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
707 CONFIG_TEGRA_SUPPORT_NON_SECURE
709 Support executing U-Boot in non-secure (NS) mode. Certain
710 impossible actions will be skipped if the CPU is in NS mode,
711 such as ARM architectural timer initialization.
714 Driver model is a new framework for devices in U-Boot
715 introduced in early 2014. U-Boot is being progressively
716 moved over to this. It offers a consistent device structure,
717 supports grouping devices into classes and has built-in
718 handling of platform data and device tree.
720 To enable transition to driver model in a relatively
721 painful fashion, each subsystem can be independently
722 switched between the legacy/ad-hoc approach and the new
723 driver model using the options below. Also, many uclass
724 interfaces include compatibility features which may be
725 removed once the conversion of that subsystem is complete.
726 As a result, the API provided by the subsystem may in fact
727 not change with driver model.
729 See doc/driver-model/README.txt for more information.
733 Enable driver model. This brings in the core support,
734 including scanning of platform data on start-up. If
735 CONFIG_OF_CONTROL is enabled, the device tree will be
736 scanned also when available.
740 Enable driver model test commands. These allow you to print
741 out the driver model tree and the uclasses.
745 Enable some demo devices and the 'demo' command. These are
746 really only useful for playing around while trying to
747 understand driver model in sandbox.
751 Enable driver model in SPL. You will need to provide a
752 suitable malloc() implementation. If you are not using the
753 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
754 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
755 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
756 In most cases driver model will only allocate a few uclasses
757 and devices in SPL, so 1KB should be enable. See
758 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
763 Enable driver model for serial. This replaces
764 drivers/serial/serial.c with the serial uclass, which
765 implements serial_putc() etc. The uclass interface is
766 defined in include/serial.h.
770 Enable driver model for GPIO access. The standard GPIO
771 interface (gpio_get_value(), etc.) is then implemented by
772 the GPIO uclass. Drivers provide methods to query the
773 particular GPIOs that they provide. The uclass interface
774 is defined in include/asm-generic/gpio.h.
778 Enable driver model for SPI. The SPI slave interface
779 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
780 the SPI uclass. Drivers provide methods to access the SPI
781 buses that they control. The uclass interface is defined in
782 include/spi.h. The existing spi_slave structure is attached
783 as 'parent data' to every slave on each bus. Slaves
784 typically use driver-private data instead of extending the
789 Enable driver model for SPI flash. This SPI flash interface
790 (spi_flash_probe(), spi_flash_write(), etc.) is then
791 implemented by the SPI flash uclass. There is one standard
792 SPI flash driver which knows how to probe most chips
793 supported by U-Boot. The uclass interface is defined in
794 include/spi_flash.h, but is currently fully compatible
795 with the old interface to avoid confusion and duplication
796 during the transition parent. SPI and SPI flash must be
797 enabled together (it is not possible to use driver model
798 for one and not the other).
802 Enable driver model for the Chrome OS EC interface. This
803 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
804 but otherwise makes few changes. Since cros_ec also supports
805 I2C and LPC (which don't support driver model yet), a full
806 conversion is not yet possible.
809 ** Code size options: The following options are enabled by
810 default except in SPL. Enable them explicitly to get these
815 Enable the dm_warn() function. This can use up quite a bit
816 of space for its strings.
820 Enable registering a serial device with the stdio library.
822 CONFIG_DM_DEVICE_REMOVE
824 Enable removing of devices.
826 - Linux Kernel Interface:
829 U-Boot stores all clock information in Hz
830 internally. For binary compatibility with older Linux
831 kernels (which expect the clocks passed in the
832 bd_info data to be in MHz) the environment variable
833 "clocks_in_mhz" can be defined so that U-Boot
834 converts clock data to MHZ before passing it to the
836 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
837 "clocks_in_mhz=1" is automatically included in the
840 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
842 When transferring memsize parameter to Linux, some versions
843 expect it to be in bytes, others in MB.
844 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
848 New kernel versions are expecting firmware settings to be
849 passed using flattened device trees (based on open firmware
853 * New libfdt-based support
854 * Adds the "fdt" command
855 * The bootm command automatically updates the fdt
857 OF_CPU - The proper name of the cpus node (only required for
858 MPC512X and MPC5xxx based boards).
859 OF_SOC - The proper name of the soc node (only required for
860 MPC512X and MPC5xxx based boards).
861 OF_TBCLK - The timebase frequency.
862 OF_STDOUT_PATH - The path to the console device
864 boards with QUICC Engines require OF_QE to set UCC MAC
867 CONFIG_OF_BOARD_SETUP
869 Board code has addition modification that it wants to make
870 to the flat device tree before handing it off to the kernel
872 CONFIG_OF_SYSTEM_SETUP
874 Other code has addition modification that it wants to make
875 to the flat device tree before handing it off to the kernel.
876 This causes ft_system_setup() to be called before booting
881 This define fills in the correct boot CPU in the boot
882 param header, the default value is zero if undefined.
886 U-Boot can detect if an IDE device is present or not.
887 If not, and this new config option is activated, U-Boot
888 removes the ATA node from the DTS before booting Linux,
889 so the Linux IDE driver does not probe the device and
890 crash. This is needed for buggy hardware (uc101) where
891 no pull down resistor is connected to the signal IDE5V_DD7.
893 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
895 This setting is mandatory for all boards that have only one
896 machine type and must be used to specify the machine type
897 number as it appears in the ARM machine registry
898 (see http://www.arm.linux.org.uk/developer/machines/).
899 Only boards that have multiple machine types supported
900 in a single configuration file and the machine type is
901 runtime discoverable, do not have to use this setting.
903 - vxWorks boot parameters:
905 bootvx constructs a valid bootline using the following
906 environments variables: bootfile, ipaddr, serverip, hostname.
907 It loads the vxWorks image pointed bootfile.
909 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
910 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
911 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
912 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
914 CONFIG_SYS_VXWORKS_ADD_PARAMS
916 Add it at the end of the bootline. E.g "u=username pw=secret"
918 Note: If a "bootargs" environment is defined, it will overwride
919 the defaults discussed just above.
921 - Cache Configuration:
922 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
923 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
924 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
926 - Cache Configuration for ARM:
927 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
929 CONFIG_SYS_PL310_BASE - Physical base address of PL310
930 controller register space
935 Define this if you want support for Amba PrimeCell PL010 UARTs.
939 Define this if you want support for Amba PrimeCell PL011 UARTs.
943 If you have Amba PrimeCell PL011 UARTs, set this variable to
944 the clock speed of the UARTs.
948 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
949 define this to a list of base addresses for each (supported)
950 port. See e.g. include/configs/versatile.h
952 CONFIG_PL011_SERIAL_RLCR
954 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
955 have separate receive and transmit line control registers. Set
956 this variable to initialize the extra register.
958 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
960 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
961 boot loader that has already initialized the UART. Define this
962 variable to flush the UART at init time.
964 CONFIG_SERIAL_HW_FLOW_CONTROL
966 Define this variable to enable hw flow control in serial driver.
967 Current user of this option is drivers/serial/nsl16550.c driver
970 Depending on board, define exactly one serial port
971 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
972 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
973 console by defining CONFIG_8xx_CONS_NONE
975 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
976 port routines must be defined elsewhere
977 (i.e. serial_init(), serial_getc(), ...)
980 Enables console device for a color framebuffer. Needs following
981 defines (cf. smiLynxEM, i8042)
982 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
984 VIDEO_HW_RECTFILL graphic chip supports
987 VIDEO_HW_BITBLT graphic chip supports
988 bit-blit (cf. smiLynxEM)
989 VIDEO_VISIBLE_COLS visible pixel columns
991 VIDEO_VISIBLE_ROWS visible pixel rows
992 VIDEO_PIXEL_SIZE bytes per pixel
993 VIDEO_DATA_FORMAT graphic data format
994 (0-5, cf. cfb_console.c)
995 VIDEO_FB_ADRS framebuffer address
996 VIDEO_KBD_INIT_FCT keyboard int fct
997 (i.e. i8042_kbd_init())
998 VIDEO_TSTC_FCT test char fct
1000 VIDEO_GETC_FCT get char fct
1002 CONFIG_CONSOLE_CURSOR cursor drawing on/off
1003 (requires blink timer
1005 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1006 CONFIG_CONSOLE_TIME display time/date info in
1008 (requires CONFIG_CMD_DATE)
1009 CONFIG_VIDEO_LOGO display Linux logo in
1011 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1012 linux_logo.h for logo.
1013 Requires CONFIG_VIDEO_LOGO
1014 CONFIG_CONSOLE_EXTRA_INFO
1015 additional board info beside
1018 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1019 a limited number of ANSI escape sequences (cursor control,
1020 erase functions and limited graphics rendition control).
1022 When CONFIG_CFB_CONSOLE is defined, video console is
1023 default i/o. Serial console can be forced with
1024 environment 'console=serial'.
1026 When CONFIG_SILENT_CONSOLE is defined, all console
1027 messages (by U-Boot and Linux!) can be silenced with
1028 the "silent" environment variable. See
1029 doc/README.silent for more information.
1031 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1033 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1037 CONFIG_BAUDRATE - in bps
1038 Select one of the baudrates listed in
1039 CONFIG_SYS_BAUDRATE_TABLE, see below.
1040 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1042 - Console Rx buffer length
1043 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1044 the maximum receive buffer length for the SMC.
1045 This option is actual only for 82xx and 8xx possible.
1046 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1047 must be defined, to setup the maximum idle timeout for
1050 - Pre-Console Buffer:
1051 Prior to the console being initialised (i.e. serial UART
1052 initialised etc) all console output is silently discarded.
1053 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1054 buffer any console messages prior to the console being
1055 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1056 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1057 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1058 bytes are output before the console is initialised, the
1059 earlier bytes are discarded.
1061 'Sane' compilers will generate smaller code if
1062 CONFIG_PRE_CON_BUF_SZ is a power of 2
1064 - Safe printf() functions
1065 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1066 the printf() functions. These are defined in
1067 include/vsprintf.h and include snprintf(), vsnprintf() and
1068 so on. Code size increase is approximately 300-500 bytes.
1069 If this option is not given then these functions will
1070 silently discard their buffer size argument - this means
1071 you are not getting any overflow checking in this case.
1073 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1074 Delay before automatically booting the default image;
1075 set to -1 to disable autoboot.
1076 set to -2 to autoboot with no delay and not check for abort
1077 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1079 See doc/README.autoboot for these options that
1080 work with CONFIG_BOOTDELAY. None are required.
1081 CONFIG_BOOT_RETRY_TIME
1082 CONFIG_BOOT_RETRY_MIN
1083 CONFIG_AUTOBOOT_KEYED
1084 CONFIG_AUTOBOOT_PROMPT
1085 CONFIG_AUTOBOOT_DELAY_STR
1086 CONFIG_AUTOBOOT_STOP_STR
1087 CONFIG_AUTOBOOT_DELAY_STR2
1088 CONFIG_AUTOBOOT_STOP_STR2
1089 CONFIG_ZERO_BOOTDELAY_CHECK
1090 CONFIG_RESET_TO_RETRY
1094 Only needed when CONFIG_BOOTDELAY is enabled;
1095 define a command string that is automatically executed
1096 when no character is read on the console interface
1097 within "Boot Delay" after reset.
1100 This can be used to pass arguments to the bootm
1101 command. The value of CONFIG_BOOTARGS goes into the
1102 environment value "bootargs".
1104 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1105 The value of these goes into the environment as
1106 "ramboot" and "nfsboot" respectively, and can be used
1107 as a convenience, when switching between booting from
1111 CONFIG_BOOTCOUNT_LIMIT
1112 Implements a mechanism for detecting a repeating reboot
1114 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1116 CONFIG_BOOTCOUNT_ENV
1117 If no softreset save registers are found on the hardware
1118 "bootcount" is stored in the environment. To prevent a
1119 saveenv on all reboots, the environment variable
1120 "upgrade_available" is used. If "upgrade_available" is
1121 0, "bootcount" is always 0, if "upgrade_available" is
1122 1 "bootcount" is incremented in the environment.
1123 So the Userspace Applikation must set the "upgrade_available"
1124 and "bootcount" variable to 0, if a boot was successfully.
1126 - Pre-Boot Commands:
1129 When this option is #defined, the existence of the
1130 environment variable "preboot" will be checked
1131 immediately before starting the CONFIG_BOOTDELAY
1132 countdown and/or running the auto-boot command resp.
1133 entering interactive mode.
1135 This feature is especially useful when "preboot" is
1136 automatically generated or modified. For an example
1137 see the LWMON board specific code: here "preboot" is
1138 modified when the user holds down a certain
1139 combination of keys on the (special) keyboard when
1142 - Serial Download Echo Mode:
1144 If defined to 1, all characters received during a
1145 serial download (using the "loads" command) are
1146 echoed back. This might be needed by some terminal
1147 emulations (like "cu"), but may as well just take
1148 time on others. This setting #define's the initial
1149 value of the "loads_echo" environment variable.
1151 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1152 CONFIG_KGDB_BAUDRATE
1153 Select one of the baudrates listed in
1154 CONFIG_SYS_BAUDRATE_TABLE, see below.
1156 - Monitor Functions:
1157 Monitor commands can be included or excluded
1158 from the build by using the #include files
1159 <config_cmd_all.h> and #undef'ing unwanted
1160 commands, or using <config_cmd_default.h>
1161 and augmenting with additional #define's
1162 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:
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:
1831 This enables the command "fastboot" which enables the Android
1832 fastboot mode for the platform's USB device. Fastboot is a USB
1833 protocol for downloading images, flashing and device control
1834 used on Android devices.
1835 See doc/README.android-fastboot for more information.
1837 CONFIG_ANDROID_BOOT_IMAGE
1838 This enables support for booting images which use the Android
1839 image format header.
1841 CONFIG_USB_FASTBOOT_BUF_ADDR
1842 The fastboot protocol requires a large memory buffer for
1843 downloads. Define this to the starting RAM address to use for
1846 CONFIG_USB_FASTBOOT_BUF_SIZE
1847 The fastboot protocol requires a large memory buffer for
1848 downloads. This buffer should be as large as possible for a
1849 platform. Define this to the size available RAM for fastboot.
1851 CONFIG_FASTBOOT_FLASH
1852 The fastboot protocol includes a "flash" command for writing
1853 the downloaded image to a non-volatile storage device. Define
1854 this to enable the "fastboot flash" command.
1856 CONFIG_FASTBOOT_FLASH_MMC_DEV
1857 The fastboot "flash" command requires additional information
1858 regarding the non-volatile storage device. Define this to
1859 the eMMC device that fastboot should use to store the image.
1861 CONFIG_FASTBOOT_GPT_NAME
1862 The fastboot "flash" command supports writing the downloaded
1863 image to the Protective MBR and the Primary GUID Partition
1864 Table. (Additionally, this downloaded image is post-processed
1865 to generate and write the Backup GUID Partition Table.)
1866 This occurs when the specified "partition name" on the
1867 "fastboot flash" command line matches this value.
1868 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1870 - Journaling Flash filesystem support:
1871 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1872 CONFIG_JFFS2_NAND_DEV
1873 Define these for a default partition on a NAND device
1875 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1876 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1877 Define these for a default partition on a NOR device
1879 CONFIG_SYS_JFFS_CUSTOM_PART
1880 Define this to create an own partition. You have to provide a
1881 function struct part_info* jffs2_part_info(int part_num)
1883 If you define only one JFFS2 partition you may also want to
1884 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1885 to disable the command chpart. This is the default when you
1886 have not defined a custom partition
1888 - FAT(File Allocation Table) filesystem write function support:
1891 Define this to enable support for saving memory data as a
1892 file in FAT formatted partition.
1894 This will also enable the command "fatwrite" enabling the
1895 user to write files to FAT.
1897 CBFS (Coreboot Filesystem) support
1900 Define this to enable support for reading from a Coreboot
1901 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1904 - FAT(File Allocation Table) filesystem cluster size:
1905 CONFIG_FS_FAT_MAX_CLUSTSIZE
1907 Define the max cluster size for fat operations else
1908 a default value of 65536 will be defined.
1913 Define this to enable standard (PC-Style) keyboard
1917 Standard PC keyboard driver with US (is default) and
1918 GERMAN key layout (switch via environment 'keymap=de') support.
1919 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1920 for cfb_console. Supports cursor blinking.
1923 Enables a Chrome OS keyboard using the CROS_EC interface.
1924 This uses CROS_EC to communicate with a second microcontroller
1925 which provides key scans on request.
1930 Define this to enable video support (for output to
1933 CONFIG_VIDEO_CT69000
1935 Enable Chips & Technologies 69000 Video chip
1937 CONFIG_VIDEO_SMI_LYNXEM
1938 Enable Silicon Motion SMI 712/710/810 Video chip. The
1939 video output is selected via environment 'videoout'
1940 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1943 For the CT69000 and SMI_LYNXEM drivers, videomode is
1944 selected via environment 'videomode'. Two different ways
1946 - "videomode=num" 'num' is a standard LiLo mode numbers.
1947 Following standard modes are supported (* is default):
1949 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1950 -------------+---------------------------------------------
1951 8 bits | 0x301* 0x303 0x305 0x161 0x307
1952 15 bits | 0x310 0x313 0x316 0x162 0x319
1953 16 bits | 0x311 0x314 0x317 0x163 0x31A
1954 24 bits | 0x312 0x315 0x318 ? 0x31B
1955 -------------+---------------------------------------------
1956 (i.e. setenv videomode 317; saveenv; reset;)
1958 - "videomode=bootargs" all the video parameters are parsed
1959 from the bootargs. (See drivers/video/videomodes.c)
1962 CONFIG_VIDEO_SED13806
1963 Enable Epson SED13806 driver. This driver supports 8bpp
1964 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1965 or CONFIG_VIDEO_SED13806_16BPP
1968 Enable the Freescale DIU video driver. Reference boards for
1969 SOCs that have a DIU should define this macro to enable DIU
1970 support, and should also define these other macros:
1976 CONFIG_VIDEO_SW_CURSOR
1977 CONFIG_VGA_AS_SINGLE_DEVICE
1979 CONFIG_VIDEO_BMP_LOGO
1981 The DIU driver will look for the 'video-mode' environment
1982 variable, and if defined, enable the DIU as a console during
1983 boot. See the documentation file README.video for a
1984 description of this variable.
1988 Enable the VGA video / BIOS for x86. The alternative if you
1989 are using coreboot is to use the coreboot frame buffer
1996 Define this to enable a custom keyboard support.
1997 This simply calls drv_keyboard_init() which must be
1998 defined in your board-specific files.
1999 The only board using this so far is RBC823.
2001 - LCD Support: CONFIG_LCD
2003 Define this to enable LCD support (for output to LCD
2004 display); also select one of the supported displays
2005 by defining one of these:
2009 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2011 CONFIG_NEC_NL6448AC33:
2013 NEC NL6448AC33-18. Active, color, single scan.
2015 CONFIG_NEC_NL6448BC20
2017 NEC NL6448BC20-08. 6.5", 640x480.
2018 Active, color, single scan.
2020 CONFIG_NEC_NL6448BC33_54
2022 NEC NL6448BC33-54. 10.4", 640x480.
2023 Active, color, single scan.
2027 Sharp 320x240. Active, color, single scan.
2028 It isn't 16x9, and I am not sure what it is.
2030 CONFIG_SHARP_LQ64D341
2032 Sharp LQ64D341 display, 640x480.
2033 Active, color, single scan.
2037 HLD1045 display, 640x480.
2038 Active, color, single scan.
2042 Optrex CBL50840-2 NF-FW 99 22 M5
2044 Hitachi LMG6912RPFC-00T
2048 320x240. Black & white.
2050 Normally display is black on white background; define
2051 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2053 CONFIG_LCD_ALIGNMENT
2055 Normally the LCD is page-aligned (typically 4KB). If this is
2056 defined then the LCD will be aligned to this value instead.
2057 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2058 here, since it is cheaper to change data cache settings on
2059 a per-section basis.
2061 CONFIG_CONSOLE_SCROLL_LINES
2063 When the console need to be scrolled, this is the number of
2064 lines to scroll by. It defaults to 1. Increasing this makes
2065 the console jump but can help speed up operation when scrolling
2070 Sometimes, for example if the display is mounted in portrait
2071 mode or even if it's mounted landscape but rotated by 180degree,
2072 we need to rotate our content of the display relative to the
2073 framebuffer, so that user can read the messages which are
2075 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2076 initialized with a given rotation from "vl_rot" out of
2077 "vidinfo_t" which is provided by the board specific code.
2078 The value for vl_rot is coded as following (matching to
2079 fbcon=rotate:<n> linux-kernel commandline):
2080 0 = no rotation respectively 0 degree
2081 1 = 90 degree rotation
2082 2 = 180 degree rotation
2083 3 = 270 degree rotation
2085 If CONFIG_LCD_ROTATION is not defined, the console will be
2086 initialized with 0degree rotation.
2090 Support drawing of RLE8-compressed bitmaps on the LCD.
2094 Enables an 'i2c edid' command which can read EDID
2095 information over I2C from an attached LCD display.
2097 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2099 If this option is set, the environment is checked for
2100 a variable "splashimage". If found, the usual display
2101 of logo, copyright and system information on the LCD
2102 is suppressed and the BMP image at the address
2103 specified in "splashimage" is loaded instead. The
2104 console is redirected to the "nulldev", too. This
2105 allows for a "silent" boot where a splash screen is
2106 loaded very quickly after power-on.
2108 CONFIG_SPLASHIMAGE_GUARD
2110 If this option is set, then U-Boot will prevent the environment
2111 variable "splashimage" from being set to a problematic address
2112 (see README.displaying-bmps).
2113 This option is useful for targets where, due to alignment
2114 restrictions, an improperly aligned BMP image will cause a data
2115 abort. If you think you will not have problems with unaligned
2116 accesses (for example because your toolchain prevents them)
2117 there is no need to set this option.
2119 CONFIG_SPLASH_SCREEN_ALIGN
2121 If this option is set the splash image can be freely positioned
2122 on the screen. Environment variable "splashpos" specifies the
2123 position as "x,y". If a positive number is given it is used as
2124 number of pixel from left/top. If a negative number is given it
2125 is used as number of pixel from right/bottom. You can also
2126 specify 'm' for centering the image.
2129 setenv splashpos m,m
2130 => image at center of screen
2132 setenv splashpos 30,20
2133 => image at x = 30 and y = 20
2135 setenv splashpos -10,m
2136 => vertically centered image
2137 at x = dspWidth - bmpWidth - 9
2139 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2141 If this option is set, additionally to standard BMP
2142 images, gzipped BMP images can be displayed via the
2143 splashscreen support or the bmp command.
2145 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2147 If this option is set, 8-bit RLE compressed BMP images
2148 can be displayed via the splashscreen support or the
2151 - Do compressing for memory range:
2154 If this option is set, it would use zlib deflate method
2155 to compress the specified memory at its best effort.
2157 - Compression support:
2160 Enabled by default to support gzip compressed images.
2164 If this option is set, support for bzip2 compressed
2165 images is included. If not, only uncompressed and gzip
2166 compressed images are supported.
2168 NOTE: the bzip2 algorithm requires a lot of RAM, so
2169 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2174 If this option is set, support for lzma compressed
2177 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2178 requires an amount of dynamic memory that is given by the
2181 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2183 Where lc and lp stand for, respectively, Literal context bits
2184 and Literal pos bits.
2186 This value is upper-bounded by 14MB in the worst case. Anyway,
2187 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2188 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2189 a very small buffer.
2191 Use the lzmainfo tool to determinate the lc and lp values and
2192 then calculate the amount of needed dynamic memory (ensuring
2193 the appropriate CONFIG_SYS_MALLOC_LEN value).
2197 If this option is set, support for LZO compressed images
2203 The address of PHY on MII bus.
2205 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2207 The clock frequency of the MII bus
2211 If this option is set, support for speed/duplex
2212 detection of gigabit PHY is included.
2214 CONFIG_PHY_RESET_DELAY
2216 Some PHY like Intel LXT971A need extra delay after
2217 reset before any MII register access is possible.
2218 For such PHY, set this option to the usec delay
2219 required. (minimum 300usec for LXT971A)
2221 CONFIG_PHY_CMD_DELAY (ppc4xx)
2223 Some PHY like Intel LXT971A need extra delay after
2224 command issued before MII status register can be read
2234 Define a default value for Ethernet address to use
2235 for the respective Ethernet interface, in case this
2236 is not determined automatically.
2241 Define a default value for the IP address to use for
2242 the default Ethernet interface, in case this is not
2243 determined through e.g. bootp.
2244 (Environment variable "ipaddr")
2246 - Server IP address:
2249 Defines a default value for the IP address of a TFTP
2250 server to contact when using the "tftboot" command.
2251 (Environment variable "serverip")
2253 CONFIG_KEEP_SERVERADDR
2255 Keeps the server's MAC address, in the env 'serveraddr'
2256 for passing to bootargs (like Linux's netconsole option)
2258 - Gateway IP address:
2261 Defines a default value for the IP address of the
2262 default router where packets to other networks are
2264 (Environment variable "gatewayip")
2269 Defines a default value for the subnet mask (or
2270 routing prefix) which is used to determine if an IP
2271 address belongs to the local subnet or needs to be
2272 forwarded through a router.
2273 (Environment variable "netmask")
2275 - Multicast TFTP Mode:
2278 Defines whether you want to support multicast TFTP as per
2279 rfc-2090; for example to work with atftp. Lets lots of targets
2280 tftp down the same boot image concurrently. Note: the Ethernet
2281 driver in use must provide a function: mcast() to join/leave a
2284 - BOOTP Recovery Mode:
2285 CONFIG_BOOTP_RANDOM_DELAY
2287 If you have many targets in a network that try to
2288 boot using BOOTP, you may want to avoid that all
2289 systems send out BOOTP requests at precisely the same
2290 moment (which would happen for instance at recovery
2291 from a power failure, when all systems will try to
2292 boot, thus flooding the BOOTP server. Defining
2293 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2294 inserted before sending out BOOTP requests. The
2295 following delays are inserted then:
2297 1st BOOTP request: delay 0 ... 1 sec
2298 2nd BOOTP request: delay 0 ... 2 sec
2299 3rd BOOTP request: delay 0 ... 4 sec
2301 BOOTP requests: delay 0 ... 8 sec
2303 CONFIG_BOOTP_ID_CACHE_SIZE
2305 BOOTP packets are uniquely identified using a 32-bit ID. The
2306 server will copy the ID from client requests to responses and
2307 U-Boot will use this to determine if it is the destination of
2308 an incoming response. Some servers will check that addresses
2309 aren't in use before handing them out (usually using an ARP
2310 ping) and therefore take up to a few hundred milliseconds to
2311 respond. Network congestion may also influence the time it
2312 takes for a response to make it back to the client. If that
2313 time is too long, U-Boot will retransmit requests. In order
2314 to allow earlier responses to still be accepted after these
2315 retransmissions, U-Boot's BOOTP client keeps a small cache of
2316 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2317 cache. The default is to keep IDs for up to four outstanding
2318 requests. Increasing this will allow U-Boot to accept offers
2319 from a BOOTP client in networks with unusually high latency.
2321 - BOOTP Random transaction ID:
2322 CONFIG_BOOTP_RANDOM_ID
2324 The standard algorithm to generate a DHCP/BOOTP transaction ID
2325 by using the MAC address and the current time stamp may not
2326 quite unlikely produce duplicate transaction IDs from different
2327 clients in the same network. This option creates a transaction
2328 ID using the rand() function. Provided that the RNG has been
2329 seeded well, this should guarantee unique transaction IDs
2332 - DHCP Advanced Options:
2333 You can fine tune the DHCP functionality by defining
2334 CONFIG_BOOTP_* symbols:
2336 CONFIG_BOOTP_SUBNETMASK
2337 CONFIG_BOOTP_GATEWAY
2338 CONFIG_BOOTP_HOSTNAME
2339 CONFIG_BOOTP_NISDOMAIN
2340 CONFIG_BOOTP_BOOTPATH
2341 CONFIG_BOOTP_BOOTFILESIZE
2344 CONFIG_BOOTP_SEND_HOSTNAME
2345 CONFIG_BOOTP_NTPSERVER
2346 CONFIG_BOOTP_TIMEOFFSET
2347 CONFIG_BOOTP_VENDOREX
2348 CONFIG_BOOTP_MAY_FAIL
2350 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2351 environment variable, not the BOOTP server.
2353 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2354 after the configured retry count, the call will fail
2355 instead of starting over. This can be used to fail over
2356 to Link-local IP address configuration if the DHCP server
2359 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2360 serverip from a DHCP server, it is possible that more
2361 than one DNS serverip is offered to the client.
2362 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2363 serverip will be stored in the additional environment
2364 variable "dnsip2". The first DNS serverip is always
2365 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2368 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2369 to do a dynamic update of a DNS server. To do this, they
2370 need the hostname of the DHCP requester.
2371 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2372 of the "hostname" environment variable is passed as
2373 option 12 to the DHCP server.
2375 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2377 A 32bit value in microseconds for a delay between
2378 receiving a "DHCP Offer" and sending the "DHCP Request".
2379 This fixes a problem with certain DHCP servers that don't
2380 respond 100% of the time to a "DHCP request". E.g. On an
2381 AT91RM9200 processor running at 180MHz, this delay needed
2382 to be *at least* 15,000 usec before a Windows Server 2003
2383 DHCP server would reply 100% of the time. I recommend at
2384 least 50,000 usec to be safe. The alternative is to hope
2385 that one of the retries will be successful but note that
2386 the DHCP timeout and retry process takes a longer than
2389 - Link-local IP address negotiation:
2390 Negotiate with other link-local clients on the local network
2391 for an address that doesn't require explicit configuration.
2392 This is especially useful if a DHCP server cannot be guaranteed
2393 to exist in all environments that the device must operate.
2395 See doc/README.link-local for more information.
2398 CONFIG_CDP_DEVICE_ID
2400 The device id used in CDP trigger frames.
2402 CONFIG_CDP_DEVICE_ID_PREFIX
2404 A two character string which is prefixed to the MAC address
2409 A printf format string which contains the ascii name of
2410 the port. Normally is set to "eth%d" which sets
2411 eth0 for the first Ethernet, eth1 for the second etc.
2413 CONFIG_CDP_CAPABILITIES
2415 A 32bit integer which indicates the device capabilities;
2416 0x00000010 for a normal host which does not forwards.
2420 An ascii string containing the version of the software.
2424 An ascii string containing the name of the platform.
2428 A 32bit integer sent on the trigger.
2430 CONFIG_CDP_POWER_CONSUMPTION
2432 A 16bit integer containing the power consumption of the
2433 device in .1 of milliwatts.
2435 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2437 A byte containing the id of the VLAN.
2439 - Status LED: CONFIG_STATUS_LED
2441 Several configurations allow to display the current
2442 status using a LED. For instance, the LED will blink
2443 fast while running U-Boot code, stop blinking as
2444 soon as a reply to a BOOTP request was received, and
2445 start blinking slow once the Linux kernel is running
2446 (supported by a status LED driver in the Linux
2447 kernel). Defining CONFIG_STATUS_LED enables this
2453 The status LED can be connected to a GPIO pin.
2454 In such cases, the gpio_led driver can be used as a
2455 status LED backend implementation. Define CONFIG_GPIO_LED
2456 to include the gpio_led driver in the U-Boot binary.
2458 CONFIG_GPIO_LED_INVERTED_TABLE
2459 Some GPIO connected LEDs may have inverted polarity in which
2460 case the GPIO high value corresponds to LED off state and
2461 GPIO low value corresponds to LED on state.
2462 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2463 with a list of GPIO LEDs that have inverted polarity.
2465 - CAN Support: CONFIG_CAN_DRIVER
2467 Defining CONFIG_CAN_DRIVER enables CAN driver support
2468 on those systems that support this (optional)
2469 feature, like the TQM8xxL modules.
2471 - I2C Support: CONFIG_SYS_I2C
2473 This enable the NEW i2c subsystem, and will allow you to use
2474 i2c commands at the u-boot command line (as long as you set
2475 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2476 based realtime clock chips or other i2c devices. See
2477 common/cmd_i2c.c for a description of the command line
2480 ported i2c driver to the new framework:
2481 - drivers/i2c/soft_i2c.c:
2482 - activate first bus with CONFIG_SYS_I2C_SOFT define
2483 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2484 for defining speed and slave address
2485 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2486 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2487 for defining speed and slave address
2488 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2489 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2490 for defining speed and slave address
2491 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2492 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2493 for defining speed and slave address
2495 - drivers/i2c/fsl_i2c.c:
2496 - activate i2c driver with CONFIG_SYS_I2C_FSL
2497 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2498 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2499 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2501 - If your board supports a second fsl i2c bus, define
2502 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2503 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2504 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2507 - drivers/i2c/tegra_i2c.c:
2508 - activate this driver with CONFIG_SYS_I2C_TEGRA
2509 - This driver adds 4 i2c buses with a fix speed from
2510 100000 and the slave addr 0!
2512 - drivers/i2c/ppc4xx_i2c.c
2513 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2514 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2515 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2517 - drivers/i2c/i2c_mxc.c
2518 - activate this driver with CONFIG_SYS_I2C_MXC
2519 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2520 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2521 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2522 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2523 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2524 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2525 If those defines are not set, default value is 100000
2526 for speed, and 0 for slave.
2527 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2528 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2530 - drivers/i2c/rcar_i2c.c:
2531 - activate this driver with CONFIG_SYS_I2C_RCAR
2532 - This driver adds 4 i2c buses
2534 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2535 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2536 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2537 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2538 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2539 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2540 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2541 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2542 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2544 - drivers/i2c/sh_i2c.c:
2545 - activate this driver with CONFIG_SYS_I2C_SH
2546 - This driver adds from 2 to 5 i2c buses
2548 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2549 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2550 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2551 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2552 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2553 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2554 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2555 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2556 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2557 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2558 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2559 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2560 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2562 - drivers/i2c/omap24xx_i2c.c
2563 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2564 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2565 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2566 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2567 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2568 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2569 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2570 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2571 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2572 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2573 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2575 - drivers/i2c/zynq_i2c.c
2576 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2577 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2578 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2580 - drivers/i2c/s3c24x0_i2c.c:
2581 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2582 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2583 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2584 with a fix speed from 100000 and the slave addr 0!
2586 - drivers/i2c/ihs_i2c.c
2587 - activate this driver with CONFIG_SYS_I2C_IHS
2588 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2589 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2590 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2591 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2592 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2593 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2594 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2595 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2596 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2597 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2598 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2599 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2603 CONFIG_SYS_NUM_I2C_BUSES
2604 Hold the number of i2c buses you want to use. If you
2605 don't use/have i2c muxes on your i2c bus, this
2606 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2609 CONFIG_SYS_I2C_DIRECT_BUS
2610 define this, if you don't use i2c muxes on your hardware.
2611 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2614 CONFIG_SYS_I2C_MAX_HOPS
2615 define how many muxes are maximal consecutively connected
2616 on one i2c bus. If you not use i2c muxes, omit this
2619 CONFIG_SYS_I2C_BUSES
2620 hold a list of buses you want to use, only used if
2621 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2622 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2623 CONFIG_SYS_NUM_I2C_BUSES = 9:
2625 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2626 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2627 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2628 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2629 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2630 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2631 {1, {I2C_NULL_HOP}}, \
2632 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2633 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2637 bus 0 on adapter 0 without a mux
2638 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2639 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2640 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2641 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2642 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2643 bus 6 on adapter 1 without a mux
2644 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2645 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2647 If you do not have i2c muxes on your board, omit this define.
2649 - Legacy I2C Support: CONFIG_HARD_I2C
2651 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2652 provides the following compelling advantages:
2654 - more than one i2c adapter is usable
2655 - approved multibus support
2656 - better i2c mux support
2658 ** Please consider updating your I2C driver now. **
2660 These enable legacy I2C serial bus commands. Defining
2661 CONFIG_HARD_I2C will include the appropriate I2C driver
2662 for the selected CPU.
2664 This will allow you to use i2c commands at the u-boot
2665 command line (as long as you set CONFIG_CMD_I2C in
2666 CONFIG_COMMANDS) and communicate with i2c based realtime
2667 clock chips. See common/cmd_i2c.c for a description of the
2668 command line interface.
2670 CONFIG_HARD_I2C selects a hardware I2C controller.
2672 There are several other quantities that must also be
2673 defined when you define CONFIG_HARD_I2C.
2675 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2676 to be the frequency (in Hz) at which you wish your i2c bus
2677 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2678 the CPU's i2c node address).
2680 Now, the u-boot i2c code for the mpc8xx
2681 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2682 and so its address should therefore be cleared to 0 (See,
2683 eg, MPC823e User's Manual p.16-473). So, set
2684 CONFIG_SYS_I2C_SLAVE to 0.
2686 CONFIG_SYS_I2C_INIT_MPC5XXX
2688 When a board is reset during an i2c bus transfer
2689 chips might think that the current transfer is still
2690 in progress. Reset the slave devices by sending start
2691 commands until the slave device responds.
2693 That's all that's required for CONFIG_HARD_I2C.
2695 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2696 then the following macros need to be defined (examples are
2697 from include/configs/lwmon.h):
2701 (Optional). Any commands necessary to enable the I2C
2702 controller or configure ports.
2704 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2708 (Only for MPC8260 CPU). The I/O port to use (the code
2709 assumes both bits are on the same port). Valid values
2710 are 0..3 for ports A..D.
2714 The code necessary to make the I2C data line active
2715 (driven). If the data line is open collector, this
2718 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2722 The code necessary to make the I2C data line tri-stated
2723 (inactive). If the data line is open collector, this
2726 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2730 Code that returns true if the I2C data line is high,
2733 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2737 If <bit> is true, sets the I2C data line high. If it
2738 is false, it clears it (low).
2740 eg: #define I2C_SDA(bit) \
2741 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2742 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2746 If <bit> is true, sets the I2C clock line high. If it
2747 is false, it clears it (low).
2749 eg: #define I2C_SCL(bit) \
2750 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2751 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2755 This delay is invoked four times per clock cycle so this
2756 controls the rate of data transfer. The data rate thus
2757 is 1 / (I2C_DELAY * 4). Often defined to be something
2760 #define I2C_DELAY udelay(2)
2762 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2764 If your arch supports the generic GPIO framework (asm/gpio.h),
2765 then you may alternatively define the two GPIOs that are to be
2766 used as SCL / SDA. Any of the previous I2C_xxx macros will
2767 have GPIO-based defaults assigned to them as appropriate.
2769 You should define these to the GPIO value as given directly to
2770 the generic GPIO functions.
2772 CONFIG_SYS_I2C_INIT_BOARD
2774 When a board is reset during an i2c bus transfer
2775 chips might think that the current transfer is still
2776 in progress. On some boards it is possible to access
2777 the i2c SCLK line directly, either by using the
2778 processor pin as a GPIO or by having a second pin
2779 connected to the bus. If this option is defined a
2780 custom i2c_init_board() routine in boards/xxx/board.c
2781 is run early in the boot sequence.
2783 CONFIG_SYS_I2C_BOARD_LATE_INIT
2785 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2786 defined a custom i2c_board_late_init() routine in
2787 boards/xxx/board.c is run AFTER the operations in i2c_init()
2788 is completed. This callpoint can be used to unreset i2c bus
2789 using CPU i2c controller register accesses for CPUs whose i2c
2790 controller provide such a method. It is called at the end of
2791 i2c_init() to allow i2c_init operations to setup the i2c bus
2792 controller on the CPU (e.g. setting bus speed & slave address).
2794 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2796 This option enables configuration of bi_iic_fast[] flags
2797 in u-boot bd_info structure based on u-boot environment
2798 variable "i2cfast". (see also i2cfast)
2800 CONFIG_I2C_MULTI_BUS
2802 This option allows the use of multiple I2C buses, each of which
2803 must have a controller. At any point in time, only one bus is
2804 active. To switch to a different bus, use the 'i2c dev' command.
2805 Note that bus numbering is zero-based.
2807 CONFIG_SYS_I2C_NOPROBES
2809 This option specifies a list of I2C devices that will be skipped
2810 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2811 is set, specify a list of bus-device pairs. Otherwise, specify
2812 a 1D array of device addresses
2815 #undef CONFIG_I2C_MULTI_BUS
2816 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2818 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2820 #define CONFIG_I2C_MULTI_BUS
2821 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2823 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2825 CONFIG_SYS_SPD_BUS_NUM
2827 If defined, then this indicates the I2C bus number for DDR SPD.
2828 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2830 CONFIG_SYS_RTC_BUS_NUM
2832 If defined, then this indicates the I2C bus number for the RTC.
2833 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2835 CONFIG_SYS_DTT_BUS_NUM
2837 If defined, then this indicates the I2C bus number for the DTT.
2838 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2840 CONFIG_SYS_I2C_DTT_ADDR:
2842 If defined, specifies the I2C address of the DTT device.
2843 If not defined, then U-Boot uses predefined value for
2844 specified DTT device.
2846 CONFIG_SOFT_I2C_READ_REPEATED_START
2848 defining this will force the i2c_read() function in
2849 the soft_i2c driver to perform an I2C repeated start
2850 between writing the address pointer and reading the
2851 data. If this define is omitted the default behaviour
2852 of doing a stop-start sequence will be used. Most I2C
2853 devices can use either method, but some require one or
2856 - SPI Support: CONFIG_SPI
2858 Enables SPI driver (so far only tested with
2859 SPI EEPROM, also an instance works with Crystal A/D and
2860 D/As on the SACSng board)
2864 Enables the driver for SPI controller on SuperH. Currently
2865 only SH7757 is supported.
2869 Enables extended (16-bit) SPI EEPROM addressing.
2870 (symmetrical to CONFIG_I2C_X)
2874 Enables a software (bit-bang) SPI driver rather than
2875 using hardware support. This is a general purpose
2876 driver that only requires three general I/O port pins
2877 (two outputs, one input) to function. If this is
2878 defined, the board configuration must define several
2879 SPI configuration items (port pins to use, etc). For
2880 an example, see include/configs/sacsng.h.
2884 Enables a hardware SPI driver for general-purpose reads
2885 and writes. As with CONFIG_SOFT_SPI, the board configuration
2886 must define a list of chip-select function pointers.
2887 Currently supported on some MPC8xxx processors. For an
2888 example, see include/configs/mpc8349emds.h.
2892 Enables the driver for the SPI controllers on i.MX and MXC
2893 SoCs. Currently i.MX31/35/51 are supported.
2895 CONFIG_SYS_SPI_MXC_WAIT
2896 Timeout for waiting until spi transfer completed.
2897 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2899 - FPGA Support: CONFIG_FPGA
2901 Enables FPGA subsystem.
2903 CONFIG_FPGA_<vendor>
2905 Enables support for specific chip vendors.
2908 CONFIG_FPGA_<family>
2910 Enables support for FPGA family.
2911 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2915 Specify the number of FPGA devices to support.
2917 CONFIG_CMD_FPGA_LOADMK
2919 Enable support for fpga loadmk command
2921 CONFIG_CMD_FPGA_LOADP
2923 Enable support for fpga loadp command - load partial bitstream
2925 CONFIG_CMD_FPGA_LOADBP
2927 Enable support for fpga loadbp command - load partial bitstream
2930 CONFIG_SYS_FPGA_PROG_FEEDBACK
2932 Enable printing of hash marks during FPGA configuration.
2934 CONFIG_SYS_FPGA_CHECK_BUSY
2936 Enable checks on FPGA configuration interface busy
2937 status by the configuration function. This option
2938 will require a board or device specific function to
2943 If defined, a function that provides delays in the FPGA
2944 configuration driver.
2946 CONFIG_SYS_FPGA_CHECK_CTRLC
2947 Allow Control-C to interrupt FPGA configuration
2949 CONFIG_SYS_FPGA_CHECK_ERROR
2951 Check for configuration errors during FPGA bitfile
2952 loading. For example, abort during Virtex II
2953 configuration if the INIT_B line goes low (which
2954 indicated a CRC error).
2956 CONFIG_SYS_FPGA_WAIT_INIT
2958 Maximum time to wait for the INIT_B line to de-assert
2959 after PROB_B has been de-asserted during a Virtex II
2960 FPGA configuration sequence. The default time is 500
2963 CONFIG_SYS_FPGA_WAIT_BUSY
2965 Maximum time to wait for BUSY to de-assert during
2966 Virtex II FPGA configuration. The default is 5 ms.
2968 CONFIG_SYS_FPGA_WAIT_CONFIG
2970 Time to wait after FPGA configuration. The default is
2973 - Configuration Management:
2976 Some SoCs need special image types (e.g. U-Boot binary
2977 with a special header) as build targets. By defining
2978 CONFIG_BUILD_TARGET in the SoC / board header, this
2979 special image will be automatically built upon calling
2984 If defined, this string will be added to the U-Boot
2985 version information (U_BOOT_VERSION)
2987 - Vendor Parameter Protection:
2989 U-Boot considers the values of the environment
2990 variables "serial#" (Board Serial Number) and
2991 "ethaddr" (Ethernet Address) to be parameters that
2992 are set once by the board vendor / manufacturer, and
2993 protects these variables from casual modification by
2994 the user. Once set, these variables are read-only,
2995 and write or delete attempts are rejected. You can
2996 change this behaviour:
2998 If CONFIG_ENV_OVERWRITE is #defined in your config
2999 file, the write protection for vendor parameters is
3000 completely disabled. Anybody can change or delete
3003 Alternatively, if you #define _both_ CONFIG_ETHADDR
3004 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
3005 Ethernet address is installed in the environment,
3006 which can be changed exactly ONCE by the user. [The
3007 serial# is unaffected by this, i. e. it remains
3010 The same can be accomplished in a more flexible way
3011 for any variable by configuring the type of access
3012 to allow for those variables in the ".flags" variable
3013 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3018 Define this variable to enable the reservation of
3019 "protected RAM", i. e. RAM which is not overwritten
3020 by U-Boot. Define CONFIG_PRAM to hold the number of
3021 kB you want to reserve for pRAM. You can overwrite
3022 this default value by defining an environment
3023 variable "pram" to the number of kB you want to
3024 reserve. Note that the board info structure will
3025 still show the full amount of RAM. If pRAM is
3026 reserved, a new environment variable "mem" will
3027 automatically be defined to hold the amount of
3028 remaining RAM in a form that can be passed as boot
3029 argument to Linux, for instance like that:
3031 setenv bootargs ... mem=\${mem}
3034 This way you can tell Linux not to use this memory,
3035 either, which results in a memory region that will
3036 not be affected by reboots.
3038 *WARNING* If your board configuration uses automatic
3039 detection of the RAM size, you must make sure that
3040 this memory test is non-destructive. So far, the
3041 following board configurations are known to be
3044 IVMS8, IVML24, SPD8xx, TQM8xxL,
3045 HERMES, IP860, RPXlite, LWMON,
3048 - Access to physical memory region (> 4GB)
3049 Some basic support is provided for operations on memory not
3050 normally accessible to U-Boot - e.g. some architectures
3051 support access to more than 4GB of memory on 32-bit
3052 machines using physical address extension or similar.
3053 Define CONFIG_PHYSMEM to access this basic support, which
3054 currently only supports clearing the memory.
3059 Define this variable to stop the system in case of a
3060 fatal error, so that you have to reset it manually.
3061 This is probably NOT a good idea for an embedded
3062 system where you want the system to reboot
3063 automatically as fast as possible, but it may be
3064 useful during development since you can try to debug
3065 the conditions that lead to the situation.
3067 CONFIG_NET_RETRY_COUNT
3069 This variable defines the number of retries for
3070 network operations like ARP, RARP, TFTP, or BOOTP
3071 before giving up the operation. If not defined, a
3072 default value of 5 is used.
3076 Timeout waiting for an ARP reply in milliseconds.
3080 Timeout in milliseconds used in NFS protocol.
3081 If you encounter "ERROR: Cannot umount" in nfs command,
3082 try longer timeout such as
3083 #define CONFIG_NFS_TIMEOUT 10000UL
3085 - Command Interpreter:
3086 CONFIG_AUTO_COMPLETE
3088 Enable auto completion of commands using TAB.
3090 CONFIG_SYS_PROMPT_HUSH_PS2
3092 This defines the secondary prompt string, which is
3093 printed when the command interpreter needs more input
3094 to complete a command. Usually "> ".
3098 In the current implementation, the local variables
3099 space and global environment variables space are
3100 separated. Local variables are those you define by
3101 simply typing `name=value'. To access a local
3102 variable later on, you have write `$name' or
3103 `${name}'; to execute the contents of a variable
3104 directly type `$name' at the command prompt.
3106 Global environment variables are those you use
3107 setenv/printenv to work with. To run a command stored
3108 in such a variable, you need to use the run command,
3109 and you must not use the '$' sign to access them.
3111 To store commands and special characters in a
3112 variable, please use double quotation marks
3113 surrounding the whole text of the variable, instead
3114 of the backslashes before semicolons and special
3117 - Command Line Editing and History:
3118 CONFIG_CMDLINE_EDITING
3120 Enable editing and History functions for interactive
3121 command line input operations
3123 - Default Environment:
3124 CONFIG_EXTRA_ENV_SETTINGS
3126 Define this to contain any number of null terminated
3127 strings (variable = value pairs) that will be part of
3128 the default environment compiled into the boot image.
3130 For example, place something like this in your
3131 board's config file:
3133 #define CONFIG_EXTRA_ENV_SETTINGS \
3137 Warning: This method is based on knowledge about the
3138 internal format how the environment is stored by the
3139 U-Boot code. This is NOT an official, exported
3140 interface! Although it is unlikely that this format
3141 will change soon, there is no guarantee either.
3142 You better know what you are doing here.
3144 Note: overly (ab)use of the default environment is
3145 discouraged. Make sure to check other ways to preset
3146 the environment like the "source" command or the
3149 CONFIG_ENV_VARS_UBOOT_CONFIG
3151 Define this in order to add variables describing the
3152 U-Boot build configuration to the default environment.
3153 These will be named arch, cpu, board, vendor, and soc.
3155 Enabling this option will cause the following to be defined:
3163 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3165 Define this in order to add variables describing certain
3166 run-time determined information about the hardware to the
3167 environment. These will be named board_name, board_rev.
3169 CONFIG_DELAY_ENVIRONMENT
3171 Normally the environment is loaded when the board is
3172 initialised so that it is available to U-Boot. This inhibits
3173 that so that the environment is not available until
3174 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3175 this is instead controlled by the value of
3176 /config/load-environment.
3178 - DataFlash Support:
3179 CONFIG_HAS_DATAFLASH
3181 Defining this option enables DataFlash features and
3182 allows to read/write in Dataflash via the standard
3185 - Serial Flash support
3188 Defining this option enables SPI flash commands
3189 'sf probe/read/write/erase/update'.
3191 Usage requires an initial 'probe' to define the serial
3192 flash parameters, followed by read/write/erase/update
3195 The following defaults may be provided by the platform
3196 to handle the common case when only a single serial
3197 flash is present on the system.
3199 CONFIG_SF_DEFAULT_BUS Bus identifier
3200 CONFIG_SF_DEFAULT_CS Chip-select
3201 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3202 CONFIG_SF_DEFAULT_SPEED in Hz
3206 Define this option to include a destructive SPI flash
3209 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3211 Define this option to use the Bank addr/Extended addr
3212 support on SPI flashes which has size > 16Mbytes.
3214 CONFIG_SF_DUAL_FLASH Dual flash memories
3216 Define this option to use dual flash support where two flash
3217 memories can be connected with a given cs line.
3218 Currently Xilinx Zynq qspi supports these type of connections.
3220 - SystemACE Support:
3223 Adding this option adds support for Xilinx SystemACE
3224 chips attached via some sort of local bus. The address
3225 of the chip must also be defined in the
3226 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3228 #define CONFIG_SYSTEMACE
3229 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3231 When SystemACE support is added, the "ace" device type
3232 becomes available to the fat commands, i.e. fatls.
3234 - TFTP Fixed UDP Port:
3237 If this is defined, the environment variable tftpsrcp
3238 is used to supply the TFTP UDP source port value.
3239 If tftpsrcp isn't defined, the normal pseudo-random port
3240 number generator is used.
3242 Also, the environment variable tftpdstp is used to supply
3243 the TFTP UDP destination port value. If tftpdstp isn't
3244 defined, the normal port 69 is used.
3246 The purpose for tftpsrcp is to allow a TFTP server to
3247 blindly start the TFTP transfer using the pre-configured
3248 target IP address and UDP port. This has the effect of
3249 "punching through" the (Windows XP) firewall, allowing
3250 the remainder of the TFTP transfer to proceed normally.
3251 A better solution is to properly configure the firewall,
3252 but sometimes that is not allowed.
3257 This enables a generic 'hash' command which can produce
3258 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3262 Enable the hash verify command (hash -v). This adds to code
3265 CONFIG_SHA1 - This option enables support of hashing using SHA1
3266 algorithm. The hash is calculated in software.
3267 CONFIG_SHA256 - This option enables support of hashing using
3268 SHA256 algorithm. The hash is calculated in software.
3269 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3270 for SHA1/SHA256 hashing.
3271 This affects the 'hash' command and also the
3272 hash_lookup_algo() function.
3273 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3274 hardware-acceleration for SHA1/SHA256 progressive hashing.
3275 Data can be streamed in a block at a time and the hashing
3276 is performed in hardware.
3278 Note: There is also a sha1sum command, which should perhaps
3279 be deprecated in favour of 'hash sha1'.
3281 - Freescale i.MX specific commands:
3282 CONFIG_CMD_HDMIDETECT
3283 This enables 'hdmidet' command which returns true if an
3284 HDMI monitor is detected. This command is i.MX 6 specific.
3287 This enables the 'bmode' (bootmode) command for forcing
3288 a boot from specific media.
3290 This is useful for forcing the ROM's usb downloader to
3291 activate upon a watchdog reset which is nice when iterating
3292 on U-Boot. Using the reset button or running bmode normal
3293 will set it back to normal. This command currently
3294 supports i.MX53 and i.MX6.
3299 This enables the RSA algorithm used for FIT image verification
3300 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3302 The Modular Exponentiation algorithm in RSA is implemented using
3303 driver model. So CONFIG_DM needs to be enabled by default for this
3304 library to function.
3306 The signing part is build into mkimage regardless of this
3307 option. The software based modular exponentiation is built into
3308 mkimage irrespective of this option.
3310 - bootcount support:
3311 CONFIG_BOOTCOUNT_LIMIT
3313 This enables the bootcounter support, see:
3314 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3317 enable special bootcounter support on at91sam9xe based boards.
3319 enable special bootcounter support on blackfin based boards.
3321 enable special bootcounter support on da850 based boards.
3322 CONFIG_BOOTCOUNT_RAM
3323 enable support for the bootcounter in RAM
3324 CONFIG_BOOTCOUNT_I2C
3325 enable support for the bootcounter on an i2c (like RTC) device.
3326 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3327 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3329 CONFIG_BOOTCOUNT_ALEN = address len
3331 - Show boot progress:
3332 CONFIG_SHOW_BOOT_PROGRESS
3334 Defining this option allows to add some board-
3335 specific code (calling a user-provided function
3336 "show_boot_progress(int)") that enables you to show
3337 the system's boot progress on some display (for
3338 example, some LED's) on your board. At the moment,
3339 the following checkpoints are implemented:
3342 Legacy uImage format:
3345 1 common/cmd_bootm.c before attempting to boot an image
3346 -1 common/cmd_bootm.c Image header has bad magic number
3347 2 common/cmd_bootm.c Image header has correct magic number
3348 -2 common/cmd_bootm.c Image header has bad checksum
3349 3 common/cmd_bootm.c Image header has correct checksum
3350 -3 common/cmd_bootm.c Image data has bad checksum
3351 4 common/cmd_bootm.c Image data has correct checksum
3352 -4 common/cmd_bootm.c Image is for unsupported architecture
3353 5 common/cmd_bootm.c Architecture check OK
3354 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3355 6 common/cmd_bootm.c Image Type check OK
3356 -6 common/cmd_bootm.c gunzip uncompression error
3357 -7 common/cmd_bootm.c Unimplemented compression type
3358 7 common/cmd_bootm.c Uncompression OK
3359 8 common/cmd_bootm.c No uncompress/copy overwrite error
3360 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3362 9 common/image.c Start initial ramdisk verification
3363 -10 common/image.c Ramdisk header has bad magic number
3364 -11 common/image.c Ramdisk header has bad checksum
3365 10 common/image.c Ramdisk header is OK
3366 -12 common/image.c Ramdisk data has bad checksum
3367 11 common/image.c Ramdisk data has correct checksum
3368 12 common/image.c Ramdisk verification complete, start loading
3369 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3370 13 common/image.c Start multifile image verification
3371 14 common/image.c No initial ramdisk, no multifile, continue.
3373 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3375 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3376 -31 post/post.c POST test failed, detected by post_output_backlog()
3377 -32 post/post.c POST test failed, detected by post_run_single()
3379 34 common/cmd_doc.c before loading a Image from a DOC device
3380 -35 common/cmd_doc.c Bad usage of "doc" command
3381 35 common/cmd_doc.c correct usage of "doc" command
3382 -36 common/cmd_doc.c No boot device
3383 36 common/cmd_doc.c correct boot device
3384 -37 common/cmd_doc.c Unknown Chip ID on boot device
3385 37 common/cmd_doc.c correct chip ID found, device available
3386 -38 common/cmd_doc.c Read Error on boot device
3387 38 common/cmd_doc.c reading Image header from DOC device OK
3388 -39 common/cmd_doc.c Image header has bad magic number
3389 39 common/cmd_doc.c Image header has correct magic number
3390 -40 common/cmd_doc.c Error reading Image from DOC device
3391 40 common/cmd_doc.c Image header has correct magic number
3392 41 common/cmd_ide.c before loading a Image from a IDE device
3393 -42 common/cmd_ide.c Bad usage of "ide" command
3394 42 common/cmd_ide.c correct usage of "ide" command
3395 -43 common/cmd_ide.c No boot device
3396 43 common/cmd_ide.c boot device found
3397 -44 common/cmd_ide.c Device not available
3398 44 common/cmd_ide.c Device available
3399 -45 common/cmd_ide.c wrong partition selected
3400 45 common/cmd_ide.c partition selected
3401 -46 common/cmd_ide.c Unknown partition table
3402 46 common/cmd_ide.c valid partition table found
3403 -47 common/cmd_ide.c Invalid partition type
3404 47 common/cmd_ide.c correct partition type
3405 -48 common/cmd_ide.c Error reading Image Header on boot device
3406 48 common/cmd_ide.c reading Image Header from IDE device OK
3407 -49 common/cmd_ide.c Image header has bad magic number
3408 49 common/cmd_ide.c Image header has correct magic number
3409 -50 common/cmd_ide.c Image header has bad checksum
3410 50 common/cmd_ide.c Image header has correct checksum
3411 -51 common/cmd_ide.c Error reading Image from IDE device
3412 51 common/cmd_ide.c reading Image from IDE device OK
3413 52 common/cmd_nand.c before loading a Image from a NAND device
3414 -53 common/cmd_nand.c Bad usage of "nand" command
3415 53 common/cmd_nand.c correct usage of "nand" command
3416 -54 common/cmd_nand.c No boot device
3417 54 common/cmd_nand.c boot device found
3418 -55 common/cmd_nand.c Unknown Chip ID on boot device
3419 55 common/cmd_nand.c correct chip ID found, device available
3420 -56 common/cmd_nand.c Error reading Image Header on boot device
3421 56 common/cmd_nand.c reading Image Header from NAND device OK
3422 -57 common/cmd_nand.c Image header has bad magic number
3423 57 common/cmd_nand.c Image header has correct magic number
3424 -58 common/cmd_nand.c Error reading Image from NAND device
3425 58 common/cmd_nand.c reading Image from NAND device OK
3427 -60 common/env_common.c Environment has a bad CRC, using default
3429 64 net/eth.c starting with Ethernet configuration.
3430 -64 net/eth.c no Ethernet found.
3431 65 net/eth.c Ethernet found.
3433 -80 common/cmd_net.c usage wrong
3434 80 common/cmd_net.c before calling net_loop()
3435 -81 common/cmd_net.c some error in net_loop() occurred
3436 81 common/cmd_net.c net_loop() back without error
3437 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3438 82 common/cmd_net.c trying automatic boot
3439 83 common/cmd_net.c running "source" command
3440 -83 common/cmd_net.c some error in automatic boot or "source" command
3441 84 common/cmd_net.c end without errors
3446 100 common/cmd_bootm.c Kernel FIT Image has correct format
3447 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3448 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3449 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3450 102 common/cmd_bootm.c Kernel unit name specified
3451 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3452 103 common/cmd_bootm.c Found configuration node
3453 104 common/cmd_bootm.c Got kernel subimage node offset
3454 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3455 105 common/cmd_bootm.c Kernel subimage hash verification OK
3456 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3457 106 common/cmd_bootm.c Architecture check OK
3458 -106 common/cmd_bootm.c Kernel subimage has wrong type
3459 107 common/cmd_bootm.c Kernel subimage type OK
3460 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3461 108 common/cmd_bootm.c Got kernel subimage data/size
3462 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3463 -109 common/cmd_bootm.c Can't get kernel subimage type
3464 -110 common/cmd_bootm.c Can't get kernel subimage comp
3465 -111 common/cmd_bootm.c Can't get kernel subimage os
3466 -112 common/cmd_bootm.c Can't get kernel subimage load address
3467 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3469 120 common/image.c Start initial ramdisk verification
3470 -120 common/image.c Ramdisk FIT image has incorrect format
3471 121 common/image.c Ramdisk FIT image has correct format
3472 122 common/image.c No ramdisk subimage unit name, using configuration
3473 -122 common/image.c Can't get configuration for ramdisk subimage
3474 123 common/image.c Ramdisk unit name specified
3475 -124 common/image.c Can't get ramdisk subimage node offset
3476 125 common/image.c Got ramdisk subimage node offset
3477 -125 common/image.c Ramdisk subimage hash verification failed
3478 126 common/image.c Ramdisk subimage hash verification OK
3479 -126 common/image.c Ramdisk subimage for unsupported architecture
3480 127 common/image.c Architecture check OK
3481 -127 common/image.c Can't get ramdisk subimage data/size
3482 128 common/image.c Got ramdisk subimage data/size
3483 129 common/image.c Can't get ramdisk load address
3484 -129 common/image.c Got ramdisk load address
3486 -130 common/cmd_doc.c Incorrect FIT image format
3487 131 common/cmd_doc.c FIT image format OK
3489 -140 common/cmd_ide.c Incorrect FIT image format
3490 141 common/cmd_ide.c FIT image format OK
3492 -150 common/cmd_nand.c Incorrect FIT image format
3493 151 common/cmd_nand.c FIT image format OK
3495 - legacy image format:
3496 CONFIG_IMAGE_FORMAT_LEGACY
3497 enables the legacy image format support in U-Boot.
3500 enabled if CONFIG_FIT_SIGNATURE is not defined.
3502 CONFIG_DISABLE_IMAGE_LEGACY
3503 disable the legacy image format
3505 This define is introduced, as the legacy image format is
3506 enabled per default for backward compatibility.
3508 - FIT image support:
3510 Enable support for the FIT uImage format.
3512 CONFIG_FIT_BEST_MATCH
3513 When no configuration is explicitly selected, default to the
3514 one whose fdt's compatibility field best matches that of
3515 U-Boot itself. A match is considered "best" if it matches the
3516 most specific compatibility entry of U-Boot's fdt's root node.
3517 The order of entries in the configuration's fdt is ignored.
3519 CONFIG_FIT_SIGNATURE
3520 This option enables signature verification of FIT uImages,
3521 using a hash signed and verified using RSA. If
3522 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3523 hashing is available using hardware, RSA library will use it.
3524 See doc/uImage.FIT/signature.txt for more details.
3526 WARNING: When relying on signed FIT images with required
3527 signature check the legacy image format is default
3528 disabled. If a board need legacy image format support
3529 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3531 CONFIG_FIT_DISABLE_SHA256
3532 Supporting SHA256 hashes has quite an impact on binary size.
3533 For constrained systems sha256 hash support can be disabled
3536 - Standalone program support:
3537 CONFIG_STANDALONE_LOAD_ADDR
3539 This option defines a board specific value for the
3540 address where standalone program gets loaded, thus
3541 overwriting the architecture dependent default
3544 - Frame Buffer Address:
3547 Define CONFIG_FB_ADDR if you want to use specific
3548 address for frame buffer. This is typically the case
3549 when using a graphics controller has separate video
3550 memory. U-Boot will then place the frame buffer at
3551 the given address instead of dynamically reserving it
3552 in system RAM by calling lcd_setmem(), which grabs
3553 the memory for the frame buffer depending on the
3554 configured panel size.
3556 Please see board_init_f function.
3558 - Automatic software updates via TFTP server
3560 CONFIG_UPDATE_TFTP_CNT_MAX
3561 CONFIG_UPDATE_TFTP_MSEC_MAX
3563 These options enable and control the auto-update feature;
3564 for a more detailed description refer to doc/README.update.
3566 - MTD Support (mtdparts command, UBI support)
3569 Adds the MTD device infrastructure from the Linux kernel.
3570 Needed for mtdparts command support.
3572 CONFIG_MTD_PARTITIONS
3574 Adds the MTD partitioning infrastructure from the Linux
3575 kernel. Needed for UBI support.
3580 Adds commands for interacting with MTD partitions formatted
3581 with the UBI flash translation layer
3583 Requires also defining CONFIG_RBTREE
3585 CONFIG_UBI_SILENCE_MSG
3587 Make the verbose messages from UBI stop printing. This leaves
3588 warnings and errors enabled.
3591 CONFIG_MTD_UBI_WL_THRESHOLD
3592 This parameter defines the maximum difference between the highest
3593 erase counter value and the lowest erase counter value of eraseblocks
3594 of UBI devices. When this threshold is exceeded, UBI starts performing
3595 wear leveling by means of moving data from eraseblock with low erase
3596 counter to eraseblocks with high erase counter.
3598 The default value should be OK for SLC NAND flashes, NOR flashes and
3599 other flashes which have eraseblock life-cycle 100000 or more.
3600 However, in case of MLC NAND flashes which typically have eraseblock
3601 life-cycle less than 10000, the threshold should be lessened (e.g.,
3602 to 128 or 256, although it does not have to be power of 2).
3606 CONFIG_MTD_UBI_BEB_LIMIT
3607 This option specifies the maximum bad physical eraseblocks UBI
3608 expects on the MTD device (per 1024 eraseblocks). If the
3609 underlying flash does not admit of bad eraseblocks (e.g. NOR
3610 flash), this value is ignored.
3612 NAND datasheets often specify the minimum and maximum NVM
3613 (Number of Valid Blocks) for the flashes' endurance lifetime.
3614 The maximum expected bad eraseblocks per 1024 eraseblocks
3615 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3616 which gives 20 for most NANDs (MaxNVB is basically the total
3617 count of eraseblocks on the chip).
3619 To put it differently, if this value is 20, UBI will try to
3620 reserve about 1.9% of physical eraseblocks for bad blocks
3621 handling. And that will be 1.9% of eraseblocks on the entire
3622 NAND chip, not just the MTD partition UBI attaches. This means
3623 that if you have, say, a NAND flash chip admits maximum 40 bad
3624 eraseblocks, and it is split on two MTD partitions of the same
3625 size, UBI will reserve 40 eraseblocks when attaching a
3630 CONFIG_MTD_UBI_FASTMAP
3631 Fastmap is a mechanism which allows attaching an UBI device
3632 in nearly constant time. Instead of scanning the whole MTD device it
3633 only has to locate a checkpoint (called fastmap) on the device.
3634 The on-flash fastmap contains all information needed to attach
3635 the device. Using fastmap makes only sense on large devices where
3636 attaching by scanning takes long. UBI will not automatically install
3637 a fastmap on old images, but you can set the UBI parameter
3638 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3639 that fastmap-enabled images are still usable with UBI implementations
3640 without fastmap support. On typical flash devices the whole fastmap
3641 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3643 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3644 Set this parameter to enable fastmap automatically on images
3651 Adds commands for interacting with UBI volumes formatted as
3652 UBIFS. UBIFS is read-only in u-boot.
3654 Requires UBI support as well as CONFIG_LZO
3656 CONFIG_UBIFS_SILENCE_MSG
3658 Make the verbose messages from UBIFS stop printing. This leaves
3659 warnings and errors enabled.
3663 Enable building of SPL globally.
3666 LDSCRIPT for linking the SPL binary.
3668 CONFIG_SPL_MAX_FOOTPRINT
3669 Maximum size in memory allocated to the SPL, BSS included.
3670 When defined, the linker checks that the actual memory
3671 used by SPL from _start to __bss_end does not exceed it.
3672 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3673 must not be both defined at the same time.
3676 Maximum size of the SPL image (text, data, rodata, and
3677 linker lists sections), BSS excluded.
3678 When defined, the linker checks that the actual size does
3681 CONFIG_SPL_TEXT_BASE
3682 TEXT_BASE for linking the SPL binary.
3684 CONFIG_SPL_RELOC_TEXT_BASE
3685 Address to relocate to. If unspecified, this is equal to
3686 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3688 CONFIG_SPL_BSS_START_ADDR
3689 Link address for the BSS within the SPL binary.
3691 CONFIG_SPL_BSS_MAX_SIZE
3692 Maximum size in memory allocated to the SPL BSS.
3693 When defined, the linker checks that the actual memory used
3694 by SPL from __bss_start to __bss_end does not exceed it.
3695 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3696 must not be both defined at the same time.
3699 Adress of the start of the stack SPL will use
3701 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3702 When defined, SPL will panic() if the image it has
3703 loaded does not have a signature.
3704 Defining this is useful when code which loads images
3705 in SPL cannot guarantee that absolutely all read errors
3707 An example is the LPC32XX MLC NAND driver, which will
3708 consider that a completely unreadable NAND block is bad,
3709 and thus should be skipped silently.
3711 CONFIG_SPL_RELOC_STACK
3712 Adress of the start of the stack SPL will use after
3713 relocation. If unspecified, this is equal to
3716 CONFIG_SYS_SPL_MALLOC_START
3717 Starting address of the malloc pool used in SPL.
3719 CONFIG_SYS_SPL_MALLOC_SIZE
3720 The size of the malloc pool used in SPL.
3722 CONFIG_SPL_FRAMEWORK
3723 Enable the SPL framework under common/. This framework
3724 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3725 NAND loading of the Linux Kernel.
3728 Enable booting directly to an OS from SPL.
3729 See also: doc/README.falcon
3731 CONFIG_SPL_DISPLAY_PRINT
3732 For ARM, enable an optional function to print more information
3733 about the running system.
3735 CONFIG_SPL_INIT_MINIMAL
3736 Arch init code should be built for a very small image
3738 CONFIG_SPL_LIBCOMMON_SUPPORT
3739 Support for common/libcommon.o in SPL binary
3741 CONFIG_SPL_LIBDISK_SUPPORT
3742 Support for disk/libdisk.o in SPL binary
3744 CONFIG_SPL_I2C_SUPPORT
3745 Support for drivers/i2c/libi2c.o in SPL binary
3747 CONFIG_SPL_GPIO_SUPPORT
3748 Support for drivers/gpio/libgpio.o in SPL binary
3750 CONFIG_SPL_MMC_SUPPORT
3751 Support for drivers/mmc/libmmc.o in SPL binary
3753 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3754 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3755 Address and partition on the MMC to load U-Boot from
3756 when the MMC is being used in raw mode.
3758 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3759 Partition on the MMC to load U-Boot from when the MMC is being
3762 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3763 Sector to load kernel uImage from when MMC is being
3764 used in raw mode (for Falcon mode)
3766 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3767 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3768 Sector and number of sectors to load kernel argument
3769 parameters from when MMC is being used in raw mode
3772 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3773 Partition on the MMC to load U-Boot from when the MMC is being
3776 CONFIG_SPL_FAT_SUPPORT
3777 Support for fs/fat/libfat.o in SPL binary
3779 CONFIG_SPL_EXT_SUPPORT
3780 Support for EXT filesystem in SPL binary
3782 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3783 Filename to read to load U-Boot when reading from filesystem
3785 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3786 Filename to read to load kernel uImage when reading
3787 from filesystem (for Falcon mode)
3789 CONFIG_SPL_FS_LOAD_ARGS_NAME
3790 Filename to read to load kernel argument parameters
3791 when reading from filesystem (for Falcon mode)
3793 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3794 Set this for NAND SPL on PPC mpc83xx targets, so that
3795 start.S waits for the rest of the SPL to load before
3796 continuing (the hardware starts execution after just
3797 loading the first page rather than the full 4K).
3799 CONFIG_SPL_SKIP_RELOCATE
3800 Avoid SPL relocation
3802 CONFIG_SPL_NAND_BASE
3803 Include nand_base.c in the SPL. Requires
3804 CONFIG_SPL_NAND_DRIVERS.
3806 CONFIG_SPL_NAND_DRIVERS
3807 SPL uses normal NAND drivers, not minimal drivers.
3810 Include standard software ECC in the SPL
3812 CONFIG_SPL_NAND_SIMPLE
3813 Support for NAND boot using simple NAND drivers that
3814 expose the cmd_ctrl() interface.
3816 CONFIG_SPL_MTD_SUPPORT
3817 Support for the MTD subsystem within SPL. Useful for
3818 environment on NAND support within SPL.
3820 CONFIG_SPL_NAND_RAW_ONLY
3821 Support to boot only raw u-boot.bin images. Use this only
3822 if you need to save space.
3824 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3825 Set for the SPL on PPC mpc8xxx targets, support for
3826 drivers/ddr/fsl/libddr.o in SPL binary.
3828 CONFIG_SPL_COMMON_INIT_DDR
3829 Set for common ddr init with serial presence detect in
3832 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3833 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3834 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3835 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3836 CONFIG_SYS_NAND_ECCBYTES
3837 Defines the size and behavior of the NAND that SPL uses
3840 CONFIG_SPL_NAND_BOOT
3841 Add support NAND boot
3843 CONFIG_SYS_NAND_U_BOOT_OFFS
3844 Location in NAND to read U-Boot from
3846 CONFIG_SYS_NAND_U_BOOT_DST
3847 Location in memory to load U-Boot to
3849 CONFIG_SYS_NAND_U_BOOT_SIZE
3850 Size of image to load
3852 CONFIG_SYS_NAND_U_BOOT_START
3853 Entry point in loaded image to jump to
3855 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3856 Define this if you need to first read the OOB and then the
3857 data. This is used, for example, on davinci platforms.
3859 CONFIG_SPL_OMAP3_ID_NAND
3860 Support for an OMAP3-specific set of functions to return the
3861 ID and MFR of the first attached NAND chip, if present.
3863 CONFIG_SPL_SERIAL_SUPPORT
3864 Support for drivers/serial/libserial.o in SPL binary
3866 CONFIG_SPL_SPI_FLASH_SUPPORT
3867 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3869 CONFIG_SPL_SPI_SUPPORT
3870 Support for drivers/spi/libspi.o in SPL binary
3872 CONFIG_SPL_RAM_DEVICE
3873 Support for running image already present in ram, in SPL binary
3875 CONFIG_SPL_LIBGENERIC_SUPPORT
3876 Support for lib/libgeneric.o in SPL binary
3878 CONFIG_SPL_ENV_SUPPORT
3879 Support for the environment operating in SPL binary
3881 CONFIG_SPL_NET_SUPPORT
3882 Support for the net/libnet.o in SPL binary.
3883 It conflicts with SPL env from storage medium specified by
3884 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3887 Image offset to which the SPL should be padded before appending
3888 the SPL payload. By default, this is defined as
3889 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3890 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3891 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3894 Final target image containing SPL and payload. Some SPLs
3895 use an arch-specific makefile fragment instead, for
3896 example if more than one image needs to be produced.
3898 CONFIG_FIT_SPL_PRINT
3899 Printing information about a FIT image adds quite a bit of
3900 code to SPL. So this is normally disabled in SPL. Use this
3901 option to re-enable it. This will affect the output of the
3902 bootm command when booting a FIT image.
3906 Enable building of TPL globally.
3909 Image offset to which the TPL should be padded before appending
3910 the TPL payload. By default, this is defined as
3911 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3912 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3913 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3918 [so far only for SMDK2400 boards]
3920 - Modem support enable:
3921 CONFIG_MODEM_SUPPORT
3923 - RTS/CTS Flow control enable:
3926 - Modem debug support:
3927 CONFIG_MODEM_SUPPORT_DEBUG
3929 Enables debugging stuff (char screen[1024], dbg())
3930 for modem support. Useful only with BDI2000.
3932 - Interrupt support (PPC):
3934 There are common interrupt_init() and timer_interrupt()
3935 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3936 for CPU specific initialization. interrupt_init_cpu()
3937 should set decrementer_count to appropriate value. If
3938 CPU resets decrementer automatically after interrupt
3939 (ppc4xx) it should set decrementer_count to zero.
3940 timer_interrupt() calls timer_interrupt_cpu() for CPU
3941 specific handling. If board has watchdog / status_led
3942 / other_activity_monitor it works automatically from
3943 general timer_interrupt().
3947 In the target system modem support is enabled when a
3948 specific key (key combination) is pressed during
3949 power-on. Otherwise U-Boot will boot normally
3950 (autoboot). The key_pressed() function is called from
3951 board_init(). Currently key_pressed() is a dummy
3952 function, returning 1 and thus enabling modem
3955 If there are no modem init strings in the
3956 environment, U-Boot proceed to autoboot; the
3957 previous output (banner, info printfs) will be
3960 See also: doc/README.Modem
3962 Board initialization settings:
3963 ------------------------------
3965 During Initialization u-boot calls a number of board specific functions
3966 to allow the preparation of board specific prerequisites, e.g. pin setup
3967 before drivers are initialized. To enable these callbacks the
3968 following configuration macros have to be defined. Currently this is
3969 architecture specific, so please check arch/your_architecture/lib/board.c
3970 typically in board_init_f() and board_init_r().
3972 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3973 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3974 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3975 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3977 Configuration Settings:
3978 -----------------------
3980 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3981 Optionally it can be defined to support 64-bit memory commands.
3983 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3984 undefine this when you're short of memory.
3986 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3987 width of the commands listed in the 'help' command output.
3989 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3990 prompt for user input.
3992 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3994 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3996 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3998 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3999 the application (usually a Linux kernel) when it is
4002 - CONFIG_SYS_BAUDRATE_TABLE:
4003 List of legal baudrate settings for this board.
4005 - CONFIG_SYS_CONSOLE_INFO_QUIET
4006 Suppress display of console information at boot.
4008 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4009 If the board specific function
4010 extern int overwrite_console (void);
4011 returns 1, the stdin, stderr and stdout are switched to the
4012 serial port, else the settings in the environment are used.
4014 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4015 Enable the call to overwrite_console().
4017 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4018 Enable overwrite of previous console environment settings.
4020 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4021 Begin and End addresses of the area used by the
4024 - CONFIG_SYS_ALT_MEMTEST:
4025 Enable an alternate, more extensive memory test.
4027 - CONFIG_SYS_MEMTEST_SCRATCH:
4028 Scratch address used by the alternate memory test
4029 You only need to set this if address zero isn't writeable
4031 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4032 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4033 this specified memory area will get subtracted from the top
4034 (end) of RAM and won't get "touched" at all by U-Boot. By
4035 fixing up gd->ram_size the Linux kernel should gets passed
4036 the now "corrected" memory size and won't touch it either.
4037 This should work for arch/ppc and arch/powerpc. Only Linux
4038 board ports in arch/powerpc with bootwrapper support that
4039 recalculate the memory size from the SDRAM controller setup
4040 will have to get fixed in Linux additionally.
4042 This option can be used as a workaround for the 440EPx/GRx
4043 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4046 WARNING: Please make sure that this value is a multiple of
4047 the Linux page size (normally 4k). If this is not the case,
4048 then the end address of the Linux memory will be located at a
4049 non page size aligned address and this could cause major
4052 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4053 Enable temporary baudrate change while serial download
4055 - CONFIG_SYS_SDRAM_BASE:
4056 Physical start address of SDRAM. _Must_ be 0 here.
4058 - CONFIG_SYS_MBIO_BASE:
4059 Physical start address of Motherboard I/O (if using a
4062 - CONFIG_SYS_FLASH_BASE:
4063 Physical start address of Flash memory.
4065 - CONFIG_SYS_MONITOR_BASE:
4066 Physical start address of boot monitor code (set by
4067 make config files to be same as the text base address
4068 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4069 CONFIG_SYS_FLASH_BASE when booting from flash.
4071 - CONFIG_SYS_MONITOR_LEN:
4072 Size of memory reserved for monitor code, used to
4073 determine _at_compile_time_ (!) if the environment is
4074 embedded within the U-Boot image, or in a separate
4077 - CONFIG_SYS_MALLOC_LEN:
4078 Size of DRAM reserved for malloc() use.
4080 - CONFIG_SYS_MALLOC_F_LEN
4081 Size of the malloc() pool for use before relocation. If
4082 this is defined, then a very simple malloc() implementation
4083 will become available before relocation. The address is just
4084 below the global data, and the stack is moved down to make
4087 This feature allocates regions with increasing addresses
4088 within the region. calloc() is supported, but realloc()
4089 is not available. free() is supported but does nothing.
4090 The memory will be freed (or in fact just forgotten) when
4091 U-Boot relocates itself.
4093 Pre-relocation malloc() is only supported on ARM and sandbox
4094 at present but is fairly easy to enable for other archs.
4096 - CONFIG_SYS_MALLOC_SIMPLE
4097 Provides a simple and small malloc() and calloc() for those
4098 boards which do not use the full malloc in SPL (which is
4099 enabled with CONFIG_SYS_SPL_MALLOC_START).
4101 - CONFIG_SYS_NONCACHED_MEMORY:
4102 Size of non-cached memory area. This area of memory will be
4103 typically located right below the malloc() area and mapped
4104 uncached in the MMU. This is useful for drivers that would
4105 otherwise require a lot of explicit cache maintenance. For
4106 some drivers it's also impossible to properly maintain the
4107 cache. For example if the regions that need to be flushed
4108 are not a multiple of the cache-line size, *and* padding
4109 cannot be allocated between the regions to align them (i.e.
4110 if the HW requires a contiguous array of regions, and the
4111 size of each region is not cache-aligned), then a flush of
4112 one region may result in overwriting data that hardware has
4113 written to another region in the same cache-line. This can
4114 happen for example in network drivers where descriptors for
4115 buffers are typically smaller than the CPU cache-line (e.g.
4116 16 bytes vs. 32 or 64 bytes).
4118 Non-cached memory is only supported on 32-bit ARM at present.
4120 - CONFIG_SYS_BOOTM_LEN:
4121 Normally compressed uImages are limited to an
4122 uncompressed size of 8 MBytes. If this is not enough,
4123 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4124 to adjust this setting to your needs.
4126 - CONFIG_SYS_BOOTMAPSZ:
4127 Maximum size of memory mapped by the startup code of
4128 the Linux kernel; all data that must be processed by
4129 the Linux kernel (bd_info, boot arguments, FDT blob if
4130 used) must be put below this limit, unless "bootm_low"
4131 environment variable is defined and non-zero. In such case
4132 all data for the Linux kernel must be between "bootm_low"
4133 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4134 variable "bootm_mapsize" will override the value of
4135 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4136 then the value in "bootm_size" will be used instead.
4138 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4139 Enable initrd_high functionality. If defined then the
4140 initrd_high feature is enabled and the bootm ramdisk subcommand
4143 - CONFIG_SYS_BOOT_GET_CMDLINE:
4144 Enables allocating and saving kernel cmdline in space between
4145 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4147 - CONFIG_SYS_BOOT_GET_KBD:
4148 Enables allocating and saving a kernel copy of the bd_info in
4149 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4151 - CONFIG_SYS_MAX_FLASH_BANKS:
4152 Max number of Flash memory banks
4154 - CONFIG_SYS_MAX_FLASH_SECT:
4155 Max number of sectors on a Flash chip
4157 - CONFIG_SYS_FLASH_ERASE_TOUT:
4158 Timeout for Flash erase operations (in ms)
4160 - CONFIG_SYS_FLASH_WRITE_TOUT:
4161 Timeout for Flash write operations (in ms)
4163 - CONFIG_SYS_FLASH_LOCK_TOUT
4164 Timeout for Flash set sector lock bit operation (in ms)
4166 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4167 Timeout for Flash clear lock bits operation (in ms)
4169 - CONFIG_SYS_FLASH_PROTECTION
4170 If defined, hardware flash sectors protection is used
4171 instead of U-Boot software protection.
4173 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4175 Enable TFTP transfers directly to flash memory;
4176 without this option such a download has to be
4177 performed in two steps: (1) download to RAM, and (2)
4178 copy from RAM to flash.
4180 The two-step approach is usually more reliable, since
4181 you can check if the download worked before you erase
4182 the flash, but in some situations (when system RAM is
4183 too limited to allow for a temporary copy of the
4184 downloaded image) this option may be very useful.
4186 - CONFIG_SYS_FLASH_CFI:
4187 Define if the flash driver uses extra elements in the
4188 common flash structure for storing flash geometry.
4190 - CONFIG_FLASH_CFI_DRIVER
4191 This option also enables the building of the cfi_flash driver
4192 in the drivers directory
4194 - CONFIG_FLASH_CFI_MTD
4195 This option enables the building of the cfi_mtd driver
4196 in the drivers directory. The driver exports CFI flash
4199 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4200 Use buffered writes to flash.
4202 - CONFIG_FLASH_SPANSION_S29WS_N
4203 s29ws-n MirrorBit flash has non-standard addresses for buffered
4206 - CONFIG_SYS_FLASH_QUIET_TEST
4207 If this option is defined, the common CFI flash doesn't
4208 print it's warning upon not recognized FLASH banks. This
4209 is useful, if some of the configured banks are only
4210 optionally available.
4212 - CONFIG_FLASH_SHOW_PROGRESS
4213 If defined (must be an integer), print out countdown
4214 digits and dots. Recommended value: 45 (9..1) for 80
4215 column displays, 15 (3..1) for 40 column displays.
4217 - CONFIG_FLASH_VERIFY
4218 If defined, the content of the flash (destination) is compared
4219 against the source after the write operation. An error message
4220 will be printed when the contents are not identical.
4221 Please note that this option is useless in nearly all cases,
4222 since such flash programming errors usually are detected earlier
4223 while unprotecting/erasing/programming. Please only enable
4224 this option if you really know what you are doing.
4226 - CONFIG_SYS_RX_ETH_BUFFER:
4227 Defines the number of Ethernet receive buffers. On some
4228 Ethernet controllers it is recommended to set this value
4229 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4230 buffers can be full shortly after enabling the interface
4231 on high Ethernet traffic.
4232 Defaults to 4 if not defined.
4234 - CONFIG_ENV_MAX_ENTRIES
4236 Maximum number of entries in the hash table that is used
4237 internally to store the environment settings. The default
4238 setting is supposed to be generous and should work in most
4239 cases. This setting can be used to tune behaviour; see
4240 lib/hashtable.c for details.
4242 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4243 - CONFIG_ENV_FLAGS_LIST_STATIC
4244 Enable validation of the values given to environment variables when
4245 calling env set. Variables can be restricted to only decimal,
4246 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4247 the variables can also be restricted to IP address or MAC address.
4249 The format of the list is:
4250 type_attribute = [s|d|x|b|i|m]
4251 access_attribute = [a|r|o|c]
4252 attributes = type_attribute[access_attribute]
4253 entry = variable_name[:attributes]
4256 The type attributes are:
4257 s - String (default)
4260 b - Boolean ([1yYtT|0nNfF])
4264 The access attributes are:
4270 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4271 Define this to a list (string) to define the ".flags"
4272 environment variable in the default or embedded environment.
4274 - CONFIG_ENV_FLAGS_LIST_STATIC
4275 Define this to a list (string) to define validation that
4276 should be done if an entry is not found in the ".flags"
4277 environment variable. To override a setting in the static
4278 list, simply add an entry for the same variable name to the
4281 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4282 If defined, don't allow the -f switch to env set override variable
4285 - CONFIG_SYS_GENERIC_BOARD
4286 This selects the architecture-generic board system instead of the
4287 architecture-specific board files. It is intended to move boards
4288 to this new framework over time. Defining this will disable the
4289 arch/foo/lib/board.c file and use common/board_f.c and
4290 common/board_r.c instead. To use this option your architecture
4291 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4292 If you find problems enabling this option on your board please report
4293 the problem and send patches!
4295 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4296 This is set by OMAP boards for the max time that reset should
4297 be asserted. See doc/README.omap-reset-time for details on how
4298 the value can be calculated on a given board.
4301 If stdint.h is available with your toolchain you can define this
4302 option to enable it. You can provide option 'USE_STDINT=1' when
4303 building U-Boot to enable this.
4305 The following definitions that deal with the placement and management
4306 of environment data (variable area); in general, we support the
4307 following configurations:
4309 - CONFIG_BUILD_ENVCRC:
4311 Builds up envcrc with the target environment so that external utils
4312 may easily extract it and embed it in final U-Boot images.
4314 - CONFIG_ENV_IS_IN_FLASH:
4316 Define this if the environment is in flash memory.
4318 a) The environment occupies one whole flash sector, which is
4319 "embedded" in the text segment with the U-Boot code. This
4320 happens usually with "bottom boot sector" or "top boot
4321 sector" type flash chips, which have several smaller
4322 sectors at the start or the end. For instance, such a
4323 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4324 such a case you would place the environment in one of the
4325 4 kB sectors - with U-Boot code before and after it. With
4326 "top boot sector" type flash chips, you would put the
4327 environment in one of the last sectors, leaving a gap
4328 between U-Boot and the environment.
4330 - CONFIG_ENV_OFFSET:
4332 Offset of environment data (variable area) to the
4333 beginning of flash memory; for instance, with bottom boot
4334 type flash chips the second sector can be used: the offset
4335 for this sector is given here.
4337 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4341 This is just another way to specify the start address of
4342 the flash sector containing the environment (instead of
4345 - CONFIG_ENV_SECT_SIZE:
4347 Size of the sector containing the environment.
4350 b) Sometimes flash chips have few, equal sized, BIG sectors.
4351 In such a case you don't want to spend a whole sector for
4356 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4357 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4358 of this flash sector for the environment. This saves
4359 memory for the RAM copy of the environment.
4361 It may also save flash memory if you decide to use this
4362 when your environment is "embedded" within U-Boot code,
4363 since then the remainder of the flash sector could be used
4364 for U-Boot code. It should be pointed out that this is
4365 STRONGLY DISCOURAGED from a robustness point of view:
4366 updating the environment in flash makes it always
4367 necessary to erase the WHOLE sector. If something goes
4368 wrong before the contents has been restored from a copy in
4369 RAM, your target system will be dead.
4371 - CONFIG_ENV_ADDR_REDUND
4372 CONFIG_ENV_SIZE_REDUND
4374 These settings describe a second storage area used to hold
4375 a redundant copy of the environment data, so that there is
4376 a valid backup copy in case there is a power failure during
4377 a "saveenv" operation.
4379 BE CAREFUL! Any changes to the flash layout, and some changes to the
4380 source code will make it necessary to adapt <board>/u-boot.lds*
4384 - CONFIG_ENV_IS_IN_NVRAM:
4386 Define this if you have some non-volatile memory device
4387 (NVRAM, battery buffered SRAM) which you want to use for the
4393 These two #defines are used to determine the memory area you
4394 want to use for environment. It is assumed that this memory
4395 can just be read and written to, without any special
4398 BE CAREFUL! The first access to the environment happens quite early
4399 in U-Boot initialization (when we try to get the setting of for the
4400 console baudrate). You *MUST* have mapped your NVRAM area then, or
4403 Please note that even with NVRAM we still use a copy of the
4404 environment in RAM: we could work on NVRAM directly, but we want to
4405 keep settings there always unmodified except somebody uses "saveenv"
4406 to save the current settings.
4409 - CONFIG_ENV_IS_IN_EEPROM:
4411 Use this if you have an EEPROM or similar serial access
4412 device and a driver for it.
4414 - CONFIG_ENV_OFFSET:
4417 These two #defines specify the offset and size of the
4418 environment area within the total memory of your EEPROM.
4420 - CONFIG_SYS_I2C_EEPROM_ADDR:
4421 If defined, specified the chip address of the EEPROM device.
4422 The default address is zero.
4424 - CONFIG_SYS_I2C_EEPROM_BUS:
4425 If defined, specified the i2c bus of the EEPROM device.
4427 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4428 If defined, the number of bits used to address bytes in a
4429 single page in the EEPROM device. A 64 byte page, for example
4430 would require six bits.
4432 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4433 If defined, the number of milliseconds to delay between
4434 page writes. The default is zero milliseconds.
4436 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4437 The length in bytes of the EEPROM memory array address. Note
4438 that this is NOT the chip address length!
4440 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4441 EEPROM chips that implement "address overflow" are ones
4442 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4443 address and the extra bits end up in the "chip address" bit
4444 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4447 Note that we consider the length of the address field to
4448 still be one byte because the extra address bits are hidden
4449 in the chip address.
4451 - CONFIG_SYS_EEPROM_SIZE:
4452 The size in bytes of the EEPROM device.
4454 - CONFIG_ENV_EEPROM_IS_ON_I2C
4455 define this, if you have I2C and SPI activated, and your
4456 EEPROM, which holds the environment, is on the I2C bus.
4458 - CONFIG_I2C_ENV_EEPROM_BUS
4459 if you have an Environment on an EEPROM reached over
4460 I2C muxes, you can define here, how to reach this
4461 EEPROM. For example:
4463 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4465 EEPROM which holds the environment, is reached over
4466 a pca9547 i2c mux with address 0x70, channel 3.
4468 - CONFIG_ENV_IS_IN_DATAFLASH:
4470 Define this if you have a DataFlash memory device which you
4471 want to use for the environment.
4473 - CONFIG_ENV_OFFSET:
4477 These three #defines specify the offset and size of the
4478 environment area within the total memory of your DataFlash placed
4479 at the specified address.
4481 - CONFIG_ENV_IS_IN_SPI_FLASH:
4483 Define this if you have a SPI Flash memory device which you
4484 want to use for the environment.
4486 - CONFIG_ENV_OFFSET:
4489 These two #defines specify the offset and size of the
4490 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4491 aligned to an erase sector boundary.
4493 - CONFIG_ENV_SECT_SIZE:
4495 Define the SPI flash's sector size.
4497 - CONFIG_ENV_OFFSET_REDUND (optional):
4499 This setting describes a second storage area of CONFIG_ENV_SIZE
4500 size used to hold a redundant copy of the environment data, so
4501 that there is a valid backup copy in case there is a power failure
4502 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4503 aligned to an erase sector boundary.
4505 - CONFIG_ENV_SPI_BUS (optional):
4506 - CONFIG_ENV_SPI_CS (optional):
4508 Define the SPI bus and chip select. If not defined they will be 0.
4510 - CONFIG_ENV_SPI_MAX_HZ (optional):
4512 Define the SPI max work clock. If not defined then use 1MHz.
4514 - CONFIG_ENV_SPI_MODE (optional):
4516 Define the SPI work mode. If not defined then use SPI_MODE_3.
4518 - CONFIG_ENV_IS_IN_REMOTE:
4520 Define this if you have a remote memory space which you
4521 want to use for the local device's environment.
4526 These two #defines specify the address and size of the
4527 environment area within the remote memory space. The
4528 local device can get the environment from remote memory
4529 space by SRIO or PCIE links.
4531 BE CAREFUL! For some special cases, the local device can not use
4532 "saveenv" command. For example, the local device will get the
4533 environment stored in a remote NOR flash by SRIO or PCIE link,
4534 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4536 - CONFIG_ENV_IS_IN_NAND:
4538 Define this if you have a NAND device which you want to use
4539 for the environment.
4541 - CONFIG_ENV_OFFSET:
4544 These two #defines specify the offset and size of the environment
4545 area within the first NAND device. CONFIG_ENV_OFFSET must be
4546 aligned to an erase block boundary.
4548 - CONFIG_ENV_OFFSET_REDUND (optional):
4550 This setting describes a second storage area of CONFIG_ENV_SIZE
4551 size used to hold a redundant copy of the environment data, so
4552 that there is a valid backup copy in case there is a power failure
4553 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4554 aligned to an erase block boundary.
4556 - CONFIG_ENV_RANGE (optional):
4558 Specifies the length of the region in which the environment
4559 can be written. This should be a multiple of the NAND device's
4560 block size. Specifying a range with more erase blocks than
4561 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4562 the range to be avoided.
4564 - CONFIG_ENV_OFFSET_OOB (optional):
4566 Enables support for dynamically retrieving the offset of the
4567 environment from block zero's out-of-band data. The
4568 "nand env.oob" command can be used to record this offset.
4569 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4570 using CONFIG_ENV_OFFSET_OOB.
4572 - CONFIG_NAND_ENV_DST
4574 Defines address in RAM to which the nand_spl code should copy the
4575 environment. If redundant environment is used, it will be copied to
4576 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4578 - CONFIG_ENV_IS_IN_UBI:
4580 Define this if you have an UBI volume that you want to use for the
4581 environment. This has the benefit of wear-leveling the environment
4582 accesses, which is important on NAND.
4584 - CONFIG_ENV_UBI_PART:
4586 Define this to a string that is the mtd partition containing the UBI.
4588 - CONFIG_ENV_UBI_VOLUME:
4590 Define this to the name of the volume that you want to store the
4593 - CONFIG_ENV_UBI_VOLUME_REDUND:
4595 Define this to the name of another volume to store a second copy of
4596 the environment in. This will enable redundant environments in UBI.
4597 It is assumed that both volumes are in the same MTD partition.
4599 - CONFIG_UBI_SILENCE_MSG
4600 - CONFIG_UBIFS_SILENCE_MSG
4602 You will probably want to define these to avoid a really noisy system
4603 when storing the env in UBI.
4605 - CONFIG_ENV_IS_IN_FAT:
4606 Define this if you want to use the FAT file system for the environment.
4608 - FAT_ENV_INTERFACE:
4610 Define this to a string that is the name of the block device.
4612 - FAT_ENV_DEV_AND_PART:
4614 Define this to a string to specify the partition of the device. It can
4617 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4618 - "D:P": device D partition P. Error occurs if device D has no
4621 - "D" or "D:": device D partition 1 if device D has partition
4622 table, or the whole device D if has no partition
4624 - "D:auto": first partition in device D with bootable flag set.
4625 If none, first valid partition in device D. If no
4626 partition table then means device D.
4630 It's a string of the FAT file name. This file use to store the
4634 This should be defined. Otherwise it cannot save the environment file.
4636 - CONFIG_ENV_IS_IN_MMC:
4638 Define this if you have an MMC device which you want to use for the
4641 - CONFIG_SYS_MMC_ENV_DEV:
4643 Specifies which MMC device the environment is stored in.
4645 - CONFIG_SYS_MMC_ENV_PART (optional):
4647 Specifies which MMC partition the environment is stored in. If not
4648 set, defaults to partition 0, the user area. Common values might be
4649 1 (first MMC boot partition), 2 (second MMC boot partition).
4651 - CONFIG_ENV_OFFSET:
4654 These two #defines specify the offset and size of the environment
4655 area within the specified MMC device.
4657 If offset is positive (the usual case), it is treated as relative to
4658 the start of the MMC partition. If offset is negative, it is treated
4659 as relative to the end of the MMC partition. This can be useful if
4660 your board may be fitted with different MMC devices, which have
4661 different sizes for the MMC partitions, and you always want the
4662 environment placed at the very end of the partition, to leave the
4663 maximum possible space before it, to store other data.
4665 These two values are in units of bytes, but must be aligned to an
4666 MMC sector boundary.
4668 - CONFIG_ENV_OFFSET_REDUND (optional):
4670 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4671 hold a redundant copy of the environment data. This provides a
4672 valid backup copy in case the other copy is corrupted, e.g. due
4673 to a power failure during a "saveenv" operation.
4675 This value may also be positive or negative; this is handled in the
4676 same way as CONFIG_ENV_OFFSET.
4678 This value is also in units of bytes, but must also be aligned to
4679 an MMC sector boundary.
4681 - CONFIG_ENV_SIZE_REDUND (optional):
4683 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4684 set. If this value is set, it must be set to the same value as
4687 - CONFIG_SYS_SPI_INIT_OFFSET
4689 Defines offset to the initial SPI buffer area in DPRAM. The
4690 area is used at an early stage (ROM part) if the environment
4691 is configured to reside in the SPI EEPROM: We need a 520 byte
4692 scratch DPRAM area. It is used between the two initialization
4693 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4694 to be a good choice since it makes it far enough from the
4695 start of the data area as well as from the stack pointer.
4697 Please note that the environment is read-only until the monitor
4698 has been relocated to RAM and a RAM copy of the environment has been
4699 created; also, when using EEPROM you will have to use getenv_f()
4700 until then to read environment variables.
4702 The environment is protected by a CRC32 checksum. Before the monitor
4703 is relocated into RAM, as a result of a bad CRC you will be working
4704 with the compiled-in default environment - *silently*!!! [This is
4705 necessary, because the first environment variable we need is the
4706 "baudrate" setting for the console - if we have a bad CRC, we don't
4707 have any device yet where we could complain.]
4709 Note: once the monitor has been relocated, then it will complain if
4710 the default environment is used; a new CRC is computed as soon as you
4711 use the "saveenv" command to store a valid environment.
4713 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4714 Echo the inverted Ethernet link state to the fault LED.
4716 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4717 also needs to be defined.
4719 - CONFIG_SYS_FAULT_MII_ADDR:
4720 MII address of the PHY to check for the Ethernet link state.
4722 - CONFIG_NS16550_MIN_FUNCTIONS:
4723 Define this if you desire to only have use of the NS16550_init
4724 and NS16550_putc functions for the serial driver located at
4725 drivers/serial/ns16550.c. This option is useful for saving
4726 space for already greatly restricted images, including but not
4727 limited to NAND_SPL configurations.
4729 - CONFIG_DISPLAY_BOARDINFO
4730 Display information about the board that U-Boot is running on
4731 when U-Boot starts up. The board function checkboard() is called
4734 - CONFIG_DISPLAY_BOARDINFO_LATE
4735 Similar to the previous option, but display this information
4736 later, once stdio is running and output goes to the LCD, if
4739 - CONFIG_BOARD_SIZE_LIMIT:
4740 Maximum size of the U-Boot image. When defined, the
4741 build system checks that the actual size does not
4744 Low Level (hardware related) configuration options:
4745 ---------------------------------------------------
4747 - CONFIG_SYS_CACHELINE_SIZE:
4748 Cache Line Size of the CPU.
4750 - CONFIG_SYS_DEFAULT_IMMR:
4751 Default address of the IMMR after system reset.
4753 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4754 and RPXsuper) to be able to adjust the position of
4755 the IMMR register after a reset.
4757 - CONFIG_SYS_CCSRBAR_DEFAULT:
4758 Default (power-on reset) physical address of CCSR on Freescale
4761 - CONFIG_SYS_CCSRBAR:
4762 Virtual address of CCSR. On a 32-bit build, this is typically
4763 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4765 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4766 for cross-platform code that uses that macro instead.
4768 - CONFIG_SYS_CCSRBAR_PHYS:
4769 Physical address of CCSR. CCSR can be relocated to a new
4770 physical address, if desired. In this case, this macro should
4771 be set to that address. Otherwise, it should be set to the
4772 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4773 is typically relocated on 36-bit builds. It is recommended
4774 that this macro be defined via the _HIGH and _LOW macros:
4776 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4777 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4779 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4780 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4781 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4782 used in assembly code, so it must not contain typecasts or
4783 integer size suffixes (e.g. "ULL").
4785 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4786 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4787 used in assembly code, so it must not contain typecasts or
4788 integer size suffixes (e.g. "ULL").
4790 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4791 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4792 forced to a value that ensures that CCSR is not relocated.
4794 - Floppy Disk Support:
4795 CONFIG_SYS_FDC_DRIVE_NUMBER
4797 the default drive number (default value 0)
4799 CONFIG_SYS_ISA_IO_STRIDE
4801 defines the spacing between FDC chipset registers
4804 CONFIG_SYS_ISA_IO_OFFSET
4806 defines the offset of register from address. It
4807 depends on which part of the data bus is connected to
4808 the FDC chipset. (default value 0)
4810 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4811 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4814 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4815 fdc_hw_init() is called at the beginning of the FDC
4816 setup. fdc_hw_init() must be provided by the board
4817 source code. It is used to make hardware-dependent
4821 Most IDE controllers were designed to be connected with PCI
4822 interface. Only few of them were designed for AHB interface.
4823 When software is doing ATA command and data transfer to
4824 IDE devices through IDE-AHB controller, some additional
4825 registers accessing to these kind of IDE-AHB controller
4828 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4829 DO NOT CHANGE unless you know exactly what you're
4830 doing! (11-4) [MPC8xx/82xx systems only]
4832 - CONFIG_SYS_INIT_RAM_ADDR:
4834 Start address of memory area that can be used for
4835 initial data and stack; please note that this must be
4836 writable memory that is working WITHOUT special
4837 initialization, i. e. you CANNOT use normal RAM which
4838 will become available only after programming the
4839 memory controller and running certain initialization
4842 U-Boot uses the following memory types:
4843 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4844 - MPC824X: data cache
4845 - PPC4xx: data cache
4847 - CONFIG_SYS_GBL_DATA_OFFSET:
4849 Offset of the initial data structure in the memory
4850 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4851 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4852 data is located at the end of the available space
4853 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4854 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4855 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4856 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4859 On the MPC824X (or other systems that use the data
4860 cache for initial memory) the address chosen for
4861 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4862 point to an otherwise UNUSED address space between
4863 the top of RAM and the start of the PCI space.
4865 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4867 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4869 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4871 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4873 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4875 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4877 - CONFIG_SYS_OR_TIMING_SDRAM:
4880 - CONFIG_SYS_MAMR_PTA:
4881 periodic timer for refresh
4883 - CONFIG_SYS_DER: Debug Event Register (37-47)
4885 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4886 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4887 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4888 CONFIG_SYS_BR1_PRELIM:
4889 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4891 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4892 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4893 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4894 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4896 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4897 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4898 Machine Mode Register and Memory Periodic Timer
4899 Prescaler definitions (SDRAM timing)
4901 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4902 enable I2C microcode relocation patch (MPC8xx);
4903 define relocation offset in DPRAM [DSP2]
4905 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4906 enable SMC microcode relocation patch (MPC8xx);
4907 define relocation offset in DPRAM [SMC1]
4909 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4910 enable SPI microcode relocation patch (MPC8xx);
4911 define relocation offset in DPRAM [SCC4]
4913 - CONFIG_SYS_USE_OSCCLK:
4914 Use OSCM clock mode on MBX8xx board. Be careful,
4915 wrong setting might damage your board. Read
4916 doc/README.MBX before setting this variable!
4918 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4919 Offset of the bootmode word in DPRAM used by post
4920 (Power On Self Tests). This definition overrides
4921 #define'd default value in commproc.h resp.
4924 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4925 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4926 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4927 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4928 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4929 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4930 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4931 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4932 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4934 - CONFIG_PCI_DISABLE_PCIE:
4935 Disable PCI-Express on systems where it is supported but not
4938 - CONFIG_PCI_ENUM_ONLY
4939 Only scan through and get the devices on the buses.
4940 Don't do any setup work, presumably because someone or
4941 something has already done it, and we don't need to do it
4942 a second time. Useful for platforms that are pre-booted
4943 by coreboot or similar.
4945 - CONFIG_PCI_INDIRECT_BRIDGE:
4946 Enable support for indirect PCI bridges.
4949 Chip has SRIO or not
4952 Board has SRIO 1 port available
4955 Board has SRIO 2 port available
4957 - CONFIG_SRIO_PCIE_BOOT_MASTER
4958 Board can support master function for Boot from SRIO and PCIE
4960 - CONFIG_SYS_SRIOn_MEM_VIRT:
4961 Virtual Address of SRIO port 'n' memory region
4963 - CONFIG_SYS_SRIOn_MEM_PHYS:
4964 Physical Address of SRIO port 'n' memory region
4966 - CONFIG_SYS_SRIOn_MEM_SIZE:
4967 Size of SRIO port 'n' memory region
4969 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4970 Defined to tell the NAND controller that the NAND chip is using
4972 Not all NAND drivers use this symbol.
4973 Example of drivers that use it:
4974 - drivers/mtd/nand/ndfc.c
4975 - drivers/mtd/nand/mxc_nand.c
4977 - CONFIG_SYS_NDFC_EBC0_CFG
4978 Sets the EBC0_CFG register for the NDFC. If not defined
4979 a default value will be used.
4982 Get DDR timing information from an I2C EEPROM. Common
4983 with pluggable memory modules such as SODIMMs
4986 I2C address of the SPD EEPROM
4988 - CONFIG_SYS_SPD_BUS_NUM
4989 If SPD EEPROM is on an I2C bus other than the first
4990 one, specify here. Note that the value must resolve
4991 to something your driver can deal with.
4993 - CONFIG_SYS_DDR_RAW_TIMING
4994 Get DDR timing information from other than SPD. Common with
4995 soldered DDR chips onboard without SPD. DDR raw timing
4996 parameters are extracted from datasheet and hard-coded into
4997 header files or board specific files.
4999 - CONFIG_FSL_DDR_INTERACTIVE
5000 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5002 - CONFIG_FSL_DDR_SYNC_REFRESH
5003 Enable sync of refresh for multiple controllers.
5005 - CONFIG_FSL_DDR_BIST
5006 Enable built-in memory test for Freescale DDR controllers.
5008 - CONFIG_SYS_83XX_DDR_USES_CS0
5009 Only for 83xx systems. If specified, then DDR should
5010 be configured using CS0 and CS1 instead of CS2 and CS3.
5012 - CONFIG_ETHER_ON_FEC[12]
5013 Define to enable FEC[12] on a 8xx series processor.
5015 - CONFIG_FEC[12]_PHY
5016 Define to the hardcoded PHY address which corresponds
5017 to the given FEC; i. e.
5018 #define CONFIG_FEC1_PHY 4
5019 means that the PHY with address 4 is connected to FEC1
5021 When set to -1, means to probe for first available.
5023 - CONFIG_FEC[12]_PHY_NORXERR
5024 The PHY does not have a RXERR line (RMII only).
5025 (so program the FEC to ignore it).
5028 Enable RMII mode for all FECs.
5029 Note that this is a global option, we can't
5030 have one FEC in standard MII mode and another in RMII mode.
5032 - CONFIG_CRC32_VERIFY
5033 Add a verify option to the crc32 command.
5036 => crc32 -v <address> <count> <crc32>
5038 Where address/count indicate a memory area
5039 and crc32 is the correct crc32 which the
5043 Add the "loopw" memory command. This only takes effect if
5044 the memory commands are activated globally (CONFIG_CMD_MEM).
5047 Add the "mdc" and "mwc" memory commands. These are cyclic
5052 This command will print 4 bytes (10,11,12,13) each 500 ms.
5054 => mwc.l 100 12345678 10
5055 This command will write 12345678 to address 100 all 10 ms.
5057 This only takes effect if the memory commands are activated
5058 globally (CONFIG_CMD_MEM).
5060 - CONFIG_SKIP_LOWLEVEL_INIT
5061 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5062 low level initializations (like setting up the memory
5063 controller) are omitted and/or U-Boot does not
5064 relocate itself into RAM.
5066 Normally this variable MUST NOT be defined. The only
5067 exception is when U-Boot is loaded (to RAM) by some
5068 other boot loader or by a debugger which performs
5069 these initializations itself.
5072 Modifies the behaviour of start.S when compiling a loader
5073 that is executed before the actual U-Boot. E.g. when
5074 compiling a NAND SPL.
5077 Modifies the behaviour of start.S when compiling a loader
5078 that is executed after the SPL and before the actual U-Boot.
5079 It is loaded by the SPL.
5081 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5082 Only for 85xx systems. If this variable is specified, the section
5083 .resetvec is not kept and the section .bootpg is placed in the
5084 previous 4k of the .text section.
5086 - CONFIG_ARCH_MAP_SYSMEM
5087 Generally U-Boot (and in particular the md command) uses
5088 effective address. It is therefore not necessary to regard
5089 U-Boot address as virtual addresses that need to be translated
5090 to physical addresses. However, sandbox requires this, since
5091 it maintains its own little RAM buffer which contains all
5092 addressable memory. This option causes some memory accesses
5093 to be mapped through map_sysmem() / unmap_sysmem().
5095 - CONFIG_USE_ARCH_MEMCPY
5096 CONFIG_USE_ARCH_MEMSET
5097 If these options are used a optimized version of memcpy/memset will
5098 be used if available. These functions may be faster under some
5099 conditions but may increase the binary size.
5101 - CONFIG_X86_RESET_VECTOR
5102 If defined, the x86 reset vector code is included. This is not
5103 needed when U-Boot is running from Coreboot.
5106 Defines the MPU clock speed (in MHz).
5108 NOTE : currently only supported on AM335x platforms.
5110 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5111 Enables the RTC32K OSC on AM33xx based plattforms
5113 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5114 Option to disable subpage write in NAND driver
5115 driver that uses this:
5116 drivers/mtd/nand/davinci_nand.c
5118 Freescale QE/FMAN Firmware Support:
5119 -----------------------------------
5121 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5122 loading of "firmware", which is encoded in the QE firmware binary format.
5123 This firmware often needs to be loaded during U-Boot booting, so macros
5124 are used to identify the storage device (NOR flash, SPI, etc) and the address
5127 - CONFIG_SYS_FMAN_FW_ADDR
5128 The address in the storage device where the FMAN microcode is located. The
5129 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5132 - CONFIG_SYS_QE_FW_ADDR
5133 The address in the storage device where the QE microcode is located. The
5134 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5137 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5138 The maximum possible size of the firmware. The firmware binary format
5139 has a field that specifies the actual size of the firmware, but it
5140 might not be possible to read any part of the firmware unless some
5141 local storage is allocated to hold the entire firmware first.
5143 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5144 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5145 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5146 virtual address in NOR flash.
5148 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5149 Specifies that QE/FMAN firmware is located in NAND flash.
5150 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5152 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5153 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5154 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5156 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5157 Specifies that QE/FMAN firmware is located on the primary SPI
5158 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5160 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5161 Specifies that QE/FMAN firmware is located in the remote (master)
5162 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5163 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5164 window->master inbound window->master LAW->the ucode address in
5165 master's memory space.
5167 Freescale Layerscape Management Complex Firmware Support:
5168 ---------------------------------------------------------
5169 The Freescale Layerscape Management Complex (MC) supports the loading of
5171 This firmware often needs to be loaded during U-Boot booting, so macros
5172 are used to identify the storage device (NOR flash, SPI, etc) and the address
5175 - CONFIG_FSL_MC_ENET
5176 Enable the MC driver for Layerscape SoCs.
5178 - CONFIG_SYS_LS_MC_FW_ADDR
5179 The address in the storage device where the firmware is located. The
5180 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5183 - CONFIG_SYS_LS_MC_FW_LENGTH
5184 The maximum possible size of the firmware. The firmware binary format
5185 has a field that specifies the actual size of the firmware, but it
5186 might not be possible to read any part of the firmware unless some
5187 local storage is allocated to hold the entire firmware first.
5189 - CONFIG_SYS_LS_MC_FW_IN_NOR
5190 Specifies that MC firmware is located in NOR flash, mapped as
5191 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5192 virtual address in NOR flash.
5194 Building the Software:
5195 ======================
5197 Building U-Boot has been tested in several native build environments
5198 and in many different cross environments. Of course we cannot support
5199 all possibly existing versions of cross development tools in all
5200 (potentially obsolete) versions. In case of tool chain problems we
5201 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5202 which is extensively used to build and test U-Boot.
5204 If you are not using a native environment, it is assumed that you
5205 have GNU cross compiling tools available in your path. In this case,
5206 you must set the environment variable CROSS_COMPILE in your shell.
5207 Note that no changes to the Makefile or any other source files are
5208 necessary. For example using the ELDK on a 4xx CPU, please enter:
5210 $ CROSS_COMPILE=ppc_4xx-
5211 $ export CROSS_COMPILE
5213 Note: If you wish to generate Windows versions of the utilities in
5214 the tools directory you can use the MinGW toolchain
5215 (http://www.mingw.org). Set your HOST tools to the MinGW
5216 toolchain and execute 'make tools'. For example:
5218 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5220 Binaries such as tools/mkimage.exe will be created which can
5221 be executed on computers running Windows.
5223 U-Boot is intended to be simple to build. After installing the
5224 sources you must configure U-Boot for one specific board type. This
5229 where "NAME_defconfig" is the name of one of the existing configu-
5230 rations; see boards.cfg for supported names.
5232 Note: for some board special configuration names may exist; check if
5233 additional information is available from the board vendor; for
5234 instance, the TQM823L systems are available without (standard)
5235 or with LCD support. You can select such additional "features"
5236 when choosing the configuration, i. e.
5238 make TQM823L_defconfig
5239 - will configure for a plain TQM823L, i. e. no LCD support
5241 make TQM823L_LCD_defconfig
5242 - will configure for a TQM823L with U-Boot console on LCD
5247 Finally, type "make all", and you should get some working U-Boot
5248 images ready for download to / installation on your system:
5250 - "u-boot.bin" is a raw binary image
5251 - "u-boot" is an image in ELF binary format
5252 - "u-boot.srec" is in Motorola S-Record format
5254 By default the build is performed locally and the objects are saved
5255 in the source directory. One of the two methods can be used to change
5256 this behavior and build U-Boot to some external directory:
5258 1. Add O= to the make command line invocations:
5260 make O=/tmp/build distclean
5261 make O=/tmp/build NAME_defconfig
5262 make O=/tmp/build all
5264 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5266 export KBUILD_OUTPUT=/tmp/build
5271 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5275 Please be aware that the Makefiles assume you are using GNU make, so
5276 for instance on NetBSD you might need to use "gmake" instead of
5280 If the system board that you have is not listed, then you will need
5281 to port U-Boot to your hardware platform. To do this, follow these
5284 1. Add a new configuration option for your board to the toplevel
5285 "boards.cfg" file, using the existing entries as examples.
5286 Follow the instructions there to keep the boards in order.
5287 2. Create a new directory to hold your board specific code. Add any
5288 files you need. In your board directory, you will need at least
5289 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5290 3. Create a new configuration file "include/configs/<board>.h" for
5292 3. If you're porting U-Boot to a new CPU, then also create a new
5293 directory to hold your CPU specific code. Add any files you need.
5294 4. Run "make <board>_defconfig" with your new name.
5295 5. Type "make", and you should get a working "u-boot.srec" file
5296 to be installed on your target system.
5297 6. Debug and solve any problems that might arise.
5298 [Of course, this last step is much harder than it sounds.]
5301 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5302 ==============================================================
5304 If you have modified U-Boot sources (for instance added a new board
5305 or support for new devices, a new CPU, etc.) you are expected to
5306 provide feedback to the other developers. The feedback normally takes
5307 the form of a "patch", i. e. a context diff against a certain (latest
5308 official or latest in the git repository) version of U-Boot sources.
5310 But before you submit such a patch, please verify that your modifi-
5311 cation did not break existing code. At least make sure that *ALL* of
5312 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5313 just run the "MAKEALL" script, which will configure and build U-Boot
5314 for ALL supported system. Be warned, this will take a while. You can
5315 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5316 environment variable to the script, i. e. to use the ELDK cross tools
5319 CROSS_COMPILE=ppc_8xx- MAKEALL
5321 or to build on a native PowerPC system you can type
5323 CROSS_COMPILE=' ' MAKEALL
5325 When using the MAKEALL script, the default behaviour is to build
5326 U-Boot in the source directory. This location can be changed by
5327 setting the BUILD_DIR environment variable. Also, for each target
5328 built, the MAKEALL script saves two log files (<target>.ERR and
5329 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5330 location can be changed by setting the MAKEALL_LOGDIR environment
5331 variable. For example:
5333 export BUILD_DIR=/tmp/build
5334 export MAKEALL_LOGDIR=/tmp/log
5335 CROSS_COMPILE=ppc_8xx- MAKEALL
5337 With the above settings build objects are saved in the /tmp/build,
5338 log files are saved in the /tmp/log and the source tree remains clean
5339 during the whole build process.
5342 See also "U-Boot Porting Guide" below.
5345 Monitor Commands - Overview:
5346 ============================
5348 go - start application at address 'addr'
5349 run - run commands in an environment variable
5350 bootm - boot application image from memory
5351 bootp - boot image via network using BootP/TFTP protocol
5352 bootz - boot zImage from memory
5353 tftpboot- boot image via network using TFTP protocol
5354 and env variables "ipaddr" and "serverip"
5355 (and eventually "gatewayip")
5356 tftpput - upload a file via network using TFTP protocol
5357 rarpboot- boot image via network using RARP/TFTP protocol
5358 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5359 loads - load S-Record file over serial line
5360 loadb - load binary file over serial line (kermit mode)
5362 mm - memory modify (auto-incrementing)
5363 nm - memory modify (constant address)
5364 mw - memory write (fill)
5366 cmp - memory compare
5367 crc32 - checksum calculation
5368 i2c - I2C sub-system
5369 sspi - SPI utility commands
5370 base - print or set address offset
5371 printenv- print environment variables
5372 setenv - set environment variables
5373 saveenv - save environment variables to persistent storage
5374 protect - enable or disable FLASH write protection
5375 erase - erase FLASH memory
5376 flinfo - print FLASH memory information
5377 nand - NAND memory operations (see doc/README.nand)
5378 bdinfo - print Board Info structure
5379 iminfo - print header information for application image
5380 coninfo - print console devices and informations
5381 ide - IDE sub-system
5382 loop - infinite loop on address range
5383 loopw - infinite write loop on address range
5384 mtest - simple RAM test
5385 icache - enable or disable instruction cache
5386 dcache - enable or disable data cache
5387 reset - Perform RESET of the CPU
5388 echo - echo args to console
5389 version - print monitor version
5390 help - print online help
5391 ? - alias for 'help'
5394 Monitor Commands - Detailed Description:
5395 ========================================
5399 For now: just type "help <command>".
5402 Environment Variables:
5403 ======================
5405 U-Boot supports user configuration using Environment Variables which
5406 can be made persistent by saving to Flash memory.
5408 Environment Variables are set using "setenv", printed using
5409 "printenv", and saved to Flash using "saveenv". Using "setenv"
5410 without a value can be used to delete a variable from the
5411 environment. As long as you don't save the environment you are
5412 working with an in-memory copy. In case the Flash area containing the
5413 environment is erased by accident, a default environment is provided.
5415 Some configuration options can be set using Environment Variables.
5417 List of environment variables (most likely not complete):
5419 baudrate - see CONFIG_BAUDRATE
5421 bootdelay - see CONFIG_BOOTDELAY
5423 bootcmd - see CONFIG_BOOTCOMMAND
5425 bootargs - Boot arguments when booting an RTOS image
5427 bootfile - Name of the image to load with TFTP
5429 bootm_low - Memory range available for image processing in the bootm
5430 command can be restricted. This variable is given as
5431 a hexadecimal number and defines lowest address allowed
5432 for use by the bootm command. See also "bootm_size"
5433 environment variable. Address defined by "bootm_low" is
5434 also the base of the initial memory mapping for the Linux
5435 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5438 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5439 This variable is given as a hexadecimal number and it
5440 defines the size of the memory region starting at base
5441 address bootm_low that is accessible by the Linux kernel
5442 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5443 as the default value if it is defined, and bootm_size is
5446 bootm_size - Memory range available for image processing in the bootm
5447 command can be restricted. This variable is given as
5448 a hexadecimal number and defines the size of the region
5449 allowed for use by the bootm command. See also "bootm_low"
5450 environment variable.
5452 updatefile - Location of the software update file on a TFTP server, used
5453 by the automatic software update feature. Please refer to
5454 documentation in doc/README.update for more details.
5456 autoload - if set to "no" (any string beginning with 'n'),
5457 "bootp" will just load perform a lookup of the
5458 configuration from the BOOTP server, but not try to
5459 load any image using TFTP
5461 autostart - if set to "yes", an image loaded using the "bootp",
5462 "rarpboot", "tftpboot" or "diskboot" commands will
5463 be automatically started (by internally calling
5466 If set to "no", a standalone image passed to the
5467 "bootm" command will be copied to the load address
5468 (and eventually uncompressed), but NOT be started.
5469 This can be used to load and uncompress arbitrary
5472 fdt_high - if set this restricts the maximum address that the
5473 flattened device tree will be copied into upon boot.
5474 For example, if you have a system with 1 GB memory
5475 at physical address 0x10000000, while Linux kernel
5476 only recognizes the first 704 MB as low memory, you
5477 may need to set fdt_high as 0x3C000000 to have the
5478 device tree blob be copied to the maximum address
5479 of the 704 MB low memory, so that Linux kernel can
5480 access it during the boot procedure.
5482 If this is set to the special value 0xFFFFFFFF then
5483 the fdt will not be copied at all on boot. For this
5484 to work it must reside in writable memory, have
5485 sufficient padding on the end of it for u-boot to
5486 add the information it needs into it, and the memory
5487 must be accessible by the kernel.
5489 fdtcontroladdr- if set this is the address of the control flattened
5490 device tree used by U-Boot when CONFIG_OF_CONTROL is
5493 i2cfast - (PPC405GP|PPC405EP only)
5494 if set to 'y' configures Linux I2C driver for fast
5495 mode (400kHZ). This environment variable is used in
5496 initialization code. So, for changes to be effective
5497 it must be saved and board must be reset.
5499 initrd_high - restrict positioning of initrd images:
5500 If this variable is not set, initrd images will be
5501 copied to the highest possible address in RAM; this
5502 is usually what you want since it allows for
5503 maximum initrd size. If for some reason you want to
5504 make sure that the initrd image is loaded below the
5505 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5506 variable to a value of "no" or "off" or "0".
5507 Alternatively, you can set it to a maximum upper
5508 address to use (U-Boot will still check that it
5509 does not overwrite the U-Boot stack and data).
5511 For instance, when you have a system with 16 MB
5512 RAM, and want to reserve 4 MB from use by Linux,
5513 you can do this by adding "mem=12M" to the value of
5514 the "bootargs" variable. However, now you must make
5515 sure that the initrd image is placed in the first
5516 12 MB as well - this can be done with
5518 setenv initrd_high 00c00000
5520 If you set initrd_high to 0xFFFFFFFF, this is an
5521 indication to U-Boot that all addresses are legal
5522 for the Linux kernel, including addresses in flash
5523 memory. In this case U-Boot will NOT COPY the
5524 ramdisk at all. This may be useful to reduce the
5525 boot time on your system, but requires that this
5526 feature is supported by your Linux kernel.
5528 ipaddr - IP address; needed for tftpboot command
5530 loadaddr - Default load address for commands like "bootp",
5531 "rarpboot", "tftpboot", "loadb" or "diskboot"
5533 loads_echo - see CONFIG_LOADS_ECHO
5535 serverip - TFTP server IP address; needed for tftpboot command
5537 bootretry - see CONFIG_BOOT_RETRY_TIME
5539 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5541 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5543 ethprime - controls which interface is used first.
5545 ethact - controls which interface is currently active.
5546 For example you can do the following
5548 => setenv ethact FEC
5549 => ping 192.168.0.1 # traffic sent on FEC
5550 => setenv ethact SCC
5551 => ping 10.0.0.1 # traffic sent on SCC
5553 ethrotate - When set to "no" U-Boot does not go through all
5554 available network interfaces.
5555 It just stays at the currently selected interface.
5557 netretry - When set to "no" each network operation will
5558 either succeed or fail without retrying.
5559 When set to "once" the network operation will
5560 fail when all the available network interfaces
5561 are tried once without success.
5562 Useful on scripts which control the retry operation
5565 npe_ucode - set load address for the NPE microcode
5567 silent_linux - If set then Linux will be told to boot silently, by
5568 changing the console to be empty. If "yes" it will be
5569 made silent. If "no" it will not be made silent. If
5570 unset, then it will be made silent if the U-Boot console
5573 tftpsrcport - If this is set, the value is used for TFTP's
5576 tftpdstport - If this is set, the value is used for TFTP's UDP
5577 destination port instead of the Well Know Port 69.
5579 tftpblocksize - Block size to use for TFTP transfers; if not set,
5580 we use the TFTP server's default block size
5582 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5583 seconds, minimum value is 1000 = 1 second). Defines
5584 when a packet is considered to be lost so it has to
5585 be retransmitted. The default is 5000 = 5 seconds.
5586 Lowering this value may make downloads succeed
5587 faster in networks with high packet loss rates or
5588 with unreliable TFTP servers.
5590 vlan - When set to a value < 4095 the traffic over
5591 Ethernet is encapsulated/received over 802.1q
5594 The following image location variables contain the location of images
5595 used in booting. The "Image" column gives the role of the image and is
5596 not an environment variable name. The other columns are environment
5597 variable names. "File Name" gives the name of the file on a TFTP
5598 server, "RAM Address" gives the location in RAM the image will be
5599 loaded to, and "Flash Location" gives the image's address in NOR
5600 flash or offset in NAND flash.
5602 *Note* - these variables don't have to be defined for all boards, some
5603 boards currenlty use other variables for these purposes, and some
5604 boards use these variables for other purposes.
5606 Image File Name RAM Address Flash Location
5607 ----- --------- ----------- --------------
5608 u-boot u-boot u-boot_addr_r u-boot_addr
5609 Linux kernel bootfile kernel_addr_r kernel_addr
5610 device tree blob fdtfile fdt_addr_r fdt_addr
5611 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5613 The following environment variables may be used and automatically
5614 updated by the network boot commands ("bootp" and "rarpboot"),
5615 depending the information provided by your boot server:
5617 bootfile - see above
5618 dnsip - IP address of your Domain Name Server
5619 dnsip2 - IP address of your secondary Domain Name Server
5620 gatewayip - IP address of the Gateway (Router) to use
5621 hostname - Target hostname
5623 netmask - Subnet Mask
5624 rootpath - Pathname of the root filesystem on the NFS server
5625 serverip - see above
5628 There are two special Environment Variables:
5630 serial# - contains hardware identification information such
5631 as type string and/or serial number
5632 ethaddr - Ethernet address
5634 These variables can be set only once (usually during manufacturing of
5635 the board). U-Boot refuses to delete or overwrite these variables
5636 once they have been set once.
5639 Further special Environment Variables:
5641 ver - Contains the U-Boot version string as printed
5642 with the "version" command. This variable is
5643 readonly (see CONFIG_VERSION_VARIABLE).
5646 Please note that changes to some configuration parameters may take
5647 only effect after the next boot (yes, that's just like Windoze :-).
5650 Callback functions for environment variables:
5651 ---------------------------------------------
5653 For some environment variables, the behavior of u-boot needs to change
5654 when their values are changed. This functionality allows functions to
5655 be associated with arbitrary variables. On creation, overwrite, or
5656 deletion, the callback will provide the opportunity for some side
5657 effect to happen or for the change to be rejected.
5659 The callbacks are named and associated with a function using the
5660 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5662 These callbacks are associated with variables in one of two ways. The
5663 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5664 in the board configuration to a string that defines a list of
5665 associations. The list must be in the following format:
5667 entry = variable_name[:callback_name]
5670 If the callback name is not specified, then the callback is deleted.
5671 Spaces are also allowed anywhere in the list.
5673 Callbacks can also be associated by defining the ".callbacks" variable
5674 with the same list format above. Any association in ".callbacks" will
5675 override any association in the static list. You can define
5676 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5677 ".callbacks" environment variable in the default or embedded environment.
5680 Command Line Parsing:
5681 =====================
5683 There are two different command line parsers available with U-Boot:
5684 the old "simple" one, and the much more powerful "hush" shell:
5686 Old, simple command line parser:
5687 --------------------------------
5689 - supports environment variables (through setenv / saveenv commands)
5690 - several commands on one line, separated by ';'
5691 - variable substitution using "... ${name} ..." syntax
5692 - special characters ('$', ';') can be escaped by prefixing with '\',
5694 setenv bootcmd bootm \${address}
5695 - You can also escape text by enclosing in single apostrophes, for example:
5696 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5701 - similar to Bourne shell, with control structures like
5702 if...then...else...fi, for...do...done; while...do...done,
5703 until...do...done, ...
5704 - supports environment ("global") variables (through setenv / saveenv
5705 commands) and local shell variables (through standard shell syntax
5706 "name=value"); only environment variables can be used with "run"
5712 (1) If a command line (or an environment variable executed by a "run"
5713 command) contains several commands separated by semicolon, and
5714 one of these commands fails, then the remaining commands will be
5717 (2) If you execute several variables with one call to run (i. e.
5718 calling run with a list of variables as arguments), any failing
5719 command will cause "run" to terminate, i. e. the remaining
5720 variables are not executed.
5722 Note for Redundant Ethernet Interfaces:
5723 =======================================
5725 Some boards come with redundant Ethernet interfaces; U-Boot supports
5726 such configurations and is capable of automatic selection of a
5727 "working" interface when needed. MAC assignment works as follows:
5729 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5730 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5731 "eth1addr" (=>eth1), "eth2addr", ...
5733 If the network interface stores some valid MAC address (for instance
5734 in SROM), this is used as default address if there is NO correspon-
5735 ding setting in the environment; if the corresponding environment
5736 variable is set, this overrides the settings in the card; that means:
5738 o If the SROM has a valid MAC address, and there is no address in the
5739 environment, the SROM's address is used.
5741 o If there is no valid address in the SROM, and a definition in the
5742 environment exists, then the value from the environment variable is
5745 o If both the SROM and the environment contain a MAC address, and
5746 both addresses are the same, this MAC address is used.
5748 o If both the SROM and the environment contain a MAC address, and the
5749 addresses differ, the value from the environment is used and a
5752 o If neither SROM nor the environment contain a MAC address, an error
5755 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5756 will be programmed into hardware as part of the initialization process. This
5757 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5758 The naming convention is as follows:
5759 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5764 U-Boot is capable of booting (and performing other auxiliary operations on)
5765 images in two formats:
5767 New uImage format (FIT)
5768 -----------------------
5770 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5771 to Flattened Device Tree). It allows the use of images with multiple
5772 components (several kernels, ramdisks, etc.), with contents protected by
5773 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5779 Old image format is based on binary files which can be basically anything,
5780 preceded by a special header; see the definitions in include/image.h for
5781 details; basically, the header defines the following image properties:
5783 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5784 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5785 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5786 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5788 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5789 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5790 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5791 * Compression Type (uncompressed, gzip, bzip2)
5797 The header is marked by a special Magic Number, and both the header
5798 and the data portions of the image are secured against corruption by
5805 Although U-Boot should support any OS or standalone application
5806 easily, the main focus has always been on Linux during the design of
5809 U-Boot includes many features that so far have been part of some
5810 special "boot loader" code within the Linux kernel. Also, any
5811 "initrd" images to be used are no longer part of one big Linux image;
5812 instead, kernel and "initrd" are separate images. This implementation
5813 serves several purposes:
5815 - the same features can be used for other OS or standalone
5816 applications (for instance: using compressed images to reduce the
5817 Flash memory footprint)
5819 - it becomes much easier to port new Linux kernel versions because
5820 lots of low-level, hardware dependent stuff are done by U-Boot
5822 - the same Linux kernel image can now be used with different "initrd"
5823 images; of course this also means that different kernel images can
5824 be run with the same "initrd". This makes testing easier (you don't
5825 have to build a new "zImage.initrd" Linux image when you just
5826 change a file in your "initrd"). Also, a field-upgrade of the
5827 software is easier now.
5833 Porting Linux to U-Boot based systems:
5834 ---------------------------------------
5836 U-Boot cannot save you from doing all the necessary modifications to
5837 configure the Linux device drivers for use with your target hardware
5838 (no, we don't intend to provide a full virtual machine interface to
5841 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5843 Just make sure your machine specific header file (for instance
5844 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5845 Information structure as we define in include/asm-<arch>/u-boot.h,
5846 and make sure that your definition of IMAP_ADDR uses the same value
5847 as your U-Boot configuration in CONFIG_SYS_IMMR.
5849 Note that U-Boot now has a driver model, a unified model for drivers.
5850 If you are adding a new driver, plumb it into driver model. If there
5851 is no uclass available, you are encouraged to create one. See
5855 Configuring the Linux kernel:
5856 -----------------------------
5858 No specific requirements for U-Boot. Make sure you have some root
5859 device (initial ramdisk, NFS) for your target system.
5862 Building a Linux Image:
5863 -----------------------
5865 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5866 not used. If you use recent kernel source, a new build target
5867 "uImage" will exist which automatically builds an image usable by
5868 U-Boot. Most older kernels also have support for a "pImage" target,
5869 which was introduced for our predecessor project PPCBoot and uses a
5870 100% compatible format.
5874 make TQM850L_defconfig
5879 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5880 encapsulate a compressed Linux kernel image with header information,
5881 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5883 * build a standard "vmlinux" kernel image (in ELF binary format):
5885 * convert the kernel into a raw binary image:
5887 ${CROSS_COMPILE}-objcopy -O binary \
5888 -R .note -R .comment \
5889 -S vmlinux linux.bin
5891 * compress the binary image:
5895 * package compressed binary image for U-Boot:
5897 mkimage -A ppc -O linux -T kernel -C gzip \
5898 -a 0 -e 0 -n "Linux Kernel Image" \
5899 -d linux.bin.gz uImage
5902 The "mkimage" tool can also be used to create ramdisk images for use
5903 with U-Boot, either separated from the Linux kernel image, or
5904 combined into one file. "mkimage" encapsulates the images with a 64
5905 byte header containing information about target architecture,
5906 operating system, image type, compression method, entry points, time
5907 stamp, CRC32 checksums, etc.
5909 "mkimage" can be called in two ways: to verify existing images and
5910 print the header information, or to build new images.
5912 In the first form (with "-l" option) mkimage lists the information
5913 contained in the header of an existing U-Boot image; this includes
5914 checksum verification:
5916 tools/mkimage -l image
5917 -l ==> list image header information
5919 The second form (with "-d" option) is used to build a U-Boot image
5920 from a "data file" which is used as image payload:
5922 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5923 -n name -d data_file image
5924 -A ==> set architecture to 'arch'
5925 -O ==> set operating system to 'os'
5926 -T ==> set image type to 'type'
5927 -C ==> set compression type 'comp'
5928 -a ==> set load address to 'addr' (hex)
5929 -e ==> set entry point to 'ep' (hex)
5930 -n ==> set image name to 'name'
5931 -d ==> use image data from 'datafile'
5933 Right now, all Linux kernels for PowerPC systems use the same load
5934 address (0x00000000), but the entry point address depends on the
5937 - 2.2.x kernels have the entry point at 0x0000000C,
5938 - 2.3.x and later kernels have the entry point at 0x00000000.
5940 So a typical call to build a U-Boot image would read:
5942 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5943 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5944 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5945 > examples/uImage.TQM850L
5946 Image Name: 2.4.4 kernel for TQM850L
5947 Created: Wed Jul 19 02:34:59 2000
5948 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5949 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5950 Load Address: 0x00000000
5951 Entry Point: 0x00000000
5953 To verify the contents of the image (or check for corruption):
5955 -> tools/mkimage -l examples/uImage.TQM850L
5956 Image Name: 2.4.4 kernel for TQM850L
5957 Created: Wed Jul 19 02:34:59 2000
5958 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5959 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5960 Load Address: 0x00000000
5961 Entry Point: 0x00000000
5963 NOTE: for embedded systems where boot time is critical you can trade
5964 speed for memory and install an UNCOMPRESSED image instead: this
5965 needs more space in Flash, but boots much faster since it does not
5966 need to be uncompressed:
5968 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5969 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5970 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5971 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5972 > examples/uImage.TQM850L-uncompressed
5973 Image Name: 2.4.4 kernel for TQM850L
5974 Created: Wed Jul 19 02:34:59 2000
5975 Image Type: PowerPC Linux Kernel Image (uncompressed)
5976 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5977 Load Address: 0x00000000
5978 Entry Point: 0x00000000
5981 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5982 when your kernel is intended to use an initial ramdisk:
5984 -> tools/mkimage -n 'Simple Ramdisk Image' \
5985 > -A ppc -O linux -T ramdisk -C gzip \
5986 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5987 Image Name: Simple Ramdisk Image
5988 Created: Wed Jan 12 14:01:50 2000
5989 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5990 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5991 Load Address: 0x00000000
5992 Entry Point: 0x00000000
5994 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5995 option performs the converse operation of the mkimage's second form (the "-d"
5996 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5999 tools/dumpimage -i image -T type -p position data_file
6000 -i ==> extract from the 'image' a specific 'data_file'
6001 -T ==> set image type to 'type'
6002 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6005 Installing a Linux Image:
6006 -------------------------
6008 To downloading a U-Boot image over the serial (console) interface,
6009 you must convert the image to S-Record format:
6011 objcopy -I binary -O srec examples/image examples/image.srec
6013 The 'objcopy' does not understand the information in the U-Boot
6014 image header, so the resulting S-Record file will be relative to
6015 address 0x00000000. To load it to a given address, you need to
6016 specify the target address as 'offset' parameter with the 'loads'
6019 Example: install the image to address 0x40100000 (which on the
6020 TQM8xxL is in the first Flash bank):
6022 => erase 40100000 401FFFFF
6028 ## Ready for S-Record download ...
6029 ~>examples/image.srec
6030 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6032 15989 15990 15991 15992
6033 [file transfer complete]
6035 ## Start Addr = 0x00000000
6038 You can check the success of the download using the 'iminfo' command;
6039 this includes a checksum verification so you can be sure no data
6040 corruption happened:
6044 ## Checking Image at 40100000 ...
6045 Image Name: 2.2.13 for initrd on TQM850L
6046 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6047 Data Size: 335725 Bytes = 327 kB = 0 MB
6048 Load Address: 00000000
6049 Entry Point: 0000000c
6050 Verifying Checksum ... OK
6056 The "bootm" command is used to boot an application that is stored in
6057 memory (RAM or Flash). In case of a Linux kernel image, the contents
6058 of the "bootargs" environment variable is passed to the kernel as
6059 parameters. You can check and modify this variable using the
6060 "printenv" and "setenv" commands:
6063 => printenv bootargs
6064 bootargs=root=/dev/ram
6066 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6068 => printenv bootargs
6069 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6072 ## Booting Linux kernel at 40020000 ...
6073 Image Name: 2.2.13 for NFS on TQM850L
6074 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6075 Data Size: 381681 Bytes = 372 kB = 0 MB
6076 Load Address: 00000000
6077 Entry Point: 0000000c
6078 Verifying Checksum ... OK
6079 Uncompressing Kernel Image ... OK
6080 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
6081 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6082 time_init: decrementer frequency = 187500000/60
6083 Calibrating delay loop... 49.77 BogoMIPS
6084 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6087 If you want to boot a Linux kernel with initial RAM disk, you pass
6088 the memory addresses of both the kernel and the initrd image (PPBCOOT
6089 format!) to the "bootm" command:
6091 => imi 40100000 40200000
6093 ## Checking Image at 40100000 ...
6094 Image Name: 2.2.13 for initrd on TQM850L
6095 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6096 Data Size: 335725 Bytes = 327 kB = 0 MB
6097 Load Address: 00000000
6098 Entry Point: 0000000c
6099 Verifying Checksum ... OK
6101 ## Checking Image at 40200000 ...
6102 Image Name: Simple Ramdisk Image
6103 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6104 Data Size: 566530 Bytes = 553 kB = 0 MB
6105 Load Address: 00000000
6106 Entry Point: 00000000
6107 Verifying Checksum ... OK
6109 => bootm 40100000 40200000
6110 ## Booting Linux kernel at 40100000 ...
6111 Image Name: 2.2.13 for initrd on TQM850L
6112 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6113 Data Size: 335725 Bytes = 327 kB = 0 MB
6114 Load Address: 00000000
6115 Entry Point: 0000000c
6116 Verifying Checksum ... OK
6117 Uncompressing Kernel Image ... OK
6118 ## Loading RAMDisk Image at 40200000 ...
6119 Image Name: Simple Ramdisk Image
6120 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6121 Data Size: 566530 Bytes = 553 kB = 0 MB
6122 Load Address: 00000000
6123 Entry Point: 00000000
6124 Verifying Checksum ... OK
6125 Loading Ramdisk ... OK
6126 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
6127 Boot arguments: root=/dev/ram
6128 time_init: decrementer frequency = 187500000/60
6129 Calibrating delay loop... 49.77 BogoMIPS
6131 RAMDISK: Compressed image found at block 0
6132 VFS: Mounted root (ext2 filesystem).
6136 Boot Linux and pass a flat device tree:
6139 First, U-Boot must be compiled with the appropriate defines. See the section
6140 titled "Linux Kernel Interface" above for a more in depth explanation. The
6141 following is an example of how to start a kernel and pass an updated
6147 oft=oftrees/mpc8540ads.dtb
6148 => tftp $oftaddr $oft
6149 Speed: 1000, full duplex
6151 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6152 Filename 'oftrees/mpc8540ads.dtb'.
6153 Load address: 0x300000
6156 Bytes transferred = 4106 (100a hex)
6157 => tftp $loadaddr $bootfile
6158 Speed: 1000, full duplex
6160 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6162 Load address: 0x200000
6163 Loading:############
6165 Bytes transferred = 1029407 (fb51f hex)
6170 => bootm $loadaddr - $oftaddr
6171 ## Booting image at 00200000 ...
6172 Image Name: Linux-2.6.17-dirty
6173 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6174 Data Size: 1029343 Bytes = 1005.2 kB
6175 Load Address: 00000000
6176 Entry Point: 00000000
6177 Verifying Checksum ... OK
6178 Uncompressing Kernel Image ... OK
6179 Booting using flat device tree at 0x300000
6180 Using MPC85xx ADS machine description
6181 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6185 More About U-Boot Image Types:
6186 ------------------------------
6188 U-Boot supports the following image types:
6190 "Standalone Programs" are directly runnable in the environment
6191 provided by U-Boot; it is expected that (if they behave
6192 well) you can continue to work in U-Boot after return from
6193 the Standalone Program.
6194 "OS Kernel Images" are usually images of some Embedded OS which
6195 will take over control completely. Usually these programs
6196 will install their own set of exception handlers, device
6197 drivers, set up the MMU, etc. - this means, that you cannot
6198 expect to re-enter U-Boot except by resetting the CPU.
6199 "RAMDisk Images" are more or less just data blocks, and their
6200 parameters (address, size) are passed to an OS kernel that is
6202 "Multi-File Images" contain several images, typically an OS
6203 (Linux) kernel image and one or more data images like
6204 RAMDisks. This construct is useful for instance when you want
6205 to boot over the network using BOOTP etc., where the boot
6206 server provides just a single image file, but you want to get
6207 for instance an OS kernel and a RAMDisk image.
6209 "Multi-File Images" start with a list of image sizes, each
6210 image size (in bytes) specified by an "uint32_t" in network
6211 byte order. This list is terminated by an "(uint32_t)0".
6212 Immediately after the terminating 0 follow the images, one by
6213 one, all aligned on "uint32_t" boundaries (size rounded up to
6214 a multiple of 4 bytes).
6216 "Firmware Images" are binary images containing firmware (like
6217 U-Boot or FPGA images) which usually will be programmed to
6220 "Script files" are command sequences that will be executed by
6221 U-Boot's command interpreter; this feature is especially
6222 useful when you configure U-Boot to use a real shell (hush)
6223 as command interpreter.
6225 Booting the Linux zImage:
6226 -------------------------
6228 On some platforms, it's possible to boot Linux zImage. This is done
6229 using the "bootz" command. The syntax of "bootz" command is the same
6230 as the syntax of "bootm" command.
6232 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6233 kernel with raw initrd images. The syntax is slightly different, the
6234 address of the initrd must be augmented by it's size, in the following
6235 format: "<initrd addres>:<initrd size>".
6241 One of the features of U-Boot is that you can dynamically load and
6242 run "standalone" applications, which can use some resources of
6243 U-Boot like console I/O functions or interrupt services.
6245 Two simple examples are included with the sources:
6250 'examples/hello_world.c' contains a small "Hello World" Demo
6251 application; it is automatically compiled when you build U-Boot.
6252 It's configured to run at address 0x00040004, so you can play with it
6256 ## Ready for S-Record download ...
6257 ~>examples/hello_world.srec
6258 1 2 3 4 5 6 7 8 9 10 11 ...
6259 [file transfer complete]
6261 ## Start Addr = 0x00040004
6263 => go 40004 Hello World! This is a test.
6264 ## Starting application at 0x00040004 ...
6275 Hit any key to exit ...
6277 ## Application terminated, rc = 0x0
6279 Another example, which demonstrates how to register a CPM interrupt
6280 handler with the U-Boot code, can be found in 'examples/timer.c'.
6281 Here, a CPM timer is set up to generate an interrupt every second.
6282 The interrupt service routine is trivial, just printing a '.'
6283 character, but this is just a demo program. The application can be
6284 controlled by the following keys:
6286 ? - print current values og the CPM Timer registers
6287 b - enable interrupts and start timer
6288 e - stop timer and disable interrupts
6289 q - quit application
6292 ## Ready for S-Record download ...
6293 ~>examples/timer.srec
6294 1 2 3 4 5 6 7 8 9 10 11 ...
6295 [file transfer complete]
6297 ## Start Addr = 0x00040004
6300 ## Starting application at 0x00040004 ...
6303 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6306 [q, b, e, ?] Set interval 1000000 us
6309 [q, b, e, ?] ........
6310 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6313 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6316 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6319 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6321 [q, b, e, ?] ...Stopping timer
6323 [q, b, e, ?] ## Application terminated, rc = 0x0
6329 Over time, many people have reported problems when trying to use the
6330 "minicom" terminal emulation program for serial download. I (wd)
6331 consider minicom to be broken, and recommend not to use it. Under
6332 Unix, I recommend to use C-Kermit for general purpose use (and
6333 especially for kermit binary protocol download ("loadb" command), and
6334 use "cu" for S-Record download ("loads" command). See
6335 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6336 for help with kermit.
6339 Nevertheless, if you absolutely want to use it try adding this
6340 configuration to your "File transfer protocols" section:
6342 Name Program Name U/D FullScr IO-Red. Multi
6343 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6344 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6350 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6351 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6353 Building requires a cross environment; it is known to work on
6354 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6355 need gmake since the Makefiles are not compatible with BSD make).
6356 Note that the cross-powerpc package does not install include files;
6357 attempting to build U-Boot will fail because <machine/ansi.h> is
6358 missing. This file has to be installed and patched manually:
6360 # cd /usr/pkg/cross/powerpc-netbsd/include
6362 # ln -s powerpc machine
6363 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6364 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6366 Native builds *don't* work due to incompatibilities between native
6367 and U-Boot include files.
6369 Booting assumes that (the first part of) the image booted is a
6370 stage-2 loader which in turn loads and then invokes the kernel
6371 proper. Loader sources will eventually appear in the NetBSD source
6372 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6373 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6376 Implementation Internals:
6377 =========================
6379 The following is not intended to be a complete description of every
6380 implementation detail. However, it should help to understand the
6381 inner workings of U-Boot and make it easier to port it to custom
6385 Initial Stack, Global Data:
6386 ---------------------------
6388 The implementation of U-Boot is complicated by the fact that U-Boot
6389 starts running out of ROM (flash memory), usually without access to
6390 system RAM (because the memory controller is not initialized yet).
6391 This means that we don't have writable Data or BSS segments, and BSS
6392 is not initialized as zero. To be able to get a C environment working
6393 at all, we have to allocate at least a minimal stack. Implementation
6394 options for this are defined and restricted by the CPU used: Some CPU
6395 models provide on-chip memory (like the IMMR area on MPC8xx and
6396 MPC826x processors), on others (parts of) the data cache can be
6397 locked as (mis-) used as memory, etc.
6399 Chris Hallinan posted a good summary of these issues to the
6400 U-Boot mailing list:
6402 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6403 From: "Chris Hallinan" <clh@net1plus.com>
6404 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6407 Correct me if I'm wrong, folks, but the way I understand it
6408 is this: Using DCACHE as initial RAM for Stack, etc, does not
6409 require any physical RAM backing up the cache. The cleverness
6410 is that the cache is being used as a temporary supply of
6411 necessary storage before the SDRAM controller is setup. It's
6412 beyond the scope of this list to explain the details, but you
6413 can see how this works by studying the cache architecture and
6414 operation in the architecture and processor-specific manuals.
6416 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6417 is another option for the system designer to use as an
6418 initial stack/RAM area prior to SDRAM being available. Either
6419 option should work for you. Using CS 4 should be fine if your
6420 board designers haven't used it for something that would
6421 cause you grief during the initial boot! It is frequently not
6424 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6425 with your processor/board/system design. The default value
6426 you will find in any recent u-boot distribution in
6427 walnut.h should work for you. I'd set it to a value larger
6428 than your SDRAM module. If you have a 64MB SDRAM module, set
6429 it above 400_0000. Just make sure your board has no resources
6430 that are supposed to respond to that address! That code in
6431 start.S has been around a while and should work as is when
6432 you get the config right.
6437 It is essential to remember this, since it has some impact on the C
6438 code for the initialization procedures:
6440 * Initialized global data (data segment) is read-only. Do not attempt
6443 * Do not use any uninitialized global data (or implicitly initialized
6444 as zero data - BSS segment) at all - this is undefined, initiali-
6445 zation is performed later (when relocating to RAM).
6447 * Stack space is very limited. Avoid big data buffers or things like
6450 Having only the stack as writable memory limits means we cannot use
6451 normal global data to share information between the code. But it
6452 turned out that the implementation of U-Boot can be greatly
6453 simplified by making a global data structure (gd_t) available to all
6454 functions. We could pass a pointer to this data as argument to _all_
6455 functions, but this would bloat the code. Instead we use a feature of
6456 the GCC compiler (Global Register Variables) to share the data: we
6457 place a pointer (gd) to the global data into a register which we
6458 reserve for this purpose.
6460 When choosing a register for such a purpose we are restricted by the
6461 relevant (E)ABI specifications for the current architecture, and by
6462 GCC's implementation.
6464 For PowerPC, the following registers have specific use:
6466 R2: reserved for system use
6467 R3-R4: parameter passing and return values
6468 R5-R10: parameter passing
6469 R13: small data area pointer
6473 (U-Boot also uses R12 as internal GOT pointer. r12
6474 is a volatile register so r12 needs to be reset when
6475 going back and forth between asm and C)
6477 ==> U-Boot will use R2 to hold a pointer to the global data
6479 Note: on PPC, we could use a static initializer (since the
6480 address of the global data structure is known at compile time),
6481 but it turned out that reserving a register results in somewhat
6482 smaller code - although the code savings are not that big (on
6483 average for all boards 752 bytes for the whole U-Boot image,
6484 624 text + 127 data).
6486 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6487 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6489 ==> U-Boot will use P3 to hold a pointer to the global data
6491 On ARM, the following registers are used:
6493 R0: function argument word/integer result
6494 R1-R3: function argument word
6495 R9: platform specific
6496 R10: stack limit (used only if stack checking is enabled)
6497 R11: argument (frame) pointer
6498 R12: temporary workspace
6501 R15: program counter
6503 ==> U-Boot will use R9 to hold a pointer to the global data
6505 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6507 On Nios II, the ABI is documented here:
6508 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6510 ==> U-Boot will use gp to hold a pointer to the global data
6512 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6513 to access small data sections, so gp is free.
6515 On NDS32, the following registers are used:
6517 R0-R1: argument/return
6519 R15: temporary register for assembler
6520 R16: trampoline register
6521 R28: frame pointer (FP)
6522 R29: global pointer (GP)
6523 R30: link register (LP)
6524 R31: stack pointer (SP)
6525 PC: program counter (PC)
6527 ==> U-Boot will use R10 to hold a pointer to the global data
6529 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6530 or current versions of GCC may "optimize" the code too much.
6535 U-Boot runs in system state and uses physical addresses, i.e. the
6536 MMU is not used either for address mapping nor for memory protection.
6538 The available memory is mapped to fixed addresses using the memory
6539 controller. In this process, a contiguous block is formed for each
6540 memory type (Flash, SDRAM, SRAM), even when it consists of several
6541 physical memory banks.
6543 U-Boot is installed in the first 128 kB of the first Flash bank (on
6544 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6545 booting and sizing and initializing DRAM, the code relocates itself
6546 to the upper end of DRAM. Immediately below the U-Boot code some
6547 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6548 configuration setting]. Below that, a structure with global Board
6549 Info data is placed, followed by the stack (growing downward).
6551 Additionally, some exception handler code is copied to the low 8 kB
6552 of DRAM (0x00000000 ... 0x00001FFF).
6554 So a typical memory configuration with 16 MB of DRAM could look like
6557 0x0000 0000 Exception Vector code
6560 0x0000 2000 Free for Application Use
6566 0x00FB FF20 Monitor Stack (Growing downward)
6567 0x00FB FFAC Board Info Data and permanent copy of global data
6568 0x00FC 0000 Malloc Arena
6571 0x00FE 0000 RAM Copy of Monitor Code
6572 ... eventually: LCD or video framebuffer
6573 ... eventually: pRAM (Protected RAM - unchanged by reset)
6574 0x00FF FFFF [End of RAM]
6577 System Initialization:
6578 ----------------------
6580 In the reset configuration, U-Boot starts at the reset entry point
6581 (on most PowerPC systems at address 0x00000100). Because of the reset
6582 configuration for CS0# this is a mirror of the on board Flash memory.
6583 To be able to re-map memory U-Boot then jumps to its link address.
6584 To be able to implement the initialization code in C, a (small!)
6585 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6586 which provide such a feature like MPC8xx or MPC8260), or in a locked
6587 part of the data cache. After that, U-Boot initializes the CPU core,
6588 the caches and the SIU.
6590 Next, all (potentially) available memory banks are mapped using a
6591 preliminary mapping. For example, we put them on 512 MB boundaries
6592 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6593 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6594 programmed for SDRAM access. Using the temporary configuration, a
6595 simple memory test is run that determines the size of the SDRAM
6598 When there is more than one SDRAM bank, and the banks are of
6599 different size, the largest is mapped first. For equal size, the first
6600 bank (CS2#) is mapped first. The first mapping is always for address
6601 0x00000000, with any additional banks following immediately to create
6602 contiguous memory starting from 0.
6604 Then, the monitor installs itself at the upper end of the SDRAM area
6605 and allocates memory for use by malloc() and for the global Board
6606 Info data; also, the exception vector code is copied to the low RAM
6607 pages, and the final stack is set up.
6609 Only after this relocation will you have a "normal" C environment;
6610 until that you are restricted in several ways, mostly because you are
6611 running from ROM, and because the code will have to be relocated to a
6615 U-Boot Porting Guide:
6616 ----------------------
6618 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6622 int main(int argc, char *argv[])
6624 sighandler_t no_more_time;
6626 signal(SIGALRM, no_more_time);
6627 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6629 if (available_money > available_manpower) {
6630 Pay consultant to port U-Boot;
6634 Download latest U-Boot source;
6636 Subscribe to u-boot mailing list;
6639 email("Hi, I am new to U-Boot, how do I get started?");
6642 Read the README file in the top level directory;
6643 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6644 Read applicable doc/*.README;
6645 Read the source, Luke;
6646 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6649 if (available_money > toLocalCurrency ($2500))
6652 Add a lot of aggravation and time;
6654 if (a similar board exists) { /* hopefully... */
6655 cp -a board/<similar> board/<myboard>
6656 cp include/configs/<similar>.h include/configs/<myboard>.h
6658 Create your own board support subdirectory;
6659 Create your own board include/configs/<myboard>.h file;
6661 Edit new board/<myboard> files
6662 Edit new include/configs/<myboard>.h
6667 Add / modify source code;
6671 email("Hi, I am having problems...");
6673 Send patch file to the U-Boot email list;
6674 if (reasonable critiques)
6675 Incorporate improvements from email list code review;
6677 Defend code as written;
6683 void no_more_time (int sig)
6692 All contributions to U-Boot should conform to the Linux kernel
6693 coding style; see the file "Documentation/CodingStyle" and the script
6694 "scripts/Lindent" in your Linux kernel source directory.
6696 Source files originating from a different project (for example the
6697 MTD subsystem) are generally exempt from these guidelines and are not
6698 reformatted to ease subsequent migration to newer versions of those
6701 Please note that U-Boot is implemented in C (and to some small parts in
6702 Assembler); no C++ is used, so please do not use C++ style comments (//)
6705 Please also stick to the following formatting rules:
6706 - remove any trailing white space
6707 - use TAB characters for indentation and vertical alignment, not spaces
6708 - make sure NOT to use DOS '\r\n' line feeds
6709 - do not add more than 2 consecutive empty lines to source files
6710 - do not add trailing empty lines to source files
6712 Submissions which do not conform to the standards may be returned
6713 with a request to reformat the changes.
6719 Since the number of patches for U-Boot is growing, we need to
6720 establish some rules. Submissions which do not conform to these rules
6721 may be rejected, even when they contain important and valuable stuff.
6723 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6725 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6726 see http://lists.denx.de/mailman/listinfo/u-boot
6728 When you send a patch, please include the following information with
6731 * For bug fixes: a description of the bug and how your patch fixes
6732 this bug. Please try to include a way of demonstrating that the
6733 patch actually fixes something.
6735 * For new features: a description of the feature and your
6738 * A CHANGELOG entry as plaintext (separate from the patch)
6740 * For major contributions, your entry to the CREDITS file
6742 * When you add support for a new board, don't forget to add a
6743 maintainer e-mail address to the boards.cfg file, too.
6745 * If your patch adds new configuration options, don't forget to
6746 document these in the README file.
6748 * The patch itself. If you are using git (which is *strongly*
6749 recommended) you can easily generate the patch using the
6750 "git format-patch". If you then use "git send-email" to send it to
6751 the U-Boot mailing list, you will avoid most of the common problems
6752 with some other mail clients.
6754 If you cannot use git, use "diff -purN OLD NEW". If your version of
6755 diff does not support these options, then get the latest version of
6758 The current directory when running this command shall be the parent
6759 directory of the U-Boot source tree (i. e. please make sure that
6760 your patch includes sufficient directory information for the
6763 We prefer patches as plain text. MIME attachments are discouraged,
6764 and compressed attachments must not be used.
6766 * If one logical set of modifications affects or creates several
6767 files, all these changes shall be submitted in a SINGLE patch file.
6769 * Changesets that contain different, unrelated modifications shall be
6770 submitted as SEPARATE patches, one patch per changeset.
6775 * Before sending the patch, run the MAKEALL script on your patched
6776 source tree and make sure that no errors or warnings are reported
6777 for any of the boards.
6779 * Keep your modifications to the necessary minimum: A patch
6780 containing several unrelated changes or arbitrary reformats will be
6781 returned with a request to re-formatting / split it.
6783 * If you modify existing code, make sure that your new code does not
6784 add to the memory footprint of the code ;-) Small is beautiful!
6785 When adding new features, these should compile conditionally only
6786 (using #ifdef), and the resulting code with the new feature
6787 disabled must not need more memory than the old code without your
6790 * Remember that there is a size limit of 100 kB per message on the
6791 u-boot mailing list. Bigger patches will be moderated. If they are
6792 reasonable and not too big, they will be acknowledged. But patches
6793 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob