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!
693 NOTE: The following can be machine specific errata. These
694 do have ability to provide rudimentary version and machine
695 specific checks, but expect no product checks.
696 CONFIG_ARM_ERRATA_430973
697 CONFIG_ARM_ERRATA_454179
698 CONFIG_ARM_ERRATA_621766
699 CONFIG_ARM_ERRATA_798870
702 CONFIG_TEGRA_SUPPORT_NON_SECURE
704 Support executing U-Boot in non-secure (NS) mode. Certain
705 impossible actions will be skipped if the CPU is in NS mode,
706 such as ARM architectural timer initialization.
709 Driver model is a new framework for devices in U-Boot
710 introduced in early 2014. U-Boot is being progressively
711 moved over to this. It offers a consistent device structure,
712 supports grouping devices into classes and has built-in
713 handling of platform data and device tree.
715 To enable transition to driver model in a relatively
716 painful fashion, each subsystem can be independently
717 switched between the legacy/ad-hoc approach and the new
718 driver model using the options below. Also, many uclass
719 interfaces include compatibility features which may be
720 removed once the conversion of that subsystem is complete.
721 As a result, the API provided by the subsystem may in fact
722 not change with driver model.
724 See doc/driver-model/README.txt for more information.
728 Enable driver model. This brings in the core support,
729 including scanning of platform data on start-up. If
730 CONFIG_OF_CONTROL is enabled, the device tree will be
731 scanned also when available.
735 Enable driver model test commands. These allow you to print
736 out the driver model tree and the uclasses.
740 Enable some demo devices and the 'demo' command. These are
741 really only useful for playing around while trying to
742 understand driver model in sandbox.
746 Enable driver model in SPL. You will need to provide a
747 suitable malloc() implementation. If you are not using the
748 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
749 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
750 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
751 In most cases driver model will only allocate a few uclasses
752 and devices in SPL, so 1KB should be enable. See
753 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
758 Enable driver model for serial. This replaces
759 drivers/serial/serial.c with the serial uclass, which
760 implements serial_putc() etc. The uclass interface is
761 defined in include/serial.h.
765 Enable driver model for GPIO access. The standard GPIO
766 interface (gpio_get_value(), etc.) is then implemented by
767 the GPIO uclass. Drivers provide methods to query the
768 particular GPIOs that they provide. The uclass interface
769 is defined in include/asm-generic/gpio.h.
773 Enable driver model for SPI. The SPI slave interface
774 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
775 the SPI uclass. Drivers provide methods to access the SPI
776 buses that they control. The uclass interface is defined in
777 include/spi.h. The existing spi_slave structure is attached
778 as 'parent data' to every slave on each bus. Slaves
779 typically use driver-private data instead of extending the
784 Enable driver model for SPI flash. This SPI flash interface
785 (spi_flash_probe(), spi_flash_write(), etc.) is then
786 implemented by the SPI flash uclass. There is one standard
787 SPI flash driver which knows how to probe most chips
788 supported by U-Boot. The uclass interface is defined in
789 include/spi_flash.h, but is currently fully compatible
790 with the old interface to avoid confusion and duplication
791 during the transition parent. SPI and SPI flash must be
792 enabled together (it is not possible to use driver model
793 for one and not the other).
797 Enable driver model for the Chrome OS EC interface. This
798 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
799 but otherwise makes few changes. Since cros_ec also supports
800 I2C and LPC (which don't support driver model yet), a full
801 conversion is not yet possible.
804 ** Code size options: The following options are enabled by
805 default except in SPL. Enable them explicitly to get these
810 Enable the dm_warn() function. This can use up quite a bit
811 of space for its strings.
815 Enable registering a serial device with the stdio library.
817 CONFIG_DM_DEVICE_REMOVE
819 Enable removing of devices.
821 - Linux Kernel Interface:
824 U-Boot stores all clock information in Hz
825 internally. For binary compatibility with older Linux
826 kernels (which expect the clocks passed in the
827 bd_info data to be in MHz) the environment variable
828 "clocks_in_mhz" can be defined so that U-Boot
829 converts clock data to MHZ before passing it to the
831 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
832 "clocks_in_mhz=1" is automatically included in the
835 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
837 When transferring memsize parameter to Linux, some versions
838 expect it to be in bytes, others in MB.
839 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
843 New kernel versions are expecting firmware settings to be
844 passed using flattened device trees (based on open firmware
848 * New libfdt-based support
849 * Adds the "fdt" command
850 * The bootm command automatically updates the fdt
852 OF_CPU - The proper name of the cpus node (only required for
853 MPC512X and MPC5xxx based boards).
854 OF_SOC - The proper name of the soc node (only required for
855 MPC512X and MPC5xxx based boards).
856 OF_TBCLK - The timebase frequency.
857 OF_STDOUT_PATH - The path to the console device
859 boards with QUICC Engines require OF_QE to set UCC MAC
862 CONFIG_OF_BOARD_SETUP
864 Board code has addition modification that it wants to make
865 to the flat device tree before handing it off to the kernel
867 CONFIG_OF_SYSTEM_SETUP
869 Other code has addition modification that it wants to make
870 to the flat device tree before handing it off to the kernel.
871 This causes ft_system_setup() to be called before booting
876 This define fills in the correct boot CPU in the boot
877 param header, the default value is zero if undefined.
881 U-Boot can detect if an IDE device is present or not.
882 If not, and this new config option is activated, U-Boot
883 removes the ATA node from the DTS before booting Linux,
884 so the Linux IDE driver does not probe the device and
885 crash. This is needed for buggy hardware (uc101) where
886 no pull down resistor is connected to the signal IDE5V_DD7.
888 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
890 This setting is mandatory for all boards that have only one
891 machine type and must be used to specify the machine type
892 number as it appears in the ARM machine registry
893 (see http://www.arm.linux.org.uk/developer/machines/).
894 Only boards that have multiple machine types supported
895 in a single configuration file and the machine type is
896 runtime discoverable, do not have to use this setting.
898 - vxWorks boot parameters:
900 bootvx constructs a valid bootline using the following
901 environments variables: bootfile, ipaddr, serverip, hostname.
902 It loads the vxWorks image pointed bootfile.
904 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
905 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
906 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
907 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
909 CONFIG_SYS_VXWORKS_ADD_PARAMS
911 Add it at the end of the bootline. E.g "u=username pw=secret"
913 Note: If a "bootargs" environment is defined, it will overwride
914 the defaults discussed just above.
916 - Cache Configuration:
917 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
918 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
919 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
921 - Cache Configuration for ARM:
922 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
924 CONFIG_SYS_PL310_BASE - Physical base address of PL310
925 controller register space
930 Define this if you want support for Amba PrimeCell PL010 UARTs.
934 Define this if you want support for Amba PrimeCell PL011 UARTs.
938 If you have Amba PrimeCell PL011 UARTs, set this variable to
939 the clock speed of the UARTs.
943 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
944 define this to a list of base addresses for each (supported)
945 port. See e.g. include/configs/versatile.h
947 CONFIG_PL011_SERIAL_RLCR
949 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
950 have separate receive and transmit line control registers. Set
951 this variable to initialize the extra register.
953 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
955 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
956 boot loader that has already initialized the UART. Define this
957 variable to flush the UART at init time.
959 CONFIG_SERIAL_HW_FLOW_CONTROL
961 Define this variable to enable hw flow control in serial driver.
962 Current user of this option is drivers/serial/nsl16550.c driver
965 Depending on board, define exactly one serial port
966 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
967 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
968 console by defining CONFIG_8xx_CONS_NONE
970 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
971 port routines must be defined elsewhere
972 (i.e. serial_init(), serial_getc(), ...)
975 Enables console device for a color framebuffer. Needs following
976 defines (cf. smiLynxEM, i8042)
977 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
979 VIDEO_HW_RECTFILL graphic chip supports
982 VIDEO_HW_BITBLT graphic chip supports
983 bit-blit (cf. smiLynxEM)
984 VIDEO_VISIBLE_COLS visible pixel columns
986 VIDEO_VISIBLE_ROWS visible pixel rows
987 VIDEO_PIXEL_SIZE bytes per pixel
988 VIDEO_DATA_FORMAT graphic data format
989 (0-5, cf. cfb_console.c)
990 VIDEO_FB_ADRS framebuffer address
991 VIDEO_KBD_INIT_FCT keyboard int fct
992 (i.e. i8042_kbd_init())
993 VIDEO_TSTC_FCT test char fct
995 VIDEO_GETC_FCT get char fct
997 CONFIG_CONSOLE_CURSOR cursor drawing on/off
998 (requires blink timer
1000 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1001 CONFIG_CONSOLE_TIME display time/date info in
1003 (requires CONFIG_CMD_DATE)
1004 CONFIG_VIDEO_LOGO display Linux logo in
1006 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1007 linux_logo.h for logo.
1008 Requires CONFIG_VIDEO_LOGO
1009 CONFIG_CONSOLE_EXTRA_INFO
1010 additional board info beside
1013 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1014 a limited number of ANSI escape sequences (cursor control,
1015 erase functions and limited graphics rendition control).
1017 When CONFIG_CFB_CONSOLE is defined, video console is
1018 default i/o. Serial console can be forced with
1019 environment 'console=serial'.
1021 When CONFIG_SILENT_CONSOLE is defined, all console
1022 messages (by U-Boot and Linux!) can be silenced with
1023 the "silent" environment variable. See
1024 doc/README.silent for more information.
1026 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1028 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1032 CONFIG_BAUDRATE - in bps
1033 Select one of the baudrates listed in
1034 CONFIG_SYS_BAUDRATE_TABLE, see below.
1035 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1037 - Console Rx buffer length
1038 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1039 the maximum receive buffer length for the SMC.
1040 This option is actual only for 82xx and 8xx possible.
1041 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1042 must be defined, to setup the maximum idle timeout for
1045 - Pre-Console Buffer:
1046 Prior to the console being initialised (i.e. serial UART
1047 initialised etc) all console output is silently discarded.
1048 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1049 buffer any console messages prior to the console being
1050 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1051 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1052 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1053 bytes are output before the console is initialised, the
1054 earlier bytes are discarded.
1056 'Sane' compilers will generate smaller code if
1057 CONFIG_PRE_CON_BUF_SZ is a power of 2
1059 - Safe printf() functions
1060 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1061 the printf() functions. These are defined in
1062 include/vsprintf.h and include snprintf(), vsnprintf() and
1063 so on. Code size increase is approximately 300-500 bytes.
1064 If this option is not given then these functions will
1065 silently discard their buffer size argument - this means
1066 you are not getting any overflow checking in this case.
1068 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1069 Delay before automatically booting the default image;
1070 set to -1 to disable autoboot.
1071 set to -2 to autoboot with no delay and not check for abort
1072 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1074 See doc/README.autoboot for these options that
1075 work with CONFIG_BOOTDELAY. None are required.
1076 CONFIG_BOOT_RETRY_TIME
1077 CONFIG_BOOT_RETRY_MIN
1078 CONFIG_AUTOBOOT_KEYED
1079 CONFIG_AUTOBOOT_PROMPT
1080 CONFIG_AUTOBOOT_DELAY_STR
1081 CONFIG_AUTOBOOT_STOP_STR
1082 CONFIG_AUTOBOOT_DELAY_STR2
1083 CONFIG_AUTOBOOT_STOP_STR2
1084 CONFIG_ZERO_BOOTDELAY_CHECK
1085 CONFIG_RESET_TO_RETRY
1089 Only needed when CONFIG_BOOTDELAY is enabled;
1090 define a command string that is automatically executed
1091 when no character is read on the console interface
1092 within "Boot Delay" after reset.
1095 This can be used to pass arguments to the bootm
1096 command. The value of CONFIG_BOOTARGS goes into the
1097 environment value "bootargs".
1099 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1100 The value of these goes into the environment as
1101 "ramboot" and "nfsboot" respectively, and can be used
1102 as a convenience, when switching between booting from
1106 CONFIG_BOOTCOUNT_LIMIT
1107 Implements a mechanism for detecting a repeating reboot
1109 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1111 CONFIG_BOOTCOUNT_ENV
1112 If no softreset save registers are found on the hardware
1113 "bootcount" is stored in the environment. To prevent a
1114 saveenv on all reboots, the environment variable
1115 "upgrade_available" is used. If "upgrade_available" is
1116 0, "bootcount" is always 0, if "upgrade_available" is
1117 1 "bootcount" is incremented in the environment.
1118 So the Userspace Applikation must set the "upgrade_available"
1119 and "bootcount" variable to 0, if a boot was successfully.
1121 - Pre-Boot Commands:
1124 When this option is #defined, the existence of the
1125 environment variable "preboot" will be checked
1126 immediately before starting the CONFIG_BOOTDELAY
1127 countdown and/or running the auto-boot command resp.
1128 entering interactive mode.
1130 This feature is especially useful when "preboot" is
1131 automatically generated or modified. For an example
1132 see the LWMON board specific code: here "preboot" is
1133 modified when the user holds down a certain
1134 combination of keys on the (special) keyboard when
1137 - Serial Download Echo Mode:
1139 If defined to 1, all characters received during a
1140 serial download (using the "loads" command) are
1141 echoed back. This might be needed by some terminal
1142 emulations (like "cu"), but may as well just take
1143 time on others. This setting #define's the initial
1144 value of the "loads_echo" environment variable.
1146 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1147 CONFIG_KGDB_BAUDRATE
1148 Select one of the baudrates listed in
1149 CONFIG_SYS_BAUDRATE_TABLE, see below.
1151 - Monitor Functions:
1152 Monitor commands can be included or excluded
1153 from the build by using the #include files
1154 <config_cmd_all.h> and #undef'ing unwanted
1155 commands, or using <config_cmd_default.h>
1156 and augmenting with additional #define's
1157 for wanted commands.
1159 The default command configuration includes all commands
1160 except those marked below with a "*".
1162 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1163 CONFIG_CMD_ASKENV * ask for env variable
1164 CONFIG_CMD_BDI bdinfo
1165 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1166 CONFIG_CMD_BMP * BMP support
1167 CONFIG_CMD_BSP * Board specific commands
1168 CONFIG_CMD_BOOTD bootd
1169 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1170 CONFIG_CMD_CACHE * icache, dcache
1171 CONFIG_CMD_CLK * clock command support
1172 CONFIG_CMD_CONSOLE coninfo
1173 CONFIG_CMD_CRC32 * crc32
1174 CONFIG_CMD_DATE * support for RTC, date/time...
1175 CONFIG_CMD_DHCP * DHCP support
1176 CONFIG_CMD_DIAG * Diagnostics
1177 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1178 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1179 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1180 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1181 CONFIG_CMD_DTT * Digital Therm and Thermostat
1182 CONFIG_CMD_ECHO echo arguments
1183 CONFIG_CMD_EDITENV edit env variable
1184 CONFIG_CMD_EEPROM * EEPROM read/write support
1185 CONFIG_CMD_ELF * bootelf, bootvx
1186 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1187 CONFIG_CMD_ENV_FLAGS * display details about env flags
1188 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1189 CONFIG_CMD_EXPORTENV * export the environment
1190 CONFIG_CMD_EXT2 * ext2 command support
1191 CONFIG_CMD_EXT4 * ext4 command support
1192 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1193 that work for multiple fs types
1194 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1195 CONFIG_CMD_SAVEENV saveenv
1196 CONFIG_CMD_FDC * Floppy Disk Support
1197 CONFIG_CMD_FAT * FAT command support
1198 CONFIG_CMD_FLASH flinfo, erase, protect
1199 CONFIG_CMD_FPGA FPGA device initialization support
1200 CONFIG_CMD_FUSE * Device fuse support
1201 CONFIG_CMD_GETTIME * Get time since boot
1202 CONFIG_CMD_GO * the 'go' command (exec code)
1203 CONFIG_CMD_GREPENV * search environment
1204 CONFIG_CMD_HASH * calculate hash / digest
1205 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1206 CONFIG_CMD_I2C * I2C serial bus support
1207 CONFIG_CMD_IDE * IDE harddisk support
1208 CONFIG_CMD_IMI iminfo
1209 CONFIG_CMD_IMLS List all images found in NOR flash
1210 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1211 CONFIG_CMD_IMMAP * IMMR dump support
1212 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1213 CONFIG_CMD_IMPORTENV * import an environment
1214 CONFIG_CMD_INI * import data from an ini file into the env
1215 CONFIG_CMD_IRQ * irqinfo
1216 CONFIG_CMD_ITEST Integer/string test of 2 values
1217 CONFIG_CMD_JFFS2 * JFFS2 Support
1218 CONFIG_CMD_KGDB * kgdb
1219 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1220 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1222 CONFIG_CMD_LOADB loadb
1223 CONFIG_CMD_LOADS loads
1224 CONFIG_CMD_MD5SUM * print md5 message digest
1225 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1226 CONFIG_CMD_MEMINFO * Display detailed memory information
1227 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1229 CONFIG_CMD_MEMTEST * mtest
1230 CONFIG_CMD_MISC Misc functions like sleep etc
1231 CONFIG_CMD_MMC * MMC memory mapped support
1232 CONFIG_CMD_MII * MII utility commands
1233 CONFIG_CMD_MTDPARTS * MTD partition support
1234 CONFIG_CMD_NAND * NAND support
1235 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1236 CONFIG_CMD_NFS NFS support
1237 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1238 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1239 CONFIG_CMD_PCI * pciinfo
1240 CONFIG_CMD_PCMCIA * PCMCIA support
1241 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1243 CONFIG_CMD_PORTIO * Port I/O
1244 CONFIG_CMD_READ * Read raw data from partition
1245 CONFIG_CMD_REGINFO * Register dump
1246 CONFIG_CMD_RUN run command in env variable
1247 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1248 CONFIG_CMD_SAVES * save S record dump
1249 CONFIG_CMD_SCSI * SCSI Support
1250 CONFIG_CMD_SDRAM * print SDRAM configuration information
1251 (requires CONFIG_CMD_I2C)
1252 CONFIG_CMD_SETGETDCR Support for DCR Register access
1254 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1255 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1256 (requires CONFIG_CMD_MEMORY)
1257 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1258 CONFIG_CMD_SOURCE "source" command Support
1259 CONFIG_CMD_SPI * SPI serial bus support
1260 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1261 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1262 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1263 CONFIG_CMD_TIMER * access to the system tick timer
1264 CONFIG_CMD_USB * USB support
1265 CONFIG_CMD_CDP * Cisco Discover Protocol support
1266 CONFIG_CMD_MFSL * Microblaze FSL support
1267 CONFIG_CMD_XIMG Load part of Multi Image
1268 CONFIG_CMD_UUID * Generate random UUID or GUID string
1270 EXAMPLE: If you want all functions except of network
1271 support you can write:
1273 #include "config_cmd_all.h"
1274 #undef CONFIG_CMD_NET
1277 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1279 Note: Don't enable the "icache" and "dcache" commands
1280 (configuration option CONFIG_CMD_CACHE) unless you know
1281 what you (and your U-Boot users) are doing. Data
1282 cache cannot be enabled on systems like the 8xx or
1283 8260 (where accesses to the IMMR region must be
1284 uncached), and it cannot be disabled on all other
1285 systems where we (mis-) use the data cache to hold an
1286 initial stack and some data.
1289 XXX - this list needs to get updated!
1291 - Regular expression support:
1293 If this variable is defined, U-Boot is linked against
1294 the SLRE (Super Light Regular Expression) library,
1295 which adds regex support to some commands, as for
1296 example "env grep" and "setexpr".
1300 If this variable is defined, U-Boot will use a device tree
1301 to configure its devices, instead of relying on statically
1302 compiled #defines in the board file. This option is
1303 experimental and only available on a few boards. The device
1304 tree is available in the global data as gd->fdt_blob.
1306 U-Boot needs to get its device tree from somewhere. This can
1307 be done using one of the two options below:
1310 If this variable is defined, U-Boot will embed a device tree
1311 binary in its image. This device tree file should be in the
1312 board directory and called <soc>-<board>.dts. The binary file
1313 is then picked up in board_init_f() and made available through
1314 the global data structure as gd->blob.
1317 If this variable is defined, U-Boot will build a device tree
1318 binary. It will be called u-boot.dtb. Architecture-specific
1319 code will locate it at run-time. Generally this works by:
1321 cat u-boot.bin u-boot.dtb >image.bin
1323 and in fact, U-Boot does this for you, creating a file called
1324 u-boot-dtb.bin which is useful in the common case. You can
1325 still use the individual files if you need something more
1330 If this variable is defined, it enables watchdog
1331 support for the SoC. There must be support in the SoC
1332 specific code for a watchdog. For the 8xx and 8260
1333 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1334 register. When supported for a specific SoC is
1335 available, then no further board specific code should
1336 be needed to use it.
1339 When using a watchdog circuitry external to the used
1340 SoC, then define this variable and provide board
1341 specific code for the "hw_watchdog_reset" function.
1343 CONFIG_AT91_HW_WDT_TIMEOUT
1344 specify the timeout in seconds. default 2 seconds.
1347 CONFIG_VERSION_VARIABLE
1348 If this variable is defined, an environment variable
1349 named "ver" is created by U-Boot showing the U-Boot
1350 version as printed by the "version" command.
1351 Any change to this variable will be reverted at the
1356 When CONFIG_CMD_DATE is selected, the type of the RTC
1357 has to be selected, too. Define exactly one of the
1360 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1361 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1362 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1363 CONFIG_RTC_MC146818 - use MC146818 RTC
1364 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1365 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1366 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1367 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1368 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1369 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1370 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1371 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1372 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1375 Note that if the RTC uses I2C, then the I2C interface
1376 must also be configured. See I2C Support, below.
1379 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1381 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1382 chip-ngpio pairs that tell the PCA953X driver the number of
1383 pins supported by a particular chip.
1385 Note that if the GPIO device uses I2C, then the I2C interface
1386 must also be configured. See I2C Support, below.
1389 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1390 accesses and can checksum them or write a list of them out
1391 to memory. See the 'iotrace' command for details. This is
1392 useful for testing device drivers since it can confirm that
1393 the driver behaves the same way before and after a code
1394 change. Currently this is supported on sandbox and arm. To
1395 add support for your architecture, add '#include <iotrace.h>'
1396 to the bottom of arch/<arch>/include/asm/io.h and test.
1398 Example output from the 'iotrace stats' command is below.
1399 Note that if the trace buffer is exhausted, the checksum will
1400 still continue to operate.
1403 Start: 10000000 (buffer start address)
1404 Size: 00010000 (buffer size)
1405 Offset: 00000120 (current buffer offset)
1406 Output: 10000120 (start + offset)
1407 Count: 00000018 (number of trace records)
1408 CRC32: 9526fb66 (CRC32 of all trace records)
1410 - Timestamp Support:
1412 When CONFIG_TIMESTAMP is selected, the timestamp
1413 (date and time) of an image is printed by image
1414 commands like bootm or iminfo. This option is
1415 automatically enabled when you select CONFIG_CMD_DATE .
1417 - Partition Labels (disklabels) Supported:
1418 Zero or more of the following:
1419 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1420 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1421 Intel architecture, USB sticks, etc.
1422 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1423 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1424 bootloader. Note 2TB partition limit; see
1426 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1428 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1429 CONFIG_CMD_SCSI) you must configure support for at
1430 least one non-MTD partition type as well.
1433 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1434 board configurations files but used nowhere!
1436 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1437 be performed by calling the function
1438 ide_set_reset(int reset)
1439 which has to be defined in a board specific file
1444 Set this to enable ATAPI support.
1449 Set this to enable support for disks larger than 137GB
1450 Also look at CONFIG_SYS_64BIT_LBA.
1451 Whithout these , LBA48 support uses 32bit variables and will 'only'
1452 support disks up to 2.1TB.
1454 CONFIG_SYS_64BIT_LBA:
1455 When enabled, makes the IDE subsystem use 64bit sector addresses.
1459 At the moment only there is only support for the
1460 SYM53C8XX SCSI controller; define
1461 CONFIG_SCSI_SYM53C8XX to enable it.
1463 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1464 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1465 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1466 maximum numbers of LUNs, SCSI ID's and target
1468 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1470 The environment variable 'scsidevs' is set to the number of
1471 SCSI devices found during the last scan.
1473 - NETWORK Support (PCI):
1475 Support for Intel 8254x/8257x gigabit chips.
1478 Utility code for direct access to the SPI bus on Intel 8257x.
1479 This does not do anything useful unless you set at least one
1480 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1482 CONFIG_E1000_SPI_GENERIC
1483 Allow generic access to the SPI bus on the Intel 8257x, for
1484 example with the "sspi" command.
1487 Management command for E1000 devices. When used on devices
1488 with SPI support you can reprogram the EEPROM from U-Boot.
1490 CONFIG_E1000_FALLBACK_MAC
1491 default MAC for empty EEPROM after production.
1494 Support for Intel 82557/82559/82559ER chips.
1495 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1496 write routine for first time initialisation.
1499 Support for Digital 2114x chips.
1500 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1501 modem chip initialisation (KS8761/QS6611).
1504 Support for National dp83815 chips.
1507 Support for National dp8382[01] gigabit chips.
1509 - NETWORK Support (other):
1511 CONFIG_DRIVER_AT91EMAC
1512 Support for AT91RM9200 EMAC.
1515 Define this to use reduced MII inteface
1517 CONFIG_DRIVER_AT91EMAC_QUIET
1518 If this defined, the driver is quiet.
1519 The driver doen't show link status messages.
1521 CONFIG_CALXEDA_XGMAC
1522 Support for the Calxeda XGMAC device
1525 Support for SMSC's LAN91C96 chips.
1527 CONFIG_LAN91C96_BASE
1528 Define this to hold the physical address
1529 of the LAN91C96's I/O space
1531 CONFIG_LAN91C96_USE_32_BIT
1532 Define this to enable 32 bit addressing
1535 Support for SMSC's LAN91C111 chip
1537 CONFIG_SMC91111_BASE
1538 Define this to hold the physical address
1539 of the device (I/O space)
1541 CONFIG_SMC_USE_32_BIT
1542 Define this if data bus is 32 bits
1544 CONFIG_SMC_USE_IOFUNCS
1545 Define this to use i/o functions instead of macros
1546 (some hardware wont work with macros)
1548 CONFIG_DRIVER_TI_EMAC
1549 Support for davinci emac
1551 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1552 Define this if you have more then 3 PHYs.
1555 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1557 CONFIG_FTGMAC100_EGIGA
1558 Define this to use GE link update with gigabit PHY.
1559 Define this if FTGMAC100 is connected to gigabit PHY.
1560 If your system has 10/100 PHY only, it might not occur
1561 wrong behavior. Because PHY usually return timeout or
1562 useless data when polling gigabit status and gigabit
1563 control registers. This behavior won't affect the
1564 correctnessof 10/100 link speed update.
1567 Support for SMSC's LAN911x and LAN921x chips
1570 Define this to hold the physical address
1571 of the device (I/O space)
1573 CONFIG_SMC911X_32_BIT
1574 Define this if data bus is 32 bits
1576 CONFIG_SMC911X_16_BIT
1577 Define this if data bus is 16 bits. If your processor
1578 automatically converts one 32 bit word to two 16 bit
1579 words you may also try CONFIG_SMC911X_32_BIT.
1582 Support for Renesas on-chip Ethernet controller
1584 CONFIG_SH_ETHER_USE_PORT
1585 Define the number of ports to be used
1587 CONFIG_SH_ETHER_PHY_ADDR
1588 Define the ETH PHY's address
1590 CONFIG_SH_ETHER_CACHE_WRITEBACK
1591 If this option is set, the driver enables cache flush.
1595 Support for PWM modul on the imx6.
1599 Support TPM devices.
1602 Support for i2c bus TPM devices. Only one device
1603 per system is supported at this time.
1605 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1606 Define the the i2c bus number for the TPM device
1608 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1609 Define the TPM's address on the i2c bus
1611 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1612 Define the burst count bytes upper limit
1614 CONFIG_TPM_ATMEL_TWI
1615 Support for Atmel TWI TPM device. Requires I2C support.
1618 Support for generic parallel port TPM devices. Only one device
1619 per system is supported at this time.
1621 CONFIG_TPM_TIS_BASE_ADDRESS
1622 Base address where the generic TPM device is mapped
1623 to. Contemporary x86 systems usually map it at
1627 Add tpm monitor functions.
1628 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1629 provides monitor access to authorized functions.
1632 Define this to enable the TPM support library which provides
1633 functional interfaces to some TPM commands.
1634 Requires support for a TPM device.
1636 CONFIG_TPM_AUTH_SESSIONS
1637 Define this to enable authorized functions in the TPM library.
1638 Requires CONFIG_TPM and CONFIG_SHA1.
1641 At the moment only the UHCI host controller is
1642 supported (PIP405, MIP405, MPC5200); define
1643 CONFIG_USB_UHCI to enable it.
1644 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1645 and define CONFIG_USB_STORAGE to enable the USB
1648 Supported are USB Keyboards and USB Floppy drives
1650 MPC5200 USB requires additional defines:
1652 for 528 MHz Clock: 0x0001bbbb
1656 for differential drivers: 0x00001000
1657 for single ended drivers: 0x00005000
1658 for differential drivers on PSC3: 0x00000100
1659 for single ended drivers on PSC3: 0x00004100
1660 CONFIG_SYS_USB_EVENT_POLL
1661 May be defined to allow interrupt polling
1662 instead of using asynchronous interrupts
1664 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1665 txfilltuning field in the EHCI controller on reset.
1667 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1668 HW module registers.
1671 Define the below if you wish to use the USB console.
1672 Once firmware is rebuilt from a serial console issue the
1673 command "setenv stdin usbtty; setenv stdout usbtty" and
1674 attach your USB cable. The Unix command "dmesg" should print
1675 it has found a new device. The environment variable usbtty
1676 can be set to gserial or cdc_acm to enable your device to
1677 appear to a USB host as a Linux gserial device or a
1678 Common Device Class Abstract Control Model serial device.
1679 If you select usbtty = gserial you should be able to enumerate
1681 # modprobe usbserial vendor=0xVendorID product=0xProductID
1682 else if using cdc_acm, simply setting the environment
1683 variable usbtty to be cdc_acm should suffice. The following
1684 might be defined in YourBoardName.h
1687 Define this to build a UDC device
1690 Define this to have a tty type of device available to
1691 talk to the UDC device
1694 Define this to enable the high speed support for usb
1695 device and usbtty. If this feature is enabled, a routine
1696 int is_usbd_high_speed(void)
1697 also needs to be defined by the driver to dynamically poll
1698 whether the enumeration has succeded at high speed or full
1701 CONFIG_SYS_CONSOLE_IS_IN_ENV
1702 Define this if you want stdin, stdout &/or stderr to
1706 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1707 Derive USB clock from external clock "blah"
1708 - CONFIG_SYS_USB_EXTC_CLK 0x02
1710 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1711 Derive USB clock from brgclk
1712 - CONFIG_SYS_USB_BRG_CLK 0x04
1714 If you have a USB-IF assigned VendorID then you may wish to
1715 define your own vendor specific values either in BoardName.h
1716 or directly in usbd_vendor_info.h. If you don't define
1717 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1718 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1719 should pretend to be a Linux device to it's target host.
1721 CONFIG_USBD_MANUFACTURER
1722 Define this string as the name of your company for
1723 - CONFIG_USBD_MANUFACTURER "my company"
1725 CONFIG_USBD_PRODUCT_NAME
1726 Define this string as the name of your product
1727 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1729 CONFIG_USBD_VENDORID
1730 Define this as your assigned Vendor ID from the USB
1731 Implementors Forum. This *must* be a genuine Vendor ID
1732 to avoid polluting the USB namespace.
1733 - CONFIG_USBD_VENDORID 0xFFFF
1735 CONFIG_USBD_PRODUCTID
1736 Define this as the unique Product ID
1738 - CONFIG_USBD_PRODUCTID 0xFFFF
1740 - ULPI Layer Support:
1741 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1742 the generic ULPI layer. The generic layer accesses the ULPI PHY
1743 via the platform viewport, so you need both the genric layer and
1744 the viewport enabled. Currently only Chipidea/ARC based
1745 viewport is supported.
1746 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1747 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1748 If your ULPI phy needs a different reference clock than the
1749 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1750 the appropriate value in Hz.
1753 The MMC controller on the Intel PXA is supported. To
1754 enable this define CONFIG_MMC. The MMC can be
1755 accessed from the boot prompt by mapping the device
1756 to physical memory similar to flash. Command line is
1757 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1758 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1761 Support for Renesas on-chip MMCIF controller
1763 CONFIG_SH_MMCIF_ADDR
1764 Define the base address of MMCIF registers
1767 Define the clock frequency for MMCIF
1770 Enable the generic MMC driver
1772 CONFIG_SUPPORT_EMMC_BOOT
1773 Enable some additional features of the eMMC boot partitions.
1775 CONFIG_SUPPORT_EMMC_RPMB
1776 Enable the commands for reading, writing and programming the
1777 key for the Replay Protection Memory Block partition in eMMC.
1779 - USB Device Firmware Update (DFU) class support:
1781 This enables the USB portion of the DFU USB class
1784 This enables the command "dfu" which is used to have
1785 U-Boot create a DFU class device via USB. This command
1786 requires that the "dfu_alt_info" environment variable be
1787 set and define the alt settings to expose to the host.
1790 This enables support for exposing (e)MMC devices via DFU.
1793 This enables support for exposing NAND devices via DFU.
1796 This enables support for exposing RAM via DFU.
1797 Note: DFU spec refer to non-volatile memory usage, but
1798 allow usages beyond the scope of spec - here RAM usage,
1799 one that would help mostly the developer.
1801 CONFIG_SYS_DFU_DATA_BUF_SIZE
1802 Dfu transfer uses a buffer before writing data to the
1803 raw storage device. Make the size (in bytes) of this buffer
1804 configurable. The size of this buffer is also configurable
1805 through the "dfu_bufsiz" environment variable.
1807 CONFIG_SYS_DFU_MAX_FILE_SIZE
1808 When updating files rather than the raw storage device,
1809 we use a static buffer to copy the file into and then write
1810 the buffer once we've been given the whole file. Define
1811 this to the maximum filesize (in bytes) for the buffer.
1812 Default is 4 MiB if undefined.
1814 DFU_DEFAULT_POLL_TIMEOUT
1815 Poll timeout [ms], is the timeout a device can send to the
1816 host. The host must wait for this timeout before sending
1817 a subsequent DFU_GET_STATUS request to the device.
1819 DFU_MANIFEST_POLL_TIMEOUT
1820 Poll timeout [ms], which the device sends to the host when
1821 entering dfuMANIFEST state. Host waits this timeout, before
1822 sending again an USB request to the device.
1824 - USB Device Android Fastboot support:
1826 This enables the command "fastboot" which enables the Android
1827 fastboot mode for the platform's USB device. Fastboot is a USB
1828 protocol for downloading images, flashing and device control
1829 used on Android devices.
1830 See doc/README.android-fastboot for more information.
1832 CONFIG_ANDROID_BOOT_IMAGE
1833 This enables support for booting images which use the Android
1834 image format header.
1836 CONFIG_USB_FASTBOOT_BUF_ADDR
1837 The fastboot protocol requires a large memory buffer for
1838 downloads. Define this to the starting RAM address to use for
1841 CONFIG_USB_FASTBOOT_BUF_SIZE
1842 The fastboot protocol requires a large memory buffer for
1843 downloads. This buffer should be as large as possible for a
1844 platform. Define this to the size available RAM for fastboot.
1846 CONFIG_FASTBOOT_FLASH
1847 The fastboot protocol includes a "flash" command for writing
1848 the downloaded image to a non-volatile storage device. Define
1849 this to enable the "fastboot flash" command.
1851 CONFIG_FASTBOOT_FLASH_MMC_DEV
1852 The fastboot "flash" command requires additional information
1853 regarding the non-volatile storage device. Define this to
1854 the eMMC device that fastboot should use to store the image.
1856 CONFIG_FASTBOOT_GPT_NAME
1857 The fastboot "flash" command supports writing the downloaded
1858 image to the Protective MBR and the Primary GUID Partition
1859 Table. (Additionally, this downloaded image is post-processed
1860 to generate and write the Backup GUID Partition Table.)
1861 This occurs when the specified "partition name" on the
1862 "fastboot flash" command line matches this value.
1863 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1865 - Journaling Flash filesystem support:
1866 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1867 CONFIG_JFFS2_NAND_DEV
1868 Define these for a default partition on a NAND device
1870 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1871 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1872 Define these for a default partition on a NOR device
1874 CONFIG_SYS_JFFS_CUSTOM_PART
1875 Define this to create an own partition. You have to provide a
1876 function struct part_info* jffs2_part_info(int part_num)
1878 If you define only one JFFS2 partition you may also want to
1879 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1880 to disable the command chpart. This is the default when you
1881 have not defined a custom partition
1883 - FAT(File Allocation Table) filesystem write function support:
1886 Define this to enable support for saving memory data as a
1887 file in FAT formatted partition.
1889 This will also enable the command "fatwrite" enabling the
1890 user to write files to FAT.
1892 CBFS (Coreboot Filesystem) support
1895 Define this to enable support for reading from a Coreboot
1896 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1899 - FAT(File Allocation Table) filesystem cluster size:
1900 CONFIG_FS_FAT_MAX_CLUSTSIZE
1902 Define the max cluster size for fat operations else
1903 a default value of 65536 will be defined.
1908 Define this to enable standard (PC-Style) keyboard
1912 Standard PC keyboard driver with US (is default) and
1913 GERMAN key layout (switch via environment 'keymap=de') support.
1914 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1915 for cfb_console. Supports cursor blinking.
1918 Enables a Chrome OS keyboard using the CROS_EC interface.
1919 This uses CROS_EC to communicate with a second microcontroller
1920 which provides key scans on request.
1925 Define this to enable video support (for output to
1928 CONFIG_VIDEO_CT69000
1930 Enable Chips & Technologies 69000 Video chip
1932 CONFIG_VIDEO_SMI_LYNXEM
1933 Enable Silicon Motion SMI 712/710/810 Video chip. The
1934 video output is selected via environment 'videoout'
1935 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1938 For the CT69000 and SMI_LYNXEM drivers, videomode is
1939 selected via environment 'videomode'. Two different ways
1941 - "videomode=num" 'num' is a standard LiLo mode numbers.
1942 Following standard modes are supported (* is default):
1944 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1945 -------------+---------------------------------------------
1946 8 bits | 0x301* 0x303 0x305 0x161 0x307
1947 15 bits | 0x310 0x313 0x316 0x162 0x319
1948 16 bits | 0x311 0x314 0x317 0x163 0x31A
1949 24 bits | 0x312 0x315 0x318 ? 0x31B
1950 -------------+---------------------------------------------
1951 (i.e. setenv videomode 317; saveenv; reset;)
1953 - "videomode=bootargs" all the video parameters are parsed
1954 from the bootargs. (See drivers/video/videomodes.c)
1957 CONFIG_VIDEO_SED13806
1958 Enable Epson SED13806 driver. This driver supports 8bpp
1959 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1960 or CONFIG_VIDEO_SED13806_16BPP
1963 Enable the Freescale DIU video driver. Reference boards for
1964 SOCs that have a DIU should define this macro to enable DIU
1965 support, and should also define these other macros:
1971 CONFIG_VIDEO_SW_CURSOR
1972 CONFIG_VGA_AS_SINGLE_DEVICE
1974 CONFIG_VIDEO_BMP_LOGO
1976 The DIU driver will look for the 'video-mode' environment
1977 variable, and if defined, enable the DIU as a console during
1978 boot. See the documentation file README.video for a
1979 description of this variable.
1983 Enable the VGA video / BIOS for x86. The alternative if you
1984 are using coreboot is to use the coreboot frame buffer
1991 Define this to enable a custom keyboard support.
1992 This simply calls drv_keyboard_init() which must be
1993 defined in your board-specific files.
1994 The only board using this so far is RBC823.
1996 - LCD Support: CONFIG_LCD
1998 Define this to enable LCD support (for output to LCD
1999 display); also select one of the supported displays
2000 by defining one of these:
2004 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2006 CONFIG_NEC_NL6448AC33:
2008 NEC NL6448AC33-18. Active, color, single scan.
2010 CONFIG_NEC_NL6448BC20
2012 NEC NL6448BC20-08. 6.5", 640x480.
2013 Active, color, single scan.
2015 CONFIG_NEC_NL6448BC33_54
2017 NEC NL6448BC33-54. 10.4", 640x480.
2018 Active, color, single scan.
2022 Sharp 320x240. Active, color, single scan.
2023 It isn't 16x9, and I am not sure what it is.
2025 CONFIG_SHARP_LQ64D341
2027 Sharp LQ64D341 display, 640x480.
2028 Active, color, single scan.
2032 HLD1045 display, 640x480.
2033 Active, color, single scan.
2037 Optrex CBL50840-2 NF-FW 99 22 M5
2039 Hitachi LMG6912RPFC-00T
2043 320x240. Black & white.
2045 Normally display is black on white background; define
2046 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2048 CONFIG_LCD_ALIGNMENT
2050 Normally the LCD is page-aligned (typically 4KB). If this is
2051 defined then the LCD will be aligned to this value instead.
2052 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2053 here, since it is cheaper to change data cache settings on
2054 a per-section basis.
2056 CONFIG_CONSOLE_SCROLL_LINES
2058 When the console need to be scrolled, this is the number of
2059 lines to scroll by. It defaults to 1. Increasing this makes
2060 the console jump but can help speed up operation when scrolling
2065 Support drawing of RLE8-compressed bitmaps on the LCD.
2069 Enables an 'i2c edid' command which can read EDID
2070 information over I2C from an attached LCD display.
2072 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2074 If this option is set, the environment is checked for
2075 a variable "splashimage". If found, the usual display
2076 of logo, copyright and system information on the LCD
2077 is suppressed and the BMP image at the address
2078 specified in "splashimage" is loaded instead. The
2079 console is redirected to the "nulldev", too. This
2080 allows for a "silent" boot where a splash screen is
2081 loaded very quickly after power-on.
2083 CONFIG_SPLASHIMAGE_GUARD
2085 If this option is set, then U-Boot will prevent the environment
2086 variable "splashimage" from being set to a problematic address
2087 (see README.displaying-bmps).
2088 This option is useful for targets where, due to alignment
2089 restrictions, an improperly aligned BMP image will cause a data
2090 abort. If you think you will not have problems with unaligned
2091 accesses (for example because your toolchain prevents them)
2092 there is no need to set this option.
2094 CONFIG_SPLASH_SCREEN_ALIGN
2096 If this option is set the splash image can be freely positioned
2097 on the screen. Environment variable "splashpos" specifies the
2098 position as "x,y". If a positive number is given it is used as
2099 number of pixel from left/top. If a negative number is given it
2100 is used as number of pixel from right/bottom. You can also
2101 specify 'm' for centering the image.
2104 setenv splashpos m,m
2105 => image at center of screen
2107 setenv splashpos 30,20
2108 => image at x = 30 and y = 20
2110 setenv splashpos -10,m
2111 => vertically centered image
2112 at x = dspWidth - bmpWidth - 9
2114 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2116 If this option is set, additionally to standard BMP
2117 images, gzipped BMP images can be displayed via the
2118 splashscreen support or the bmp command.
2120 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2122 If this option is set, 8-bit RLE compressed BMP images
2123 can be displayed via the splashscreen support or the
2126 - Do compressing for memory range:
2129 If this option is set, it would use zlib deflate method
2130 to compress the specified memory at its best effort.
2132 - Compression support:
2135 Enabled by default to support gzip compressed images.
2139 If this option is set, support for bzip2 compressed
2140 images is included. If not, only uncompressed and gzip
2141 compressed images are supported.
2143 NOTE: the bzip2 algorithm requires a lot of RAM, so
2144 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2149 If this option is set, support for lzma compressed
2152 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2153 requires an amount of dynamic memory that is given by the
2156 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2158 Where lc and lp stand for, respectively, Literal context bits
2159 and Literal pos bits.
2161 This value is upper-bounded by 14MB in the worst case. Anyway,
2162 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2163 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2164 a very small buffer.
2166 Use the lzmainfo tool to determinate the lc and lp values and
2167 then calculate the amount of needed dynamic memory (ensuring
2168 the appropriate CONFIG_SYS_MALLOC_LEN value).
2172 If this option is set, support for LZO compressed images
2178 The address of PHY on MII bus.
2180 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2182 The clock frequency of the MII bus
2186 If this option is set, support for speed/duplex
2187 detection of gigabit PHY is included.
2189 CONFIG_PHY_RESET_DELAY
2191 Some PHY like Intel LXT971A need extra delay after
2192 reset before any MII register access is possible.
2193 For such PHY, set this option to the usec delay
2194 required. (minimum 300usec for LXT971A)
2196 CONFIG_PHY_CMD_DELAY (ppc4xx)
2198 Some PHY like Intel LXT971A need extra delay after
2199 command issued before MII status register can be read
2209 Define a default value for Ethernet address to use
2210 for the respective Ethernet interface, in case this
2211 is not determined automatically.
2216 Define a default value for the IP address to use for
2217 the default Ethernet interface, in case this is not
2218 determined through e.g. bootp.
2219 (Environment variable "ipaddr")
2221 - Server IP address:
2224 Defines a default value for the IP address of a TFTP
2225 server to contact when using the "tftboot" command.
2226 (Environment variable "serverip")
2228 CONFIG_KEEP_SERVERADDR
2230 Keeps the server's MAC address, in the env 'serveraddr'
2231 for passing to bootargs (like Linux's netconsole option)
2233 - Gateway IP address:
2236 Defines a default value for the IP address of the
2237 default router where packets to other networks are
2239 (Environment variable "gatewayip")
2244 Defines a default value for the subnet mask (or
2245 routing prefix) which is used to determine if an IP
2246 address belongs to the local subnet or needs to be
2247 forwarded through a router.
2248 (Environment variable "netmask")
2250 - Multicast TFTP Mode:
2253 Defines whether you want to support multicast TFTP as per
2254 rfc-2090; for example to work with atftp. Lets lots of targets
2255 tftp down the same boot image concurrently. Note: the Ethernet
2256 driver in use must provide a function: mcast() to join/leave a
2259 - BOOTP Recovery Mode:
2260 CONFIG_BOOTP_RANDOM_DELAY
2262 If you have many targets in a network that try to
2263 boot using BOOTP, you may want to avoid that all
2264 systems send out BOOTP requests at precisely the same
2265 moment (which would happen for instance at recovery
2266 from a power failure, when all systems will try to
2267 boot, thus flooding the BOOTP server. Defining
2268 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2269 inserted before sending out BOOTP requests. The
2270 following delays are inserted then:
2272 1st BOOTP request: delay 0 ... 1 sec
2273 2nd BOOTP request: delay 0 ... 2 sec
2274 3rd BOOTP request: delay 0 ... 4 sec
2276 BOOTP requests: delay 0 ... 8 sec
2278 CONFIG_BOOTP_ID_CACHE_SIZE
2280 BOOTP packets are uniquely identified using a 32-bit ID. The
2281 server will copy the ID from client requests to responses and
2282 U-Boot will use this to determine if it is the destination of
2283 an incoming response. Some servers will check that addresses
2284 aren't in use before handing them out (usually using an ARP
2285 ping) and therefore take up to a few hundred milliseconds to
2286 respond. Network congestion may also influence the time it
2287 takes for a response to make it back to the client. If that
2288 time is too long, U-Boot will retransmit requests. In order
2289 to allow earlier responses to still be accepted after these
2290 retransmissions, U-Boot's BOOTP client keeps a small cache of
2291 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2292 cache. The default is to keep IDs for up to four outstanding
2293 requests. Increasing this will allow U-Boot to accept offers
2294 from a BOOTP client in networks with unusually high latency.
2296 - DHCP Advanced Options:
2297 You can fine tune the DHCP functionality by defining
2298 CONFIG_BOOTP_* symbols:
2300 CONFIG_BOOTP_SUBNETMASK
2301 CONFIG_BOOTP_GATEWAY
2302 CONFIG_BOOTP_HOSTNAME
2303 CONFIG_BOOTP_NISDOMAIN
2304 CONFIG_BOOTP_BOOTPATH
2305 CONFIG_BOOTP_BOOTFILESIZE
2308 CONFIG_BOOTP_SEND_HOSTNAME
2309 CONFIG_BOOTP_NTPSERVER
2310 CONFIG_BOOTP_TIMEOFFSET
2311 CONFIG_BOOTP_VENDOREX
2312 CONFIG_BOOTP_MAY_FAIL
2314 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2315 environment variable, not the BOOTP server.
2317 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2318 after the configured retry count, the call will fail
2319 instead of starting over. This can be used to fail over
2320 to Link-local IP address configuration if the DHCP server
2323 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2324 serverip from a DHCP server, it is possible that more
2325 than one DNS serverip is offered to the client.
2326 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2327 serverip will be stored in the additional environment
2328 variable "dnsip2". The first DNS serverip is always
2329 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2332 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2333 to do a dynamic update of a DNS server. To do this, they
2334 need the hostname of the DHCP requester.
2335 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2336 of the "hostname" environment variable is passed as
2337 option 12 to the DHCP server.
2339 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2341 A 32bit value in microseconds for a delay between
2342 receiving a "DHCP Offer" and sending the "DHCP Request".
2343 This fixes a problem with certain DHCP servers that don't
2344 respond 100% of the time to a "DHCP request". E.g. On an
2345 AT91RM9200 processor running at 180MHz, this delay needed
2346 to be *at least* 15,000 usec before a Windows Server 2003
2347 DHCP server would reply 100% of the time. I recommend at
2348 least 50,000 usec to be safe. The alternative is to hope
2349 that one of the retries will be successful but note that
2350 the DHCP timeout and retry process takes a longer than
2353 - Link-local IP address negotiation:
2354 Negotiate with other link-local clients on the local network
2355 for an address that doesn't require explicit configuration.
2356 This is especially useful if a DHCP server cannot be guaranteed
2357 to exist in all environments that the device must operate.
2359 See doc/README.link-local for more information.
2362 CONFIG_CDP_DEVICE_ID
2364 The device id used in CDP trigger frames.
2366 CONFIG_CDP_DEVICE_ID_PREFIX
2368 A two character string which is prefixed to the MAC address
2373 A printf format string which contains the ascii name of
2374 the port. Normally is set to "eth%d" which sets
2375 eth0 for the first Ethernet, eth1 for the second etc.
2377 CONFIG_CDP_CAPABILITIES
2379 A 32bit integer which indicates the device capabilities;
2380 0x00000010 for a normal host which does not forwards.
2384 An ascii string containing the version of the software.
2388 An ascii string containing the name of the platform.
2392 A 32bit integer sent on the trigger.
2394 CONFIG_CDP_POWER_CONSUMPTION
2396 A 16bit integer containing the power consumption of the
2397 device in .1 of milliwatts.
2399 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2401 A byte containing the id of the VLAN.
2403 - Status LED: CONFIG_STATUS_LED
2405 Several configurations allow to display the current
2406 status using a LED. For instance, the LED will blink
2407 fast while running U-Boot code, stop blinking as
2408 soon as a reply to a BOOTP request was received, and
2409 start blinking slow once the Linux kernel is running
2410 (supported by a status LED driver in the Linux
2411 kernel). Defining CONFIG_STATUS_LED enables this
2417 The status LED can be connected to a GPIO pin.
2418 In such cases, the gpio_led driver can be used as a
2419 status LED backend implementation. Define CONFIG_GPIO_LED
2420 to include the gpio_led driver in the U-Boot binary.
2422 CONFIG_GPIO_LED_INVERTED_TABLE
2423 Some GPIO connected LEDs may have inverted polarity in which
2424 case the GPIO high value corresponds to LED off state and
2425 GPIO low value corresponds to LED on state.
2426 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2427 with a list of GPIO LEDs that have inverted polarity.
2429 - CAN Support: CONFIG_CAN_DRIVER
2431 Defining CONFIG_CAN_DRIVER enables CAN driver support
2432 on those systems that support this (optional)
2433 feature, like the TQM8xxL modules.
2435 - I2C Support: CONFIG_SYS_I2C
2437 This enable the NEW i2c subsystem, and will allow you to use
2438 i2c commands at the u-boot command line (as long as you set
2439 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2440 based realtime clock chips or other i2c devices. See
2441 common/cmd_i2c.c for a description of the command line
2444 ported i2c driver to the new framework:
2445 - drivers/i2c/soft_i2c.c:
2446 - activate first bus with CONFIG_SYS_I2C_SOFT define
2447 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2448 for defining speed and slave address
2449 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2450 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2451 for defining speed and slave address
2452 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2453 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2454 for defining speed and slave address
2455 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2456 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2457 for defining speed and slave address
2459 - drivers/i2c/fsl_i2c.c:
2460 - activate i2c driver with CONFIG_SYS_I2C_FSL
2461 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2462 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2463 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2465 - If your board supports a second fsl i2c bus, define
2466 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2467 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2468 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2471 - drivers/i2c/tegra_i2c.c:
2472 - activate this driver with CONFIG_SYS_I2C_TEGRA
2473 - This driver adds 4 i2c buses with a fix speed from
2474 100000 and the slave addr 0!
2476 - drivers/i2c/ppc4xx_i2c.c
2477 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2478 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2479 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2481 - drivers/i2c/i2c_mxc.c
2482 - activate this driver with CONFIG_SYS_I2C_MXC
2483 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2484 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2485 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2486 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2487 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2488 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2489 If those defines are not set, default value is 100000
2490 for speed, and 0 for slave.
2492 - drivers/i2c/rcar_i2c.c:
2493 - activate this driver with CONFIG_SYS_I2C_RCAR
2494 - This driver adds 4 i2c buses
2496 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2497 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2498 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2499 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2500 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2501 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2502 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2503 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2504 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2506 - drivers/i2c/sh_i2c.c:
2507 - activate this driver with CONFIG_SYS_I2C_SH
2508 - This driver adds from 2 to 5 i2c buses
2510 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2511 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2512 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2513 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2514 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2515 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2516 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2517 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2518 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2519 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2520 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2521 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2522 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2524 - drivers/i2c/omap24xx_i2c.c
2525 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2526 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2527 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2528 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2529 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2530 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2531 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2532 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2533 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2534 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2535 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2537 - drivers/i2c/zynq_i2c.c
2538 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2539 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2540 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2542 - drivers/i2c/s3c24x0_i2c.c:
2543 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2544 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2545 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2546 with a fix speed from 100000 and the slave addr 0!
2548 - drivers/i2c/ihs_i2c.c
2549 - activate this driver with CONFIG_SYS_I2C_IHS
2550 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2551 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2552 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2553 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2554 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2555 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2556 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2557 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2558 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2559 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2560 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2561 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2565 CONFIG_SYS_NUM_I2C_BUSES
2566 Hold the number of i2c buses you want to use. If you
2567 don't use/have i2c muxes on your i2c bus, this
2568 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2571 CONFIG_SYS_I2C_DIRECT_BUS
2572 define this, if you don't use i2c muxes on your hardware.
2573 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2576 CONFIG_SYS_I2C_MAX_HOPS
2577 define how many muxes are maximal consecutively connected
2578 on one i2c bus. If you not use i2c muxes, omit this
2581 CONFIG_SYS_I2C_BUSES
2582 hold a list of buses you want to use, only used if
2583 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2584 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2585 CONFIG_SYS_NUM_I2C_BUSES = 9:
2587 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2588 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2589 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2590 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2591 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2592 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2593 {1, {I2C_NULL_HOP}}, \
2594 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2595 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2599 bus 0 on adapter 0 without a mux
2600 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2601 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2602 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2603 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2604 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2605 bus 6 on adapter 1 without a mux
2606 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2607 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2609 If you do not have i2c muxes on your board, omit this define.
2611 - Legacy I2C Support: CONFIG_HARD_I2C
2613 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2614 provides the following compelling advantages:
2616 - more than one i2c adapter is usable
2617 - approved multibus support
2618 - better i2c mux support
2620 ** Please consider updating your I2C driver now. **
2622 These enable legacy I2C serial bus commands. Defining
2623 CONFIG_HARD_I2C will include the appropriate I2C driver
2624 for the selected CPU.
2626 This will allow you to use i2c commands at the u-boot
2627 command line (as long as you set CONFIG_CMD_I2C in
2628 CONFIG_COMMANDS) and communicate with i2c based realtime
2629 clock chips. See common/cmd_i2c.c for a description of the
2630 command line interface.
2632 CONFIG_HARD_I2C selects a hardware I2C controller.
2634 There are several other quantities that must also be
2635 defined when you define CONFIG_HARD_I2C.
2637 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2638 to be the frequency (in Hz) at which you wish your i2c bus
2639 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2640 the CPU's i2c node address).
2642 Now, the u-boot i2c code for the mpc8xx
2643 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2644 and so its address should therefore be cleared to 0 (See,
2645 eg, MPC823e User's Manual p.16-473). So, set
2646 CONFIG_SYS_I2C_SLAVE to 0.
2648 CONFIG_SYS_I2C_INIT_MPC5XXX
2650 When a board is reset during an i2c bus transfer
2651 chips might think that the current transfer is still
2652 in progress. Reset the slave devices by sending start
2653 commands until the slave device responds.
2655 That's all that's required for CONFIG_HARD_I2C.
2657 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2658 then the following macros need to be defined (examples are
2659 from include/configs/lwmon.h):
2663 (Optional). Any commands necessary to enable the I2C
2664 controller or configure ports.
2666 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2670 (Only for MPC8260 CPU). The I/O port to use (the code
2671 assumes both bits are on the same port). Valid values
2672 are 0..3 for ports A..D.
2676 The code necessary to make the I2C data line active
2677 (driven). If the data line is open collector, this
2680 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2684 The code necessary to make the I2C data line tri-stated
2685 (inactive). If the data line is open collector, this
2688 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2692 Code that returns true if the I2C data line is high,
2695 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2699 If <bit> is true, sets the I2C data line high. If it
2700 is false, it clears it (low).
2702 eg: #define I2C_SDA(bit) \
2703 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2704 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2708 If <bit> is true, sets the I2C clock line high. If it
2709 is false, it clears it (low).
2711 eg: #define I2C_SCL(bit) \
2712 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2713 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2717 This delay is invoked four times per clock cycle so this
2718 controls the rate of data transfer. The data rate thus
2719 is 1 / (I2C_DELAY * 4). Often defined to be something
2722 #define I2C_DELAY udelay(2)
2724 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2726 If your arch supports the generic GPIO framework (asm/gpio.h),
2727 then you may alternatively define the two GPIOs that are to be
2728 used as SCL / SDA. Any of the previous I2C_xxx macros will
2729 have GPIO-based defaults assigned to them as appropriate.
2731 You should define these to the GPIO value as given directly to
2732 the generic GPIO functions.
2734 CONFIG_SYS_I2C_INIT_BOARD
2736 When a board is reset during an i2c bus transfer
2737 chips might think that the current transfer is still
2738 in progress. On some boards it is possible to access
2739 the i2c SCLK line directly, either by using the
2740 processor pin as a GPIO or by having a second pin
2741 connected to the bus. If this option is defined a
2742 custom i2c_init_board() routine in boards/xxx/board.c
2743 is run early in the boot sequence.
2745 CONFIG_SYS_I2C_BOARD_LATE_INIT
2747 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2748 defined a custom i2c_board_late_init() routine in
2749 boards/xxx/board.c is run AFTER the operations in i2c_init()
2750 is completed. This callpoint can be used to unreset i2c bus
2751 using CPU i2c controller register accesses for CPUs whose i2c
2752 controller provide such a method. It is called at the end of
2753 i2c_init() to allow i2c_init operations to setup the i2c bus
2754 controller on the CPU (e.g. setting bus speed & slave address).
2756 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2758 This option enables configuration of bi_iic_fast[] flags
2759 in u-boot bd_info structure based on u-boot environment
2760 variable "i2cfast". (see also i2cfast)
2762 CONFIG_I2C_MULTI_BUS
2764 This option allows the use of multiple I2C buses, each of which
2765 must have a controller. At any point in time, only one bus is
2766 active. To switch to a different bus, use the 'i2c dev' command.
2767 Note that bus numbering is zero-based.
2769 CONFIG_SYS_I2C_NOPROBES
2771 This option specifies a list of I2C devices that will be skipped
2772 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2773 is set, specify a list of bus-device pairs. Otherwise, specify
2774 a 1D array of device addresses
2777 #undef CONFIG_I2C_MULTI_BUS
2778 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2780 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2782 #define CONFIG_I2C_MULTI_BUS
2783 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2785 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2787 CONFIG_SYS_SPD_BUS_NUM
2789 If defined, then this indicates the I2C bus number for DDR SPD.
2790 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2792 CONFIG_SYS_RTC_BUS_NUM
2794 If defined, then this indicates the I2C bus number for the RTC.
2795 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2797 CONFIG_SYS_DTT_BUS_NUM
2799 If defined, then this indicates the I2C bus number for the DTT.
2800 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2802 CONFIG_SYS_I2C_DTT_ADDR:
2804 If defined, specifies the I2C address of the DTT device.
2805 If not defined, then U-Boot uses predefined value for
2806 specified DTT device.
2808 CONFIG_SOFT_I2C_READ_REPEATED_START
2810 defining this will force the i2c_read() function in
2811 the soft_i2c driver to perform an I2C repeated start
2812 between writing the address pointer and reading the
2813 data. If this define is omitted the default behaviour
2814 of doing a stop-start sequence will be used. Most I2C
2815 devices can use either method, but some require one or
2818 - SPI Support: CONFIG_SPI
2820 Enables SPI driver (so far only tested with
2821 SPI EEPROM, also an instance works with Crystal A/D and
2822 D/As on the SACSng board)
2826 Enables the driver for SPI controller on SuperH. Currently
2827 only SH7757 is supported.
2831 Enables extended (16-bit) SPI EEPROM addressing.
2832 (symmetrical to CONFIG_I2C_X)
2836 Enables a software (bit-bang) SPI driver rather than
2837 using hardware support. This is a general purpose
2838 driver that only requires three general I/O port pins
2839 (two outputs, one input) to function. If this is
2840 defined, the board configuration must define several
2841 SPI configuration items (port pins to use, etc). For
2842 an example, see include/configs/sacsng.h.
2846 Enables a hardware SPI driver for general-purpose reads
2847 and writes. As with CONFIG_SOFT_SPI, the board configuration
2848 must define a list of chip-select function pointers.
2849 Currently supported on some MPC8xxx processors. For an
2850 example, see include/configs/mpc8349emds.h.
2854 Enables the driver for the SPI controllers on i.MX and MXC
2855 SoCs. Currently i.MX31/35/51 are supported.
2857 CONFIG_SYS_SPI_MXC_WAIT
2858 Timeout for waiting until spi transfer completed.
2859 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2861 - FPGA Support: CONFIG_FPGA
2863 Enables FPGA subsystem.
2865 CONFIG_FPGA_<vendor>
2867 Enables support for specific chip vendors.
2870 CONFIG_FPGA_<family>
2872 Enables support for FPGA family.
2873 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2877 Specify the number of FPGA devices to support.
2879 CONFIG_CMD_FPGA_LOADMK
2881 Enable support for fpga loadmk command
2883 CONFIG_CMD_FPGA_LOADP
2885 Enable support for fpga loadp command - load partial bitstream
2887 CONFIG_CMD_FPGA_LOADBP
2889 Enable support for fpga loadbp command - load partial bitstream
2892 CONFIG_SYS_FPGA_PROG_FEEDBACK
2894 Enable printing of hash marks during FPGA configuration.
2896 CONFIG_SYS_FPGA_CHECK_BUSY
2898 Enable checks on FPGA configuration interface busy
2899 status by the configuration function. This option
2900 will require a board or device specific function to
2905 If defined, a function that provides delays in the FPGA
2906 configuration driver.
2908 CONFIG_SYS_FPGA_CHECK_CTRLC
2909 Allow Control-C to interrupt FPGA configuration
2911 CONFIG_SYS_FPGA_CHECK_ERROR
2913 Check for configuration errors during FPGA bitfile
2914 loading. For example, abort during Virtex II
2915 configuration if the INIT_B line goes low (which
2916 indicated a CRC error).
2918 CONFIG_SYS_FPGA_WAIT_INIT
2920 Maximum time to wait for the INIT_B line to de-assert
2921 after PROB_B has been de-asserted during a Virtex II
2922 FPGA configuration sequence. The default time is 500
2925 CONFIG_SYS_FPGA_WAIT_BUSY
2927 Maximum time to wait for BUSY to de-assert during
2928 Virtex II FPGA configuration. The default is 5 ms.
2930 CONFIG_SYS_FPGA_WAIT_CONFIG
2932 Time to wait after FPGA configuration. The default is
2935 - Configuration Management:
2938 Some SoCs need special image types (e.g. U-Boot binary
2939 with a special header) as build targets. By defining
2940 CONFIG_BUILD_TARGET in the SoC / board header, this
2941 special image will be automatically built upon calling
2946 If defined, this string will be added to the U-Boot
2947 version information (U_BOOT_VERSION)
2949 - Vendor Parameter Protection:
2951 U-Boot considers the values of the environment
2952 variables "serial#" (Board Serial Number) and
2953 "ethaddr" (Ethernet Address) to be parameters that
2954 are set once by the board vendor / manufacturer, and
2955 protects these variables from casual modification by
2956 the user. Once set, these variables are read-only,
2957 and write or delete attempts are rejected. You can
2958 change this behaviour:
2960 If CONFIG_ENV_OVERWRITE is #defined in your config
2961 file, the write protection for vendor parameters is
2962 completely disabled. Anybody can change or delete
2965 Alternatively, if you #define _both_ CONFIG_ETHADDR
2966 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2967 Ethernet address is installed in the environment,
2968 which can be changed exactly ONCE by the user. [The
2969 serial# is unaffected by this, i. e. it remains
2972 The same can be accomplished in a more flexible way
2973 for any variable by configuring the type of access
2974 to allow for those variables in the ".flags" variable
2975 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2980 Define this variable to enable the reservation of
2981 "protected RAM", i. e. RAM which is not overwritten
2982 by U-Boot. Define CONFIG_PRAM to hold the number of
2983 kB you want to reserve for pRAM. You can overwrite
2984 this default value by defining an environment
2985 variable "pram" to the number of kB you want to
2986 reserve. Note that the board info structure will
2987 still show the full amount of RAM. If pRAM is
2988 reserved, a new environment variable "mem" will
2989 automatically be defined to hold the amount of
2990 remaining RAM in a form that can be passed as boot
2991 argument to Linux, for instance like that:
2993 setenv bootargs ... mem=\${mem}
2996 This way you can tell Linux not to use this memory,
2997 either, which results in a memory region that will
2998 not be affected by reboots.
3000 *WARNING* If your board configuration uses automatic
3001 detection of the RAM size, you must make sure that
3002 this memory test is non-destructive. So far, the
3003 following board configurations are known to be
3006 IVMS8, IVML24, SPD8xx, TQM8xxL,
3007 HERMES, IP860, RPXlite, LWMON,
3010 - Access to physical memory region (> 4GB)
3011 Some basic support is provided for operations on memory not
3012 normally accessible to U-Boot - e.g. some architectures
3013 support access to more than 4GB of memory on 32-bit
3014 machines using physical address extension or similar.
3015 Define CONFIG_PHYSMEM to access this basic support, which
3016 currently only supports clearing the memory.
3021 Define this variable to stop the system in case of a
3022 fatal error, so that you have to reset it manually.
3023 This is probably NOT a good idea for an embedded
3024 system where you want the system to reboot
3025 automatically as fast as possible, but it may be
3026 useful during development since you can try to debug
3027 the conditions that lead to the situation.
3029 CONFIG_NET_RETRY_COUNT
3031 This variable defines the number of retries for
3032 network operations like ARP, RARP, TFTP, or BOOTP
3033 before giving up the operation. If not defined, a
3034 default value of 5 is used.
3038 Timeout waiting for an ARP reply in milliseconds.
3042 Timeout in milliseconds used in NFS protocol.
3043 If you encounter "ERROR: Cannot umount" in nfs command,
3044 try longer timeout such as
3045 #define CONFIG_NFS_TIMEOUT 10000UL
3047 - Command Interpreter:
3048 CONFIG_AUTO_COMPLETE
3050 Enable auto completion of commands using TAB.
3052 CONFIG_SYS_PROMPT_HUSH_PS2
3054 This defines the secondary prompt string, which is
3055 printed when the command interpreter needs more input
3056 to complete a command. Usually "> ".
3060 In the current implementation, the local variables
3061 space and global environment variables space are
3062 separated. Local variables are those you define by
3063 simply typing `name=value'. To access a local
3064 variable later on, you have write `$name' or
3065 `${name}'; to execute the contents of a variable
3066 directly type `$name' at the command prompt.
3068 Global environment variables are those you use
3069 setenv/printenv to work with. To run a command stored
3070 in such a variable, you need to use the run command,
3071 and you must not use the '$' sign to access them.
3073 To store commands and special characters in a
3074 variable, please use double quotation marks
3075 surrounding the whole text of the variable, instead
3076 of the backslashes before semicolons and special
3079 - Command Line Editing and History:
3080 CONFIG_CMDLINE_EDITING
3082 Enable editing and History functions for interactive
3083 command line input operations
3085 - Default Environment:
3086 CONFIG_EXTRA_ENV_SETTINGS
3088 Define this to contain any number of null terminated
3089 strings (variable = value pairs) that will be part of
3090 the default environment compiled into the boot image.
3092 For example, place something like this in your
3093 board's config file:
3095 #define CONFIG_EXTRA_ENV_SETTINGS \
3099 Warning: This method is based on knowledge about the
3100 internal format how the environment is stored by the
3101 U-Boot code. This is NOT an official, exported
3102 interface! Although it is unlikely that this format
3103 will change soon, there is no guarantee either.
3104 You better know what you are doing here.
3106 Note: overly (ab)use of the default environment is
3107 discouraged. Make sure to check other ways to preset
3108 the environment like the "source" command or the
3111 CONFIG_ENV_VARS_UBOOT_CONFIG
3113 Define this in order to add variables describing the
3114 U-Boot build configuration to the default environment.
3115 These will be named arch, cpu, board, vendor, and soc.
3117 Enabling this option will cause the following to be defined:
3125 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3127 Define this in order to add variables describing certain
3128 run-time determined information about the hardware to the
3129 environment. These will be named board_name, board_rev.
3131 CONFIG_DELAY_ENVIRONMENT
3133 Normally the environment is loaded when the board is
3134 initialised so that it is available to U-Boot. This inhibits
3135 that so that the environment is not available until
3136 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3137 this is instead controlled by the value of
3138 /config/load-environment.
3140 - DataFlash Support:
3141 CONFIG_HAS_DATAFLASH
3143 Defining this option enables DataFlash features and
3144 allows to read/write in Dataflash via the standard
3147 - Serial Flash support
3150 Defining this option enables SPI flash commands
3151 'sf probe/read/write/erase/update'.
3153 Usage requires an initial 'probe' to define the serial
3154 flash parameters, followed by read/write/erase/update
3157 The following defaults may be provided by the platform
3158 to handle the common case when only a single serial
3159 flash is present on the system.
3161 CONFIG_SF_DEFAULT_BUS Bus identifier
3162 CONFIG_SF_DEFAULT_CS Chip-select
3163 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3164 CONFIG_SF_DEFAULT_SPEED in Hz
3168 Define this option to include a destructive SPI flash
3171 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3173 Define this option to use the Bank addr/Extended addr
3174 support on SPI flashes which has size > 16Mbytes.
3176 CONFIG_SF_DUAL_FLASH Dual flash memories
3178 Define this option to use dual flash support where two flash
3179 memories can be connected with a given cs line.
3180 Currently Xilinx Zynq qspi supports these type of connections.
3182 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3183 enable the W#/Vpp signal to disable writing to the status
3184 register on ST MICRON flashes like the N25Q128.
3185 The status register write enable/disable bit, combined with
3186 the W#/VPP signal provides hardware data protection for the
3187 device as follows: When the enable/disable bit is set to 1,
3188 and the W#/VPP signal is driven LOW, the status register
3189 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3190 operation will not execute. The only way to exit this
3191 hardware-protected mode is to drive W#/VPP HIGH.
3193 - SystemACE Support:
3196 Adding this option adds support for Xilinx SystemACE
3197 chips attached via some sort of local bus. The address
3198 of the chip must also be defined in the
3199 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3201 #define CONFIG_SYSTEMACE
3202 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3204 When SystemACE support is added, the "ace" device type
3205 becomes available to the fat commands, i.e. fatls.
3207 - TFTP Fixed UDP Port:
3210 If this is defined, the environment variable tftpsrcp
3211 is used to supply the TFTP UDP source port value.
3212 If tftpsrcp isn't defined, the normal pseudo-random port
3213 number generator is used.
3215 Also, the environment variable tftpdstp is used to supply
3216 the TFTP UDP destination port value. If tftpdstp isn't
3217 defined, the normal port 69 is used.
3219 The purpose for tftpsrcp is to allow a TFTP server to
3220 blindly start the TFTP transfer using the pre-configured
3221 target IP address and UDP port. This has the effect of
3222 "punching through" the (Windows XP) firewall, allowing
3223 the remainder of the TFTP transfer to proceed normally.
3224 A better solution is to properly configure the firewall,
3225 but sometimes that is not allowed.
3230 This enables a generic 'hash' command which can produce
3231 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3235 Enable the hash verify command (hash -v). This adds to code
3238 CONFIG_SHA1 - This option enables support of hashing using SHA1
3239 algorithm. The hash is calculated in software.
3240 CONFIG_SHA256 - This option enables support of hashing using
3241 SHA256 algorithm. The hash is calculated in software.
3242 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3243 for SHA1/SHA256 hashing.
3244 This affects the 'hash' command and also the
3245 hash_lookup_algo() function.
3246 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3247 hardware-acceleration for SHA1/SHA256 progressive hashing.
3248 Data can be streamed in a block at a time and the hashing
3249 is performed in hardware.
3251 Note: There is also a sha1sum command, which should perhaps
3252 be deprecated in favour of 'hash sha1'.
3254 - Freescale i.MX specific commands:
3255 CONFIG_CMD_HDMIDETECT
3256 This enables 'hdmidet' command which returns true if an
3257 HDMI monitor is detected. This command is i.MX 6 specific.
3260 This enables the 'bmode' (bootmode) command for forcing
3261 a boot from specific media.
3263 This is useful for forcing the ROM's usb downloader to
3264 activate upon a watchdog reset which is nice when iterating
3265 on U-Boot. Using the reset button or running bmode normal
3266 will set it back to normal. This command currently
3267 supports i.MX53 and i.MX6.
3272 This enables the RSA algorithm used for FIT image verification
3273 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3275 The Modular Exponentiation algorithm in RSA is implemented using
3276 driver model. So CONFIG_DM needs to be enabled by default for this
3277 library to function.
3279 The signing part is build into mkimage regardless of this
3280 option. The software based modular exponentiation is built into
3281 mkimage irrespective of this option.
3283 - bootcount support:
3284 CONFIG_BOOTCOUNT_LIMIT
3286 This enables the bootcounter support, see:
3287 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3290 enable special bootcounter support on at91sam9xe based boards.
3292 enable special bootcounter support on blackfin based boards.
3294 enable special bootcounter support on da850 based boards.
3295 CONFIG_BOOTCOUNT_RAM
3296 enable support for the bootcounter in RAM
3297 CONFIG_BOOTCOUNT_I2C
3298 enable support for the bootcounter on an i2c (like RTC) device.
3299 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3300 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3302 CONFIG_BOOTCOUNT_ALEN = address len
3304 - Show boot progress:
3305 CONFIG_SHOW_BOOT_PROGRESS
3307 Defining this option allows to add some board-
3308 specific code (calling a user-provided function
3309 "show_boot_progress(int)") that enables you to show
3310 the system's boot progress on some display (for
3311 example, some LED's) on your board. At the moment,
3312 the following checkpoints are implemented:
3314 - Detailed boot stage timing
3316 Define this option to get detailed timing of each stage
3317 of the boot process.
3319 CONFIG_BOOTSTAGE_USER_COUNT
3320 This is the number of available user bootstage records.
3321 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3322 a new ID will be allocated from this stash. If you exceed
3323 the limit, recording will stop.
3325 CONFIG_BOOTSTAGE_REPORT
3326 Define this to print a report before boot, similar to this:
3328 Timer summary in microseconds:
3331 3,575,678 3,575,678 board_init_f start
3332 3,575,695 17 arch_cpu_init A9
3333 3,575,777 82 arch_cpu_init done
3334 3,659,598 83,821 board_init_r start
3335 3,910,375 250,777 main_loop
3336 29,916,167 26,005,792 bootm_start
3337 30,361,327 445,160 start_kernel
3339 CONFIG_CMD_BOOTSTAGE
3340 Add a 'bootstage' command which supports printing a report
3341 and un/stashing of bootstage data.
3343 CONFIG_BOOTSTAGE_FDT
3344 Stash the bootstage information in the FDT. A root 'bootstage'
3345 node is created with each bootstage id as a child. Each child
3346 has a 'name' property and either 'mark' containing the
3347 mark time in microsecond, or 'accum' containing the
3348 accumulated time for that bootstage id in microseconds.
3353 name = "board_init_f";
3362 Code in the Linux kernel can find this in /proc/devicetree.
3364 Legacy uImage format:
3367 1 common/cmd_bootm.c before attempting to boot an image
3368 -1 common/cmd_bootm.c Image header has bad magic number
3369 2 common/cmd_bootm.c Image header has correct magic number
3370 -2 common/cmd_bootm.c Image header has bad checksum
3371 3 common/cmd_bootm.c Image header has correct checksum
3372 -3 common/cmd_bootm.c Image data has bad checksum
3373 4 common/cmd_bootm.c Image data has correct checksum
3374 -4 common/cmd_bootm.c Image is for unsupported architecture
3375 5 common/cmd_bootm.c Architecture check OK
3376 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3377 6 common/cmd_bootm.c Image Type check OK
3378 -6 common/cmd_bootm.c gunzip uncompression error
3379 -7 common/cmd_bootm.c Unimplemented compression type
3380 7 common/cmd_bootm.c Uncompression OK
3381 8 common/cmd_bootm.c No uncompress/copy overwrite error
3382 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3384 9 common/image.c Start initial ramdisk verification
3385 -10 common/image.c Ramdisk header has bad magic number
3386 -11 common/image.c Ramdisk header has bad checksum
3387 10 common/image.c Ramdisk header is OK
3388 -12 common/image.c Ramdisk data has bad checksum
3389 11 common/image.c Ramdisk data has correct checksum
3390 12 common/image.c Ramdisk verification complete, start loading
3391 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3392 13 common/image.c Start multifile image verification
3393 14 common/image.c No initial ramdisk, no multifile, continue.
3395 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3397 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3398 -31 post/post.c POST test failed, detected by post_output_backlog()
3399 -32 post/post.c POST test failed, detected by post_run_single()
3401 34 common/cmd_doc.c before loading a Image from a DOC device
3402 -35 common/cmd_doc.c Bad usage of "doc" command
3403 35 common/cmd_doc.c correct usage of "doc" command
3404 -36 common/cmd_doc.c No boot device
3405 36 common/cmd_doc.c correct boot device
3406 -37 common/cmd_doc.c Unknown Chip ID on boot device
3407 37 common/cmd_doc.c correct chip ID found, device available
3408 -38 common/cmd_doc.c Read Error on boot device
3409 38 common/cmd_doc.c reading Image header from DOC device OK
3410 -39 common/cmd_doc.c Image header has bad magic number
3411 39 common/cmd_doc.c Image header has correct magic number
3412 -40 common/cmd_doc.c Error reading Image from DOC device
3413 40 common/cmd_doc.c Image header has correct magic number
3414 41 common/cmd_ide.c before loading a Image from a IDE device
3415 -42 common/cmd_ide.c Bad usage of "ide" command
3416 42 common/cmd_ide.c correct usage of "ide" command
3417 -43 common/cmd_ide.c No boot device
3418 43 common/cmd_ide.c boot device found
3419 -44 common/cmd_ide.c Device not available
3420 44 common/cmd_ide.c Device available
3421 -45 common/cmd_ide.c wrong partition selected
3422 45 common/cmd_ide.c partition selected
3423 -46 common/cmd_ide.c Unknown partition table
3424 46 common/cmd_ide.c valid partition table found
3425 -47 common/cmd_ide.c Invalid partition type
3426 47 common/cmd_ide.c correct partition type
3427 -48 common/cmd_ide.c Error reading Image Header on boot device
3428 48 common/cmd_ide.c reading Image Header from IDE device OK
3429 -49 common/cmd_ide.c Image header has bad magic number
3430 49 common/cmd_ide.c Image header has correct magic number
3431 -50 common/cmd_ide.c Image header has bad checksum
3432 50 common/cmd_ide.c Image header has correct checksum
3433 -51 common/cmd_ide.c Error reading Image from IDE device
3434 51 common/cmd_ide.c reading Image from IDE device OK
3435 52 common/cmd_nand.c before loading a Image from a NAND device
3436 -53 common/cmd_nand.c Bad usage of "nand" command
3437 53 common/cmd_nand.c correct usage of "nand" command
3438 -54 common/cmd_nand.c No boot device
3439 54 common/cmd_nand.c boot device found
3440 -55 common/cmd_nand.c Unknown Chip ID on boot device
3441 55 common/cmd_nand.c correct chip ID found, device available
3442 -56 common/cmd_nand.c Error reading Image Header on boot device
3443 56 common/cmd_nand.c reading Image Header from NAND device OK
3444 -57 common/cmd_nand.c Image header has bad magic number
3445 57 common/cmd_nand.c Image header has correct magic number
3446 -58 common/cmd_nand.c Error reading Image from NAND device
3447 58 common/cmd_nand.c reading Image from NAND device OK
3449 -60 common/env_common.c Environment has a bad CRC, using default
3451 64 net/eth.c starting with Ethernet configuration.
3452 -64 net/eth.c no Ethernet found.
3453 65 net/eth.c Ethernet found.
3455 -80 common/cmd_net.c usage wrong
3456 80 common/cmd_net.c before calling NetLoop()
3457 -81 common/cmd_net.c some error in NetLoop() occurred
3458 81 common/cmd_net.c NetLoop() back without error
3459 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3460 82 common/cmd_net.c trying automatic boot
3461 83 common/cmd_net.c running "source" command
3462 -83 common/cmd_net.c some error in automatic boot or "source" command
3463 84 common/cmd_net.c end without errors
3468 100 common/cmd_bootm.c Kernel FIT Image has correct format
3469 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3470 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3471 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3472 102 common/cmd_bootm.c Kernel unit name specified
3473 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3474 103 common/cmd_bootm.c Found configuration node
3475 104 common/cmd_bootm.c Got kernel subimage node offset
3476 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3477 105 common/cmd_bootm.c Kernel subimage hash verification OK
3478 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3479 106 common/cmd_bootm.c Architecture check OK
3480 -106 common/cmd_bootm.c Kernel subimage has wrong type
3481 107 common/cmd_bootm.c Kernel subimage type OK
3482 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3483 108 common/cmd_bootm.c Got kernel subimage data/size
3484 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3485 -109 common/cmd_bootm.c Can't get kernel subimage type
3486 -110 common/cmd_bootm.c Can't get kernel subimage comp
3487 -111 common/cmd_bootm.c Can't get kernel subimage os
3488 -112 common/cmd_bootm.c Can't get kernel subimage load address
3489 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3491 120 common/image.c Start initial ramdisk verification
3492 -120 common/image.c Ramdisk FIT image has incorrect format
3493 121 common/image.c Ramdisk FIT image has correct format
3494 122 common/image.c No ramdisk subimage unit name, using configuration
3495 -122 common/image.c Can't get configuration for ramdisk subimage
3496 123 common/image.c Ramdisk unit name specified
3497 -124 common/image.c Can't get ramdisk subimage node offset
3498 125 common/image.c Got ramdisk subimage node offset
3499 -125 common/image.c Ramdisk subimage hash verification failed
3500 126 common/image.c Ramdisk subimage hash verification OK
3501 -126 common/image.c Ramdisk subimage for unsupported architecture
3502 127 common/image.c Architecture check OK
3503 -127 common/image.c Can't get ramdisk subimage data/size
3504 128 common/image.c Got ramdisk subimage data/size
3505 129 common/image.c Can't get ramdisk load address
3506 -129 common/image.c Got ramdisk load address
3508 -130 common/cmd_doc.c Incorrect FIT image format
3509 131 common/cmd_doc.c FIT image format OK
3511 -140 common/cmd_ide.c Incorrect FIT image format
3512 141 common/cmd_ide.c FIT image format OK
3514 -150 common/cmd_nand.c Incorrect FIT image format
3515 151 common/cmd_nand.c FIT image format OK
3517 - legacy image format:
3518 CONFIG_IMAGE_FORMAT_LEGACY
3519 enables the legacy image format support in U-Boot.
3522 enabled if CONFIG_FIT_SIGNATURE is not defined.
3524 CONFIG_DISABLE_IMAGE_LEGACY
3525 disable the legacy image format
3527 This define is introduced, as the legacy image format is
3528 enabled per default for backward compatibility.
3530 - FIT image support:
3532 Enable support for the FIT uImage format.
3534 CONFIG_FIT_BEST_MATCH
3535 When no configuration is explicitly selected, default to the
3536 one whose fdt's compatibility field best matches that of
3537 U-Boot itself. A match is considered "best" if it matches the
3538 most specific compatibility entry of U-Boot's fdt's root node.
3539 The order of entries in the configuration's fdt is ignored.
3541 CONFIG_FIT_SIGNATURE
3542 This option enables signature verification of FIT uImages,
3543 using a hash signed and verified using RSA. If
3544 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3545 hashing is available using hardware, RSA library will use it.
3546 See doc/uImage.FIT/signature.txt for more details.
3548 WARNING: When relying on signed FIT images with required
3549 signature check the legacy image format is default
3550 disabled. If a board need legacy image format support
3551 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3553 CONFIG_FIT_DISABLE_SHA256
3554 Supporting SHA256 hashes has quite an impact on binary size.
3555 For constrained systems sha256 hash support can be disabled
3558 - Standalone program support:
3559 CONFIG_STANDALONE_LOAD_ADDR
3561 This option defines a board specific value for the
3562 address where standalone program gets loaded, thus
3563 overwriting the architecture dependent default
3566 - Frame Buffer Address:
3569 Define CONFIG_FB_ADDR if you want to use specific
3570 address for frame buffer. This is typically the case
3571 when using a graphics controller has separate video
3572 memory. U-Boot will then place the frame buffer at
3573 the given address instead of dynamically reserving it
3574 in system RAM by calling lcd_setmem(), which grabs
3575 the memory for the frame buffer depending on the
3576 configured panel size.
3578 Please see board_init_f function.
3580 - Automatic software updates via TFTP server
3582 CONFIG_UPDATE_TFTP_CNT_MAX
3583 CONFIG_UPDATE_TFTP_MSEC_MAX
3585 These options enable and control the auto-update feature;
3586 for a more detailed description refer to doc/README.update.
3588 - MTD Support (mtdparts command, UBI support)
3591 Adds the MTD device infrastructure from the Linux kernel.
3592 Needed for mtdparts command support.
3594 CONFIG_MTD_PARTITIONS
3596 Adds the MTD partitioning infrastructure from the Linux
3597 kernel. Needed for UBI support.
3599 CONFIG_MTD_NAND_VERIFY_WRITE
3600 verify if the written data is correct reread.
3605 Adds commands for interacting with MTD partitions formatted
3606 with the UBI flash translation layer
3608 Requires also defining CONFIG_RBTREE
3610 CONFIG_UBI_SILENCE_MSG
3612 Make the verbose messages from UBI stop printing. This leaves
3613 warnings and errors enabled.
3616 CONFIG_MTD_UBI_WL_THRESHOLD
3617 This parameter defines the maximum difference between the highest
3618 erase counter value and the lowest erase counter value of eraseblocks
3619 of UBI devices. When this threshold is exceeded, UBI starts performing
3620 wear leveling by means of moving data from eraseblock with low erase
3621 counter to eraseblocks with high erase counter.
3623 The default value should be OK for SLC NAND flashes, NOR flashes and
3624 other flashes which have eraseblock life-cycle 100000 or more.
3625 However, in case of MLC NAND flashes which typically have eraseblock
3626 life-cycle less than 10000, the threshold should be lessened (e.g.,
3627 to 128 or 256, although it does not have to be power of 2).
3631 CONFIG_MTD_UBI_BEB_LIMIT
3632 This option specifies the maximum bad physical eraseblocks UBI
3633 expects on the MTD device (per 1024 eraseblocks). If the
3634 underlying flash does not admit of bad eraseblocks (e.g. NOR
3635 flash), this value is ignored.
3637 NAND datasheets often specify the minimum and maximum NVM
3638 (Number of Valid Blocks) for the flashes' endurance lifetime.
3639 The maximum expected bad eraseblocks per 1024 eraseblocks
3640 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3641 which gives 20 for most NANDs (MaxNVB is basically the total
3642 count of eraseblocks on the chip).
3644 To put it differently, if this value is 20, UBI will try to
3645 reserve about 1.9% of physical eraseblocks for bad blocks
3646 handling. And that will be 1.9% of eraseblocks on the entire
3647 NAND chip, not just the MTD partition UBI attaches. This means
3648 that if you have, say, a NAND flash chip admits maximum 40 bad
3649 eraseblocks, and it is split on two MTD partitions of the same
3650 size, UBI will reserve 40 eraseblocks when attaching a
3655 CONFIG_MTD_UBI_FASTMAP
3656 Fastmap is a mechanism which allows attaching an UBI device
3657 in nearly constant time. Instead of scanning the whole MTD device it
3658 only has to locate a checkpoint (called fastmap) on the device.
3659 The on-flash fastmap contains all information needed to attach
3660 the device. Using fastmap makes only sense on large devices where
3661 attaching by scanning takes long. UBI will not automatically install
3662 a fastmap on old images, but you can set the UBI parameter
3663 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3664 that fastmap-enabled images are still usable with UBI implementations
3665 without fastmap support. On typical flash devices the whole fastmap
3666 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3668 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3669 Set this parameter to enable fastmap automatically on images
3676 Adds commands for interacting with UBI volumes formatted as
3677 UBIFS. UBIFS is read-only in u-boot.
3679 Requires UBI support as well as CONFIG_LZO
3681 CONFIG_UBIFS_SILENCE_MSG
3683 Make the verbose messages from UBIFS stop printing. This leaves
3684 warnings and errors enabled.
3688 Enable building of SPL globally.
3691 LDSCRIPT for linking the SPL binary.
3693 CONFIG_SPL_MAX_FOOTPRINT
3694 Maximum size in memory allocated to the SPL, BSS included.
3695 When defined, the linker checks that the actual memory
3696 used by SPL from _start to __bss_end does not exceed it.
3697 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3698 must not be both defined at the same time.
3701 Maximum size of the SPL image (text, data, rodata, and
3702 linker lists sections), BSS excluded.
3703 When defined, the linker checks that the actual size does
3706 CONFIG_SPL_TEXT_BASE
3707 TEXT_BASE for linking the SPL binary.
3709 CONFIG_SPL_RELOC_TEXT_BASE
3710 Address to relocate to. If unspecified, this is equal to
3711 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3713 CONFIG_SPL_BSS_START_ADDR
3714 Link address for the BSS within the SPL binary.
3716 CONFIG_SPL_BSS_MAX_SIZE
3717 Maximum size in memory allocated to the SPL BSS.
3718 When defined, the linker checks that the actual memory used
3719 by SPL from __bss_start to __bss_end does not exceed it.
3720 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3721 must not be both defined at the same time.
3724 Adress of the start of the stack SPL will use
3726 CONFIG_SPL_RELOC_STACK
3727 Adress of the start of the stack SPL will use after
3728 relocation. If unspecified, this is equal to
3731 CONFIG_SYS_SPL_MALLOC_START
3732 Starting address of the malloc pool used in SPL.
3734 CONFIG_SYS_SPL_MALLOC_SIZE
3735 The size of the malloc pool used in SPL.
3737 CONFIG_SPL_FRAMEWORK
3738 Enable the SPL framework under common/. This framework
3739 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3740 NAND loading of the Linux Kernel.
3743 Enable booting directly to an OS from SPL.
3744 See also: doc/README.falcon
3746 CONFIG_SPL_DISPLAY_PRINT
3747 For ARM, enable an optional function to print more information
3748 about the running system.
3750 CONFIG_SPL_INIT_MINIMAL
3751 Arch init code should be built for a very small image
3753 CONFIG_SPL_LIBCOMMON_SUPPORT
3754 Support for common/libcommon.o in SPL binary
3756 CONFIG_SPL_LIBDISK_SUPPORT
3757 Support for disk/libdisk.o in SPL binary
3759 CONFIG_SPL_I2C_SUPPORT
3760 Support for drivers/i2c/libi2c.o in SPL binary
3762 CONFIG_SPL_GPIO_SUPPORT
3763 Support for drivers/gpio/libgpio.o in SPL binary
3765 CONFIG_SPL_MMC_SUPPORT
3766 Support for drivers/mmc/libmmc.o in SPL binary
3768 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3769 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3770 Address and partition on the MMC to load U-Boot from
3771 when the MMC is being used in raw mode.
3773 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3774 Partition on the MMC to load U-Boot from when the MMC is being
3777 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3778 Sector to load kernel uImage from when MMC is being
3779 used in raw mode (for Falcon mode)
3781 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3782 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3783 Sector and number of sectors to load kernel argument
3784 parameters from when MMC is being used in raw mode
3787 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3788 Partition on the MMC to load U-Boot from when the MMC is being
3791 CONFIG_SPL_FAT_SUPPORT
3792 Support for fs/fat/libfat.o in SPL binary
3794 CONFIG_SPL_EXT_SUPPORT
3795 Support for EXT filesystem in SPL binary
3797 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3798 Filename to read to load U-Boot when reading from filesystem
3800 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3801 Filename to read to load kernel uImage when reading
3802 from filesystem (for Falcon mode)
3804 CONFIG_SPL_FS_LOAD_ARGS_NAME
3805 Filename to read to load kernel argument parameters
3806 when reading from filesystem (for Falcon mode)
3808 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3809 Set this for NAND SPL on PPC mpc83xx targets, so that
3810 start.S waits for the rest of the SPL to load before
3811 continuing (the hardware starts execution after just
3812 loading the first page rather than the full 4K).
3814 CONFIG_SPL_SKIP_RELOCATE
3815 Avoid SPL relocation
3817 CONFIG_SPL_NAND_BASE
3818 Include nand_base.c in the SPL. Requires
3819 CONFIG_SPL_NAND_DRIVERS.
3821 CONFIG_SPL_NAND_DRIVERS
3822 SPL uses normal NAND drivers, not minimal drivers.
3825 Include standard software ECC in the SPL
3827 CONFIG_SPL_NAND_SIMPLE
3828 Support for NAND boot using simple NAND drivers that
3829 expose the cmd_ctrl() interface.
3831 CONFIG_SPL_MTD_SUPPORT
3832 Support for the MTD subsystem within SPL. Useful for
3833 environment on NAND support within SPL.
3835 CONFIG_SPL_NAND_RAW_ONLY
3836 Support to boot only raw u-boot.bin images. Use this only
3837 if you need to save space.
3839 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3840 Set for the SPL on PPC mpc8xxx targets, support for
3841 drivers/ddr/fsl/libddr.o in SPL binary.
3843 CONFIG_SPL_COMMON_INIT_DDR
3844 Set for common ddr init with serial presence detect in
3847 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3848 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3849 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3850 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3851 CONFIG_SYS_NAND_ECCBYTES
3852 Defines the size and behavior of the NAND that SPL uses
3855 CONFIG_SPL_NAND_BOOT
3856 Add support NAND boot
3858 CONFIG_SYS_NAND_U_BOOT_OFFS
3859 Location in NAND to read U-Boot from
3861 CONFIG_SYS_NAND_U_BOOT_DST
3862 Location in memory to load U-Boot to
3864 CONFIG_SYS_NAND_U_BOOT_SIZE
3865 Size of image to load
3867 CONFIG_SYS_NAND_U_BOOT_START
3868 Entry point in loaded image to jump to
3870 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3871 Define this if you need to first read the OOB and then the
3872 data. This is used, for example, on davinci platforms.
3874 CONFIG_SPL_OMAP3_ID_NAND
3875 Support for an OMAP3-specific set of functions to return the
3876 ID and MFR of the first attached NAND chip, if present.
3878 CONFIG_SPL_SERIAL_SUPPORT
3879 Support for drivers/serial/libserial.o in SPL binary
3881 CONFIG_SPL_SPI_FLASH_SUPPORT
3882 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3884 CONFIG_SPL_SPI_SUPPORT
3885 Support for drivers/spi/libspi.o in SPL binary
3887 CONFIG_SPL_RAM_DEVICE
3888 Support for running image already present in ram, in SPL binary
3890 CONFIG_SPL_LIBGENERIC_SUPPORT
3891 Support for lib/libgeneric.o in SPL binary
3893 CONFIG_SPL_ENV_SUPPORT
3894 Support for the environment operating in SPL binary
3896 CONFIG_SPL_NET_SUPPORT
3897 Support for the net/libnet.o in SPL binary.
3898 It conflicts with SPL env from storage medium specified by
3899 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3902 Image offset to which the SPL should be padded before appending
3903 the SPL payload. By default, this is defined as
3904 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3905 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3906 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3909 Final target image containing SPL and payload. Some SPLs
3910 use an arch-specific makefile fragment instead, for
3911 example if more than one image needs to be produced.
3913 CONFIG_FIT_SPL_PRINT
3914 Printing information about a FIT image adds quite a bit of
3915 code to SPL. So this is normally disabled in SPL. Use this
3916 option to re-enable it. This will affect the output of the
3917 bootm command when booting a FIT image.
3921 Enable building of TPL globally.
3924 Image offset to which the TPL should be padded before appending
3925 the TPL payload. By default, this is defined as
3926 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3927 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3928 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3933 [so far only for SMDK2400 boards]
3935 - Modem support enable:
3936 CONFIG_MODEM_SUPPORT
3938 - RTS/CTS Flow control enable:
3941 - Modem debug support:
3942 CONFIG_MODEM_SUPPORT_DEBUG
3944 Enables debugging stuff (char screen[1024], dbg())
3945 for modem support. Useful only with BDI2000.
3947 - Interrupt support (PPC):
3949 There are common interrupt_init() and timer_interrupt()
3950 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3951 for CPU specific initialization. interrupt_init_cpu()
3952 should set decrementer_count to appropriate value. If
3953 CPU resets decrementer automatically after interrupt
3954 (ppc4xx) it should set decrementer_count to zero.
3955 timer_interrupt() calls timer_interrupt_cpu() for CPU
3956 specific handling. If board has watchdog / status_led
3957 / other_activity_monitor it works automatically from
3958 general timer_interrupt().
3962 In the target system modem support is enabled when a
3963 specific key (key combination) is pressed during
3964 power-on. Otherwise U-Boot will boot normally
3965 (autoboot). The key_pressed() function is called from
3966 board_init(). Currently key_pressed() is a dummy
3967 function, returning 1 and thus enabling modem
3970 If there are no modem init strings in the
3971 environment, U-Boot proceed to autoboot; the
3972 previous output (banner, info printfs) will be
3975 See also: doc/README.Modem
3977 Board initialization settings:
3978 ------------------------------
3980 During Initialization u-boot calls a number of board specific functions
3981 to allow the preparation of board specific prerequisites, e.g. pin setup
3982 before drivers are initialized. To enable these callbacks the
3983 following configuration macros have to be defined. Currently this is
3984 architecture specific, so please check arch/your_architecture/lib/board.c
3985 typically in board_init_f() and board_init_r().
3987 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3988 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3989 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3990 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3992 Configuration Settings:
3993 -----------------------
3995 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3996 Optionally it can be defined to support 64-bit memory commands.
3998 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3999 undefine this when you're short of memory.
4001 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
4002 width of the commands listed in the 'help' command output.
4004 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
4005 prompt for user input.
4007 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
4009 - CONFIG_SYS_PBSIZE: Buffer size for Console output
4011 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
4013 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
4014 the application (usually a Linux kernel) when it is
4017 - CONFIG_SYS_BAUDRATE_TABLE:
4018 List of legal baudrate settings for this board.
4020 - CONFIG_SYS_CONSOLE_INFO_QUIET
4021 Suppress display of console information at boot.
4023 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4024 If the board specific function
4025 extern int overwrite_console (void);
4026 returns 1, the stdin, stderr and stdout are switched to the
4027 serial port, else the settings in the environment are used.
4029 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4030 Enable the call to overwrite_console().
4032 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4033 Enable overwrite of previous console environment settings.
4035 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4036 Begin and End addresses of the area used by the
4039 - CONFIG_SYS_ALT_MEMTEST:
4040 Enable an alternate, more extensive memory test.
4042 - CONFIG_SYS_MEMTEST_SCRATCH:
4043 Scratch address used by the alternate memory test
4044 You only need to set this if address zero isn't writeable
4046 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4047 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4048 this specified memory area will get subtracted from the top
4049 (end) of RAM and won't get "touched" at all by U-Boot. By
4050 fixing up gd->ram_size the Linux kernel should gets passed
4051 the now "corrected" memory size and won't touch it either.
4052 This should work for arch/ppc and arch/powerpc. Only Linux
4053 board ports in arch/powerpc with bootwrapper support that
4054 recalculate the memory size from the SDRAM controller setup
4055 will have to get fixed in Linux additionally.
4057 This option can be used as a workaround for the 440EPx/GRx
4058 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4061 WARNING: Please make sure that this value is a multiple of
4062 the Linux page size (normally 4k). If this is not the case,
4063 then the end address of the Linux memory will be located at a
4064 non page size aligned address and this could cause major
4067 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4068 Enable temporary baudrate change while serial download
4070 - CONFIG_SYS_SDRAM_BASE:
4071 Physical start address of SDRAM. _Must_ be 0 here.
4073 - CONFIG_SYS_MBIO_BASE:
4074 Physical start address of Motherboard I/O (if using a
4077 - CONFIG_SYS_FLASH_BASE:
4078 Physical start address of Flash memory.
4080 - CONFIG_SYS_MONITOR_BASE:
4081 Physical start address of boot monitor code (set by
4082 make config files to be same as the text base address
4083 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4084 CONFIG_SYS_FLASH_BASE when booting from flash.
4086 - CONFIG_SYS_MONITOR_LEN:
4087 Size of memory reserved for monitor code, used to
4088 determine _at_compile_time_ (!) if the environment is
4089 embedded within the U-Boot image, or in a separate
4092 - CONFIG_SYS_MALLOC_LEN:
4093 Size of DRAM reserved for malloc() use.
4095 - CONFIG_SYS_MALLOC_F_LEN
4096 Size of the malloc() pool for use before relocation. If
4097 this is defined, then a very simple malloc() implementation
4098 will become available before relocation. The address is just
4099 below the global data, and the stack is moved down to make
4102 This feature allocates regions with increasing addresses
4103 within the region. calloc() is supported, but realloc()
4104 is not available. free() is supported but does nothing.
4105 The memory will be freed (or in fact just forgotten) when
4106 U-Boot relocates itself.
4108 Pre-relocation malloc() is only supported on ARM and sandbox
4109 at present but is fairly easy to enable for other archs.
4111 - CONFIG_SYS_MALLOC_SIMPLE
4112 Provides a simple and small malloc() and calloc() for those
4113 boards which do not use the full malloc in SPL (which is
4114 enabled with CONFIG_SYS_SPL_MALLOC_START).
4116 - CONFIG_SYS_NONCACHED_MEMORY:
4117 Size of non-cached memory area. This area of memory will be
4118 typically located right below the malloc() area and mapped
4119 uncached in the MMU. This is useful for drivers that would
4120 otherwise require a lot of explicit cache maintenance. For
4121 some drivers it's also impossible to properly maintain the
4122 cache. For example if the regions that need to be flushed
4123 are not a multiple of the cache-line size, *and* padding
4124 cannot be allocated between the regions to align them (i.e.
4125 if the HW requires a contiguous array of regions, and the
4126 size of each region is not cache-aligned), then a flush of
4127 one region may result in overwriting data that hardware has
4128 written to another region in the same cache-line. This can
4129 happen for example in network drivers where descriptors for
4130 buffers are typically smaller than the CPU cache-line (e.g.
4131 16 bytes vs. 32 or 64 bytes).
4133 Non-cached memory is only supported on 32-bit ARM at present.
4135 - CONFIG_SYS_BOOTM_LEN:
4136 Normally compressed uImages are limited to an
4137 uncompressed size of 8 MBytes. If this is not enough,
4138 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4139 to adjust this setting to your needs.
4141 - CONFIG_SYS_BOOTMAPSZ:
4142 Maximum size of memory mapped by the startup code of
4143 the Linux kernel; all data that must be processed by
4144 the Linux kernel (bd_info, boot arguments, FDT blob if
4145 used) must be put below this limit, unless "bootm_low"
4146 environment variable is defined and non-zero. In such case
4147 all data for the Linux kernel must be between "bootm_low"
4148 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4149 variable "bootm_mapsize" will override the value of
4150 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4151 then the value in "bootm_size" will be used instead.
4153 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4154 Enable initrd_high functionality. If defined then the
4155 initrd_high feature is enabled and the bootm ramdisk subcommand
4158 - CONFIG_SYS_BOOT_GET_CMDLINE:
4159 Enables allocating and saving kernel cmdline in space between
4160 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4162 - CONFIG_SYS_BOOT_GET_KBD:
4163 Enables allocating and saving a kernel copy of the bd_info in
4164 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4166 - CONFIG_SYS_MAX_FLASH_BANKS:
4167 Max number of Flash memory banks
4169 - CONFIG_SYS_MAX_FLASH_SECT:
4170 Max number of sectors on a Flash chip
4172 - CONFIG_SYS_FLASH_ERASE_TOUT:
4173 Timeout for Flash erase operations (in ms)
4175 - CONFIG_SYS_FLASH_WRITE_TOUT:
4176 Timeout for Flash write operations (in ms)
4178 - CONFIG_SYS_FLASH_LOCK_TOUT
4179 Timeout for Flash set sector lock bit operation (in ms)
4181 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4182 Timeout for Flash clear lock bits operation (in ms)
4184 - CONFIG_SYS_FLASH_PROTECTION
4185 If defined, hardware flash sectors protection is used
4186 instead of U-Boot software protection.
4188 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4190 Enable TFTP transfers directly to flash memory;
4191 without this option such a download has to be
4192 performed in two steps: (1) download to RAM, and (2)
4193 copy from RAM to flash.
4195 The two-step approach is usually more reliable, since
4196 you can check if the download worked before you erase
4197 the flash, but in some situations (when system RAM is
4198 too limited to allow for a temporary copy of the
4199 downloaded image) this option may be very useful.
4201 - CONFIG_SYS_FLASH_CFI:
4202 Define if the flash driver uses extra elements in the
4203 common flash structure for storing flash geometry.
4205 - CONFIG_FLASH_CFI_DRIVER
4206 This option also enables the building of the cfi_flash driver
4207 in the drivers directory
4209 - CONFIG_FLASH_CFI_MTD
4210 This option enables the building of the cfi_mtd driver
4211 in the drivers directory. The driver exports CFI flash
4214 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4215 Use buffered writes to flash.
4217 - CONFIG_FLASH_SPANSION_S29WS_N
4218 s29ws-n MirrorBit flash has non-standard addresses for buffered
4221 - CONFIG_SYS_FLASH_QUIET_TEST
4222 If this option is defined, the common CFI flash doesn't
4223 print it's warning upon not recognized FLASH banks. This
4224 is useful, if some of the configured banks are only
4225 optionally available.
4227 - CONFIG_FLASH_SHOW_PROGRESS
4228 If defined (must be an integer), print out countdown
4229 digits and dots. Recommended value: 45 (9..1) for 80
4230 column displays, 15 (3..1) for 40 column displays.
4232 - CONFIG_FLASH_VERIFY
4233 If defined, the content of the flash (destination) is compared
4234 against the source after the write operation. An error message
4235 will be printed when the contents are not identical.
4236 Please note that this option is useless in nearly all cases,
4237 since such flash programming errors usually are detected earlier
4238 while unprotecting/erasing/programming. Please only enable
4239 this option if you really know what you are doing.
4241 - CONFIG_SYS_RX_ETH_BUFFER:
4242 Defines the number of Ethernet receive buffers. On some
4243 Ethernet controllers it is recommended to set this value
4244 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4245 buffers can be full shortly after enabling the interface
4246 on high Ethernet traffic.
4247 Defaults to 4 if not defined.
4249 - CONFIG_ENV_MAX_ENTRIES
4251 Maximum number of entries in the hash table that is used
4252 internally to store the environment settings. The default
4253 setting is supposed to be generous and should work in most
4254 cases. This setting can be used to tune behaviour; see
4255 lib/hashtable.c for details.
4257 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4258 - CONFIG_ENV_FLAGS_LIST_STATIC
4259 Enable validation of the values given to environment variables when
4260 calling env set. Variables can be restricted to only decimal,
4261 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4262 the variables can also be restricted to IP address or MAC address.
4264 The format of the list is:
4265 type_attribute = [s|d|x|b|i|m]
4266 access_attribute = [a|r|o|c]
4267 attributes = type_attribute[access_attribute]
4268 entry = variable_name[:attributes]
4271 The type attributes are:
4272 s - String (default)
4275 b - Boolean ([1yYtT|0nNfF])
4279 The access attributes are:
4285 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4286 Define this to a list (string) to define the ".flags"
4287 environment variable in the default or embedded environment.
4289 - CONFIG_ENV_FLAGS_LIST_STATIC
4290 Define this to a list (string) to define validation that
4291 should be done if an entry is not found in the ".flags"
4292 environment variable. To override a setting in the static
4293 list, simply add an entry for the same variable name to the
4296 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4297 If defined, don't allow the -f switch to env set override variable
4300 - CONFIG_SYS_GENERIC_BOARD
4301 This selects the architecture-generic board system instead of the
4302 architecture-specific board files. It is intended to move boards
4303 to this new framework over time. Defining this will disable the
4304 arch/foo/lib/board.c file and use common/board_f.c and
4305 common/board_r.c instead. To use this option your architecture
4306 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4307 its config.mk file). If you find problems enabling this option on
4308 your board please report the problem and send patches!
4310 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4311 This is set by OMAP boards for the max time that reset should
4312 be asserted. See doc/README.omap-reset-time for details on how
4313 the value can be calculated on a given board.
4316 If stdint.h is available with your toolchain you can define this
4317 option to enable it. You can provide option 'USE_STDINT=1' when
4318 building U-Boot to enable this.
4320 The following definitions that deal with the placement and management
4321 of environment data (variable area); in general, we support the
4322 following configurations:
4324 - CONFIG_BUILD_ENVCRC:
4326 Builds up envcrc with the target environment so that external utils
4327 may easily extract it and embed it in final U-Boot images.
4329 - CONFIG_ENV_IS_IN_FLASH:
4331 Define this if the environment is in flash memory.
4333 a) The environment occupies one whole flash sector, which is
4334 "embedded" in the text segment with the U-Boot code. This
4335 happens usually with "bottom boot sector" or "top boot
4336 sector" type flash chips, which have several smaller
4337 sectors at the start or the end. For instance, such a
4338 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4339 such a case you would place the environment in one of the
4340 4 kB sectors - with U-Boot code before and after it. With
4341 "top boot sector" type flash chips, you would put the
4342 environment in one of the last sectors, leaving a gap
4343 between U-Boot and the environment.
4345 - CONFIG_ENV_OFFSET:
4347 Offset of environment data (variable area) to the
4348 beginning of flash memory; for instance, with bottom boot
4349 type flash chips the second sector can be used: the offset
4350 for this sector is given here.
4352 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4356 This is just another way to specify the start address of
4357 the flash sector containing the environment (instead of
4360 - CONFIG_ENV_SECT_SIZE:
4362 Size of the sector containing the environment.
4365 b) Sometimes flash chips have few, equal sized, BIG sectors.
4366 In such a case you don't want to spend a whole sector for
4371 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4372 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4373 of this flash sector for the environment. This saves
4374 memory for the RAM copy of the environment.
4376 It may also save flash memory if you decide to use this
4377 when your environment is "embedded" within U-Boot code,
4378 since then the remainder of the flash sector could be used
4379 for U-Boot code. It should be pointed out that this is
4380 STRONGLY DISCOURAGED from a robustness point of view:
4381 updating the environment in flash makes it always
4382 necessary to erase the WHOLE sector. If something goes
4383 wrong before the contents has been restored from a copy in
4384 RAM, your target system will be dead.
4386 - CONFIG_ENV_ADDR_REDUND
4387 CONFIG_ENV_SIZE_REDUND
4389 These settings describe a second storage area used to hold
4390 a redundant copy of the environment data, so that there is
4391 a valid backup copy in case there is a power failure during
4392 a "saveenv" operation.
4394 BE CAREFUL! Any changes to the flash layout, and some changes to the
4395 source code will make it necessary to adapt <board>/u-boot.lds*
4399 - CONFIG_ENV_IS_IN_NVRAM:
4401 Define this if you have some non-volatile memory device
4402 (NVRAM, battery buffered SRAM) which you want to use for the
4408 These two #defines are used to determine the memory area you
4409 want to use for environment. It is assumed that this memory
4410 can just be read and written to, without any special
4413 BE CAREFUL! The first access to the environment happens quite early
4414 in U-Boot initialization (when we try to get the setting of for the
4415 console baudrate). You *MUST* have mapped your NVRAM area then, or
4418 Please note that even with NVRAM we still use a copy of the
4419 environment in RAM: we could work on NVRAM directly, but we want to
4420 keep settings there always unmodified except somebody uses "saveenv"
4421 to save the current settings.
4424 - CONFIG_ENV_IS_IN_EEPROM:
4426 Use this if you have an EEPROM or similar serial access
4427 device and a driver for it.
4429 - CONFIG_ENV_OFFSET:
4432 These two #defines specify the offset and size of the
4433 environment area within the total memory of your EEPROM.
4435 - CONFIG_SYS_I2C_EEPROM_ADDR:
4436 If defined, specified the chip address of the EEPROM device.
4437 The default address is zero.
4439 - CONFIG_SYS_I2C_EEPROM_BUS:
4440 If defined, specified the i2c bus of the EEPROM device.
4442 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4443 If defined, the number of bits used to address bytes in a
4444 single page in the EEPROM device. A 64 byte page, for example
4445 would require six bits.
4447 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4448 If defined, the number of milliseconds to delay between
4449 page writes. The default is zero milliseconds.
4451 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4452 The length in bytes of the EEPROM memory array address. Note
4453 that this is NOT the chip address length!
4455 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4456 EEPROM chips that implement "address overflow" are ones
4457 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4458 address and the extra bits end up in the "chip address" bit
4459 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4462 Note that we consider the length of the address field to
4463 still be one byte because the extra address bits are hidden
4464 in the chip address.
4466 - CONFIG_SYS_EEPROM_SIZE:
4467 The size in bytes of the EEPROM device.
4469 - CONFIG_ENV_EEPROM_IS_ON_I2C
4470 define this, if you have I2C and SPI activated, and your
4471 EEPROM, which holds the environment, is on the I2C bus.
4473 - CONFIG_I2C_ENV_EEPROM_BUS
4474 if you have an Environment on an EEPROM reached over
4475 I2C muxes, you can define here, how to reach this
4476 EEPROM. For example:
4478 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4480 EEPROM which holds the environment, is reached over
4481 a pca9547 i2c mux with address 0x70, channel 3.
4483 - CONFIG_ENV_IS_IN_DATAFLASH:
4485 Define this if you have a DataFlash memory device which you
4486 want to use for the environment.
4488 - CONFIG_ENV_OFFSET:
4492 These three #defines specify the offset and size of the
4493 environment area within the total memory of your DataFlash placed
4494 at the specified address.
4496 - CONFIG_ENV_IS_IN_SPI_FLASH:
4498 Define this if you have a SPI Flash memory device which you
4499 want to use for the environment.
4501 - CONFIG_ENV_OFFSET:
4504 These two #defines specify the offset and size of the
4505 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4506 aligned to an erase sector boundary.
4508 - CONFIG_ENV_SECT_SIZE:
4510 Define the SPI flash's sector size.
4512 - CONFIG_ENV_OFFSET_REDUND (optional):
4514 This setting describes a second storage area of CONFIG_ENV_SIZE
4515 size used to hold a redundant copy of the environment data, so
4516 that there is a valid backup copy in case there is a power failure
4517 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4518 aligned to an erase sector boundary.
4520 - CONFIG_ENV_SPI_BUS (optional):
4521 - CONFIG_ENV_SPI_CS (optional):
4523 Define the SPI bus and chip select. If not defined they will be 0.
4525 - CONFIG_ENV_SPI_MAX_HZ (optional):
4527 Define the SPI max work clock. If not defined then use 1MHz.
4529 - CONFIG_ENV_SPI_MODE (optional):
4531 Define the SPI work mode. If not defined then use SPI_MODE_3.
4533 - CONFIG_ENV_IS_IN_REMOTE:
4535 Define this if you have a remote memory space which you
4536 want to use for the local device's environment.
4541 These two #defines specify the address and size of the
4542 environment area within the remote memory space. The
4543 local device can get the environment from remote memory
4544 space by SRIO or PCIE links.
4546 BE CAREFUL! For some special cases, the local device can not use
4547 "saveenv" command. For example, the local device will get the
4548 environment stored in a remote NOR flash by SRIO or PCIE link,
4549 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4551 - CONFIG_ENV_IS_IN_NAND:
4553 Define this if you have a NAND device which you want to use
4554 for the environment.
4556 - CONFIG_ENV_OFFSET:
4559 These two #defines specify the offset and size of the environment
4560 area within the first NAND device. CONFIG_ENV_OFFSET must be
4561 aligned to an erase block boundary.
4563 - CONFIG_ENV_OFFSET_REDUND (optional):
4565 This setting describes a second storage area of CONFIG_ENV_SIZE
4566 size used to hold a redundant copy of the environment data, so
4567 that there is a valid backup copy in case there is a power failure
4568 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4569 aligned to an erase block boundary.
4571 - CONFIG_ENV_RANGE (optional):
4573 Specifies the length of the region in which the environment
4574 can be written. This should be a multiple of the NAND device's
4575 block size. Specifying a range with more erase blocks than
4576 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4577 the range to be avoided.
4579 - CONFIG_ENV_OFFSET_OOB (optional):
4581 Enables support for dynamically retrieving the offset of the
4582 environment from block zero's out-of-band data. The
4583 "nand env.oob" command can be used to record this offset.
4584 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4585 using CONFIG_ENV_OFFSET_OOB.
4587 - CONFIG_NAND_ENV_DST
4589 Defines address in RAM to which the nand_spl code should copy the
4590 environment. If redundant environment is used, it will be copied to
4591 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4593 - CONFIG_ENV_IS_IN_UBI:
4595 Define this if you have an UBI volume that you want to use for the
4596 environment. This has the benefit of wear-leveling the environment
4597 accesses, which is important on NAND.
4599 - CONFIG_ENV_UBI_PART:
4601 Define this to a string that is the mtd partition containing the UBI.
4603 - CONFIG_ENV_UBI_VOLUME:
4605 Define this to the name of the volume that you want to store the
4608 - CONFIG_ENV_UBI_VOLUME_REDUND:
4610 Define this to the name of another volume to store a second copy of
4611 the environment in. This will enable redundant environments in UBI.
4612 It is assumed that both volumes are in the same MTD partition.
4614 - CONFIG_UBI_SILENCE_MSG
4615 - CONFIG_UBIFS_SILENCE_MSG
4617 You will probably want to define these to avoid a really noisy system
4618 when storing the env in UBI.
4620 - CONFIG_ENV_IS_IN_FAT:
4621 Define this if you want to use the FAT file system for the environment.
4623 - FAT_ENV_INTERFACE:
4625 Define this to a string that is the name of the block device.
4627 - FAT_ENV_DEV_AND_PART:
4629 Define this to a string to specify the partition of the device. It can
4632 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4633 - "D:P": device D partition P. Error occurs if device D has no
4636 - "D" or "D:": device D partition 1 if device D has partition
4637 table, or the whole device D if has no partition
4639 - "D:auto": first partition in device D with bootable flag set.
4640 If none, first valid partition in device D. If no
4641 partition table then means device D.
4645 It's a string of the FAT file name. This file use to store the
4649 This should be defined. Otherwise it cannot save the environment file.
4651 - CONFIG_ENV_IS_IN_MMC:
4653 Define this if you have an MMC device which you want to use for the
4656 - CONFIG_SYS_MMC_ENV_DEV:
4658 Specifies which MMC device the environment is stored in.
4660 - CONFIG_SYS_MMC_ENV_PART (optional):
4662 Specifies which MMC partition the environment is stored in. If not
4663 set, defaults to partition 0, the user area. Common values might be
4664 1 (first MMC boot partition), 2 (second MMC boot partition).
4666 - CONFIG_ENV_OFFSET:
4669 These two #defines specify the offset and size of the environment
4670 area within the specified MMC device.
4672 If offset is positive (the usual case), it is treated as relative to
4673 the start of the MMC partition. If offset is negative, it is treated
4674 as relative to the end of the MMC partition. This can be useful if
4675 your board may be fitted with different MMC devices, which have
4676 different sizes for the MMC partitions, and you always want the
4677 environment placed at the very end of the partition, to leave the
4678 maximum possible space before it, to store other data.
4680 These two values are in units of bytes, but must be aligned to an
4681 MMC sector boundary.
4683 - CONFIG_ENV_OFFSET_REDUND (optional):
4685 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4686 hold a redundant copy of the environment data. This provides a
4687 valid backup copy in case the other copy is corrupted, e.g. due
4688 to a power failure during a "saveenv" operation.
4690 This value may also be positive or negative; this is handled in the
4691 same way as CONFIG_ENV_OFFSET.
4693 This value is also in units of bytes, but must also be aligned to
4694 an MMC sector boundary.
4696 - CONFIG_ENV_SIZE_REDUND (optional):
4698 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4699 set. If this value is set, it must be set to the same value as
4702 - CONFIG_SYS_SPI_INIT_OFFSET
4704 Defines offset to the initial SPI buffer area in DPRAM. The
4705 area is used at an early stage (ROM part) if the environment
4706 is configured to reside in the SPI EEPROM: We need a 520 byte
4707 scratch DPRAM area. It is used between the two initialization
4708 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4709 to be a good choice since it makes it far enough from the
4710 start of the data area as well as from the stack pointer.
4712 Please note that the environment is read-only until the monitor
4713 has been relocated to RAM and a RAM copy of the environment has been
4714 created; also, when using EEPROM you will have to use getenv_f()
4715 until then to read environment variables.
4717 The environment is protected by a CRC32 checksum. Before the monitor
4718 is relocated into RAM, as a result of a bad CRC you will be working
4719 with the compiled-in default environment - *silently*!!! [This is
4720 necessary, because the first environment variable we need is the
4721 "baudrate" setting for the console - if we have a bad CRC, we don't
4722 have any device yet where we could complain.]
4724 Note: once the monitor has been relocated, then it will complain if
4725 the default environment is used; a new CRC is computed as soon as you
4726 use the "saveenv" command to store a valid environment.
4728 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4729 Echo the inverted Ethernet link state to the fault LED.
4731 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4732 also needs to be defined.
4734 - CONFIG_SYS_FAULT_MII_ADDR:
4735 MII address of the PHY to check for the Ethernet link state.
4737 - CONFIG_NS16550_MIN_FUNCTIONS:
4738 Define this if you desire to only have use of the NS16550_init
4739 and NS16550_putc functions for the serial driver located at
4740 drivers/serial/ns16550.c. This option is useful for saving
4741 space for already greatly restricted images, including but not
4742 limited to NAND_SPL configurations.
4744 - CONFIG_DISPLAY_BOARDINFO
4745 Display information about the board that U-Boot is running on
4746 when U-Boot starts up. The board function checkboard() is called
4749 - CONFIG_DISPLAY_BOARDINFO_LATE
4750 Similar to the previous option, but display this information
4751 later, once stdio is running and output goes to the LCD, if
4754 - CONFIG_BOARD_SIZE_LIMIT:
4755 Maximum size of the U-Boot image. When defined, the
4756 build system checks that the actual size does not
4759 Low Level (hardware related) configuration options:
4760 ---------------------------------------------------
4762 - CONFIG_SYS_CACHELINE_SIZE:
4763 Cache Line Size of the CPU.
4765 - CONFIG_SYS_DEFAULT_IMMR:
4766 Default address of the IMMR after system reset.
4768 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4769 and RPXsuper) to be able to adjust the position of
4770 the IMMR register after a reset.
4772 - CONFIG_SYS_CCSRBAR_DEFAULT:
4773 Default (power-on reset) physical address of CCSR on Freescale
4776 - CONFIG_SYS_CCSRBAR:
4777 Virtual address of CCSR. On a 32-bit build, this is typically
4778 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4780 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4781 for cross-platform code that uses that macro instead.
4783 - CONFIG_SYS_CCSRBAR_PHYS:
4784 Physical address of CCSR. CCSR can be relocated to a new
4785 physical address, if desired. In this case, this macro should
4786 be set to that address. Otherwise, it should be set to the
4787 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4788 is typically relocated on 36-bit builds. It is recommended
4789 that this macro be defined via the _HIGH and _LOW macros:
4791 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4792 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4794 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4795 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4796 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4797 used in assembly code, so it must not contain typecasts or
4798 integer size suffixes (e.g. "ULL").
4800 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4801 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4802 used in assembly code, so it must not contain typecasts or
4803 integer size suffixes (e.g. "ULL").
4805 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4806 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4807 forced to a value that ensures that CCSR is not relocated.
4809 - Floppy Disk Support:
4810 CONFIG_SYS_FDC_DRIVE_NUMBER
4812 the default drive number (default value 0)
4814 CONFIG_SYS_ISA_IO_STRIDE
4816 defines the spacing between FDC chipset registers
4819 CONFIG_SYS_ISA_IO_OFFSET
4821 defines the offset of register from address. It
4822 depends on which part of the data bus is connected to
4823 the FDC chipset. (default value 0)
4825 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4826 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4829 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4830 fdc_hw_init() is called at the beginning of the FDC
4831 setup. fdc_hw_init() must be provided by the board
4832 source code. It is used to make hardware-dependent
4836 Most IDE controllers were designed to be connected with PCI
4837 interface. Only few of them were designed for AHB interface.
4838 When software is doing ATA command and data transfer to
4839 IDE devices through IDE-AHB controller, some additional
4840 registers accessing to these kind of IDE-AHB controller
4843 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4844 DO NOT CHANGE unless you know exactly what you're
4845 doing! (11-4) [MPC8xx/82xx systems only]
4847 - CONFIG_SYS_INIT_RAM_ADDR:
4849 Start address of memory area that can be used for
4850 initial data and stack; please note that this must be
4851 writable memory that is working WITHOUT special
4852 initialization, i. e. you CANNOT use normal RAM which
4853 will become available only after programming the
4854 memory controller and running certain initialization
4857 U-Boot uses the following memory types:
4858 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4859 - MPC824X: data cache
4860 - PPC4xx: data cache
4862 - CONFIG_SYS_GBL_DATA_OFFSET:
4864 Offset of the initial data structure in the memory
4865 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4866 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4867 data is located at the end of the available space
4868 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4869 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4870 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4871 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4874 On the MPC824X (or other systems that use the data
4875 cache for initial memory) the address chosen for
4876 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4877 point to an otherwise UNUSED address space between
4878 the top of RAM and the start of the PCI space.
4880 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4882 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4884 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4886 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4888 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4890 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4892 - CONFIG_SYS_OR_TIMING_SDRAM:
4895 - CONFIG_SYS_MAMR_PTA:
4896 periodic timer for refresh
4898 - CONFIG_SYS_DER: Debug Event Register (37-47)
4900 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4901 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4902 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4903 CONFIG_SYS_BR1_PRELIM:
4904 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4906 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4907 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4908 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4909 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4911 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4912 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4913 Machine Mode Register and Memory Periodic Timer
4914 Prescaler definitions (SDRAM timing)
4916 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4917 enable I2C microcode relocation patch (MPC8xx);
4918 define relocation offset in DPRAM [DSP2]
4920 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4921 enable SMC microcode relocation patch (MPC8xx);
4922 define relocation offset in DPRAM [SMC1]
4924 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4925 enable SPI microcode relocation patch (MPC8xx);
4926 define relocation offset in DPRAM [SCC4]
4928 - CONFIG_SYS_USE_OSCCLK:
4929 Use OSCM clock mode on MBX8xx board. Be careful,
4930 wrong setting might damage your board. Read
4931 doc/README.MBX before setting this variable!
4933 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4934 Offset of the bootmode word in DPRAM used by post
4935 (Power On Self Tests). This definition overrides
4936 #define'd default value in commproc.h resp.
4939 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4940 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4941 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4942 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4943 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4944 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4945 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4946 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4947 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4949 - CONFIG_PCI_DISABLE_PCIE:
4950 Disable PCI-Express on systems where it is supported but not
4953 - CONFIG_PCI_ENUM_ONLY
4954 Only scan through and get the devices on the buses.
4955 Don't do any setup work, presumably because someone or
4956 something has already done it, and we don't need to do it
4957 a second time. Useful for platforms that are pre-booted
4958 by coreboot or similar.
4960 - CONFIG_PCI_INDIRECT_BRIDGE:
4961 Enable support for indirect PCI bridges.
4964 Chip has SRIO or not
4967 Board has SRIO 1 port available
4970 Board has SRIO 2 port available
4972 - CONFIG_SRIO_PCIE_BOOT_MASTER
4973 Board can support master function for Boot from SRIO and PCIE
4975 - CONFIG_SYS_SRIOn_MEM_VIRT:
4976 Virtual Address of SRIO port 'n' memory region
4978 - CONFIG_SYS_SRIOn_MEM_PHYS:
4979 Physical Address of SRIO port 'n' memory region
4981 - CONFIG_SYS_SRIOn_MEM_SIZE:
4982 Size of SRIO port 'n' memory region
4984 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4985 Defined to tell the NAND controller that the NAND chip is using
4987 Not all NAND drivers use this symbol.
4988 Example of drivers that use it:
4989 - drivers/mtd/nand/ndfc.c
4990 - drivers/mtd/nand/mxc_nand.c
4992 - CONFIG_SYS_NDFC_EBC0_CFG
4993 Sets the EBC0_CFG register for the NDFC. If not defined
4994 a default value will be used.
4997 Get DDR timing information from an I2C EEPROM. Common
4998 with pluggable memory modules such as SODIMMs
5001 I2C address of the SPD EEPROM
5003 - CONFIG_SYS_SPD_BUS_NUM
5004 If SPD EEPROM is on an I2C bus other than the first
5005 one, specify here. Note that the value must resolve
5006 to something your driver can deal with.
5008 - CONFIG_SYS_DDR_RAW_TIMING
5009 Get DDR timing information from other than SPD. Common with
5010 soldered DDR chips onboard without SPD. DDR raw timing
5011 parameters are extracted from datasheet and hard-coded into
5012 header files or board specific files.
5014 - CONFIG_FSL_DDR_INTERACTIVE
5015 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5017 - CONFIG_FSL_DDR_SYNC_REFRESH
5018 Enable sync of refresh for multiple controllers.
5020 - CONFIG_SYS_83XX_DDR_USES_CS0
5021 Only for 83xx systems. If specified, then DDR should
5022 be configured using CS0 and CS1 instead of CS2 and CS3.
5024 - CONFIG_ETHER_ON_FEC[12]
5025 Define to enable FEC[12] on a 8xx series processor.
5027 - CONFIG_FEC[12]_PHY
5028 Define to the hardcoded PHY address which corresponds
5029 to the given FEC; i. e.
5030 #define CONFIG_FEC1_PHY 4
5031 means that the PHY with address 4 is connected to FEC1
5033 When set to -1, means to probe for first available.
5035 - CONFIG_FEC[12]_PHY_NORXERR
5036 The PHY does not have a RXERR line (RMII only).
5037 (so program the FEC to ignore it).
5040 Enable RMII mode for all FECs.
5041 Note that this is a global option, we can't
5042 have one FEC in standard MII mode and another in RMII mode.
5044 - CONFIG_CRC32_VERIFY
5045 Add a verify option to the crc32 command.
5048 => crc32 -v <address> <count> <crc32>
5050 Where address/count indicate a memory area
5051 and crc32 is the correct crc32 which the
5055 Add the "loopw" memory command. This only takes effect if
5056 the memory commands are activated globally (CONFIG_CMD_MEM).
5059 Add the "mdc" and "mwc" memory commands. These are cyclic
5064 This command will print 4 bytes (10,11,12,13) each 500 ms.
5066 => mwc.l 100 12345678 10
5067 This command will write 12345678 to address 100 all 10 ms.
5069 This only takes effect if the memory commands are activated
5070 globally (CONFIG_CMD_MEM).
5072 - CONFIG_SKIP_LOWLEVEL_INIT
5073 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5074 low level initializations (like setting up the memory
5075 controller) are omitted and/or U-Boot does not
5076 relocate itself into RAM.
5078 Normally this variable MUST NOT be defined. The only
5079 exception is when U-Boot is loaded (to RAM) by some
5080 other boot loader or by a debugger which performs
5081 these initializations itself.
5084 Modifies the behaviour of start.S when compiling a loader
5085 that is executed before the actual U-Boot. E.g. when
5086 compiling a NAND SPL.
5089 Modifies the behaviour of start.S when compiling a loader
5090 that is executed after the SPL and before the actual U-Boot.
5091 It is loaded by the SPL.
5093 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5094 Only for 85xx systems. If this variable is specified, the section
5095 .resetvec is not kept and the section .bootpg is placed in the
5096 previous 4k of the .text section.
5098 - CONFIG_ARCH_MAP_SYSMEM
5099 Generally U-Boot (and in particular the md command) uses
5100 effective address. It is therefore not necessary to regard
5101 U-Boot address as virtual addresses that need to be translated
5102 to physical addresses. However, sandbox requires this, since
5103 it maintains its own little RAM buffer which contains all
5104 addressable memory. This option causes some memory accesses
5105 to be mapped through map_sysmem() / unmap_sysmem().
5107 - CONFIG_USE_ARCH_MEMCPY
5108 CONFIG_USE_ARCH_MEMSET
5109 If these options are used a optimized version of memcpy/memset will
5110 be used if available. These functions may be faster under some
5111 conditions but may increase the binary size.
5113 - CONFIG_X86_RESET_VECTOR
5114 If defined, the x86 reset vector code is included. This is not
5115 needed when U-Boot is running from Coreboot.
5118 Defines the MPU clock speed (in MHz).
5120 NOTE : currently only supported on AM335x platforms.
5122 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5123 Enables the RTC32K OSC on AM33xx based plattforms
5125 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5126 Option to disable subpage write in NAND driver
5127 driver that uses this:
5128 drivers/mtd/nand/davinci_nand.c
5130 Freescale QE/FMAN Firmware Support:
5131 -----------------------------------
5133 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5134 loading of "firmware", which is encoded in the QE firmware binary format.
5135 This firmware often needs to be loaded during U-Boot booting, so macros
5136 are used to identify the storage device (NOR flash, SPI, etc) and the address
5139 - CONFIG_SYS_FMAN_FW_ADDR
5140 The address in the storage device where the FMAN microcode is located. The
5141 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5144 - CONFIG_SYS_QE_FW_ADDR
5145 The address in the storage device where the QE microcode is located. The
5146 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5149 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5150 The maximum possible size of the firmware. The firmware binary format
5151 has a field that specifies the actual size of the firmware, but it
5152 might not be possible to read any part of the firmware unless some
5153 local storage is allocated to hold the entire firmware first.
5155 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5156 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5157 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5158 virtual address in NOR flash.
5160 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5161 Specifies that QE/FMAN firmware is located in NAND flash.
5162 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5164 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5165 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5166 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5168 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5169 Specifies that QE/FMAN firmware is located on the primary SPI
5170 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5172 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5173 Specifies that QE/FMAN firmware is located in the remote (master)
5174 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5175 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5176 window->master inbound window->master LAW->the ucode address in
5177 master's memory space.
