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 8xx (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. For the 8xx
923 CPUs, the SIU Watchdog feature is enabled in the SYPCR
924 register. When supported for a specific SoC is
925 available, then no further board specific code should
929 When using a watchdog circuitry external to the used
930 SoC, then define this variable and provide board
931 specific code for the "hw_watchdog_reset" function.
933 CONFIG_AT91_HW_WDT_TIMEOUT
934 specify the timeout in seconds. default 2 seconds.
937 CONFIG_VERSION_VARIABLE
938 If this variable is defined, an environment variable
939 named "ver" is created by U-Boot showing the U-Boot
940 version as printed by the "version" command.
941 Any change to this variable will be reverted at the
946 When CONFIG_CMD_DATE is selected, the type of the RTC
947 has to be selected, too. Define exactly one of the
950 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
951 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
952 CONFIG_RTC_MC146818 - use MC146818 RTC
953 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
954 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
955 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
956 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
957 CONFIG_RTC_DS164x - use Dallas DS164x RTC
958 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
959 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
960 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
961 CONFIG_SYS_RV3029_TCR - enable trickle charger on
964 Note that if the RTC uses I2C, then the I2C interface
965 must also be configured. See I2C Support, below.
968 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
970 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
971 chip-ngpio pairs that tell the PCA953X driver the number of
972 pins supported by a particular chip.
974 Note that if the GPIO device uses I2C, then the I2C interface
975 must also be configured. See I2C Support, below.
978 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
979 accesses and can checksum them or write a list of them out
980 to memory. See the 'iotrace' command for details. This is
981 useful for testing device drivers since it can confirm that
982 the driver behaves the same way before and after a code
983 change. Currently this is supported on sandbox and arm. To
984 add support for your architecture, add '#include <iotrace.h>'
985 to the bottom of arch/<arch>/include/asm/io.h and test.
987 Example output from the 'iotrace stats' command is below.
988 Note that if the trace buffer is exhausted, the checksum will
989 still continue to operate.
992 Start: 10000000 (buffer start address)
993 Size: 00010000 (buffer size)
994 Offset: 00000120 (current buffer offset)
995 Output: 10000120 (start + offset)
996 Count: 00000018 (number of trace records)
997 CRC32: 9526fb66 (CRC32 of all trace records)
1001 When CONFIG_TIMESTAMP is selected, the timestamp
1002 (date and time) of an image is printed by image
1003 commands like bootm or iminfo. This option is
1004 automatically enabled when you select CONFIG_CMD_DATE .
1006 - Partition Labels (disklabels) Supported:
1007 Zero or more of the following:
1008 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1009 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1010 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1011 bootloader. Note 2TB partition limit; see
1013 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1015 If IDE or SCSI support is enabled (CONFIG_IDE or
1016 CONFIG_SCSI) you must configure support for at
1017 least one non-MTD partition type as well.
1020 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1021 board configurations files but used nowhere!
1023 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1024 be performed by calling the function
1025 ide_set_reset(int reset)
1026 which has to be defined in a board specific file
1031 Set this to enable ATAPI support.
1036 Set this to enable support for disks larger than 137GB
1037 Also look at CONFIG_SYS_64BIT_LBA.
1038 Whithout these , LBA48 support uses 32bit variables and will 'only'
1039 support disks up to 2.1TB.
1041 CONFIG_SYS_64BIT_LBA:
1042 When enabled, makes the IDE subsystem use 64bit sector addresses.
1046 At the moment only there is only support for the
1047 SYM53C8XX SCSI controller; define
1048 CONFIG_SCSI_SYM53C8XX to enable it.
1050 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1051 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1052 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1053 maximum numbers of LUNs, SCSI ID's and target
1055 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1057 The environment variable 'scsidevs' is set to the number of
1058 SCSI devices found during the last scan.
1060 - NETWORK Support (PCI):
1062 Support for Intel 8254x/8257x gigabit chips.
1065 Utility code for direct access to the SPI bus on Intel 8257x.
1066 This does not do anything useful unless you set at least one
1067 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1069 CONFIG_E1000_SPI_GENERIC
1070 Allow generic access to the SPI bus on the Intel 8257x, for
1071 example with the "sspi" command.
1074 Management command for E1000 devices. When used on devices
1075 with SPI support you can reprogram the EEPROM from U-Boot.
1078 Support for Intel 82557/82559/82559ER chips.
1079 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1080 write routine for first time initialisation.
1083 Support for Digital 2114x chips.
1084 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1085 modem chip initialisation (KS8761/QS6611).
1088 Support for National dp83815 chips.
1091 Support for National dp8382[01] gigabit chips.
1093 - NETWORK Support (other):
1095 CONFIG_DRIVER_AT91EMAC
1096 Support for AT91RM9200 EMAC.
1099 Define this to use reduced MII inteface
1101 CONFIG_DRIVER_AT91EMAC_QUIET
1102 If this defined, the driver is quiet.
1103 The driver doen't show link status messages.
1105 CONFIG_CALXEDA_XGMAC
1106 Support for the Calxeda XGMAC device
1109 Support for SMSC's LAN91C96 chips.
1111 CONFIG_LAN91C96_USE_32_BIT
1112 Define this to enable 32 bit addressing
1115 Support for SMSC's LAN91C111 chip
1117 CONFIG_SMC91111_BASE
1118 Define this to hold the physical address
1119 of the device (I/O space)
1121 CONFIG_SMC_USE_32_BIT
1122 Define this if data bus is 32 bits
1124 CONFIG_SMC_USE_IOFUNCS
1125 Define this to use i/o functions instead of macros
1126 (some hardware wont work with macros)
1128 CONFIG_DRIVER_TI_EMAC
1129 Support for davinci emac
1131 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1132 Define this if you have more then 3 PHYs.
1135 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1137 CONFIG_FTGMAC100_EGIGA
1138 Define this to use GE link update with gigabit PHY.
1139 Define this if FTGMAC100 is connected to gigabit PHY.
1140 If your system has 10/100 PHY only, it might not occur
1141 wrong behavior. Because PHY usually return timeout or
1142 useless data when polling gigabit status and gigabit
1143 control registers. This behavior won't affect the
1144 correctnessof 10/100 link speed update.
1147 Support for SMSC's LAN911x and LAN921x chips
1150 Define this to hold the physical address
1151 of the device (I/O space)
1153 CONFIG_SMC911X_32_BIT
1154 Define this if data bus is 32 bits
1156 CONFIG_SMC911X_16_BIT
1157 Define this if data bus is 16 bits. If your processor
1158 automatically converts one 32 bit word to two 16 bit
1159 words you may also try CONFIG_SMC911X_32_BIT.
1162 Support for Renesas on-chip Ethernet controller
1164 CONFIG_SH_ETHER_USE_PORT
1165 Define the number of ports to be used
1167 CONFIG_SH_ETHER_PHY_ADDR
1168 Define the ETH PHY's address
1170 CONFIG_SH_ETHER_CACHE_WRITEBACK
1171 If this option is set, the driver enables cache flush.
1175 Support for PWM module on the imx6.
1179 Support TPM devices.
1181 CONFIG_TPM_TIS_INFINEON
1182 Support for Infineon i2c bus TPM devices. Only one device
1183 per system is supported at this time.
1185 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1186 Define the burst count bytes upper limit
1189 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1191 CONFIG_TPM_ST33ZP24_I2C
1192 Support for STMicroelectronics ST33ZP24 I2C devices.
1193 Requires TPM_ST33ZP24 and I2C.
1195 CONFIG_TPM_ST33ZP24_SPI
1196 Support for STMicroelectronics ST33ZP24 SPI devices.
1197 Requires TPM_ST33ZP24 and SPI.
1199 CONFIG_TPM_ATMEL_TWI
1200 Support for Atmel TWI TPM device. Requires I2C support.
1203 Support for generic parallel port TPM devices. Only one device
1204 per system is supported at this time.
1206 CONFIG_TPM_TIS_BASE_ADDRESS
1207 Base address where the generic TPM device is mapped
1208 to. Contemporary x86 systems usually map it at
1212 Add tpm monitor functions.
1213 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1214 provides monitor access to authorized functions.
1217 Define this to enable the TPM support library which provides
1218 functional interfaces to some TPM commands.
1219 Requires support for a TPM device.
1221 CONFIG_TPM_AUTH_SESSIONS
1222 Define this to enable authorized functions in the TPM library.
1223 Requires CONFIG_TPM and CONFIG_SHA1.
1226 At the moment only the UHCI host controller is
1227 supported (PIP405, MIP405); define
1228 CONFIG_USB_UHCI to enable it.
1229 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1230 and define CONFIG_USB_STORAGE to enable the USB
1233 Supported are USB Keyboards and USB Floppy drives
1236 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1237 txfilltuning field in the EHCI controller on reset.
1239 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1240 HW module registers.
1243 Define the below if you wish to use the USB console.
1244 Once firmware is rebuilt from a serial console issue the
1245 command "setenv stdin usbtty; setenv stdout usbtty" and
1246 attach your USB cable. The Unix command "dmesg" should print
1247 it has found a new device. The environment variable usbtty
1248 can be set to gserial or cdc_acm to enable your device to
1249 appear to a USB host as a Linux gserial device or a
1250 Common Device Class Abstract Control Model serial device.
1251 If you select usbtty = gserial you should be able to enumerate
1253 # modprobe usbserial vendor=0xVendorID product=0xProductID
1254 else if using cdc_acm, simply setting the environment
1255 variable usbtty to be cdc_acm should suffice. The following
1256 might be defined in YourBoardName.h
1259 Define this to build a UDC device
1262 Define this to have a tty type of device available to
1263 talk to the UDC device
1266 Define this to enable the high speed support for usb
1267 device and usbtty. If this feature is enabled, a routine
1268 int is_usbd_high_speed(void)
1269 also needs to be defined by the driver to dynamically poll
1270 whether the enumeration has succeded at high speed or full
1273 CONFIG_SYS_CONSOLE_IS_IN_ENV
1274 Define this if you want stdin, stdout &/or stderr to
1277 If you have a USB-IF assigned VendorID then you may wish to
1278 define your own vendor specific values either in BoardName.h
1279 or directly in usbd_vendor_info.h. If you don't define
1280 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1281 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1282 should pretend to be a Linux device to it's target host.
1284 CONFIG_USBD_MANUFACTURER
1285 Define this string as the name of your company for
1286 - CONFIG_USBD_MANUFACTURER "my company"
1288 CONFIG_USBD_PRODUCT_NAME
1289 Define this string as the name of your product
1290 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1292 CONFIG_USBD_VENDORID
1293 Define this as your assigned Vendor ID from the USB
1294 Implementors Forum. This *must* be a genuine Vendor ID
1295 to avoid polluting the USB namespace.
1296 - CONFIG_USBD_VENDORID 0xFFFF
1298 CONFIG_USBD_PRODUCTID
1299 Define this as the unique Product ID
1301 - CONFIG_USBD_PRODUCTID 0xFFFF
1303 - ULPI Layer Support:
1304 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1305 the generic ULPI layer. The generic layer accesses the ULPI PHY
1306 via the platform viewport, so you need both the genric layer and
1307 the viewport enabled. Currently only Chipidea/ARC based
1308 viewport is supported.
1309 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1310 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1311 If your ULPI phy needs a different reference clock than the
1312 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1313 the appropriate value in Hz.
1316 The MMC controller on the Intel PXA is supported. To
1317 enable this define CONFIG_MMC. The MMC can be
1318 accessed from the boot prompt by mapping the device
1319 to physical memory similar to flash. Command line is
1320 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1321 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1324 Support for Renesas on-chip MMCIF controller
1326 CONFIG_SH_MMCIF_ADDR
1327 Define the base address of MMCIF registers
1330 Define the clock frequency for MMCIF
1332 CONFIG_SUPPORT_EMMC_BOOT
1333 Enable some additional features of the eMMC boot partitions.
1335 CONFIG_SUPPORT_EMMC_RPMB
1336 Enable the commands for reading, writing and programming the
1337 key for the Replay Protection Memory Block partition in eMMC.
1339 - USB Device Firmware Update (DFU) class support:
1340 CONFIG_USB_FUNCTION_DFU
1341 This enables the USB portion of the DFU USB class
1344 This enables the command "dfu" which is used to have
1345 U-Boot create a DFU class device via USB. This command
1346 requires that the "dfu_alt_info" environment variable be
1347 set and define the alt settings to expose to the host.
1350 This enables support for exposing (e)MMC devices via DFU.
1353 This enables support for exposing NAND devices via DFU.
1356 This enables support for exposing RAM via DFU.
1357 Note: DFU spec refer to non-volatile memory usage, but
1358 allow usages beyond the scope of spec - here RAM usage,
1359 one that would help mostly the developer.
1361 CONFIG_SYS_DFU_DATA_BUF_SIZE
1362 Dfu transfer uses a buffer before writing data to the
1363 raw storage device. Make the size (in bytes) of this buffer
1364 configurable. The size of this buffer is also configurable
1365 through the "dfu_bufsiz" environment variable.
1367 CONFIG_SYS_DFU_MAX_FILE_SIZE
1368 When updating files rather than the raw storage device,
1369 we use a static buffer to copy the file into and then write
1370 the buffer once we've been given the whole file. Define
1371 this to the maximum filesize (in bytes) for the buffer.
1372 Default is 4 MiB if undefined.
1374 DFU_DEFAULT_POLL_TIMEOUT
1375 Poll timeout [ms], is the timeout a device can send to the
1376 host. The host must wait for this timeout before sending
1377 a subsequent DFU_GET_STATUS request to the device.
1379 DFU_MANIFEST_POLL_TIMEOUT
1380 Poll timeout [ms], which the device sends to the host when
1381 entering dfuMANIFEST state. Host waits this timeout, before
1382 sending again an USB request to the device.
1384 - USB Device Android Fastboot support:
1385 CONFIG_USB_FUNCTION_FASTBOOT
1386 This enables the USB part of the fastboot gadget
1389 This enables the command "fastboot" which enables the Android
1390 fastboot mode for the platform's USB device. Fastboot is a USB
1391 protocol for downloading images, flashing and device control
1392 used on Android devices.
1393 See doc/README.android-fastboot for more information.
1395 CONFIG_ANDROID_BOOT_IMAGE
1396 This enables support for booting images which use the Android
1397 image format header.
1399 CONFIG_FASTBOOT_BUF_ADDR
1400 The fastboot protocol requires a large memory buffer for
1401 downloads. Define this to the starting RAM address to use for
1404 CONFIG_FASTBOOT_BUF_SIZE
1405 The fastboot protocol requires a large memory buffer for
1406 downloads. This buffer should be as large as possible for a
1407 platform. Define this to the size available RAM for fastboot.
1409 CONFIG_FASTBOOT_FLASH
1410 The fastboot protocol includes a "flash" command for writing
1411 the downloaded image to a non-volatile storage device. Define
1412 this to enable the "fastboot flash" command.
1414 CONFIG_FASTBOOT_FLASH_MMC_DEV
1415 The fastboot "flash" command requires additional information
1416 regarding the non-volatile storage device. Define this to
1417 the eMMC device that fastboot should use to store the image.
1419 CONFIG_FASTBOOT_GPT_NAME
1420 The fastboot "flash" command supports writing the downloaded
1421 image to the Protective MBR and the Primary GUID Partition
1422 Table. (Additionally, this downloaded image is post-processed
1423 to generate and write the Backup GUID Partition Table.)
1424 This occurs when the specified "partition name" on the
1425 "fastboot flash" command line matches this value.
1426 The default is "gpt" if undefined.
1428 CONFIG_FASTBOOT_MBR_NAME
1429 The fastboot "flash" command supports writing the downloaded
1431 This occurs when the "partition name" specified on the
1432 "fastboot flash" command line matches this value.
1433 If not defined the default value "mbr" is used.
1435 - Journaling Flash filesystem support:
1437 Define these for a default partition on a NAND device
1439 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1440 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1441 Define these for a default partition on a NOR device
1444 See Kconfig help for available keyboard drivers.
1448 Define this to enable a custom keyboard support.
1449 This simply calls drv_keyboard_init() which must be
1450 defined in your board-specific files. This option is deprecated
1451 and is only used by novena. For new boards, use driver model
1456 Enable the Freescale DIU video driver. Reference boards for
1457 SOCs that have a DIU should define this macro to enable DIU
1458 support, and should also define these other macros:
1463 CONFIG_VIDEO_SW_CURSOR
1464 CONFIG_VGA_AS_SINGLE_DEVICE
1466 CONFIG_VIDEO_BMP_LOGO
1468 The DIU driver will look for the 'video-mode' environment
1469 variable, and if defined, enable the DIU as a console during
1470 boot. See the documentation file doc/README.video for a
1471 description of this variable.
1473 - LCD Support: CONFIG_LCD
1475 Define this to enable LCD support (for output to LCD
1476 display); also select one of the supported displays
1477 by defining one of these:
1481 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1483 CONFIG_NEC_NL6448AC33:
1485 NEC NL6448AC33-18. Active, color, single scan.
1487 CONFIG_NEC_NL6448BC20
1489 NEC NL6448BC20-08. 6.5", 640x480.
1490 Active, color, single scan.
1492 CONFIG_NEC_NL6448BC33_54
1494 NEC NL6448BC33-54. 10.4", 640x480.
1495 Active, color, single scan.
1499 Sharp 320x240. Active, color, single scan.
1500 It isn't 16x9, and I am not sure what it is.
1502 CONFIG_SHARP_LQ64D341
1504 Sharp LQ64D341 display, 640x480.
1505 Active, color, single scan.
1509 HLD1045 display, 640x480.
1510 Active, color, single scan.
1514 Optrex CBL50840-2 NF-FW 99 22 M5
1516 Hitachi LMG6912RPFC-00T
1520 320x240. Black & white.
1522 CONFIG_LCD_ALIGNMENT
1524 Normally the LCD is page-aligned (typically 4KB). If this is
1525 defined then the LCD will be aligned to this value instead.
1526 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1527 here, since it is cheaper to change data cache settings on
1528 a per-section basis.
1533 Sometimes, for example if the display is mounted in portrait
1534 mode or even if it's mounted landscape but rotated by 180degree,
1535 we need to rotate our content of the display relative to the
1536 framebuffer, so that user can read the messages which are
1538 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1539 initialized with a given rotation from "vl_rot" out of
1540 "vidinfo_t" which is provided by the board specific code.
1541 The value for vl_rot is coded as following (matching to
1542 fbcon=rotate:<n> linux-kernel commandline):
1543 0 = no rotation respectively 0 degree
1544 1 = 90 degree rotation
1545 2 = 180 degree rotation
1546 3 = 270 degree rotation
1548 If CONFIG_LCD_ROTATION is not defined, the console will be
1549 initialized with 0degree rotation.
1553 Support drawing of RLE8-compressed bitmaps on the LCD.
1557 Enables an 'i2c edid' command which can read EDID
1558 information over I2C from an attached LCD display.
1560 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1562 If this option is set, the environment is checked for
1563 a variable "splashimage". If found, the usual display
1564 of logo, copyright and system information on the LCD
1565 is suppressed and the BMP image at the address
1566 specified in "splashimage" is loaded instead. The
1567 console is redirected to the "nulldev", too. This
1568 allows for a "silent" boot where a splash screen is
1569 loaded very quickly after power-on.
1571 CONFIG_SPLASHIMAGE_GUARD
1573 If this option is set, then U-Boot will prevent the environment
1574 variable "splashimage" from being set to a problematic address
1575 (see doc/README.displaying-bmps).
1576 This option is useful for targets where, due to alignment
1577 restrictions, an improperly aligned BMP image will cause a data
1578 abort. If you think you will not have problems with unaligned
1579 accesses (for example because your toolchain prevents them)
1580 there is no need to set this option.
1582 CONFIG_SPLASH_SCREEN_ALIGN
1584 If this option is set the splash image can be freely positioned
1585 on the screen. Environment variable "splashpos" specifies the
1586 position as "x,y". If a positive number is given it is used as
1587 number of pixel from left/top. If a negative number is given it
1588 is used as number of pixel from right/bottom. You can also
1589 specify 'm' for centering the image.
1592 setenv splashpos m,m
1593 => image at center of screen
1595 setenv splashpos 30,20
1596 => image at x = 30 and y = 20
1598 setenv splashpos -10,m
1599 => vertically centered image
1600 at x = dspWidth - bmpWidth - 9
1602 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1604 If this option is set, additionally to standard BMP
1605 images, gzipped BMP images can be displayed via the
1606 splashscreen support or the bmp command.
1608 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1610 If this option is set, 8-bit RLE compressed BMP images
1611 can be displayed via the splashscreen support or the
1614 - Compression support:
1617 Enabled by default to support gzip compressed images.
1621 If this option is set, support for bzip2 compressed
1622 images is included. If not, only uncompressed and gzip
1623 compressed images are supported.
1625 NOTE: the bzip2 algorithm requires a lot of RAM, so
1626 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1631 If this option is set, support for LZO compressed images
1637 The address of PHY on MII bus.
1639 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1641 The clock frequency of the MII bus
1645 If this option is set, support for speed/duplex
1646 detection of gigabit PHY is included.
1648 CONFIG_PHY_RESET_DELAY
1650 Some PHY like Intel LXT971A need extra delay after
1651 reset before any MII register access is possible.
1652 For such PHY, set this option to the usec delay
1653 required. (minimum 300usec for LXT971A)
1655 CONFIG_PHY_CMD_DELAY (ppc4xx)
1657 Some PHY like Intel LXT971A need extra delay after
1658 command issued before MII status register can be read
1663 Define a default value for the IP address to use for
1664 the default Ethernet interface, in case this is not
1665 determined through e.g. bootp.
1666 (Environment variable "ipaddr")
1668 - Server IP address:
1671 Defines a default value for the IP address of a TFTP
1672 server to contact when using the "tftboot" command.
1673 (Environment variable "serverip")
1675 CONFIG_KEEP_SERVERADDR
1677 Keeps the server's MAC address, in the env 'serveraddr'
1678 for passing to bootargs (like Linux's netconsole option)
1680 - Gateway IP address:
1683 Defines a default value for the IP address of the
1684 default router where packets to other networks are
1686 (Environment variable "gatewayip")
1691 Defines a default value for the subnet mask (or
1692 routing prefix) which is used to determine if an IP
1693 address belongs to the local subnet or needs to be
1694 forwarded through a router.
1695 (Environment variable "netmask")
1697 - Multicast TFTP Mode:
1700 Defines whether you want to support multicast TFTP as per
1701 rfc-2090; for example to work with atftp. Lets lots of targets
1702 tftp down the same boot image concurrently. Note: the Ethernet
1703 driver in use must provide a function: mcast() to join/leave a
1706 - BOOTP Recovery Mode:
1707 CONFIG_BOOTP_RANDOM_DELAY
1709 If you have many targets in a network that try to
1710 boot using BOOTP, you may want to avoid that all
1711 systems send out BOOTP requests at precisely the same
1712 moment (which would happen for instance at recovery
1713 from a power failure, when all systems will try to
1714 boot, thus flooding the BOOTP server. Defining
1715 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1716 inserted before sending out BOOTP requests. The
1717 following delays are inserted then:
1719 1st BOOTP request: delay 0 ... 1 sec
1720 2nd BOOTP request: delay 0 ... 2 sec
1721 3rd BOOTP request: delay 0 ... 4 sec
1723 BOOTP requests: delay 0 ... 8 sec
1725 CONFIG_BOOTP_ID_CACHE_SIZE
1727 BOOTP packets are uniquely identified using a 32-bit ID. The
1728 server will copy the ID from client requests to responses and
1729 U-Boot will use this to determine if it is the destination of
1730 an incoming response. Some servers will check that addresses
1731 aren't in use before handing them out (usually using an ARP
1732 ping) and therefore take up to a few hundred milliseconds to
1733 respond. Network congestion may also influence the time it
1734 takes for a response to make it back to the client. If that
1735 time is too long, U-Boot will retransmit requests. In order
1736 to allow earlier responses to still be accepted after these
1737 retransmissions, U-Boot's BOOTP client keeps a small cache of
1738 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1739 cache. The default is to keep IDs for up to four outstanding
1740 requests. Increasing this will allow U-Boot to accept offers
1741 from a BOOTP client in networks with unusually high latency.
1743 - DHCP Advanced Options:
1744 You can fine tune the DHCP functionality by defining
1745 CONFIG_BOOTP_* symbols:
1747 CONFIG_BOOTP_SUBNETMASK
1748 CONFIG_BOOTP_GATEWAY
1749 CONFIG_BOOTP_HOSTNAME
1750 CONFIG_BOOTP_NISDOMAIN
1751 CONFIG_BOOTP_BOOTPATH
1752 CONFIG_BOOTP_BOOTFILESIZE
1755 CONFIG_BOOTP_SEND_HOSTNAME
1756 CONFIG_BOOTP_NTPSERVER
1757 CONFIG_BOOTP_TIMEOFFSET
1758 CONFIG_BOOTP_VENDOREX
1759 CONFIG_BOOTP_MAY_FAIL
1761 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1762 environment variable, not the BOOTP server.
1764 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1765 after the configured retry count, the call will fail
1766 instead of starting over. This can be used to fail over
1767 to Link-local IP address configuration if the DHCP server
1770 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1771 serverip from a DHCP server, it is possible that more
1772 than one DNS serverip is offered to the client.
1773 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1774 serverip will be stored in the additional environment
1775 variable "dnsip2". The first DNS serverip is always
1776 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1779 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1780 to do a dynamic update of a DNS server. To do this, they
1781 need the hostname of the DHCP requester.
1782 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1783 of the "hostname" environment variable is passed as
1784 option 12 to the DHCP server.
1786 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1788 A 32bit value in microseconds for a delay between
1789 receiving a "DHCP Offer" and sending the "DHCP Request".
1790 This fixes a problem with certain DHCP servers that don't
1791 respond 100% of the time to a "DHCP request". E.g. On an
1792 AT91RM9200 processor running at 180MHz, this delay needed
1793 to be *at least* 15,000 usec before a Windows Server 2003
1794 DHCP server would reply 100% of the time. I recommend at
1795 least 50,000 usec to be safe. The alternative is to hope
1796 that one of the retries will be successful but note that
1797 the DHCP timeout and retry process takes a longer than
1800 - Link-local IP address negotiation:
1801 Negotiate with other link-local clients on the local network
1802 for an address that doesn't require explicit configuration.
1803 This is especially useful if a DHCP server cannot be guaranteed
1804 to exist in all environments that the device must operate.
1806 See doc/README.link-local for more information.
1809 CONFIG_CDP_DEVICE_ID
1811 The device id used in CDP trigger frames.
1813 CONFIG_CDP_DEVICE_ID_PREFIX
1815 A two character string which is prefixed to the MAC address
1820 A printf format string which contains the ascii name of
1821 the port. Normally is set to "eth%d" which sets
1822 eth0 for the first Ethernet, eth1 for the second etc.
1824 CONFIG_CDP_CAPABILITIES
1826 A 32bit integer which indicates the device capabilities;
1827 0x00000010 for a normal host which does not forwards.
1831 An ascii string containing the version of the software.
1835 An ascii string containing the name of the platform.
1839 A 32bit integer sent on the trigger.
1841 CONFIG_CDP_POWER_CONSUMPTION
1843 A 16bit integer containing the power consumption of the
1844 device in .1 of milliwatts.
1846 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1848 A byte containing the id of the VLAN.
1850 - Status LED: CONFIG_LED_STATUS
1852 Several configurations allow to display the current
1853 status using a LED. For instance, the LED will blink
1854 fast while running U-Boot code, stop blinking as
1855 soon as a reply to a BOOTP request was received, and
1856 start blinking slow once the Linux kernel is running
1857 (supported by a status LED driver in the Linux
1858 kernel). Defining CONFIG_LED_STATUS enables this
1863 CONFIG_LED_STATUS_GPIO
1864 The status LED can be connected to a GPIO pin.
1865 In such cases, the gpio_led driver can be used as a
1866 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1867 to include the gpio_led driver in the U-Boot binary.
1869 CONFIG_GPIO_LED_INVERTED_TABLE
1870 Some GPIO connected LEDs may have inverted polarity in which
1871 case the GPIO high value corresponds to LED off state and
1872 GPIO low value corresponds to LED on state.
1873 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1874 with a list of GPIO LEDs that have inverted polarity.
1876 - I2C Support: CONFIG_SYS_I2C
1878 This enable the NEW i2c subsystem, and will allow you to use
1879 i2c commands at the u-boot command line (as long as you set
1880 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1881 based realtime clock chips or other i2c devices. See
1882 common/cmd_i2c.c for a description of the command line
1885 ported i2c driver to the new framework:
1886 - drivers/i2c/soft_i2c.c:
1887 - activate first bus with CONFIG_SYS_I2C_SOFT define
1888 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1889 for defining speed and slave address
1890 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1891 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1892 for defining speed and slave address
1893 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1894 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1895 for defining speed and slave address
1896 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1897 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1898 for defining speed and slave address
1900 - drivers/i2c/fsl_i2c.c:
1901 - activate i2c driver with CONFIG_SYS_I2C_FSL
1902 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1903 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1904 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1906 - If your board supports a second fsl i2c bus, define
1907 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1908 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1909 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1912 - drivers/i2c/tegra_i2c.c:
1913 - activate this driver with CONFIG_SYS_I2C_TEGRA
1914 - This driver adds 4 i2c buses with a fix speed from
1915 100000 and the slave addr 0!
1917 - drivers/i2c/ppc4xx_i2c.c
1918 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1919 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1920 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1922 - drivers/i2c/i2c_mxc.c
1923 - activate this driver with CONFIG_SYS_I2C_MXC
1924 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1925 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1926 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1927 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1928 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1929 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1930 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1931 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1932 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1933 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1934 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1935 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1936 If those defines are not set, default value is 100000
1937 for speed, and 0 for slave.
1939 - drivers/i2c/rcar_i2c.c:
1940 - activate this driver with CONFIG_SYS_I2C_RCAR
1941 - This driver adds 4 i2c buses
1943 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1944 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1945 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1946 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1947 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1948 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1949 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1950 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1951 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1953 - drivers/i2c/sh_i2c.c:
1954 - activate this driver with CONFIG_SYS_I2C_SH
1955 - This driver adds from 2 to 5 i2c buses
1957 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1958 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1959 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1960 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1961 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1962 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1963 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1964 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1965 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1966 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1967 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1969 - drivers/i2c/omap24xx_i2c.c
1970 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1971 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1972 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1973 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1974 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1975 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1976 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1977 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1978 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1979 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1980 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1982 - drivers/i2c/zynq_i2c.c
1983 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1984 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1985 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1987 - drivers/i2c/s3c24x0_i2c.c:
1988 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1989 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1990 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1991 with a fix speed from 100000 and the slave addr 0!
1993 - drivers/i2c/ihs_i2c.c
1994 - activate this driver with CONFIG_SYS_I2C_IHS
1995 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1996 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1997 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1998 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1999 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2000 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2001 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2002 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2003 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2004 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2005 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2006 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2007 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2008 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2009 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2010 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2011 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2012 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2013 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2014 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2015 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2019 CONFIG_SYS_NUM_I2C_BUSES
2020 Hold the number of i2c buses you want to use.
2022 CONFIG_SYS_I2C_DIRECT_BUS
2023 define this, if you don't use i2c muxes on your hardware.
2024 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2027 CONFIG_SYS_I2C_MAX_HOPS
2028 define how many muxes are maximal consecutively connected
2029 on one i2c bus. If you not use i2c muxes, omit this
2032 CONFIG_SYS_I2C_BUSES
2033 hold a list of buses you want to use, only used if
2034 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2035 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2036 CONFIG_SYS_NUM_I2C_BUSES = 9:
2038 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2039 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2040 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2041 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2042 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2043 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2044 {1, {I2C_NULL_HOP}}, \
2045 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2046 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2050 bus 0 on adapter 0 without a mux
2051 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2052 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2053 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2054 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2055 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2056 bus 6 on adapter 1 without a mux
2057 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2058 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2060 If you do not have i2c muxes on your board, omit this define.
2062 - Legacy I2C Support:
2063 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2064 then the following macros need to be defined (examples are
2065 from include/configs/lwmon.h):
2069 (Optional). Any commands necessary to enable the I2C
2070 controller or configure ports.
2072 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2076 The code necessary to make the I2C data line active
2077 (driven). If the data line is open collector, this
2080 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2084 The code necessary to make the I2C data line tri-stated
2085 (inactive). If the data line is open collector, this
2088 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2092 Code that returns true if the I2C data line is high,
2095 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2099 If <bit> is true, sets the I2C data line high. If it
2100 is false, it clears it (low).
2102 eg: #define I2C_SDA(bit) \
2103 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2104 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2108 If <bit> is true, sets the I2C clock line high. If it
2109 is false, it clears it (low).
2111 eg: #define I2C_SCL(bit) \
2112 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2113 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2117 This delay is invoked four times per clock cycle so this
2118 controls the rate of data transfer. The data rate thus
2119 is 1 / (I2C_DELAY * 4). Often defined to be something
2122 #define I2C_DELAY udelay(2)
2124 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2126 If your arch supports the generic GPIO framework (asm/gpio.h),
2127 then you may alternatively define the two GPIOs that are to be
2128 used as SCL / SDA. Any of the previous I2C_xxx macros will
2129 have GPIO-based defaults assigned to them as appropriate.
2131 You should define these to the GPIO value as given directly to
2132 the generic GPIO functions.
2134 CONFIG_SYS_I2C_INIT_BOARD
2136 When a board is reset during an i2c bus transfer
2137 chips might think that the current transfer is still
2138 in progress. On some boards it is possible to access
2139 the i2c SCLK line directly, either by using the
2140 processor pin as a GPIO or by having a second pin
2141 connected to the bus. If this option is defined a
2142 custom i2c_init_board() routine in boards/xxx/board.c
2143 is run early in the boot sequence.
2145 CONFIG_I2C_MULTI_BUS
2147 This option allows the use of multiple I2C buses, each of which
2148 must have a controller. At any point in time, only one bus is
2149 active. To switch to a different bus, use the 'i2c dev' command.
2150 Note that bus numbering is zero-based.
2152 CONFIG_SYS_I2C_NOPROBES
2154 This option specifies a list of I2C devices that will be skipped
2155 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2156 is set, specify a list of bus-device pairs. Otherwise, specify
2157 a 1D array of device addresses
2160 #undef CONFIG_I2C_MULTI_BUS
2161 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2163 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2165 #define CONFIG_I2C_MULTI_BUS
2166 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2168 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2170 CONFIG_SYS_SPD_BUS_NUM
2172 If defined, then this indicates the I2C bus number for DDR SPD.
2173 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2175 CONFIG_SYS_RTC_BUS_NUM
2177 If defined, then this indicates the I2C bus number for the RTC.
2178 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2180 CONFIG_SOFT_I2C_READ_REPEATED_START
2182 defining this will force the i2c_read() function in
2183 the soft_i2c driver to perform an I2C repeated start
2184 between writing the address pointer and reading the
2185 data. If this define is omitted the default behaviour
2186 of doing a stop-start sequence will be used. Most I2C
2187 devices can use either method, but some require one or
2190 - SPI Support: CONFIG_SPI
2192 Enables SPI driver (so far only tested with
2193 SPI EEPROM, also an instance works with Crystal A/D and
2194 D/As on the SACSng board)
2198 Enables the driver for SPI controller on SuperH. Currently
2199 only SH7757 is supported.
2203 Enables a software (bit-bang) SPI driver rather than
2204 using hardware support. This is a general purpose
2205 driver that only requires three general I/O port pins
2206 (two outputs, one input) to function. If this is
2207 defined, the board configuration must define several
2208 SPI configuration items (port pins to use, etc). For
2209 an example, see include/configs/sacsng.h.
2213 Enables a hardware SPI driver for general-purpose reads
2214 and writes. As with CONFIG_SOFT_SPI, the board configuration
2215 must define a list of chip-select function pointers.
2216 Currently supported on some MPC8xxx processors. For an
2217 example, see include/configs/mpc8349emds.h.
2221 Enables the driver for the SPI controllers on i.MX and MXC
2222 SoCs. Currently i.MX31/35/51 are supported.
2224 CONFIG_SYS_SPI_MXC_WAIT
2225 Timeout for waiting until spi transfer completed.
2226 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2228 - FPGA Support: CONFIG_FPGA
2230 Enables FPGA subsystem.
2232 CONFIG_FPGA_<vendor>
2234 Enables support for specific chip vendors.
2237 CONFIG_FPGA_<family>
2239 Enables support for FPGA family.
2240 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2244 Specify the number of FPGA devices to support.
2246 CONFIG_SYS_FPGA_PROG_FEEDBACK
2248 Enable printing of hash marks during FPGA configuration.
2250 CONFIG_SYS_FPGA_CHECK_BUSY
2252 Enable checks on FPGA configuration interface busy
2253 status by the configuration function. This option
2254 will require a board or device specific function to
2259 If defined, a function that provides delays in the FPGA
2260 configuration driver.
2262 CONFIG_SYS_FPGA_CHECK_CTRLC
2263 Allow Control-C to interrupt FPGA configuration
2265 CONFIG_SYS_FPGA_CHECK_ERROR
2267 Check for configuration errors during FPGA bitfile
2268 loading. For example, abort during Virtex II
2269 configuration if the INIT_B line goes low (which
2270 indicated a CRC error).
2272 CONFIG_SYS_FPGA_WAIT_INIT
2274 Maximum time to wait for the INIT_B line to de-assert
2275 after PROB_B has been de-asserted during a Virtex II
2276 FPGA configuration sequence. The default time is 500
2279 CONFIG_SYS_FPGA_WAIT_BUSY
2281 Maximum time to wait for BUSY to de-assert during
2282 Virtex II FPGA configuration. The default is 5 ms.
2284 CONFIG_SYS_FPGA_WAIT_CONFIG
2286 Time to wait after FPGA configuration. The default is
2289 - Configuration Management:
2292 Some SoCs need special image types (e.g. U-Boot binary
2293 with a special header) as build targets. By defining
2294 CONFIG_BUILD_TARGET in the SoC / board header, this
2295 special image will be automatically built upon calling
2300 If defined, this string will be added to the U-Boot
2301 version information (U_BOOT_VERSION)
2303 - Vendor Parameter Protection:
2305 U-Boot considers the values of the environment
2306 variables "serial#" (Board Serial Number) and
2307 "ethaddr" (Ethernet Address) to be parameters that
2308 are set once by the board vendor / manufacturer, and
2309 protects these variables from casual modification by
2310 the user. Once set, these variables are read-only,
2311 and write or delete attempts are rejected. You can
2312 change this behaviour:
2314 If CONFIG_ENV_OVERWRITE is #defined in your config
2315 file, the write protection for vendor parameters is
2316 completely disabled. Anybody can change or delete
2319 Alternatively, if you define _both_ an ethaddr in the
2320 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2321 Ethernet address is installed in the environment,
2322 which can be changed exactly ONCE by the user. [The
2323 serial# is unaffected by this, i. e. it remains
2326 The same can be accomplished in a more flexible way
2327 for any variable by configuring the type of access
2328 to allow for those variables in the ".flags" variable
2329 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2334 Define this variable to enable the reservation of
2335 "protected RAM", i. e. RAM which is not overwritten
2336 by U-Boot. Define CONFIG_PRAM to hold the number of
2337 kB you want to reserve for pRAM. You can overwrite
2338 this default value by defining an environment
2339 variable "pram" to the number of kB you want to
2340 reserve. Note that the board info structure will
2341 still show the full amount of RAM. If pRAM is
2342 reserved, a new environment variable "mem" will
2343 automatically be defined to hold the amount of
2344 remaining RAM in a form that can be passed as boot
2345 argument to Linux, for instance like that:
2347 setenv bootargs ... mem=\${mem}
2350 This way you can tell Linux not to use this memory,
2351 either, which results in a memory region that will
2352 not be affected by reboots.
2354 *WARNING* If your board configuration uses automatic
2355 detection of the RAM size, you must make sure that
2356 this memory test is non-destructive. So far, the
2357 following board configurations are known to be
2360 IVMS8, IVML24, SPD8xx,
2361 HERMES, IP860, RPXlite, LWMON,
2364 - Access to physical memory region (> 4GB)
2365 Some basic support is provided for operations on memory not
2366 normally accessible to U-Boot - e.g. some architectures
2367 support access to more than 4GB of memory on 32-bit
2368 machines using physical address extension or similar.
2369 Define CONFIG_PHYSMEM to access this basic support, which
2370 currently only supports clearing the memory.
2375 Define this variable to stop the system in case of a
2376 fatal error, so that you have to reset it manually.
2377 This is probably NOT a good idea for an embedded
2378 system where you want the system to reboot
2379 automatically as fast as possible, but it may be
2380 useful during development since you can try to debug
2381 the conditions that lead to the situation.
2383 CONFIG_NET_RETRY_COUNT
2385 This variable defines the number of retries for
2386 network operations like ARP, RARP, TFTP, or BOOTP
2387 before giving up the operation. If not defined, a
2388 default value of 5 is used.
2392 Timeout waiting for an ARP reply in milliseconds.
2396 Timeout in milliseconds used in NFS protocol.
2397 If you encounter "ERROR: Cannot umount" in nfs command,
2398 try longer timeout such as
2399 #define CONFIG_NFS_TIMEOUT 10000UL
2401 - Command Interpreter:
2402 CONFIG_AUTO_COMPLETE
2404 Enable auto completion of commands using TAB.
2406 CONFIG_SYS_PROMPT_HUSH_PS2
2408 This defines the secondary prompt string, which is
2409 printed when the command interpreter needs more input
2410 to complete a command. Usually "> ".
2414 In the current implementation, the local variables
2415 space and global environment variables space are
2416 separated. Local variables are those you define by
2417 simply typing `name=value'. To access a local
2418 variable later on, you have write `$name' or
2419 `${name}'; to execute the contents of a variable
2420 directly type `$name' at the command prompt.
2422 Global environment variables are those you use
2423 setenv/printenv to work with. To run a command stored
2424 in such a variable, you need to use the run command,
2425 and you must not use the '$' sign to access them.
2427 To store commands and special characters in a
2428 variable, please use double quotation marks
2429 surrounding the whole text of the variable, instead
2430 of the backslashes before semicolons and special
2433 - Command Line Editing and History:
2434 CONFIG_CMDLINE_EDITING
2436 Enable editing and History functions for interactive
2437 command line input operations
2439 - Command Line PS1/PS2 support:
2440 CONFIG_CMDLINE_PS_SUPPORT
2442 Enable support for changing the command prompt string
2443 at run-time. Only static string is supported so far.
2444 The string is obtained from environment variables PS1
2447 - Default Environment:
2448 CONFIG_EXTRA_ENV_SETTINGS
2450 Define this to contain any number of null terminated
2451 strings (variable = value pairs) that will be part of
2452 the default environment compiled into the boot image.
2454 For example, place something like this in your
2455 board's config file:
2457 #define CONFIG_EXTRA_ENV_SETTINGS \
2461 Warning: This method is based on knowledge about the
2462 internal format how the environment is stored by the
2463 U-Boot code. This is NOT an official, exported
2464 interface! Although it is unlikely that this format
2465 will change soon, there is no guarantee either.
2466 You better know what you are doing here.
2468 Note: overly (ab)use of the default environment is
2469 discouraged. Make sure to check other ways to preset
2470 the environment like the "source" command or the
2473 CONFIG_ENV_VARS_UBOOT_CONFIG
2475 Define this in order to add variables describing the
2476 U-Boot build configuration to the default environment.
2477 These will be named arch, cpu, board, vendor, and soc.
2479 Enabling this option will cause the following to be defined:
2487 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2489 Define this in order to add variables describing certain
2490 run-time determined information about the hardware to the
2491 environment. These will be named board_name, board_rev.
2493 CONFIG_DELAY_ENVIRONMENT
2495 Normally the environment is loaded when the board is
2496 initialised so that it is available to U-Boot. This inhibits
2497 that so that the environment is not available until
2498 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2499 this is instead controlled by the value of
2500 /config/load-environment.
2502 - DataFlash Support:
2503 CONFIG_HAS_DATAFLASH
2505 Defining this option enables DataFlash features and
2506 allows to read/write in Dataflash via the standard
2509 - Serial Flash support
2512 Defining this option enables SPI flash commands
2513 'sf probe/read/write/erase/update'.
2515 Usage requires an initial 'probe' to define the serial
2516 flash parameters, followed by read/write/erase/update
2519 The following defaults may be provided by the platform
2520 to handle the common case when only a single serial
2521 flash is present on the system.
2523 CONFIG_SF_DEFAULT_BUS Bus identifier
2524 CONFIG_SF_DEFAULT_CS Chip-select
2525 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2526 CONFIG_SF_DEFAULT_SPEED in Hz
2530 Define this option to include a destructive SPI flash
2533 - SystemACE Support:
2536 Adding this option adds support for Xilinx SystemACE
2537 chips attached via some sort of local bus. The address
2538 of the chip must also be defined in the
2539 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2541 #define CONFIG_SYSTEMACE
2542 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2544 When SystemACE support is added, the "ace" device type
2545 becomes available to the fat commands, i.e. fatls.
2547 - TFTP Fixed UDP Port:
2550 If this is defined, the environment variable tftpsrcp
2551 is used to supply the TFTP UDP source port value.
2552 If tftpsrcp isn't defined, the normal pseudo-random port
2553 number generator is used.
2555 Also, the environment variable tftpdstp is used to supply
2556 the TFTP UDP destination port value. If tftpdstp isn't
2557 defined, the normal port 69 is used.
2559 The purpose for tftpsrcp is to allow a TFTP server to
2560 blindly start the TFTP transfer using the pre-configured
2561 target IP address and UDP port. This has the effect of
2562 "punching through" the (Windows XP) firewall, allowing
2563 the remainder of the TFTP transfer to proceed normally.
2564 A better solution is to properly configure the firewall,
2565 but sometimes that is not allowed.
2567 - bootcount support:
2568 CONFIG_BOOTCOUNT_LIMIT
2570 This enables the bootcounter support, see:
2571 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2574 enable special bootcounter support on at91sam9xe based boards.
2576 enable special bootcounter support on da850 based boards.
2577 CONFIG_BOOTCOUNT_RAM
2578 enable support for the bootcounter in RAM
2579 CONFIG_BOOTCOUNT_I2C
2580 enable support for the bootcounter on an i2c (like RTC) device.
2581 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2582 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2584 CONFIG_BOOTCOUNT_ALEN = address len
2586 - Show boot progress:
2587 CONFIG_SHOW_BOOT_PROGRESS
2589 Defining this option allows to add some board-
2590 specific code (calling a user-provided function
2591 "show_boot_progress(int)") that enables you to show
2592 the system's boot progress on some display (for
2593 example, some LED's) on your board. At the moment,
2594 the following checkpoints are implemented:
2597 Legacy uImage format:
2600 1 common/cmd_bootm.c before attempting to boot an image
2601 -1 common/cmd_bootm.c Image header has bad magic number
2602 2 common/cmd_bootm.c Image header has correct magic number
2603 -2 common/cmd_bootm.c Image header has bad checksum
2604 3 common/cmd_bootm.c Image header has correct checksum
2605 -3 common/cmd_bootm.c Image data has bad checksum
2606 4 common/cmd_bootm.c Image data has correct checksum
2607 -4 common/cmd_bootm.c Image is for unsupported architecture
2608 5 common/cmd_bootm.c Architecture check OK
2609 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2610 6 common/cmd_bootm.c Image Type check OK
2611 -6 common/cmd_bootm.c gunzip uncompression error
2612 -7 common/cmd_bootm.c Unimplemented compression type
2613 7 common/cmd_bootm.c Uncompression OK
2614 8 common/cmd_bootm.c No uncompress/copy overwrite error
2615 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2617 9 common/image.c Start initial ramdisk verification
2618 -10 common/image.c Ramdisk header has bad magic number
2619 -11 common/image.c Ramdisk header has bad checksum
2620 10 common/image.c Ramdisk header is OK
2621 -12 common/image.c Ramdisk data has bad checksum
2622 11 common/image.c Ramdisk data has correct checksum
2623 12 common/image.c Ramdisk verification complete, start loading
2624 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2625 13 common/image.c Start multifile image verification
2626 14 common/image.c No initial ramdisk, no multifile, continue.
2628 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2630 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2631 -31 post/post.c POST test failed, detected by post_output_backlog()
2632 -32 post/post.c POST test failed, detected by post_run_single()
2634 34 common/cmd_doc.c before loading a Image from a DOC device
2635 -35 common/cmd_doc.c Bad usage of "doc" command
2636 35 common/cmd_doc.c correct usage of "doc" command
2637 -36 common/cmd_doc.c No boot device
2638 36 common/cmd_doc.c correct boot device
2639 -37 common/cmd_doc.c Unknown Chip ID on boot device
2640 37 common/cmd_doc.c correct chip ID found, device available
2641 -38 common/cmd_doc.c Read Error on boot device
2642 38 common/cmd_doc.c reading Image header from DOC device OK
2643 -39 common/cmd_doc.c Image header has bad magic number
2644 39 common/cmd_doc.c Image header has correct magic number
2645 -40 common/cmd_doc.c Error reading Image from DOC device
2646 40 common/cmd_doc.c Image header has correct magic number
2647 41 common/cmd_ide.c before loading a Image from a IDE device
2648 -42 common/cmd_ide.c Bad usage of "ide" command
2649 42 common/cmd_ide.c correct usage of "ide" command
2650 -43 common/cmd_ide.c No boot device
2651 43 common/cmd_ide.c boot device found
2652 -44 common/cmd_ide.c Device not available
2653 44 common/cmd_ide.c Device available
2654 -45 common/cmd_ide.c wrong partition selected
2655 45 common/cmd_ide.c partition selected
2656 -46 common/cmd_ide.c Unknown partition table
2657 46 common/cmd_ide.c valid partition table found
2658 -47 common/cmd_ide.c Invalid partition type
2659 47 common/cmd_ide.c correct partition type
2660 -48 common/cmd_ide.c Error reading Image Header on boot device
2661 48 common/cmd_ide.c reading Image Header from IDE device OK
2662 -49 common/cmd_ide.c Image header has bad magic number
2663 49 common/cmd_ide.c Image header has correct magic number
2664 -50 common/cmd_ide.c Image header has bad checksum
2665 50 common/cmd_ide.c Image header has correct checksum
2666 -51 common/cmd_ide.c Error reading Image from IDE device
2667 51 common/cmd_ide.c reading Image from IDE device OK
2668 52 common/cmd_nand.c before loading a Image from a NAND device
2669 -53 common/cmd_nand.c Bad usage of "nand" command
2670 53 common/cmd_nand.c correct usage of "nand" command
2671 -54 common/cmd_nand.c No boot device
2672 54 common/cmd_nand.c boot device found
2673 -55 common/cmd_nand.c Unknown Chip ID on boot device
2674 55 common/cmd_nand.c correct chip ID found, device available
2675 -56 common/cmd_nand.c Error reading Image Header on boot device
2676 56 common/cmd_nand.c reading Image Header from NAND device OK
2677 -57 common/cmd_nand.c Image header has bad magic number
2678 57 common/cmd_nand.c Image header has correct magic number
2679 -58 common/cmd_nand.c Error reading Image from NAND device
2680 58 common/cmd_nand.c reading Image from NAND device OK
2682 -60 common/env_common.c Environment has a bad CRC, using default
2684 64 net/eth.c starting with Ethernet configuration.
2685 -64 net/eth.c no Ethernet found.
2686 65 net/eth.c Ethernet found.
2688 -80 common/cmd_net.c usage wrong
2689 80 common/cmd_net.c before calling net_loop()
2690 -81 common/cmd_net.c some error in net_loop() occurred
2691 81 common/cmd_net.c net_loop() back without error
2692 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2693 82 common/cmd_net.c trying automatic boot
2694 83 common/cmd_net.c running "source" command
2695 -83 common/cmd_net.c some error in automatic boot or "source" command
2696 84 common/cmd_net.c end without errors
2701 100 common/cmd_bootm.c Kernel FIT Image has correct format
2702 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2703 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2704 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2705 102 common/cmd_bootm.c Kernel unit name specified
2706 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2707 103 common/cmd_bootm.c Found configuration node
2708 104 common/cmd_bootm.c Got kernel subimage node offset
2709 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2710 105 common/cmd_bootm.c Kernel subimage hash verification OK
2711 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2712 106 common/cmd_bootm.c Architecture check OK
2713 -106 common/cmd_bootm.c Kernel subimage has wrong type
2714 107 common/cmd_bootm.c Kernel subimage type OK
2715 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2716 108 common/cmd_bootm.c Got kernel subimage data/size
2717 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2718 -109 common/cmd_bootm.c Can't get kernel subimage type
2719 -110 common/cmd_bootm.c Can't get kernel subimage comp
2720 -111 common/cmd_bootm.c Can't get kernel subimage os
2721 -112 common/cmd_bootm.c Can't get kernel subimage load address
2722 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2724 120 common/image.c Start initial ramdisk verification
2725 -120 common/image.c Ramdisk FIT image has incorrect format
2726 121 common/image.c Ramdisk FIT image has correct format
2727 122 common/image.c No ramdisk subimage unit name, using configuration
2728 -122 common/image.c Can't get configuration for ramdisk subimage
2729 123 common/image.c Ramdisk unit name specified
2730 -124 common/image.c Can't get ramdisk subimage node offset
2731 125 common/image.c Got ramdisk subimage node offset
2732 -125 common/image.c Ramdisk subimage hash verification failed
2733 126 common/image.c Ramdisk subimage hash verification OK
2734 -126 common/image.c Ramdisk subimage for unsupported architecture
2735 127 common/image.c Architecture check OK
2736 -127 common/image.c Can't get ramdisk subimage data/size
2737 128 common/image.c Got ramdisk subimage data/size
2738 129 common/image.c Can't get ramdisk load address
2739 -129 common/image.c Got ramdisk load address
2741 -130 common/cmd_doc.c Incorrect FIT image format
2742 131 common/cmd_doc.c FIT image format OK
2744 -140 common/cmd_ide.c Incorrect FIT image format
2745 141 common/cmd_ide.c FIT image format OK
2747 -150 common/cmd_nand.c Incorrect FIT image format
2748 151 common/cmd_nand.c FIT image format OK
2750 - legacy image format:
2751 CONFIG_IMAGE_FORMAT_LEGACY
2752 enables the legacy image format support in U-Boot.
2755 enabled if CONFIG_FIT_SIGNATURE is not defined.
2757 CONFIG_DISABLE_IMAGE_LEGACY
2758 disable the legacy image format
2760 This define is introduced, as the legacy image format is
2761 enabled per default for backward compatibility.
2763 - Standalone program support:
2764 CONFIG_STANDALONE_LOAD_ADDR
2766 This option defines a board specific value for the
2767 address where standalone program gets loaded, thus
2768 overwriting the architecture dependent default
2771 - Frame Buffer Address:
2774 Define CONFIG_FB_ADDR if you want to use specific
2775 address for frame buffer. This is typically the case
2776 when using a graphics controller has separate video
2777 memory. U-Boot will then place the frame buffer at
2778 the given address instead of dynamically reserving it
2779 in system RAM by calling lcd_setmem(), which grabs
2780 the memory for the frame buffer depending on the
2781 configured panel size.
2783 Please see board_init_f function.
2785 - Automatic software updates via TFTP server
2787 CONFIG_UPDATE_TFTP_CNT_MAX
2788 CONFIG_UPDATE_TFTP_MSEC_MAX
2790 These options enable and control the auto-update feature;
2791 for a more detailed description refer to doc/README.update.
2793 - MTD Support (mtdparts command, UBI support)
2796 Adds the MTD device infrastructure from the Linux kernel.
2797 Needed for mtdparts command support.
2799 CONFIG_MTD_PARTITIONS
2801 Adds the MTD partitioning infrastructure from the Linux
2802 kernel. Needed for UBI support.
2807 Adds commands for interacting with MTD partitions formatted
2808 with the UBI flash translation layer
2810 Requires also defining CONFIG_RBTREE
2812 CONFIG_UBI_SILENCE_MSG
2814 Make the verbose messages from UBI stop printing. This leaves
2815 warnings and errors enabled.
2818 CONFIG_MTD_UBI_WL_THRESHOLD
2819 This parameter defines the maximum difference between the highest
2820 erase counter value and the lowest erase counter value of eraseblocks
2821 of UBI devices. When this threshold is exceeded, UBI starts performing
2822 wear leveling by means of moving data from eraseblock with low erase
2823 counter to eraseblocks with high erase counter.
2825 The default value should be OK for SLC NAND flashes, NOR flashes and
2826 other flashes which have eraseblock life-cycle 100000 or more.
2827 However, in case of MLC NAND flashes which typically have eraseblock
2828 life-cycle less than 10000, the threshold should be lessened (e.g.,
2829 to 128 or 256, although it does not have to be power of 2).
2833 CONFIG_MTD_UBI_BEB_LIMIT
2834 This option specifies the maximum bad physical eraseblocks UBI
2835 expects on the MTD device (per 1024 eraseblocks). If the
2836 underlying flash does not admit of bad eraseblocks (e.g. NOR
2837 flash), this value is ignored.
2839 NAND datasheets often specify the minimum and maximum NVM
2840 (Number of Valid Blocks) for the flashes' endurance lifetime.
2841 The maximum expected bad eraseblocks per 1024 eraseblocks
2842 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2843 which gives 20 for most NANDs (MaxNVB is basically the total
2844 count of eraseblocks on the chip).
2846 To put it differently, if this value is 20, UBI will try to
2847 reserve about 1.9% of physical eraseblocks for bad blocks
2848 handling. And that will be 1.9% of eraseblocks on the entire
2849 NAND chip, not just the MTD partition UBI attaches. This means
2850 that if you have, say, a NAND flash chip admits maximum 40 bad
2851 eraseblocks, and it is split on two MTD partitions of the same
2852 size, UBI will reserve 40 eraseblocks when attaching a
2857 CONFIG_MTD_UBI_FASTMAP
2858 Fastmap is a mechanism which allows attaching an UBI device
2859 in nearly constant time. Instead of scanning the whole MTD device it
2860 only has to locate a checkpoint (called fastmap) on the device.
2861 The on-flash fastmap contains all information needed to attach
2862 the device. Using fastmap makes only sense on large devices where
2863 attaching by scanning takes long. UBI will not automatically install
2864 a fastmap on old images, but you can set the UBI parameter
2865 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2866 that fastmap-enabled images are still usable with UBI implementations
2867 without fastmap support. On typical flash devices the whole fastmap
2868 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2870 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2871 Set this parameter to enable fastmap automatically on images
2875 CONFIG_MTD_UBI_FM_DEBUG
2876 Enable UBI fastmap debug
2882 Adds commands for interacting with UBI volumes formatted as
2883 UBIFS. UBIFS is read-only in u-boot.
2885 Requires UBI support as well as CONFIG_LZO
2887 CONFIG_UBIFS_SILENCE_MSG
2889 Make the verbose messages from UBIFS stop printing. This leaves
2890 warnings and errors enabled.
2894 Enable building of SPL globally.
2897 LDSCRIPT for linking the SPL binary.
2899 CONFIG_SPL_MAX_FOOTPRINT
2900 Maximum size in memory allocated to the SPL, BSS included.
2901 When defined, the linker checks that the actual memory
2902 used by SPL from _start to __bss_end does not exceed it.
2903 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2904 must not be both defined at the same time.
2907 Maximum size of the SPL image (text, data, rodata, and
2908 linker lists sections), BSS excluded.
2909 When defined, the linker checks that the actual size does
2912 CONFIG_SPL_TEXT_BASE
2913 TEXT_BASE for linking the SPL binary.
2915 CONFIG_SPL_RELOC_TEXT_BASE
2916 Address to relocate to. If unspecified, this is equal to
2917 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2919 CONFIG_SPL_BSS_START_ADDR
2920 Link address for the BSS within the SPL binary.
2922 CONFIG_SPL_BSS_MAX_SIZE
2923 Maximum size in memory allocated to the SPL BSS.
2924 When defined, the linker checks that the actual memory used
2925 by SPL from __bss_start to __bss_end does not exceed it.
2926 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2927 must not be both defined at the same time.
2930 Adress of the start of the stack SPL will use
2932 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2933 When defined, SPL will panic() if the image it has
2934 loaded does not have a signature.
2935 Defining this is useful when code which loads images
2936 in SPL cannot guarantee that absolutely all read errors
2938 An example is the LPC32XX MLC NAND driver, which will
2939 consider that a completely unreadable NAND block is bad,
2940 and thus should be skipped silently.
2942 CONFIG_SPL_RELOC_STACK
2943 Adress of the start of the stack SPL will use after
2944 relocation. If unspecified, this is equal to
2947 CONFIG_SYS_SPL_MALLOC_START
2948 Starting address of the malloc pool used in SPL.
2949 When this option is set the full malloc is used in SPL and
2950 it is set up by spl_init() and before that, the simple malloc()
2951 can be used if CONFIG_SYS_MALLOC_F is defined.
2953 CONFIG_SYS_SPL_MALLOC_SIZE
2954 The size of the malloc pool used in SPL.
2956 CONFIG_SPL_FRAMEWORK
2957 Enable the SPL framework under common/. This framework
2958 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2959 NAND loading of the Linux Kernel.
2962 Enable booting directly to an OS from SPL.
2963 See also: doc/README.falcon
2965 CONFIG_SPL_DISPLAY_PRINT
2966 For ARM, enable an optional function to print more information
2967 about the running system.
2969 CONFIG_SPL_INIT_MINIMAL
2970 Arch init code should be built for a very small image
2972 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2973 Partition on the MMC to load U-Boot from when the MMC is being
2976 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2977 Sector to load kernel uImage from when MMC is being
2978 used in raw mode (for Falcon mode)
2980 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2981 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2982 Sector and number of sectors to load kernel argument
2983 parameters from when MMC is being used in raw mode
2986 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2987 Partition on the MMC to load U-Boot from when the MMC is being
2990 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2991 Filename to read to load U-Boot when reading from filesystem
2993 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2994 Filename to read to load kernel uImage when reading
2995 from filesystem (for Falcon mode)
2997 CONFIG_SPL_FS_LOAD_ARGS_NAME
2998 Filename to read to load kernel argument parameters
2999 when reading from filesystem (for Falcon mode)
3001 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3002 Set this for NAND SPL on PPC mpc83xx targets, so that
3003 start.S waits for the rest of the SPL to load before
3004 continuing (the hardware starts execution after just
3005 loading the first page rather than the full 4K).
3007 CONFIG_SPL_SKIP_RELOCATE
3008 Avoid SPL relocation
3010 CONFIG_SPL_NAND_BASE
3011 Include nand_base.c in the SPL. Requires
3012 CONFIG_SPL_NAND_DRIVERS.
3014 CONFIG_SPL_NAND_DRIVERS
3015 SPL uses normal NAND drivers, not minimal drivers.
3018 Include standard software ECC in the SPL
3020 CONFIG_SPL_NAND_SIMPLE
3021 Support for NAND boot using simple NAND drivers that
3022 expose the cmd_ctrl() interface.
3025 Support for a lightweight UBI (fastmap) scanner and
3028 CONFIG_SPL_NAND_RAW_ONLY
3029 Support to boot only raw u-boot.bin images. Use this only
3030 if you need to save space.
3032 CONFIG_SPL_COMMON_INIT_DDR
3033 Set for common ddr init with serial presence detect in
3036 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3037 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3038 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3039 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3040 CONFIG_SYS_NAND_ECCBYTES
3041 Defines the size and behavior of the NAND that SPL uses
3044 CONFIG_SPL_NAND_BOOT
3045 Add support NAND boot
3047 CONFIG_SYS_NAND_U_BOOT_OFFS
3048 Location in NAND to read U-Boot from
3050 CONFIG_SYS_NAND_U_BOOT_DST
3051 Location in memory to load U-Boot to
3053 CONFIG_SYS_NAND_U_BOOT_SIZE
3054 Size of image to load
3056 CONFIG_SYS_NAND_U_BOOT_START
3057 Entry point in loaded image to jump to
3059 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3060 Define this if you need to first read the OOB and then the
3061 data. This is used, for example, on davinci platforms.
3063 CONFIG_SPL_OMAP3_ID_NAND
3064 Support for an OMAP3-specific set of functions to return the
3065 ID and MFR of the first attached NAND chip, if present.
3067 CONFIG_SPL_RAM_DEVICE
3068 Support for running image already present in ram, in SPL binary
3071 Image offset to which the SPL should be padded before appending
3072 the SPL payload. By default, this is defined as
3073 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3074 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3075 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3078 Final target image containing SPL and payload. Some SPLs
3079 use an arch-specific makefile fragment instead, for
3080 example if more than one image needs to be produced.
3082 CONFIG_FIT_SPL_PRINT
3083 Printing information about a FIT image adds quite a bit of
3084 code to SPL. So this is normally disabled in SPL. Use this
3085 option to re-enable it. This will affect the output of the
3086 bootm command when booting a FIT image.
3090 Enable building of TPL globally.
3093 Image offset to which the TPL should be padded before appending
3094 the TPL payload. By default, this is defined as
3095 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3096 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3097 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3099 - Interrupt support (PPC):
3101 There are common interrupt_init() and timer_interrupt()
3102 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3103 for CPU specific initialization. interrupt_init_cpu()
3104 should set decrementer_count to appropriate value. If
3105 CPU resets decrementer automatically after interrupt
3106 (ppc4xx) it should set decrementer_count to zero.
3107 timer_interrupt() calls timer_interrupt_cpu() for CPU
3108 specific handling. If board has watchdog / status_led
3109 / other_activity_monitor it works automatically from
3110 general timer_interrupt().
3113 Board initialization settings:
3114 ------------------------------
3116 During Initialization u-boot calls a number of board specific functions
3117 to allow the preparation of board specific prerequisites, e.g. pin setup
3118 before drivers are initialized. To enable these callbacks the
3119 following configuration macros have to be defined. Currently this is
3120 architecture specific, so please check arch/your_architecture/lib/board.c
3121 typically in board_init_f() and board_init_r().
3123 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3124 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3125 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3126 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3128 Configuration Settings:
3129 -----------------------
3131 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3132 Optionally it can be defined to support 64-bit memory commands.
3134 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3135 undefine this when you're short of memory.
3137 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3138 width of the commands listed in the 'help' command output.
3140 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3141 prompt for user input.
3143 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3145 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3147 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3149 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3150 the application (usually a Linux kernel) when it is
3153 - CONFIG_SYS_BAUDRATE_TABLE:
3154 List of legal baudrate settings for this board.
3156 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3157 Begin and End addresses of the area used by the
3160 - CONFIG_SYS_ALT_MEMTEST:
3161 Enable an alternate, more extensive memory test.
3163 - CONFIG_SYS_MEMTEST_SCRATCH:
3164 Scratch address used by the alternate memory test
3165 You only need to set this if address zero isn't writeable
3167 - CONFIG_SYS_MEM_RESERVE_SECURE
3168 Only implemented for ARMv8 for now.
3169 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3170 is substracted from total RAM and won't be reported to OS.
3171 This memory can be used as secure memory. A variable
3172 gd->arch.secure_ram is used to track the location. In systems
3173 the RAM base is not zero, or RAM is divided into banks,
3174 this variable needs to be recalcuated to get the address.
3176 - CONFIG_SYS_MEM_TOP_HIDE:
3177 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3178 this specified memory area will get subtracted from the top
3179 (end) of RAM and won't get "touched" at all by U-Boot. By
3180 fixing up gd->ram_size the Linux kernel should gets passed
3181 the now "corrected" memory size and won't touch it either.
3182 This should work for arch/ppc and arch/powerpc. Only Linux
3183 board ports in arch/powerpc with bootwrapper support that
3184 recalculate the memory size from the SDRAM controller setup
3185 will have to get fixed in Linux additionally.
3187 This option can be used as a workaround for the 440EPx/GRx
3188 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3191 WARNING: Please make sure that this value is a multiple of
3192 the Linux page size (normally 4k). If this is not the case,
3193 then the end address of the Linux memory will be located at a
3194 non page size aligned address and this could cause major
3197 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3198 Enable temporary baudrate change while serial download
3200 - CONFIG_SYS_SDRAM_BASE:
3201 Physical start address of SDRAM. _Must_ be 0 here.
3203 - CONFIG_SYS_FLASH_BASE:
3204 Physical start address of Flash memory.
3206 - CONFIG_SYS_MONITOR_BASE:
3207 Physical start address of boot monitor code (set by
3208 make config files to be same as the text base address
3209 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3210 CONFIG_SYS_FLASH_BASE when booting from flash.
3212 - CONFIG_SYS_MONITOR_LEN:
3213 Size of memory reserved for monitor code, used to
3214 determine _at_compile_time_ (!) if the environment is
3215 embedded within the U-Boot image, or in a separate
3218 - CONFIG_SYS_MALLOC_LEN:
3219 Size of DRAM reserved for malloc() use.
3221 - CONFIG_SYS_MALLOC_F_LEN
3222 Size of the malloc() pool for use before relocation. If
3223 this is defined, then a very simple malloc() implementation
3224 will become available before relocation. The address is just
3225 below the global data, and the stack is moved down to make
3228 This feature allocates regions with increasing addresses
3229 within the region. calloc() is supported, but realloc()
3230 is not available. free() is supported but does nothing.
3231 The memory will be freed (or in fact just forgotten) when
3232 U-Boot relocates itself.
3234 - CONFIG_SYS_MALLOC_SIMPLE
3235 Provides a simple and small malloc() and calloc() for those
3236 boards which do not use the full malloc in SPL (which is
3237 enabled with CONFIG_SYS_SPL_MALLOC_START).
3239 - CONFIG_SYS_NONCACHED_MEMORY:
3240 Size of non-cached memory area. This area of memory will be
3241 typically located right below the malloc() area and mapped
3242 uncached in the MMU. This is useful for drivers that would
3243 otherwise require a lot of explicit cache maintenance. For
3244 some drivers it's also impossible to properly maintain the
3245 cache. For example if the regions that need to be flushed
3246 are not a multiple of the cache-line size, *and* padding
3247 cannot be allocated between the regions to align them (i.e.
3248 if the HW requires a contiguous array of regions, and the
3249 size of each region is not cache-aligned), then a flush of
3250 one region may result in overwriting data that hardware has
3251 written to another region in the same cache-line. This can
3252 happen for example in network drivers where descriptors for
3253 buffers are typically smaller than the CPU cache-line (e.g.
3254 16 bytes vs. 32 or 64 bytes).
3256 Non-cached memory is only supported on 32-bit ARM at present.
3258 - CONFIG_SYS_BOOTM_LEN:
3259 Normally compressed uImages are limited to an
3260 uncompressed size of 8 MBytes. If this is not enough,
3261 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3262 to adjust this setting to your needs.
3264 - CONFIG_SYS_BOOTMAPSZ:
3265 Maximum size of memory mapped by the startup code of
3266 the Linux kernel; all data that must be processed by
3267 the Linux kernel (bd_info, boot arguments, FDT blob if
3268 used) must be put below this limit, unless "bootm_low"
3269 environment variable is defined and non-zero. In such case
3270 all data for the Linux kernel must be between "bootm_low"
3271 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3272 variable "bootm_mapsize" will override the value of
3273 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3274 then the value in "bootm_size" will be used instead.
3276 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3277 Enable initrd_high functionality. If defined then the
3278 initrd_high feature is enabled and the bootm ramdisk subcommand
3281 - CONFIG_SYS_BOOT_GET_CMDLINE:
3282 Enables allocating and saving kernel cmdline in space between
3283 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3285 - CONFIG_SYS_BOOT_GET_KBD:
3286 Enables allocating and saving a kernel copy of the bd_info in
3287 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3289 - CONFIG_SYS_MAX_FLASH_BANKS:
3290 Max number of Flash memory banks
3292 - CONFIG_SYS_MAX_FLASH_SECT:
3293 Max number of sectors on a Flash chip
3295 - CONFIG_SYS_FLASH_ERASE_TOUT:
3296 Timeout for Flash erase operations (in ms)
3298 - CONFIG_SYS_FLASH_WRITE_TOUT:
3299 Timeout for Flash write operations (in ms)
3301 - CONFIG_SYS_FLASH_LOCK_TOUT
3302 Timeout for Flash set sector lock bit operation (in ms)
3304 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3305 Timeout for Flash clear lock bits operation (in ms)
3307 - CONFIG_SYS_FLASH_PROTECTION
3308 If defined, hardware flash sectors protection is used
3309 instead of U-Boot software protection.
3311 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3313 Enable TFTP transfers directly to flash memory;
3314 without this option such a download has to be
3315 performed in two steps: (1) download to RAM, and (2)
3316 copy from RAM to flash.
3318 The two-step approach is usually more reliable, since
3319 you can check if the download worked before you erase
3320 the flash, but in some situations (when system RAM is
3321 too limited to allow for a temporary copy of the
3322 downloaded image) this option may be very useful.
3324 - CONFIG_SYS_FLASH_CFI:
3325 Define if the flash driver uses extra elements in the
3326 common flash structure for storing flash geometry.
3328 - CONFIG_FLASH_CFI_DRIVER
3329 This option also enables the building of the cfi_flash driver
3330 in the drivers directory
3332 - CONFIG_FLASH_CFI_MTD
3333 This option enables the building of the cfi_mtd driver
3334 in the drivers directory. The driver exports CFI flash
3337 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3338 Use buffered writes to flash.
3340 - CONFIG_FLASH_SPANSION_S29WS_N
3341 s29ws-n MirrorBit flash has non-standard addresses for buffered
3344 - CONFIG_SYS_FLASH_QUIET_TEST
3345 If this option is defined, the common CFI flash doesn't
3346 print it's warning upon not recognized FLASH banks. This
3347 is useful, if some of the configured banks are only
3348 optionally available.
3350 - CONFIG_FLASH_SHOW_PROGRESS
3351 If defined (must be an integer), print out countdown
3352 digits and dots. Recommended value: 45 (9..1) for 80
3353 column displays, 15 (3..1) for 40 column displays.
3355 - CONFIG_FLASH_VERIFY
3356 If defined, the content of the flash (destination) is compared
3357 against the source after the write operation. An error message
3358 will be printed when the contents are not identical.
3359 Please note that this option is useless in nearly all cases,
3360 since such flash programming errors usually are detected earlier
3361 while unprotecting/erasing/programming. Please only enable
3362 this option if you really know what you are doing.
3364 - CONFIG_SYS_RX_ETH_BUFFER:
3365 Defines the number of Ethernet receive buffers. On some
3366 Ethernet controllers it is recommended to set this value
3367 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3368 buffers can be full shortly after enabling the interface
3369 on high Ethernet traffic.
3370 Defaults to 4 if not defined.
3372 - CONFIG_ENV_MAX_ENTRIES
3374 Maximum number of entries in the hash table that is used
3375 internally to store the environment settings. The default
3376 setting is supposed to be generous and should work in most
3377 cases. This setting can be used to tune behaviour; see
3378 lib/hashtable.c for details.
3380 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3381 - CONFIG_ENV_FLAGS_LIST_STATIC
3382 Enable validation of the values given to environment variables when
3383 calling env set. Variables can be restricted to only decimal,
3384 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3385 the variables can also be restricted to IP address or MAC address.
3387 The format of the list is:
3388 type_attribute = [s|d|x|b|i|m]
3389 access_attribute = [a|r|o|c]
3390 attributes = type_attribute[access_attribute]
3391 entry = variable_name[:attributes]
3394 The type attributes are:
3395 s - String (default)
3398 b - Boolean ([1yYtT|0nNfF])
3402 The access attributes are:
3408 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3409 Define this to a list (string) to define the ".flags"
3410 environment variable in the default or embedded environment.
3412 - CONFIG_ENV_FLAGS_LIST_STATIC
3413 Define this to a list (string) to define validation that
3414 should be done if an entry is not found in the ".flags"
3415 environment variable. To override a setting in the static
3416 list, simply add an entry for the same variable name to the
3419 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3420 regular expression. This allows multiple variables to define the same
3421 flags without explicitly listing them for each variable.
3423 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3424 If defined, don't allow the -f switch to env set override variable
3428 If stdint.h is available with your toolchain you can define this
3429 option to enable it. You can provide option 'USE_STDINT=1' when
3430 building U-Boot to enable this.
3432 The following definitions that deal with the placement and management
3433 of environment data (variable area); in general, we support the
3434 following configurations:
3436 - CONFIG_BUILD_ENVCRC:
3438 Builds up envcrc with the target environment so that external utils
3439 may easily extract it and embed it in final U-Boot images.
3441 - CONFIG_ENV_IS_IN_FLASH:
3443 Define this if the environment is in flash memory.
3445 a) The environment occupies one whole flash sector, which is
3446 "embedded" in the text segment with the U-Boot code. This
3447 happens usually with "bottom boot sector" or "top boot
3448 sector" type flash chips, which have several smaller
3449 sectors at the start or the end. For instance, such a
3450 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3451 such a case you would place the environment in one of the
3452 4 kB sectors - with U-Boot code before and after it. With
3453 "top boot sector" type flash chips, you would put the
3454 environment in one of the last sectors, leaving a gap
3455 between U-Boot and the environment.
3457 - CONFIG_ENV_OFFSET:
3459 Offset of environment data (variable area) to the
3460 beginning of flash memory; for instance, with bottom boot
3461 type flash chips the second sector can be used: the offset
3462 for this sector is given here.
3464 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3468 This is just another way to specify the start address of
3469 the flash sector containing the environment (instead of
3472 - CONFIG_ENV_SECT_SIZE:
3474 Size of the sector containing the environment.
3477 b) Sometimes flash chips have few, equal sized, BIG sectors.
3478 In such a case you don't want to spend a whole sector for
3483 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3484 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3485 of this flash sector for the environment. This saves
3486 memory for the RAM copy of the environment.
3488 It may also save flash memory if you decide to use this
3489 when your environment is "embedded" within U-Boot code,
3490 since then the remainder of the flash sector could be used
3491 for U-Boot code. It should be pointed out that this is
3492 STRONGLY DISCOURAGED from a robustness point of view:
3493 updating the environment in flash makes it always
3494 necessary to erase the WHOLE sector. If something goes
3495 wrong before the contents has been restored from a copy in
3496 RAM, your target system will be dead.
3498 - CONFIG_ENV_ADDR_REDUND
3499 CONFIG_ENV_SIZE_REDUND
3501 These settings describe a second storage area used to hold
3502 a redundant copy of the environment data, so that there is
3503 a valid backup copy in case there is a power failure during
3504 a "saveenv" operation.
3506 BE CAREFUL! Any changes to the flash layout, and some changes to the
3507 source code will make it necessary to adapt <board>/u-boot.lds*
3511 - CONFIG_ENV_IS_IN_NVRAM:
3513 Define this if you have some non-volatile memory device
3514 (NVRAM, battery buffered SRAM) which you want to use for the
3520 These two #defines are used to determine the memory area you
3521 want to use for environment. It is assumed that this memory
3522 can just be read and written to, without any special
3525 BE CAREFUL! The first access to the environment happens quite early
3526 in U-Boot initialization (when we try to get the setting of for the
3527 console baudrate). You *MUST* have mapped your NVRAM area then, or
3530 Please note that even with NVRAM we still use a copy of the
3531 environment in RAM: we could work on NVRAM directly, but we want to
3532 keep settings there always unmodified except somebody uses "saveenv"
3533 to save the current settings.
3536 - CONFIG_ENV_IS_IN_EEPROM:
3538 Use this if you have an EEPROM or similar serial access
3539 device and a driver for it.
3541 - CONFIG_ENV_OFFSET:
3544 These two #defines specify the offset and size of the
3545 environment area within the total memory of your EEPROM.
3547 - CONFIG_SYS_I2C_EEPROM_ADDR:
3548 If defined, specified the chip address of the EEPROM device.
3549 The default address is zero.
3551 - CONFIG_SYS_I2C_EEPROM_BUS:
3552 If defined, specified the i2c bus of the EEPROM device.
3554 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3555 If defined, the number of bits used to address bytes in a
3556 single page in the EEPROM device. A 64 byte page, for example
3557 would require six bits.
3559 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3560 If defined, the number of milliseconds to delay between
3561 page writes. The default is zero milliseconds.
3563 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3564 The length in bytes of the EEPROM memory array address. Note
3565 that this is NOT the chip address length!
3567 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3568 EEPROM chips that implement "address overflow" are ones
3569 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3570 address and the extra bits end up in the "chip address" bit
3571 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3574 Note that we consider the length of the address field to
3575 still be one byte because the extra address bits are hidden
3576 in the chip address.
3578 - CONFIG_SYS_EEPROM_SIZE:
3579 The size in bytes of the EEPROM device.
3581 - CONFIG_ENV_EEPROM_IS_ON_I2C
3582 define this, if you have I2C and SPI activated, and your
3583 EEPROM, which holds the environment, is on the I2C bus.
3585 - CONFIG_I2C_ENV_EEPROM_BUS
3586 if you have an Environment on an EEPROM reached over
3587 I2C muxes, you can define here, how to reach this
3588 EEPROM. For example:
3590 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3592 EEPROM which holds the environment, is reached over
3593 a pca9547 i2c mux with address 0x70, channel 3.
3595 - CONFIG_ENV_IS_IN_DATAFLASH:
3597 Define this if you have a DataFlash memory device which you
3598 want to use for the environment.
3600 - CONFIG_ENV_OFFSET:
3604 These three #defines specify the offset and size of the
3605 environment area within the total memory of your DataFlash placed
3606 at the specified address.
3608 - CONFIG_ENV_IS_IN_SPI_FLASH:
3610 Define this if you have a SPI Flash memory device which you
3611 want to use for the environment.
3613 - CONFIG_ENV_OFFSET:
3616 These two #defines specify the offset and size of the
3617 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3618 aligned to an erase sector boundary.
3620 - CONFIG_ENV_SECT_SIZE:
3622 Define the SPI flash's sector size.
3624 - CONFIG_ENV_OFFSET_REDUND (optional):
3626 This setting describes a second storage area of CONFIG_ENV_SIZE
3627 size used to hold a redundant copy of the environment data, so
3628 that there is a valid backup copy in case there is a power failure
3629 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3630 aligned to an erase sector boundary.
3632 - CONFIG_ENV_SPI_BUS (optional):
3633 - CONFIG_ENV_SPI_CS (optional):
3635 Define the SPI bus and chip select. If not defined they will be 0.
3637 - CONFIG_ENV_SPI_MAX_HZ (optional):
3639 Define the SPI max work clock. If not defined then use 1MHz.
3641 - CONFIG_ENV_SPI_MODE (optional):
3643 Define the SPI work mode. If not defined then use SPI_MODE_3.
3645 - CONFIG_ENV_IS_IN_REMOTE:
3647 Define this if you have a remote memory space which you
3648 want to use for the local device's environment.
3653 These two #defines specify the address and size of the
3654 environment area within the remote memory space. The
3655 local device can get the environment from remote memory
3656 space by SRIO or PCIE links.
3658 BE CAREFUL! For some special cases, the local device can not use
3659 "saveenv" command. For example, the local device will get the
3660 environment stored in a remote NOR flash by SRIO or PCIE link,
3661 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3663 - CONFIG_ENV_IS_IN_NAND:
3665 Define this if you have a NAND device which you want to use
3666 for the environment.
3668 - CONFIG_ENV_OFFSET:
3671 These two #defines specify the offset and size of the environment
3672 area within the first NAND device. CONFIG_ENV_OFFSET must be
3673 aligned to an erase block boundary.
3675 - CONFIG_ENV_OFFSET_REDUND (optional):
3677 This setting describes a second storage area of CONFIG_ENV_SIZE
3678 size used to hold a redundant copy of the environment data, so
3679 that there is a valid backup copy in case there is a power failure
3680 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3681 aligned to an erase block boundary.
3683 - CONFIG_ENV_RANGE (optional):
3685 Specifies the length of the region in which the environment
3686 can be written. This should be a multiple of the NAND device's
3687 block size. Specifying a range with more erase blocks than
3688 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3689 the range to be avoided.
3691 - CONFIG_ENV_OFFSET_OOB (optional):
3693 Enables support for dynamically retrieving the offset of the
3694 environment from block zero's out-of-band data. The
3695 "nand env.oob" command can be used to record this offset.
3696 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3697 using CONFIG_ENV_OFFSET_OOB.
3699 - CONFIG_NAND_ENV_DST
3701 Defines address in RAM to which the nand_spl code should copy the
3702 environment. If redundant environment is used, it will be copied to
3703 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3705 - CONFIG_ENV_IS_IN_UBI:
3707 Define this if you have an UBI volume that you want to use for the
3708 environment. This has the benefit of wear-leveling the environment
3709 accesses, which is important on NAND.
3711 - CONFIG_ENV_UBI_PART:
3713 Define this to a string that is the mtd partition containing the UBI.
3715 - CONFIG_ENV_UBI_VOLUME:
3717 Define this to the name of the volume that you want to store the
3720 - CONFIG_ENV_UBI_VOLUME_REDUND:
3722 Define this to the name of another volume to store a second copy of
3723 the environment in. This will enable redundant environments in UBI.
3724 It is assumed that both volumes are in the same MTD partition.
3726 - CONFIG_UBI_SILENCE_MSG
3727 - CONFIG_UBIFS_SILENCE_MSG
3729 You will probably want to define these to avoid a really noisy system
3730 when storing the env in UBI.
3732 - CONFIG_ENV_IS_IN_FAT:
3733 Define this if you want to use the FAT file system for the environment.
3735 - FAT_ENV_INTERFACE:
3737 Define this to a string that is the name of the block device.
3739 - FAT_ENV_DEVICE_AND_PART:
3741 Define this to a string to specify the partition of the device. It can
3744 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3745 - "D:P": device D partition P. Error occurs if device D has no
3748 - "D" or "D:": device D partition 1 if device D has partition
3749 table, or the whole device D if has no partition
3751 - "D:auto": first partition in device D with bootable flag set.
3752 If none, first valid partition in device D. If no
3753 partition table then means device D.
3757 It's a string of the FAT file name. This file use to store the
3761 This must be enabled. Otherwise it cannot save the environment file.
3763 - CONFIG_ENV_IS_IN_MMC:
3765 Define this if you have an MMC device which you want to use for the
3768 - CONFIG_SYS_MMC_ENV_DEV:
3770 Specifies which MMC device the environment is stored in.
3772 - CONFIG_SYS_MMC_ENV_PART (optional):
3774 Specifies which MMC partition the environment is stored in. If not
3775 set, defaults to partition 0, the user area. Common values might be
3776 1 (first MMC boot partition), 2 (second MMC boot partition).
3778 - CONFIG_ENV_OFFSET:
3781 These two #defines specify the offset and size of the environment
3782 area within the specified MMC device.
3784 If offset is positive (the usual case), it is treated as relative to
3785 the start of the MMC partition. If offset is negative, it is treated
3786 as relative to the end of the MMC partition. This can be useful if
3787 your board may be fitted with different MMC devices, which have
3788 different sizes for the MMC partitions, and you always want the
3789 environment placed at the very end of the partition, to leave the
3790 maximum possible space before it, to store other data.
3792 These two values are in units of bytes, but must be aligned to an
3793 MMC sector boundary.
3795 - CONFIG_ENV_OFFSET_REDUND (optional):
3797 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3798 hold a redundant copy of the environment data. This provides a
3799 valid backup copy in case the other copy is corrupted, e.g. due
3800 to a power failure during a "saveenv" operation.
3802 This value may also be positive or negative; this is handled in the
3803 same way as CONFIG_ENV_OFFSET.
3805 This value is also in units of bytes, but must also be aligned to
3806 an MMC sector boundary.
3808 - CONFIG_ENV_SIZE_REDUND (optional):
3810 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3811 set. If this value is set, it must be set to the same value as
3814 Please note that the environment is read-only until the monitor
3815 has been relocated to RAM and a RAM copy of the environment has been
3816 created; also, when using EEPROM you will have to use getenv_f()
3817 until then to read environment variables.
3819 The environment is protected by a CRC32 checksum. Before the monitor
3820 is relocated into RAM, as a result of a bad CRC you will be working
3821 with the compiled-in default environment - *silently*!!! [This is
3822 necessary, because the first environment variable we need is the
3823 "baudrate" setting for the console - if we have a bad CRC, we don't
3824 have any device yet where we could complain.]
3826 Note: once the monitor has been relocated, then it will complain if
3827 the default environment is used; a new CRC is computed as soon as you
3828 use the "saveenv" command to store a valid environment.
3830 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3831 Echo the inverted Ethernet link state to the fault LED.
3833 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3834 also needs to be defined.
3836 - CONFIG_SYS_FAULT_MII_ADDR:
3837 MII address of the PHY to check for the Ethernet link state.
3839 - CONFIG_NS16550_MIN_FUNCTIONS:
3840 Define this if you desire to only have use of the NS16550_init
3841 and NS16550_putc functions for the serial driver located at
3842 drivers/serial/ns16550.c. This option is useful for saving
3843 space for already greatly restricted images, including but not
3844 limited to NAND_SPL configurations.
3846 - CONFIG_DISPLAY_BOARDINFO
3847 Display information about the board that U-Boot is running on
3848 when U-Boot starts up. The board function checkboard() is called
3851 - CONFIG_DISPLAY_BOARDINFO_LATE
3852 Similar to the previous option, but display this information
3853 later, once stdio is running and output goes to the LCD, if
3856 - CONFIG_BOARD_SIZE_LIMIT:
3857 Maximum size of the U-Boot image. When defined, the
3858 build system checks that the actual size does not
3861 Low Level (hardware related) configuration options:
3862 ---------------------------------------------------
3864 - CONFIG_SYS_CACHELINE_SIZE:
3865 Cache Line Size of the CPU.
3867 - CONFIG_SYS_CCSRBAR_DEFAULT:
3868 Default (power-on reset) physical address of CCSR on Freescale
3871 - CONFIG_SYS_CCSRBAR:
3872 Virtual address of CCSR. On a 32-bit build, this is typically
3873 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3875 - CONFIG_SYS_CCSRBAR_PHYS:
3876 Physical address of CCSR. CCSR can be relocated to a new
3877 physical address, if desired. In this case, this macro should
3878 be set to that address. Otherwise, it should be set to the
3879 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3880 is typically relocated on 36-bit builds. It is recommended
3881 that this macro be defined via the _HIGH and _LOW macros:
3883 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3884 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3886 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3887 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3888 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3889 used in assembly code, so it must not contain typecasts or
3890 integer size suffixes (e.g. "ULL").
3892 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3893 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3894 used in assembly code, so it must not contain typecasts or
3895 integer size suffixes (e.g. "ULL").
3897 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3898 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3899 forced to a value that ensures that CCSR is not relocated.
3901 - Floppy Disk Support:
3902 CONFIG_SYS_FDC_DRIVE_NUMBER
3904 the default drive number (default value 0)
3906 CONFIG_SYS_ISA_IO_STRIDE
3908 defines the spacing between FDC chipset registers
3911 CONFIG_SYS_ISA_IO_OFFSET
3913 defines the offset of register from address. It
3914 depends on which part of the data bus is connected to
3915 the FDC chipset. (default value 0)
3917 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3918 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3921 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3922 fdc_hw_init() is called at the beginning of the FDC
3923 setup. fdc_hw_init() must be provided by the board
3924 source code. It is used to make hardware-dependent
3928 Most IDE controllers were designed to be connected with PCI
3929 interface. Only few of them were designed for AHB interface.
3930 When software is doing ATA command and data transfer to
3931 IDE devices through IDE-AHB controller, some additional
3932 registers accessing to these kind of IDE-AHB controller
3935 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3936 DO NOT CHANGE unless you know exactly what you're
3937 doing! (11-4) [MPC8xx systems only]
3939 - CONFIG_SYS_INIT_RAM_ADDR:
3941 Start address of memory area that can be used for
3942 initial data and stack; please note that this must be
3943 writable memory that is working WITHOUT special
3944 initialization, i. e. you CANNOT use normal RAM which
3945 will become available only after programming the
3946 memory controller and running certain initialization
3949 U-Boot uses the following memory types:
3950 - MPC8xx: IMMR (internal memory of the CPU)
3952 - CONFIG_SYS_GBL_DATA_OFFSET:
3954 Offset of the initial data structure in the memory
3955 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3956 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3957 data is located at the end of the available space
3958 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3959 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3960 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3961 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3964 On the MPC824X (or other systems that use the data
3965 cache for initial memory) the address chosen for
3966 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3967 point to an otherwise UNUSED address space between
3968 the top of RAM and the start of the PCI space.
3970 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3972 - CONFIG_SYS_OR_TIMING_SDRAM:
3975 - CONFIG_SYS_MAMR_PTA:
3976 periodic timer for refresh
3978 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3979 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3980 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3981 CONFIG_SYS_BR1_PRELIM:
3982 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3984 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3985 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3986 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3987 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3989 - CONFIG_PCI_ENUM_ONLY
3990 Only scan through and get the devices on the buses.
3991 Don't do any setup work, presumably because someone or
3992 something has already done it, and we don't need to do it
3993 a second time. Useful for platforms that are pre-booted
3994 by coreboot or similar.
3996 - CONFIG_PCI_INDIRECT_BRIDGE:
3997 Enable support for indirect PCI bridges.
4000 Chip has SRIO or not
4003 Board has SRIO 1 port available
4006 Board has SRIO 2 port available
4008 - CONFIG_SRIO_PCIE_BOOT_MASTER
4009 Board can support master function for Boot from SRIO and PCIE
4011 - CONFIG_SYS_SRIOn_MEM_VIRT:
4012 Virtual Address of SRIO port 'n' memory region
4014 - CONFIG_SYS_SRIOn_MEM_PHYS:
4015 Physical Address of SRIO port 'n' memory region
4017 - CONFIG_SYS_SRIOn_MEM_SIZE:
4018 Size of SRIO port 'n' memory region
4020 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4021 Defined to tell the NAND controller that the NAND chip is using
4023 Not all NAND drivers use this symbol.
4024 Example of drivers that use it:
4025 - drivers/mtd/nand/ndfc.c
4026 - drivers/mtd/nand/mxc_nand.c
4028 - CONFIG_SYS_NDFC_EBC0_CFG
4029 Sets the EBC0_CFG register for the NDFC. If not defined
4030 a default value will be used.
4033 Get DDR timing information from an I2C EEPROM. Common
4034 with pluggable memory modules such as SODIMMs
4037 I2C address of the SPD EEPROM
4039 - CONFIG_SYS_SPD_BUS_NUM
4040 If SPD EEPROM is on an I2C bus other than the first
4041 one, specify here. Note that the value must resolve
4042 to something your driver can deal with.
4044 - CONFIG_SYS_DDR_RAW_TIMING
4045 Get DDR timing information from other than SPD. Common with
4046 soldered DDR chips onboard without SPD. DDR raw timing
4047 parameters are extracted from datasheet and hard-coded into
4048 header files or board specific files.
4050 - CONFIG_FSL_DDR_INTERACTIVE
4051 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4053 - CONFIG_FSL_DDR_SYNC_REFRESH
4054 Enable sync of refresh for multiple controllers.
4056 - CONFIG_FSL_DDR_BIST
4057 Enable built-in memory test for Freescale DDR controllers.
4059 - CONFIG_SYS_83XX_DDR_USES_CS0
4060 Only for 83xx systems. If specified, then DDR should
4061 be configured using CS0 and CS1 instead of CS2 and CS3.
4064 Enable RMII mode for all FECs.
4065 Note that this is a global option, we can't
4066 have one FEC in standard MII mode and another in RMII mode.
4068 - CONFIG_CRC32_VERIFY
4069 Add a verify option to the crc32 command.
4072 => crc32 -v <address> <count> <crc32>
4074 Where address/count indicate a memory area
4075 and crc32 is the correct crc32 which the
4079 Add the "loopw" memory command. This only takes effect if
4080 the memory commands are activated globally (CONFIG_CMD_MEM).
4083 Add the "mdc" and "mwc" memory commands. These are cyclic
4088 This command will print 4 bytes (10,11,12,13) each 500 ms.
4090 => mwc.l 100 12345678 10
4091 This command will write 12345678 to address 100 all 10 ms.
4093 This only takes effect if the memory commands are activated
4094 globally (CONFIG_CMD_MEM).
4096 - CONFIG_SKIP_LOWLEVEL_INIT
4097 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4098 low level initializations (like setting up the memory
4099 controller) are omitted and/or U-Boot does not
4100 relocate itself into RAM.
4102 Normally this variable MUST NOT be defined. The only
4103 exception is when U-Boot is loaded (to RAM) by some
4104 other boot loader or by a debugger which performs
4105 these initializations itself.
4107 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4108 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4109 to be skipped. The normal CP15 init (such as enabling the
4110 instruction cache) is still performed.
4113 Modifies the behaviour of start.S when compiling a loader
4114 that is executed before the actual U-Boot. E.g. when
4115 compiling a NAND SPL.
4118 Modifies the behaviour of start.S when compiling a loader
4119 that is executed after the SPL and before the actual U-Boot.
4120 It is loaded by the SPL.
4122 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4123 Only for 85xx systems. If this variable is specified, the section
4124 .resetvec is not kept and the section .bootpg is placed in the
4125 previous 4k of the .text section.
4127 - CONFIG_ARCH_MAP_SYSMEM
4128 Generally U-Boot (and in particular the md command) uses
4129 effective address. It is therefore not necessary to regard
4130 U-Boot address as virtual addresses that need to be translated
4131 to physical addresses. However, sandbox requires this, since
4132 it maintains its own little RAM buffer which contains all
4133 addressable memory. This option causes some memory accesses
4134 to be mapped through map_sysmem() / unmap_sysmem().
4136 - CONFIG_X86_RESET_VECTOR
4137 If defined, the x86 reset vector code is included. This is not
4138 needed when U-Boot is running from Coreboot.
4140 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4141 Enables the RTC32K OSC on AM33xx based plattforms
4143 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4144 Option to disable subpage write in NAND driver
4145 driver that uses this:
4146 drivers/mtd/nand/davinci_nand.c
4148 Freescale QE/FMAN Firmware Support:
4149 -----------------------------------
4151 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4152 loading of "firmware", which is encoded in the QE firmware binary format.
4153 This firmware often needs to be loaded during U-Boot booting, so macros
4154 are used to identify the storage device (NOR flash, SPI, etc) and the address
4157 - CONFIG_SYS_FMAN_FW_ADDR
4158 The address in the storage device where the FMAN microcode is located. The
4159 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4162 - CONFIG_SYS_QE_FW_ADDR
4163 The address in the storage device where the QE microcode is located. The
4164 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4167 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4168 The maximum possible size of the firmware. The firmware binary format
4169 has a field that specifies the actual size of the firmware, but it
4170 might not be possible to read any part of the firmware unless some
4171 local storage is allocated to hold the entire firmware first.
4173 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4174 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4175 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4176 virtual address in NOR flash.
4178 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4179 Specifies that QE/FMAN firmware is located in NAND flash.
4180 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4182 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4183 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4184 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4186 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4187 Specifies that QE/FMAN firmware is located in the remote (master)
4188 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4189 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4190 window->master inbound window->master LAW->the ucode address in
4191 master's memory space.
4193 Freescale Layerscape Management Complex Firmware Support:
4194 ---------------------------------------------------------
4195 The Freescale Layerscape Management Complex (MC) supports the loading of
4197 This firmware often needs to be loaded during U-Boot booting, so macros
4198 are used to identify the storage device (NOR flash, SPI, etc) and the address
4201 - CONFIG_FSL_MC_ENET
4202 Enable the MC driver for Layerscape SoCs.
4204 Freescale Layerscape Debug Server Support:
4205 -------------------------------------------
4206 The Freescale Layerscape Debug Server Support supports the loading of
4207 "Debug Server firmware" and triggering SP boot-rom.
4208 This firmware often needs to be loaded during U-Boot booting.
4210 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4211 Define alignment of reserved memory MC requires
4216 In order to achieve reproducible builds, timestamps used in the U-Boot build
4217 process have to be set to a fixed value.
4219 This is done using the SOURCE_DATE_EPOCH environment variable.
4220 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4221 option for U-Boot or an environment variable in U-Boot.
4223 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4225 Building the Software:
4226 ======================
4228 Building U-Boot has been tested in several native build environments
4229 and in many different cross environments. Of course we cannot support
4230 all possibly existing versions of cross development tools in all
4231 (potentially obsolete) versions. In case of tool chain problems we
4232 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4233 which is extensively used to build and test U-Boot.
4235 If you are not using a native environment, it is assumed that you
4236 have GNU cross compiling tools available in your path. In this case,
4237 you must set the environment variable CROSS_COMPILE in your shell.
4238 Note that no changes to the Makefile or any other source files are
4239 necessary. For example using the ELDK on a 4xx CPU, please enter:
4241 $ CROSS_COMPILE=ppc_4xx-
4242 $ export CROSS_COMPILE
4244 Note: If you wish to generate Windows versions of the utilities in
4245 the tools directory you can use the MinGW toolchain
4246 (http://www.mingw.org). Set your HOST tools to the MinGW
4247 toolchain and execute 'make tools'. For example:
4249 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4251 Binaries such as tools/mkimage.exe will be created which can
4252 be executed on computers running Windows.
4254 U-Boot is intended to be simple to build. After installing the
4255 sources you must configure U-Boot for one specific board type. This
4260 where "NAME_defconfig" is the name of one of the existing configu-
4261 rations; see boards.cfg for supported names.
4263 Note: for some board special configuration names may exist; check if
4264 additional information is available from the board vendor; for
4265 instance, the TQM823L systems are available without (standard)
4266 or with LCD support. You can select such additional "features"
4267 when choosing the configuration, i. e.
4269 make TQM823L_defconfig
4270 - will configure for a plain TQM823L, i. e. no LCD support
4272 make TQM823L_LCD_defconfig
4273 - will configure for a TQM823L with U-Boot console on LCD
4278 Finally, type "make all", and you should get some working U-Boot
4279 images ready for download to / installation on your system:
4281 - "u-boot.bin" is a raw binary image
4282 - "u-boot" is an image in ELF binary format
4283 - "u-boot.srec" is in Motorola S-Record format
4285 By default the build is performed locally and the objects are saved
4286 in the source directory. One of the two methods can be used to change
4287 this behavior and build U-Boot to some external directory:
4289 1. Add O= to the make command line invocations:
4291 make O=/tmp/build distclean
4292 make O=/tmp/build NAME_defconfig
4293 make O=/tmp/build all
4295 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4297 export KBUILD_OUTPUT=/tmp/build
4302 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4306 Please be aware that the Makefiles assume you are using GNU make, so
4307 for instance on NetBSD you might need to use "gmake" instead of
4311 If the system board that you have is not listed, then you will need
4312 to port U-Boot to your hardware platform. To do this, follow these
4315 1. Create a new directory to hold your board specific code. Add any
4316 files you need. In your board directory, you will need at least
4317 the "Makefile" and a "<board>.c".
4318 2. Create a new configuration file "include/configs/<board>.h" for
4320 3. If you're porting U-Boot to a new CPU, then also create a new
4321 directory to hold your CPU specific code. Add any files you need.
4322 4. Run "make <board>_defconfig" with your new name.
4323 5. Type "make", and you should get a working "u-boot.srec" file
4324 to be installed on your target system.
4325 6. Debug and solve any problems that might arise.
4326 [Of course, this last step is much harder than it sounds.]
4329 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4330 ==============================================================
4332 If you have modified U-Boot sources (for instance added a new board
4333 or support for new devices, a new CPU, etc.) you are expected to
4334 provide feedback to the other developers. The feedback normally takes
4335 the form of a "patch", i. e. a context diff against a certain (latest
4336 official or latest in the git repository) version of U-Boot sources.
4338 But before you submit such a patch, please verify that your modifi-
4339 cation did not break existing code. At least make sure that *ALL* of
4340 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4341 just run the buildman script (tools/buildman/buildman), which will
4342 configure and build U-Boot for ALL supported system. Be warned, this
4343 will take a while. Please see the buildman README, or run 'buildman -H'
4347 See also "U-Boot Porting Guide" below.
4350 Monitor Commands - Overview:
4351 ============================
4353 go - start application at address 'addr'
4354 run - run commands in an environment variable
4355 bootm - boot application image from memory
4356 bootp - boot image via network using BootP/TFTP protocol
4357 bootz - boot zImage from memory
4358 tftpboot- boot image via network using TFTP protocol
4359 and env variables "ipaddr" and "serverip"
4360 (and eventually "gatewayip")
4361 tftpput - upload a file via network using TFTP protocol
4362 rarpboot- boot image via network using RARP/TFTP protocol
4363 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4364 loads - load S-Record file over serial line
4365 loadb - load binary file over serial line (kermit mode)
4367 mm - memory modify (auto-incrementing)
4368 nm - memory modify (constant address)
4369 mw - memory write (fill)
4371 cmp - memory compare
4372 crc32 - checksum calculation
4373 i2c - I2C sub-system
4374 sspi - SPI utility commands
4375 base - print or set address offset
4376 printenv- print environment variables
4377 setenv - set environment variables
4378 saveenv - save environment variables to persistent storage
4379 protect - enable or disable FLASH write protection
4380 erase - erase FLASH memory
4381 flinfo - print FLASH memory information
4382 nand - NAND memory operations (see doc/README.nand)
4383 bdinfo - print Board Info structure
4384 iminfo - print header information for application image
4385 coninfo - print console devices and informations
4386 ide - IDE sub-system
4387 loop - infinite loop on address range
4388 loopw - infinite write loop on address range
4389 mtest - simple RAM test
4390 icache - enable or disable instruction cache
4391 dcache - enable or disable data cache
4392 reset - Perform RESET of the CPU
4393 echo - echo args to console
4394 version - print monitor version
4395 help - print online help
4396 ? - alias for 'help'
4399 Monitor Commands - Detailed Description:
4400 ========================================
4404 For now: just type "help <command>".
4407 Environment Variables:
4408 ======================
4410 U-Boot supports user configuration using Environment Variables which
4411 can be made persistent by saving to Flash memory.
4413 Environment Variables are set using "setenv", printed using
4414 "printenv", and saved to Flash using "saveenv". Using "setenv"
4415 without a value can be used to delete a variable from the
4416 environment. As long as you don't save the environment you are
4417 working with an in-memory copy. In case the Flash area containing the
4418 environment is erased by accident, a default environment is provided.
4420 Some configuration options can be set using Environment Variables.
4422 List of environment variables (most likely not complete):
4424 baudrate - see CONFIG_BAUDRATE
4426 bootdelay - see CONFIG_BOOTDELAY
4428 bootcmd - see CONFIG_BOOTCOMMAND
4430 bootargs - Boot arguments when booting an RTOS image
4432 bootfile - Name of the image to load with TFTP
4434 bootm_low - Memory range available for image processing in the bootm
4435 command can be restricted. This variable is given as
4436 a hexadecimal number and defines lowest address allowed
4437 for use by the bootm command. See also "bootm_size"
4438 environment variable. Address defined by "bootm_low" is
4439 also the base of the initial memory mapping for the Linux
4440 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4443 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4444 This variable is given as a hexadecimal number and it
4445 defines the size of the memory region starting at base
4446 address bootm_low that is accessible by the Linux kernel
4447 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4448 as the default value if it is defined, and bootm_size is
4451 bootm_size - Memory range available for image processing in the bootm
4452 command can be restricted. This variable is given as
4453 a hexadecimal number and defines the size of the region
4454 allowed for use by the bootm command. See also "bootm_low"
4455 environment variable.
4457 updatefile - Location of the software update file on a TFTP server, used
4458 by the automatic software update feature. Please refer to
4459 documentation in doc/README.update for more details.
4461 autoload - if set to "no" (any string beginning with 'n'),
4462 "bootp" will just load perform a lookup of the
4463 configuration from the BOOTP server, but not try to
4464 load any image using TFTP
4466 autostart - if set to "yes", an image loaded using the "bootp",
4467 "rarpboot", "tftpboot" or "diskboot" commands will
4468 be automatically started (by internally calling
4471 If set to "no", a standalone image passed to the
4472 "bootm" command will be copied to the load address
4473 (and eventually uncompressed), but NOT be started.
4474 This can be used to load and uncompress arbitrary
4477 fdt_high - if set this restricts the maximum address that the
4478 flattened device tree will be copied into upon boot.
4479 For example, if you have a system with 1 GB memory
4480 at physical address 0x10000000, while Linux kernel
4481 only recognizes the first 704 MB as low memory, you
4482 may need to set fdt_high as 0x3C000000 to have the
4483 device tree blob be copied to the maximum address
4484 of the 704 MB low memory, so that Linux kernel can
4485 access it during the boot procedure.
4487 If this is set to the special value 0xFFFFFFFF then
4488 the fdt will not be copied at all on boot. For this
4489 to work it must reside in writable memory, have
4490 sufficient padding on the end of it for u-boot to
4491 add the information it needs into it, and the memory
4492 must be accessible by the kernel.
4494 fdtcontroladdr- if set this is the address of the control flattened
4495 device tree used by U-Boot when CONFIG_OF_CONTROL is
4498 i2cfast - (PPC405GP|PPC405EP only)
4499 if set to 'y' configures Linux I2C driver for fast
4500 mode (400kHZ). This environment variable is used in
4501 initialization code. So, for changes to be effective
4502 it must be saved and board must be reset.
4504 initrd_high - restrict positioning of initrd images:
4505 If this variable is not set, initrd images will be
4506 copied to the highest possible address in RAM; this
4507 is usually what you want since it allows for
4508 maximum initrd size. If for some reason you want to
4509 make sure that the initrd image is loaded below the
4510 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4511 variable to a value of "no" or "off" or "0".
4512 Alternatively, you can set it to a maximum upper
4513 address to use (U-Boot will still check that it
4514 does not overwrite the U-Boot stack and data).
4516 For instance, when you have a system with 16 MB
4517 RAM, and want to reserve 4 MB from use by Linux,
4518 you can do this by adding "mem=12M" to the value of
4519 the "bootargs" variable. However, now you must make
4520 sure that the initrd image is placed in the first
4521 12 MB as well - this can be done with
4523 setenv initrd_high 00c00000
4525 If you set initrd_high to 0xFFFFFFFF, this is an
4526 indication to U-Boot that all addresses are legal
4527 for the Linux kernel, including addresses in flash
4528 memory. In this case U-Boot will NOT COPY the
4529 ramdisk at all. This may be useful to reduce the
4530 boot time on your system, but requires that this
4531 feature is supported by your Linux kernel.
4533 ipaddr - IP address; needed for tftpboot command
4535 loadaddr - Default load address for commands like "bootp",
4536 "rarpboot", "tftpboot", "loadb" or "diskboot"
4538 loads_echo - see CONFIG_LOADS_ECHO
4540 serverip - TFTP server IP address; needed for tftpboot command
4542 bootretry - see CONFIG_BOOT_RETRY_TIME
4544 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4546 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4548 ethprime - controls which interface is used first.
4550 ethact - controls which interface is currently active.
4551 For example you can do the following
4553 => setenv ethact FEC
4554 => ping 192.168.0.1 # traffic sent on FEC
4555 => setenv ethact SCC
4556 => ping 10.0.0.1 # traffic sent on SCC
4558 ethrotate - When set to "no" U-Boot does not go through all
4559 available network interfaces.
4560 It just stays at the currently selected interface.
4562 netretry - When set to "no" each network operation will
4563 either succeed or fail without retrying.
4564 When set to "once" the network operation will
4565 fail when all the available network interfaces
4566 are tried once without success.
4567 Useful on scripts which control the retry operation
4570 npe_ucode - set load address for the NPE microcode
4572 silent_linux - If set then Linux will be told to boot silently, by
4573 changing the console to be empty. If "yes" it will be
4574 made silent. If "no" it will not be made silent. If
4575 unset, then it will be made silent if the U-Boot console
4578 tftpsrcp - If this is set, the value is used for TFTP's
4581 tftpdstp - If this is set, the value is used for TFTP's UDP
4582 destination port instead of the Well Know Port 69.
4584 tftpblocksize - Block size to use for TFTP transfers; if not set,
4585 we use the TFTP server's default block size
4587 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4588 seconds, minimum value is 1000 = 1 second). Defines
4589 when a packet is considered to be lost so it has to
4590 be retransmitted. The default is 5000 = 5 seconds.
4591 Lowering this value may make downloads succeed
4592 faster in networks with high packet loss rates or
4593 with unreliable TFTP servers.
4595 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4596 unit, minimum value = 0). Defines how many timeouts
4597 can happen during a single file transfer before that
4598 transfer is aborted. The default is 10, and 0 means
4599 'no timeouts allowed'. Increasing this value may help
4600 downloads succeed with high packet loss rates, or with
4601 unreliable TFTP servers or client hardware.
4603 vlan - When set to a value < 4095 the traffic over
4604 Ethernet is encapsulated/received over 802.1q
4607 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4608 Unsigned value, in milliseconds. If not set, the period will
4609 be either the default (28000), or a value based on
4610 CONFIG_NET_RETRY_COUNT, if defined. This value has
4611 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4613 The following image location variables contain the location of images
4614 used in booting. The "Image" column gives the role of the image and is
4615 not an environment variable name. The other columns are environment
4616 variable names. "File Name" gives the name of the file on a TFTP
4617 server, "RAM Address" gives the location in RAM the image will be
4618 loaded to, and "Flash Location" gives the image's address in NOR
4619 flash or offset in NAND flash.
4621 *Note* - these variables don't have to be defined for all boards, some
4622 boards currently use other variables for these purposes, and some
4623 boards use these variables for other purposes.
4625 Image File Name RAM Address Flash Location
4626 ----- --------- ----------- --------------
4627 u-boot u-boot u-boot_addr_r u-boot_addr
4628 Linux kernel bootfile kernel_addr_r kernel_addr
4629 device tree blob fdtfile fdt_addr_r fdt_addr
4630 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4632 The following environment variables may be used and automatically
4633 updated by the network boot commands ("bootp" and "rarpboot"),
4634 depending the information provided by your boot server:
4636 bootfile - see above
4637 dnsip - IP address of your Domain Name Server
4638 dnsip2 - IP address of your secondary Domain Name Server
4639 gatewayip - IP address of the Gateway (Router) to use
4640 hostname - Target hostname
4642 netmask - Subnet Mask
4643 rootpath - Pathname of the root filesystem on the NFS server
4644 serverip - see above
4647 There are two special Environment Variables:
4649 serial# - contains hardware identification information such
4650 as type string and/or serial number
4651 ethaddr - Ethernet address
4653 These variables can be set only once (usually during manufacturing of
4654 the board). U-Boot refuses to delete or overwrite these variables
4655 once they have been set once.
4658 Further special Environment Variables:
4660 ver - Contains the U-Boot version string as printed
4661 with the "version" command. This variable is
4662 readonly (see CONFIG_VERSION_VARIABLE).
4665 Please note that changes to some configuration parameters may take
4666 only effect after the next boot (yes, that's just like Windoze :-).
4669 Callback functions for environment variables:
4670 ---------------------------------------------
4672 For some environment variables, the behavior of u-boot needs to change
4673 when their values are changed. This functionality allows functions to
4674 be associated with arbitrary variables. On creation, overwrite, or
4675 deletion, the callback will provide the opportunity for some side
4676 effect to happen or for the change to be rejected.
4678 The callbacks are named and associated with a function using the
4679 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4681 These callbacks are associated with variables in one of two ways. The
4682 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4683 in the board configuration to a string that defines a list of
4684 associations. The list must be in the following format:
4686 entry = variable_name[:callback_name]
4689 If the callback name is not specified, then the callback is deleted.
4690 Spaces are also allowed anywhere in the list.
4692 Callbacks can also be associated by defining the ".callbacks" variable
4693 with the same list format above. Any association in ".callbacks" will
4694 override any association in the static list. You can define
4695 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4696 ".callbacks" environment variable in the default or embedded environment.
4698 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4699 regular expression. This allows multiple variables to be connected to
4700 the same callback without explicitly listing them all out.
4703 Command Line Parsing:
4704 =====================
4706 There are two different command line parsers available with U-Boot:
4707 the old "simple" one, and the much more powerful "hush" shell:
4709 Old, simple command line parser:
4710 --------------------------------
4712 - supports environment variables (through setenv / saveenv commands)
4713 - several commands on one line, separated by ';'
4714 - variable substitution using "... ${name} ..." syntax
4715 - special characters ('$', ';') can be escaped by prefixing with '\',
4717 setenv bootcmd bootm \${address}
4718 - You can also escape text by enclosing in single apostrophes, for example:
4719 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4724 - similar to Bourne shell, with control structures like
4725 if...then...else...fi, for...do...done; while...do...done,
4726 until...do...done, ...
4727 - supports environment ("global") variables (through setenv / saveenv
4728 commands) and local shell variables (through standard shell syntax
4729 "name=value"); only environment variables can be used with "run"
4735 (1) If a command line (or an environment variable executed by a "run"
4736 command) contains several commands separated by semicolon, and
4737 one of these commands fails, then the remaining commands will be
4740 (2) If you execute several variables with one call to run (i. e.
4741 calling run with a list of variables as arguments), any failing
4742 command will cause "run" to terminate, i. e. the remaining
4743 variables are not executed.
4745 Note for Redundant Ethernet Interfaces:
4746 =======================================
4748 Some boards come with redundant Ethernet interfaces; U-Boot supports
4749 such configurations and is capable of automatic selection of a
4750 "working" interface when needed. MAC assignment works as follows:
4752 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4753 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4754 "eth1addr" (=>eth1), "eth2addr", ...
4756 If the network interface stores some valid MAC address (for instance
4757 in SROM), this is used as default address if there is NO correspon-
4758 ding setting in the environment; if the corresponding environment
4759 variable is set, this overrides the settings in the card; that means:
4761 o If the SROM has a valid MAC address, and there is no address in the
4762 environment, the SROM's address is used.
4764 o If there is no valid address in the SROM, and a definition in the
4765 environment exists, then the value from the environment variable is
4768 o If both the SROM and the environment contain a MAC address, and
4769 both addresses are the same, this MAC address is used.
4771 o If both the SROM and the environment contain a MAC address, and the
4772 addresses differ, the value from the environment is used and a
4775 o If neither SROM nor the environment contain a MAC address, an error
4776 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4777 a random, locally-assigned MAC is used.
4779 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4780 will be programmed into hardware as part of the initialization process. This
4781 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4782 The naming convention is as follows:
4783 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4788 U-Boot is capable of booting (and performing other auxiliary operations on)
4789 images in two formats:
4791 New uImage format (FIT)
4792 -----------------------
4794 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4795 to Flattened Device Tree). It allows the use of images with multiple
4796 components (several kernels, ramdisks, etc.), with contents protected by
4797 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4803 Old image format is based on binary files which can be basically anything,
4804 preceded by a special header; see the definitions in include/image.h for
4805 details; basically, the header defines the following image properties:
4807 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4808 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4809 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4810 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4812 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4813 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4814 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4815 * Compression Type (uncompressed, gzip, bzip2)
4821 The header is marked by a special Magic Number, and both the header
4822 and the data portions of the image are secured against corruption by
4829 Although U-Boot should support any OS or standalone application
4830 easily, the main focus has always been on Linux during the design of
4833 U-Boot includes many features that so far have been part of some
4834 special "boot loader" code within the Linux kernel. Also, any
4835 "initrd" images to be used are no longer part of one big Linux image;
4836 instead, kernel and "initrd" are separate images. This implementation
4837 serves several purposes:
4839 - the same features can be used for other OS or standalone
4840 applications (for instance: using compressed images to reduce the
4841 Flash memory footprint)
4843 - it becomes much easier to port new Linux kernel versions because
4844 lots of low-level, hardware dependent stuff are done by U-Boot
4846 - the same Linux kernel image can now be used with different "initrd"
4847 images; of course this also means that different kernel images can
4848 be run with the same "initrd". This makes testing easier (you don't
4849 have to build a new "zImage.initrd" Linux image when you just
4850 change a file in your "initrd"). Also, a field-upgrade of the
4851 software is easier now.
4857 Porting Linux to U-Boot based systems:
4858 ---------------------------------------
4860 U-Boot cannot save you from doing all the necessary modifications to
4861 configure the Linux device drivers for use with your target hardware
4862 (no, we don't intend to provide a full virtual machine interface to
4865 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4867 Just make sure your machine specific header file (for instance
4868 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4869 Information structure as we define in include/asm-<arch>/u-boot.h,
4870 and make sure that your definition of IMAP_ADDR uses the same value
4871 as your U-Boot configuration in CONFIG_SYS_IMMR.
4873 Note that U-Boot now has a driver model, a unified model for drivers.
4874 If you are adding a new driver, plumb it into driver model. If there
4875 is no uclass available, you are encouraged to create one. See
4879 Configuring the Linux kernel:
4880 -----------------------------
4882 No specific requirements for U-Boot. Make sure you have some root
4883 device (initial ramdisk, NFS) for your target system.
4886 Building a Linux Image:
4887 -----------------------
4889 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4890 not used. If you use recent kernel source, a new build target
4891 "uImage" will exist which automatically builds an image usable by
4892 U-Boot. Most older kernels also have support for a "pImage" target,
4893 which was introduced for our predecessor project PPCBoot and uses a
4894 100% compatible format.
4898 make TQM850L_defconfig
4903 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4904 encapsulate a compressed Linux kernel image with header information,
4905 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4907 * build a standard "vmlinux" kernel image (in ELF binary format):
4909 * convert the kernel into a raw binary image:
4911 ${CROSS_COMPILE}-objcopy -O binary \
4912 -R .note -R .comment \
4913 -S vmlinux linux.bin
4915 * compress the binary image:
4919 * package compressed binary image for U-Boot:
4921 mkimage -A ppc -O linux -T kernel -C gzip \
4922 -a 0 -e 0 -n "Linux Kernel Image" \
4923 -d linux.bin.gz uImage
4926 The "mkimage" tool can also be used to create ramdisk images for use
4927 with U-Boot, either separated from the Linux kernel image, or
4928 combined into one file. "mkimage" encapsulates the images with a 64
4929 byte header containing information about target architecture,
4930 operating system, image type, compression method, entry points, time
4931 stamp, CRC32 checksums, etc.
4933 "mkimage" can be called in two ways: to verify existing images and
4934 print the header information, or to build new images.
4936 In the first form (with "-l" option) mkimage lists the information
4937 contained in the header of an existing U-Boot image; this includes
4938 checksum verification:
4940 tools/mkimage -l image
4941 -l ==> list image header information
4943 The second form (with "-d" option) is used to build a U-Boot image
4944 from a "data file" which is used as image payload:
4946 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4947 -n name -d data_file image
4948 -A ==> set architecture to 'arch'
4949 -O ==> set operating system to 'os'
4950 -T ==> set image type to 'type'
4951 -C ==> set compression type 'comp'
4952 -a ==> set load address to 'addr' (hex)
4953 -e ==> set entry point to 'ep' (hex)
4954 -n ==> set image name to 'name'
4955 -d ==> use image data from 'datafile'
4957 Right now, all Linux kernels for PowerPC systems use the same load
4958 address (0x00000000), but the entry point address depends on the
4961 - 2.2.x kernels have the entry point at 0x0000000C,
4962 - 2.3.x and later kernels have the entry point at 0x00000000.
4964 So a typical call to build a U-Boot image would read:
4966 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4967 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4968 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4969 > examples/uImage.TQM850L
4970 Image Name: 2.4.4 kernel for TQM850L
4971 Created: Wed Jul 19 02:34:59 2000
4972 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4973 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4974 Load Address: 0x00000000
4975 Entry Point: 0x00000000
4977 To verify the contents of the image (or check for corruption):
4979 -> tools/mkimage -l examples/uImage.TQM850L
4980 Image Name: 2.4.4 kernel for TQM850L
4981 Created: Wed Jul 19 02:34:59 2000
4982 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4983 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4984 Load Address: 0x00000000
4985 Entry Point: 0x00000000
4987 NOTE: for embedded systems where boot time is critical you can trade
4988 speed for memory and install an UNCOMPRESSED image instead: this
4989 needs more space in Flash, but boots much faster since it does not
4990 need to be uncompressed:
4992 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4993 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4994 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4995 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4996 > examples/uImage.TQM850L-uncompressed
4997 Image Name: 2.4.4 kernel for TQM850L
4998 Created: Wed Jul 19 02:34:59 2000
4999 Image Type: PowerPC Linux Kernel Image (uncompressed)
5000 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5001 Load Address: 0x00000000
5002 Entry Point: 0x00000000
5005 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5006 when your kernel is intended to use an initial ramdisk:
5008 -> tools/mkimage -n 'Simple Ramdisk Image' \
5009 > -A ppc -O linux -T ramdisk -C gzip \
5010 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5011 Image Name: Simple Ramdisk Image
5012 Created: Wed Jan 12 14:01:50 2000
5013 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5014 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5015 Load Address: 0x00000000
5016 Entry Point: 0x00000000
5018 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5019 option performs the converse operation of the mkimage's second form (the "-d"
5020 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5023 tools/dumpimage -i image -T type -p position data_file
5024 -i ==> extract from the 'image' a specific 'data_file'
5025 -T ==> set image type to 'type'
5026 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5029 Installing a Linux Image:
5030 -------------------------
5032 To downloading a U-Boot image over the serial (console) interface,
5033 you must convert the image to S-Record format:
5035 objcopy -I binary -O srec examples/image examples/image.srec
5037 The 'objcopy' does not understand the information in the U-Boot
5038 image header, so the resulting S-Record file will be relative to
5039 address 0x00000000. To load it to a given address, you need to
5040 specify the target address as 'offset' parameter with the 'loads'
5043 Example: install the image to address 0x40100000 (which on the
5044 TQM8xxL is in the first Flash bank):
5046 => erase 40100000 401FFFFF
5052 ## Ready for S-Record download ...
5053 ~>examples/image.srec
5054 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5056 15989 15990 15991 15992
5057 [file transfer complete]
5059 ## Start Addr = 0x00000000
5062 You can check the success of the download using the 'iminfo' command;
5063 this includes a checksum verification so you can be sure no data
5064 corruption happened:
5068 ## Checking Image at 40100000 ...
5069 Image Name: 2.2.13 for initrd on TQM850L
5070 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5071 Data Size: 335725 Bytes = 327 kB = 0 MB
5072 Load Address: 00000000
5073 Entry Point: 0000000c
5074 Verifying Checksum ... OK
5080 The "bootm" command is used to boot an application that is stored in
5081 memory (RAM or Flash). In case of a Linux kernel image, the contents
5082 of the "bootargs" environment variable is passed to the kernel as
5083 parameters. You can check and modify this variable using the
5084 "printenv" and "setenv" commands:
5087 => printenv bootargs
5088 bootargs=root=/dev/ram
5090 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5092 => printenv bootargs
5093 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5096 ## Booting Linux kernel at 40020000 ...
5097 Image Name: 2.2.13 for NFS on TQM850L
5098 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5099 Data Size: 381681 Bytes = 372 kB = 0 MB
5100 Load Address: 00000000
5101 Entry Point: 0000000c
5102 Verifying Checksum ... OK
5103 Uncompressing Kernel Image ... OK
5104 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
5105 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5106 time_init: decrementer frequency = 187500000/60
5107 Calibrating delay loop... 49.77 BogoMIPS
5108 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5111 If you want to boot a Linux kernel with initial RAM disk, you pass
5112 the memory addresses of both the kernel and the initrd image (PPBCOOT
5113 format!) to the "bootm" command:
5115 => imi 40100000 40200000
5117 ## Checking Image at 40100000 ...
5118 Image Name: 2.2.13 for initrd on TQM850L
5119 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5120 Data Size: 335725 Bytes = 327 kB = 0 MB
5121 Load Address: 00000000
5122 Entry Point: 0000000c
5123 Verifying Checksum ... OK
5125 ## Checking Image at 40200000 ...
5126 Image Name: Simple Ramdisk Image
5127 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5128 Data Size: 566530 Bytes = 553 kB = 0 MB
5129 Load Address: 00000000
5130 Entry Point: 00000000
5131 Verifying Checksum ... OK
5133 => bootm 40100000 40200000
5134 ## Booting Linux kernel at 40100000 ...
5135 Image Name: 2.2.13 for initrd on TQM850L
5136 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5137 Data Size: 335725 Bytes = 327 kB = 0 MB
5138 Load Address: 00000000
5139 Entry Point: 0000000c
5140 Verifying Checksum ... OK
5141 Uncompressing Kernel Image ... OK
5142 ## Loading RAMDisk Image at 40200000 ...
5143 Image Name: Simple Ramdisk Image
5144 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5145 Data Size: 566530 Bytes = 553 kB = 0 MB
5146 Load Address: 00000000
5147 Entry Point: 00000000
5148 Verifying Checksum ... OK
5149 Loading Ramdisk ... OK
5150 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
5151 Boot arguments: root=/dev/ram
5152 time_init: decrementer frequency = 187500000/60
5153 Calibrating delay loop... 49.77 BogoMIPS
5155 RAMDISK: Compressed image found at block 0
5156 VFS: Mounted root (ext2 filesystem).
5160 Boot Linux and pass a flat device tree:
5163 First, U-Boot must be compiled with the appropriate defines. See the section
5164 titled "Linux Kernel Interface" above for a more in depth explanation. The
5165 following is an example of how to start a kernel and pass an updated
5171 oft=oftrees/mpc8540ads.dtb
5172 => tftp $oftaddr $oft
5173 Speed: 1000, full duplex
5175 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5176 Filename 'oftrees/mpc8540ads.dtb'.
5177 Load address: 0x300000
5180 Bytes transferred = 4106 (100a hex)
5181 => tftp $loadaddr $bootfile
5182 Speed: 1000, full duplex
5184 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5186 Load address: 0x200000
5187 Loading:############
5189 Bytes transferred = 1029407 (fb51f hex)
5194 => bootm $loadaddr - $oftaddr
5195 ## Booting image at 00200000 ...
5196 Image Name: Linux-2.6.17-dirty
5197 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5198 Data Size: 1029343 Bytes = 1005.2 kB
5199 Load Address: 00000000
5200 Entry Point: 00000000
5201 Verifying Checksum ... OK
5202 Uncompressing Kernel Image ... OK
5203 Booting using flat device tree at 0x300000
5204 Using MPC85xx ADS machine description
5205 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5209 More About U-Boot Image Types:
5210 ------------------------------
5212 U-Boot supports the following image types:
5214 "Standalone Programs" are directly runnable in the environment
5215 provided by U-Boot; it is expected that (if they behave
5216 well) you can continue to work in U-Boot after return from
5217 the Standalone Program.
5218 "OS Kernel Images" are usually images of some Embedded OS which
5219 will take over control completely. Usually these programs
5220 will install their own set of exception handlers, device
5221 drivers, set up the MMU, etc. - this means, that you cannot
5222 expect to re-enter U-Boot except by resetting the CPU.
5223 "RAMDisk Images" are more or less just data blocks, and their
5224 parameters (address, size) are passed to an OS kernel that is
5226 "Multi-File Images" contain several images, typically an OS
5227 (Linux) kernel image and one or more data images like
5228 RAMDisks. This construct is useful for instance when you want
5229 to boot over the network using BOOTP etc., where the boot
5230 server provides just a single image file, but you want to get
5231 for instance an OS kernel and a RAMDisk image.
5233 "Multi-File Images" start with a list of image sizes, each
5234 image size (in bytes) specified by an "uint32_t" in network
5235 byte order. This list is terminated by an "(uint32_t)0".
5236 Immediately after the terminating 0 follow the images, one by
5237 one, all aligned on "uint32_t" boundaries (size rounded up to
5238 a multiple of 4 bytes).
5240 "Firmware Images" are binary images containing firmware (like
5241 U-Boot or FPGA images) which usually will be programmed to
5244 "Script files" are command sequences that will be executed by
5245 U-Boot's command interpreter; this feature is especially
5246 useful when you configure U-Boot to use a real shell (hush)
5247 as command interpreter.
5249 Booting the Linux zImage:
5250 -------------------------
5252 On some platforms, it's possible to boot Linux zImage. This is done
5253 using the "bootz" command. The syntax of "bootz" command is the same
5254 as the syntax of "bootm" command.
5256 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5257 kernel with raw initrd images. The syntax is slightly different, the
5258 address of the initrd must be augmented by it's size, in the following
5259 format: "<initrd addres>:<initrd size>".
5265 One of the features of U-Boot is that you can dynamically load and
5266 run "standalone" applications, which can use some resources of
5267 U-Boot like console I/O functions or interrupt services.
5269 Two simple examples are included with the sources:
5274 'examples/hello_world.c' contains a small "Hello World" Demo
5275 application; it is automatically compiled when you build U-Boot.
5276 It's configured to run at address 0x00040004, so you can play with it
5280 ## Ready for S-Record download ...
5281 ~>examples/hello_world.srec
5282 1 2 3 4 5 6 7 8 9 10 11 ...
5283 [file transfer complete]
5285 ## Start Addr = 0x00040004
5287 => go 40004 Hello World! This is a test.
5288 ## Starting application at 0x00040004 ...
5299 Hit any key to exit ...
5301 ## Application terminated, rc = 0x0
5303 Another example, which demonstrates how to register a CPM interrupt
5304 handler with the U-Boot code, can be found in 'examples/timer.c'.
5305 Here, a CPM timer is set up to generate an interrupt every second.
5306 The interrupt service routine is trivial, just printing a '.'
5307 character, but this is just a demo program. The application can be
5308 controlled by the following keys:
5310 ? - print current values og the CPM Timer registers
5311 b - enable interrupts and start timer
5312 e - stop timer and disable interrupts
5313 q - quit application
5316 ## Ready for S-Record download ...
5317 ~>examples/timer.srec
5318 1 2 3 4 5 6 7 8 9 10 11 ...
5319 [file transfer complete]
5321 ## Start Addr = 0x00040004
5324 ## Starting application at 0x00040004 ...
5327 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5330 [q, b, e, ?] Set interval 1000000 us
5333 [q, b, e, ?] ........
5334 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5337 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5340 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5343 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5345 [q, b, e, ?] ...Stopping timer
5347 [q, b, e, ?] ## Application terminated, rc = 0x0
5353 Over time, many people have reported problems when trying to use the
5354 "minicom" terminal emulation program for serial download. I (wd)
5355 consider minicom to be broken, and recommend not to use it. Under
5356 Unix, I recommend to use C-Kermit for general purpose use (and
5357 especially for kermit binary protocol download ("loadb" command), and
5358 use "cu" for S-Record download ("loads" command). See
5359 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5360 for help with kermit.
5363 Nevertheless, if you absolutely want to use it try adding this
5364 configuration to your "File transfer protocols" section:
5366 Name Program Name U/D FullScr IO-Red. Multi
5367 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5368 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5374 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5375 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5377 Building requires a cross environment; it is known to work on
5378 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5379 need gmake since the Makefiles are not compatible with BSD make).
5380 Note that the cross-powerpc package does not install include files;
5381 attempting to build U-Boot will fail because <machine/ansi.h> is
5382 missing. This file has to be installed and patched manually:
5384 # cd /usr/pkg/cross/powerpc-netbsd/include
5386 # ln -s powerpc machine
5387 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5388 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5390 Native builds *don't* work due to incompatibilities between native
5391 and U-Boot include files.
5393 Booting assumes that (the first part of) the image booted is a
5394 stage-2 loader which in turn loads and then invokes the kernel
5395 proper. Loader sources will eventually appear in the NetBSD source
5396 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5397 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5400 Implementation Internals:
5401 =========================
5403 The following is not intended to be a complete description of every
5404 implementation detail. However, it should help to understand the
5405 inner workings of U-Boot and make it easier to port it to custom
5409 Initial Stack, Global Data:
5410 ---------------------------
5412 The implementation of U-Boot is complicated by the fact that U-Boot
5413 starts running out of ROM (flash memory), usually without access to
5414 system RAM (because the memory controller is not initialized yet).
5415 This means that we don't have writable Data or BSS segments, and BSS
5416 is not initialized as zero. To be able to get a C environment working
5417 at all, we have to allocate at least a minimal stack. Implementation
5418 options for this are defined and restricted by the CPU used: Some CPU
5419 models provide on-chip memory (like the IMMR area on MPC8xx and
5420 MPC826x processors), on others (parts of) the data cache can be
5421 locked as (mis-) used as memory, etc.
5423 Chris Hallinan posted a good summary of these issues to the
5424 U-Boot mailing list:
5426 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5427 From: "Chris Hallinan" <clh@net1plus.com>
5428 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5431 Correct me if I'm wrong, folks, but the way I understand it
5432 is this: Using DCACHE as initial RAM for Stack, etc, does not
5433 require any physical RAM backing up the cache. The cleverness
5434 is that the cache is being used as a temporary supply of
5435 necessary storage before the SDRAM controller is setup. It's
5436 beyond the scope of this list to explain the details, but you
5437 can see how this works by studying the cache architecture and
5438 operation in the architecture and processor-specific manuals.
5440 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5441 is another option for the system designer to use as an
5442 initial stack/RAM area prior to SDRAM being available. Either
5443 option should work for you. Using CS 4 should be fine if your
5444 board designers haven't used it for something that would
5445 cause you grief during the initial boot! It is frequently not
5448 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5449 with your processor/board/system design. The default value
5450 you will find in any recent u-boot distribution in
5451 walnut.h should work for you. I'd set it to a value larger
5452 than your SDRAM module. If you have a 64MB SDRAM module, set
5453 it above 400_0000. Just make sure your board has no resources
5454 that are supposed to respond to that address! That code in
5455 start.S has been around a while and should work as is when
5456 you get the config right.
5461 It is essential to remember this, since it has some impact on the C
5462 code for the initialization procedures:
5464 * Initialized global data (data segment) is read-only. Do not attempt
5467 * Do not use any uninitialized global data (or implicitly initialized
5468 as zero data - BSS segment) at all - this is undefined, initiali-
5469 zation is performed later (when relocating to RAM).
5471 * Stack space is very limited. Avoid big data buffers or things like
5474 Having only the stack as writable memory limits means we cannot use
5475 normal global data to share information between the code. But it
5476 turned out that the implementation of U-Boot can be greatly
5477 simplified by making a global data structure (gd_t) available to all
5478 functions. We could pass a pointer to this data as argument to _all_
5479 functions, but this would bloat the code. Instead we use a feature of
5480 the GCC compiler (Global Register Variables) to share the data: we
5481 place a pointer (gd) to the global data into a register which we
5482 reserve for this purpose.
5484 When choosing a register for such a purpose we are restricted by the
5485 relevant (E)ABI specifications for the current architecture, and by
5486 GCC's implementation.
5488 For PowerPC, the following registers have specific use:
5490 R2: reserved for system use
5491 R3-R4: parameter passing and return values
5492 R5-R10: parameter passing
5493 R13: small data area pointer
5497 (U-Boot also uses R12 as internal GOT pointer. r12
5498 is a volatile register so r12 needs to be reset when
5499 going back and forth between asm and C)
5501 ==> U-Boot will use R2 to hold a pointer to the global data
5503 Note: on PPC, we could use a static initializer (since the
5504 address of the global data structure is known at compile time),
5505 but it turned out that reserving a register results in somewhat
5506 smaller code - although the code savings are not that big (on
5507 average for all boards 752 bytes for the whole U-Boot image,
5508 624 text + 127 data).
5510 On ARM, the following registers are used:
5512 R0: function argument word/integer result
5513 R1-R3: function argument word
5514 R9: platform specific
5515 R10: stack limit (used only if stack checking is enabled)
5516 R11: argument (frame) pointer
5517 R12: temporary workspace
5520 R15: program counter
5522 ==> U-Boot will use R9 to hold a pointer to the global data
5524 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5526 On Nios II, the ABI is documented here:
5527 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5529 ==> U-Boot will use gp to hold a pointer to the global data
5531 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5532 to access small data sections, so gp is free.
5534 On NDS32, the following registers are used:
5536 R0-R1: argument/return
5538 R15: temporary register for assembler
5539 R16: trampoline register
5540 R28: frame pointer (FP)
5541 R29: global pointer (GP)
5542 R30: link register (LP)
5543 R31: stack pointer (SP)
5544 PC: program counter (PC)
5546 ==> U-Boot will use R10 to hold a pointer to the global data
5548 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5549 or current versions of GCC may "optimize" the code too much.
5554 U-Boot runs in system state and uses physical addresses, i.e. the
5555 MMU is not used either for address mapping nor for memory protection.
5557 The available memory is mapped to fixed addresses using the memory
5558 controller. In this process, a contiguous block is formed for each
5559 memory type (Flash, SDRAM, SRAM), even when it consists of several
5560 physical memory banks.
5562 U-Boot is installed in the first 128 kB of the first Flash bank (on
5563 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5564 booting and sizing and initializing DRAM, the code relocates itself
5565 to the upper end of DRAM. Immediately below the U-Boot code some
5566 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5567 configuration setting]. Below that, a structure with global Board
5568 Info data is placed, followed by the stack (growing downward).
5570 Additionally, some exception handler code is copied to the low 8 kB
5571 of DRAM (0x00000000 ... 0x00001FFF).
5573 So a typical memory configuration with 16 MB of DRAM could look like
5576 0x0000 0000 Exception Vector code
5579 0x0000 2000 Free for Application Use
5585 0x00FB FF20 Monitor Stack (Growing downward)
5586 0x00FB FFAC Board Info Data and permanent copy of global data
5587 0x00FC 0000 Malloc Arena
5590 0x00FE 0000 RAM Copy of Monitor Code
5591 ... eventually: LCD or video framebuffer
5592 ... eventually: pRAM (Protected RAM - unchanged by reset)
5593 0x00FF FFFF [End of RAM]
5596 System Initialization:
5597 ----------------------
5599 In the reset configuration, U-Boot starts at the reset entry point
5600 (on most PowerPC systems at address 0x00000100). Because of the reset
5601 configuration for CS0# this is a mirror of the on board Flash memory.
5602 To be able to re-map memory U-Boot then jumps to its link address.
5603 To be able to implement the initialization code in C, a (small!)
5604 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5605 which provide such a feature like), or in a locked part of the data
5606 cache. After that, U-Boot initializes the CPU core, the caches and
5609 Next, all (potentially) available memory banks are mapped using a
5610 preliminary mapping. For example, we put them on 512 MB boundaries
5611 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5612 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5613 programmed for SDRAM access. Using the temporary configuration, a
5614 simple memory test is run that determines the size of the SDRAM
5617 When there is more than one SDRAM bank, and the banks are of
5618 different size, the largest is mapped first. For equal size, the first
5619 bank (CS2#) is mapped first. The first mapping is always for address
5620 0x00000000, with any additional banks following immediately to create
5621 contiguous memory starting from 0.
5623 Then, the monitor installs itself at the upper end of the SDRAM area
5624 and allocates memory for use by malloc() and for the global Board
5625 Info data; also, the exception vector code is copied to the low RAM
5626 pages, and the final stack is set up.
5628 Only after this relocation will you have a "normal" C environment;
5629 until that you are restricted in several ways, mostly because you are
5630 running from ROM, and because the code will have to be relocated to a
5634 U-Boot Porting Guide:
5635 ----------------------
5637 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5641 int main(int argc, char *argv[])
5643 sighandler_t no_more_time;
5645 signal(SIGALRM, no_more_time);
5646 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5648 if (available_money > available_manpower) {
5649 Pay consultant to port U-Boot;
5653 Download latest U-Boot source;
5655 Subscribe to u-boot mailing list;
5658 email("Hi, I am new to U-Boot, how do I get started?");
5661 Read the README file in the top level directory;
5662 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5663 Read applicable doc/*.README;
5664 Read the source, Luke;
5665 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5668 if (available_money > toLocalCurrency ($2500))
5671 Add a lot of aggravation and time;
5673 if (a similar board exists) { /* hopefully... */
5674 cp -a board/<similar> board/<myboard>
5675 cp include/configs/<similar>.h include/configs/<myboard>.h
5677 Create your own board support subdirectory;
5678 Create your own board include/configs/<myboard>.h file;
5680 Edit new board/<myboard> files
5681 Edit new include/configs/<myboard>.h
5686 Add / modify source code;
5690 email("Hi, I am having problems...");
5692 Send patch file to the U-Boot email list;
5693 if (reasonable critiques)
5694 Incorporate improvements from email list code review;
5696 Defend code as written;
5702 void no_more_time (int sig)
5711 All contributions to U-Boot should conform to the Linux kernel
5712 coding style; see the file "Documentation/CodingStyle" and the script
5713 "scripts/Lindent" in your Linux kernel source directory.
5715 Source files originating from a different project (for example the
5716 MTD subsystem) are generally exempt from these guidelines and are not
5717 reformatted to ease subsequent migration to newer versions of those
5720 Please note that U-Boot is implemented in C (and to some small parts in
5721 Assembler); no C++ is used, so please do not use C++ style comments (//)
5724 Please also stick to the following formatting rules:
5725 - remove any trailing white space
5726 - use TAB characters for indentation and vertical alignment, not spaces
5727 - make sure NOT to use DOS '\r\n' line feeds
5728 - do not add more than 2 consecutive empty lines to source files
5729 - do not add trailing empty lines to source files
5731 Submissions which do not conform to the standards may be returned
5732 with a request to reformat the changes.
5738 Since the number of patches for U-Boot is growing, we need to
5739 establish some rules. Submissions which do not conform to these rules
5740 may be rejected, even when they contain important and valuable stuff.
5742 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5744 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5745 see http://lists.denx.de/mailman/listinfo/u-boot
5747 When you send a patch, please include the following information with
5750 * For bug fixes: a description of the bug and how your patch fixes
5751 this bug. Please try to include a way of demonstrating that the
5752 patch actually fixes something.
5754 * For new features: a description of the feature and your
5757 * A CHANGELOG entry as plaintext (separate from the patch)
5759 * For major contributions, add a MAINTAINERS file with your
5760 information and associated file and directory references.
5762 * When you add support for a new board, don't forget to add a
5763 maintainer e-mail address to the boards.cfg file, too.
5765 * If your patch adds new configuration options, don't forget to
5766 document these in the README file.
5768 * The patch itself. If you are using git (which is *strongly*
5769 recommended) you can easily generate the patch using the
5770 "git format-patch". If you then use "git send-email" to send it to
5771 the U-Boot mailing list, you will avoid most of the common problems
5772 with some other mail clients.
5774 If you cannot use git, use "diff -purN OLD NEW". If your version of
5775 diff does not support these options, then get the latest version of
5778 The current directory when running this command shall be the parent
5779 directory of the U-Boot source tree (i. e. please make sure that
5780 your patch includes sufficient directory information for the
5783 We prefer patches as plain text. MIME attachments are discouraged,
5784 and compressed attachments must not be used.
5786 * If one logical set of modifications affects or creates several
5787 files, all these changes shall be submitted in a SINGLE patch file.
5789 * Changesets that contain different, unrelated modifications shall be
5790 submitted as SEPARATE patches, one patch per changeset.
5795 * Before sending the patch, run the buildman script on your patched
5796 source tree and make sure that no errors or warnings are reported
5797 for any of the boards.
5799 * Keep your modifications to the necessary minimum: A patch
5800 containing several unrelated changes or arbitrary reformats will be
5801 returned with a request to re-formatting / split it.
5803 * If you modify existing code, make sure that your new code does not
5804 add to the memory footprint of the code ;-) Small is beautiful!
5805 When adding new features, these should compile conditionally only
5806 (using #ifdef), and the resulting code with the new feature
5807 disabled must not need more memory than the old code without your
5810 * Remember that there is a size limit of 100 kB per message on the
5811 u-boot mailing list. Bigger patches will be moderated. If they are
5812 reasonable and not too big, they will be acknowledged. But patches
5813 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob