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 Driver model is a new framework for devices in U-Boot
695 introduced in early 2014. U-Boot is being progressively
696 moved over to this. It offers a consistent device structure,
697 supports grouping devices into classes and has built-in
698 handling of platform data and device tree.
700 To enable transition to driver model in a relatively
701 painful fashion, each subsystem can be independently
702 switched between the legacy/ad-hoc approach and the new
703 driver model using the options below. Also, many uclass
704 interfaces include compatibility features which may be
705 removed once the conversion of that subsystem is complete.
706 As a result, the API provided by the subsystem may in fact
707 not change with driver model.
709 See doc/driver-model/README.txt for more information.
713 Enable driver model. This brings in the core support,
714 including scanning of platform data on start-up. If
715 CONFIG_OF_CONTROL is enabled, the device tree will be
716 scanned also when available.
720 Enable driver model test commands. These allow you to print
721 out the driver model tree and the uclasses.
725 Enable some demo devices and the 'demo' command. These are
726 really only useful for playing around while trying to
727 understand driver model in sandbox.
731 Enable driver model in SPL. You will need to provide a
732 suitable malloc() implementation. If you are not using the
733 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
734 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
735 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
736 In most cases driver model will only allocate a few uclasses
737 and devices in SPL, so 1KB should be enable. See
738 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
743 Enable driver model for serial. This replaces
744 drivers/serial/serial.c with the serial uclass, which
745 implements serial_putc() etc. The uclass interface is
746 defined in include/serial.h.
750 Enable driver model for GPIO access. The standard GPIO
751 interface (gpio_get_value(), etc.) is then implemented by
752 the GPIO uclass. Drivers provide methods to query the
753 particular GPIOs that they provide. The uclass interface
754 is defined in include/asm-generic/gpio.h.
758 Enable driver model for SPI. The SPI slave interface
759 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
760 the SPI uclass. Drivers provide methods to access the SPI
761 buses that they control. The uclass interface is defined in
762 include/spi.h. The existing spi_slave structure is attached
763 as 'parent data' to every slave on each bus. Slaves
764 typically use driver-private data instead of extending the
769 Enable driver model for SPI flash. This SPI flash interface
770 (spi_flash_probe(), spi_flash_write(), etc.) is then
771 implemented by the SPI flash uclass. There is one standard
772 SPI flash driver which knows how to probe most chips
773 supported by U-Boot. The uclass interface is defined in
774 include/spi_flash.h, but is currently fully compatible
775 with the old interface to avoid confusion and duplication
776 during the transition parent. SPI and SPI flash must be
777 enabled together (it is not possible to use driver model
778 for one and not the other).
782 Enable driver model for the Chrome OS EC interface. This
783 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
784 but otherwise makes few changes. Since cros_ec also supports
785 I2C and LPC (which don't support driver model yet), a full
786 conversion is not yet possible.
789 ** Code size options: The following options are enabled by
790 default except in SPL. Enable them explicitly to get these
795 Enable the dm_warn() function. This can use up quite a bit
796 of space for its strings.
800 Enable registering a serial device with the stdio library.
802 CONFIG_DM_DEVICE_REMOVE
804 Enable removing of devices.
807 - Linux Kernel Interface:
810 U-Boot stores all clock information in Hz
811 internally. For binary compatibility with older Linux
812 kernels (which expect the clocks passed in the
813 bd_info data to be in MHz) the environment variable
814 "clocks_in_mhz" can be defined so that U-Boot
815 converts clock data to MHZ before passing it to the
817 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
818 "clocks_in_mhz=1" is automatically included in the
821 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
823 When transferring memsize parameter to Linux, some versions
824 expect it to be in bytes, others in MB.
825 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
829 New kernel versions are expecting firmware settings to be
830 passed using flattened device trees (based on open firmware
834 * New libfdt-based support
835 * Adds the "fdt" command
836 * The bootm command automatically updates the fdt
838 OF_CPU - The proper name of the cpus node (only required for
839 MPC512X and MPC5xxx based boards).
840 OF_SOC - The proper name of the soc node (only required for
841 MPC512X and MPC5xxx based boards).
842 OF_TBCLK - The timebase frequency.
843 OF_STDOUT_PATH - The path to the console device
845 boards with QUICC Engines require OF_QE to set UCC MAC
848 CONFIG_OF_BOARD_SETUP
850 Board code has addition modification that it wants to make
851 to the flat device tree before handing it off to the kernel
853 CONFIG_OF_SYSTEM_SETUP
855 Other code has addition modification that it wants to make
856 to the flat device tree before handing it off to the kernel.
857 This causes ft_system_setup() to be called before booting
862 This define fills in the correct boot CPU in the boot
863 param header, the default value is zero if undefined.
867 U-Boot can detect if an IDE device is present or not.
868 If not, and this new config option is activated, U-Boot
869 removes the ATA node from the DTS before booting Linux,
870 so the Linux IDE driver does not probe the device and
871 crash. This is needed for buggy hardware (uc101) where
872 no pull down resistor is connected to the signal IDE5V_DD7.
874 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
876 This setting is mandatory for all boards that have only one
877 machine type and must be used to specify the machine type
878 number as it appears in the ARM machine registry
879 (see http://www.arm.linux.org.uk/developer/machines/).
880 Only boards that have multiple machine types supported
881 in a single configuration file and the machine type is
882 runtime discoverable, do not have to use this setting.
884 - vxWorks boot parameters:
886 bootvx constructs a valid bootline using the following
887 environments variables: bootfile, ipaddr, serverip, hostname.
888 It loads the vxWorks image pointed bootfile.
890 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
891 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
892 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
893 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
895 CONFIG_SYS_VXWORKS_ADD_PARAMS
897 Add it at the end of the bootline. E.g "u=username pw=secret"
899 Note: If a "bootargs" environment is defined, it will overwride
900 the defaults discussed just above.
902 - Cache Configuration:
903 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
904 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
905 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
907 - Cache Configuration for ARM:
908 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
910 CONFIG_SYS_PL310_BASE - Physical base address of PL310
911 controller register space
916 Define this if you want support for Amba PrimeCell PL010 UARTs.
920 Define this if you want support for Amba PrimeCell PL011 UARTs.
924 If you have Amba PrimeCell PL011 UARTs, set this variable to
925 the clock speed of the UARTs.
929 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
930 define this to a list of base addresses for each (supported)
931 port. See e.g. include/configs/versatile.h
933 CONFIG_PL011_SERIAL_RLCR
935 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
936 have separate receive and transmit line control registers. Set
937 this variable to initialize the extra register.
939 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
941 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
942 boot loader that has already initialized the UART. Define this
943 variable to flush the UART at init time.
945 CONFIG_SERIAL_HW_FLOW_CONTROL
947 Define this variable to enable hw flow control in serial driver.
948 Current user of this option is drivers/serial/nsl16550.c driver
951 Depending on board, define exactly one serial port
952 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
953 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
954 console by defining CONFIG_8xx_CONS_NONE
956 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
957 port routines must be defined elsewhere
958 (i.e. serial_init(), serial_getc(), ...)
961 Enables console device for a color framebuffer. Needs following
962 defines (cf. smiLynxEM, i8042)
963 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
965 VIDEO_HW_RECTFILL graphic chip supports
968 VIDEO_HW_BITBLT graphic chip supports
969 bit-blit (cf. smiLynxEM)
970 VIDEO_VISIBLE_COLS visible pixel columns
972 VIDEO_VISIBLE_ROWS visible pixel rows
973 VIDEO_PIXEL_SIZE bytes per pixel
974 VIDEO_DATA_FORMAT graphic data format
975 (0-5, cf. cfb_console.c)
976 VIDEO_FB_ADRS framebuffer address
977 VIDEO_KBD_INIT_FCT keyboard int fct
978 (i.e. i8042_kbd_init())
979 VIDEO_TSTC_FCT test char fct
981 VIDEO_GETC_FCT get char fct
983 CONFIG_CONSOLE_CURSOR cursor drawing on/off
984 (requires blink timer
986 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
987 CONFIG_CONSOLE_TIME display time/date info in
989 (requires CONFIG_CMD_DATE)
990 CONFIG_VIDEO_LOGO display Linux logo in
992 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
993 linux_logo.h for logo.
994 Requires CONFIG_VIDEO_LOGO
995 CONFIG_CONSOLE_EXTRA_INFO
996 additional board info beside
999 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1000 a limited number of ANSI escape sequences (cursor control,
1001 erase functions and limited graphics rendition control).
1003 When CONFIG_CFB_CONSOLE is defined, video console is
1004 default i/o. Serial console can be forced with
1005 environment 'console=serial'.
1007 When CONFIG_SILENT_CONSOLE is defined, all console
1008 messages (by U-Boot and Linux!) can be silenced with
1009 the "silent" environment variable. See
1010 doc/README.silent for more information.
1012 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1014 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1018 CONFIG_BAUDRATE - in bps
1019 Select one of the baudrates listed in
1020 CONFIG_SYS_BAUDRATE_TABLE, see below.
1021 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1023 - Console Rx buffer length
1024 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1025 the maximum receive buffer length for the SMC.
1026 This option is actual only for 82xx and 8xx possible.
1027 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1028 must be defined, to setup the maximum idle timeout for
1031 - Pre-Console Buffer:
1032 Prior to the console being initialised (i.e. serial UART
1033 initialised etc) all console output is silently discarded.
1034 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1035 buffer any console messages prior to the console being
1036 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1037 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1038 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1039 bytes are output before the console is initialised, the
1040 earlier bytes are discarded.
1042 'Sane' compilers will generate smaller code if
1043 CONFIG_PRE_CON_BUF_SZ is a power of 2
1045 - Safe printf() functions
1046 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1047 the printf() functions. These are defined in
1048 include/vsprintf.h and include snprintf(), vsnprintf() and
1049 so on. Code size increase is approximately 300-500 bytes.
1050 If this option is not given then these functions will
1051 silently discard their buffer size argument - this means
1052 you are not getting any overflow checking in this case.
1054 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1055 Delay before automatically booting the default image;
1056 set to -1 to disable autoboot.
1057 set to -2 to autoboot with no delay and not check for abort
1058 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1060 See doc/README.autoboot for these options that
1061 work with CONFIG_BOOTDELAY. None are required.
1062 CONFIG_BOOT_RETRY_TIME
1063 CONFIG_BOOT_RETRY_MIN
1064 CONFIG_AUTOBOOT_KEYED
1065 CONFIG_AUTOBOOT_PROMPT
1066 CONFIG_AUTOBOOT_DELAY_STR
1067 CONFIG_AUTOBOOT_STOP_STR
1068 CONFIG_AUTOBOOT_DELAY_STR2
1069 CONFIG_AUTOBOOT_STOP_STR2
1070 CONFIG_ZERO_BOOTDELAY_CHECK
1071 CONFIG_RESET_TO_RETRY
1075 Only needed when CONFIG_BOOTDELAY is enabled;
1076 define a command string that is automatically executed
1077 when no character is read on the console interface
1078 within "Boot Delay" after reset.
1081 This can be used to pass arguments to the bootm
1082 command. The value of CONFIG_BOOTARGS goes into the
1083 environment value "bootargs".
1085 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1086 The value of these goes into the environment as
1087 "ramboot" and "nfsboot" respectively, and can be used
1088 as a convenience, when switching between booting from
1092 CONFIG_BOOTCOUNT_LIMIT
1093 Implements a mechanism for detecting a repeating reboot
1095 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1097 CONFIG_BOOTCOUNT_ENV
1098 If no softreset save registers are found on the hardware
1099 "bootcount" is stored in the environment. To prevent a
1100 saveenv on all reboots, the environment variable
1101 "upgrade_available" is used. If "upgrade_available" is
1102 0, "bootcount" is always 0, if "upgrade_available" is
1103 1 "bootcount" is incremented in the environment.
1104 So the Userspace Applikation must set the "upgrade_available"
1105 and "bootcount" variable to 0, if a boot was successfully.
1107 - Pre-Boot Commands:
1110 When this option is #defined, the existence of the
1111 environment variable "preboot" will be checked
1112 immediately before starting the CONFIG_BOOTDELAY
1113 countdown and/or running the auto-boot command resp.
1114 entering interactive mode.
1116 This feature is especially useful when "preboot" is
1117 automatically generated or modified. For an example
1118 see the LWMON board specific code: here "preboot" is
1119 modified when the user holds down a certain
1120 combination of keys on the (special) keyboard when
1123 - Serial Download Echo Mode:
1125 If defined to 1, all characters received during a
1126 serial download (using the "loads" command) are
1127 echoed back. This might be needed by some terminal
1128 emulations (like "cu"), but may as well just take
1129 time on others. This setting #define's the initial
1130 value of the "loads_echo" environment variable.
1132 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1133 CONFIG_KGDB_BAUDRATE
1134 Select one of the baudrates listed in
1135 CONFIG_SYS_BAUDRATE_TABLE, see below.
1137 - Monitor Functions:
1138 Monitor commands can be included or excluded
1139 from the build by using the #include files
1140 <config_cmd_all.h> and #undef'ing unwanted
1141 commands, or using <config_cmd_default.h>
1142 and augmenting with additional #define's
1143 for wanted commands.
1145 The default command configuration includes all commands
1146 except those marked below with a "*".
1148 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1149 CONFIG_CMD_ASKENV * ask for env variable
1150 CONFIG_CMD_BDI bdinfo
1151 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1152 CONFIG_CMD_BMP * BMP support
1153 CONFIG_CMD_BSP * Board specific commands
1154 CONFIG_CMD_BOOTD bootd
1155 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1156 CONFIG_CMD_CACHE * icache, dcache
1157 CONFIG_CMD_CLK * clock command support
1158 CONFIG_CMD_CONSOLE coninfo
1159 CONFIG_CMD_CRC32 * crc32
1160 CONFIG_CMD_DATE * support for RTC, date/time...
1161 CONFIG_CMD_DHCP * DHCP support
1162 CONFIG_CMD_DIAG * Diagnostics
1163 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1164 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1165 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1166 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1167 CONFIG_CMD_DTT * Digital Therm and Thermostat
1168 CONFIG_CMD_ECHO echo arguments
1169 CONFIG_CMD_EDITENV edit env variable
1170 CONFIG_CMD_EEPROM * EEPROM read/write support
1171 CONFIG_CMD_ELF * bootelf, bootvx
1172 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1173 CONFIG_CMD_ENV_FLAGS * display details about env flags
1174 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1175 CONFIG_CMD_EXPORTENV * export the environment
1176 CONFIG_CMD_EXT2 * ext2 command support
1177 CONFIG_CMD_EXT4 * ext4 command support
1178 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1179 that work for multiple fs types
1180 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1181 CONFIG_CMD_SAVEENV saveenv
1182 CONFIG_CMD_FDC * Floppy Disk Support
1183 CONFIG_CMD_FAT * FAT command support
1184 CONFIG_CMD_FLASH flinfo, erase, protect
1185 CONFIG_CMD_FPGA FPGA device initialization support
1186 CONFIG_CMD_FUSE * Device fuse support
1187 CONFIG_CMD_GETTIME * Get time since boot
1188 CONFIG_CMD_GO * the 'go' command (exec code)
1189 CONFIG_CMD_GREPENV * search environment
1190 CONFIG_CMD_HASH * calculate hash / digest
1191 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1192 CONFIG_CMD_I2C * I2C serial bus support
1193 CONFIG_CMD_IDE * IDE harddisk support
1194 CONFIG_CMD_IMI iminfo
1195 CONFIG_CMD_IMLS List all images found in NOR flash
1196 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1197 CONFIG_CMD_IMMAP * IMMR dump support
1198 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1199 CONFIG_CMD_IMPORTENV * import an environment
1200 CONFIG_CMD_INI * import data from an ini file into the env
1201 CONFIG_CMD_IRQ * irqinfo
1202 CONFIG_CMD_ITEST Integer/string test of 2 values
1203 CONFIG_CMD_JFFS2 * JFFS2 Support
1204 CONFIG_CMD_KGDB * kgdb
1205 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1206 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1208 CONFIG_CMD_LOADB loadb
1209 CONFIG_CMD_LOADS loads
1210 CONFIG_CMD_MD5SUM * print md5 message digest
1211 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1212 CONFIG_CMD_MEMINFO * Display detailed memory information
1213 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1215 CONFIG_CMD_MEMTEST * mtest
1216 CONFIG_CMD_MISC Misc functions like sleep etc
1217 CONFIG_CMD_MMC * MMC memory mapped support
1218 CONFIG_CMD_MII * MII utility commands
1219 CONFIG_CMD_MTDPARTS * MTD partition support
1220 CONFIG_CMD_NAND * NAND support
1221 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1222 CONFIG_CMD_NFS NFS support
1223 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1224 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1225 CONFIG_CMD_PCI * pciinfo
1226 CONFIG_CMD_PCMCIA * PCMCIA support
1227 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1229 CONFIG_CMD_PORTIO * Port I/O
1230 CONFIG_CMD_READ * Read raw data from partition
1231 CONFIG_CMD_REGINFO * Register dump
1232 CONFIG_CMD_RUN run command in env variable
1233 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1234 CONFIG_CMD_SAVES * save S record dump
1235 CONFIG_CMD_SCSI * SCSI Support
1236 CONFIG_CMD_SDRAM * print SDRAM configuration information
1237 (requires CONFIG_CMD_I2C)
1238 CONFIG_CMD_SETGETDCR Support for DCR Register access
1240 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1241 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1242 (requires CONFIG_CMD_MEMORY)
1243 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1244 CONFIG_CMD_SOURCE "source" command Support
1245 CONFIG_CMD_SPI * SPI serial bus support
1246 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1247 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1248 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1249 CONFIG_CMD_TIMER * access to the system tick timer
1250 CONFIG_CMD_USB * USB support
1251 CONFIG_CMD_CDP * Cisco Discover Protocol support
1252 CONFIG_CMD_MFSL * Microblaze FSL support
1253 CONFIG_CMD_XIMG Load part of Multi Image
1254 CONFIG_CMD_UUID * Generate random UUID or GUID string
1256 EXAMPLE: If you want all functions except of network
1257 support you can write:
1259 #include "config_cmd_all.h"
1260 #undef CONFIG_CMD_NET
1263 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1265 Note: Don't enable the "icache" and "dcache" commands
1266 (configuration option CONFIG_CMD_CACHE) unless you know
1267 what you (and your U-Boot users) are doing. Data
1268 cache cannot be enabled on systems like the 8xx or
1269 8260 (where accesses to the IMMR region must be
1270 uncached), and it cannot be disabled on all other
1271 systems where we (mis-) use the data cache to hold an
1272 initial stack and some data.
1275 XXX - this list needs to get updated!
1277 - Regular expression support:
1279 If this variable is defined, U-Boot is linked against
1280 the SLRE (Super Light Regular Expression) library,
1281 which adds regex support to some commands, as for
1282 example "env grep" and "setexpr".
1286 If this variable is defined, U-Boot will use a device tree
1287 to configure its devices, instead of relying on statically
1288 compiled #defines in the board file. This option is
1289 experimental and only available on a few boards. The device
1290 tree is available in the global data as gd->fdt_blob.
1292 U-Boot needs to get its device tree from somewhere. This can
1293 be done using one of the two options below:
1296 If this variable is defined, U-Boot will embed a device tree
1297 binary in its image. This device tree file should be in the
1298 board directory and called <soc>-<board>.dts. The binary file
1299 is then picked up in board_init_f() and made available through
1300 the global data structure as gd->blob.
1303 If this variable is defined, U-Boot will build a device tree
1304 binary. It will be called u-boot.dtb. Architecture-specific
1305 code will locate it at run-time. Generally this works by:
1307 cat u-boot.bin u-boot.dtb >image.bin
1309 and in fact, U-Boot does this for you, creating a file called
1310 u-boot-dtb.bin which is useful in the common case. You can
1311 still use the individual files if you need something more
1316 If this variable is defined, it enables watchdog
1317 support for the SoC. There must be support in the SoC
1318 specific code for a watchdog. For the 8xx and 8260
1319 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1320 register. When supported for a specific SoC is
1321 available, then no further board specific code should
1322 be needed to use it.
1325 When using a watchdog circuitry external to the used
1326 SoC, then define this variable and provide board
1327 specific code for the "hw_watchdog_reset" function.
1329 CONFIG_AT91_HW_WDT_TIMEOUT
1330 specify the timeout in seconds. default 2 seconds.
1333 CONFIG_VERSION_VARIABLE
1334 If this variable is defined, an environment variable
1335 named "ver" is created by U-Boot showing the U-Boot
1336 version as printed by the "version" command.
1337 Any change to this variable will be reverted at the
1342 When CONFIG_CMD_DATE is selected, the type of the RTC
1343 has to be selected, too. Define exactly one of the
1346 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1347 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1348 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1349 CONFIG_RTC_MC146818 - use MC146818 RTC
1350 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1351 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1352 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1353 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1354 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1355 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1356 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1357 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1358 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1361 Note that if the RTC uses I2C, then the I2C interface
1362 must also be configured. See I2C Support, below.
1365 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1367 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1368 chip-ngpio pairs that tell the PCA953X driver the number of
1369 pins supported by a particular chip.
1371 Note that if the GPIO device uses I2C, then the I2C interface
1372 must also be configured. See I2C Support, below.
1375 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1376 accesses and can checksum them or write a list of them out
1377 to memory. See the 'iotrace' command for details. This is
1378 useful for testing device drivers since it can confirm that
1379 the driver behaves the same way before and after a code
1380 change. Currently this is supported on sandbox and arm. To
1381 add support for your architecture, add '#include <iotrace.h>'
1382 to the bottom of arch/<arch>/include/asm/io.h and test.
1384 Example output from the 'iotrace stats' command is below.
1385 Note that if the trace buffer is exhausted, the checksum will
1386 still continue to operate.
1389 Start: 10000000 (buffer start address)
1390 Size: 00010000 (buffer size)
1391 Offset: 00000120 (current buffer offset)
1392 Output: 10000120 (start + offset)
1393 Count: 00000018 (number of trace records)
1394 CRC32: 9526fb66 (CRC32 of all trace records)
1396 - Timestamp Support:
1398 When CONFIG_TIMESTAMP is selected, the timestamp
1399 (date and time) of an image is printed by image
1400 commands like bootm or iminfo. This option is
1401 automatically enabled when you select CONFIG_CMD_DATE .
1403 - Partition Labels (disklabels) Supported:
1404 Zero or more of the following:
1405 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1406 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1407 Intel architecture, USB sticks, etc.
1408 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1409 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1410 bootloader. Note 2TB partition limit; see
1412 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1414 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1415 CONFIG_CMD_SCSI) you must configure support for at
1416 least one non-MTD partition type as well.
1419 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1420 board configurations files but used nowhere!
1422 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1423 be performed by calling the function
1424 ide_set_reset(int reset)
1425 which has to be defined in a board specific file
1430 Set this to enable ATAPI support.
1435 Set this to enable support for disks larger than 137GB
1436 Also look at CONFIG_SYS_64BIT_LBA.
1437 Whithout these , LBA48 support uses 32bit variables and will 'only'
1438 support disks up to 2.1TB.
1440 CONFIG_SYS_64BIT_LBA:
1441 When enabled, makes the IDE subsystem use 64bit sector addresses.
1445 At the moment only there is only support for the
1446 SYM53C8XX SCSI controller; define
1447 CONFIG_SCSI_SYM53C8XX to enable it.
1449 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1450 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1451 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1452 maximum numbers of LUNs, SCSI ID's and target
1454 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1456 The environment variable 'scsidevs' is set to the number of
1457 SCSI devices found during the last scan.
1459 - NETWORK Support (PCI):
1461 Support for Intel 8254x/8257x gigabit chips.
1464 Utility code for direct access to the SPI bus on Intel 8257x.
1465 This does not do anything useful unless you set at least one
1466 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1468 CONFIG_E1000_SPI_GENERIC
1469 Allow generic access to the SPI bus on the Intel 8257x, for
1470 example with the "sspi" command.
1473 Management command for E1000 devices. When used on devices
1474 with SPI support you can reprogram the EEPROM from U-Boot.
1476 CONFIG_E1000_FALLBACK_MAC
1477 default MAC for empty EEPROM after production.
1480 Support for Intel 82557/82559/82559ER chips.
1481 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1482 write routine for first time initialisation.
1485 Support for Digital 2114x chips.
1486 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1487 modem chip initialisation (KS8761/QS6611).
1490 Support for National dp83815 chips.
1493 Support for National dp8382[01] gigabit chips.
1495 - NETWORK Support (other):
1497 CONFIG_DRIVER_AT91EMAC
1498 Support for AT91RM9200 EMAC.
1501 Define this to use reduced MII inteface
1503 CONFIG_DRIVER_AT91EMAC_QUIET
1504 If this defined, the driver is quiet.
1505 The driver doen't show link status messages.
1507 CONFIG_CALXEDA_XGMAC
1508 Support for the Calxeda XGMAC device
1511 Support for SMSC's LAN91C96 chips.
1513 CONFIG_LAN91C96_BASE
1514 Define this to hold the physical address
1515 of the LAN91C96's I/O space
1517 CONFIG_LAN91C96_USE_32_BIT
1518 Define this to enable 32 bit addressing
1521 Support for SMSC's LAN91C111 chip
1523 CONFIG_SMC91111_BASE
1524 Define this to hold the physical address
1525 of the device (I/O space)
1527 CONFIG_SMC_USE_32_BIT
1528 Define this if data bus is 32 bits
1530 CONFIG_SMC_USE_IOFUNCS
1531 Define this to use i/o functions instead of macros
1532 (some hardware wont work with macros)
1534 CONFIG_DRIVER_TI_EMAC
1535 Support for davinci emac
1537 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1538 Define this if you have more then 3 PHYs.
1541 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1543 CONFIG_FTGMAC100_EGIGA
1544 Define this to use GE link update with gigabit PHY.
1545 Define this if FTGMAC100 is connected to gigabit PHY.
1546 If your system has 10/100 PHY only, it might not occur
1547 wrong behavior. Because PHY usually return timeout or
1548 useless data when polling gigabit status and gigabit
1549 control registers. This behavior won't affect the
1550 correctnessof 10/100 link speed update.
1553 Support for SMSC's LAN911x and LAN921x chips
1556 Define this to hold the physical address
1557 of the device (I/O space)
1559 CONFIG_SMC911X_32_BIT
1560 Define this if data bus is 32 bits
1562 CONFIG_SMC911X_16_BIT
1563 Define this if data bus is 16 bits. If your processor
1564 automatically converts one 32 bit word to two 16 bit
1565 words you may also try CONFIG_SMC911X_32_BIT.
1568 Support for Renesas on-chip Ethernet controller
1570 CONFIG_SH_ETHER_USE_PORT
1571 Define the number of ports to be used
1573 CONFIG_SH_ETHER_PHY_ADDR
1574 Define the ETH PHY's address
1576 CONFIG_SH_ETHER_CACHE_WRITEBACK
1577 If this option is set, the driver enables cache flush.
1581 Support for PWM modul on the imx6.
1585 Support TPM devices.
1588 Support for i2c bus TPM devices. Only one device
1589 per system is supported at this time.
1591 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1592 Define the the i2c bus number for the TPM device
1594 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1595 Define the TPM's address on the i2c bus
1597 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1598 Define the burst count bytes upper limit
1600 CONFIG_TPM_ATMEL_TWI
1601 Support for Atmel TWI TPM device. Requires I2C support.
1604 Support for generic parallel port TPM devices. Only one device
1605 per system is supported at this time.
1607 CONFIG_TPM_TIS_BASE_ADDRESS
1608 Base address where the generic TPM device is mapped
1609 to. Contemporary x86 systems usually map it at
1613 Add tpm monitor functions.
1614 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1615 provides monitor access to authorized functions.
1618 Define this to enable the TPM support library which provides
1619 functional interfaces to some TPM commands.
1620 Requires support for a TPM device.
1622 CONFIG_TPM_AUTH_SESSIONS
1623 Define this to enable authorized functions in the TPM library.
1624 Requires CONFIG_TPM and CONFIG_SHA1.
1627 At the moment only the UHCI host controller is
1628 supported (PIP405, MIP405, MPC5200); define
1629 CONFIG_USB_UHCI to enable it.
1630 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1631 and define CONFIG_USB_STORAGE to enable the USB
1634 Supported are USB Keyboards and USB Floppy drives
1636 MPC5200 USB requires additional defines:
1638 for 528 MHz Clock: 0x0001bbbb
1642 for differential drivers: 0x00001000
1643 for single ended drivers: 0x00005000
1644 for differential drivers on PSC3: 0x00000100
1645 for single ended drivers on PSC3: 0x00004100
1646 CONFIG_SYS_USB_EVENT_POLL
1647 May be defined to allow interrupt polling
1648 instead of using asynchronous interrupts
1650 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1651 txfilltuning field in the EHCI controller on reset.
1653 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1654 HW module registers.
1657 Define the below if you wish to use the USB console.
1658 Once firmware is rebuilt from a serial console issue the
1659 command "setenv stdin usbtty; setenv stdout usbtty" and
1660 attach your USB cable. The Unix command "dmesg" should print
1661 it has found a new device. The environment variable usbtty
1662 can be set to gserial or cdc_acm to enable your device to
1663 appear to a USB host as a Linux gserial device or a
1664 Common Device Class Abstract Control Model serial device.
1665 If you select usbtty = gserial you should be able to enumerate
1667 # modprobe usbserial vendor=0xVendorID product=0xProductID
1668 else if using cdc_acm, simply setting the environment
1669 variable usbtty to be cdc_acm should suffice. The following
1670 might be defined in YourBoardName.h
1673 Define this to build a UDC device
1676 Define this to have a tty type of device available to
1677 talk to the UDC device
1680 Define this to enable the high speed support for usb
1681 device and usbtty. If this feature is enabled, a routine
1682 int is_usbd_high_speed(void)
1683 also needs to be defined by the driver to dynamically poll
1684 whether the enumeration has succeded at high speed or full
1687 CONFIG_SYS_CONSOLE_IS_IN_ENV
1688 Define this if you want stdin, stdout &/or stderr to
1692 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1693 Derive USB clock from external clock "blah"
1694 - CONFIG_SYS_USB_EXTC_CLK 0x02
1696 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1697 Derive USB clock from brgclk
1698 - CONFIG_SYS_USB_BRG_CLK 0x04
1700 If you have a USB-IF assigned VendorID then you may wish to
1701 define your own vendor specific values either in BoardName.h
1702 or directly in usbd_vendor_info.h. If you don't define
1703 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1704 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1705 should pretend to be a Linux device to it's target host.
1707 CONFIG_USBD_MANUFACTURER
1708 Define this string as the name of your company for
1709 - CONFIG_USBD_MANUFACTURER "my company"
1711 CONFIG_USBD_PRODUCT_NAME
1712 Define this string as the name of your product
1713 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1715 CONFIG_USBD_VENDORID
1716 Define this as your assigned Vendor ID from the USB
1717 Implementors Forum. This *must* be a genuine Vendor ID
1718 to avoid polluting the USB namespace.
1719 - CONFIG_USBD_VENDORID 0xFFFF
1721 CONFIG_USBD_PRODUCTID
1722 Define this as the unique Product ID
1724 - CONFIG_USBD_PRODUCTID 0xFFFF
1726 - ULPI Layer Support:
1727 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1728 the generic ULPI layer. The generic layer accesses the ULPI PHY
1729 via the platform viewport, so you need both the genric layer and
1730 the viewport enabled. Currently only Chipidea/ARC based
1731 viewport is supported.
1732 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1733 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1734 If your ULPI phy needs a different reference clock than the
1735 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1736 the appropriate value in Hz.
1739 The MMC controller on the Intel PXA is supported. To
1740 enable this define CONFIG_MMC. The MMC can be
1741 accessed from the boot prompt by mapping the device
1742 to physical memory similar to flash. Command line is
1743 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1744 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1747 Support for Renesas on-chip MMCIF controller
1749 CONFIG_SH_MMCIF_ADDR
1750 Define the base address of MMCIF registers
1753 Define the clock frequency for MMCIF
1756 Enable the generic MMC driver
1758 CONFIG_SUPPORT_EMMC_BOOT
1759 Enable some additional features of the eMMC boot partitions.
1761 CONFIG_SUPPORT_EMMC_RPMB
1762 Enable the commands for reading, writing and programming the
1763 key for the Replay Protection Memory Block partition in eMMC.
1765 - USB Device Firmware Update (DFU) class support:
1767 This enables the USB portion of the DFU USB class
1770 This enables the command "dfu" which is used to have
1771 U-Boot create a DFU class device via USB. This command
1772 requires that the "dfu_alt_info" environment variable be
1773 set and define the alt settings to expose to the host.
1776 This enables support for exposing (e)MMC devices via DFU.
1779 This enables support for exposing NAND devices via DFU.
1782 This enables support for exposing RAM via DFU.
1783 Note: DFU spec refer to non-volatile memory usage, but
1784 allow usages beyond the scope of spec - here RAM usage,
1785 one that would help mostly the developer.
1787 CONFIG_SYS_DFU_DATA_BUF_SIZE
1788 Dfu transfer uses a buffer before writing data to the
1789 raw storage device. Make the size (in bytes) of this buffer
1790 configurable. The size of this buffer is also configurable
1791 through the "dfu_bufsiz" environment variable.
1793 CONFIG_SYS_DFU_MAX_FILE_SIZE
1794 When updating files rather than the raw storage device,
1795 we use a static buffer to copy the file into and then write
1796 the buffer once we've been given the whole file. Define
1797 this to the maximum filesize (in bytes) for the buffer.
1798 Default is 4 MiB if undefined.
1800 DFU_DEFAULT_POLL_TIMEOUT
1801 Poll timeout [ms], is the timeout a device can send to the
1802 host. The host must wait for this timeout before sending
1803 a subsequent DFU_GET_STATUS request to the device.
1805 DFU_MANIFEST_POLL_TIMEOUT
1806 Poll timeout [ms], which the device sends to the host when
1807 entering dfuMANIFEST state. Host waits this timeout, before
1808 sending again an USB request to the device.
1810 - USB Device Android Fastboot support:
1812 This enables the command "fastboot" which enables the Android
1813 fastboot mode for the platform's USB device. Fastboot is a USB
1814 protocol for downloading images, flashing and device control
1815 used on Android devices.
1816 See doc/README.android-fastboot for more information.
1818 CONFIG_ANDROID_BOOT_IMAGE
1819 This enables support for booting images which use the Android
1820 image format header.
1822 CONFIG_USB_FASTBOOT_BUF_ADDR
1823 The fastboot protocol requires a large memory buffer for
1824 downloads. Define this to the starting RAM address to use for
1827 CONFIG_USB_FASTBOOT_BUF_SIZE
1828 The fastboot protocol requires a large memory buffer for
1829 downloads. This buffer should be as large as possible for a
1830 platform. Define this to the size available RAM for fastboot.
1832 CONFIG_FASTBOOT_FLASH
1833 The fastboot protocol includes a "flash" command for writing
1834 the downloaded image to a non-volatile storage device. Define
1835 this to enable the "fastboot flash" command.
1837 CONFIG_FASTBOOT_FLASH_MMC_DEV
1838 The fastboot "flash" command requires additional information
1839 regarding the non-volatile storage device. Define this to
1840 the eMMC device that fastboot should use to store the image.
1842 CONFIG_FASTBOOT_GPT_NAME
1843 The fastboot "flash" command supports writing the downloaded
1844 image to the Protective MBR and the Primary GUID Partition
1845 Table. (Additionally, this downloaded image is post-processed
1846 to generate and write the Backup GUID Partition Table.)
1847 This occurs when the specified "partition name" on the
1848 "fastboot flash" command line matches this value.
1849 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1851 - Journaling Flash filesystem support:
1852 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1853 CONFIG_JFFS2_NAND_DEV
1854 Define these for a default partition on a NAND device
1856 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1857 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1858 Define these for a default partition on a NOR device
1860 CONFIG_SYS_JFFS_CUSTOM_PART
1861 Define this to create an own partition. You have to provide a
1862 function struct part_info* jffs2_part_info(int part_num)
1864 If you define only one JFFS2 partition you may also want to
1865 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1866 to disable the command chpart. This is the default when you
1867 have not defined a custom partition
1869 - FAT(File Allocation Table) filesystem write function support:
1872 Define this to enable support for saving memory data as a
1873 file in FAT formatted partition.
1875 This will also enable the command "fatwrite" enabling the
1876 user to write files to FAT.
1878 CBFS (Coreboot Filesystem) support
1881 Define this to enable support for reading from a Coreboot
1882 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1885 - FAT(File Allocation Table) filesystem cluster size:
1886 CONFIG_FS_FAT_MAX_CLUSTSIZE
1888 Define the max cluster size for fat operations else
1889 a default value of 65536 will be defined.
1894 Define this to enable standard (PC-Style) keyboard
1898 Standard PC keyboard driver with US (is default) and
1899 GERMAN key layout (switch via environment 'keymap=de') support.
1900 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1901 for cfb_console. Supports cursor blinking.
1904 Enables a Chrome OS keyboard using the CROS_EC interface.
1905 This uses CROS_EC to communicate with a second microcontroller
1906 which provides key scans on request.
1911 Define this to enable video support (for output to
1914 CONFIG_VIDEO_CT69000
1916 Enable Chips & Technologies 69000 Video chip
1918 CONFIG_VIDEO_SMI_LYNXEM
1919 Enable Silicon Motion SMI 712/710/810 Video chip. The
1920 video output is selected via environment 'videoout'
1921 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1924 For the CT69000 and SMI_LYNXEM drivers, videomode is
1925 selected via environment 'videomode'. Two different ways
1927 - "videomode=num" 'num' is a standard LiLo mode numbers.
1928 Following standard modes are supported (* is default):
1930 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1931 -------------+---------------------------------------------
1932 8 bits | 0x301* 0x303 0x305 0x161 0x307
1933 15 bits | 0x310 0x313 0x316 0x162 0x319
1934 16 bits | 0x311 0x314 0x317 0x163 0x31A
1935 24 bits | 0x312 0x315 0x318 ? 0x31B
1936 -------------+---------------------------------------------
1937 (i.e. setenv videomode 317; saveenv; reset;)
1939 - "videomode=bootargs" all the video parameters are parsed
1940 from the bootargs. (See drivers/video/videomodes.c)
1943 CONFIG_VIDEO_SED13806
1944 Enable Epson SED13806 driver. This driver supports 8bpp
1945 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1946 or CONFIG_VIDEO_SED13806_16BPP
1949 Enable the Freescale DIU video driver. Reference boards for
1950 SOCs that have a DIU should define this macro to enable DIU
1951 support, and should also define these other macros:
1957 CONFIG_VIDEO_SW_CURSOR
1958 CONFIG_VGA_AS_SINGLE_DEVICE
1960 CONFIG_VIDEO_BMP_LOGO
1962 The DIU driver will look for the 'video-mode' environment
1963 variable, and if defined, enable the DIU as a console during
1964 boot. See the documentation file README.video for a
1965 description of this variable.
1969 Enable the VGA video / BIOS for x86. The alternative if you
1970 are using coreboot is to use the coreboot frame buffer
1977 Define this to enable a custom keyboard support.
1978 This simply calls drv_keyboard_init() which must be
1979 defined in your board-specific files.
1980 The only board using this so far is RBC823.
1982 - LCD Support: CONFIG_LCD
1984 Define this to enable LCD support (for output to LCD
1985 display); also select one of the supported displays
1986 by defining one of these:
1990 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1992 CONFIG_NEC_NL6448AC33:
1994 NEC NL6448AC33-18. Active, color, single scan.
1996 CONFIG_NEC_NL6448BC20
1998 NEC NL6448BC20-08. 6.5", 640x480.
1999 Active, color, single scan.
2001 CONFIG_NEC_NL6448BC33_54
2003 NEC NL6448BC33-54. 10.4", 640x480.
2004 Active, color, single scan.
2008 Sharp 320x240. Active, color, single scan.
2009 It isn't 16x9, and I am not sure what it is.
2011 CONFIG_SHARP_LQ64D341
2013 Sharp LQ64D341 display, 640x480.
2014 Active, color, single scan.
2018 HLD1045 display, 640x480.
2019 Active, color, single scan.
2023 Optrex CBL50840-2 NF-FW 99 22 M5
2025 Hitachi LMG6912RPFC-00T
2029 320x240. Black & white.
2031 Normally display is black on white background; define
2032 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2034 CONFIG_LCD_ALIGNMENT
2036 Normally the LCD is page-aligned (typically 4KB). If this is
2037 defined then the LCD will be aligned to this value instead.
2038 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2039 here, since it is cheaper to change data cache settings on
2040 a per-section basis.
2042 CONFIG_CONSOLE_SCROLL_LINES
2044 When the console need to be scrolled, this is the number of
2045 lines to scroll by. It defaults to 1. Increasing this makes
2046 the console jump but can help speed up operation when scrolling
2051 Support drawing of RLE8-compressed bitmaps on the LCD.
2055 Enables an 'i2c edid' command which can read EDID
2056 information over I2C from an attached LCD display.
2058 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2060 If this option is set, the environment is checked for
2061 a variable "splashimage". If found, the usual display
2062 of logo, copyright and system information on the LCD
2063 is suppressed and the BMP image at the address
2064 specified in "splashimage" is loaded instead. The
2065 console is redirected to the "nulldev", too. This
2066 allows for a "silent" boot where a splash screen is
2067 loaded very quickly after power-on.
2069 CONFIG_SPLASHIMAGE_GUARD
2071 If this option is set, then U-Boot will prevent the environment
2072 variable "splashimage" from being set to a problematic address
2073 (see README.displaying-bmps).
2074 This option is useful for targets where, due to alignment
2075 restrictions, an improperly aligned BMP image will cause a data
2076 abort. If you think you will not have problems with unaligned
2077 accesses (for example because your toolchain prevents them)
2078 there is no need to set this option.
2080 CONFIG_SPLASH_SCREEN_ALIGN
2082 If this option is set the splash image can be freely positioned
2083 on the screen. Environment variable "splashpos" specifies the
2084 position as "x,y". If a positive number is given it is used as
2085 number of pixel from left/top. If a negative number is given it
2086 is used as number of pixel from right/bottom. You can also
2087 specify 'm' for centering the image.
2090 setenv splashpos m,m
2091 => image at center of screen
2093 setenv splashpos 30,20
2094 => image at x = 30 and y = 20
2096 setenv splashpos -10,m
2097 => vertically centered image
2098 at x = dspWidth - bmpWidth - 9
2100 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2102 If this option is set, additionally to standard BMP
2103 images, gzipped BMP images can be displayed via the
2104 splashscreen support or the bmp command.
2106 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2108 If this option is set, 8-bit RLE compressed BMP images
2109 can be displayed via the splashscreen support or the
2112 - Do compressing for memory range:
2115 If this option is set, it would use zlib deflate method
2116 to compress the specified memory at its best effort.
2118 - Compression support:
2121 Enabled by default to support gzip compressed images.
2125 If this option is set, support for bzip2 compressed
2126 images is included. If not, only uncompressed and gzip
2127 compressed images are supported.
2129 NOTE: the bzip2 algorithm requires a lot of RAM, so
2130 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2135 If this option is set, support for lzma compressed
2138 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2139 requires an amount of dynamic memory that is given by the
2142 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2144 Where lc and lp stand for, respectively, Literal context bits
2145 and Literal pos bits.
2147 This value is upper-bounded by 14MB in the worst case. Anyway,
2148 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2149 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2150 a very small buffer.
2152 Use the lzmainfo tool to determinate the lc and lp values and
2153 then calculate the amount of needed dynamic memory (ensuring
2154 the appropriate CONFIG_SYS_MALLOC_LEN value).
2158 If this option is set, support for LZO compressed images
2164 The address of PHY on MII bus.
2166 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2168 The clock frequency of the MII bus
2172 If this option is set, support for speed/duplex
2173 detection of gigabit PHY is included.
2175 CONFIG_PHY_RESET_DELAY
2177 Some PHY like Intel LXT971A need extra delay after
2178 reset before any MII register access is possible.
2179 For such PHY, set this option to the usec delay
2180 required. (minimum 300usec for LXT971A)
2182 CONFIG_PHY_CMD_DELAY (ppc4xx)
2184 Some PHY like Intel LXT971A need extra delay after
2185 command issued before MII status register can be read
2195 Define a default value for Ethernet address to use
2196 for the respective Ethernet interface, in case this
2197 is not determined automatically.
2202 Define a default value for the IP address to use for
2203 the default Ethernet interface, in case this is not
2204 determined through e.g. bootp.
2205 (Environment variable "ipaddr")
2207 - Server IP address:
2210 Defines a default value for the IP address of a TFTP
2211 server to contact when using the "tftboot" command.
2212 (Environment variable "serverip")
2214 CONFIG_KEEP_SERVERADDR
2216 Keeps the server's MAC address, in the env 'serveraddr'
2217 for passing to bootargs (like Linux's netconsole option)
2219 - Gateway IP address:
2222 Defines a default value for the IP address of the
2223 default router where packets to other networks are
2225 (Environment variable "gatewayip")
2230 Defines a default value for the subnet mask (or
2231 routing prefix) which is used to determine if an IP
2232 address belongs to the local subnet or needs to be
2233 forwarded through a router.
2234 (Environment variable "netmask")
2236 - Multicast TFTP Mode:
2239 Defines whether you want to support multicast TFTP as per
2240 rfc-2090; for example to work with atftp. Lets lots of targets
2241 tftp down the same boot image concurrently. Note: the Ethernet
2242 driver in use must provide a function: mcast() to join/leave a
2245 - BOOTP Recovery Mode:
2246 CONFIG_BOOTP_RANDOM_DELAY
2248 If you have many targets in a network that try to
2249 boot using BOOTP, you may want to avoid that all
2250 systems send out BOOTP requests at precisely the same
2251 moment (which would happen for instance at recovery
2252 from a power failure, when all systems will try to
2253 boot, thus flooding the BOOTP server. Defining
2254 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2255 inserted before sending out BOOTP requests. The
2256 following delays are inserted then:
2258 1st BOOTP request: delay 0 ... 1 sec
2259 2nd BOOTP request: delay 0 ... 2 sec
2260 3rd BOOTP request: delay 0 ... 4 sec
2262 BOOTP requests: delay 0 ... 8 sec
2264 CONFIG_BOOTP_ID_CACHE_SIZE
2266 BOOTP packets are uniquely identified using a 32-bit ID. The
2267 server will copy the ID from client requests to responses and
2268 U-Boot will use this to determine if it is the destination of
2269 an incoming response. Some servers will check that addresses
2270 aren't in use before handing them out (usually using an ARP
2271 ping) and therefore take up to a few hundred milliseconds to
2272 respond. Network congestion may also influence the time it
2273 takes for a response to make it back to the client. If that
2274 time is too long, U-Boot will retransmit requests. In order
2275 to allow earlier responses to still be accepted after these
2276 retransmissions, U-Boot's BOOTP client keeps a small cache of
2277 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2278 cache. The default is to keep IDs for up to four outstanding
2279 requests. Increasing this will allow U-Boot to accept offers
2280 from a BOOTP client in networks with unusually high latency.
2282 - DHCP Advanced Options:
2283 You can fine tune the DHCP functionality by defining
2284 CONFIG_BOOTP_* symbols:
2286 CONFIG_BOOTP_SUBNETMASK
2287 CONFIG_BOOTP_GATEWAY
2288 CONFIG_BOOTP_HOSTNAME
2289 CONFIG_BOOTP_NISDOMAIN
2290 CONFIG_BOOTP_BOOTPATH
2291 CONFIG_BOOTP_BOOTFILESIZE
2294 CONFIG_BOOTP_SEND_HOSTNAME
2295 CONFIG_BOOTP_NTPSERVER
2296 CONFIG_BOOTP_TIMEOFFSET
2297 CONFIG_BOOTP_VENDOREX
2298 CONFIG_BOOTP_MAY_FAIL
2300 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2301 environment variable, not the BOOTP server.
2303 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2304 after the configured retry count, the call will fail
2305 instead of starting over. This can be used to fail over
2306 to Link-local IP address configuration if the DHCP server
2309 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2310 serverip from a DHCP server, it is possible that more
2311 than one DNS serverip is offered to the client.
2312 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2313 serverip will be stored in the additional environment
2314 variable "dnsip2". The first DNS serverip is always
2315 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2318 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2319 to do a dynamic update of a DNS server. To do this, they
2320 need the hostname of the DHCP requester.
2321 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2322 of the "hostname" environment variable is passed as
2323 option 12 to the DHCP server.
2325 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2327 A 32bit value in microseconds for a delay between
2328 receiving a "DHCP Offer" and sending the "DHCP Request".
2329 This fixes a problem with certain DHCP servers that don't
2330 respond 100% of the time to a "DHCP request". E.g. On an
2331 AT91RM9200 processor running at 180MHz, this delay needed
2332 to be *at least* 15,000 usec before a Windows Server 2003
2333 DHCP server would reply 100% of the time. I recommend at
2334 least 50,000 usec to be safe. The alternative is to hope
2335 that one of the retries will be successful but note that
2336 the DHCP timeout and retry process takes a longer than
2339 - Link-local IP address negotiation:
2340 Negotiate with other link-local clients on the local network
2341 for an address that doesn't require explicit configuration.
2342 This is especially useful if a DHCP server cannot be guaranteed
2343 to exist in all environments that the device must operate.
2345 See doc/README.link-local for more information.
2348 CONFIG_CDP_DEVICE_ID
2350 The device id used in CDP trigger frames.
2352 CONFIG_CDP_DEVICE_ID_PREFIX
2354 A two character string which is prefixed to the MAC address
2359 A printf format string which contains the ascii name of
2360 the port. Normally is set to "eth%d" which sets
2361 eth0 for the first Ethernet, eth1 for the second etc.
2363 CONFIG_CDP_CAPABILITIES
2365 A 32bit integer which indicates the device capabilities;
2366 0x00000010 for a normal host which does not forwards.
2370 An ascii string containing the version of the software.
2374 An ascii string containing the name of the platform.
2378 A 32bit integer sent on the trigger.
2380 CONFIG_CDP_POWER_CONSUMPTION
2382 A 16bit integer containing the power consumption of the
2383 device in .1 of milliwatts.
2385 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2387 A byte containing the id of the VLAN.
2389 - Status LED: CONFIG_STATUS_LED
2391 Several configurations allow to display the current
2392 status using a LED. For instance, the LED will blink
2393 fast while running U-Boot code, stop blinking as
2394 soon as a reply to a BOOTP request was received, and
2395 start blinking slow once the Linux kernel is running
2396 (supported by a status LED driver in the Linux
2397 kernel). Defining CONFIG_STATUS_LED enables this
2403 The status LED can be connected to a GPIO pin.
2404 In such cases, the gpio_led driver can be used as a
2405 status LED backend implementation. Define CONFIG_GPIO_LED
2406 to include the gpio_led driver in the U-Boot binary.
2408 CONFIG_GPIO_LED_INVERTED_TABLE
2409 Some GPIO connected LEDs may have inverted polarity in which
2410 case the GPIO high value corresponds to LED off state and
2411 GPIO low value corresponds to LED on state.
2412 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2413 with a list of GPIO LEDs that have inverted polarity.
2415 - CAN Support: CONFIG_CAN_DRIVER
2417 Defining CONFIG_CAN_DRIVER enables CAN driver support
2418 on those systems that support this (optional)
2419 feature, like the TQM8xxL modules.
2421 - I2C Support: CONFIG_SYS_I2C
2423 This enable the NEW i2c subsystem, and will allow you to use
2424 i2c commands at the u-boot command line (as long as you set
2425 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2426 based realtime clock chips or other i2c devices. See
2427 common/cmd_i2c.c for a description of the command line
2430 ported i2c driver to the new framework:
2431 - drivers/i2c/soft_i2c.c:
2432 - activate first bus with CONFIG_SYS_I2C_SOFT define
2433 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2434 for defining speed and slave address
2435 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2436 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2437 for defining speed and slave address
2438 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2439 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2440 for defining speed and slave address
2441 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2442 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2443 for defining speed and slave address
2445 - drivers/i2c/fsl_i2c.c:
2446 - activate i2c driver with CONFIG_SYS_I2C_FSL
2447 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2448 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2449 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2451 - If your board supports a second fsl i2c bus, define
2452 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2453 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2454 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2457 - drivers/i2c/tegra_i2c.c:
2458 - activate this driver with CONFIG_SYS_I2C_TEGRA
2459 - This driver adds 4 i2c buses with a fix speed from
2460 100000 and the slave addr 0!
2462 - drivers/i2c/ppc4xx_i2c.c
2463 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2464 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2465 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2467 - drivers/i2c/i2c_mxc.c
2468 - activate this driver with CONFIG_SYS_I2C_MXC
2469 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2470 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2471 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2472 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2473 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2474 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2475 If those defines are not set, default value is 100000
2476 for speed, and 0 for slave.
2478 - drivers/i2c/rcar_i2c.c:
2479 - activate this driver with CONFIG_SYS_I2C_RCAR
2480 - This driver adds 4 i2c buses
2482 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2483 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2484 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2485 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2486 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2487 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2488 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2489 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2490 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2492 - drivers/i2c/sh_i2c.c:
2493 - activate this driver with CONFIG_SYS_I2C_SH
2494 - This driver adds from 2 to 5 i2c buses
2496 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2497 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2498 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2499 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2500 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2501 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2502 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2503 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2504 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2505 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2506 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2507 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2508 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2510 - drivers/i2c/omap24xx_i2c.c
2511 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2512 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2513 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2514 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2515 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2516 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2517 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2518 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2519 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2520 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2521 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2523 - drivers/i2c/zynq_i2c.c
2524 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2525 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2526 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2528 - drivers/i2c/s3c24x0_i2c.c:
2529 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2530 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2531 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2532 with a fix speed from 100000 and the slave addr 0!
2534 - drivers/i2c/ihs_i2c.c
2535 - activate this driver with CONFIG_SYS_I2C_IHS
2536 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2537 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2538 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2539 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2540 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2541 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2542 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2543 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2544 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2545 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2546 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2547 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2551 CONFIG_SYS_NUM_I2C_BUSES
2552 Hold the number of i2c buses you want to use. If you
2553 don't use/have i2c muxes on your i2c bus, this
2554 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2557 CONFIG_SYS_I2C_DIRECT_BUS
2558 define this, if you don't use i2c muxes on your hardware.
2559 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2562 CONFIG_SYS_I2C_MAX_HOPS
2563 define how many muxes are maximal consecutively connected
2564 on one i2c bus. If you not use i2c muxes, omit this
2567 CONFIG_SYS_I2C_BUSES
2568 hold a list of buses you want to use, only used if
2569 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2570 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2571 CONFIG_SYS_NUM_I2C_BUSES = 9:
2573 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2574 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2575 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2576 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2577 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2578 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2579 {1, {I2C_NULL_HOP}}, \
2580 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2581 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2585 bus 0 on adapter 0 without a mux
2586 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2587 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2588 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2589 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2590 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2591 bus 6 on adapter 1 without a mux
2592 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2593 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2595 If you do not have i2c muxes on your board, omit this define.
2597 - Legacy I2C Support: CONFIG_HARD_I2C
2599 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2600 provides the following compelling advantages:
2602 - more than one i2c adapter is usable
2603 - approved multibus support
2604 - better i2c mux support
2606 ** Please consider updating your I2C driver now. **
2608 These enable legacy I2C serial bus commands. Defining
2609 CONFIG_HARD_I2C will include the appropriate I2C driver
2610 for the selected CPU.
2612 This will allow you to use i2c commands at the u-boot
2613 command line (as long as you set CONFIG_CMD_I2C in
2614 CONFIG_COMMANDS) and communicate with i2c based realtime
2615 clock chips. See common/cmd_i2c.c for a description of the
2616 command line interface.
2618 CONFIG_HARD_I2C selects a hardware I2C controller.
2620 There are several other quantities that must also be
2621 defined when you define CONFIG_HARD_I2C.
2623 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2624 to be the frequency (in Hz) at which you wish your i2c bus
2625 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2626 the CPU's i2c node address).
2628 Now, the u-boot i2c code for the mpc8xx
2629 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2630 and so its address should therefore be cleared to 0 (See,
2631 eg, MPC823e User's Manual p.16-473). So, set
2632 CONFIG_SYS_I2C_SLAVE to 0.
2634 CONFIG_SYS_I2C_INIT_MPC5XXX
2636 When a board is reset during an i2c bus transfer
2637 chips might think that the current transfer is still
2638 in progress. Reset the slave devices by sending start
2639 commands until the slave device responds.
2641 That's all that's required for CONFIG_HARD_I2C.
2643 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2644 then the following macros need to be defined (examples are
2645 from include/configs/lwmon.h):
2649 (Optional). Any commands necessary to enable the I2C
2650 controller or configure ports.
2652 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2656 (Only for MPC8260 CPU). The I/O port to use (the code
2657 assumes both bits are on the same port). Valid values
2658 are 0..3 for ports A..D.
2662 The code necessary to make the I2C data line active
2663 (driven). If the data line is open collector, this
2666 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2670 The code necessary to make the I2C data line tri-stated
2671 (inactive). If the data line is open collector, this
2674 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2678 Code that returns true if the I2C data line is high,
2681 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2685 If <bit> is true, sets the I2C data line high. If it
2686 is false, it clears it (low).
2688 eg: #define I2C_SDA(bit) \
2689 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2690 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2694 If <bit> is true, sets the I2C clock line high. If it
2695 is false, it clears it (low).
2697 eg: #define I2C_SCL(bit) \
2698 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2699 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2703 This delay is invoked four times per clock cycle so this
2704 controls the rate of data transfer. The data rate thus
2705 is 1 / (I2C_DELAY * 4). Often defined to be something
2708 #define I2C_DELAY udelay(2)
2710 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2712 If your arch supports the generic GPIO framework (asm/gpio.h),
2713 then you may alternatively define the two GPIOs that are to be
2714 used as SCL / SDA. Any of the previous I2C_xxx macros will
2715 have GPIO-based defaults assigned to them as appropriate.
2717 You should define these to the GPIO value as given directly to
2718 the generic GPIO functions.
2720 CONFIG_SYS_I2C_INIT_BOARD
2722 When a board is reset during an i2c bus transfer
2723 chips might think that the current transfer is still
2724 in progress. On some boards it is possible to access
2725 the i2c SCLK line directly, either by using the
2726 processor pin as a GPIO or by having a second pin
2727 connected to the bus. If this option is defined a
2728 custom i2c_init_board() routine in boards/xxx/board.c
2729 is run early in the boot sequence.
2731 CONFIG_SYS_I2C_BOARD_LATE_INIT
2733 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2734 defined a custom i2c_board_late_init() routine in
2735 boards/xxx/board.c is run AFTER the operations in i2c_init()
2736 is completed. This callpoint can be used to unreset i2c bus
2737 using CPU i2c controller register accesses for CPUs whose i2c
2738 controller provide such a method. It is called at the end of
2739 i2c_init() to allow i2c_init operations to setup the i2c bus
2740 controller on the CPU (e.g. setting bus speed & slave address).
2742 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2744 This option enables configuration of bi_iic_fast[] flags
2745 in u-boot bd_info structure based on u-boot environment
2746 variable "i2cfast". (see also i2cfast)
2748 CONFIG_I2C_MULTI_BUS
2750 This option allows the use of multiple I2C buses, each of which
2751 must have a controller. At any point in time, only one bus is
2752 active. To switch to a different bus, use the 'i2c dev' command.
2753 Note that bus numbering is zero-based.
2755 CONFIG_SYS_I2C_NOPROBES
2757 This option specifies a list of I2C devices that will be skipped
2758 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2759 is set, specify a list of bus-device pairs. Otherwise, specify
2760 a 1D array of device addresses
2763 #undef CONFIG_I2C_MULTI_BUS
2764 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2766 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2768 #define CONFIG_I2C_MULTI_BUS
2769 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2771 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2773 CONFIG_SYS_SPD_BUS_NUM
2775 If defined, then this indicates the I2C bus number for DDR SPD.
2776 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2778 CONFIG_SYS_RTC_BUS_NUM
2780 If defined, then this indicates the I2C bus number for the RTC.
2781 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2783 CONFIG_SYS_DTT_BUS_NUM
2785 If defined, then this indicates the I2C bus number for the DTT.
2786 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2788 CONFIG_SYS_I2C_DTT_ADDR:
2790 If defined, specifies the I2C address of the DTT device.
2791 If not defined, then U-Boot uses predefined value for
2792 specified DTT device.
2794 CONFIG_SOFT_I2C_READ_REPEATED_START
2796 defining this will force the i2c_read() function in
2797 the soft_i2c driver to perform an I2C repeated start
2798 between writing the address pointer and reading the
2799 data. If this define is omitted the default behaviour
2800 of doing a stop-start sequence will be used. Most I2C
2801 devices can use either method, but some require one or
2804 - SPI Support: CONFIG_SPI
2806 Enables SPI driver (so far only tested with
2807 SPI EEPROM, also an instance works with Crystal A/D and
2808 D/As on the SACSng board)
2812 Enables the driver for SPI controller on SuperH. Currently
2813 only SH7757 is supported.
2817 Enables extended (16-bit) SPI EEPROM addressing.
2818 (symmetrical to CONFIG_I2C_X)
2822 Enables a software (bit-bang) SPI driver rather than
2823 using hardware support. This is a general purpose
2824 driver that only requires three general I/O port pins
2825 (two outputs, one input) to function. If this is
2826 defined, the board configuration must define several
2827 SPI configuration items (port pins to use, etc). For
2828 an example, see include/configs/sacsng.h.
2832 Enables a hardware SPI driver for general-purpose reads
2833 and writes. As with CONFIG_SOFT_SPI, the board configuration
2834 must define a list of chip-select function pointers.
2835 Currently supported on some MPC8xxx processors. For an
2836 example, see include/configs/mpc8349emds.h.
2840 Enables the driver for the SPI controllers on i.MX and MXC
2841 SoCs. Currently i.MX31/35/51 are supported.
2843 CONFIG_SYS_SPI_MXC_WAIT
2844 Timeout for waiting until spi transfer completed.
2845 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2847 - FPGA Support: CONFIG_FPGA
2849 Enables FPGA subsystem.
2851 CONFIG_FPGA_<vendor>
2853 Enables support for specific chip vendors.
2856 CONFIG_FPGA_<family>
2858 Enables support for FPGA family.
2859 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2863 Specify the number of FPGA devices to support.
2865 CONFIG_CMD_FPGA_LOADMK
2867 Enable support for fpga loadmk command
2869 CONFIG_CMD_FPGA_LOADP
2871 Enable support for fpga loadp command - load partial bitstream
2873 CONFIG_CMD_FPGA_LOADBP
2875 Enable support for fpga loadbp command - load partial bitstream
2878 CONFIG_SYS_FPGA_PROG_FEEDBACK
2880 Enable printing of hash marks during FPGA configuration.
2882 CONFIG_SYS_FPGA_CHECK_BUSY
2884 Enable checks on FPGA configuration interface busy
2885 status by the configuration function. This option
2886 will require a board or device specific function to
2891 If defined, a function that provides delays in the FPGA
2892 configuration driver.
2894 CONFIG_SYS_FPGA_CHECK_CTRLC
2895 Allow Control-C to interrupt FPGA configuration
2897 CONFIG_SYS_FPGA_CHECK_ERROR
2899 Check for configuration errors during FPGA bitfile
2900 loading. For example, abort during Virtex II
2901 configuration if the INIT_B line goes low (which
2902 indicated a CRC error).
2904 CONFIG_SYS_FPGA_WAIT_INIT
2906 Maximum time to wait for the INIT_B line to de-assert
2907 after PROB_B has been de-asserted during a Virtex II
2908 FPGA configuration sequence. The default time is 500
2911 CONFIG_SYS_FPGA_WAIT_BUSY
2913 Maximum time to wait for BUSY to de-assert during
2914 Virtex II FPGA configuration. The default is 5 ms.
2916 CONFIG_SYS_FPGA_WAIT_CONFIG
2918 Time to wait after FPGA configuration. The default is
2921 - Configuration Management:
2924 Some SoCs need special image types (e.g. U-Boot binary
2925 with a special header) as build targets. By defining
2926 CONFIG_BUILD_TARGET in the SoC / board header, this
2927 special image will be automatically built upon calling
2932 If defined, this string will be added to the U-Boot
2933 version information (U_BOOT_VERSION)
2935 - Vendor Parameter Protection:
2937 U-Boot considers the values of the environment
2938 variables "serial#" (Board Serial Number) and
2939 "ethaddr" (Ethernet Address) to be parameters that
2940 are set once by the board vendor / manufacturer, and
2941 protects these variables from casual modification by
2942 the user. Once set, these variables are read-only,
2943 and write or delete attempts are rejected. You can
2944 change this behaviour:
2946 If CONFIG_ENV_OVERWRITE is #defined in your config
2947 file, the write protection for vendor parameters is
2948 completely disabled. Anybody can change or delete
2951 Alternatively, if you #define _both_ CONFIG_ETHADDR
2952 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2953 Ethernet address is installed in the environment,
2954 which can be changed exactly ONCE by the user. [The
2955 serial# is unaffected by this, i. e. it remains
2958 The same can be accomplished in a more flexible way
2959 for any variable by configuring the type of access
2960 to allow for those variables in the ".flags" variable
2961 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2966 Define this variable to enable the reservation of
2967 "protected RAM", i. e. RAM which is not overwritten
2968 by U-Boot. Define CONFIG_PRAM to hold the number of
2969 kB you want to reserve for pRAM. You can overwrite
2970 this default value by defining an environment
2971 variable "pram" to the number of kB you want to
2972 reserve. Note that the board info structure will
2973 still show the full amount of RAM. If pRAM is
2974 reserved, a new environment variable "mem" will
2975 automatically be defined to hold the amount of
2976 remaining RAM in a form that can be passed as boot
2977 argument to Linux, for instance like that:
2979 setenv bootargs ... mem=\${mem}
2982 This way you can tell Linux not to use this memory,
2983 either, which results in a memory region that will
2984 not be affected by reboots.
2986 *WARNING* If your board configuration uses automatic
2987 detection of the RAM size, you must make sure that
2988 this memory test is non-destructive. So far, the
2989 following board configurations are known to be
2992 IVMS8, IVML24, SPD8xx, TQM8xxL,
2993 HERMES, IP860, RPXlite, LWMON,
2996 - Access to physical memory region (> 4GB)
2997 Some basic support is provided for operations on memory not
2998 normally accessible to U-Boot - e.g. some architectures
2999 support access to more than 4GB of memory on 32-bit
3000 machines using physical address extension or similar.
3001 Define CONFIG_PHYSMEM to access this basic support, which
3002 currently only supports clearing the memory.
3007 Define this variable to stop the system in case of a
3008 fatal error, so that you have to reset it manually.
3009 This is probably NOT a good idea for an embedded
3010 system where you want the system to reboot
3011 automatically as fast as possible, but it may be
3012 useful during development since you can try to debug
3013 the conditions that lead to the situation.
3015 CONFIG_NET_RETRY_COUNT
3017 This variable defines the number of retries for
3018 network operations like ARP, RARP, TFTP, or BOOTP
3019 before giving up the operation. If not defined, a
3020 default value of 5 is used.
3024 Timeout waiting for an ARP reply in milliseconds.
3028 Timeout in milliseconds used in NFS protocol.
3029 If you encounter "ERROR: Cannot umount" in nfs command,
3030 try longer timeout such as
3031 #define CONFIG_NFS_TIMEOUT 10000UL
3033 - Command Interpreter:
3034 CONFIG_AUTO_COMPLETE
3036 Enable auto completion of commands using TAB.
3038 CONFIG_SYS_PROMPT_HUSH_PS2
3040 This defines the secondary prompt string, which is
3041 printed when the command interpreter needs more input
3042 to complete a command. Usually "> ".
3046 In the current implementation, the local variables
3047 space and global environment variables space are
3048 separated. Local variables are those you define by
3049 simply typing `name=value'. To access a local
3050 variable later on, you have write `$name' or
3051 `${name}'; to execute the contents of a variable
3052 directly type `$name' at the command prompt.
3054 Global environment variables are those you use
3055 setenv/printenv to work with. To run a command stored
3056 in such a variable, you need to use the run command,
3057 and you must not use the '$' sign to access them.
3059 To store commands and special characters in a
3060 variable, please use double quotation marks
3061 surrounding the whole text of the variable, instead
3062 of the backslashes before semicolons and special
3065 - Command Line Editing and History:
3066 CONFIG_CMDLINE_EDITING
3068 Enable editing and History functions for interactive
3069 command line input operations
3071 - Default Environment:
3072 CONFIG_EXTRA_ENV_SETTINGS
3074 Define this to contain any number of null terminated
3075 strings (variable = value pairs) that will be part of
3076 the default environment compiled into the boot image.
3078 For example, place something like this in your
3079 board's config file:
3081 #define CONFIG_EXTRA_ENV_SETTINGS \
3085 Warning: This method is based on knowledge about the
3086 internal format how the environment is stored by the
3087 U-Boot code. This is NOT an official, exported
3088 interface! Although it is unlikely that this format
3089 will change soon, there is no guarantee either.
3090 You better know what you are doing here.
3092 Note: overly (ab)use of the default environment is
3093 discouraged. Make sure to check other ways to preset
3094 the environment like the "source" command or the
3097 CONFIG_ENV_VARS_UBOOT_CONFIG
3099 Define this in order to add variables describing the
3100 U-Boot build configuration to the default environment.
3101 These will be named arch, cpu, board, vendor, and soc.
3103 Enabling this option will cause the following to be defined:
3111 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3113 Define this in order to add variables describing certain
3114 run-time determined information about the hardware to the
3115 environment. These will be named board_name, board_rev.
3117 CONFIG_DELAY_ENVIRONMENT
3119 Normally the environment is loaded when the board is
3120 initialised so that it is available to U-Boot. This inhibits
3121 that so that the environment is not available until
3122 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3123 this is instead controlled by the value of
3124 /config/load-environment.
3126 - DataFlash Support:
3127 CONFIG_HAS_DATAFLASH
3129 Defining this option enables DataFlash features and
3130 allows to read/write in Dataflash via the standard
3133 - Serial Flash support
3136 Defining this option enables SPI flash commands
3137 'sf probe/read/write/erase/update'.
3139 Usage requires an initial 'probe' to define the serial
3140 flash parameters, followed by read/write/erase/update
3143 The following defaults may be provided by the platform
3144 to handle the common case when only a single serial
3145 flash is present on the system.
3147 CONFIG_SF_DEFAULT_BUS Bus identifier
3148 CONFIG_SF_DEFAULT_CS Chip-select
3149 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3150 CONFIG_SF_DEFAULT_SPEED in Hz
3154 Define this option to include a destructive SPI flash
3157 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3159 Define this option to use the Bank addr/Extended addr
3160 support on SPI flashes which has size > 16Mbytes.
3162 CONFIG_SF_DUAL_FLASH Dual flash memories
3164 Define this option to use dual flash support where two flash
3165 memories can be connected with a given cs line.
3166 Currently Xilinx Zynq qspi supports these type of connections.
3168 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3169 enable the W#/Vpp signal to disable writing to the status
3170 register on ST MICRON flashes like the N25Q128.
3171 The status register write enable/disable bit, combined with
3172 the W#/VPP signal provides hardware data protection for the
3173 device as follows: When the enable/disable bit is set to 1,
3174 and the W#/VPP signal is driven LOW, the status register
3175 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3176 operation will not execute. The only way to exit this
3177 hardware-protected mode is to drive W#/VPP HIGH.
3179 - SystemACE Support:
3182 Adding this option adds support for Xilinx SystemACE
3183 chips attached via some sort of local bus. The address
3184 of the chip must also be defined in the
3185 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3187 #define CONFIG_SYSTEMACE
3188 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3190 When SystemACE support is added, the "ace" device type
3191 becomes available to the fat commands, i.e. fatls.
3193 - TFTP Fixed UDP Port:
3196 If this is defined, the environment variable tftpsrcp
3197 is used to supply the TFTP UDP source port value.
3198 If tftpsrcp isn't defined, the normal pseudo-random port
3199 number generator is used.
3201 Also, the environment variable tftpdstp is used to supply
3202 the TFTP UDP destination port value. If tftpdstp isn't
3203 defined, the normal port 69 is used.
3205 The purpose for tftpsrcp is to allow a TFTP server to
3206 blindly start the TFTP transfer using the pre-configured
3207 target IP address and UDP port. This has the effect of
3208 "punching through" the (Windows XP) firewall, allowing
3209 the remainder of the TFTP transfer to proceed normally.
3210 A better solution is to properly configure the firewall,
3211 but sometimes that is not allowed.
3216 This enables a generic 'hash' command which can produce
3217 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3221 Enable the hash verify command (hash -v). This adds to code
3224 CONFIG_SHA1 - This option enables support of hashing using SHA1
3225 algorithm. The hash is calculated in software.
3226 CONFIG_SHA256 - This option enables support of hashing using
3227 SHA256 algorithm. The hash is calculated in software.
3228 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3229 for SHA1/SHA256 hashing.
3230 This affects the 'hash' command and also the
3231 hash_lookup_algo() function.
3232 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3233 hardware-acceleration for SHA1/SHA256 progressive hashing.
3234 Data can be streamed in a block at a time and the hashing
3235 is performed in hardware.
3237 Note: There is also a sha1sum command, which should perhaps
3238 be deprecated in favour of 'hash sha1'.
3240 - Freescale i.MX specific commands:
3241 CONFIG_CMD_HDMIDETECT
3242 This enables 'hdmidet' command which returns true if an
3243 HDMI monitor is detected. This command is i.MX 6 specific.
3246 This enables the 'bmode' (bootmode) command for forcing
3247 a boot from specific media.
3249 This is useful for forcing the ROM's usb downloader to
3250 activate upon a watchdog reset which is nice when iterating
3251 on U-Boot. Using the reset button or running bmode normal
3252 will set it back to normal. This command currently
3253 supports i.MX53 and i.MX6.
3258 This enables the RSA algorithm used for FIT image verification
3259 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3261 The Modular Exponentiation algorithm in RSA is implemented using
3262 driver model. So CONFIG_DM needs to be enabled by default for this
3263 library to function.
3265 The signing part is build into mkimage regardless of this
3266 option. The software based modular exponentiation is built into
3267 mkimage irrespective of this option.
3269 - bootcount support:
3270 CONFIG_BOOTCOUNT_LIMIT
3272 This enables the bootcounter support, see:
3273 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3276 enable special bootcounter support on at91sam9xe based boards.
3278 enable special bootcounter support on blackfin based boards.
3280 enable special bootcounter support on da850 based boards.
3281 CONFIG_BOOTCOUNT_RAM
3282 enable support for the bootcounter in RAM
3283 CONFIG_BOOTCOUNT_I2C
3284 enable support for the bootcounter on an i2c (like RTC) device.
3285 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3286 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3288 CONFIG_BOOTCOUNT_ALEN = address len
3290 - Show boot progress:
3291 CONFIG_SHOW_BOOT_PROGRESS
3293 Defining this option allows to add some board-
3294 specific code (calling a user-provided function
3295 "show_boot_progress(int)") that enables you to show
3296 the system's boot progress on some display (for
3297 example, some LED's) on your board. At the moment,
3298 the following checkpoints are implemented:
3300 - Detailed boot stage timing
3302 Define this option to get detailed timing of each stage
3303 of the boot process.
3305 CONFIG_BOOTSTAGE_USER_COUNT
3306 This is the number of available user bootstage records.
3307 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3308 a new ID will be allocated from this stash. If you exceed
3309 the limit, recording will stop.
3311 CONFIG_BOOTSTAGE_REPORT
3312 Define this to print a report before boot, similar to this:
3314 Timer summary in microseconds:
3317 3,575,678 3,575,678 board_init_f start
3318 3,575,695 17 arch_cpu_init A9
3319 3,575,777 82 arch_cpu_init done
3320 3,659,598 83,821 board_init_r start
3321 3,910,375 250,777 main_loop
3322 29,916,167 26,005,792 bootm_start
3323 30,361,327 445,160 start_kernel
3325 CONFIG_CMD_BOOTSTAGE
3326 Add a 'bootstage' command which supports printing a report
3327 and un/stashing of bootstage data.
3329 CONFIG_BOOTSTAGE_FDT
3330 Stash the bootstage information in the FDT. A root 'bootstage'
3331 node is created with each bootstage id as a child. Each child
3332 has a 'name' property and either 'mark' containing the
3333 mark time in microsecond, or 'accum' containing the
3334 accumulated time for that bootstage id in microseconds.
3339 name = "board_init_f";
3348 Code in the Linux kernel can find this in /proc/devicetree.
3350 Legacy uImage format:
3353 1 common/cmd_bootm.c before attempting to boot an image
3354 -1 common/cmd_bootm.c Image header has bad magic number
3355 2 common/cmd_bootm.c Image header has correct magic number
3356 -2 common/cmd_bootm.c Image header has bad checksum
3357 3 common/cmd_bootm.c Image header has correct checksum
3358 -3 common/cmd_bootm.c Image data has bad checksum
3359 4 common/cmd_bootm.c Image data has correct checksum
3360 -4 common/cmd_bootm.c Image is for unsupported architecture
3361 5 common/cmd_bootm.c Architecture check OK
3362 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3363 6 common/cmd_bootm.c Image Type check OK
3364 -6 common/cmd_bootm.c gunzip uncompression error
3365 -7 common/cmd_bootm.c Unimplemented compression type
3366 7 common/cmd_bootm.c Uncompression OK
3367 8 common/cmd_bootm.c No uncompress/copy overwrite error
3368 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3370 9 common/image.c Start initial ramdisk verification
3371 -10 common/image.c Ramdisk header has bad magic number
3372 -11 common/image.c Ramdisk header has bad checksum
3373 10 common/image.c Ramdisk header is OK
3374 -12 common/image.c Ramdisk data has bad checksum
3375 11 common/image.c Ramdisk data has correct checksum
3376 12 common/image.c Ramdisk verification complete, start loading
3377 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3378 13 common/image.c Start multifile image verification
3379 14 common/image.c No initial ramdisk, no multifile, continue.
3381 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3383 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3384 -31 post/post.c POST test failed, detected by post_output_backlog()
3385 -32 post/post.c POST test failed, detected by post_run_single()
3387 34 common/cmd_doc.c before loading a Image from a DOC device
3388 -35 common/cmd_doc.c Bad usage of "doc" command
3389 35 common/cmd_doc.c correct usage of "doc" command
3390 -36 common/cmd_doc.c No boot device
3391 36 common/cmd_doc.c correct boot device
3392 -37 common/cmd_doc.c Unknown Chip ID on boot device
3393 37 common/cmd_doc.c correct chip ID found, device available
3394 -38 common/cmd_doc.c Read Error on boot device
3395 38 common/cmd_doc.c reading Image header from DOC device OK
3396 -39 common/cmd_doc.c Image header has bad magic number
3397 39 common/cmd_doc.c Image header has correct magic number
3398 -40 common/cmd_doc.c Error reading Image from DOC device
3399 40 common/cmd_doc.c Image header has correct magic number
3400 41 common/cmd_ide.c before loading a Image from a IDE device
3401 -42 common/cmd_ide.c Bad usage of "ide" command
3402 42 common/cmd_ide.c correct usage of "ide" command
3403 -43 common/cmd_ide.c No boot device
3404 43 common/cmd_ide.c boot device found
3405 -44 common/cmd_ide.c Device not available
3406 44 common/cmd_ide.c Device available
3407 -45 common/cmd_ide.c wrong partition selected
3408 45 common/cmd_ide.c partition selected
3409 -46 common/cmd_ide.c Unknown partition table
3410 46 common/cmd_ide.c valid partition table found
3411 -47 common/cmd_ide.c Invalid partition type
3412 47 common/cmd_ide.c correct partition type
3413 -48 common/cmd_ide.c Error reading Image Header on boot device
3414 48 common/cmd_ide.c reading Image Header from IDE device OK
3415 -49 common/cmd_ide.c Image header has bad magic number
3416 49 common/cmd_ide.c Image header has correct magic number
3417 -50 common/cmd_ide.c Image header has bad checksum
3418 50 common/cmd_ide.c Image header has correct checksum
3419 -51 common/cmd_ide.c Error reading Image from IDE device
3420 51 common/cmd_ide.c reading Image from IDE device OK
3421 52 common/cmd_nand.c before loading a Image from a NAND device
3422 -53 common/cmd_nand.c Bad usage of "nand" command
3423 53 common/cmd_nand.c correct usage of "nand" command
3424 -54 common/cmd_nand.c No boot device
3425 54 common/cmd_nand.c boot device found
3426 -55 common/cmd_nand.c Unknown Chip ID on boot device
3427 55 common/cmd_nand.c correct chip ID found, device available
3428 -56 common/cmd_nand.c Error reading Image Header on boot device
3429 56 common/cmd_nand.c reading Image Header from NAND device OK
3430 -57 common/cmd_nand.c Image header has bad magic number
3431 57 common/cmd_nand.c Image header has correct magic number
3432 -58 common/cmd_nand.c Error reading Image from NAND device
3433 58 common/cmd_nand.c reading Image from NAND device OK
3435 -60 common/env_common.c Environment has a bad CRC, using default
3437 64 net/eth.c starting with Ethernet configuration.
3438 -64 net/eth.c no Ethernet found.
3439 65 net/eth.c Ethernet found.
3441 -80 common/cmd_net.c usage wrong
3442 80 common/cmd_net.c before calling NetLoop()
3443 -81 common/cmd_net.c some error in NetLoop() occurred
3444 81 common/cmd_net.c NetLoop() back without error
3445 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3446 82 common/cmd_net.c trying automatic boot
3447 83 common/cmd_net.c running "source" command
3448 -83 common/cmd_net.c some error in automatic boot or "source" command
3449 84 common/cmd_net.c end without errors
3454 100 common/cmd_bootm.c Kernel FIT Image has correct format
3455 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3456 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3457 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3458 102 common/cmd_bootm.c Kernel unit name specified
3459 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3460 103 common/cmd_bootm.c Found configuration node
3461 104 common/cmd_bootm.c Got kernel subimage node offset
3462 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3463 105 common/cmd_bootm.c Kernel subimage hash verification OK
3464 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3465 106 common/cmd_bootm.c Architecture check OK
3466 -106 common/cmd_bootm.c Kernel subimage has wrong type
3467 107 common/cmd_bootm.c Kernel subimage type OK
3468 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3469 108 common/cmd_bootm.c Got kernel subimage data/size
3470 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3471 -109 common/cmd_bootm.c Can't get kernel subimage type
3472 -110 common/cmd_bootm.c Can't get kernel subimage comp
3473 -111 common/cmd_bootm.c Can't get kernel subimage os
3474 -112 common/cmd_bootm.c Can't get kernel subimage load address
3475 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3477 120 common/image.c Start initial ramdisk verification
3478 -120 common/image.c Ramdisk FIT image has incorrect format
3479 121 common/image.c Ramdisk FIT image has correct format
3480 122 common/image.c No ramdisk subimage unit name, using configuration
3481 -122 common/image.c Can't get configuration for ramdisk subimage
3482 123 common/image.c Ramdisk unit name specified
3483 -124 common/image.c Can't get ramdisk subimage node offset
3484 125 common/image.c Got ramdisk subimage node offset
3485 -125 common/image.c Ramdisk subimage hash verification failed
3486 126 common/image.c Ramdisk subimage hash verification OK
3487 -126 common/image.c Ramdisk subimage for unsupported architecture
3488 127 common/image.c Architecture check OK
3489 -127 common/image.c Can't get ramdisk subimage data/size
3490 128 common/image.c Got ramdisk subimage data/size
3491 129 common/image.c Can't get ramdisk load address
3492 -129 common/image.c Got ramdisk load address
3494 -130 common/cmd_doc.c Incorrect FIT image format
3495 131 common/cmd_doc.c FIT image format OK
3497 -140 common/cmd_ide.c Incorrect FIT image format
3498 141 common/cmd_ide.c FIT image format OK
3500 -150 common/cmd_nand.c Incorrect FIT image format
3501 151 common/cmd_nand.c FIT image format OK
3503 - legacy image format:
3504 CONFIG_IMAGE_FORMAT_LEGACY
3505 enables the legacy image format support in U-Boot.
3508 enabled if CONFIG_FIT_SIGNATURE is not defined.
3510 CONFIG_DISABLE_IMAGE_LEGACY
3511 disable the legacy image format
3513 This define is introduced, as the legacy image format is
3514 enabled per default for backward compatibility.
3516 - FIT image support:
3518 Enable support for the FIT uImage format.
3520 CONFIG_FIT_BEST_MATCH
3521 When no configuration is explicitly selected, default to the
3522 one whose fdt's compatibility field best matches that of
3523 U-Boot itself. A match is considered "best" if it matches the
3524 most specific compatibility entry of U-Boot's fdt's root node.
3525 The order of entries in the configuration's fdt is ignored.
3527 CONFIG_FIT_SIGNATURE
3528 This option enables signature verification of FIT uImages,
3529 using a hash signed and verified using RSA. If
3530 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3531 hashing is available using hardware, RSA library will use it.
3532 See doc/uImage.FIT/signature.txt for more details.
3534 WARNING: When relying on signed FIT images with required
3535 signature check the legacy image format is default
3536 disabled. If a board need legacy image format support
3537 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3539 CONFIG_FIT_DISABLE_SHA256
3540 Supporting SHA256 hashes has quite an impact on binary size.
3541 For constrained systems sha256 hash support can be disabled
3544 - Standalone program support:
3545 CONFIG_STANDALONE_LOAD_ADDR
3547 This option defines a board specific value for the
3548 address where standalone program gets loaded, thus
3549 overwriting the architecture dependent default
3552 - Frame Buffer Address:
3555 Define CONFIG_FB_ADDR if you want to use specific
3556 address for frame buffer. This is typically the case
3557 when using a graphics controller has separate video
3558 memory. U-Boot will then place the frame buffer at
3559 the given address instead of dynamically reserving it
3560 in system RAM by calling lcd_setmem(), which grabs
3561 the memory for the frame buffer depending on the
3562 configured panel size.
3564 Please see board_init_f function.
3566 - Automatic software updates via TFTP server
3568 CONFIG_UPDATE_TFTP_CNT_MAX
3569 CONFIG_UPDATE_TFTP_MSEC_MAX
3571 These options enable and control the auto-update feature;
3572 for a more detailed description refer to doc/README.update.
3574 - MTD Support (mtdparts command, UBI support)
3577 Adds the MTD device infrastructure from the Linux kernel.
3578 Needed for mtdparts command support.
3580 CONFIG_MTD_PARTITIONS
3582 Adds the MTD partitioning infrastructure from the Linux
3583 kernel. Needed for UBI support.
3585 CONFIG_MTD_NAND_VERIFY_WRITE
3586 verify if the written data is correct reread.
3591 Adds commands for interacting with MTD partitions formatted
3592 with the UBI flash translation layer
3594 Requires also defining CONFIG_RBTREE
3596 CONFIG_UBI_SILENCE_MSG
3598 Make the verbose messages from UBI stop printing. This leaves
3599 warnings and errors enabled.
3602 CONFIG_MTD_UBI_WL_THRESHOLD
3603 This parameter defines the maximum difference between the highest
3604 erase counter value and the lowest erase counter value of eraseblocks
3605 of UBI devices. When this threshold is exceeded, UBI starts performing
3606 wear leveling by means of moving data from eraseblock with low erase
3607 counter to eraseblocks with high erase counter.
3609 The default value should be OK for SLC NAND flashes, NOR flashes and
3610 other flashes which have eraseblock life-cycle 100000 or more.
3611 However, in case of MLC NAND flashes which typically have eraseblock
3612 life-cycle less than 10000, the threshold should be lessened (e.g.,
3613 to 128 or 256, although it does not have to be power of 2).
3617 CONFIG_MTD_UBI_BEB_LIMIT
3618 This option specifies the maximum bad physical eraseblocks UBI
3619 expects on the MTD device (per 1024 eraseblocks). If the
3620 underlying flash does not admit of bad eraseblocks (e.g. NOR
3621 flash), this value is ignored.
3623 NAND datasheets often specify the minimum and maximum NVM
3624 (Number of Valid Blocks) for the flashes' endurance lifetime.
3625 The maximum expected bad eraseblocks per 1024 eraseblocks
3626 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3627 which gives 20 for most NANDs (MaxNVB is basically the total
3628 count of eraseblocks on the chip).
3630 To put it differently, if this value is 20, UBI will try to
3631 reserve about 1.9% of physical eraseblocks for bad blocks
3632 handling. And that will be 1.9% of eraseblocks on the entire
3633 NAND chip, not just the MTD partition UBI attaches. This means
3634 that if you have, say, a NAND flash chip admits maximum 40 bad
3635 eraseblocks, and it is split on two MTD partitions of the same
3636 size, UBI will reserve 40 eraseblocks when attaching a
3641 CONFIG_MTD_UBI_FASTMAP
3642 Fastmap is a mechanism which allows attaching an UBI device
3643 in nearly constant time. Instead of scanning the whole MTD device it
3644 only has to locate a checkpoint (called fastmap) on the device.
3645 The on-flash fastmap contains all information needed to attach
3646 the device. Using fastmap makes only sense on large devices where
3647 attaching by scanning takes long. UBI will not automatically install
3648 a fastmap on old images, but you can set the UBI parameter
3649 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3650 that fastmap-enabled images are still usable with UBI implementations
3651 without fastmap support. On typical flash devices the whole fastmap
3652 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3654 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3655 Set this parameter to enable fastmap automatically on images
3662 Adds commands for interacting with UBI volumes formatted as
3663 UBIFS. UBIFS is read-only in u-boot.
3665 Requires UBI support as well as CONFIG_LZO
3667 CONFIG_UBIFS_SILENCE_MSG
3669 Make the verbose messages from UBIFS stop printing. This leaves
3670 warnings and errors enabled.
3674 Enable building of SPL globally.
3677 LDSCRIPT for linking the SPL binary.
3679 CONFIG_SPL_MAX_FOOTPRINT
3680 Maximum size in memory allocated to the SPL, BSS included.
3681 When defined, the linker checks that the actual memory
3682 used by SPL from _start to __bss_end does not exceed it.
3683 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3684 must not be both defined at the same time.
3687 Maximum size of the SPL image (text, data, rodata, and
3688 linker lists sections), BSS excluded.
3689 When defined, the linker checks that the actual size does
3692 CONFIG_SPL_TEXT_BASE
3693 TEXT_BASE for linking the SPL binary.
3695 CONFIG_SPL_RELOC_TEXT_BASE
3696 Address to relocate to. If unspecified, this is equal to
3697 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3699 CONFIG_SPL_BSS_START_ADDR
3700 Link address for the BSS within the SPL binary.
3702 CONFIG_SPL_BSS_MAX_SIZE
3703 Maximum size in memory allocated to the SPL BSS.
3704 When defined, the linker checks that the actual memory used
3705 by SPL from __bss_start to __bss_end does not exceed it.
3706 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3707 must not be both defined at the same time.
3710 Adress of the start of the stack SPL will use
3712 CONFIG_SPL_RELOC_STACK
3713 Adress of the start of the stack SPL will use after
3714 relocation. If unspecified, this is equal to
3717 CONFIG_SYS_SPL_MALLOC_START
3718 Starting address of the malloc pool used in SPL.
3720 CONFIG_SYS_SPL_MALLOC_SIZE
3721 The size of the malloc pool used in SPL.
3723 CONFIG_SPL_FRAMEWORK
3724 Enable the SPL framework under common/. This framework
3725 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3726 NAND loading of the Linux Kernel.
3729 Enable booting directly to an OS from SPL.
3730 See also: doc/README.falcon
3732 CONFIG_SPL_DISPLAY_PRINT
3733 For ARM, enable an optional function to print more information
3734 about the running system.
3736 CONFIG_SPL_INIT_MINIMAL
3737 Arch init code should be built for a very small image
3739 CONFIG_SPL_LIBCOMMON_SUPPORT
3740 Support for common/libcommon.o in SPL binary
3742 CONFIG_SPL_LIBDISK_SUPPORT
3743 Support for disk/libdisk.o in SPL binary
3745 CONFIG_SPL_I2C_SUPPORT
3746 Support for drivers/i2c/libi2c.o in SPL binary
3748 CONFIG_SPL_GPIO_SUPPORT
3749 Support for drivers/gpio/libgpio.o in SPL binary
3751 CONFIG_SPL_MMC_SUPPORT
3752 Support for drivers/mmc/libmmc.o in SPL binary
3754 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3755 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3756 Address and partition on the MMC to load U-Boot from
3757 when the MMC is being used in raw mode.
3759 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3760 Partition on the MMC to load U-Boot from when the MMC is being
3763 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3764 Sector to load kernel uImage from when MMC is being
3765 used in raw mode (for Falcon mode)
3767 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3768 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3769 Sector and number of sectors to load kernel argument
3770 parameters from when MMC is being used in raw mode
3773 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3774 Partition on the MMC to load U-Boot from when the MMC is being
3777 CONFIG_SPL_FAT_SUPPORT
3778 Support for fs/fat/libfat.o in SPL binary
3780 CONFIG_SPL_EXT_SUPPORT
3781 Support for EXT filesystem in SPL binary
3783 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3784 Filename to read to load U-Boot when reading from filesystem
3786 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3787 Filename to read to load kernel uImage when reading
3788 from filesystem (for Falcon mode)
3790 CONFIG_SPL_FS_LOAD_ARGS_NAME
3791 Filename to read to load kernel argument parameters
3792 when reading from filesystem (for Falcon mode)
3794 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3795 Set this for NAND SPL on PPC mpc83xx targets, so that
3796 start.S waits for the rest of the SPL to load before
3797 continuing (the hardware starts execution after just
3798 loading the first page rather than the full 4K).
3800 CONFIG_SPL_SKIP_RELOCATE
3801 Avoid SPL relocation
3803 CONFIG_SPL_NAND_BASE
3804 Include nand_base.c in the SPL. Requires
3805 CONFIG_SPL_NAND_DRIVERS.
3807 CONFIG_SPL_NAND_DRIVERS
3808 SPL uses normal NAND drivers, not minimal drivers.
3811 Include standard software ECC in the SPL
3813 CONFIG_SPL_NAND_SIMPLE
3814 Support for NAND boot using simple NAND drivers that
3815 expose the cmd_ctrl() interface.
3817 CONFIG_SPL_MTD_SUPPORT
3818 Support for the MTD subsystem within SPL. Useful for
3819 environment on NAND support within SPL.
3821 CONFIG_SPL_NAND_RAW_ONLY
3822 Support to boot only raw u-boot.bin images. Use this only
3823 if you need to save space.
3825 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3826 Set for the SPL on PPC mpc8xxx targets, support for
3827 drivers/ddr/fsl/libddr.o in SPL binary.
3829 CONFIG_SPL_COMMON_INIT_DDR
3830 Set for common ddr init with serial presence detect in
3833 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3834 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3835 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3836 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3837 CONFIG_SYS_NAND_ECCBYTES
3838 Defines the size and behavior of the NAND that SPL uses
3841 CONFIG_SPL_NAND_BOOT
3842 Add support NAND boot
3844 CONFIG_SYS_NAND_U_BOOT_OFFS
3845 Location in NAND to read U-Boot from
3847 CONFIG_SYS_NAND_U_BOOT_DST
3848 Location in memory to load U-Boot to
3850 CONFIG_SYS_NAND_U_BOOT_SIZE
3851 Size of image to load
3853 CONFIG_SYS_NAND_U_BOOT_START
3854 Entry point in loaded image to jump to
3856 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3857 Define this if you need to first read the OOB and then the
3858 data. This is used, for example, on davinci platforms.
3860 CONFIG_SPL_OMAP3_ID_NAND
3861 Support for an OMAP3-specific set of functions to return the
3862 ID and MFR of the first attached NAND chip, if present.
3864 CONFIG_SPL_SERIAL_SUPPORT
3865 Support for drivers/serial/libserial.o in SPL binary
3867 CONFIG_SPL_SPI_FLASH_SUPPORT
3868 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3870 CONFIG_SPL_SPI_SUPPORT
3871 Support for drivers/spi/libspi.o in SPL binary
3873 CONFIG_SPL_RAM_DEVICE
3874 Support for running image already present in ram, in SPL binary
3876 CONFIG_SPL_LIBGENERIC_SUPPORT
3877 Support for lib/libgeneric.o in SPL binary
3879 CONFIG_SPL_ENV_SUPPORT
3880 Support for the environment operating in SPL binary
3882 CONFIG_SPL_NET_SUPPORT
3883 Support for the net/libnet.o in SPL binary.
3884 It conflicts with SPL env from storage medium specified by
3885 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3888 Image offset to which the SPL should be padded before appending
3889 the SPL payload. By default, this is defined as
3890 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3891 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3892 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3895 Final target image containing SPL and payload. Some SPLs
3896 use an arch-specific makefile fragment instead, for
3897 example if more than one image needs to be produced.
3899 CONFIG_FIT_SPL_PRINT
3900 Printing information about a FIT image adds quite a bit of
3901 code to SPL. So this is normally disabled in SPL. Use this
3902 option to re-enable it. This will affect the output of the
3903 bootm command when booting a FIT image.
3907 Enable building of TPL globally.
3910 Image offset to which the TPL should be padded before appending
3911 the TPL payload. By default, this is defined as
3912 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3913 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3914 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3919 [so far only for SMDK2400 boards]
3921 - Modem support enable:
3922 CONFIG_MODEM_SUPPORT
3924 - RTS/CTS Flow control enable:
3927 - Modem debug support:
3928 CONFIG_MODEM_SUPPORT_DEBUG
3930 Enables debugging stuff (char screen[1024], dbg())
3931 for modem support. Useful only with BDI2000.
3933 - Interrupt support (PPC):
3935 There are common interrupt_init() and timer_interrupt()
3936 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3937 for CPU specific initialization. interrupt_init_cpu()
3938 should set decrementer_count to appropriate value. If
3939 CPU resets decrementer automatically after interrupt
3940 (ppc4xx) it should set decrementer_count to zero.
3941 timer_interrupt() calls timer_interrupt_cpu() for CPU
3942 specific handling. If board has watchdog / status_led
3943 / other_activity_monitor it works automatically from
3944 general timer_interrupt().
3948 In the target system modem support is enabled when a
3949 specific key (key combination) is pressed during
3950 power-on. Otherwise U-Boot will boot normally
3951 (autoboot). The key_pressed() function is called from
3952 board_init(). Currently key_pressed() is a dummy
3953 function, returning 1 and thus enabling modem
3956 If there are no modem init strings in the
3957 environment, U-Boot proceed to autoboot; the
3958 previous output (banner, info printfs) will be
3961 See also: doc/README.Modem
3963 Board initialization settings:
3964 ------------------------------
3966 During Initialization u-boot calls a number of board specific functions
3967 to allow the preparation of board specific prerequisites, e.g. pin setup
3968 before drivers are initialized. To enable these callbacks the
3969 following configuration macros have to be defined. Currently this is
3970 architecture specific, so please check arch/your_architecture/lib/board.c
3971 typically in board_init_f() and board_init_r().
3973 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3974 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3975 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3976 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3978 Configuration Settings:
3979 -----------------------
3981 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3982 Optionally it can be defined to support 64-bit memory commands.
3984 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3985 undefine this when you're short of memory.
3987 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3988 width of the commands listed in the 'help' command output.
3990 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3991 prompt for user input.
3993 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3995 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3997 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3999 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
4000 the application (usually a Linux kernel) when it is
4003 - CONFIG_SYS_BAUDRATE_TABLE:
4004 List of legal baudrate settings for this board.
4006 - CONFIG_SYS_CONSOLE_INFO_QUIET
4007 Suppress display of console information at boot.
4009 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4010 If the board specific function
4011 extern int overwrite_console (void);
4012 returns 1, the stdin, stderr and stdout are switched to the
4013 serial port, else the settings in the environment are used.
4015 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4016 Enable the call to overwrite_console().
4018 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4019 Enable overwrite of previous console environment settings.
4021 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4022 Begin and End addresses of the area used by the
4025 - CONFIG_SYS_ALT_MEMTEST:
4026 Enable an alternate, more extensive memory test.
4028 - CONFIG_SYS_MEMTEST_SCRATCH:
4029 Scratch address used by the alternate memory test
4030 You only need to set this if address zero isn't writeable
4032 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4033 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4034 this specified memory area will get subtracted from the top
4035 (end) of RAM and won't get "touched" at all by U-Boot. By
4036 fixing up gd->ram_size the Linux kernel should gets passed
4037 the now "corrected" memory size and won't touch it either.
4038 This should work for arch/ppc and arch/powerpc. Only Linux
4039 board ports in arch/powerpc with bootwrapper support that
4040 recalculate the memory size from the SDRAM controller setup
4041 will have to get fixed in Linux additionally.
4043 This option can be used as a workaround for the 440EPx/GRx
4044 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4047 WARNING: Please make sure that this value is a multiple of
4048 the Linux page size (normally 4k). If this is not the case,
4049 then the end address of the Linux memory will be located at a
4050 non page size aligned address and this could cause major
4053 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4054 Enable temporary baudrate change while serial download
4056 - CONFIG_SYS_SDRAM_BASE:
4057 Physical start address of SDRAM. _Must_ be 0 here.
4059 - CONFIG_SYS_MBIO_BASE:
4060 Physical start address of Motherboard I/O (if using a
4063 - CONFIG_SYS_FLASH_BASE:
4064 Physical start address of Flash memory.
4066 - CONFIG_SYS_MONITOR_BASE:
4067 Physical start address of boot monitor code (set by
4068 make config files to be same as the text base address
4069 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4070 CONFIG_SYS_FLASH_BASE when booting from flash.
4072 - CONFIG_SYS_MONITOR_LEN:
4073 Size of memory reserved for monitor code, used to
4074 determine _at_compile_time_ (!) if the environment is
4075 embedded within the U-Boot image, or in a separate
4078 - CONFIG_SYS_MALLOC_LEN:
4079 Size of DRAM reserved for malloc() use.
4081 - CONFIG_SYS_MALLOC_F_LEN
4082 Size of the malloc() pool for use before relocation. If
4083 this is defined, then a very simple malloc() implementation
4084 will become available before relocation. The address is just
4085 below the global data, and the stack is moved down to make
4088 This feature allocates regions with increasing addresses
4089 within the region. calloc() is supported, but realloc()
4090 is not available. free() is supported but does nothing.
4091 The memory will be freed (or in fact just forgotten) when
4092 U-Boot relocates itself.
4094 Pre-relocation malloc() is only supported on ARM and sandbox
4095 at present but is fairly easy to enable for other archs.
4097 - CONFIG_SYS_MALLOC_SIMPLE
4098 Provides a simple and small malloc() and calloc() for those
4099 boards which do not use the full malloc in SPL (which is
4100 enabled with CONFIG_SYS_SPL_MALLOC_START).
4102 - CONFIG_SYS_NONCACHED_MEMORY:
4103 Size of non-cached memory area. This area of memory will be
4104 typically located right below the malloc() area and mapped
4105 uncached in the MMU. This is useful for drivers that would
4106 otherwise require a lot of explicit cache maintenance. For
4107 some drivers it's also impossible to properly maintain the
4108 cache. For example if the regions that need to be flushed
4109 are not a multiple of the cache-line size, *and* padding
4110 cannot be allocated between the regions to align them (i.e.
4111 if the HW requires a contiguous array of regions, and the
4112 size of each region is not cache-aligned), then a flush of
4113 one region may result in overwriting data that hardware has
4114 written to another region in the same cache-line. This can
4115 happen for example in network drivers where descriptors for
4116 buffers are typically smaller than the CPU cache-line (e.g.
4117 16 bytes vs. 32 or 64 bytes).
4119 Non-cached memory is only supported on 32-bit ARM at present.
4121 - CONFIG_SYS_BOOTM_LEN:
4122 Normally compressed uImages are limited to an
4123 uncompressed size of 8 MBytes. If this is not enough,
4124 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4125 to adjust this setting to your needs.
4127 - CONFIG_SYS_BOOTMAPSZ:
4128 Maximum size of memory mapped by the startup code of
4129 the Linux kernel; all data that must be processed by
4130 the Linux kernel (bd_info, boot arguments, FDT blob if
4131 used) must be put below this limit, unless "bootm_low"
4132 environment variable is defined and non-zero. In such case
4133 all data for the Linux kernel must be between "bootm_low"
4134 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4135 variable "bootm_mapsize" will override the value of
4136 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4137 then the value in "bootm_size" will be used instead.
4139 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4140 Enable initrd_high functionality. If defined then the
4141 initrd_high feature is enabled and the bootm ramdisk subcommand
4144 - CONFIG_SYS_BOOT_GET_CMDLINE:
4145 Enables allocating and saving kernel cmdline in space between
4146 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4148 - CONFIG_SYS_BOOT_GET_KBD:
4149 Enables allocating and saving a kernel copy of the bd_info in
4150 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4152 - CONFIG_SYS_MAX_FLASH_BANKS:
4153 Max number of Flash memory banks
4155 - CONFIG_SYS_MAX_FLASH_SECT:
4156 Max number of sectors on a Flash chip
4158 - CONFIG_SYS_FLASH_ERASE_TOUT:
4159 Timeout for Flash erase operations (in ms)
4161 - CONFIG_SYS_FLASH_WRITE_TOUT:
4162 Timeout for Flash write operations (in ms)
4164 - CONFIG_SYS_FLASH_LOCK_TOUT
4165 Timeout for Flash set sector lock bit operation (in ms)
4167 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4168 Timeout for Flash clear lock bits operation (in ms)
4170 - CONFIG_SYS_FLASH_PROTECTION
4171 If defined, hardware flash sectors protection is used
4172 instead of U-Boot software protection.
4174 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4176 Enable TFTP transfers directly to flash memory;
4177 without this option such a download has to be
4178 performed in two steps: (1) download to RAM, and (2)
4179 copy from RAM to flash.
4181 The two-step approach is usually more reliable, since
4182 you can check if the download worked before you erase
4183 the flash, but in some situations (when system RAM is
4184 too limited to allow for a temporary copy of the
4185 downloaded image) this option may be very useful.
4187 - CONFIG_SYS_FLASH_CFI:
4188 Define if the flash driver uses extra elements in the
4189 common flash structure for storing flash geometry.
4191 - CONFIG_FLASH_CFI_DRIVER
4192 This option also enables the building of the cfi_flash driver
4193 in the drivers directory
4195 - CONFIG_FLASH_CFI_MTD
4196 This option enables the building of the cfi_mtd driver
4197 in the drivers directory. The driver exports CFI flash
4200 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4201 Use buffered writes to flash.
4203 - CONFIG_FLASH_SPANSION_S29WS_N
4204 s29ws-n MirrorBit flash has non-standard addresses for buffered
4207 - CONFIG_SYS_FLASH_QUIET_TEST
4208 If this option is defined, the common CFI flash doesn't
4209 print it's warning upon not recognized FLASH banks. This
4210 is useful, if some of the configured banks are only
4211 optionally available.
4213 - CONFIG_FLASH_SHOW_PROGRESS
4214 If defined (must be an integer), print out countdown
4215 digits and dots. Recommended value: 45 (9..1) for 80
4216 column displays, 15 (3..1) for 40 column displays.
4218 - CONFIG_FLASH_VERIFY
4219 If defined, the content of the flash (destination) is compared
4220 against the source after the write operation. An error message
4221 will be printed when the contents are not identical.
4222 Please note that this option is useless in nearly all cases,
4223 since such flash programming errors usually are detected earlier
4224 while unprotecting/erasing/programming. Please only enable
4225 this option if you really know what you are doing.
4227 - CONFIG_SYS_RX_ETH_BUFFER:
4228 Defines the number of Ethernet receive buffers. On some
4229 Ethernet controllers it is recommended to set this value
4230 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4231 buffers can be full shortly after enabling the interface
4232 on high Ethernet traffic.
4233 Defaults to 4 if not defined.
4235 - CONFIG_ENV_MAX_ENTRIES
4237 Maximum number of entries in the hash table that is used
4238 internally to store the environment settings. The default
4239 setting is supposed to be generous and should work in most
4240 cases. This setting can be used to tune behaviour; see
4241 lib/hashtable.c for details.
4243 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4244 - CONFIG_ENV_FLAGS_LIST_STATIC
4245 Enable validation of the values given to environment variables when
4246 calling env set. Variables can be restricted to only decimal,
4247 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4248 the variables can also be restricted to IP address or MAC address.
4250 The format of the list is:
4251 type_attribute = [s|d|x|b|i|m]
4252 access_attribute = [a|r|o|c]
4253 attributes = type_attribute[access_attribute]
4254 entry = variable_name[:attributes]
4257 The type attributes are:
4258 s - String (default)
4261 b - Boolean ([1yYtT|0nNfF])
4265 The access attributes are:
4271 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4272 Define this to a list (string) to define the ".flags"
4273 environment variable in the default or embedded environment.
4275 - CONFIG_ENV_FLAGS_LIST_STATIC
4276 Define this to a list (string) to define validation that
4277 should be done if an entry is not found in the ".flags"
4278 environment variable. To override a setting in the static
4279 list, simply add an entry for the same variable name to the
4282 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4283 If defined, don't allow the -f switch to env set override variable
4286 - CONFIG_SYS_GENERIC_BOARD
4287 This selects the architecture-generic board system instead of the
4288 architecture-specific board files. It is intended to move boards
4289 to this new framework over time. Defining this will disable the
4290 arch/foo/lib/board.c file and use common/board_f.c and
4291 common/board_r.c instead. To use this option your architecture
4292 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4293 its config.mk file). If you find problems enabling this option on
4294 your board please report the problem and send patches!
4296 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4297 This is set by OMAP boards for the max time that reset should
4298 be asserted. See doc/README.omap-reset-time for details on how
4299 the value can be calculated on a given board.
4302 If stdint.h is available with your toolchain you can define this
4303 option to enable it. You can provide option 'USE_STDINT=1' when
4304 building U-Boot to enable this.
4306 The following definitions that deal with the placement and management
4307 of environment data (variable area); in general, we support the
4308 following configurations:
4310 - CONFIG_BUILD_ENVCRC:
4312 Builds up envcrc with the target environment so that external utils
4313 may easily extract it and embed it in final U-Boot images.
4315 - CONFIG_ENV_IS_IN_FLASH:
4317 Define this if the environment is in flash memory.
4319 a) The environment occupies one whole flash sector, which is
4320 "embedded" in the text segment with the U-Boot code. This
4321 happens usually with "bottom boot sector" or "top boot
4322 sector" type flash chips, which have several smaller
4323 sectors at the start or the end. For instance, such a
4324 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4325 such a case you would place the environment in one of the
4326 4 kB sectors - with U-Boot code before and after it. With
4327 "top boot sector" type flash chips, you would put the
4328 environment in one of the last sectors, leaving a gap
4329 between U-Boot and the environment.
4331 - CONFIG_ENV_OFFSET:
4333 Offset of environment data (variable area) to the
4334 beginning of flash memory; for instance, with bottom boot
4335 type flash chips the second sector can be used: the offset
4336 for this sector is given here.
4338 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4342 This is just another way to specify the start address of
4343 the flash sector containing the environment (instead of
4346 - CONFIG_ENV_SECT_SIZE:
4348 Size of the sector containing the environment.
4351 b) Sometimes flash chips have few, equal sized, BIG sectors.
4352 In such a case you don't want to spend a whole sector for
4357 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4358 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4359 of this flash sector for the environment. This saves
4360 memory for the RAM copy of the environment.
4362 It may also save flash memory if you decide to use this
4363 when your environment is "embedded" within U-Boot code,
4364 since then the remainder of the flash sector could be used
4365 for U-Boot code. It should be pointed out that this is
4366 STRONGLY DISCOURAGED from a robustness point of view:
4367 updating the environment in flash makes it always
4368 necessary to erase the WHOLE sector. If something goes
4369 wrong before the contents has been restored from a copy in
4370 RAM, your target system will be dead.
4372 - CONFIG_ENV_ADDR_REDUND
4373 CONFIG_ENV_SIZE_REDUND
4375 These settings describe a second storage area used to hold
4376 a redundant copy of the environment data, so that there is
4377 a valid backup copy in case there is a power failure during
4378 a "saveenv" operation.
4380 BE CAREFUL! Any changes to the flash layout, and some changes to the
4381 source code will make it necessary to adapt <board>/u-boot.lds*
4385 - CONFIG_ENV_IS_IN_NVRAM:
4387 Define this if you have some non-volatile memory device
4388 (NVRAM, battery buffered SRAM) which you want to use for the
4394 These two #defines are used to determine the memory area you
4395 want to use for environment. It is assumed that this memory
4396 can just be read and written to, without any special
4399 BE CAREFUL! The first access to the environment happens quite early
4400 in U-Boot initialization (when we try to get the setting of for the
4401 console baudrate). You *MUST* have mapped your NVRAM area then, or
4404 Please note that even with NVRAM we still use a copy of the
4405 environment in RAM: we could work on NVRAM directly, but we want to
4406 keep settings there always unmodified except somebody uses "saveenv"
4407 to save the current settings.
4410 - CONFIG_ENV_IS_IN_EEPROM:
4412 Use this if you have an EEPROM or similar serial access
4413 device and a driver for it.
4415 - CONFIG_ENV_OFFSET:
4418 These two #defines specify the offset and size of the
4419 environment area within the total memory of your EEPROM.
4421 - CONFIG_SYS_I2C_EEPROM_ADDR:
4422 If defined, specified the chip address of the EEPROM device.
4423 The default address is zero.
4425 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4426 If defined, the number of bits used to address bytes in a
4427 single page in the EEPROM device. A 64 byte page, for example
4428 would require six bits.
4430 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4431 If defined, the number of milliseconds to delay between
4432 page writes. The default is zero milliseconds.
4434 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4435 The length in bytes of the EEPROM memory array address. Note
4436 that this is NOT the chip address length!
4438 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4439 EEPROM chips that implement "address overflow" are ones
4440 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4441 address and the extra bits end up in the "chip address" bit
4442 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4445 Note that we consider the length of the address field to
4446 still be one byte because the extra address bits are hidden
4447 in the chip address.
4449 - CONFIG_SYS_EEPROM_SIZE:
4450 The size in bytes of the EEPROM device.
4452 - CONFIG_ENV_EEPROM_IS_ON_I2C
4453 define this, if you have I2C and SPI activated, and your
4454 EEPROM, which holds the environment, is on the I2C bus.
4456 - CONFIG_I2C_ENV_EEPROM_BUS
4457 if you have an Environment on an EEPROM reached over
4458 I2C muxes, you can define here, how to reach this
4459 EEPROM. For example:
4461 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4463 EEPROM which holds the environment, is reached over
4464 a pca9547 i2c mux with address 0x70, channel 3.
4466 - CONFIG_ENV_IS_IN_DATAFLASH:
4468 Define this if you have a DataFlash memory device which you
4469 want to use for the environment.
4471 - CONFIG_ENV_OFFSET:
4475 These three #defines specify the offset and size of the
4476 environment area within the total memory of your DataFlash placed
4477 at the specified address.
4479 - CONFIG_ENV_IS_IN_SPI_FLASH:
4481 Define this if you have a SPI Flash memory device which you
4482 want to use for the environment.
4484 - CONFIG_ENV_OFFSET:
4487 These two #defines specify the offset and size of the
4488 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4489 aligned to an erase sector boundary.
4491 - CONFIG_ENV_SECT_SIZE:
4493 Define the SPI flash's sector size.
4495 - CONFIG_ENV_OFFSET_REDUND (optional):
4497 This setting describes a second storage area of CONFIG_ENV_SIZE
4498 size used to hold a redundant copy of the environment data, so
4499 that there is a valid backup copy in case there is a power failure
4500 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4501 aligned to an erase sector boundary.
4503 - CONFIG_ENV_SPI_BUS (optional):
4504 - CONFIG_ENV_SPI_CS (optional):
4506 Define the SPI bus and chip select. If not defined they will be 0.
4508 - CONFIG_ENV_SPI_MAX_HZ (optional):
4510 Define the SPI max work clock. If not defined then use 1MHz.
4512 - CONFIG_ENV_SPI_MODE (optional):
4514 Define the SPI work mode. If not defined then use SPI_MODE_3.
4516 - CONFIG_ENV_IS_IN_REMOTE:
4518 Define this if you have a remote memory space which you
4519 want to use for the local device's environment.
4524 These two #defines specify the address and size of the
4525 environment area within the remote memory space. The
4526 local device can get the environment from remote memory
4527 space by SRIO or PCIE links.
4529 BE CAREFUL! For some special cases, the local device can not use
4530 "saveenv" command. For example, the local device will get the
4531 environment stored in a remote NOR flash by SRIO or PCIE link,
4532 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4534 - CONFIG_ENV_IS_IN_NAND:
4536 Define this if you have a NAND device which you want to use
4537 for the environment.
4539 - CONFIG_ENV_OFFSET:
4542 These two #defines specify the offset and size of the environment
4543 area within the first NAND device. CONFIG_ENV_OFFSET must be
4544 aligned to an erase block boundary.
4546 - CONFIG_ENV_OFFSET_REDUND (optional):
4548 This setting describes a second storage area of CONFIG_ENV_SIZE
4549 size used to hold a redundant copy of the environment data, so
4550 that there is a valid backup copy in case there is a power failure
4551 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4552 aligned to an erase block boundary.
4554 - CONFIG_ENV_RANGE (optional):
4556 Specifies the length of the region in which the environment
4557 can be written. This should be a multiple of the NAND device's
4558 block size. Specifying a range with more erase blocks than
4559 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4560 the range to be avoided.
4562 - CONFIG_ENV_OFFSET_OOB (optional):
4564 Enables support for dynamically retrieving the offset of the
4565 environment from block zero's out-of-band data. The
4566 "nand env.oob" command can be used to record this offset.
4567 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4568 using CONFIG_ENV_OFFSET_OOB.
4570 - CONFIG_NAND_ENV_DST
4572 Defines address in RAM to which the nand_spl code should copy the
4573 environment. If redundant environment is used, it will be copied to
4574 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4576 - CONFIG_ENV_IS_IN_UBI:
4578 Define this if you have an UBI volume that you want to use for the
4579 environment. This has the benefit of wear-leveling the environment
4580 accesses, which is important on NAND.
4582 - CONFIG_ENV_UBI_PART:
4584 Define this to a string that is the mtd partition containing the UBI.
4586 - CONFIG_ENV_UBI_VOLUME:
4588 Define this to the name of the volume that you want to store the
4591 - CONFIG_ENV_UBI_VOLUME_REDUND:
4593 Define this to the name of another volume to store a second copy of
4594 the environment in. This will enable redundant environments in UBI.
4595 It is assumed that both volumes are in the same MTD partition.
4597 - CONFIG_UBI_SILENCE_MSG
4598 - CONFIG_UBIFS_SILENCE_MSG
4600 You will probably want to define these to avoid a really noisy system
4601 when storing the env in UBI.
4603 - CONFIG_ENV_IS_IN_FAT:
4604 Define this if you want to use the FAT file system for the environment.
4606 - FAT_ENV_INTERFACE:
4608 Define this to a string that is the name of the block device.
4610 - FAT_ENV_DEV_AND_PART:
4612 Define this to a string to specify the partition of the device. It can
4615 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4616 - "D:P": device D partition P. Error occurs if device D has no
4619 - "D" or "D:": device D partition 1 if device D has partition
4620 table, or the whole device D if has no partition
4622 - "D:auto": first partition in device D with bootable flag set.
4623 If none, first valid partition in device D. If no
4624 partition table then means device D.
4628 It's a string of the FAT file name. This file use to store the
4632 This should be defined. Otherwise it cannot save the environment file.
4634 - CONFIG_ENV_IS_IN_MMC:
4636 Define this if you have an MMC device which you want to use for the
4639 - CONFIG_SYS_MMC_ENV_DEV:
4641 Specifies which MMC device the environment is stored in.
4643 - CONFIG_SYS_MMC_ENV_PART (optional):
4645 Specifies which MMC partition the environment is stored in. If not
4646 set, defaults to partition 0, the user area. Common values might be
4647 1 (first MMC boot partition), 2 (second MMC boot partition).
4649 - CONFIG_ENV_OFFSET:
4652 These two #defines specify the offset and size of the environment
4653 area within the specified MMC device.
4655 If offset is positive (the usual case), it is treated as relative to
4656 the start of the MMC partition. If offset is negative, it is treated
4657 as relative to the end of the MMC partition. This can be useful if
4658 your board may be fitted with different MMC devices, which have
4659 different sizes for the MMC partitions, and you always want the
4660 environment placed at the very end of the partition, to leave the
4661 maximum possible space before it, to store other data.
4663 These two values are in units of bytes, but must be aligned to an
4664 MMC sector boundary.
4666 - CONFIG_ENV_OFFSET_REDUND (optional):
4668 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4669 hold a redundant copy of the environment data. This provides a
4670 valid backup copy in case the other copy is corrupted, e.g. due
4671 to a power failure during a "saveenv" operation.
4673 This value may also be positive or negative; this is handled in the
4674 same way as CONFIG_ENV_OFFSET.
4676 This value is also in units of bytes, but must also be aligned to
4677 an MMC sector boundary.
4679 - CONFIG_ENV_SIZE_REDUND (optional):
4681 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4682 set. If this value is set, it must be set to the same value as
4685 - CONFIG_SYS_SPI_INIT_OFFSET
4687 Defines offset to the initial SPI buffer area in DPRAM. The
4688 area is used at an early stage (ROM part) if the environment
4689 is configured to reside in the SPI EEPROM: We need a 520 byte
4690 scratch DPRAM area. It is used between the two initialization
4691 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4692 to be a good choice since it makes it far enough from the
4693 start of the data area as well as from the stack pointer.
4695 Please note that the environment is read-only until the monitor
4696 has been relocated to RAM and a RAM copy of the environment has been
4697 created; also, when using EEPROM you will have to use getenv_f()
4698 until then to read environment variables.
4700 The environment is protected by a CRC32 checksum. Before the monitor
4701 is relocated into RAM, as a result of a bad CRC you will be working
4702 with the compiled-in default environment - *silently*!!! [This is
4703 necessary, because the first environment variable we need is the
4704 "baudrate" setting for the console - if we have a bad CRC, we don't
4705 have any device yet where we could complain.]
4707 Note: once the monitor has been relocated, then it will complain if
4708 the default environment is used; a new CRC is computed as soon as you
4709 use the "saveenv" command to store a valid environment.
4711 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4712 Echo the inverted Ethernet link state to the fault LED.
4714 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4715 also needs to be defined.
4717 - CONFIG_SYS_FAULT_MII_ADDR:
4718 MII address of the PHY to check for the Ethernet link state.
4720 - CONFIG_NS16550_MIN_FUNCTIONS:
4721 Define this if you desire to only have use of the NS16550_init
4722 and NS16550_putc functions for the serial driver located at
4723 drivers/serial/ns16550.c. This option is useful for saving
4724 space for already greatly restricted images, including but not
4725 limited to NAND_SPL configurations.
4727 - CONFIG_DISPLAY_BOARDINFO
4728 Display information about the board that U-Boot is running on
4729 when U-Boot starts up. The board function checkboard() is called
4732 - CONFIG_DISPLAY_BOARDINFO_LATE
4733 Similar to the previous option, but display this information
4734 later, once stdio is running and output goes to the LCD, if
4737 - CONFIG_BOARD_SIZE_LIMIT:
4738 Maximum size of the U-Boot image. When defined, the
4739 build system checks that the actual size does not
4742 Low Level (hardware related) configuration options:
4743 ---------------------------------------------------
4745 - CONFIG_SYS_CACHELINE_SIZE:
4746 Cache Line Size of the CPU.
4748 - CONFIG_SYS_DEFAULT_IMMR:
4749 Default address of the IMMR after system reset.
4751 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4752 and RPXsuper) to be able to adjust the position of
4753 the IMMR register after a reset.
4755 - CONFIG_SYS_CCSRBAR_DEFAULT:
4756 Default (power-on reset) physical address of CCSR on Freescale
4759 - CONFIG_SYS_CCSRBAR:
4760 Virtual address of CCSR. On a 32-bit build, this is typically
4761 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4763 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4764 for cross-platform code that uses that macro instead.
4766 - CONFIG_SYS_CCSRBAR_PHYS:
4767 Physical address of CCSR. CCSR can be relocated to a new
4768 physical address, if desired. In this case, this macro should
4769 be set to that address. Otherwise, it should be set to the
4770 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4771 is typically relocated on 36-bit builds. It is recommended
4772 that this macro be defined via the _HIGH and _LOW macros:
4774 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4775 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4777 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4778 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4779 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4780 used in assembly code, so it must not contain typecasts or
4781 integer size suffixes (e.g. "ULL").
4783 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4784 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4785 used in assembly code, so it must not contain typecasts or
4786 integer size suffixes (e.g. "ULL").
4788 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4789 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4790 forced to a value that ensures that CCSR is not relocated.
4792 - Floppy Disk Support:
4793 CONFIG_SYS_FDC_DRIVE_NUMBER
4795 the default drive number (default value 0)
4797 CONFIG_SYS_ISA_IO_STRIDE
4799 defines the spacing between FDC chipset registers
4802 CONFIG_SYS_ISA_IO_OFFSET
4804 defines the offset of register from address. It
4805 depends on which part of the data bus is connected to
4806 the FDC chipset. (default value 0)
4808 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4809 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4812 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4813 fdc_hw_init() is called at the beginning of the FDC
4814 setup. fdc_hw_init() must be provided by the board
4815 source code. It is used to make hardware-dependent
4819 Most IDE controllers were designed to be connected with PCI
4820 interface. Only few of them were designed for AHB interface.
4821 When software is doing ATA command and data transfer to
4822 IDE devices through IDE-AHB controller, some additional
4823 registers accessing to these kind of IDE-AHB controller
4826 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4827 DO NOT CHANGE unless you know exactly what you're
4828 doing! (11-4) [MPC8xx/82xx systems only]
4830 - CONFIG_SYS_INIT_RAM_ADDR:
4832 Start address of memory area that can be used for
4833 initial data and stack; please note that this must be
4834 writable memory that is working WITHOUT special
4835 initialization, i. e. you CANNOT use normal RAM which
4836 will become available only after programming the
4837 memory controller and running certain initialization
4840 U-Boot uses the following memory types:
4841 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4842 - MPC824X: data cache
4843 - PPC4xx: data cache
4845 - CONFIG_SYS_GBL_DATA_OFFSET:
4847 Offset of the initial data structure in the memory
4848 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4849 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4850 data is located at the end of the available space
4851 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4852 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4853 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4854 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4857 On the MPC824X (or other systems that use the data
4858 cache for initial memory) the address chosen for
4859 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4860 point to an otherwise UNUSED address space between
4861 the top of RAM and the start of the PCI space.
4863 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4865 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4867 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4869 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4871 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4873 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4875 - CONFIG_SYS_OR_TIMING_SDRAM:
4878 - CONFIG_SYS_MAMR_PTA:
4879 periodic timer for refresh
4881 - CONFIG_SYS_DER: Debug Event Register (37-47)
4883 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4884 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4885 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4886 CONFIG_SYS_BR1_PRELIM:
4887 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4889 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4890 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4891 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4892 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4894 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4895 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4896 Machine Mode Register and Memory Periodic Timer
4897 Prescaler definitions (SDRAM timing)
4899 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4900 enable I2C microcode relocation patch (MPC8xx);
4901 define relocation offset in DPRAM [DSP2]
4903 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4904 enable SMC microcode relocation patch (MPC8xx);
4905 define relocation offset in DPRAM [SMC1]
4907 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4908 enable SPI microcode relocation patch (MPC8xx);
4909 define relocation offset in DPRAM [SCC4]
4911 - CONFIG_SYS_USE_OSCCLK:
4912 Use OSCM clock mode on MBX8xx board. Be careful,
4913 wrong setting might damage your board. Read
4914 doc/README.MBX before setting this variable!
4916 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4917 Offset of the bootmode word in DPRAM used by post
4918 (Power On Self Tests). This definition overrides
4919 #define'd default value in commproc.h resp.
4922 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4923 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4924 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4925 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4926 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4927 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4928 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4929 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4930 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4932 - CONFIG_PCI_DISABLE_PCIE:
4933 Disable PCI-Express on systems where it is supported but not
4936 - CONFIG_PCI_ENUM_ONLY
4937 Only scan through and get the devices on the buses.
4938 Don't do any setup work, presumably because someone or
4939 something has already done it, and we don't need to do it
4940 a second time. Useful for platforms that are pre-booted
4941 by coreboot or similar.
4943 - CONFIG_PCI_INDIRECT_BRIDGE:
4944 Enable support for indirect PCI bridges.
4947 Chip has SRIO or not
4950 Board has SRIO 1 port available
4953 Board has SRIO 2 port available
4955 - CONFIG_SRIO_PCIE_BOOT_MASTER
4956 Board can support master function for Boot from SRIO and PCIE
4958 - CONFIG_SYS_SRIOn_MEM_VIRT:
4959 Virtual Address of SRIO port 'n' memory region
4961 - CONFIG_SYS_SRIOn_MEM_PHYS:
4962 Physical Address of SRIO port 'n' memory region
4964 - CONFIG_SYS_SRIOn_MEM_SIZE:
4965 Size of SRIO port 'n' memory region
4967 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4968 Defined to tell the NAND controller that the NAND chip is using
4970 Not all NAND drivers use this symbol.
4971 Example of drivers that use it:
4972 - drivers/mtd/nand/ndfc.c
4973 - drivers/mtd/nand/mxc_nand.c
4975 - CONFIG_SYS_NDFC_EBC0_CFG
4976 Sets the EBC0_CFG register for the NDFC. If not defined
4977 a default value will be used.
4980 Get DDR timing information from an I2C EEPROM. Common
4981 with pluggable memory modules such as SODIMMs
4984 I2C address of the SPD EEPROM
4986 - CONFIG_SYS_SPD_BUS_NUM
4987 If SPD EEPROM is on an I2C bus other than the first
4988 one, specify here. Note that the value must resolve
4989 to something your driver can deal with.
4991 - CONFIG_SYS_DDR_RAW_TIMING
4992 Get DDR timing information from other than SPD. Common with
4993 soldered DDR chips onboard without SPD. DDR raw timing
4994 parameters are extracted from datasheet and hard-coded into
4995 header files or board specific files.
4997 - CONFIG_FSL_DDR_INTERACTIVE
4998 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5000 - CONFIG_FSL_DDR_SYNC_REFRESH
5001 Enable sync of refresh for multiple controllers.
5003 - CONFIG_SYS_83XX_DDR_USES_CS0
5004 Only for 83xx systems. If specified, then DDR should
5005 be configured using CS0 and CS1 instead of CS2 and CS3.
5007 - CONFIG_ETHER_ON_FEC[12]
5008 Define to enable FEC[12] on a 8xx series processor.
5010 - CONFIG_FEC[12]_PHY
5011 Define to the hardcoded PHY address which corresponds
5012 to the given FEC; i. e.
5013 #define CONFIG_FEC1_PHY 4
5014 means that the PHY with address 4 is connected to FEC1
5016 When set to -1, means to probe for first available.
5018 - CONFIG_FEC[12]_PHY_NORXERR
5019 The PHY does not have a RXERR line (RMII only).
5020 (so program the FEC to ignore it).
5023 Enable RMII mode for all FECs.
5024 Note that this is a global option, we can't
5025 have one FEC in standard MII mode and another in RMII mode.
5027 - CONFIG_CRC32_VERIFY
5028 Add a verify option to the crc32 command.
5031 => crc32 -v <address> <count> <crc32>
5033 Where address/count indicate a memory area
5034 and crc32 is the correct crc32 which the
5038 Add the "loopw" memory command. This only takes effect if
5039 the memory commands are activated globally (CONFIG_CMD_MEM).
5042 Add the "mdc" and "mwc" memory commands. These are cyclic
5047 This command will print 4 bytes (10,11,12,13) each 500 ms.
5049 => mwc.l 100 12345678 10
5050 This command will write 12345678 to address 100 all 10 ms.
5052 This only takes effect if the memory commands are activated
5053 globally (CONFIG_CMD_MEM).
5055 - CONFIG_SKIP_LOWLEVEL_INIT
5056 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5057 low level initializations (like setting up the memory
5058 controller) are omitted and/or U-Boot does not
5059 relocate itself into RAM.
5061 Normally this variable MUST NOT be defined. The only
5062 exception is when U-Boot is loaded (to RAM) by some
5063 other boot loader or by a debugger which performs
5064 these initializations itself.
5067 Modifies the behaviour of start.S when compiling a loader
5068 that is executed before the actual U-Boot. E.g. when
5069 compiling a NAND SPL.
5072 Modifies the behaviour of start.S when compiling a loader
5073 that is executed after the SPL and before the actual U-Boot.
5074 It is loaded by the SPL.
5076 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5077 Only for 85xx systems. If this variable is specified, the section
5078 .resetvec is not kept and the section .bootpg is placed in the
5079 previous 4k of the .text section.
5081 - CONFIG_ARCH_MAP_SYSMEM
5082 Generally U-Boot (and in particular the md command) uses
5083 effective address. It is therefore not necessary to regard
5084 U-Boot address as virtual addresses that need to be translated
5085 to physical addresses. However, sandbox requires this, since
5086 it maintains its own little RAM buffer which contains all
5087 addressable memory. This option causes some memory accesses
5088 to be mapped through map_sysmem() / unmap_sysmem().
5090 - CONFIG_USE_ARCH_MEMCPY
5091 CONFIG_USE_ARCH_MEMSET
5092 If these options are used a optimized version of memcpy/memset will
5093 be used if available. These functions may be faster under some
5094 conditions but may increase the binary size.
5096 - CONFIG_X86_RESET_VECTOR
5097 If defined, the x86 reset vector code is included. This is not
5098 needed when U-Boot is running from Coreboot.
5101 Defines the MPU clock speed (in MHz).
5103 NOTE : currently only supported on AM335x platforms.
5105 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5106 Enables the RTC32K OSC on AM33xx based plattforms
5108 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5109 Option to disable subpage write in NAND driver
5110 driver that uses this:
5111 drivers/mtd/nand/davinci_nand.c
5113 Freescale QE/FMAN Firmware Support:
5114 -----------------------------------
5116 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5117 loading of "firmware", which is encoded in the QE firmware binary format.
5118 This firmware often needs to be loaded during U-Boot booting, so macros
5119 are used to identify the storage device (NOR flash, SPI, etc) and the address
5122 - CONFIG_SYS_FMAN_FW_ADDR
5123 The address in the storage device where the FMAN microcode is located. The
5124 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5127 - CONFIG_SYS_QE_FW_ADDR
5128 The address in the storage device where the QE microcode is located. The
5129 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5132 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5133 The maximum possible size of the firmware. The firmware binary format
5134 has a field that specifies the actual size of the firmware, but it
5135 might not be possible to read any part of the firmware unless some
5136 local storage is allocated to hold the entire firmware first.
5138 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5139 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5140 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5141 virtual address in NOR flash.
5143 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5144 Specifies that QE/FMAN firmware is located in NAND flash.
5145 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5147 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5148 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5149 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5151 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5152 Specifies that QE/FMAN firmware is located on the primary SPI
5153 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5155 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5156 Specifies that QE/FMAN firmware is located in the remote (master)
5157 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5158 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5159 window->master inbound window->master LAW->the ucode address in
5160 master's memory space.
5162 Freescale Layerscape Management Complex Firmware Support:
5163 ---------------------------------------------------------
5164 The Freescale Layerscape Management Complex (MC) supports the loading of
5166 This firmware often needs to be loaded during U-Boot booting, so macros
5167 are used to identify the storage device (NOR flash, SPI, etc) and the address
5170 - CONFIG_FSL_MC_ENET
5171 Enable the MC driver for Layerscape SoCs.
5173 - CONFIG_SYS_LS_MC_FW_ADDR
5174 The address in the storage device where the firmware is located. The
5175 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5178 - CONFIG_SYS_LS_MC_FW_LENGTH
5179 The maximum possible size of the firmware. The firmware binary format
5180 has a field that specifies the actual size of the firmware, but it
5181 might not be possible to read any part of the firmware unless some
5182 local storage is allocated to hold the entire firmware first.
5184 - CONFIG_SYS_LS_MC_FW_IN_NOR
5185 Specifies that MC firmware is located in NOR flash, mapped as
5186 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5187 virtual address in NOR flash.
5189 Building the Software:
5190 ======================
5192 Building U-Boot has been tested in several native build environments
5193 and in many different cross environments. Of course we cannot support
5194 all possibly existing versions of cross development tools in all
5195 (potentially obsolete) versions. In case of tool chain problems we
5196 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5197 which is extensively used to build and test U-Boot.
5199 If you are not using a native environment, it is assumed that you
5200 have GNU cross compiling tools available in your path. In this case,
5201 you must set the environment variable CROSS_COMPILE in your shell.
5202 Note that no changes to the Makefile or any other source files are
5203 necessary. For example using the ELDK on a 4xx CPU, please enter:
5205 $ CROSS_COMPILE=ppc_4xx-
5206 $ export CROSS_COMPILE
5208 Note: If you wish to generate Windows versions of the utilities in
5209 the tools directory you can use the MinGW toolchain
5210 (http://www.mingw.org). Set your HOST tools to the MinGW
5211 toolchain and execute 'make tools'. For example:
5213 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5215 Binaries such as tools/mkimage.exe will be created which can
5216 be executed on computers running Windows.
5218 U-Boot is intended to be simple to build. After installing the
5219 sources you must configure U-Boot for one specific board type. This
5224 where "NAME_defconfig" is the name of one of the existing configu-
5225 rations; see boards.cfg for supported names.
5227 Note: for some board special configuration names may exist; check if
5228 additional information is available from the board vendor; for
5229 instance, the TQM823L systems are available without (standard)
5230 or with LCD support. You can select such additional "features"
5231 when choosing the configuration, i. e.
5233 make TQM823L_defconfig
5234 - will configure for a plain TQM823L, i. e. no LCD support
5236 make TQM823L_LCD_defconfig
5237 - will configure for a TQM823L with U-Boot console on LCD
5242 Finally, type "make all", and you should get some working U-Boot
5243 images ready for download to / installation on your system:
5245 - "u-boot.bin" is a raw binary image
5246 - "u-boot" is an image in ELF binary format
5247 - "u-boot.srec" is in Motorola S-Record format
5249 By default the build is performed locally and the objects are saved
5250 in the source directory. One of the two methods can be used to change
5251 this behavior and build U-Boot to some external directory:
5253 1. Add O= to the make command line invocations:
5255 make O=/tmp/build distclean
5256 make O=/tmp/build NAME_defconfig
5257 make O=/tmp/build all
5259 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5261 export KBUILD_OUTPUT=/tmp/build
5266 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5270 Please be aware that the Makefiles assume you are using GNU make, so
5271 for instance on NetBSD you might need to use "gmake" instead of
5275 If the system board that you have is not listed, then you will need
5276 to port U-Boot to your hardware platform. To do this, follow these
5279 1. Add a new configuration option for your board to the toplevel
5280 "boards.cfg" file, using the existing entries as examples.
5281 Follow the instructions there to keep the boards in order.
5282 2. Create a new directory to hold your board specific code. Add any
5283 files you need. In your board directory, you will need at least
5284 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5285 3. Create a new configuration file "include/configs/<board>.h" for
5287 3. If you're porting U-Boot to a new CPU, then also create a new
5288 directory to hold your CPU specific code. Add any files you need.
5289 4. Run "make <board>_defconfig" with your new name.
5290 5. Type "make", and you should get a working "u-boot.srec" file
5291 to be installed on your target system.
5292 6. Debug and solve any problems that might arise.
5293 [Of course, this last step is much harder than it sounds.]
5296 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5297 ==============================================================
5299 If you have modified U-Boot sources (for instance added a new board
5300 or support for new devices, a new CPU, etc.) you are expected to
5301 provide feedback to the other developers. The feedback normally takes
5302 the form of a "patch", i. e. a context diff against a certain (latest
5303 official or latest in the git repository) version of U-Boot sources.
5305 But before you submit such a patch, please verify that your modifi-
5306 cation did not break existing code. At least make sure that *ALL* of
5307 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5308 just run the "MAKEALL" script, which will configure and build U-Boot
5309 for ALL supported system. Be warned, this will take a while. You can
5310 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5311 environment variable to the script, i. e. to use the ELDK cross tools
5314 CROSS_COMPILE=ppc_8xx- MAKEALL
5316 or to build on a native PowerPC system you can type
5318 CROSS_COMPILE=' ' MAKEALL
5320 When using the MAKEALL script, the default behaviour is to build
5321 U-Boot in the source directory. This location can be changed by
5322 setting the BUILD_DIR environment variable. Also, for each target
5323 built, the MAKEALL script saves two log files (<target>.ERR and
5324 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5325 location can be changed by setting the MAKEALL_LOGDIR environment
5326 variable. For example:
5328 export BUILD_DIR=/tmp/build
5329 export MAKEALL_LOGDIR=/tmp/log
5330 CROSS_COMPILE=ppc_8xx- MAKEALL
5332 With the above settings build objects are saved in the /tmp/build,
5333 log files are saved in the /tmp/log and the source tree remains clean
5334 during the whole build process.
5337 See also "U-Boot Porting Guide" below.
5340 Monitor Commands - Overview:
5341 ============================
5343 go - start application at address 'addr'
5344 run - run commands in an environment variable
5345 bootm - boot application image from memory
5346 bootp - boot image via network using BootP/TFTP protocol
5347 bootz - boot zImage from memory
5348 tftpboot- boot image via network using TFTP protocol
5349 and env variables "ipaddr" and "serverip"
5350 (and eventually "gatewayip")
5351 tftpput - upload a file via network using TFTP protocol
5352 rarpboot- boot image via network using RARP/TFTP protocol
5353 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5354 loads - load S-Record file over serial line
5355 loadb - load binary file over serial line (kermit mode)
5357 mm - memory modify (auto-incrementing)
5358 nm - memory modify (constant address)
5359 mw - memory write (fill)
5361 cmp - memory compare
5362 crc32 - checksum calculation
5363 i2c - I2C sub-system
5364 sspi - SPI utility commands
5365 base - print or set address offset
5366 printenv- print environment variables
5367 setenv - set environment variables
5368 saveenv - save environment variables to persistent storage
5369 protect - enable or disable FLASH write protection
5370 erase - erase FLASH memory
5371 flinfo - print FLASH memory information
5372 nand - NAND memory operations (see doc/README.nand)
5373 bdinfo - print Board Info structure
5374 iminfo - print header information for application image
5375 coninfo - print console devices and informations
5376 ide - IDE sub-system
5377 loop - infinite loop on address range
5378 loopw - infinite write loop on address range
5379 mtest - simple RAM test
5380 icache - enable or disable instruction cache
5381 dcache - enable or disable data cache
5382 reset - Perform RESET of the CPU
5383 echo - echo args to console
5384 version - print monitor version
5385 help - print online help
5386 ? - alias for 'help'
5389 Monitor Commands - Detailed Description:
5390 ========================================
5394 For now: just type "help <command>".
5397 Environment Variables:
5398 ======================
5400 U-Boot supports user configuration using Environment Variables which
5401 can be made persistent by saving to Flash memory.
5403 Environment Variables are set using "setenv", printed using
5404 "printenv", and saved to Flash using "saveenv". Using "setenv"
5405 without a value can be used to delete a variable from the
5406 environment. As long as you don't save the environment you are
5407 working with an in-memory copy. In case the Flash area containing the
5408 environment is erased by accident, a default environment is provided.
5410 Some configuration options can be set using Environment Variables.
5412 List of environment variables (most likely not complete):
5414 baudrate - see CONFIG_BAUDRATE
5416 bootdelay - see CONFIG_BOOTDELAY
5418 bootcmd - see CONFIG_BOOTCOMMAND
5420 bootargs - Boot arguments when booting an RTOS image
5422 bootfile - Name of the image to load with TFTP
5424 bootm_low - Memory range available for image processing in the bootm
5425 command can be restricted. This variable is given as
5426 a hexadecimal number and defines lowest address allowed
5427 for use by the bootm command. See also "bootm_size"
5428 environment variable. Address defined by "bootm_low" is
5429 also the base of the initial memory mapping for the Linux
5430 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5433 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5434 This variable is given as a hexadecimal number and it
5435 defines the size of the memory region starting at base
5436 address bootm_low that is accessible by the Linux kernel
5437 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5438 as the default value if it is defined, and bootm_size is
5441 bootm_size - Memory range available for image processing in the bootm
5442 command can be restricted. This variable is given as
5443 a hexadecimal number and defines the size of the region
5444 allowed for use by the bootm command. See also "bootm_low"
5445 environment variable.
5447 updatefile - Location of the software update file on a TFTP server, used
5448 by the automatic software update feature. Please refer to
5449 documentation in doc/README.update for more details.
5451 autoload - if set to "no" (any string beginning with 'n'),
5452 "bootp" will just load perform a lookup of the
5453 configuration from the BOOTP server, but not try to
5454 load any image using TFTP
5456 autostart - if set to "yes", an image loaded using the "bootp",
5457 "rarpboot", "tftpboot" or "diskboot" commands will
5458 be automatically started (by internally calling
5461 If set to "no", a standalone image passed to the
5462 "bootm" command will be copied to the load address
5463 (and eventually uncompressed), but NOT be started.
5464 This can be used to load and uncompress arbitrary
5467 fdt_high - if set this restricts the maximum address that the
5468 flattened device tree will be copied into upon boot.
5469 For example, if you have a system with 1 GB memory
5470 at physical address 0x10000000, while Linux kernel
5471 only recognizes the first 704 MB as low memory, you
5472 may need to set fdt_high as 0x3C000000 to have the
5473 device tree blob be copied to the maximum address
5474 of the 704 MB low memory, so that Linux kernel can
5475 access it during the boot procedure.
5477 If this is set to the special value 0xFFFFFFFF then
5478 the fdt will not be copied at all on boot. For this
5479 to work it must reside in writable memory, have
5480 sufficient padding on the end of it for u-boot to
5481 add the information it needs into it, and the memory
5482 must be accessible by the kernel.
5484 fdtcontroladdr- if set this is the address of the control flattened
5485 device tree used by U-Boot when CONFIG_OF_CONTROL is
5488 i2cfast - (PPC405GP|PPC405EP only)
5489 if set to 'y' configures Linux I2C driver for fast
5490 mode (400kHZ). This environment variable is used in
5491 initialization code. So, for changes to be effective
5492 it must be saved and board must be reset.
5494 initrd_high - restrict positioning of initrd images:
5495 If this variable is not set, initrd images will be
5496 copied to the highest possible address in RAM; this
5497 is usually what you want since it allows for
5498 maximum initrd size. If for some reason you want to
5499 make sure that the initrd image is loaded below the
5500 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5501 variable to a value of "no" or "off" or "0".
5502 Alternatively, you can set it to a maximum upper
5503 address to use (U-Boot will still check that it
5504 does not overwrite the U-Boot stack and data).
5506 For instance, when you have a system with 16 MB
5507 RAM, and want to reserve 4 MB from use by Linux,
5508 you can do this by adding "mem=12M" to the value of
5509 the "bootargs" variable. However, now you must make
5510 sure that the initrd image is placed in the first
5511 12 MB as well - this can be done with
5513 setenv initrd_high 00c00000
5515 If you set initrd_high to 0xFFFFFFFF, this is an
5516 indication to U-Boot that all addresses are legal
5517 for the Linux kernel, including addresses in flash
5518 memory. In this case U-Boot will NOT COPY the
5519 ramdisk at all. This may be useful to reduce the
5520 boot time on your system, but requires that this
5521 feature is supported by your Linux kernel.
5523 ipaddr - IP address; needed for tftpboot command
5525 loadaddr - Default load address for commands like "bootp",
5526 "rarpboot", "tftpboot", "loadb" or "diskboot"
5528 loads_echo - see CONFIG_LOADS_ECHO
5530 serverip - TFTP server IP address; needed for tftpboot command
5532 bootretry - see CONFIG_BOOT_RETRY_TIME
5534 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5536 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5538 ethprime - controls which interface is used first.
5540 ethact - controls which interface is currently active.
5541 For example you can do the following
5543 => setenv ethact FEC
5544 => ping 192.168.0.1 # traffic sent on FEC
5545 => setenv ethact SCC
5546 => ping 10.0.0.1 # traffic sent on SCC
5548 ethrotate - When set to "no" U-Boot does not go through all
5549 available network interfaces.
5550 It just stays at the currently selected interface.
5552 netretry - When set to "no" each network operation will
5553 either succeed or fail without retrying.
5554 When set to "once" the network operation will
5555 fail when all the available network interfaces
5556 are tried once without success.
5557 Useful on scripts which control the retry operation
5560 npe_ucode - set load address for the NPE microcode
5562 silent_linux - If set then Linux will be told to boot silently, by
5563 changing the console to be empty. If "yes" it will be
5564 made silent. If "no" it will not be made silent. If
5565 unset, then it will be made silent if the U-Boot console
5568 tftpsrcport - If this is set, the value is used for TFTP's
5571 tftpdstport - If this is set, the value is used for TFTP's UDP
5572 destination port instead of the Well Know Port 69.
5574 tftpblocksize - Block size to use for TFTP transfers; if not set,
5575 we use the TFTP server's default block size
5577 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5578 seconds, minimum value is 1000 = 1 second). Defines
5579 when a packet is considered to be lost so it has to
5580 be retransmitted. The default is 5000 = 5 seconds.
5581 Lowering this value may make downloads succeed
5582 faster in networks with high packet loss rates or
5583 with unreliable TFTP servers.
5585 vlan - When set to a value < 4095 the traffic over
5586 Ethernet is encapsulated/received over 802.1q
5589 The following image location variables contain the location of images
5590 used in booting. The "Image" column gives the role of the image and is
5591 not an environment variable name. The other columns are environment
5592 variable names. "File Name" gives the name of the file on a TFTP
5593 server, "RAM Address" gives the location in RAM the image will be
5594 loaded to, and "Flash Location" gives the image's address in NOR
5595 flash or offset in NAND flash.
5597 *Note* - these variables don't have to be defined for all boards, some
5598 boards currenlty use other variables for these purposes, and some
5599 boards use these variables for other purposes.
5601 Image File Name RAM Address Flash Location
5602 ----- --------- ----------- --------------
5603 u-boot u-boot u-boot_addr_r u-boot_addr
5604 Linux kernel bootfile kernel_addr_r kernel_addr
5605 device tree blob fdtfile fdt_addr_r fdt_addr
5606 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5608 The following environment variables may be used and automatically
5609 updated by the network boot commands ("bootp" and "rarpboot"),
5610 depending the information provided by your boot server:
5612 bootfile - see above
5613 dnsip - IP address of your Domain Name Server
5614 dnsip2 - IP address of your secondary Domain Name Server
5615 gatewayip - IP address of the Gateway (Router) to use
5616 hostname - Target hostname
5618 netmask - Subnet Mask
5619 rootpath - Pathname of the root filesystem on the NFS server
5620 serverip - see above
5623 There are two special Environment Variables:
5625 serial# - contains hardware identification information such
5626 as type string and/or serial number
5627 ethaddr - Ethernet address
5629 These variables can be set only once (usually during manufacturing of
5630 the board). U-Boot refuses to delete or overwrite these variables
5631 once they have been set once.
5634 Further special Environment Variables:
5636 ver - Contains the U-Boot version string as printed
5637 with the "version" command. This variable is
5638 readonly (see CONFIG_VERSION_VARIABLE).
5641 Please note that changes to some configuration parameters may take
5642 only effect after the next boot (yes, that's just like Windoze :-).
5645 Callback functions for environment variables:
5646 ---------------------------------------------
5648 For some environment variables, the behavior of u-boot needs to change
5649 when their values are changed. This functionality allows functions to
5650 be associated with arbitrary variables. On creation, overwrite, or
5651 deletion, the callback will provide the opportunity for some side
5652 effect to happen or for the change to be rejected.
5654 The callbacks are named and associated with a function using the
5655 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5657 These callbacks are associated with variables in one of two ways. The
5658 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5659 in the board configuration to a string that defines a list of
5660 associations. The list must be in the following format:
5662 entry = variable_name[:callback_name]
5665 If the callback name is not specified, then the callback is deleted.
5666 Spaces are also allowed anywhere in the list.
5668 Callbacks can also be associated by defining the ".callbacks" variable
5669 with the same list format above. Any association in ".callbacks" will
5670 override any association in the static list. You can define
5671 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5672 ".callbacks" environment variable in the default or embedded environment.
5675 Command Line Parsing:
5676 =====================
5678 There are two different command line parsers available with U-Boot:
5679 the old "simple" one, and the much more powerful "hush" shell:
5681 Old, simple command line parser:
5682 --------------------------------
5684 - supports environment variables (through setenv / saveenv commands)
5685 - several commands on one line, separated by ';'
5686 - variable substitution using "... ${name} ..." syntax
5687 - special characters ('$', ';') can be escaped by prefixing with '\',
5689 setenv bootcmd bootm \${address}
5690 - You can also escape text by enclosing in single apostrophes, for example:
5691 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5696 - similar to Bourne shell, with control structures like
5697 if...then...else...fi, for...do...done; while...do...done,
5698 until...do...done, ...
5699 - supports environment ("global") variables (through setenv / saveenv
5700 commands) and local shell variables (through standard shell syntax
5701 "name=value"); only environment variables can be used with "run"
5707 (1) If a command line (or an environment variable executed by a "run"
5708 command) contains several commands separated by semicolon, and
5709 one of these commands fails, then the remaining commands will be
5712 (2) If you execute several variables with one call to run (i. e.
5713 calling run with a list of variables as arguments), any failing
5714 command will cause "run" to terminate, i. e. the remaining
5715 variables are not executed.
5717 Note for Redundant Ethernet Interfaces:
5718 =======================================
5720 Some boards come with redundant Ethernet interfaces; U-Boot supports
5721 such configurations and is capable of automatic selection of a
5722 "working" interface when needed. MAC assignment works as follows:
5724 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5725 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5726 "eth1addr" (=>eth1), "eth2addr", ...
5728 If the network interface stores some valid MAC address (for instance
5729 in SROM), this is used as default address if there is NO correspon-
5730 ding setting in the environment; if the corresponding environment
5731 variable is set, this overrides the settings in the card; that means:
5733 o If the SROM has a valid MAC address, and there is no address in the
5734 environment, the SROM's address is used.
5736 o If there is no valid address in the SROM, and a definition in the
5737 environment exists, then the value from the environment variable is
5740 o If both the SROM and the environment contain a MAC address, and
5741 both addresses are the same, this MAC address is used.
5743 o If both the SROM and the environment contain a MAC address, and the
5744 addresses differ, the value from the environment is used and a
5747 o If neither SROM nor the environment contain a MAC address, an error
5750 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5751 will be programmed into hardware as part of the initialization process. This
5752 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5753 The naming convention is as follows:
5754 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5759 U-Boot is capable of booting (and performing other auxiliary operations on)
5760 images in two formats:
5762 New uImage format (FIT)
5763 -----------------------
5765 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5766 to Flattened Device Tree). It allows the use of images with multiple
5767 components (several kernels, ramdisks, etc.), with contents protected by
5768 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5774 Old image format is based on binary files which can be basically anything,
5775 preceded by a special header; see the definitions in include/image.h for
5776 details; basically, the header defines the following image properties:
5778 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5779 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5780 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5781 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5783 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5784 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5785 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5786 * Compression Type (uncompressed, gzip, bzip2)
5792 The header is marked by a special Magic Number, and both the header
5793 and the data portions of the image are secured against corruption by
5800 Although U-Boot should support any OS or standalone application
5801 easily, the main focus has always been on Linux during the design of
5804 U-Boot includes many features that so far have been part of some
5805 special "boot loader" code within the Linux kernel. Also, any
5806 "initrd" images to be used are no longer part of one big Linux image;
5807 instead, kernel and "initrd" are separate images. This implementation
5808 serves several purposes:
5810 - the same features can be used for other OS or standalone
5811 applications (for instance: using compressed images to reduce the
5812 Flash memory footprint)
5814 - it becomes much easier to port new Linux kernel versions because
5815 lots of low-level, hardware dependent stuff are done by U-Boot
5817 - the same Linux kernel image can now be used with different "initrd"
5818 images; of course this also means that different kernel images can
5819 be run with the same "initrd". This makes testing easier (you don't
5820 have to build a new "zImage.initrd" Linux image when you just
5821 change a file in your "initrd"). Also, a field-upgrade of the
5822 software is easier now.
5828 Porting Linux to U-Boot based systems:
5829 ---------------------------------------
5831 U-Boot cannot save you from doing all the necessary modifications to
5832 configure the Linux device drivers for use with your target hardware
5833 (no, we don't intend to provide a full virtual machine interface to
5836 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5838 Just make sure your machine specific header file (for instance
5839 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5840 Information structure as we define in include/asm-<arch>/u-boot.h,
5841 and make sure that your definition of IMAP_ADDR uses the same value
5842 as your U-Boot configuration in CONFIG_SYS_IMMR.
5844 Note that U-Boot now has a driver model, a unified model for drivers.
5845 If you are adding a new driver, plumb it into driver model. If there
5846 is no uclass available, you are encouraged to create one. See
5850 Configuring the Linux kernel:
5851 -----------------------------
5853 No specific requirements for U-Boot. Make sure you have some root
5854 device (initial ramdisk, NFS) for your target system.
5857 Building a Linux Image:
5858 -----------------------
5860 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5861 not used. If you use recent kernel source, a new build target
5862 "uImage" will exist which automatically builds an image usable by
5863 U-Boot. Most older kernels also have support for a "pImage" target,
5864 which was introduced for our predecessor project PPCBoot and uses a
5865 100% compatible format.
5869 make TQM850L_defconfig
5874 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5875 encapsulate a compressed Linux kernel image with header information,
5876 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5878 * build a standard "vmlinux" kernel image (in ELF binary format):
5880 * convert the kernel into a raw binary image:
5882 ${CROSS_COMPILE}-objcopy -O binary \
5883 -R .note -R .comment \
5884 -S vmlinux linux.bin
5886 * compress the binary image:
5890 * package compressed binary image for U-Boot:
5892 mkimage -A ppc -O linux -T kernel -C gzip \
5893 -a 0 -e 0 -n "Linux Kernel Image" \
5894 -d linux.bin.gz uImage
5897 The "mkimage" tool can also be used to create ramdisk images for use
5898 with U-Boot, either separated from the Linux kernel image, or
5899 combined into one file. "mkimage" encapsulates the images with a 64
5900 byte header containing information about target architecture,
5901 operating system, image type, compression method, entry points, time
5902 stamp, CRC32 checksums, etc.
5904 "mkimage" can be called in two ways: to verify existing images and
5905 print the header information, or to build new images.
5907 In the first form (with "-l" option) mkimage lists the information
5908 contained in the header of an existing U-Boot image; this includes
5909 checksum verification:
5911 tools/mkimage -l image
5912 -l ==> list image header information
5914 The second form (with "-d" option) is used to build a U-Boot image
5915 from a "data file" which is used as image payload:
5917 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5918 -n name -d data_file image
5919 -A ==> set architecture to 'arch'
5920 -O ==> set operating system to 'os'
5921 -T ==> set image type to 'type'
5922 -C ==> set compression type 'comp'
5923 -a ==> set load address to 'addr' (hex)
5924 -e ==> set entry point to 'ep' (hex)
5925 -n ==> set image name to 'name'
5926 -d ==> use image data from 'datafile'
5928 Right now, all Linux kernels for PowerPC systems use the same load
5929 address (0x00000000), but the entry point address depends on the
5932 - 2.2.x kernels have the entry point at 0x0000000C,
5933 - 2.3.x and later kernels have the entry point at 0x00000000.
5935 So a typical call to build a U-Boot image would read:
5937 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5938 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5939 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5940 > examples/uImage.TQM850L
5941 Image Name: 2.4.4 kernel for TQM850L
5942 Created: Wed Jul 19 02:34:59 2000
5943 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5944 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5945 Load Address: 0x00000000
5946 Entry Point: 0x00000000
5948 To verify the contents of the image (or check for corruption):
5950 -> tools/mkimage -l examples/uImage.TQM850L
5951 Image Name: 2.4.4 kernel for TQM850L
5952 Created: Wed Jul 19 02:34:59 2000
5953 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5954 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5955 Load Address: 0x00000000
5956 Entry Point: 0x00000000
5958 NOTE: for embedded systems where boot time is critical you can trade
5959 speed for memory and install an UNCOMPRESSED image instead: this
5960 needs more space in Flash, but boots much faster since it does not
5961 need to be uncompressed:
5963 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5964 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5965 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5966 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5967 > examples/uImage.TQM850L-uncompressed
5968 Image Name: 2.4.4 kernel for TQM850L
5969 Created: Wed Jul 19 02:34:59 2000
5970 Image Type: PowerPC Linux Kernel Image (uncompressed)
5971 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5972 Load Address: 0x00000000
5973 Entry Point: 0x00000000
5976 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5977 when your kernel is intended to use an initial ramdisk:
5979 -> tools/mkimage -n 'Simple Ramdisk Image' \
5980 > -A ppc -O linux -T ramdisk -C gzip \
5981 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5982 Image Name: Simple Ramdisk Image
5983 Created: Wed Jan 12 14:01:50 2000
5984 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5985 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5986 Load Address: 0x00000000
5987 Entry Point: 0x00000000
5989 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5990 option performs the converse operation of the mkimage's second form (the "-d"
5991 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5994 tools/dumpimage -i image -T type -p position data_file
5995 -i ==> extract from the 'image' a specific 'data_file'
5996 -T ==> set image type to 'type'
5997 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6000 Installing a Linux Image:
6001 -------------------------
6003 To downloading a U-Boot image over the serial (console) interface,
6004 you must convert the image to S-Record format:
6006 objcopy -I binary -O srec examples/image examples/image.srec
6008 The 'objcopy' does not understand the information in the U-Boot
6009 image header, so the resulting S-Record file will be relative to
6010 address 0x00000000. To load it to a given address, you need to
6011 specify the target address as 'offset' parameter with the 'loads'
6014 Example: install the image to address 0x40100000 (which on the
6015 TQM8xxL is in the first Flash bank):
6017 => erase 40100000 401FFFFF
6023 ## Ready for S-Record download ...
6024 ~>examples/image.srec
6025 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6027 15989 15990 15991 15992
6028 [file transfer complete]
6030 ## Start Addr = 0x00000000
6033 You can check the success of the download using the 'iminfo' command;
6034 this includes a checksum verification so you can be sure no data
6035 corruption happened:
6039 ## Checking Image at 40100000 ...
6040 Image Name: 2.2.13 for initrd on TQM850L
6041 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6042 Data Size: 335725 Bytes = 327 kB = 0 MB
6043 Load Address: 00000000
6044 Entry Point: 0000000c
6045 Verifying Checksum ... OK
6051 The "bootm" command is used to boot an application that is stored in
6052 memory (RAM or Flash). In case of a Linux kernel image, the contents
6053 of the "bootargs" environment variable is passed to the kernel as
6054 parameters. You can check and modify this variable using the
6055 "printenv" and "setenv" commands:
6058 => printenv bootargs
6059 bootargs=root=/dev/ram
6061 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6063 => printenv bootargs
6064 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6067 ## Booting Linux kernel at 40020000 ...
6068 Image Name: 2.2.13 for NFS on TQM850L
6069 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6070 Data Size: 381681 Bytes = 372 kB = 0 MB
6071 Load Address: 00000000
6072 Entry Point: 0000000c
6073 Verifying Checksum ... OK
6074 Uncompressing Kernel Image ... OK
6075 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
6076 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6077 time_init: decrementer frequency = 187500000/60
6078 Calibrating delay loop... 49.77 BogoMIPS
6079 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6082 If you want to boot a Linux kernel with initial RAM disk, you pass
6083 the memory addresses of both the kernel and the initrd image (PPBCOOT
6084 format!) to the "bootm" command:
6086 => imi 40100000 40200000
6088 ## Checking Image at 40100000 ...
6089 Image Name: 2.2.13 for initrd on TQM850L
6090 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6091 Data Size: 335725 Bytes = 327 kB = 0 MB
6092 Load Address: 00000000
6093 Entry Point: 0000000c
6094 Verifying Checksum ... OK
6096 ## Checking Image at 40200000 ...
6097 Image Name: Simple Ramdisk Image
6098 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6099 Data Size: 566530 Bytes = 553 kB = 0 MB
6100 Load Address: 00000000
6101 Entry Point: 00000000
6102 Verifying Checksum ... OK
6104 => bootm 40100000 40200000
6105 ## Booting Linux kernel at 40100000 ...
6106 Image Name: 2.2.13 for initrd on TQM850L
6107 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6108 Data Size: 335725 Bytes = 327 kB = 0 MB
6109 Load Address: 00000000
6110 Entry Point: 0000000c
6111 Verifying Checksum ... OK
6112 Uncompressing Kernel Image ... OK
6113 ## Loading RAMDisk Image at 40200000 ...
6114 Image Name: Simple Ramdisk Image
6115 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6116 Data Size: 566530 Bytes = 553 kB = 0 MB
6117 Load Address: 00000000
6118 Entry Point: 00000000
6119 Verifying Checksum ... OK
6120 Loading Ramdisk ... OK
6121 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
6122 Boot arguments: root=/dev/ram
6123 time_init: decrementer frequency = 187500000/60
6124 Calibrating delay loop... 49.77 BogoMIPS
6126 RAMDISK: Compressed image found at block 0
6127 VFS: Mounted root (ext2 filesystem).
6131 Boot Linux and pass a flat device tree:
6134 First, U-Boot must be compiled with the appropriate defines. See the section
6135 titled "Linux Kernel Interface" above for a more in depth explanation. The
6136 following is an example of how to start a kernel and pass an updated
6142 oft=oftrees/mpc8540ads.dtb
6143 => tftp $oftaddr $oft
6144 Speed: 1000, full duplex
6146 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6147 Filename 'oftrees/mpc8540ads.dtb'.
6148 Load address: 0x300000
6151 Bytes transferred = 4106 (100a hex)
6152 => tftp $loadaddr $bootfile
6153 Speed: 1000, full duplex
6155 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6157 Load address: 0x200000
6158 Loading:############
6160 Bytes transferred = 1029407 (fb51f hex)
6165 => bootm $loadaddr - $oftaddr
6166 ## Booting image at 00200000 ...
6167 Image Name: Linux-2.6.17-dirty
6168 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6169 Data Size: 1029343 Bytes = 1005.2 kB
6170 Load Address: 00000000
6171 Entry Point: 00000000
6172 Verifying Checksum ... OK
6173 Uncompressing Kernel Image ... OK
6174 Booting using flat device tree at 0x300000
6175 Using MPC85xx ADS machine description
6176 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6180 More About U-Boot Image Types:
6181 ------------------------------
6183 U-Boot supports the following image types:
6185 "Standalone Programs" are directly runnable in the environment
6186 provided by U-Boot; it is expected that (if they behave
6187 well) you can continue to work in U-Boot after return from
6188 the Standalone Program.
6189 "OS Kernel Images" are usually images of some Embedded OS which
6190 will take over control completely. Usually these programs
6191 will install their own set of exception handlers, device
6192 drivers, set up the MMU, etc. - this means, that you cannot
6193 expect to re-enter U-Boot except by resetting the CPU.
6194 "RAMDisk Images" are more or less just data blocks, and their
6195 parameters (address, size) are passed to an OS kernel that is
6197 "Multi-File Images" contain several images, typically an OS
6198 (Linux) kernel image and one or more data images like
6199 RAMDisks. This construct is useful for instance when you want
6200 to boot over the network using BOOTP etc., where the boot
6201 server provides just a single image file, but you want to get
6202 for instance an OS kernel and a RAMDisk image.
6204 "Multi-File Images" start with a list of image sizes, each
6205 image size (in bytes) specified by an "uint32_t" in network
6206 byte order. This list is terminated by an "(uint32_t)0".
6207 Immediately after the terminating 0 follow the images, one by
6208 one, all aligned on "uint32_t" boundaries (size rounded up to
6209 a multiple of 4 bytes).
6211 "Firmware Images" are binary images containing firmware (like
6212 U-Boot or FPGA images) which usually will be programmed to
6215 "Script files" are command sequences that will be executed by
6216 U-Boot's command interpreter; this feature is especially
6217 useful when you configure U-Boot to use a real shell (hush)
6218 as command interpreter.
6220 Booting the Linux zImage:
6221 -------------------------
6223 On some platforms, it's possible to boot Linux zImage. This is done
6224 using the "bootz" command. The syntax of "bootz" command is the same
6225 as the syntax of "bootm" command.
6227 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6228 kernel with raw initrd images. The syntax is slightly different, the
6229 address of the initrd must be augmented by it's size, in the following
6230 format: "<initrd addres>:<initrd size>".
6236 One of the features of U-Boot is that you can dynamically load and
6237 run "standalone" applications, which can use some resources of
6238 U-Boot like console I/O functions or interrupt services.
6240 Two simple examples are included with the sources:
6245 'examples/hello_world.c' contains a small "Hello World" Demo
6246 application; it is automatically compiled when you build U-Boot.
6247 It's configured to run at address 0x00040004, so you can play with it
6251 ## Ready for S-Record download ...
6252 ~>examples/hello_world.srec
6253 1 2 3 4 5 6 7 8 9 10 11 ...
6254 [file transfer complete]
6256 ## Start Addr = 0x00040004
6258 => go 40004 Hello World! This is a test.
6259 ## Starting application at 0x00040004 ...
6270 Hit any key to exit ...
6272 ## Application terminated, rc = 0x0
6274 Another example, which demonstrates how to register a CPM interrupt
6275 handler with the U-Boot code, can be found in 'examples/timer.c'.
6276 Here, a CPM timer is set up to generate an interrupt every second.
6277 The interrupt service routine is trivial, just printing a '.'
6278 character, but this is just a demo program. The application can be
6279 controlled by the following keys:
6281 ? - print current values og the CPM Timer registers
6282 b - enable interrupts and start timer
6283 e - stop timer and disable interrupts
6284 q - quit application
6287 ## Ready for S-Record download ...
6288 ~>examples/timer.srec
6289 1 2 3 4 5 6 7 8 9 10 11 ...
6290 [file transfer complete]
6292 ## Start Addr = 0x00040004
6295 ## Starting application at 0x00040004 ...
6298 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6301 [q, b, e, ?] Set interval 1000000 us
6304 [q, b, e, ?] ........
6305 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6308 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6311 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6314 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6316 [q, b, e, ?] ...Stopping timer
6318 [q, b, e, ?] ## Application terminated, rc = 0x0
6324 Over time, many people have reported problems when trying to use the
6325 "minicom" terminal emulation program for serial download. I (wd)
6326 consider minicom to be broken, and recommend not to use it. Under
6327 Unix, I recommend to use C-Kermit for general purpose use (and
6328 especially for kermit binary protocol download ("loadb" command), and
6329 use "cu" for S-Record download ("loads" command). See
6330 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6331 for help with kermit.
6334 Nevertheless, if you absolutely want to use it try adding this
6335 configuration to your "File transfer protocols" section:
6337 Name Program Name U/D FullScr IO-Red. Multi
6338 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6339 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6345 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6346 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6348 Building requires a cross environment; it is known to work on
6349 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6350 need gmake since the Makefiles are not compatible with BSD make).
6351 Note that the cross-powerpc package does not install include files;
6352 attempting to build U-Boot will fail because <machine/ansi.h> is
6353 missing. This file has to be installed and patched manually:
6355 # cd /usr/pkg/cross/powerpc-netbsd/include
6357 # ln -s powerpc machine
6358 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6359 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6361 Native builds *don't* work due to incompatibilities between native
6362 and U-Boot include files.
6364 Booting assumes that (the first part of) the image booted is a
6365 stage-2 loader which in turn loads and then invokes the kernel
6366 proper. Loader sources will eventually appear in the NetBSD source
6367 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6368 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6371 Implementation Internals:
6372 =========================
6374 The following is not intended to be a complete description of every
6375 implementation detail. However, it should help to understand the
6376 inner workings of U-Boot and make it easier to port it to custom
6380 Initial Stack, Global Data:
6381 ---------------------------
6383 The implementation of U-Boot is complicated by the fact that U-Boot
6384 starts running out of ROM (flash memory), usually without access to
6385 system RAM (because the memory controller is not initialized yet).
6386 This means that we don't have writable Data or BSS segments, and BSS
6387 is not initialized as zero. To be able to get a C environment working
6388 at all, we have to allocate at least a minimal stack. Implementation
6389 options for this are defined and restricted by the CPU used: Some CPU
6390 models provide on-chip memory (like the IMMR area on MPC8xx and
6391 MPC826x processors), on others (parts of) the data cache can be
6392 locked as (mis-) used as memory, etc.
6394 Chris Hallinan posted a good summary of these issues to the
6395 U-Boot mailing list:
6397 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6398 From: "Chris Hallinan" <clh@net1plus.com>
6399 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6402 Correct me if I'm wrong, folks, but the way I understand it
6403 is this: Using DCACHE as initial RAM for Stack, etc, does not
6404 require any physical RAM backing up the cache. The cleverness
6405 is that the cache is being used as a temporary supply of
6406 necessary storage before the SDRAM controller is setup. It's
6407 beyond the scope of this list to explain the details, but you
6408 can see how this works by studying the cache architecture and
6409 operation in the architecture and processor-specific manuals.
6411 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6412 is another option for the system designer to use as an
6413 initial stack/RAM area prior to SDRAM being available. Either
6414 option should work for you. Using CS 4 should be fine if your
6415 board designers haven't used it for something that would
6416 cause you grief during the initial boot! It is frequently not
6419 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6420 with your processor/board/system design. The default value
6421 you will find in any recent u-boot distribution in
6422 walnut.h should work for you. I'd set it to a value larger
6423 than your SDRAM module. If you have a 64MB SDRAM module, set
6424 it above 400_0000. Just make sure your board has no resources
6425 that are supposed to respond to that address! That code in
6426 start.S has been around a while and should work as is when
6427 you get the config right.
6432 It is essential to remember this, since it has some impact on the C
6433 code for the initialization procedures:
6435 * Initialized global data (data segment) is read-only. Do not attempt
6438 * Do not use any uninitialized global data (or implicitly initialized
6439 as zero data - BSS segment) at all - this is undefined, initiali-
6440 zation is performed later (when relocating to RAM).
6442 * Stack space is very limited. Avoid big data buffers or things like
6445 Having only the stack as writable memory limits means we cannot use
6446 normal global data to share information between the code. But it
6447 turned out that the implementation of U-Boot can be greatly
6448 simplified by making a global data structure (gd_t) available to all
6449 functions. We could pass a pointer to this data as argument to _all_
6450 functions, but this would bloat the code. Instead we use a feature of
6451 the GCC compiler (Global Register Variables) to share the data: we
6452 place a pointer (gd) to the global data into a register which we
6453 reserve for this purpose.
6455 When choosing a register for such a purpose we are restricted by the
6456 relevant (E)ABI specifications for the current architecture, and by
6457 GCC's implementation.
6459 For PowerPC, the following registers have specific use:
6461 R2: reserved for system use
6462 R3-R4: parameter passing and return values
6463 R5-R10: parameter passing
6464 R13: small data area pointer
6468 (U-Boot also uses R12 as internal GOT pointer. r12
6469 is a volatile register so r12 needs to be reset when
6470 going back and forth between asm and C)
6472 ==> U-Boot will use R2 to hold a pointer to the global data
6474 Note: on PPC, we could use a static initializer (since the
6475 address of the global data structure is known at compile time),
6476 but it turned out that reserving a register results in somewhat
6477 smaller code - although the code savings are not that big (on
6478 average for all boards 752 bytes for the whole U-Boot image,
6479 624 text + 127 data).
6481 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6482 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6484 ==> U-Boot will use P3 to hold a pointer to the global data
6486 On ARM, the following registers are used:
6488 R0: function argument word/integer result
6489 R1-R3: function argument word
6490 R9: platform specific
6491 R10: stack limit (used only if stack checking is enabled)
6492 R11: argument (frame) pointer
6493 R12: temporary workspace
6496 R15: program counter
6498 ==> U-Boot will use R9 to hold a pointer to the global data
6500 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6502 On Nios II, the ABI is documented here:
6503 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6505 ==> U-Boot will use gp to hold a pointer to the global data
6507 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6508 to access small data sections, so gp is free.
6510 On NDS32, the following registers are used:
6512 R0-R1: argument/return
6514 R15: temporary register for assembler
6515 R16: trampoline register
6516 R28: frame pointer (FP)
6517 R29: global pointer (GP)
6518 R30: link register (LP)
6519 R31: stack pointer (SP)
6520 PC: program counter (PC)
6522 ==> U-Boot will use R10 to hold a pointer to the global data
6524 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6525 or current versions of GCC may "optimize" the code too much.
6530 U-Boot runs in system state and uses physical addresses, i.e. the
6531 MMU is not used either for address mapping nor for memory protection.
6533 The available memory is mapped to fixed addresses using the memory
6534 controller. In this process, a contiguous block is formed for each
6535 memory type (Flash, SDRAM, SRAM), even when it consists of several
6536 physical memory banks.
6538 U-Boot is installed in the first 128 kB of the first Flash bank (on
6539 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6540 booting and sizing and initializing DRAM, the code relocates itself
6541 to the upper end of DRAM. Immediately below the U-Boot code some
6542 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6543 configuration setting]. Below that, a structure with global Board
6544 Info data is placed, followed by the stack (growing downward).
6546 Additionally, some exception handler code is copied to the low 8 kB
6547 of DRAM (0x00000000 ... 0x00001FFF).
6549 So a typical memory configuration with 16 MB of DRAM could look like
6552 0x0000 0000 Exception Vector code
6555 0x0000 2000 Free for Application Use
6561 0x00FB FF20 Monitor Stack (Growing downward)
6562 0x00FB FFAC Board Info Data and permanent copy of global data
6563 0x00FC 0000 Malloc Arena
6566 0x00FE 0000 RAM Copy of Monitor Code
6567 ... eventually: LCD or video framebuffer
6568 ... eventually: pRAM (Protected RAM - unchanged by reset)
6569 0x00FF FFFF [End of RAM]
6572 System Initialization:
6573 ----------------------
6575 In the reset configuration, U-Boot starts at the reset entry point
6576 (on most PowerPC systems at address 0x00000100). Because of the reset
6577 configuration for CS0# this is a mirror of the on board Flash memory.
6578 To be able to re-map memory U-Boot then jumps to its link address.
6579 To be able to implement the initialization code in C, a (small!)
6580 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6581 which provide such a feature like MPC8xx or MPC8260), or in a locked
6582 part of the data cache. After that, U-Boot initializes the CPU core,
6583 the caches and the SIU.
6585 Next, all (potentially) available memory banks are mapped using a
6586 preliminary mapping. For example, we put them on 512 MB boundaries
6587 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6588 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6589 programmed for SDRAM access. Using the temporary configuration, a
6590 simple memory test is run that determines the size of the SDRAM
6593 When there is more than one SDRAM bank, and the banks are of
6594 different size, the largest is mapped first. For equal size, the first
6595 bank (CS2#) is mapped first. The first mapping is always for address
6596 0x00000000, with any additional banks following immediately to create
6597 contiguous memory starting from 0.
6599 Then, the monitor installs itself at the upper end of the SDRAM area
6600 and allocates memory for use by malloc() and for the global Board
6601 Info data; also, the exception vector code is copied to the low RAM
6602 pages, and the final stack is set up.
6604 Only after this relocation will you have a "normal" C environment;
6605 until that you are restricted in several ways, mostly because you are
6606 running from ROM, and because the code will have to be relocated to a
6610 U-Boot Porting Guide:
6611 ----------------------
6613 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6617 int main(int argc, char *argv[])
6619 sighandler_t no_more_time;
6621 signal(SIGALRM, no_more_time);
6622 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6624 if (available_money > available_manpower) {
6625 Pay consultant to port U-Boot;
6629 Download latest U-Boot source;
6631 Subscribe to u-boot mailing list;
6634 email("Hi, I am new to U-Boot, how do I get started?");
6637 Read the README file in the top level directory;
6638 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6639 Read applicable doc/*.README;
6640 Read the source, Luke;
6641 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6644 if (available_money > toLocalCurrency ($2500))
6647 Add a lot of aggravation and time;
6649 if (a similar board exists) { /* hopefully... */
6650 cp -a board/<similar> board/<myboard>
6651 cp include/configs/<similar>.h include/configs/<myboard>.h
6653 Create your own board support subdirectory;
6654 Create your own board include/configs/<myboard>.h file;
6656 Edit new board/<myboard> files
6657 Edit new include/configs/<myboard>.h
6662 Add / modify source code;
6666 email("Hi, I am having problems...");
6668 Send patch file to the U-Boot email list;
6669 if (reasonable critiques)
6670 Incorporate improvements from email list code review;
6672 Defend code as written;
6678 void no_more_time (int sig)
6687 All contributions to U-Boot should conform to the Linux kernel
6688 coding style; see the file "Documentation/CodingStyle" and the script
6689 "scripts/Lindent" in your Linux kernel source directory.
6691 Source files originating from a different project (for example the
6692 MTD subsystem) are generally exempt from these guidelines and are not
6693 reformatted to ease subsequent migration to newer versions of those
6696 Please note that U-Boot is implemented in C (and to some small parts in
6697 Assembler); no C++ is used, so please do not use C++ style comments (//)
6700 Please also stick to the following formatting rules:
6701 - remove any trailing white space
6702 - use TAB characters for indentation and vertical alignment, not spaces
6703 - make sure NOT to use DOS '\r\n' line feeds
6704 - do not add more than 2 consecutive empty lines to source files
6705 - do not add trailing empty lines to source files
6707 Submissions which do not conform to the standards may be returned
6708 with a request to reformat the changes.
6714 Since the number of patches for U-Boot is growing, we need to
6715 establish some rules. Submissions which do not conform to these rules
6716 may be rejected, even when they contain important and valuable stuff.
6718 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6720 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6721 see http://lists.denx.de/mailman/listinfo/u-boot
6723 When you send a patch, please include the following information with
6726 * For bug fixes: a description of the bug and how your patch fixes
6727 this bug. Please try to include a way of demonstrating that the
6728 patch actually fixes something.
6730 * For new features: a description of the feature and your
6733 * A CHANGELOG entry as plaintext (separate from the patch)
6735 * For major contributions, your entry to the CREDITS file
6737 * When you add support for a new board, don't forget to add a
6738 maintainer e-mail address to the boards.cfg file, too.
6740 * If your patch adds new configuration options, don't forget to
6741 document these in the README file.
6743 * The patch itself. If you are using git (which is *strongly*
6744 recommended) you can easily generate the patch using the
6745 "git format-patch". If you then use "git send-email" to send it to
6746 the U-Boot mailing list, you will avoid most of the common problems
6747 with some other mail clients.
6749 If you cannot use git, use "diff -purN OLD NEW". If your version of
6750 diff does not support these options, then get the latest version of
6753 The current directory when running this command shall be the parent
6754 directory of the U-Boot source tree (i. e. please make sure that
6755 your patch includes sufficient directory information for the
6758 We prefer patches as plain text. MIME attachments are discouraged,
6759 and compressed attachments must not be used.
6761 * If one logical set of modifications affects or creates several
6762 files, all these changes shall be submitted in a SINGLE patch file.
6764 * Changesets that contain different, unrelated modifications shall be
6765 submitted as SEPARATE patches, one patch per changeset.
6770 * Before sending the patch, run the MAKEALL script on your patched
6771 source tree and make sure that no errors or warnings are reported
6772 for any of the boards.
6774 * Keep your modifications to the necessary minimum: A patch
6775 containing several unrelated changes or arbitrary reformats will be
6776 returned with a request to re-formatting / split it.
6778 * If you modify existing code, make sure that your new code does not
6779 add to the memory footprint of the code ;-) Small is beautiful!
6780 When adding new features, these should compile conditionally only
6781 (using #ifdef), and the resulting code with the new feature
6782 disabled must not need more memory than the old code without your
6785 * Remember that there is a size limit of 100 kB per message on the
6786 u-boot mailing list. Bigger patches will be moderated. If they are
6787 reasonable and not too big, they will be acknowledged. But patches
6788 bigger than the size limit should be avoided.
projects / u-boot / blob