2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-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
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
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
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
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
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 candiate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /common Misc architecture independent functions
155 /configs Board default configuration files
156 /disk Code for disk drive partition handling
157 /doc Documentation (don't expect too much)
158 /drivers Commonly used device drivers
159 /dts Contains Makefile for building internal U-Boot fdt.
160 /examples Example code for standalone applications, etc.
161 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
162 /include Header Files
163 /lib Library routines generic to all architectures
164 /Licenses Various license files
166 /post Power On Self Test
167 /scripts Various build scripts and Makefiles
168 /test Various unit test files
169 /tools Tools to build S-Record or U-Boot images, etc.
171 Software Configuration:
172 =======================
174 Configuration is usually done using C preprocessor defines; the
175 rationale behind that is to avoid dead code whenever possible.
177 There are two classes of configuration variables:
179 * Configuration _OPTIONS_:
180 These are selectable by the user and have names beginning with
183 * Configuration _SETTINGS_:
184 These depend on the hardware etc. and should not be meddled with if
185 you don't know what you're doing; they have names beginning with
188 Previously, all configuration was done by hand, which involved creating
189 symbolic links and editing configuration files manually. More recently,
190 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
191 allowing you to use the "make menuconfig" command to configure your
195 Selection of Processor Architecture and Board Type:
196 ---------------------------------------------------
198 For all supported boards there are ready-to-use default
199 configurations available; just type "make <board_name>_defconfig".
201 Example: For a TQM823L module type:
204 make TQM823L_defconfig
206 Note: If you're looking for the default configuration file for a board
207 you're sure used to be there but is now missing, check the file
208 doc/README.scrapyard for a list of no longer supported boards.
213 U-Boot can be built natively to run on a Linux host using the 'sandbox'
214 board. This allows feature development which is not board- or architecture-
215 specific to be undertaken on a native platform. The sandbox is also used to
216 run some of U-Boot's tests.
218 See board/sandbox/README.sandbox for more details.
221 Board Initialisation Flow:
222 --------------------------
224 This is the intended start-up flow for boards. This should apply for both
225 SPL and U-Boot proper (i.e. they both follow the same rules).
227 Note: "SPL" stands for "Secondary Program Loader," which is explained in
228 more detail later in this file.
230 At present, SPL mostly uses a separate code path, but the function names
231 and roles of each function are the same. Some boards or architectures
232 may not conform to this. At least most ARM boards which use
233 CONFIG_SPL_FRAMEWORK conform to this.
235 Execution typically starts with an architecture-specific (and possibly
236 CPU-specific) start.S file, such as:
238 - arch/arm/cpu/armv7/start.S
239 - arch/powerpc/cpu/mpc83xx/start.S
240 - arch/mips/cpu/start.S
242 and so on. From there, three functions are called; the purpose and
243 limitations of each of these functions are described below.
246 - purpose: essential init to permit execution to reach board_init_f()
247 - no global_data or BSS
248 - there is no stack (ARMv7 may have one but it will soon be removed)
249 - must not set up SDRAM or use console
250 - must only do the bare minimum to allow execution to continue to
252 - this is almost never needed
253 - return normally from this function
256 - purpose: set up the machine ready for running board_init_r():
257 i.e. SDRAM and serial UART
258 - global_data is available
260 - BSS is not available, so you cannot use global/static variables,
261 only stack variables and global_data
263 Non-SPL-specific notes:
264 - dram_init() is called to set up DRAM. If already done in SPL this
268 - you can override the entire board_init_f() function with your own
270 - preloader_console_init() can be called here in extremis
271 - should set up SDRAM, and anything needed to make the UART work
272 - these is no need to clear BSS, it will be done by crt0.S
273 - must return normally from this function (don't call board_init_r()
276 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
277 this point the stack and global_data are relocated to below
278 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
282 - purpose: main execution, common code
283 - global_data is available
285 - BSS is available, all static/global variables can be used
286 - execution eventually continues to main_loop()
288 Non-SPL-specific notes:
289 - U-Boot is relocated to the top of memory and is now running from
293 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
294 CONFIG_SPL_STACK_R_ADDR points into SDRAM
295 - preloader_console_init() can be called here - typically this is
296 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
297 spl_board_init() function containing this call
298 - loads U-Boot or (in falcon mode) Linux
302 Configuration Options:
303 ----------------------
305 Configuration depends on the combination of board and CPU type; all
306 such information is kept in a configuration file
307 "include/configs/<board_name>.h".
309 Example: For a TQM823L module, all configuration settings are in
310 "include/configs/TQM823L.h".
313 Many of the options are named exactly as the corresponding Linux
314 kernel configuration options. The intention is to make it easier to
315 build a config tool - later.
318 The following options need to be configured:
320 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
322 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
324 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
325 Define exactly one, e.g. CONFIG_ATSTK1002
327 - CPU Module Type: (if CONFIG_COGENT is defined)
328 Define exactly one of
330 --- FIXME --- not tested yet:
331 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
332 CONFIG_CMA287_23, CONFIG_CMA287_50
334 - Motherboard Type: (if CONFIG_COGENT is defined)
335 Define exactly one of
336 CONFIG_CMA101, CONFIG_CMA102
338 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
339 Define one or more of
342 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
343 Define one or more of
344 CONFIG_LCD_HEARTBEAT - update a character position on
345 the LCD display every second with
348 - Marvell Family Member
349 CONFIG_SYS_MVFS - define it if you want to enable
350 multiple fs option at one time
351 for marvell soc family
353 - 8xx CPU Options: (if using an MPC8xx CPU)
354 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
355 get_gclk_freq() cannot work
356 e.g. if there is no 32KHz
357 reference PIT/RTC clock
358 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
361 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
362 CONFIG_SYS_8xx_CPUCLK_MIN
363 CONFIG_SYS_8xx_CPUCLK_MAX
364 CONFIG_8xx_CPUCLK_DEFAULT
365 See doc/README.MPC866
367 CONFIG_SYS_MEASURE_CPUCLK
369 Define this to measure the actual CPU clock instead
370 of relying on the correctness of the configured
371 values. Mostly useful for board bringup to make sure
372 the PLL is locked at the intended frequency. Note
373 that this requires a (stable) reference clock (32 kHz
374 RTC clock or CONFIG_SYS_8XX_XIN)
376 CONFIG_SYS_DELAYED_ICACHE
378 Define this option if you want to enable the
379 ICache only when Code runs from RAM.
384 Specifies that the core is a 64-bit PowerPC implementation (implements
385 the "64" category of the Power ISA). This is necessary for ePAPR
386 compliance, among other possible reasons.
388 CONFIG_SYS_FSL_TBCLK_DIV
390 Defines the core time base clock divider ratio compared to the
391 system clock. On most PQ3 devices this is 8, on newer QorIQ
392 devices it can be 16 or 32. The ratio varies from SoC to Soc.
394 CONFIG_SYS_FSL_PCIE_COMPAT
396 Defines the string to utilize when trying to match PCIe device
397 tree nodes for the given platform.
399 CONFIG_SYS_PPC_E500_DEBUG_TLB
401 Enables a temporary TLB entry to be used during boot to work
402 around limitations in e500v1 and e500v2 external debugger
403 support. This reduces the portions of the boot code where
404 breakpoints and single stepping do not work. The value of this
405 symbol should be set to the TLB1 entry to be used for this
408 CONFIG_SYS_FSL_ERRATUM_A004510
410 Enables a workaround for erratum A004510. If set,
411 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
414 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
415 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
417 Defines one or two SoC revisions (low 8 bits of SVR)
418 for which the A004510 workaround should be applied.
420 The rest of SVR is either not relevant to the decision
421 of whether the erratum is present (e.g. p2040 versus
422 p2041) or is implied by the build target, which controls
423 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
425 See Freescale App Note 4493 for more information about
428 CONFIG_A003399_NOR_WORKAROUND
429 Enables a workaround for IFC erratum A003399. It is only
430 required during NOR boot.
432 CONFIG_A008044_WORKAROUND
433 Enables a workaround for T1040/T1042 erratum A008044. It is only
434 required during NAND boot and valid for Rev 1.0 SoC revision
436 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
438 This is the value to write into CCSR offset 0x18600
439 according to the A004510 workaround.
441 CONFIG_SYS_FSL_DSP_DDR_ADDR
442 This value denotes start offset of DDR memory which is
443 connected exclusively to the DSP cores.
445 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
446 This value denotes start offset of M2 memory
447 which is directly connected to the DSP core.
449 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
450 This value denotes start offset of M3 memory which is directly
451 connected to the DSP core.
453 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
454 This value denotes start offset of DSP CCSR space.
456 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
457 Single Source Clock is clocking mode present in some of FSL SoC's.
458 In this mode, a single differential clock is used to supply
459 clocks to the sysclock, ddrclock and usbclock.
461 CONFIG_SYS_CPC_REINIT_F
462 This CONFIG is defined when the CPC is configured as SRAM at the
463 time of U-Boot entry and is required to be re-initialized.
466 Indicates this SoC supports deep sleep feature. If deep sleep is
467 supported, core will start to execute uboot when wakes up.
469 - Generic CPU options:
470 CONFIG_SYS_GENERIC_GLOBAL_DATA
471 Defines global data is initialized in generic board board_init_f().
472 If this macro is defined, global data is created and cleared in
473 generic board board_init_f(). Without this macro, architecture/board
474 should initialize global data before calling board_init_f().
476 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
478 Defines the endianess of the CPU. Implementation of those
479 values is arch specific.
482 Freescale DDR driver in use. This type of DDR controller is
483 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
486 CONFIG_SYS_FSL_DDR_ADDR
487 Freescale DDR memory-mapped register base.
489 CONFIG_SYS_FSL_DDR_EMU
490 Specify emulator support for DDR. Some DDR features such as
491 deskew training are not available.
493 CONFIG_SYS_FSL_DDRC_GEN1
494 Freescale DDR1 controller.
496 CONFIG_SYS_FSL_DDRC_GEN2
497 Freescale DDR2 controller.
499 CONFIG_SYS_FSL_DDRC_GEN3
500 Freescale DDR3 controller.
502 CONFIG_SYS_FSL_DDRC_GEN4
503 Freescale DDR4 controller.
505 CONFIG_SYS_FSL_DDRC_ARM_GEN3
506 Freescale DDR3 controller for ARM-based SoCs.
509 Board config to use DDR1. It can be enabled for SoCs with
510 Freescale DDR1 or DDR2 controllers, depending on the board
514 Board config to use DDR2. It can be enabled for SoCs with
515 Freescale DDR2 or DDR3 controllers, depending on the board
519 Board config to use DDR3. It can be enabled for SoCs with
520 Freescale DDR3 or DDR3L controllers.
523 Board config to use DDR3L. It can be enabled for SoCs with
527 Board config to use DDR4. It can be enabled for SoCs with
530 CONFIG_SYS_FSL_IFC_BE
531 Defines the IFC controller register space as Big Endian
533 CONFIG_SYS_FSL_IFC_LE
534 Defines the IFC controller register space as Little Endian
536 CONFIG_SYS_FSL_PBL_PBI
537 It enables addition of RCW (Power on reset configuration) in built image.
538 Please refer doc/README.pblimage for more details
540 CONFIG_SYS_FSL_PBL_RCW
541 It adds PBI(pre-boot instructions) commands in u-boot build image.
542 PBI commands can be used to configure SoC before it starts the execution.
543 Please refer doc/README.pblimage for more details
546 It adds a target to create boot binary having SPL binary in PBI format
547 concatenated with u-boot binary.
549 CONFIG_SYS_FSL_DDR_BE
550 Defines the DDR controller register space as Big Endian
552 CONFIG_SYS_FSL_DDR_LE
553 Defines the DDR controller register space as Little Endian
555 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
556 Physical address from the view of DDR controllers. It is the
557 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
558 it could be different for ARM SoCs.
560 CONFIG_SYS_FSL_DDR_INTLV_256B
561 DDR controller interleaving on 256-byte. This is a special
562 interleaving mode, handled by Dickens for Freescale layerscape
565 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
566 Number of controllers used as main memory.
568 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
569 Number of controllers used for other than main memory.
571 CONFIG_SYS_FSL_HAS_DP_DDR
572 Defines the SoC has DP-DDR used for DPAA.
574 CONFIG_SYS_FSL_SEC_BE
575 Defines the SEC controller register space as Big Endian
577 CONFIG_SYS_FSL_SEC_LE
578 Defines the SEC controller register space as Little Endian
580 - Intel Monahans options:
581 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
583 Defines the Monahans run mode to oscillator
584 ratio. Valid values are 8, 16, 24, 31. The core
585 frequency is this value multiplied by 13 MHz.
587 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
589 Defines the Monahans turbo mode to oscillator
590 ratio. Valid values are 1 (default if undefined) and
591 2. The core frequency as calculated above is multiplied
595 CONFIG_SYS_INIT_SP_OFFSET
597 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
598 pointer. This is needed for the temporary stack before
601 CONFIG_SYS_MIPS_CACHE_MODE
603 Cache operation mode for the MIPS CPU.
604 See also arch/mips/include/asm/mipsregs.h.
606 CONF_CM_CACHABLE_NO_WA
609 CONF_CM_CACHABLE_NONCOHERENT
613 CONF_CM_CACHABLE_ACCELERATED
615 CONFIG_SYS_XWAY_EBU_BOOTCFG
617 Special option for Lantiq XWAY SoCs for booting from NOR flash.
618 See also arch/mips/cpu/mips32/start.S.
620 CONFIG_XWAY_SWAP_BYTES
622 Enable compilation of tools/xway-swap-bytes needed for Lantiq
623 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
624 be swapped if a flash programmer is used.
627 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
629 Select high exception vectors of the ARM core, e.g., do not
630 clear the V bit of the c1 register of CP15.
632 CONFIG_SYS_THUMB_BUILD
634 Use this flag to build U-Boot using the Thumb instruction
635 set for ARM architectures. Thumb instruction set provides
636 better code density. For ARM architectures that support
637 Thumb2 this flag will result in Thumb2 code generated by
640 CONFIG_ARM_ERRATA_716044
641 CONFIG_ARM_ERRATA_742230
642 CONFIG_ARM_ERRATA_743622
643 CONFIG_ARM_ERRATA_751472
644 CONFIG_ARM_ERRATA_761320
645 CONFIG_ARM_ERRATA_773022
646 CONFIG_ARM_ERRATA_774769
647 CONFIG_ARM_ERRATA_794072
649 If set, the workarounds for these ARM errata are applied early
650 during U-Boot startup. Note that these options force the
651 workarounds to be applied; no CPU-type/version detection
652 exists, unlike the similar options in the Linux kernel. Do not
653 set these options unless they apply!
656 Generic timer clock source frequency.
658 COUNTER_FREQUENCY_REAL
659 Generic timer clock source frequency if the real clock is
660 different from COUNTER_FREQUENCY, and can only be determined
663 NOTE: The following can be machine specific errata. These
664 do have ability to provide rudimentary version and machine
665 specific checks, but expect no product checks.
666 CONFIG_ARM_ERRATA_430973
667 CONFIG_ARM_ERRATA_454179
668 CONFIG_ARM_ERRATA_621766
669 CONFIG_ARM_ERRATA_798870
670 CONFIG_ARM_ERRATA_801819
673 CONFIG_TEGRA_SUPPORT_NON_SECURE
675 Support executing U-Boot in non-secure (NS) mode. Certain
676 impossible actions will be skipped if the CPU is in NS mode,
677 such as ARM architectural timer initialization.
679 - Linux Kernel Interface:
682 U-Boot stores all clock information in Hz
683 internally. For binary compatibility with older Linux
684 kernels (which expect the clocks passed in the
685 bd_info data to be in MHz) the environment variable
686 "clocks_in_mhz" can be defined so that U-Boot
687 converts clock data to MHZ before passing it to the
689 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
690 "clocks_in_mhz=1" is automatically included in the
693 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
695 When transferring memsize parameter to Linux, some versions
696 expect it to be in bytes, others in MB.
697 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
701 New kernel versions are expecting firmware settings to be
702 passed using flattened device trees (based on open firmware
706 * New libfdt-based support
707 * Adds the "fdt" command
708 * The bootm command automatically updates the fdt
710 OF_CPU - The proper name of the cpus node (only required for
711 MPC512X and MPC5xxx based boards).
712 OF_SOC - The proper name of the soc node (only required for
713 MPC512X and MPC5xxx based boards).
714 OF_TBCLK - The timebase frequency.
715 OF_STDOUT_PATH - The path to the console device
717 boards with QUICC Engines require OF_QE to set UCC MAC
720 CONFIG_OF_BOARD_SETUP
722 Board code has addition modification that it wants to make
723 to the flat device tree before handing it off to the kernel
725 CONFIG_OF_SYSTEM_SETUP
727 Other code has addition modification that it wants to make
728 to the flat device tree before handing it off to the kernel.
729 This causes ft_system_setup() to be called before booting
734 This define fills in the correct boot CPU in the boot
735 param header, the default value is zero if undefined.
739 U-Boot can detect if an IDE device is present or not.
740 If not, and this new config option is activated, U-Boot
741 removes the ATA node from the DTS before booting Linux,
742 so the Linux IDE driver does not probe the device and
743 crash. This is needed for buggy hardware (uc101) where
744 no pull down resistor is connected to the signal IDE5V_DD7.
746 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
748 This setting is mandatory for all boards that have only one
749 machine type and must be used to specify the machine type
750 number as it appears in the ARM machine registry
751 (see http://www.arm.linux.org.uk/developer/machines/).
752 Only boards that have multiple machine types supported
753 in a single configuration file and the machine type is
754 runtime discoverable, do not have to use this setting.
756 - vxWorks boot parameters:
758 bootvx constructs a valid bootline using the following
759 environments variables: bootdev, bootfile, ipaddr, netmask,
760 serverip, gatewayip, hostname, othbootargs.
761 It loads the vxWorks image pointed bootfile.
763 Note: If a "bootargs" environment is defined, it will overwride
764 the defaults discussed just above.
766 - Cache Configuration:
767 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
768 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
769 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
771 - Cache Configuration for ARM:
772 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
774 CONFIG_SYS_PL310_BASE - Physical base address of PL310
775 controller register space
780 Define this if you want support for Amba PrimeCell PL010 UARTs.
784 Define this if you want support for Amba PrimeCell PL011 UARTs.
788 If you have Amba PrimeCell PL011 UARTs, set this variable to
789 the clock speed of the UARTs.
793 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
794 define this to a list of base addresses for each (supported)
795 port. See e.g. include/configs/versatile.h
797 CONFIG_SERIAL_HW_FLOW_CONTROL
799 Define this variable to enable hw flow control in serial driver.
800 Current user of this option is drivers/serial/nsl16550.c driver
803 Depending on board, define exactly one serial port
804 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
805 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
806 console by defining CONFIG_8xx_CONS_NONE
808 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
809 port routines must be defined elsewhere
810 (i.e. serial_init(), serial_getc(), ...)
813 Enables console device for a color framebuffer. Needs following
814 defines (cf. smiLynxEM, i8042)
815 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
817 VIDEO_HW_RECTFILL graphic chip supports
820 VIDEO_HW_BITBLT graphic chip supports
821 bit-blit (cf. smiLynxEM)
822 VIDEO_VISIBLE_COLS visible pixel columns
824 VIDEO_VISIBLE_ROWS visible pixel rows
825 VIDEO_PIXEL_SIZE bytes per pixel
826 VIDEO_DATA_FORMAT graphic data format
827 (0-5, cf. cfb_console.c)
828 VIDEO_FB_ADRS framebuffer address
829 VIDEO_KBD_INIT_FCT keyboard int fct
830 (i.e. rx51_kp_init())
831 VIDEO_TSTC_FCT test char fct
833 VIDEO_GETC_FCT get char fct
835 CONFIG_VIDEO_LOGO display Linux logo in
837 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
838 linux_logo.h for logo.
839 Requires CONFIG_VIDEO_LOGO
840 CONFIG_CONSOLE_EXTRA_INFO
841 additional board info beside
844 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
845 a limited number of ANSI escape sequences (cursor control,
846 erase functions and limited graphics rendition control).
848 When CONFIG_CFB_CONSOLE is defined, video console is
849 default i/o. Serial console can be forced with
850 environment 'console=serial'.
852 When CONFIG_SILENT_CONSOLE is defined, all console
853 messages (by U-Boot and Linux!) can be silenced with
854 the "silent" environment variable. See
855 doc/README.silent for more information.
857 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
859 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
863 CONFIG_BAUDRATE - in bps
864 Select one of the baudrates listed in
865 CONFIG_SYS_BAUDRATE_TABLE, see below.
866 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
868 - Console Rx buffer length
869 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
870 the maximum receive buffer length for the SMC.
871 This option is actual only for 82xx and 8xx possible.
872 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
873 must be defined, to setup the maximum idle timeout for
876 - Pre-Console Buffer:
877 Prior to the console being initialised (i.e. serial UART
878 initialised etc) all console output is silently discarded.
879 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
880 buffer any console messages prior to the console being
881 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
882 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
883 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
884 bytes are output before the console is initialised, the
885 earlier bytes are discarded.
887 Note that when printing the buffer a copy is made on the
888 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
890 'Sane' compilers will generate smaller code if
891 CONFIG_PRE_CON_BUF_SZ is a power of 2
895 Only needed when CONFIG_BOOTDELAY is enabled;
896 define a command string that is automatically executed
897 when no character is read on the console interface
898 within "Boot Delay" after reset.
901 This can be used to pass arguments to the bootm
902 command. The value of CONFIG_BOOTARGS goes into the
903 environment value "bootargs".
905 CONFIG_RAMBOOT and CONFIG_NFSBOOT
906 The value of these goes into the environment as
907 "ramboot" and "nfsboot" respectively, and can be used
908 as a convenience, when switching between booting from
912 CONFIG_BOOTCOUNT_LIMIT
913 Implements a mechanism for detecting a repeating reboot
915 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
918 If no softreset save registers are found on the hardware
919 "bootcount" is stored in the environment. To prevent a
920 saveenv on all reboots, the environment variable
921 "upgrade_available" is used. If "upgrade_available" is
922 0, "bootcount" is always 0, if "upgrade_available" is
923 1 "bootcount" is incremented in the environment.
924 So the Userspace Applikation must set the "upgrade_available"
925 and "bootcount" variable to 0, if a boot was successfully.
930 When this option is #defined, the existence of the
931 environment variable "preboot" will be checked
932 immediately before starting the CONFIG_BOOTDELAY
933 countdown and/or running the auto-boot command resp.
934 entering interactive mode.
936 This feature is especially useful when "preboot" is
937 automatically generated or modified. For an example
938 see the LWMON board specific code: here "preboot" is
939 modified when the user holds down a certain
940 combination of keys on the (special) keyboard when
943 - Serial Download Echo Mode:
945 If defined to 1, all characters received during a
946 serial download (using the "loads" command) are
947 echoed back. This might be needed by some terminal
948 emulations (like "cu"), but may as well just take
949 time on others. This setting #define's the initial
950 value of the "loads_echo" environment variable.
952 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
954 Select one of the baudrates listed in
955 CONFIG_SYS_BAUDRATE_TABLE, see below.
958 Monitor commands can be included or excluded
959 from the build by using the #include files
960 <config_cmd_all.h> and #undef'ing unwanted
961 commands, or adding #define's for wanted commands.
963 The default command configuration includes all commands
964 except those marked below with a "*".
966 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
967 CONFIG_CMD_ASKENV * ask for env variable
968 CONFIG_CMD_BDI bdinfo
969 CONFIG_CMD_BEDBUG * Include BedBug Debugger
970 CONFIG_CMD_BMP * BMP support
971 CONFIG_CMD_BSP * Board specific commands
972 CONFIG_CMD_BOOTD bootd
973 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
974 CONFIG_CMD_CACHE * icache, dcache
975 CONFIG_CMD_CLK * clock command support
976 CONFIG_CMD_CONSOLE coninfo
977 CONFIG_CMD_CRC32 * crc32
978 CONFIG_CMD_DATE * support for RTC, date/time...
979 CONFIG_CMD_DHCP * DHCP support
980 CONFIG_CMD_DIAG * Diagnostics
981 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
982 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
983 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
984 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
985 CONFIG_CMD_DTT * Digital Therm and Thermostat
986 CONFIG_CMD_ECHO echo arguments
987 CONFIG_CMD_EDITENV edit env variable
988 CONFIG_CMD_EEPROM * EEPROM read/write support
989 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
990 CONFIG_CMD_ELF * bootelf, bootvx
991 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
992 CONFIG_CMD_ENV_FLAGS * display details about env flags
993 CONFIG_CMD_ENV_EXISTS * check existence of env variable
994 CONFIG_CMD_EXPORTENV * export the environment
995 CONFIG_CMD_EXT2 * ext2 command support
996 CONFIG_CMD_EXT4 * ext4 command support
997 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
998 that work for multiple fs types
999 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1000 CONFIG_CMD_SAVEENV saveenv
1001 CONFIG_CMD_FDC * Floppy Disk Support
1002 CONFIG_CMD_FAT * FAT command support
1003 CONFIG_CMD_FLASH flinfo, erase, protect
1004 CONFIG_CMD_FPGA FPGA device initialization support
1005 CONFIG_CMD_FUSE * Device fuse support
1006 CONFIG_CMD_GETTIME * Get time since boot
1007 CONFIG_CMD_GO * the 'go' command (exec code)
1008 CONFIG_CMD_GREPENV * search environment
1009 CONFIG_CMD_HASH * calculate hash / digest
1010 CONFIG_CMD_I2C * I2C serial bus support
1011 CONFIG_CMD_IDE * IDE harddisk support
1012 CONFIG_CMD_IMI iminfo
1013 CONFIG_CMD_IMLS List all images found in NOR flash
1014 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1015 CONFIG_CMD_IMMAP * IMMR dump support
1016 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1017 CONFIG_CMD_IMPORTENV * import an environment
1018 CONFIG_CMD_INI * import data from an ini file into the env
1019 CONFIG_CMD_IRQ * irqinfo
1020 CONFIG_CMD_ITEST Integer/string test of 2 values
1021 CONFIG_CMD_JFFS2 * JFFS2 Support
1022 CONFIG_CMD_KGDB * kgdb
1023 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1024 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1026 CONFIG_CMD_LOADB loadb
1027 CONFIG_CMD_LOADS loads
1028 CONFIG_CMD_MD5SUM * print md5 message digest
1029 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1030 CONFIG_CMD_MEMINFO * Display detailed memory information
1031 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1033 CONFIG_CMD_MEMTEST * mtest
1034 CONFIG_CMD_MISC Misc functions like sleep etc
1035 CONFIG_CMD_MMC * MMC memory mapped support
1036 CONFIG_CMD_MII * MII utility commands
1037 CONFIG_CMD_MTDPARTS * MTD partition support
1038 CONFIG_CMD_NAND * NAND support
1039 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1040 CONFIG_CMD_NFS NFS support
1041 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1042 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1043 CONFIG_CMD_PCI * pciinfo
1044 CONFIG_CMD_PCMCIA * PCMCIA support
1045 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1047 CONFIG_CMD_PORTIO * Port I/O
1048 CONFIG_CMD_READ * Read raw data from partition
1049 CONFIG_CMD_REGINFO * Register dump
1050 CONFIG_CMD_RUN run command in env variable
1051 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1052 CONFIG_CMD_SAVES * save S record dump
1053 CONFIG_SCSI * SCSI Support
1054 CONFIG_CMD_SDRAM * print SDRAM configuration information
1055 (requires CONFIG_CMD_I2C)
1056 CONFIG_CMD_SETGETDCR Support for DCR Register access
1058 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1059 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1060 (requires CONFIG_CMD_MEMORY)
1061 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1062 CONFIG_CMD_SOURCE "source" command Support
1063 CONFIG_CMD_SPI * SPI serial bus support
1064 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1065 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1066 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1067 CONFIG_CMD_TIMER * access to the system tick timer
1068 CONFIG_CMD_USB * USB support
1069 CONFIG_CMD_CDP * Cisco Discover Protocol support
1070 CONFIG_CMD_MFSL * Microblaze FSL support
1071 CONFIG_CMD_XIMG Load part of Multi Image
1072 CONFIG_CMD_UUID * Generate random UUID or GUID string
1074 EXAMPLE: If you want all functions except of network
1075 support you can write:
1077 #include "config_cmd_all.h"
1078 #undef CONFIG_CMD_NET
1081 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1083 Note: Don't enable the "icache" and "dcache" commands
1084 (configuration option CONFIG_CMD_CACHE) unless you know
1085 what you (and your U-Boot users) are doing. Data
1086 cache cannot be enabled on systems like the 8xx or
1087 8260 (where accesses to the IMMR region must be
1088 uncached), and it cannot be disabled on all other
1089 systems where we (mis-) use the data cache to hold an
1090 initial stack and some data.
1093 XXX - this list needs to get updated!
1095 - Removal of commands
1096 If no commands are needed to boot, you can disable
1097 CONFIG_CMDLINE to remove them. In this case, the command line
1098 will not be available, and when U-Boot wants to execute the
1099 boot command (on start-up) it will call board_run_command()
1100 instead. This can reduce image size significantly for very
1101 simple boot procedures.
1103 - Regular expression support:
1105 If this variable is defined, U-Boot is linked against
1106 the SLRE (Super Light Regular Expression) library,
1107 which adds regex support to some commands, as for
1108 example "env grep" and "setexpr".
1112 If this variable is defined, U-Boot will use a device tree
1113 to configure its devices, instead of relying on statically
1114 compiled #defines in the board file. This option is
1115 experimental and only available on a few boards. The device
1116 tree is available in the global data as gd->fdt_blob.
1118 U-Boot needs to get its device tree from somewhere. This can
1119 be done using one of the two options below:
1122 If this variable is defined, U-Boot will embed a device tree
1123 binary in its image. This device tree file should be in the
1124 board directory and called <soc>-<board>.dts. The binary file
1125 is then picked up in board_init_f() and made available through
1126 the global data structure as gd->blob.
1129 If this variable is defined, U-Boot will build a device tree
1130 binary. It will be called u-boot.dtb. Architecture-specific
1131 code will locate it at run-time. Generally this works by:
1133 cat u-boot.bin u-boot.dtb >image.bin
1135 and in fact, U-Boot does this for you, creating a file called
1136 u-boot-dtb.bin which is useful in the common case. You can
1137 still use the individual files if you need something more
1142 If this variable is defined, it enables watchdog
1143 support for the SoC. There must be support in the SoC
1144 specific code for a watchdog. For the 8xx and 8260
1145 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1146 register. When supported for a specific SoC is
1147 available, then no further board specific code should
1148 be needed to use it.
1151 When using a watchdog circuitry external to the used
1152 SoC, then define this variable and provide board
1153 specific code for the "hw_watchdog_reset" function.
1155 CONFIG_AT91_HW_WDT_TIMEOUT
1156 specify the timeout in seconds. default 2 seconds.
1159 CONFIG_VERSION_VARIABLE
1160 If this variable is defined, an environment variable
1161 named "ver" is created by U-Boot showing the U-Boot
1162 version as printed by the "version" command.
1163 Any change to this variable will be reverted at the
1168 When CONFIG_CMD_DATE is selected, the type of the RTC
1169 has to be selected, too. Define exactly one of the
1172 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1173 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1174 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1175 CONFIG_RTC_MC146818 - use MC146818 RTC
1176 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1177 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1178 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1179 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1180 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1181 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1182 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1183 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1184 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1187 Note that if the RTC uses I2C, then the I2C interface
1188 must also be configured. See I2C Support, below.
1191 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1193 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1194 chip-ngpio pairs that tell the PCA953X driver the number of
1195 pins supported by a particular chip.
1197 Note that if the GPIO device uses I2C, then the I2C interface
1198 must also be configured. See I2C Support, below.
1201 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1202 accesses and can checksum them or write a list of them out
1203 to memory. See the 'iotrace' command for details. This is
1204 useful for testing device drivers since it can confirm that
1205 the driver behaves the same way before and after a code
1206 change. Currently this is supported on sandbox and arm. To
1207 add support for your architecture, add '#include <iotrace.h>'
1208 to the bottom of arch/<arch>/include/asm/io.h and test.
1210 Example output from the 'iotrace stats' command is below.
1211 Note that if the trace buffer is exhausted, the checksum will
1212 still continue to operate.
1215 Start: 10000000 (buffer start address)
1216 Size: 00010000 (buffer size)
1217 Offset: 00000120 (current buffer offset)
1218 Output: 10000120 (start + offset)
1219 Count: 00000018 (number of trace records)
1220 CRC32: 9526fb66 (CRC32 of all trace records)
1222 - Timestamp Support:
1224 When CONFIG_TIMESTAMP is selected, the timestamp
1225 (date and time) of an image is printed by image
1226 commands like bootm or iminfo. This option is
1227 automatically enabled when you select CONFIG_CMD_DATE .
1229 - Partition Labels (disklabels) Supported:
1230 Zero or more of the following:
1231 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1232 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1233 Intel architecture, USB sticks, etc.
1234 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1235 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1236 bootloader. Note 2TB partition limit; see
1238 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1240 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1241 CONFIG_SCSI) you must configure support for at
1242 least one non-MTD partition type as well.
1245 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1246 board configurations files but used nowhere!
1248 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1249 be performed by calling the function
1250 ide_set_reset(int reset)
1251 which has to be defined in a board specific file
1256 Set this to enable ATAPI support.
1261 Set this to enable support for disks larger than 137GB
1262 Also look at CONFIG_SYS_64BIT_LBA.
1263 Whithout these , LBA48 support uses 32bit variables and will 'only'
1264 support disks up to 2.1TB.
1266 CONFIG_SYS_64BIT_LBA:
1267 When enabled, makes the IDE subsystem use 64bit sector addresses.
1271 At the moment only there is only support for the
1272 SYM53C8XX SCSI controller; define
1273 CONFIG_SCSI_SYM53C8XX to enable it.
1275 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1276 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1277 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1278 maximum numbers of LUNs, SCSI ID's and target
1280 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1282 The environment variable 'scsidevs' is set to the number of
1283 SCSI devices found during the last scan.
1285 - NETWORK Support (PCI):
1287 Support for Intel 8254x/8257x gigabit chips.
1290 Utility code for direct access to the SPI bus on Intel 8257x.
1291 This does not do anything useful unless you set at least one
1292 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1294 CONFIG_E1000_SPI_GENERIC
1295 Allow generic access to the SPI bus on the Intel 8257x, for
1296 example with the "sspi" command.
1299 Management command for E1000 devices. When used on devices
1300 with SPI support you can reprogram the EEPROM from U-Boot.
1303 Support for Intel 82557/82559/82559ER chips.
1304 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1305 write routine for first time initialisation.
1308 Support for Digital 2114x chips.
1309 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1310 modem chip initialisation (KS8761/QS6611).
1313 Support for National dp83815 chips.
1316 Support for National dp8382[01] gigabit chips.
1318 - NETWORK Support (other):
1320 CONFIG_DRIVER_AT91EMAC
1321 Support for AT91RM9200 EMAC.
1324 Define this to use reduced MII inteface
1326 CONFIG_DRIVER_AT91EMAC_QUIET
1327 If this defined, the driver is quiet.
1328 The driver doen't show link status messages.
1330 CONFIG_CALXEDA_XGMAC
1331 Support for the Calxeda XGMAC device
1334 Support for SMSC's LAN91C96 chips.
1336 CONFIG_LAN91C96_BASE
1337 Define this to hold the physical address
1338 of the LAN91C96's I/O space
1340 CONFIG_LAN91C96_USE_32_BIT
1341 Define this to enable 32 bit addressing
1344 Support for SMSC's LAN91C111 chip
1346 CONFIG_SMC91111_BASE
1347 Define this to hold the physical address
1348 of the device (I/O space)
1350 CONFIG_SMC_USE_32_BIT
1351 Define this if data bus is 32 bits
1353 CONFIG_SMC_USE_IOFUNCS
1354 Define this to use i/o functions instead of macros
1355 (some hardware wont work with macros)
1357 CONFIG_DRIVER_TI_EMAC
1358 Support for davinci emac
1360 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1361 Define this if you have more then 3 PHYs.
1364 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1366 CONFIG_FTGMAC100_EGIGA
1367 Define this to use GE link update with gigabit PHY.
1368 Define this if FTGMAC100 is connected to gigabit PHY.
1369 If your system has 10/100 PHY only, it might not occur
1370 wrong behavior. Because PHY usually return timeout or
1371 useless data when polling gigabit status and gigabit
1372 control registers. This behavior won't affect the
1373 correctnessof 10/100 link speed update.
1376 Support for SMSC's LAN911x and LAN921x chips
1379 Define this to hold the physical address
1380 of the device (I/O space)
1382 CONFIG_SMC911X_32_BIT
1383 Define this if data bus is 32 bits
1385 CONFIG_SMC911X_16_BIT
1386 Define this if data bus is 16 bits. If your processor
1387 automatically converts one 32 bit word to two 16 bit
1388 words you may also try CONFIG_SMC911X_32_BIT.
1391 Support for Renesas on-chip Ethernet controller
1393 CONFIG_SH_ETHER_USE_PORT
1394 Define the number of ports to be used
1396 CONFIG_SH_ETHER_PHY_ADDR
1397 Define the ETH PHY's address
1399 CONFIG_SH_ETHER_CACHE_WRITEBACK
1400 If this option is set, the driver enables cache flush.
1404 Support for PWM modul on the imx6.
1408 Support TPM devices.
1410 CONFIG_TPM_TIS_INFINEON
1411 Support for Infineon i2c bus TPM devices. Only one device
1412 per system is supported at this time.
1414 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1415 Define the burst count bytes upper limit
1418 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1420 CONFIG_TPM_ST33ZP24_I2C
1421 Support for STMicroelectronics ST33ZP24 I2C devices.
1422 Requires TPM_ST33ZP24 and I2C.
1424 CONFIG_TPM_ST33ZP24_SPI
1425 Support for STMicroelectronics ST33ZP24 SPI devices.
1426 Requires TPM_ST33ZP24 and SPI.
1428 CONFIG_TPM_ATMEL_TWI
1429 Support for Atmel TWI TPM device. Requires I2C support.
1432 Support for generic parallel port TPM devices. Only one device
1433 per system is supported at this time.
1435 CONFIG_TPM_TIS_BASE_ADDRESS
1436 Base address where the generic TPM device is mapped
1437 to. Contemporary x86 systems usually map it at
1441 Add tpm monitor functions.
1442 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1443 provides monitor access to authorized functions.
1446 Define this to enable the TPM support library which provides
1447 functional interfaces to some TPM commands.
1448 Requires support for a TPM device.
1450 CONFIG_TPM_AUTH_SESSIONS
1451 Define this to enable authorized functions in the TPM library.
1452 Requires CONFIG_TPM and CONFIG_SHA1.
1455 At the moment only the UHCI host controller is
1456 supported (PIP405, MIP405, MPC5200); define
1457 CONFIG_USB_UHCI to enable it.
1458 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1459 and define CONFIG_USB_STORAGE to enable the USB
1462 Supported are USB Keyboards and USB Floppy drives
1464 MPC5200 USB requires additional defines:
1466 for 528 MHz Clock: 0x0001bbbb
1470 for differential drivers: 0x00001000
1471 for single ended drivers: 0x00005000
1472 for differential drivers on PSC3: 0x00000100
1473 for single ended drivers on PSC3: 0x00004100
1474 CONFIG_SYS_USB_EVENT_POLL
1475 May be defined to allow interrupt polling
1476 instead of using asynchronous interrupts
1478 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1479 txfilltuning field in the EHCI controller on reset.
1481 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1482 HW module registers.
1485 Define the below if you wish to use the USB console.
1486 Once firmware is rebuilt from a serial console issue the
1487 command "setenv stdin usbtty; setenv stdout usbtty" and
1488 attach your USB cable. The Unix command "dmesg" should print
1489 it has found a new device. The environment variable usbtty
1490 can be set to gserial or cdc_acm to enable your device to
1491 appear to a USB host as a Linux gserial device or a
1492 Common Device Class Abstract Control Model serial device.
1493 If you select usbtty = gserial you should be able to enumerate
1495 # modprobe usbserial vendor=0xVendorID product=0xProductID
1496 else if using cdc_acm, simply setting the environment
1497 variable usbtty to be cdc_acm should suffice. The following
1498 might be defined in YourBoardName.h
1501 Define this to build a UDC device
1504 Define this to have a tty type of device available to
1505 talk to the UDC device
1508 Define this to enable the high speed support for usb
1509 device and usbtty. If this feature is enabled, a routine
1510 int is_usbd_high_speed(void)
1511 also needs to be defined by the driver to dynamically poll
1512 whether the enumeration has succeded at high speed or full
1515 CONFIG_SYS_CONSOLE_IS_IN_ENV
1516 Define this if you want stdin, stdout &/or stderr to
1520 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1521 Derive USB clock from external clock "blah"
1522 - CONFIG_SYS_USB_EXTC_CLK 0x02
1524 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1525 Derive USB clock from brgclk
1526 - CONFIG_SYS_USB_BRG_CLK 0x04
1528 If you have a USB-IF assigned VendorID then you may wish to
1529 define your own vendor specific values either in BoardName.h
1530 or directly in usbd_vendor_info.h. If you don't define
1531 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1532 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1533 should pretend to be a Linux device to it's target host.
1535 CONFIG_USBD_MANUFACTURER
1536 Define this string as the name of your company for
1537 - CONFIG_USBD_MANUFACTURER "my company"
1539 CONFIG_USBD_PRODUCT_NAME
1540 Define this string as the name of your product
1541 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1543 CONFIG_USBD_VENDORID
1544 Define this as your assigned Vendor ID from the USB
1545 Implementors Forum. This *must* be a genuine Vendor ID
1546 to avoid polluting the USB namespace.
1547 - CONFIG_USBD_VENDORID 0xFFFF
1549 CONFIG_USBD_PRODUCTID
1550 Define this as the unique Product ID
1552 - CONFIG_USBD_PRODUCTID 0xFFFF
1554 - ULPI Layer Support:
1555 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1556 the generic ULPI layer. The generic layer accesses the ULPI PHY
1557 via the platform viewport, so you need both the genric layer and
1558 the viewport enabled. Currently only Chipidea/ARC based
1559 viewport is supported.
1560 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1561 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1562 If your ULPI phy needs a different reference clock than the
1563 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1564 the appropriate value in Hz.
1567 The MMC controller on the Intel PXA is supported. To
1568 enable this define CONFIG_MMC. The MMC can be
1569 accessed from the boot prompt by mapping the device
1570 to physical memory similar to flash. Command line is
1571 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1572 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1575 Support for Renesas on-chip MMCIF controller
1577 CONFIG_SH_MMCIF_ADDR
1578 Define the base address of MMCIF registers
1581 Define the clock frequency for MMCIF
1584 Enable the generic MMC driver
1586 CONFIG_SUPPORT_EMMC_BOOT
1587 Enable some additional features of the eMMC boot partitions.
1589 CONFIG_SUPPORT_EMMC_RPMB
1590 Enable the commands for reading, writing and programming the
1591 key for the Replay Protection Memory Block partition in eMMC.
1593 - USB Device Firmware Update (DFU) class support:
1594 CONFIG_USB_FUNCTION_DFU
1595 This enables the USB portion of the DFU USB class
1598 This enables the command "dfu" which is used to have
1599 U-Boot create a DFU class device via USB. This command
1600 requires that the "dfu_alt_info" environment variable be
1601 set and define the alt settings to expose to the host.
1604 This enables support for exposing (e)MMC devices via DFU.
1607 This enables support for exposing NAND devices via DFU.
1610 This enables support for exposing RAM via DFU.
1611 Note: DFU spec refer to non-volatile memory usage, but
1612 allow usages beyond the scope of spec - here RAM usage,
1613 one that would help mostly the developer.
1615 CONFIG_SYS_DFU_DATA_BUF_SIZE
1616 Dfu transfer uses a buffer before writing data to the
1617 raw storage device. Make the size (in bytes) of this buffer
1618 configurable. The size of this buffer is also configurable
1619 through the "dfu_bufsiz" environment variable.
1621 CONFIG_SYS_DFU_MAX_FILE_SIZE
1622 When updating files rather than the raw storage device,
1623 we use a static buffer to copy the file into and then write
1624 the buffer once we've been given the whole file. Define
1625 this to the maximum filesize (in bytes) for the buffer.
1626 Default is 4 MiB if undefined.
1628 DFU_DEFAULT_POLL_TIMEOUT
1629 Poll timeout [ms], is the timeout a device can send to the
1630 host. The host must wait for this timeout before sending
1631 a subsequent DFU_GET_STATUS request to the device.
1633 DFU_MANIFEST_POLL_TIMEOUT
1634 Poll timeout [ms], which the device sends to the host when
1635 entering dfuMANIFEST state. Host waits this timeout, before
1636 sending again an USB request to the device.
1638 - USB Device Android Fastboot support:
1639 CONFIG_USB_FUNCTION_FASTBOOT
1640 This enables the USB part of the fastboot gadget
1643 This enables the command "fastboot" which enables the Android
1644 fastboot mode for the platform's USB device. Fastboot is a USB
1645 protocol for downloading images, flashing and device control
1646 used on Android devices.
1647 See doc/README.android-fastboot for more information.
1649 CONFIG_ANDROID_BOOT_IMAGE
1650 This enables support for booting images which use the Android
1651 image format header.
1653 CONFIG_FASTBOOT_BUF_ADDR
1654 The fastboot protocol requires a large memory buffer for
1655 downloads. Define this to the starting RAM address to use for
1658 CONFIG_FASTBOOT_BUF_SIZE
1659 The fastboot protocol requires a large memory buffer for
1660 downloads. This buffer should be as large as possible for a
1661 platform. Define this to the size available RAM for fastboot.
1663 CONFIG_FASTBOOT_FLASH
1664 The fastboot protocol includes a "flash" command for writing
1665 the downloaded image to a non-volatile storage device. Define
1666 this to enable the "fastboot flash" command.
1668 CONFIG_FASTBOOT_FLASH_MMC_DEV
1669 The fastboot "flash" command requires additional information
1670 regarding the non-volatile storage device. Define this to
1671 the eMMC device that fastboot should use to store the image.
1673 CONFIG_FASTBOOT_GPT_NAME
1674 The fastboot "flash" command supports writing the downloaded
1675 image to the Protective MBR and the Primary GUID Partition
1676 Table. (Additionally, this downloaded image is post-processed
1677 to generate and write the Backup GUID Partition Table.)
1678 This occurs when the specified "partition name" on the
1679 "fastboot flash" command line matches this value.
1680 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1682 - Journaling Flash filesystem support:
1683 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1684 CONFIG_JFFS2_NAND_DEV
1685 Define these for a default partition on a NAND device
1687 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1688 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1689 Define these for a default partition on a NOR device
1691 CONFIG_SYS_JFFS_CUSTOM_PART
1692 Define this to create an own partition. You have to provide a
1693 function struct part_info* jffs2_part_info(int part_num)
1695 If you define only one JFFS2 partition you may also want to
1696 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1697 to disable the command chpart. This is the default when you
1698 have not defined a custom partition
1700 - FAT(File Allocation Table) filesystem write function support:
1703 Define this to enable support for saving memory data as a
1704 file in FAT formatted partition.
1706 This will also enable the command "fatwrite" enabling the
1707 user to write files to FAT.
1709 CBFS (Coreboot Filesystem) support
1712 Define this to enable support for reading from a Coreboot
1713 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1716 - FAT(File Allocation Table) filesystem cluster size:
1717 CONFIG_FS_FAT_MAX_CLUSTSIZE
1719 Define the max cluster size for fat operations else
1720 a default value of 65536 will be defined.
1723 See Kconfig help for available keyboard drivers.
1727 Define this to enable a custom keyboard support.
1728 This simply calls drv_keyboard_init() which must be
1729 defined in your board-specific files. This option is deprecated
1730 and is only used by novena. For new boards, use driver model
1736 Define this to enable video support (for output to
1739 CONFIG_VIDEO_CT69000
1741 Enable Chips & Technologies 69000 Video chip
1743 CONFIG_VIDEO_SMI_LYNXEM
1744 Enable Silicon Motion SMI 712/710/810 Video chip. The
1745 video output is selected via environment 'videoout'
1746 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1749 For the CT69000 and SMI_LYNXEM drivers, videomode is
1750 selected via environment 'videomode'. Two different ways
1752 - "videomode=num" 'num' is a standard LiLo mode numbers.
1753 Following standard modes are supported (* is default):
1755 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1756 -------------+---------------------------------------------
1757 8 bits | 0x301* 0x303 0x305 0x161 0x307
1758 15 bits | 0x310 0x313 0x316 0x162 0x319
1759 16 bits | 0x311 0x314 0x317 0x163 0x31A
1760 24 bits | 0x312 0x315 0x318 ? 0x31B
1761 -------------+---------------------------------------------
1762 (i.e. setenv videomode 317; saveenv; reset;)
1764 - "videomode=bootargs" all the video parameters are parsed
1765 from the bootargs. (See drivers/video/videomodes.c)
1768 CONFIG_VIDEO_SED13806
1769 Enable Epson SED13806 driver. This driver supports 8bpp
1770 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1771 or CONFIG_VIDEO_SED13806_16BPP
1774 Enable the Freescale DIU video driver. Reference boards for
1775 SOCs that have a DIU should define this macro to enable DIU
1776 support, and should also define these other macros:
1782 CONFIG_VIDEO_SW_CURSOR
1783 CONFIG_VGA_AS_SINGLE_DEVICE
1785 CONFIG_VIDEO_BMP_LOGO
1787 The DIU driver will look for the 'video-mode' environment
1788 variable, and if defined, enable the DIU as a console during
1789 boot. See the documentation file doc/README.video for a
1790 description of this variable.
1792 - LCD Support: CONFIG_LCD
1794 Define this to enable LCD support (for output to LCD
1795 display); also select one of the supported displays
1796 by defining one of these:
1800 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1802 CONFIG_NEC_NL6448AC33:
1804 NEC NL6448AC33-18. Active, color, single scan.
1806 CONFIG_NEC_NL6448BC20
1808 NEC NL6448BC20-08. 6.5", 640x480.
1809 Active, color, single scan.
1811 CONFIG_NEC_NL6448BC33_54
1813 NEC NL6448BC33-54. 10.4", 640x480.
1814 Active, color, single scan.
1818 Sharp 320x240. Active, color, single scan.
1819 It isn't 16x9, and I am not sure what it is.
1821 CONFIG_SHARP_LQ64D341
1823 Sharp LQ64D341 display, 640x480.
1824 Active, color, single scan.
1828 HLD1045 display, 640x480.
1829 Active, color, single scan.
1833 Optrex CBL50840-2 NF-FW 99 22 M5
1835 Hitachi LMG6912RPFC-00T
1839 320x240. Black & white.
1841 Normally display is black on white background; define
1842 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1844 CONFIG_LCD_ALIGNMENT
1846 Normally the LCD is page-aligned (typically 4KB). If this is
1847 defined then the LCD will be aligned to this value instead.
1848 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1849 here, since it is cheaper to change data cache settings on
1850 a per-section basis.
1852 CONFIG_CONSOLE_SCROLL_LINES
1854 When the console need to be scrolled, this is the number of
1855 lines to scroll by. It defaults to 1. Increasing this makes
1856 the console jump but can help speed up operation when scrolling
1861 Sometimes, for example if the display is mounted in portrait
1862 mode or even if it's mounted landscape but rotated by 180degree,
1863 we need to rotate our content of the display relative to the
1864 framebuffer, so that user can read the messages which are
1866 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1867 initialized with a given rotation from "vl_rot" out of
1868 "vidinfo_t" which is provided by the board specific code.
1869 The value for vl_rot is coded as following (matching to
1870 fbcon=rotate:<n> linux-kernel commandline):
1871 0 = no rotation respectively 0 degree
1872 1 = 90 degree rotation
1873 2 = 180 degree rotation
1874 3 = 270 degree rotation
1876 If CONFIG_LCD_ROTATION is not defined, the console will be
1877 initialized with 0degree rotation.
1881 Support drawing of RLE8-compressed bitmaps on the LCD.
1885 Enables an 'i2c edid' command which can read EDID
1886 information over I2C from an attached LCD display.
1888 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1890 If this option is set, the environment is checked for
1891 a variable "splashimage". If found, the usual display
1892 of logo, copyright and system information on the LCD
1893 is suppressed and the BMP image at the address
1894 specified in "splashimage" is loaded instead. The
1895 console is redirected to the "nulldev", too. This
1896 allows for a "silent" boot where a splash screen is
1897 loaded very quickly after power-on.
1899 CONFIG_SPLASHIMAGE_GUARD
1901 If this option is set, then U-Boot will prevent the environment
1902 variable "splashimage" from being set to a problematic address
1903 (see doc/README.displaying-bmps).
1904 This option is useful for targets where, due to alignment
1905 restrictions, an improperly aligned BMP image will cause a data
1906 abort. If you think you will not have problems with unaligned
1907 accesses (for example because your toolchain prevents them)
1908 there is no need to set this option.
1910 CONFIG_SPLASH_SCREEN_ALIGN
1912 If this option is set the splash image can be freely positioned
1913 on the screen. Environment variable "splashpos" specifies the
1914 position as "x,y". If a positive number is given it is used as
1915 number of pixel from left/top. If a negative number is given it
1916 is used as number of pixel from right/bottom. You can also
1917 specify 'm' for centering the image.
1920 setenv splashpos m,m
1921 => image at center of screen
1923 setenv splashpos 30,20
1924 => image at x = 30 and y = 20
1926 setenv splashpos -10,m
1927 => vertically centered image
1928 at x = dspWidth - bmpWidth - 9
1930 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1932 If this option is set, additionally to standard BMP
1933 images, gzipped BMP images can be displayed via the
1934 splashscreen support or the bmp command.
1936 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1938 If this option is set, 8-bit RLE compressed BMP images
1939 can be displayed via the splashscreen support or the
1942 - Do compressing for memory range:
1945 If this option is set, it would use zlib deflate method
1946 to compress the specified memory at its best effort.
1948 - Compression support:
1951 Enabled by default to support gzip compressed images.
1955 If this option is set, support for bzip2 compressed
1956 images is included. If not, only uncompressed and gzip
1957 compressed images are supported.
1959 NOTE: the bzip2 algorithm requires a lot of RAM, so
1960 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1965 If this option is set, support for lzma compressed
1968 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1969 requires an amount of dynamic memory that is given by the
1972 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1974 Where lc and lp stand for, respectively, Literal context bits
1975 and Literal pos bits.
1977 This value is upper-bounded by 14MB in the worst case. Anyway,
1978 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1979 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1980 a very small buffer.
1982 Use the lzmainfo tool to determinate the lc and lp values and
1983 then calculate the amount of needed dynamic memory (ensuring
1984 the appropriate CONFIG_SYS_MALLOC_LEN value).
1988 If this option is set, support for LZO compressed images
1994 The address of PHY on MII bus.
1996 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1998 The clock frequency of the MII bus
2002 If this option is set, support for speed/duplex
2003 detection of gigabit PHY is included.
2005 CONFIG_PHY_RESET_DELAY
2007 Some PHY like Intel LXT971A need extra delay after
2008 reset before any MII register access is possible.
2009 For such PHY, set this option to the usec delay
2010 required. (minimum 300usec for LXT971A)
2012 CONFIG_PHY_CMD_DELAY (ppc4xx)
2014 Some PHY like Intel LXT971A need extra delay after
2015 command issued before MII status register can be read
2020 Define a default value for the IP address to use for
2021 the default Ethernet interface, in case this is not
2022 determined through e.g. bootp.
2023 (Environment variable "ipaddr")
2025 - Server IP address:
2028 Defines a default value for the IP address of a TFTP
2029 server to contact when using the "tftboot" command.
2030 (Environment variable "serverip")
2032 CONFIG_KEEP_SERVERADDR
2034 Keeps the server's MAC address, in the env 'serveraddr'
2035 for passing to bootargs (like Linux's netconsole option)
2037 - Gateway IP address:
2040 Defines a default value for the IP address of the
2041 default router where packets to other networks are
2043 (Environment variable "gatewayip")
2048 Defines a default value for the subnet mask (or
2049 routing prefix) which is used to determine if an IP
2050 address belongs to the local subnet or needs to be
2051 forwarded through a router.
2052 (Environment variable "netmask")
2054 - Multicast TFTP Mode:
2057 Defines whether you want to support multicast TFTP as per
2058 rfc-2090; for example to work with atftp. Lets lots of targets
2059 tftp down the same boot image concurrently. Note: the Ethernet
2060 driver in use must provide a function: mcast() to join/leave a
2063 - BOOTP Recovery Mode:
2064 CONFIG_BOOTP_RANDOM_DELAY
2066 If you have many targets in a network that try to
2067 boot using BOOTP, you may want to avoid that all
2068 systems send out BOOTP requests at precisely the same
2069 moment (which would happen for instance at recovery
2070 from a power failure, when all systems will try to
2071 boot, thus flooding the BOOTP server. Defining
2072 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2073 inserted before sending out BOOTP requests. The
2074 following delays are inserted then:
2076 1st BOOTP request: delay 0 ... 1 sec
2077 2nd BOOTP request: delay 0 ... 2 sec
2078 3rd BOOTP request: delay 0 ... 4 sec
2080 BOOTP requests: delay 0 ... 8 sec
2082 CONFIG_BOOTP_ID_CACHE_SIZE
2084 BOOTP packets are uniquely identified using a 32-bit ID. The
2085 server will copy the ID from client requests to responses and
2086 U-Boot will use this to determine if it is the destination of
2087 an incoming response. Some servers will check that addresses
2088 aren't in use before handing them out (usually using an ARP
2089 ping) and therefore take up to a few hundred milliseconds to
2090 respond. Network congestion may also influence the time it
2091 takes for a response to make it back to the client. If that
2092 time is too long, U-Boot will retransmit requests. In order
2093 to allow earlier responses to still be accepted after these
2094 retransmissions, U-Boot's BOOTP client keeps a small cache of
2095 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2096 cache. The default is to keep IDs for up to four outstanding
2097 requests. Increasing this will allow U-Boot to accept offers
2098 from a BOOTP client in networks with unusually high latency.
2100 - DHCP Advanced Options:
2101 You can fine tune the DHCP functionality by defining
2102 CONFIG_BOOTP_* symbols:
2104 CONFIG_BOOTP_SUBNETMASK
2105 CONFIG_BOOTP_GATEWAY
2106 CONFIG_BOOTP_HOSTNAME
2107 CONFIG_BOOTP_NISDOMAIN
2108 CONFIG_BOOTP_BOOTPATH
2109 CONFIG_BOOTP_BOOTFILESIZE
2112 CONFIG_BOOTP_SEND_HOSTNAME
2113 CONFIG_BOOTP_NTPSERVER
2114 CONFIG_BOOTP_TIMEOFFSET
2115 CONFIG_BOOTP_VENDOREX
2116 CONFIG_BOOTP_MAY_FAIL
2118 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2119 environment variable, not the BOOTP server.
2121 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2122 after the configured retry count, the call will fail
2123 instead of starting over. This can be used to fail over
2124 to Link-local IP address configuration if the DHCP server
2127 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2128 serverip from a DHCP server, it is possible that more
2129 than one DNS serverip is offered to the client.
2130 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2131 serverip will be stored in the additional environment
2132 variable "dnsip2". The first DNS serverip is always
2133 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2136 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2137 to do a dynamic update of a DNS server. To do this, they
2138 need the hostname of the DHCP requester.
2139 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2140 of the "hostname" environment variable is passed as
2141 option 12 to the DHCP server.
2143 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2145 A 32bit value in microseconds for a delay between
2146 receiving a "DHCP Offer" and sending the "DHCP Request".
2147 This fixes a problem with certain DHCP servers that don't
2148 respond 100% of the time to a "DHCP request". E.g. On an
2149 AT91RM9200 processor running at 180MHz, this delay needed
2150 to be *at least* 15,000 usec before a Windows Server 2003
2151 DHCP server would reply 100% of the time. I recommend at
2152 least 50,000 usec to be safe. The alternative is to hope
2153 that one of the retries will be successful but note that
2154 the DHCP timeout and retry process takes a longer than
2157 - Link-local IP address negotiation:
2158 Negotiate with other link-local clients on the local network
2159 for an address that doesn't require explicit configuration.
2160 This is especially useful if a DHCP server cannot be guaranteed
2161 to exist in all environments that the device must operate.
2163 See doc/README.link-local for more information.
2166 CONFIG_CDP_DEVICE_ID
2168 The device id used in CDP trigger frames.
2170 CONFIG_CDP_DEVICE_ID_PREFIX
2172 A two character string which is prefixed to the MAC address
2177 A printf format string which contains the ascii name of
2178 the port. Normally is set to "eth%d" which sets
2179 eth0 for the first Ethernet, eth1 for the second etc.
2181 CONFIG_CDP_CAPABILITIES
2183 A 32bit integer which indicates the device capabilities;
2184 0x00000010 for a normal host which does not forwards.
2188 An ascii string containing the version of the software.
2192 An ascii string containing the name of the platform.
2196 A 32bit integer sent on the trigger.
2198 CONFIG_CDP_POWER_CONSUMPTION
2200 A 16bit integer containing the power consumption of the
2201 device in .1 of milliwatts.
2203 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2205 A byte containing the id of the VLAN.
2207 - Status LED: CONFIG_STATUS_LED
2209 Several configurations allow to display the current
2210 status using a LED. For instance, the LED will blink
2211 fast while running U-Boot code, stop blinking as
2212 soon as a reply to a BOOTP request was received, and
2213 start blinking slow once the Linux kernel is running
2214 (supported by a status LED driver in the Linux
2215 kernel). Defining CONFIG_STATUS_LED enables this
2221 The status LED can be connected to a GPIO pin.
2222 In such cases, the gpio_led driver can be used as a
2223 status LED backend implementation. Define CONFIG_GPIO_LED
2224 to include the gpio_led driver in the U-Boot binary.
2226 CONFIG_GPIO_LED_INVERTED_TABLE
2227 Some GPIO connected LEDs may have inverted polarity in which
2228 case the GPIO high value corresponds to LED off state and
2229 GPIO low value corresponds to LED on state.
2230 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2231 with a list of GPIO LEDs that have inverted polarity.
2233 - CAN Support: CONFIG_CAN_DRIVER
2235 Defining CONFIG_CAN_DRIVER enables CAN driver support
2236 on those systems that support this (optional)
2237 feature, like the TQM8xxL modules.
2239 - I2C Support: CONFIG_SYS_I2C
2241 This enable the NEW i2c subsystem, and will allow you to use
2242 i2c commands at the u-boot command line (as long as you set
2243 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2244 based realtime clock chips or other i2c devices. See
2245 common/cmd_i2c.c for a description of the command line
2248 ported i2c driver to the new framework:
2249 - drivers/i2c/soft_i2c.c:
2250 - activate first bus with CONFIG_SYS_I2C_SOFT define
2251 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2252 for defining speed and slave address
2253 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2254 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2255 for defining speed and slave address
2256 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2257 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2258 for defining speed and slave address
2259 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2260 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2261 for defining speed and slave address
2263 - drivers/i2c/fsl_i2c.c:
2264 - activate i2c driver with CONFIG_SYS_I2C_FSL
2265 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2266 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2267 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2269 - If your board supports a second fsl i2c bus, define
2270 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2271 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2272 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2275 - drivers/i2c/tegra_i2c.c:
2276 - activate this driver with CONFIG_SYS_I2C_TEGRA
2277 - This driver adds 4 i2c buses with a fix speed from
2278 100000 and the slave addr 0!
2280 - drivers/i2c/ppc4xx_i2c.c
2281 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2282 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2283 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2285 - drivers/i2c/i2c_mxc.c
2286 - activate this driver with CONFIG_SYS_I2C_MXC
2287 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2288 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2289 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2290 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2291 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2292 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2293 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2294 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2295 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2296 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2297 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2298 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2299 If those defines are not set, default value is 100000
2300 for speed, and 0 for slave.
2302 - drivers/i2c/rcar_i2c.c:
2303 - activate this driver with CONFIG_SYS_I2C_RCAR
2304 - This driver adds 4 i2c buses
2306 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2307 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2308 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2309 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2310 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2311 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2312 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2313 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2314 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2316 - drivers/i2c/sh_i2c.c:
2317 - activate this driver with CONFIG_SYS_I2C_SH
2318 - This driver adds from 2 to 5 i2c buses
2320 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2321 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2322 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2323 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2324 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2325 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2326 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2327 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2328 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2329 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2330 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2331 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2332 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2334 - drivers/i2c/omap24xx_i2c.c
2335 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2336 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2337 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2338 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2339 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2340 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2341 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2342 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2343 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2344 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2345 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2347 - drivers/i2c/zynq_i2c.c
2348 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2349 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2350 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2352 - drivers/i2c/s3c24x0_i2c.c:
2353 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2354 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2355 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2356 with a fix speed from 100000 and the slave addr 0!
2358 - drivers/i2c/ihs_i2c.c
2359 - activate this driver with CONFIG_SYS_I2C_IHS
2360 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2361 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2362 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2363 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2364 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2365 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2366 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2367 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2368 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2369 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2370 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2371 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2372 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2373 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2374 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2375 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2376 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2377 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2378 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2379 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2380 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2384 CONFIG_SYS_NUM_I2C_BUSES
2385 Hold the number of i2c buses you want to use. If you
2386 don't use/have i2c muxes on your i2c bus, this
2387 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2390 CONFIG_SYS_I2C_DIRECT_BUS
2391 define this, if you don't use i2c muxes on your hardware.
2392 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2395 CONFIG_SYS_I2C_MAX_HOPS
2396 define how many muxes are maximal consecutively connected
2397 on one i2c bus. If you not use i2c muxes, omit this
2400 CONFIG_SYS_I2C_BUSES
2401 hold a list of buses you want to use, only used if
2402 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2403 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2404 CONFIG_SYS_NUM_I2C_BUSES = 9:
2406 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2407 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2408 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2409 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2410 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2411 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2412 {1, {I2C_NULL_HOP}}, \
2413 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2414 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2418 bus 0 on adapter 0 without a mux
2419 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2420 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2421 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2422 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2423 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2424 bus 6 on adapter 1 without a mux
2425 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2426 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2428 If you do not have i2c muxes on your board, omit this define.
2430 - Legacy I2C Support: CONFIG_HARD_I2C
2432 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2433 provides the following compelling advantages:
2435 - more than one i2c adapter is usable
2436 - approved multibus support
2437 - better i2c mux support
2439 ** Please consider updating your I2C driver now. **
2441 These enable legacy I2C serial bus commands. Defining
2442 CONFIG_HARD_I2C will include the appropriate I2C driver
2443 for the selected CPU.
2445 This will allow you to use i2c commands at the u-boot
2446 command line (as long as you set CONFIG_CMD_I2C in
2447 CONFIG_COMMANDS) and communicate with i2c based realtime
2448 clock chips. See common/cmd_i2c.c for a description of the
2449 command line interface.
2451 CONFIG_HARD_I2C selects a hardware I2C controller.
2453 There are several other quantities that must also be
2454 defined when you define CONFIG_HARD_I2C.
2456 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2457 to be the frequency (in Hz) at which you wish your i2c bus
2458 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2459 the CPU's i2c node address).
2461 Now, the u-boot i2c code for the mpc8xx
2462 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2463 and so its address should therefore be cleared to 0 (See,
2464 eg, MPC823e User's Manual p.16-473). So, set
2465 CONFIG_SYS_I2C_SLAVE to 0.
2467 CONFIG_SYS_I2C_INIT_MPC5XXX
2469 When a board is reset during an i2c bus transfer
2470 chips might think that the current transfer is still
2471 in progress. Reset the slave devices by sending start
2472 commands until the slave device responds.
2474 That's all that's required for CONFIG_HARD_I2C.
2476 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2477 then the following macros need to be defined (examples are
2478 from include/configs/lwmon.h):
2482 (Optional). Any commands necessary to enable the I2C
2483 controller or configure ports.
2485 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2489 (Only for MPC8260 CPU). The I/O port to use (the code
2490 assumes both bits are on the same port). Valid values
2491 are 0..3 for ports A..D.
2495 The code necessary to make the I2C data line active
2496 (driven). If the data line is open collector, this
2499 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2503 The code necessary to make the I2C data line tri-stated
2504 (inactive). If the data line is open collector, this
2507 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2511 Code that returns true if the I2C data line is high,
2514 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2518 If <bit> is true, sets the I2C data line high. If it
2519 is false, it clears it (low).
2521 eg: #define I2C_SDA(bit) \
2522 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2523 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2527 If <bit> is true, sets the I2C clock line high. If it
2528 is false, it clears it (low).
2530 eg: #define I2C_SCL(bit) \
2531 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2532 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2536 This delay is invoked four times per clock cycle so this
2537 controls the rate of data transfer. The data rate thus
2538 is 1 / (I2C_DELAY * 4). Often defined to be something
2541 #define I2C_DELAY udelay(2)
2543 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2545 If your arch supports the generic GPIO framework (asm/gpio.h),
2546 then you may alternatively define the two GPIOs that are to be
2547 used as SCL / SDA. Any of the previous I2C_xxx macros will
2548 have GPIO-based defaults assigned to them as appropriate.
2550 You should define these to the GPIO value as given directly to
2551 the generic GPIO functions.
2553 CONFIG_SYS_I2C_INIT_BOARD
2555 When a board is reset during an i2c bus transfer
2556 chips might think that the current transfer is still
2557 in progress. On some boards it is possible to access
2558 the i2c SCLK line directly, either by using the
2559 processor pin as a GPIO or by having a second pin
2560 connected to the bus. If this option is defined a
2561 custom i2c_init_board() routine in boards/xxx/board.c
2562 is run early in the boot sequence.
2564 CONFIG_SYS_I2C_BOARD_LATE_INIT
2566 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2567 defined a custom i2c_board_late_init() routine in
2568 boards/xxx/board.c is run AFTER the operations in i2c_init()
2569 is completed. This callpoint can be used to unreset i2c bus
2570 using CPU i2c controller register accesses for CPUs whose i2c
2571 controller provide such a method. It is called at the end of
2572 i2c_init() to allow i2c_init operations to setup the i2c bus
2573 controller on the CPU (e.g. setting bus speed & slave address).
2575 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2577 This option enables configuration of bi_iic_fast[] flags
2578 in u-boot bd_info structure based on u-boot environment
2579 variable "i2cfast". (see also i2cfast)
2581 CONFIG_I2C_MULTI_BUS
2583 This option allows the use of multiple I2C buses, each of which
2584 must have a controller. At any point in time, only one bus is
2585 active. To switch to a different bus, use the 'i2c dev' command.
2586 Note that bus numbering is zero-based.
2588 CONFIG_SYS_I2C_NOPROBES
2590 This option specifies a list of I2C devices that will be skipped
2591 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2592 is set, specify a list of bus-device pairs. Otherwise, specify
2593 a 1D array of device addresses
2596 #undef CONFIG_I2C_MULTI_BUS
2597 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2599 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2601 #define CONFIG_I2C_MULTI_BUS
2602 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2604 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2606 CONFIG_SYS_SPD_BUS_NUM
2608 If defined, then this indicates the I2C bus number for DDR SPD.
2609 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2611 CONFIG_SYS_RTC_BUS_NUM
2613 If defined, then this indicates the I2C bus number for the RTC.
2614 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2616 CONFIG_SYS_DTT_BUS_NUM
2618 If defined, then this indicates the I2C bus number for the DTT.
2619 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2621 CONFIG_SYS_I2C_DTT_ADDR:
2623 If defined, specifies the I2C address of the DTT device.
2624 If not defined, then U-Boot uses predefined value for
2625 specified DTT device.
2627 CONFIG_SOFT_I2C_READ_REPEATED_START
2629 defining this will force the i2c_read() function in
2630 the soft_i2c driver to perform an I2C repeated start
2631 between writing the address pointer and reading the
2632 data. If this define is omitted the default behaviour
2633 of doing a stop-start sequence will be used. Most I2C
2634 devices can use either method, but some require one or
2637 - SPI Support: CONFIG_SPI
2639 Enables SPI driver (so far only tested with
2640 SPI EEPROM, also an instance works with Crystal A/D and
2641 D/As on the SACSng board)
2645 Enables the driver for SPI controller on SuperH. Currently
2646 only SH7757 is supported.
2650 Enables a software (bit-bang) SPI driver rather than
2651 using hardware support. This is a general purpose
2652 driver that only requires three general I/O port pins
2653 (two outputs, one input) to function. If this is
2654 defined, the board configuration must define several
2655 SPI configuration items (port pins to use, etc). For
2656 an example, see include/configs/sacsng.h.
2660 Enables a hardware SPI driver for general-purpose reads
2661 and writes. As with CONFIG_SOFT_SPI, the board configuration
2662 must define a list of chip-select function pointers.
2663 Currently supported on some MPC8xxx processors. For an
2664 example, see include/configs/mpc8349emds.h.
2668 Enables the driver for the SPI controllers on i.MX and MXC
2669 SoCs. Currently i.MX31/35/51 are supported.
2671 CONFIG_SYS_SPI_MXC_WAIT
2672 Timeout for waiting until spi transfer completed.
2673 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2675 - FPGA Support: CONFIG_FPGA
2677 Enables FPGA subsystem.
2679 CONFIG_FPGA_<vendor>
2681 Enables support for specific chip vendors.
2684 CONFIG_FPGA_<family>
2686 Enables support for FPGA family.
2687 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2691 Specify the number of FPGA devices to support.
2693 CONFIG_CMD_FPGA_LOADMK
2695 Enable support for fpga loadmk command
2697 CONFIG_CMD_FPGA_LOADP
2699 Enable support for fpga loadp command - load partial bitstream
2701 CONFIG_CMD_FPGA_LOADBP
2703 Enable support for fpga loadbp command - load partial bitstream
2706 CONFIG_SYS_FPGA_PROG_FEEDBACK
2708 Enable printing of hash marks during FPGA configuration.
2710 CONFIG_SYS_FPGA_CHECK_BUSY
2712 Enable checks on FPGA configuration interface busy
2713 status by the configuration function. This option
2714 will require a board or device specific function to
2719 If defined, a function that provides delays in the FPGA
2720 configuration driver.
2722 CONFIG_SYS_FPGA_CHECK_CTRLC
2723 Allow Control-C to interrupt FPGA configuration
2725 CONFIG_SYS_FPGA_CHECK_ERROR
2727 Check for configuration errors during FPGA bitfile
2728 loading. For example, abort during Virtex II
2729 configuration if the INIT_B line goes low (which
2730 indicated a CRC error).
2732 CONFIG_SYS_FPGA_WAIT_INIT
2734 Maximum time to wait for the INIT_B line to de-assert
2735 after PROB_B has been de-asserted during a Virtex II
2736 FPGA configuration sequence. The default time is 500
2739 CONFIG_SYS_FPGA_WAIT_BUSY
2741 Maximum time to wait for BUSY to de-assert during
2742 Virtex II FPGA configuration. The default is 5 ms.
2744 CONFIG_SYS_FPGA_WAIT_CONFIG
2746 Time to wait after FPGA configuration. The default is
2749 - Configuration Management:
2752 Some SoCs need special image types (e.g. U-Boot binary
2753 with a special header) as build targets. By defining
2754 CONFIG_BUILD_TARGET in the SoC / board header, this
2755 special image will be automatically built upon calling
2760 If defined, this string will be added to the U-Boot
2761 version information (U_BOOT_VERSION)
2763 - Vendor Parameter Protection:
2765 U-Boot considers the values of the environment
2766 variables "serial#" (Board Serial Number) and
2767 "ethaddr" (Ethernet Address) to be parameters that
2768 are set once by the board vendor / manufacturer, and
2769 protects these variables from casual modification by
2770 the user. Once set, these variables are read-only,
2771 and write or delete attempts are rejected. You can
2772 change this behaviour:
2774 If CONFIG_ENV_OVERWRITE is #defined in your config
2775 file, the write protection for vendor parameters is
2776 completely disabled. Anybody can change or delete
2779 Alternatively, if you define _both_ an ethaddr in the
2780 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2781 Ethernet address is installed in the environment,
2782 which can be changed exactly ONCE by the user. [The
2783 serial# is unaffected by this, i. e. it remains
2786 The same can be accomplished in a more flexible way
2787 for any variable by configuring the type of access
2788 to allow for those variables in the ".flags" variable
2789 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2794 Define this variable to enable the reservation of
2795 "protected RAM", i. e. RAM which is not overwritten
2796 by U-Boot. Define CONFIG_PRAM to hold the number of
2797 kB you want to reserve for pRAM. You can overwrite
2798 this default value by defining an environment
2799 variable "pram" to the number of kB you want to
2800 reserve. Note that the board info structure will
2801 still show the full amount of RAM. If pRAM is
2802 reserved, a new environment variable "mem" will
2803 automatically be defined to hold the amount of
2804 remaining RAM in a form that can be passed as boot
2805 argument to Linux, for instance like that:
2807 setenv bootargs ... mem=\${mem}
2810 This way you can tell Linux not to use this memory,
2811 either, which results in a memory region that will
2812 not be affected by reboots.
2814 *WARNING* If your board configuration uses automatic
2815 detection of the RAM size, you must make sure that
2816 this memory test is non-destructive. So far, the
2817 following board configurations are known to be
2820 IVMS8, IVML24, SPD8xx, TQM8xxL,
2821 HERMES, IP860, RPXlite, LWMON,
2824 - Access to physical memory region (> 4GB)
2825 Some basic support is provided for operations on memory not
2826 normally accessible to U-Boot - e.g. some architectures
2827 support access to more than 4GB of memory on 32-bit
2828 machines using physical address extension or similar.
2829 Define CONFIG_PHYSMEM to access this basic support, which
2830 currently only supports clearing the memory.
2835 Define this variable to stop the system in case of a
2836 fatal error, so that you have to reset it manually.
2837 This is probably NOT a good idea for an embedded
2838 system where you want the system to reboot
2839 automatically as fast as possible, but it may be
2840 useful during development since you can try to debug
2841 the conditions that lead to the situation.
2843 CONFIG_NET_RETRY_COUNT
2845 This variable defines the number of retries for
2846 network operations like ARP, RARP, TFTP, or BOOTP
2847 before giving up the operation. If not defined, a
2848 default value of 5 is used.
2852 Timeout waiting for an ARP reply in milliseconds.
2856 Timeout in milliseconds used in NFS protocol.
2857 If you encounter "ERROR: Cannot umount" in nfs command,
2858 try longer timeout such as
2859 #define CONFIG_NFS_TIMEOUT 10000UL
2861 - Command Interpreter:
2862 CONFIG_AUTO_COMPLETE
2864 Enable auto completion of commands using TAB.
2866 CONFIG_SYS_PROMPT_HUSH_PS2
2868 This defines the secondary prompt string, which is
2869 printed when the command interpreter needs more input
2870 to complete a command. Usually "> ".
2874 In the current implementation, the local variables
2875 space and global environment variables space are
2876 separated. Local variables are those you define by
2877 simply typing `name=value'. To access a local
2878 variable later on, you have write `$name' or
2879 `${name}'; to execute the contents of a variable
2880 directly type `$name' at the command prompt.
2882 Global environment variables are those you use
2883 setenv/printenv to work with. To run a command stored
2884 in such a variable, you need to use the run command,
2885 and you must not use the '$' sign to access them.
2887 To store commands and special characters in a
2888 variable, please use double quotation marks
2889 surrounding the whole text of the variable, instead
2890 of the backslashes before semicolons and special
2893 - Command Line Editing and History:
2894 CONFIG_CMDLINE_EDITING
2896 Enable editing and History functions for interactive
2897 command line input operations
2899 - Command Line PS1/PS2 support:
2900 CONFIG_CMDLINE_PS_SUPPORT
2902 Enable support for changing the command prompt string
2903 at run-time. Only static string is supported so far.
2904 The string is obtained from environment variables PS1
2907 - Default Environment:
2908 CONFIG_EXTRA_ENV_SETTINGS
2910 Define this to contain any number of null terminated
2911 strings (variable = value pairs) that will be part of
2912 the default environment compiled into the boot image.
2914 For example, place something like this in your
2915 board's config file:
2917 #define CONFIG_EXTRA_ENV_SETTINGS \
2921 Warning: This method is based on knowledge about the
2922 internal format how the environment is stored by the
2923 U-Boot code. This is NOT an official, exported
2924 interface! Although it is unlikely that this format
2925 will change soon, there is no guarantee either.
2926 You better know what you are doing here.
2928 Note: overly (ab)use of the default environment is
2929 discouraged. Make sure to check other ways to preset
2930 the environment like the "source" command or the
2933 CONFIG_ENV_VARS_UBOOT_CONFIG
2935 Define this in order to add variables describing the
2936 U-Boot build configuration to the default environment.
2937 These will be named arch, cpu, board, vendor, and soc.
2939 Enabling this option will cause the following to be defined:
2947 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2949 Define this in order to add variables describing certain
2950 run-time determined information about the hardware to the
2951 environment. These will be named board_name, board_rev.
2953 CONFIG_DELAY_ENVIRONMENT
2955 Normally the environment is loaded when the board is
2956 initialised so that it is available to U-Boot. This inhibits
2957 that so that the environment is not available until
2958 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2959 this is instead controlled by the value of
2960 /config/load-environment.
2962 - Parallel Flash support:
2965 Traditionally U-Boot was run on systems with parallel NOR
2966 flash. This option is used to disable support for parallel NOR
2967 flash. This option should be defined if the board does not have
2970 If this option is not defined one of the generic flash drivers
2971 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2972 selected or the board must provide an implementation of the
2973 flash API (see include/flash.h).
2975 - DataFlash Support:
2976 CONFIG_HAS_DATAFLASH
2978 Defining this option enables DataFlash features and
2979 allows to read/write in Dataflash via the standard
2982 - Serial Flash support
2985 Defining this option enables SPI flash commands
2986 'sf probe/read/write/erase/update'.
2988 Usage requires an initial 'probe' to define the serial
2989 flash parameters, followed by read/write/erase/update
2992 The following defaults may be provided by the platform
2993 to handle the common case when only a single serial
2994 flash is present on the system.
2996 CONFIG_SF_DEFAULT_BUS Bus identifier
2997 CONFIG_SF_DEFAULT_CS Chip-select
2998 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2999 CONFIG_SF_DEFAULT_SPEED in Hz
3003 Define this option to include a destructive SPI flash
3006 CONFIG_SF_DUAL_FLASH Dual flash memories
3008 Define this option to use dual flash support where two flash
3009 memories can be connected with a given cs line.
3010 Currently Xilinx Zynq qspi supports these type of connections.
3012 - SystemACE Support:
3015 Adding this option adds support for Xilinx SystemACE
3016 chips attached via some sort of local bus. The address
3017 of the chip must also be defined in the
3018 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3020 #define CONFIG_SYSTEMACE
3021 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3023 When SystemACE support is added, the "ace" device type
3024 becomes available to the fat commands, i.e. fatls.
3026 - TFTP Fixed UDP Port:
3029 If this is defined, the environment variable tftpsrcp
3030 is used to supply the TFTP UDP source port value.
3031 If tftpsrcp isn't defined, the normal pseudo-random port
3032 number generator is used.
3034 Also, the environment variable tftpdstp is used to supply
3035 the TFTP UDP destination port value. If tftpdstp isn't
3036 defined, the normal port 69 is used.
3038 The purpose for tftpsrcp is to allow a TFTP server to
3039 blindly start the TFTP transfer using the pre-configured
3040 target IP address and UDP port. This has the effect of
3041 "punching through" the (Windows XP) firewall, allowing
3042 the remainder of the TFTP transfer to proceed normally.
3043 A better solution is to properly configure the firewall,
3044 but sometimes that is not allowed.
3049 This enables a generic 'hash' command which can produce
3050 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3054 Enable the hash verify command (hash -v). This adds to code
3057 CONFIG_SHA1 - This option enables support of hashing using SHA1
3058 algorithm. The hash is calculated in software.
3059 CONFIG_SHA256 - This option enables support of hashing using
3060 SHA256 algorithm. The hash is calculated in software.
3061 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3062 for SHA1/SHA256 hashing.
3063 This affects the 'hash' command and also the
3064 hash_lookup_algo() function.
3065 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3066 hardware-acceleration for SHA1/SHA256 progressive hashing.
3067 Data can be streamed in a block at a time and the hashing
3068 is performed in hardware.
3070 Note: There is also a sha1sum command, which should perhaps
3071 be deprecated in favour of 'hash sha1'.
3073 - Freescale i.MX specific commands:
3074 CONFIG_CMD_HDMIDETECT
3075 This enables 'hdmidet' command which returns true if an
3076 HDMI monitor is detected. This command is i.MX 6 specific.
3079 This enables the 'bmode' (bootmode) command for forcing
3080 a boot from specific media.
3082 This is useful for forcing the ROM's usb downloader to
3083 activate upon a watchdog reset which is nice when iterating
3084 on U-Boot. Using the reset button or running bmode normal
3085 will set it back to normal. This command currently
3086 supports i.MX53 and i.MX6.
3088 - bootcount support:
3089 CONFIG_BOOTCOUNT_LIMIT
3091 This enables the bootcounter support, see:
3092 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3095 enable special bootcounter support on at91sam9xe based boards.
3097 enable special bootcounter support on blackfin based boards.
3099 enable special bootcounter support on da850 based boards.
3100 CONFIG_BOOTCOUNT_RAM
3101 enable support for the bootcounter in RAM
3102 CONFIG_BOOTCOUNT_I2C
3103 enable support for the bootcounter on an i2c (like RTC) device.
3104 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3105 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3107 CONFIG_BOOTCOUNT_ALEN = address len
3109 - Show boot progress:
3110 CONFIG_SHOW_BOOT_PROGRESS
3112 Defining this option allows to add some board-
3113 specific code (calling a user-provided function
3114 "show_boot_progress(int)") that enables you to show
3115 the system's boot progress on some display (for
3116 example, some LED's) on your board. At the moment,
3117 the following checkpoints are implemented:
3120 Legacy uImage format:
3123 1 common/cmd_bootm.c before attempting to boot an image
3124 -1 common/cmd_bootm.c Image header has bad magic number
3125 2 common/cmd_bootm.c Image header has correct magic number
3126 -2 common/cmd_bootm.c Image header has bad checksum
3127 3 common/cmd_bootm.c Image header has correct checksum
3128 -3 common/cmd_bootm.c Image data has bad checksum
3129 4 common/cmd_bootm.c Image data has correct checksum
3130 -4 common/cmd_bootm.c Image is for unsupported architecture
3131 5 common/cmd_bootm.c Architecture check OK
3132 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3133 6 common/cmd_bootm.c Image Type check OK
3134 -6 common/cmd_bootm.c gunzip uncompression error
3135 -7 common/cmd_bootm.c Unimplemented compression type
3136 7 common/cmd_bootm.c Uncompression OK
3137 8 common/cmd_bootm.c No uncompress/copy overwrite error
3138 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3140 9 common/image.c Start initial ramdisk verification
3141 -10 common/image.c Ramdisk header has bad magic number
3142 -11 common/image.c Ramdisk header has bad checksum
3143 10 common/image.c Ramdisk header is OK
3144 -12 common/image.c Ramdisk data has bad checksum
3145 11 common/image.c Ramdisk data has correct checksum
3146 12 common/image.c Ramdisk verification complete, start loading
3147 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3148 13 common/image.c Start multifile image verification
3149 14 common/image.c No initial ramdisk, no multifile, continue.
3151 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3153 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3154 -31 post/post.c POST test failed, detected by post_output_backlog()
3155 -32 post/post.c POST test failed, detected by post_run_single()
3157 34 common/cmd_doc.c before loading a Image from a DOC device
3158 -35 common/cmd_doc.c Bad usage of "doc" command
3159 35 common/cmd_doc.c correct usage of "doc" command
3160 -36 common/cmd_doc.c No boot device
3161 36 common/cmd_doc.c correct boot device
3162 -37 common/cmd_doc.c Unknown Chip ID on boot device
3163 37 common/cmd_doc.c correct chip ID found, device available
3164 -38 common/cmd_doc.c Read Error on boot device
3165 38 common/cmd_doc.c reading Image header from DOC device OK
3166 -39 common/cmd_doc.c Image header has bad magic number
3167 39 common/cmd_doc.c Image header has correct magic number
3168 -40 common/cmd_doc.c Error reading Image from DOC device
3169 40 common/cmd_doc.c Image header has correct magic number
3170 41 common/cmd_ide.c before loading a Image from a IDE device
3171 -42 common/cmd_ide.c Bad usage of "ide" command
3172 42 common/cmd_ide.c correct usage of "ide" command
3173 -43 common/cmd_ide.c No boot device
3174 43 common/cmd_ide.c boot device found
3175 -44 common/cmd_ide.c Device not available
3176 44 common/cmd_ide.c Device available
3177 -45 common/cmd_ide.c wrong partition selected
3178 45 common/cmd_ide.c partition selected
3179 -46 common/cmd_ide.c Unknown partition table
3180 46 common/cmd_ide.c valid partition table found
3181 -47 common/cmd_ide.c Invalid partition type
3182 47 common/cmd_ide.c correct partition type
3183 -48 common/cmd_ide.c Error reading Image Header on boot device
3184 48 common/cmd_ide.c reading Image Header from IDE device OK
3185 -49 common/cmd_ide.c Image header has bad magic number
3186 49 common/cmd_ide.c Image header has correct magic number
3187 -50 common/cmd_ide.c Image header has bad checksum
3188 50 common/cmd_ide.c Image header has correct checksum
3189 -51 common/cmd_ide.c Error reading Image from IDE device
3190 51 common/cmd_ide.c reading Image from IDE device OK
3191 52 common/cmd_nand.c before loading a Image from a NAND device
3192 -53 common/cmd_nand.c Bad usage of "nand" command
3193 53 common/cmd_nand.c correct usage of "nand" command
3194 -54 common/cmd_nand.c No boot device
3195 54 common/cmd_nand.c boot device found
3196 -55 common/cmd_nand.c Unknown Chip ID on boot device
3197 55 common/cmd_nand.c correct chip ID found, device available
3198 -56 common/cmd_nand.c Error reading Image Header on boot device
3199 56 common/cmd_nand.c reading Image Header from NAND device OK
3200 -57 common/cmd_nand.c Image header has bad magic number
3201 57 common/cmd_nand.c Image header has correct magic number
3202 -58 common/cmd_nand.c Error reading Image from NAND device
3203 58 common/cmd_nand.c reading Image from NAND device OK
3205 -60 common/env_common.c Environment has a bad CRC, using default
3207 64 net/eth.c starting with Ethernet configuration.
3208 -64 net/eth.c no Ethernet found.
3209 65 net/eth.c Ethernet found.
3211 -80 common/cmd_net.c usage wrong
3212 80 common/cmd_net.c before calling net_loop()
3213 -81 common/cmd_net.c some error in net_loop() occurred
3214 81 common/cmd_net.c net_loop() back without error
3215 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3216 82 common/cmd_net.c trying automatic boot
3217 83 common/cmd_net.c running "source" command
3218 -83 common/cmd_net.c some error in automatic boot or "source" command
3219 84 common/cmd_net.c end without errors
3224 100 common/cmd_bootm.c Kernel FIT Image has correct format
3225 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3226 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3227 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3228 102 common/cmd_bootm.c Kernel unit name specified
3229 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3230 103 common/cmd_bootm.c Found configuration node
3231 104 common/cmd_bootm.c Got kernel subimage node offset
3232 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3233 105 common/cmd_bootm.c Kernel subimage hash verification OK
3234 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3235 106 common/cmd_bootm.c Architecture check OK
3236 -106 common/cmd_bootm.c Kernel subimage has wrong type
3237 107 common/cmd_bootm.c Kernel subimage type OK
3238 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3239 108 common/cmd_bootm.c Got kernel subimage data/size
3240 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3241 -109 common/cmd_bootm.c Can't get kernel subimage type
3242 -110 common/cmd_bootm.c Can't get kernel subimage comp
3243 -111 common/cmd_bootm.c Can't get kernel subimage os
3244 -112 common/cmd_bootm.c Can't get kernel subimage load address
3245 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3247 120 common/image.c Start initial ramdisk verification
3248 -120 common/image.c Ramdisk FIT image has incorrect format
3249 121 common/image.c Ramdisk FIT image has correct format
3250 122 common/image.c No ramdisk subimage unit name, using configuration
3251 -122 common/image.c Can't get configuration for ramdisk subimage
3252 123 common/image.c Ramdisk unit name specified
3253 -124 common/image.c Can't get ramdisk subimage node offset
3254 125 common/image.c Got ramdisk subimage node offset
3255 -125 common/image.c Ramdisk subimage hash verification failed
3256 126 common/image.c Ramdisk subimage hash verification OK
3257 -126 common/image.c Ramdisk subimage for unsupported architecture
3258 127 common/image.c Architecture check OK
3259 -127 common/image.c Can't get ramdisk subimage data/size
3260 128 common/image.c Got ramdisk subimage data/size
3261 129 common/image.c Can't get ramdisk load address
3262 -129 common/image.c Got ramdisk load address
3264 -130 common/cmd_doc.c Incorrect FIT image format
3265 131 common/cmd_doc.c FIT image format OK
3267 -140 common/cmd_ide.c Incorrect FIT image format
3268 141 common/cmd_ide.c FIT image format OK
3270 -150 common/cmd_nand.c Incorrect FIT image format
3271 151 common/cmd_nand.c FIT image format OK
3273 - legacy image format:
3274 CONFIG_IMAGE_FORMAT_LEGACY
3275 enables the legacy image format support in U-Boot.
3278 enabled if CONFIG_FIT_SIGNATURE is not defined.
3280 CONFIG_DISABLE_IMAGE_LEGACY
3281 disable the legacy image format
3283 This define is introduced, as the legacy image format is
3284 enabled per default for backward compatibility.
3286 - FIT image support:
3287 CONFIG_FIT_DISABLE_SHA256
3288 Supporting SHA256 hashes has quite an impact on binary size.
3289 For constrained systems sha256 hash support can be disabled
3292 TODO(sjg@chromium.org): Adjust this option to be positive,
3293 and move it to Kconfig
3295 - Standalone program support:
3296 CONFIG_STANDALONE_LOAD_ADDR
3298 This option defines a board specific value for the
3299 address where standalone program gets loaded, thus
3300 overwriting the architecture dependent default
3303 - Frame Buffer Address:
3306 Define CONFIG_FB_ADDR if you want to use specific
3307 address for frame buffer. This is typically the case
3308 when using a graphics controller has separate video
3309 memory. U-Boot will then place the frame buffer at
3310 the given address instead of dynamically reserving it
3311 in system RAM by calling lcd_setmem(), which grabs
3312 the memory for the frame buffer depending on the
3313 configured panel size.
3315 Please see board_init_f function.
3317 - Automatic software updates via TFTP server
3319 CONFIG_UPDATE_TFTP_CNT_MAX
3320 CONFIG_UPDATE_TFTP_MSEC_MAX
3322 These options enable and control the auto-update feature;
3323 for a more detailed description refer to doc/README.update.
3325 - MTD Support (mtdparts command, UBI support)
3328 Adds the MTD device infrastructure from the Linux kernel.
3329 Needed for mtdparts command support.
3331 CONFIG_MTD_PARTITIONS
3333 Adds the MTD partitioning infrastructure from the Linux
3334 kernel. Needed for UBI support.
3339 Adds commands for interacting with MTD partitions formatted
3340 with the UBI flash translation layer
3342 Requires also defining CONFIG_RBTREE
3344 CONFIG_UBI_SILENCE_MSG
3346 Make the verbose messages from UBI stop printing. This leaves
3347 warnings and errors enabled.
3350 CONFIG_MTD_UBI_WL_THRESHOLD
3351 This parameter defines the maximum difference between the highest
3352 erase counter value and the lowest erase counter value of eraseblocks
3353 of UBI devices. When this threshold is exceeded, UBI starts performing
3354 wear leveling by means of moving data from eraseblock with low erase
3355 counter to eraseblocks with high erase counter.
3357 The default value should be OK for SLC NAND flashes, NOR flashes and
3358 other flashes which have eraseblock life-cycle 100000 or more.
3359 However, in case of MLC NAND flashes which typically have eraseblock
3360 life-cycle less than 10000, the threshold should be lessened (e.g.,
3361 to 128 or 256, although it does not have to be power of 2).
3365 CONFIG_MTD_UBI_BEB_LIMIT
3366 This option specifies the maximum bad physical eraseblocks UBI
3367 expects on the MTD device (per 1024 eraseblocks). If the
3368 underlying flash does not admit of bad eraseblocks (e.g. NOR
3369 flash), this value is ignored.
3371 NAND datasheets often specify the minimum and maximum NVM
3372 (Number of Valid Blocks) for the flashes' endurance lifetime.
3373 The maximum expected bad eraseblocks per 1024 eraseblocks
3374 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3375 which gives 20 for most NANDs (MaxNVB is basically the total
3376 count of eraseblocks on the chip).
3378 To put it differently, if this value is 20, UBI will try to
3379 reserve about 1.9% of physical eraseblocks for bad blocks
3380 handling. And that will be 1.9% of eraseblocks on the entire
3381 NAND chip, not just the MTD partition UBI attaches. This means
3382 that if you have, say, a NAND flash chip admits maximum 40 bad
3383 eraseblocks, and it is split on two MTD partitions of the same
3384 size, UBI will reserve 40 eraseblocks when attaching a
3389 CONFIG_MTD_UBI_FASTMAP
3390 Fastmap is a mechanism which allows attaching an UBI device
3391 in nearly constant time. Instead of scanning the whole MTD device it
3392 only has to locate a checkpoint (called fastmap) on the device.
3393 The on-flash fastmap contains all information needed to attach
3394 the device. Using fastmap makes only sense on large devices where
3395 attaching by scanning takes long. UBI will not automatically install
3396 a fastmap on old images, but you can set the UBI parameter
3397 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3398 that fastmap-enabled images are still usable with UBI implementations
3399 without fastmap support. On typical flash devices the whole fastmap
3400 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3402 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3403 Set this parameter to enable fastmap automatically on images
3407 CONFIG_MTD_UBI_FM_DEBUG
3408 Enable UBI fastmap debug
3414 Adds commands for interacting with UBI volumes formatted as
3415 UBIFS. UBIFS is read-only in u-boot.
3417 Requires UBI support as well as CONFIG_LZO
3419 CONFIG_UBIFS_SILENCE_MSG
3421 Make the verbose messages from UBIFS stop printing. This leaves
3422 warnings and errors enabled.
3426 Enable building of SPL globally.
3429 LDSCRIPT for linking the SPL binary.
3431 CONFIG_SPL_MAX_FOOTPRINT
3432 Maximum size in memory allocated to the SPL, BSS included.
3433 When defined, the linker checks that the actual memory
3434 used by SPL from _start to __bss_end does not exceed it.
3435 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3436 must not be both defined at the same time.
3439 Maximum size of the SPL image (text, data, rodata, and
3440 linker lists sections), BSS excluded.
3441 When defined, the linker checks that the actual size does
3444 CONFIG_SPL_TEXT_BASE
3445 TEXT_BASE for linking the SPL binary.
3447 CONFIG_SPL_RELOC_TEXT_BASE
3448 Address to relocate to. If unspecified, this is equal to
3449 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3451 CONFIG_SPL_BSS_START_ADDR
3452 Link address for the BSS within the SPL binary.
3454 CONFIG_SPL_BSS_MAX_SIZE
3455 Maximum size in memory allocated to the SPL BSS.
3456 When defined, the linker checks that the actual memory used
3457 by SPL from __bss_start to __bss_end does not exceed it.
3458 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3459 must not be both defined at the same time.
3462 Adress of the start of the stack SPL will use
3464 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3465 When defined, SPL will panic() if the image it has
3466 loaded does not have a signature.
3467 Defining this is useful when code which loads images
3468 in SPL cannot guarantee that absolutely all read errors
3470 An example is the LPC32XX MLC NAND driver, which will
3471 consider that a completely unreadable NAND block is bad,
3472 and thus should be skipped silently.
3474 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3475 When defined, SPL will proceed to another boot method
3476 if the image it has loaded does not have a signature.
3478 CONFIG_SPL_RELOC_STACK
3479 Adress of the start of the stack SPL will use after
3480 relocation. If unspecified, this is equal to
3483 CONFIG_SYS_SPL_MALLOC_START
3484 Starting address of the malloc pool used in SPL.
3485 When this option is set the full malloc is used in SPL and
3486 it is set up by spl_init() and before that, the simple malloc()
3487 can be used if CONFIG_SYS_MALLOC_F is defined.
3489 CONFIG_SYS_SPL_MALLOC_SIZE
3490 The size of the malloc pool used in SPL.
3492 CONFIG_SPL_FRAMEWORK
3493 Enable the SPL framework under common/. This framework
3494 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3495 NAND loading of the Linux Kernel.
3498 Enable booting directly to an OS from SPL.
3499 See also: doc/README.falcon
3501 CONFIG_SPL_DISPLAY_PRINT
3502 For ARM, enable an optional function to print more information
3503 about the running system.
3505 CONFIG_SPL_INIT_MINIMAL
3506 Arch init code should be built for a very small image
3508 CONFIG_SPL_LIBCOMMON_SUPPORT
3509 Support for common/libcommon.o in SPL binary
3511 CONFIG_SPL_LIBDISK_SUPPORT
3512 Support for disk/libdisk.o in SPL binary
3514 CONFIG_SPL_I2C_SUPPORT
3515 Support for drivers/i2c/libi2c.o in SPL binary
3517 CONFIG_SPL_GPIO_SUPPORT
3518 Support for drivers/gpio/libgpio.o in SPL binary
3520 CONFIG_SPL_MMC_SUPPORT
3521 Support for drivers/mmc/libmmc.o in SPL binary
3523 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3524 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3525 Address and partition on the MMC to load U-Boot from
3526 when the MMC is being used in raw mode.
3528 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3529 Partition on the MMC to load U-Boot from when the MMC is being
3532 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3533 Sector to load kernel uImage from when MMC is being
3534 used in raw mode (for Falcon mode)
3536 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3537 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3538 Sector and number of sectors to load kernel argument
3539 parameters from when MMC is being used in raw mode
3542 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3543 Partition on the MMC to load U-Boot from when the MMC is being
3546 CONFIG_SPL_FAT_SUPPORT
3547 Support for fs/fat/libfat.o in SPL binary
3549 CONFIG_SPL_EXT_SUPPORT
3550 Support for EXT filesystem in SPL binary
3552 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3553 Filename to read to load U-Boot when reading from filesystem
3555 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3556 Filename to read to load kernel uImage when reading
3557 from filesystem (for Falcon mode)
3559 CONFIG_SPL_FS_LOAD_ARGS_NAME
3560 Filename to read to load kernel argument parameters
3561 when reading from filesystem (for Falcon mode)
3563 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3564 Set this for NAND SPL on PPC mpc83xx targets, so that
3565 start.S waits for the rest of the SPL to load before
3566 continuing (the hardware starts execution after just
3567 loading the first page rather than the full 4K).
3569 CONFIG_SPL_SKIP_RELOCATE
3570 Avoid SPL relocation
3572 CONFIG_SPL_NAND_BASE
3573 Include nand_base.c in the SPL. Requires
3574 CONFIG_SPL_NAND_DRIVERS.
3576 CONFIG_SPL_NAND_DRIVERS
3577 SPL uses normal NAND drivers, not minimal drivers.
3580 Include standard software ECC in the SPL
3582 CONFIG_SPL_NAND_SIMPLE
3583 Support for NAND boot using simple NAND drivers that
3584 expose the cmd_ctrl() interface.
3586 CONFIG_SPL_MTD_SUPPORT
3587 Support for the MTD subsystem within SPL. Useful for
3588 environment on NAND support within SPL.
3590 CONFIG_SPL_NAND_RAW_ONLY
3591 Support to boot only raw u-boot.bin images. Use this only
3592 if you need to save space.
3594 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3595 Set for the SPL on PPC mpc8xxx targets, support for
3596 drivers/ddr/fsl/libddr.o in SPL binary.
3598 CONFIG_SPL_COMMON_INIT_DDR
3599 Set for common ddr init with serial presence detect in
3602 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3603 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3604 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3605 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3606 CONFIG_SYS_NAND_ECCBYTES
3607 Defines the size and behavior of the NAND that SPL uses
3610 CONFIG_SPL_NAND_BOOT
3611 Add support NAND boot
3613 CONFIG_SYS_NAND_U_BOOT_OFFS
3614 Location in NAND to read U-Boot from
3616 CONFIG_SYS_NAND_U_BOOT_DST
3617 Location in memory to load U-Boot to
3619 CONFIG_SYS_NAND_U_BOOT_SIZE
3620 Size of image to load
3622 CONFIG_SYS_NAND_U_BOOT_START
3623 Entry point in loaded image to jump to
3625 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3626 Define this if you need to first read the OOB and then the
3627 data. This is used, for example, on davinci platforms.
3629 CONFIG_SPL_OMAP3_ID_NAND
3630 Support for an OMAP3-specific set of functions to return the
3631 ID and MFR of the first attached NAND chip, if present.
3633 CONFIG_SPL_SERIAL_SUPPORT
3634 Support for drivers/serial/libserial.o in SPL binary
3636 CONFIG_SPL_SPI_FLASH_SUPPORT
3637 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3639 CONFIG_SPL_SPI_SUPPORT
3640 Support for drivers/spi/libspi.o in SPL binary
3642 CONFIG_SPL_RAM_DEVICE
3643 Support for running image already present in ram, in SPL binary
3645 CONFIG_SPL_LIBGENERIC_SUPPORT
3646 Support for lib/libgeneric.o in SPL binary
3648 CONFIG_SPL_ENV_SUPPORT
3649 Support for the environment operating in SPL binary
3651 CONFIG_SPL_NET_SUPPORT
3652 Support for the net/libnet.o in SPL binary.
3653 It conflicts with SPL env from storage medium specified by
3654 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3657 Image offset to which the SPL should be padded before appending
3658 the SPL payload. By default, this is defined as
3659 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3660 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3661 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3664 Final target image containing SPL and payload. Some SPLs
3665 use an arch-specific makefile fragment instead, for
3666 example if more than one image needs to be produced.
3668 CONFIG_FIT_SPL_PRINT
3669 Printing information about a FIT image adds quite a bit of
3670 code to SPL. So this is normally disabled in SPL. Use this
3671 option to re-enable it. This will affect the output of the
3672 bootm command when booting a FIT image.
3676 Enable building of TPL globally.
3679 Image offset to which the TPL should be padded before appending
3680 the TPL payload. By default, this is defined as
3681 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3682 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3683 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3685 - Interrupt support (PPC):
3687 There are common interrupt_init() and timer_interrupt()
3688 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3689 for CPU specific initialization. interrupt_init_cpu()
3690 should set decrementer_count to appropriate value. If
3691 CPU resets decrementer automatically after interrupt
3692 (ppc4xx) it should set decrementer_count to zero.
3693 timer_interrupt() calls timer_interrupt_cpu() for CPU
3694 specific handling. If board has watchdog / status_led
3695 / other_activity_monitor it works automatically from
3696 general timer_interrupt().
3699 Board initialization settings:
3700 ------------------------------
3702 During Initialization u-boot calls a number of board specific functions
3703 to allow the preparation of board specific prerequisites, e.g. pin setup
3704 before drivers are initialized. To enable these callbacks the
3705 following configuration macros have to be defined. Currently this is
3706 architecture specific, so please check arch/your_architecture/lib/board.c
3707 typically in board_init_f() and board_init_r().
3709 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3710 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3711 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3712 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3714 Configuration Settings:
3715 -----------------------
3717 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3718 Optionally it can be defined to support 64-bit memory commands.
3720 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3721 undefine this when you're short of memory.
3723 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3724 width of the commands listed in the 'help' command output.
3726 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3727 prompt for user input.
3729 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3731 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3733 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3735 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3736 the application (usually a Linux kernel) when it is
3739 - CONFIG_SYS_BAUDRATE_TABLE:
3740 List of legal baudrate settings for this board.
3742 - CONFIG_SYS_CONSOLE_INFO_QUIET
3743 Suppress display of console information at boot.
3745 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3746 If the board specific function
3747 extern int overwrite_console (void);
3748 returns 1, the stdin, stderr and stdout are switched to the
3749 serial port, else the settings in the environment are used.
3751 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3752 Enable the call to overwrite_console().
3754 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3755 Enable overwrite of previous console environment settings.
3757 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3758 Begin and End addresses of the area used by the
3761 - CONFIG_SYS_ALT_MEMTEST:
3762 Enable an alternate, more extensive memory test.
3764 - CONFIG_SYS_MEMTEST_SCRATCH:
3765 Scratch address used by the alternate memory test
3766 You only need to set this if address zero isn't writeable
3768 - CONFIG_SYS_MEM_RESERVE_SECURE
3769 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3770 is substracted from total RAM and won't be reported to OS.
3771 This memory can be used as secure memory. A variable
3772 gd->secure_ram is used to track the location. In systems
3773 the RAM base is not zero, or RAM is divided into banks,
3774 this variable needs to be recalcuated to get the address.
3776 - CONFIG_SYS_MEM_TOP_HIDE:
3777 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3778 this specified memory area will get subtracted from the top
3779 (end) of RAM and won't get "touched" at all by U-Boot. By
3780 fixing up gd->ram_size the Linux kernel should gets passed
3781 the now "corrected" memory size and won't touch it either.
3782 This should work for arch/ppc and arch/powerpc. Only Linux
3783 board ports in arch/powerpc with bootwrapper support that
3784 recalculate the memory size from the SDRAM controller setup
3785 will have to get fixed in Linux additionally.
3787 This option can be used as a workaround for the 440EPx/GRx
3788 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3791 WARNING: Please make sure that this value is a multiple of
3792 the Linux page size (normally 4k). If this is not the case,
3793 then the end address of the Linux memory will be located at a
3794 non page size aligned address and this could cause major
3797 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3798 Enable temporary baudrate change while serial download
3800 - CONFIG_SYS_SDRAM_BASE:
3801 Physical start address of SDRAM. _Must_ be 0 here.
3803 - CONFIG_SYS_MBIO_BASE:
3804 Physical start address of Motherboard I/O (if using a
3807 - CONFIG_SYS_FLASH_BASE:
3808 Physical start address of Flash memory.
3810 - CONFIG_SYS_MONITOR_BASE:
3811 Physical start address of boot monitor code (set by
3812 make config files to be same as the text base address
3813 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3814 CONFIG_SYS_FLASH_BASE when booting from flash.
3816 - CONFIG_SYS_MONITOR_LEN:
3817 Size of memory reserved for monitor code, used to
3818 determine _at_compile_time_ (!) if the environment is
3819 embedded within the U-Boot image, or in a separate
3822 - CONFIG_SYS_MALLOC_LEN:
3823 Size of DRAM reserved for malloc() use.
3825 - CONFIG_SYS_MALLOC_F_LEN
3826 Size of the malloc() pool for use before relocation. If
3827 this is defined, then a very simple malloc() implementation
3828 will become available before relocation. The address is just
3829 below the global data, and the stack is moved down to make
3832 This feature allocates regions with increasing addresses
3833 within the region. calloc() is supported, but realloc()
3834 is not available. free() is supported but does nothing.
3835 The memory will be freed (or in fact just forgotten) when
3836 U-Boot relocates itself.
3838 - CONFIG_SYS_MALLOC_SIMPLE
3839 Provides a simple and small malloc() and calloc() for those
3840 boards which do not use the full malloc in SPL (which is
3841 enabled with CONFIG_SYS_SPL_MALLOC_START).
3843 - CONFIG_SYS_NONCACHED_MEMORY:
3844 Size of non-cached memory area. This area of memory will be
3845 typically located right below the malloc() area and mapped
3846 uncached in the MMU. This is useful for drivers that would
3847 otherwise require a lot of explicit cache maintenance. For
3848 some drivers it's also impossible to properly maintain the
3849 cache. For example if the regions that need to be flushed
3850 are not a multiple of the cache-line size, *and* padding
3851 cannot be allocated between the regions to align them (i.e.
3852 if the HW requires a contiguous array of regions, and the
3853 size of each region is not cache-aligned), then a flush of
3854 one region may result in overwriting data that hardware has
3855 written to another region in the same cache-line. This can
3856 happen for example in network drivers where descriptors for
3857 buffers are typically smaller than the CPU cache-line (e.g.
3858 16 bytes vs. 32 or 64 bytes).
3860 Non-cached memory is only supported on 32-bit ARM at present.
3862 - CONFIG_SYS_BOOTM_LEN:
3863 Normally compressed uImages are limited to an
3864 uncompressed size of 8 MBytes. If this is not enough,
3865 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3866 to adjust this setting to your needs.
3868 - CONFIG_SYS_BOOTMAPSZ:
3869 Maximum size of memory mapped by the startup code of
3870 the Linux kernel; all data that must be processed by
3871 the Linux kernel (bd_info, boot arguments, FDT blob if
3872 used) must be put below this limit, unless "bootm_low"
3873 environment variable is defined and non-zero. In such case
3874 all data for the Linux kernel must be between "bootm_low"
3875 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3876 variable "bootm_mapsize" will override the value of
3877 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3878 then the value in "bootm_size" will be used instead.
3880 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3881 Enable initrd_high functionality. If defined then the
3882 initrd_high feature is enabled and the bootm ramdisk subcommand
3885 - CONFIG_SYS_BOOT_GET_CMDLINE:
3886 Enables allocating and saving kernel cmdline in space between
3887 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3889 - CONFIG_SYS_BOOT_GET_KBD:
3890 Enables allocating and saving a kernel copy of the bd_info in
3891 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3893 - CONFIG_SYS_MAX_FLASH_BANKS:
3894 Max number of Flash memory banks
3896 - CONFIG_SYS_MAX_FLASH_SECT:
3897 Max number of sectors on a Flash chip
3899 - CONFIG_SYS_FLASH_ERASE_TOUT:
3900 Timeout for Flash erase operations (in ms)
3902 - CONFIG_SYS_FLASH_WRITE_TOUT:
3903 Timeout for Flash write operations (in ms)
3905 - CONFIG_SYS_FLASH_LOCK_TOUT
3906 Timeout for Flash set sector lock bit operation (in ms)
3908 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3909 Timeout for Flash clear lock bits operation (in ms)
3911 - CONFIG_SYS_FLASH_PROTECTION
3912 If defined, hardware flash sectors protection is used
3913 instead of U-Boot software protection.
3915 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3917 Enable TFTP transfers directly to flash memory;
3918 without this option such a download has to be
3919 performed in two steps: (1) download to RAM, and (2)
3920 copy from RAM to flash.
3922 The two-step approach is usually more reliable, since
3923 you can check if the download worked before you erase
3924 the flash, but in some situations (when system RAM is
3925 too limited to allow for a temporary copy of the
3926 downloaded image) this option may be very useful.
3928 - CONFIG_SYS_FLASH_CFI:
3929 Define if the flash driver uses extra elements in the
3930 common flash structure for storing flash geometry.
3932 - CONFIG_FLASH_CFI_DRIVER
3933 This option also enables the building of the cfi_flash driver
3934 in the drivers directory
3936 - CONFIG_FLASH_CFI_MTD
3937 This option enables the building of the cfi_mtd driver
3938 in the drivers directory. The driver exports CFI flash
3941 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3942 Use buffered writes to flash.
3944 - CONFIG_FLASH_SPANSION_S29WS_N
3945 s29ws-n MirrorBit flash has non-standard addresses for buffered
3948 - CONFIG_SYS_FLASH_QUIET_TEST
3949 If this option is defined, the common CFI flash doesn't
3950 print it's warning upon not recognized FLASH banks. This
3951 is useful, if some of the configured banks are only
3952 optionally available.
3954 - CONFIG_FLASH_SHOW_PROGRESS
3955 If defined (must be an integer), print out countdown
3956 digits and dots. Recommended value: 45 (9..1) for 80
3957 column displays, 15 (3..1) for 40 column displays.
3959 - CONFIG_FLASH_VERIFY
3960 If defined, the content of the flash (destination) is compared
3961 against the source after the write operation. An error message
3962 will be printed when the contents are not identical.
3963 Please note that this option is useless in nearly all cases,
3964 since such flash programming errors usually are detected earlier
3965 while unprotecting/erasing/programming. Please only enable
3966 this option if you really know what you are doing.
3968 - CONFIG_SYS_RX_ETH_BUFFER:
3969 Defines the number of Ethernet receive buffers. On some
3970 Ethernet controllers it is recommended to set this value
3971 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3972 buffers can be full shortly after enabling the interface
3973 on high Ethernet traffic.
3974 Defaults to 4 if not defined.
3976 - CONFIG_ENV_MAX_ENTRIES
3978 Maximum number of entries in the hash table that is used
3979 internally to store the environment settings. The default
3980 setting is supposed to be generous and should work in most
3981 cases. This setting can be used to tune behaviour; see
3982 lib/hashtable.c for details.
3984 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3985 - CONFIG_ENV_FLAGS_LIST_STATIC
3986 Enable validation of the values given to environment variables when
3987 calling env set. Variables can be restricted to only decimal,
3988 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3989 the variables can also be restricted to IP address or MAC address.
3991 The format of the list is:
3992 type_attribute = [s|d|x|b|i|m]
3993 access_attribute = [a|r|o|c]
3994 attributes = type_attribute[access_attribute]
3995 entry = variable_name[:attributes]
3998 The type attributes are:
3999 s - String (default)
4002 b - Boolean ([1yYtT|0nNfF])
4006 The access attributes are:
4012 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4013 Define this to a list (string) to define the ".flags"
4014 environment variable in the default or embedded environment.
4016 - CONFIG_ENV_FLAGS_LIST_STATIC
4017 Define this to a list (string) to define validation that
4018 should be done if an entry is not found in the ".flags"
4019 environment variable. To override a setting in the static
4020 list, simply add an entry for the same variable name to the
4023 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4024 regular expression. This allows multiple variables to define the same
4025 flags without explicitly listing them for each variable.
4027 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4028 If defined, don't allow the -f switch to env set override variable
4031 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4032 This is set by OMAP boards for the max time that reset should
4033 be asserted. See doc/README.omap-reset-time for details on how
4034 the value can be calculated on a given board.
4037 If stdint.h is available with your toolchain you can define this
4038 option to enable it. You can provide option 'USE_STDINT=1' when
4039 building U-Boot to enable this.
4041 The following definitions that deal with the placement and management
4042 of environment data (variable area); in general, we support the
4043 following configurations:
4045 - CONFIG_BUILD_ENVCRC:
4047 Builds up envcrc with the target environment so that external utils
4048 may easily extract it and embed it in final U-Boot images.
4050 - CONFIG_ENV_IS_IN_FLASH:
4052 Define this if the environment is in flash memory.
4054 a) The environment occupies one whole flash sector, which is
4055 "embedded" in the text segment with the U-Boot code. This
4056 happens usually with "bottom boot sector" or "top boot
4057 sector" type flash chips, which have several smaller
4058 sectors at the start or the end. For instance, such a
4059 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4060 such a case you would place the environment in one of the
4061 4 kB sectors - with U-Boot code before and after it. With
4062 "top boot sector" type flash chips, you would put the
4063 environment in one of the last sectors, leaving a gap
4064 between U-Boot and the environment.
4066 - CONFIG_ENV_OFFSET:
4068 Offset of environment data (variable area) to the
4069 beginning of flash memory; for instance, with bottom boot
4070 type flash chips the second sector can be used: the offset
4071 for this sector is given here.
4073 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4077 This is just another way to specify the start address of
4078 the flash sector containing the environment (instead of
4081 - CONFIG_ENV_SECT_SIZE:
4083 Size of the sector containing the environment.
4086 b) Sometimes flash chips have few, equal sized, BIG sectors.
4087 In such a case you don't want to spend a whole sector for
4092 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4093 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4094 of this flash sector for the environment. This saves
4095 memory for the RAM copy of the environment.
4097 It may also save flash memory if you decide to use this
4098 when your environment is "embedded" within U-Boot code,
4099 since then the remainder of the flash sector could be used
4100 for U-Boot code. It should be pointed out that this is
4101 STRONGLY DISCOURAGED from a robustness point of view:
4102 updating the environment in flash makes it always
4103 necessary to erase the WHOLE sector. If something goes
4104 wrong before the contents has been restored from a copy in
4105 RAM, your target system will be dead.
4107 - CONFIG_ENV_ADDR_REDUND
4108 CONFIG_ENV_SIZE_REDUND
4110 These settings describe a second storage area used to hold
4111 a redundant copy of the environment data, so that there is
4112 a valid backup copy in case there is a power failure during
4113 a "saveenv" operation.
4115 BE CAREFUL! Any changes to the flash layout, and some changes to the
4116 source code will make it necessary to adapt <board>/u-boot.lds*
4120 - CONFIG_ENV_IS_IN_NVRAM:
4122 Define this if you have some non-volatile memory device
4123 (NVRAM, battery buffered SRAM) which you want to use for the
4129 These two #defines are used to determine the memory area you
4130 want to use for environment. It is assumed that this memory
4131 can just be read and written to, without any special
4134 BE CAREFUL! The first access to the environment happens quite early
4135 in U-Boot initialization (when we try to get the setting of for the
4136 console baudrate). You *MUST* have mapped your NVRAM area then, or
4139 Please note that even with NVRAM we still use a copy of the
4140 environment in RAM: we could work on NVRAM directly, but we want to
4141 keep settings there always unmodified except somebody uses "saveenv"
4142 to save the current settings.
4145 - CONFIG_ENV_IS_IN_EEPROM:
4147 Use this if you have an EEPROM or similar serial access
4148 device and a driver for it.
4150 - CONFIG_ENV_OFFSET:
4153 These two #defines specify the offset and size of the
4154 environment area within the total memory of your EEPROM.
4156 - CONFIG_SYS_I2C_EEPROM_ADDR:
4157 If defined, specified the chip address of the EEPROM device.
4158 The default address is zero.
4160 - CONFIG_SYS_I2C_EEPROM_BUS:
4161 If defined, specified the i2c bus of the EEPROM device.
4163 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4164 If defined, the number of bits used to address bytes in a
4165 single page in the EEPROM device. A 64 byte page, for example
4166 would require six bits.
4168 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4169 If defined, the number of milliseconds to delay between
4170 page writes. The default is zero milliseconds.
4172 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4173 The length in bytes of the EEPROM memory array address. Note
4174 that this is NOT the chip address length!
4176 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4177 EEPROM chips that implement "address overflow" are ones
4178 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4179 address and the extra bits end up in the "chip address" bit
4180 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4183 Note that we consider the length of the address field to
4184 still be one byte because the extra address bits are hidden
4185 in the chip address.
4187 - CONFIG_SYS_EEPROM_SIZE:
4188 The size in bytes of the EEPROM device.
4190 - CONFIG_ENV_EEPROM_IS_ON_I2C
4191 define this, if you have I2C and SPI activated, and your
4192 EEPROM, which holds the environment, is on the I2C bus.
4194 - CONFIG_I2C_ENV_EEPROM_BUS
4195 if you have an Environment on an EEPROM reached over
4196 I2C muxes, you can define here, how to reach this
4197 EEPROM. For example:
4199 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4201 EEPROM which holds the environment, is reached over
4202 a pca9547 i2c mux with address 0x70, channel 3.
4204 - CONFIG_ENV_IS_IN_DATAFLASH:
4206 Define this if you have a DataFlash memory device which you
4207 want to use for the environment.
4209 - CONFIG_ENV_OFFSET:
4213 These three #defines specify the offset and size of the
4214 environment area within the total memory of your DataFlash placed
4215 at the specified address.
4217 - CONFIG_ENV_IS_IN_SPI_FLASH:
4219 Define this if you have a SPI Flash memory device which you
4220 want to use for the environment.
4222 - CONFIG_ENV_OFFSET:
4225 These two #defines specify the offset and size of the
4226 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4227 aligned to an erase sector boundary.
4229 - CONFIG_ENV_SECT_SIZE:
4231 Define the SPI flash's sector size.
4233 - CONFIG_ENV_OFFSET_REDUND (optional):
4235 This setting describes a second storage area of CONFIG_ENV_SIZE
4236 size used to hold a redundant copy of the environment data, so
4237 that there is a valid backup copy in case there is a power failure
4238 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4239 aligned to an erase sector boundary.
4241 - CONFIG_ENV_SPI_BUS (optional):
4242 - CONFIG_ENV_SPI_CS (optional):
4244 Define the SPI bus and chip select. If not defined they will be 0.
4246 - CONFIG_ENV_SPI_MAX_HZ (optional):
4248 Define the SPI max work clock. If not defined then use 1MHz.
4250 - CONFIG_ENV_SPI_MODE (optional):
4252 Define the SPI work mode. If not defined then use SPI_MODE_3.
4254 - CONFIG_ENV_IS_IN_REMOTE:
4256 Define this if you have a remote memory space which you
4257 want to use for the local device's environment.
4262 These two #defines specify the address and size of the
4263 environment area within the remote memory space. The
4264 local device can get the environment from remote memory
4265 space by SRIO or PCIE links.
4267 BE CAREFUL! For some special cases, the local device can not use
4268 "saveenv" command. For example, the local device will get the
4269 environment stored in a remote NOR flash by SRIO or PCIE link,
4270 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4272 - CONFIG_ENV_IS_IN_NAND:
4274 Define this if you have a NAND device which you want to use
4275 for the environment.
4277 - CONFIG_ENV_OFFSET:
4280 These two #defines specify the offset and size of the environment
4281 area within the first NAND device. CONFIG_ENV_OFFSET must be
4282 aligned to an erase block boundary.
4284 - CONFIG_ENV_OFFSET_REDUND (optional):
4286 This setting describes a second storage area of CONFIG_ENV_SIZE
4287 size used to hold a redundant copy of the environment data, so
4288 that there is a valid backup copy in case there is a power failure
4289 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4290 aligned to an erase block boundary.
4292 - CONFIG_ENV_RANGE (optional):
4294 Specifies the length of the region in which the environment
4295 can be written. This should be a multiple of the NAND device's
4296 block size. Specifying a range with more erase blocks than
4297 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4298 the range to be avoided.
4300 - CONFIG_ENV_OFFSET_OOB (optional):
4302 Enables support for dynamically retrieving the offset of the
4303 environment from block zero's out-of-band data. The
4304 "nand env.oob" command can be used to record this offset.
4305 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4306 using CONFIG_ENV_OFFSET_OOB.
4308 - CONFIG_NAND_ENV_DST
4310 Defines address in RAM to which the nand_spl code should copy the
4311 environment. If redundant environment is used, it will be copied to
4312 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4314 - CONFIG_ENV_IS_IN_UBI:
4316 Define this if you have an UBI volume that you want to use for the
4317 environment. This has the benefit of wear-leveling the environment
4318 accesses, which is important on NAND.
4320 - CONFIG_ENV_UBI_PART:
4322 Define this to a string that is the mtd partition containing the UBI.
4324 - CONFIG_ENV_UBI_VOLUME:
4326 Define this to the name of the volume that you want to store the
4329 - CONFIG_ENV_UBI_VOLUME_REDUND:
4331 Define this to the name of another volume to store a second copy of
4332 the environment in. This will enable redundant environments in UBI.
4333 It is assumed that both volumes are in the same MTD partition.
4335 - CONFIG_UBI_SILENCE_MSG
4336 - CONFIG_UBIFS_SILENCE_MSG
4338 You will probably want to define these to avoid a really noisy system
4339 when storing the env in UBI.
4341 - CONFIG_ENV_IS_IN_FAT:
4342 Define this if you want to use the FAT file system for the environment.
4344 - FAT_ENV_INTERFACE:
4346 Define this to a string that is the name of the block device.
4348 - FAT_ENV_DEV_AND_PART:
4350 Define this to a string to specify the partition of the device. It can
4353 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4354 - "D:P": device D partition P. Error occurs if device D has no
4357 - "D" or "D:": device D partition 1 if device D has partition
4358 table, or the whole device D if has no partition
4360 - "D:auto": first partition in device D with bootable flag set.
4361 If none, first valid partition in device D. If no
4362 partition table then means device D.
4366 It's a string of the FAT file name. This file use to store the
4370 This should be defined. Otherwise it cannot save the environment file.
4372 - CONFIG_ENV_IS_IN_MMC:
4374 Define this if you have an MMC device which you want to use for the
4377 - CONFIG_SYS_MMC_ENV_DEV:
4379 Specifies which MMC device the environment is stored in.
4381 - CONFIG_SYS_MMC_ENV_PART (optional):
4383 Specifies which MMC partition the environment is stored in. If not
4384 set, defaults to partition 0, the user area. Common values might be
4385 1 (first MMC boot partition), 2 (second MMC boot partition).
4387 - CONFIG_ENV_OFFSET:
4390 These two #defines specify the offset and size of the environment
4391 area within the specified MMC device.
4393 If offset is positive (the usual case), it is treated as relative to
4394 the start of the MMC partition. If offset is negative, it is treated
4395 as relative to the end of the MMC partition. This can be useful if
4396 your board may be fitted with different MMC devices, which have
4397 different sizes for the MMC partitions, and you always want the
4398 environment placed at the very end of the partition, to leave the
4399 maximum possible space before it, to store other data.
4401 These two values are in units of bytes, but must be aligned to an
4402 MMC sector boundary.
4404 - CONFIG_ENV_OFFSET_REDUND (optional):
4406 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4407 hold a redundant copy of the environment data. This provides a
4408 valid backup copy in case the other copy is corrupted, e.g. due
4409 to a power failure during a "saveenv" operation.
4411 This value may also be positive or negative; this is handled in the
4412 same way as CONFIG_ENV_OFFSET.
4414 This value is also in units of bytes, but must also be aligned to
4415 an MMC sector boundary.
4417 - CONFIG_ENV_SIZE_REDUND (optional):
4419 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4420 set. If this value is set, it must be set to the same value as
4423 - CONFIG_SYS_SPI_INIT_OFFSET
4425 Defines offset to the initial SPI buffer area in DPRAM. The
4426 area is used at an early stage (ROM part) if the environment
4427 is configured to reside in the SPI EEPROM: We need a 520 byte
4428 scratch DPRAM area. It is used between the two initialization
4429 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4430 to be a good choice since it makes it far enough from the
4431 start of the data area as well as from the stack pointer.
4433 Please note that the environment is read-only until the monitor
4434 has been relocated to RAM and a RAM copy of the environment has been
4435 created; also, when using EEPROM you will have to use getenv_f()
4436 until then to read environment variables.
4438 The environment is protected by a CRC32 checksum. Before the monitor
4439 is relocated into RAM, as a result of a bad CRC you will be working
4440 with the compiled-in default environment - *silently*!!! [This is
4441 necessary, because the first environment variable we need is the
4442 "baudrate" setting for the console - if we have a bad CRC, we don't
4443 have any device yet where we could complain.]
4445 Note: once the monitor has been relocated, then it will complain if
4446 the default environment is used; a new CRC is computed as soon as you
4447 use the "saveenv" command to store a valid environment.
4449 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4450 Echo the inverted Ethernet link state to the fault LED.
4452 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4453 also needs to be defined.
4455 - CONFIG_SYS_FAULT_MII_ADDR:
4456 MII address of the PHY to check for the Ethernet link state.
4458 - CONFIG_NS16550_MIN_FUNCTIONS:
4459 Define this if you desire to only have use of the NS16550_init
4460 and NS16550_putc functions for the serial driver located at
4461 drivers/serial/ns16550.c. This option is useful for saving
4462 space for already greatly restricted images, including but not
4463 limited to NAND_SPL configurations.
4465 - CONFIG_DISPLAY_BOARDINFO
4466 Display information about the board that U-Boot is running on
4467 when U-Boot starts up. The board function checkboard() is called
4470 - CONFIG_DISPLAY_BOARDINFO_LATE
4471 Similar to the previous option, but display this information
4472 later, once stdio is running and output goes to the LCD, if
4475 - CONFIG_BOARD_SIZE_LIMIT:
4476 Maximum size of the U-Boot image. When defined, the
4477 build system checks that the actual size does not
4480 Low Level (hardware related) configuration options:
4481 ---------------------------------------------------
4483 - CONFIG_SYS_CACHELINE_SIZE:
4484 Cache Line Size of the CPU.
4486 - CONFIG_SYS_DEFAULT_IMMR:
4487 Default address of the IMMR after system reset.
4489 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4490 and RPXsuper) to be able to adjust the position of
4491 the IMMR register after a reset.
4493 - CONFIG_SYS_CCSRBAR_DEFAULT:
4494 Default (power-on reset) physical address of CCSR on Freescale
4497 - CONFIG_SYS_CCSRBAR:
4498 Virtual address of CCSR. On a 32-bit build, this is typically
4499 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4501 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4502 for cross-platform code that uses that macro instead.
4504 - CONFIG_SYS_CCSRBAR_PHYS:
4505 Physical address of CCSR. CCSR can be relocated to a new
4506 physical address, if desired. In this case, this macro should
4507 be set to that address. Otherwise, it should be set to the
4508 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4509 is typically relocated on 36-bit builds. It is recommended
4510 that this macro be defined via the _HIGH and _LOW macros:
4512 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4513 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4515 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4516 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4517 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4518 used in assembly code, so it must not contain typecasts or
4519 integer size suffixes (e.g. "ULL").
4521 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4522 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4523 used in assembly code, so it must not contain typecasts or
4524 integer size suffixes (e.g. "ULL").
4526 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4527 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4528 forced to a value that ensures that CCSR is not relocated.
4530 - Floppy Disk Support:
4531 CONFIG_SYS_FDC_DRIVE_NUMBER
4533 the default drive number (default value 0)
4535 CONFIG_SYS_ISA_IO_STRIDE
4537 defines the spacing between FDC chipset registers
4540 CONFIG_SYS_ISA_IO_OFFSET
4542 defines the offset of register from address. It
4543 depends on which part of the data bus is connected to
4544 the FDC chipset. (default value 0)
4546 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4547 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4550 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4551 fdc_hw_init() is called at the beginning of the FDC
4552 setup. fdc_hw_init() must be provided by the board
4553 source code. It is used to make hardware-dependent
4557 Most IDE controllers were designed to be connected with PCI
4558 interface. Only few of them were designed for AHB interface.
4559 When software is doing ATA command and data transfer to
4560 IDE devices through IDE-AHB controller, some additional
4561 registers accessing to these kind of IDE-AHB controller
4564 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4565 DO NOT CHANGE unless you know exactly what you're
4566 doing! (11-4) [MPC8xx/82xx systems only]
4568 - CONFIG_SYS_INIT_RAM_ADDR:
4570 Start address of memory area that can be used for
4571 initial data and stack; please note that this must be
4572 writable memory that is working WITHOUT special
4573 initialization, i. e. you CANNOT use normal RAM which
4574 will become available only after programming the
4575 memory controller and running certain initialization
4578 U-Boot uses the following memory types:
4579 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4580 - MPC824X: data cache
4581 - PPC4xx: data cache
4583 - CONFIG_SYS_GBL_DATA_OFFSET:
4585 Offset of the initial data structure in the memory
4586 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4587 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4588 data is located at the end of the available space
4589 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4590 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4591 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4592 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4595 On the MPC824X (or other systems that use the data
4596 cache for initial memory) the address chosen for
4597 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4598 point to an otherwise UNUSED address space between
4599 the top of RAM and the start of the PCI space.
4601 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4603 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4605 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4607 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4609 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4611 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4613 - CONFIG_SYS_OR_TIMING_SDRAM:
4616 - CONFIG_SYS_MAMR_PTA:
4617 periodic timer for refresh
4619 - CONFIG_SYS_DER: Debug Event Register (37-47)
4621 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4622 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4623 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4624 CONFIG_SYS_BR1_PRELIM:
4625 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4627 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4628 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4629 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4630 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4632 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4633 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4634 Machine Mode Register and Memory Periodic Timer
4635 Prescaler definitions (SDRAM timing)
4637 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4638 enable I2C microcode relocation patch (MPC8xx);
4639 define relocation offset in DPRAM [DSP2]
4641 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4642 enable SMC microcode relocation patch (MPC8xx);
4643 define relocation offset in DPRAM [SMC1]
4645 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4646 enable SPI microcode relocation patch (MPC8xx);
4647 define relocation offset in DPRAM [SCC4]
4649 - CONFIG_SYS_USE_OSCCLK:
4650 Use OSCM clock mode on MBX8xx board. Be careful,
4651 wrong setting might damage your board. Read
4652 doc/README.MBX before setting this variable!
4654 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4655 Offset of the bootmode word in DPRAM used by post
4656 (Power On Self Tests). This definition overrides
4657 #define'd default value in commproc.h resp.
4660 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4661 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4662 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4663 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4664 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4665 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4666 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4667 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4668 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4670 - CONFIG_PCI_DISABLE_PCIE:
4671 Disable PCI-Express on systems where it is supported but not
4674 - CONFIG_PCI_ENUM_ONLY
4675 Only scan through and get the devices on the buses.
4676 Don't do any setup work, presumably because someone or
4677 something has already done it, and we don't need to do it
4678 a second time. Useful for platforms that are pre-booted
4679 by coreboot or similar.
4681 - CONFIG_PCI_INDIRECT_BRIDGE:
4682 Enable support for indirect PCI bridges.
4685 Chip has SRIO or not
4688 Board has SRIO 1 port available
4691 Board has SRIO 2 port available
4693 - CONFIG_SRIO_PCIE_BOOT_MASTER
4694 Board can support master function for Boot from SRIO and PCIE
4696 - CONFIG_SYS_SRIOn_MEM_VIRT:
4697 Virtual Address of SRIO port 'n' memory region
4699 - CONFIG_SYS_SRIOn_MEM_PHYS:
4700 Physical Address of SRIO port 'n' memory region
4702 - CONFIG_SYS_SRIOn_MEM_SIZE:
4703 Size of SRIO port 'n' memory region
4705 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4706 Defined to tell the NAND controller that the NAND chip is using
4708 Not all NAND drivers use this symbol.
4709 Example of drivers that use it:
4710 - drivers/mtd/nand/ndfc.c
4711 - drivers/mtd/nand/mxc_nand.c
4713 - CONFIG_SYS_NDFC_EBC0_CFG
4714 Sets the EBC0_CFG register for the NDFC. If not defined
4715 a default value will be used.
4718 Get DDR timing information from an I2C EEPROM. Common
4719 with pluggable memory modules such as SODIMMs
4722 I2C address of the SPD EEPROM
4724 - CONFIG_SYS_SPD_BUS_NUM
4725 If SPD EEPROM is on an I2C bus other than the first
4726 one, specify here. Note that the value must resolve
4727 to something your driver can deal with.
4729 - CONFIG_SYS_DDR_RAW_TIMING
4730 Get DDR timing information from other than SPD. Common with
4731 soldered DDR chips onboard without SPD. DDR raw timing
4732 parameters are extracted from datasheet and hard-coded into
4733 header files or board specific files.
4735 - CONFIG_FSL_DDR_INTERACTIVE
4736 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4738 - CONFIG_FSL_DDR_SYNC_REFRESH
4739 Enable sync of refresh for multiple controllers.
4741 - CONFIG_FSL_DDR_BIST
4742 Enable built-in memory test for Freescale DDR controllers.
4744 - CONFIG_SYS_83XX_DDR_USES_CS0
4745 Only for 83xx systems. If specified, then DDR should
4746 be configured using CS0 and CS1 instead of CS2 and CS3.
4748 - CONFIG_ETHER_ON_FEC[12]
4749 Define to enable FEC[12] on a 8xx series processor.
4751 - CONFIG_FEC[12]_PHY
4752 Define to the hardcoded PHY address which corresponds
4753 to the given FEC; i. e.
4754 #define CONFIG_FEC1_PHY 4
4755 means that the PHY with address 4 is connected to FEC1
4757 When set to -1, means to probe for first available.
4759 - CONFIG_FEC[12]_PHY_NORXERR
4760 The PHY does not have a RXERR line (RMII only).
4761 (so program the FEC to ignore it).
4764 Enable RMII mode for all FECs.
4765 Note that this is a global option, we can't
4766 have one FEC in standard MII mode and another in RMII mode.
4768 - CONFIG_CRC32_VERIFY
4769 Add a verify option to the crc32 command.
4772 => crc32 -v <address> <count> <crc32>
4774 Where address/count indicate a memory area
4775 and crc32 is the correct crc32 which the
4779 Add the "loopw" memory command. This only takes effect if
4780 the memory commands are activated globally (CONFIG_CMD_MEM).
4783 Add the "mdc" and "mwc" memory commands. These are cyclic
4788 This command will print 4 bytes (10,11,12,13) each 500 ms.
4790 => mwc.l 100 12345678 10
4791 This command will write 12345678 to address 100 all 10 ms.
4793 This only takes effect if the memory commands are activated
4794 globally (CONFIG_CMD_MEM).
4796 - CONFIG_SKIP_LOWLEVEL_INIT
4797 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4798 low level initializations (like setting up the memory
4799 controller) are omitted and/or U-Boot does not
4800 relocate itself into RAM.
4802 Normally this variable MUST NOT be defined. The only
4803 exception is when U-Boot is loaded (to RAM) by some
4804 other boot loader or by a debugger which performs
4805 these initializations itself.
4807 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4808 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4809 to be skipped. The normal CPU15 init (such as enabling the
4810 instruction cache) is still performed.
4813 Modifies the behaviour of start.S when compiling a loader
4814 that is executed before the actual U-Boot. E.g. when
4815 compiling a NAND SPL.
4818 Modifies the behaviour of start.S when compiling a loader
4819 that is executed after the SPL and before the actual U-Boot.
4820 It is loaded by the SPL.
4822 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4823 Only for 85xx systems. If this variable is specified, the section
4824 .resetvec is not kept and the section .bootpg is placed in the
4825 previous 4k of the .text section.
4827 - CONFIG_ARCH_MAP_SYSMEM
4828 Generally U-Boot (and in particular the md command) uses
4829 effective address. It is therefore not necessary to regard
4830 U-Boot address as virtual addresses that need to be translated
4831 to physical addresses. However, sandbox requires this, since
4832 it maintains its own little RAM buffer which contains all
4833 addressable memory. This option causes some memory accesses
4834 to be mapped through map_sysmem() / unmap_sysmem().
4836 - CONFIG_USE_ARCH_MEMCPY
4837 CONFIG_USE_ARCH_MEMSET
4838 If these options are used a optimized version of memcpy/memset will
4839 be used if available. These functions may be faster under some
4840 conditions but may increase the binary size.
4842 - CONFIG_X86_RESET_VECTOR
4843 If defined, the x86 reset vector code is included. This is not
4844 needed when U-Boot is running from Coreboot.
4847 Defines the MPU clock speed (in MHz).
4849 NOTE : currently only supported on AM335x platforms.
4851 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4852 Enables the RTC32K OSC on AM33xx based plattforms
4854 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4855 Option to disable subpage write in NAND driver
4856 driver that uses this:
4857 drivers/mtd/nand/davinci_nand.c
4859 Freescale QE/FMAN Firmware Support:
4860 -----------------------------------
4862 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4863 loading of "firmware", which is encoded in the QE firmware binary format.
4864 This firmware often needs to be loaded during U-Boot booting, so macros
4865 are used to identify the storage device (NOR flash, SPI, etc) and the address
4868 - CONFIG_SYS_FMAN_FW_ADDR
4869 The address in the storage device where the FMAN microcode is located. The
4870 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4873 - CONFIG_SYS_QE_FW_ADDR
4874 The address in the storage device where the QE microcode is located. The
4875 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4878 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4879 The maximum possible size of the firmware. The firmware binary format
4880 has a field that specifies the actual size of the firmware, but it
4881 might not be possible to read any part of the firmware unless some
4882 local storage is allocated to hold the entire firmware first.
4884 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4885 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4886 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4887 virtual address in NOR flash.
4889 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4890 Specifies that QE/FMAN firmware is located in NAND flash.
4891 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4893 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4894 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4895 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4897 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4898 Specifies that QE/FMAN firmware is located on the primary SPI
4899 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4901 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4902 Specifies that QE/FMAN firmware is located in the remote (master)
4903 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4904 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4905 window->master inbound window->master LAW->the ucode address in
4906 master's memory space.
4908 Freescale Layerscape Management Complex Firmware Support:
4909 ---------------------------------------------------------
4910 The Freescale Layerscape Management Complex (MC) supports the loading of
4912 This firmware often needs to be loaded during U-Boot booting, so macros
4913 are used to identify the storage device (NOR flash, SPI, etc) and the address
4916 - CONFIG_FSL_MC_ENET
4917 Enable the MC driver for Layerscape SoCs.
4919 - CONFIG_SYS_LS_MC_FW_ADDR
4920 The address in the storage device where the firmware is located. The
4921 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4924 - CONFIG_SYS_LS_MC_FW_LENGTH
4925 The maximum possible size of the firmware. The firmware binary format
4926 has a field that specifies the actual size of the firmware, but it
4927 might not be possible to read any part of the firmware unless some
4928 local storage is allocated to hold the entire firmware first.
4930 - CONFIG_SYS_LS_MC_FW_IN_NOR
4931 Specifies that MC firmware is located in NOR flash, mapped as
4932 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4933 virtual address in NOR flash.
4935 Freescale Layerscape Debug Server Support:
4936 -------------------------------------------
4937 The Freescale Layerscape Debug Server Support supports the loading of
4938 "Debug Server firmware" and triggering SP boot-rom.
4939 This firmware often needs to be loaded during U-Boot booting.
4941 - CONFIG_FSL_DEBUG_SERVER
4942 Enable the Debug Server for Layerscape SoCs.
4944 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
4945 Define minimum DDR size required for debug server image
4947 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4948 Define alignment of reserved memory MC requires
4953 In order to achieve reproducible builds, timestamps used in the U-Boot build
4954 process have to be set to a fixed value.
4956 This is done using the SOURCE_DATE_EPOCH environment variable.
4957 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4958 option for U-Boot or an environment variable in U-Boot.
4960 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4962 Building the Software:
4963 ======================
4965 Building U-Boot has been tested in several native build environments
4966 and in many different cross environments. Of course we cannot support
4967 all possibly existing versions of cross development tools in all
4968 (potentially obsolete) versions. In case of tool chain problems we
4969 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4970 which is extensively used to build and test U-Boot.
4972 If you are not using a native environment, it is assumed that you
4973 have GNU cross compiling tools available in your path. In this case,
4974 you must set the environment variable CROSS_COMPILE in your shell.
4975 Note that no changes to the Makefile or any other source files are
4976 necessary. For example using the ELDK on a 4xx CPU, please enter:
4978 $ CROSS_COMPILE=ppc_4xx-
4979 $ export CROSS_COMPILE
4981 Note: If you wish to generate Windows versions of the utilities in
4982 the tools directory you can use the MinGW toolchain
4983 (http://www.mingw.org). Set your HOST tools to the MinGW
4984 toolchain and execute 'make tools'. For example:
4986 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4988 Binaries such as tools/mkimage.exe will be created which can
4989 be executed on computers running Windows.
4991 U-Boot is intended to be simple to build. After installing the
4992 sources you must configure U-Boot for one specific board type. This
4997 where "NAME_defconfig" is the name of one of the existing configu-
4998 rations; see boards.cfg for supported names.
5000 Note: for some board special configuration names may exist; check if
5001 additional information is available from the board vendor; for
5002 instance, the TQM823L systems are available without (standard)
5003 or with LCD support. You can select such additional "features"
5004 when choosing the configuration, i. e.
5006 make TQM823L_defconfig
5007 - will configure for a plain TQM823L, i. e. no LCD support
5009 make TQM823L_LCD_defconfig
5010 - will configure for a TQM823L with U-Boot console on LCD
5015 Finally, type "make all", and you should get some working U-Boot
5016 images ready for download to / installation on your system:
5018 - "u-boot.bin" is a raw binary image
5019 - "u-boot" is an image in ELF binary format
5020 - "u-boot.srec" is in Motorola S-Record format
5022 By default the build is performed locally and the objects are saved
5023 in the source directory. One of the two methods can be used to change
5024 this behavior and build U-Boot to some external directory:
5026 1. Add O= to the make command line invocations:
5028 make O=/tmp/build distclean
5029 make O=/tmp/build NAME_defconfig
5030 make O=/tmp/build all
5032 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5034 export KBUILD_OUTPUT=/tmp/build
5039 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5043 Please be aware that the Makefiles assume you are using GNU make, so
5044 for instance on NetBSD you might need to use "gmake" instead of
5048 If the system board that you have is not listed, then you will need
5049 to port U-Boot to your hardware platform. To do this, follow these
5052 1. Create a new directory to hold your board specific code. Add any
5053 files you need. In your board directory, you will need at least
5054 the "Makefile" and a "<board>.c".
5055 2. Create a new configuration file "include/configs/<board>.h" for
5057 3. If you're porting U-Boot to a new CPU, then also create a new
5058 directory to hold your CPU specific code. Add any files you need.
5059 4. Run "make <board>_defconfig" with your new name.
5060 5. Type "make", and you should get a working "u-boot.srec" file
5061 to be installed on your target system.
5062 6. Debug and solve any problems that might arise.
5063 [Of course, this last step is much harder than it sounds.]
5066 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5067 ==============================================================
5069 If you have modified U-Boot sources (for instance added a new board
5070 or support for new devices, a new CPU, etc.) you are expected to
5071 provide feedback to the other developers. The feedback normally takes
5072 the form of a "patch", i. e. a context diff against a certain (latest
5073 official or latest in the git repository) version of U-Boot sources.
5075 But before you submit such a patch, please verify that your modifi-
5076 cation did not break existing code. At least make sure that *ALL* of
5077 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5078 just run the "MAKEALL" script, which will configure and build U-Boot
5079 for ALL supported system. Be warned, this will take a while. You can
5080 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5081 environment variable to the script, i. e. to use the ELDK cross tools
5084 CROSS_COMPILE=ppc_8xx- MAKEALL
5086 or to build on a native PowerPC system you can type
5088 CROSS_COMPILE=' ' MAKEALL
5090 When using the MAKEALL script, the default behaviour is to build
5091 U-Boot in the source directory. This location can be changed by
5092 setting the BUILD_DIR environment variable. Also, for each target
5093 built, the MAKEALL script saves two log files (<target>.ERR and
5094 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5095 location can be changed by setting the MAKEALL_LOGDIR environment
5096 variable. For example:
5098 export BUILD_DIR=/tmp/build
5099 export MAKEALL_LOGDIR=/tmp/log
5100 CROSS_COMPILE=ppc_8xx- MAKEALL
5102 With the above settings build objects are saved in the /tmp/build,
5103 log files are saved in the /tmp/log and the source tree remains clean
5104 during the whole build process.
5107 See also "U-Boot Porting Guide" below.
5110 Monitor Commands - Overview:
5111 ============================
5113 go - start application at address 'addr'
5114 run - run commands in an environment variable
5115 bootm - boot application image from memory
5116 bootp - boot image via network using BootP/TFTP protocol
5117 bootz - boot zImage from memory
5118 tftpboot- boot image via network using TFTP protocol
5119 and env variables "ipaddr" and "serverip"
5120 (and eventually "gatewayip")
5121 tftpput - upload a file via network using TFTP protocol
5122 rarpboot- boot image via network using RARP/TFTP protocol
5123 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5124 loads - load S-Record file over serial line
5125 loadb - load binary file over serial line (kermit mode)
5127 mm - memory modify (auto-incrementing)
5128 nm - memory modify (constant address)
5129 mw - memory write (fill)
5131 cmp - memory compare
5132 crc32 - checksum calculation
5133 i2c - I2C sub-system
5134 sspi - SPI utility commands
5135 base - print or set address offset
5136 printenv- print environment variables
5137 setenv - set environment variables
5138 saveenv - save environment variables to persistent storage
5139 protect - enable or disable FLASH write protection
5140 erase - erase FLASH memory
5141 flinfo - print FLASH memory information
5142 nand - NAND memory operations (see doc/README.nand)
5143 bdinfo - print Board Info structure
5144 iminfo - print header information for application image
5145 coninfo - print console devices and informations
5146 ide - IDE sub-system
5147 loop - infinite loop on address range
5148 loopw - infinite write loop on address range
5149 mtest - simple RAM test
5150 icache - enable or disable instruction cache
5151 dcache - enable or disable data cache
5152 reset - Perform RESET of the CPU
5153 echo - echo args to console
5154 version - print monitor version
5155 help - print online help
5156 ? - alias for 'help'
5159 Monitor Commands - Detailed Description:
5160 ========================================
5164 For now: just type "help <command>".
5167 Environment Variables:
5168 ======================
5170 U-Boot supports user configuration using Environment Variables which
5171 can be made persistent by saving to Flash memory.
5173 Environment Variables are set using "setenv", printed using
5174 "printenv", and saved to Flash using "saveenv". Using "setenv"
5175 without a value can be used to delete a variable from the
5176 environment. As long as you don't save the environment you are
5177 working with an in-memory copy. In case the Flash area containing the
5178 environment is erased by accident, a default environment is provided.
5180 Some configuration options can be set using Environment Variables.
5182 List of environment variables (most likely not complete):
5184 baudrate - see CONFIG_BAUDRATE
5186 bootdelay - see CONFIG_BOOTDELAY
5188 bootcmd - see CONFIG_BOOTCOMMAND
5190 bootargs - Boot arguments when booting an RTOS image
5192 bootfile - Name of the image to load with TFTP
5194 bootm_low - Memory range available for image processing in the bootm
5195 command can be restricted. This variable is given as
5196 a hexadecimal number and defines lowest address allowed
5197 for use by the bootm command. See also "bootm_size"
5198 environment variable. Address defined by "bootm_low" is
5199 also the base of the initial memory mapping for the Linux
5200 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5203 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5204 This variable is given as a hexadecimal number and it
5205 defines the size of the memory region starting at base
5206 address bootm_low that is accessible by the Linux kernel
5207 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5208 as the default value if it is defined, and bootm_size is
5211 bootm_size - Memory range available for image processing in the bootm
5212 command can be restricted. This variable is given as
5213 a hexadecimal number and defines the size of the region
5214 allowed for use by the bootm command. See also "bootm_low"
5215 environment variable.
5217 updatefile - Location of the software update file on a TFTP server, used
5218 by the automatic software update feature. Please refer to
5219 documentation in doc/README.update for more details.
5221 autoload - if set to "no" (any string beginning with 'n'),
5222 "bootp" will just load perform a lookup of the
5223 configuration from the BOOTP server, but not try to
5224 load any image using TFTP
5226 autostart - if set to "yes", an image loaded using the "bootp",
5227 "rarpboot", "tftpboot" or "diskboot" commands will
5228 be automatically started (by internally calling
5231 If set to "no", a standalone image passed to the
5232 "bootm" command will be copied to the load address
5233 (and eventually uncompressed), but NOT be started.
5234 This can be used to load and uncompress arbitrary
5237 fdt_high - if set this restricts the maximum address that the
5238 flattened device tree will be copied into upon boot.
5239 For example, if you have a system with 1 GB memory
5240 at physical address 0x10000000, while Linux kernel
5241 only recognizes the first 704 MB as low memory, you
5242 may need to set fdt_high as 0x3C000000 to have the
5243 device tree blob be copied to the maximum address
5244 of the 704 MB low memory, so that Linux kernel can
5245 access it during the boot procedure.
5247 If this is set to the special value 0xFFFFFFFF then
5248 the fdt will not be copied at all on boot. For this
5249 to work it must reside in writable memory, have
5250 sufficient padding on the end of it for u-boot to
5251 add the information it needs into it, and the memory
5252 must be accessible by the kernel.
5254 fdtcontroladdr- if set this is the address of the control flattened
5255 device tree used by U-Boot when CONFIG_OF_CONTROL is
5258 i2cfast - (PPC405GP|PPC405EP only)
5259 if set to 'y' configures Linux I2C driver for fast
5260 mode (400kHZ). This environment variable is used in
5261 initialization code. So, for changes to be effective
5262 it must be saved and board must be reset.
5264 initrd_high - restrict positioning of initrd images:
5265 If this variable is not set, initrd images will be
5266 copied to the highest possible address in RAM; this
5267 is usually what you want since it allows for
5268 maximum initrd size. If for some reason you want to
5269 make sure that the initrd image is loaded below the
5270 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5271 variable to a value of "no" or "off" or "0".
5272 Alternatively, you can set it to a maximum upper
5273 address to use (U-Boot will still check that it
5274 does not overwrite the U-Boot stack and data).
5276 For instance, when you have a system with 16 MB
5277 RAM, and want to reserve 4 MB from use by Linux,
5278 you can do this by adding "mem=12M" to the value of
5279 the "bootargs" variable. However, now you must make
5280 sure that the initrd image is placed in the first
5281 12 MB as well - this can be done with
5283 setenv initrd_high 00c00000
5285 If you set initrd_high to 0xFFFFFFFF, this is an
5286 indication to U-Boot that all addresses are legal
5287 for the Linux kernel, including addresses in flash
5288 memory. In this case U-Boot will NOT COPY the
5289 ramdisk at all. This may be useful to reduce the
5290 boot time on your system, but requires that this
5291 feature is supported by your Linux kernel.
5293 ipaddr - IP address; needed for tftpboot command
5295 loadaddr - Default load address for commands like "bootp",
5296 "rarpboot", "tftpboot", "loadb" or "diskboot"
5298 loads_echo - see CONFIG_LOADS_ECHO
5300 serverip - TFTP server IP address; needed for tftpboot command
5302 bootretry - see CONFIG_BOOT_RETRY_TIME
5304 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5306 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5308 ethprime - controls which interface is used first.
5310 ethact - controls which interface is currently active.
5311 For example you can do the following
5313 => setenv ethact FEC
5314 => ping 192.168.0.1 # traffic sent on FEC
5315 => setenv ethact SCC
5316 => ping 10.0.0.1 # traffic sent on SCC
5318 ethrotate - When set to "no" U-Boot does not go through all
5319 available network interfaces.
5320 It just stays at the currently selected interface.
5322 netretry - When set to "no" each network operation will
5323 either succeed or fail without retrying.
5324 When set to "once" the network operation will
5325 fail when all the available network interfaces
5326 are tried once without success.
5327 Useful on scripts which control the retry operation
5330 npe_ucode - set load address for the NPE microcode
5332 silent_linux - If set then Linux will be told to boot silently, by
5333 changing the console to be empty. If "yes" it will be
5334 made silent. If "no" it will not be made silent. If
5335 unset, then it will be made silent if the U-Boot console
5338 tftpsrcp - If this is set, the value is used for TFTP's
5341 tftpdstp - If this is set, the value is used for TFTP's UDP
5342 destination port instead of the Well Know Port 69.
5344 tftpblocksize - Block size to use for TFTP transfers; if not set,
5345 we use the TFTP server's default block size
5347 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5348 seconds, minimum value is 1000 = 1 second). Defines
5349 when a packet is considered to be lost so it has to
5350 be retransmitted. The default is 5000 = 5 seconds.
5351 Lowering this value may make downloads succeed
5352 faster in networks with high packet loss rates or
5353 with unreliable TFTP servers.
5355 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5356 unit, minimum value = 0). Defines how many timeouts
5357 can happen during a single file transfer before that
5358 transfer is aborted. The default is 10, and 0 means
5359 'no timeouts allowed'. Increasing this value may help
5360 downloads succeed with high packet loss rates, or with
5361 unreliable TFTP servers or client hardware.
5363 vlan - When set to a value < 4095 the traffic over
5364 Ethernet is encapsulated/received over 802.1q
5367 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5368 Unsigned value, in milliseconds. If not set, the period will
5369 be either the default (28000), or a value based on
5370 CONFIG_NET_RETRY_COUNT, if defined. This value has
5371 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5373 The following image location variables contain the location of images
5374 used in booting. The "Image" column gives the role of the image and is
5375 not an environment variable name. The other columns are environment
5376 variable names. "File Name" gives the name of the file on a TFTP
5377 server, "RAM Address" gives the location in RAM the image will be
5378 loaded to, and "Flash Location" gives the image's address in NOR
5379 flash or offset in NAND flash.
5381 *Note* - these variables don't have to be defined for all boards, some
5382 boards currently use other variables for these purposes, and some
5383 boards use these variables for other purposes.
5385 Image File Name RAM Address Flash Location
5386 ----- --------- ----------- --------------
5387 u-boot u-boot u-boot_addr_r u-boot_addr
5388 Linux kernel bootfile kernel_addr_r kernel_addr
5389 device tree blob fdtfile fdt_addr_r fdt_addr
5390 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5392 The following environment variables may be used and automatically
5393 updated by the network boot commands ("bootp" and "rarpboot"),
5394 depending the information provided by your boot server:
5396 bootfile - see above
5397 dnsip - IP address of your Domain Name Server
5398 dnsip2 - IP address of your secondary Domain Name Server
5399 gatewayip - IP address of the Gateway (Router) to use
5400 hostname - Target hostname
5402 netmask - Subnet Mask
5403 rootpath - Pathname of the root filesystem on the NFS server
5404 serverip - see above
5407 There are two special Environment Variables:
5409 serial# - contains hardware identification information such
5410 as type string and/or serial number
5411 ethaddr - Ethernet address
5413 These variables can be set only once (usually during manufacturing of
5414 the board). U-Boot refuses to delete or overwrite these variables
5415 once they have been set once.
5418 Further special Environment Variables:
5420 ver - Contains the U-Boot version string as printed
5421 with the "version" command. This variable is
5422 readonly (see CONFIG_VERSION_VARIABLE).
5425 Please note that changes to some configuration parameters may take
5426 only effect after the next boot (yes, that's just like Windoze :-).
5429 Callback functions for environment variables:
5430 ---------------------------------------------
5432 For some environment variables, the behavior of u-boot needs to change
5433 when their values are changed. This functionality allows functions to
5434 be associated with arbitrary variables. On creation, overwrite, or
5435 deletion, the callback will provide the opportunity for some side
5436 effect to happen or for the change to be rejected.
5438 The callbacks are named and associated with a function using the
5439 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5441 These callbacks are associated with variables in one of two ways. The
5442 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5443 in the board configuration to a string that defines a list of
5444 associations. The list must be in the following format:
5446 entry = variable_name[:callback_name]
5449 If the callback name is not specified, then the callback is deleted.
5450 Spaces are also allowed anywhere in the list.
5452 Callbacks can also be associated by defining the ".callbacks" variable
5453 with the same list format above. Any association in ".callbacks" will
5454 override any association in the static list. You can define
5455 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5456 ".callbacks" environment variable in the default or embedded environment.
5458 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5459 regular expression. This allows multiple variables to be connected to
5460 the same callback without explicitly listing them all out.
5463 Command Line Parsing:
5464 =====================
5466 There are two different command line parsers available with U-Boot:
5467 the old "simple" one, and the much more powerful "hush" shell:
5469 Old, simple command line parser:
5470 --------------------------------
5472 - supports environment variables (through setenv / saveenv commands)
5473 - several commands on one line, separated by ';'
5474 - variable substitution using "... ${name} ..." syntax
5475 - special characters ('$', ';') can be escaped by prefixing with '\',
5477 setenv bootcmd bootm \${address}
5478 - You can also escape text by enclosing in single apostrophes, for example:
5479 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5484 - similar to Bourne shell, with control structures like
5485 if...then...else...fi, for...do...done; while...do...done,
5486 until...do...done, ...
5487 - supports environment ("global") variables (through setenv / saveenv
5488 commands) and local shell variables (through standard shell syntax
5489 "name=value"); only environment variables can be used with "run"
5495 (1) If a command line (or an environment variable executed by a "run"
5496 command) contains several commands separated by semicolon, and
5497 one of these commands fails, then the remaining commands will be
5500 (2) If you execute several variables with one call to run (i. e.
5501 calling run with a list of variables as arguments), any failing
5502 command will cause "run" to terminate, i. e. the remaining
5503 variables are not executed.
5505 Note for Redundant Ethernet Interfaces:
5506 =======================================
5508 Some boards come with redundant Ethernet interfaces; U-Boot supports
5509 such configurations and is capable of automatic selection of a
5510 "working" interface when needed. MAC assignment works as follows:
5512 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5513 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5514 "eth1addr" (=>eth1), "eth2addr", ...
5516 If the network interface stores some valid MAC address (for instance
5517 in SROM), this is used as default address if there is NO correspon-
5518 ding setting in the environment; if the corresponding environment
5519 variable is set, this overrides the settings in the card; that means:
5521 o If the SROM has a valid MAC address, and there is no address in the
5522 environment, the SROM's address is used.
5524 o If there is no valid address in the SROM, and a definition in the
5525 environment exists, then the value from the environment variable is
5528 o If both the SROM and the environment contain a MAC address, and
5529 both addresses are the same, this MAC address is used.
5531 o If both the SROM and the environment contain a MAC address, and the
5532 addresses differ, the value from the environment is used and a
5535 o If neither SROM nor the environment contain a MAC address, an error
5536 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5537 a random, locally-assigned MAC is used.
5539 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5540 will be programmed into hardware as part of the initialization process. This
5541 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5542 The naming convention is as follows:
5543 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5548 U-Boot is capable of booting (and performing other auxiliary operations on)
5549 images in two formats:
5551 New uImage format (FIT)
5552 -----------------------
5554 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5555 to Flattened Device Tree). It allows the use of images with multiple
5556 components (several kernels, ramdisks, etc.), with contents protected by
5557 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5563 Old image format is based on binary files which can be basically anything,
5564 preceded by a special header; see the definitions in include/image.h for
5565 details; basically, the header defines the following image properties:
5567 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5568 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5569 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5570 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5572 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5573 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5574 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5575 * Compression Type (uncompressed, gzip, bzip2)
5581 The header is marked by a special Magic Number, and both the header
5582 and the data portions of the image are secured against corruption by
5589 Although U-Boot should support any OS or standalone application
5590 easily, the main focus has always been on Linux during the design of
5593 U-Boot includes many features that so far have been part of some
5594 special "boot loader" code within the Linux kernel. Also, any
5595 "initrd" images to be used are no longer part of one big Linux image;
5596 instead, kernel and "initrd" are separate images. This implementation
5597 serves several purposes:
5599 - the same features can be used for other OS or standalone
5600 applications (for instance: using compressed images to reduce the
5601 Flash memory footprint)
5603 - it becomes much easier to port new Linux kernel versions because
5604 lots of low-level, hardware dependent stuff are done by U-Boot
5606 - the same Linux kernel image can now be used with different "initrd"
5607 images; of course this also means that different kernel images can
5608 be run with the same "initrd". This makes testing easier (you don't
5609 have to build a new "zImage.initrd" Linux image when you just
5610 change a file in your "initrd"). Also, a field-upgrade of the
5611 software is easier now.
5617 Porting Linux to U-Boot based systems:
5618 ---------------------------------------
5620 U-Boot cannot save you from doing all the necessary modifications to
5621 configure the Linux device drivers for use with your target hardware
5622 (no, we don't intend to provide a full virtual machine interface to
5625 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5627 Just make sure your machine specific header file (for instance
5628 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5629 Information structure as we define in include/asm-<arch>/u-boot.h,
5630 and make sure that your definition of IMAP_ADDR uses the same value
5631 as your U-Boot configuration in CONFIG_SYS_IMMR.
5633 Note that U-Boot now has a driver model, a unified model for drivers.
5634 If you are adding a new driver, plumb it into driver model. If there
5635 is no uclass available, you are encouraged to create one. See
5639 Configuring the Linux kernel:
5640 -----------------------------
5642 No specific requirements for U-Boot. Make sure you have some root
5643 device (initial ramdisk, NFS) for your target system.
5646 Building a Linux Image:
5647 -----------------------
5649 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5650 not used. If you use recent kernel source, a new build target
5651 "uImage" will exist which automatically builds an image usable by
5652 U-Boot. Most older kernels also have support for a "pImage" target,
5653 which was introduced for our predecessor project PPCBoot and uses a
5654 100% compatible format.
5658 make TQM850L_defconfig
5663 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5664 encapsulate a compressed Linux kernel image with header information,
5665 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5667 * build a standard "vmlinux" kernel image (in ELF binary format):
5669 * convert the kernel into a raw binary image:
5671 ${CROSS_COMPILE}-objcopy -O binary \
5672 -R .note -R .comment \
5673 -S vmlinux linux.bin
5675 * compress the binary image:
5679 * package compressed binary image for U-Boot:
5681 mkimage -A ppc -O linux -T kernel -C gzip \
5682 -a 0 -e 0 -n "Linux Kernel Image" \
5683 -d linux.bin.gz uImage
5686 The "mkimage" tool can also be used to create ramdisk images for use
5687 with U-Boot, either separated from the Linux kernel image, or
5688 combined into one file. "mkimage" encapsulates the images with a 64
5689 byte header containing information about target architecture,
5690 operating system, image type, compression method, entry points, time
5691 stamp, CRC32 checksums, etc.
5693 "mkimage" can be called in two ways: to verify existing images and
5694 print the header information, or to build new images.
5696 In the first form (with "-l" option) mkimage lists the information
5697 contained in the header of an existing U-Boot image; this includes
5698 checksum verification:
5700 tools/mkimage -l image
5701 -l ==> list image header information
5703 The second form (with "-d" option) is used to build a U-Boot image
5704 from a "data file" which is used as image payload:
5706 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5707 -n name -d data_file image
5708 -A ==> set architecture to 'arch'
5709 -O ==> set operating system to 'os'
5710 -T ==> set image type to 'type'
5711 -C ==> set compression type 'comp'
5712 -a ==> set load address to 'addr' (hex)
5713 -e ==> set entry point to 'ep' (hex)
5714 -n ==> set image name to 'name'
5715 -d ==> use image data from 'datafile'
5717 Right now, all Linux kernels for PowerPC systems use the same load
5718 address (0x00000000), but the entry point address depends on the
5721 - 2.2.x kernels have the entry point at 0x0000000C,
5722 - 2.3.x and later kernels have the entry point at 0x00000000.
5724 So a typical call to build a U-Boot image would read:
5726 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5727 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5728 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5729 > examples/uImage.TQM850L
5730 Image Name: 2.4.4 kernel for TQM850L
5731 Created: Wed Jul 19 02:34:59 2000
5732 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5733 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5734 Load Address: 0x00000000
5735 Entry Point: 0x00000000
5737 To verify the contents of the image (or check for corruption):
5739 -> tools/mkimage -l examples/uImage.TQM850L
5740 Image Name: 2.4.4 kernel for TQM850L
5741 Created: Wed Jul 19 02:34:59 2000
5742 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5743 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5744 Load Address: 0x00000000
5745 Entry Point: 0x00000000
5747 NOTE: for embedded systems where boot time is critical you can trade
5748 speed for memory and install an UNCOMPRESSED image instead: this
5749 needs more space in Flash, but boots much faster since it does not
5750 need to be uncompressed:
5752 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5753 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5754 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5755 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5756 > examples/uImage.TQM850L-uncompressed
5757 Image Name: 2.4.4 kernel for TQM850L
5758 Created: Wed Jul 19 02:34:59 2000
5759 Image Type: PowerPC Linux Kernel Image (uncompressed)
5760 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5761 Load Address: 0x00000000
5762 Entry Point: 0x00000000
5765 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5766 when your kernel is intended to use an initial ramdisk:
5768 -> tools/mkimage -n 'Simple Ramdisk Image' \
5769 > -A ppc -O linux -T ramdisk -C gzip \
5770 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5771 Image Name: Simple Ramdisk Image
5772 Created: Wed Jan 12 14:01:50 2000
5773 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5774 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5775 Load Address: 0x00000000
5776 Entry Point: 0x00000000
5778 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5779 option performs the converse operation of the mkimage's second form (the "-d"
5780 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5783 tools/dumpimage -i image -T type -p position data_file
5784 -i ==> extract from the 'image' a specific 'data_file'
5785 -T ==> set image type to 'type'
5786 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5789 Installing a Linux Image:
5790 -------------------------
5792 To downloading a U-Boot image over the serial (console) interface,
5793 you must convert the image to S-Record format:
5795 objcopy -I binary -O srec examples/image examples/image.srec
5797 The 'objcopy' does not understand the information in the U-Boot
5798 image header, so the resulting S-Record file will be relative to
5799 address 0x00000000. To load it to a given address, you need to
5800 specify the target address as 'offset' parameter with the 'loads'
5803 Example: install the image to address 0x40100000 (which on the
5804 TQM8xxL is in the first Flash bank):
5806 => erase 40100000 401FFFFF
5812 ## Ready for S-Record download ...
5813 ~>examples/image.srec
5814 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5816 15989 15990 15991 15992
5817 [file transfer complete]
5819 ## Start Addr = 0x00000000
5822 You can check the success of the download using the 'iminfo' command;
5823 this includes a checksum verification so you can be sure no data
5824 corruption happened:
5828 ## Checking Image at 40100000 ...
5829 Image Name: 2.2.13 for initrd on TQM850L
5830 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5831 Data Size: 335725 Bytes = 327 kB = 0 MB
5832 Load Address: 00000000
5833 Entry Point: 0000000c
5834 Verifying Checksum ... OK
5840 The "bootm" command is used to boot an application that is stored in
5841 memory (RAM or Flash). In case of a Linux kernel image, the contents
5842 of the "bootargs" environment variable is passed to the kernel as
5843 parameters. You can check and modify this variable using the
5844 "printenv" and "setenv" commands:
5847 => printenv bootargs
5848 bootargs=root=/dev/ram
5850 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5852 => printenv bootargs
5853 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5856 ## Booting Linux kernel at 40020000 ...
5857 Image Name: 2.2.13 for NFS on TQM850L
5858 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5859 Data Size: 381681 Bytes = 372 kB = 0 MB
5860 Load Address: 00000000
5861 Entry Point: 0000000c
5862 Verifying Checksum ... OK
5863 Uncompressing Kernel Image ... OK
5864 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
5865 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5866 time_init: decrementer frequency = 187500000/60
5867 Calibrating delay loop... 49.77 BogoMIPS
5868 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5871 If you want to boot a Linux kernel with initial RAM disk, you pass
5872 the memory addresses of both the kernel and the initrd image (PPBCOOT
5873 format!) to the "bootm" command:
5875 => imi 40100000 40200000
5877 ## Checking Image at 40100000 ...
5878 Image Name: 2.2.13 for initrd on TQM850L
5879 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5880 Data Size: 335725 Bytes = 327 kB = 0 MB
5881 Load Address: 00000000
5882 Entry Point: 0000000c
5883 Verifying Checksum ... OK
5885 ## Checking Image at 40200000 ...
5886 Image Name: Simple Ramdisk Image
5887 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5888 Data Size: 566530 Bytes = 553 kB = 0 MB
5889 Load Address: 00000000
5890 Entry Point: 00000000
5891 Verifying Checksum ... OK
5893 => bootm 40100000 40200000
5894 ## Booting Linux kernel at 40100000 ...
5895 Image Name: 2.2.13 for initrd on TQM850L
5896 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5897 Data Size: 335725 Bytes = 327 kB = 0 MB
5898 Load Address: 00000000
5899 Entry Point: 0000000c
5900 Verifying Checksum ... OK
5901 Uncompressing Kernel Image ... OK
5902 ## Loading RAMDisk Image at 40200000 ...
5903 Image Name: Simple Ramdisk Image
5904 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5905 Data Size: 566530 Bytes = 553 kB = 0 MB
5906 Load Address: 00000000
5907 Entry Point: 00000000
5908 Verifying Checksum ... OK
5909 Loading Ramdisk ... OK
5910 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
5911 Boot arguments: root=/dev/ram
5912 time_init: decrementer frequency = 187500000/60
5913 Calibrating delay loop... 49.77 BogoMIPS
5915 RAMDISK: Compressed image found at block 0
5916 VFS: Mounted root (ext2 filesystem).
5920 Boot Linux and pass a flat device tree:
5923 First, U-Boot must be compiled with the appropriate defines. See the section
5924 titled "Linux Kernel Interface" above for a more in depth explanation. The
5925 following is an example of how to start a kernel and pass an updated
5931 oft=oftrees/mpc8540ads.dtb
5932 => tftp $oftaddr $oft
5933 Speed: 1000, full duplex
5935 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5936 Filename 'oftrees/mpc8540ads.dtb'.
5937 Load address: 0x300000
5940 Bytes transferred = 4106 (100a hex)
5941 => tftp $loadaddr $bootfile
5942 Speed: 1000, full duplex
5944 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5946 Load address: 0x200000
5947 Loading:############
5949 Bytes transferred = 1029407 (fb51f hex)
5954 => bootm $loadaddr - $oftaddr
5955 ## Booting image at 00200000 ...
5956 Image Name: Linux-2.6.17-dirty
5957 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5958 Data Size: 1029343 Bytes = 1005.2 kB
5959 Load Address: 00000000
5960 Entry Point: 00000000
5961 Verifying Checksum ... OK
5962 Uncompressing Kernel Image ... OK
5963 Booting using flat device tree at 0x300000
5964 Using MPC85xx ADS machine description
5965 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5969 More About U-Boot Image Types:
5970 ------------------------------
5972 U-Boot supports the following image types:
5974 "Standalone Programs" are directly runnable in the environment
5975 provided by U-Boot; it is expected that (if they behave
5976 well) you can continue to work in U-Boot after return from
5977 the Standalone Program.
5978 "OS Kernel Images" are usually images of some Embedded OS which
5979 will take over control completely. Usually these programs
5980 will install their own set of exception handlers, device
5981 drivers, set up the MMU, etc. - this means, that you cannot
5982 expect to re-enter U-Boot except by resetting the CPU.
5983 "RAMDisk Images" are more or less just data blocks, and their
5984 parameters (address, size) are passed to an OS kernel that is
5986 "Multi-File Images" contain several images, typically an OS
5987 (Linux) kernel image and one or more data images like
5988 RAMDisks. This construct is useful for instance when you want
5989 to boot over the network using BOOTP etc., where the boot
5990 server provides just a single image file, but you want to get
5991 for instance an OS kernel and a RAMDisk image.
5993 "Multi-File Images" start with a list of image sizes, each
5994 image size (in bytes) specified by an "uint32_t" in network
5995 byte order. This list is terminated by an "(uint32_t)0".
5996 Immediately after the terminating 0 follow the images, one by
5997 one, all aligned on "uint32_t" boundaries (size rounded up to
5998 a multiple of 4 bytes).
6000 "Firmware Images" are binary images containing firmware (like
6001 U-Boot or FPGA images) which usually will be programmed to
6004 "Script files" are command sequences that will be executed by
6005 U-Boot's command interpreter; this feature is especially
6006 useful when you configure U-Boot to use a real shell (hush)
6007 as command interpreter.
6009 Booting the Linux zImage:
6010 -------------------------
6012 On some platforms, it's possible to boot Linux zImage. This is done
6013 using the "bootz" command. The syntax of "bootz" command is the same
6014 as the syntax of "bootm" command.
6016 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6017 kernel with raw initrd images. The syntax is slightly different, the
6018 address of the initrd must be augmented by it's size, in the following
6019 format: "<initrd addres>:<initrd size>".
6025 One of the features of U-Boot is that you can dynamically load and
6026 run "standalone" applications, which can use some resources of
6027 U-Boot like console I/O functions or interrupt services.
6029 Two simple examples are included with the sources:
6034 'examples/hello_world.c' contains a small "Hello World" Demo
6035 application; it is automatically compiled when you build U-Boot.
6036 It's configured to run at address 0x00040004, so you can play with it
6040 ## Ready for S-Record download ...
6041 ~>examples/hello_world.srec
6042 1 2 3 4 5 6 7 8 9 10 11 ...
6043 [file transfer complete]
6045 ## Start Addr = 0x00040004
6047 => go 40004 Hello World! This is a test.
6048 ## Starting application at 0x00040004 ...
6059 Hit any key to exit ...
6061 ## Application terminated, rc = 0x0
6063 Another example, which demonstrates how to register a CPM interrupt
6064 handler with the U-Boot code, can be found in 'examples/timer.c'.
6065 Here, a CPM timer is set up to generate an interrupt every second.
6066 The interrupt service routine is trivial, just printing a '.'
6067 character, but this is just a demo program. The application can be
6068 controlled by the following keys:
6070 ? - print current values og the CPM Timer registers
6071 b - enable interrupts and start timer
6072 e - stop timer and disable interrupts
6073 q - quit application
6076 ## Ready for S-Record download ...
6077 ~>examples/timer.srec
6078 1 2 3 4 5 6 7 8 9 10 11 ...
6079 [file transfer complete]
6081 ## Start Addr = 0x00040004
6084 ## Starting application at 0x00040004 ...
6087 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6090 [q, b, e, ?] Set interval 1000000 us
6093 [q, b, e, ?] ........
6094 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6097 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6100 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6103 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6105 [q, b, e, ?] ...Stopping timer
6107 [q, b, e, ?] ## Application terminated, rc = 0x0
6113 Over time, many people have reported problems when trying to use the
6114 "minicom" terminal emulation program for serial download. I (wd)
6115 consider minicom to be broken, and recommend not to use it. Under
6116 Unix, I recommend to use C-Kermit for general purpose use (and
6117 especially for kermit binary protocol download ("loadb" command), and
6118 use "cu" for S-Record download ("loads" command). See
6119 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6120 for help with kermit.
6123 Nevertheless, if you absolutely want to use it try adding this
6124 configuration to your "File transfer protocols" section:
6126 Name Program Name U/D FullScr IO-Red. Multi
6127 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6128 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6134 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6135 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6137 Building requires a cross environment; it is known to work on
6138 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6139 need gmake since the Makefiles are not compatible with BSD make).
6140 Note that the cross-powerpc package does not install include files;
6141 attempting to build U-Boot will fail because <machine/ansi.h> is
6142 missing. This file has to be installed and patched manually:
6144 # cd /usr/pkg/cross/powerpc-netbsd/include
6146 # ln -s powerpc machine
6147 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6148 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6150 Native builds *don't* work due to incompatibilities between native
6151 and U-Boot include files.
6153 Booting assumes that (the first part of) the image booted is a
6154 stage-2 loader which in turn loads and then invokes the kernel
6155 proper. Loader sources will eventually appear in the NetBSD source
6156 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6157 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6160 Implementation Internals:
6161 =========================
6163 The following is not intended to be a complete description of every
6164 implementation detail. However, it should help to understand the
6165 inner workings of U-Boot and make it easier to port it to custom
6169 Initial Stack, Global Data:
6170 ---------------------------
6172 The implementation of U-Boot is complicated by the fact that U-Boot
6173 starts running out of ROM (flash memory), usually without access to
6174 system RAM (because the memory controller is not initialized yet).
6175 This means that we don't have writable Data or BSS segments, and BSS
6176 is not initialized as zero. To be able to get a C environment working
6177 at all, we have to allocate at least a minimal stack. Implementation
6178 options for this are defined and restricted by the CPU used: Some CPU
6179 models provide on-chip memory (like the IMMR area on MPC8xx and
6180 MPC826x processors), on others (parts of) the data cache can be
6181 locked as (mis-) used as memory, etc.
6183 Chris Hallinan posted a good summary of these issues to the
6184 U-Boot mailing list:
6186 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6187 From: "Chris Hallinan" <clh@net1plus.com>
6188 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6191 Correct me if I'm wrong, folks, but the way I understand it
6192 is this: Using DCACHE as initial RAM for Stack, etc, does not
6193 require any physical RAM backing up the cache. The cleverness
6194 is that the cache is being used as a temporary supply of
6195 necessary storage before the SDRAM controller is setup. It's
6196 beyond the scope of this list to explain the details, but you
6197 can see how this works by studying the cache architecture and
6198 operation in the architecture and processor-specific manuals.
6200 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6201 is another option for the system designer to use as an
6202 initial stack/RAM area prior to SDRAM being available. Either
6203 option should work for you. Using CS 4 should be fine if your
6204 board designers haven't used it for something that would
6205 cause you grief during the initial boot! It is frequently not
6208 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6209 with your processor/board/system design. The default value
6210 you will find in any recent u-boot distribution in
6211 walnut.h should work for you. I'd set it to a value larger
6212 than your SDRAM module. If you have a 64MB SDRAM module, set
6213 it above 400_0000. Just make sure your board has no resources
6214 that are supposed to respond to that address! That code in
6215 start.S has been around a while and should work as is when
6216 you get the config right.
6221 It is essential to remember this, since it has some impact on the C
6222 code for the initialization procedures:
6224 * Initialized global data (data segment) is read-only. Do not attempt
6227 * Do not use any uninitialized global data (or implicitly initialized
6228 as zero data - BSS segment) at all - this is undefined, initiali-
6229 zation is performed later (when relocating to RAM).
6231 * Stack space is very limited. Avoid big data buffers or things like
6234 Having only the stack as writable memory limits means we cannot use
6235 normal global data to share information between the code. But it
6236 turned out that the implementation of U-Boot can be greatly
6237 simplified by making a global data structure (gd_t) available to all
6238 functions. We could pass a pointer to this data as argument to _all_
6239 functions, but this would bloat the code. Instead we use a feature of
6240 the GCC compiler (Global Register Variables) to share the data: we
6241 place a pointer (gd) to the global data into a register which we
6242 reserve for this purpose.
6244 When choosing a register for such a purpose we are restricted by the
6245 relevant (E)ABI specifications for the current architecture, and by
6246 GCC's implementation.
6248 For PowerPC, the following registers have specific use:
6250 R2: reserved for system use
6251 R3-R4: parameter passing and return values
6252 R5-R10: parameter passing
6253 R13: small data area pointer
6257 (U-Boot also uses R12 as internal GOT pointer. r12
6258 is a volatile register so r12 needs to be reset when
6259 going back and forth between asm and C)
6261 ==> U-Boot will use R2 to hold a pointer to the global data
6263 Note: on PPC, we could use a static initializer (since the
6264 address of the global data structure is known at compile time),
6265 but it turned out that reserving a register results in somewhat
6266 smaller code - although the code savings are not that big (on
6267 average for all boards 752 bytes for the whole U-Boot image,
6268 624 text + 127 data).
6270 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6271 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6273 ==> U-Boot will use P3 to hold a pointer to the global data
6275 On ARM, the following registers are used:
6277 R0: function argument word/integer result
6278 R1-R3: function argument word
6279 R9: platform specific
6280 R10: stack limit (used only if stack checking is enabled)
6281 R11: argument (frame) pointer
6282 R12: temporary workspace
6285 R15: program counter
6287 ==> U-Boot will use R9 to hold a pointer to the global data
6289 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6291 On Nios II, the ABI is documented here:
6292 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6294 ==> U-Boot will use gp to hold a pointer to the global data
6296 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6297 to access small data sections, so gp is free.
6299 On NDS32, the following registers are used:
6301 R0-R1: argument/return
6303 R15: temporary register for assembler
6304 R16: trampoline register
6305 R28: frame pointer (FP)
6306 R29: global pointer (GP)
6307 R30: link register (LP)
6308 R31: stack pointer (SP)
6309 PC: program counter (PC)
6311 ==> U-Boot will use R10 to hold a pointer to the global data
6313 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6314 or current versions of GCC may "optimize" the code too much.
6319 U-Boot runs in system state and uses physical addresses, i.e. the
6320 MMU is not used either for address mapping nor for memory protection.
6322 The available memory is mapped to fixed addresses using the memory
6323 controller. In this process, a contiguous block is formed for each
6324 memory type (Flash, SDRAM, SRAM), even when it consists of several
6325 physical memory banks.
6327 U-Boot is installed in the first 128 kB of the first Flash bank (on
6328 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6329 booting and sizing and initializing DRAM, the code relocates itself
6330 to the upper end of DRAM. Immediately below the U-Boot code some
6331 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6332 configuration setting]. Below that, a structure with global Board
6333 Info data is placed, followed by the stack (growing downward).
6335 Additionally, some exception handler code is copied to the low 8 kB
6336 of DRAM (0x00000000 ... 0x00001FFF).
6338 So a typical memory configuration with 16 MB of DRAM could look like
6341 0x0000 0000 Exception Vector code
6344 0x0000 2000 Free for Application Use
6350 0x00FB FF20 Monitor Stack (Growing downward)
6351 0x00FB FFAC Board Info Data and permanent copy of global data
6352 0x00FC 0000 Malloc Arena
6355 0x00FE 0000 RAM Copy of Monitor Code
6356 ... eventually: LCD or video framebuffer
6357 ... eventually: pRAM (Protected RAM - unchanged by reset)
6358 0x00FF FFFF [End of RAM]
6361 System Initialization:
6362 ----------------------
6364 In the reset configuration, U-Boot starts at the reset entry point
6365 (on most PowerPC systems at address 0x00000100). Because of the reset
6366 configuration for CS0# this is a mirror of the on board Flash memory.
6367 To be able to re-map memory U-Boot then jumps to its link address.
6368 To be able to implement the initialization code in C, a (small!)
6369 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6370 which provide such a feature like MPC8xx or MPC8260), or in a locked
6371 part of the data cache. After that, U-Boot initializes the CPU core,
6372 the caches and the SIU.
6374 Next, all (potentially) available memory banks are mapped using a
6375 preliminary mapping. For example, we put them on 512 MB boundaries
6376 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6377 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6378 programmed for SDRAM access. Using the temporary configuration, a
6379 simple memory test is run that determines the size of the SDRAM
6382 When there is more than one SDRAM bank, and the banks are of
6383 different size, the largest is mapped first. For equal size, the first
6384 bank (CS2#) is mapped first. The first mapping is always for address
6385 0x00000000, with any additional banks following immediately to create
6386 contiguous memory starting from 0.
6388 Then, the monitor installs itself at the upper end of the SDRAM area
6389 and allocates memory for use by malloc() and for the global Board
6390 Info data; also, the exception vector code is copied to the low RAM
6391 pages, and the final stack is set up.
6393 Only after this relocation will you have a "normal" C environment;
6394 until that you are restricted in several ways, mostly because you are
6395 running from ROM, and because the code will have to be relocated to a
6399 U-Boot Porting Guide:
6400 ----------------------
6402 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6406 int main(int argc, char *argv[])
6408 sighandler_t no_more_time;
6410 signal(SIGALRM, no_more_time);
6411 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6413 if (available_money > available_manpower) {
6414 Pay consultant to port U-Boot;
6418 Download latest U-Boot source;
6420 Subscribe to u-boot mailing list;
6423 email("Hi, I am new to U-Boot, how do I get started?");
6426 Read the README file in the top level directory;
6427 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6428 Read applicable doc/*.README;
6429 Read the source, Luke;
6430 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6433 if (available_money > toLocalCurrency ($2500))
6436 Add a lot of aggravation and time;
6438 if (a similar board exists) { /* hopefully... */
6439 cp -a board/<similar> board/<myboard>
6440 cp include/configs/<similar>.h include/configs/<myboard>.h
6442 Create your own board support subdirectory;
6443 Create your own board include/configs/<myboard>.h file;
6445 Edit new board/<myboard> files
6446 Edit new include/configs/<myboard>.h
6451 Add / modify source code;
6455 email("Hi, I am having problems...");
6457 Send patch file to the U-Boot email list;
6458 if (reasonable critiques)
6459 Incorporate improvements from email list code review;
6461 Defend code as written;
6467 void no_more_time (int sig)
6476 All contributions to U-Boot should conform to the Linux kernel
6477 coding style; see the file "Documentation/CodingStyle" and the script
6478 "scripts/Lindent" in your Linux kernel source directory.
6480 Source files originating from a different project (for example the
6481 MTD subsystem) are generally exempt from these guidelines and are not
6482 reformatted to ease subsequent migration to newer versions of those
6485 Please note that U-Boot is implemented in C (and to some small parts in
6486 Assembler); no C++ is used, so please do not use C++ style comments (//)
6489 Please also stick to the following formatting rules:
6490 - remove any trailing white space
6491 - use TAB characters for indentation and vertical alignment, not spaces
6492 - make sure NOT to use DOS '\r\n' line feeds
6493 - do not add more than 2 consecutive empty lines to source files
6494 - do not add trailing empty lines to source files
6496 Submissions which do not conform to the standards may be returned
6497 with a request to reformat the changes.
6503 Since the number of patches for U-Boot is growing, we need to
6504 establish some rules. Submissions which do not conform to these rules
6505 may be rejected, even when they contain important and valuable stuff.
6507 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6509 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6510 see http://lists.denx.de/mailman/listinfo/u-boot
6512 When you send a patch, please include the following information with
6515 * For bug fixes: a description of the bug and how your patch fixes
6516 this bug. Please try to include a way of demonstrating that the
6517 patch actually fixes something.
6519 * For new features: a description of the feature and your
6522 * A CHANGELOG entry as plaintext (separate from the patch)
6524 * For major contributions, add a MAINTAINERS file with your
6525 information and associated file and directory references.
6527 * When you add support for a new board, don't forget to add a
6528 maintainer e-mail address to the boards.cfg file, too.
6530 * If your patch adds new configuration options, don't forget to
6531 document these in the README file.
6533 * The patch itself. If you are using git (which is *strongly*
6534 recommended) you can easily generate the patch using the
6535 "git format-patch". If you then use "git send-email" to send it to
6536 the U-Boot mailing list, you will avoid most of the common problems
6537 with some other mail clients.
6539 If you cannot use git, use "diff -purN OLD NEW". If your version of
6540 diff does not support these options, then get the latest version of
6543 The current directory when running this command shall be the parent
6544 directory of the U-Boot source tree (i. e. please make sure that
6545 your patch includes sufficient directory information for the
6548 We prefer patches as plain text. MIME attachments are discouraged,
6549 and compressed attachments must not be used.
6551 * If one logical set of modifications affects or creates several
6552 files, all these changes shall be submitted in a SINGLE patch file.
6554 * Changesets that contain different, unrelated modifications shall be
6555 submitted as SEPARATE patches, one patch per changeset.
6560 * Before sending the patch, run the MAKEALL script on your patched
6561 source tree and make sure that no errors or warnings are reported
6562 for any of the boards.
6564 * Keep your modifications to the necessary minimum: A patch
6565 containing several unrelated changes or arbitrary reformats will be
6566 returned with a request to re-formatting / split it.
6568 * If you modify existing code, make sure that your new code does not
6569 add to the memory footprint of the code ;-) Small is beautiful!
6570 When adding new features, these should compile conditionally only
6571 (using #ifdef), and the resulting code with the new feature
6572 disabled must not need more memory than the old code without your
6575 * Remember that there is a size limit of 100 kB per message on the
6576 u-boot mailing list. Bigger patches will be moderated. If they are
6577 reasonable and not too big, they will be acknowledged. But patches
6578 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob