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 eanbeld 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
893 - Safe printf() functions
894 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
895 the printf() functions. These are defined in
896 include/vsprintf.h and include snprintf(), vsnprintf() and
897 so on. Code size increase is approximately 300-500 bytes.
898 If this option is not given then these functions will
899 silently discard their buffer size argument - this means
900 you are not getting any overflow checking in this case.
902 - Boot Delay: CONFIG_BOOTDELAY - in seconds
903 Delay before automatically booting the default image;
904 set to -1 to disable autoboot.
905 set to -2 to autoboot with no delay and not check for abort
906 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
908 See doc/README.autoboot for these options that
909 work with CONFIG_BOOTDELAY. None are required.
910 CONFIG_BOOT_RETRY_TIME
911 CONFIG_BOOT_RETRY_MIN
912 CONFIG_AUTOBOOT_KEYED
913 CONFIG_AUTOBOOT_PROMPT
914 CONFIG_AUTOBOOT_DELAY_STR
915 CONFIG_AUTOBOOT_STOP_STR
916 CONFIG_ZERO_BOOTDELAY_CHECK
917 CONFIG_RESET_TO_RETRY
921 Only needed when CONFIG_BOOTDELAY is enabled;
922 define a command string that is automatically executed
923 when no character is read on the console interface
924 within "Boot Delay" after reset.
927 This can be used to pass arguments to the bootm
928 command. The value of CONFIG_BOOTARGS goes into the
929 environment value "bootargs".
931 CONFIG_RAMBOOT and CONFIG_NFSBOOT
932 The value of these goes into the environment as
933 "ramboot" and "nfsboot" respectively, and can be used
934 as a convenience, when switching between booting from
938 CONFIG_BOOTCOUNT_LIMIT
939 Implements a mechanism for detecting a repeating reboot
941 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
944 If no softreset save registers are found on the hardware
945 "bootcount" is stored in the environment. To prevent a
946 saveenv on all reboots, the environment variable
947 "upgrade_available" is used. If "upgrade_available" is
948 0, "bootcount" is always 0, if "upgrade_available" is
949 1 "bootcount" is incremented in the environment.
950 So the Userspace Applikation must set the "upgrade_available"
951 and "bootcount" variable to 0, if a boot was successfully.
956 When this option is #defined, the existence of the
957 environment variable "preboot" will be checked
958 immediately before starting the CONFIG_BOOTDELAY
959 countdown and/or running the auto-boot command resp.
960 entering interactive mode.
962 This feature is especially useful when "preboot" is
963 automatically generated or modified. For an example
964 see the LWMON board specific code: here "preboot" is
965 modified when the user holds down a certain
966 combination of keys on the (special) keyboard when
969 - Serial Download Echo Mode:
971 If defined to 1, all characters received during a
972 serial download (using the "loads" command) are
973 echoed back. This might be needed by some terminal
974 emulations (like "cu"), but may as well just take
975 time on others. This setting #define's the initial
976 value of the "loads_echo" environment variable.
978 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
980 Select one of the baudrates listed in
981 CONFIG_SYS_BAUDRATE_TABLE, see below.
984 Monitor commands can be included or excluded
985 from the build by using the #include files
986 <config_cmd_all.h> and #undef'ing unwanted
987 commands, or adding #define's for wanted commands.
989 The default command configuration includes all commands
990 except those marked below with a "*".
992 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
993 CONFIG_CMD_ASKENV * ask for env variable
994 CONFIG_CMD_BDI bdinfo
995 CONFIG_CMD_BEDBUG * Include BedBug Debugger
996 CONFIG_CMD_BMP * BMP support
997 CONFIG_CMD_BSP * Board specific commands
998 CONFIG_CMD_BOOTD bootd
999 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1000 CONFIG_CMD_CACHE * icache, dcache
1001 CONFIG_CMD_CLK * clock command support
1002 CONFIG_CMD_CONSOLE coninfo
1003 CONFIG_CMD_CRC32 * crc32
1004 CONFIG_CMD_DATE * support for RTC, date/time...
1005 CONFIG_CMD_DHCP * DHCP support
1006 CONFIG_CMD_DIAG * Diagnostics
1007 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1008 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1009 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1010 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1011 CONFIG_CMD_DTT * Digital Therm and Thermostat
1012 CONFIG_CMD_ECHO echo arguments
1013 CONFIG_CMD_EDITENV edit env variable
1014 CONFIG_CMD_EEPROM * EEPROM read/write support
1015 CONFIG_CMD_ELF * bootelf, bootvx
1016 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1017 CONFIG_CMD_ENV_FLAGS * display details about env flags
1018 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1019 CONFIG_CMD_EXPORTENV * export the environment
1020 CONFIG_CMD_EXT2 * ext2 command support
1021 CONFIG_CMD_EXT4 * ext4 command support
1022 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1023 that work for multiple fs types
1024 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1025 CONFIG_CMD_SAVEENV saveenv
1026 CONFIG_CMD_FDC * Floppy Disk Support
1027 CONFIG_CMD_FAT * FAT command support
1028 CONFIG_CMD_FLASH flinfo, erase, protect
1029 CONFIG_CMD_FPGA FPGA device initialization support
1030 CONFIG_CMD_FUSE * Device fuse support
1031 CONFIG_CMD_GETTIME * Get time since boot
1032 CONFIG_CMD_GO * the 'go' command (exec code)
1033 CONFIG_CMD_GREPENV * search environment
1034 CONFIG_CMD_HASH * calculate hash / digest
1035 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1036 CONFIG_CMD_I2C * I2C serial bus support
1037 CONFIG_CMD_IDE * IDE harddisk support
1038 CONFIG_CMD_IMI iminfo
1039 CONFIG_CMD_IMLS List all images found in NOR flash
1040 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1041 CONFIG_CMD_IMMAP * IMMR dump support
1042 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1043 CONFIG_CMD_IMPORTENV * import an environment
1044 CONFIG_CMD_INI * import data from an ini file into the env
1045 CONFIG_CMD_IRQ * irqinfo
1046 CONFIG_CMD_ITEST Integer/string test of 2 values
1047 CONFIG_CMD_JFFS2 * JFFS2 Support
1048 CONFIG_CMD_KGDB * kgdb
1049 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1050 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1052 CONFIG_CMD_LOADB loadb
1053 CONFIG_CMD_LOADS loads
1054 CONFIG_CMD_MD5SUM * print md5 message digest
1055 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1056 CONFIG_CMD_MEMINFO * Display detailed memory information
1057 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1059 CONFIG_CMD_MEMTEST * mtest
1060 CONFIG_CMD_MISC Misc functions like sleep etc
1061 CONFIG_CMD_MMC * MMC memory mapped support
1062 CONFIG_CMD_MII * MII utility commands
1063 CONFIG_CMD_MTDPARTS * MTD partition support
1064 CONFIG_CMD_NAND * NAND support
1065 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1066 CONFIG_CMD_NFS NFS support
1067 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1068 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1069 CONFIG_CMD_PCI * pciinfo
1070 CONFIG_CMD_PCMCIA * PCMCIA support
1071 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1073 CONFIG_CMD_PORTIO * Port I/O
1074 CONFIG_CMD_READ * Read raw data from partition
1075 CONFIG_CMD_REGINFO * Register dump
1076 CONFIG_CMD_RUN run command in env variable
1077 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1078 CONFIG_CMD_SAVES * save S record dump
1079 CONFIG_CMD_SCSI * SCSI Support
1080 CONFIG_CMD_SDRAM * print SDRAM configuration information
1081 (requires CONFIG_CMD_I2C)
1082 CONFIG_CMD_SETGETDCR Support for DCR Register access
1084 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1085 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1086 (requires CONFIG_CMD_MEMORY)
1087 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1088 CONFIG_CMD_SOURCE "source" command Support
1089 CONFIG_CMD_SPI * SPI serial bus support
1090 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1091 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1092 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1093 CONFIG_CMD_TIMER * access to the system tick timer
1094 CONFIG_CMD_USB * USB support
1095 CONFIG_CMD_CDP * Cisco Discover Protocol support
1096 CONFIG_CMD_MFSL * Microblaze FSL support
1097 CONFIG_CMD_XIMG Load part of Multi Image
1098 CONFIG_CMD_UUID * Generate random UUID or GUID string
1100 EXAMPLE: If you want all functions except of network
1101 support you can write:
1103 #include "config_cmd_all.h"
1104 #undef CONFIG_CMD_NET
1107 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1109 Note: Don't enable the "icache" and "dcache" commands
1110 (configuration option CONFIG_CMD_CACHE) unless you know
1111 what you (and your U-Boot users) are doing. Data
1112 cache cannot be enabled on systems like the 8xx or
1113 8260 (where accesses to the IMMR region must be
1114 uncached), and it cannot be disabled on all other
1115 systems where we (mis-) use the data cache to hold an
1116 initial stack and some data.
1119 XXX - this list needs to get updated!
1121 - Regular expression support:
1123 If this variable is defined, U-Boot is linked against
1124 the SLRE (Super Light Regular Expression) library,
1125 which adds regex support to some commands, as for
1126 example "env grep" and "setexpr".
1130 If this variable is defined, U-Boot will use a device tree
1131 to configure its devices, instead of relying on statically
1132 compiled #defines in the board file. This option is
1133 experimental and only available on a few boards. The device
1134 tree is available in the global data as gd->fdt_blob.
1136 U-Boot needs to get its device tree from somewhere. This can
1137 be done using one of the two options below:
1140 If this variable is defined, U-Boot will embed a device tree
1141 binary in its image. This device tree file should be in the
1142 board directory and called <soc>-<board>.dts. The binary file
1143 is then picked up in board_init_f() and made available through
1144 the global data structure as gd->blob.
1147 If this variable is defined, U-Boot will build a device tree
1148 binary. It will be called u-boot.dtb. Architecture-specific
1149 code will locate it at run-time. Generally this works by:
1151 cat u-boot.bin u-boot.dtb >image.bin
1153 and in fact, U-Boot does this for you, creating a file called
1154 u-boot-dtb.bin which is useful in the common case. You can
1155 still use the individual files if you need something more
1160 If this variable is defined, it enables watchdog
1161 support for the SoC. There must be support in the SoC
1162 specific code for a watchdog. For the 8xx and 8260
1163 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1164 register. When supported for a specific SoC is
1165 available, then no further board specific code should
1166 be needed to use it.
1169 When using a watchdog circuitry external to the used
1170 SoC, then define this variable and provide board
1171 specific code for the "hw_watchdog_reset" function.
1173 CONFIG_AT91_HW_WDT_TIMEOUT
1174 specify the timeout in seconds. default 2 seconds.
1177 CONFIG_VERSION_VARIABLE
1178 If this variable is defined, an environment variable
1179 named "ver" is created by U-Boot showing the U-Boot
1180 version as printed by the "version" command.
1181 Any change to this variable will be reverted at the
1186 When CONFIG_CMD_DATE is selected, the type of the RTC
1187 has to be selected, too. Define exactly one of the
1190 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1191 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1192 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1193 CONFIG_RTC_MC146818 - use MC146818 RTC
1194 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1195 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1196 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1197 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1198 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1199 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1200 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1201 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1202 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1205 Note that if the RTC uses I2C, then the I2C interface
1206 must also be configured. See I2C Support, below.
1209 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1211 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1212 chip-ngpio pairs that tell the PCA953X driver the number of
1213 pins supported by a particular chip.
1215 Note that if the GPIO device uses I2C, then the I2C interface
1216 must also be configured. See I2C Support, below.
1219 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1220 accesses and can checksum them or write a list of them out
1221 to memory. See the 'iotrace' command for details. This is
1222 useful for testing device drivers since it can confirm that
1223 the driver behaves the same way before and after a code
1224 change. Currently this is supported on sandbox and arm. To
1225 add support for your architecture, add '#include <iotrace.h>'
1226 to the bottom of arch/<arch>/include/asm/io.h and test.
1228 Example output from the 'iotrace stats' command is below.
1229 Note that if the trace buffer is exhausted, the checksum will
1230 still continue to operate.
1233 Start: 10000000 (buffer start address)
1234 Size: 00010000 (buffer size)
1235 Offset: 00000120 (current buffer offset)
1236 Output: 10000120 (start + offset)
1237 Count: 00000018 (number of trace records)
1238 CRC32: 9526fb66 (CRC32 of all trace records)
1240 - Timestamp Support:
1242 When CONFIG_TIMESTAMP is selected, the timestamp
1243 (date and time) of an image is printed by image
1244 commands like bootm or iminfo. This option is
1245 automatically enabled when you select CONFIG_CMD_DATE .
1247 - Partition Labels (disklabels) Supported:
1248 Zero or more of the following:
1249 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1250 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1251 Intel architecture, USB sticks, etc.
1252 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1253 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1254 bootloader. Note 2TB partition limit; see
1256 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1258 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1259 CONFIG_CMD_SCSI) you must configure support for at
1260 least one non-MTD partition type as well.
1263 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1264 board configurations files but used nowhere!
1266 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1267 be performed by calling the function
1268 ide_set_reset(int reset)
1269 which has to be defined in a board specific file
1274 Set this to enable ATAPI support.
1279 Set this to enable support for disks larger than 137GB
1280 Also look at CONFIG_SYS_64BIT_LBA.
1281 Whithout these , LBA48 support uses 32bit variables and will 'only'
1282 support disks up to 2.1TB.
1284 CONFIG_SYS_64BIT_LBA:
1285 When enabled, makes the IDE subsystem use 64bit sector addresses.
1289 At the moment only there is only support for the
1290 SYM53C8XX SCSI controller; define
1291 CONFIG_SCSI_SYM53C8XX to enable it.
1293 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1294 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1295 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1296 maximum numbers of LUNs, SCSI ID's and target
1298 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1300 The environment variable 'scsidevs' is set to the number of
1301 SCSI devices found during the last scan.
1303 - NETWORK Support (PCI):
1305 Support for Intel 8254x/8257x gigabit chips.
1308 Utility code for direct access to the SPI bus on Intel 8257x.
1309 This does not do anything useful unless you set at least one
1310 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1312 CONFIG_E1000_SPI_GENERIC
1313 Allow generic access to the SPI bus on the Intel 8257x, for
1314 example with the "sspi" command.
1317 Management command for E1000 devices. When used on devices
1318 with SPI support you can reprogram the EEPROM from U-Boot.
1321 Support for Intel 82557/82559/82559ER chips.
1322 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1323 write routine for first time initialisation.
1326 Support for Digital 2114x chips.
1327 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1328 modem chip initialisation (KS8761/QS6611).
1331 Support for National dp83815 chips.
1334 Support for National dp8382[01] gigabit chips.
1336 - NETWORK Support (other):
1338 CONFIG_DRIVER_AT91EMAC
1339 Support for AT91RM9200 EMAC.
1342 Define this to use reduced MII inteface
1344 CONFIG_DRIVER_AT91EMAC_QUIET
1345 If this defined, the driver is quiet.
1346 The driver doen't show link status messages.
1348 CONFIG_CALXEDA_XGMAC
1349 Support for the Calxeda XGMAC device
1352 Support for SMSC's LAN91C96 chips.
1354 CONFIG_LAN91C96_BASE
1355 Define this to hold the physical address
1356 of the LAN91C96's I/O space
1358 CONFIG_LAN91C96_USE_32_BIT
1359 Define this to enable 32 bit addressing
1362 Support for SMSC's LAN91C111 chip
1364 CONFIG_SMC91111_BASE
1365 Define this to hold the physical address
1366 of the device (I/O space)
1368 CONFIG_SMC_USE_32_BIT
1369 Define this if data bus is 32 bits
1371 CONFIG_SMC_USE_IOFUNCS
1372 Define this to use i/o functions instead of macros
1373 (some hardware wont work with macros)
1375 CONFIG_DRIVER_TI_EMAC
1376 Support for davinci emac
1378 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1379 Define this if you have more then 3 PHYs.
1382 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1384 CONFIG_FTGMAC100_EGIGA
1385 Define this to use GE link update with gigabit PHY.
1386 Define this if FTGMAC100 is connected to gigabit PHY.
1387 If your system has 10/100 PHY only, it might not occur
1388 wrong behavior. Because PHY usually return timeout or
1389 useless data when polling gigabit status and gigabit
1390 control registers. This behavior won't affect the
1391 correctnessof 10/100 link speed update.
1394 Support for SMSC's LAN911x and LAN921x chips
1397 Define this to hold the physical address
1398 of the device (I/O space)
1400 CONFIG_SMC911X_32_BIT
1401 Define this if data bus is 32 bits
1403 CONFIG_SMC911X_16_BIT
1404 Define this if data bus is 16 bits. If your processor
1405 automatically converts one 32 bit word to two 16 bit
1406 words you may also try CONFIG_SMC911X_32_BIT.
1409 Support for Renesas on-chip Ethernet controller
1411 CONFIG_SH_ETHER_USE_PORT
1412 Define the number of ports to be used
1414 CONFIG_SH_ETHER_PHY_ADDR
1415 Define the ETH PHY's address
1417 CONFIG_SH_ETHER_CACHE_WRITEBACK
1418 If this option is set, the driver enables cache flush.
1422 Support for PWM modul on the imx6.
1426 Support TPM devices.
1428 CONFIG_TPM_TIS_INFINEON
1429 Support for Infineon i2c bus TPM devices. Only one device
1430 per system is supported at this time.
1432 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1433 Define the burst count bytes upper limit
1435 CONFIG_TPM_ATMEL_TWI
1436 Support for Atmel TWI TPM device. Requires I2C support.
1439 Support for generic parallel port TPM devices. Only one device
1440 per system is supported at this time.
1442 CONFIG_TPM_TIS_BASE_ADDRESS
1443 Base address where the generic TPM device is mapped
1444 to. Contemporary x86 systems usually map it at
1448 Add tpm monitor functions.
1449 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1450 provides monitor access to authorized functions.
1453 Define this to enable the TPM support library which provides
1454 functional interfaces to some TPM commands.
1455 Requires support for a TPM device.
1457 CONFIG_TPM_AUTH_SESSIONS
1458 Define this to enable authorized functions in the TPM library.
1459 Requires CONFIG_TPM and CONFIG_SHA1.
1462 At the moment only the UHCI host controller is
1463 supported (PIP405, MIP405, MPC5200); define
1464 CONFIG_USB_UHCI to enable it.
1465 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1466 and define CONFIG_USB_STORAGE to enable the USB
1469 Supported are USB Keyboards and USB Floppy drives
1471 MPC5200 USB requires additional defines:
1473 for 528 MHz Clock: 0x0001bbbb
1477 for differential drivers: 0x00001000
1478 for single ended drivers: 0x00005000
1479 for differential drivers on PSC3: 0x00000100
1480 for single ended drivers on PSC3: 0x00004100
1481 CONFIG_SYS_USB_EVENT_POLL
1482 May be defined to allow interrupt polling
1483 instead of using asynchronous interrupts
1485 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1486 txfilltuning field in the EHCI controller on reset.
1488 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1489 HW module registers.
1492 Define the below if you wish to use the USB console.
1493 Once firmware is rebuilt from a serial console issue the
1494 command "setenv stdin usbtty; setenv stdout usbtty" and
1495 attach your USB cable. The Unix command "dmesg" should print
1496 it has found a new device. The environment variable usbtty
1497 can be set to gserial or cdc_acm to enable your device to
1498 appear to a USB host as a Linux gserial device or a
1499 Common Device Class Abstract Control Model serial device.
1500 If you select usbtty = gserial you should be able to enumerate
1502 # modprobe usbserial vendor=0xVendorID product=0xProductID
1503 else if using cdc_acm, simply setting the environment
1504 variable usbtty to be cdc_acm should suffice. The following
1505 might be defined in YourBoardName.h
1508 Define this to build a UDC device
1511 Define this to have a tty type of device available to
1512 talk to the UDC device
1515 Define this to enable the high speed support for usb
1516 device and usbtty. If this feature is enabled, a routine
1517 int is_usbd_high_speed(void)
1518 also needs to be defined by the driver to dynamically poll
1519 whether the enumeration has succeded at high speed or full
1522 CONFIG_SYS_CONSOLE_IS_IN_ENV
1523 Define this if you want stdin, stdout &/or stderr to
1527 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1528 Derive USB clock from external clock "blah"
1529 - CONFIG_SYS_USB_EXTC_CLK 0x02
1531 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1532 Derive USB clock from brgclk
1533 - CONFIG_SYS_USB_BRG_CLK 0x04
1535 If you have a USB-IF assigned VendorID then you may wish to
1536 define your own vendor specific values either in BoardName.h
1537 or directly in usbd_vendor_info.h. If you don't define
1538 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1539 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1540 should pretend to be a Linux device to it's target host.
1542 CONFIG_USBD_MANUFACTURER
1543 Define this string as the name of your company for
1544 - CONFIG_USBD_MANUFACTURER "my company"
1546 CONFIG_USBD_PRODUCT_NAME
1547 Define this string as the name of your product
1548 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1550 CONFIG_USBD_VENDORID
1551 Define this as your assigned Vendor ID from the USB
1552 Implementors Forum. This *must* be a genuine Vendor ID
1553 to avoid polluting the USB namespace.
1554 - CONFIG_USBD_VENDORID 0xFFFF
1556 CONFIG_USBD_PRODUCTID
1557 Define this as the unique Product ID
1559 - CONFIG_USBD_PRODUCTID 0xFFFF
1561 - ULPI Layer Support:
1562 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1563 the generic ULPI layer. The generic layer accesses the ULPI PHY
1564 via the platform viewport, so you need both the genric layer and
1565 the viewport enabled. Currently only Chipidea/ARC based
1566 viewport is supported.
1567 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1568 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1569 If your ULPI phy needs a different reference clock than the
1570 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1571 the appropriate value in Hz.
1574 The MMC controller on the Intel PXA is supported. To
1575 enable this define CONFIG_MMC. The MMC can be
1576 accessed from the boot prompt by mapping the device
1577 to physical memory similar to flash. Command line is
1578 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1579 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1582 Support for Renesas on-chip MMCIF controller
1584 CONFIG_SH_MMCIF_ADDR
1585 Define the base address of MMCIF registers
1588 Define the clock frequency for MMCIF
1591 Enable the generic MMC driver
1593 CONFIG_SUPPORT_EMMC_BOOT
1594 Enable some additional features of the eMMC boot partitions.
1596 CONFIG_SUPPORT_EMMC_RPMB
1597 Enable the commands for reading, writing and programming the
1598 key for the Replay Protection Memory Block partition in eMMC.
1600 - USB Device Firmware Update (DFU) class support:
1601 CONFIG_USB_FUNCTION_DFU
1602 This enables the USB portion of the DFU USB class
1605 This enables the command "dfu" which is used to have
1606 U-Boot create a DFU class device via USB. This command
1607 requires that the "dfu_alt_info" environment variable be
1608 set and define the alt settings to expose to the host.
1611 This enables support for exposing (e)MMC devices via DFU.
1614 This enables support for exposing NAND devices via DFU.
1617 This enables support for exposing RAM via DFU.
1618 Note: DFU spec refer to non-volatile memory usage, but
1619 allow usages beyond the scope of spec - here RAM usage,
1620 one that would help mostly the developer.
1622 CONFIG_SYS_DFU_DATA_BUF_SIZE
1623 Dfu transfer uses a buffer before writing data to the
1624 raw storage device. Make the size (in bytes) of this buffer
1625 configurable. The size of this buffer is also configurable
1626 through the "dfu_bufsiz" environment variable.
1628 CONFIG_SYS_DFU_MAX_FILE_SIZE
1629 When updating files rather than the raw storage device,
1630 we use a static buffer to copy the file into and then write
1631 the buffer once we've been given the whole file. Define
1632 this to the maximum filesize (in bytes) for the buffer.
1633 Default is 4 MiB if undefined.
1635 DFU_DEFAULT_POLL_TIMEOUT
1636 Poll timeout [ms], is the timeout a device can send to the
1637 host. The host must wait for this timeout before sending
1638 a subsequent DFU_GET_STATUS request to the device.
1640 DFU_MANIFEST_POLL_TIMEOUT
1641 Poll timeout [ms], which the device sends to the host when
1642 entering dfuMANIFEST state. Host waits this timeout, before
1643 sending again an USB request to the device.
1645 - USB Device Android Fastboot support:
1646 CONFIG_USB_FUNCTION_FASTBOOT
1647 This enables the USB part of the fastboot gadget
1650 This enables the command "fastboot" which enables the Android
1651 fastboot mode for the platform's USB device. Fastboot is a USB
1652 protocol for downloading images, flashing and device control
1653 used on Android devices.
1654 See doc/README.android-fastboot for more information.
1656 CONFIG_ANDROID_BOOT_IMAGE
1657 This enables support for booting images which use the Android
1658 image format header.
1660 CONFIG_FASTBOOT_BUF_ADDR
1661 The fastboot protocol requires a large memory buffer for
1662 downloads. Define this to the starting RAM address to use for
1665 CONFIG_FASTBOOT_BUF_SIZE
1666 The fastboot protocol requires a large memory buffer for
1667 downloads. This buffer should be as large as possible for a
1668 platform. Define this to the size available RAM for fastboot.
1670 CONFIG_FASTBOOT_FLASH
1671 The fastboot protocol includes a "flash" command for writing
1672 the downloaded image to a non-volatile storage device. Define
1673 this to enable the "fastboot flash" command.
1675 CONFIG_FASTBOOT_FLASH_MMC_DEV
1676 The fastboot "flash" command requires additional information
1677 regarding the non-volatile storage device. Define this to
1678 the eMMC device that fastboot should use to store the image.
1680 CONFIG_FASTBOOT_GPT_NAME
1681 The fastboot "flash" command supports writing the downloaded
1682 image to the Protective MBR and the Primary GUID Partition
1683 Table. (Additionally, this downloaded image is post-processed
1684 to generate and write the Backup GUID Partition Table.)
1685 This occurs when the specified "partition name" on the
1686 "fastboot flash" command line matches this value.
1687 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1689 - Journaling Flash filesystem support:
1690 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1691 CONFIG_JFFS2_NAND_DEV
1692 Define these for a default partition on a NAND device
1694 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1695 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1696 Define these for a default partition on a NOR device
1698 CONFIG_SYS_JFFS_CUSTOM_PART
1699 Define this to create an own partition. You have to provide a
1700 function struct part_info* jffs2_part_info(int part_num)
1702 If you define only one JFFS2 partition you may also want to
1703 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1704 to disable the command chpart. This is the default when you
1705 have not defined a custom partition
1707 - FAT(File Allocation Table) filesystem write function support:
1710 Define this to enable support for saving memory data as a
1711 file in FAT formatted partition.
1713 This will also enable the command "fatwrite" enabling the
1714 user to write files to FAT.
1716 CBFS (Coreboot Filesystem) support
1719 Define this to enable support for reading from a Coreboot
1720 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1723 - FAT(File Allocation Table) filesystem cluster size:
1724 CONFIG_FS_FAT_MAX_CLUSTSIZE
1726 Define the max cluster size for fat operations else
1727 a default value of 65536 will be defined.
1730 See Kconfig help for available keyboard drivers.
1734 Define this to enable a custom keyboard support.
1735 This simply calls drv_keyboard_init() which must be
1736 defined in your board-specific files. This option is deprecated
1737 and is only used by novena. For new boards, use driver model
1743 Define this to enable video support (for output to
1746 CONFIG_VIDEO_CT69000
1748 Enable Chips & Technologies 69000 Video chip
1750 CONFIG_VIDEO_SMI_LYNXEM
1751 Enable Silicon Motion SMI 712/710/810 Video chip. The
1752 video output is selected via environment 'videoout'
1753 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1756 For the CT69000 and SMI_LYNXEM drivers, videomode is
1757 selected via environment 'videomode'. Two different ways
1759 - "videomode=num" 'num' is a standard LiLo mode numbers.
1760 Following standard modes are supported (* is default):
1762 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1763 -------------+---------------------------------------------
1764 8 bits | 0x301* 0x303 0x305 0x161 0x307
1765 15 bits | 0x310 0x313 0x316 0x162 0x319
1766 16 bits | 0x311 0x314 0x317 0x163 0x31A
1767 24 bits | 0x312 0x315 0x318 ? 0x31B
1768 -------------+---------------------------------------------
1769 (i.e. setenv videomode 317; saveenv; reset;)
1771 - "videomode=bootargs" all the video parameters are parsed
1772 from the bootargs. (See drivers/video/videomodes.c)
1775 CONFIG_VIDEO_SED13806
1776 Enable Epson SED13806 driver. This driver supports 8bpp
1777 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1778 or CONFIG_VIDEO_SED13806_16BPP
1781 Enable the Freescale DIU video driver. Reference boards for
1782 SOCs that have a DIU should define this macro to enable DIU
1783 support, and should also define these other macros:
1789 CONFIG_VIDEO_SW_CURSOR
1790 CONFIG_VGA_AS_SINGLE_DEVICE
1792 CONFIG_VIDEO_BMP_LOGO
1794 The DIU driver will look for the 'video-mode' environment
1795 variable, and if defined, enable the DIU as a console during
1796 boot. See the documentation file README.video for a
1797 description of this variable.
1799 - LCD Support: CONFIG_LCD
1801 Define this to enable LCD support (for output to LCD
1802 display); also select one of the supported displays
1803 by defining one of these:
1807 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1809 CONFIG_NEC_NL6448AC33:
1811 NEC NL6448AC33-18. Active, color, single scan.
1813 CONFIG_NEC_NL6448BC20
1815 NEC NL6448BC20-08. 6.5", 640x480.
1816 Active, color, single scan.
1818 CONFIG_NEC_NL6448BC33_54
1820 NEC NL6448BC33-54. 10.4", 640x480.
1821 Active, color, single scan.
1825 Sharp 320x240. Active, color, single scan.
1826 It isn't 16x9, and I am not sure what it is.
1828 CONFIG_SHARP_LQ64D341
1830 Sharp LQ64D341 display, 640x480.
1831 Active, color, single scan.
1835 HLD1045 display, 640x480.
1836 Active, color, single scan.
1840 Optrex CBL50840-2 NF-FW 99 22 M5
1842 Hitachi LMG6912RPFC-00T
1846 320x240. Black & white.
1848 Normally display is black on white background; define
1849 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1851 CONFIG_LCD_ALIGNMENT
1853 Normally the LCD is page-aligned (typically 4KB). If this is
1854 defined then the LCD will be aligned to this value instead.
1855 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1856 here, since it is cheaper to change data cache settings on
1857 a per-section basis.
1859 CONFIG_CONSOLE_SCROLL_LINES
1861 When the console need to be scrolled, this is the number of
1862 lines to scroll by. It defaults to 1. Increasing this makes
1863 the console jump but can help speed up operation when scrolling
1868 Sometimes, for example if the display is mounted in portrait
1869 mode or even if it's mounted landscape but rotated by 180degree,
1870 we need to rotate our content of the display relative to the
1871 framebuffer, so that user can read the messages which are
1873 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1874 initialized with a given rotation from "vl_rot" out of
1875 "vidinfo_t" which is provided by the board specific code.
1876 The value for vl_rot is coded as following (matching to
1877 fbcon=rotate:<n> linux-kernel commandline):
1878 0 = no rotation respectively 0 degree
1879 1 = 90 degree rotation
1880 2 = 180 degree rotation
1881 3 = 270 degree rotation
1883 If CONFIG_LCD_ROTATION is not defined, the console will be
1884 initialized with 0degree rotation.
1888 Support drawing of RLE8-compressed bitmaps on the LCD.
1892 Enables an 'i2c edid' command which can read EDID
1893 information over I2C from an attached LCD display.
1895 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1897 If this option is set, the environment is checked for
1898 a variable "splashimage". If found, the usual display
1899 of logo, copyright and system information on the LCD
1900 is suppressed and the BMP image at the address
1901 specified in "splashimage" is loaded instead. The
1902 console is redirected to the "nulldev", too. This
1903 allows for a "silent" boot where a splash screen is
1904 loaded very quickly after power-on.
1906 CONFIG_SPLASHIMAGE_GUARD
1908 If this option is set, then U-Boot will prevent the environment
1909 variable "splashimage" from being set to a problematic address
1910 (see README.displaying-bmps).
1911 This option is useful for targets where, due to alignment
1912 restrictions, an improperly aligned BMP image will cause a data
1913 abort. If you think you will not have problems with unaligned
1914 accesses (for example because your toolchain prevents them)
1915 there is no need to set this option.
1917 CONFIG_SPLASH_SCREEN_ALIGN
1919 If this option is set the splash image can be freely positioned
1920 on the screen. Environment variable "splashpos" specifies the
1921 position as "x,y". If a positive number is given it is used as
1922 number of pixel from left/top. If a negative number is given it
1923 is used as number of pixel from right/bottom. You can also
1924 specify 'm' for centering the image.
1927 setenv splashpos m,m
1928 => image at center of screen
1930 setenv splashpos 30,20
1931 => image at x = 30 and y = 20
1933 setenv splashpos -10,m
1934 => vertically centered image
1935 at x = dspWidth - bmpWidth - 9
1937 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1939 If this option is set, additionally to standard BMP
1940 images, gzipped BMP images can be displayed via the
1941 splashscreen support or the bmp command.
1943 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1945 If this option is set, 8-bit RLE compressed BMP images
1946 can be displayed via the splashscreen support or the
1949 - Do compressing for memory range:
1952 If this option is set, it would use zlib deflate method
1953 to compress the specified memory at its best effort.
1955 - Compression support:
1958 Enabled by default to support gzip compressed images.
1962 If this option is set, support for bzip2 compressed
1963 images is included. If not, only uncompressed and gzip
1964 compressed images are supported.
1966 NOTE: the bzip2 algorithm requires a lot of RAM, so
1967 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1972 If this option is set, support for lzma compressed
1975 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1976 requires an amount of dynamic memory that is given by the
1979 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1981 Where lc and lp stand for, respectively, Literal context bits
1982 and Literal pos bits.
1984 This value is upper-bounded by 14MB in the worst case. Anyway,
1985 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1986 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1987 a very small buffer.
1989 Use the lzmainfo tool to determinate the lc and lp values and
1990 then calculate the amount of needed dynamic memory (ensuring
1991 the appropriate CONFIG_SYS_MALLOC_LEN value).
1995 If this option is set, support for LZO compressed images
2001 The address of PHY on MII bus.
2003 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2005 The clock frequency of the MII bus
2009 If this option is set, support for speed/duplex
2010 detection of gigabit PHY is included.
2012 CONFIG_PHY_RESET_DELAY
2014 Some PHY like Intel LXT971A need extra delay after
2015 reset before any MII register access is possible.
2016 For such PHY, set this option to the usec delay
2017 required. (minimum 300usec for LXT971A)
2019 CONFIG_PHY_CMD_DELAY (ppc4xx)
2021 Some PHY like Intel LXT971A need extra delay after
2022 command issued before MII status register can be read
2027 Define a default value for the IP address to use for
2028 the default Ethernet interface, in case this is not
2029 determined through e.g. bootp.
2030 (Environment variable "ipaddr")
2032 - Server IP address:
2035 Defines a default value for the IP address of a TFTP
2036 server to contact when using the "tftboot" command.
2037 (Environment variable "serverip")
2039 CONFIG_KEEP_SERVERADDR
2041 Keeps the server's MAC address, in the env 'serveraddr'
2042 for passing to bootargs (like Linux's netconsole option)
2044 - Gateway IP address:
2047 Defines a default value for the IP address of the
2048 default router where packets to other networks are
2050 (Environment variable "gatewayip")
2055 Defines a default value for the subnet mask (or
2056 routing prefix) which is used to determine if an IP
2057 address belongs to the local subnet or needs to be
2058 forwarded through a router.
2059 (Environment variable "netmask")
2061 - Multicast TFTP Mode:
2064 Defines whether you want to support multicast TFTP as per
2065 rfc-2090; for example to work with atftp. Lets lots of targets
2066 tftp down the same boot image concurrently. Note: the Ethernet
2067 driver in use must provide a function: mcast() to join/leave a
2070 - BOOTP Recovery Mode:
2071 CONFIG_BOOTP_RANDOM_DELAY
2073 If you have many targets in a network that try to
2074 boot using BOOTP, you may want to avoid that all
2075 systems send out BOOTP requests at precisely the same
2076 moment (which would happen for instance at recovery
2077 from a power failure, when all systems will try to
2078 boot, thus flooding the BOOTP server. Defining
2079 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2080 inserted before sending out BOOTP requests. The
2081 following delays are inserted then:
2083 1st BOOTP request: delay 0 ... 1 sec
2084 2nd BOOTP request: delay 0 ... 2 sec
2085 3rd BOOTP request: delay 0 ... 4 sec
2087 BOOTP requests: delay 0 ... 8 sec
2089 CONFIG_BOOTP_ID_CACHE_SIZE
2091 BOOTP packets are uniquely identified using a 32-bit ID. The
2092 server will copy the ID from client requests to responses and
2093 U-Boot will use this to determine if it is the destination of
2094 an incoming response. Some servers will check that addresses
2095 aren't in use before handing them out (usually using an ARP
2096 ping) and therefore take up to a few hundred milliseconds to
2097 respond. Network congestion may also influence the time it
2098 takes for a response to make it back to the client. If that
2099 time is too long, U-Boot will retransmit requests. In order
2100 to allow earlier responses to still be accepted after these
2101 retransmissions, U-Boot's BOOTP client keeps a small cache of
2102 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2103 cache. The default is to keep IDs for up to four outstanding
2104 requests. Increasing this will allow U-Boot to accept offers
2105 from a BOOTP client in networks with unusually high latency.
2107 - DHCP Advanced Options:
2108 You can fine tune the DHCP functionality by defining
2109 CONFIG_BOOTP_* symbols:
2111 CONFIG_BOOTP_SUBNETMASK
2112 CONFIG_BOOTP_GATEWAY
2113 CONFIG_BOOTP_HOSTNAME
2114 CONFIG_BOOTP_NISDOMAIN
2115 CONFIG_BOOTP_BOOTPATH
2116 CONFIG_BOOTP_BOOTFILESIZE
2119 CONFIG_BOOTP_SEND_HOSTNAME
2120 CONFIG_BOOTP_NTPSERVER
2121 CONFIG_BOOTP_TIMEOFFSET
2122 CONFIG_BOOTP_VENDOREX
2123 CONFIG_BOOTP_MAY_FAIL
2125 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2126 environment variable, not the BOOTP server.
2128 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2129 after the configured retry count, the call will fail
2130 instead of starting over. This can be used to fail over
2131 to Link-local IP address configuration if the DHCP server
2134 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2135 serverip from a DHCP server, it is possible that more
2136 than one DNS serverip is offered to the client.
2137 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2138 serverip will be stored in the additional environment
2139 variable "dnsip2". The first DNS serverip is always
2140 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2143 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2144 to do a dynamic update of a DNS server. To do this, they
2145 need the hostname of the DHCP requester.
2146 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2147 of the "hostname" environment variable is passed as
2148 option 12 to the DHCP server.
2150 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2152 A 32bit value in microseconds for a delay between
2153 receiving a "DHCP Offer" and sending the "DHCP Request".
2154 This fixes a problem with certain DHCP servers that don't
2155 respond 100% of the time to a "DHCP request". E.g. On an
2156 AT91RM9200 processor running at 180MHz, this delay needed
2157 to be *at least* 15,000 usec before a Windows Server 2003
2158 DHCP server would reply 100% of the time. I recommend at
2159 least 50,000 usec to be safe. The alternative is to hope
2160 that one of the retries will be successful but note that
2161 the DHCP timeout and retry process takes a longer than
2164 - Link-local IP address negotiation:
2165 Negotiate with other link-local clients on the local network
2166 for an address that doesn't require explicit configuration.
2167 This is especially useful if a DHCP server cannot be guaranteed
2168 to exist in all environments that the device must operate.
2170 See doc/README.link-local for more information.
2173 CONFIG_CDP_DEVICE_ID
2175 The device id used in CDP trigger frames.
2177 CONFIG_CDP_DEVICE_ID_PREFIX
2179 A two character string which is prefixed to the MAC address
2184 A printf format string which contains the ascii name of
2185 the port. Normally is set to "eth%d" which sets
2186 eth0 for the first Ethernet, eth1 for the second etc.
2188 CONFIG_CDP_CAPABILITIES
2190 A 32bit integer which indicates the device capabilities;
2191 0x00000010 for a normal host which does not forwards.
2195 An ascii string containing the version of the software.
2199 An ascii string containing the name of the platform.
2203 A 32bit integer sent on the trigger.
2205 CONFIG_CDP_POWER_CONSUMPTION
2207 A 16bit integer containing the power consumption of the
2208 device in .1 of milliwatts.
2210 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2212 A byte containing the id of the VLAN.
2214 - Status LED: CONFIG_STATUS_LED
2216 Several configurations allow to display the current
2217 status using a LED. For instance, the LED will blink
2218 fast while running U-Boot code, stop blinking as
2219 soon as a reply to a BOOTP request was received, and
2220 start blinking slow once the Linux kernel is running
2221 (supported by a status LED driver in the Linux
2222 kernel). Defining CONFIG_STATUS_LED enables this
2228 The status LED can be connected to a GPIO pin.
2229 In such cases, the gpio_led driver can be used as a
2230 status LED backend implementation. Define CONFIG_GPIO_LED
2231 to include the gpio_led driver in the U-Boot binary.
2233 CONFIG_GPIO_LED_INVERTED_TABLE
2234 Some GPIO connected LEDs may have inverted polarity in which
2235 case the GPIO high value corresponds to LED off state and
2236 GPIO low value corresponds to LED on state.
2237 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2238 with a list of GPIO LEDs that have inverted polarity.
2240 - CAN Support: CONFIG_CAN_DRIVER
2242 Defining CONFIG_CAN_DRIVER enables CAN driver support
2243 on those systems that support this (optional)
2244 feature, like the TQM8xxL modules.
2246 - I2C Support: CONFIG_SYS_I2C
2248 This enable the NEW i2c subsystem, and will allow you to use
2249 i2c commands at the u-boot command line (as long as you set
2250 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2251 based realtime clock chips or other i2c devices. See
2252 common/cmd_i2c.c for a description of the command line
2255 ported i2c driver to the new framework:
2256 - drivers/i2c/soft_i2c.c:
2257 - activate first bus with CONFIG_SYS_I2C_SOFT define
2258 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2259 for defining speed and slave address
2260 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2261 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2262 for defining speed and slave address
2263 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2264 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2265 for defining speed and slave address
2266 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2267 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2268 for defining speed and slave address
2270 - drivers/i2c/fsl_i2c.c:
2271 - activate i2c driver with CONFIG_SYS_I2C_FSL
2272 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2273 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2274 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2276 - If your board supports a second fsl i2c bus, define
2277 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2278 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2279 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2282 - drivers/i2c/tegra_i2c.c:
2283 - activate this driver with CONFIG_SYS_I2C_TEGRA
2284 - This driver adds 4 i2c buses with a fix speed from
2285 100000 and the slave addr 0!
2287 - drivers/i2c/ppc4xx_i2c.c
2288 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2289 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2290 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2292 - drivers/i2c/i2c_mxc.c
2293 - activate this driver with CONFIG_SYS_I2C_MXC
2294 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2295 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2296 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2297 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2298 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2299 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2300 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2301 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2302 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2303 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2304 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2305 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2306 If those defines are not set, default value is 100000
2307 for speed, and 0 for slave.
2309 - drivers/i2c/rcar_i2c.c:
2310 - activate this driver with CONFIG_SYS_I2C_RCAR
2311 - This driver adds 4 i2c buses
2313 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2314 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2315 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2316 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2317 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2318 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2319 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2320 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2321 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2323 - drivers/i2c/sh_i2c.c:
2324 - activate this driver with CONFIG_SYS_I2C_SH
2325 - This driver adds from 2 to 5 i2c buses
2327 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2328 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2329 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2330 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2331 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2332 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2333 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2334 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2335 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2336 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2337 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2338 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2339 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2341 - drivers/i2c/omap24xx_i2c.c
2342 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2343 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2344 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2345 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2346 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2347 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2348 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2349 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2350 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2351 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2352 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2354 - drivers/i2c/zynq_i2c.c
2355 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2356 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2357 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2359 - drivers/i2c/s3c24x0_i2c.c:
2360 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2361 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2362 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2363 with a fix speed from 100000 and the slave addr 0!
2365 - drivers/i2c/ihs_i2c.c
2366 - activate this driver with CONFIG_SYS_I2C_IHS
2367 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2368 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2369 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2370 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2371 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2372 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2373 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2374 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2375 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2376 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2377 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2378 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2379 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2380 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2381 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2382 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2383 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2384 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2385 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2386 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2387 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2391 CONFIG_SYS_NUM_I2C_BUSES
2392 Hold the number of i2c buses you want to use. If you
2393 don't use/have i2c muxes on your i2c bus, this
2394 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2397 CONFIG_SYS_I2C_DIRECT_BUS
2398 define this, if you don't use i2c muxes on your hardware.
2399 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2402 CONFIG_SYS_I2C_MAX_HOPS
2403 define how many muxes are maximal consecutively connected
2404 on one i2c bus. If you not use i2c muxes, omit this
2407 CONFIG_SYS_I2C_BUSES
2408 hold a list of buses you want to use, only used if
2409 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2410 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2411 CONFIG_SYS_NUM_I2C_BUSES = 9:
2413 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2414 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2415 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2416 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2417 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2418 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2419 {1, {I2C_NULL_HOP}}, \
2420 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2421 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2425 bus 0 on adapter 0 without a mux
2426 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2427 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2428 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2429 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2430 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2431 bus 6 on adapter 1 without a mux
2432 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2433 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2435 If you do not have i2c muxes on your board, omit this define.
2437 - Legacy I2C Support: CONFIG_HARD_I2C
2439 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2440 provides the following compelling advantages:
2442 - more than one i2c adapter is usable
2443 - approved multibus support
2444 - better i2c mux support
2446 ** Please consider updating your I2C driver now. **
2448 These enable legacy I2C serial bus commands. Defining
2449 CONFIG_HARD_I2C will include the appropriate I2C driver
2450 for the selected CPU.
2452 This will allow you to use i2c commands at the u-boot
2453 command line (as long as you set CONFIG_CMD_I2C in
2454 CONFIG_COMMANDS) and communicate with i2c based realtime
2455 clock chips. See common/cmd_i2c.c for a description of the
2456 command line interface.
2458 CONFIG_HARD_I2C selects a hardware I2C controller.
2460 There are several other quantities that must also be
2461 defined when you define CONFIG_HARD_I2C.
2463 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2464 to be the frequency (in Hz) at which you wish your i2c bus
2465 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2466 the CPU's i2c node address).
2468 Now, the u-boot i2c code for the mpc8xx
2469 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2470 and so its address should therefore be cleared to 0 (See,
2471 eg, MPC823e User's Manual p.16-473). So, set
2472 CONFIG_SYS_I2C_SLAVE to 0.
2474 CONFIG_SYS_I2C_INIT_MPC5XXX
2476 When a board is reset during an i2c bus transfer
2477 chips might think that the current transfer is still
2478 in progress. Reset the slave devices by sending start
2479 commands until the slave device responds.
2481 That's all that's required for CONFIG_HARD_I2C.
2483 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2484 then the following macros need to be defined (examples are
2485 from include/configs/lwmon.h):
2489 (Optional). Any commands necessary to enable the I2C
2490 controller or configure ports.
2492 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2496 (Only for MPC8260 CPU). The I/O port to use (the code
2497 assumes both bits are on the same port). Valid values
2498 are 0..3 for ports A..D.
2502 The code necessary to make the I2C data line active
2503 (driven). If the data line is open collector, this
2506 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2510 The code necessary to make the I2C data line tri-stated
2511 (inactive). If the data line is open collector, this
2514 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2518 Code that returns true if the I2C data line is high,
2521 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2525 If <bit> is true, sets the I2C data line high. If it
2526 is false, it clears it (low).
2528 eg: #define I2C_SDA(bit) \
2529 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2530 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2534 If <bit> is true, sets the I2C clock line high. If it
2535 is false, it clears it (low).
2537 eg: #define I2C_SCL(bit) \
2538 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2539 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2543 This delay is invoked four times per clock cycle so this
2544 controls the rate of data transfer. The data rate thus
2545 is 1 / (I2C_DELAY * 4). Often defined to be something
2548 #define I2C_DELAY udelay(2)
2550 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2552 If your arch supports the generic GPIO framework (asm/gpio.h),
2553 then you may alternatively define the two GPIOs that are to be
2554 used as SCL / SDA. Any of the previous I2C_xxx macros will
2555 have GPIO-based defaults assigned to them as appropriate.
2557 You should define these to the GPIO value as given directly to
2558 the generic GPIO functions.
2560 CONFIG_SYS_I2C_INIT_BOARD
2562 When a board is reset during an i2c bus transfer
2563 chips might think that the current transfer is still
2564 in progress. On some boards it is possible to access
2565 the i2c SCLK line directly, either by using the
2566 processor pin as a GPIO or by having a second pin
2567 connected to the bus. If this option is defined a
2568 custom i2c_init_board() routine in boards/xxx/board.c
2569 is run early in the boot sequence.
2571 CONFIG_SYS_I2C_BOARD_LATE_INIT
2573 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2574 defined a custom i2c_board_late_init() routine in
2575 boards/xxx/board.c is run AFTER the operations in i2c_init()
2576 is completed. This callpoint can be used to unreset i2c bus
2577 using CPU i2c controller register accesses for CPUs whose i2c
2578 controller provide such a method. It is called at the end of
2579 i2c_init() to allow i2c_init operations to setup the i2c bus
2580 controller on the CPU (e.g. setting bus speed & slave address).
2582 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2584 This option enables configuration of bi_iic_fast[] flags
2585 in u-boot bd_info structure based on u-boot environment
2586 variable "i2cfast". (see also i2cfast)
2588 CONFIG_I2C_MULTI_BUS
2590 This option allows the use of multiple I2C buses, each of which
2591 must have a controller. At any point in time, only one bus is
2592 active. To switch to a different bus, use the 'i2c dev' command.
2593 Note that bus numbering is zero-based.
2595 CONFIG_SYS_I2C_NOPROBES
2597 This option specifies a list of I2C devices that will be skipped
2598 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2599 is set, specify a list of bus-device pairs. Otherwise, specify
2600 a 1D array of device addresses
2603 #undef CONFIG_I2C_MULTI_BUS
2604 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2606 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2608 #define CONFIG_I2C_MULTI_BUS
2609 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2611 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2613 CONFIG_SYS_SPD_BUS_NUM
2615 If defined, then this indicates the I2C bus number for DDR SPD.
2616 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2618 CONFIG_SYS_RTC_BUS_NUM
2620 If defined, then this indicates the I2C bus number for the RTC.
2621 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2623 CONFIG_SYS_DTT_BUS_NUM
2625 If defined, then this indicates the I2C bus number for the DTT.
2626 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2628 CONFIG_SYS_I2C_DTT_ADDR:
2630 If defined, specifies the I2C address of the DTT device.
2631 If not defined, then U-Boot uses predefined value for
2632 specified DTT device.
2634 CONFIG_SOFT_I2C_READ_REPEATED_START
2636 defining this will force the i2c_read() function in
2637 the soft_i2c driver to perform an I2C repeated start
2638 between writing the address pointer and reading the
2639 data. If this define is omitted the default behaviour
2640 of doing a stop-start sequence will be used. Most I2C
2641 devices can use either method, but some require one or
2644 - SPI Support: CONFIG_SPI
2646 Enables SPI driver (so far only tested with
2647 SPI EEPROM, also an instance works with Crystal A/D and
2648 D/As on the SACSng board)
2652 Enables the driver for SPI controller on SuperH. Currently
2653 only SH7757 is supported.
2657 Enables a software (bit-bang) SPI driver rather than
2658 using hardware support. This is a general purpose
2659 driver that only requires three general I/O port pins
2660 (two outputs, one input) to function. If this is
2661 defined, the board configuration must define several
2662 SPI configuration items (port pins to use, etc). For
2663 an example, see include/configs/sacsng.h.
2667 Enables a hardware SPI driver for general-purpose reads
2668 and writes. As with CONFIG_SOFT_SPI, the board configuration
2669 must define a list of chip-select function pointers.
2670 Currently supported on some MPC8xxx processors. For an
2671 example, see include/configs/mpc8349emds.h.
2675 Enables the driver for the SPI controllers on i.MX and MXC
2676 SoCs. Currently i.MX31/35/51 are supported.
2678 CONFIG_SYS_SPI_MXC_WAIT
2679 Timeout for waiting until spi transfer completed.
2680 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2682 - FPGA Support: CONFIG_FPGA
2684 Enables FPGA subsystem.
2686 CONFIG_FPGA_<vendor>
2688 Enables support for specific chip vendors.
2691 CONFIG_FPGA_<family>
2693 Enables support for FPGA family.
2694 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2698 Specify the number of FPGA devices to support.
2700 CONFIG_CMD_FPGA_LOADMK
2702 Enable support for fpga loadmk command
2704 CONFIG_CMD_FPGA_LOADP
2706 Enable support for fpga loadp command - load partial bitstream
2708 CONFIG_CMD_FPGA_LOADBP
2710 Enable support for fpga loadbp command - load partial bitstream
2713 CONFIG_SYS_FPGA_PROG_FEEDBACK
2715 Enable printing of hash marks during FPGA configuration.
2717 CONFIG_SYS_FPGA_CHECK_BUSY
2719 Enable checks on FPGA configuration interface busy
2720 status by the configuration function. This option
2721 will require a board or device specific function to
2726 If defined, a function that provides delays in the FPGA
2727 configuration driver.
2729 CONFIG_SYS_FPGA_CHECK_CTRLC
2730 Allow Control-C to interrupt FPGA configuration
2732 CONFIG_SYS_FPGA_CHECK_ERROR
2734 Check for configuration errors during FPGA bitfile
2735 loading. For example, abort during Virtex II
2736 configuration if the INIT_B line goes low (which
2737 indicated a CRC error).
2739 CONFIG_SYS_FPGA_WAIT_INIT
2741 Maximum time to wait for the INIT_B line to de-assert
2742 after PROB_B has been de-asserted during a Virtex II
2743 FPGA configuration sequence. The default time is 500
2746 CONFIG_SYS_FPGA_WAIT_BUSY
2748 Maximum time to wait for BUSY to de-assert during
2749 Virtex II FPGA configuration. The default is 5 ms.
2751 CONFIG_SYS_FPGA_WAIT_CONFIG
2753 Time to wait after FPGA configuration. The default is
2756 - Configuration Management:
2759 Some SoCs need special image types (e.g. U-Boot binary
2760 with a special header) as build targets. By defining
2761 CONFIG_BUILD_TARGET in the SoC / board header, this
2762 special image will be automatically built upon calling
2767 If defined, this string will be added to the U-Boot
2768 version information (U_BOOT_VERSION)
2770 - Vendor Parameter Protection:
2772 U-Boot considers the values of the environment
2773 variables "serial#" (Board Serial Number) and
2774 "ethaddr" (Ethernet Address) to be parameters that
2775 are set once by the board vendor / manufacturer, and
2776 protects these variables from casual modification by
2777 the user. Once set, these variables are read-only,
2778 and write or delete attempts are rejected. You can
2779 change this behaviour:
2781 If CONFIG_ENV_OVERWRITE is #defined in your config
2782 file, the write protection for vendor parameters is
2783 completely disabled. Anybody can change or delete
2786 Alternatively, if you define _both_ an ethaddr in the
2787 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2788 Ethernet address is installed in the environment,
2789 which can be changed exactly ONCE by the user. [The
2790 serial# is unaffected by this, i. e. it remains
2793 The same can be accomplished in a more flexible way
2794 for any variable by configuring the type of access
2795 to allow for those variables in the ".flags" variable
2796 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2801 Define this variable to enable the reservation of
2802 "protected RAM", i. e. RAM which is not overwritten
2803 by U-Boot. Define CONFIG_PRAM to hold the number of
2804 kB you want to reserve for pRAM. You can overwrite
2805 this default value by defining an environment
2806 variable "pram" to the number of kB you want to
2807 reserve. Note that the board info structure will
2808 still show the full amount of RAM. If pRAM is
2809 reserved, a new environment variable "mem" will
2810 automatically be defined to hold the amount of
2811 remaining RAM in a form that can be passed as boot
2812 argument to Linux, for instance like that:
2814 setenv bootargs ... mem=\${mem}
2817 This way you can tell Linux not to use this memory,
2818 either, which results in a memory region that will
2819 not be affected by reboots.
2821 *WARNING* If your board configuration uses automatic
2822 detection of the RAM size, you must make sure that
2823 this memory test is non-destructive. So far, the
2824 following board configurations are known to be
2827 IVMS8, IVML24, SPD8xx, TQM8xxL,
2828 HERMES, IP860, RPXlite, LWMON,
2831 - Access to physical memory region (> 4GB)
2832 Some basic support is provided for operations on memory not
2833 normally accessible to U-Boot - e.g. some architectures
2834 support access to more than 4GB of memory on 32-bit
2835 machines using physical address extension or similar.
2836 Define CONFIG_PHYSMEM to access this basic support, which
2837 currently only supports clearing the memory.
2842 Define this variable to stop the system in case of a
2843 fatal error, so that you have to reset it manually.
2844 This is probably NOT a good idea for an embedded
2845 system where you want the system to reboot
2846 automatically as fast as possible, but it may be
2847 useful during development since you can try to debug
2848 the conditions that lead to the situation.
2850 CONFIG_NET_RETRY_COUNT
2852 This variable defines the number of retries for
2853 network operations like ARP, RARP, TFTP, or BOOTP
2854 before giving up the operation. If not defined, a
2855 default value of 5 is used.
2859 Timeout waiting for an ARP reply in milliseconds.
2863 Timeout in milliseconds used in NFS protocol.
2864 If you encounter "ERROR: Cannot umount" in nfs command,
2865 try longer timeout such as
2866 #define CONFIG_NFS_TIMEOUT 10000UL
2868 - Command Interpreter:
2869 CONFIG_AUTO_COMPLETE
2871 Enable auto completion of commands using TAB.
2873 CONFIG_SYS_PROMPT_HUSH_PS2
2875 This defines the secondary prompt string, which is
2876 printed when the command interpreter needs more input
2877 to complete a command. Usually "> ".
2881 In the current implementation, the local variables
2882 space and global environment variables space are
2883 separated. Local variables are those you define by
2884 simply typing `name=value'. To access a local
2885 variable later on, you have write `$name' or
2886 `${name}'; to execute the contents of a variable
2887 directly type `$name' at the command prompt.
2889 Global environment variables are those you use
2890 setenv/printenv to work with. To run a command stored
2891 in such a variable, you need to use the run command,
2892 and you must not use the '$' sign to access them.
2894 To store commands and special characters in a
2895 variable, please use double quotation marks
2896 surrounding the whole text of the variable, instead
2897 of the backslashes before semicolons and special
2900 - Command Line Editing and History:
2901 CONFIG_CMDLINE_EDITING
2903 Enable editing and History functions for interactive
2904 command line input operations
2906 - Default Environment:
2907 CONFIG_EXTRA_ENV_SETTINGS
2909 Define this to contain any number of null terminated
2910 strings (variable = value pairs) that will be part of
2911 the default environment compiled into the boot image.
2913 For example, place something like this in your
2914 board's config file:
2916 #define CONFIG_EXTRA_ENV_SETTINGS \
2920 Warning: This method is based on knowledge about the
2921 internal format how the environment is stored by the
2922 U-Boot code. This is NOT an official, exported
2923 interface! Although it is unlikely that this format
2924 will change soon, there is no guarantee either.
2925 You better know what you are doing here.
2927 Note: overly (ab)use of the default environment is
2928 discouraged. Make sure to check other ways to preset
2929 the environment like the "source" command or the
2932 CONFIG_ENV_VARS_UBOOT_CONFIG
2934 Define this in order to add variables describing the
2935 U-Boot build configuration to the default environment.
2936 These will be named arch, cpu, board, vendor, and soc.
2938 Enabling this option will cause the following to be defined:
2946 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2948 Define this in order to add variables describing certain
2949 run-time determined information about the hardware to the
2950 environment. These will be named board_name, board_rev.
2952 CONFIG_DELAY_ENVIRONMENT
2954 Normally the environment is loaded when the board is
2955 initialised so that it is available to U-Boot. This inhibits
2956 that so that the environment is not available until
2957 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2958 this is instead controlled by the value of
2959 /config/load-environment.
2961 - Parallel Flash support:
2964 Traditionally U-boot was run on systems with parallel NOR
2965 flash. This option is used to disable support for parallel NOR
2966 flash. This option should be defined if the board does not have
2969 If this option is not defined one of the generic flash drivers
2970 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2971 selected or the board must provide an implementation of the
2972 flash API (see include/flash.h).
2974 - DataFlash Support:
2975 CONFIG_HAS_DATAFLASH
2977 Defining this option enables DataFlash features and
2978 allows to read/write in Dataflash via the standard
2981 - Serial Flash support
2984 Defining this option enables SPI flash commands
2985 'sf probe/read/write/erase/update'.
2987 Usage requires an initial 'probe' to define the serial
2988 flash parameters, followed by read/write/erase/update
2991 The following defaults may be provided by the platform
2992 to handle the common case when only a single serial
2993 flash is present on the system.
2995 CONFIG_SF_DEFAULT_BUS Bus identifier
2996 CONFIG_SF_DEFAULT_CS Chip-select
2997 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2998 CONFIG_SF_DEFAULT_SPEED in Hz
3002 Define this option to include a destructive SPI flash
3005 CONFIG_SF_DUAL_FLASH Dual flash memories
3007 Define this option to use dual flash support where two flash
3008 memories can be connected with a given cs line.
3009 Currently Xilinx Zynq qspi supports these type of connections.
3011 - SystemACE Support:
3014 Adding this option adds support for Xilinx SystemACE
3015 chips attached via some sort of local bus. The address
3016 of the chip must also be defined in the
3017 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3019 #define CONFIG_SYSTEMACE
3020 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3022 When SystemACE support is added, the "ace" device type
3023 becomes available to the fat commands, i.e. fatls.
3025 - TFTP Fixed UDP Port:
3028 If this is defined, the environment variable tftpsrcp
3029 is used to supply the TFTP UDP source port value.
3030 If tftpsrcp isn't defined, the normal pseudo-random port
3031 number generator is used.
3033 Also, the environment variable tftpdstp is used to supply
3034 the TFTP UDP destination port value. If tftpdstp isn't
3035 defined, the normal port 69 is used.
3037 The purpose for tftpsrcp is to allow a TFTP server to
3038 blindly start the TFTP transfer using the pre-configured
3039 target IP address and UDP port. This has the effect of
3040 "punching through" the (Windows XP) firewall, allowing
3041 the remainder of the TFTP transfer to proceed normally.
3042 A better solution is to properly configure the firewall,
3043 but sometimes that is not allowed.
3048 This enables a generic 'hash' command which can produce
3049 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3053 Enable the hash verify command (hash -v). This adds to code
3056 CONFIG_SHA1 - This option enables support of hashing using SHA1
3057 algorithm. The hash is calculated in software.
3058 CONFIG_SHA256 - This option enables support of hashing using
3059 SHA256 algorithm. The hash is calculated in software.
3060 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3061 for SHA1/SHA256 hashing.
3062 This affects the 'hash' command and also the
3063 hash_lookup_algo() function.
3064 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3065 hardware-acceleration for SHA1/SHA256 progressive hashing.
3066 Data can be streamed in a block at a time and the hashing
3067 is performed in hardware.
3069 Note: There is also a sha1sum command, which should perhaps
3070 be deprecated in favour of 'hash sha1'.
3072 - Freescale i.MX specific commands:
3073 CONFIG_CMD_HDMIDETECT
3074 This enables 'hdmidet' command which returns true if an
3075 HDMI monitor is detected. This command is i.MX 6 specific.
3078 This enables the 'bmode' (bootmode) command for forcing
3079 a boot from specific media.
3081 This is useful for forcing the ROM's usb downloader to
3082 activate upon a watchdog reset which is nice when iterating
3083 on U-Boot. Using the reset button or running bmode normal
3084 will set it back to normal. This command currently
3085 supports i.MX53 and i.MX6.
3090 This enables the RSA algorithm used for FIT image verification
3091 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3093 The Modular Exponentiation algorithm in RSA is implemented using
3094 driver model. So CONFIG_DM needs to be enabled by default for this
3095 library to function.
3097 The signing part is build into mkimage regardless of this
3098 option. The software based modular exponentiation is built into
3099 mkimage irrespective of this option.
3101 - bootcount support:
3102 CONFIG_BOOTCOUNT_LIMIT
3104 This enables the bootcounter support, see:
3105 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3108 enable special bootcounter support on at91sam9xe based boards.
3110 enable special bootcounter support on blackfin based boards.
3112 enable special bootcounter support on da850 based boards.
3113 CONFIG_BOOTCOUNT_RAM
3114 enable support for the bootcounter in RAM
3115 CONFIG_BOOTCOUNT_I2C
3116 enable support for the bootcounter on an i2c (like RTC) device.
3117 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3118 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3120 CONFIG_BOOTCOUNT_ALEN = address len
3122 - Show boot progress:
3123 CONFIG_SHOW_BOOT_PROGRESS
3125 Defining this option allows to add some board-
3126 specific code (calling a user-provided function
3127 "show_boot_progress(int)") that enables you to show
3128 the system's boot progress on some display (for
3129 example, some LED's) on your board. At the moment,
3130 the following checkpoints are implemented:
3133 Legacy uImage format:
3136 1 common/cmd_bootm.c before attempting to boot an image
3137 -1 common/cmd_bootm.c Image header has bad magic number
3138 2 common/cmd_bootm.c Image header has correct magic number
3139 -2 common/cmd_bootm.c Image header has bad checksum
3140 3 common/cmd_bootm.c Image header has correct checksum
3141 -3 common/cmd_bootm.c Image data has bad checksum
3142 4 common/cmd_bootm.c Image data has correct checksum
3143 -4 common/cmd_bootm.c Image is for unsupported architecture
3144 5 common/cmd_bootm.c Architecture check OK
3145 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3146 6 common/cmd_bootm.c Image Type check OK
3147 -6 common/cmd_bootm.c gunzip uncompression error
3148 -7 common/cmd_bootm.c Unimplemented compression type
3149 7 common/cmd_bootm.c Uncompression OK
3150 8 common/cmd_bootm.c No uncompress/copy overwrite error
3151 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3153 9 common/image.c Start initial ramdisk verification
3154 -10 common/image.c Ramdisk header has bad magic number
3155 -11 common/image.c Ramdisk header has bad checksum
3156 10 common/image.c Ramdisk header is OK
3157 -12 common/image.c Ramdisk data has bad checksum
3158 11 common/image.c Ramdisk data has correct checksum
3159 12 common/image.c Ramdisk verification complete, start loading
3160 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3161 13 common/image.c Start multifile image verification
3162 14 common/image.c No initial ramdisk, no multifile, continue.
3164 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3166 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3167 -31 post/post.c POST test failed, detected by post_output_backlog()
3168 -32 post/post.c POST test failed, detected by post_run_single()
3170 34 common/cmd_doc.c before loading a Image from a DOC device
3171 -35 common/cmd_doc.c Bad usage of "doc" command
3172 35 common/cmd_doc.c correct usage of "doc" command
3173 -36 common/cmd_doc.c No boot device
3174 36 common/cmd_doc.c correct boot device
3175 -37 common/cmd_doc.c Unknown Chip ID on boot device
3176 37 common/cmd_doc.c correct chip ID found, device available
3177 -38 common/cmd_doc.c Read Error on boot device
3178 38 common/cmd_doc.c reading Image header from DOC device OK
3179 -39 common/cmd_doc.c Image header has bad magic number
3180 39 common/cmd_doc.c Image header has correct magic number
3181 -40 common/cmd_doc.c Error reading Image from DOC device
3182 40 common/cmd_doc.c Image header has correct magic number
3183 41 common/cmd_ide.c before loading a Image from a IDE device
3184 -42 common/cmd_ide.c Bad usage of "ide" command
3185 42 common/cmd_ide.c correct usage of "ide" command
3186 -43 common/cmd_ide.c No boot device
3187 43 common/cmd_ide.c boot device found
3188 -44 common/cmd_ide.c Device not available
3189 44 common/cmd_ide.c Device available
3190 -45 common/cmd_ide.c wrong partition selected
3191 45 common/cmd_ide.c partition selected
3192 -46 common/cmd_ide.c Unknown partition table
3193 46 common/cmd_ide.c valid partition table found
3194 -47 common/cmd_ide.c Invalid partition type
3195 47 common/cmd_ide.c correct partition type
3196 -48 common/cmd_ide.c Error reading Image Header on boot device
3197 48 common/cmd_ide.c reading Image Header from IDE device OK
3198 -49 common/cmd_ide.c Image header has bad magic number
3199 49 common/cmd_ide.c Image header has correct magic number
3200 -50 common/cmd_ide.c Image header has bad checksum
3201 50 common/cmd_ide.c Image header has correct checksum
3202 -51 common/cmd_ide.c Error reading Image from IDE device
3203 51 common/cmd_ide.c reading Image from IDE device OK
3204 52 common/cmd_nand.c before loading a Image from a NAND device
3205 -53 common/cmd_nand.c Bad usage of "nand" command
3206 53 common/cmd_nand.c correct usage of "nand" command
3207 -54 common/cmd_nand.c No boot device
3208 54 common/cmd_nand.c boot device found
3209 -55 common/cmd_nand.c Unknown Chip ID on boot device
3210 55 common/cmd_nand.c correct chip ID found, device available
3211 -56 common/cmd_nand.c Error reading Image Header on boot device
3212 56 common/cmd_nand.c reading Image Header from NAND device OK
3213 -57 common/cmd_nand.c Image header has bad magic number
3214 57 common/cmd_nand.c Image header has correct magic number
3215 -58 common/cmd_nand.c Error reading Image from NAND device
3216 58 common/cmd_nand.c reading Image from NAND device OK
3218 -60 common/env_common.c Environment has a bad CRC, using default
3220 64 net/eth.c starting with Ethernet configuration.
3221 -64 net/eth.c no Ethernet found.
3222 65 net/eth.c Ethernet found.
3224 -80 common/cmd_net.c usage wrong
3225 80 common/cmd_net.c before calling net_loop()
3226 -81 common/cmd_net.c some error in net_loop() occurred
3227 81 common/cmd_net.c net_loop() back without error
3228 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3229 82 common/cmd_net.c trying automatic boot
3230 83 common/cmd_net.c running "source" command
3231 -83 common/cmd_net.c some error in automatic boot or "source" command
3232 84 common/cmd_net.c end without errors
3237 100 common/cmd_bootm.c Kernel FIT Image has correct format
3238 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3239 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3240 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3241 102 common/cmd_bootm.c Kernel unit name specified
3242 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3243 103 common/cmd_bootm.c Found configuration node
3244 104 common/cmd_bootm.c Got kernel subimage node offset
3245 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3246 105 common/cmd_bootm.c Kernel subimage hash verification OK
3247 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3248 106 common/cmd_bootm.c Architecture check OK
3249 -106 common/cmd_bootm.c Kernel subimage has wrong type
3250 107 common/cmd_bootm.c Kernel subimage type OK
3251 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3252 108 common/cmd_bootm.c Got kernel subimage data/size
3253 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3254 -109 common/cmd_bootm.c Can't get kernel subimage type
3255 -110 common/cmd_bootm.c Can't get kernel subimage comp
3256 -111 common/cmd_bootm.c Can't get kernel subimage os
3257 -112 common/cmd_bootm.c Can't get kernel subimage load address
3258 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3260 120 common/image.c Start initial ramdisk verification
3261 -120 common/image.c Ramdisk FIT image has incorrect format
3262 121 common/image.c Ramdisk FIT image has correct format
3263 122 common/image.c No ramdisk subimage unit name, using configuration
3264 -122 common/image.c Can't get configuration for ramdisk subimage
3265 123 common/image.c Ramdisk unit name specified
3266 -124 common/image.c Can't get ramdisk subimage node offset
3267 125 common/image.c Got ramdisk subimage node offset
3268 -125 common/image.c Ramdisk subimage hash verification failed
3269 126 common/image.c Ramdisk subimage hash verification OK
3270 -126 common/image.c Ramdisk subimage for unsupported architecture
3271 127 common/image.c Architecture check OK
3272 -127 common/image.c Can't get ramdisk subimage data/size
3273 128 common/image.c Got ramdisk subimage data/size
3274 129 common/image.c Can't get ramdisk load address
3275 -129 common/image.c Got ramdisk load address
3277 -130 common/cmd_doc.c Incorrect FIT image format
3278 131 common/cmd_doc.c FIT image format OK
3280 -140 common/cmd_ide.c Incorrect FIT image format
3281 141 common/cmd_ide.c FIT image format OK
3283 -150 common/cmd_nand.c Incorrect FIT image format
3284 151 common/cmd_nand.c FIT image format OK
3286 - legacy image format:
3287 CONFIG_IMAGE_FORMAT_LEGACY
3288 enables the legacy image format support in U-Boot.
3291 enabled if CONFIG_FIT_SIGNATURE is not defined.
3293 CONFIG_DISABLE_IMAGE_LEGACY
3294 disable the legacy image format
3296 This define is introduced, as the legacy image format is
3297 enabled per default for backward compatibility.
3299 - FIT image support:
3301 Enable support for the FIT uImage format.
3303 CONFIG_FIT_BEST_MATCH
3304 When no configuration is explicitly selected, default to the
3305 one whose fdt's compatibility field best matches that of
3306 U-Boot itself. A match is considered "best" if it matches the
3307 most specific compatibility entry of U-Boot's fdt's root node.
3308 The order of entries in the configuration's fdt is ignored.
3310 CONFIG_FIT_SIGNATURE
3311 This option enables signature verification of FIT uImages,
3312 using a hash signed and verified using RSA. If
3313 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3314 hashing is available using hardware, RSA library will use it.
3315 See doc/uImage.FIT/signature.txt for more details.
3317 WARNING: When relying on signed FIT images with required
3318 signature check the legacy image format is default
3319 disabled. If a board need legacy image format support
3320 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3322 CONFIG_FIT_DISABLE_SHA256
3323 Supporting SHA256 hashes has quite an impact on binary size.
3324 For constrained systems sha256 hash support can be disabled
3327 - Standalone program support:
3328 CONFIG_STANDALONE_LOAD_ADDR
3330 This option defines a board specific value for the
3331 address where standalone program gets loaded, thus
3332 overwriting the architecture dependent default
3335 - Frame Buffer Address:
3338 Define CONFIG_FB_ADDR if you want to use specific
3339 address for frame buffer. This is typically the case
3340 when using a graphics controller has separate video
3341 memory. U-Boot will then place the frame buffer at
3342 the given address instead of dynamically reserving it
3343 in system RAM by calling lcd_setmem(), which grabs
3344 the memory for the frame buffer depending on the
3345 configured panel size.
3347 Please see board_init_f function.
3349 - Automatic software updates via TFTP server
3351 CONFIG_UPDATE_TFTP_CNT_MAX
3352 CONFIG_UPDATE_TFTP_MSEC_MAX
3354 These options enable and control the auto-update feature;
3355 for a more detailed description refer to doc/README.update.
3357 - MTD Support (mtdparts command, UBI support)
3360 Adds the MTD device infrastructure from the Linux kernel.
3361 Needed for mtdparts command support.
3363 CONFIG_MTD_PARTITIONS
3365 Adds the MTD partitioning infrastructure from the Linux
3366 kernel. Needed for UBI support.
3371 Adds commands for interacting with MTD partitions formatted
3372 with the UBI flash translation layer
3374 Requires also defining CONFIG_RBTREE
3376 CONFIG_UBI_SILENCE_MSG
3378 Make the verbose messages from UBI stop printing. This leaves
3379 warnings and errors enabled.
3382 CONFIG_MTD_UBI_WL_THRESHOLD
3383 This parameter defines the maximum difference between the highest
3384 erase counter value and the lowest erase counter value of eraseblocks
3385 of UBI devices. When this threshold is exceeded, UBI starts performing
3386 wear leveling by means of moving data from eraseblock with low erase
3387 counter to eraseblocks with high erase counter.
3389 The default value should be OK for SLC NAND flashes, NOR flashes and
3390 other flashes which have eraseblock life-cycle 100000 or more.
3391 However, in case of MLC NAND flashes which typically have eraseblock
3392 life-cycle less than 10000, the threshold should be lessened (e.g.,
3393 to 128 or 256, although it does not have to be power of 2).
3397 CONFIG_MTD_UBI_BEB_LIMIT
3398 This option specifies the maximum bad physical eraseblocks UBI
3399 expects on the MTD device (per 1024 eraseblocks). If the
3400 underlying flash does not admit of bad eraseblocks (e.g. NOR
3401 flash), this value is ignored.
3403 NAND datasheets often specify the minimum and maximum NVM
3404 (Number of Valid Blocks) for the flashes' endurance lifetime.
3405 The maximum expected bad eraseblocks per 1024 eraseblocks
3406 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3407 which gives 20 for most NANDs (MaxNVB is basically the total
3408 count of eraseblocks on the chip).
3410 To put it differently, if this value is 20, UBI will try to
3411 reserve about 1.9% of physical eraseblocks for bad blocks
3412 handling. And that will be 1.9% of eraseblocks on the entire
3413 NAND chip, not just the MTD partition UBI attaches. This means
3414 that if you have, say, a NAND flash chip admits maximum 40 bad
3415 eraseblocks, and it is split on two MTD partitions of the same
3416 size, UBI will reserve 40 eraseblocks when attaching a
3421 CONFIG_MTD_UBI_FASTMAP
3422 Fastmap is a mechanism which allows attaching an UBI device
3423 in nearly constant time. Instead of scanning the whole MTD device it
3424 only has to locate a checkpoint (called fastmap) on the device.
3425 The on-flash fastmap contains all information needed to attach
3426 the device. Using fastmap makes only sense on large devices where
3427 attaching by scanning takes long. UBI will not automatically install
3428 a fastmap on old images, but you can set the UBI parameter
3429 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3430 that fastmap-enabled images are still usable with UBI implementations
3431 without fastmap support. On typical flash devices the whole fastmap
3432 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3434 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3435 Set this parameter to enable fastmap automatically on images
3439 CONFIG_MTD_UBI_FM_DEBUG
3440 Enable UBI fastmap debug
3446 Adds commands for interacting with UBI volumes formatted as
3447 UBIFS. UBIFS is read-only in u-boot.
3449 Requires UBI support as well as CONFIG_LZO
3451 CONFIG_UBIFS_SILENCE_MSG
3453 Make the verbose messages from UBIFS stop printing. This leaves
3454 warnings and errors enabled.
3458 Enable building of SPL globally.
3461 LDSCRIPT for linking the SPL binary.
3463 CONFIG_SPL_MAX_FOOTPRINT
3464 Maximum size in memory allocated to the SPL, BSS included.
3465 When defined, the linker checks that the actual memory
3466 used by SPL from _start to __bss_end does not exceed it.
3467 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3468 must not be both defined at the same time.
3471 Maximum size of the SPL image (text, data, rodata, and
3472 linker lists sections), BSS excluded.
3473 When defined, the linker checks that the actual size does
3476 CONFIG_SPL_TEXT_BASE
3477 TEXT_BASE for linking the SPL binary.
3479 CONFIG_SPL_RELOC_TEXT_BASE
3480 Address to relocate to. If unspecified, this is equal to
3481 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3483 CONFIG_SPL_BSS_START_ADDR
3484 Link address for the BSS within the SPL binary.
3486 CONFIG_SPL_BSS_MAX_SIZE
3487 Maximum size in memory allocated to the SPL BSS.
3488 When defined, the linker checks that the actual memory used
3489 by SPL from __bss_start to __bss_end does not exceed it.
3490 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3491 must not be both defined at the same time.
3494 Adress of the start of the stack SPL will use
3496 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3497 When defined, SPL will panic() if the image it has
3498 loaded does not have a signature.
3499 Defining this is useful when code which loads images
3500 in SPL cannot guarantee that absolutely all read errors
3502 An example is the LPC32XX MLC NAND driver, which will
3503 consider that a completely unreadable NAND block is bad,
3504 and thus should be skipped silently.
3506 CONFIG_SPL_RELOC_STACK
3507 Adress of the start of the stack SPL will use after
3508 relocation. If unspecified, this is equal to
3511 CONFIG_SYS_SPL_MALLOC_START
3512 Starting address of the malloc pool used in SPL.
3513 When this option is set the full malloc is used in SPL and
3514 it is set up by spl_init() and before that, the simple malloc()
3515 can be used if CONFIG_SYS_MALLOC_F is defined.
3517 CONFIG_SYS_SPL_MALLOC_SIZE
3518 The size of the malloc pool used in SPL.
3520 CONFIG_SPL_FRAMEWORK
3521 Enable the SPL framework under common/. This framework
3522 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3523 NAND loading of the Linux Kernel.
3526 Enable booting directly to an OS from SPL.
3527 See also: doc/README.falcon
3529 CONFIG_SPL_DISPLAY_PRINT
3530 For ARM, enable an optional function to print more information
3531 about the running system.
3533 CONFIG_SPL_INIT_MINIMAL
3534 Arch init code should be built for a very small image
3536 CONFIG_SPL_LIBCOMMON_SUPPORT
3537 Support for common/libcommon.o in SPL binary
3539 CONFIG_SPL_LIBDISK_SUPPORT
3540 Support for disk/libdisk.o in SPL binary
3542 CONFIG_SPL_I2C_SUPPORT
3543 Support for drivers/i2c/libi2c.o in SPL binary
3545 CONFIG_SPL_GPIO_SUPPORT
3546 Support for drivers/gpio/libgpio.o in SPL binary
3548 CONFIG_SPL_MMC_SUPPORT
3549 Support for drivers/mmc/libmmc.o in SPL binary
3551 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3552 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3553 Address and partition on the MMC to load U-Boot from
3554 when the MMC is being used in raw mode.
3556 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3557 Partition on the MMC to load U-Boot from when the MMC is being
3560 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3561 Sector to load kernel uImage from when MMC is being
3562 used in raw mode (for Falcon mode)
3564 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3565 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3566 Sector and number of sectors to load kernel argument
3567 parameters from when MMC is being used in raw mode
3570 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3571 Partition on the MMC to load U-Boot from when the MMC is being
3574 CONFIG_SPL_FAT_SUPPORT
3575 Support for fs/fat/libfat.o in SPL binary
3577 CONFIG_SPL_EXT_SUPPORT
3578 Support for EXT filesystem in SPL binary
3580 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3581 Filename to read to load U-Boot when reading from filesystem
3583 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3584 Filename to read to load kernel uImage when reading
3585 from filesystem (for Falcon mode)
3587 CONFIG_SPL_FS_LOAD_ARGS_NAME
3588 Filename to read to load kernel argument parameters
3589 when reading from filesystem (for Falcon mode)
3591 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3592 Set this for NAND SPL on PPC mpc83xx targets, so that
3593 start.S waits for the rest of the SPL to load before
3594 continuing (the hardware starts execution after just
3595 loading the first page rather than the full 4K).
3597 CONFIG_SPL_SKIP_RELOCATE
3598 Avoid SPL relocation
3600 CONFIG_SPL_NAND_BASE
3601 Include nand_base.c in the SPL. Requires
3602 CONFIG_SPL_NAND_DRIVERS.
3604 CONFIG_SPL_NAND_DRIVERS
3605 SPL uses normal NAND drivers, not minimal drivers.
3608 Include standard software ECC in the SPL
3610 CONFIG_SPL_NAND_SIMPLE
3611 Support for NAND boot using simple NAND drivers that
3612 expose the cmd_ctrl() interface.
3614 CONFIG_SPL_MTD_SUPPORT
3615 Support for the MTD subsystem within SPL. Useful for
3616 environment on NAND support within SPL.
3618 CONFIG_SPL_NAND_RAW_ONLY
3619 Support to boot only raw u-boot.bin images. Use this only
3620 if you need to save space.
3622 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3623 Set for the SPL on PPC mpc8xxx targets, support for
3624 drivers/ddr/fsl/libddr.o in SPL binary.
3626 CONFIG_SPL_COMMON_INIT_DDR
3627 Set for common ddr init with serial presence detect in
3630 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3631 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3632 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3633 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3634 CONFIG_SYS_NAND_ECCBYTES
3635 Defines the size and behavior of the NAND that SPL uses
3638 CONFIG_SPL_NAND_BOOT
3639 Add support NAND boot
3641 CONFIG_SYS_NAND_U_BOOT_OFFS
3642 Location in NAND to read U-Boot from
3644 CONFIG_SYS_NAND_U_BOOT_DST
3645 Location in memory to load U-Boot to
3647 CONFIG_SYS_NAND_U_BOOT_SIZE
3648 Size of image to load
3650 CONFIG_SYS_NAND_U_BOOT_START
3651 Entry point in loaded image to jump to
3653 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3654 Define this if you need to first read the OOB and then the
3655 data. This is used, for example, on davinci platforms.
3657 CONFIG_SPL_OMAP3_ID_NAND
3658 Support for an OMAP3-specific set of functions to return the
3659 ID and MFR of the first attached NAND chip, if present.
3661 CONFIG_SPL_SERIAL_SUPPORT
3662 Support for drivers/serial/libserial.o in SPL binary
3664 CONFIG_SPL_SPI_FLASH_SUPPORT
3665 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3667 CONFIG_SPL_SPI_SUPPORT
3668 Support for drivers/spi/libspi.o in SPL binary
3670 CONFIG_SPL_RAM_DEVICE
3671 Support for running image already present in ram, in SPL binary
3673 CONFIG_SPL_LIBGENERIC_SUPPORT
3674 Support for lib/libgeneric.o in SPL binary
3676 CONFIG_SPL_ENV_SUPPORT
3677 Support for the environment operating in SPL binary
3679 CONFIG_SPL_NET_SUPPORT
3680 Support for the net/libnet.o in SPL binary.
3681 It conflicts with SPL env from storage medium specified by
3682 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3685 Image offset to which the SPL should be padded before appending
3686 the SPL payload. By default, this is defined as
3687 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3688 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3689 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3692 Final target image containing SPL and payload. Some SPLs
3693 use an arch-specific makefile fragment instead, for
3694 example if more than one image needs to be produced.
3696 CONFIG_FIT_SPL_PRINT
3697 Printing information about a FIT image adds quite a bit of
3698 code to SPL. So this is normally disabled in SPL. Use this
3699 option to re-enable it. This will affect the output of the
3700 bootm command when booting a FIT image.
3704 Enable building of TPL globally.
3707 Image offset to which the TPL should be padded before appending
3708 the TPL payload. By default, this is defined as
3709 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3710 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3711 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3716 [so far only for SMDK2400 boards]
3718 - Modem support enable:
3719 CONFIG_MODEM_SUPPORT
3721 - RTS/CTS Flow control enable:
3724 - Modem debug support:
3725 CONFIG_MODEM_SUPPORT_DEBUG
3727 Enables debugging stuff (char screen[1024], dbg())
3728 for modem support. Useful only with BDI2000.
3730 - Interrupt support (PPC):
3732 There are common interrupt_init() and timer_interrupt()
3733 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3734 for CPU specific initialization. interrupt_init_cpu()
3735 should set decrementer_count to appropriate value. If
3736 CPU resets decrementer automatically after interrupt
3737 (ppc4xx) it should set decrementer_count to zero.
3738 timer_interrupt() calls timer_interrupt_cpu() for CPU
3739 specific handling. If board has watchdog / status_led
3740 / other_activity_monitor it works automatically from
3741 general timer_interrupt().
3745 In the target system modem support is enabled when a
3746 specific key (key combination) is pressed during
3747 power-on. Otherwise U-Boot will boot normally
3748 (autoboot). The key_pressed() function is called from
3749 board_init(). Currently key_pressed() is a dummy
3750 function, returning 1 and thus enabling modem
3753 If there are no modem init strings in the
3754 environment, U-Boot proceed to autoboot; the
3755 previous output (banner, info printfs) will be
3758 See also: doc/README.Modem
3760 Board initialization settings:
3761 ------------------------------
3763 During Initialization u-boot calls a number of board specific functions
3764 to allow the preparation of board specific prerequisites, e.g. pin setup
3765 before drivers are initialized. To enable these callbacks the
3766 following configuration macros have to be defined. Currently this is
3767 architecture specific, so please check arch/your_architecture/lib/board.c
3768 typically in board_init_f() and board_init_r().
3770 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3771 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3772 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3773 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3775 Configuration Settings:
3776 -----------------------
3778 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3779 Optionally it can be defined to support 64-bit memory commands.
3781 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3782 undefine this when you're short of memory.
3784 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3785 width of the commands listed in the 'help' command output.
3787 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3788 prompt for user input.
3790 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3792 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3794 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3796 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3797 the application (usually a Linux kernel) when it is
3800 - CONFIG_SYS_BAUDRATE_TABLE:
3801 List of legal baudrate settings for this board.
3803 - CONFIG_SYS_CONSOLE_INFO_QUIET
3804 Suppress display of console information at boot.
3806 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3807 If the board specific function
3808 extern int overwrite_console (void);
3809 returns 1, the stdin, stderr and stdout are switched to the
3810 serial port, else the settings in the environment are used.
3812 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3813 Enable the call to overwrite_console().
3815 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3816 Enable overwrite of previous console environment settings.
3818 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3819 Begin and End addresses of the area used by the
3822 - CONFIG_SYS_ALT_MEMTEST:
3823 Enable an alternate, more extensive memory test.
3825 - CONFIG_SYS_MEMTEST_SCRATCH:
3826 Scratch address used by the alternate memory test
3827 You only need to set this if address zero isn't writeable
3829 - CONFIG_SYS_MEM_RESERVE_SECURE
3830 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3831 is substracted from total RAM and won't be reported to OS.
3832 This memory can be used as secure memory. A variable
3833 gd->secure_ram is used to track the location. In systems
3834 the RAM base is not zero, or RAM is divided into banks,
3835 this variable needs to be recalcuated to get the address.
3837 - CONFIG_SYS_MEM_TOP_HIDE:
3838 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3839 this specified memory area will get subtracted from the top
3840 (end) of RAM and won't get "touched" at all by U-Boot. By
3841 fixing up gd->ram_size the Linux kernel should gets passed
3842 the now "corrected" memory size and won't touch it either.
3843 This should work for arch/ppc and arch/powerpc. Only Linux
3844 board ports in arch/powerpc with bootwrapper support that
3845 recalculate the memory size from the SDRAM controller setup
3846 will have to get fixed in Linux additionally.
3848 This option can be used as a workaround for the 440EPx/GRx
3849 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3852 WARNING: Please make sure that this value is a multiple of
3853 the Linux page size (normally 4k). If this is not the case,
3854 then the end address of the Linux memory will be located at a
3855 non page size aligned address and this could cause major
3858 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3859 Enable temporary baudrate change while serial download
3861 - CONFIG_SYS_SDRAM_BASE:
3862 Physical start address of SDRAM. _Must_ be 0 here.
3864 - CONFIG_SYS_MBIO_BASE:
3865 Physical start address of Motherboard I/O (if using a
3868 - CONFIG_SYS_FLASH_BASE:
3869 Physical start address of Flash memory.
3871 - CONFIG_SYS_MONITOR_BASE:
3872 Physical start address of boot monitor code (set by
3873 make config files to be same as the text base address
3874 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3875 CONFIG_SYS_FLASH_BASE when booting from flash.
3877 - CONFIG_SYS_MONITOR_LEN:
3878 Size of memory reserved for monitor code, used to
3879 determine _at_compile_time_ (!) if the environment is
3880 embedded within the U-Boot image, or in a separate
3883 - CONFIG_SYS_MALLOC_LEN:
3884 Size of DRAM reserved for malloc() use.
3886 - CONFIG_SYS_MALLOC_F_LEN
3887 Size of the malloc() pool for use before relocation. If
3888 this is defined, then a very simple malloc() implementation
3889 will become available before relocation. The address is just
3890 below the global data, and the stack is moved down to make
3893 This feature allocates regions with increasing addresses
3894 within the region. calloc() is supported, but realloc()
3895 is not available. free() is supported but does nothing.
3896 The memory will be freed (or in fact just forgotten) when
3897 U-Boot relocates itself.
3899 Pre-relocation malloc() is only supported on ARM and sandbox
3900 at present but is fairly easy to enable for other archs.
3902 - CONFIG_SYS_MALLOC_SIMPLE
3903 Provides a simple and small malloc() and calloc() for those
3904 boards which do not use the full malloc in SPL (which is
3905 enabled with CONFIG_SYS_SPL_MALLOC_START).
3907 - CONFIG_SYS_NONCACHED_MEMORY:
3908 Size of non-cached memory area. This area of memory will be
3909 typically located right below the malloc() area and mapped
3910 uncached in the MMU. This is useful for drivers that would
3911 otherwise require a lot of explicit cache maintenance. For
3912 some drivers it's also impossible to properly maintain the
3913 cache. For example if the regions that need to be flushed
3914 are not a multiple of the cache-line size, *and* padding
3915 cannot be allocated between the regions to align them (i.e.
3916 if the HW requires a contiguous array of regions, and the
3917 size of each region is not cache-aligned), then a flush of
3918 one region may result in overwriting data that hardware has
3919 written to another region in the same cache-line. This can
3920 happen for example in network drivers where descriptors for
3921 buffers are typically smaller than the CPU cache-line (e.g.
3922 16 bytes vs. 32 or 64 bytes).
3924 Non-cached memory is only supported on 32-bit ARM at present.
3926 - CONFIG_SYS_BOOTM_LEN:
3927 Normally compressed uImages are limited to an
3928 uncompressed size of 8 MBytes. If this is not enough,
3929 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3930 to adjust this setting to your needs.
3932 - CONFIG_SYS_BOOTMAPSZ:
3933 Maximum size of memory mapped by the startup code of
3934 the Linux kernel; all data that must be processed by
3935 the Linux kernel (bd_info, boot arguments, FDT blob if
3936 used) must be put below this limit, unless "bootm_low"
3937 environment variable is defined and non-zero. In such case
3938 all data for the Linux kernel must be between "bootm_low"
3939 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3940 variable "bootm_mapsize" will override the value of
3941 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3942 then the value in "bootm_size" will be used instead.
3944 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3945 Enable initrd_high functionality. If defined then the
3946 initrd_high feature is enabled and the bootm ramdisk subcommand
3949 - CONFIG_SYS_BOOT_GET_CMDLINE:
3950 Enables allocating and saving kernel cmdline in space between
3951 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3953 - CONFIG_SYS_BOOT_GET_KBD:
3954 Enables allocating and saving a kernel copy of the bd_info in
3955 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3957 - CONFIG_SYS_MAX_FLASH_BANKS:
3958 Max number of Flash memory banks
3960 - CONFIG_SYS_MAX_FLASH_SECT:
3961 Max number of sectors on a Flash chip
3963 - CONFIG_SYS_FLASH_ERASE_TOUT:
3964 Timeout for Flash erase operations (in ms)
3966 - CONFIG_SYS_FLASH_WRITE_TOUT:
3967 Timeout for Flash write operations (in ms)
3969 - CONFIG_SYS_FLASH_LOCK_TOUT
3970 Timeout for Flash set sector lock bit operation (in ms)
3972 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3973 Timeout for Flash clear lock bits operation (in ms)
3975 - CONFIG_SYS_FLASH_PROTECTION
3976 If defined, hardware flash sectors protection is used
3977 instead of U-Boot software protection.
3979 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3981 Enable TFTP transfers directly to flash memory;
3982 without this option such a download has to be
3983 performed in two steps: (1) download to RAM, and (2)
3984 copy from RAM to flash.
3986 The two-step approach is usually more reliable, since
3987 you can check if the download worked before you erase
3988 the flash, but in some situations (when system RAM is
3989 too limited to allow for a temporary copy of the
3990 downloaded image) this option may be very useful.
3992 - CONFIG_SYS_FLASH_CFI:
3993 Define if the flash driver uses extra elements in the
3994 common flash structure for storing flash geometry.
3996 - CONFIG_FLASH_CFI_DRIVER
3997 This option also enables the building of the cfi_flash driver
3998 in the drivers directory
4000 - CONFIG_FLASH_CFI_MTD
4001 This option enables the building of the cfi_mtd driver
4002 in the drivers directory. The driver exports CFI flash
4005 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4006 Use buffered writes to flash.
4008 - CONFIG_FLASH_SPANSION_S29WS_N
4009 s29ws-n MirrorBit flash has non-standard addresses for buffered
4012 - CONFIG_SYS_FLASH_QUIET_TEST
4013 If this option is defined, the common CFI flash doesn't
4014 print it's warning upon not recognized FLASH banks. This
4015 is useful, if some of the configured banks are only
4016 optionally available.
4018 - CONFIG_FLASH_SHOW_PROGRESS
4019 If defined (must be an integer), print out countdown
4020 digits and dots. Recommended value: 45 (9..1) for 80
4021 column displays, 15 (3..1) for 40 column displays.
4023 - CONFIG_FLASH_VERIFY
4024 If defined, the content of the flash (destination) is compared
4025 against the source after the write operation. An error message
4026 will be printed when the contents are not identical.
4027 Please note that this option is useless in nearly all cases,
4028 since such flash programming errors usually are detected earlier
4029 while unprotecting/erasing/programming. Please only enable
4030 this option if you really know what you are doing.
4032 - CONFIG_SYS_RX_ETH_BUFFER:
4033 Defines the number of Ethernet receive buffers. On some
4034 Ethernet controllers it is recommended to set this value
4035 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4036 buffers can be full shortly after enabling the interface
4037 on high Ethernet traffic.
4038 Defaults to 4 if not defined.
4040 - CONFIG_ENV_MAX_ENTRIES
4042 Maximum number of entries in the hash table that is used
4043 internally to store the environment settings. The default
4044 setting is supposed to be generous and should work in most
4045 cases. This setting can be used to tune behaviour; see
4046 lib/hashtable.c for details.
4048 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4049 - CONFIG_ENV_FLAGS_LIST_STATIC
4050 Enable validation of the values given to environment variables when
4051 calling env set. Variables can be restricted to only decimal,
4052 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4053 the variables can also be restricted to IP address or MAC address.
4055 The format of the list is:
4056 type_attribute = [s|d|x|b|i|m]
4057 access_attribute = [a|r|o|c]
4058 attributes = type_attribute[access_attribute]
4059 entry = variable_name[:attributes]
4062 The type attributes are:
4063 s - String (default)
4066 b - Boolean ([1yYtT|0nNfF])
4070 The access attributes are:
4076 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4077 Define this to a list (string) to define the ".flags"
4078 environment variable in the default or embedded environment.
4080 - CONFIG_ENV_FLAGS_LIST_STATIC
4081 Define this to a list (string) to define validation that
4082 should be done if an entry is not found in the ".flags"
4083 environment variable. To override a setting in the static
4084 list, simply add an entry for the same variable name to the
4087 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4088 regular expression. This allows multiple variables to define the same
4089 flags without explicitly listing them for each variable.
4091 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4092 If defined, don't allow the -f switch to env set override variable
4095 - CONFIG_SYS_GENERIC_BOARD
4096 This selects the architecture-generic board system instead of the
4097 architecture-specific board files. It is intended to move boards
4098 to this new framework over time. Defining this will disable the
4099 arch/foo/lib/board.c file and use common/board_f.c and
4100 common/board_r.c instead. To use this option your architecture
4101 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4102 If you find problems enabling this option on your board please report
4103 the problem and send patches!
4105 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4106 This is set by OMAP boards for the max time that reset should
4107 be asserted. See doc/README.omap-reset-time for details on how
4108 the value can be calculated on a given board.
4111 If stdint.h is available with your toolchain you can define this
4112 option to enable it. You can provide option 'USE_STDINT=1' when
4113 building U-Boot to enable this.
4115 The following definitions that deal with the placement and management
4116 of environment data (variable area); in general, we support the
4117 following configurations:
4119 - CONFIG_BUILD_ENVCRC:
4121 Builds up envcrc with the target environment so that external utils
4122 may easily extract it and embed it in final U-Boot images.
4124 - CONFIG_ENV_IS_IN_FLASH:
4126 Define this if the environment is in flash memory.
4128 a) The environment occupies one whole flash sector, which is
4129 "embedded" in the text segment with the U-Boot code. This
4130 happens usually with "bottom boot sector" or "top boot
4131 sector" type flash chips, which have several smaller
4132 sectors at the start or the end. For instance, such a
4133 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4134 such a case you would place the environment in one of the
4135 4 kB sectors - with U-Boot code before and after it. With
4136 "top boot sector" type flash chips, you would put the
4137 environment in one of the last sectors, leaving a gap
4138 between U-Boot and the environment.
4140 - CONFIG_ENV_OFFSET:
4142 Offset of environment data (variable area) to the
4143 beginning of flash memory; for instance, with bottom boot
4144 type flash chips the second sector can be used: the offset
4145 for this sector is given here.
4147 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4151 This is just another way to specify the start address of
4152 the flash sector containing the environment (instead of
4155 - CONFIG_ENV_SECT_SIZE:
4157 Size of the sector containing the environment.
4160 b) Sometimes flash chips have few, equal sized, BIG sectors.
4161 In such a case you don't want to spend a whole sector for
4166 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4167 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4168 of this flash sector for the environment. This saves
4169 memory for the RAM copy of the environment.
4171 It may also save flash memory if you decide to use this
4172 when your environment is "embedded" within U-Boot code,
4173 since then the remainder of the flash sector could be used
4174 for U-Boot code. It should be pointed out that this is
4175 STRONGLY DISCOURAGED from a robustness point of view:
4176 updating the environment in flash makes it always
4177 necessary to erase the WHOLE sector. If something goes
4178 wrong before the contents has been restored from a copy in
4179 RAM, your target system will be dead.
4181 - CONFIG_ENV_ADDR_REDUND
4182 CONFIG_ENV_SIZE_REDUND
4184 These settings describe a second storage area used to hold
4185 a redundant copy of the environment data, so that there is
4186 a valid backup copy in case there is a power failure during
4187 a "saveenv" operation.
4189 BE CAREFUL! Any changes to the flash layout, and some changes to the
4190 source code will make it necessary to adapt <board>/u-boot.lds*
4194 - CONFIG_ENV_IS_IN_NVRAM:
4196 Define this if you have some non-volatile memory device
4197 (NVRAM, battery buffered SRAM) which you want to use for the
4203 These two #defines are used to determine the memory area you
4204 want to use for environment. It is assumed that this memory
4205 can just be read and written to, without any special
4208 BE CAREFUL! The first access to the environment happens quite early
4209 in U-Boot initialization (when we try to get the setting of for the
4210 console baudrate). You *MUST* have mapped your NVRAM area then, or
4213 Please note that even with NVRAM we still use a copy of the
4214 environment in RAM: we could work on NVRAM directly, but we want to
4215 keep settings there always unmodified except somebody uses "saveenv"
4216 to save the current settings.
4219 - CONFIG_ENV_IS_IN_EEPROM:
4221 Use this if you have an EEPROM or similar serial access
4222 device and a driver for it.
4224 - CONFIG_ENV_OFFSET:
4227 These two #defines specify the offset and size of the
4228 environment area within the total memory of your EEPROM.
4230 - CONFIG_SYS_I2C_EEPROM_ADDR:
4231 If defined, specified the chip address of the EEPROM device.
4232 The default address is zero.
4234 - CONFIG_SYS_I2C_EEPROM_BUS:
4235 If defined, specified the i2c bus of the EEPROM device.
4237 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4238 If defined, the number of bits used to address bytes in a
4239 single page in the EEPROM device. A 64 byte page, for example
4240 would require six bits.
4242 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4243 If defined, the number of milliseconds to delay between
4244 page writes. The default is zero milliseconds.
4246 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4247 The length in bytes of the EEPROM memory array address. Note
4248 that this is NOT the chip address length!
4250 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4251 EEPROM chips that implement "address overflow" are ones
4252 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4253 address and the extra bits end up in the "chip address" bit
4254 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4257 Note that we consider the length of the address field to
4258 still be one byte because the extra address bits are hidden
4259 in the chip address.
4261 - CONFIG_SYS_EEPROM_SIZE:
4262 The size in bytes of the EEPROM device.
4264 - CONFIG_ENV_EEPROM_IS_ON_I2C
4265 define this, if you have I2C and SPI activated, and your
4266 EEPROM, which holds the environment, is on the I2C bus.
4268 - CONFIG_I2C_ENV_EEPROM_BUS
4269 if you have an Environment on an EEPROM reached over
4270 I2C muxes, you can define here, how to reach this
4271 EEPROM. For example:
4273 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4275 EEPROM which holds the environment, is reached over
4276 a pca9547 i2c mux with address 0x70, channel 3.
4278 - CONFIG_ENV_IS_IN_DATAFLASH:
4280 Define this if you have a DataFlash memory device which you
4281 want to use for the environment.
4283 - CONFIG_ENV_OFFSET:
4287 These three #defines specify the offset and size of the
4288 environment area within the total memory of your DataFlash placed
4289 at the specified address.
4291 - CONFIG_ENV_IS_IN_SPI_FLASH:
4293 Define this if you have a SPI Flash memory device which you
4294 want to use for the environment.
4296 - CONFIG_ENV_OFFSET:
4299 These two #defines specify the offset and size of the
4300 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4301 aligned to an erase sector boundary.
4303 - CONFIG_ENV_SECT_SIZE:
4305 Define the SPI flash's sector size.
4307 - CONFIG_ENV_OFFSET_REDUND (optional):
4309 This setting describes a second storage area of CONFIG_ENV_SIZE
4310 size used to hold a redundant copy of the environment data, so
4311 that there is a valid backup copy in case there is a power failure
4312 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4313 aligned to an erase sector boundary.
4315 - CONFIG_ENV_SPI_BUS (optional):
4316 - CONFIG_ENV_SPI_CS (optional):
4318 Define the SPI bus and chip select. If not defined they will be 0.
4320 - CONFIG_ENV_SPI_MAX_HZ (optional):
4322 Define the SPI max work clock. If not defined then use 1MHz.
4324 - CONFIG_ENV_SPI_MODE (optional):
4326 Define the SPI work mode. If not defined then use SPI_MODE_3.
4328 - CONFIG_ENV_IS_IN_REMOTE:
4330 Define this if you have a remote memory space which you
4331 want to use for the local device's environment.
4336 These two #defines specify the address and size of the
4337 environment area within the remote memory space. The
4338 local device can get the environment from remote memory
4339 space by SRIO or PCIE links.
4341 BE CAREFUL! For some special cases, the local device can not use
4342 "saveenv" command. For example, the local device will get the
4343 environment stored in a remote NOR flash by SRIO or PCIE link,
4344 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4346 - CONFIG_ENV_IS_IN_NAND:
4348 Define this if you have a NAND device which you want to use
4349 for the environment.
4351 - CONFIG_ENV_OFFSET:
4354 These two #defines specify the offset and size of the environment
4355 area within the first NAND device. CONFIG_ENV_OFFSET must be
4356 aligned to an erase block boundary.
4358 - CONFIG_ENV_OFFSET_REDUND (optional):
4360 This setting describes a second storage area of CONFIG_ENV_SIZE
4361 size used to hold a redundant copy of the environment data, so
4362 that there is a valid backup copy in case there is a power failure
4363 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4364 aligned to an erase block boundary.
4366 - CONFIG_ENV_RANGE (optional):
4368 Specifies the length of the region in which the environment
4369 can be written. This should be a multiple of the NAND device's
4370 block size. Specifying a range with more erase blocks than
4371 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4372 the range to be avoided.
4374 - CONFIG_ENV_OFFSET_OOB (optional):
4376 Enables support for dynamically retrieving the offset of the
4377 environment from block zero's out-of-band data. The
4378 "nand env.oob" command can be used to record this offset.
4379 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4380 using CONFIG_ENV_OFFSET_OOB.
4382 - CONFIG_NAND_ENV_DST
4384 Defines address in RAM to which the nand_spl code should copy the
4385 environment. If redundant environment is used, it will be copied to
4386 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4388 - CONFIG_ENV_IS_IN_UBI:
4390 Define this if you have an UBI volume that you want to use for the
4391 environment. This has the benefit of wear-leveling the environment
4392 accesses, which is important on NAND.
4394 - CONFIG_ENV_UBI_PART:
4396 Define this to a string that is the mtd partition containing the UBI.
4398 - CONFIG_ENV_UBI_VOLUME:
4400 Define this to the name of the volume that you want to store the
4403 - CONFIG_ENV_UBI_VOLUME_REDUND:
4405 Define this to the name of another volume to store a second copy of
4406 the environment in. This will enable redundant environments in UBI.
4407 It is assumed that both volumes are in the same MTD partition.
4409 - CONFIG_UBI_SILENCE_MSG
4410 - CONFIG_UBIFS_SILENCE_MSG
4412 You will probably want to define these to avoid a really noisy system
4413 when storing the env in UBI.
4415 - CONFIG_ENV_IS_IN_FAT:
4416 Define this if you want to use the FAT file system for the environment.
4418 - FAT_ENV_INTERFACE:
4420 Define this to a string that is the name of the block device.
4422 - FAT_ENV_DEV_AND_PART:
4424 Define this to a string to specify the partition of the device. It can
4427 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4428 - "D:P": device D partition P. Error occurs if device D has no
4431 - "D" or "D:": device D partition 1 if device D has partition
4432 table, or the whole device D if has no partition
4434 - "D:auto": first partition in device D with bootable flag set.
4435 If none, first valid partition in device D. If no
4436 partition table then means device D.
4440 It's a string of the FAT file name. This file use to store the
4444 This should be defined. Otherwise it cannot save the environment file.
4446 - CONFIG_ENV_IS_IN_MMC:
4448 Define this if you have an MMC device which you want to use for the
4451 - CONFIG_SYS_MMC_ENV_DEV:
4453 Specifies which MMC device the environment is stored in.
4455 - CONFIG_SYS_MMC_ENV_PART (optional):
4457 Specifies which MMC partition the environment is stored in. If not
4458 set, defaults to partition 0, the user area. Common values might be
4459 1 (first MMC boot partition), 2 (second MMC boot partition).
4461 - CONFIG_ENV_OFFSET:
4464 These two #defines specify the offset and size of the environment
4465 area within the specified MMC device.
4467 If offset is positive (the usual case), it is treated as relative to
4468 the start of the MMC partition. If offset is negative, it is treated
4469 as relative to the end of the MMC partition. This can be useful if
4470 your board may be fitted with different MMC devices, which have
4471 different sizes for the MMC partitions, and you always want the
4472 environment placed at the very end of the partition, to leave the
4473 maximum possible space before it, to store other data.
4475 These two values are in units of bytes, but must be aligned to an
4476 MMC sector boundary.
4478 - CONFIG_ENV_OFFSET_REDUND (optional):
4480 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4481 hold a redundant copy of the environment data. This provides a
4482 valid backup copy in case the other copy is corrupted, e.g. due
4483 to a power failure during a "saveenv" operation.
4485 This value may also be positive or negative; this is handled in the
4486 same way as CONFIG_ENV_OFFSET.
4488 This value is also in units of bytes, but must also be aligned to
4489 an MMC sector boundary.
4491 - CONFIG_ENV_SIZE_REDUND (optional):
4493 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4494 set. If this value is set, it must be set to the same value as
4497 - CONFIG_SYS_SPI_INIT_OFFSET
4499 Defines offset to the initial SPI buffer area in DPRAM. The
4500 area is used at an early stage (ROM part) if the environment
4501 is configured to reside in the SPI EEPROM: We need a 520 byte
4502 scratch DPRAM area. It is used between the two initialization
4503 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4504 to be a good choice since it makes it far enough from the
4505 start of the data area as well as from the stack pointer.
4507 Please note that the environment is read-only until the monitor
4508 has been relocated to RAM and a RAM copy of the environment has been
4509 created; also, when using EEPROM you will have to use getenv_f()
4510 until then to read environment variables.
4512 The environment is protected by a CRC32 checksum. Before the monitor
4513 is relocated into RAM, as a result of a bad CRC you will be working
4514 with the compiled-in default environment - *silently*!!! [This is
4515 necessary, because the first environment variable we need is the
4516 "baudrate" setting for the console - if we have a bad CRC, we don't
4517 have any device yet where we could complain.]
4519 Note: once the monitor has been relocated, then it will complain if
4520 the default environment is used; a new CRC is computed as soon as you
4521 use the "saveenv" command to store a valid environment.
4523 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4524 Echo the inverted Ethernet link state to the fault LED.
4526 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4527 also needs to be defined.
4529 - CONFIG_SYS_FAULT_MII_ADDR:
4530 MII address of the PHY to check for the Ethernet link state.
4532 - CONFIG_NS16550_MIN_FUNCTIONS:
4533 Define this if you desire to only have use of the NS16550_init
4534 and NS16550_putc functions for the serial driver located at
4535 drivers/serial/ns16550.c. This option is useful for saving
4536 space for already greatly restricted images, including but not
4537 limited to NAND_SPL configurations.
4539 - CONFIG_DISPLAY_BOARDINFO
4540 Display information about the board that U-Boot is running on
4541 when U-Boot starts up. The board function checkboard() is called
4544 - CONFIG_DISPLAY_BOARDINFO_LATE
4545 Similar to the previous option, but display this information
4546 later, once stdio is running and output goes to the LCD, if
4549 - CONFIG_BOARD_SIZE_LIMIT:
4550 Maximum size of the U-Boot image. When defined, the
4551 build system checks that the actual size does not
4554 Low Level (hardware related) configuration options:
4555 ---------------------------------------------------
4557 - CONFIG_SYS_CACHELINE_SIZE:
4558 Cache Line Size of the CPU.
4560 - CONFIG_SYS_DEFAULT_IMMR:
4561 Default address of the IMMR after system reset.
4563 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4564 and RPXsuper) to be able to adjust the position of
4565 the IMMR register after a reset.
4567 - CONFIG_SYS_CCSRBAR_DEFAULT:
4568 Default (power-on reset) physical address of CCSR on Freescale
4571 - CONFIG_SYS_CCSRBAR:
4572 Virtual address of CCSR. On a 32-bit build, this is typically
4573 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4575 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4576 for cross-platform code that uses that macro instead.
4578 - CONFIG_SYS_CCSRBAR_PHYS:
4579 Physical address of CCSR. CCSR can be relocated to a new
4580 physical address, if desired. In this case, this macro should
4581 be set to that address. Otherwise, it should be set to the
4582 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4583 is typically relocated on 36-bit builds. It is recommended
4584 that this macro be defined via the _HIGH and _LOW macros:
4586 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4587 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4589 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4590 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4591 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4592 used in assembly code, so it must not contain typecasts or
4593 integer size suffixes (e.g. "ULL").
4595 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4596 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4597 used in assembly code, so it must not contain typecasts or
4598 integer size suffixes (e.g. "ULL").
4600 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4601 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4602 forced to a value that ensures that CCSR is not relocated.
4604 - Floppy Disk Support:
4605 CONFIG_SYS_FDC_DRIVE_NUMBER
4607 the default drive number (default value 0)
4609 CONFIG_SYS_ISA_IO_STRIDE
4611 defines the spacing between FDC chipset registers
4614 CONFIG_SYS_ISA_IO_OFFSET
4616 defines the offset of register from address. It
4617 depends on which part of the data bus is connected to
4618 the FDC chipset. (default value 0)
4620 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4621 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4624 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4625 fdc_hw_init() is called at the beginning of the FDC
4626 setup. fdc_hw_init() must be provided by the board
4627 source code. It is used to make hardware-dependent
4631 Most IDE controllers were designed to be connected with PCI
4632 interface. Only few of them were designed for AHB interface.
4633 When software is doing ATA command and data transfer to
4634 IDE devices through IDE-AHB controller, some additional
4635 registers accessing to these kind of IDE-AHB controller
4638 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4639 DO NOT CHANGE unless you know exactly what you're
4640 doing! (11-4) [MPC8xx/82xx systems only]
4642 - CONFIG_SYS_INIT_RAM_ADDR:
4644 Start address of memory area that can be used for
4645 initial data and stack; please note that this must be
4646 writable memory that is working WITHOUT special
4647 initialization, i. e. you CANNOT use normal RAM which
4648 will become available only after programming the
4649 memory controller and running certain initialization
4652 U-Boot uses the following memory types:
4653 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4654 - MPC824X: data cache
4655 - PPC4xx: data cache
4657 - CONFIG_SYS_GBL_DATA_OFFSET:
4659 Offset of the initial data structure in the memory
4660 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4661 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4662 data is located at the end of the available space
4663 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4664 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4665 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4666 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4669 On the MPC824X (or other systems that use the data
4670 cache for initial memory) the address chosen for
4671 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4672 point to an otherwise UNUSED address space between
4673 the top of RAM and the start of the PCI space.
4675 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4677 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4679 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4681 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4683 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4685 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4687 - CONFIG_SYS_OR_TIMING_SDRAM:
4690 - CONFIG_SYS_MAMR_PTA:
4691 periodic timer for refresh
4693 - CONFIG_SYS_DER: Debug Event Register (37-47)
4695 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4696 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4697 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4698 CONFIG_SYS_BR1_PRELIM:
4699 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4701 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4702 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4703 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4704 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4706 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4707 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4708 Machine Mode Register and Memory Periodic Timer
4709 Prescaler definitions (SDRAM timing)
4711 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4712 enable I2C microcode relocation patch (MPC8xx);
4713 define relocation offset in DPRAM [DSP2]
4715 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4716 enable SMC microcode relocation patch (MPC8xx);
4717 define relocation offset in DPRAM [SMC1]
4719 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4720 enable SPI microcode relocation patch (MPC8xx);
4721 define relocation offset in DPRAM [SCC4]
4723 - CONFIG_SYS_USE_OSCCLK:
4724 Use OSCM clock mode on MBX8xx board. Be careful,
4725 wrong setting might damage your board. Read
4726 doc/README.MBX before setting this variable!
4728 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4729 Offset of the bootmode word in DPRAM used by post
4730 (Power On Self Tests). This definition overrides
4731 #define'd default value in commproc.h resp.
4734 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4735 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4736 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4737 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4738 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4739 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4740 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4741 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4742 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4744 - CONFIG_PCI_DISABLE_PCIE:
4745 Disable PCI-Express on systems where it is supported but not
4748 - CONFIG_PCI_ENUM_ONLY
4749 Only scan through and get the devices on the buses.
4750 Don't do any setup work, presumably because someone or
4751 something has already done it, and we don't need to do it
4752 a second time. Useful for platforms that are pre-booted
4753 by coreboot or similar.
4755 - CONFIG_PCI_INDIRECT_BRIDGE:
4756 Enable support for indirect PCI bridges.
4759 Chip has SRIO or not
4762 Board has SRIO 1 port available
4765 Board has SRIO 2 port available
4767 - CONFIG_SRIO_PCIE_BOOT_MASTER
4768 Board can support master function for Boot from SRIO and PCIE
4770 - CONFIG_SYS_SRIOn_MEM_VIRT:
4771 Virtual Address of SRIO port 'n' memory region
4773 - CONFIG_SYS_SRIOn_MEM_PHYS:
4774 Physical Address of SRIO port 'n' memory region
4776 - CONFIG_SYS_SRIOn_MEM_SIZE:
4777 Size of SRIO port 'n' memory region
4779 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4780 Defined to tell the NAND controller that the NAND chip is using
4782 Not all NAND drivers use this symbol.
4783 Example of drivers that use it:
4784 - drivers/mtd/nand/ndfc.c
4785 - drivers/mtd/nand/mxc_nand.c
4787 - CONFIG_SYS_NDFC_EBC0_CFG
4788 Sets the EBC0_CFG register for the NDFC. If not defined
4789 a default value will be used.
4792 Get DDR timing information from an I2C EEPROM. Common
4793 with pluggable memory modules such as SODIMMs
4796 I2C address of the SPD EEPROM
4798 - CONFIG_SYS_SPD_BUS_NUM
4799 If SPD EEPROM is on an I2C bus other than the first
4800 one, specify here. Note that the value must resolve
4801 to something your driver can deal with.
4803 - CONFIG_SYS_DDR_RAW_TIMING
4804 Get DDR timing information from other than SPD. Common with
4805 soldered DDR chips onboard without SPD. DDR raw timing
4806 parameters are extracted from datasheet and hard-coded into
4807 header files or board specific files.
4809 - CONFIG_FSL_DDR_INTERACTIVE
4810 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4812 - CONFIG_FSL_DDR_SYNC_REFRESH
4813 Enable sync of refresh for multiple controllers.
4815 - CONFIG_FSL_DDR_BIST
4816 Enable built-in memory test for Freescale DDR controllers.
4818 - CONFIG_SYS_83XX_DDR_USES_CS0
4819 Only for 83xx systems. If specified, then DDR should
4820 be configured using CS0 and CS1 instead of CS2 and CS3.
4822 - CONFIG_ETHER_ON_FEC[12]
4823 Define to enable FEC[12] on a 8xx series processor.
4825 - CONFIG_FEC[12]_PHY
4826 Define to the hardcoded PHY address which corresponds
4827 to the given FEC; i. e.
4828 #define CONFIG_FEC1_PHY 4
4829 means that the PHY with address 4 is connected to FEC1
4831 When set to -1, means to probe for first available.
4833 - CONFIG_FEC[12]_PHY_NORXERR
4834 The PHY does not have a RXERR line (RMII only).
4835 (so program the FEC to ignore it).
4838 Enable RMII mode for all FECs.
4839 Note that this is a global option, we can't
4840 have one FEC in standard MII mode and another in RMII mode.
4842 - CONFIG_CRC32_VERIFY
4843 Add a verify option to the crc32 command.
4846 => crc32 -v <address> <count> <crc32>
4848 Where address/count indicate a memory area
4849 and crc32 is the correct crc32 which the
4853 Add the "loopw" memory command. This only takes effect if
4854 the memory commands are activated globally (CONFIG_CMD_MEM).
4857 Add the "mdc" and "mwc" memory commands. These are cyclic
4862 This command will print 4 bytes (10,11,12,13) each 500 ms.
4864 => mwc.l 100 12345678 10
4865 This command will write 12345678 to address 100 all 10 ms.
4867 This only takes effect if the memory commands are activated
4868 globally (CONFIG_CMD_MEM).
4870 - CONFIG_SKIP_LOWLEVEL_INIT
4871 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4872 low level initializations (like setting up the memory
4873 controller) are omitted and/or U-Boot does not
4874 relocate itself into RAM.
4876 Normally this variable MUST NOT be defined. The only
4877 exception is when U-Boot is loaded (to RAM) by some
4878 other boot loader or by a debugger which performs
4879 these initializations itself.
4882 Modifies the behaviour of start.S when compiling a loader
4883 that is executed before the actual U-Boot. E.g. when
4884 compiling a NAND SPL.
4887 Modifies the behaviour of start.S when compiling a loader
4888 that is executed after the SPL and before the actual U-Boot.
4889 It is loaded by the SPL.
4891 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4892 Only for 85xx systems. If this variable is specified, the section
4893 .resetvec is not kept and the section .bootpg is placed in the
4894 previous 4k of the .text section.
4896 - CONFIG_ARCH_MAP_SYSMEM
4897 Generally U-Boot (and in particular the md command) uses
4898 effective address. It is therefore not necessary to regard
4899 U-Boot address as virtual addresses that need to be translated
4900 to physical addresses. However, sandbox requires this, since
4901 it maintains its own little RAM buffer which contains all
4902 addressable memory. This option causes some memory accesses
4903 to be mapped through map_sysmem() / unmap_sysmem().
4905 - CONFIG_USE_ARCH_MEMCPY
4906 CONFIG_USE_ARCH_MEMSET
4907 If these options are used a optimized version of memcpy/memset will
4908 be used if available. These functions may be faster under some
4909 conditions but may increase the binary size.
4911 - CONFIG_X86_RESET_VECTOR
4912 If defined, the x86 reset vector code is included. This is not
4913 needed when U-Boot is running from Coreboot.
4916 Defines the MPU clock speed (in MHz).
4918 NOTE : currently only supported on AM335x platforms.
4920 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4921 Enables the RTC32K OSC on AM33xx based plattforms
4923 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4924 Option to disable subpage write in NAND driver
4925 driver that uses this:
4926 drivers/mtd/nand/davinci_nand.c
4928 Freescale QE/FMAN Firmware Support:
4929 -----------------------------------
4931 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4932 loading of "firmware", which is encoded in the QE firmware binary format.
4933 This firmware often needs to be loaded during U-Boot booting, so macros
4934 are used to identify the storage device (NOR flash, SPI, etc) and the address
4937 - CONFIG_SYS_FMAN_FW_ADDR
4938 The address in the storage device where the FMAN microcode is located. The
4939 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4942 - CONFIG_SYS_QE_FW_ADDR
4943 The address in the storage device where the QE microcode is located. The
4944 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4947 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4948 The maximum possible size of the firmware. The firmware binary format
4949 has a field that specifies the actual size of the firmware, but it
4950 might not be possible to read any part of the firmware unless some
4951 local storage is allocated to hold the entire firmware first.
4953 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4954 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4955 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4956 virtual address in NOR flash.
4958 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4959 Specifies that QE/FMAN firmware is located in NAND flash.
4960 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4962 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4963 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4964 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4966 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4967 Specifies that QE/FMAN firmware is located on the primary SPI
4968 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4970 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4971 Specifies that QE/FMAN firmware is located in the remote (master)
4972 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4973 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4974 window->master inbound window->master LAW->the ucode address in
4975 master's memory space.
4977 Freescale Layerscape Management Complex Firmware Support:
4978 ---------------------------------------------------------
4979 The Freescale Layerscape Management Complex (MC) supports the loading of
4981 This firmware often needs to be loaded during U-Boot booting, so macros
4982 are used to identify the storage device (NOR flash, SPI, etc) and the address
4985 - CONFIG_FSL_MC_ENET
4986 Enable the MC driver for Layerscape SoCs.
4988 - CONFIG_SYS_LS_MC_FW_ADDR
4989 The address in the storage device where the firmware is located. The
4990 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4993 - CONFIG_SYS_LS_MC_FW_LENGTH
4994 The maximum possible size of the firmware. The firmware binary format
4995 has a field that specifies the actual size of the firmware, but it
4996 might not be possible to read any part of the firmware unless some
4997 local storage is allocated to hold the entire firmware first.
4999 - CONFIG_SYS_LS_MC_FW_IN_NOR
5000 Specifies that MC firmware is located in NOR flash, mapped as
5001 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5002 virtual address in NOR flash.
5004 Freescale Layerscape Debug Server Support:
5005 -------------------------------------------
5006 The Freescale Layerscape Debug Server Support supports the loading of
5007 "Debug Server firmware" and triggering SP boot-rom.
5008 This firmware often needs to be loaded during U-Boot booting.
5010 - CONFIG_FSL_DEBUG_SERVER
5011 Enable the Debug Server for Layerscape SoCs.
5013 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5014 Define minimum DDR size required for debug server image
5016 - CONFIG_SYS_MC_RSV_MEM_ALIGN
5017 Define alignment of reserved memory MC requires
5022 In order to achieve reproducible builds, timestamps used in the U-Boot build
5023 process have to be set to a fixed value.
5025 This is done using the SOURCE_DATE_EPOCH environment variable.
5026 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5027 option for U-Boot or an environment variable in U-Boot.
5029 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5031 Building the Software:
5032 ======================
5034 Building U-Boot has been tested in several native build environments
5035 and in many different cross environments. Of course we cannot support
5036 all possibly existing versions of cross development tools in all
5037 (potentially obsolete) versions. In case of tool chain problems we
5038 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5039 which is extensively used to build and test U-Boot.
5041 If you are not using a native environment, it is assumed that you
5042 have GNU cross compiling tools available in your path. In this case,
5043 you must set the environment variable CROSS_COMPILE in your shell.
5044 Note that no changes to the Makefile or any other source files are
5045 necessary. For example using the ELDK on a 4xx CPU, please enter:
5047 $ CROSS_COMPILE=ppc_4xx-
5048 $ export CROSS_COMPILE
5050 Note: If you wish to generate Windows versions of the utilities in
5051 the tools directory you can use the MinGW toolchain
5052 (http://www.mingw.org). Set your HOST tools to the MinGW
5053 toolchain and execute 'make tools'. For example:
5055 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5057 Binaries such as tools/mkimage.exe will be created which can
5058 be executed on computers running Windows.
5060 U-Boot is intended to be simple to build. After installing the
5061 sources you must configure U-Boot for one specific board type. This
5066 where "NAME_defconfig" is the name of one of the existing configu-
5067 rations; see boards.cfg for supported names.
5069 Note: for some board special configuration names may exist; check if
5070 additional information is available from the board vendor; for
5071 instance, the TQM823L systems are available without (standard)
5072 or with LCD support. You can select such additional "features"
5073 when choosing the configuration, i. e.
5075 make TQM823L_defconfig
5076 - will configure for a plain TQM823L, i. e. no LCD support
5078 make TQM823L_LCD_defconfig
5079 - will configure for a TQM823L with U-Boot console on LCD
5084 Finally, type "make all", and you should get some working U-Boot
5085 images ready for download to / installation on your system:
5087 - "u-boot.bin" is a raw binary image
5088 - "u-boot" is an image in ELF binary format
5089 - "u-boot.srec" is in Motorola S-Record format
5091 By default the build is performed locally and the objects are saved
5092 in the source directory. One of the two methods can be used to change
5093 this behavior and build U-Boot to some external directory:
5095 1. Add O= to the make command line invocations:
5097 make O=/tmp/build distclean
5098 make O=/tmp/build NAME_defconfig
5099 make O=/tmp/build all
5101 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5103 export KBUILD_OUTPUT=/tmp/build
5108 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5112 Please be aware that the Makefiles assume you are using GNU make, so
5113 for instance on NetBSD you might need to use "gmake" instead of
5117 If the system board that you have is not listed, then you will need
5118 to port U-Boot to your hardware platform. To do this, follow these
5121 1. Add a new configuration option for your board to the toplevel
5122 "boards.cfg" file, using the existing entries as examples.
5123 Follow the instructions there to keep the boards in order.
5124 2. Create a new directory to hold your board specific code. Add any
5125 files you need. In your board directory, you will need at least
5126 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5127 3. Create a new configuration file "include/configs/<board>.h" for
5129 3. If you're porting U-Boot to a new CPU, then also create a new
5130 directory to hold your CPU specific code. Add any files you need.
5131 4. Run "make <board>_defconfig" with your new name.
5132 5. Type "make", and you should get a working "u-boot.srec" file
5133 to be installed on your target system.
5134 6. Debug and solve any problems that might arise.
5135 [Of course, this last step is much harder than it sounds.]
5138 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5139 ==============================================================
5141 If you have modified U-Boot sources (for instance added a new board
5142 or support for new devices, a new CPU, etc.) you are expected to
5143 provide feedback to the other developers. The feedback normally takes
5144 the form of a "patch", i. e. a context diff against a certain (latest
5145 official or latest in the git repository) version of U-Boot sources.
5147 But before you submit such a patch, please verify that your modifi-
5148 cation did not break existing code. At least make sure that *ALL* of
5149 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5150 just run the "MAKEALL" script, which will configure and build U-Boot
5151 for ALL supported system. Be warned, this will take a while. You can
5152 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5153 environment variable to the script, i. e. to use the ELDK cross tools
5156 CROSS_COMPILE=ppc_8xx- MAKEALL
5158 or to build on a native PowerPC system you can type
5160 CROSS_COMPILE=' ' MAKEALL
5162 When using the MAKEALL script, the default behaviour is to build
5163 U-Boot in the source directory. This location can be changed by
5164 setting the BUILD_DIR environment variable. Also, for each target
5165 built, the MAKEALL script saves two log files (<target>.ERR and
5166 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5167 location can be changed by setting the MAKEALL_LOGDIR environment
5168 variable. For example:
5170 export BUILD_DIR=/tmp/build
5171 export MAKEALL_LOGDIR=/tmp/log
5172 CROSS_COMPILE=ppc_8xx- MAKEALL
5174 With the above settings build objects are saved in the /tmp/build,
5175 log files are saved in the /tmp/log and the source tree remains clean
5176 during the whole build process.
5179 See also "U-Boot Porting Guide" below.
5182 Monitor Commands - Overview:
5183 ============================
5185 go - start application at address 'addr'
5186 run - run commands in an environment variable
5187 bootm - boot application image from memory
5188 bootp - boot image via network using BootP/TFTP protocol
5189 bootz - boot zImage from memory
5190 tftpboot- boot image via network using TFTP protocol
5191 and env variables "ipaddr" and "serverip"
5192 (and eventually "gatewayip")
5193 tftpput - upload a file via network using TFTP protocol
5194 rarpboot- boot image via network using RARP/TFTP protocol
5195 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5196 loads - load S-Record file over serial line
5197 loadb - load binary file over serial line (kermit mode)
5199 mm - memory modify (auto-incrementing)
5200 nm - memory modify (constant address)
5201 mw - memory write (fill)
5203 cmp - memory compare
5204 crc32 - checksum calculation
5205 i2c - I2C sub-system
5206 sspi - SPI utility commands
5207 base - print or set address offset
5208 printenv- print environment variables
5209 setenv - set environment variables
5210 saveenv - save environment variables to persistent storage
5211 protect - enable or disable FLASH write protection
5212 erase - erase FLASH memory
5213 flinfo - print FLASH memory information
5214 nand - NAND memory operations (see doc/README.nand)
5215 bdinfo - print Board Info structure
5216 iminfo - print header information for application image
5217 coninfo - print console devices and informations
5218 ide - IDE sub-system
5219 loop - infinite loop on address range
5220 loopw - infinite write loop on address range
5221 mtest - simple RAM test
5222 icache - enable or disable instruction cache
5223 dcache - enable or disable data cache
5224 reset - Perform RESET of the CPU
5225 echo - echo args to console
5226 version - print monitor version
5227 help - print online help
5228 ? - alias for 'help'
5231 Monitor Commands - Detailed Description:
5232 ========================================
5236 For now: just type "help <command>".
5239 Environment Variables:
5240 ======================
5242 U-Boot supports user configuration using Environment Variables which
5243 can be made persistent by saving to Flash memory.
5245 Environment Variables are set using "setenv", printed using
5246 "printenv", and saved to Flash using "saveenv". Using "setenv"
5247 without a value can be used to delete a variable from the
5248 environment. As long as you don't save the environment you are
5249 working with an in-memory copy. In case the Flash area containing the
5250 environment is erased by accident, a default environment is provided.
5252 Some configuration options can be set using Environment Variables.
5254 List of environment variables (most likely not complete):
5256 baudrate - see CONFIG_BAUDRATE
5258 bootdelay - see CONFIG_BOOTDELAY
5260 bootcmd - see CONFIG_BOOTCOMMAND
5262 bootargs - Boot arguments when booting an RTOS image
5264 bootfile - Name of the image to load with TFTP
5266 bootm_low - Memory range available for image processing in the bootm
5267 command can be restricted. This variable is given as
5268 a hexadecimal number and defines lowest address allowed
5269 for use by the bootm command. See also "bootm_size"
5270 environment variable. Address defined by "bootm_low" is
5271 also the base of the initial memory mapping for the Linux
5272 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5275 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5276 This variable is given as a hexadecimal number and it
5277 defines the size of the memory region starting at base
5278 address bootm_low that is accessible by the Linux kernel
5279 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5280 as the default value if it is defined, and bootm_size is
5283 bootm_size - Memory range available for image processing in the bootm
5284 command can be restricted. This variable is given as
5285 a hexadecimal number and defines the size of the region
5286 allowed for use by the bootm command. See also "bootm_low"
5287 environment variable.
5289 updatefile - Location of the software update file on a TFTP server, used
5290 by the automatic software update feature. Please refer to
5291 documentation in doc/README.update for more details.
5293 autoload - if set to "no" (any string beginning with 'n'),
5294 "bootp" will just load perform a lookup of the
5295 configuration from the BOOTP server, but not try to
5296 load any image using TFTP
5298 autostart - if set to "yes", an image loaded using the "bootp",
5299 "rarpboot", "tftpboot" or "diskboot" commands will
5300 be automatically started (by internally calling
5303 If set to "no", a standalone image passed to the
5304 "bootm" command will be copied to the load address
5305 (and eventually uncompressed), but NOT be started.
5306 This can be used to load and uncompress arbitrary
5309 fdt_high - if set this restricts the maximum address that the
5310 flattened device tree will be copied into upon boot.
5311 For example, if you have a system with 1 GB memory
5312 at physical address 0x10000000, while Linux kernel
5313 only recognizes the first 704 MB as low memory, you
5314 may need to set fdt_high as 0x3C000000 to have the
5315 device tree blob be copied to the maximum address
5316 of the 704 MB low memory, so that Linux kernel can
5317 access it during the boot procedure.
5319 If this is set to the special value 0xFFFFFFFF then
5320 the fdt will not be copied at all on boot. For this
5321 to work it must reside in writable memory, have
5322 sufficient padding on the end of it for u-boot to
5323 add the information it needs into it, and the memory
5324 must be accessible by the kernel.
5326 fdtcontroladdr- if set this is the address of the control flattened
5327 device tree used by U-Boot when CONFIG_OF_CONTROL is
5330 i2cfast - (PPC405GP|PPC405EP only)
5331 if set to 'y' configures Linux I2C driver for fast
5332 mode (400kHZ). This environment variable is used in
5333 initialization code. So, for changes to be effective
5334 it must be saved and board must be reset.
5336 initrd_high - restrict positioning of initrd images:
5337 If this variable is not set, initrd images will be
5338 copied to the highest possible address in RAM; this
5339 is usually what you want since it allows for
5340 maximum initrd size. If for some reason you want to
5341 make sure that the initrd image is loaded below the
5342 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5343 variable to a value of "no" or "off" or "0".
5344 Alternatively, you can set it to a maximum upper
5345 address to use (U-Boot will still check that it
5346 does not overwrite the U-Boot stack and data).
5348 For instance, when you have a system with 16 MB
5349 RAM, and want to reserve 4 MB from use by Linux,
5350 you can do this by adding "mem=12M" to the value of
5351 the "bootargs" variable. However, now you must make
5352 sure that the initrd image is placed in the first
5353 12 MB as well - this can be done with
5355 setenv initrd_high 00c00000
5357 If you set initrd_high to 0xFFFFFFFF, this is an
5358 indication to U-Boot that all addresses are legal
5359 for the Linux kernel, including addresses in flash
5360 memory. In this case U-Boot will NOT COPY the
5361 ramdisk at all. This may be useful to reduce the
5362 boot time on your system, but requires that this
5363 feature is supported by your Linux kernel.
5365 ipaddr - IP address; needed for tftpboot command
5367 loadaddr - Default load address for commands like "bootp",
5368 "rarpboot", "tftpboot", "loadb" or "diskboot"
5370 loads_echo - see CONFIG_LOADS_ECHO
5372 serverip - TFTP server IP address; needed for tftpboot command
5374 bootretry - see CONFIG_BOOT_RETRY_TIME
5376 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5378 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5380 ethprime - controls which interface is used first.
5382 ethact - controls which interface is currently active.
5383 For example you can do the following
5385 => setenv ethact FEC
5386 => ping 192.168.0.1 # traffic sent on FEC
5387 => setenv ethact SCC
5388 => ping 10.0.0.1 # traffic sent on SCC
5390 ethrotate - When set to "no" U-Boot does not go through all
5391 available network interfaces.
5392 It just stays at the currently selected interface.
5394 netretry - When set to "no" each network operation will
5395 either succeed or fail without retrying.
5396 When set to "once" the network operation will
5397 fail when all the available network interfaces
5398 are tried once without success.
5399 Useful on scripts which control the retry operation
5402 npe_ucode - set load address for the NPE microcode
5404 silent_linux - If set then Linux will be told to boot silently, by
5405 changing the console to be empty. If "yes" it will be
5406 made silent. If "no" it will not be made silent. If
5407 unset, then it will be made silent if the U-Boot console
5410 tftpsrcp - If this is set, the value is used for TFTP's
5413 tftpdstp - If this is set, the value is used for TFTP's UDP
5414 destination port instead of the Well Know Port 69.
5416 tftpblocksize - Block size to use for TFTP transfers; if not set,
5417 we use the TFTP server's default block size
5419 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5420 seconds, minimum value is 1000 = 1 second). Defines
5421 when a packet is considered to be lost so it has to
5422 be retransmitted. The default is 5000 = 5 seconds.
5423 Lowering this value may make downloads succeed
5424 faster in networks with high packet loss rates or
5425 with unreliable TFTP servers.
5427 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5428 unit, minimum value = 0). Defines how many timeouts
5429 can happen during a single file transfer before that
5430 transfer is aborted. The default is 10, and 0 means
5431 'no timeouts allowed'. Increasing this value may help
5432 downloads succeed with high packet loss rates, or with
5433 unreliable TFTP servers or client hardware.
5435 vlan - When set to a value < 4095 the traffic over
5436 Ethernet is encapsulated/received over 802.1q
5439 The following image location variables contain the location of images
5440 used in booting. The "Image" column gives the role of the image and is
5441 not an environment variable name. The other columns are environment
5442 variable names. "File Name" gives the name of the file on a TFTP
5443 server, "RAM Address" gives the location in RAM the image will be
5444 loaded to, and "Flash Location" gives the image's address in NOR
5445 flash or offset in NAND flash.
5447 *Note* - these variables don't have to be defined for all boards, some
5448 boards currently use other variables for these purposes, and some
5449 boards use these variables for other purposes.
5451 Image File Name RAM Address Flash Location
5452 ----- --------- ----------- --------------
5453 u-boot u-boot u-boot_addr_r u-boot_addr
5454 Linux kernel bootfile kernel_addr_r kernel_addr
5455 device tree blob fdtfile fdt_addr_r fdt_addr
5456 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5458 The following environment variables may be used and automatically
5459 updated by the network boot commands ("bootp" and "rarpboot"),
5460 depending the information provided by your boot server:
5462 bootfile - see above
5463 dnsip - IP address of your Domain Name Server
5464 dnsip2 - IP address of your secondary Domain Name Server
5465 gatewayip - IP address of the Gateway (Router) to use
5466 hostname - Target hostname
5468 netmask - Subnet Mask
5469 rootpath - Pathname of the root filesystem on the NFS server
5470 serverip - see above
5473 There are two special Environment Variables:
5475 serial# - contains hardware identification information such
5476 as type string and/or serial number
5477 ethaddr - Ethernet address
5479 These variables can be set only once (usually during manufacturing of
5480 the board). U-Boot refuses to delete or overwrite these variables
5481 once they have been set once.
5484 Further special Environment Variables:
5486 ver - Contains the U-Boot version string as printed
5487 with the "version" command. This variable is
5488 readonly (see CONFIG_VERSION_VARIABLE).
5491 Please note that changes to some configuration parameters may take
5492 only effect after the next boot (yes, that's just like Windoze :-).
5495 Callback functions for environment variables:
5496 ---------------------------------------------
5498 For some environment variables, the behavior of u-boot needs to change
5499 when their values are changed. This functionality allows functions to
5500 be associated with arbitrary variables. On creation, overwrite, or
5501 deletion, the callback will provide the opportunity for some side
5502 effect to happen or for the change to be rejected.
5504 The callbacks are named and associated with a function using the
5505 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5507 These callbacks are associated with variables in one of two ways. The
5508 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5509 in the board configuration to a string that defines a list of
5510 associations. The list must be in the following format:
5512 entry = variable_name[:callback_name]
5515 If the callback name is not specified, then the callback is deleted.
5516 Spaces are also allowed anywhere in the list.
5518 Callbacks can also be associated by defining the ".callbacks" variable
5519 with the same list format above. Any association in ".callbacks" will
5520 override any association in the static list. You can define
5521 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5522 ".callbacks" environment variable in the default or embedded environment.
5524 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5525 regular expression. This allows multiple variables to be connected to
5526 the same callback without explicitly listing them all out.
5529 Command Line Parsing:
5530 =====================
5532 There are two different command line parsers available with U-Boot:
5533 the old "simple" one, and the much more powerful "hush" shell:
5535 Old, simple command line parser:
5536 --------------------------------
5538 - supports environment variables (through setenv / saveenv commands)
5539 - several commands on one line, separated by ';'
5540 - variable substitution using "... ${name} ..." syntax
5541 - special characters ('$', ';') can be escaped by prefixing with '\',
5543 setenv bootcmd bootm \${address}
5544 - You can also escape text by enclosing in single apostrophes, for example:
5545 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5550 - similar to Bourne shell, with control structures like
5551 if...then...else...fi, for...do...done; while...do...done,
5552 until...do...done, ...
5553 - supports environment ("global") variables (through setenv / saveenv
5554 commands) and local shell variables (through standard shell syntax
5555 "name=value"); only environment variables can be used with "run"
5561 (1) If a command line (or an environment variable executed by a "run"
5562 command) contains several commands separated by semicolon, and
5563 one of these commands fails, then the remaining commands will be
5566 (2) If you execute several variables with one call to run (i. e.
5567 calling run with a list of variables as arguments), any failing
5568 command will cause "run" to terminate, i. e. the remaining
5569 variables are not executed.
5571 Note for Redundant Ethernet Interfaces:
5572 =======================================
5574 Some boards come with redundant Ethernet interfaces; U-Boot supports
5575 such configurations and is capable of automatic selection of a
5576 "working" interface when needed. MAC assignment works as follows:
5578 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5579 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5580 "eth1addr" (=>eth1), "eth2addr", ...
5582 If the network interface stores some valid MAC address (for instance
5583 in SROM), this is used as default address if there is NO correspon-
5584 ding setting in the environment; if the corresponding environment
5585 variable is set, this overrides the settings in the card; that means:
5587 o If the SROM has a valid MAC address, and there is no address in the
5588 environment, the SROM's address is used.
5590 o If there is no valid address in the SROM, and a definition in the
5591 environment exists, then the value from the environment variable is
5594 o If both the SROM and the environment contain a MAC address, and
5595 both addresses are the same, this MAC address is used.
5597 o If both the SROM and the environment contain a MAC address, and the
5598 addresses differ, the value from the environment is used and a
5601 o If neither SROM nor the environment contain a MAC address, an error
5602 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5603 a random, locally-assigned MAC is used.
5605 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5606 will be programmed into hardware as part of the initialization process. This
5607 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5608 The naming convention is as follows:
5609 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5614 U-Boot is capable of booting (and performing other auxiliary operations on)
5615 images in two formats:
5617 New uImage format (FIT)
5618 -----------------------
5620 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5621 to Flattened Device Tree). It allows the use of images with multiple
5622 components (several kernels, ramdisks, etc.), with contents protected by
5623 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5629 Old image format is based on binary files which can be basically anything,
5630 preceded by a special header; see the definitions in include/image.h for
5631 details; basically, the header defines the following image properties:
5633 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5634 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5635 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5636 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5638 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5639 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5640 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5641 * Compression Type (uncompressed, gzip, bzip2)
5647 The header is marked by a special Magic Number, and both the header
5648 and the data portions of the image are secured against corruption by
5655 Although U-Boot should support any OS or standalone application
5656 easily, the main focus has always been on Linux during the design of
5659 U-Boot includes many features that so far have been part of some
5660 special "boot loader" code within the Linux kernel. Also, any
5661 "initrd" images to be used are no longer part of one big Linux image;
5662 instead, kernel and "initrd" are separate images. This implementation
5663 serves several purposes:
5665 - the same features can be used for other OS or standalone
5666 applications (for instance: using compressed images to reduce the
5667 Flash memory footprint)
5669 - it becomes much easier to port new Linux kernel versions because
5670 lots of low-level, hardware dependent stuff are done by U-Boot
5672 - the same Linux kernel image can now be used with different "initrd"
5673 images; of course this also means that different kernel images can
5674 be run with the same "initrd". This makes testing easier (you don't
5675 have to build a new "zImage.initrd" Linux image when you just
5676 change a file in your "initrd"). Also, a field-upgrade of the
5677 software is easier now.
5683 Porting Linux to U-Boot based systems:
5684 ---------------------------------------
5686 U-Boot cannot save you from doing all the necessary modifications to
5687 configure the Linux device drivers for use with your target hardware
5688 (no, we don't intend to provide a full virtual machine interface to
5691 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5693 Just make sure your machine specific header file (for instance
5694 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5695 Information structure as we define in include/asm-<arch>/u-boot.h,
5696 and make sure that your definition of IMAP_ADDR uses the same value
5697 as your U-Boot configuration in CONFIG_SYS_IMMR.
5699 Note that U-Boot now has a driver model, a unified model for drivers.
5700 If you are adding a new driver, plumb it into driver model. If there
5701 is no uclass available, you are encouraged to create one. See
5705 Configuring the Linux kernel:
5706 -----------------------------
5708 No specific requirements for U-Boot. Make sure you have some root
5709 device (initial ramdisk, NFS) for your target system.
5712 Building a Linux Image:
5713 -----------------------
5715 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5716 not used. If you use recent kernel source, a new build target
5717 "uImage" will exist which automatically builds an image usable by
5718 U-Boot. Most older kernels also have support for a "pImage" target,
5719 which was introduced for our predecessor project PPCBoot and uses a
5720 100% compatible format.
5724 make TQM850L_defconfig
5729 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5730 encapsulate a compressed Linux kernel image with header information,
5731 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5733 * build a standard "vmlinux" kernel image (in ELF binary format):
5735 * convert the kernel into a raw binary image:
5737 ${CROSS_COMPILE}-objcopy -O binary \
5738 -R .note -R .comment \
5739 -S vmlinux linux.bin
5741 * compress the binary image:
5745 * package compressed binary image for U-Boot:
5747 mkimage -A ppc -O linux -T kernel -C gzip \
5748 -a 0 -e 0 -n "Linux Kernel Image" \
5749 -d linux.bin.gz uImage
5752 The "mkimage" tool can also be used to create ramdisk images for use
5753 with U-Boot, either separated from the Linux kernel image, or
5754 combined into one file. "mkimage" encapsulates the images with a 64
5755 byte header containing information about target architecture,
5756 operating system, image type, compression method, entry points, time
5757 stamp, CRC32 checksums, etc.
5759 "mkimage" can be called in two ways: to verify existing images and
5760 print the header information, or to build new images.
5762 In the first form (with "-l" option) mkimage lists the information
5763 contained in the header of an existing U-Boot image; this includes
5764 checksum verification:
5766 tools/mkimage -l image
5767 -l ==> list image header information
5769 The second form (with "-d" option) is used to build a U-Boot image
5770 from a "data file" which is used as image payload:
5772 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5773 -n name -d data_file image
5774 -A ==> set architecture to 'arch'
5775 -O ==> set operating system to 'os'
5776 -T ==> set image type to 'type'
5777 -C ==> set compression type 'comp'
5778 -a ==> set load address to 'addr' (hex)
5779 -e ==> set entry point to 'ep' (hex)
5780 -n ==> set image name to 'name'
5781 -d ==> use image data from 'datafile'
5783 Right now, all Linux kernels for PowerPC systems use the same load
5784 address (0x00000000), but the entry point address depends on the
5787 - 2.2.x kernels have the entry point at 0x0000000C,
5788 - 2.3.x and later kernels have the entry point at 0x00000000.
5790 So a typical call to build a U-Boot image would read:
5792 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5793 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5794 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5795 > examples/uImage.TQM850L
5796 Image Name: 2.4.4 kernel for TQM850L
5797 Created: Wed Jul 19 02:34:59 2000
5798 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5799 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5800 Load Address: 0x00000000
5801 Entry Point: 0x00000000
5803 To verify the contents of the image (or check for corruption):
5805 -> tools/mkimage -l examples/uImage.TQM850L
5806 Image Name: 2.4.4 kernel for TQM850L
5807 Created: Wed Jul 19 02:34:59 2000
5808 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5809 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5810 Load Address: 0x00000000
5811 Entry Point: 0x00000000
5813 NOTE: for embedded systems where boot time is critical you can trade
5814 speed for memory and install an UNCOMPRESSED image instead: this
5815 needs more space in Flash, but boots much faster since it does not
5816 need to be uncompressed:
5818 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5819 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5820 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5821 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5822 > examples/uImage.TQM850L-uncompressed
5823 Image Name: 2.4.4 kernel for TQM850L
5824 Created: Wed Jul 19 02:34:59 2000
5825 Image Type: PowerPC Linux Kernel Image (uncompressed)
5826 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5827 Load Address: 0x00000000
5828 Entry Point: 0x00000000
5831 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5832 when your kernel is intended to use an initial ramdisk:
5834 -> tools/mkimage -n 'Simple Ramdisk Image' \
5835 > -A ppc -O linux -T ramdisk -C gzip \
5836 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5837 Image Name: Simple Ramdisk Image
5838 Created: Wed Jan 12 14:01:50 2000
5839 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5840 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5841 Load Address: 0x00000000
5842 Entry Point: 0x00000000
5844 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5845 option performs the converse operation of the mkimage's second form (the "-d"
5846 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5849 tools/dumpimage -i image -T type -p position data_file
5850 -i ==> extract from the 'image' a specific 'data_file'
5851 -T ==> set image type to 'type'
5852 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5855 Installing a Linux Image:
5856 -------------------------
5858 To downloading a U-Boot image over the serial (console) interface,
5859 you must convert the image to S-Record format:
5861 objcopy -I binary -O srec examples/image examples/image.srec
5863 The 'objcopy' does not understand the information in the U-Boot
5864 image header, so the resulting S-Record file will be relative to
5865 address 0x00000000. To load it to a given address, you need to
5866 specify the target address as 'offset' parameter with the 'loads'
5869 Example: install the image to address 0x40100000 (which on the
5870 TQM8xxL is in the first Flash bank):
5872 => erase 40100000 401FFFFF
5878 ## Ready for S-Record download ...
5879 ~>examples/image.srec
5880 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5882 15989 15990 15991 15992
5883 [file transfer complete]
5885 ## Start Addr = 0x00000000
5888 You can check the success of the download using the 'iminfo' command;
5889 this includes a checksum verification so you can be sure no data
5890 corruption happened:
5894 ## Checking Image 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
5906 The "bootm" command is used to boot an application that is stored in
5907 memory (RAM or Flash). In case of a Linux kernel image, the contents
5908 of the "bootargs" environment variable is passed to the kernel as
5909 parameters. You can check and modify this variable using the
5910 "printenv" and "setenv" commands:
5913 => printenv bootargs
5914 bootargs=root=/dev/ram
5916 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5918 => printenv bootargs
5919 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5922 ## Booting Linux kernel at 40020000 ...
5923 Image Name: 2.2.13 for NFS on TQM850L
5924 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5925 Data Size: 381681 Bytes = 372 kB = 0 MB
5926 Load Address: 00000000
5927 Entry Point: 0000000c
5928 Verifying Checksum ... OK
5929 Uncompressing Kernel Image ... OK
5930 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
5931 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5932 time_init: decrementer frequency = 187500000/60
5933 Calibrating delay loop... 49.77 BogoMIPS
5934 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5937 If you want to boot a Linux kernel with initial RAM disk, you pass
5938 the memory addresses of both the kernel and the initrd image (PPBCOOT
5939 format!) to the "bootm" command:
5941 => imi 40100000 40200000
5943 ## Checking Image at 40100000 ...
5944 Image Name: 2.2.13 for initrd on TQM850L
5945 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5946 Data Size: 335725 Bytes = 327 kB = 0 MB
5947 Load Address: 00000000
5948 Entry Point: 0000000c
5949 Verifying Checksum ... OK
5951 ## Checking Image at 40200000 ...
5952 Image Name: Simple Ramdisk Image
5953 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5954 Data Size: 566530 Bytes = 553 kB = 0 MB
5955 Load Address: 00000000
5956 Entry Point: 00000000
5957 Verifying Checksum ... OK
5959 => bootm 40100000 40200000
5960 ## Booting Linux kernel at 40100000 ...
5961 Image Name: 2.2.13 for initrd on TQM850L
5962 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5963 Data Size: 335725 Bytes = 327 kB = 0 MB
5964 Load Address: 00000000
5965 Entry Point: 0000000c
5966 Verifying Checksum ... OK
5967 Uncompressing Kernel Image ... OK
5968 ## Loading RAMDisk Image at 40200000 ...
5969 Image Name: Simple Ramdisk Image
5970 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5971 Data Size: 566530 Bytes = 553 kB = 0 MB
5972 Load Address: 00000000
5973 Entry Point: 00000000
5974 Verifying Checksum ... OK
5975 Loading Ramdisk ... OK
5976 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
5977 Boot arguments: root=/dev/ram
5978 time_init: decrementer frequency = 187500000/60
5979 Calibrating delay loop... 49.77 BogoMIPS
5981 RAMDISK: Compressed image found at block 0
5982 VFS: Mounted root (ext2 filesystem).
5986 Boot Linux and pass a flat device tree:
5989 First, U-Boot must be compiled with the appropriate defines. See the section
5990 titled "Linux Kernel Interface" above for a more in depth explanation. The
5991 following is an example of how to start a kernel and pass an updated
5997 oft=oftrees/mpc8540ads.dtb
5998 => tftp $oftaddr $oft
5999 Speed: 1000, full duplex
6001 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6002 Filename 'oftrees/mpc8540ads.dtb'.
6003 Load address: 0x300000
6006 Bytes transferred = 4106 (100a hex)
6007 => tftp $loadaddr $bootfile
6008 Speed: 1000, full duplex
6010 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6012 Load address: 0x200000
6013 Loading:############
6015 Bytes transferred = 1029407 (fb51f hex)
6020 => bootm $loadaddr - $oftaddr
6021 ## Booting image at 00200000 ...
6022 Image Name: Linux-2.6.17-dirty
6023 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6024 Data Size: 1029343 Bytes = 1005.2 kB
6025 Load Address: 00000000
6026 Entry Point: 00000000
6027 Verifying Checksum ... OK
6028 Uncompressing Kernel Image ... OK
6029 Booting using flat device tree at 0x300000
6030 Using MPC85xx ADS machine description
6031 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6035 More About U-Boot Image Types:
6036 ------------------------------
6038 U-Boot supports the following image types:
6040 "Standalone Programs" are directly runnable in the environment
6041 provided by U-Boot; it is expected that (if they behave
6042 well) you can continue to work in U-Boot after return from
6043 the Standalone Program.
6044 "OS Kernel Images" are usually images of some Embedded OS which
6045 will take over control completely. Usually these programs
6046 will install their own set of exception handlers, device
6047 drivers, set up the MMU, etc. - this means, that you cannot
6048 expect to re-enter U-Boot except by resetting the CPU.
6049 "RAMDisk Images" are more or less just data blocks, and their
6050 parameters (address, size) are passed to an OS kernel that is
6052 "Multi-File Images" contain several images, typically an OS
6053 (Linux) kernel image and one or more data images like
6054 RAMDisks. This construct is useful for instance when you want
6055 to boot over the network using BOOTP etc., where the boot
6056 server provides just a single image file, but you want to get
6057 for instance an OS kernel and a RAMDisk image.
6059 "Multi-File Images" start with a list of image sizes, each
6060 image size (in bytes) specified by an "uint32_t" in network
6061 byte order. This list is terminated by an "(uint32_t)0".
6062 Immediately after the terminating 0 follow the images, one by
6063 one, all aligned on "uint32_t" boundaries (size rounded up to
6064 a multiple of 4 bytes).
6066 "Firmware Images" are binary images containing firmware (like
6067 U-Boot or FPGA images) which usually will be programmed to
6070 "Script files" are command sequences that will be executed by
6071 U-Boot's command interpreter; this feature is especially
6072 useful when you configure U-Boot to use a real shell (hush)
6073 as command interpreter.
6075 Booting the Linux zImage:
6076 -------------------------
6078 On some platforms, it's possible to boot Linux zImage. This is done
6079 using the "bootz" command. The syntax of "bootz" command is the same
6080 as the syntax of "bootm" command.
6082 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6083 kernel with raw initrd images. The syntax is slightly different, the
6084 address of the initrd must be augmented by it's size, in the following
6085 format: "<initrd addres>:<initrd size>".
6091 One of the features of U-Boot is that you can dynamically load and
6092 run "standalone" applications, which can use some resources of
6093 U-Boot like console I/O functions or interrupt services.
6095 Two simple examples are included with the sources:
6100 'examples/hello_world.c' contains a small "Hello World" Demo
6101 application; it is automatically compiled when you build U-Boot.
6102 It's configured to run at address 0x00040004, so you can play with it
6106 ## Ready for S-Record download ...
6107 ~>examples/hello_world.srec
6108 1 2 3 4 5 6 7 8 9 10 11 ...
6109 [file transfer complete]
6111 ## Start Addr = 0x00040004
6113 => go 40004 Hello World! This is a test.
6114 ## Starting application at 0x00040004 ...
6125 Hit any key to exit ...
6127 ## Application terminated, rc = 0x0
6129 Another example, which demonstrates how to register a CPM interrupt
6130 handler with the U-Boot code, can be found in 'examples/timer.c'.
6131 Here, a CPM timer is set up to generate an interrupt every second.
6132 The interrupt service routine is trivial, just printing a '.'
6133 character, but this is just a demo program. The application can be
6134 controlled by the following keys:
6136 ? - print current values og the CPM Timer registers
6137 b - enable interrupts and start timer
6138 e - stop timer and disable interrupts
6139 q - quit application
6142 ## Ready for S-Record download ...
6143 ~>examples/timer.srec
6144 1 2 3 4 5 6 7 8 9 10 11 ...
6145 [file transfer complete]
6147 ## Start Addr = 0x00040004
6150 ## Starting application at 0x00040004 ...
6153 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6156 [q, b, e, ?] Set interval 1000000 us
6159 [q, b, e, ?] ........
6160 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6163 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6166 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6169 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6171 [q, b, e, ?] ...Stopping timer
6173 [q, b, e, ?] ## Application terminated, rc = 0x0
6179 Over time, many people have reported problems when trying to use the
6180 "minicom" terminal emulation program for serial download. I (wd)
6181 consider minicom to be broken, and recommend not to use it. Under
6182 Unix, I recommend to use C-Kermit for general purpose use (and
6183 especially for kermit binary protocol download ("loadb" command), and
6184 use "cu" for S-Record download ("loads" command). See
6185 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6186 for help with kermit.
6189 Nevertheless, if you absolutely want to use it try adding this
6190 configuration to your "File transfer protocols" section:
6192 Name Program Name U/D FullScr IO-Red. Multi
6193 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6194 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6200 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6201 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6203 Building requires a cross environment; it is known to work on
6204 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6205 need gmake since the Makefiles are not compatible with BSD make).
6206 Note that the cross-powerpc package does not install include files;
6207 attempting to build U-Boot will fail because <machine/ansi.h> is
6208 missing. This file has to be installed and patched manually:
6210 # cd /usr/pkg/cross/powerpc-netbsd/include
6212 # ln -s powerpc machine
6213 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6214 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6216 Native builds *don't* work due to incompatibilities between native
6217 and U-Boot include files.
6219 Booting assumes that (the first part of) the image booted is a
6220 stage-2 loader which in turn loads and then invokes the kernel
6221 proper. Loader sources will eventually appear in the NetBSD source
6222 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6223 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6226 Implementation Internals:
6227 =========================
6229 The following is not intended to be a complete description of every
6230 implementation detail. However, it should help to understand the
6231 inner workings of U-Boot and make it easier to port it to custom
6235 Initial Stack, Global Data:
6236 ---------------------------
6238 The implementation of U-Boot is complicated by the fact that U-Boot
6239 starts running out of ROM (flash memory), usually without access to
6240 system RAM (because the memory controller is not initialized yet).
6241 This means that we don't have writable Data or BSS segments, and BSS
6242 is not initialized as zero. To be able to get a C environment working
6243 at all, we have to allocate at least a minimal stack. Implementation
6244 options for this are defined and restricted by the CPU used: Some CPU
6245 models provide on-chip memory (like the IMMR area on MPC8xx and
6246 MPC826x processors), on others (parts of) the data cache can be
6247 locked as (mis-) used as memory, etc.
6249 Chris Hallinan posted a good summary of these issues to the
6250 U-Boot mailing list:
6252 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6253 From: "Chris Hallinan" <clh@net1plus.com>
6254 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6257 Correct me if I'm wrong, folks, but the way I understand it
6258 is this: Using DCACHE as initial RAM for Stack, etc, does not
6259 require any physical RAM backing up the cache. The cleverness
6260 is that the cache is being used as a temporary supply of
6261 necessary storage before the SDRAM controller is setup. It's
6262 beyond the scope of this list to explain the details, but you
6263 can see how this works by studying the cache architecture and
6264 operation in the architecture and processor-specific manuals.
6266 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6267 is another option for the system designer to use as an
6268 initial stack/RAM area prior to SDRAM being available. Either
6269 option should work for you. Using CS 4 should be fine if your
6270 board designers haven't used it for something that would
6271 cause you grief during the initial boot! It is frequently not
6274 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6275 with your processor/board/system design. The default value
6276 you will find in any recent u-boot distribution in
6277 walnut.h should work for you. I'd set it to a value larger
6278 than your SDRAM module. If you have a 64MB SDRAM module, set
6279 it above 400_0000. Just make sure your board has no resources
6280 that are supposed to respond to that address! That code in
6281 start.S has been around a while and should work as is when
6282 you get the config right.
6287 It is essential to remember this, since it has some impact on the C
6288 code for the initialization procedures:
6290 * Initialized global data (data segment) is read-only. Do not attempt
6293 * Do not use any uninitialized global data (or implicitly initialized
6294 as zero data - BSS segment) at all - this is undefined, initiali-
6295 zation is performed later (when relocating to RAM).
6297 * Stack space is very limited. Avoid big data buffers or things like
6300 Having only the stack as writable memory limits means we cannot use
6301 normal global data to share information between the code. But it
6302 turned out that the implementation of U-Boot can be greatly
6303 simplified by making a global data structure (gd_t) available to all
6304 functions. We could pass a pointer to this data as argument to _all_
6305 functions, but this would bloat the code. Instead we use a feature of
6306 the GCC compiler (Global Register Variables) to share the data: we
6307 place a pointer (gd) to the global data into a register which we
6308 reserve for this purpose.
6310 When choosing a register for such a purpose we are restricted by the
6311 relevant (E)ABI specifications for the current architecture, and by
6312 GCC's implementation.
6314 For PowerPC, the following registers have specific use:
6316 R2: reserved for system use
6317 R3-R4: parameter passing and return values
6318 R5-R10: parameter passing
6319 R13: small data area pointer
6323 (U-Boot also uses R12 as internal GOT pointer. r12
6324 is a volatile register so r12 needs to be reset when
6325 going back and forth between asm and C)
6327 ==> U-Boot will use R2 to hold a pointer to the global data
6329 Note: on PPC, we could use a static initializer (since the
6330 address of the global data structure is known at compile time),
6331 but it turned out that reserving a register results in somewhat
6332 smaller code - although the code savings are not that big (on
6333 average for all boards 752 bytes for the whole U-Boot image,
6334 624 text + 127 data).
6336 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6337 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6339 ==> U-Boot will use P3 to hold a pointer to the global data
6341 On ARM, the following registers are used:
6343 R0: function argument word/integer result
6344 R1-R3: function argument word
6345 R9: platform specific
6346 R10: stack limit (used only if stack checking is enabled)
6347 R11: argument (frame) pointer
6348 R12: temporary workspace
6351 R15: program counter
6353 ==> U-Boot will use R9 to hold a pointer to the global data
6355 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6357 On Nios II, the ABI is documented here:
6358 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6360 ==> U-Boot will use gp to hold a pointer to the global data
6362 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6363 to access small data sections, so gp is free.
6365 On NDS32, the following registers are used:
6367 R0-R1: argument/return
6369 R15: temporary register for assembler
6370 R16: trampoline register
6371 R28: frame pointer (FP)
6372 R29: global pointer (GP)
6373 R30: link register (LP)
6374 R31: stack pointer (SP)
6375 PC: program counter (PC)
6377 ==> U-Boot will use R10 to hold a pointer to the global data
6379 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6380 or current versions of GCC may "optimize" the code too much.
6385 U-Boot runs in system state and uses physical addresses, i.e. the
6386 MMU is not used either for address mapping nor for memory protection.
6388 The available memory is mapped to fixed addresses using the memory
6389 controller. In this process, a contiguous block is formed for each
6390 memory type (Flash, SDRAM, SRAM), even when it consists of several
6391 physical memory banks.
6393 U-Boot is installed in the first 128 kB of the first Flash bank (on
6394 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6395 booting and sizing and initializing DRAM, the code relocates itself
6396 to the upper end of DRAM. Immediately below the U-Boot code some
6397 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6398 configuration setting]. Below that, a structure with global Board
6399 Info data is placed, followed by the stack (growing downward).
6401 Additionally, some exception handler code is copied to the low 8 kB
6402 of DRAM (0x00000000 ... 0x00001FFF).
6404 So a typical memory configuration with 16 MB of DRAM could look like
6407 0x0000 0000 Exception Vector code
6410 0x0000 2000 Free for Application Use
6416 0x00FB FF20 Monitor Stack (Growing downward)
6417 0x00FB FFAC Board Info Data and permanent copy of global data
6418 0x00FC 0000 Malloc Arena
6421 0x00FE 0000 RAM Copy of Monitor Code
6422 ... eventually: LCD or video framebuffer
6423 ... eventually: pRAM (Protected RAM - unchanged by reset)
6424 0x00FF FFFF [End of RAM]
6427 System Initialization:
6428 ----------------------
6430 In the reset configuration, U-Boot starts at the reset entry point
6431 (on most PowerPC systems at address 0x00000100). Because of the reset
6432 configuration for CS0# this is a mirror of the on board Flash memory.
6433 To be able to re-map memory U-Boot then jumps to its link address.
6434 To be able to implement the initialization code in C, a (small!)
6435 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6436 which provide such a feature like MPC8xx or MPC8260), or in a locked
6437 part of the data cache. After that, U-Boot initializes the CPU core,
6438 the caches and the SIU.
6440 Next, all (potentially) available memory banks are mapped using a
6441 preliminary mapping. For example, we put them on 512 MB boundaries
6442 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6443 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6444 programmed for SDRAM access. Using the temporary configuration, a
6445 simple memory test is run that determines the size of the SDRAM
6448 When there is more than one SDRAM bank, and the banks are of
6449 different size, the largest is mapped first. For equal size, the first
6450 bank (CS2#) is mapped first. The first mapping is always for address
6451 0x00000000, with any additional banks following immediately to create
6452 contiguous memory starting from 0.
6454 Then, the monitor installs itself at the upper end of the SDRAM area
6455 and allocates memory for use by malloc() and for the global Board
6456 Info data; also, the exception vector code is copied to the low RAM
6457 pages, and the final stack is set up.
6459 Only after this relocation will you have a "normal" C environment;
6460 until that you are restricted in several ways, mostly because you are
6461 running from ROM, and because the code will have to be relocated to a
6465 U-Boot Porting Guide:
6466 ----------------------
6468 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6472 int main(int argc, char *argv[])
6474 sighandler_t no_more_time;
6476 signal(SIGALRM, no_more_time);
6477 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6479 if (available_money > available_manpower) {
6480 Pay consultant to port U-Boot;
6484 Download latest U-Boot source;
6486 Subscribe to u-boot mailing list;
6489 email("Hi, I am new to U-Boot, how do I get started?");
6492 Read the README file in the top level directory;
6493 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6494 Read applicable doc/*.README;
6495 Read the source, Luke;
6496 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6499 if (available_money > toLocalCurrency ($2500))
6502 Add a lot of aggravation and time;
6504 if (a similar board exists) { /* hopefully... */
6505 cp -a board/<similar> board/<myboard>
6506 cp include/configs/<similar>.h include/configs/<myboard>.h
6508 Create your own board support subdirectory;
6509 Create your own board include/configs/<myboard>.h file;
6511 Edit new board/<myboard> files
6512 Edit new include/configs/<myboard>.h
6517 Add / modify source code;
6521 email("Hi, I am having problems...");
6523 Send patch file to the U-Boot email list;
6524 if (reasonable critiques)
6525 Incorporate improvements from email list code review;
6527 Defend code as written;
6533 void no_more_time (int sig)
6542 All contributions to U-Boot should conform to the Linux kernel
6543 coding style; see the file "Documentation/CodingStyle" and the script
6544 "scripts/Lindent" in your Linux kernel source directory.
6546 Source files originating from a different project (for example the
6547 MTD subsystem) are generally exempt from these guidelines and are not
6548 reformatted to ease subsequent migration to newer versions of those
6551 Please note that U-Boot is implemented in C (and to some small parts in
6552 Assembler); no C++ is used, so please do not use C++ style comments (//)
6555 Please also stick to the following formatting rules:
6556 - remove any trailing white space
6557 - use TAB characters for indentation and vertical alignment, not spaces
6558 - make sure NOT to use DOS '\r\n' line feeds
6559 - do not add more than 2 consecutive empty lines to source files
6560 - do not add trailing empty lines to source files
6562 Submissions which do not conform to the standards may be returned
6563 with a request to reformat the changes.
6569 Since the number of patches for U-Boot is growing, we need to
6570 establish some rules. Submissions which do not conform to these rules
6571 may be rejected, even when they contain important and valuable stuff.
6573 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6575 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6576 see http://lists.denx.de/mailman/listinfo/u-boot
6578 When you send a patch, please include the following information with
6581 * For bug fixes: a description of the bug and how your patch fixes
6582 this bug. Please try to include a way of demonstrating that the
6583 patch actually fixes something.
6585 * For new features: a description of the feature and your
6588 * A CHANGELOG entry as plaintext (separate from the patch)
6590 * For major contributions, add a MAINTAINERS file with your
6591 information and associated file and directory references.
6593 * When you add support for a new board, don't forget to add a
6594 maintainer e-mail address to the boards.cfg file, too.
6596 * If your patch adds new configuration options, don't forget to
6597 document these in the README file.
6599 * The patch itself. If you are using git (which is *strongly*
6600 recommended) you can easily generate the patch using the
6601 "git format-patch". If you then use "git send-email" to send it to
6602 the U-Boot mailing list, you will avoid most of the common problems
6603 with some other mail clients.
6605 If you cannot use git, use "diff -purN OLD NEW". If your version of
6606 diff does not support these options, then get the latest version of
6609 The current directory when running this command shall be the parent
6610 directory of the U-Boot source tree (i. e. please make sure that
6611 your patch includes sufficient directory information for the
6614 We prefer patches as plain text. MIME attachments are discouraged,
6615 and compressed attachments must not be used.
6617 * If one logical set of modifications affects or creates several
6618 files, all these changes shall be submitted in a SINGLE patch file.
6620 * Changesets that contain different, unrelated modifications shall be
6621 submitted as SEPARATE patches, one patch per changeset.
6626 * Before sending the patch, run the MAKEALL script on your patched
6627 source tree and make sure that no errors or warnings are reported
6628 for any of the boards.
6630 * Keep your modifications to the necessary minimum: A patch
6631 containing several unrelated changes or arbitrary reformats will be
6632 returned with a request to re-formatting / split it.
6634 * If you modify existing code, make sure that your new code does not
6635 add to the memory footprint of the code ;-) Small is beautiful!
6636 When adding new features, these should compile conditionally only
6637 (using #ifdef), and the resulting code with the new feature
6638 disabled must not need more memory than the old code without your
6641 * Remember that there is a size limit of 100 kB per message on the
6642 u-boot mailing list. Bigger patches will be moderated. If they are
6643 reasonable and not too big, they will be acknowledged. But patches
6644 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob