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- Bootcount: 717 CONFIG_BOOTCOUNT_ENV 718 If no softreset save registers are found on the hardware 719 "bootcount" is stored in the environment. To prevent a 720 saveenv on all reboots, the environment variable 721 "upgrade_available" is used. If "upgrade_available" is 722 0, "bootcount" is always 0, if "upgrade_available" is 723 1 "bootcount" is incremented in the environment. 724 So the Userspace Applikation must set the "upgrade_available" 725 and "bootcount" variable to 0, if a boot was successfully. 726 727- Pre-Boot Commands: 728 CONFIG_PREBOOT 729 730 When this option is #defined, the existence of the 731 environment variable "preboot" will be checked 732 immediately before starting the CONFIG_BOOTDELAY 733 countdown and/or running the auto-boot command resp. 734 entering interactive mode. 735 736 This feature is especially useful when "preboot" is 737 automatically generated or modified. For an example 738 see the LWMON board specific code: here "preboot" is 739 modified when the user holds down a certain 740 combination of keys on the (special) keyboard when 741 booting the systems 742 743- Serial Download Echo Mode: 744 CONFIG_LOADS_ECHO 745 If defined to 1, all characters received during a 746 serial download (using the "loads" command) are 747 echoed back. This might be needed by some terminal 748 emulations (like "cu"), but may as well just take 749 time on others. This setting #define's the initial 750 value of the "loads_echo" environment variable. 751 752- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 753 CONFIG_KGDB_BAUDRATE 754 Select one of the baudrates listed in 755 CONFIG_SYS_BAUDRATE_TABLE, see below. 756 757- Removal of commands 758 If no commands are needed to boot, you can disable 759 CONFIG_CMDLINE to remove them. In this case, the command line 760 will not be available, and when U-Boot wants to execute the 761 boot command (on start-up) it will call board_run_command() 762 instead. This can reduce image size significantly for very 763 simple boot procedures. 764 765- Regular expression support: 766 CONFIG_REGEX 767 If this variable is defined, U-Boot is linked against 768 the SLRE (Super Light Regular Expression) library, 769 which adds regex support to some commands, as for 770 example "env grep" and "setexpr". 771 772- Device tree: 773 CONFIG_OF_CONTROL 774 If this variable is defined, U-Boot will use a device tree 775 to configure its devices, instead of relying on statically 776 compiled #defines in the board file. This option is 777 experimental and only available on a few boards. The device 778 tree is available in the global data as gd->fdt_blob. 779 780 U-Boot needs to get its device tree from somewhere. This can 781 be done using one of the three options below: 782 783 CONFIG_OF_EMBED 784 If this variable is defined, U-Boot will embed a device tree 785 binary in its image. This device tree file should be in the 786 board directory and called <soc>-<board>.dts. The binary file 787 is then picked up in board_init_f() and made available through 788 the global data structure as gd->fdt_blob. 789 790 CONFIG_OF_SEPARATE 791 If this variable is defined, U-Boot will build a device tree 792 binary. It will be called u-boot.dtb. Architecture-specific 793 code will locate it at run-time. Generally this works by: 794 795 cat u-boot.bin u-boot.dtb >image.bin 796 797 and in fact, U-Boot does this for you, creating a file called 798 u-boot-dtb.bin which is useful in the common case. You can 799 still use the individual files if you need something more 800 exotic. 801 802 CONFIG_OF_BOARD 803 If this variable is defined, U-Boot will use the device tree 804 provided by the board at runtime instead of embedding one with 805 the image. Only boards defining board_fdt_blob_setup() support 806 this option (see include/fdtdec.h file). 807 808- Watchdog: 809 CONFIG_WATCHDOG 810 If this variable is defined, it enables watchdog 811 support for the SoC. There must be support in the SoC 812 specific code for a watchdog. For the 8xx 813 CPUs, the SIU Watchdog feature is enabled in the SYPCR 814 register. When supported for a specific SoC is 815 available, then no further board specific code should 816 be needed to use it. 817 818 CONFIG_HW_WATCHDOG 819 When using a watchdog circuitry external to the used 820 SoC, then define this variable and provide board 821 specific code for the "hw_watchdog_reset" function. 822 823 CONFIG_AT91_HW_WDT_TIMEOUT 824 specify the timeout in seconds. default 2 seconds. 825 826- U-Boot Version: 827 CONFIG_VERSION_VARIABLE 828 If this variable is defined, an environment variable 829 named "ver" is created by U-Boot showing the U-Boot 830 version as printed by the "version" command. 831 Any change to this variable will be reverted at the 832 next reset. 833 834- Real-Time Clock: 835 836 When CONFIG_CMD_DATE is selected, the type of the RTC 837 has to be selected, too. Define exactly one of the 838 following options: 839 840 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 841 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 842 CONFIG_RTC_MC146818 - use MC146818 RTC 843 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 844 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 845 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 846 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 847 CONFIG_RTC_DS164x - use Dallas DS164x RTC 848 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 849 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 850 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 851 CONFIG_SYS_RV3029_TCR - enable trickle charger on 852 RV3029 RTC. 853 854 Note that if the RTC uses I2C, then the I2C interface 855 must also be configured. See I2C Support, below. 856 857- GPIO Support: 858 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 859 860 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 861 chip-ngpio pairs that tell the PCA953X driver the number of 862 pins supported by a particular chip. 863 864 Note that if the GPIO device uses I2C, then the I2C interface 865 must also be configured. See I2C Support, below. 866 867- I/O tracing: 868 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 869 accesses and can checksum them or write a list of them out 870 to memory. See the 'iotrace' command for details. This is 871 useful for testing device drivers since it can confirm that 872 the driver behaves the same way before and after a code 873 change. Currently this is supported on sandbox and arm. To 874 add support for your architecture, add '#include <iotrace.h>' 875 to the bottom of arch/<arch>/include/asm/io.h and test. 876 877 Example output from the 'iotrace stats' command is below. 878 Note that if the trace buffer is exhausted, the checksum will 879 still continue to operate. 880 881 iotrace is enabled 882 Start: 10000000 (buffer start address) 883 Size: 00010000 (buffer size) 884 Offset: 00000120 (current buffer offset) 885 Output: 10000120 (start + offset) 886 Count: 00000018 (number of trace records) 887 CRC32: 9526fb66 (CRC32 of all trace records) 888 889- Timestamp Support: 890 891 When CONFIG_TIMESTAMP is selected, the timestamp 892 (date and time) of an image is printed by image 893 commands like bootm or iminfo. This option is 894 automatically enabled when you select CONFIG_CMD_DATE . 895 896- Partition Labels (disklabels) Supported: 897 Zero or more of the following: 898 CONFIG_MAC_PARTITION Apple's MacOS partition table. 899 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 900 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 901 bootloader. Note 2TB partition limit; see 902 disk/part_efi.c 903 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 904 905 If IDE or SCSI support is enabled (CONFIG_IDE or 906 CONFIG_SCSI) you must configure support for at 907 least one non-MTD partition type as well. 908 909- IDE Reset method: 910 CONFIG_IDE_RESET_ROUTINE - this is defined in several 911 board configurations files but used nowhere! 912 913 CONFIG_IDE_RESET - is this is defined, IDE Reset will 914 be performed by calling the function 915 ide_set_reset(int reset) 916 which has to be defined in a board specific file 917 918- ATAPI Support: 919 CONFIG_ATAPI 920 921 Set this to enable ATAPI support. 922 923- LBA48 Support 924 CONFIG_LBA48 925 926 Set this to enable support for disks larger than 137GB 927 Also look at CONFIG_SYS_64BIT_LBA. 928 Whithout these , LBA48 support uses 32bit variables and will 'only' 929 support disks up to 2.1TB. 930 931 CONFIG_SYS_64BIT_LBA: 932 When enabled, makes the IDE subsystem use 64bit sector addresses. 933 Default is 32bit. 934 935- SCSI Support: 936 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 937 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 938 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 939 maximum numbers of LUNs, SCSI ID's and target 940 devices. 941 942 The environment variable 'scsidevs' is set to the number of 943 SCSI devices found during the last scan. 944 945- NETWORK Support (PCI): 946 CONFIG_E1000 947 Support for Intel 8254x/8257x gigabit chips. 948 949 CONFIG_E1000_SPI 950 Utility code for direct access to the SPI bus on Intel 8257x. 951 This does not do anything useful unless you set at least one 952 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 953 954 CONFIG_E1000_SPI_GENERIC 955 Allow generic access to the SPI bus on the Intel 8257x, for 956 example with the "sspi" command. 957 958 CONFIG_EEPRO100 959 Support for Intel 82557/82559/82559ER chips. 960 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 961 write routine for first time initialisation. 962 963 CONFIG_TULIP 964 Support for Digital 2114x chips. 965 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 966 modem chip initialisation (KS8761/QS6611). 967 968 CONFIG_NATSEMI 969 Support for National dp83815 chips. 970 971 CONFIG_NS8382X 972 Support for National dp8382[01] gigabit chips. 973 974- NETWORK Support (other): 975 976 CONFIG_DRIVER_AT91EMAC 977 Support for AT91RM9200 EMAC. 978 979 CONFIG_RMII 980 Define this to use reduced MII inteface 981 982 CONFIG_DRIVER_AT91EMAC_QUIET 983 If this defined, the driver is quiet. 984 The driver doen't show link status messages. 985 986 CONFIG_CALXEDA_XGMAC 987 Support for the Calxeda XGMAC device 988 989 CONFIG_LAN91C96 990 Support for SMSC's LAN91C96 chips. 991 992 CONFIG_LAN91C96_USE_32_BIT 993 Define this to enable 32 bit addressing 994 995 CONFIG_SMC91111 996 Support for SMSC's LAN91C111 chip 997 998 CONFIG_SMC91111_BASE 999 Define this to hold the physical address 1000 of the device (I/O space) 1001 1002 CONFIG_SMC_USE_32_BIT 1003 Define this if data bus is 32 bits 1004 1005 CONFIG_SMC_USE_IOFUNCS 1006 Define this to use i/o functions instead of macros 1007 (some hardware wont work with macros) 1008 1009 CONFIG_DRIVER_TI_EMAC 1010 Support for davinci emac 1011 1012 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1013 Define this if you have more then 3 PHYs. 1014 1015 CONFIG_FTGMAC100 1016 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1017 1018 CONFIG_FTGMAC100_EGIGA 1019 Define this to use GE link update with gigabit PHY. 1020 Define this if FTGMAC100 is connected to gigabit PHY. 1021 If your system has 10/100 PHY only, it might not occur 1022 wrong behavior. Because PHY usually return timeout or 1023 useless data when polling gigabit status and gigabit 1024 control registers. This behavior won't affect the 1025 correctnessof 10/100 link speed update. 1026 1027 CONFIG_SH_ETHER 1028 Support for Renesas on-chip Ethernet controller 1029 1030 CONFIG_SH_ETHER_USE_PORT 1031 Define the number of ports to be used 1032 1033 CONFIG_SH_ETHER_PHY_ADDR 1034 Define the ETH PHY's address 1035 1036 CONFIG_SH_ETHER_CACHE_WRITEBACK 1037 If this option is set, the driver enables cache flush. 1038 1039- PWM Support: 1040 CONFIG_PWM_IMX 1041 Support for PWM module on the imx6. 1042 1043- TPM Support: 1044 CONFIG_TPM 1045 Support TPM devices. 1046 1047 CONFIG_TPM_TIS_INFINEON 1048 Support for Infineon i2c bus TPM devices. Only one device 1049 per system is supported at this time. 1050 1051 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1052 Define the burst count bytes upper limit 1053 1054 CONFIG_TPM_ST33ZP24 1055 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1056 1057 CONFIG_TPM_ST33ZP24_I2C 1058 Support for STMicroelectronics ST33ZP24 I2C devices. 1059 Requires TPM_ST33ZP24 and I2C. 1060 1061 CONFIG_TPM_ST33ZP24_SPI 1062 Support for STMicroelectronics ST33ZP24 SPI devices. 1063 Requires TPM_ST33ZP24 and SPI. 1064 1065 CONFIG_TPM_ATMEL_TWI 1066 Support for Atmel TWI TPM device. Requires I2C support. 1067 1068 CONFIG_TPM_TIS_LPC 1069 Support for generic parallel port TPM devices. Only one device 1070 per system is supported at this time. 1071 1072 CONFIG_TPM_TIS_BASE_ADDRESS 1073 Base address where the generic TPM device is mapped 1074 to. Contemporary x86 systems usually map it at 1075 0xfed40000. 1076 1077 CONFIG_TPM 1078 Define this to enable the TPM support library which provides 1079 functional interfaces to some TPM commands. 1080 Requires support for a TPM device. 1081 1082 CONFIG_TPM_AUTH_SESSIONS 1083 Define this to enable authorized functions in the TPM library. 1084 Requires CONFIG_TPM and CONFIG_SHA1. 1085 1086- USB Support: 1087 At the moment only the UHCI host controller is 1088 supported (PIP405, MIP405); define 1089 CONFIG_USB_UHCI to enable it. 1090 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1091 and define CONFIG_USB_STORAGE to enable the USB 1092 storage devices. 1093 Note: 1094 Supported are USB Keyboards and USB Floppy drives 1095 (TEAC FD-05PUB). 1096 1097 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1098 txfilltuning field in the EHCI controller on reset. 1099 1100 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1101 HW module registers. 1102 1103- USB Device: 1104 Define the below if you wish to use the USB console. 1105 Once firmware is rebuilt from a serial console issue the 1106 command "setenv stdin usbtty; setenv stdout usbtty" and 1107 attach your USB cable. The Unix command "dmesg" should print 1108 it has found a new device. The environment variable usbtty 1109 can be set to gserial or cdc_acm to enable your device to 1110 appear to a USB host as a Linux gserial device or a 1111 Common Device Class Abstract Control Model serial device. 1112 If you select usbtty = gserial you should be able to enumerate 1113 a Linux host by 1114 # modprobe usbserial vendor=0xVendorID product=0xProductID 1115 else if using cdc_acm, simply setting the environment 1116 variable usbtty to be cdc_acm should suffice. The following 1117 might be defined in YourBoardName.h 1118 1119 CONFIG_USB_DEVICE 1120 Define this to build a UDC device 1121 1122 CONFIG_USB_TTY 1123 Define this to have a tty type of device available to 1124 talk to the UDC device 1125 1126 CONFIG_USBD_HS 1127 Define this to enable the high speed support for usb 1128 device and usbtty. If this feature is enabled, a routine 1129 int is_usbd_high_speed(void) 1130 also needs to be defined by the driver to dynamically poll 1131 whether the enumeration has succeded at high speed or full 1132 speed. 1133 1134 CONFIG_SYS_CONSOLE_IS_IN_ENV 1135 Define this if you want stdin, stdout &/or stderr to 1136 be set to usbtty. 1137 1138 If you have a USB-IF assigned VendorID then you may wish to 1139 define your own vendor specific values either in BoardName.h 1140 or directly in usbd_vendor_info.h. If you don't define 1141 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1142 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1143 should pretend to be a Linux device to it's target host. 1144 1145 CONFIG_USBD_MANUFACTURER 1146 Define this string as the name of your company for 1147 - CONFIG_USBD_MANUFACTURER "my company" 1148 1149 CONFIG_USBD_PRODUCT_NAME 1150 Define this string as the name of your product 1151 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1152 1153 CONFIG_USBD_VENDORID 1154 Define this as your assigned Vendor ID from the USB 1155 Implementors Forum. This *must* be a genuine Vendor ID 1156 to avoid polluting the USB namespace. 1157 - CONFIG_USBD_VENDORID 0xFFFF 1158 1159 CONFIG_USBD_PRODUCTID 1160 Define this as the unique Product ID 1161 for your device 1162 - CONFIG_USBD_PRODUCTID 0xFFFF 1163 1164- ULPI Layer Support: 1165 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1166 the generic ULPI layer. The generic layer accesses the ULPI PHY 1167 via the platform viewport, so you need both the genric layer and 1168 the viewport enabled. Currently only Chipidea/ARC based 1169 viewport is supported. 1170 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1171 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1172 If your ULPI phy needs a different reference clock than the 1173 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1174 the appropriate value in Hz. 1175 1176- MMC Support: 1177 The MMC controller on the Intel PXA is supported. To 1178 enable this define CONFIG_MMC. The MMC can be 1179 accessed from the boot prompt by mapping the device 1180 to physical memory similar to flash. Command line is 1181 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1182 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1183 1184 CONFIG_SH_MMCIF 1185 Support for Renesas on-chip MMCIF controller 1186 1187 CONFIG_SH_MMCIF_ADDR 1188 Define the base address of MMCIF registers 1189 1190 CONFIG_SH_MMCIF_CLK 1191 Define the clock frequency for MMCIF 1192 1193 CONFIG_SUPPORT_EMMC_BOOT 1194 Enable some additional features of the eMMC boot partitions. 1195 1196 CONFIG_SUPPORT_EMMC_RPMB 1197 Enable the commands for reading, writing and programming the 1198 key for the Replay Protection Memory Block partition in eMMC. 1199 1200- USB Device Firmware Update (DFU) class support: 1201 CONFIG_DFU_OVER_USB 1202 This enables the USB portion of the DFU USB class 1203 1204 CONFIG_DFU_MMC 1205 This enables support for exposing (e)MMC devices via DFU. 1206 1207 CONFIG_DFU_NAND 1208 This enables support for exposing NAND devices via DFU. 1209 1210 CONFIG_DFU_RAM 1211 This enables support for exposing RAM via DFU. 1212 Note: DFU spec refer to non-volatile memory usage, but 1213 allow usages beyond the scope of spec - here RAM usage, 1214 one that would help mostly the developer. 1215 1216 CONFIG_SYS_DFU_DATA_BUF_SIZE 1217 Dfu transfer uses a buffer before writing data to the 1218 raw storage device. Make the size (in bytes) of this buffer 1219 configurable. The size of this buffer is also configurable 1220 through the "dfu_bufsiz" environment variable. 1221 1222 CONFIG_SYS_DFU_MAX_FILE_SIZE 1223 When updating files rather than the raw storage device, 1224 we use a static buffer to copy the file into and then write 1225 the buffer once we've been given the whole file. Define 1226 this to the maximum filesize (in bytes) for the buffer. 1227 Default is 4 MiB if undefined. 1228 1229 DFU_DEFAULT_POLL_TIMEOUT 1230 Poll timeout [ms], is the timeout a device can send to the 1231 host. The host must wait for this timeout before sending 1232 a subsequent DFU_GET_STATUS request to the device. 1233 1234 DFU_MANIFEST_POLL_TIMEOUT 1235 Poll timeout [ms], which the device sends to the host when 1236 entering dfuMANIFEST state. Host waits this timeout, before 1237 sending again an USB request to the device. 1238 1239- Journaling Flash filesystem support: 1240 CONFIG_JFFS2_NAND 1241 Define these for a default partition on a NAND device 1242 1243 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1244 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1245 Define these for a default partition on a NOR device 1246 1247- Keyboard Support: 1248 See Kconfig help for available keyboard drivers. 1249 1250 CONFIG_KEYBOARD 1251 1252 Define this to enable a custom keyboard support. 1253 This simply calls drv_keyboard_init() which must be 1254 defined in your board-specific files. This option is deprecated 1255 and is only used by novena. For new boards, use driver model 1256 instead. 1257 1258- Video support: 1259 CONFIG_FSL_DIU_FB 1260 Enable the Freescale DIU video driver. Reference boards for 1261 SOCs that have a DIU should define this macro to enable DIU 1262 support, and should also define these other macros: 1263 1264 CONFIG_SYS_DIU_ADDR 1265 CONFIG_VIDEO 1266 CONFIG_CFB_CONSOLE 1267 CONFIG_VIDEO_SW_CURSOR 1268 CONFIG_VGA_AS_SINGLE_DEVICE 1269 CONFIG_VIDEO_LOGO 1270 CONFIG_VIDEO_BMP_LOGO 1271 1272 The DIU driver will look for the 'video-mode' environment 1273 variable, and if defined, enable the DIU as a console during 1274 boot. See the documentation file doc/README.video for a 1275 description of this variable. 1276 1277- LCD Support: CONFIG_LCD 1278 1279 Define this to enable LCD support (for output to LCD 1280 display); also select one of the supported displays 1281 by defining one of these: 1282 1283 CONFIG_ATMEL_LCD: 1284 1285 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1286 1287 CONFIG_NEC_NL6448AC33: 1288 1289 NEC NL6448AC33-18. Active, color, single scan. 1290 1291 CONFIG_NEC_NL6448BC20 1292 1293 NEC NL6448BC20-08. 6.5", 640x480. 1294 Active, color, single scan. 1295 1296 CONFIG_NEC_NL6448BC33_54 1297 1298 NEC NL6448BC33-54. 10.4", 640x480. 1299 Active, color, single scan. 1300 1301 CONFIG_SHARP_16x9 1302 1303 Sharp 320x240. Active, color, single scan. 1304 It isn't 16x9, and I am not sure what it is. 1305 1306 CONFIG_SHARP_LQ64D341 1307 1308 Sharp LQ64D341 display, 640x480. 1309 Active, color, single scan. 1310 1311 CONFIG_HLD1045 1312 1313 HLD1045 display, 640x480. 1314 Active, color, single scan. 1315 1316 CONFIG_OPTREX_BW 1317 1318 Optrex CBL50840-2 NF-FW 99 22 M5 1319 or 1320 Hitachi LMG6912RPFC-00T 1321 or 1322 Hitachi SP14Q002 1323 1324 320x240. Black & white. 1325 1326 CONFIG_LCD_ALIGNMENT 1327 1328 Normally the LCD is page-aligned (typically 4KB). If this is 1329 defined then the LCD will be aligned to this value instead. 1330 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1331 here, since it is cheaper to change data cache settings on 1332 a per-section basis. 1333 1334 1335 CONFIG_LCD_ROTATION 1336 1337 Sometimes, for example if the display is mounted in portrait 1338 mode or even if it's mounted landscape but rotated by 180degree, 1339 we need to rotate our content of the display relative to the 1340 framebuffer, so that user can read the messages which are 1341 printed out. 1342 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1343 initialized with a given rotation from "vl_rot" out of 1344 "vidinfo_t" which is provided by the board specific code. 1345 The value for vl_rot is coded as following (matching to 1346 fbcon=rotate:<n> linux-kernel commandline): 1347 0 = no rotation respectively 0 degree 1348 1 = 90 degree rotation 1349 2 = 180 degree rotation 1350 3 = 270 degree rotation 1351 1352 If CONFIG_LCD_ROTATION is not defined, the console will be 1353 initialized with 0degree rotation. 1354 1355 CONFIG_LCD_BMP_RLE8 1356 1357 Support drawing of RLE8-compressed bitmaps on the LCD. 1358 1359 CONFIG_I2C_EDID 1360 1361 Enables an 'i2c edid' command which can read EDID 1362 information over I2C from an attached LCD display. 1363 1364- Splash Screen Support: CONFIG_SPLASH_SCREEN 1365 1366 If this option is set, the environment is checked for 1367 a variable "splashimage". If found, the usual display 1368 of logo, copyright and system information on the LCD 1369 is suppressed and the BMP image at the address 1370 specified in "splashimage" is loaded instead. The 1371 console is redirected to the "nulldev", too. This 1372 allows for a "silent" boot where a splash screen is 1373 loaded very quickly after power-on. 1374 1375 CONFIG_SPLASHIMAGE_GUARD 1376 1377 If this option is set, then U-Boot will prevent the environment 1378 variable "splashimage" from being set to a problematic address 1379 (see doc/README.displaying-bmps). 1380 This option is useful for targets where, due to alignment 1381 restrictions, an improperly aligned BMP image will cause a data 1382 abort. If you think you will not have problems with unaligned 1383 accesses (for example because your toolchain prevents them) 1384 there is no need to set this option. 1385 1386 CONFIG_SPLASH_SCREEN_ALIGN 1387 1388 If this option is set the splash image can be freely positioned 1389 on the screen. Environment variable "splashpos" specifies the 1390 position as "x,y". If a positive number is given it is used as 1391 number of pixel from left/top. If a negative number is given it 1392 is used as number of pixel from right/bottom. You can also 1393 specify 'm' for centering the image. 1394 1395 Example: 1396 setenv splashpos m,m 1397 => image at center of screen 1398 1399 setenv splashpos 30,20 1400 => image at x = 30 and y = 20 1401 1402 setenv splashpos -10,m 1403 => vertically centered image 1404 at x = dspWidth - bmpWidth - 9 1405 1406- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1407 1408 If this option is set, additionally to standard BMP 1409 images, gzipped BMP images can be displayed via the 1410 splashscreen support or the bmp command. 1411 1412- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1413 1414 If this option is set, 8-bit RLE compressed BMP images 1415 can be displayed via the splashscreen support or the 1416 bmp command. 1417 1418- Compression support: 1419 CONFIG_GZIP 1420 1421 Enabled by default to support gzip compressed images. 1422 1423 CONFIG_BZIP2 1424 1425 If this option is set, support for bzip2 compressed 1426 images is included. If not, only uncompressed and gzip 1427 compressed images are supported. 1428 1429 NOTE: the bzip2 algorithm requires a lot of RAM, so 1430 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1431 be at least 4MB. 1432 1433- MII/PHY support: 1434 CONFIG_PHY_ADDR 1435 1436 The address of PHY on MII bus. 1437 1438 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1439 1440 The clock frequency of the MII bus 1441 1442 CONFIG_PHY_RESET_DELAY 1443 1444 Some PHY like Intel LXT971A need extra delay after 1445 reset before any MII register access is possible. 1446 For such PHY, set this option to the usec delay 1447 required. (minimum 300usec for LXT971A) 1448 1449 CONFIG_PHY_CMD_DELAY (ppc4xx) 1450 1451 Some PHY like Intel LXT971A need extra delay after 1452 command issued before MII status register can be read 1453 1454- IP address: 1455 CONFIG_IPADDR 1456 1457 Define a default value for the IP address to use for 1458 the default Ethernet interface, in case this is not 1459 determined through e.g. bootp. 1460 (Environment variable "ipaddr") 1461 1462- Server IP address: 1463 CONFIG_SERVERIP 1464 1465 Defines a default value for the IP address of a TFTP 1466 server to contact when using the "tftboot" command. 1467 (Environment variable "serverip") 1468 1469 CONFIG_KEEP_SERVERADDR 1470 1471 Keeps the server's MAC address, in the env 'serveraddr' 1472 for passing to bootargs (like Linux's netconsole option) 1473 1474- Gateway IP address: 1475 CONFIG_GATEWAYIP 1476 1477 Defines a default value for the IP address of the 1478 default router where packets to other networks are 1479 sent to. 1480 (Environment variable "gatewayip") 1481 1482- Subnet mask: 1483 CONFIG_NETMASK 1484 1485 Defines a default value for the subnet mask (or 1486 routing prefix) which is used to determine if an IP 1487 address belongs to the local subnet or needs to be 1488 forwarded through a router. 1489 (Environment variable "netmask") 1490 1491- Multicast TFTP Mode: 1492 CONFIG_MCAST_TFTP 1493 1494 Defines whether you want to support multicast TFTP as per 1495 rfc-2090; for example to work with atftp. Lets lots of targets 1496 tftp down the same boot image concurrently. Note: the Ethernet 1497 driver in use must provide a function: mcast() to join/leave a 1498 multicast group. 1499 1500- BOOTP Recovery Mode: 1501 CONFIG_BOOTP_RANDOM_DELAY 1502 1503 If you have many targets in a network that try to 1504 boot using BOOTP, you may want to avoid that all 1505 systems send out BOOTP requests at precisely the same 1506 moment (which would happen for instance at recovery 1507 from a power failure, when all systems will try to 1508 boot, thus flooding the BOOTP server. Defining 1509 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1510 inserted before sending out BOOTP requests. The 1511 following delays are inserted then: 1512 1513 1st BOOTP request: delay 0 ... 1 sec 1514 2nd BOOTP request: delay 0 ... 2 sec 1515 3rd BOOTP request: delay 0 ... 4 sec 1516 4th and following 1517 BOOTP requests: delay 0 ... 8 sec 1518 1519 CONFIG_BOOTP_ID_CACHE_SIZE 1520 1521 BOOTP packets are uniquely identified using a 32-bit ID. The 1522 server will copy the ID from client requests to responses and 1523 U-Boot will use this to determine if it is the destination of 1524 an incoming response. Some servers will check that addresses 1525 aren't in use before handing them out (usually using an ARP 1526 ping) and therefore take up to a few hundred milliseconds to 1527 respond. Network congestion may also influence the time it 1528 takes for a response to make it back to the client. If that 1529 time is too long, U-Boot will retransmit requests. In order 1530 to allow earlier responses to still be accepted after these 1531 retransmissions, U-Boot's BOOTP client keeps a small cache of 1532 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1533 cache. The default is to keep IDs for up to four outstanding 1534 requests. Increasing this will allow U-Boot to accept offers 1535 from a BOOTP client in networks with unusually high latency. 1536 1537- DHCP Advanced Options: 1538 You can fine tune the DHCP functionality by defining 1539 CONFIG_BOOTP_* symbols: 1540 1541 CONFIG_BOOTP_NISDOMAIN 1542 CONFIG_BOOTP_BOOTFILESIZE 1543 CONFIG_BOOTP_SEND_HOSTNAME 1544 CONFIG_BOOTP_NTPSERVER 1545 CONFIG_BOOTP_TIMEOFFSET 1546 CONFIG_BOOTP_VENDOREX 1547 CONFIG_BOOTP_MAY_FAIL 1548 1549 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1550 environment variable, not the BOOTP server. 1551 1552 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1553 after the configured retry count, the call will fail 1554 instead of starting over. This can be used to fail over 1555 to Link-local IP address configuration if the DHCP server 1556 is not available. 1557 1558 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1559 to do a dynamic update of a DNS server. To do this, they 1560 need the hostname of the DHCP requester. 1561 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1562 of the "hostname" environment variable is passed as 1563 option 12 to the DHCP server. 1564 1565 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1566 1567 A 32bit value in microseconds for a delay between 1568 receiving a "DHCP Offer" and sending the "DHCP Request". 1569 This fixes a problem with certain DHCP servers that don't 1570 respond 100% of the time to a "DHCP request". E.g. On an 1571 AT91RM9200 processor running at 180MHz, this delay needed 1572 to be *at least* 15,000 usec before a Windows Server 2003 1573 DHCP server would reply 100% of the time. I recommend at 1574 least 50,000 usec to be safe. The alternative is to hope 1575 that one of the retries will be successful but note that 1576 the DHCP timeout and retry process takes a longer than 1577 this delay. 1578 1579 - Link-local IP address negotiation: 1580 Negotiate with other link-local clients on the local network 1581 for an address that doesn't require explicit configuration. 1582 This is especially useful if a DHCP server cannot be guaranteed 1583 to exist in all environments that the device must operate. 1584 1585 See doc/README.link-local for more information. 1586 1587 - MAC address from environment variables 1588 1589 FDT_SEQ_MACADDR_FROM_ENV 1590 1591 Fix-up device tree with MAC addresses fetched sequentially from 1592 environment variables. This config work on assumption that 1593 non-usable ethernet node of device-tree are either not present 1594 or their status has been marked as "disabled". 1595 1596 - CDP Options: 1597 CONFIG_CDP_DEVICE_ID 1598 1599 The device id used in CDP trigger frames. 1600 1601 CONFIG_CDP_DEVICE_ID_PREFIX 1602 1603 A two character string which is prefixed to the MAC address 1604 of the device. 1605 1606 CONFIG_CDP_PORT_ID 1607 1608 A printf format string which contains the ascii name of 1609 the port. Normally is set to "eth%d" which sets 1610 eth0 for the first Ethernet, eth1 for the second etc. 1611 1612 CONFIG_CDP_CAPABILITIES 1613 1614 A 32bit integer which indicates the device capabilities; 1615 0x00000010 for a normal host which does not forwards. 1616 1617 CONFIG_CDP_VERSION 1618 1619 An ascii string containing the version of the software. 1620 1621 CONFIG_CDP_PLATFORM 1622 1623 An ascii string containing the name of the platform. 1624 1625 CONFIG_CDP_TRIGGER 1626 1627 A 32bit integer sent on the trigger. 1628 1629 CONFIG_CDP_POWER_CONSUMPTION 1630 1631 A 16bit integer containing the power consumption of the 1632 device in .1 of milliwatts. 1633 1634 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1635 1636 A byte containing the id of the VLAN. 1637 1638- Status LED: CONFIG_LED_STATUS 1639 1640 Several configurations allow to display the current 1641 status using a LED. For instance, the LED will blink 1642 fast while running U-Boot code, stop blinking as 1643 soon as a reply to a BOOTP request was received, and 1644 start blinking slow once the Linux kernel is running 1645 (supported by a status LED driver in the Linux 1646 kernel). Defining CONFIG_LED_STATUS enables this 1647 feature in U-Boot. 1648 1649 Additional options: 1650 1651 CONFIG_LED_STATUS_GPIO 1652 The status LED can be connected to a GPIO pin. 1653 In such cases, the gpio_led driver can be used as a 1654 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1655 to include the gpio_led driver in the U-Boot binary. 1656 1657 CONFIG_GPIO_LED_INVERTED_TABLE 1658 Some GPIO connected LEDs may have inverted polarity in which 1659 case the GPIO high value corresponds to LED off state and 1660 GPIO low value corresponds to LED on state. 1661 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1662 with a list of GPIO LEDs that have inverted polarity. 1663 1664- I2C Support: CONFIG_SYS_I2C 1665 1666 This enable the NEW i2c subsystem, and will allow you to use 1667 i2c commands at the u-boot command line (as long as you set 1668 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1669 based realtime clock chips or other i2c devices. See 1670 common/cmd_i2c.c for a description of the command line 1671 interface. 1672 1673 ported i2c driver to the new framework: 1674 - drivers/i2c/soft_i2c.c: 1675 - activate first bus with CONFIG_SYS_I2C_SOFT define 1676 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1677 for defining speed and slave address 1678 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1679 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1680 for defining speed and slave address 1681 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1682 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1683 for defining speed and slave address 1684 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1685 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1686 for defining speed and slave address 1687 1688 - drivers/i2c/fsl_i2c.c: 1689 - activate i2c driver with CONFIG_SYS_I2C_FSL 1690 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1691 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1692 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1693 bus. 1694 - If your board supports a second fsl i2c bus, define 1695 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1696 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1697 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1698 second bus. 1699 1700 - drivers/i2c/tegra_i2c.c: 1701 - activate this driver with CONFIG_SYS_I2C_TEGRA 1702 - This driver adds 4 i2c buses with a fix speed from 1703 100000 and the slave addr 0! 1704 1705 - drivers/i2c/ppc4xx_i2c.c 1706 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1707 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1708 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1709 1710 - drivers/i2c/i2c_mxc.c 1711 - activate this driver with CONFIG_SYS_I2C_MXC 1712 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1713 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1714 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1715 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1716 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1717 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1718 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1719 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1720 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1721 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1722 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1723 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1724 If those defines are not set, default value is 100000 1725 for speed, and 0 for slave. 1726 1727 - drivers/i2c/rcar_i2c.c: 1728 - activate this driver with CONFIG_SYS_I2C_RCAR 1729 - This driver adds 4 i2c buses 1730 1731 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1732 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1733 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1734 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1735 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1736 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1737 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1738 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1739 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1740 1741 - drivers/i2c/sh_i2c.c: 1742 - activate this driver with CONFIG_SYS_I2C_SH 1743 - This driver adds from 2 to 5 i2c buses 1744 1745 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1746 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1747 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1748 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1749 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1750 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1751 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1752 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1753 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1754 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1755 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1756 1757 - drivers/i2c/omap24xx_i2c.c 1758 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1759 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1760 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1761 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1762 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1763 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1764 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1765 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1766 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1767 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1768 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1769 1770 - drivers/i2c/zynq_i2c.c 1771 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1772 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1773 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1774 1775 - drivers/i2c/s3c24x0_i2c.c: 1776 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1777 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1778 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1779 with a fix speed from 100000 and the slave addr 0! 1780 1781 - drivers/i2c/ihs_i2c.c 1782 - activate this driver with CONFIG_SYS_I2C_IHS 1783 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1784 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1785 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1786 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1787 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1788 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1789 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1790 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1791 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1792 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1793 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1794 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1795 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1796 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1797 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1798 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1799 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1800 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1801 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1802 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1803 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1804 1805 additional defines: 1806 1807 CONFIG_SYS_NUM_I2C_BUSES 1808 Hold the number of i2c buses you want to use. 1809 1810 CONFIG_SYS_I2C_DIRECT_BUS 1811 define this, if you don't use i2c muxes on your hardware. 1812 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1813 omit this define. 1814 1815 CONFIG_SYS_I2C_MAX_HOPS 1816 define how many muxes are maximal consecutively connected 1817 on one i2c bus. If you not use i2c muxes, omit this 1818 define. 1819 1820 CONFIG_SYS_I2C_BUSES 1821 hold a list of buses you want to use, only used if 1822 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1823 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1824 CONFIG_SYS_NUM_I2C_BUSES = 9: 1825 1826 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1827 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1828 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1829 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1830 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1831 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1832 {1, {I2C_NULL_HOP}}, \ 1833 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1834 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1835 } 1836 1837 which defines 1838 bus 0 on adapter 0 without a mux 1839 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1840 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1841 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1842 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1843 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1844 bus 6 on adapter 1 without a mux 1845 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1846 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1847 1848 If you do not have i2c muxes on your board, omit this define. 1849 1850- Legacy I2C Support: 1851 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1852 then the following macros need to be defined (examples are 1853 from include/configs/lwmon.h): 1854 1855 I2C_INIT 1856 1857 (Optional). Any commands necessary to enable the I2C 1858 controller or configure ports. 1859 1860 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1861 1862 I2C_ACTIVE 1863 1864 The code necessary to make the I2C data line active 1865 (driven). If the data line is open collector, this 1866 define can be null. 1867 1868 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1869 1870 I2C_TRISTATE 1871 1872 The code necessary to make the I2C data line tri-stated 1873 (inactive). If the data line is open collector, this 1874 define can be null. 1875 1876 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1877 1878 I2C_READ 1879 1880 Code that returns true if the I2C data line is high, 1881 false if it is low. 1882 1883 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1884 1885 I2C_SDA(bit) 1886 1887 If <bit> is true, sets the I2C data line high. If it 1888 is false, it clears it (low). 1889 1890 eg: #define I2C_SDA(bit) \ 1891 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1892 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1893 1894 I2C_SCL(bit) 1895 1896 If <bit> is true, sets the I2C clock line high. If it 1897 is false, it clears it (low). 1898 1899 eg: #define I2C_SCL(bit) \ 1900 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1901 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1902 1903 I2C_DELAY 1904 1905 This delay is invoked four times per clock cycle so this 1906 controls the rate of data transfer. The data rate thus 1907 is 1 / (I2C_DELAY * 4). Often defined to be something 1908 like: 1909 1910 #define I2C_DELAY udelay(2) 1911 1912 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1913 1914 If your arch supports the generic GPIO framework (asm/gpio.h), 1915 then you may alternatively define the two GPIOs that are to be 1916 used as SCL / SDA. Any of the previous I2C_xxx macros will 1917 have GPIO-based defaults assigned to them as appropriate. 1918 1919 You should define these to the GPIO value as given directly to 1920 the generic GPIO functions. 1921 1922 CONFIG_SYS_I2C_INIT_BOARD 1923 1924 When a board is reset during an i2c bus transfer 1925 chips might think that the current transfer is still 1926 in progress. On some boards it is possible to access 1927 the i2c SCLK line directly, either by using the 1928 processor pin as a GPIO or by having a second pin 1929 connected to the bus. If this option is defined a 1930 custom i2c_init_board() routine in boards/xxx/board.c 1931 is run early in the boot sequence. 1932 1933 CONFIG_I2C_MULTI_BUS 1934 1935 This option allows the use of multiple I2C buses, each of which 1936 must have a controller. At any point in time, only one bus is 1937 active. To switch to a different bus, use the 'i2c dev' command. 1938 Note that bus numbering is zero-based. 1939 1940 CONFIG_SYS_I2C_NOPROBES 1941 1942 This option specifies a list of I2C devices that will be skipped 1943 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1944 is set, specify a list of bus-device pairs. Otherwise, specify 1945 a 1D array of device addresses 1946 1947 e.g. 1948 #undef CONFIG_I2C_MULTI_BUS 1949 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1950 1951 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1952 1953 #define CONFIG_I2C_MULTI_BUS 1954 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1955 1956 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1957 1958 CONFIG_SYS_SPD_BUS_NUM 1959 1960 If defined, then this indicates the I2C bus number for DDR SPD. 1961 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1962 1963 CONFIG_SYS_RTC_BUS_NUM 1964 1965 If defined, then this indicates the I2C bus number for the RTC. 1966 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1967 1968 CONFIG_SOFT_I2C_READ_REPEATED_START 1969 1970 defining this will force the i2c_read() function in 1971 the soft_i2c driver to perform an I2C repeated start 1972 between writing the address pointer and reading the 1973 data. If this define is omitted the default behaviour 1974 of doing a stop-start sequence will be used. Most I2C 1975 devices can use either method, but some require one or 1976 the other. 1977 1978- SPI Support: CONFIG_SPI 1979 1980 Enables SPI driver (so far only tested with 1981 SPI EEPROM, also an instance works with Crystal A/D and 1982 D/As on the SACSng board) 1983 1984 CONFIG_SOFT_SPI 1985 1986 Enables a software (bit-bang) SPI driver rather than 1987 using hardware support. This is a general purpose 1988 driver that only requires three general I/O port pins 1989 (two outputs, one input) to function. If this is 1990 defined, the board configuration must define several 1991 SPI configuration items (port pins to use, etc). For 1992 an example, see include/configs/sacsng.h. 1993 1994 CONFIG_HARD_SPI 1995 1996 Enables a hardware SPI driver for general-purpose reads 1997 and writes. As with CONFIG_SOFT_SPI, the board configuration 1998 must define a list of chip-select function pointers. 1999 Currently supported on some MPC8xxx processors. For an 2000 example, see include/configs/mpc8349emds.h. 2001 2002 CONFIG_SYS_SPI_MXC_WAIT 2003 Timeout for waiting until spi transfer completed. 2004 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 2005 2006- FPGA Support: CONFIG_FPGA 2007 2008 Enables FPGA subsystem. 2009 2010 CONFIG_FPGA_<vendor> 2011 2012 Enables support for specific chip vendors. 2013 (ALTERA, XILINX) 2014 2015 CONFIG_FPGA_<family> 2016 2017 Enables support for FPGA family. 2018 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2019 2020 CONFIG_FPGA_COUNT 2021 2022 Specify the number of FPGA devices to support. 2023 2024 CONFIG_SYS_FPGA_PROG_FEEDBACK 2025 2026 Enable printing of hash marks during FPGA configuration. 2027 2028 CONFIG_SYS_FPGA_CHECK_BUSY 2029 2030 Enable checks on FPGA configuration interface busy 2031 status by the configuration function. This option 2032 will require a board or device specific function to 2033 be written. 2034 2035 CONFIG_FPGA_DELAY 2036 2037 If defined, a function that provides delays in the FPGA 2038 configuration driver. 2039 2040 CONFIG_SYS_FPGA_CHECK_CTRLC 2041 Allow Control-C to interrupt FPGA configuration 2042 2043 CONFIG_SYS_FPGA_CHECK_ERROR 2044 2045 Check for configuration errors during FPGA bitfile 2046 loading. For example, abort during Virtex II 2047 configuration if the INIT_B line goes low (which 2048 indicated a CRC error). 2049 2050 CONFIG_SYS_FPGA_WAIT_INIT 2051 2052 Maximum time to wait for the INIT_B line to de-assert 2053 after PROB_B has been de-asserted during a Virtex II 2054 FPGA configuration sequence. The default time is 500 2055 ms. 2056 2057 CONFIG_SYS_FPGA_WAIT_BUSY 2058 2059 Maximum time to wait for BUSY to de-assert during 2060 Virtex II FPGA configuration. The default is 5 ms. 2061 2062 CONFIG_SYS_FPGA_WAIT_CONFIG 2063 2064 Time to wait after FPGA configuration. The default is 2065 200 ms. 2066 2067- Configuration Management: 2068 CONFIG_BUILD_TARGET 2069 2070 Some SoCs need special image types (e.g. U-Boot binary 2071 with a special header) as build targets. By defining 2072 CONFIG_BUILD_TARGET in the SoC / board header, this 2073 special image will be automatically built upon calling 2074 make / buildman. 2075 2076 CONFIG_IDENT_STRING 2077 2078 If defined, this string will be added to the U-Boot 2079 version information (U_BOOT_VERSION) 2080 2081- Vendor Parameter Protection: 2082 2083 U-Boot considers the values of the environment 2084 variables "serial#" (Board Serial Number) and 2085 "ethaddr" (Ethernet Address) to be parameters that 2086 are set once by the board vendor / manufacturer, and 2087 protects these variables from casual modification by 2088 the user. Once set, these variables are read-only, 2089 and write or delete attempts are rejected. You can 2090 change this behaviour: 2091 2092 If CONFIG_ENV_OVERWRITE is #defined in your config 2093 file, the write protection for vendor parameters is 2094 completely disabled. Anybody can change or delete 2095 these parameters. 2096 2097 Alternatively, if you define _both_ an ethaddr in the 2098 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2099 Ethernet address is installed in the environment, 2100 which can be changed exactly ONCE by the user. [The 2101 serial# is unaffected by this, i. e. it remains 2102 read-only.] 2103 2104 The same can be accomplished in a more flexible way 2105 for any variable by configuring the type of access 2106 to allow for those variables in the ".flags" variable 2107 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2108 2109- Protected RAM: 2110 CONFIG_PRAM 2111 2112 Define this variable to enable the reservation of 2113 "protected RAM", i. e. RAM which is not overwritten 2114 by U-Boot. Define CONFIG_PRAM to hold the number of 2115 kB you want to reserve for pRAM. You can overwrite 2116 this default value by defining an environment 2117 variable "pram" to the number of kB you want to 2118 reserve. Note that the board info structure will 2119 still show the full amount of RAM. If pRAM is 2120 reserved, a new environment variable "mem" will 2121 automatically be defined to hold the amount of 2122 remaining RAM in a form that can be passed as boot 2123 argument to Linux, for instance like that: 2124 2125 setenv bootargs ... mem=\${mem} 2126 saveenv 2127 2128 This way you can tell Linux not to use this memory, 2129 either, which results in a memory region that will 2130 not be affected by reboots. 2131 2132 *WARNING* If your board configuration uses automatic 2133 detection of the RAM size, you must make sure that 2134 this memory test is non-destructive. So far, the 2135 following board configurations are known to be 2136 "pRAM-clean": 2137 2138 IVMS8, IVML24, SPD8xx, 2139 HERMES, IP860, RPXlite, LWMON, 2140 FLAGADM 2141 2142- Access to physical memory region (> 4GB) 2143 Some basic support is provided for operations on memory not 2144 normally accessible to U-Boot - e.g. some architectures 2145 support access to more than 4GB of memory on 32-bit 2146 machines using physical address extension or similar. 2147 Define CONFIG_PHYSMEM to access this basic support, which 2148 currently only supports clearing the memory. 2149 2150- Error Recovery: 2151 CONFIG_NET_RETRY_COUNT 2152 2153 This variable defines the number of retries for 2154 network operations like ARP, RARP, TFTP, or BOOTP 2155 before giving up the operation. If not defined, a 2156 default value of 5 is used. 2157 2158 CONFIG_ARP_TIMEOUT 2159 2160 Timeout waiting for an ARP reply in milliseconds. 2161 2162 CONFIG_NFS_TIMEOUT 2163 2164 Timeout in milliseconds used in NFS protocol. 2165 If you encounter "ERROR: Cannot umount" in nfs command, 2166 try longer timeout such as 2167 #define CONFIG_NFS_TIMEOUT 10000UL 2168 2169- Command Interpreter: 2170 CONFIG_SYS_PROMPT_HUSH_PS2 2171 2172 This defines the secondary prompt string, which is 2173 printed when the command interpreter needs more input 2174 to complete a command. Usually "> ". 2175 2176 Note: 2177 2178 In the current implementation, the local variables 2179 space and global environment variables space are 2180 separated. Local variables are those you define by 2181 simply typing `name=value'. To access a local 2182 variable later on, you have write `$name' or 2183 `${name}'; to execute the contents of a variable 2184 directly type `$name' at the command prompt. 2185 2186 Global environment variables are those you use 2187 setenv/printenv to work with. To run a command stored 2188 in such a variable, you need to use the run command, 2189 and you must not use the '$' sign to access them. 2190 2191 To store commands and special characters in a 2192 variable, please use double quotation marks 2193 surrounding the whole text of the variable, instead 2194 of the backslashes before semicolons and special 2195 symbols. 2196 2197- Command Line Editing and History: 2198 CONFIG_CMDLINE_PS_SUPPORT 2199 2200 Enable support for changing the command prompt string 2201 at run-time. Only static string is supported so far. 2202 The string is obtained from environment variables PS1 2203 and PS2. 2204 2205- Default Environment: 2206 CONFIG_EXTRA_ENV_SETTINGS 2207 2208 Define this to contain any number of null terminated 2209 strings (variable = value pairs) that will be part of 2210 the default environment compiled into the boot image. 2211 2212 For example, place something like this in your 2213 board's config file: 2214 2215 #define CONFIG_EXTRA_ENV_SETTINGS \ 2216 "myvar1=value1\0" \ 2217 "myvar2=value2\0" 2218 2219 Warning: This method is based on knowledge about the 2220 internal format how the environment is stored by the 2221 U-Boot code. This is NOT an official, exported 2222 interface! Although it is unlikely that this format 2223 will change soon, there is no guarantee either. 2224 You better know what you are doing here. 2225 2226 Note: overly (ab)use of the default environment is 2227 discouraged. Make sure to check other ways to preset 2228 the environment like the "source" command or the 2229 boot command first. 2230 2231 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2232 2233 Define this in order to add variables describing certain 2234 run-time determined information about the hardware to the 2235 environment. These will be named board_name, board_rev. 2236 2237 CONFIG_DELAY_ENVIRONMENT 2238 2239 Normally the environment is loaded when the board is 2240 initialised so that it is available to U-Boot. This inhibits 2241 that so that the environment is not available until 2242 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2243 this is instead controlled by the value of 2244 /config/load-environment. 2245 2246- Serial Flash support 2247 Usage requires an initial 'sf probe' to define the serial 2248 flash parameters, followed by read/write/erase/update 2249 commands. 2250 2251 The following defaults may be provided by the platform 2252 to handle the common case when only a single serial 2253 flash is present on the system. 2254 2255 CONFIG_SF_DEFAULT_BUS Bus identifier 2256 CONFIG_SF_DEFAULT_CS Chip-select 2257 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2258 CONFIG_SF_DEFAULT_SPEED in Hz 2259 2260 2261- TFTP Fixed UDP Port: 2262 CONFIG_TFTP_PORT 2263 2264 If this is defined, the environment variable tftpsrcp 2265 is used to supply the TFTP UDP source port value. 2266 If tftpsrcp isn't defined, the normal pseudo-random port 2267 number generator is used. 2268 2269 Also, the environment variable tftpdstp is used to supply 2270 the TFTP UDP destination port value. If tftpdstp isn't 2271 defined, the normal port 69 is used. 2272 2273 The purpose for tftpsrcp is to allow a TFTP server to 2274 blindly start the TFTP transfer using the pre-configured 2275 target IP address and UDP port. This has the effect of 2276 "punching through" the (Windows XP) firewall, allowing 2277 the remainder of the TFTP transfer to proceed normally. 2278 A better solution is to properly configure the firewall, 2279 but sometimes that is not allowed. 2280 2281- bootcount support: 2282 CONFIG_AT91SAM9XE 2283 enable special bootcounter support on at91sam9xe based boards. 2284 CONFIG_BOOTCOUNT_RAM 2285 enable support for the bootcounter in RAM 2286 CONFIG_BOOTCOUNT_I2C 2287 enable support for the bootcounter on an i2c (like RTC) device. 2288 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address 2289 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for 2290 the bootcounter. 2291 CONFIG_BOOTCOUNT_ALEN = address len 2292 CONFIG_BOOTCOUNT_EXT 2293 enable support for the bootcounter in EXT filesystem 2294 CONFIG_SYS_BOOTCOUNT_ADDR = RAM address used for read 2295 and write. 2296 CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE = interface 2297 CONFIG_SYS_BOOTCOUNT_EXT_DEVPART = device and part 2298 CONFIG_SYS_BOOTCOUNT_EXT_NAME = filename 2299 2300- Show boot progress: 2301 CONFIG_SHOW_BOOT_PROGRESS 2302 2303 Defining this option allows to add some board- 2304 specific code (calling a user-provided function 2305 "show_boot_progress(int)") that enables you to show 2306 the system's boot progress on some display (for 2307 example, some LED's) on your board. At the moment, 2308 the following checkpoints are implemented: 2309 2310 2311Legacy uImage format: 2312 2313 Arg Where When 2314 1 common/cmd_bootm.c before attempting to boot an image 2315 -1 common/cmd_bootm.c Image header has bad magic number 2316 2 common/cmd_bootm.c Image header has correct magic number 2317 -2 common/cmd_bootm.c Image header has bad checksum 2318 3 common/cmd_bootm.c Image header has correct checksum 2319 -3 common/cmd_bootm.c Image data has bad checksum 2320 4 common/cmd_bootm.c Image data has correct checksum 2321 -4 common/cmd_bootm.c Image is for unsupported architecture 2322 5 common/cmd_bootm.c Architecture check OK 2323 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2324 6 common/cmd_bootm.c Image Type check OK 2325 -6 common/cmd_bootm.c gunzip uncompression error 2326 -7 common/cmd_bootm.c Unimplemented compression type 2327 7 common/cmd_bootm.c Uncompression OK 2328 8 common/cmd_bootm.c No uncompress/copy overwrite error 2329 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2330 2331 9 common/image.c Start initial ramdisk verification 2332 -10 common/image.c Ramdisk header has bad magic number 2333 -11 common/image.c Ramdisk header has bad checksum 2334 10 common/image.c Ramdisk header is OK 2335 -12 common/image.c Ramdisk data has bad checksum 2336 11 common/image.c Ramdisk data has correct checksum 2337 12 common/image.c Ramdisk verification complete, start loading 2338 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2339 13 common/image.c Start multifile image verification 2340 14 common/image.c No initial ramdisk, no multifile, continue. 2341 2342 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2343 2344 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2345 -31 post/post.c POST test failed, detected by post_output_backlog() 2346 -32 post/post.c POST test failed, detected by post_run_single() 2347 2348 34 common/cmd_doc.c before loading a Image from a DOC device 2349 -35 common/cmd_doc.c Bad usage of "doc" command 2350 35 common/cmd_doc.c correct usage of "doc" command 2351 -36 common/cmd_doc.c No boot device 2352 36 common/cmd_doc.c correct boot device 2353 -37 common/cmd_doc.c Unknown Chip ID on boot device 2354 37 common/cmd_doc.c correct chip ID found, device available 2355 -38 common/cmd_doc.c Read Error on boot device 2356 38 common/cmd_doc.c reading Image header from DOC device OK 2357 -39 common/cmd_doc.c Image header has bad magic number 2358 39 common/cmd_doc.c Image header has correct magic number 2359 -40 common/cmd_doc.c Error reading Image from DOC device 2360 40 common/cmd_doc.c Image header has correct magic number 2361 41 common/cmd_ide.c before loading a Image from a IDE device 2362 -42 common/cmd_ide.c Bad usage of "ide" command 2363 42 common/cmd_ide.c correct usage of "ide" command 2364 -43 common/cmd_ide.c No boot device 2365 43 common/cmd_ide.c boot device found 2366 -44 common/cmd_ide.c Device not available 2367 44 common/cmd_ide.c Device available 2368 -45 common/cmd_ide.c wrong partition selected 2369 45 common/cmd_ide.c partition selected 2370 -46 common/cmd_ide.c Unknown partition table 2371 46 common/cmd_ide.c valid partition table found 2372 -47 common/cmd_ide.c Invalid partition type 2373 47 common/cmd_ide.c correct partition type 2374 -48 common/cmd_ide.c Error reading Image Header on boot device 2375 48 common/cmd_ide.c reading Image Header from IDE device OK 2376 -49 common/cmd_ide.c Image header has bad magic number 2377 49 common/cmd_ide.c Image header has correct magic number 2378 -50 common/cmd_ide.c Image header has bad checksum 2379 50 common/cmd_ide.c Image header has correct checksum 2380 -51 common/cmd_ide.c Error reading Image from IDE device 2381 51 common/cmd_ide.c reading Image from IDE device OK 2382 52 common/cmd_nand.c before loading a Image from a NAND device 2383 -53 common/cmd_nand.c Bad usage of "nand" command 2384 53 common/cmd_nand.c correct usage of "nand" command 2385 -54 common/cmd_nand.c No boot device 2386 54 common/cmd_nand.c boot device found 2387 -55 common/cmd_nand.c Unknown Chip ID on boot device 2388 55 common/cmd_nand.c correct chip ID found, device available 2389 -56 common/cmd_nand.c Error reading Image Header on boot device 2390 56 common/cmd_nand.c reading Image Header from NAND device OK 2391 -57 common/cmd_nand.c Image header has bad magic number 2392 57 common/cmd_nand.c Image header has correct magic number 2393 -58 common/cmd_nand.c Error reading Image from NAND device 2394 58 common/cmd_nand.c reading Image from NAND device OK 2395 2396 -60 common/env_common.c Environment has a bad CRC, using default 2397 2398 64 net/eth.c starting with Ethernet configuration. 2399 -64 net/eth.c no Ethernet found. 2400 65 net/eth.c Ethernet found. 2401 2402 -80 common/cmd_net.c usage wrong 2403 80 common/cmd_net.c before calling net_loop() 2404 -81 common/cmd_net.c some error in net_loop() occurred 2405 81 common/cmd_net.c net_loop() back without error 2406 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2407 82 common/cmd_net.c trying automatic boot 2408 83 common/cmd_net.c running "source" command 2409 -83 common/cmd_net.c some error in automatic boot or "source" command 2410 84 common/cmd_net.c end without errors 2411 2412FIT uImage format: 2413 2414 Arg Where When 2415 100 common/cmd_bootm.c Kernel FIT Image has correct format 2416 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2417 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2418 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2419 102 common/cmd_bootm.c Kernel unit name specified 2420 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2421 103 common/cmd_bootm.c Found configuration node 2422 104 common/cmd_bootm.c Got kernel subimage node offset 2423 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2424 105 common/cmd_bootm.c Kernel subimage hash verification OK 2425 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2426 106 common/cmd_bootm.c Architecture check OK 2427 -106 common/cmd_bootm.c Kernel subimage has wrong type 2428 107 common/cmd_bootm.c Kernel subimage type OK 2429 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2430 108 common/cmd_bootm.c Got kernel subimage data/size 2431 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2432 -109 common/cmd_bootm.c Can't get kernel subimage type 2433 -110 common/cmd_bootm.c Can't get kernel subimage comp 2434 -111 common/cmd_bootm.c Can't get kernel subimage os 2435 -112 common/cmd_bootm.c Can't get kernel subimage load address 2436 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2437 2438 120 common/image.c Start initial ramdisk verification 2439 -120 common/image.c Ramdisk FIT image has incorrect format 2440 121 common/image.c Ramdisk FIT image has correct format 2441 122 common/image.c No ramdisk subimage unit name, using configuration 2442 -122 common/image.c Can't get configuration for ramdisk subimage 2443 123 common/image.c Ramdisk unit name specified 2444 -124 common/image.c Can't get ramdisk subimage node offset 2445 125 common/image.c Got ramdisk subimage node offset 2446 -125 common/image.c Ramdisk subimage hash verification failed 2447 126 common/image.c Ramdisk subimage hash verification OK 2448 -126 common/image.c Ramdisk subimage for unsupported architecture 2449 127 common/image.c Architecture check OK 2450 -127 common/image.c Can't get ramdisk subimage data/size 2451 128 common/image.c Got ramdisk subimage data/size 2452 129 common/image.c Can't get ramdisk load address 2453 -129 common/image.c Got ramdisk load address 2454 2455 -130 common/cmd_doc.c Incorrect FIT image format 2456 131 common/cmd_doc.c FIT image format OK 2457 2458 -140 common/cmd_ide.c Incorrect FIT image format 2459 141 common/cmd_ide.c FIT image format OK 2460 2461 -150 common/cmd_nand.c Incorrect FIT image format 2462 151 common/cmd_nand.c FIT image format OK 2463 2464- legacy image format: 2465 CONFIG_IMAGE_FORMAT_LEGACY 2466 enables the legacy image format support in U-Boot. 2467 2468 Default: 2469 enabled if CONFIG_FIT_SIGNATURE is not defined. 2470 2471 CONFIG_DISABLE_IMAGE_LEGACY 2472 disable the legacy image format 2473 2474 This define is introduced, as the legacy image format is 2475 enabled per default for backward compatibility. 2476 2477- Standalone program support: 2478 CONFIG_STANDALONE_LOAD_ADDR 2479 2480 This option defines a board specific value for the 2481 address where standalone program gets loaded, thus 2482 overwriting the architecture dependent default 2483 settings. 2484 2485- Frame Buffer Address: 2486 CONFIG_FB_ADDR 2487 2488 Define CONFIG_FB_ADDR if you want to use specific 2489 address for frame buffer. This is typically the case 2490 when using a graphics controller has separate video 2491 memory. U-Boot will then place the frame buffer at 2492 the given address instead of dynamically reserving it 2493 in system RAM by calling lcd_setmem(), which grabs 2494 the memory for the frame buffer depending on the 2495 configured panel size. 2496 2497 Please see board_init_f function. 2498 2499- Automatic software updates via TFTP server 2500 CONFIG_UPDATE_TFTP 2501 CONFIG_UPDATE_TFTP_CNT_MAX 2502 CONFIG_UPDATE_TFTP_MSEC_MAX 2503 2504 These options enable and control the auto-update feature; 2505 for a more detailed description refer to doc/README.update. 2506 2507- MTD Support (mtdparts command, UBI support) 2508 CONFIG_MTD_DEVICE 2509 2510 Adds the MTD device infrastructure from the Linux kernel. 2511 Needed for mtdparts command support. 2512 2513 CONFIG_MTD_PARTITIONS 2514 2515 Adds the MTD partitioning infrastructure from the Linux 2516 kernel. Needed for UBI support. 2517 2518- UBI support 2519 CONFIG_UBI_SILENCE_MSG 2520 2521 Make the verbose messages from UBI stop printing. This leaves 2522 warnings and errors enabled. 2523 2524 2525 CONFIG_MTD_UBI_WL_THRESHOLD 2526 This parameter defines the maximum difference between the highest 2527 erase counter value and the lowest erase counter value of eraseblocks 2528 of UBI devices. When this threshold is exceeded, UBI starts performing 2529 wear leveling by means of moving data from eraseblock with low erase 2530 counter to eraseblocks with high erase counter. 2531 2532 The default value should be OK for SLC NAND flashes, NOR flashes and 2533 other flashes which have eraseblock life-cycle 100000 or more. 2534 However, in case of MLC NAND flashes which typically have eraseblock 2535 life-cycle less than 10000, the threshold should be lessened (e.g., 2536 to 128 or 256, although it does not have to be power of 2). 2537 2538 default: 4096 2539 2540 CONFIG_MTD_UBI_BEB_LIMIT 2541 This option specifies the maximum bad physical eraseblocks UBI 2542 expects on the MTD device (per 1024 eraseblocks). If the 2543 underlying flash does not admit of bad eraseblocks (e.g. NOR 2544 flash), this value is ignored. 2545 2546 NAND datasheets often specify the minimum and maximum NVM 2547 (Number of Valid Blocks) for the flashes' endurance lifetime. 2548 The maximum expected bad eraseblocks per 1024 eraseblocks 2549 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2550 which gives 20 for most NANDs (MaxNVB is basically the total 2551 count of eraseblocks on the chip). 2552 2553 To put it differently, if this value is 20, UBI will try to 2554 reserve about 1.9% of physical eraseblocks for bad blocks 2555 handling. And that will be 1.9% of eraseblocks on the entire 2556 NAND chip, not just the MTD partition UBI attaches. This means 2557 that if you have, say, a NAND flash chip admits maximum 40 bad 2558 eraseblocks, and it is split on two MTD partitions of the same 2559 size, UBI will reserve 40 eraseblocks when attaching a 2560 partition. 2561 2562 default: 20 2563 2564 CONFIG_MTD_UBI_FASTMAP 2565 Fastmap is a mechanism which allows attaching an UBI device 2566 in nearly constant time. Instead of scanning the whole MTD device it 2567 only has to locate a checkpoint (called fastmap) on the device. 2568 The on-flash fastmap contains all information needed to attach 2569 the device. Using fastmap makes only sense on large devices where 2570 attaching by scanning takes long. UBI will not automatically install 2571 a fastmap on old images, but you can set the UBI parameter 2572 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2573 that fastmap-enabled images are still usable with UBI implementations 2574 without fastmap support. On typical flash devices the whole fastmap 2575 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2576 2577 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2578 Set this parameter to enable fastmap automatically on images 2579 without a fastmap. 2580 default: 0 2581 2582 CONFIG_MTD_UBI_FM_DEBUG 2583 Enable UBI fastmap debug 2584 default: 0 2585 2586- UBIFS support 2587 CONFIG_UBIFS_SILENCE_MSG 2588 2589 Make the verbose messages from UBIFS stop printing. This leaves 2590 warnings and errors enabled. 2591 2592- SPL framework 2593 CONFIG_SPL 2594 Enable building of SPL globally. 2595 2596 CONFIG_SPL_LDSCRIPT 2597 LDSCRIPT for linking the SPL binary. 2598 2599 CONFIG_SPL_MAX_FOOTPRINT 2600 Maximum size in memory allocated to the SPL, BSS included. 2601 When defined, the linker checks that the actual memory 2602 used by SPL from _start to __bss_end does not exceed it. 2603 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2604 must not be both defined at the same time. 2605 2606 CONFIG_SPL_MAX_SIZE 2607 Maximum size of the SPL image (text, data, rodata, and 2608 linker lists sections), BSS excluded. 2609 When defined, the linker checks that the actual size does 2610 not exceed it. 2611 2612 CONFIG_SPL_TEXT_BASE 2613 TEXT_BASE for linking the SPL binary. 2614 2615 CONFIG_SPL_RELOC_TEXT_BASE 2616 Address to relocate to. If unspecified, this is equal to 2617 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2618 2619 CONFIG_SPL_BSS_START_ADDR 2620 Link address for the BSS within the SPL binary. 2621 2622 CONFIG_SPL_BSS_MAX_SIZE 2623 Maximum size in memory allocated to the SPL BSS. 2624 When defined, the linker checks that the actual memory used 2625 by SPL from __bss_start to __bss_end does not exceed it. 2626 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2627 must not be both defined at the same time. 2628 2629 CONFIG_SPL_STACK 2630 Adress of the start of the stack SPL will use 2631 2632 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2633 When defined, SPL will panic() if the image it has 2634 loaded does not have a signature. 2635 Defining this is useful when code which loads images 2636 in SPL cannot guarantee that absolutely all read errors 2637 will be caught. 2638 An example is the LPC32XX MLC NAND driver, which will 2639 consider that a completely unreadable NAND block is bad, 2640 and thus should be skipped silently. 2641 2642 CONFIG_SPL_RELOC_STACK 2643 Adress of the start of the stack SPL will use after 2644 relocation. If unspecified, this is equal to 2645 CONFIG_SPL_STACK. 2646 2647 CONFIG_SYS_SPL_MALLOC_START 2648 Starting address of the malloc pool used in SPL. 2649 When this option is set the full malloc is used in SPL and 2650 it is set up by spl_init() and before that, the simple malloc() 2651 can be used if CONFIG_SYS_MALLOC_F is defined. 2652 2653 CONFIG_SYS_SPL_MALLOC_SIZE 2654 The size of the malloc pool used in SPL. 2655 2656 CONFIG_SPL_OS_BOOT 2657 Enable booting directly to an OS from SPL. 2658 See also: doc/README.falcon 2659 2660 CONFIG_SPL_DISPLAY_PRINT 2661 For ARM, enable an optional function to print more information 2662 about the running system. 2663 2664 CONFIG_SPL_INIT_MINIMAL 2665 Arch init code should be built for a very small image 2666 2667 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2668 Partition on the MMC to load U-Boot from when the MMC is being 2669 used in raw mode 2670 2671 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2672 Sector to load kernel uImage from when MMC is being 2673 used in raw mode (for Falcon mode) 2674 2675 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2676 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2677 Sector and number of sectors to load kernel argument 2678 parameters from when MMC is being used in raw mode 2679 (for falcon mode) 2680 2681 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2682 Partition on the MMC to load U-Boot from when the MMC is being 2683 used in fs mode 2684 2685 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2686 Filename to read to load U-Boot when reading from filesystem 2687 2688 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2689 Filename to read to load kernel uImage when reading 2690 from filesystem (for Falcon mode) 2691 2692 CONFIG_SPL_FS_LOAD_ARGS_NAME 2693 Filename to read to load kernel argument parameters 2694 when reading from filesystem (for Falcon mode) 2695 2696 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2697 Set this for NAND SPL on PPC mpc83xx targets, so that 2698 start.S waits for the rest of the SPL to load before 2699 continuing (the hardware starts execution after just 2700 loading the first page rather than the full 4K). 2701 2702 CONFIG_SPL_SKIP_RELOCATE 2703 Avoid SPL relocation 2704 2705 CONFIG_SPL_NAND_BASE 2706 Include nand_base.c in the SPL. Requires 2707 CONFIG_SPL_NAND_DRIVERS. 2708 2709 CONFIG_SPL_NAND_DRIVERS 2710 SPL uses normal NAND drivers, not minimal drivers. 2711 2712 CONFIG_SPL_NAND_ECC 2713 Include standard software ECC in the SPL 2714 2715 CONFIG_SPL_NAND_SIMPLE 2716 Support for NAND boot using simple NAND drivers that 2717 expose the cmd_ctrl() interface. 2718 2719 CONFIG_SPL_UBI 2720 Support for a lightweight UBI (fastmap) scanner and 2721 loader 2722 2723 CONFIG_SPL_NAND_RAW_ONLY 2724 Support to boot only raw u-boot.bin images. Use this only 2725 if you need to save space. 2726 2727 CONFIG_SPL_COMMON_INIT_DDR 2728 Set for common ddr init with serial presence detect in 2729 SPL binary. 2730 2731 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2732 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2733 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2734 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2735 CONFIG_SYS_NAND_ECCBYTES 2736 Defines the size and behavior of the NAND that SPL uses 2737 to read U-Boot 2738 2739 CONFIG_SPL_NAND_BOOT 2740 Add support NAND boot 2741 2742 CONFIG_SYS_NAND_U_BOOT_OFFS 2743 Location in NAND to read U-Boot from 2744 2745 CONFIG_SYS_NAND_U_BOOT_DST 2746 Location in memory to load U-Boot to 2747 2748 CONFIG_SYS_NAND_U_BOOT_SIZE 2749 Size of image to load 2750 2751 CONFIG_SYS_NAND_U_BOOT_START 2752 Entry point in loaded image to jump to 2753 2754 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2755 Define this if you need to first read the OOB and then the 2756 data. This is used, for example, on davinci platforms. 2757 2758 CONFIG_SPL_RAM_DEVICE 2759 Support for running image already present in ram, in SPL binary 2760 2761 CONFIG_SPL_PAD_TO 2762 Image offset to which the SPL should be padded before appending 2763 the SPL payload. By default, this is defined as 2764 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2765 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2766 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2767 2768 CONFIG_SPL_TARGET 2769 Final target image containing SPL and payload. Some SPLs 2770 use an arch-specific makefile fragment instead, for 2771 example if more than one image needs to be produced. 2772 2773 CONFIG_FIT_SPL_PRINT 2774 Printing information about a FIT image adds quite a bit of 2775 code to SPL. So this is normally disabled in SPL. Use this 2776 option to re-enable it. This will affect the output of the 2777 bootm command when booting a FIT image. 2778 2779- TPL framework 2780 CONFIG_TPL 2781 Enable building of TPL globally. 2782 2783 CONFIG_TPL_PAD_TO 2784 Image offset to which the TPL should be padded before appending 2785 the TPL payload. By default, this is defined as 2786 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2787 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2788 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2789 2790- Interrupt support (PPC): 2791 2792 There are common interrupt_init() and timer_interrupt() 2793 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2794 for CPU specific initialization. interrupt_init_cpu() 2795 should set decrementer_count to appropriate value. If 2796 CPU resets decrementer automatically after interrupt 2797 (ppc4xx) it should set decrementer_count to zero. 2798 timer_interrupt() calls timer_interrupt_cpu() for CPU 2799 specific handling. If board has watchdog / status_led 2800 / other_activity_monitor it works automatically from 2801 general timer_interrupt(). 2802 2803 2804Board initialization settings: 2805------------------------------ 2806 2807During Initialization u-boot calls a number of board specific functions 2808to allow the preparation of board specific prerequisites, e.g. pin setup 2809before drivers are initialized. To enable these callbacks the 2810following configuration macros have to be defined. Currently this is 2811architecture specific, so please check arch/your_architecture/lib/board.c 2812typically in board_init_f() and board_init_r(). 2813 2814- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2815- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2816- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2817- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2818 2819Configuration Settings: 2820----------------------- 2821 2822- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2823 Optionally it can be defined to support 64-bit memory commands. 2824 2825- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2826 undefine this when you're short of memory. 2827 2828- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2829 width of the commands listed in the 'help' command output. 2830 2831- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2832 prompt for user input. 2833 2834- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2835 2836- CONFIG_SYS_PBSIZE: Buffer size for Console output 2837 2838- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2839 2840- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2841 the application (usually a Linux kernel) when it is 2842 booted 2843 2844- CONFIG_SYS_BAUDRATE_TABLE: 2845 List of legal baudrate settings for this board. 2846 2847- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2848 Begin and End addresses of the area used by the 2849 simple memory test. 2850 2851- CONFIG_SYS_ALT_MEMTEST: 2852 Enable an alternate, more extensive memory test. 2853 2854- CONFIG_SYS_MEMTEST_SCRATCH: 2855 Scratch address used by the alternate memory test 2856 You only need to set this if address zero isn't writeable 2857 2858- CONFIG_SYS_MEM_RESERVE_SECURE 2859 Only implemented for ARMv8 for now. 2860 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2861 is substracted from total RAM and won't be reported to OS. 2862 This memory can be used as secure memory. A variable 2863 gd->arch.secure_ram is used to track the location. In systems 2864 the RAM base is not zero, or RAM is divided into banks, 2865 this variable needs to be recalcuated to get the address. 2866 2867- CONFIG_SYS_MEM_TOP_HIDE: 2868 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2869 this specified memory area will get subtracted from the top 2870 (end) of RAM and won't get "touched" at all by U-Boot. By 2871 fixing up gd->ram_size the Linux kernel should gets passed 2872 the now "corrected" memory size and won't touch it either. 2873 This should work for arch/ppc and arch/powerpc. Only Linux 2874 board ports in arch/powerpc with bootwrapper support that 2875 recalculate the memory size from the SDRAM controller setup 2876 will have to get fixed in Linux additionally. 2877 2878 This option can be used as a workaround for the 440EPx/GRx 2879 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2880 be touched. 2881 2882 WARNING: Please make sure that this value is a multiple of 2883 the Linux page size (normally 4k). If this is not the case, 2884 then the end address of the Linux memory will be located at a 2885 non page size aligned address and this could cause major 2886 problems. 2887 2888- CONFIG_SYS_LOADS_BAUD_CHANGE: 2889 Enable temporary baudrate change while serial download 2890 2891- CONFIG_SYS_SDRAM_BASE: 2892 Physical start address of SDRAM. _Must_ be 0 here. 2893 2894- CONFIG_SYS_FLASH_BASE: 2895 Physical start address of Flash memory. 2896 2897- CONFIG_SYS_MONITOR_BASE: 2898 Physical start address of boot monitor code (set by 2899 make config files to be same as the text base address 2900 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2901 CONFIG_SYS_FLASH_BASE when booting from flash. 2902 2903- CONFIG_SYS_MONITOR_LEN: 2904 Size of memory reserved for monitor code, used to 2905 determine _at_compile_time_ (!) if the environment is 2906 embedded within the U-Boot image, or in a separate 2907 flash sector. 2908 2909- CONFIG_SYS_MALLOC_LEN: 2910 Size of DRAM reserved for malloc() use. 2911 2912- CONFIG_SYS_MALLOC_F_LEN 2913 Size of the malloc() pool for use before relocation. If 2914 this is defined, then a very simple malloc() implementation 2915 will become available before relocation. The address is just 2916 below the global data, and the stack is moved down to make 2917 space. 2918 2919 This feature allocates regions with increasing addresses 2920 within the region. calloc() is supported, but realloc() 2921 is not available. free() is supported but does nothing. 2922 The memory will be freed (or in fact just forgotten) when 2923 U-Boot relocates itself. 2924 2925- CONFIG_SYS_MALLOC_SIMPLE 2926 Provides a simple and small malloc() and calloc() for those 2927 boards which do not use the full malloc in SPL (which is 2928 enabled with CONFIG_SYS_SPL_MALLOC_START). 2929 2930- CONFIG_SYS_NONCACHED_MEMORY: 2931 Size of non-cached memory area. This area of memory will be 2932 typically located right below the malloc() area and mapped 2933 uncached in the MMU. This is useful for drivers that would 2934 otherwise require a lot of explicit cache maintenance. For 2935 some drivers it's also impossible to properly maintain the 2936 cache. For example if the regions that need to be flushed 2937 are not a multiple of the cache-line size, *and* padding 2938 cannot be allocated between the regions to align them (i.e. 2939 if the HW requires a contiguous array of regions, and the 2940 size of each region is not cache-aligned), then a flush of 2941 one region may result in overwriting data that hardware has 2942 written to another region in the same cache-line. This can 2943 happen for example in network drivers where descriptors for 2944 buffers are typically smaller than the CPU cache-line (e.g. 2945 16 bytes vs. 32 or 64 bytes). 2946 2947 Non-cached memory is only supported on 32-bit ARM at present. 2948 2949- CONFIG_SYS_BOOTM_LEN: 2950 Normally compressed uImages are limited to an 2951 uncompressed size of 8 MBytes. If this is not enough, 2952 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2953 to adjust this setting to your needs. 2954 2955- CONFIG_SYS_BOOTMAPSZ: 2956 Maximum size of memory mapped by the startup code of 2957 the Linux kernel; all data that must be processed by 2958 the Linux kernel (bd_info, boot arguments, FDT blob if 2959 used) must be put below this limit, unless "bootm_low" 2960 environment variable is defined and non-zero. In such case 2961 all data for the Linux kernel must be between "bootm_low" 2962 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2963 variable "bootm_mapsize" will override the value of 2964 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2965 then the value in "bootm_size" will be used instead. 2966 2967- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2968 Enable initrd_high functionality. If defined then the 2969 initrd_high feature is enabled and the bootm ramdisk subcommand 2970 is enabled. 2971 2972- CONFIG_SYS_BOOT_GET_CMDLINE: 2973 Enables allocating and saving kernel cmdline in space between 2974 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2975 2976- CONFIG_SYS_BOOT_GET_KBD: 2977 Enables allocating and saving a kernel copy of the bd_info in 2978 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2979 2980- CONFIG_SYS_MAX_FLASH_BANKS: 2981 Max number of Flash memory banks 2982 2983- CONFIG_SYS_MAX_FLASH_SECT: 2984 Max number of sectors on a Flash chip 2985 2986- CONFIG_SYS_FLASH_ERASE_TOUT: 2987 Timeout for Flash erase operations (in ms) 2988 2989- CONFIG_SYS_FLASH_WRITE_TOUT: 2990 Timeout for Flash write operations (in ms) 2991 2992- CONFIG_SYS_FLASH_LOCK_TOUT 2993 Timeout for Flash set sector lock bit operation (in ms) 2994 2995- CONFIG_SYS_FLASH_UNLOCK_TOUT 2996 Timeout for Flash clear lock bits operation (in ms) 2997 2998- CONFIG_SYS_FLASH_PROTECTION 2999 If defined, hardware flash sectors protection is used 3000 instead of U-Boot software protection. 3001 3002- CONFIG_SYS_DIRECT_FLASH_TFTP: 3003 3004 Enable TFTP transfers directly to flash memory; 3005 without this option such a download has to be 3006 performed in two steps: (1) download to RAM, and (2) 3007 copy from RAM to flash. 3008 3009 The two-step approach is usually more reliable, since 3010 you can check if the download worked before you erase 3011 the flash, but in some situations (when system RAM is 3012 too limited to allow for a temporary copy of the 3013 downloaded image) this option may be very useful. 3014 3015- CONFIG_SYS_FLASH_CFI: 3016 Define if the flash driver uses extra elements in the 3017 common flash structure for storing flash geometry. 3018 3019- CONFIG_FLASH_CFI_DRIVER 3020 This option also enables the building of the cfi_flash driver 3021 in the drivers directory 3022 3023- CONFIG_FLASH_CFI_MTD 3024 This option enables the building of the cfi_mtd driver 3025 in the drivers directory. The driver exports CFI flash 3026 to the MTD layer. 3027 3028- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 3029 Use buffered writes to flash. 3030 3031- CONFIG_FLASH_SPANSION_S29WS_N 3032 s29ws-n MirrorBit flash has non-standard addresses for buffered 3033 write commands. 3034 3035- CONFIG_SYS_FLASH_QUIET_TEST 3036 If this option is defined, the common CFI flash doesn't 3037 print it's warning upon not recognized FLASH banks. This 3038 is useful, if some of the configured banks are only 3039 optionally available. 3040 3041- CONFIG_FLASH_SHOW_PROGRESS 3042 If defined (must be an integer), print out countdown 3043 digits and dots. Recommended value: 45 (9..1) for 80 3044 column displays, 15 (3..1) for 40 column displays. 3045 3046- CONFIG_FLASH_VERIFY 3047 If defined, the content of the flash (destination) is compared 3048 against the source after the write operation. An error message 3049 will be printed when the contents are not identical. 3050 Please note that this option is useless in nearly all cases, 3051 since such flash programming errors usually are detected earlier 3052 while unprotecting/erasing/programming. Please only enable 3053 this option if you really know what you are doing. 3054 3055- CONFIG_SYS_RX_ETH_BUFFER: 3056 Defines the number of Ethernet receive buffers. On some 3057 Ethernet controllers it is recommended to set this value 3058 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3059 buffers can be full shortly after enabling the interface 3060 on high Ethernet traffic. 3061 Defaults to 4 if not defined. 3062 3063- CONFIG_ENV_MAX_ENTRIES 3064 3065 Maximum number of entries in the hash table that is used 3066 internally to store the environment settings. The default 3067 setting is supposed to be generous and should work in most 3068 cases. This setting can be used to tune behaviour; see 3069 lib/hashtable.c for details. 3070 3071- CONFIG_ENV_FLAGS_LIST_DEFAULT 3072- CONFIG_ENV_FLAGS_LIST_STATIC 3073 Enable validation of the values given to environment variables when 3074 calling env set. Variables can be restricted to only decimal, 3075 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3076 the variables can also be restricted to IP address or MAC address. 3077 3078 The format of the list is: 3079 type_attribute = [s|d|x|b|i|m] 3080 access_attribute = [a|r|o|c] 3081 attributes = type_attribute[access_attribute] 3082 entry = variable_name[:attributes] 3083 list = entry[,list] 3084 3085 The type attributes are: 3086 s - String (default) 3087 d - Decimal 3088 x - Hexadecimal 3089 b - Boolean ([1yYtT|0nNfF]) 3090 i - IP address 3091 m - MAC address 3092 3093 The access attributes are: 3094 a - Any (default) 3095 r - Read-only 3096 o - Write-once 3097 c - Change-default 3098 3099 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3100 Define this to a list (string) to define the ".flags" 3101 environment variable in the default or embedded environment. 3102 3103 - CONFIG_ENV_FLAGS_LIST_STATIC 3104 Define this to a list (string) to define validation that 3105 should be done if an entry is not found in the ".flags" 3106 environment variable. To override a setting in the static 3107 list, simply add an entry for the same variable name to the 3108 ".flags" variable. 3109 3110 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3111 regular expression. This allows multiple variables to define the same 3112 flags without explicitly listing them for each variable. 3113 3114- CONFIG_ENV_ACCESS_IGNORE_FORCE 3115 If defined, don't allow the -f switch to env set override variable 3116 access flags. 3117 3118- CONFIG_USE_STDINT 3119 If stdint.h is available with your toolchain you can define this 3120 option to enable it. You can provide option 'USE_STDINT=1' when 3121 building U-Boot to enable this. 3122 3123The following definitions that deal with the placement and management 3124of environment data (variable area); in general, we support the 3125following configurations: 3126 3127- CONFIG_BUILD_ENVCRC: 3128 3129 Builds up envcrc with the target environment so that external utils 3130 may easily extract it and embed it in final U-Boot images. 3131 3132BE CAREFUL! The first access to the environment happens quite early 3133in U-Boot initialization (when we try to get the setting of for the 3134console baudrate). You *MUST* have mapped your NVRAM area then, or 3135U-Boot will hang. 3136 3137Please note that even with NVRAM we still use a copy of the 3138environment in RAM: we could work on NVRAM directly, but we want to 3139keep settings there always unmodified except somebody uses "saveenv" 3140to save the current settings. 3141 3142BE CAREFUL! For some special cases, the local device can not use 3143"saveenv" command. For example, the local device will get the 3144environment stored in a remote NOR flash by SRIO or PCIE link, 3145but it can not erase, write this NOR flash by SRIO or PCIE interface. 3146 3147- CONFIG_NAND_ENV_DST 3148 3149 Defines address in RAM to which the nand_spl code should copy the 3150 environment. If redundant environment is used, it will be copied to 3151 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3152 3153Please note that the environment is read-only until the monitor 3154has been relocated to RAM and a RAM copy of the environment has been 3155created; also, when using EEPROM you will have to use env_get_f() 3156until then to read environment variables. 3157 3158The environment is protected by a CRC32 checksum. Before the monitor 3159is relocated into RAM, as a result of a bad CRC you will be working 3160with the compiled-in default environment - *silently*!!! [This is 3161necessary, because the first environment variable we need is the 3162"baudrate" setting for the console - if we have a bad CRC, we don't 3163have any device yet where we could complain.] 3164 3165Note: once the monitor has been relocated, then it will complain if 3166the default environment is used; a new CRC is computed as soon as you 3167use the "saveenv" command to store a valid environment. 3168 3169- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3170 Echo the inverted Ethernet link state to the fault LED. 3171 3172 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3173 also needs to be defined. 3174 3175- CONFIG_SYS_FAULT_MII_ADDR: 3176 MII address of the PHY to check for the Ethernet link state. 3177 3178- CONFIG_NS16550_MIN_FUNCTIONS: 3179 Define this if you desire to only have use of the NS16550_init 3180 and NS16550_putc functions for the serial driver located at 3181 drivers/serial/ns16550.c. This option is useful for saving 3182 space for already greatly restricted images, including but not 3183 limited to NAND_SPL configurations. 3184 3185- CONFIG_DISPLAY_BOARDINFO 3186 Display information about the board that U-Boot is running on 3187 when U-Boot starts up. The board function checkboard() is called 3188 to do this. 3189 3190- CONFIG_DISPLAY_BOARDINFO_LATE 3191 Similar to the previous option, but display this information 3192 later, once stdio is running and output goes to the LCD, if 3193 present. 3194 3195- CONFIG_BOARD_SIZE_LIMIT: 3196 Maximum size of the U-Boot image. When defined, the 3197 build system checks that the actual size does not 3198 exceed it. 3199 3200Low Level (hardware related) configuration options: 3201--------------------------------------------------- 3202 3203- CONFIG_SYS_CACHELINE_SIZE: 3204 Cache Line Size of the CPU. 3205 3206- CONFIG_SYS_CCSRBAR_DEFAULT: 3207 Default (power-on reset) physical address of CCSR on Freescale 3208 PowerPC SOCs. 3209 3210- CONFIG_SYS_CCSRBAR: 3211 Virtual address of CCSR. On a 32-bit build, this is typically 3212 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3213 3214- CONFIG_SYS_CCSRBAR_PHYS: 3215 Physical address of CCSR. CCSR can be relocated to a new 3216 physical address, if desired. In this case, this macro should 3217 be set to that address. Otherwise, it should be set to the 3218 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3219 is typically relocated on 36-bit builds. It is recommended 3220 that this macro be defined via the _HIGH and _LOW macros: 3221 3222 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3223 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3224 3225- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3226 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3227 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3228 used in assembly code, so it must not contain typecasts or 3229 integer size suffixes (e.g. "ULL"). 3230 3231- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3232 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3233 used in assembly code, so it must not contain typecasts or 3234 integer size suffixes (e.g. "ULL"). 3235 3236- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3237 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3238 forced to a value that ensures that CCSR is not relocated. 3239 3240- Floppy Disk Support: 3241 CONFIG_SYS_FDC_DRIVE_NUMBER 3242 3243 the default drive number (default value 0) 3244 3245 CONFIG_SYS_ISA_IO_STRIDE 3246 3247 defines the spacing between FDC chipset registers 3248 (default value 1) 3249 3250 CONFIG_SYS_ISA_IO_OFFSET 3251 3252 defines the offset of register from address. It 3253 depends on which part of the data bus is connected to 3254 the FDC chipset. (default value 0) 3255 3256 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3257 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3258 default value. 3259 3260 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3261 fdc_hw_init() is called at the beginning of the FDC 3262 setup. fdc_hw_init() must be provided by the board 3263 source code. It is used to make hardware-dependent 3264 initializations. 3265 3266- CONFIG_IDE_AHB: 3267 Most IDE controllers were designed to be connected with PCI 3268 interface. Only few of them were designed for AHB interface. 3269 When software is doing ATA command and data transfer to 3270 IDE devices through IDE-AHB controller, some additional 3271 registers accessing to these kind of IDE-AHB controller 3272 is required. 3273 3274- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3275 DO NOT CHANGE unless you know exactly what you're 3276 doing! (11-4) [MPC8xx systems only] 3277 3278- CONFIG_SYS_INIT_RAM_ADDR: 3279 3280 Start address of memory area that can be used for 3281 initial data and stack; please note that this must be 3282 writable memory that is working WITHOUT special 3283 initialization, i. e. you CANNOT use normal RAM which 3284 will become available only after programming the 3285 memory controller and running certain initialization 3286 sequences. 3287 3288 U-Boot uses the following memory types: 3289 - MPC8xx: IMMR (internal memory of the CPU) 3290 3291- CONFIG_SYS_GBL_DATA_OFFSET: 3292 3293 Offset of the initial data structure in the memory 3294 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3295 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3296 data is located at the end of the available space 3297 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3298 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3299 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3300 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3301 3302 Note: 3303 On the MPC824X (or other systems that use the data 3304 cache for initial memory) the address chosen for 3305 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3306 point to an otherwise UNUSED address space between 3307 the top of RAM and the start of the PCI space. 3308 3309- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3310 3311- CONFIG_SYS_OR_TIMING_SDRAM: 3312 SDRAM timing 3313 3314- CONFIG_SYS_MAMR_PTA: 3315 periodic timer for refresh 3316 3317- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3318 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3319 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3320 CONFIG_SYS_BR1_PRELIM: 3321 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3322 3323- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3324 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3325 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3326 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3327 3328- CONFIG_PCI_ENUM_ONLY 3329 Only scan through and get the devices on the buses. 3330 Don't do any setup work, presumably because someone or 3331 something has already done it, and we don't need to do it 3332 a second time. Useful for platforms that are pre-booted 3333 by coreboot or similar. 3334 3335- CONFIG_PCI_INDIRECT_BRIDGE: 3336 Enable support for indirect PCI bridges. 3337 3338- CONFIG_SYS_SRIO: 3339 Chip has SRIO or not 3340 3341- CONFIG_SRIO1: 3342 Board has SRIO 1 port available 3343 3344- CONFIG_SRIO2: 3345 Board has SRIO 2 port available 3346 3347- CONFIG_SRIO_PCIE_BOOT_MASTER 3348 Board can support master function for Boot from SRIO and PCIE 3349 3350- CONFIG_SYS_SRIOn_MEM_VIRT: 3351 Virtual Address of SRIO port 'n' memory region 3352 3353- CONFIG_SYS_SRIOn_MEM_PHYS: 3354 Physical Address of SRIO port 'n' memory region 3355 3356- CONFIG_SYS_SRIOn_MEM_SIZE: 3357 Size of SRIO port 'n' memory region 3358 3359- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3360 Defined to tell the NAND controller that the NAND chip is using 3361 a 16 bit bus. 3362 Not all NAND drivers use this symbol. 3363 Example of drivers that use it: 3364 - drivers/mtd/nand/ndfc.c 3365 - drivers/mtd/nand/mxc_nand.c 3366 3367- CONFIG_SYS_NDFC_EBC0_CFG 3368 Sets the EBC0_CFG register for the NDFC. If not defined 3369 a default value will be used. 3370 3371- CONFIG_SPD_EEPROM 3372 Get DDR timing information from an I2C EEPROM. Common 3373 with pluggable memory modules such as SODIMMs 3374 3375 SPD_EEPROM_ADDRESS 3376 I2C address of the SPD EEPROM 3377 3378- CONFIG_SYS_SPD_BUS_NUM 3379 If SPD EEPROM is on an I2C bus other than the first 3380 one, specify here. Note that the value must resolve 3381 to something your driver can deal with. 3382 3383- CONFIG_SYS_DDR_RAW_TIMING 3384 Get DDR timing information from other than SPD. Common with 3385 soldered DDR chips onboard without SPD. DDR raw timing 3386 parameters are extracted from datasheet and hard-coded into 3387 header files or board specific files. 3388 3389- CONFIG_FSL_DDR_INTERACTIVE 3390 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3391 3392- CONFIG_FSL_DDR_SYNC_REFRESH 3393 Enable sync of refresh for multiple controllers. 3394 3395- CONFIG_FSL_DDR_BIST 3396 Enable built-in memory test for Freescale DDR controllers. 3397 3398- CONFIG_SYS_83XX_DDR_USES_CS0 3399 Only for 83xx systems. If specified, then DDR should 3400 be configured using CS0 and CS1 instead of CS2 and CS3. 3401 3402- CONFIG_RMII 3403 Enable RMII mode for all FECs. 3404 Note that this is a global option, we can't 3405 have one FEC in standard MII mode and another in RMII mode. 3406 3407- CONFIG_CRC32_VERIFY 3408 Add a verify option to the crc32 command. 3409 The syntax is: 3410 3411 => crc32 -v <address> <count> <crc32> 3412 3413 Where address/count indicate a memory area 3414 and crc32 is the correct crc32 which the 3415 area should have. 3416 3417- CONFIG_LOOPW 3418 Add the "loopw" memory command. This only takes effect if 3419 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3420 3421- CONFIG_MX_CYCLIC 3422 Add the "mdc" and "mwc" memory commands. These are cyclic 3423 "md/mw" commands. 3424 Examples: 3425 3426 => mdc.b 10 4 500 3427 This command will print 4 bytes (10,11,12,13) each 500 ms. 3428 3429 => mwc.l 100 12345678 10 3430 This command will write 12345678 to address 100 all 10 ms. 3431 3432 This only takes effect if the memory commands are activated 3433 globally (CONFIG_CMD_MEMORY). 3434 3435- CONFIG_SKIP_LOWLEVEL_INIT 3436 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3437 low level initializations (like setting up the memory 3438 controller) are omitted and/or U-Boot does not 3439 relocate itself into RAM. 3440 3441 Normally this variable MUST NOT be defined. The only 3442 exception is when U-Boot is loaded (to RAM) by some 3443 other boot loader or by a debugger which performs 3444 these initializations itself. 3445 3446- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3447 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3448 to be skipped. The normal CP15 init (such as enabling the 3449 instruction cache) is still performed. 3450 3451- CONFIG_SPL_BUILD 3452 Modifies the behaviour of start.S when compiling a loader 3453 that is executed before the actual U-Boot. E.g. when 3454 compiling a NAND SPL. 3455 3456- CONFIG_TPL_BUILD 3457 Modifies the behaviour of start.S when compiling a loader 3458 that is executed after the SPL and before the actual U-Boot. 3459 It is loaded by the SPL. 3460 3461- CONFIG_SYS_MPC85XX_NO_RESETVEC 3462 Only for 85xx systems. If this variable is specified, the section 3463 .resetvec is not kept and the section .bootpg is placed in the 3464 previous 4k of the .text section. 3465 3466- CONFIG_ARCH_MAP_SYSMEM 3467 Generally U-Boot (and in particular the md command) uses 3468 effective address. It is therefore not necessary to regard 3469 U-Boot address as virtual addresses that need to be translated 3470 to physical addresses. However, sandbox requires this, since 3471 it maintains its own little RAM buffer which contains all 3472 addressable memory. This option causes some memory accesses 3473 to be mapped through map_sysmem() / unmap_sysmem(). 3474 3475- CONFIG_X86_RESET_VECTOR 3476 If defined, the x86 reset vector code is included. This is not 3477 needed when U-Boot is running from Coreboot. 3478 3479- CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC: 3480 Enables the RTC32K OSC on AM33xx based plattforms 3481 3482- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3483 Option to disable subpage write in NAND driver 3484 driver that uses this: 3485 drivers/mtd/nand/davinci_nand.c 3486 3487Freescale QE/FMAN Firmware Support: 3488----------------------------------- 3489 3490The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3491loading of "firmware", which is encoded in the QE firmware binary format. 3492This firmware often needs to be loaded during U-Boot booting, so macros 3493are used to identify the storage device (NOR flash, SPI, etc) and the address 3494within that device. 3495 3496- CONFIG_SYS_FMAN_FW_ADDR 3497 The address in the storage device where the FMAN microcode is located. The 3498 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3499 is also specified. 3500 3501- CONFIG_SYS_QE_FW_ADDR 3502 The address in the storage device where the QE microcode is located. The 3503 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3504 is also specified. 3505 3506- CONFIG_SYS_QE_FMAN_FW_LENGTH 3507 The maximum possible size of the firmware. The firmware binary format 3508 has a field that specifies the actual size of the firmware, but it 3509 might not be possible to read any part of the firmware unless some 3510 local storage is allocated to hold the entire firmware first. 3511 3512- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3513 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3514 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3515 virtual address in NOR flash. 3516 3517- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3518 Specifies that QE/FMAN firmware is located in NAND flash. 3519 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3520 3521- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3522 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3523 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3524 3525- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3526 Specifies that QE/FMAN firmware is located in the remote (master) 3527 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3528 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3529 window->master inbound window->master LAW->the ucode address in 3530 master's memory space. 3531 3532Freescale Layerscape Management Complex Firmware Support: 3533--------------------------------------------------------- 3534The Freescale Layerscape Management Complex (MC) supports the loading of 3535"firmware". 3536This firmware often needs to be loaded during U-Boot booting, so macros 3537are used to identify the storage device (NOR flash, SPI, etc) and the address 3538within that device. 3539 3540- CONFIG_FSL_MC_ENET 3541 Enable the MC driver for Layerscape SoCs. 3542 3543Freescale Layerscape Debug Server Support: 3544------------------------------------------- 3545The Freescale Layerscape Debug Server Support supports the loading of 3546"Debug Server firmware" and triggering SP boot-rom. 3547This firmware often needs to be loaded during U-Boot booting. 3548 3549- CONFIG_SYS_MC_RSV_MEM_ALIGN 3550 Define alignment of reserved memory MC requires 3551 3552Reproducible builds 3553------------------- 3554 3555In order to achieve reproducible builds, timestamps used in the U-Boot build 3556process have to be set to a fixed value. 3557 3558This is done using the SOURCE_DATE_EPOCH environment variable. 3559SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3560option for U-Boot or an environment variable in U-Boot. 3561 3562SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3563 3564Building the Software: 3565====================== 3566 3567Building U-Boot has been tested in several native build environments 3568and in many different cross environments. Of course we cannot support 3569all possibly existing versions of cross development tools in all 3570(potentially obsolete) versions. In case of tool chain problems we 3571recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3572which is extensively used to build and test U-Boot. 3573 3574If you are not using a native environment, it is assumed that you 3575have GNU cross compiling tools available in your path. In this case, 3576you must set the environment variable CROSS_COMPILE in your shell. 3577Note that no changes to the Makefile or any other source files are 3578necessary. For example using the ELDK on a 4xx CPU, please enter: 3579 3580 $ CROSS_COMPILE=ppc_4xx- 3581 $ export CROSS_COMPILE 3582 3583Note: If you wish to generate Windows versions of the utilities in 3584 the tools directory you can use the MinGW toolchain 3585 (http://www.mingw.org). Set your HOST tools to the MinGW 3586 toolchain and execute 'make tools'. For example: 3587 3588 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3589 3590 Binaries such as tools/mkimage.exe will be created which can 3591 be executed on computers running Windows. 3592 3593U-Boot is intended to be simple to build. After installing the 3594sources you must configure U-Boot for one specific board type. This 3595is done by typing: 3596 3597 make NAME_defconfig 3598 3599where "NAME_defconfig" is the name of one of the existing configu- 3600rations; see boards.cfg for supported names. 3601 3602Note: for some board special configuration names may exist; check if 3603 additional information is available from the board vendor; for 3604 instance, the TQM823L systems are available without (standard) 3605 or with LCD support. You can select such additional "features" 3606 when choosing the configuration, i. e. 3607 3608 make TQM823L_defconfig 3609 - will configure for a plain TQM823L, i. e. no LCD support 3610 3611 make TQM823L_LCD_defconfig 3612 - will configure for a TQM823L with U-Boot console on LCD 3613 3614 etc. 3615 3616 3617Finally, type "make all", and you should get some working U-Boot 3618images ready for download to / installation on your system: 3619 3620- "u-boot.bin" is a raw binary image 3621- "u-boot" is an image in ELF binary format 3622- "u-boot.srec" is in Motorola S-Record format 3623 3624By default the build is performed locally and the objects are saved 3625in the source directory. One of the two methods can be used to change 3626this behavior and build U-Boot to some external directory: 3627 36281. Add O= to the make command line invocations: 3629 3630 make O=/tmp/build distclean 3631 make O=/tmp/build NAME_defconfig 3632 make O=/tmp/build all 3633 36342. Set environment variable KBUILD_OUTPUT to point to the desired location: 3635 3636 export KBUILD_OUTPUT=/tmp/build 3637 make distclean 3638 make NAME_defconfig 3639 make all 3640 3641Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3642variable. 3643 3644User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3645setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3646For example to treat all compiler warnings as errors: 3647 3648 make KCFLAGS=-Werror 3649 3650Please be aware that the Makefiles assume you are using GNU make, so 3651for instance on NetBSD you might need to use "gmake" instead of 3652native "make". 3653 3654 3655If the system board that you have is not listed, then you will need 3656to port U-Boot to your hardware platform. To do this, follow these 3657steps: 3658 36591. Create a new directory to hold your board specific code. Add any 3660 files you need. In your board directory, you will need at least 3661 the "Makefile" and a "<board>.c". 36622. Create a new configuration file "include/configs/<board>.h" for 3663 your board. 36643. If you're porting U-Boot to a new CPU, then also create a new 3665 directory to hold your CPU specific code. Add any files you need. 36664. Run "make <board>_defconfig" with your new name. 36675. Type "make", and you should get a working "u-boot.srec" file 3668 to be installed on your target system. 36696. Debug and solve any problems that might arise. 3670 [Of course, this last step is much harder than it sounds.] 3671 3672 3673Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3674============================================================== 3675 3676If you have modified U-Boot sources (for instance added a new board 3677or support for new devices, a new CPU, etc.) you are expected to 3678provide feedback to the other developers. The feedback normally takes 3679the form of a "patch", i. e. a context diff against a certain (latest 3680official or latest in the git repository) version of U-Boot sources. 3681 3682But before you submit such a patch, please verify that your modifi- 3683cation did not break existing code. At least make sure that *ALL* of 3684the supported boards compile WITHOUT ANY compiler warnings. To do so, 3685just run the buildman script (tools/buildman/buildman), which will 3686configure and build U-Boot for ALL supported system. Be warned, this 3687will take a while. Please see the buildman README, or run 'buildman -H' 3688for documentation. 3689 3690 3691See also "U-Boot Porting Guide" below. 3692 3693 3694Monitor Commands - Overview: 3695============================ 3696 3697go - start application at address 'addr' 3698run - run commands in an environment variable 3699bootm - boot application image from memory 3700bootp - boot image via network using BootP/TFTP protocol 3701bootz - boot zImage from memory 3702tftpboot- boot image via network using TFTP protocol 3703 and env variables "ipaddr" and "serverip" 3704 (and eventually "gatewayip") 3705tftpput - upload a file via network using TFTP protocol 3706rarpboot- boot image via network using RARP/TFTP protocol 3707diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3708loads - load S-Record file over serial line 3709loadb - load binary file over serial line (kermit mode) 3710md - memory display 3711mm - memory modify (auto-incrementing) 3712nm - memory modify (constant address) 3713mw - memory write (fill) 3714cp - memory copy 3715cmp - memory compare 3716crc32 - checksum calculation 3717i2c - I2C sub-system 3718sspi - SPI utility commands 3719base - print or set address offset 3720printenv- print environment variables 3721setenv - set environment variables 3722saveenv - save environment variables to persistent storage 3723protect - enable or disable FLASH write protection 3724erase - erase FLASH memory 3725flinfo - print FLASH memory information 3726nand - NAND memory operations (see doc/README.nand) 3727bdinfo - print Board Info structure 3728iminfo - print header information for application image 3729coninfo - print console devices and informations 3730ide - IDE sub-system 3731loop - infinite loop on address range 3732loopw - infinite write loop on address range 3733mtest - simple RAM test 3734icache - enable or disable instruction cache 3735dcache - enable or disable data cache 3736reset - Perform RESET of the CPU 3737echo - echo args to console 3738version - print monitor version 3739help - print online help 3740? - alias for 'help' 3741 3742 3743Monitor Commands - Detailed Description: 3744======================================== 3745 3746TODO. 3747 3748For now: just type "help <command>". 3749 3750 3751Environment Variables: 3752====================== 3753 3754U-Boot supports user configuration using Environment Variables which 3755can be made persistent by saving to Flash memory. 3756 3757Environment Variables are set using "setenv", printed using 3758"printenv", and saved to Flash using "saveenv". Using "setenv" 3759without a value can be used to delete a variable from the 3760environment. As long as you don't save the environment you are 3761working with an in-memory copy. In case the Flash area containing the 3762environment is erased by accident, a default environment is provided. 3763 3764Some configuration options can be set using Environment Variables. 3765 3766List of environment variables (most likely not complete): 3767 3768 baudrate - see CONFIG_BAUDRATE 3769 3770 bootdelay - see CONFIG_BOOTDELAY 3771 3772 bootcmd - see CONFIG_BOOTCOMMAND 3773 3774 bootargs - Boot arguments when booting an RTOS image 3775 3776 bootfile - Name of the image to load with TFTP 3777 3778 bootm_low - Memory range available for image processing in the bootm 3779 command can be restricted. This variable is given as 3780 a hexadecimal number and defines lowest address allowed 3781 for use by the bootm command. See also "bootm_size" 3782 environment variable. Address defined by "bootm_low" is 3783 also the base of the initial memory mapping for the Linux 3784 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3785 bootm_mapsize. 3786 3787 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3788 This variable is given as a hexadecimal number and it 3789 defines the size of the memory region starting at base 3790 address bootm_low that is accessible by the Linux kernel 3791 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3792 as the default value if it is defined, and bootm_size is 3793 used otherwise. 3794 3795 bootm_size - Memory range available for image processing in the bootm 3796 command can be restricted. This variable is given as 3797 a hexadecimal number and defines the size of the region 3798 allowed for use by the bootm command. See also "bootm_low" 3799 environment variable. 3800 3801 updatefile - Location of the software update file on a TFTP server, used 3802 by the automatic software update feature. Please refer to 3803 documentation in doc/README.update for more details. 3804 3805 autoload - if set to "no" (any string beginning with 'n'), 3806 "bootp" will just load perform a lookup of the 3807 configuration from the BOOTP server, but not try to 3808 load any image using TFTP 3809 3810 autostart - if set to "yes", an image loaded using the "bootp", 3811 "rarpboot", "tftpboot" or "diskboot" commands will 3812 be automatically started (by internally calling 3813 "bootm") 3814 3815 If set to "no", a standalone image passed to the 3816 "bootm" command will be copied to the load address 3817 (and eventually uncompressed), but NOT be started. 3818 This can be used to load and uncompress arbitrary 3819 data. 3820 3821 fdt_high - if set this restricts the maximum address that the 3822 flattened device tree will be copied into upon boot. 3823 For example, if you have a system with 1 GB memory 3824 at physical address 0x10000000, while Linux kernel 3825 only recognizes the first 704 MB as low memory, you 3826 may need to set fdt_high as 0x3C000000 to have the 3827 device tree blob be copied to the maximum address 3828 of the 704 MB low memory, so that Linux kernel can 3829 access it during the boot procedure. 3830 3831 If this is set to the special value 0xFFFFFFFF then 3832 the fdt will not be copied at all on boot. For this 3833 to work it must reside in writable memory, have 3834 sufficient padding on the end of it for u-boot to 3835 add the information it needs into it, and the memory 3836 must be accessible by the kernel. 3837 3838 fdtcontroladdr- if set this is the address of the control flattened 3839 device tree used by U-Boot when CONFIG_OF_CONTROL is 3840 defined. 3841 3842 i2cfast - (PPC405GP|PPC405EP only) 3843 if set to 'y' configures Linux I2C driver for fast 3844 mode (400kHZ). This environment variable is used in 3845 initialization code. So, for changes to be effective 3846 it must be saved and board must be reset. 3847 3848 initrd_high - restrict positioning of initrd images: 3849 If this variable is not set, initrd images will be 3850 copied to the highest possible address in RAM; this 3851 is usually what you want since it allows for 3852 maximum initrd size. If for some reason you want to 3853 make sure that the initrd image is loaded below the 3854 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3855 variable to a value of "no" or "off" or "0". 3856 Alternatively, you can set it to a maximum upper 3857 address to use (U-Boot will still check that it 3858 does not overwrite the U-Boot stack and data). 3859 3860 For instance, when you have a system with 16 MB 3861 RAM, and want to reserve 4 MB from use by Linux, 3862 you can do this by adding "mem=12M" to the value of 3863 the "bootargs" variable. However, now you must make 3864 sure that the initrd image is placed in the first 3865 12 MB as well - this can be done with 3866 3867 setenv initrd_high 00c00000 3868 3869 If you set initrd_high to 0xFFFFFFFF, this is an 3870 indication to U-Boot that all addresses are legal 3871 for the Linux kernel, including addresses in flash 3872 memory. In this case U-Boot will NOT COPY the 3873 ramdisk at all. This may be useful to reduce the 3874 boot time on your system, but requires that this 3875 feature is supported by your Linux kernel. 3876 3877 ipaddr - IP address; needed for tftpboot command 3878 3879 loadaddr - Default load address for commands like "bootp", 3880 "rarpboot", "tftpboot", "loadb" or "diskboot" 3881 3882 loads_echo - see CONFIG_LOADS_ECHO 3883 3884 serverip - TFTP server IP address; needed for tftpboot command 3885 3886 bootretry - see CONFIG_BOOT_RETRY_TIME 3887 3888 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3889 3890 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3891 3892 ethprime - controls which interface is used first. 3893 3894 ethact - controls which interface is currently active. 3895 For example you can do the following 3896 3897 => setenv ethact FEC 3898 => ping 192.168.0.1 # traffic sent on FEC 3899 => setenv ethact SCC 3900 => ping 10.0.0.1 # traffic sent on SCC 3901 3902 ethrotate - When set to "no" U-Boot does not go through all 3903 available network interfaces. 3904 It just stays at the currently selected interface. 3905 3906 netretry - When set to "no" each network operation will 3907 either succeed or fail without retrying. 3908 When set to "once" the network operation will 3909 fail when all the available network interfaces 3910 are tried once without success. 3911 Useful on scripts which control the retry operation 3912 themselves. 3913 3914 npe_ucode - set load address for the NPE microcode 3915 3916 silent_linux - If set then Linux will be told to boot silently, by 3917 changing the console to be empty. If "yes" it will be 3918 made silent. If "no" it will not be made silent. If 3919 unset, then it will be made silent if the U-Boot console 3920 is silent. 3921 3922 tftpsrcp - If this is set, the value is used for TFTP's 3923 UDP source port. 3924 3925 tftpdstp - If this is set, the value is used for TFTP's UDP 3926 destination port instead of the Well Know Port 69. 3927 3928 tftpblocksize - Block size to use for TFTP transfers; if not set, 3929 we use the TFTP server's default block size 3930 3931 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3932 seconds, minimum value is 1000 = 1 second). Defines 3933 when a packet is considered to be lost so it has to 3934 be retransmitted. The default is 5000 = 5 seconds. 3935 Lowering this value may make downloads succeed 3936 faster in networks with high packet loss rates or 3937 with unreliable TFTP servers. 3938 3939 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3940 unit, minimum value = 0). Defines how many timeouts 3941 can happen during a single file transfer before that 3942 transfer is aborted. The default is 10, and 0 means 3943 'no timeouts allowed'. Increasing this value may help 3944 downloads succeed with high packet loss rates, or with 3945 unreliable TFTP servers or client hardware. 3946 3947 vlan - When set to a value < 4095 the traffic over 3948 Ethernet is encapsulated/received over 802.1q 3949 VLAN tagged frames. 3950 3951 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3952 Unsigned value, in milliseconds. If not set, the period will 3953 be either the default (28000), or a value based on 3954 CONFIG_NET_RETRY_COUNT, if defined. This value has 3955 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3956 3957The following image location variables contain the location of images 3958used in booting. The "Image" column gives the role of the image and is 3959not an environment variable name. The other columns are environment 3960variable names. "File Name" gives the name of the file on a TFTP 3961server, "RAM Address" gives the location in RAM the image will be 3962loaded to, and "Flash Location" gives the image's address in NOR 3963flash or offset in NAND flash. 3964 3965*Note* - these variables don't have to be defined for all boards, some 3966boards currently use other variables for these purposes, and some 3967boards use these variables for other purposes. 3968 3969Image File Name RAM Address Flash Location 3970----- --------- ----------- -------------- 3971u-boot u-boot u-boot_addr_r u-boot_addr 3972Linux kernel bootfile kernel_addr_r kernel_addr 3973device tree blob fdtfile fdt_addr_r fdt_addr 3974ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3975 3976The following environment variables may be used and automatically 3977updated by the network boot commands ("bootp" and "rarpboot"), 3978depending the information provided by your boot server: 3979 3980 bootfile - see above 3981 dnsip - IP address of your Domain Name Server 3982 dnsip2 - IP address of your secondary Domain Name Server 3983 gatewayip - IP address of the Gateway (Router) to use 3984 hostname - Target hostname 3985 ipaddr - see above 3986 netmask - Subnet Mask 3987 rootpath - Pathname of the root filesystem on the NFS server 3988 serverip - see above 3989 3990 3991There are two special Environment Variables: 3992 3993 serial# - contains hardware identification information such 3994 as type string and/or serial number 3995 ethaddr - Ethernet address 3996 3997These variables can be set only once (usually during manufacturing of 3998the board). U-Boot refuses to delete or overwrite these variables 3999once they have been set once. 4000 4001 4002Further special Environment Variables: 4003 4004 ver - Contains the U-Boot version string as printed 4005 with the "version" command. This variable is 4006 readonly (see CONFIG_VERSION_VARIABLE). 4007 4008 4009Please note that changes to some configuration parameters may take 4010only effect after the next boot (yes, that's just like Windoze :-). 4011 4012 4013Callback functions for environment variables: 4014--------------------------------------------- 4015 4016For some environment variables, the behavior of u-boot needs to change 4017when their values are changed. This functionality allows functions to 4018be associated with arbitrary variables. On creation, overwrite, or 4019deletion, the callback will provide the opportunity for some side 4020effect to happen or for the change to be rejected. 4021 4022The callbacks are named and associated with a function using the 4023U_BOOT_ENV_CALLBACK macro in your board or driver code. 4024 4025These callbacks are associated with variables in one of two ways. The 4026static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 4027in the board configuration to a string that defines a list of 4028associations. The list must be in the following format: 4029 4030 entry = variable_name[:callback_name] 4031 list = entry[,list] 4032 4033If the callback name is not specified, then the callback is deleted. 4034Spaces are also allowed anywhere in the list. 4035 4036Callbacks can also be associated by defining the ".callbacks" variable 4037with the same list format above. Any association in ".callbacks" will 4038override any association in the static list. You can define 4039CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 4040".callbacks" environment variable in the default or embedded environment. 4041 4042If CONFIG_REGEX is defined, the variable_name above is evaluated as a 4043regular expression. This allows multiple variables to be connected to 4044the same callback without explicitly listing them all out. 4045 4046 4047Command Line Parsing: 4048===================== 4049 4050There are two different command line parsers available with U-Boot: 4051the old "simple" one, and the much more powerful "hush" shell: 4052 4053Old, simple command line parser: 4054-------------------------------- 4055 4056- supports environment variables (through setenv / saveenv commands) 4057- several commands on one line, separated by ';' 4058- variable substitution using "... ${name} ..." syntax 4059- special characters ('$', ';') can be escaped by prefixing with '\', 4060 for example: 4061 setenv bootcmd bootm \${address} 4062- You can also escape text by enclosing in single apostrophes, for example: 4063 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4064 4065Hush shell: 4066----------- 4067 4068- similar to Bourne shell, with control structures like 4069 if...then...else...fi, for...do...done; while...do...done, 4070 until...do...done, ... 4071- supports environment ("global") variables (through setenv / saveenv 4072 commands) and local shell variables (through standard shell syntax 4073 "name=value"); only environment variables can be used with "run" 4074 command 4075 4076General rules: 4077-------------- 4078 4079(1) If a command line (or an environment variable executed by a "run" 4080 command) contains several commands separated by semicolon, and 4081 one of these commands fails, then the remaining commands will be 4082 executed anyway. 4083 4084(2) If you execute several variables with one call to run (i. e. 4085 calling run with a list of variables as arguments), any failing 4086 command will cause "run" to terminate, i. e. the remaining 4087 variables are not executed. 4088 4089Note for Redundant Ethernet Interfaces: 4090======================================= 4091 4092Some boards come with redundant Ethernet interfaces; U-Boot supports 4093such configurations and is capable of automatic selection of a 4094"working" interface when needed. MAC assignment works as follows: 4095 4096Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4097MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4098"eth1addr" (=>eth1), "eth2addr", ... 4099 4100If the network interface stores some valid MAC address (for instance 4101in SROM), this is used as default address if there is NO correspon- 4102ding setting in the environment; if the corresponding environment 4103variable is set, this overrides the settings in the card; that means: 4104 4105o If the SROM has a valid MAC address, and there is no address in the 4106 environment, the SROM's address is used. 4107 4108o If there is no valid address in the SROM, and a definition in the 4109 environment exists, then the value from the environment variable is 4110 used. 4111 4112o If both the SROM and the environment contain a MAC address, and 4113 both addresses are the same, this MAC address is used. 4114 4115o If both the SROM and the environment contain a MAC address, and the 4116 addresses differ, the value from the environment is used and a 4117 warning is printed. 4118 4119o If neither SROM nor the environment contain a MAC address, an error 4120 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4121 a random, locally-assigned MAC is used. 4122 4123If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4124will be programmed into hardware as part of the initialization process. This 4125may be skipped by setting the appropriate 'ethmacskip' environment variable. 4126The naming convention is as follows: 4127"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4128 4129Image Formats: 4130============== 4131 4132U-Boot is capable of booting (and performing other auxiliary operations on) 4133images in two formats: 4134 4135New uImage format (FIT) 4136----------------------- 4137 4138Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4139to Flattened Device Tree). It allows the use of images with multiple 4140components (several kernels, ramdisks, etc.), with contents protected by 4141SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4142 4143 4144Old uImage format 4145----------------- 4146 4147Old image format is based on binary files which can be basically anything, 4148preceded by a special header; see the definitions in include/image.h for 4149details; basically, the header defines the following image properties: 4150 4151* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4152 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4153 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4154 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4155 INTEGRITY). 4156* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4157 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4158 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4159* Compression Type (uncompressed, gzip, bzip2) 4160* Load Address 4161* Entry Point 4162* Image Name 4163* Image Timestamp 4164 4165The header is marked by a special Magic Number, and both the header 4166and the data portions of the image are secured against corruption by 4167CRC32 checksums. 4168 4169 4170Linux Support: 4171============== 4172 4173Although U-Boot should support any OS or standalone application 4174easily, the main focus has always been on Linux during the design of 4175U-Boot. 4176 4177U-Boot includes many features that so far have been part of some 4178special "boot loader" code within the Linux kernel. Also, any 4179"initrd" images to be used are no longer part of one big Linux image; 4180instead, kernel and "initrd" are separate images. This implementation 4181serves several purposes: 4182 4183- the same features can be used for other OS or standalone 4184 applications (for instance: using compressed images to reduce the 4185 Flash memory footprint) 4186 4187- it becomes much easier to port new Linux kernel versions because 4188 lots of low-level, hardware dependent stuff are done by U-Boot 4189 4190- the same Linux kernel image can now be used with different "initrd" 4191 images; of course this also means that different kernel images can 4192 be run with the same "initrd". This makes testing easier (you don't 4193 have to build a new "zImage.initrd" Linux image when you just 4194 change a file in your "initrd"). Also, a field-upgrade of the 4195 software is easier now. 4196 4197 4198Linux HOWTO: 4199============ 4200 4201Porting Linux to U-Boot based systems: 4202--------------------------------------- 4203 4204U-Boot cannot save you from doing all the necessary modifications to 4205configure the Linux device drivers for use with your target hardware 4206(no, we don't intend to provide a full virtual machine interface to 4207Linux :-). 4208 4209But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4210 4211Just make sure your machine specific header file (for instance 4212include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4213Information structure as we define in include/asm-<arch>/u-boot.h, 4214and make sure that your definition of IMAP_ADDR uses the same value 4215as your U-Boot configuration in CONFIG_SYS_IMMR. 4216 4217Note that U-Boot now has a driver model, a unified model for drivers. 4218If you are adding a new driver, plumb it into driver model. If there 4219is no uclass available, you are encouraged to create one. See 4220doc/driver-model. 4221 4222 4223Configuring the Linux kernel: 4224----------------------------- 4225 4226No specific requirements for U-Boot. Make sure you have some root 4227device (initial ramdisk, NFS) for your target system. 4228 4229 4230Building a Linux Image: 4231----------------------- 4232 4233With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4234not used. If you use recent kernel source, a new build target 4235"uImage" will exist which automatically builds an image usable by 4236U-Boot. Most older kernels also have support for a "pImage" target, 4237which was introduced for our predecessor project PPCBoot and uses a 4238100% compatible format. 4239 4240Example: 4241 4242 make TQM850L_defconfig 4243 make oldconfig 4244 make dep 4245 make uImage 4246 4247The "uImage" build target uses a special tool (in 'tools/mkimage') to 4248encapsulate a compressed Linux kernel image with header information, 4249CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4250 4251* build a standard "vmlinux" kernel image (in ELF binary format): 4252 4253* convert the kernel into a raw binary image: 4254 4255 ${CROSS_COMPILE}-objcopy -O binary \ 4256 -R .note -R .comment \ 4257 -S vmlinux linux.bin 4258 4259* compress the binary image: 4260 4261 gzip -9 linux.bin 4262 4263* package compressed binary image for U-Boot: 4264 4265 mkimage -A ppc -O linux -T kernel -C gzip \ 4266 -a 0 -e 0 -n "Linux Kernel Image" \ 4267 -d linux.bin.gz uImage 4268 4269 4270The "mkimage" tool can also be used to create ramdisk images for use 4271with U-Boot, either separated from the Linux kernel image, or 4272combined into one file. "mkimage" encapsulates the images with a 64 4273byte header containing information about target architecture, 4274operating system, image type, compression method, entry points, time 4275stamp, CRC32 checksums, etc. 4276 4277"mkimage" can be called in two ways: to verify existing images and 4278print the header information, or to build new images. 4279 4280In the first form (with "-l" option) mkimage lists the information 4281contained in the header of an existing U-Boot image; this includes 4282checksum verification: 4283 4284 tools/mkimage -l image 4285 -l ==> list image header information 4286 4287The second form (with "-d" option) is used to build a U-Boot image 4288from a "data file" which is used as image payload: 4289 4290 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4291 -n name -d data_file image 4292 -A ==> set architecture to 'arch' 4293 -O ==> set operating system to 'os' 4294 -T ==> set image type to 'type' 4295 -C ==> set compression type 'comp' 4296 -a ==> set load address to 'addr' (hex) 4297 -e ==> set entry point to 'ep' (hex) 4298 -n ==> set image name to 'name' 4299 -d ==> use image data from 'datafile' 4300 4301Right now, all Linux kernels for PowerPC systems use the same load 4302address (0x00000000), but the entry point address depends on the 4303kernel version: 4304 4305- 2.2.x kernels have the entry point at 0x0000000C, 4306- 2.3.x and later kernels have the entry point at 0x00000000. 4307 4308So a typical call to build a U-Boot image would read: 4309 4310 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4311 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4312 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4313 > examples/uImage.TQM850L 4314 Image Name: 2.4.4 kernel for TQM850L 4315 Created: Wed Jul 19 02:34:59 2000 4316 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4317 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4318 Load Address: 0x00000000 4319 Entry Point: 0x00000000 4320 4321To verify the contents of the image (or check for corruption): 4322 4323 -> tools/mkimage -l examples/uImage.TQM850L 4324 Image Name: 2.4.4 kernel for TQM850L 4325 Created: Wed Jul 19 02:34:59 2000 4326 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4327 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4328 Load Address: 0x00000000 4329 Entry Point: 0x00000000 4330 4331NOTE: for embedded systems where boot time is critical you can trade 4332speed for memory and install an UNCOMPRESSED image instead: this 4333needs more space in Flash, but boots much faster since it does not 4334need to be uncompressed: 4335 4336 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4337 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4338 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4339 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4340 > examples/uImage.TQM850L-uncompressed 4341 Image Name: 2.4.4 kernel for TQM850L 4342 Created: Wed Jul 19 02:34:59 2000 4343 Image Type: PowerPC Linux Kernel Image (uncompressed) 4344 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4345 Load Address: 0x00000000 4346 Entry Point: 0x00000000 4347 4348 4349Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4350when your kernel is intended to use an initial ramdisk: 4351 4352 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4353 > -A ppc -O linux -T ramdisk -C gzip \ 4354 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4355 Image Name: Simple Ramdisk Image 4356 Created: Wed Jan 12 14:01:50 2000 4357 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4358 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4359 Load Address: 0x00000000 4360 Entry Point: 0x00000000 4361 4362The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4363option performs the converse operation of the mkimage's second form (the "-d" 4364option). Given an image built by mkimage, the dumpimage extracts a "data file" 4365from the image: 4366 4367 tools/dumpimage -i image -T type -p position data_file 4368 -i ==> extract from the 'image' a specific 'data_file' 4369 -T ==> set image type to 'type' 4370 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4371 4372 4373Installing a Linux Image: 4374------------------------- 4375 4376To downloading a U-Boot image over the serial (console) interface, 4377you must convert the image to S-Record format: 4378 4379 objcopy -I binary -O srec examples/image examples/image.srec 4380 4381The 'objcopy' does not understand the information in the U-Boot 4382image header, so the resulting S-Record file will be relative to 4383address 0x00000000. To load it to a given address, you need to 4384specify the target address as 'offset' parameter with the 'loads' 4385command. 4386 4387Example: install the image to address 0x40100000 (which on the 4388TQM8xxL is in the first Flash bank): 4389 4390 => erase 40100000 401FFFFF 4391 4392 .......... done 4393 Erased 8 sectors 4394 4395 => loads 40100000 4396 ## Ready for S-Record download ... 4397 ~>examples/image.srec 4398 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4399 ... 4400 15989 15990 15991 15992 4401 [file transfer complete] 4402 [connected] 4403 ## Start Addr = 0x00000000 4404 4405 4406You can check the success of the download using the 'iminfo' command; 4407this includes a checksum verification so you can be sure no data 4408corruption happened: 4409 4410 => imi 40100000 4411 4412 ## Checking Image at 40100000 ... 4413 Image Name: 2.2.13 for initrd on TQM850L 4414 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4415 Data Size: 335725 Bytes = 327 kB = 0 MB 4416 Load Address: 00000000 4417 Entry Point: 0000000c 4418 Verifying Checksum ... OK 4419 4420 4421Boot Linux: 4422----------- 4423 4424The "bootm" command is used to boot an application that is stored in 4425memory (RAM or Flash). In case of a Linux kernel image, the contents 4426of the "bootargs" environment variable is passed to the kernel as 4427parameters. You can check and modify this variable using the 4428"printenv" and "setenv" commands: 4429 4430 4431 => printenv bootargs 4432 bootargs=root=/dev/ram 4433 4434 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4435 4436 => printenv bootargs 4437 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4438 4439 => bootm 40020000 4440 ## Booting Linux kernel at 40020000 ... 4441 Image Name: 2.2.13 for NFS on TQM850L 4442 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4443 Data Size: 381681 Bytes = 372 kB = 0 MB 4444 Load Address: 00000000 4445 Entry Point: 0000000c 4446 Verifying Checksum ... OK 4447 Uncompressing Kernel Image ... OK 4448 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 4449 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4450 time_init: decrementer frequency = 187500000/60 4451 Calibrating delay loop... 49.77 BogoMIPS 4452 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4453 ... 4454 4455If you want to boot a Linux kernel with initial RAM disk, you pass 4456the memory addresses of both the kernel and the initrd image (PPBCOOT 4457format!) to the "bootm" command: 4458 4459 => imi 40100000 40200000 4460 4461 ## Checking Image at 40100000 ... 4462 Image Name: 2.2.13 for initrd on TQM850L 4463 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4464 Data Size: 335725 Bytes = 327 kB = 0 MB 4465 Load Address: 00000000 4466 Entry Point: 0000000c 4467 Verifying Checksum ... OK 4468 4469 ## Checking Image at 40200000 ... 4470 Image Name: Simple Ramdisk Image 4471 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4472 Data Size: 566530 Bytes = 553 kB = 0 MB 4473 Load Address: 00000000 4474 Entry Point: 00000000 4475 Verifying Checksum ... OK 4476 4477 => bootm 40100000 40200000 4478 ## Booting Linux kernel at 40100000 ... 4479 Image Name: 2.2.13 for initrd on TQM850L 4480 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4481 Data Size: 335725 Bytes = 327 kB = 0 MB 4482 Load Address: 00000000 4483 Entry Point: 0000000c 4484 Verifying Checksum ... OK 4485 Uncompressing Kernel Image ... OK 4486 ## Loading RAMDisk Image at 40200000 ... 4487 Image Name: Simple Ramdisk Image 4488 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4489 Data Size: 566530 Bytes = 553 kB = 0 MB 4490 Load Address: 00000000 4491 Entry Point: 00000000 4492 Verifying Checksum ... OK 4493 Loading Ramdisk ... OK 4494 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 4495 Boot arguments: root=/dev/ram 4496 time_init: decrementer frequency = 187500000/60 4497 Calibrating delay loop... 49.77 BogoMIPS 4498 ... 4499 RAMDISK: Compressed image found at block 0 4500 VFS: Mounted root (ext2 filesystem). 4501 4502 bash# 4503 4504Boot Linux and pass a flat device tree: 4505----------- 4506 4507First, U-Boot must be compiled with the appropriate defines. See the section 4508titled "Linux Kernel Interface" above for a more in depth explanation. The 4509following is an example of how to start a kernel and pass an updated 4510flat device tree: 4511 4512=> print oftaddr 4513oftaddr=0x300000 4514=> print oft 4515oft=oftrees/mpc8540ads.dtb 4516=> tftp $oftaddr $oft 4517Speed: 1000, full duplex 4518Using TSEC0 device 4519TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4520Filename 'oftrees/mpc8540ads.dtb'. 4521Load address: 0x300000 4522Loading: # 4523done 4524Bytes transferred = 4106 (100a hex) 4525=> tftp $loadaddr $bootfile 4526Speed: 1000, full duplex 4527Using TSEC0 device 4528TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4529Filename 'uImage'. 4530Load address: 0x200000 4531Loading:############ 4532done 4533Bytes transferred = 1029407 (fb51f hex) 4534=> print loadaddr 4535loadaddr=200000 4536=> print oftaddr 4537oftaddr=0x300000 4538=> bootm $loadaddr - $oftaddr 4539## Booting image at 00200000 ... 4540 Image Name: Linux-2.6.17-dirty 4541 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4542 Data Size: 1029343 Bytes = 1005.2 kB 4543 Load Address: 00000000 4544 Entry Point: 00000000 4545 Verifying Checksum ... OK 4546 Uncompressing Kernel Image ... OK 4547Booting using flat device tree at 0x300000 4548Using MPC85xx ADS machine description 4549Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4550[snip] 4551 4552 4553More About U-Boot Image Types: 4554------------------------------ 4555 4556U-Boot supports the following image types: 4557 4558 "Standalone Programs" are directly runnable in the environment 4559 provided by U-Boot; it is expected that (if they behave 4560 well) you can continue to work in U-Boot after return from 4561 the Standalone Program. 4562 "OS Kernel Images" are usually images of some Embedded OS which 4563 will take over control completely. Usually these programs 4564 will install their own set of exception handlers, device 4565 drivers, set up the MMU, etc. - this means, that you cannot 4566 expect to re-enter U-Boot except by resetting the CPU. 4567 "RAMDisk Images" are more or less just data blocks, and their 4568 parameters (address, size) are passed to an OS kernel that is 4569 being started. 4570 "Multi-File Images" contain several images, typically an OS 4571 (Linux) kernel image and one or more data images like 4572 RAMDisks. This construct is useful for instance when you want 4573 to boot over the network using BOOTP etc., where the boot 4574 server provides just a single image file, but you want to get 4575 for instance an OS kernel and a RAMDisk image. 4576 4577 "Multi-File Images" start with a list of image sizes, each 4578 image size (in bytes) specified by an "uint32_t" in network 4579 byte order. This list is terminated by an "(uint32_t)0". 4580 Immediately after the terminating 0 follow the images, one by 4581 one, all aligned on "uint32_t" boundaries (size rounded up to 4582 a multiple of 4 bytes). 4583 4584 "Firmware Images" are binary images containing firmware (like 4585 U-Boot or FPGA images) which usually will be programmed to 4586 flash memory. 4587 4588 "Script files" are command sequences that will be executed by 4589 U-Boot's command interpreter; this feature is especially 4590 useful when you configure U-Boot to use a real shell (hush) 4591 as command interpreter. 4592 4593Booting the Linux zImage: 4594------------------------- 4595 4596On some platforms, it's possible to boot Linux zImage. This is done 4597using the "bootz" command. The syntax of "bootz" command is the same 4598as the syntax of "bootm" command. 4599 4600Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4601kernel with raw initrd images. The syntax is slightly different, the 4602address of the initrd must be augmented by it's size, in the following 4603format: "<initrd addres>:<initrd size>". 4604 4605 4606Standalone HOWTO: 4607================= 4608 4609One of the features of U-Boot is that you can dynamically load and 4610run "standalone" applications, which can use some resources of 4611U-Boot like console I/O functions or interrupt services. 4612 4613Two simple examples are included with the sources: 4614 4615"Hello World" Demo: 4616------------------- 4617 4618'examples/hello_world.c' contains a small "Hello World" Demo 4619application; it is automatically compiled when you build U-Boot. 4620It's configured to run at address 0x00040004, so you can play with it 4621like that: 4622 4623 => loads 4624 ## Ready for S-Record download ... 4625 ~>examples/hello_world.srec 4626 1 2 3 4 5 6 7 8 9 10 11 ... 4627 [file transfer complete] 4628 [connected] 4629 ## Start Addr = 0x00040004 4630 4631 => go 40004 Hello World! This is a test. 4632 ## Starting application at 0x00040004 ... 4633 Hello World 4634 argc = 7 4635 argv[0] = "40004" 4636 argv[1] = "Hello" 4637 argv[2] = "World!" 4638 argv[3] = "This" 4639 argv[4] = "is" 4640 argv[5] = "a" 4641 argv[6] = "test." 4642 argv[7] = "<NULL>" 4643 Hit any key to exit ... 4644 4645 ## Application terminated, rc = 0x0 4646 4647Another example, which demonstrates how to register a CPM interrupt 4648handler with the U-Boot code, can be found in 'examples/timer.c'. 4649Here, a CPM timer is set up to generate an interrupt every second. 4650The interrupt service routine is trivial, just printing a '.' 4651character, but this is just a demo program. The application can be 4652controlled by the following keys: 4653 4654 ? - print current values og the CPM Timer registers 4655 b - enable interrupts and start timer 4656 e - stop timer and disable interrupts 4657 q - quit application 4658 4659 => loads 4660 ## Ready for S-Record download ... 4661 ~>examples/timer.srec 4662 1 2 3 4 5 6 7 8 9 10 11 ... 4663 [file transfer complete] 4664 [connected] 4665 ## Start Addr = 0x00040004 4666 4667 => go 40004 4668 ## Starting application at 0x00040004 ... 4669 TIMERS=0xfff00980 4670 Using timer 1 4671 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4672 4673Hit 'b': 4674 [q, b, e, ?] Set interval 1000000 us 4675 Enabling timer 4676Hit '?': 4677 [q, b, e, ?] ........ 4678 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4679Hit '?': 4680 [q, b, e, ?] . 4681 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4682Hit '?': 4683 [q, b, e, ?] . 4684 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4685Hit '?': 4686 [q, b, e, ?] . 4687 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4688Hit 'e': 4689 [q, b, e, ?] ...Stopping timer 4690Hit 'q': 4691 [q, b, e, ?] ## Application terminated, rc = 0x0 4692 4693 4694Minicom warning: 4695================ 4696 4697Over time, many people have reported problems when trying to use the 4698"minicom" terminal emulation program for serial download. I (wd) 4699consider minicom to be broken, and recommend not to use it. Under 4700Unix, I recommend to use C-Kermit for general purpose use (and 4701especially for kermit binary protocol download ("loadb" command), and 4702use "cu" for S-Record download ("loads" command). See 4703http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4704for help with kermit. 4705 4706 4707Nevertheless, if you absolutely want to use it try adding this 4708configuration to your "File transfer protocols" section: 4709 4710 Name Program Name U/D FullScr IO-Red. Multi 4711 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4712 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4713 4714 4715NetBSD Notes: 4716============= 4717 4718Starting at version 0.9.2, U-Boot supports NetBSD both as host 4719(build U-Boot) and target system (boots NetBSD/mpc8xx). 4720 4721Building requires a cross environment; it is known to work on 4722NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4723need gmake since the Makefiles are not compatible with BSD make). 4724Note that the cross-powerpc package does not install include files; 4725attempting to build U-Boot will fail because <machine/ansi.h> is 4726missing. This file has to be installed and patched manually: 4727 4728 # cd /usr/pkg/cross/powerpc-netbsd/include 4729 # mkdir powerpc 4730 # ln -s powerpc machine 4731 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4732 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4733 4734Native builds *don't* work due to incompatibilities between native 4735and U-Boot include files. 4736 4737Booting assumes that (the first part of) the image booted is a 4738stage-2 loader which in turn loads and then invokes the kernel 4739proper. Loader sources will eventually appear in the NetBSD source 4740tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4741meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4742 4743 4744Implementation Internals: 4745========================= 4746 4747The following is not intended to be a complete description of every 4748implementation detail. However, it should help to understand the 4749inner workings of U-Boot and make it easier to port it to custom 4750hardware. 4751 4752 4753Initial Stack, Global Data: 4754--------------------------- 4755 4756The implementation of U-Boot is complicated by the fact that U-Boot 4757starts running out of ROM (flash memory), usually without access to 4758system RAM (because the memory controller is not initialized yet). 4759This means that we don't have writable Data or BSS segments, and BSS 4760is not initialized as zero. To be able to get a C environment working 4761at all, we have to allocate at least a minimal stack. Implementation 4762options for this are defined and restricted by the CPU used: Some CPU 4763models provide on-chip memory (like the IMMR area on MPC8xx and 4764MPC826x processors), on others (parts of) the data cache can be 4765locked as (mis-) used as memory, etc. 4766 4767 Chris Hallinan posted a good summary of these issues to the 4768 U-Boot mailing list: 4769 4770 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4771 From: "Chris Hallinan" <clh@net1plus.com> 4772 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4773 ... 4774 4775 Correct me if I'm wrong, folks, but the way I understand it 4776 is this: Using DCACHE as initial RAM for Stack, etc, does not 4777 require any physical RAM backing up the cache. The cleverness 4778 is that the cache is being used as a temporary supply of 4779 necessary storage before the SDRAM controller is setup. It's 4780 beyond the scope of this list to explain the details, but you 4781 can see how this works by studying the cache architecture and 4782 operation in the architecture and processor-specific manuals. 4783 4784 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4785 is another option for the system designer to use as an 4786 initial stack/RAM area prior to SDRAM being available. Either 4787 option should work for you. Using CS 4 should be fine if your 4788 board designers haven't used it for something that would 4789 cause you grief during the initial boot! It is frequently not 4790 used. 4791 4792 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4793 with your processor/board/system design. The default value 4794 you will find in any recent u-boot distribution in 4795 walnut.h should work for you. I'd set it to a value larger 4796 than your SDRAM module. If you have a 64MB SDRAM module, set 4797 it above 400_0000. Just make sure your board has no resources 4798 that are supposed to respond to that address! That code in 4799 start.S has been around a while and should work as is when 4800 you get the config right. 4801 4802 -Chris Hallinan 4803 DS4.COM, Inc. 4804 4805It is essential to remember this, since it has some impact on the C 4806code for the initialization procedures: 4807 4808* Initialized global data (data segment) is read-only. Do not attempt 4809 to write it. 4810 4811* Do not use any uninitialized global data (or implicitly initialized 4812 as zero data - BSS segment) at all - this is undefined, initiali- 4813 zation is performed later (when relocating to RAM). 4814 4815* Stack space is very limited. Avoid big data buffers or things like 4816 that. 4817 4818Having only the stack as writable memory limits means we cannot use 4819normal global data to share information between the code. But it 4820turned out that the implementation of U-Boot can be greatly 4821simplified by making a global data structure (gd_t) available to all 4822functions. We could pass a pointer to this data as argument to _all_ 4823functions, but this would bloat the code. Instead we use a feature of 4824the GCC compiler (Global Register Variables) to share the data: we 4825place a pointer (gd) to the global data into a register which we 4826reserve for this purpose. 4827 4828When choosing a register for such a purpose we are restricted by the 4829relevant (E)ABI specifications for the current architecture, and by 4830GCC's implementation. 4831 4832For PowerPC, the following registers have specific use: 4833 R1: stack pointer 4834 R2: reserved for system use 4835 R3-R4: parameter passing and return values 4836 R5-R10: parameter passing 4837 R13: small data area pointer 4838 R30: GOT pointer 4839 R31: frame pointer 4840 4841 (U-Boot also uses R12 as internal GOT pointer. r12 4842 is a volatile register so r12 needs to be reset when 4843 going back and forth between asm and C) 4844 4845 ==> U-Boot will use R2 to hold a pointer to the global data 4846 4847 Note: on PPC, we could use a static initializer (since the 4848 address of the global data structure is known at compile time), 4849 but it turned out that reserving a register results in somewhat 4850 smaller code - although the code savings are not that big (on 4851 average for all boards 752 bytes for the whole U-Boot image, 4852 624 text + 127 data). 4853 4854On ARM, the following registers are used: 4855 4856 R0: function argument word/integer result 4857 R1-R3: function argument word 4858 R9: platform specific 4859 R10: stack limit (used only if stack checking is enabled) 4860 R11: argument (frame) pointer 4861 R12: temporary workspace 4862 R13: stack pointer 4863 R14: link register 4864 R15: program counter 4865 4866 ==> U-Boot will use R9 to hold a pointer to the global data 4867 4868 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4869 4870On Nios II, the ABI is documented here: 4871 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4872 4873 ==> U-Boot will use gp to hold a pointer to the global data 4874 4875 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4876 to access small data sections, so gp is free. 4877 4878On NDS32, the following registers are used: 4879 4880 R0-R1: argument/return 4881 R2-R5: argument 4882 R15: temporary register for assembler 4883 R16: trampoline register 4884 R28: frame pointer (FP) 4885 R29: global pointer (GP) 4886 R30: link register (LP) 4887 R31: stack pointer (SP) 4888 PC: program counter (PC) 4889 4890 ==> U-Boot will use R10 to hold a pointer to the global data 4891 4892NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4893or current versions of GCC may "optimize" the code too much. 4894 4895On RISC-V, the following registers are used: 4896 4897 x0: hard-wired zero (zero) 4898 x1: return address (ra) 4899 x2: stack pointer (sp) 4900 x3: global pointer (gp) 4901 x4: thread pointer (tp) 4902 x5: link register (t0) 4903 x8: frame pointer (fp) 4904 x10-x11: arguments/return values (a0-1) 4905 x12-x17: arguments (a2-7) 4906 x28-31: temporaries (t3-6) 4907 pc: program counter (pc) 4908 4909 ==> U-Boot will use gp to hold a pointer to the global data 4910 4911Memory Management: 4912------------------ 4913 4914U-Boot runs in system state and uses physical addresses, i.e. the 4915MMU is not used either for address mapping nor for memory protection. 4916 4917The available memory is mapped to fixed addresses using the memory 4918controller. In this process, a contiguous block is formed for each 4919memory type (Flash, SDRAM, SRAM), even when it consists of several 4920physical memory banks. 4921 4922U-Boot is installed in the first 128 kB of the first Flash bank (on 4923TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4924booting and sizing and initializing DRAM, the code relocates itself 4925to the upper end of DRAM. Immediately below the U-Boot code some 4926memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4927configuration setting]. Below that, a structure with global Board 4928Info data is placed, followed by the stack (growing downward). 4929 4930Additionally, some exception handler code is copied to the low 8 kB 4931of DRAM (0x00000000 ... 0x00001FFF). 4932 4933So a typical memory configuration with 16 MB of DRAM could look like 4934this: 4935 4936 0x0000 0000 Exception Vector code 4937 : 4938 0x0000 1FFF 4939 0x0000 2000 Free for Application Use 4940 : 4941 : 4942 4943 : 4944 : 4945 0x00FB FF20 Monitor Stack (Growing downward) 4946 0x00FB FFAC Board Info Data and permanent copy of global data 4947 0x00FC 0000 Malloc Arena 4948 : 4949 0x00FD FFFF 4950 0x00FE 0000 RAM Copy of Monitor Code 4951 ... eventually: LCD or video framebuffer 4952 ... eventually: pRAM (Protected RAM - unchanged by reset) 4953 0x00FF FFFF [End of RAM] 4954 4955 4956System Initialization: 4957---------------------- 4958 4959In the reset configuration, U-Boot starts at the reset entry point 4960(on most PowerPC systems at address 0x00000100). Because of the reset 4961configuration for CS0# this is a mirror of the on board Flash memory. 4962To be able to re-map memory U-Boot then jumps to its link address. 4963To be able to implement the initialization code in C, a (small!) 4964initial stack is set up in the internal Dual Ported RAM (in case CPUs 4965which provide such a feature like), or in a locked part of the data 4966cache. After that, U-Boot initializes the CPU core, the caches and 4967the SIU. 4968 4969Next, all (potentially) available memory banks are mapped using a 4970preliminary mapping. For example, we put them on 512 MB boundaries 4971(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4972on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4973programmed for SDRAM access. Using the temporary configuration, a 4974simple memory test is run that determines the size of the SDRAM 4975banks. 4976 4977When there is more than one SDRAM bank, and the banks are of 4978different size, the largest is mapped first. For equal size, the first 4979bank (CS2#) is mapped first. The first mapping is always for address 49800x00000000, with any additional banks following immediately to create 4981contiguous memory starting from 0. 4982 4983Then, the monitor installs itself at the upper end of the SDRAM area 4984and allocates memory for use by malloc() and for the global Board 4985Info data; also, the exception vector code is copied to the low RAM 4986pages, and the final stack is set up. 4987 4988Only after this relocation will you have a "normal" C environment; 4989until that you are restricted in several ways, mostly because you are 4990running from ROM, and because the code will have to be relocated to a 4991new address in RAM. 4992 4993 4994U-Boot Porting Guide: 4995---------------------- 4996 4997[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4998list, October 2002] 4999 5000 5001int main(int argc, char *argv[]) 5002{ 5003 sighandler_t no_more_time; 5004 5005 signal(SIGALRM, no_more_time); 5006 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 5007 5008 if (available_money > available_manpower) { 5009 Pay consultant to port U-Boot; 5010 return 0; 5011 } 5012 5013 Download latest U-Boot source; 5014 5015 Subscribe to u-boot mailing list; 5016 5017 if (clueless) 5018 email("Hi, I am new to U-Boot, how do I get started?"); 5019 5020 while (learning) { 5021 Read the README file in the top level directory; 5022 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 5023 Read applicable doc/*.README; 5024 Read the source, Luke; 5025 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 5026 } 5027 5028 if (available_money > toLocalCurrency ($2500)) 5029 Buy a BDI3000; 5030 else 5031 Add a lot of aggravation and time; 5032 5033 if (a similar board exists) { /* hopefully... */ 5034 cp -a board/<similar> board/<myboard> 5035 cp include/configs/<similar>.h include/configs/<myboard>.h 5036 } else { 5037 Create your own board support subdirectory; 5038 Create your own board include/configs/<myboard>.h file; 5039 } 5040 Edit new board/<myboard> files 5041 Edit new include/configs/<myboard>.h 5042 5043 while (!accepted) { 5044 while (!running) { 5045 do { 5046 Add / modify source code; 5047 } until (compiles); 5048 Debug; 5049 if (clueless) 5050 email("Hi, I am having problems..."); 5051 } 5052 Send patch file to the U-Boot email list; 5053 if (reasonable critiques) 5054 Incorporate improvements from email list code review; 5055 else 5056 Defend code as written; 5057 } 5058 5059 return 0; 5060} 5061 5062void no_more_time (int sig) 5063{ 5064 hire_a_guru(); 5065} 5066 5067 5068Coding Standards: 5069----------------- 5070 5071All contributions to U-Boot should conform to the Linux kernel 5072coding style; see the kernel coding style guide at 5073https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 5074script "scripts/Lindent" in your Linux kernel source directory. 5075 5076Source files originating from a different project (for example the 5077MTD subsystem) are generally exempt from these guidelines and are not 5078reformatted to ease subsequent migration to newer versions of those 5079sources. 5080 5081Please note that U-Boot is implemented in C (and to some small parts in 5082Assembler); no C++ is used, so please do not use C++ style comments (//) 5083in your code. 5084 5085Please also stick to the following formatting rules: 5086- remove any trailing white space 5087- use TAB characters for indentation and vertical alignment, not spaces 5088- make sure NOT to use DOS '\r\n' line feeds 5089- do not add more than 2 consecutive empty lines to source files 5090- do not add trailing empty lines to source files 5091 5092Submissions which do not conform to the standards may be returned 5093with a request to reformat the changes. 5094 5095 5096Submitting Patches: 5097------------------- 5098 5099Since the number of patches for U-Boot is growing, we need to 5100establish some rules. Submissions which do not conform to these rules 5101may be rejected, even when they contain important and valuable stuff. 5102 5103Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5104 5105Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5106see https://lists.denx.de/listinfo/u-boot 5107 5108When you send a patch, please include the following information with 5109it: 5110 5111* For bug fixes: a description of the bug and how your patch fixes 5112 this bug. Please try to include a way of demonstrating that the 5113 patch actually fixes something. 5114 5115* For new features: a description of the feature and your 5116 implementation. 5117 5118* A CHANGELOG entry as plaintext (separate from the patch) 5119 5120* For major contributions, add a MAINTAINERS file with your 5121 information and associated file and directory references. 5122 5123* When you add support for a new board, don't forget to add a 5124 maintainer e-mail address to the boards.cfg file, too. 5125 5126* If your patch adds new configuration options, don't forget to 5127 document these in the README file. 5128 5129* The patch itself. If you are using git (which is *strongly* 5130 recommended) you can easily generate the patch using the 5131 "git format-patch". If you then use "git send-email" to send it to 5132 the U-Boot mailing list, you will avoid most of the common problems 5133 with some other mail clients. 5134 5135 If you cannot use git, use "diff -purN OLD NEW". If your version of 5136 diff does not support these options, then get the latest version of 5137 GNU diff. 5138 5139 The current directory when running this command shall be the parent 5140 directory of the U-Boot source tree (i. e. please make sure that 5141 your patch includes sufficient directory information for the 5142 affected files). 5143 5144 We prefer patches as plain text. MIME attachments are discouraged, 5145 and compressed attachments must not be used. 5146 5147* If one logical set of modifications affects or creates several 5148 files, all these changes shall be submitted in a SINGLE patch file. 5149 5150* Changesets that contain different, unrelated modifications shall be 5151 submitted as SEPARATE patches, one patch per changeset. 5152 5153 5154Notes: 5155 5156* Before sending the patch, run the buildman script on your patched 5157 source tree and make sure that no errors or warnings are reported 5158 for any of the boards. 5159 5160* Keep your modifications to the necessary minimum: A patch 5161 containing several unrelated changes or arbitrary reformats will be 5162 returned with a request to re-formatting / split it. 5163 5164* If you modify existing code, make sure that your new code does not 5165 add to the memory footprint of the code ;-) Small is beautiful! 5166 When adding new features, these should compile conditionally only 5167 (using #ifdef), and the resulting code with the new feature 5168 disabled must not need more memory than the old code without your 5169 modification. 5170 5171* Remember that there is a size limit of 100 kB per message on the 5172 u-boot mailing list. Bigger patches will be moderated. If they are 5173 reasonable and not too big, they will be acknowledged. But patches 5174 bigger than the size limit should be avoided. 5175