1# 2# (C) Copyright 2000 - 2013 3# Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4# 5# SPDX-License-Identifier: GPL-2.0+ 6# 7 8Summary: 9======== 10 11This directory contains the source code for U-Boot, a boot loader for 12Embedded boards based on PowerPC, ARM, MIPS and several other 13processors, which can be installed in a boot ROM and used to 14initialize and test the hardware or to download and run application 15code. 16 17The development of U-Boot is closely related to Linux: some parts of 18the source code originate in the Linux source tree, we have some 19header files in common, and special provision has been made to 20support booting of Linux images. 21 22Some attention has been paid to make this software easily 23configurable and extendable. For instance, all monitor commands are 24implemented with the same call interface, so that it's very easy to 25add new commands. Also, instead of permanently adding rarely used 26code (for instance hardware test utilities) to the monitor, you can 27load and run it dynamically. 28 29 30Status: 31======= 32 33In general, all boards for which a configuration option exists in the 34Makefile have been tested to some extent and can be considered 35"working". In fact, many of them are used in production systems. 36 37In case of problems see the CHANGELOG file to find out who contributed 38the specific port. In addition, there are various MAINTAINERS files 39scattered throughout the U-Boot source identifying the people or 40companies responsible for various boards and subsystems. 41 42Note: As of August, 2010, there is no longer a CHANGELOG file in the 43actual U-Boot source tree; however, it can be created dynamically 44from the Git log using: 45 46 make CHANGELOG 47 48 49Where to get help: 50================== 51 52In case you have questions about, problems with or contributions for 53U-Boot, you should send a message to the U-Boot mailing list at 54<u-boot@lists.denx.de>. There is also an archive of previous traffic 55on the mailing list - please search the archive before asking FAQ's. 56Please see http://lists.denx.de/pipermail/u-boot and 57http://dir.gmane.org/gmane.comp.boot-loaders.u-boot 58 59 60Where to get source code: 61========================= 62 63The U-Boot source code is maintained in the Git repository at 64git://www.denx.de/git/u-boot.git ; you can browse it online at 65http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary 66 67The "snapshot" links on this page allow you to download tarballs of 68any version you might be interested in. Official releases are also 69available for FTP download from the ftp://ftp.denx.de/pub/u-boot/ 70directory. 71 72Pre-built (and tested) images are available from 73ftp://ftp.denx.de/pub/u-boot/images/ 74 75 76Where we come from: 77=================== 78 79- start from 8xxrom sources 80- create PPCBoot project (http://sourceforge.net/projects/ppcboot) 81- clean up code 82- make it easier to add custom boards 83- make it possible to add other [PowerPC] CPUs 84- extend functions, especially: 85 * Provide extended interface to Linux boot loader 86 * S-Record download 87 * network boot 88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot 89- create ARMBoot project (http://sourceforge.net/projects/armboot) 90- add other CPU families (starting with ARM) 91- create U-Boot project (http://sourceforge.net/projects/u-boot) 92- current project page: see http://www.denx.de/wiki/U-Boot 93 94 95Names and Spelling: 96=================== 97 98The "official" name of this project is "Das U-Boot". The spelling 99"U-Boot" shall be used in all written text (documentation, comments 100in source files etc.). Example: 101 102 This is the README file for the U-Boot project. 103 104File names etc. shall be based on the string "u-boot". Examples: 105 106 include/asm-ppc/u-boot.h 107 108 #include <asm/u-boot.h> 109 110Variable names, preprocessor constants etc. shall be either based on 111the string "u_boot" or on "U_BOOT". Example: 112 113 U_BOOT_VERSION u_boot_logo 114 IH_OS_U_BOOT u_boot_hush_start 115 116 117Versioning: 118=========== 119 120Starting with the release in October 2008, the names of the releases 121were changed from numerical release numbers without deeper meaning 122into a time stamp based numbering. Regular releases are identified by 123names consisting of the calendar year and month of the release date. 124Additional fields (if present) indicate release candidates or bug fix 125releases in "stable" maintenance trees. 126 127Examples: 128 U-Boot v2009.11 - Release November 2009 129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree 130 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release 131 132 133Directory Hierarchy: 134==================== 135 136/arch Architecture specific files 137 /arc Files generic to ARC architecture 138 /arm Files generic to ARM architecture 139 /m68k Files generic to m68k architecture 140 /microblaze Files generic to microblaze architecture 141 /mips Files generic to MIPS architecture 142 /nds32 Files generic to NDS32 architecture 143 /nios2 Files generic to Altera NIOS2 architecture 144 /openrisc Files generic to OpenRISC architecture 145 /powerpc Files generic to PowerPC architecture 146 /riscv Files generic to RISC-V architecture 147 /sandbox Files generic to HW-independent "sandbox" 148 /sh Files generic to SH architecture 149 /x86 Files generic to x86 architecture 150/api Machine/arch independent API for external apps 151/board Board dependent files 152/cmd U-Boot commands functions 153/common Misc architecture independent functions 154/configs Board default configuration files 155/disk Code for disk drive partition handling 156/doc Documentation (don't expect too much) 157/drivers Commonly used device drivers 158/dts Contains Makefile for building internal U-Boot fdt. 159/examples Example code for standalone applications, etc. 160/fs Filesystem code (cramfs, ext2, jffs2, etc.) 161/include Header Files 162/lib Library routines generic to all architectures 163/Licenses Various license files 164/net Networking code 165/post Power On Self Test 166/scripts Various build scripts and Makefiles 167/test Various unit test files 168/tools Tools to build S-Record or U-Boot images, etc. 169 170Software Configuration: 171======================= 172 173Configuration is usually done using C preprocessor defines; the 174rationale behind that is to avoid dead code whenever possible. 175 176There are two classes of configuration variables: 177 178* Configuration _OPTIONS_: 179 These are selectable by the user and have names beginning with 180 "CONFIG_". 181 182* Configuration _SETTINGS_: 183 These depend on the hardware etc. and should not be meddled with if 184 you don't know what you're doing; they have names beginning with 185 "CONFIG_SYS_". 186 187Previously, all configuration was done by hand, which involved creating 188symbolic links and editing configuration files manually. More recently, 189U-Boot has added the Kbuild infrastructure used by the Linux kernel, 190allowing you to use the "make menuconfig" command to configure your 191build. 192 193 194Selection of Processor Architecture and Board Type: 195--------------------------------------------------- 196 197For all supported boards there are ready-to-use default 198configurations available; just type "make <board_name>_defconfig". 199 200Example: For a TQM823L module type: 201 202 cd u-boot 203 make TQM823L_defconfig 204 205Note: If you're looking for the default configuration file for a board 206you're sure used to be there but is now missing, check the file 207doc/README.scrapyard for a list of no longer supported boards. 208 209Sandbox Environment: 210-------------------- 211 212U-Boot can be built natively to run on a Linux host using the 'sandbox' 213board. This allows feature development which is not board- or architecture- 214specific to be undertaken on a native platform. The sandbox is also used to 215run some of U-Boot's tests. 216 217See board/sandbox/README.sandbox for more details. 218 219 220Board Initialisation Flow: 221-------------------------- 222 223This is the intended start-up flow for boards. This should apply for both 224SPL and U-Boot proper (i.e. they both follow the same rules). 225 226Note: "SPL" stands for "Secondary Program Loader," which is explained in 227more detail later in this file. 228 229At present, SPL mostly uses a separate code path, but the function names 230and roles of each function are the same. Some boards or architectures 231may not conform to this. At least most ARM boards which use 232CONFIG_SPL_FRAMEWORK conform to this. 233 234Execution typically starts with an architecture-specific (and possibly 235CPU-specific) start.S file, such as: 236 237 - arch/arm/cpu/armv7/start.S 238 - arch/powerpc/cpu/mpc83xx/start.S 239 - arch/mips/cpu/start.S 240 241and so on. From there, three functions are called; the purpose and 242limitations of each of these functions are described below. 243 244lowlevel_init(): 245 - purpose: essential init to permit execution to reach board_init_f() 246 - no global_data or BSS 247 - there is no stack (ARMv7 may have one but it will soon be removed) 248 - must not set up SDRAM or use console 249 - must only do the bare minimum to allow execution to continue to 250 board_init_f() 251 - this is almost never needed 252 - return normally from this function 253 254board_init_f(): 255 - purpose: set up the machine ready for running board_init_r(): 256 i.e. SDRAM and serial UART 257 - global_data is available 258 - stack is in SRAM 259 - BSS is not available, so you cannot use global/static variables, 260 only stack variables and global_data 261 262 Non-SPL-specific notes: 263 - dram_init() is called to set up DRAM. If already done in SPL this 264 can do nothing 265 266 SPL-specific notes: 267 - you can override the entire board_init_f() function with your own 268 version as needed. 269 - preloader_console_init() can be called here in extremis 270 - should set up SDRAM, and anything needed to make the UART work 271 - these is no need to clear BSS, it will be done by crt0.S 272 - must return normally from this function (don't call board_init_r() 273 directly) 274 275Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at 276this point the stack and global_data are relocated to below 277CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of 278memory. 279 280board_init_r(): 281 - purpose: main execution, common code 282 - global_data is available 283 - SDRAM is available 284 - BSS is available, all static/global variables can be used 285 - execution eventually continues to main_loop() 286 287 Non-SPL-specific notes: 288 - U-Boot is relocated to the top of memory and is now running from 289 there. 290 291 SPL-specific notes: 292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and 293 CONFIG_SPL_STACK_R_ADDR points into SDRAM 294 - preloader_console_init() can be called here - typically this is 295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a 296 spl_board_init() function containing this call 297 - loads U-Boot or (in falcon mode) Linux 298 299 300 301Configuration Options: 302---------------------- 303 304Configuration depends on the combination of board and CPU type; all 305such information is kept in a configuration file 306"include/configs/<board_name>.h". 307 308Example: For a TQM823L module, all configuration settings are in 309"include/configs/TQM823L.h". 310 311 312Many of the options are named exactly as the corresponding Linux 313kernel configuration options. The intention is to make it easier to 314build a config tool - later. 315 316- ARM Platform Bus Type(CCI): 317 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which 318 provides full cache coherency between two clusters of multi-core 319 CPUs and I/O coherency for devices and I/O masters 320 321 CONFIG_SYS_FSL_HAS_CCI400 322 323 Defined For SoC that has cache coherent interconnect 324 CCN-400 325 326 CONFIG_SYS_FSL_HAS_CCN504 327 328 Defined for SoC that has cache coherent interconnect CCN-504 329 330The following options need to be configured: 331 332- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX. 333 334- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS. 335 336- Marvell Family Member 337 CONFIG_SYS_MVFS - define it if you want to enable 338 multiple fs option at one time 339 for marvell soc family 340 341- 85xx CPU Options: 342 CONFIG_SYS_PPC64 343 344 Specifies that the core is a 64-bit PowerPC implementation (implements 345 the "64" category of the Power ISA). This is necessary for ePAPR 346 compliance, among other possible reasons. 347 348 CONFIG_SYS_FSL_TBCLK_DIV 349 350 Defines the core time base clock divider ratio compared to the 351 system clock. On most PQ3 devices this is 8, on newer QorIQ 352 devices it can be 16 or 32. The ratio varies from SoC to Soc. 353 354 CONFIG_SYS_FSL_PCIE_COMPAT 355 356 Defines the string to utilize when trying to match PCIe device 357 tree nodes for the given platform. 358 359 CONFIG_SYS_FSL_ERRATUM_A004510 360 361 Enables a workaround for erratum A004510. If set, 362 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and 363 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set. 364 365 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 366 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional) 367 368 Defines one or two SoC revisions (low 8 bits of SVR) 369 for which the A004510 workaround should be applied. 370 371 The rest of SVR is either not relevant to the decision 372 of whether the erratum is present (e.g. p2040 versus 373 p2041) or is implied by the build target, which controls 374 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set. 375 376 See Freescale App Note 4493 for more information about 377 this erratum. 378 379 CONFIG_A003399_NOR_WORKAROUND 380 Enables a workaround for IFC erratum A003399. It is only 381 required during NOR boot. 382 383 CONFIG_A008044_WORKAROUND 384 Enables a workaround for T1040/T1042 erratum A008044. It is only 385 required during NAND boot and valid for Rev 1.0 SoC revision 386 387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 388 389 This is the value to write into CCSR offset 0x18600 390 according to the A004510 workaround. 391 392 CONFIG_SYS_FSL_DSP_DDR_ADDR 393 This value denotes start offset of DDR memory which is 394 connected exclusively to the DSP cores. 395 396 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR 397 This value denotes start offset of M2 memory 398 which is directly connected to the DSP core. 399 400 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR 401 This value denotes start offset of M3 memory which is directly 402 connected to the DSP core. 403 404 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT 405 This value denotes start offset of DSP CCSR space. 406 407 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK 408 Single Source Clock is clocking mode present in some of FSL SoC's. 409 In this mode, a single differential clock is used to supply 410 clocks to the sysclock, ddrclock and usbclock. 411 412 CONFIG_SYS_CPC_REINIT_F 413 This CONFIG is defined when the CPC is configured as SRAM at the 414 time of U-Boot entry and is required to be re-initialized. 415 416 CONFIG_DEEP_SLEEP 417 Indicates this SoC supports deep sleep feature. If deep sleep is 418 supported, core will start to execute uboot when wakes up. 419 420- Generic CPU options: 421 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN 422 423 Defines the endianess of the CPU. Implementation of those 424 values is arch specific. 425 426 CONFIG_SYS_FSL_DDR 427 Freescale DDR driver in use. This type of DDR controller is 428 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core 429 SoCs. 430 431 CONFIG_SYS_FSL_DDR_ADDR 432 Freescale DDR memory-mapped register base. 433 434 CONFIG_SYS_FSL_DDR_EMU 435 Specify emulator support for DDR. Some DDR features such as 436 deskew training are not available. 437 438 CONFIG_SYS_FSL_DDRC_GEN1 439 Freescale DDR1 controller. 440 441 CONFIG_SYS_FSL_DDRC_GEN2 442 Freescale DDR2 controller. 443 444 CONFIG_SYS_FSL_DDRC_GEN3 445 Freescale DDR3 controller. 446 447 CONFIG_SYS_FSL_DDRC_GEN4 448 Freescale DDR4 controller. 449 450 CONFIG_SYS_FSL_DDRC_ARM_GEN3 451 Freescale DDR3 controller for ARM-based SoCs. 452 453 CONFIG_SYS_FSL_DDR1 454 Board config to use DDR1. It can be enabled for SoCs with 455 Freescale DDR1 or DDR2 controllers, depending on the board 456 implemetation. 457 458 CONFIG_SYS_FSL_DDR2 459 Board config to use DDR2. It can be enabled for SoCs with 460 Freescale DDR2 or DDR3 controllers, depending on the board 461 implementation. 462 463 CONFIG_SYS_FSL_DDR3 464 Board config to use DDR3. It can be enabled for SoCs with 465 Freescale DDR3 or DDR3L controllers. 466 467 CONFIG_SYS_FSL_DDR3L 468 Board config to use DDR3L. It can be enabled for SoCs with 469 DDR3L controllers. 470 471 CONFIG_SYS_FSL_DDR4 472 Board config to use DDR4. It can be enabled for SoCs with 473 DDR4 controllers. 474 475 CONFIG_SYS_FSL_IFC_BE 476 Defines the IFC controller register space as Big Endian 477 478 CONFIG_SYS_FSL_IFC_LE 479 Defines the IFC controller register space as Little Endian 480 481 CONFIG_SYS_FSL_IFC_CLK_DIV 482 Defines divider of platform clock(clock input to IFC controller). 483 484 CONFIG_SYS_FSL_LBC_CLK_DIV 485 Defines divider of platform clock(clock input to eLBC controller). 486 487 CONFIG_SYS_FSL_PBL_PBI 488 It enables addition of RCW (Power on reset configuration) in built image. 489 Please refer doc/README.pblimage for more details 490 491 CONFIG_SYS_FSL_PBL_RCW 492 It adds PBI(pre-boot instructions) commands in u-boot build image. 493 PBI commands can be used to configure SoC before it starts the execution. 494 Please refer doc/README.pblimage for more details 495 496 CONFIG_SPL_FSL_PBL 497 It adds a target to create boot binary having SPL binary in PBI format 498 concatenated with u-boot binary. 499 500 CONFIG_SYS_FSL_DDR_BE 501 Defines the DDR controller register space as Big Endian 502 503 CONFIG_SYS_FSL_DDR_LE 504 Defines the DDR controller register space as Little Endian 505 506 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY 507 Physical address from the view of DDR controllers. It is the 508 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But 509 it could be different for ARM SoCs. 510 511 CONFIG_SYS_FSL_DDR_INTLV_256B 512 DDR controller interleaving on 256-byte. This is a special 513 interleaving mode, handled by Dickens for Freescale layerscape 514 SoCs with ARM core. 515 516 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS 517 Number of controllers used as main memory. 518 519 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS 520 Number of controllers used for other than main memory. 521 522 CONFIG_SYS_FSL_HAS_DP_DDR 523 Defines the SoC has DP-DDR used for DPAA. 524 525 CONFIG_SYS_FSL_SEC_BE 526 Defines the SEC controller register space as Big Endian 527 528 CONFIG_SYS_FSL_SEC_LE 529 Defines the SEC controller register space as Little Endian 530 531- MIPS CPU options: 532 CONFIG_SYS_INIT_SP_OFFSET 533 534 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack 535 pointer. This is needed for the temporary stack before 536 relocation. 537 538 CONFIG_SYS_MIPS_CACHE_MODE 539 540 Cache operation mode for the MIPS CPU. 541 See also arch/mips/include/asm/mipsregs.h. 542 Possible values are: 543 CONF_CM_CACHABLE_NO_WA 544 CONF_CM_CACHABLE_WA 545 CONF_CM_UNCACHED 546 CONF_CM_CACHABLE_NONCOHERENT 547 CONF_CM_CACHABLE_CE 548 CONF_CM_CACHABLE_COW 549 CONF_CM_CACHABLE_CUW 550 CONF_CM_CACHABLE_ACCELERATED 551 552 CONFIG_SYS_XWAY_EBU_BOOTCFG 553 554 Special option for Lantiq XWAY SoCs for booting from NOR flash. 555 See also arch/mips/cpu/mips32/start.S. 556 557 CONFIG_XWAY_SWAP_BYTES 558 559 Enable compilation of tools/xway-swap-bytes needed for Lantiq 560 XWAY SoCs for booting from NOR flash. The U-Boot image needs to 561 be swapped if a flash programmer is used. 562 563- ARM options: 564 CONFIG_SYS_EXCEPTION_VECTORS_HIGH 565 566 Select high exception vectors of the ARM core, e.g., do not 567 clear the V bit of the c1 register of CP15. 568 569 COUNTER_FREQUENCY 570 Generic timer clock source frequency. 571 572 COUNTER_FREQUENCY_REAL 573 Generic timer clock source frequency if the real clock is 574 different from COUNTER_FREQUENCY, and can only be determined 575 at run time. 576 577- Tegra SoC options: 578 CONFIG_TEGRA_SUPPORT_NON_SECURE 579 580 Support executing U-Boot in non-secure (NS) mode. Certain 581 impossible actions will be skipped if the CPU is in NS mode, 582 such as ARM architectural timer initialization. 583 584- Linux Kernel Interface: 585 CONFIG_CLOCKS_IN_MHZ 586 587 U-Boot stores all clock information in Hz 588 internally. For binary compatibility with older Linux 589 kernels (which expect the clocks passed in the 590 bd_info data to be in MHz) the environment variable 591 "clocks_in_mhz" can be defined so that U-Boot 592 converts clock data to MHZ before passing it to the 593 Linux kernel. 594 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of 595 "clocks_in_mhz=1" is automatically included in the 596 default environment. 597 598 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only] 599 600 When transferring memsize parameter to Linux, some versions 601 expect it to be in bytes, others in MB. 602 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes. 603 604 CONFIG_OF_LIBFDT 605 606 New kernel versions are expecting firmware settings to be 607 passed using flattened device trees (based on open firmware 608 concepts). 609 610 CONFIG_OF_LIBFDT 611 * New libfdt-based support 612 * Adds the "fdt" command 613 * The bootm command automatically updates the fdt 614 615 OF_TBCLK - The timebase frequency. 616 OF_STDOUT_PATH - The path to the console device 617 618 boards with QUICC Engines require OF_QE to set UCC MAC 619 addresses 620 621 CONFIG_OF_BOARD_SETUP 622 623 Board code has addition modification that it wants to make 624 to the flat device tree before handing it off to the kernel 625 626 CONFIG_OF_SYSTEM_SETUP 627 628 Other code has addition modification that it wants to make 629 to the flat device tree before handing it off to the kernel. 630 This causes ft_system_setup() to be called before booting 631 the kernel. 632 633 CONFIG_OF_IDE_FIXUP 634 635 U-Boot can detect if an IDE device is present or not. 636 If not, and this new config option is activated, U-Boot 637 removes the ATA node from the DTS before booting Linux, 638 so the Linux IDE driver does not probe the device and 639 crash. This is needed for buggy hardware (uc101) where 640 no pull down resistor is connected to the signal IDE5V_DD7. 641 642 CONFIG_MACH_TYPE [relevant for ARM only][mandatory] 643 644 This setting is mandatory for all boards that have only one 645 machine type and must be used to specify the machine type 646 number as it appears in the ARM machine registry 647 (see http://www.arm.linux.org.uk/developer/machines/). 648 Only boards that have multiple machine types supported 649 in a single configuration file and the machine type is 650 runtime discoverable, do not have to use this setting. 651 652- vxWorks boot parameters: 653 654 bootvx constructs a valid bootline using the following 655 environments variables: bootdev, bootfile, ipaddr, netmask, 656 serverip, gatewayip, hostname, othbootargs. 657 It loads the vxWorks image pointed bootfile. 658 659 Note: If a "bootargs" environment is defined, it will overwride 660 the defaults discussed just above. 661 662- Cache Configuration: 663 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot 664 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot 665 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot 666 667- Cache Configuration for ARM: 668 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache 669 controller 670 CONFIG_SYS_PL310_BASE - Physical base address of PL310 671 controller register space 672 673- Serial Ports: 674 CONFIG_PL010_SERIAL 675 676 Define this if you want support for Amba PrimeCell PL010 UARTs. 677 678 CONFIG_PL011_SERIAL 679 680 Define this if you want support for Amba PrimeCell PL011 UARTs. 681 682 CONFIG_PL011_CLOCK 683 684 If you have Amba PrimeCell PL011 UARTs, set this variable to 685 the clock speed of the UARTs. 686 687 CONFIG_PL01x_PORTS 688 689 If you have Amba PrimeCell PL010 or PL011 UARTs on your board, 690 define this to a list of base addresses for each (supported) 691 port. See e.g. include/configs/versatile.h 692 693 CONFIG_SERIAL_HW_FLOW_CONTROL 694 695 Define this variable to enable hw flow control in serial driver. 696 Current user of this option is drivers/serial/nsl16550.c driver 697 698- Console Baudrate: 699 CONFIG_BAUDRATE - in bps 700 Select one of the baudrates listed in 701 CONFIG_SYS_BAUDRATE_TABLE, see below. 702 703- Autoboot Command: 704 CONFIG_BOOTCOMMAND 705 Only needed when CONFIG_BOOTDELAY is enabled; 706 define a command string that is automatically executed 707 when no character is read on the console interface 708 within "Boot Delay" after reset. 709 710 CONFIG_RAMBOOT and CONFIG_NFSBOOT 711 The value of these goes into the environment as 712 "ramboot" and "nfsboot" respectively, and can be used 713 as a convenience, when switching between booting from 714 RAM and NFS. 715 716- Pre-Boot Commands: 717 CONFIG_PREBOOT 718 719 When this option is #defined, the existence of the 720 environment variable "preboot" will be checked 721 immediately before starting the CONFIG_BOOTDELAY 722 countdown and/or running the auto-boot command resp. 723 entering interactive mode. 724 725 This feature is especially useful when "preboot" is 726 automatically generated or modified. For an example 727 see the LWMON board specific code: here "preboot" is 728 modified when the user holds down a certain 729 combination of keys on the (special) keyboard when 730 booting the systems 731 732- Serial Download Echo Mode: 733 CONFIG_LOADS_ECHO 734 If defined to 1, all characters received during a 735 serial download (using the "loads" command) are 736 echoed back. This might be needed by some terminal 737 emulations (like "cu"), but may as well just take 738 time on others. This setting #define's the initial 739 value of the "loads_echo" environment variable. 740 741- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined) 742 CONFIG_KGDB_BAUDRATE 743 Select one of the baudrates listed in 744 CONFIG_SYS_BAUDRATE_TABLE, see below. 745 746- Removal of commands 747 If no commands are needed to boot, you can disable 748 CONFIG_CMDLINE to remove them. In this case, the command line 749 will not be available, and when U-Boot wants to execute the 750 boot command (on start-up) it will call board_run_command() 751 instead. This can reduce image size significantly for very 752 simple boot procedures. 753 754- Regular expression support: 755 CONFIG_REGEX 756 If this variable is defined, U-Boot is linked against 757 the SLRE (Super Light Regular Expression) library, 758 which adds regex support to some commands, as for 759 example "env grep" and "setexpr". 760 761- Device tree: 762 CONFIG_OF_CONTROL 763 If this variable is defined, U-Boot will use a device tree 764 to configure its devices, instead of relying on statically 765 compiled #defines in the board file. This option is 766 experimental and only available on a few boards. The device 767 tree is available in the global data as gd->fdt_blob. 768 769 U-Boot needs to get its device tree from somewhere. This can 770 be done using one of the three options below: 771 772 CONFIG_OF_EMBED 773 If this variable is defined, U-Boot will embed a device tree 774 binary in its image. This device tree file should be in the 775 board directory and called <soc>-<board>.dts. The binary file 776 is then picked up in board_init_f() and made available through 777 the global data structure as gd->fdt_blob. 778 779 CONFIG_OF_SEPARATE 780 If this variable is defined, U-Boot will build a device tree 781 binary. It will be called u-boot.dtb. Architecture-specific 782 code will locate it at run-time. Generally this works by: 783 784 cat u-boot.bin u-boot.dtb >image.bin 785 786 and in fact, U-Boot does this for you, creating a file called 787 u-boot-dtb.bin which is useful in the common case. You can 788 still use the individual files if you need something more 789 exotic. 790 791 CONFIG_OF_BOARD 792 If this variable is defined, U-Boot will use the device tree 793 provided by the board at runtime instead of embedding one with 794 the image. Only boards defining board_fdt_blob_setup() support 795 this option (see include/fdtdec.h file). 796 797- Watchdog: 798 CONFIG_WATCHDOG 799 If this variable is defined, it enables watchdog 800 support for the SoC. There must be support in the SoC 801 specific code for a watchdog. For the 8xx 802 CPUs, the SIU Watchdog feature is enabled in the SYPCR 803 register. When supported for a specific SoC is 804 available, then no further board specific code should 805 be needed to use it. 806 807 CONFIG_HW_WATCHDOG 808 When using a watchdog circuitry external to the used 809 SoC, then define this variable and provide board 810 specific code for the "hw_watchdog_reset" function. 811 812 CONFIG_AT91_HW_WDT_TIMEOUT 813 specify the timeout in seconds. default 2 seconds. 814 815- U-Boot Version: 816 CONFIG_VERSION_VARIABLE 817 If this variable is defined, an environment variable 818 named "ver" is created by U-Boot showing the U-Boot 819 version as printed by the "version" command. 820 Any change to this variable will be reverted at the 821 next reset. 822 823- Real-Time Clock: 824 825 When CONFIG_CMD_DATE is selected, the type of the RTC 826 has to be selected, too. Define exactly one of the 827 following options: 828 829 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC 830 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC 831 CONFIG_RTC_MC146818 - use MC146818 RTC 832 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC 833 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC 834 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC 835 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC 836 CONFIG_RTC_DS164x - use Dallas DS164x RTC 837 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC 838 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC 839 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337 840 CONFIG_SYS_RV3029_TCR - enable trickle charger on 841 RV3029 RTC. 842 843 Note that if the RTC uses I2C, then the I2C interface 844 must also be configured. See I2C Support, below. 845 846- GPIO Support: 847 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO 848 849 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of 850 chip-ngpio pairs that tell the PCA953X driver the number of 851 pins supported by a particular chip. 852 853 Note that if the GPIO device uses I2C, then the I2C interface 854 must also be configured. See I2C Support, below. 855 856- I/O tracing: 857 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O 858 accesses and can checksum them or write a list of them out 859 to memory. See the 'iotrace' command for details. This is 860 useful for testing device drivers since it can confirm that 861 the driver behaves the same way before and after a code 862 change. Currently this is supported on sandbox and arm. To 863 add support for your architecture, add '#include <iotrace.h>' 864 to the bottom of arch/<arch>/include/asm/io.h and test. 865 866 Example output from the 'iotrace stats' command is below. 867 Note that if the trace buffer is exhausted, the checksum will 868 still continue to operate. 869 870 iotrace is enabled 871 Start: 10000000 (buffer start address) 872 Size: 00010000 (buffer size) 873 Offset: 00000120 (current buffer offset) 874 Output: 10000120 (start + offset) 875 Count: 00000018 (number of trace records) 876 CRC32: 9526fb66 (CRC32 of all trace records) 877 878- Timestamp Support: 879 880 When CONFIG_TIMESTAMP is selected, the timestamp 881 (date and time) of an image is printed by image 882 commands like bootm or iminfo. This option is 883 automatically enabled when you select CONFIG_CMD_DATE . 884 885- Partition Labels (disklabels) Supported: 886 Zero or more of the following: 887 CONFIG_MAC_PARTITION Apple's MacOS partition table. 888 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc. 889 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the 890 bootloader. Note 2TB partition limit; see 891 disk/part_efi.c 892 CONFIG_MTD_PARTITIONS Memory Technology Device partition table. 893 894 If IDE or SCSI support is enabled (CONFIG_IDE or 895 CONFIG_SCSI) you must configure support for at 896 least one non-MTD partition type as well. 897 898- IDE Reset method: 899 CONFIG_IDE_RESET_ROUTINE - this is defined in several 900 board configurations files but used nowhere! 901 902 CONFIG_IDE_RESET - is this is defined, IDE Reset will 903 be performed by calling the function 904 ide_set_reset(int reset) 905 which has to be defined in a board specific file 906 907- ATAPI Support: 908 CONFIG_ATAPI 909 910 Set this to enable ATAPI support. 911 912- LBA48 Support 913 CONFIG_LBA48 914 915 Set this to enable support for disks larger than 137GB 916 Also look at CONFIG_SYS_64BIT_LBA. 917 Whithout these , LBA48 support uses 32bit variables and will 'only' 918 support disks up to 2.1TB. 919 920 CONFIG_SYS_64BIT_LBA: 921 When enabled, makes the IDE subsystem use 64bit sector addresses. 922 Default is 32bit. 923 924- SCSI Support: 925 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and 926 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID * 927 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the 928 maximum numbers of LUNs, SCSI ID's and target 929 devices. 930 931 The environment variable 'scsidevs' is set to the number of 932 SCSI devices found during the last scan. 933 934- NETWORK Support (PCI): 935 CONFIG_E1000 936 Support for Intel 8254x/8257x gigabit chips. 937 938 CONFIG_E1000_SPI 939 Utility code for direct access to the SPI bus on Intel 8257x. 940 This does not do anything useful unless you set at least one 941 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC. 942 943 CONFIG_E1000_SPI_GENERIC 944 Allow generic access to the SPI bus on the Intel 8257x, for 945 example with the "sspi" command. 946 947 CONFIG_EEPRO100 948 Support for Intel 82557/82559/82559ER chips. 949 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM 950 write routine for first time initialisation. 951 952 CONFIG_TULIP 953 Support for Digital 2114x chips. 954 Optional CONFIG_TULIP_SELECT_MEDIA for board specific 955 modem chip initialisation (KS8761/QS6611). 956 957 CONFIG_NATSEMI 958 Support for National dp83815 chips. 959 960 CONFIG_NS8382X 961 Support for National dp8382[01] gigabit chips. 962 963- NETWORK Support (other): 964 965 CONFIG_DRIVER_AT91EMAC 966 Support for AT91RM9200 EMAC. 967 968 CONFIG_RMII 969 Define this to use reduced MII inteface 970 971 CONFIG_DRIVER_AT91EMAC_QUIET 972 If this defined, the driver is quiet. 973 The driver doen't show link status messages. 974 975 CONFIG_CALXEDA_XGMAC 976 Support for the Calxeda XGMAC device 977 978 CONFIG_LAN91C96 979 Support for SMSC's LAN91C96 chips. 980 981 CONFIG_LAN91C96_USE_32_BIT 982 Define this to enable 32 bit addressing 983 984 CONFIG_SMC91111 985 Support for SMSC's LAN91C111 chip 986 987 CONFIG_SMC91111_BASE 988 Define this to hold the physical address 989 of the device (I/O space) 990 991 CONFIG_SMC_USE_32_BIT 992 Define this if data bus is 32 bits 993 994 CONFIG_SMC_USE_IOFUNCS 995 Define this to use i/o functions instead of macros 996 (some hardware wont work with macros) 997 998 CONFIG_DRIVER_TI_EMAC 999 Support for davinci emac 1000 1001 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT 1002 Define this if you have more then 3 PHYs. 1003 1004 CONFIG_FTGMAC100 1005 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet 1006 1007 CONFIG_FTGMAC100_EGIGA 1008 Define this to use GE link update with gigabit PHY. 1009 Define this if FTGMAC100 is connected to gigabit PHY. 1010 If your system has 10/100 PHY only, it might not occur 1011 wrong behavior. Because PHY usually return timeout or 1012 useless data when polling gigabit status and gigabit 1013 control registers. This behavior won't affect the 1014 correctnessof 10/100 link speed update. 1015 1016 CONFIG_SH_ETHER 1017 Support for Renesas on-chip Ethernet controller 1018 1019 CONFIG_SH_ETHER_USE_PORT 1020 Define the number of ports to be used 1021 1022 CONFIG_SH_ETHER_PHY_ADDR 1023 Define the ETH PHY's address 1024 1025 CONFIG_SH_ETHER_CACHE_WRITEBACK 1026 If this option is set, the driver enables cache flush. 1027 1028- PWM Support: 1029 CONFIG_PWM_IMX 1030 Support for PWM module on the imx6. 1031 1032- TPM Support: 1033 CONFIG_TPM 1034 Support TPM devices. 1035 1036 CONFIG_TPM_TIS_INFINEON 1037 Support for Infineon i2c bus TPM devices. Only one device 1038 per system is supported at this time. 1039 1040 CONFIG_TPM_TIS_I2C_BURST_LIMITATION 1041 Define the burst count bytes upper limit 1042 1043 CONFIG_TPM_ST33ZP24 1044 Support for STMicroelectronics TPM devices. Requires DM_TPM support. 1045 1046 CONFIG_TPM_ST33ZP24_I2C 1047 Support for STMicroelectronics ST33ZP24 I2C devices. 1048 Requires TPM_ST33ZP24 and I2C. 1049 1050 CONFIG_TPM_ST33ZP24_SPI 1051 Support for STMicroelectronics ST33ZP24 SPI devices. 1052 Requires TPM_ST33ZP24 and SPI. 1053 1054 CONFIG_TPM_ATMEL_TWI 1055 Support for Atmel TWI TPM device. Requires I2C support. 1056 1057 CONFIG_TPM_TIS_LPC 1058 Support for generic parallel port TPM devices. Only one device 1059 per system is supported at this time. 1060 1061 CONFIG_TPM_TIS_BASE_ADDRESS 1062 Base address where the generic TPM device is mapped 1063 to. Contemporary x86 systems usually map it at 1064 0xfed40000. 1065 1066 CONFIG_TPM 1067 Define this to enable the TPM support library which provides 1068 functional interfaces to some TPM commands. 1069 Requires support for a TPM device. 1070 1071 CONFIG_TPM_AUTH_SESSIONS 1072 Define this to enable authorized functions in the TPM library. 1073 Requires CONFIG_TPM and CONFIG_SHA1. 1074 1075- USB Support: 1076 At the moment only the UHCI host controller is 1077 supported (PIP405, MIP405); define 1078 CONFIG_USB_UHCI to enable it. 1079 define CONFIG_USB_KEYBOARD to enable the USB Keyboard 1080 and define CONFIG_USB_STORAGE to enable the USB 1081 storage devices. 1082 Note: 1083 Supported are USB Keyboards and USB Floppy drives 1084 (TEAC FD-05PUB). 1085 1086 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the 1087 txfilltuning field in the EHCI controller on reset. 1088 1089 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2 1090 HW module registers. 1091 1092- USB Device: 1093 Define the below if you wish to use the USB console. 1094 Once firmware is rebuilt from a serial console issue the 1095 command "setenv stdin usbtty; setenv stdout usbtty" and 1096 attach your USB cable. The Unix command "dmesg" should print 1097 it has found a new device. The environment variable usbtty 1098 can be set to gserial or cdc_acm to enable your device to 1099 appear to a USB host as a Linux gserial device or a 1100 Common Device Class Abstract Control Model serial device. 1101 If you select usbtty = gserial you should be able to enumerate 1102 a Linux host by 1103 # modprobe usbserial vendor=0xVendorID product=0xProductID 1104 else if using cdc_acm, simply setting the environment 1105 variable usbtty to be cdc_acm should suffice. The following 1106 might be defined in YourBoardName.h 1107 1108 CONFIG_USB_DEVICE 1109 Define this to build a UDC device 1110 1111 CONFIG_USB_TTY 1112 Define this to have a tty type of device available to 1113 talk to the UDC device 1114 1115 CONFIG_USBD_HS 1116 Define this to enable the high speed support for usb 1117 device and usbtty. If this feature is enabled, a routine 1118 int is_usbd_high_speed(void) 1119 also needs to be defined by the driver to dynamically poll 1120 whether the enumeration has succeded at high speed or full 1121 speed. 1122 1123 CONFIG_SYS_CONSOLE_IS_IN_ENV 1124 Define this if you want stdin, stdout &/or stderr to 1125 be set to usbtty. 1126 1127 If you have a USB-IF assigned VendorID then you may wish to 1128 define your own vendor specific values either in BoardName.h 1129 or directly in usbd_vendor_info.h. If you don't define 1130 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME, 1131 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot 1132 should pretend to be a Linux device to it's target host. 1133 1134 CONFIG_USBD_MANUFACTURER 1135 Define this string as the name of your company for 1136 - CONFIG_USBD_MANUFACTURER "my company" 1137 1138 CONFIG_USBD_PRODUCT_NAME 1139 Define this string as the name of your product 1140 - CONFIG_USBD_PRODUCT_NAME "acme usb device" 1141 1142 CONFIG_USBD_VENDORID 1143 Define this as your assigned Vendor ID from the USB 1144 Implementors Forum. This *must* be a genuine Vendor ID 1145 to avoid polluting the USB namespace. 1146 - CONFIG_USBD_VENDORID 0xFFFF 1147 1148 CONFIG_USBD_PRODUCTID 1149 Define this as the unique Product ID 1150 for your device 1151 - CONFIG_USBD_PRODUCTID 0xFFFF 1152 1153- ULPI Layer Support: 1154 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via 1155 the generic ULPI layer. The generic layer accesses the ULPI PHY 1156 via the platform viewport, so you need both the genric layer and 1157 the viewport enabled. Currently only Chipidea/ARC based 1158 viewport is supported. 1159 To enable the ULPI layer support, define CONFIG_USB_ULPI and 1160 CONFIG_USB_ULPI_VIEWPORT in your board configuration file. 1161 If your ULPI phy needs a different reference clock than the 1162 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to 1163 the appropriate value in Hz. 1164 1165- MMC Support: 1166 The MMC controller on the Intel PXA is supported. To 1167 enable this define CONFIG_MMC. The MMC can be 1168 accessed from the boot prompt by mapping the device 1169 to physical memory similar to flash. Command line is 1170 enabled with CONFIG_CMD_MMC. The MMC driver also works with 1171 the FAT fs. This is enabled with CONFIG_CMD_FAT. 1172 1173 CONFIG_SH_MMCIF 1174 Support for Renesas on-chip MMCIF controller 1175 1176 CONFIG_SH_MMCIF_ADDR 1177 Define the base address of MMCIF registers 1178 1179 CONFIG_SH_MMCIF_CLK 1180 Define the clock frequency for MMCIF 1181 1182 CONFIG_SUPPORT_EMMC_BOOT 1183 Enable some additional features of the eMMC boot partitions. 1184 1185 CONFIG_SUPPORT_EMMC_RPMB 1186 Enable the commands for reading, writing and programming the 1187 key for the Replay Protection Memory Block partition in eMMC. 1188 1189- USB Device Firmware Update (DFU) class support: 1190 CONFIG_DFU_OVER_USB 1191 This enables the USB portion of the DFU USB class 1192 1193 CONFIG_DFU_MMC 1194 This enables support for exposing (e)MMC devices via DFU. 1195 1196 CONFIG_DFU_NAND 1197 This enables support for exposing NAND devices via DFU. 1198 1199 CONFIG_DFU_RAM 1200 This enables support for exposing RAM via DFU. 1201 Note: DFU spec refer to non-volatile memory usage, but 1202 allow usages beyond the scope of spec - here RAM usage, 1203 one that would help mostly the developer. 1204 1205 CONFIG_SYS_DFU_DATA_BUF_SIZE 1206 Dfu transfer uses a buffer before writing data to the 1207 raw storage device. Make the size (in bytes) of this buffer 1208 configurable. The size of this buffer is also configurable 1209 through the "dfu_bufsiz" environment variable. 1210 1211 CONFIG_SYS_DFU_MAX_FILE_SIZE 1212 When updating files rather than the raw storage device, 1213 we use a static buffer to copy the file into and then write 1214 the buffer once we've been given the whole file. Define 1215 this to the maximum filesize (in bytes) for the buffer. 1216 Default is 4 MiB if undefined. 1217 1218 DFU_DEFAULT_POLL_TIMEOUT 1219 Poll timeout [ms], is the timeout a device can send to the 1220 host. The host must wait for this timeout before sending 1221 a subsequent DFU_GET_STATUS request to the device. 1222 1223 DFU_MANIFEST_POLL_TIMEOUT 1224 Poll timeout [ms], which the device sends to the host when 1225 entering dfuMANIFEST state. Host waits this timeout, before 1226 sending again an USB request to the device. 1227 1228- Journaling Flash filesystem support: 1229 CONFIG_JFFS2_NAND 1230 Define these for a default partition on a NAND device 1231 1232 CONFIG_SYS_JFFS2_FIRST_SECTOR, 1233 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS 1234 Define these for a default partition on a NOR device 1235 1236- Keyboard Support: 1237 See Kconfig help for available keyboard drivers. 1238 1239 CONFIG_KEYBOARD 1240 1241 Define this to enable a custom keyboard support. 1242 This simply calls drv_keyboard_init() which must be 1243 defined in your board-specific files. This option is deprecated 1244 and is only used by novena. For new boards, use driver model 1245 instead. 1246 1247- Video support: 1248 CONFIG_FSL_DIU_FB 1249 Enable the Freescale DIU video driver. Reference boards for 1250 SOCs that have a DIU should define this macro to enable DIU 1251 support, and should also define these other macros: 1252 1253 CONFIG_SYS_DIU_ADDR 1254 CONFIG_VIDEO 1255 CONFIG_CFB_CONSOLE 1256 CONFIG_VIDEO_SW_CURSOR 1257 CONFIG_VGA_AS_SINGLE_DEVICE 1258 CONFIG_VIDEO_LOGO 1259 CONFIG_VIDEO_BMP_LOGO 1260 1261 The DIU driver will look for the 'video-mode' environment 1262 variable, and if defined, enable the DIU as a console during 1263 boot. See the documentation file doc/README.video for a 1264 description of this variable. 1265 1266- LCD Support: CONFIG_LCD 1267 1268 Define this to enable LCD support (for output to LCD 1269 display); also select one of the supported displays 1270 by defining one of these: 1271 1272 CONFIG_ATMEL_LCD: 1273 1274 HITACHI TX09D70VM1CCA, 3.5", 240x320. 1275 1276 CONFIG_NEC_NL6448AC33: 1277 1278 NEC NL6448AC33-18. Active, color, single scan. 1279 1280 CONFIG_NEC_NL6448BC20 1281 1282 NEC NL6448BC20-08. 6.5", 640x480. 1283 Active, color, single scan. 1284 1285 CONFIG_NEC_NL6448BC33_54 1286 1287 NEC NL6448BC33-54. 10.4", 640x480. 1288 Active, color, single scan. 1289 1290 CONFIG_SHARP_16x9 1291 1292 Sharp 320x240. Active, color, single scan. 1293 It isn't 16x9, and I am not sure what it is. 1294 1295 CONFIG_SHARP_LQ64D341 1296 1297 Sharp LQ64D341 display, 640x480. 1298 Active, color, single scan. 1299 1300 CONFIG_HLD1045 1301 1302 HLD1045 display, 640x480. 1303 Active, color, single scan. 1304 1305 CONFIG_OPTREX_BW 1306 1307 Optrex CBL50840-2 NF-FW 99 22 M5 1308 or 1309 Hitachi LMG6912RPFC-00T 1310 or 1311 Hitachi SP14Q002 1312 1313 320x240. Black & white. 1314 1315 CONFIG_LCD_ALIGNMENT 1316 1317 Normally the LCD is page-aligned (typically 4KB). If this is 1318 defined then the LCD will be aligned to this value instead. 1319 For ARM it is sometimes useful to use MMU_SECTION_SIZE 1320 here, since it is cheaper to change data cache settings on 1321 a per-section basis. 1322 1323 1324 CONFIG_LCD_ROTATION 1325 1326 Sometimes, for example if the display is mounted in portrait 1327 mode or even if it's mounted landscape but rotated by 180degree, 1328 we need to rotate our content of the display relative to the 1329 framebuffer, so that user can read the messages which are 1330 printed out. 1331 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be 1332 initialized with a given rotation from "vl_rot" out of 1333 "vidinfo_t" which is provided by the board specific code. 1334 The value for vl_rot is coded as following (matching to 1335 fbcon=rotate:<n> linux-kernel commandline): 1336 0 = no rotation respectively 0 degree 1337 1 = 90 degree rotation 1338 2 = 180 degree rotation 1339 3 = 270 degree rotation 1340 1341 If CONFIG_LCD_ROTATION is not defined, the console will be 1342 initialized with 0degree rotation. 1343 1344 CONFIG_LCD_BMP_RLE8 1345 1346 Support drawing of RLE8-compressed bitmaps on the LCD. 1347 1348 CONFIG_I2C_EDID 1349 1350 Enables an 'i2c edid' command which can read EDID 1351 information over I2C from an attached LCD display. 1352 1353- Splash Screen Support: CONFIG_SPLASH_SCREEN 1354 1355 If this option is set, the environment is checked for 1356 a variable "splashimage". If found, the usual display 1357 of logo, copyright and system information on the LCD 1358 is suppressed and the BMP image at the address 1359 specified in "splashimage" is loaded instead. The 1360 console is redirected to the "nulldev", too. This 1361 allows for a "silent" boot where a splash screen is 1362 loaded very quickly after power-on. 1363 1364 CONFIG_SPLASHIMAGE_GUARD 1365 1366 If this option is set, then U-Boot will prevent the environment 1367 variable "splashimage" from being set to a problematic address 1368 (see doc/README.displaying-bmps). 1369 This option is useful for targets where, due to alignment 1370 restrictions, an improperly aligned BMP image will cause a data 1371 abort. If you think you will not have problems with unaligned 1372 accesses (for example because your toolchain prevents them) 1373 there is no need to set this option. 1374 1375 CONFIG_SPLASH_SCREEN_ALIGN 1376 1377 If this option is set the splash image can be freely positioned 1378 on the screen. Environment variable "splashpos" specifies the 1379 position as "x,y". If a positive number is given it is used as 1380 number of pixel from left/top. If a negative number is given it 1381 is used as number of pixel from right/bottom. You can also 1382 specify 'm' for centering the image. 1383 1384 Example: 1385 setenv splashpos m,m 1386 => image at center of screen 1387 1388 setenv splashpos 30,20 1389 => image at x = 30 and y = 20 1390 1391 setenv splashpos -10,m 1392 => vertically centered image 1393 at x = dspWidth - bmpWidth - 9 1394 1395- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP 1396 1397 If this option is set, additionally to standard BMP 1398 images, gzipped BMP images can be displayed via the 1399 splashscreen support or the bmp command. 1400 1401- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8 1402 1403 If this option is set, 8-bit RLE compressed BMP images 1404 can be displayed via the splashscreen support or the 1405 bmp command. 1406 1407- Compression support: 1408 CONFIG_GZIP 1409 1410 Enabled by default to support gzip compressed images. 1411 1412 CONFIG_BZIP2 1413 1414 If this option is set, support for bzip2 compressed 1415 images is included. If not, only uncompressed and gzip 1416 compressed images are supported. 1417 1418 NOTE: the bzip2 algorithm requires a lot of RAM, so 1419 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should 1420 be at least 4MB. 1421 1422- MII/PHY support: 1423 CONFIG_PHY_CLOCK_FREQ (ppc4xx) 1424 1425 The clock frequency of the MII bus 1426 1427 CONFIG_PHY_RESET_DELAY 1428 1429 Some PHY like Intel LXT971A need extra delay after 1430 reset before any MII register access is possible. 1431 For such PHY, set this option to the usec delay 1432 required. (minimum 300usec for LXT971A) 1433 1434 CONFIG_PHY_CMD_DELAY (ppc4xx) 1435 1436 Some PHY like Intel LXT971A need extra delay after 1437 command issued before MII status register can be read 1438 1439- IP address: 1440 CONFIG_IPADDR 1441 1442 Define a default value for the IP address to use for 1443 the default Ethernet interface, in case this is not 1444 determined through e.g. bootp. 1445 (Environment variable "ipaddr") 1446 1447- Server IP address: 1448 CONFIG_SERVERIP 1449 1450 Defines a default value for the IP address of a TFTP 1451 server to contact when using the "tftboot" command. 1452 (Environment variable "serverip") 1453 1454 CONFIG_KEEP_SERVERADDR 1455 1456 Keeps the server's MAC address, in the env 'serveraddr' 1457 for passing to bootargs (like Linux's netconsole option) 1458 1459- Gateway IP address: 1460 CONFIG_GATEWAYIP 1461 1462 Defines a default value for the IP address of the 1463 default router where packets to other networks are 1464 sent to. 1465 (Environment variable "gatewayip") 1466 1467- Subnet mask: 1468 CONFIG_NETMASK 1469 1470 Defines a default value for the subnet mask (or 1471 routing prefix) which is used to determine if an IP 1472 address belongs to the local subnet or needs to be 1473 forwarded through a router. 1474 (Environment variable "netmask") 1475 1476- Multicast TFTP Mode: 1477 CONFIG_MCAST_TFTP 1478 1479 Defines whether you want to support multicast TFTP as per 1480 rfc-2090; for example to work with atftp. Lets lots of targets 1481 tftp down the same boot image concurrently. Note: the Ethernet 1482 driver in use must provide a function: mcast() to join/leave a 1483 multicast group. 1484 1485- BOOTP Recovery Mode: 1486 CONFIG_BOOTP_RANDOM_DELAY 1487 1488 If you have many targets in a network that try to 1489 boot using BOOTP, you may want to avoid that all 1490 systems send out BOOTP requests at precisely the same 1491 moment (which would happen for instance at recovery 1492 from a power failure, when all systems will try to 1493 boot, thus flooding the BOOTP server. Defining 1494 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be 1495 inserted before sending out BOOTP requests. The 1496 following delays are inserted then: 1497 1498 1st BOOTP request: delay 0 ... 1 sec 1499 2nd BOOTP request: delay 0 ... 2 sec 1500 3rd BOOTP request: delay 0 ... 4 sec 1501 4th and following 1502 BOOTP requests: delay 0 ... 8 sec 1503 1504 CONFIG_BOOTP_ID_CACHE_SIZE 1505 1506 BOOTP packets are uniquely identified using a 32-bit ID. The 1507 server will copy the ID from client requests to responses and 1508 U-Boot will use this to determine if it is the destination of 1509 an incoming response. Some servers will check that addresses 1510 aren't in use before handing them out (usually using an ARP 1511 ping) and therefore take up to a few hundred milliseconds to 1512 respond. Network congestion may also influence the time it 1513 takes for a response to make it back to the client. If that 1514 time is too long, U-Boot will retransmit requests. In order 1515 to allow earlier responses to still be accepted after these 1516 retransmissions, U-Boot's BOOTP client keeps a small cache of 1517 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this 1518 cache. The default is to keep IDs for up to four outstanding 1519 requests. Increasing this will allow U-Boot to accept offers 1520 from a BOOTP client in networks with unusually high latency. 1521 1522- DHCP Advanced Options: 1523 You can fine tune the DHCP functionality by defining 1524 CONFIG_BOOTP_* symbols: 1525 1526 CONFIG_BOOTP_NISDOMAIN 1527 CONFIG_BOOTP_BOOTFILESIZE 1528 CONFIG_BOOTP_SEND_HOSTNAME 1529 CONFIG_BOOTP_NTPSERVER 1530 CONFIG_BOOTP_TIMEOFFSET 1531 CONFIG_BOOTP_VENDOREX 1532 CONFIG_BOOTP_MAY_FAIL 1533 1534 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip 1535 environment variable, not the BOOTP server. 1536 1537 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found 1538 after the configured retry count, the call will fail 1539 instead of starting over. This can be used to fail over 1540 to Link-local IP address configuration if the DHCP server 1541 is not available. 1542 1543 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable 1544 to do a dynamic update of a DNS server. To do this, they 1545 need the hostname of the DHCP requester. 1546 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content 1547 of the "hostname" environment variable is passed as 1548 option 12 to the DHCP server. 1549 1550 CONFIG_BOOTP_DHCP_REQUEST_DELAY 1551 1552 A 32bit value in microseconds for a delay between 1553 receiving a "DHCP Offer" and sending the "DHCP Request". 1554 This fixes a problem with certain DHCP servers that don't 1555 respond 100% of the time to a "DHCP request". E.g. On an 1556 AT91RM9200 processor running at 180MHz, this delay needed 1557 to be *at least* 15,000 usec before a Windows Server 2003 1558 DHCP server would reply 100% of the time. I recommend at 1559 least 50,000 usec to be safe. The alternative is to hope 1560 that one of the retries will be successful but note that 1561 the DHCP timeout and retry process takes a longer than 1562 this delay. 1563 1564 - Link-local IP address negotiation: 1565 Negotiate with other link-local clients on the local network 1566 for an address that doesn't require explicit configuration. 1567 This is especially useful if a DHCP server cannot be guaranteed 1568 to exist in all environments that the device must operate. 1569 1570 See doc/README.link-local for more information. 1571 1572 - MAC address from environment variables 1573 1574 FDT_SEQ_MACADDR_FROM_ENV 1575 1576 Fix-up device tree with MAC addresses fetched sequentially from 1577 environment variables. This config work on assumption that 1578 non-usable ethernet node of device-tree are either not present 1579 or their status has been marked as "disabled". 1580 1581 - CDP Options: 1582 CONFIG_CDP_DEVICE_ID 1583 1584 The device id used in CDP trigger frames. 1585 1586 CONFIG_CDP_DEVICE_ID_PREFIX 1587 1588 A two character string which is prefixed to the MAC address 1589 of the device. 1590 1591 CONFIG_CDP_PORT_ID 1592 1593 A printf format string which contains the ascii name of 1594 the port. Normally is set to "eth%d" which sets 1595 eth0 for the first Ethernet, eth1 for the second etc. 1596 1597 CONFIG_CDP_CAPABILITIES 1598 1599 A 32bit integer which indicates the device capabilities; 1600 0x00000010 for a normal host which does not forwards. 1601 1602 CONFIG_CDP_VERSION 1603 1604 An ascii string containing the version of the software. 1605 1606 CONFIG_CDP_PLATFORM 1607 1608 An ascii string containing the name of the platform. 1609 1610 CONFIG_CDP_TRIGGER 1611 1612 A 32bit integer sent on the trigger. 1613 1614 CONFIG_CDP_POWER_CONSUMPTION 1615 1616 A 16bit integer containing the power consumption of the 1617 device in .1 of milliwatts. 1618 1619 CONFIG_CDP_APPLIANCE_VLAN_TYPE 1620 1621 A byte containing the id of the VLAN. 1622 1623- Status LED: CONFIG_LED_STATUS 1624 1625 Several configurations allow to display the current 1626 status using a LED. For instance, the LED will blink 1627 fast while running U-Boot code, stop blinking as 1628 soon as a reply to a BOOTP request was received, and 1629 start blinking slow once the Linux kernel is running 1630 (supported by a status LED driver in the Linux 1631 kernel). Defining CONFIG_LED_STATUS enables this 1632 feature in U-Boot. 1633 1634 Additional options: 1635 1636 CONFIG_LED_STATUS_GPIO 1637 The status LED can be connected to a GPIO pin. 1638 In such cases, the gpio_led driver can be used as a 1639 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO 1640 to include the gpio_led driver in the U-Boot binary. 1641 1642 CONFIG_GPIO_LED_INVERTED_TABLE 1643 Some GPIO connected LEDs may have inverted polarity in which 1644 case the GPIO high value corresponds to LED off state and 1645 GPIO low value corresponds to LED on state. 1646 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined 1647 with a list of GPIO LEDs that have inverted polarity. 1648 1649- I2C Support: CONFIG_SYS_I2C 1650 1651 This enable the NEW i2c subsystem, and will allow you to use 1652 i2c commands at the u-boot command line (as long as you set 1653 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c 1654 based realtime clock chips or other i2c devices. See 1655 common/cmd_i2c.c for a description of the command line 1656 interface. 1657 1658 ported i2c driver to the new framework: 1659 - drivers/i2c/soft_i2c.c: 1660 - activate first bus with CONFIG_SYS_I2C_SOFT define 1661 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE 1662 for defining speed and slave address 1663 - activate second bus with I2C_SOFT_DECLARATIONS2 define 1664 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2 1665 for defining speed and slave address 1666 - activate third bus with I2C_SOFT_DECLARATIONS3 define 1667 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3 1668 for defining speed and slave address 1669 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define 1670 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4 1671 for defining speed and slave address 1672 1673 - drivers/i2c/fsl_i2c.c: 1674 - activate i2c driver with CONFIG_SYS_I2C_FSL 1675 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register 1676 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and 1677 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first 1678 bus. 1679 - If your board supports a second fsl i2c bus, define 1680 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset 1681 CONFIG_SYS_FSL_I2C2_SPEED for the speed and 1682 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the 1683 second bus. 1684 1685 - drivers/i2c/tegra_i2c.c: 1686 - activate this driver with CONFIG_SYS_I2C_TEGRA 1687 - This driver adds 4 i2c buses with a fix speed from 1688 100000 and the slave addr 0! 1689 1690 - drivers/i2c/ppc4xx_i2c.c 1691 - activate this driver with CONFIG_SYS_I2C_PPC4XX 1692 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0 1693 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1 1694 1695 - drivers/i2c/i2c_mxc.c 1696 - activate this driver with CONFIG_SYS_I2C_MXC 1697 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1 1698 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2 1699 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3 1700 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4 1701 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED 1702 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE 1703 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED 1704 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE 1705 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED 1706 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE 1707 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED 1708 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE 1709 If those defines are not set, default value is 100000 1710 for speed, and 0 for slave. 1711 1712 - drivers/i2c/rcar_i2c.c: 1713 - activate this driver with CONFIG_SYS_I2C_RCAR 1714 - This driver adds 4 i2c buses 1715 1716 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0 1717 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0 1718 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1 1719 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1 1720 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2 1721 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2 1722 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3 1723 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3 1724 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses 1725 1726 - drivers/i2c/sh_i2c.c: 1727 - activate this driver with CONFIG_SYS_I2C_SH 1728 - This driver adds from 2 to 5 i2c buses 1729 1730 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0 1731 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0 1732 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1 1733 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1 1734 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2 1735 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2 1736 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3 1737 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3 1738 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4 1739 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4 1740 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses 1741 1742 - drivers/i2c/omap24xx_i2c.c 1743 - activate this driver with CONFIG_SYS_I2C_OMAP24XX 1744 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0 1745 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0 1746 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1 1747 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1 1748 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2 1749 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2 1750 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3 1751 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3 1752 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4 1753 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4 1754 1755 - drivers/i2c/zynq_i2c.c 1756 - activate this driver with CONFIG_SYS_I2C_ZYNQ 1757 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting 1758 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr 1759 1760 - drivers/i2c/s3c24x0_i2c.c: 1761 - activate this driver with CONFIG_SYS_I2C_S3C24X0 1762 - This driver adds i2c buses (11 for Exynos5250, Exynos5420 1763 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung) 1764 with a fix speed from 100000 and the slave addr 0! 1765 1766 - drivers/i2c/ihs_i2c.c 1767 - activate this driver with CONFIG_SYS_I2C_IHS 1768 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0 1769 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0 1770 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0 1771 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1 1772 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1 1773 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1 1774 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2 1775 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2 1776 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2 1777 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3 1778 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3 1779 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3 1780 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL 1781 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1 1782 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1 1783 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1 1784 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1 1785 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1 1786 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1 1787 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1 1788 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1 1789 1790 additional defines: 1791 1792 CONFIG_SYS_NUM_I2C_BUSES 1793 Hold the number of i2c buses you want to use. 1794 1795 CONFIG_SYS_I2C_DIRECT_BUS 1796 define this, if you don't use i2c muxes on your hardware. 1797 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can 1798 omit this define. 1799 1800 CONFIG_SYS_I2C_MAX_HOPS 1801 define how many muxes are maximal consecutively connected 1802 on one i2c bus. If you not use i2c muxes, omit this 1803 define. 1804 1805 CONFIG_SYS_I2C_BUSES 1806 hold a list of buses you want to use, only used if 1807 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example 1808 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and 1809 CONFIG_SYS_NUM_I2C_BUSES = 9: 1810 1811 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \ 1812 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \ 1813 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \ 1814 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \ 1815 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \ 1816 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \ 1817 {1, {I2C_NULL_HOP}}, \ 1818 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \ 1819 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \ 1820 } 1821 1822 which defines 1823 bus 0 on adapter 0 without a mux 1824 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1 1825 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2 1826 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3 1827 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4 1828 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5 1829 bus 6 on adapter 1 without a mux 1830 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1 1831 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2 1832 1833 If you do not have i2c muxes on your board, omit this define. 1834 1835- Legacy I2C Support: 1836 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT) 1837 then the following macros need to be defined (examples are 1838 from include/configs/lwmon.h): 1839 1840 I2C_INIT 1841 1842 (Optional). Any commands necessary to enable the I2C 1843 controller or configure ports. 1844 1845 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL) 1846 1847 I2C_ACTIVE 1848 1849 The code necessary to make the I2C data line active 1850 (driven). If the data line is open collector, this 1851 define can be null. 1852 1853 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA) 1854 1855 I2C_TRISTATE 1856 1857 The code necessary to make the I2C data line tri-stated 1858 (inactive). If the data line is open collector, this 1859 define can be null. 1860 1861 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA) 1862 1863 I2C_READ 1864 1865 Code that returns true if the I2C data line is high, 1866 false if it is low. 1867 1868 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0) 1869 1870 I2C_SDA(bit) 1871 1872 If <bit> is true, sets the I2C data line high. If it 1873 is false, it clears it (low). 1874 1875 eg: #define I2C_SDA(bit) \ 1876 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \ 1877 else immr->im_cpm.cp_pbdat &= ~PB_SDA 1878 1879 I2C_SCL(bit) 1880 1881 If <bit> is true, sets the I2C clock line high. If it 1882 is false, it clears it (low). 1883 1884 eg: #define I2C_SCL(bit) \ 1885 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \ 1886 else immr->im_cpm.cp_pbdat &= ~PB_SCL 1887 1888 I2C_DELAY 1889 1890 This delay is invoked four times per clock cycle so this 1891 controls the rate of data transfer. The data rate thus 1892 is 1 / (I2C_DELAY * 4). Often defined to be something 1893 like: 1894 1895 #define I2C_DELAY udelay(2) 1896 1897 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA 1898 1899 If your arch supports the generic GPIO framework (asm/gpio.h), 1900 then you may alternatively define the two GPIOs that are to be 1901 used as SCL / SDA. Any of the previous I2C_xxx macros will 1902 have GPIO-based defaults assigned to them as appropriate. 1903 1904 You should define these to the GPIO value as given directly to 1905 the generic GPIO functions. 1906 1907 CONFIG_SYS_I2C_INIT_BOARD 1908 1909 When a board is reset during an i2c bus transfer 1910 chips might think that the current transfer is still 1911 in progress. On some boards it is possible to access 1912 the i2c SCLK line directly, either by using the 1913 processor pin as a GPIO or by having a second pin 1914 connected to the bus. If this option is defined a 1915 custom i2c_init_board() routine in boards/xxx/board.c 1916 is run early in the boot sequence. 1917 1918 CONFIG_I2C_MULTI_BUS 1919 1920 This option allows the use of multiple I2C buses, each of which 1921 must have a controller. At any point in time, only one bus is 1922 active. To switch to a different bus, use the 'i2c dev' command. 1923 Note that bus numbering is zero-based. 1924 1925 CONFIG_SYS_I2C_NOPROBES 1926 1927 This option specifies a list of I2C devices that will be skipped 1928 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS 1929 is set, specify a list of bus-device pairs. Otherwise, specify 1930 a 1D array of device addresses 1931 1932 e.g. 1933 #undef CONFIG_I2C_MULTI_BUS 1934 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68} 1935 1936 will skip addresses 0x50 and 0x68 on a board with one I2C bus 1937 1938 #define CONFIG_I2C_MULTI_BUS 1939 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} 1940 1941 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 1942 1943 CONFIG_SYS_SPD_BUS_NUM 1944 1945 If defined, then this indicates the I2C bus number for DDR SPD. 1946 If not defined, then U-Boot assumes that SPD is on I2C bus 0. 1947 1948 CONFIG_SYS_RTC_BUS_NUM 1949 1950 If defined, then this indicates the I2C bus number for the RTC. 1951 If not defined, then U-Boot assumes that RTC is on I2C bus 0. 1952 1953 CONFIG_SOFT_I2C_READ_REPEATED_START 1954 1955 defining this will force the i2c_read() function in 1956 the soft_i2c driver to perform an I2C repeated start 1957 between writing the address pointer and reading the 1958 data. If this define is omitted the default behaviour 1959 of doing a stop-start sequence will be used. Most I2C 1960 devices can use either method, but some require one or 1961 the other. 1962 1963- SPI Support: CONFIG_SPI 1964 1965 Enables SPI driver (so far only tested with 1966 SPI EEPROM, also an instance works with Crystal A/D and 1967 D/As on the SACSng board) 1968 1969 CONFIG_SOFT_SPI 1970 1971 Enables a software (bit-bang) SPI driver rather than 1972 using hardware support. This is a general purpose 1973 driver that only requires three general I/O port pins 1974 (two outputs, one input) to function. If this is 1975 defined, the board configuration must define several 1976 SPI configuration items (port pins to use, etc). For 1977 an example, see include/configs/sacsng.h. 1978 1979 CONFIG_HARD_SPI 1980 1981 Enables a hardware SPI driver for general-purpose reads 1982 and writes. As with CONFIG_SOFT_SPI, the board configuration 1983 must define a list of chip-select function pointers. 1984 Currently supported on some MPC8xxx processors. For an 1985 example, see include/configs/mpc8349emds.h. 1986 1987 CONFIG_SYS_SPI_MXC_WAIT 1988 Timeout for waiting until spi transfer completed. 1989 default: (CONFIG_SYS_HZ/100) /* 10 ms */ 1990 1991- FPGA Support: CONFIG_FPGA 1992 1993 Enables FPGA subsystem. 1994 1995 CONFIG_FPGA_<vendor> 1996 1997 Enables support for specific chip vendors. 1998 (ALTERA, XILINX) 1999 2000 CONFIG_FPGA_<family> 2001 2002 Enables support for FPGA family. 2003 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX) 2004 2005 CONFIG_FPGA_COUNT 2006 2007 Specify the number of FPGA devices to support. 2008 2009 CONFIG_SYS_FPGA_PROG_FEEDBACK 2010 2011 Enable printing of hash marks during FPGA configuration. 2012 2013 CONFIG_SYS_FPGA_CHECK_BUSY 2014 2015 Enable checks on FPGA configuration interface busy 2016 status by the configuration function. This option 2017 will require a board or device specific function to 2018 be written. 2019 2020 CONFIG_FPGA_DELAY 2021 2022 If defined, a function that provides delays in the FPGA 2023 configuration driver. 2024 2025 CONFIG_SYS_FPGA_CHECK_CTRLC 2026 Allow Control-C to interrupt FPGA configuration 2027 2028 CONFIG_SYS_FPGA_CHECK_ERROR 2029 2030 Check for configuration errors during FPGA bitfile 2031 loading. For example, abort during Virtex II 2032 configuration if the INIT_B line goes low (which 2033 indicated a CRC error). 2034 2035 CONFIG_SYS_FPGA_WAIT_INIT 2036 2037 Maximum time to wait for the INIT_B line to de-assert 2038 after PROB_B has been de-asserted during a Virtex II 2039 FPGA configuration sequence. The default time is 500 2040 ms. 2041 2042 CONFIG_SYS_FPGA_WAIT_BUSY 2043 2044 Maximum time to wait for BUSY to de-assert during 2045 Virtex II FPGA configuration. The default is 5 ms. 2046 2047 CONFIG_SYS_FPGA_WAIT_CONFIG 2048 2049 Time to wait after FPGA configuration. The default is 2050 200 ms. 2051 2052- Configuration Management: 2053 CONFIG_BUILD_TARGET 2054 2055 Some SoCs need special image types (e.g. U-Boot binary 2056 with a special header) as build targets. By defining 2057 CONFIG_BUILD_TARGET in the SoC / board header, this 2058 special image will be automatically built upon calling 2059 make / buildman. 2060 2061 CONFIG_IDENT_STRING 2062 2063 If defined, this string will be added to the U-Boot 2064 version information (U_BOOT_VERSION) 2065 2066- Vendor Parameter Protection: 2067 2068 U-Boot considers the values of the environment 2069 variables "serial#" (Board Serial Number) and 2070 "ethaddr" (Ethernet Address) to be parameters that 2071 are set once by the board vendor / manufacturer, and 2072 protects these variables from casual modification by 2073 the user. Once set, these variables are read-only, 2074 and write or delete attempts are rejected. You can 2075 change this behaviour: 2076 2077 If CONFIG_ENV_OVERWRITE is #defined in your config 2078 file, the write protection for vendor parameters is 2079 completely disabled. Anybody can change or delete 2080 these parameters. 2081 2082 Alternatively, if you define _both_ an ethaddr in the 2083 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default 2084 Ethernet address is installed in the environment, 2085 which can be changed exactly ONCE by the user. [The 2086 serial# is unaffected by this, i. e. it remains 2087 read-only.] 2088 2089 The same can be accomplished in a more flexible way 2090 for any variable by configuring the type of access 2091 to allow for those variables in the ".flags" variable 2092 or define CONFIG_ENV_FLAGS_LIST_STATIC. 2093 2094- Protected RAM: 2095 CONFIG_PRAM 2096 2097 Define this variable to enable the reservation of 2098 "protected RAM", i. e. RAM which is not overwritten 2099 by U-Boot. Define CONFIG_PRAM to hold the number of 2100 kB you want to reserve for pRAM. You can overwrite 2101 this default value by defining an environment 2102 variable "pram" to the number of kB you want to 2103 reserve. Note that the board info structure will 2104 still show the full amount of RAM. If pRAM is 2105 reserved, a new environment variable "mem" will 2106 automatically be defined to hold the amount of 2107 remaining RAM in a form that can be passed as boot 2108 argument to Linux, for instance like that: 2109 2110 setenv bootargs ... mem=\${mem} 2111 saveenv 2112 2113 This way you can tell Linux not to use this memory, 2114 either, which results in a memory region that will 2115 not be affected by reboots. 2116 2117 *WARNING* If your board configuration uses automatic 2118 detection of the RAM size, you must make sure that 2119 this memory test is non-destructive. So far, the 2120 following board configurations are known to be 2121 "pRAM-clean": 2122 2123 IVMS8, IVML24, SPD8xx, 2124 HERMES, IP860, RPXlite, LWMON, 2125 FLAGADM 2126 2127- Access to physical memory region (> 4GB) 2128 Some basic support is provided for operations on memory not 2129 normally accessible to U-Boot - e.g. some architectures 2130 support access to more than 4GB of memory on 32-bit 2131 machines using physical address extension or similar. 2132 Define CONFIG_PHYSMEM to access this basic support, which 2133 currently only supports clearing the memory. 2134 2135- Error Recovery: 2136 CONFIG_NET_RETRY_COUNT 2137 2138 This variable defines the number of retries for 2139 network operations like ARP, RARP, TFTP, or BOOTP 2140 before giving up the operation. If not defined, a 2141 default value of 5 is used. 2142 2143 CONFIG_ARP_TIMEOUT 2144 2145 Timeout waiting for an ARP reply in milliseconds. 2146 2147 CONFIG_NFS_TIMEOUT 2148 2149 Timeout in milliseconds used in NFS protocol. 2150 If you encounter "ERROR: Cannot umount" in nfs command, 2151 try longer timeout such as 2152 #define CONFIG_NFS_TIMEOUT 10000UL 2153 2154- Command Interpreter: 2155 CONFIG_SYS_PROMPT_HUSH_PS2 2156 2157 This defines the secondary prompt string, which is 2158 printed when the command interpreter needs more input 2159 to complete a command. Usually "> ". 2160 2161 Note: 2162 2163 In the current implementation, the local variables 2164 space and global environment variables space are 2165 separated. Local variables are those you define by 2166 simply typing `name=value'. To access a local 2167 variable later on, you have write `$name' or 2168 `${name}'; to execute the contents of a variable 2169 directly type `$name' at the command prompt. 2170 2171 Global environment variables are those you use 2172 setenv/printenv to work with. To run a command stored 2173 in such a variable, you need to use the run command, 2174 and you must not use the '$' sign to access them. 2175 2176 To store commands and special characters in a 2177 variable, please use double quotation marks 2178 surrounding the whole text of the variable, instead 2179 of the backslashes before semicolons and special 2180 symbols. 2181 2182- Command Line Editing and History: 2183 CONFIG_CMDLINE_PS_SUPPORT 2184 2185 Enable support for changing the command prompt string 2186 at run-time. Only static string is supported so far. 2187 The string is obtained from environment variables PS1 2188 and PS2. 2189 2190- Default Environment: 2191 CONFIG_EXTRA_ENV_SETTINGS 2192 2193 Define this to contain any number of null terminated 2194 strings (variable = value pairs) that will be part of 2195 the default environment compiled into the boot image. 2196 2197 For example, place something like this in your 2198 board's config file: 2199 2200 #define CONFIG_EXTRA_ENV_SETTINGS \ 2201 "myvar1=value1\0" \ 2202 "myvar2=value2\0" 2203 2204 Warning: This method is based on knowledge about the 2205 internal format how the environment is stored by the 2206 U-Boot code. This is NOT an official, exported 2207 interface! Although it is unlikely that this format 2208 will change soon, there is no guarantee either. 2209 You better know what you are doing here. 2210 2211 Note: overly (ab)use of the default environment is 2212 discouraged. Make sure to check other ways to preset 2213 the environment like the "source" command or the 2214 boot command first. 2215 2216 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG 2217 2218 Define this in order to add variables describing certain 2219 run-time determined information about the hardware to the 2220 environment. These will be named board_name, board_rev. 2221 2222 CONFIG_DELAY_ENVIRONMENT 2223 2224 Normally the environment is loaded when the board is 2225 initialised so that it is available to U-Boot. This inhibits 2226 that so that the environment is not available until 2227 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL 2228 this is instead controlled by the value of 2229 /config/load-environment. 2230 2231- Serial Flash support 2232 Usage requires an initial 'sf probe' to define the serial 2233 flash parameters, followed by read/write/erase/update 2234 commands. 2235 2236 The following defaults may be provided by the platform 2237 to handle the common case when only a single serial 2238 flash is present on the system. 2239 2240 CONFIG_SF_DEFAULT_BUS Bus identifier 2241 CONFIG_SF_DEFAULT_CS Chip-select 2242 CONFIG_SF_DEFAULT_MODE (see include/spi.h) 2243 CONFIG_SF_DEFAULT_SPEED in Hz 2244 2245 2246- TFTP Fixed UDP Port: 2247 CONFIG_TFTP_PORT 2248 2249 If this is defined, the environment variable tftpsrcp 2250 is used to supply the TFTP UDP source port value. 2251 If tftpsrcp isn't defined, the normal pseudo-random port 2252 number generator is used. 2253 2254 Also, the environment variable tftpdstp is used to supply 2255 the TFTP UDP destination port value. If tftpdstp isn't 2256 defined, the normal port 69 is used. 2257 2258 The purpose for tftpsrcp is to allow a TFTP server to 2259 blindly start the TFTP transfer using the pre-configured 2260 target IP address and UDP port. This has the effect of 2261 "punching through" the (Windows XP) firewall, allowing 2262 the remainder of the TFTP transfer to proceed normally. 2263 A better solution is to properly configure the firewall, 2264 but sometimes that is not allowed. 2265 2266- Show boot progress: 2267 CONFIG_SHOW_BOOT_PROGRESS 2268 2269 Defining this option allows to add some board- 2270 specific code (calling a user-provided function 2271 "show_boot_progress(int)") that enables you to show 2272 the system's boot progress on some display (for 2273 example, some LED's) on your board. At the moment, 2274 the following checkpoints are implemented: 2275 2276 2277Legacy uImage format: 2278 2279 Arg Where When 2280 1 common/cmd_bootm.c before attempting to boot an image 2281 -1 common/cmd_bootm.c Image header has bad magic number 2282 2 common/cmd_bootm.c Image header has correct magic number 2283 -2 common/cmd_bootm.c Image header has bad checksum 2284 3 common/cmd_bootm.c Image header has correct checksum 2285 -3 common/cmd_bootm.c Image data has bad checksum 2286 4 common/cmd_bootm.c Image data has correct checksum 2287 -4 common/cmd_bootm.c Image is for unsupported architecture 2288 5 common/cmd_bootm.c Architecture check OK 2289 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi) 2290 6 common/cmd_bootm.c Image Type check OK 2291 -6 common/cmd_bootm.c gunzip uncompression error 2292 -7 common/cmd_bootm.c Unimplemented compression type 2293 7 common/cmd_bootm.c Uncompression OK 2294 8 common/cmd_bootm.c No uncompress/copy overwrite error 2295 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX) 2296 2297 9 common/image.c Start initial ramdisk verification 2298 -10 common/image.c Ramdisk header has bad magic number 2299 -11 common/image.c Ramdisk header has bad checksum 2300 10 common/image.c Ramdisk header is OK 2301 -12 common/image.c Ramdisk data has bad checksum 2302 11 common/image.c Ramdisk data has correct checksum 2303 12 common/image.c Ramdisk verification complete, start loading 2304 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk) 2305 13 common/image.c Start multifile image verification 2306 14 common/image.c No initial ramdisk, no multifile, continue. 2307 2308 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS 2309 2310 -30 arch/powerpc/lib/board.c Fatal error, hang the system 2311 -31 post/post.c POST test failed, detected by post_output_backlog() 2312 -32 post/post.c POST test failed, detected by post_run_single() 2313 2314 34 common/cmd_doc.c before loading a Image from a DOC device 2315 -35 common/cmd_doc.c Bad usage of "doc" command 2316 35 common/cmd_doc.c correct usage of "doc" command 2317 -36 common/cmd_doc.c No boot device 2318 36 common/cmd_doc.c correct boot device 2319 -37 common/cmd_doc.c Unknown Chip ID on boot device 2320 37 common/cmd_doc.c correct chip ID found, device available 2321 -38 common/cmd_doc.c Read Error on boot device 2322 38 common/cmd_doc.c reading Image header from DOC device OK 2323 -39 common/cmd_doc.c Image header has bad magic number 2324 39 common/cmd_doc.c Image header has correct magic number 2325 -40 common/cmd_doc.c Error reading Image from DOC device 2326 40 common/cmd_doc.c Image header has correct magic number 2327 41 common/cmd_ide.c before loading a Image from a IDE device 2328 -42 common/cmd_ide.c Bad usage of "ide" command 2329 42 common/cmd_ide.c correct usage of "ide" command 2330 -43 common/cmd_ide.c No boot device 2331 43 common/cmd_ide.c boot device found 2332 -44 common/cmd_ide.c Device not available 2333 44 common/cmd_ide.c Device available 2334 -45 common/cmd_ide.c wrong partition selected 2335 45 common/cmd_ide.c partition selected 2336 -46 common/cmd_ide.c Unknown partition table 2337 46 common/cmd_ide.c valid partition table found 2338 -47 common/cmd_ide.c Invalid partition type 2339 47 common/cmd_ide.c correct partition type 2340 -48 common/cmd_ide.c Error reading Image Header on boot device 2341 48 common/cmd_ide.c reading Image Header from IDE device OK 2342 -49 common/cmd_ide.c Image header has bad magic number 2343 49 common/cmd_ide.c Image header has correct magic number 2344 -50 common/cmd_ide.c Image header has bad checksum 2345 50 common/cmd_ide.c Image header has correct checksum 2346 -51 common/cmd_ide.c Error reading Image from IDE device 2347 51 common/cmd_ide.c reading Image from IDE device OK 2348 52 common/cmd_nand.c before loading a Image from a NAND device 2349 -53 common/cmd_nand.c Bad usage of "nand" command 2350 53 common/cmd_nand.c correct usage of "nand" command 2351 -54 common/cmd_nand.c No boot device 2352 54 common/cmd_nand.c boot device found 2353 -55 common/cmd_nand.c Unknown Chip ID on boot device 2354 55 common/cmd_nand.c correct chip ID found, device available 2355 -56 common/cmd_nand.c Error reading Image Header on boot device 2356 56 common/cmd_nand.c reading Image Header from NAND device OK 2357 -57 common/cmd_nand.c Image header has bad magic number 2358 57 common/cmd_nand.c Image header has correct magic number 2359 -58 common/cmd_nand.c Error reading Image from NAND device 2360 58 common/cmd_nand.c reading Image from NAND device OK 2361 2362 -60 common/env_common.c Environment has a bad CRC, using default 2363 2364 64 net/eth.c starting with Ethernet configuration. 2365 -64 net/eth.c no Ethernet found. 2366 65 net/eth.c Ethernet found. 2367 2368 -80 common/cmd_net.c usage wrong 2369 80 common/cmd_net.c before calling net_loop() 2370 -81 common/cmd_net.c some error in net_loop() occurred 2371 81 common/cmd_net.c net_loop() back without error 2372 -82 common/cmd_net.c size == 0 (File with size 0 loaded) 2373 82 common/cmd_net.c trying automatic boot 2374 83 common/cmd_net.c running "source" command 2375 -83 common/cmd_net.c some error in automatic boot or "source" command 2376 84 common/cmd_net.c end without errors 2377 2378FIT uImage format: 2379 2380 Arg Where When 2381 100 common/cmd_bootm.c Kernel FIT Image has correct format 2382 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format 2383 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration 2384 -101 common/cmd_bootm.c Can't get configuration for kernel subimage 2385 102 common/cmd_bootm.c Kernel unit name specified 2386 -103 common/cmd_bootm.c Can't get kernel subimage node offset 2387 103 common/cmd_bootm.c Found configuration node 2388 104 common/cmd_bootm.c Got kernel subimage node offset 2389 -104 common/cmd_bootm.c Kernel subimage hash verification failed 2390 105 common/cmd_bootm.c Kernel subimage hash verification OK 2391 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture 2392 106 common/cmd_bootm.c Architecture check OK 2393 -106 common/cmd_bootm.c Kernel subimage has wrong type 2394 107 common/cmd_bootm.c Kernel subimage type OK 2395 -107 common/cmd_bootm.c Can't get kernel subimage data/size 2396 108 common/cmd_bootm.c Got kernel subimage data/size 2397 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT) 2398 -109 common/cmd_bootm.c Can't get kernel subimage type 2399 -110 common/cmd_bootm.c Can't get kernel subimage comp 2400 -111 common/cmd_bootm.c Can't get kernel subimage os 2401 -112 common/cmd_bootm.c Can't get kernel subimage load address 2402 -113 common/cmd_bootm.c Image uncompress/copy overwrite error 2403 2404 120 common/image.c Start initial ramdisk verification 2405 -120 common/image.c Ramdisk FIT image has incorrect format 2406 121 common/image.c Ramdisk FIT image has correct format 2407 122 common/image.c No ramdisk subimage unit name, using configuration 2408 -122 common/image.c Can't get configuration for ramdisk subimage 2409 123 common/image.c Ramdisk unit name specified 2410 -124 common/image.c Can't get ramdisk subimage node offset 2411 125 common/image.c Got ramdisk subimage node offset 2412 -125 common/image.c Ramdisk subimage hash verification failed 2413 126 common/image.c Ramdisk subimage hash verification OK 2414 -126 common/image.c Ramdisk subimage for unsupported architecture 2415 127 common/image.c Architecture check OK 2416 -127 common/image.c Can't get ramdisk subimage data/size 2417 128 common/image.c Got ramdisk subimage data/size 2418 129 common/image.c Can't get ramdisk load address 2419 -129 common/image.c Got ramdisk load address 2420 2421 -130 common/cmd_doc.c Incorrect FIT image format 2422 131 common/cmd_doc.c FIT image format OK 2423 2424 -140 common/cmd_ide.c Incorrect FIT image format 2425 141 common/cmd_ide.c FIT image format OK 2426 2427 -150 common/cmd_nand.c Incorrect FIT image format 2428 151 common/cmd_nand.c FIT image format OK 2429 2430- legacy image format: 2431 CONFIG_IMAGE_FORMAT_LEGACY 2432 enables the legacy image format support in U-Boot. 2433 2434 Default: 2435 enabled if CONFIG_FIT_SIGNATURE is not defined. 2436 2437 CONFIG_DISABLE_IMAGE_LEGACY 2438 disable the legacy image format 2439 2440 This define is introduced, as the legacy image format is 2441 enabled per default for backward compatibility. 2442 2443- Standalone program support: 2444 CONFIG_STANDALONE_LOAD_ADDR 2445 2446 This option defines a board specific value for the 2447 address where standalone program gets loaded, thus 2448 overwriting the architecture dependent default 2449 settings. 2450 2451- Frame Buffer Address: 2452 CONFIG_FB_ADDR 2453 2454 Define CONFIG_FB_ADDR if you want to use specific 2455 address for frame buffer. This is typically the case 2456 when using a graphics controller has separate video 2457 memory. U-Boot will then place the frame buffer at 2458 the given address instead of dynamically reserving it 2459 in system RAM by calling lcd_setmem(), which grabs 2460 the memory for the frame buffer depending on the 2461 configured panel size. 2462 2463 Please see board_init_f function. 2464 2465- Automatic software updates via TFTP server 2466 CONFIG_UPDATE_TFTP 2467 CONFIG_UPDATE_TFTP_CNT_MAX 2468 CONFIG_UPDATE_TFTP_MSEC_MAX 2469 2470 These options enable and control the auto-update feature; 2471 for a more detailed description refer to doc/README.update. 2472 2473- MTD Support (mtdparts command, UBI support) 2474 CONFIG_MTD_DEVICE 2475 2476 Adds the MTD device infrastructure from the Linux kernel. 2477 Needed for mtdparts command support. 2478 2479 CONFIG_MTD_PARTITIONS 2480 2481 Adds the MTD partitioning infrastructure from the Linux 2482 kernel. Needed for UBI support. 2483 2484- UBI support 2485 CONFIG_MTD_UBI_WL_THRESHOLD 2486 This parameter defines the maximum difference between the highest 2487 erase counter value and the lowest erase counter value of eraseblocks 2488 of UBI devices. When this threshold is exceeded, UBI starts performing 2489 wear leveling by means of moving data from eraseblock with low erase 2490 counter to eraseblocks with high erase counter. 2491 2492 The default value should be OK for SLC NAND flashes, NOR flashes and 2493 other flashes which have eraseblock life-cycle 100000 or more. 2494 However, in case of MLC NAND flashes which typically have eraseblock 2495 life-cycle less than 10000, the threshold should be lessened (e.g., 2496 to 128 or 256, although it does not have to be power of 2). 2497 2498 default: 4096 2499 2500 CONFIG_MTD_UBI_BEB_LIMIT 2501 This option specifies the maximum bad physical eraseblocks UBI 2502 expects on the MTD device (per 1024 eraseblocks). If the 2503 underlying flash does not admit of bad eraseblocks (e.g. NOR 2504 flash), this value is ignored. 2505 2506 NAND datasheets often specify the minimum and maximum NVM 2507 (Number of Valid Blocks) for the flashes' endurance lifetime. 2508 The maximum expected bad eraseblocks per 1024 eraseblocks 2509 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)", 2510 which gives 20 for most NANDs (MaxNVB is basically the total 2511 count of eraseblocks on the chip). 2512 2513 To put it differently, if this value is 20, UBI will try to 2514 reserve about 1.9% of physical eraseblocks for bad blocks 2515 handling. And that will be 1.9% of eraseblocks on the entire 2516 NAND chip, not just the MTD partition UBI attaches. This means 2517 that if you have, say, a NAND flash chip admits maximum 40 bad 2518 eraseblocks, and it is split on two MTD partitions of the same 2519 size, UBI will reserve 40 eraseblocks when attaching a 2520 partition. 2521 2522 default: 20 2523 2524 CONFIG_MTD_UBI_FASTMAP 2525 Fastmap is a mechanism which allows attaching an UBI device 2526 in nearly constant time. Instead of scanning the whole MTD device it 2527 only has to locate a checkpoint (called fastmap) on the device. 2528 The on-flash fastmap contains all information needed to attach 2529 the device. Using fastmap makes only sense on large devices where 2530 attaching by scanning takes long. UBI will not automatically install 2531 a fastmap on old images, but you can set the UBI parameter 2532 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note 2533 that fastmap-enabled images are still usable with UBI implementations 2534 without fastmap support. On typical flash devices the whole fastmap 2535 fits into one PEB. UBI will reserve PEBs to hold two fastmaps. 2536 2537 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 2538 Set this parameter to enable fastmap automatically on images 2539 without a fastmap. 2540 default: 0 2541 2542 CONFIG_MTD_UBI_FM_DEBUG 2543 Enable UBI fastmap debug 2544 default: 0 2545 2546- SPL framework 2547 CONFIG_SPL 2548 Enable building of SPL globally. 2549 2550 CONFIG_SPL_LDSCRIPT 2551 LDSCRIPT for linking the SPL binary. 2552 2553 CONFIG_SPL_MAX_FOOTPRINT 2554 Maximum size in memory allocated to the SPL, BSS included. 2555 When defined, the linker checks that the actual memory 2556 used by SPL from _start to __bss_end does not exceed it. 2557 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2558 must not be both defined at the same time. 2559 2560 CONFIG_SPL_MAX_SIZE 2561 Maximum size of the SPL image (text, data, rodata, and 2562 linker lists sections), BSS excluded. 2563 When defined, the linker checks that the actual size does 2564 not exceed it. 2565 2566 CONFIG_SPL_TEXT_BASE 2567 TEXT_BASE for linking the SPL binary. 2568 2569 CONFIG_SPL_RELOC_TEXT_BASE 2570 Address to relocate to. If unspecified, this is equal to 2571 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done). 2572 2573 CONFIG_SPL_BSS_START_ADDR 2574 Link address for the BSS within the SPL binary. 2575 2576 CONFIG_SPL_BSS_MAX_SIZE 2577 Maximum size in memory allocated to the SPL BSS. 2578 When defined, the linker checks that the actual memory used 2579 by SPL from __bss_start to __bss_end does not exceed it. 2580 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE 2581 must not be both defined at the same time. 2582 2583 CONFIG_SPL_STACK 2584 Adress of the start of the stack SPL will use 2585 2586 CONFIG_SPL_PANIC_ON_RAW_IMAGE 2587 When defined, SPL will panic() if the image it has 2588 loaded does not have a signature. 2589 Defining this is useful when code which loads images 2590 in SPL cannot guarantee that absolutely all read errors 2591 will be caught. 2592 An example is the LPC32XX MLC NAND driver, which will 2593 consider that a completely unreadable NAND block is bad, 2594 and thus should be skipped silently. 2595 2596 CONFIG_SPL_RELOC_STACK 2597 Adress of the start of the stack SPL will use after 2598 relocation. If unspecified, this is equal to 2599 CONFIG_SPL_STACK. 2600 2601 CONFIG_SYS_SPL_MALLOC_START 2602 Starting address of the malloc pool used in SPL. 2603 When this option is set the full malloc is used in SPL and 2604 it is set up by spl_init() and before that, the simple malloc() 2605 can be used if CONFIG_SYS_MALLOC_F is defined. 2606 2607 CONFIG_SYS_SPL_MALLOC_SIZE 2608 The size of the malloc pool used in SPL. 2609 2610 CONFIG_SPL_OS_BOOT 2611 Enable booting directly to an OS from SPL. 2612 See also: doc/README.falcon 2613 2614 CONFIG_SPL_DISPLAY_PRINT 2615 For ARM, enable an optional function to print more information 2616 about the running system. 2617 2618 CONFIG_SPL_INIT_MINIMAL 2619 Arch init code should be built for a very small image 2620 2621 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION 2622 Partition on the MMC to load U-Boot from when the MMC is being 2623 used in raw mode 2624 2625 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR 2626 Sector to load kernel uImage from when MMC is being 2627 used in raw mode (for Falcon mode) 2628 2629 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR, 2630 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS 2631 Sector and number of sectors to load kernel argument 2632 parameters from when MMC is being used in raw mode 2633 (for falcon mode) 2634 2635 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION 2636 Partition on the MMC to load U-Boot from when the MMC is being 2637 used in fs mode 2638 2639 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME 2640 Filename to read to load U-Boot when reading from filesystem 2641 2642 CONFIG_SPL_FS_LOAD_KERNEL_NAME 2643 Filename to read to load kernel uImage when reading 2644 from filesystem (for Falcon mode) 2645 2646 CONFIG_SPL_FS_LOAD_ARGS_NAME 2647 Filename to read to load kernel argument parameters 2648 when reading from filesystem (for Falcon mode) 2649 2650 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND 2651 Set this for NAND SPL on PPC mpc83xx targets, so that 2652 start.S waits for the rest of the SPL to load before 2653 continuing (the hardware starts execution after just 2654 loading the first page rather than the full 4K). 2655 2656 CONFIG_SPL_SKIP_RELOCATE 2657 Avoid SPL relocation 2658 2659 CONFIG_SPL_NAND_BASE 2660 Include nand_base.c in the SPL. Requires 2661 CONFIG_SPL_NAND_DRIVERS. 2662 2663 CONFIG_SPL_NAND_DRIVERS 2664 SPL uses normal NAND drivers, not minimal drivers. 2665 2666 CONFIG_SPL_NAND_ECC 2667 Include standard software ECC in the SPL 2668 2669 CONFIG_SPL_NAND_SIMPLE 2670 Support for NAND boot using simple NAND drivers that 2671 expose the cmd_ctrl() interface. 2672 2673 CONFIG_SPL_UBI 2674 Support for a lightweight UBI (fastmap) scanner and 2675 loader 2676 2677 CONFIG_SPL_NAND_RAW_ONLY 2678 Support to boot only raw u-boot.bin images. Use this only 2679 if you need to save space. 2680 2681 CONFIG_SPL_COMMON_INIT_DDR 2682 Set for common ddr init with serial presence detect in 2683 SPL binary. 2684 2685 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT, 2686 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE, 2687 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS, 2688 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE, 2689 CONFIG_SYS_NAND_ECCBYTES 2690 Defines the size and behavior of the NAND that SPL uses 2691 to read U-Boot 2692 2693 CONFIG_SPL_NAND_BOOT 2694 Add support NAND boot 2695 2696 CONFIG_SYS_NAND_U_BOOT_OFFS 2697 Location in NAND to read U-Boot from 2698 2699 CONFIG_SYS_NAND_U_BOOT_DST 2700 Location in memory to load U-Boot to 2701 2702 CONFIG_SYS_NAND_U_BOOT_SIZE 2703 Size of image to load 2704 2705 CONFIG_SYS_NAND_U_BOOT_START 2706 Entry point in loaded image to jump to 2707 2708 CONFIG_SYS_NAND_HW_ECC_OOBFIRST 2709 Define this if you need to first read the OOB and then the 2710 data. This is used, for example, on davinci platforms. 2711 2712 CONFIG_SPL_RAM_DEVICE 2713 Support for running image already present in ram, in SPL binary 2714 2715 CONFIG_SPL_PAD_TO 2716 Image offset to which the SPL should be padded before appending 2717 the SPL payload. By default, this is defined as 2718 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2719 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2720 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2721 2722 CONFIG_SPL_TARGET 2723 Final target image containing SPL and payload. Some SPLs 2724 use an arch-specific makefile fragment instead, for 2725 example if more than one image needs to be produced. 2726 2727 CONFIG_FIT_SPL_PRINT 2728 Printing information about a FIT image adds quite a bit of 2729 code to SPL. So this is normally disabled in SPL. Use this 2730 option to re-enable it. This will affect the output of the 2731 bootm command when booting a FIT image. 2732 2733- TPL framework 2734 CONFIG_TPL 2735 Enable building of TPL globally. 2736 2737 CONFIG_TPL_PAD_TO 2738 Image offset to which the TPL should be padded before appending 2739 the TPL payload. By default, this is defined as 2740 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined. 2741 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL 2742 payload without any padding, or >= CONFIG_SPL_MAX_SIZE. 2743 2744- Interrupt support (PPC): 2745 2746 There are common interrupt_init() and timer_interrupt() 2747 for all PPC archs. interrupt_init() calls interrupt_init_cpu() 2748 for CPU specific initialization. interrupt_init_cpu() 2749 should set decrementer_count to appropriate value. If 2750 CPU resets decrementer automatically after interrupt 2751 (ppc4xx) it should set decrementer_count to zero. 2752 timer_interrupt() calls timer_interrupt_cpu() for CPU 2753 specific handling. If board has watchdog / status_led 2754 / other_activity_monitor it works automatically from 2755 general timer_interrupt(). 2756 2757 2758Board initialization settings: 2759------------------------------ 2760 2761During Initialization u-boot calls a number of board specific functions 2762to allow the preparation of board specific prerequisites, e.g. pin setup 2763before drivers are initialized. To enable these callbacks the 2764following configuration macros have to be defined. Currently this is 2765architecture specific, so please check arch/your_architecture/lib/board.c 2766typically in board_init_f() and board_init_r(). 2767 2768- CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f() 2769- CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r() 2770- CONFIG_BOARD_LATE_INIT: Call board_late_init() 2771- CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init() 2772 2773Configuration Settings: 2774----------------------- 2775 2776- CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit. 2777 Optionally it can be defined to support 64-bit memory commands. 2778 2779- CONFIG_SYS_LONGHELP: Defined when you want long help messages included; 2780 undefine this when you're short of memory. 2781 2782- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default 2783 width of the commands listed in the 'help' command output. 2784 2785- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to 2786 prompt for user input. 2787 2788- CONFIG_SYS_CBSIZE: Buffer size for input from the Console 2789 2790- CONFIG_SYS_PBSIZE: Buffer size for Console output 2791 2792- CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands 2793 2794- CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to 2795 the application (usually a Linux kernel) when it is 2796 booted 2797 2798- CONFIG_SYS_BAUDRATE_TABLE: 2799 List of legal baudrate settings for this board. 2800 2801- CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END: 2802 Begin and End addresses of the area used by the 2803 simple memory test. 2804 2805- CONFIG_SYS_MEMTEST_SCRATCH: 2806 Scratch address used by the alternate memory test 2807 You only need to set this if address zero isn't writeable 2808 2809- CONFIG_SYS_MEM_RESERVE_SECURE 2810 Only implemented for ARMv8 for now. 2811 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory 2812 is substracted from total RAM and won't be reported to OS. 2813 This memory can be used as secure memory. A variable 2814 gd->arch.secure_ram is used to track the location. In systems 2815 the RAM base is not zero, or RAM is divided into banks, 2816 this variable needs to be recalcuated to get the address. 2817 2818- CONFIG_SYS_MEM_TOP_HIDE: 2819 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, 2820 this specified memory area will get subtracted from the top 2821 (end) of RAM and won't get "touched" at all by U-Boot. By 2822 fixing up gd->ram_size the Linux kernel should gets passed 2823 the now "corrected" memory size and won't touch it either. 2824 This should work for arch/ppc and arch/powerpc. Only Linux 2825 board ports in arch/powerpc with bootwrapper support that 2826 recalculate the memory size from the SDRAM controller setup 2827 will have to get fixed in Linux additionally. 2828 2829 This option can be used as a workaround for the 440EPx/GRx 2830 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't 2831 be touched. 2832 2833 WARNING: Please make sure that this value is a multiple of 2834 the Linux page size (normally 4k). If this is not the case, 2835 then the end address of the Linux memory will be located at a 2836 non page size aligned address and this could cause major 2837 problems. 2838 2839- CONFIG_SYS_LOADS_BAUD_CHANGE: 2840 Enable temporary baudrate change while serial download 2841 2842- CONFIG_SYS_SDRAM_BASE: 2843 Physical start address of SDRAM. _Must_ be 0 here. 2844 2845- CONFIG_SYS_FLASH_BASE: 2846 Physical start address of Flash memory. 2847 2848- CONFIG_SYS_MONITOR_BASE: 2849 Physical start address of boot monitor code (set by 2850 make config files to be same as the text base address 2851 (CONFIG_SYS_TEXT_BASE) used when linking) - same as 2852 CONFIG_SYS_FLASH_BASE when booting from flash. 2853 2854- CONFIG_SYS_MONITOR_LEN: 2855 Size of memory reserved for monitor code, used to 2856 determine _at_compile_time_ (!) if the environment is 2857 embedded within the U-Boot image, or in a separate 2858 flash sector. 2859 2860- CONFIG_SYS_MALLOC_LEN: 2861 Size of DRAM reserved for malloc() use. 2862 2863- CONFIG_SYS_MALLOC_F_LEN 2864 Size of the malloc() pool for use before relocation. If 2865 this is defined, then a very simple malloc() implementation 2866 will become available before relocation. The address is just 2867 below the global data, and the stack is moved down to make 2868 space. 2869 2870 This feature allocates regions with increasing addresses 2871 within the region. calloc() is supported, but realloc() 2872 is not available. free() is supported but does nothing. 2873 The memory will be freed (or in fact just forgotten) when 2874 U-Boot relocates itself. 2875 2876- CONFIG_SYS_MALLOC_SIMPLE 2877 Provides a simple and small malloc() and calloc() for those 2878 boards which do not use the full malloc in SPL (which is 2879 enabled with CONFIG_SYS_SPL_MALLOC_START). 2880 2881- CONFIG_SYS_NONCACHED_MEMORY: 2882 Size of non-cached memory area. This area of memory will be 2883 typically located right below the malloc() area and mapped 2884 uncached in the MMU. This is useful for drivers that would 2885 otherwise require a lot of explicit cache maintenance. For 2886 some drivers it's also impossible to properly maintain the 2887 cache. For example if the regions that need to be flushed 2888 are not a multiple of the cache-line size, *and* padding 2889 cannot be allocated between the regions to align them (i.e. 2890 if the HW requires a contiguous array of regions, and the 2891 size of each region is not cache-aligned), then a flush of 2892 one region may result in overwriting data that hardware has 2893 written to another region in the same cache-line. This can 2894 happen for example in network drivers where descriptors for 2895 buffers are typically smaller than the CPU cache-line (e.g. 2896 16 bytes vs. 32 or 64 bytes). 2897 2898 Non-cached memory is only supported on 32-bit ARM at present. 2899 2900- CONFIG_SYS_BOOTM_LEN: 2901 Normally compressed uImages are limited to an 2902 uncompressed size of 8 MBytes. If this is not enough, 2903 you can define CONFIG_SYS_BOOTM_LEN in your board config file 2904 to adjust this setting to your needs. 2905 2906- CONFIG_SYS_BOOTMAPSZ: 2907 Maximum size of memory mapped by the startup code of 2908 the Linux kernel; all data that must be processed by 2909 the Linux kernel (bd_info, boot arguments, FDT blob if 2910 used) must be put below this limit, unless "bootm_low" 2911 environment variable is defined and non-zero. In such case 2912 all data for the Linux kernel must be between "bootm_low" 2913 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment 2914 variable "bootm_mapsize" will override the value of 2915 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined, 2916 then the value in "bootm_size" will be used instead. 2917 2918- CONFIG_SYS_BOOT_RAMDISK_HIGH: 2919 Enable initrd_high functionality. If defined then the 2920 initrd_high feature is enabled and the bootm ramdisk subcommand 2921 is enabled. 2922 2923- CONFIG_SYS_BOOT_GET_CMDLINE: 2924 Enables allocating and saving kernel cmdline in space between 2925 "bootm_low" and "bootm_low" + BOOTMAPSZ. 2926 2927- CONFIG_SYS_BOOT_GET_KBD: 2928 Enables allocating and saving a kernel copy of the bd_info in 2929 space between "bootm_low" and "bootm_low" + BOOTMAPSZ. 2930 2931- CONFIG_SYS_MAX_FLASH_BANKS: 2932 Max number of Flash memory banks 2933 2934- CONFIG_SYS_MAX_FLASH_SECT: 2935 Max number of sectors on a Flash chip 2936 2937- CONFIG_SYS_FLASH_ERASE_TOUT: 2938 Timeout for Flash erase operations (in ms) 2939 2940- CONFIG_SYS_FLASH_WRITE_TOUT: 2941 Timeout for Flash write operations (in ms) 2942 2943- CONFIG_SYS_FLASH_LOCK_TOUT 2944 Timeout for Flash set sector lock bit operation (in ms) 2945 2946- CONFIG_SYS_FLASH_UNLOCK_TOUT 2947 Timeout for Flash clear lock bits operation (in ms) 2948 2949- CONFIG_SYS_FLASH_PROTECTION 2950 If defined, hardware flash sectors protection is used 2951 instead of U-Boot software protection. 2952 2953- CONFIG_SYS_DIRECT_FLASH_TFTP: 2954 2955 Enable TFTP transfers directly to flash memory; 2956 without this option such a download has to be 2957 performed in two steps: (1) download to RAM, and (2) 2958 copy from RAM to flash. 2959 2960 The two-step approach is usually more reliable, since 2961 you can check if the download worked before you erase 2962 the flash, but in some situations (when system RAM is 2963 too limited to allow for a temporary copy of the 2964 downloaded image) this option may be very useful. 2965 2966- CONFIG_SYS_FLASH_CFI: 2967 Define if the flash driver uses extra elements in the 2968 common flash structure for storing flash geometry. 2969 2970- CONFIG_FLASH_CFI_DRIVER 2971 This option also enables the building of the cfi_flash driver 2972 in the drivers directory 2973 2974- CONFIG_FLASH_CFI_MTD 2975 This option enables the building of the cfi_mtd driver 2976 in the drivers directory. The driver exports CFI flash 2977 to the MTD layer. 2978 2979- CONFIG_SYS_FLASH_USE_BUFFER_WRITE 2980 Use buffered writes to flash. 2981 2982- CONFIG_FLASH_SPANSION_S29WS_N 2983 s29ws-n MirrorBit flash has non-standard addresses for buffered 2984 write commands. 2985 2986- CONFIG_SYS_FLASH_QUIET_TEST 2987 If this option is defined, the common CFI flash doesn't 2988 print it's warning upon not recognized FLASH banks. This 2989 is useful, if some of the configured banks are only 2990 optionally available. 2991 2992- CONFIG_FLASH_SHOW_PROGRESS 2993 If defined (must be an integer), print out countdown 2994 digits and dots. Recommended value: 45 (9..1) for 80 2995 column displays, 15 (3..1) for 40 column displays. 2996 2997- CONFIG_FLASH_VERIFY 2998 If defined, the content of the flash (destination) is compared 2999 against the source after the write operation. An error message 3000 will be printed when the contents are not identical. 3001 Please note that this option is useless in nearly all cases, 3002 since such flash programming errors usually are detected earlier 3003 while unprotecting/erasing/programming. Please only enable 3004 this option if you really know what you are doing. 3005 3006- CONFIG_SYS_RX_ETH_BUFFER: 3007 Defines the number of Ethernet receive buffers. On some 3008 Ethernet controllers it is recommended to set this value 3009 to 8 or even higher (EEPRO100 or 405 EMAC), since all 3010 buffers can be full shortly after enabling the interface 3011 on high Ethernet traffic. 3012 Defaults to 4 if not defined. 3013 3014- CONFIG_ENV_MAX_ENTRIES 3015 3016 Maximum number of entries in the hash table that is used 3017 internally to store the environment settings. The default 3018 setting is supposed to be generous and should work in most 3019 cases. This setting can be used to tune behaviour; see 3020 lib/hashtable.c for details. 3021 3022- CONFIG_ENV_FLAGS_LIST_DEFAULT 3023- CONFIG_ENV_FLAGS_LIST_STATIC 3024 Enable validation of the values given to environment variables when 3025 calling env set. Variables can be restricted to only decimal, 3026 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined, 3027 the variables can also be restricted to IP address or MAC address. 3028 3029 The format of the list is: 3030 type_attribute = [s|d|x|b|i|m] 3031 access_attribute = [a|r|o|c] 3032 attributes = type_attribute[access_attribute] 3033 entry = variable_name[:attributes] 3034 list = entry[,list] 3035 3036 The type attributes are: 3037 s - String (default) 3038 d - Decimal 3039 x - Hexadecimal 3040 b - Boolean ([1yYtT|0nNfF]) 3041 i - IP address 3042 m - MAC address 3043 3044 The access attributes are: 3045 a - Any (default) 3046 r - Read-only 3047 o - Write-once 3048 c - Change-default 3049 3050 - CONFIG_ENV_FLAGS_LIST_DEFAULT 3051 Define this to a list (string) to define the ".flags" 3052 environment variable in the default or embedded environment. 3053 3054 - CONFIG_ENV_FLAGS_LIST_STATIC 3055 Define this to a list (string) to define validation that 3056 should be done if an entry is not found in the ".flags" 3057 environment variable. To override a setting in the static 3058 list, simply add an entry for the same variable name to the 3059 ".flags" variable. 3060 3061 If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3062 regular expression. This allows multiple variables to define the same 3063 flags without explicitly listing them for each variable. 3064 3065- CONFIG_ENV_ACCESS_IGNORE_FORCE 3066 If defined, don't allow the -f switch to env set override variable 3067 access flags. 3068 3069- CONFIG_USE_STDINT 3070 If stdint.h is available with your toolchain you can define this 3071 option to enable it. You can provide option 'USE_STDINT=1' when 3072 building U-Boot to enable this. 3073 3074The following definitions that deal with the placement and management 3075of environment data (variable area); in general, we support the 3076following configurations: 3077 3078- CONFIG_BUILD_ENVCRC: 3079 3080 Builds up envcrc with the target environment so that external utils 3081 may easily extract it and embed it in final U-Boot images. 3082 3083BE CAREFUL! The first access to the environment happens quite early 3084in U-Boot initialization (when we try to get the setting of for the 3085console baudrate). You *MUST* have mapped your NVRAM area then, or 3086U-Boot will hang. 3087 3088Please note that even with NVRAM we still use a copy of the 3089environment in RAM: we could work on NVRAM directly, but we want to 3090keep settings there always unmodified except somebody uses "saveenv" 3091to save the current settings. 3092 3093BE CAREFUL! For some special cases, the local device can not use 3094"saveenv" command. For example, the local device will get the 3095environment stored in a remote NOR flash by SRIO or PCIE link, 3096but it can not erase, write this NOR flash by SRIO or PCIE interface. 3097 3098- CONFIG_NAND_ENV_DST 3099 3100 Defines address in RAM to which the nand_spl code should copy the 3101 environment. If redundant environment is used, it will be copied to 3102 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE. 3103 3104Please note that the environment is read-only until the monitor 3105has been relocated to RAM and a RAM copy of the environment has been 3106created; also, when using EEPROM you will have to use env_get_f() 3107until then to read environment variables. 3108 3109The environment is protected by a CRC32 checksum. Before the monitor 3110is relocated into RAM, as a result of a bad CRC you will be working 3111with the compiled-in default environment - *silently*!!! [This is 3112necessary, because the first environment variable we need is the 3113"baudrate" setting for the console - if we have a bad CRC, we don't 3114have any device yet where we could complain.] 3115 3116Note: once the monitor has been relocated, then it will complain if 3117the default environment is used; a new CRC is computed as soon as you 3118use the "saveenv" command to store a valid environment. 3119 3120- CONFIG_SYS_FAULT_ECHO_LINK_DOWN: 3121 Echo the inverted Ethernet link state to the fault LED. 3122 3123 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR 3124 also needs to be defined. 3125 3126- CONFIG_SYS_FAULT_MII_ADDR: 3127 MII address of the PHY to check for the Ethernet link state. 3128 3129- CONFIG_NS16550_MIN_FUNCTIONS: 3130 Define this if you desire to only have use of the NS16550_init 3131 and NS16550_putc functions for the serial driver located at 3132 drivers/serial/ns16550.c. This option is useful for saving 3133 space for already greatly restricted images, including but not 3134 limited to NAND_SPL configurations. 3135 3136- CONFIG_DISPLAY_BOARDINFO 3137 Display information about the board that U-Boot is running on 3138 when U-Boot starts up. The board function checkboard() is called 3139 to do this. 3140 3141- CONFIG_DISPLAY_BOARDINFO_LATE 3142 Similar to the previous option, but display this information 3143 later, once stdio is running and output goes to the LCD, if 3144 present. 3145 3146- CONFIG_BOARD_SIZE_LIMIT: 3147 Maximum size of the U-Boot image. When defined, the 3148 build system checks that the actual size does not 3149 exceed it. 3150 3151Low Level (hardware related) configuration options: 3152--------------------------------------------------- 3153 3154- CONFIG_SYS_CACHELINE_SIZE: 3155 Cache Line Size of the CPU. 3156 3157- CONFIG_SYS_CCSRBAR_DEFAULT: 3158 Default (power-on reset) physical address of CCSR on Freescale 3159 PowerPC SOCs. 3160 3161- CONFIG_SYS_CCSRBAR: 3162 Virtual address of CCSR. On a 32-bit build, this is typically 3163 the same value as CONFIG_SYS_CCSRBAR_DEFAULT. 3164 3165- CONFIG_SYS_CCSRBAR_PHYS: 3166 Physical address of CCSR. CCSR can be relocated to a new 3167 physical address, if desired. In this case, this macro should 3168 be set to that address. Otherwise, it should be set to the 3169 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR 3170 is typically relocated on 36-bit builds. It is recommended 3171 that this macro be defined via the _HIGH and _LOW macros: 3172 3173 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH 3174 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW) 3175 3176- CONFIG_SYS_CCSRBAR_PHYS_HIGH: 3177 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically 3178 either 0 (32-bit build) or 0xF (36-bit build). This macro is 3179 used in assembly code, so it must not contain typecasts or 3180 integer size suffixes (e.g. "ULL"). 3181 3182- CONFIG_SYS_CCSRBAR_PHYS_LOW: 3183 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is 3184 used in assembly code, so it must not contain typecasts or 3185 integer size suffixes (e.g. "ULL"). 3186 3187- CONFIG_SYS_CCSR_DO_NOT_RELOCATE: 3188 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be 3189 forced to a value that ensures that CCSR is not relocated. 3190 3191- Floppy Disk Support: 3192 CONFIG_SYS_FDC_DRIVE_NUMBER 3193 3194 the default drive number (default value 0) 3195 3196 CONFIG_SYS_ISA_IO_STRIDE 3197 3198 defines the spacing between FDC chipset registers 3199 (default value 1) 3200 3201 CONFIG_SYS_ISA_IO_OFFSET 3202 3203 defines the offset of register from address. It 3204 depends on which part of the data bus is connected to 3205 the FDC chipset. (default value 0) 3206 3207 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and 3208 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their 3209 default value. 3210 3211 if CONFIG_SYS_FDC_HW_INIT is defined, then the function 3212 fdc_hw_init() is called at the beginning of the FDC 3213 setup. fdc_hw_init() must be provided by the board 3214 source code. It is used to make hardware-dependent 3215 initializations. 3216 3217- CONFIG_IDE_AHB: 3218 Most IDE controllers were designed to be connected with PCI 3219 interface. Only few of them were designed for AHB interface. 3220 When software is doing ATA command and data transfer to 3221 IDE devices through IDE-AHB controller, some additional 3222 registers accessing to these kind of IDE-AHB controller 3223 is required. 3224 3225- CONFIG_SYS_IMMR: Physical address of the Internal Memory. 3226 DO NOT CHANGE unless you know exactly what you're 3227 doing! (11-4) [MPC8xx systems only] 3228 3229- CONFIG_SYS_INIT_RAM_ADDR: 3230 3231 Start address of memory area that can be used for 3232 initial data and stack; please note that this must be 3233 writable memory that is working WITHOUT special 3234 initialization, i. e. you CANNOT use normal RAM which 3235 will become available only after programming the 3236 memory controller and running certain initialization 3237 sequences. 3238 3239 U-Boot uses the following memory types: 3240 - MPC8xx: IMMR (internal memory of the CPU) 3241 3242- CONFIG_SYS_GBL_DATA_OFFSET: 3243 3244 Offset of the initial data structure in the memory 3245 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually 3246 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial 3247 data is located at the end of the available space 3248 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE - 3249 GENERATED_GBL_DATA_SIZE), and the initial stack is just 3250 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR + 3251 CONFIG_SYS_GBL_DATA_OFFSET) downward. 3252 3253 Note: 3254 On the MPC824X (or other systems that use the data 3255 cache for initial memory) the address chosen for 3256 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must 3257 point to an otherwise UNUSED address space between 3258 the top of RAM and the start of the PCI space. 3259 3260- CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27) 3261 3262- CONFIG_SYS_OR_TIMING_SDRAM: 3263 SDRAM timing 3264 3265- CONFIG_SYS_MAMR_PTA: 3266 periodic timer for refresh 3267 3268- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM, 3269 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP, 3270 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM, 3271 CONFIG_SYS_BR1_PRELIM: 3272 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH) 3273 3274- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE, 3275 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM, 3276 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM: 3277 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM) 3278 3279- CONFIG_PCI_ENUM_ONLY 3280 Only scan through and get the devices on the buses. 3281 Don't do any setup work, presumably because someone or 3282 something has already done it, and we don't need to do it 3283 a second time. Useful for platforms that are pre-booted 3284 by coreboot or similar. 3285 3286- CONFIG_PCI_INDIRECT_BRIDGE: 3287 Enable support for indirect PCI bridges. 3288 3289- CONFIG_SYS_SRIO: 3290 Chip has SRIO or not 3291 3292- CONFIG_SRIO1: 3293 Board has SRIO 1 port available 3294 3295- CONFIG_SRIO2: 3296 Board has SRIO 2 port available 3297 3298- CONFIG_SRIO_PCIE_BOOT_MASTER 3299 Board can support master function for Boot from SRIO and PCIE 3300 3301- CONFIG_SYS_SRIOn_MEM_VIRT: 3302 Virtual Address of SRIO port 'n' memory region 3303 3304- CONFIG_SYS_SRIOn_MEM_PHYS: 3305 Physical Address of SRIO port 'n' memory region 3306 3307- CONFIG_SYS_SRIOn_MEM_SIZE: 3308 Size of SRIO port 'n' memory region 3309 3310- CONFIG_SYS_NAND_BUSWIDTH_16BIT 3311 Defined to tell the NAND controller that the NAND chip is using 3312 a 16 bit bus. 3313 Not all NAND drivers use this symbol. 3314 Example of drivers that use it: 3315 - drivers/mtd/nand/ndfc.c 3316 - drivers/mtd/nand/mxc_nand.c 3317 3318- CONFIG_SYS_NDFC_EBC0_CFG 3319 Sets the EBC0_CFG register for the NDFC. If not defined 3320 a default value will be used. 3321 3322- CONFIG_SPD_EEPROM 3323 Get DDR timing information from an I2C EEPROM. Common 3324 with pluggable memory modules such as SODIMMs 3325 3326 SPD_EEPROM_ADDRESS 3327 I2C address of the SPD EEPROM 3328 3329- CONFIG_SYS_SPD_BUS_NUM 3330 If SPD EEPROM is on an I2C bus other than the first 3331 one, specify here. Note that the value must resolve 3332 to something your driver can deal with. 3333 3334- CONFIG_SYS_DDR_RAW_TIMING 3335 Get DDR timing information from other than SPD. Common with 3336 soldered DDR chips onboard without SPD. DDR raw timing 3337 parameters are extracted from datasheet and hard-coded into 3338 header files or board specific files. 3339 3340- CONFIG_FSL_DDR_INTERACTIVE 3341 Enable interactive DDR debugging. See doc/README.fsl-ddr. 3342 3343- CONFIG_FSL_DDR_SYNC_REFRESH 3344 Enable sync of refresh for multiple controllers. 3345 3346- CONFIG_FSL_DDR_BIST 3347 Enable built-in memory test for Freescale DDR controllers. 3348 3349- CONFIG_SYS_83XX_DDR_USES_CS0 3350 Only for 83xx systems. If specified, then DDR should 3351 be configured using CS0 and CS1 instead of CS2 and CS3. 3352 3353- CONFIG_RMII 3354 Enable RMII mode for all FECs. 3355 Note that this is a global option, we can't 3356 have one FEC in standard MII mode and another in RMII mode. 3357 3358- CONFIG_CRC32_VERIFY 3359 Add a verify option to the crc32 command. 3360 The syntax is: 3361 3362 => crc32 -v <address> <count> <crc32> 3363 3364 Where address/count indicate a memory area 3365 and crc32 is the correct crc32 which the 3366 area should have. 3367 3368- CONFIG_LOOPW 3369 Add the "loopw" memory command. This only takes effect if 3370 the memory commands are activated globally (CONFIG_CMD_MEMORY). 3371 3372- CONFIG_MX_CYCLIC 3373 Add the "mdc" and "mwc" memory commands. These are cyclic 3374 "md/mw" commands. 3375 Examples: 3376 3377 => mdc.b 10 4 500 3378 This command will print 4 bytes (10,11,12,13) each 500 ms. 3379 3380 => mwc.l 100 12345678 10 3381 This command will write 12345678 to address 100 all 10 ms. 3382 3383 This only takes effect if the memory commands are activated 3384 globally (CONFIG_CMD_MEMORY). 3385 3386- CONFIG_SKIP_LOWLEVEL_INIT 3387 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain 3388 low level initializations (like setting up the memory 3389 controller) are omitted and/or U-Boot does not 3390 relocate itself into RAM. 3391 3392 Normally this variable MUST NOT be defined. The only 3393 exception is when U-Boot is loaded (to RAM) by some 3394 other boot loader or by a debugger which performs 3395 these initializations itself. 3396 3397- CONFIG_SKIP_LOWLEVEL_INIT_ONLY 3398 [ARM926EJ-S only] This allows just the call to lowlevel_init() 3399 to be skipped. The normal CP15 init (such as enabling the 3400 instruction cache) is still performed. 3401 3402- CONFIG_SPL_BUILD 3403 Modifies the behaviour of start.S when compiling a loader 3404 that is executed before the actual U-Boot. E.g. when 3405 compiling a NAND SPL. 3406 3407- CONFIG_TPL_BUILD 3408 Modifies the behaviour of start.S when compiling a loader 3409 that is executed after the SPL and before the actual U-Boot. 3410 It is loaded by the SPL. 3411 3412- CONFIG_SYS_MPC85XX_NO_RESETVEC 3413 Only for 85xx systems. If this variable is specified, the section 3414 .resetvec is not kept and the section .bootpg is placed in the 3415 previous 4k of the .text section. 3416 3417- CONFIG_ARCH_MAP_SYSMEM 3418 Generally U-Boot (and in particular the md command) uses 3419 effective address. It is therefore not necessary to regard 3420 U-Boot address as virtual addresses that need to be translated 3421 to physical addresses. However, sandbox requires this, since 3422 it maintains its own little RAM buffer which contains all 3423 addressable memory. This option causes some memory accesses 3424 to be mapped through map_sysmem() / unmap_sysmem(). 3425 3426- CONFIG_X86_RESET_VECTOR 3427 If defined, the x86 reset vector code is included. This is not 3428 needed when U-Boot is running from Coreboot. 3429 3430- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE 3431 Option to disable subpage write in NAND driver 3432 driver that uses this: 3433 drivers/mtd/nand/davinci_nand.c 3434 3435Freescale QE/FMAN Firmware Support: 3436----------------------------------- 3437 3438The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the 3439loading of "firmware", which is encoded in the QE firmware binary format. 3440This firmware often needs to be loaded during U-Boot booting, so macros 3441are used to identify the storage device (NOR flash, SPI, etc) and the address 3442within that device. 3443 3444- CONFIG_SYS_FMAN_FW_ADDR 3445 The address in the storage device where the FMAN microcode is located. The 3446 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3447 is also specified. 3448 3449- CONFIG_SYS_QE_FW_ADDR 3450 The address in the storage device where the QE microcode is located. The 3451 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro 3452 is also specified. 3453 3454- CONFIG_SYS_QE_FMAN_FW_LENGTH 3455 The maximum possible size of the firmware. The firmware binary format 3456 has a field that specifies the actual size of the firmware, but it 3457 might not be possible to read any part of the firmware unless some 3458 local storage is allocated to hold the entire firmware first. 3459 3460- CONFIG_SYS_QE_FMAN_FW_IN_NOR 3461 Specifies that QE/FMAN firmware is located in NOR flash, mapped as 3462 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the 3463 virtual address in NOR flash. 3464 3465- CONFIG_SYS_QE_FMAN_FW_IN_NAND 3466 Specifies that QE/FMAN firmware is located in NAND flash. 3467 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash. 3468 3469- CONFIG_SYS_QE_FMAN_FW_IN_MMC 3470 Specifies that QE/FMAN firmware is located on the primary SD/MMC 3471 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device. 3472 3473- CONFIG_SYS_QE_FMAN_FW_IN_REMOTE 3474 Specifies that QE/FMAN firmware is located in the remote (master) 3475 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which 3476 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound 3477 window->master inbound window->master LAW->the ucode address in 3478 master's memory space. 3479 3480Freescale Layerscape Management Complex Firmware Support: 3481--------------------------------------------------------- 3482The Freescale Layerscape Management Complex (MC) supports the loading of 3483"firmware". 3484This firmware often needs to be loaded during U-Boot booting, so macros 3485are used to identify the storage device (NOR flash, SPI, etc) and the address 3486within that device. 3487 3488- CONFIG_FSL_MC_ENET 3489 Enable the MC driver for Layerscape SoCs. 3490 3491Freescale Layerscape Debug Server Support: 3492------------------------------------------- 3493The Freescale Layerscape Debug Server Support supports the loading of 3494"Debug Server firmware" and triggering SP boot-rom. 3495This firmware often needs to be loaded during U-Boot booting. 3496 3497- CONFIG_SYS_MC_RSV_MEM_ALIGN 3498 Define alignment of reserved memory MC requires 3499 3500Reproducible builds 3501------------------- 3502 3503In order to achieve reproducible builds, timestamps used in the U-Boot build 3504process have to be set to a fixed value. 3505 3506This is done using the SOURCE_DATE_EPOCH environment variable. 3507SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration 3508option for U-Boot or an environment variable in U-Boot. 3509 3510SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC. 3511 3512Building the Software: 3513====================== 3514 3515Building U-Boot has been tested in several native build environments 3516and in many different cross environments. Of course we cannot support 3517all possibly existing versions of cross development tools in all 3518(potentially obsolete) versions. In case of tool chain problems we 3519recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK) 3520which is extensively used to build and test U-Boot. 3521 3522If you are not using a native environment, it is assumed that you 3523have GNU cross compiling tools available in your path. In this case, 3524you must set the environment variable CROSS_COMPILE in your shell. 3525Note that no changes to the Makefile or any other source files are 3526necessary. For example using the ELDK on a 4xx CPU, please enter: 3527 3528 $ CROSS_COMPILE=ppc_4xx- 3529 $ export CROSS_COMPILE 3530 3531Note: If you wish to generate Windows versions of the utilities in 3532 the tools directory you can use the MinGW toolchain 3533 (http://www.mingw.org). Set your HOST tools to the MinGW 3534 toolchain and execute 'make tools'. For example: 3535 3536 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools 3537 3538 Binaries such as tools/mkimage.exe will be created which can 3539 be executed on computers running Windows. 3540 3541U-Boot is intended to be simple to build. After installing the 3542sources you must configure U-Boot for one specific board type. This 3543is done by typing: 3544 3545 make NAME_defconfig 3546 3547where "NAME_defconfig" is the name of one of the existing configu- 3548rations; see boards.cfg for supported names. 3549 3550Note: for some board special configuration names may exist; check if 3551 additional information is available from the board vendor; for 3552 instance, the TQM823L systems are available without (standard) 3553 or with LCD support. You can select such additional "features" 3554 when choosing the configuration, i. e. 3555 3556 make TQM823L_defconfig 3557 - will configure for a plain TQM823L, i. e. no LCD support 3558 3559 make TQM823L_LCD_defconfig 3560 - will configure for a TQM823L with U-Boot console on LCD 3561 3562 etc. 3563 3564 3565Finally, type "make all", and you should get some working U-Boot 3566images ready for download to / installation on your system: 3567 3568- "u-boot.bin" is a raw binary image 3569- "u-boot" is an image in ELF binary format 3570- "u-boot.srec" is in Motorola S-Record format 3571 3572By default the build is performed locally and the objects are saved 3573in the source directory. One of the two methods can be used to change 3574this behavior and build U-Boot to some external directory: 3575 35761. Add O= to the make command line invocations: 3577 3578 make O=/tmp/build distclean 3579 make O=/tmp/build NAME_defconfig 3580 make O=/tmp/build all 3581 35822. Set environment variable KBUILD_OUTPUT to point to the desired location: 3583 3584 export KBUILD_OUTPUT=/tmp/build 3585 make distclean 3586 make NAME_defconfig 3587 make all 3588 3589Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment 3590variable. 3591 3592User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by 3593setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS. 3594For example to treat all compiler warnings as errors: 3595 3596 make KCFLAGS=-Werror 3597 3598Please be aware that the Makefiles assume you are using GNU make, so 3599for instance on NetBSD you might need to use "gmake" instead of 3600native "make". 3601 3602 3603If the system board that you have is not listed, then you will need 3604to port U-Boot to your hardware platform. To do this, follow these 3605steps: 3606 36071. Create a new directory to hold your board specific code. Add any 3608 files you need. In your board directory, you will need at least 3609 the "Makefile" and a "<board>.c". 36102. Create a new configuration file "include/configs/<board>.h" for 3611 your board. 36123. If you're porting U-Boot to a new CPU, then also create a new 3613 directory to hold your CPU specific code. Add any files you need. 36144. Run "make <board>_defconfig" with your new name. 36155. Type "make", and you should get a working "u-boot.srec" file 3616 to be installed on your target system. 36176. Debug and solve any problems that might arise. 3618 [Of course, this last step is much harder than it sounds.] 3619 3620 3621Testing of U-Boot Modifications, Ports to New Hardware, etc.: 3622============================================================== 3623 3624If you have modified U-Boot sources (for instance added a new board 3625or support for new devices, a new CPU, etc.) you are expected to 3626provide feedback to the other developers. The feedback normally takes 3627the form of a "patch", i. e. a context diff against a certain (latest 3628official or latest in the git repository) version of U-Boot sources. 3629 3630But before you submit such a patch, please verify that your modifi- 3631cation did not break existing code. At least make sure that *ALL* of 3632the supported boards compile WITHOUT ANY compiler warnings. To do so, 3633just run the buildman script (tools/buildman/buildman), which will 3634configure and build U-Boot for ALL supported system. Be warned, this 3635will take a while. Please see the buildman README, or run 'buildman -H' 3636for documentation. 3637 3638 3639See also "U-Boot Porting Guide" below. 3640 3641 3642Monitor Commands - Overview: 3643============================ 3644 3645go - start application at address 'addr' 3646run - run commands in an environment variable 3647bootm - boot application image from memory 3648bootp - boot image via network using BootP/TFTP protocol 3649bootz - boot zImage from memory 3650tftpboot- boot image via network using TFTP protocol 3651 and env variables "ipaddr" and "serverip" 3652 (and eventually "gatewayip") 3653tftpput - upload a file via network using TFTP protocol 3654rarpboot- boot image via network using RARP/TFTP protocol 3655diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd' 3656loads - load S-Record file over serial line 3657loadb - load binary file over serial line (kermit mode) 3658md - memory display 3659mm - memory modify (auto-incrementing) 3660nm - memory modify (constant address) 3661mw - memory write (fill) 3662cp - memory copy 3663cmp - memory compare 3664crc32 - checksum calculation 3665i2c - I2C sub-system 3666sspi - SPI utility commands 3667base - print or set address offset 3668printenv- print environment variables 3669setenv - set environment variables 3670saveenv - save environment variables to persistent storage 3671protect - enable or disable FLASH write protection 3672erase - erase FLASH memory 3673flinfo - print FLASH memory information 3674nand - NAND memory operations (see doc/README.nand) 3675bdinfo - print Board Info structure 3676iminfo - print header information for application image 3677coninfo - print console devices and informations 3678ide - IDE sub-system 3679loop - infinite loop on address range 3680loopw - infinite write loop on address range 3681mtest - simple RAM test 3682icache - enable or disable instruction cache 3683dcache - enable or disable data cache 3684reset - Perform RESET of the CPU 3685echo - echo args to console 3686version - print monitor version 3687help - print online help 3688? - alias for 'help' 3689 3690 3691Monitor Commands - Detailed Description: 3692======================================== 3693 3694TODO. 3695 3696For now: just type "help <command>". 3697 3698 3699Environment Variables: 3700====================== 3701 3702U-Boot supports user configuration using Environment Variables which 3703can be made persistent by saving to Flash memory. 3704 3705Environment Variables are set using "setenv", printed using 3706"printenv", and saved to Flash using "saveenv". Using "setenv" 3707without a value can be used to delete a variable from the 3708environment. As long as you don't save the environment you are 3709working with an in-memory copy. In case the Flash area containing the 3710environment is erased by accident, a default environment is provided. 3711 3712Some configuration options can be set using Environment Variables. 3713 3714List of environment variables (most likely not complete): 3715 3716 baudrate - see CONFIG_BAUDRATE 3717 3718 bootdelay - see CONFIG_BOOTDELAY 3719 3720 bootcmd - see CONFIG_BOOTCOMMAND 3721 3722 bootargs - Boot arguments when booting an RTOS image 3723 3724 bootfile - Name of the image to load with TFTP 3725 3726 bootm_low - Memory range available for image processing in the bootm 3727 command can be restricted. This variable is given as 3728 a hexadecimal number and defines lowest address allowed 3729 for use by the bootm command. See also "bootm_size" 3730 environment variable. Address defined by "bootm_low" is 3731 also the base of the initial memory mapping for the Linux 3732 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and 3733 bootm_mapsize. 3734 3735 bootm_mapsize - Size of the initial memory mapping for the Linux kernel. 3736 This variable is given as a hexadecimal number and it 3737 defines the size of the memory region starting at base 3738 address bootm_low that is accessible by the Linux kernel 3739 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used 3740 as the default value if it is defined, and bootm_size is 3741 used otherwise. 3742 3743 bootm_size - Memory range available for image processing in the bootm 3744 command can be restricted. This variable is given as 3745 a hexadecimal number and defines the size of the region 3746 allowed for use by the bootm command. See also "bootm_low" 3747 environment variable. 3748 3749 updatefile - Location of the software update file on a TFTP server, used 3750 by the automatic software update feature. Please refer to 3751 documentation in doc/README.update for more details. 3752 3753 autoload - if set to "no" (any string beginning with 'n'), 3754 "bootp" will just load perform a lookup of the 3755 configuration from the BOOTP server, but not try to 3756 load any image using TFTP 3757 3758 autostart - if set to "yes", an image loaded using the "bootp", 3759 "rarpboot", "tftpboot" or "diskboot" commands will 3760 be automatically started (by internally calling 3761 "bootm") 3762 3763 If set to "no", a standalone image passed to the 3764 "bootm" command will be copied to the load address 3765 (and eventually uncompressed), but NOT be started. 3766 This can be used to load and uncompress arbitrary 3767 data. 3768 3769 fdt_high - if set this restricts the maximum address that the 3770 flattened device tree will be copied into upon boot. 3771 For example, if you have a system with 1 GB memory 3772 at physical address 0x10000000, while Linux kernel 3773 only recognizes the first 704 MB as low memory, you 3774 may need to set fdt_high as 0x3C000000 to have the 3775 device tree blob be copied to the maximum address 3776 of the 704 MB low memory, so that Linux kernel can 3777 access it during the boot procedure. 3778 3779 If this is set to the special value 0xFFFFFFFF then 3780 the fdt will not be copied at all on boot. For this 3781 to work it must reside in writable memory, have 3782 sufficient padding on the end of it for u-boot to 3783 add the information it needs into it, and the memory 3784 must be accessible by the kernel. 3785 3786 fdtcontroladdr- if set this is the address of the control flattened 3787 device tree used by U-Boot when CONFIG_OF_CONTROL is 3788 defined. 3789 3790 i2cfast - (PPC405GP|PPC405EP only) 3791 if set to 'y' configures Linux I2C driver for fast 3792 mode (400kHZ). This environment variable is used in 3793 initialization code. So, for changes to be effective 3794 it must be saved and board must be reset. 3795 3796 initrd_high - restrict positioning of initrd images: 3797 If this variable is not set, initrd images will be 3798 copied to the highest possible address in RAM; this 3799 is usually what you want since it allows for 3800 maximum initrd size. If for some reason you want to 3801 make sure that the initrd image is loaded below the 3802 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment 3803 variable to a value of "no" or "off" or "0". 3804 Alternatively, you can set it to a maximum upper 3805 address to use (U-Boot will still check that it 3806 does not overwrite the U-Boot stack and data). 3807 3808 For instance, when you have a system with 16 MB 3809 RAM, and want to reserve 4 MB from use by Linux, 3810 you can do this by adding "mem=12M" to the value of 3811 the "bootargs" variable. However, now you must make 3812 sure that the initrd image is placed in the first 3813 12 MB as well - this can be done with 3814 3815 setenv initrd_high 00c00000 3816 3817 If you set initrd_high to 0xFFFFFFFF, this is an 3818 indication to U-Boot that all addresses are legal 3819 for the Linux kernel, including addresses in flash 3820 memory. In this case U-Boot will NOT COPY the 3821 ramdisk at all. This may be useful to reduce the 3822 boot time on your system, but requires that this 3823 feature is supported by your Linux kernel. 3824 3825 ipaddr - IP address; needed for tftpboot command 3826 3827 loadaddr - Default load address for commands like "bootp", 3828 "rarpboot", "tftpboot", "loadb" or "diskboot" 3829 3830 loads_echo - see CONFIG_LOADS_ECHO 3831 3832 serverip - TFTP server IP address; needed for tftpboot command 3833 3834 bootretry - see CONFIG_BOOT_RETRY_TIME 3835 3836 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR 3837 3838 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR 3839 3840 ethprime - controls which interface is used first. 3841 3842 ethact - controls which interface is currently active. 3843 For example you can do the following 3844 3845 => setenv ethact FEC 3846 => ping 192.168.0.1 # traffic sent on FEC 3847 => setenv ethact SCC 3848 => ping 10.0.0.1 # traffic sent on SCC 3849 3850 ethrotate - When set to "no" U-Boot does not go through all 3851 available network interfaces. 3852 It just stays at the currently selected interface. 3853 3854 netretry - When set to "no" each network operation will 3855 either succeed or fail without retrying. 3856 When set to "once" the network operation will 3857 fail when all the available network interfaces 3858 are tried once without success. 3859 Useful on scripts which control the retry operation 3860 themselves. 3861 3862 npe_ucode - set load address for the NPE microcode 3863 3864 silent_linux - If set then Linux will be told to boot silently, by 3865 changing the console to be empty. If "yes" it will be 3866 made silent. If "no" it will not be made silent. If 3867 unset, then it will be made silent if the U-Boot console 3868 is silent. 3869 3870 tftpsrcp - If this is set, the value is used for TFTP's 3871 UDP source port. 3872 3873 tftpdstp - If this is set, the value is used for TFTP's UDP 3874 destination port instead of the Well Know Port 69. 3875 3876 tftpblocksize - Block size to use for TFTP transfers; if not set, 3877 we use the TFTP server's default block size 3878 3879 tftptimeout - Retransmission timeout for TFTP packets (in milli- 3880 seconds, minimum value is 1000 = 1 second). Defines 3881 when a packet is considered to be lost so it has to 3882 be retransmitted. The default is 5000 = 5 seconds. 3883 Lowering this value may make downloads succeed 3884 faster in networks with high packet loss rates or 3885 with unreliable TFTP servers. 3886 3887 tftptimeoutcountmax - maximum count of TFTP timeouts (no 3888 unit, minimum value = 0). Defines how many timeouts 3889 can happen during a single file transfer before that 3890 transfer is aborted. The default is 10, and 0 means 3891 'no timeouts allowed'. Increasing this value may help 3892 downloads succeed with high packet loss rates, or with 3893 unreliable TFTP servers or client hardware. 3894 3895 vlan - When set to a value < 4095 the traffic over 3896 Ethernet is encapsulated/received over 802.1q 3897 VLAN tagged frames. 3898 3899 bootpretryperiod - Period during which BOOTP/DHCP sends retries. 3900 Unsigned value, in milliseconds. If not set, the period will 3901 be either the default (28000), or a value based on 3902 CONFIG_NET_RETRY_COUNT, if defined. This value has 3903 precedence over the valu based on CONFIG_NET_RETRY_COUNT. 3904 3905The following image location variables contain the location of images 3906used in booting. The "Image" column gives the role of the image and is 3907not an environment variable name. The other columns are environment 3908variable names. "File Name" gives the name of the file on a TFTP 3909server, "RAM Address" gives the location in RAM the image will be 3910loaded to, and "Flash Location" gives the image's address in NOR 3911flash or offset in NAND flash. 3912 3913*Note* - these variables don't have to be defined for all boards, some 3914boards currently use other variables for these purposes, and some 3915boards use these variables for other purposes. 3916 3917Image File Name RAM Address Flash Location 3918----- --------- ----------- -------------- 3919u-boot u-boot u-boot_addr_r u-boot_addr 3920Linux kernel bootfile kernel_addr_r kernel_addr 3921device tree blob fdtfile fdt_addr_r fdt_addr 3922ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr 3923 3924The following environment variables may be used and automatically 3925updated by the network boot commands ("bootp" and "rarpboot"), 3926depending the information provided by your boot server: 3927 3928 bootfile - see above 3929 dnsip - IP address of your Domain Name Server 3930 dnsip2 - IP address of your secondary Domain Name Server 3931 gatewayip - IP address of the Gateway (Router) to use 3932 hostname - Target hostname 3933 ipaddr - see above 3934 netmask - Subnet Mask 3935 rootpath - Pathname of the root filesystem on the NFS server 3936 serverip - see above 3937 3938 3939There are two special Environment Variables: 3940 3941 serial# - contains hardware identification information such 3942 as type string and/or serial number 3943 ethaddr - Ethernet address 3944 3945These variables can be set only once (usually during manufacturing of 3946the board). U-Boot refuses to delete or overwrite these variables 3947once they have been set once. 3948 3949 3950Further special Environment Variables: 3951 3952 ver - Contains the U-Boot version string as printed 3953 with the "version" command. This variable is 3954 readonly (see CONFIG_VERSION_VARIABLE). 3955 3956 3957Please note that changes to some configuration parameters may take 3958only effect after the next boot (yes, that's just like Windoze :-). 3959 3960 3961Callback functions for environment variables: 3962--------------------------------------------- 3963 3964For some environment variables, the behavior of u-boot needs to change 3965when their values are changed. This functionality allows functions to 3966be associated with arbitrary variables. On creation, overwrite, or 3967deletion, the callback will provide the opportunity for some side 3968effect to happen or for the change to be rejected. 3969 3970The callbacks are named and associated with a function using the 3971U_BOOT_ENV_CALLBACK macro in your board or driver code. 3972 3973These callbacks are associated with variables in one of two ways. The 3974static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC 3975in the board configuration to a string that defines a list of 3976associations. The list must be in the following format: 3977 3978 entry = variable_name[:callback_name] 3979 list = entry[,list] 3980 3981If the callback name is not specified, then the callback is deleted. 3982Spaces are also allowed anywhere in the list. 3983 3984Callbacks can also be associated by defining the ".callbacks" variable 3985with the same list format above. Any association in ".callbacks" will 3986override any association in the static list. You can define 3987CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the 3988".callbacks" environment variable in the default or embedded environment. 3989 3990If CONFIG_REGEX is defined, the variable_name above is evaluated as a 3991regular expression. This allows multiple variables to be connected to 3992the same callback without explicitly listing them all out. 3993 3994 3995Command Line Parsing: 3996===================== 3997 3998There are two different command line parsers available with U-Boot: 3999the old "simple" one, and the much more powerful "hush" shell: 4000 4001Old, simple command line parser: 4002-------------------------------- 4003 4004- supports environment variables (through setenv / saveenv commands) 4005- several commands on one line, separated by ';' 4006- variable substitution using "... ${name} ..." syntax 4007- special characters ('$', ';') can be escaped by prefixing with '\', 4008 for example: 4009 setenv bootcmd bootm \${address} 4010- You can also escape text by enclosing in single apostrophes, for example: 4011 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off' 4012 4013Hush shell: 4014----------- 4015 4016- similar to Bourne shell, with control structures like 4017 if...then...else...fi, for...do...done; while...do...done, 4018 until...do...done, ... 4019- supports environment ("global") variables (through setenv / saveenv 4020 commands) and local shell variables (through standard shell syntax 4021 "name=value"); only environment variables can be used with "run" 4022 command 4023 4024General rules: 4025-------------- 4026 4027(1) If a command line (or an environment variable executed by a "run" 4028 command) contains several commands separated by semicolon, and 4029 one of these commands fails, then the remaining commands will be 4030 executed anyway. 4031 4032(2) If you execute several variables with one call to run (i. e. 4033 calling run with a list of variables as arguments), any failing 4034 command will cause "run" to terminate, i. e. the remaining 4035 variables are not executed. 4036 4037Note for Redundant Ethernet Interfaces: 4038======================================= 4039 4040Some boards come with redundant Ethernet interfaces; U-Boot supports 4041such configurations and is capable of automatic selection of a 4042"working" interface when needed. MAC assignment works as follows: 4043 4044Network interfaces are numbered eth0, eth1, eth2, ... Corresponding 4045MAC addresses can be stored in the environment as "ethaddr" (=>eth0), 4046"eth1addr" (=>eth1), "eth2addr", ... 4047 4048If the network interface stores some valid MAC address (for instance 4049in SROM), this is used as default address if there is NO correspon- 4050ding setting in the environment; if the corresponding environment 4051variable is set, this overrides the settings in the card; that means: 4052 4053o If the SROM has a valid MAC address, and there is no address in the 4054 environment, the SROM's address is used. 4055 4056o If there is no valid address in the SROM, and a definition in the 4057 environment exists, then the value from the environment variable is 4058 used. 4059 4060o If both the SROM and the environment contain a MAC address, and 4061 both addresses are the same, this MAC address is used. 4062 4063o If both the SROM and the environment contain a MAC address, and the 4064 addresses differ, the value from the environment is used and a 4065 warning is printed. 4066 4067o If neither SROM nor the environment contain a MAC address, an error 4068 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case 4069 a random, locally-assigned MAC is used. 4070 4071If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses 4072will be programmed into hardware as part of the initialization process. This 4073may be skipped by setting the appropriate 'ethmacskip' environment variable. 4074The naming convention is as follows: 4075"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc. 4076 4077Image Formats: 4078============== 4079 4080U-Boot is capable of booting (and performing other auxiliary operations on) 4081images in two formats: 4082 4083New uImage format (FIT) 4084----------------------- 4085 4086Flexible and powerful format based on Flattened Image Tree -- FIT (similar 4087to Flattened Device Tree). It allows the use of images with multiple 4088components (several kernels, ramdisks, etc.), with contents protected by 4089SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory. 4090 4091 4092Old uImage format 4093----------------- 4094 4095Old image format is based on binary files which can be basically anything, 4096preceded by a special header; see the definitions in include/image.h for 4097details; basically, the header defines the following image properties: 4098 4099* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD, 4100 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks, 4101 LynxOS, pSOS, QNX, RTEMS, INTEGRITY; 4102 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS, 4103 INTEGRITY). 4104* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86, 4105 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit; 4106 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC). 4107* Compression Type (uncompressed, gzip, bzip2) 4108* Load Address 4109* Entry Point 4110* Image Name 4111* Image Timestamp 4112 4113The header is marked by a special Magic Number, and both the header 4114and the data portions of the image are secured against corruption by 4115CRC32 checksums. 4116 4117 4118Linux Support: 4119============== 4120 4121Although U-Boot should support any OS or standalone application 4122easily, the main focus has always been on Linux during the design of 4123U-Boot. 4124 4125U-Boot includes many features that so far have been part of some 4126special "boot loader" code within the Linux kernel. Also, any 4127"initrd" images to be used are no longer part of one big Linux image; 4128instead, kernel and "initrd" are separate images. This implementation 4129serves several purposes: 4130 4131- the same features can be used for other OS or standalone 4132 applications (for instance: using compressed images to reduce the 4133 Flash memory footprint) 4134 4135- it becomes much easier to port new Linux kernel versions because 4136 lots of low-level, hardware dependent stuff are done by U-Boot 4137 4138- the same Linux kernel image can now be used with different "initrd" 4139 images; of course this also means that different kernel images can 4140 be run with the same "initrd". This makes testing easier (you don't 4141 have to build a new "zImage.initrd" Linux image when you just 4142 change a file in your "initrd"). Also, a field-upgrade of the 4143 software is easier now. 4144 4145 4146Linux HOWTO: 4147============ 4148 4149Porting Linux to U-Boot based systems: 4150--------------------------------------- 4151 4152U-Boot cannot save you from doing all the necessary modifications to 4153configure the Linux device drivers for use with your target hardware 4154(no, we don't intend to provide a full virtual machine interface to 4155Linux :-). 4156 4157But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot). 4158 4159Just make sure your machine specific header file (for instance 4160include/asm-ppc/tqm8xx.h) includes the same definition of the Board 4161Information structure as we define in include/asm-<arch>/u-boot.h, 4162and make sure that your definition of IMAP_ADDR uses the same value 4163as your U-Boot configuration in CONFIG_SYS_IMMR. 4164 4165Note that U-Boot now has a driver model, a unified model for drivers. 4166If you are adding a new driver, plumb it into driver model. If there 4167is no uclass available, you are encouraged to create one. See 4168doc/driver-model. 4169 4170 4171Configuring the Linux kernel: 4172----------------------------- 4173 4174No specific requirements for U-Boot. Make sure you have some root 4175device (initial ramdisk, NFS) for your target system. 4176 4177 4178Building a Linux Image: 4179----------------------- 4180 4181With U-Boot, "normal" build targets like "zImage" or "bzImage" are 4182not used. If you use recent kernel source, a new build target 4183"uImage" will exist which automatically builds an image usable by 4184U-Boot. Most older kernels also have support for a "pImage" target, 4185which was introduced for our predecessor project PPCBoot and uses a 4186100% compatible format. 4187 4188Example: 4189 4190 make TQM850L_defconfig 4191 make oldconfig 4192 make dep 4193 make uImage 4194 4195The "uImage" build target uses a special tool (in 'tools/mkimage') to 4196encapsulate a compressed Linux kernel image with header information, 4197CRC32 checksum etc. for use with U-Boot. This is what we are doing: 4198 4199* build a standard "vmlinux" kernel image (in ELF binary format): 4200 4201* convert the kernel into a raw binary image: 4202 4203 ${CROSS_COMPILE}-objcopy -O binary \ 4204 -R .note -R .comment \ 4205 -S vmlinux linux.bin 4206 4207* compress the binary image: 4208 4209 gzip -9 linux.bin 4210 4211* package compressed binary image for U-Boot: 4212 4213 mkimage -A ppc -O linux -T kernel -C gzip \ 4214 -a 0 -e 0 -n "Linux Kernel Image" \ 4215 -d linux.bin.gz uImage 4216 4217 4218The "mkimage" tool can also be used to create ramdisk images for use 4219with U-Boot, either separated from the Linux kernel image, or 4220combined into one file. "mkimage" encapsulates the images with a 64 4221byte header containing information about target architecture, 4222operating system, image type, compression method, entry points, time 4223stamp, CRC32 checksums, etc. 4224 4225"mkimage" can be called in two ways: to verify existing images and 4226print the header information, or to build new images. 4227 4228In the first form (with "-l" option) mkimage lists the information 4229contained in the header of an existing U-Boot image; this includes 4230checksum verification: 4231 4232 tools/mkimage -l image 4233 -l ==> list image header information 4234 4235The second form (with "-d" option) is used to build a U-Boot image 4236from a "data file" which is used as image payload: 4237 4238 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \ 4239 -n name -d data_file image 4240 -A ==> set architecture to 'arch' 4241 -O ==> set operating system to 'os' 4242 -T ==> set image type to 'type' 4243 -C ==> set compression type 'comp' 4244 -a ==> set load address to 'addr' (hex) 4245 -e ==> set entry point to 'ep' (hex) 4246 -n ==> set image name to 'name' 4247 -d ==> use image data from 'datafile' 4248 4249Right now, all Linux kernels for PowerPC systems use the same load 4250address (0x00000000), but the entry point address depends on the 4251kernel version: 4252 4253- 2.2.x kernels have the entry point at 0x0000000C, 4254- 2.3.x and later kernels have the entry point at 0x00000000. 4255 4256So a typical call to build a U-Boot image would read: 4257 4258 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4259 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \ 4260 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \ 4261 > examples/uImage.TQM850L 4262 Image Name: 2.4.4 kernel for TQM850L 4263 Created: Wed Jul 19 02:34:59 2000 4264 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4265 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4266 Load Address: 0x00000000 4267 Entry Point: 0x00000000 4268 4269To verify the contents of the image (or check for corruption): 4270 4271 -> tools/mkimage -l examples/uImage.TQM850L 4272 Image Name: 2.4.4 kernel for TQM850L 4273 Created: Wed Jul 19 02:34:59 2000 4274 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4275 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB 4276 Load Address: 0x00000000 4277 Entry Point: 0x00000000 4278 4279NOTE: for embedded systems where boot time is critical you can trade 4280speed for memory and install an UNCOMPRESSED image instead: this 4281needs more space in Flash, but boots much faster since it does not 4282need to be uncompressed: 4283 4284 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz 4285 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \ 4286 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \ 4287 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \ 4288 > examples/uImage.TQM850L-uncompressed 4289 Image Name: 2.4.4 kernel for TQM850L 4290 Created: Wed Jul 19 02:34:59 2000 4291 Image Type: PowerPC Linux Kernel Image (uncompressed) 4292 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB 4293 Load Address: 0x00000000 4294 Entry Point: 0x00000000 4295 4296 4297Similar you can build U-Boot images from a 'ramdisk.image.gz' file 4298when your kernel is intended to use an initial ramdisk: 4299 4300 -> tools/mkimage -n 'Simple Ramdisk Image' \ 4301 > -A ppc -O linux -T ramdisk -C gzip \ 4302 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd 4303 Image Name: Simple Ramdisk Image 4304 Created: Wed Jan 12 14:01:50 2000 4305 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4306 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB 4307 Load Address: 0x00000000 4308 Entry Point: 0x00000000 4309 4310The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i" 4311option performs the converse operation of the mkimage's second form (the "-d" 4312option). Given an image built by mkimage, the dumpimage extracts a "data file" 4313from the image: 4314 4315 tools/dumpimage -i image -T type -p position data_file 4316 -i ==> extract from the 'image' a specific 'data_file' 4317 -T ==> set image type to 'type' 4318 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image' 4319 4320 4321Installing a Linux Image: 4322------------------------- 4323 4324To downloading a U-Boot image over the serial (console) interface, 4325you must convert the image to S-Record format: 4326 4327 objcopy -I binary -O srec examples/image examples/image.srec 4328 4329The 'objcopy' does not understand the information in the U-Boot 4330image header, so the resulting S-Record file will be relative to 4331address 0x00000000. To load it to a given address, you need to 4332specify the target address as 'offset' parameter with the 'loads' 4333command. 4334 4335Example: install the image to address 0x40100000 (which on the 4336TQM8xxL is in the first Flash bank): 4337 4338 => erase 40100000 401FFFFF 4339 4340 .......... done 4341 Erased 8 sectors 4342 4343 => loads 40100000 4344 ## Ready for S-Record download ... 4345 ~>examples/image.srec 4346 1 2 3 4 5 6 7 8 9 10 11 12 13 ... 4347 ... 4348 15989 15990 15991 15992 4349 [file transfer complete] 4350 [connected] 4351 ## Start Addr = 0x00000000 4352 4353 4354You can check the success of the download using the 'iminfo' command; 4355this includes a checksum verification so you can be sure no data 4356corruption happened: 4357 4358 => imi 40100000 4359 4360 ## Checking Image at 40100000 ... 4361 Image Name: 2.2.13 for initrd on TQM850L 4362 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4363 Data Size: 335725 Bytes = 327 kB = 0 MB 4364 Load Address: 00000000 4365 Entry Point: 0000000c 4366 Verifying Checksum ... OK 4367 4368 4369Boot Linux: 4370----------- 4371 4372The "bootm" command is used to boot an application that is stored in 4373memory (RAM or Flash). In case of a Linux kernel image, the contents 4374of the "bootargs" environment variable is passed to the kernel as 4375parameters. You can check and modify this variable using the 4376"printenv" and "setenv" commands: 4377 4378 4379 => printenv bootargs 4380 bootargs=root=/dev/ram 4381 4382 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4383 4384 => printenv bootargs 4385 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4386 4387 => bootm 40020000 4388 ## Booting Linux kernel at 40020000 ... 4389 Image Name: 2.2.13 for NFS on TQM850L 4390 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4391 Data Size: 381681 Bytes = 372 kB = 0 MB 4392 Load Address: 00000000 4393 Entry Point: 0000000c 4394 Verifying Checksum ... OK 4395 Uncompressing Kernel Image ... OK 4396 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 4397 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2 4398 time_init: decrementer frequency = 187500000/60 4399 Calibrating delay loop... 49.77 BogoMIPS 4400 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000] 4401 ... 4402 4403If you want to boot a Linux kernel with initial RAM disk, you pass 4404the memory addresses of both the kernel and the initrd image (PPBCOOT 4405format!) to the "bootm" command: 4406 4407 => imi 40100000 40200000 4408 4409 ## Checking Image at 40100000 ... 4410 Image Name: 2.2.13 for initrd on TQM850L 4411 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4412 Data Size: 335725 Bytes = 327 kB = 0 MB 4413 Load Address: 00000000 4414 Entry Point: 0000000c 4415 Verifying Checksum ... OK 4416 4417 ## Checking Image at 40200000 ... 4418 Image Name: Simple Ramdisk Image 4419 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4420 Data Size: 566530 Bytes = 553 kB = 0 MB 4421 Load Address: 00000000 4422 Entry Point: 00000000 4423 Verifying Checksum ... OK 4424 4425 => bootm 40100000 40200000 4426 ## Booting Linux kernel at 40100000 ... 4427 Image Name: 2.2.13 for initrd on TQM850L 4428 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4429 Data Size: 335725 Bytes = 327 kB = 0 MB 4430 Load Address: 00000000 4431 Entry Point: 0000000c 4432 Verifying Checksum ... OK 4433 Uncompressing Kernel Image ... OK 4434 ## Loading RAMDisk Image at 40200000 ... 4435 Image Name: Simple Ramdisk Image 4436 Image Type: PowerPC Linux RAMDisk Image (gzip compressed) 4437 Data Size: 566530 Bytes = 553 kB = 0 MB 4438 Load Address: 00000000 4439 Entry Point: 00000000 4440 Verifying Checksum ... OK 4441 Loading Ramdisk ... OK 4442 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 4443 Boot arguments: root=/dev/ram 4444 time_init: decrementer frequency = 187500000/60 4445 Calibrating delay loop... 49.77 BogoMIPS 4446 ... 4447 RAMDISK: Compressed image found at block 0 4448 VFS: Mounted root (ext2 filesystem). 4449 4450 bash# 4451 4452Boot Linux and pass a flat device tree: 4453----------- 4454 4455First, U-Boot must be compiled with the appropriate defines. See the section 4456titled "Linux Kernel Interface" above for a more in depth explanation. The 4457following is an example of how to start a kernel and pass an updated 4458flat device tree: 4459 4460=> print oftaddr 4461oftaddr=0x300000 4462=> print oft 4463oft=oftrees/mpc8540ads.dtb 4464=> tftp $oftaddr $oft 4465Speed: 1000, full duplex 4466Using TSEC0 device 4467TFTP from server 192.168.1.1; our IP address is 192.168.1.101 4468Filename 'oftrees/mpc8540ads.dtb'. 4469Load address: 0x300000 4470Loading: # 4471done 4472Bytes transferred = 4106 (100a hex) 4473=> tftp $loadaddr $bootfile 4474Speed: 1000, full duplex 4475Using TSEC0 device 4476TFTP from server 192.168.1.1; our IP address is 192.168.1.2 4477Filename 'uImage'. 4478Load address: 0x200000 4479Loading:############ 4480done 4481Bytes transferred = 1029407 (fb51f hex) 4482=> print loadaddr 4483loadaddr=200000 4484=> print oftaddr 4485oftaddr=0x300000 4486=> bootm $loadaddr - $oftaddr 4487## Booting image at 00200000 ... 4488 Image Name: Linux-2.6.17-dirty 4489 Image Type: PowerPC Linux Kernel Image (gzip compressed) 4490 Data Size: 1029343 Bytes = 1005.2 kB 4491 Load Address: 00000000 4492 Entry Point: 00000000 4493 Verifying Checksum ... OK 4494 Uncompressing Kernel Image ... OK 4495Booting using flat device tree at 0x300000 4496Using MPC85xx ADS machine description 4497Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb 4498[snip] 4499 4500 4501More About U-Boot Image Types: 4502------------------------------ 4503 4504U-Boot supports the following image types: 4505 4506 "Standalone Programs" are directly runnable in the environment 4507 provided by U-Boot; it is expected that (if they behave 4508 well) you can continue to work in U-Boot after return from 4509 the Standalone Program. 4510 "OS Kernel Images" are usually images of some Embedded OS which 4511 will take over control completely. Usually these programs 4512 will install their own set of exception handlers, device 4513 drivers, set up the MMU, etc. - this means, that you cannot 4514 expect to re-enter U-Boot except by resetting the CPU. 4515 "RAMDisk Images" are more or less just data blocks, and their 4516 parameters (address, size) are passed to an OS kernel that is 4517 being started. 4518 "Multi-File Images" contain several images, typically an OS 4519 (Linux) kernel image and one or more data images like 4520 RAMDisks. This construct is useful for instance when you want 4521 to boot over the network using BOOTP etc., where the boot 4522 server provides just a single image file, but you want to get 4523 for instance an OS kernel and a RAMDisk image. 4524 4525 "Multi-File Images" start with a list of image sizes, each 4526 image size (in bytes) specified by an "uint32_t" in network 4527 byte order. This list is terminated by an "(uint32_t)0". 4528 Immediately after the terminating 0 follow the images, one by 4529 one, all aligned on "uint32_t" boundaries (size rounded up to 4530 a multiple of 4 bytes). 4531 4532 "Firmware Images" are binary images containing firmware (like 4533 U-Boot or FPGA images) which usually will be programmed to 4534 flash memory. 4535 4536 "Script files" are command sequences that will be executed by 4537 U-Boot's command interpreter; this feature is especially 4538 useful when you configure U-Boot to use a real shell (hush) 4539 as command interpreter. 4540 4541Booting the Linux zImage: 4542------------------------- 4543 4544On some platforms, it's possible to boot Linux zImage. This is done 4545using the "bootz" command. The syntax of "bootz" command is the same 4546as the syntax of "bootm" command. 4547 4548Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply 4549kernel with raw initrd images. The syntax is slightly different, the 4550address of the initrd must be augmented by it's size, in the following 4551format: "<initrd addres>:<initrd size>". 4552 4553 4554Standalone HOWTO: 4555================= 4556 4557One of the features of U-Boot is that you can dynamically load and 4558run "standalone" applications, which can use some resources of 4559U-Boot like console I/O functions or interrupt services. 4560 4561Two simple examples are included with the sources: 4562 4563"Hello World" Demo: 4564------------------- 4565 4566'examples/hello_world.c' contains a small "Hello World" Demo 4567application; it is automatically compiled when you build U-Boot. 4568It's configured to run at address 0x00040004, so you can play with it 4569like that: 4570 4571 => loads 4572 ## Ready for S-Record download ... 4573 ~>examples/hello_world.srec 4574 1 2 3 4 5 6 7 8 9 10 11 ... 4575 [file transfer complete] 4576 [connected] 4577 ## Start Addr = 0x00040004 4578 4579 => go 40004 Hello World! This is a test. 4580 ## Starting application at 0x00040004 ... 4581 Hello World 4582 argc = 7 4583 argv[0] = "40004" 4584 argv[1] = "Hello" 4585 argv[2] = "World!" 4586 argv[3] = "This" 4587 argv[4] = "is" 4588 argv[5] = "a" 4589 argv[6] = "test." 4590 argv[7] = "<NULL>" 4591 Hit any key to exit ... 4592 4593 ## Application terminated, rc = 0x0 4594 4595Another example, which demonstrates how to register a CPM interrupt 4596handler with the U-Boot code, can be found in 'examples/timer.c'. 4597Here, a CPM timer is set up to generate an interrupt every second. 4598The interrupt service routine is trivial, just printing a '.' 4599character, but this is just a demo program. The application can be 4600controlled by the following keys: 4601 4602 ? - print current values og the CPM Timer registers 4603 b - enable interrupts and start timer 4604 e - stop timer and disable interrupts 4605 q - quit application 4606 4607 => loads 4608 ## Ready for S-Record download ... 4609 ~>examples/timer.srec 4610 1 2 3 4 5 6 7 8 9 10 11 ... 4611 [file transfer complete] 4612 [connected] 4613 ## Start Addr = 0x00040004 4614 4615 => go 40004 4616 ## Starting application at 0x00040004 ... 4617 TIMERS=0xfff00980 4618 Using timer 1 4619 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0 4620 4621Hit 'b': 4622 [q, b, e, ?] Set interval 1000000 us 4623 Enabling timer 4624Hit '?': 4625 [q, b, e, ?] ........ 4626 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0 4627Hit '?': 4628 [q, b, e, ?] . 4629 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0 4630Hit '?': 4631 [q, b, e, ?] . 4632 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0 4633Hit '?': 4634 [q, b, e, ?] . 4635 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0 4636Hit 'e': 4637 [q, b, e, ?] ...Stopping timer 4638Hit 'q': 4639 [q, b, e, ?] ## Application terminated, rc = 0x0 4640 4641 4642Minicom warning: 4643================ 4644 4645Over time, many people have reported problems when trying to use the 4646"minicom" terminal emulation program for serial download. I (wd) 4647consider minicom to be broken, and recommend not to use it. Under 4648Unix, I recommend to use C-Kermit for general purpose use (and 4649especially for kermit binary protocol download ("loadb" command), and 4650use "cu" for S-Record download ("loads" command). See 4651http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3. 4652for help with kermit. 4653 4654 4655Nevertheless, if you absolutely want to use it try adding this 4656configuration to your "File transfer protocols" section: 4657 4658 Name Program Name U/D FullScr IO-Red. Multi 4659 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N 4660 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N 4661 4662 4663NetBSD Notes: 4664============= 4665 4666Starting at version 0.9.2, U-Boot supports NetBSD both as host 4667(build U-Boot) and target system (boots NetBSD/mpc8xx). 4668 4669Building requires a cross environment; it is known to work on 4670NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also 4671need gmake since the Makefiles are not compatible with BSD make). 4672Note that the cross-powerpc package does not install include files; 4673attempting to build U-Boot will fail because <machine/ansi.h> is 4674missing. This file has to be installed and patched manually: 4675 4676 # cd /usr/pkg/cross/powerpc-netbsd/include 4677 # mkdir powerpc 4678 # ln -s powerpc machine 4679 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h 4680 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST 4681 4682Native builds *don't* work due to incompatibilities between native 4683and U-Boot include files. 4684 4685Booting assumes that (the first part of) the image booted is a 4686stage-2 loader which in turn loads and then invokes the kernel 4687proper. Loader sources will eventually appear in the NetBSD source 4688tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the 4689meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz 4690 4691 4692Implementation Internals: 4693========================= 4694 4695The following is not intended to be a complete description of every 4696implementation detail. However, it should help to understand the 4697inner workings of U-Boot and make it easier to port it to custom 4698hardware. 4699 4700 4701Initial Stack, Global Data: 4702--------------------------- 4703 4704The implementation of U-Boot is complicated by the fact that U-Boot 4705starts running out of ROM (flash memory), usually without access to 4706system RAM (because the memory controller is not initialized yet). 4707This means that we don't have writable Data or BSS segments, and BSS 4708is not initialized as zero. To be able to get a C environment working 4709at all, we have to allocate at least a minimal stack. Implementation 4710options for this are defined and restricted by the CPU used: Some CPU 4711models provide on-chip memory (like the IMMR area on MPC8xx and 4712MPC826x processors), on others (parts of) the data cache can be 4713locked as (mis-) used as memory, etc. 4714 4715 Chris Hallinan posted a good summary of these issues to the 4716 U-Boot mailing list: 4717 4718 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)? 4719 From: "Chris Hallinan" <clh@net1plus.com> 4720 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET) 4721 ... 4722 4723 Correct me if I'm wrong, folks, but the way I understand it 4724 is this: Using DCACHE as initial RAM for Stack, etc, does not 4725 require any physical RAM backing up the cache. The cleverness 4726 is that the cache is being used as a temporary supply of 4727 necessary storage before the SDRAM controller is setup. It's 4728 beyond the scope of this list to explain the details, but you 4729 can see how this works by studying the cache architecture and 4730 operation in the architecture and processor-specific manuals. 4731 4732 OCM is On Chip Memory, which I believe the 405GP has 4K. It 4733 is another option for the system designer to use as an 4734 initial stack/RAM area prior to SDRAM being available. Either 4735 option should work for you. Using CS 4 should be fine if your 4736 board designers haven't used it for something that would 4737 cause you grief during the initial boot! It is frequently not 4738 used. 4739 4740 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere 4741 with your processor/board/system design. The default value 4742 you will find in any recent u-boot distribution in 4743 walnut.h should work for you. I'd set it to a value larger 4744 than your SDRAM module. If you have a 64MB SDRAM module, set 4745 it above 400_0000. Just make sure your board has no resources 4746 that are supposed to respond to that address! That code in 4747 start.S has been around a while and should work as is when 4748 you get the config right. 4749 4750 -Chris Hallinan 4751 DS4.COM, Inc. 4752 4753It is essential to remember this, since it has some impact on the C 4754code for the initialization procedures: 4755 4756* Initialized global data (data segment) is read-only. Do not attempt 4757 to write it. 4758 4759* Do not use any uninitialized global data (or implicitly initialized 4760 as zero data - BSS segment) at all - this is undefined, initiali- 4761 zation is performed later (when relocating to RAM). 4762 4763* Stack space is very limited. Avoid big data buffers or things like 4764 that. 4765 4766Having only the stack as writable memory limits means we cannot use 4767normal global data to share information between the code. But it 4768turned out that the implementation of U-Boot can be greatly 4769simplified by making a global data structure (gd_t) available to all 4770functions. We could pass a pointer to this data as argument to _all_ 4771functions, but this would bloat the code. Instead we use a feature of 4772the GCC compiler (Global Register Variables) to share the data: we 4773place a pointer (gd) to the global data into a register which we 4774reserve for this purpose. 4775 4776When choosing a register for such a purpose we are restricted by the 4777relevant (E)ABI specifications for the current architecture, and by 4778GCC's implementation. 4779 4780For PowerPC, the following registers have specific use: 4781 R1: stack pointer 4782 R2: reserved for system use 4783 R3-R4: parameter passing and return values 4784 R5-R10: parameter passing 4785 R13: small data area pointer 4786 R30: GOT pointer 4787 R31: frame pointer 4788 4789 (U-Boot also uses R12 as internal GOT pointer. r12 4790 is a volatile register so r12 needs to be reset when 4791 going back and forth between asm and C) 4792 4793 ==> U-Boot will use R2 to hold a pointer to the global data 4794 4795 Note: on PPC, we could use a static initializer (since the 4796 address of the global data structure is known at compile time), 4797 but it turned out that reserving a register results in somewhat 4798 smaller code - although the code savings are not that big (on 4799 average for all boards 752 bytes for the whole U-Boot image, 4800 624 text + 127 data). 4801 4802On ARM, the following registers are used: 4803 4804 R0: function argument word/integer result 4805 R1-R3: function argument word 4806 R9: platform specific 4807 R10: stack limit (used only if stack checking is enabled) 4808 R11: argument (frame) pointer 4809 R12: temporary workspace 4810 R13: stack pointer 4811 R14: link register 4812 R15: program counter 4813 4814 ==> U-Boot will use R9 to hold a pointer to the global data 4815 4816 Note: on ARM, only R_ARM_RELATIVE relocations are supported. 4817 4818On Nios II, the ABI is documented here: 4819 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf 4820 4821 ==> U-Boot will use gp to hold a pointer to the global data 4822 4823 Note: on Nios II, we give "-G0" option to gcc and don't use gp 4824 to access small data sections, so gp is free. 4825 4826On NDS32, the following registers are used: 4827 4828 R0-R1: argument/return 4829 R2-R5: argument 4830 R15: temporary register for assembler 4831 R16: trampoline register 4832 R28: frame pointer (FP) 4833 R29: global pointer (GP) 4834 R30: link register (LP) 4835 R31: stack pointer (SP) 4836 PC: program counter (PC) 4837 4838 ==> U-Boot will use R10 to hold a pointer to the global data 4839 4840NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope, 4841or current versions of GCC may "optimize" the code too much. 4842 4843On RISC-V, the following registers are used: 4844 4845 x0: hard-wired zero (zero) 4846 x1: return address (ra) 4847 x2: stack pointer (sp) 4848 x3: global pointer (gp) 4849 x4: thread pointer (tp) 4850 x5: link register (t0) 4851 x8: frame pointer (fp) 4852 x10-x11: arguments/return values (a0-1) 4853 x12-x17: arguments (a2-7) 4854 x28-31: temporaries (t3-6) 4855 pc: program counter (pc) 4856 4857 ==> U-Boot will use gp to hold a pointer to the global data 4858 4859Memory Management: 4860------------------ 4861 4862U-Boot runs in system state and uses physical addresses, i.e. the 4863MMU is not used either for address mapping nor for memory protection. 4864 4865The available memory is mapped to fixed addresses using the memory 4866controller. In this process, a contiguous block is formed for each 4867memory type (Flash, SDRAM, SRAM), even when it consists of several 4868physical memory banks. 4869 4870U-Boot is installed in the first 128 kB of the first Flash bank (on 4871TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After 4872booting and sizing and initializing DRAM, the code relocates itself 4873to the upper end of DRAM. Immediately below the U-Boot code some 4874memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN 4875configuration setting]. Below that, a structure with global Board 4876Info data is placed, followed by the stack (growing downward). 4877 4878Additionally, some exception handler code is copied to the low 8 kB 4879of DRAM (0x00000000 ... 0x00001FFF). 4880 4881So a typical memory configuration with 16 MB of DRAM could look like 4882this: 4883 4884 0x0000 0000 Exception Vector code 4885 : 4886 0x0000 1FFF 4887 0x0000 2000 Free for Application Use 4888 : 4889 : 4890 4891 : 4892 : 4893 0x00FB FF20 Monitor Stack (Growing downward) 4894 0x00FB FFAC Board Info Data and permanent copy of global data 4895 0x00FC 0000 Malloc Arena 4896 : 4897 0x00FD FFFF 4898 0x00FE 0000 RAM Copy of Monitor Code 4899 ... eventually: LCD or video framebuffer 4900 ... eventually: pRAM (Protected RAM - unchanged by reset) 4901 0x00FF FFFF [End of RAM] 4902 4903 4904System Initialization: 4905---------------------- 4906 4907In the reset configuration, U-Boot starts at the reset entry point 4908(on most PowerPC systems at address 0x00000100). Because of the reset 4909configuration for CS0# this is a mirror of the on board Flash memory. 4910To be able to re-map memory U-Boot then jumps to its link address. 4911To be able to implement the initialization code in C, a (small!) 4912initial stack is set up in the internal Dual Ported RAM (in case CPUs 4913which provide such a feature like), or in a locked part of the data 4914cache. After that, U-Boot initializes the CPU core, the caches and 4915the SIU. 4916 4917Next, all (potentially) available memory banks are mapped using a 4918preliminary mapping. For example, we put them on 512 MB boundaries 4919(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash 4920on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is 4921programmed for SDRAM access. Using the temporary configuration, a 4922simple memory test is run that determines the size of the SDRAM 4923banks. 4924 4925When there is more than one SDRAM bank, and the banks are of 4926different size, the largest is mapped first. For equal size, the first 4927bank (CS2#) is mapped first. The first mapping is always for address 49280x00000000, with any additional banks following immediately to create 4929contiguous memory starting from 0. 4930 4931Then, the monitor installs itself at the upper end of the SDRAM area 4932and allocates memory for use by malloc() and for the global Board 4933Info data; also, the exception vector code is copied to the low RAM 4934pages, and the final stack is set up. 4935 4936Only after this relocation will you have a "normal" C environment; 4937until that you are restricted in several ways, mostly because you are 4938running from ROM, and because the code will have to be relocated to a 4939new address in RAM. 4940 4941 4942U-Boot Porting Guide: 4943---------------------- 4944 4945[Based on messages by Jerry Van Baren in the U-Boot-Users mailing 4946list, October 2002] 4947 4948 4949int main(int argc, char *argv[]) 4950{ 4951 sighandler_t no_more_time; 4952 4953 signal(SIGALRM, no_more_time); 4954 alarm(PROJECT_DEADLINE - toSec (3 * WEEK)); 4955 4956 if (available_money > available_manpower) { 4957 Pay consultant to port U-Boot; 4958 return 0; 4959 } 4960 4961 Download latest U-Boot source; 4962 4963 Subscribe to u-boot mailing list; 4964 4965 if (clueless) 4966 email("Hi, I am new to U-Boot, how do I get started?"); 4967 4968 while (learning) { 4969 Read the README file in the top level directory; 4970 Read http://www.denx.de/twiki/bin/view/DULG/Manual; 4971 Read applicable doc/*.README; 4972 Read the source, Luke; 4973 /* find . -name "*.[chS]" | xargs grep -i <keyword> */ 4974 } 4975 4976 if (available_money > toLocalCurrency ($2500)) 4977 Buy a BDI3000; 4978 else 4979 Add a lot of aggravation and time; 4980 4981 if (a similar board exists) { /* hopefully... */ 4982 cp -a board/<similar> board/<myboard> 4983 cp include/configs/<similar>.h include/configs/<myboard>.h 4984 } else { 4985 Create your own board support subdirectory; 4986 Create your own board include/configs/<myboard>.h file; 4987 } 4988 Edit new board/<myboard> files 4989 Edit new include/configs/<myboard>.h 4990 4991 while (!accepted) { 4992 while (!running) { 4993 do { 4994 Add / modify source code; 4995 } until (compiles); 4996 Debug; 4997 if (clueless) 4998 email("Hi, I am having problems..."); 4999 } 5000 Send patch file to the U-Boot email list; 5001 if (reasonable critiques) 5002 Incorporate improvements from email list code review; 5003 else 5004 Defend code as written; 5005 } 5006 5007 return 0; 5008} 5009 5010void no_more_time (int sig) 5011{ 5012 hire_a_guru(); 5013} 5014 5015 5016Coding Standards: 5017----------------- 5018 5019All contributions to U-Boot should conform to the Linux kernel 5020coding style; see the kernel coding style guide at 5021https://www.kernel.org/doc/html/latest/process/coding-style.html, and the 5022script "scripts/Lindent" in your Linux kernel source directory. 5023 5024Source files originating from a different project (for example the 5025MTD subsystem) are generally exempt from these guidelines and are not 5026reformatted to ease subsequent migration to newer versions of those 5027sources. 5028 5029Please note that U-Boot is implemented in C (and to some small parts in 5030Assembler); no C++ is used, so please do not use C++ style comments (//) 5031in your code. 5032 5033Please also stick to the following formatting rules: 5034- remove any trailing white space 5035- use TAB characters for indentation and vertical alignment, not spaces 5036- make sure NOT to use DOS '\r\n' line feeds 5037- do not add more than 2 consecutive empty lines to source files 5038- do not add trailing empty lines to source files 5039 5040Submissions which do not conform to the standards may be returned 5041with a request to reformat the changes. 5042 5043 5044Submitting Patches: 5045------------------- 5046 5047Since the number of patches for U-Boot is growing, we need to 5048establish some rules. Submissions which do not conform to these rules 5049may be rejected, even when they contain important and valuable stuff. 5050 5051Please see http://www.denx.de/wiki/U-Boot/Patches for details. 5052 5053Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>; 5054see https://lists.denx.de/listinfo/u-boot 5055 5056When you send a patch, please include the following information with 5057it: 5058 5059* For bug fixes: a description of the bug and how your patch fixes 5060 this bug. Please try to include a way of demonstrating that the 5061 patch actually fixes something. 5062 5063* For new features: a description of the feature and your 5064 implementation. 5065 5066* A CHANGELOG entry as plaintext (separate from the patch) 5067 5068* For major contributions, add a MAINTAINERS file with your 5069 information and associated file and directory references. 5070 5071* When you add support for a new board, don't forget to add a 5072 maintainer e-mail address to the boards.cfg file, too. 5073 5074* If your patch adds new configuration options, don't forget to 5075 document these in the README file. 5076 5077* The patch itself. If you are using git (which is *strongly* 5078 recommended) you can easily generate the patch using the 5079 "git format-patch". If you then use "git send-email" to send it to 5080 the U-Boot mailing list, you will avoid most of the common problems 5081 with some other mail clients. 5082 5083 If you cannot use git, use "diff -purN OLD NEW". If your version of 5084 diff does not support these options, then get the latest version of 5085 GNU diff. 5086 5087 The current directory when running this command shall be the parent 5088 directory of the U-Boot source tree (i. e. please make sure that 5089 your patch includes sufficient directory information for the 5090 affected files). 5091 5092 We prefer patches as plain text. MIME attachments are discouraged, 5093 and compressed attachments must not be used. 5094 5095* If one logical set of modifications affects or creates several 5096 files, all these changes shall be submitted in a SINGLE patch file. 5097 5098* Changesets that contain different, unrelated modifications shall be 5099 submitted as SEPARATE patches, one patch per changeset. 5100 5101 5102Notes: 5103 5104* Before sending the patch, run the buildman script on your patched 5105 source tree and make sure that no errors or warnings are reported 5106 for any of the boards. 5107 5108* Keep your modifications to the necessary minimum: A patch 5109 containing several unrelated changes or arbitrary reformats will be 5110 returned with a request to re-formatting / split it. 5111 5112* If you modify existing code, make sure that your new code does not 5113 add to the memory footprint of the code ;-) Small is beautiful! 5114 When adding new features, these should compile conditionally only 5115 (using #ifdef), and the resulting code with the new feature 5116 disabled must not need more memory than the old code without your 5117 modification. 5118 5119* Remember that there is a size limit of 100 kB per message on the 5120 u-boot mailing list. Bigger patches will be moderated. If they are 5121 reasonable and not too big, they will be acknowledged. But patches 5122 bigger than the size limit should be avoided. 5123