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- 85xx CPU Options: 335 CONFIG_SYS_PPC64 336 337 Specifies that the core is a 64-bit PowerPC implementation (implements 338 the "64" category of the Power ISA). This is necessary for ePAPR 339 compliance, among other possible reasons. 340 341 CONFIG_SYS_FSL_TBCLK_DIV 342 343 Defines the core time base clock divider ratio compared to the 344 system clock. On most PQ3 devices this is 8, on newer QorIQ 345 devices it can be 16 or 32. The ratio varies from SoC to Soc. 346 347 CONFIG_SYS_FSL_PCIE_COMPAT 348 349 Defines the string to utilize when trying to match PCIe device 350 tree nodes for the given platform. 351 352 CONFIG_SYS_FSL_ERRATUM_A004510 353 354 Enables a workaround for erratum A004510. If set, 355 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 356 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 357 358 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 359 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 360 361 Defines one or two SoC revisions (low 8 bits of SVR) 362 for which the A004510 workaround should be applied. 363 364 The rest of SVR is either not relevant to the decision 365 of whether the erratum is present (e.g. p2040 versus 366 p2041) or is implied by the build target, which controls 367 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 368 369 See Freescale App Note 4493 for more information about 370 this erratum. 371 372 CONFIG_A003399_NOR_WORKAROUND 373 Enables a workaround for IFC erratum A003399. It is only 374 required during NOR boot. 375 376 CONFIG_A008044_WORKAROUND 377 Enables a workaround for T1040/T1042 erratum A008044. It is only 378 required during NAND boot and valid for Rev 1.0 SoC revision 379 380 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 381 382 This is the value to write into CCSR offset 0x18600 383 according to the A004510 workaround. 384 385 CONFIG_SYS_FSL_DSP_DDR_ADDR 386 This value denotes start offset of DDR memory which is 387 connected exclusively to the DSP cores. 388 389 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 390 This value denotes start offset of M2 memory 391 which is directly connected to the DSP core. 392 393 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 394 This value denotes start offset of M3 memory which is directly 395 connected to the DSP core. 396 397 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 398 This value denotes start offset of DSP CCSR space. 399 400 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 401 Single Source Clock is clocking mode present in some of FSL SoC's. 402 In this mode, a single differential clock is used to supply 403 clocks to the sysclock, ddrclock and usbclock. 404 405 CONFIG_SYS_CPC_REINIT_F 406 This CONFIG is defined when the CPC is configured as SRAM at the 407 time of U-Boot entry and is required to be re-initialized. 408 409 CONFIG_DEEP_SLEEP 410 Indicates this SoC supports deep sleep feature. If deep sleep is 411 supported, core will start to execute uboot when wakes up. 412 413- Generic CPU options: 414 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 415 416 Defines the endianess of the CPU. Implementation of those 417 values is arch specific. 418 419 CONFIG_SYS_FSL_DDR 420 Freescale DDR driver in use. This type of DDR controller is 421 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 422 SoCs. 423 424 CONFIG_SYS_FSL_DDR_ADDR 425 Freescale DDR memory-mapped register base. 426 427 CONFIG_SYS_FSL_DDR_EMU 428 Specify emulator support for DDR. Some DDR features such as 429 deskew training are not available. 430 431 CONFIG_SYS_FSL_DDRC_GEN1 432 Freescale DDR1 controller. 433 434 CONFIG_SYS_FSL_DDRC_GEN2 435 Freescale DDR2 controller. 436 437 CONFIG_SYS_FSL_DDRC_GEN3 438 Freescale DDR3 controller. 439 440 CONFIG_SYS_FSL_DDRC_GEN4 441 Freescale DDR4 controller. 442 443 CONFIG_SYS_FSL_DDRC_ARM_GEN3 444 Freescale DDR3 controller for ARM-based SoCs. 445 446 CONFIG_SYS_FSL_DDR1 447 Board config to use DDR1. It can be enabled for SoCs with 448 Freescale DDR1 or DDR2 controllers, depending on the board 449 implemetation. 450 451 CONFIG_SYS_FSL_DDR2 452 Board config to use DDR2. It can be enabled for SoCs with 453 Freescale DDR2 or DDR3 controllers, depending on the board 454 implementation. 455 456 CONFIG_SYS_FSL_DDR3 457 Board config to use DDR3. It can be enabled for SoCs with 458 Freescale DDR3 or DDR3L controllers. 459 460 CONFIG_SYS_FSL_DDR3L 461 Board config to use DDR3L. It can be enabled for SoCs with 462 DDR3L controllers. 463 464 CONFIG_SYS_FSL_DDR4 465 Board config to use DDR4. It can be enabled for SoCs with 466 DDR4 controllers. 467 468 CONFIG_SYS_FSL_IFC_BE 469 Defines the IFC controller register space as Big Endian 470 471 CONFIG_SYS_FSL_IFC_LE 472 Defines the IFC controller register space as Little Endian 473 474 CONFIG_SYS_FSL_IFC_CLK_DIV 475 Defines divider of platform clock(clock input to IFC controller). 476 477 CONFIG_SYS_FSL_LBC_CLK_DIV 478 Defines divider of platform clock(clock input to eLBC controller). 479 480 CONFIG_SYS_FSL_PBL_PBI 481 It enables addition of RCW (Power on reset configuration) in built image. 482 Please refer doc/README.pblimage for more details 483 484 CONFIG_SYS_FSL_PBL_RCW 485 It adds PBI(pre-boot instructions) commands in u-boot build image. 486 PBI commands can be used to configure SoC before it starts the execution. 487 Please refer doc/README.pblimage for more details 488 489 CONFIG_SPL_FSL_PBL 490 It adds a target to create boot binary having SPL binary in PBI format 491 concatenated with u-boot binary. 492 493 CONFIG_SYS_FSL_DDR_BE 494 Defines the DDR controller register space as Big Endian 495 496 CONFIG_SYS_FSL_DDR_LE 497 Defines the DDR controller register space as Little Endian 498 499 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 500 Physical address from the view of DDR controllers. It is the 501 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 502 it could be different for ARM SoCs. 503 504 CONFIG_SYS_FSL_DDR_INTLV_256B 505 DDR controller interleaving on 256-byte. This is a special 506 interleaving mode, handled by Dickens for Freescale layerscape 507 SoCs with ARM core. 508 509 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 510 Number of controllers used as main memory. 511 512 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 513 Number of controllers used for other than main memory. 514 515 CONFIG_SYS_FSL_HAS_DP_DDR 516 Defines the SoC has DP-DDR used for DPAA. 517 518 CONFIG_SYS_FSL_SEC_BE 519 Defines the SEC controller register space as Big Endian 520 521 CONFIG_SYS_FSL_SEC_LE 522 Defines the SEC controller register space as Little Endian 523 524- MIPS CPU options: 525 CONFIG_SYS_INIT_SP_OFFSET 526 527 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 528 pointer. This is needed for the temporary stack before 529 relocation. 530 531 CONFIG_SYS_MIPS_CACHE_MODE 532 533 Cache operation mode for the MIPS CPU. 534 See also arch/mips/include/asm/mipsregs.h. 535 Possible values are: 536 CONF_CM_CACHABLE_NO_WA 537 CONF_CM_CACHABLE_WA 538 CONF_CM_UNCACHED 539 CONF_CM_CACHABLE_NONCOHERENT 540 CONF_CM_CACHABLE_CE 541 CONF_CM_CACHABLE_COW 542 CONF_CM_CACHABLE_CUW 543 CONF_CM_CACHABLE_ACCELERATED 544 545 CONFIG_SYS_XWAY_EBU_BOOTCFG 546 547 Special option for Lantiq XWAY SoCs for booting from NOR flash. 548 See also arch/mips/cpu/mips32/start.S. 549 550 CONFIG_XWAY_SWAP_BYTES 551 552 Enable compilation of tools/xway-swap-bytes needed for Lantiq 553 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 554 be swapped if a flash programmer is used. 555 556- ARM options: 557 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 558 559 Select high exception vectors of the ARM core, e.g., do not 560 clear the V bit of the c1 register of CP15. 561 562 COUNTER_FREQUENCY 563 Generic timer clock source frequency. 564 565 COUNTER_FREQUENCY_REAL 566 Generic timer clock source frequency if the real clock is 567 different from COUNTER_FREQUENCY, and can only be determined 568 at run time. 569 570- Tegra SoC options: 571 CONFIG_TEGRA_SUPPORT_NON_SECURE 572 573 Support executing U-Boot in non-secure (NS) mode. Certain 574 impossible actions will be skipped if the CPU is in NS mode, 575 such as ARM architectural timer initialization. 576 577- Linux Kernel Interface: 578 CONFIG_CLOCKS_IN_MHZ 579 580 U-Boot stores all clock information in Hz 581 internally. For binary compatibility with older Linux 582 kernels (which expect the clocks passed in the 583 bd_info data to be in MHz) the environment variable 584 "clocks_in_mhz" can be defined so that U-Boot 585 converts clock data to MHZ before passing it to the 586 Linux kernel. 587 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 588 "clocks_in_mhz=1" is automatically included in the 589 default environment. 590 591 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 592 593 When transferring memsize parameter to Linux, some versions 594 expect it to be in bytes, others in MB. 595 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 596 597 CONFIG_OF_LIBFDT 598 599 New kernel versions are expecting firmware settings to be 600 passed using flattened device trees (based on open firmware 601 concepts). 602 603 CONFIG_OF_LIBFDT 604 * New libfdt-based support 605 * Adds the "fdt" command 606 * The bootm command automatically updates the fdt 607 608 OF_TBCLK - The timebase frequency. 609 OF_STDOUT_PATH - The path to the console device 610 611 boards with QUICC Engines require OF_QE to set UCC MAC 612 addresses 613 614 CONFIG_OF_BOARD_SETUP 615 616 Board code has addition modification that it wants to make 617 to the flat device tree before handing it off to the kernel 618 619 CONFIG_OF_SYSTEM_SETUP 620 621 Other code has addition modification that it wants to make 622 to the flat device tree before handing it off to the kernel. 623 This causes ft_system_setup() to be called before booting 624 the kernel. 625 626 CONFIG_OF_IDE_FIXUP 627 628 U-Boot can detect if an IDE device is present or not. 629 If not, and this new config option is activated, U-Boot 630 removes the ATA node from the DTS before booting Linux, 631 so the Linux IDE driver does not probe the device and 632 crash. This is needed for buggy hardware (uc101) where 633 no pull down resistor is connected to the signal IDE5V_DD7. 634 635 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 636 637 This setting is mandatory for all boards that have only one 638 machine type and must be used to specify the machine type 639 number as it appears in the ARM machine registry 640 (see http://www.arm.linux.org.uk/developer/machines/). 641 Only boards that have multiple machine types supported 642 in a single configuration file and the machine type is 643 runtime discoverable, do not have to use this setting. 644 645- vxWorks boot parameters: 646 647 bootvx constructs a valid bootline using the following 648 environments variables: bootdev, bootfile, ipaddr, netmask, 649 serverip, gatewayip, hostname, othbootargs. 650 It loads the vxWorks image pointed bootfile. 651 652 Note: If a "bootargs" environment is defined, it will overwride 653 the defaults discussed just above. 654 655- Cache Configuration: 656 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 657 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 658 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 659 660- Cache Configuration for ARM: 661 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 662 controller 663 CONFIG_SYS_PL310_BASE - Physical base address of PL310 664 controller register space 665 666- Serial Ports: 667 CONFIG_PL010_SERIAL 668 669 Define this if you want support for Amba PrimeCell PL010 UARTs. 670 671 CONFIG_PL011_SERIAL 672 673 Define this if you want support for Amba PrimeCell PL011 UARTs. 674 675 CONFIG_PL011_CLOCK 676 677 If you have Amba PrimeCell PL011 UARTs, set this variable to 678 the clock speed of the UARTs. 679 680 CONFIG_PL01x_PORTS 681 682 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 683 define this to a list of base addresses for each (supported) 684 port. See e.g. include/configs/versatile.h 685 686 CONFIG_SERIAL_HW_FLOW_CONTROL 687 688 Define this variable to enable hw flow control in serial driver. 689 Current user of this option is drivers/serial/nsl16550.c driver 690 691- Console Baudrate: 692 CONFIG_BAUDRATE - in bps 693 Select one of the baudrates listed in 694 CONFIG_SYS_BAUDRATE_TABLE, see below. 695 696- Autoboot Command: 697 CONFIG_BOOTCOMMAND 698 Only needed when CONFIG_BOOTDELAY is enabled; 699 define a command string that is automatically executed 700 when no character is read on the console interface 701 within "Boot Delay" after reset. 702 703 CONFIG_RAMBOOT and CONFIG_NFSBOOT 704 The value of these goes into the environment as 705 "ramboot" and "nfsboot" respectively, and can be used 706 as a convenience, when switching between booting from 707 RAM and NFS. 708 709- Pre-Boot Commands: 710 CONFIG_PREBOOT 711 712 When this option is #defined, the existence of the 713 environment variable "preboot" will be checked 714 immediately before starting the CONFIG_BOOTDELAY 715 countdown and/or running the auto-boot command resp. 716 entering interactive mode. 717 718 This feature is especially useful when "preboot" is 719 automatically generated or modified. For an example 720 see the LWMON board specific code: here "preboot" is 721 modified when the user holds down a certain 722 combination of keys on the (special) keyboard when 723 booting the systems 724 725- Serial Download Echo Mode: 726 CONFIG_LOADS_ECHO 727 If defined to 1, all characters received during a 728 serial download (using the "loads" command) are 729 echoed back. This might be needed by some terminal 730 emulations (like "cu"), but may as well just take 731 time on others. This setting #define's the initial 732 value of the "loads_echo" environment variable. 733 734- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 735 CONFIG_KGDB_BAUDRATE 736 Select one of the baudrates listed in 737 CONFIG_SYS_BAUDRATE_TABLE, see below. 738 739- Removal of commands 740 If no commands are needed to boot, you can disable 741 CONFIG_CMDLINE to remove them. In this case, the command line 742 will not be available, and when U-Boot wants to execute the 743 boot command (on start-up) it will call board_run_command() 744 instead. This can reduce image size significantly for very 745 simple boot procedures. 746 747- Regular expression support: 748 CONFIG_REGEX 749 If this variable is defined, U-Boot is linked against 750 the SLRE (Super Light Regular Expression) library, 751 which adds regex support to some commands, as for 752 example "env grep" and "setexpr". 753 754- Device tree: 755 CONFIG_OF_CONTROL 756 If this variable is defined, U-Boot will use a device tree 757 to configure its devices, instead of relying on statically 758 compiled #defines in the board file. This option is 759 experimental and only available on a few boards. The device 760 tree is available in the global data as gd->fdt_blob. 761 762 U-Boot needs to get its device tree from somewhere. This can 763 be done using one of the three options below: 764 765 CONFIG_OF_EMBED 766 If this variable is defined, U-Boot will embed a device tree 767 binary in its image. This device tree file should be in the 768 board directory and called <soc>-<board>.dts. The binary file 769 is then picked up in board_init_f() and made available through 770 the global data structure as gd->fdt_blob. 771 772 CONFIG_OF_SEPARATE 773 If this variable is defined, U-Boot will build a device tree 774 binary. It will be called u-boot.dtb. Architecture-specific 775 code will locate it at run-time. Generally this works by: 776 777 cat u-boot.bin u-boot.dtb >image.bin 778 779 and in fact, U-Boot does this for you, creating a file called 780 u-boot-dtb.bin which is useful in the common case. You can 781 still use the individual files if you need something more 782 exotic. 783 784 CONFIG_OF_BOARD 785 If this variable is defined, U-Boot will use the device tree 786 provided by the board at runtime instead of embedding one with 787 the image. Only boards defining board_fdt_blob_setup() support 788 this option (see include/fdtdec.h file). 789 790- Watchdog: 791 CONFIG_WATCHDOG 792 If this variable is defined, it enables watchdog 793 support for the SoC. There must be support in the SoC 794 specific code for a watchdog. For the 8xx 795 CPUs, the SIU Watchdog feature is enabled in the SYPCR 796 register. When supported for a specific SoC is 797 available, then no further board specific code should 798 be needed to use it. 799 800 CONFIG_HW_WATCHDOG 801 When using a watchdog circuitry external to the used 802 SoC, then define this variable and provide board 803 specific code for the "hw_watchdog_reset" function. 804 805 CONFIG_AT91_HW_WDT_TIMEOUT 806 specify the timeout in seconds. default 2 seconds. 807 808- Real-Time Clock: 809 810 When CONFIG_CMD_DATE is selected, the type of the RTC 811 has to be selected, too. Define exactly one of the 812 following options: 813 814 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 815 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 816 CONFIG_RTC_MC146818 - use MC146818 RTC 817 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 818 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 819 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 820 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 821 CONFIG_RTC_DS164x - use Dallas DS164x RTC 822 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 823 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 824 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 825 CONFIG_SYS_RV3029_TCR - enable trickle charger on 826 RV3029 RTC. 827 828 Note that if the RTC uses I2C, then the I2C interface 829 must also be configured. See I2C Support, below. 830 831- GPIO Support: 832 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 833 834 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 835 chip-ngpio pairs that tell the PCA953X driver the number of 836 pins supported by a particular chip. 837 838 Note that if the GPIO device uses I2C, then the I2C interface 839 must also be configured. See I2C Support, below. 840 841- I/O tracing: 842 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 843 accesses and can checksum them or write a list of them out 844 to memory. See the 'iotrace' command for details. This is 845 useful for testing device drivers since it can confirm that 846 the driver behaves the same way before and after a code 847 change. Currently this is supported on sandbox and arm. To 848 add support for your architecture, add '#include <iotrace.h>' 849 to the bottom of arch/<arch>/include/asm/io.h and test. 850 851 Example output from the 'iotrace stats' command is below. 852 Note that if the trace buffer is exhausted, the checksum will 853 still continue to operate. 854 855 iotrace is enabled 856 Start: 10000000 (buffer start address) 857 Size: 00010000 (buffer size) 858 Offset: 00000120 (current buffer offset) 859 Output: 10000120 (start + offset) 860 Count: 00000018 (number of trace records) 861 CRC32: 9526fb66 (CRC32 of all trace records) 862 863- Timestamp Support: 864 865 When CONFIG_TIMESTAMP is selected, the timestamp 866 (date and time) of an image is printed by image 867 commands like bootm or iminfo. This option is 868 automatically enabled when you select CONFIG_CMD_DATE . 869 870- Partition Labels (disklabels) Supported: 871 Zero or more of the following: 872 CONFIG_MAC_PARTITION Apple's MacOS partition table. 873 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 874 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 875 bootloader. Note 2TB partition limit; see 876 disk/part_efi.c 877 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 878 879 If IDE or SCSI support is enabled (CONFIG_IDE or 880 CONFIG_SCSI) you must configure support for at 881 least one non-MTD partition type as well. 882 883- IDE Reset method: 884 CONFIG_IDE_RESET_ROUTINE - this is defined in several 885 board configurations files but used nowhere! 886 887 CONFIG_IDE_RESET - is this is defined, IDE Reset will 888 be performed by calling the function 889 ide_set_reset(int reset) 890 which has to be defined in a board specific file 891 892- ATAPI Support: 893 CONFIG_ATAPI 894 895 Set this to enable ATAPI support. 896 897- LBA48 Support 898 CONFIG_LBA48 899 900 Set this to enable support for disks larger than 137GB 901 Also look at CONFIG_SYS_64BIT_LBA. 902 Whithout these , LBA48 support uses 32bit variables and will 'only' 903 support disks up to 2.1TB. 904 905 CONFIG_SYS_64BIT_LBA: 906 When enabled, makes the IDE subsystem use 64bit sector addresses. 907 Default is 32bit. 908 909- SCSI Support: 910 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 911 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 912 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 913 maximum numbers of LUNs, SCSI ID's and target 914 devices. 915 916 The environment variable 'scsidevs' is set to the number of 917 SCSI devices found during the last scan. 918 919- NETWORK Support (PCI): 920 CONFIG_E1000 921 Support for Intel 8254x/8257x gigabit chips. 922 923 CONFIG_E1000_SPI 924 Utility code for direct access to the SPI bus on Intel 8257x. 925 This does not do anything useful unless you set at least one 926 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 927 928 CONFIG_E1000_SPI_GENERIC 929 Allow generic access to the SPI bus on the Intel 8257x, for 930 example with the "sspi" command. 931 932 CONFIG_EEPRO100 933 Support for Intel 82557/82559/82559ER chips. 934 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 935 write routine for first time initialisation. 936 937 CONFIG_TULIP 938 Support for Digital 2114x chips. 939 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 940 modem chip initialisation (KS8761/QS6611). 941 942 CONFIG_NATSEMI 943 Support for National dp83815 chips. 944 945 CONFIG_NS8382X 946 Support for National dp8382[01] gigabit chips. 947 948- NETWORK Support (other): 949 950 CONFIG_DRIVER_AT91EMAC 951 Support for AT91RM9200 EMAC. 952 953 CONFIG_RMII 954 Define this to use reduced MII inteface 955 956 CONFIG_DRIVER_AT91EMAC_QUIET 957 If this defined, the driver is quiet. 958 The driver doen't show link status messages. 959 960 CONFIG_CALXEDA_XGMAC 961 Support for the Calxeda XGMAC device 962 963 CONFIG_LAN91C96 964 Support for SMSC's LAN91C96 chips. 965 966 CONFIG_LAN91C96_USE_32_BIT 967 Define this to enable 32 bit addressing 968 969 CONFIG_SMC91111 970 Support for SMSC's LAN91C111 chip 971 972 CONFIG_SMC91111_BASE 973 Define this to hold the physical address 974 of the device (I/O space) 975 976 CONFIG_SMC_USE_32_BIT 977 Define this if data bus is 32 bits 978 979 CONFIG_SMC_USE_IOFUNCS 980 Define this to use i/o functions instead of macros 981 (some hardware wont work with macros) 982 983 CONFIG_DRIVER_TI_EMAC 984 Support for davinci emac 985 986 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 987 Define this if you have more then 3 PHYs. 988 989 CONFIG_FTGMAC100 990 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 991 992 CONFIG_FTGMAC100_EGIGA 993 Define this to use GE link update with gigabit PHY. 994 Define this if FTGMAC100 is connected to gigabit PHY. 995 If your system has 10/100 PHY only, it might not occur 996 wrong behavior. Because PHY usually return timeout or 997 useless data when polling gigabit status and gigabit 998 control registers. This behavior won't affect the 999 correctnessof 10/100 link speed update. 1000 1001 CONFIG_SH_ETHER 1002 Support for Renesas on-chip Ethernet controller 1003 1004 CONFIG_SH_ETHER_USE_PORT 1005 Define the number of ports to be used 1006 1007 CONFIG_SH_ETHER_PHY_ADDR 1008 Define the ETH PHY's address 1009 1010 CONFIG_SH_ETHER_CACHE_WRITEBACK 1011 If this option is set, the driver enables cache flush. 1012 1013- PWM Support: 1014 CONFIG_PWM_IMX 1015 Support for PWM module on the imx6. 1016 1017- TPM Support: 1018 CONFIG_TPM 1019 Support TPM devices. 1020 1021 CONFIG_TPM_TIS_INFINEON 1022 Support for Infineon i2c bus TPM devices. Only one device 1023 per system is supported at this time. 1024 1025 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1026 Define the burst count bytes upper limit 1027 1028 CONFIG_TPM_ST33ZP24 1029 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1030 1031 CONFIG_TPM_ST33ZP24_I2C 1032 Support for STMicroelectronics ST33ZP24 I2C devices. 1033 Requires TPM_ST33ZP24 and I2C. 1034 1035 CONFIG_TPM_ST33ZP24_SPI 1036 Support for STMicroelectronics ST33ZP24 SPI devices. 1037 Requires TPM_ST33ZP24 and SPI. 1038 1039 CONFIG_TPM_ATMEL_TWI 1040 Support for Atmel TWI TPM device. Requires I2C support. 1041 1042 CONFIG_TPM_TIS_LPC 1043 Support for generic parallel port TPM devices. Only one device 1044 per system is supported at this time. 1045 1046 CONFIG_TPM_TIS_BASE_ADDRESS 1047 Base address where the generic TPM device is mapped 1048 to. Contemporary x86 systems usually map it at 1049 0xfed40000. 1050 1051 CONFIG_TPM 1052 Define this to enable the TPM support library which provides 1053 functional interfaces to some TPM commands. 1054 Requires support for a TPM device. 1055 1056 CONFIG_TPM_AUTH_SESSIONS 1057 Define this to enable authorized functions in the TPM library. 1058 Requires CONFIG_TPM and CONFIG_SHA1. 1059 1060- USB Support: 1061 At the moment only the UHCI host controller is 1062 supported (PIP405, MIP405); define 1063 CONFIG_USB_UHCI to enable it. 1064 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1065 and define CONFIG_USB_STORAGE to enable the USB 1066 storage devices. 1067 Note: 1068 Supported are USB Keyboards and USB Floppy drives 1069 (TEAC FD-05PUB). 1070 1071 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1072 txfilltuning field in the EHCI controller on reset. 1073 1074 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1075 HW module registers. 1076 1077- USB Device: 1078 Define the below if you wish to use the USB console. 1079 Once firmware is rebuilt from a serial console issue the 1080 command "setenv stdin usbtty; setenv stdout usbtty" and 1081 attach your USB cable. The Unix command "dmesg" should print 1082 it has found a new device. The environment variable usbtty 1083 can be set to gserial or cdc_acm to enable your device to 1084 appear to a USB host as a Linux gserial device or a 1085 Common Device Class Abstract Control Model serial device. 1086 If you select usbtty = gserial you should be able to enumerate 1087 a Linux host by 1088 # modprobe usbserial vendor=0xVendorID product=0xProductID 1089 else if using cdc_acm, simply setting the environment 1090 variable usbtty to be cdc_acm should suffice. The following 1091 might be defined in YourBoardName.h 1092 1093 CONFIG_USB_DEVICE 1094 Define this to build a UDC device 1095 1096 CONFIG_USB_TTY 1097 Define this to have a tty type of device available to 1098 talk to the UDC device 1099 1100 CONFIG_USBD_HS 1101 Define this to enable the high speed support for usb 1102 device and usbtty. If this feature is enabled, a routine 1103 int is_usbd_high_speed(void) 1104 also needs to be defined by the driver to dynamically poll 1105 whether the enumeration has succeded at high speed or full 1106 speed. 1107 1108 CONFIG_SYS_CONSOLE_IS_IN_ENV 1109 Define this if you want stdin, stdout &/or stderr to 1110 be set to usbtty. 1111 1112 If you have a USB-IF assigned VendorID then you may wish to 1113 define your own vendor specific values either in BoardName.h 1114 or directly in usbd_vendor_info.h. If you don't define 1115 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1116 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1117 should pretend to be a Linux device to it's target host. 1118 1119 CONFIG_USBD_MANUFACTURER 1120 Define this string as the name of your company for 1121 - CONFIG_USBD_MANUFACTURER "my company" 1122 1123 CONFIG_USBD_PRODUCT_NAME 1124 Define this string as the name of your product 1125 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1126 1127 CONFIG_USBD_VENDORID 1128 Define this as your assigned Vendor ID from the USB 1129 Implementors Forum. This *must* be a genuine Vendor ID 1130 to avoid polluting the USB namespace. 1131 - CONFIG_USBD_VENDORID 0xFFFF 1132 1133 CONFIG_USBD_PRODUCTID 1134 Define this as the unique Product ID 1135 for your device 1136 - CONFIG_USBD_PRODUCTID 0xFFFF 1137 1138- ULPI Layer Support: 1139 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1140 the generic ULPI layer. The generic layer accesses the ULPI PHY 1141 via the platform viewport, so you need both the genric layer and 1142 the viewport enabled. Currently only Chipidea/ARC based 1143 viewport is supported. 1144 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1145 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1146 If your ULPI phy needs a different reference clock than the 1147 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1148 the appropriate value in Hz. 1149 1150- MMC Support: 1151 The MMC controller on the Intel PXA is supported. To 1152 enable this define CONFIG_MMC. The MMC can be 1153 accessed from the boot prompt by mapping the device 1154 to physical memory similar to flash. Command line is 1155 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1156 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1157 1158 CONFIG_SH_MMCIF 1159 Support for Renesas on-chip MMCIF controller 1160 1161 CONFIG_SH_MMCIF_ADDR 1162 Define the base address of MMCIF registers 1163 1164 CONFIG_SH_MMCIF_CLK 1165 Define the clock frequency for MMCIF 1166 1167 CONFIG_SUPPORT_EMMC_BOOT 1168 Enable some additional features of the eMMC boot partitions. 1169 1170- USB Device Firmware Update (DFU) class support: 1171 CONFIG_DFU_OVER_USB 1172 This enables the USB portion of the DFU USB class 1173 1174 CONFIG_DFU_MMC 1175 This enables support for exposing (e)MMC devices via DFU. 1176 1177 CONFIG_DFU_NAND 1178 This enables support for exposing NAND devices via DFU. 1179 1180 CONFIG_DFU_RAM 1181 This enables support for exposing RAM via DFU. 1182 Note: DFU spec refer to non-volatile memory usage, but 1183 allow usages beyond the scope of spec - here RAM usage, 1184 one that would help mostly the developer. 1185 1186 CONFIG_SYS_DFU_DATA_BUF_SIZE 1187 Dfu transfer uses a buffer before writing data to the 1188 raw storage device. Make the size (in bytes) of this buffer 1189 configurable. The size of this buffer is also configurable 1190 through the "dfu_bufsiz" environment variable. 1191 1192 CONFIG_SYS_DFU_MAX_FILE_SIZE 1193 When updating files rather than the raw storage device, 1194 we use a static buffer to copy the file into and then write 1195 the buffer once we've been given the whole file. Define 1196 this to the maximum filesize (in bytes) for the buffer. 1197 Default is 4 MiB if undefined. 1198 1199 DFU_DEFAULT_POLL_TIMEOUT 1200 Poll timeout [ms], is the timeout a device can send to the 1201 host. The host must wait for this timeout before sending 1202 a subsequent DFU_GET_STATUS request to the device. 1203 1204 DFU_MANIFEST_POLL_TIMEOUT 1205 Poll timeout [ms], which the device sends to the host when 1206 entering dfuMANIFEST state. Host waits this timeout, before 1207 sending again an USB request to the device. 1208 1209- Journaling Flash filesystem support: 1210 CONFIG_JFFS2_NAND 1211 Define these for a default partition on a NAND device 1212 1213 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1214 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1215 Define these for a default partition on a NOR device 1216 1217- Keyboard Support: 1218 See Kconfig help for available keyboard drivers. 1219 1220 CONFIG_KEYBOARD 1221 1222 Define this to enable a custom keyboard support. 1223 This simply calls drv_keyboard_init() which must be 1224 defined in your board-specific files. This option is deprecated 1225 and is only used by novena. For new boards, use driver model 1226 instead. 1227 1228- Video support: 1229 CONFIG_FSL_DIU_FB 1230 Enable the Freescale DIU video driver. Reference boards for 1231 SOCs that have a DIU should define this macro to enable DIU 1232 support, and should also define these other macros: 1233 1234 CONFIG_SYS_DIU_ADDR 1235 CONFIG_VIDEO 1236 CONFIG_CFB_CONSOLE 1237 CONFIG_VIDEO_SW_CURSOR 1238 CONFIG_VGA_AS_SINGLE_DEVICE 1239 CONFIG_VIDEO_LOGO 1240 CONFIG_VIDEO_BMP_LOGO 1241 1242 The DIU driver will look for the 'video-mode' environment 1243 variable, and if defined, enable the DIU as a console during 1244 boot. See the documentation file doc/README.video for a 1245 description of this variable. 1246 1247- LCD Support: CONFIG_LCD 1248 1249 Define this to enable LCD support (for output to LCD 1250 display); also select one of the supported displays 1251 by defining one of these: 1252 1253 CONFIG_ATMEL_LCD: 1254 1255 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1256 1257 CONFIG_NEC_NL6448AC33: 1258 1259 NEC NL6448AC33-18. Active, color, single scan. 1260 1261 CONFIG_NEC_NL6448BC20 1262 1263 NEC NL6448BC20-08. 6.5", 640x480. 1264 Active, color, single scan. 1265 1266 CONFIG_NEC_NL6448BC33_54 1267 1268 NEC NL6448BC33-54. 10.4", 640x480. 1269 Active, color, single scan. 1270 1271 CONFIG_SHARP_16x9 1272 1273 Sharp 320x240. Active, color, single scan. 1274 It isn't 16x9, and I am not sure what it is. 1275 1276 CONFIG_SHARP_LQ64D341 1277 1278 Sharp LQ64D341 display, 640x480. 1279 Active, color, single scan. 1280 1281 CONFIG_HLD1045 1282 1283 HLD1045 display, 640x480. 1284 Active, color, single scan. 1285 1286 CONFIG_OPTREX_BW 1287 1288 Optrex CBL50840-2 NF-FW 99 22 M5 1289 or 1290 Hitachi LMG6912RPFC-00T 1291 or 1292 Hitachi SP14Q002 1293 1294 320x240. Black & white. 1295 1296 CONFIG_LCD_ALIGNMENT 1297 1298 Normally the LCD is page-aligned (typically 4KB). If this is 1299 defined then the LCD will be aligned to this value instead. 1300 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1301 here, since it is cheaper to change data cache settings on 1302 a per-section basis. 1303 1304 1305 CONFIG_LCD_ROTATION 1306 1307 Sometimes, for example if the display is mounted in portrait 1308 mode or even if it's mounted landscape but rotated by 180degree, 1309 we need to rotate our content of the display relative to the 1310 framebuffer, so that user can read the messages which are 1311 printed out. 1312 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1313 initialized with a given rotation from "vl_rot" out of 1314 "vidinfo_t" which is provided by the board specific code. 1315 The value for vl_rot is coded as following (matching to 1316 fbcon=rotate:<n> linux-kernel commandline): 1317 0 = no rotation respectively 0 degree 1318 1 = 90 degree rotation 1319 2 = 180 degree rotation 1320 3 = 270 degree rotation 1321 1322 If CONFIG_LCD_ROTATION is not defined, the console will be 1323 initialized with 0degree rotation. 1324 1325 CONFIG_LCD_BMP_RLE8 1326 1327 Support drawing of RLE8-compressed bitmaps on the LCD. 1328 1329 CONFIG_I2C_EDID 1330 1331 Enables an 'i2c edid' command which can read EDID 1332 information over I2C from an attached LCD display. 1333 1334- Splash Screen Support: CONFIG_SPLASH_SCREEN 1335 1336 If this option is set, the environment is checked for 1337 a variable "splashimage". If found, the usual display 1338 of logo, copyright and system information on the LCD 1339 is suppressed and the BMP image at the address 1340 specified in "splashimage" is loaded instead. The 1341 console is redirected to the "nulldev", too. This 1342 allows for a "silent" boot where a splash screen is 1343 loaded very quickly after power-on. 1344 1345 CONFIG_SPLASHIMAGE_GUARD 1346 1347 If this option is set, then U-Boot will prevent the environment 1348 variable "splashimage" from being set to a problematic address 1349 (see doc/README.displaying-bmps). 1350 This option is useful for targets where, due to alignment 1351 restrictions, an improperly aligned BMP image will cause a data 1352 abort. If you think you will not have problems with unaligned 1353 accesses (for example because your toolchain prevents them) 1354 there is no need to set this option. 1355 1356 CONFIG_SPLASH_SCREEN_ALIGN 1357 1358 If this option is set the splash image can be freely positioned 1359 on the screen. Environment variable "splashpos" specifies the 1360 position as "x,y". If a positive number is given it is used as 1361 number of pixel from left/top. If a negative number is given it 1362 is used as number of pixel from right/bottom. You can also 1363 specify 'm' for centering the image. 1364 1365 Example: 1366 setenv splashpos m,m 1367 => image at center of screen 1368 1369 setenv splashpos 30,20 1370 => image at x = 30 and y = 20 1371 1372 setenv splashpos -10,m 1373 => vertically centered image 1374 at x = dspWidth - bmpWidth - 9 1375 1376- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1377 1378 If this option is set, additionally to standard BMP 1379 images, gzipped BMP images can be displayed via the 1380 splashscreen support or the bmp command. 1381 1382- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1383 1384 If this option is set, 8-bit RLE compressed BMP images 1385 can be displayed via the splashscreen support or the 1386 bmp command. 1387 1388- Compression support: 1389 CONFIG_GZIP 1390 1391 Enabled by default to support gzip compressed images. 1392 1393 CONFIG_BZIP2 1394 1395 If this option is set, support for bzip2 compressed 1396 images is included. If not, only uncompressed and gzip 1397 compressed images are supported. 1398 1399 NOTE: the bzip2 algorithm requires a lot of RAM, so 1400 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1401 be at least 4MB. 1402 1403- MII/PHY support: 1404 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1405 1406 The clock frequency of the MII bus 1407 1408 CONFIG_PHY_RESET_DELAY 1409 1410 Some PHY like Intel LXT971A need extra delay after 1411 reset before any MII register access is possible. 1412 For such PHY, set this option to the usec delay 1413 required. (minimum 300usec for LXT971A) 1414 1415 CONFIG_PHY_CMD_DELAY (ppc4xx) 1416 1417 Some PHY like Intel LXT971A need extra delay after 1418 command issued before MII status register can be read 1419 1420- IP address: 1421 CONFIG_IPADDR 1422 1423 Define a default value for the IP address to use for 1424 the default Ethernet interface, in case this is not 1425 determined through e.g. bootp. 1426 (Environment variable "ipaddr") 1427 1428- Server IP address: 1429 CONFIG_SERVERIP 1430 1431 Defines a default value for the IP address of a TFTP 1432 server to contact when using the "tftboot" command. 1433 (Environment variable "serverip") 1434 1435 CONFIG_KEEP_SERVERADDR 1436 1437 Keeps the server's MAC address, in the env 'serveraddr' 1438 for passing to bootargs (like Linux's netconsole option) 1439 1440- Gateway IP address: 1441 CONFIG_GATEWAYIP 1442 1443 Defines a default value for the IP address of the 1444 default router where packets to other networks are 1445 sent to. 1446 (Environment variable "gatewayip") 1447 1448- Subnet mask: 1449 CONFIG_NETMASK 1450 1451 Defines a default value for the subnet mask (or 1452 routing prefix) which is used to determine if an IP 1453 address belongs to the local subnet or needs to be 1454 forwarded through a router. 1455 (Environment variable "netmask") 1456 1457- Multicast TFTP Mode: 1458 CONFIG_MCAST_TFTP 1459 1460 Defines whether you want to support multicast TFTP as per 1461 rfc-2090; for example to work with atftp. Lets lots of targets 1462 tftp down the same boot image concurrently. Note: the Ethernet 1463 driver in use must provide a function: mcast() to join/leave a 1464 multicast group. 1465 1466- BOOTP Recovery Mode: 1467 CONFIG_BOOTP_RANDOM_DELAY 1468 1469 If you have many targets in a network that try to 1470 boot using BOOTP, you may want to avoid that all 1471 systems send out BOOTP requests at precisely the same 1472 moment (which would happen for instance at recovery 1473 from a power failure, when all systems will try to 1474 boot, thus flooding the BOOTP server. Defining 1475 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1476 inserted before sending out BOOTP requests. The 1477 following delays are inserted then: 1478 1479 1st BOOTP request: delay 0 ... 1 sec 1480 2nd BOOTP request: delay 0 ... 2 sec 1481 3rd BOOTP request: delay 0 ... 4 sec 1482 4th and following 1483 BOOTP requests: delay 0 ... 8 sec 1484 1485 CONFIG_BOOTP_ID_CACHE_SIZE 1486 1487 BOOTP packets are uniquely identified using a 32-bit ID. The 1488 server will copy the ID from client requests to responses and 1489 U-Boot will use this to determine if it is the destination of 1490 an incoming response. Some servers will check that addresses 1491 aren't in use before handing them out (usually using an ARP 1492 ping) and therefore take up to a few hundred milliseconds to 1493 respond. Network congestion may also influence the time it 1494 takes for a response to make it back to the client. If that 1495 time is too long, U-Boot will retransmit requests. In order 1496 to allow earlier responses to still be accepted after these 1497 retransmissions, U-Boot's BOOTP client keeps a small cache of 1498 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1499 cache. The default is to keep IDs for up to four outstanding 1500 requests. Increasing this will allow U-Boot to accept offers 1501 from a BOOTP client in networks with unusually high latency. 1502 1503- DHCP Advanced Options: 1504 You can fine tune the DHCP functionality by defining 1505 CONFIG_BOOTP_* symbols: 1506 1507 CONFIG_BOOTP_NISDOMAIN 1508 CONFIG_BOOTP_BOOTFILESIZE 1509 CONFIG_BOOTP_SEND_HOSTNAME 1510 CONFIG_BOOTP_NTPSERVER 1511 CONFIG_BOOTP_TIMEOFFSET 1512 CONFIG_BOOTP_VENDOREX 1513 CONFIG_BOOTP_MAY_FAIL 1514 1515 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1516 environment variable, not the BOOTP server. 1517 1518 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1519 after the configured retry count, the call will fail 1520 instead of starting over. This can be used to fail over 1521 to Link-local IP address configuration if the DHCP server 1522 is not available. 1523 1524 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1525 to do a dynamic update of a DNS server. To do this, they 1526 need the hostname of the DHCP requester. 1527 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1528 of the "hostname" environment variable is passed as 1529 option 12 to the DHCP server. 1530 1531 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1532 1533 A 32bit value in microseconds for a delay between 1534 receiving a "DHCP Offer" and sending the "DHCP Request". 1535 This fixes a problem with certain DHCP servers that don't 1536 respond 100% of the time to a "DHCP request". E.g. On an 1537 AT91RM9200 processor running at 180MHz, this delay needed 1538 to be *at least* 15,000 usec before a Windows Server 2003 1539 DHCP server would reply 100% of the time. I recommend at 1540 least 50,000 usec to be safe. The alternative is to hope 1541 that one of the retries will be successful but note that 1542 the DHCP timeout and retry process takes a longer than 1543 this delay. 1544 1545 - Link-local IP address negotiation: 1546 Negotiate with other link-local clients on the local network 1547 for an address that doesn't require explicit configuration. 1548 This is especially useful if a DHCP server cannot be guaranteed 1549 to exist in all environments that the device must operate. 1550 1551 See doc/README.link-local for more information. 1552 1553 - MAC address from environment variables 1554 1555 FDT_SEQ_MACADDR_FROM_ENV 1556 1557 Fix-up device tree with MAC addresses fetched sequentially from 1558 environment variables. This config work on assumption that 1559 non-usable ethernet node of device-tree are either not present 1560 or their status has been marked as "disabled". 1561 1562 - CDP Options: 1563 CONFIG_CDP_DEVICE_ID 1564 1565 The device id used in CDP trigger frames. 1566 1567 CONFIG_CDP_DEVICE_ID_PREFIX 1568 1569 A two character string which is prefixed to the MAC address 1570 of the device. 1571 1572 CONFIG_CDP_PORT_ID 1573 1574 A printf format string which contains the ascii name of 1575 the port. Normally is set to "eth%d" which sets 1576 eth0 for the first Ethernet, eth1 for the second etc. 1577 1578 CONFIG_CDP_CAPABILITIES 1579 1580 A 32bit integer which indicates the device capabilities; 1581 0x00000010 for a normal host which does not forwards. 1582 1583 CONFIG_CDP_VERSION 1584 1585 An ascii string containing the version of the software. 1586 1587 CONFIG_CDP_PLATFORM 1588 1589 An ascii string containing the name of the platform. 1590 1591 CONFIG_CDP_TRIGGER 1592 1593 A 32bit integer sent on the trigger. 1594 1595 CONFIG_CDP_POWER_CONSUMPTION 1596 1597 A 16bit integer containing the power consumption of the 1598 device in .1 of milliwatts. 1599 1600 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1601 1602 A byte containing the id of the VLAN. 1603 1604- Status LED: CONFIG_LED_STATUS 1605 1606 Several configurations allow to display the current 1607 status using a LED. For instance, the LED will blink 1608 fast while running U-Boot code, stop blinking as 1609 soon as a reply to a BOOTP request was received, and 1610 start blinking slow once the Linux kernel is running 1611 (supported by a status LED driver in the Linux 1612 kernel). Defining CONFIG_LED_STATUS enables this 1613 feature in U-Boot. 1614 1615 Additional options: 1616 1617 CONFIG_LED_STATUS_GPIO 1618 The status LED can be connected to a GPIO pin. 1619 In such cases, the gpio_led driver can be used as a 1620 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1621 to include the gpio_led driver in the U-Boot binary. 1622 1623 CONFIG_GPIO_LED_INVERTED_TABLE 1624 Some GPIO connected LEDs may have inverted polarity in which 1625 case the GPIO high value corresponds to LED off state and 1626 GPIO low value corresponds to LED on state. 1627 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1628 with a list of GPIO LEDs that have inverted polarity. 1629 1630- I2C Support: CONFIG_SYS_I2C 1631 1632 This enable the NEW i2c subsystem, and will allow you to use 1633 i2c commands at the u-boot command line (as long as you set 1634 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1635 based realtime clock chips or other i2c devices. See 1636 common/cmd_i2c.c for a description of the command line 1637 interface. 1638 1639 ported i2c driver to the new framework: 1640 - drivers/i2c/soft_i2c.c: 1641 - activate first bus with CONFIG_SYS_I2C_SOFT define 1642 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1643 for defining speed and slave address 1644 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1645 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1646 for defining speed and slave address 1647 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1648 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1649 for defining speed and slave address 1650 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1651 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1652 for defining speed and slave address 1653 1654 - drivers/i2c/fsl_i2c.c: 1655 - activate i2c driver with CONFIG_SYS_I2C_FSL 1656 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1657 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1658 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1659 bus. 1660 - If your board supports a second fsl i2c bus, define 1661 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1662 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1663 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1664 second bus. 1665 1666 - drivers/i2c/tegra_i2c.c: 1667 - activate this driver with CONFIG_SYS_I2C_TEGRA 1668 - This driver adds 4 i2c buses with a fix speed from 1669 100000 and the slave addr 0! 1670 1671 - drivers/i2c/ppc4xx_i2c.c 1672 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1673 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1674 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1675 1676 - drivers/i2c/i2c_mxc.c 1677 - activate this driver with CONFIG_SYS_I2C_MXC 1678 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1679 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1680 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1681 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1682 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1683 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1684 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1685 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1686 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1687 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1688 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1689 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1690 If those defines are not set, default value is 100000 1691 for speed, and 0 for slave. 1692 1693 - drivers/i2c/rcar_i2c.c: 1694 - activate this driver with CONFIG_SYS_I2C_RCAR 1695 - This driver adds 4 i2c buses 1696 1697 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1698 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1699 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1700 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1701 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1702 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1703 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1704 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1705 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1706 1707 - drivers/i2c/sh_i2c.c: 1708 - activate this driver with CONFIG_SYS_I2C_SH 1709 - This driver adds from 2 to 5 i2c buses 1710 1711 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1712 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1713 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1714 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1715 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1716 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1717 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1718 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1719 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1720 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1721 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1722 1723 - drivers/i2c/omap24xx_i2c.c 1724 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1725 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1726 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1727 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1728 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1729 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1730 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1731 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1732 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1733 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1734 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1735 1736 - drivers/i2c/zynq_i2c.c 1737 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1738 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1739 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1740 1741 - drivers/i2c/s3c24x0_i2c.c: 1742 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1743 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1744 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1745 with a fix speed from 100000 and the slave addr 0! 1746 1747 - drivers/i2c/ihs_i2c.c 1748 - activate this driver with CONFIG_SYS_I2C_IHS 1749 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1750 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1751 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1752 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1753 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1754 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1755 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1756 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1757 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1758 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1759 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1760 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1761 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1762 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1763 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1764 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1765 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1766 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1767 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1768 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1769 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1770 1771 additional defines: 1772 1773 CONFIG_SYS_NUM_I2C_BUSES 1774 Hold the number of i2c buses you want to use. 1775 1776 CONFIG_SYS_I2C_DIRECT_BUS 1777 define this, if you don't use i2c muxes on your hardware. 1778 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1779 omit this define. 1780 1781 CONFIG_SYS_I2C_MAX_HOPS 1782 define how many muxes are maximal consecutively connected 1783 on one i2c bus. If you not use i2c muxes, omit this 1784 define. 1785 1786 CONFIG_SYS_I2C_BUSES 1787 hold a list of buses you want to use, only used if 1788 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1789 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1790 CONFIG_SYS_NUM_I2C_BUSES = 9: 1791 1792 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1793 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1794 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1795 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1796 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1797 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1798 {1, {I2C_NULL_HOP}}, \ 1799 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1800 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1801 } 1802 1803 which defines 1804 bus 0 on adapter 0 without a mux 1805 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1806 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1807 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1808 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1809 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1810 bus 6 on adapter 1 without a mux 1811 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1812 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1813 1814 If you do not have i2c muxes on your board, omit this define. 1815 1816- Legacy I2C Support: 1817 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1818 then the following macros need to be defined (examples are 1819 from include/configs/lwmon.h): 1820 1821 I2C_INIT 1822 1823 (Optional). Any commands necessary to enable the I2C 1824 controller or configure ports. 1825 1826 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1827 1828 I2C_ACTIVE 1829 1830 The code necessary to make the I2C data line active 1831 (driven). If the data line is open collector, this 1832 define can be null. 1833 1834 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1835 1836 I2C_TRISTATE 1837 1838 The code necessary to make the I2C data line tri-stated 1839 (inactive). If the data line is open collector, this 1840 define can be null. 1841 1842 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1843 1844 I2C_READ 1845 1846 Code that returns true if the I2C data line is high, 1847 false if it is low. 1848 1849 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1850 1851 I2C_SDA(bit) 1852 1853 If <bit> is true, sets the I2C data line high. If it 1854 is false, it clears it (low). 1855 1856 eg: #define I2C_SDA(bit) \ 1857 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1858 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1859 1860 I2C_SCL(bit) 1861 1862 If <bit> is true, sets the I2C clock line high. If it 1863 is false, it clears it (low). 1864 1865 eg: #define I2C_SCL(bit) \ 1866 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1867 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1868 1869 I2C_DELAY 1870 1871 This delay is invoked four times per clock cycle so this 1872 controls the rate of data transfer. The data rate thus 1873 is 1 / (I2C_DELAY * 4). Often defined to be something 1874 like: 1875 1876 #define I2C_DELAY udelay(2) 1877 1878 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1879 1880 If your arch supports the generic GPIO framework (asm/gpio.h), 1881 then you may alternatively define the two GPIOs that are to be 1882 used as SCL / SDA. Any of the previous I2C_xxx macros will 1883 have GPIO-based defaults assigned to them as appropriate. 1884 1885 You should define these to the GPIO value as given directly to 1886 the generic GPIO functions. 1887 1888 CONFIG_SYS_I2C_INIT_BOARD 1889 1890 When a board is reset during an i2c bus transfer 1891 chips might think that the current transfer is still 1892 in progress. On some boards it is possible to access 1893 the i2c SCLK line directly, either by using the 1894 processor pin as a GPIO or by having a second pin 1895 connected to the bus. If this option is defined a 1896 custom i2c_init_board() routine in boards/xxx/board.c 1897 is run early in the boot sequence. 1898 1899 CONFIG_I2C_MULTI_BUS 1900 1901 This option allows the use of multiple I2C buses, each of which 1902 must have a controller. At any point in time, only one bus is 1903 active. To switch to a different bus, use the 'i2c dev' command. 1904 Note that bus numbering is zero-based. 1905 1906 CONFIG_SYS_I2C_NOPROBES 1907 1908 This option specifies a list of I2C devices that will be skipped 1909 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1910 is set, specify a list of bus-device pairs. Otherwise, specify 1911 a 1D array of device addresses 1912 1913 e.g. 1914 #undef CONFIG_I2C_MULTI_BUS 1915 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1916 1917 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1918 1919 #define CONFIG_I2C_MULTI_BUS 1920 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1921 1922 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1923 1924 CONFIG_SYS_SPD_BUS_NUM 1925 1926 If defined, then this indicates the I2C bus number for DDR SPD. 1927 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1928 1929 CONFIG_SYS_RTC_BUS_NUM 1930 1931 If defined, then this indicates the I2C bus number for the RTC. 1932 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1933 1934 CONFIG_SOFT_I2C_READ_REPEATED_START 1935 1936 defining this will force the i2c_read() function in 1937 the soft_i2c driver to perform an I2C repeated start 1938 between writing the address pointer and reading the 1939 data. If this define is omitted the default behaviour 1940 of doing a stop-start sequence will be used. Most I2C 1941 devices can use either method, but some require one or 1942 the other. 1943 1944- SPI Support: CONFIG_SPI 1945 1946 Enables SPI driver (so far only tested with 1947 SPI EEPROM, also an instance works with Crystal A/D and 1948 D/As on the SACSng board) 1949 1950 CONFIG_SOFT_SPI 1951 1952 Enables a software (bit-bang) SPI driver rather than 1953 using hardware support. This is a general purpose 1954 driver that only requires three general I/O port pins 1955 (two outputs, one input) to function. If this is 1956 defined, the board configuration must define several 1957 SPI configuration items (port pins to use, etc). For 1958 an example, see include/configs/sacsng.h. 1959 1960 CONFIG_HARD_SPI 1961 1962 Enables a hardware SPI driver for general-purpose reads 1963 and writes. As with CONFIG_SOFT_SPI, the board configuration 1964 must define a list of chip-select function pointers. 1965 Currently supported on some MPC8xxx processors. For an 1966 example, see include/configs/mpc8349emds.h. 1967 1968 CONFIG_SYS_SPI_MXC_WAIT 1969 Timeout for waiting until spi transfer completed. 1970 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1971 1972- FPGA Support: CONFIG_FPGA 1973 1974 Enables FPGA subsystem. 1975 1976 CONFIG_FPGA_<vendor> 1977 1978 Enables support for specific chip vendors. 1979 (ALTERA, XILINX) 1980 1981 CONFIG_FPGA_<family> 1982 1983 Enables support for FPGA family. 1984 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1985 1986 CONFIG_FPGA_COUNT 1987 1988 Specify the number of FPGA devices to support. 1989 1990 CONFIG_SYS_FPGA_PROG_FEEDBACK 1991 1992 Enable printing of hash marks during FPGA configuration. 1993 1994 CONFIG_SYS_FPGA_CHECK_BUSY 1995 1996 Enable checks on FPGA configuration interface busy 1997 status by the configuration function. This option 1998 will require a board or device specific function to 1999 be written. 2000 2001 CONFIG_FPGA_DELAY 2002 2003 If defined, a function that provides delays in the FPGA 2004 configuration driver. 2005 2006 CONFIG_SYS_FPGA_CHECK_CTRLC 2007 Allow Control-C to interrupt FPGA configuration 2008 2009 CONFIG_SYS_FPGA_CHECK_ERROR 2010 2011 Check for configuration errors during FPGA bitfile 2012 loading. For example, abort during Virtex II 2013 configuration if the INIT_B line goes low (which 2014 indicated a CRC error). 2015 2016 CONFIG_SYS_FPGA_WAIT_INIT 2017 2018 Maximum time to wait for the INIT_B line to de-assert 2019 after PROB_B has been de-asserted during a Virtex II 2020 FPGA configuration sequence. The default time is 500 2021 ms. 2022 2023 CONFIG_SYS_FPGA_WAIT_BUSY 2024 2025 Maximum time to wait for BUSY to de-assert during 2026 Virtex II FPGA configuration. The default is 5 ms. 2027 2028 CONFIG_SYS_FPGA_WAIT_CONFIG 2029 2030 Time to wait after FPGA configuration. The default is 2031 200 ms. 2032 2033- Configuration Management: 2034 CONFIG_BUILD_TARGET 2035 2036 Some SoCs need special image types (e.g. U-Boot binary 2037 with a special header) as build targets. By defining 2038 CONFIG_BUILD_TARGET in the SoC / board header, this 2039 special image will be automatically built upon calling 2040 make / buildman. 2041 2042 CONFIG_IDENT_STRING 2043 2044 If defined, this string will be added to the U-Boot 2045 version information (U_BOOT_VERSION) 2046 2047- Vendor Parameter Protection: 2048 2049 U-Boot considers the values of the environment 2050 variables "serial#" (Board Serial Number) and 2051 "ethaddr" (Ethernet Address) to be parameters that 2052 are set once by the board vendor / manufacturer, and 2053 protects these variables from casual modification by 2054 the user. Once set, these variables are read-only, 2055 and write or delete attempts are rejected. You can 2056 change this behaviour: 2057 2058 If CONFIG_ENV_OVERWRITE is #defined in your config 2059 file, the write protection for vendor parameters is 2060 completely disabled. Anybody can change or delete 2061 these parameters. 2062 2063 Alternatively, if you define _both_ an ethaddr in the 2064 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2065 Ethernet address is installed in the environment, 2066 which can be changed exactly ONCE by the user. [The 2067 serial# is unaffected by this, i. e. it remains 2068 read-only.] 2069 2070 The same can be accomplished in a more flexible way 2071 for any variable by configuring the type of access 2072 to allow for those variables in the ".flags" variable 2073 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2074 2075- Protected RAM: 2076 CONFIG_PRAM 2077 2078 Define this variable to enable the reservation of 2079 "protected RAM", i. e. RAM which is not overwritten 2080 by U-Boot. Define CONFIG_PRAM to hold the number of 2081 kB you want to reserve for pRAM. You can overwrite 2082 this default value by defining an environment 2083 variable "pram" to the number of kB you want to 2084 reserve. Note that the board info structure will 2085 still show the full amount of RAM. If pRAM is 2086 reserved, a new environment variable "mem" will 2087 automatically be defined to hold the amount of 2088 remaining RAM in a form that can be passed as boot 2089 argument to Linux, for instance like that: 2090 2091 setenv bootargs ... mem=\${mem} 2092 saveenv 2093 2094 This way you can tell Linux not to use this memory, 2095 either, which results in a memory region that will 2096 not be affected by reboots. 2097 2098 *WARNING* If your board configuration uses automatic 2099 detection of the RAM size, you must make sure that 2100 this memory test is non-destructive. So far, the 2101 following board configurations are known to be 2102 "pRAM-clean": 2103 2104 IVMS8, IVML24, SPD8xx, 2105 HERMES, IP860, RPXlite, LWMON, 2106 FLAGADM 2107 2108- Access to physical memory region (> 4GB) 2109 Some basic support is provided for operations on memory not 2110 normally accessible to U-Boot - e.g. some architectures 2111 support access to more than 4GB of memory on 32-bit 2112 machines using physical address extension or similar. 2113 Define CONFIG_PHYSMEM to access this basic support, which 2114 currently only supports clearing the memory. 2115 2116- Error Recovery: 2117 CONFIG_NET_RETRY_COUNT 2118 2119 This variable defines the number of retries for 2120 network operations like ARP, RARP, TFTP, or BOOTP 2121 before giving up the operation. If not defined, a 2122 default value of 5 is used. 2123 2124 CONFIG_ARP_TIMEOUT 2125 2126 Timeout waiting for an ARP reply in milliseconds. 2127 2128 CONFIG_NFS_TIMEOUT 2129 2130 Timeout in milliseconds used in NFS protocol. 2131 If you encounter "ERROR: Cannot umount" in nfs command, 2132 try longer timeout such as 2133 #define CONFIG_NFS_TIMEOUT 10000UL 2134 2135- Command Interpreter: 2136 CONFIG_SYS_PROMPT_HUSH_PS2 2137 2138 This defines the secondary prompt string, which is 2139 printed when the command interpreter needs more input 2140 to complete a command. Usually "> ". 2141 2142 Note: 2143 2144 In the current implementation, the local variables 2145 space and global environment variables space are 2146 separated. Local variables are those you define by 2147 simply typing `name=value'. To access a local 2148 variable later on, you have write `$name' or 2149 `${name}'; to execute the contents of a variable 2150 directly type `$name' at the command prompt. 2151 2152 Global environment variables are those you use 2153 setenv/printenv to work with. To run a command stored 2154 in such a variable, you need to use the run command, 2155 and you must not use the '$' sign to access them. 2156 2157 To store commands and special characters in a 2158 variable, please use double quotation marks 2159 surrounding the whole text of the variable, instead 2160 of the backslashes before semicolons and special 2161 symbols. 2162 2163- Command Line Editing and History: 2164 CONFIG_CMDLINE_PS_SUPPORT 2165 2166 Enable support for changing the command prompt string 2167 at run-time. Only static string is supported so far. 2168 The string is obtained from environment variables PS1 2169 and PS2. 2170 2171- Default Environment: 2172 CONFIG_EXTRA_ENV_SETTINGS 2173 2174 Define this to contain any number of null terminated 2175 strings (variable = value pairs) that will be part of 2176 the default environment compiled into the boot image. 2177 2178 For example, place something like this in your 2179 board's config file: 2180 2181 #define CONFIG_EXTRA_ENV_SETTINGS \ 2182 "myvar1=value1\0" \ 2183 "myvar2=value2\0" 2184 2185 Warning: This method is based on knowledge about the 2186 internal format how the environment is stored by the 2187 U-Boot code. This is NOT an official, exported 2188 interface! Although it is unlikely that this format 2189 will change soon, there is no guarantee either. 2190 You better know what you are doing here. 2191 2192 Note: overly (ab)use of the default environment is 2193 discouraged. Make sure to check other ways to preset 2194 the environment like the "source" command or the 2195 boot command first. 2196 2197 CONFIG_DELAY_ENVIRONMENT 2198 2199 Normally the environment is loaded when the board is 2200 initialised so that it is available to U-Boot. This inhibits 2201 that so that the environment is not available until 2202 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2203 this is instead controlled by the value of 2204 /config/load-environment. 2205 2206- Serial Flash support 2207 Usage requires an initial 'sf probe' to define the serial 2208 flash parameters, followed by read/write/erase/update 2209 commands. 2210 2211 The following defaults may be provided by the platform 2212 to handle the common case when only a single serial 2213 flash is present on the system. 2214 2215 CONFIG_SF_DEFAULT_BUS Bus identifier 2216 CONFIG_SF_DEFAULT_CS Chip-select 2217 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2218 CONFIG_SF_DEFAULT_SPEED in Hz 2219 2220 2221- TFTP Fixed UDP Port: 2222 CONFIG_TFTP_PORT 2223 2224 If this is defined, the environment variable tftpsrcp 2225 is used to supply the TFTP UDP source port value. 2226 If tftpsrcp isn't defined, the normal pseudo-random port 2227 number generator is used. 2228 2229 Also, the environment variable tftpdstp is used to supply 2230 the TFTP UDP destination port value. If tftpdstp isn't 2231 defined, the normal port 69 is used. 2232 2233 The purpose for tftpsrcp is to allow a TFTP server to 2234 blindly start the TFTP transfer using the pre-configured 2235 target IP address and UDP port. This has the effect of 2236 "punching through" the (Windows XP) firewall, allowing 2237 the remainder of the TFTP transfer to proceed normally. 2238 A better solution is to properly configure the firewall, 2239 but sometimes that is not allowed. 2240 2241- Show boot progress: 2242 CONFIG_SHOW_BOOT_PROGRESS 2243 2244 Defining this option allows to add some board- 2245 specific code (calling a user-provided function 2246 "show_boot_progress(int)") that enables you to show 2247 the system's boot progress on some display (for 2248 example, some LED's) on your board. At the moment, 2249 the following checkpoints are implemented: 2250 2251 2252Legacy uImage format: 2253 2254 Arg Where When 2255 1 common/cmd_bootm.c before attempting to boot an image 2256 -1 common/cmd_bootm.c Image header has bad magic number 2257 2 common/cmd_bootm.c Image header has correct magic number 2258 -2 common/cmd_bootm.c Image header has bad checksum 2259 3 common/cmd_bootm.c Image header has correct checksum 2260 -3 common/cmd_bootm.c Image data has bad checksum 2261 4 common/cmd_bootm.c Image data has correct checksum 2262 -4 common/cmd_bootm.c Image is for unsupported architecture 2263 5 common/cmd_bootm.c Architecture check OK 2264 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2265 6 common/cmd_bootm.c Image Type check OK 2266 -6 common/cmd_bootm.c gunzip uncompression error 2267 -7 common/cmd_bootm.c Unimplemented compression type 2268 7 common/cmd_bootm.c Uncompression OK 2269 8 common/cmd_bootm.c No uncompress/copy overwrite error 2270 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2271 2272 9 common/image.c Start initial ramdisk verification 2273 -10 common/image.c Ramdisk header has bad magic number 2274 -11 common/image.c Ramdisk header has bad checksum 2275 10 common/image.c Ramdisk header is OK 2276 -12 common/image.c Ramdisk data has bad checksum 2277 11 common/image.c Ramdisk data has correct checksum 2278 12 common/image.c Ramdisk verification complete, start loading 2279 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2280 13 common/image.c Start multifile image verification 2281 14 common/image.c No initial ramdisk, no multifile, continue. 2282 2283 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2284 2285 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2286 -31 post/post.c POST test failed, detected by post_output_backlog() 2287 -32 post/post.c POST test failed, detected by post_run_single() 2288 2289 34 common/cmd_doc.c before loading a Image from a DOC device 2290 -35 common/cmd_doc.c Bad usage of "doc" command 2291 35 common/cmd_doc.c correct usage of "doc" command 2292 -36 common/cmd_doc.c No boot device 2293 36 common/cmd_doc.c correct boot device 2294 -37 common/cmd_doc.c Unknown Chip ID on boot device 2295 37 common/cmd_doc.c correct chip ID found, device available 2296 -38 common/cmd_doc.c Read Error on boot device 2297 38 common/cmd_doc.c reading Image header from DOC device OK 2298 -39 common/cmd_doc.c Image header has bad magic number 2299 39 common/cmd_doc.c Image header has correct magic number 2300 -40 common/cmd_doc.c Error reading Image from DOC device 2301 40 common/cmd_doc.c Image header has correct magic number 2302 41 common/cmd_ide.c before loading a Image from a IDE device 2303 -42 common/cmd_ide.c Bad usage of "ide" command 2304 42 common/cmd_ide.c correct usage of "ide" command 2305 -43 common/cmd_ide.c No boot device 2306 43 common/cmd_ide.c boot device found 2307 -44 common/cmd_ide.c Device not available 2308 44 common/cmd_ide.c Device available 2309 -45 common/cmd_ide.c wrong partition selected 2310 45 common/cmd_ide.c partition selected 2311 -46 common/cmd_ide.c Unknown partition table 2312 46 common/cmd_ide.c valid partition table found 2313 -47 common/cmd_ide.c Invalid partition type 2314 47 common/cmd_ide.c correct partition type 2315 -48 common/cmd_ide.c Error reading Image Header on boot device 2316 48 common/cmd_ide.c reading Image Header from IDE device OK 2317 -49 common/cmd_ide.c Image header has bad magic number 2318 49 common/cmd_ide.c Image header has correct magic number 2319 -50 common/cmd_ide.c Image header has bad checksum 2320 50 common/cmd_ide.c Image header has correct checksum 2321 -51 common/cmd_ide.c Error reading Image from IDE device 2322 51 common/cmd_ide.c reading Image from IDE device OK 2323 52 common/cmd_nand.c before loading a Image from a NAND device 2324 -53 common/cmd_nand.c Bad usage of "nand" command 2325 53 common/cmd_nand.c correct usage of "nand" command 2326 -54 common/cmd_nand.c No boot device 2327 54 common/cmd_nand.c boot device found 2328 -55 common/cmd_nand.c Unknown Chip ID on boot device 2329 55 common/cmd_nand.c correct chip ID found, device available 2330 -56 common/cmd_nand.c Error reading Image Header on boot device 2331 56 common/cmd_nand.c reading Image Header from NAND device OK 2332 -57 common/cmd_nand.c Image header has bad magic number 2333 57 common/cmd_nand.c Image header has correct magic number 2334 -58 common/cmd_nand.c Error reading Image from NAND device 2335 58 common/cmd_nand.c reading Image from NAND device OK 2336 2337 -60 common/env_common.c Environment has a bad CRC, using default 2338 2339 64 net/eth.c starting with Ethernet configuration. 2340 -64 net/eth.c no Ethernet found. 2341 65 net/eth.c Ethernet found. 2342 2343 -80 common/cmd_net.c usage wrong 2344 80 common/cmd_net.c before calling net_loop() 2345 -81 common/cmd_net.c some error in net_loop() occurred 2346 81 common/cmd_net.c net_loop() back without error 2347 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2348 82 common/cmd_net.c trying automatic boot 2349 83 common/cmd_net.c running "source" command 2350 -83 common/cmd_net.c some error in automatic boot or "source" command 2351 84 common/cmd_net.c end without errors 2352 2353FIT uImage format: 2354 2355 Arg Where When 2356 100 common/cmd_bootm.c Kernel FIT Image has correct format 2357 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2358 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2359 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2360 102 common/cmd_bootm.c Kernel unit name specified 2361 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2362 103 common/cmd_bootm.c Found configuration node 2363 104 common/cmd_bootm.c Got kernel subimage node offset 2364 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2365 105 common/cmd_bootm.c Kernel subimage hash verification OK 2366 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2367 106 common/cmd_bootm.c Architecture check OK 2368 -106 common/cmd_bootm.c Kernel subimage has wrong type 2369 107 common/cmd_bootm.c Kernel subimage type OK 2370 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2371 108 common/cmd_bootm.c Got kernel subimage data/size 2372 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2373 -109 common/cmd_bootm.c Can't get kernel subimage type 2374 -110 common/cmd_bootm.c Can't get kernel subimage comp 2375 -111 common/cmd_bootm.c Can't get kernel subimage os 2376 -112 common/cmd_bootm.c Can't get kernel subimage load address 2377 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2378 2379 120 common/image.c Start initial ramdisk verification 2380 -120 common/image.c Ramdisk FIT image has incorrect format 2381 121 common/image.c Ramdisk FIT image has correct format 2382 122 common/image.c No ramdisk subimage unit name, using configuration 2383 -122 common/image.c Can't get configuration for ramdisk subimage 2384 123 common/image.c Ramdisk unit name specified 2385 -124 common/image.c Can't get ramdisk subimage node offset 2386 125 common/image.c Got ramdisk subimage node offset 2387 -125 common/image.c Ramdisk subimage hash verification failed 2388 126 common/image.c Ramdisk subimage hash verification OK 2389 -126 common/image.c Ramdisk subimage for unsupported architecture 2390 127 common/image.c Architecture check OK 2391 -127 common/image.c Can't get ramdisk subimage data/size 2392 128 common/image.c Got ramdisk subimage data/size 2393 129 common/image.c Can't get ramdisk load address 2394 -129 common/image.c Got ramdisk load address 2395 2396 -130 common/cmd_doc.c Incorrect FIT image format 2397 131 common/cmd_doc.c FIT image format OK 2398 2399 -140 common/cmd_ide.c Incorrect FIT image format 2400 141 common/cmd_ide.c FIT image format OK 2401 2402 -150 common/cmd_nand.c Incorrect FIT image format 2403 151 common/cmd_nand.c FIT image format OK 2404 2405- Standalone program support: 2406 CONFIG_STANDALONE_LOAD_ADDR 2407 2408 This option defines a board specific value for the 2409 address where standalone program gets loaded, thus 2410 overwriting the architecture dependent default 2411 settings. 2412 2413- Frame Buffer Address: 2414 CONFIG_FB_ADDR 2415 2416 Define CONFIG_FB_ADDR if you want to use specific 2417 address for frame buffer. This is typically the case 2418 when using a graphics controller has separate video 2419 memory. U-Boot will then place the frame buffer at 2420 the given address instead of dynamically reserving it 2421 in system RAM by calling lcd_setmem(), which grabs 2422 the memory for the frame buffer depending on the 2423 configured panel size. 2424 2425 Please see board_init_f function. 2426 2427- Automatic software updates via TFTP server 2428 CONFIG_UPDATE_TFTP 2429 CONFIG_UPDATE_TFTP_CNT_MAX 2430 CONFIG_UPDATE_TFTP_MSEC_MAX 2431 2432 These options enable and control the auto-update feature; 2433 for a more detailed description refer to doc/README.update. 2434 2435- MTD Support (mtdparts command, UBI support) 2436 CONFIG_MTD_DEVICE 2437 2438 Adds the MTD device infrastructure from the Linux kernel. 2439 Needed for mtdparts command support. 2440 2441 CONFIG_MTD_PARTITIONS 2442 2443 Adds the MTD partitioning infrastructure from the Linux 2444 kernel. Needed for UBI support. 2445 2446- UBI support 2447 CONFIG_MTD_UBI_WL_THRESHOLD 2448 This parameter defines the maximum difference between the highest 2449 erase counter value and the lowest erase counter value of eraseblocks 2450 of UBI devices. When this threshold is exceeded, UBI starts performing 2451 wear leveling by means of moving data from eraseblock with low erase 2452 counter to eraseblocks with high erase counter. 2453 2454 The default value should be OK for SLC NAND flashes, NOR flashes and 2455 other flashes which have eraseblock life-cycle 100000 or more. 2456 However, in case of MLC NAND flashes which typically have eraseblock 2457 life-cycle less than 10000, the threshold should be lessened (e.g., 2458 to 128 or 256, although it does not have to be power of 2). 2459 2460 default: 4096 2461 2462 CONFIG_MTD_UBI_BEB_LIMIT 2463 This option specifies the maximum bad physical eraseblocks UBI 2464 expects on the MTD device (per 1024 eraseblocks). If the 2465 underlying flash does not admit of bad eraseblocks (e.g. NOR 2466 flash), this value is ignored. 2467 2468 NAND datasheets often specify the minimum and maximum NVM 2469 (Number of Valid Blocks) for the flashes' endurance lifetime. 2470 The maximum expected bad eraseblocks per 1024 eraseblocks 2471 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2472 which gives 20 for most NANDs (MaxNVB is basically the total 2473 count of eraseblocks on the chip). 2474 2475 To put it differently, if this value is 20, UBI will try to 2476 reserve about 1.9% of physical eraseblocks for bad blocks 2477 handling. And that will be 1.9% of eraseblocks on the entire 2478 NAND chip, not just the MTD partition UBI attaches. This means 2479 that if you have, say, a NAND flash chip admits maximum 40 bad 2480 eraseblocks, and it is split on two MTD partitions of the same 2481 size, UBI will reserve 40 eraseblocks when attaching a 2482 partition. 2483 2484 default: 20 2485 2486 CONFIG_MTD_UBI_FASTMAP 2487 Fastmap is a mechanism which allows attaching an UBI device 2488 in nearly constant time. Instead of scanning the whole MTD device it 2489 only has to locate a checkpoint (called fastmap) on the device. 2490 The on-flash fastmap contains all information needed to attach 2491 the device. Using fastmap makes only sense on large devices where 2492 attaching by scanning takes long. UBI will not automatically install 2493 a fastmap on old images, but you can set the UBI parameter 2494 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2495 that fastmap-enabled images are still usable with UBI implementations 2496 without fastmap support. On typical flash devices the whole fastmap 2497 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2498 2499 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2500 Set this parameter to enable fastmap automatically on images 2501 without a fastmap. 2502 default: 0 2503 2504 CONFIG_MTD_UBI_FM_DEBUG 2505 Enable UBI fastmap debug 2506 default: 0 2507 2508- SPL framework 2509 CONFIG_SPL 2510 Enable building of SPL globally. 2511 2512 CONFIG_SPL_LDSCRIPT 2513 LDSCRIPT for linking the SPL binary. 2514 2515 CONFIG_SPL_MAX_FOOTPRINT 2516 Maximum size in memory allocated to the SPL, BSS included. 2517 When defined, the linker checks that the actual memory 2518 used by SPL from _start to __bss_end does not exceed it. 2519 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2520 must not be both defined at the same time. 2521 2522 CONFIG_SPL_MAX_SIZE 2523 Maximum size of the SPL image (text, data, rodata, and 2524 linker lists sections), BSS excluded. 2525 When defined, the linker checks that the actual size does 2526 not exceed it. 2527 2528 CONFIG_SPL_TEXT_BASE 2529 TEXT_BASE for linking the SPL binary. 2530 2531 CONFIG_SPL_RELOC_TEXT_BASE 2532 Address to relocate to. If unspecified, this is equal to 2533 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2534 2535 CONFIG_SPL_BSS_START_ADDR 2536 Link address for the BSS within the SPL binary. 2537 2538 CONFIG_SPL_BSS_MAX_SIZE 2539 Maximum size in memory allocated to the SPL BSS. 2540 When defined, the linker checks that the actual memory used 2541 by SPL from __bss_start to __bss_end does not exceed it. 2542 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2543 must not be both defined at the same time. 2544 2545 CONFIG_SPL_STACK 2546 Adress of the start of the stack SPL will use 2547 2548 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2549 When defined, SPL will panic() if the image it has 2550 loaded does not have a signature. 2551 Defining this is useful when code which loads images 2552 in SPL cannot guarantee that absolutely all read errors 2553 will be caught. 2554 An example is the LPC32XX MLC NAND driver, which will 2555 consider that a completely unreadable NAND block is bad, 2556 and thus should be skipped silently. 2557 2558 CONFIG_SPL_RELOC_STACK 2559 Adress of the start of the stack SPL will use after 2560 relocation. If unspecified, this is equal to 2561 CONFIG_SPL_STACK. 2562 2563 CONFIG_SYS_SPL_MALLOC_START 2564 Starting address of the malloc pool used in SPL. 2565 When this option is set the full malloc is used in SPL and 2566 it is set up by spl_init() and before that, the simple malloc() 2567 can be used if CONFIG_SYS_MALLOC_F is defined. 2568 2569 CONFIG_SYS_SPL_MALLOC_SIZE 2570 The size of the malloc pool used in SPL. 2571 2572 CONFIG_SPL_OS_BOOT 2573 Enable booting directly to an OS from SPL. 2574 See also: doc/README.falcon 2575 2576 CONFIG_SPL_DISPLAY_PRINT 2577 For ARM, enable an optional function to print more information 2578 about the running system. 2579 2580 CONFIG_SPL_INIT_MINIMAL 2581 Arch init code should be built for a very small image 2582 2583 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2584 Partition on the MMC to load U-Boot from when the MMC is being 2585 used in raw mode 2586 2587 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2588 Sector to load kernel uImage from when MMC is being 2589 used in raw mode (for Falcon mode) 2590 2591 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2592 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2593 Sector and number of sectors to load kernel argument 2594 parameters from when MMC is being used in raw mode 2595 (for falcon mode) 2596 2597 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2598 Partition on the MMC to load U-Boot from when the MMC is being 2599 used in fs mode 2600 2601 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2602 Filename to read to load U-Boot when reading from filesystem 2603 2604 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2605 Filename to read to load kernel uImage when reading 2606 from filesystem (for Falcon mode) 2607 2608 CONFIG_SPL_FS_LOAD_ARGS_NAME 2609 Filename to read to load kernel argument parameters 2610 when reading from filesystem (for Falcon mode) 2611 2612 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2613 Set this for NAND SPL on PPC mpc83xx targets, so that 2614 start.S waits for the rest of the SPL to load before 2615 continuing (the hardware starts execution after just 2616 loading the first page rather than the full 4K). 2617 2618 CONFIG_SPL_SKIP_RELOCATE 2619 Avoid SPL relocation 2620 2621 CONFIG_SPL_NAND_BASE 2622 Include nand_base.c in the SPL. Requires 2623 CONFIG_SPL_NAND_DRIVERS. 2624 2625 CONFIG_SPL_NAND_DRIVERS 2626 SPL uses normal NAND drivers, not minimal drivers. 2627 2628 CONFIG_SPL_NAND_IDENT 2629 SPL uses the chip ID list to identify the NAND flash. 2630 Requires CONFIG_SPL_NAND_BASE. 2631 2632 CONFIG_SPL_NAND_ECC 2633 Include standard software ECC in the SPL 2634 2635 CONFIG_SPL_NAND_SIMPLE 2636 Support for NAND boot using simple NAND drivers that 2637 expose the cmd_ctrl() interface. 2638 2639 CONFIG_SPL_UBI 2640 Support for a lightweight UBI (fastmap) scanner and 2641 loader 2642 2643 CONFIG_SPL_NAND_RAW_ONLY 2644 Support to boot only raw u-boot.bin images. Use this only 2645 if you need to save space. 2646 2647 CONFIG_SPL_COMMON_INIT_DDR 2648 Set for common ddr init with serial presence detect in 2649 SPL binary. 2650 2651 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2652 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2653 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2654 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2655 CONFIG_SYS_NAND_ECCBYTES 2656 Defines the size and behavior of the NAND that SPL uses 2657 to read U-Boot 2658 2659 CONFIG_SPL_NAND_BOOT 2660 Add support NAND boot 2661 2662 CONFIG_SYS_NAND_U_BOOT_OFFS 2663 Location in NAND to read U-Boot from 2664 2665 CONFIG_SYS_NAND_U_BOOT_DST 2666 Location in memory to load U-Boot to 2667 2668 CONFIG_SYS_NAND_U_BOOT_SIZE 2669 Size of image to load 2670 2671 CONFIG_SYS_NAND_U_BOOT_START 2672 Entry point in loaded image to jump to 2673 2674 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2675 Define this if you need to first read the OOB and then the 2676 data. This is used, for example, on davinci platforms. 2677 2678 CONFIG_SPL_RAM_DEVICE 2679 Support for running image already present in ram, in SPL binary 2680 2681 CONFIG_SPL_PAD_TO 2682 Image offset to which the SPL should be padded before appending 2683 the SPL payload. By default, this is defined as 2684 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2685 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2686 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2687 2688 CONFIG_SPL_TARGET 2689 Final target image containing SPL and payload. Some SPLs 2690 use an arch-specific makefile fragment instead, for 2691 example if more than one image needs to be produced. 2692 2693 CONFIG_SPL_FIT_PRINT 2694 Printing information about a FIT image adds quite a bit of 2695 code to SPL. So this is normally disabled in SPL. Use this 2696 option to re-enable it. This will affect the output of the 2697 bootm command when booting a FIT image. 2698 2699- TPL framework 2700 CONFIG_TPL 2701 Enable building of TPL globally. 2702 2703 CONFIG_TPL_PAD_TO 2704 Image offset to which the TPL should be padded before appending 2705 the TPL payload. By default, this is defined as 2706 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2707 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2708 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2709 2710- Interrupt support (PPC): 2711 2712 There are common interrupt_init() and timer_interrupt() 2713 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2714 for CPU specific initialization. interrupt_init_cpu() 2715 should set decrementer_count to appropriate value. If 2716 CPU resets decrementer automatically after interrupt 2717 (ppc4xx) it should set decrementer_count to zero. 2718 timer_interrupt() calls timer_interrupt_cpu() for CPU 2719 specific handling. If board has watchdog / status_led 2720 / other_activity_monitor it works automatically from 2721 general timer_interrupt(). 2722 2723 2724Board initialization settings: 2725------------------------------ 2726 2727During Initialization u-boot calls a number of board specific functions 2728to allow the preparation of board specific prerequisites, e.g. pin setup 2729before drivers are initialized. To enable these callbacks the 2730following configuration macros have to be defined. Currently this is 2731architecture specific, so please check arch/your_architecture/lib/board.c 2732typically in board_init_f() and board_init_r(). 2733 2734- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2735- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2736- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2737- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2738 2739Configuration Settings: 2740----------------------- 2741 2742- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2743 Optionally it can be defined to support 64-bit memory commands. 2744 2745- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2746 undefine this when you're short of memory. 2747 2748- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2749 width of the commands listed in the 'help' command output. 2750 2751- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2752 prompt for user input. 2753 2754- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2755 2756- CONFIG_SYS_PBSIZE: Buffer size for Console output 2757 2758- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2759 2760- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2761 the application (usually a Linux kernel) when it is 2762 booted 2763 2764- CONFIG_SYS_BAUDRATE_TABLE: 2765 List of legal baudrate settings for this board. 2766 2767- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2768 Begin and End addresses of the area used by the 2769 simple memory test. 2770 2771- CONFIG_SYS_MEMTEST_SCRATCH: 2772 Scratch address used by the alternate memory test 2773 You only need to set this if address zero isn't writeable 2774 2775- CONFIG_SYS_MEM_RESERVE_SECURE 2776 Only implemented for ARMv8 for now. 2777 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2778 is substracted from total RAM and won't be reported to OS. 2779 This memory can be used as secure memory. A variable 2780 gd->arch.secure_ram is used to track the location. In systems 2781 the RAM base is not zero, or RAM is divided into banks, 2782 this variable needs to be recalcuated to get the address. 2783 2784- CONFIG_SYS_MEM_TOP_HIDE: 2785 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2786 this specified memory area will get subtracted from the top 2787 (end) of RAM and won't get "touched" at all by U-Boot. By 2788 fixing up gd->ram_size the Linux kernel should gets passed 2789 the now "corrected" memory size and won't touch it either. 2790 This should work for arch/ppc and arch/powerpc. Only Linux 2791 board ports in arch/powerpc with bootwrapper support that 2792 recalculate the memory size from the SDRAM controller setup 2793 will have to get fixed in Linux additionally. 2794 2795 This option can be used as a workaround for the 440EPx/GRx 2796 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2797 be touched. 2798 2799 WARNING: Please make sure that this value is a multiple of 2800 the Linux page size (normally 4k). If this is not the case, 2801 then the end address of the Linux memory will be located at a 2802 non page size aligned address and this could cause major 2803 problems. 2804 2805- CONFIG_SYS_LOADS_BAUD_CHANGE: 2806 Enable temporary baudrate change while serial download 2807 2808- CONFIG_SYS_SDRAM_BASE: 2809 Physical start address of SDRAM. _Must_ be 0 here. 2810 2811- CONFIG_SYS_FLASH_BASE: 2812 Physical start address of Flash memory. 2813 2814- CONFIG_SYS_MONITOR_BASE: 2815 Physical start address of boot monitor code (set by 2816 make config files to be same as the text base address 2817 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2818 CONFIG_SYS_FLASH_BASE when booting from flash. 2819 2820- CONFIG_SYS_MONITOR_LEN: 2821 Size of memory reserved for monitor code, used to 2822 determine _at_compile_time_ (!) if the environment is 2823 embedded within the U-Boot image, or in a separate 2824 flash sector. 2825 2826- CONFIG_SYS_MALLOC_LEN: 2827 Size of DRAM reserved for malloc() use. 2828 2829- CONFIG_SYS_MALLOC_F_LEN 2830 Size of the malloc() pool for use before relocation. If 2831 this is defined, then a very simple malloc() implementation 2832 will become available before relocation. The address is just 2833 below the global data, and the stack is moved down to make 2834 space. 2835 2836 This feature allocates regions with increasing addresses 2837 within the region. calloc() is supported, but realloc() 2838 is not available. free() is supported but does nothing. 2839 The memory will be freed (or in fact just forgotten) when 2840 U-Boot relocates itself. 2841 2842- CONFIG_SYS_MALLOC_SIMPLE 2843 Provides a simple and small malloc() and calloc() for those 2844 boards which do not use the full malloc in SPL (which is 2845 enabled with CONFIG_SYS_SPL_MALLOC_START). 2846 2847- CONFIG_SYS_NONCACHED_MEMORY: 2848 Size of non-cached memory area. This area of memory will be 2849 typically located right below the malloc() area and mapped 2850 uncached in the MMU. This is useful for drivers that would 2851 otherwise require a lot of explicit cache maintenance. For 2852 some drivers it's also impossible to properly maintain the 2853 cache. For example if the regions that need to be flushed 2854 are not a multiple of the cache-line size, *and* padding 2855 cannot be allocated between the regions to align them (i.e. 2856 if the HW requires a contiguous array of regions, and the 2857 size of each region is not cache-aligned), then a flush of 2858 one region may result in overwriting data that hardware has 2859 written to another region in the same cache-line. This can 2860 happen for example in network drivers where descriptors for 2861 buffers are typically smaller than the CPU cache-line (e.g. 2862 16 bytes vs. 32 or 64 bytes). 2863 2864 Non-cached memory is only supported on 32-bit ARM at present. 2865 2866- CONFIG_SYS_BOOTM_LEN: 2867 Normally compressed uImages are limited to an 2868 uncompressed size of 8 MBytes. If this is not enough, 2869 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2870 to adjust this setting to your needs. 2871 2872- CONFIG_SYS_BOOTMAPSZ: 2873 Maximum size of memory mapped by the startup code of 2874 the Linux kernel; all data that must be processed by 2875 the Linux kernel (bd_info, boot arguments, FDT blob if 2876 used) must be put below this limit, unless "bootm_low" 2877 environment variable is defined and non-zero. In such case 2878 all data for the Linux kernel must be between "bootm_low" 2879 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2880 variable "bootm_mapsize" will override the value of 2881 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2882 then the value in "bootm_size" will be used instead. 2883 2884- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2885 Enable initrd_high functionality. If defined then the 2886 initrd_high feature is enabled and the bootm ramdisk subcommand 2887 is enabled. 2888 2889- CONFIG_SYS_BOOT_GET_CMDLINE: 2890 Enables allocating and saving kernel cmdline in space between 2891 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2892 2893- CONFIG_SYS_BOOT_GET_KBD: 2894 Enables allocating and saving a kernel copy of the bd_info in 2895 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2896 2897- CONFIG_SYS_MAX_FLASH_BANKS: 2898 Max number of Flash memory banks 2899 2900- CONFIG_SYS_MAX_FLASH_SECT: 2901 Max number of sectors on a Flash chip 2902 2903- CONFIG_SYS_FLASH_ERASE_TOUT: 2904 Timeout for Flash erase operations (in ms) 2905 2906- CONFIG_SYS_FLASH_WRITE_TOUT: 2907 Timeout for Flash write operations (in ms) 2908 2909- CONFIG_SYS_FLASH_LOCK_TOUT 2910 Timeout for Flash set sector lock bit operation (in ms) 2911 2912- CONFIG_SYS_FLASH_UNLOCK_TOUT 2913 Timeout for Flash clear lock bits operation (in ms) 2914 2915- CONFIG_SYS_FLASH_PROTECTION 2916 If defined, hardware flash sectors protection is used 2917 instead of U-Boot software protection. 2918 2919- CONFIG_SYS_DIRECT_FLASH_TFTP: 2920 2921 Enable TFTP transfers directly to flash memory; 2922 without this option such a download has to be 2923 performed in two steps: (1) download to RAM, and (2) 2924 copy from RAM to flash. 2925 2926 The two-step approach is usually more reliable, since 2927 you can check if the download worked before you erase 2928 the flash, but in some situations (when system RAM is 2929 too limited to allow for a temporary copy of the 2930 downloaded image) this option may be very useful. 2931 2932- CONFIG_SYS_FLASH_CFI: 2933 Define if the flash driver uses extra elements in the 2934 common flash structure for storing flash geometry. 2935 2936- CONFIG_FLASH_CFI_DRIVER 2937 This option also enables the building of the cfi_flash driver 2938 in the drivers directory 2939 2940- CONFIG_FLASH_CFI_MTD 2941 This option enables the building of the cfi_mtd driver 2942 in the drivers directory. The driver exports CFI flash 2943 to the MTD layer. 2944 2945- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2946 Use buffered writes to flash. 2947 2948- CONFIG_FLASH_SPANSION_S29WS_N 2949 s29ws-n MirrorBit flash has non-standard addresses for buffered 2950 write commands. 2951 2952- CONFIG_SYS_FLASH_QUIET_TEST 2953 If this option is defined, the common CFI flash doesn't 2954 print it's warning upon not recognized FLASH banks. This 2955 is useful, if some of the configured banks are only 2956 optionally available. 2957 2958- CONFIG_FLASH_SHOW_PROGRESS 2959 If defined (must be an integer), print out countdown 2960 digits and dots. Recommended value: 45 (9..1) for 80 2961 column displays, 15 (3..1) for 40 column displays. 2962 2963- CONFIG_FLASH_VERIFY 2964 If defined, the content of the flash (destination) is compared 2965 against the source after the write operation. An error message 2966 will be printed when the contents are not identical. 2967 Please note that this option is useless in nearly all cases, 2968 since such flash programming errors usually are detected earlier 2969 while unprotecting/erasing/programming. Please only enable 2970 this option if you really know what you are doing. 2971 2972- CONFIG_SYS_RX_ETH_BUFFER: 2973 Defines the number of Ethernet receive buffers. On some 2974 Ethernet controllers it is recommended to set this value 2975 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2976 buffers can be full shortly after enabling the interface 2977 on high Ethernet traffic. 2978 Defaults to 4 if not defined. 2979 2980- CONFIG_ENV_MAX_ENTRIES 2981 2982 Maximum number of entries in the hash table that is used 2983 internally to store the environment settings. The default 2984 setting is supposed to be generous and should work in most 2985 cases. This setting can be used to tune behaviour; see 2986 lib/hashtable.c for details. 2987 2988- CONFIG_ENV_FLAGS_LIST_DEFAULT 2989- CONFIG_ENV_FLAGS_LIST_STATIC 2990 Enable validation of the values given to environment variables when 2991 calling env set. Variables can be restricted to only decimal, 2992 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 2993 the variables can also be restricted to IP address or MAC address. 2994 2995 The format of the list is: 2996 type_attribute = [s|d|x|b|i|m] 2997 access_attribute = [a|r|o|c] 2998 attributes = type_attribute[access_attribute] 2999 entry = variable_name[:attributes] 3000 list = entry[,list] 3001 3002 The type attributes are: 3003 s - String (default) 3004 d - Decimal 3005 x - Hexadecimal 3006 b - Boolean ([1yYtT|0nNfF]) 3007 i - IP address 3008 m - MAC address 3009 3010 The access attributes are: 3011 a - Any (default) 3012 r - Read-only 3013 o - Write-once 3014 c - Change-default 3015 3016 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3017 Define this to a list (string) to define the ".flags" 3018 environment variable in the default or embedded environment. 3019 3020 - CONFIG_ENV_FLAGS_LIST_STATIC 3021 Define this to a list (string) to define validation that 3022 should be done if an entry is not found in the ".flags" 3023 environment variable. To override a setting in the static 3024 list, simply add an entry for the same variable name to the 3025 ".flags" variable. 3026 3027 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3028 regular expression. This allows multiple variables to define the same 3029 flags without explicitly listing them for each variable. 3030 3031- CONFIG_ENV_ACCESS_IGNORE_FORCE 3032 If defined, don't allow the -f switch to env set override variable 3033 access flags. 3034 3035- CONFIG_USE_STDINT 3036 If stdint.h is available with your toolchain you can define this 3037 option to enable it. You can provide option 'USE_STDINT=1' when 3038 building U-Boot to enable this. 3039 3040The following definitions that deal with the placement and management 3041of environment data (variable area); in general, we support the 3042following configurations: 3043 3044- CONFIG_BUILD_ENVCRC: 3045 3046 Builds up envcrc with the target environment so that external utils 3047 may easily extract it and embed it in final U-Boot images. 3048 3049BE CAREFUL! The first access to the environment happens quite early 3050in U-Boot initialization (when we try to get the setting of for the 3051console baudrate). You *MUST* have mapped your NVRAM area then, or 3052U-Boot will hang. 3053 3054Please note that even with NVRAM we still use a copy of the 3055environment in RAM: we could work on NVRAM directly, but we want to 3056keep settings there always unmodified except somebody uses "saveenv" 3057to save the current settings. 3058 3059BE CAREFUL! For some special cases, the local device can not use 3060"saveenv" command. For example, the local device will get the 3061environment stored in a remote NOR flash by SRIO or PCIE link, 3062but it can not erase, write this NOR flash by SRIO or PCIE interface. 3063 3064- CONFIG_NAND_ENV_DST 3065 3066 Defines address in RAM to which the nand_spl code should copy the 3067 environment. If redundant environment is used, it will be copied to 3068 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3069 3070Please note that the environment is read-only until the monitor 3071has been relocated to RAM and a RAM copy of the environment has been 3072created; also, when using EEPROM you will have to use env_get_f() 3073until then to read environment variables. 3074 3075The environment is protected by a CRC32 checksum. Before the monitor 3076is relocated into RAM, as a result of a bad CRC you will be working 3077with the compiled-in default environment - *silently*!!! [This is 3078necessary, because the first environment variable we need is the 3079"baudrate" setting for the console - if we have a bad CRC, we don't 3080have any device yet where we could complain.] 3081 3082Note: once the monitor has been relocated, then it will complain if 3083the default environment is used; a new CRC is computed as soon as you 3084use the "saveenv" command to store a valid environment. 3085 3086- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3087 Echo the inverted Ethernet link state to the fault LED. 3088 3089 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3090 also needs to be defined. 3091 3092- CONFIG_SYS_FAULT_MII_ADDR: 3093 MII address of the PHY to check for the Ethernet link state. 3094 3095- CONFIG_NS16550_MIN_FUNCTIONS: 3096 Define this if you desire to only have use of the NS16550_init 3097 and NS16550_putc functions for the serial driver located at 3098 drivers/serial/ns16550.c. This option is useful for saving 3099 space for already greatly restricted images, including but not 3100 limited to NAND_SPL configurations. 3101 3102- CONFIG_DISPLAY_BOARDINFO 3103 Display information about the board that U-Boot is running on 3104 when U-Boot starts up. The board function checkboard() is called 3105 to do this. 3106 3107- CONFIG_DISPLAY_BOARDINFO_LATE 3108 Similar to the previous option, but display this information 3109 later, once stdio is running and output goes to the LCD, if 3110 present. 3111 3112- CONFIG_BOARD_SIZE_LIMIT: 3113 Maximum size of the U-Boot image. When defined, the 3114 build system checks that the actual size does not 3115 exceed it. 3116 3117Low Level (hardware related) configuration options: 3118--------------------------------------------------- 3119 3120- CONFIG_SYS_CACHELINE_SIZE: 3121 Cache Line Size of the CPU. 3122 3123- CONFIG_SYS_CCSRBAR_DEFAULT: 3124 Default (power-on reset) physical address of CCSR on Freescale 3125 PowerPC SOCs. 3126 3127- CONFIG_SYS_CCSRBAR: 3128 Virtual address of CCSR. On a 32-bit build, this is typically 3129 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3130 3131- CONFIG_SYS_CCSRBAR_PHYS: 3132 Physical address of CCSR. CCSR can be relocated to a new 3133 physical address, if desired. In this case, this macro should 3134 be set to that address. Otherwise, it should be set to the 3135 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3136 is typically relocated on 36-bit builds. It is recommended 3137 that this macro be defined via the _HIGH and _LOW macros: 3138 3139 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3140 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3141 3142- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3143 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3144 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3145 used in assembly code, so it must not contain typecasts or 3146 integer size suffixes (e.g. "ULL"). 3147 3148- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3149 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3150 used in assembly code, so it must not contain typecasts or 3151 integer size suffixes (e.g. "ULL"). 3152 3153- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3154 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3155 forced to a value that ensures that CCSR is not relocated. 3156 3157- Floppy Disk Support: 3158 CONFIG_SYS_FDC_DRIVE_NUMBER 3159 3160 the default drive number (default value 0) 3161 3162 CONFIG_SYS_ISA_IO_STRIDE 3163 3164 defines the spacing between FDC chipset registers 3165 (default value 1) 3166 3167 CONFIG_SYS_ISA_IO_OFFSET 3168 3169 defines the offset of register from address. It 3170 depends on which part of the data bus is connected to 3171 the FDC chipset. (default value 0) 3172 3173 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3174 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3175 default value. 3176 3177 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3178 fdc_hw_init() is called at the beginning of the FDC 3179 setup. fdc_hw_init() must be provided by the board 3180 source code. It is used to make hardware-dependent 3181 initializations. 3182 3183- CONFIG_IDE_AHB: 3184 Most IDE controllers were designed to be connected with PCI 3185 interface. Only few of them were designed for AHB interface. 3186 When software is doing ATA command and data transfer to 3187 IDE devices through IDE-AHB controller, some additional 3188 registers accessing to these kind of IDE-AHB controller 3189 is required. 3190 3191- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3192 DO NOT CHANGE unless you know exactly what you're 3193 doing! (11-4) [MPC8xx systems only] 3194 3195- CONFIG_SYS_INIT_RAM_ADDR: 3196 3197 Start address of memory area that can be used for 3198 initial data and stack; please note that this must be 3199 writable memory that is working WITHOUT special 3200 initialization, i. e. you CANNOT use normal RAM which 3201 will become available only after programming the 3202 memory controller and running certain initialization 3203 sequences. 3204 3205 U-Boot uses the following memory types: 3206 - MPC8xx: IMMR (internal memory of the CPU) 3207 3208- CONFIG_SYS_GBL_DATA_OFFSET: 3209 3210 Offset of the initial data structure in the memory 3211 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3212 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3213 data is located at the end of the available space 3214 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3215 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3216 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3217 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3218 3219 Note: 3220 On the MPC824X (or other systems that use the data 3221 cache for initial memory) the address chosen for 3222 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3223 point to an otherwise UNUSED address space between 3224 the top of RAM and the start of the PCI space. 3225 3226- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3227 3228- CONFIG_SYS_OR_TIMING_SDRAM: 3229 SDRAM timing 3230 3231- CONFIG_SYS_MAMR_PTA: 3232 periodic timer for refresh 3233 3234- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3235 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3236 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3237 CONFIG_SYS_BR1_PRELIM: 3238 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3239 3240- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3241 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3242 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3243 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3244 3245- CONFIG_PCI_ENUM_ONLY 3246 Only scan through and get the devices on the buses. 3247 Don't do any setup work, presumably because someone or 3248 something has already done it, and we don't need to do it 3249 a second time. Useful for platforms that are pre-booted 3250 by coreboot or similar. 3251 3252- CONFIG_PCI_INDIRECT_BRIDGE: 3253 Enable support for indirect PCI bridges. 3254 3255- CONFIG_SYS_SRIO: 3256 Chip has SRIO or not 3257 3258- CONFIG_SRIO1: 3259 Board has SRIO 1 port available 3260 3261- CONFIG_SRIO2: 3262 Board has SRIO 2 port available 3263 3264- CONFIG_SRIO_PCIE_BOOT_MASTER 3265 Board can support master function for Boot from SRIO and PCIE 3266 3267- CONFIG_SYS_SRIOn_MEM_VIRT: 3268 Virtual Address of SRIO port 'n' memory region 3269 3270- CONFIG_SYS_SRIOn_MEM_PHYS: 3271 Physical Address of SRIO port 'n' memory region 3272 3273- CONFIG_SYS_SRIOn_MEM_SIZE: 3274 Size of SRIO port 'n' memory region 3275 3276- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3277 Defined to tell the NAND controller that the NAND chip is using 3278 a 16 bit bus. 3279 Not all NAND drivers use this symbol. 3280 Example of drivers that use it: 3281 - drivers/mtd/nand/ndfc.c 3282 - drivers/mtd/nand/mxc_nand.c 3283 3284- CONFIG_SYS_NDFC_EBC0_CFG 3285 Sets the EBC0_CFG register for the NDFC. If not defined 3286 a default value will be used. 3287 3288- CONFIG_SPD_EEPROM 3289 Get DDR timing information from an I2C EEPROM. Common 3290 with pluggable memory modules such as SODIMMs 3291 3292 SPD_EEPROM_ADDRESS 3293 I2C address of the SPD EEPROM 3294 3295- CONFIG_SYS_SPD_BUS_NUM 3296 If SPD EEPROM is on an I2C bus other than the first 3297 one, specify here. Note that the value must resolve 3298 to something your driver can deal with. 3299 3300- CONFIG_SYS_DDR_RAW_TIMING 3301 Get DDR timing information from other than SPD. Common with 3302 soldered DDR chips onboard without SPD. DDR raw timing 3303 parameters are extracted from datasheet and hard-coded into 3304 header files or board specific files. 3305 3306- CONFIG_FSL_DDR_INTERACTIVE 3307 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3308 3309- CONFIG_FSL_DDR_SYNC_REFRESH 3310 Enable sync of refresh for multiple controllers. 3311 3312- CONFIG_FSL_DDR_BIST 3313 Enable built-in memory test for Freescale DDR controllers. 3314 3315- CONFIG_SYS_83XX_DDR_USES_CS0 3316 Only for 83xx systems. If specified, then DDR should 3317 be configured using CS0 and CS1 instead of CS2 and CS3. 3318 3319- CONFIG_RMII 3320 Enable RMII mode for all FECs. 3321 Note that this is a global option, we can't 3322 have one FEC in standard MII mode and another in RMII mode. 3323 3324- CONFIG_CRC32_VERIFY 3325 Add a verify option to the crc32 command. 3326 The syntax is: 3327 3328 => crc32 -v <address> <count> <crc32> 3329 3330 Where address/count indicate a memory area 3331 and crc32 is the correct crc32 which the 3332 area should have. 3333 3334- CONFIG_LOOPW 3335 Add the "loopw" memory command. This only takes effect if 3336 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3337 3338- CONFIG_MX_CYCLIC 3339 Add the "mdc" and "mwc" memory commands. These are cyclic 3340 "md/mw" commands. 3341 Examples: 3342 3343 => mdc.b 10 4 500 3344 This command will print 4 bytes (10,11,12,13) each 500 ms. 3345 3346 => mwc.l 100 12345678 10 3347 This command will write 12345678 to address 100 all 10 ms. 3348 3349 This only takes effect if the memory commands are activated 3350 globally (CONFIG_CMD_MEMORY). 3351 3352- CONFIG_SKIP_LOWLEVEL_INIT 3353 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3354 low level initializations (like setting up the memory 3355 controller) are omitted and/or U-Boot does not 3356 relocate itself into RAM. 3357 3358 Normally this variable MUST NOT be defined. The only 3359 exception is when U-Boot is loaded (to RAM) by some 3360 other boot loader or by a debugger which performs 3361 these initializations itself. 3362 3363- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3364 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3365 to be skipped. The normal CP15 init (such as enabling the 3366 instruction cache) is still performed. 3367 3368- CONFIG_SPL_BUILD 3369 Modifies the behaviour of start.S when compiling a loader 3370 that is executed before the actual U-Boot. E.g. when 3371 compiling a NAND SPL. 3372 3373- CONFIG_TPL_BUILD 3374 Modifies the behaviour of start.S when compiling a loader 3375 that is executed after the SPL and before the actual U-Boot. 3376 It is loaded by the SPL. 3377 3378- CONFIG_SYS_MPC85XX_NO_RESETVEC 3379 Only for 85xx systems. If this variable is specified, the section 3380 .resetvec is not kept and the section .bootpg is placed in the 3381 previous 4k of the .text section. 3382 3383- CONFIG_ARCH_MAP_SYSMEM 3384 Generally U-Boot (and in particular the md command) uses 3385 effective address. It is therefore not necessary to regard 3386 U-Boot address as virtual addresses that need to be translated 3387 to physical addresses. However, sandbox requires this, since 3388 it maintains its own little RAM buffer which contains all 3389 addressable memory. This option causes some memory accesses 3390 to be mapped through map_sysmem() / unmap_sysmem(). 3391 3392- CONFIG_X86_RESET_VECTOR 3393 If defined, the x86 reset vector code is included. This is not 3394 needed when U-Boot is running from Coreboot. 3395 3396- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3397 Option to disable subpage write in NAND driver 3398 driver that uses this: 3399 drivers/mtd/nand/davinci_nand.c 3400 3401Freescale QE/FMAN Firmware Support: 3402----------------------------------- 3403 3404The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3405loading of "firmware", which is encoded in the QE firmware binary format. 3406This firmware often needs to be loaded during U-Boot booting, so macros 3407are used to identify the storage device (NOR flash, SPI, etc) and the address 3408within that device. 3409 3410- CONFIG_SYS_FMAN_FW_ADDR 3411 The address in the storage device where the FMAN microcode is located. The 3412 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3413 is also specified. 3414 3415- CONFIG_SYS_QE_FW_ADDR 3416 The address in the storage device where the QE microcode is located. The 3417 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3418 is also specified. 3419 3420- CONFIG_SYS_QE_FMAN_FW_LENGTH 3421 The maximum possible size of the firmware. The firmware binary format 3422 has a field that specifies the actual size of the firmware, but it 3423 might not be possible to read any part of the firmware unless some 3424 local storage is allocated to hold the entire firmware first. 3425 3426- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3427 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3428 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3429 virtual address in NOR flash. 3430 3431- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3432 Specifies that QE/FMAN firmware is located in NAND flash. 3433 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3434 3435- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3436 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3437 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3438 3439- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3440 Specifies that QE/FMAN firmware is located in the remote (master) 3441 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3442 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3443 window->master inbound window->master LAW->the ucode address in 3444 master's memory space. 3445 3446Freescale Layerscape Management Complex Firmware Support: 3447--------------------------------------------------------- 3448The Freescale Layerscape Management Complex (MC) supports the loading of 3449"firmware". 3450This firmware often needs to be loaded during U-Boot booting, so macros 3451are used to identify the storage device (NOR flash, SPI, etc) and the address 3452within that device. 3453 3454- CONFIG_FSL_MC_ENET 3455 Enable the MC driver for Layerscape SoCs. 3456 3457Freescale Layerscape Debug Server Support: 3458------------------------------------------- 3459The Freescale Layerscape Debug Server Support supports the loading of 3460"Debug Server firmware" and triggering SP boot-rom. 3461This firmware often needs to be loaded during U-Boot booting. 3462 3463- CONFIG_SYS_MC_RSV_MEM_ALIGN 3464 Define alignment of reserved memory MC requires 3465 3466Reproducible builds 3467------------------- 3468 3469In order to achieve reproducible builds, timestamps used in the U-Boot build 3470process have to be set to a fixed value. 3471 3472This is done using the SOURCE_DATE_EPOCH environment variable. 3473SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3474option for U-Boot or an environment variable in U-Boot. 3475 3476SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3477 3478Building the Software: 3479====================== 3480 3481Building U-Boot has been tested in several native build environments 3482and in many different cross environments. Of course we cannot support 3483all possibly existing versions of cross development tools in all 3484(potentially obsolete) versions. In case of tool chain problems we 3485recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3486which is extensively used to build and test U-Boot. 3487 3488If you are not using a native environment, it is assumed that you 3489have GNU cross compiling tools available in your path. In this case, 3490you must set the environment variable CROSS_COMPILE in your shell. 3491Note that no changes to the Makefile or any other source files are 3492necessary. For example using the ELDK on a 4xx CPU, please enter: 3493 3494 $ CROSS_COMPILE=ppc_4xx- 3495 $ export CROSS_COMPILE 3496 3497Note: If you wish to generate Windows versions of the utilities in 3498 the tools directory you can use the MinGW toolchain 3499 (http://www.mingw.org). Set your HOST tools to the MinGW 3500 toolchain and execute 'make tools'. For example: 3501 3502 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3503 3504 Binaries such as tools/mkimage.exe will be created which can 3505 be executed on computers running Windows. 3506 3507U-Boot is intended to be simple to build. After installing the 3508sources you must configure U-Boot for one specific board type. This 3509is done by typing: 3510 3511 make NAME_defconfig 3512 3513where "NAME_defconfig" is the name of one of the existing configu- 3514rations; see boards.cfg for supported names. 3515 3516Note: for some board special configuration names may exist; check if 3517 additional information is available from the board vendor; for 3518 instance, the TQM823L systems are available without (standard) 3519 or with LCD support. You can select such additional "features" 3520 when choosing the configuration, i. e. 3521 3522 make TQM823L_defconfig 3523 - will configure for a plain TQM823L, i. e. no LCD support 3524 3525 make TQM823L_LCD_defconfig 3526 - will configure for a TQM823L with U-Boot console on LCD 3527 3528 etc. 3529 3530 3531Finally, type "make all", and you should get some working U-Boot 3532images ready for download to / installation on your system: 3533 3534- "u-boot.bin" is a raw binary image 3535- "u-boot" is an image in ELF binary format 3536- "u-boot.srec" is in Motorola S-Record format 3537 3538By default the build is performed locally and the objects are saved 3539in the source directory. One of the two methods can be used to change 3540this behavior and build U-Boot to some external directory: 3541 35421. Add O= to the make command line invocations: 3543 3544 make O=/tmp/build distclean 3545 make O=/tmp/build NAME_defconfig 3546 make O=/tmp/build all 3547 35482. Set environment variable KBUILD_OUTPUT to point to the desired location: 3549 3550 export KBUILD_OUTPUT=/tmp/build 3551 make distclean 3552 make NAME_defconfig 3553 make all 3554 3555Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3556variable. 3557 3558User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3559setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3560For example to treat all compiler warnings as errors: 3561 3562 make KCFLAGS=-Werror 3563 3564Please be aware that the Makefiles assume you are using GNU make, so 3565for instance on NetBSD you might need to use "gmake" instead of 3566native "make". 3567 3568 3569If the system board that you have is not listed, then you will need 3570to port U-Boot to your hardware platform. To do this, follow these 3571steps: 3572 35731. Create a new directory to hold your board specific code. Add any 3574 files you need. In your board directory, you will need at least 3575 the "Makefile" and a "<board>.c". 35762. Create a new configuration file "include/configs/<board>.h" for 3577 your board. 35783. If you're porting U-Boot to a new CPU, then also create a new 3579 directory to hold your CPU specific code. Add any files you need. 35804. Run "make <board>_defconfig" with your new name. 35815. Type "make", and you should get a working "u-boot.srec" file 3582 to be installed on your target system. 35836. Debug and solve any problems that might arise. 3584 [Of course, this last step is much harder than it sounds.] 3585 3586 3587Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3588============================================================== 3589 3590If you have modified U-Boot sources (for instance added a new board 3591or support for new devices, a new CPU, etc.) you are expected to 3592provide feedback to the other developers. The feedback normally takes 3593the form of a "patch", i. e. a context diff against a certain (latest 3594official or latest in the git repository) version of U-Boot sources. 3595 3596But before you submit such a patch, please verify that your modifi- 3597cation did not break existing code. At least make sure that *ALL* of 3598the supported boards compile WITHOUT ANY compiler warnings. To do so, 3599just run the buildman script (tools/buildman/buildman), which will 3600configure and build U-Boot for ALL supported system. Be warned, this 3601will take a while. Please see the buildman README, or run 'buildman -H' 3602for documentation. 3603 3604 3605See also "U-Boot Porting Guide" below. 3606 3607 3608Monitor Commands - Overview: 3609============================ 3610 3611go - start application at address 'addr' 3612run - run commands in an environment variable 3613bootm - boot application image from memory 3614bootp - boot image via network using BootP/TFTP protocol 3615bootz - boot zImage from memory 3616tftpboot- boot image via network using TFTP protocol 3617 and env variables "ipaddr" and "serverip" 3618 (and eventually "gatewayip") 3619tftpput - upload a file via network using TFTP protocol 3620rarpboot- boot image via network using RARP/TFTP protocol 3621diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3622loads - load S-Record file over serial line 3623loadb - load binary file over serial line (kermit mode) 3624md - memory display 3625mm - memory modify (auto-incrementing) 3626nm - memory modify (constant address) 3627mw - memory write (fill) 3628cp - memory copy 3629cmp - memory compare 3630crc32 - checksum calculation 3631i2c - I2C sub-system 3632sspi - SPI utility commands 3633base - print or set address offset 3634printenv- print environment variables 3635setenv - set environment variables 3636saveenv - save environment variables to persistent storage 3637protect - enable or disable FLASH write protection 3638erase - erase FLASH memory 3639flinfo - print FLASH memory information 3640nand - NAND memory operations (see doc/README.nand) 3641bdinfo - print Board Info structure 3642iminfo - print header information for application image 3643coninfo - print console devices and informations 3644ide - IDE sub-system 3645loop - infinite loop on address range 3646loopw - infinite write loop on address range 3647mtest - simple RAM test 3648icache - enable or disable instruction cache 3649dcache - enable or disable data cache 3650reset - Perform RESET of the CPU 3651echo - echo args to console 3652version - print monitor version 3653help - print online help 3654? - alias for 'help' 3655 3656 3657Monitor Commands - Detailed Description: 3658======================================== 3659 3660TODO. 3661 3662For now: just type "help <command>". 3663 3664 3665Environment Variables: 3666====================== 3667 3668U-Boot supports user configuration using Environment Variables which 3669can be made persistent by saving to Flash memory. 3670 3671Environment Variables are set using "setenv", printed using 3672"printenv", and saved to Flash using "saveenv". Using "setenv" 3673without a value can be used to delete a variable from the 3674environment. As long as you don't save the environment you are 3675working with an in-memory copy. In case the Flash area containing the 3676environment is erased by accident, a default environment is provided. 3677 3678Some configuration options can be set using Environment Variables. 3679 3680List of environment variables (most likely not complete): 3681 3682 baudrate - see CONFIG_BAUDRATE 3683 3684 bootdelay - see CONFIG_BOOTDELAY 3685 3686 bootcmd - see CONFIG_BOOTCOMMAND 3687 3688 bootargs - Boot arguments when booting an RTOS image 3689 3690 bootfile - Name of the image to load with TFTP 3691 3692 bootm_low - Memory range available for image processing in the bootm 3693 command can be restricted. This variable is given as 3694 a hexadecimal number and defines lowest address allowed 3695 for use by the bootm command. See also "bootm_size" 3696 environment variable. Address defined by "bootm_low" is 3697 also the base of the initial memory mapping for the Linux 3698 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3699 bootm_mapsize. 3700 3701 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3702 This variable is given as a hexadecimal number and it 3703 defines the size of the memory region starting at base 3704 address bootm_low that is accessible by the Linux kernel 3705 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3706 as the default value if it is defined, and bootm_size is 3707 used otherwise. 3708 3709 bootm_size - Memory range available for image processing in the bootm 3710 command can be restricted. This variable is given as 3711 a hexadecimal number and defines the size of the region 3712 allowed for use by the bootm command. See also "bootm_low" 3713 environment variable. 3714 3715 updatefile - Location of the software update file on a TFTP server, used 3716 by the automatic software update feature. Please refer to 3717 documentation in doc/README.update for more details. 3718 3719 autoload - if set to "no" (any string beginning with 'n'), 3720 "bootp" will just load perform a lookup of the 3721 configuration from the BOOTP server, but not try to 3722 load any image using TFTP 3723 3724 autostart - if set to "yes", an image loaded using the "bootp", 3725 "rarpboot", "tftpboot" or "diskboot" commands will 3726 be automatically started (by internally calling 3727 "bootm") 3728 3729 If set to "no", a standalone image passed to the 3730 "bootm" command will be copied to the load address 3731 (and eventually uncompressed), but NOT be started. 3732 This can be used to load and uncompress arbitrary 3733 data. 3734 3735 fdt_high - if set this restricts the maximum address that the 3736 flattened device tree will be copied into upon boot. 3737 For example, if you have a system with 1 GB memory 3738 at physical address 0x10000000, while Linux kernel 3739 only recognizes the first 704 MB as low memory, you 3740 may need to set fdt_high as 0x3C000000 to have the 3741 device tree blob be copied to the maximum address 3742 of the 704 MB low memory, so that Linux kernel can 3743 access it during the boot procedure. 3744 3745 If this is set to the special value 0xFFFFFFFF then 3746 the fdt will not be copied at all on boot. For this 3747 to work it must reside in writable memory, have 3748 sufficient padding on the end of it for u-boot to 3749 add the information it needs into it, and the memory 3750 must be accessible by the kernel. 3751 3752 fdtcontroladdr- if set this is the address of the control flattened 3753 device tree used by U-Boot when CONFIG_OF_CONTROL is 3754 defined. 3755 3756 i2cfast - (PPC405GP|PPC405EP only) 3757 if set to 'y' configures Linux I2C driver for fast 3758 mode (400kHZ). This environment variable is used in 3759 initialization code. So, for changes to be effective 3760 it must be saved and board must be reset. 3761 3762 initrd_high - restrict positioning of initrd images: 3763 If this variable is not set, initrd images will be 3764 copied to the highest possible address in RAM; this 3765 is usually what you want since it allows for 3766 maximum initrd size. If for some reason you want to 3767 make sure that the initrd image is loaded below the 3768 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3769 variable to a value of "no" or "off" or "0". 3770 Alternatively, you can set it to a maximum upper 3771 address to use (U-Boot will still check that it 3772 does not overwrite the U-Boot stack and data). 3773 3774 For instance, when you have a system with 16 MB 3775 RAM, and want to reserve 4 MB from use by Linux, 3776 you can do this by adding "mem=12M" to the value of 3777 the "bootargs" variable. However, now you must make 3778 sure that the initrd image is placed in the first 3779 12 MB as well - this can be done with 3780 3781 setenv initrd_high 00c00000 3782 3783 If you set initrd_high to 0xFFFFFFFF, this is an 3784 indication to U-Boot that all addresses are legal 3785 for the Linux kernel, including addresses in flash 3786 memory. In this case U-Boot will NOT COPY the 3787 ramdisk at all. This may be useful to reduce the 3788 boot time on your system, but requires that this 3789 feature is supported by your Linux kernel. 3790 3791 ipaddr - IP address; needed for tftpboot command 3792 3793 loadaddr - Default load address for commands like "bootp", 3794 "rarpboot", "tftpboot", "loadb" or "diskboot" 3795 3796 loads_echo - see CONFIG_LOADS_ECHO 3797 3798 serverip - TFTP server IP address; needed for tftpboot command 3799 3800 bootretry - see CONFIG_BOOT_RETRY_TIME 3801 3802 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3803 3804 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3805 3806 ethprime - controls which interface is used first. 3807 3808 ethact - controls which interface is currently active. 3809 For example you can do the following 3810 3811 => setenv ethact FEC 3812 => ping 192.168.0.1 # traffic sent on FEC 3813 => setenv ethact SCC 3814 => ping 10.0.0.1 # traffic sent on SCC 3815 3816 ethrotate - When set to "no" U-Boot does not go through all 3817 available network interfaces. 3818 It just stays at the currently selected interface. 3819 3820 netretry - When set to "no" each network operation will 3821 either succeed or fail without retrying. 3822 When set to "once" the network operation will 3823 fail when all the available network interfaces 3824 are tried once without success. 3825 Useful on scripts which control the retry operation 3826 themselves. 3827 3828 npe_ucode - set load address for the NPE microcode 3829 3830 silent_linux - If set then Linux will be told to boot silently, by 3831 changing the console to be empty. If "yes" it will be 3832 made silent. If "no" it will not be made silent. If 3833 unset, then it will be made silent if the U-Boot console 3834 is silent. 3835 3836 tftpsrcp - If this is set, the value is used for TFTP's 3837 UDP source port. 3838 3839 tftpdstp - If this is set, the value is used for TFTP's UDP 3840 destination port instead of the Well Know Port 69. 3841 3842 tftpblocksize - Block size to use for TFTP transfers; if not set, 3843 we use the TFTP server's default block size 3844 3845 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3846 seconds, minimum value is 1000 = 1 second). Defines 3847 when a packet is considered to be lost so it has to 3848 be retransmitted. The default is 5000 = 5 seconds. 3849 Lowering this value may make downloads succeed 3850 faster in networks with high packet loss rates or 3851 with unreliable TFTP servers. 3852 3853 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3854 unit, minimum value = 0). Defines how many timeouts 3855 can happen during a single file transfer before that 3856 transfer is aborted. The default is 10, and 0 means 3857 'no timeouts allowed'. Increasing this value may help 3858 downloads succeed with high packet loss rates, or with 3859 unreliable TFTP servers or client hardware. 3860 3861 vlan - When set to a value < 4095 the traffic over 3862 Ethernet is encapsulated/received over 802.1q 3863 VLAN tagged frames. 3864 3865 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3866 Unsigned value, in milliseconds. If not set, the period will 3867 be either the default (28000), or a value based on 3868 CONFIG_NET_RETRY_COUNT, if defined. This value has 3869 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3870 3871The following image location variables contain the location of images 3872used in booting. The "Image" column gives the role of the image and is 3873not an environment variable name. The other columns are environment 3874variable names. "File Name" gives the name of the file on a TFTP 3875server, "RAM Address" gives the location in RAM the image will be 3876loaded to, and "Flash Location" gives the image's address in NOR 3877flash or offset in NAND flash. 3878 3879*Note* - these variables don't have to be defined for all boards, some 3880boards currently use other variables for these purposes, and some 3881boards use these variables for other purposes. 3882 3883Image File Name RAM Address Flash Location 3884----- --------- ----------- -------------- 3885u-boot u-boot u-boot_addr_r u-boot_addr 3886Linux kernel bootfile kernel_addr_r kernel_addr 3887device tree blob fdtfile fdt_addr_r fdt_addr 3888ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3889 3890The following environment variables may be used and automatically 3891updated by the network boot commands ("bootp" and "rarpboot"), 3892depending the information provided by your boot server: 3893 3894 bootfile - see above 3895 dnsip - IP address of your Domain Name Server 3896 dnsip2 - IP address of your secondary Domain Name Server 3897 gatewayip - IP address of the Gateway (Router) to use 3898 hostname - Target hostname 3899 ipaddr - see above 3900 netmask - Subnet Mask 3901 rootpath - Pathname of the root filesystem on the NFS server 3902 serverip - see above 3903 3904 3905There are two special Environment Variables: 3906 3907 serial# - contains hardware identification information such 3908 as type string and/or serial number 3909 ethaddr - Ethernet address 3910 3911These variables can be set only once (usually during manufacturing of 3912the board). U-Boot refuses to delete or overwrite these variables 3913once they have been set once. 3914 3915 3916Further special Environment Variables: 3917 3918 ver - Contains the U-Boot version string as printed 3919 with the "version" command. This variable is 3920 readonly (see CONFIG_VERSION_VARIABLE). 3921 3922 3923Please note that changes to some configuration parameters may take 3924only effect after the next boot (yes, that's just like Windoze :-). 3925 3926 3927Callback functions for environment variables: 3928--------------------------------------------- 3929 3930For some environment variables, the behavior of u-boot needs to change 3931when their values are changed. This functionality allows functions to 3932be associated with arbitrary variables. On creation, overwrite, or 3933deletion, the callback will provide the opportunity for some side 3934effect to happen or for the change to be rejected. 3935 3936The callbacks are named and associated with a function using the 3937U_BOOT_ENV_CALLBACK macro in your board or driver code. 3938 3939These callbacks are associated with variables in one of two ways. The 3940static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3941in the board configuration to a string that defines a list of 3942associations. The list must be in the following format: 3943 3944 entry = variable_name[:callback_name] 3945 list = entry[,list] 3946 3947If the callback name is not specified, then the callback is deleted. 3948Spaces are also allowed anywhere in the list. 3949 3950Callbacks can also be associated by defining the ".callbacks" variable 3951with the same list format above. Any association in ".callbacks" will 3952override any association in the static list. You can define 3953CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 3954".callbacks" environment variable in the default or embedded environment. 3955 3956If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3957regular expression. This allows multiple variables to be connected to 3958the same callback without explicitly listing them all out. 3959 3960 3961Command Line Parsing: 3962===================== 3963 3964There are two different command line parsers available with U-Boot: 3965the old "simple" one, and the much more powerful "hush" shell: 3966 3967Old, simple command line parser: 3968-------------------------------- 3969 3970- supports environment variables (through setenv / saveenv commands) 3971- several commands on one line, separated by ';' 3972- variable substitution using "... ${name} ..." syntax 3973- special characters ('$', ';') can be escaped by prefixing with '\', 3974 for example: 3975 setenv bootcmd bootm \${address} 3976- You can also escape text by enclosing in single apostrophes, for example: 3977 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 3978 3979Hush shell: 3980----------- 3981 3982- similar to Bourne shell, with control structures like 3983 if...then...else...fi, for...do...done; while...do...done, 3984 until...do...done, ... 3985- supports environment ("global") variables (through setenv / saveenv 3986 commands) and local shell variables (through standard shell syntax 3987 "name=value"); only environment variables can be used with "run" 3988 command 3989 3990General rules: 3991-------------- 3992 3993(1) If a command line (or an environment variable executed by a "run" 3994 command) contains several commands separated by semicolon, and 3995 one of these commands fails, then the remaining commands will be 3996 executed anyway. 3997 3998(2) If you execute several variables with one call to run (i. e. 3999 calling run with a list of variables as arguments), any failing 4000 command will cause "run" to terminate, i. e. the remaining 4001 variables are not executed. 4002 4003Note for Redundant Ethernet Interfaces: 4004======================================= 4005 4006Some boards come with redundant Ethernet interfaces; U-Boot supports 4007such configurations and is capable of automatic selection of a 4008"working" interface when needed. MAC assignment works as follows: 4009 4010Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4011MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4012"eth1addr" (=>eth1), "eth2addr", ... 4013 4014If the network interface stores some valid MAC address (for instance 4015in SROM), this is used as default address if there is NO correspon- 4016ding setting in the environment; if the corresponding environment 4017variable is set, this overrides the settings in the card; that means: 4018 4019o If the SROM has a valid MAC address, and there is no address in the 4020 environment, the SROM's address is used. 4021 4022o If there is no valid address in the SROM, and a definition in the 4023 environment exists, then the value from the environment variable is 4024 used. 4025 4026o If both the SROM and the environment contain a MAC address, and 4027 both addresses are the same, this MAC address is used. 4028 4029o If both the SROM and the environment contain a MAC address, and the 4030 addresses differ, the value from the environment is used and a 4031 warning is printed. 4032 4033o If neither SROM nor the environment contain a MAC address, an error 4034 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4035 a random, locally-assigned MAC is used. 4036 4037If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4038will be programmed into hardware as part of the initialization process. This 4039may be skipped by setting the appropriate 'ethmacskip' environment variable. 4040The naming convention is as follows: 4041"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4042 4043Image Formats: 4044============== 4045 4046U-Boot is capable of booting (and performing other auxiliary operations on) 4047images in two formats: 4048 4049New uImage format (FIT) 4050----------------------- 4051 4052Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4053to Flattened Device Tree). It allows the use of images with multiple 4054components (several kernels, ramdisks, etc.), with contents protected by 4055SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4056 4057 4058Old uImage format 4059----------------- 4060 4061Old image format is based on binary files which can be basically anything, 4062preceded by a special header; see the definitions in include/image.h for 4063details; basically, the header defines the following image properties: 4064 4065* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4066 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4067 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4068 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4069 INTEGRITY). 4070* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4071 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4072 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4073* Compression Type (uncompressed, gzip, bzip2) 4074* Load Address 4075* Entry Point 4076* Image Name 4077* Image Timestamp 4078 4079The header is marked by a special Magic Number, and both the header 4080and the data portions of the image are secured against corruption by 4081CRC32 checksums. 4082 4083 4084Linux Support: 4085============== 4086 4087Although U-Boot should support any OS or standalone application 4088easily, the main focus has always been on Linux during the design of 4089U-Boot. 4090 4091U-Boot includes many features that so far have been part of some 4092special "boot loader" code within the Linux kernel. Also, any 4093"initrd" images to be used are no longer part of one big Linux image; 4094instead, kernel and "initrd" are separate images. This implementation 4095serves several purposes: 4096 4097- the same features can be used for other OS or standalone 4098 applications (for instance: using compressed images to reduce the 4099 Flash memory footprint) 4100 4101- it becomes much easier to port new Linux kernel versions because 4102 lots of low-level, hardware dependent stuff are done by U-Boot 4103 4104- the same Linux kernel image can now be used with different "initrd" 4105 images; of course this also means that different kernel images can 4106 be run with the same "initrd". This makes testing easier (you don't 4107 have to build a new "zImage.initrd" Linux image when you just 4108 change a file in your "initrd"). Also, a field-upgrade of the 4109 software is easier now. 4110 4111 4112Linux HOWTO: 4113============ 4114 4115Porting Linux to U-Boot based systems: 4116--------------------------------------- 4117 4118U-Boot cannot save you from doing all the necessary modifications to 4119configure the Linux device drivers for use with your target hardware 4120(no, we don't intend to provide a full virtual machine interface to 4121Linux :-). 4122 4123But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4124 4125Just make sure your machine specific header file (for instance 4126include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4127Information structure as we define in include/asm-<arch>/u-boot.h, 4128and make sure that your definition of IMAP_ADDR uses the same value 4129as your U-Boot configuration in CONFIG_SYS_IMMR. 4130 4131Note that U-Boot now has a driver model, a unified model for drivers. 4132If you are adding a new driver, plumb it into driver model. If there 4133is no uclass available, you are encouraged to create one. See 4134doc/driver-model. 4135 4136 4137Configuring the Linux kernel: 4138----------------------------- 4139 4140No specific requirements for U-Boot. Make sure you have some root 4141device (initial ramdisk, NFS) for your target system. 4142 4143 4144Building a Linux Image: 4145----------------------- 4146 4147With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4148not used. If you use recent kernel source, a new build target 4149"uImage" will exist which automatically builds an image usable by 4150U-Boot. Most older kernels also have support for a "pImage" target, 4151which was introduced for our predecessor project PPCBoot and uses a 4152100% compatible format. 4153 4154Example: 4155 4156 make TQM850L_defconfig 4157 make oldconfig 4158 make dep 4159 make uImage 4160 4161The "uImage" build target uses a special tool (in 'tools/mkimage') to 4162encapsulate a compressed Linux kernel image with header information, 4163CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4164 4165* build a standard "vmlinux" kernel image (in ELF binary format): 4166 4167* convert the kernel into a raw binary image: 4168 4169 ${CROSS_COMPILE}-objcopy -O binary \ 4170 -R .note -R .comment \ 4171 -S vmlinux linux.bin 4172 4173* compress the binary image: 4174 4175 gzip -9 linux.bin 4176 4177* package compressed binary image for U-Boot: 4178 4179 mkimage -A ppc -O linux -T kernel -C gzip \ 4180 -a 0 -e 0 -n "Linux Kernel Image" \ 4181 -d linux.bin.gz uImage 4182 4183 4184The "mkimage" tool can also be used to create ramdisk images for use 4185with U-Boot, either separated from the Linux kernel image, or 4186combined into one file. "mkimage" encapsulates the images with a 64 4187byte header containing information about target architecture, 4188operating system, image type, compression method, entry points, time 4189stamp, CRC32 checksums, etc. 4190 4191"mkimage" can be called in two ways: to verify existing images and 4192print the header information, or to build new images. 4193 4194In the first form (with "-l" option) mkimage lists the information 4195contained in the header of an existing U-Boot image; this includes 4196checksum verification: 4197 4198 tools/mkimage -l image 4199 -l ==> list image header information 4200 4201The second form (with "-d" option) is used to build a U-Boot image 4202from a "data file" which is used as image payload: 4203 4204 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4205 -n name -d data_file image 4206 -A ==> set architecture to 'arch' 4207 -O ==> set operating system to 'os' 4208 -T ==> set image type to 'type' 4209 -C ==> set compression type 'comp' 4210 -a ==> set load address to 'addr' (hex) 4211 -e ==> set entry point to 'ep' (hex) 4212 -n ==> set image name to 'name' 4213 -d ==> use image data from 'datafile' 4214 4215Right now, all Linux kernels for PowerPC systems use the same load 4216address (0x00000000), but the entry point address depends on the 4217kernel version: 4218 4219- 2.2.x kernels have the entry point at 0x0000000C, 4220- 2.3.x and later kernels have the entry point at 0x00000000. 4221 4222So a typical call to build a U-Boot image would read: 4223 4224 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4225 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4226 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4227 > examples/uImage.TQM850L 4228 Image Name: 2.4.4 kernel for TQM850L 4229 Created: Wed Jul 19 02:34:59 2000 4230 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4231 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4232 Load Address: 0x00000000 4233 Entry Point: 0x00000000 4234 4235To verify the contents of the image (or check for corruption): 4236 4237 -> tools/mkimage -l examples/uImage.TQM850L 4238 Image Name: 2.4.4 kernel for TQM850L 4239 Created: Wed Jul 19 02:34:59 2000 4240 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4241 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4242 Load Address: 0x00000000 4243 Entry Point: 0x00000000 4244 4245NOTE: for embedded systems where boot time is critical you can trade 4246speed for memory and install an UNCOMPRESSED image instead: this 4247needs more space in Flash, but boots much faster since it does not 4248need to be uncompressed: 4249 4250 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4251 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4252 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4253 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4254 > examples/uImage.TQM850L-uncompressed 4255 Image Name: 2.4.4 kernel for TQM850L 4256 Created: Wed Jul 19 02:34:59 2000 4257 Image Type: PowerPC Linux Kernel Image (uncompressed) 4258 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4259 Load Address: 0x00000000 4260 Entry Point: 0x00000000 4261 4262 4263Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4264when your kernel is intended to use an initial ramdisk: 4265 4266 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4267 > -A ppc -O linux -T ramdisk -C gzip \ 4268 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4269 Image Name: Simple Ramdisk Image 4270 Created: Wed Jan 12 14:01:50 2000 4271 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4272 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4273 Load Address: 0x00000000 4274 Entry Point: 0x00000000 4275 4276The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4277option performs the converse operation of the mkimage's second form (the "-d" 4278option). Given an image built by mkimage, the dumpimage extracts a "data file" 4279from the image: 4280 4281 tools/dumpimage -i image -T type -p position data_file 4282 -i ==> extract from the 'image' a specific 'data_file' 4283 -T ==> set image type to 'type' 4284 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4285 4286 4287Installing a Linux Image: 4288------------------------- 4289 4290To downloading a U-Boot image over the serial (console) interface, 4291you must convert the image to S-Record format: 4292 4293 objcopy -I binary -O srec examples/image examples/image.srec 4294 4295The 'objcopy' does not understand the information in the U-Boot 4296image header, so the resulting S-Record file will be relative to 4297address 0x00000000. To load it to a given address, you need to 4298specify the target address as 'offset' parameter with the 'loads' 4299command. 4300 4301Example: install the image to address 0x40100000 (which on the 4302TQM8xxL is in the first Flash bank): 4303 4304 => erase 40100000 401FFFFF 4305 4306 .......... done 4307 Erased 8 sectors 4308 4309 => loads 40100000 4310 ## Ready for S-Record download ... 4311 ~>examples/image.srec 4312 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4313 ... 4314 15989 15990 15991 15992 4315 [file transfer complete] 4316 [connected] 4317 ## Start Addr = 0x00000000 4318 4319 4320You can check the success of the download using the 'iminfo' command; 4321this includes a checksum verification so you can be sure no data 4322corruption happened: 4323 4324 => imi 40100000 4325 4326 ## Checking Image at 40100000 ... 4327 Image Name: 2.2.13 for initrd on TQM850L 4328 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4329 Data Size: 335725 Bytes = 327 kB = 0 MB 4330 Load Address: 00000000 4331 Entry Point: 0000000c 4332 Verifying Checksum ... OK 4333 4334 4335Boot Linux: 4336----------- 4337 4338The "bootm" command is used to boot an application that is stored in 4339memory (RAM or Flash). In case of a Linux kernel image, the contents 4340of the "bootargs" environment variable is passed to the kernel as 4341parameters. You can check and modify this variable using the 4342"printenv" and "setenv" commands: 4343 4344 4345 => printenv bootargs 4346 bootargs=root=/dev/ram 4347 4348 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4349 4350 => printenv bootargs 4351 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4352 4353 => bootm 40020000 4354 ## Booting Linux kernel at 40020000 ... 4355 Image Name: 2.2.13 for NFS on TQM850L 4356 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4357 Data Size: 381681 Bytes = 372 kB = 0 MB 4358 Load Address: 00000000 4359 Entry Point: 0000000c 4360 Verifying Checksum ... OK 4361 Uncompressing Kernel Image ... OK 4362 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 4363 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4364 time_init: decrementer frequency = 187500000/60 4365 Calibrating delay loop... 49.77 BogoMIPS 4366 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4367 ... 4368 4369If you want to boot a Linux kernel with initial RAM disk, you pass 4370the memory addresses of both the kernel and the initrd image (PPBCOOT 4371format!) to the "bootm" command: 4372 4373 => imi 40100000 40200000 4374 4375 ## Checking Image at 40100000 ... 4376 Image Name: 2.2.13 for initrd on TQM850L 4377 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4378 Data Size: 335725 Bytes = 327 kB = 0 MB 4379 Load Address: 00000000 4380 Entry Point: 0000000c 4381 Verifying Checksum ... OK 4382 4383 ## Checking Image at 40200000 ... 4384 Image Name: Simple Ramdisk Image 4385 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4386 Data Size: 566530 Bytes = 553 kB = 0 MB 4387 Load Address: 00000000 4388 Entry Point: 00000000 4389 Verifying Checksum ... OK 4390 4391 => bootm 40100000 40200000 4392 ## Booting Linux kernel at 40100000 ... 4393 Image Name: 2.2.13 for initrd on TQM850L 4394 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4395 Data Size: 335725 Bytes = 327 kB = 0 MB 4396 Load Address: 00000000 4397 Entry Point: 0000000c 4398 Verifying Checksum ... OK 4399 Uncompressing Kernel Image ... OK 4400 ## Loading RAMDisk Image at 40200000 ... 4401 Image Name: Simple Ramdisk Image 4402 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4403 Data Size: 566530 Bytes = 553 kB = 0 MB 4404 Load Address: 00000000 4405 Entry Point: 00000000 4406 Verifying Checksum ... OK 4407 Loading Ramdisk ... OK 4408 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 4409 Boot arguments: root=/dev/ram 4410 time_init: decrementer frequency = 187500000/60 4411 Calibrating delay loop... 49.77 BogoMIPS 4412 ... 4413 RAMDISK: Compressed image found at block 0 4414 VFS: Mounted root (ext2 filesystem). 4415 4416 bash# 4417 4418Boot Linux and pass a flat device tree: 4419----------- 4420 4421First, U-Boot must be compiled with the appropriate defines. See the section 4422titled "Linux Kernel Interface" above for a more in depth explanation. The 4423following is an example of how to start a kernel and pass an updated 4424flat device tree: 4425 4426=> print oftaddr 4427oftaddr=0x300000 4428=> print oft 4429oft=oftrees/mpc8540ads.dtb 4430=> tftp $oftaddr $oft 4431Speed: 1000, full duplex 4432Using TSEC0 device 4433TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4434Filename 'oftrees/mpc8540ads.dtb'. 4435Load address: 0x300000 4436Loading: # 4437done 4438Bytes transferred = 4106 (100a hex) 4439=> tftp $loadaddr $bootfile 4440Speed: 1000, full duplex 4441Using TSEC0 device 4442TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4443Filename 'uImage'. 4444Load address: 0x200000 4445Loading:############ 4446done 4447Bytes transferred = 1029407 (fb51f hex) 4448=> print loadaddr 4449loadaddr=200000 4450=> print oftaddr 4451oftaddr=0x300000 4452=> bootm $loadaddr - $oftaddr 4453## Booting image at 00200000 ... 4454 Image Name: Linux-2.6.17-dirty 4455 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4456 Data Size: 1029343 Bytes = 1005.2 kB 4457 Load Address: 00000000 4458 Entry Point: 00000000 4459 Verifying Checksum ... OK 4460 Uncompressing Kernel Image ... OK 4461Booting using flat device tree at 0x300000 4462Using MPC85xx ADS machine description 4463Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4464[snip] 4465 4466 4467More About U-Boot Image Types: 4468------------------------------ 4469 4470U-Boot supports the following image types: 4471 4472 "Standalone Programs" are directly runnable in the environment 4473 provided by U-Boot; it is expected that (if they behave 4474 well) you can continue to work in U-Boot after return from 4475 the Standalone Program. 4476 "OS Kernel Images" are usually images of some Embedded OS which 4477 will take over control completely. Usually these programs 4478 will install their own set of exception handlers, device 4479 drivers, set up the MMU, etc. - this means, that you cannot 4480 expect to re-enter U-Boot except by resetting the CPU. 4481 "RAMDisk Images" are more or less just data blocks, and their 4482 parameters (address, size) are passed to an OS kernel that is 4483 being started. 4484 "Multi-File Images" contain several images, typically an OS 4485 (Linux) kernel image and one or more data images like 4486 RAMDisks. This construct is useful for instance when you want 4487 to boot over the network using BOOTP etc., where the boot 4488 server provides just a single image file, but you want to get 4489 for instance an OS kernel and a RAMDisk image. 4490 4491 "Multi-File Images" start with a list of image sizes, each 4492 image size (in bytes) specified by an "uint32_t" in network 4493 byte order. This list is terminated by an "(uint32_t)0". 4494 Immediately after the terminating 0 follow the images, one by 4495 one, all aligned on "uint32_t" boundaries (size rounded up to 4496 a multiple of 4 bytes). 4497 4498 "Firmware Images" are binary images containing firmware (like 4499 U-Boot or FPGA images) which usually will be programmed to 4500 flash memory. 4501 4502 "Script files" are command sequences that will be executed by 4503 U-Boot's command interpreter; this feature is especially 4504 useful when you configure U-Boot to use a real shell (hush) 4505 as command interpreter. 4506 4507Booting the Linux zImage: 4508------------------------- 4509 4510On some platforms, it's possible to boot Linux zImage. This is done 4511using the "bootz" command. The syntax of "bootz" command is the same 4512as the syntax of "bootm" command. 4513 4514Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4515kernel with raw initrd images. The syntax is slightly different, the 4516address of the initrd must be augmented by it's size, in the following 4517format: "<initrd addres>:<initrd size>". 4518 4519 4520Standalone HOWTO: 4521================= 4522 4523One of the features of U-Boot is that you can dynamically load and 4524run "standalone" applications, which can use some resources of 4525U-Boot like console I/O functions or interrupt services. 4526 4527Two simple examples are included with the sources: 4528 4529"Hello World" Demo: 4530------------------- 4531 4532'examples/hello_world.c' contains a small "Hello World" Demo 4533application; it is automatically compiled when you build U-Boot. 4534It's configured to run at address 0x00040004, so you can play with it 4535like that: 4536 4537 => loads 4538 ## Ready for S-Record download ... 4539 ~>examples/hello_world.srec 4540 1 2 3 4 5 6 7 8 9 10 11 ... 4541 [file transfer complete] 4542 [connected] 4543 ## Start Addr = 0x00040004 4544 4545 => go 40004 Hello World! This is a test. 4546 ## Starting application at 0x00040004 ... 4547 Hello World 4548 argc = 7 4549 argv[0] = "40004" 4550 argv[1] = "Hello" 4551 argv[2] = "World!" 4552 argv[3] = "This" 4553 argv[4] = "is" 4554 argv[5] = "a" 4555 argv[6] = "test." 4556 argv[7] = "<NULL>" 4557 Hit any key to exit ... 4558 4559 ## Application terminated, rc = 0x0 4560 4561Another example, which demonstrates how to register a CPM interrupt 4562handler with the U-Boot code, can be found in 'examples/timer.c'. 4563Here, a CPM timer is set up to generate an interrupt every second. 4564The interrupt service routine is trivial, just printing a '.' 4565character, but this is just a demo program. The application can be 4566controlled by the following keys: 4567 4568 ? - print current values og the CPM Timer registers 4569 b - enable interrupts and start timer 4570 e - stop timer and disable interrupts 4571 q - quit application 4572 4573 => loads 4574 ## Ready for S-Record download ... 4575 ~>examples/timer.srec 4576 1 2 3 4 5 6 7 8 9 10 11 ... 4577 [file transfer complete] 4578 [connected] 4579 ## Start Addr = 0x00040004 4580 4581 => go 40004 4582 ## Starting application at 0x00040004 ... 4583 TIMERS=0xfff00980 4584 Using timer 1 4585 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4586 4587Hit 'b': 4588 [q, b, e, ?] Set interval 1000000 us 4589 Enabling timer 4590Hit '?': 4591 [q, b, e, ?] ........ 4592 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4593Hit '?': 4594 [q, b, e, ?] . 4595 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4596Hit '?': 4597 [q, b, e, ?] . 4598 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4599Hit '?': 4600 [q, b, e, ?] . 4601 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4602Hit 'e': 4603 [q, b, e, ?] ...Stopping timer 4604Hit 'q': 4605 [q, b, e, ?] ## Application terminated, rc = 0x0 4606 4607 4608Minicom warning: 4609================ 4610 4611Over time, many people have reported problems when trying to use the 4612"minicom" terminal emulation program for serial download. I (wd) 4613consider minicom to be broken, and recommend not to use it. Under 4614Unix, I recommend to use C-Kermit for general purpose use (and 4615especially for kermit binary protocol download ("loadb" command), and 4616use "cu" for S-Record download ("loads" command). See 4617http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4618for help with kermit. 4619 4620 4621Nevertheless, if you absolutely want to use it try adding this 4622configuration to your "File transfer protocols" section: 4623 4624 Name Program Name U/D FullScr IO-Red. Multi 4625 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4626 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4627 4628 4629NetBSD Notes: 4630============= 4631 4632Starting at version 0.9.2, U-Boot supports NetBSD both as host 4633(build U-Boot) and target system (boots NetBSD/mpc8xx). 4634 4635Building requires a cross environment; it is known to work on 4636NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4637need gmake since the Makefiles are not compatible with BSD make). 4638Note that the cross-powerpc package does not install include files; 4639attempting to build U-Boot will fail because <machine/ansi.h> is 4640missing. This file has to be installed and patched manually: 4641 4642 # cd /usr/pkg/cross/powerpc-netbsd/include 4643 # mkdir powerpc 4644 # ln -s powerpc machine 4645 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4646 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4647 4648Native builds *don't* work due to incompatibilities between native 4649and U-Boot include files. 4650 4651Booting assumes that (the first part of) the image booted is a 4652stage-2 loader which in turn loads and then invokes the kernel 4653proper. Loader sources will eventually appear in the NetBSD source 4654tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4655meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4656 4657 4658Implementation Internals: 4659========================= 4660 4661The following is not intended to be a complete description of every 4662implementation detail. However, it should help to understand the 4663inner workings of U-Boot and make it easier to port it to custom 4664hardware. 4665 4666 4667Initial Stack, Global Data: 4668--------------------------- 4669 4670The implementation of U-Boot is complicated by the fact that U-Boot 4671starts running out of ROM (flash memory), usually without access to 4672system RAM (because the memory controller is not initialized yet). 4673This means that we don't have writable Data or BSS segments, and BSS 4674is not initialized as zero. To be able to get a C environment working 4675at all, we have to allocate at least a minimal stack. Implementation 4676options for this are defined and restricted by the CPU used: Some CPU 4677models provide on-chip memory (like the IMMR area on MPC8xx and 4678MPC826x processors), on others (parts of) the data cache can be 4679locked as (mis-) used as memory, etc. 4680 4681 Chris Hallinan posted a good summary of these issues to the 4682 U-Boot mailing list: 4683 4684 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4685 From: "Chris Hallinan" <clh@net1plus.com> 4686 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4687 ... 4688 4689 Correct me if I'm wrong, folks, but the way I understand it 4690 is this: Using DCACHE as initial RAM for Stack, etc, does not 4691 require any physical RAM backing up the cache. The cleverness 4692 is that the cache is being used as a temporary supply of 4693 necessary storage before the SDRAM controller is setup. It's 4694 beyond the scope of this list to explain the details, but you 4695 can see how this works by studying the cache architecture and 4696 operation in the architecture and processor-specific manuals. 4697 4698 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4699 is another option for the system designer to use as an 4700 initial stack/RAM area prior to SDRAM being available. Either 4701 option should work for you. Using CS 4 should be fine if your 4702 board designers haven't used it for something that would 4703 cause you grief during the initial boot! It is frequently not 4704 used. 4705 4706 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4707 with your processor/board/system design. The default value 4708 you will find in any recent u-boot distribution in 4709 walnut.h should work for you. I'd set it to a value larger 4710 than your SDRAM module. If you have a 64MB SDRAM module, set 4711 it above 400_0000. Just make sure your board has no resources 4712 that are supposed to respond to that address! That code in 4713 start.S has been around a while and should work as is when 4714 you get the config right. 4715 4716 -Chris Hallinan 4717 DS4.COM, Inc. 4718 4719It is essential to remember this, since it has some impact on the C 4720code for the initialization procedures: 4721 4722* Initialized global data (data segment) is read-only. Do not attempt 4723 to write it. 4724 4725* Do not use any uninitialized global data (or implicitly initialized 4726 as zero data - BSS segment) at all - this is undefined, initiali- 4727 zation is performed later (when relocating to RAM). 4728 4729* Stack space is very limited. Avoid big data buffers or things like 4730 that. 4731 4732Having only the stack as writable memory limits means we cannot use 4733normal global data to share information between the code. But it 4734turned out that the implementation of U-Boot can be greatly 4735simplified by making a global data structure (gd_t) available to all 4736functions. We could pass a pointer to this data as argument to _all_ 4737functions, but this would bloat the code. Instead we use a feature of 4738the GCC compiler (Global Register Variables) to share the data: we 4739place a pointer (gd) to the global data into a register which we 4740reserve for this purpose. 4741 4742When choosing a register for such a purpose we are restricted by the 4743relevant (E)ABI specifications for the current architecture, and by 4744GCC's implementation. 4745 4746For PowerPC, the following registers have specific use: 4747 R1: stack pointer 4748 R2: reserved for system use 4749 R3-R4: parameter passing and return values 4750 R5-R10: parameter passing 4751 R13: small data area pointer 4752 R30: GOT pointer 4753 R31: frame pointer 4754 4755 (U-Boot also uses R12 as internal GOT pointer. r12 4756 is a volatile register so r12 needs to be reset when 4757 going back and forth between asm and C) 4758 4759 ==> U-Boot will use R2 to hold a pointer to the global data 4760 4761 Note: on PPC, we could use a static initializer (since the 4762 address of the global data structure is known at compile time), 4763 but it turned out that reserving a register results in somewhat 4764 smaller code - although the code savings are not that big (on 4765 average for all boards 752 bytes for the whole U-Boot image, 4766 624 text + 127 data). 4767 4768On ARM, the following registers are used: 4769 4770 R0: function argument word/integer result 4771 R1-R3: function argument word 4772 R9: platform specific 4773 R10: stack limit (used only if stack checking is enabled) 4774 R11: argument (frame) pointer 4775 R12: temporary workspace 4776 R13: stack pointer 4777 R14: link register 4778 R15: program counter 4779 4780 ==> U-Boot will use R9 to hold a pointer to the global data 4781 4782 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4783 4784On Nios II, the ABI is documented here: 4785 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4786 4787 ==> U-Boot will use gp to hold a pointer to the global data 4788 4789 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4790 to access small data sections, so gp is free. 4791 4792On NDS32, the following registers are used: 4793 4794 R0-R1: argument/return 4795 R2-R5: argument 4796 R15: temporary register for assembler 4797 R16: trampoline register 4798 R28: frame pointer (FP) 4799 R29: global pointer (GP) 4800 R30: link register (LP) 4801 R31: stack pointer (SP) 4802 PC: program counter (PC) 4803 4804 ==> U-Boot will use R10 to hold a pointer to the global data 4805 4806NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4807or current versions of GCC may "optimize" the code too much. 4808 4809On RISC-V, the following registers are used: 4810 4811 x0: hard-wired zero (zero) 4812 x1: return address (ra) 4813 x2: stack pointer (sp) 4814 x3: global pointer (gp) 4815 x4: thread pointer (tp) 4816 x5: link register (t0) 4817 x8: frame pointer (fp) 4818 x10-x11: arguments/return values (a0-1) 4819 x12-x17: arguments (a2-7) 4820 x28-31: temporaries (t3-6) 4821 pc: program counter (pc) 4822 4823 ==> U-Boot will use gp to hold a pointer to the global data 4824 4825Memory Management: 4826------------------ 4827 4828U-Boot runs in system state and uses physical addresses, i.e. the 4829MMU is not used either for address mapping nor for memory protection. 4830 4831The available memory is mapped to fixed addresses using the memory 4832controller. In this process, a contiguous block is formed for each 4833memory type (Flash, SDRAM, SRAM), even when it consists of several 4834physical memory banks. 4835 4836U-Boot is installed in the first 128 kB of the first Flash bank (on 4837TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4838booting and sizing and initializing DRAM, the code relocates itself 4839to the upper end of DRAM. Immediately below the U-Boot code some 4840memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4841configuration setting]. Below that, a structure with global Board 4842Info data is placed, followed by the stack (growing downward). 4843 4844Additionally, some exception handler code is copied to the low 8 kB 4845of DRAM (0x00000000 ... 0x00001FFF). 4846 4847So a typical memory configuration with 16 MB of DRAM could look like 4848this: 4849 4850 0x0000 0000 Exception Vector code 4851 : 4852 0x0000 1FFF 4853 0x0000 2000 Free for Application Use 4854 : 4855 : 4856 4857 : 4858 : 4859 0x00FB FF20 Monitor Stack (Growing downward) 4860 0x00FB FFAC Board Info Data and permanent copy of global data 4861 0x00FC 0000 Malloc Arena 4862 : 4863 0x00FD FFFF 4864 0x00FE 0000 RAM Copy of Monitor Code 4865 ... eventually: LCD or video framebuffer 4866 ... eventually: pRAM (Protected RAM - unchanged by reset) 4867 0x00FF FFFF [End of RAM] 4868 4869 4870System Initialization: 4871---------------------- 4872 4873In the reset configuration, U-Boot starts at the reset entry point 4874(on most PowerPC systems at address 0x00000100). Because of the reset 4875configuration for CS0# this is a mirror of the on board Flash memory. 4876To be able to re-map memory U-Boot then jumps to its link address. 4877To be able to implement the initialization code in C, a (small!) 4878initial stack is set up in the internal Dual Ported RAM (in case CPUs 4879which provide such a feature like), or in a locked part of the data 4880cache. After that, U-Boot initializes the CPU core, the caches and 4881the SIU. 4882 4883Next, all (potentially) available memory banks are mapped using a 4884preliminary mapping. For example, we put them on 512 MB boundaries 4885(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4886on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4887programmed for SDRAM access. Using the temporary configuration, a 4888simple memory test is run that determines the size of the SDRAM 4889banks. 4890 4891When there is more than one SDRAM bank, and the banks are of 4892different size, the largest is mapped first. For equal size, the first 4893bank (CS2#) is mapped first. The first mapping is always for address 48940x00000000, with any additional banks following immediately to create 4895contiguous memory starting from 0. 4896 4897Then, the monitor installs itself at the upper end of the SDRAM area 4898and allocates memory for use by malloc() and for the global Board 4899Info data; also, the exception vector code is copied to the low RAM 4900pages, and the final stack is set up. 4901 4902Only after this relocation will you have a "normal" C environment; 4903until that you are restricted in several ways, mostly because you are 4904running from ROM, and because the code will have to be relocated to a 4905new address in RAM. 4906 4907 4908U-Boot Porting Guide: 4909---------------------- 4910 4911[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4912list, October 2002] 4913 4914 4915int main(int argc, char *argv[]) 4916{ 4917 sighandler_t no_more_time; 4918 4919 signal(SIGALRM, no_more_time); 4920 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4921 4922 if (available_money > available_manpower) { 4923 Pay consultant to port U-Boot; 4924 return 0; 4925 } 4926 4927 Download latest U-Boot source; 4928 4929 Subscribe to u-boot mailing list; 4930 4931 if (clueless) 4932 email("Hi, I am new to U-Boot, how do I get started?"); 4933 4934 while (learning) { 4935 Read the README file in the top level directory; 4936 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4937 Read applicable doc/*.README; 4938 Read the source, Luke; 4939 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4940 } 4941 4942 if (available_money > toLocalCurrency ($2500)) 4943 Buy a BDI3000; 4944 else 4945 Add a lot of aggravation and time; 4946 4947 if (a similar board exists) { /* hopefully... */ 4948 cp -a board/<similar> board/<myboard> 4949 cp include/configs/<similar>.h include/configs/<myboard>.h 4950 } else { 4951 Create your own board support subdirectory; 4952 Create your own board include/configs/<myboard>.h file; 4953 } 4954 Edit new board/<myboard> files 4955 Edit new include/configs/<myboard>.h 4956 4957 while (!accepted) { 4958 while (!running) { 4959 do { 4960 Add / modify source code; 4961 } until (compiles); 4962 Debug; 4963 if (clueless) 4964 email("Hi, I am having problems..."); 4965 } 4966 Send patch file to the U-Boot email list; 4967 if (reasonable critiques) 4968 Incorporate improvements from email list code review; 4969 else 4970 Defend code as written; 4971 } 4972 4973 return 0; 4974} 4975 4976void no_more_time (int sig) 4977{ 4978 hire_a_guru(); 4979} 4980 4981 4982Coding Standards: 4983----------------- 4984 4985All contributions to U-Boot should conform to the Linux kernel 4986coding style; see the kernel coding style guide at 4987https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 4988script "scripts/Lindent" in your Linux kernel source directory. 4989 4990Source files originating from a different project (for example the 4991MTD subsystem) are generally exempt from these guidelines and are not 4992reformatted to ease subsequent migration to newer versions of those 4993sources. 4994 4995Please note that U-Boot is implemented in C (and to some small parts in 4996Assembler); no C++ is used, so please do not use C++ style comments (//) 4997in your code. 4998 4999Please also stick to the following formatting rules: 5000- remove any trailing white space 5001- use TAB characters for indentation and vertical alignment, not spaces 5002- make sure NOT to use DOS '\r\n' line feeds 5003- do not add more than 2 consecutive empty lines to source files 5004- do not add trailing empty lines to source files 5005 5006Submissions which do not conform to the standards may be returned 5007with a request to reformat the changes. 5008 5009 5010Submitting Patches: 5011------------------- 5012 5013Since the number of patches for U-Boot is growing, we need to 5014establish some rules. Submissions which do not conform to these rules 5015may be rejected, even when they contain important and valuable stuff. 5016 5017Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5018 5019Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5020see https://lists.denx.de/listinfo/u-boot 5021 5022When you send a patch, please include the following information with 5023it: 5024 5025* For bug fixes: a description of the bug and how your patch fixes 5026 this bug. Please try to include a way of demonstrating that the 5027 patch actually fixes something. 5028 5029* For new features: a description of the feature and your 5030 implementation. 5031 5032* A CHANGELOG entry as plaintext (separate from the patch) 5033 5034* For major contributions, add a MAINTAINERS file with your 5035 information and associated file and directory references. 5036 5037* When you add support for a new board, don't forget to add a 5038 maintainer e-mail address to the boards.cfg file, too. 5039 5040* If your patch adds new configuration options, don't forget to 5041 document these in the README file. 5042 5043* The patch itself. If you are using git (which is *strongly* 5044 recommended) you can easily generate the patch using the 5045 "git format-patch". If you then use "git send-email" to send it to 5046 the U-Boot mailing list, you will avoid most of the common problems 5047 with some other mail clients. 5048 5049 If you cannot use git, use "diff -purN OLD NEW". If your version of 5050 diff does not support these options, then get the latest version of 5051 GNU diff. 5052 5053 The current directory when running this command shall be the parent 5054 directory of the U-Boot source tree (i. e. please make sure that 5055 your patch includes sufficient directory information for the 5056 affected files). 5057 5058 We prefer patches as plain text. MIME attachments are discouraged, 5059 and compressed attachments must not be used. 5060 5061* If one logical set of modifications affects or creates several 5062 files, all these changes shall be submitted in a SINGLE patch file. 5063 5064* Changesets that contain different, unrelated modifications shall be 5065 submitted as SEPARATE patches, one patch per changeset. 5066 5067 5068Notes: 5069 5070* Before sending the patch, run the buildman script on your patched 5071 source tree and make sure that no errors or warnings are reported 5072 for any of the boards. 5073 5074* Keep your modifications to the necessary minimum: A patch 5075 containing several unrelated changes or arbitrary reformats will be 5076 returned with a request to re-formatting / split it. 5077 5078* If you modify existing code, make sure that your new code does not 5079 add to the memory footprint of the code ;-) Small is beautiful! 5080 When adding new features, these should compile conditionally only 5081 (using #ifdef), and the resulting code with the new feature 5082 disabled must not need more memory than the old code without your 5083 modification. 5084 5085* Remember that there is a size limit of 100 kB per message on the 5086 u-boot mailing list. Bigger patches will be moderated. If they are 5087 reasonable and not too big, they will be acknowledged. But patches 5088 bigger than the size limit should be avoided. 5089