2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_798870
705 CONFIG_ARM_ERRATA_801819
708 CONFIG_TEGRA_SUPPORT_NON_SECURE
710 Support executing U-Boot in non-secure (NS) mode. Certain
711 impossible actions will be skipped if the CPU is in NS mode,
712 such as ARM architectural timer initialization.
715 Driver model is a new framework for devices in U-Boot
716 introduced in early 2014. U-Boot is being progressively
717 moved over to this. It offers a consistent device structure,
718 supports grouping devices into classes and has built-in
719 handling of platform data and device tree.
721 To enable transition to driver model in a relatively
722 painful fashion, each subsystem can be independently
723 switched between the legacy/ad-hoc approach and the new
724 driver model using the options below. Also, many uclass
725 interfaces include compatibility features which may be
726 removed once the conversion of that subsystem is complete.
727 As a result, the API provided by the subsystem may in fact
728 not change with driver model.
730 See doc/driver-model/README.txt for more information.
734 Enable driver model. This brings in the core support,
735 including scanning of platform data on start-up. If
736 CONFIG_OF_CONTROL is enabled, the device tree will be
737 scanned also when available.
741 Enable driver model test commands. These allow you to print
742 out the driver model tree and the uclasses.
746 Enable some demo devices and the 'demo' command. These are
747 really only useful for playing around while trying to
748 understand driver model in sandbox.
752 Enable driver model in SPL. You will need to provide a
753 suitable malloc() implementation. If you are not using the
754 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
755 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
756 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
757 In most cases driver model will only allocate a few uclasses
758 and devices in SPL, so 1KB should be enable. See
759 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
764 Enable driver model for serial. This replaces
765 drivers/serial/serial.c with the serial uclass, which
766 implements serial_putc() etc. The uclass interface is
767 defined in include/serial.h.
771 Enable driver model for GPIO access. The standard GPIO
772 interface (gpio_get_value(), etc.) is then implemented by
773 the GPIO uclass. Drivers provide methods to query the
774 particular GPIOs that they provide. The uclass interface
775 is defined in include/asm-generic/gpio.h.
779 Enable driver model for SPI. The SPI slave interface
780 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
781 the SPI uclass. Drivers provide methods to access the SPI
782 buses that they control. The uclass interface is defined in
783 include/spi.h. The existing spi_slave structure is attached
784 as 'parent data' to every slave on each bus. Slaves
785 typically use driver-private data instead of extending the
790 Enable driver model for SPI flash. This SPI flash interface
791 (spi_flash_probe(), spi_flash_write(), etc.) is then
792 implemented by the SPI flash uclass. There is one standard
793 SPI flash driver which knows how to probe most chips
794 supported by U-Boot. The uclass interface is defined in
795 include/spi_flash.h, but is currently fully compatible
796 with the old interface to avoid confusion and duplication
797 during the transition parent. SPI and SPI flash must be
798 enabled together (it is not possible to use driver model
799 for one and not the other).
803 Enable driver model for the Chrome OS EC interface. This
804 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
805 but otherwise makes few changes. Since cros_ec also supports
806 I2C and LPC (which don't support driver model yet), a full
807 conversion is not yet possible.
810 ** Code size options: The following options are enabled by
811 default except in SPL. Enable them explicitly to get these
816 Enable the dm_warn() function. This can use up quite a bit
817 of space for its strings.
821 Enable registering a serial device with the stdio library.
823 CONFIG_DM_DEVICE_REMOVE
825 Enable removing of devices.
827 - Linux Kernel Interface:
830 U-Boot stores all clock information in Hz
831 internally. For binary compatibility with older Linux
832 kernels (which expect the clocks passed in the
833 bd_info data to be in MHz) the environment variable
834 "clocks_in_mhz" can be defined so that U-Boot
835 converts clock data to MHZ before passing it to the
837 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
838 "clocks_in_mhz=1" is automatically included in the
841 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
843 When transferring memsize parameter to Linux, some versions
844 expect it to be in bytes, others in MB.
845 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
849 New kernel versions are expecting firmware settings to be
850 passed using flattened device trees (based on open firmware
854 * New libfdt-based support
855 * Adds the "fdt" command
856 * The bootm command automatically updates the fdt
858 OF_CPU - The proper name of the cpus node (only required for
859 MPC512X and MPC5xxx based boards).
860 OF_SOC - The proper name of the soc node (only required for
861 MPC512X and MPC5xxx based boards).
862 OF_TBCLK - The timebase frequency.
863 OF_STDOUT_PATH - The path to the console device
865 boards with QUICC Engines require OF_QE to set UCC MAC
868 CONFIG_OF_BOARD_SETUP
870 Board code has addition modification that it wants to make
871 to the flat device tree before handing it off to the kernel
873 CONFIG_OF_SYSTEM_SETUP
875 Other code has addition modification that it wants to make
876 to the flat device tree before handing it off to the kernel.
877 This causes ft_system_setup() to be called before booting
882 This define fills in the correct boot CPU in the boot
883 param header, the default value is zero if undefined.
887 U-Boot can detect if an IDE device is present or not.
888 If not, and this new config option is activated, U-Boot
889 removes the ATA node from the DTS before booting Linux,
890 so the Linux IDE driver does not probe the device and
891 crash. This is needed for buggy hardware (uc101) where
892 no pull down resistor is connected to the signal IDE5V_DD7.
894 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
896 This setting is mandatory for all boards that have only one
897 machine type and must be used to specify the machine type
898 number as it appears in the ARM machine registry
899 (see http://www.arm.linux.org.uk/developer/machines/).
900 Only boards that have multiple machine types supported
901 in a single configuration file and the machine type is
902 runtime discoverable, do not have to use this setting.
904 - vxWorks boot parameters:
906 bootvx constructs a valid bootline using the following
907 environments variables: bootfile, ipaddr, serverip, hostname.
908 It loads the vxWorks image pointed bootfile.
910 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
911 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
912 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
913 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
915 CONFIG_SYS_VXWORKS_ADD_PARAMS
917 Add it at the end of the bootline. E.g "u=username pw=secret"
919 Note: If a "bootargs" environment is defined, it will overwride
920 the defaults discussed just above.
922 - Cache Configuration:
923 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
924 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
925 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
927 - Cache Configuration for ARM:
928 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
930 CONFIG_SYS_PL310_BASE - Physical base address of PL310
931 controller register space
936 Define this if you want support for Amba PrimeCell PL010 UARTs.
940 Define this if you want support for Amba PrimeCell PL011 UARTs.
944 If you have Amba PrimeCell PL011 UARTs, set this variable to
945 the clock speed of the UARTs.
949 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
950 define this to a list of base addresses for each (supported)
951 port. See e.g. include/configs/versatile.h
953 CONFIG_PL011_SERIAL_RLCR
955 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
956 have separate receive and transmit line control registers. Set
957 this variable to initialize the extra register.
959 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
961 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
962 boot loader that has already initialized the UART. Define this
963 variable to flush the UART at init time.
965 CONFIG_SERIAL_HW_FLOW_CONTROL
967 Define this variable to enable hw flow control in serial driver.
968 Current user of this option is drivers/serial/nsl16550.c driver
971 Depending on board, define exactly one serial port
972 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
973 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
974 console by defining CONFIG_8xx_CONS_NONE
976 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
977 port routines must be defined elsewhere
978 (i.e. serial_init(), serial_getc(), ...)
981 Enables console device for a color framebuffer. Needs following
982 defines (cf. smiLynxEM, i8042)
983 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
985 VIDEO_HW_RECTFILL graphic chip supports
988 VIDEO_HW_BITBLT graphic chip supports
989 bit-blit (cf. smiLynxEM)
990 VIDEO_VISIBLE_COLS visible pixel columns
992 VIDEO_VISIBLE_ROWS visible pixel rows
993 VIDEO_PIXEL_SIZE bytes per pixel
994 VIDEO_DATA_FORMAT graphic data format
995 (0-5, cf. cfb_console.c)
996 VIDEO_FB_ADRS framebuffer address
997 VIDEO_KBD_INIT_FCT keyboard int fct
998 (i.e. i8042_kbd_init())
999 VIDEO_TSTC_FCT test char fct
1001 VIDEO_GETC_FCT get char fct
1003 CONFIG_CONSOLE_CURSOR cursor drawing on/off
1004 (requires blink timer
1006 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1007 CONFIG_CONSOLE_TIME display time/date info in
1009 (requires CONFIG_CMD_DATE)
1010 CONFIG_VIDEO_LOGO display Linux logo in
1012 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1013 linux_logo.h for logo.
1014 Requires CONFIG_VIDEO_LOGO
1015 CONFIG_CONSOLE_EXTRA_INFO
1016 additional board info beside
1019 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1020 a limited number of ANSI escape sequences (cursor control,
1021 erase functions and limited graphics rendition control).
1023 When CONFIG_CFB_CONSOLE is defined, video console is
1024 default i/o. Serial console can be forced with
1025 environment 'console=serial'.
1027 When CONFIG_SILENT_CONSOLE is defined, all console
1028 messages (by U-Boot and Linux!) can be silenced with
1029 the "silent" environment variable. See
1030 doc/README.silent for more information.
1032 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1034 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1038 CONFIG_BAUDRATE - in bps
1039 Select one of the baudrates listed in
1040 CONFIG_SYS_BAUDRATE_TABLE, see below.
1041 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1043 - Console Rx buffer length
1044 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1045 the maximum receive buffer length for the SMC.
1046 This option is actual only for 82xx and 8xx possible.
1047 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1048 must be defined, to setup the maximum idle timeout for
1051 - Pre-Console Buffer:
1052 Prior to the console being initialised (i.e. serial UART
1053 initialised etc) all console output is silently discarded.
1054 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1055 buffer any console messages prior to the console being
1056 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1057 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1058 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1059 bytes are output before the console is initialised, the
1060 earlier bytes are discarded.
1062 Note that when printing the buffer a copy is made on the
1063 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
1065 'Sane' compilers will generate smaller code if
1066 CONFIG_PRE_CON_BUF_SZ is a power of 2
1068 - Safe printf() functions
1069 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1070 the printf() functions. These are defined in
1071 include/vsprintf.h and include snprintf(), vsnprintf() and
1072 so on. Code size increase is approximately 300-500 bytes.
1073 If this option is not given then these functions will
1074 silently discard their buffer size argument - this means
1075 you are not getting any overflow checking in this case.
1077 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1078 Delay before automatically booting the default image;
1079 set to -1 to disable autoboot.
1080 set to -2 to autoboot with no delay and not check for abort
1081 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1083 See doc/README.autoboot for these options that
1084 work with CONFIG_BOOTDELAY. None are required.
1085 CONFIG_BOOT_RETRY_TIME
1086 CONFIG_BOOT_RETRY_MIN
1087 CONFIG_AUTOBOOT_KEYED
1088 CONFIG_AUTOBOOT_PROMPT
1089 CONFIG_AUTOBOOT_DELAY_STR
1090 CONFIG_AUTOBOOT_STOP_STR
1091 CONFIG_ZERO_BOOTDELAY_CHECK
1092 CONFIG_RESET_TO_RETRY
1096 Only needed when CONFIG_BOOTDELAY is enabled;
1097 define a command string that is automatically executed
1098 when no character is read on the console interface
1099 within "Boot Delay" after reset.
1102 This can be used to pass arguments to the bootm
1103 command. The value of CONFIG_BOOTARGS goes into the
1104 environment value "bootargs".
1106 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1107 The value of these goes into the environment as
1108 "ramboot" and "nfsboot" respectively, and can be used
1109 as a convenience, when switching between booting from
1113 CONFIG_BOOTCOUNT_LIMIT
1114 Implements a mechanism for detecting a repeating reboot
1116 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1118 CONFIG_BOOTCOUNT_ENV
1119 If no softreset save registers are found on the hardware
1120 "bootcount" is stored in the environment. To prevent a
1121 saveenv on all reboots, the environment variable
1122 "upgrade_available" is used. If "upgrade_available" is
1123 0, "bootcount" is always 0, if "upgrade_available" is
1124 1 "bootcount" is incremented in the environment.
1125 So the Userspace Applikation must set the "upgrade_available"
1126 and "bootcount" variable to 0, if a boot was successfully.
1128 - Pre-Boot Commands:
1131 When this option is #defined, the existence of the
1132 environment variable "preboot" will be checked
1133 immediately before starting the CONFIG_BOOTDELAY
1134 countdown and/or running the auto-boot command resp.
1135 entering interactive mode.
1137 This feature is especially useful when "preboot" is
1138 automatically generated or modified. For an example
1139 see the LWMON board specific code: here "preboot" is
1140 modified when the user holds down a certain
1141 combination of keys on the (special) keyboard when
1144 - Serial Download Echo Mode:
1146 If defined to 1, all characters received during a
1147 serial download (using the "loads" command) are
1148 echoed back. This might be needed by some terminal
1149 emulations (like "cu"), but may as well just take
1150 time on others. This setting #define's the initial
1151 value of the "loads_echo" environment variable.
1153 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1154 CONFIG_KGDB_BAUDRATE
1155 Select one of the baudrates listed in
1156 CONFIG_SYS_BAUDRATE_TABLE, see below.
1158 - Monitor Functions:
1159 Monitor commands can be included or excluded
1160 from the build by using the #include files
1161 <config_cmd_all.h> and #undef'ing unwanted
1162 commands, or adding #define's for wanted commands.
1164 The default command configuration includes all commands
1165 except those marked below with a "*".
1167 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1168 CONFIG_CMD_ASKENV * ask for env variable
1169 CONFIG_CMD_BDI bdinfo
1170 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1171 CONFIG_CMD_BMP * BMP support
1172 CONFIG_CMD_BSP * Board specific commands
1173 CONFIG_CMD_BOOTD bootd
1174 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1175 CONFIG_CMD_CACHE * icache, dcache
1176 CONFIG_CMD_CLK * clock command support
1177 CONFIG_CMD_CONSOLE coninfo
1178 CONFIG_CMD_CRC32 * crc32
1179 CONFIG_CMD_DATE * support for RTC, date/time...
1180 CONFIG_CMD_DHCP * DHCP support
1181 CONFIG_CMD_DIAG * Diagnostics
1182 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1183 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1184 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1185 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1186 CONFIG_CMD_DTT * Digital Therm and Thermostat
1187 CONFIG_CMD_ECHO echo arguments
1188 CONFIG_CMD_EDITENV edit env variable
1189 CONFIG_CMD_EEPROM * EEPROM read/write support
1190 CONFIG_CMD_ELF * bootelf, bootvx
1191 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1192 CONFIG_CMD_ENV_FLAGS * display details about env flags
1193 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1194 CONFIG_CMD_EXPORTENV * export the environment
1195 CONFIG_CMD_EXT2 * ext2 command support
1196 CONFIG_CMD_EXT4 * ext4 command support
1197 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1198 that work for multiple fs types
1199 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1200 CONFIG_CMD_SAVEENV saveenv
1201 CONFIG_CMD_FDC * Floppy Disk Support
1202 CONFIG_CMD_FAT * FAT command support
1203 CONFIG_CMD_FLASH flinfo, erase, protect
1204 CONFIG_CMD_FPGA FPGA device initialization support
1205 CONFIG_CMD_FUSE * Device fuse support
1206 CONFIG_CMD_GETTIME * Get time since boot
1207 CONFIG_CMD_GO * the 'go' command (exec code)
1208 CONFIG_CMD_GREPENV * search environment
1209 CONFIG_CMD_HASH * calculate hash / digest
1210 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1211 CONFIG_CMD_I2C * I2C serial bus support
1212 CONFIG_CMD_IDE * IDE harddisk support
1213 CONFIG_CMD_IMI iminfo
1214 CONFIG_CMD_IMLS List all images found in NOR flash
1215 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1216 CONFIG_CMD_IMMAP * IMMR dump support
1217 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1218 CONFIG_CMD_IMPORTENV * import an environment
1219 CONFIG_CMD_INI * import data from an ini file into the env
1220 CONFIG_CMD_IRQ * irqinfo
1221 CONFIG_CMD_ITEST Integer/string test of 2 values
1222 CONFIG_CMD_JFFS2 * JFFS2 Support
1223 CONFIG_CMD_KGDB * kgdb
1224 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1225 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1227 CONFIG_CMD_LOADB loadb
1228 CONFIG_CMD_LOADS loads
1229 CONFIG_CMD_MD5SUM * print md5 message digest
1230 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1231 CONFIG_CMD_MEMINFO * Display detailed memory information
1232 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1234 CONFIG_CMD_MEMTEST * mtest
1235 CONFIG_CMD_MISC Misc functions like sleep etc
1236 CONFIG_CMD_MMC * MMC memory mapped support
1237 CONFIG_CMD_MII * MII utility commands
1238 CONFIG_CMD_MTDPARTS * MTD partition support
1239 CONFIG_CMD_NAND * NAND support
1240 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1241 CONFIG_CMD_NFS NFS support
1242 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1243 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1244 CONFIG_CMD_PCI * pciinfo
1245 CONFIG_CMD_PCMCIA * PCMCIA support
1246 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1248 CONFIG_CMD_PORTIO * Port I/O
1249 CONFIG_CMD_READ * Read raw data from partition
1250 CONFIG_CMD_REGINFO * Register dump
1251 CONFIG_CMD_RUN run command in env variable
1252 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1253 CONFIG_CMD_SAVES * save S record dump
1254 CONFIG_CMD_SCSI * SCSI Support
1255 CONFIG_CMD_SDRAM * print SDRAM configuration information
1256 (requires CONFIG_CMD_I2C)
1257 CONFIG_CMD_SETGETDCR Support for DCR Register access
1259 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1260 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1261 (requires CONFIG_CMD_MEMORY)
1262 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1263 CONFIG_CMD_SOURCE "source" command Support
1264 CONFIG_CMD_SPI * SPI serial bus support
1265 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1266 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1267 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1268 CONFIG_CMD_TIMER * access to the system tick timer
1269 CONFIG_CMD_USB * USB support
1270 CONFIG_CMD_CDP * Cisco Discover Protocol support
1271 CONFIG_CMD_MFSL * Microblaze FSL support
1272 CONFIG_CMD_XIMG Load part of Multi Image
1273 CONFIG_CMD_UUID * Generate random UUID or GUID string
1275 EXAMPLE: If you want all functions except of network
1276 support you can write:
1278 #include "config_cmd_all.h"
1279 #undef CONFIG_CMD_NET
1282 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1284 Note: Don't enable the "icache" and "dcache" commands
1285 (configuration option CONFIG_CMD_CACHE) unless you know
1286 what you (and your U-Boot users) are doing. Data
1287 cache cannot be enabled on systems like the 8xx or
1288 8260 (where accesses to the IMMR region must be
1289 uncached), and it cannot be disabled on all other
1290 systems where we (mis-) use the data cache to hold an
1291 initial stack and some data.
1294 XXX - this list needs to get updated!
1296 - Regular expression support:
1298 If this variable is defined, U-Boot is linked against
1299 the SLRE (Super Light Regular Expression) library,
1300 which adds regex support to some commands, as for
1301 example "env grep" and "setexpr".
1305 If this variable is defined, U-Boot will use a device tree
1306 to configure its devices, instead of relying on statically
1307 compiled #defines in the board file. This option is
1308 experimental and only available on a few boards. The device
1309 tree is available in the global data as gd->fdt_blob.
1311 U-Boot needs to get its device tree from somewhere. This can
1312 be done using one of the two options below:
1315 If this variable is defined, U-Boot will embed a device tree
1316 binary in its image. This device tree file should be in the
1317 board directory and called <soc>-<board>.dts. The binary file
1318 is then picked up in board_init_f() and made available through
1319 the global data structure as gd->blob.
1322 If this variable is defined, U-Boot will build a device tree
1323 binary. It will be called u-boot.dtb. Architecture-specific
1324 code will locate it at run-time. Generally this works by:
1326 cat u-boot.bin u-boot.dtb >image.bin
1328 and in fact, U-Boot does this for you, creating a file called
1329 u-boot-dtb.bin which is useful in the common case. You can
1330 still use the individual files if you need something more
1335 If this variable is defined, it enables watchdog
1336 support for the SoC. There must be support in the SoC
1337 specific code for a watchdog. For the 8xx and 8260
1338 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1339 register. When supported for a specific SoC is
1340 available, then no further board specific code should
1341 be needed to use it.
1344 When using a watchdog circuitry external to the used
1345 SoC, then define this variable and provide board
1346 specific code for the "hw_watchdog_reset" function.
1348 CONFIG_AT91_HW_WDT_TIMEOUT
1349 specify the timeout in seconds. default 2 seconds.
1352 CONFIG_VERSION_VARIABLE
1353 If this variable is defined, an environment variable
1354 named "ver" is created by U-Boot showing the U-Boot
1355 version as printed by the "version" command.
1356 Any change to this variable will be reverted at the
1361 When CONFIG_CMD_DATE is selected, the type of the RTC
1362 has to be selected, too. Define exactly one of the
1365 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1366 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1367 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1368 CONFIG_RTC_MC146818 - use MC146818 RTC
1369 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1370 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1371 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1372 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1373 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1374 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1375 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1376 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1377 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1380 Note that if the RTC uses I2C, then the I2C interface
1381 must also be configured. See I2C Support, below.
1384 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1386 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1387 chip-ngpio pairs that tell the PCA953X driver the number of
1388 pins supported by a particular chip.
1390 Note that if the GPIO device uses I2C, then the I2C interface
1391 must also be configured. See I2C Support, below.
1394 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1395 accesses and can checksum them or write a list of them out
1396 to memory. See the 'iotrace' command for details. This is
1397 useful for testing device drivers since it can confirm that
1398 the driver behaves the same way before and after a code
1399 change. Currently this is supported on sandbox and arm. To
1400 add support for your architecture, add '#include <iotrace.h>'
1401 to the bottom of arch/<arch>/include/asm/io.h and test.
1403 Example output from the 'iotrace stats' command is below.
1404 Note that if the trace buffer is exhausted, the checksum will
1405 still continue to operate.
1408 Start: 10000000 (buffer start address)
1409 Size: 00010000 (buffer size)
1410 Offset: 00000120 (current buffer offset)
1411 Output: 10000120 (start + offset)
1412 Count: 00000018 (number of trace records)
1413 CRC32: 9526fb66 (CRC32 of all trace records)
1415 - Timestamp Support:
1417 When CONFIG_TIMESTAMP is selected, the timestamp
1418 (date and time) of an image is printed by image
1419 commands like bootm or iminfo. This option is
1420 automatically enabled when you select CONFIG_CMD_DATE .
1422 - Partition Labels (disklabels) Supported:
1423 Zero or more of the following:
1424 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1425 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1426 Intel architecture, USB sticks, etc.
1427 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1428 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1429 bootloader. Note 2TB partition limit; see
1431 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1433 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1434 CONFIG_CMD_SCSI) you must configure support for at
1435 least one non-MTD partition type as well.
1438 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1439 board configurations files but used nowhere!
1441 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1442 be performed by calling the function
1443 ide_set_reset(int reset)
1444 which has to be defined in a board specific file
1449 Set this to enable ATAPI support.
1454 Set this to enable support for disks larger than 137GB
1455 Also look at CONFIG_SYS_64BIT_LBA.
1456 Whithout these , LBA48 support uses 32bit variables and will 'only'
1457 support disks up to 2.1TB.
1459 CONFIG_SYS_64BIT_LBA:
1460 When enabled, makes the IDE subsystem use 64bit sector addresses.
1464 At the moment only there is only support for the
1465 SYM53C8XX SCSI controller; define
1466 CONFIG_SCSI_SYM53C8XX to enable it.
1468 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1469 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1470 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1471 maximum numbers of LUNs, SCSI ID's and target
1473 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1475 The environment variable 'scsidevs' is set to the number of
1476 SCSI devices found during the last scan.
1478 - NETWORK Support (PCI):
1480 Support for Intel 8254x/8257x gigabit chips.
1483 Utility code for direct access to the SPI bus on Intel 8257x.
1484 This does not do anything useful unless you set at least one
1485 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1487 CONFIG_E1000_SPI_GENERIC
1488 Allow generic access to the SPI bus on the Intel 8257x, for
1489 example with the "sspi" command.
1492 Management command for E1000 devices. When used on devices
1493 with SPI support you can reprogram the EEPROM from U-Boot.
1495 CONFIG_E1000_FALLBACK_MAC
1496 default MAC for empty EEPROM after production.
1499 Support for Intel 82557/82559/82559ER chips.
1500 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1501 write routine for first time initialisation.
1504 Support for Digital 2114x chips.
1505 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1506 modem chip initialisation (KS8761/QS6611).
1509 Support for National dp83815 chips.
1512 Support for National dp8382[01] gigabit chips.
1514 - NETWORK Support (other):
1516 CONFIG_DRIVER_AT91EMAC
1517 Support for AT91RM9200 EMAC.
1520 Define this to use reduced MII inteface
1522 CONFIG_DRIVER_AT91EMAC_QUIET
1523 If this defined, the driver is quiet.
1524 The driver doen't show link status messages.
1526 CONFIG_CALXEDA_XGMAC
1527 Support for the Calxeda XGMAC device
1530 Support for SMSC's LAN91C96 chips.
1532 CONFIG_LAN91C96_BASE
1533 Define this to hold the physical address
1534 of the LAN91C96's I/O space
1536 CONFIG_LAN91C96_USE_32_BIT
1537 Define this to enable 32 bit addressing
1540 Support for SMSC's LAN91C111 chip
1542 CONFIG_SMC91111_BASE
1543 Define this to hold the physical address
1544 of the device (I/O space)
1546 CONFIG_SMC_USE_32_BIT
1547 Define this if data bus is 32 bits
1549 CONFIG_SMC_USE_IOFUNCS
1550 Define this to use i/o functions instead of macros
1551 (some hardware wont work with macros)
1553 CONFIG_DRIVER_TI_EMAC
1554 Support for davinci emac
1556 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1557 Define this if you have more then 3 PHYs.
1560 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1562 CONFIG_FTGMAC100_EGIGA
1563 Define this to use GE link update with gigabit PHY.
1564 Define this if FTGMAC100 is connected to gigabit PHY.
1565 If your system has 10/100 PHY only, it might not occur
1566 wrong behavior. Because PHY usually return timeout or
1567 useless data when polling gigabit status and gigabit
1568 control registers. This behavior won't affect the
1569 correctnessof 10/100 link speed update.
1572 Support for SMSC's LAN911x and LAN921x chips
1575 Define this to hold the physical address
1576 of the device (I/O space)
1578 CONFIG_SMC911X_32_BIT
1579 Define this if data bus is 32 bits
1581 CONFIG_SMC911X_16_BIT
1582 Define this if data bus is 16 bits. If your processor
1583 automatically converts one 32 bit word to two 16 bit
1584 words you may also try CONFIG_SMC911X_32_BIT.
1587 Support for Renesas on-chip Ethernet controller
1589 CONFIG_SH_ETHER_USE_PORT
1590 Define the number of ports to be used
1592 CONFIG_SH_ETHER_PHY_ADDR
1593 Define the ETH PHY's address
1595 CONFIG_SH_ETHER_CACHE_WRITEBACK
1596 If this option is set, the driver enables cache flush.
1600 Support for PWM modul on the imx6.
1604 Support TPM devices.
1607 Support for i2c bus TPM devices. Only one device
1608 per system is supported at this time.
1610 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1611 Define the the i2c bus number for the TPM device
1613 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1614 Define the TPM's address on the i2c bus
1616 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1617 Define the burst count bytes upper limit
1619 CONFIG_TPM_ATMEL_TWI
1620 Support for Atmel TWI TPM device. Requires I2C support.
1623 Support for generic parallel port TPM devices. Only one device
1624 per system is supported at this time.
1626 CONFIG_TPM_TIS_BASE_ADDRESS
1627 Base address where the generic TPM device is mapped
1628 to. Contemporary x86 systems usually map it at
1632 Add tpm monitor functions.
1633 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1634 provides monitor access to authorized functions.
1637 Define this to enable the TPM support library which provides
1638 functional interfaces to some TPM commands.
1639 Requires support for a TPM device.
1641 CONFIG_TPM_AUTH_SESSIONS
1642 Define this to enable authorized functions in the TPM library.
1643 Requires CONFIG_TPM and CONFIG_SHA1.
1646 At the moment only the UHCI host controller is
1647 supported (PIP405, MIP405, MPC5200); define
1648 CONFIG_USB_UHCI to enable it.
1649 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1650 and define CONFIG_USB_STORAGE to enable the USB
1653 Supported are USB Keyboards and USB Floppy drives
1655 MPC5200 USB requires additional defines:
1657 for 528 MHz Clock: 0x0001bbbb
1661 for differential drivers: 0x00001000
1662 for single ended drivers: 0x00005000
1663 for differential drivers on PSC3: 0x00000100
1664 for single ended drivers on PSC3: 0x00004100
1665 CONFIG_SYS_USB_EVENT_POLL
1666 May be defined to allow interrupt polling
1667 instead of using asynchronous interrupts
1669 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1670 txfilltuning field in the EHCI controller on reset.
1672 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1673 HW module registers.
1676 Define the below if you wish to use the USB console.
1677 Once firmware is rebuilt from a serial console issue the
1678 command "setenv stdin usbtty; setenv stdout usbtty" and
1679 attach your USB cable. The Unix command "dmesg" should print
1680 it has found a new device. The environment variable usbtty
1681 can be set to gserial or cdc_acm to enable your device to
1682 appear to a USB host as a Linux gserial device or a
1683 Common Device Class Abstract Control Model serial device.
1684 If you select usbtty = gserial you should be able to enumerate
1686 # modprobe usbserial vendor=0xVendorID product=0xProductID
1687 else if using cdc_acm, simply setting the environment
1688 variable usbtty to be cdc_acm should suffice. The following
1689 might be defined in YourBoardName.h
1692 Define this to build a UDC device
1695 Define this to have a tty type of device available to
1696 talk to the UDC device
1699 Define this to enable the high speed support for usb
1700 device and usbtty. If this feature is enabled, a routine
1701 int is_usbd_high_speed(void)
1702 also needs to be defined by the driver to dynamically poll
1703 whether the enumeration has succeded at high speed or full
1706 CONFIG_SYS_CONSOLE_IS_IN_ENV
1707 Define this if you want stdin, stdout &/or stderr to
1711 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1712 Derive USB clock from external clock "blah"
1713 - CONFIG_SYS_USB_EXTC_CLK 0x02
1715 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1716 Derive USB clock from brgclk
1717 - CONFIG_SYS_USB_BRG_CLK 0x04
1719 If you have a USB-IF assigned VendorID then you may wish to
1720 define your own vendor specific values either in BoardName.h
1721 or directly in usbd_vendor_info.h. If you don't define
1722 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1723 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1724 should pretend to be a Linux device to it's target host.
1726 CONFIG_USBD_MANUFACTURER
1727 Define this string as the name of your company for
1728 - CONFIG_USBD_MANUFACTURER "my company"
1730 CONFIG_USBD_PRODUCT_NAME
1731 Define this string as the name of your product
1732 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1734 CONFIG_USBD_VENDORID
1735 Define this as your assigned Vendor ID from the USB
1736 Implementors Forum. This *must* be a genuine Vendor ID
1737 to avoid polluting the USB namespace.
1738 - CONFIG_USBD_VENDORID 0xFFFF
1740 CONFIG_USBD_PRODUCTID
1741 Define this as the unique Product ID
1743 - CONFIG_USBD_PRODUCTID 0xFFFF
1745 - ULPI Layer Support:
1746 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1747 the generic ULPI layer. The generic layer accesses the ULPI PHY
1748 via the platform viewport, so you need both the genric layer and
1749 the viewport enabled. Currently only Chipidea/ARC based
1750 viewport is supported.
1751 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1752 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1753 If your ULPI phy needs a different reference clock than the
1754 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1755 the appropriate value in Hz.
1758 The MMC controller on the Intel PXA is supported. To
1759 enable this define CONFIG_MMC. The MMC can be
1760 accessed from the boot prompt by mapping the device
1761 to physical memory similar to flash. Command line is
1762 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1763 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1766 Support for Renesas on-chip MMCIF controller
1768 CONFIG_SH_MMCIF_ADDR
1769 Define the base address of MMCIF registers
1772 Define the clock frequency for MMCIF
1775 Enable the generic MMC driver
1777 CONFIG_SUPPORT_EMMC_BOOT
1778 Enable some additional features of the eMMC boot partitions.
1780 CONFIG_SUPPORT_EMMC_RPMB
1781 Enable the commands for reading, writing and programming the
1782 key for the Replay Protection Memory Block partition in eMMC.
1784 - USB Device Firmware Update (DFU) class support:
1785 CONFIG_USB_FUNCTION_DFU
1786 This enables the USB portion of the DFU USB class
1789 This enables the command "dfu" which is used to have
1790 U-Boot create a DFU class device via USB. This command
1791 requires that the "dfu_alt_info" environment variable be
1792 set and define the alt settings to expose to the host.
1795 This enables support for exposing (e)MMC devices via DFU.
1798 This enables support for exposing NAND devices via DFU.
1801 This enables support for exposing RAM via DFU.
1802 Note: DFU spec refer to non-volatile memory usage, but
1803 allow usages beyond the scope of spec - here RAM usage,
1804 one that would help mostly the developer.
1806 CONFIG_SYS_DFU_DATA_BUF_SIZE
1807 Dfu transfer uses a buffer before writing data to the
1808 raw storage device. Make the size (in bytes) of this buffer
1809 configurable. The size of this buffer is also configurable
1810 through the "dfu_bufsiz" environment variable.
1812 CONFIG_SYS_DFU_MAX_FILE_SIZE
1813 When updating files rather than the raw storage device,
1814 we use a static buffer to copy the file into and then write
1815 the buffer once we've been given the whole file. Define
1816 this to the maximum filesize (in bytes) for the buffer.
1817 Default is 4 MiB if undefined.
1819 DFU_DEFAULT_POLL_TIMEOUT
1820 Poll timeout [ms], is the timeout a device can send to the
1821 host. The host must wait for this timeout before sending
1822 a subsequent DFU_GET_STATUS request to the device.
1824 DFU_MANIFEST_POLL_TIMEOUT
1825 Poll timeout [ms], which the device sends to the host when
1826 entering dfuMANIFEST state. Host waits this timeout, before
1827 sending again an USB request to the device.
1829 - USB Device Android Fastboot support:
1830 CONFIG_USB_FUNCTION_FASTBOOT
1831 This enables the USB part of the fastboot gadget
1834 This enables the command "fastboot" which enables the Android
1835 fastboot mode for the platform's USB device. Fastboot is a USB
1836 protocol for downloading images, flashing and device control
1837 used on Android devices.
1838 See doc/README.android-fastboot for more information.
1840 CONFIG_ANDROID_BOOT_IMAGE
1841 This enables support for booting images which use the Android
1842 image format header.
1844 CONFIG_FASTBOOT_BUF_ADDR
1845 The fastboot protocol requires a large memory buffer for
1846 downloads. Define this to the starting RAM address to use for
1849 CONFIG_FASTBOOT_BUF_SIZE
1850 The fastboot protocol requires a large memory buffer for
1851 downloads. This buffer should be as large as possible for a
1852 platform. Define this to the size available RAM for fastboot.
1854 CONFIG_FASTBOOT_FLASH
1855 The fastboot protocol includes a "flash" command for writing
1856 the downloaded image to a non-volatile storage device. Define
1857 this to enable the "fastboot flash" command.
1859 CONFIG_FASTBOOT_FLASH_MMC_DEV
1860 The fastboot "flash" command requires additional information
1861 regarding the non-volatile storage device. Define this to
1862 the eMMC device that fastboot should use to store the image.
1864 CONFIG_FASTBOOT_GPT_NAME
1865 The fastboot "flash" command supports writing the downloaded
1866 image to the Protective MBR and the Primary GUID Partition
1867 Table. (Additionally, this downloaded image is post-processed
1868 to generate and write the Backup GUID Partition Table.)
1869 This occurs when the specified "partition name" on the
1870 "fastboot flash" command line matches this value.
1871 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1873 - Journaling Flash filesystem support:
1874 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1875 CONFIG_JFFS2_NAND_DEV
1876 Define these for a default partition on a NAND device
1878 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1879 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1880 Define these for a default partition on a NOR device
1882 CONFIG_SYS_JFFS_CUSTOM_PART
1883 Define this to create an own partition. You have to provide a
1884 function struct part_info* jffs2_part_info(int part_num)
1886 If you define only one JFFS2 partition you may also want to
1887 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1888 to disable the command chpart. This is the default when you
1889 have not defined a custom partition
1891 - FAT(File Allocation Table) filesystem write function support:
1894 Define this to enable support for saving memory data as a
1895 file in FAT formatted partition.
1897 This will also enable the command "fatwrite" enabling the
1898 user to write files to FAT.
1900 CBFS (Coreboot Filesystem) support
1903 Define this to enable support for reading from a Coreboot
1904 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1907 - FAT(File Allocation Table) filesystem cluster size:
1908 CONFIG_FS_FAT_MAX_CLUSTSIZE
1910 Define the max cluster size for fat operations else
1911 a default value of 65536 will be defined.
1916 Define this to enable standard (PC-Style) keyboard
1920 Standard PC keyboard driver with US (is default) and
1921 GERMAN key layout (switch via environment 'keymap=de') support.
1922 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1923 for cfb_console. Supports cursor blinking.
1926 Enables a Chrome OS keyboard using the CROS_EC interface.
1927 This uses CROS_EC to communicate with a second microcontroller
1928 which provides key scans on request.
1933 Define this to enable video support (for output to
1936 CONFIG_VIDEO_CT69000
1938 Enable Chips & Technologies 69000 Video chip
1940 CONFIG_VIDEO_SMI_LYNXEM
1941 Enable Silicon Motion SMI 712/710/810 Video chip. The
1942 video output is selected via environment 'videoout'
1943 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1946 For the CT69000 and SMI_LYNXEM drivers, videomode is
1947 selected via environment 'videomode'. Two different ways
1949 - "videomode=num" 'num' is a standard LiLo mode numbers.
1950 Following standard modes are supported (* is default):
1952 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1953 -------------+---------------------------------------------
1954 8 bits | 0x301* 0x303 0x305 0x161 0x307
1955 15 bits | 0x310 0x313 0x316 0x162 0x319
1956 16 bits | 0x311 0x314 0x317 0x163 0x31A
1957 24 bits | 0x312 0x315 0x318 ? 0x31B
1958 -------------+---------------------------------------------
1959 (i.e. setenv videomode 317; saveenv; reset;)
1961 - "videomode=bootargs" all the video parameters are parsed
1962 from the bootargs. (See drivers/video/videomodes.c)
1965 CONFIG_VIDEO_SED13806
1966 Enable Epson SED13806 driver. This driver supports 8bpp
1967 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1968 or CONFIG_VIDEO_SED13806_16BPP
1971 Enable the Freescale DIU video driver. Reference boards for
1972 SOCs that have a DIU should define this macro to enable DIU
1973 support, and should also define these other macros:
1979 CONFIG_VIDEO_SW_CURSOR
1980 CONFIG_VGA_AS_SINGLE_DEVICE
1982 CONFIG_VIDEO_BMP_LOGO
1984 The DIU driver will look for the 'video-mode' environment
1985 variable, and if defined, enable the DIU as a console during
1986 boot. See the documentation file README.video for a
1987 description of this variable.
1993 Define this to enable a custom keyboard support.
1994 This simply calls drv_keyboard_init() which must be
1995 defined in your board-specific files.
1996 The only board using this so far is RBC823.
1998 - LCD Support: CONFIG_LCD
2000 Define this to enable LCD support (for output to LCD
2001 display); also select one of the supported displays
2002 by defining one of these:
2006 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2008 CONFIG_NEC_NL6448AC33:
2010 NEC NL6448AC33-18. Active, color, single scan.
2012 CONFIG_NEC_NL6448BC20
2014 NEC NL6448BC20-08. 6.5", 640x480.
2015 Active, color, single scan.
2017 CONFIG_NEC_NL6448BC33_54
2019 NEC NL6448BC33-54. 10.4", 640x480.
2020 Active, color, single scan.
2024 Sharp 320x240. Active, color, single scan.
2025 It isn't 16x9, and I am not sure what it is.
2027 CONFIG_SHARP_LQ64D341
2029 Sharp LQ64D341 display, 640x480.
2030 Active, color, single scan.
2034 HLD1045 display, 640x480.
2035 Active, color, single scan.
2039 Optrex CBL50840-2 NF-FW 99 22 M5
2041 Hitachi LMG6912RPFC-00T
2045 320x240. Black & white.
2047 Normally display is black on white background; define
2048 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2050 CONFIG_LCD_ALIGNMENT
2052 Normally the LCD is page-aligned (typically 4KB). If this is
2053 defined then the LCD will be aligned to this value instead.
2054 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2055 here, since it is cheaper to change data cache settings on
2056 a per-section basis.
2058 CONFIG_CONSOLE_SCROLL_LINES
2060 When the console need to be scrolled, this is the number of
2061 lines to scroll by. It defaults to 1. Increasing this makes
2062 the console jump but can help speed up operation when scrolling
2067 Sometimes, for example if the display is mounted in portrait
2068 mode or even if it's mounted landscape but rotated by 180degree,
2069 we need to rotate our content of the display relative to the
2070 framebuffer, so that user can read the messages which are
2072 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2073 initialized with a given rotation from "vl_rot" out of
2074 "vidinfo_t" which is provided by the board specific code.
2075 The value for vl_rot is coded as following (matching to
2076 fbcon=rotate:<n> linux-kernel commandline):
2077 0 = no rotation respectively 0 degree
2078 1 = 90 degree rotation
2079 2 = 180 degree rotation
2080 3 = 270 degree rotation
2082 If CONFIG_LCD_ROTATION is not defined, the console will be
2083 initialized with 0degree rotation.
2087 Support drawing of RLE8-compressed bitmaps on the LCD.
2091 Enables an 'i2c edid' command which can read EDID
2092 information over I2C from an attached LCD display.
2094 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2096 If this option is set, the environment is checked for
2097 a variable "splashimage". If found, the usual display
2098 of logo, copyright and system information on the LCD
2099 is suppressed and the BMP image at the address
2100 specified in "splashimage" is loaded instead. The
2101 console is redirected to the "nulldev", too. This
2102 allows for a "silent" boot where a splash screen is
2103 loaded very quickly after power-on.
2105 CONFIG_SPLASHIMAGE_GUARD
2107 If this option is set, then U-Boot will prevent the environment
2108 variable "splashimage" from being set to a problematic address
2109 (see README.displaying-bmps).
2110 This option is useful for targets where, due to alignment
2111 restrictions, an improperly aligned BMP image will cause a data
2112 abort. If you think you will not have problems with unaligned
2113 accesses (for example because your toolchain prevents them)
2114 there is no need to set this option.
2116 CONFIG_SPLASH_SCREEN_ALIGN
2118 If this option is set the splash image can be freely positioned
2119 on the screen. Environment variable "splashpos" specifies the
2120 position as "x,y". If a positive number is given it is used as
2121 number of pixel from left/top. If a negative number is given it
2122 is used as number of pixel from right/bottom. You can also
2123 specify 'm' for centering the image.
2126 setenv splashpos m,m
2127 => image at center of screen
2129 setenv splashpos 30,20
2130 => image at x = 30 and y = 20
2132 setenv splashpos -10,m
2133 => vertically centered image
2134 at x = dspWidth - bmpWidth - 9
2136 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2138 If this option is set, additionally to standard BMP
2139 images, gzipped BMP images can be displayed via the
2140 splashscreen support or the bmp command.
2142 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2144 If this option is set, 8-bit RLE compressed BMP images
2145 can be displayed via the splashscreen support or the
2148 - Do compressing for memory range:
2151 If this option is set, it would use zlib deflate method
2152 to compress the specified memory at its best effort.
2154 - Compression support:
2157 Enabled by default to support gzip compressed images.
2161 If this option is set, support for bzip2 compressed
2162 images is included. If not, only uncompressed and gzip
2163 compressed images are supported.
2165 NOTE: the bzip2 algorithm requires a lot of RAM, so
2166 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2171 If this option is set, support for lzma compressed
2174 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2175 requires an amount of dynamic memory that is given by the
2178 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2180 Where lc and lp stand for, respectively, Literal context bits
2181 and Literal pos bits.
2183 This value is upper-bounded by 14MB in the worst case. Anyway,
2184 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2185 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2186 a very small buffer.
2188 Use the lzmainfo tool to determinate the lc and lp values and
2189 then calculate the amount of needed dynamic memory (ensuring
2190 the appropriate CONFIG_SYS_MALLOC_LEN value).
2194 If this option is set, support for LZO compressed images
2200 The address of PHY on MII bus.
2202 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2204 The clock frequency of the MII bus
2208 If this option is set, support for speed/duplex
2209 detection of gigabit PHY is included.
2211 CONFIG_PHY_RESET_DELAY
2213 Some PHY like Intel LXT971A need extra delay after
2214 reset before any MII register access is possible.
2215 For such PHY, set this option to the usec delay
2216 required. (minimum 300usec for LXT971A)
2218 CONFIG_PHY_CMD_DELAY (ppc4xx)
2220 Some PHY like Intel LXT971A need extra delay after
2221 command issued before MII status register can be read
2226 Define a default value for the IP address to use for
2227 the default Ethernet interface, in case this is not
2228 determined through e.g. bootp.
2229 (Environment variable "ipaddr")
2231 - Server IP address:
2234 Defines a default value for the IP address of a TFTP
2235 server to contact when using the "tftboot" command.
2236 (Environment variable "serverip")
2238 CONFIG_KEEP_SERVERADDR
2240 Keeps the server's MAC address, in the env 'serveraddr'
2241 for passing to bootargs (like Linux's netconsole option)
2243 - Gateway IP address:
2246 Defines a default value for the IP address of the
2247 default router where packets to other networks are
2249 (Environment variable "gatewayip")
2254 Defines a default value for the subnet mask (or
2255 routing prefix) which is used to determine if an IP
2256 address belongs to the local subnet or needs to be
2257 forwarded through a router.
2258 (Environment variable "netmask")
2260 - Multicast TFTP Mode:
2263 Defines whether you want to support multicast TFTP as per
2264 rfc-2090; for example to work with atftp. Lets lots of targets
2265 tftp down the same boot image concurrently. Note: the Ethernet
2266 driver in use must provide a function: mcast() to join/leave a
2269 - BOOTP Recovery Mode:
2270 CONFIG_BOOTP_RANDOM_DELAY
2272 If you have many targets in a network that try to
2273 boot using BOOTP, you may want to avoid that all
2274 systems send out BOOTP requests at precisely the same
2275 moment (which would happen for instance at recovery
2276 from a power failure, when all systems will try to
2277 boot, thus flooding the BOOTP server. Defining
2278 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2279 inserted before sending out BOOTP requests. The
2280 following delays are inserted then:
2282 1st BOOTP request: delay 0 ... 1 sec
2283 2nd BOOTP request: delay 0 ... 2 sec
2284 3rd BOOTP request: delay 0 ... 4 sec
2286 BOOTP requests: delay 0 ... 8 sec
2288 CONFIG_BOOTP_ID_CACHE_SIZE
2290 BOOTP packets are uniquely identified using a 32-bit ID. The
2291 server will copy the ID from client requests to responses and
2292 U-Boot will use this to determine if it is the destination of
2293 an incoming response. Some servers will check that addresses
2294 aren't in use before handing them out (usually using an ARP
2295 ping) and therefore take up to a few hundred milliseconds to
2296 respond. Network congestion may also influence the time it
2297 takes for a response to make it back to the client. If that
2298 time is too long, U-Boot will retransmit requests. In order
2299 to allow earlier responses to still be accepted after these
2300 retransmissions, U-Boot's BOOTP client keeps a small cache of
2301 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2302 cache. The default is to keep IDs for up to four outstanding
2303 requests. Increasing this will allow U-Boot to accept offers
2304 from a BOOTP client in networks with unusually high latency.
2306 - BOOTP Random transaction ID:
2307 CONFIG_BOOTP_RANDOM_ID
2309 The standard algorithm to generate a DHCP/BOOTP transaction ID
2310 by using the MAC address and the current time stamp may not
2311 quite unlikely produce duplicate transaction IDs from different
2312 clients in the same network. This option creates a transaction
2313 ID using the rand() function. Provided that the RNG has been
2314 seeded well, this should guarantee unique transaction IDs
2317 - DHCP Advanced Options:
2318 You can fine tune the DHCP functionality by defining
2319 CONFIG_BOOTP_* symbols:
2321 CONFIG_BOOTP_SUBNETMASK
2322 CONFIG_BOOTP_GATEWAY
2323 CONFIG_BOOTP_HOSTNAME
2324 CONFIG_BOOTP_NISDOMAIN
2325 CONFIG_BOOTP_BOOTPATH
2326 CONFIG_BOOTP_BOOTFILESIZE
2329 CONFIG_BOOTP_SEND_HOSTNAME
2330 CONFIG_BOOTP_NTPSERVER
2331 CONFIG_BOOTP_TIMEOFFSET
2332 CONFIG_BOOTP_VENDOREX
2333 CONFIG_BOOTP_MAY_FAIL
2335 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2336 environment variable, not the BOOTP server.
2338 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2339 after the configured retry count, the call will fail
2340 instead of starting over. This can be used to fail over
2341 to Link-local IP address configuration if the DHCP server
2344 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2345 serverip from a DHCP server, it is possible that more
2346 than one DNS serverip is offered to the client.
2347 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2348 serverip will be stored in the additional environment
2349 variable "dnsip2". The first DNS serverip is always
2350 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2353 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2354 to do a dynamic update of a DNS server. To do this, they
2355 need the hostname of the DHCP requester.
2356 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2357 of the "hostname" environment variable is passed as
2358 option 12 to the DHCP server.
2360 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2362 A 32bit value in microseconds for a delay between
2363 receiving a "DHCP Offer" and sending the "DHCP Request".
2364 This fixes a problem with certain DHCP servers that don't
2365 respond 100% of the time to a "DHCP request". E.g. On an
2366 AT91RM9200 processor running at 180MHz, this delay needed
2367 to be *at least* 15,000 usec before a Windows Server 2003
2368 DHCP server would reply 100% of the time. I recommend at
2369 least 50,000 usec to be safe. The alternative is to hope
2370 that one of the retries will be successful but note that
2371 the DHCP timeout and retry process takes a longer than
2374 - Link-local IP address negotiation:
2375 Negotiate with other link-local clients on the local network
2376 for an address that doesn't require explicit configuration.
2377 This is especially useful if a DHCP server cannot be guaranteed
2378 to exist in all environments that the device must operate.
2380 See doc/README.link-local for more information.
2383 CONFIG_CDP_DEVICE_ID
2385 The device id used in CDP trigger frames.
2387 CONFIG_CDP_DEVICE_ID_PREFIX
2389 A two character string which is prefixed to the MAC address
2394 A printf format string which contains the ascii name of
2395 the port. Normally is set to "eth%d" which sets
2396 eth0 for the first Ethernet, eth1 for the second etc.
2398 CONFIG_CDP_CAPABILITIES
2400 A 32bit integer which indicates the device capabilities;
2401 0x00000010 for a normal host which does not forwards.
2405 An ascii string containing the version of the software.
2409 An ascii string containing the name of the platform.
2413 A 32bit integer sent on the trigger.
2415 CONFIG_CDP_POWER_CONSUMPTION
2417 A 16bit integer containing the power consumption of the
2418 device in .1 of milliwatts.
2420 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2422 A byte containing the id of the VLAN.
2424 - Status LED: CONFIG_STATUS_LED
2426 Several configurations allow to display the current
2427 status using a LED. For instance, the LED will blink
2428 fast while running U-Boot code, stop blinking as
2429 soon as a reply to a BOOTP request was received, and
2430 start blinking slow once the Linux kernel is running
2431 (supported by a status LED driver in the Linux
2432 kernel). Defining CONFIG_STATUS_LED enables this
2438 The status LED can be connected to a GPIO pin.
2439 In such cases, the gpio_led driver can be used as a
2440 status LED backend implementation. Define CONFIG_GPIO_LED
2441 to include the gpio_led driver in the U-Boot binary.
2443 CONFIG_GPIO_LED_INVERTED_TABLE
2444 Some GPIO connected LEDs may have inverted polarity in which
2445 case the GPIO high value corresponds to LED off state and
2446 GPIO low value corresponds to LED on state.
2447 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2448 with a list of GPIO LEDs that have inverted polarity.
2450 - CAN Support: CONFIG_CAN_DRIVER
2452 Defining CONFIG_CAN_DRIVER enables CAN driver support
2453 on those systems that support this (optional)
2454 feature, like the TQM8xxL modules.
2456 - I2C Support: CONFIG_SYS_I2C
2458 This enable the NEW i2c subsystem, and will allow you to use
2459 i2c commands at the u-boot command line (as long as you set
2460 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2461 based realtime clock chips or other i2c devices. See
2462 common/cmd_i2c.c for a description of the command line
2465 ported i2c driver to the new framework:
2466 - drivers/i2c/soft_i2c.c:
2467 - activate first bus with CONFIG_SYS_I2C_SOFT define
2468 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2469 for defining speed and slave address
2470 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2471 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2472 for defining speed and slave address
2473 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2474 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2475 for defining speed and slave address
2476 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2477 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2478 for defining speed and slave address
2480 - drivers/i2c/fsl_i2c.c:
2481 - activate i2c driver with CONFIG_SYS_I2C_FSL
2482 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2483 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2484 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2486 - If your board supports a second fsl i2c bus, define
2487 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2488 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2489 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2492 - drivers/i2c/tegra_i2c.c:
2493 - activate this driver with CONFIG_SYS_I2C_TEGRA
2494 - This driver adds 4 i2c buses with a fix speed from
2495 100000 and the slave addr 0!
2497 - drivers/i2c/ppc4xx_i2c.c
2498 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2499 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2500 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2502 - drivers/i2c/i2c_mxc.c
2503 - activate this driver with CONFIG_SYS_I2C_MXC
2504 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2505 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2506 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2507 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2508 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2509 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2510 If those defines are not set, default value is 100000
2511 for speed, and 0 for slave.
2512 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2513 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2515 - drivers/i2c/rcar_i2c.c:
2516 - activate this driver with CONFIG_SYS_I2C_RCAR
2517 - This driver adds 4 i2c buses
2519 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2520 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2521 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2522 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2523 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2524 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2525 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2526 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2527 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2529 - drivers/i2c/sh_i2c.c:
2530 - activate this driver with CONFIG_SYS_I2C_SH
2531 - This driver adds from 2 to 5 i2c buses
2533 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2534 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2535 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2536 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2537 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2538 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2539 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2540 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2541 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2542 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2543 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2544 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2545 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2547 - drivers/i2c/omap24xx_i2c.c
2548 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2549 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2550 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2551 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2552 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2553 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2554 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2555 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2556 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2557 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2558 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2560 - drivers/i2c/zynq_i2c.c
2561 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2562 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2563 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2565 - drivers/i2c/s3c24x0_i2c.c:
2566 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2567 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2568 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2569 with a fix speed from 100000 and the slave addr 0!
2571 - drivers/i2c/ihs_i2c.c
2572 - activate this driver with CONFIG_SYS_I2C_IHS
2573 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2574 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2575 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2576 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2577 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2578 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2579 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2580 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2581 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2582 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2583 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2584 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2588 CONFIG_SYS_NUM_I2C_BUSES
2589 Hold the number of i2c buses you want to use. If you
2590 don't use/have i2c muxes on your i2c bus, this
2591 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2594 CONFIG_SYS_I2C_DIRECT_BUS
2595 define this, if you don't use i2c muxes on your hardware.
2596 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2599 CONFIG_SYS_I2C_MAX_HOPS
2600 define how many muxes are maximal consecutively connected
2601 on one i2c bus. If you not use i2c muxes, omit this
2604 CONFIG_SYS_I2C_BUSES
2605 hold a list of buses you want to use, only used if
2606 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2607 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2608 CONFIG_SYS_NUM_I2C_BUSES = 9:
2610 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2612 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2613 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2614 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2615 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2616 {1, {I2C_NULL_HOP}}, \
2617 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2618 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2622 bus 0 on adapter 0 without a mux
2623 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2624 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2625 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2626 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2627 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2628 bus 6 on adapter 1 without a mux
2629 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2630 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2632 If you do not have i2c muxes on your board, omit this define.
2634 - Legacy I2C Support: CONFIG_HARD_I2C
2636 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2637 provides the following compelling advantages:
2639 - more than one i2c adapter is usable
2640 - approved multibus support
2641 - better i2c mux support
2643 ** Please consider updating your I2C driver now. **
2645 These enable legacy I2C serial bus commands. Defining
2646 CONFIG_HARD_I2C will include the appropriate I2C driver
2647 for the selected CPU.
2649 This will allow you to use i2c commands at the u-boot
2650 command line (as long as you set CONFIG_CMD_I2C in
2651 CONFIG_COMMANDS) and communicate with i2c based realtime
2652 clock chips. See common/cmd_i2c.c for a description of the
2653 command line interface.
2655 CONFIG_HARD_I2C selects a hardware I2C controller.
2657 There are several other quantities that must also be
2658 defined when you define CONFIG_HARD_I2C.
2660 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2661 to be the frequency (in Hz) at which you wish your i2c bus
2662 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2663 the CPU's i2c node address).
2665 Now, the u-boot i2c code for the mpc8xx
2666 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2667 and so its address should therefore be cleared to 0 (See,
2668 eg, MPC823e User's Manual p.16-473). So, set
2669 CONFIG_SYS_I2C_SLAVE to 0.
2671 CONFIG_SYS_I2C_INIT_MPC5XXX
2673 When a board is reset during an i2c bus transfer
2674 chips might think that the current transfer is still
2675 in progress. Reset the slave devices by sending start
2676 commands until the slave device responds.
2678 That's all that's required for CONFIG_HARD_I2C.
2680 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2681 then the following macros need to be defined (examples are
2682 from include/configs/lwmon.h):
2686 (Optional). Any commands necessary to enable the I2C
2687 controller or configure ports.
2689 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2693 (Only for MPC8260 CPU). The I/O port to use (the code
2694 assumes both bits are on the same port). Valid values
2695 are 0..3 for ports A..D.
2699 The code necessary to make the I2C data line active
2700 (driven). If the data line is open collector, this
2703 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2707 The code necessary to make the I2C data line tri-stated
2708 (inactive). If the data line is open collector, this
2711 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2715 Code that returns true if the I2C data line is high,
2718 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2722 If <bit> is true, sets the I2C data line high. If it
2723 is false, it clears it (low).
2725 eg: #define I2C_SDA(bit) \
2726 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2727 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2731 If <bit> is true, sets the I2C clock line high. If it
2732 is false, it clears it (low).
2734 eg: #define I2C_SCL(bit) \
2735 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2736 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2740 This delay is invoked four times per clock cycle so this
2741 controls the rate of data transfer. The data rate thus
2742 is 1 / (I2C_DELAY * 4). Often defined to be something
2745 #define I2C_DELAY udelay(2)
2747 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2749 If your arch supports the generic GPIO framework (asm/gpio.h),
2750 then you may alternatively define the two GPIOs that are to be
2751 used as SCL / SDA. Any of the previous I2C_xxx macros will
2752 have GPIO-based defaults assigned to them as appropriate.
2754 You should define these to the GPIO value as given directly to
2755 the generic GPIO functions.
2757 CONFIG_SYS_I2C_INIT_BOARD
2759 When a board is reset during an i2c bus transfer
2760 chips might think that the current transfer is still
2761 in progress. On some boards it is possible to access
2762 the i2c SCLK line directly, either by using the
2763 processor pin as a GPIO or by having a second pin
2764 connected to the bus. If this option is defined a
2765 custom i2c_init_board() routine in boards/xxx/board.c
2766 is run early in the boot sequence.
2768 CONFIG_SYS_I2C_BOARD_LATE_INIT
2770 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2771 defined a custom i2c_board_late_init() routine in
2772 boards/xxx/board.c is run AFTER the operations in i2c_init()
2773 is completed. This callpoint can be used to unreset i2c bus
2774 using CPU i2c controller register accesses for CPUs whose i2c
2775 controller provide such a method. It is called at the end of
2776 i2c_init() to allow i2c_init operations to setup the i2c bus
2777 controller on the CPU (e.g. setting bus speed & slave address).
2779 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2781 This option enables configuration of bi_iic_fast[] flags
2782 in u-boot bd_info structure based on u-boot environment
2783 variable "i2cfast". (see also i2cfast)
2785 CONFIG_I2C_MULTI_BUS
2787 This option allows the use of multiple I2C buses, each of which
2788 must have a controller. At any point in time, only one bus is
2789 active. To switch to a different bus, use the 'i2c dev' command.
2790 Note that bus numbering is zero-based.
2792 CONFIG_SYS_I2C_NOPROBES
2794 This option specifies a list of I2C devices that will be skipped
2795 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2796 is set, specify a list of bus-device pairs. Otherwise, specify
2797 a 1D array of device addresses
2800 #undef CONFIG_I2C_MULTI_BUS
2801 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2803 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2805 #define CONFIG_I2C_MULTI_BUS
2806 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2808 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2810 CONFIG_SYS_SPD_BUS_NUM
2812 If defined, then this indicates the I2C bus number for DDR SPD.
2813 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2815 CONFIG_SYS_RTC_BUS_NUM
2817 If defined, then this indicates the I2C bus number for the RTC.
2818 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2820 CONFIG_SYS_DTT_BUS_NUM
2822 If defined, then this indicates the I2C bus number for the DTT.
2823 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2825 CONFIG_SYS_I2C_DTT_ADDR:
2827 If defined, specifies the I2C address of the DTT device.
2828 If not defined, then U-Boot uses predefined value for
2829 specified DTT device.
2831 CONFIG_SOFT_I2C_READ_REPEATED_START
2833 defining this will force the i2c_read() function in
2834 the soft_i2c driver to perform an I2C repeated start
2835 between writing the address pointer and reading the
2836 data. If this define is omitted the default behaviour
2837 of doing a stop-start sequence will be used. Most I2C
2838 devices can use either method, but some require one or
2841 - SPI Support: CONFIG_SPI
2843 Enables SPI driver (so far only tested with
2844 SPI EEPROM, also an instance works with Crystal A/D and
2845 D/As on the SACSng board)
2849 Enables the driver for SPI controller on SuperH. Currently
2850 only SH7757 is supported.
2854 Enables extended (16-bit) SPI EEPROM addressing.
2855 (symmetrical to CONFIG_I2C_X)
2859 Enables a software (bit-bang) SPI driver rather than
2860 using hardware support. This is a general purpose
2861 driver that only requires three general I/O port pins
2862 (two outputs, one input) to function. If this is
2863 defined, the board configuration must define several
2864 SPI configuration items (port pins to use, etc). For
2865 an example, see include/configs/sacsng.h.
2869 Enables a hardware SPI driver for general-purpose reads
2870 and writes. As with CONFIG_SOFT_SPI, the board configuration
2871 must define a list of chip-select function pointers.
2872 Currently supported on some MPC8xxx processors. For an
2873 example, see include/configs/mpc8349emds.h.
2877 Enables the driver for the SPI controllers on i.MX and MXC
2878 SoCs. Currently i.MX31/35/51 are supported.
2880 CONFIG_SYS_SPI_MXC_WAIT
2881 Timeout for waiting until spi transfer completed.
2882 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2884 - FPGA Support: CONFIG_FPGA
2886 Enables FPGA subsystem.
2888 CONFIG_FPGA_<vendor>
2890 Enables support for specific chip vendors.
2893 CONFIG_FPGA_<family>
2895 Enables support for FPGA family.
2896 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2900 Specify the number of FPGA devices to support.
2902 CONFIG_CMD_FPGA_LOADMK
2904 Enable support for fpga loadmk command
2906 CONFIG_CMD_FPGA_LOADP
2908 Enable support for fpga loadp command - load partial bitstream
2910 CONFIG_CMD_FPGA_LOADBP
2912 Enable support for fpga loadbp command - load partial bitstream
2915 CONFIG_SYS_FPGA_PROG_FEEDBACK
2917 Enable printing of hash marks during FPGA configuration.
2919 CONFIG_SYS_FPGA_CHECK_BUSY
2921 Enable checks on FPGA configuration interface busy
2922 status by the configuration function. This option
2923 will require a board or device specific function to
2928 If defined, a function that provides delays in the FPGA
2929 configuration driver.
2931 CONFIG_SYS_FPGA_CHECK_CTRLC
2932 Allow Control-C to interrupt FPGA configuration
2934 CONFIG_SYS_FPGA_CHECK_ERROR
2936 Check for configuration errors during FPGA bitfile
2937 loading. For example, abort during Virtex II
2938 configuration if the INIT_B line goes low (which
2939 indicated a CRC error).
2941 CONFIG_SYS_FPGA_WAIT_INIT
2943 Maximum time to wait for the INIT_B line to de-assert
2944 after PROB_B has been de-asserted during a Virtex II
2945 FPGA configuration sequence. The default time is 500
2948 CONFIG_SYS_FPGA_WAIT_BUSY
2950 Maximum time to wait for BUSY to de-assert during
2951 Virtex II FPGA configuration. The default is 5 ms.
2953 CONFIG_SYS_FPGA_WAIT_CONFIG
2955 Time to wait after FPGA configuration. The default is
2958 - Configuration Management:
2961 Some SoCs need special image types (e.g. U-Boot binary
2962 with a special header) as build targets. By defining
2963 CONFIG_BUILD_TARGET in the SoC / board header, this
2964 special image will be automatically built upon calling
2969 If defined, this string will be added to the U-Boot
2970 version information (U_BOOT_VERSION)
2972 - Vendor Parameter Protection:
2974 U-Boot considers the values of the environment
2975 variables "serial#" (Board Serial Number) and
2976 "ethaddr" (Ethernet Address) to be parameters that
2977 are set once by the board vendor / manufacturer, and
2978 protects these variables from casual modification by
2979 the user. Once set, these variables are read-only,
2980 and write or delete attempts are rejected. You can
2981 change this behaviour:
2983 If CONFIG_ENV_OVERWRITE is #defined in your config
2984 file, the write protection for vendor parameters is
2985 completely disabled. Anybody can change or delete
2988 Alternatively, if you define _both_ an ethaddr in the
2989 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2990 Ethernet address is installed in the environment,
2991 which can be changed exactly ONCE by the user. [The
2992 serial# is unaffected by this, i. e. it remains
2995 The same can be accomplished in a more flexible way
2996 for any variable by configuring the type of access
2997 to allow for those variables in the ".flags" variable
2998 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3003 Define this variable to enable the reservation of
3004 "protected RAM", i. e. RAM which is not overwritten
3005 by U-Boot. Define CONFIG_PRAM to hold the number of
3006 kB you want to reserve for pRAM. You can overwrite
3007 this default value by defining an environment
3008 variable "pram" to the number of kB you want to
3009 reserve. Note that the board info structure will
3010 still show the full amount of RAM. If pRAM is
3011 reserved, a new environment variable "mem" will
3012 automatically be defined to hold the amount of
3013 remaining RAM in a form that can be passed as boot
3014 argument to Linux, for instance like that:
3016 setenv bootargs ... mem=\${mem}
3019 This way you can tell Linux not to use this memory,
3020 either, which results in a memory region that will
3021 not be affected by reboots.
3023 *WARNING* If your board configuration uses automatic
3024 detection of the RAM size, you must make sure that
3025 this memory test is non-destructive. So far, the
3026 following board configurations are known to be
3029 IVMS8, IVML24, SPD8xx, TQM8xxL,
3030 HERMES, IP860, RPXlite, LWMON,
3033 - Access to physical memory region (> 4GB)
3034 Some basic support is provided for operations on memory not
3035 normally accessible to U-Boot - e.g. some architectures
3036 support access to more than 4GB of memory on 32-bit
3037 machines using physical address extension or similar.
3038 Define CONFIG_PHYSMEM to access this basic support, which
3039 currently only supports clearing the memory.
3044 Define this variable to stop the system in case of a
3045 fatal error, so that you have to reset it manually.
3046 This is probably NOT a good idea for an embedded
3047 system where you want the system to reboot
3048 automatically as fast as possible, but it may be
3049 useful during development since you can try to debug
3050 the conditions that lead to the situation.
3052 CONFIG_NET_RETRY_COUNT
3054 This variable defines the number of retries for
3055 network operations like ARP, RARP, TFTP, or BOOTP
3056 before giving up the operation. If not defined, a
3057 default value of 5 is used.
3061 Timeout waiting for an ARP reply in milliseconds.
3065 Timeout in milliseconds used in NFS protocol.
3066 If you encounter "ERROR: Cannot umount" in nfs command,
3067 try longer timeout such as
3068 #define CONFIG_NFS_TIMEOUT 10000UL
3070 - Command Interpreter:
3071 CONFIG_AUTO_COMPLETE
3073 Enable auto completion of commands using TAB.
3075 CONFIG_SYS_PROMPT_HUSH_PS2
3077 This defines the secondary prompt string, which is
3078 printed when the command interpreter needs more input
3079 to complete a command. Usually "> ".
3083 In the current implementation, the local variables
3084 space and global environment variables space are
3085 separated. Local variables are those you define by
3086 simply typing `name=value'. To access a local
3087 variable later on, you have write `$name' or
3088 `${name}'; to execute the contents of a variable
3089 directly type `$name' at the command prompt.
3091 Global environment variables are those you use
3092 setenv/printenv to work with. To run a command stored
3093 in such a variable, you need to use the run command,
3094 and you must not use the '$' sign to access them.
3096 To store commands and special characters in a
3097 variable, please use double quotation marks
3098 surrounding the whole text of the variable, instead
3099 of the backslashes before semicolons and special
3102 - Command Line Editing and History:
3103 CONFIG_CMDLINE_EDITING
3105 Enable editing and History functions for interactive
3106 command line input operations
3108 - Default Environment:
3109 CONFIG_EXTRA_ENV_SETTINGS
3111 Define this to contain any number of null terminated
3112 strings (variable = value pairs) that will be part of
3113 the default environment compiled into the boot image.
3115 For example, place something like this in your
3116 board's config file:
3118 #define CONFIG_EXTRA_ENV_SETTINGS \
3122 Warning: This method is based on knowledge about the
3123 internal format how the environment is stored by the
3124 U-Boot code. This is NOT an official, exported
3125 interface! Although it is unlikely that this format
3126 will change soon, there is no guarantee either.
3127 You better know what you are doing here.
3129 Note: overly (ab)use of the default environment is
3130 discouraged. Make sure to check other ways to preset
3131 the environment like the "source" command or the
3134 CONFIG_ENV_VARS_UBOOT_CONFIG
3136 Define this in order to add variables describing the
3137 U-Boot build configuration to the default environment.
3138 These will be named arch, cpu, board, vendor, and soc.
3140 Enabling this option will cause the following to be defined:
3148 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3150 Define this in order to add variables describing certain
3151 run-time determined information about the hardware to the
3152 environment. These will be named board_name, board_rev.
3154 CONFIG_DELAY_ENVIRONMENT
3156 Normally the environment is loaded when the board is
3157 initialised so that it is available to U-Boot. This inhibits
3158 that so that the environment is not available until
3159 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3160 this is instead controlled by the value of
3161 /config/load-environment.
3163 - Parallel Flash support:
3166 Traditionally U-boot was run on systems with parallel NOR
3167 flash. This option is used to disable support for parallel NOR
3168 flash. This option should be defined if the board does not have
3171 If this option is not defined one of the generic flash drivers
3172 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3173 selected or the board must provide an implementation of the
3174 flash API (see include/flash.h).
3176 - DataFlash Support:
3177 CONFIG_HAS_DATAFLASH
3179 Defining this option enables DataFlash features and
3180 allows to read/write in Dataflash via the standard
3183 - Serial Flash support
3186 Defining this option enables SPI flash commands
3187 'sf probe/read/write/erase/update'.
3189 Usage requires an initial 'probe' to define the serial
3190 flash parameters, followed by read/write/erase/update
3193 The following defaults may be provided by the platform
3194 to handle the common case when only a single serial
3195 flash is present on the system.
3197 CONFIG_SF_DEFAULT_BUS Bus identifier
3198 CONFIG_SF_DEFAULT_CS Chip-select
3199 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3200 CONFIG_SF_DEFAULT_SPEED in Hz
3204 Define this option to include a destructive SPI flash
3207 CONFIG_SF_DUAL_FLASH Dual flash memorie
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