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.
1495 CONFIG_E1000_FALLBACK_MAC
1496 default MAC for empty EEPROM after production.
1499 Support for Intel 82557/82559/82559ER chips.
1500 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1501 write routine for first time initialisation.
1504 Support for Digital 2114x chips.
1505 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1506 modem chip initialisation (KS8761/QS6611).
1509 Support for National dp83815 chips.
1512 Support for National dp8382[01] gigabit chips.
1514 - NETWORK Support (other):
1516 CONFIG_DRIVER_AT91EMAC
1517 Support for AT91RM9200 EMAC.
1520 Define this to use reduced MII inteface
1522 CONFIG_DRIVER_AT91EMAC_QUIET
1523 If this defined, the driver is quiet.
1524 The driver doen't show link status messages.
1526 CONFIG_CALXEDA_XGMAC
1527 Support for the Calxeda XGMAC device
1530 Support for SMSC's LAN91C96 chips.
1532 CONFIG_LAN91C96_BASE
1533 Define this to hold the physical address
1534 of the LAN91C96's I/O space
1536 CONFIG_LAN91C96_USE_32_BIT
1537 Define this to enable 32 bit addressing
1540 Support for SMSC's LAN91C111 chip
1542 CONFIG_SMC91111_BASE
1543 Define this to hold the physical address
1544 of the device (I/O space)
1546 CONFIG_SMC_USE_32_BIT
1547 Define this if data bus is 32 bits
1549 CONFIG_SMC_USE_IOFUNCS
1550 Define this to use i/o functions instead of macros
1551 (some hardware wont work with macros)
1553 CONFIG_DRIVER_TI_EMAC
1554 Support for davinci emac
1556 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1557 Define this if you have more then 3 PHYs.
1560 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1562 CONFIG_FTGMAC100_EGIGA
1563 Define this to use GE link update with gigabit PHY.
1564 Define this if FTGMAC100 is connected to gigabit PHY.
1565 If your system has 10/100 PHY only, it might not occur
1566 wrong behavior. Because PHY usually return timeout or
1567 useless data when polling gigabit status and gigabit
1568 control registers. This behavior won't affect the
1569 correctnessof 10/100 link speed update.
1572 Support for SMSC's LAN911x and LAN921x chips
1575 Define this to hold the physical address
1576 of the device (I/O space)
1578 CONFIG_SMC911X_32_BIT
1579 Define this if data bus is 32 bits
1581 CONFIG_SMC911X_16_BIT
1582 Define this if data bus is 16 bits. If your processor
1583 automatically converts one 32 bit word to two 16 bit
1584 words you may also try CONFIG_SMC911X_32_BIT.
1587 Support for Renesas on-chip Ethernet controller
1589 CONFIG_SH_ETHER_USE_PORT
1590 Define the number of ports to be used
1592 CONFIG_SH_ETHER_PHY_ADDR
1593 Define the ETH PHY's address
1595 CONFIG_SH_ETHER_CACHE_WRITEBACK
1596 If this option is set, the driver enables cache flush.
1600 Support for PWM modul on the imx6.
1604 Support TPM devices.
1607 Support for i2c bus TPM devices. Only one device
1608 per system is supported at this time.
1610 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1611 Define the the i2c bus number for the TPM device
1613 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1614 Define the TPM's address on the i2c bus
1616 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1617 Define the burst count bytes upper limit
1619 CONFIG_TPM_ATMEL_TWI
1620 Support for Atmel TWI TPM device. Requires I2C support.
1623 Support for generic parallel port TPM devices. Only one device
1624 per system is supported at this time.
1626 CONFIG_TPM_TIS_BASE_ADDRESS
1627 Base address where the generic TPM device is mapped
1628 to. Contemporary x86 systems usually map it at
1632 Add tpm monitor functions.
1633 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1634 provides monitor access to authorized functions.
1637 Define this to enable the TPM support library which provides
1638 functional interfaces to some TPM commands.
1639 Requires support for a TPM device.
1641 CONFIG_TPM_AUTH_SESSIONS
1642 Define this to enable authorized functions in the TPM library.
1643 Requires CONFIG_TPM and CONFIG_SHA1.
1646 At the moment only the UHCI host controller is
1647 supported (PIP405, MIP405, MPC5200); define
1648 CONFIG_USB_UHCI to enable it.
1649 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1650 and define CONFIG_USB_STORAGE to enable the USB
1653 Supported are USB Keyboards and USB Floppy drives
1655 MPC5200 USB requires additional defines:
1657 for 528 MHz Clock: 0x0001bbbb
1661 for differential drivers: 0x00001000
1662 for single ended drivers: 0x00005000
1663 for differential drivers on PSC3: 0x00000100
1664 for single ended drivers on PSC3: 0x00004100
1665 CONFIG_SYS_USB_EVENT_POLL
1666 May be defined to allow interrupt polling
1667 instead of using asynchronous interrupts
1669 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1670 txfilltuning field in the EHCI controller on reset.
1672 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1673 HW module registers.
1676 Define the below if you wish to use the USB console.
1677 Once firmware is rebuilt from a serial console issue the
1678 command "setenv stdin usbtty; setenv stdout usbtty" and
1679 attach your USB cable. The Unix command "dmesg" should print
1680 it has found a new device. The environment variable usbtty
1681 can be set to gserial or cdc_acm to enable your device to
1682 appear to a USB host as a Linux gserial device or a
1683 Common Device Class Abstract Control Model serial device.
1684 If you select usbtty = gserial you should be able to enumerate
1686 # modprobe usbserial vendor=0xVendorID product=0xProductID
1687 else if using cdc_acm, simply setting the environment
1688 variable usbtty to be cdc_acm should suffice. The following
1689 might be defined in YourBoardName.h
1692 Define this to build a UDC device
1695 Define this to have a tty type of device available to
1696 talk to the UDC device
1699 Define this to enable the high speed support for usb
1700 device and usbtty. If this feature is enabled, a routine
1701 int is_usbd_high_speed(void)
1702 also needs to be defined by the driver to dynamically poll
1703 whether the enumeration has succeded at high speed or full
1706 CONFIG_SYS_CONSOLE_IS_IN_ENV
1707 Define this if you want stdin, stdout &/or stderr to
1711 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1712 Derive USB clock from external clock "blah"
1713 - CONFIG_SYS_USB_EXTC_CLK 0x02
1715 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1716 Derive USB clock from brgclk
1717 - CONFIG_SYS_USB_BRG_CLK 0x04
1719 If you have a USB-IF assigned VendorID then you may wish to
1720 define your own vendor specific values either in BoardName.h
1721 or directly in usbd_vendor_info.h. If you don't define
1722 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1723 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1724 should pretend to be a Linux device to it's target host.
1726 CONFIG_USBD_MANUFACTURER
1727 Define this string as the name of your company for
1728 - CONFIG_USBD_MANUFACTURER "my company"
1730 CONFIG_USBD_PRODUCT_NAME
1731 Define this string as the name of your product
1732 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1734 CONFIG_USBD_VENDORID
1735 Define this as your assigned Vendor ID from the USB
1736 Implementors Forum. This *must* be a genuine Vendor ID
1737 to avoid polluting the USB namespace.
1738 - CONFIG_USBD_VENDORID 0xFFFF
1740 CONFIG_USBD_PRODUCTID
1741 Define this as the unique Product ID
1743 - CONFIG_USBD_PRODUCTID 0xFFFF
1745 - ULPI Layer Support:
1746 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1747 the generic ULPI layer. The generic layer accesses the ULPI PHY
1748 via the platform viewport, so you need both the genric layer and
1749 the viewport enabled. Currently only Chipidea/ARC based
1750 viewport is supported.
1751 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1752 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1753 If your ULPI phy needs a different reference clock than the
1754 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1755 the appropriate value in Hz.
1758 The MMC controller on the Intel PXA is supported. To
1759 enable this define CONFIG_MMC. The MMC can be
1760 accessed from the boot prompt by mapping the device
1761 to physical memory similar to flash. Command line is
1762 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1763 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1766 Support for Renesas on-chip MMCIF controller
1768 CONFIG_SH_MMCIF_ADDR
1769 Define the base address of MMCIF registers
1772 Define the clock frequency for MMCIF
1775 Enable the generic MMC driver
1777 CONFIG_SUPPORT_EMMC_BOOT
1778 Enable some additional features of the eMMC boot partitions.
1780 CONFIG_SUPPORT_EMMC_RPMB
1781 Enable the commands for reading, writing and programming the
1782 key for the Replay Protection Memory Block partition in eMMC.
1784 - USB Device Firmware Update (DFU) class support:
1785 CONFIG_USB_FUNCTION_DFU
1786 This enables the USB portion of the DFU USB class
1789 This enables the command "dfu" which is used to have
1790 U-Boot create a DFU class device via USB. This command
1791 requires that the "dfu_alt_info" environment variable be
1792 set and define the alt settings to expose to the host.
1795 This enables support for exposing (e)MMC devices via DFU.
1798 This enables support for exposing NAND devices via DFU.
1801 This enables support for exposing RAM via DFU.
1802 Note: DFU spec refer to non-volatile memory usage, but
1803 allow usages beyond the scope of spec - here RAM usage,
1804 one that would help mostly the developer.
1806 CONFIG_SYS_DFU_DATA_BUF_SIZE
1807 Dfu transfer uses a buffer before writing data to the
1808 raw storage device. Make the size (in bytes) of this buffer
1809 configurable. The size of this buffer is also configurable
1810 through the "dfu_bufsiz" environment variable.
1812 CONFIG_SYS_DFU_MAX_FILE_SIZE
1813 When updating files rather than the raw storage device,
1814 we use a static buffer to copy the file into and then write
1815 the buffer once we've been given the whole file. Define
1816 this to the maximum filesize (in bytes) for the buffer.
1817 Default is 4 MiB if undefined.
1819 DFU_DEFAULT_POLL_TIMEOUT
1820 Poll timeout [ms], is the timeout a device can send to the
1821 host. The host must wait for this timeout before sending
1822 a subsequent DFU_GET_STATUS request to the device.
1824 DFU_MANIFEST_POLL_TIMEOUT
1825 Poll timeout [ms], which the device sends to the host when
1826 entering dfuMANIFEST state. Host waits this timeout, before
1827 sending again an USB request to the device.
1829 - USB Device Android Fastboot support:
1830 CONFIG_USB_FUNCTION_FASTBOOT
1831 This enables the USB part of the fastboot gadget
1834 This enables the command "fastboot" which enables the Android
1835 fastboot mode for the platform's USB device. Fastboot is a USB
1836 protocol for downloading images, flashing and device control
1837 used on Android devices.
1838 See doc/README.android-fastboot for more information.
1840 CONFIG_ANDROID_BOOT_IMAGE
1841 This enables support for booting images which use the Android
1842 image format header.
1844 CONFIG_FASTBOOT_BUF_ADDR
1845 The fastboot protocol requires a large memory buffer for
1846 downloads. Define this to the starting RAM address to use for
1849 CONFIG_FASTBOOT_BUF_SIZE
1850 The fastboot protocol requires a large memory buffer for
1851 downloads. This buffer should be as large as possible for a
1852 platform. Define this to the size available RAM for fastboot.
1854 CONFIG_FASTBOOT_FLASH
1855 The fastboot protocol includes a "flash" command for writing
1856 the downloaded image to a non-volatile storage device. Define
1857 this to enable the "fastboot flash" command.
1859 CONFIG_FASTBOOT_FLASH_MMC_DEV
1860 The fastboot "flash" command requires additional information
1861 regarding the non-volatile storage device. Define this to
1862 the eMMC device that fastboot should use to store the image.
1864 CONFIG_FASTBOOT_GPT_NAME
1865 The fastboot "flash" command supports writing the downloaded
1866 image to the Protective MBR and the Primary GUID Partition
1867 Table. (Additionally, this downloaded image is post-processed
1868 to generate and write the Backup GUID Partition Table.)
1869 This occurs when the specified "partition name" on the
1870 "fastboot flash" command line matches this value.
1871 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1873 - Journaling Flash filesystem support:
1874 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1875 CONFIG_JFFS2_NAND_DEV
1876 Define these for a default partition on a NAND device
1878 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1879 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1880 Define these for a default partition on a NOR device
1882 CONFIG_SYS_JFFS_CUSTOM_PART
1883 Define this to create an own partition. You have to provide a
1884 function struct part_info* jffs2_part_info(int part_num)
1886 If you define only one JFFS2 partition you may also want to
1887 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1888 to disable the command chpart. This is the default when you
1889 have not defined a custom partition
1891 - FAT(File Allocation Table) filesystem write function support:
1894 Define this to enable support for saving memory data as a
1895 file in FAT formatted partition.
1897 This will also enable the command "fatwrite" enabling the
1898 user to write files to FAT.
1900 CBFS (Coreboot Filesystem) support
1903 Define this to enable support for reading from a Coreboot
1904 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1907 - FAT(File Allocation Table) filesystem cluster size:
1908 CONFIG_FS_FAT_MAX_CLUSTSIZE
1910 Define the max cluster size for fat operations else
1911 a default value of 65536 will be defined.
1916 Define this to enable standard (PC-Style) keyboard
1920 Standard PC keyboard driver with US (is default) and
1921 GERMAN key layout (switch via environment 'keymap=de') support.
1922 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1923 for cfb_console. Supports cursor blinking.
1926 Enables a Chrome OS keyboard using the CROS_EC interface.
1927 This uses CROS_EC to communicate with a second microcontroller
1928 which provides key scans on request.
1933 Define this to enable video support (for output to
1936 CONFIG_VIDEO_CT69000
1938 Enable Chips & Technologies 69000 Video chip
1940 CONFIG_VIDEO_SMI_LYNXEM
1941 Enable Silicon Motion SMI 712/710/810 Video chip. The
1942 video output is selected via environment 'videoout'
1943 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1946 For the CT69000 and SMI_LYNXEM drivers, videomode is
1947 selected via environment 'videomode'. Two different ways
1949 - "videomode=num" 'num' is a standard LiLo mode numbers.
1950 Following standard modes are supported (* is default):
1952 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1953 -------------+---------------------------------------------
1954 8 bits | 0x301* 0x303 0x305 0x161 0x307
1955 15 bits | 0x310 0x313 0x316 0x162 0x319
1956 16 bits | 0x311 0x314 0x317 0x163 0x31A
1957 24 bits | 0x312 0x315 0x318 ? 0x31B
1958 -------------+---------------------------------------------
1959 (i.e. setenv videomode 317; saveenv; reset;)
1961 - "videomode=bootargs" all the video parameters are parsed
1962 from the bootargs. (See drivers/video/videomodes.c)
1965 CONFIG_VIDEO_SED13806
1966 Enable Epson SED13806 driver. This driver supports 8bpp
1967 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1968 or CONFIG_VIDEO_SED13806_16BPP
1971 Enable the Freescale DIU video driver. Reference boards for
1972 SOCs that have a DIU should define this macro to enable DIU
1973 support, and should also define these other macros:
1979 CONFIG_VIDEO_SW_CURSOR
1980 CONFIG_VGA_AS_SINGLE_DEVICE
1982 CONFIG_VIDEO_BMP_LOGO
1984 The DIU driver will look for the 'video-mode' environment
1985 variable, and if defined, enable the DIU as a console during
1986 boot. See the documentation file README.video for a
1987 description of this variable.
1993 Define this to enable a custom keyboard support.
1994 This simply calls drv_keyboard_init() which must be
1995 defined in your board-specific files.
1996 The only board using this so far is RBC823.
1998 - LCD Support: CONFIG_LCD
2000 Define this to enable LCD support (for output to LCD
2001 display); also select one of the supported displays
2002 by defining one of these:
2006 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2008 CONFIG_NEC_NL6448AC33:
2010 NEC NL6448AC33-18. Active, color, single scan.
2012 CONFIG_NEC_NL6448BC20
2014 NEC NL6448BC20-08. 6.5", 640x480.
2015 Active, color, single scan.
2017 CONFIG_NEC_NL6448BC33_54
2019 NEC NL6448BC33-54. 10.4", 640x480.
2020 Active, color, single scan.
2024 Sharp 320x240. Active, color, single scan.
2025 It isn't 16x9, and I am not sure what it is.
2027 CONFIG_SHARP_LQ64D341
2029 Sharp LQ64D341 display, 640x480.
2030 Active, color, single scan.
2034 HLD1045 display, 640x480.
2035 Active, color, single scan.
2039 Optrex CBL50840-2 NF-FW 99 22 M5
2041 Hitachi LMG6912RPFC-00T
2045 320x240. Black & white.
2047 Normally display is black on white background; define
2048 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2050 CONFIG_LCD_ALIGNMENT
2052 Normally the LCD is page-aligned (typically 4KB). If this is
2053 defined then the LCD will be aligned to this value instead.
2054 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2055 here, since it is cheaper to change data cache settings on
2056 a per-section basis.
2058 CONFIG_CONSOLE_SCROLL_LINES
2060 When the console need to be scrolled, this is the number of
2061 lines to scroll by. It defaults to 1. Increasing this makes
2062 the console jump but can help speed up operation when scrolling
2067 Sometimes, for example if the display is mounted in portrait
2068 mode or even if it's mounted landscape but rotated by 180degree,
2069 we need to rotate our content of the display relative to the
2070 framebuffer, so that user can read the messages which are
2072 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2073 initialized with a given rotation from "vl_rot" out of
2074 "vidinfo_t" which is provided by the board specific code.
2075 The value for vl_rot is coded as following (matching to
2076 fbcon=rotate:<n> linux-kernel commandline):
2077 0 = no rotation respectively 0 degree
2078 1 = 90 degree rotation
2079 2 = 180 degree rotation
2080 3 = 270 degree rotation
2082 If CONFIG_LCD_ROTATION is not defined, the console will be
2083 initialized with 0degree rotation.
2087 Support drawing of RLE8-compressed bitmaps on the LCD.
2091 Enables an 'i2c edid' command which can read EDID
2092 information over I2C from an attached LCD display.
2094 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2096 If this option is set, the environment is checked for
2097 a variable "splashimage". If found, the usual display
2098 of logo, copyright and system information on the LCD
2099 is suppressed and the BMP image at the address
2100 specified in "splashimage" is loaded instead. The
2101 console is redirected to the "nulldev", too. This
2102 allows for a "silent" boot where a splash screen is
2103 loaded very quickly after power-on.
2105 CONFIG_SPLASHIMAGE_GUARD
2107 If this option is set, then U-Boot will prevent the environment
2108 variable "splashimage" from being set to a problematic address
2109 (see README.displaying-bmps).
2110 This option is useful for targets where, due to alignment
2111 restrictions, an improperly aligned BMP image will cause a data
2112 abort. If you think you will not have problems with unaligned
2113 accesses (for example because your toolchain prevents them)
2114 there is no need to set this option.
2116 CONFIG_SPLASH_SCREEN_ALIGN
2118 If this option is set the splash image can be freely positioned
2119 on the screen. Environment variable "splashpos" specifies the
2120 position as "x,y". If a positive number is given it is used as
2121 number of pixel from left/top. If a negative number is given it
2122 is used as number of pixel from right/bottom. You can also
2123 specify 'm' for centering the image.
2126 setenv splashpos m,m
2127 => image at center of screen
2129 setenv splashpos 30,20
2130 => image at x = 30 and y = 20
2132 setenv splashpos -10,m
2133 => vertically centered image
2134 at x = dspWidth - bmpWidth - 9
2136 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2138 If this option is set, additionally to standard BMP
2139 images, gzipped BMP images can be displayed via the
2140 splashscreen support or the bmp command.
2142 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2144 If this option is set, 8-bit RLE compressed BMP images
2145 can be displayed via the splashscreen support or the
2148 - Do compressing for memory range:
2151 If this option is set, it would use zlib deflate method
2152 to compress the specified memory at its best effort.
2154 - Compression support:
2157 Enabled by default to support gzip compressed images.
2161 If this option is set, support for bzip2 compressed
2162 images is included. If not, only uncompressed and gzip
2163 compressed images are supported.
2165 NOTE: the bzip2 algorithm requires a lot of RAM, so
2166 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2171 If this option is set, support for lzma compressed
2174 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2175 requires an amount of dynamic memory that is given by the
2178 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2180 Where lc and lp stand for, respectively, Literal context bits
2181 and Literal pos bits.
2183 This value is upper-bounded by 14MB in the worst case. Anyway,
2184 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2185 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2186 a very small buffer.
2188 Use the lzmainfo tool to determinate the lc and lp values and
2189 then calculate the amount of needed dynamic memory (ensuring
2190 the appropriate CONFIG_SYS_MALLOC_LEN value).
2194 If this option is set, support for LZO compressed images
2200 The address of PHY on MII bus.
2202 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2204 The clock frequency of the MII bus
2208 If this option is set, support for speed/duplex
2209 detection of gigabit PHY is included.
2211 CONFIG_PHY_RESET_DELAY
2213 Some PHY like Intel LXT971A need extra delay after
2214 reset before any MII register access is possible.
2215 For such PHY, set this option to the usec delay
2216 required. (minimum 300usec for LXT971A)
2218 CONFIG_PHY_CMD_DELAY (ppc4xx)
2220 Some PHY like Intel LXT971A need extra delay after
2221 command issued before MII status register can be read
2226 Define a default value for the IP address to use for
2227 the default Ethernet interface, in case this is not
2228 determined through e.g. bootp.
2229 (Environment variable "ipaddr")
2231 - Server IP address:
2234 Defines a default value for the IP address of a TFTP
2235 server to contact when using the "tftboot" command.
2236 (Environment variable "serverip")
2238 CONFIG_KEEP_SERVERADDR
2240 Keeps the server's MAC address, in the env 'serveraddr'
2241 for passing to bootargs (like Linux's netconsole option)
2243 - Gateway IP address:
2246 Defines a default value for the IP address of the
2247 default router where packets to other networks are
2249 (Environment variable "gatewayip")
2254 Defines a default value for the subnet mask (or
2255 routing prefix) which is used to determine if an IP
2256 address belongs to the local subnet or needs to be
2257 forwarded through a router.
2258 (Environment variable "netmask")
2260 - Multicast TFTP Mode:
2263 Defines whether you want to support multicast TFTP as per
2264 rfc-2090; for example to work with atftp. Lets lots of targets
2265 tftp down the same boot image concurrently. Note: the Ethernet
2266 driver in use must provide a function: mcast() to join/leave a
2269 - BOOTP Recovery Mode:
2270 CONFIG_BOOTP_RANDOM_DELAY
2272 If you have many targets in a network that try to
2273 boot using BOOTP, you may want to avoid that all
2274 systems send out BOOTP requests at precisely the same
2275 moment (which would happen for instance at recovery
2276 from a power failure, when all systems will try to
2277 boot, thus flooding the BOOTP server. Defining
2278 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2279 inserted before sending out BOOTP requests. The
2280 following delays are inserted then:
2282 1st BOOTP request: delay 0 ... 1 sec
2283 2nd BOOTP request: delay 0 ... 2 sec
2284 3rd BOOTP request: delay 0 ... 4 sec
2286 BOOTP requests: delay 0 ... 8 sec
2288 CONFIG_BOOTP_ID_CACHE_SIZE
2290 BOOTP packets are uniquely identified using a 32-bit ID. The
2291 server will copy the ID from client requests to responses and
2292 U-Boot will use this to determine if it is the destination of
2293 an incoming response. Some servers will check that addresses
2294 aren't in use before handing them out (usually using an ARP
2295 ping) and therefore take up to a few hundred milliseconds to
2296 respond. Network congestion may also influence the time it
2297 takes for a response to make it back to the client. If that
2298 time is too long, U-Boot will retransmit requests. In order
2299 to allow earlier responses to still be accepted after these
2300 retransmissions, U-Boot's BOOTP client keeps a small cache of
2301 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2302 cache. The default is to keep IDs for up to four outstanding
2303 requests. Increasing this will allow U-Boot to accept offers
2304 from a BOOTP client in networks with unusually high latency.
2306 - BOOTP Random transaction ID:
2307 CONFIG_BOOTP_RANDOM_ID
2309 The standard algorithm to generate a DHCP/BOOTP transaction ID
2310 by using the MAC address and the current time stamp may not
2311 quite unlikely produce duplicate transaction IDs from different
2312 clients in the same network. This option creates a transaction
2313 ID using the rand() function. Provided that the RNG has been
2314 seeded well, this should guarantee unique transaction IDs
2317 - DHCP Advanced Options:
2318 You can fine tune the DHCP functionality by defining
2319 CONFIG_BOOTP_* symbols:
2321 CONFIG_BOOTP_SUBNETMASK
2322 CONFIG_BOOTP_GATEWAY
2323 CONFIG_BOOTP_HOSTNAME
2324 CONFIG_BOOTP_NISDOMAIN
2325 CONFIG_BOOTP_BOOTPATH
2326 CONFIG_BOOTP_BOOTFILESIZE
2329 CONFIG_BOOTP_SEND_HOSTNAME
2330 CONFIG_BOOTP_NTPSERVER
2331 CONFIG_BOOTP_TIMEOFFSET
2332 CONFIG_BOOTP_VENDOREX
2333 CONFIG_BOOTP_MAY_FAIL
2335 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2336 environment variable, not the BOOTP server.
2338 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2339 after the configured retry count, the call will fail
2340 instead of starting over. This can be used to fail over
2341 to Link-local IP address configuration if the DHCP server
2344 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2345 serverip from a DHCP server, it is possible that more
2346 than one DNS serverip is offered to the client.
2347 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2348 serverip will be stored in the additional environment
2349 variable "dnsip2". The first DNS serverip is always
2350 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2353 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2354 to do a dynamic update of a DNS server. To do this, they
2355 need the hostname of the DHCP requester.
2356 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2357 of the "hostname" environment variable is passed as
2358 option 12 to the DHCP server.
2360 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2362 A 32bit value in microseconds for a delay between
2363 receiving a "DHCP Offer" and sending the "DHCP Request".
2364 This fixes a problem with certain DHCP servers that don't
2365 respond 100% of the time to a "DHCP request". E.g. On an
2366 AT91RM9200 processor running at 180MHz, this delay needed
2367 to be *at least* 15,000 usec before a Windows Server 2003
2368 DHCP server would reply 100% of the time. I recommend at
2369 least 50,000 usec to be safe. The alternative is to hope
2370 that one of the retries will be successful but note that
2371 the DHCP timeout and retry process takes a longer than
2374 - Link-local IP address negotiation:
2375 Negotiate with other link-local clients on the local network
2376 for an address that doesn't require explicit configuration.
2377 This is especially useful if a DHCP server cannot be guaranteed
2378 to exist in all environments that the device must operate.
2380 See doc/README.link-local for more information.
2383 CONFIG_CDP_DEVICE_ID
2385 The device id used in CDP trigger frames.
2387 CONFIG_CDP_DEVICE_ID_PREFIX
2389 A two character string which is prefixed to the MAC address
2394 A printf format string which contains the ascii name of
2395 the port. Normally is set to "eth%d" which sets
2396 eth0 for the first Ethernet, eth1 for the second etc.
2398 CONFIG_CDP_CAPABILITIES
2400 A 32bit integer which indicates the device capabilities;
2401 0x00000010 for a normal host which does not forwards.
2405 An ascii string containing the version of the software.
2409 An ascii string containing the name of the platform.
2413 A 32bit integer sent on the trigger.
2415 CONFIG_CDP_POWER_CONSUMPTION
2417 A 16bit integer containing the power consumption of the
2418 device in .1 of milliwatts.
2420 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2422 A byte containing the id of the VLAN.
2424 - Status LED: CONFIG_STATUS_LED
2426 Several configurations allow to display the current
2427 status using a LED. For instance, the LED will blink
2428 fast while running U-Boot code, stop blinking as
2429 soon as a reply to a BOOTP request was received, and
2430 start blinking slow once the Linux kernel is running
2431 (supported by a status LED driver in the Linux
2432 kernel). Defining CONFIG_STATUS_LED enables this
2438 The status LED can be connected to a GPIO pin.
2439 In such cases, the gpio_led driver can be used as a
2440 status LED backend implementation. Define CONFIG_GPIO_LED
2441 to include the gpio_led driver in the U-Boot binary.
2443 CONFIG_GPIO_LED_INVERTED_TABLE
2444 Some GPIO connected LEDs may have inverted polarity in which
2445 case the GPIO high value corresponds to LED off state and
2446 GPIO low value corresponds to LED on state.
2447 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2448 with a list of GPIO LEDs that have inverted polarity.
2450 - CAN Support: CONFIG_CAN_DRIVER
2452 Defining CONFIG_CAN_DRIVER enables CAN driver support
2453 on those systems that support this (optional)
2454 feature, like the TQM8xxL modules.
2456 - I2C Support: CONFIG_SYS_I2C
2458 This enable the NEW i2c subsystem, and will allow you to use
2459 i2c commands at the u-boot command line (as long as you set
2460 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2461 based realtime clock chips or other i2c devices. See
2462 common/cmd_i2c.c for a description of the command line
2465 ported i2c driver to the new framework:
2466 - drivers/i2c/soft_i2c.c:
2467 - activate first bus with CONFIG_SYS_I2C_SOFT define
2468 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2469 for defining speed and slave address
2470 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2471 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2472 for defining speed and slave address
2473 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2474 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2475 for defining speed and slave address
2476 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2477 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2478 for defining speed and slave address
2480 - drivers/i2c/fsl_i2c.c:
2481 - activate i2c driver with CONFIG_SYS_I2C_FSL
2482 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2483 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2484 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2486 - If your board supports a second fsl i2c bus, define
2487 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2488 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2489 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2492 - drivers/i2c/tegra_i2c.c:
2493 - activate this driver with CONFIG_SYS_I2C_TEGRA
2494 - This driver adds 4 i2c buses with a fix speed from
2495 100000 and the slave addr 0!
2497 - drivers/i2c/ppc4xx_i2c.c
2498 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2499 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2500 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2502 - drivers/i2c/i2c_mxc.c
2503 - activate this driver with CONFIG_SYS_I2C_MXC
2504 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2505 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2506 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2507 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2508 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2509 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2510 If those defines are not set, default value is 100000
2511 for speed, and 0 for slave.
2512 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2513 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2515 - drivers/i2c/rcar_i2c.c:
2516 - activate this driver with CONFIG_SYS_I2C_RCAR
2517 - This driver adds 4 i2c buses
2519 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2520 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2521 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2522 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2523 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2524 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2525 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2526 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2527 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2529 - drivers/i2c/sh_i2c.c:
2530 - activate this driver with CONFIG_SYS_I2C_SH
2531 - This driver adds from 2 to 5 i2c buses
2533 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2534 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2535 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2536 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2537 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2538 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2539 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2540 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2541 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2542 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2543 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2544 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2545 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2547 - drivers/i2c/omap24xx_i2c.c
2548 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2549 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2550 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2551 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2552 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2553 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2554 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2555 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2556 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2557 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2558 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2560 - drivers/i2c/zynq_i2c.c
2561 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2562 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2563 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2565 - drivers/i2c/s3c24x0_i2c.c:
2566 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2567 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2568 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2569 with a fix speed from 100000 and the slave addr 0!
2571 - drivers/i2c/ihs_i2c.c
2572 - activate this driver with CONFIG_SYS_I2C_IHS
2573 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2574 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2575 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2576 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2577 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2578 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2579 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2580 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2581 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2582 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2583 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2584 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2588 CONFIG_SYS_NUM_I2C_BUSES
2589 Hold the number of i2c buses you want to use. If you
2590 don't use/have i2c muxes on your i2c bus, this
2591 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2594 CONFIG_SYS_I2C_DIRECT_BUS
2595 define this, if you don't use i2c muxes on your hardware.
2596 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2599 CONFIG_SYS_I2C_MAX_HOPS
2600 define how many muxes are maximal consecutively connected
2601 on one i2c bus. If you not use i2c muxes, omit this
2604 CONFIG_SYS_I2C_BUSES
2605 hold a list of buses you want to use, only used if
2606 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2607 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2608 CONFIG_SYS_NUM_I2C_BUSES = 9:
2610 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2612 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2613 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2614 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2615 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2616 {1, {I2C_NULL_HOP}}, \
2617 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2618 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2622 bus 0 on adapter 0 without a mux
2623 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2624 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2625 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2626 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2627 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2628 bus 6 on adapter 1 without a mux
2629 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2630 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2632 If you do not have i2c muxes on your board, omit this define.
2634 - Legacy I2C Support: CONFIG_HARD_I2C
2636 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2637 provides the following compelling advantages:
2639 - more than one i2c adapter is usable
2640 - approved multibus support
2641 - better i2c mux support
2643 ** Please consider updating your I2C driver now. **
2645 These enable legacy I2C serial bus commands. Defining
2646 CONFIG_HARD_I2C will include the appropriate I2C driver
2647 for the selected CPU.
2649 This will allow you to use i2c commands at the u-boot
2650 command line (as long as you set CONFIG_CMD_I2C in
2651 CONFIG_COMMANDS) and communicate with i2c based realtime
2652 clock chips. See common/cmd_i2c.c for a description of the
2653 command line interface.
2655 CONFIG_HARD_I2C selects a hardware I2C controller.
2657 There are several other quantities that must also be
2658 defined when you define CONFIG_HARD_I2C.
2660 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2661 to be the frequency (in Hz) at which you wish your i2c bus
2662 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2663 the CPU's i2c node address).
2665 Now, the u-boot i2c code for the mpc8xx
2666 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2667 and so its address should therefore be cleared to 0 (See,
2668 eg, MPC823e User's Manual p.16-473). So, set
2669 CONFIG_SYS_I2C_SLAVE to 0.
2671 CONFIG_SYS_I2C_INIT_MPC5XXX
2673 When a board is reset during an i2c bus transfer
2674 chips might think that the current transfer is still
2675 in progress. Reset the slave devices by sending start
2676 commands until the slave device responds.
2678 That's all that's required for CONFIG_HARD_I2C.
2680 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2681 then the following macros need to be defined (examples are
2682 from include/configs/lwmon.h):
2686 (Optional). Any commands necessary to enable the I2C
2687 controller or configure ports.
2689 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2693 (Only for MPC8260 CPU). The I/O port to use (the code
2694 assumes both bits are on the same port). Valid values
2695 are 0..3 for ports A..D.
2699 The code necessary to make the I2C data line active
2700 (driven). If the data line is open collector, this
2703 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2707 The code necessary to make the I2C data line tri-stated
2708 (inactive). If the data line is open collector, this
2711 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2715 Code that returns true if the I2C data line is high,
2718 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2722 If <bit> is true, sets the I2C data line high. If it
2723 is false, it clears it (low).
2725 eg: #define I2C_SDA(bit) \
2726 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2727 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2731 If <bit> is true, sets the I2C clock line high. If it
2732 is false, it clears it (low).
2734 eg: #define I2C_SCL(bit) \
2735 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2736 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2740 This delay is invoked four times per clock cycle so this
2741 controls the rate of data transfer. The data rate thus
2742 is 1 / (I2C_DELAY * 4). Often defined to be something
2745 #define I2C_DELAY udelay(2)
2747 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2749 If your arch supports the generic GPIO framework (asm/gpio.h),
2750 then you may alternatively define the two GPIOs that are to be
2751 used as SCL / SDA. Any of the previous I2C_xxx macros will
2752 have GPIO-based defaults assigned to them as appropriate.
2754 You should define these to the GPIO value as given directly to
2755 the generic GPIO functions.
2757 CONFIG_SYS_I2C_INIT_BOARD
2759 When a board is reset during an i2c bus transfer
2760 chips might think that the current transfer is still
2761 in progress. On some boards it is possible to access
2762 the i2c SCLK line directly, either by using the
2763 processor pin as a GPIO or by having a second pin
2764 connected to the bus. If this option is defined a
2765 custom i2c_init_board() routine in boards/xxx/board.c
2766 is run early in the boot sequence.
2768 CONFIG_SYS_I2C_BOARD_LATE_INIT
2770 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2771 defined a custom i2c_board_late_init() routine in
2772 boards/xxx/board.c is run AFTER the operations in i2c_init()
2773 is completed. This callpoint can be used to unreset i2c bus
2774 using CPU i2c controller register accesses for CPUs whose i2c
2775 controller provide such a method. It is called at the end of
2776 i2c_init() to allow i2c_init operations to setup the i2c bus
2777 controller on the CPU (e.g. setting bus speed & slave address).
2779 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2781 This option enables configuration of bi_iic_fast[] flags
2782 in u-boot bd_info structure based on u-boot environment
2783 variable "i2cfast". (see also i2cfast)
2785 CONFIG_I2C_MULTI_BUS
2787 This option allows the use of multiple I2C buses, each of which
2788 must have a controller. At any point in time, only one bus is
2789 active. To switch to a different bus, use the 'i2c dev' command.
2790 Note that bus numbering is zero-based.
2792 CONFIG_SYS_I2C_NOPROBES
2794 This option specifies a list of I2C devices that will be skipped
2795 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2796 is set, specify a list of bus-device pairs. Otherwise, specify
2797 a 1D array of device addresses
2800 #undef CONFIG_I2C_MULTI_BUS
2801 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2803 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2805 #define CONFIG_I2C_MULTI_BUS
2806 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2808 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2810 CONFIG_SYS_SPD_BUS_NUM
2812 If defined, then this indicates the I2C bus number for DDR SPD.
2813 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2815 CONFIG_SYS_RTC_BUS_NUM
2817 If defined, then this indicates the I2C bus number for the RTC.
2818 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2820 CONFIG_SYS_DTT_BUS_NUM
2822 If defined, then this indicates the I2C bus number for the DTT.
2823 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2825 CONFIG_SYS_I2C_DTT_ADDR:
2827 If defined, specifies the I2C address of the DTT device.
2828 If not defined, then U-Boot uses predefined value for
2829 specified DTT device.
2831 CONFIG_SOFT_I2C_READ_REPEATED_START
2833 defining this will force the i2c_read() function in
2834 the soft_i2c driver to perform an I2C repeated start
2835 between writing the address pointer and reading the
2836 data. If this define is omitted the default behaviour
2837 of doing a stop-start sequence will be used. Most I2C
2838 devices can use either method, but some require one or
2841 - SPI Support: CONFIG_SPI
2843 Enables SPI driver (so far only tested with
2844 SPI EEPROM, also an instance works with Crystal A/D and
2845 D/As on the SACSng board)
2849 Enables the driver for SPI controller on SuperH. Currently
2850 only SH7757 is supported.
2854 Enables extended (16-bit) SPI EEPROM addressing.
2855 (symmetrical to CONFIG_I2C_X)
2859 Enables a software (bit-bang) SPI driver rather than
2860 using hardware support. This is a general purpose
2861 driver that only requires three general I/O port pins
2862 (two outputs, one input) to function. If this is
2863 defined, the board configuration must define several
2864 SPI configuration items (port pins to use, etc). For
2865 an example, see include/configs/sacsng.h.
2869 Enables a hardware SPI driver for general-purpose reads
2870 and writes. As with CONFIG_SOFT_SPI, the board configuration
2871 must define a list of chip-select function pointers.
2872 Currently supported on some MPC8xxx processors. For an
2873 example, see include/configs/mpc8349emds.h.
2877 Enables the driver for the SPI controllers on i.MX and MXC
2878 SoCs. Currently i.MX31/35/51 are supported.
2880 CONFIG_SYS_SPI_MXC_WAIT
2881 Timeout for waiting until spi transfer completed.
2882 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2884 - FPGA Support: CONFIG_FPGA
2886 Enables FPGA subsystem.
2888 CONFIG_FPGA_<vendor>
2890 Enables support for specific chip vendors.
2893 CONFIG_FPGA_<family>
2895 Enables support for FPGA family.
2896 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2900 Specify the number of FPGA devices to support.
2902 CONFIG_CMD_FPGA_LOADMK
2904 Enable support for fpga loadmk command
2906 CONFIG_CMD_FPGA_LOADP
2908 Enable support for fpga loadp command - load partial bitstream
2910 CONFIG_CMD_FPGA_LOADBP
2912 Enable support for fpga loadbp command - load partial bitstream
2915 CONFIG_SYS_FPGA_PROG_FEEDBACK
2917 Enable printing of hash marks during FPGA configuration.
2919 CONFIG_SYS_FPGA_CHECK_BUSY
2921 Enable checks on FPGA configuration interface busy
2922 status by the configuration function. This option
2923 will require a board or device specific function to
2928 If defined, a function that provides delays in the FPGA
2929 configuration driver.
2931 CONFIG_SYS_FPGA_CHECK_CTRLC
2932 Allow Control-C to interrupt FPGA configuration
2934 CONFIG_SYS_FPGA_CHECK_ERROR
2936 Check for configuration errors during FPGA bitfile
2937 loading. For example, abort during Virtex II
2938 configuration if the INIT_B line goes low (which
2939 indicated a CRC error).
2941 CONFIG_SYS_FPGA_WAIT_INIT
2943 Maximum time to wait for the INIT_B line to de-assert
2944 after PROB_B has been de-asserted during a Virtex II
2945 FPGA configuration sequence. The default time is 500
2948 CONFIG_SYS_FPGA_WAIT_BUSY
2950 Maximum time to wait for BUSY to de-assert during
2951 Virtex II FPGA configuration. The default is 5 ms.
2953 CONFIG_SYS_FPGA_WAIT_CONFIG
2955 Time to wait after FPGA configuration. The default is
2958 - Configuration Management:
2961 Some SoCs need special image types (e.g. U-Boot binary
2962 with a special header) as build targets. By defining
2963 CONFIG_BUILD_TARGET in the SoC / board header, this
2964 special image will be automatically built upon calling
2969 If defined, this string will be added to the U-Boot
2970 version information (U_BOOT_VERSION)
2972 - Vendor Parameter Protection:
2974 U-Boot considers the values of the environment
2975 variables "serial#" (Board Serial Number) and
2976 "ethaddr" (Ethernet Address) to be parameters that
2977 are set once by the board vendor / manufacturer, and
2978 protects these variables from casual modification by
2979 the user. Once set, these variables are read-only,
2980 and write or delete attempts are rejected. You can
2981 change this behaviour:
2983 If CONFIG_ENV_OVERWRITE is #defined in your config
2984 file, the write protection for vendor parameters is
2985 completely disabled. Anybody can change or delete
2988 Alternatively, if you define _both_ an ethaddr in the
2989 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2990 Ethernet address is installed in the environment,
2991 which can be changed exactly ONCE by the user. [The
2992 serial# is unaffected by this, i. e. it remains
2995 The same can be accomplished in a more flexible way
2996 for any variable by configuring the type of access
2997 to allow for those variables in the ".flags" variable
2998 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3003 Define this variable to enable the reservation of
3004 "protected RAM", i. e. RAM which is not overwritten
3005 by U-Boot. Define CONFIG_PRAM to hold the number of
3006 kB you want to reserve for pRAM. You can overwrite
3007 this default value by defining an environment
3008 variable "pram" to the number of kB you want to
3009 reserve. Note that the board info structure will
3010 still show the full amount of RAM. If pRAM is
3011 reserved, a new environment variable "mem" will
3012 automatically be defined to hold the amount of
3013 remaining RAM in a form that can be passed as boot
3014 argument to Linux, for instance like that:
3016 setenv bootargs ... mem=\${mem}
3019 This way you can tell Linux not to use this memory,
3020 either, which results in a memory region that will
3021 not be affected by reboots.
3023 *WARNING* If your board configuration uses automatic
3024 detection of the RAM size, you must make sure that
3025 this memory test is non-destructive. So far, the
3026 following board configurations are known to be
3029 IVMS8, IVML24, SPD8xx, TQM8xxL,
3030 HERMES, IP860, RPXlite, LWMON,
3033 - Access to physical memory region (> 4GB)
3034 Some basic support is provided for operations on memory not
3035 normally accessible to U-Boot - e.g. some architectures
3036 support access to more than 4GB of memory on 32-bit
3037 machines using physical address extension or similar.
3038 Define CONFIG_PHYSMEM to access this basic support, which
3039 currently only supports clearing the memory.
3044 Define this variable to stop the system in case of a
3045 fatal error, so that you have to reset it manually.
3046 This is probably NOT a good idea for an embedded
3047 system where you want the system to reboot
3048 automatically as fast as possible, but it may be
3049 useful during development since you can try to debug
3050 the conditions that lead to the situation.
3052 CONFIG_NET_RETRY_COUNT
3054 This variable defines the number of retries for
3055 network operations like ARP, RARP, TFTP, or BOOTP
3056 before giving up the operation. If not defined, a
3057 default value of 5 is used.
3061 Timeout waiting for an ARP reply in milliseconds.
3065 Timeout in milliseconds used in NFS protocol.
3066 If you encounter "ERROR: Cannot umount" in nfs command,
3067 try longer timeout such as
3068 #define CONFIG_NFS_TIMEOUT 10000UL
3070 - Command Interpreter:
3071 CONFIG_AUTO_COMPLETE
3073 Enable auto completion of commands using TAB.
3075 CONFIG_SYS_PROMPT_HUSH_PS2
3077 This defines the secondary prompt string, which is
3078 printed when the command interpreter needs more input
3079 to complete a command. Usually "> ".
3083 In the current implementation, the local variables
3084 space and global environment variables space are
3085 separated. Local variables are those you define by
3086 simply typing `name=value'. To access a local
3087 variable later on, you have write `$name' or
3088 `${name}'; to execute the contents of a variable
3089 directly type `$name' at the command prompt.
3091 Global environment variables are those you use
3092 setenv/printenv to work with. To run a command stored
3093 in such a variable, you need to use the run command,
3094 and you must not use the '$' sign to access them.
3096 To store commands and special characters in a
3097 variable, please use double quotation marks
3098 surrounding the whole text of the variable, instead
3099 of the backslashes before semicolons and special
3102 - Command Line Editing and History:
3103 CONFIG_CMDLINE_EDITING
3105 Enable editing and History functions for interactive
3106 command line input operations
3108 - Default Environment:
3109 CONFIG_EXTRA_ENV_SETTINGS
3111 Define this to contain any number of null terminated
3112 strings (variable = value pairs) that will be part of
3113 the default environment compiled into the boot image.
3115 For example, place something like this in your
3116 board's config file:
3118 #define CONFIG_EXTRA_ENV_SETTINGS \
3122 Warning: This method is based on knowledge about the
3123 internal format how the environment is stored by the
3124 U-Boot code. This is NOT an official, exported
3125 interface! Although it is unlikely that this format
3126 will change soon, there is no guarantee either.
3127 You better know what you are doing here.
3129 Note: overly (ab)use of the default environment is
3130 discouraged. Make sure to check other ways to preset
3131 the environment like the "source" command or the
3134 CONFIG_ENV_VARS_UBOOT_CONFIG
3136 Define this in order to add variables describing the
3137 U-Boot build configuration to the default environment.
3138 These will be named arch, cpu, board, vendor, and soc.
3140 Enabling this option will cause the following to be defined:
3148 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3150 Define this in order to add variables describing certain
3151 run-time determined information about the hardware to the
3152 environment. These will be named board_name, board_rev.
3154 CONFIG_DELAY_ENVIRONMENT
3156 Normally the environment is loaded when the board is
3157 initialised so that it is available to U-Boot. This inhibits
3158 that so that the environment is not available until
3159 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3160 this is instead controlled by the value of
3161 /config/load-environment.
3163 - Parallel Flash support:
3166 Traditionally U-boot was run on systems with parallel NOR
3167 flash. This option is used to disable support for parallel NOR
3168 flash. This option should be defined if the board does not have
3171 If this option is not defined one of the generic flash drivers
3172 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3173 selected or the board must provide an implementation of the
3174 flash API (see include/flash.h).
3176 - DataFlash Support:
3177 CONFIG_HAS_DATAFLASH
3179 Defining this option enables DataFlash features and
3180 allows to read/write in Dataflash via the standard
3183 - Serial Flash support
3186 Defining this option enables SPI flash commands
3187 'sf probe/read/write/erase/update'.
3189 Usage requires an initial 'probe' to define the serial
3190 flash parameters, followed by read/write/erase/update
3193 The following defaults may be provided by the platform
3194 to handle the common case when only a single serial
3195 flash is present on the system.
3197 CONFIG_SF_DEFAULT_BUS Bus identifier
3198 CONFIG_SF_DEFAULT_CS Chip-select
3199 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3200 CONFIG_SF_DEFAULT_SPEED in Hz
3204 Define this option to include a destructive SPI flash
3207 CONFIG_SF_DUAL_FLASH Dual flash memories
3209 Define this option to use dual flash support where two flash
3210 memories can be connected with a given cs line.
3211 Currently Xilinx Zynq qspi supports these type of connections.
3213 - SystemACE Support:
3216 Adding this option adds support for Xilinx SystemACE
3217 chips attached via some sort of local bus. The address
3218 of the chip must also be defined in the
3219 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3221 #define CONFIG_SYSTEMACE
3222 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3224 When SystemACE support is added, the "ace" device type
3225 becomes available to the fat commands, i.e. fatls.
3227 - TFTP Fixed UDP Port:
3230 If this is defined, the environment variable tftpsrcp
3231 is used to supply the TFTP UDP source port value.
3232 If tftpsrcp isn't defined, the normal pseudo-random port
3233 number generator is used.
3235 Also, the environment variable tftpdstp is used to supply
3236 the TFTP UDP destination port value. If tftpdstp isn't
3237 defined, the normal port 69 is used.
3239 The purpose for tftpsrcp is to allow a TFTP server to
3240 blindly start the TFTP transfer using the pre-configured
3241 target IP address and UDP port. This has the effect of
3242 "punching through" the (Windows XP) firewall, allowing
3243 the remainder of the TFTP transfer to proceed normally.
3244 A better solution is to properly configure the firewall,
3245 but sometimes that is not allowed.
3250 This enables a generic 'hash' command which can produce
3251 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3255 Enable the hash verify command (hash -v). This adds to code
3258 CONFIG_SHA1 - This option enables support of hashing using SHA1
3259 algorithm. The hash is calculated in software.
3260 CONFIG_SHA256 - This option enables support of hashing using
3261 SHA256 algorithm. The hash is calculated in software.
3262 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3263 for SHA1/SHA256 hashing.
3264 This affects the 'hash' command and also the
3265 hash_lookup_algo() function.
3266 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3267 hardware-acceleration for SHA1/SHA256 progressive hashing.
3268 Data can be streamed in a block at a time and the hashing
3269 is performed in hardware.
3271 Note: There is also a sha1sum command, which should perhaps
3272 be deprecated in favour of 'hash sha1'.
3274 - Freescale i.MX specific commands:
3275 CONFIG_CMD_HDMIDETECT
3276 This enables 'hdmidet' command which returns true if an
3277 HDMI monitor is detected. This command is i.MX 6 specific.
3280 This enables the 'bmode' (bootmode) command for forcing
3281 a boot from specific media.
3283 This is useful for forcing the ROM's usb downloader to
3284 activate upon a watchdog reset which is nice when iterating
3285 on U-Boot. Using the reset button or running bmode normal
3286 will set it back to normal. This command currently
3287 supports i.MX53 and i.MX6.
3292 This enables the RSA algorithm used for FIT image verification
3293 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3295 The Modular Exponentiation algorithm in RSA is implemented using
3296 driver model. So CONFIG_DM needs to be enabled by default for this
3297 library to function.
3299 The signing part is build into mkimage regardless of this
3300 option. The software based modular exponentiation is built into
3301 mkimage irrespective of this option.
3303 - bootcount support:
3304 CONFIG_BOOTCOUNT_LIMIT
3306 This enables the bootcounter support, see:
3307 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3310 enable special bootcounter support on at91sam9xe based boards.
3312 enable special bootcounter support on blackfin based boards.
3314 enable special bootcounter support on da850 based boards.
3315 CONFIG_BOOTCOUNT_RAM
3316 enable support for the bootcounter in RAM
3317 CONFIG_BOOTCOUNT_I2C
3318 enable support for the bootcounter on an i2c (like RTC) device.
3319 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3320 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3322 CONFIG_BOOTCOUNT_ALEN = address len
3324 - Show boot progress:
3325 CONFIG_SHOW_BOOT_PROGRESS
3327 Defining this option allows to add some board-
3328 specific code (calling a user-provided function
3329 "show_boot_progress(int)") that enables you to show
3330 the system's boot progress on some display (for
3331 example, some LED's) on your board. At the moment,
3332 the following checkpoints are implemented:
3335 Legacy uImage format:
3338 1 common/cmd_bootm.c before attempting to boot an image
3339 -1 common/cmd_bootm.c Image header has bad magic number
3340 2 common/cmd_bootm.c Image header has correct magic number
3341 -2 common/cmd_bootm.c Image header has bad checksum
3342 3 common/cmd_bootm.c Image header has correct checksum
3343 -3 common/cmd_bootm.c Image data has bad checksum
3344 4 common/cmd_bootm.c Image data has correct checksum
3345 -4 common/cmd_bootm.c Image is for unsupported architecture
3346 5 common/cmd_bootm.c Architecture check OK
3347 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3348 6 common/cmd_bootm.c Image Type check OK
3349 -6 common/cmd_bootm.c gunzip uncompression error
3350 -7 common/cmd_bootm.c Unimplemented compression type
3351 7 common/cmd_bootm.c Uncompression OK
3352 8 common/cmd_bootm.c No uncompress/copy overwrite error
3353 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3355 9 common/image.c Start initial ramdisk verification
3356 -10 common/image.c Ramdisk header has bad magic number
3357 -11 common/image.c Ramdisk header has bad checksum
3358 10 common/image.c Ramdisk header is OK
3359 -12 common/image.c Ramdisk data has bad checksum
3360 11 common/image.c Ramdisk data has correct checksum
3361 12 common/image.c Ramdisk verification complete, start loading
3362 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3363 13 common/image.c Start multifile image verification
3364 14 common/image.c No initial ramdisk, no multifile, continue.
3366 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3368 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3369 -31 post/post.c POST test failed, detected by post_output_backlog()
3370 -32 post/post.c POST test failed, detected by post_run_single()
3372 34 common/cmd_doc.c before loading a Image from a DOC device
3373 -35 common/cmd_doc.c Bad usage of "doc" command
3374 35 common/cmd_doc.c correct usage of "doc" command
3375 -36 common/cmd_doc.c No boot device
3376 36 common/cmd_doc.c correct boot device
3377 -37 common/cmd_doc.c Unknown Chip ID on boot device
3378 37 common/cmd_doc.c correct chip ID found, device available
3379 -38 common/cmd_doc.c Read Error on boot device
3380 38 common/cmd_doc.c reading Image header from DOC device OK
3381 -39 common/cmd_doc.c Image header has bad magic number
3382 39 common/cmd_doc.c Image header has correct magic number
3383 -40 common/cmd_doc.c Error reading Image from DOC device
3384 40 common/cmd_doc.c Image header has correct magic number
3385 41 common/cmd_ide.c before loading a Image from a IDE device
3386 -42 common/cmd_ide.c Bad usage of "ide" command
3387 42 common/cmd_ide.c correct usage of "ide" command
3388 -43 common/cmd_ide.c No boot device
3389 43 common/cmd_ide.c boot device found
3390 -44 common/cmd_ide.c Device not available
3391 44 common/cmd_ide.c Device available
3392 -45 common/cmd_ide.c wrong partition selected
3393 45 common/cmd_ide.c partition selected
3394 -46 common/cmd_ide.c Unknown partition table
3395 46 common/cmd_ide.c valid partition table found
3396 -47 common/cmd_ide.c Invalid partition type
3397 47 common/cmd_ide.c correct partition type
3398 -48 common/cmd_ide.c Error reading Image Header on boot device
3399 48 common/cmd_ide.c reading Image Header from IDE device OK
3400 -49 common/cmd_ide.c Image header has bad magic number
3401 49 common/cmd_ide.c Image header has correct magic number
3402 -50 common/cmd_ide.c Image header has bad checksum
3403 50 common/cmd_ide.c Image header has correct checksum
3404 -51 common/cmd_ide.c Error reading Image from IDE device
3405 51 common/cmd_ide.c reading Image from IDE device OK
3406 52 common/cmd_nand.c before loading a Image from a NAND device
3407 -53 common/cmd_nand.c Bad usage of "nand" command
3408 53 common/cmd_nand.c correct usage of "nand" command
3409 -54 common/cmd_nand.c No boot device
3410 54 common/cmd_nand.c boot device found
3411 -55 common/cmd_nand.c Unknown Chip ID on boot device
3412 55 common/cmd_nand.c correct chip ID found, device available
3413 -56 common/cmd_nand.c Error reading Image Header on boot device
3414 56 common/cmd_nand.c reading Image Header from NAND device OK
3415 -57 common/cmd_nand.c Image header has bad magic number
3416 57 common/cmd_nand.c Image header has correct magic number
3417 -58 common/cmd_nand.c Error reading Image from NAND device
3418 58 common/cmd_nand.c reading Image from NAND device OK
3420 -60 common/env_common.c Environment has a bad CRC, using default
3422 64 net/eth.c starting with Ethernet configuration.
3423 -64 net/eth.c no Ethernet found.
3424 65 net/eth.c Ethernet found.
3426 -80 common/cmd_net.c usage wrong
3427 80 common/cmd_net.c before calling net_loop()
3428 -81 common/cmd_net.c some error in net_loop() occurred
3429 81 common/cmd_net.c net_loop() back without error
3430 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3431 82 common/cmd_net.c trying automatic boot
3432 83 common/cmd_net.c running "source" command
3433 -83 common/cmd_net.c some error in automatic boot or "source" command
3434 84 common/cmd_net.c end without errors
3439 100 common/cmd_bootm.c Kernel FIT Image has correct format
3440 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3441 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3442 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3443 102 common/cmd_bootm.c Kernel unit name specified
3444 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3445 103 common/cmd_bootm.c Found configuration node
3446 104 common/cmd_bootm.c Got kernel subimage node offset
3447 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3448 105 common/cmd_bootm.c Kernel subimage hash verification OK
3449 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3450 106 common/cmd_bootm.c Architecture check OK
3451 -106 common/cmd_bootm.c Kernel subimage has wrong type
3452 107 common/cmd_bootm.c Kernel subimage type OK
3453 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3454 108 common/cmd_bootm.c Got kernel subimage data/size
3455 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3456 -109 common/cmd_bootm.c Can't get kernel subimage type
3457 -110 common/cmd_bootm.c Can't get kernel subimage comp
3458 -111 common/cmd_bootm.c Can't get kernel subimage os
3459 -112 common/cmd_bootm.c Can't get kernel subimage load address
3460 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3462 120 common/image.c Start initial ramdisk verification
3463 -120 common/image.c Ramdisk FIT image has incorrect format
3464 121 common/image.c Ramdisk FIT image has correct format
3465 122 common/image.c No ramdisk subimage unit name, using configuration
3466 -122 common/image.c Can't get configuration for ramdisk subimage
3467 123 common/image.c Ramdisk unit name specified
3468 -124 common/image.c Can't get ramdisk subimage node offset
3469 125 common/image.c Got ramdisk subimage node offset
3470 -125 common/image.c Ramdisk subimage hash verification failed
3471 126 common/image.c Ramdisk subimage hash verification OK
3472 -126 common/image.c Ramdisk subimage for unsupported architecture
3473 127 common/image.c Architecture check OK
3474 -127 common/image.c Can't get ramdisk subimage data/size
3475 128 common/image.c Got ramdisk subimage data/size
3476 129 common/image.c Can't get ramdisk load address
3477 -129 common/image.c Got ramdisk load address
3479 -130 common/cmd_doc.c Incorrect FIT image format
3480 131 common/cmd_doc.c FIT image format OK
3482 -140 common/cmd_ide.c Incorrect FIT image format
3483 141 common/cmd_ide.c FIT image format OK
3485 -150 common/cmd_nand.c Incorrect FIT image format
3486 151 common/cmd_nand.c FIT image format OK
3488 - legacy image format:
3489 CONFIG_IMAGE_FORMAT_LEGACY
3490 enables the legacy image format support in U-Boot.
3493 enabled if CONFIG_FIT_SIGNATURE is not defined.
3495 CONFIG_DISABLE_IMAGE_LEGACY
3496 disable the legacy image format
3498 This define is introduced, as the legacy image format is
3499 enabled per default for backward compatibility.
3501 - FIT image support:
3503 Enable support for the FIT uImage format.
3505 CONFIG_FIT_BEST_MATCH
3506 When no configuration is explicitly selected, default to the
3507 one whose fdt's compatibility field best matches that of
3508 U-Boot itself. A match is considered "best" if it matches the
3509 most specific compatibility entry of U-Boot's fdt's root node.
3510 The order of entries in the configuration's fdt is ignored.
3512 CONFIG_FIT_SIGNATURE
3513 This option enables signature verification of FIT uImages,
3514 using a hash signed and verified using RSA. If
3515 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3516 hashing is available using hardware, RSA library will use it.
3517 See doc/uImage.FIT/signature.txt for more details.
3519 WARNING: When relying on signed FIT images with required
3520 signature check the legacy image format is default
3521 disabled. If a board need legacy image format support
3522 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3524 CONFIG_FIT_DISABLE_SHA256
3525 Supporting SHA256 hashes has quite an impact on binary size.
3526 For constrained systems sha256 hash support can be disabled
3529 - Standalone program support:
3530 CONFIG_STANDALONE_LOAD_ADDR
3532 This option defines a board specific value for the
3533 address where standalone program gets loaded, thus
3534 overwriting the architecture dependent default
3537 - Frame Buffer Address:
3540 Define CONFIG_FB_ADDR if you want to use specific
3541 address for frame buffer. This is typically the case
3542 when using a graphics controller has separate video
3543 memory. U-Boot will then place the frame buffer at
3544 the given address instead of dynamically reserving it
3545 in system RAM by calling lcd_setmem(), which grabs
3546 the memory for the frame buffer depending on the
3547 configured panel size.
3549 Please see board_init_f function.
3551 - Automatic software updates via TFTP server
3553 CONFIG_UPDATE_TFTP_CNT_MAX
3554 CONFIG_UPDATE_TFTP_MSEC_MAX
3556 These options enable and control the auto-update feature;
3557 for a more detailed description refer to doc/README.update.
3559 - MTD Support (mtdparts command, UBI support)
3562 Adds the MTD device infrastructure from the Linux kernel.
3563 Needed for mtdparts command support.
3565 CONFIG_MTD_PARTITIONS
3567 Adds the MTD partitioning infrastructure from the Linux
3568 kernel. Needed for UBI support.
3573 Adds commands for interacting with MTD partitions formatted
3574 with the UBI flash translation layer
3576 Requires also defining CONFIG_RBTREE
3578 CONFIG_UBI_SILENCE_MSG
3580 Make the verbose messages from UBI stop printing. This leaves
3581 warnings and errors enabled.
3584 CONFIG_MTD_UBI_WL_THRESHOLD
3585 This parameter defines the maximum difference between the highest
3586 erase counter value and the lowest erase counter value of eraseblocks
3587 of UBI devices. When this threshold is exceeded, UBI starts performing
3588 wear leveling by means of moving data from eraseblock with low erase
3589 counter to eraseblocks with high erase counter.
3591 The default value should be OK for SLC NAND flashes, NOR flashes and
3592 other flashes which have eraseblock life-cycle 100000 or more.
3593 However, in case of MLC NAND flashes which typically have eraseblock
3594 life-cycle less than 10000, the threshold should be lessened (e.g.,
3595 to 128 or 256, although it does not have to be power of 2).
3599 CONFIG_MTD_UBI_BEB_LIMIT
3600 This option specifies the maximum bad physical eraseblocks UBI
3601 expects on the MTD device (per 1024 eraseblocks). If the
3602 underlying flash does not admit of bad eraseblocks (e.g. NOR
3603 flash), this value is ignored.
3605 NAND datasheets often specify the minimum and maximum NVM
3606 (Number of Valid Blocks) for the flashes' endurance lifetime.
3607 The maximum expected bad eraseblocks per 1024 eraseblocks
3608 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3609 which gives 20 for most NANDs (MaxNVB is basically the total
3610 count of eraseblocks on the chip).
3612 To put it differently, if this value is 20, UBI will try to
3613 reserve about 1.9% of physical eraseblocks for bad blocks
3614 handling. And that will be 1.9% of eraseblocks on the entire
3615 NAND chip, not just the MTD partition UBI attaches. This means
3616 that if you have, say, a NAND flash chip admits maximum 40 bad
3617 eraseblocks, and it is split on two MTD partitions of the same
3618 size, UBI will reserve 40 eraseblocks when attaching a
3623 CONFIG_MTD_UBI_FASTMAP
3624 Fastmap is a mechanism which allows attaching an UBI device
3625 in nearly constant time. Instead of scanning the whole MTD device it
3626 only has to locate a checkpoint (called fastmap) on the device.
3627 The on-flash fastmap contains all information needed to attach
3628 the device. Using fastmap makes only sense on large devices where
3629 attaching by scanning takes long. UBI will not automatically install
3630 a fastmap on old images, but you can set the UBI parameter
3631 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3632 that fastmap-enabled images are still usable with UBI implementations
3633 without fastmap support. On typical flash devices the whole fastmap
3634 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3636 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3637 Set this parameter to enable fastmap automatically on images
3644 Adds commands for interacting with UBI volumes formatted as
3645 UBIFS. UBIFS is read-only in u-boot.
3647 Requires UBI support as well as CONFIG_LZO
3649 CONFIG_UBIFS_SILENCE_MSG
3651 Make the verbose messages from UBIFS stop printing. This leaves
3652 warnings and errors enabled.
3656 Enable building of SPL globally.
3659 LDSCRIPT for linking the SPL binary.
3661 CONFIG_SPL_MAX_FOOTPRINT
3662 Maximum size in memory allocated to the SPL, BSS included.
3663 When defined, the linker checks that the actual memory
3664 used by SPL from _start to __bss_end does not exceed it.
3665 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3666 must not be both defined at the same time.
3669 Maximum size of the SPL image (text, data, rodata, and
3670 linker lists sections), BSS excluded.
3671 When defined, the linker checks that the actual size does
3674 CONFIG_SPL_TEXT_BASE
3675 TEXT_BASE for linking the SPL binary.
3677 CONFIG_SPL_RELOC_TEXT_BASE
3678 Address to relocate to. If unspecified, this is equal to
3679 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3681 CONFIG_SPL_BSS_START_ADDR
3682 Link address for the BSS within the SPL binary.
3684 CONFIG_SPL_BSS_MAX_SIZE
3685 Maximum size in memory allocated to the SPL BSS.
3686 When defined, the linker checks that the actual memory used
3687 by SPL from __bss_start to __bss_end does not exceed it.
3688 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3689 must not be both defined at the same time.
3692 Adress of the start of the stack SPL will use
3694 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3695 When defined, SPL will panic() if the image it has
3696 loaded does not have a signature.
3697 Defining this is useful when code which loads images
3698 in SPL cannot guarantee that absolutely all read errors
3700 An example is the LPC32XX MLC NAND driver, which will
3701 consider that a completely unreadable NAND block is bad,
3702 and thus should be skipped silently.
3704 CONFIG_SPL_RELOC_STACK
3705 Adress of the start of the stack SPL will use after
3706 relocation. If unspecified, this is equal to
3709 CONFIG_SYS_SPL_MALLOC_START
3710 Starting address of the malloc pool used in SPL.
3712 CONFIG_SYS_SPL_MALLOC_SIZE
3713 The size of the malloc pool used in SPL.
3715 CONFIG_SPL_FRAMEWORK
3716 Enable the SPL framework under common/. This framework
3717 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3718 NAND loading of the Linux Kernel.
3721 Enable booting directly to an OS from SPL.
3722 See also: doc/README.falcon
3724 CONFIG_SPL_DISPLAY_PRINT
3725 For ARM, enable an optional function to print more information
3726 about the running system.
3728 CONFIG_SPL_INIT_MINIMAL
3729 Arch init code should be built for a very small image
3731 CONFIG_SPL_LIBCOMMON_SUPPORT
3732 Support for common/libcommon.o in SPL binary
3734 CONFIG_SPL_LIBDISK_SUPPORT
3735 Support for disk/libdisk.o in SPL binary
3737 CONFIG_SPL_I2C_SUPPORT
3738 Support for drivers/i2c/libi2c.o in SPL binary
3740 CONFIG_SPL_GPIO_SUPPORT
3741 Support for drivers/gpio/libgpio.o in SPL binary
3743 CONFIG_SPL_MMC_SUPPORT
3744 Support for drivers/mmc/libmmc.o in SPL binary
3746 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3747 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3748 Address and partition on the MMC to load U-Boot from
3749 when the MMC is being used in raw mode.
3751 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3752 Partition on the MMC to load U-Boot from when the MMC is being
3755 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3756 Sector to load kernel uImage from when MMC is being
3757 used in raw mode (for Falcon mode)
3759 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3760 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3761 Sector and number of sectors to load kernel argument
3762 parameters from when MMC is being used in raw mode
3765 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3766 Partition on the MMC to load U-Boot from when the MMC is being
3769 CONFIG_SPL_FAT_SUPPORT
3770 Support for fs/fat/libfat.o in SPL binary
3772 CONFIG_SPL_EXT_SUPPORT
3773 Support for EXT filesystem in SPL binary
3775 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3776 Filename to read to load U-Boot when reading from filesystem
3778 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3779 Filename to read to load kernel uImage when reading
3780 from filesystem (for Falcon mode)
3782 CONFIG_SPL_FS_LOAD_ARGS_NAME
3783 Filename to read to load kernel argument parameters
3784 when reading from filesystem (for Falcon mode)
3786 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3787 Set this for NAND SPL on PPC mpc83xx targets, so that
3788 start.S waits for the rest of the SPL to load before
3789 continuing (the hardware starts execution after just
3790 loading the first page rather than the full 4K).
3792 CONFIG_SPL_SKIP_RELOCATE
3793 Avoid SPL relocation
3795 CONFIG_SPL_NAND_BASE
3796 Include nand_base.c in the SPL. Requires
3797 CONFIG_SPL_NAND_DRIVERS.
3799 CONFIG_SPL_NAND_DRIVERS
3800 SPL uses normal NAND drivers, not minimal drivers.
3803 Include standard software ECC in the SPL
3805 CONFIG_SPL_NAND_SIMPLE
3806 Support for NAND boot using simple NAND drivers that
3807 expose the cmd_ctrl() interface.
3809 CONFIG_SPL_MTD_SUPPORT
3810 Support for the MTD subsystem within SPL. Useful for
3811 environment on NAND support within SPL.
3813 CONFIG_SPL_NAND_RAW_ONLY
3814 Support to boot only raw u-boot.bin images. Use this only
3815 if you need to save space.
3817 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3818 Set for the SPL on PPC mpc8xxx targets, support for
3819 drivers/ddr/fsl/libddr.o in SPL binary.
3821 CONFIG_SPL_COMMON_INIT_DDR
3822 Set for common ddr init with serial presence detect in
3825 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3826 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3827 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3828 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3829 CONFIG_SYS_NAND_ECCBYTES
3830 Defines the size and behavior of the NAND that SPL uses
3833 CONFIG_SPL_NAND_BOOT
3834 Add support NAND boot
3836 CONFIG_SYS_NAND_U_BOOT_OFFS
3837 Location in NAND to read U-Boot from
3839 CONFIG_SYS_NAND_U_BOOT_DST
3840 Location in memory to load U-Boot to
3842 CONFIG_SYS_NAND_U_BOOT_SIZE
3843 Size of image to load
3845 CONFIG_SYS_NAND_U_BOOT_START
3846 Entry point in loaded image to jump to
3848 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3849 Define this if you need to first read the OOB and then the
3850 data. This is used, for example, on davinci platforms.
3852 CONFIG_SPL_OMAP3_ID_NAND
3853 Support for an OMAP3-specific set of functions to return the
3854 ID and MFR of the first attached NAND chip, if present.
3856 CONFIG_SPL_SERIAL_SUPPORT
3857 Support for drivers/serial/libserial.o in SPL binary
3859 CONFIG_SPL_SPI_FLASH_SUPPORT
3860 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3862 CONFIG_SPL_SPI_SUPPORT
3863 Support for drivers/spi/libspi.o in SPL binary
3865 CONFIG_SPL_RAM_DEVICE
3866 Support for running image already present in ram, in SPL binary
3868 CONFIG_SPL_LIBGENERIC_SUPPORT
3869 Support for lib/libgeneric.o in SPL binary
3871 CONFIG_SPL_ENV_SUPPORT
3872 Support for the environment operating in SPL binary
3874 CONFIG_SPL_NET_SUPPORT
3875 Support for the net/libnet.o in SPL binary.
3876 It conflicts with SPL env from storage medium specified by
3877 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3880 Image offset to which the SPL should be padded before appending
3881 the SPL payload. By default, this is defined as
3882 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3883 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3884 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3887 Final target image containing SPL and payload. Some SPLs
3888 use an arch-specific makefile fragment instead, for
3889 example if more than one image needs to be produced.
3891 CONFIG_FIT_SPL_PRINT
3892 Printing information about a FIT image adds quite a bit of
3893 code to SPL. So this is normally disabled in SPL. Use this
3894 option to re-enable it. This will affect the output of the
3895 bootm command when booting a FIT image.
3899 Enable building of TPL globally.
3902 Image offset to which the TPL should be padded before appending
3903 the TPL payload. By default, this is defined as
3904 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3905 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3906 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3911 [so far only for SMDK2400 boards]
3913 - Modem support enable:
3914 CONFIG_MODEM_SUPPORT
3916 - RTS/CTS Flow control enable:
3919 - Modem debug support:
3920 CONFIG_MODEM_SUPPORT_DEBUG
3922 Enables debugging stuff (char screen[1024], dbg())
3923 for modem support. Useful only with BDI2000.
3925 - Interrupt support (PPC):
3927 There are common interrupt_init() and timer_interrupt()
3928 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3929 for CPU specific initialization. interrupt_init_cpu()
3930 should set decrementer_count to appropriate value. If
3931 CPU resets decrementer automatically after interrupt
3932 (ppc4xx) it should set decrementer_count to zero.
3933 timer_interrupt() calls timer_interrupt_cpu() for CPU
3934 specific handling. If board has watchdog / status_led
3935 / other_activity_monitor it works automatically from
3936 general timer_interrupt().
3940 In the target system modem support is enabled when a
3941 specific key (key combination) is pressed during
3942 power-on. Otherwise U-Boot will boot normally
3943 (autoboot). The key_pressed() function is called from
3944 board_init(). Currently key_pressed() is a dummy
3945 function, returning 1 and thus enabling modem
3948 If there are no modem init strings in the
3949 environment, U-Boot proceed to autoboot; the
3950 previous output (banner, info printfs) will be
3953 See also: doc/README.Modem
3955 Board initialization settings:
3956 ------------------------------
3958 During Initialization u-boot calls a number of board specific functions
3959 to allow the preparation of board specific prerequisites, e.g. pin setup
3960 before drivers are initialized. To enable these callbacks the
3961 following configuration macros have to be defined. Currently this is
3962 architecture specific, so please check arch/your_architecture/lib/board.c
3963 typically in board_init_f() and board_init_r().
3965 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3966 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3967 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3968 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3970 Configuration Settings:
3971 -----------------------
3973 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3974 Optionally it can be defined to support 64-bit memory commands.
3976 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3977 undefine this when you're short of memory.
3979 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3980 width of the commands listed in the 'help' command output.
3982 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3983 prompt for user input.
3985 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3987 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3989 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3991 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3992 the application (usually a Linux kernel) when it is
3995 - CONFIG_SYS_BAUDRATE_TABLE:
3996 List of legal baudrate settings for this board.
3998 - CONFIG_SYS_CONSOLE_INFO_QUIET
3999 Suppress display of console information at boot.
4001 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4002 If the board specific function
4003 extern int overwrite_console (void);
4004 returns 1, the stdin, stderr and stdout are switched to the
4005 serial port, else the settings in the environment are used.
4007 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4008 Enable the call to overwrite_console().
4010 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4011 Enable overwrite of previous console environment settings.
4013 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4014 Begin and End addresses of the area used by the
4017 - CONFIG_SYS_ALT_MEMTEST:
4018 Enable an alternate, more extensive memory test.
4020 - CONFIG_SYS_MEMTEST_SCRATCH:
4021 Scratch address used by the alternate memory test
4022 You only need to set this if address zero isn't writeable
4024 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4025 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4026 this specified memory area will get subtracted from the top
4027 (end) of RAM and won't get "touched" at all by U-Boot. By
4028 fixing up gd->ram_size the Linux kernel should gets passed
4029 the now "corrected" memory size and won't touch it either.
4030 This should work for arch/ppc and arch/powerpc. Only Linux
4031 board ports in arch/powerpc with bootwrapper support that
4032 recalculate the memory size from the SDRAM controller setup
4033 will have to get fixed in Linux additionally.
4035 This option can be used as a workaround for the 440EPx/GRx
4036 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4039 WARNING: Please make sure that this value is a multiple of
4040 the Linux page size (normally 4k). If this is not the case,
4041 then the end address of the Linux memory will be located at a
4042 non page size aligned address and this could cause major
4045 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4046 Enable temporary baudrate change while serial download
4048 - CONFIG_SYS_SDRAM_BASE:
4049 Physical start address of SDRAM. _Must_ be 0 here.
4051 - CONFIG_SYS_MBIO_BASE:
4052 Physical start address of Motherboard I/O (if using a
4055 - CONFIG_SYS_FLASH_BASE:
4056 Physical start address of Flash memory.
4058 - CONFIG_SYS_MONITOR_BASE:
4059 Physical start address of boot monitor code (set by
4060 make config files to be same as the text base address
4061 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4062 CONFIG_SYS_FLASH_BASE when booting from flash.
4064 - CONFIG_SYS_MONITOR_LEN:
4065 Size of memory reserved for monitor code, used to
4066 determine _at_compile_time_ (!) if the environment is
4067 embedded within the U-Boot image, or in a separate
4070 - CONFIG_SYS_MALLOC_LEN:
4071 Size of DRAM reserved for malloc() use.
4073 - CONFIG_SYS_MALLOC_F_LEN
4074 Size of the malloc() pool for use before relocation. If
4075 this is defined, then a very simple malloc() implementation
4076 will become available before relocation. The address is just
4077 below the global data, and the stack is moved down to make
4080 This feature allocates regions with increasing addresses
4081 within the region. calloc() is supported, but realloc()
4082 is not available. free() is supported but does nothing.
4083 The memory will be freed (or in fact just forgotten) when
4084 U-Boot relocates itself.
4086 Pre-relocation malloc() is only supported on ARM and sandbox
4087 at present but is fairly easy to enable for other archs.
4089 - CONFIG_SYS_MALLOC_SIMPLE
4090 Provides a simple and small malloc() and calloc() for those
4091 boards which do not use the full malloc in SPL (which is
4092 enabled with CONFIG_SYS_SPL_MALLOC_START).
4094 - CONFIG_SYS_NONCACHED_MEMORY:
4095 Size of non-cached memory area. This area of memory will be
4096 typically located right below the malloc() area and mapped
4097 uncached in the MMU. This is useful for drivers that would
4098 otherwise require a lot of explicit cache maintenance. For
4099 some drivers it's also impossible to properly maintain the
4100 cache. For example if the regions that need to be flushed
4101 are not a multiple of the cache-line size, *and* padding
4102 cannot be allocated between the regions to align them (i.e.
4103 if the HW requires a contiguous array of regions, and the
4104 size of each region is not cache-aligned), then a flush of
4105 one region may result in overwriting data that hardware has
4106 written to another region in the same cache-line. This can
4107 happen for example in network drivers where descriptors for
4108 buffers are typically smaller than the CPU cache-line (e.g.
4109 16 bytes vs. 32 or 64 bytes).
4111 Non-cached memory is only supported on 32-bit ARM at present.
4113 - CONFIG_SYS_BOOTM_LEN:
4114 Normally compressed uImages are limited to an
4115 uncompressed size of 8 MBytes. If this is not enough,
4116 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4117 to adjust this setting to your needs.
4119 - CONFIG_SYS_BOOTMAPSZ:
4120 Maximum size of memory mapped by the startup code of
4121 the Linux kernel; all data that must be processed by
4122 the Linux kernel (bd_info, boot arguments, FDT blob if
4123 used) must be put below this limit, unless "bootm_low"
4124 environment variable is defined and non-zero. In such case
4125 all data for the Linux kernel must be between "bootm_low"
4126 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4127 variable "bootm_mapsize" will override the value of
4128 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4129 then the value in "bootm_size" will be used instead.
4131 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4132 Enable initrd_high functionality. If defined then the
4133 initrd_high feature is enabled and the bootm ramdisk subcommand
4136 - CONFIG_SYS_BOOT_GET_CMDLINE:
4137 Enables allocating and saving kernel cmdline in space between
4138 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4140 - CONFIG_SYS_BOOT_GET_KBD:
4141 Enables allocating and saving a kernel copy of the bd_info in
4142 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4144 - CONFIG_SYS_MAX_FLASH_BANKS:
4145 Max number of Flash memory banks
4147 - CONFIG_SYS_MAX_FLASH_SECT:
4148 Max number of sectors on a Flash chip
4150 - CONFIG_SYS_FLASH_ERASE_TOUT:
4151 Timeout for Flash erase operations (in ms)
4153 - CONFIG_SYS_FLASH_WRITE_TOUT:
4154 Timeout for Flash write operations (in ms)
4156 - CONFIG_SYS_FLASH_LOCK_TOUT
4157 Timeout for Flash set sector lock bit operation (in ms)
4159 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4160 Timeout for Flash clear lock bits operation (in ms)
4162 - CONFIG_SYS_FLASH_PROTECTION
4163 If defined, hardware flash sectors protection is used
4164 instead of U-Boot software protection.
4166 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4168 Enable TFTP transfers directly to flash memory;
4169 without this option such a download has to be
4170 performed in two steps: (1) download to RAM, and (2)
4171 copy from RAM to flash.
4173 The two-step approach is usually more reliable, since
4174 you can check if the download worked before you erase
4175 the flash, but in some situations (when system RAM is
4176 too limited to allow for a temporary copy of the
4177 downloaded image) this option may be very useful.
4179 - CONFIG_SYS_FLASH_CFI:
4180 Define if the flash driver uses extra elements in the
4181 common flash structure for storing flash geometry.
4183 - CONFIG_FLASH_CFI_DRIVER
4184 This option also enables the building of the cfi_flash driver
4185 in the drivers directory
4187 - CONFIG_FLASH_CFI_MTD
4188 This option enables the building of the cfi_mtd driver
4189 in the drivers directory. The driver exports CFI flash
4192 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4193 Use buffered writes to flash.
4195 - CONFIG_FLASH_SPANSION_S29WS_N
4196 s29ws-n MirrorBit flash has non-standard addresses for buffered
4199 - CONFIG_SYS_FLASH_QUIET_TEST
4200 If this option is defined, the common CFI flash doesn't
4201 print it's warning upon not recognized FLASH banks. This
4202 is useful, if some of the configured banks are only
4203 optionally available.
4205 - CONFIG_FLASH_SHOW_PROGRESS
4206 If defined (must be an integer), print out countdown
4207 digits and dots. Recommended value: 45 (9..1) for 80
4208 column displays, 15 (3..1) for 40 column displays.
4210 - CONFIG_FLASH_VERIFY
4211 If defined, the content of the flash (destination) is compared
4212 against the source after the write operation. An error message
4213 will be printed when the contents are not identical.
4214 Please note that this option is useless in nearly all cases,
4215 since such flash programming errors usually are detected earlier
4216 while unprotecting/erasing/programming. Please only enable
4217 this option if you really know what you are doing.
4219 - CONFIG_SYS_RX_ETH_BUFFER:
4220 Defines the number of Ethernet receive buffers. On some
4221 Ethernet controllers it is recommended to set this value
4222 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4223 buffers can be full shortly after enabling the interface
4224 on high Ethernet traffic.
4225 Defaults to 4 if not defined.
4227 - CONFIG_ENV_MAX_ENTRIES
4229 Maximum number of entries in the hash table that is used
4230 internally to store the environment settings. The default
4231 setting is supposed to be generous and should work in most
4232 cases. This setting can be used to tune behaviour; see
4233 lib/hashtable.c for details.
4235 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4236 - CONFIG_ENV_FLAGS_LIST_STATIC
4237 Enable validation of the values given to environment variables when
4238 calling env set. Variables can be restricted to only decimal,
4239 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4240 the variables can also be restricted to IP address or MAC address.
4242 The format of the list is:
4243 type_attribute = [s|d|x|b|i|m]
4244 access_attribute = [a|r|o|c]
4245 attributes = type_attribute[access_attribute]
4246 entry = variable_name[:attributes]
4249 The type attributes are:
4250 s - String (default)
4253 b - Boolean ([1yYtT|0nNfF])
4257 The access attributes are:
4263 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4264 Define this to a list (string) to define the ".flags"
4265 environment variable in the default or embedded environment.
4267 - CONFIG_ENV_FLAGS_LIST_STATIC
4268 Define this to a list (string) to define validation that
4269 should be done if an entry is not found in the ".flags"
4270 environment variable. To override a setting in the static
4271 list, simply add an entry for the same variable name to the
4274 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4275 regular expression. This allows multiple variables to define the same
4276 flags without explicitly listing them for each variable.
4278 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4279 If defined, don't allow the -f switch to env set override variable
4282 - CONFIG_SYS_GENERIC_BOARD
4283 This selects the architecture-generic board system instead of the
4284 architecture-specific board files. It is intended to move boards
4285 to this new framework over time. Defining this will disable the
4286 arch/foo/lib/board.c file and use common/board_f.c and
4287 common/board_r.c instead. To use this option your architecture
4288 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4289 If you find problems enabling this option on your board please report
4290 the problem and send patches!
4292 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4293 This is set by OMAP boards for the max time that reset should
4294 be asserted. See doc/README.omap-reset-time for details on how
4295 the value can be calculated on a given board.
4298 If stdint.h is available with your toolchain you can define this
4299 option to enable it. You can provide option 'USE_STDINT=1' when
4300 building U-Boot to enable this.
4302 The following definitions that deal with the placement and management
4303 of environment data (variable area); in general, we support the
4304 following configurations:
4306 - CONFIG_BUILD_ENVCRC:
4308 Builds up envcrc with the target environment so that external utils
4309 may easily extract it and embed it in final U-Boot images.
4311 - CONFIG_ENV_IS_IN_FLASH:
4313 Define this if the environment is in flash memory.
4315 a) The environment occupies one whole flash sector, which is
4316 "embedded" in the text segment with the U-Boot code. This
4317 happens usually with "bottom boot sector" or "top boot
4318 sector" type flash chips, which have several smaller
4319 sectors at the start or the end. For instance, such a
4320 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4321 such a case you would place the environment in one of the
4322 4 kB sectors - with U-Boot code before and after it. With
4323 "top boot sector" type flash chips, you would put the
4324 environment in one of the last sectors, leaving a gap
4325 between U-Boot and the environment.
4327 - CONFIG_ENV_OFFSET:
4329 Offset of environment data (variable area) to the
4330 beginning of flash memory; for instance, with bottom boot
4331 type flash chips the second sector can be used: the offset
4332 for this sector is given here.
4334 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4338 This is just another way to specify the start address of
4339 the flash sector containing the environment (instead of
4342 - CONFIG_ENV_SECT_SIZE:
4344 Size of the sector containing the environment.
4347 b) Sometimes flash chips have few, equal sized, BIG sectors.
4348 In such a case you don't want to spend a whole sector for
4353 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4354 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4355 of this flash sector for the environment. This saves
4356 memory for the RAM copy of the environment.
4358 It may also save flash memory if you decide to use this
4359 when your environment is "embedded" within U-Boot code,
4360 since then the remainder of the flash sector could be used
4361 for U-Boot code. It should be pointed out that this is
4362 STRONGLY DISCOURAGED from a robustness point of view:
4363 updating the environment in flash makes it always
4364 necessary to erase the WHOLE sector. If something goes
4365 wrong before the contents has been restored from a copy in
4366 RAM, your target system will be dead.
4368 - CONFIG_ENV_ADDR_REDUND
4369 CONFIG_ENV_SIZE_REDUND
4371 These settings describe a second storage area used to hold
4372 a redundant copy of the environment data, so that there is
4373 a valid backup copy in case there is a power failure during
4374 a "saveenv" operation.
4376 BE CAREFUL! Any changes to the flash layout, and some changes to the
4377 source code will make it necessary to adapt <board>/u-boot.lds*
4381 - CONFIG_ENV_IS_IN_NVRAM:
4383 Define this if you have some non-volatile memory device
4384 (NVRAM, battery buffered SRAM) which you want to use for the
4390 These two #defines are used to determine the memory area you
4391 want to use for environment. It is assumed that this memory
4392 can just be read and written to, without any special
4395 BE CAREFUL! The first access to the environment happens quite early
4396 in U-Boot initialization (when we try to get the setting of for the
4397 console baudrate). You *MUST* have mapped your NVRAM area then, or
4400 Please note that even with NVRAM we still use a copy of the
4401 environment in RAM: we could work on NVRAM directly, but we want to
4402 keep settings there always unmodified except somebody uses "saveenv"
4403 to save the current settings.
4406 - CONFIG_ENV_IS_IN_EEPROM:
4408 Use this if you have an EEPROM or similar serial access
4409 device and a driver for it.
4411 - CONFIG_ENV_OFFSET:
4414 These two #defines specify the offset and size of the
4415 environment area within the total memory of your EEPROM.
4417 - CONFIG_SYS_I2C_EEPROM_ADDR:
4418 If defined, specified the chip address of the EEPROM device.
4419 The default address is zero.
4421 - CONFIG_SYS_I2C_EEPROM_BUS:
4422 If defined, specified the i2c bus of the EEPROM device.
4424 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4425 If defined, the number of bits used to address bytes in a
4426 single page in the EEPROM device. A 64 byte page, for example
4427 would require six bits.
4429 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4430 If defined, the number of milliseconds to delay between
4431 page writes. The default is zero milliseconds.
4433 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4434 The length in bytes of the EEPROM memory array address. Note
4435 that this is NOT the chip address length!
4437 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4438 EEPROM chips that implement "address overflow" are ones
4439 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4440 address and the extra bits end up in the "chip address" bit
4441 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4444 Note that we consider the length of the address field to
4445 still be one byte because the extra address bits are hidden
4446 in the chip address.
4448 - CONFIG_SYS_EEPROM_SIZE:
4449 The size in bytes of the EEPROM device.
4451 - CONFIG_ENV_EEPROM_IS_ON_I2C
4452 define this, if you have I2C and SPI activated, and your
4453 EEPROM, which holds the environment, is on the I2C bus.
4455 - CONFIG_I2C_ENV_EEPROM_BUS
4456 if you have an Environment on an EEPROM reached over
4457 I2C muxes, you can define here, how to reach this
4458 EEPROM. For example:
4460 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4462 EEPROM which holds the environment, is reached over
4463 a pca9547 i2c mux with address 0x70, channel 3.
4465 - CONFIG_ENV_IS_IN_DATAFLASH:
4467 Define this if you have a DataFlash memory device which you
4468 want to use for the environment.
4470 - CONFIG_ENV_OFFSET:
4474 These three #defines specify the offset and size of the
4475 environment area within the total memory of your DataFlash placed
4476 at the specified address.
4478 - CONFIG_ENV_IS_IN_SPI_FLASH:
4480 Define this if you have a SPI Flash memory device which you
4481 want to use for the environment.
4483 - CONFIG_ENV_OFFSET:
4486 These two #defines specify the offset and size of the
4487 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4488 aligned to an erase sector boundary.
4490 - CONFIG_ENV_SECT_SIZE:
4492 Define the SPI flash's sector size.
4494 - CONFIG_ENV_OFFSET_REDUND (optional):
4496 This setting describes a second storage area of CONFIG_ENV_SIZE
4497 size used to hold a redundant copy of the environment data, so
4498 that there is a valid backup copy in case there is a power failure
4499 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4500 aligned to an erase sector boundary.
4502 - CONFIG_ENV_SPI_BUS (optional):
4503 - CONFIG_ENV_SPI_CS (optional):
4505 Define the SPI bus and chip select. If not defined they will be 0.
4507 - CONFIG_ENV_SPI_MAX_HZ (optional):
4509 Define the SPI max work clock. If not defined then use 1MHz.
4511 - CONFIG_ENV_SPI_MODE (optional):
4513 Define the SPI work mode. If not defined then use SPI_MODE_3.
4515 - CONFIG_ENV_IS_IN_REMOTE:
4517 Define this if you have a remote memory space which you
4518 want to use for the local device's environment.
4523 These two #defines specify the address and size of the
4524 environment area within the remote memory space. The
4525 local device can get the environment from remote memory
4526 space by SRIO or PCIE links.
4528 BE CAREFUL! For some special cases, the local device can not use
4529 "saveenv" command. For example, the local device will get the
4530 environment stored in a remote NOR flash by SRIO or PCIE link,
4531 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4533 - CONFIG_ENV_IS_IN_NAND:
4535 Define this if you have a NAND device which you want to use
4536 for the environment.
4538 - CONFIG_ENV_OFFSET:
4541 These two #defines specify the offset and size of the environment
4542 area within the first NAND device. CONFIG_ENV_OFFSET must be
4543 aligned to an erase block boundary.
4545 - CONFIG_ENV_OFFSET_REDUND (optional):
4547 This setting describes a second storage area of CONFIG_ENV_SIZE
4548 size used to hold a redundant copy of the environment data, so
4549 that there is a valid backup copy in case there is a power failure
4550 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4551 aligned to an erase block boundary.
4553 - CONFIG_ENV_RANGE (optional):
4555 Specifies the length of the region in which the environment
4556 can be written. This should be a multiple of the NAND device's
4557 block size. Specifying a range with more erase blocks than
4558 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4559 the range to be avoided.
4561 - CONFIG_ENV_OFFSET_OOB (optional):
4563 Enables support for dynamically retrieving the offset of the
4564 environment from block zero's out-of-band data. The
4565 "nand env.oob" command can be used to record this offset.
4566 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4567 using CONFIG_ENV_OFFSET_OOB.
4569 - CONFIG_NAND_ENV_DST
4571 Defines address in RAM to which the nand_spl code should copy the
4572 environment. If redundant environment is used, it will be copied to
4573 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4575 - CONFIG_ENV_IS_IN_UBI:
4577 Define this if you have an UBI volume that you want to use for the
4578 environment. This has the benefit of wear-leveling the environment
4579 accesses, which is important on NAND.
4581 - CONFIG_ENV_UBI_PART:
4583 Define this to a string that is the mtd partition containing the UBI.
4585 - CONFIG_ENV_UBI_VOLUME:
4587 Define this to the name of the volume that you want to store the
4590 - CONFIG_ENV_UBI_VOLUME_REDUND:
4592 Define this to the name of another volume to store a second copy of
4593 the environment in. This will enable redundant environments in UBI.
4594 It is assumed that both volumes are in the same MTD partition.
4596 - CONFIG_UBI_SILENCE_MSG
4597 - CONFIG_UBIFS_SILENCE_MSG
4599 You will probably want to define these to avoid a really noisy system
4600 when storing the env in UBI.
4602 - CONFIG_ENV_IS_IN_FAT:
4603 Define this if you want to use the FAT file system for the environment.
4605 - FAT_ENV_INTERFACE:
4607 Define this to a string that is the name of the block device.
4609 - FAT_ENV_DEV_AND_PART:
4611 Define this to a string to specify the partition of the device. It can
4614 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4615 - "D:P": device D partition P. Error occurs if device D has no
4618 - "D" or "D:": device D partition 1 if device D has partition
4619 table, or the whole device D if has no partition
4621 - "D:auto": first partition in device D with bootable flag set.
4622 If none, first valid partition in device D. If no
4623 partition table then means device D.
4627 It's a string of the FAT file name. This file use to store the
4631 This should be defined. Otherwise it cannot save the environment file.
4633 - CONFIG_ENV_IS_IN_MMC:
4635 Define this if you have an MMC device which you want to use for the
4638 - CONFIG_SYS_MMC_ENV_DEV:
4640 Specifies which MMC device the environment is stored in.
4642 - CONFIG_SYS_MMC_ENV_PART (optional):
4644 Specifies which MMC partition the environment is stored in. If not
4645 set, defaults to partition 0, the user area. Common values might be
4646 1 (first MMC boot partition), 2 (second MMC boot partition).
4648 - CONFIG_ENV_OFFSET:
4651 These two #defines specify the offset and size of the environment
4652 area within the specified MMC device.
4654 If offset is positive (the usual case), it is treated as relative to
4655 the start of the MMC partition. If offset is negative, it is treated
4656 as relative to the end of the MMC partition. This can be useful if
4657 your board may be fitted with different MMC devices, which have
4658 different sizes for the MMC partitions, and you always want the
4659 environment placed at the very end of the partition, to leave the
4660 maximum possible space before it, to store other data.
4662 These two values are in units of bytes, but must be aligned to an
4663 MMC sector boundary.
4665 - CONFIG_ENV_OFFSET_REDUND (optional):
4667 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4668 hold a redundant copy of the environment data. This provides a
4669 valid backup copy in case the other copy is corrupted, e.g. due
4670 to a power failure during a "saveenv" operation.
4672 This value may also be positive or negative; this is handled in the
4673 same way as CONFIG_ENV_OFFSET.
4675 This value is also in units of bytes, but must also be aligned to
4676 an MMC sector boundary.
4678 - CONFIG_ENV_SIZE_REDUND (optional):
4680 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4681 set. If this value is set, it must be set to the same value as
4684 - CONFIG_SYS_SPI_INIT_OFFSET
4686 Defines offset to the initial SPI buffer area in DPRAM. The
4687 area is used at an early stage (ROM part) if the environment
4688 is configured to reside in the SPI EEPROM: We need a 520 byte
4689 scratch DPRAM area. It is used between the two initialization
4690 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4691 to be a good choice since it makes it far enough from the
4692 start of the data area as well as from the stack pointer.
4694 Please note that the environment is read-only until the monitor
4695 has been relocated to RAM and a RAM copy of the environment has been
4696 created; also, when using EEPROM you will have to use getenv_f()
4697 until then to read environment variables.
4699 The environment is protected by a CRC32 checksum. Before the monitor
4700 is relocated into RAM, as a result of a bad CRC you will be working
4701 with the compiled-in default environment - *silently*!!! [This is
4702 necessary, because the first environment variable we need is the
4703 "baudrate" setting for the console - if we have a bad CRC, we don't
4704 have any device yet where we could complain.]
4706 Note: once the monitor has been relocated, then it will complain if
4707 the default environment is used; a new CRC is computed as soon as you
4708 use the "saveenv" command to store a valid environment.
4710 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4711 Echo the inverted Ethernet link state to the fault LED.
4713 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4714 also needs to be defined.
4716 - CONFIG_SYS_FAULT_MII_ADDR:
4717 MII address of the PHY to check for the Ethernet link state.
4719 - CONFIG_NS16550_MIN_FUNCTIONS:
4720 Define this if you desire to only have use of the NS16550_init
4721 and NS16550_putc functions for the serial driver located at
4722 drivers/serial/ns16550.c. This option is useful for saving
4723 space for already greatly restricted images, including but not
4724 limited to NAND_SPL configurations.
4726 - CONFIG_DISPLAY_BOARDINFO
4727 Display information about the board that U-Boot is running on
4728 when U-Boot starts up. The board function checkboard() is called
4731 - CONFIG_DISPLAY_BOARDINFO_LATE
4732 Similar to the previous option, but display this information
4733 later, once stdio is running and output goes to the LCD, if
4736 - CONFIG_BOARD_SIZE_LIMIT:
4737 Maximum size of the U-Boot image. When defined, the
4738 build system checks that the actual size does not
4741 Low Level (hardware related) configuration options:
4742 ---------------------------------------------------
4744 - CONFIG_SYS_CACHELINE_SIZE:
4745 Cache Line Size of the CPU.
4747 - CONFIG_SYS_DEFAULT_IMMR:
4748 Default address of the IMMR after system reset.
4750 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4751 and RPXsuper) to be able to adjust the position of
4752 the IMMR register after a reset.
4754 - CONFIG_SYS_CCSRBAR_DEFAULT:
4755 Default (power-on reset) physical address of CCSR on Freescale
4758 - CONFIG_SYS_CCSRBAR:
4759 Virtual address of CCSR. On a 32-bit build, this is typically
4760 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4762 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4763 for cross-platform code that uses that macro instead.
4765 - CONFIG_SYS_CCSRBAR_PHYS:
4766 Physical address of CCSR. CCSR can be relocated to a new
4767 physical address, if desired. In this case, this macro should
4768 be set to that address. Otherwise, it should be set to the
4769 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4770 is typically relocated on 36-bit builds. It is recommended
4771 that this macro be defined via the _HIGH and _LOW macros:
4773 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4774 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4776 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4777 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4778 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4779 used in assembly code, so it must not contain typecasts or
4780 integer size suffixes (e.g. "ULL").
4782 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4783 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4784 used in assembly code, so it must not contain typecasts or
4785 integer size suffixes (e.g. "ULL").
4787 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4788 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4789 forced to a value that ensures that CCSR is not relocated.
4791 - Floppy Disk Support:
4792 CONFIG_SYS_FDC_DRIVE_NUMBER
4794 the default drive number (default value 0)
4796 CONFIG_SYS_ISA_IO_STRIDE
4798 defines the spacing between FDC chipset registers
4801 CONFIG_SYS_ISA_IO_OFFSET
4803 defines the offset of register from address. It
4804 depends on which part of the data bus is connected to
4805 the FDC chipset. (default value 0)
4807 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4808 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4811 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4812 fdc_hw_init() is called at the beginning of the FDC
4813 setup. fdc_hw_init() must be provided by the board
4814 source code. It is used to make hardware-dependent
4818 Most IDE controllers were designed to be connected with PCI
4819 interface. Only few of them were designed for AHB interface.
4820 When software is doing ATA command and data transfer to
4821 IDE devices through IDE-AHB controller, some additional
4822 registers accessing to these kind of IDE-AHB controller
4825 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4826 DO NOT CHANGE unless you know exactly what you're
4827 doing! (11-4) [MPC8xx/82xx systems only]
4829 - CONFIG_SYS_INIT_RAM_ADDR:
4831 Start address of memory area that can be used for
4832 initial data and stack; please note that this must be
4833 writable memory that is working WITHOUT special
4834 initialization, i. e. you CANNOT use normal RAM which
4835 will become available only after programming the
4836 memory controller and running certain initialization
4839 U-Boot uses the following memory types:
4840 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4841 - MPC824X: data cache
4842 - PPC4xx: data cache
4844 - CONFIG_SYS_GBL_DATA_OFFSET:
4846 Offset of the initial data structure in the memory
4847 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4848 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4849 data is located at the end of the available space
4850 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4851 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4852 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4853 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4856 On the MPC824X (or other systems that use the data
4857 cache for initial memory) the address chosen for
4858 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4859 point to an otherwise UNUSED address space between
4860 the top of RAM and the start of the PCI space.
4862 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4864 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4866 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4868 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4870 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4872 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4874 - CONFIG_SYS_OR_TIMING_SDRAM:
4877 - CONFIG_SYS_MAMR_PTA:
4878 periodic timer for refresh
4880 - CONFIG_SYS_DER: Debug Event Register (37-47)
4882 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4883 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4884 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4885 CONFIG_SYS_BR1_PRELIM:
4886 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4888 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4889 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4890 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4891 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4893 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4894 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4895 Machine Mode Register and Memory Periodic Timer
4896 Prescaler definitions (SDRAM timing)
4898 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4899 enable I2C microcode relocation patch (MPC8xx);
4900 define relocation offset in DPRAM [DSP2]
4902 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4903 enable SMC microcode relocation patch (MPC8xx);
4904 define relocation offset in DPRAM [SMC1]
4906 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4907 enable SPI microcode relocation patch (MPC8xx);
4908 define relocation offset in DPRAM [SCC4]
4910 - CONFIG_SYS_USE_OSCCLK:
4911 Use OSCM clock mode on MBX8xx board. Be careful,
4912 wrong setting might damage your board. Read
4913 doc/README.MBX before setting this variable!
4915 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4916 Offset of the bootmode word in DPRAM used by post
4917 (Power On Self Tests). This definition overrides
4918 #define'd default value in commproc.h resp.
4921 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4922 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4923 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4924 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4925 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4926 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4927 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4928 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4929 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4931 - CONFIG_PCI_DISABLE_PCIE:
4932 Disable PCI-Express on systems where it is supported but not
4935 - CONFIG_PCI_ENUM_ONLY
4936 Only scan through and get the devices on the buses.
4937 Don't do any setup work, presumably because someone or
4938 something has already done it, and we don't need to do it
4939 a second time. Useful for platforms that are pre-booted
4940 by coreboot or similar.
4942 - CONFIG_PCI_INDIRECT_BRIDGE:
4943 Enable support for indirect PCI bridges.
4946 Chip has SRIO or not
4949 Board has SRIO 1 port available
4952 Board has SRIO 2 port available
4954 - CONFIG_SRIO_PCIE_BOOT_MASTER
4955 Board can support master function for Boot from SRIO and PCIE
4957 - CONFIG_SYS_SRIOn_MEM_VIRT:
4958 Virtual Address of SRIO port 'n' memory region
4960 - CONFIG_SYS_SRIOn_MEM_PHYS:
4961 Physical Address of SRIO port 'n' memory region
4963 - CONFIG_SYS_SRIOn_MEM_SIZE:
4964 Size of SRIO port 'n' memory region
4966 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4967 Defined to tell the NAND controller that the NAND chip is using
4969 Not all NAND drivers use this symbol.
4970 Example of drivers that use it:
4971 - drivers/mtd/nand/ndfc.c
4972 - drivers/mtd/nand/mxc_nand.c
4974 - CONFIG_SYS_NDFC_EBC0_CFG
4975 Sets the EBC0_CFG register for the NDFC. If not defined
4976 a default value will be used.
4979 Get DDR timing information from an I2C EEPROM. Common
4980 with pluggable memory modules such as SODIMMs
4983 I2C address of the SPD EEPROM
4985 - CONFIG_SYS_SPD_BUS_NUM
4986 If SPD EEPROM is on an I2C bus other than the first
4987 one, specify here. Note that the value must resolve
4988 to something your driver can deal with.
4990 - CONFIG_SYS_DDR_RAW_TIMING
4991 Get DDR timing information from other than SPD. Common with
4992 soldered DDR chips onboard without SPD. DDR raw timing
4993 parameters are extracted from datasheet and hard-coded into
4994 header files or board specific files.
4996 - CONFIG_FSL_DDR_INTERACTIVE
4997 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4999 - CONFIG_FSL_DDR_SYNC_REFRESH
5000 Enable sync of refresh for multiple controllers.
5002 - CONFIG_FSL_DDR_BIST
5003 Enable built-in memory test for Freescale DDR controllers.
5005 - CONFIG_SYS_83XX_DDR_USES_CS0
5006 Only for 83xx systems. If specified, then DDR should
5007 be configured using CS0 and CS1 instead of CS2 and CS3.
5009 - CONFIG_ETHER_ON_FEC[12]
5010 Define to enable FEC[12] on a 8xx series processor.
5012 - CONFIG_FEC[12]_PHY
5013 Define to the hardcoded PHY address which corresponds
5014 to the given FEC; i. e.
5015 #define CONFIG_FEC1_PHY 4
5016 means that the PHY with address 4 is connected to FEC1
5018 When set to -1, means to probe for first available.
5020 - CONFIG_FEC[12]_PHY_NORXERR
5021 The PHY does not have a RXERR line (RMII only).
5022 (so program the FEC to ignore it).
5025 Enable RMII mode for all FECs.
5026 Note that this is a global option, we can't
5027 have one FEC in standard MII mode and another in RMII mode.
5029 - CONFIG_CRC32_VERIFY
5030 Add a verify option to the crc32 command.
5033 => crc32 -v <address> <count> <crc32>
5035 Where address/count indicate a memory area
5036 and crc32 is the correct crc32 which the
5040 Add the "loopw" memory command. This only takes effect if
5041 the memory commands are activated globally (CONFIG_CMD_MEM).
5044 Add the "mdc" and "mwc" memory commands. These are cyclic
5049 This command will print 4 bytes (10,11,12,13) each 500 ms.
5051 => mwc.l 100 12345678 10
5052 This command will write 12345678 to address 100 all 10 ms.
5054 This only takes effect if the memory commands are activated
5055 globally (CONFIG_CMD_MEM).
5057 - CONFIG_SKIP_LOWLEVEL_INIT
5058 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5059 low level initializations (like setting up the memory
5060 controller) are omitted and/or U-Boot does not
5061 relocate itself into RAM.
5063 Normally this variable MUST NOT be defined. The only
5064 exception is when U-Boot is loaded (to RAM) by some
5065 other boot loader or by a debugger which performs
5066 these initializations itself.
5069 Modifies the behaviour of start.S when compiling a loader
5070 that is executed before the actual U-Boot. E.g. when
5071 compiling a NAND SPL.
5074 Modifies the behaviour of start.S when compiling a loader
5075 that is executed after the SPL and before the actual U-Boot.
5076 It is loaded by the SPL.
5078 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5079 Only for 85xx systems. If this variable is specified, the section
5080 .resetvec is not kept and the section .bootpg is placed in the
5081 previous 4k of the .text section.
5083 - CONFIG_ARCH_MAP_SYSMEM
5084 Generally U-Boot (and in particular the md command) uses
5085 effective address. It is therefore not necessary to regard
5086 U-Boot address as virtual addresses that need to be translated
5087 to physical addresses. However, sandbox requires this, since
5088 it maintains its own little RAM buffer which contains all
5089 addressable memory. This option causes some memory accesses
5090 to be mapped through map_sysmem() / unmap_sysmem().
5092 - CONFIG_USE_ARCH_MEMCPY
5093 CONFIG_USE_ARCH_MEMSET
5094 If these options are used a optimized version of memcpy/memset will
5095 be used if available. These functions may be faster under some
5096 conditions but may increase the binary size.
5098 - CONFIG_X86_RESET_VECTOR
5099 If defined, the x86 reset vector code is included. This is not
5100 needed when U-Boot is running from Coreboot.
5103 Defines the MPU clock speed (in MHz).
5105 NOTE : currently only supported on AM335x platforms.
5107 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5108 Enables the RTC32K OSC on AM33xx based plattforms
5110 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5111 Option to disable subpage write in NAND driver
5112 driver that uses this:
5113 drivers/mtd/nand/davinci_nand.c
5115 Freescale QE/FMAN Firmware Support:
5116 -----------------------------------
5118 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5119 loading of "firmware", which is encoded in the QE firmware binary format.
5120 This firmware often needs to be loaded during U-Boot booting, so macros
5121 are used to identify the storage device (NOR flash, SPI, etc) and the address
5124 - CONFIG_SYS_FMAN_FW_ADDR
5125 The address in the storage device where the FMAN microcode is located. The
5126 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5129 - CONFIG_SYS_QE_FW_ADDR
5130 The address in the storage device where the QE microcode is located. The
5131 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5134 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5135 The maximum possible size of the firmware. The firmware binary format
5136 has a field that specifies the actual size of the firmware, but it
5137 might not be possible to read any part of the firmware unless some
5138 local storage is allocated to hold the entire firmware first.
5140 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5141 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5142 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5143 virtual address in NOR flash.
5145 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5146 Specifies that QE/FMAN firmware is located in NAND flash.
5147 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5149 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5150 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5151 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5153 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5154 Specifies that QE/FMAN firmware is located on the primary SPI
5155 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5157 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5158 Specifies that QE/FMAN firmware is located in the remote (master)
5159 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5160 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5161 window->master inbound window->master LAW->the ucode address in
5162 master's memory space.
5164 Freescale Layerscape Management Complex Firmware Support:
5165 ---------------------------------------------------------
5166 The Freescale Layerscape Management Complex (MC) supports the loading of
5168 This firmware often needs to be loaded during U-Boot booting, so macros
5169 are used to identify the storage device (NOR flash, SPI, etc) and the address
5172 - CONFIG_FSL_MC_ENET
5173 Enable the MC driver for Layerscape SoCs.
5175 - CONFIG_SYS_LS_MC_FW_ADDR
5176 The address in the storage device where the firmware is located. The
5177 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5180 - CONFIG_SYS_LS_MC_FW_LENGTH
5181 The maximum possible size of the firmware. The firmware binary format
5182 has a field that specifies the actual size of the firmware, but it
5183 might not be possible to read any part of the firmware unless some
5184 local storage is allocated to hold the entire firmware first.
5186 - CONFIG_SYS_LS_MC_FW_IN_NOR
5187 Specifies that MC firmware is located in NOR flash, mapped as
5188 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5189 virtual address in NOR flash.
5191 Freescale Layerscape Debug Server Support:
5192 -------------------------------------------
5193 The Freescale Layerscape Debug Server Support supports the loading of
5194 "Debug Server firmware" and triggering SP boot-rom.
5195 This firmware often needs to be loaded during U-Boot booting.
5197 - CONFIG_FSL_DEBUG_SERVER
5198 Enable the Debug Server for Layerscape SoCs.
5200 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5201 Define minimum DDR size required for debug server image
5203 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5204 Define minimum DDR size to be hided from top of the DDR memory
5209 In order to achieve reproducible builds, timestamps used in the U-Boot build
5210 process have to be set to a fixed value.
5212 This is done using the SOURCE_DATE_EPOCH environment variable.
5213 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5214 option for U-Boot or an environment variable in U-Boot.
5216 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5218 Building the Software:
5219 ======================
5221 Building U-Boot has been tested in several native build environments
5222 and in many different cross environments. Of course we cannot support
5223 all possibly existing versions of cross development tools in all
5224 (potentially obsolete) versions. In case of tool chain problems we
5225 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5226 which is extensively used to build and test U-Boot.
5228 If you are not using a native environment, it is assumed that you
5229 have GNU cross compiling tools available in your path. In this case,
5230 you must set the environment variable CROSS_COMPILE in your shell.
5231 Note that no changes to the Makefile or any other source files are
5232 necessary. For example using the ELDK on a 4xx CPU, please enter:
5234 $ CROSS_COMPILE=ppc_4xx-
5235 $ export CROSS_COMPILE
5237 Note: If you wish to generate Windows versions of the utilities in
5238 the tools directory you can use the MinGW toolchain
5239 (http://www.mingw.org). Set your HOST tools to the MinGW
5240 toolchain and execute 'make tools'. For example:
5242 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5244 Binaries such as tools/mkimage.exe will be created which can
5245 be executed on computers running Windows.
5247 U-Boot is intended to be simple to build. After installing the
5248 sources you must configure U-Boot for one specific board type. This
5253 where "NAME_defconfig" is the name of one of the existing configu-
5254 rations; see boards.cfg for supported names.
5256 Note: for some board special configuration names may exist; check if
5257 additional information is available from the board vendor; for
5258 instance, the TQM823L systems are available without (standard)
5259 or with LCD support. You can select such additional "features"
5260 when choosing the configuration, i. e.
5262 make TQM823L_defconfig
5263 - will configure for a plain TQM823L, i. e. no LCD support
5265 make TQM823L_LCD_defconfig
5266 - will configure for a TQM823L with U-Boot console on LCD
5271 Finally, type "make all", and you should get some working U-Boot
5272 images ready for download to / installation on your system:
5274 - "u-boot.bin" is a raw binary image
5275 - "u-boot" is an image in ELF binary format
5276 - "u-boot.srec" is in Motorola S-Record format
5278 By default the build is performed locally and the objects are saved
5279 in the source directory. One of the two methods can be used to change
5280 this behavior and build U-Boot to some external directory:
5282 1. Add O= to the make command line invocations:
5284 make O=/tmp/build distclean
5285 make O=/tmp/build NAME_defconfig
5286 make O=/tmp/build all
5288 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5290 export KBUILD_OUTPUT=/tmp/build
5295 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5299 Please be aware that the Makefiles assume you are using GNU make, so
5300 for instance on NetBSD you might need to use "gmake" instead of
5304 If the system board that you have is not listed, then you will need
5305 to port U-Boot to your hardware platform. To do this, follow these
5308 1. Add a new configuration option for your board to the toplevel
5309 "boards.cfg" file, using the existing entries as examples.
5310 Follow the instructions there to keep the boards in order.
5311 2. Create a new directory to hold your board specific code. Add any
5312 files you need. In your board directory, you will need at least
5313 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5314 3. Create a new configuration file "include/configs/<board>.h" for
5316 3. If you're porting U-Boot to a new CPU, then also create a new
5317 directory to hold your CPU specific code. Add any files you need.
5318 4. Run "make <board>_defconfig" with your new name.
5319 5. Type "make", and you should get a working "u-boot.srec" file
5320 to be installed on your target system.
5321 6. Debug and solve any problems that might arise.
5322 [Of course, this last step is much harder than it sounds.]
5325 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5326 ==============================================================
5328 If you have modified U-Boot sources (for instance added a new board
5329 or support for new devices, a new CPU, etc.) you are expected to
5330 provide feedback to the other developers. The feedback normally takes
5331 the form of a "patch", i. e. a context diff against a certain (latest
5332 official or latest in the git repository) version of U-Boot sources.
5334 But before you submit such a patch, please verify that your modifi-
5335 cation did not break existing code. At least make sure that *ALL* of
5336 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5337 just run the "MAKEALL" script, which will configure and build U-Boot
5338 for ALL supported system. Be warned, this will take a while. You can
5339 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5340 environment variable to the script, i. e. to use the ELDK cross tools
5343 CROSS_COMPILE=ppc_8xx- MAKEALL
5345 or to build on a native PowerPC system you can type
5347 CROSS_COMPILE=' ' MAKEALL
5349 When using the MAKEALL script, the default behaviour is to build
5350 U-Boot in the source directory. This location can be changed by
5351 setting the BUILD_DIR environment variable. Also, for each target
5352 built, the MAKEALL script saves two log files (<target>.ERR and
5353 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5354 location can be changed by setting the MAKEALL_LOGDIR environment
5355 variable. For example:
5357 export BUILD_DIR=/tmp/build
5358 export MAKEALL_LOGDIR=/tmp/log
5359 CROSS_COMPILE=ppc_8xx- MAKEALL
5361 With the above settings build objects are saved in the /tmp/build,
5362 log files are saved in the /tmp/log and the source tree remains clean
5363 during the whole build process.
5366 See also "U-Boot Porting Guide" below.
5369 Monitor Commands - Overview:
5370 ============================
5372 go - start application at address 'addr'
5373 run - run commands in an environment variable
5374 bootm - boot application image from memory
5375 bootp - boot image via network using BootP/TFTP protocol
5376 bootz - boot zImage from memory
5377 tftpboot- boot image via network using TFTP protocol
5378 and env variables "ipaddr" and "serverip"
5379 (and eventually "gatewayip")
5380 tftpput - upload a file via network using TFTP protocol
5381 rarpboot- boot image via network using RARP/TFTP protocol
5382 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5383 loads - load S-Record file over serial line
5384 loadb - load binary file over serial line (kermit mode)
5386 mm - memory modify (auto-incrementing)
5387 nm - memory modify (constant address)
5388 mw - memory write (fill)
5390 cmp - memory compare
5391 crc32 - checksum calculation
5392 i2c - I2C sub-system
5393 sspi - SPI utility commands
5394 base - print or set address offset
5395 printenv- print environment variables
5396 setenv - set environment variables
5397 saveenv - save environment variables to persistent storage
5398 protect - enable or disable FLASH write protection
5399 erase - erase FLASH memory
5400 flinfo - print FLASH memory information
5401 nand - NAND memory operations (see doc/README.nand)
5402 bdinfo - print Board Info structure
5403 iminfo - print header information for application image
5404 coninfo - print console devices and informations
5405 ide - IDE sub-system
5406 loop - infinite loop on address range
5407 loopw - infinite write loop on address range
5408 mtest - simple RAM test
5409 icache - enable or disable instruction cache
5410 dcache - enable or disable data cache
5411 reset - Perform RESET of the CPU
5412 echo - echo args to console
5413 version - print monitor version
5414 help - print online help
5415 ? - alias for 'help'
5418 Monitor Commands - Detailed Description:
5419 ========================================
5423 For now: just type "help <command>".
5426 Environment Variables:
5427 ======================
5429 U-Boot supports user configuration using Environment Variables which
5430 can be made persistent by saving to Flash memory.
5432 Environment Variables are set using "setenv", printed using
5433 "printenv", and saved to Flash using "saveenv". Using "setenv"
5434 without a value can be used to delete a variable from the
5435 environment. As long as you don't save the environment you are
5436 working with an in-memory copy. In case the Flash area containing the
5437 environment is erased by accident, a default environment is provided.
5439 Some configuration options can be set using Environment Variables.
5441 List of environment variables (most likely not complete):
5443 baudrate - see CONFIG_BAUDRATE
5445 bootdelay - see CONFIG_BOOTDELAY
5447 bootcmd - see CONFIG_BOOTCOMMAND
5449 bootargs - Boot arguments when booting an RTOS image
5451 bootfile - Name of the image to load with TFTP
5453 bootm_low - Memory range available for image processing in the bootm
5454 command can be restricted. This variable is given as
5455 a hexadecimal number and defines lowest address allowed
5456 for use by the bootm command. See also "bootm_size"
5457 environment variable. Address defined by "bootm_low" is
5458 also the base of the initial memory mapping for the Linux
5459 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5462 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5463 This variable is given as a hexadecimal number and it
5464 defines the size of the memory region starting at base
5465 address bootm_low that is accessible by the Linux kernel
5466 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5467 as the default value if it is defined, and bootm_size is
5470 bootm_size - Memory range available for image processing in the bootm
5471 command can be restricted. This variable is given as
5472 a hexadecimal number and defines the size of the region
5473 allowed for use by the bootm command. See also "bootm_low"
5474 environment variable.
5476 updatefile - Location of the software update file on a TFTP server, used
5477 by the automatic software update feature. Please refer to
5478 documentation in doc/README.update for more details.
5480 autoload - if set to "no" (any string beginning with 'n'),
5481 "bootp" will just load perform a lookup of the
5482 configuration from the BOOTP server, but not try to
5483 load any image using TFTP
5485 autostart - if set to "yes", an image loaded using the "bootp",
5486 "rarpboot", "tftpboot" or "diskboot" commands will
5487 be automatically started (by internally calling
5490 If set to "no", a standalone image passed to the
5491 "bootm" command will be copied to the load address
5492 (and eventually uncompressed), but NOT be started.
5493 This can be used to load and uncompress arbitrary
5496 fdt_high - if set this restricts the maximum address that the
5497 flattened device tree will be copied into upon boot.
5498 For example, if you have a system with 1 GB memory
5499 at physical address 0x10000000, while Linux kernel
5500 only recognizes the first 704 MB as low memory, you
5501 may need to set fdt_high as 0x3C000000 to have the
5502 device tree blob be copied to the maximum address
5503 of the 704 MB low memory, so that Linux kernel can
5504 access it during the boot procedure.
5506 If this is set to the special value 0xFFFFFFFF then
5507 the fdt will not be copied at all on boot. For this
5508 to work it must reside in writable memory, have
5509 sufficient padding on the end of it for u-boot to
5510 add the information it needs into it, and the memory
5511 must be accessible by the kernel.
5513 fdtcontroladdr- if set this is the address of the control flattened
5514 device tree used by U-Boot when CONFIG_OF_CONTROL is
5517 i2cfast - (PPC405GP|PPC405EP only)
5518 if set to 'y' configures Linux I2C driver for fast
5519 mode (400kHZ). This environment variable is used in
5520 initialization code. So, for changes to be effective
5521 it must be saved and board must be reset.
5523 initrd_high - restrict positioning of initrd images:
5524 If this variable is not set, initrd images will be
5525 copied to the highest possible address in RAM; this
5526 is usually what you want since it allows for
5527 maximum initrd size. If for some reason you want to
5528 make sure that the initrd image is loaded below the
5529 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5530 variable to a value of "no" or "off" or "0".
5531 Alternatively, you can set it to a maximum upper
5532 address to use (U-Boot will still check that it
5533 does not overwrite the U-Boot stack and data).
5535 For instance, when you have a system with 16 MB
5536 RAM, and want to reserve 4 MB from use by Linux,
5537 you can do this by adding "mem=12M" to the value of
5538 the "bootargs" variable. However, now you must make
5539 sure that the initrd image is placed in the first
5540 12 MB as well - this can be done with
5542 setenv initrd_high 00c00000
5544 If you set initrd_high to 0xFFFFFFFF, this is an
5545 indication to U-Boot that all addresses are legal
5546 for the Linux kernel, including addresses in flash
5547 memory. In this case U-Boot will NOT COPY the
5548 ramdisk at all. This may be useful to reduce the
5549 boot time on your system, but requires that this
5550 feature is supported by your Linux kernel.
5552 ipaddr - IP address; needed for tftpboot command
5554 loadaddr - Default load address for commands like "bootp",
5555 "rarpboot", "tftpboot", "loadb" or "diskboot"
5557 loads_echo - see CONFIG_LOADS_ECHO
5559 serverip - TFTP server IP address; needed for tftpboot command
5561 bootretry - see CONFIG_BOOT_RETRY_TIME
5563 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5565 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5567 ethprime - controls which interface is used first.
5569 ethact - controls which interface is currently active.
5570 For example you can do the following
5572 => setenv ethact FEC
5573 => ping 192.168.0.1 # traffic sent on FEC
5574 => setenv ethact SCC
5575 => ping 10.0.0.1 # traffic sent on SCC
5577 ethrotate - When set to "no" U-Boot does not go through all
5578 available network interfaces.
5579 It just stays at the currently selected interface.
5581 netretry - When set to "no" each network operation will
5582 either succeed or fail without retrying.
5583 When set to "once" the network operation will
5584 fail when all the available network interfaces
5585 are tried once without success.
5586 Useful on scripts which control the retry operation
5589 npe_ucode - set load address for the NPE microcode
5591 silent_linux - If set then Linux will be told to boot silently, by
5592 changing the console to be empty. If "yes" it will be
5593 made silent. If "no" it will not be made silent. If
5594 unset, then it will be made silent if the U-Boot console
5597 tftpsrcport - If this is set, the value is used for TFTP's
5600 tftpdstport - If this is set, the value is used for TFTP's UDP
5601 destination port instead of the Well Know Port 69.
5603 tftpblocksize - Block size to use for TFTP transfers; if not set,
5604 we use the TFTP server's default block size
5606 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5607 seconds, minimum value is 1000 = 1 second). Defines
5608 when a packet is considered to be lost so it has to
5609 be retransmitted. The default is 5000 = 5 seconds.
5610 Lowering this value may make downloads succeed
5611 faster in networks with high packet loss rates or
5612 with unreliable TFTP servers.
5614 vlan - When set to a value < 4095 the traffic over
5615 Ethernet is encapsulated/received over 802.1q
5618 The following image location variables contain the location of images
5619 used in booting. The "Image" column gives the role of the image and is
5620 not an environment variable name. The other columns are environment
5621 variable names. "File Name" gives the name of the file on a TFTP
5622 server, "RAM Address" gives the location in RAM the image will be
5623 loaded to, and "Flash Location" gives the image's address in NOR
5624 flash or offset in NAND flash.
5626 *Note* - these variables don't have to be defined for all boards, some
5627 boards currently use other variables for these purposes, and some
5628 boards use these variables for other purposes.
5630 Image File Name RAM Address Flash Location
5631 ----- --------- ----------- --------------
5632 u-boot u-boot u-boot_addr_r u-boot_addr
5633 Linux kernel bootfile kernel_addr_r kernel_addr
5634 device tree blob fdtfile fdt_addr_r fdt_addr
5635 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5637 The following environment variables may be used and automatically
5638 updated by the network boot commands ("bootp" and "rarpboot"),
5639 depending the information provided by your boot server:
5641 bootfile - see above
5642 dnsip - IP address of your Domain Name Server
5643 dnsip2 - IP address of your secondary Domain Name Server
5644 gatewayip - IP address of the Gateway (Router) to use
5645 hostname - Target hostname
5647 netmask - Subnet Mask
5648 rootpath - Pathname of the root filesystem on the NFS server
5649 serverip - see above
5652 There are two special Environment Variables:
5654 serial# - contains hardware identification information such
5655 as type string and/or serial number
5656 ethaddr - Ethernet address
5658 These variables can be set only once (usually during manufacturing of
5659 the board). U-Boot refuses to delete or overwrite these variables
5660 once they have been set once.
5663 Further special Environment Variables:
5665 ver - Contains the U-Boot version string as printed
5666 with the "version" command. This variable is
5667 readonly (see CONFIG_VERSION_VARIABLE).
5670 Please note that changes to some configuration parameters may take
5671 only effect after the next boot (yes, that's just like Windoze :-).
5674 Callback functions for environment variables:
5675 ---------------------------------------------
5677 For some environment variables, the behavior of u-boot needs to change
5678 when their values are changed. This functionality allows functions to
5679 be associated with arbitrary variables. On creation, overwrite, or
5680 deletion, the callback will provide the opportunity for some side
5681 effect to happen or for the change to be rejected.
5683 The callbacks are named and associated with a function using the
5684 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5686 These callbacks are associated with variables in one of two ways. The
5687 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5688 in the board configuration to a string that defines a list of
5689 associations. The list must be in the following format:
5691 entry = variable_name[:callback_name]
5694 If the callback name is not specified, then the callback is deleted.
5695 Spaces are also allowed anywhere in the list.
5697 Callbacks can also be associated by defining the ".callbacks" variable
5698 with the same list format above. Any association in ".callbacks" will
5699 override any association in the static list. You can define
5700 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5701 ".callbacks" environment variable in the default or embedded environment.
5703 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5704 regular expression. This allows multiple variables to be connected to
5705 the same callback without explicitly listing them all out.
5708 Command Line Parsing:
5709 =====================
5711 There are two different command line parsers available with U-Boot:
5712 the old "simple" one, and the much more powerful "hush" shell:
5714 Old, simple command line parser:
5715 --------------------------------
5717 - supports environment variables (through setenv / saveenv commands)
5718 - several commands on one line, separated by ';'
5719 - variable substitution using "... ${name} ..." syntax
5720 - special characters ('$', ';') can be escaped by prefixing with '\',
5722 setenv bootcmd bootm \${address}
5723 - You can also escape text by enclosing in single apostrophes, for example:
5724 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5729 - similar to Bourne shell, with control structures like
5730 if...then...else...fi, for...do...done; while...do...done,
5731 until...do...done, ...
5732 - supports environment ("global") variables (through setenv / saveenv
5733 commands) and local shell variables (through standard shell syntax
5734 "name=value"); only environment variables can be used with "run"
5740 (1) If a command line (or an environment variable executed by a "run"
5741 command) contains several commands separated by semicolon, and
5742 one of these commands fails, then the remaining commands will be
5745 (2) If you execute several variables with one call to run (i. e.
5746 calling run with a list of variables as arguments), any failing
5747 command will cause "run" to terminate, i. e. the remaining
5748 variables are not executed.
5750 Note for Redundant Ethernet Interfaces:
5751 =======================================
5753 Some boards come with redundant Ethernet interfaces; U-Boot supports
5754 such configurations and is capable of automatic selection of a
5755 "working" interface when needed. MAC assignment works as follows:
5757 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5758 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5759 "eth1addr" (=>eth1), "eth2addr", ...
5761 If the network interface stores some valid MAC address (for instance
5762 in SROM), this is used as default address if there is NO correspon-
5763 ding setting in the environment; if the corresponding environment
5764 variable is set, this overrides the settings in the card; that means:
5766 o If the SROM has a valid MAC address, and there is no address in the
5767 environment, the SROM's address is used.
5769 o If there is no valid address in the SROM, and a definition in the
5770 environment exists, then the value from the environment variable is
5773 o If both the SROM and the environment contain a MAC address, and
5774 both addresses are the same, this MAC address is used.
5776 o If both the SROM and the environment contain a MAC address, and the
5777 addresses differ, the value from the environment is used and a
5780 o If neither SROM nor the environment contain a MAC address, an error
5781 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5782 a random, locally-assigned MAC is used.
5784 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5785 will be programmed into hardware as part of the initialization process. This
5786 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5787 The naming convention is as follows:
5788 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5793 U-Boot is capable of booting (and performing other auxiliary operations on)
5794 images in two formats:
5796 New uImage format (FIT)
5797 -----------------------
5799 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5800 to Flattened Device Tree). It allows the use of images with multiple
5801 components (several kernels, ramdisks, etc.), with contents protected by
5802 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5808 Old image format is based on binary files which can be basically anything,
5809 preceded by a special header; see the definitions in include/image.h for
5810 details; basically, the header defines the following image properties:
5812 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5813 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5814 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5815 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5817 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5818 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5819 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5820 * Compression Type (uncompressed, gzip, bzip2)
5826 The header is marked by a special Magic Number, and both the header
5827 and the data portions of the image are secured against corruption by
5834 Although U-Boot should support any OS or standalone application
5835 easily, the main focus has always been on Linux during the design of
5838 U-Boot includes many features that so far have been part of some
5839 special "boot loader" code within the Linux kernel. Also, any
5840 "initrd" images to be used are no longer part of one big Linux image;
5841 instead, kernel and "initrd" are separate images. This implementation
5842 serves several purposes:
5844 - the same features can be used for other OS or standalone
5845 applications (for instance: using compressed images to reduce the
5846 Flash memory footprint)
5848 - it becomes much easier to port new Linux kernel versions because
5849 lots of low-level, hardware dependent stuff are done by U-Boot
5851 - the same Linux kernel image can now be used with different "initrd"
5852 images; of course this also means that different kernel images can
5853 be run with the same "initrd". This makes testing easier (you don't
5854 have to build a new "zImage.initrd" Linux image when you just
5855 change a file in your "initrd"). Also, a field-upgrade of the
5856 software is easier now.
5862 Porting Linux to U-Boot based systems:
5863 ---------------------------------------
5865 U-Boot cannot save you from doing all the necessary modifications to
5866 configure the Linux device drivers for use with your target hardware
5867 (no, we don't intend to provide a full virtual machine interface to
5870 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5872 Just make sure your machine specific header file (for instance
5873 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5874 Information structure as we define in include/asm-<arch>/u-boot.h,
5875 and make sure that your definition of IMAP_ADDR uses the same value
5876 as your U-Boot configuration in CONFIG_SYS_IMMR.
5878 Note that U-Boot now has a driver model, a unified model for drivers.
5879 If you are adding a new driver, plumb it into driver model. If there
5880 is no uclass available, you are encouraged to create one. See
5884 Configuring the Linux kernel:
5885 -----------------------------
5887 No specific requirements for U-Boot. Make sure you have some root
5888 device (initial ramdisk, NFS) for your target system.
5891 Building a Linux Image:
5892 -----------------------
5894 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5895 not used. If you use recent kernel source, a new build target
5896 "uImage" will exist which automatically builds an image usable by
5897 U-Boot. Most older kernels also have support for a "pImage" target,
5898 which was introduced for our predecessor project PPCBoot and uses a
5899 100% compatible format.
5903 make TQM850L_defconfig
5908 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5909 encapsulate a compressed Linux kernel image with header information,
5910 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5912 * build a standard "vmlinux" kernel image (in ELF binary format):
5914 * convert the kernel into a raw binary image:
5916 ${CROSS_COMPILE}-objcopy -O binary \
5917 -R .note -R .comment \
5918 -S vmlinux linux.bin
5920 * compress the binary image:
5924 * package compressed binary image for U-Boot:
5926 mkimage -A ppc -O linux -T kernel -C gzip \
5927 -a 0 -e 0 -n "Linux Kernel Image" \
5928 -d linux.bin.gz uImage
5931 The "mkimage" tool can also be used to create ramdisk images for use
5932 with U-Boot, either separated from the Linux kernel image, or
5933 combined into one file. "mkimage" encapsulates the images with a 64
5934 byte header containing information about target architecture,
5935 operating system, image type, compression method, entry points, time
5936 stamp, CRC32 checksums, etc.
5938 "mkimage" can be called in two ways: to verify existing images and
5939 print the header information, or to build new images.
5941 In the first form (with "-l" option) mkimage lists the information
5942 contained in the header of an existing U-Boot image; this includes
5943 checksum verification:
5945 tools/mkimage -l image
5946 -l ==> list image header information
5948 The second form (with "-d" option) is used to build a U-Boot image
5949 from a "data file" which is used as image payload:
5951 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5952 -n name -d data_file image
5953 -A ==> set architecture to 'arch'
5954 -O ==> set operating system to 'os'
5955 -T ==> set image type to 'type'
5956 -C ==> set compression type 'comp'
5957 -a ==> set load address to 'addr' (hex)
5958 -e ==> set entry point to 'ep' (hex)
5959 -n ==> set image name to 'name'
5960 -d ==> use image data from 'datafile'
5962 Right now, all Linux kernels for PowerPC systems use the same load
5963 address (0x00000000), but the entry point address depends on the
5966 - 2.2.x kernels have the entry point at 0x0000000C,
5967 - 2.3.x and later kernels have the entry point at 0x00000000.
5969 So a typical call to build a U-Boot image would read:
5971 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5972 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5973 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5974 > examples/uImage.TQM850L
5975 Image Name: 2.4.4 kernel for TQM850L
5976 Created: Wed Jul 19 02:34:59 2000
5977 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5978 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5979 Load Address: 0x00000000
5980 Entry Point: 0x00000000
5982 To verify the contents of the image (or check for corruption):
5984 -> tools/mkimage -l examples/uImage.TQM850L
5985 Image Name: 2.4.4 kernel for TQM850L
5986 Created: Wed Jul 19 02:34:59 2000
5987 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5988 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5989 Load Address: 0x00000000
5990 Entry Point: 0x00000000
5992 NOTE: for embedded systems where boot time is critical you can trade
5993 speed for memory and install an UNCOMPRESSED image instead: this
5994 needs more space in Flash, but boots much faster since it does not
5995 need to be uncompressed:
5997 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5998 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5999 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
6000 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
6001 > examples/uImage.TQM850L-uncompressed
6002 Image Name: 2.4.4 kernel for TQM850L
6003 Created: Wed Jul 19 02:34:59 2000
6004 Image Type: PowerPC Linux Kernel Image (uncompressed)
6005 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
6006 Load Address: 0x00000000
6007 Entry Point: 0x00000000
6010 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
6011 when your kernel is intended to use an initial ramdisk:
6013 -> tools/mkimage -n 'Simple Ramdisk Image' \
6014 > -A ppc -O linux -T ramdisk -C gzip \
6015 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
6016 Image Name: Simple Ramdisk Image
6017 Created: Wed Jan 12 14:01:50 2000
6018 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6019 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6020 Load Address: 0x00000000
6021 Entry Point: 0x00000000
6023 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6024 option performs the converse operation of the mkimage's second form (the "-d"
6025 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6028 tools/dumpimage -i image -T type -p position data_file
6029 -i ==> extract from the 'image' a specific 'data_file'
6030 -T ==> set image type to 'type'
6031 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6034 Installing a Linux Image:
6035 -------------------------
6037 To downloading a U-Boot image over the serial (console) interface,
6038 you must convert the image to S-Record format:
6040 objcopy -I binary -O srec examples/image examples/image.srec
6042 The 'objcopy' does not understand the information in the U-Boot
6043 image header, so the resulting S-Record file will be relative to
6044 address 0x00000000. To load it to a given address, you need to
6045 specify the target address as 'offset' parameter with the 'loads'
6048 Example: install the image to address 0x40100000 (which on the
6049 TQM8xxL is in the first Flash bank):
6051 => erase 40100000 401FFFFF
6057 ## Ready for S-Record download ...
6058 ~>examples/image.srec
6059 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6061 15989 15990 15991 15992
6062 [file transfer complete]
6064 ## Start Addr = 0x00000000
6067 You can check the success of the download using the 'iminfo' command;
6068 this includes a checksum verification so you can be sure no data
6069 corruption happened:
6073 ## Checking Image at 40100000 ...
6074 Image Name: 2.2.13 for initrd on TQM850L
6075 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6076 Data Size: 335725 Bytes = 327 kB = 0 MB
6077 Load Address: 00000000
6078 Entry Point: 0000000c
6079 Verifying Checksum ... OK
6085 The "bootm" command is used to boot an application that is stored in
6086 memory (RAM or Flash). In case of a Linux kernel image, the contents
6087 of the "bootargs" environment variable is passed to the kernel as
6088 parameters. You can check and modify this variable using the
6089 "printenv" and "setenv" commands:
6092 => printenv bootargs
6093 bootargs=root=/dev/ram
6095 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6097 => printenv bootargs
6098 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6101 ## Booting Linux kernel at 40020000 ...
6102 Image Name: 2.2.13 for NFS on TQM850L
6103 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6104 Data Size: 381681 Bytes = 372 kB = 0 MB
6105 Load Address: 00000000
6106 Entry Point: 0000000c
6107 Verifying Checksum ... OK
6108 Uncompressing Kernel Image ... OK
6109 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
6110 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6111 time_init: decrementer frequency = 187500000/60
6112 Calibrating delay loop... 49.77 BogoMIPS
6113 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6116 If you want to boot a Linux kernel with initial RAM disk, you pass
6117 the memory addresses of both the kernel and the initrd image (PPBCOOT
6118 format!) to the "bootm" command:
6120 => imi 40100000 40200000
6122 ## Checking Image at 40100000 ...
6123 Image Name: 2.2.13 for initrd on TQM850L
6124 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6125 Data Size: 335725 Bytes = 327 kB = 0 MB
6126 Load Address: 00000000
6127 Entry Point: 0000000c
6128 Verifying Checksum ... OK
6130 ## Checking Image at 40200000 ...
6131 Image Name: Simple Ramdisk Image
6132 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6133 Data Size: 566530 Bytes = 553 kB = 0 MB
6134 Load Address: 00000000
6135 Entry Point: 00000000
6136 Verifying Checksum ... OK
6138 => bootm 40100000 40200000
6139 ## Booting Linux kernel at 40100000 ...
6140 Image Name: 2.2.13 for initrd on TQM850L
6141 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6142 Data Size: 335725 Bytes = 327 kB = 0 MB
6143 Load Address: 00000000
6144 Entry Point: 0000000c
6145 Verifying Checksum ... OK
6146 Uncompressing Kernel Image ... OK
6147 ## Loading RAMDisk Image at 40200000 ...
6148 Image Name: Simple Ramdisk Image
6149 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6150 Data Size: 566530 Bytes = 553 kB = 0 MB
6151 Load Address: 00000000
6152 Entry Point: 00000000
6153 Verifying Checksum ... OK
6154 Loading Ramdisk ... OK
6155 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
6156 Boot arguments: root=/dev/ram
6157 time_init: decrementer frequency = 187500000/60
6158 Calibrating delay loop... 49.77 BogoMIPS
6160 RAMDISK: Compressed image found at block 0
6161 VFS: Mounted root (ext2 filesystem).
6165 Boot Linux and pass a flat device tree:
6168 First, U-Boot must be compiled with the appropriate defines. See the section
6169 titled "Linux Kernel Interface" above for a more in depth explanation. The
6170 following is an example of how to start a kernel and pass an updated
6176 oft=oftrees/mpc8540ads.dtb
6177 => tftp $oftaddr $oft
6178 Speed: 1000, full duplex
6180 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6181 Filename 'oftrees/mpc8540ads.dtb'.
6182 Load address: 0x300000
6185 Bytes transferred = 4106 (100a hex)
6186 => tftp $loadaddr $bootfile
6187 Speed: 1000, full duplex
6189 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6191 Load address: 0x200000
6192 Loading:############
6194 Bytes transferred = 1029407 (fb51f hex)
6199 => bootm $loadaddr - $oftaddr
6200 ## Booting image at 00200000 ...
6201 Image Name: Linux-2.6.17-dirty
6202 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6203 Data Size: 1029343 Bytes = 1005.2 kB
6204 Load Address: 00000000
6205 Entry Point: 00000000
6206 Verifying Checksum ... OK
6207 Uncompressing Kernel Image ... OK
6208 Booting using flat device tree at 0x300000
6209 Using MPC85xx ADS machine description
6210 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6214 More About U-Boot Image Types:
6215 ------------------------------
6217 U-Boot supports the following image types:
6219 "Standalone Programs" are directly runnable in the environment
6220 provided by U-Boot; it is expected that (if they behave
6221 well) you can continue to work in U-Boot after return from
6222 the Standalone Program.
6223 "OS Kernel Images" are usually images of some Embedded OS which
6224 will take over control completely. Usually these programs
6225 will install their own set of exception handlers, device
6226 drivers, set up the MMU, etc. - this means, that you cannot
6227 expect to re-enter U-Boot except by resetting the CPU.
6228 "RAMDisk Images" are more or less just data blocks, and their
6229 parameters (address, size) are passed to an OS kernel that is
6231 "Multi-File Images" contain several images, typically an OS
6232 (Linux) kernel image and one or more data images like
6233 RAMDisks. This construct is useful for instance when you want
6234 to boot over the network using BOOTP etc., where the boot
6235 server provides just a single image file, but you want to get
6236 for instance an OS kernel and a RAMDisk image.
6238 "Multi-File Images" start with a list of image sizes, each
6239 image size (in bytes) specified by an "uint32_t" in network
6240 byte order. This list is terminated by an "(uint32_t)0".
6241 Immediately after the terminating 0 follow the images, one by
6242 one, all aligned on "uint32_t" boundaries (size rounded up to
6243 a multiple of 4 bytes).
6245 "Firmware Images" are binary images containing firmware (like
6246 U-Boot or FPGA images) which usually will be programmed to
6249 "Script files" are command sequences that will be executed by
6250 U-Boot's command interpreter; this feature is especially
6251 useful when you configure U-Boot to use a real shell (hush)
6252 as command interpreter.
6254 Booting the Linux zImage:
6255 -------------------------
6257 On some platforms, it's possible to boot Linux zImage. This is done
6258 using the "bootz" command. The syntax of "bootz" command is the same
6259 as the syntax of "bootm" command.
6261 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6262 kernel with raw initrd images. The syntax is slightly different, the
6263 address of the initrd must be augmented by it's size, in the following
6264 format: "<initrd addres>:<initrd size>".
6270 One of the features of U-Boot is that you can dynamically load and
6271 run "standalone" applications, which can use some resources of
6272 U-Boot like console I/O functions or interrupt services.
6274 Two simple examples are included with the sources:
6279 'examples/hello_world.c' contains a small "Hello World" Demo
6280 application; it is automatically compiled when you build U-Boot.
6281 It's configured to run at address 0x00040004, so you can play with it
6285 ## Ready for S-Record download ...
6286 ~>examples/hello_world.srec
6287 1 2 3 4 5 6 7 8 9 10 11 ...
6288 [file transfer complete]
6290 ## Start Addr = 0x00040004
6292 => go 40004 Hello World! This is a test.
6293 ## Starting application at 0x00040004 ...
6304 Hit any key to exit ...
6306 ## Application terminated, rc = 0x0
6308 Another example, which demonstrates how to register a CPM interrupt
6309 handler with the U-Boot code, can be found in 'examples/timer.c'.
6310 Here, a CPM timer is set up to generate an interrupt every second.
6311 The interrupt service routine is trivial, just printing a '.'
6312 character, but this is just a demo program. The application can be
6313 controlled by the following keys:
6315 ? - print current values og the CPM Timer registers
6316 b - enable interrupts and start timer
6317 e - stop timer and disable interrupts
6318 q - quit application
6321 ## Ready for S-Record download ...
6322 ~>examples/timer.srec
6323 1 2 3 4 5 6 7 8 9 10 11 ...
6324 [file transfer complete]
6326 ## Start Addr = 0x00040004
6329 ## Starting application at 0x00040004 ...
6332 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6335 [q, b, e, ?] Set interval 1000000 us
6338 [q, b, e, ?] ........
6339 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6342 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6345 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6348 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6350 [q, b, e, ?] ...Stopping timer
6352 [q, b, e, ?] ## Application terminated, rc = 0x0
6358 Over time, many people have reported problems when trying to use the
6359 "minicom" terminal emulation program for serial download. I (wd)
6360 consider minicom to be broken, and recommend not to use it. Under
6361 Unix, I recommend to use C-Kermit for general purpose use (and
6362 especially for kermit binary protocol download ("loadb" command), and
6363 use "cu" for S-Record download ("loads" command). See
6364 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6365 for help with kermit.
6368 Nevertheless, if you absolutely want to use it try adding this
6369 configuration to your "File transfer protocols" section:
6371 Name Program Name U/D FullScr IO-Red. Multi
6372 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6373 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6379 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6380 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6382 Building requires a cross environment; it is known to work on
6383 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6384 need gmake since the Makefiles are not compatible with BSD make).
6385 Note that the cross-powerpc package does not install include files;
6386 attempting to build U-Boot will fail because <machine/ansi.h> is
6387 missing. This file has to be installed and patched manually:
6389 # cd /usr/pkg/cross/powerpc-netbsd/include
6391 # ln -s powerpc machine
6392 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6393 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6395 Native builds *don't* work due to incompatibilities between native
6396 and U-Boot include files.
6398 Booting assumes that (the first part of) the image booted is a
6399 stage-2 loader which in turn loads and then invokes the kernel
6400 proper. Loader sources will eventually appear in the NetBSD source
6401 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6402 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6405 Implementation Internals:
6406 =========================
6408 The following is not intended to be a complete description of every
6409 implementation detail. However, it should help to understand the
6410 inner workings of U-Boot and make it easier to port it to custom
6414 Initial Stack, Global Data:
6415 ---------------------------
6417 The implementation of U-Boot is complicated by the fact that U-Boot
6418 starts running out of ROM (flash memory), usually without access to
6419 system RAM (because the memory controller is not initialized yet).
6420 This means that we don't have writable Data or BSS segments, and BSS
6421 is not initialized as zero. To be able to get a C environment working
6422 at all, we have to allocate at least a minimal stack. Implementation
6423 options for this are defined and restricted by the CPU used: Some CPU
6424 models provide on-chip memory (like the IMMR area on MPC8xx and
6425 MPC826x processors), on others (parts of) the data cache can be
6426 locked as (mis-) used as memory, etc.
6428 Chris Hallinan posted a good summary of these issues to the
6429 U-Boot mailing list:
6431 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6432 From: "Chris Hallinan" <clh@net1plus.com>
6433 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6436 Correct me if I'm wrong, folks, but the way I understand it
6437 is this: Using DCACHE as initial RAM for Stack, etc, does not
6438 require any physical RAM backing up the cache. The cleverness
6439 is that the cache is being used as a temporary supply of
6440 necessary storage before the SDRAM controller is setup. It's
6441 beyond the scope of this list to explain the details, but you
6442 can see how this works by studying the cache architecture and
6443 operation in the architecture and processor-specific manuals.
6445 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6446 is another option for the system designer to use as an
6447 initial stack/RAM area prior to SDRAM being available. Either
6448 option should work for you. Using CS 4 should be fine if your
6449 board designers haven't used it for something that would
6450 cause you grief during the initial boot! It is frequently not
6453 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6454 with your processor/board/system design. The default value
6455 you will find in any recent u-boot distribution in
6456 walnut.h should work for you. I'd set it to a value larger
6457 than your SDRAM module. If you have a 64MB SDRAM module, set
6458 it above 400_0000. Just make sure your board has no resources
6459 that are supposed to respond to that address! That code in
6460 start.S has been around a while and should work as is when
6461 you get the config right.
6466 It is essential to remember this, since it has some impact on the C
6467 code for the initialization procedures:
6469 * Initialized global data (data segment) is read-only. Do not attempt
6472 * Do not use any uninitialized global data (or implicitly initialized
6473 as zero data - BSS segment) at all - this is undefined, initiali-
6474 zation is performed later (when relocating to RAM).
6476 * Stack space is very limited. Avoid big data buffers or things like
6479 Having only the stack as writable memory limits means we cannot use
6480 normal global data to share information between the code. But it
6481 turned out that the implementation of U-Boot can be greatly
6482 simplified by making a global data structure (gd_t) available to all
6483 functions. We could pass a pointer to this data as argument to _all_
6484 functions, but this would bloat the code. Instead we use a feature of
6485 the GCC compiler (Global Register Variables) to share the data: we
6486 place a pointer (gd) to the global data into a register which we
6487 reserve for this purpose.
6489 When choosing a register for such a purpose we are restricted by the
6490 relevant (E)ABI specifications for the current architecture, and by
6491 GCC's implementation.
6493 For PowerPC, the following registers have specific use:
6495 R2: reserved for system use
6496 R3-R4: parameter passing and return values
6497 R5-R10: parameter passing
6498 R13: small data area pointer
6502 (U-Boot also uses R12 as internal GOT pointer. r12
6503 is a volatile register so r12 needs to be reset when
6504 going back and forth between asm and C)
6506 ==> U-Boot will use R2 to hold a pointer to the global data
6508 Note: on PPC, we could use a static initializer (since the
6509 address of the global data structure is known at compile time),
6510 but it turned out that reserving a register results in somewhat
6511 smaller code - although the code savings are not that big (on
6512 average for all boards 752 bytes for the whole U-Boot image,
6513 624 text + 127 data).
6515 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6516 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6518 ==> U-Boot will use P3 to hold a pointer to the global data
6520 On ARM, the following registers are used:
6522 R0: function argument word/integer result
6523 R1-R3: function argument word
6524 R9: platform specific
6525 R10: stack limit (used only if stack checking is enabled)
6526 R11: argument (frame) pointer
6527 R12: temporary workspace
6530 R15: program counter
6532 ==> U-Boot will use R9 to hold a pointer to the global data
6534 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6536 On Nios II, the ABI is documented here:
6537 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6539 ==> U-Boot will use gp to hold a pointer to the global data
6541 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6542 to access small data sections, so gp is free.
6544 On NDS32, the following registers are used:
6546 R0-R1: argument/return
6548 R15: temporary register for assembler
6549 R16: trampoline register
6550 R28: frame pointer (FP)
6551 R29: global pointer (GP)
6552 R30: link register (LP)
6553 R31: stack pointer (SP)
6554 PC: program counter (PC)
6556 ==> U-Boot will use R10 to hold a pointer to the global data
6558 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6559 or current versions of GCC may "optimize" the code too much.
6564 U-Boot runs in system state and uses physical addresses, i.e. the
6565 MMU is not used either for address mapping nor for memory protection.
6567 The available memory is mapped to fixed addresses using the memory
6568 controller. In this process, a contiguous block is formed for each
6569 memory type (Flash, SDRAM, SRAM), even when it consists of several
6570 physical memory banks.
6572 U-Boot is installed in the first 128 kB of the first Flash bank (on
6573 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6574 booting and sizing and initializing DRAM, the code relocates itself
6575 to the upper end of DRAM. Immediately below the U-Boot code some
6576 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6577 configuration setting]. Below that, a structure with global Board
6578 Info data is placed, followed by the stack (growing downward).
6580 Additionally, some exception handler code is copied to the low 8 kB
6581 of DRAM (0x00000000 ... 0x00001FFF).
6583 So a typical memory configuration with 16 MB of DRAM could look like
6586 0x0000 0000 Exception Vector code
6589 0x0000 2000 Free for Application Use
6595 0x00FB FF20 Monitor Stack (Growing downward)
6596 0x00FB FFAC Board Info Data and permanent copy of global data
6597 0x00FC 0000 Malloc Arena
6600 0x00FE 0000 RAM Copy of Monitor Code
6601 ... eventually: LCD or video framebuffer
6602 ... eventually: pRAM (Protected RAM - unchanged by reset)
6603 0x00FF FFFF [End of RAM]
6606 System Initialization:
6607 ----------------------
6609 In the reset configuration, U-Boot starts at the reset entry point
6610 (on most PowerPC systems at address 0x00000100). Because of the reset
6611 configuration for CS0# this is a mirror of the on board Flash memory.
6612 To be able to re-map memory U-Boot then jumps to its link address.
6613 To be able to implement the initialization code in C, a (small!)
6614 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6615 which provide such a feature like MPC8xx or MPC8260), or in a locked
6616 part of the data cache. After that, U-Boot initializes the CPU core,
6617 the caches and the SIU.
6619 Next, all (potentially) available memory banks are mapped using a
6620 preliminary mapping. For example, we put them on 512 MB boundaries
6621 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6622 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6623 programmed for SDRAM access. Using the temporary configuration, a
6624 simple memory test is run that determines the size of the SDRAM
6627 When there is more than one SDRAM bank, and the banks are of
6628 different size, the largest is mapped first. For equal size, the first
6629 bank (CS2#) is mapped first. The first mapping is always for address
6630 0x00000000, with any additional banks following immediately to create
6631 contiguous memory starting from 0.
6633 Then, the monitor installs itself at the upper end of the SDRAM area
6634 and allocates memory for use by malloc() and for the global Board
6635 Info data; also, the exception vector code is copied to the low RAM
6636 pages, and the final stack is set up.
6638 Only after this relocation will you have a "normal" C environment;
6639 until that you are restricted in several ways, mostly because you are
6640 running from ROM, and because the code will have to be relocated to a
6644 U-Boot Porting Guide:
6645 ----------------------
6647 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6651 int main(int argc, char *argv[])
6653 sighandler_t no_more_time;
6655 signal(SIGALRM, no_more_time);
6656 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6658 if (available_money > available_manpower) {
6659 Pay consultant to port U-Boot;
6663 Download latest U-Boot source;
6665 Subscribe to u-boot mailing list;
6668 email("Hi, I am new to U-Boot, how do I get started?");
6671 Read the README file in the top level directory;
6672 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6673 Read applicable doc/*.README;
6674 Read the source, Luke;
6675 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6678 if (available_money > toLocalCurrency ($2500))
6681 Add a lot of aggravation and time;
6683 if (a similar board exists) { /* hopefully... */
6684 cp -a board/<similar> board/<myboard>
6685 cp include/configs/<similar>.h include/configs/<myboard>.h
6687 Create your own board support subdirectory;
6688 Create your own board include/configs/<myboard>.h file;
6690 Edit new board/<myboard> files
6691 Edit new include/configs/<myboard>.h
6696 Add / modify source code;
6700 email("Hi, I am having problems...");
6702 Send patch file to the U-Boot email list;
6703 if (reasonable critiques)
6704 Incorporate improvements from email list code review;
6706 Defend code as written;
6712 void no_more_time (int sig)
6721 All contributions to U-Boot should conform to the Linux kernel
6722 coding style; see the file "Documentation/CodingStyle" and the script
6723 "scripts/Lindent" in your Linux kernel source directory.
6725 Source files originating from a different project (for example the
6726 MTD subsystem) are generally exempt from these guidelines and are not
6727 reformatted to ease subsequent migration to newer versions of those
6730 Please note that U-Boot is implemented in C (and to some small parts in
6731 Assembler); no C++ is used, so please do not use C++ style comments (//)
6734 Please also stick to the following formatting rules:
6735 - remove any trailing white space
6736 - use TAB characters for indentation and vertical alignment, not spaces
6737 - make sure NOT to use DOS '\r\n' line feeds
6738 - do not add more than 2 consecutive empty lines to source files
6739 - do not add trailing empty lines to source files
6741 Submissions which do not conform to the standards may be returned
6742 with a request to reformat the changes.
6748 Since the number of patches for U-Boot is growing, we need to
6749 establish some rules. Submissions which do not conform to these rules
6750 may be rejected, even when they contain important and valuable stuff.
6752 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6754 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6755 see http://lists.denx.de/mailman/listinfo/u-boot
6757 When you send a patch, please include the following information with
6760 * For bug fixes: a description of the bug and how your patch fixes
6761 this bug. Please try to include a way of demonstrating that the
6762 patch actually fixes something.
6764 * For new features: a description of the feature and your
6767 * A CHANGELOG entry as plaintext (separate from the patch)
6769 * For major contributions, your entry to the CREDITS file
6771 * When you add support for a new board, don't forget to add a
6772 maintainer e-mail address to the boards.cfg file, too.
6774 * If your patch adds new configuration options, don't forget to
6775 document these in the README file.
6777 * The patch itself. If you are using git (which is *strongly*
6778 recommended) you can easily generate the patch using the
6779 "git format-patch". If you then use "git send-email" to send it to
6780 the U-Boot mailing list, you will avoid most of the common problems
6781 with some other mail clients.
6783 If you cannot use git, use "diff -purN OLD NEW". If your version of
6784 diff does not support these options, then get the latest version of
6787 The current directory when running this command shall be the parent
6788 directory of the U-Boot source tree (i. e. please make sure that
6789 your patch includes sufficient directory information for the
6792 We prefer patches as plain text. MIME attachments are discouraged,
6793 and compressed attachments must not be used.
6795 * If one logical set of modifications affects or creates several
6796 files, all these changes shall be submitted in a SINGLE patch file.
6798 * Changesets that contain different, unrelated modifications shall be
6799 submitted as SEPARATE patches, one patch per changeset.
6804 * Before sending the patch, run the MAKEALL script on your patched
6805 source tree and make sure that no errors or warnings are reported
6806 for any of the boards.
6808 * Keep your modifications to the necessary minimum: A patch
6809 containing several unrelated changes or arbitrary reformats will be
6810 returned with a request to re-formatting / split it.
6812 * If you modify existing code, make sure that your new code does not
6813 add to the memory footprint of the code ;-) Small is beautiful!
6814 When adding new features, these should compile conditionally only
6815 (using #ifdef), and the resulting code with the new feature
6816 disabled must not need more memory than the old code without your
6819 * Remember that there is a size limit of 100 kB per message on the
6820 u-boot mailing list. Bigger patches will be moderated. If they are
6821 reasonable and not too big, they will be acknowledged. But patches
6822 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob