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 The default command configuration includes all commands
761 except those marked below with a "*".
763 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
764 CONFIG_CMD_ASKENV * ask for env variable
765 CONFIG_CMD_BDI bdinfo
766 CONFIG_CMD_BOOTD bootd
767 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
768 CONFIG_CMD_CACHE * icache, dcache
769 CONFIG_CMD_CONSOLE coninfo
770 CONFIG_CMD_DHCP * DHCP support
771 CONFIG_CMD_DIAG * Diagnostics
772 CONFIG_CMD_ECHO echo arguments
773 CONFIG_CMD_EDITENV edit env variable
774 CONFIG_CMD_ELF * bootelf, bootvx
775 CONFIG_CMD_ENV_EXISTS * check existence of env variable
776 CONFIG_CMD_EXPORTENV * export the environment
777 CONFIG_CMD_EXT2 * ext2 command support
778 CONFIG_CMD_EXT4 * ext4 command support
779 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
780 that work for multiple fs types
781 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
782 CONFIG_CMD_SAVEENV saveenv
783 CONFIG_CMD_FLASH flinfo, erase, protect
784 CONFIG_CMD_FPGA FPGA device initialization support
785 CONFIG_CMD_GO * the 'go' command (exec code)
786 CONFIG_CMD_GREPENV * search environment
787 CONFIG_CMD_I2C * I2C serial bus support
788 CONFIG_CMD_IMI iminfo
789 CONFIG_CMD_IMLS List all images found in NOR flash
790 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
791 CONFIG_CMD_IMPORTENV * import an environment
792 CONFIG_CMD_INI * import data from an ini file into the env
793 CONFIG_CMD_ITEST Integer/string test of 2 values
794 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
795 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
797 CONFIG_CMD_LOADB loadb
798 CONFIG_CMD_LOADS loads
799 CONFIG_CMD_MD5SUM * print md5 message digest
800 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
801 CONFIG_CMD_MEMINFO * Display detailed memory information
802 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
804 CONFIG_CMD_MEMTEST * mtest
805 CONFIG_CMD_MISC Misc functions like sleep etc
806 CONFIG_CMD_MMC * MMC memory mapped support
807 CONFIG_CMD_MII * MII utility commands
808 CONFIG_CMD_NET bootp, tftpboot, rarpboot
809 CONFIG_CMD_NFS NFS support
810 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
812 CONFIG_CMD_RUN run command in env variable
813 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
814 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
815 CONFIG_CMD_SOURCE "source" command Support
816 CONFIG_CMD_SPI * SPI serial bus support
817 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
818 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
819 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
820 CONFIG_CMD_TIMER * access to the system tick timer
821 CONFIG_CMD_USB * USB support
822 CONFIG_CMD_CDP * Cisco Discover Protocol support
823 CONFIG_CMD_XIMG Load part of Multi Image
825 EXAMPLE: If you want all functions except of network
826 support you can write:
828 #include "config_cmd_all.h"
829 #undef CONFIG_CMD_NET
832 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
834 Note: Don't enable the "icache" and "dcache" commands
835 (configuration option CONFIG_CMD_CACHE) unless you know
836 what you (and your U-Boot users) are doing. Data
837 cache cannot be enabled on systems like the
838 8xx (where accesses to the IMMR region must be
839 uncached), and it cannot be disabled on all other
840 systems where we (mis-) use the data cache to hold an
841 initial stack and some data.
844 XXX - this list needs to get updated!
846 - Removal of commands
847 If no commands are needed to boot, you can disable
848 CONFIG_CMDLINE to remove them. In this case, the command line
849 will not be available, and when U-Boot wants to execute the
850 boot command (on start-up) it will call board_run_command()
851 instead. This can reduce image size significantly for very
852 simple boot procedures.
854 - Regular expression support:
856 If this variable is defined, U-Boot is linked against
857 the SLRE (Super Light Regular Expression) library,
858 which adds regex support to some commands, as for
859 example "env grep" and "setexpr".
863 If this variable is defined, U-Boot will use a device tree
864 to configure its devices, instead of relying on statically
865 compiled #defines in the board file. This option is
866 experimental and only available on a few boards. The device
867 tree is available in the global data as gd->fdt_blob.
869 U-Boot needs to get its device tree from somewhere. This can
870 be done using one of the three options below:
873 If this variable is defined, U-Boot will embed a device tree
874 binary in its image. This device tree file should be in the
875 board directory and called <soc>-<board>.dts. The binary file
876 is then picked up in board_init_f() and made available through
877 the global data structure as gd->blob.
880 If this variable is defined, U-Boot will build a device tree
881 binary. It will be called u-boot.dtb. Architecture-specific
882 code will locate it at run-time. Generally this works by:
884 cat u-boot.bin u-boot.dtb >image.bin
886 and in fact, U-Boot does this for you, creating a file called
887 u-boot-dtb.bin which is useful in the common case. You can
888 still use the individual files if you need something more
892 If this variable is defined, U-Boot will use the device tree
893 provided by the board at runtime instead of embedding one with
894 the image. Only boards defining board_fdt_blob_setup() support
895 this option (see include/fdtdec.h file).
899 If this variable is defined, it enables watchdog
900 support for the SoC. There must be support in the SoC
901 specific code for a watchdog. For the 8xx
902 CPUs, the SIU Watchdog feature is enabled in the SYPCR
903 register. When supported for a specific SoC is
904 available, then no further board specific code should
908 When using a watchdog circuitry external to the used
909 SoC, then define this variable and provide board
910 specific code for the "hw_watchdog_reset" function.
912 CONFIG_AT91_HW_WDT_TIMEOUT
913 specify the timeout in seconds. default 2 seconds.
916 CONFIG_VERSION_VARIABLE
917 If this variable is defined, an environment variable
918 named "ver" is created by U-Boot showing the U-Boot
919 version as printed by the "version" command.
920 Any change to this variable will be reverted at the
925 When CONFIG_CMD_DATE is selected, the type of the RTC
926 has to be selected, too. Define exactly one of the
929 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
930 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
931 CONFIG_RTC_MC146818 - use MC146818 RTC
932 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
933 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
934 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
935 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
936 CONFIG_RTC_DS164x - use Dallas DS164x RTC
937 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
938 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
939 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
940 CONFIG_SYS_RV3029_TCR - enable trickle charger on
943 Note that if the RTC uses I2C, then the I2C interface
944 must also be configured. See I2C Support, below.
947 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
949 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
950 chip-ngpio pairs that tell the PCA953X driver the number of
951 pins supported by a particular chip.
953 Note that if the GPIO device uses I2C, then the I2C interface
954 must also be configured. See I2C Support, below.
957 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
958 accesses and can checksum them or write a list of them out
959 to memory. See the 'iotrace' command for details. This is
960 useful for testing device drivers since it can confirm that
961 the driver behaves the same way before and after a code
962 change. Currently this is supported on sandbox and arm. To
963 add support for your architecture, add '#include <iotrace.h>'
964 to the bottom of arch/<arch>/include/asm/io.h and test.
966 Example output from the 'iotrace stats' command is below.
967 Note that if the trace buffer is exhausted, the checksum will
968 still continue to operate.
971 Start: 10000000 (buffer start address)
972 Size: 00010000 (buffer size)
973 Offset: 00000120 (current buffer offset)
974 Output: 10000120 (start + offset)
975 Count: 00000018 (number of trace records)
976 CRC32: 9526fb66 (CRC32 of all trace records)
980 When CONFIG_TIMESTAMP is selected, the timestamp
981 (date and time) of an image is printed by image
982 commands like bootm or iminfo. This option is
983 automatically enabled when you select CONFIG_CMD_DATE .
985 - Partition Labels (disklabels) Supported:
986 Zero or more of the following:
987 CONFIG_MAC_PARTITION Apple's MacOS partition table.
988 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
989 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
990 bootloader. Note 2TB partition limit; see
992 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
994 If IDE or SCSI support is enabled (CONFIG_IDE or
995 CONFIG_SCSI) you must configure support for at
996 least one non-MTD partition type as well.
999 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1000 board configurations files but used nowhere!
1002 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1003 be performed by calling the function
1004 ide_set_reset(int reset)
1005 which has to be defined in a board specific file
1010 Set this to enable ATAPI support.
1015 Set this to enable support for disks larger than 137GB
1016 Also look at CONFIG_SYS_64BIT_LBA.
1017 Whithout these , LBA48 support uses 32bit variables and will 'only'
1018 support disks up to 2.1TB.
1020 CONFIG_SYS_64BIT_LBA:
1021 When enabled, makes the IDE subsystem use 64bit sector addresses.
1025 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1026 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1027 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1028 maximum numbers of LUNs, SCSI ID's and target
1031 The environment variable 'scsidevs' is set to the number of
1032 SCSI devices found during the last scan.
1034 - NETWORK Support (PCI):
1036 Support for Intel 8254x/8257x gigabit chips.
1039 Utility code for direct access to the SPI bus on Intel 8257x.
1040 This does not do anything useful unless you set at least one
1041 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1043 CONFIG_E1000_SPI_GENERIC
1044 Allow generic access to the SPI bus on the Intel 8257x, for
1045 example with the "sspi" command.
1048 Management command for E1000 devices. When used on devices
1049 with SPI support you can reprogram the EEPROM from U-Boot.
1052 Support for Intel 82557/82559/82559ER chips.
1053 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1054 write routine for first time initialisation.
1057 Support for Digital 2114x chips.
1058 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1059 modem chip initialisation (KS8761/QS6611).
1062 Support for National dp83815 chips.
1065 Support for National dp8382[01] gigabit chips.
1067 - NETWORK Support (other):
1069 CONFIG_DRIVER_AT91EMAC
1070 Support for AT91RM9200 EMAC.
1073 Define this to use reduced MII inteface
1075 CONFIG_DRIVER_AT91EMAC_QUIET
1076 If this defined, the driver is quiet.
1077 The driver doen't show link status messages.
1079 CONFIG_CALXEDA_XGMAC
1080 Support for the Calxeda XGMAC device
1083 Support for SMSC's LAN91C96 chips.
1085 CONFIG_LAN91C96_USE_32_BIT
1086 Define this to enable 32 bit addressing
1089 Support for SMSC's LAN91C111 chip
1091 CONFIG_SMC91111_BASE
1092 Define this to hold the physical address
1093 of the device (I/O space)
1095 CONFIG_SMC_USE_32_BIT
1096 Define this if data bus is 32 bits
1098 CONFIG_SMC_USE_IOFUNCS
1099 Define this to use i/o functions instead of macros
1100 (some hardware wont work with macros)
1102 CONFIG_DRIVER_TI_EMAC
1103 Support for davinci emac
1105 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1106 Define this if you have more then 3 PHYs.
1109 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1111 CONFIG_FTGMAC100_EGIGA
1112 Define this to use GE link update with gigabit PHY.
1113 Define this if FTGMAC100 is connected to gigabit PHY.
1114 If your system has 10/100 PHY only, it might not occur
1115 wrong behavior. Because PHY usually return timeout or
1116 useless data when polling gigabit status and gigabit
1117 control registers. This behavior won't affect the
1118 correctnessof 10/100 link speed update.
1121 Support for SMSC's LAN911x and LAN921x chips
1124 Define this to hold the physical address
1125 of the device (I/O space)
1127 CONFIG_SMC911X_32_BIT
1128 Define this if data bus is 32 bits
1130 CONFIG_SMC911X_16_BIT
1131 Define this if data bus is 16 bits. If your processor
1132 automatically converts one 32 bit word to two 16 bit
1133 words you may also try CONFIG_SMC911X_32_BIT.
1136 Support for Renesas on-chip Ethernet controller
1138 CONFIG_SH_ETHER_USE_PORT
1139 Define the number of ports to be used
1141 CONFIG_SH_ETHER_PHY_ADDR
1142 Define the ETH PHY's address
1144 CONFIG_SH_ETHER_CACHE_WRITEBACK
1145 If this option is set, the driver enables cache flush.
1149 Support for PWM module on the imx6.
1153 Support TPM devices.
1155 CONFIG_TPM_TIS_INFINEON
1156 Support for Infineon i2c bus TPM devices. Only one device
1157 per system is supported at this time.
1159 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1160 Define the burst count bytes upper limit
1163 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1165 CONFIG_TPM_ST33ZP24_I2C
1166 Support for STMicroelectronics ST33ZP24 I2C devices.
1167 Requires TPM_ST33ZP24 and I2C.
1169 CONFIG_TPM_ST33ZP24_SPI
1170 Support for STMicroelectronics ST33ZP24 SPI devices.
1171 Requires TPM_ST33ZP24 and SPI.
1173 CONFIG_TPM_ATMEL_TWI
1174 Support for Atmel TWI TPM device. Requires I2C support.
1177 Support for generic parallel port TPM devices. Only one device
1178 per system is supported at this time.
1180 CONFIG_TPM_TIS_BASE_ADDRESS
1181 Base address where the generic TPM device is mapped
1182 to. Contemporary x86 systems usually map it at
1186 Add tpm monitor functions.
1187 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1188 provides monitor access to authorized functions.
1191 Define this to enable the TPM support library which provides
1192 functional interfaces to some TPM commands.
1193 Requires support for a TPM device.
1195 CONFIG_TPM_AUTH_SESSIONS
1196 Define this to enable authorized functions in the TPM library.
1197 Requires CONFIG_TPM and CONFIG_SHA1.
1200 At the moment only the UHCI host controller is
1201 supported (PIP405, MIP405); define
1202 CONFIG_USB_UHCI to enable it.
1203 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1204 and define CONFIG_USB_STORAGE to enable the USB
1207 Supported are USB Keyboards and USB Floppy drives
1210 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1211 txfilltuning field in the EHCI controller on reset.
1213 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1214 HW module registers.
1217 Define the below if you wish to use the USB console.
1218 Once firmware is rebuilt from a serial console issue the
1219 command "setenv stdin usbtty; setenv stdout usbtty" and
1220 attach your USB cable. The Unix command "dmesg" should print
1221 it has found a new device. The environment variable usbtty
1222 can be set to gserial or cdc_acm to enable your device to
1223 appear to a USB host as a Linux gserial device or a
1224 Common Device Class Abstract Control Model serial device.
1225 If you select usbtty = gserial you should be able to enumerate
1227 # modprobe usbserial vendor=0xVendorID product=0xProductID
1228 else if using cdc_acm, simply setting the environment
1229 variable usbtty to be cdc_acm should suffice. The following
1230 might be defined in YourBoardName.h
1233 Define this to build a UDC device
1236 Define this to have a tty type of device available to
1237 talk to the UDC device
1240 Define this to enable the high speed support for usb
1241 device and usbtty. If this feature is enabled, a routine
1242 int is_usbd_high_speed(void)
1243 also needs to be defined by the driver to dynamically poll
1244 whether the enumeration has succeded at high speed or full
1247 CONFIG_SYS_CONSOLE_IS_IN_ENV
1248 Define this if you want stdin, stdout &/or stderr to
1251 If you have a USB-IF assigned VendorID then you may wish to
1252 define your own vendor specific values either in BoardName.h
1253 or directly in usbd_vendor_info.h. If you don't define
1254 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1255 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1256 should pretend to be a Linux device to it's target host.
1258 CONFIG_USBD_MANUFACTURER
1259 Define this string as the name of your company for
1260 - CONFIG_USBD_MANUFACTURER "my company"
1262 CONFIG_USBD_PRODUCT_NAME
1263 Define this string as the name of your product
1264 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1266 CONFIG_USBD_VENDORID
1267 Define this as your assigned Vendor ID from the USB
1268 Implementors Forum. This *must* be a genuine Vendor ID
1269 to avoid polluting the USB namespace.
1270 - CONFIG_USBD_VENDORID 0xFFFF
1272 CONFIG_USBD_PRODUCTID
1273 Define this as the unique Product ID
1275 - CONFIG_USBD_PRODUCTID 0xFFFF
1277 - ULPI Layer Support:
1278 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1279 the generic ULPI layer. The generic layer accesses the ULPI PHY
1280 via the platform viewport, so you need both the genric layer and
1281 the viewport enabled. Currently only Chipidea/ARC based
1282 viewport is supported.
1283 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1284 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1285 If your ULPI phy needs a different reference clock than the
1286 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1287 the appropriate value in Hz.
1290 The MMC controller on the Intel PXA is supported. To
1291 enable this define CONFIG_MMC. The MMC can be
1292 accessed from the boot prompt by mapping the device
1293 to physical memory similar to flash. Command line is
1294 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1295 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1298 Support for Renesas on-chip MMCIF controller
1300 CONFIG_SH_MMCIF_ADDR
1301 Define the base address of MMCIF registers
1304 Define the clock frequency for MMCIF
1306 CONFIG_SUPPORT_EMMC_BOOT
1307 Enable some additional features of the eMMC boot partitions.
1309 CONFIG_SUPPORT_EMMC_RPMB
1310 Enable the commands for reading, writing and programming the
1311 key for the Replay Protection Memory Block partition in eMMC.
1313 - USB Device Firmware Update (DFU) class support:
1314 CONFIG_USB_FUNCTION_DFU
1315 This enables the USB portion of the DFU USB class
1318 This enables the command "dfu" which is used to have
1319 U-Boot create a DFU class device via USB. This command
1320 requires that the "dfu_alt_info" environment variable be
1321 set and define the alt settings to expose to the host.
1324 This enables support for exposing (e)MMC devices via DFU.
1327 This enables support for exposing NAND devices via DFU.
1330 This enables support for exposing RAM via DFU.
1331 Note: DFU spec refer to non-volatile memory usage, but
1332 allow usages beyond the scope of spec - here RAM usage,
1333 one that would help mostly the developer.
1335 CONFIG_SYS_DFU_DATA_BUF_SIZE
1336 Dfu transfer uses a buffer before writing data to the
1337 raw storage device. Make the size (in bytes) of this buffer
1338 configurable. The size of this buffer is also configurable
1339 through the "dfu_bufsiz" environment variable.
1341 CONFIG_SYS_DFU_MAX_FILE_SIZE
1342 When updating files rather than the raw storage device,
1343 we use a static buffer to copy the file into and then write
1344 the buffer once we've been given the whole file. Define
1345 this to the maximum filesize (in bytes) for the buffer.
1346 Default is 4 MiB if undefined.
1348 DFU_DEFAULT_POLL_TIMEOUT
1349 Poll timeout [ms], is the timeout a device can send to the
1350 host. The host must wait for this timeout before sending
1351 a subsequent DFU_GET_STATUS request to the device.
1353 DFU_MANIFEST_POLL_TIMEOUT
1354 Poll timeout [ms], which the device sends to the host when
1355 entering dfuMANIFEST state. Host waits this timeout, before
1356 sending again an USB request to the device.
1358 - USB Device Android Fastboot support:
1359 CONFIG_USB_FUNCTION_FASTBOOT
1360 This enables the USB part of the fastboot gadget
1363 This enables the command "fastboot" which enables the Android
1364 fastboot mode for the platform's USB device. Fastboot is a USB
1365 protocol for downloading images, flashing and device control
1366 used on Android devices.
1367 See doc/README.android-fastboot for more information.
1369 CONFIG_ANDROID_BOOT_IMAGE
1370 This enables support for booting images which use the Android
1371 image format header.
1373 CONFIG_FASTBOOT_BUF_ADDR
1374 The fastboot protocol requires a large memory buffer for
1375 downloads. Define this to the starting RAM address to use for
1378 CONFIG_FASTBOOT_BUF_SIZE
1379 The fastboot protocol requires a large memory buffer for
1380 downloads. This buffer should be as large as possible for a
1381 platform. Define this to the size available RAM for fastboot.
1383 CONFIG_FASTBOOT_FLASH
1384 The fastboot protocol includes a "flash" command for writing
1385 the downloaded image to a non-volatile storage device. Define
1386 this to enable the "fastboot flash" command.
1388 CONFIG_FASTBOOT_FLASH_MMC_DEV
1389 The fastboot "flash" command requires additional information
1390 regarding the non-volatile storage device. Define this to
1391 the eMMC device that fastboot should use to store the image.
1393 CONFIG_FASTBOOT_GPT_NAME
1394 The fastboot "flash" command supports writing the downloaded
1395 image to the Protective MBR and the Primary GUID Partition
1396 Table. (Additionally, this downloaded image is post-processed
1397 to generate and write the Backup GUID Partition Table.)
1398 This occurs when the specified "partition name" on the
1399 "fastboot flash" command line matches this value.
1400 The default is "gpt" if undefined.
1402 CONFIG_FASTBOOT_MBR_NAME
1403 The fastboot "flash" command supports writing the downloaded
1405 This occurs when the "partition name" specified on the
1406 "fastboot flash" command line matches this value.
1407 If not defined the default value "mbr" is used.
1409 - Journaling Flash filesystem support:
1411 Define these for a default partition on a NAND device
1413 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1414 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1415 Define these for a default partition on a NOR device
1418 See Kconfig help for available keyboard drivers.
1422 Define this to enable a custom keyboard support.
1423 This simply calls drv_keyboard_init() which must be
1424 defined in your board-specific files. This option is deprecated
1425 and is only used by novena. For new boards, use driver model
1430 Enable the Freescale DIU video driver. Reference boards for
1431 SOCs that have a DIU should define this macro to enable DIU
1432 support, and should also define these other macros:
1437 CONFIG_VIDEO_SW_CURSOR
1438 CONFIG_VGA_AS_SINGLE_DEVICE
1440 CONFIG_VIDEO_BMP_LOGO
1442 The DIU driver will look for the 'video-mode' environment
1443 variable, and if defined, enable the DIU as a console during
1444 boot. See the documentation file doc/README.video for a
1445 description of this variable.
1447 - LCD Support: CONFIG_LCD
1449 Define this to enable LCD support (for output to LCD
1450 display); also select one of the supported displays
1451 by defining one of these:
1455 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1457 CONFIG_NEC_NL6448AC33:
1459 NEC NL6448AC33-18. Active, color, single scan.
1461 CONFIG_NEC_NL6448BC20
1463 NEC NL6448BC20-08. 6.5", 640x480.
1464 Active, color, single scan.
1466 CONFIG_NEC_NL6448BC33_54
1468 NEC NL6448BC33-54. 10.4", 640x480.
1469 Active, color, single scan.
1473 Sharp 320x240. Active, color, single scan.
1474 It isn't 16x9, and I am not sure what it is.
1476 CONFIG_SHARP_LQ64D341
1478 Sharp LQ64D341 display, 640x480.
1479 Active, color, single scan.
1483 HLD1045 display, 640x480.
1484 Active, color, single scan.
1488 Optrex CBL50840-2 NF-FW 99 22 M5
1490 Hitachi LMG6912RPFC-00T
1494 320x240. Black & white.
1496 CONFIG_LCD_ALIGNMENT
1498 Normally the LCD is page-aligned (typically 4KB). If this is
1499 defined then the LCD will be aligned to this value instead.
1500 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1501 here, since it is cheaper to change data cache settings on
1502 a per-section basis.
1507 Sometimes, for example if the display is mounted in portrait
1508 mode or even if it's mounted landscape but rotated by 180degree,
1509 we need to rotate our content of the display relative to the
1510 framebuffer, so that user can read the messages which are
1512 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1513 initialized with a given rotation from "vl_rot" out of
1514 "vidinfo_t" which is provided by the board specific code.
1515 The value for vl_rot is coded as following (matching to
1516 fbcon=rotate:<n> linux-kernel commandline):
1517 0 = no rotation respectively 0 degree
1518 1 = 90 degree rotation
1519 2 = 180 degree rotation
1520 3 = 270 degree rotation
1522 If CONFIG_LCD_ROTATION is not defined, the console will be
1523 initialized with 0degree rotation.
1527 Support drawing of RLE8-compressed bitmaps on the LCD.
1531 Enables an 'i2c edid' command which can read EDID
1532 information over I2C from an attached LCD display.
1534 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1536 If this option is set, the environment is checked for
1537 a variable "splashimage". If found, the usual display
1538 of logo, copyright and system information on the LCD
1539 is suppressed and the BMP image at the address
1540 specified in "splashimage" is loaded instead. The
1541 console is redirected to the "nulldev", too. This
1542 allows for a "silent" boot where a splash screen is
1543 loaded very quickly after power-on.
1545 CONFIG_SPLASHIMAGE_GUARD
1547 If this option is set, then U-Boot will prevent the environment
1548 variable "splashimage" from being set to a problematic address
1549 (see doc/README.displaying-bmps).
1550 This option is useful for targets where, due to alignment
1551 restrictions, an improperly aligned BMP image will cause a data
1552 abort. If you think you will not have problems with unaligned
1553 accesses (for example because your toolchain prevents them)
1554 there is no need to set this option.
1556 CONFIG_SPLASH_SCREEN_ALIGN
1558 If this option is set the splash image can be freely positioned
1559 on the screen. Environment variable "splashpos" specifies the
1560 position as "x,y". If a positive number is given it is used as
1561 number of pixel from left/top. If a negative number is given it
1562 is used as number of pixel from right/bottom. You can also
1563 specify 'm' for centering the image.
1566 setenv splashpos m,m
1567 => image at center of screen
1569 setenv splashpos 30,20
1570 => image at x = 30 and y = 20
1572 setenv splashpos -10,m
1573 => vertically centered image
1574 at x = dspWidth - bmpWidth - 9
1576 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1578 If this option is set, additionally to standard BMP
1579 images, gzipped BMP images can be displayed via the
1580 splashscreen support or the bmp command.
1582 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1584 If this option is set, 8-bit RLE compressed BMP images
1585 can be displayed via the splashscreen support or the
1588 - Compression support:
1591 Enabled by default to support gzip compressed images.
1595 If this option is set, support for bzip2 compressed
1596 images is included. If not, only uncompressed and gzip
1597 compressed images are supported.
1599 NOTE: the bzip2 algorithm requires a lot of RAM, so
1600 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1606 The address of PHY on MII bus.
1608 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1610 The clock frequency of the MII bus
1612 CONFIG_PHY_RESET_DELAY
1614 Some PHY like Intel LXT971A need extra delay after
1615 reset before any MII register access is possible.
1616 For such PHY, set this option to the usec delay
1617 required. (minimum 300usec for LXT971A)
1619 CONFIG_PHY_CMD_DELAY (ppc4xx)
1621 Some PHY like Intel LXT971A need extra delay after
1622 command issued before MII status register can be read
1627 Define a default value for the IP address to use for
1628 the default Ethernet interface, in case this is not
1629 determined through e.g. bootp.
1630 (Environment variable "ipaddr")
1632 - Server IP address:
1635 Defines a default value for the IP address of a TFTP
1636 server to contact when using the "tftboot" command.
1637 (Environment variable "serverip")
1639 CONFIG_KEEP_SERVERADDR
1641 Keeps the server's MAC address, in the env 'serveraddr'
1642 for passing to bootargs (like Linux's netconsole option)
1644 - Gateway IP address:
1647 Defines a default value for the IP address of the
1648 default router where packets to other networks are
1650 (Environment variable "gatewayip")
1655 Defines a default value for the subnet mask (or
1656 routing prefix) which is used to determine if an IP
1657 address belongs to the local subnet or needs to be
1658 forwarded through a router.
1659 (Environment variable "netmask")
1661 - Multicast TFTP Mode:
1664 Defines whether you want to support multicast TFTP as per
1665 rfc-2090; for example to work with atftp. Lets lots of targets
1666 tftp down the same boot image concurrently. Note: the Ethernet
1667 driver in use must provide a function: mcast() to join/leave a
1670 - BOOTP Recovery Mode:
1671 CONFIG_BOOTP_RANDOM_DELAY
1673 If you have many targets in a network that try to
1674 boot using BOOTP, you may want to avoid that all
1675 systems send out BOOTP requests at precisely the same
1676 moment (which would happen for instance at recovery
1677 from a power failure, when all systems will try to
1678 boot, thus flooding the BOOTP server. Defining
1679 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1680 inserted before sending out BOOTP requests. The
1681 following delays are inserted then:
1683 1st BOOTP request: delay 0 ... 1 sec
1684 2nd BOOTP request: delay 0 ... 2 sec
1685 3rd BOOTP request: delay 0 ... 4 sec
1687 BOOTP requests: delay 0 ... 8 sec
1689 CONFIG_BOOTP_ID_CACHE_SIZE
1691 BOOTP packets are uniquely identified using a 32-bit ID. The
1692 server will copy the ID from client requests to responses and
1693 U-Boot will use this to determine if it is the destination of
1694 an incoming response. Some servers will check that addresses
1695 aren't in use before handing them out (usually using an ARP
1696 ping) and therefore take up to a few hundred milliseconds to
1697 respond. Network congestion may also influence the time it
1698 takes for a response to make it back to the client. If that
1699 time is too long, U-Boot will retransmit requests. In order
1700 to allow earlier responses to still be accepted after these
1701 retransmissions, U-Boot's BOOTP client keeps a small cache of
1702 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1703 cache. The default is to keep IDs for up to four outstanding
1704 requests. Increasing this will allow U-Boot to accept offers
1705 from a BOOTP client in networks with unusually high latency.
1707 - DHCP Advanced Options:
1708 You can fine tune the DHCP functionality by defining
1709 CONFIG_BOOTP_* symbols:
1711 CONFIG_BOOTP_SUBNETMASK
1712 CONFIG_BOOTP_GATEWAY
1713 CONFIG_BOOTP_HOSTNAME
1714 CONFIG_BOOTP_NISDOMAIN
1715 CONFIG_BOOTP_BOOTPATH
1716 CONFIG_BOOTP_BOOTFILESIZE
1719 CONFIG_BOOTP_SEND_HOSTNAME
1720 CONFIG_BOOTP_NTPSERVER
1721 CONFIG_BOOTP_TIMEOFFSET
1722 CONFIG_BOOTP_VENDOREX
1723 CONFIG_BOOTP_MAY_FAIL
1725 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1726 environment variable, not the BOOTP server.
1728 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1729 after the configured retry count, the call will fail
1730 instead of starting over. This can be used to fail over
1731 to Link-local IP address configuration if the DHCP server
1734 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1735 serverip from a DHCP server, it is possible that more
1736 than one DNS serverip is offered to the client.
1737 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1738 serverip will be stored in the additional environment
1739 variable "dnsip2". The first DNS serverip is always
1740 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1743 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1744 to do a dynamic update of a DNS server. To do this, they
1745 need the hostname of the DHCP requester.
1746 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1747 of the "hostname" environment variable is passed as
1748 option 12 to the DHCP server.
1750 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1752 A 32bit value in microseconds for a delay between
1753 receiving a "DHCP Offer" and sending the "DHCP Request".
1754 This fixes a problem with certain DHCP servers that don't
1755 respond 100% of the time to a "DHCP request". E.g. On an
1756 AT91RM9200 processor running at 180MHz, this delay needed
1757 to be *at least* 15,000 usec before a Windows Server 2003
1758 DHCP server would reply 100% of the time. I recommend at
1759 least 50,000 usec to be safe. The alternative is to hope
1760 that one of the retries will be successful but note that
1761 the DHCP timeout and retry process takes a longer than
1764 - Link-local IP address negotiation:
1765 Negotiate with other link-local clients on the local network
1766 for an address that doesn't require explicit configuration.
1767 This is especially useful if a DHCP server cannot be guaranteed
1768 to exist in all environments that the device must operate.
1770 See doc/README.link-local for more information.
1773 CONFIG_CDP_DEVICE_ID
1775 The device id used in CDP trigger frames.
1777 CONFIG_CDP_DEVICE_ID_PREFIX
1779 A two character string which is prefixed to the MAC address
1784 A printf format string which contains the ascii name of
1785 the port. Normally is set to "eth%d" which sets
1786 eth0 for the first Ethernet, eth1 for the second etc.
1788 CONFIG_CDP_CAPABILITIES
1790 A 32bit integer which indicates the device capabilities;
1791 0x00000010 for a normal host which does not forwards.
1795 An ascii string containing the version of the software.
1799 An ascii string containing the name of the platform.
1803 A 32bit integer sent on the trigger.
1805 CONFIG_CDP_POWER_CONSUMPTION
1807 A 16bit integer containing the power consumption of the
1808 device in .1 of milliwatts.
1810 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1812 A byte containing the id of the VLAN.
1814 - Status LED: CONFIG_LED_STATUS
1816 Several configurations allow to display the current
1817 status using a LED. For instance, the LED will blink
1818 fast while running U-Boot code, stop blinking as
1819 soon as a reply to a BOOTP request was received, and
1820 start blinking slow once the Linux kernel is running
1821 (supported by a status LED driver in the Linux
1822 kernel). Defining CONFIG_LED_STATUS enables this
1827 CONFIG_LED_STATUS_GPIO
1828 The status LED can be connected to a GPIO pin.
1829 In such cases, the gpio_led driver can be used as a
1830 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1831 to include the gpio_led driver in the U-Boot binary.
1833 CONFIG_GPIO_LED_INVERTED_TABLE
1834 Some GPIO connected LEDs may have inverted polarity in which
1835 case the GPIO high value corresponds to LED off state and
1836 GPIO low value corresponds to LED on state.
1837 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1838 with a list of GPIO LEDs that have inverted polarity.
1840 - I2C Support: CONFIG_SYS_I2C
1842 This enable the NEW i2c subsystem, and will allow you to use
1843 i2c commands at the u-boot command line (as long as you set
1844 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1845 based realtime clock chips or other i2c devices. See
1846 common/cmd_i2c.c for a description of the command line
1849 ported i2c driver to the new framework:
1850 - drivers/i2c/soft_i2c.c:
1851 - activate first bus with CONFIG_SYS_I2C_SOFT define
1852 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1853 for defining speed and slave address
1854 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1855 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1856 for defining speed and slave address
1857 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1858 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1859 for defining speed and slave address
1860 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1861 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1862 for defining speed and slave address
1864 - drivers/i2c/fsl_i2c.c:
1865 - activate i2c driver with CONFIG_SYS_I2C_FSL
1866 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1867 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1868 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1870 - If your board supports a second fsl i2c bus, define
1871 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1872 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1873 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1876 - drivers/i2c/tegra_i2c.c:
1877 - activate this driver with CONFIG_SYS_I2C_TEGRA
1878 - This driver adds 4 i2c buses with a fix speed from
1879 100000 and the slave addr 0!
1881 - drivers/i2c/ppc4xx_i2c.c
1882 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1883 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1884 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1886 - drivers/i2c/i2c_mxc.c
1887 - activate this driver with CONFIG_SYS_I2C_MXC
1888 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1889 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1890 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1891 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1892 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1893 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1894 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1895 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1896 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1897 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1898 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1899 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1900 If those defines are not set, default value is 100000
1901 for speed, and 0 for slave.
1903 - drivers/i2c/rcar_i2c.c:
1904 - activate this driver with CONFIG_SYS_I2C_RCAR
1905 - This driver adds 4 i2c buses
1907 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1908 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1909 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1910 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1911 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1912 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1913 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1914 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1915 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1917 - drivers/i2c/sh_i2c.c:
1918 - activate this driver with CONFIG_SYS_I2C_SH
1919 - This driver adds from 2 to 5 i2c buses
1921 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1922 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1923 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1924 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1925 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1926 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1927 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1928 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1929 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1930 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1931 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1933 - drivers/i2c/omap24xx_i2c.c
1934 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1935 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1936 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1937 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1938 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1939 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1940 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1941 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1942 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1943 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1944 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1946 - drivers/i2c/zynq_i2c.c
1947 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1948 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1949 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1951 - drivers/i2c/s3c24x0_i2c.c:
1952 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1953 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1954 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1955 with a fix speed from 100000 and the slave addr 0!
1957 - drivers/i2c/ihs_i2c.c
1958 - activate this driver with CONFIG_SYS_I2C_IHS
1959 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1960 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1961 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1962 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1963 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1964 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1965 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1966 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1967 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1968 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1969 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1970 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
1971 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1972 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1973 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1974 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1975 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1976 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1977 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1978 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1979 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
1983 CONFIG_SYS_NUM_I2C_BUSES
1984 Hold the number of i2c buses you want to use.
1986 CONFIG_SYS_I2C_DIRECT_BUS
1987 define this, if you don't use i2c muxes on your hardware.
1988 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1991 CONFIG_SYS_I2C_MAX_HOPS
1992 define how many muxes are maximal consecutively connected
1993 on one i2c bus. If you not use i2c muxes, omit this
1996 CONFIG_SYS_I2C_BUSES
1997 hold a list of buses you want to use, only used if
1998 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1999 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2000 CONFIG_SYS_NUM_I2C_BUSES = 9:
2002 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2003 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2004 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2005 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2006 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2007 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2008 {1, {I2C_NULL_HOP}}, \
2009 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2010 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2014 bus 0 on adapter 0 without a mux
2015 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2016 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2017 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2018 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2019 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2020 bus 6 on adapter 1 without a mux
2021 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2022 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2024 If you do not have i2c muxes on your board, omit this define.
2026 - Legacy I2C Support:
2027 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2028 then the following macros need to be defined (examples are
2029 from include/configs/lwmon.h):
2033 (Optional). Any commands necessary to enable the I2C
2034 controller or configure ports.
2036 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2040 The code necessary to make the I2C data line active
2041 (driven). If the data line is open collector, this
2044 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2048 The code necessary to make the I2C data line tri-stated
2049 (inactive). If the data line is open collector, this
2052 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2056 Code that returns true if the I2C data line is high,
2059 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2063 If <bit> is true, sets the I2C data line high. If it
2064 is false, it clears it (low).
2066 eg: #define I2C_SDA(bit) \
2067 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2068 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2072 If <bit> is true, sets the I2C clock line high. If it
2073 is false, it clears it (low).
2075 eg: #define I2C_SCL(bit) \
2076 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2077 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2081 This delay is invoked four times per clock cycle so this
2082 controls the rate of data transfer. The data rate thus
2083 is 1 / (I2C_DELAY * 4). Often defined to be something
2086 #define I2C_DELAY udelay(2)
2088 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2090 If your arch supports the generic GPIO framework (asm/gpio.h),
2091 then you may alternatively define the two GPIOs that are to be
2092 used as SCL / SDA. Any of the previous I2C_xxx macros will
2093 have GPIO-based defaults assigned to them as appropriate.
2095 You should define these to the GPIO value as given directly to
2096 the generic GPIO functions.
2098 CONFIG_SYS_I2C_INIT_BOARD
2100 When a board is reset during an i2c bus transfer
2101 chips might think that the current transfer is still
2102 in progress. On some boards it is possible to access
2103 the i2c SCLK line directly, either by using the
2104 processor pin as a GPIO or by having a second pin
2105 connected to the bus. If this option is defined a
2106 custom i2c_init_board() routine in boards/xxx/board.c
2107 is run early in the boot sequence.
2109 CONFIG_I2C_MULTI_BUS
2111 This option allows the use of multiple I2C buses, each of which
2112 must have a controller. At any point in time, only one bus is
2113 active. To switch to a different bus, use the 'i2c dev' command.
2114 Note that bus numbering is zero-based.
2116 CONFIG_SYS_I2C_NOPROBES
2118 This option specifies a list of I2C devices that will be skipped
2119 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2120 is set, specify a list of bus-device pairs. Otherwise, specify
2121 a 1D array of device addresses
2124 #undef CONFIG_I2C_MULTI_BUS
2125 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2127 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2129 #define CONFIG_I2C_MULTI_BUS
2130 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2132 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2134 CONFIG_SYS_SPD_BUS_NUM
2136 If defined, then this indicates the I2C bus number for DDR SPD.
2137 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2139 CONFIG_SYS_RTC_BUS_NUM
2141 If defined, then this indicates the I2C bus number for the RTC.
2142 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2144 CONFIG_SOFT_I2C_READ_REPEATED_START
2146 defining this will force the i2c_read() function in
2147 the soft_i2c driver to perform an I2C repeated start
2148 between writing the address pointer and reading the
2149 data. If this define is omitted the default behaviour
2150 of doing a stop-start sequence will be used. Most I2C
2151 devices can use either method, but some require one or
2154 - SPI Support: CONFIG_SPI
2156 Enables SPI driver (so far only tested with
2157 SPI EEPROM, also an instance works with Crystal A/D and
2158 D/As on the SACSng board)
2162 Enables the driver for SPI controller on SuperH. Currently
2163 only SH7757 is supported.
2167 Enables a software (bit-bang) SPI driver rather than
2168 using hardware support. This is a general purpose
2169 driver that only requires three general I/O port pins
2170 (two outputs, one input) to function. If this is
2171 defined, the board configuration must define several
2172 SPI configuration items (port pins to use, etc). For
2173 an example, see include/configs/sacsng.h.
2177 Enables a hardware SPI driver for general-purpose reads
2178 and writes. As with CONFIG_SOFT_SPI, the board configuration
2179 must define a list of chip-select function pointers.
2180 Currently supported on some MPC8xxx processors. For an
2181 example, see include/configs/mpc8349emds.h.
2185 Enables the driver for the SPI controllers on i.MX and MXC
2186 SoCs. Currently i.MX31/35/51 are supported.
2188 CONFIG_SYS_SPI_MXC_WAIT
2189 Timeout for waiting until spi transfer completed.
2190 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2192 - FPGA Support: CONFIG_FPGA
2194 Enables FPGA subsystem.
2196 CONFIG_FPGA_<vendor>
2198 Enables support for specific chip vendors.
2201 CONFIG_FPGA_<family>
2203 Enables support for FPGA family.
2204 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2208 Specify the number of FPGA devices to support.
2210 CONFIG_SYS_FPGA_PROG_FEEDBACK
2212 Enable printing of hash marks during FPGA configuration.
2214 CONFIG_SYS_FPGA_CHECK_BUSY
2216 Enable checks on FPGA configuration interface busy
2217 status by the configuration function. This option
2218 will require a board or device specific function to
2223 If defined, a function that provides delays in the FPGA
2224 configuration driver.
2226 CONFIG_SYS_FPGA_CHECK_CTRLC
2227 Allow Control-C to interrupt FPGA configuration
2229 CONFIG_SYS_FPGA_CHECK_ERROR
2231 Check for configuration errors during FPGA bitfile
2232 loading. For example, abort during Virtex II
2233 configuration if the INIT_B line goes low (which
2234 indicated a CRC error).
2236 CONFIG_SYS_FPGA_WAIT_INIT
2238 Maximum time to wait for the INIT_B line to de-assert
2239 after PROB_B has been de-asserted during a Virtex II
2240 FPGA configuration sequence. The default time is 500
2243 CONFIG_SYS_FPGA_WAIT_BUSY
2245 Maximum time to wait for BUSY to de-assert during
2246 Virtex II FPGA configuration. The default is 5 ms.
2248 CONFIG_SYS_FPGA_WAIT_CONFIG
2250 Time to wait after FPGA configuration. The default is
2253 - Configuration Management:
2256 Some SoCs need special image types (e.g. U-Boot binary
2257 with a special header) as build targets. By defining
2258 CONFIG_BUILD_TARGET in the SoC / board header, this
2259 special image will be automatically built upon calling
2264 If defined, this string will be added to the U-Boot
2265 version information (U_BOOT_VERSION)
2267 - Vendor Parameter Protection:
2269 U-Boot considers the values of the environment
2270 variables "serial#" (Board Serial Number) and
2271 "ethaddr" (Ethernet Address) to be parameters that
2272 are set once by the board vendor / manufacturer, and
2273 protects these variables from casual modification by
2274 the user. Once set, these variables are read-only,
2275 and write or delete attempts are rejected. You can
2276 change this behaviour:
2278 If CONFIG_ENV_OVERWRITE is #defined in your config
2279 file, the write protection for vendor parameters is
2280 completely disabled. Anybody can change or delete
2283 Alternatively, if you define _both_ an ethaddr in the
2284 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2285 Ethernet address is installed in the environment,
2286 which can be changed exactly ONCE by the user. [The
2287 serial# is unaffected by this, i. e. it remains
2290 The same can be accomplished in a more flexible way
2291 for any variable by configuring the type of access
2292 to allow for those variables in the ".flags" variable
2293 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2298 Define this variable to enable the reservation of
2299 "protected RAM", i. e. RAM which is not overwritten
2300 by U-Boot. Define CONFIG_PRAM to hold the number of
2301 kB you want to reserve for pRAM. You can overwrite
2302 this default value by defining an environment
2303 variable "pram" to the number of kB you want to
2304 reserve. Note that the board info structure will
2305 still show the full amount of RAM. If pRAM is
2306 reserved, a new environment variable "mem" will
2307 automatically be defined to hold the amount of
2308 remaining RAM in a form that can be passed as boot
2309 argument to Linux, for instance like that:
2311 setenv bootargs ... mem=\${mem}
2314 This way you can tell Linux not to use this memory,
2315 either, which results in a memory region that will
2316 not be affected by reboots.
2318 *WARNING* If your board configuration uses automatic
2319 detection of the RAM size, you must make sure that
2320 this memory test is non-destructive. So far, the
2321 following board configurations are known to be
2324 IVMS8, IVML24, SPD8xx,
2325 HERMES, IP860, RPXlite, LWMON,
2328 - Access to physical memory region (> 4GB)
2329 Some basic support is provided for operations on memory not
2330 normally accessible to U-Boot - e.g. some architectures
2331 support access to more than 4GB of memory on 32-bit
2332 machines using physical address extension or similar.
2333 Define CONFIG_PHYSMEM to access this basic support, which
2334 currently only supports clearing the memory.
2339 Define this variable to stop the system in case of a
2340 fatal error, so that you have to reset it manually.
2341 This is probably NOT a good idea for an embedded
2342 system where you want the system to reboot
2343 automatically as fast as possible, but it may be
2344 useful during development since you can try to debug
2345 the conditions that lead to the situation.
2347 CONFIG_NET_RETRY_COUNT
2349 This variable defines the number of retries for
2350 network operations like ARP, RARP, TFTP, or BOOTP
2351 before giving up the operation. If not defined, a
2352 default value of 5 is used.
2356 Timeout waiting for an ARP reply in milliseconds.
2360 Timeout in milliseconds used in NFS protocol.
2361 If you encounter "ERROR: Cannot umount" in nfs command,
2362 try longer timeout such as
2363 #define CONFIG_NFS_TIMEOUT 10000UL
2365 - Command Interpreter:
2366 CONFIG_AUTO_COMPLETE
2368 Enable auto completion of commands using TAB.
2370 CONFIG_SYS_PROMPT_HUSH_PS2
2372 This defines the secondary prompt string, which is
2373 printed when the command interpreter needs more input
2374 to complete a command. Usually "> ".
2378 In the current implementation, the local variables
2379 space and global environment variables space are
2380 separated. Local variables are those you define by
2381 simply typing `name=value'. To access a local
2382 variable later on, you have write `$name' or
2383 `${name}'; to execute the contents of a variable
2384 directly type `$name' at the command prompt.
2386 Global environment variables are those you use
2387 setenv/printenv to work with. To run a command stored
2388 in such a variable, you need to use the run command,
2389 and you must not use the '$' sign to access them.
2391 To store commands and special characters in a
2392 variable, please use double quotation marks
2393 surrounding the whole text of the variable, instead
2394 of the backslashes before semicolons and special
2397 - Command Line Editing and History:
2398 CONFIG_CMDLINE_EDITING
2400 Enable editing and History functions for interactive
2401 command line input operations
2403 - Command Line PS1/PS2 support:
2404 CONFIG_CMDLINE_PS_SUPPORT
2406 Enable support for changing the command prompt string
2407 at run-time. Only static string is supported so far.
2408 The string is obtained from environment variables PS1
2411 - Default Environment:
2412 CONFIG_EXTRA_ENV_SETTINGS
2414 Define this to contain any number of null terminated
2415 strings (variable = value pairs) that will be part of
2416 the default environment compiled into the boot image.
2418 For example, place something like this in your
2419 board's config file:
2421 #define CONFIG_EXTRA_ENV_SETTINGS \
2425 Warning: This method is based on knowledge about the
2426 internal format how the environment is stored by the
2427 U-Boot code. This is NOT an official, exported
2428 interface! Although it is unlikely that this format
2429 will change soon, there is no guarantee either.
2430 You better know what you are doing here.
2432 Note: overly (ab)use of the default environment is
2433 discouraged. Make sure to check other ways to preset
2434 the environment like the "source" command or the
2437 CONFIG_ENV_VARS_UBOOT_CONFIG
2439 Define this in order to add variables describing the
2440 U-Boot build configuration to the default environment.
2441 These will be named arch, cpu, board, vendor, and soc.
2443 Enabling this option will cause the following to be defined:
2451 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2453 Define this in order to add variables describing certain
2454 run-time determined information about the hardware to the
2455 environment. These will be named board_name, board_rev.
2457 CONFIG_DELAY_ENVIRONMENT
2459 Normally the environment is loaded when the board is
2460 initialised so that it is available to U-Boot. This inhibits
2461 that so that the environment is not available until
2462 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2463 this is instead controlled by the value of
2464 /config/load-environment.
2466 - DataFlash Support:
2467 CONFIG_HAS_DATAFLASH
2469 Defining this option enables DataFlash features and
2470 allows to read/write in Dataflash via the standard
2473 - Serial Flash support
2476 Defining this option enables SPI flash commands
2477 'sf probe/read/write/erase/update'.
2479 Usage requires an initial 'probe' to define the serial
2480 flash parameters, followed by read/write/erase/update
2483 The following defaults may be provided by the platform
2484 to handle the common case when only a single serial
2485 flash is present on the system.
2487 CONFIG_SF_DEFAULT_BUS Bus identifier
2488 CONFIG_SF_DEFAULT_CS Chip-select
2489 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2490 CONFIG_SF_DEFAULT_SPEED in Hz
2494 Adding this option adds support for Xilinx SystemACE
2495 chips attached via some sort of local bus. The address
2496 of the chip must also be defined in the
2497 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2499 #define CONFIG_SYSTEMACE
2500 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2502 When SystemACE support is added, the "ace" device type
2503 becomes available to the fat commands, i.e. fatls.
2505 - TFTP Fixed UDP Port:
2508 If this is defined, the environment variable tftpsrcp
2509 is used to supply the TFTP UDP source port value.
2510 If tftpsrcp isn't defined, the normal pseudo-random port
2511 number generator is used.
2513 Also, the environment variable tftpdstp is used to supply
2514 the TFTP UDP destination port value. If tftpdstp isn't
2515 defined, the normal port 69 is used.
2517 The purpose for tftpsrcp is to allow a TFTP server to
2518 blindly start the TFTP transfer using the pre-configured
2519 target IP address and UDP port. This has the effect of
2520 "punching through" the (Windows XP) firewall, allowing
2521 the remainder of the TFTP transfer to proceed normally.
2522 A better solution is to properly configure the firewall,
2523 but sometimes that is not allowed.
2525 - bootcount support:
2526 CONFIG_BOOTCOUNT_LIMIT
2528 This enables the bootcounter support, see:
2529 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2532 enable special bootcounter support on at91sam9xe based boards.
2534 enable special bootcounter support on da850 based boards.
2535 CONFIG_BOOTCOUNT_RAM
2536 enable support for the bootcounter in RAM
2537 CONFIG_BOOTCOUNT_I2C
2538 enable support for the bootcounter on an i2c (like RTC) device.
2539 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2540 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2542 CONFIG_BOOTCOUNT_ALEN = address len
2544 - Show boot progress:
2545 CONFIG_SHOW_BOOT_PROGRESS
2547 Defining this option allows to add some board-
2548 specific code (calling a user-provided function
2549 "show_boot_progress(int)") that enables you to show
2550 the system's boot progress on some display (for
2551 example, some LED's) on your board. At the moment,
2552 the following checkpoints are implemented:
2555 Legacy uImage format:
2558 1 common/cmd_bootm.c before attempting to boot an image
2559 -1 common/cmd_bootm.c Image header has bad magic number
2560 2 common/cmd_bootm.c Image header has correct magic number
2561 -2 common/cmd_bootm.c Image header has bad checksum
2562 3 common/cmd_bootm.c Image header has correct checksum
2563 -3 common/cmd_bootm.c Image data has bad checksum
2564 4 common/cmd_bootm.c Image data has correct checksum
2565 -4 common/cmd_bootm.c Image is for unsupported architecture
2566 5 common/cmd_bootm.c Architecture check OK
2567 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2568 6 common/cmd_bootm.c Image Type check OK
2569 -6 common/cmd_bootm.c gunzip uncompression error
2570 -7 common/cmd_bootm.c Unimplemented compression type
2571 7 common/cmd_bootm.c Uncompression OK
2572 8 common/cmd_bootm.c No uncompress/copy overwrite error
2573 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2575 9 common/image.c Start initial ramdisk verification
2576 -10 common/image.c Ramdisk header has bad magic number
2577 -11 common/image.c Ramdisk header has bad checksum
2578 10 common/image.c Ramdisk header is OK
2579 -12 common/image.c Ramdisk data has bad checksum
2580 11 common/image.c Ramdisk data has correct checksum
2581 12 common/image.c Ramdisk verification complete, start loading
2582 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2583 13 common/image.c Start multifile image verification
2584 14 common/image.c No initial ramdisk, no multifile, continue.
2586 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2588 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2589 -31 post/post.c POST test failed, detected by post_output_backlog()
2590 -32 post/post.c POST test failed, detected by post_run_single()
2592 34 common/cmd_doc.c before loading a Image from a DOC device
2593 -35 common/cmd_doc.c Bad usage of "doc" command
2594 35 common/cmd_doc.c correct usage of "doc" command
2595 -36 common/cmd_doc.c No boot device
2596 36 common/cmd_doc.c correct boot device
2597 -37 common/cmd_doc.c Unknown Chip ID on boot device
2598 37 common/cmd_doc.c correct chip ID found, device available
2599 -38 common/cmd_doc.c Read Error on boot device
2600 38 common/cmd_doc.c reading Image header from DOC device OK
2601 -39 common/cmd_doc.c Image header has bad magic number
2602 39 common/cmd_doc.c Image header has correct magic number
2603 -40 common/cmd_doc.c Error reading Image from DOC device
2604 40 common/cmd_doc.c Image header has correct magic number
2605 41 common/cmd_ide.c before loading a Image from a IDE device
2606 -42 common/cmd_ide.c Bad usage of "ide" command
2607 42 common/cmd_ide.c correct usage of "ide" command
2608 -43 common/cmd_ide.c No boot device
2609 43 common/cmd_ide.c boot device found
2610 -44 common/cmd_ide.c Device not available
2611 44 common/cmd_ide.c Device available
2612 -45 common/cmd_ide.c wrong partition selected
2613 45 common/cmd_ide.c partition selected
2614 -46 common/cmd_ide.c Unknown partition table
2615 46 common/cmd_ide.c valid partition table found
2616 -47 common/cmd_ide.c Invalid partition type
2617 47 common/cmd_ide.c correct partition type
2618 -48 common/cmd_ide.c Error reading Image Header on boot device
2619 48 common/cmd_ide.c reading Image Header from IDE device OK
2620 -49 common/cmd_ide.c Image header has bad magic number
2621 49 common/cmd_ide.c Image header has correct magic number
2622 -50 common/cmd_ide.c Image header has bad checksum
2623 50 common/cmd_ide.c Image header has correct checksum
2624 -51 common/cmd_ide.c Error reading Image from IDE device
2625 51 common/cmd_ide.c reading Image from IDE device OK
2626 52 common/cmd_nand.c before loading a Image from a NAND device
2627 -53 common/cmd_nand.c Bad usage of "nand" command
2628 53 common/cmd_nand.c correct usage of "nand" command
2629 -54 common/cmd_nand.c No boot device
2630 54 common/cmd_nand.c boot device found
2631 -55 common/cmd_nand.c Unknown Chip ID on boot device
2632 55 common/cmd_nand.c correct chip ID found, device available
2633 -56 common/cmd_nand.c Error reading Image Header on boot device
2634 56 common/cmd_nand.c reading Image Header from NAND device OK
2635 -57 common/cmd_nand.c Image header has bad magic number
2636 57 common/cmd_nand.c Image header has correct magic number
2637 -58 common/cmd_nand.c Error reading Image from NAND device
2638 58 common/cmd_nand.c reading Image from NAND device OK
2640 -60 common/env_common.c Environment has a bad CRC, using default
2642 64 net/eth.c starting with Ethernet configuration.
2643 -64 net/eth.c no Ethernet found.
2644 65 net/eth.c Ethernet found.
2646 -80 common/cmd_net.c usage wrong
2647 80 common/cmd_net.c before calling net_loop()
2648 -81 common/cmd_net.c some error in net_loop() occurred
2649 81 common/cmd_net.c net_loop() back without error
2650 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2651 82 common/cmd_net.c trying automatic boot
2652 83 common/cmd_net.c running "source" command
2653 -83 common/cmd_net.c some error in automatic boot or "source" command
2654 84 common/cmd_net.c end without errors
2659 100 common/cmd_bootm.c Kernel FIT Image has correct format
2660 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2661 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2662 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2663 102 common/cmd_bootm.c Kernel unit name specified
2664 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2665 103 common/cmd_bootm.c Found configuration node
2666 104 common/cmd_bootm.c Got kernel subimage node offset
2667 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2668 105 common/cmd_bootm.c Kernel subimage hash verification OK
2669 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2670 106 common/cmd_bootm.c Architecture check OK
2671 -106 common/cmd_bootm.c Kernel subimage has wrong type
2672 107 common/cmd_bootm.c Kernel subimage type OK
2673 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2674 108 common/cmd_bootm.c Got kernel subimage data/size
2675 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2676 -109 common/cmd_bootm.c Can't get kernel subimage type
2677 -110 common/cmd_bootm.c Can't get kernel subimage comp
2678 -111 common/cmd_bootm.c Can't get kernel subimage os
2679 -112 common/cmd_bootm.c Can't get kernel subimage load address
2680 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2682 120 common/image.c Start initial ramdisk verification
2683 -120 common/image.c Ramdisk FIT image has incorrect format
2684 121 common/image.c Ramdisk FIT image has correct format
2685 122 common/image.c No ramdisk subimage unit name, using configuration
2686 -122 common/image.c Can't get configuration for ramdisk subimage
2687 123 common/image.c Ramdisk unit name specified
2688 -124 common/image.c Can't get ramdisk subimage node offset
2689 125 common/image.c Got ramdisk subimage node offset
2690 -125 common/image.c Ramdisk subimage hash verification failed
2691 126 common/image.c Ramdisk subimage hash verification OK
2692 -126 common/image.c Ramdisk subimage for unsupported architecture
2693 127 common/image.c Architecture check OK
2694 -127 common/image.c Can't get ramdisk subimage data/size
2695 128 common/image.c Got ramdisk subimage data/size
2696 129 common/image.c Can't get ramdisk load address
2697 -129 common/image.c Got ramdisk load address
2699 -130 common/cmd_doc.c Incorrect FIT image format
2700 131 common/cmd_doc.c FIT image format OK
2702 -140 common/cmd_ide.c Incorrect FIT image format
2703 141 common/cmd_ide.c FIT image format OK
2705 -150 common/cmd_nand.c Incorrect FIT image format
2706 151 common/cmd_nand.c FIT image format OK
2708 - legacy image format:
2709 CONFIG_IMAGE_FORMAT_LEGACY
2710 enables the legacy image format support in U-Boot.
2713 enabled if CONFIG_FIT_SIGNATURE is not defined.
2715 CONFIG_DISABLE_IMAGE_LEGACY
2716 disable the legacy image format
2718 This define is introduced, as the legacy image format is
2719 enabled per default for backward compatibility.
2721 - Standalone program support:
2722 CONFIG_STANDALONE_LOAD_ADDR
2724 This option defines a board specific value for the
2725 address where standalone program gets loaded, thus
2726 overwriting the architecture dependent default
2729 - Frame Buffer Address:
2732 Define CONFIG_FB_ADDR if you want to use specific
2733 address for frame buffer. This is typically the case
2734 when using a graphics controller has separate video
2735 memory. U-Boot will then place the frame buffer at
2736 the given address instead of dynamically reserving it
2737 in system RAM by calling lcd_setmem(), which grabs
2738 the memory for the frame buffer depending on the
2739 configured panel size.
2741 Please see board_init_f function.
2743 - Automatic software updates via TFTP server
2745 CONFIG_UPDATE_TFTP_CNT_MAX
2746 CONFIG_UPDATE_TFTP_MSEC_MAX
2748 These options enable and control the auto-update feature;
2749 for a more detailed description refer to doc/README.update.
2751 - MTD Support (mtdparts command, UBI support)
2754 Adds the MTD device infrastructure from the Linux kernel.
2755 Needed for mtdparts command support.
2757 CONFIG_MTD_PARTITIONS
2759 Adds the MTD partitioning infrastructure from the Linux
2760 kernel. Needed for UBI support.
2763 CONFIG_UBI_SILENCE_MSG
2765 Make the verbose messages from UBI stop printing. This leaves
2766 warnings and errors enabled.
2769 CONFIG_MTD_UBI_WL_THRESHOLD
2770 This parameter defines the maximum difference between the highest
2771 erase counter value and the lowest erase counter value of eraseblocks
2772 of UBI devices. When this threshold is exceeded, UBI starts performing
2773 wear leveling by means of moving data from eraseblock with low erase
2774 counter to eraseblocks with high erase counter.
2776 The default value should be OK for SLC NAND flashes, NOR flashes and
2777 other flashes which have eraseblock life-cycle 100000 or more.
2778 However, in case of MLC NAND flashes which typically have eraseblock
2779 life-cycle less than 10000, the threshold should be lessened (e.g.,
2780 to 128 or 256, although it does not have to be power of 2).
2784 CONFIG_MTD_UBI_BEB_LIMIT
2785 This option specifies the maximum bad physical eraseblocks UBI
2786 expects on the MTD device (per 1024 eraseblocks). If the
2787 underlying flash does not admit of bad eraseblocks (e.g. NOR
2788 flash), this value is ignored.
2790 NAND datasheets often specify the minimum and maximum NVM
2791 (Number of Valid Blocks) for the flashes' endurance lifetime.
2792 The maximum expected bad eraseblocks per 1024 eraseblocks
2793 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2794 which gives 20 for most NANDs (MaxNVB is basically the total
2795 count of eraseblocks on the chip).
2797 To put it differently, if this value is 20, UBI will try to
2798 reserve about 1.9% of physical eraseblocks for bad blocks
2799 handling. And that will be 1.9% of eraseblocks on the entire
2800 NAND chip, not just the MTD partition UBI attaches. This means
2801 that if you have, say, a NAND flash chip admits maximum 40 bad
2802 eraseblocks, and it is split on two MTD partitions of the same
2803 size, UBI will reserve 40 eraseblocks when attaching a
2808 CONFIG_MTD_UBI_FASTMAP
2809 Fastmap is a mechanism which allows attaching an UBI device
2810 in nearly constant time. Instead of scanning the whole MTD device it
2811 only has to locate a checkpoint (called fastmap) on the device.
2812 The on-flash fastmap contains all information needed to attach
2813 the device. Using fastmap makes only sense on large devices where
2814 attaching by scanning takes long. UBI will not automatically install
2815 a fastmap on old images, but you can set the UBI parameter
2816 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2817 that fastmap-enabled images are still usable with UBI implementations
2818 without fastmap support. On typical flash devices the whole fastmap
2819 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2821 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2822 Set this parameter to enable fastmap automatically on images
2826 CONFIG_MTD_UBI_FM_DEBUG
2827 Enable UBI fastmap debug
2831 CONFIG_UBIFS_SILENCE_MSG
2833 Make the verbose messages from UBIFS stop printing. This leaves
2834 warnings and errors enabled.
2838 Enable building of SPL globally.
2841 LDSCRIPT for linking the SPL binary.
2843 CONFIG_SPL_MAX_FOOTPRINT
2844 Maximum size in memory allocated to the SPL, BSS included.
2845 When defined, the linker checks that the actual memory
2846 used by SPL from _start to __bss_end does not exceed it.
2847 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2848 must not be both defined at the same time.
2851 Maximum size of the SPL image (text, data, rodata, and
2852 linker lists sections), BSS excluded.
2853 When defined, the linker checks that the actual size does
2856 CONFIG_SPL_TEXT_BASE
2857 TEXT_BASE for linking the SPL binary.
2859 CONFIG_SPL_RELOC_TEXT_BASE
2860 Address to relocate to. If unspecified, this is equal to
2861 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2863 CONFIG_SPL_BSS_START_ADDR
2864 Link address for the BSS within the SPL binary.
2866 CONFIG_SPL_BSS_MAX_SIZE
2867 Maximum size in memory allocated to the SPL BSS.
2868 When defined, the linker checks that the actual memory used
2869 by SPL from __bss_start to __bss_end does not exceed it.
2870 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2871 must not be both defined at the same time.
2874 Adress of the start of the stack SPL will use
2876 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2877 When defined, SPL will panic() if the image it has
2878 loaded does not have a signature.
2879 Defining this is useful when code which loads images
2880 in SPL cannot guarantee that absolutely all read errors
2882 An example is the LPC32XX MLC NAND driver, which will
2883 consider that a completely unreadable NAND block is bad,
2884 and thus should be skipped silently.
2886 CONFIG_SPL_RELOC_STACK
2887 Adress of the start of the stack SPL will use after
2888 relocation. If unspecified, this is equal to
2891 CONFIG_SYS_SPL_MALLOC_START
2892 Starting address of the malloc pool used in SPL.
2893 When this option is set the full malloc is used in SPL and
2894 it is set up by spl_init() and before that, the simple malloc()
2895 can be used if CONFIG_SYS_MALLOC_F is defined.
2897 CONFIG_SYS_SPL_MALLOC_SIZE
2898 The size of the malloc pool used in SPL.
2900 CONFIG_SPL_FRAMEWORK
2901 Enable the SPL framework under common/. This framework
2902 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2903 NAND loading of the Linux Kernel.
2906 Enable booting directly to an OS from SPL.
2907 See also: doc/README.falcon
2909 CONFIG_SPL_DISPLAY_PRINT
2910 For ARM, enable an optional function to print more information
2911 about the running system.
2913 CONFIG_SPL_INIT_MINIMAL
2914 Arch init code should be built for a very small image
2916 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2917 Partition on the MMC to load U-Boot from when the MMC is being
2920 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2921 Sector to load kernel uImage from when MMC is being
2922 used in raw mode (for Falcon mode)
2924 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2925 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2926 Sector and number of sectors to load kernel argument
2927 parameters from when MMC is being used in raw mode
2930 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2931 Partition on the MMC to load U-Boot from when the MMC is being
2934 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2935 Filename to read to load U-Boot when reading from filesystem
2937 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2938 Filename to read to load kernel uImage when reading
2939 from filesystem (for Falcon mode)
2941 CONFIG_SPL_FS_LOAD_ARGS_NAME
2942 Filename to read to load kernel argument parameters
2943 when reading from filesystem (for Falcon mode)
2945 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2946 Set this for NAND SPL on PPC mpc83xx targets, so that
2947 start.S waits for the rest of the SPL to load before
2948 continuing (the hardware starts execution after just
2949 loading the first page rather than the full 4K).
2951 CONFIG_SPL_SKIP_RELOCATE
2952 Avoid SPL relocation
2954 CONFIG_SPL_NAND_BASE
2955 Include nand_base.c in the SPL. Requires
2956 CONFIG_SPL_NAND_DRIVERS.
2958 CONFIG_SPL_NAND_DRIVERS
2959 SPL uses normal NAND drivers, not minimal drivers.
2962 Include standard software ECC in the SPL
2964 CONFIG_SPL_NAND_SIMPLE
2965 Support for NAND boot using simple NAND drivers that
2966 expose the cmd_ctrl() interface.
2969 Support for a lightweight UBI (fastmap) scanner and
2972 CONFIG_SPL_NAND_RAW_ONLY
2973 Support to boot only raw u-boot.bin images. Use this only
2974 if you need to save space.
2976 CONFIG_SPL_COMMON_INIT_DDR
2977 Set for common ddr init with serial presence detect in
2980 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2981 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2982 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2983 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2984 CONFIG_SYS_NAND_ECCBYTES
2985 Defines the size and behavior of the NAND that SPL uses
2988 CONFIG_SPL_NAND_BOOT
2989 Add support NAND boot
2991 CONFIG_SYS_NAND_U_BOOT_OFFS
2992 Location in NAND to read U-Boot from
2994 CONFIG_SYS_NAND_U_BOOT_DST
2995 Location in memory to load U-Boot to
2997 CONFIG_SYS_NAND_U_BOOT_SIZE
2998 Size of image to load
3000 CONFIG_SYS_NAND_U_BOOT_START
3001 Entry point in loaded image to jump to
3003 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3004 Define this if you need to first read the OOB and then the
3005 data. This is used, for example, on davinci platforms.
3007 CONFIG_SPL_OMAP3_ID_NAND
3008 Support for an OMAP3-specific set of functions to return the
3009 ID and MFR of the first attached NAND chip, if present.
3011 CONFIG_SPL_RAM_DEVICE
3012 Support for running image already present in ram, in SPL binary
3015 Image offset to which the SPL should be padded before appending
3016 the SPL payload. By default, this is defined as
3017 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3018 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3019 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3022 Final target image containing SPL and payload. Some SPLs
3023 use an arch-specific makefile fragment instead, for
3024 example if more than one image needs to be produced.
3026 CONFIG_FIT_SPL_PRINT
3027 Printing information about a FIT image adds quite a bit of
3028 code to SPL. So this is normally disabled in SPL. Use this
3029 option to re-enable it. This will affect the output of the
3030 bootm command when booting a FIT image.
3034 Enable building of TPL globally.
3037 Image offset to which the TPL should be padded before appending
3038 the TPL payload. By default, this is defined as
3039 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3040 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3041 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3043 - Interrupt support (PPC):
3045 There are common interrupt_init() and timer_interrupt()
3046 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3047 for CPU specific initialization. interrupt_init_cpu()
3048 should set decrementer_count to appropriate value. If
3049 CPU resets decrementer automatically after interrupt
3050 (ppc4xx) it should set decrementer_count to zero.
3051 timer_interrupt() calls timer_interrupt_cpu() for CPU
3052 specific handling. If board has watchdog / status_led
3053 / other_activity_monitor it works automatically from
3054 general timer_interrupt().
3057 Board initialization settings:
3058 ------------------------------
3060 During Initialization u-boot calls a number of board specific functions
3061 to allow the preparation of board specific prerequisites, e.g. pin setup
3062 before drivers are initialized. To enable these callbacks the
3063 following configuration macros have to be defined. Currently this is
3064 architecture specific, so please check arch/your_architecture/lib/board.c
3065 typically in board_init_f() and board_init_r().
3067 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3068 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3069 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3070 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3072 Configuration Settings:
3073 -----------------------
3075 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3076 Optionally it can be defined to support 64-bit memory commands.
3078 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3079 undefine this when you're short of memory.
3081 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3082 width of the commands listed in the 'help' command output.
3084 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3085 prompt for user input.
3087 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3089 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3091 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3093 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3094 the application (usually a Linux kernel) when it is
3097 - CONFIG_SYS_BAUDRATE_TABLE:
3098 List of legal baudrate settings for this board.
3100 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3101 Begin and End addresses of the area used by the
3104 - CONFIG_SYS_ALT_MEMTEST:
3105 Enable an alternate, more extensive memory test.
3107 - CONFIG_SYS_MEMTEST_SCRATCH:
3108 Scratch address used by the alternate memory test
3109 You only need to set this if address zero isn't writeable
3111 - CONFIG_SYS_MEM_RESERVE_SECURE
3112 Only implemented for ARMv8 for now.
3113 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3114 is substracted from total RAM and won't be reported to OS.
3115 This memory can be used as secure memory. A variable
3116 gd->arch.secure_ram is used to track the location. In systems
3117 the RAM base is not zero, or RAM is divided into banks,
3118 this variable needs to be recalcuated to get the address.
3120 - CONFIG_SYS_MEM_TOP_HIDE:
3121 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3122 this specified memory area will get subtracted from the top
3123 (end) of RAM and won't get "touched" at all by U-Boot. By
3124 fixing up gd->ram_size the Linux kernel should gets passed
3125 the now "corrected" memory size and won't touch it either.
3126 This should work for arch/ppc and arch/powerpc. Only Linux
3127 board ports in arch/powerpc with bootwrapper support that
3128 recalculate the memory size from the SDRAM controller setup
3129 will have to get fixed in Linux additionally.
3131 This option can be used as a workaround for the 440EPx/GRx
3132 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3135 WARNING: Please make sure that this value is a multiple of
3136 the Linux page size (normally 4k). If this is not the case,
3137 then the end address of the Linux memory will be located at a
3138 non page size aligned address and this could cause major
3141 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3142 Enable temporary baudrate change while serial download
3144 - CONFIG_SYS_SDRAM_BASE:
3145 Physical start address of SDRAM. _Must_ be 0 here.
3147 - CONFIG_SYS_FLASH_BASE:
3148 Physical start address of Flash memory.
3150 - CONFIG_SYS_MONITOR_BASE:
3151 Physical start address of boot monitor code (set by
3152 make config files to be same as the text base address
3153 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3154 CONFIG_SYS_FLASH_BASE when booting from flash.
3156 - CONFIG_SYS_MONITOR_LEN:
3157 Size of memory reserved for monitor code, used to
3158 determine _at_compile_time_ (!) if the environment is
3159 embedded within the U-Boot image, or in a separate
3162 - CONFIG_SYS_MALLOC_LEN:
3163 Size of DRAM reserved for malloc() use.
3165 - CONFIG_SYS_MALLOC_F_LEN
3166 Size of the malloc() pool for use before relocation. If
3167 this is defined, then a very simple malloc() implementation
3168 will become available before relocation. The address is just
3169 below the global data, and the stack is moved down to make
3172 This feature allocates regions with increasing addresses
3173 within the region. calloc() is supported, but realloc()
3174 is not available. free() is supported but does nothing.
3175 The memory will be freed (or in fact just forgotten) when
3176 U-Boot relocates itself.
3178 - CONFIG_SYS_MALLOC_SIMPLE
3179 Provides a simple and small malloc() and calloc() for those
3180 boards which do not use the full malloc in SPL (which is
3181 enabled with CONFIG_SYS_SPL_MALLOC_START).
3183 - CONFIG_SYS_NONCACHED_MEMORY:
3184 Size of non-cached memory area. This area of memory will be
3185 typically located right below the malloc() area and mapped
3186 uncached in the MMU. This is useful for drivers that would
3187 otherwise require a lot of explicit cache maintenance. For
3188 some drivers it's also impossible to properly maintain the
3189 cache. For example if the regions that need to be flushed
3190 are not a multiple of the cache-line size, *and* padding
3191 cannot be allocated between the regions to align them (i.e.
3192 if the HW requires a contiguous array of regions, and the
3193 size of each region is not cache-aligned), then a flush of
3194 one region may result in overwriting data that hardware has
3195 written to another region in the same cache-line. This can
3196 happen for example in network drivers where descriptors for
3197 buffers are typically smaller than the CPU cache-line (e.g.
3198 16 bytes vs. 32 or 64 bytes).
3200 Non-cached memory is only supported on 32-bit ARM at present.
3202 - CONFIG_SYS_BOOTM_LEN:
3203 Normally compressed uImages are limited to an
3204 uncompressed size of 8 MBytes. If this is not enough,
3205 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3206 to adjust this setting to your needs.
3208 - CONFIG_SYS_BOOTMAPSZ:
3209 Maximum size of memory mapped by the startup code of
3210 the Linux kernel; all data that must be processed by
3211 the Linux kernel (bd_info, boot arguments, FDT blob if
3212 used) must be put below this limit, unless "bootm_low"
3213 environment variable is defined and non-zero. In such case
3214 all data for the Linux kernel must be between "bootm_low"
3215 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3216 variable "bootm_mapsize" will override the value of
3217 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3218 then the value in "bootm_size" will be used instead.
3220 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3221 Enable initrd_high functionality. If defined then the
3222 initrd_high feature is enabled and the bootm ramdisk subcommand
3225 - CONFIG_SYS_BOOT_GET_CMDLINE:
3226 Enables allocating and saving kernel cmdline in space between
3227 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3229 - CONFIG_SYS_BOOT_GET_KBD:
3230 Enables allocating and saving a kernel copy of the bd_info in
3231 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3233 - CONFIG_SYS_MAX_FLASH_BANKS:
3234 Max number of Flash memory banks
3236 - CONFIG_SYS_MAX_FLASH_SECT:
3237 Max number of sectors on a Flash chip
3239 - CONFIG_SYS_FLASH_ERASE_TOUT:
3240 Timeout for Flash erase operations (in ms)
3242 - CONFIG_SYS_FLASH_WRITE_TOUT:
3243 Timeout for Flash write operations (in ms)
3245 - CONFIG_SYS_FLASH_LOCK_TOUT
3246 Timeout for Flash set sector lock bit operation (in ms)
3248 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3249 Timeout for Flash clear lock bits operation (in ms)
3251 - CONFIG_SYS_FLASH_PROTECTION
3252 If defined, hardware flash sectors protection is used
3253 instead of U-Boot software protection.
3255 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3257 Enable TFTP transfers directly to flash memory;
3258 without this option such a download has to be
3259 performed in two steps: (1) download to RAM, and (2)
3260 copy from RAM to flash.
3262 The two-step approach is usually more reliable, since
3263 you can check if the download worked before you erase
3264 the flash, but in some situations (when system RAM is
3265 too limited to allow for a temporary copy of the
3266 downloaded image) this option may be very useful.
3268 - CONFIG_SYS_FLASH_CFI:
3269 Define if the flash driver uses extra elements in the
3270 common flash structure for storing flash geometry.
3272 - CONFIG_FLASH_CFI_DRIVER
3273 This option also enables the building of the cfi_flash driver
3274 in the drivers directory
3276 - CONFIG_FLASH_CFI_MTD
3277 This option enables the building of the cfi_mtd driver
3278 in the drivers directory. The driver exports CFI flash
3281 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3282 Use buffered writes to flash.
3284 - CONFIG_FLASH_SPANSION_S29WS_N
3285 s29ws-n MirrorBit flash has non-standard addresses for buffered
3288 - CONFIG_SYS_FLASH_QUIET_TEST
3289 If this option is defined, the common CFI flash doesn't
3290 print it's warning upon not recognized FLASH banks. This
3291 is useful, if some of the configured banks are only
3292 optionally available.
3294 - CONFIG_FLASH_SHOW_PROGRESS
3295 If defined (must be an integer), print out countdown
3296 digits and dots. Recommended value: 45 (9..1) for 80
3297 column displays, 15 (3..1) for 40 column displays.
3299 - CONFIG_FLASH_VERIFY
3300 If defined, the content of the flash (destination) is compared
3301 against the source after the write operation. An error message
3302 will be printed when the contents are not identical.
3303 Please note that this option is useless in nearly all cases,
3304 since such flash programming errors usually are detected earlier
3305 while unprotecting/erasing/programming. Please only enable
3306 this option if you really know what you are doing.
3308 - CONFIG_SYS_RX_ETH_BUFFER:
3309 Defines the number of Ethernet receive buffers. On some
3310 Ethernet controllers it is recommended to set this value
3311 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3312 buffers can be full shortly after enabling the interface
3313 on high Ethernet traffic.
3314 Defaults to 4 if not defined.
3316 - CONFIG_ENV_MAX_ENTRIES
3318 Maximum number of entries in the hash table that is used
3319 internally to store the environment settings. The default
3320 setting is supposed to be generous and should work in most
3321 cases. This setting can be used to tune behaviour; see
3322 lib/hashtable.c for details.
3324 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3325 - CONFIG_ENV_FLAGS_LIST_STATIC
3326 Enable validation of the values given to environment variables when
3327 calling env set. Variables can be restricted to only decimal,
3328 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3329 the variables can also be restricted to IP address or MAC address.
3331 The format of the list is:
3332 type_attribute = [s|d|x|b|i|m]
3333 access_attribute = [a|r|o|c]
3334 attributes = type_attribute[access_attribute]
3335 entry = variable_name[:attributes]
3338 The type attributes are:
3339 s - String (default)
3342 b - Boolean ([1yYtT|0nNfF])
3346 The access attributes are:
3352 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3353 Define this to a list (string) to define the ".flags"
3354 environment variable in the default or embedded environment.
3356 - CONFIG_ENV_FLAGS_LIST_STATIC
3357 Define this to a list (string) to define validation that
3358 should be done if an entry is not found in the ".flags"
3359 environment variable. To override a setting in the static
3360 list, simply add an entry for the same variable name to the
3363 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3364 regular expression. This allows multiple variables to define the same
3365 flags without explicitly listing them for each variable.
3367 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3368 If defined, don't allow the -f switch to env set override variable
3372 If stdint.h is available with your toolchain you can define this
3373 option to enable it. You can provide option 'USE_STDINT=1' when
3374 building U-Boot to enable this.
3376 The following definitions that deal with the placement and management
3377 of environment data (variable area); in general, we support the
3378 following configurations:
3380 - CONFIG_BUILD_ENVCRC:
3382 Builds up envcrc with the target environment so that external utils
3383 may easily extract it and embed it in final U-Boot images.
3385 BE CAREFUL! The first access to the environment happens quite early
3386 in U-Boot initialization (when we try to get the setting of for the
3387 console baudrate). You *MUST* have mapped your NVRAM area then, or
3390 Please note that even with NVRAM we still use a copy of the
3391 environment in RAM: we could work on NVRAM directly, but we want to
3392 keep settings there always unmodified except somebody uses "saveenv"
3393 to save the current settings.
3395 BE CAREFUL! For some special cases, the local device can not use
3396 "saveenv" command. For example, the local device will get the
3397 environment stored in a remote NOR flash by SRIO or PCIE link,
3398 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3400 - CONFIG_NAND_ENV_DST
3402 Defines address in RAM to which the nand_spl code should copy the
3403 environment. If redundant environment is used, it will be copied to
3404 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3406 Please note that the environment is read-only until the monitor
3407 has been relocated to RAM and a RAM copy of the environment has been
3408 created; also, when using EEPROM you will have to use getenv_f()
3409 until then to read environment variables.
3411 The environment is protected by a CRC32 checksum. Before the monitor
3412 is relocated into RAM, as a result of a bad CRC you will be working
3413 with the compiled-in default environment - *silently*!!! [This is
3414 necessary, because the first environment variable we need is the
3415 "baudrate" setting for the console - if we have a bad CRC, we don't
3416 have any device yet where we could complain.]
3418 Note: once the monitor has been relocated, then it will complain if
3419 the default environment is used; a new CRC is computed as soon as you
3420 use the "saveenv" command to store a valid environment.
3422 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3423 Echo the inverted Ethernet link state to the fault LED.
3425 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3426 also needs to be defined.
3428 - CONFIG_SYS_FAULT_MII_ADDR:
3429 MII address of the PHY to check for the Ethernet link state.
3431 - CONFIG_NS16550_MIN_FUNCTIONS:
3432 Define this if you desire to only have use of the NS16550_init
3433 and NS16550_putc functions for the serial driver located at
3434 drivers/serial/ns16550.c. This option is useful for saving
3435 space for already greatly restricted images, including but not
3436 limited to NAND_SPL configurations.
3438 - CONFIG_DISPLAY_BOARDINFO
3439 Display information about the board that U-Boot is running on
3440 when U-Boot starts up. The board function checkboard() is called
3443 - CONFIG_DISPLAY_BOARDINFO_LATE
3444 Similar to the previous option, but display this information
3445 later, once stdio is running and output goes to the LCD, if
3448 - CONFIG_BOARD_SIZE_LIMIT:
3449 Maximum size of the U-Boot image. When defined, the
3450 build system checks that the actual size does not
3453 Low Level (hardware related) configuration options:
3454 ---------------------------------------------------
3456 - CONFIG_SYS_CACHELINE_SIZE:
3457 Cache Line Size of the CPU.
3459 - CONFIG_SYS_CCSRBAR_DEFAULT:
3460 Default (power-on reset) physical address of CCSR on Freescale
3463 - CONFIG_SYS_CCSRBAR:
3464 Virtual address of CCSR. On a 32-bit build, this is typically
3465 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3467 - CONFIG_SYS_CCSRBAR_PHYS:
3468 Physical address of CCSR. CCSR can be relocated to a new
3469 physical address, if desired. In this case, this macro should
3470 be set to that address. Otherwise, it should be set to the
3471 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3472 is typically relocated on 36-bit builds. It is recommended
3473 that this macro be defined via the _HIGH and _LOW macros:
3475 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3476 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3478 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3479 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3480 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3481 used in assembly code, so it must not contain typecasts or
3482 integer size suffixes (e.g. "ULL").
3484 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3485 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3486 used in assembly code, so it must not contain typecasts or
3487 integer size suffixes (e.g. "ULL").
3489 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3490 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3491 forced to a value that ensures that CCSR is not relocated.
3493 - Floppy Disk Support:
3494 CONFIG_SYS_FDC_DRIVE_NUMBER
3496 the default drive number (default value 0)
3498 CONFIG_SYS_ISA_IO_STRIDE
3500 defines the spacing between FDC chipset registers
3503 CONFIG_SYS_ISA_IO_OFFSET
3505 defines the offset of register from address. It
3506 depends on which part of the data bus is connected to
3507 the FDC chipset. (default value 0)
3509 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3510 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3513 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3514 fdc_hw_init() is called at the beginning of the FDC
3515 setup. fdc_hw_init() must be provided by the board
3516 source code. It is used to make hardware-dependent
3520 Most IDE controllers were designed to be connected with PCI
3521 interface. Only few of them were designed for AHB interface.
3522 When software is doing ATA command and data transfer to
3523 IDE devices through IDE-AHB controller, some additional
3524 registers accessing to these kind of IDE-AHB controller
3527 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3528 DO NOT CHANGE unless you know exactly what you're
3529 doing! (11-4) [MPC8xx systems only]
3531 - CONFIG_SYS_INIT_RAM_ADDR:
3533 Start address of memory area that can be used for
3534 initial data and stack; please note that this must be
3535 writable memory that is working WITHOUT special
3536 initialization, i. e. you CANNOT use normal RAM which
3537 will become available only after programming the
3538 memory controller and running certain initialization
3541 U-Boot uses the following memory types:
3542 - MPC8xx: IMMR (internal memory of the CPU)
3544 - CONFIG_SYS_GBL_DATA_OFFSET:
3546 Offset of the initial data structure in the memory
3547 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3548 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3549 data is located at the end of the available space
3550 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3551 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3552 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3553 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3556 On the MPC824X (or other systems that use the data
3557 cache for initial memory) the address chosen for
3558 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3559 point to an otherwise UNUSED address space between
3560 the top of RAM and the start of the PCI space.
3562 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3564 - CONFIG_SYS_OR_TIMING_SDRAM:
3567 - CONFIG_SYS_MAMR_PTA:
3568 periodic timer for refresh
3570 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3571 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3572 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3573 CONFIG_SYS_BR1_PRELIM:
3574 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3576 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3577 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3578 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3579 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3581 - CONFIG_PCI_ENUM_ONLY
3582 Only scan through and get the devices on the buses.
3583 Don't do any setup work, presumably because someone or
3584 something has already done it, and we don't need to do it
3585 a second time. Useful for platforms that are pre-booted
3586 by coreboot or similar.
3588 - CONFIG_PCI_INDIRECT_BRIDGE:
3589 Enable support for indirect PCI bridges.
3592 Chip has SRIO or not
3595 Board has SRIO 1 port available
3598 Board has SRIO 2 port available
3600 - CONFIG_SRIO_PCIE_BOOT_MASTER
3601 Board can support master function for Boot from SRIO and PCIE
3603 - CONFIG_SYS_SRIOn_MEM_VIRT:
3604 Virtual Address of SRIO port 'n' memory region
3606 - CONFIG_SYS_SRIOn_MEM_PHYS:
3607 Physical Address of SRIO port 'n' memory region
3609 - CONFIG_SYS_SRIOn_MEM_SIZE:
3610 Size of SRIO port 'n' memory region
3612 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3613 Defined to tell the NAND controller that the NAND chip is using
3615 Not all NAND drivers use this symbol.
3616 Example of drivers that use it:
3617 - drivers/mtd/nand/ndfc.c
3618 - drivers/mtd/nand/mxc_nand.c
3620 - CONFIG_SYS_NDFC_EBC0_CFG
3621 Sets the EBC0_CFG register for the NDFC. If not defined
3622 a default value will be used.
3625 Get DDR timing information from an I2C EEPROM. Common
3626 with pluggable memory modules such as SODIMMs
3629 I2C address of the SPD EEPROM
3631 - CONFIG_SYS_SPD_BUS_NUM
3632 If SPD EEPROM is on an I2C bus other than the first
3633 one, specify here. Note that the value must resolve
3634 to something your driver can deal with.
3636 - CONFIG_SYS_DDR_RAW_TIMING
3637 Get DDR timing information from other than SPD. Common with
3638 soldered DDR chips onboard without SPD. DDR raw timing
3639 parameters are extracted from datasheet and hard-coded into
3640 header files or board specific files.
3642 - CONFIG_FSL_DDR_INTERACTIVE
3643 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3645 - CONFIG_FSL_DDR_SYNC_REFRESH
3646 Enable sync of refresh for multiple controllers.
3648 - CONFIG_FSL_DDR_BIST
3649 Enable built-in memory test for Freescale DDR controllers.
3651 - CONFIG_SYS_83XX_DDR_USES_CS0
3652 Only for 83xx systems. If specified, then DDR should
3653 be configured using CS0 and CS1 instead of CS2 and CS3.
3656 Enable RMII mode for all FECs.
3657 Note that this is a global option, we can't
3658 have one FEC in standard MII mode and another in RMII mode.
3660 - CONFIG_CRC32_VERIFY
3661 Add a verify option to the crc32 command.
3664 => crc32 -v <address> <count> <crc32>
3666 Where address/count indicate a memory area
3667 and crc32 is the correct crc32 which the
3671 Add the "loopw" memory command. This only takes effect if
3672 the memory commands are activated globally (CONFIG_CMD_MEMORY).
3675 Add the "mdc" and "mwc" memory commands. These are cyclic
3680 This command will print 4 bytes (10,11,12,13) each 500 ms.
3682 => mwc.l 100 12345678 10
3683 This command will write 12345678 to address 100 all 10 ms.
3685 This only takes effect if the memory commands are activated
3686 globally (CONFIG_CMD_MEMORY).
3688 - CONFIG_SKIP_LOWLEVEL_INIT
3689 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3690 low level initializations (like setting up the memory
3691 controller) are omitted and/or U-Boot does not
3692 relocate itself into RAM.
3694 Normally this variable MUST NOT be defined. The only
3695 exception is when U-Boot is loaded (to RAM) by some
3696 other boot loader or by a debugger which performs
3697 these initializations itself.
3699 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3700 [ARM926EJ-S only] This allows just the call to lowlevel_init()
3701 to be skipped. The normal CP15 init (such as enabling the
3702 instruction cache) is still performed.
3705 Modifies the behaviour of start.S when compiling a loader
3706 that is executed before the actual U-Boot. E.g. when
3707 compiling a NAND SPL.
3710 Modifies the behaviour of start.S when compiling a loader
3711 that is executed after the SPL and before the actual U-Boot.
3712 It is loaded by the SPL.
3714 - CONFIG_SYS_MPC85XX_NO_RESETVEC
3715 Only for 85xx systems. If this variable is specified, the section
3716 .resetvec is not kept and the section .bootpg is placed in the
3717 previous 4k of the .text section.
3719 - CONFIG_ARCH_MAP_SYSMEM
3720 Generally U-Boot (and in particular the md command) uses
3721 effective address. It is therefore not necessary to regard
3722 U-Boot address as virtual addresses that need to be translated
3723 to physical addresses. However, sandbox requires this, since
3724 it maintains its own little RAM buffer which contains all
3725 addressable memory. This option causes some memory accesses
3726 to be mapped through map_sysmem() / unmap_sysmem().
3728 - CONFIG_X86_RESET_VECTOR
3729 If defined, the x86 reset vector code is included. This is not
3730 needed when U-Boot is running from Coreboot.
3732 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
3733 Enables the RTC32K OSC on AM33xx based plattforms
3735 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3736 Option to disable subpage write in NAND driver
3737 driver that uses this:
3738 drivers/mtd/nand/davinci_nand.c
3740 Freescale QE/FMAN Firmware Support:
3741 -----------------------------------
3743 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3744 loading of "firmware", which is encoded in the QE firmware binary format.
3745 This firmware often needs to be loaded during U-Boot booting, so macros
3746 are used to identify the storage device (NOR flash, SPI, etc) and the address
3749 - CONFIG_SYS_FMAN_FW_ADDR
3750 The address in the storage device where the FMAN microcode is located. The
3751 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3754 - CONFIG_SYS_QE_FW_ADDR
3755 The address in the storage device where the QE microcode is located. The
3756 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3759 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3760 The maximum possible size of the firmware. The firmware binary format
3761 has a field that specifies the actual size of the firmware, but it
3762 might not be possible to read any part of the firmware unless some
3763 local storage is allocated to hold the entire firmware first.
3765 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3766 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3767 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3768 virtual address in NOR flash.
3770 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3771 Specifies that QE/FMAN firmware is located in NAND flash.
3772 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3774 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3775 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3776 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3778 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3779 Specifies that QE/FMAN firmware is located in the remote (master)
3780 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3781 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3782 window->master inbound window->master LAW->the ucode address in
3783 master's memory space.
3785 Freescale Layerscape Management Complex Firmware Support:
3786 ---------------------------------------------------------
3787 The Freescale Layerscape Management Complex (MC) supports the loading of
3789 This firmware often needs to be loaded during U-Boot booting, so macros
3790 are used to identify the storage device (NOR flash, SPI, etc) and the address
3793 - CONFIG_FSL_MC_ENET
3794 Enable the MC driver for Layerscape SoCs.
3796 Freescale Layerscape Debug Server Support:
3797 -------------------------------------------
3798 The Freescale Layerscape Debug Server Support supports the loading of
3799 "Debug Server firmware" and triggering SP boot-rom.
3800 This firmware often needs to be loaded during U-Boot booting.
3802 - CONFIG_SYS_MC_RSV_MEM_ALIGN
3803 Define alignment of reserved memory MC requires
3808 In order to achieve reproducible builds, timestamps used in the U-Boot build
3809 process have to be set to a fixed value.
3811 This is done using the SOURCE_DATE_EPOCH environment variable.
3812 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3813 option for U-Boot or an environment variable in U-Boot.
3815 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3817 Building the Software:
3818 ======================
3820 Building U-Boot has been tested in several native build environments
3821 and in many different cross environments. Of course we cannot support
3822 all possibly existing versions of cross development tools in all
3823 (potentially obsolete) versions. In case of tool chain problems we
3824 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3825 which is extensively used to build and test U-Boot.
3827 If you are not using a native environment, it is assumed that you
3828 have GNU cross compiling tools available in your path. In this case,
3829 you must set the environment variable CROSS_COMPILE in your shell.
3830 Note that no changes to the Makefile or any other source files are
3831 necessary. For example using the ELDK on a 4xx CPU, please enter:
3833 $ CROSS_COMPILE=ppc_4xx-
3834 $ export CROSS_COMPILE
3836 Note: If you wish to generate Windows versions of the utilities in
3837 the tools directory you can use the MinGW toolchain
3838 (http://www.mingw.org). Set your HOST tools to the MinGW
3839 toolchain and execute 'make tools'. For example:
3841 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3843 Binaries such as tools/mkimage.exe will be created which can
3844 be executed on computers running Windows.
3846 U-Boot is intended to be simple to build. After installing the
3847 sources you must configure U-Boot for one specific board type. This
3852 where "NAME_defconfig" is the name of one of the existing configu-
3853 rations; see boards.cfg for supported names.
3855 Note: for some board special configuration names may exist; check if
3856 additional information is available from the board vendor; for
3857 instance, the TQM823L systems are available without (standard)
3858 or with LCD support. You can select such additional "features"
3859 when choosing the configuration, i. e.
3861 make TQM823L_defconfig
3862 - will configure for a plain TQM823L, i. e. no LCD support
3864 make TQM823L_LCD_defconfig
3865 - will configure for a TQM823L with U-Boot console on LCD
3870 Finally, type "make all", and you should get some working U-Boot
3871 images ready for download to / installation on your system:
3873 - "u-boot.bin" is a raw binary image
3874 - "u-boot" is an image in ELF binary format
3875 - "u-boot.srec" is in Motorola S-Record format
3877 By default the build is performed locally and the objects are saved
3878 in the source directory. One of the two methods can be used to change
3879 this behavior and build U-Boot to some external directory:
3881 1. Add O= to the make command line invocations:
3883 make O=/tmp/build distclean
3884 make O=/tmp/build NAME_defconfig
3885 make O=/tmp/build all
3887 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
3889 export KBUILD_OUTPUT=/tmp/build
3894 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
3898 Please be aware that the Makefiles assume you are using GNU make, so
3899 for instance on NetBSD you might need to use "gmake" instead of
3903 If the system board that you have is not listed, then you will need
3904 to port U-Boot to your hardware platform. To do this, follow these
3907 1. Create a new directory to hold your board specific code. Add any
3908 files you need. In your board directory, you will need at least
3909 the "Makefile" and a "<board>.c".
3910 2. Create a new configuration file "include/configs/<board>.h" for
3912 3. If you're porting U-Boot to a new CPU, then also create a new
3913 directory to hold your CPU specific code. Add any files you need.
3914 4. Run "make <board>_defconfig" with your new name.
3915 5. Type "make", and you should get a working "u-boot.srec" file
3916 to be installed on your target system.
3917 6. Debug and solve any problems that might arise.
3918 [Of course, this last step is much harder than it sounds.]
3921 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3922 ==============================================================
3924 If you have modified U-Boot sources (for instance added a new board
3925 or support for new devices, a new CPU, etc.) you are expected to
3926 provide feedback to the other developers. The feedback normally takes
3927 the form of a "patch", i. e. a context diff against a certain (latest
3928 official or latest in the git repository) version of U-Boot sources.
3930 But before you submit such a patch, please verify that your modifi-
3931 cation did not break existing code. At least make sure that *ALL* of
3932 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3933 just run the buildman script (tools/buildman/buildman), which will
3934 configure and build U-Boot for ALL supported system. Be warned, this
3935 will take a while. Please see the buildman README, or run 'buildman -H'
3939 See also "U-Boot Porting Guide" below.
3942 Monitor Commands - Overview:
3943 ============================
3945 go - start application at address 'addr'
3946 run - run commands in an environment variable
3947 bootm - boot application image from memory
3948 bootp - boot image via network using BootP/TFTP protocol
3949 bootz - boot zImage from memory
3950 tftpboot- boot image via network using TFTP protocol
3951 and env variables "ipaddr" and "serverip"
3952 (and eventually "gatewayip")
3953 tftpput - upload a file via network using TFTP protocol
3954 rarpboot- boot image via network using RARP/TFTP protocol
3955 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3956 loads - load S-Record file over serial line
3957 loadb - load binary file over serial line (kermit mode)
3959 mm - memory modify (auto-incrementing)
3960 nm - memory modify (constant address)
3961 mw - memory write (fill)
3963 cmp - memory compare
3964 crc32 - checksum calculation
3965 i2c - I2C sub-system
3966 sspi - SPI utility commands
3967 base - print or set address offset
3968 printenv- print environment variables
3969 setenv - set environment variables
3970 saveenv - save environment variables to persistent storage
3971 protect - enable or disable FLASH write protection
3972 erase - erase FLASH memory
3973 flinfo - print FLASH memory information
3974 nand - NAND memory operations (see doc/README.nand)
3975 bdinfo - print Board Info structure
3976 iminfo - print header information for application image
3977 coninfo - print console devices and informations
3978 ide - IDE sub-system
3979 loop - infinite loop on address range
3980 loopw - infinite write loop on address range
3981 mtest - simple RAM test
3982 icache - enable or disable instruction cache
3983 dcache - enable or disable data cache
3984 reset - Perform RESET of the CPU
3985 echo - echo args to console
3986 version - print monitor version
3987 help - print online help
3988 ? - alias for 'help'
3991 Monitor Commands - Detailed Description:
3992 ========================================
3996 For now: just type "help <command>".
3999 Environment Variables:
4000 ======================
4002 U-Boot supports user configuration using Environment Variables which
4003 can be made persistent by saving to Flash memory.
4005 Environment Variables are set using "setenv", printed using
4006 "printenv", and saved to Flash using "saveenv". Using "setenv"
4007 without a value can be used to delete a variable from the
4008 environment. As long as you don't save the environment you are
4009 working with an in-memory copy. In case the Flash area containing the
4010 environment is erased by accident, a default environment is provided.
4012 Some configuration options can be set using Environment Variables.
4014 List of environment variables (most likely not complete):
4016 baudrate - see CONFIG_BAUDRATE
4018 bootdelay - see CONFIG_BOOTDELAY
4020 bootcmd - see CONFIG_BOOTCOMMAND
4022 bootargs - Boot arguments when booting an RTOS image
4024 bootfile - Name of the image to load with TFTP
4026 bootm_low - Memory range available for image processing in the bootm
4027 command can be restricted. This variable is given as
4028 a hexadecimal number and defines lowest address allowed
4029 for use by the bootm command. See also "bootm_size"
4030 environment variable. Address defined by "bootm_low" is
4031 also the base of the initial memory mapping for the Linux
4032 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4035 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4036 This variable is given as a hexadecimal number and it
4037 defines the size of the memory region starting at base
4038 address bootm_low that is accessible by the Linux kernel
4039 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4040 as the default value if it is defined, and bootm_size is
4043 bootm_size - Memory range available for image processing in the bootm
4044 command can be restricted. This variable is given as
4045 a hexadecimal number and defines the size of the region
4046 allowed for use by the bootm command. See also "bootm_low"
4047 environment variable.
4049 updatefile - Location of the software update file on a TFTP server, used
4050 by the automatic software update feature. Please refer to
4051 documentation in doc/README.update for more details.
4053 autoload - if set to "no" (any string beginning with 'n'),
4054 "bootp" will just load perform a lookup of the
4055 configuration from the BOOTP server, but not try to
4056 load any image using TFTP
4058 autostart - if set to "yes", an image loaded using the "bootp",
4059 "rarpboot", "tftpboot" or "diskboot" commands will
4060 be automatically started (by internally calling
4063 If set to "no", a standalone image passed to the
4064 "bootm" command will be copied to the load address
4065 (and eventually uncompressed), but NOT be started.
4066 This can be used to load and uncompress arbitrary
4069 fdt_high - if set this restricts the maximum address that the
4070 flattened device tree will be copied into upon boot.
4071 For example, if you have a system with 1 GB memory
4072 at physical address 0x10000000, while Linux kernel
4073 only recognizes the first 704 MB as low memory, you
4074 may need to set fdt_high as 0x3C000000 to have the
4075 device tree blob be copied to the maximum address
4076 of the 704 MB low memory, so that Linux kernel can
4077 access it during the boot procedure.
4079 If this is set to the special value 0xFFFFFFFF then
4080 the fdt will not be copied at all on boot. For this
4081 to work it must reside in writable memory, have
4082 sufficient padding on the end of it for u-boot to
4083 add the information it needs into it, and the memory
4084 must be accessible by the kernel.
4086 fdtcontroladdr- if set this is the address of the control flattened
4087 device tree used by U-Boot when CONFIG_OF_CONTROL is
4090 i2cfast - (PPC405GP|PPC405EP only)
4091 if set to 'y' configures Linux I2C driver for fast
4092 mode (400kHZ). This environment variable is used in
4093 initialization code. So, for changes to be effective
4094 it must be saved and board must be reset.
4096 initrd_high - restrict positioning of initrd images:
4097 If this variable is not set, initrd images will be
4098 copied to the highest possible address in RAM; this
4099 is usually what you want since it allows for
4100 maximum initrd size. If for some reason you want to
4101 make sure that the initrd image is loaded below the
4102 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4103 variable to a value of "no" or "off" or "0".
4104 Alternatively, you can set it to a maximum upper
4105 address to use (U-Boot will still check that it
4106 does not overwrite the U-Boot stack and data).
4108 For instance, when you have a system with 16 MB
4109 RAM, and want to reserve 4 MB from use by Linux,
4110 you can do this by adding "mem=12M" to the value of
4111 the "bootargs" variable. However, now you must make
4112 sure that the initrd image is placed in the first
4113 12 MB as well - this can be done with
4115 setenv initrd_high 00c00000
4117 If you set initrd_high to 0xFFFFFFFF, this is an
4118 indication to U-Boot that all addresses are legal
4119 for the Linux kernel, including addresses in flash
4120 memory. In this case U-Boot will NOT COPY the
4121 ramdisk at all. This may be useful to reduce the
4122 boot time on your system, but requires that this
4123 feature is supported by your Linux kernel.
4125 ipaddr - IP address; needed for tftpboot command
4127 loadaddr - Default load address for commands like "bootp",
4128 "rarpboot", "tftpboot", "loadb" or "diskboot"
4130 loads_echo - see CONFIG_LOADS_ECHO
4132 serverip - TFTP server IP address; needed for tftpboot command
4134 bootretry - see CONFIG_BOOT_RETRY_TIME
4136 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4138 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4140 ethprime - controls which interface is used first.
4142 ethact - controls which interface is currently active.
4143 For example you can do the following
4145 => setenv ethact FEC
4146 => ping 192.168.0.1 # traffic sent on FEC
4147 => setenv ethact SCC
4148 => ping 10.0.0.1 # traffic sent on SCC
4150 ethrotate - When set to "no" U-Boot does not go through all
4151 available network interfaces.
4152 It just stays at the currently selected interface.
4154 netretry - When set to "no" each network operation will
4155 either succeed or fail without retrying.
4156 When set to "once" the network operation will
4157 fail when all the available network interfaces
4158 are tried once without success.
4159 Useful on scripts which control the retry operation
4162 npe_ucode - set load address for the NPE microcode
4164 silent_linux - If set then Linux will be told to boot silently, by
4165 changing the console to be empty. If "yes" it will be
4166 made silent. If "no" it will not be made silent. If
4167 unset, then it will be made silent if the U-Boot console
4170 tftpsrcp - If this is set, the value is used for TFTP's
4173 tftpdstp - If this is set, the value is used for TFTP's UDP
4174 destination port instead of the Well Know Port 69.
4176 tftpblocksize - Block size to use for TFTP transfers; if not set,
4177 we use the TFTP server's default block size
4179 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4180 seconds, minimum value is 1000 = 1 second). Defines
4181 when a packet is considered to be lost so it has to
4182 be retransmitted. The default is 5000 = 5 seconds.
4183 Lowering this value may make downloads succeed
4184 faster in networks with high packet loss rates or
4185 with unreliable TFTP servers.
4187 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4188 unit, minimum value = 0). Defines how many timeouts
4189 can happen during a single file transfer before that
4190 transfer is aborted. The default is 10, and 0 means
4191 'no timeouts allowed'. Increasing this value may help
4192 downloads succeed with high packet loss rates, or with
4193 unreliable TFTP servers or client hardware.
4195 vlan - When set to a value < 4095 the traffic over
4196 Ethernet is encapsulated/received over 802.1q
4199 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4200 Unsigned value, in milliseconds. If not set, the period will
4201 be either the default (28000), or a value based on
4202 CONFIG_NET_RETRY_COUNT, if defined. This value has
4203 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4205 The following image location variables contain the location of images
4206 used in booting. The "Image" column gives the role of the image and is
4207 not an environment variable name. The other columns are environment
4208 variable names. "File Name" gives the name of the file on a TFTP
4209 server, "RAM Address" gives the location in RAM the image will be
4210 loaded to, and "Flash Location" gives the image's address in NOR
4211 flash or offset in NAND flash.
4213 *Note* - these variables don't have to be defined for all boards, some
4214 boards currently use other variables for these purposes, and some
4215 boards use these variables for other purposes.
4217 Image File Name RAM Address Flash Location
4218 ----- --------- ----------- --------------
4219 u-boot u-boot u-boot_addr_r u-boot_addr
4220 Linux kernel bootfile kernel_addr_r kernel_addr
4221 device tree blob fdtfile fdt_addr_r fdt_addr
4222 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4224 The following environment variables may be used and automatically
4225 updated by the network boot commands ("bootp" and "rarpboot"),
4226 depending the information provided by your boot server:
4228 bootfile - see above
4229 dnsip - IP address of your Domain Name Server
4230 dnsip2 - IP address of your secondary Domain Name Server
4231 gatewayip - IP address of the Gateway (Router) to use
4232 hostname - Target hostname
4234 netmask - Subnet Mask
4235 rootpath - Pathname of the root filesystem on the NFS server
4236 serverip - see above
4239 There are two special Environment Variables:
4241 serial# - contains hardware identification information such
4242 as type string and/or serial number
4243 ethaddr - Ethernet address
4245 These variables can be set only once (usually during manufacturing of
4246 the board). U-Boot refuses to delete or overwrite these variables
4247 once they have been set once.
4250 Further special Environment Variables:
4252 ver - Contains the U-Boot version string as printed
4253 with the "version" command. This variable is
4254 readonly (see CONFIG_VERSION_VARIABLE).
4257 Please note that changes to some configuration parameters may take
4258 only effect after the next boot (yes, that's just like Windoze :-).
4261 Callback functions for environment variables:
4262 ---------------------------------------------
4264 For some environment variables, the behavior of u-boot needs to change
4265 when their values are changed. This functionality allows functions to
4266 be associated with arbitrary variables. On creation, overwrite, or
4267 deletion, the callback will provide the opportunity for some side
4268 effect to happen or for the change to be rejected.
4270 The callbacks are named and associated with a function using the
4271 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4273 These callbacks are associated with variables in one of two ways. The
4274 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4275 in the board configuration to a string that defines a list of
4276 associations. The list must be in the following format:
4278 entry = variable_name[:callback_name]
4281 If the callback name is not specified, then the callback is deleted.
4282 Spaces are also allowed anywhere in the list.
4284 Callbacks can also be associated by defining the ".callbacks" variable
4285 with the same list format above. Any association in ".callbacks" will
4286 override any association in the static list. You can define
4287 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4288 ".callbacks" environment variable in the default or embedded environment.
4290 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4291 regular expression. This allows multiple variables to be connected to
4292 the same callback without explicitly listing them all out.
4295 Command Line Parsing:
4296 =====================
4298 There are two different command line parsers available with U-Boot:
4299 the old "simple" one, and the much more powerful "hush" shell:
4301 Old, simple command line parser:
4302 --------------------------------
4304 - supports environment variables (through setenv / saveenv commands)
4305 - several commands on one line, separated by ';'
4306 - variable substitution using "... ${name} ..." syntax
4307 - special characters ('$', ';') can be escaped by prefixing with '\',
4309 setenv bootcmd bootm \${address}
4310 - You can also escape text by enclosing in single apostrophes, for example:
4311 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4316 - similar to Bourne shell, with control structures like
4317 if...then...else...fi, for...do...done; while...do...done,
4318 until...do...done, ...
4319 - supports environment ("global") variables (through setenv / saveenv
4320 commands) and local shell variables (through standard shell syntax
4321 "name=value"); only environment variables can be used with "run"
4327 (1) If a command line (or an environment variable executed by a "run"
4328 command) contains several commands separated by semicolon, and
4329 one of these commands fails, then the remaining commands will be
4332 (2) If you execute several variables with one call to run (i. e.
4333 calling run with a list of variables as arguments), any failing
4334 command will cause "run" to terminate, i. e. the remaining
4335 variables are not executed.
4337 Note for Redundant Ethernet Interfaces:
4338 =======================================
4340 Some boards come with redundant Ethernet interfaces; U-Boot supports
4341 such configurations and is capable of automatic selection of a
4342 "working" interface when needed. MAC assignment works as follows:
4344 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4345 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4346 "eth1addr" (=>eth1), "eth2addr", ...
4348 If the network interface stores some valid MAC address (for instance
4349 in SROM), this is used as default address if there is NO correspon-
4350 ding setting in the environment; if the corresponding environment
4351 variable is set, this overrides the settings in the card; that means:
4353 o If the SROM has a valid MAC address, and there is no address in the
4354 environment, the SROM's address is used.
4356 o If there is no valid address in the SROM, and a definition in the
4357 environment exists, then the value from the environment variable is
4360 o If both the SROM and the environment contain a MAC address, and
4361 both addresses are the same, this MAC address is used.
4363 o If both the SROM and the environment contain a MAC address, and the
4364 addresses differ, the value from the environment is used and a
4367 o If neither SROM nor the environment contain a MAC address, an error
4368 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4369 a random, locally-assigned MAC is used.
4371 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4372 will be programmed into hardware as part of the initialization process. This
4373 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4374 The naming convention is as follows:
4375 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4380 U-Boot is capable of booting (and performing other auxiliary operations on)
4381 images in two formats:
4383 New uImage format (FIT)
4384 -----------------------
4386 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4387 to Flattened Device Tree). It allows the use of images with multiple
4388 components (several kernels, ramdisks, etc.), with contents protected by
4389 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4395 Old image format is based on binary files which can be basically anything,
4396 preceded by a special header; see the definitions in include/image.h for
4397 details; basically, the header defines the following image properties:
4399 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4400 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4401 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4402 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4404 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4405 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4406 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4407 * Compression Type (uncompressed, gzip, bzip2)
4413 The header is marked by a special Magic Number, and both the header
4414 and the data portions of the image are secured against corruption by
4421 Although U-Boot should support any OS or standalone application
4422 easily, the main focus has always been on Linux during the design of
4425 U-Boot includes many features that so far have been part of some
4426 special "boot loader" code within the Linux kernel. Also, any
4427 "initrd" images to be used are no longer part of one big Linux image;
4428 instead, kernel and "initrd" are separate images. This implementation
4429 serves several purposes:
4431 - the same features can be used for other OS or standalone
4432 applications (for instance: using compressed images to reduce the
4433 Flash memory footprint)
4435 - it becomes much easier to port new Linux kernel versions because
4436 lots of low-level, hardware dependent stuff are done by U-Boot
4438 - the same Linux kernel image can now be used with different "initrd"
4439 images; of course this also means that different kernel images can
4440 be run with the same "initrd". This makes testing easier (you don't
4441 have to build a new "zImage.initrd" Linux image when you just
4442 change a file in your "initrd"). Also, a field-upgrade of the
4443 software is easier now.
4449 Porting Linux to U-Boot based systems:
4450 ---------------------------------------
4452 U-Boot cannot save you from doing all the necessary modifications to
4453 configure the Linux device drivers for use with your target hardware
4454 (no, we don't intend to provide a full virtual machine interface to
4457 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4459 Just make sure your machine specific header file (for instance
4460 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4461 Information structure as we define in include/asm-<arch>/u-boot.h,
4462 and make sure that your definition of IMAP_ADDR uses the same value
4463 as your U-Boot configuration in CONFIG_SYS_IMMR.
4465 Note that U-Boot now has a driver model, a unified model for drivers.
4466 If you are adding a new driver, plumb it into driver model. If there
4467 is no uclass available, you are encouraged to create one. See
4471 Configuring the Linux kernel:
4472 -----------------------------
4474 No specific requirements for U-Boot. Make sure you have some root
4475 device (initial ramdisk, NFS) for your target system.
4478 Building a Linux Image:
4479 -----------------------
4481 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4482 not used. If you use recent kernel source, a new build target
4483 "uImage" will exist which automatically builds an image usable by
4484 U-Boot. Most older kernels also have support for a "pImage" target,
4485 which was introduced for our predecessor project PPCBoot and uses a
4486 100% compatible format.
4490 make TQM850L_defconfig
4495 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4496 encapsulate a compressed Linux kernel image with header information,
4497 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4499 * build a standard "vmlinux" kernel image (in ELF binary format):
4501 * convert the kernel into a raw binary image:
4503 ${CROSS_COMPILE}-objcopy -O binary \
4504 -R .note -R .comment \
4505 -S vmlinux linux.bin
4507 * compress the binary image:
4511 * package compressed binary image for U-Boot:
4513 mkimage -A ppc -O linux -T kernel -C gzip \
4514 -a 0 -e 0 -n "Linux Kernel Image" \
4515 -d linux.bin.gz uImage
4518 The "mkimage" tool can also be used to create ramdisk images for use
4519 with U-Boot, either separated from the Linux kernel image, or
4520 combined into one file. "mkimage" encapsulates the images with a 64
4521 byte header containing information about target architecture,
4522 operating system, image type, compression method, entry points, time
4523 stamp, CRC32 checksums, etc.
4525 "mkimage" can be called in two ways: to verify existing images and
4526 print the header information, or to build new images.
4528 In the first form (with "-l" option) mkimage lists the information
4529 contained in the header of an existing U-Boot image; this includes
4530 checksum verification:
4532 tools/mkimage -l image
4533 -l ==> list image header information
4535 The second form (with "-d" option) is used to build a U-Boot image
4536 from a "data file" which is used as image payload:
4538 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4539 -n name -d data_file image
4540 -A ==> set architecture to 'arch'
4541 -O ==> set operating system to 'os'
4542 -T ==> set image type to 'type'
4543 -C ==> set compression type 'comp'
4544 -a ==> set load address to 'addr' (hex)
4545 -e ==> set entry point to 'ep' (hex)
4546 -n ==> set image name to 'name'
4547 -d ==> use image data from 'datafile'
4549 Right now, all Linux kernels for PowerPC systems use the same load
4550 address (0x00000000), but the entry point address depends on the
4553 - 2.2.x kernels have the entry point at 0x0000000C,
4554 - 2.3.x and later kernels have the entry point at 0x00000000.
4556 So a typical call to build a U-Boot image would read:
4558 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4559 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4560 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4561 > examples/uImage.TQM850L
4562 Image Name: 2.4.4 kernel for TQM850L
4563 Created: Wed Jul 19 02:34:59 2000
4564 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4565 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4566 Load Address: 0x00000000
4567 Entry Point: 0x00000000
4569 To verify the contents of the image (or check for corruption):
4571 -> tools/mkimage -l examples/uImage.TQM850L
4572 Image Name: 2.4.4 kernel for TQM850L
4573 Created: Wed Jul 19 02:34:59 2000
4574 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4575 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4576 Load Address: 0x00000000
4577 Entry Point: 0x00000000
4579 NOTE: for embedded systems where boot time is critical you can trade
4580 speed for memory and install an UNCOMPRESSED image instead: this
4581 needs more space in Flash, but boots much faster since it does not
4582 need to be uncompressed:
4584 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4585 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4586 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4587 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4588 > examples/uImage.TQM850L-uncompressed
4589 Image Name: 2.4.4 kernel for TQM850L
4590 Created: Wed Jul 19 02:34:59 2000
4591 Image Type: PowerPC Linux Kernel Image (uncompressed)
4592 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4593 Load Address: 0x00000000
4594 Entry Point: 0x00000000
4597 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4598 when your kernel is intended to use an initial ramdisk:
4600 -> tools/mkimage -n 'Simple Ramdisk Image' \
4601 > -A ppc -O linux -T ramdisk -C gzip \
4602 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4603 Image Name: Simple Ramdisk Image
4604 Created: Wed Jan 12 14:01:50 2000
4605 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4606 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4607 Load Address: 0x00000000
4608 Entry Point: 0x00000000
4610 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4611 option performs the converse operation of the mkimage's second form (the "-d"
4612 option). Given an image built by mkimage, the dumpimage extracts a "data file"
4615 tools/dumpimage -i image -T type -p position data_file
4616 -i ==> extract from the 'image' a specific 'data_file'
4617 -T ==> set image type to 'type'
4618 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
4621 Installing a Linux Image:
4622 -------------------------
4624 To downloading a U-Boot image over the serial (console) interface,
4625 you must convert the image to S-Record format:
4627 objcopy -I binary -O srec examples/image examples/image.srec
4629 The 'objcopy' does not understand the information in the U-Boot
4630 image header, so the resulting S-Record file will be relative to
4631 address 0x00000000. To load it to a given address, you need to
4632 specify the target address as 'offset' parameter with the 'loads'
4635 Example: install the image to address 0x40100000 (which on the
4636 TQM8xxL is in the first Flash bank):
4638 => erase 40100000 401FFFFF
4644 ## Ready for S-Record download ...
4645 ~>examples/image.srec
4646 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4648 15989 15990 15991 15992
4649 [file transfer complete]
4651 ## Start Addr = 0x00000000
4654 You can check the success of the download using the 'iminfo' command;
4655 this includes a checksum verification so you can be sure no data
4656 corruption happened:
4660 ## Checking Image at 40100000 ...
4661 Image Name: 2.2.13 for initrd on TQM850L
4662 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4663 Data Size: 335725 Bytes = 327 kB = 0 MB
4664 Load Address: 00000000
4665 Entry Point: 0000000c
4666 Verifying Checksum ... OK
4672 The "bootm" command is used to boot an application that is stored in
4673 memory (RAM or Flash). In case of a Linux kernel image, the contents
4674 of the "bootargs" environment variable is passed to the kernel as
4675 parameters. You can check and modify this variable using the
4676 "printenv" and "setenv" commands:
4679 => printenv bootargs
4680 bootargs=root=/dev/ram
4682 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4684 => printenv bootargs
4685 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4688 ## Booting Linux kernel at 40020000 ...
4689 Image Name: 2.2.13 for NFS on TQM850L
4690 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4691 Data Size: 381681 Bytes = 372 kB = 0 MB
4692 Load Address: 00000000
4693 Entry Point: 0000000c
4694 Verifying Checksum ... OK
4695 Uncompressing Kernel Image ... OK
4696 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
4697 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4698 time_init: decrementer frequency = 187500000/60
4699 Calibrating delay loop... 49.77 BogoMIPS
4700 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4703 If you want to boot a Linux kernel with initial RAM disk, you pass
4704 the memory addresses of both the kernel and the initrd image (PPBCOOT
4705 format!) to the "bootm" command:
4707 => imi 40100000 40200000
4709 ## Checking Image at 40100000 ...
4710 Image Name: 2.2.13 for initrd on TQM850L
4711 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4712 Data Size: 335725 Bytes = 327 kB = 0 MB
4713 Load Address: 00000000
4714 Entry Point: 0000000c
4715 Verifying Checksum ... OK
4717 ## Checking Image at 40200000 ...
4718 Image Name: Simple Ramdisk Image
4719 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4720 Data Size: 566530 Bytes = 553 kB = 0 MB
4721 Load Address: 00000000
4722 Entry Point: 00000000
4723 Verifying Checksum ... OK
4725 => bootm 40100000 40200000
4726 ## Booting Linux kernel at 40100000 ...
4727 Image Name: 2.2.13 for initrd on TQM850L
4728 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4729 Data Size: 335725 Bytes = 327 kB = 0 MB
4730 Load Address: 00000000
4731 Entry Point: 0000000c
4732 Verifying Checksum ... OK
4733 Uncompressing Kernel Image ... OK
4734 ## Loading RAMDisk Image at 40200000 ...
4735 Image Name: Simple Ramdisk Image
4736 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4737 Data Size: 566530 Bytes = 553 kB = 0 MB
4738 Load Address: 00000000
4739 Entry Point: 00000000
4740 Verifying Checksum ... OK
4741 Loading Ramdisk ... OK
4742 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
4743 Boot arguments: root=/dev/ram
4744 time_init: decrementer frequency = 187500000/60
4745 Calibrating delay loop... 49.77 BogoMIPS
4747 RAMDISK: Compressed image found at block 0
4748 VFS: Mounted root (ext2 filesystem).
4752 Boot Linux and pass a flat device tree:
4755 First, U-Boot must be compiled with the appropriate defines. See the section
4756 titled "Linux Kernel Interface" above for a more in depth explanation. The
4757 following is an example of how to start a kernel and pass an updated
4763 oft=oftrees/mpc8540ads.dtb
4764 => tftp $oftaddr $oft
4765 Speed: 1000, full duplex
4767 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4768 Filename 'oftrees/mpc8540ads.dtb'.
4769 Load address: 0x300000
4772 Bytes transferred = 4106 (100a hex)
4773 => tftp $loadaddr $bootfile
4774 Speed: 1000, full duplex
4776 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4778 Load address: 0x200000
4779 Loading:############
4781 Bytes transferred = 1029407 (fb51f hex)
4786 => bootm $loadaddr - $oftaddr
4787 ## Booting image at 00200000 ...
4788 Image Name: Linux-2.6.17-dirty
4789 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4790 Data Size: 1029343 Bytes = 1005.2 kB
4791 Load Address: 00000000
4792 Entry Point: 00000000
4793 Verifying Checksum ... OK
4794 Uncompressing Kernel Image ... OK
4795 Booting using flat device tree at 0x300000
4796 Using MPC85xx ADS machine description
4797 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4801 More About U-Boot Image Types:
4802 ------------------------------
4804 U-Boot supports the following image types:
4806 "Standalone Programs" are directly runnable in the environment
4807 provided by U-Boot; it is expected that (if they behave
4808 well) you can continue to work in U-Boot after return from
4809 the Standalone Program.
4810 "OS Kernel Images" are usually images of some Embedded OS which
4811 will take over control completely. Usually these programs
4812 will install their own set of exception handlers, device
4813 drivers, set up the MMU, etc. - this means, that you cannot
4814 expect to re-enter U-Boot except by resetting the CPU.
4815 "RAMDisk Images" are more or less just data blocks, and their
4816 parameters (address, size) are passed to an OS kernel that is
4818 "Multi-File Images" contain several images, typically an OS
4819 (Linux) kernel image and one or more data images like
4820 RAMDisks. This construct is useful for instance when you want
4821 to boot over the network using BOOTP etc., where the boot
4822 server provides just a single image file, but you want to get
4823 for instance an OS kernel and a RAMDisk image.
4825 "Multi-File Images" start with a list of image sizes, each
4826 image size (in bytes) specified by an "uint32_t" in network
4827 byte order. This list is terminated by an "(uint32_t)0".
4828 Immediately after the terminating 0 follow the images, one by
4829 one, all aligned on "uint32_t" boundaries (size rounded up to
4830 a multiple of 4 bytes).
4832 "Firmware Images" are binary images containing firmware (like
4833 U-Boot or FPGA images) which usually will be programmed to
4836 "Script files" are command sequences that will be executed by
4837 U-Boot's command interpreter; this feature is especially
4838 useful when you configure U-Boot to use a real shell (hush)
4839 as command interpreter.
4841 Booting the Linux zImage:
4842 -------------------------
4844 On some platforms, it's possible to boot Linux zImage. This is done
4845 using the "bootz" command. The syntax of "bootz" command is the same
4846 as the syntax of "bootm" command.
4848 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
4849 kernel with raw initrd images. The syntax is slightly different, the
4850 address of the initrd must be augmented by it's size, in the following
4851 format: "<initrd addres>:<initrd size>".
4857 One of the features of U-Boot is that you can dynamically load and
4858 run "standalone" applications, which can use some resources of
4859 U-Boot like console I/O functions or interrupt services.
4861 Two simple examples are included with the sources:
4866 'examples/hello_world.c' contains a small "Hello World" Demo
4867 application; it is automatically compiled when you build U-Boot.
4868 It's configured to run at address 0x00040004, so you can play with it
4872 ## Ready for S-Record download ...
4873 ~>examples/hello_world.srec
4874 1 2 3 4 5 6 7 8 9 10 11 ...
4875 [file transfer complete]
4877 ## Start Addr = 0x00040004
4879 => go 40004 Hello World! This is a test.
4880 ## Starting application at 0x00040004 ...
4891 Hit any key to exit ...
4893 ## Application terminated, rc = 0x0
4895 Another example, which demonstrates how to register a CPM interrupt
4896 handler with the U-Boot code, can be found in 'examples/timer.c'.
4897 Here, a CPM timer is set up to generate an interrupt every second.
4898 The interrupt service routine is trivial, just printing a '.'
4899 character, but this is just a demo program. The application can be
4900 controlled by the following keys:
4902 ? - print current values og the CPM Timer registers
4903 b - enable interrupts and start timer
4904 e - stop timer and disable interrupts
4905 q - quit application
4908 ## Ready for S-Record download ...
4909 ~>examples/timer.srec
4910 1 2 3 4 5 6 7 8 9 10 11 ...
4911 [file transfer complete]
4913 ## Start Addr = 0x00040004
4916 ## Starting application at 0x00040004 ...
4919 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4922 [q, b, e, ?] Set interval 1000000 us
4925 [q, b, e, ?] ........
4926 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4929 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4932 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4935 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4937 [q, b, e, ?] ...Stopping timer
4939 [q, b, e, ?] ## Application terminated, rc = 0x0
4945 Over time, many people have reported problems when trying to use the
4946 "minicom" terminal emulation program for serial download. I (wd)
4947 consider minicom to be broken, and recommend not to use it. Under
4948 Unix, I recommend to use C-Kermit for general purpose use (and
4949 especially for kermit binary protocol download ("loadb" command), and
4950 use "cu" for S-Record download ("loads" command). See
4951 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4952 for help with kermit.
4955 Nevertheless, if you absolutely want to use it try adding this
4956 configuration to your "File transfer protocols" section:
4958 Name Program Name U/D FullScr IO-Red. Multi
4959 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4960 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4966 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4967 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4969 Building requires a cross environment; it is known to work on
4970 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4971 need gmake since the Makefiles are not compatible with BSD make).
4972 Note that the cross-powerpc package does not install include files;
4973 attempting to build U-Boot will fail because <machine/ansi.h> is
4974 missing. This file has to be installed and patched manually:
4976 # cd /usr/pkg/cross/powerpc-netbsd/include
4978 # ln -s powerpc machine
4979 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4980 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4982 Native builds *don't* work due to incompatibilities between native
4983 and U-Boot include files.
4985 Booting assumes that (the first part of) the image booted is a
4986 stage-2 loader which in turn loads and then invokes the kernel
4987 proper. Loader sources will eventually appear in the NetBSD source
4988 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4989 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4992 Implementation Internals:
4993 =========================
4995 The following is not intended to be a complete description of every
4996 implementation detail. However, it should help to understand the
4997 inner workings of U-Boot and make it easier to port it to custom
5001 Initial Stack, Global Data:
5002 ---------------------------
5004 The implementation of U-Boot is complicated by the fact that U-Boot
5005 starts running out of ROM (flash memory), usually without access to
5006 system RAM (because the memory controller is not initialized yet).
5007 This means that we don't have writable Data or BSS segments, and BSS
5008 is not initialized as zero. To be able to get a C environment working
5009 at all, we have to allocate at least a minimal stack. Implementation
5010 options for this are defined and restricted by the CPU used: Some CPU
5011 models provide on-chip memory (like the IMMR area on MPC8xx and
5012 MPC826x processors), on others (parts of) the data cache can be
5013 locked as (mis-) used as memory, etc.
5015 Chris Hallinan posted a good summary of these issues to the
5016 U-Boot mailing list:
5018 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5019 From: "Chris Hallinan" <clh@net1plus.com>
5020 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5023 Correct me if I'm wrong, folks, but the way I understand it
5024 is this: Using DCACHE as initial RAM for Stack, etc, does not
5025 require any physical RAM backing up the cache. The cleverness
5026 is that the cache is being used as a temporary supply of
5027 necessary storage before the SDRAM controller is setup. It's
5028 beyond the scope of this list to explain the details, but you
5029 can see how this works by studying the cache architecture and
5030 operation in the architecture and processor-specific manuals.
5032 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5033 is another option for the system designer to use as an
5034 initial stack/RAM area prior to SDRAM being available. Either
5035 option should work for you. Using CS 4 should be fine if your
5036 board designers haven't used it for something that would
5037 cause you grief during the initial boot! It is frequently not
5040 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5041 with your processor/board/system design. The default value
5042 you will find in any recent u-boot distribution in
5043 walnut.h should work for you. I'd set it to a value larger
5044 than your SDRAM module. If you have a 64MB SDRAM module, set
5045 it above 400_0000. Just make sure your board has no resources
5046 that are supposed to respond to that address! That code in
5047 start.S has been around a while and should work as is when
5048 you get the config right.
5053 It is essential to remember this, since it has some impact on the C
5054 code for the initialization procedures:
5056 * Initialized global data (data segment) is read-only. Do not attempt
5059 * Do not use any uninitialized global data (or implicitly initialized
5060 as zero data - BSS segment) at all - this is undefined, initiali-
5061 zation is performed later (when relocating to RAM).
5063 * Stack space is very limited. Avoid big data buffers or things like
5066 Having only the stack as writable memory limits means we cannot use
5067 normal global data to share information between the code. But it
5068 turned out that the implementation of U-Boot can be greatly
5069 simplified by making a global data structure (gd_t) available to all
5070 functions. We could pass a pointer to this data as argument to _all_
5071 functions, but this would bloat the code. Instead we use a feature of
5072 the GCC compiler (Global Register Variables) to share the data: we
5073 place a pointer (gd) to the global data into a register which we
5074 reserve for this purpose.
5076 When choosing a register for such a purpose we are restricted by the
5077 relevant (E)ABI specifications for the current architecture, and by
5078 GCC's implementation.
5080 For PowerPC, the following registers have specific use:
5082 R2: reserved for system use
5083 R3-R4: parameter passing and return values
5084 R5-R10: parameter passing
5085 R13: small data area pointer
5089 (U-Boot also uses R12 as internal GOT pointer. r12
5090 is a volatile register so r12 needs to be reset when
5091 going back and forth between asm and C)
5093 ==> U-Boot will use R2 to hold a pointer to the global data
5095 Note: on PPC, we could use a static initializer (since the
5096 address of the global data structure is known at compile time),
5097 but it turned out that reserving a register results in somewhat
5098 smaller code - although the code savings are not that big (on
5099 average for all boards 752 bytes for the whole U-Boot image,
5100 624 text + 127 data).
5102 On ARM, the following registers are used:
5104 R0: function argument word/integer result
5105 R1-R3: function argument word
5106 R9: platform specific
5107 R10: stack limit (used only if stack checking is enabled)
5108 R11: argument (frame) pointer
5109 R12: temporary workspace
5112 R15: program counter
5114 ==> U-Boot will use R9 to hold a pointer to the global data
5116 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5118 On Nios II, the ABI is documented here:
5119 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5121 ==> U-Boot will use gp to hold a pointer to the global data
5123 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5124 to access small data sections, so gp is free.
5126 On NDS32, the following registers are used:
5128 R0-R1: argument/return
5130 R15: temporary register for assembler
5131 R16: trampoline register
5132 R28: frame pointer (FP)
5133 R29: global pointer (GP)
5134 R30: link register (LP)
5135 R31: stack pointer (SP)
5136 PC: program counter (PC)
5138 ==> U-Boot will use R10 to hold a pointer to the global data
5140 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5141 or current versions of GCC may "optimize" the code too much.
5146 U-Boot runs in system state and uses physical addresses, i.e. the
5147 MMU is not used either for address mapping nor for memory protection.
5149 The available memory is mapped to fixed addresses using the memory
5150 controller. In this process, a contiguous block is formed for each
5151 memory type (Flash, SDRAM, SRAM), even when it consists of several
5152 physical memory banks.
5154 U-Boot is installed in the first 128 kB of the first Flash bank (on
5155 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5156 booting and sizing and initializing DRAM, the code relocates itself
5157 to the upper end of DRAM. Immediately below the U-Boot code some
5158 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5159 configuration setting]. Below that, a structure with global Board
5160 Info data is placed, followed by the stack (growing downward).
5162 Additionally, some exception handler code is copied to the low 8 kB
5163 of DRAM (0x00000000 ... 0x00001FFF).
5165 So a typical memory configuration with 16 MB of DRAM could look like
5168 0x0000 0000 Exception Vector code
5171 0x0000 2000 Free for Application Use
5177 0x00FB FF20 Monitor Stack (Growing downward)
5178 0x00FB FFAC Board Info Data and permanent copy of global data
5179 0x00FC 0000 Malloc Arena
5182 0x00FE 0000 RAM Copy of Monitor Code
5183 ... eventually: LCD or video framebuffer
5184 ... eventually: pRAM (Protected RAM - unchanged by reset)
5185 0x00FF FFFF [End of RAM]
5188 System Initialization:
5189 ----------------------
5191 In the reset configuration, U-Boot starts at the reset entry point
5192 (on most PowerPC systems at address 0x00000100). Because of the reset
5193 configuration for CS0# this is a mirror of the on board Flash memory.
5194 To be able to re-map memory U-Boot then jumps to its link address.
5195 To be able to implement the initialization code in C, a (small!)
5196 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5197 which provide such a feature like), or in a locked part of the data
5198 cache. After that, U-Boot initializes the CPU core, the caches and
5201 Next, all (potentially) available memory banks are mapped using a
5202 preliminary mapping. For example, we put them on 512 MB boundaries
5203 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5204 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5205 programmed for SDRAM access. Using the temporary configuration, a
5206 simple memory test is run that determines the size of the SDRAM
5209 When there is more than one SDRAM bank, and the banks are of
5210 different size, the largest is mapped first. For equal size, the first
5211 bank (CS2#) is mapped first. The first mapping is always for address
5212 0x00000000, with any additional banks following immediately to create
5213 contiguous memory starting from 0.
5215 Then, the monitor installs itself at the upper end of the SDRAM area
5216 and allocates memory for use by malloc() and for the global Board
5217 Info data; also, the exception vector code is copied to the low RAM
5218 pages, and the final stack is set up.
5220 Only after this relocation will you have a "normal" C environment;
5221 until that you are restricted in several ways, mostly because you are
5222 running from ROM, and because the code will have to be relocated to a
5226 U-Boot Porting Guide:
5227 ----------------------
5229 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5233 int main(int argc, char *argv[])
5235 sighandler_t no_more_time;
5237 signal(SIGALRM, no_more_time);
5238 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5240 if (available_money > available_manpower) {
5241 Pay consultant to port U-Boot;
5245 Download latest U-Boot source;
5247 Subscribe to u-boot mailing list;
5250 email("Hi, I am new to U-Boot, how do I get started?");
5253 Read the README file in the top level directory;
5254 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5255 Read applicable doc/*.README;
5256 Read the source, Luke;
5257 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5260 if (available_money > toLocalCurrency ($2500))
5263 Add a lot of aggravation and time;
5265 if (a similar board exists) { /* hopefully... */
5266 cp -a board/<similar> board/<myboard>
5267 cp include/configs/<similar>.h include/configs/<myboard>.h
5269 Create your own board support subdirectory;
5270 Create your own board include/configs/<myboard>.h file;
5272 Edit new board/<myboard> files
5273 Edit new include/configs/<myboard>.h
5278 Add / modify source code;
5282 email("Hi, I am having problems...");
5284 Send patch file to the U-Boot email list;
5285 if (reasonable critiques)
5286 Incorporate improvements from email list code review;
5288 Defend code as written;
5294 void no_more_time (int sig)
5303 All contributions to U-Boot should conform to the Linux kernel
5304 coding style; see the file "Documentation/CodingStyle" and the script
5305 "scripts/Lindent" in your Linux kernel source directory.
5307 Source files originating from a different project (for example the
5308 MTD subsystem) are generally exempt from these guidelines and are not
5309 reformatted to ease subsequent migration to newer versions of those
5312 Please note that U-Boot is implemented in C (and to some small parts in
5313 Assembler); no C++ is used, so please do not use C++ style comments (//)
5316 Please also stick to the following formatting rules:
5317 - remove any trailing white space
5318 - use TAB characters for indentation and vertical alignment, not spaces
5319 - make sure NOT to use DOS '\r\n' line feeds
5320 - do not add more than 2 consecutive empty lines to source files
5321 - do not add trailing empty lines to source files
5323 Submissions which do not conform to the standards may be returned
5324 with a request to reformat the changes.
5330 Since the number of patches for U-Boot is growing, we need to
5331 establish some rules. Submissions which do not conform to these rules
5332 may be rejected, even when they contain important and valuable stuff.
5334 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5336 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5337 see http://lists.denx.de/mailman/listinfo/u-boot
5339 When you send a patch, please include the following information with
5342 * For bug fixes: a description of the bug and how your patch fixes
5343 this bug. Please try to include a way of demonstrating that the
5344 patch actually fixes something.
5346 * For new features: a description of the feature and your
5349 * A CHANGELOG entry as plaintext (separate from the patch)
5351 * For major contributions, add a MAINTAINERS file with your
5352 information and associated file and directory references.
5354 * When you add support for a new board, don't forget to add a
5355 maintainer e-mail address to the boards.cfg file, too.
5357 * If your patch adds new configuration options, don't forget to
5358 document these in the README file.
5360 * The patch itself. If you are using git (which is *strongly*
5361 recommended) you can easily generate the patch using the
5362 "git format-patch". If you then use "git send-email" to send it to
5363 the U-Boot mailing list, you will avoid most of the common problems
5364 with some other mail clients.
5366 If you cannot use git, use "diff -purN OLD NEW". If your version of
5367 diff does not support these options, then get the latest version of
5370 The current directory when running this command shall be the parent
5371 directory of the U-Boot source tree (i. e. please make sure that
5372 your patch includes sufficient directory information for the
5375 We prefer patches as plain text. MIME attachments are discouraged,
5376 and compressed attachments must not be used.
5378 * If one logical set of modifications affects or creates several
5379 files, all these changes shall be submitted in a SINGLE patch file.
5381 * Changesets that contain different, unrelated modifications shall be
5382 submitted as SEPARATE patches, one patch per changeset.
5387 * Before sending the patch, run the buildman script on your patched
5388 source tree and make sure that no errors or warnings are reported
5389 for any of the boards.
5391 * Keep your modifications to the necessary minimum: A patch
5392 containing several unrelated changes or arbitrary reformats will be
5393 returned with a request to re-formatting / split it.
5395 * If you modify existing code, make sure that your new code does not
5396 add to the memory footprint of the code ;-) Small is beautiful!
5397 When adding new features, these should compile conditionally only
5398 (using #ifdef), and the resulting code with the new feature
5399 disabled must not need more memory than the old code without your
5402 * Remember that there is a size limit of 100 kB per message on the
5403 u-boot mailing list. Bigger patches will be moderated. If they are
5404 reasonable and not too big, they will be acknowledged. But patches
5405 bigger than the size limit should be avoided.