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 candidate 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 /m68k Files generic to m68k architecture
140 /microblaze Files generic to microblaze architecture
141 /mips Files generic to MIPS architecture
142 /nds32 Files generic to NDS32 architecture
143 /nios2 Files generic to Altera NIOS2 architecture
144 /openrisc Files generic to OpenRISC architecture
145 /powerpc Files generic to PowerPC architecture
146 /sandbox Files generic to HW-independent "sandbox"
147 /sh Files generic to SH architecture
148 /x86 Files generic to x86 architecture
149 /api Machine/arch independent API for external apps
150 /board Board dependent files
151 /cmd U-Boot commands functions
152 /common Misc architecture independent functions
153 /configs Board default configuration files
154 /disk Code for disk drive partition handling
155 /doc Documentation (don't expect too much)
156 /drivers Commonly used device drivers
157 /dts Contains Makefile for building internal U-Boot fdt.
158 /examples Example code for standalone applications, etc.
159 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
160 /include Header Files
161 /lib Library routines generic to all architectures
162 /Licenses Various license files
164 /post Power On Self Test
165 /scripts Various build scripts and Makefiles
166 /test Various unit test files
167 /tools Tools to build S-Record or U-Boot images, etc.
169 Software Configuration:
170 =======================
172 Configuration is usually done using C preprocessor defines; the
173 rationale behind that is to avoid dead code whenever possible.
175 There are two classes of configuration variables:
177 * Configuration _OPTIONS_:
178 These are selectable by the user and have names beginning with
181 * Configuration _SETTINGS_:
182 These depend on the hardware etc. and should not be meddled with if
183 you don't know what you're doing; they have names beginning with
186 Previously, all configuration was done by hand, which involved creating
187 symbolic links and editing configuration files manually. More recently,
188 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
189 allowing you to use the "make menuconfig" command to configure your
193 Selection of Processor Architecture and Board Type:
194 ---------------------------------------------------
196 For all supported boards there are ready-to-use default
197 configurations available; just type "make <board_name>_defconfig".
199 Example: For a TQM823L module type:
202 make TQM823L_defconfig
204 Note: If you're looking for the default configuration file for a board
205 you're sure used to be there but is now missing, check the file
206 doc/README.scrapyard for a list of no longer supported boards.
211 U-Boot can be built natively to run on a Linux host using the 'sandbox'
212 board. This allows feature development which is not board- or architecture-
213 specific to be undertaken on a native platform. The sandbox is also used to
214 run some of U-Boot's tests.
216 See board/sandbox/README.sandbox for more details.
219 Board Initialisation Flow:
220 --------------------------
222 This is the intended start-up flow for boards. This should apply for both
223 SPL and U-Boot proper (i.e. they both follow the same rules).
225 Note: "SPL" stands for "Secondary Program Loader," which is explained in
226 more detail later in this file.
228 At present, SPL mostly uses a separate code path, but the function names
229 and roles of each function are the same. Some boards or architectures
230 may not conform to this. At least most ARM boards which use
231 CONFIG_SPL_FRAMEWORK conform to this.
233 Execution typically starts with an architecture-specific (and possibly
234 CPU-specific) start.S file, such as:
236 - arch/arm/cpu/armv7/start.S
237 - arch/powerpc/cpu/mpc83xx/start.S
238 - arch/mips/cpu/start.S
240 and so on. From there, three functions are called; the purpose and
241 limitations of each of these functions are described below.
244 - purpose: essential init to permit execution to reach board_init_f()
245 - no global_data or BSS
246 - there is no stack (ARMv7 may have one but it will soon be removed)
247 - must not set up SDRAM or use console
248 - must only do the bare minimum to allow execution to continue to
250 - this is almost never needed
251 - return normally from this function
254 - purpose: set up the machine ready for running board_init_r():
255 i.e. SDRAM and serial UART
256 - global_data is available
258 - BSS is not available, so you cannot use global/static variables,
259 only stack variables and global_data
261 Non-SPL-specific notes:
262 - dram_init() is called to set up DRAM. If already done in SPL this
266 - you can override the entire board_init_f() function with your own
268 - preloader_console_init() can be called here in extremis
269 - should set up SDRAM, and anything needed to make the UART work
270 - these is no need to clear BSS, it will be done by crt0.S
271 - must return normally from this function (don't call board_init_r()
274 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
275 this point the stack and global_data are relocated to below
276 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
280 - purpose: main execution, common code
281 - global_data is available
283 - BSS is available, all static/global variables can be used
284 - execution eventually continues to main_loop()
286 Non-SPL-specific notes:
287 - U-Boot is relocated to the top of memory and is now running from
291 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
292 CONFIG_SPL_STACK_R_ADDR points into SDRAM
293 - preloader_console_init() can be called here - typically this is
294 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
295 spl_board_init() function containing this call
296 - loads U-Boot or (in falcon mode) Linux
300 Configuration Options:
301 ----------------------
303 Configuration depends on the combination of board and CPU type; all
304 such information is kept in a configuration file
305 "include/configs/<board_name>.h".
307 Example: For a TQM823L module, all configuration settings are in
308 "include/configs/TQM823L.h".
311 Many of the options are named exactly as the corresponding Linux
312 kernel configuration options. The intention is to make it easier to
313 build a config tool - later.
316 The following options need to be configured:
318 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
320 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
322 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
330 Specifies that the core is a 64-bit PowerPC implementation (implements
331 the "64" category of the Power ISA). This is necessary for ePAPR
332 compliance, among other possible reasons.
334 CONFIG_SYS_FSL_TBCLK_DIV
336 Defines the core time base clock divider ratio compared to the
337 system clock. On most PQ3 devices this is 8, on newer QorIQ
338 devices it can be 16 or 32. The ratio varies from SoC to Soc.
340 CONFIG_SYS_FSL_PCIE_COMPAT
342 Defines the string to utilize when trying to match PCIe device
343 tree nodes for the given platform.
345 CONFIG_SYS_FSL_ERRATUM_A004510
347 Enables a workaround for erratum A004510. If set,
348 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
351 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
352 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
354 Defines one or two SoC revisions (low 8 bits of SVR)
355 for which the A004510 workaround should be applied.
357 The rest of SVR is either not relevant to the decision
358 of whether the erratum is present (e.g. p2040 versus
359 p2041) or is implied by the build target, which controls
360 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
362 See Freescale App Note 4493 for more information about
365 CONFIG_A003399_NOR_WORKAROUND
366 Enables a workaround for IFC erratum A003399. It is only
367 required during NOR boot.
369 CONFIG_A008044_WORKAROUND
370 Enables a workaround for T1040/T1042 erratum A008044. It is only
371 required during NAND boot and valid for Rev 1.0 SoC revision
373 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
375 This is the value to write into CCSR offset 0x18600
376 according to the A004510 workaround.
378 CONFIG_SYS_FSL_DSP_DDR_ADDR
379 This value denotes start offset of DDR memory which is
380 connected exclusively to the DSP cores.
382 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
383 This value denotes start offset of M2 memory
384 which is directly connected to the DSP core.
386 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
387 This value denotes start offset of M3 memory which is directly
388 connected to the DSP core.
390 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
391 This value denotes start offset of DSP CCSR space.
393 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
394 Single Source Clock is clocking mode present in some of FSL SoC's.
395 In this mode, a single differential clock is used to supply
396 clocks to the sysclock, ddrclock and usbclock.
398 CONFIG_SYS_CPC_REINIT_F
399 This CONFIG is defined when the CPC is configured as SRAM at the
400 time of U-Boot entry and is required to be re-initialized.
403 Indicates this SoC supports deep sleep feature. If deep sleep is
404 supported, core will start to execute uboot when wakes up.
406 - Generic CPU options:
407 CONFIG_SYS_GENERIC_GLOBAL_DATA
408 Defines global data is initialized in generic board board_init_f().
409 If this macro is defined, global data is created and cleared in
410 generic board board_init_f(). Without this macro, architecture/board
411 should initialize global data before calling board_init_f().
413 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
415 Defines the endianess of the CPU. Implementation of those
416 values is arch specific.
419 Freescale DDR driver in use. This type of DDR controller is
420 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
423 CONFIG_SYS_FSL_DDR_ADDR
424 Freescale DDR memory-mapped register base.
426 CONFIG_SYS_FSL_DDR_EMU
427 Specify emulator support for DDR. Some DDR features such as
428 deskew training are not available.
430 CONFIG_SYS_FSL_DDRC_GEN1
431 Freescale DDR1 controller.
433 CONFIG_SYS_FSL_DDRC_GEN2
434 Freescale DDR2 controller.
436 CONFIG_SYS_FSL_DDRC_GEN3
437 Freescale DDR3 controller.
439 CONFIG_SYS_FSL_DDRC_GEN4
440 Freescale DDR4 controller.
442 CONFIG_SYS_FSL_DDRC_ARM_GEN3
443 Freescale DDR3 controller for ARM-based SoCs.
446 Board config to use DDR1. It can be enabled for SoCs with
447 Freescale DDR1 or DDR2 controllers, depending on the board
451 Board config to use DDR2. It can be enabled for SoCs with
452 Freescale DDR2 or DDR3 controllers, depending on the board
456 Board config to use DDR3. It can be enabled for SoCs with
457 Freescale DDR3 or DDR3L controllers.
460 Board config to use DDR3L. It can be enabled for SoCs with
464 Board config to use DDR4. It can be enabled for SoCs with
467 CONFIG_SYS_FSL_IFC_BE
468 Defines the IFC controller register space as Big Endian
470 CONFIG_SYS_FSL_IFC_LE
471 Defines the IFC controller register space as Little Endian
473 CONFIG_SYS_FSL_IFC_CLK_DIV
474 Defines divider of platform clock(clock input to IFC controller).
476 CONFIG_SYS_FSL_LBC_CLK_DIV
477 Defines divider of platform clock(clock input to eLBC controller).
479 CONFIG_SYS_FSL_PBL_PBI
480 It enables addition of RCW (Power on reset configuration) in built image.
481 Please refer doc/README.pblimage for more details
483 CONFIG_SYS_FSL_PBL_RCW
484 It adds PBI(pre-boot instructions) commands in u-boot build image.
485 PBI commands can be used to configure SoC before it starts the execution.
486 Please refer doc/README.pblimage for more details
489 It adds a target to create boot binary having SPL binary in PBI format
490 concatenated with u-boot binary.
492 CONFIG_SYS_FSL_DDR_BE
493 Defines the DDR controller register space as Big Endian
495 CONFIG_SYS_FSL_DDR_LE
496 Defines the DDR controller register space as Little Endian
498 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
499 Physical address from the view of DDR controllers. It is the
500 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
501 it could be different for ARM SoCs.
503 CONFIG_SYS_FSL_DDR_INTLV_256B
504 DDR controller interleaving on 256-byte. This is a special
505 interleaving mode, handled by Dickens for Freescale layerscape
508 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
509 Number of controllers used as main memory.
511 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
512 Number of controllers used for other than main memory.
514 CONFIG_SYS_FSL_HAS_DP_DDR
515 Defines the SoC has DP-DDR used for DPAA.
517 CONFIG_SYS_FSL_SEC_BE
518 Defines the SEC controller register space as Big Endian
520 CONFIG_SYS_FSL_SEC_LE
521 Defines the SEC controller register space as Little Endian
524 CONFIG_SYS_INIT_SP_OFFSET
526 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
527 pointer. This is needed for the temporary stack before
530 CONFIG_SYS_MIPS_CACHE_MODE
532 Cache operation mode for the MIPS CPU.
533 See also arch/mips/include/asm/mipsregs.h.
535 CONF_CM_CACHABLE_NO_WA
538 CONF_CM_CACHABLE_NONCOHERENT
542 CONF_CM_CACHABLE_ACCELERATED
544 CONFIG_SYS_XWAY_EBU_BOOTCFG
546 Special option for Lantiq XWAY SoCs for booting from NOR flash.
547 See also arch/mips/cpu/mips32/start.S.
549 CONFIG_XWAY_SWAP_BYTES
551 Enable compilation of tools/xway-swap-bytes needed for Lantiq
552 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
553 be swapped if a flash programmer is used.
556 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
558 Select high exception vectors of the ARM core, e.g., do not
559 clear the V bit of the c1 register of CP15.
562 Generic timer clock source frequency.
564 COUNTER_FREQUENCY_REAL
565 Generic timer clock source frequency if the real clock is
566 different from COUNTER_FREQUENCY, and can only be determined
570 CONFIG_TEGRA_SUPPORT_NON_SECURE
572 Support executing U-Boot in non-secure (NS) mode. Certain
573 impossible actions will be skipped if the CPU is in NS mode,
574 such as ARM architectural timer initialization.
576 - Linux Kernel Interface:
579 U-Boot stores all clock information in Hz
580 internally. For binary compatibility with older Linux
581 kernels (which expect the clocks passed in the
582 bd_info data to be in MHz) the environment variable
583 "clocks_in_mhz" can be defined so that U-Boot
584 converts clock data to MHZ before passing it to the
586 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
587 "clocks_in_mhz=1" is automatically included in the
590 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
592 When transferring memsize parameter to Linux, some versions
593 expect it to be in bytes, others in MB.
594 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
598 New kernel versions are expecting firmware settings to be
599 passed using flattened device trees (based on open firmware
603 * New libfdt-based support
604 * Adds the "fdt" command
605 * The bootm command automatically updates the fdt
607 OF_TBCLK - The timebase frequency.
608 OF_STDOUT_PATH - The path to the console device
610 boards with QUICC Engines require OF_QE to set UCC MAC
613 CONFIG_OF_BOARD_SETUP
615 Board code has addition modification that it wants to make
616 to the flat device tree before handing it off to the kernel
618 CONFIG_OF_SYSTEM_SETUP
620 Other code has addition modification that it wants to make
621 to the flat device tree before handing it off to the kernel.
622 This causes ft_system_setup() to be called before booting
627 U-Boot can detect if an IDE device is present or not.
628 If not, and this new config option is activated, U-Boot
629 removes the ATA node from the DTS before booting Linux,
630 so the Linux IDE driver does not probe the device and
631 crash. This is needed for buggy hardware (uc101) where
632 no pull down resistor is connected to the signal IDE5V_DD7.
634 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
636 This setting is mandatory for all boards that have only one
637 machine type and must be used to specify the machine type
638 number as it appears in the ARM machine registry
639 (see http://www.arm.linux.org.uk/developer/machines/).
640 Only boards that have multiple machine types supported
641 in a single configuration file and the machine type is
642 runtime discoverable, do not have to use this setting.
644 - vxWorks boot parameters:
646 bootvx constructs a valid bootline using the following
647 environments variables: bootdev, bootfile, ipaddr, netmask,
648 serverip, gatewayip, hostname, othbootargs.
649 It loads the vxWorks image pointed bootfile.
651 Note: If a "bootargs" environment is defined, it will overwride
652 the defaults discussed just above.
654 - Cache Configuration:
655 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
656 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
657 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
659 - Cache Configuration for ARM:
660 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
662 CONFIG_SYS_PL310_BASE - Physical base address of PL310
663 controller register space
668 Define this if you want support for Amba PrimeCell PL010 UARTs.
672 Define this if you want support for Amba PrimeCell PL011 UARTs.
676 If you have Amba PrimeCell PL011 UARTs, set this variable to
677 the clock speed of the UARTs.
681 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
682 define this to a list of base addresses for each (supported)
683 port. See e.g. include/configs/versatile.h
685 CONFIG_SERIAL_HW_FLOW_CONTROL
687 Define this variable to enable hw flow control in serial driver.
688 Current user of this option is drivers/serial/nsl16550.c driver
691 CONFIG_BAUDRATE - in bps
692 Select one of the baudrates listed in
693 CONFIG_SYS_BAUDRATE_TABLE, see below.
697 Only needed when CONFIG_BOOTDELAY is enabled;
698 define a command string that is automatically executed
699 when no character is read on the console interface
700 within "Boot Delay" after reset.
703 This can be used to pass arguments to the bootm
704 command. The value of CONFIG_BOOTARGS goes into the
705 environment value "bootargs".
707 CONFIG_RAMBOOT and CONFIG_NFSBOOT
708 The value of these goes into the environment as
709 "ramboot" and "nfsboot" respectively, and can be used
710 as a convenience, when switching between booting from
714 CONFIG_BOOTCOUNT_LIMIT
715 Implements a mechanism for detecting a repeating reboot
717 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
720 If no softreset save registers are found on the hardware
721 "bootcount" is stored in the environment. To prevent a
722 saveenv on all reboots, the environment variable
723 "upgrade_available" is used. If "upgrade_available" is
724 0, "bootcount" is always 0, if "upgrade_available" is
725 1 "bootcount" is incremented in the environment.
726 So the Userspace Applikation must set the "upgrade_available"
727 and "bootcount" variable to 0, if a boot was successfully.
732 When this option is #defined, the existence of the
733 environment variable "preboot" will be checked
734 immediately before starting the CONFIG_BOOTDELAY
735 countdown and/or running the auto-boot command resp.
736 entering interactive mode.
738 This feature is especially useful when "preboot" is
739 automatically generated or modified. For an example
740 see the LWMON board specific code: here "preboot" is
741 modified when the user holds down a certain
742 combination of keys on the (special) keyboard when
745 - Serial Download Echo Mode:
747 If defined to 1, all characters received during a
748 serial download (using the "loads" command) are
749 echoed back. This might be needed by some terminal
750 emulations (like "cu"), but may as well just take
751 time on others. This setting #define's the initial
752 value of the "loads_echo" environment variable.
754 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
756 Select one of the baudrates listed in
757 CONFIG_SYS_BAUDRATE_TABLE, see below.
760 Monitor commands can be included or excluded
761 from the build by using the #include files
762 <config_cmd_all.h> and #undef'ing unwanted
763 commands, or adding #define's for wanted commands.
765 The default command configuration includes all commands
766 except those marked below with a "*".
768 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
769 CONFIG_CMD_ASKENV * ask for env variable
770 CONFIG_CMD_BDI bdinfo
771 CONFIG_CMD_BOOTD bootd
772 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
773 CONFIG_CMD_CACHE * icache, dcache
774 CONFIG_CMD_CONSOLE coninfo
775 CONFIG_CMD_DHCP * DHCP support
776 CONFIG_CMD_DIAG * Diagnostics
777 CONFIG_CMD_ECHO echo arguments
778 CONFIG_CMD_EDITENV edit env variable
779 CONFIG_CMD_ELF * bootelf, bootvx
780 CONFIG_CMD_ENV_EXISTS * check existence of env variable
781 CONFIG_CMD_EXPORTENV * export the environment
782 CONFIG_CMD_EXT2 * ext2 command support
783 CONFIG_CMD_EXT4 * ext4 command support
784 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
785 that work for multiple fs types
786 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
787 CONFIG_CMD_SAVEENV saveenv
788 CONFIG_CMD_FLASH flinfo, erase, protect
789 CONFIG_CMD_FPGA FPGA device initialization support
790 CONFIG_CMD_GO * the 'go' command (exec code)
791 CONFIG_CMD_GREPENV * search environment
792 CONFIG_CMD_I2C * I2C serial bus support
793 CONFIG_CMD_IMI iminfo
794 CONFIG_CMD_IMLS List all images found in NOR flash
795 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
796 CONFIG_CMD_IMPORTENV * import an environment
797 CONFIG_CMD_INI * import data from an ini file into the env
798 CONFIG_CMD_ITEST Integer/string test of 2 values
799 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
800 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
802 CONFIG_CMD_LOADB loadb
803 CONFIG_CMD_LOADS loads
804 CONFIG_CMD_MD5SUM * print md5 message digest
805 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
806 CONFIG_CMD_MEMINFO * Display detailed memory information
807 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
809 CONFIG_CMD_MEMTEST * mtest
810 CONFIG_CMD_MISC Misc functions like sleep etc
811 CONFIG_CMD_MMC * MMC memory mapped support
812 CONFIG_CMD_MII * MII utility commands
813 CONFIG_CMD_MTDPARTS * MTD partition support
814 CONFIG_CMD_NAND * NAND support
815 CONFIG_CMD_NET bootp, tftpboot, rarpboot
816 CONFIG_CMD_NFS NFS support
817 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
818 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
819 CONFIG_CMD_PCI * pciinfo
820 CONFIG_CMD_PCMCIA * PCMCIA support
821 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
823 CONFIG_CMD_PORTIO * Port I/O
824 CONFIG_CMD_READ * Read raw data from partition
825 CONFIG_CMD_REGINFO * Register dump
826 CONFIG_CMD_RUN run command in env variable
827 CONFIG_CMD_SANDBOX * sb command to access sandbox features
828 CONFIG_CMD_SAVES * save S record dump
829 CONFIG_SCSI * SCSI Support
830 CONFIG_CMD_SDRAM * print SDRAM configuration information
831 (requires CONFIG_CMD_I2C)
832 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
833 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
834 CONFIG_CMD_SOURCE "source" command Support
835 CONFIG_CMD_SPI * SPI serial bus support
836 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
837 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
838 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
839 CONFIG_CMD_TIMER * access to the system tick timer
840 CONFIG_CMD_USB * USB support
841 CONFIG_CMD_CDP * Cisco Discover Protocol support
842 CONFIG_CMD_MFSL * Microblaze FSL support
843 CONFIG_CMD_XIMG Load part of Multi Image
844 CONFIG_CMD_UUID * Generate random UUID or GUID string
846 EXAMPLE: If you want all functions except of network
847 support you can write:
849 #include "config_cmd_all.h"
850 #undef CONFIG_CMD_NET
853 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
855 Note: Don't enable the "icache" and "dcache" commands
856 (configuration option CONFIG_CMD_CACHE) unless you know
857 what you (and your U-Boot users) are doing. Data
858 cache cannot be enabled on systems like the
859 8260 (where accesses to the IMMR region must be
860 uncached), and it cannot be disabled on all other
861 systems where we (mis-) use the data cache to hold an
862 initial stack and some data.
865 XXX - this list needs to get updated!
867 - Removal of commands
868 If no commands are needed to boot, you can disable
869 CONFIG_CMDLINE to remove them. In this case, the command line
870 will not be available, and when U-Boot wants to execute the
871 boot command (on start-up) it will call board_run_command()
872 instead. This can reduce image size significantly for very
873 simple boot procedures.
875 - Regular expression support:
877 If this variable is defined, U-Boot is linked against
878 the SLRE (Super Light Regular Expression) library,
879 which adds regex support to some commands, as for
880 example "env grep" and "setexpr".
884 If this variable is defined, U-Boot will use a device tree
885 to configure its devices, instead of relying on statically
886 compiled #defines in the board file. This option is
887 experimental and only available on a few boards. The device
888 tree is available in the global data as gd->fdt_blob.
890 U-Boot needs to get its device tree from somewhere. This can
891 be done using one of the three options below:
894 If this variable is defined, U-Boot will embed a device tree
895 binary in its image. This device tree file should be in the
896 board directory and called <soc>-<board>.dts. The binary file
897 is then picked up in board_init_f() and made available through
898 the global data structure as gd->blob.
901 If this variable is defined, U-Boot will build a device tree
902 binary. It will be called u-boot.dtb. Architecture-specific
903 code will locate it at run-time. Generally this works by:
905 cat u-boot.bin u-boot.dtb >image.bin
907 and in fact, U-Boot does this for you, creating a file called
908 u-boot-dtb.bin which is useful in the common case. You can
909 still use the individual files if you need something more
913 If this variable is defined, U-Boot will use the device tree
914 provided by the board at runtime instead of embedding one with
915 the image. Only boards defining board_fdt_blob_setup() support
916 this option (see include/fdtdec.h file).
920 If this variable is defined, it enables watchdog
921 support for the SoC. There must be support in the SoC
922 specific code for a watchdog. When supported for a
923 specific SoC is available, then no further board specific
924 code should be needed to use it.
927 When using a watchdog circuitry external to the used
928 SoC, then define this variable and provide board
929 specific code for the "hw_watchdog_reset" function.
931 CONFIG_AT91_HW_WDT_TIMEOUT
932 specify the timeout in seconds. default 2 seconds.
935 CONFIG_VERSION_VARIABLE
936 If this variable is defined, an environment variable
937 named "ver" is created by U-Boot showing the U-Boot
938 version as printed by the "version" command.
939 Any change to this variable will be reverted at the
944 When CONFIG_CMD_DATE is selected, the type of the RTC
945 has to be selected, too. Define exactly one of the
948 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
949 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
950 CONFIG_RTC_MC146818 - use MC146818 RTC
951 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
952 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
953 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
954 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
955 CONFIG_RTC_DS164x - use Dallas DS164x RTC
956 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
957 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
958 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
959 CONFIG_SYS_RV3029_TCR - enable trickle charger on
962 Note that if the RTC uses I2C, then the I2C interface
963 must also be configured. See I2C Support, below.
966 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
968 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
969 chip-ngpio pairs that tell the PCA953X driver the number of
970 pins supported by a particular chip.
972 Note that if the GPIO device uses I2C, then the I2C interface
973 must also be configured. See I2C Support, below.
976 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
977 accesses and can checksum them or write a list of them out
978 to memory. See the 'iotrace' command for details. This is
979 useful for testing device drivers since it can confirm that
980 the driver behaves the same way before and after a code
981 change. Currently this is supported on sandbox and arm. To
982 add support for your architecture, add '#include <iotrace.h>'
983 to the bottom of arch/<arch>/include/asm/io.h and test.
985 Example output from the 'iotrace stats' command is below.
986 Note that if the trace buffer is exhausted, the checksum will
987 still continue to operate.
990 Start: 10000000 (buffer start address)
991 Size: 00010000 (buffer size)
992 Offset: 00000120 (current buffer offset)
993 Output: 10000120 (start + offset)
994 Count: 00000018 (number of trace records)
995 CRC32: 9526fb66 (CRC32 of all trace records)
999 When CONFIG_TIMESTAMP is selected, the timestamp
1000 (date and time) of an image is printed by image
1001 commands like bootm or iminfo. This option is
1002 automatically enabled when you select CONFIG_CMD_DATE .
1004 - Partition Labels (disklabels) Supported:
1005 Zero or more of the following:
1006 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1007 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1008 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1009 bootloader. Note 2TB partition limit; see
1011 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1013 If IDE or SCSI support is enabled (CONFIG_IDE or
1014 CONFIG_SCSI) you must configure support for at
1015 least one non-MTD partition type as well.
1018 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1019 board configurations files but used nowhere!
1021 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1022 be performed by calling the function
1023 ide_set_reset(int reset)
1024 which has to be defined in a board specific file
1029 Set this to enable ATAPI support.
1034 Set this to enable support for disks larger than 137GB
1035 Also look at CONFIG_SYS_64BIT_LBA.
1036 Whithout these , LBA48 support uses 32bit variables and will 'only'
1037 support disks up to 2.1TB.
1039 CONFIG_SYS_64BIT_LBA:
1040 When enabled, makes the IDE subsystem use 64bit sector addresses.
1044 At the moment only there is only support for the
1045 SYM53C8XX SCSI controller; define
1046 CONFIG_SCSI_SYM53C8XX to enable it.
1048 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1049 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1050 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1051 maximum numbers of LUNs, SCSI ID's and target
1053 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1055 The environment variable 'scsidevs' is set to the number of
1056 SCSI devices found during the last scan.
1058 - NETWORK Support (PCI):
1060 Support for Intel 8254x/8257x gigabit chips.
1063 Utility code for direct access to the SPI bus on Intel 8257x.
1064 This does not do anything useful unless you set at least one
1065 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1067 CONFIG_E1000_SPI_GENERIC
1068 Allow generic access to the SPI bus on the Intel 8257x, for
1069 example with the "sspi" command.
1072 Management command for E1000 devices. When used on devices
1073 with SPI support you can reprogram the EEPROM from U-Boot.
1076 Support for Intel 82557/82559/82559ER chips.
1077 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1078 write routine for first time initialisation.
1081 Support for Digital 2114x chips.
1082 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1083 modem chip initialisation (KS8761/QS6611).
1086 Support for National dp83815 chips.
1089 Support for National dp8382[01] gigabit chips.
1091 - NETWORK Support (other):
1093 CONFIG_DRIVER_AT91EMAC
1094 Support for AT91RM9200 EMAC.
1097 Define this to use reduced MII inteface
1099 CONFIG_DRIVER_AT91EMAC_QUIET
1100 If this defined, the driver is quiet.
1101 The driver doen't show link status messages.
1103 CONFIG_CALXEDA_XGMAC
1104 Support for the Calxeda XGMAC device
1107 Support for SMSC's LAN91C96 chips.
1109 CONFIG_LAN91C96_USE_32_BIT
1110 Define this to enable 32 bit addressing
1113 Support for SMSC's LAN91C111 chip
1115 CONFIG_SMC91111_BASE
1116 Define this to hold the physical address
1117 of the device (I/O space)
1119 CONFIG_SMC_USE_32_BIT
1120 Define this if data bus is 32 bits
1122 CONFIG_SMC_USE_IOFUNCS
1123 Define this to use i/o functions instead of macros
1124 (some hardware wont work with macros)
1126 CONFIG_DRIVER_TI_EMAC
1127 Support for davinci emac
1129 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1130 Define this if you have more then 3 PHYs.
1133 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1135 CONFIG_FTGMAC100_EGIGA
1136 Define this to use GE link update with gigabit PHY.
1137 Define this if FTGMAC100 is connected to gigabit PHY.
1138 If your system has 10/100 PHY only, it might not occur
1139 wrong behavior. Because PHY usually return timeout or
1140 useless data when polling gigabit status and gigabit
1141 control registers. This behavior won't affect the
1142 correctnessof 10/100 link speed update.
1145 Support for SMSC's LAN911x and LAN921x chips
1148 Define this to hold the physical address
1149 of the device (I/O space)
1151 CONFIG_SMC911X_32_BIT
1152 Define this if data bus is 32 bits
1154 CONFIG_SMC911X_16_BIT
1155 Define this if data bus is 16 bits. If your processor
1156 automatically converts one 32 bit word to two 16 bit
1157 words you may also try CONFIG_SMC911X_32_BIT.
1160 Support for Renesas on-chip Ethernet controller
1162 CONFIG_SH_ETHER_USE_PORT
1163 Define the number of ports to be used
1165 CONFIG_SH_ETHER_PHY_ADDR
1166 Define the ETH PHY's address
1168 CONFIG_SH_ETHER_CACHE_WRITEBACK
1169 If this option is set, the driver enables cache flush.
1173 Support for PWM module on the imx6.
1177 Support TPM devices.
1179 CONFIG_TPM_TIS_INFINEON
1180 Support for Infineon i2c bus TPM devices. Only one device
1181 per system is supported at this time.
1183 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1184 Define the burst count bytes upper limit
1187 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1189 CONFIG_TPM_ST33ZP24_I2C
1190 Support for STMicroelectronics ST33ZP24 I2C devices.
1191 Requires TPM_ST33ZP24 and I2C.
1193 CONFIG_TPM_ST33ZP24_SPI
1194 Support for STMicroelectronics ST33ZP24 SPI devices.
1195 Requires TPM_ST33ZP24 and SPI.
1197 CONFIG_TPM_ATMEL_TWI
1198 Support for Atmel TWI TPM device. Requires I2C support.
1201 Support for generic parallel port TPM devices. Only one device
1202 per system is supported at this time.
1204 CONFIG_TPM_TIS_BASE_ADDRESS
1205 Base address where the generic TPM device is mapped
1206 to. Contemporary x86 systems usually map it at
1210 Add tpm monitor functions.
1211 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1212 provides monitor access to authorized functions.
1215 Define this to enable the TPM support library which provides
1216 functional interfaces to some TPM commands.
1217 Requires support for a TPM device.
1219 CONFIG_TPM_AUTH_SESSIONS
1220 Define this to enable authorized functions in the TPM library.
1221 Requires CONFIG_TPM and CONFIG_SHA1.
1224 At the moment only the UHCI host controller is
1225 supported (PIP405, MIP405); define
1226 CONFIG_USB_UHCI to enable it.
1227 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1228 and define CONFIG_USB_STORAGE to enable the USB
1231 Supported are USB Keyboards and USB Floppy drives
1234 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1235 txfilltuning field in the EHCI controller on reset.
1237 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1238 HW module registers.
1241 Define the below if you wish to use the USB console.
1242 Once firmware is rebuilt from a serial console issue the
1243 command "setenv stdin usbtty; setenv stdout usbtty" and
1244 attach your USB cable. The Unix command "dmesg" should print
1245 it has found a new device. The environment variable usbtty
1246 can be set to gserial or cdc_acm to enable your device to
1247 appear to a USB host as a Linux gserial device or a
1248 Common Device Class Abstract Control Model serial device.
1249 If you select usbtty = gserial you should be able to enumerate
1251 # modprobe usbserial vendor=0xVendorID product=0xProductID
1252 else if using cdc_acm, simply setting the environment
1253 variable usbtty to be cdc_acm should suffice. The following
1254 might be defined in YourBoardName.h
1257 Define this to build a UDC device
1260 Define this to have a tty type of device available to
1261 talk to the UDC device
1264 Define this to enable the high speed support for usb
1265 device and usbtty. If this feature is enabled, a routine
1266 int is_usbd_high_speed(void)
1267 also needs to be defined by the driver to dynamically poll
1268 whether the enumeration has succeded at high speed or full
1271 CONFIG_SYS_CONSOLE_IS_IN_ENV
1272 Define this if you want stdin, stdout &/or stderr to
1275 If you have a USB-IF assigned VendorID then you may wish to
1276 define your own vendor specific values either in BoardName.h
1277 or directly in usbd_vendor_info.h. If you don't define
1278 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1279 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1280 should pretend to be a Linux device to it's target host.
1282 CONFIG_USBD_MANUFACTURER
1283 Define this string as the name of your company for
1284 - CONFIG_USBD_MANUFACTURER "my company"
1286 CONFIG_USBD_PRODUCT_NAME
1287 Define this string as the name of your product
1288 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1290 CONFIG_USBD_VENDORID
1291 Define this as your assigned Vendor ID from the USB
1292 Implementors Forum. This *must* be a genuine Vendor ID
1293 to avoid polluting the USB namespace.
1294 - CONFIG_USBD_VENDORID 0xFFFF
1296 CONFIG_USBD_PRODUCTID
1297 Define this as the unique Product ID
1299 - CONFIG_USBD_PRODUCTID 0xFFFF
1301 - ULPI Layer Support:
1302 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1303 the generic ULPI layer. The generic layer accesses the ULPI PHY
1304 via the platform viewport, so you need both the genric layer and
1305 the viewport enabled. Currently only Chipidea/ARC based
1306 viewport is supported.
1307 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1308 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1309 If your ULPI phy needs a different reference clock than the
1310 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1311 the appropriate value in Hz.
1314 The MMC controller on the Intel PXA is supported. To
1315 enable this define CONFIG_MMC. The MMC can be
1316 accessed from the boot prompt by mapping the device
1317 to physical memory similar to flash. Command line is
1318 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1319 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1322 Support for Renesas on-chip MMCIF controller
1324 CONFIG_SH_MMCIF_ADDR
1325 Define the base address of MMCIF registers
1328 Define the clock frequency for MMCIF
1330 CONFIG_SUPPORT_EMMC_BOOT
1331 Enable some additional features of the eMMC boot partitions.
1333 CONFIG_SUPPORT_EMMC_RPMB
1334 Enable the commands for reading, writing and programming the
1335 key for the Replay Protection Memory Block partition in eMMC.
1337 - USB Device Firmware Update (DFU) class support:
1338 CONFIG_USB_FUNCTION_DFU
1339 This enables the USB portion of the DFU USB class
1342 This enables the command "dfu" which is used to have
1343 U-Boot create a DFU class device via USB. This command
1344 requires that the "dfu_alt_info" environment variable be
1345 set and define the alt settings to expose to the host.
1348 This enables support for exposing (e)MMC devices via DFU.
1351 This enables support for exposing NAND devices via DFU.
1354 This enables support for exposing RAM via DFU.
1355 Note: DFU spec refer to non-volatile memory usage, but
1356 allow usages beyond the scope of spec - here RAM usage,
1357 one that would help mostly the developer.
1359 CONFIG_SYS_DFU_DATA_BUF_SIZE
1360 Dfu transfer uses a buffer before writing data to the
1361 raw storage device. Make the size (in bytes) of this buffer
1362 configurable. The size of this buffer is also configurable
1363 through the "dfu_bufsiz" environment variable.
1365 CONFIG_SYS_DFU_MAX_FILE_SIZE
1366 When updating files rather than the raw storage device,
1367 we use a static buffer to copy the file into and then write
1368 the buffer once we've been given the whole file. Define
1369 this to the maximum filesize (in bytes) for the buffer.
1370 Default is 4 MiB if undefined.
1372 DFU_DEFAULT_POLL_TIMEOUT
1373 Poll timeout [ms], is the timeout a device can send to the
1374 host. The host must wait for this timeout before sending
1375 a subsequent DFU_GET_STATUS request to the device.
1377 DFU_MANIFEST_POLL_TIMEOUT
1378 Poll timeout [ms], which the device sends to the host when
1379 entering dfuMANIFEST state. Host waits this timeout, before
1380 sending again an USB request to the device.
1382 - USB Device Android Fastboot support:
1383 CONFIG_USB_FUNCTION_FASTBOOT
1384 This enables the USB part of the fastboot gadget
1387 This enables the command "fastboot" which enables the Android
1388 fastboot mode for the platform's USB device. Fastboot is a USB
1389 protocol for downloading images, flashing and device control
1390 used on Android devices.
1391 See doc/README.android-fastboot for more information.
1393 CONFIG_ANDROID_BOOT_IMAGE
1394 This enables support for booting images which use the Android
1395 image format header.
1397 CONFIG_FASTBOOT_BUF_ADDR
1398 The fastboot protocol requires a large memory buffer for
1399 downloads. Define this to the starting RAM address to use for
1402 CONFIG_FASTBOOT_BUF_SIZE
1403 The fastboot protocol requires a large memory buffer for
1404 downloads. This buffer should be as large as possible for a
1405 platform. Define this to the size available RAM for fastboot.
1407 CONFIG_FASTBOOT_FLASH
1408 The fastboot protocol includes a "flash" command for writing
1409 the downloaded image to a non-volatile storage device. Define
1410 this to enable the "fastboot flash" command.
1412 CONFIG_FASTBOOT_FLASH_MMC_DEV
1413 The fastboot "flash" command requires additional information
1414 regarding the non-volatile storage device. Define this to
1415 the eMMC device that fastboot should use to store the image.
1417 CONFIG_FASTBOOT_GPT_NAME
1418 The fastboot "flash" command supports writing the downloaded
1419 image to the Protective MBR and the Primary GUID Partition
1420 Table. (Additionally, this downloaded image is post-processed
1421 to generate and write the Backup GUID Partition Table.)
1422 This occurs when the specified "partition name" on the
1423 "fastboot flash" command line matches this value.
1424 The default is "gpt" if undefined.
1426 CONFIG_FASTBOOT_MBR_NAME
1427 The fastboot "flash" command supports writing the downloaded
1429 This occurs when the "partition name" specified on the
1430 "fastboot flash" command line matches this value.
1431 If not defined the default value "mbr" is used.
1433 - Journaling Flash filesystem support:
1435 Define these for a default partition on a NAND device
1437 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1438 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1439 Define these for a default partition on a NOR device
1442 See Kconfig help for available keyboard drivers.
1446 Define this to enable a custom keyboard support.
1447 This simply calls drv_keyboard_init() which must be
1448 defined in your board-specific files. This option is deprecated
1449 and is only used by novena. For new boards, use driver model
1454 Enable the Freescale DIU video driver. Reference boards for
1455 SOCs that have a DIU should define this macro to enable DIU
1456 support, and should also define these other macros:
1461 CONFIG_VIDEO_SW_CURSOR
1462 CONFIG_VGA_AS_SINGLE_DEVICE
1464 CONFIG_VIDEO_BMP_LOGO
1466 The DIU driver will look for the 'video-mode' environment
1467 variable, and if defined, enable the DIU as a console during
1468 boot. See the documentation file doc/README.video for a
1469 description of this variable.
1471 - LCD Support: CONFIG_LCD
1473 Define this to enable LCD support (for output to LCD
1474 display); also select one of the supported displays
1475 by defining one of these:
1479 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1481 CONFIG_NEC_NL6448AC33:
1483 NEC NL6448AC33-18. Active, color, single scan.
1485 CONFIG_NEC_NL6448BC20
1487 NEC NL6448BC20-08. 6.5", 640x480.
1488 Active, color, single scan.
1490 CONFIG_NEC_NL6448BC33_54
1492 NEC NL6448BC33-54. 10.4", 640x480.
1493 Active, color, single scan.
1497 Sharp 320x240. Active, color, single scan.
1498 It isn't 16x9, and I am not sure what it is.
1500 CONFIG_SHARP_LQ64D341
1502 Sharp LQ64D341 display, 640x480.
1503 Active, color, single scan.
1507 HLD1045 display, 640x480.
1508 Active, color, single scan.
1512 Optrex CBL50840-2 NF-FW 99 22 M5
1514 Hitachi LMG6912RPFC-00T
1518 320x240. Black & white.
1520 CONFIG_LCD_ALIGNMENT
1522 Normally the LCD is page-aligned (typically 4KB). If this is
1523 defined then the LCD will be aligned to this value instead.
1524 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1525 here, since it is cheaper to change data cache settings on
1526 a per-section basis.
1531 Sometimes, for example if the display is mounted in portrait
1532 mode or even if it's mounted landscape but rotated by 180degree,
1533 we need to rotate our content of the display relative to the
1534 framebuffer, so that user can read the messages which are
1536 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1537 initialized with a given rotation from "vl_rot" out of
1538 "vidinfo_t" which is provided by the board specific code.
1539 The value for vl_rot is coded as following (matching to
1540 fbcon=rotate:<n> linux-kernel commandline):
1541 0 = no rotation respectively 0 degree
1542 1 = 90 degree rotation
1543 2 = 180 degree rotation
1544 3 = 270 degree rotation
1546 If CONFIG_LCD_ROTATION is not defined, the console will be
1547 initialized with 0degree rotation.
1551 Support drawing of RLE8-compressed bitmaps on the LCD.
1555 Enables an 'i2c edid' command which can read EDID
1556 information over I2C from an attached LCD display.
1558 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1560 If this option is set, the environment is checked for
1561 a variable "splashimage". If found, the usual display
1562 of logo, copyright and system information on the LCD
1563 is suppressed and the BMP image at the address
1564 specified in "splashimage" is loaded instead. The
1565 console is redirected to the "nulldev", too. This
1566 allows for a "silent" boot where a splash screen is
1567 loaded very quickly after power-on.
1569 CONFIG_SPLASHIMAGE_GUARD
1571 If this option is set, then U-Boot will prevent the environment
1572 variable "splashimage" from being set to a problematic address
1573 (see doc/README.displaying-bmps).
1574 This option is useful for targets where, due to alignment
1575 restrictions, an improperly aligned BMP image will cause a data
1576 abort. If you think you will not have problems with unaligned
1577 accesses (for example because your toolchain prevents them)
1578 there is no need to set this option.
1580 CONFIG_SPLASH_SCREEN_ALIGN
1582 If this option is set the splash image can be freely positioned
1583 on the screen. Environment variable "splashpos" specifies the
1584 position as "x,y". If a positive number is given it is used as
1585 number of pixel from left/top. If a negative number is given it
1586 is used as number of pixel from right/bottom. You can also
1587 specify 'm' for centering the image.
1590 setenv splashpos m,m
1591 => image at center of screen
1593 setenv splashpos 30,20
1594 => image at x = 30 and y = 20
1596 setenv splashpos -10,m
1597 => vertically centered image
1598 at x = dspWidth - bmpWidth - 9
1600 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1602 If this option is set, additionally to standard BMP
1603 images, gzipped BMP images can be displayed via the
1604 splashscreen support or the bmp command.
1606 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1608 If this option is set, 8-bit RLE compressed BMP images
1609 can be displayed via the splashscreen support or the
1612 - Compression support:
1615 Enabled by default to support gzip compressed images.
1619 If this option is set, support for bzip2 compressed
1620 images is included. If not, only uncompressed and gzip
1621 compressed images are supported.
1623 NOTE: the bzip2 algorithm requires a lot of RAM, so
1624 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1629 If this option is set, support for LZO compressed images
1635 The address of PHY on MII bus.
1637 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1639 The clock frequency of the MII bus
1643 If this option is set, support for speed/duplex
1644 detection of gigabit PHY is included.
1646 CONFIG_PHY_RESET_DELAY
1648 Some PHY like Intel LXT971A need extra delay after
1649 reset before any MII register access is possible.
1650 For such PHY, set this option to the usec delay
1651 required. (minimum 300usec for LXT971A)
1653 CONFIG_PHY_CMD_DELAY (ppc4xx)
1655 Some PHY like Intel LXT971A need extra delay after
1656 command issued before MII status register can be read
1661 Define a default value for the IP address to use for
1662 the default Ethernet interface, in case this is not
1663 determined through e.g. bootp.
1664 (Environment variable "ipaddr")
1666 - Server IP address:
1669 Defines a default value for the IP address of a TFTP
1670 server to contact when using the "tftboot" command.
1671 (Environment variable "serverip")
1673 CONFIG_KEEP_SERVERADDR
1675 Keeps the server's MAC address, in the env 'serveraddr'
1676 for passing to bootargs (like Linux's netconsole option)
1678 - Gateway IP address:
1681 Defines a default value for the IP address of the
1682 default router where packets to other networks are
1684 (Environment variable "gatewayip")
1689 Defines a default value for the subnet mask (or
1690 routing prefix) which is used to determine if an IP
1691 address belongs to the local subnet or needs to be
1692 forwarded through a router.
1693 (Environment variable "netmask")
1695 - Multicast TFTP Mode:
1698 Defines whether you want to support multicast TFTP as per
1699 rfc-2090; for example to work with atftp. Lets lots of targets
1700 tftp down the same boot image concurrently. Note: the Ethernet
1701 driver in use must provide a function: mcast() to join/leave a
1704 - BOOTP Recovery Mode:
1705 CONFIG_BOOTP_RANDOM_DELAY
1707 If you have many targets in a network that try to
1708 boot using BOOTP, you may want to avoid that all
1709 systems send out BOOTP requests at precisely the same
1710 moment (which would happen for instance at recovery
1711 from a power failure, when all systems will try to
1712 boot, thus flooding the BOOTP server. Defining
1713 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1714 inserted before sending out BOOTP requests. The
1715 following delays are inserted then:
1717 1st BOOTP request: delay 0 ... 1 sec
1718 2nd BOOTP request: delay 0 ... 2 sec
1719 3rd BOOTP request: delay 0 ... 4 sec
1721 BOOTP requests: delay 0 ... 8 sec
1723 CONFIG_BOOTP_ID_CACHE_SIZE
1725 BOOTP packets are uniquely identified using a 32-bit ID. The
1726 server will copy the ID from client requests to responses and
1727 U-Boot will use this to determine if it is the destination of
1728 an incoming response. Some servers will check that addresses
1729 aren't in use before handing them out (usually using an ARP
1730 ping) and therefore take up to a few hundred milliseconds to
1731 respond. Network congestion may also influence the time it
1732 takes for a response to make it back to the client. If that
1733 time is too long, U-Boot will retransmit requests. In order
1734 to allow earlier responses to still be accepted after these
1735 retransmissions, U-Boot's BOOTP client keeps a small cache of
1736 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1737 cache. The default is to keep IDs for up to four outstanding
1738 requests. Increasing this will allow U-Boot to accept offers
1739 from a BOOTP client in networks with unusually high latency.
1741 - DHCP Advanced Options:
1742 You can fine tune the DHCP functionality by defining
1743 CONFIG_BOOTP_* symbols:
1745 CONFIG_BOOTP_SUBNETMASK
1746 CONFIG_BOOTP_GATEWAY
1747 CONFIG_BOOTP_HOSTNAME
1748 CONFIG_BOOTP_NISDOMAIN
1749 CONFIG_BOOTP_BOOTPATH
1750 CONFIG_BOOTP_BOOTFILESIZE
1753 CONFIG_BOOTP_SEND_HOSTNAME
1754 CONFIG_BOOTP_NTPSERVER
1755 CONFIG_BOOTP_TIMEOFFSET
1756 CONFIG_BOOTP_VENDOREX
1757 CONFIG_BOOTP_MAY_FAIL
1759 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1760 environment variable, not the BOOTP server.
1762 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1763 after the configured retry count, the call will fail
1764 instead of starting over. This can be used to fail over
1765 to Link-local IP address configuration if the DHCP server
1768 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1769 serverip from a DHCP server, it is possible that more
1770 than one DNS serverip is offered to the client.
1771 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1772 serverip will be stored in the additional environment
1773 variable "dnsip2". The first DNS serverip is always
1774 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1777 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1778 to do a dynamic update of a DNS server. To do this, they
1779 need the hostname of the DHCP requester.
1780 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1781 of the "hostname" environment variable is passed as
1782 option 12 to the DHCP server.
1784 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1786 A 32bit value in microseconds for a delay between
1787 receiving a "DHCP Offer" and sending the "DHCP Request".
1788 This fixes a problem with certain DHCP servers that don't
1789 respond 100% of the time to a "DHCP request". E.g. On an
1790 AT91RM9200 processor running at 180MHz, this delay needed
1791 to be *at least* 15,000 usec before a Windows Server 2003
1792 DHCP server would reply 100% of the time. I recommend at
1793 least 50,000 usec to be safe. The alternative is to hope
1794 that one of the retries will be successful but note that
1795 the DHCP timeout and retry process takes a longer than
1798 - Link-local IP address negotiation:
1799 Negotiate with other link-local clients on the local network
1800 for an address that doesn't require explicit configuration.
1801 This is especially useful if a DHCP server cannot be guaranteed
1802 to exist in all environments that the device must operate.
1804 See doc/README.link-local for more information.
1807 CONFIG_CDP_DEVICE_ID
1809 The device id used in CDP trigger frames.
1811 CONFIG_CDP_DEVICE_ID_PREFIX
1813 A two character string which is prefixed to the MAC address
1818 A printf format string which contains the ascii name of
1819 the port. Normally is set to "eth%d" which sets
1820 eth0 for the first Ethernet, eth1 for the second etc.
1822 CONFIG_CDP_CAPABILITIES
1824 A 32bit integer which indicates the device capabilities;
1825 0x00000010 for a normal host which does not forwards.
1829 An ascii string containing the version of the software.
1833 An ascii string containing the name of the platform.
1837 A 32bit integer sent on the trigger.
1839 CONFIG_CDP_POWER_CONSUMPTION
1841 A 16bit integer containing the power consumption of the
1842 device in .1 of milliwatts.
1844 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1846 A byte containing the id of the VLAN.
1848 - Status LED: CONFIG_LED_STATUS
1850 Several configurations allow to display the current
1851 status using a LED. For instance, the LED will blink
1852 fast while running U-Boot code, stop blinking as
1853 soon as a reply to a BOOTP request was received, and
1854 start blinking slow once the Linux kernel is running
1855 (supported by a status LED driver in the Linux
1856 kernel). Defining CONFIG_LED_STATUS enables this
1861 CONFIG_LED_STATUS_GPIO
1862 The status LED can be connected to a GPIO pin.
1863 In such cases, the gpio_led driver can be used as a
1864 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1865 to include the gpio_led driver in the U-Boot binary.
1867 CONFIG_GPIO_LED_INVERTED_TABLE
1868 Some GPIO connected LEDs may have inverted polarity in which
1869 case the GPIO high value corresponds to LED off state and
1870 GPIO low value corresponds to LED on state.
1871 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1872 with a list of GPIO LEDs that have inverted polarity.
1874 - I2C Support: CONFIG_SYS_I2C
1876 This enable the NEW i2c subsystem, and will allow you to use
1877 i2c commands at the u-boot command line (as long as you set
1878 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1879 based realtime clock chips or other i2c devices. See
1880 common/cmd_i2c.c for a description of the command line
1883 ported i2c driver to the new framework:
1884 - drivers/i2c/soft_i2c.c:
1885 - activate first bus with CONFIG_SYS_I2C_SOFT define
1886 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1887 for defining speed and slave address
1888 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1889 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1890 for defining speed and slave address
1891 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1892 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1893 for defining speed and slave address
1894 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1895 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1896 for defining speed and slave address
1898 - drivers/i2c/fsl_i2c.c:
1899 - activate i2c driver with CONFIG_SYS_I2C_FSL
1900 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1901 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1902 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1904 - If your board supports a second fsl i2c bus, define
1905 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1906 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1907 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1910 - drivers/i2c/tegra_i2c.c:
1911 - activate this driver with CONFIG_SYS_I2C_TEGRA
1912 - This driver adds 4 i2c buses with a fix speed from
1913 100000 and the slave addr 0!
1915 - drivers/i2c/ppc4xx_i2c.c
1916 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1917 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1918 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1920 - drivers/i2c/i2c_mxc.c
1921 - activate this driver with CONFIG_SYS_I2C_MXC
1922 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1923 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1924 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1925 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1926 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1927 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1928 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1929 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1930 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1931 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1932 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1933 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1934 If those defines are not set, default value is 100000
1935 for speed, and 0 for slave.
1937 - drivers/i2c/rcar_i2c.c:
1938 - activate this driver with CONFIG_SYS_I2C_RCAR
1939 - This driver adds 4 i2c buses
1941 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1942 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1943 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1944 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1945 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1946 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1947 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1948 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1949 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1951 - drivers/i2c/sh_i2c.c:
1952 - activate this driver with CONFIG_SYS_I2C_SH
1953 - This driver adds from 2 to 5 i2c buses
1955 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1956 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1957 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1958 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1959 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1960 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1961 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1962 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1963 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1964 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1965 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1967 - drivers/i2c/omap24xx_i2c.c
1968 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1969 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1970 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1971 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1972 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1973 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1974 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1975 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1976 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1977 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1978 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1980 - drivers/i2c/zynq_i2c.c
1981 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1982 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1983 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1985 - drivers/i2c/s3c24x0_i2c.c:
1986 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1987 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1988 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1989 with a fix speed from 100000 and the slave addr 0!
1991 - drivers/i2c/ihs_i2c.c
1992 - activate this driver with CONFIG_SYS_I2C_IHS
1993 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1994 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1995 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1996 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1997 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1998 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1999 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2000 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2001 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2002 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2003 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2004 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2005 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2006 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2007 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2008 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2009 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2010 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2011 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2012 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2013 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2017 CONFIG_SYS_NUM_I2C_BUSES
2018 Hold the number of i2c buses you want to use.
2020 CONFIG_SYS_I2C_DIRECT_BUS
2021 define this, if you don't use i2c muxes on your hardware.
2022 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2025 CONFIG_SYS_I2C_MAX_HOPS
2026 define how many muxes are maximal consecutively connected
2027 on one i2c bus. If you not use i2c muxes, omit this
2030 CONFIG_SYS_I2C_BUSES
2031 hold a list of buses you want to use, only used if
2032 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2033 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2034 CONFIG_SYS_NUM_I2C_BUSES = 9:
2036 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2037 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2038 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2039 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2040 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2041 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2042 {1, {I2C_NULL_HOP}}, \
2043 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2044 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2048 bus 0 on adapter 0 without a mux
2049 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2050 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2051 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2052 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2053 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2054 bus 6 on adapter 1 without a mux
2055 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2056 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2058 If you do not have i2c muxes on your board, omit this define.
2060 - Legacy I2C Support:
2061 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2062 then the following macros need to be defined (examples are
2063 from include/configs/lwmon.h):
2067 (Optional). Any commands necessary to enable the I2C
2068 controller or configure ports.
2070 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2074 The code necessary to make the I2C data line active
2075 (driven). If the data line is open collector, this
2078 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2082 The code necessary to make the I2C data line tri-stated
2083 (inactive). If the data line is open collector, this
2086 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2090 Code that returns true if the I2C data line is high,
2093 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2097 If <bit> is true, sets the I2C data line high. If it
2098 is false, it clears it (low).
2100 eg: #define I2C_SDA(bit) \
2101 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2102 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2106 If <bit> is true, sets the I2C clock line high. If it
2107 is false, it clears it (low).
2109 eg: #define I2C_SCL(bit) \
2110 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2111 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2115 This delay is invoked four times per clock cycle so this
2116 controls the rate of data transfer. The data rate thus
2117 is 1 / (I2C_DELAY * 4). Often defined to be something
2120 #define I2C_DELAY udelay(2)
2122 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2124 If your arch supports the generic GPIO framework (asm/gpio.h),
2125 then you may alternatively define the two GPIOs that are to be
2126 used as SCL / SDA. Any of the previous I2C_xxx macros will
2127 have GPIO-based defaults assigned to them as appropriate.
2129 You should define these to the GPIO value as given directly to
2130 the generic GPIO functions.
2132 CONFIG_SYS_I2C_INIT_BOARD
2134 When a board is reset during an i2c bus transfer
2135 chips might think that the current transfer is still
2136 in progress. On some boards it is possible to access
2137 the i2c SCLK line directly, either by using the
2138 processor pin as a GPIO or by having a second pin
2139 connected to the bus. If this option is defined a
2140 custom i2c_init_board() routine in boards/xxx/board.c
2141 is run early in the boot sequence.
2143 CONFIG_I2C_MULTI_BUS
2145 This option allows the use of multiple I2C buses, each of which
2146 must have a controller. At any point in time, only one bus is
2147 active. To switch to a different bus, use the 'i2c dev' command.
2148 Note that bus numbering is zero-based.
2150 CONFIG_SYS_I2C_NOPROBES
2152 This option specifies a list of I2C devices that will be skipped
2153 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2154 is set, specify a list of bus-device pairs. Otherwise, specify
2155 a 1D array of device addresses
2158 #undef CONFIG_I2C_MULTI_BUS
2159 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2161 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2163 #define CONFIG_I2C_MULTI_BUS
2164 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2166 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2168 CONFIG_SYS_SPD_BUS_NUM
2170 If defined, then this indicates the I2C bus number for DDR SPD.
2171 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2173 CONFIG_SYS_RTC_BUS_NUM
2175 If defined, then this indicates the I2C bus number for the RTC.
2176 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2178 CONFIG_SOFT_I2C_READ_REPEATED_START
2180 defining this will force the i2c_read() function in
2181 the soft_i2c driver to perform an I2C repeated start
2182 between writing the address pointer and reading the
2183 data. If this define is omitted the default behaviour
2184 of doing a stop-start sequence will be used. Most I2C
2185 devices can use either method, but some require one or
2188 - SPI Support: CONFIG_SPI
2190 Enables SPI driver (so far only tested with
2191 SPI EEPROM, also an instance works with Crystal A/D and
2192 D/As on the SACSng board)
2196 Enables the driver for SPI controller on SuperH. Currently
2197 only SH7757 is supported.
2201 Enables a software (bit-bang) SPI driver rather than
2202 using hardware support. This is a general purpose
2203 driver that only requires three general I/O port pins
2204 (two outputs, one input) to function. If this is
2205 defined, the board configuration must define several
2206 SPI configuration items (port pins to use, etc). For
2207 an example, see include/configs/sacsng.h.
2211 Enables a hardware SPI driver for general-purpose reads
2212 and writes. As with CONFIG_SOFT_SPI, the board configuration
2213 must define a list of chip-select function pointers.
2214 Currently supported on some MPC8xxx processors. For an
2215 example, see include/configs/mpc8349emds.h.
2219 Enables the driver for the SPI controllers on i.MX and MXC
2220 SoCs. Currently i.MX31/35/51 are supported.
2222 CONFIG_SYS_SPI_MXC_WAIT
2223 Timeout for waiting until spi transfer completed.
2224 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2226 - FPGA Support: CONFIG_FPGA
2228 Enables FPGA subsystem.
2230 CONFIG_FPGA_<vendor>
2232 Enables support for specific chip vendors.
2235 CONFIG_FPGA_<family>
2237 Enables support for FPGA family.
2238 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2242 Specify the number of FPGA devices to support.
2244 CONFIG_SYS_FPGA_PROG_FEEDBACK
2246 Enable printing of hash marks during FPGA configuration.
2248 CONFIG_SYS_FPGA_CHECK_BUSY
2250 Enable checks on FPGA configuration interface busy
2251 status by the configuration function. This option
2252 will require a board or device specific function to
2257 If defined, a function that provides delays in the FPGA
2258 configuration driver.
2260 CONFIG_SYS_FPGA_CHECK_CTRLC
2261 Allow Control-C to interrupt FPGA configuration
2263 CONFIG_SYS_FPGA_CHECK_ERROR
2265 Check for configuration errors during FPGA bitfile
2266 loading. For example, abort during Virtex II
2267 configuration if the INIT_B line goes low (which
2268 indicated a CRC error).
2270 CONFIG_SYS_FPGA_WAIT_INIT
2272 Maximum time to wait for the INIT_B line to de-assert
2273 after PROB_B has been de-asserted during a Virtex II
2274 FPGA configuration sequence. The default time is 500
2277 CONFIG_SYS_FPGA_WAIT_BUSY
2279 Maximum time to wait for BUSY to de-assert during
2280 Virtex II FPGA configuration. The default is 5 ms.
2282 CONFIG_SYS_FPGA_WAIT_CONFIG
2284 Time to wait after FPGA configuration. The default is
2287 - Configuration Management:
2290 Some SoCs need special image types (e.g. U-Boot binary
2291 with a special header) as build targets. By defining
2292 CONFIG_BUILD_TARGET in the SoC / board header, this
2293 special image will be automatically built upon calling
2298 If defined, this string will be added to the U-Boot
2299 version information (U_BOOT_VERSION)
2301 - Vendor Parameter Protection:
2303 U-Boot considers the values of the environment
2304 variables "serial#" (Board Serial Number) and
2305 "ethaddr" (Ethernet Address) to be parameters that
2306 are set once by the board vendor / manufacturer, and
2307 protects these variables from casual modification by
2308 the user. Once set, these variables are read-only,
2309 and write or delete attempts are rejected. You can
2310 change this behaviour:
2312 If CONFIG_ENV_OVERWRITE is #defined in your config
2313 file, the write protection for vendor parameters is
2314 completely disabled. Anybody can change or delete
2317 Alternatively, if you define _both_ an ethaddr in the
2318 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2319 Ethernet address is installed in the environment,
2320 which can be changed exactly ONCE by the user. [The
2321 serial# is unaffected by this, i. e. it remains
2324 The same can be accomplished in a more flexible way
2325 for any variable by configuring the type of access
2326 to allow for those variables in the ".flags" variable
2327 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2332 Define this variable to enable the reservation of
2333 "protected RAM", i. e. RAM which is not overwritten
2334 by U-Boot. Define CONFIG_PRAM to hold the number of
2335 kB you want to reserve for pRAM. You can overwrite
2336 this default value by defining an environment
2337 variable "pram" to the number of kB you want to
2338 reserve. Note that the board info structure will
2339 still show the full amount of RAM. If pRAM is
2340 reserved, a new environment variable "mem" will
2341 automatically be defined to hold the amount of
2342 remaining RAM in a form that can be passed as boot
2343 argument to Linux, for instance like that:
2345 setenv bootargs ... mem=\${mem}
2348 This way you can tell Linux not to use this memory,
2349 either, which results in a memory region that will
2350 not be affected by reboots.
2352 *WARNING* If your board configuration uses automatic
2353 detection of the RAM size, you must make sure that
2354 this memory test is non-destructive. So far, the
2355 following board configurations are known to be
2358 IVMS8, IVML24, SPD8xx,
2359 HERMES, IP860, RPXlite, LWMON,
2362 - Access to physical memory region (> 4GB)
2363 Some basic support is provided for operations on memory not
2364 normally accessible to U-Boot - e.g. some architectures
2365 support access to more than 4GB of memory on 32-bit
2366 machines using physical address extension or similar.
2367 Define CONFIG_PHYSMEM to access this basic support, which
2368 currently only supports clearing the memory.
2373 Define this variable to stop the system in case of a
2374 fatal error, so that you have to reset it manually.
2375 This is probably NOT a good idea for an embedded
2376 system where you want the system to reboot
2377 automatically as fast as possible, but it may be
2378 useful during development since you can try to debug
2379 the conditions that lead to the situation.
2381 CONFIG_NET_RETRY_COUNT
2383 This variable defines the number of retries for
2384 network operations like ARP, RARP, TFTP, or BOOTP
2385 before giving up the operation. If not defined, a
2386 default value of 5 is used.
2390 Timeout waiting for an ARP reply in milliseconds.
2394 Timeout in milliseconds used in NFS protocol.
2395 If you encounter "ERROR: Cannot umount" in nfs command,
2396 try longer timeout such as
2397 #define CONFIG_NFS_TIMEOUT 10000UL
2399 - Command Interpreter:
2400 CONFIG_AUTO_COMPLETE
2402 Enable auto completion of commands using TAB.
2404 CONFIG_SYS_PROMPT_HUSH_PS2
2406 This defines the secondary prompt string, which is
2407 printed when the command interpreter needs more input
2408 to complete a command. Usually "> ".
2412 In the current implementation, the local variables
2413 space and global environment variables space are
2414 separated. Local variables are those you define by
2415 simply typing `name=value'. To access a local
2416 variable later on, you have write `$name' or
2417 `${name}'; to execute the contents of a variable
2418 directly type `$name' at the command prompt.
2420 Global environment variables are those you use
2421 setenv/printenv to work with. To run a command stored
2422 in such a variable, you need to use the run command,
2423 and you must not use the '$' sign to access them.
2425 To store commands and special characters in a
2426 variable, please use double quotation marks
2427 surrounding the whole text of the variable, instead
2428 of the backslashes before semicolons and special
2431 - Command Line Editing and History:
2432 CONFIG_CMDLINE_EDITING
2434 Enable editing and History functions for interactive
2435 command line input operations
2437 - Command Line PS1/PS2 support:
2438 CONFIG_CMDLINE_PS_SUPPORT
2440 Enable support for changing the command prompt string
2441 at run-time. Only static string is supported so far.
2442 The string is obtained from environment variables PS1
2445 - Default Environment:
2446 CONFIG_EXTRA_ENV_SETTINGS
2448 Define this to contain any number of null terminated
2449 strings (variable = value pairs) that will be part of
2450 the default environment compiled into the boot image.
2452 For example, place something like this in your
2453 board's config file:
2455 #define CONFIG_EXTRA_ENV_SETTINGS \
2459 Warning: This method is based on knowledge about the
2460 internal format how the environment is stored by the
2461 U-Boot code. This is NOT an official, exported
2462 interface! Although it is unlikely that this format
2463 will change soon, there is no guarantee either.
2464 You better know what you are doing here.
2466 Note: overly (ab)use of the default environment is
2467 discouraged. Make sure to check other ways to preset
2468 the environment like the "source" command or the
2471 CONFIG_ENV_VARS_UBOOT_CONFIG
2473 Define this in order to add variables describing the
2474 U-Boot build configuration to the default environment.
2475 These will be named arch, cpu, board, vendor, and soc.
2477 Enabling this option will cause the following to be defined:
2485 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2487 Define this in order to add variables describing certain
2488 run-time determined information about the hardware to the
2489 environment. These will be named board_name, board_rev.
2491 CONFIG_DELAY_ENVIRONMENT
2493 Normally the environment is loaded when the board is
2494 initialised so that it is available to U-Boot. This inhibits
2495 that so that the environment is not available until
2496 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2497 this is instead controlled by the value of
2498 /config/load-environment.
2500 - DataFlash Support:
2501 CONFIG_HAS_DATAFLASH
2503 Defining this option enables DataFlash features and
2504 allows to read/write in Dataflash via the standard
2507 - Serial Flash support
2510 Defining this option enables SPI flash commands
2511 'sf probe/read/write/erase/update'.
2513 Usage requires an initial 'probe' to define the serial
2514 flash parameters, followed by read/write/erase/update
2517 The following defaults may be provided by the platform
2518 to handle the common case when only a single serial
2519 flash is present on the system.
2521 CONFIG_SF_DEFAULT_BUS Bus identifier
2522 CONFIG_SF_DEFAULT_CS Chip-select
2523 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2524 CONFIG_SF_DEFAULT_SPEED in Hz
2528 Define this option to include a destructive SPI flash
2531 - SystemACE Support:
2534 Adding this option adds support for Xilinx SystemACE
2535 chips attached via some sort of local bus. The address
2536 of the chip must also be defined in the
2537 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2539 #define CONFIG_SYSTEMACE
2540 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2542 When SystemACE support is added, the "ace" device type
2543 becomes available to the fat commands, i.e. fatls.
2545 - TFTP Fixed UDP Port:
2548 If this is defined, the environment variable tftpsrcp
2549 is used to supply the TFTP UDP source port value.
2550 If tftpsrcp isn't defined, the normal pseudo-random port
2551 number generator is used.
2553 Also, the environment variable tftpdstp is used to supply
2554 the TFTP UDP destination port value. If tftpdstp isn't
2555 defined, the normal port 69 is used.
2557 The purpose for tftpsrcp is to allow a TFTP server to
2558 blindly start the TFTP transfer using the pre-configured
2559 target IP address and UDP port. This has the effect of
2560 "punching through" the (Windows XP) firewall, allowing
2561 the remainder of the TFTP transfer to proceed normally.
2562 A better solution is to properly configure the firewall,
2563 but sometimes that is not allowed.
2565 - bootcount support:
2566 CONFIG_BOOTCOUNT_LIMIT
2568 This enables the bootcounter support, see:
2569 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2572 enable special bootcounter support on at91sam9xe based boards.
2574 enable special bootcounter support on da850 based boards.
2575 CONFIG_BOOTCOUNT_RAM
2576 enable support for the bootcounter in RAM
2577 CONFIG_BOOTCOUNT_I2C
2578 enable support for the bootcounter on an i2c (like RTC) device.
2579 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2580 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2582 CONFIG_BOOTCOUNT_ALEN = address len
2584 - Show boot progress:
2585 CONFIG_SHOW_BOOT_PROGRESS
2587 Defining this option allows to add some board-
2588 specific code (calling a user-provided function
2589 "show_boot_progress(int)") that enables you to show
2590 the system's boot progress on some display (for
2591 example, some LED's) on your board. At the moment,
2592 the following checkpoints are implemented:
2595 Legacy uImage format:
2598 1 common/cmd_bootm.c before attempting to boot an image
2599 -1 common/cmd_bootm.c Image header has bad magic number
2600 2 common/cmd_bootm.c Image header has correct magic number
2601 -2 common/cmd_bootm.c Image header has bad checksum
2602 3 common/cmd_bootm.c Image header has correct checksum
2603 -3 common/cmd_bootm.c Image data has bad checksum
2604 4 common/cmd_bootm.c Image data has correct checksum
2605 -4 common/cmd_bootm.c Image is for unsupported architecture
2606 5 common/cmd_bootm.c Architecture check OK
2607 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2608 6 common/cmd_bootm.c Image Type check OK
2609 -6 common/cmd_bootm.c gunzip uncompression error
2610 -7 common/cmd_bootm.c Unimplemented compression type
2611 7 common/cmd_bootm.c Uncompression OK
2612 8 common/cmd_bootm.c No uncompress/copy overwrite error
2613 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2615 9 common/image.c Start initial ramdisk verification
2616 -10 common/image.c Ramdisk header has bad magic number
2617 -11 common/image.c Ramdisk header has bad checksum
2618 10 common/image.c Ramdisk header is OK
2619 -12 common/image.c Ramdisk data has bad checksum
2620 11 common/image.c Ramdisk data has correct checksum
2621 12 common/image.c Ramdisk verification complete, start loading
2622 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2623 13 common/image.c Start multifile image verification
2624 14 common/image.c No initial ramdisk, no multifile, continue.
2626 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2628 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2629 -31 post/post.c POST test failed, detected by post_output_backlog()
2630 -32 post/post.c POST test failed, detected by post_run_single()
2632 34 common/cmd_doc.c before loading a Image from a DOC device
2633 -35 common/cmd_doc.c Bad usage of "doc" command
2634 35 common/cmd_doc.c correct usage of "doc" command
2635 -36 common/cmd_doc.c No boot device
2636 36 common/cmd_doc.c correct boot device
2637 -37 common/cmd_doc.c Unknown Chip ID on boot device
2638 37 common/cmd_doc.c correct chip ID found, device available
2639 -38 common/cmd_doc.c Read Error on boot device
2640 38 common/cmd_doc.c reading Image header from DOC device OK
2641 -39 common/cmd_doc.c Image header has bad magic number
2642 39 common/cmd_doc.c Image header has correct magic number
2643 -40 common/cmd_doc.c Error reading Image from DOC device
2644 40 common/cmd_doc.c Image header has correct magic number
2645 41 common/cmd_ide.c before loading a Image from a IDE device
2646 -42 common/cmd_ide.c Bad usage of "ide" command
2647 42 common/cmd_ide.c correct usage of "ide" command
2648 -43 common/cmd_ide.c No boot device
2649 43 common/cmd_ide.c boot device found
2650 -44 common/cmd_ide.c Device not available
2651 44 common/cmd_ide.c Device available
2652 -45 common/cmd_ide.c wrong partition selected
2653 45 common/cmd_ide.c partition selected
2654 -46 common/cmd_ide.c Unknown partition table
2655 46 common/cmd_ide.c valid partition table found
2656 -47 common/cmd_ide.c Invalid partition type
2657 47 common/cmd_ide.c correct partition type
2658 -48 common/cmd_ide.c Error reading Image Header on boot device
2659 48 common/cmd_ide.c reading Image Header from IDE device OK
2660 -49 common/cmd_ide.c Image header has bad magic number
2661 49 common/cmd_ide.c Image header has correct magic number
2662 -50 common/cmd_ide.c Image header has bad checksum
2663 50 common/cmd_ide.c Image header has correct checksum
2664 -51 common/cmd_ide.c Error reading Image from IDE device
2665 51 common/cmd_ide.c reading Image from IDE device OK
2666 52 common/cmd_nand.c before loading a Image from a NAND device
2667 -53 common/cmd_nand.c Bad usage of "nand" command
2668 53 common/cmd_nand.c correct usage of "nand" command
2669 -54 common/cmd_nand.c No boot device
2670 54 common/cmd_nand.c boot device found
2671 -55 common/cmd_nand.c Unknown Chip ID on boot device
2672 55 common/cmd_nand.c correct chip ID found, device available
2673 -56 common/cmd_nand.c Error reading Image Header on boot device
2674 56 common/cmd_nand.c reading Image Header from NAND device OK
2675 -57 common/cmd_nand.c Image header has bad magic number
2676 57 common/cmd_nand.c Image header has correct magic number
2677 -58 common/cmd_nand.c Error reading Image from NAND device
2678 58 common/cmd_nand.c reading Image from NAND device OK
2680 -60 common/env_common.c Environment has a bad CRC, using default
2682 64 net/eth.c starting with Ethernet configuration.
2683 -64 net/eth.c no Ethernet found.
2684 65 net/eth.c Ethernet found.
2686 -80 common/cmd_net.c usage wrong
2687 80 common/cmd_net.c before calling net_loop()
2688 -81 common/cmd_net.c some error in net_loop() occurred
2689 81 common/cmd_net.c net_loop() back without error
2690 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2691 82 common/cmd_net.c trying automatic boot
2692 83 common/cmd_net.c running "source" command
2693 -83 common/cmd_net.c some error in automatic boot or "source" command
2694 84 common/cmd_net.c end without errors
2699 100 common/cmd_bootm.c Kernel FIT Image has correct format
2700 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2701 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2702 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2703 102 common/cmd_bootm.c Kernel unit name specified
2704 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2705 103 common/cmd_bootm.c Found configuration node
2706 104 common/cmd_bootm.c Got kernel subimage node offset
2707 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2708 105 common/cmd_bootm.c Kernel subimage hash verification OK
2709 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2710 106 common/cmd_bootm.c Architecture check OK
2711 -106 common/cmd_bootm.c Kernel subimage has wrong type
2712 107 common/cmd_bootm.c Kernel subimage type OK
2713 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2714 108 common/cmd_bootm.c Got kernel subimage data/size
2715 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2716 -109 common/cmd_bootm.c Can't get kernel subimage type
2717 -110 common/cmd_bootm.c Can't get kernel subimage comp
2718 -111 common/cmd_bootm.c Can't get kernel subimage os
2719 -112 common/cmd_bootm.c Can't get kernel subimage load address
2720 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2722 120 common/image.c Start initial ramdisk verification
2723 -120 common/image.c Ramdisk FIT image has incorrect format
2724 121 common/image.c Ramdisk FIT image has correct format
2725 122 common/image.c No ramdisk subimage unit name, using configuration
2726 -122 common/image.c Can't get configuration for ramdisk subimage
2727 123 common/image.c Ramdisk unit name specified
2728 -124 common/image.c Can't get ramdisk subimage node offset
2729 125 common/image.c Got ramdisk subimage node offset
2730 -125 common/image.c Ramdisk subimage hash verification failed
2731 126 common/image.c Ramdisk subimage hash verification OK
2732 -126 common/image.c Ramdisk subimage for unsupported architecture
2733 127 common/image.c Architecture check OK
2734 -127 common/image.c Can't get ramdisk subimage data/size
2735 128 common/image.c Got ramdisk subimage data/size
2736 129 common/image.c Can't get ramdisk load address
2737 -129 common/image.c Got ramdisk load address
2739 -130 common/cmd_doc.c Incorrect FIT image format
2740 131 common/cmd_doc.c FIT image format OK
2742 -140 common/cmd_ide.c Incorrect FIT image format
2743 141 common/cmd_ide.c FIT image format OK
2745 -150 common/cmd_nand.c Incorrect FIT image format
2746 151 common/cmd_nand.c FIT image format OK
2748 - legacy image format:
2749 CONFIG_IMAGE_FORMAT_LEGACY
2750 enables the legacy image format support in U-Boot.
2753 enabled if CONFIG_FIT_SIGNATURE is not defined.
2755 CONFIG_DISABLE_IMAGE_LEGACY
2756 disable the legacy image format
2758 This define is introduced, as the legacy image format is
2759 enabled per default for backward compatibility.
2761 - Standalone program support:
2762 CONFIG_STANDALONE_LOAD_ADDR
2764 This option defines a board specific value for the
2765 address where standalone program gets loaded, thus
2766 overwriting the architecture dependent default
2769 - Frame Buffer Address:
2772 Define CONFIG_FB_ADDR if you want to use specific
2773 address for frame buffer. This is typically the case
2774 when using a graphics controller has separate video
2775 memory. U-Boot will then place the frame buffer at
2776 the given address instead of dynamically reserving it
2777 in system RAM by calling lcd_setmem(), which grabs
2778 the memory for the frame buffer depending on the
2779 configured panel size.
2781 Please see board_init_f function.
2783 - Automatic software updates via TFTP server
2785 CONFIG_UPDATE_TFTP_CNT_MAX
2786 CONFIG_UPDATE_TFTP_MSEC_MAX
2788 These options enable and control the auto-update feature;
2789 for a more detailed description refer to doc/README.update.
2791 - MTD Support (mtdparts command, UBI support)
2794 Adds the MTD device infrastructure from the Linux kernel.
2795 Needed for mtdparts command support.
2797 CONFIG_MTD_PARTITIONS
2799 Adds the MTD partitioning infrastructure from the Linux
2800 kernel. Needed for UBI support.
2805 Adds commands for interacting with MTD partitions formatted
2806 with the UBI flash translation layer
2808 Requires also defining CONFIG_RBTREE
2810 CONFIG_UBI_SILENCE_MSG
2812 Make the verbose messages from UBI stop printing. This leaves
2813 warnings and errors enabled.
2816 CONFIG_MTD_UBI_WL_THRESHOLD
2817 This parameter defines the maximum difference between the highest
2818 erase counter value and the lowest erase counter value of eraseblocks
2819 of UBI devices. When this threshold is exceeded, UBI starts performing
2820 wear leveling by means of moving data from eraseblock with low erase
2821 counter to eraseblocks with high erase counter.
2823 The default value should be OK for SLC NAND flashes, NOR flashes and
2824 other flashes which have eraseblock life-cycle 100000 or more.
2825 However, in case of MLC NAND flashes which typically have eraseblock
2826 life-cycle less than 10000, the threshold should be lessened (e.g.,
2827 to 128 or 256, although it does not have to be power of 2).
2831 CONFIG_MTD_UBI_BEB_LIMIT
2832 This option specifies the maximum bad physical eraseblocks UBI
2833 expects on the MTD device (per 1024 eraseblocks). If the
2834 underlying flash does not admit of bad eraseblocks (e.g. NOR
2835 flash), this value is ignored.
2837 NAND datasheets often specify the minimum and maximum NVM
2838 (Number of Valid Blocks) for the flashes' endurance lifetime.
2839 The maximum expected bad eraseblocks per 1024 eraseblocks
2840 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2841 which gives 20 for most NANDs (MaxNVB is basically the total
2842 count of eraseblocks on the chip).
2844 To put it differently, if this value is 20, UBI will try to
2845 reserve about 1.9% of physical eraseblocks for bad blocks
2846 handling. And that will be 1.9% of eraseblocks on the entire
2847 NAND chip, not just the MTD partition UBI attaches. This means
2848 that if you have, say, a NAND flash chip admits maximum 40 bad
2849 eraseblocks, and it is split on two MTD partitions of the same
2850 size, UBI will reserve 40 eraseblocks when attaching a
2855 CONFIG_MTD_UBI_FASTMAP
2856 Fastmap is a mechanism which allows attaching an UBI device
2857 in nearly constant time. Instead of scanning the whole MTD device it
2858 only has to locate a checkpoint (called fastmap) on the device.
2859 The on-flash fastmap contains all information needed to attach
2860 the device. Using fastmap makes only sense on large devices where
2861 attaching by scanning takes long. UBI will not automatically install
2862 a fastmap on old images, but you can set the UBI parameter
2863 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2864 that fastmap-enabled images are still usable with UBI implementations
2865 without fastmap support. On typical flash devices the whole fastmap
2866 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2868 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2869 Set this parameter to enable fastmap automatically on images
2873 CONFIG_MTD_UBI_FM_DEBUG
2874 Enable UBI fastmap debug
2880 Adds commands for interacting with UBI volumes formatted as
2881 UBIFS. UBIFS is read-only in u-boot.
2883 Requires UBI support as well as CONFIG_LZO
2885 CONFIG_UBIFS_SILENCE_MSG
2887 Make the verbose messages from UBIFS stop printing. This leaves
2888 warnings and errors enabled.
2892 Enable building of SPL globally.
2895 LDSCRIPT for linking the SPL binary.
2897 CONFIG_SPL_MAX_FOOTPRINT
2898 Maximum size in memory allocated to the SPL, BSS included.
2899 When defined, the linker checks that the actual memory
2900 used by SPL from _start to __bss_end does not exceed it.
2901 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2902 must not be both defined at the same time.
2905 Maximum size of the SPL image (text, data, rodata, and
2906 linker lists sections), BSS excluded.
2907 When defined, the linker checks that the actual size does
2910 CONFIG_SPL_TEXT_BASE
2911 TEXT_BASE for linking the SPL binary.
2913 CONFIG_SPL_RELOC_TEXT_BASE
2914 Address to relocate to. If unspecified, this is equal to
2915 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2917 CONFIG_SPL_BSS_START_ADDR
2918 Link address for the BSS within the SPL binary.
2920 CONFIG_SPL_BSS_MAX_SIZE
2921 Maximum size in memory allocated to the SPL BSS.
2922 When defined, the linker checks that the actual memory used
2923 by SPL from __bss_start to __bss_end does not exceed it.
2924 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2925 must not be both defined at the same time.
2928 Adress of the start of the stack SPL will use
2930 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2931 When defined, SPL will panic() if the image it has
2932 loaded does not have a signature.
2933 Defining this is useful when code which loads images
2934 in SPL cannot guarantee that absolutely all read errors
2936 An example is the LPC32XX MLC NAND driver, which will
2937 consider that a completely unreadable NAND block is bad,
2938 and thus should be skipped silently.
2940 CONFIG_SPL_RELOC_STACK
2941 Adress of the start of the stack SPL will use after
2942 relocation. If unspecified, this is equal to
2945 CONFIG_SYS_SPL_MALLOC_START
2946 Starting address of the malloc pool used in SPL.
2947 When this option is set the full malloc is used in SPL and
2948 it is set up by spl_init() and before that, the simple malloc()
2949 can be used if CONFIG_SYS_MALLOC_F is defined.
2951 CONFIG_SYS_SPL_MALLOC_SIZE
2952 The size of the malloc pool used in SPL.
2954 CONFIG_SPL_FRAMEWORK
2955 Enable the SPL framework under common/. This framework
2956 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2957 NAND loading of the Linux Kernel.
2960 Enable booting directly to an OS from SPL.
2961 See also: doc/README.falcon
2963 CONFIG_SPL_DISPLAY_PRINT
2964 For ARM, enable an optional function to print more information
2965 about the running system.
2967 CONFIG_SPL_INIT_MINIMAL
2968 Arch init code should be built for a very small image
2970 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2971 Partition on the MMC to load U-Boot from when the MMC is being
2974 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2975 Sector to load kernel uImage from when MMC is being
2976 used in raw mode (for Falcon mode)
2978 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2979 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2980 Sector and number of sectors to load kernel argument
2981 parameters from when MMC is being used in raw mode
2984 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2985 Partition on the MMC to load U-Boot from when the MMC is being
2988 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2989 Filename to read to load U-Boot when reading from filesystem
2991 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2992 Filename to read to load kernel uImage when reading
2993 from filesystem (for Falcon mode)
2995 CONFIG_SPL_FS_LOAD_ARGS_NAME
2996 Filename to read to load kernel argument parameters
2997 when reading from filesystem (for Falcon mode)
2999 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3000 Set this for NAND SPL on PPC mpc83xx targets, so that
3001 start.S waits for the rest of the SPL to load before
3002 continuing (the hardware starts execution after just
3003 loading the first page rather than the full 4K).
3005 CONFIG_SPL_SKIP_RELOCATE
3006 Avoid SPL relocation
3008 CONFIG_SPL_NAND_BASE
3009 Include nand_base.c in the SPL. Requires
3010 CONFIG_SPL_NAND_DRIVERS.
3012 CONFIG_SPL_NAND_DRIVERS
3013 SPL uses normal NAND drivers, not minimal drivers.
3016 Include standard software ECC in the SPL
3018 CONFIG_SPL_NAND_SIMPLE
3019 Support for NAND boot using simple NAND drivers that
3020 expose the cmd_ctrl() interface.
3023 Support for a lightweight UBI (fastmap) scanner and
3026 CONFIG_SPL_NAND_RAW_ONLY
3027 Support to boot only raw u-boot.bin images. Use this only
3028 if you need to save space.
3030 CONFIG_SPL_COMMON_INIT_DDR
3031 Set for common ddr init with serial presence detect in
3034 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3035 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3036 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3037 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3038 CONFIG_SYS_NAND_ECCBYTES
3039 Defines the size and behavior of the NAND that SPL uses
3042 CONFIG_SPL_NAND_BOOT
3043 Add support NAND boot
3045 CONFIG_SYS_NAND_U_BOOT_OFFS
3046 Location in NAND to read U-Boot from
3048 CONFIG_SYS_NAND_U_BOOT_DST
3049 Location in memory to load U-Boot to
3051 CONFIG_SYS_NAND_U_BOOT_SIZE
3052 Size of image to load
3054 CONFIG_SYS_NAND_U_BOOT_START
3055 Entry point in loaded image to jump to
3057 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3058 Define this if you need to first read the OOB and then the
3059 data. This is used, for example, on davinci platforms.
3061 CONFIG_SPL_OMAP3_ID_NAND
3062 Support for an OMAP3-specific set of functions to return the
3063 ID and MFR of the first attached NAND chip, if present.
3065 CONFIG_SPL_RAM_DEVICE
3066 Support for running image already present in ram, in SPL binary
3069 Image offset to which the SPL should be padded before appending
3070 the SPL payload. By default, this is defined as
3071 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3072 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3073 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3076 Final target image containing SPL and payload. Some SPLs
3077 use an arch-specific makefile fragment instead, for
3078 example if more than one image needs to be produced.
3080 CONFIG_FIT_SPL_PRINT
3081 Printing information about a FIT image adds quite a bit of
3082 code to SPL. So this is normally disabled in SPL. Use this
3083 option to re-enable it. This will affect the output of the
3084 bootm command when booting a FIT image.
3088 Enable building of TPL globally.
3091 Image offset to which the TPL should be padded before appending
3092 the TPL payload. By default, this is defined as
3093 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3094 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3095 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3097 - Interrupt support (PPC):
3099 There are common interrupt_init() and timer_interrupt()
3100 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3101 for CPU specific initialization. interrupt_init_cpu()
3102 should set decrementer_count to appropriate value. If
3103 CPU resets decrementer automatically after interrupt
3104 (ppc4xx) it should set decrementer_count to zero.
3105 timer_interrupt() calls timer_interrupt_cpu() for CPU
3106 specific handling. If board has watchdog / status_led
3107 / other_activity_monitor it works automatically from
3108 general timer_interrupt().
3111 Board initialization settings:
3112 ------------------------------
3114 During Initialization u-boot calls a number of board specific functions
3115 to allow the preparation of board specific prerequisites, e.g. pin setup
3116 before drivers are initialized. To enable these callbacks the
3117 following configuration macros have to be defined. Currently this is
3118 architecture specific, so please check arch/your_architecture/lib/board.c
3119 typically in board_init_f() and board_init_r().
3121 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3122 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3123 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3124 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3126 Configuration Settings:
3127 -----------------------
3129 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3130 Optionally it can be defined to support 64-bit memory commands.
3132 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3133 undefine this when you're short of memory.
3135 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3136 width of the commands listed in the 'help' command output.
3138 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3139 prompt for user input.
3141 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3143 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3145 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3147 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3148 the application (usually a Linux kernel) when it is
3151 - CONFIG_SYS_BAUDRATE_TABLE:
3152 List of legal baudrate settings for this board.
3154 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3155 Begin and End addresses of the area used by the
3158 - CONFIG_SYS_ALT_MEMTEST:
3159 Enable an alternate, more extensive memory test.
3161 - CONFIG_SYS_MEMTEST_SCRATCH:
3162 Scratch address used by the alternate memory test
3163 You only need to set this if address zero isn't writeable
3165 - CONFIG_SYS_MEM_RESERVE_SECURE
3166 Only implemented for ARMv8 for now.
3167 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3168 is substracted from total RAM and won't be reported to OS.
3169 This memory can be used as secure memory. A variable
3170 gd->arch.secure_ram is used to track the location. In systems
3171 the RAM base is not zero, or RAM is divided into banks,
3172 this variable needs to be recalcuated to get the address.
3174 - CONFIG_SYS_MEM_TOP_HIDE:
3175 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3176 this specified memory area will get subtracted from the top
3177 (end) of RAM and won't get "touched" at all by U-Boot. By
3178 fixing up gd->ram_size the Linux kernel should gets passed
3179 the now "corrected" memory size and won't touch it either.
3180 This should work for arch/ppc and arch/powerpc. Only Linux
3181 board ports in arch/powerpc with bootwrapper support that
3182 recalculate the memory size from the SDRAM controller setup
3183 will have to get fixed in Linux additionally.
3185 This option can be used as a workaround for the 440EPx/GRx
3186 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3189 WARNING: Please make sure that this value is a multiple of
3190 the Linux page size (normally 4k). If this is not the case,
3191 then the end address of the Linux memory will be located at a
3192 non page size aligned address and this could cause major
3195 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3196 Enable temporary baudrate change while serial download
3198 - CONFIG_SYS_SDRAM_BASE:
3199 Physical start address of SDRAM. _Must_ be 0 here.
3201 - CONFIG_SYS_FLASH_BASE:
3202 Physical start address of Flash memory.
3204 - CONFIG_SYS_MONITOR_BASE:
3205 Physical start address of boot monitor code (set by
3206 make config files to be same as the text base address
3207 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3208 CONFIG_SYS_FLASH_BASE when booting from flash.
3210 - CONFIG_SYS_MONITOR_LEN:
3211 Size of memory reserved for monitor code, used to
3212 determine _at_compile_time_ (!) if the environment is
3213 embedded within the U-Boot image, or in a separate
3216 - CONFIG_SYS_MALLOC_LEN:
3217 Size of DRAM reserved for malloc() use.
3219 - CONFIG_SYS_MALLOC_F_LEN
3220 Size of the malloc() pool for use before relocation. If
3221 this is defined, then a very simple malloc() implementation
3222 will become available before relocation. The address is just
3223 below the global data, and the stack is moved down to make
3226 This feature allocates regions with increasing addresses
3227 within the region. calloc() is supported, but realloc()
3228 is not available. free() is supported but does nothing.
3229 The memory will be freed (or in fact just forgotten) when
3230 U-Boot relocates itself.
3232 - CONFIG_SYS_MALLOC_SIMPLE
3233 Provides a simple and small malloc() and calloc() for those
3234 boards which do not use the full malloc in SPL (which is
3235 enabled with CONFIG_SYS_SPL_MALLOC_START).
3237 - CONFIG_SYS_NONCACHED_MEMORY:
3238 Size of non-cached memory area. This area of memory will be
3239 typically located right below the malloc() area and mapped
3240 uncached in the MMU. This is useful for drivers that would
3241 otherwise require a lot of explicit cache maintenance. For
3242 some drivers it's also impossible to properly maintain the
3243 cache. For example if the regions that need to be flushed
3244 are not a multiple of the cache-line size, *and* padding
3245 cannot be allocated between the regions to align them (i.e.
3246 if the HW requires a contiguous array of regions, and the
3247 size of each region is not cache-aligned), then a flush of
3248 one region may result in overwriting data that hardware has
3249 written to another region in the same cache-line. This can
3250 happen for example in network drivers where descriptors for
3251 buffers are typically smaller than the CPU cache-line (e.g.
3252 16 bytes vs. 32 or 64 bytes).
3254 Non-cached memory is only supported on 32-bit ARM at present.
3256 - CONFIG_SYS_BOOTM_LEN:
3257 Normally compressed uImages are limited to an
3258 uncompressed size of 8 MBytes. If this is not enough,
3259 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3260 to adjust this setting to your needs.
3262 - CONFIG_SYS_BOOTMAPSZ:
3263 Maximum size of memory mapped by the startup code of
3264 the Linux kernel; all data that must be processed by
3265 the Linux kernel (bd_info, boot arguments, FDT blob if
3266 used) must be put below this limit, unless "bootm_low"
3267 environment variable is defined and non-zero. In such case
3268 all data for the Linux kernel must be between "bootm_low"
3269 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3270 variable "bootm_mapsize" will override the value of
3271 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3272 then the value in "bootm_size" will be used instead.
3274 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3275 Enable initrd_high functionality. If defined then the
3276 initrd_high feature is enabled and the bootm ramdisk subcommand
3279 - CONFIG_SYS_BOOT_GET_CMDLINE:
3280 Enables allocating and saving kernel cmdline in space between
3281 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3283 - CONFIG_SYS_BOOT_GET_KBD:
3284 Enables allocating and saving a kernel copy of the bd_info in
3285 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3287 - CONFIG_SYS_MAX_FLASH_BANKS:
3288 Max number of Flash memory banks
3290 - CONFIG_SYS_MAX_FLASH_SECT:
3291 Max number of sectors on a Flash chip
3293 - CONFIG_SYS_FLASH_ERASE_TOUT:
3294 Timeout for Flash erase operations (in ms)
3296 - CONFIG_SYS_FLASH_WRITE_TOUT:
3297 Timeout for Flash write operations (in ms)
3299 - CONFIG_SYS_FLASH_LOCK_TOUT
3300 Timeout for Flash set sector lock bit operation (in ms)
3302 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3303 Timeout for Flash clear lock bits operation (in ms)
3305 - CONFIG_SYS_FLASH_PROTECTION
3306 If defined, hardware flash sectors protection is used
3307 instead of U-Boot software protection.
3309 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3311 Enable TFTP transfers directly to flash memory;
3312 without this option such a download has to be
3313 performed in two steps: (1) download to RAM, and (2)
3314 copy from RAM to flash.
3316 The two-step approach is usually more reliable, since
3317 you can check if the download worked before you erase
3318 the flash, but in some situations (when system RAM is
3319 too limited to allow for a temporary copy of the
3320 downloaded image) this option may be very useful.
3322 - CONFIG_SYS_FLASH_CFI:
3323 Define if the flash driver uses extra elements in the
3324 common flash structure for storing flash geometry.
3326 - CONFIG_FLASH_CFI_DRIVER
3327 This option also enables the building of the cfi_flash driver
3328 in the drivers directory
3330 - CONFIG_FLASH_CFI_MTD
3331 This option enables the building of the cfi_mtd driver
3332 in the drivers directory. The driver exports CFI flash
3335 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3336 Use buffered writes to flash.
3338 - CONFIG_FLASH_SPANSION_S29WS_N
3339 s29ws-n MirrorBit flash has non-standard addresses for buffered
3342 - CONFIG_SYS_FLASH_QUIET_TEST
3343 If this option is defined, the common CFI flash doesn't
3344 print it's warning upon not recognized FLASH banks. This
3345 is useful, if some of the configured banks are only
3346 optionally available.
3348 - CONFIG_FLASH_SHOW_PROGRESS
3349 If defined (must be an integer), print out countdown
3350 digits and dots. Recommended value: 45 (9..1) for 80
3351 column displays, 15 (3..1) for 40 column displays.
3353 - CONFIG_FLASH_VERIFY
3354 If defined, the content of the flash (destination) is compared
3355 against the source after the write operation. An error message
3356 will be printed when the contents are not identical.
3357 Please note that this option is useless in nearly all cases,
3358 since such flash programming errors usually are detected earlier
3359 while unprotecting/erasing/programming. Please only enable
3360 this option if you really know what you are doing.
3362 - CONFIG_SYS_RX_ETH_BUFFER:
3363 Defines the number of Ethernet receive buffers. On some
3364 Ethernet controllers it is recommended to set this value
3365 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3366 buffers can be full shortly after enabling the interface
3367 on high Ethernet traffic.
3368 Defaults to 4 if not defined.
3370 - CONFIG_ENV_MAX_ENTRIES
3372 Maximum number of entries in the hash table that is used
3373 internally to store the environment settings. The default
3374 setting is supposed to be generous and should work in most
3375 cases. This setting can be used to tune behaviour; see
3376 lib/hashtable.c for details.
3378 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3379 - CONFIG_ENV_FLAGS_LIST_STATIC
3380 Enable validation of the values given to environment variables when
3381 calling env set. Variables can be restricted to only decimal,
3382 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3383 the variables can also be restricted to IP address or MAC address.
3385 The format of the list is:
3386 type_attribute = [s|d|x|b|i|m]
3387 access_attribute = [a|r|o|c]
3388 attributes = type_attribute[access_attribute]
3389 entry = variable_name[:attributes]
3392 The type attributes are:
3393 s - String (default)
3396 b - Boolean ([1yYtT|0nNfF])
3400 The access attributes are:
3406 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3407 Define this to a list (string) to define the ".flags"
3408 environment variable in the default or embedded environment.
3410 - CONFIG_ENV_FLAGS_LIST_STATIC
3411 Define this to a list (string) to define validation that
3412 should be done if an entry is not found in the ".flags"
3413 environment variable. To override a setting in the static
3414 list, simply add an entry for the same variable name to the
3417 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3418 regular expression. This allows multiple variables to define the same
3419 flags without explicitly listing them for each variable.
3421 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3422 If defined, don't allow the -f switch to env set override variable
3426 If stdint.h is available with your toolchain you can define this
3427 option to enable it. You can provide option 'USE_STDINT=1' when
3428 building U-Boot to enable this.
3430 The following definitions that deal with the placement and management
3431 of environment data (variable area); in general, we support the
3432 following configurations:
3434 - CONFIG_BUILD_ENVCRC:
3436 Builds up envcrc with the target environment so that external utils
3437 may easily extract it and embed it in final U-Boot images.
3439 - CONFIG_ENV_IS_IN_FLASH:
3441 Define this if the environment is in flash memory.
3443 a) The environment occupies one whole flash sector, which is
3444 "embedded" in the text segment with the U-Boot code. This
3445 happens usually with "bottom boot sector" or "top boot
3446 sector" type flash chips, which have several smaller
3447 sectors at the start or the end. For instance, such a
3448 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3449 such a case you would place the environment in one of the
3450 4 kB sectors - with U-Boot code before and after it. With
3451 "top boot sector" type flash chips, you would put the
3452 environment in one of the last sectors, leaving a gap
3453 between U-Boot and the environment.
3455 - CONFIG_ENV_OFFSET:
3457 Offset of environment data (variable area) to the
3458 beginning of flash memory; for instance, with bottom boot
3459 type flash chips the second sector can be used: the offset
3460 for this sector is given here.
3462 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3466 This is just another way to specify the start address of
3467 the flash sector containing the environment (instead of
3470 - CONFIG_ENV_SECT_SIZE:
3472 Size of the sector containing the environment.
3475 b) Sometimes flash chips have few, equal sized, BIG sectors.
3476 In such a case you don't want to spend a whole sector for
3481 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3482 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3483 of this flash sector for the environment. This saves
3484 memory for the RAM copy of the environment.
3486 It may also save flash memory if you decide to use this
3487 when your environment is "embedded" within U-Boot code,
3488 since then the remainder of the flash sector could be used
3489 for U-Boot code. It should be pointed out that this is
3490 STRONGLY DISCOURAGED from a robustness point of view:
3491 updating the environment in flash makes it always
3492 necessary to erase the WHOLE sector. If something goes
3493 wrong before the contents has been restored from a copy in
3494 RAM, your target system will be dead.
3496 - CONFIG_ENV_ADDR_REDUND
3497 CONFIG_ENV_SIZE_REDUND
3499 These settings describe a second storage area used to hold
3500 a redundant copy of the environment data, so that there is
3501 a valid backup copy in case there is a power failure during
3502 a "saveenv" operation.
3504 BE CAREFUL! Any changes to the flash layout, and some changes to the
3505 source code will make it necessary to adapt <board>/u-boot.lds*
3509 - CONFIG_ENV_IS_IN_NVRAM:
3511 Define this if you have some non-volatile memory device
3512 (NVRAM, battery buffered SRAM) which you want to use for the
3518 These two #defines are used to determine the memory area you
3519 want to use for environment. It is assumed that this memory
3520 can just be read and written to, without any special
3523 BE CAREFUL! The first access to the environment happens quite early
3524 in U-Boot initialization (when we try to get the setting of for the
3525 console baudrate). You *MUST* have mapped your NVRAM area then, or
3528 Please note that even with NVRAM we still use a copy of the
3529 environment in RAM: we could work on NVRAM directly, but we want to
3530 keep settings there always unmodified except somebody uses "saveenv"
3531 to save the current settings.
3534 - CONFIG_ENV_IS_IN_EEPROM:
3536 Use this if you have an EEPROM or similar serial access
3537 device and a driver for it.
3539 - CONFIG_ENV_OFFSET:
3542 These two #defines specify the offset and size of the
3543 environment area within the total memory of your EEPROM.
3545 - CONFIG_SYS_I2C_EEPROM_ADDR:
3546 If defined, specified the chip address of the EEPROM device.
3547 The default address is zero.
3549 - CONFIG_SYS_I2C_EEPROM_BUS:
3550 If defined, specified the i2c bus of the EEPROM device.
3552 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3553 If defined, the number of bits used to address bytes in a
3554 single page in the EEPROM device. A 64 byte page, for example
3555 would require six bits.
3557 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3558 If defined, the number of milliseconds to delay between
3559 page writes. The default is zero milliseconds.
3561 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3562 The length in bytes of the EEPROM memory array address. Note
3563 that this is NOT the chip address length!
3565 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3566 EEPROM chips that implement "address overflow" are ones
3567 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3568 address and the extra bits end up in the "chip address" bit
3569 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3572 Note that we consider the length of the address field to
3573 still be one byte because the extra address bits are hidden
3574 in the chip address.
3576 - CONFIG_SYS_EEPROM_SIZE:
3577 The size in bytes of the EEPROM device.
3579 - CONFIG_ENV_EEPROM_IS_ON_I2C
3580 define this, if you have I2C and SPI activated, and your
3581 EEPROM, which holds the environment, is on the I2C bus.
3583 - CONFIG_I2C_ENV_EEPROM_BUS
3584 if you have an Environment on an EEPROM reached over
3585 I2C muxes, you can define here, how to reach this
3586 EEPROM. For example:
3588 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3590 EEPROM which holds the environment, is reached over
3591 a pca9547 i2c mux with address 0x70, channel 3.
3593 - CONFIG_ENV_IS_IN_DATAFLASH:
3595 Define this if you have a DataFlash memory device which you
3596 want to use for the environment.
3598 - CONFIG_ENV_OFFSET:
3602 These three #defines specify the offset and size of the
3603 environment area within the total memory of your DataFlash placed
3604 at the specified address.
3606 - CONFIG_ENV_IS_IN_SPI_FLASH:
3608 Define this if you have a SPI Flash memory device which you
3609 want to use for the environment.
3611 - CONFIG_ENV_OFFSET:
3614 These two #defines specify the offset and size of the
3615 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3616 aligned to an erase sector boundary.
3618 - CONFIG_ENV_SECT_SIZE:
3620 Define the SPI flash's sector size.
3622 - CONFIG_ENV_OFFSET_REDUND (optional):
3624 This setting describes a second storage area of CONFIG_ENV_SIZE
3625 size used to hold a redundant copy of the environment data, so
3626 that there is a valid backup copy in case there is a power failure
3627 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3628 aligned to an erase sector boundary.
3630 - CONFIG_ENV_SPI_BUS (optional):
3631 - CONFIG_ENV_SPI_CS (optional):
3633 Define the SPI bus and chip select. If not defined they will be 0.
3635 - CONFIG_ENV_SPI_MAX_HZ (optional):
3637 Define the SPI max work clock. If not defined then use 1MHz.
3639 - CONFIG_ENV_SPI_MODE (optional):
3641 Define the SPI work mode. If not defined then use SPI_MODE_3.
3643 - CONFIG_ENV_IS_IN_REMOTE:
3645 Define this if you have a remote memory space which you
3646 want to use for the local device's environment.
3651 These two #defines specify the address and size of the
3652 environment area within the remote memory space. The
3653 local device can get the environment from remote memory
3654 space by SRIO or PCIE links.
3656 BE CAREFUL! For some special cases, the local device can not use
3657 "saveenv" command. For example, the local device will get the
3658 environment stored in a remote NOR flash by SRIO or PCIE link,
3659 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3661 - CONFIG_ENV_IS_IN_NAND:
3663 Define this if you have a NAND device which you want to use
3664 for the environment.
3666 - CONFIG_ENV_OFFSET:
3669 These two #defines specify the offset and size of the environment
3670 area within the first NAND device. CONFIG_ENV_OFFSET must be
3671 aligned to an erase block boundary.
3673 - CONFIG_ENV_OFFSET_REDUND (optional):
3675 This setting describes a second storage area of CONFIG_ENV_SIZE
3676 size used to hold a redundant copy of the environment data, so
3677 that there is a valid backup copy in case there is a power failure
3678 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3679 aligned to an erase block boundary.
3681 - CONFIG_ENV_RANGE (optional):
3683 Specifies the length of the region in which the environment
3684 can be written. This should be a multiple of the NAND device's
3685 block size. Specifying a range with more erase blocks than
3686 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3687 the range to be avoided.
3689 - CONFIG_ENV_OFFSET_OOB (optional):
3691 Enables support for dynamically retrieving the offset of the
3692 environment from block zero's out-of-band data. The
3693 "nand env.oob" command can be used to record this offset.
3694 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3695 using CONFIG_ENV_OFFSET_OOB.
3697 - CONFIG_NAND_ENV_DST
3699 Defines address in RAM to which the nand_spl code should copy the
3700 environment. If redundant environment is used, it will be copied to
3701 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3703 - CONFIG_ENV_IS_IN_UBI:
3705 Define this if you have an UBI volume that you want to use for the
3706 environment. This has the benefit of wear-leveling the environment
3707 accesses, which is important on NAND.
3709 - CONFIG_ENV_UBI_PART:
3711 Define this to a string that is the mtd partition containing the UBI.
3713 - CONFIG_ENV_UBI_VOLUME:
3715 Define this to the name of the volume that you want to store the
3718 - CONFIG_ENV_UBI_VOLUME_REDUND:
3720 Define this to the name of another volume to store a second copy of
3721 the environment in. This will enable redundant environments in UBI.
3722 It is assumed that both volumes are in the same MTD partition.
3724 - CONFIG_UBI_SILENCE_MSG
3725 - CONFIG_UBIFS_SILENCE_MSG
3727 You will probably want to define these to avoid a really noisy system
3728 when storing the env in UBI.
3730 - CONFIG_ENV_IS_IN_FAT:
3731 Define this if you want to use the FAT file system for the environment.
3733 - FAT_ENV_INTERFACE:
3735 Define this to a string that is the name of the block device.
3737 - FAT_ENV_DEVICE_AND_PART:
3739 Define this to a string to specify the partition of the device. It can
3742 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3743 - "D:P": device D partition P. Error occurs if device D has no
3746 - "D" or "D:": device D partition 1 if device D has partition
3747 table, or the whole device D if has no partition
3749 - "D:auto": first partition in device D with bootable flag set.
3750 If none, first valid partition in device D. If no
3751 partition table then means device D.
3755 It's a string of the FAT file name. This file use to store the
3759 This must be enabled. Otherwise it cannot save the environment file.
3761 - CONFIG_ENV_IS_IN_MMC:
3763 Define this if you have an MMC device which you want to use for the
3766 - CONFIG_SYS_MMC_ENV_DEV:
3768 Specifies which MMC device the environment is stored in.
3770 - CONFIG_SYS_MMC_ENV_PART (optional):
3772 Specifies which MMC partition the environment is stored in. If not
3773 set, defaults to partition 0, the user area. Common values might be
3774 1 (first MMC boot partition), 2 (second MMC boot partition).
3776 - CONFIG_ENV_OFFSET:
3779 These two #defines specify the offset and size of the environment
3780 area within the specified MMC device.
3782 If offset is positive (the usual case), it is treated as relative to
3783 the start of the MMC partition. If offset is negative, it is treated
3784 as relative to the end of the MMC partition. This can be useful if
3785 your board may be fitted with different MMC devices, which have
3786 different sizes for the MMC partitions, and you always want the
3787 environment placed at the very end of the partition, to leave the
3788 maximum possible space before it, to store other data.
3790 These two values are in units of bytes, but must be aligned to an
3791 MMC sector boundary.
3793 - CONFIG_ENV_OFFSET_REDUND (optional):
3795 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3796 hold a redundant copy of the environment data. This provides a
3797 valid backup copy in case the other copy is corrupted, e.g. due
3798 to a power failure during a "saveenv" operation.
3800 This value may also be positive or negative; this is handled in the
3801 same way as CONFIG_ENV_OFFSET.
3803 This value is also in units of bytes, but must also be aligned to
3804 an MMC sector boundary.
3806 - CONFIG_ENV_SIZE_REDUND (optional):
3808 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3809 set. If this value is set, it must be set to the same value as
3812 Please note that the environment is read-only until the monitor
3813 has been relocated to RAM and a RAM copy of the environment has been
3814 created; also, when using EEPROM you will have to use getenv_f()
3815 until then to read environment variables.
3817 The environment is protected by a CRC32 checksum. Before the monitor
3818 is relocated into RAM, as a result of a bad CRC you will be working
3819 with the compiled-in default environment - *silently*!!! [This is
3820 necessary, because the first environment variable we need is the
3821 "baudrate" setting for the console - if we have a bad CRC, we don't
3822 have any device yet where we could complain.]
3824 Note: once the monitor has been relocated, then it will complain if
3825 the default environment is used; a new CRC is computed as soon as you
3826 use the "saveenv" command to store a valid environment.
3828 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3829 Echo the inverted Ethernet link state to the fault LED.
3831 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3832 also needs to be defined.
3834 - CONFIG_SYS_FAULT_MII_ADDR:
3835 MII address of the PHY to check for the Ethernet link state.
3837 - CONFIG_NS16550_MIN_FUNCTIONS:
3838 Define this if you desire to only have use of the NS16550_init
3839 and NS16550_putc functions for the serial driver located at
3840 drivers/serial/ns16550.c. This option is useful for saving
3841 space for already greatly restricted images, including but not
3842 limited to NAND_SPL configurations.
3844 - CONFIG_DISPLAY_BOARDINFO
3845 Display information about the board that U-Boot is running on
3846 when U-Boot starts up. The board function checkboard() is called
3849 - CONFIG_DISPLAY_BOARDINFO_LATE
3850 Similar to the previous option, but display this information
3851 later, once stdio is running and output goes to the LCD, if
3854 - CONFIG_BOARD_SIZE_LIMIT:
3855 Maximum size of the U-Boot image. When defined, the
3856 build system checks that the actual size does not
3859 Low Level (hardware related) configuration options:
3860 ---------------------------------------------------
3862 - CONFIG_SYS_CACHELINE_SIZE:
3863 Cache Line Size of the CPU.
3865 - CONFIG_SYS_CCSRBAR_DEFAULT:
3866 Default (power-on reset) physical address of CCSR on Freescale
3869 - CONFIG_SYS_CCSRBAR:
3870 Virtual address of CCSR. On a 32-bit build, this is typically
3871 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3873 - CONFIG_SYS_CCSRBAR_PHYS:
3874 Physical address of CCSR. CCSR can be relocated to a new
3875 physical address, if desired. In this case, this macro should
3876 be set to that address. Otherwise, it should be set to the
3877 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3878 is typically relocated on 36-bit builds. It is recommended
3879 that this macro be defined via the _HIGH and _LOW macros:
3881 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3882 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3884 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3885 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3886 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3887 used in assembly code, so it must not contain typecasts or
3888 integer size suffixes (e.g. "ULL").
3890 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3891 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3892 used in assembly code, so it must not contain typecasts or
3893 integer size suffixes (e.g. "ULL").
3895 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3896 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3897 forced to a value that ensures that CCSR is not relocated.
3899 - Floppy Disk Support:
3900 CONFIG_SYS_FDC_DRIVE_NUMBER
3902 the default drive number (default value 0)
3904 CONFIG_SYS_ISA_IO_STRIDE
3906 defines the spacing between FDC chipset registers
3909 CONFIG_SYS_ISA_IO_OFFSET
3911 defines the offset of register from address. It
3912 depends on which part of the data bus is connected to
3913 the FDC chipset. (default value 0)
3915 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3916 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3919 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3920 fdc_hw_init() is called at the beginning of the FDC
3921 setup. fdc_hw_init() must be provided by the board
3922 source code. It is used to make hardware-dependent
3926 Most IDE controllers were designed to be connected with PCI
3927 interface. Only few of them were designed for AHB interface.
3928 When software is doing ATA command and data transfer to
3929 IDE devices through IDE-AHB controller, some additional
3930 registers accessing to these kind of IDE-AHB controller
3933 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3934 DO NOT CHANGE unless you know exactly what you're
3935 doing! (11-4) [82xx systems only]
3937 - CONFIG_SYS_INIT_RAM_ADDR:
3939 Start address of memory area that can be used for
3940 initial data and stack; please note that this must be
3941 writable memory that is working WITHOUT special
3942 initialization, i. e. you CANNOT use normal RAM which
3943 will become available only after programming the
3944 memory controller and running certain initialization
3947 U-Boot uses the following memory types:
3949 - CONFIG_SYS_GBL_DATA_OFFSET:
3951 Offset of the initial data structure in the memory
3952 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3953 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3954 data is located at the end of the available space
3955 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3956 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3957 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3958 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3961 On the MPC824X (or other systems that use the data
3962 cache for initial memory) the address chosen for
3963 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3964 point to an otherwise UNUSED address space between
3965 the top of RAM and the start of the PCI space.
3967 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3969 - CONFIG_SYS_OR_TIMING_SDRAM:
3972 - CONFIG_SYS_MAMR_PTA:
3973 periodic timer for refresh
3975 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3976 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3977 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3978 CONFIG_SYS_BR1_PRELIM:
3979 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3981 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3982 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3983 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3984 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3986 - CONFIG_PCI_ENUM_ONLY
3987 Only scan through and get the devices on the buses.
3988 Don't do any setup work, presumably because someone or
3989 something has already done it, and we don't need to do it
3990 a second time. Useful for platforms that are pre-booted
3991 by coreboot or similar.
3993 - CONFIG_PCI_INDIRECT_BRIDGE:
3994 Enable support for indirect PCI bridges.
3997 Chip has SRIO or not
4000 Board has SRIO 1 port available
4003 Board has SRIO 2 port available
4005 - CONFIG_SRIO_PCIE_BOOT_MASTER
4006 Board can support master function for Boot from SRIO and PCIE
4008 - CONFIG_SYS_SRIOn_MEM_VIRT:
4009 Virtual Address of SRIO port 'n' memory region
4011 - CONFIG_SYS_SRIOn_MEM_PHYS:
4012 Physical Address of SRIO port 'n' memory region
4014 - CONFIG_SYS_SRIOn_MEM_SIZE:
4015 Size of SRIO port 'n' memory region
4017 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4018 Defined to tell the NAND controller that the NAND chip is using
4020 Not all NAND drivers use this symbol.
4021 Example of drivers that use it:
4022 - drivers/mtd/nand/ndfc.c
4023 - drivers/mtd/nand/mxc_nand.c
4025 - CONFIG_SYS_NDFC_EBC0_CFG
4026 Sets the EBC0_CFG register for the NDFC. If not defined
4027 a default value will be used.
4030 Get DDR timing information from an I2C EEPROM. Common
4031 with pluggable memory modules such as SODIMMs
4034 I2C address of the SPD EEPROM
4036 - CONFIG_SYS_SPD_BUS_NUM
4037 If SPD EEPROM is on an I2C bus other than the first
4038 one, specify here. Note that the value must resolve
4039 to something your driver can deal with.
4041 - CONFIG_SYS_DDR_RAW_TIMING
4042 Get DDR timing information from other than SPD. Common with
4043 soldered DDR chips onboard without SPD. DDR raw timing
4044 parameters are extracted from datasheet and hard-coded into
4045 header files or board specific files.
4047 - CONFIG_FSL_DDR_INTERACTIVE
4048 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4050 - CONFIG_FSL_DDR_SYNC_REFRESH
4051 Enable sync of refresh for multiple controllers.
4053 - CONFIG_FSL_DDR_BIST
4054 Enable built-in memory test for Freescale DDR controllers.
4056 - CONFIG_SYS_83XX_DDR_USES_CS0
4057 Only for 83xx systems. If specified, then DDR should
4058 be configured using CS0 and CS1 instead of CS2 and CS3.
4061 Enable RMII mode for all FECs.
4062 Note that this is a global option, we can't
4063 have one FEC in standard MII mode and another in RMII mode.
4065 - CONFIG_CRC32_VERIFY
4066 Add a verify option to the crc32 command.
4069 => crc32 -v <address> <count> <crc32>
4071 Where address/count indicate a memory area
4072 and crc32 is the correct crc32 which the
4076 Add the "loopw" memory command. This only takes effect if
4077 the memory commands are activated globally (CONFIG_CMD_MEM).
4080 Add the "mdc" and "mwc" memory commands. These are cyclic
4085 This command will print 4 bytes (10,11,12,13) each 500 ms.
4087 => mwc.l 100 12345678 10
4088 This command will write 12345678 to address 100 all 10 ms.
4090 This only takes effect if the memory commands are activated
4091 globally (CONFIG_CMD_MEM).
4093 - CONFIG_SKIP_LOWLEVEL_INIT
4094 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4095 low level initializations (like setting up the memory
4096 controller) are omitted and/or U-Boot does not
4097 relocate itself into RAM.
4099 Normally this variable MUST NOT be defined. The only
4100 exception is when U-Boot is loaded (to RAM) by some
4101 other boot loader or by a debugger which performs
4102 these initializations itself.
4104 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4105 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4106 to be skipped. The normal CP15 init (such as enabling the
4107 instruction cache) is still performed.
4110 Modifies the behaviour of start.S when compiling a loader
4111 that is executed before the actual U-Boot. E.g. when
4112 compiling a NAND SPL.
4115 Modifies the behaviour of start.S when compiling a loader
4116 that is executed after the SPL and before the actual U-Boot.
4117 It is loaded by the SPL.
4119 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4120 Only for 85xx systems. If this variable is specified, the section
4121 .resetvec is not kept and the section .bootpg is placed in the
4122 previous 4k of the .text section.
4124 - CONFIG_ARCH_MAP_SYSMEM
4125 Generally U-Boot (and in particular the md command) uses
4126 effective address. It is therefore not necessary to regard
4127 U-Boot address as virtual addresses that need to be translated
4128 to physical addresses. However, sandbox requires this, since
4129 it maintains its own little RAM buffer which contains all
4130 addressable memory. This option causes some memory accesses
4131 to be mapped through map_sysmem() / unmap_sysmem().
4133 - CONFIG_X86_RESET_VECTOR
4134 If defined, the x86 reset vector code is included. This is not
4135 needed when U-Boot is running from Coreboot.
4137 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4138 Enables the RTC32K OSC on AM33xx based plattforms
4140 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4141 Option to disable subpage write in NAND driver
4142 driver that uses this:
4143 drivers/mtd/nand/davinci_nand.c
4145 Freescale QE/FMAN Firmware Support:
4146 -----------------------------------
4148 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4149 loading of "firmware", which is encoded in the QE firmware binary format.
4150 This firmware often needs to be loaded during U-Boot booting, so macros
4151 are used to identify the storage device (NOR flash, SPI, etc) and the address
4154 - CONFIG_SYS_FMAN_FW_ADDR
4155 The address in the storage device where the FMAN microcode is located. The
4156 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4159 - CONFIG_SYS_QE_FW_ADDR
4160 The address in the storage device where the QE microcode is located. The
4161 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4164 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4165 The maximum possible size of the firmware. The firmware binary format
4166 has a field that specifies the actual size of the firmware, but it
4167 might not be possible to read any part of the firmware unless some
4168 local storage is allocated to hold the entire firmware first.
4170 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4171 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4172 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4173 virtual address in NOR flash.
4175 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4176 Specifies that QE/FMAN firmware is located in NAND flash.
4177 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4179 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4180 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4181 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4183 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4184 Specifies that QE/FMAN firmware is located in the remote (master)
4185 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4186 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4187 window->master inbound window->master LAW->the ucode address in
4188 master's memory space.
4190 Freescale Layerscape Management Complex Firmware Support:
4191 ---------------------------------------------------------
4192 The Freescale Layerscape Management Complex (MC) supports the loading of
4194 This firmware often needs to be loaded during U-Boot booting, so macros
4195 are used to identify the storage device (NOR flash, SPI, etc) and the address
4198 - CONFIG_FSL_MC_ENET
4199 Enable the MC driver for Layerscape SoCs.
4201 Freescale Layerscape Debug Server Support:
4202 -------------------------------------------
4203 The Freescale Layerscape Debug Server Support supports the loading of
4204 "Debug Server firmware" and triggering SP boot-rom.
4205 This firmware often needs to be loaded during U-Boot booting.
4207 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4208 Define alignment of reserved memory MC requires
4213 In order to achieve reproducible builds, timestamps used in the U-Boot build
4214 process have to be set to a fixed value.
4216 This is done using the SOURCE_DATE_EPOCH environment variable.
4217 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4218 option for U-Boot or an environment variable in U-Boot.
4220 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4222 Building the Software:
4223 ======================
4225 Building U-Boot has been tested in several native build environments
4226 and in many different cross environments. Of course we cannot support
4227 all possibly existing versions of cross development tools in all
4228 (potentially obsolete) versions. In case of tool chain problems we
4229 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4230 which is extensively used to build and test U-Boot.
4232 If you are not using a native environment, it is assumed that you
4233 have GNU cross compiling tools available in your path. In this case,
4234 you must set the environment variable CROSS_COMPILE in your shell.
4235 Note that no changes to the Makefile or any other source files are
4236 necessary. For example using the ELDK on a 4xx CPU, please enter:
4238 $ CROSS_COMPILE=ppc_4xx-
4239 $ export CROSS_COMPILE
4241 Note: If you wish to generate Windows versions of the utilities in
4242 the tools directory you can use the MinGW toolchain
4243 (http://www.mingw.org). Set your HOST tools to the MinGW
4244 toolchain and execute 'make tools'. For example:
4246 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4248 Binaries such as tools/mkimage.exe will be created which can
4249 be executed on computers running Windows.
4251 U-Boot is intended to be simple to build. After installing the
4252 sources you must configure U-Boot for one specific board type. This
4257 where "NAME_defconfig" is the name of one of the existing configu-
4258 rations; see boards.cfg for supported names.
4260 Note: for some board special configuration names may exist; check if
4261 additional information is available from the board vendor; for
4262 instance, the TQM823L systems are available without (standard)
4263 or with LCD support. You can select such additional "features"
4264 when choosing the configuration, i. e.
4266 make TQM823L_defconfig
4267 - will configure for a plain TQM823L, i. e. no LCD support
4269 make TQM823L_LCD_defconfig
4270 - will configure for a TQM823L with U-Boot console on LCD
4275 Finally, type "make all", and you should get some working U-Boot
4276 images ready for download to / installation on your system:
4278 - "u-boot.bin" is a raw binary image
4279 - "u-boot" is an image in ELF binary format
4280 - "u-boot.srec" is in Motorola S-Record format
4282 By default the build is performed locally and the objects are saved
4283 in the source directory. One of the two methods can be used to change
4284 this behavior and build U-Boot to some external directory:
4286 1. Add O= to the make command line invocations:
4288 make O=/tmp/build distclean
4289 make O=/tmp/build NAME_defconfig
4290 make O=/tmp/build all
4292 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4294 export KBUILD_OUTPUT=/tmp/build
4299 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4303 Please be aware that the Makefiles assume you are using GNU make, so
4304 for instance on NetBSD you might need to use "gmake" instead of
4308 If the system board that you have is not listed, then you will need
4309 to port U-Boot to your hardware platform. To do this, follow these
4312 1. Create a new directory to hold your board specific code. Add any
4313 files you need. In your board directory, you will need at least
4314 the "Makefile" and a "<board>.c".
4315 2. Create a new configuration file "include/configs/<board>.h" for
4317 3. If you're porting U-Boot to a new CPU, then also create a new
4318 directory to hold your CPU specific code. Add any files you need.
4319 4. Run "make <board>_defconfig" with your new name.
4320 5. Type "make", and you should get a working "u-boot.srec" file
4321 to be installed on your target system.
4322 6. Debug and solve any problems that might arise.
4323 [Of course, this last step is much harder than it sounds.]
4326 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4327 ==============================================================
4329 If you have modified U-Boot sources (for instance added a new board
4330 or support for new devices, a new CPU, etc.) you are expected to
4331 provide feedback to the other developers. The feedback normally takes
4332 the form of a "patch", i. e. a context diff against a certain (latest
4333 official or latest in the git repository) version of U-Boot sources.
4335 But before you submit such a patch, please verify that your modifi-
4336 cation did not break existing code. At least make sure that *ALL* of
4337 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4338 just run the buildman script (tools/buildman/buildman), which will
4339 configure and build U-Boot for ALL supported system. Be warned, this
4340 will take a while. Please see the buildman README, or run 'buildman -H'
4344 See also "U-Boot Porting Guide" below.
4347 Monitor Commands - Overview:
4348 ============================
4350 go - start application at address 'addr'
4351 run - run commands in an environment variable
4352 bootm - boot application image from memory
4353 bootp - boot image via network using BootP/TFTP protocol
4354 bootz - boot zImage from memory
4355 tftpboot- boot image via network using TFTP protocol
4356 and env variables "ipaddr" and "serverip"
4357 (and eventually "gatewayip")
4358 tftpput - upload a file via network using TFTP protocol
4359 rarpboot- boot image via network using RARP/TFTP protocol
4360 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4361 loads - load S-Record file over serial line
4362 loadb - load binary file over serial line (kermit mode)
4364 mm - memory modify (auto-incrementing)
4365 nm - memory modify (constant address)
4366 mw - memory write (fill)
4368 cmp - memory compare
4369 crc32 - checksum calculation
4370 i2c - I2C sub-system
4371 sspi - SPI utility commands
4372 base - print or set address offset
4373 printenv- print environment variables
4374 setenv - set environment variables
4375 saveenv - save environment variables to persistent storage
4376 protect - enable or disable FLASH write protection
4377 erase - erase FLASH memory
4378 flinfo - print FLASH memory information
4379 nand - NAND memory operations (see doc/README.nand)
4380 bdinfo - print Board Info structure
4381 iminfo - print header information for application image
4382 coninfo - print console devices and informations
4383 ide - IDE sub-system
4384 loop - infinite loop on address range
4385 loopw - infinite write loop on address range
4386 mtest - simple RAM test
4387 icache - enable or disable instruction cache
4388 dcache - enable or disable data cache
4389 reset - Perform RESET of the CPU
4390 echo - echo args to console
4391 version - print monitor version
4392 help - print online help
4393 ? - alias for 'help'
4396 Monitor Commands - Detailed Description:
4397 ========================================
4401 For now: just type "help <command>".
4404 Environment Variables:
4405 ======================
4407 U-Boot supports user configuration using Environment Variables which
4408 can be made persistent by saving to Flash memory.
4410 Environment Variables are set using "setenv", printed using
4411 "printenv", and saved to Flash using "saveenv". Using "setenv"
4412 without a value can be used to delete a variable from the
4413 environment. As long as you don't save the environment you are
4414 working with an in-memory copy. In case the Flash area containing the
4415 environment is erased by accident, a default environment is provided.
4417 Some configuration options can be set using Environment Variables.
4419 List of environment variables (most likely not complete):
4421 baudrate - see CONFIG_BAUDRATE
4423 bootdelay - see CONFIG_BOOTDELAY
4425 bootcmd - see CONFIG_BOOTCOMMAND
4427 bootargs - Boot arguments when booting an RTOS image
4429 bootfile - Name of the image to load with TFTP
4431 bootm_low - Memory range available for image processing in the bootm
4432 command can be restricted. This variable is given as
4433 a hexadecimal number and defines lowest address allowed
4434 for use by the bootm command. See also "bootm_size"
4435 environment variable. Address defined by "bootm_low" is
4436 also the base of the initial memory mapping for the Linux
4437 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4440 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4441 This variable is given as a hexadecimal number and it
4442 defines the size of the memory region starting at base
4443 address bootm_low that is accessible by the Linux kernel
4444 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4445 as the default value if it is defined, and bootm_size is
4448 bootm_size - Memory range available for image processing in the bootm
4449 command can be restricted. This variable is given as
4450 a hexadecimal number and defines the size of the region
4451 allowed for use by the bootm command. See also "bootm_low"
4452 environment variable.
4454 updatefile - Location of the software update file on a TFTP server, used
4455 by the automatic software update feature. Please refer to
4456 documentation in doc/README.update for more details.
4458 autoload - if set to "no" (any string beginning with 'n'),
4459 "bootp" will just load perform a lookup of the
4460 configuration from the BOOTP server, but not try to
4461 load any image using TFTP
4463 autostart - if set to "yes", an image loaded using the "bootp",
4464 "rarpboot", "tftpboot" or "diskboot" commands will
4465 be automatically started (by internally calling
4468 If set to "no", a standalone image passed to the
4469 "bootm" command will be copied to the load address
4470 (and eventually uncompressed), but NOT be started.
4471 This can be used to load and uncompress arbitrary
4474 fdt_high - if set this restricts the maximum address that the
4475 flattened device tree will be copied into upon boot.
4476 For example, if you have a system with 1 GB memory
4477 at physical address 0x10000000, while Linux kernel
4478 only recognizes the first 704 MB as low memory, you
4479 may need to set fdt_high as 0x3C000000 to have the
4480 device tree blob be copied to the maximum address
4481 of the 704 MB low memory, so that Linux kernel can
4482 access it during the boot procedure.
4484 If this is set to the special value 0xFFFFFFFF then
4485 the fdt will not be copied at all on boot. For this
4486 to work it must reside in writable memory, have
4487 sufficient padding on the end of it for u-boot to
4488 add the information it needs into it, and the memory
4489 must be accessible by the kernel.
4491 fdtcontroladdr- if set this is the address of the control flattened
4492 device tree used by U-Boot when CONFIG_OF_CONTROL is
4495 i2cfast - (PPC405GP|PPC405EP only)
4496 if set to 'y' configures Linux I2C driver for fast
4497 mode (400kHZ). This environment variable is used in
4498 initialization code. So, for changes to be effective
4499 it must be saved and board must be reset.
4501 initrd_high - restrict positioning of initrd images:
4502 If this variable is not set, initrd images will be
4503 copied to the highest possible address in RAM; this
4504 is usually what you want since it allows for
4505 maximum initrd size. If for some reason you want to
4506 make sure that the initrd image is loaded below the
4507 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4508 variable to a value of "no" or "off" or "0".
4509 Alternatively, you can set it to a maximum upper
4510 address to use (U-Boot will still check that it
4511 does not overwrite the U-Boot stack and data).
4513 For instance, when you have a system with 16 MB
4514 RAM, and want to reserve 4 MB from use by Linux,
4515 you can do this by adding "mem=12M" to the value of
4516 the "bootargs" variable. However, now you must make
4517 sure that the initrd image is placed in the first
4518 12 MB as well - this can be done with
4520 setenv initrd_high 00c00000
4522 If you set initrd_high to 0xFFFFFFFF, this is an
4523 indication to U-Boot that all addresses are legal
4524 for the Linux kernel, including addresses in flash
4525 memory. In this case U-Boot will NOT COPY the
4526 ramdisk at all. This may be useful to reduce the
4527 boot time on your system, but requires that this
4528 feature is supported by your Linux kernel.
4530 ipaddr - IP address; needed for tftpboot command
4532 loadaddr - Default load address for commands like "bootp",
4533 "rarpboot", "tftpboot", "loadb" or "diskboot"
4535 loads_echo - see CONFIG_LOADS_ECHO
4537 serverip - TFTP server IP address; needed for tftpboot command
4539 bootretry - see CONFIG_BOOT_RETRY_TIME
4541 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4543 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4545 ethprime - controls which interface is used first.
4547 ethact - controls which interface is currently active.
4548 For example you can do the following
4550 => setenv ethact FEC
4551 => ping 192.168.0.1 # traffic sent on FEC
4552 => setenv ethact SCC
4553 => ping 10.0.0.1 # traffic sent on SCC
4555 ethrotate - When set to "no" U-Boot does not go through all
4556 available network interfaces.
4557 It just stays at the currently selected interface.
4559 netretry - When set to "no" each network operation will
4560 either succeed or fail without retrying.
4561 When set to "once" the network operation will
4562 fail when all the available network interfaces
4563 are tried once without success.
4564 Useful on scripts which control the retry operation
4567 npe_ucode - set load address for the NPE microcode
4569 silent_linux - If set then Linux will be told to boot silently, by
4570 changing the console to be empty. If "yes" it will be
4571 made silent. If "no" it will not be made silent. If
4572 unset, then it will be made silent if the U-Boot console
4575 tftpsrcp - If this is set, the value is used for TFTP's
4578 tftpdstp - If this is set, the value is used for TFTP's UDP
4579 destination port instead of the Well Know Port 69.
4581 tftpblocksize - Block size to use for TFTP transfers; if not set,
4582 we use the TFTP server's default block size
4584 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4585 seconds, minimum value is 1000 = 1 second). Defines
4586 when a packet is considered to be lost so it has to
4587 be retransmitted. The default is 5000 = 5 seconds.
4588 Lowering this value may make downloads succeed
4589 faster in networks with high packet loss rates or
4590 with unreliable TFTP servers.
4592 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4593 unit, minimum value = 0). Defines how many timeouts
4594 can happen during a single file transfer before that
4595 transfer is aborted. The default is 10, and 0 means
4596 'no timeouts allowed'. Increasing this value may help
4597 downloads succeed with high packet loss rates, or with
4598 unreliable TFTP servers or client hardware.
4600 vlan - When set to a value < 4095 the traffic over
4601 Ethernet is encapsulated/received over 802.1q
4604 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4605 Unsigned value, in milliseconds. If not set, the period will
4606 be either the default (28000), or a value based on
4607 CONFIG_NET_RETRY_COUNT, if defined. This value has
4608 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4610 The following image location variables contain the location of images
4611 used in booting. The "Image" column gives the role of the image and is
4612 not an environment variable name. The other columns are environment
4613 variable names. "File Name" gives the name of the file on a TFTP
4614 server, "RAM Address" gives the location in RAM the image will be
4615 loaded to, and "Flash Location" gives the image's address in NOR
4616 flash or offset in NAND flash.
4618 *Note* - these variables don't have to be defined for all boards, some
4619 boards currently use other variables for these purposes, and some
4620 boards use these variables for other purposes.
4622 Image File Name RAM Address Flash Location
4623 ----- --------- ----------- --------------
4624 u-boot u-boot u-boot_addr_r u-boot_addr
4625 Linux kernel bootfile kernel_addr_r kernel_addr
4626 device tree blob fdtfile fdt_addr_r fdt_addr
4627 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4629 The following environment variables may be used and automatically
4630 updated by the network boot commands ("bootp" and "rarpboot"),
4631 depending the information provided by your boot server:
4633 bootfile - see above
4634 dnsip - IP address of your Domain Name Server
4635 dnsip2 - IP address of your secondary Domain Name Server
4636 gatewayip - IP address of the Gateway (Router) to use
4637 hostname - Target hostname
4639 netmask - Subnet Mask
4640 rootpath - Pathname of the root filesystem on the NFS server
4641 serverip - see above
4644 There are two special Environment Variables:
4646 serial# - contains hardware identification information such
4647 as type string and/or serial number
4648 ethaddr - Ethernet address
4650 These variables can be set only once (usually during manufacturing of
4651 the board). U-Boot refuses to delete or overwrite these variables
4652 once they have been set once.
4655 Further special Environment Variables:
4657 ver - Contains the U-Boot version string as printed
4658 with the "version" command. This variable is
4659 readonly (see CONFIG_VERSION_VARIABLE).
4662 Please note that changes to some configuration parameters may take
4663 only effect after the next boot (yes, that's just like Windoze :-).
4666 Callback functions for environment variables:
4667 ---------------------------------------------
4669 For some environment variables, the behavior of u-boot needs to change
4670 when their values are changed. This functionality allows functions to
4671 be associated with arbitrary variables. On creation, overwrite, or
4672 deletion, the callback will provide the opportunity for some side
4673 effect to happen or for the change to be rejected.
4675 The callbacks are named and associated with a function using the
4676 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4678 These callbacks are associated with variables in one of two ways. The
4679 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4680 in the board configuration to a string that defines a list of
4681 associations. The list must be in the following format:
4683 entry = variable_name[:callback_name]
4686 If the callback name is not specified, then the callback is deleted.
4687 Spaces are also allowed anywhere in the list.
4689 Callbacks can also be associated by defining the ".callbacks" variable
4690 with the same list format above. Any association in ".callbacks" will
4691 override any association in the static list. You can define
4692 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4693 ".callbacks" environment variable in the default or embedded environment.
4695 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4696 regular expression. This allows multiple variables to be connected to
4697 the same callback without explicitly listing them all out.
4700 Command Line Parsing:
4701 =====================
4703 There are two different command line parsers available with U-Boot:
4704 the old "simple" one, and the much more powerful "hush" shell:
4706 Old, simple command line parser:
4707 --------------------------------
4709 - supports environment variables (through setenv / saveenv commands)
4710 - several commands on one line, separated by ';'
4711 - variable substitution using "... ${name} ..." syntax
4712 - special characters ('$', ';') can be escaped by prefixing with '\',
4714 setenv bootcmd bootm \${address}
4715 - You can also escape text by enclosing in single apostrophes, for example:
4716 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4721 - similar to Bourne shell, with control structures like
4722 if...then...else...fi, for...do...done; while...do...done,
4723 until...do...done, ...
4724 - supports environment ("global") variables (through setenv / saveenv
4725 commands) and local shell variables (through standard shell syntax
4726 "name=value"); only environment variables can be used with "run"
4732 (1) If a command line (or an environment variable executed by a "run"
4733 command) contains several commands separated by semicolon, and
4734 one of these commands fails, then the remaining commands will be
4737 (2) If you execute several variables with one call to run (i. e.
4738 calling run with a list of variables as arguments), any failing
4739 command will cause "run" to terminate, i. e. the remaining
4740 variables are not executed.
4742 Note for Redundant Ethernet Interfaces:
4743 =======================================
4745 Some boards come with redundant Ethernet interfaces; U-Boot supports
4746 such configurations and is capable of automatic selection of a
4747 "working" interface when needed. MAC assignment works as follows:
4749 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4750 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4751 "eth1addr" (=>eth1), "eth2addr", ...
4753 If the network interface stores some valid MAC address (for instance
4754 in SROM), this is used as default address if there is NO correspon-
4755 ding setting in the environment; if the corresponding environment
4756 variable is set, this overrides the settings in the card; that means:
4758 o If the SROM has a valid MAC address, and there is no address in the
4759 environment, the SROM's address is used.
4761 o If there is no valid address in the SROM, and a definition in the
4762 environment exists, then the value from the environment variable is
4765 o If both the SROM and the environment contain a MAC address, and
4766 both addresses are the same, this MAC address is used.
4768 o If both the SROM and the environment contain a MAC address, and the
4769 addresses differ, the value from the environment is used and a
4772 o If neither SROM nor the environment contain a MAC address, an error
4773 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4774 a random, locally-assigned MAC is used.
4776 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4777 will be programmed into hardware as part of the initialization process. This
4778 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4779 The naming convention is as follows:
4780 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4785 U-Boot is capable of booting (and performing other auxiliary operations on)
4786 images in two formats:
4788 New uImage format (FIT)
4789 -----------------------
4791 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4792 to Flattened Device Tree). It allows the use of images with multiple
4793 components (several kernels, ramdisks, etc.), with contents protected by
4794 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4800 Old image format is based on binary files which can be basically anything,
4801 preceded by a special header; see the definitions in include/image.h for
4802 details; basically, the header defines the following image properties:
4804 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4805 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4806 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4807 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4809 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4810 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4811 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4812 * Compression Type (uncompressed, gzip, bzip2)
4818 The header is marked by a special Magic Number, and both the header
4819 and the data portions of the image are secured against corruption by
4826 Although U-Boot should support any OS or standalone application
4827 easily, the main focus has always been on Linux during the design of
4830 U-Boot includes many features that so far have been part of some
4831 special "boot loader" code within the Linux kernel. Also, any
4832 "initrd" images to be used are no longer part of one big Linux image;
4833 instead, kernel and "initrd" are separate images. This implementation
4834 serves several purposes:
4836 - the same features can be used for other OS or standalone
4837 applications (for instance: using compressed images to reduce the
4838 Flash memory footprint)
4840 - it becomes much easier to port new Linux kernel versions because
4841 lots of low-level, hardware dependent stuff are done by U-Boot
4843 - the same Linux kernel image can now be used with different "initrd"
4844 images; of course this also means that different kernel images can
4845 be run with the same "initrd". This makes testing easier (you don't
4846 have to build a new "zImage.initrd" Linux image when you just
4847 change a file in your "initrd"). Also, a field-upgrade of the
4848 software is easier now.
4854 Porting Linux to U-Boot based systems:
4855 ---------------------------------------
4857 U-Boot cannot save you from doing all the necessary modifications to
4858 configure the Linux device drivers for use with your target hardware
4859 (no, we don't intend to provide a full virtual machine interface to
4862 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4864 Just make sure your machine specific header file (for instance
4865 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4866 Information structure as we define in include/asm-<arch>/u-boot.h,
4867 and make sure that your definition of IMAP_ADDR uses the same value
4868 as your U-Boot configuration in CONFIG_SYS_IMMR.
4870 Note that U-Boot now has a driver model, a unified model for drivers.
4871 If you are adding a new driver, plumb it into driver model. If there
4872 is no uclass available, you are encouraged to create one. See
4876 Configuring the Linux kernel:
4877 -----------------------------
4879 No specific requirements for U-Boot. Make sure you have some root
4880 device (initial ramdisk, NFS) for your target system.
4883 Building a Linux Image:
4884 -----------------------
4886 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4887 not used. If you use recent kernel source, a new build target
4888 "uImage" will exist which automatically builds an image usable by
4889 U-Boot. Most older kernels also have support for a "pImage" target,
4890 which was introduced for our predecessor project PPCBoot and uses a
4891 100% compatible format.
4895 make TQM850L_defconfig
4900 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4901 encapsulate a compressed Linux kernel image with header information,
4902 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4904 * build a standard "vmlinux" kernel image (in ELF binary format):
4906 * convert the kernel into a raw binary image:
4908 ${CROSS_COMPILE}-objcopy -O binary \
4909 -R .note -R .comment \
4910 -S vmlinux linux.bin
4912 * compress the binary image:
4916 * package compressed binary image for U-Boot:
4918 mkimage -A ppc -O linux -T kernel -C gzip \
4919 -a 0 -e 0 -n "Linux Kernel Image" \
4920 -d linux.bin.gz uImage
4923 The "mkimage" tool can also be used to create ramdisk images for use
4924 with U-Boot, either separated from the Linux kernel image, or
4925 combined into one file. "mkimage" encapsulates the images with a 64
4926 byte header containing information about target architecture,
4927 operating system, image type, compression method, entry points, time
4928 stamp, CRC32 checksums, etc.
4930 "mkimage" can be called in two ways: to verify existing images and
4931 print the header information, or to build new images.
4933 In the first form (with "-l" option) mkimage lists the information
4934 contained in the header of an existing U-Boot image; this includes
4935 checksum verification:
4937 tools/mkimage -l image
4938 -l ==> list image header information
4940 The second form (with "-d" option) is used to build a U-Boot image
4941 from a "data file" which is used as image payload:
4943 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4944 -n name -d data_file image
4945 -A ==> set architecture to 'arch'
4946 -O ==> set operating system to 'os'
4947 -T ==> set image type to 'type'
4948 -C ==> set compression type 'comp'
4949 -a ==> set load address to 'addr' (hex)
4950 -e ==> set entry point to 'ep' (hex)
4951 -n ==> set image name to 'name'
4952 -d ==> use image data from 'datafile'
4954 Right now, all Linux kernels for PowerPC systems use the same load
4955 address (0x00000000), but the entry point address depends on the
4958 - 2.2.x kernels have the entry point at 0x0000000C,
4959 - 2.3.x and later kernels have the entry point at 0x00000000.
4961 So a typical call to build a U-Boot image would read:
4963 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4964 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4965 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4966 > examples/uImage.TQM850L
4967 Image Name: 2.4.4 kernel for TQM850L
4968 Created: Wed Jul 19 02:34:59 2000
4969 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4970 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4971 Load Address: 0x00000000
4972 Entry Point: 0x00000000
4974 To verify the contents of the image (or check for corruption):
4976 -> tools/mkimage -l examples/uImage.TQM850L
4977 Image Name: 2.4.4 kernel for TQM850L
4978 Created: Wed Jul 19 02:34:59 2000
4979 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4980 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4981 Load Address: 0x00000000
4982 Entry Point: 0x00000000
4984 NOTE: for embedded systems where boot time is critical you can trade
4985 speed for memory and install an UNCOMPRESSED image instead: this
4986 needs more space in Flash, but boots much faster since it does not
4987 need to be uncompressed:
4989 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4990 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4991 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4992 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4993 > examples/uImage.TQM850L-uncompressed
4994 Image Name: 2.4.4 kernel for TQM850L
4995 Created: Wed Jul 19 02:34:59 2000
4996 Image Type: PowerPC Linux Kernel Image (uncompressed)
4997 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4998 Load Address: 0x00000000
4999 Entry Point: 0x00000000
5002 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5003 when your kernel is intended to use an initial ramdisk:
5005 -> tools/mkimage -n 'Simple Ramdisk Image' \
5006 > -A ppc -O linux -T ramdisk -C gzip \
5007 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5008 Image Name: Simple Ramdisk Image
5009 Created: Wed Jan 12 14:01:50 2000
5010 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5011 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5012 Load Address: 0x00000000
5013 Entry Point: 0x00000000
5015 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5016 option performs the converse operation of the mkimage's second form (the "-d"
5017 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5020 tools/dumpimage -i image -T type -p position data_file
5021 -i ==> extract from the 'image' a specific 'data_file'
5022 -T ==> set image type to 'type'
5023 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5026 Installing a Linux Image:
5027 -------------------------
5029 To downloading a U-Boot image over the serial (console) interface,
5030 you must convert the image to S-Record format:
5032 objcopy -I binary -O srec examples/image examples/image.srec
5034 The 'objcopy' does not understand the information in the U-Boot
5035 image header, so the resulting S-Record file will be relative to
5036 address 0x00000000. To load it to a given address, you need to
5037 specify the target address as 'offset' parameter with the 'loads'
5040 Example: install the image to address 0x40100000 (which on the
5041 TQM8xxL is in the first Flash bank):
5043 => erase 40100000 401FFFFF
5049 ## Ready for S-Record download ...
5050 ~>examples/image.srec
5051 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5053 15989 15990 15991 15992
5054 [file transfer complete]
5056 ## Start Addr = 0x00000000
5059 You can check the success of the download using the 'iminfo' command;
5060 this includes a checksum verification so you can be sure no data
5061 corruption happened:
5065 ## Checking Image at 40100000 ...
5066 Image Name: 2.2.13 for initrd on TQM850L
5067 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5068 Data Size: 335725 Bytes = 327 kB = 0 MB
5069 Load Address: 00000000
5070 Entry Point: 0000000c
5071 Verifying Checksum ... OK
5077 The "bootm" command is used to boot an application that is stored in
5078 memory (RAM or Flash). In case of a Linux kernel image, the contents
5079 of the "bootargs" environment variable is passed to the kernel as
5080 parameters. You can check and modify this variable using the
5081 "printenv" and "setenv" commands:
5084 => printenv bootargs
5085 bootargs=root=/dev/ram
5087 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5089 => printenv bootargs
5090 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5093 ## Booting Linux kernel at 40020000 ...
5094 Image Name: 2.2.13 for NFS on TQM850L
5095 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5096 Data Size: 381681 Bytes = 372 kB = 0 MB
5097 Load Address: 00000000
5098 Entry Point: 0000000c
5099 Verifying Checksum ... OK
5100 Uncompressing Kernel Image ... OK
5101 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
5102 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5103 time_init: decrementer frequency = 187500000/60
5104 Calibrating delay loop... 49.77 BogoMIPS
5105 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5108 If you want to boot a Linux kernel with initial RAM disk, you pass
5109 the memory addresses of both the kernel and the initrd image (PPBCOOT
5110 format!) to the "bootm" command:
5112 => imi 40100000 40200000
5114 ## Checking Image at 40100000 ...
5115 Image Name: 2.2.13 for initrd on TQM850L
5116 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5117 Data Size: 335725 Bytes = 327 kB = 0 MB
5118 Load Address: 00000000
5119 Entry Point: 0000000c
5120 Verifying Checksum ... OK
5122 ## Checking Image at 40200000 ...
5123 Image Name: Simple Ramdisk Image
5124 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5125 Data Size: 566530 Bytes = 553 kB = 0 MB
5126 Load Address: 00000000
5127 Entry Point: 00000000
5128 Verifying Checksum ... OK
5130 => bootm 40100000 40200000
5131 ## Booting Linux kernel at 40100000 ...
5132 Image Name: 2.2.13 for initrd on TQM850L
5133 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5134 Data Size: 335725 Bytes = 327 kB = 0 MB
5135 Load Address: 00000000
5136 Entry Point: 0000000c
5137 Verifying Checksum ... OK
5138 Uncompressing Kernel Image ... OK
5139 ## Loading RAMDisk Image at 40200000 ...
5140 Image Name: Simple Ramdisk Image
5141 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5142 Data Size: 566530 Bytes = 553 kB = 0 MB
5143 Load Address: 00000000
5144 Entry Point: 00000000
5145 Verifying Checksum ... OK
5146 Loading Ramdisk ... OK
5147 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
5148 Boot arguments: root=/dev/ram
5149 time_init: decrementer frequency = 187500000/60
5150 Calibrating delay loop... 49.77 BogoMIPS
5152 RAMDISK: Compressed image found at block 0
5153 VFS: Mounted root (ext2 filesystem).
5157 Boot Linux and pass a flat device tree:
5160 First, U-Boot must be compiled with the appropriate defines. See the section
5161 titled "Linux Kernel Interface" above for a more in depth explanation. The
5162 following is an example of how to start a kernel and pass an updated
5168 oft=oftrees/mpc8540ads.dtb
5169 => tftp $oftaddr $oft
5170 Speed: 1000, full duplex
5172 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5173 Filename 'oftrees/mpc8540ads.dtb'.
5174 Load address: 0x300000
5177 Bytes transferred = 4106 (100a hex)
5178 => tftp $loadaddr $bootfile
5179 Speed: 1000, full duplex
5181 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5183 Load address: 0x200000
5184 Loading:############
5186 Bytes transferred = 1029407 (fb51f hex)
5191 => bootm $loadaddr - $oftaddr
5192 ## Booting image at 00200000 ...
5193 Image Name: Linux-2.6.17-dirty
5194 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5195 Data Size: 1029343 Bytes = 1005.2 kB
5196 Load Address: 00000000
5197 Entry Point: 00000000
5198 Verifying Checksum ... OK
5199 Uncompressing Kernel Image ... OK
5200 Booting using flat device tree at 0x300000
5201 Using MPC85xx ADS machine description
5202 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5206 More About U-Boot Image Types:
5207 ------------------------------
5209 U-Boot supports the following image types:
5211 "Standalone Programs" are directly runnable in the environment
5212 provided by U-Boot; it is expected that (if they behave
5213 well) you can continue to work in U-Boot after return from
5214 the Standalone Program.
5215 "OS Kernel Images" are usually images of some Embedded OS which
5216 will take over control completely. Usually these programs
5217 will install their own set of exception handlers, device
5218 drivers, set up the MMU, etc. - this means, that you cannot
5219 expect to re-enter U-Boot except by resetting the CPU.
5220 "RAMDisk Images" are more or less just data blocks, and their
5221 parameters (address, size) are passed to an OS kernel that is
5223 "Multi-File Images" contain several images, typically an OS
5224 (Linux) kernel image and one or more data images like
5225 RAMDisks. This construct is useful for instance when you want
5226 to boot over the network using BOOTP etc., where the boot
5227 server provides just a single image file, but you want to get
5228 for instance an OS kernel and a RAMDisk image.
5230 "Multi-File Images" start with a list of image sizes, each
5231 image size (in bytes) specified by an "uint32_t" in network
5232 byte order. This list is terminated by an "(uint32_t)0".
5233 Immediately after the terminating 0 follow the images, one by
5234 one, all aligned on "uint32_t" boundaries (size rounded up to
5235 a multiple of 4 bytes).
5237 "Firmware Images" are binary images containing firmware (like
5238 U-Boot or FPGA images) which usually will be programmed to
5241 "Script files" are command sequences that will be executed by
5242 U-Boot's command interpreter; this feature is especially
5243 useful when you configure U-Boot to use a real shell (hush)
5244 as command interpreter.
5246 Booting the Linux zImage:
5247 -------------------------
5249 On some platforms, it's possible to boot Linux zImage. This is done
5250 using the "bootz" command. The syntax of "bootz" command is the same
5251 as the syntax of "bootm" command.
5253 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5254 kernel with raw initrd images. The syntax is slightly different, the
5255 address of the initrd must be augmented by it's size, in the following
5256 format: "<initrd addres>:<initrd size>".
5262 One of the features of U-Boot is that you can dynamically load and
5263 run "standalone" applications, which can use some resources of
5264 U-Boot like console I/O functions or interrupt services.
5266 Two simple examples are included with the sources:
5271 'examples/hello_world.c' contains a small "Hello World" Demo
5272 application; it is automatically compiled when you build U-Boot.
5273 It's configured to run at address 0x00040004, so you can play with it
5277 ## Ready for S-Record download ...
5278 ~>examples/hello_world.srec
5279 1 2 3 4 5 6 7 8 9 10 11 ...
5280 [file transfer complete]
5282 ## Start Addr = 0x00040004
5284 => go 40004 Hello World! This is a test.
5285 ## Starting application at 0x00040004 ...
5296 Hit any key to exit ...
5298 ## Application terminated, rc = 0x0
5300 Another example, which demonstrates how to register a CPM interrupt
5301 handler with the U-Boot code, can be found in 'examples/timer.c'.
5302 Here, a CPM timer is set up to generate an interrupt every second.
5303 The interrupt service routine is trivial, just printing a '.'
5304 character, but this is just a demo program. The application can be
5305 controlled by the following keys:
5307 ? - print current values og the CPM Timer registers
5308 b - enable interrupts and start timer
5309 e - stop timer and disable interrupts
5310 q - quit application
5313 ## Ready for S-Record download ...
5314 ~>examples/timer.srec
5315 1 2 3 4 5 6 7 8 9 10 11 ...
5316 [file transfer complete]
5318 ## Start Addr = 0x00040004
5321 ## Starting application at 0x00040004 ...
5324 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5327 [q, b, e, ?] Set interval 1000000 us
5330 [q, b, e, ?] ........
5331 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5334 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5337 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5340 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5342 [q, b, e, ?] ...Stopping timer
5344 [q, b, e, ?] ## Application terminated, rc = 0x0
5350 Over time, many people have reported problems when trying to use the
5351 "minicom" terminal emulation program for serial download. I (wd)
5352 consider minicom to be broken, and recommend not to use it. Under
5353 Unix, I recommend to use C-Kermit for general purpose use (and
5354 especially for kermit binary protocol download ("loadb" command), and
5355 use "cu" for S-Record download ("loads" command). See
5356 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5357 for help with kermit.
5360 Nevertheless, if you absolutely want to use it try adding this
5361 configuration to your "File transfer protocols" section:
5363 Name Program Name U/D FullScr IO-Red. Multi
5364 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5365 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5371 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5372 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5374 Building requires a cross environment; it is known to work on
5375 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5376 need gmake since the Makefiles are not compatible with BSD make).
5377 Note that the cross-powerpc package does not install include files;
5378 attempting to build U-Boot will fail because <machine/ansi.h> is
5379 missing. This file has to be installed and patched manually:
5381 # cd /usr/pkg/cross/powerpc-netbsd/include
5383 # ln -s powerpc machine
5384 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5385 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5387 Native builds *don't* work due to incompatibilities between native
5388 and U-Boot include files.
5390 Booting assumes that (the first part of) the image booted is a
5391 stage-2 loader which in turn loads and then invokes the kernel
5392 proper. Loader sources will eventually appear in the NetBSD source
5393 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5394 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5397 Implementation Internals:
5398 =========================
5400 The following is not intended to be a complete description of every
5401 implementation detail. However, it should help to understand the
5402 inner workings of U-Boot and make it easier to port it to custom
5406 Initial Stack, Global Data:
5407 ---------------------------
5409 The implementation of U-Boot is complicated by the fact that U-Boot
5410 starts running out of ROM (flash memory), usually without access to
5411 system RAM (because the memory controller is not initialized yet).
5412 This means that we don't have writable Data or BSS segments, and BSS
5413 is not initialized as zero. To be able to get a C environment working
5414 at all, we have to allocate at least a minimal stack. Implementation
5415 options for this are defined and restricted by the CPU used: Some CPU
5416 models provide on-chip memory (like the IMMR area on MPC8xx and
5417 MPC826x processors), on others (parts of) the data cache can be
5418 locked as (mis-) used as memory, etc.
5420 Chris Hallinan posted a good summary of these issues to the
5421 U-Boot mailing list:
5423 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5424 From: "Chris Hallinan" <clh@net1plus.com>
5425 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5428 Correct me if I'm wrong, folks, but the way I understand it
5429 is this: Using DCACHE as initial RAM for Stack, etc, does not
5430 require any physical RAM backing up the cache. The cleverness
5431 is that the cache is being used as a temporary supply of
5432 necessary storage before the SDRAM controller is setup. It's
5433 beyond the scope of this list to explain the details, but you
5434 can see how this works by studying the cache architecture and
5435 operation in the architecture and processor-specific manuals.
5437 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5438 is another option for the system designer to use as an
5439 initial stack/RAM area prior to SDRAM being available. Either
5440 option should work for you. Using CS 4 should be fine if your
5441 board designers haven't used it for something that would
5442 cause you grief during the initial boot! It is frequently not
5445 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5446 with your processor/board/system design. The default value
5447 you will find in any recent u-boot distribution in
5448 walnut.h should work for you. I'd set it to a value larger
5449 than your SDRAM module. If you have a 64MB SDRAM module, set
5450 it above 400_0000. Just make sure your board has no resources
5451 that are supposed to respond to that address! That code in
5452 start.S has been around a while and should work as is when
5453 you get the config right.
5458 It is essential to remember this, since it has some impact on the C
5459 code for the initialization procedures:
5461 * Initialized global data (data segment) is read-only. Do not attempt
5464 * Do not use any uninitialized global data (or implicitly initialized
5465 as zero data - BSS segment) at all - this is undefined, initiali-
5466 zation is performed later (when relocating to RAM).
5468 * Stack space is very limited. Avoid big data buffers or things like
5471 Having only the stack as writable memory limits means we cannot use
5472 normal global data to share information between the code. But it
5473 turned out that the implementation of U-Boot can be greatly
5474 simplified by making a global data structure (gd_t) available to all
5475 functions. We could pass a pointer to this data as argument to _all_
5476 functions, but this would bloat the code. Instead we use a feature of
5477 the GCC compiler (Global Register Variables) to share the data: we
5478 place a pointer (gd) to the global data into a register which we
5479 reserve for this purpose.
5481 When choosing a register for such a purpose we are restricted by the
5482 relevant (E)ABI specifications for the current architecture, and by
5483 GCC's implementation.
5485 For PowerPC, the following registers have specific use:
5487 R2: reserved for system use
5488 R3-R4: parameter passing and return values
5489 R5-R10: parameter passing
5490 R13: small data area pointer
5494 (U-Boot also uses R12 as internal GOT pointer. r12
5495 is a volatile register so r12 needs to be reset when
5496 going back and forth between asm and C)
5498 ==> U-Boot will use R2 to hold a pointer to the global data
5500 Note: on PPC, we could use a static initializer (since the
5501 address of the global data structure is known at compile time),
5502 but it turned out that reserving a register results in somewhat
5503 smaller code - although the code savings are not that big (on
5504 average for all boards 752 bytes for the whole U-Boot image,
5505 624 text + 127 data).
5507 On ARM, the following registers are used:
5509 R0: function argument word/integer result
5510 R1-R3: function argument word
5511 R9: platform specific
5512 R10: stack limit (used only if stack checking is enabled)
5513 R11: argument (frame) pointer
5514 R12: temporary workspace
5517 R15: program counter
5519 ==> U-Boot will use R9 to hold a pointer to the global data
5521 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5523 On Nios II, the ABI is documented here:
5524 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5526 ==> U-Boot will use gp to hold a pointer to the global data
5528 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5529 to access small data sections, so gp is free.
5531 On NDS32, the following registers are used:
5533 R0-R1: argument/return
5535 R15: temporary register for assembler
5536 R16: trampoline register
5537 R28: frame pointer (FP)
5538 R29: global pointer (GP)
5539 R30: link register (LP)
5540 R31: stack pointer (SP)
5541 PC: program counter (PC)
5543 ==> U-Boot will use R10 to hold a pointer to the global data
5545 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5546 or current versions of GCC may "optimize" the code too much.
5551 U-Boot runs in system state and uses physical addresses, i.e. the
5552 MMU is not used either for address mapping nor for memory protection.
5554 The available memory is mapped to fixed addresses using the memory
5555 controller. In this process, a contiguous block is formed for each
5556 memory type (Flash, SDRAM, SRAM), even when it consists of several
5557 physical memory banks.
5559 U-Boot is installed in the first 128 kB of the first Flash bank (on
5560 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5561 booting and sizing and initializing DRAM, the code relocates itself
5562 to the upper end of DRAM. Immediately below the U-Boot code some
5563 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5564 configuration setting]. Below that, a structure with global Board
5565 Info data is placed, followed by the stack (growing downward).
5567 Additionally, some exception handler code is copied to the low 8 kB
5568 of DRAM (0x00000000 ... 0x00001FFF).
5570 So a typical memory configuration with 16 MB of DRAM could look like
5573 0x0000 0000 Exception Vector code
5576 0x0000 2000 Free for Application Use
5582 0x00FB FF20 Monitor Stack (Growing downward)
5583 0x00FB FFAC Board Info Data and permanent copy of global data
5584 0x00FC 0000 Malloc Arena
5587 0x00FE 0000 RAM Copy of Monitor Code
5588 ... eventually: LCD or video framebuffer
5589 ... eventually: pRAM (Protected RAM - unchanged by reset)
5590 0x00FF FFFF [End of RAM]
5593 System Initialization:
5594 ----------------------
5596 In the reset configuration, U-Boot starts at the reset entry point
5597 (on most PowerPC systems at address 0x00000100). Because of the reset
5598 configuration for CS0# this is a mirror of the on board Flash memory.
5599 To be able to re-map memory U-Boot then jumps to its link address.
5600 To be able to implement the initialization code in C, a (small!)
5601 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5602 which provide such a feature like), or in a locked part of the data
5603 cache. After that, U-Boot initializes the CPU core, the caches and
5606 Next, all (potentially) available memory banks are mapped using a
5607 preliminary mapping. For example, we put them on 512 MB boundaries
5608 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5609 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5610 programmed for SDRAM access. Using the temporary configuration, a
5611 simple memory test is run that determines the size of the SDRAM
5614 When there is more than one SDRAM bank, and the banks are of
5615 different size, the largest is mapped first. For equal size, the first
5616 bank (CS2#) is mapped first. The first mapping is always for address
5617 0x00000000, with any additional banks following immediately to create
5618 contiguous memory starting from 0.
5620 Then, the monitor installs itself at the upper end of the SDRAM area
5621 and allocates memory for use by malloc() and for the global Board
5622 Info data; also, the exception vector code is copied to the low RAM
5623 pages, and the final stack is set up.
5625 Only after this relocation will you have a "normal" C environment;
5626 until that you are restricted in several ways, mostly because you are
5627 running from ROM, and because the code will have to be relocated to a
5631 U-Boot Porting Guide:
5632 ----------------------
5634 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5638 int main(int argc, char *argv[])
5640 sighandler_t no_more_time;
5642 signal(SIGALRM, no_more_time);
5643 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5645 if (available_money > available_manpower) {
5646 Pay consultant to port U-Boot;
5650 Download latest U-Boot source;
5652 Subscribe to u-boot mailing list;
5655 email("Hi, I am new to U-Boot, how do I get started?");
5658 Read the README file in the top level directory;
5659 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5660 Read applicable doc/*.README;
5661 Read the source, Luke;
5662 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5665 if (available_money > toLocalCurrency ($2500))
5668 Add a lot of aggravation and time;
5670 if (a similar board exists) { /* hopefully... */
5671 cp -a board/<similar> board/<myboard>
5672 cp include/configs/<similar>.h include/configs/<myboard>.h
5674 Create your own board support subdirectory;
5675 Create your own board include/configs/<myboard>.h file;
5677 Edit new board/<myboard> files
5678 Edit new include/configs/<myboard>.h
5683 Add / modify source code;
5687 email("Hi, I am having problems...");
5689 Send patch file to the U-Boot email list;
5690 if (reasonable critiques)
5691 Incorporate improvements from email list code review;
5693 Defend code as written;
5699 void no_more_time (int sig)
5708 All contributions to U-Boot should conform to the Linux kernel
5709 coding style; see the file "Documentation/CodingStyle" and the script
5710 "scripts/Lindent" in your Linux kernel source directory.
5712 Source files originating from a different project (for example the
5713 MTD subsystem) are generally exempt from these guidelines and are not
5714 reformatted to ease subsequent migration to newer versions of those
5717 Please note that U-Boot is implemented in C (and to some small parts in
5718 Assembler); no C++ is used, so please do not use C++ style comments (//)
5721 Please also stick to the following formatting rules:
5722 - remove any trailing white space
5723 - use TAB characters for indentation and vertical alignment, not spaces
5724 - make sure NOT to use DOS '\r\n' line feeds
5725 - do not add more than 2 consecutive empty lines to source files
5726 - do not add trailing empty lines to source files
5728 Submissions which do not conform to the standards may be returned
5729 with a request to reformat the changes.
5735 Since the number of patches for U-Boot is growing, we need to
5736 establish some rules. Submissions which do not conform to these rules
5737 may be rejected, even when they contain important and valuable stuff.
5739 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5741 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5742 see http://lists.denx.de/mailman/listinfo/u-boot
5744 When you send a patch, please include the following information with
5747 * For bug fixes: a description of the bug and how your patch fixes
5748 this bug. Please try to include a way of demonstrating that the
5749 patch actually fixes something.
5751 * For new features: a description of the feature and your
5754 * A CHANGELOG entry as plaintext (separate from the patch)
5756 * For major contributions, add a MAINTAINERS file with your
5757 information and associated file and directory references.
5759 * When you add support for a new board, don't forget to add a
5760 maintainer e-mail address to the boards.cfg file, too.
5762 * If your patch adds new configuration options, don't forget to
5763 document these in the README file.
5765 * The patch itself. If you are using git (which is *strongly*
5766 recommended) you can easily generate the patch using the
5767 "git format-patch". If you then use "git send-email" to send it to
5768 the U-Boot mailing list, you will avoid most of the common problems
5769 with some other mail clients.
5771 If you cannot use git, use "diff -purN OLD NEW". If your version of
5772 diff does not support these options, then get the latest version of
5775 The current directory when running this command shall be the parent
5776 directory of the U-Boot source tree (i. e. please make sure that
5777 your patch includes sufficient directory information for the
5780 We prefer patches as plain text. MIME attachments are discouraged,
5781 and compressed attachments must not be used.
5783 * If one logical set of modifications affects or creates several
5784 files, all these changes shall be submitted in a SINGLE patch file.
5786 * Changesets that contain different, unrelated modifications shall be
5787 submitted as SEPARATE patches, one patch per changeset.
5792 * Before sending the patch, run the buildman script on your patched
5793 source tree and make sure that no errors or warnings are reported
5794 for any of the boards.
5796 * Keep your modifications to the necessary minimum: A patch
5797 containing several unrelated changes or arbitrary reformats will be
5798 returned with a request to re-formatting / split it.
5800 * If you modify existing code, make sure that your new code does not
5801 add to the memory footprint of the code ;-) Small is beautiful!
5802 When adding new features, these should compile conditionally only
5803 (using #ifdef), and the resulting code with the new feature
5804 disabled must not need more memory than the old code without your
5807 * Remember that there is a size limit of 100 kB per message on the
5808 u-boot mailing list. Bigger patches will be moderated. If they are
5809 reasonable and not too big, they will be acknowledged. But patches
5810 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob