501 without fastmap support. On typical flash devices the whole fastmap 2502 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2503 2504 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2505 Set this parameter to enable fastmap automatically on images 2506 without a fastmap. 2507 default: 0 2508 2509 CONFIG_MTD_UBI_FM_DEBUG 2510 Enable UBI fastmap debug 2511 default: 0 2512 2513- SPL framework 2514 CONFIG_SPL 2515 Enable building of SPL globally. 2516 2517 CONFIG_SPL_LDSCRIPT 2518 LDSCRIPT for linking the SPL binary. 2519 2520 CONFIG_SPL_MAX_FOOTPRINT 2521 Maximum size in memory allocated to the SPL, BSS included. 2522 When defined, the linker checks that the actual memory 2523 used by SPL from _start to __bss_end does not exceed it. 2524 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2525 must not be both defined at the same time. 2526 2527 CONFIG_SPL_MAX_SIZE 2528 Maximum size of the SPL image (text, data, rodata, and 2529 linker lists sections), BSS excluded. 2530 When defined, the linker checks that the actual size does 2531 not exceed it. 2532 2533 CONFIG_SPL_TEXT_BASE 2534 TEXT_BASE for linking the SPL binary. 2535 2536 CONFIG_SPL_RELOC_TEXT_BASE 2537 Address to relocate to. If unspecified, this is equal to 2538 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2539 2540 CONFIG_SPL_BSS_START_ADDR 2541 Link address for the BSS within the SPL binary. 2542 2543 CONFIG_SPL_BSS_MAX_SIZE 2544 Maximum size in memory allocated to the SPL BSS. 2545 When defined, the linker checks that the actual memory used 2546 by SPL from __bss_start to __bss_end does not exceed it. 2547 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2548 must not be both defined at the same time. 2549 2550 CONFIG_SPL_STACK 2551 Adress of the start of the stack SPL will use 2552 2553 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2554 When defined, SPL will panic() if the image it has 2555 loaded does not have a signature. 2556 Defining this is useful when code which loads images 2557 in SPL cannot guarantee that absolutely all read errors 2558 will be caught. 2559 An example is the LPC32XX MLC NAND driver, which will 2560 consider that a completely unreadable NAND block is bad, 2561 and thus should be skipped silently. 2562 2563 CONFIG_SPL_RELOC_STACK 2564 Adress of the start of the stack SPL will use after 2565 relocation. If unspecified, this is equal to 2566 CONFIG_SPL_STACK. 2567 2568 CONFIG_SYS_SPL_MALLOC_START 2569 Starting address of the malloc pool used in SPL. 2570 When this option is set the full malloc is used in SPL and 2571 it is set up by spl_init() and before that, the simple malloc() 2572 can be used if CONFIG_SYS_MALLOC_F is defined. 2573 2574 CONFIG_SYS_SPL_MALLOC_SIZE 2575 The size of the malloc pool used in SPL. 2576 2577 CONFIG_SPL_OS_BOOT 2578 Enable booting directly to an OS from SPL. 2579 See also: doc/README.falcon 2580 2581 CONFIG_SPL_DISPLAY_PRINT 2582 For ARM, enable an optional function to print more information 2583 about the running system. 2584 2585 CONFIG_SPL_INIT_MINIMAL 2586 Arch init code should be built for a very small image 2587 2588 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2589 Partition on the MMC to load U-Boot from when the MMC is being 2590 used in raw mode 2591 2592 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2593 Sector to load kernel uImage from when MMC is being 2594 used in raw mode (for Falcon mode) 2595 2596 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2597 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2598 Sector and number of sectors to load kernel argument 2599 parameters from when MMC is being used in raw mode 2600 (for falcon mode) 2601 2602 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2603 Partition on the MMC to load U-Boot from when the MMC is being 2604 used in fs mode 2605 2606 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2607 Filename to read to load U-Boot when reading from filesystem 2608 2609 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2610 Filename to read to load kernel uImage when reading 2611 from filesystem (for Falcon mode) 2612 2613 CONFIG_SPL_FS_LOAD_ARGS_NAME 2614 Filename to read to load kernel argument parameters 2615 when reading from filesystem (for Falcon mode) 2616 2617 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2618 Set this for NAND SPL on PPC mpc83xx targets, so that 2619 start.S waits for the rest of the SPL to load before 2620 continuing (the hardware starts execution after just 2621 loading the first page rather than the full 4K). 2622 2623 CONFIG_SPL_SKIP_RELOCATE 2624 Avoid SPL relocation 2625 2626 CONFIG_SPL_NAND_BASE 2627 Include nand_base.c in the SPL. Requires 2628 CONFIG_SPL_NAND_DRIVERS. 2629 2630 CONFIG_SPL_NAND_DRIVERS 2631 SPL uses normal NAND drivers, not minimal drivers. 2632 2633 CONFIG_SPL_NAND_ECC 2634 Include standard software ECC in the SPL 2635 2636 CONFIG_SPL_NAND_SIMPLE 2637 Support for NAND boot using simple NAND drivers that 2638 expose the cmd_ctrl() interface. 2639 2640 CONFIG_SPL_UBI 2641 Support for a lightweight UBI (fastmap) scanner and 2642 loader 2643 2644 CONFIG_SPL_NAND_RAW_ONLY 2645 Support to boot only raw u-boot.bin images. Use this only 2646 if you need to save space. 2647 2648 CONFIG_SPL_COMMON_INIT_DDR 2649 Set for common ddr init with serial presence detect in 2650 SPL binary. 2651 2652 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2653 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2654 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2655 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2656 CONFIG_SYS_NAND_ECCBYTES 2657 Defines the size and behavior of the NAND that SPL uses 2658 to read U-Boot 2659 2660 CONFIG_SPL_NAND_BOOT 2661 Add support NAND boot 2662 2663 CONFIG_SYS_NAND_U_BOOT_OFFS 2664 Location in NAND to read U-Boot from 2665 2666 CONFIG_SYS_NAND_U_BOOT_DST 2667 Location in memory to load U-Boot to 2668 2669 CONFIG_SYS_NAND_U_BOOT_SIZE 2670 Size of image to load 2671 2672 CONFIG_SYS_NAND_U_BOOT_START 2673 Entry point in loaded image to jump to 2674 2675 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2676 Define this if you need to first read the OOB and then the 2677 data. This is used, for example, on davinci platforms. 2678 2679 CONFIG_SPL_RAM_DEVICE 2680 Support for running image already present in ram, in SPL binary 2681 2682 CONFIG_SPL_PAD_TO 2683 Image offset to which the SPL should be padded before appending 2684 the SPL payload. By default, this is defined as 2685 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2686 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2687 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2688 2689 CONFIG_SPL_TARGET 2690 Final target image containing SPL and payload. Some SPLs 2691 use an arch-specific makefile fragment instead, for 2692 example if more than one image needs to be produced. 2693 2694 CONFIG_SPL_FIT_PRINT 2695 Printing information about a FIT image adds quite a bit of 2696 code to SPL. So this is normally disabled in SPL. Use this 2697 option to re-enable it. This will affect the output of the 2698 bootm command when booting a FIT image. 2699 2700- TPL framework 2701 CONFIG_TPL 2702 Enable building of TPL globally. 2703 2704 CONFIG_TPL_PAD_TO 2705 Image offset to which the TPL should be padded before appending 2706 the TPL payload. By default, this is defined as 2707 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2708 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2709 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2710 2711- Interrupt support (PPC): 2712 2713 There are common interrupt_init() and timer_interrupt() 2714 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2715 for CPU specific initialization. interrupt_init_cpu() 2716 should set decrementer_count to appropriate value. If 2717 CPU resets decrementer automatically after interrupt 2718 (ppc4xx) it should set decrementer_count to zero. 2719 timer_interrupt() calls timer_interrupt_cpu() for CPU 2720 specific handling. If board has watchdog / status_led 2721 / other_activity_monitor it works automatically from 2722 general timer_interrupt(). 2723 2724 2725Board initialization settings: 2726------------------------------ 2727 2728During Initialization u-boot calls a number of board specific functions 2729to allow the preparation of board specific prerequisites, e.g. pin setup 2730before drivers are initialized. To enable these callbacks the 2731following configuration macros have to be defined. Currently this is 2732architecture specific, so please check arch/your_architecture/lib/board.c 2733typically in board_init_f() and board_init_r(). 2734 2735- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2736- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2737- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2738- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2739 2740Configuration Settings: 2741----------------------- 2742 2743- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2744 Optionally it can be defined to support 64-bit memory commands. 2745 2746- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2747 undefine this when you're short of memory. 2748 2749- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2750 width of the commands listed in the 'help' command output. 2751 2752- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2753 prompt for user input. 2754 2755- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2756 2757- CONFIG_SYS_PBSIZE: Buffer size for Console output 2758 2759- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2760 2761- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2762 the application (usually a Linux kernel) when it is 2763 booted 2764 2765- CONFIG_SYS_BAUDRATE_TABLE: 2766 List of legal baudrate settings for this board. 2767 2768- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2769 Begin and End addresses of the area used by the 2770 simple memory test. 2771 2772- CONFIG_SYS_MEMTEST_SCRATCH: 2773 Scratch address used by the alternate memory test 2774 You only need to set this if address zero isn't writeable 2775 2776- CONFIG_SYS_MEM_RESERVE_SECURE 2777 Only implemented for ARMv8 for now. 2778 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2779 is substracted from total RAM and won't be reported to OS. 2780 This memory can be used as secure memory. A variable 2781 gd->arch.secure_ram is used to track the location. In systems 2782 the RAM base is not zero, or RAM is divided into banks, 2783 this variable needs to be recalcuated to get the address. 2784 2785- CONFIG_SYS_MEM_TOP_HIDE: 2786 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2787 this specified memory area will get subtracted from the top 2788 (end) of RAM and won't get "touched" at all by U-Boot. By 2789 fixing up gd->ram_size the Linux kernel should gets passed 2790 the now "corrected" memory size and won't touch it either. 2791 This should work for arch/ppc and arch/powerpc. Only Linux 2792 board ports in arch/powerpc with bootwrapper support that 2793 recalculate the memory size from the SDRAM controller setup 2794 will have to get fixed in Linux additionally. 2795 2796 This option can be used as a workaround for the 440EPx/GRx 2797 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2798 be touched. 2799 2800 WARNING: Please make sure that this value is a multiple of 2801 the Linux page size (normally 4k). If this is not the case, 2802 then the end address of the Linux memory will be located at a 2803 non page size aligned address and this could cause major 2804 problems. 2805 2806- CONFIG_SYS_LOADS_BAUD_CHANGE: 2807 Enable temporary baudrate change while serial download 2808 2809- CONFIG_SYS_SDRAM_BASE: 2810 Physical start address of SDRAM. _Must_ be 0 here. 2811 2812- CONFIG_SYS_FLASH_BASE: 2813 Physical start address of Flash memory. 2814 2815- CONFIG_SYS_MONITOR_BASE: 2816 Physical start address of boot monitor code (set by 2817 make config files to be same as the text base address 2818 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2819 CONFIG_SYS_FLASH_BASE when booting from flash. 2820 2821- CONFIG_SYS_MONITOR_LEN: 2822 Size of memory reserved for monitor code, used to 2823 determine _at_compile_time_ (!) if the environment is 2824 embedded within the U-Boot image, or in a separate 2825 flash sector. 2826 2827- CONFIG_SYS_MALLOC_LEN: 2828 Size of DRAM reserved for malloc() use. 2829 2830- CONFIG_SYS_MALLOC_F_LEN 2831 Size of the malloc() pool for use before relocation. If 2832 this is defined, then a very simple malloc() implementation 2833 will become available before relocation. The address is just 2834 below the global data, and the stack is moved down to make 2835 space. 2836 2837 This feature allocates regions with increasing addresses 2838 within the region. calloc() is supported, but realloc() 2839 is not available. free() is supported but does nothing. 2840 The memory will be freed (or in fact just forgotten) when 2841 U-Boot relocates itself. 2842 2843- CONFIG_SYS_MALLOC_SIMPLE 2844 Provides a simple and small malloc() and calloc() for those 2845 boards which do not use the full malloc in SPL (which is 2846 enabled with CONFIG_SYS_SPL_MALLOC_START). 2847 2848- CONFIG_SYS_NONCACHED_MEMORY: 2849 Size of non-cached memory area. This area of memory will be 2850 typically located right below the malloc() area and mapped 2851 uncached in the MMU. This is useful for drivers that would 2852 otherwise require a lot of explicit cache maintenance. For 2853 some drivers it's also impossible to properly maintain the 2854 cache. For example if the regions that need to be flushed 2855 are not a multiple of the cache-line size, *and* padding 2856 cannot be allocated between the regions to align them (i.e. 2857 if the HW requires a contiguous array of regions, and the 2858 size of each region is not cache-aligned), then a flush of 2859 one region may result in overwriting data that hardware has 2860 written to another region in the same cache-line. This can 2861 happen for example in network drivers where descriptors for 2862 buffers are typically smaller than the CPU cache-line (e.g. 2863 16 bytes vs. 32 or 64 bytes). 2864 2865 Non-cached memory is only supported on 32-bit ARM at present. 2866 2867- CONFIG_SYS_BOOTM_LEN: 2868 Normally compressed uImages are limited to an 2869 uncompressed size of 8 MBytes. If this is not enough, 2870 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2871 to adjust this setting to your needs. 2872 2873- CONFIG_SYS_BOOTMAPSZ: 2874 Maximum size of memory mapped by the startup code of 2875 the Linux kernel; all data that must be processed by 2876 the Linux kernel (bd_info, boot arguments, FDT blob if 2877 used) must be put below this limit, unless "bootm_low" 2878 environment variable is defined and non-zero. In such case 2879 all data for the Linux kernel must be between "bootm_low" 2880 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2881 variable "bootm_mapsize" will override the value of 2882 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2883 then the value in "bootm_size" will be used instead. 2884 2885- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2886 Enable initrd_high functionality. If defined then the 2887 initrd_high feature is enabled and the bootm ramdisk subcommand 2888 is enabled. 2889 2890- CONFIG_SYS_BOOT_GET_CMDLINE: 2891 Enables allocating and saving kernel cmdline in space between 2892 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2893 2894- CONFIG_SYS_BOOT_GET_KBD: 2895 Enables allocating and saving a kernel copy of the bd_info in 2896 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2897 2898- CONFIG_SYS_MAX_FLASH_BANKS: 2899 Max number of Flash memory banks 2900 2901- CONFIG_SYS_MAX_FLASH_SECT: 2902 Max number of sectors on a Flash chip 2903 2904- CONFIG_SYS_FLASH_ERASE_TOUT: 2905 Timeout for Flash erase operations (in ms) 2906 2907- CONFIG_SYS_FLASH_WRITE_TOUT: 2908 Timeout for Flash write operations (in ms) 2909 2910- CONFIG_SYS_FLASH_LOCK_TOUT 2911 Timeout for Flash set sector lock bit operation (in ms) 2912 2913- CONFIG_SYS_FLASH_UNLOCK_TOUT 2914 Timeout for Flash clear lock bits operation (in ms) 2915 2916- CONFIG_SYS_FLASH_PROTECTION 2917 If defined, hardware flash sectors protection is used 2918 instead of U-Boot software protection. 2919 2920- CONFIG_SYS_DIRECT_FLASH_TFTP: 2921 2922 Enable TFTP transfers directly to flash memory; 2923 without this option such a download has to be 2924 performed in two steps: (1) download to RAM, and (2) 2925 copy from RAM to flash. 2926 2927 The two-step approach is usually more reliable, since 2928 you can check if the download worked before you erase 2929 the flash, but in some situations (when system RAM is 2930 too limited to allow for a temporary copy of the 2931 downloaded image) this option may be very useful. 2932 2933- CONFIG_SYS_FLASH_CFI: 2934 Define if the flash driver uses extra elements in the 2935 common flash structure for storing flash geometry. 2936 2937- CONFIG_FLASH_CFI_DRIVER 2938 This option also enables the building of the cfi_flash driver 2939 in the drivers directory 2940 2941- CONFIG_FLASH_CFI_MTD 2942 This option enables the building of the cfi_mtd driver 2943 in the drivers directory. The driver exports CFI flash 2944 to the MTD layer. 2945 2946- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2947 Use buffered writes to flash. 2948 2949- CONFIG_FLASH_SPANSION_S29WS_N 2950 s29ws-n MirrorBit flash has non-standard addresses for buffered 2951 write commands. 2952 2953- CONFIG_SYS_FLASH_QUIET_TEST 2954 If this option is defined, the common CFI flash doesn't 2955 print it's warning upon not recognized FLASH banks. This 2956 is useful, if some of the configured banks are only 2957 optionally available. 2958 2959- CONFIG_FLASH_SHOW_PROGRESS 2960 If defined (must be an integer), print out countdown 2961 digits and dots. Recommended value: 45 (9..1) for 80 2962 column displays, 15 (3..1) for 40 column displays. 2963 2964- CONFIG_FLASH_VERIFY 2965 If defined, the content of the flash (destination) is compared 2966 against the source after the write operation. An error message 2967 will be printed when the contents are not identical. 2968 Please note that this option is useless in nearly all cases, 2969 since such flash programming errors usually are detected earlier 2970 while unprotecting/erasing/programming. Please only enable 2971 this option if you really know what you are doing. 2972 2973- CONFIG_SYS_RX_ETH_BUFFER: 2974 Defines the number of Ethernet receive buffers. On some 2975 Ethernet controllers it is recommended to set this value 2976 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2977 buffers can be full shortly after enabling the interface 2978 on high Ethernet traffic. 2979 Defaults to 4 if not defined. 2980 2981- CONFIG_ENV_MAX_ENTRIES 2982 2983 Maximum number of entries in the hash table that is used 2984 internally to store the environment settings. The default 2985 setting is supposed to be generous and should work in most 2986 cases. This setting can be used to tune behaviour; see 2987 lib/hashtable.c for details. 2988 2989- CONFIG_ENV_FLAGS_LIST_DEFAULT 2990- CONFIG_ENV_FLAGS_LIST_STATIC 2991 Enable validation of the values given to environment variables when 2992 calling env set. Variables can be restricted to only decimal, 2993 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 2994 the variables can also be restricted to IP address or MAC address. 2995 2996 The format of the list is: 2997 type_attribute = [s|d|x|b|i|m] 2998 access_attribute = [a|r|o|c] 2999 attributes = type_attribute[access_attribute] 3000 entry = variable_name[:attributes] 3001 list = entry[,list] 3002 3003 The type attributes are: 3004 s - String (default) 3005 d - Decimal 3006 x - Hexadecimal 3007 b - Boolean ([1yYtT|0nNfF]) 3008 i - IP address 3009 m - MAC address 3010 3011 The access attributes are: 3012 a - Any (default) 3013 r - Read-only 3014 o - Write-once 3015 c - Change-default 3016 3017 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3018 Define this to a list (string) to define the ".flags" 3019 environment variable in the default or embedded environment. 3020 3021 - CONFIG_ENV_FLAGS_LIST_STATIC 3022 Define this to a list (string) to define validation that 3023 should be done if an entry is not found in the ".flags" 3024 environment variable. To override a setting in the static 3025 list, simply add an entry for the same variable name to the 3026 ".flags" variable. 3027 3028 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3029 regular expression. This allows multiple variables to define the same 3030 flags without explicitly listing them for each variable. 3031 3032- CONFIG_ENV_ACCESS_IGNORE_FORCE 3033 If defined, don't allow the -f switch to env set override variable 3034 access flags. 3035 3036- CONFIG_USE_STDINT 3037 If stdint.h is available with your toolchain you can define this 3038 option to enable it. You can provide option 'USE_STDINT=1' when 3039 building U-Boot to enable this. 3040 3041The following definitions that deal with the placement and management 3042of environment data (variable area); in general, we support the 3043following configurations: 3044 3045- CONFIG_BUILD_ENVCRC: 3046 3047 Builds up envcrc with the target environment so that external utils 3048 may easily extract it and embed it in final U-Boot images. 3049 3050BE CAREFUL! The first access to the environment happens quite early 3051in U-Boot initialization (when we try to get the setting of for the 3052console baudrate). You *MUST* have mapped your NVRAM area then, or 3053U-Boot will hang. 3054 3055Please note that even with NVRAM we still use a copy of the 3056environment in RAM: we could work on NVRAM directly, but we want to 3057keep settings there always unmodified except somebody uses "saveenv" 3058to save the current settings. 3059 3060BE CAREFUL! For some special cases, the local device can not use 3061"saveenv" command. For example, the local device will get the 3062environment stored in a remote NOR flash by SRIO or PCIE link, 3063but it can not erase, write this NOR flash by SRIO or PCIE interface. 3064 3065- CONFIG_NAND_ENV_DST 3066 3067 Defines address in RAM to which the nand_spl code should copy the 3068 environment. If redundant environment is used, it will be copied to 3069 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3070 3071Please note that the environment is read-only until the monitor 3072has been relocated to RAM and a RAM copy of the environment has been 3073created; also, when using EEPROM you will have to use env_get_f() 3074until then to read environment variables. 3075 3076The environment is protected by a CRC32 checksum. Before the monitor 3077is relocated into RAM, as a result of a bad CRC you will be working 3078with the compiled-in default environment - *silently*!!! [This is 3079necessary, because the first environment variable we need is the 3080"baudrate" setting for the console - if we have a bad CRC, we don't 3081have any device yet where we could complain.] 3082 3083Note: once the monitor has been relocated, then it will complain if 3084the default environment is used; a new CRC is computed as soon as you 3085use the "saveenv" command to store a valid environment. 3086 3087- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3088 Echo the inverted Ethernet link state to the fault LED. 3089 3090 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3091 also needs to be defined. 3092 3093- CONFIG_SYS_FAULT_MII_ADDR: 3094 MII address of the PHY to check for the Ethernet link state. 3095 3096- CONFIG_NS16550_MIN_FUNCTIONS: 3097 Define this if you desire to only have use of the NS16550_init 3098 and NS16550_putc functions for the serial driver located at 3099 drivers/serial/ns16550.c. This option is useful for saving 3100 space for already greatly restricted images, including but not 3101 limited to NAND_SPL configurations. 3102 3103- CONFIG_DISPLAY_BOARDINFO 3104 Display information about the board that U-Boot is running on 3105 when U-Boot starts up. The board function checkboard() is called 3106 to do this. 3107 3108- CONFIG_DISPLAY_BOARDINFO_LATE 3109 Similar to the previous option, but display this information 3110 later, once stdio is running and output goes to the LCD, if 3111 present. 3112 3113- CONFIG_BOARD_SIZE_LIMIT: 3114 Maximum size of the U-Boot image. When defined, the 3115 build system checks that the actual size does not 3116 exceed it. 3117 3118Low Level (hardware related) configuration options: 3119--------------------------------------------------- 3120 3121- CONFIG_SYS_CACHELINE_SIZE: 3122 Cache Line Size of the CPU. 3123 3124- CONFIG_SYS_CCSRBAR_DEFAULT: 3125 Default (power-on reset) physical address of CCSR on Freescale 3126 PowerPC SOCs. 3127 3128- CONFIG_SYS_CCSRBAR: 3129 Virtual address of CCSR. On a 32-bit build, this is typically 3130 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3131 3132- CONFIG_SYS_CCSRBAR_PHYS: 3133 Physical address of CCSR. CCSR can be relocated to a new 3134 physical address, if desired. In this case, this macro should 3135 be set to that address. Otherwise, it should be set to the 3136 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3137 is typically relocated on 36-bit builds. It is recommended 3138 that this macro be defined via the _HIGH and _LOW macros: 3139 3140 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3141 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3142 3143- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3144 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3145 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3146 used in assembly code, so it must not contain typecasts or 3147 integer size suffixes (e.g. "ULL"). 3148 3149- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3150 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3151 used in assembly code, so it must not contain typecasts or 3152 integer size suffixes (e.g. "ULL"). 3153 3154- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3155 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3156 forced to a value that ensures that CCSR is not relocated. 3157 3158- Floppy Disk Support: 3159 CONFIG_SYS_FDC_DRIVE_NUMBER 3160 3161 the default drive number (default value 0) 3162 3163 CONFIG_SYS_ISA_IO_STRIDE 3164 3165 defines the spacing between FDC chipset registers 3166 (default value 1) 3167 3168 CONFIG_SYS_ISA_IO_OFFSET 3169 3170 defines the offset of register from address. It 3171 depends on which part of the data bus is connected to 3172 the FDC chipset. (default value 0) 3173 3174 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3175 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3176 default value. 3177 3178 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3179 fdc_hw_init() is called at the beginning of the FDC 3180 setup. fdc_hw_init() must be provided by the board 3181 source code. It is used to make hardware-dependent 3182 initializations. 3183 3184- CONFIG_IDE_AHB: 3185 Most IDE controllers were designed to be connected with PCI 3186 interface. Only few of them were designed for AHB interface. 3187 When software is doing ATA command and data transfer to 3188 IDE devices through IDE-AHB controller, some additional 3189 registers accessing to these kind of IDE-AHB controller 3190 is required. 3191 3192- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3193 DO NOT CHANGE unless you know exactly what you're 3194 doing! (11-4) [MPC8xx systems only] 3195 3196- CONFIG_SYS_INIT_RAM_ADDR: 3197 3198 Start address of memory area that can be used for 3199 initial data and stack; please note that this must be 3200 writable memory that is working WITHOUT special 3201 initialization, i. e. you CANNOT use normal RAM which 3202 will become available only after programming the 3203 memory controller and running certain initialization 3204 sequences. 3205 3206 U-Boot uses the following memory types: 3207 - MPC8xx: IMMR (internal memory of the CPU) 3208 3209- CONFIG_SYS_GBL_DATA_OFFSET: 3210 3211 Offset of the initial data structure in the memory 3212 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3213 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3214 data is located at the end of the available space 3215 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3216 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3217 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3218 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3219 3220 Note: 3221 On the MPC824X (or other systems that use the data 3222 cache for initial memory) the address chosen for 3223 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3224 point to an otherwise UNUSED address space between 3225 the top of RAM and the start of the PCI space. 3226 3227- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3228 3229- CONFIG_SYS_OR_TIMING_SDRAM: 3230 SDRAM timing 3231 3232- CONFIG_SYS_MAMR_PTA: 3233 periodic timer for refresh 3234 3235- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3236 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3237 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3238 CONFIG_SYS_BR1_PRELIM: 3239 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3240 3241- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3242 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3243 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3244 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3245 3246- CONFIG_PCI_ENUM_ONLY 3247 Only scan through and get the devices on the buses. 3248 Don't do any setup work, presumably because someone or 3249 something has already done it, and we don't need to do it 3250 a second time. Useful for platforms that are pre-booted 3251 by coreboot or similar. 3252 3253- CONFIG_PCI_INDIRECT_BRIDGE: 3254 Enable support for indirect PCI bridges. 3255 3256- CONFIG_SYS_SRIO: 3257 Chip has SRIO or not 3258 3259- CONFIG_SRIO1: 3260 Board has SRIO 1 port available 3261 3262- CONFIG_SRIO2: 3263 Board has SRIO 2 port available 3264 3265- CONFIG_SRIO_PCIE_BOOT_MASTER 3266 Board can support master function for Boot from SRIO and PCIE 3267 3268- CONFIG_SYS_SRIOn_MEM_VIRT: 3269 Virtual Address of SRIO port 'n' memory region 3270 3271- CONFIG_SYS_SRIOn_MEM_PHYS: 3272 Physical Address of SRIO port 'n' memory region 3273 3274- CONFIG_SYS_SRIOn_MEM_SIZE: 3275 Size of SRIO port 'n' memory region 3276 3277- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3278 Defined to tell the NAND controller that the NAND chip is using 3279 a 16 bit bus. 3280 Not all NAND drivers use this symbol. 3281 Example of drivers that use it: 3282 - drivers/mtd/nand/ndfc.c 3283 - drivers/mtd/nand/mxc_nand.c 3284 3285- CONFIG_SYS_NDFC_EBC0_CFG 3286 Sets the EBC0_CFG register for the NDFC. If not defined 3287 a default value will be used. 3288 3289- CONFIG_SPD_EEPROM 3290 Get DDR timing information from an I2C EEPROM. Common 3291 with pluggable memory modules such as SODIMMs 3292 3293 SPD_EEPROM_ADDRESS 3294 I2C address of the SPD EEPROM 3295 3296- CONFIG_SYS_SPD_BUS_NUM 3297 If SPD EEPROM is on an I2C bus other than the first 3298 one, specify here. Note that the value must resolve 3299 to something your driver can deal with. 3300 3301- CONFIG_SYS_DDR_RAW_TIMING 3302 Get DDR timing information from other than SPD. Common with 3303 soldered DDR chips onboard without SPD. DDR raw timing 3304 parameters are extracted from datasheet and hard-coded into 3305 header files or board specific files. 3306 3307- CONFIG_FSL_DDR_INTERACTIVE 3308 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3309 3310- CONFIG_FSL_DDR_SYNC_REFRESH 3311 Enable sync of refresh for multiple controllers. 3312 3313- CONFIG_FSL_DDR_BIST 3314 Enable built-in memory test for Freescale DDR controllers. 3315 3316- CONFIG_SYS_83XX_DDR_USES_CS0 3317 Only for 83xx systems. If specified, then DDR should 3318 be configured using CS0 and CS1 instead of CS2 and CS3. 3319 3320- CONFIG_RMII 3321 Enable RMII mode for all FECs. 3322 Note that this is a global option, we can't 3323 have one FEC in standard MII mode and another in RMII mode. 3324 3325- CONFIG_CRC32_VERIFY 3326 Add a verify option to the crc32 command. 3327 The syntax is: 3328 3329 => crc32 -v <address> <count> <crc32> 3330 3331 Where address/count indicate a memory area 3332 and crc32 is the correct crc32 which the 3333 area should have. 3334 3335- CONFIG_LOOPW 3336 Add the "loopw" memory command. This only takes effect if 3337 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3338 3339- CONFIG_MX_CYCLIC 3340 Add the "mdc" and "mwc" memory commands. These are cyclic 3341 "md/mw" commands. 3342 Examples: 3343 3344 => mdc.b 10 4 500 3345 This command will print 4 bytes (10,11,12,13) each 500 ms. 3346 3347 => mwc.l 100 12345678 10 3348 This command will write 12345678 to address 100 all 10 ms. 3349 3350 This only takes effect if the memory commands are activated 3351 globally (CONFIG_CMD_MEMORY). 3352 3353- CONFIG_SKIP_LOWLEVEL_INIT 3354 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3355 low level initializations (like setting up the memory 3356 controller) are omitted and/or U-Boot does not 3357 relocate itself into RAM. 3358 3359 Normally this variable MUST NOT be defined. The only 3360 exception is when U-Boot is loaded (to RAM) by some 3361 other boot loader or by a debugger which performs 3362 these initializations itself. 3363 3364- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3365 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3366 to be skipped. The normal CP15 init (such as enabling the 3367 instruction cache) is still performed. 3368 3369- CONFIG_SPL_BUILD 3370 Modifies the behaviour of start.S when compiling a loader 3371 that is executed before the actual U-Boot. E.g. when 3372 compiling a NAND SPL. 3373 3374- CONFIG_TPL_BUILD 3375 Modifies the behaviour of start.S when compiling a loader 3376 that is executed after the SPL and before the actual U-Boot. 3377 It is loaded by the SPL. 3378 3379- CONFIG_SYS_MPC85XX_NO_RESETVEC 3380 Only for 85xx systems. If this variable is specified, the section 3381 .resetvec is not kept and the section .bootpg is placed in the 3382 previous 4k of the .text section. 3383 3384- CONFIG_ARCH_MAP_SYSMEM 3385 Generally U-Boot (and in particular the md command) uses 3386 effective address. It is therefore not necessary to regard 3387 U-Boot address as virtual addresses that need to be translated 3388 to physical addresses. However, sandbox requires this, since 3389 it maintains its own little RAM buffer which contains all 3390 addressable memory. This option causes some memory accesses 3391 to be mapped through map_sysmem() / unmap_sysmem(). 3392 3393- CONFIG_X86_RESET_VECTOR 3394 If defined, the x86 reset vector code is included. This is not 3395 needed when U-Boot is running from Coreboot. 3396 3397- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3398 Option to disable subpage write in NAND driver 3399 driver that uses this: 3400 drivers/mtd/nand/davinci_nand.c 3401 3402Freescale QE/FMAN Firmware Support: 3403----------------------------------- 3404 3405The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3406loading of "firmware", which is encoded in the QE firmware binary format. 3407This firmware often needs to be loaded during U-Boot booting, so macros 3408are used to identify the storage device (NOR flash, SPI, etc) and the address 3409within that device. 3410 3411- CONFIG_SYS_FMAN_FW_ADDR 3412 The address in the storage device where the FMAN microcode is located. The 3413 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3414 is also specified. 3415 3416- CONFIG_SYS_QE_FW_ADDR 3417 The address in the storage device where the QE microcode is located. The 3418 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3419 is also specified. 3420 3421- CONFIG_SYS_QE_FMAN_FW_LENGTH 3422 The maximum possible size of the firmware. The firmware binary format 3423 has a field that specifies the actual size of the firmware, but it 3424 might not be possible to read any part of the firmware unless some 3425 local storage is allocated to hold the entire firmware first. 3426 3427- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3428 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3429 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3430 virtual address in NOR flash. 3431 3432- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3433 Specifies that QE/FMAN firmware is located in NAND flash. 3434 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3435 3436- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3437 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3438 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3439 3440- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3441 Specifies that QE/FMAN firmware is located in the remote (master) 3442 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3443 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3444 window->master inbound window->master LAW->the ucode address in 3445 master's memory space. 3446 3447Freescale Layerscape Management Complex Firmware Support: 3448--------------------------------------------------------- 3449The Freescale Layerscape Management Complex (MC) supports the loading of 3450"firmware". 3451This firmware often needs to be loaded during U-Boot booting, so macros 3452are used to identify the storage device (NOR flash, SPI, etc) and the address 3453within that device. 3454 3455- CONFIG_FSL_MC_ENET 3456 Enable the MC driver for Layerscape SoCs. 3457 3458Freescale Layerscape Debug Server Support: 3459------------------------------------------- 3460The Freescale Layerscape Debug Server Support supports the loading of 3461"Debug Server firmware" and triggering SP boot-rom. 3462This firmware often needs to be loaded during U-Boot booting. 3463 3464- CONFIG_SYS_MC_RSV_MEM_ALIGN 3465 Define alignment of reserved memory MC requires 3466 3467Reproducible builds 3468------------------- 3469 3470In order to achieve reproducible builds, timestamps used in the U-Boot build 3471process have to be set to a fixed value. 3472 3473This is done using the SOURCE_DATE_EPOCH environment variable. 3474SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3475option for U-Boot or an environment variable in U-Boot. 3476 3477SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3478 3479Building the Software: 3480====================== 3481 3482Building U-Boot has been tested in several native build environments 3483and in many different cross environments. Of course we cannot support 3484all possibly existing versions of cross development tools in all 3485(potentially obsolete) versions. In case of tool chain problems we 3486recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3487which is extensively used to build and test U-Boot. 3488 3489If you are not using a native environment, it is assumed that you 3490have GNU cross compiling tools available in your path. In this case, 3491you must set the environment variable CROSS_COMPILE in your shell. 3492Note that no changes to the Makefile or any other source files are 3493necessary. For example using the ELDK on a 4xx CPU, please enter: 3494 3495 $ CROSS_COMPILE=ppc_4xx- 3496 $ export CROSS_COMPILE 3497 3498Note: If you wish to generate Windows versions of the utilities in 3499 the tools directory you can use the MinGW toolchain 3500 (http://www.mingw.org). Set your HOST tools to the MinGW 3501 toolchain and execute 'make tools'. For example: 3502 3503 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3504 3505 Binaries such as tools/mkimage.exe will be created which can 3506 be executed on computers running Windows. 3507 3508U-Boot is intended to be simple to build. After installing the 3509sources you must configure U-Boot for one specific board type. This 3510is done by typing: 3511 3512 make NAME_defconfig 3513 3514where "NAME_defconfig" is the name of one of the existing configu- 3515rations; see boards.cfg for supported names. 3516 3517Note: for some board special configuration names may exist; check if 3518 additional information is available from the board vendor; for 3519 instance, the TQM823L systems are available without (standard) 3520 or with LCD support. You can select such additional "features" 3521 when choosing the configuration, i. e. 3522 3523 make TQM823L_defconfig 3524 - will configure for a plain TQM823L, i. e. no LCD support 3525 3526 make TQM823L_LCD_defconfig 3527 - will configure for a TQM823L with U-Boot console on LCD 3528 3529 etc. 3530 3531 3532Finally, type "make all", and you should get some working U-Boot 3533images ready for download to / installation on your system: 3534 3535- "u-boot.bin" is a raw binary image 3536- "u-boot" is an image in ELF binary format 3537- "u-boot.srec" is in Motorola S-Record format 3538 3539By default the build is performed locally and the objects are saved 3540in the source directory. One of the two methods can be used to change 3541this behavior and build U-Boot to some external directory: 3542 35431. Add O= to the make command line invocations: 3544 3545 make O=/tmp/build distclean 3546 make O=/tmp/build NAME_defconfig 3547 make O=/tmp/build all 3548 35492. Set environment variable KBUILD_OUTPUT to point to the desired location: 3550 3551 export KBUILD_OUTPUT=/tmp/build 3552 make distclean 3553 make NAME_defconfig 3554 make all 3555 3556Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3557variable. 3558 3559User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3560setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3561For example to treat all compiler warnings as errors: 3562 3563 make KCFLAGS=-Werror 3564 3565Please be aware that the Makefiles assume you are using GNU make, so 3566for instance on NetBSD you might need to use "gmake" instead of 3567native "make". 3568 3569 3570If the system board that you have is not listed, then you will need 3571to port U-Boot to your hardware platform. To do this, follow these 3572steps: 3573 35741. Create a new directory to hold your board specific code. Add any 3575 files you need. In your board directory, you will need at least 3576 the "Makefile" and a "<board>.c". 35772. Create a new configuration file "include/configs/<board>.h" for 3578 your board. 35793. If you're porting U-Boot to a new CPU, then also create a new 3580 directory to hold your CPU specific code. Add any files you need. 35814. Run "make <board>_defconfig" with your new name. 35825. Type "make", and you should get a working "u-boot.srec" file 3583 to be installed on your target system. 35846. Debug and solve any problems that might arise. 3585 [Of course, this last step is much harder than it sounds.] 3586 3587 3588Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3589============================================================== 3590 3591If you have modified U-Boot sources (for instance added a new board 3592or support for new devices, a new CPU, etc.) you are expected to 3593provide feedback to the other developers. The feedback normally takes 3594the form of a "patch", i. e. a context diff against a certain (latest 3595official or latest in the git repository) version of U-Boot sources. 3596 3597But before you submit such a patch, please verify that your modifi- 3598cation did not break existing code. At least make sure that *ALL* of 3599the supported boards compile WITHOUT ANY compiler warnings. To do so, 3600just run the buildman script (tools/buildman/buildman), which will 3601configure and build U-Boot for ALL supported system. Be warned, this 3602will take a while. Please see the buildman README, or run 'buildman -H' 3603for documentation. 3604 3605 3606See also "U-Boot Porting Guide" below. 3607 3608 3609Monitor Commands - Overview: 3610============================ 3611 3612go - start application at address 'addr' 3613run - run commands in an environment variable 3614bootm - boot application image from memory 3615bootp - boot image via network using BootP/TFTP protocol 3616bootz - boot zImage from memory 3617tftpboot- boot image via network using TFTP protocol 3618 and env variables "ipaddr" and "serverip" 3619 (and eventually "gatewayip") 3620tftpput - upload a file via network using TFTP protocol 3621rarpboot- boot image via network using RARP/TFTP protocol 3622diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3623loads - load S-Record file over serial line 3624loadb - load binary file over serial line (kermit mode) 3625md - memory display 3626mm - memory modify (auto-incrementing) 3627nm - memory modify (constant address) 3628mw - memory write (fill) 3629cp - memory copy 3630cmp - memory compare 3631crc32 - checksum calculation 3632i2c - I2C sub-system 3633sspi - SPI utility commands 3634base - print or set address offset 3635printenv- print environment variables 3636setenv - set environment variables 3637saveenv - save environment variables to persistent storage 3638protect - enable or disable FLASH write protection 3639erase - erase FLASH memory 3640flinfo - print FLASH memory information 3641nand - NAND memory operations (see doc/README.nand) 3642bdinfo - print Board Info structure 3643iminfo - print header information for application image 3644coninfo - print console devices and informations 3645ide - IDE sub-system 3646loop - infinite loop on address range 3647loopw - infinite write loop on address range 3648mtest - simple RAM test 3649icache - enable or disable instruction cache 3650dcache - enable or disable data cache 3651reset - Perform RESET of the CPU 3652echo - echo args to console 3653version - print monitor version 3654help - print online help 3655? - alias for 'help' 3656 3657 3658Monitor Commands - Detailed Description: 3659======================================== 3660 3661TODO. 3662 3663For now: just type "help <command>". 3664 3665 3666Environment Variables: 3667====================== 3668 3669U-Boot supports user configuration using Environment Variables which 3670can be made persistent by saving to Flash memory. 3671 3672Environment Variables are set using "setenv", printed using 3673"printenv", and saved to Flash using "saveenv". Using "setenv" 3674without a value can be used to delete a variable from the 3675environment. As long as you don't save the environment you are 3676working with an in-memory copy. In case the Flash area containing the 3677environment is erased by accident, a default environment is provided. 3678 3679Some configuration options can be set using Environment Variables. 3680 3681List of environment variables (most likely not complete): 3682 3683 baudrate - see CONFIG_BAUDRATE 3684 3685 bootdelay - see CONFIG_BOOTDELAY 3686 3687 bootcmd - see CONFIG_BOOTCOMMAND 3688 3689 bootargs - Boot arguments when booting an RTOS image 3690 3691 bootfile - Name of the image to load with TFTP 3692 3693 bootm_low - Memory range available for image processing in the bootm 3694 command can be restricted. This variable is given as 3695 a hexadecimal number and defines lowest address allowed 3696 for use by the bootm command. See also "bootm_size" 3697 environment variable. Address defined by "bootm_low" is 3698 also the base of the initial memory mapping for the Linux 3699 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3700 bootm_mapsize. 3701 3702 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3703 This variable is given as a hexadecimal number and it 3704 defines the size of the memory region starting at base 3705 address bootm_low that is accessible by the Linux kernel 3706 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3707 as the default value if it is defined, and bootm_size is 3708 used otherwise. 3709 3710 bootm_size - Memory range available for image processing in the bootm 3711 command can be restricted. This variable is given as 3712 a hexadecimal number and defines the size of the region 3713 allowed for use by the bootm command. See also "bootm_low" 3714 environment variable. 3715 3716 updatefile - Location of the software update file on a TFTP server, used 3717 by the automatic software update feature. Please refer to 3718 documentation in doc/README.update for more details. 3719 3720 autoload - if set to "no" (any string beginning with 'n'), 3721 "bootp" will just load perform a lookup of the 3722 configuration from the BOOTP server, but not try to 3723 load any image using TFTP 3724 3725 autostart - if set to "yes", an image loaded using the "bootp", 3726 "rarpboot", "tftpboot" or "diskboot" commands will 3727 be automatically started (by internally calling 3728 "bootm") 3729 3730 If set to "no", a standalone image passed to the 3731 "bootm" command will be copied to the load address 3732 (and eventually uncompressed), but NOT be started. 3733 This can be used to load and uncompress arbitrary 3734 data. 3735 3736 fdt_high - if set this restricts the maximum address that the 3737 flattened device tree will be copied into upon boot. 3738 For example, if you have a system with 1 GB memory 3739 at physical address 0x10000000, while Linux kernel 3740 only recognizes the first 704 MB as low memory, you 3741 may need to set fdt_high as 0x3C000000 to have the 3742 device tree blob be copied to the maximum address 3743 of the 704 MB low memory, so that Linux kernel can 3744 access it during the boot procedure. 3745 3746 If this is set to the special value 0xFFFFFFFF then 3747 the fdt will not be copied at all on boot. For this 3748 to work it must reside in writable memory, have 3749 sufficient padding on the end of it for u-boot to 3750 add the information it needs into it, and the memory 3751 must be accessible by the kernel. 3752 3753 fdtcontroladdr- if set this is the address of the control flattened 3754 device tree used by U-Boot when CONFIG_OF_CONTROL is 3755 defined. 3756 3757 i2cfast - (PPC405GP|PPC405EP only) 3758 if set to 'y' configures Linux I2C driver for fast 3759 mode (400kHZ). This environment variable is used in 3760 initialization code. So, for changes to be effective 3761 it must be saved and board must be reset. 3762 3763 initrd_high - restrict positioning of initrd images: 3764 If this variable is not set, initrd images will be 3765 copied to the highest possible address in RAM; this 3766 is usually what you want since it allows for 3767 maximum initrd size. If for some reason you want to 3768 make sure that the initrd image is loaded below the 3769 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3770 variable to a value of "no" or "off" or "0". 3771 Alternatively, you can set it to a maximum upper 3772 address to use (U-Boot will still check that it 3773 does not overwrite the U-Boot stack and data). 3774 3775 For instance, when you have a system with 16 MB 3776 RAM, and want to reserve 4 MB from use by Linux, 3777 you can do this by adding "mem=12M" to the value of 3778 the "bootargs" variable. However, now you must make 3779 sure that the initrd image is placed in the first 3780 12 MB as well - this can be done with 3781 3782 setenv initrd_high 00c00000 3783 3784 If you set initrd_high to 0xFFFFFFFF, this is an 3785 indication to U-Boot that all addresses are legal 3786 for the Linux kernel, including addresses in flash 3787 memory. In this case U-Boot will NOT COPY the 3788 ramdisk at all. This may be useful to reduce the 3789 boot time on your system, but requires that this 3790 feature is supported by your Linux kernel. 3791 3792 ipaddr - IP address; needed for tftpboot command 3793 3794 loadaddr - Default load address for commands like "bootp", 3795 "rarpboot", "tftpboot", "loadb" or "diskboot" 3796 3797 loads_echo - see CONFIG_LOADS_ECHO 3798 3799 serverip - TFTP server IP address; needed for tftpboot command 3800 3801 bootretry - see CONFIG_BOOT_RETRY_TIME 3802 3803 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3804 3805 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3806 3807 ethprime - controls which interface is used first. 3808 3809 ethact - controls which interface is currently active. 3810 For example you can do the following 3811 3812 => setenv ethact FEC 3813 => ping 192.168.0.1 # traffic sent on FEC 3814 => setenv ethact SCC 3815 => ping 10.0.0.1 # traffic sent on SCC 3816 3817 ethrotate - When set to "no" U-Boot does not go through all 3818 available network interfaces. 3819 It just stays at the currently selected interface. 3820 3821 netretry - When set to "no" each network operation will 3822 either succeed or fail without retrying. 3823 When set to "once" the network operation will 3824 fail when all the available network interfaces 3825 are tried once without success. 3826 Useful on scripts which control the retry operation 3827 themselves. 3828 3829 npe_ucode - set load address for the NPE microcode 3830 3831 silent_linux - If set then Linux will be told to boot silently, by 3832 changing the console to be empty. If "yes" it will be 3833 made silent. If "no" it will not be made silent. If 3834 unset, then it will be made silent if the U-Boot console 3835 is silent. 3836 3837 tftpsrcp - If this is set, the value is used for TFTP's 3838 UDP source port. 3839 3840 tftpdstp - If this is set, the value is used for TFTP's UDP 3841 destination port instead of the Well Know Port 69. 3842 3843 tftpblocksize - Block size to use for TFTP transfers; if not set, 3844 we use the TFTP server's default block size 3845 3846 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3847 seconds, minimum value is 1000 = 1 second). Defines 3848 when a packet is considered to be lost so it has to 3849 be retransmitted. The default is 5000 = 5 seconds. 3850 Lowering this value may make downloads succeed 3851 faster in networks with high packet loss rates or 3852 with unreliable TFTP servers. 3853 3854 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3855 unit, minimum value = 0). Defines how many timeouts 3856 can happen during a single file transfer before that 3857 transfer is aborted. The default is 10, and 0 means 3858 'no timeouts allowed'. Increasing this value may help 3859 downloads succeed with high packet loss rates, or with 3860 unreliable TFTP servers or client hardware. 3861 3862 vlan - When set to a value < 4095 the traffic over 3863 Ethernet is encapsulated/received over 802.1q 3864 VLAN tagged frames. 3865 3866 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3867 Unsigned value, in milliseconds. If not set, the period will 3868 be either the default (28000), or a value based on 3869 CONFIG_NET_RETRY_COUNT, if defined. This value has 3870 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3871 3872The following image location variables contain the location of images 3873used in booting. The "Image" column gives the role of the image and is 3874not an environment variable name. The other columns are environment 3875variable names. "File Name" gives the name of the file on a TFTP 3876server, "RAM Address" gives the location in RAM the image will be 3877loaded to, and "Flash Location" gives the image's address in NOR 3878flash or offset in NAND flash. 3879 3880*Note* - these variables don't have to be defined for all boards, some 3881boards currently use other variables for these purposes, and some 3882boards use these variables for other purposes. 3883 3884Image File Name RAM Address Flash Location 3885----- --------- ----------- -------------- 3886u-boot u-boot u-boot_addr_r u-boot_addr 3887Linux kernel bootfile kernel_addr_r kernel_addr 3888device tree blob fdtfile fdt_addr_r fdt_addr 3889ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3890 3891The following environment variables may be used and automatically 3892updated by the network boot commands ("bootp" and "rarpboot"), 3893depending the information provided by your boot server: 3894 3895 bootfile - see above 3896 dnsip - IP address of your Domain Name Server 3897 dnsip2 - IP address of your secondary Domain Name Server 3898 gatewayip - IP address of the Gateway (Router) to use 3899 hostname - Target hostname 3900 ipaddr - see above 3901 netmask - Subnet Mask 3902 rootpath - Pathname of the root filesystem on the NFS server 3903 serverip - see above 3904 3905 3906There are two special Environment Variables: 3907 3908 serial# - contains hardware identification information such 3909 as type string and/or serial number 3910 ethaddr - Ethernet address 3911 3912These variables can be set only once (usually during manufacturing of 3913the board). U-Boot refuses to delete or overwrite these variables 3914once they have been set once. 3915 3916 3917Further special Environment Variables: 3918 3919 ver - Contains the U-Boot version string as printed 3920 with the "version" command. This variable is 3921 readonly (see CONFIG_VERSION_VARIABLE). 3922 3923 3924Please note that changes to some configuration parameters may take 3925only effect after the next boot (yes, that's just like Windoze :-). 3926 3927 3928Callback functions for environment variables: 3929--------------------------------------------- 3930 3931For some environment variables, the behavior of u-boot needs to change 3932when their values are changed. This functionality allows functions to 3933be associated with arbitrary variables. On creation, overwrite, or 3934deletion, the callback will provide the opportunity for some side 3935effect to happen or for the change to be rejected. 3936 3937The callbacks are named and associated with a function using the 3938U_BOOT_ENV_CALLBACK macro in your board or driver code. 3939 3940These callbacks are associated with variables in one of two ways. The 3941static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3942in the board configuration to a string that defines a list of 3943associations. The list must be in the following format: 3944 3945 entry = variable_name[:callback_name] 3946 list = entry[,list] 3947 3948If the callback name is not specified, then the callback is deleted. 3949Spaces are also allowed anywhere in the list. 3950 3951Callbacks can also be associated by defining the ".callbacks" variable 3952with the same list format above. Any association in ".callbacks" will 3953override any association in the static list. You can define 3954CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 3955".callbacks" environment variable in the default or embedded environment. 3956 3957If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3958regular expression. This allows multiple variables to be connected to 3959the same callback without explicitly listing them all out. 3960 3961 3962Command Line Parsing: 3963===================== 3964 3965There are two different command line parsers available with U-Boot: 3966the old "simple" one, and the much more powerful "hush" shell: 3967 3968Old, simple command line parser: 3969-------------------------------- 3970 3971- supports environment variables (through setenv / saveenv commands) 3972- several commands on one line, separated by ';' 3973- variable substitution using "... ${name} ..." syntax 3974- special characters ('$', ';') can be escaped by prefixing with '\', 3975 for example: 3976 setenv bootcmd bootm \${address} 3977- You can also escape text by enclosing in single apostrophes, for example: 3978 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 3979 3980Hush shell: 3981----------- 3982 3983- similar to Bourne shell, with control structures like 3984 if...then...else...fi, for...do...done; while...do...done, 3985 until...do...done, ... 3986- supports environment ("global") variables (through setenv / saveenv 3987 commands) and local shell variables (through standard shell syntax 3988 "name=value"); only environment variables can be used with "run" 3989 command 3990 3991General rules: 3992-------------- 3993 3994(1) If a command line (or an environment variable executed by a "run" 3995 command) contains several commands separated by semicolon, and 3996 one of these commands fails, then the remaining commands will be 3997 executed anyway. 3998 3999(2) If you execute several variables with one call to run (i. e. 4000 calling run with a list of variables as arguments), any failing 4001 command will cause "run" to terminate, i. e. the remaining 4002 variables are not executed. 4003 4004Note for Redundant Ethernet Interfaces: 4005======================================= 4006 4007Some boards come with redundant Ethernet interfaces; U-Boot supports 4008such configurations and is capable of automatic selection of a 4009"working" interface when needed. MAC assignment works as follows: 4010 4011Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4012MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4013"eth1addr" (=>eth1), "eth2addr", ... 4014 4015If the network interface stores some valid MAC address (for instance 4016in SROM), this is used as default address if there is NO correspon- 4017ding setting in the environment; if the corresponding environment 4018variable is set, this overrides the settings in the card; that means: 4019 4020o If the SROM has a valid MAC address, and there is no address in the 4021 environment, the SROM's address is used. 4022 4023o If there is no valid address in the SROM, and a definition in the 4024 environment exists, then the value from the environment variable is 4025 used. 4026 4027o If both the SROM and the environment contain a MAC address, and 4028 both addresses are the same, this MAC address is used. 4029 4030o If both the SROM and the environment contain a MAC address, and the 4031 addresses differ, the value from the environment is used and a 4032 warning is printed. 4033 4034o If neither SROM nor the environment contain a MAC address, an error 4035 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4036 a random, locally-assigned MAC is used. 4037 4038If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4039will be programmed into hardware as part of the initialization process. This 4040may be skipped by setting the appropriate 'ethmacskip' environment variable. 4041The naming convention is as follows: 4042"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4043 4044Image Formats: 4045============== 4046 4047U-Boot is capable of booting (and performing other auxiliary operations on) 4048images in two formats: 4049 4050New uImage format (FIT) 4051----------------------- 4052 4053Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4054to Flattened Device Tree). It allows the use of images with multiple 4055components (several kernels, ramdisks, etc.), with contents protected by 4056SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4057 4058 4059Old uImage format 4060----------------- 4061 4062Old image format is based on binary files which can be basically anything, 4063preceded by a special header; see the definitions in include/image.h for 4064details; basically, the header defines the following image properties: 4065 4066* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4067 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4068 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4069 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4070 INTEGRITY). 4071* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4072 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4073 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4074* Compression Type (uncompressed, gzip, bzip2) 4075* Load Address 4076* Entry Point 4077* Image Name 4078* Image Timestamp 4079 4080The header is marked by a special Magic Number, and both the header 4081and the data portions of the image are secured against corruption by 4082CRC32 checksums. 4083 4084 4085Linux Support: 4086============== 4087 4088Although U-Boot should support any OS or standalone application 4089easily, the main focus has always been on Linux during the design of 4090U-Boot. 4091 4092U-Boot includes many features that so far have been part of some 4093special "boot loader" code within the Linux kernel. Also, any 4094"initrd" images to be used are no longer part of one big Linux image; 4095instead, kernel and "initrd" are separate images. This implementation 4096serves several purposes: 4097 4098- the same features can be used for other OS or standalone 4099 applications (for instance: using compressed images to reduce the 4100 Flash memory footprint) 4101 4102- it becomes much easier to port new Linux kernel versions because 4103 lots of low-level, hardware dependent stuff are done by U-Boot 4104 4105- the same Linux kernel image can now be used with different "initrd" 4106 images; of course this also means that different kernel images can 4107 be run with the same "initrd". This makes testing easier (you don't 4108 have to build a new "zImage.initrd" Linux image when you just 4109 change a file in your "initrd"). Also, a field-upgrade of the 4110 software is easier now. 4111 4112 4113Linux HOWTO: 4114============ 4115 4116Porting Linux to U-Boot based systems: 4117--------------------------------------- 4118 4119U-Boot cannot save you from doing all the necessary modifications to 4120configure the Linux device drivers for use with your target hardware 4121(no, we don't intend to provide a full virtual machine interface to 4122Linux :-). 4123 4124But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4125 4126Just make sure your machine specific header file (for instance 4127include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4128Information structure as we define in include/asm-<arch>/u-boot.h, 4129and make sure that your definition of IMAP_ADDR uses the same value 4130as your U-Boot configuration in CONFIG_SYS_IMMR. 4131 4132Note that U-Boot now has a driver model, a unified model for drivers. 4133If you are adding a new driver, plumb it into driver model. If there 4134is no uclass available, you are encouraged to create one. See 4135doc/driver-model. 4136 4137 4138Configuring the Linux kernel: 4139----------------------------- 4140 4141No specific requirements for U-Boot. Make sure you have some root 4142device (initial ramdisk, NFS) for your target system. 4143 4144 4145Building a Linux Image: 4146----------------------- 4147 4148With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4149not used. If you use recent kernel source, a new build target 4150"uImage" will exist which automatically builds an image usable by 4151U-Boot. Most older kernels also have support for a "pImage" target, 4152which was introduced for our predecessor project PPCBoot and uses a 4153100% compatible format. 4154 4155Example: 4156 4157 make TQM850L_defconfig 4158 make oldconfig 4159 make dep 4160 make uImage 4161 4162The "uImage" build target uses a special tool (in 'tools/mkimage') to 4163encapsulate a compressed Linux kernel image with header information, 4164CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4165 4166* build a standard "vmlinux" kernel image (in ELF binary format): 4167 4168* convert the kernel into a raw binary image: 4169 4170 ${CROSS_COMPILE}-objcopy -O binary \ 4171 -R .note -R .comment \ 4172 -S vmlinux linux.bin 4173 4174* compress the binary image: 4175 4176 gzip -9 linux.bin 4177 4178* package compressed binary image for U-Boot: 4179 4180 mkimage -A ppc -O linux -T kernel -C gzip \ 4181 -a 0 -e 0 -n "Linux Kernel Image" \ 4182 -d linux.bin.gz uImage 4183 4184 4185The "mkimage" tool can also be used to create ramdisk images for use 4186with U-Boot, either separated from the Linux kernel image, or 4187combined into one file. "mkimage" encapsulates the images with a 64 4188byte header containing information about target architecture, 4189operating system, image type, compression method, entry points, time 4190stamp, CRC32 checksums, etc. 4191 4192"mkimage" can be called in two ways: to verify existing images and 4193print the header information, or to build new images. 4194 4195In the first form (with "-l" option) mkimage lists the information 4196contained in the header of an existing U-Boot image; this includes 4197checksum verification: 4198 4199 tools/mkimage -l image 4200 -l ==> list image header information 4201 4202The second form (with "-d" option) is used to build a U-Boot image 4203from a "data file" which is used as image payload: 4204 4205 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4206 -n name -d data_file image 4207 -A ==> set architecture to 'arch' 4208 -O ==> set operating system to 'os' 4209 -T ==> set image type to 'type' 4210 -C ==> set compression type 'comp' 4211 -a ==> set load address to 'addr' (hex) 4212 -e ==> set entry point to 'ep' (hex) 4213 -n ==> set image name to 'name' 4214 -d ==> use image data from 'datafile' 4215 4216Right now, all Linux kernels for PowerPC systems use the same load 4217address (0x00000000), but the entry point address depends on the 4218kernel version: 4219 4220- 2.2.x kernels have the entry point at 0x0000000C, 4221- 2.3.x and later kernels have the entry point at 0x00000000. 4222 4223So a typical call to build a U-Boot image would read: 4224 4225 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4226 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4227 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4228 > examples/uImage.TQM850L 4229 Image Name: 2.4.4 kernel for TQM850L 4230 Created: Wed Jul 19 02:34:59 2000 4231 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4232 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4233 Load Address: 0x00000000 4234 Entry Point: 0x00000000 4235 4236To verify the contents of the image (or check for corruption): 4237 4238 -> tools/mkimage -l examples/uImage.TQM850L 4239 Image Name: 2.4.4 kernel for TQM850L 4240 Created: Wed Jul 19 02:34:59 2000 4241 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4242 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4243 Load Address: 0x00000000 4244 Entry Point: 0x00000000 4245 4246NOTE: for embedded systems where boot time is critical you can trade 4247speed for memory and install an UNCOMPRESSED image instead: this 4248needs more space in Flash, but boots much faster since it does not 4249need to be uncompressed: 4250 4251 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4252 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4253 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4254 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4255 > examples/uImage.TQM850L-uncompressed 4256 Image Name: 2.4.4 kernel for TQM850L 4257 Created: Wed Jul 19 02:34:59 2000 4258 Image Type: PowerPC Linux Kernel Image (uncompressed) 4259 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4260 Load Address: 0x00000000 4261 Entry Point: 0x00000000 4262 4263 4264Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4265when your kernel is intended to use an initial ramdisk: 4266 4267 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4268 > -A ppc -O linux -T ramdisk -C gzip \ 4269 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4270 Image Name: Simple Ramdisk Image 4271 Created: Wed Jan 12 14:01:50 2000 4272 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4273 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4274 Load Address: 0x00000000 4275 Entry Point: 0x00000000 4276 4277The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4278option performs the converse operation of the mkimage's second form (the "-d" 4279option). Given an image built by mkimage, the dumpimage extracts a "data file" 4280from the image: 4281 4282 tools/dumpimage -i image -T type -p position data_file 4283 -i ==> extract from the 'image' a specific 'data_file' 4284 -T ==> set image type to 'type' 4285 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4286 4287 4288Installing a Linux Image: 4289------------------------- 4290 4291To downloading a U-Boot image over the serial (console) interface, 4292you must convert the image to S-Record format: 4293 4294 objcopy -I binary -O srec examples/image examples/image.srec 4295 4296The 'objcopy' does not understand the information in the U-Boot 4297image header, so the resulting S-Record file will be relative to 4298address 0x00000000. To load it to a given address, you need to 4299specify the target address as 'offset' parameter with the 'loads' 4300command. 4301 4302Example: install the image to address 0x40100000 (which on the 4303TQM8xxL is in the first Flash bank): 4304 4305 => erase 40100000 401FFFFF 4306 4307 .......... done 4308 Erased 8 sectors 4309 4310 => loads 40100000 4311 ## Ready for S-Record download ... 4312 ~>examples/image.srec 4313 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4314 ... 4315 15989 15990 15991 15992 4316 [file transfer complete] 4317 [connected] 4318 ## Start Addr = 0x00000000 4319 4320 4321You can check the success of the download using the 'iminfo' command; 4322this includes a checksum verification so you can be sure no data 4323corruption happened: 4324 4325 => imi 40100000 4326 4327 ## Checking Image at 40100000 ... 4328 Image Name: 2.2.13 for initrd on TQM850L 4329 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4330 Data Size: 335725 Bytes = 327 kB = 0 MB 4331 Load Address: 00000000 4332 Entry Point: 0000000c 4333 Verifying Checksum ... OK 4334 4335 4336Boot Linux: 4337----------- 4338 4339The "bootm" command is used to boot an application that is stored in 4340memory (RAM or Flash). In case of a Linux kernel image, the contents 4341of the "bootargs" environment variable is passed to the kernel as 4342parameters. You can check and modify this variable using the 4343"printenv" and "setenv" commands: 4344 4345 4346 => printenv bootargs 4347 bootargs=root=/dev/ram 4348 4349 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4350 4351 => printenv bootargs 4352 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4353 4354 => bootm 40020000 4355 ## Booting Linux kernel at 40020000 ... 4356 Image Name: 2.2.13 for NFS on TQM850L 4357 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4358 Data Size: 381681 Bytes = 372 kB = 0 MB 4359 Load Address: 00000000 4360 Entry Point: 0000000c 4361 Verifying Checksum ... OK 4362 Uncompressing Kernel Image ... OK 4363 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 4364 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4365 time_init: decrementer frequency = 187500000/60 4366 Calibrating delay loop... 49.77 BogoMIPS 4367 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4368 ... 4369 4370If you want to boot a Linux kernel with initial RAM disk, you pass 4371the memory addresses of both the kernel and the initrd image (PPBCOOT 4372format!) to the "bootm" command: 4373 4374 => imi 40100000 40200000 4375 4376 ## Checking Image at 40100000 ... 4377 Image Name: 2.2.13 for initrd on TQM850L 4378 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4379 Data Size: 335725 Bytes = 327 kB = 0 MB 4380 Load Address: 00000000 4381 Entry Point: 0000000c 4382 Verifying Checksum ... OK 4383 4384 ## Checking Image at 40200000 ... 4385 Image Name: Simple Ramdisk Image 4386 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4387 Data Size: 566530 Bytes = 553 kB = 0 MB 4388 Load Address: 00000000 4389 Entry Point: 00000000 4390 Verifying Checksum ... OK 4391 4392 => bootm 40100000 40200000 4393 ## Booting Linux kernel at 40100000 ... 4394 Image Name: 2.2.13 for initrd on TQM850L 4395 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4396 Data Size: 335725 Bytes = 327 kB = 0 MB 4397 Load Address: 00000000 4398 Entry Point: 0000000c 4399 Verifying Checksum ... OK 4400 Uncompressing Kernel Image ... OK 4401 ## Loading RAMDisk Image at 40200000 ... 4402 Image Name: Simple Ramdisk Image 4403 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4404 Data Size: 566530 Bytes = 553 kB = 0 MB 4405 Load Address: 00000000 4406 Entry Point: 00000000 4407 Verifying Checksum ... OK 4408 Loading Ramdisk ... OK 4409 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 4410 Boot arguments: root=/dev/ram 4411 time_init: decrementer frequency = 187500000/60 4412 Calibrating delay loop... 49.77 BogoMIPS 4413 ... 4414 RAMDISK: Compressed image found at block 0 4415 VFS: Mounted root (ext2 filesystem). 4416 4417 bash# 4418 4419Boot Linux and pass a flat device tree: 4420----------- 4421 4422First, U-Boot must be compiled with the appropriate defines. See the section 4423titled "Linux Kernel Interface" above for a more in depth explanation. The 4424following is an example of how to start a kernel and pass an updated 4425flat device tree: 4426 4427=> print oftaddr 4428oftaddr=0x300000 4429=> print oft 4430oft=oftrees/mpc8540ads.dtb 4431=> tftp $oftaddr $oft 4432Speed: 1000, full duplex 4433Using TSEC0 device 4434TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4435Filename 'oftrees/mpc8540ads.dtb'. 4436Load address: 0x300000 4437Loading: # 4438done 4439Bytes transferred = 4106 (100a hex) 4440=> tftp $loadaddr $bootfile 4441Speed: 1000, full duplex 4442Using TSEC0 device 4443TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4444Filename 'uImage'. 4445Load address: 0x200000 4446Loading:############ 4447done 4448Bytes transferred = 1029407 (fb51f hex) 4449=> print loadaddr 4450loadaddr=200000 4451=> print oftaddr 4452oftaddr=0x300000 4453=> bootm $loadaddr - $oftaddr 4454## Booting image at 00200000 ... 4455 Image Name: Linux-2.6.17-dirty 4456 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4457 Data Size: 1029343 Bytes = 1005.2 kB 4458 Load Address: 00000000 4459 Entry Point: 00000000 4460 Verifying Checksum ... OK 4461 Uncompressing Kernel Image ... OK 4462Booting using flat device tree at 0x300000 4463Using MPC85xx ADS machine description 4464Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4465[snip] 4466 4467 4468More About U-Boot Image Types: 4469------------------------------ 4470 4471U-Boot supports the following image types: 4472 4473 "Standalone Programs" are directly runnable in the environment 4474 provided by U-Boot; it is expected that (if they behave 4475 well) you can continue to work in U-Boot after return from 4476 the Standalone Program. 4477 "OS Kernel Images" are usually images of some Embedded OS which 4478 will take over control completely. Usually these programs 4479 will install their own set of exception handlers, device 4480 drivers, set up the MMU, etc. - this means, that you cannot 4481 expect to re-enter U-Boot except by resetting the CPU. 4482 "RAMDisk Images" are more or less just data blocks, and their 4483 parameters (address, size) are passed to an OS kernel that is 4484 being started. 4485 "Multi-File Images" contain several images, typically an OS 4486 (Linux) kernel image and one or more data images like 4487 RAMDisks. This construct is useful for instance when you want 4488 to boot over the network using BOOTP etc., where the boot 4489 server provides just a single image file, but you want to get 4490 for instance an OS kernel and a RAMDisk image. 4491 4492 "Multi-File Images" start with a list of image sizes, each 4493 image size (in bytes) specified by an "uint32_t" in network 4494 byte order. This list is terminated by an "(uint32_t)0". 4495 Immediately after the terminating 0 follow the images, one by 4496 one, all aligned on "uint32_t" boundaries (size rounded up to 4497 a multiple of 4 bytes). 4498 4499 "Firmware Images" are binary images containing firmware (like 4500 U-Boot or FPGA images) which usually will be programmed to 4501 flash memory. 4502 4503 "Script files" are command sequences that will be executed by 4504 U-Boot's command interpreter; this feature is especially 4505 useful when you configure U-Boot to use a real shell (hush) 4506 as command interpreter. 4507 4508Booting the Linux zImage: 4509------------------------- 4510 4511On some platforms, it's possible to boot Linux zImage. This is done 4512using the "bootz" command. The syntax of "bootz" command is the same 4513as the syntax of "bootm" command. 4514 4515Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4516kernel with raw initrd images. The syntax is slightly different, the 4517address of the initrd must be augmented by it's size, in the following 4518format: "<initrd addres>:<initrd size>". 4519 4520 4521Standalone HOWTO: 4522================= 4523 4524One of the features of U-Boot is that you can dynamically load and 4525run "standalone" applications, which can use some resources of 4526U-Boot like console I/O functions or interrupt services. 4527 4528Two simple examples are included with the sources: 4529 4530"Hello World" Demo: 4531------------------- 4532 4533'examples/hello_world.c' contains a small "Hello World" Demo 4534application; it is automatically compiled when you build U-Boot. 4535It's configured to run at address 0x00040004, so you can play with it 4536like that: 4537 4538 => loads 4539 ## Ready for S-Record download ... 4540 ~>examples/hello_world.srec 4541 1 2 3 4 5 6 7 8 9 10 11 ... 4542 [file transfer complete] 4543 [connected] 4544 ## Start Addr = 0x00040004 4545 4546 => go 40004 Hello World! This is a test. 4547 ## Starting application at 0x00040004 ... 4548 Hello World 4549 argc = 7 4550 argv[0] = "40004" 4551 argv[1] = "Hello" 4552 argv[2] = "World!" 4553 argv[3] = "This" 4554 argv[4] = "is" 4555 argv[5] = "a" 4556 argv[6] = "test." 4557 argv[7] = "<NULL>" 4558 Hit any key to exit ... 4559 4560 ## Application terminated, rc = 0x0 4561 4562Another example, which demonstrates how to register a CPM interrupt 4563handler with the U-Boot code, can be found in 'examples/timer.c'. 4564Here, a CPM timer is set up to generate an interrupt every second. 4565The interrupt service routine is trivial, just printing a '.' 4566character, but this is just a demo program. The application can be 4567controlled by the following keys: 4568 4569 ? - print current values og the CPM Timer registers 4570 b - enable interrupts and start timer 4571 e - stop timer and disable interrupts 4572 q - quit application 4573 4574 => loads 4575 ## Ready for S-Record download ... 4576 ~>examples/timer.srec 4577 1 2 3 4 5 6 7 8 9 10 11 ... 4578 [file transfer complete] 4579 [connected] 4580 ## Start Addr = 0x00040004 4581 4582 => go 40004 4583 ## Starting application at 0x00040004 ... 4584 TIMERS=0xfff00980 4585 Using timer 1 4586 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4587 4588Hit 'b': 4589 [q, b, e, ?] Set interval 1000000 us 4590 Enabling timer 4591Hit '?': 4592 [q, b, e, ?] ........ 4593 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4594Hit '?': 4595 [q, b, e, ?] . 4596 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4597Hit '?': 4598 [q, b, e, ?] . 4599 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4600Hit '?': 4601 [q, b, e, ?] . 4602 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4603Hit 'e': 4604 [q, b, e, ?] ...Stopping timer 4605Hit 'q': 4606 [q, b, e, ?] ## Application terminated, rc = 0x0 4607 4608 4609Minicom warning: 4610================ 4611 4612Over time, many people have reported problems when trying to use the 4613"minicom" terminal emulation program for serial download. I (wd) 4614consider minicom to be broken, and recommend not to use it. Under 4615Unix, I recommend to use C-Kermit for general purpose use (and 4616especially for kermit binary protocol download ("loadb" command), and 4617use "cu" for S-Record download ("loads" command). See 4618http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4619for help with kermit. 4620 4621 4622Nevertheless, if you absolutely want to use it try adding this 4623configuration to your "File transfer protocols" section: 4624 4625 Name Program Name U/D FullScr IO-Red. Multi 4626 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4627 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4628 4629 4630NetBSD Notes: 4631============= 4632 4633Starting at version 0.9.2, U-Boot supports NetBSD both as host 4634(build U-Boot) and target system (boots NetBSD/mpc8xx). 4635 4636Building requires a cross environment; it is known to work on 4637NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4638need gmake since the Makefiles are not compatible with BSD make). 4639Note that the cross-powerpc package does not install include files; 4640attempting to build U-Boot will fail because <machine/ansi.h> is 4641missing. This file has to be installed and patched manually: 4642 4643 # cd /usr/pkg/cross/powerpc-netbsd/include 4644 # mkdir powerpc 4645 # ln -s powerpc machine 4646 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4647 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4648 4649Native builds *don't* work due to incompatibilities between native 4650and U-Boot include files. 4651 4652Booting assumes that (the first part of) the image booted is a 4653stage-2 loader which in turn loads and then invokes the kernel 4654proper. Loader sources will eventually appear in the NetBSD source 4655tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4656meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4657 4658 4659Implementation Internals: 4660========================= 4661 4662The following is not intended to be a complete description of every 4663implementation detail. However, it should help to understand the 4664inner workings of U-Boot and make it easier to port it to custom 4665hardware. 4666 4667 4668Initial Stack, Global Data: 4669--------------------------- 4670 4671The implementation of U-Boot is complicated by the fact that U-Boot 4672starts running out of ROM (flash memory), usually without access to 4673system RAM (because the memory controller is not initialized yet). 4674This means that we don't have writable Data or BSS segments, and BSS 4675is not initialized as zero. To be able to get a C environment working 4676at all, we have to allocate at least a minimal stack. Implementation 4677options for this are defined and restricted by the CPU used: Some CPU 4678models provide on-chip memory (like the IMMR area on MPC8xx and 4679MPC826x processors), on others (parts of) the data cache can be 4680locked as (mis-) used as memory, etc. 4681 4682 Chris Hallinan posted a good summary of these issues to the 4683 U-Boot mailing list: 4684 4685 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4686 From: "Chris Hallinan" <clh@net1plus.com> 4687 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4688 ... 4689 4690 Correct me if I'm wrong, folks, but the way I understand it 4691 is this: Using DCACHE as initial RAM for Stack, etc, does not 4692 require any physical RAM backing up the cache. The cleverness 4693 is that the cache is being used as a temporary supply of 4694 necessary storage before the SDRAM controller is setup. It's 4695 beyond the scope of this list to explain the details, but you 4696 can see how this works by studying the cache architecture and 4697 operation in the architecture and processor-specific manuals. 4698 4699 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4700 is another option for the system designer to use as an 4701 initial stack/RAM area prior to SDRAM being available. Either 4702 option should work for you. Using CS 4 should be fine if your 4703 board designers haven't used it for something that would 4704 cause you grief during the initial boot! It is frequently not 4705 used. 4706 4707 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4708 with your processor/board/system design. The default value 4709 you will find in any recent u-boot distribution in 4710 walnut.h should work for you. I'd set it to a value larger 4711 than your SDRAM module. If you have a 64MB SDRAM module, set 4712 it above 400_0000. Just make sure your board has no resources 4713 that are supposed to respond to that address! That code in 4714 start.S has been around a while and should work as is when 4715 you get the config right. 4716 4717 -Chris Hallinan 4718 DS4.COM, Inc. 4719 4720It is essential to remember this, since it has some impact on the C 4721code for the initialization procedures: 4722 4723* Initialized global data (data segment) is read-only. Do not attempt 4724 to write it. 4725 4726* Do not use any uninitialized global data (or implicitly initialized 4727 as zero data - BSS segment) at all - this is undefined, initiali- 4728 zation is performed later (when relocating to RAM). 4729 4730* Stack space is very limited. Avoid big data buffers or things like 4731 that. 4732 4733Having only the stack as writable memory limits means we cannot use 4734normal global data to share information between the code. But it 4735turned out that the implementation of U-Boot can be greatly 4736simplified by making a global data structure (gd_t) available to all 4737functions. We could pass a pointer to this data as argument to _all_ 4738functions, but this would bloat the code. Instead we use a feature of 4739the GCC compiler (Global Register Variables) to share the data: we 4740place a pointer (gd) to the global data into a register which we 4741reserve for this purpose. 4742 4743When choosing a register for such a purpose we are restricted by the 4744relevant (E)ABI specifications for the current architecture, and by 4745GCC's implementation. 4746 4747For PowerPC, the following registers have specific use: 4748 R1: stack pointer 4749 R2: reserved for system use 4750 R3-R4: parameter passing and return values 4751 R5-R10: parameter passing 4752 R13: small data area pointer 4753 R30: GOT pointer 4754 R31: frame pointer 4755 4756 (U-Boot also uses R12 as internal GOT pointer. r12 4757 is a volatile register so r12 needs to be reset when 4758 going back and forth between asm and C) 4759 4760 ==> U-Boot will use R2 to hold a pointer to the global data 4761 4762 Note: on PPC, we could use a static initializer (since the 4763 address of the global data structure is known at compile time), 4764 but it turned out that reserving a register results in somewhat 4765 smaller code - although the code savings are not that big (on 4766 average for all boards 752 bytes for the whole U-Boot image, 4767 624 text + 127 data). 4768 4769On ARM, the following registers are used: 4770 4771 R0: function argument word/integer result 4772 R1-R3: function argument word 4773 R9: platform specific 4774 R10: stack limit (used only if stack checking is enabled) 4775 R11: argument (frame) pointer 4776 R12: temporary workspace 4777 R13: stack pointer 4778 R14: link register 4779 R15: program counter 4780 4781 ==> U-Boot will use R9 to hold a pointer to the global data 4782 4783 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4784 4785On Nios II, the ABI is documented here: 4786 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4787 4788 ==> U-Boot will use gp to hold a pointer to the global data 4789 4790 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4791 to access small data sections, so gp is free. 4792 4793On NDS32, the following registers are used: 4794 4795 R0-R1: argument/return 4796 R2-R5: argument 4797 R15: temporary register for assembler 4798 R16: trampoline register 4799 R28: frame pointer (FP) 4800 R29: global pointer (GP) 4801 R30: link register (LP) 4802 R31: stack pointer (SP) 4803 PC: program counter (PC) 4804 4805 ==> U-Boot will use R10 to hold a pointer to the global data 4806 4807NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4808or current versions of GCC may "optimize" the code too much. 4809 4810On RISC-V, the following registers are used: 4811 4812 x0: hard-wired zero (zero) 4813 x1: return address (ra) 4814 x2: stack pointer (sp) 4815 x3: global pointer (gp) 4816 x4: thread pointer (tp) 4817 x5: link register (t0) 4818 x8: frame pointer (fp) 4819 x10-x11: arguments/return values (a0-1) 4820 x12-x17: arguments (a2-7) 4821 x28-31: temporaries (t3-6) 4822 pc: program counter (pc) 4823 4824 ==> U-Boot will use gp to hold a pointer to the global data 4825 4826Memory Management: 4827------------------ 4828 4829U-Boot runs in system state and uses physical addresses, i.e. the 4830MMU is not used either for address mapping nor for memory protection. 4831 4832The available memory is mapped to fixed addresses using the memory 4833controller. In this process, a contiguous block is formed for each 4834memory type (Flash, SDRAM, SRAM), even when it consists of several 4835physical memory banks. 4836 4837U-Boot is installed in the first 128 kB of the first Flash bank (on 4838TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4839booting and sizing and initializing DRAM, the code relocates itself 4840to the upper end of DRAM. Immediately below the U-Boot code some 4841memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4842configuration setting]. Below that, a structure with global Board 4843Info data is placed, followed by the stack (growing downward). 4844 4845Additionally, some exception handler code is copied to the low 8 kB 4846of DRAM (0x00000000 ... 0x00001FFF). 4847 4848So a typical memory configuration with 16 MB of DRAM could look like 4849this: 4850 4851 0x0000 0000 Exception Vector code 4852 : 4853 0x0000 1FFF 4854 0x0000 2000 Free for Application Use 4855 : 4856 : 4857 4858 : 4859 : 4860 0x00FB FF20 Monitor Stack (Growing downward) 4861 0x00FB FFAC Board Info Data and permanent copy of global data 4862 0x00FC 0000 Malloc Arena 4863 : 4864 0x00FD FFFF 4865 0x00FE 0000 RAM Copy of Monitor Code 4866 ... eventually: LCD or video framebuffer 4867 ... eventually: pRAM (Protected RAM - unchanged by reset) 4868 0x00FF FFFF [End of RAM] 4869 4870 4871System Initialization: 4872---------------------- 4873 4874In the reset configuration, U-Boot starts at the reset entry point 4875(on most PowerPC systems at address 0x00000100). Because of the reset 4876configuration for CS0# this is a mirror of the on board Flash memory. 4877To be able to re-map memory U-Boot then jumps to its link address. 4878To be able to implement the initialization code in C, a (small!) 4879initial stack is set up in the internal Dual Ported RAM (in case CPUs 4880which provide such a feature like), or in a locked part of the data 4881cache. After that, U-Boot initializes the CPU core, the caches and 4882the SIU. 4883 4884Next, all (potentially) available memory banks are mapped using a 4885preliminary mapping. For example, we put them on 512 MB boundaries 4886(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4887on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4888programmed for SDRAM access. Using the temporary configuration, a 4889simple memory test is run that determines the size of the SDRAM 4890banks. 4891 4892When there is more than one SDRAM bank, and the banks are of 4893different size, the largest is mapped first. For equal size, the first 4894bank (CS2#) is mapped first. The first mapping is always for address 48950x00000000, with any additional banks following immediately to create 4896contiguous memory starting from 0. 4897 4898Then, the monitor installs itself at the upper end of the SDRAM area 4899and allocates memory for use by malloc() and for the global Board 4900Info data; also, the exception vector code is copied to the low RAM 4901pages, and the final stack is set up. 4902 4903Only after this relocation will you have a "normal" C environment; 4904until that you are restricted in several ways, mostly because you are 4905running from ROM, and because the code will have to be relocated to a 4906new address in RAM. 4907 4908 4909U-Boot Porting Guide: 4910---------------------- 4911 4912[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4913list, October 2002] 4914 4915 4916int main(int argc, char *argv[]) 4917{ 4918 sighandler_t no_more_time; 4919 4920 signal(SIGALRM, no_more_time); 4921 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4922 4923 if (available_money > available_manpower) { 4924 Pay consultant to port U-Boot; 4925 return 0; 4926 } 4927 4928 Download latest U-Boot source; 4929 4930 Subscribe to u-boot mailing list; 4931 4932 if (clueless) 4933 email("Hi, I am new to U-Boot, how do I get started?"); 4934 4935 while (learning) { 4936 Read the README file in the top level directory; 4937 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4938 Read applicable doc/*.README; 4939 Read the source, Luke; 4940 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4941 } 4942 4943 if (available_money > toLocalCurrency ($2500)) 4944 Buy a BDI3000; 4945 else 4946 Add a lot of aggravation and time; 4947 4948 if (a similar board exists) { /* hopefully... */ 4949 cp -a board/<similar> board/<myboard> 4950 cp include/configs/<similar>.h include/configs/<myboard>.h 4951 } else { 4952 Create your own board support subdirectory; 4953 Create your own board include/configs/<myboard>.h file; 4954 } 4955 Edit new board/<myboard> files 4956 Edit new include/configs/<myboard>.h 4957 4958 while (!accepted) { 4959 while (!running) { 4960 do { 4961 Add / modify source code; 4962 } until (compiles); 4963 Debug; 4964 if (clueless) 4965 email("Hi, I am having problems..."); 4966 } 4967 Send patch file to the U-Boot email list; 4968 if (reasonable critiques) 4969 Incorporate improvements from email list code review; 4970 else 4971 Defend code as written; 4972 } 4973 4974 return 0; 4975} 4976 4977void no_more_time (int sig) 4978{ 4979 hire_a_guru(); 4980} 4981 4982 4983Coding Standards: 4984----------------- 4985 4986All contributions to U-Boot should conform to the Linux kernel 4987coding style; see the kernel coding style guide at 4988https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 4989script "scripts/Lindent" in your Linux kernel source directory. 4990 4991Source files originating from a different project (for example the 4992MTD subsystem) are generally exempt from these guidelines and are not 4993reformatted to ease subsequent migration to newer versions of those 4994sources. 4995 4996Please note that U-Boot is implemented in C (and to some small parts in 4997Assembler); no C++ is used, so please do not use C++ style comments (//) 4998in your code. 4999 5000Please also stick to the following formatting rules: 5001- remove any trailing white space 5002- use TAB characters for indentation and vertical alignment, not spaces 5003- make sure NOT to use DOS '\r\n' line feeds 5004- do not add more than 2 consecutive empty lines to source files 5005- do not add trailing empty lines to source files 5006 5007Submissions which do not conform to the standards may be returned 5008with a request to reformat the changes. 5009 5010 5011Submitting Patches: 5012------------------- 5013 5014Since the number of patches for U-Boot is growing, we need to 5015establish some rules. Submissions which do not conform to these rules 5016may be rejected, even when they contain important and valuable stuff. 5017 5018Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5019 5020Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5021see https://lists.denx.de/listinfo/u-boot 5022 5023When you send a patch, please include the following information with 5024it: 5025 5026* For bug fixes: a description of the bug and how your patch fixes 5027 this bug. Please try to include a way of demonstrating that the 5028 patch actually fixes something. 5029 5030* For new features: a description of the feature and your 5031 implementation. 5032 5033* A CHANGELOG entry as plaintext (separate from the patch) 5034 5035* For major contributions, add a MAINTAINERS file with your 5036 information and associated file and directory references. 5037 5038* When you add support for a new board, don't forget to add a 5039 maintainer e-mail address to the boards.cfg file, too. 5040 5041* If your patch adds new configuration options, don't forget to 5042 document these in the README file. 5043 5044* The patch itself. If you are using git (which is *strongly* 5045 recommended) you can easily generate the patch using the 5046 "git format-patch". If you then use "git send-email" to send it to 5047 the U-Boot mailing list, you will avoid most of the common problems 5048 with some other mail clients. 5049 5050 If you cannot use git, use "diff -purN OLD NEW". If your version of 5051 diff does not support these options, then get the latest version of 5052 GNU diff. 5053 5054 The current directory when running this command shall be the parent 5055 directory of the U-Boot source tree (i. e. please make sure that 5056 your patch includes sufficient directory information for the 5057 affected files). 5058 5059 We prefer patches as plain text. MIME attachments are discouraged, 5060 and compressed attachments must not be used. 5061 5062* If one logical set of modifications affects or creates several 5063 files, all these changes shall be submitted in a SINGLE patch file. 5064 5065* Changesets that contain different, unrelated modifications shall be 5066 submitted as SEPARATE patches, one patch per changeset. 5067 5068 5069Notes: 5070 5071* Before sending the patch, run the buildman script on your patched 5072 source tree and make sure that no errors or warnings are reported 5073 for any of the boards. 5074 5075* Keep your modifications to the necessary minimum: A patch 5076 containing several unrelated changes or arbitrary reformats will be 5077 returned with a request to re-formatting / split it. 5078 5079* If you modify existing code, make sure that your new code does not 5080 add to the memory footprint of the code ;-) Small is beautiful! 5081 When adding new features, these should compile conditionally only 5082 (using #ifdef), and the resulting code with the new feature 5083 disabled must not need more memory than the old code without your 5084 modification. 5085 5086* Remember that there is a size limit of 100 kB per message on the 5087 u-boot mailing list. Bigger patches will be moderated. If they are 5088 reasonable and not too big, they will be acknowledged. But patches 5089 bigger than the size limit should be avoided. 5090