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 Note that when printing the buffer a copy is made on the
1062 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
1064 'Sane' compilers will generate smaller code if
1065 CONFIG_PRE_CON_BUF_SZ is a power of 2
1067 - Safe printf() functions
1068 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1069 the printf() functions. These are defined in
1070 include/vsprintf.h and include snprintf(), vsnprintf() and
1071 so on. Code size increase is approximately 300-500 bytes.
1072 If this option is not given then these functions will
1073 silently discard their buffer size argument - this means
1074 you are not getting any overflow checking in this case.
1076 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1077 Delay before automatically booting the default image;
1078 set to -1 to disable autoboot.
1079 set to -2 to autoboot with no delay and not check for abort
1080 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1082 See doc/README.autoboot for these options that
1083 work with CONFIG_BOOTDELAY. None are required.
1084 CONFIG_BOOT_RETRY_TIME
1085 CONFIG_BOOT_RETRY_MIN
1086 CONFIG_AUTOBOOT_KEYED
1087 CONFIG_AUTOBOOT_PROMPT
1088 CONFIG_AUTOBOOT_DELAY_STR
1089 CONFIG_AUTOBOOT_STOP_STR
1090 CONFIG_ZERO_BOOTDELAY_CHECK
1091 CONFIG_RESET_TO_RETRY
1095 Only needed when CONFIG_BOOTDELAY is enabled;
1096 define a command string that is automatically executed
1097 when no character is read on the console interface
1098 within "Boot Delay" after reset.
1101 This can be used to pass arguments to the bootm
1102 command. The value of CONFIG_BOOTARGS goes into the
1103 environment value "bootargs".
1105 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1106 The value of these goes into the environment as
1107 "ramboot" and "nfsboot" respectively, and can be used
1108 as a convenience, when switching between booting from
1112 CONFIG_BOOTCOUNT_LIMIT
1113 Implements a mechanism for detecting a repeating reboot
1115 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1117 CONFIG_BOOTCOUNT_ENV
1118 If no softreset save registers are found on the hardware
1119 "bootcount" is stored in the environment. To prevent a
1120 saveenv on all reboots, the environment variable
1121 "upgrade_available" is used. If "upgrade_available" is
1122 0, "bootcount" is always 0, if "upgrade_available" is
1123 1 "bootcount" is incremented in the environment.
1124 So the Userspace Applikation must set the "upgrade_available"
1125 and "bootcount" variable to 0, if a boot was successfully.
1127 - Pre-Boot Commands:
1130 When this option is #defined, the existence of the
1131 environment variable "preboot" will be checked
1132 immediately before starting the CONFIG_BOOTDELAY
1133 countdown and/or running the auto-boot command resp.
1134 entering interactive mode.
1136 This feature is especially useful when "preboot" is
1137 automatically generated or modified. For an example
1138 see the LWMON board specific code: here "preboot" is
1139 modified when the user holds down a certain
1140 combination of keys on the (special) keyboard when
1143 - Serial Download Echo Mode:
1145 If defined to 1, all characters received during a
1146 serial download (using the "loads" command) are
1147 echoed back. This might be needed by some terminal
1148 emulations (like "cu"), but may as well just take
1149 time on others. This setting #define's the initial
1150 value of the "loads_echo" environment variable.
1152 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1153 CONFIG_KGDB_BAUDRATE
1154 Select one of the baudrates listed in
1155 CONFIG_SYS_BAUDRATE_TABLE, see below.
1157 - Monitor Functions:
1158 Monitor commands can be included or excluded
1159 from the build by using the #include files
1160 <config_cmd_all.h> and #undef'ing unwanted
1161 commands, or adding #define's for wanted commands.
1163 The default command configuration includes all commands
1164 except those marked below with a "*".
1166 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1167 CONFIG_CMD_ASKENV * ask for env variable
1168 CONFIG_CMD_BDI bdinfo
1169 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1170 CONFIG_CMD_BMP * BMP support
1171 CONFIG_CMD_BSP * Board specific commands
1172 CONFIG_CMD_BOOTD bootd
1173 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1174 CONFIG_CMD_CACHE * icache, dcache
1175 CONFIG_CMD_CLK * clock command support
1176 CONFIG_CMD_CONSOLE coninfo
1177 CONFIG_CMD_CRC32 * crc32
1178 CONFIG_CMD_DATE * support for RTC, date/time...
1179 CONFIG_CMD_DHCP * DHCP support
1180 CONFIG_CMD_DIAG * Diagnostics
1181 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1182 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1183 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1184 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1185 CONFIG_CMD_DTT * Digital Therm and Thermostat
1186 CONFIG_CMD_ECHO echo arguments
1187 CONFIG_CMD_EDITENV edit env variable
1188 CONFIG_CMD_EEPROM * EEPROM read/write support
1189 CONFIG_CMD_ELF * bootelf, bootvx
1190 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1191 CONFIG_CMD_ENV_FLAGS * display details about env flags
1192 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1193 CONFIG_CMD_EXPORTENV * export the environment
1194 CONFIG_CMD_EXT2 * ext2 command support
1195 CONFIG_CMD_EXT4 * ext4 command support
1196 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1197 that work for multiple fs types
1198 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1199 CONFIG_CMD_SAVEENV saveenv
1200 CONFIG_CMD_FDC * Floppy Disk Support
1201 CONFIG_CMD_FAT * FAT command support
1202 CONFIG_CMD_FLASH flinfo, erase, protect
1203 CONFIG_CMD_FPGA FPGA device initialization support
1204 CONFIG_CMD_FUSE * Device fuse support
1205 CONFIG_CMD_GETTIME * Get time since boot
1206 CONFIG_CMD_GO * the 'go' command (exec code)
1207 CONFIG_CMD_GREPENV * search environment
1208 CONFIG_CMD_HASH * calculate hash / digest
1209 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1210 CONFIG_CMD_I2C * I2C serial bus support
1211 CONFIG_CMD_IDE * IDE harddisk support
1212 CONFIG_CMD_IMI iminfo
1213 CONFIG_CMD_IMLS List all images found in NOR flash
1214 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1215 CONFIG_CMD_IMMAP * IMMR dump support
1216 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1217 CONFIG_CMD_IMPORTENV * import an environment
1218 CONFIG_CMD_INI * import data from an ini file into the env
1219 CONFIG_CMD_IRQ * irqinfo
1220 CONFIG_CMD_ITEST Integer/string test of 2 values
1221 CONFIG_CMD_JFFS2 * JFFS2 Support
1222 CONFIG_CMD_KGDB * kgdb
1223 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1224 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1226 CONFIG_CMD_LOADB loadb
1227 CONFIG_CMD_LOADS loads
1228 CONFIG_CMD_MD5SUM * print md5 message digest
1229 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1230 CONFIG_CMD_MEMINFO * Display detailed memory information
1231 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1233 CONFIG_CMD_MEMTEST * mtest
1234 CONFIG_CMD_MISC Misc functions like sleep etc
1235 CONFIG_CMD_MMC * MMC memory mapped support
1236 CONFIG_CMD_MII * MII utility commands
1237 CONFIG_CMD_MTDPARTS * MTD partition support
1238 CONFIG_CMD_NAND * NAND support
1239 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1240 CONFIG_CMD_NFS NFS support
1241 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1242 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1243 CONFIG_CMD_PCI * pciinfo
1244 CONFIG_CMD_PCMCIA * PCMCIA support
1245 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1247 CONFIG_CMD_PORTIO * Port I/O
1248 CONFIG_CMD_READ * Read raw data from partition
1249 CONFIG_CMD_REGINFO * Register dump
1250 CONFIG_CMD_RUN run command in env variable
1251 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1252 CONFIG_CMD_SAVES * save S record dump
1253 CONFIG_CMD_SCSI * SCSI Support
1254 CONFIG_CMD_SDRAM * print SDRAM configuration information
1255 (requires CONFIG_CMD_I2C)
1256 CONFIG_CMD_SETGETDCR Support for DCR Register access
1258 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1259 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1260 (requires CONFIG_CMD_MEMORY)
1261 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1262 CONFIG_CMD_SOURCE "source" command Support
1263 CONFIG_CMD_SPI * SPI serial bus support
1264 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1265 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1266 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1267 CONFIG_CMD_TIMER * access to the system tick timer
1268 CONFIG_CMD_USB * USB support
1269 CONFIG_CMD_CDP * Cisco Discover Protocol support
1270 CONFIG_CMD_MFSL * Microblaze FSL support
1271 CONFIG_CMD_XIMG Load part of Multi Image
1272 CONFIG_CMD_UUID * Generate random UUID or GUID string
1274 EXAMPLE: If you want all functions except of network
1275 support you can write:
1277 #include "config_cmd_all.h"
1278 #undef CONFIG_CMD_NET
1281 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1283 Note: Don't enable the "icache" and "dcache" commands
1284 (configuration option CONFIG_CMD_CACHE) unless you know
1285 what you (and your U-Boot users) are doing. Data
1286 cache cannot be enabled on systems like the 8xx or
1287 8260 (where accesses to the IMMR region must be
1288 uncached), and it cannot be disabled on all other
1289 systems where we (mis-) use the data cache to hold an
1290 initial stack and some data.
1293 XXX - this list needs to get updated!
1295 - Regular expression support:
1297 If this variable is defined, U-Boot is linked against
1298 the SLRE (Super Light Regular Expression) library,
1299 which adds regex support to some commands, as for
1300 example "env grep" and "setexpr".
1304 If this variable is defined, U-Boot will use a device tree
1305 to configure its devices, instead of relying on statically
1306 compiled #defines in the board file. This option is
1307 experimental and only available on a few boards. The device
1308 tree is available in the global data as gd->fdt_blob.
1310 U-Boot needs to get its device tree from somewhere. This can
1311 be done using one of the two options below:
1314 If this variable is defined, U-Boot will embed a device tree
1315 binary in its image. This device tree file should be in the
1316 board directory and called <soc>-<board>.dts. The binary file
1317 is then picked up in board_init_f() and made available through
1318 the global data structure as gd->blob.
1321 If this variable is defined, U-Boot will build a device tree
1322 binary. It will be called u-boot.dtb. Architecture-specific
1323 code will locate it at run-time. Generally this works by:
1325 cat u-boot.bin u-boot.dtb >image.bin
1327 and in fact, U-Boot does this for you, creating a file called
1328 u-boot-dtb.bin which is useful in the common case. You can
1329 still use the individual files if you need something more
1334 If this variable is defined, it enables watchdog
1335 support for the SoC. There must be support in the SoC
1336 specific code for a watchdog. For the 8xx and 8260
1337 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1338 register. When supported for a specific SoC is
1339 available, then no further board specific code should
1340 be needed to use it.
1343 When using a watchdog circuitry external to the used
1344 SoC, then define this variable and provide board
1345 specific code for the "hw_watchdog_reset" function.
1347 CONFIG_AT91_HW_WDT_TIMEOUT
1348 specify the timeout in seconds. default 2 seconds.
1351 CONFIG_VERSION_VARIABLE
1352 If this variable is defined, an environment variable
1353 named "ver" is created by U-Boot showing the U-Boot
1354 version as printed by the "version" command.
1355 Any change to this variable will be reverted at the
1360 When CONFIG_CMD_DATE is selected, the type of the RTC
1361 has to be selected, too. Define exactly one of the
1364 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1365 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1366 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1367 CONFIG_RTC_MC146818 - use MC146818 RTC
1368 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1369 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1370 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1371 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1372 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1373 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1374 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1375 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1376 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1379 Note that if the RTC uses I2C, then the I2C interface
1380 must also be configured. See I2C Support, below.
1383 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1385 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1386 chip-ngpio pairs that tell the PCA953X driver the number of
1387 pins supported by a particular chip.
1389 Note that if the GPIO device uses I2C, then the I2C interface
1390 must also be configured. See I2C Support, below.
1393 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1394 accesses and can checksum them or write a list of them out
1395 to memory. See the 'iotrace' command for details. This is
1396 useful for testing device drivers since it can confirm that
1397 the driver behaves the same way before and after a code
1398 change. Currently this is supported on sandbox and arm. To
1399 add support for your architecture, add '#include <iotrace.h>'
1400 to the bottom of arch/<arch>/include/asm/io.h and test.
1402 Example output from the 'iotrace stats' command is below.
1403 Note that if the trace buffer is exhausted, the checksum will
1404 still continue to operate.
1407 Start: 10000000 (buffer start address)
1408 Size: 00010000 (buffer size)
1409 Offset: 00000120 (current buffer offset)
1410 Output: 10000120 (start + offset)
1411 Count: 00000018 (number of trace records)
1412 CRC32: 9526fb66 (CRC32 of all trace records)
1414 - Timestamp Support:
1416 When CONFIG_TIMESTAMP is selected, the timestamp
1417 (date and time) of an image is printed by image
1418 commands like bootm or iminfo. This option is
1419 automatically enabled when you select CONFIG_CMD_DATE .
1421 - Partition Labels (disklabels) Supported:
1422 Zero or more of the following:
1423 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1424 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1425 Intel architecture, USB sticks, etc.
1426 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1427 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1428 bootloader. Note 2TB partition limit; see
1430 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1432 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1433 CONFIG_CMD_SCSI) you must configure support for at
1434 least one non-MTD partition type as well.
1437 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1438 board configurations files but used nowhere!
1440 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1441 be performed by calling the function
1442 ide_set_reset(int reset)
1443 which has to be defined in a board specific file
1448 Set this to enable ATAPI support.
1453 Set this to enable support for disks larger than 137GB
1454 Also look at CONFIG_SYS_64BIT_LBA.
1455 Whithout these , LBA48 support uses 32bit variables and will 'only'
1456 support disks up to 2.1TB.
1458 CONFIG_SYS_64BIT_LBA:
1459 When enabled, makes the IDE subsystem use 64bit sector addresses.
1463 At the moment only there is only support for the
1464 SYM53C8XX SCSI controller; define
1465 CONFIG_SCSI_SYM53C8XX to enable it.
1467 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1468 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1469 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1470 maximum numbers of LUNs, SCSI ID's and target
1472 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1474 The environment variable 'scsidevs' is set to the number of
1475 SCSI devices found during the last scan.
1477 - NETWORK Support (PCI):
1479 Support for Intel 8254x/8257x gigabit chips.
1482 Utility code for direct access to the SPI bus on Intel 8257x.
1483 This does not do anything useful unless you set at least one
1484 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1486 CONFIG_E1000_SPI_GENERIC
1487 Allow generic access to the SPI bus on the Intel 8257x, for
1488 example with the "sspi" command.
1491 Management command for E1000 devices. When used on devices
1492 with SPI support you can reprogram the EEPROM from U-Boot.
1494 CONFIG_E1000_FALLBACK_MAC
1495 default MAC for empty EEPROM after production.
1498 Support for Intel 82557/82559/82559ER chips.
1499 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1500 write routine for first time initialisation.
1503 Support for Digital 2114x chips.
1504 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1505 modem chip initialisation (KS8761/QS6611).
1508 Support for National dp83815 chips.
1511 Support for National dp8382[01] gigabit chips.
1513 - NETWORK Support (other):
1515 CONFIG_DRIVER_AT91EMAC
1516 Support for AT91RM9200 EMAC.
1519 Define this to use reduced MII inteface
1521 CONFIG_DRIVER_AT91EMAC_QUIET
1522 If this defined, the driver is quiet.
1523 The driver doen't show link status messages.
1525 CONFIG_CALXEDA_XGMAC
1526 Support for the Calxeda XGMAC device
1529 Support for SMSC's LAN91C96 chips.
1531 CONFIG_LAN91C96_BASE
1532 Define this to hold the physical address
1533 of the LAN91C96's I/O space
1535 CONFIG_LAN91C96_USE_32_BIT
1536 Define this to enable 32 bit addressing
1539 Support for SMSC's LAN91C111 chip
1541 CONFIG_SMC91111_BASE
1542 Define this to hold the physical address
1543 of the device (I/O space)
1545 CONFIG_SMC_USE_32_BIT
1546 Define this if data bus is 32 bits
1548 CONFIG_SMC_USE_IOFUNCS
1549 Define this to use i/o functions instead of macros
1550 (some hardware wont work with macros)
1552 CONFIG_DRIVER_TI_EMAC
1553 Support for davinci emac
1555 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1556 Define this if you have more then 3 PHYs.
1559 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1561 CONFIG_FTGMAC100_EGIGA
1562 Define this to use GE link update with gigabit PHY.
1563 Define this if FTGMAC100 is connected to gigabit PHY.
1564 If your system has 10/100 PHY only, it might not occur
1565 wrong behavior. Because PHY usually return timeout or
1566 useless data when polling gigabit status and gigabit
1567 control registers. This behavior won't affect the
1568 correctnessof 10/100 link speed update.
1571 Support for SMSC's LAN911x and LAN921x chips
1574 Define this to hold the physical address
1575 of the device (I/O space)
1577 CONFIG_SMC911X_32_BIT
1578 Define this if data bus is 32 bits
1580 CONFIG_SMC911X_16_BIT
1581 Define this if data bus is 16 bits. If your processor
1582 automatically converts one 32 bit word to two 16 bit
1583 words you may also try CONFIG_SMC911X_32_BIT.
1586 Support for Renesas on-chip Ethernet controller
1588 CONFIG_SH_ETHER_USE_PORT
1589 Define the number of ports to be used
1591 CONFIG_SH_ETHER_PHY_ADDR
1592 Define the ETH PHY's address
1594 CONFIG_SH_ETHER_CACHE_WRITEBACK
1595 If this option is set, the driver enables cache flush.
1599 Support for PWM modul on the imx6.
1603 Support TPM devices.
1606 Support for i2c bus TPM devices. Only one device
1607 per system is supported at this time.
1609 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1610 Define the the i2c bus number for the TPM device
1612 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1613 Define the TPM's address on the i2c bus
1615 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1616 Define the burst count bytes upper limit
1618 CONFIG_TPM_ATMEL_TWI
1619 Support for Atmel TWI TPM device. Requires I2C support.
1622 Support for generic parallel port TPM devices. Only one device
1623 per system is supported at this time.
1625 CONFIG_TPM_TIS_BASE_ADDRESS
1626 Base address where the generic TPM device is mapped
1627 to. Contemporary x86 systems usually map it at
1631 Add tpm monitor functions.
1632 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1633 provides monitor access to authorized functions.
1636 Define this to enable the TPM support library which provides
1637 functional interfaces to some TPM commands.
1638 Requires support for a TPM device.
1640 CONFIG_TPM_AUTH_SESSIONS
1641 Define this to enable authorized functions in the TPM library.
1642 Requires CONFIG_TPM and CONFIG_SHA1.
1645 At the moment only the UHCI host controller is
1646 supported (PIP405, MIP405, MPC5200); define
1647 CONFIG_USB_UHCI to enable it.
1648 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1649 and define CONFIG_USB_STORAGE to enable the USB
1652 Supported are USB Keyboards and USB Floppy drives
1654 MPC5200 USB requires additional defines:
1656 for 528 MHz Clock: 0x0001bbbb
1660 for differential drivers: 0x00001000
1661 for single ended drivers: 0x00005000
1662 for differential drivers on PSC3: 0x00000100
1663 for single ended drivers on PSC3: 0x00004100
1664 CONFIG_SYS_USB_EVENT_POLL
1665 May be defined to allow interrupt polling
1666 instead of using asynchronous interrupts
1668 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1669 txfilltuning field in the EHCI controller on reset.
1671 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1672 HW module registers.
1675 Define the below if you wish to use the USB console.
1676 Once firmware is rebuilt from a serial console issue the
1677 command "setenv stdin usbtty; setenv stdout usbtty" and
1678 attach your USB cable. The Unix command "dmesg" should print
1679 it has found a new device. The environment variable usbtty
1680 can be set to gserial or cdc_acm to enable your device to
1681 appear to a USB host as a Linux gserial device or a
1682 Common Device Class Abstract Control Model serial device.
1683 If you select usbtty = gserial you should be able to enumerate
1685 # modprobe usbserial vendor=0xVendorID product=0xProductID
1686 else if using cdc_acm, simply setting the environment
1687 variable usbtty to be cdc_acm should suffice. The following
1688 might be defined in YourBoardName.h
1691 Define this to build a UDC device
1694 Define this to have a tty type of device available to
1695 talk to the UDC device
1698 Define this to enable the high speed support for usb
1699 device and usbtty. If this feature is enabled, a routine
1700 int is_usbd_high_speed(void)
1701 also needs to be defined by the driver to dynamically poll
1702 whether the enumeration has succeded at high speed or full
1705 CONFIG_SYS_CONSOLE_IS_IN_ENV
1706 Define this if you want stdin, stdout &/or stderr to
1710 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1711 Derive USB clock from external clock "blah"
1712 - CONFIG_SYS_USB_EXTC_CLK 0x02
1714 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1715 Derive USB clock from brgclk
1716 - CONFIG_SYS_USB_BRG_CLK 0x04
1718 If you have a USB-IF assigned VendorID then you may wish to
1719 define your own vendor specific values either in BoardName.h
1720 or directly in usbd_vendor_info.h. If you don't define
1721 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1722 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1723 should pretend to be a Linux device to it's target host.
1725 CONFIG_USBD_MANUFACTURER
1726 Define this string as the name of your company for
1727 - CONFIG_USBD_MANUFACTURER "my company"
1729 CONFIG_USBD_PRODUCT_NAME
1730 Define this string as the name of your product
1731 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1733 CONFIG_USBD_VENDORID
1734 Define this as your assigned Vendor ID from the USB
1735 Implementors Forum. This *must* be a genuine Vendor ID
1736 to avoid polluting the USB namespace.
1737 - CONFIG_USBD_VENDORID 0xFFFF
1739 CONFIG_USBD_PRODUCTID
1740 Define this as the unique Product ID
1742 - CONFIG_USBD_PRODUCTID 0xFFFF
1744 - ULPI Layer Support:
1745 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1746 the generic ULPI layer. The generic layer accesses the ULPI PHY
1747 via the platform viewport, so you need both the genric layer and
1748 the viewport enabled. Currently only Chipidea/ARC based
1749 viewport is supported.
1750 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1751 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1752 If your ULPI phy needs a different reference clock than the
1753 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1754 the appropriate value in Hz.
1757 The MMC controller on the Intel PXA is supported. To
1758 enable this define CONFIG_MMC. The MMC can be
1759 accessed from the boot prompt by mapping the device
1760 to physical memory similar to flash. Command line is
1761 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1762 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1765 Support for Renesas on-chip MMCIF controller
1767 CONFIG_SH_MMCIF_ADDR
1768 Define the base address of MMCIF registers
1771 Define the clock frequency for MMCIF
1774 Enable the generic MMC driver
1776 CONFIG_SUPPORT_EMMC_BOOT
1777 Enable some additional features of the eMMC boot partitions.
1779 CONFIG_SUPPORT_EMMC_RPMB
1780 Enable the commands for reading, writing and programming the
1781 key for the Replay Protection Memory Block partition in eMMC.
1783 - USB Device Firmware Update (DFU) class support:
1784 CONFIG_USB_FUNCTION_DFU
1785 This enables the USB portion of the DFU USB class
1788 This enables the command "dfu" which is used to have
1789 U-Boot create a DFU class device via USB. This command
1790 requires that the "dfu_alt_info" environment variable be
1791 set and define the alt settings to expose to the host.
1794 This enables support for exposing (e)MMC devices via DFU.
1797 This enables support for exposing NAND devices via DFU.
1800 This enables support for exposing RAM via DFU.
1801 Note: DFU spec refer to non-volatile memory usage, but
1802 allow usages beyond the scope of spec - here RAM usage,
1803 one that would help mostly the developer.
1805 CONFIG_SYS_DFU_DATA_BUF_SIZE
1806 Dfu transfer uses a buffer before writing data to the
1807 raw storage device. Make the size (in bytes) of this buffer
1808 configurable. The size of this buffer is also configurable
1809 through the "dfu_bufsiz" environment variable.
1811 CONFIG_SYS_DFU_MAX_FILE_SIZE
1812 When updating files rather than the raw storage device,
1813 we use a static buffer to copy the file into and then write
1814 the buffer once we've been given the whole file. Define
1815 this to the maximum filesize (in bytes) for the buffer.
1816 Default is 4 MiB if undefined.
1818 DFU_DEFAULT_POLL_TIMEOUT
1819 Poll timeout [ms], is the timeout a device can send to the
1820 host. The host must wait for this timeout before sending
1821 a subsequent DFU_GET_STATUS request to the device.
1823 DFU_MANIFEST_POLL_TIMEOUT
1824 Poll timeout [ms], which the device sends to the host when
1825 entering dfuMANIFEST state. Host waits this timeout, before
1826 sending again an USB request to the device.
1828 - USB Device Android Fastboot support:
1829 CONFIG_USB_FUNCTION_FASTBOOT
1830 This enables the USB part of the fastboot gadget
1833 This enables the command "fastboot" which enables the Android
1834 fastboot mode for the platform's USB device. Fastboot is a USB
1835 protocol for downloading images, flashing and device control
1836 used on Android devices.
1837 See doc/README.android-fastboot for more information.
1839 CONFIG_ANDROID_BOOT_IMAGE
1840 This enables support for booting images which use the Android
1841 image format header.
1843 CONFIG_FASTBOOT_BUF_ADDR
1844 The fastboot protocol requires a large memory buffer for
1845 downloads. Define this to the starting RAM address to use for
1848 CONFIG_FASTBOOT_BUF_SIZE
1849 The fastboot protocol requires a large memory buffer for
1850 downloads. This buffer should be as large as possible for a
1851 platform. Define this to the size available RAM for fastboot.
1853 CONFIG_FASTBOOT_FLASH
1854 The fastboot protocol includes a "flash" command for writing
1855 the downloaded image to a non-volatile storage device. Define
1856 this to enable the "fastboot flash" command.
1858 CONFIG_FASTBOOT_FLASH_MMC_DEV
1859 The fastboot "flash" command requires additional information
1860 regarding the non-volatile storage device. Define this to
1861 the eMMC device that fastboot should use to store the image.
1863 CONFIG_FASTBOOT_GPT_NAME
1864 The fastboot "flash" command supports writing the downloaded
1865 image to the Protective MBR and the Primary GUID Partition
1866 Table. (Additionally, this downloaded image is post-processed
1867 to generate and write the Backup GUID Partition Table.)
1868 This occurs when the specified "partition name" on the
1869 "fastboot flash" command line matches this value.
1870 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1872 - Journaling Flash filesystem support:
1873 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1874 CONFIG_JFFS2_NAND_DEV
1875 Define these for a default partition on a NAND device
1877 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1878 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1879 Define these for a default partition on a NOR device
1881 CONFIG_SYS_JFFS_CUSTOM_PART
1882 Define this to create an own partition. You have to provide a
1883 function struct part_info* jffs2_part_info(int part_num)
1885 If you define only one JFFS2 partition you may also want to
1886 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1887 to disable the command chpart. This is the default when you
1888 have not defined a custom partition
1890 - FAT(File Allocation Table) filesystem write function support:
1893 Define this to enable support for saving memory data as a
1894 file in FAT formatted partition.
1896 This will also enable the command "fatwrite" enabling the
1897 user to write files to FAT.
1899 CBFS (Coreboot Filesystem) support
1902 Define this to enable support for reading from a Coreboot
1903 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1906 - FAT(File Allocation Table) filesystem cluster size:
1907 CONFIG_FS_FAT_MAX_CLUSTSIZE
1909 Define the max cluster size for fat operations else
1910 a default value of 65536 will be defined.
1915 Define this to enable standard (PC-Style) keyboard
1919 Standard PC keyboard driver with US (is default) and
1920 GERMAN key layout (switch via environment 'keymap=de') support.
1921 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1922 for cfb_console. Supports cursor blinking.
1925 Enables a Chrome OS keyboard using the CROS_EC interface.
1926 This uses CROS_EC to communicate with a second microcontroller
1927 which provides key scans on request.
1932 Define this to enable video support (for output to
1935 CONFIG_VIDEO_CT69000
1937 Enable Chips & Technologies 69000 Video chip
1939 CONFIG_VIDEO_SMI_LYNXEM
1940 Enable Silicon Motion SMI 712/710/810 Video chip. The
1941 video output is selected via environment 'videoout'
1942 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1945 For the CT69000 and SMI_LYNXEM drivers, videomode is
1946 selected via environment 'videomode'. Two different ways
1948 - "videomode=num" 'num' is a standard LiLo mode numbers.
1949 Following standard modes are supported (* is default):
1951 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1952 -------------+---------------------------------------------
1953 8 bits | 0x301* 0x303 0x305 0x161 0x307
1954 15 bits | 0x310 0x313 0x316 0x162 0x319
1955 16 bits | 0x311 0x314 0x317 0x163 0x31A
1956 24 bits | 0x312 0x315 0x318 ? 0x31B
1957 -------------+---------------------------------------------
1958 (i.e. setenv videomode 317; saveenv; reset;)
1960 - "videomode=bootargs" all the video parameters are parsed
1961 from the bootargs. (See drivers/video/videomodes.c)
1964 CONFIG_VIDEO_SED13806
1965 Enable Epson SED13806 driver. This driver supports 8bpp
1966 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1967 or CONFIG_VIDEO_SED13806_16BPP
1970 Enable the Freescale DIU video driver. Reference boards for
1971 SOCs that have a DIU should define this macro to enable DIU
1972 support, and should also define these other macros:
1978 CONFIG_VIDEO_SW_CURSOR
1979 CONFIG_VGA_AS_SINGLE_DEVICE
1981 CONFIG_VIDEO_BMP_LOGO
1983 The DIU driver will look for the 'video-mode' environment
1984 variable, and if defined, enable the DIU as a console during
1985 boot. See the documentation file README.video for a
1986 description of this variable.
1992 Define this to enable a custom keyboard support.
1993 This simply calls drv_keyboard_init() which must be
1994 defined in your board-specific files.
1995 The only board using this so far is RBC823.
1997 - LCD Support: CONFIG_LCD
1999 Define this to enable LCD support (for output to LCD
2000 display); also select one of the supported displays
2001 by defining one of these:
2005 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2007 CONFIG_NEC_NL6448AC33:
2009 NEC NL6448AC33-18. Active, color, single scan.
2011 CONFIG_NEC_NL6448BC20
2013 NEC NL6448BC20-08. 6.5", 640x480.
2014 Active, color, single scan.
2016 CONFIG_NEC_NL6448BC33_54
2018 NEC NL6448BC33-54. 10.4", 640x480.
2019 Active, color, single scan.
2023 Sharp 320x240. Active, color, single scan.
2024 It isn't 16x9, and I am not sure what it is.
2026 CONFIG_SHARP_LQ64D341
2028 Sharp LQ64D341 display, 640x480.
2029 Active, color, single scan.
2033 HLD1045 display, 640x480.
2034 Active, color, single scan.
2038 Optrex CBL50840-2 NF-FW 99 22 M5
2040 Hitachi LMG6912RPFC-00T
2044 320x240. Black & white.
2046 Normally display is black on white background; define
2047 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2049 CONFIG_LCD_ALIGNMENT
2051 Normally the LCD is page-aligned (typically 4KB). If this is
2052 defined then the LCD will be aligned to this value instead.
2053 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2054 here, since it is cheaper to change data cache settings on
2055 a per-section basis.
2057 CONFIG_CONSOLE_SCROLL_LINES
2059 When the console need to be scrolled, this is the number of
2060 lines to scroll by. It defaults to 1. Increasing this makes
2061 the console jump but can help speed up operation when scrolling
2066 Sometimes, for example if the display is mounted in portrait
2067 mode or even if it's mounted landscape but rotated by 180degree,
2068 we need to rotate our content of the display relative to the
2069 framebuffer, so that user can read the messages which are
2071 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2072 initialized with a given rotation from "vl_rot" out of
2073 "vidinfo_t" which is provided by the board specific code.
2074 The value for vl_rot is coded as following (matching to
2075 fbcon=rotate:<n> linux-kernel commandline):
2076 0 = no rotation respectively 0 degree
2077 1 = 90 degree rotation
2078 2 = 180 degree rotation
2079 3 = 270 degree rotation
2081 If CONFIG_LCD_ROTATION is not defined, the console will be
2082 initialized with 0degree rotation.
2086 Support drawing of RLE8-compressed bitmaps on the LCD.
2090 Enables an 'i2c edid' command which can read EDID
2091 information over I2C from an attached LCD display.
2093 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2095 If this option is set, the environment is checked for
2096 a variable "splashimage". If found, the usual display
2097 of logo, copyright and system information on the LCD
2098 is suppressed and the BMP image at the address
2099 specified in "splashimage" is loaded instead. The
2100 console is redirected to the "nulldev", too. This
2101 allows for a "silent" boot where a splash screen is
2102 loaded very quickly after power-on.
2104 CONFIG_SPLASHIMAGE_GUARD
2106 If this option is set, then U-Boot will prevent the environment
2107 variable "splashimage" from being set to a problematic address
2108 (see README.displaying-bmps).
2109 This option is useful for targets where, due to alignment
2110 restrictions, an improperly aligned BMP image will cause a data
2111 abort. If you think you will not have problems with unaligned
2112 accesses (for example because your toolchain prevents them)
2113 there is no need to set this option.
2115 CONFIG_SPLASH_SCREEN_ALIGN
2117 If this option is set the splash image can be freely positioned
2118 on the screen. Environment variable "splashpos" specifies the
2119 position as "x,y". If a positive number is given it is used as
2120 number of pixel from left/top. If a negative number is given it
2121 is used as number of pixel from right/bottom. You can also
2122 specify 'm' for centering the image.
2125 setenv splashpos m,m
2126 => image at center of screen
2128 setenv splashpos 30,20
2129 => image at x = 30 and y = 20
2131 setenv splashpos -10,m
2132 => vertically centered image
2133 at x = dspWidth - bmpWidth - 9
2135 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2137 If this option is set, additionally to standard BMP
2138 images, gzipped BMP images can be displayed via the
2139 splashscreen support or the bmp command.
2141 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2143 If this option is set, 8-bit RLE compressed BMP images
2144 can be displayed via the splashscreen support or the
2147 - Do compressing for memory range:
2150 If this option is set, it would use zlib deflate method
2151 to compress the specified memory at its best effort.
2153 - Compression support:
2156 Enabled by default to support gzip compressed images.
2160 If this option is set, support for bzip2 compressed
2161 images is included. If not, only uncompressed and gzip
2162 compressed images are supported.
2164 NOTE: the bzip2 algorithm requires a lot of RAM, so
2165 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2170 If this option is set, support for lzma compressed
2173 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2174 requires an amount of dynamic memory that is given by the
2177 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2179 Where lc and lp stand for, respectively, Literal context bits
2180 and Literal pos bits.
2182 This value is upper-bounded by 14MB in the worst case. Anyway,
2183 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2184 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2185 a very small buffer.
2187 Use the lzmainfo tool to determinate the lc and lp values and
2188 then calculate the amount of needed dynamic memory (ensuring
2189 the appropriate CONFIG_SYS_MALLOC_LEN value).
2193 If this option is set, support for LZO compressed images
2199 The address of PHY on MII bus.
2201 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2203 The clock frequency of the MII bus
2207 If this option is set, support for speed/duplex
2208 detection of gigabit PHY is included.
2210 CONFIG_PHY_RESET_DELAY
2212 Some PHY like Intel LXT971A need extra delay after
2213 reset before any MII register access is possible.
2214 For such PHY, set this option to the usec delay
2215 required. (minimum 300usec for LXT971A)
2217 CONFIG_PHY_CMD_DELAY (ppc4xx)
2219 Some PHY like Intel LXT971A need extra delay after
2220 command issued before MII status register can be read
2225 Define a default value for the IP address to use for
2226 the default Ethernet interface, in case this is not
2227 determined through e.g. bootp.
2228 (Environment variable "ipaddr")
2230 - Server IP address:
2233 Defines a default value for the IP address of a TFTP
2234 server to contact when using the "tftboot" command.
2235 (Environment variable "serverip")
2237 CONFIG_KEEP_SERVERADDR
2239 Keeps the server's MAC address, in the env 'serveraddr'
2240 for passing to bootargs (like Linux's netconsole option)
2242 - Gateway IP address:
2245 Defines a default value for the IP address of the
2246 default router where packets to other networks are
2248 (Environment variable "gatewayip")
2253 Defines a default value for the subnet mask (or
2254 routing prefix) which is used to determine if an IP
2255 address belongs to the local subnet or needs to be
2256 forwarded through a router.
2257 (Environment variable "netmask")
2259 - Multicast TFTP Mode:
2262 Defines whether you want to support multicast TFTP as per
2263 rfc-2090; for example to work with atftp. Lets lots of targets
2264 tftp down the same boot image concurrently. Note: the Ethernet
2265 driver in use must provide a function: mcast() to join/leave a
2268 - BOOTP Recovery Mode:
2269 CONFIG_BOOTP_RANDOM_DELAY
2271 If you have many targets in a network that try to
2272 boot using BOOTP, you may want to avoid that all
2273 systems send out BOOTP requests at precisely the same
2274 moment (which would happen for instance at recovery
2275 from a power failure, when all systems will try to
2276 boot, thus flooding the BOOTP server. Defining
2277 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2278 inserted before sending out BOOTP requests. The
2279 following delays are inserted then:
2281 1st BOOTP request: delay 0 ... 1 sec
2282 2nd BOOTP request: delay 0 ... 2 sec
2283 3rd BOOTP request: delay 0 ... 4 sec
2285 BOOTP requests: delay 0 ... 8 sec
2287 CONFIG_BOOTP_ID_CACHE_SIZE
2289 BOOTP packets are uniquely identified using a 32-bit ID. The
2290 server will copy the ID from client requests to responses and
2291 U-Boot will use this to determine if it is the destination of
2292 an incoming response. Some servers will check that addresses
2293 aren't in use before handing them out (usually using an ARP
2294 ping) and therefore take up to a few hundred milliseconds to
2295 respond. Network congestion may also influence the time it
2296 takes for a response to make it back to the client. If that
2297 time is too long, U-Boot will retransmit requests. In order
2298 to allow earlier responses to still be accepted after these
2299 retransmissions, U-Boot's BOOTP client keeps a small cache of
2300 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2301 cache. The default is to keep IDs for up to four outstanding
2302 requests. Increasing this will allow U-Boot to accept offers
2303 from a BOOTP client in networks with unusually high latency.
2305 - BOOTP Random transaction ID:
2306 CONFIG_BOOTP_RANDOM_ID
2308 The standard algorithm to generate a DHCP/BOOTP transaction ID
2309 by using the MAC address and the current time stamp may not
2310 quite unlikely produce duplicate transaction IDs from different
2311 clients in the same network. This option creates a transaction
2312 ID using the rand() function. Provided that the RNG has been
2313 seeded well, this should guarantee unique transaction IDs
2316 - DHCP Advanced Options:
2317 You can fine tune the DHCP functionality by defining
2318 CONFIG_BOOTP_* symbols:
2320 CONFIG_BOOTP_SUBNETMASK
2321 CONFIG_BOOTP_GATEWAY
2322 CONFIG_BOOTP_HOSTNAME
2323 CONFIG_BOOTP_NISDOMAIN
2324 CONFIG_BOOTP_BOOTPATH
2325 CONFIG_BOOTP_BOOTFILESIZE
2328 CONFIG_BOOTP_SEND_HOSTNAME
2329 CONFIG_BOOTP_NTPSERVER
2330 CONFIG_BOOTP_TIMEOFFSET
2331 CONFIG_BOOTP_VENDOREX
2332 CONFIG_BOOTP_MAY_FAIL
2334 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2335 environment variable, not the BOOTP server.
2337 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2338 after the configured retry count, the call will fail
2339 instead of starting over. This can be used to fail over
2340 to Link-local IP address configuration if the DHCP server
2343 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2344 serverip from a DHCP server, it is possible that more
2345 than one DNS serverip is offered to the client.
2346 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2347 serverip will be stored in the additional environment
2348 variable "dnsip2". The first DNS serverip is always
2349 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2352 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2353 to do a dynamic update of a DNS server. To do this, they
2354 need the hostname of the DHCP requester.
2355 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2356 of the "hostname" environment variable is passed as
2357 option 12 to the DHCP server.
2359 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2361 A 32bit value in microseconds for a delay between
2362 receiving a "DHCP Offer" and sending the "DHCP Request".
2363 This fixes a problem with certain DHCP servers that don't
2364 respond 100% of the time to a "DHCP request". E.g. On an
2365 AT91RM9200 processor running at 180MHz, this delay needed
2366 to be *at least* 15,000 usec before a Windows Server 2003
2367 DHCP server would reply 100% of the time. I recommend at
2368 least 50,000 usec to be safe. The alternative is to hope
2369 that one of the retries will be successful but note that
2370 the DHCP timeout and retry process takes a longer than
2373 - Link-local IP address negotiation:
2374 Negotiate with other link-local clients on the local network
2375 for an address that doesn't require explicit configuration.
2376 This is especially useful if a DHCP server cannot be guaranteed
2377 to exist in all environments that the device must operate.
2379 See doc/README.link-local for more information.
2382 CONFIG_CDP_DEVICE_ID
2384 The device id used in CDP trigger frames.
2386 CONFIG_CDP_DEVICE_ID_PREFIX
2388 A two character string which is prefixed to the MAC address
2393 A printf format string which contains the ascii name of
2394 the port. Normally is set to "eth%d" which sets
2395 eth0 for the first Ethernet, eth1 for the second etc.
2397 CONFIG_CDP_CAPABILITIES
2399 A 32bit integer which indicates the device capabilities;
2400 0x00000010 for a normal host which does not forwards.
2404 An ascii string containing the version of the software.
2408 An ascii string containing the name of the platform.
2412 A 32bit integer sent on the trigger.
2414 CONFIG_CDP_POWER_CONSUMPTION
2416 A 16bit integer containing the power consumption of the
2417 device in .1 of milliwatts.
2419 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2421 A byte containing the id of the VLAN.
2423 - Status LED: CONFIG_STATUS_LED
2425 Several configurations allow to display the current
2426 status using a LED. For instance, the LED will blink
2427 fast while running U-Boot code, stop blinking as
2428 soon as a reply to a BOOTP request was received, and
2429 start blinking slow once the Linux kernel is running
2430 (supported by a status LED driver in the Linux
2431 kernel). Defining CONFIG_STATUS_LED enables this
2437 The status LED can be connected to a GPIO pin.
2438 In such cases, the gpio_led driver can be used as a
2439 status LED backend implementation. Define CONFIG_GPIO_LED
2440 to include the gpio_led driver in the U-Boot binary.
2442 CONFIG_GPIO_LED_INVERTED_TABLE
2443 Some GPIO connected LEDs may have inverted polarity in which
2444 case the GPIO high value corresponds to LED off state and
2445 GPIO low value corresponds to LED on state.
2446 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2447 with a list of GPIO LEDs that have inverted polarity.
2449 - CAN Support: CONFIG_CAN_DRIVER
2451 Defining CONFIG_CAN_DRIVER enables CAN driver support
2452 on those systems that support this (optional)
2453 feature, like the TQM8xxL modules.
2455 - I2C Support: CONFIG_SYS_I2C
2457 This enable the NEW i2c subsystem, and will allow you to use
2458 i2c commands at the u-boot command line (as long as you set
2459 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2460 based realtime clock chips or other i2c devices. See
2461 common/cmd_i2c.c for a description of the command line
2464 ported i2c driver to the new framework:
2465 - drivers/i2c/soft_i2c.c:
2466 - activate first bus with CONFIG_SYS_I2C_SOFT define
2467 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2468 for defining speed and slave address
2469 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2470 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2471 for defining speed and slave address
2472 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2473 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2474 for defining speed and slave address
2475 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2476 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2477 for defining speed and slave address
2479 - drivers/i2c/fsl_i2c.c:
2480 - activate i2c driver with CONFIG_SYS_I2C_FSL
2481 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2482 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2483 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2485 - If your board supports a second fsl i2c bus, define
2486 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2487 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2488 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2491 - drivers/i2c/tegra_i2c.c:
2492 - activate this driver with CONFIG_SYS_I2C_TEGRA
2493 - This driver adds 4 i2c buses with a fix speed from
2494 100000 and the slave addr 0!
2496 - drivers/i2c/ppc4xx_i2c.c
2497 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2498 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2499 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2501 - drivers/i2c/i2c_mxc.c
2502 - activate this driver with CONFIG_SYS_I2C_MXC
2503 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2504 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2505 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2506 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2507 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2508 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2509 If those defines are not set, default value is 100000
2510 for speed, and 0 for slave.
2511 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2512 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2514 - drivers/i2c/rcar_i2c.c:
2515 - activate this driver with CONFIG_SYS_I2C_RCAR
2516 - This driver adds 4 i2c buses
2518 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2519 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2520 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2521 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2522 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2523 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2524 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2525 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2526 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2528 - drivers/i2c/sh_i2c.c:
2529 - activate this driver with CONFIG_SYS_I2C_SH
2530 - This driver adds from 2 to 5 i2c buses
2532 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2533 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2534 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2535 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2536 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2537 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2538 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2539 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2540 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2541 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2542 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2543 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2544 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2546 - drivers/i2c/omap24xx_i2c.c
2547 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2548 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2549 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2550 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2551 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2552 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2553 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2554 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2555 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2556 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2557 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2559 - drivers/i2c/zynq_i2c.c
2560 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2561 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2562 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2564 - drivers/i2c/s3c24x0_i2c.c:
2565 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2566 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2567 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2568 with a fix speed from 100000 and the slave addr 0!
2570 - drivers/i2c/ihs_i2c.c
2571 - activate this driver with CONFIG_SYS_I2C_IHS
2572 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2573 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2574 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2575 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2576 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2577 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2578 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2579 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2580 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2581 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2582 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2583 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2587 CONFIG_SYS_NUM_I2C_BUSES
2588 Hold the number of i2c buses you want to use. If you
2589 don't use/have i2c muxes on your i2c bus, this
2590 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2593 CONFIG_SYS_I2C_DIRECT_BUS
2594 define this, if you don't use i2c muxes on your hardware.
2595 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2598 CONFIG_SYS_I2C_MAX_HOPS
2599 define how many muxes are maximal consecutively connected
2600 on one i2c bus. If you not use i2c muxes, omit this
2603 CONFIG_SYS_I2C_BUSES
2604 hold a list of buses you want to use, only used if
2605 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2606 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2607 CONFIG_SYS_NUM_I2C_BUSES = 9:
2609 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2610 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2612 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2613 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2614 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2615 {1, {I2C_NULL_HOP}}, \
2616 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2617 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2621 bus 0 on adapter 0 without a mux
2622 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2623 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2624 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2625 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2626 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2627 bus 6 on adapter 1 without a mux
2628 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2629 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2631 If you do not have i2c muxes on your board, omit this define.
2633 - Legacy I2C Support: CONFIG_HARD_I2C
2635 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2636 provides the following compelling advantages:
2638 - more than one i2c adapter is usable
2639 - approved multibus support
2640 - better i2c mux support
2642 ** Please consider updating your I2C driver now. **
2644 These enable legacy I2C serial bus commands. Defining
2645 CONFIG_HARD_I2C will include the appropriate I2C driver
2646 for the selected CPU.
2648 This will allow you to use i2c commands at the u-boot
2649 command line (as long as you set CONFIG_CMD_I2C in
2650 CONFIG_COMMANDS) and communicate with i2c based realtime
2651 clock chips. See common/cmd_i2c.c for a description of the
2652 command line interface.
2654 CONFIG_HARD_I2C selects a hardware I2C controller.
2656 There are several other quantities that must also be
2657 defined when you define CONFIG_HARD_I2C.
2659 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2660 to be the frequency (in Hz) at which you wish your i2c bus
2661 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2662 the CPU's i2c node address).
2664 Now, the u-boot i2c code for the mpc8xx
2665 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2666 and so its address should therefore be cleared to 0 (See,
2667 eg, MPC823e User's Manual p.16-473). So, set
2668 CONFIG_SYS_I2C_SLAVE to 0.
2670 CONFIG_SYS_I2C_INIT_MPC5XXX
2672 When a board is reset during an i2c bus transfer
2673 chips might think that the current transfer is still
2674 in progress. Reset the slave devices by sending start
2675 commands until the slave device responds.
2677 That's all that's required for CONFIG_HARD_I2C.
2679 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2680 then the following macros need to be defined (examples are
2681 from include/configs/lwmon.h):
2685 (Optional). Any commands necessary to enable the I2C
2686 controller or configure ports.
2688 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2692 (Only for MPC8260 CPU). The I/O port to use (the code
2693 assumes both bits are on the same port). Valid values
2694 are 0..3 for ports A..D.
2698 The code necessary to make the I2C data line active
2699 (driven). If the data line is open collector, this
2702 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2706 The code necessary to make the I2C data line tri-stated
2707 (inactive). If the data line is open collector, this
2710 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2714 Code that returns true if the I2C data line is high,
2717 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2721 If <bit> is true, sets the I2C data line high. If it
2722 is false, it clears it (low).
2724 eg: #define I2C_SDA(bit) \
2725 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2726 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2730 If <bit> is true, sets the I2C clock line high. If it
2731 is false, it clears it (low).
2733 eg: #define I2C_SCL(bit) \
2734 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2735 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2739 This delay is invoked four times per clock cycle so this
2740 controls the rate of data transfer. The data rate thus
2741 is 1 / (I2C_DELAY * 4). Often defined to be something
2744 #define I2C_DELAY udelay(2)
2746 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2748 If your arch supports the generic GPIO framework (asm/gpio.h),
2749 then you may alternatively define the two GPIOs that are to be
2750 used as SCL / SDA. Any of the previous I2C_xxx macros will
2751 have GPIO-based defaults assigned to them as appropriate.
2753 You should define these to the GPIO value as given directly to
2754 the generic GPIO functions.
2756 CONFIG_SYS_I2C_INIT_BOARD
2758 When a board is reset during an i2c bus transfer
2759 chips might think that the current transfer is still
2760 in progress. On some boards it is possible to access
2761 the i2c SCLK line directly, either by using the
2762 processor pin as a GPIO or by having a second pin
2763 connected to the bus. If this option is defined a
2764 custom i2c_init_board() routine in boards/xxx/board.c
2765 is run early in the boot sequence.
2767 CONFIG_SYS_I2C_BOARD_LATE_INIT
2769 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2770 defined a custom i2c_board_late_init() routine in
2771 boards/xxx/board.c is run AFTER the operations in i2c_init()
2772 is completed. This callpoint can be used to unreset i2c bus
2773 using CPU i2c controller register accesses for CPUs whose i2c
2774 controller provide such a method. It is called at the end of
2775 i2c_init() to allow i2c_init operations to setup the i2c bus
2776 controller on the CPU (e.g. setting bus speed & slave address).
2778 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2780 This option enables configuration of bi_iic_fast[] flags
2781 in u-boot bd_info structure based on u-boot environment
2782 variable "i2cfast". (see also i2cfast)
2784 CONFIG_I2C_MULTI_BUS
2786 This option allows the use of multiple I2C buses, each of which
2787 must have a controller. At any point in time, only one bus is
2788 active. To switch to a different bus, use the 'i2c dev' command.
2789 Note that bus numbering is zero-based.
2791 CONFIG_SYS_I2C_NOPROBES
2793 This option specifies a list of I2C devices that will be skipped
2794 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2795 is set, specify a list of bus-device pairs. Otherwise, specify
2796 a 1D array of device addresses
2799 #undef CONFIG_I2C_MULTI_BUS
2800 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2802 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2804 #define CONFIG_I2C_MULTI_BUS
2805 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2807 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2809 CONFIG_SYS_SPD_BUS_NUM
2811 If defined, then this indicates the I2C bus number for DDR SPD.
2812 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2814 CONFIG_SYS_RTC_BUS_NUM
2816 If defined, then this indicates the I2C bus number for the RTC.
2817 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2819 CONFIG_SYS_DTT_BUS_NUM
2821 If defined, then this indicates the I2C bus number for the DTT.
2822 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2824 CONFIG_SYS_I2C_DTT_ADDR:
2826 If defined, specifies the I2C address of the DTT device.
2827 If not defined, then U-Boot uses predefined value for
2828 specified DTT device.
2830 CONFIG_SOFT_I2C_READ_REPEATED_START
2832 defining this will force the i2c_read() function in
2833 the soft_i2c driver to perform an I2C repeated start
2834 between writing the address pointer and reading the
2835 data. If this define is omitted the default behaviour
2836 of doing a stop-start sequence will be used. Most I2C
2837 devices can use either method, but some require one or
2840 - SPI Support: CONFIG_SPI
2842 Enables SPI driver (so far only tested with
2843 SPI EEPROM, also an instance works with Crystal A/D and
2844 D/As on the SACSng board)
2848 Enables the driver for SPI controller on SuperH. Currently
2849 only SH7757 is supported.
2853 Enables extended (16-bit) SPI EEPROM addressing.
2854 (symmetrical to CONFIG_I2C_X)
2858 Enables a software (bit-bang) SPI driver rather than
2859 using hardware support. This is a general purpose
2860 driver that only requires three general I/O port pins
2861 (two outputs, one input) to function. If this is
2862 defined, the board configuration must define several
2863 SPI configuration items (port pins to use, etc). For
2864 an example, see include/configs/sacsng.h.
2868 Enables a hardware SPI driver for general-purpose reads
2869 and writes. As with CONFIG_SOFT_SPI, the board configuration
2870 must define a list of chip-select function pointers.
2871 Currently supported on some MPC8xxx processors. For an
2872 example, see include/configs/mpc8349emds.h.
2876 Enables the driver for the SPI controllers on i.MX and MXC
2877 SoCs. Currently i.MX31/35/51 are supported.
2879 CONFIG_SYS_SPI_MXC_WAIT
2880 Timeout for waiting until spi transfer completed.
2881 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2883 - FPGA Support: CONFIG_FPGA
2885 Enables FPGA subsystem.
2887 CONFIG_FPGA_<vendor>
2889 Enables support for specific chip vendors.
2892 CONFIG_FPGA_<family>
2894 Enables support for FPGA family.
2895 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2899 Specify the number of FPGA devices to support.
2901 CONFIG_CMD_FPGA_LOADMK
2903 Enable support for fpga loadmk command
2905 CONFIG_CMD_FPGA_LOADP
2907 Enable support for fpga loadp command - load partial bitstream
2909 CONFIG_CMD_FPGA_LOADBP
2911 Enable support for fpga loadbp command - load partial bitstream
2914 CONFIG_SYS_FPGA_PROG_FEEDBACK
2916 Enable printing of hash marks during FPGA configuration.
2918 CONFIG_SYS_FPGA_CHECK_BUSY
2920 Enable checks on FPGA configuration interface busy
2921 status by the configuration function. This option
2922 will require a board or device specific function to
2927 If defined, a function that provides delays in the FPGA
2928 configuration driver.
2930 CONFIG_SYS_FPGA_CHECK_CTRLC
2931 Allow Control-C to interrupt FPGA configuration
2933 CONFIG_SYS_FPGA_CHECK_ERROR
2935 Check for configuration errors during FPGA bitfile
2936 loading. For example, abort during Virtex II
2937 configuration if the INIT_B line goes low (which
2938 indicated a CRC error).
2940 CONFIG_SYS_FPGA_WAIT_INIT
2942 Maximum time to wait for the INIT_B line to de-assert
2943 after PROB_B has been de-asserted during a Virtex II
2944 FPGA configuration sequence. The default time is 500
2947 CONFIG_SYS_FPGA_WAIT_BUSY
2949 Maximum time to wait for BUSY to de-assert during
2950 Virtex II FPGA configuration. The default is 5 ms.
2952 CONFIG_SYS_FPGA_WAIT_CONFIG
2954 Time to wait after FPGA configuration. The default is
2957 - Configuration Management:
2960 Some SoCs need special image types (e.g. U-Boot binary
2961 with a special header) as build targets. By defining
2962 CONFIG_BUILD_TARGET in the SoC / board header, this
2963 special image will be automatically built upon calling
2968 If defined, this string will be added to the U-Boot
2969 version information (U_BOOT_VERSION)
2971 - Vendor Parameter Protection:
2973 U-Boot considers the values of the environment
2974 variables "serial#" (Board Serial Number) and
2975 "ethaddr" (Ethernet Address) to be parameters that
2976 are set once by the board vendor / manufacturer, and
2977 protects these variables from casual modification by
2978 the user. Once set, these variables are read-only,
2979 and write or delete attempts are rejected. You can
2980 change this behaviour:
2982 If CONFIG_ENV_OVERWRITE is #defined in your config
2983 file, the write protection for vendor parameters is
2984 completely disabled. Anybody can change or delete
2987 Alternatively, if you define _both_ an ethaddr in the
2988 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2989 Ethernet address is installed in the environment,
2990 which can be changed exactly ONCE by the user. [The
2991 serial# is unaffected by this, i. e. it remains
2994 The same can be accomplished in a more flexible way
2995 for any variable by configuring the type of access
2996 to allow for those variables in the ".flags" variable
2997 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3002 Define this variable to enable the reservation of
3003 "protected RAM", i. e. RAM which is not overwritten
3004 by U-Boot. Define CONFIG_PRAM to hold the number of
3005 kB you want to reserve for pRAM. You can overwrite
3006 this default value by defining an environment
3007 variable "pram" to the number of kB you want to
3008 reserve. Note that the board info structure will
3009 still show the full amount of RAM. If pRAM is
3010 reserved, a new environment variable "mem" will
3011 automatically be defined to hold the amount of
3012 remaining RAM in a form that can be passed as boot
3013 argument to Linux, for instance like that:
3015 setenv bootargs ... mem=\${mem}
3018 This way you can tell Linux not to use this memory,
3019 either, which results in a memory region that will
3020 not be affected by reboots.
3022 *WARNING* If your board configuration uses automatic
3023 detection of the RAM size, you must make sure that
3024 this memory test is non-destructive. So far, the
3025 following board configurations are known to be
3028 IVMS8, IVML24, SPD8xx, TQM8xxL,
3029 HERMES, IP860, RPXlite, LWMON,
3032 - Access to physical memory region (> 4GB)
3033 Some basic support is provided for operations on memory not
3034 normally accessible to U-Boot - e.g. some architectures
3035 support access to more than 4GB of memory on 32-bit
3036 machines using physical address extension or similar.
3037 Define CONFIG_PHYSMEM to access this basic support, which
3038 currently only supports clearing the memory.
3043 Define this variable to stop the system in case of a
3044 fatal error, so that you have to reset it manually.
3045 This is probably NOT a good idea for an embedded
3046 system where you want the system to reboot
3047 automatically as fast as possible, but it may be
3048 useful during development since you can try to debug
3049 the conditions that lead to the situation.
3051 CONFIG_NET_RETRY_COUNT
3053 This variable defines the number of retries for
3054 network operations like ARP, RARP, TFTP, or BOOTP
3055 before giving up the operation. If not defined, a
3056 default value of 5 is used.
3060 Timeout waiting for an ARP reply in milliseconds.
3064 Timeout in milliseconds used in NFS protocol.
3065 If you encounter "ERROR: Cannot umount" in nfs command,
3066 try longer timeout such as
3067 #define CONFIG_NFS_TIMEOUT 10000UL
3069 - Command Interpreter:
3070 CONFIG_AUTO_COMPLETE
3072 Enable auto completion of commands using TAB.
3074 CONFIG_SYS_PROMPT_HUSH_PS2
3076 This defines the secondary prompt string, which is
3077 printed when the command interpreter needs more input
3078 to complete a command. Usually "> ".
3082 In the current implementation, the local variables
3083 space and global environment variables space are
3084 separated. Local variables are those you define by
3085 simply typing `name=value'. To access a local
3086 variable later on, you have write `$name' or
3087 `${name}'; to execute the contents of a variable
3088 directly type `$name' at the command prompt.
3090 Global environment variables are those you use
3091 setenv/printenv to work with. To run a command stored
3092 in such a variable, you need to use the run command,
3093 and you must not use the '$' sign to access them.
3095 To store commands and special characters in a
3096 variable, please use double quotation marks
3097 surrounding the whole text of the variable, instead
3098 of the backslashes before semicolons and special
3101 - Command Line Editing and History:
3102 CONFIG_CMDLINE_EDITING
3104 Enable editing and History functions for interactive
3105 command line input operations
3107 - Default Environment:
3108 CONFIG_EXTRA_ENV_SETTINGS
3110 Define this to contain any number of null terminated
3111 strings (variable = value pairs) that will be part of
3112 the default environment compiled into the boot image.
3114 For example, place something like this in your
3115 board's config file:
3117 #define CONFIG_EXTRA_ENV_SETTINGS \
3121 Warning: This method is based on knowledge about the
3122 internal format how the environment is stored by the
3123 U-Boot code. This is NOT an official, exported
3124 interface! Although it is unlikely that this format
3125 will change soon, there is no guarantee either.
3126 You better know what you are doing here.
3128 Note: overly (ab)use of the default environment is
3129 discouraged. Make sure to check other ways to preset
3130 the environment like the "source" command or the
3133 CONFIG_ENV_VARS_UBOOT_CONFIG
3135 Define this in order to add variables describing the
3136 U-Boot build configuration to the default environment.
3137 These will be named arch, cpu, board, vendor, and soc.
3139 Enabling this option will cause the following to be defined:
3147 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3149 Define this in order to add variables describing certain
3150 run-time determined information about the hardware to the
3151 environment. These will be named board_name, board_rev.
3153 CONFIG_DELAY_ENVIRONMENT
3155 Normally the environment is loaded when the board is
3156 initialised so that it is available to U-Boot. This inhibits
3157 that so that the environment is not available until
3158 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3159 this is instead controlled by the value of
3160 /config/load-environment.
3162 - Parallel Flash support:
3165 Traditionally U-boot was run on systems with parallel NOR
3166 flash. This option is used to disable support for parallel NOR
3167 flash. This option should be defined if the board does not have
3170 If this option is not defined one of the generic flash drivers
3171 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3172 selected or the board must provide an implementation of the
3173 flash API (see include/flash.h).
3175 - DataFlash Support:
3176 CONFIG_HAS_DATAFLASH
3178 Defining this option enables DataFlash features and
3179 allows to read/write in Dataflash via the standard
3182 - Serial Flash support
3185 Defining this option enables SPI flash commands
3186 'sf probe/read/write/erase/update'.
3188 Usage requires an initial 'probe' to define the serial
3189 flash parameters, followed by read/write/erase/update
3192 The following defaults may be provided by the platform
3193 to handle the common case when only a single serial
3194 flash is present on the system.
3196 CONFIG_SF_DEFAULT_BUS Bus identifier
3197 CONFIG_SF_DEFAULT_CS Chip-select
3198 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3199 CONFIG_SF_DEFAULT_SPEED in Hz
3203 Define this option to include a destructive SPI flash
3206 CONFIG_SF_DUAL_FLASH Dual flash memories
3208 Define this option to use dual flash support where two flash
3209 memories can be connected with a given cs line.
3210 Currently Xilinx Zynq qspi supports these type of connections.
3212 - SystemACE Support:
3215 Adding this option adds support for Xilinx SystemACE
3216 chips attached via some sort of local bus. The address
3217 of the chip must also be defined in the
3218 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3220 #define CONFIG_SYSTEMACE
3221 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3223 When SystemACE support is added, the "ace" device type
3224 becomes available to the fat commands, i.e. fatls.
3226 - TFTP Fixed UDP Port:
3229 If this is defined, the environment variable tftpsrcp
3230 is used to supply the TFTP UDP source port value.
3231 If tftpsrcp isn't defined, the normal pseudo-random port
3232 number generator is used.
3234 Also, the environment variable tftpdstp is used to supply
3235 the TFTP UDP destination port value. If tftpdstp isn't
3236 defined, the normal port 69 is used.
3238 The purpose for tftpsrcp is to allow a TFTP server to
3239 blindly start the TFTP transfer using the pre-configured
3240 target IP address and UDP port. This has the effect of
3241 "punching through" the (Windows XP) firewall, allowing
3242 the remainder of the TFTP transfer to proceed normally.
3243 A better solution is to properly configure the firewall,
3244 but sometimes that is not allowed.
3249 This enables a generic 'hash' command which can produce
3250 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3254 Enable the hash verify command (hash -v). This adds to code
3257 CONFIG_SHA1 - This option enables support of hashing using SHA1
3258 algorithm. The hash is calculated in software.
3259 CONFIG_SHA256 - This option enables support of hashing using
3260 SHA256 algorithm. The hash is calculated in software.
3261 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3262 for SHA1/SHA256 hashing.
3263 This affects the 'hash' command and also the
3264 hash_lookup_algo() function.
3265 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3266 hardware-acceleration for SHA1/SHA256 progressive hashing.
3267 Data can be streamed in a block at a time and the hashing
3268 is performed in hardware.
3270 Note: There is also a sha1sum command, which should perhaps
3271 be deprecated in favour of 'hash sha1'.
3273 - Freescale i.MX specific commands:
3274 CONFIG_CMD_HDMIDETECT
3275 This enables 'hdmidet' command which returns true if an
3276 HDMI monitor is detected. This command is i.MX 6 specific.
3279 This enables the 'bmode' (bootmode) command for forcing
3280 a boot from specific media.
3282 This is useful for forcing the ROM's usb downloader to
3283 activate upon a watchdog reset which is nice when iterating
3284 on U-Boot. Using the reset button or running bmode normal
3285 will set it back to normal. This command currently
3286 supports i.MX53 and i.MX6.
3291 This enables the RSA algorithm used for FIT image verification
3292 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3294 The Modular Exponentiation algorithm in RSA is implemented using
3295 driver model. So CONFIG_DM needs to be enabled by default for this
3296 library to function.
3298 The signing part is build into mkimage regardless of this
3299 option. The software based modular exponentiation is built into
3300 mkimage irrespective of this option.
3302 - bootcount support:
3303 CONFIG_BOOTCOUNT_LIMIT
3305 This enables the bootcounter support, see:
3306 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3309 enable special bootcounter support on at91sam9xe based boards.
3311 enable special bootcounter support on blackfin based boards.
3313 enable special bootcounter support on da850 based boards.
3314 CONFIG_BOOTCOUNT_RAM
3315 enable support for the bootcounter in RAM
3316 CONFIG_BOOTCOUNT_I2C
3317 enable support for the bootcounter on an i2c (like RTC) device.
3318 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3319 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3321 CONFIG_BOOTCOUNT_ALEN = address len
3323 - Show boot progress:
3324 CONFIG_SHOW_BOOT_PROGRESS
3326 Defining this option allows to add some board-
3327 specific code (calling a user-provided function
3328 "show_boot_progress(int)") that enables you to show
3329 the system's boot progress on some display (for
3330 example, some LED's) on your board. At the moment,
3331 the following checkpoints are implemented:
3334 Legacy uImage format:
3337 1 common/cmd_bootm.c before attempting to boot an image
3338 -1 common/cmd_bootm.c Image header has bad magic number
3339 2 common/cmd_bootm.c Image header has correct magic number
3340 -2 common/cmd_bootm.c Image header has bad checksum
3341 3 common/cmd_bootm.c Image header has correct checksum
3342 -3 common/cmd_bootm.c Image data has bad checksum
3343 4 common/cmd_bootm.c Image data has correct checksum
3344 -4 common/cmd_bootm.c Image is for unsupported architecture
3345 5 common/cmd_bootm.c Architecture check OK
3346 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3347 6 common/cmd_bootm.c Image Type check OK
3348 -6 common/cmd_bootm.c gunzip uncompression error
3349 -7 common/cmd_bootm.c Unimplemented compression type
3350 7 common/cmd_bootm.c Uncompression OK
3351 8 common/cmd_bootm.c No uncompress/copy overwrite error
3352 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3354 9 common/image.c Start initial ramdisk verification
3355 -10 common/image.c Ramdisk header has bad magic number
3356 -11 common/image.c Ramdisk header has bad checksum
3357 10 common/image.c Ramdisk header is OK
3358 -12 common/image.c Ramdisk data has bad checksum
3359 11 common/image.c Ramdisk data has correct checksum
3360 12 common/image.c Ramdisk verification complete, start loading
3361 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3362 13 common/image.c Start multifile image verification
3363 14 common/image.c No initial ramdisk, no multifile, continue.
3365 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3367 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3368 -31 post/post.c POST test failed, detected by post_output_backlog()
3369 -32 post/post.c POST test failed, detected by post_run_single()
3371 34 common/cmd_doc.c before loading a Image from a DOC device
3372 -35 common/cmd_doc.c Bad usage of "doc" command
3373 35 common/cmd_doc.c correct usage of "doc" command
3374 -36 common/cmd_doc.c No boot device
3375 36 common/cmd_doc.c correct boot device
3376 -37 common/cmd_doc.c Unknown Chip ID on boot device
3377 37 common/cmd_doc.c correct chip ID found, device available
3378 -38 common/cmd_doc.c Read Error on boot device
3379 38 common/cmd_doc.c reading Image header from DOC device OK
3380 -39 common/cmd_doc.c Image header has bad magic number
3381 39 common/cmd_doc.c Image header has correct magic number
3382 -40 common/cmd_doc.c Error reading Image from DOC device
3383 40 common/cmd_doc.c Image header has correct magic number
3384 41 common/cmd_ide.c before loading a Image from a IDE device
3385 -42 common/cmd_ide.c Bad usage of "ide" command
3386 42 common/cmd_ide.c correct usage of "ide" command
3387 -43 common/cmd_ide.c No boot device
3388 43 common/cmd_ide.c boot device found
3389 -44 common/cmd_ide.c Device not available
3390 44 common/cmd_ide.c Device available
3391 -45 common/cmd_ide.c wrong partition selected
3392 45 common/cmd_ide.c partition selected
3393 -46 common/cmd_ide.c Unknown partition table
3394 46 common/cmd_ide.c valid partition table found
3395 -47 common/cmd_ide.c Invalid partition type
3396 47 common/cmd_ide.c correct partition type
3397 -48 common/cmd_ide.c Error reading Image Header on boot device
3398 48 common/cmd_ide.c reading Image Header from IDE device OK
3399 -49 common/cmd_ide.c Image header has bad magic number
3400 49 common/cmd_ide.c Image header has correct magic number
3401 -50 common/cmd_ide.c Image header has bad checksum
3402 50 common/cmd_ide.c Image header has correct checksum
3403 -51 common/cmd_ide.c Error reading Image from IDE device
3404 51 common/cmd_ide.c reading Image from IDE device OK
3405 52 common/cmd_nand.c before loading a Image from a NAND device
3406 -53 common/cmd_nand.c Bad usage of "nand" command
3407 53 common/cmd_nand.c correct usage of "nand" command
3408 -54 common/cmd_nand.c No boot device
3409 54 common/cmd_nand.c boot device found
3410 -55 common/cmd_nand.c Unknown Chip ID on boot device
3411 55 common/cmd_nand.c correct chip ID found, device available
3412 -56 common/cmd_nand.c Error reading Image Header on boot device
3413 56 common/cmd_nand.c reading Image Header from NAND device OK
3414 -57 common/cmd_nand.c Image header has bad magic number
3415 57 common/cmd_nand.c Image header has correct magic number
3416 -58 common/cmd_nand.c Error reading Image from NAND device
3417 58 common/cmd_nand.c reading Image from NAND device OK
3419 -60 common/env_common.c Environment has a bad CRC, using default
3421 64 net/eth.c starting with Ethernet configuration.
3422 -64 net/eth.c no Ethernet found.
3423 65 net/eth.c Ethernet found.
3425 -80 common/cmd_net.c usage wrong
3426 80 common/cmd_net.c before calling net_loop()
3427 -81 common/cmd_net.c some error in net_loop() occurred
3428 81 common/cmd_net.c net_loop() back without error
3429 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3430 82 common/cmd_net.c trying automatic boot
3431 83 common/cmd_net.c running "source" command
3432 -83 common/cmd_net.c some error in automatic boot or "source" command
3433 84 common/cmd_net.c end without errors
3438 100 common/cmd_bootm.c Kernel FIT Image has correct format
3439 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3440 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3441 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3442 102 common/cmd_bootm.c Kernel unit name specified
3443 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3444 103 common/cmd_bootm.c Found configuration node
3445 104 common/cmd_bootm.c Got kernel subimage node offset
3446 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3447 105 common/cmd_bootm.c Kernel subimage hash verification OK
3448 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3449 106 common/cmd_bootm.c Architecture check OK
3450 -106 common/cmd_bootm.c Kernel subimage has wrong type
3451 107 common/cmd_bootm.c Kernel subimage type OK
3452 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3453 108 common/cmd_bootm.c Got kernel subimage data/size
3454 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3455 -109 common/cmd_bootm.c Can't get kernel subimage type
3456 -110 common/cmd_bootm.c Can't get kernel subimage comp
3457 -111 common/cmd_bootm.c Can't get kernel subimage os
3458 -112 common/cmd_bootm.c Can't get kernel subimage load address
3459 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3461 120 common/image.c Start initial ramdisk verification
3462 -120 common/image.c Ramdisk FIT image has incorrect format
3463 121 common/image.c Ramdisk FIT image has correct format
3464 122 common/image.c No ramdisk subimage unit name, using configuration
3465 -122 common/image.c Can't get configuration for ramdisk subimage
3466 123 common/image.c Ramdisk unit name specified
3467 -124 common/image.c Can't get ramdisk subimage node offset
3468 125 common/image.c Got ramdisk subimage node offset
3469 -125 common/image.c Ramdisk subimage hash verification failed
3470 126 common/image.c Ramdisk subimage hash verification OK
3471 -126 common/image.c Ramdisk subimage for unsupported architecture
3472 127 common/image.c Architecture check OK
3473 -127 common/image.c Can't get ramdisk subimage data/size
3474 128 common/image.c Got ramdisk subimage data/size
3475 129 common/image.c Can't get ramdisk load address
3476 -129 common/image.c Got ramdisk load address
3478 -130 common/cmd_doc.c Incorrect FIT image format
3479 131 common/cmd_doc.c FIT image format OK
3481 -140 common/cmd_ide.c Incorrect FIT image format
3482 141 common/cmd_ide.c FIT image format OK
3484 -150 common/cmd_nand.c Incorrect FIT image format
3485 151 common/cmd_nand.c FIT image format OK
3487 - legacy image format:
3488 CONFIG_IMAGE_FORMAT_LEGACY
3489 enables the legacy image format support in U-Boot.
3492 enabled if CONFIG_FIT_SIGNATURE is not defined.
3494 CONFIG_DISABLE_IMAGE_LEGACY
3495 disable the legacy image format
3497 This define is introduced, as the legacy image format is
3498 enabled per default for backward compatibility.
3500 - FIT image support:
3502 Enable support for the FIT uImage format.
3504 CONFIG_FIT_BEST_MATCH
3505 When no configuration is explicitly selected, default to the
3506 one whose fdt's compatibility field best matches that of
3507 U-Boot itself. A match is considered "best" if it matches the
3508 most specific compatibility entry of U-Boot's fdt's root node.
3509 The order of entries in the configuration's fdt is ignored.
3511 CONFIG_FIT_SIGNATURE
3512 This option enables signature verification of FIT uImages,
3513 using a hash signed and verified using RSA. If
3514 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3515 hashing is available using hardware, RSA library will use it.
3516 See doc/uImage.FIT/signature.txt for more details.
3518 WARNING: When relying on signed FIT images with required
3519 signature check the legacy image format is default
3520 disabled. If a board need legacy image format support
3521 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3523 CONFIG_FIT_DISABLE_SHA256
3524 Supporting SHA256 hashes has quite an impact on binary size.
3525 For constrained systems sha256 hash support can be disabled
3528 - Standalone program support:
3529 CONFIG_STANDALONE_LOAD_ADDR
3531 This option defines a board specific value for the
3532 address where standalone program gets loaded, thus
3533 overwriting the architecture dependent default
3536 - Frame Buffer Address:
3539 Define CONFIG_FB_ADDR if you want to use specific
3540 address for frame buffer. This is typically the case
3541 when using a graphics controller has separate video
3542 memory. U-Boot will then place the frame buffer at
3543 the given address instead of dynamically reserving it
3544 in system RAM by calling lcd_setmem(), which grabs
3545 the memory for the frame buffer depending on the
3546 configured panel size.
3548 Please see board_init_f function.
3550 - Automatic software updates via TFTP server
3552 CONFIG_UPDATE_TFTP_CNT_MAX
3553 CONFIG_UPDATE_TFTP_MSEC_MAX
3555 These options enable and control the auto-update feature;
3556 for a more detailed description refer to doc/README.update.
3558 - MTD Support (mtdparts command, UBI support)
3561 Adds the MTD device infrastructure from the Linux kernel.
3562 Needed for mtdparts command support.
3564 CONFIG_MTD_PARTITIONS
3566 Adds the MTD partitioning infrastructure from the Linux
3567 kernel. Needed for UBI support.
3572 Adds commands for interacting with MTD partitions formatted
3573 with the UBI flash translation layer
3575 Requires also defining CONFIG_RBTREE
3577 CONFIG_UBI_SILENCE_MSG
3579 Make the verbose messages from UBI stop printing. This leaves
3580 warnings and errors enabled.
3583 CONFIG_MTD_UBI_WL_THRESHOLD
3584 This parameter defines the maximum difference between the highest
3585 erase counter value and the lowest erase counter value of eraseblocks
3586 of UBI devices. When this threshold is exceeded, UBI starts performing
3587 wear leveling by means of moving data from eraseblock with low erase
3588 counter to eraseblocks with high erase counter.
3590 The default value should be OK for SLC NAND flashes, NOR flashes and
3591 other flashes which have eraseblock life-cycle 100000 or more.
3592 However, in case of MLC NAND flashes which typically have eraseblock
3593 life-cycle less than 10000, the threshold should be lessened (e.g.,
3594 to 128 or 256, although it does not have to be power of 2).
3598 CONFIG_MTD_UBI_BEB_LIMIT
3599 This option specifies the maximum bad physical eraseblocks UBI
3600 expects on the MTD device (per 1024 eraseblocks). If the
3601 underlying flash does not admit of bad eraseblocks (e.g. NOR
3602 flash), this value is ignored.
3604 NAND datasheets often specify the minimum and maximum NVM
3605 (Number of Valid Blocks) for the flashes' endurance lifetime.
3606 The maximum expected bad eraseblocks per 1024 eraseblocks
3607 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3608 which gives 20 for most NANDs (MaxNVB is basically the total
3609 count of eraseblocks on the chip).
3611 To put it differently, if this value is 20, UBI will try to
3612 reserve about 1.9% of physical eraseblocks for bad blocks
3613 handling. And that will be 1.9% of eraseblocks on the entire
3614 NAND chip, not just the MTD partition UBI attaches. This means
3615 that if you have, say, a NAND flash chip admits maximum 40 bad
3616 eraseblocks, and it is split on two MTD partitions of the same
3617 size, UBI will reserve 40 eraseblocks when attaching a
3622 CONFIG_MTD_UBI_FASTMAP
3623 Fastmap is a mechanism which allows attaching an UBI device
3624 in nearly constant time. Instead of scanning the whole MTD device it
3625 only has to locate a checkpoint (called fastmap) on the device.
3626 The on-flash fastmap contains all information needed to attach
3627 the device. Using fastmap makes only sense on large devices where
3628 attaching by scanning takes long. UBI will not automatically install
3629 a fastmap on old images, but you can set the UBI parameter
3630 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3631 that fastmap-enabled images are still usable with UBI implementations
3632 without fastmap support. On typical flash devices the whole fastmap
3633 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3635 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3636 Set this parameter to enable fastmap automatically on images
3643 Adds commands for interacting with UBI volumes formatted as
3644 UBIFS. UBIFS is read-only in u-boot.
3646 Requires UBI support as well as CONFIG_LZO
3648 CONFIG_UBIFS_SILENCE_MSG
3650 Make the verbose messages from UBIFS stop printing. This leaves
3651 warnings and errors enabled.
3655 Enable building of SPL globally.
3658 LDSCRIPT for linking the SPL binary.
3660 CONFIG_SPL_MAX_FOOTPRINT
3661 Maximum size in memory allocated to the SPL, BSS included.
3662 When defined, the linker checks that the actual memory
3663 used by SPL from _start to __bss_end does not exceed it.
3664 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3665 must not be both defined at the same time.
3668 Maximum size of the SPL image (text, data, rodata, and
3669 linker lists sections), BSS excluded.
3670 When defined, the linker checks that the actual size does
3673 CONFIG_SPL_TEXT_BASE
3674 TEXT_BASE for linking the SPL binary.
3676 CONFIG_SPL_RELOC_TEXT_BASE
3677 Address to relocate to. If unspecified, this is equal to
3678 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3680 CONFIG_SPL_BSS_START_ADDR
3681 Link address for the BSS within the SPL binary.
3683 CONFIG_SPL_BSS_MAX_SIZE
3684 Maximum size in memory allocated to the SPL BSS.
3685 When defined, the linker checks that the actual memory used
3686 by SPL from __bss_start to __bss_end does not exceed it.
3687 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3688 must not be both defined at the same time.
3691 Adress of the start of the stack SPL will use
3693 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3694 When defined, SPL will panic() if the image it has
3695 loaded does not have a signature.
3696 Defining this is useful when code which loads images
3697 in SPL cannot guarantee that absolutely all read errors
3699 An example is the LPC32XX MLC NAND driver, which will
3700 consider that a completely unreadable NAND block is bad,
3701 and thus should be skipped silently.
3703 CONFIG_SPL_RELOC_STACK
3704 Adress of the start of the stack SPL will use after
3705 relocation. If unspecified, this is equal to
3708 CONFIG_SYS_SPL_MALLOC_START
3709 Starting address of the malloc pool used in SPL.
3711 CONFIG_SYS_SPL_MALLOC_SIZE
3712 The size of the malloc pool used in SPL.
3714 CONFIG_SPL_FRAMEWORK
3715 Enable the SPL framework under common/. This framework
3716 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3717 NAND loading of the Linux Kernel.
3720 Enable booting directly to an OS from SPL.
3721 See also: doc/README.falcon
3723 CONFIG_SPL_DISPLAY_PRINT
3724 For ARM, enable an optional function to print more information
3725 about the running system.
3727 CONFIG_SPL_INIT_MINIMAL
3728 Arch init code should be built for a very small image
3730 CONFIG_SPL_LIBCOMMON_SUPPORT
3731 Support for common/libcommon.o in SPL binary
3733 CONFIG_SPL_LIBDISK_SUPPORT
3734 Support for disk/libdisk.o in SPL binary
3736 CONFIG_SPL_I2C_SUPPORT
3737 Support for drivers/i2c/libi2c.o in SPL binary
3739 CONFIG_SPL_GPIO_SUPPORT
3740 Support for drivers/gpio/libgpio.o in SPL binary
3742 CONFIG_SPL_MMC_SUPPORT
3743 Support for drivers/mmc/libmmc.o in SPL binary
3745 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3746 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3747 Address and partition on the MMC to load U-Boot from
3748 when the MMC is being used in raw mode.
3750 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3751 Partition on the MMC to load U-Boot from when the MMC is being
3754 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3755 Sector to load kernel uImage from when MMC is being
3756 used in raw mode (for Falcon mode)
3758 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3759 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3760 Sector and number of sectors to load kernel argument
3761 parameters from when MMC is being used in raw mode
3764 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3765 Partition on the MMC to load U-Boot from when the MMC is being
3768 CONFIG_SPL_FAT_SUPPORT
3769 Support for fs/fat/libfat.o in SPL binary
3771 CONFIG_SPL_EXT_SUPPORT
3772 Support for EXT filesystem in SPL binary
3774 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3775 Filename to read to load U-Boot when reading from filesystem
3777 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3778 Filename to read to load kernel uImage when reading
3779 from filesystem (for Falcon mode)
3781 CONFIG_SPL_FS_LOAD_ARGS_NAME
3782 Filename to read to load kernel argument parameters
3783 when reading from filesystem (for Falcon mode)
3785 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3786 Set this for NAND SPL on PPC mpc83xx targets, so that
3787 start.S waits for the rest of the SPL to load before
3788 continuing (the hardware starts execution after just
3789 loading the first page rather than the full 4K).
3791 CONFIG_SPL_SKIP_RELOCATE
3792 Avoid SPL relocation
3794 CONFIG_SPL_NAND_BASE
3795 Include nand_base.c in the SPL. Requires
3796 CONFIG_SPL_NAND_DRIVERS.
3798 CONFIG_SPL_NAND_DRIVERS
3799 SPL uses normal NAND drivers, not minimal drivers.
3802 Include standard software ECC in the SPL
3804 CONFIG_SPL_NAND_SIMPLE
3805 Support for NAND boot using simple NAND drivers that
3806 expose the cmd_ctrl() interface.
3808 CONFIG_SPL_MTD_SUPPORT
3809 Support for the MTD subsystem within SPL. Useful for
3810 environment on NAND support within SPL.
3812 CONFIG_SPL_NAND_RAW_ONLY
3813 Support to boot only raw u-boot.bin images. Use this only
3814 if you need to save space.
3816 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3817 Set for the SPL on PPC mpc8xxx targets, support for
3818 drivers/ddr/fsl/libddr.o in SPL binary.
3820 CONFIG_SPL_COMMON_INIT_DDR
3821 Set for common ddr init with serial presence detect in
3824 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3825 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3826 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3827 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3828 CONFIG_SYS_NAND_ECCBYTES
3829 Defines the size and behavior of the NAND that SPL uses
3832 CONFIG_SPL_NAND_BOOT
3833 Add support NAND boot
3835 CONFIG_SYS_NAND_U_BOOT_OFFS
3836 Location in NAND to read U-Boot from
3838 CONFIG_SYS_NAND_U_BOOT_DST
3839 Location in memory to load U-Boot to
3841 CONFIG_SYS_NAND_U_BOOT_SIZE
3842 Size of image to load
3844 CONFIG_SYS_NAND_U_BOOT_START
3845 Entry point in loaded image to jump to
3847 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3848 Define this if you need to first read the OOB and then the
3849 data. This is used, for example, on davinci platforms.
3851 CONFIG_SPL_OMAP3_ID_NAND
3852 Support for an OMAP3-specific set of functions to return the
3853 ID and MFR of the first attached NAND chip, if present.
3855 CONFIG_SPL_SERIAL_SUPPORT
3856 Support for drivers/serial/libserial.o in SPL binary
3858 CONFIG_SPL_SPI_FLASH_SUPPORT
3859 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3861 CONFIG_SPL_SPI_SUPPORT
3862 Support for drivers/spi/libspi.o in SPL binary
3864 CONFIG_SPL_RAM_DEVICE
3865 Support for running image already present in ram, in SPL binary
3867 CONFIG_SPL_LIBGENERIC_SUPPORT
3868 Support for lib/libgeneric.o in SPL binary
3870 CONFIG_SPL_ENV_SUPPORT
3871 Support for the environment operating in SPL binary
3873 CONFIG_SPL_NET_SUPPORT
3874 Support for the net/libnet.o in SPL binary.
3875 It conflicts with SPL env from storage medium specified by
3876 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3879 Image offset to which the SPL should be padded before appending
3880 the SPL payload. By default, this is defined as
3881 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3882 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3883 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3886 Final target image containing SPL and payload. Some SPLs
3887 use an arch-specific makefile fragment instead, for
3888 example if more than one image needs to be produced.
3890 CONFIG_FIT_SPL_PRINT
3891 Printing information about a FIT image adds quite a bit of
3892 code to SPL. So this is normally disabled in SPL. Use this
3893 option to re-enable it. This will affect the output of the
3894 bootm command when booting a FIT image.
3898 Enable building of TPL globally.
3901 Image offset to which the TPL should be padded before appending
3902 the TPL payload. By default, this is defined as
3903 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3904 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3905 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3910 [so far only for SMDK2400 boards]
3912 - Modem support enable:
3913 CONFIG_MODEM_SUPPORT
3915 - RTS/CTS Flow control enable:
3918 - Modem debug support:
3919 CONFIG_MODEM_SUPPORT_DEBUG
3921 Enables debugging stuff (char screen[1024], dbg())
3922 for modem support. Useful only with BDI2000.
3924 - Interrupt support (PPC):
3926 There are common interrupt_init() and timer_interrupt()
3927 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3928 for CPU specific initialization. interrupt_init_cpu()
3929 should set decrementer_count to appropriate value. If
3930 CPU resets decrementer automatically after interrupt
3931 (ppc4xx) it should set decrementer_count to zero.
3932 timer_interrupt() calls timer_interrupt_cpu() for CPU
3933 specific handling. If board has watchdog / status_led
3934 / other_activity_monitor it works automatically from
3935 general timer_interrupt().
3939 In the target system modem support is enabled when a
3940 specific key (key combination) is pressed during
3941 power-on. Otherwise U-Boot will boot normally
3942 (autoboot). The key_pressed() function is called from
3943 board_init(). Currently key_pressed() is a dummy
3944 function, returning 1 and thus enabling modem
3947 If there are no modem init strings in the
3948 environment, U-Boot proceed to autoboot; the
3949 previous output (banner, info printfs) will be
3952 See also: doc/README.Modem
3954 Board initialization settings:
3955 ------------------------------
3957 During Initialization u-boot calls a number of board specific functions
3958 to allow the preparation of board specific prerequisites, e.g. pin setup
3959 before drivers are initialized. To enable these callbacks the
3960 following configuration macros have to be defined. Currently this is
3961 architecture specific, so please check arch/your_architecture/lib/board.c
3962 typically in board_init_f() and board_init_r().
3964 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3965 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3966 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3967 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3969 Configuration Settings:
3970 -----------------------
3972 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3973 Optionally it can be defined to support 64-bit memory commands.
3975 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3976 undefine this when you're short of memory.
3978 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3979 width of the commands listed in the 'help' command output.
3981 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3982 prompt for user input.
3984 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3986 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3988 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3990 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3991 the application (usually a Linux kernel) when it is
3994 - CONFIG_SYS_BAUDRATE_TABLE:
3995 List of legal baudrate settings for this board.
3997 - CONFIG_SYS_CONSOLE_INFO_QUIET
3998 Suppress display of console information at boot.
4000 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4001 If the board specific function
4002 extern int overwrite_console (void);
4003 returns 1, the stdin, stderr and stdout are switched to the
4004 serial port, else the settings in the environment are used.
4006 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4007 Enable the call to overwrite_console().
4009 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4010 Enable overwrite of previous console environment settings.
4012 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4013 Begin and End addresses of the area used by the
4016 - CONFIG_SYS_ALT_MEMTEST:
4017 Enable an alternate, more extensive memory test.
4019 - CONFIG_SYS_MEMTEST_SCRATCH:
4020 Scratch address used by the alternate memory test
4021 You only need to set this if address zero isn't writeable
4023 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4024 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4025 this specified memory area will get subtracted from the top
4026 (end) of RAM and won't get "touched" at all by U-Boot. By
4027 fixing up gd->ram_size the Linux kernel should gets passed
4028 the now "corrected" memory size and won't touch it either.
4029 This should work for arch/ppc and arch/powerpc. Only Linux
4030 board ports in arch/powerpc with bootwrapper support that
4031 recalculate the memory size from the SDRAM controller setup
4032 will have to get fixed in Linux additionally.
4034 This option can be used as a workaround for the 440EPx/GRx
4035 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4038 WARNING: Please make sure that this value is a multiple of
4039 the Linux page size (normally 4k). If this is not the case,
4040 then the end address of the Linux memory will be located at a
4041 non page size aligned address and this could cause major
4044 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4045 Enable temporary baudrate change while serial download
4047 - CONFIG_SYS_SDRAM_BASE:
4048 Physical start address of SDRAM. _Must_ be 0 here.
4050 - CONFIG_SYS_MBIO_BASE:
4051 Physical start address of Motherboard I/O (if using a
4054 - CONFIG_SYS_FLASH_BASE:
4055 Physical start address of Flash memory.
4057 - CONFIG_SYS_MONITOR_BASE:
4058 Physical start address of boot monitor code (set by
4059 make config files to be same as the text base address
4060 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4061 CONFIG_SYS_FLASH_BASE when booting from flash.
4063 - CONFIG_SYS_MONITOR_LEN:
4064 Size of memory reserved for monitor code, used to
4065 determine _at_compile_time_ (!) if the environment is
4066 embedded within the U-Boot image, or in a separate
4069 - CONFIG_SYS_MALLOC_LEN:
4070 Size of DRAM reserved for malloc() use.
4072 - CONFIG_SYS_MALLOC_F_LEN
4073 Size of the malloc() pool for use before relocation. If
4074 this is defined, then a very simple malloc() implementation
4075 will become available before relocation. The address is just
4076 below the global data, and the stack is moved down to make
4079 This feature allocates regions with increasing addresses
4080 within the region. calloc() is supported, but realloc()
4081 is not available. free() is supported but does nothing.
4082 The memory will be freed (or in fact just forgotten) when
4083 U-Boot relocates itself.
4085 Pre-relocation malloc() is only supported on ARM and sandbox
4086 at present but is fairly easy to enable for other archs.
4088 - CONFIG_SYS_MALLOC_SIMPLE
4089 Provides a simple and small malloc() and calloc() for those
4090 boards which do not use the full malloc in SPL (which is
4091 enabled with CONFIG_SYS_SPL_MALLOC_START).
4093 - CONFIG_SYS_NONCACHED_MEMORY:
4094 Size of non-cached memory area. This area of memory will be
4095 typically located right below the malloc() area and mapped
4096 uncached in the MMU. This is useful for drivers that would
4097 otherwise require a lot of explicit cache maintenance. For
4098 some drivers it's also impossible to properly maintain the
4099 cache. For example if the regions that need to be flushed
4100 are not a multiple of the cache-line size, *and* padding
4101 cannot be allocated between the regions to align them (i.e.
4102 if the HW requires a contiguous array of regions, and the
4103 size of each region is not cache-aligned), then a flush of
4104 one region may result in overwriting data that hardware has
4105 written to another region in the same cache-line. This can
4106 happen for example in network drivers where descriptors for
4107 buffers are typically smaller than the CPU cache-line (e.g.
4108 16 bytes vs. 32 or 64 bytes).
4110 Non-cached memory is only supported on 32-bit ARM at present.
4112 - CONFIG_SYS_BOOTM_LEN:
4113 Normally compressed uImages are limited to an
4114 uncompressed size of 8 MBytes. If this is not enough,
4115 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4116 to adjust this setting to your needs.
4118 - CONFIG_SYS_BOOTMAPSZ:
4119 Maximum size of memory mapped by the startup code of
4120 the Linux kernel; all data that must be processed by
4121 the Linux kernel (bd_info, boot arguments, FDT blob if
4122 used) must be put below this limit, unless "bootm_low"
4123 environment variable is defined and non-zero. In such case
4124 all data for the Linux kernel must be between "bootm_low"
4125 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4126 variable "bootm_mapsize" will override the value of
4127 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4128 then the value in "bootm_size" will be used instead.
4130 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4131 Enable initrd_high functionality. If defined then the
4132 initrd_high feature is enabled and the bootm ramdisk subcommand
4135 - CONFIG_SYS_BOOT_GET_CMDLINE:
4136 Enables allocating and saving kernel cmdline in space between
4137 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4139 - CONFIG_SYS_BOOT_GET_KBD:
4140 Enables allocating and saving a kernel copy of the bd_info in
4141 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4143 - CONFIG_SYS_MAX_FLASH_BANKS:
4144 Max number of Flash memory banks
4146 - CONFIG_SYS_MAX_FLASH_SECT:
4147 Max number of sectors on a Flash chip
4149 - CONFIG_SYS_FLASH_ERASE_TOUT:
4150 Timeout for Flash erase operations (in ms)
4152 - CONFIG_SYS_FLASH_WRITE_TOUT:
4153 Timeout for Flash write operations (in ms)
4155 - CONFIG_SYS_FLASH_LOCK_TOUT
4156 Timeout for Flash set sector lock bit operation (in ms)
4158 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4159 Timeout for Flash clear lock bits operation (in ms)
4161 - CONFIG_SYS_FLASH_PROTECTION
4162 If defined, hardware flash sectors protection is used
4163 instead of U-Boot software protection.
4165 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4167 Enable TFTP transfers directly to flash memory;
4168 without this option such a download has to be
4169 performed in two steps: (1) download to RAM, and (2)
4170 copy from RAM to flash.
4172 The two-step approach is usually more reliable, since
4173 you can check if the download worked before you erase
4174 the flash, but in some situations (when system RAM is
4175 too limited to allow for a temporary copy of the
4176 downloaded image) this option may be very useful.
4178 - CONFIG_SYS_FLASH_CFI:
4179 Define if the flash driver uses extra elements in the
4180 common flash structure for storing flash geometry.
4182 - CONFIG_FLASH_CFI_DRIVER
4183 This option also enables the building of the cfi_flash driver
4184 in the drivers directory
4186 - CONFIG_FLASH_CFI_MTD
4187 This option enables the building of the cfi_mtd driver
4188 in the drivers directory. The driver exports CFI flash
4191 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4192 Use buffered writes to flash.
4194 - CONFIG_FLASH_SPANSION_S29WS_N
4195 s29ws-n MirrorBit flash has non-standard addresses for buffered
4198 - CONFIG_SYS_FLASH_QUIET_TEST
4199 If this option is defined, the common CFI flash doesn't
4200 print it's warning upon not recognized FLASH banks. This
4201 is useful, if some of the configured banks are only
4202 optionally available.
4204 - CONFIG_FLASH_SHOW_PROGRESS
4205 If defined (must be an integer), print out countdown
4206 digits and dots. Recommended value: 45 (9..1) for 80
4207 column displays, 15 (3..1) for 40 column displays.
4209 - CONFIG_FLASH_VERIFY
4210 If defined, the content of the flash (destination) is compared
4211 against the source after the write operation. An error message
4212 will be printed when the contents are not identical.
4213 Please note that this option is useless in nearly all cases,
4214 since such flash programming errors usually are detected earlier
4215 while unprotecting/erasing/programming. Please only enable
4216 this option if you really know what you are doing.
4218 - CONFIG_SYS_RX_ETH_BUFFER:
4219 Defines the number of Ethernet receive buffers. On some
4220 Ethernet controllers it is recommended to set this value
4221 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4222 buffers can be full shortly after enabling the interface
4223 on high Ethernet traffic.
4224 Defaults to 4 if not defined.
4226 - CONFIG_ENV_MAX_ENTRIES
4228 Maximum number of entries in the hash table that is used
4229 internally to store the environment settings. The default
4230 setting is supposed to be generous and should work in most
4231 cases. This setting can be used to tune behaviour; see
4232 lib/hashtable.c for details.
4234 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4235 - CONFIG_ENV_FLAGS_LIST_STATIC
4236 Enable validation of the values given to environment variables when
4237 calling env set. Variables can be restricted to only decimal,
4238 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4239 the variables can also be restricted to IP address or MAC address.
4241 The format of the list is:
4242 type_attribute = [s|d|x|b|i|m]
4243 access_attribute = [a|r|o|c]
4244 attributes = type_attribute[access_attribute]
4245 entry = variable_name[:attributes]
4248 The type attributes are:
4249 s - String (default)
4252 b - Boolean ([1yYtT|0nNfF])
4256 The access attributes are:
4262 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4263 Define this to a list (string) to define the ".flags"
4264 environment variable in the default or embedded environment.
4266 - CONFIG_ENV_FLAGS_LIST_STATIC
4267 Define this to a list (string) to define validation that
4268 should be done if an entry is not found in the ".flags"
4269 environment variable. To override a setting in the static
4270 list, simply add an entry for the same variable name to the
4273 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4274 regular expression. This allows multiple variables to define the same
4275 flags without explicitly listing them for each variable.
4277 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4278 If defined, don't allow the -f switch to env set override variable
4281 - CONFIG_SYS_GENERIC_BOARD
4282 This selects the architecture-generic board system instead of the
4283 architecture-specific board files. It is intended to move boards
4284 to this new framework over time. Defining this will disable the
4285 arch/foo/lib/board.c file and use common/board_f.c and
4286 common/board_r.c instead. To use this option your architecture
4287 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4288 If you find problems enabling this option on your board please report
4289 the problem and send patches!
4291 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4292 This is set by OMAP boards for the max time that reset should
4293 be asserted. See doc/README.omap-reset-time for details on how
4294 the value can be calculated on a given board.
4297 If stdint.h is available with your toolchain you can define this
4298 option to enable it. You can provide option 'USE_STDINT=1' when
4299 building U-Boot to enable this.
4301 The following definitions that deal with the placement and management
4302 of environment data (variable area); in general, we support the
4303 following configurations:
4305 - CONFIG_BUILD_ENVCRC:
4307 Builds up envcrc with the target environment so that external utils
4308 may easily extract it and embed it in final U-Boot images.
4310 - CONFIG_ENV_IS_IN_FLASH:
4312 Define this if the environment is in flash memory.
4314 a) The environment occupies one whole flash sector, which is
4315 "embedded" in the text segment with the U-Boot code. This
4316 happens usually with "bottom boot sector" or "top boot
4317 sector" type flash chips, which have several smaller
4318 sectors at the start or the end. For instance, such a
4319 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4320 such a case you would place the environment in one of the
4321 4 kB sectors - with U-Boot code before and after it. With
4322 "top boot sector" type flash chips, you would put the
4323 environment in one of the last sectors, leaving a gap
4324 between U-Boot and the environment.
4326 - CONFIG_ENV_OFFSET:
4328 Offset of environment data (variable area) to the
4329 beginning of flash memory; for instance, with bottom boot
4330 type flash chips the second sector can be used: the offset
4331 for this sector is given here.
4333 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4337 This is just another way to specify the start address of
4338 the flash sector containing the environment (instead of
4341 - CONFIG_ENV_SECT_SIZE:
4343 Size of the sector containing the environment.
4346 b) Sometimes flash chips have few, equal sized, BIG sectors.
4347 In such a case you don't want to spend a whole sector for
4352 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4353 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4354 of this flash sector for the environment. This saves
4355 memory for the RAM copy of the environment.
4357 It may also save flash memory if you decide to use this
4358 when your environment is "embedded" within U-Boot code,
4359 since then the remainder of the flash sector could be used
4360 for U-Boot code. It should be pointed out that this is
4361 STRONGLY DISCOURAGED from a robustness point of view:
4362 updating the environment in flash makes it always
4363 necessary to erase the WHOLE sector. If something goes
4364 wrong before the contents has been restored from a copy in
4365 RAM, your target system will be dead.
4367 - CONFIG_ENV_ADDR_REDUND
4368 CONFIG_ENV_SIZE_REDUND
4370 These settings describe a second storage area used to hold
4371 a redundant copy of the environment data, so that there is
4372 a valid backup copy in case there is a power failure during
4373 a "saveenv" operation.
4375 BE CAREFUL! Any changes to the flash layout, and some changes to the
4376 source code will make it necessary to adapt <board>/u-boot.lds*
4380 - CONFIG_ENV_IS_IN_NVRAM:
4382 Define this if you have some non-volatile memory device
4383 (NVRAM, battery buffered SRAM) which you want to use for the
4389 These two #defines are used to determine the memory area you
4390 want to use for environment. It is assumed that this memory
4391 can just be read and written to, without any special
4394 BE CAREFUL! The first access to the environment happens quite early
4395 in U-Boot initialization (when we try to get the setting of for the
4396 console baudrate). You *MUST* have mapped your NVRAM area then, or
4399 Please note that even with NVRAM we still use a copy of the
4400 environment in RAM: we could work on NVRAM directly, but we want to
4401 keep settings there always unmodified except somebody uses "saveenv"
4402 to save the current settings.
4405 - CONFIG_ENV_IS_IN_EEPROM:
4407 Use this if you have an EEPROM or similar serial access
4408 device and a driver for it.
4410 - CONFIG_ENV_OFFSET:
4413 These two #defines specify the offset and size of the
4414 environment area within the total memory of your EEPROM.
4416 - CONFIG_SYS_I2C_EEPROM_ADDR:
4417 If defined, specified the chip address of the EEPROM device.
4418 The default address is zero.
4420 - CONFIG_SYS_I2C_EEPROM_BUS:
4421 If defined, specified the i2c bus of the EEPROM device.
4423 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4424 If defined, the number of bits used to address bytes in a
4425 single page in the EEPROM device. A 64 byte page, for example
4426 would require six bits.
4428 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4429 If defined, the number of milliseconds to delay between
4430 page writes. The default is zero milliseconds.
4432 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4433 The length in bytes of the EEPROM memory array address. Note
4434 that this is NOT the chip address length!
4436 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4437 EEPROM chips that implement "address overflow" are ones
4438 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4439 address and the extra bits end up in the "chip address" bit
4440 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4443 Note that we consider the length of the address field to
4444 still be one byte because the extra address bits are hidden
4445 in the chip address.
4447 - CONFIG_SYS_EEPROM_SIZE:
4448 The size in bytes of the EEPROM device.
4450 - CONFIG_ENV_EEPROM_IS_ON_I2C
4451 define this, if you have I2C and SPI activated, and your
4452 EEPROM, which holds the environment, is on the I2C bus.
4454 - CONFIG_I2C_ENV_EEPROM_BUS
4455 if you have an Environment on an EEPROM reached over
4456 I2C muxes, you can define here, how to reach this
4457 EEPROM. For example:
4459 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4461 EEPROM which holds the environment, is reached over
4462 a pca9547 i2c mux with address 0x70, channel 3.
4464 - CONFIG_ENV_IS_IN_DATAFLASH:
4466 Define this if you have a DataFlash memory device which you
4467 want to use for the environment.
4469 - CONFIG_ENV_OFFSET:
4473 These three #defines specify the offset and size of the
4474 environment area within the total memory of your DataFlash placed
4475 at the specified address.
4477 - CONFIG_ENV_IS_IN_SPI_FLASH:
4479 Define this if you have a SPI Flash memory device which you
4480 want to use for the environment.
4482 - CONFIG_ENV_OFFSET:
4485 These two #defines specify the offset and size of the
4486 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4487 aligned to an erase sector boundary.
4489 - CONFIG_ENV_SECT_SIZE:
4491 Define the SPI flash's sector size.
4493 - CONFIG_ENV_OFFSET_REDUND (optional):
4495 This setting describes a second storage area of CONFIG_ENV_SIZE
4496 size used to hold a redundant copy of the environment data, so
4497 that there is a valid backup copy in case there is a power failure
4498 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4499 aligned to an erase sector boundary.
4501 - CONFIG_ENV_SPI_BUS (optional):
4502 - CONFIG_ENV_SPI_CS (optional):
4504 Define the SPI bus and chip select. If not defined they will be 0.
4506 - CONFIG_ENV_SPI_MAX_HZ (optional):
4508 Define the SPI max work clock. If not defined then use 1MHz.
4510 - CONFIG_ENV_SPI_MODE (optional):
4512 Define the SPI work mode. If not defined then use SPI_MODE_3.
4514 - CONFIG_ENV_IS_IN_REMOTE:
4516 Define this if you have a remote memory space which you
4517 want to use for the local device's environment.
4522 These two #defines specify the address and size of the
4523 environment area within the remote memory space. The
4524 local device can get the environment from remote memory
4525 space by SRIO or PCIE links.
4527 BE CAREFUL! For some special cases, the local device can not use
4528 "saveenv" command. For example, the local device will get the
4529 environment stored in a remote NOR flash by SRIO or PCIE link,
4530 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4532 - CONFIG_ENV_IS_IN_NAND:
4534 Define this if you have a NAND device which you want to use
4535 for the environment.
4537 - CONFIG_ENV_OFFSET:
4540 These two #defines specify the offset and size of the environment
4541 area within the first NAND device. CONFIG_ENV_OFFSET must be
4542 aligned to an erase block boundary.
4544 - CONFIG_ENV_OFFSET_REDUND (optional):
4546 This setting describes a second storage area of CONFIG_ENV_SIZE
4547 size used to hold a redundant copy of the environment data, so
4548 that there is a valid backup copy in case there is a power failure
4549 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4550 aligned to an erase block boundary.
4552 - CONFIG_ENV_RANGE (optional):
4554 Specifies the length of the region in which the environment
4555 can be written. This should be a multiple of the NAND device's
4556 block size. Specifying a range with more erase blocks than
4557 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4558 the range to be avoided.
4560 - CONFIG_ENV_OFFSET_OOB (optional):
4562 Enables support for dynamically retrieving the offset of the
4563 environment from block zero's out-of-band data. The
4564 "nand env.oob" command can be used to record this offset.
4565 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4566 using CONFIG_ENV_OFFSET_OOB.
4568 - CONFIG_NAND_ENV_DST
4570 Defines address in RAM to which the nand_spl code should copy the
4571 environment. If redundant environment is used, it will be copied to
4572 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4574 - CONFIG_ENV_IS_IN_UBI:
4576 Define this if you have an UBI volume that you want to use for the
4577 environment. This has the benefit of wear-leveling the environment
4578 accesses, which is important on NAND.
4580 - CONFIG_ENV_UBI_PART:
4582 Define this to a string that is the mtd partition containing the UBI.
4584 - CONFIG_ENV_UBI_VOLUME:
4586 Define this to the name of the volume that you want to store the
4589 - CONFIG_ENV_UBI_VOLUME_REDUND:
4591 Define this to the name of another volume to store a second copy of
4592 the environment in. This will enable redundant environments in UBI.
4593 It is assumed that both volumes are in the same MTD partition.
4595 - CONFIG_UBI_SILENCE_MSG
4596 - CONFIG_UBIFS_SILENCE_MSG
4598 You will probably want to define these to avoid a really noisy system
4599 when storing the env in UBI.
4601 - CONFIG_ENV_IS_IN_FAT:
4602 Define this if you want to use the FAT file system for the environment.
4604 - FAT_ENV_INTERFACE:
4606 Define this to a string that is the name of the block device.
4608 - FAT_ENV_DEV_AND_PART:
4610 Define this to a string to specify the partition of the device. It can
4613 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4614 - "D:P": device D partition P. Error occurs if device D has no
4617 - "D" or "D:": device D partition 1 if device D has partition
4618 table, or the whole device D if has no partition
4620 - "D:auto": first partition in device D with bootable flag set.
4621 If none, first valid partition in device D. If no
4622 partition table then means device D.
4626 It's a string of the FAT file name. This file use to store the
4630 This should be defined. Otherwise it cannot save the environment file.
4632 - CONFIG_ENV_IS_IN_MMC:
4634 Define this if you have an MMC device which you want to use for the
4637 - CONFIG_SYS_MMC_ENV_DEV:
4639 Specifies which MMC device the environment is stored in.
4641 - CONFIG_SYS_MMC_ENV_PART (optional):
4643 Specifies which MMC partition the environment is stored in. If not
4644 set, defaults to partition 0, the user area. Common values might be
4645 1 (first MMC boot partition), 2 (second MMC boot partition).
4647 - CONFIG_ENV_OFFSET:
4650 These two #defines specify the offset and size of the environment
4651 area within the specified MMC device.
4653 If offset is positive (the usual case), it is treated as relative to
4654 the start of the MMC partition. If offset is negative, it is treated
4655 as relative to the end of the MMC partition. This can be useful if
4656 your board may be fitted with different MMC devices, which have
4657 different sizes for the MMC partitions, and you always want the
4658 environment placed at the very end of the partition, to leave the
4659 maximum possible space before it, to store other data.
4661 These two values are in units of bytes, but must be aligned to an
4662 MMC sector boundary.
4664 - CONFIG_ENV_OFFSET_REDUND (optional):
4666 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4667 hold a redundant copy of the environment data. This provides a
4668 valid backup copy in case the other copy is corrupted, e.g. due
4669 to a power failure during a "saveenv" operation.
4671 This value may also be positive or negative; this is handled in the
4672 same way as CONFIG_ENV_OFFSET.
4674 This value is also in units of bytes, but must also be aligned to
4675 an MMC sector boundary.
4677 - CONFIG_ENV_SIZE_REDUND (optional):
4679 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4680 set. If this value is set, it must be set to the same value as
4683 - CONFIG_SYS_SPI_INIT_OFFSET
4685 Defines offset to the initial SPI buffer area in DPRAM. The
4686 area is used at an early stage (ROM part) if the environment
4687 is configured to reside in the SPI EEPROM: We need a 520 byte
4688 scratch DPRAM area. It is used between the two initialization
4689 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4690 to be a good choice since it makes it far enough from the
4691 start of the data area as well as from the stack pointer.
4693 Please note that the environment is read-only until the monitor
4694 has been relocated to RAM and a RAM copy of the environment has been
4695 created; also, when using EEPROM you will have to use getenv_f()
4696 until then to read environment variables.
4698 The environment is protected by a CRC32 checksum. Before the monitor
4699 is relocated into RAM, as a result of a bad CRC you will be working
4700 with the compiled-in default environment - *silently*!!! [This is
4701 necessary, because the first environment variable we need is the
4702 "baudrate" setting for the console - if we have a bad CRC, we don't
4703 have any device yet where we could complain.]
4705 Note: once the monitor has been relocated, then it will complain if
4706 the default environment is used; a new CRC is computed as soon as you
4707 use the "saveenv" command to store a valid environment.
4709 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4710 Echo the inverted Ethernet link state to the fault LED.
4712 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4713 also needs to be defined.
4715 - CONFIG_SYS_FAULT_MII_ADDR:
4716 MII address of the PHY to check for the Ethernet link state.
4718 - CONFIG_NS16550_MIN_FUNCTIONS:
4719 Define this if you desire to only have use of the NS16550_init
4720 and NS16550_putc functions for the serial driver located at
4721 drivers/serial/ns16550.c. This option is useful for saving
4722 space for already greatly restricted images, including but not
4723 limited to NAND_SPL configurations.
4725 - CONFIG_DISPLAY_BOARDINFO
4726 Display information about the board that U-Boot is running on
4727 when U-Boot starts up. The board function checkboard() is called
4730 - CONFIG_DISPLAY_BOARDINFO_LATE
4731 Similar to the previous option, but display this information
4732 later, once stdio is running and output goes to the LCD, if
4735 - CONFIG_BOARD_SIZE_LIMIT:
4736 Maximum size of the U-Boot image. When defined, the
4737 build system checks that the actual size does not
4740 Low Level (hardware related) configuration options:
4741 ---------------------------------------------------
4743 - CONFIG_SYS_CACHELINE_SIZE:
4744 Cache Line Size of the CPU.
4746 - CONFIG_SYS_DEFAULT_IMMR:
4747 Default address of the IMMR after system reset.
4749 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4750 and RPXsuper) to be able to adjust the position of
4751 the IMMR register after a reset.
4753 - CONFIG_SYS_CCSRBAR_DEFAULT:
4754 Default (power-on reset) physical address of CCSR on Freescale
4757 - CONFIG_SYS_CCSRBAR:
4758 Virtual address of CCSR. On a 32-bit build, this is typically
4759 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4761 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4762 for cross-platform code that uses that macro instead.
4764 - CONFIG_SYS_CCSRBAR_PHYS:
4765 Physical address of CCSR. CCSR can be relocated to a new
4766 physical address, if desired. In this case, this macro should
4767 be set to that address. Otherwise, it should be set to the
4768 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4769 is typically relocated on 36-bit builds. It is recommended
4770 that this macro be defined via the _HIGH and _LOW macros:
4772 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4773 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4775 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4776 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4777 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4778 used in assembly code, so it must not contain typecasts or
4779 integer size suffixes (e.g. "ULL").
4781 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4782 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4783 used in assembly code, so it must not contain typecasts or
4784 integer size suffixes (e.g. "ULL").
4786 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4787 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4788 forced to a value that ensures that CCSR is not relocated.
4790 - Floppy Disk Support:
4791 CONFIG_SYS_FDC_DRIVE_NUMBER
4793 the default drive number (default value 0)
4795 CONFIG_SYS_ISA_IO_STRIDE
4797 defines the spacing between FDC chipset registers
4800 CONFIG_SYS_ISA_IO_OFFSET
4802 defines the offset of register from address. It
4803 depends on which part of the data bus is connected to
4804 the FDC chipset. (default value 0)
4806 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4807 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4810 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4811 fdc_hw_init() is called at the beginning of the FDC
4812 setup. fdc_hw_init() must be provided by the board
4813 source code. It is used to make hardware-dependent
4817 Most IDE controllers were designed to be connected with PCI
4818 interface. Only few of them were designed for AHB interface.
4819 When software is doing ATA command and data transfer to
4820 IDE devices through IDE-AHB controller, some additional
4821 registers accessing to these kind of IDE-AHB controller
4824 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4825 DO NOT CHANGE unless you know exactly what you're
4826 doing! (11-4) [MPC8xx/82xx systems only]
4828 - CONFIG_SYS_INIT_RAM_ADDR:
4830 Start address of memory area that can be used for
4831 initial data and stack; please note that this must be
4832 writable memory that is working WITHOUT special
4833 initialization, i. e. you CANNOT use normal RAM which
4834 will become available only after programming the
4835 memory controller and running certain initialization
4838 U-Boot uses the following memory types:
4839 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4840 - MPC824X: data cache
4841 - PPC4xx: data cache
4843 - CONFIG_SYS_GBL_DATA_OFFSET:
4845 Offset of the initial data structure in the memory
4846 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4847 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4848 data is located at the end of the available space
4849 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4850 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4851 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4852 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4855 On the MPC824X (or other systems that use the data
4856 cache for initial memory) the address chosen for
4857 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4858 point to an otherwise UNUSED address space between
4859 the top of RAM and the start of the PCI space.
4861 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4863 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4865 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4867 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4869 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4871 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4873 - CONFIG_SYS_OR_TIMING_SDRAM:
4876 - CONFIG_SYS_MAMR_PTA:
4877 periodic timer for refresh
4879 - CONFIG_SYS_DER: Debug Event Register (37-47)
4881 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4882 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4883 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4884 CONFIG_SYS_BR1_PRELIM:
4885 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4887 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4888 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4889 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4890 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4892 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4893 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4894 Machine Mode Register and Memory Periodic Timer
4895 Prescaler definitions (SDRAM timing)
4897 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4898 enable I2C microcode relocation patch (MPC8xx);
4899 define relocation offset in DPRAM [DSP2]
4901 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4902 enable SMC microcode relocation patch (MPC8xx);
4903 define relocation offset in DPRAM [SMC1]
4905 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4906 enable SPI microcode relocation patch (MPC8xx);
4907 define relocation offset in DPRAM [SCC4]
4909 - CONFIG_SYS_USE_OSCCLK:
4910 Use OSCM clock mode on MBX8xx board. Be careful,
4911 wrong setting might damage your board. Read
4912 doc/README.MBX before setting this variable!
4914 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4915 Offset of the bootmode word in DPRAM used by post
4916 (Power On Self Tests). This definition overrides
4917 #define'd default value in commproc.h resp.
4920 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4921 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4922 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4923 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4924 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4925 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4926 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4927 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4928 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4930 - CONFIG_PCI_DISABLE_PCIE:
4931 Disable PCI-Express on systems where it is supported but not
4934 - CONFIG_PCI_ENUM_ONLY
4935 Only scan through and get the devices on the buses.
4936 Don't do any setup work, presumably because someone or
4937 something has already done it, and we don't need to do it
4938 a second time. Useful for platforms that are pre-booted
4939 by coreboot or similar.
4941 - CONFIG_PCI_INDIRECT_BRIDGE:
4942 Enable support for indirect PCI bridges.
4945 Chip has SRIO or not
4948 Board has SRIO 1 port available
4951 Board has SRIO 2 port available
4953 - CONFIG_SRIO_PCIE_BOOT_MASTER
4954 Board can support master function for Boot from SRIO and PCIE
4956 - CONFIG_SYS_SRIOn_MEM_VIRT:
4957 Virtual Address of SRIO port 'n' memory region
4959 - CONFIG_SYS_SRIOn_MEM_PHYS:
4960 Physical Address of SRIO port 'n' memory region
4962 - CONFIG_SYS_SRIOn_MEM_SIZE:
4963 Size of SRIO port 'n' memory region
4965 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4966 Defined to tell the NAND controller that the NAND chip is using
4968 Not all NAND drivers use this symbol.
4969 Example of drivers that use it:
4970 - drivers/mtd/nand/ndfc.c
4971 - drivers/mtd/nand/mxc_nand.c
4973 - CONFIG_SYS_NDFC_EBC0_CFG
4974 Sets the EBC0_CFG register for the NDFC. If not defined
4975 a default value will be used.
4978 Get DDR timing information from an I2C EEPROM. Common
4979 with pluggable memory modules such as SODIMMs
4982 I2C address of the SPD EEPROM
4984 - CONFIG_SYS_SPD_BUS_NUM
4985 If SPD EEPROM is on an I2C bus other than the first
4986 one, specify here. Note that the value must resolve
4987 to something your driver can deal with.
4989 - CONFIG_SYS_DDR_RAW_TIMING
4990 Get DDR timing information from other than SPD. Common with
4991 soldered DDR chips onboard without SPD. DDR raw timing
4992 parameters are extracted from datasheet and hard-coded into
4993 header files or board specific files.
4995 - CONFIG_FSL_DDR_INTERACTIVE
4996 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4998 - CONFIG_FSL_DDR_SYNC_REFRESH
4999 Enable sync of refresh for multiple controllers.
5001 - CONFIG_FSL_DDR_BIST
5002 Enable built-in memory test for Freescale DDR controllers.
5004 - CONFIG_SYS_83XX_DDR_USES_CS0
5005 Only for 83xx systems. If specified, then DDR should
5006 be configured using CS0 and CS1 instead of CS2 and CS3.
5008 - CONFIG_ETHER_ON_FEC[12]
5009 Define to enable FEC[12] on a 8xx series processor.
5011 - CONFIG_FEC[12]_PHY
5012 Define to the hardcoded PHY address which corresponds
5013 to the given FEC; i. e.
5014 #define CONFIG_FEC1_PHY 4
5015 means that the PHY with address 4 is connected to FEC1
5017 When set to -1, means to probe for first available.
5019 - CONFIG_FEC[12]_PHY_NORXERR
5020 The PHY does not have a RXERR line (RMII only).
5021 (so program the FEC to ignore it).
5024 Enable RMII mode for all FECs.
5025 Note that this is a global option, we can't
5026 have one FEC in standard MII mode and another in RMII mode.
5028 - CONFIG_CRC32_VERIFY
5029 Add a verify option to the crc32 command.
5032 => crc32 -v <address> <count> <crc32>
5034 Where address/count indicate a memory area
5035 and crc32 is the correct crc32 which the
5039 Add the "loopw" memory command. This only takes effect if
5040 the memory commands are activated globally (CONFIG_CMD_MEM).
5043 Add the "mdc" and "mwc" memory commands. These are cyclic
5048 This command will print 4 bytes (10,11,12,13) each 500 ms.
5050 => mwc.l 100 12345678 10
5051 This command will write 12345678 to address 100 all 10 ms.
5053 This only takes effect if the memory commands are activated
5054 globally (CONFIG_CMD_MEM).
5056 - CONFIG_SKIP_LOWLEVEL_INIT
5057 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5058 low level initializations (like setting up the memory
5059 controller) are omitted and/or U-Boot does not
5060 relocate itself into RAM.
5062 Normally this variable MUST NOT be defined. The only
5063 exception is when U-Boot is loaded (to RAM) by some
5064 other boot loader or by a debugger which performs
5065 these initializations itself.
5068 Modifies the behaviour of start.S when compiling a loader
5069 that is executed before the actual U-Boot. E.g. when
5070 compiling a NAND SPL.
5073 Modifies the behaviour of start.S when compiling a loader
5074 that is executed after the SPL and before the actual U-Boot.
5075 It is loaded by the SPL.
5077 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5078 Only for 85xx systems. If this variable is specified, the section
5079 .resetvec is not kept and the section .bootpg is placed in the
5080 previous 4k of the .text section.
5082 - CONFIG_ARCH_MAP_SYSMEM
5083 Generally U-Boot (and in particular the md command) uses
5084 effective address. It is therefore not necessary to regard
5085 U-Boot address as virtual addresses that need to be translated
5086 to physical addresses. However, sandbox requires this, since
5087 it maintains its own little RAM buffer which contains all
5088 addressable memory. This option causes some memory accesses
5089 to be mapped through map_sysmem() / unmap_sysmem().
5091 - CONFIG_USE_ARCH_MEMCPY
5092 CONFIG_USE_ARCH_MEMSET
5093 If these options are used a optimized version of memcpy/memset will
5094 be used if available. These functions may be faster under some
5095 conditions but may increase the binary size.
5097 - CONFIG_X86_RESET_VECTOR
5098 If defined, the x86 reset vector code is included. This is not
5099 needed when U-Boot is running from Coreboot.
5102 Defines the MPU clock speed (in MHz).
5104 NOTE : currently only supported on AM335x platforms.
5106 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5107 Enables the RTC32K OSC on AM33xx based plattforms
5109 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5110 Option to disable subpage write in NAND driver
5111 driver that uses this:
5112 drivers/mtd/nand/davinci_nand.c
5114 Freescale QE/FMAN Firmware Support:
5115 -----------------------------------
5117 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5118 loading of "firmware", which is encoded in the QE firmware binary format.
5119 This firmware often needs to be loaded during U-Boot booting, so macros
5120 are used to identify the storage device (NOR flash, SPI, etc) and the address
5123 - CONFIG_SYS_FMAN_FW_ADDR
5124 The address in the storage device where the FMAN microcode is located. The
5125 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5128 - CONFIG_SYS_QE_FW_ADDR
5129 The address in the storage device where the QE microcode is located. The
5130 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5133 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5134 The maximum possible size of the firmware. The firmware binary format
5135 has a field that specifies the actual size of the firmware, but it
5136 might not be possible to read any part of the firmware unless some
5137 local storage is allocated to hold the entire firmware first.
5139 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5140 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5141 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5142 virtual address in NOR flash.
5144 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5145 Specifies that QE/FMAN firmware is located in NAND flash.
5146 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5148 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5149 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5150 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5152 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5153 Specifies that QE/FMAN firmware is located on the primary SPI
5154 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5156 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5157 Specifies that QE/FMAN firmware is located in the remote (master)
5158 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5159 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5160 window->master inbound window->master LAW->the ucode address in
5161 master's memory space.
5163 Freescale Layerscape Management Complex Firmware Support:
5164 ---------------------------------------------------------
5165 The Freescale Layerscape Management Complex (MC) supports the loading of
5167 This firmware often needs to be loaded during U-Boot booting, so macros
5168 are used to identify the storage device (NOR flash, SPI, etc) and the address
5171 - CONFIG_FSL_MC_ENET
5172 Enable the MC driver for Layerscape SoCs.
5174 - CONFIG_SYS_LS_MC_FW_ADDR
5175 The address in the storage device where the firmware is located. The
5176 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5179 - CONFIG_SYS_LS_MC_FW_LENGTH
5180 The maximum possible size of the firmware. The firmware binary format
5181 has a field that specifies the actual size of the firmware, but it
5182 might not be possible to read any part of the firmware unless some
5183 local storage is allocated to hold the entire firmware first.
5185 - CONFIG_SYS_LS_MC_FW_IN_NOR
5186 Specifies that MC firmware is located in NOR flash, mapped as
5187 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5188 virtual address in NOR flash.
5190 Freescale Layerscape Debug Server Support:
5191 -------------------------------------------
5192 The Freescale Layerscape Debug Server Support supports the loading of
5193 "Debug Server firmware" and triggering SP boot-rom.
5194 This firmware often needs to be loaded during U-Boot booting.
5196 - CONFIG_FSL_DEBUG_SERVER
5197 Enable the Debug Server for Layerscape SoCs.
5199 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5200 Define minimum DDR size required for debug server image
5202 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5203 Define minimum DDR size to be hided from top of the DDR memory
5208 In order to achieve reproducible builds, timestamps used in the U-Boot build
5209 process have to be set to a fixed value.
5211 This is done using the SOURCE_DATE_EPOCH environment variable.
5212 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5213 option for U-Boot or an environment variable in U-Boot.
5215 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5217 Building the Software:
5218 ======================
5220 Building U-Boot has been tested in several native build environments
5221 and in many different cross environments. Of course we cannot support
5222 all possibly existing versions of cross development tools in all
5223 (potentially obsolete) versions. In case of tool chain problems we
5224 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5225 which is extensively used to build and test U-Boot.
5227 If you are not using a native environment, it is assumed that you
5228 have GNU cross compiling tools available in your path. In this case,
5229 you must set the environment variable CROSS_COMPILE in your shell.
5230 Note that no changes to the Makefile or any other source files are
5231 necessary. For example using the ELDK on a 4xx CPU, please enter:
5233 $ CROSS_COMPILE=ppc_4xx-
5234 $ export CROSS_COMPILE
5236 Note: If you wish to generate Windows versions of the utilities in
5237 the tools directory you can use the MinGW toolchain
5238 (http://www.mingw.org). Set your HOST tools to the MinGW
5239 toolchain and execute 'make tools'. For example:
5241 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5243 Binaries such as tools/mkimage.exe will be created which can
5244 be executed on computers running Windows.
5246 U-Boot is intended to be simple to build. After installing the
5247 sources you must configure U-Boot for one specific board type. This
5252 where "NAME_defconfig" is the name of one of the existing configu-
5253 rations; see boards.cfg for supported names.
5255 Note: for some board special configuration names may exist; check if
5256 additional information is available from the board vendor; for
5257 instance, the TQM823L systems are available without (standard)
5258 or with LCD support. You can select such additional "features"
5259 when choosing the configuration, i. e.
5261 make TQM823L_defconfig
5262 - will configure for a plain TQM823L, i. e. no LCD support
5264 make TQM823L_LCD_defconfig
5265 - will configure for a TQM823L with U-Boot console on LCD
5270 Finally, type "make all", and you should get some working U-Boot
5271 images ready for download to / installation on your system:
5273 - "u-boot.bin" is a raw binary image
5274 - "u-boot" is an image in ELF binary format
5275 - "u-boot.srec" is in Motorola S-Record format
5277 By default the build is performed locally and the objects are saved
5278 in the source directory. One of the two methods can be used to change
5279 this behavior and build U-Boot to some external directory:
5281 1. Add O= to the make command line invocations:
5283 make O=/tmp/build distclean
5284 make O=/tmp/build NAME_defconfig
5285 make O=/tmp/build all
5287 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5289 export KBUILD_OUTPUT=/tmp/build
5294 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5298 Please be aware that the Makefiles assume you are using GNU make, so
5299 for instance on NetBSD you might need to use "gmake" instead of
5303 If the system board that you have is not listed, then you will need
5304 to port U-Boot to your hardware platform. To do this, follow these
5307 1. Add a new configuration option for your board to the toplevel
5308 "boards.cfg" file, using the existing entries as examples.
5309 Follow the instructions there to keep the boards in order.
5310 2. Create a new directory to hold your board specific code. Add any
5311 files you need. In your board directory, you will need at least
5312 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5313 3. Create a new configuration file "include/configs/<board>.h" for
5315 3. If you're porting U-Boot to a new CPU, then also create a new
5316 directory to hold your CPU specific code. Add any files you need.
5317 4. Run "make <board>_defconfig" with your new name.
5318 5. Type "make", and you should get a working "u-boot.srec" file
5319 to be installed on your target system.
5320 6. Debug and solve any problems that might arise.
5321 [Of course, this last step is much harder than it sounds.]
5324 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5325 ==============================================================
5327 If you have modified U-Boot sources (for instance added a new board
5328 or support for new devices, a new CPU, etc.) you are expected to
5329 provide feedback to the other developers. The feedback normally takes
5330 the form of a "patch", i. e. a context diff against a certain (latest
5331 official or latest in the git repository) version of U-Boot sources.
5333 But before you submit such a patch, please verify that your modifi-
5334 cation did not break existing code. At least make sure that *ALL* of
5335 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5336 just run the "MAKEALL" script, which will configure and build U-Boot
5337 for ALL supported system. Be warned, this will take a while. You can
5338 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5339 environment variable to the script, i. e. to use the ELDK cross tools
5342 CROSS_COMPILE=ppc_8xx- MAKEALL
5344 or to build on a native PowerPC system you can type
5346 CROSS_COMPILE=' ' MAKEALL
5348 When using the MAKEALL script, the default behaviour is to build
5349 U-Boot in the source directory. This location can be changed by
5350 setting the BUILD_DIR environment variable. Also, for each target
5351 built, the MAKEALL script saves two log files (<target>.ERR and
5352 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5353 location can be changed by setting the MAKEALL_LOGDIR environment
5354 variable. For example:
5356 export BUILD_DIR=/tmp/build
5357 export MAKEALL_LOGDIR=/tmp/log
5358 CROSS_COMPILE=ppc_8xx- MAKEALL
5360 With the above settings build objects are saved in the /tmp/build,
5361 log files are saved in the /tmp/log and the source tree remains clean
5362 during the whole build process.
5365 See also "U-Boot Porting Guide" below.
5368 Monitor Commands - Overview:
5369 ============================
5371 go - start application at address 'addr'
5372 run - run commands in an environment variable
5373 bootm - boot application image from memory
5374 bootp - boot image via network using BootP/TFTP protocol
5375 bootz - boot zImage from memory
5376 tftpboot- boot image via network using TFTP protocol
5377 and env variables "ipaddr" and "serverip"
5378 (and eventually "gatewayip")
5379 tftpput - upload a file via network using TFTP protocol
5380 rarpboot- boot image via network using RARP/TFTP protocol
5381 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5382 loads - load S-Record file over serial line
5383 loadb - load binary file over serial line (kermit mode)
5385 mm - memory modify (auto-incrementing)
5386 nm - memory modify (constant address)
5387 mw - memory write (fill)
5389 cmp - memory compare
5390 crc32 - checksum calculation
5391 i2c - I2C sub-system
5392 sspi - SPI utility commands
5393 base - print or set address offset
5394 printenv- print environment variables
5395 setenv - set environment variables
5396 saveenv - save environment variables to persistent storage
5397 protect - enable or disable FLASH write protection
5398 erase - erase FLASH memory
5399 flinfo - print FLASH memory information
5400 nand - NAND memory operations (see doc/README.nand)
5401 bdinfo - print Board Info structure
5402 iminfo - print header information for application image
5403 coninfo - print console devices and informations
5404 ide - IDE sub-system
5405 loop - infinite loop on address range
5406 loopw - infinite write loop on address range
5407 mtest - simple RAM test
5408 icache - enable or disable instruction cache
5409 dcache - enable or disable data cache
5410 reset - Perform RESET of the CPU
5411 echo - echo args to console
5412 version - print monitor version
5413 help - print online help
5414 ? - alias for 'help'
5417 Monitor Commands - Detailed Description:
5418 ========================================
5422 For now: just type "help <command>".
5425 Environment Variables:
5426 ======================
5428 U-Boot supports user configuration using Environment Variables which
5429 can be made persistent by saving to Flash memory.
5431 Environment Variables are set using "setenv", printed using
5432 "printenv", and saved to Flash using "saveenv". Using "setenv"
5433 without a value can be used to delete a variable from the
5434 environment. As long as you don't save the environment you are
5435 working with an in-memory copy. In case the Flash area containing the
5436 environment is erased by accident, a default environment is provided.
5438 Some configuration options can be set using Environment Variables.
5440 List of environment variables (most likely not complete):
5442 baudrate - see CONFIG_BAUDRATE
5444 bootdelay - see CONFIG_BOOTDELAY
5446 bootcmd - see CONFIG_BOOTCOMMAND
5448 bootargs - Boot arguments when booting an RTOS image
5450 bootfile - Name of the image to load with TFTP
5452 bootm_low - Memory range available for image processing in the bootm
5453 command can be restricted. This variable is given as
5454 a hexadecimal number and defines lowest address allowed
5455 for use by the bootm command. See also "bootm_size"
5456 environment variable. Address defined by "bootm_low" is
5457 also the base of the initial memory mapping for the Linux
5458 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5461 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5462 This variable is given as a hexadecimal number and it
5463 defines the size of the memory region starting at base
5464 address bootm_low that is accessible by the Linux kernel
5465 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5466 as the default value if it is defined, and bootm_size is
5469 bootm_size - Memory range available for image processing in the bootm
5470 command can be restricted. This variable is given as
5471 a hexadecimal number and defines the size of the region
5472 allowed for use by the bootm command. See also "bootm_low"
5473 environment variable.
5475 updatefile - Location of the software update file on a TFTP server, used
5476 by the automatic software update feature. Please refer to
5477 documentation in doc/README.update for more details.
5479 autoload - if set to "no" (any string beginning with 'n'),
5480 "bootp" will just load perform a lookup of the
5481 configuration from the BOOTP server, but not try to
5482 load any image using TFTP
5484 autostart - if set to "yes", an image loaded using the "bootp",
5485 "rarpboot", "tftpboot" or "diskboot" commands will
5486 be automatically started (by internally calling
5489 If set to "no", a standalone image passed to the
5490 "bootm" command will be copied to the load address
5491 (and eventually uncompressed), but NOT be started.
5492 This can be used to load and uncompress arbitrary
5495 fdt_high - if set this restricts the maximum address that the
5496 flattened device tree will be copied into upon boot.
5497 For example, if you have a system with 1 GB memory
5498 at physical address 0x10000000, while Linux kernel
5499 only recognizes the first 704 MB as low memory, you
5500 may need to set fdt_high as 0x3C000000 to have the
5501 device tree blob be copied to the maximum address
5502 of the 704 MB low memory, so that Linux kernel can
5503 access it during the boot procedure.
5505 If this is set to the special value 0xFFFFFFFF then
5506 the fdt will not be copied at all on boot. For this
5507 to work it must reside in writable memory, have
5508 sufficient padding on the end of it for u-boot to
5509 add the information it needs into it, and the memory
5510 must be accessible by the kernel.
5512 fdtcontroladdr- if set this is the address of the control flattened
5513 device tree used by U-Boot when CONFIG_OF_CONTROL is
5516 i2cfast - (PPC405GP|PPC405EP only)
5517 if set to 'y' configures Linux I2C driver for fast
5518 mode (400kHZ). This environment variable is used in
5519 initialization code. So, for changes to be effective
5520 it must be saved and board must be reset.
5522 initrd_high - restrict positioning of initrd images:
5523 If this variable is not set, initrd images will be
5524 copied to the highest possible address in RAM; this
5525 is usually what you want since it allows for
5526 maximum initrd size. If for some reason you want to
5527 make sure that the initrd image is loaded below the
5528 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5529 variable to a value of "no" or "off" or "0".
5530 Alternatively, you can set it to a maximum upper
5531 address to use (U-Boot will still check that it
5532 does not overwrite the U-Boot stack and data).
5534 For instance, when you have a system with 16 MB
5535 RAM, and want to reserve 4 MB from use by Linux,
5536 you can do this by adding "mem=12M" to the value of
5537 the "bootargs" variable. However, now you must make
5538 sure that the initrd image is placed in the first
5539 12 MB as well - this can be done with
5541 setenv initrd_high 00c00000
5543 If you set initrd_high to 0xFFFFFFFF, this is an
5544 indication to U-Boot that all addresses are legal
5545 for the Linux kernel, including addresses in flash
5546 memory. In this case U-Boot will NOT COPY the
5547 ramdisk at all. This may be useful to reduce the
5548 boot time on your system, but requires that this
5549 feature is supported by your Linux kernel.
5551 ipaddr - IP address; needed for tftpboot command
5553 loadaddr - Default load address for commands like "bootp",
5554 "rarpboot", "tftpboot", "loadb" or "diskboot"
5556 loads_echo - see CONFIG_LOADS_ECHO
5558 serverip - TFTP server IP address; needed for tftpboot command
5560 bootretry - see CONFIG_BOOT_RETRY_TIME
5562 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5564 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5566 ethprime - controls which interface is used first.
5568 ethact - controls which interface is currently active.
5569 For example you can do the following
5571 => setenv ethact FEC
5572 => ping 192.168.0.1 # traffic sent on FEC
5573 => setenv ethact SCC
5574 => ping 10.0.0.1 # traffic sent on SCC
5576 ethrotate - When set to "no" U-Boot does not go through all
5577 available network interfaces.
5578 It just stays at the currently selected interface.
5580 netretry - When set to "no" each network operation will
5581 either succeed or fail without retrying.
5582 When set to "once" the network operation will
5583 fail when all the available network interfaces
5584 are tried once without success.
5585 Useful on scripts which control the retry operation
5588 npe_ucode - set load address for the NPE microcode
5590 silent_linux - If set then Linux will be told to boot silently, by
5591 changing the console to be empty. If "yes" it will be
5592 made silent. If "no" it will not be made silent. If
5593 unset, then it will be made silent if the U-Boot console
5596 tftpsrcport - If this is set, the value is used for TFTP's
5599 tftpdstport - If this is set, the value is used for TFTP's UDP
5600 destination port instead of the Well Know Port 69.
5602 tftpblocksize - Block size to use for TFTP transfers; if not set,
5603 we use the TFTP server's default block size
5605 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5606 seconds, minimum value is 1000 = 1 second). Defines
5607 when a packet is considered to be lost so it has to
5608 be retransmitted. The default is 5000 = 5 seconds.
5609 Lowering this value may make downloads succeed
5610 faster in networks with high packet loss rates or
5611 with unreliable TFTP servers.
5613 vlan - When set to a value < 4095 the traffic over
5614 Ethernet is encapsulated/received over 802.1q
5617 The following image location variables contain the location of images
5618 used in booting. The "Image" column gives the role of the image and is
5619 not an environment variable name. The other columns are environment
5620 variable names. "File Name" gives the name of the file on a TFTP
5621 server, "RAM Address" gives the location in RAM the image will be
5622 loaded to, and "Flash Location" gives the image's address in NOR
5623 flash or offset in NAND flash.
5625 *Note* - these variables don't have to be defined for all boards, some
5626 boards currently use other variables for these purposes, and some
5627 boards use these variables for other purposes.
5629 Image File Name RAM Address Flash Location
5630 ----- --------- ----------- --------------
5631 u-boot u-boot u-boot_addr_r u-boot_addr
5632 Linux kernel bootfile kernel_addr_r kernel_addr
5633 device tree blob fdtfile fdt_addr_r fdt_addr
5634 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5636 The following environment variables may be used and automatically
5637 updated by the network boot commands ("bootp" and "rarpboot"),
5638 depending the information provided by your boot server:
5640 bootfile - see above
5641 dnsip - IP address of your Domain Name Server
5642 dnsip2 - IP address of your secondary Domain Name Server
5643 gatewayip - IP address of the Gateway (Router) to use
5644 hostname - Target hostname
5646 netmask - Subnet Mask
5647 rootpath - Pathname of the root filesystem on the NFS server
5648 serverip - see above
5651 There are two special Environment Variables:
5653 serial# - contains hardware identification information such
5654 as type string and/or serial number
5655 ethaddr - Ethernet address
5657 These variables can be set only once (usually during manufacturing of
5658 the board). U-Boot refuses to delete or overwrite these variables
5659 once they have been set once.
5662 Further special Environment Variables:
5664 ver - Contains the U-Boot version string as printed
5665 with the "version" command. This variable is
5666 readonly (see CONFIG_VERSION_VARIABLE).
5669 Please note that changes to some configuration parameters may take
5670 only effect after the next boot (yes, that's just like Windoze :-).
5673 Callback functions for environment variables:
5674 ---------------------------------------------
5676 For some environment variables, the behavior of u-boot needs to change
5677 when their values are changed. This functionality allows functions to
5678 be associated with arbitrary variables. On creation, overwrite, or
5679 deletion, the callback will provide the opportunity for some side
5680 effect to happen or for the change to be rejected.
5682 The callbacks are named and associated with a function using the
5683 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5685 These callbacks are associated with variables in one of two ways. The
5686 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5687 in the board configuration to a string that defines a list of
5688 associations. The list must be in the following format:
5690 entry = variable_name[:callback_name]
5693 If the callback name is not specified, then the callback is deleted.
5694 Spaces are also allowed anywhere in the list.
5696 Callbacks can also be associated by defining the ".callbacks" variable
5697 with the same list format above. Any association in ".callbacks" will
5698 override any association in the static list. You can define
5699 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5700 ".callbacks" environment variable in the default or embedded environment.
5702 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5703 regular expression. This allows multiple variables to be connected to
5704 the same callback without explicitly listing them all out.
5707 Command Line Parsing:
5708 =====================
5710 There are two different command line parsers available with U-Boot:
5711 the old "simple" one, and the much more powerful "hush" shell:
5713 Old, simple command line parser:
5714 --------------------------------
5716 - supports environment variables (through setenv / saveenv commands)
5717 - several commands on one line, separated by ';'
5718 - variable substitution using "... ${name} ..." syntax
5719 - special characters ('$', ';') can be escaped by prefixing with '\',
5721 setenv bootcmd bootm \${address}
5722 - You can also escape text by enclosing in single apostrophes, for example:
5723 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5728 - similar to Bourne shell, with control structures like
5729 if...then...else...fi, for...do...done; while...do...done,
5730 until...do...done, ...
5731 - supports environment ("global") variables (through setenv / saveenv
5732 commands) and local shell variables (through standard shell syntax
5733 "name=value"); only environment variables can be used with "run"
5739 (1) If a command line (or an environment variable executed by a "run"
5740 command) contains several commands separated by semicolon, and
5741 one of these commands fails, then the remaining commands will be
5744 (2) If you execute several variables with one call to run (i. e.
5745 calling run with a list of variables as arguments), any failing
5746 command will cause "run" to terminate, i. e. the remaining
5747 variables are not executed.
5749 Note for Redundant Ethernet Interfaces:
5750 =======================================
5752 Some boards come with redundant Ethernet interfaces; U-Boot supports
5753 such configurations and is capable of automatic selection of a
5754 "working" interface when needed. MAC assignment works as follows:
5756 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5757 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5758 "eth1addr" (=>eth1), "eth2addr", ...
5760 If the network interface stores some valid MAC address (for instance
5761 in SROM), this is used as default address if there is NO correspon-
5762 ding setting in the environment; if the corresponding environment
5763 variable is set, this overrides the settings in the card; that means:
5765 o If the SROM has a valid MAC address, and there is no address in the
5766 environment, the SROM's address is used.
5768 o If there is no valid address in the SROM, and a definition in the
5769 environment exists, then the value from the environment variable is
5772 o If both the SROM and the environment contain a MAC address, and
5773 both addresses are the same, this MAC address is used.
5775 o If both the SROM and the environment contain a MAC address, and the
5776 addresses differ, the value from the environment is used and a
5779 o If neither SROM nor the environment contain a MAC address, an error
5780 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5781 a random, locally-assigned MAC is used.
5783 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5784 will be programmed into hardware as part of the initialization process. This
5785 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5786 The naming convention is as follows:
5787 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5792 U-Boot is capable of booting (and performing other auxiliary operations on)
5793 images in two formats:
5795 New uImage format (FIT)
5796 -----------------------
5798 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5799 to Flattened Device Tree). It allows the use of images with multiple
5800 components (several kernels, ramdisks, etc.), with contents protected by
5801 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5807 Old image format is based on binary files which can be basically anything,
5808 preceded by a special header; see the definitions in include/image.h for
5809 details; basically, the header defines the following image properties:
5811 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5812 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5813 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5814 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5816 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5817 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5818 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5819 * Compression Type (uncompressed, gzip, bzip2)
5825 The header is marked by a special Magic Number, and both the header
5826 and the data portions of the image are secured against corruption by
5833 Although U-Boot should support any OS or standalone application
5834 easily, the main focus has always been on Linux during the design of
5837 U-Boot includes many features that so far have been part of some
5838 special "boot loader" code within the Linux kernel. Also, any
5839 "initrd" images to be used are no longer part of one big Linux image;
5840 instead, kernel and "initrd" are separate images. This implementation
5841 serves several purposes:
5843 - the same features can be used for other OS or standalone
5844 applications (for instance: using compressed images to reduce the
5845 Flash memory footprint)
5847 - it becomes much easier to port new Linux kernel versions because
5848 lots of low-level, hardware dependent stuff are done by U-Boot
5850 - the same Linux kernel image can now be used with different "initrd"
5851 images; of course this also means that different kernel images can
5852 be run with the same "initrd". This makes testing easier (you don't
5853 have to build a new "zImage.initrd" Linux image when you just
5854 change a file in your "initrd"). Also, a field-upgrade of the
5855 software is easier now.
5861 Porting Linux to U-Boot based systems:
5862 ---------------------------------------
5864 U-Boot cannot save you from doing all the necessary modifications to
5865 configure the Linux device drivers for use with your target hardware
5866 (no, we don't intend to provide a full virtual machine interface to
5869 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5871 Just make sure your machine specific header file (for instance
5872 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5873 Information structure as we define in include/asm-<arch>/u-boot.h,
5874 and make sure that your definition of IMAP_ADDR uses the same value
5875 as your U-Boot configuration in CONFIG_SYS_IMMR.
5877 Note that U-Boot now has a driver model, a unified model for drivers.
5878 If you are adding a new driver, plumb it into driver model. If there
5879 is no uclass available, you are encouraged to create one. See
5883 Configuring the Linux kernel:
5884 -----------------------------
5886 No specific requirements for U-Boot. Make sure you have some root
5887 device (initial ramdisk, NFS) for your target system.
5890 Building a Linux Image:
5891 -----------------------
5893 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5894 not used. If you use recent kernel source, a new build target
5895 "uImage" will exist which automatically builds an image usable by
5896 U-Boot. Most older kernels also have support for a "pImage" target,
5897 which was introduced for our predecessor project PPCBoot and uses a
5898 100% compatible format.
5902 make TQM850L_defconfig
5907 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5908 encapsulate a compressed Linux kernel image with header information,
5909 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5911 * build a standard "vmlinux" kernel image (in ELF binary format):
5913 * convert the kernel into a raw binary image:
5915 ${CROSS_COMPILE}-objcopy -O binary \
5916 -R .note -R .comment \
5917 -S vmlinux linux.bin
5919 * compress the binary image:
5923 * package compressed binary image for U-Boot:
5925 mkimage -A ppc -O linux -T kernel -C gzip \
5926 -a 0 -e 0 -n "Linux Kernel Image" \
5927 -d linux.bin.gz uImage
5930 The "mkimage" tool can also be used to create ramdisk images for use
5931 with U-Boot, either separated from the Linux kernel image, or
5932 combined into one file. "mkimage" encapsulates the images with a 64
5933 byte header containing information about target architecture,
5934 operating system, image type, compression method, entry points, time
5935 stamp, CRC32 checksums, etc.
5937 "mkimage" can be called in two ways: to verify existing images and
5938 print the header information, or to build new images.
5940 In the first form (with "-l" option) mkimage lists the information
5941 contained in the header of an existing U-Boot image; this includes
5942 checksum verification:
5944 tools/mkimage -l image
5945 -l ==> list image header information
5947 The second form (with "-d" option) is used to build a U-Boot image
5948 from a "data file" which is used as image payload:
5950 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5951 -n name -d data_file image
5952 -A ==> set architecture to 'arch'
5953 -O ==> set operating system to 'os'
5954 -T ==> set image type to 'type'
5955 -C ==> set compression type 'comp'
5956 -a ==> set load address to 'addr' (hex)
5957 -e ==> set entry point to 'ep' (hex)
5958 -n ==> set image name to 'name'
5959 -d ==> use image data from 'datafile'
5961 Right now, all Linux kernels for PowerPC systems use the same load
5962 address (0x00000000), but the entry point address depends on the
5965 - 2.2.x kernels have the entry point at 0x0000000C,
5966 - 2.3.x and later kernels have the entry point at 0x00000000.
5968 So a typical call to build a U-Boot image would read:
5970 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5971 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5972 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5973 > examples/uImage.TQM850L
5974 Image Name: 2.4.4 kernel for TQM850L
5975 Created: Wed Jul 19 02:34:59 2000
5976 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5977 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5978 Load Address: 0x00000000
5979 Entry Point: 0x00000000
5981 To verify the contents of the image (or check for corruption):
5983 -> tools/mkimage -l examples/uImage.TQM850L
5984 Image Name: 2.4.4 kernel for TQM850L
5985 Created: Wed Jul 19 02:34:59 2000
5986 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5987 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5988 Load Address: 0x00000000
5989 Entry Point: 0x00000000
5991 NOTE: for embedded systems where boot time is critical you can trade
5992 speed for memory and install an UNCOMPRESSED image instead: this
5993 needs more space in Flash, but boots much faster since it does not
5994 need to be uncompressed:
5996 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5997 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5998 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5999 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
6000 > examples/uImage.TQM850L-uncompressed
6001 Image Name: 2.4.4 kernel for TQM850L
6002 Created: Wed Jul 19 02:34:59 2000
6003 Image Type: PowerPC Linux Kernel Image (uncompressed)
6004 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
6005 Load Address: 0x00000000
6006 Entry Point: 0x00000000
6009 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
6010 when your kernel is intended to use an initial ramdisk:
6012 -> tools/mkimage -n 'Simple Ramdisk Image' \
6013 > -A ppc -O linux -T ramdisk -C gzip \
6014 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
6015 Image Name: Simple Ramdisk Image
6016 Created: Wed Jan 12 14:01:50 2000
6017 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6018 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6019 Load Address: 0x00000000
6020 Entry Point: 0x00000000
6022 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6023 option performs the converse operation of the mkimage's second form (the "-d"
6024 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6027 tools/dumpimage -i image -T type -p position data_file
6028 -i ==> extract from the 'image' a specific 'data_file'
6029 -T ==> set image type to 'type'
6030 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6033 Installing a Linux Image:
6034 -------------------------
6036 To downloading a U-Boot image over the serial (console) interface,
6037 you must convert the image to S-Record format:
6039 objcopy -I binary -O srec examples/image examples/image.srec
6041 The 'objcopy' does not understand the information in the U-Boot
6042 image header, so the resulting S-Record file will be relative to
6043 address 0x00000000. To load it to a given address, you need to
6044 specify the target address as 'offset' parameter with the 'loads'
6047 Example: install the image to address 0x40100000 (which on the
6048 TQM8xxL is in the first Flash bank):
6050 => erase 40100000 401FFFFF
6056 ## Ready for S-Record download ...
6057 ~>examples/image.srec
6058 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6060 15989 15990 15991 15992
6061 [file transfer complete]
6063 ## Start Addr = 0x00000000
6066 You can check the success of the download using the 'iminfo' command;
6067 this includes a checksum verification so you can be sure no data
6068 corruption happened:
6072 ## Checking Image at 40100000 ...
6073 Image Name: 2.2.13 for initrd on TQM850L
6074 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6075 Data Size: 335725 Bytes = 327 kB = 0 MB
6076 Load Address: 00000000
6077 Entry Point: 0000000c
6078 Verifying Checksum ... OK
6084 The "bootm" command is used to boot an application that is stored in
6085 memory (RAM or Flash). In case of a Linux kernel image, the contents
6086 of the "bootargs" environment variable is passed to the kernel as
6087 parameters. You can check and modify this variable using the
6088 "printenv" and "setenv" commands:
6091 => printenv bootargs
6092 bootargs=root=/dev/ram
6094 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6096 => printenv bootargs
6097 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6100 ## Booting Linux kernel at 40020000 ...
6101 Image Name: 2.2.13 for NFS on TQM850L
6102 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6103 Data Size: 381681 Bytes = 372 kB = 0 MB
6104 Load Address: 00000000
6105 Entry Point: 0000000c
6106 Verifying Checksum ... OK
6107 Uncompressing Kernel Image ... OK
6108 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
6109 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6110 time_init: decrementer frequency = 187500000/60
6111 Calibrating delay loop... 49.77 BogoMIPS
6112 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6115 If you want to boot a Linux kernel with initial RAM disk, you pass
6116 the memory addresses of both the kernel and the initrd image (PPBCOOT
6117 format!) to the "bootm" command:
6119 => imi 40100000 40200000
6121 ## Checking Image at 40100000 ...
6122 Image Name: 2.2.13 for initrd on TQM850L
6123 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6124 Data Size: 335725 Bytes = 327 kB = 0 MB
6125 Load Address: 00000000
6126 Entry Point: 0000000c
6127 Verifying Checksum ... OK
6129 ## Checking Image at 40200000 ...
6130 Image Name: Simple Ramdisk Image
6131 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6132 Data Size: 566530 Bytes = 553 kB = 0 MB
6133 Load Address: 00000000
6134 Entry Point: 00000000
6135 Verifying Checksum ... OK
6137 => bootm 40100000 40200000
6138 ## Booting Linux kernel at 40100000 ...
6139 Image Name: 2.2.13 for initrd on TQM850L
6140 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6141 Data Size: 335725 Bytes = 327 kB = 0 MB
6142 Load Address: 00000000
6143 Entry Point: 0000000c
6144 Verifying Checksum ... OK
6145 Uncompressing Kernel Image ... OK
6146 ## Loading RAMDisk Image at 40200000 ...
6147 Image Name: Simple Ramdisk Image
6148 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6149 Data Size: 566530 Bytes = 553 kB = 0 MB
6150 Load Address: 00000000
6151 Entry Point: 00000000
6152 Verifying Checksum ... OK
6153 Loading Ramdisk ... OK
6154 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
6155 Boot arguments: root=/dev/ram
6156 time_init: decrementer frequency = 187500000/60
6157 Calibrating delay loop... 49.77 BogoMIPS
6159 RAMDISK: Compressed image found at block 0
6160 VFS: Mounted root (ext2 filesystem).
6164 Boot Linux and pass a flat device tree:
6167 First, U-Boot must be compiled with the appropriate defines. See the section
6168 titled "Linux Kernel Interface" above for a more in depth explanation. The
6169 following is an example of how to start a kernel and pass an updated
6175 oft=oftrees/mpc8540ads.dtb
6176 => tftp $oftaddr $oft
6177 Speed: 1000, full duplex
6179 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6180 Filename 'oftrees/mpc8540ads.dtb'.
6181 Load address: 0x300000
6184 Bytes transferred = 4106 (100a hex)
6185 => tftp $loadaddr $bootfile
6186 Speed: 1000, full duplex
6188 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6190 Load address: 0x200000
6191 Loading:############
6193 Bytes transferred = 1029407 (fb51f hex)
6198 => bootm $loadaddr - $oftaddr
6199 ## Booting image at 00200000 ...
6200 Image Name: Linux-2.6.17-dirty
6201 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6202 Data Size: 1029343 Bytes = 1005.2 kB
6203 Load Address: 00000000
6204 Entry Point: 00000000
6205 Verifying Checksum ... OK
6206 Uncompressing Kernel Image ... OK
6207 Booting using flat device tree at 0x300000
6208 Using MPC85xx ADS machine description
6209 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6213 More About U-Boot Image Types:
6214 ------------------------------
6216 U-Boot supports the following image types:
6218 "Standalone Programs" are directly runnable in the environment
6219 provided by U-Boot; it is expected that (if they behave
6220 well) you can continue to work in U-Boot after return from
6221 the Standalone Program.
6222 "OS Kernel Images" are usually images of some Embedded OS which
6223 will take over control completely. Usually these programs
6224 will install their own set of exception handlers, device
6225 drivers, set up the MMU, etc. - this means, that you cannot
6226 expect to re-enter U-Boot except by resetting the CPU.
6227 "RAMDisk Images" are more or less just data blocks, and their
6228 parameters (address, size) are passed to an OS kernel that is
6230 "Multi-File Images" contain several images, typically an OS
6231 (Linux) kernel image and one or more data images like
6232 RAMDisks. This construct is useful for instance when you want
6233 to boot over the network using BOOTP etc., where the boot
6234 server provides just a single image file, but you want to get
6235 for instance an OS kernel and a RAMDisk image.
6237 "Multi-File Images" start with a list of image sizes, each
6238 image size (in bytes) specified by an "uint32_t" in network
6239 byte order. This list is terminated by an "(uint32_t)0".
6240 Immediately after the terminating 0 follow the images, one by
6241 one, all aligned on "uint32_t" boundaries (size rounded up to
6242 a multiple of 4 bytes).
6244 "Firmware Images" are binary images containing firmware (like
6245 U-Boot or FPGA images) which usually will be programmed to
6248 "Script files" are command sequences that will be executed by
6249 U-Boot's command interpreter; this feature is especially
6250 useful when you configure U-Boot to use a real shell (hush)
6251 as command interpreter.
6253 Booting the Linux zImage:
6254 -------------------------
6256 On some platforms, it's possible to boot Linux zImage. This is done
6257 using the "bootz" command. The syntax of "bootz" command is the same
6258 as the syntax of "bootm" command.
6260 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6261 kernel with raw initrd images. The syntax is slightly different, the
6262 address of the initrd must be augmented by it's size, in the following
6263 format: "<initrd addres>:<initrd size>".
6269 One of the features of U-Boot is that you can dynamically load and
6270 run "standalone" applications, which can use some resources of
6271 U-Boot like console I/O functions or interrupt services.
6273 Two simple examples are included with the sources:
6278 'examples/hello_world.c' contains a small "Hello World" Demo
6279 application; it is automatically compiled when you build U-Boot.
6280 It's configured to run at address 0x00040004, so you can play with it
6284 ## Ready for S-Record download ...
6285 ~>examples/hello_world.srec
6286 1 2 3 4 5 6 7 8 9 10 11 ...
6287 [file transfer complete]
6289 ## Start Addr = 0x00040004
6291 => go 40004 Hello World! This is a test.
6292 ## Starting application at 0x00040004 ...
6303 Hit any key to exit ...
6305 ## Application terminated, rc = 0x0
6307 Another example, which demonstrates how to register a CPM interrupt
6308 handler with the U-Boot code, can be found in 'examples/timer.c'.
6309 Here, a CPM timer is set up to generate an interrupt every second.
6310 The interrupt service routine is trivial, just printing a '.'
6311 character, but this is just a demo program. The application can be
6312 controlled by the following keys:
6314 ? - print current values og the CPM Timer registers
6315 b - enable interrupts and start timer
6316 e - stop timer and disable interrupts
6317 q - quit application
6320 ## Ready for S-Record download ...
6321 ~>examples/timer.srec
6322 1 2 3 4 5 6 7 8 9 10 11 ...
6323 [file transfer complete]
6325 ## Start Addr = 0x00040004
6328 ## Starting application at 0x00040004 ...
6331 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6334 [q, b, e, ?] Set interval 1000000 us
6337 [q, b, e, ?] ........
6338 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6341 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6344 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6347 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6349 [q, b, e, ?] ...Stopping timer
6351 [q, b, e, ?] ## Application terminated, rc = 0x0
6357 Over time, many people have reported problems when trying to use the
6358 "minicom" terminal emulation program for serial download. I (wd)
6359 consider minicom to be broken, and recommend not to use it. Under
6360 Unix, I recommend to use C-Kermit for general purpose use (and
6361 especially for kermit binary protocol download ("loadb" command), and
6362 use "cu" for S-Record download ("loads" command). See
6363 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6364 for help with kermit.
6367 Nevertheless, if you absolutely want to use it try adding this
6368 configuration to your "File transfer protocols" section:
6370 Name Program Name U/D FullScr IO-Red. Multi
6371 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6372 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6378 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6379 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6381 Building requires a cross environment; it is known to work on
6382 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6383 need gmake since the Makefiles are not compatible with BSD make).
6384 Note that the cross-powerpc package does not install include files;
6385 attempting to build U-Boot will fail because <machine/ansi.h> is
6386 missing. This file has to be installed and patched manually:
6388 # cd /usr/pkg/cross/powerpc-netbsd/include
6390 # ln -s powerpc machine
6391 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6392 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6394 Native builds *don't* work due to incompatibilities between native
6395 and U-Boot include files.
6397 Booting assumes that (the first part of) the image booted is a
6398 stage-2 loader which in turn loads and then invokes the kernel
6399 proper. Loader sources will eventually appear in the NetBSD source
6400 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6401 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6404 Implementation Internals:
6405 =========================
6407 The following is not intended to be a complete description of every
6408 implementation detail. However, it should help to understand the
6409 inner workings of U-Boot and make it easier to port it to custom
6413 Initial Stack, Global Data:
6414 ---------------------------
6416 The implementation of U-Boot is complicated by the fact that U-Boot
6417 starts running out of ROM (flash memory), usually without access to
6418 system RAM (because the memory controller is not initialized yet).
6419 This means that we don't have writable Data or BSS segments, and BSS
6420 is not initialized as zero. To be able to get a C environment working
6421 at all, we have to allocate at least a minimal stack. Implementation
6422 options for this are defined and restricted by the CPU used: Some CPU
6423 models provide on-chip memory (like the IMMR area on MPC8xx and
6424 MPC826x processors), on others (parts of) the data cache can be
6425 locked as (mis-) used as memory, etc.
6427 Chris Hallinan posted a good summary of these issues to the
6428 U-Boot mailing list:
6430 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6431 From: "Chris Hallinan" <clh@net1plus.com>
6432 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6435 Correct me if I'm wrong, folks, but the way I understand it
6436 is this: Using DCACHE as initial RAM for Stack, etc, does not
6437 require any physical RAM backing up the cache. The cleverness
6438 is that the cache is being used as a temporary supply of
6439 necessary storage before the SDRAM controller is setup. It's
6440 beyond the scope of this list to explain the details, but you
6441 can see how this works by studying the cache architecture and
6442 operation in the architecture and processor-specific manuals.
6444 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6445 is another option for the system designer to use as an
6446 initial stack/RAM area prior to SDRAM being available. Either
6447 option should work for you. Using CS 4 should be fine if your
6448 board designers haven't used it for something that would
6449 cause you grief during the initial boot! It is frequently not
6452 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6453 with your processor/board/system design. The default value
6454 you will find in any recent u-boot distribution in
6455 walnut.h should work for you. I'd set it to a value larger
6456 than your SDRAM module. If you have a 64MB SDRAM module, set
6457 it above 400_0000. Just make sure your board has no resources
6458 that are supposed to respond to that address! That code in
6459 start.S has been around a while and should work as is when
6460 you get the config right.
6465 It is essential to remember this, since it has some impact on the C
6466 code for the initialization procedures:
6468 * Initialized global data (data segment) is read-only. Do not attempt
6471 * Do not use any uninitialized global data (or implicitly initialized
6472 as zero data - BSS segment) at all - this is undefined, initiali-
6473 zation is performed later (when relocating to RAM).
6475 * Stack space is very limited. Avoid big data buffers or things like
6478 Having only the stack as writable memory limits means we cannot use
6479 normal global data to share information between the code. But it
6480 turned out that the implementation of U-Boot can be greatly
6481 simplified by making a global data structure (gd_t) available to all
6482 functions. We could pass a pointer to this data as argument to _all_
6483 functions, but this would bloat the code. Instead we use a feature of
6484 the GCC compiler (Global Register Variables) to share the data: we
6485 place a pointer (gd) to the global data into a register which we
6486 reserve for this purpose.
6488 When choosing a register for such a purpose we are restricted by the
6489 relevant (E)ABI specifications for the current architecture, and by
6490 GCC's implementation.
6492 For PowerPC, the following registers have specific use:
6494 R2: reserved for system use
6495 R3-R4: parameter passing and return values
6496 R5-R10: parameter passing
6497 R13: small data area pointer
6501 (U-Boot also uses R12 as internal GOT pointer. r12
6502 is a volatile register so r12 needs to be reset when
6503 going back and forth between asm and C)
6505 ==> U-Boot will use R2 to hold a pointer to the global data
6507 Note: on PPC, we could use a static initializer (since the
6508 address of the global data structure is known at compile time),
6509 but it turned out that reserving a register results in somewhat
6510 smaller code - although the code savings are not that big (on
6511 average for all boards 752 bytes for the whole U-Boot image,
6512 624 text + 127 data).
6514 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6515 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6517 ==> U-Boot will use P3 to hold a pointer to the global data
6519 On ARM, the following registers are used:
6521 R0: function argument word/integer result
6522 R1-R3: function argument word
6523 R9: platform specific
6524 R10: stack limit (used only if stack checking is enabled)
6525 R11: argument (frame) pointer
6526 R12: temporary workspace
6529 R15: program counter
6531 ==> U-Boot will use R9 to hold a pointer to the global data
6533 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6535 On Nios II, the ABI is documented here:
6536 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6538 ==> U-Boot will use gp to hold a pointer to the global data
6540 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6541 to access small data sections, so gp is free.
6543 On NDS32, the following registers are used:
6545 R0-R1: argument/return
6547 R15: temporary register for assembler
6548 R16: trampoline register
6549 R28: frame pointer (FP)
6550 R29: global pointer (GP)
6551 R30: link register (LP)
6552 R31: stack pointer (SP)
6553 PC: program counter (PC)
6555 ==> U-Boot will use R10 to hold a pointer to the global data
6557 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6558 or current versions of GCC may "optimize" the code too much.
6563 U-Boot runs in system state and uses physical addresses, i.e. the
6564 MMU is not used either for address mapping nor for memory protection.
6566 The available memory is mapped to fixed addresses using the memory
6567 controller. In this process, a contiguous block is formed for each
6568 memory type (Flash, SDRAM, SRAM), even when it consists of several
6569 physical memory banks.
6571 U-Boot is installed in the first 128 kB of the first Flash bank (on
6572 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6573 booting and sizing and initializing DRAM, the code relocates itself
6574 to the upper end of DRAM. Immediately below the U-Boot code some
6575 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6576 configuration setting]. Below that, a structure with global Board
6577 Info data is placed, followed by the stack (growing downward).
6579 Additionally, some exception handler code is copied to the low 8 kB
6580 of DRAM (0x00000000 ... 0x00001FFF).
6582 So a typical memory configuration with 16 MB of DRAM could look like
6585 0x0000 0000 Exception Vector code
6588 0x0000 2000 Free for Application Use
6594 0x00FB FF20 Monitor Stack (Growing downward)
6595 0x00FB FFAC Board Info Data and permanent copy of global data
6596 0x00FC 0000 Malloc Arena
6599 0x00FE 0000 RAM Copy of Monitor Code
6600 ... eventually: LCD or video framebuffer
6601 ... eventually: pRAM (Protected RAM - unchanged by reset)
6602 0x00FF FFFF [End of RAM]
6605 System Initialization:
6606 ----------------------
6608 In the reset configuration, U-Boot starts at the reset entry point
6609 (on most PowerPC systems at address 0x00000100). Because of the reset
6610 configuration for CS0# this is a mirror of the on board Flash memory.
6611 To be able to re-map memory U-Boot then jumps to its link address.
6612 To be able to implement the initialization code in C, a (small!)
6613 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6614 which provide such a feature like MPC8xx or MPC8260), or in a locked
6615 part of the data cache. After that, U-Boot initializes the CPU core,
6616 the caches and the SIU.
6618 Next, all (potentially) available memory banks are mapped using a
6619 preliminary mapping. For example, we put them on 512 MB boundaries
6620 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6621 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6622 programmed for SDRAM access. Using the temporary configuration, a
6623 simple memory test is run that determines the size of the SDRAM
6626 When there is more than one SDRAM bank, and the banks are of
6627 different size, the largest is mapped first. For equal size, the first
6628 bank (CS2#) is mapped first. The first mapping is always for address
6629 0x00000000, with any additional banks following immediately to create
6630 contiguous memory starting from 0.
6632 Then, the monitor installs itself at the upper end of the SDRAM area
6633 and allocates memory for use by malloc() and for the global Board
6634 Info data; also, the exception vector code is copied to the low RAM
6635 pages, and the final stack is set up.
6637 Only after this relocation will you have a "normal" C environment;
6638 until that you are restricted in several ways, mostly because you are
6639 running from ROM, and because the code will have to be relocated to a
6643 U-Boot Porting Guide:
6644 ----------------------
6646 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6650 int main(int argc, char *argv[])
6652 sighandler_t no_more_time;
6654 signal(SIGALRM, no_more_time);
6655 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6657 if (available_money > available_manpower) {
6658 Pay consultant to port U-Boot;
6662 Download latest U-Boot source;
6664 Subscribe to u-boot mailing list;
6667 email("Hi, I am new to U-Boot, how do I get started?");
6670 Read the README file in the top level directory;
6671 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6672 Read applicable doc/*.README;
6673 Read the source, Luke;
6674 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6677 if (available_money > toLocalCurrency ($2500))
6680 Add a lot of aggravation and time;
6682 if (a similar board exists) { /* hopefully... */
6683 cp -a board/<similar> board/<myboard>
6684 cp include/configs/<similar>.h include/configs/<myboard>.h
6686 Create your own board support subdirectory;
6687 Create your own board include/configs/<myboard>.h file;
6689 Edit new board/<myboard> files
6690 Edit new include/configs/<myboard>.h
6695 Add / modify source code;
6699 email("Hi, I am having problems...");
6701 Send patch file to the U-Boot email list;
6702 if (reasonable critiques)
6703 Incorporate improvements from email list code review;
6705 Defend code as written;
6711 void no_more_time (int sig)
6720 All contributions to U-Boot should conform to the Linux kernel
6721 coding style; see the file "Documentation/CodingStyle" and the script
6722 "scripts/Lindent" in your Linux kernel source directory.
6724 Source files originating from a different project (for example the
6725 MTD subsystem) are generally exempt from these guidelines and are not
6726 reformatted to ease subsequent migration to newer versions of those
6729 Please note that U-Boot is implemented in C (and to some small parts in
6730 Assembler); no C++ is used, so please do not use C++ style comments (//)
6733 Please also stick to the following formatting rules:
6734 - remove any trailing white space
6735 - use TAB characters for indentation and vertical alignment, not spaces
6736 - make sure NOT to use DOS '\r\n' line feeds
6737 - do not add more than 2 consecutive empty lines to source files
6738 - do not add trailing empty lines to source files
6740 Submissions which do not conform to the standards may be returned
6741 with a request to reformat the changes.
6747 Since the number of patches for U-Boot is growing, we need to
6748 establish some rules. Submissions which do not conform to these rules
6749 may be rejected, even when they contain important and valuable stuff.
6751 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6753 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6754 see http://lists.denx.de/mailman/listinfo/u-boot
6756 When you send a patch, please include the following information with
6759 * For bug fixes: a description of the bug and how your patch fixes
6760 this bug. Please try to include a way of demonstrating that the
6761 patch actually fixes something.
6763 * For new features: a description of the feature and your
6766 * A CHANGELOG entry as plaintext (separate from the patch)
6768 * For major contributions, your entry to the CREDITS file
6770 * When you add support for a new board, don't forget to add a
6771 maintainer e-mail address to the boards.cfg file, too.
6773 * If your patch adds new configuration options, don't forget to
6774 document these in the README file.
6776 * The patch itself. If you are using git (which is *strongly*
6777 recommended) you can easily generate the patch using the
6778 "git format-patch". If you then use "git send-email" to send it to
6779 the U-Boot mailing list, you will avoid most of the common problems
6780 with some other mail clients.
6782 If you cannot use git, use "diff -purN OLD NEW". If your version of
6783 diff does not support these options, then get the latest version of
6786 The current directory when running this command shall be the parent
6787 directory of the U-Boot source tree (i. e. please make sure that
6788 your patch includes sufficient directory information for the
6791 We prefer patches as plain text. MIME attachments are discouraged,
6792 and compressed attachments must not be used.
6794 * If one logical set of modifications affects or creates several
6795 files, all these changes shall be submitted in a SINGLE patch file.
6797 * Changesets that contain different, unrelated modifications shall be
6798 submitted as SEPARATE patches, one patch per changeset.
6803 * Before sending the patch, run the MAKEALL script on your patched
6804 source tree and make sure that no errors or warnings are reported
6805 for any of the boards.
6807 * Keep your modifications to the necessary minimum: A patch
6808 containing several unrelated changes or arbitrary reformats will be
6809 returned with a request to re-formatting / split it.
6811 * If you modify existing code, make sure that your new code does not
6812 add to the memory footprint of the code ;-) Small is beautiful!
6813 When adding new features, these should compile conditionally only
6814 (using #ifdef), and the resulting code with the new feature
6815 disabled must not need more memory than the old code without your
6818 * Remember that there is a size limit of 100 kB per message on the
6819 u-boot mailing list. Bigger patches will be moderated. If they are
6820 reasonable and not too big, they will be acknowledged. But patches
6821 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob