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 and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_798870
705 CONFIG_ARM_ERRATA_801819
708 CONFIG_TEGRA_SUPPORT_NON_SECURE
710 Support executing U-Boot in non-secure (NS) mode. Certain
711 impossible actions will be skipped if the CPU is in NS mode,
712 such as ARM architectural timer initialization.
715 Driver model is a new framework for devices in U-Boot
716 introduced in early 2014. U-Boot is being progressively
717 moved over to this. It offers a consistent device structure,
718 supports grouping devices into classes and has built-in
719 handling of platform data and device tree.
721 To enable transition to driver model in a relatively
722 painful fashion, each subsystem can be independently
723 switched between the legacy/ad-hoc approach and the new
724 driver model using the options below. Also, many uclass
725 interfaces include compatibility features which may be
726 removed once the conversion of that subsystem is complete.
727 As a result, the API provided by the subsystem may in fact
728 not change with driver model.
730 See doc/driver-model/README.txt for more information.
734 Enable driver model. This brings in the core support,
735 including scanning of platform data on start-up. If
736 CONFIG_OF_CONTROL is enabled, the device tree will be
737 scanned also when available.
741 Enable driver model test commands. These allow you to print
742 out the driver model tree and the uclasses.
746 Enable some demo devices and the 'demo' command. These are
747 really only useful for playing around while trying to
748 understand driver model in sandbox.
752 Enable driver model in SPL. You will need to provide a
753 suitable malloc() implementation. If you are not using the
754 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
755 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
756 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
757 In most cases driver model will only allocate a few uclasses
758 and devices in SPL, so 1KB should be enable. See
759 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
764 Enable driver model for serial. This replaces
765 drivers/serial/serial.c with the serial uclass, which
766 implements serial_putc() etc. The uclass interface is
767 defined in include/serial.h.
771 Enable driver model for GPIO access. The standard GPIO
772 interface (gpio_get_value(), etc.) is then implemented by
773 the GPIO uclass. Drivers provide methods to query the
774 particular GPIOs that they provide. The uclass interface
775 is defined in include/asm-generic/gpio.h.
779 Enable driver model for SPI. The SPI slave interface
780 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
781 the SPI uclass. Drivers provide methods to access the SPI
782 buses that they control. The uclass interface is defined in
783 include/spi.h. The existing spi_slave structure is attached
784 as 'parent data' to every slave on each bus. Slaves
785 typically use driver-private data instead of extending the
790 Enable driver model for SPI flash. This SPI flash interface
791 (spi_flash_probe(), spi_flash_write(), etc.) is then
792 implemented by the SPI flash uclass. There is one standard
793 SPI flash driver which knows how to probe most chips
794 supported by U-Boot. The uclass interface is defined in
795 include/spi_flash.h, but is currently fully compatible
796 with the old interface to avoid confusion and duplication
797 during the transition parent. SPI and SPI flash must be
798 enabled together (it is not possible to use driver model
799 for one and not the other).
803 Enable driver model for the Chrome OS EC interface. This
804 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
805 but otherwise makes few changes. Since cros_ec also supports
806 I2C and LPC (which don't support driver model yet), a full
807 conversion is not yet possible.
810 ** Code size options: The following options are enabled by
811 default except in SPL. Enable them explicitly to get these
816 Enable the dm_warn() function. This can use up quite a bit
817 of space for its strings.
821 Enable registering a serial device with the stdio library.
823 CONFIG_DM_DEVICE_REMOVE
825 Enable removing of devices.
827 - Linux Kernel Interface:
830 U-Boot stores all clock information in Hz
831 internally. For binary compatibility with older Linux
832 kernels (which expect the clocks passed in the
833 bd_info data to be in MHz) the environment variable
834 "clocks_in_mhz" can be defined so that U-Boot
835 converts clock data to MHZ before passing it to the
837 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
838 "clocks_in_mhz=1" is automatically included in the
841 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
843 When transferring memsize parameter to Linux, some versions
844 expect it to be in bytes, others in MB.
845 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
849 New kernel versions are expecting firmware settings to be
850 passed using flattened device trees (based on open firmware
854 * New libfdt-based support
855 * Adds the "fdt" command
856 * The bootm command automatically updates the fdt
858 OF_CPU - The proper name of the cpus node (only required for
859 MPC512X and MPC5xxx based boards).
860 OF_SOC - The proper name of the soc node (only required for
861 MPC512X and MPC5xxx based boards).
862 OF_TBCLK - The timebase frequency.
863 OF_STDOUT_PATH - The path to the console device
865 boards with QUICC Engines require OF_QE to set UCC MAC
868 CONFIG_OF_BOARD_SETUP
870 Board code has addition modification that it wants to make
871 to the flat device tree before handing it off to the kernel
873 CONFIG_OF_SYSTEM_SETUP
875 Other code has addition modification that it wants to make
876 to the flat device tree before handing it off to the kernel.
877 This causes ft_system_setup() to be called before booting
882 This define fills in the correct boot CPU in the boot
883 param header, the default value is zero if undefined.
887 U-Boot can detect if an IDE device is present or not.
888 If not, and this new config option is activated, U-Boot
889 removes the ATA node from the DTS before booting Linux,
890 so the Linux IDE driver does not probe the device and
891 crash. This is needed for buggy hardware (uc101) where
892 no pull down resistor is connected to the signal IDE5V_DD7.
894 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
896 This setting is mandatory for all boards that have only one
897 machine type and must be used to specify the machine type
898 number as it appears in the ARM machine registry
899 (see http://www.arm.linux.org.uk/developer/machines/).
900 Only boards that have multiple machine types supported
901 in a single configuration file and the machine type is
902 runtime discoverable, do not have to use this setting.
904 - vxWorks boot parameters:
906 bootvx constructs a valid bootline using the following
907 environments variables: bootfile, ipaddr, serverip, hostname.
908 It loads the vxWorks image pointed bootfile.
910 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
911 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
912 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
913 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
915 CONFIG_SYS_VXWORKS_ADD_PARAMS
917 Add it at the end of the bootline. E.g "u=username pw=secret"
919 Note: If a "bootargs" environment is defined, it will overwride
920 the defaults discussed just above.
922 - Cache Configuration:
923 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
924 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
925 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
927 - Cache Configuration for ARM:
928 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
930 CONFIG_SYS_PL310_BASE - Physical base address of PL310
931 controller register space
936 Define this if you want support for Amba PrimeCell PL010 UARTs.
940 Define this if you want support for Amba PrimeCell PL011 UARTs.
944 If you have Amba PrimeCell PL011 UARTs, set this variable to
945 the clock speed of the UARTs.
949 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
950 define this to a list of base addresses for each (supported)
951 port. See e.g. include/configs/versatile.h
953 CONFIG_PL011_SERIAL_RLCR
955 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
956 have separate receive and transmit line control registers. Set
957 this variable to initialize the extra register.
959 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
961 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
962 boot loader that has already initialized the UART. Define this
963 variable to flush the UART at init time.
965 CONFIG_SERIAL_HW_FLOW_CONTROL
967 Define this variable to enable hw flow control in serial driver.
968 Current user of this option is drivers/serial/nsl16550.c driver
971 Depending on board, define exactly one serial port
972 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
973 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
974 console by defining CONFIG_8xx_CONS_NONE
976 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
977 port routines must be defined elsewhere
978 (i.e. serial_init(), serial_getc(), ...)
981 Enables console device for a color framebuffer. Needs following
982 defines (cf. smiLynxEM, i8042)
983 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
985 VIDEO_HW_RECTFILL graphic chip supports
988 VIDEO_HW_BITBLT graphic chip supports
989 bit-blit (cf. smiLynxEM)
990 VIDEO_VISIBLE_COLS visible pixel columns
992 VIDEO_VISIBLE_ROWS visible pixel rows
993 VIDEO_PIXEL_SIZE bytes per pixel
994 VIDEO_DATA_FORMAT graphic data format
995 (0-5, cf. cfb_console.c)
996 VIDEO_FB_ADRS framebuffer address
997 VIDEO_KBD_INIT_FCT keyboard int fct
998 (i.e. i8042_kbd_init())
999 VIDEO_TSTC_FCT test char fct
1001 VIDEO_GETC_FCT get char fct
1003 CONFIG_CONSOLE_CURSOR cursor drawing on/off
1004 (requires blink timer
1006 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1007 CONFIG_CONSOLE_TIME display time/date info in
1009 (requires CONFIG_CMD_DATE)
1010 CONFIG_VIDEO_LOGO display Linux logo in
1012 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1013 linux_logo.h for logo.
1014 Requires CONFIG_VIDEO_LOGO
1015 CONFIG_CONSOLE_EXTRA_INFO
1016 additional board info beside
1019 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1020 a limited number of ANSI escape sequences (cursor control,
1021 erase functions and limited graphics rendition control).
1023 When CONFIG_CFB_CONSOLE is defined, video console is
1024 default i/o. Serial console can be forced with
1025 environment 'console=serial'.
1027 When CONFIG_SILENT_CONSOLE is defined, all console
1028 messages (by U-Boot and Linux!) can be silenced with
1029 the "silent" environment variable. See
1030 doc/README.silent for more information.
1032 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1034 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1038 CONFIG_BAUDRATE - in bps
1039 Select one of the baudrates listed in
1040 CONFIG_SYS_BAUDRATE_TABLE, see below.
1041 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1043 - Console Rx buffer length
1044 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1045 the maximum receive buffer length for the SMC.
1046 This option is actual only for 82xx and 8xx possible.
1047 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1048 must be defined, to setup the maximum idle timeout for
1051 - Pre-Console Buffer:
1052 Prior to the console being initialised (i.e. serial UART
1053 initialised etc) all console output is silently discarded.
1054 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1055 buffer any console messages prior to the console being
1056 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1057 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1058 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1059 bytes are output before the console is initialised, the
1060 earlier bytes are discarded.
1062 Note that when printing the buffer a copy is made on the
1063 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
1065 'Sane' compilers will generate smaller code if
1066 CONFIG_PRE_CON_BUF_SZ is a power of 2
1068 - Safe printf() functions
1069 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1070 the printf() functions. These are defined in
1071 include/vsprintf.h and include snprintf(), vsnprintf() and
1072 so on. Code size increase is approximately 300-500 bytes.
1073 If this option is not given then these functions will
1074 silently discard their buffer size argument - this means
1075 you are not getting any overflow checking in this case.
1077 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1078 Delay before automatically booting the default image;
1079 set to -1 to disable autoboot.
1080 set to -2 to autoboot with no delay and not check for abort
1081 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1083 See doc/README.autoboot for these options that
1084 work with CONFIG_BOOTDELAY. None are required.
1085 CONFIG_BOOT_RETRY_TIME
1086 CONFIG_BOOT_RETRY_MIN
1087 CONFIG_AUTOBOOT_KEYED
1088 CONFIG_AUTOBOOT_PROMPT
1089 CONFIG_AUTOBOOT_DELAY_STR
1090 CONFIG_AUTOBOOT_STOP_STR
1091 CONFIG_ZERO_BOOTDELAY_CHECK
1092 CONFIG_RESET_TO_RETRY
1096 Only needed when CONFIG_BOOTDELAY is enabled;
1097 define a command string that is automatically executed
1098 when no character is read on the console interface
1099 within "Boot Delay" after reset.
1102 This can be used to pass arguments to the bootm
1103 command. The value of CONFIG_BOOTARGS goes into the
1104 environment value "bootargs".
1106 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1107 The value of these goes into the environment as
1108 "ramboot" and "nfsboot" respectively, and can be used
1109 as a convenience, when switching between booting from
1113 CONFIG_BOOTCOUNT_LIMIT
1114 Implements a mechanism for detecting a repeating reboot
1116 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1118 CONFIG_BOOTCOUNT_ENV
1119 If no softreset save registers are found on the hardware
1120 "bootcount" is stored in the environment. To prevent a
1121 saveenv on all reboots, the environment variable
1122 "upgrade_available" is used. If "upgrade_available" is
1123 0, "bootcount" is always 0, if "upgrade_available" is
1124 1 "bootcount" is incremented in the environment.
1125 So the Userspace Applikation must set the "upgrade_available"
1126 and "bootcount" variable to 0, if a boot was successfully.
1128 - Pre-Boot Commands:
1131 When this option is #defined, the existence of the
1132 environment variable "preboot" will be checked
1133 immediately before starting the CONFIG_BOOTDELAY
1134 countdown and/or running the auto-boot command resp.
1135 entering interactive mode.
1137 This feature is especially useful when "preboot" is
1138 automatically generated or modified. For an example
1139 see the LWMON board specific code: here "preboot" is
1140 modified when the user holds down a certain
1141 combination of keys on the (special) keyboard when
1144 - Serial Download Echo Mode:
1146 If defined to 1, all characters received during a
1147 serial download (using the "loads" command) are
1148 echoed back. This might be needed by some terminal
1149 emulations (like "cu"), but may as well just take
1150 time on others. This setting #define's the initial
1151 value of the "loads_echo" environment variable.
1153 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1154 CONFIG_KGDB_BAUDRATE
1155 Select one of the baudrates listed in
1156 CONFIG_SYS_BAUDRATE_TABLE, see below.
1158 - Monitor Functions:
1159 Monitor commands can be included or excluded
1160 from the build by using the #include files
1161 <config_cmd_all.h> and #undef'ing unwanted
1162 commands, or adding #define's for wanted commands.
1164 The default command configuration includes all commands
1165 except those marked below with a "*".
1167 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1168 CONFIG_CMD_ASKENV * ask for env variable
1169 CONFIG_CMD_BDI bdinfo
1170 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1171 CONFIG_CMD_BMP * BMP support
1172 CONFIG_CMD_BSP * Board specific commands
1173 CONFIG_CMD_BOOTD bootd
1174 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1175 CONFIG_CMD_CACHE * icache, dcache
1176 CONFIG_CMD_CLK * clock command support
1177 CONFIG_CMD_CONSOLE coninfo
1178 CONFIG_CMD_CRC32 * crc32
1179 CONFIG_CMD_DATE * support for RTC, date/time...
1180 CONFIG_CMD_DHCP * DHCP support
1181 CONFIG_CMD_DIAG * Diagnostics
1182 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1183 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1184 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1185 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1186 CONFIG_CMD_DTT * Digital Therm and Thermostat
1187 CONFIG_CMD_ECHO echo arguments
1188 CONFIG_CMD_EDITENV edit env variable
1189 CONFIG_CMD_EEPROM * EEPROM read/write support
1190 CONFIG_CMD_ELF * bootelf, bootvx
1191 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1192 CONFIG_CMD_ENV_FLAGS * display details about env flags
1193 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1194 CONFIG_CMD_EXPORTENV * export the environment
1195 CONFIG_CMD_EXT2 * ext2 command support
1196 CONFIG_CMD_EXT4 * ext4 command support
1197 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1198 that work for multiple fs types
1199 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1200 CONFIG_CMD_SAVEENV saveenv
1201 CONFIG_CMD_FDC * Floppy Disk Support
1202 CONFIG_CMD_FAT * FAT command support
1203 CONFIG_CMD_FLASH flinfo, erase, protect
1204 CONFIG_CMD_FPGA FPGA device initialization support
1205 CONFIG_CMD_FUSE * Device fuse support
1206 CONFIG_CMD_GETTIME * Get time since boot
1207 CONFIG_CMD_GO * the 'go' command (exec code)
1208 CONFIG_CMD_GREPENV * search environment
1209 CONFIG_CMD_HASH * calculate hash / digest
1210 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1211 CONFIG_CMD_I2C * I2C serial bus support
1212 CONFIG_CMD_IDE * IDE harddisk support
1213 CONFIG_CMD_IMI iminfo
1214 CONFIG_CMD_IMLS List all images found in NOR flash
1215 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1216 CONFIG_CMD_IMMAP * IMMR dump support
1217 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1218 CONFIG_CMD_IMPORTENV * import an environment
1219 CONFIG_CMD_INI * import data from an ini file into the env
1220 CONFIG_CMD_IRQ * irqinfo
1221 CONFIG_CMD_ITEST Integer/string test of 2 values
1222 CONFIG_CMD_JFFS2 * JFFS2 Support
1223 CONFIG_CMD_KGDB * kgdb
1224 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1225 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1227 CONFIG_CMD_LOADB loadb
1228 CONFIG_CMD_LOADS loads
1229 CONFIG_CMD_MD5SUM * print md5 message digest
1230 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1231 CONFIG_CMD_MEMINFO * Display detailed memory information
1232 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1234 CONFIG_CMD_MEMTEST * mtest
1235 CONFIG_CMD_MISC Misc functions like sleep etc
1236 CONFIG_CMD_MMC * MMC memory mapped support
1237 CONFIG_CMD_MII * MII utility commands
1238 CONFIG_CMD_MTDPARTS * MTD partition support
1239 CONFIG_CMD_NAND * NAND support
1240 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1241 CONFIG_CMD_NFS NFS support
1242 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1243 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1244 CONFIG_CMD_PCI * pciinfo
1245 CONFIG_CMD_PCMCIA * PCMCIA support
1246 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1248 CONFIG_CMD_PORTIO * Port I/O
1249 CONFIG_CMD_READ * Read raw data from partition
1250 CONFIG_CMD_REGINFO * Register dump
1251 CONFIG_CMD_RUN run command in env variable
1252 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1253 CONFIG_CMD_SAVES * save S record dump
1254 CONFIG_CMD_SCSI * SCSI Support
1255 CONFIG_CMD_SDRAM * print SDRAM configuration information
1256 (requires CONFIG_CMD_I2C)
1257 CONFIG_CMD_SETGETDCR Support for DCR Register access
1259 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1260 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1261 (requires CONFIG_CMD_MEMORY)
1262 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1263 CONFIG_CMD_SOURCE "source" command Support
1264 CONFIG_CMD_SPI * SPI serial bus support
1265 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1266 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1267 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1268 CONFIG_CMD_TIMER * access to the system tick timer
1269 CONFIG_CMD_USB * USB support
1270 CONFIG_CMD_CDP * Cisco Discover Protocol support
1271 CONFIG_CMD_MFSL * Microblaze FSL support
1272 CONFIG_CMD_XIMG Load part of Multi Image
1273 CONFIG_CMD_UUID * Generate random UUID or GUID string
1275 EXAMPLE: If you want all functions except of network
1276 support you can write:
1278 #include "config_cmd_all.h"
1279 #undef CONFIG_CMD_NET
1282 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1284 Note: Don't enable the "icache" and "dcache" commands
1285 (configuration option CONFIG_CMD_CACHE) unless you know
1286 what you (and your U-Boot users) are doing. Data
1287 cache cannot be enabled on systems like the 8xx or
1288 8260 (where accesses to the IMMR region must be
1289 uncached), and it cannot be disabled on all other
1290 systems where we (mis-) use the data cache to hold an
1291 initial stack and some data.
1294 XXX - this list needs to get updated!
1296 - Regular expression support:
1298 If this variable is defined, U-Boot is linked against
1299 the SLRE (Super Light Regular Expression) library,
1300 which adds regex support to some commands, as for
1301 example "env grep" and "setexpr".
1305 If this variable is defined, U-Boot will use a device tree
1306 to configure its devices, instead of relying on statically
1307 compiled #defines in the board file. This option is
1308 experimental and only available on a few boards. The device
1309 tree is available in the global data as gd->fdt_blob.
1311 U-Boot needs to get its device tree from somewhere. This can
1312 be done using one of the two options below:
1315 If this variable is defined, U-Boot will embed a device tree
1316 binary in its image. This device tree file should be in the
1317 board directory and called <soc>-<board>.dts. The binary file
1318 is then picked up in board_init_f() and made available through
1319 the global data structure as gd->blob.
1322 If this variable is defined, U-Boot will build a device tree
1323 binary. It will be called u-boot.dtb. Architecture-specific
1324 code will locate it at run-time. Generally this works by:
1326 cat u-boot.bin u-boot.dtb >image.bin
1328 and in fact, U-Boot does this for you, creating a file called
1329 u-boot-dtb.bin which is useful in the common case. You can
1330 still use the individual files if you need something more
1335 If this variable is defined, it enables watchdog
1336 support for the SoC. There must be support in the SoC
1337 specific code for a watchdog. For the 8xx and 8260
1338 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1339 register. When supported for a specific SoC is
1340 available, then no further board specific code should
1341 be needed to use it.
1344 When using a watchdog circuitry external to the used
1345 SoC, then define this variable and provide board
1346 specific code for the "hw_watchdog_reset" function.
1348 CONFIG_AT91_HW_WDT_TIMEOUT
1349 specify the timeout in seconds. default 2 seconds.
1352 CONFIG_VERSION_VARIABLE
1353 If this variable is defined, an environment variable
1354 named "ver" is created by U-Boot showing the U-Boot
1355 version as printed by the "version" command.
1356 Any change to this variable will be reverted at the
1361 When CONFIG_CMD_DATE is selected, the type of the RTC
1362 has to be selected, too. Define exactly one of the
1365 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1366 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1367 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1368 CONFIG_RTC_MC146818 - use MC146818 RTC
1369 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1370 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1371 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1372 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1373 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1374 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1375 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1376 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1377 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1380 Note that if the RTC uses I2C, then the I2C interface
1381 must also be configured. See I2C Support, below.
1384 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1386 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1387 chip-ngpio pairs that tell the PCA953X driver the number of
1388 pins supported by a particular chip.
1390 Note that if the GPIO device uses I2C, then the I2C interface
1391 must also be configured. See I2C Support, below.
1394 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1395 accesses and can checksum them or write a list of them out
1396 to memory. See the 'iotrace' command for details. This is
1397 useful for testing device drivers since it can confirm that
1398 the driver behaves the same way before and after a code
1399 change. Currently this is supported on sandbox and arm. To
1400 add support for your architecture, add '#include <iotrace.h>'
1401 to the bottom of arch/<arch>/include/asm/io.h and test.
1403 Example output from the 'iotrace stats' command is below.
1404 Note that if the trace buffer is exhausted, the checksum will
1405 still continue to operate.
1408 Start: 10000000 (buffer start address)
1409 Size: 00010000 (buffer size)
1410 Offset: 00000120 (current buffer offset)
1411 Output: 10000120 (start + offset)
1412 Count: 00000018 (number of trace records)
1413 CRC32: 9526fb66 (CRC32 of all trace records)
1415 - Timestamp Support:
1417 When CONFIG_TIMESTAMP is selected, the timestamp
1418 (date and time) of an image is printed by image
1419 commands like bootm or iminfo. This option is
1420 automatically enabled when you select CONFIG_CMD_DATE .
1422 - Partition Labels (disklabels) Supported:
1423 Zero or more of the following:
1424 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1425 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1426 Intel architecture, USB sticks, etc.
1427 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1428 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1429 bootloader. Note 2TB partition limit; see
1431 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1433 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1434 CONFIG_CMD_SCSI) you must configure support for at
1435 least one non-MTD partition type as well.
1438 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1439 board configurations files but used nowhere!
1441 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1442 be performed by calling the function
1443 ide_set_reset(int reset)
1444 which has to be defined in a board specific file
1449 Set this to enable ATAPI support.
1454 Set this to enable support for disks larger than 137GB
1455 Also look at CONFIG_SYS_64BIT_LBA.
1456 Whithout these , LBA48 support uses 32bit variables and will 'only'
1457 support disks up to 2.1TB.
1459 CONFIG_SYS_64BIT_LBA:
1460 When enabled, makes the IDE subsystem use 64bit sector addresses.
1464 At the moment only there is only support for the
1465 SYM53C8XX SCSI controller; define
1466 CONFIG_SCSI_SYM53C8XX to enable it.
1468 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1469 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1470 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1471 maximum numbers of LUNs, SCSI ID's and target
1473 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1475 The environment variable 'scsidevs' is set to the number of
1476 SCSI devices found during the last scan.
1478 - NETWORK Support (PCI):
1480 Support for Intel 8254x/8257x gigabit chips.
1483 Utility code for direct access to the SPI bus on Intel 8257x.
1484 This does not do anything useful unless you set at least one
1485 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1487 CONFIG_E1000_SPI_GENERIC
1488 Allow generic access to the SPI bus on the Intel 8257x, for
1489 example with the "sspi" command.
1492 Management command for E1000 devices. When used on devices
1493 with SPI support you can reprogram the EEPROM from U-Boot.
1496 Support for Intel 82557/82559/82559ER chips.
1497 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1498 write routine for first time initialisation.
1501 Support for Digital 2114x chips.
1502 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1503 modem chip initialisation (KS8761/QS6611).
1506 Support for National dp83815 chips.
1509 Support for National dp8382[01] gigabit chips.
1511 - NETWORK Support (other):
1513 CONFIG_DRIVER_AT91EMAC
1514 Support for AT91RM9200 EMAC.
1517 Define this to use reduced MII inteface
1519 CONFIG_DRIVER_AT91EMAC_QUIET
1520 If this defined, the driver is quiet.
1521 The driver doen't show link status messages.
1523 CONFIG_CALXEDA_XGMAC
1524 Support for the Calxeda XGMAC device
1527 Support for SMSC's LAN91C96 chips.
1529 CONFIG_LAN91C96_BASE
1530 Define this to hold the physical address
1531 of the LAN91C96's I/O space
1533 CONFIG_LAN91C96_USE_32_BIT
1534 Define this to enable 32 bit addressing
1537 Support for SMSC's LAN91C111 chip
1539 CONFIG_SMC91111_BASE
1540 Define this to hold the physical address
1541 of the device (I/O space)
1543 CONFIG_SMC_USE_32_BIT
1544 Define this if data bus is 32 bits
1546 CONFIG_SMC_USE_IOFUNCS
1547 Define this to use i/o functions instead of macros
1548 (some hardware wont work with macros)
1550 CONFIG_DRIVER_TI_EMAC
1551 Support for davinci emac
1553 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1554 Define this if you have more then 3 PHYs.
1557 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1559 CONFIG_FTGMAC100_EGIGA
1560 Define this to use GE link update with gigabit PHY.
1561 Define this if FTGMAC100 is connected to gigabit PHY.
1562 If your system has 10/100 PHY only, it might not occur
1563 wrong behavior. Because PHY usually return timeout or
1564 useless data when polling gigabit status and gigabit
1565 control registers. This behavior won't affect the
1566 correctnessof 10/100 link speed update.
1569 Support for SMSC's LAN911x and LAN921x chips
1572 Define this to hold the physical address
1573 of the device (I/O space)
1575 CONFIG_SMC911X_32_BIT
1576 Define this if data bus is 32 bits
1578 CONFIG_SMC911X_16_BIT
1579 Define this if data bus is 16 bits. If your processor
1580 automatically converts one 32 bit word to two 16 bit
1581 words you may also try CONFIG_SMC911X_32_BIT.
1584 Support for Renesas on-chip Ethernet controller
1586 CONFIG_SH_ETHER_USE_PORT
1587 Define the number of ports to be used
1589 CONFIG_SH_ETHER_PHY_ADDR
1590 Define the ETH PHY's address
1592 CONFIG_SH_ETHER_CACHE_WRITEBACK
1593 If this option is set, the driver enables cache flush.
1597 Support for PWM modul on the imx6.
1601 Support TPM devices.
1604 Support for i2c bus TPM devices. Only one device
1605 per system is supported at this time.
1607 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1608 Define the burst count bytes upper limit
1610 CONFIG_TPM_ATMEL_TWI
1611 Support for Atmel TWI TPM device. Requires I2C support.
1614 Support for generic parallel port TPM devices. Only one device
1615 per system is supported at this time.
1617 CONFIG_TPM_TIS_BASE_ADDRESS
1618 Base address where the generic TPM device is mapped
1619 to. Contemporary x86 systems usually map it at
1623 Add tpm monitor functions.
1624 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1625 provides monitor access to authorized functions.
1628 Define this to enable the TPM support library which provides
1629 functional interfaces to some TPM commands.
1630 Requires support for a TPM device.
1632 CONFIG_TPM_AUTH_SESSIONS
1633 Define this to enable authorized functions in the TPM library.
1634 Requires CONFIG_TPM and CONFIG_SHA1.
1637 At the moment only the UHCI host controller is
1638 supported (PIP405, MIP405, MPC5200); define
1639 CONFIG_USB_UHCI to enable it.
1640 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1641 and define CONFIG_USB_STORAGE to enable the USB
1644 Supported are USB Keyboards and USB Floppy drives
1646 MPC5200 USB requires additional defines:
1648 for 528 MHz Clock: 0x0001bbbb
1652 for differential drivers: 0x00001000
1653 for single ended drivers: 0x00005000
1654 for differential drivers on PSC3: 0x00000100
1655 for single ended drivers on PSC3: 0x00004100
1656 CONFIG_SYS_USB_EVENT_POLL
1657 May be defined to allow interrupt polling
1658 instead of using asynchronous interrupts
1660 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1661 txfilltuning field in the EHCI controller on reset.
1663 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1664 HW module registers.
1667 Define the below if you wish to use the USB console.
1668 Once firmware is rebuilt from a serial console issue the
1669 command "setenv stdin usbtty; setenv stdout usbtty" and
1670 attach your USB cable. The Unix command "dmesg" should print
1671 it has found a new device. The environment variable usbtty
1672 can be set to gserial or cdc_acm to enable your device to
1673 appear to a USB host as a Linux gserial device or a
1674 Common Device Class Abstract Control Model serial device.
1675 If you select usbtty = gserial you should be able to enumerate
1677 # modprobe usbserial vendor=0xVendorID product=0xProductID
1678 else if using cdc_acm, simply setting the environment
1679 variable usbtty to be cdc_acm should suffice. The following
1680 might be defined in YourBoardName.h
1683 Define this to build a UDC device
1686 Define this to have a tty type of device available to
1687 talk to the UDC device
1690 Define this to enable the high speed support for usb
1691 device and usbtty. If this feature is enabled, a routine
1692 int is_usbd_high_speed(void)
1693 also needs to be defined by the driver to dynamically poll
1694 whether the enumeration has succeded at high speed or full
1697 CONFIG_SYS_CONSOLE_IS_IN_ENV
1698 Define this if you want stdin, stdout &/or stderr to
1702 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1703 Derive USB clock from external clock "blah"
1704 - CONFIG_SYS_USB_EXTC_CLK 0x02
1706 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1707 Derive USB clock from brgclk
1708 - CONFIG_SYS_USB_BRG_CLK 0x04
1710 If you have a USB-IF assigned VendorID then you may wish to
1711 define your own vendor specific values either in BoardName.h
1712 or directly in usbd_vendor_info.h. If you don't define
1713 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1714 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1715 should pretend to be a Linux device to it's target host.
1717 CONFIG_USBD_MANUFACTURER
1718 Define this string as the name of your company for
1719 - CONFIG_USBD_MANUFACTURER "my company"
1721 CONFIG_USBD_PRODUCT_NAME
1722 Define this string as the name of your product
1723 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1725 CONFIG_USBD_VENDORID
1726 Define this as your assigned Vendor ID from the USB
1727 Implementors Forum. This *must* be a genuine Vendor ID
1728 to avoid polluting the USB namespace.
1729 - CONFIG_USBD_VENDORID 0xFFFF
1731 CONFIG_USBD_PRODUCTID
1732 Define this as the unique Product ID
1734 - CONFIG_USBD_PRODUCTID 0xFFFF
1736 - ULPI Layer Support:
1737 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1738 the generic ULPI layer. The generic layer accesses the ULPI PHY
1739 via the platform viewport, so you need both the genric layer and
1740 the viewport enabled. Currently only Chipidea/ARC based
1741 viewport is supported.
1742 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1743 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1744 If your ULPI phy needs a different reference clock than the
1745 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1746 the appropriate value in Hz.
1749 The MMC controller on the Intel PXA is supported. To
1750 enable this define CONFIG_MMC. The MMC can be
1751 accessed from the boot prompt by mapping the device
1752 to physical memory similar to flash. Command line is
1753 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1754 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1757 Support for Renesas on-chip MMCIF controller
1759 CONFIG_SH_MMCIF_ADDR
1760 Define the base address of MMCIF registers
1763 Define the clock frequency for MMCIF
1766 Enable the generic MMC driver
1768 CONFIG_SUPPORT_EMMC_BOOT
1769 Enable some additional features of the eMMC boot partitions.
1771 CONFIG_SUPPORT_EMMC_RPMB
1772 Enable the commands for reading, writing and programming the
1773 key for the Replay Protection Memory Block partition in eMMC.
1775 - USB Device Firmware Update (DFU) class support:
1776 CONFIG_USB_FUNCTION_DFU
1777 This enables the USB portion of the DFU USB class
1780 This enables the command "dfu" which is used to have
1781 U-Boot create a DFU class device via USB. This command
1782 requires that the "dfu_alt_info" environment variable be
1783 set and define the alt settings to expose to the host.
1786 This enables support for exposing (e)MMC devices via DFU.
1789 This enables support for exposing NAND devices via DFU.
1792 This enables support for exposing RAM via DFU.
1793 Note: DFU spec refer to non-volatile memory usage, but
1794 allow usages beyond the scope of spec - here RAM usage,
1795 one that would help mostly the developer.
1797 CONFIG_SYS_DFU_DATA_BUF_SIZE
1798 Dfu transfer uses a buffer before writing data to the
1799 raw storage device. Make the size (in bytes) of this buffer
1800 configurable. The size of this buffer is also configurable
1801 through the "dfu_bufsiz" environment variable.
1803 CONFIG_SYS_DFU_MAX_FILE_SIZE
1804 When updating files rather than the raw storage device,
1805 we use a static buffer to copy the file into and then write
1806 the buffer once we've been given the whole file. Define
1807 this to the maximum filesize (in bytes) for the buffer.
1808 Default is 4 MiB if undefined.
1810 DFU_DEFAULT_POLL_TIMEOUT
1811 Poll timeout [ms], is the timeout a device can send to the
1812 host. The host must wait for this timeout before sending
1813 a subsequent DFU_GET_STATUS request to the device.
1815 DFU_MANIFEST_POLL_TIMEOUT
1816 Poll timeout [ms], which the device sends to the host when
1817 entering dfuMANIFEST state. Host waits this timeout, before
1818 sending again an USB request to the device.
1820 - USB Device Android Fastboot support:
1821 CONFIG_USB_FUNCTION_FASTBOOT
1822 This enables the USB part of the fastboot gadget
1825 This enables the command "fastboot" which enables the Android
1826 fastboot mode for the platform's USB device. Fastboot is a USB
1827 protocol for downloading images, flashing and device control
1828 used on Android devices.
1829 See doc/README.android-fastboot for more information.
1831 CONFIG_ANDROID_BOOT_IMAGE
1832 This enables support for booting images which use the Android
1833 image format header.
1835 CONFIG_FASTBOOT_BUF_ADDR
1836 The fastboot protocol requires a large memory buffer for
1837 downloads. Define this to the starting RAM address to use for
1840 CONFIG_FASTBOOT_BUF_SIZE
1841 The fastboot protocol requires a large memory buffer for
1842 downloads. This buffer should be as large as possible for a
1843 platform. Define this to the size available RAM for fastboot.
1845 CONFIG_FASTBOOT_FLASH
1846 The fastboot protocol includes a "flash" command for writing
1847 the downloaded image to a non-volatile storage device. Define
1848 this to enable the "fastboot flash" command.
1850 CONFIG_FASTBOOT_FLASH_MMC_DEV
1851 The fastboot "flash" command requires additional information
1852 regarding the non-volatile storage device. Define this to
1853 the eMMC device that fastboot should use to store the image.
1855 CONFIG_FASTBOOT_GPT_NAME
1856 The fastboot "flash" command supports writing the downloaded
1857 image to the Protective MBR and the Primary GUID Partition
1858 Table. (Additionally, this downloaded image is post-processed
1859 to generate and write the Backup GUID Partition Table.)
1860 This occurs when the specified "partition name" on the
1861 "fastboot flash" command line matches this value.
1862 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1864 - Journaling Flash filesystem support:
1865 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1866 CONFIG_JFFS2_NAND_DEV
1867 Define these for a default partition on a NAND device
1869 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1870 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1871 Define these for a default partition on a NOR device
1873 CONFIG_SYS_JFFS_CUSTOM_PART
1874 Define this to create an own partition. You have to provide a
1875 function struct part_info* jffs2_part_info(int part_num)
1877 If you define only one JFFS2 partition you may also want to
1878 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1879 to disable the command chpart. This is the default when you
1880 have not defined a custom partition
1882 - FAT(File Allocation Table) filesystem write function support:
1885 Define this to enable support for saving memory data as a
1886 file in FAT formatted partition.
1888 This will also enable the command "fatwrite" enabling the
1889 user to write files to FAT.
1891 CBFS (Coreboot Filesystem) support
1894 Define this to enable support for reading from a Coreboot
1895 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1898 - FAT(File Allocation Table) filesystem cluster size:
1899 CONFIG_FS_FAT_MAX_CLUSTSIZE
1901 Define the max cluster size for fat operations else
1902 a default value of 65536 will be defined.
1907 Define this to enable standard (PC-Style) keyboard
1911 Standard PC keyboard driver with US (is default) and
1912 GERMAN key layout (switch via environment 'keymap=de') support.
1913 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1914 for cfb_console. Supports cursor blinking.
1917 Enables a Chrome OS keyboard using the CROS_EC interface.
1918 This uses CROS_EC to communicate with a second microcontroller
1919 which provides key scans on request.
1924 Define this to enable video support (for output to
1927 CONFIG_VIDEO_CT69000
1929 Enable Chips & Technologies 69000 Video chip
1931 CONFIG_VIDEO_SMI_LYNXEM
1932 Enable Silicon Motion SMI 712/710/810 Video chip. The
1933 video output is selected via environment 'videoout'
1934 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1937 For the CT69000 and SMI_LYNXEM drivers, videomode is
1938 selected via environment 'videomode'. Two different ways
1940 - "videomode=num" 'num' is a standard LiLo mode numbers.
1941 Following standard modes are supported (* is default):
1943 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1944 -------------+---------------------------------------------
1945 8 bits | 0x301* 0x303 0x305 0x161 0x307
1946 15 bits | 0x310 0x313 0x316 0x162 0x319
1947 16 bits | 0x311 0x314 0x317 0x163 0x31A
1948 24 bits | 0x312 0x315 0x318 ? 0x31B
1949 -------------+---------------------------------------------
1950 (i.e. setenv videomode 317; saveenv; reset;)
1952 - "videomode=bootargs" all the video parameters are parsed
1953 from the bootargs. (See drivers/video/videomodes.c)
1956 CONFIG_VIDEO_SED13806
1957 Enable Epson SED13806 driver. This driver supports 8bpp
1958 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1959 or CONFIG_VIDEO_SED13806_16BPP
1962 Enable the Freescale DIU video driver. Reference boards for
1963 SOCs that have a DIU should define this macro to enable DIU
1964 support, and should also define these other macros:
1970 CONFIG_VIDEO_SW_CURSOR
1971 CONFIG_VGA_AS_SINGLE_DEVICE
1973 CONFIG_VIDEO_BMP_LOGO
1975 The DIU driver will look for the 'video-mode' environment
1976 variable, and if defined, enable the DIU as a console during
1977 boot. See the documentation file README.video for a
1978 description of this variable.
1984 Define this to enable a custom keyboard support.
1985 This simply calls drv_keyboard_init() which must be
1986 defined in your board-specific files.
1987 The only board using this so far is RBC823.
1989 - LCD Support: CONFIG_LCD
1991 Define this to enable LCD support (for output to LCD
1992 display); also select one of the supported displays
1993 by defining one of these:
1997 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1999 CONFIG_NEC_NL6448AC33:
2001 NEC NL6448AC33-18. Active, color, single scan.
2003 CONFIG_NEC_NL6448BC20
2005 NEC NL6448BC20-08. 6.5", 640x480.
2006 Active, color, single scan.
2008 CONFIG_NEC_NL6448BC33_54
2010 NEC NL6448BC33-54. 10.4", 640x480.
2011 Active, color, single scan.
2015 Sharp 320x240. Active, color, single scan.
2016 It isn't 16x9, and I am not sure what it is.
2018 CONFIG_SHARP_LQ64D341
2020 Sharp LQ64D341 display, 640x480.
2021 Active, color, single scan.
2025 HLD1045 display, 640x480.
2026 Active, color, single scan.
2030 Optrex CBL50840-2 NF-FW 99 22 M5
2032 Hitachi LMG6912RPFC-00T
2036 320x240. Black & white.
2038 Normally display is black on white background; define
2039 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2041 CONFIG_LCD_ALIGNMENT
2043 Normally the LCD is page-aligned (typically 4KB). If this is
2044 defined then the LCD will be aligned to this value instead.
2045 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2046 here, since it is cheaper to change data cache settings on
2047 a per-section basis.
2049 CONFIG_CONSOLE_SCROLL_LINES
2051 When the console need to be scrolled, this is the number of
2052 lines to scroll by. It defaults to 1. Increasing this makes
2053 the console jump but can help speed up operation when scrolling
2058 Sometimes, for example if the display is mounted in portrait
2059 mode or even if it's mounted landscape but rotated by 180degree,
2060 we need to rotate our content of the display relative to the
2061 framebuffer, so that user can read the messages which are
2063 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2064 initialized with a given rotation from "vl_rot" out of
2065 "vidinfo_t" which is provided by the board specific code.
2066 The value for vl_rot is coded as following (matching to
2067 fbcon=rotate:<n> linux-kernel commandline):
2068 0 = no rotation respectively 0 degree
2069 1 = 90 degree rotation
2070 2 = 180 degree rotation
2071 3 = 270 degree rotation
2073 If CONFIG_LCD_ROTATION is not defined, the console will be
2074 initialized with 0degree rotation.
2078 Support drawing of RLE8-compressed bitmaps on the LCD.
2082 Enables an 'i2c edid' command which can read EDID
2083 information over I2C from an attached LCD display.
2085 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2087 If this option is set, the environment is checked for
2088 a variable "splashimage". If found, the usual display
2089 of logo, copyright and system information on the LCD
2090 is suppressed and the BMP image at the address
2091 specified in "splashimage" is loaded instead. The
2092 console is redirected to the "nulldev", too. This
2093 allows for a "silent" boot where a splash screen is
2094 loaded very quickly after power-on.
2096 CONFIG_SPLASHIMAGE_GUARD
2098 If this option is set, then U-Boot will prevent the environment
2099 variable "splashimage" from being set to a problematic address
2100 (see README.displaying-bmps).
2101 This option is useful for targets where, due to alignment
2102 restrictions, an improperly aligned BMP image will cause a data
2103 abort. If you think you will not have problems with unaligned
2104 accesses (for example because your toolchain prevents them)
2105 there is no need to set this option.
2107 CONFIG_SPLASH_SCREEN_ALIGN
2109 If this option is set the splash image can be freely positioned
2110 on the screen. Environment variable "splashpos" specifies the
2111 position as "x,y". If a positive number is given it is used as
2112 number of pixel from left/top. If a negative number is given it
2113 is used as number of pixel from right/bottom. You can also
2114 specify 'm' for centering the image.
2117 setenv splashpos m,m
2118 => image at center of screen
2120 setenv splashpos 30,20
2121 => image at x = 30 and y = 20
2123 setenv splashpos -10,m
2124 => vertically centered image
2125 at x = dspWidth - bmpWidth - 9
2127 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2129 If this option is set, additionally to standard BMP
2130 images, gzipped BMP images can be displayed via the
2131 splashscreen support or the bmp command.
2133 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2135 If this option is set, 8-bit RLE compressed BMP images
2136 can be displayed via the splashscreen support or the
2139 - Do compressing for memory range:
2142 If this option is set, it would use zlib deflate method
2143 to compress the specified memory at its best effort.
2145 - Compression support:
2148 Enabled by default to support gzip compressed images.
2152 If this option is set, support for bzip2 compressed
2153 images is included. If not, only uncompressed and gzip
2154 compressed images are supported.
2156 NOTE: the bzip2 algorithm requires a lot of RAM, so
2157 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2162 If this option is set, support for lzma compressed
2165 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2166 requires an amount of dynamic memory that is given by the
2169 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2171 Where lc and lp stand for, respectively, Literal context bits
2172 and Literal pos bits.
2174 This value is upper-bounded by 14MB in the worst case. Anyway,
2175 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2176 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2177 a very small buffer.
2179 Use the lzmainfo tool to determinate the lc and lp values and
2180 then calculate the amount of needed dynamic memory (ensuring
2181 the appropriate CONFIG_SYS_MALLOC_LEN value).
2185 If this option is set, support for LZO compressed images
2191 The address of PHY on MII bus.
2193 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2195 The clock frequency of the MII bus
2199 If this option is set, support for speed/duplex
2200 detection of gigabit PHY is included.
2202 CONFIG_PHY_RESET_DELAY
2204 Some PHY like Intel LXT971A need extra delay after
2205 reset before any MII register access is possible.
2206 For such PHY, set this option to the usec delay
2207 required. (minimum 300usec for LXT971A)
2209 CONFIG_PHY_CMD_DELAY (ppc4xx)
2211 Some PHY like Intel LXT971A need extra delay after
2212 command issued before MII status register can be read
2217 Define a default value for the IP address to use for
2218 the default Ethernet interface, in case this is not
2219 determined through e.g. bootp.
2220 (Environment variable "ipaddr")
2222 - Server IP address:
2225 Defines a default value for the IP address of a TFTP
2226 server to contact when using the "tftboot" command.
2227 (Environment variable "serverip")
2229 CONFIG_KEEP_SERVERADDR
2231 Keeps the server's MAC address, in the env 'serveraddr'
2232 for passing to bootargs (like Linux's netconsole option)
2234 - Gateway IP address:
2237 Defines a default value for the IP address of the
2238 default router where packets to other networks are
2240 (Environment variable "gatewayip")
2245 Defines a default value for the subnet mask (or
2246 routing prefix) which is used to determine if an IP
2247 address belongs to the local subnet or needs to be
2248 forwarded through a router.
2249 (Environment variable "netmask")
2251 - Multicast TFTP Mode:
2254 Defines whether you want to support multicast TFTP as per
2255 rfc-2090; for example to work with atftp. Lets lots of targets
2256 tftp down the same boot image concurrently. Note: the Ethernet
2257 driver in use must provide a function: mcast() to join/leave a
2260 - BOOTP Recovery Mode:
2261 CONFIG_BOOTP_RANDOM_DELAY
2263 If you have many targets in a network that try to
2264 boot using BOOTP, you may want to avoid that all
2265 systems send out BOOTP requests at precisely the same
2266 moment (which would happen for instance at recovery
2267 from a power failure, when all systems will try to
2268 boot, thus flooding the BOOTP server. Defining
2269 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2270 inserted before sending out BOOTP requests. The
2271 following delays are inserted then:
2273 1st BOOTP request: delay 0 ... 1 sec
2274 2nd BOOTP request: delay 0 ... 2 sec
2275 3rd BOOTP request: delay 0 ... 4 sec
2277 BOOTP requests: delay 0 ... 8 sec
2279 CONFIG_BOOTP_ID_CACHE_SIZE
2281 BOOTP packets are uniquely identified using a 32-bit ID. The
2282 server will copy the ID from client requests to responses and
2283 U-Boot will use this to determine if it is the destination of
2284 an incoming response. Some servers will check that addresses
2285 aren't in use before handing them out (usually using an ARP
2286 ping) and therefore take up to a few hundred milliseconds to
2287 respond. Network congestion may also influence the time it
2288 takes for a response to make it back to the client. If that
2289 time is too long, U-Boot will retransmit requests. In order
2290 to allow earlier responses to still be accepted after these
2291 retransmissions, U-Boot's BOOTP client keeps a small cache of
2292 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2293 cache. The default is to keep IDs for up to four outstanding
2294 requests. Increasing this will allow U-Boot to accept offers
2295 from a BOOTP client in networks with unusually high latency.
2297 - BOOTP Random transaction ID:
2298 CONFIG_BOOTP_RANDOM_ID
2300 The standard algorithm to generate a DHCP/BOOTP transaction ID
2301 by using the MAC address and the current time stamp may not
2302 quite unlikely produce duplicate transaction IDs from different
2303 clients in the same network. This option creates a transaction
2304 ID using the rand() function. Provided that the RNG has been
2305 seeded well, this should guarantee unique transaction IDs
2308 - DHCP Advanced Options:
2309 You can fine tune the DHCP functionality by defining
2310 CONFIG_BOOTP_* symbols:
2312 CONFIG_BOOTP_SUBNETMASK
2313 CONFIG_BOOTP_GATEWAY
2314 CONFIG_BOOTP_HOSTNAME
2315 CONFIG_BOOTP_NISDOMAIN
2316 CONFIG_BOOTP_BOOTPATH
2317 CONFIG_BOOTP_BOOTFILESIZE
2320 CONFIG_BOOTP_SEND_HOSTNAME
2321 CONFIG_BOOTP_NTPSERVER
2322 CONFIG_BOOTP_TIMEOFFSET
2323 CONFIG_BOOTP_VENDOREX
2324 CONFIG_BOOTP_MAY_FAIL
2326 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2327 environment variable, not the BOOTP server.
2329 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2330 after the configured retry count, the call will fail
2331 instead of starting over. This can be used to fail over
2332 to Link-local IP address configuration if the DHCP server
2335 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2336 serverip from a DHCP server, it is possible that more
2337 than one DNS serverip is offered to the client.
2338 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2339 serverip will be stored in the additional environment
2340 variable "dnsip2". The first DNS serverip is always
2341 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2344 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2345 to do a dynamic update of a DNS server. To do this, they
2346 need the hostname of the DHCP requester.
2347 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2348 of the "hostname" environment variable is passed as
2349 option 12 to the DHCP server.
2351 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2353 A 32bit value in microseconds for a delay between
2354 receiving a "DHCP Offer" and sending the "DHCP Request".
2355 This fixes a problem with certain DHCP servers that don't
2356 respond 100% of the time to a "DHCP request". E.g. On an
2357 AT91RM9200 processor running at 180MHz, this delay needed
2358 to be *at least* 15,000 usec before a Windows Server 2003
2359 DHCP server would reply 100% of the time. I recommend at
2360 least 50,000 usec to be safe. The alternative is to hope
2361 that one of the retries will be successful but note that
2362 the DHCP timeout and retry process takes a longer than
2365 - Link-local IP address negotiation:
2366 Negotiate with other link-local clients on the local network
2367 for an address that doesn't require explicit configuration.
2368 This is especially useful if a DHCP server cannot be guaranteed
2369 to exist in all environments that the device must operate.
2371 See doc/README.link-local for more information.
2374 CONFIG_CDP_DEVICE_ID
2376 The device id used in CDP trigger frames.
2378 CONFIG_CDP_DEVICE_ID_PREFIX
2380 A two character string which is prefixed to the MAC address
2385 A printf format string which contains the ascii name of
2386 the port. Normally is set to "eth%d" which sets
2387 eth0 for the first Ethernet, eth1 for the second etc.
2389 CONFIG_CDP_CAPABILITIES
2391 A 32bit integer which indicates the device capabilities;
2392 0x00000010 for a normal host which does not forwards.
2396 An ascii string containing the version of the software.
2400 An ascii string containing the name of the platform.
2404 A 32bit integer sent on the trigger.
2406 CONFIG_CDP_POWER_CONSUMPTION
2408 A 16bit integer containing the power consumption of the
2409 device in .1 of milliwatts.
2411 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2413 A byte containing the id of the VLAN.
2415 - Status LED: CONFIG_STATUS_LED
2417 Several configurations allow to display the current
2418 status using a LED. For instance, the LED will blink
2419 fast while running U-Boot code, stop blinking as
2420 soon as a reply to a BOOTP request was received, and
2421 start blinking slow once the Linux kernel is running
2422 (supported by a status LED driver in the Linux
2423 kernel). Defining CONFIG_STATUS_LED enables this
2429 The status LED can be connected to a GPIO pin.
2430 In such cases, the gpio_led driver can be used as a
2431 status LED backend implementation. Define CONFIG_GPIO_LED
2432 to include the gpio_led driver in the U-Boot binary.
2434 CONFIG_GPIO_LED_INVERTED_TABLE
2435 Some GPIO connected LEDs may have inverted polarity in which
2436 case the GPIO high value corresponds to LED off state and
2437 GPIO low value corresponds to LED on state.
2438 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2439 with a list of GPIO LEDs that have inverted polarity.
2441 - CAN Support: CONFIG_CAN_DRIVER
2443 Defining CONFIG_CAN_DRIVER enables CAN driver support
2444 on those systems that support this (optional)
2445 feature, like the TQM8xxL modules.
2447 - I2C Support: CONFIG_SYS_I2C
2449 This enable the NEW i2c subsystem, and will allow you to use
2450 i2c commands at the u-boot command line (as long as you set
2451 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2452 based realtime clock chips or other i2c devices. See
2453 common/cmd_i2c.c for a description of the command line
2456 ported i2c driver to the new framework:
2457 - drivers/i2c/soft_i2c.c:
2458 - activate first bus with CONFIG_SYS_I2C_SOFT define
2459 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2460 for defining speed and slave address
2461 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2462 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2463 for defining speed and slave address
2464 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2465 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2466 for defining speed and slave address
2467 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2468 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2469 for defining speed and slave address
2471 - drivers/i2c/fsl_i2c.c:
2472 - activate i2c driver with CONFIG_SYS_I2C_FSL
2473 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2474 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2475 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2477 - If your board supports a second fsl i2c bus, define
2478 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2479 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2480 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2483 - drivers/i2c/tegra_i2c.c:
2484 - activate this driver with CONFIG_SYS_I2C_TEGRA
2485 - This driver adds 4 i2c buses with a fix speed from
2486 100000 and the slave addr 0!
2488 - drivers/i2c/ppc4xx_i2c.c
2489 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2490 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2491 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2493 - drivers/i2c/i2c_mxc.c
2494 - activate this driver with CONFIG_SYS_I2C_MXC
2495 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2496 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2497 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2498 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2499 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2500 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2501 If those defines are not set, default value is 100000
2502 for speed, and 0 for slave.
2503 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2504 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2506 - drivers/i2c/rcar_i2c.c:
2507 - activate this driver with CONFIG_SYS_I2C_RCAR
2508 - This driver adds 4 i2c buses
2510 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2511 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2512 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2513 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2514 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2515 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2516 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2517 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2518 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2520 - drivers/i2c/sh_i2c.c:
2521 - activate this driver with CONFIG_SYS_I2C_SH
2522 - This driver adds from 2 to 5 i2c buses
2524 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2525 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2526 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2527 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2528 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2529 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2530 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2531 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2532 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2533 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2534 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2535 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2536 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2538 - drivers/i2c/omap24xx_i2c.c
2539 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2540 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2541 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2542 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2543 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2544 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2545 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2546 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2547 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2548 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2549 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2551 - drivers/i2c/zynq_i2c.c
2552 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2553 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2554 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2556 - drivers/i2c/s3c24x0_i2c.c:
2557 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2558 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2559 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2560 with a fix speed from 100000 and the slave addr 0!
2562 - drivers/i2c/ihs_i2c.c
2563 - activate this driver with CONFIG_SYS_I2C_IHS
2564 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2565 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2566 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2567 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2568 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2569 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2570 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2571 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2572 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2573 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2574 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2575 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2579 CONFIG_SYS_NUM_I2C_BUSES
2580 Hold the number of i2c buses you want to use. If you
2581 don't use/have i2c muxes on your i2c bus, this
2582 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2585 CONFIG_SYS_I2C_DIRECT_BUS
2586 define this, if you don't use i2c muxes on your hardware.
2587 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2590 CONFIG_SYS_I2C_MAX_HOPS
2591 define how many muxes are maximal consecutively connected
2592 on one i2c bus. If you not use i2c muxes, omit this
2595 CONFIG_SYS_I2C_BUSES
2596 hold a list of buses you want to use, only used if
2597 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2598 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2599 CONFIG_SYS_NUM_I2C_BUSES = 9:
2601 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2602 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2603 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2604 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2605 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2606 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2607 {1, {I2C_NULL_HOP}}, \
2608 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2609 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2613 bus 0 on adapter 0 without a mux
2614 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2615 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2616 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2617 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2618 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2619 bus 6 on adapter 1 without a mux
2620 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2621 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2623 If you do not have i2c muxes on your board, omit this define.
2625 - Legacy I2C Support: CONFIG_HARD_I2C
2627 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2628 provides the following compelling advantages:
2630 - more than one i2c adapter is usable
2631 - approved multibus support
2632 - better i2c mux support
2634 ** Please consider updating your I2C driver now. **
2636 These enable legacy I2C serial bus commands. Defining
2637 CONFIG_HARD_I2C will include the appropriate I2C driver
2638 for the selected CPU.
2640 This will allow you to use i2c commands at the u-boot
2641 command line (as long as you set CONFIG_CMD_I2C in
2642 CONFIG_COMMANDS) and communicate with i2c based realtime
2643 clock chips. See common/cmd_i2c.c for a description of the
2644 command line interface.
2646 CONFIG_HARD_I2C selects a hardware I2C controller.
2648 There are several other quantities that must also be
2649 defined when you define CONFIG_HARD_I2C.
2651 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2652 to be the frequency (in Hz) at which you wish your i2c bus
2653 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2654 the CPU's i2c node address).
2656 Now, the u-boot i2c code for the mpc8xx
2657 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2658 and so its address should therefore be cleared to 0 (See,
2659 eg, MPC823e User's Manual p.16-473). So, set
2660 CONFIG_SYS_I2C_SLAVE to 0.
2662 CONFIG_SYS_I2C_INIT_MPC5XXX
2664 When a board is reset during an i2c bus transfer
2665 chips might think that the current transfer is still
2666 in progress. Reset the slave devices by sending start
2667 commands until the slave device responds.
2669 That's all that's required for CONFIG_HARD_I2C.
2671 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2672 then the following macros need to be defined (examples are
2673 from include/configs/lwmon.h):
2677 (Optional). Any commands necessary to enable the I2C
2678 controller or configure ports.
2680 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2684 (Only for MPC8260 CPU). The I/O port to use (the code
2685 assumes both bits are on the same port). Valid values
2686 are 0..3 for ports A..D.
2690 The code necessary to make the I2C data line active
2691 (driven). If the data line is open collector, this
2694 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2698 The code necessary to make the I2C data line tri-stated
2699 (inactive). If the data line is open collector, this
2702 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2706 Code that returns true if the I2C data line is high,
2709 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2713 If <bit> is true, sets the I2C data line high. If it
2714 is false, it clears it (low).
2716 eg: #define I2C_SDA(bit) \
2717 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2718 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2722 If <bit> is true, sets the I2C clock line high. If it
2723 is false, it clears it (low).
2725 eg: #define I2C_SCL(bit) \
2726 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2727 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2731 This delay is invoked four times per clock cycle so this
2732 controls the rate of data transfer. The data rate thus
2733 is 1 / (I2C_DELAY * 4). Often defined to be something
2736 #define I2C_DELAY udelay(2)
2738 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2740 If your arch supports the generic GPIO framework (asm/gpio.h),
2741 then you may alternatively define the two GPIOs that are to be
2742 used as SCL / SDA. Any of the previous I2C_xxx macros will
2743 have GPIO-based defaults assigned to them as appropriate.
2745 You should define these to the GPIO value as given directly to
2746 the generic GPIO functions.
2748 CONFIG_SYS_I2C_INIT_BOARD
2750 When a board is reset during an i2c bus transfer
2751 chips might think that the current transfer is still
2752 in progress. On some boards it is possible to access
2753 the i2c SCLK line directly, either by using the
2754 processor pin as a GPIO or by having a second pin
2755 connected to the bus. If this option is defined a
2756 custom i2c_init_board() routine in boards/xxx/board.c
2757 is run early in the boot sequence.
2759 CONFIG_SYS_I2C_BOARD_LATE_INIT
2761 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2762 defined a custom i2c_board_late_init() routine in
2763 boards/xxx/board.c is run AFTER the operations in i2c_init()
2764 is completed. This callpoint can be used to unreset i2c bus
2765 using CPU i2c controller register accesses for CPUs whose i2c
2766 controller provide such a method. It is called at the end of
2767 i2c_init() to allow i2c_init operations to setup the i2c bus
2768 controller on the CPU (e.g. setting bus speed & slave address).
2770 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2772 This option enables configuration of bi_iic_fast[] flags
2773 in u-boot bd_info structure based on u-boot environment
2774 variable "i2cfast". (see also i2cfast)
2776 CONFIG_I2C_MULTI_BUS
2778 This option allows the use of multiple I2C buses, each of which
2779 must have a controller. At any point in time, only one bus is
2780 active. To switch to a different bus, use the 'i2c dev' command.
2781 Note that bus numbering is zero-based.
2783 CONFIG_SYS_I2C_NOPROBES
2785 This option specifies a list of I2C devices that will be skipped
2786 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2787 is set, specify a list of bus-device pairs. Otherwise, specify
2788 a 1D array of device addresses
2791 #undef CONFIG_I2C_MULTI_BUS
2792 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2794 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2796 #define CONFIG_I2C_MULTI_BUS
2797 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2799 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2801 CONFIG_SYS_SPD_BUS_NUM
2803 If defined, then this indicates the I2C bus number for DDR SPD.
2804 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2806 CONFIG_SYS_RTC_BUS_NUM
2808 If defined, then this indicates the I2C bus number for the RTC.
2809 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2811 CONFIG_SYS_DTT_BUS_NUM
2813 If defined, then this indicates the I2C bus number for the DTT.
2814 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2816 CONFIG_SYS_I2C_DTT_ADDR:
2818 If defined, specifies the I2C address of the DTT device.
2819 If not defined, then U-Boot uses predefined value for
2820 specified DTT device.
2822 CONFIG_SOFT_I2C_READ_REPEATED_START
2824 defining this will force the i2c_read() function in
2825 the soft_i2c driver to perform an I2C repeated start
2826 between writing the address pointer and reading the
2827 data. If this define is omitted the default behaviour
2828 of doing a stop-start sequence will be used. Most I2C
2829 devices can use either method, but some require one or
2832 - SPI Support: CONFIG_SPI
2834 Enables SPI driver (so far only tested with
2835 SPI EEPROM, also an instance works with Crystal A/D and
2836 D/As on the SACSng board)
2840 Enables the driver for SPI controller on SuperH. Currently
2841 only SH7757 is supported.
2845 Enables extended (16-bit) SPI EEPROM addressing.
2846 (symmetrical to CONFIG_I2C_X)
2850 Enables a software (bit-bang) SPI driver rather than
2851 using hardware support. This is a general purpose
2852 driver that only requires three general I/O port pins
2853 (two outputs, one input) to function. If this is
2854 defined, the board configuration must define several
2855 SPI configuration items (port pins to use, etc). For
2856 an example, see include/configs/sacsng.h.
2860 Enables a hardware SPI driver for general-purpose reads
2861 and writes. As with CONFIG_SOFT_SPI, the board configuration
2862 must define a list of chip-select function pointers.
2863 Currently supported on some MPC8xxx processors. For an
2864 example, see include/configs/mpc8349emds.h.
2868 Enables the driver for the SPI controllers on i.MX and MXC
2869 SoCs. Currently i.MX31/35/51 are supported.
2871 CONFIG_SYS_SPI_MXC_WAIT
2872 Timeout for waiting until spi transfer completed.
2873 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2875 - FPGA Support: CONFIG_FPGA
2877 Enables FPGA subsystem.
2879 CONFIG_FPGA_<vendor>
2881 Enables support for specific chip vendors.
2884 CONFIG_FPGA_<family>
2886 Enables support for FPGA family.
2887 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2891 Specify the number of FPGA devices to support.
2893 CONFIG_CMD_FPGA_LOADMK
2895 Enable support for fpga loadmk command
2897 CONFIG_CMD_FPGA_LOADP
2899 Enable support for fpga loadp command - load partial bitstream
2901 CONFIG_CMD_FPGA_LOADBP
2903 Enable support for fpga loadbp command - load partial bitstream
2906 CONFIG_SYS_FPGA_PROG_FEEDBACK
2908 Enable printing of hash marks during FPGA configuration.
2910 CONFIG_SYS_FPGA_CHECK_BUSY
2912 Enable checks on FPGA configuration interface busy
2913 status by the configuration function. This option
2914 will require a board or device specific function to
2919 If defined, a function that provides delays in the FPGA
2920 configuration driver.
2922 CONFIG_SYS_FPGA_CHECK_CTRLC
2923 Allow Control-C to interrupt FPGA configuration
2925 CONFIG_SYS_FPGA_CHECK_ERROR
2927 Check for configuration errors during FPGA bitfile
2928 loading. For example, abort during Virtex II
2929 configuration if the INIT_B line goes low (which
2930 indicated a CRC error).
2932 CONFIG_SYS_FPGA_WAIT_INIT
2934 Maximum time to wait for the INIT_B line to de-assert
2935 after PROB_B has been de-asserted during a Virtex II
2936 FPGA configuration sequence. The default time is 500
2939 CONFIG_SYS_FPGA_WAIT_BUSY
2941 Maximum time to wait for BUSY to de-assert during
2942 Virtex II FPGA configuration. The default is 5 ms.
2944 CONFIG_SYS_FPGA_WAIT_CONFIG
2946 Time to wait after FPGA configuration. The default is
2949 - Configuration Management:
2952 Some SoCs need special image types (e.g. U-Boot binary
2953 with a special header) as build targets. By defining
2954 CONFIG_BUILD_TARGET in the SoC / board header, this
2955 special image will be automatically built upon calling
2960 If defined, this string will be added to the U-Boot
2961 version information (U_BOOT_VERSION)
2963 - Vendor Parameter Protection:
2965 U-Boot considers the values of the environment
2966 variables "serial#" (Board Serial Number) and
2967 "ethaddr" (Ethernet Address) to be parameters that
2968 are set once by the board vendor / manufacturer, and
2969 protects these variables from casual modification by
2970 the user. Once set, these variables are read-only,
2971 and write or delete attempts are rejected. You can
2972 change this behaviour:
2974 If CONFIG_ENV_OVERWRITE is #defined in your config
2975 file, the write protection for vendor parameters is
2976 completely disabled. Anybody can change or delete
2979 Alternatively, if you define _both_ an ethaddr in the
2980 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2981 Ethernet address is installed in the environment,
2982 which can be changed exactly ONCE by the user. [The
2983 serial# is unaffected by this, i. e. it remains
2986 The same can be accomplished in a more flexible way
2987 for any variable by configuring the type of access
2988 to allow for those variables in the ".flags" variable
2989 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2994 Define this variable to enable the reservation of
2995 "protected RAM", i. e. RAM which is not overwritten
2996 by U-Boot. Define CONFIG_PRAM to hold the number of
2997 kB you want to reserve for pRAM. You can overwrite
2998 this default value by defining an environment
2999 variable "pram" to the number of kB you want to
3000 reserve. Note that the board info structure will
3001 still show the full amount of RAM. If pRAM is
3002 reserved, a new environment variable "mem" will
3003 automatically be defined to hold the amount of
3004 remaining RAM in a form that can be passed as boot
3005 argument to Linux, for instance like that:
3007 setenv bootargs ... mem=\${mem}
3010 This way you can tell Linux not to use this memory,
3011 either, which results in a memory region that will
3012 not be affected by reboots.
3014 *WARNING* If your board configuration uses automatic
3015 detection of the RAM size, you must make sure that
3016 this memory test is non-destructive. So far, the
3017 following board configurations are known to be
3020 IVMS8, IVML24, SPD8xx, TQM8xxL,
3021 HERMES, IP860, RPXlite, LWMON,
3024 - Access to physical memory region (> 4GB)
3025 Some basic support is provided for operations on memory not
3026 normally accessible to U-Boot - e.g. some architectures
3027 support access to more than 4GB of memory on 32-bit
3028 machines using physical address extension or similar.
3029 Define CONFIG_PHYSMEM to access this basic support, which
3030 currently only supports clearing the memory.
3035 Define this variable to stop the system in case of a
3036 fatal error, so that you have to reset it manually.
3037 This is probably NOT a good idea for an embedded
3038 system where you want the system to reboot
3039 automatically as fast as possible, but it may be
3040 useful during development since you can try to debug
3041 the conditions that lead to the situation.
3043 CONFIG_NET_RETRY_COUNT
3045 This variable defines the number of retries for
3046 network operations like ARP, RARP, TFTP, or BOOTP
3047 before giving up the operation. If not defined, a
3048 default value of 5 is used.
3052 Timeout waiting for an ARP reply in milliseconds.
3056 Timeout in milliseconds used in NFS protocol.
3057 If you encounter "ERROR: Cannot umount" in nfs command,
3058 try longer timeout such as
3059 #define CONFIG_NFS_TIMEOUT 10000UL
3061 - Command Interpreter:
3062 CONFIG_AUTO_COMPLETE
3064 Enable auto completion of commands using TAB.
3066 CONFIG_SYS_PROMPT_HUSH_PS2
3068 This defines the secondary prompt string, which is
3069 printed when the command interpreter needs more input
3070 to complete a command. Usually "> ".
3074 In the current implementation, the local variables
3075 space and global environment variables space are
3076 separated. Local variables are those you define by
3077 simply typing `name=value'. To access a local
3078 variable later on, you have write `$name' or
3079 `${name}'; to execute the contents of a variable
3080 directly type `$name' at the command prompt.
3082 Global environment variables are those you use
3083 setenv/printenv to work with. To run a command stored
3084 in such a variable, you need to use the run command,
3085 and you must not use the '$' sign to access them.
3087 To store commands and special characters in a
3088 variable, please use double quotation marks
3089 surrounding the whole text of the variable, instead
3090 of the backslashes before semicolons and special
3093 - Command Line Editing and History:
3094 CONFIG_CMDLINE_EDITING
3096 Enable editing and History functions for interactive
3097 command line input operations
3099 - Default Environment:
3100 CONFIG_EXTRA_ENV_SETTINGS
3102 Define this to contain any number of null terminated
3103 strings (variable = value pairs) that will be part of
3104 the default environment compiled into the boot image.
3106 For example, place something like this in your
3107 board's config file:
3109 #define CONFIG_EXTRA_ENV_SETTINGS \
3113 Warning: This method is based on knowledge about the
3114 internal format how the environment is stored by the
3115 U-Boot code. This is NOT an official, exported
3116 interface! Although it is unlikely that this format
3117 will change soon, there is no guarantee either.
3118 You better know what you are doing here.
3120 Note: overly (ab)use of the default environment is
3121 discouraged. Make sure to check other ways to preset
3122 the environment like the "source" command or the
3125 CONFIG_ENV_VARS_UBOOT_CONFIG
3127 Define this in order to add variables describing the
3128 U-Boot build configuration to the default environment.
3129 These will be named arch, cpu, board, vendor, and soc.
3131 Enabling this option will cause the following to be defined:
3139 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3141 Define this in order to add variables describing certain
3142 run-time determined information about the hardware to the
3143 environment. These will be named board_name, board_rev.
3145 CONFIG_DELAY_ENVIRONMENT
3147 Normally the environment is loaded when the board is
3148 initialised so that it is available to U-Boot. This inhibits
3149 that so that the environment is not available until
3150 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3151 this is instead controlled by the value of
3152 /config/load-environment.
3154 - Parallel Flash support:
3157 Traditionally U-boot was run on systems with parallel NOR
3158 flash. This option is used to disable support for parallel NOR
3159 flash. This option should be defined if the board does not have
3162 If this option is not defined one of the generic flash drivers
3163 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3164 selected or the board must provide an implementation of the
3165 flash API (see include/flash.h).
3167 - DataFlash Support:
3168 CONFIG_HAS_DATAFLASH
3170 Defining this option enables DataFlash features and
3171 allows to read/write in Dataflash via the standard
3174 - Serial Flash support
3177 Defining this option enables SPI flash commands
3178 'sf probe/read/write/erase/update'.
3180 Usage requires an initial 'probe' to define the serial
3181 flash parameters, followed by read/write/erase/update
3184 The following defaults may be provided by the platform
3185 to handle the common case when only a single serial
3186 flash is present on the system.
3188 CONFIG_SF_DEFAULT_BUS Bus identifier
3189 CONFIG_SF_DEFAULT_CS Chip-select
3190 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3191 CONFIG_SF_DEFAULT_SPEED in Hz
3195 Define this option to include a destructive SPI flash
3198 CONFIG_SF_DUAL_FLASH Dual flash memories
3200 Define this option to use dual flash support where two flash
3201 memories can be connected with a given cs line.
3202 Currently Xilinx Zynq qspi supports these type of connections.
3204 - SystemACE Support:
3207 Adding this option adds support for Xilinx SystemACE
3208 chips attached via some sort of local bus. The address
3209 of the chip must also be defined in the
3210 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3212 #define CONFIG_SYSTEMACE
3213 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3215 When SystemACE support is added, the "ace" device type
3216 becomes available to the fat commands, i.e. fatls.
3218 - TFTP Fixed UDP Port:
3221 If this is defined, the environment variable tftpsrcp
3222 is used to supply the TFTP UDP source port value.
3223 If tftpsrcp isn't defined, the normal pseudo-random port
3224 number generator is used.
3226 Also, the environment variable tftpdstp is used to supply
3227 the TFTP UDP destination port value. If tftpdstp isn't
3228 defined, the normal port 69 is used.
3230 The purpose for tftpsrcp is to allow a TFTP server to
3231 blindly start the TFTP transfer using the pre-configured
3232 target IP address and UDP port. This has the effect of
3233 "punching through" the (Windows XP) firewall, allowing
3234 the remainder of the TFTP transfer to proceed normally.
3235 A better solution is to properly configure the firewall,
3236 but sometimes that is not allowed.
3241 This enables a generic 'hash' command which can produce
3242 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3246 Enable the hash verify command (hash -v). This adds to code
3249 CONFIG_SHA1 - This option enables support of hashing using SHA1
3250 algorithm. The hash is calculated in software.
3251 CONFIG_SHA256 - This option enables support of hashing using
3252 SHA256 algorithm. The hash is calculated in software.
3253 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3254 for SHA1/SHA256 hashing.
3255 This affects the 'hash' command and also the
3256 hash_lookup_algo() function.
3257 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3258 hardware-acceleration for SHA1/SHA256 progressive hashing.
3259 Data can be streamed in a block at a time and the hashing
3260 is performed in hardware.
3262 Note: There is also a sha1sum command, which should perhaps
3263 be deprecated in favour of 'hash sha1'.
3265 - Freescale i.MX specific commands:
3266 CONFIG_CMD_HDMIDETECT
3267 This enables 'hdmidet' command which returns true if an
3268 HDMI monitor is detected. This command is i.MX 6 specific.
3271 This enables the 'bmode' (bootmode) command for forcing
3272 a boot from specific media.
3274 This is useful for forcing the ROM's usb downloader to
3275 activate upon a watchdog reset which is nice when iterating
3276 on U-Boot. Using the reset button or running bmode normal
3277 will set it back to normal. This command currently
3278 supports i.MX53 and i.MX6.
3283 This enables the RSA algorithm used for FIT image verification
3284 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3286 The Modular Exponentiation algorithm in RSA is implemented using
3287 driver model. So CONFIG_DM needs to be enabled by default for this
3288 library to function.
3290 The signing part is build into mkimage regardless of this
3291 option. The software based modular exponentiation is built into
3292 mkimage irrespective of this option.
3294 - bootcount support:
3295 CONFIG_BOOTCOUNT_LIMIT
3297 This enables the bootcounter support, see:
3298 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3301 enable special bootcounter support on at91sam9xe based boards.
3303 enable special bootcounter support on blackfin based boards.
3305 enable special bootcounter support on da850 based boards.
3306 CONFIG_BOOTCOUNT_RAM
3307 enable support for the bootcounter in RAM
3308 CONFIG_BOOTCOUNT_I2C
3309 enable support for the bootcounter on an i2c (like RTC) device.
3310 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3311 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3313 CONFIG_BOOTCOUNT_ALEN = address len
3315 - Show boot progress:
3316 CONFIG_SHOW_BOOT_PROGRESS
3318 Defining this option allows to add some board-
3319 specific code (calling a user-provided function
3320 "show_boot_progress(int)") that enables you to show
3321 the system's boot progress on some display (for
3322 example, some LED's) on your board. At the moment,
3323 the following checkpoints are implemented:
3326 Legacy uImage format:
3329 1 common/cmd_bootm.c before attempting to boot an image
3330 -1 common/cmd_bootm.c Image header has bad magic number
3331 2 common/cmd_bootm.c Image header has correct magic number
3332 -2 common/cmd_bootm.c Image header has bad checksum
3333 3 common/cmd_bootm.c Image header has correct checksum
3334 -3 common/cmd_bootm.c Image data has bad checksum
3335 4 common/cmd_bootm.c Image data has correct checksum
3336 -4 common/cmd_bootm.c Image is for unsupported architecture
3337 5 common/cmd_bootm.c Architecture check OK
3338 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3339 6 common/cmd_bootm.c Image Type check OK
3340 -6 common/cmd_bootm.c gunzip uncompression error
3341 -7 common/cmd_bootm.c Unimplemented compression type
3342 7 common/cmd_bootm.c Uncompression OK
3343 8 common/cmd_bootm.c No uncompress/copy overwrite error
3344 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3346 9 common/image.c Start initial ramdisk verification
3347 -10 common/image.c Ramdisk header has bad magic number
3348 -11 common/image.c Ramdisk header has bad checksum
3349 10 common/image.c Ramdisk header is OK
3350 -12 common/image.c Ramdisk data has bad checksum
3351 11 common/image.c Ramdisk data has correct checksum
3352 12 common/image.c Ramdisk verification complete, start loading
3353 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3354 13 common/image.c Start multifile image verification
3355 14 common/image.c No initial ramdisk, no multifile, continue.
3357 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3359 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3360 -31 post/post.c POST test failed, detected by post_output_backlog()
3361 -32 post/post.c POST test failed, detected by post_run_single()
3363 34 common/cmd_doc.c before loading a Image from a DOC device
3364 -35 common/cmd_doc.c Bad usage of "doc" command
3365 35 common/cmd_doc.c correct usage of "doc" command
3366 -36 common/cmd_doc.c No boot device
3367 36 common/cmd_doc.c correct boot device
3368 -37 common/cmd_doc.c Unknown Chip ID on boot device
3369 37 common/cmd_doc.c correct chip ID found, device available
3370 -38 common/cmd_doc.c Read Error on boot device
3371 38 common/cmd_doc.c reading Image header from DOC device OK
3372 -39 common/cmd_doc.c Image header has bad magic number
3373 39 common/cmd_doc.c Image header has correct magic number
3374 -40 common/cmd_doc.c Error reading Image from DOC device
3375 40 common/cmd_doc.c Image header has correct magic number
3376 41 common/cmd_ide.c before loading a Image from a IDE device
3377 -42 common/cmd_ide.c Bad usage of "ide" command
3378 42 common/cmd_ide.c correct usage of "ide" command
3379 -43 common/cmd_ide.c No boot device
3380 43 common/cmd_ide.c boot device found
3381 -44 common/cmd_ide.c Device not available
3382 44 common/cmd_ide.c Device available
3383 -45 common/cmd_ide.c wrong partition selected
3384 45 common/cmd_ide.c partition selected
3385 -46 common/cmd_ide.c Unknown partition table
3386 46 common/cmd_ide.c valid partition table found
3387 -47 common/cmd_ide.c Invalid partition type
3388 47 common/cmd_ide.c correct partition type
3389 -48 common/cmd_ide.c Error reading Image Header on boot device
3390 48 common/cmd_ide.c reading Image Header from IDE device OK
3391 -49 common/cmd_ide.c Image header has bad magic number
3392 49 common/cmd_ide.c Image header has correct magic number
3393 -50 common/cmd_ide.c Image header has bad checksum
3394 50 common/cmd_ide.c Image header has correct checksum
3395 -51 common/cmd_ide.c Error reading Image from IDE device
3396 51 common/cmd_ide.c reading Image from IDE device OK
3397 52 common/cmd_nand.c before loading a Image from a NAND device
3398 -53 common/cmd_nand.c Bad usage of "nand" command
3399 53 common/cmd_nand.c correct usage of "nand" command
3400 -54 common/cmd_nand.c No boot device
3401 54 common/cmd_nand.c boot device found
3402 -55 common/cmd_nand.c Unknown Chip ID on boot device
3403 55 common/cmd_nand.c correct chip ID found, device available
3404 -56 common/cmd_nand.c Error reading Image Header on boot device
3405 56 common/cmd_nand.c reading Image Header from NAND device OK
3406 -57 common/cmd_nand.c Image header has bad magic number
3407 57 common/cmd_nand.c Image header has correct magic number
3408 -58 common/cmd_nand.c Error reading Image from NAND device
3409 58 common/cmd_nand.c reading Image from NAND device OK
3411 -60 common/env_common.c Environment has a bad CRC, using default
3413 64 net/eth.c starting with Ethernet configuration.
3414 -64 net/eth.c no Ethernet found.
3415 65 net/eth.c Ethernet found.
3417 -80 common/cmd_net.c usage wrong
3418 80 common/cmd_net.c before calling net_loop()
3419 -81 common/cmd_net.c some error in net_loop() occurred
3420 81 common/cmd_net.c net_loop() back without error
3421 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3422 82 common/cmd_net.c trying automatic boot
3423 83 common/cmd_net.c running "source" command
3424 -83 common/cmd_net.c some error in automatic boot or "source" command
3425 84 common/cmd_net.c end without errors
3430 100 common/cmd_bootm.c Kernel FIT Image has correct format
3431 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3432 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3433 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3434 102 common/cmd_bootm.c Kernel unit name specified
3435 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3436 103 common/cmd_bootm.c Found configuration node
3437 104 common/cmd_bootm.c Got kernel subimage node offset
3438 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3439 105 common/cmd_bootm.c Kernel subimage hash verification OK
3440 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3441 106 common/cmd_bootm.c Architecture check OK
3442 -106 common/cmd_bootm.c Kernel subimage has wrong type
3443 107 common/cmd_bootm.c Kernel subimage type OK
3444 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3445 108 common/cmd_bootm.c Got kernel subimage data/size
3446 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3447 -109 common/cmd_bootm.c Can't get kernel subimage type
3448 -110 common/cmd_bootm.c Can't get kernel subimage comp
3449 -111 common/cmd_bootm.c Can't get kernel subimage os
3450 -112 common/cmd_bootm.c Can't get kernel subimage load address
3451 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3453 120 common/image.c Start initial ramdisk verification
3454 -120 common/image.c Ramdisk FIT image has incorrect format
3455 121 common/image.c Ramdisk FIT image has correct format
3456 122 common/image.c No ramdisk subimage unit name, using configuration
3457 -122 common/image.c Can't get configuration for ramdisk subimage
3458 123 common/image.c Ramdisk unit name specified
3459 -124 common/image.c Can't get ramdisk subimage node offset
3460 125 common/image.c Got ramdisk subimage node offset
3461 -125 common/image.c Ramdisk subimage hash verification failed
3462 126 common/image.c Ramdisk subimage hash verification OK
3463 -126 common/image.c Ramdisk subimage for unsupported architecture
3464 127 common/image.c Architecture check OK
3465 -127 common/image.c Can't get ramdisk subimage data/size
3466 128 common/image.c Got ramdisk subimage data/size
3467 129 common/image.c Can't get ramdisk load address
3468 -129 common/image.c Got ramdisk load address
3470 -130 common/cmd_doc.c Incorrect FIT image format
3471 131 common/cmd_doc.c FIT image format OK
3473 -140 common/cmd_ide.c Incorrect FIT image format
3474 141 common/cmd_ide.c FIT image format OK
3476 -150 common/cmd_nand.c Incorrect FIT image format
3477 151 common/cmd_nand.c FIT image format OK
3479 - legacy image format:
3480 CONFIG_IMAGE_FORMAT_LEGACY
3481 enables the legacy image format support in U-Boot.
3484 enabled if CONFIG_FIT_SIGNATURE is not defined.
3486 CONFIG_DISABLE_IMAGE_LEGACY
3487 disable the legacy image format
3489 This define is introduced, as the legacy image format is
3490 enabled per default for backward compatibility.
3492 - FIT image support:
3494 Enable support for the FIT uImage format.
3496 CONFIG_FIT_BEST_MATCH
3497 When no configuration is explicitly selected, default to the
3498 one whose fdt's compatibility field best matches that of
3499 U-Boot itself. A match is considered "best" if it matches the
3500 most specific compatibility entry of U-Boot's fdt's root node.
3501 The order of entries in the configuration's fdt is ignored.
3503 CONFIG_FIT_SIGNATURE
3504 This option enables signature verification of FIT uImages,
3505 using a hash signed and verified using RSA. If
3506 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3507 hashing is available using hardware, RSA library will use it.
3508 See doc/uImage.FIT/signature.txt for more details.
3510 WARNING: When relying on signed FIT images with required
3511 signature check the legacy image format is default
3512 disabled. If a board need legacy image format support
3513 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3515 CONFIG_FIT_DISABLE_SHA256
3516 Supporting SHA256 hashes has quite an impact on binary size.
3517 For constrained systems sha256 hash support can be disabled
3520 - Standalone program support:
3521 CONFIG_STANDALONE_LOAD_ADDR
3523 This option defines a board specific value for the
3524 address where standalone program gets loaded, thus
3525 overwriting the architecture dependent default
3528 - Frame Buffer Address:
3531 Define CONFIG_FB_ADDR if you want to use specific
3532 address for frame buffer. This is typically the case
3533 when using a graphics controller has separate video
3534 memory. U-Boot will then place the frame buffer at
3535 the given address instead of dynamically reserving it
3536 in system RAM by calling lcd_setmem(), which grabs
3537 the memory for the frame buffer depending on the
3538 configured panel size.
3540 Please see board_init_f function.
3542 - Automatic software updates via TFTP server
3544 CONFIG_UPDATE_TFTP_CNT_MAX
3545 CONFIG_UPDATE_TFTP_MSEC_MAX
3547 These options enable and control the auto-update feature;
3548 for a more detailed description refer to doc/README.update.
3550 - MTD Support (mtdparts command, UBI support)
3553 Adds the MTD device infrastructure from the Linux kernel.
3554 Needed for mtdparts command support.
3556 CONFIG_MTD_PARTITIONS
3558 Adds the MTD partitioning infrastructure from the Linux
3559 kernel. Needed for UBI support.
3564 Adds commands for interacting with MTD partitions formatted
3565 with the UBI flash translation layer
3567 Requires also defining CONFIG_RBTREE
3569 CONFIG_UBI_SILENCE_MSG
3571 Make the verbose messages from UBI stop printing. This leaves
3572 warnings and errors enabled.
3575 CONFIG_MTD_UBI_WL_THRESHOLD
3576 This parameter defines the maximum difference between the highest
3577 erase counter value and the lowest erase counter value of eraseblocks
3578 of UBI devices. When this threshold is exceeded, UBI starts performing
3579 wear leveling by means of moving data from eraseblock with low erase
3580 counter to eraseblocks with high erase counter.
3582 The default value should be OK for SLC NAND flashes, NOR flashes and
3583 other flashes which have eraseblock life-cycle 100000 or more.
3584 However, in case of MLC NAND flashes which typically have eraseblock
3585 life-cycle less than 10000, the threshold should be lessened (e.g.,
3586 to 128 or 256, although it does not have to be power of 2).
3590 CONFIG_MTD_UBI_BEB_LIMIT
3591 This option specifies the maximum bad physical eraseblocks UBI
3592 expects on the MTD device (per 1024 eraseblocks). If the
3593 underlying flash does not admit of bad eraseblocks (e.g. NOR
3594 flash), this value is ignored.
3596 NAND datasheets often specify the minimum and maximum NVM
3597 (Number of Valid Blocks) for the flashes' endurance lifetime.
3598 The maximum expected bad eraseblocks per 1024 eraseblocks
3599 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3600 which gives 20 for most NANDs (MaxNVB is basically the total
3601 count of eraseblocks on the chip).
3603 To put it differently, if this value is 20, UBI will try to
3604 reserve about 1.9% of physical eraseblocks for bad blocks
3605 handling. And that will be 1.9% of eraseblocks on the entire
3606 NAND chip, not just the MTD partition UBI attaches. This means
3607 that if you have, say, a NAND flash chip admits maximum 40 bad
3608 eraseblocks, and it is split on two MTD partitions of the same
3609 size, UBI will reserve 40 eraseblocks when attaching a
3614 CONFIG_MTD_UBI_FASTMAP
3615 Fastmap is a mechanism which allows attaching an UBI device
3616 in nearly constant time. Instead of scanning the whole MTD device it
3617 only has to locate a checkpoint (called fastmap) on the device.
3618 The on-flash fastmap contains all information needed to attach
3619 the device. Using fastmap makes only sense on large devices where
3620 attaching by scanning takes long. UBI will not automatically install
3621 a fastmap on old images, but you can set the UBI parameter
3622 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3623 that fastmap-enabled images are still usable with UBI implementations
3624 without fastmap support. On typical flash devices the whole fastmap
3625 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3627 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3628 Set this parameter to enable fastmap automatically on images
3635 Adds commands for interacting with UBI volumes formatted as
3636 UBIFS. UBIFS is read-only in u-boot.
3638 Requires UBI support as well as CONFIG_LZO
3640 CONFIG_UBIFS_SILENCE_MSG
3642 Make the verbose messages from UBIFS stop printing. This leaves
3643 warnings and errors enabled.
3647 Enable building of SPL globally.
3650 LDSCRIPT for linking the SPL binary.
3652 CONFIG_SPL_MAX_FOOTPRINT
3653 Maximum size in memory allocated to the SPL, BSS included.
3654 When defined, the linker checks that the actual memory
3655 used by SPL from _start to __bss_end does not exceed it.
3656 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3657 must not be both defined at the same time.
3660 Maximum size of the SPL image (text, data, rodata, and
3661 linker lists sections), BSS excluded.
3662 When defined, the linker checks that the actual size does
3665 CONFIG_SPL_TEXT_BASE
3666 TEXT_BASE for linking the SPL binary.
3668 CONFIG_SPL_RELOC_TEXT_BASE
3669 Address to relocate to. If unspecified, this is equal to
3670 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3672 CONFIG_SPL_BSS_START_ADDR
3673 Link address for the BSS within the SPL binary.
3675 CONFIG_SPL_BSS_MAX_SIZE
3676 Maximum size in memory allocated to the SPL BSS.
3677 When defined, the linker checks that the actual memory used
3678 by SPL from __bss_start to __bss_end does not exceed it.
3679 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3680 must not be both defined at the same time.
3683 Adress of the start of the stack SPL will use
3685 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3686 When defined, SPL will panic() if the image it has
3687 loaded does not have a signature.
3688 Defining this is useful when code which loads images
3689 in SPL cannot guarantee that absolutely all read errors
3691 An example is the LPC32XX MLC NAND driver, which will
3692 consider that a completely unreadable NAND block is bad,
3693 and thus should be skipped silently.
3695 CONFIG_SPL_RELOC_STACK
3696 Adress of the start of the stack SPL will use after
3697 relocation. If unspecified, this is equal to
3700 CONFIG_SYS_SPL_MALLOC_START
3701 Starting address of the malloc pool used in SPL.
3703 CONFIG_SYS_SPL_MALLOC_SIZE
3704 The size of the malloc pool used in SPL.
3706 CONFIG_SPL_FRAMEWORK
3707 Enable the SPL framework under common/. This framework
3708 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3709 NAND loading of the Linux Kernel.
3712 Enable booting directly to an OS from SPL.
3713 See also: doc/README.falcon
3715 CONFIG_SPL_DISPLAY_PRINT
3716 For ARM, enable an optional function to print more information
3717 about the running system.
3719 CONFIG_SPL_INIT_MINIMAL
3720 Arch init code should be built for a very small image
3722 CONFIG_SPL_LIBCOMMON_SUPPORT
3723 Support for common/libcommon.o in SPL binary
3725 CONFIG_SPL_LIBDISK_SUPPORT
3726 Support for disk/libdisk.o in SPL binary
3728 CONFIG_SPL_I2C_SUPPORT
3729 Support for drivers/i2c/libi2c.o in SPL binary
3731 CONFIG_SPL_GPIO_SUPPORT
3732 Support for drivers/gpio/libgpio.o in SPL binary
3734 CONFIG_SPL_MMC_SUPPORT
3735 Support for drivers/mmc/libmmc.o in SPL binary
3737 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3738 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3739 Address and partition on the MMC to load U-Boot from
3740 when the MMC is being used in raw mode.
3742 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3743 Partition on the MMC to load U-Boot from when the MMC is being
3746 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3747 Sector to load kernel uImage from when MMC is being
3748 used in raw mode (for Falcon mode)
3750 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3751 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3752 Sector and number of sectors to load kernel argument
3753 parameters from when MMC is being used in raw mode
3756 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3757 Partition on the MMC to load U-Boot from when the MMC is being
3760 CONFIG_SPL_FAT_SUPPORT
3761 Support for fs/fat/libfat.o in SPL binary
3763 CONFIG_SPL_EXT_SUPPORT
3764 Support for EXT filesystem in SPL binary
3766 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3767 Filename to read to load U-Boot when reading from filesystem
3769 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3770 Filename to read to load kernel uImage when reading
3771 from filesystem (for Falcon mode)
3773 CONFIG_SPL_FS_LOAD_ARGS_NAME
3774 Filename to read to load kernel argument parameters
3775 when reading from filesystem (for Falcon mode)
3777 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3778 Set this for NAND SPL on PPC mpc83xx targets, so that
3779 start.S waits for the rest of the SPL to load before
3780 continuing (the hardware starts execution after just
3781 loading the first page rather than the full 4K).
3783 CONFIG_SPL_SKIP_RELOCATE
3784 Avoid SPL relocation
3786 CONFIG_SPL_NAND_BASE
3787 Include nand_base.c in the SPL. Requires
3788 CONFIG_SPL_NAND_DRIVERS.
3790 CONFIG_SPL_NAND_DRIVERS
3791 SPL uses normal NAND drivers, not minimal drivers.
3794 Include standard software ECC in the SPL
3796 CONFIG_SPL_NAND_SIMPLE
3797 Support for NAND boot using simple NAND drivers that
3798 expose the cmd_ctrl() interface.
3800 CONFIG_SPL_MTD_SUPPORT
3801 Support for the MTD subsystem within SPL. Useful for
3802 environment on NAND support within SPL.
3804 CONFIG_SPL_NAND_RAW_ONLY
3805 Support to boot only raw u-boot.bin images. Use this only
3806 if you need to save space.
3808 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3809 Set for the SPL on PPC mpc8xxx targets, support for
3810 drivers/ddr/fsl/libddr.o in SPL binary.
3812 CONFIG_SPL_COMMON_INIT_DDR
3813 Set for common ddr init with serial presence detect in
3816 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3817 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3818 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3819 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3820 CONFIG_SYS_NAND_ECCBYTES
3821 Defines the size and behavior of the NAND that SPL uses
3824 CONFIG_SPL_NAND_BOOT
3825 Add support NAND boot
3827 CONFIG_SYS_NAND_U_BOOT_OFFS
3828 Location in NAND to read U-Boot from
3830 CONFIG_SYS_NAND_U_BOOT_DST
3831 Location in memory to load U-Boot to
3833 CONFIG_SYS_NAND_U_BOOT_SIZE
3834 Size of image to load
3836 CONFIG_SYS_NAND_U_BOOT_START
3837 Entry point in loaded image to jump to
3839 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3840 Define this if you need to first read the OOB and then the
3841 data. This is used, for example, on davinci platforms.
3843 CONFIG_SPL_OMAP3_ID_NAND
3844 Support for an OMAP3-specific set of functions to return the
3845 ID and MFR of the first attached NAND chip, if present.
3847 CONFIG_SPL_SERIAL_SUPPORT
3848 Support for drivers/serial/libserial.o in SPL binary
3850 CONFIG_SPL_SPI_FLASH_SUPPORT
3851 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3853 CONFIG_SPL_SPI_SUPPORT
3854 Support for drivers/spi/libspi.o in SPL binary
3856 CONFIG_SPL_RAM_DEVICE
3857 Support for running image already present in ram, in SPL binary
3859 CONFIG_SPL_LIBGENERIC_SUPPORT
3860 Support for lib/libgeneric.o in SPL binary
3862 CONFIG_SPL_ENV_SUPPORT
3863 Support for the environment operating in SPL binary
3865 CONFIG_SPL_NET_SUPPORT
3866 Support for the net/libnet.o in SPL binary.
3867 It conflicts with SPL env from storage medium specified by
3868 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3871 Image offset to which the SPL should be padded before appending
3872 the SPL payload. By default, this is defined as
3873 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3874 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3875 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3878 Final target image containing SPL and payload. Some SPLs
3879 use an arch-specific makefile fragment instead, for
3880 example if more than one image needs to be produced.
3882 CONFIG_FIT_SPL_PRINT
3883 Printing information about a FIT image adds quite a bit of
3884 code to SPL. So this is normally disabled in SPL. Use this
3885 option to re-enable it. This will affect the output of the
3886 bootm command when booting a FIT image.
3890 Enable building of TPL globally.
3893 Image offset to which the TPL should be padded before appending
3894 the TPL payload. By default, this is defined as
3895 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3896 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3897 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3902 [so far only for SMDK2400 boards]
3904 - Modem support enable:
3905 CONFIG_MODEM_SUPPORT
3907 - RTS/CTS Flow control enable:
3910 - Modem debug support:
3911 CONFIG_MODEM_SUPPORT_DEBUG
3913 Enables debugging stuff (char screen[1024], dbg())
3914 for modem support. Useful only with BDI2000.
3916 - Interrupt support (PPC):
3918 There are common interrupt_init() and timer_interrupt()
3919 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3920 for CPU specific initialization. interrupt_init_cpu()
3921 should set decrementer_count to appropriate value. If
3922 CPU resets decrementer automatically after interrupt
3923 (ppc4xx) it should set decrementer_count to zero.
3924 timer_interrupt() calls timer_interrupt_cpu() for CPU
3925 specific handling. If board has watchdog / status_led
3926 / other_activity_monitor it works automatically from
3927 general timer_interrupt().
3931 In the target system modem support is enabled when a
3932 specific key (key combination) is pressed during
3933 power-on. Otherwise U-Boot will boot normally
3934 (autoboot). The key_pressed() function is called from
3935 board_init(). Currently key_pressed() is a dummy
3936 function, returning 1 and thus enabling modem
3939 If there are no modem init strings in the
3940 environment, U-Boot proceed to autoboot; the
3941 previous output (banner, info printfs) will be
3944 See also: doc/README.Modem
3946 Board initialization settings:
3947 ------------------------------
3949 During Initialization u-boot calls a number of board specific functions
3950 to allow the preparation of board specific prerequisites, e.g. pin setup
3951 before drivers are initialized. To enable these callbacks the
3952 following configuration macros have to be defined. Currently this is
3953 architecture specific, so please check arch/your_architecture/lib/board.c
3954 typically in board_init_f() and board_init_r().
3956 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3957 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3958 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3959 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3961 Configuration Settings:
3962 -----------------------
3964 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3965 Optionally it can be defined to support 64-bit memory commands.
3967 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3968 undefine this when you're short of memory.
3970 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3971 width of the commands listed in the 'help' command output.
3973 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3974 prompt for user input.
3976 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3978 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3980 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3982 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3983 the application (usually a Linux kernel) when it is
3986 - CONFIG_SYS_BAUDRATE_TABLE:
3987 List of legal baudrate settings for this board.
3989 - CONFIG_SYS_CONSOLE_INFO_QUIET
3990 Suppress display of console information at boot.
3992 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3993 If the board specific function
3994 extern int overwrite_console (void);
3995 returns 1, the stdin, stderr and stdout are switched to the
3996 serial port, else the settings in the environment are used.
3998 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3999 Enable the call to overwrite_console().
4001 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4002 Enable overwrite of previous console environment settings.
4004 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4005 Begin and End addresses of the area used by the
4008 - CONFIG_SYS_ALT_MEMTEST:
4009 Enable an alternate, more extensive memory test.
4011 - CONFIG_SYS_MEMTEST_SCRATCH:
4012 Scratch address used by the alternate memory test
4013 You only need to set this if address zero isn't writeable
4015 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4016 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4017 this specified memory area will get subtracted from the top
4018 (end) of RAM and won't get "touched" at all by U-Boot. By
4019 fixing up gd->ram_size the Linux kernel should gets passed
4020 the now "corrected" memory size and won't touch it either.
4021 This should work for arch/ppc and arch/powerpc. Only Linux
4022 board ports in arch/powerpc with bootwrapper support that
4023 recalculate the memory size from the SDRAM controller setup
4024 will have to get fixed in Linux additionally.
4026 This option can be used as a workaround for the 440EPx/GRx
4027 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4030 WARNING: Please make sure that this value is a multiple of
4031 the Linux page size (normally 4k). If this is not the case,
4032 then the end address of the Linux memory will be located at a
4033 non page size aligned address and this could cause major
4036 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4037 Enable temporary baudrate change while serial download
4039 - CONFIG_SYS_SDRAM_BASE:
4040 Physical start address of SDRAM. _Must_ be 0 here.
4042 - CONFIG_SYS_MBIO_BASE:
4043 Physical start address of Motherboard I/O (if using a
4046 - CONFIG_SYS_FLASH_BASE:
4047 Physical start address of Flash memory.
4049 - CONFIG_SYS_MONITOR_BASE:
4050 Physical start address of boot monitor code (set by
4051 make config files to be same as the text base address
4052 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4053 CONFIG_SYS_FLASH_BASE when booting from flash.
4055 - CONFIG_SYS_MONITOR_LEN:
4056 Size of memory reserved for monitor code, used to
4057 determine _at_compile_time_ (!) if the environment is
4058 embedded within the U-Boot image, or in a separate
4061 - CONFIG_SYS_MALLOC_LEN:
4062 Size of DRAM reserved for malloc() use.
4064 - CONFIG_SYS_MALLOC_F_LEN
4065 Size of the malloc() pool for use before relocation. If
4066 this is defined, then a very simple malloc() implementation
4067 will become available before relocation. The address is just
4068 below the global data, and the stack is moved down to make
4071 This feature allocates regions with increasing addresses
4072 within the region. calloc() is supported, but realloc()
4073 is not available. free() is supported but does nothing.
4074 The memory will be freed (or in fact just forgotten) when
4075 U-Boot relocates itself.
4077 Pre-relocation malloc() is only supported on ARM and sandbox
4078 at present but is fairly easy to enable for other archs.
4080 - CONFIG_SYS_MALLOC_SIMPLE
4081 Provides a simple and small malloc() and calloc() for those
4082 boards which do not use the full malloc in SPL (which is
4083 enabled with CONFIG_SYS_SPL_MALLOC_START).
4085 - CONFIG_SYS_NONCACHED_MEMORY:
4086 Size of non-cached memory area. This area of memory will be
4087 typically located right below the malloc() area and mapped
4088 uncached in the MMU. This is useful for drivers that would
4089 otherwise require a lot of explicit cache maintenance. For
4090 some drivers it's also impossible to properly maintain the
4091 cache. For example if the regions that need to be flushed
4092 are not a multiple of the cache-line size, *and* padding
4093 cannot be allocated between the regions to align them (i.e.
4094 if the HW requires a contiguous array of regions, and the
4095 size of each region is not cache-aligned), then a flush of
4096 one region may result in overwriting data that hardware has
4097 written to another region in the same cache-line. This can
4098 happen for example in network drivers where descriptors for
4099 buffers are typically smaller than the CPU cache-line (e.g.
4100 16 bytes vs. 32 or 64 bytes).
4102 Non-cached memory is only supported on 32-bit ARM at present.
4104 - CONFIG_SYS_BOOTM_LEN:
4105 Normally compressed uImages are limited to an
4106 uncompressed size of 8 MBytes. If this is not enough,
4107 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4108 to adjust this setting to your needs.
4110 - CONFIG_SYS_BOOTMAPSZ:
4111 Maximum size of memory mapped by the startup code of
4112 the Linux kernel; all data that must be processed by
4113 the Linux kernel (bd_info, boot arguments, FDT blob if
4114 used) must be put below this limit, unless "bootm_low"
4115 environment variable is defined and non-zero. In such case
4116 all data for the Linux kernel must be between "bootm_low"
4117 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4118 variable "bootm_mapsize" will override the value of
4119 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4120 then the value in "bootm_size" will be used instead.
4122 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4123 Enable initrd_high functionality. If defined then the
4124 initrd_high feature is enabled and the bootm ramdisk subcommand
4127 - CONFIG_SYS_BOOT_GET_CMDLINE:
4128 Enables allocating and saving kernel cmdline in space between
4129 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4131 - CONFIG_SYS_BOOT_GET_KBD:
4132 Enables allocating and saving a kernel copy of the bd_info in
4133 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4135 - CONFIG_SYS_MAX_FLASH_BANKS:
4136 Max number of Flash memory banks
4138 - CONFIG_SYS_MAX_FLASH_SECT:
4139 Max number of sectors on a Flash chip
4141 - CONFIG_SYS_FLASH_ERASE_TOUT:
4142 Timeout for Flash erase operations (in ms)
4144 - CONFIG_SYS_FLASH_WRITE_TOUT:
4145 Timeout for Flash write operations (in ms)
4147 - CONFIG_SYS_FLASH_LOCK_TOUT
4148 Timeout for Flash set sector lock bit operation (in ms)
4150 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4151 Timeout for Flash clear lock bits operation (in ms)
4153 - CONFIG_SYS_FLASH_PROTECTION
4154 If defined, hardware flash sectors protection is used
4155 instead of U-Boot software protection.
4157 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4159 Enable TFTP transfers directly to flash memory;
4160 without this option such a download has to be
4161 performed in two steps: (1) download to RAM, and (2)
4162 copy from RAM to flash.
4164 The two-step approach is usually more reliable, since
4165 you can check if the download worked before you erase
4166 the flash, but in some situations (when system RAM is
4167 too limited to allow for a temporary copy of the
4168 downloaded image) this option may be very useful.
4170 - CONFIG_SYS_FLASH_CFI:
4171 Define if the flash driver uses extra elements in the
4172 common flash structure for storing flash geometry.
4174 - CONFIG_FLASH_CFI_DRIVER
4175 This option also enables the building of the cfi_flash driver
4176 in the drivers directory
4178 - CONFIG_FLASH_CFI_MTD
4179 This option enables the building of the cfi_mtd driver
4180 in the drivers directory. The driver exports CFI flash
4183 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4184 Use buffered writes to flash.
4186 - CONFIG_FLASH_SPANSION_S29WS_N
4187 s29ws-n MirrorBit flash has non-standard addresses for buffered
4190 - CONFIG_SYS_FLASH_QUIET_TEST
4191 If this option is defined, the common CFI flash doesn't
4192 print it's warning upon not recognized FLASH banks. This
4193 is useful, if some of the configured banks are only
4194 optionally available.
4196 - CONFIG_FLASH_SHOW_PROGRESS
4197 If defined (must be an integer), print out countdown
4198 digits and dots. Recommended value: 45 (9..1) for 80
4199 column displays, 15 (3..1) for 40 column displays.
4201 - CONFIG_FLASH_VERIFY
4202 If defined, the content of the flash (destination) is compared
4203 against the source after the write operation. An error message
4204 will be printed when the contents are not identical.
4205 Please note that this option is useless in nearly all cases,
4206 since such flash programming errors usually are detected earlier
4207 while unprotecting/erasing/programming. Please only enable
4208 this option if you really know what you are doing.
4210 - CONFIG_SYS_RX_ETH_BUFFER:
4211 Defines the number of Ethernet receive buffers. On some
4212 Ethernet controllers it is recommended to set this value
4213 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4214 buffers can be full shortly after enabling the interface
4215 on high Ethernet traffic.
4216 Defaults to 4 if not defined.
4218 - CONFIG_ENV_MAX_ENTRIES
4220 Maximum number of entries in the hash table that is used
4221 internally to store the environment settings. The default
4222 setting is supposed to be generous and should work in most
4223 cases. This setting can be used to tune behaviour; see
4224 lib/hashtable.c for details.
4226 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4227 - CONFIG_ENV_FLAGS_LIST_STATIC
4228 Enable validation of the values given to environment variables when
4229 calling env set. Variables can be restricted to only decimal,
4230 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4231 the variables can also be restricted to IP address or MAC address.
4233 The format of the list is:
4234 type_attribute = [s|d|x|b|i|m]
4235 access_attribute = [a|r|o|c]
4236 attributes = type_attribute[access_attribute]
4237 entry = variable_name[:attributes]
4240 The type attributes are:
4241 s - String (default)
4244 b - Boolean ([1yYtT|0nNfF])
4248 The access attributes are:
4254 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4255 Define this to a list (string) to define the ".flags"
4256 environment variable in the default or embedded environment.
4258 - CONFIG_ENV_FLAGS_LIST_STATIC
4259 Define this to a list (string) to define validation that
4260 should be done if an entry is not found in the ".flags"
4261 environment variable. To override a setting in the static
4262 list, simply add an entry for the same variable name to the
4265 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4266 regular expression. This allows multiple variables to define the same
4267 flags without explicitly listing them for each variable.
4269 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4270 If defined, don't allow the -f switch to env set override variable
4273 - CONFIG_SYS_GENERIC_BOARD
4274 This selects the architecture-generic board system instead of the
4275 architecture-specific board files. It is intended to move boards
4276 to this new framework over time. Defining this will disable the
4277 arch/foo/lib/board.c file and use common/board_f.c and
4278 common/board_r.c instead. To use this option your architecture
4279 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4280 If you find problems enabling this option on your board please report
4281 the problem and send patches!
4283 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4284 This is set by OMAP boards for the max time that reset should
4285 be asserted. See doc/README.omap-reset-time for details on how
4286 the value can be calculated on a given board.
4289 If stdint.h is available with your toolchain you can define this
4290 option to enable it. You can provide option 'USE_STDINT=1' when
4291 building U-Boot to enable this.
4293 The following definitions that deal with the placement and management
4294 of environment data (variable area); in general, we support the
4295 following configurations:
4297 - CONFIG_BUILD_ENVCRC:
4299 Builds up envcrc with the target environment so that external utils
4300 may easily extract it and embed it in final U-Boot images.
4302 - CONFIG_ENV_IS_IN_FLASH:
4304 Define this if the environment is in flash memory.
4306 a) The environment occupies one whole flash sector, which is
4307 "embedded" in the text segment with the U-Boot code. This
4308 happens usually with "bottom boot sector" or "top boot
4309 sector" type flash chips, which have several smaller
4310 sectors at the start or the end. For instance, such a
4311 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4312 such a case you would place the environment in one of the
4313 4 kB sectors - with U-Boot code before and after it. With
4314 "top boot sector" type flash chips, you would put the
4315 environment in one of the last sectors, leaving a gap
4316 between U-Boot and the environment.
4318 - CONFIG_ENV_OFFSET:
4320 Offset of environment data (variable area) to the
4321 beginning of flash memory; for instance, with bottom boot
4322 type flash chips the second sector can be used: the offset
4323 for this sector is given here.
4325 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4329 This is just another way to specify the start address of
4330 the flash sector containing the environment (instead of
4333 - CONFIG_ENV_SECT_SIZE:
4335 Size of the sector containing the environment.
4338 b) Sometimes flash chips have few, equal sized, BIG sectors.
4339 In such a case you don't want to spend a whole sector for
4344 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4345 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4346 of this flash sector for the environment. This saves
4347 memory for the RAM copy of the environment.
4349 It may also save flash memory if you decide to use this
4350 when your environment is "embedded" within U-Boot code,
4351 since then the remainder of the flash sector could be used
4352 for U-Boot code. It should be pointed out that this is
4353 STRONGLY DISCOURAGED from a robustness point of view:
4354 updating the environment in flash makes it always
4355 necessary to erase the WHOLE sector. If something goes
4356 wrong before the contents has been restored from a copy in
4357 RAM, your target system will be dead.
4359 - CONFIG_ENV_ADDR_REDUND
4360 CONFIG_ENV_SIZE_REDUND
4362 These settings describe a second storage area used to hold
4363 a redundant copy of the environment data, so that there is
4364 a valid backup copy in case there is a power failure during
4365 a "saveenv" operation.
4367 BE CAREFUL! Any changes to the flash layout, and some changes to the
4368 source code will make it necessary to adapt <board>/u-boot.lds*
4372 - CONFIG_ENV_IS_IN_NVRAM:
4374 Define this if you have some non-volatile memory device
4375 (NVRAM, battery buffered SRAM) which you want to use for the
4381 These two #defines are used to determine the memory area you
4382 want to use for environment. It is assumed that this memory
4383 can just be read and written to, without any special
4386 BE CAREFUL! The first access to the environment happens quite early
4387 in U-Boot initialization (when we try to get the setting of for the
4388 console baudrate). You *MUST* have mapped your NVRAM area then, or
4391 Please note that even with NVRAM we still use a copy of the
4392 environment in RAM: we could work on NVRAM directly, but we want to
4393 keep settings there always unmodified except somebody uses "saveenv"
4394 to save the current settings.
4397 - CONFIG_ENV_IS_IN_EEPROM:
4399 Use this if you have an EEPROM or similar serial access
4400 device and a driver for it.
4402 - CONFIG_ENV_OFFSET:
4405 These two #defines specify the offset and size of the
4406 environment area within the total memory of your EEPROM.
4408 - CONFIG_SYS_I2C_EEPROM_ADDR:
4409 If defined, specified the chip address of the EEPROM device.
4410 The default address is zero.
4412 - CONFIG_SYS_I2C_EEPROM_BUS:
4413 If defined, specified the i2c bus of the EEPROM device.
4415 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4416 If defined, the number of bits used to address bytes in a
4417 single page in the EEPROM device. A 64 byte page, for example
4418 would require six bits.
4420 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4421 If defined, the number of milliseconds to delay between
4422 page writes. The default is zero milliseconds.
4424 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4425 The length in bytes of the EEPROM memory array address. Note
4426 that this is NOT the chip address length!
4428 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4429 EEPROM chips that implement "address overflow" are ones
4430 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4431 address and the extra bits end up in the "chip address" bit
4432 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4435 Note that we consider the length of the address field to
4436 still be one byte because the extra address bits are hidden
4437 in the chip address.
4439 - CONFIG_SYS_EEPROM_SIZE:
4440 The size in bytes of the EEPROM device.
4442 - CONFIG_ENV_EEPROM_IS_ON_I2C
4443 define this, if you have I2C and SPI activated, and your
4444 EEPROM, which holds the environment, is on the I2C bus.
4446 - CONFIG_I2C_ENV_EEPROM_BUS
4447 if you have an Environment on an EEPROM reached over
4448 I2C muxes, you can define here, how to reach this
4449 EEPROM. For example:
4451 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4453 EEPROM which holds the environment, is reached over
4454 a pca9547 i2c mux with address 0x70, channel 3.
4456 - CONFIG_ENV_IS_IN_DATAFLASH:
4458 Define this if you have a DataFlash memory device which you
4459 want to use for the environment.
4461 - CONFIG_ENV_OFFSET:
4465 These three #defines specify the offset and size of the
4466 environment area within the total memory of your DataFlash placed
4467 at the specified address.
4469 - CONFIG_ENV_IS_IN_SPI_FLASH:
4471 Define this if you have a SPI Flash memory device which you
4472 want to use for the environment.
4474 - CONFIG_ENV_OFFSET:
4477 These two #defines specify the offset and size of the
4478 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4479 aligned to an erase sector boundary.
4481 - CONFIG_ENV_SECT_SIZE:
4483 Define the SPI flash's sector size.
4485 - CONFIG_ENV_OFFSET_REDUND (optional):
4487 This setting describes a second storage area of CONFIG_ENV_SIZE
4488 size used to hold a redundant copy of the environment data, so
4489 that there is a valid backup copy in case there is a power failure
4490 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4491 aligned to an erase sector boundary.
4493 - CONFIG_ENV_SPI_BUS (optional):
4494 - CONFIG_ENV_SPI_CS (optional):
4496 Define the SPI bus and chip select. If not defined they will be 0.
4498 - CONFIG_ENV_SPI_MAX_HZ (optional):
4500 Define the SPI max work clock. If not defined then use 1MHz.
4502 - CONFIG_ENV_SPI_MODE (optional):
4504 Define the SPI work mode. If not defined then use SPI_MODE_3.
4506 - CONFIG_ENV_IS_IN_REMOTE:
4508 Define this if you have a remote memory space which you
4509 want to use for the local device's environment.
4514 These two #defines specify the address and size of the
4515 environment area within the remote memory space. The
4516 local device can get the environment from remote memory
4517 space by SRIO or PCIE links.
4519 BE CAREFUL! For some special cases, the local device can not use
4520 "saveenv" command. For example, the local device will get the
4521 environment stored in a remote NOR flash by SRIO or PCIE link,
4522 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4524 - CONFIG_ENV_IS_IN_NAND:
4526 Define this if you have a NAND device which you want to use
4527 for the environment.
4529 - CONFIG_ENV_OFFSET:
4532 These two #defines specify the offset and size of the environment
4533 area within the first NAND device. CONFIG_ENV_OFFSET must be
4534 aligned to an erase block boundary.
4536 - CONFIG_ENV_OFFSET_REDUND (optional):
4538 This setting describes a second storage area of CONFIG_ENV_SIZE
4539 size used to hold a redundant copy of the environment data, so
4540 that there is a valid backup copy in case there is a power failure
4541 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4542 aligned to an erase block boundary.
4544 - CONFIG_ENV_RANGE (optional):
4546 Specifies the length of the region in which the environment
4547 can be written. This should be a multiple of the NAND device's
4548 block size. Specifying a range with more erase blocks than
4549 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4550 the range to be avoided.
4552 - CONFIG_ENV_OFFSET_OOB (optional):
4554 Enables support for dynamically retrieving the offset of the
4555 environment from block zero's out-of-band data. The
4556 "nand env.oob" command can be used to record this offset.
4557 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4558 using CONFIG_ENV_OFFSET_OOB.
4560 - CONFIG_NAND_ENV_DST
4562 Defines address in RAM to which the nand_spl code should copy the
4563 environment. If redundant environment is used, it will be copied to
4564 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4566 - CONFIG_ENV_IS_IN_UBI:
4568 Define this if you have an UBI volume that you want to use for the
4569 environment. This has the benefit of wear-leveling the environment
4570 accesses, which is important on NAND.
4572 - CONFIG_ENV_UBI_PART:
4574 Define this to a string that is the mtd partition containing the UBI.
4576 - CONFIG_ENV_UBI_VOLUME:
4578 Define this to the name of the volume that you want to store the
4581 - CONFIG_ENV_UBI_VOLUME_REDUND:
4583 Define this to the name of another volume to store a second copy of
4584 the environment in. This will enable redundant environments in UBI.
4585 It is assumed that both volumes are in the same MTD partition.
4587 - CONFIG_UBI_SILENCE_MSG
4588 - CONFIG_UBIFS_SILENCE_MSG
4590 You will probably want to define these to avoid a really noisy system
4591 when storing the env in UBI.
4593 - CONFIG_ENV_IS_IN_FAT:
4594 Define this if you want to use the FAT file system for the environment.
4596 - FAT_ENV_INTERFACE:
4598 Define this to a string that is the name of the block device.
4600 - FAT_ENV_DEV_AND_PART:
4602 Define this to a string to specify the partition of the device. It can
4605 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4606 - "D:P": device D partition P. Error occurs if device D has no
4609 - "D" or "D:": device D partition 1 if device D has partition
4610 table, or the whole device D if has no partition
4612 - "D:auto": first partition in device D with bootable flag set.
4613 If none, first valid partition in device D. If no
4614 partition table then means device D.
4618 It's a string of the FAT file name. This file use to store the
4622 This should be defined. Otherwise it cannot save the environment file.
4624 - CONFIG_ENV_IS_IN_MMC:
4626 Define this if you have an MMC device which you want to use for the
4629 - CONFIG_SYS_MMC_ENV_DEV:
4631 Specifies which MMC device the environment is stored in.
4633 - CONFIG_SYS_MMC_ENV_PART (optional):
4635 Specifies which MMC partition the environment is stored in. If not
4636 set, defaults to partition 0, the user area. Common values might be
4637 1 (first MMC boot partition), 2 (second MMC boot partition).
4639 - CONFIG_ENV_OFFSET:
4642 These two #defines specify the offset and size of the environment
4643 area within the specified MMC device.
4645 If offset is positive (the usual case), it is treated as relative to
4646 the start of the MMC partition. If offset is negative, it is treated
4647 as relative to the end of the MMC partition. This can be useful if
4648 your board may be fitted with different MMC devices, which have
4649 different sizes for the MMC partitions, and you always want the
4650 environment placed at the very end of the partition, to leave the
4651 maximum possible space before it, to store other data.
4653 These two values are in units of bytes, but must be aligned to an
4654 MMC sector boundary.
4656 - CONFIG_ENV_OFFSET_REDUND (optional):
4658 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4659 hold a redundant copy of the environment data. This provides a
4660 valid backup copy in case the other copy is corrupted, e.g. due
4661 to a power failure during a "saveenv" operation.
4663 This value may also be positive or negative; this is handled in the
4664 same way as CONFIG_ENV_OFFSET.
4666 This value is also in units of bytes, but must also be aligned to
4667 an MMC sector boundary.
4669 - CONFIG_ENV_SIZE_REDUND (optional):
4671 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4672 set. If this value is set, it must be set to the same value as
4675 - CONFIG_SYS_SPI_INIT_OFFSET
4677 Defines offset to the initial SPI buffer area in DPRAM. The
4678 area is used at an early stage (ROM part) if the environment
4679 is configured to reside in the SPI EEPROM: We need a 520 byte
4680 scratch DPRAM area. It is used between the two initialization
4681 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4682 to be a good choice since it makes it far enough from the
4683 start of the data area as well as from the stack pointer.
4685 Please note that the environment is read-only until the monitor
4686 has been relocated to RAM and a RAM copy of the environment has been
4687 created; also, when using EEPROM you will have to use getenv_f()
4688 until then to read environment variables.
4690 The environment is protected by a CRC32 checksum. Before the monitor
4691 is relocated into RAM, as a result of a bad CRC you will be working
4692 with the compiled-in default environment - *silently*!!! [This is
4693 necessary, because the first environment variable we need is the
4694 "baudrate" setting for the console - if we have a bad CRC, we don't
4695 have any device yet where we could complain.]
4697 Note: once the monitor has been relocated, then it will complain if
4698 the default environment is used; a new CRC is computed as soon as you
4699 use the "saveenv" command to store a valid environment.
4701 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4702 Echo the inverted Ethernet link state to the fault LED.
4704 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4705 also needs to be defined.
4707 - CONFIG_SYS_FAULT_MII_ADDR:
4708 MII address of the PHY to check for the Ethernet link state.
4710 - CONFIG_NS16550_MIN_FUNCTIONS:
4711 Define this if you desire to only have use of the NS16550_init
4712 and NS16550_putc functions for the serial driver located at
4713 drivers/serial/ns16550.c. This option is useful for saving
4714 space for already greatly restricted images, including but not
4715 limited to NAND_SPL configurations.
4717 - CONFIG_DISPLAY_BOARDINFO
4718 Display information about the board that U-Boot is running on
4719 when U-Boot starts up. The board function checkboard() is called
4722 - CONFIG_DISPLAY_BOARDINFO_LATE
4723 Similar to the previous option, but display this information
4724 later, once stdio is running and output goes to the LCD, if
4727 - CONFIG_BOARD_SIZE_LIMIT:
4728 Maximum size of the U-Boot image. When defined, the
4729 build system checks that the actual size does not
4732 Low Level (hardware related) configuration options:
4733 ---------------------------------------------------
4735 - CONFIG_SYS_CACHELINE_SIZE:
4736 Cache Line Size of the CPU.
4738 - CONFIG_SYS_DEFAULT_IMMR:
4739 Default address of the IMMR after system reset.
4741 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4742 and RPXsuper) to be able to adjust the position of
4743 the IMMR register after a reset.
4745 - CONFIG_SYS_CCSRBAR_DEFAULT:
4746 Default (power-on reset) physical address of CCSR on Freescale
4749 - CONFIG_SYS_CCSRBAR:
4750 Virtual address of CCSR. On a 32-bit build, this is typically
4751 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4753 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4754 for cross-platform code that uses that macro instead.
4756 - CONFIG_SYS_CCSRBAR_PHYS:
4757 Physical address of CCSR. CCSR can be relocated to a new
4758 physical address, if desired. In this case, this macro should
4759 be set to that address. Otherwise, it should be set to the
4760 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4761 is typically relocated on 36-bit builds. It is recommended
4762 that this macro be defined via the _HIGH and _LOW macros:
4764 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4765 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4767 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4768 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4769 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4770 used in assembly code, so it must not contain typecasts or
4771 integer size suffixes (e.g. "ULL").
4773 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4774 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4775 used in assembly code, so it must not contain typecasts or
4776 integer size suffixes (e.g. "ULL").
4778 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4779 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4780 forced to a value that ensures that CCSR is not relocated.
4782 - Floppy Disk Support:
4783 CONFIG_SYS_FDC_DRIVE_NUMBER
4785 the default drive number (default value 0)
4787 CONFIG_SYS_ISA_IO_STRIDE
4789 defines the spacing between FDC chipset registers
4792 CONFIG_SYS_ISA_IO_OFFSET
4794 defines the offset of register from address. It
4795 depends on which part of the data bus is connected to
4796 the FDC chipset. (default value 0)
4798 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4799 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4802 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4803 fdc_hw_init() is called at the beginning of the FDC
4804 setup. fdc_hw_init() must be provided by the board
4805 source code. It is used to make hardware-dependent
4809 Most IDE controllers were designed to be connected with PCI
4810 interface. Only few of them were designed for AHB interface.
4811 When software is doing ATA command and data transfer to
4812 IDE devices through IDE-AHB controller, some additional
4813 registers accessing to these kind of IDE-AHB controller
4816 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4817 DO NOT CHANGE unless you know exactly what you're
4818 doing! (11-4) [MPC8xx/82xx systems only]
4820 - CONFIG_SYS_INIT_RAM_ADDR:
4822 Start address of memory area that can be used for
4823 initial data and stack; please note that this must be
4824 writable memory that is working WITHOUT special
4825 initialization, i. e. you CANNOT use normal RAM which
4826 will become available only after programming the
4827 memory controller and running certain initialization
4830 U-Boot uses the following memory types:
4831 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4832 - MPC824X: data cache
4833 - PPC4xx: data cache
4835 - CONFIG_SYS_GBL_DATA_OFFSET:
4837 Offset of the initial data structure in the memory
4838 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4839 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4840 data is located at the end of the available space
4841 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4842 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4843 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4844 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4847 On the MPC824X (or other systems that use the data
4848 cache for initial memory) the address chosen for
4849 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4850 point to an otherwise UNUSED address space between
4851 the top of RAM and the start of the PCI space.
4853 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4855 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4857 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4859 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4861 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4863 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4865 - CONFIG_SYS_OR_TIMING_SDRAM:
4868 - CONFIG_SYS_MAMR_PTA:
4869 periodic timer for refresh
4871 - CONFIG_SYS_DER: Debug Event Register (37-47)
4873 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4874 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4875 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4876 CONFIG_SYS_BR1_PRELIM:
4877 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4879 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4880 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4881 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4882 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4884 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4885 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4886 Machine Mode Register and Memory Periodic Timer
4887 Prescaler definitions (SDRAM timing)
4889 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4890 enable I2C microcode relocation patch (MPC8xx);
4891 define relocation offset in DPRAM [DSP2]
4893 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4894 enable SMC microcode relocation patch (MPC8xx);
4895 define relocation offset in DPRAM [SMC1]
4897 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4898 enable SPI microcode relocation patch (MPC8xx);
4899 define relocation offset in DPRAM [SCC4]
4901 - CONFIG_SYS_USE_OSCCLK:
4902 Use OSCM clock mode on MBX8xx board. Be careful,
4903 wrong setting might damage your board. Read
4904 doc/README.MBX before setting this variable!
4906 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4907 Offset of the bootmode word in DPRAM used by post
4908 (Power On Self Tests). This definition overrides
4909 #define'd default value in commproc.h resp.
4912 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4913 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4914 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4915 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4916 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4917 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4918 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4919 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4920 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4922 - CONFIG_PCI_DISABLE_PCIE:
4923 Disable PCI-Express on systems where it is supported but not
4926 - CONFIG_PCI_ENUM_ONLY
4927 Only scan through and get the devices on the buses.
4928 Don't do any setup work, presumably because someone or
4929 something has already done it, and we don't need to do it
4930 a second time. Useful for platforms that are pre-booted
4931 by coreboot or similar.
4933 - CONFIG_PCI_INDIRECT_BRIDGE:
4934 Enable support for indirect PCI bridges.
4937 Chip has SRIO or not
4940 Board has SRIO 1 port available
4943 Board has SRIO 2 port available
4945 - CONFIG_SRIO_PCIE_BOOT_MASTER
4946 Board can support master function for Boot from SRIO and PCIE
4948 - CONFIG_SYS_SRIOn_MEM_VIRT:
4949 Virtual Address of SRIO port 'n' memory region
4951 - CONFIG_SYS_SRIOn_MEM_PHYS:
4952 Physical Address of SRIO port 'n' memory region
4954 - CONFIG_SYS_SRIOn_MEM_SIZE:
4955 Size of SRIO port 'n' memory region
4957 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4958 Defined to tell the NAND controller that the NAND chip is using
4960 Not all NAND drivers use this symbol.
4961 Example of drivers that use it:
4962 - drivers/mtd/nand/ndfc.c
4963 - drivers/mtd/nand/mxc_nand.c
4965 - CONFIG_SYS_NDFC_EBC0_CFG
4966 Sets the EBC0_CFG register for the NDFC. If not defined
4967 a default value will be used.
4970 Get DDR timing information from an I2C EEPROM. Common
4971 with pluggable memory modules such as SODIMMs
4974 I2C address of the SPD EEPROM
4976 - CONFIG_SYS_SPD_BUS_NUM
4977 If SPD EEPROM is on an I2C bus other than the first
4978 one, specify here. Note that the value must resolve
4979 to something your driver can deal with.
4981 - CONFIG_SYS_DDR_RAW_TIMING
4982 Get DDR timing information from other than SPD. Common with
4983 soldered DDR chips onboard without SPD. DDR raw timing
4984 parameters are extracted from datasheet and hard-coded into
4985 header files or board specific files.
4987 - CONFIG_FSL_DDR_INTERACTIVE
4988 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4990 - CONFIG_FSL_DDR_SYNC_REFRESH
4991 Enable sync of refresh for multiple controllers.
4993 - CONFIG_FSL_DDR_BIST
4994 Enable built-in memory test for Freescale DDR controllers.
4996 - CONFIG_SYS_83XX_DDR_USES_CS0
4997 Only for 83xx systems. If specified, then DDR should
4998 be configured using CS0 and CS1 instead of CS2 and CS3.
5000 - CONFIG_ETHER_ON_FEC[12]
5001 Define to enable FEC[12] on a 8xx series processor.
5003 - CONFIG_FEC[12]_PHY
5004 Define to the hardcoded PHY address which corresponds
5005 to the given FEC; i. e.
5006 #define CONFIG_FEC1_PHY 4
5007 means that the PHY with address 4 is connected to FEC1
5009 When set to -1, means to probe for first available.
5011 - CONFIG_FEC[12]_PHY_NORXERR
5012 The PHY does not have a RXERR line (RMII only).
5013 (so program the FEC to ignore it).
5016 Enable RMII mode for all FECs.
5017 Note that this is a global option, we can't
5018 have one FEC in standard MII mode and another in RMII mode.
5020 - CONFIG_CRC32_VERIFY
5021 Add a verify option to the crc32 command.
5024 => crc32 -v <address> <count> <crc32>
5026 Where address/count indicate a memory area
5027 and crc32 is the correct crc32 which the
5031 Add the "loopw" memory command. This only takes effect if
5032 the memory commands are activated globally (CONFIG_CMD_MEM).
5035 Add the "mdc" and "mwc" memory commands. These are cyclic
5040 This command will print 4 bytes (10,11,12,13) each 500 ms.
5042 => mwc.l 100 12345678 10
5043 This command will write 12345678 to address 100 all 10 ms.
5045 This only takes effect if the memory commands are activated
5046 globally (CONFIG_CMD_MEM).
5048 - CONFIG_SKIP_LOWLEVEL_INIT
5049 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5050 low level initializations (like setting up the memory
5051 controller) are omitted and/or U-Boot does not
5052 relocate itself into RAM.
5054 Normally this variable MUST NOT be defined. The only
5055 exception is when U-Boot is loaded (to RAM) by some
5056 other boot loader or by a debugger which performs
5057 these initializations itself.
5060 Modifies the behaviour of start.S when compiling a loader
5061 that is executed before the actual U-Boot. E.g. when
5062 compiling a NAND SPL.
5065 Modifies the behaviour of start.S when compiling a loader
5066 that is executed after the SPL and before the actual U-Boot.
5067 It is loaded by the SPL.
5069 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5070 Only for 85xx systems. If this variable is specified, the section
5071 .resetvec is not kept and the section .bootpg is placed in the
5072 previous 4k of the .text section.
5074 - CONFIG_ARCH_MAP_SYSMEM
5075 Generally U-Boot (and in particular the md command) uses
5076 effective address. It is therefore not necessary to regard
5077 U-Boot address as virtual addresses that need to be translated
5078 to physical addresses. However, sandbox requires this, since
5079 it maintains its own little RAM buffer which contains all
5080 addressable memory. This option causes some memory accesses
5081 to be mapped through map_sysmem() / unmap_sysmem().
5083 - CONFIG_USE_ARCH_MEMCPY
5084 CONFIG_USE_ARCH_MEMSET
5085 If these options are used a optimized version of memcpy/memset will
5086 be used if available. These functions may be faster under some
5087 conditions but may increase the binary size.
5089 - CONFIG_X86_RESET_VECTOR
5090 If defined, the x86 reset vector code is included. This is not
5091 needed when U-Boot is running from Coreboot.
5094 Defines the MPU clock speed (in MHz).
5096 NOTE : currently only supported on AM335x platforms.
5098 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5099 Enables the RTC32K OSC on AM33xx based plattforms
5101 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5102 Option to disable subpage write in NAND driver
5103 driver that uses this:
5104 drivers/mtd/nand/davinci_nand.c
5106 Freescale QE/FMAN Firmware Support:
5107 -----------------------------------
5109 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5110 loading of "firmware", which is encoded in the QE firmware binary format.
5111 This firmware often needs to be loaded during U-Boot booting, so macros
5112 are used to identify the storage device (NOR flash, SPI, etc) and the address
5115 - CONFIG_SYS_FMAN_FW_ADDR
5116 The address in the storage device where the FMAN microcode is located. The
5117 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5120 - CONFIG_SYS_QE_FW_ADDR
5121 The address in the storage device where the QE microcode is located. The
5122 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5125 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5126 The maximum possible size of the firmware. The firmware binary format
5127 has a field that specifies the actual size of the firmware, but it
5128 might not be possible to read any part of the firmware unless some
5129 local storage is allocated to hold the entire firmware first.
5131 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5132 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5133 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5134 virtual address in NOR flash.
5136 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5137 Specifies that QE/FMAN firmware is located in NAND flash.
5138 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5140 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5141 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5142 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5144 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5145 Specifies that QE/FMAN firmware is located on the primary SPI
5146 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5148 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5149 Specifies that QE/FMAN firmware is located in the remote (master)
5150 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5151 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5152 window->master inbound window->master LAW->the ucode address in
5153 master's memory space.
5155 Freescale Layerscape Management Complex Firmware Support:
5156 ---------------------------------------------------------
5157 The Freescale Layerscape Management Complex (MC) supports the loading of
5159 This firmware often needs to be loaded during U-Boot booting, so macros
5160 are used to identify the storage device (NOR flash, SPI, etc) and the address
5163 - CONFIG_FSL_MC_ENET
5164 Enable the MC driver for Layerscape SoCs.
5166 - CONFIG_SYS_LS_MC_FW_ADDR
5167 The address in the storage device where the firmware is located. The
5168 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5171 - CONFIG_SYS_LS_MC_FW_LENGTH
5172 The maximum possible size of the firmware. The firmware binary format
5173 has a field that specifies the actual size of the firmware, but it
5174 might not be possible to read any part of the firmware unless some
5175 local storage is allocated to hold the entire firmware first.
5177 - CONFIG_SYS_LS_MC_FW_IN_NOR
5178 Specifies that MC firmware is located in NOR flash, mapped as
5179 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5180 virtual address in NOR flash.
5182 Freescale Layerscape Debug Server Support:
5183 -------------------------------------------
5184 The Freescale Layerscape Debug Server Support supports the loading of
5185 "Debug Server firmware" and triggering SP boot-rom.
5186 This firmware often needs to be loaded during U-Boot booting.
5188 - CONFIG_FSL_DEBUG_SERVER
5189 Enable the Debug Server for Layerscape SoCs.
5191 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5192 Define minimum DDR size required for debug server image
5194 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5195 Define minimum DDR size to be hided from top of the DDR memory
5200 In order to achieve reproducible builds, timestamps used in the U-Boot build
5201 process have to be set to a fixed value.
5203 This is done using the SOURCE_DATE_EPOCH environment variable.
5204 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5205 option for U-Boot or an environment variable in U-Boot.
5207 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5209 Building the Software:
5210 ======================
5212 Building U-Boot has been tested in several native build environments
5213 and in many different cross environments. Of course we cannot support
5214 all possibly existing versions of cross development tools in all
5215 (potentially obsolete) versions. In case of tool chain problems we
5216 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5217 which is extensively used to build and test U-Boot.
5219 If you are not using a native environment, it is assumed that you
5220 have GNU cross compiling tools available in your path. In this case,
5221 you must set the environment variable CROSS_COMPILE in your shell.
5222 Note that no changes to the Makefile or any other source files are
5223 necessary. For example using the ELDK on a 4xx CPU, please enter:
5225 $ CROSS_COMPILE=ppc_4xx-
5226 $ export CROSS_COMPILE
5228 Note: If you wish to generate Windows versions of the utilities in
5229 the tools directory you can use the MinGW toolchain
5230 (http://www.mingw.org). Set your HOST tools to the MinGW
5231 toolchain and execute 'make tools'. For example:
5233 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5235 Binaries such as tools/mkimage.exe will be created which can
5236 be executed on computers running Windows.
5238 U-Boot is intended to be simple to build. After installing the
5239 sources you must configure U-Boot for one specific board type. This
5244 where "NAME_defconfig" is the name of one of the existing configu-
5245 rations; see boards.cfg for supported names.
5247 Note: for some board special configuration names may exist; check if
5248 additional information is available from the board vendor; for
5249 instance, the TQM823L systems are available without (standard)
5250 or with LCD support. You can select such additional "features"
5251 when choosing the configuration, i. e.
5253 make TQM823L_defconfig
5254 - will configure for a plain TQM823L, i. e. no LCD support
5256 make TQM823L_LCD_defconfig
5257 - will configure for a TQM823L with U-Boot console on LCD
5262 Finally, type "make all", and you should get some working U-Boot
5263 images ready for download to / installation on your system:
5265 - "u-boot.bin" is a raw binary image
5266 - "u-boot" is an image in ELF binary format
5267 - "u-boot.srec" is in Motorola S-Record format
5269 By default the build is performed locally and the objects are saved
5270 in the source directory. One of the two methods can be used to change
5271 this behavior and build U-Boot to some external directory:
5273 1. Add O= to the make command line invocations:
5275 make O=/tmp/build distclean
5276 make O=/tmp/build NAME_defconfig
5277 make O=/tmp/build all
5279 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5281 export KBUILD_OUTPUT=/tmp/build
5286 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5290 Please be aware that the Makefiles assume you are using GNU make, so
5291 for instance on NetBSD you might need to use "gmake" instead of
5295 If the system board that you have is not listed, then you will need
5296 to port U-Boot to your hardware platform. To do this, follow these
5299 1. Add a new configuration option for your board to the toplevel
5300 "boards.cfg" file, using the existing entries as examples.
5301 Follow the instructions there to keep the boards in order.
5302 2. Create a new directory to hold your board specific code. Add any
5303 files you need. In your board directory, you will need at least
5304 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5305 3. Create a new configuration file "include/configs/<board>.h" for
5307 3. If you're porting U-Boot to a new CPU, then also create a new
5308 directory to hold your CPU specific code. Add any files you need.
5309 4. Run "make <board>_defconfig" with your new name.
5310 5. Type "make", and you should get a working "u-boot.srec" file
5311 to be installed on your target system.
5312 6. Debug and solve any problems that might arise.
5313 [Of course, this last step is much harder than it sounds.]
5316 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5317 ==============================================================
5319 If you have modified U-Boot sources (for instance added a new board
5320 or support for new devices, a new CPU, etc.) you are expected to
5321 provide feedback to the other developers. The feedback normally takes
5322 the form of a "patch", i. e. a context diff against a certain (latest
5323 official or latest in the git repository) version of U-Boot sources.
5325 But before you submit such a patch, please verify that your modifi-
5326 cation did not break existing code. At least make sure that *ALL* of
5327 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5328 just run the "MAKEALL" script, which will configure and build U-Boot
5329 for ALL supported system. Be warned, this will take a while. You can
5330 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5331 environment variable to the script, i. e. to use the ELDK cross tools
5334 CROSS_COMPILE=ppc_8xx- MAKEALL
5336 or to build on a native PowerPC system you can type
5338 CROSS_COMPILE=' ' MAKEALL
5340 When using the MAKEALL script, the default behaviour is to build
5341 U-Boot in the source directory. This location can be changed by
5342 setting the BUILD_DIR environment variable. Also, for each target
5343 built, the MAKEALL script saves two log files (<target>.ERR and
5344 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5345 location can be changed by setting the MAKEALL_LOGDIR environment
5346 variable. For example:
5348 export BUILD_DIR=/tmp/build
5349 export MAKEALL_LOGDIR=/tmp/log
5350 CROSS_COMPILE=ppc_8xx- MAKEALL
5352 With the above settings build objects are saved in the /tmp/build,
5353 log files are saved in the /tmp/log and the source tree remains clean
5354 during the whole build process.
5357 See also "U-Boot Porting Guide" below.
5360 Monitor Commands - Overview:
5361 ============================
5363 go - start application at address 'addr'
5364 run - run commands in an environment variable
5365 bootm - boot application image from memory
5366 bootp - boot image via network using BootP/TFTP protocol
5367 bootz - boot zImage from memory
5368 tftpboot- boot image via network using TFTP protocol
5369 and env variables "ipaddr" and "serverip"
5370 (and eventually "gatewayip")
5371 tftpput - upload a file via network using TFTP protocol
5372 rarpboot- boot image via network using RARP/TFTP protocol
5373 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5374 loads - load S-Record file over serial line
5375 loadb - load binary file over serial line (kermit mode)
5377 mm - memory modify (auto-incrementing)
5378 nm - memory modify (constant address)
5379 mw - memory write (fill)
5381 cmp - memory compare
5382 crc32 - checksum calculation
5383 i2c - I2C sub-system
5384 sspi - SPI utility commands
5385 base - print or set address offset
5386 printenv- print environment variables
5387 setenv - set environment variables
5388 saveenv - save environment variables to persistent storage
5389 protect - enable or disable FLASH write protection
5390 erase - erase FLASH memory
5391 flinfo - print FLASH memory information
5392 nand - NAND memory operations (see doc/README.nand)
5393 bdinfo - print Board Info structure
5394 iminfo - print header information for application image
5395 coninfo - print console devices and informations
5396 ide - IDE sub-system
5397 loop - infinite loop on address range
5398 loopw - infinite write loop on address range
5399 mtest - simple RAM test
5400 icache - enable or disable instruction cache
5401 dcache - enable or disable data cache
5402 reset - Perform RESET of the CPU
5403 echo - echo args to console
5404 version - print monitor version
5405 help - print online help
5406 ? - alias for 'help'
5409 Monitor Commands - Detailed Description:
5410 ========================================
5414 For now: just type "help <command>".
5417 Environment Variables:
5418 ======================
5420 U-Boot supports user configuration using Environment Variables which
5421 can be made persistent by saving to Flash memory.
5423 Environment Variables are set using "setenv", printed using
5424 "printenv", and saved to Flash using "saveenv". Using "setenv"
5425 without a value can be used to delete a variable from the
5426 environment. As long as you don't save the environment you are
5427 working with an in-memory copy. In case the Flash area containing the
5428 environment is erased by accident, a default environment is provided.
5430 Some configuration options can be set using Environment Variables.
5432 List of environment variables (most likely not complete):
5434 baudrate - see CONFIG_BAUDRATE
5436 bootdelay - see CONFIG_BOOTDELAY
5438 bootcmd - see CONFIG_BOOTCOMMAND
5440 bootargs - Boot arguments when booting an RTOS image
5442 bootfile - Name of the image to load with TFTP
5444 bootm_low - Memory range available for image processing in the bootm
5445 command can be restricted. This variable is given as
5446 a hexadecimal number and defines lowest address allowed
5447 for use by the bootm command. See also "bootm_size"
5448 environment variable. Address defined by "bootm_low" is
5449 also the base of the initial memory mapping for the Linux
5450 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5453 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5454 This variable is given as a hexadecimal number and it
5455 defines the size of the memory region starting at base
5456 address bootm_low that is accessible by the Linux kernel
5457 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5458 as the default value if it is defined, and bootm_size is
5461 bootm_size - Memory range available for image processing in the bootm
5462 command can be restricted. This variable is given as
5463 a hexadecimal number and defines the size of the region
5464 allowed for use by the bootm command. See also "bootm_low"
5465 environment variable.
5467 updatefile - Location of the software update file on a TFTP server, used
5468 by the automatic software update feature. Please refer to
5469 documentation in doc/README.update for more details.
5471 autoload - if set to "no" (any string beginning with 'n'),
5472 "bootp" will just load perform a lookup of the
5473 configuration from the BOOTP server, but not try to
5474 load any image using TFTP
5476 autostart - if set to "yes", an image loaded using the "bootp",
5477 "rarpboot", "tftpboot" or "diskboot" commands will
5478 be automatically started (by internally calling
5481 If set to "no", a standalone image passed to the
5482 "bootm" command will be copied to the load address
5483 (and eventually uncompressed), but NOT be started.
5484 This can be used to load and uncompress arbitrary
5487 fdt_high - if set this restricts the maximum address that the
5488 flattened device tree will be copied into upon boot.
5489 For example, if you have a system with 1 GB memory
5490 at physical address 0x10000000, while Linux kernel
5491 only recognizes the first 704 MB as low memory, you
5492 may need to set fdt_high as 0x3C000000 to have the
5493 device tree blob be copied to the maximum address
5494 of the 704 MB low memory, so that Linux kernel can
5495 access it during the boot procedure.
5497 If this is set to the special value 0xFFFFFFFF then
5498 the fdt will not be copied at all on boot. For this
5499 to work it must reside in writable memory, have
5500 sufficient padding on the end of it for u-boot to
5501 add the information it needs into it, and the memory
5502 must be accessible by the kernel.
5504 fdtcontroladdr- if set this is the address of the control flattened
5505 device tree used by U-Boot when CONFIG_OF_CONTROL is
5508 i2cfast - (PPC405GP|PPC405EP only)
5509 if set to 'y' configures Linux I2C driver for fast
5510 mode (400kHZ). This environment variable is used in
5511 initialization code. So, for changes to be effective
5512 it must be saved and board must be reset.
5514 initrd_high - restrict positioning of initrd images:
5515 If this variable is not set, initrd images will be
5516 copied to the highest possible address in RAM; this
5517 is usually what you want since it allows for
5518 maximum initrd size. If for some reason you want to
5519 make sure that the initrd image is loaded below the
5520 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5521 variable to a value of "no" or "off" or "0".
5522 Alternatively, you can set it to a maximum upper
5523 address to use (U-Boot will still check that it
5524 does not overwrite the U-Boot stack and data).
5526 For instance, when you have a system with 16 MB
5527 RAM, and want to reserve 4 MB from use by Linux,
5528 you can do this by adding "mem=12M" to the value of
5529 the "bootargs" variable. However, now you must make
5530 sure that the initrd image is placed in the first
5531 12 MB as well - this can be done with
5533 setenv initrd_high 00c00000
5535 If you set initrd_high to 0xFFFFFFFF, this is an
5536 indication to U-Boot that all addresses are legal
5537 for the Linux kernel, including addresses in flash
5538 memory. In this case U-Boot will NOT COPY the
5539 ramdisk at all. This may be useful to reduce the
5540 boot time on your system, but requires that this
5541 feature is supported by your Linux kernel.
5543 ipaddr - IP address; needed for tftpboot command
5545 loadaddr - Default load address for commands like "bootp",
5546 "rarpboot", "tftpboot", "loadb" or "diskboot"
5548 loads_echo - see CONFIG_LOADS_ECHO
5550 serverip - TFTP server IP address; needed for tftpboot command
5552 bootretry - see CONFIG_BOOT_RETRY_TIME
5554 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5556 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5558 ethprime - controls which interface is used first.
5560 ethact - controls which interface is currently active.
5561 For example you can do the following
5563 => setenv ethact FEC
5564 => ping 192.168.0.1 # traffic sent on FEC
5565 => setenv ethact SCC
5566 => ping 10.0.0.1 # traffic sent on SCC
5568 ethrotate - When set to "no" U-Boot does not go through all
5569 available network interfaces.
5570 It just stays at the currently selected interface.
5572 netretry - When set to "no" each network operation will
5573 either succeed or fail without retrying.
5574 When set to "once" the network operation will
5575 fail when all the available network interfaces
5576 are tried once without success.
5577 Useful on scripts which control the retry operation
5580 npe_ucode - set load address for the NPE microcode
5582 silent_linux - If set then Linux will be told to boot silently, by
5583 changing the console to be empty. If "yes" it will be
5584 made silent. If "no" it will not be made silent. If
5585 unset, then it will be made silent if the U-Boot console
5588 tftpsrcport - If this is set, the value is used for TFTP's
5591 tftpdstport - If this is set, the value is used for TFTP's UDP
5592 destination port instead of the Well Know Port 69.
5594 tftpblocksize - Block size to use for TFTP transfers; if not set,
5595 we use the TFTP server's default block size
5597 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5598 seconds, minimum value is 1000 = 1 second). Defines
5599 when a packet is considered to be lost so it has to
5600 be retransmitted. The default is 5000 = 5 seconds.
5601 Lowering this value may make downloads succeed
5602 faster in networks with high packet loss rates or
5603 with unreliable TFTP servers.
5605 vlan - When set to a value < 4095 the traffic over
5606 Ethernet is encapsulated/received over 802.1q
5609 The following image location variables contain the location of images
5610 used in booting. The "Image" column gives the role of the image and is
5611 not an environment variable name. The other columns are environment
5612 variable names. "File Name" gives the name of the file on a TFTP
5613 server, "RAM Address" gives the location in RAM the image will be
5614 loaded to, and "Flash Location" gives the image's address in NOR
5615 flash or offset in NAND flash.
5617 *Note* - these variables don't have to be defined for all boards, some
5618 boards currently use other variables for these purposes, and some
5619 boards use these variables for other purposes.
5621 Image File Name RAM Address Flash Location
5622 ----- --------- ----------- --------------
5623 u-boot u-boot u-boot_addr_r u-boot_addr
5624 Linux kernel bootfile kernel_addr_r kernel_addr
5625 device tree blob fdtfile fdt_addr_r fdt_addr
5626 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5628 The following environment variables may be used and automatically
5629 updated by the network boot commands ("bootp" and "rarpboot"),
5630 depending the information provided by your boot server:
5632 bootfile - see above
5633 dnsip - IP address of your Domain Name Server
5634 dnsip2 - IP address of your secondary Domain Name Server
5635 gatewayip - IP address of the Gateway (Router) to use
5636 hostname - Target hostname
5638 netmask - Subnet Mask
5639 rootpath - Pathname of the root filesystem on the NFS server
5640 serverip - see above
5643 There are two special Environment Variables:
5645 serial# - contains hardware identification information such
5646 as type string and/or serial number
5647 ethaddr - Ethernet address
5649 These variables can be set only once (usually during manufacturing of
5650 the board). U-Boot refuses to delete or overwrite these variables
5651 once they have been set once.
5654 Further special Environment Variables:
5656 ver - Contains the U-Boot version string as printed
5657 with the "version" command. This variable is
5658 readonly (see CONFIG_VERSION_VARIABLE).
5661 Please note that changes to some configuration parameters may take
5662 only effect after the next boot (yes, that's just like Windoze :-).
5665 Callback functions for environment variables:
5666 ---------------------------------------------
5668 For some environment variables, the behavior of u-boot needs to change
5669 when their values are changed. This functionality allows functions to
5670 be associated with arbitrary variables. On creation, overwrite, or
5671 deletion, the callback will provide the opportunity for some side
5672 effect to happen or for the change to be rejected.
5674 The callbacks are named and associated with a function using the
5675 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5677 These callbacks are associated with variables in one of two ways. The
5678 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5679 in the board configuration to a string that defines a list of
5680 associations. The list must be in the following format:
5682 entry = variable_name[:callback_name]
5685 If the callback name is not specified, then the callback is deleted.
5686 Spaces are also allowed anywhere in the list.
5688 Callbacks can also be associated by defining the ".callbacks" variable
5689 with the same list format above. Any association in ".callbacks" will
5690 override any association in the static list. You can define
5691 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5692 ".callbacks" environment variable in the default or embedded environment.
5694 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5695 regular expression. This allows multiple variables to be connected to
5696 the same callback without explicitly listing them all out.
5699 Command Line Parsing:
5700 =====================
5702 There are two different command line parsers available with U-Boot:
5703 the old "simple" one, and the much more powerful "hush" shell:
5705 Old, simple command line parser:
5706 --------------------------------
5708 - supports environment variables (through setenv / saveenv commands)
5709 - several commands on one line, separated by ';'
5710 - variable substitution using "... ${name} ..." syntax
5711 - special characters ('$', ';') can be escaped by prefixing with '\',
5713 setenv bootcmd bootm \${address}
5714 - You can also escape text by enclosing in single apostrophes, for example:
5715 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5720 - similar to Bourne shell, with control structures like
5721 if...then...else...fi, for...do...done; while...do...done,
5722 until...do...done, ...
5723 - supports environment ("global") variables (through setenv / saveenv
5724 commands) and local shell variables (through standard shell syntax
5725 "name=value"); only environment variables can be used with "run"
5731 (1) If a command line (or an environment variable executed by a "run"
5732 command) contains several commands separated by semicolon, and
5733 one of these commands fails, then the remaining commands will be
5736 (2) If you execute several variables with one call to run (i. e.
5737 calling run with a list of variables as arguments), any failing
5738 command will cause "run" to terminate, i. e. the remaining
5739 variables are not executed.
5741 Note for Redundant Ethernet Interfaces:
5742 =======================================
5744 Some boards come with redundant Ethernet interfaces; U-Boot supports
5745 such configurations and is capable of automatic selection of a
5746 "working" interface when needed. MAC assignment works as follows:
5748 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5749 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5750 "eth1addr" (=>eth1), "eth2addr", ...
5752 If the network interface stores some valid MAC address (for instance
5753 in SROM), this is used as default address if there is NO correspon-
5754 ding setting in the environment; if the corresponding environment
5755 variable is set, this overrides the settings in the card; that means:
5757 o If the SROM has a valid MAC address, and there is no address in the
5758 environment, the SROM's address is used.
5760 o If there is no valid address in the SROM, and a definition in the
5761 environment exists, then the value from the environment variable is
5764 o If both the SROM and the environment contain a MAC address, and
5765 both addresses are the same, this MAC address is used.
5767 o If both the SROM and the environment contain a MAC address, and the
5768 addresses differ, the value from the environment is used and a
5771 o If neither SROM nor the environment contain a MAC address, an error
5772 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5773 a random, locally-assigned MAC is used.
5775 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5776 will be programmed into hardware as part of the initialization process. This
5777 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5778 The naming convention is as follows:
5779 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5784 U-Boot is capable of booting (and performing other auxiliary operations on)
5785 images in two formats:
5787 New uImage format (FIT)
5788 -----------------------
5790 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5791 to Flattened Device Tree). It allows the use of images with multiple
5792 components (several kernels, ramdisks, etc.), with contents protected by
5793 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5799 Old image format is based on binary files which can be basically anything,
5800 preceded by a special header; see the definitions in include/image.h for
5801 details; basically, the header defines the following image properties:
5803 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5804 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5805 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5806 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5808 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5809 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5810 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5811 * Compression Type (uncompressed, gzip, bzip2)
5817 The header is marked by a special Magic Number, and both the header
5818 and the data portions of the image are secured against corruption by
5825 Although U-Boot should support any OS or standalone application
5826 easily, the main focus has always been on Linux during the design of
5829 U-Boot includes many features that so far have been part of some
5830 special "boot loader" code within the Linux kernel. Also, any
5831 "initrd" images to be used are no longer part of one big Linux image;
5832 instead, kernel and "initrd" are separate images. This implementation
5833 serves several purposes:
5835 - the same features can be used for other OS or standalone
5836 applications (for instance: using compressed images to reduce the
5837 Flash memory footprint)
5839 - it becomes much easier to port new Linux kernel versions because
5840 lots of low-level, hardware dependent stuff are done by U-Boot
5842 - the same Linux kernel image can now be used with different "initrd"
5843 images; of course this also means that different kernel images can
5844 be run with the same "initrd". This makes testing easier (you don't
5845 have to build a new "zImage.initrd" Linux image when you just
5846 change a file in your "initrd"). Also, a field-upgrade of the
5847 software is easier now.
5853 Porting Linux to U-Boot based systems:
5854 ---------------------------------------
5856 U-Boot cannot save you from doing all the necessary modifications to
5857 configure the Linux device drivers for use with your target hardware
5858 (no, we don't intend to provide a full virtual machine interface to
5861 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5863 Just make sure your machine specific header file (for instance
5864 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5865 Information structure as we define in include/asm-<arch>/u-boot.h,
5866 and make sure that your definition of IMAP_ADDR uses the same value
5867 as your U-Boot configuration in CONFIG_SYS_IMMR.
5869 Note that U-Boot now has a driver model, a unified model for drivers.
5870 If you are adding a new driver, plumb it into driver model. If there
5871 is no uclass available, you are encouraged to create one. See
5875 Configuring the Linux kernel:
5876 -----------------------------
5878 No specific requirements for U-Boot. Make sure you have some root
5879 device (initial ramdisk, NFS) for your target system.
5882 Building a Linux Image:
5883 -----------------------
5885 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5886 not used. If you use recent kernel source, a new build target
5887 "uImage" will exist which automatically builds an image usable by
5888 U-Boot. Most older kernels also have support for a "pImage" target,
5889 which was introduced for our predecessor project PPCBoot and uses a
5890 100% compatible format.
5894 make TQM850L_defconfig
5899 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5900 encapsulate a compressed Linux kernel image with header information,
5901 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5903 * build a standard "vmlinux" kernel image (in ELF binary format):
5905 * convert the kernel into a raw binary image:
5907 ${CROSS_COMPILE}-objcopy -O binary \
5908 -R .note -R .comment \
5909 -S vmlinux linux.bin
5911 * compress the binary image:
5915 * package compressed binary image for U-Boot:
5917 mkimage -A ppc -O linux -T kernel -C gzip \
5918 -a 0 -e 0 -n "Linux Kernel Image" \
5919 -d linux.bin.gz uImage
5922 The "mkimage" tool can also be used to create ramdisk images for use
5923 with U-Boot, either separated from the Linux kernel image, or
5924 combined into one file. "mkimage" encapsulates the images with a 64
5925 byte header containing information about target architecture,
5926 operating system, image type, compression method, entry points, time
5927 stamp, CRC32 checksums, etc.
5929 "mkimage" can be called in two ways: to verify existing images and
5930 print the header information, or to build new images.
5932 In the first form (with "-l" option) mkimage lists the information
5933 contained in the header of an existing U-Boot image; this includes
5934 checksum verification:
5936 tools/mkimage -l image
5937 -l ==> list image header information
5939 The second form (with "-d" option) is used to build a U-Boot image
5940 from a "data file" which is used as image payload:
5942 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5943 -n name -d data_file image
5944 -A ==> set architecture to 'arch'
5945 -O ==> set operating system to 'os'
5946 -T ==> set image type to 'type'
5947 -C ==> set compression type 'comp'
5948 -a ==> set load address to 'addr' (hex)
5949 -e ==> set entry point to 'ep' (hex)
5950 -n ==> set image name to 'name'
5951 -d ==> use image data from 'datafile'
5953 Right now, all Linux kernels for PowerPC systems use the same load
5954 address (0x00000000), but the entry point address depends on the
5957 - 2.2.x kernels have the entry point at 0x0000000C,
5958 - 2.3.x and later kernels have the entry point at 0x00000000.
5960 So a typical call to build a U-Boot image would read:
5962 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5963 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5964 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5965 > examples/uImage.TQM850L
5966 Image Name: 2.4.4 kernel for TQM850L
5967 Created: Wed Jul 19 02:34:59 2000
5968 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5969 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5970 Load Address: 0x00000000
5971 Entry Point: 0x00000000
5973 To verify the contents of the image (or check for corruption):
5975 -> tools/mkimage -l examples/uImage.TQM850L
5976 Image Name: 2.4.4 kernel for TQM850L
5977 Created: Wed Jul 19 02:34:59 2000
5978 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5979 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5980 Load Address: 0x00000000
5981 Entry Point: 0x00000000
5983 NOTE: for embedded systems where boot time is critical you can trade
5984 speed for memory and install an UNCOMPRESSED image instead: this
5985 needs more space in Flash, but boots much faster since it does not
5986 need to be uncompressed:
5988 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5989 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5990 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5991 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5992 > examples/uImage.TQM850L-uncompressed
5993 Image Name: 2.4.4 kernel for TQM850L
5994 Created: Wed Jul 19 02:34:59 2000
5995 Image Type: PowerPC Linux Kernel Image (uncompressed)
5996 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5997 Load Address: 0x00000000
5998 Entry Point: 0x00000000
6001 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
6002 when your kernel is intended to use an initial ramdisk:
6004 -> tools/mkimage -n 'Simple Ramdisk Image' \
6005 > -A ppc -O linux -T ramdisk -C gzip \
6006 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
6007 Image Name: Simple Ramdisk Image
6008 Created: Wed Jan 12 14:01:50 2000
6009 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6010 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6011 Load Address: 0x00000000
6012 Entry Point: 0x00000000
6014 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6015 option performs the converse operation of the mkimage's second form (the "-d"
6016 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6019 tools/dumpimage -i image -T type -p position data_file
6020 -i ==> extract from the 'image' a specific 'data_file'
6021 -T ==> set image type to 'type'
6022 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6025 Installing a Linux Image:
6026 -------------------------
6028 To downloading a U-Boot image over the serial (console) interface,
6029 you must convert the image to S-Record format:
6031 objcopy -I binary -O srec examples/image examples/image.srec
6033 The 'objcopy' does not understand the information in the U-Boot
6034 image header, so the resulting S-Record file will be relative to
6035 address 0x00000000. To load it to a given address, you need to
6036 specify the target address as 'offset' parameter with the 'loads'
6039 Example: install the image to address 0x40100000 (which on the
6040 TQM8xxL is in the first Flash bank):
6042 => erase 40100000 401FFFFF
6048 ## Ready for S-Record download ...
6049 ~>examples/image.srec
6050 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6052 15989 15990 15991 15992
6053 [file transfer complete]
6055 ## Start Addr = 0x00000000
6058 You can check the success of the download using the 'iminfo' command;
6059 this includes a checksum verification so you can be sure no data
6060 corruption happened:
6064 ## Checking Image at 40100000 ...
6065 Image Name: 2.2.13 for initrd on TQM850L
6066 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6067 Data Size: 335725 Bytes = 327 kB = 0 MB
6068 Load Address: 00000000
6069 Entry Point: 0000000c
6070 Verifying Checksum ... OK
6076 The "bootm" command is used to boot an application that is stored in
6077 memory (RAM or Flash). In case of a Linux kernel image, the contents
6078 of the "bootargs" environment variable is passed to the kernel as
6079 parameters. You can check and modify this variable using the
6080 "printenv" and "setenv" commands:
6083 => printenv bootargs
6084 bootargs=root=/dev/ram
6086 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6088 => printenv bootargs
6089 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6092 ## Booting Linux kernel at 40020000 ...
6093 Image Name: 2.2.13 for NFS on TQM850L
6094 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6095 Data Size: 381681 Bytes = 372 kB = 0 MB
6096 Load Address: 00000000
6097 Entry Point: 0000000c
6098 Verifying Checksum ... OK
6099 Uncompressing Kernel Image ... OK
6100 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
6101 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6102 time_init: decrementer frequency = 187500000/60
6103 Calibrating delay loop... 49.77 BogoMIPS
6104 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6107 If you want to boot a Linux kernel with initial RAM disk, you pass
6108 the memory addresses of both the kernel and the initrd image (PPBCOOT
6109 format!) to the "bootm" command:
6111 => imi 40100000 40200000
6113 ## Checking Image at 40100000 ...
6114 Image Name: 2.2.13 for initrd on TQM850L
6115 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6116 Data Size: 335725 Bytes = 327 kB = 0 MB
6117 Load Address: 00000000
6118 Entry Point: 0000000c
6119 Verifying Checksum ... OK
6121 ## Checking Image at 40200000 ...
6122 Image Name: Simple Ramdisk Image
6123 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6124 Data Size: 566530 Bytes = 553 kB = 0 MB
6125 Load Address: 00000000
6126 Entry Point: 00000000
6127 Verifying Checksum ... OK
6129 => bootm 40100000 40200000
6130 ## Booting Linux kernel at 40100000 ...
6131 Image Name: 2.2.13 for initrd on TQM850L
6132 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6133 Data Size: 335725 Bytes = 327 kB = 0 MB
6134 Load Address: 00000000
6135 Entry Point: 0000000c
6136 Verifying Checksum ... OK
6137 Uncompressing Kernel Image ... OK
6138 ## Loading RAMDisk Image at 40200000 ...
6139 Image Name: Simple Ramdisk Image
6140 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6141 Data Size: 566530 Bytes = 553 kB = 0 MB
6142 Load Address: 00000000
6143 Entry Point: 00000000
6144 Verifying Checksum ... OK
6145 Loading Ramdisk ... OK
6146 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
6147 Boot arguments: root=/dev/ram
6148 time_init: decrementer frequency = 187500000/60
6149 Calibrating delay loop... 49.77 BogoMIPS
6151 RAMDISK: Compressed image found at block 0
6152 VFS: Mounted root (ext2 filesystem).
6156 Boot Linux and pass a flat device tree:
6159 First, U-Boot must be compiled with the appropriate defines. See the section
6160 titled "Linux Kernel Interface" above for a more in depth explanation. The
6161 following is an example of how to start a kernel and pass an updated
6167 oft=oftrees/mpc8540ads.dtb
6168 => tftp $oftaddr $oft
6169 Speed: 1000, full duplex
6171 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6172 Filename 'oftrees/mpc8540ads.dtb'.
6173 Load address: 0x300000
6176 Bytes transferred = 4106 (100a hex)
6177 => tftp $loadaddr $bootfile
6178 Speed: 1000, full duplex
6180 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6182 Load address: 0x200000
6183 Loading:############
6185 Bytes transferred = 1029407 (fb51f hex)
6190 => bootm $loadaddr - $oftaddr
6191 ## Booting image at 00200000 ...
6192 Image Name: Linux-2.6.17-dirty
6193 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6194 Data Size: 1029343 Bytes = 1005.2 kB
6195 Load Address: 00000000
6196 Entry Point: 00000000
6197 Verifying Checksum ... OK
6198 Uncompressing Kernel Image ... OK
6199 Booting using flat device tree at 0x300000
6200 Using MPC85xx ADS machine description
6201 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6205 More About U-Boot Image Types:
6206 ------------------------------
6208 U-Boot supports the following image types:
6210 "Standalone Programs" are directly runnable in the environment
6211 provided by U-Boot; it is expected that (if they behave
6212 well) you can continue to work in U-Boot after return from
6213 the Standalone Program.
6214 "OS Kernel Images" are usually images of some Embedded OS which
6215 will take over control completely. Usually these programs
6216 will install their own set of exception handlers, device
6217 drivers, set up the MMU, etc. - this means, that you cannot
6218 expect to re-enter U-Boot except by resetting the CPU.
6219 "RAMDisk Images" are more or less just data blocks, and their
6220 parameters (address, size) are passed to an OS kernel that is
6222 "Multi-File Images" contain several images, typically an OS
6223 (Linux) kernel image and one or more data images like
6224 RAMDisks. This construct is useful for instance when you want
6225 to boot over the network using BOOTP etc., where the boot
6226 server provides just a single image file, but you want to get
6227 for instance an OS kernel and a RAMDisk image.
6229 "Multi-File Images" start with a list of image sizes, each
6230 image size (in bytes) specified by an "uint32_t" in network
6231 byte order. This list is terminated by an "(uint32_t)0".
6232 Immediately after the terminating 0 follow the images, one by
6233 one, all aligned on "uint32_t" boundaries (size rounded up to
6234 a multiple of 4 bytes).
6236 "Firmware Images" are binary images containing firmware (like
6237 U-Boot or FPGA images) which usually will be programmed to
6240 "Script files" are command sequences that will be executed by
6241 U-Boot's command interpreter; this feature is especially
6242 useful when you configure U-Boot to use a real shell (hush)
6243 as command interpreter.
6245 Booting the Linux zImage:
6246 -------------------------
6248 On some platforms, it's possible to boot Linux zImage. This is done
6249 using the "bootz" command. The syntax of "bootz" command is the same
6250 as the syntax of "bootm" command.
6252 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6253 kernel with raw initrd images. The syntax is slightly different, the
6254 address of the initrd must be augmented by it's size, in the following
6255 format: "<initrd addres>:<initrd size>".
6261 One of the features of U-Boot is that you can dynamically load and
6262 run "standalone" applications, which can use some resources of
6263 U-Boot like console I/O functions or interrupt services.
6265 Two simple examples are included with the sources:
6270 'examples/hello_world.c' contains a small "Hello World" Demo
6271 application; it is automatically compiled when you build U-Boot.
6272 It's configured to run at address 0x00040004, so you can play with it
6276 ## Ready for S-Record download ...
6277 ~>examples/hello_world.srec
6278 1 2 3 4 5 6 7 8 9 10 11 ...
6279 [file transfer complete]
6281 ## Start Addr = 0x00040004
6283 => go 40004 Hello World! This is a test.
6284 ## Starting application at 0x00040004 ...
6295 Hit any key to exit ...
6297 ## Application terminated, rc = 0x0
6299 Another example, which demonstrates how to register a CPM interrupt
6300 handler with the U-Boot code, can be found in 'examples/timer.c'.
6301 Here, a CPM timer is set up to generate an interrupt every second.
6302 The interrupt service routine is trivial, just printing a '.'
6303 character, but this is just a demo program. The application can be
6304 controlled by the following keys:
6306 ? - print current values og the CPM Timer registers
6307 b - enable interrupts and start timer
6308 e - stop timer and disable interrupts
6309 q - quit application
6312 ## Ready for S-Record download ...
6313 ~>examples/timer.srec
6314 1 2 3 4 5 6 7 8 9 10 11 ...
6315 [file transfer complete]
6317 ## Start Addr = 0x00040004
6320 ## Starting application at 0x00040004 ...
6323 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6326 [q, b, e, ?] Set interval 1000000 us
6329 [q, b, e, ?] ........
6330 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6333 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6336 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6339 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6341 [q, b, e, ?] ...Stopping timer
6343 [q, b, e, ?] ## Application terminated, rc = 0x0
6349 Over time, many people have reported problems when trying to use the
6350 "minicom" terminal emulation program for serial download. I (wd)
6351 consider minicom to be broken, and recommend not to use it. Under
6352 Unix, I recommend to use C-Kermit for general purpose use (and
6353 especially for kermit binary protocol download ("loadb" command), and
6354 use "cu" for S-Record download ("loads" command). See
6355 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6356 for help with kermit.
6359 Nevertheless, if you absolutely want to use it try adding this
6360 configuration to your "File transfer protocols" section:
6362 Name Program Name U/D FullScr IO-Red. Multi
6363 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6364 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6370 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6371 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6373 Building requires a cross environment; it is known to work on
6374 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6375 need gmake since the Makefiles are not compatible with BSD make).
6376 Note that the cross-powerpc package does not install include files;
6377 attempting to build U-Boot will fail because <machine/ansi.h> is
6378 missing. This file has to be installed and patched manually:
6380 # cd /usr/pkg/cross/powerpc-netbsd/include
6382 # ln -s powerpc machine
6383 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6384 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6386 Native builds *don't* work due to incompatibilities between native
6387 and U-Boot include files.
6389 Booting assumes that (the first part of) the image booted is a
6390 stage-2 loader which in turn loads and then invokes the kernel
6391 proper. Loader sources will eventually appear in the NetBSD source
6392 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6393 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6396 Implementation Internals:
6397 =========================
6399 The following is not intended to be a complete description of every
6400 implementation detail. However, it should help to understand the
6401 inner workings of U-Boot and make it easier to port it to custom
6405 Initial Stack, Global Data:
6406 ---------------------------
6408 The implementation of U-Boot is complicated by the fact that U-Boot
6409 starts running out of ROM (flash memory), usually without access to
6410 system RAM (because the memory controller is not initialized yet).
6411 This means that we don't have writable Data or BSS segments, and BSS
6412 is not initialized as zero. To be able to get a C environment working
6413 at all, we have to allocate at least a minimal stack. Implementation
6414 options for this are defined and restricted by the CPU used: Some CPU
6415 models provide on-chip memory (like the IMMR area on MPC8xx and
6416 MPC826x processors), on others (parts of) the data cache can be
6417 locked as (mis-) used as memory, etc.
6419 Chris Hallinan posted a good summary of these issues to the
6420 U-Boot mailing list:
6422 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6423 From: "Chris Hallinan" <clh@net1plus.com>
6424 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6427 Correct me if I'm wrong, folks, but the way I understand it
6428 is this: Using DCACHE as initial RAM for Stack, etc, does not
6429 require any physical RAM backing up the cache. The cleverness
6430 is that the cache is being used as a temporary supply of
6431 necessary storage before the SDRAM controller is setup. It's
6432 beyond the scope of this list to explain the details, but you
6433 can see how this works by studying the cache architecture and
6434 operation in the architecture and processor-specific manuals.
6436 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6437 is another option for the system designer to use as an
6438 initial stack/RAM area prior to SDRAM being available. Either
6439 option should work for you. Using CS 4 should be fine if your
6440 board designers haven't used it for something that would
6441 cause you grief during the initial boot! It is frequently not
6444 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6445 with your processor/board/system design. The default value
6446 you will find in any recent u-boot distribution in
6447 walnut.h should work for you. I'd set it to a value larger
6448 than your SDRAM module. If you have a 64MB SDRAM module, set
6449 it above 400_0000. Just make sure your board has no resources
6450 that are supposed to respond to that address! That code in
6451 start.S has been around a while and should work as is when
6452 you get the config right.
6457 It is essential to remember this, since it has some impact on the C
6458 code for the initialization procedures:
6460 * Initialized global data (data segment) is read-only. Do not attempt
6463 * Do not use any uninitialized global data (or implicitly initialized
6464 as zero data - BSS segment) at all - this is undefined, initiali-
6465 zation is performed later (when relocating to RAM).
6467 * Stack space is very limited. Avoid big data buffers or things like
6470 Having only the stack as writable memory limits means we cannot use
6471 normal global data to share information between the code. But it
6472 turned out that the implementation of U-Boot can be greatly
6473 simplified by making a global data structure (gd_t) available to all
6474 functions. We could pass a pointer to this data as argument to _all_
6475 functions, but this would bloat the code. Instead we use a feature of
6476 the GCC compiler (Global Register Variables) to share the data: we
6477 place a pointer (gd) to the global data into a register which we
6478 reserve for this purpose.
6480 When choosing a register for such a purpose we are restricted by the
6481 relevant (E)ABI specifications for the current architecture, and by
6482 GCC's implementation.
6484 For PowerPC, the following registers have specific use:
6486 R2: reserved for system use
6487 R3-R4: parameter passing and return values
6488 R5-R10: parameter passing
6489 R13: small data area pointer
6493 (U-Boot also uses R12 as internal GOT pointer. r12
6494 is a volatile register so r12 needs to be reset when
6495 going back and forth between asm and C)
6497 ==> U-Boot will use R2 to hold a pointer to the global data
6499 Note: on PPC, we could use a static initializer (since the
6500 address of the global data structure is known at compile time),
6501 but it turned out that reserving a register results in somewhat
6502 smaller code - although the code savings are not that big (on
6503 average for all boards 752 bytes for the whole U-Boot image,
6504 624 text + 127 data).
6506 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6507 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6509 ==> U-Boot will use P3 to hold a pointer to the global data
6511 On ARM, the following registers are used:
6513 R0: function argument word/integer result
6514 R1-R3: function argument word
6515 R9: platform specific
6516 R10: stack limit (used only if stack checking is enabled)
6517 R11: argument (frame) pointer
6518 R12: temporary workspace
6521 R15: program counter
6523 ==> U-Boot will use R9 to hold a pointer to the global data
6525 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6527 On Nios II, the ABI is documented here:
6528 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6530 ==> U-Boot will use gp to hold a pointer to the global data
6532 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6533 to access small data sections, so gp is free.
6535 On NDS32, the following registers are used:
6537 R0-R1: argument/return
6539 R15: temporary register for assembler
6540 R16: trampoline register
6541 R28: frame pointer (FP)
6542 R29: global pointer (GP)
6543 R30: link register (LP)
6544 R31: stack pointer (SP)
6545 PC: program counter (PC)
6547 ==> U-Boot will use R10 to hold a pointer to the global data
6549 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6550 or current versions of GCC may "optimize" the code too much.
6555 U-Boot runs in system state and uses physical addresses, i.e. the
6556 MMU is not used either for address mapping nor for memory protection.
6558 The available memory is mapped to fixed addresses using the memory
6559 controller. In this process, a contiguous block is formed for each
6560 memory type (Flash, SDRAM, SRAM), even when it consists of several
6561 physical memory banks.
6563 U-Boot is installed in the first 128 kB of the first Flash bank (on
6564 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6565 booting and sizing and initializing DRAM, the code relocates itself
6566 to the upper end of DRAM. Immediately below the U-Boot code some
6567 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6568 configuration setting]. Below that, a structure with global Board
6569 Info data is placed, followed by the stack (growing downward).
6571 Additionally, some exception handler code is copied to the low 8 kB
6572 of DRAM (0x00000000 ... 0x00001FFF).
6574 So a typical memory configuration with 16 MB of DRAM could look like
6577 0x0000 0000 Exception Vector code
6580 0x0000 2000 Free for Application Use
6586 0x00FB FF20 Monitor Stack (Growing downward)
6587 0x00FB FFAC Board Info Data and permanent copy of global data
6588 0x00FC 0000 Malloc Arena
6591 0x00FE 0000 RAM Copy of Monitor Code
6592 ... eventually: LCD or video framebuffer
6593 ... eventually: pRAM (Protected RAM - unchanged by reset)
6594 0x00FF FFFF [End of RAM]
6597 System Initialization:
6598 ----------------------
6600 In the reset configuration, U-Boot starts at the reset entry point
6601 (on most PowerPC systems at address 0x00000100). Because of the reset
6602 configuration for CS0# this is a mirror of the on board Flash memory.
6603 To be able to re-map memory U-Boot then jumps to its link address.
6604 To be able to implement the initialization code in C, a (small!)
6605 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6606 which provide such a feature like MPC8xx or MPC8260), or in a locked
6607 part of the data cache. After that, U-Boot initializes the CPU core,
6608 the caches and the SIU.
6610 Next, all (potentially) available memory banks are mapped using a
6611 preliminary mapping. For example, we put them on 512 MB boundaries
6612 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6613 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6614 programmed for SDRAM access. Using the temporary configuration, a
6615 simple memory test is run that determines the size of the SDRAM
6618 When there is more than one SDRAM bank, and the banks are of
6619 different size, the largest is mapped first. For equal size, the first
6620 bank (CS2#) is mapped first. The first mapping is always for address
6621 0x00000000, with any additional banks following immediately to create
6622 contiguous memory starting from 0.
6624 Then, the monitor installs itself at the upper end of the SDRAM area
6625 and allocates memory for use by malloc() and for the global Board
6626 Info data; also, the exception vector code is copied to the low RAM
6627 pages, and the final stack is set up.
6629 Only after this relocation will you have a "normal" C environment;
6630 until that you are restricted in several ways, mostly because you are
6631 running from ROM, and because the code will have to be relocated to a
6635 U-Boot Porting Guide:
6636 ----------------------
6638 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6642 int main(int argc, char *argv[])
6644 sighandler_t no_more_time;
6646 signal(SIGALRM, no_more_time);
6647 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6649 if (available_money > available_manpower) {
6650 Pay consultant to port U-Boot;
6654 Download latest U-Boot source;
6656 Subscribe to u-boot mailing list;
6659 email("Hi, I am new to U-Boot, how do I get started?");
6662 Read the README file in the top level directory;
6663 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6664 Read applicable doc/*.README;
6665 Read the source, Luke;
6666 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6669 if (available_money > toLocalCurrency ($2500))
6672 Add a lot of aggravation and time;
6674 if (a similar board exists) { /* hopefully... */
6675 cp -a board/<similar> board/<myboard>
6676 cp include/configs/<similar>.h include/configs/<myboard>.h
6678 Create your own board support subdirectory;
6679 Create your own board include/configs/<myboard>.h file;
6681 Edit new board/<myboard> files
6682 Edit new include/configs/<myboard>.h
6687 Add / modify source code;
6691 email("Hi, I am having problems...");
6693 Send patch file to the U-Boot email list;
6694 if (reasonable critiques)
6695 Incorporate improvements from email list code review;
6697 Defend code as written;
6703 void no_more_time (int sig)
6712 All contributions to U-Boot should conform to the Linux kernel
6713 coding style; see the file "Documentation/CodingStyle" and the script
6714 "scripts/Lindent" in your Linux kernel source directory.
6716 Source files originating from a different project (for example the
6717 MTD subsystem) are generally exempt from these guidelines and are not
6718 reformatted to ease subsequent migration to newer versions of those
6721 Please note that U-Boot is implemented in C (and to some small parts in
6722 Assembler); no C++ is used, so please do not use C++ style comments (//)
6725 Please also stick to the following formatting rules:
6726 - remove any trailing white space
6727 - use TAB characters for indentation and vertical alignment, not spaces
6728 - make sure NOT to use DOS '\r\n' line feeds
6729 - do not add more than 2 consecutive empty lines to source files
6730 - do not add trailing empty lines to source files
6732 Submissions which do not conform to the standards may be returned
6733 with a request to reformat the changes.
6739 Since the number of patches for U-Boot is growing, we need to
6740 establish some rules. Submissions which do not conform to these rules
6741 may be rejected, even when they contain important and valuable stuff.
6743 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6745 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6746 see http://lists.denx.de/mailman/listinfo/u-boot
6748 When you send a patch, please include the following information with
6751 * For bug fixes: a description of the bug and how your patch fixes
6752 this bug. Please try to include a way of demonstrating that the
6753 patch actually fixes something.
6755 * For new features: a description of the feature and your
6758 * A CHANGELOG entry as plaintext (separate from the patch)
6760 * For major contributions, your entry to the CREDITS file
6762 * When you add support for a new board, don't forget to add a
6763 maintainer e-mail address to the boards.cfg file, too.
6765 * If your patch adds new configuration options, don't forget to
6766 document these in the README file.
6768 * The patch itself. If you are using git (which is *strongly*
6769 recommended) you can easily generate the patch using the
6770 "git format-patch". If you then use "git send-email" to send it to
6771 the U-Boot mailing list, you will avoid most of the common problems
6772 with some other mail clients.
6774 If you cannot use git, use "diff -purN OLD NEW". If your version of
6775 diff does not support these options, then get the latest version of
6778 The current directory when running this command shall be the parent
6779 directory of the U-Boot source tree (i. e. please make sure that
6780 your patch includes sufficient directory information for the
6783 We prefer patches as plain text. MIME attachments are discouraged,
6784 and compressed attachments must not be used.
6786 * If one logical set of modifications affects or creates several
6787 files, all these changes shall be submitted in a SINGLE patch file.
6789 * Changesets that contain different, unrelated modifications shall be
6790 submitted as SEPARATE patches, one patch per changeset.
6795 * Before sending the patch, run the MAKEALL script on your patched
6796 source tree and make sure that no errors or warnings are reported
6797 for any of the boards.
6799 * Keep your modifications to the necessary minimum: A patch
6800 containing several unrelated changes or arbitrary reformats will be
6801 returned with a request to re-formatting / split it.
6803 * If you modify existing code, make sure that your new code does not
6804 add to the memory footprint of the code ;-) Small is beautiful!
6805 When adding new features, these should compile conditionally only
6806 (using #ifdef), and the resulting code with the new feature
6807 disabled must not need more memory than the old code without your
6810 * Remember that there is a size limit of 100 kB per message on the
6811 u-boot mailing list. Bigger patches will be moderated. If they are
6812 reasonable and not too big, they will be acknowledged. But patches
6813 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob