1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /m68k Files generic to m68k architecture 140 /microblaze Files generic to microblaze architecture 141 /mips Files generic to MIPS architecture 142 /nds32 Files generic to NDS32 architecture 143 /nios2 Files generic to Altera NIOS2 architecture 144 /openrisc Files generic to OpenRISC architecture 145 /powerpc Files generic to PowerPC architecture 146 /riscv Files generic to RISC-V architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316- ARM Platform Bus Type(CCI): 317 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which 318 provides full cache coherency between two clusters of multi-core 319 CPUs and I/O coherency for devices and I/O masters 320 321 CONFIG_SYS_FSL_HAS_CCI400 322 323 Defined For SoC that has cache coherent interconnect 324 CCN-400 325 326 CONFIG_SYS_FSL_HAS_CCN504 327 328 Defined for SoC that has cache coherent interconnect CCN-504 329 330The following options need to be configured: 331 332- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 333 334- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 335 336- Marvell Family Member 337 CONFIG_SYS_MVFS - define it if you want to enable 338 multiple fs option at one time 339 for marvell soc family 340 341- 85xx CPU Options: 342 CONFIG_SYS_PPC64 343 344 Specifies that the core is a 64-bit PowerPC implementation (implements 345 the "64" category of the Power ISA). This is necessary for ePAPR 346 compliance, among other possible reasons. 347 348 CONFIG_SYS_FSL_TBCLK_DIV 349 350 Defines the core time base clock divider ratio compared to the 351 system clock. On most PQ3 devices this is 8, on newer QorIQ 352 devices it can be 16 or 32. The ratio varies from SoC to Soc. 353 354 CONFIG_SYS_FSL_PCIE_COMPAT 355 356 Defines the string to utilize when trying to match PCIe device 357 tree nodes for the given platform. 358 359 CONFIG_SYS_FSL_ERRATUM_A004510 360 361 Enables a workaround for erratum A004510. If set, 362 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 363 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 364 365 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 366 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 367 368 Defines one or two SoC revisions (low 8 bits of SVR) 369 for which the A004510 workaround should be applied. 370 371 The rest of SVR is either not relevant to the decision 372 of whether the erratum is present (e.g. p2040 versus 373 p2041) or is implied by the build target, which controls 374 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 375 376 See Freescale App Note 4493 for more information about 377 this erratum. 378 379 CONFIG_A003399_NOR_WORKAROUND 380 Enables a workaround for IFC erratum A003399. It is only 381 required during NOR boot. 382 383 CONFIG_A008044_WORKAROUND 384 Enables a workaround for T1040/T1042 erratum A008044. It is only 385 required during NAND boot and valid for Rev 1.0 SoC revision 386 387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 388 389 This is the value to write into CCSR offset 0x18600 390 according to the A004510 workaround. 391 392 CONFIG_SYS_FSL_DSP_DDR_ADDR 393 This value denotes start offset of DDR memory which is 394 connected exclusively to the DSP cores. 395 396 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 397 This value denotes start offset of M2 memory 398 which is directly connected to the DSP core. 399 400 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 401 This value denotes start offset of M3 memory which is directly 402 connected to the DSP core. 403 404 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 405 This value denotes start offset of DSP CCSR space. 406 407 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 408 Single Source Clock is clocking mode present in some of FSL SoC's. 409 In this mode, a single differential clock is used to supply 410 clocks to the sysclock, ddrclock and usbclock. 411 412 CONFIG_SYS_CPC_REINIT_F 413 This CONFIG is defined when the CPC is configured as SRAM at the 414 time of U-Boot entry and is required to be re-initialized. 415 416 CONFIG_DEEP_SLEEP 417 Indicates this SoC supports deep sleep feature. If deep sleep is 418 supported, core will start to execute uboot when wakes up. 419 420- Generic CPU options: 421 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 422 423 Defines the endianess of the CPU. Implementation of those 424 values is arch specific. 425 426 CONFIG_SYS_FSL_DDR 427 Freescale DDR driver in use. This type of DDR controller is 428 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 429 SoCs. 430 431 CONFIG_SYS_FSL_DDR_ADDR 432 Freescale DDR memory-mapped register base. 433 434 CONFIG_SYS_FSL_DDR_EMU 435 Specify emulator support for DDR. Some DDR features such as 436 deskew training are not available. 437 438 CONFIG_SYS_FSL_DDRC_GEN1 439 Freescale DDR1 controller. 440 441 CONFIG_SYS_FSL_DDRC_GEN2 442 Freescale DDR2 controller. 443 444 CONFIG_SYS_FSL_DDRC_GEN3 445 Freescale DDR3 controller. 446 447 CONFIG_SYS_FSL_DDRC_GEN4 448 Freescale DDR4 controller. 449 450 CONFIG_SYS_FSL_DDRC_ARM_GEN3 451 Freescale DDR3 controller for ARM-based SoCs. 452 453 CONFIG_SYS_FSL_DDR1 454 Board config to use DDR1. It can be enabled for SoCs with 455 Freescale DDR1 or DDR2 controllers, depending on the board 456 implemetation. 457 458 CONFIG_SYS_FSL_DDR2 459 Board config to use DDR2. It can be enabled for SoCs with 460 Freescale DDR2 or DDR3 controllers, depending on the board 461 implementation. 462 463 CONFIG_SYS_FSL_DDR3 464 Board config to use DDR3. It can be enabled for SoCs with 465 Freescale DDR3 or DDR3L controllers. 466 467 CONFIG_SYS_FSL_DDR3L 468 Board config to use DDR3L. It can be enabled for SoCs with 469 DDR3L controllers. 470 471 CONFIG_SYS_FSL_DDR4 472 Board config to use DDR4. It can be enabled for SoCs with 473 DDR4 controllers. 474 475 CONFIG_SYS_FSL_IFC_BE 476 Defines the IFC controller register space as Big Endian 477 478 CONFIG_SYS_FSL_IFC_LE 479 Defines the IFC controller register space as Little Endian 480 481 CONFIG_SYS_FSL_IFC_CLK_DIV 482 Defines divider of platform clock(clock input to IFC controller). 483 484 CONFIG_SYS_FSL_LBC_CLK_DIV 485 Defines divider of platform clock(clock input to eLBC controller). 486 487 CONFIG_SYS_FSL_PBL_PBI 488 It enables addition of RCW (Power on reset configuration) in built image. 489 Please refer doc/README.pblimage for more details 490 491 CONFIG_SYS_FSL_PBL_RCW 492 It adds PBI(pre-boot instructions) commands in u-boot build image. 493 PBI commands can be used to configure SoC before it starts the execution. 494 Please refer doc/README.pblimage for more details 495 496 CONFIG_SPL_FSL_PBL 497 It adds a target to create boot binary having SPL binary in PBI format 498 concatenated with u-boot binary. 499 500 CONFIG_SYS_FSL_DDR_BE 501 Defines the DDR controller register space as Big Endian 502 503 CONFIG_SYS_FSL_DDR_LE 504 Defines the DDR controller register space as Little Endian 505 506 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 507 Physical address from the view of DDR controllers. It is the 508 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 509 it could be different for ARM SoCs. 510 511 CONFIG_SYS_FSL_DDR_INTLV_256B 512 DDR controller interleaving on 256-byte. This is a special 513 interleaving mode, handled by Dickens for Freescale layerscape 514 SoCs with ARM core. 515 516 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 517 Number of controllers used as main memory. 518 519 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 520 Number of controllers used for other than main memory. 521 522 CONFIG_SYS_FSL_HAS_DP_DDR 523 Defines the SoC has DP-DDR used for DPAA. 524 525 CONFIG_SYS_FSL_SEC_BE 526 Defines the SEC controller register space as Big Endian 527 528 CONFIG_SYS_FSL_SEC_LE 529 Defines the SEC controller register space as Little Endian 530 531- MIPS CPU options: 532 CONFIG_SYS_INIT_SP_OFFSET 533 534 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 535 pointer. This is needed for the temporary stack before 536 relocation. 537 538 CONFIG_SYS_MIPS_CACHE_MODE 539 540 Cache operation mode for the MIPS CPU. 541 See also arch/mips/include/asm/mipsregs.h. 542 Possible values are: 543 CONF_CM_CACHABLE_NO_WA 544 CONF_CM_CACHABLE_WA 545 CONF_CM_UNCACHED 546 CONF_CM_CACHABLE_NONCOHERENT 547 CONF_CM_CACHABLE_CE 548 CONF_CM_CACHABLE_COW 549 CONF_CM_CACHABLE_CUW 550 CONF_CM_CACHABLE_ACCELERATED 551 552 CONFIG_SYS_XWAY_EBU_BOOTCFG 553 554 Special option for Lantiq XWAY SoCs for booting from NOR flash. 555 See also arch/mips/cpu/mips32/start.S. 556 557 CONFIG_XWAY_SWAP_BYTES 558 559 Enable compilation of tools/xway-swap-bytes needed for Lantiq 560 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 561 be swapped if a flash programmer is used. 562 563- ARM options: 564 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 565 566 Select high exception vectors of the ARM core, e.g., do not 567 clear the V bit of the c1 register of CP15. 568 569 COUNTER_FREQUENCY 570 Generic timer clock source frequency. 571 572 COUNTER_FREQUENCY_REAL 573 Generic timer clock source frequency if the real clock is 574 different from COUNTER_FREQUENCY, and can only be determined 575 at run time. 576 577- Tegra SoC options: 578 CONFIG_TEGRA_SUPPORT_NON_SECURE 579 580 Support executing U-Boot in non-secure (NS) mode. Certain 581 impossible actions will be skipped if the CPU is in NS mode, 582 such as ARM architectural timer initialization. 583 584- Linux Kernel Interface: 585 CONFIG_CLOCKS_IN_MHZ 586 587 U-Boot stores all clock information in Hz 588 internally. For binary compatibility with older Linux 589 kernels (which expect the clocks passed in the 590 bd_info data to be in MHz) the environment variable 591 "clocks_in_mhz" can be defined so that U-Boot 592 converts clock data to MHZ before passing it to the 593 Linux kernel. 594 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 595 "clocks_in_mhz=1" is automatically included in the 596 default environment. 597 598 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 599 600 When transferring memsize parameter to Linux, some versions 601 expect it to be in bytes, others in MB. 602 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 603 604 CONFIG_OF_LIBFDT 605 606 New kernel versions are expecting firmware settings to be 607 passed using flattened device trees (based on open firmware 608 concepts). 609 610 CONFIG_OF_LIBFDT 611 * New libfdt-based support 612 * Adds the "fdt" command 613 * The bootm command automatically updates the fdt 614 615 OF_TBCLK - The timebase frequency. 616 OF_STDOUT_PATH - The path to the console device 617 618 boards with QUICC Engines require OF_QE to set UCC MAC 619 addresses 620 621 CONFIG_OF_BOARD_SETUP 622 623 Board code has addition modification that it wants to make 624 to the flat device tree before handing it off to the kernel 625 626 CONFIG_OF_SYSTEM_SETUP 627 628 Other code has addition modification that it wants to make 629 to the flat device tree before handing it off to the kernel. 630 This causes ft_system_setup() to be called before booting 631 the kernel. 632 633 CONFIG_OF_IDE_FIXUP 634 635 U-Boot can detect if an IDE device is present or not. 636 If not, and this new config option is activated, U-Boot 637 removes the ATA node from the DTS before booting Linux, 638 so the Linux IDE driver does not probe the device and 639 crash. This is needed for buggy hardware (uc101) where 640 no pull down resistor is connected to the signal IDE5V_DD7. 641 642 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 643 644 This setting is mandatory for all boards that have only one 645 machine type and must be used to specify the machine type 646 number as it appears in the ARM machine registry 647 (see http://www.arm.linux.org.uk/developer/machines/). 648 Only boards that have multiple machine types supported 649 in a single configuration file and the machine type is 650 runtime discoverable, do not have to use this setting. 651 652- vxWorks boot parameters: 653 654 bootvx constructs a valid bootline using the following 655 environments variables: bootdev, bootfile, ipaddr, netmask, 656 serverip, gatewayip, hostname, othbootargs. 657 It loads the vxWorks image pointed bootfile. 658 659 Note: If a "bootargs" environment is defined, it will overwride 660 the defaults discussed just above. 661 662- Cache Configuration: 663 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 664 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 665 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 666 667- Cache Configuration for ARM: 668 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 669 controller 670 CONFIG_SYS_PL310_BASE - Physical base address of PL310 671 controller register space 672 673- Serial Ports: 674 CONFIG_PL010_SERIAL 675 676 Define this if you want support for Amba PrimeCell PL010 UARTs. 677 678 CONFIG_PL011_SERIAL 679 680 Define this if you want support for Amba PrimeCell PL011 UARTs. 681 682 CONFIG_PL011_CLOCK 683 684 If you have Amba PrimeCell PL011 UARTs, set this variable to 685 the clock speed of the UARTs. 686 687 CONFIG_PL01x_PORTS 688 689 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 690 define this to a list of base addresses for each (supported) 691 port. See e.g. include/configs/versatile.h 692 693 CONFIG_SERIAL_HW_FLOW_CONTROL 694 695 Define this variable to enable hw flow control in serial driver. 696 Current user of this option is drivers/serial/nsl16550.c driver 697 698- Console Baudrate: 699 CONFIG_BAUDRATE - in bps 700 Select one of the baudrates listed in 701 CONFIG_SYS_BAUDRATE_TABLE, see below. 702 703- Autoboot Command: 704 CONFIG_BOOTCOMMAND 705 Only needed when CONFIG_BOOTDELAY is enabled; 706 define a command string that is automatically executed 707 when no character is read on the console interface 708 within "Boot Delay" after reset. 709 710 CONFIG_RAMBOOT and CONFIG_NFSBOOT 711 The value of these goes into the environment as 712 "ramboot" and "nfsboot" respectively, and can be used 713 as a convenience, when switching between booting from 714 RAM and NFS. 715 716- Pre-Boot Commands: 717 CONFIG_PREBOOT 718 719 When this option is #defined, the existence of the 720 environment variable "preboot" will be checked 721 immediately before starting the CONFIG_BOOTDELAY 722 countdown and/or running the auto-boot command resp. 723 entering interactive mode. 724 725 This feature is especially useful when "preboot" is 726 automatically generated or modified. For an example 727 see the LWMON board specific code: here "preboot" is 728 modified when the user holds down a certain 729 combination of keys on the (special) keyboard when 730 booting the systems 731 732- Serial Download Echo Mode: 733 CONFIG_LOADS_ECHO 734 If defined to 1, all characters received during a 735 serial download (using the "loads" command) are 736 echoed back. This might be needed by some terminal 737 emulations (like "cu"), but may as well just take 738 time on others. This setting #define's the initial 739 value of the "loads_echo" environment variable. 740 741- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 742 CONFIG_KGDB_BAUDRATE 743 Select one of the baudrates listed in 744 CONFIG_SYS_BAUDRATE_TABLE, see below. 745 746- Removal of commands 747 If no commands are needed to boot, you can disable 748 CONFIG_CMDLINE to remove them. In this case, the command line 749 will not be available, and when U-Boot wants to execute the 750 boot command (on start-up) it will call board_run_command() 751 instead. This can reduce image size significantly for very 752 simple boot procedures. 753 754- Regular expression support: 755 CONFIG_REGEX 756 If this variable is defined, U-Boot is linked against 757 the SLRE (Super Light Regular Expression) library, 758 which adds regex support to some commands, as for 759 example "env grep" and "setexpr". 760 761- Device tree: 762 CONFIG_OF_CONTROL 763 If this variable is defined, U-Boot will use a device tree 764 to configure its devices, instead of relying on statically 765 compiled #defines in the board file. This option is 766 experimental and only available on a few boards. The device 767 tree is available in the global data as gd->fdt_blob. 768 769 U-Boot needs to get its device tree from somewhere. This can 770 be done using one of the three options below: 771 772 CONFIG_OF_EMBED 773 If this variable is defined, U-Boot will embed a device tree 774 binary in its image. This device tree file should be in the 775 board directory and called <soc>-<board>.dts. The binary file 776 is then picked up in board_init_f() and made available through 777 the global data structure as gd->fdt_blob. 778 779 CONFIG_OF_SEPARATE 780 If this variable is defined, U-Boot will build a device tree 781 binary. It will be called u-boot.dtb. Architecture-specific 782 code will locate it at run-time. Generally this works by: 783 784 cat u-boot.bin u-boot.dtb >image.bin 785 786 and in fact, U-Boot does this for you, creating a file called 787 u-boot-dtb.bin which is useful in the common case. You can 788 still use the individual files if you need something more 789 exotic. 790 791 CONFIG_OF_BOARD 792 If this variable is defined, U-Boot will use the device tree 793 provided by the board at runtime instead of embedding one with 794 the image. Only boards defining board_fdt_blob_setup() support 795 this option (see include/fdtdec.h file). 796 797- Watchdog: 798 CONFIG_WATCHDOG 799 If this variable is defined, it enables watchdog 800 support for the SoC. There must be support in the SoC 801 specific code for a watchdog. For the 8xx 802 CPUs, the SIU Watchdog feature is enabled in the SYPCR 803 register. When supported for a specific SoC is 804 available, then no further board specific code should 805 be needed to use it. 806 807 CONFIG_HW_WATCHDOG 808 When using a watchdog circuitry external to the used 809 SoC, then define this variable and provide board 810 specific code for the "hw_watchdog_reset" function. 811 812 CONFIG_AT91_HW_WDT_TIMEOUT 813 specify the timeout in seconds. default 2 seconds. 814 815- Real-Time Clock: 816 817 When CONFIG_CMD_DATE is selected, the type of the RTC 818 has to be selected, too. Define exactly one of the 819 following options: 820 821 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 822 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 823 CONFIG_RTC_MC146818 - use MC146818 RTC 824 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 825 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 826 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 827 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 828 CONFIG_RTC_DS164x - use Dallas DS164x RTC 829 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 830 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 831 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 832 CONFIG_SYS_RV3029_TCR - enable trickle charger on 833 RV3029 RTC. 834 835 Note that if the RTC uses I2C, then the I2C interface 836 must also be configured. See I2C Support, below. 837 838- GPIO Support: 839 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 840 841 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 842 chip-ngpio pairs that tell the PCA953X driver the number of 843 pins supported by a particular chip. 844 845 Note that if the GPIO device uses I2C, then the I2C interface 846 must also be configured. See I2C Support, below. 847 848- I/O tracing: 849 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 850 accesses and can checksum them or write a list of them out 851 to memory. See the 'iotrace' command for details. This is 852 useful for testing device drivers since it can confirm that 853 the driver behaves the same way before and after a code 854 change. Currently this is supported on sandbox and arm. To 855 add support for your architecture, add '#include <iotrace.h>' 856 to the bottom of arch/<arch>/include/asm/io.h and test. 857 858 Example output from the 'iotrace stats' command is below. 859 Note that if the trace buffer is exhausted, the checksum will 860 still continue to operate. 861 862 iotrace is enabled 863 Start: 10000000 (buffer start address) 864 Size: 00010000 (buffer size) 865 Offset: 00000120 (current buffer offset) 866 Output: 10000120 (start + offset) 867 Count: 00000018 (number of trace records) 868 CRC32: 9526fb66 (CRC32 of all trace records) 869 870- Timestamp Support: 871 872 When CONFIG_TIMESTAMP is selected, the timestamp 873 (date and time) of an image is printed by image 874 commands like bootm or iminfo. This option is 875 automatically enabled when you select CONFIG_CMD_DATE . 876 877- Partition Labels (disklabels) Supported: 878 Zero or more of the following: 879 CONFIG_MAC_PARTITION Apple's MacOS partition table. 880 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 881 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 882 bootloader. Note 2TB partition limit; see 883 disk/part_efi.c 884 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 885 886 If IDE or SCSI support is enabled (CONFIG_IDE or 887 CONFIG_SCSI) you must configure support for at 888 least one non-MTD partition type as well. 889 890- IDE Reset method: 891 CONFIG_IDE_RESET_ROUTINE - this is defined in several 892 board configurations files but used nowhere! 893 894 CONFIG_IDE_RESET - is this is defined, IDE Reset will 895 be performed by calling the function 896 ide_set_reset(int reset) 897 which has to be defined in a board specific file 898 899- ATAPI Support: 900 CONFIG_ATAPI 901 902 Set this to enable ATAPI support. 903 904- LBA48 Support 905 CONFIG_LBA48 906 907 Set this to enable support for disks larger than 137GB 908 Also look at CONFIG_SYS_64BIT_LBA. 909 Whithout these , LBA48 support uses 32bit variables and will 'only' 910 support disks up to 2.1TB. 911 912 CONFIG_SYS_64BIT_LBA: 913 When enabled, makes the IDE subsystem use 64bit sector addresses. 914 Default is 32bit. 915 916- SCSI Support: 917 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 918 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 919 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 920 maximum numbers of LUNs, SCSI ID's and target 921 devices. 922 923 The environment variable 'scsidevs' is set to the number of 924 SCSI devices found during the last scan. 925 926- NETWORK Support (PCI): 927 CONFIG_E1000 928 Support for Intel 8254x/8257x gigabit chips. 929 930 CONFIG_E1000_SPI 931 Utility code for direct access to the SPI bus on Intel 8257x. 932 This does not do anything useful unless you set at least one 933 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 934 935 CONFIG_E1000_SPI_GENERIC 936 Allow generic access to the SPI bus on the Intel 8257x, for 937 example with the "sspi" command. 938 939 CONFIG_EEPRO100 940 Support for Intel 82557/82559/82559ER chips. 941 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 942 write routine for first time initialisation. 943 944 CONFIG_TULIP 945 Support for Digital 2114x chips. 946 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 947 modem chip initialisation (KS8761/QS6611). 948 949 CONFIG_NATSEMI 950 Support for National dp83815 chips. 951 952 CONFIG_NS8382X 953 Support for National dp8382[01] gigabit chips. 954 955- NETWORK Support (other): 956 957 CONFIG_DRIVER_AT91EMAC 958 Support for AT91RM9200 EMAC. 959 960 CONFIG_RMII 961 Define this to use reduced MII inteface 962 963 CONFIG_DRIVER_AT91EMAC_QUIET 964 If this defined, the driver is quiet. 965 The driver doen't show link status messages. 966 967 CONFIG_CALXEDA_XGMAC 968 Support for the Calxeda XGMAC device 969 970 CONFIG_LAN91C96 971 Support for SMSC's LAN91C96 chips. 972 973 CONFIG_LAN91C96_USE_32_BIT 974 Define this to enable 32 bit addressing 975 976 CONFIG_SMC91111 977 Support for SMSC's LAN91C111 chip 978 979 CONFIG_SMC91111_BASE 980 Define this to hold the physical address 981 of the device (I/O space) 982 983 CONFIG_SMC_USE_32_BIT 984 Define this if data bus is 32 bits 985 986 CONFIG_SMC_USE_IOFUNCS 987 Define this to use i/o functions instead of macros 988 (some hardware wont work with macros) 989 990 CONFIG_DRIVER_TI_EMAC 991 Support for davinci emac 992 993 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 994 Define this if you have more then 3 PHYs. 995 996 CONFIG_FTGMAC100 997 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 998 999 CONFIG_FTGMAC100_EGIGA 1000 Define this to use GE link update with gigabit PHY. 1001 Define this if FTGMAC100 is connected to gigabit PHY. 1002 If your system has 10/100 PHY only, it might not occur 1003 wrong behavior. Because PHY usually return timeout or 1004 useless data when polling gigabit status and gigabit 1005 control registers. This behavior won't affect the 1006 correctnessof 10/100 link speed update. 1007 1008 CONFIG_SH_ETHER 1009 Support for Renesas on-chip Ethernet controller 1010 1011 CONFIG_SH_ETHER_USE_PORT 1012 Define the number of ports to be used 1013 1014 CONFIG_SH_ETHER_PHY_ADDR 1015 Define the ETH PHY's address 1016 1017 CONFIG_SH_ETHER_CACHE_WRITEBACK 1018 If this option is set, the driver enables cache flush. 1019 1020- PWM Support: 1021 CONFIG_PWM_IMX 1022 Support for PWM module on the imx6. 1023 1024- TPM Support: 1025 CONFIG_TPM 1026 Support TPM devices. 1027 1028 CONFIG_TPM_TIS_INFINEON 1029 Support for Infineon i2c bus TPM devices. Only one device 1030 per system is supported at this time. 1031 1032 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1033 Define the burst count bytes upper limit 1034 1035 CONFIG_TPM_ST33ZP24 1036 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1037 1038 CONFIG_TPM_ST33ZP24_I2C 1039 Support for STMicroelectronics ST33ZP24 I2C devices. 1040 Requires TPM_ST33ZP24 and I2C. 1041 1042 CONFIG_TPM_ST33ZP24_SPI 1043 Support for STMicroelectronics ST33ZP24 SPI devices. 1044 Requires TPM_ST33ZP24 and SPI. 1045 1046 CONFIG_TPM_ATMEL_TWI 1047 Support for Atmel TWI TPM device. Requires I2C support. 1048 1049 CONFIG_TPM_TIS_LPC 1050 Support for generic parallel port TPM devices. Only one device 1051 per system is supported at this time. 1052 1053 CONFIG_TPM_TIS_BASE_ADDRESS 1054 Base address where the generic TPM device is mapped 1055 to. Contemporary x86 systems usually map it at 1056 0xfed40000. 1057 1058 CONFIG_TPM 1059 Define this to enable the TPM support library which provides 1060 functional interfaces to some TPM commands. 1061 Requires support for a TPM device. 1062 1063 CONFIG_TPM_AUTH_SESSIONS 1064 Define this to enable authorized functions in the TPM library. 1065 Requires CONFIG_TPM and CONFIG_SHA1. 1066 1067- USB Support: 1068 At the moment only the UHCI host controller is 1069 supported (PIP405, MIP405); define 1070 CONFIG_USB_UHCI to enable it. 1071 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1072 and define CONFIG_USB_STORAGE to enable the USB 1073 storage devices. 1074 Note: 1075 Supported are USB Keyboards and USB Floppy drives 1076 (TEAC FD-05PUB). 1077 1078 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1079 txfilltuning field in the EHCI controller on reset. 1080 1081 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1082 HW module registers. 1083 1084- USB Device: 1085 Define the below if you wish to use the USB console. 1086 Once firmware is rebuilt from a serial console issue the 1087 command "setenv stdin usbtty; setenv stdout usbtty" and 1088 attach your USB cable. The Unix command "dmesg" should print 1089 it has found a new device. The environment variable usbtty 1090 can be set to gserial or cdc_acm to enable your device to 1091 appear to a USB host as a Linux gserial device or a 1092 Common Device Class Abstract Control Model serial device. 1093 If you select usbtty = gserial you should be able to enumerate 1094 a Linux host by 1095 # modprobe usbserial vendor=0xVendorID product=0xProductID 1096 else if using cdc_acm, simply setting the environment 1097 variable usbtty to be cdc_acm should suffice. The following 1098 might be defined in YourBoardName.h 1099 1100 CONFIG_USB_DEVICE 1101 Define this to build a UDC device 1102 1103 CONFIG_USB_TTY 1104 Define this to have a tty type of device available to 1105 talk to the UDC device 1106 1107 CONFIG_USBD_HS 1108 Define this to enable the high speed support for usb 1109 device and usbtty. If this feature is enabled, a routine 1110 int is_usbd_high_speed(void) 1111 also needs to be defined by the driver to dynamically poll 1112 whether the enumeration has succeded at high speed or full 1113 speed. 1114 1115 CONFIG_SYS_CONSOLE_IS_IN_ENV 1116 Define this if you want stdin, stdout &/or stderr to 1117 be set to usbtty. 1118 1119 If you have a USB-IF assigned VendorID then you may wish to 1120 define your own vendor specific values either in BoardName.h 1121 or directly in usbd_vendor_info.h. If you don't define 1122 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1123 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1124 should pretend to be a Linux device to it's target host. 1125 1126 CONFIG_USBD_MANUFACTURER 1127 Define this string as the name of your company for 1128 - CONFIG_USBD_MANUFACTURER "my company" 1129 1130 CONFIG_USBD_PRODUCT_NAME 1131 Define this string as the name of your product 1132 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1133 1134 CONFIG_USBD_VENDORID 1135 Define this as your assigned Vendor ID from the USB 1136 Implementors Forum. This *must* be a genuine Vendor ID 1137 to avoid polluting the USB namespace. 1138 - CONFIG_USBD_VENDORID 0xFFFF 1139 1140 CONFIG_USBD_PRODUCTID 1141 Define this as the unique Product ID 1142 for your device 1143 - CONFIG_USBD_PRODUCTID 0xFFFF 1144 1145- ULPI Layer Support: 1146 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1147 the generic ULPI layer. The generic layer accesses the ULPI PHY 1148 via the platform viewport, so you need both the genric layer and 1149 the viewport enabled. Currently only Chipidea/ARC based 1150 viewport is supported. 1151 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1152 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1153 If your ULPI phy needs a different reference clock than the 1154 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1155 the appropriate value in Hz. 1156 1157- MMC Support: 1158 The MMC controller on the Intel PXA is supported. To 1159 enable this define CONFIG_MMC. The MMC can be 1160 accessed from the boot prompt by mapping the device 1161 to physical memory similar to flash. Command line is 1162 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1163 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1164 1165 CONFIG_SH_MMCIF 1166 Support for Renesas on-chip MMCIF controller 1167 1168 CONFIG_SH_MMCIF_ADDR 1169 Define the base address of MMCIF registers 1170 1171 CONFIG_SH_MMCIF_CLK 1172 Define the clock frequency for MMCIF 1173 1174 CONFIG_SUPPORT_EMMC_BOOT 1175 Enable some additional features of the eMMC boot partitions. 1176 1177 CONFIG_SUPPORT_EMMC_RPMB 1178 Enable the commands for reading, writing and programming the 1179 key for the Replay Protection Memory Block partition in eMMC. 1180 1181- USB Device Firmware Update (DFU) class support: 1182 CONFIG_DFU_OVER_USB 1183 This enables the USB portion of the DFU USB class 1184 1185 CONFIG_DFU_MMC 1186 This enables support for exposing (e)MMC devices via DFU. 1187 1188 CONFIG_DFU_NAND 1189 This enables support for exposing NAND devices via DFU. 1190 1191 CONFIG_DFU_RAM 1192 This enables support for exposing RAM via DFU. 1193 Note: DFU spec refer to non-volatile memory usage, but 1194 allow usages beyond the scope of spec - here RAM usage, 1195 one that would help mostly the developer. 1196 1197 CONFIG_SYS_DFU_DATA_BUF_SIZE 1198 Dfu transfer uses a buffer before writing data to the 1199 raw storage device. Make the size (in bytes) of this buffer 1200 configurable. The size of this buffer is also configurable 1201 through the "dfu_bufsiz" environment variable. 1202 1203 CONFIG_SYS_DFU_MAX_FILE_SIZE 1204 When updating files rather than the raw storage device, 1205 we use a static buffer to copy the file into and then write 1206 the buffer once we've been given the whole file. Define 1207 this to the maximum filesize (in bytes) for the buffer. 1208 Default is 4 MiB if undefined. 1209 1210 DFU_DEFAULT_POLL_TIMEOUT 1211 Poll timeout [ms], is the timeout a device can send to the 1212 host. The host must wait for this timeout before sending 1213 a subsequent DFU_GET_STATUS request to the device. 1214 1215 DFU_MANIFEST_POLL_TIMEOUT 1216 Poll timeout [ms], which the device sends to the host when 1217 entering dfuMANIFEST state. Host waits this timeout, before 1218 sending again an USB request to the device. 1219 1220- Journaling Flash filesystem support: 1221 CONFIG_JFFS2_NAND 1222 Define these for a default partition on a NAND device 1223 1224 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1225 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1226 Define these for a default partition on a NOR device 1227 1228- Keyboard Support: 1229 See Kconfig help for available keyboard drivers. 1230 1231 CONFIG_KEYBOARD 1232 1233 Define this to enable a custom keyboard support. 1234 This simply calls drv_keyboard_init() which must be 1235 defined in your board-specific files. This option is deprecated 1236 and is only used by novena. For new boards, use driver model 1237 instead. 1238 1239- Video support: 1240 CONFIG_FSL_DIU_FB 1241 Enable the Freescale DIU video driver. Reference boards for 1242 SOCs that have a DIU should define this macro to enable DIU 1243 support, and should also define these other macros: 1244 1245 CONFIG_SYS_DIU_ADDR 1246 CONFIG_VIDEO 1247 CONFIG_CFB_CONSOLE 1248 CONFIG_VIDEO_SW_CURSOR 1249 CONFIG_VGA_AS_SINGLE_DEVICE 1250 CONFIG_VIDEO_LOGO 1251 CONFIG_VIDEO_BMP_LOGO 1252 1253 The DIU driver will look for the 'video-mode' environment 1254 variable, and if defined, enable the DIU as a console during 1255 boot. See the documentation file doc/README.video for a 1256 description of this variable. 1257 1258- LCD Support: CONFIG_LCD 1259 1260 Define this to enable LCD support (for output to LCD 1261 display); also select one of the supported displays 1262 by defining one of these: 1263 1264 CONFIG_ATMEL_LCD: 1265 1266 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1267 1268 CONFIG_NEC_NL6448AC33: 1269 1270 NEC NL6448AC33-18. Active, color, single scan. 1271 1272 CONFIG_NEC_NL6448BC20 1273 1274 NEC NL6448BC20-08. 6.5", 640x480. 1275 Active, color, single scan. 1276 1277 CONFIG_NEC_NL6448BC33_54 1278 1279 NEC NL6448BC33-54. 10.4", 640x480. 1280 Active, color, single scan. 1281 1282 CONFIG_SHARP_16x9 1283 1284 Sharp 320x240. Active, color, single scan. 1285 It isn't 16x9, and I am not sure what it is. 1286 1287 CONFIG_SHARP_LQ64D341 1288 1289 Sharp LQ64D341 display, 640x480. 1290 Active, color, single scan. 1291 1292 CONFIG_HLD1045 1293 1294 HLD1045 display, 640x480. 1295 Active, color, single scan. 1296 1297 CONFIG_OPTREX_BW 1298 1299 Optrex CBL50840-2 NF-FW 99 22 M5 1300 or 1301 Hitachi LMG6912RPFC-00T 1302 or 1303 Hitachi SP14Q002 1304 1305 320x240. Black & white. 1306 1307 CONFIG_LCD_ALIGNMENT 1308 1309 Normally the LCD is page-aligned (typically 4KB). If this is 1310 defined then the LCD will be aligned to this value instead. 1311 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1312 here, since it is cheaper to change data cache settings on 1313 a per-section basis. 1314 1315 1316 CONFIG_LCD_ROTATION 1317 1318 Sometimes, for example if the display is mounted in portrait 1319 mode or even if it's mounted landscape but rotated by 180degree, 1320 we need to rotate our content of the display relative to the 1321 framebuffer, so that user can read the messages which are 1322 printed out. 1323 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1324 initialized with a given rotation from "vl_rot" out of 1325 "vidinfo_t" which is provided by the board specific code. 1326 The value for vl_rot is coded as following (matching to 1327 fbcon=rotate:<n> linux-kernel commandline): 1328 0 = no rotation respectively 0 degree 1329 1 = 90 degree rotation 1330 2 = 180 degree rotation 1331 3 = 270 degree rotation 1332 1333 If CONFIG_LCD_ROTATION is not defined, the console will be 1334 initialized with 0degree rotation. 1335 1336 CONFIG_LCD_BMP_RLE8 1337 1338 Support drawing of RLE8-compressed bitmaps on the LCD. 1339 1340 CONFIG_I2C_EDID 1341 1342 Enables an 'i2c edid' command which can read EDID 1343 information over I2C from an attached LCD display. 1344 1345- Splash Screen Support: CONFIG_SPLASH_SCREEN 1346 1347 If this option is set, the environment is checked for 1348 a variable "splashimage". If found, the usual display 1349 of logo, copyright and system information on the LCD 1350 is suppressed and the BMP image at the address 1351 specified in "splashimage" is loaded instead. The 1352 console is redirected to the "nulldev", too. This 1353 allows for a "silent" boot where a splash screen is 1354 loaded very quickly after power-on. 1355 1356 CONFIG_SPLASHIMAGE_GUARD 1357 1358 If this option is set, then U-Boot will prevent the environment 1359 variable "splashimage" from being set to a problematic address 1360 (see doc/README.displaying-bmps). 1361 This option is useful for targets where, due to alignment 1362 restrictions, an improperly aligned BMP image will cause a data 1363 abort. If you think you will not have problems with unaligned 1364 accesses (for example because your toolchain prevents them) 1365 there is no need to set this option. 1366 1367 CONFIG_SPLASH_SCREEN_ALIGN 1368 1369 If this option is set the splash image can be freely positioned 1370 on the screen. Environment variable "splashpos" specifies the 1371 position as "x,y". If a positive number is given it is used as 1372 number of pixel from left/top. If a negative number is given it 1373 is used as number of pixel from right/bottom. You can also 1374 specify 'm' for centering the image. 1375 1376 Example: 1377 setenv splashpos m,m 1378 => image at center of screen 1379 1380 setenv splashpos 30,20 1381 => image at x = 30 and y = 20 1382 1383 setenv splashpos -10,m 1384 => vertically centered image 1385 at x = dspWidth - bmpWidth - 9 1386 1387- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1388 1389 If this option is set, additionally to standard BMP 1390 images, gzipped BMP images can be displayed via the 1391 splashscreen support or the bmp command. 1392 1393- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1394 1395 If this option is set, 8-bit RLE compressed BMP images 1396 can be displayed via the splashscreen support or the 1397 bmp command. 1398 1399- Compression support: 1400 CONFIG_GZIP 1401 1402 Enabled by default to support gzip compressed images. 1403 1404 CONFIG_BZIP2 1405 1406 If this option is set, support for bzip2 compressed 1407 images is included. If not, only uncompressed and gzip 1408 compressed images are supported. 1409 1410 NOTE: the bzip2 algorithm requires a lot of RAM, so 1411 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1412 be at least 4MB. 1413 1414- MII/PHY support: 1415 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1416 1417 The clock frequency of the MII bus 1418 1419 CONFIG_PHY_RESET_DELAY 1420 1421 Some PHY like Intel LXT971A need extra delay after 1422 reset before any MII register access is possible. 1423 For such PHY, set this option to the usec delay 1424 required. (minimum 300usec for LXT971A) 1425 1426 CONFIG_PHY_CMD_DELAY (ppc4xx) 1427 1428 Some PHY like Intel LXT971A need extra delay after 1429 command issued before MII status register can be read 1430 1431- IP address: 1432 CONFIG_IPADDR 1433 1434 Define a default value for the IP address to use for 1435 the default Ethernet interface, in case this is not 1436 determined through e.g. bootp. 1437 (Environment variable "ipaddr") 1438 1439- Server IP address: 1440 CONFIG_SERVERIP 1441 1442 Defines a default value for the IP address of a TFTP 1443 server to contact when using the "tftboot" command. 1444 (Environment variable "serverip") 1445 1446 CONFIG_KEEP_SERVERADDR 1447 1448 Keeps the server's MAC address, in the env 'serveraddr' 1449 for passing to bootargs (like Linux's netconsole option) 1450 1451- Gateway IP address: 1452 CONFIG_GATEWAYIP 1453 1454 Defines a default value for the IP address of the 1455 default router where packets to other networks are 1456 sent to. 1457 (Environment variable "gatewayip") 1458 1459- Subnet mask: 1460 CONFIG_NETMASK 1461 1462 Defines a default value for the subnet mask (or 1463 routing prefix) which is used to determine if an IP 1464 address belongs to the local subnet or needs to be 1465 forwarded through a router. 1466 (Environment variable "netmask") 1467 1468- Multicast TFTP Mode: 1469 CONFIG_MCAST_TFTP 1470 1471 Defines whether you want to support multicast TFTP as per 1472 rfc-2090; for example to work with atftp. Lets lots of targets 1473 tftp down the same boot image concurrently. Note: the Ethernet 1474 driver in use must provide a function: mcast() to join/leave a 1475 multicast group. 1476 1477- BOOTP Recovery Mode: 1478 CONFIG_BOOTP_RANDOM_DELAY 1479 1480 If you have many targets in a network that try to 1481 boot using BOOTP, you may want to avoid that all 1482 systems send out BOOTP requests at precisely the same 1483 moment (which would happen for instance at recovery 1484 from a power failure, when all systems will try to 1485 boot, thus flooding the BOOTP server. Defining 1486 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1487 inserted before sending out BOOTP requests. The 1488 following delays are inserted then: 1489 1490 1st BOOTP request: delay 0 ... 1 sec 1491 2nd BOOTP request: delay 0 ... 2 sec 1492 3rd BOOTP request: delay 0 ... 4 sec 1493 4th and following 1494 BOOTP requests: delay 0 ... 8 sec 1495 1496 CONFIG_BOOTP_ID_CACHE_SIZE 1497 1498 BOOTP packets are uniquely identified using a 32-bit ID. The 1499 server will copy the ID from client requests to responses and 1500 U-Boot will use this to determine if it is the destination of 1501 an incoming response. Some servers will check that addresses 1502 aren't in use before handing them out (usually using an ARP 1503 ping) and therefore take up to a few hundred milliseconds to 1504 respond. Network congestion may also influence the time it 1505 takes for a response to make it back to the client. If that 1506 time is too long, U-Boot will retransmit requests. In order 1507 to allow earlier responses to still be accepted after these 1508 retransmissions, U-Boot's BOOTP client keeps a small cache of 1509 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1510 cache. The default is to keep IDs for up to four outstanding 1511 requests. Increasing this will allow U-Boot to accept offers 1512 from a BOOTP client in networks with unusually high latency. 1513 1514- DHCP Advanced Options: 1515 You can fine tune the DHCP functionality by defining 1516 CONFIG_BOOTP_* symbols: 1517 1518 CONFIG_BOOTP_NISDOMAIN 1519 CONFIG_BOOTP_BOOTFILESIZE 1520 CONFIG_BOOTP_SEND_HOSTNAME 1521 CONFIG_BOOTP_NTPSERVER 1522 CONFIG_BOOTP_TIMEOFFSET 1523 CONFIG_BOOTP_VENDOREX 1524 CONFIG_BOOTP_MAY_FAIL 1525 1526 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1527 environment variable, not the BOOTP server. 1528 1529 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1530 after the configured retry count, the call will fail 1531 instead of starting over. This can be used to fail over 1532 to Link-local IP address configuration if the DHCP server 1533 is not available. 1534 1535 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1536 to do a dynamic update of a DNS server. To do this, they 1537 need the hostname of the DHCP requester. 1538 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1539 of the "hostname" environment variable is passed as 1540 option 12 to the DHCP server. 1541 1542 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1543 1544 A 32bit value in microseconds for a delay between 1545 receiving a "DHCP Offer" and sending the "DHCP Request". 1546 This fixes a problem with certain DHCP servers that don't 1547 respond 100% of the time to a "DHCP request". E.g. On an 1548 AT91RM9200 processor running at 180MHz, this delay needed 1549 to be *at least* 15,000 usec before a Windows Server 2003 1550 DHCP server would reply 100% of the time. I recommend at 1551 least 50,000 usec to be safe. The alternative is to hope 1552 that one of the retries will be successful but note that 1553 the DHCP timeout and retry process takes a longer than 1554 this delay. 1555 1556 - Link-local IP address negotiation: 1557 Negotiate with other link-local clients on the local network 1558 for an address that doesn't require explicit configuration. 1559 This is especially useful if a DHCP server cannot be guaranteed 1560 to exist in all environments that the device must operate. 1561 1562 See doc/README.link-local for more information. 1563 1564 - MAC address from environment variables 1565 1566 FDT_SEQ_MACADDR_FROM_ENV 1567 1568 Fix-up device tree with MAC addresses fetched sequentially from 1569 environment variables. This config work on assumption that 1570 non-usable ethernet node of device-tree are either not present 1571 or their status has been marked as "disabled". 1572 1573 - CDP Options: 1574 CONFIG_CDP_DEVICE_ID 1575 1576 The device id used in CDP trigger frames. 1577 1578 CONFIG_CDP_DEVICE_ID_PREFIX 1579 1580 A two character string which is prefixed to the MAC address 1581 of the device. 1582 1583 CONFIG_CDP_PORT_ID 1584 1585 A printf format string which contains the ascii name of 1586 the port. Normally is set to "eth%d" which sets 1587 eth0 for the first Ethernet, eth1 for the second etc. 1588 1589 CONFIG_CDP_CAPABILITIES 1590 1591 A 32bit integer which indicates the device capabilities; 1592 0x00000010 for a normal host which does not forwards. 1593 1594 CONFIG_CDP_VERSION 1595 1596 An ascii string containing the version of the software. 1597 1598 CONFIG_CDP_PLATFORM 1599 1600 An ascii string containing the name of the platform. 1601 1602 CONFIG_CDP_TRIGGER 1603 1604 A 32bit integer sent on the trigger. 1605 1606 CONFIG_CDP_POWER_CONSUMPTION 1607 1608 A 16bit integer containing the power consumption of the 1609 device in .1 of milliwatts. 1610 1611 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1612 1613 A byte containing the id of the VLAN. 1614 1615- Status LED: CONFIG_LED_STATUS 1616 1617 Several configurations allow to display the current 1618 status using a LED. For instance, the LED will blink 1619 fast while running U-Boot code, stop blinking as 1620 soon as a reply to a BOOTP request was received, and 1621 start blinking slow once the Linux kernel is running 1622 (supported by a status LED driver in the Linux 1623 kernel). Defining CONFIG_LED_STATUS enables this 1624 feature in U-Boot. 1625 1626 Additional options: 1627 1628 CONFIG_LED_STATUS_GPIO 1629 The status LED can be connected to a GPIO pin. 1630 In such cases, the gpio_led driver can be used as a 1631 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1632 to include the gpio_led driver in the U-Boot binary. 1633 1634 CONFIG_GPIO_LED_INVERTED_TABLE 1635 Some GPIO connected LEDs may have inverted polarity in which 1636 case the GPIO high value corresponds to LED off state and 1637 GPIO low value corresponds to LED on state. 1638 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1639 with a list of GPIO LEDs that have inverted polarity. 1640 1641- I2C Support: CONFIG_SYS_I2C 1642 1643 This enable the NEW i2c subsystem, and will allow you to use 1644 i2c commands at the u-boot command line (as long as you set 1645 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1646 based realtime clock chips or other i2c devices. See 1647 common/cmd_i2c.c for a description of the command line 1648 interface. 1649 1650 ported i2c driver to the new framework: 1651 - drivers/i2c/soft_i2c.c: 1652 - activate first bus with CONFIG_SYS_I2C_SOFT define 1653 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1654 for defining speed and slave address 1655 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1656 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1657 for defining speed and slave address 1658 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1659 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1660 for defining speed and slave address 1661 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1662 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1663 for defining speed and slave address 1664 1665 - drivers/i2c/fsl_i2c.c: 1666 - activate i2c driver with CONFIG_SYS_I2C_FSL 1667 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1668 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1669 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1670 bus. 1671 - If your board supports a second fsl i2c bus, define 1672 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1673 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1674 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1675 second bus. 1676 1677 - drivers/i2c/tegra_i2c.c: 1678 - activate this driver with CONFIG_SYS_I2C_TEGRA 1679 - This driver adds 4 i2c buses with a fix speed from 1680 100000 and the slave addr 0! 1681 1682 - drivers/i2c/ppc4xx_i2c.c 1683 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1684 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1685 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1686 1687 - drivers/i2c/i2c_mxc.c 1688 - activate this driver with CONFIG_SYS_I2C_MXC 1689 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1690 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1691 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1692 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1693 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1694 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1695 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1696 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1697 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1698 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1699 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1700 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1701 If those defines are not set, default value is 100000 1702 for speed, and 0 for slave. 1703 1704 - drivers/i2c/rcar_i2c.c: 1705 - activate this driver with CONFIG_SYS_I2C_RCAR 1706 - This driver adds 4 i2c buses 1707 1708 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1709 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1710 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1711 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1712 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1713 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1714 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1715 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1716 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1717 1718 - drivers/i2c/sh_i2c.c: 1719 - activate this driver with CONFIG_SYS_I2C_SH 1720 - This driver adds from 2 to 5 i2c buses 1721 1722 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1723 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1724 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1725 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1726 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1727 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1728 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1729 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1730 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1731 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1732 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1733 1734 - drivers/i2c/omap24xx_i2c.c 1735 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1736 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1737 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1738 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1739 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1740 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1741 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1742 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1743 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1744 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1745 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1746 1747 - drivers/i2c/zynq_i2c.c 1748 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1749 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1750 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1751 1752 - drivers/i2c/s3c24x0_i2c.c: 1753 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1754 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1755 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1756 with a fix speed from 100000 and the slave addr 0! 1757 1758 - drivers/i2c/ihs_i2c.c 1759 - activate this driver with CONFIG_SYS_I2C_IHS 1760 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1761 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1762 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1763 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1764 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1765 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1766 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1767 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1768 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1769 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1770 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1771 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1772 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1773 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1774 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1775 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1776 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1777 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1778 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1779 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1780 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1781 1782 additional defines: 1783 1784 CONFIG_SYS_NUM_I2C_BUSES 1785 Hold the number of i2c buses you want to use. 1786 1787 CONFIG_SYS_I2C_DIRECT_BUS 1788 define this, if you don't use i2c muxes on your hardware. 1789 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1790 omit this define. 1791 1792 CONFIG_SYS_I2C_MAX_HOPS 1793 define how many muxes are maximal consecutively connected 1794 on one i2c bus. If you not use i2c muxes, omit this 1795 define. 1796 1797 CONFIG_SYS_I2C_BUSES 1798 hold a list of buses you want to use, only used if 1799 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1800 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1801 CONFIG_SYS_NUM_I2C_BUSES = 9: 1802 1803 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1804 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1805 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1806 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1807 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1808 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1809 {1, {I2C_NULL_HOP}}, \ 1810 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1811 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1812 } 1813 1814 which defines 1815 bus 0 on adapter 0 without a mux 1816 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1817 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1818 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1819 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1820 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1821 bus 6 on adapter 1 without a mux 1822 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1823 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1824 1825 If you do not have i2c muxes on your board, omit this define. 1826 1827- Legacy I2C Support: 1828 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1829 then the following macros need to be defined (examples are 1830 from include/configs/lwmon.h): 1831 1832 I2C_INIT 1833 1834 (Optional). Any commands necessary to enable the I2C 1835 controller or configure ports. 1836 1837 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1838 1839 I2C_ACTIVE 1840 1841 The code necessary to make the I2C data line active 1842 (driven). If the data line is open collector, this 1843 define can be null. 1844 1845 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1846 1847 I2C_TRISTATE 1848 1849 The code necessary to make the I2C data line tri-stated 1850 (inactive). If the data line is open collector, this 1851 define can be null. 1852 1853 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1854 1855 I2C_READ 1856 1857 Code that returns true if the I2C data line is high, 1858 false if it is low. 1859 1860 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1861 1862 I2C_SDA(bit) 1863 1864 If <bit> is true, sets the I2C data line high. If it 1865 is false, it clears it (low). 1866 1867 eg: #define I2C_SDA(bit) \ 1868 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1869 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1870 1871 I2C_SCL(bit) 1872 1873 If <bit> is true, sets the I2C clock line high. If it 1874 is false, it clears it (low). 1875 1876 eg: #define I2C_SCL(bit) \ 1877 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1878 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1879 1880 I2C_DELAY 1881 1882 This delay is invoked four times per clock cycle so this 1883 controls the rate of data transfer. The data rate thus 1884 is 1 / (I2C_DELAY * 4). Often defined to be something 1885 like: 1886 1887 #define I2C_DELAY udelay(2) 1888 1889 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1890 1891 If your arch supports the generic GPIO framework (asm/gpio.h), 1892 then you may alternatively define the two GPIOs that are to be 1893 used as SCL / SDA. Any of the previous I2C_xxx macros will 1894 have GPIO-based defaults assigned to them as appropriate. 1895 1896 You should define these to the GPIO value as given directly to 1897 the generic GPIO functions. 1898 1899 CONFIG_SYS_I2C_INIT_BOARD 1900 1901 When a board is reset during an i2c bus transfer 1902 chips might think that the current transfer is still 1903 in progress. On some boards it is possible to access 1904 the i2c SCLK line directly, either by using the 1905 processor pin as a GPIO or by having a second pin 1906 connected to the bus. If this option is defined a 1907 custom i2c_init_board() routine in boards/xxx/board.c 1908 is run early in the boot sequence. 1909 1910 CONFIG_I2C_MULTI_BUS 1911 1912 This option allows the use of multiple I2C buses, each of which 1913 must have a controller. At any point in time, only one bus is 1914 active. To switch to a different bus, use the 'i2c dev' command. 1915 Note that bus numbering is zero-based. 1916 1917 CONFIG_SYS_I2C_NOPROBES 1918 1919 This option specifies a list of I2C devices that will be skipped 1920 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1921 is set, specify a list of bus-device pairs. Otherwise, specify 1922 a 1D array of device addresses 1923 1924 e.g. 1925 #undef CONFIG_I2C_MULTI_BUS 1926 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1927 1928 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1929 1930 #define CONFIG_I2C_MULTI_BUS 1931 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1932 1933 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1934 1935 CONFIG_SYS_SPD_BUS_NUM 1936 1937 If defined, then this indicates the I2C bus number for DDR SPD. 1938 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1939 1940 CONFIG_SYS_RTC_BUS_NUM 1941 1942 If defined, then this indicates the I2C bus number for the RTC. 1943 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1944 1945 CONFIG_SOFT_I2C_READ_REPEATED_START 1946 1947 defining this will force the i2c_read() function in 1948 the soft_i2c driver to perform an I2C repeated start 1949 between writing the address pointer and reading the 1950 data. If this define is omitted the default behaviour 1951 of doing a stop-start sequence will be used. Most I2C 1952 devices can use either method, but some require one or 1953 the other. 1954 1955- SPI Support: CONFIG_SPI 1956 1957 Enables SPI driver (so far only tested with 1958 SPI EEPROM, also an instance works with Crystal A/D and 1959 D/As on the SACSng board) 1960 1961 CONFIG_SOFT_SPI 1962 1963 Enables a software (bit-bang) SPI driver rather than 1964 using hardware support. This is a general purpose 1965 driver that only requires three general I/O port pins 1966 (two outputs, one input) to function. If this is 1967 defined, the board configuration must define several 1968 SPI configuration items (port pins to use, etc). For 1969 an example, see include/configs/sacsng.h. 1970 1971 CONFIG_HARD_SPI 1972 1973 Enables a hardware SPI driver for general-purpose reads 1974 and writes. As with CONFIG_SOFT_SPI, the board configuration 1975 must define a list of chip-select function pointers. 1976 Currently supported on some MPC8xxx processors. For an 1977 example, see include/configs/mpc8349emds.h. 1978 1979 CONFIG_SYS_SPI_MXC_WAIT 1980 Timeout for waiting until spi transfer completed. 1981 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1982 1983- FPGA Support: CONFIG_FPGA 1984 1985 Enables FPGA subsystem. 1986 1987 CONFIG_FPGA_<vendor> 1988 1989 Enables support for specific chip vendors. 1990 (ALTERA, XILINX) 1991 1992 CONFIG_FPGA_<family> 1993 1994 Enables support for FPGA family. 1995 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 1996 1997 CONFIG_FPGA_COUNT 1998 1999 Specify the number of FPGA devices to support. 2000 2001 CONFIG_SYS_FPGA_PROG_FEEDBACK 2002 2003 Enable printing of hash marks during FPGA configuration. 2004 2005 CONFIG_SYS_FPGA_CHECK_BUSY 2006 2007 Enable checks on FPGA configuration interface busy 2008 status by the configuration function. This option 2009 will require a board or device specific function to 2010 be written. 2011 2012 CONFIG_FPGA_DELAY 2013 2014 If defined, a function that provides delays in the FPGA 2015 configuration driver. 2016 2017 CONFIG_SYS_FPGA_CHECK_CTRLC 2018 Allow Control-C to interrupt FPGA configuration 2019 2020 CONFIG_SYS_FPGA_CHECK_ERROR 2021 2022 Check for configuration errors during FPGA bitfile 2023 loading. For example, abort during Virtex II 2024 configuration if the INIT_B line goes low (which 2025 indicated a CRC error). 2026 2027 CONFIG_SYS_FPGA_WAIT_INIT 2028 2029 Maximum time to wait for the INIT_B line to de-assert 2030 after PROB_B has been de-asserted during a Virtex II 2031 FPGA configuration sequence. The default time is 500 2032 ms. 2033 2034 CONFIG_SYS_FPGA_WAIT_BUSY 2035 2036 Maximum time to wait for BUSY to de-assert during 2037 Virtex II FPGA configuration. The default is 5 ms. 2038 2039 CONFIG_SYS_FPGA_WAIT_CONFIG 2040 2041 Time to wait after FPGA configuration. The default is 2042 200 ms. 2043 2044- Configuration Management: 2045 CONFIG_BUILD_TARGET 2046 2047 Some SoCs need special image types (e.g. U-Boot binary 2048 with a special header) as build targets. By defining 2049 CONFIG_BUILD_TARGET in the SoC / board header, this 2050 special image will be automatically built upon calling 2051 make / buildman. 2052 2053 CONFIG_IDENT_STRING 2054 2055 If defined, this string will be added to the U-Boot 2056 version information (U_BOOT_VERSION) 2057 2058- Vendor Parameter Protection: 2059 2060 U-Boot considers the values of the environment 2061 variables "serial#" (Board Serial Number) and 2062 "ethaddr" (Ethernet Address) to be parameters that 2063 are set once by the board vendor / manufacturer, and 2064 protects these variables from casual modification by 2065 the user. Once set, these variables are read-only, 2066 and write or delete attempts are rejected. You can 2067 change this behaviour: 2068 2069 If CONFIG_ENV_OVERWRITE is #defined in your config 2070 file, the write protection for vendor parameters is 2071 completely disabled. Anybody can change or delete 2072 these parameters. 2073 2074 Alternatively, if you define _both_ an ethaddr in the 2075 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2076 Ethernet address is installed in the environment, 2077 which can be changed exactly ONCE by the user. [The 2078 serial# is unaffected by this, i. e. it remains 2079 read-only.] 2080 2081 The same can be accomplished in a more flexible way 2082 for any variable by configuring the type of access 2083 to allow for those variables in the ".flags" variable 2084 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2085 2086- Protected RAM: 2087 CONFIG_PRAM 2088 2089 Define this variable to enable the reservation of 2090 "protected RAM", i. e. RAM which is not overwritten 2091 by U-Boot. Define CONFIG_PRAM to hold the number of 2092 kB you want to reserve for pRAM. You can overwrite 2093 this default value by defining an environment 2094 variable "pram" to the number of kB you want to 2095 reserve. Note that the board info structure will 2096 still show the full amount of RAM. If pRAM is 2097 reserved, a new environment variable "mem" will 2098 automatically be defined to hold the amount of 2099 remaining RAM in a form that can be passed as boot 2100 argument to Linux, for instance like that: 2101 2102 setenv bootargs ... mem=\${mem} 2103 saveenv 2104 2105 This way you can tell Linux not to use this memory, 2106 either, which results in a memory region that will 2107 not be affected by reboots. 2108 2109 *WARNING* If your board configuration uses automatic 2110 detection of the RAM size, you must make sure that 2111 this memory test is non-destructive. So far, the 2112 following board configurations are known to be 2113 "pRAM-clean": 2114 2115 IVMS8, IVML24, SPD8xx, 2116 HERMES, IP860, RPXlite, LWMON, 2117 FLAGADM 2118 2119- Access to physical memory region (> 4GB) 2120 Some basic support is provided for operations on memory not 2121 normally accessible to U-Boot - e.g. some architectures 2122 support access to more than 4GB of memory on 32-bit 2123 machines using physical address extension or similar. 2124 Define CONFIG_PHYSMEM to access this basic support, which 2125 currently only supports clearing the memory. 2126 2127- Error Recovery: 2128 CONFIG_NET_RETRY_COUNT 2129 2130 This variable defines the number of retries for 2131 network operations like ARP, RARP, TFTP, or BOOTP 2132 before giving up the operation. If not defined, a 2133 default value of 5 is used. 2134 2135 CONFIG_ARP_TIMEOUT 2136 2137 Timeout waiting for an ARP reply in milliseconds. 2138 2139 CONFIG_NFS_TIMEOUT 2140 2141 Timeout in milliseconds used in NFS protocol. 2142 If you encounter "ERROR: Cannot umount" in nfs command, 2143 try longer timeout such as 2144 #define CONFIG_NFS_TIMEOUT 10000UL 2145 2146- Command Interpreter: 2147 CONFIG_SYS_PROMPT_HUSH_PS2 2148 2149 This defines the secondary prompt string, which is 2150 printed when the command interpreter needs more input 2151 to complete a command. Usually "> ". 2152 2153 Note: 2154 2155 In the current implementation, the local variables 2156 space and global environment variables space are 2157 separated. Local variables are those you define by 2158 simply typing `name=value'. To access a local 2159 variable later on, you have write `$name' or 2160 `${name}'; to execute the contents of a variable 2161 directly type `$name' at the command prompt. 2162 2163 Global environment variables are those you use 2164 setenv/printenv to work with. To run a command stored 2165 in such a variable, you need to use the run command, 2166 and you must not use the '$' sign to access them. 2167 2168 To store commands and special characters in a 2169 variable, please use double quotation marks 2170 surrounding the whole text of the variable, instead 2171 of the backslashes before semicolons and special 2172 symbols. 2173 2174- Command Line Editing and History: 2175 CONFIG_CMDLINE_PS_SUPPORT 2176 2177 Enable support for changing the command prompt string 2178 at run-time. Only static string is supported so far. 2179 The string is obtained from environment variables PS1 2180 and PS2. 2181 2182- Default Environment: 2183 CONFIG_EXTRA_ENV_SETTINGS 2184 2185 Define this to contain any number of null terminated 2186 strings (variable = value pairs) that will be part of 2187 the default environment compiled into the boot image. 2188 2189 For example, place something like this in your 2190 board's config file: 2191 2192 #define CONFIG_EXTRA_ENV_SETTINGS \ 2193 "myvar1=value1\0" \ 2194 "myvar2=value2\0" 2195 2196 Warning: This method is based on knowledge about the 2197 internal format how the environment is stored by the 2198 U-Boot code. This is NOT an official, exported 2199 interface! Although it is unlikely that this format 2200 will change soon, there is no guarantee either. 2201 You better know what you are doing here. 2202 2203 Note: overly (ab)use of the default environment is 2204 discouraged. Make sure to check other ways to preset 2205 the environment like the "source" command or the 2206 boot command first. 2207 2208 CONFIG_DELAY_ENVIRONMENT 2209 2210 Normally the environment is loaded when the board is 2211 initialised so that it is available to U-Boot. This inhibits 2212 that so that the environment is not available until 2213 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2214 this is instead controlled by the value of 2215 /config/load-environment. 2216 2217- Serial Flash support 2218 Usage requires an initial 'sf probe' to define the serial 2219 flash parameters, followed by read/write/erase/update 2220 commands. 2221 2222 The following defaults may be provided by the platform 2223 to handle the common case when only a single serial 2224 flash is present on the system. 2225 2226 CONFIG_SF_DEFAULT_BUS Bus identifier 2227 CONFIG_SF_DEFAULT_CS Chip-select 2228 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2229 CONFIG_SF_DEFAULT_SPEED in Hz 2230 2231 2232- TFTP Fixed UDP Port: 2233 CONFIG_TFTP_PORT 2234 2235 If this is defined, the environment variable tftpsrcp 2236 is used to supply the TFTP UDP source port value. 2237 If tftpsrcp isn't defined, the normal pseudo-random port 2238 number generator is used. 2239 2240 Also, the environment variable tftpdstp is used to supply 2241 the TFTP UDP destination port value. If tftpdstp isn't 2242 defined, the normal port 69 is used. 2243 2244 The purpose for tftpsrcp is to allow a TFTP server to 2245 blindly start the TFTP transfer using the pre-configured 2246 target IP address and UDP port. This has the effect of 2247 "punching through" the (Windows XP) firewall, allowing 2248 the remainder of the TFTP transfer to proceed normally. 2249 A better solution is to properly configure the firewall, 2250 but sometimes that is not allowed. 2251 2252- Show boot progress: 2253 CONFIG_SHOW_BOOT_PROGRESS 2254 2255 Defining this option allows to add some board- 2256 specific code (calling a user-provided function 2257 "show_boot_progress(int)") that enables you to show 2258 the system's boot progress on some display (for 2259 example, some LED's) on your board. At the moment, 2260 the following checkpoints are implemented: 2261 2262 2263Legacy uImage format: 2264 2265 Arg Where When 2266 1 common/cmd_bootm.c before attempting to boot an image 2267 -1 common/cmd_bootm.c Image header has bad magic number 2268 2 common/cmd_bootm.c Image header has correct magic number 2269 -2 common/cmd_bootm.c Image header has bad checksum 2270 3 common/cmd_bootm.c Image header has correct checksum 2271 -3 common/cmd_bootm.c Image data has bad checksum 2272 4 common/cmd_bootm.c Image data has correct checksum 2273 -4 common/cmd_bootm.c Image is for unsupported architecture 2274 5 common/cmd_bootm.c Architecture check OK 2275 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2276 6 common/cmd_bootm.c Image Type check OK 2277 -6 common/cmd_bootm.c gunzip uncompression error 2278 -7 common/cmd_bootm.c Unimplemented compression type 2279 7 common/cmd_bootm.c Uncompression OK 2280 8 common/cmd_bootm.c No uncompress/copy overwrite error 2281 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2282 2283 9 common/image.c Start initial ramdisk verification 2284 -10 common/image.c Ramdisk header has bad magic number 2285 -11 common/image.c Ramdisk header has bad checksum 2286 10 common/image.c Ramdisk header is OK 2287 -12 common/image.c Ramdisk data has bad checksum 2288 11 common/image.c Ramdisk data has correct checksum 2289 12 common/image.c Ramdisk verification complete, start loading 2290 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2291 13 common/image.c Start multifile image verification 2292 14 common/image.c No initial ramdisk, no multifile, continue. 2293 2294 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2295 2296 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2297 -31 post/post.c POST test failed, detected by post_output_backlog() 2298 -32 post/post.c POST test failed, detected by post_run_single() 2299 2300 34 common/cmd_doc.c before loading a Image from a DOC device 2301 -35 common/cmd_doc.c Bad usage of "doc" command 2302 35 common/cmd_doc.c correct usage of "doc" command 2303 -36 common/cmd_doc.c No boot device 2304 36 common/cmd_doc.c correct boot device 2305 -37 common/cmd_doc.c Unknown Chip ID on boot device 2306 37 common/cmd_doc.c correct chip ID found, device available 2307 -38 common/cmd_doc.c Read Error on boot device 2308 38 common/cmd_doc.c reading Image header from DOC device OK 2309 -39 common/cmd_doc.c Image header has bad magic number 2310 39 common/cmd_doc.c Image header has correct magic number 2311 -40 common/cmd_doc.c Error reading Image from DOC device 2312 40 common/cmd_doc.c Image header has correct magic number 2313 41 common/cmd_ide.c before loading a Image from a IDE device 2314 -42 common/cmd_ide.c Bad usage of "ide" command 2315 42 common/cmd_ide.c correct usage of "ide" command 2316 -43 common/cmd_ide.c No boot device 2317 43 common/cmd_ide.c boot device found 2318 -44 common/cmd_ide.c Device not available 2319 44 common/cmd_ide.c Device available 2320 -45 common/cmd_ide.c wrong partition selected 2321 45 common/cmd_ide.c partition selected 2322 -46 common/cmd_ide.c Unknown partition table 2323 46 common/cmd_ide.c valid partition table found 2324 -47 common/cmd_ide.c Invalid partition type 2325 47 common/cmd_ide.c correct partition type 2326 -48 common/cmd_ide.c Error reading Image Header on boot device 2327 48 common/cmd_ide.c reading Image Header from IDE device OK 2328 -49 common/cmd_ide.c Image header has bad magic number 2329 49 common/cmd_ide.c Image header has correct magic number 2330 -50 common/cmd_ide.c Image header has bad checksum 2331 50 common/cmd_ide.c Image header has correct checksum 2332 -51 common/cmd_ide.c Error reading Image from IDE device 2333 51 common/cmd_ide.c reading Image from IDE device OK 2334 52 common/cmd_nand.c before loading a Image from a NAND device 2335 -53 common/cmd_nand.c Bad usage of "nand" command 2336 53 common/cmd_nand.c correct usage of "nand" command 2337 -54 common/cmd_nand.c No boot device 2338 54 common/cmd_nand.c boot device found 2339 -55 common/cmd_nand.c Unknown Chip ID on boot device 2340 55 common/cmd_nand.c correct chip ID found, device available 2341 -56 common/cmd_nand.c Error reading Image Header on boot device 2342 56 common/cmd_nand.c reading Image Header from NAND device OK 2343 -57 common/cmd_nand.c Image header has bad magic number 2344 57 common/cmd_nand.c Image header has correct magic number 2345 -58 common/cmd_nand.c Error reading Image from NAND device 2346 58 common/cmd_nand.c reading Image from NAND device OK 2347 2348 -60 common/env_common.c Environment has a bad CRC, using default 2349 2350 64 net/eth.c starting with Ethernet configuration. 2351 -64 net/eth.c no Ethernet found. 2352 65 net/eth.c Ethernet found. 2353 2354 -80 common/cmd_net.c usage wrong 2355 80 common/cmd_net.c before calling net_loop() 2356 -81 common/cmd_net.c some error in net_loop() occurred 2357 81 common/cmd_net.c net_loop() back without error 2358 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2359 82 common/cmd_net.c trying automatic boot 2360 83 common/cmd_net.c running "source" command 2361 -83 common/cmd_net.c some error in automatic boot or "source" command 2362 84 common/cmd_net.c end without errors 2363 2364FIT uImage format: 2365 2366 Arg Where When 2367 100 common/cmd_bootm.c Kernel FIT Image has correct format 2368 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2369 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2370 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2371 102 common/cmd_bootm.c Kernel unit name specified 2372 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2373 103 common/cmd_bootm.c Found configuration node 2374 104 common/cmd_bootm.c Got kernel subimage node offset 2375 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2376 105 common/cmd_bootm.c Kernel subimage hash verification OK 2377 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2378 106 common/cmd_bootm.c Architecture check OK 2379 -106 common/cmd_bootm.c Kernel subimage has wrong type 2380 107 common/cmd_bootm.c Kernel subimage type OK 2381 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2382 108 common/cmd_bootm.c Got kernel subimage data/size 2383 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2384 -109 common/cmd_bootm.c Can't get kernel subimage type 2385 -110 common/cmd_bootm.c Can't get kernel subimage comp 2386 -111 common/cmd_bootm.c Can't get kernel subimage os 2387 -112 common/cmd_bootm.c Can't get kernel subimage load address 2388 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2389 2390 120 common/image.c Start initial ramdisk verification 2391 -120 common/image.c Ramdisk FIT image has incorrect format 2392 121 common/image.c Ramdisk FIT image has correct format 2393 122 common/image.c No ramdisk subimage unit name, using configuration 2394 -122 common/image.c Can't get configuration for ramdisk subimage 2395 123 common/image.c Ramdisk unit name specified 2396 -124 common/image.c Can't get ramdisk subimage node offset 2397 125 common/image.c Got ramdisk subimage node offset 2398 -125 common/image.c Ramdisk subimage hash verification failed 2399 126 common/image.c Ramdisk subimage hash verification OK 2400 -126 common/image.c Ramdisk subimage for unsupported architecture 2401 127 common/image.c Architecture check OK 2402 -127 common/image.c Can't get ramdisk subimage data/size 2403 128 common/image.c Got ramdisk subimage data/size 2404 129 common/image.c Can't get ramdisk load address 2405 -129 common/image.c Got ramdisk load address 2406 2407 -130 common/cmd_doc.c Incorrect FIT image format 2408 131 common/cmd_doc.c FIT image format OK 2409 2410 -140 common/cmd_ide.c Incorrect FIT image format 2411 141 common/cmd_ide.c FIT image format OK 2412 2413 -150 common/cmd_nand.c Incorrect FIT image format 2414 151 common/cmd_nand.c FIT image format OK 2415 2416- Standalone program support: 2417 CONFIG_STANDALONE_LOAD_ADDR 2418 2419 This option defines a board specific value for the 2420 address where standalone program gets loaded, thus 2421 overwriting the architecture dependent default 2422 settings. 2423 2424- Frame Buffer Address: 2425 CONFIG_FB_ADDR 2426 2427 Define CONFIG_FB_ADDR if you want to use specific 2428 address for frame buffer. This is typically the case 2429 when using a graphics controller has separate video 2430 memory. U-Boot will then place the frame buffer at 2431 the given address instead of dynamically reserving it 2432 in system RAM by calling lcd_setmem(), which grabs 2433 the memory for the frame buffer depending on the 2434 configured panel size. 2435 2436 Please see board_init_f function. 2437 2438- Automatic software updates via TFTP server 2439 CONFIG_UPDATE_TFTP 2440 CONFIG_UPDATE_TFTP_CNT_MAX 2441 CONFIG_UPDATE_TFTP_MSEC_MAX 2442 2443 These options enable and control the auto-update feature; 2444 for a more detailed description refer to doc/README.update. 2445 2446- MTD Support (mtdparts command, UBI support) 2447 CONFIG_MTD_DEVICE 2448 2449 Adds the MTD device infrastructure from the Linux kernel. 2450 Needed for mtdparts command support. 2451 2452 CONFIG_MTD_PARTITIONS 2453 2454 Adds the MTD partitioning infrastructure from the Linux 2455 kernel. Needed for UBI support. 2456 2457- UBI support 2458 CONFIG_MTD_UBI_WL_THRESHOLD 2459 This parameter defines the maximum difference between the highest 2460 erase counter value and the lowest erase counter value of eraseblocks 2461 of UBI devices. When this threshold is exceeded, UBI starts performing 2462 wear leveling by means of moving data from eraseblock with low erase 2463 counter to eraseblocks with high erase counter. 2464 2465 The default value should be OK for SLC NAND flashes, NOR flashes and 2466 other flashes which have eraseblock life-cycle 100000 or more. 2467 However, in case of MLC NAND flashes which typically have eraseblock 2468 life-cycle less than 10000, the threshold should be lessened (e.g., 2469 to 128 or 256, although it does not have to be power of 2). 2470 2471 default: 4096 2472 2473 CONFIG_MTD_UBI_BEB_LIMIT 2474 This option specifies the maximum bad physical eraseblocks UBI 2475 expects on the MTD device (per 1024 eraseblocks). If the 2476 underlying flash does not admit of bad eraseblocks (e.g. NOR 2477 flash), this value is ignored. 2478 2479 NAND datasheets often specify the minimum and maximum NVM 2480 (Number of Valid Blocks) for the flashes' endurance lifetime. 2481 The maximum expected bad eraseblocks per 1024 eraseblocks 2482 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2483 which gives 20 for most NANDs (MaxNVB is basically the total 2484 count of eraseblocks on the chip). 2485 2486 To put it differently, if this value is 20, UBI will try to 2487 reserve about 1.9% of physical eraseblocks for bad blocks 2488 handling. And that will be 1.9% of eraseblocks on the entire 2489 NAND chip, not just the MTD partition UBI attaches. This means 2490 that if you have, say, a NAND flash chip admits maximum 40 bad 2491 eraseblocks, and it is split on two MTD partitions of the same 2492 size, UBI will reserve 40 eraseblocks when attaching a 2493 partition. 2494 2495 default: 20 2496 2497 CONFIG_MTD_UBI_FASTMAP 2498 Fastmap is a mechanism which allows attaching an UBI device 2499 in nearly constant time. Instead of scanning the whole MTD device it 2500 only has to locate a checkpoint (called fastmap) on the device. 2501 The on-flash fastmap contains all information needed to attach 2502 the device. Using fastmap makes only sense on large devices where 2503 attaching by scanning takes long. UBI will not automatically install 2504 a fastmap on old images, but you can set the UBI parameter 2505 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2506 that fastmap-enabled images are still usable with UBI implementations 2507 without fastmap support. On typical flash devices the whole fastmap 2508 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2509 2510 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2511 Set this parameter to enable fastmap automatically on images 2512 without a fastmap. 2513 default: 0 2514 2515 CONFIG_MTD_UBI_FM_DEBUG 2516 Enable UBI fastmap debug 2517 default: 0 2518 2519- SPL framework 2520 CONFIG_SPL 2521 Enable building of SPL globally. 2522 2523 CONFIG_SPL_LDSCRIPT 2524 LDSCRIPT for linking the SPL binary. 2525 2526 CONFIG_SPL_MAX_FOOTPRINT 2527 Maximum size in memory allocated to the SPL, BSS included. 2528 When defined, the linker checks that the actual memory 2529 used by SPL from _start to __bss_end does not exceed it. 2530 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2531 must not be both defined at the same time. 2532 2533 CONFIG_SPL_MAX_SIZE 2534 Maximum size of the SPL image (text, data, rodata, and 2535 linker lists sections), BSS excluded. 2536 When defined, the linker checks that the actual size does 2537 not exceed it. 2538 2539 CONFIG_SPL_TEXT_BASE 2540 TEXT_BASE for linking the SPL binary. 2541 2542 CONFIG_SPL_RELOC_TEXT_BASE 2543 Address to relocate to. If unspecified, this is equal to 2544 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2545 2546 CONFIG_SPL_BSS_START_ADDR 2547 Link address for the BSS within the SPL binary. 2548 2549 CONFIG_SPL_BSS_MAX_SIZE 2550 Maximum size in memory allocated to the SPL BSS. 2551 When defined, the linker checks that the actual memory used 2552 by SPL from __bss_start to __bss_end does not exceed it. 2553 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2554 must not be both defined at the same time. 2555 2556 CONFIG_SPL_STACK 2557 Adress of the start of the stack SPL will use 2558 2559 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2560 When defined, SPL will panic() if the image it has 2561 loaded does not have a signature. 2562 Defining this is useful when code which loads images 2563 in SPL cannot guarantee that absolutely all read errors 2564 will be caught. 2565 An example is the LPC32XX MLC NAND driver, which will 2566 consider that a completely unreadable NAND block is bad, 2567 and thus should be skipped silently. 2568 2569 CONFIG_SPL_RELOC_STACK 2570 Adress of the start of the stack SPL will use after 2571 relocation. If unspecified, this is equal to 2572 CONFIG_SPL_STACK. 2573 2574 CONFIG_SYS_SPL_MALLOC_START 2575 Starting address of the malloc pool used in SPL. 2576 When this option is set the full malloc is used in SPL and 2577 it is set up by spl_init() and before that, the simple malloc() 2578 can be used if CONFIG_SYS_MALLOC_F is defined. 2579 2580 CONFIG_SYS_SPL_MALLOC_SIZE 2581 The size of the malloc pool used in SPL. 2582 2583 CONFIG_SPL_OS_BOOT 2584 Enable booting directly to an OS from SPL. 2585 See also: doc/README.falcon 2586 2587 CONFIG_SPL_DISPLAY_PRINT 2588 For ARM, enable an optional function to print more information 2589 about the running system. 2590 2591 CONFIG_SPL_INIT_MINIMAL 2592 Arch init code should be built for a very small image 2593 2594 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2595 Partition on the MMC to load U-Boot from when the MMC is being 2596 used in raw mode 2597 2598 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2599 Sector to load kernel uImage from when MMC is being 2600 used in raw mode (for Falcon mode) 2601 2602 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2603 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2604 Sector and number of sectors to load kernel argument 2605 parameters from when MMC is being used in raw mode 2606 (for falcon mode) 2607 2608 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2609 Partition on the MMC to load U-Boot from when the MMC is being 2610 used in fs mode 2611 2612 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2613 Filename to read to load U-Boot when reading from filesystem 2614 2615 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2616 Filename to read to load kernel uImage when reading 2617 from filesystem (for Falcon mode) 2618 2619 CONFIG_SPL_FS_LOAD_ARGS_NAME 2620 Filename to read to load kernel argument parameters 2621 when reading from filesystem (for Falcon mode) 2622 2623 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2624 Set this for NAND SPL on PPC mpc83xx targets, so that 2625 start.S waits for the rest of the SPL to load before 2626 continuing (the hardware starts execution after just 2627 loading the first page rather than the full 4K). 2628 2629 CONFIG_SPL_SKIP_RELOCATE 2630 Avoid SPL relocation 2631 2632 CONFIG_SPL_NAND_BASE 2633 Include nand_base.c in the SPL. Requires 2634 CONFIG_SPL_NAND_DRIVERS. 2635 2636 CONFIG_SPL_NAND_DRIVERS 2637 SPL uses normal NAND drivers, not minimal drivers. 2638 2639 CONFIG_SPL_NAND_ECC 2640 Include standard software ECC in the SPL 2641 2642 CONFIG_SPL_NAND_SIMPLE 2643 Support for NAND boot using simple NAND drivers that 2644 expose the cmd_ctrl() interface. 2645 2646 CONFIG_SPL_UBI 2647 Support for a lightweight UBI (fastmap) scanner and 2648 loader 2649 2650 CONFIG_SPL_NAND_RAW_ONLY 2651 Support to boot only raw u-boot.bin images. Use this only 2652 if you need to save space. 2653 2654 CONFIG_SPL_COMMON_INIT_DDR 2655 Set for common ddr init with serial presence detect in 2656 SPL binary. 2657 2658 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2659 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2660 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2661 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2662 CONFIG_SYS_NAND_ECCBYTES 2663 Defines the size and behavior of the NAND that SPL uses 2664 to read U-Boot 2665 2666 CONFIG_SPL_NAND_BOOT 2667 Add support NAND boot 2668 2669 CONFIG_SYS_NAND_U_BOOT_OFFS 2670 Location in NAND to read U-Boot from 2671 2672 CONFIG_SYS_NAND_U_BOOT_DST 2673 Location in memory to load U-Boot to 2674 2675 CONFIG_SYS_NAND_U_BOOT_SIZE 2676 Size of image to load 2677 2678 CONFIG_SYS_NAND_U_BOOT_START 2679 Entry point in loaded image to jump to 2680 2681 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2682 Define this if you need to first read the OOB and then the 2683 data. This is used, for example, on davinci platforms. 2684 2685 CONFIG_SPL_RAM_DEVICE 2686 Support for running image already present in ram, in SPL binary 2687 2688 CONFIG_SPL_PAD_TO 2689 Image offset to which the SPL should be padded before appending 2690 the SPL payload. By default, this is defined as 2691 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2692 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2693 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2694 2695 CONFIG_SPL_TARGET 2696 Final target image containing SPL and payload. Some SPLs 2697 use an arch-specific makefile fragment instead, for 2698 example if more than one image needs to be produced. 2699 2700 CONFIG_FIT_SPL_PRINT 2701 Printing information about a FIT image adds quite a bit of 2702 code to SPL. So this is normally disabled in SPL. Use this 2703 option to re-enable it. This will affect the output of the 2704 bootm command when booting a FIT image. 2705 2706- TPL framework 2707 CONFIG_TPL 2708 Enable building of TPL globally. 2709 2710 CONFIG_TPL_PAD_TO 2711 Image offset to which the TPL should be padded before appending 2712 the TPL payload. By default, this is defined as 2713 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2714 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2715 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2716 2717- Interrupt support (PPC): 2718 2719 There are common interrupt_init() and timer_interrupt() 2720 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2721 for CPU specific initialization. interrupt_init_cpu() 2722 should set decrementer_count to appropriate value. If 2723 CPU resets decrementer automatically after interrupt 2724 (ppc4xx) it should set decrementer_count to zero. 2725 timer_interrupt() calls timer_interrupt_cpu() for CPU 2726 specific handling. If board has watchdog / status_led 2727 / other_activity_monitor it works automatically from 2728 general timer_interrupt(). 2729 2730 2731Board initialization settings: 2732------------------------------ 2733 2734During Initialization u-boot calls a number of board specific functions 2735to allow the preparation of board specific prerequisites, e.g. pin setup 2736before drivers are initialized. To enable these callbacks the 2737following configuration macros have to be defined. Currently this is 2738architecture specific, so please check arch/your_architecture/lib/board.c 2739typically in board_init_f() and board_init_r(). 2740 2741- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2742- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2743- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2744- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2745 2746Configuration Settings: 2747----------------------- 2748 2749- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2750 Optionally it can be defined to support 64-bit memory commands. 2751 2752- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2753 undefine this when you're short of memory. 2754 2755- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2756 width of the commands listed in the 'help' command output. 2757 2758- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2759 prompt for user input. 2760 2761- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2762 2763- CONFIG_SYS_PBSIZE: Buffer size for Console output 2764 2765- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2766 2767- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2768 the application (usually a Linux kernel) when it is 2769 booted 2770 2771- CONFIG_SYS_BAUDRATE_TABLE: 2772 List of legal baudrate settings for this board. 2773 2774- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2775 Begin and End addresses of the area used by the 2776 simple memory test. 2777 2778- CONFIG_SYS_MEMTEST_SCRATCH: 2779 Scratch address used by the alternate memory test 2780 You only need to set this if address zero isn't writeable 2781 2782- CONFIG_SYS_MEM_RESERVE_SECURE 2783 Only implemented for ARMv8 for now. 2784 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2785 is substracted from total RAM and won't be reported to OS. 2786 This memory can be used as secure memory. A variable 2787 gd->arch.secure_ram is used to track the location. In systems 2788 the RAM base is not zero, or RAM is divided into banks, 2789 this variable needs to be recalcuated to get the address. 2790 2791- CONFIG_SYS_MEM_TOP_HIDE: 2792 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2793 this specified memory area will get subtracted from the top 2794 (end) of RAM and won't get "touched" at all by U-Boot. By 2795 fixing up gd->ram_size the Linux kernel should gets passed 2796 the now "corrected" memory size and won't touch it either. 2797 This should work for arch/ppc and arch/powerpc. Only Linux 2798 board ports in arch/powerpc with bootwrapper support that 2799 recalculate the memory size from the SDRAM controller setup 2800 will have to get fixed in Linux additionally. 2801 2802 This option can be used as a workaround for the 440EPx/GRx 2803 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2804 be touched. 2805 2806 WARNING: Please make sure that this value is a multiple of 2807 the Linux page size (normally 4k). If this is not the case, 2808 then the end address of the Linux memory will be located at a 2809 non page size aligned address and this could cause major 2810 problems. 2811 2812- CONFIG_SYS_LOADS_BAUD_CHANGE: 2813 Enable temporary baudrate change while serial download 2814 2815- CONFIG_SYS_SDRAM_BASE: 2816 Physical start address of SDRAM. _Must_ be 0 here. 2817 2818- CONFIG_SYS_FLASH_BASE: 2819 Physical start address of Flash memory. 2820 2821- CONFIG_SYS_MONITOR_BASE: 2822 Physical start address of boot monitor code (set by 2823 make config files to be same as the text base address 2824 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2825 CONFIG_SYS_FLASH_BASE when booting from flash. 2826 2827- CONFIG_SYS_MONITOR_LEN: 2828 Size of memory reserved for monitor code, used to 2829 determine _at_compile_time_ (!) if the environment is 2830 embedded within the U-Boot image, or in a separate 2831 flash sector. 2832 2833- CONFIG_SYS_MALLOC_LEN: 2834 Size of DRAM reserved for malloc() use. 2835 2836- CONFIG_SYS_MALLOC_F_LEN 2837 Size of the malloc() pool for use before relocation. If 2838 this is defined, then a very simple malloc() implementation 2839 will become available before relocation. The address is just 2840 below the global data, and the stack is moved down to make 2841 space. 2842 2843 This feature allocates regions with increasing addresses 2844 within the region. calloc() is supported, but realloc() 2845 is not available. free() is supported but does nothing. 2846 The memory will be freed (or in fact just forgotten) when 2847 U-Boot relocates itself. 2848 2849- CONFIG_SYS_MALLOC_SIMPLE 2850 Provides a simple and small malloc() and calloc() for those 2851 boards which do not use the full malloc in SPL (which is 2852 enabled with CONFIG_SYS_SPL_MALLOC_START). 2853 2854- CONFIG_SYS_NONCACHED_MEMORY: 2855 Size of non-cached memory area. This area of memory will be 2856 typically located right below the malloc() area and mapped 2857 uncached in the MMU. This is useful for drivers that would 2858 otherwise require a lot of explicit cache maintenance. For 2859 some drivers it's also impossible to properly maintain the 2860 cache. For example if the regions that need to be flushed 2861 are not a multiple of the cache-line size, *and* padding 2862 cannot be allocated between the regions to align them (i.e. 2863 if the HW requires a contiguous array of regions, and the 2864 size of each region is not cache-aligned), then a flush of 2865 one region may result in overwriting data that hardware has 2866 written to another region in the same cache-line. This can 2867 happen for example in network drivers where descriptors for 2868 buffers are typically smaller than the CPU cache-line (e.g. 2869 16 bytes vs. 32 or 64 bytes). 2870 2871 Non-cached memory is only supported on 32-bit ARM at present. 2872 2873- CONFIG_SYS_BOOTM_LEN: 2874 Normally compressed uImages are limited to an 2875 uncompressed size of 8 MBytes. If this is not enough, 2876 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2877 to adjust this setting to your needs. 2878 2879- CONFIG_SYS_BOOTMAPSZ: 2880 Maximum size of memory mapped by the startup code of 2881 the Linux kernel; all data that must be processed by 2882 the Linux kernel (bd_info, boot arguments, FDT blob if 2883 used) must be put below this limit, unless "bootm_low" 2884 environment variable is defined and non-zero. In such case 2885 all data for the Linux kernel must be between "bootm_low" 2886 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2887 variable "bootm_mapsize" will override the value of 2888 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2889 then the value in "bootm_size" will be used instead. 2890 2891- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2892 Enable initrd_high functionality. If defined then the 2893 initrd_high feature is enabled and the bootm ramdisk subcommand 2894 is enabled. 2895 2896- CONFIG_SYS_BOOT_GET_CMDLINE: 2897 Enables allocating and saving kernel cmdline in space between 2898 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2899 2900- CONFIG_SYS_BOOT_GET_KBD: 2901 Enables allocating and saving a kernel copy of the bd_info in 2902 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2903 2904- CONFIG_SYS_MAX_FLASH_BANKS: 2905 Max number of Flash memory banks 2906 2907- CONFIG_SYS_MAX_FLASH_SECT: 2908 Max number of sectors on a Flash chip 2909 2910- CONFIG_SYS_FLASH_ERASE_TOUT: 2911 Timeout for Flash erase operations (in ms) 2912 2913- CONFIG_SYS_FLASH_WRITE_TOUT: 2914 Timeout for Flash write operations (in ms) 2915 2916- CONFIG_SYS_FLASH_LOCK_TOUT 2917 Timeout for Flash set sector lock bit operation (in ms) 2918 2919- CONFIG_SYS_FLASH_UNLOCK_TOUT 2920 Timeout for Flash clear lock bits operation (in ms) 2921 2922- CONFIG_SYS_FLASH_PROTECTION 2923 If defined, hardware flash sectors protection is used 2924 instead of U-Boot software protection. 2925 2926- CONFIG_SYS_DIRECT_FLASH_TFTP: 2927 2928 Enable TFTP transfers directly to flash memory; 2929 without this option such a download has to be 2930 performed in two steps: (1) download to RAM, and (2) 2931 copy from RAM to flash. 2932 2933 The two-step approach is usually more reliable, since 2934 you can check if the download worked before you erase 2935 the flash, but in some situations (when system RAM is 2936 too limited to allow for a temporary copy of the 2937 downloaded image) this option may be very useful. 2938 2939- CONFIG_SYS_FLASH_CFI: 2940 Define if the flash driver uses extra elements in the 2941 common flash structure for storing flash geometry. 2942 2943- CONFIG_FLASH_CFI_DRIVER 2944 This option also enables the building of the cfi_flash driver 2945 in the drivers directory 2946 2947- CONFIG_FLASH_CFI_MTD 2948 This option enables the building of the cfi_mtd driver 2949 in the drivers directory. The driver exports CFI flash 2950 to the MTD layer. 2951 2952- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2953 Use buffered writes to flash. 2954 2955- CONFIG_FLASH_SPANSION_S29WS_N 2956 s29ws-n MirrorBit flash has non-standard addresses for buffered 2957 write commands. 2958 2959- CONFIG_SYS_FLASH_QUIET_TEST 2960 If this option is defined, the common CFI flash doesn't 2961 print it's warning upon not recognized FLASH banks. This 2962 is useful, if some of the configured banks are only 2963 optionally available. 2964 2965- CONFIG_FLASH_SHOW_PROGRESS 2966 If defined (must be an integer), print out countdown 2967 digits and dots. Recommended value: 45 (9..1) for 80 2968 column displays, 15 (3..1) for 40 column displays. 2969 2970- CONFIG_FLASH_VERIFY 2971 If defined, the content of the flash (destination) is compared 2972 against the source after the write operation. An error message 2973 will be printed when the contents are not identical. 2974 Please note that this option is useless in nearly all cases, 2975 since such flash programming errors usually are detected earlier 2976 while unprotecting/erasing/programming. Please only enable 2977 this option if you really know what you are doing. 2978 2979- CONFIG_SYS_RX_ETH_BUFFER: 2980 Defines the number of Ethernet receive buffers. On some 2981 Ethernet controllers it is recommended to set this value 2982 to 8 or even higher (EEPRO100 or 405 EMAC), since all 2983 buffers can be full shortly after enabling the interface 2984 on high Ethernet traffic. 2985 Defaults to 4 if not defined. 2986 2987- CONFIG_ENV_MAX_ENTRIES 2988 2989 Maximum number of entries in the hash table that is used 2990 internally to store the environment settings. The default 2991 setting is supposed to be generous and should work in most 2992 cases. This setting can be used to tune behaviour; see 2993 lib/hashtable.c for details. 2994 2995- CONFIG_ENV_FLAGS_LIST_DEFAULT 2996- CONFIG_ENV_FLAGS_LIST_STATIC 2997 Enable validation of the values given to environment variables when 2998 calling env set. Variables can be restricted to only decimal, 2999 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3000 the variables can also be restricted to IP address or MAC address. 3001 3002 The format of the list is: 3003 type_attribute = [s|d|x|b|i|m] 3004 access_attribute = [a|r|o|c] 3005 attributes = type_attribute[access_attribute] 3006 entry = variable_name[:attributes] 3007 list = entry[,list] 3008 3009 The type attributes are: 3010 s - String (default) 3011 d - Decimal 3012 x - Hexadecimal 3013 b - Boolean ([1yYtT|0nNfF]) 3014 i - IP address 3015 m - MAC address 3016 3017 The access attributes are: 3018 a - Any (default) 3019 r - Read-only 3020 o - Write-once 3021 c - Change-default 3022 3023 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3024 Define this to a list (string) to define the ".flags" 3025 environment variable in the default or embedded environment. 3026 3027 - CONFIG_ENV_FLAGS_LIST_STATIC 3028 Define this to a list (string) to define validation that 3029 should be done if an entry is not found in the ".flags" 3030 environment variable. To override a setting in the static 3031 list, simply add an entry for the same variable name to the 3032 ".flags" variable. 3033 3034 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3035 regular expression. This allows multiple variables to define the same 3036 flags without explicitly listing them for each variable. 3037 3038- CONFIG_ENV_ACCESS_IGNORE_FORCE 3039 If defined, don't allow the -f switch to env set override variable 3040 access flags. 3041 3042- CONFIG_USE_STDINT 3043 If stdint.h is available with your toolchain you can define this 3044 option to enable it. You can provide option 'USE_STDINT=1' when 3045 building U-Boot to enable this. 3046 3047The following definitions that deal with the placement and management 3048of environment data (variable area); in general, we support the 3049following configurations: 3050 3051- CONFIG_BUILD_ENVCRC: 3052 3053 Builds up envcrc with the target environment so that external utils 3054 may easily extract it and embed it in final U-Boot images. 3055 3056BE CAREFUL! The first access to the environment happens quite early 3057in U-Boot initialization (when we try to get the setting of for the 3058console baudrate). You *MUST* have mapped your NVRAM area then, or 3059U-Boot will hang. 3060 3061Please note that even with NVRAM we still use a copy of the 3062environment in RAM: we could work on NVRAM directly, but we want to 3063keep settings there always unmodified except somebody uses "saveenv" 3064to save the current settings. 3065 3066BE CAREFUL! For some special cases, the local device can not use 3067"saveenv" command. For example, the local device will get the 3068environment stored in a remote NOR flash by SRIO or PCIE link, 3069but it can not erase, write this NOR flash by SRIO or PCIE interface. 3070 3071- CONFIG_NAND_ENV_DST 3072 3073 Defines address in RAM to which the nand_spl code should copy the 3074 environment. If redundant environment is used, it will be copied to 3075 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3076 3077Please note that the environment is read-only until the monitor 3078has been relocated to RAM and a RAM copy of the environment has been 3079created; also, when using EEPROM you will have to use env_get_f() 3080until then to read environment variables. 3081 3082The environment is protected by a CRC32 checksum. Before the monitor 3083is relocated into RAM, as a result of a bad CRC you will be working 3084with the compiled-in default environment - *silently*!!! [This is 3085necessary, because the first environment variable we need is the 3086"baudrate" setting for the console - if we have a bad CRC, we don't 3087have any device yet where we could complain.] 3088 3089Note: once the monitor has been relocated, then it will complain if 3090the default environment is used; a new CRC is computed as soon as you 3091use the "saveenv" command to store a valid environment. 3092 3093- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3094 Echo the inverted Ethernet link state to the fault LED. 3095 3096 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3097 also needs to be defined. 3098 3099- CONFIG_SYS_FAULT_MII_ADDR: 3100 MII address of the PHY to check for the Ethernet link state. 3101 3102- CONFIG_NS16550_MIN_FUNCTIONS: 3103 Define this if you desire to only have use of the NS16550_init 3104 and NS16550_putc functions for the serial driver located at 3105 drivers/serial/ns16550.c. This option is useful for saving 3106 space for already greatly restricted images, including but not 3107 limited to NAND_SPL configurations. 3108 3109- CONFIG_DISPLAY_BOARDINFO 3110 Display information about the board that U-Boot is running on 3111 when U-Boot starts up. The board function checkboard() is called 3112 to do this. 3113 3114- CONFIG_DISPLAY_BOARDINFO_LATE 3115 Similar to the previous option, but display this information 3116 later, once stdio is running and output goes to the LCD, if 3117 present. 3118 3119- CONFIG_BOARD_SIZE_LIMIT: 3120 Maximum size of the U-Boot image. When defined, the 3121 build system checks that the actual size does not 3122 exceed it. 3123 3124Low Level (hardware related) configuration options: 3125--------------------------------------------------- 3126 3127- CONFIG_SYS_CACHELINE_SIZE: 3128 Cache Line Size of the CPU. 3129 3130- CONFIG_SYS_CCSRBAR_DEFAULT: 3131 Default (power-on reset) physical address of CCSR on Freescale 3132 PowerPC SOCs. 3133 3134- CONFIG_SYS_CCSRBAR: 3135 Virtual address of CCSR. On a 32-bit build, this is typically 3136 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3137 3138- CONFIG_SYS_CCSRBAR_PHYS: 3139 Physical address of CCSR. CCSR can be relocated to a new 3140 physical address, if desired. In this case, this macro should 3141 be set to that address. Otherwise, it should be set to the 3142 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3143 is typically relocated on 36-bit builds. It is recommended 3144 that this macro be defined via the _HIGH and _LOW macros: 3145 3146 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3147 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3148 3149- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3150 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3151 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3152 used in assembly code, so it must not contain typecasts or 3153 integer size suffixes (e.g. "ULL"). 3154 3155- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3156 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3157 used in assembly code, so it must not contain typecasts or 3158 integer size suffixes (e.g. "ULL"). 3159 3160- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3161 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3162 forced to a value that ensures that CCSR is not relocated. 3163 3164- Floppy Disk Support: 3165 CONFIG_SYS_FDC_DRIVE_NUMBER 3166 3167 the default drive number (default value 0) 3168 3169 CONFIG_SYS_ISA_IO_STRIDE 3170 3171 defines the spacing between FDC chipset registers 3172 (default value 1) 3173 3174 CONFIG_SYS_ISA_IO_OFFSET 3175 3176 defines the offset of register from address. It 3177 depends on which part of the data bus is connected to 3178 the FDC chipset. (default value 0) 3179 3180 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3181 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3182 default value. 3183 3184 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3185 fdc_hw_init() is called at the beginning of the FDC 3186 setup. fdc_hw_init() must be provided by the board 3187 source code. It is used to make hardware-dependent 3188 initializations. 3189 3190- CONFIG_IDE_AHB: 3191 Most IDE controllers were designed to be connected with PCI 3192 interface. Only few of them were designed for AHB interface. 3193 When software is doing ATA command and data transfer to 3194 IDE devices through IDE-AHB controller, some additional 3195 registers accessing to these kind of IDE-AHB controller 3196 is required. 3197 3198- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3199 DO NOT CHANGE unless you know exactly what you're 3200 doing! (11-4) [MPC8xx systems only] 3201 3202- CONFIG_SYS_INIT_RAM_ADDR: 3203 3204 Start address of memory area that can be used for 3205 initial data and stack; please note that this must be 3206 writable memory that is working WITHOUT special 3207 initialization, i. e. you CANNOT use normal RAM which 3208 will become available only after programming the 3209 memory controller and running certain initialization 3210 sequences. 3211 3212 U-Boot uses the following memory types: 3213 - MPC8xx: IMMR (internal memory of the CPU) 3214 3215- CONFIG_SYS_GBL_DATA_OFFSET: 3216 3217 Offset of the initial data structure in the memory 3218 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3219 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3220 data is located at the end of the available space 3221 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3222 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3223 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3224 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3225 3226 Note: 3227 On the MPC824X (or other systems that use the data 3228 cache for initial memory) the address chosen for 3229 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3230 point to an otherwise UNUSED address space between 3231 the top of RAM and the start of the PCI space. 3232 3233- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3234 3235- CONFIG_SYS_OR_TIMING_SDRAM: 3236 SDRAM timing 3237 3238- CONFIG_SYS_MAMR_PTA: 3239 periodic timer for refresh 3240 3241- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3242 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3243 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3244 CONFIG_SYS_BR1_PRELIM: 3245 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3246 3247- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3248 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3249 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3250 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3251 3252- CONFIG_PCI_ENUM_ONLY 3253 Only scan through and get the devices on the buses. 3254 Don't do any setup work, presumably because someone or 3255 something has already done it, and we don't need to do it 3256 a second time. Useful for platforms that are pre-booted 3257 by coreboot or similar. 3258 3259- CONFIG_PCI_INDIRECT_BRIDGE: 3260 Enable support for indirect PCI bridges. 3261 3262- CONFIG_SYS_SRIO: 3263 Chip has SRIO or not 3264 3265- CONFIG_SRIO1: 3266 Board has SRIO 1 port available 3267 3268- CONFIG_SRIO2: 3269 Board has SRIO 2 port available 3270 3271- CONFIG_SRIO_PCIE_BOOT_MASTER 3272 Board can support master function for Boot from SRIO and PCIE 3273 3274- CONFIG_SYS_SRIOn_MEM_VIRT: 3275 Virtual Address of SRIO port 'n' memory region 3276 3277- CONFIG_SYS_SRIOn_MEM_PHYS: 3278 Physical Address of SRIO port 'n' memory region 3279 3280- CONFIG_SYS_SRIOn_MEM_SIZE: 3281 Size of SRIO port 'n' memory region 3282 3283- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3284 Defined to tell the NAND controller that the NAND chip is using 3285 a 16 bit bus. 3286 Not all NAND drivers use this symbol. 3287 Example of drivers that use it: 3288 - drivers/mtd/nand/ndfc.c 3289 - drivers/mtd/nand/mxc_nand.c 3290 3291- CONFIG_SYS_NDFC_EBC0_CFG 3292 Sets the EBC0_CFG register for the NDFC. If not defined 3293 a default value will be used. 3294 3295- CONFIG_SPD_EEPROM 3296 Get DDR timing information from an I2C EEPROM. Common 3297 with pluggable memory modules such as SODIMMs 3298 3299 SPD_EEPROM_ADDRESS 3300 I2C address of the SPD EEPROM 3301 3302- CONFIG_SYS_SPD_BUS_NUM 3303 If SPD EEPROM is on an I2C bus other than the first 3304 one, specify here. Note that the value must resolve 3305 to something your driver can deal with. 3306 3307- CONFIG_SYS_DDR_RAW_TIMING 3308 Get DDR timing information from other than SPD. Common with 3309 soldered DDR chips onboard without SPD. DDR raw timing 3310 parameters are extracted from datasheet and hard-coded into 3311 header files or board specific files. 3312 3313- CONFIG_FSL_DDR_INTERACTIVE 3314 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3315 3316- CONFIG_FSL_DDR_SYNC_REFRESH 3317 Enable sync of refresh for multiple controllers. 3318 3319- CONFIG_FSL_DDR_BIST 3320 Enable built-in memory test for Freescale DDR controllers. 3321 3322- CONFIG_SYS_83XX_DDR_USES_CS0 3323 Only for 83xx systems. If specified, then DDR should 3324 be configured using CS0 and CS1 instead of CS2 and CS3. 3325 3326- CONFIG_RMII 3327 Enable RMII mode for all FECs. 3328 Note that this is a global option, we can't 3329 have one FEC in standard MII mode and another in RMII mode. 3330 3331- CONFIG_CRC32_VERIFY 3332 Add a verify option to the crc32 command. 3333 The syntax is: 3334 3335 => crc32 -v <address> <count> <crc32> 3336 3337 Where address/count indicate a memory area 3338 and crc32 is the correct crc32 which the 3339 area should have. 3340 3341- CONFIG_LOOPW 3342 Add the "loopw" memory command. This only takes effect if 3343 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3344 3345- CONFIG_MX_CYCLIC 3346 Add the "mdc" and "mwc" memory commands. These are cyclic 3347 "md/mw" commands. 3348 Examples: 3349 3350 => mdc.b 10 4 500 3351 This command will print 4 bytes (10,11,12,13) each 500 ms. 3352 3353 => mwc.l 100 12345678 10 3354 This command will write 12345678 to address 100 all 10 ms. 3355 3356 This only takes effect if the memory commands are activated 3357 globally (CONFIG_CMD_MEMORY). 3358 3359- CONFIG_SKIP_LOWLEVEL_INIT 3360 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3361 low level initializations (like setting up the memory 3362 controller) are omitted and/or U-Boot does not 3363 relocate itself into RAM. 3364 3365 Normally this variable MUST NOT be defined. The only 3366 exception is when U-Boot is loaded (to RAM) by some 3367 other boot loader or by a debugger which performs 3368 these initializations itself. 3369 3370- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3371 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3372 to be skipped. The normal CP15 init (such as enabling the 3373 instruction cache) is still performed. 3374 3375- CONFIG_SPL_BUILD 3376 Modifies the behaviour of start.S when compiling a loader 3377 that is executed before the actual U-Boot. E.g. when 3378 compiling a NAND SPL. 3379 3380- CONFIG_TPL_BUILD 3381 Modifies the behaviour of start.S when compiling a loader 3382 that is executed after the SPL and before the actual U-Boot. 3383 It is loaded by the SPL. 3384 3385- CONFIG_SYS_MPC85XX_NO_RESETVEC 3386 Only for 85xx systems. If this variable is specified, the section 3387 .resetvec is not kept and the section .bootpg is placed in the 3388 previous 4k of the .text section. 3389 3390- CONFIG_ARCH_MAP_SYSMEM 3391 Generally U-Boot (and in particular the md command) uses 3392 effective address. It is therefore not necessary to regard 3393 U-Boot address as virtual addresses that need to be translated 3394 to physical addresses. However, sandbox requires this, since 3395 it maintains its own little RAM buffer which contains all 3396 addressable memory. This option causes some memory accesses 3397 to be mapped through map_sysmem() / unmap_sysmem(). 3398 3399- CONFIG_X86_RESET_VECTOR 3400 If defined, the x86 reset vector code is included. This is not 3401 needed when U-Boot is running from Coreboot. 3402 3403- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3404 Option to disable subpage write in NAND driver 3405 driver that uses this: 3406 drivers/mtd/nand/davinci_nand.c 3407 3408Freescale QE/FMAN Firmware Support: 3409----------------------------------- 3410 3411The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3412loading of "firmware", which is encoded in the QE firmware binary format. 3413This firmware often needs to be loaded during U-Boot booting, so macros 3414are used to identify the storage device (NOR flash, SPI, etc) and the address 3415within that device. 3416 3417- CONFIG_SYS_FMAN_FW_ADDR 3418 The address in the storage device where the FMAN microcode is located. The 3419 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3420 is also specified. 3421 3422- CONFIG_SYS_QE_FW_ADDR 3423 The address in the storage device where the QE microcode is located. The 3424 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3425 is also specified. 3426 3427- CONFIG_SYS_QE_FMAN_FW_LENGTH 3428 The maximum possible size of the firmware. The firmware binary format 3429 has a field that specifies the actual size of the firmware, but it 3430 might not be possible to read any part of the firmware unless some 3431 local storage is allocated to hold the entire firmware first. 3432 3433- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3434 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3435 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3436 virtual address in NOR flash. 3437 3438- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3439 Specifies that QE/FMAN firmware is located in NAND flash. 3440 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3441 3442- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3443 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3444 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3445 3446- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3447 Specifies that QE/FMAN firmware is located in the remote (master) 3448 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3449 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3450 window->master inbound window->master LAW->the ucode address in 3451 master's memory space. 3452 3453Freescale Layerscape Management Complex Firmware Support: 3454--------------------------------------------------------- 3455The Freescale Layerscape Management Complex (MC) supports the loading of 3456"firmware". 3457This firmware often needs to be loaded during U-Boot booting, so macros 3458are used to identify the storage device (NOR flash, SPI, etc) and the address 3459within that device. 3460 3461- CONFIG_FSL_MC_ENET 3462 Enable the MC driver for Layerscape SoCs. 3463 3464Freescale Layerscape Debug Server Support: 3465------------------------------------------- 3466The Freescale Layerscape Debug Server Support supports the loading of 3467"Debug Server firmware" and triggering SP boot-rom. 3468This firmware often needs to be loaded during U-Boot booting. 3469 3470- CONFIG_SYS_MC_RSV_MEM_ALIGN 3471 Define alignment of reserved memory MC requires 3472 3473Reproducible builds 3474------------------- 3475 3476In order to achieve reproducible builds, timestamps used in the U-Boot build 3477process have to be set to a fixed value. 3478 3479This is done using the SOURCE_DATE_EPOCH environment variable. 3480SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3481option for U-Boot or an environment variable in U-Boot. 3482 3483SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3484 3485Building the Software: 3486====================== 3487 3488Building U-Boot has been tested in several native build environments 3489and in many different cross environments. Of course we cannot support 3490all possibly existing versions of cross development tools in all 3491(potentially obsolete) versions. In case of tool chain problems we 3492recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3493which is extensively used to build and test U-Boot. 3494 3495If you are not using a native environment, it is assumed that you 3496have GNU cross compiling tools available in your path. In this case, 3497you must set the environment variable CROSS_COMPILE in your shell. 3498Note that no changes to the Makefile or any other source files are 3499necessary. For example using the ELDK on a 4xx CPU, please enter: 3500 3501 $ CROSS_COMPILE=ppc_4xx- 3502 $ export CROSS_COMPILE 3503 3504Note: If you wish to generate Windows versions of the utilities in 3505 the tools directory you can use the MinGW toolchain 3506 (http://www.mingw.org). Set your HOST tools to the MinGW 3507 toolchain and execute 'make tools'. For example: 3508 3509 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3510 3511 Binaries such as tools/mkimage.exe will be created which can 3512 be executed on computers running Windows. 3513 3514U-Boot is intended to be simple to build. After installing the 3515sources you must configure U-Boot for one specific board type. This 3516is done by typing: 3517 3518 make NAME_defconfig 3519 3520where "NAME_defconfig" is the name of one of the existing configu- 3521rations; see boards.cfg for supported names. 3522 3523Note: for some board special configuration names may exist; check if 3524 additional information is available from the board vendor; for 3525 instance, the TQM823L systems are available without (standard) 3526 or with LCD support. You can select such additional "features" 3527 when choosing the configuration, i. e. 3528 3529 make TQM823L_defconfig 3530 - will configure for a plain TQM823L, i. e. no LCD support 3531 3532 make TQM823L_LCD_defconfig 3533 - will configure for a TQM823L with U-Boot console on LCD 3534 3535 etc. 3536 3537 3538Finally, type "make all", and you should get some working U-Boot 3539images ready for download to / installation on your system: 3540 3541- "u-boot.bin" is a raw binary image 3542- "u-boot" is an image in ELF binary format 3543- "u-boot.srec" is in Motorola S-Record format 3544 3545By default the build is performed locally and the objects are saved 3546in the source directory. One of the two methods can be used to change 3547this behavior and build U-Boot to some external directory: 3548 35491. Add O= to the make command line invocations: 3550 3551 make O=/tmp/build distclean 3552 make O=/tmp/build NAME_defconfig 3553 make O=/tmp/build all 3554 35552. Set environment variable KBUILD_OUTPUT to point to the desired location: 3556 3557 export KBUILD_OUTPUT=/tmp/build 3558 make distclean 3559 make NAME_defconfig 3560 make all 3561 3562Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3563variable. 3564 3565User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3566setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3567For example to treat all compiler warnings as errors: 3568 3569 make KCFLAGS=-Werror 3570 3571Please be aware that the Makefiles assume you are using GNU make, so 3572for instance on NetBSD you might need to use "gmake" instead of 3573native "make". 3574 3575 3576If the system board that you have is not listed, then you will need 3577to port U-Boot to your hardware platform. To do this, follow these 3578steps: 3579 35801. Create a new directory to hold your board specific code. Add any 3581 files you need. In your board directory, you will need at least 3582 the "Makefile" and a "<board>.c". 35832. Create a new configuration file "include/configs/<board>.h" for 3584 your board. 35853. If you're porting U-Boot to a new CPU, then also create a new 3586 directory to hold your CPU specific code. Add any files you need. 35874. Run "make <board>_defconfig" with your new name. 35885. Type "make", and you should get a working "u-boot.srec" file 3589 to be installed on your target system. 35906. Debug and solve any problems that might arise. 3591 [Of course, this last step is much harder than it sounds.] 3592 3593 3594Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3595============================================================== 3596 3597If you have modified U-Boot sources (for instance added a new board 3598or support for new devices, a new CPU, etc.) you are expected to 3599provide feedback to the other developers. The feedback normally takes 3600the form of a "patch", i. e. a context diff against a certain (latest 3601official or latest in the git repository) version of U-Boot sources. 3602 3603But before you submit such a patch, please verify that your modifi- 3604cation did not break existing code. At least make sure that *ALL* of 3605the supported boards compile WITHOUT ANY compiler warnings. To do so, 3606just run the buildman script (tools/buildman/buildman), which will 3607configure and build U-Boot for ALL supported system. Be warned, this 3608will take a while. Please see the buildman README, or run 'buildman -H' 3609for documentation. 3610 3611 3612See also "U-Boot Porting Guide" below. 3613 3614 3615Monitor Commands - Overview: 3616============================ 3617 3618go - start application at address 'addr' 3619run - run commands in an environment variable 3620bootm - boot application image from memory 3621bootp - boot image via network using BootP/TFTP protocol 3622bootz - boot zImage from memory 3623tftpboot- boot image via network using TFTP protocol 3624 and env variables "ipaddr" and "serverip" 3625 (and eventually "gatewayip") 3626tftpput - upload a file via network using TFTP protocol 3627rarpboot- boot image via network using RARP/TFTP protocol 3628diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3629loads - load S-Record file over serial line 3630loadb - load binary file over serial line (kermit mode) 3631md - memory display 3632mm - memory modify (auto-incrementing) 3633nm - memory modify (constant address) 3634mw - memory write (fill) 3635cp - memory copy 3636cmp - memory compare 3637crc32 - checksum calculation 3638i2c - I2C sub-system 3639sspi - SPI utility commands 3640base - print or set address offset 3641printenv- print environment variables 3642setenv - set environment variables 3643saveenv - save environment variables to persistent storage 3644protect - enable or disable FLASH write protection 3645erase - erase FLASH memory 3646flinfo - print FLASH memory information 3647nand - NAND memory operations (see doc/README.nand) 3648bdinfo - print Board Info structure 3649iminfo - print header information for application image 3650coninfo - print console devices and informations 3651ide - IDE sub-system 3652loop - infinite loop on address range 3653loopw - infinite write loop on address range 3654mtest - simple RAM test 3655icache - enable or disable instruction cache 3656dcache - enable or disable data cache 3657reset - Perform RESET of the CPU 3658echo - echo args to console 3659version - print monitor version 3660help - print online help 3661? - alias for 'help' 3662 3663 3664Monitor Commands - Detailed Description: 3665======================================== 3666 3667TODO. 3668 3669For now: just type "help <command>". 3670 3671 3672Environment Variables: 3673====================== 3674 3675U-Boot supports user configuration using Environment Variables which 3676can be made persistent by saving to Flash memory. 3677 3678Environment Variables are set using "setenv", printed using 3679"printenv", and saved to Flash using "saveenv". Using "setenv" 3680without a value can be used to delete a variable from the 3681environment. As long as you don't save the environment you are 3682working with an in-memory copy. In case the Flash area containing the 3683environment is erased by accident, a default environment is provided. 3684 3685Some configuration options can be set using Environment Variables. 3686 3687List of environment variables (most likely not complete): 3688 3689 baudrate - see CONFIG_BAUDRATE 3690 3691 bootdelay - see CONFIG_BOOTDELAY 3692 3693 bootcmd - see CONFIG_BOOTCOMMAND 3694 3695 bootargs - Boot arguments when booting an RTOS image 3696 3697 bootfile - Name of the image to load with TFTP 3698 3699 bootm_low - Memory range available for image processing in the bootm 3700 command can be restricted. This variable is given as 3701 a hexadecimal number and defines lowest address allowed 3702 for use by the bootm command. See also "bootm_size" 3703 environment variable. Address defined by "bootm_low" is 3704 also the base of the initial memory mapping for the Linux 3705 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3706 bootm_mapsize. 3707 3708 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3709 This variable is given as a hexadecimal number and it 3710 defines the size of the memory region starting at base 3711 address bootm_low that is accessible by the Linux kernel 3712 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3713 as the default value if it is defined, and bootm_size is 3714 used otherwise. 3715 3716 bootm_size - Memory range available for image processing in the bootm 3717 command can be restricted. This variable is given as 3718 a hexadecimal number and defines the size of the region 3719 allowed for use by the bootm command. See also "bootm_low" 3720 environment variable. 3721 3722 updatefile - Location of the software update file on a TFTP server, used 3723 by the automatic software update feature. Please refer to 3724 documentation in doc/README.update for more details. 3725 3726 autoload - if set to "no" (any string beginning with 'n'), 3727 "bootp" will just load perform a lookup of the 3728 configuration from the BOOTP server, but not try to 3729 load any image using TFTP 3730 3731 autostart - if set to "yes", an image loaded using the "bootp", 3732 "rarpboot", "tftpboot" or "diskboot" commands will 3733 be automatically started (by internally calling 3734 "bootm") 3735 3736 If set to "no", a standalone image passed to the 3737 "bootm" command will be copied to the load address 3738 (and eventually uncompressed), but NOT be started. 3739 This can be used to load and uncompress arbitrary 3740 data. 3741 3742 fdt_high - if set this restricts the maximum address that the 3743 flattened device tree will be copied into upon boot. 3744 For example, if you have a system with 1 GB memory 3745 at physical address 0x10000000, while Linux kernel 3746 only recognizes the first 704 MB as low memory, you 3747 may need to set fdt_high as 0x3C000000 to have the 3748 device tree blob be copied to the maximum address 3749 of the 704 MB low memory, so that Linux kernel can 3750 access it during the boot procedure. 3751 3752 If this is set to the special value 0xFFFFFFFF then 3753 the fdt will not be copied at all on boot. For this 3754 to work it must reside in writable memory, have 3755 sufficient padding on the end of it for u-boot to 3756 add the information it needs into it, and the memory 3757 must be accessible by the kernel. 3758 3759 fdtcontroladdr- if set this is the address of the control flattened 3760 device tree used by U-Boot when CONFIG_OF_CONTROL is 3761 defined. 3762 3763 i2cfast - (PPC405GP|PPC405EP only) 3764 if set to 'y' configures Linux I2C driver for fast 3765 mode (400kHZ). This environment variable is used in 3766 initialization code. So, for changes to be effective 3767 it must be saved and board must be reset. 3768 3769 initrd_high - restrict positioning of initrd images: 3770 If this variable is not set, initrd images will be 3771 copied to the highest possible address in RAM; this 3772 is usually what you want since it allows for 3773 maximum initrd size. If for some reason you want to 3774 make sure that the initrd image is loaded below the 3775 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3776 variable to a value of "no" or "off" or "0". 3777 Alternatively, you can set it to a maximum upper 3778 address to use (U-Boot will still check that it 3779 does not overwrite the U-Boot stack and data). 3780 3781 For instance, when you have a system with 16 MB 3782 RAM, and want to reserve 4 MB from use by Linux, 3783 you can do this by adding "mem=12M" to the value of 3784 the "bootargs" variable. However, now you must make 3785 sure that the initrd image is placed in the first 3786 12 MB as well - this can be done with 3787 3788 setenv initrd_high 00c00000 3789 3790 If you set initrd_high to 0xFFFFFFFF, this is an 3791 indication to U-Boot that all addresses are legal 3792 for the Linux kernel, including addresses in flash 3793 memory. In this case U-Boot will NOT COPY the 3794 ramdisk at all. This may be useful to reduce the 3795 boot time on your system, but requires that this 3796 feature is supported by your Linux kernel. 3797 3798 ipaddr - IP address; needed for tftpboot command 3799 3800 loadaddr - Default load address for commands like "bootp", 3801 "rarpboot", "tftpboot", "loadb" or "diskboot" 3802 3803 loads_echo - see CONFIG_LOADS_ECHO 3804 3805 serverip - TFTP server IP address; needed for tftpboot command 3806 3807 bootretry - see CONFIG_BOOT_RETRY_TIME 3808 3809 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3810 3811 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3812 3813 ethprime - controls which interface is used first. 3814 3815 ethact - controls which interface is currently active. 3816 For example you can do the following 3817 3818 => setenv ethact FEC 3819 => ping 192.168.0.1 # traffic sent on FEC 3820 => setenv ethact SCC 3821 => ping 10.0.0.1 # traffic sent on SCC 3822 3823 ethrotate - When set to "no" U-Boot does not go through all 3824 available network interfaces. 3825 It just stays at the currently selected interface. 3826 3827 netretry - When set to "no" each network operation will 3828 either succeed or fail without retrying. 3829 When set to "once" the network operation will 3830 fail when all the available network interfaces 3831 are tried once without success. 3832 Useful on scripts which control the retry operation 3833 themselves. 3834 3835 npe_ucode - set load address for the NPE microcode 3836 3837 silent_linux - If set then Linux will be told to boot silently, by 3838 changing the console to be empty. If "yes" it will be 3839 made silent. If "no" it will not be made silent. If 3840 unset, then it will be made silent if the U-Boot console 3841 is silent. 3842 3843 tftpsrcp - If this is set, the value is used for TFTP's 3844 UDP source port. 3845 3846 tftpdstp - If this is set, the value is used for TFTP's UDP 3847 destination port instead of the Well Know Port 69. 3848 3849 tftpblocksize - Block size to use for TFTP transfers; if not set, 3850 we use the TFTP server's default block size 3851 3852 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3853 seconds, minimum value is 1000 = 1 second). Defines 3854 when a packet is considered to be lost so it has to 3855 be retransmitted. The default is 5000 = 5 seconds. 3856 Lowering this value may make downloads succeed 3857 faster in networks with high packet loss rates or 3858 with unreliable TFTP servers. 3859 3860 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3861 unit, minimum value = 0). Defines how many timeouts 3862 can happen during a single file transfer before that 3863 transfer is aborted. The default is 10, and 0 means 3864 'no timeouts allowed'. Increasing this value may help 3865 downloads succeed with high packet loss rates, or with 3866 unreliable TFTP servers or client hardware. 3867 3868 vlan - When set to a value < 4095 the traffic over 3869 Ethernet is encapsulated/received over 802.1q 3870 VLAN tagged frames. 3871 3872 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3873 Unsigned value, in milliseconds. If not set, the period will 3874 be either the default (28000), or a value based on 3875 CONFIG_NET_RETRY_COUNT, if defined. This value has 3876 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3877 3878The following image location variables contain the location of images 3879used in booting. The "Image" column gives the role of the image and is 3880not an environment variable name. The other columns are environment 3881variable names. "File Name" gives the name of the file on a TFTP 3882server, "RAM Address" gives the location in RAM the image will be 3883loaded to, and "Flash Location" gives the image's address in NOR 3884flash or offset in NAND flash. 3885 3886*Note* - these variables don't have to be defined for all boards, some 3887boards currently use other variables for these purposes, and some 3888boards use these variables for other purposes. 3889 3890Image File Name RAM Address Flash Location 3891----- --------- ----------- -------------- 3892u-boot u-boot u-boot_addr_r u-boot_addr 3893Linux kernel bootfile kernel_addr_r kernel_addr 3894device tree blob fdtfile fdt_addr_r fdt_addr 3895ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3896 3897The following environment variables may be used and automatically 3898updated by the network boot commands ("bootp" and "rarpboot"), 3899depending the information provided by your boot server: 3900 3901 bootfile - see above 3902 dnsip - IP address of your Domain Name Server 3903 dnsip2 - IP address of your secondary Domain Name Server 3904 gatewayip - IP address of the Gateway (Router) to use 3905 hostname - Target hostname 3906 ipaddr - see above 3907 netmask - Subnet Mask 3908 rootpath - Pathname of the root filesystem on the NFS server 3909 serverip - see above 3910 3911 3912There are two special Environment Variables: 3913 3914 serial# - contains hardware identification information such 3915 as type string and/or serial number 3916 ethaddr - Ethernet address 3917 3918These variables can be set only once (usually during manufacturing of 3919the board). U-Boot refuses to delete or overwrite these variables 3920once they have been set once. 3921 3922 3923Further special Environment Variables: 3924 3925 ver - Contains the U-Boot version string as printed 3926 with the "version" command. This variable is 3927 readonly (see CONFIG_VERSION_VARIABLE). 3928 3929 3930Please note that changes to some configuration parameters may take 3931only effect after the next boot (yes, that's just like Windoze :-). 3932 3933 3934Callback functions for environment variables: 3935--------------------------------------------- 3936 3937For some environment variables, the behavior of u-boot needs to change 3938when their values are changed. This functionality allows functions to 3939be associated with arbitrary variables. On creation, overwrite, or 3940deletion, the callback will provide the opportunity for some side 3941effect to happen or for the change to be rejected. 3942 3943The callbacks are named and associated with a function using the 3944U_BOOT_ENV_CALLBACK macro in your board or driver code. 3945 3946These callbacks are associated with variables in one of two ways. The 3947static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3948in the board configuration to a string that defines a list of 3949associations. The list must be in the following format: 3950 3951 entry = variable_name[:callback_name] 3952 list = entry[,list] 3953 3954If the callback name is not specified, then the callback is deleted. 3955Spaces are also allowed anywhere in the list. 3956 3957Callbacks can also be associated by defining the ".callbacks" variable 3958with the same list format above. Any association in ".callbacks" will 3959override any association in the static list. You can define 3960CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 3961".callbacks" environment variable in the default or embedded environment. 3962 3963If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3964regular expression. This allows multiple variables to be connected to 3965the same callback without explicitly listing them all out. 3966 3967 3968Command Line Parsing: 3969===================== 3970 3971There are two different command line parsers available with U-Boot: 3972the old "simple" one, and the much more powerful "hush" shell: 3973 3974Old, simple command line parser: 3975-------------------------------- 3976 3977- supports environment variables (through setenv / saveenv commands) 3978- several commands on one line, separated by ';' 3979- variable substitution using "... ${name} ..." syntax 3980- special characters ('$', ';') can be escaped by prefixing with '\', 3981 for example: 3982 setenv bootcmd bootm \${address} 3983- You can also escape text by enclosing in single apostrophes, for example: 3984 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 3985 3986Hush shell: 3987----------- 3988 3989- similar to Bourne shell, with control structures like 3990 if...then...else...fi, for...do...done; while...do...done, 3991 until...do...done, ... 3992- supports environment ("global") variables (through setenv / saveenv 3993 commands) and local shell variables (through standard shell syntax 3994 "name=value"); only environment variables can be used with "run" 3995 command 3996 3997General rules: 3998-------------- 3999 4000(1) If a command line (or an environment variable executed by a "run" 4001 command) contains several commands separated by semicolon, and 4002 one of these commands fails, then the remaining commands will be 4003 executed anyway. 4004 4005(2) If you execute several variables with one call to run (i. e. 4006 calling run with a list of variables as arguments), any failing 4007 command will cause "run" to terminate, i. e. the remaining 4008 variables are not executed. 4009 4010Note for Redundant Ethernet Interfaces: 4011======================================= 4012 4013Some boards come with redundant Ethernet interfaces; U-Boot supports 4014such configurations and is capable of automatic selection of a 4015"working" interface when needed. MAC assignment works as follows: 4016 4017Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4018MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4019"eth1addr" (=>eth1), "eth2addr", ... 4020 4021If the network interface stores some valid MAC address (for instance 4022in SROM), this is used as default address if there is NO correspon- 4023ding setting in the environment; if the corresponding environment 4024variable is set, this overrides the settings in the card; that means: 4025 4026o If the SROM has a valid MAC address, and there is no address in the 4027 environment, the SROM's address is used. 4028 4029o If there is no valid address in the SROM, and a definition in the 4030 environment exists, then the value from the environment variable is 4031 used. 4032 4033o If both the SROM and the environment contain a MAC address, and 4034 both addresses are the same, this MAC address is used. 4035 4036o If both the SROM and the environment contain a MAC address, and the 4037 addresses differ, the value from the environment is used and a 4038 warning is printed. 4039 4040o If neither SROM nor the environment contain a MAC address, an error 4041 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4042 a random, locally-assigned MAC is used. 4043 4044If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4045will be programmed into hardware as part of the initialization process. This 4046may be skipped by setting the appropriate 'ethmacskip' environment variable. 4047The naming convention is as follows: 4048"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4049 4050Image Formats: 4051============== 4052 4053U-Boot is capable of booting (and performing other auxiliary operations on) 4054images in two formats: 4055 4056New uImage format (FIT) 4057----------------------- 4058 4059Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4060to Flattened Device Tree). It allows the use of images with multiple 4061components (several kernels, ramdisks, etc.), with contents protected by 4062SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4063 4064 4065Old uImage format 4066----------------- 4067 4068Old image format is based on binary files which can be basically anything, 4069preceded by a special header; see the definitions in include/image.h for 4070details; basically, the header defines the following image properties: 4071 4072* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4073 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4074 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4075 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4076 INTEGRITY). 4077* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4078 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4079 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4080* Compression Type (uncompressed, gzip, bzip2) 4081* Load Address 4082* Entry Point 4083* Image Name 4084* Image Timestamp 4085 4086The header is marked by a special Magic Number, and both the header 4087and the data portions of the image are secured against corruption by 4088CRC32 checksums. 4089 4090 4091Linux Support: 4092============== 4093 4094Although U-Boot should support any OS or standalone application 4095easily, the main focus has always been on Linux during the design of 4096U-Boot. 4097 4098U-Boot includes many features that so far have been part of some 4099special "boot loader" code within the Linux kernel. Also, any 4100"initrd" images to be used are no longer part of one big Linux image; 4101instead, kernel and "initrd" are separate images. This implementation 4102serves several purposes: 4103 4104- the same features can be used for other OS or standalone 4105 applications (for instance: using compressed images to reduce the 4106 Flash memory footprint) 4107 4108- it becomes much easier to port new Linux kernel versions because 4109 lots of low-level, hardware dependent stuff are done by U-Boot 4110 4111- the same Linux kernel image can now be used with different "initrd" 4112 images; of course this also means that different kernel images can 4113 be run with the same "initrd". This makes testing easier (you don't 4114 have to build a new "zImage.initrd" Linux image when you just 4115 change a file in your "initrd"). Also, a field-upgrade of the 4116 software is easier now. 4117 4118 4119Linux HOWTO: 4120============ 4121 4122Porting Linux to U-Boot based systems: 4123--------------------------------------- 4124 4125U-Boot cannot save you from doing all the necessary modifications to 4126configure the Linux device drivers for use with your target hardware 4127(no, we don't intend to provide a full virtual machine interface to 4128Linux :-). 4129 4130But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4131 4132Just make sure your machine specific header file (for instance 4133include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4134Information structure as we define in include/asm-<arch>/u-boot.h, 4135and make sure that your definition of IMAP_ADDR uses the same value 4136as your U-Boot configuration in CONFIG_SYS_IMMR. 4137 4138Note that U-Boot now has a driver model, a unified model for drivers. 4139If you are adding a new driver, plumb it into driver model. If there 4140is no uclass available, you are encouraged to create one. See 4141doc/driver-model. 4142 4143 4144Configuring the Linux kernel: 4145----------------------------- 4146 4147No specific requirements for U-Boot. Make sure you have some root 4148device (initial ramdisk, NFS) for your target system. 4149 4150 4151Building a Linux Image: 4152----------------------- 4153 4154With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4155not used. If you use recent kernel source, a new build target 4156"uImage" will exist which automatically builds an image usable by 4157U-Boot. Most older kernels also have support for a "pImage" target, 4158which was introduced for our predecessor project PPCBoot and uses a 4159100% compatible format. 4160 4161Example: 4162 4163 make TQM850L_defconfig 4164 make oldconfig 4165 make dep 4166 make uImage 4167 4168The "uImage" build target uses a special tool (in 'tools/mkimage') to 4169encapsulate a compressed Linux kernel image with header information, 4170CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4171 4172* build a standard "vmlinux" kernel image (in ELF binary format): 4173 4174* convert the kernel into a raw binary image: 4175 4176 ${CROSS_COMPILE}-objcopy -O binary \ 4177 -R .note -R .comment \ 4178 -S vmlinux linux.bin 4179 4180* compress the binary image: 4181 4182 gzip -9 linux.bin 4183 4184* package compressed binary image for U-Boot: 4185 4186 mkimage -A ppc -O linux -T kernel -C gzip \ 4187 -a 0 -e 0 -n "Linux Kernel Image" \ 4188 -d linux.bin.gz uImage 4189 4190 4191The "mkimage" tool can also be used to create ramdisk images for use 4192with U-Boot, either separated from the Linux kernel image, or 4193combined into one file. "mkimage" encapsulates the images with a 64 4194byte header containing information about target architecture, 4195operating system, image type, compression method, entry points, time 4196stamp, CRC32 checksums, etc. 4197 4198"mkimage" can be called in two ways: to verify existing images and 4199print the header information, or to build new images. 4200 4201In the first form (with "-l" option) mkimage lists the information 4202contained in the header of an existing U-Boot image; this includes 4203checksum verification: 4204 4205 tools/mkimage -l image 4206 -l ==> list image header information 4207 4208The second form (with "-d" option) is used to build a U-Boot image 4209from a "data file" which is used as image payload: 4210 4211 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4212 -n name -d data_file image 4213 -A ==> set architecture to 'arch' 4214 -O ==> set operating system to 'os' 4215 -T ==> set image type to 'type' 4216 -C ==> set compression type 'comp' 4217 -a ==> set load address to 'addr' (hex) 4218 -e ==> set entry point to 'ep' (hex) 4219 -n ==> set image name to 'name' 4220 -d ==> use image data from 'datafile' 4221 4222Right now, all Linux kernels for PowerPC systems use the same load 4223address (0x00000000), but the entry point address depends on the 4224kernel version: 4225 4226- 2.2.x kernels have the entry point at 0x0000000C, 4227- 2.3.x and later kernels have the entry point at 0x00000000. 4228 4229So a typical call to build a U-Boot image would read: 4230 4231 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4232 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4233 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4234 > examples/uImage.TQM850L 4235 Image Name: 2.4.4 kernel for TQM850L 4236 Created: Wed Jul 19 02:34:59 2000 4237 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4238 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4239 Load Address: 0x00000000 4240 Entry Point: 0x00000000 4241 4242To verify the contents of the image (or check for corruption): 4243 4244 -> tools/mkimage -l examples/uImage.TQM850L 4245 Image Name: 2.4.4 kernel for TQM850L 4246 Created: Wed Jul 19 02:34:59 2000 4247 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4248 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4249 Load Address: 0x00000000 4250 Entry Point: 0x00000000 4251 4252NOTE: for embedded systems where boot time is critical you can trade 4253speed for memory and install an UNCOMPRESSED image instead: this 4254needs more space in Flash, but boots much faster since it does not 4255need to be uncompressed: 4256 4257 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4258 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4259 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4260 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4261 > examples/uImage.TQM850L-uncompressed 4262 Image Name: 2.4.4 kernel for TQM850L 4263 Created: Wed Jul 19 02:34:59 2000 4264 Image Type: PowerPC Linux Kernel Image (uncompressed) 4265 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4266 Load Address: 0x00000000 4267 Entry Point: 0x00000000 4268 4269 4270Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4271when your kernel is intended to use an initial ramdisk: 4272 4273 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4274 > -A ppc -O linux -T ramdisk -C gzip \ 4275 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4276 Image Name: Simple Ramdisk Image 4277 Created: Wed Jan 12 14:01:50 2000 4278 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4279 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4280 Load Address: 0x00000000 4281 Entry Point: 0x00000000 4282 4283The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4284option performs the converse operation of the mkimage's second form (the "-d" 4285option). Given an image built by mkimage, the dumpimage extracts a "data file" 4286from the image: 4287 4288 tools/dumpimage -i image -T type -p position data_file 4289 -i ==> extract from the 'image' a specific 'data_file' 4290 -T ==> set image type to 'type' 4291 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4292 4293 4294Installing a Linux Image: 4295------------------------- 4296 4297To downloading a U-Boot image over the serial (console) interface, 4298you must convert the image to S-Record format: 4299 4300 objcopy -I binary -O srec examples/image examples/image.srec 4301 4302The 'objcopy' does not understand the information in the U-Boot 4303image header, so the resulting S-Record file will be relative to 4304address 0x00000000. To load it to a given address, you need to 4305specify the target address as 'offset' parameter with the 'loads' 4306command. 4307 4308Example: install the image to address 0x40100000 (which on the 4309TQM8xxL is in the first Flash bank): 4310 4311 => erase 40100000 401FFFFF 4312 4313 .......... done 4314 Erased 8 sectors 4315 4316 => loads 40100000 4317 ## Ready for S-Record download ... 4318 ~>examples/image.srec 4319 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4320 ... 4321 15989 15990 15991 15992 4322 [file transfer complete] 4323 [connected] 4324 ## Start Addr = 0x00000000 4325 4326 4327You can check the success of the download using the 'iminfo' command; 4328this includes a checksum verification so you can be sure no data 4329corruption happened: 4330 4331 => imi 40100000 4332 4333 ## Checking Image at 40100000 ... 4334 Image Name: 2.2.13 for initrd on TQM850L 4335 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4336 Data Size: 335725 Bytes = 327 kB = 0 MB 4337 Load Address: 00000000 4338 Entry Point: 0000000c 4339 Verifying Checksum ... OK 4340 4341 4342Boot Linux: 4343----------- 4344 4345The "bootm" command is used to boot an application that is stored in 4346memory (RAM or Flash). In case of a Linux kernel image, the contents 4347of the "bootargs" environment variable is passed to the kernel as 4348parameters. You can check and modify this variable using the 4349"printenv" and "setenv" commands: 4350 4351 4352 => printenv bootargs 4353 bootargs=root=/dev/ram 4354 4355 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4356 4357 => printenv bootargs 4358 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4359 4360 => bootm 40020000 4361 ## Booting Linux kernel at 40020000 ... 4362 Image Name: 2.2.13 for NFS on TQM850L 4363 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4364 Data Size: 381681 Bytes = 372 kB = 0 MB 4365 Load Address: 00000000 4366 Entry Point: 0000000c 4367 Verifying Checksum ... OK 4368 Uncompressing Kernel Image ... OK 4369 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 4370 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4371 time_init: decrementer frequency = 187500000/60 4372 Calibrating delay loop... 49.77 BogoMIPS 4373 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4374 ... 4375 4376If you want to boot a Linux kernel with initial RAM disk, you pass 4377the memory addresses of both the kernel and the initrd image (PPBCOOT 4378format!) to the "bootm" command: 4379 4380 => imi 40100000 40200000 4381 4382 ## Checking Image at 40100000 ... 4383 Image Name: 2.2.13 for initrd on TQM850L 4384 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4385 Data Size: 335725 Bytes = 327 kB = 0 MB 4386 Load Address: 00000000 4387 Entry Point: 0000000c 4388 Verifying Checksum ... OK 4389 4390 ## Checking Image at 40200000 ... 4391 Image Name: Simple Ramdisk Image 4392 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4393 Data Size: 566530 Bytes = 553 kB = 0 MB 4394 Load Address: 00000000 4395 Entry Point: 00000000 4396 Verifying Checksum ... OK 4397 4398 => bootm 40100000 40200000 4399 ## Booting Linux kernel at 40100000 ... 4400 Image Name: 2.2.13 for initrd on TQM850L 4401 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4402 Data Size: 335725 Bytes = 327 kB = 0 MB 4403 Load Address: 00000000 4404 Entry Point: 0000000c 4405 Verifying Checksum ... OK 4406 Uncompressing Kernel Image ... OK 4407 ## Loading RAMDisk Image at 40200000 ... 4408 Image Name: Simple Ramdisk Image 4409 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4410 Data Size: 566530 Bytes = 553 kB = 0 MB 4411 Load Address: 00000000 4412 Entry Point: 00000000 4413 Verifying Checksum ... OK 4414 Loading Ramdisk ... OK 4415 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 4416 Boot arguments: root=/dev/ram 4417 time_init: decrementer frequency = 187500000/60 4418 Calibrating delay loop... 49.77 BogoMIPS 4419 ... 4420 RAMDISK: Compressed image found at block 0 4421 VFS: Mounted root (ext2 filesystem). 4422 4423 bash# 4424 4425Boot Linux and pass a flat device tree: 4426----------- 4427 4428First, U-Boot must be compiled with the appropriate defines. See the section 4429titled "Linux Kernel Interface" above for a more in depth explanation. The 4430following is an example of how to start a kernel and pass an updated 4431flat device tree: 4432 4433=> print oftaddr 4434oftaddr=0x300000 4435=> print oft 4436oft=oftrees/mpc8540ads.dtb 4437=> tftp $oftaddr $oft 4438Speed: 1000, full duplex 4439Using TSEC0 device 4440TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4441Filename 'oftrees/mpc8540ads.dtb'. 4442Load address: 0x300000 4443Loading: # 4444done 4445Bytes transferred = 4106 (100a hex) 4446=> tftp $loadaddr $bootfile 4447Speed: 1000, full duplex 4448Using TSEC0 device 4449TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4450Filename 'uImage'. 4451Load address: 0x200000 4452Loading:############ 4453done 4454Bytes transferred = 1029407 (fb51f hex) 4455=> print loadaddr 4456loadaddr=200000 4457=> print oftaddr 4458oftaddr=0x300000 4459=> bootm $loadaddr - $oftaddr 4460## Booting image at 00200000 ... 4461 Image Name: Linux-2.6.17-dirty 4462 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4463 Data Size: 1029343 Bytes = 1005.2 kB 4464 Load Address: 00000000 4465 Entry Point: 00000000 4466 Verifying Checksum ... OK 4467 Uncompressing Kernel Image ... OK 4468Booting using flat device tree at 0x300000 4469Using MPC85xx ADS machine description 4470Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4471[snip] 4472 4473 4474More About U-Boot Image Types: 4475------------------------------ 4476 4477U-Boot supports the following image types: 4478 4479 "Standalone Programs" are directly runnable in the environment 4480 provided by U-Boot; it is expected that (if they behave 4481 well) you can continue to work in U-Boot after return from 4482 the Standalone Program. 4483 "OS Kernel Images" are usually images of some Embedded OS which 4484 will take over control completely. Usually these programs 4485 will install their own set of exception handlers, device 4486 drivers, set up the MMU, etc. - this means, that you cannot 4487 expect to re-enter U-Boot except by resetting the CPU. 4488 "RAMDisk Images" are more or less just data blocks, and their 4489 parameters (address, size) are passed to an OS kernel that is 4490 being started. 4491 "Multi-File Images" contain several images, typically an OS 4492 (Linux) kernel image and one or more data images like 4493 RAMDisks. This construct is useful for instance when you want 4494 to boot over the network using BOOTP etc., where the boot 4495 server provides just a single image file, but you want to get 4496 for instance an OS kernel and a RAMDisk image. 4497 4498 "Multi-File Images" start with a list of image sizes, each 4499 image size (in bytes) specified by an "uint32_t" in network 4500 byte order. This list is terminated by an "(uint32_t)0". 4501 Immediately after the terminating 0 follow the images, one by 4502 one, all aligned on "uint32_t" boundaries (size rounded up to 4503 a multiple of 4 bytes). 4504 4505 "Firmware Images" are binary images containing firmware (like 4506 U-Boot or FPGA images) which usually will be programmed to 4507 flash memory. 4508 4509 "Script files" are command sequences that will be executed by 4510 U-Boot's command interpreter; this feature is especially 4511 useful when you configure U-Boot to use a real shell (hush) 4512 as command interpreter. 4513 4514Booting the Linux zImage: 4515------------------------- 4516 4517On some platforms, it's possible to boot Linux zImage. This is done 4518using the "bootz" command. The syntax of "bootz" command is the same 4519as the syntax of "bootm" command. 4520 4521Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4522kernel with raw initrd images. The syntax is slightly different, the 4523address of the initrd must be augmented by it's size, in the following 4524format: "<initrd addres>:<initrd size>". 4525 4526 4527Standalone HOWTO: 4528================= 4529 4530One of the features of U-Boot is that you can dynamically load and 4531run "standalone" applications, which can use some resources of 4532U-Boot like console I/O functions or interrupt services. 4533 4534Two simple examples are included with the sources: 4535 4536"Hello World" Demo: 4537------------------- 4538 4539'examples/hello_world.c' contains a small "Hello World" Demo 4540application; it is automatically compiled when you build U-Boot. 4541It's configured to run at address 0x00040004, so you can play with it 4542like that: 4543 4544 => loads 4545 ## Ready for S-Record download ... 4546 ~>examples/hello_world.srec 4547 1 2 3 4 5 6 7 8 9 10 11 ... 4548 [file transfer complete] 4549 [connected] 4550 ## Start Addr = 0x00040004 4551 4552 => go 40004 Hello World! This is a test. 4553 ## Starting application at 0x00040004 ... 4554 Hello World 4555 argc = 7 4556 argv[0] = "40004" 4557 argv[1] = "Hello" 4558 argv[2] = "World!" 4559 argv[3] = "This" 4560 argv[4] = "is" 4561 argv[5] = "a" 4562 argv[6] = "test." 4563 argv[7] = "<NULL>" 4564 Hit any key to exit ... 4565 4566 ## Application terminated, rc = 0x0 4567 4568Another example, which demonstrates how to register a CPM interrupt 4569handler with the U-Boot code, can be found in 'examples/timer.c'. 4570Here, a CPM timer is set up to generate an interrupt every second. 4571The interrupt service routine is trivial, just printing a '.' 4572character, but this is just a demo program. The application can be 4573controlled by the following keys: 4574 4575 ? - print current values og the CPM Timer registers 4576 b - enable interrupts and start timer 4577 e - stop timer and disable interrupts 4578 q - quit application 4579 4580 => loads 4581 ## Ready for S-Record download ... 4582 ~>examples/timer.srec 4583 1 2 3 4 5 6 7 8 9 10 11 ... 4584 [file transfer complete] 4585 [connected] 4586 ## Start Addr = 0x00040004 4587 4588 => go 40004 4589 ## Starting application at 0x00040004 ... 4590 TIMERS=0xfff00980 4591 Using timer 1 4592 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4593 4594Hit 'b': 4595 [q, b, e, ?] Set interval 1000000 us 4596 Enabling timer 4597Hit '?': 4598 [q, b, e, ?] ........ 4599 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4600Hit '?': 4601 [q, b, e, ?] . 4602 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4603Hit '?': 4604 [q, b, e, ?] . 4605 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4606Hit '?': 4607 [q, b, e, ?] . 4608 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4609Hit 'e': 4610 [q, b, e, ?] ...Stopping timer 4611Hit 'q': 4612 [q, b, e, ?] ## Application terminated, rc = 0x0 4613 4614 4615Minicom warning: 4616================ 4617 4618Over time, many people have reported problems when trying to use the 4619"minicom" terminal emulation program for serial download. I (wd) 4620consider minicom to be broken, and recommend not to use it. Under 4621Unix, I recommend to use C-Kermit for general purpose use (and 4622especially for kermit binary protocol download ("loadb" command), and 4623use "cu" for S-Record download ("loads" command). See 4624http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4625for help with kermit. 4626 4627 4628Nevertheless, if you absolutely want to use it try adding this 4629configuration to your "File transfer protocols" section: 4630 4631 Name Program Name U/D FullScr IO-Red. Multi 4632 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4633 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4634 4635 4636NetBSD Notes: 4637============= 4638 4639Starting at version 0.9.2, U-Boot supports NetBSD both as host 4640(build U-Boot) and target system (boots NetBSD/mpc8xx). 4641 4642Building requires a cross environment; it is known to work on 4643NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4644need gmake since the Makefiles are not compatible with BSD make). 4645Note that the cross-powerpc package does not install include files; 4646attempting to build U-Boot will fail because <machine/ansi.h> is 4647missing. This file has to be installed and patched manually: 4648 4649 # cd /usr/pkg/cross/powerpc-netbsd/include 4650 # mkdir powerpc 4651 # ln -s powerpc machine 4652 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4653 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4654 4655Native builds *don't* work due to incompatibilities between native 4656and U-Boot include files. 4657 4658Booting assumes that (the first part of) the image booted is a 4659stage-2 loader which in turn loads and then invokes the kernel 4660proper. Loader sources will eventually appear in the NetBSD source 4661tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4662meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4663 4664 4665Implementation Internals: 4666========================= 4667 4668The following is not intended to be a complete description of every 4669implementation detail. However, it should help to understand the 4670inner workings of U-Boot and make it easier to port it to custom 4671hardware. 4672 4673 4674Initial Stack, Global Data: 4675--------------------------- 4676 4677The implementation of U-Boot is complicated by the fact that U-Boot 4678starts running out of ROM (flash memory), usually without access to 4679system RAM (because the memory controller is not initialized yet). 4680This means that we don't have writable Data or BSS segments, and BSS 4681is not initialized as zero. To be able to get a C environment working 4682at all, we have to allocate at least a minimal stack. Implementation 4683options for this are defined and restricted by the CPU used: Some CPU 4684models provide on-chip memory (like the IMMR area on MPC8xx and 4685MPC826x processors), on others (parts of) the data cache can be 4686locked as (mis-) used as memory, etc. 4687 4688 Chris Hallinan posted a good summary of these issues to the 4689 U-Boot mailing list: 4690 4691 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4692 From: "Chris Hallinan" <clh@net1plus.com> 4693 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4694 ... 4695 4696 Correct me if I'm wrong, folks, but the way I understand it 4697 is this: Using DCACHE as initial RAM for Stack, etc, does not 4698 require any physical RAM backing up the cache. The cleverness 4699 is that the cache is being used as a temporary supply of 4700 necessary storage before the SDRAM controller is setup. It's 4701 beyond the scope of this list to explain the details, but you 4702 can see how this works by studying the cache architecture and 4703 operation in the architecture and processor-specific manuals. 4704 4705 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4706 is another option for the system designer to use as an 4707 initial stack/RAM area prior to SDRAM being available. Either 4708 option should work for you. Using CS 4 should be fine if your 4709 board designers haven't used it for something that would 4710 cause you grief during the initial boot! It is frequently not 4711 used. 4712 4713 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4714 with your processor/board/system design. The default value 4715 you will find in any recent u-boot distribution in 4716 walnut.h should work for you. I'd set it to a value larger 4717 than your SDRAM module. If you have a 64MB SDRAM module, set 4718 it above 400_0000. Just make sure your board has no resources 4719 that are supposed to respond to that address! That code in 4720 start.S has been around a while and should work as is when 4721 you get the config right. 4722 4723 -Chris Hallinan 4724 DS4.COM, Inc. 4725 4726It is essential to remember this, since it has some impact on the C 4727code for the initialization procedures: 4728 4729* Initialized global data (data segment) is read-only. Do not attempt 4730 to write it. 4731 4732* Do not use any uninitialized global data (or implicitly initialized 4733 as zero data - BSS segment) at all - this is undefined, initiali- 4734 zation is performed later (when relocating to RAM). 4735 4736* Stack space is very limited. Avoid big data buffers or things like 4737 that. 4738 4739Having only the stack as writable memory limits means we cannot use 4740normal global data to share information between the code. But it 4741turned out that the implementation of U-Boot can be greatly 4742simplified by making a global data structure (gd_t) available to all 4743functions. We could pass a pointer to this data as argument to _all_ 4744functions, but this would bloat the code. Instead we use a feature of 4745the GCC compiler (Global Register Variables) to share the data: we 4746place a pointer (gd) to the global data into a register which we 4747reserve for this purpose. 4748 4749When choosing a register for such a purpose we are restricted by the 4750relevant (E)ABI specifications for the current architecture, and by 4751GCC's implementation. 4752 4753For PowerPC, the following registers have specific use: 4754 R1: stack pointer 4755 R2: reserved for system use 4756 R3-R4: parameter passing and return values 4757 R5-R10: parameter passing 4758 R13: small data area pointer 4759 R30: GOT pointer 4760 R31: frame pointer 4761 4762 (U-Boot also uses R12 as internal GOT pointer. r12 4763 is a volatile register so r12 needs to be reset when 4764 going back and forth between asm and C) 4765 4766 ==> U-Boot will use R2 to hold a pointer to the global data 4767 4768 Note: on PPC, we could use a static initializer (since the 4769 address of the global data structure is known at compile time), 4770 but it turned out that reserving a register results in somewhat 4771 smaller code - although the code savings are not that big (on 4772 average for all boards 752 bytes for the whole U-Boot image, 4773 624 text + 127 data). 4774 4775On ARM, the following registers are used: 4776 4777 R0: function argument word/integer result 4778 R1-R3: function argument word 4779 R9: platform specific 4780 R10: stack limit (used only if stack checking is enabled) 4781 R11: argument (frame) pointer 4782 R12: temporary workspace 4783 R13: stack pointer 4784 R14: link register 4785 R15: program counter 4786 4787 ==> U-Boot will use R9 to hold a pointer to the global data 4788 4789 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4790 4791On Nios II, the ABI is documented here: 4792 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4793 4794 ==> U-Boot will use gp to hold a pointer to the global data 4795 4796 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4797 to access small data sections, so gp is free. 4798 4799On NDS32, the following registers are used: 4800 4801 R0-R1: argument/return 4802 R2-R5: argument 4803 R15: temporary register for assembler 4804 R16: trampoline register 4805 R28: frame pointer (FP) 4806 R29: global pointer (GP) 4807 R30: link register (LP) 4808 R31: stack pointer (SP) 4809 PC: program counter (PC) 4810 4811 ==> U-Boot will use R10 to hold a pointer to the global data 4812 4813NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4814or current versions of GCC may "optimize" the code too much. 4815 4816On RISC-V, the following registers are used: 4817 4818 x0: hard-wired zero (zero) 4819 x1: return address (ra) 4820 x2: stack pointer (sp) 4821 x3: global pointer (gp) 4822 x4: thread pointer (tp) 4823 x5: link register (t0) 4824 x8: frame pointer (fp) 4825 x10-x11: arguments/return values (a0-1) 4826 x12-x17: arguments (a2-7) 4827 x28-31: temporaries (t3-6) 4828 pc: program counter (pc) 4829 4830 ==> U-Boot will use gp to hold a pointer to the global data 4831 4832Memory Management: 4833------------------ 4834 4835U-Boot runs in system state and uses physical addresses, i.e. the 4836MMU is not used either for address mapping nor for memory protection. 4837 4838The available memory is mapped to fixed addresses using the memory 4839controller. In this process, a contiguous block is formed for each 4840memory type (Flash, SDRAM, SRAM), even when it consists of several 4841physical memory banks. 4842 4843U-Boot is installed in the first 128 kB of the first Flash bank (on 4844TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4845booting and sizing and initializing DRAM, the code relocates itself 4846to the upper end of DRAM. Immediately below the U-Boot code some 4847memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4848configuration setting]. Below that, a structure with global Board 4849Info data is placed, followed by the stack (growing downward). 4850 4851Additionally, some exception handler code is copied to the low 8 kB 4852of DRAM (0x00000000 ... 0x00001FFF). 4853 4854So a typical memory configuration with 16 MB of DRAM could look like 4855this: 4856 4857 0x0000 0000 Exception Vector code 4858 : 4859 0x0000 1FFF 4860 0x0000 2000 Free for Application Use 4861 : 4862 : 4863 4864 : 4865 : 4866 0x00FB FF20 Monitor Stack (Growing downward) 4867 0x00FB FFAC Board Info Data and permanent copy of global data 4868 0x00FC 0000 Malloc Arena 4869 : 4870 0x00FD FFFF 4871 0x00FE 0000 RAM Copy of Monitor Code 4872 ... eventually: LCD or video framebuffer 4873 ... eventually: pRAM (Protected RAM - unchanged by reset) 4874 0x00FF FFFF [End of RAM] 4875 4876 4877System Initialization: 4878---------------------- 4879 4880In the reset configuration, U-Boot starts at the reset entry point 4881(on most PowerPC systems at address 0x00000100). Because of the reset 4882configuration for CS0# this is a mirror of the on board Flash memory. 4883To be able to re-map memory U-Boot then jumps to its link address. 4884To be able to implement the initialization code in C, a (small!) 4885initial stack is set up in the internal Dual Ported RAM (in case CPUs 4886which provide such a feature like), or in a locked part of the data 4887cache. After that, U-Boot initializes the CPU core, the caches and 4888the SIU. 4889 4890Next, all (potentially) available memory banks are mapped using a 4891preliminary mapping. For example, we put them on 512 MB boundaries 4892(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4893on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4894programmed for SDRAM access. Using the temporary configuration, a 4895simple memory test is run that determines the size of the SDRAM 4896banks. 4897 4898When there is more than one SDRAM bank, and the banks are of 4899different size, the largest is mapped first. For equal size, the first 4900bank (CS2#) is mapped first. The first mapping is always for address 49010x00000000, with any additional banks following immediately to create 4902contiguous memory starting from 0. 4903 4904Then, the monitor installs itself at the upper end of the SDRAM area 4905and allocates memory for use by malloc() and for the global Board 4906Info data; also, the exception vector code is copied to the low RAM 4907pages, and the final stack is set up. 4908 4909Only after this relocation will you have a "normal" C environment; 4910until that you are restricted in several ways, mostly because you are 4911running from ROM, and because the code will have to be relocated to a 4912new address in RAM. 4913 4914 4915U-Boot Porting Guide: 4916---------------------- 4917 4918[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4919list, October 2002] 4920 4921 4922int main(int argc, char *argv[]) 4923{ 4924 sighandler_t no_more_time; 4925 4926 signal(SIGALRM, no_more_time); 4927 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4928 4929 if (available_money > available_manpower) { 4930 Pay consultant to port U-Boot; 4931 return 0; 4932 } 4933 4934 Download latest U-Boot source; 4935 4936 Subscribe to u-boot mailing list; 4937 4938 if (clueless) 4939 email("Hi, I am new to U-Boot, how do I get started?"); 4940 4941 while (learning) { 4942 Read the README file in the top level directory; 4943 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4944 Read applicable doc/*.README; 4945 Read the source, Luke; 4946 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4947 } 4948 4949 if (available_money > toLocalCurrency ($2500)) 4950 Buy a BDI3000; 4951 else 4952 Add a lot of aggravation and time; 4953 4954 if (a similar board exists) { /* hopefully... */ 4955 cp -a board/<similar> board/<myboard> 4956 cp include/configs/<similar>.h include/configs/<myboard>.h 4957 } else { 4958 Create your own board support subdirectory; 4959 Create your own board include/configs/<myboard>.h file; 4960 } 4961 Edit new board/<myboard> files 4962 Edit new include/configs/<myboard>.h 4963 4964 while (!accepted) { 4965 while (!running) { 4966 do { 4967 Add / modify source code; 4968 } until (compiles); 4969 Debug; 4970 if (clueless) 4971 email("Hi, I am having problems..."); 4972 } 4973 Send patch file to the U-Boot email list; 4974 if (reasonable critiques) 4975 Incorporate improvements from email list code review; 4976 else 4977 Defend code as written; 4978 } 4979 4980 return 0; 4981} 4982 4983void no_more_time (int sig) 4984{ 4985 hire_a_guru(); 4986} 4987 4988 4989Coding Standards: 4990----------------- 4991 4992All contributions to U-Boot should conform to the Linux kernel 4993coding style; see the kernel coding style guide at 4994https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 4995script "scripts/Lindent" in your Linux kernel source directory. 4996 4997Source files originating from a different project (for example the 4998MTD subsystem) are generally exempt from these guidelines and are not 4999reformatted to ease subsequent migration to newer versions of those 5000sources. 5001 5002Please note that U-Boot is implemented in C (and to some small parts in 5003Assembler); no C++ is used, so please do not use C++ style comments (//) 5004in your code. 5005 5006Please also stick to the following formatting rules: 5007- remove any trailing white space 5008- use TAB characters for indentation and vertical alignment, not spaces 5009- make sure NOT to use DOS '\r\n' line feeds 5010- do not add more than 2 consecutive empty lines to source files 5011- do not add trailing empty lines to source files 5012 5013Submissions which do not conform to the standards may be returned 5014with a request to reformat the changes. 5015 5016 5017Submitting Patches: 5018------------------- 5019 5020Since the number of patches for U-Boot is growing, we need to 5021establish some rules. Submissions which do not conform to these rules 5022may be rejected, even when they contain important and valuable stuff. 5023 5024Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5025 5026Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5027see https://lists.denx.de/listinfo/u-boot 5028 5029When you send a patch, please include the following information with 5030it: 5031 5032* For bug fixes: a description of the bug and how your patch fixes 5033 this bug. Please try to include a way of demonstrating that the 5034 patch actually fixes something. 5035 5036* For new features: a description of the feature and your 5037 implementation. 5038 5039* A CHANGELOG entry as plaintext (separate from the patch) 5040 5041* For major contributions, add a MAINTAINERS file with your 5042 information and associated file and directory references. 5043 5044* When you add support for a new board, don't forget to add a 5045 maintainer e-mail address to the boards.cfg file, too. 5046 5047* If your patch adds new configuration options, don't forget to 5048 document these in the README file. 5049 5050* The patch itself. If you are using git (which is *strongly* 5051 recommended) you can easily generate the patch using the 5052 "git format-patch". If you then use "git send-email" to send it to 5053 the U-Boot mailing list, you will avoid most of the common problems 5054 with some other mail clients. 5055 5056 If you cannot use git, use "diff -purN OLD NEW". If your version of 5057 diff does not support these options, then get the latest version of 5058 GNU diff. 5059 5060 The current directory when running this command shall be the parent 5061 directory of the U-Boot source tree (i. e. please make sure that 5062 your patch includes sufficient directory information for the 5063 affected files). 5064 5065 We prefer patches as plain text. MIME attachments are discouraged, 5066 and compressed attachments must not be used. 5067 5068* If one logical set of modifications affects or creates several 5069 files, all these changes shall be submitted in a SINGLE patch file. 5070 5071* Changesets that contain different, unrelated modifications shall be 5072 submitted as SEPARATE patches, one patch per changeset. 5073 5074 5075Notes: 5076 5077* Before sending the patch, run the buildman script on your patched 5078 source tree and make sure that no errors or warnings are reported 5079 for any of the boards. 5080 5081* Keep your modifications to the necessary minimum: A patch 5082 containing several unrelated changes or arbitrary reformats will be 5083 returned with a request to re-formatting / split it. 5084 5085* If you modify existing code, make sure that your new code does not 5086 add to the memory footprint of the code ;-) Small is beautiful! 5087 When adding new features, these should compile conditionally only 5088 (using #ifdef), and the resulting code with the new feature 5089 disabled must not need more memory than the old code without your 5090 modification. 5091 5092* Remember that there is a size limit of 100 kB per message on the 5093 u-boot mailing list. Bigger patches will be moderated. If they are 5094 reasonable and not too big, they will be acknowledged. But patches 5095 bigger than the size limit should be avoided. 5096