5179 Freescale Layerscape Management Complex Firmware Support:
5180 ---------------------------------------------------------
5181 The Freescale Layerscape Management Complex (MC) supports the loading of
5183 This firmware often needs to be loaded during U-Boot booting, so macros
5184 are used to identify the storage device (NOR flash, SPI, etc) and the address
5187 - CONFIG_FSL_MC_ENET
5188 Enable the MC driver for Layerscape SoCs.
5190 - CONFIG_SYS_LS_MC_FW_ADDR
5191 The address in the storage device where the firmware is located. The
5192 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5195 - CONFIG_SYS_LS_MC_FW_LENGTH
5196 The maximum possible size of the firmware. The firmware binary format
5197 has a field that specifies the actual size of the firmware, but it
5198 might not be possible to read any part of the firmware unless some
5199 local storage is allocated to hold the entire firmware first.
5201 - CONFIG_SYS_LS_MC_FW_IN_NOR
5202 Specifies that MC firmware is located in NOR flash, mapped as
5203 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5204 virtual address in NOR flash.
5206 Building the Software:
5207 ======================
5209 Building U-Boot has been tested in several native build environments
5210 and in many different cross environments. Of course we cannot support
5211 all possibly existing versions of cross development tools in all
5212 (potentially obsolete) versions. In case of tool chain problems we
5213 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5214 which is extensively used to build and test U-Boot.
5216 If you are not using a native environment, it is assumed that you
5217 have GNU cross compiling tools available in your path. In this case,
5218 you must set the environment variable CROSS_COMPILE in your shell.
5219 Note that no changes to the Makefile or any other source files are
5220 necessary. For example using the ELDK on a 4xx CPU, please enter:
5222 $ CROSS_COMPILE=ppc_4xx-
5223 $ export CROSS_COMPILE
5225 Note: If you wish to generate Windows versions of the utilities in
5226 the tools directory you can use the MinGW toolchain
5227 (http://www.mingw.org). Set your HOST tools to the MinGW
5228 toolchain and execute 'make tools'. For example:
5230 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5232 Binaries such as tools/mkimage.exe will be created which can
5233 be executed on computers running Windows.
5235 U-Boot is intended to be simple to build. After installing the
5236 sources you must configure U-Boot for one specific board type. This
5241 where "NAME_defconfig" is the name of one of the existing configu-
5242 rations; see boards.cfg for supported names.
5244 Note: for some board special configuration names may exist; check if
5245 additional information is available from the board vendor; for
5246 instance, the TQM823L systems are available without (standard)
5247 or with LCD support. You can select such additional "features"
5248 when choosing the configuration, i. e.
5250 make TQM823L_defconfig
5251 - will configure for a plain TQM823L, i. e. no LCD support
5253 make TQM823L_LCD_defconfig
5254 - will configure for a TQM823L with U-Boot console on LCD
5259 Finally, type "make all", and you should get some working U-Boot
5260 images ready for download to / installation on your system:
5262 - "u-boot.bin" is a raw binary image
5263 - "u-boot" is an image in ELF binary format
5264 - "u-boot.srec" is in Motorola S-Record format
5266 By default the build is performed locally and the objects are saved
5267 in the source directory. One of the two methods can be used to change
5268 this behavior and build U-Boot to some external directory:
5270 1. Add O= to the make command line invocations:
5272 make O=/tmp/build distclean
5273 make O=/tmp/build NAME_defconfig
5274 make O=/tmp/build all
5276 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5278 export KBUILD_OUTPUT=/tmp/build
5283 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5287 Please be aware that the Makefiles assume you are using GNU make, so
5288 for instance on NetBSD you might need to use "gmake" instead of
5292 If the system board that you have is not listed, then you will need
5293 to port U-Boot to your hardware platform. To do this, follow these
5296 1. Add a new configuration option for your board to the toplevel
5297 "boards.cfg" file, using the existing entries as examples.
5298 Follow the instructions there to keep the boards in order.
5299 2. Create a new directory to hold your board specific code. Add any
5300 files you need. In your board directory, you will need at least
5301 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5302 3. Create a new configuration file "include/configs/<board>.h" for
5304 3. If you're porting U-Boot to a new CPU, then also create a new
5305 directory to hold your CPU specific code. Add any files you need.
5306 4. Run "make <board>_defconfig" with your new name.
5307 5. Type "make", and you should get a working "u-boot.srec" file
5308 to be installed on your target system.
5309 6. Debug and solve any problems that might arise.
5310 [Of course, this last step is much harder than it sounds.]
5313 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5314 ==============================================================
5316 If you have modified U-Boot sources (for instance added a new board
5317 or support for new devices, a new CPU, etc.) you are expected to
5318 provide feedback to the other developers. The feedback normally takes
5319 the form of a "patch", i. e. a context diff against a certain (latest
5320 official or latest in the git repository) version of U-Boot sources.
5322 But before you submit such a patch, please verify that your modifi-
5323 cation did not break existing code. At least make sure that *ALL* of
5324 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5325 just run the "MAKEALL" script, which will configure and build U-Boot
5326 for ALL supported system. Be warned, this will take a while. You can
5327 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5328 environment variable to the script, i. e. to use the ELDK cross tools
5331 CROSS_COMPILE=ppc_8xx- MAKEALL
5333 or to build on a native PowerPC system you can type
5335 CROSS_COMPILE=' ' MAKEALL
5337 When using the MAKEALL script, the default behaviour is to build
5338 U-Boot in the source directory. This location can be changed by
5339 setting the BUILD_DIR environment variable. Also, for each target
5340 built, the MAKEALL script saves two log files (<target>.ERR and
5341 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5342 location can be changed by setting the MAKEALL_LOGDIR environment
5343 variable. For example:
5345 export BUILD_DIR=/tmp/build
5346 export MAKEALL_LOGDIR=/tmp/log
5347 CROSS_COMPILE=ppc_8xx- MAKEALL
5349 With the above settings build objects are saved in the /tmp/build,
5350 log files are saved in the /tmp/log and the source tree remains clean
5351 during the whole build process.
5354 See also "U-Boot Porting Guide" below.
5357 Monitor Commands - Overview:
5358 ============================
5360 go - start application at address 'addr'
5361 run - run commands in an environment variable
5362 bootm - boot application image from memory
5363 bootp - boot image via network using BootP/TFTP protocol
5364 bootz - boot zImage from memory
5365 tftpboot- boot image via network using TFTP protocol
5366 and env variables "ipaddr" and "serverip"
5367 (and eventually "gatewayip")
5368 tftpput - upload a file via network using TFTP protocol
5369 rarpboot- boot image via network using RARP/TFTP protocol
5370 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5371 loads - load S-Record file over serial line
5372 loadb - load binary file over serial line (kermit mode)
5374 mm - memory modify (auto-incrementing)
5375 nm - memory modify (constant address)
5376 mw - memory write (fill)
5378 cmp - memory compare
5379 crc32 - checksum calculation
5380 i2c - I2C sub-system
5381 sspi - SPI utility commands
5382 base - print or set address offset
5383 printenv- print environment variables
5384 setenv - set environment variables
5385 saveenv - save environment variables to persistent storage
5386 protect - enable or disable FLASH write protection
5387 erase - erase FLASH memory
5388 flinfo - print FLASH memory information
5389 nand - NAND memory operations (see doc/README.nand)
5390 bdinfo - print Board Info structure
5391 iminfo - print header information for application image
5392 coninfo - print console devices and informations
5393 ide - IDE sub-system
5394 loop - infinite loop on address range
5395 loopw - infinite write loop on address range
5396 mtest - simple RAM test
5397 icache - enable or disable instruction cache
5398 dcache - enable or disable data cache
5399 reset - Perform RESET of the CPU
5400 echo - echo args to console
5401 version - print monitor version
5402 help - print online help
5403 ? - alias for 'help'
5406 Monitor Commands - Detailed Description:
5407 ========================================
5411 For now: just type "help <command>".
5414 Environment Variables:
5415 ======================
5417 U-Boot supports user configuration using Environment Variables which
5418 can be made persistent by saving to Flash memory.
5420 Environment Variables are set using "setenv", printed using
5421 "printenv", and saved to Flash using "saveenv". Using "setenv"
5422 without a value can be used to delete a variable from the
5423 environment. As long as you don't save the environment you are
5424 working with an in-memory copy. In case the Flash area containing the
5425 environment is erased by accident, a default environment is provided.
5427 Some configuration options can be set using Environment Variables.
5429 List of environment variables (most likely not complete):
5431 baudrate - see CONFIG_BAUDRATE
5433 bootdelay - see CONFIG_BOOTDELAY
5435 bootcmd - see CONFIG_BOOTCOMMAND
5437 bootargs - Boot arguments when booting an RTOS image
5439 bootfile - Name of the image to load with TFTP
5441 bootm_low - Memory range available for image processing in the bootm
5442 command can be restricted. This variable is given as
5443 a hexadecimal number and defines lowest address allowed
5444 for use by the bootm command. See also "bootm_size"
5445 environment variable. Address defined by "bootm_low" is
5446 also the base of the initial memory mapping for the Linux
5447 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5450 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5451 This variable is given as a hexadecimal number and it
5452 defines the size of the memory region starting at base
5453 address bootm_low that is accessible by the Linux kernel
5454 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5455 as the default value if it is defined, and bootm_size is
5458 bootm_size - Memory range available for image processing in the bootm
5459 command can be restricted. This variable is given as
5460 a hexadecimal number and defines the size of the region
5461 allowed for use by the bootm command. See also "bootm_low"
5462 environment variable.
5464 updatefile - Location of the software update file on a TFTP server, used
5465 by the automatic software update feature. Please refer to
5466 documentation in doc/README.update for more details.
5468 autoload - if set to "no" (any string beginning with 'n'),
5469 "bootp" will just load perform a lookup of the
5470 configuration from the BOOTP server, but not try to
5471 load any image using TFTP
5473 autostart - if set to "yes", an image loaded using the "bootp",
5474 "rarpboot", "tftpboot" or "diskboot" commands will
5475 be automatically started (by internally calling
5478 If set to "no", a standalone image passed to the
5479 "bootm" command will be copied to the load address
5480 (and eventually uncompressed), but NOT be started.
5481 This can be used to load and uncompress arbitrary
5484 fdt_high - if set this restricts the maximum address that the
5485 flattened device tree will be copied into upon boot.
5486 For example, if you have a system with 1 GB memory
5487 at physical address 0x10000000, while Linux kernel
5488 only recognizes the first 704 MB as low memory, you
5489 may need to set fdt_high as 0x3C000000 to have the
5490 device tree blob be copied to the maximum address
5491 of the 704 MB low memory, so that Linux kernel can
5492 access it during the boot procedure.
5494 If this is set to the special value 0xFFFFFFFF then
5495 the fdt will not be copied at all on boot. For this
5496 to work it must reside in writable memory, have
5497 sufficient padding on the end of it for u-boot to
5498 add the information it needs into it, and the memory
5499 must be accessible by the kernel.
5501 fdtcontroladdr- if set this is the address of the control flattened
5502 device tree used by U-Boot when CONFIG_OF_CONTROL is
5505 i2cfast - (PPC405GP|PPC405EP only)
5506 if set to 'y' configures Linux I2C driver for fast
5507 mode (400kHZ). This environment variable is used in
5508 initialization code. So, for changes to be effective
5509 it must be saved and board must be reset.
5511 initrd_high - restrict positioning of initrd images:
5512 If this variable is not set, initrd images will be
5513 copied to the highest possible address in RAM; this
5514 is usually what you want since it allows for
5515 maximum initrd size. If for some reason you want to
5516 make sure that the initrd image is loaded below the
5517 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5518 variable to a value of "no" or "off" or "0".
5519 Alternatively, you can set it to a maximum upper
5520 address to use (U-Boot will still check that it
5521 does not overwrite the U-Boot stack and data).
5523 For instance, when you have a system with 16 MB
5524 RAM, and want to reserve 4 MB from use by Linux,
5525 you can do this by adding "mem=12M" to the value of
5526 the "bootargs" variable. However, now you must make
5527 sure that the initrd image is placed in the first
5528 12 MB as well - this can be done with
5530 setenv initrd_high 00c00000
5532 If you set initrd_high to 0xFFFFFFFF, this is an
5533 indication to U-Boot that all addresses are legal
5534 for the Linux kernel, including addresses in flash
5535 memory. In this case U-Boot will NOT COPY the
5536 ramdisk at all. This may be useful to reduce the
5537 boot time on your system, but requires that this
5538 feature is supported by your Linux kernel.
5540 ipaddr - IP address; needed for tftpboot command
5542 loadaddr - Default load address for commands like "bootp",
5543 "rarpboot", "tftpboot", "loadb" or "diskboot"
5545 loads_echo - see CONFIG_LOADS_ECHO
5547 serverip - TFTP server IP address; needed for tftpboot command
5549 bootretry - see CONFIG_BOOT_RETRY_TIME
5551 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5553 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5555 ethprime - controls which interface is used first.
5557 ethact - controls which interface is currently active.
5558 For example you can do the following
5560 => setenv ethact FEC
5561 => ping 192.168.0.1 # traffic sent on FEC
5562 => setenv ethact SCC
5563 => ping 10.0.0.1 # traffic sent on SCC
5565 ethrotate - When set to "no" U-Boot does not go through all
5566 available network interfaces.
5567 It just stays at the currently selected interface.
5569 netretry - When set to "no" each network operation will
5570 either succeed or fail without retrying.
5571 When set to "once" the network operation will
5572 fail when all the available network interfaces
5573 are tried once without success.
5574 Useful on scripts which control the retry operation
5577 npe_ucode - set load address for the NPE microcode
5579 silent_linux - If set then Linux will be told to boot silently, by
5580 changing the console to be empty. If "yes" it will be
5581 made silent. If "no" it will not be made silent. If
5582 unset, then it will be made silent if the U-Boot console
5585 tftpsrcport - If this is set, the value is used for TFTP's
5588 tftpdstport - If this is set, the value is used for TFTP's UDP
5589 destination port instead of the Well Know Port 69.
5591 tftpblocksize - Block size to use for TFTP transfers; if not set,
5592 we use the TFTP server's default block size
5594 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5595 seconds, minimum value is 1000 = 1 second). Defines
5596 when a packet is considered to be lost so it has to
5597 be retransmitted. The default is 5000 = 5 seconds.
5598 Lowering this value may make downloads succeed
5599 faster in networks with high packet loss rates or
5600 with unreliable TFTP servers.
5602 vlan - When set to a value < 4095 the traffic over
5603 Ethernet is encapsulated/received over 802.1q
5606 The following image location variables contain the location of images
5607 used in booting. The "Image" column gives the role of the image and is
5608 not an environment variable name. The other columns are environment
5609 variable names. "File Name" gives the name of the file on a TFTP
5610 server, "RAM Address" gives the location in RAM the image will be
5611 loaded to, and "Flash Location" gives the image's address in NOR
5612 flash or offset in NAND flash.
5614 *Note* - these variables don't have to be defined for all boards, some
5615 boards currenlty use other variables for these purposes, and some
5616 boards use these variables for other purposes.
5618 Image File Name RAM Address Flash Location
5619 ----- --------- ----------- --------------
5620 u-boot u-boot u-boot_addr_r u-boot_addr
5621 Linux kernel bootfile kernel_addr_r kernel_addr
5622 device tree blob fdtfile fdt_addr_r fdt_addr
5623 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5625 The following environment variables may be used and automatically
5626 updated by the network boot commands ("bootp" and "rarpboot"),
5627 depending the information provided by your boot server:
5629 bootfile - see above
5630 dnsip - IP address of your Domain Name Server
5631 dnsip2 - IP address of your secondary Domain Name Server
5632 gatewayip - IP address of the Gateway (Router) to use
5633 hostname - Target hostname
5635 netmask - Subnet Mask
5636 rootpath - Pathname of the root filesystem on the NFS server
5637 serverip - see above
5640 There are two special Environment Variables:
5642 serial# - contains hardware identification information such
5643 as type string and/or serial number
5644 ethaddr - Ethernet address
5646 These variables can be set only once (usually during manufacturing of
5647 the board). U-Boot refuses to delete or overwrite these variables
5648 once they have been set once.
5651 Further special Environment Variables:
5653 ver - Contains the U-Boot version string as printed
5654 with the "version" command. This variable is
5655 readonly (see CONFIG_VERSION_VARIABLE).
5658 Please note that changes to some configuration parameters may take
5659 only effect after the next boot (yes, that's just like Windoze :-).
5662 Callback functions for environment variables:
5663 ---------------------------------------------
5665 For some environment variables, the behavior of u-boot needs to change
5666 when their values are changed. This functionality allows functions to
5667 be associated with arbitrary variables. On creation, overwrite, or
5668 deletion, the callback will provide the opportunity for some side
5669 effect to happen or for the change to be rejected.
5671 The callbacks are named and associated with a function using the
5672 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5674 These callbacks are associated with variables in one of two ways. The
5675 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5676 in the board configuration to a string that defines a list of
5677 associations. The list must be in the following format:
5679 entry = variable_name[:callback_name]
5682 If the callback name is not specified, then the callback is deleted.
5683 Spaces are also allowed anywhere in the list.
5685 Callbacks can also be associated by defining the ".callbacks" variable
5686 with the same list format above. Any association in ".callbacks" will
5687 override any association in the static list. You can define
5688 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5689 ".callbacks" environment variable in the default or embedded environment.
5692 Command Line Parsing:
5693 =====================
5695 There are two different command line parsers available with U-Boot:
5696 the old "simple" one, and the much more powerful "hush" shell:
5698 Old, simple command line parser:
5699 --------------------------------
5701 - supports environment variables (through setenv / saveenv commands)
5702 - several commands on one line, separated by ';'
5703 - variable substitution using "... ${name} ..." syntax
5704 - special characters ('$', ';') can be escaped by prefixing with '\',
5706 setenv bootcmd bootm \${address}
5707 - You can also escape text by enclosing in single apostrophes, for example:
5708 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5713 - similar to Bourne shell, with control structures like
5714 if...then...else...fi, for...do...done; while...do...done,
5715 until...do...done, ...
5716 - supports environment ("global") variables (through setenv / saveenv
5717 commands) and local shell variables (through standard shell syntax
5718 "name=value"); only environment variables can be used with "run"
5724 (1) If a command line (or an environment variable executed by a "run"
5725 command) contains several commands separated by semicolon, and
5726 one of these commands fails, then the remaining commands will be
5729 (2) If you execute several variables with one call to run (i. e.
5730 calling run with a list of variables as arguments), any failing
5731 command will cause "run" to terminate, i. e. the remaining
5732 variables are not executed.
5734 Note for Redundant Ethernet Interfaces:
5735 =======================================
5737 Some boards come with redundant Ethernet interfaces; U-Boot supports
5738 such configurations and is capable of automatic selection of a
5739 "working" interface when needed. MAC assignment works as follows:
5741 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5742 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5743 "eth1addr" (=>eth1), "eth2addr", ...
5745 If the network interface stores some valid MAC address (for instance
5746 in SROM), this is used as default address if there is NO correspon-
5747 ding setting in the environment; if the corresponding environment
5748 variable is set, this overrides the settings in the card; that means:
5750 o If the SROM has a valid MAC address, and there is no address in the
5751 environment, the SROM's address is used.
5753 o If there is no valid address in the SROM, and a definition in the
5754 environment exists, then the value from the environment variable is
5757 o If both the SROM and the environment contain a MAC address, and
5758 both addresses are the same, this MAC address is used.
5760 o If both the SROM and the environment contain a MAC address, and the
5761 addresses differ, the value from the environment is used and a
5764 o If neither SROM nor the environment contain a MAC address, an error
5767 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5768 will be programmed into hardware as part of the initialization process. This
5769 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5770 The naming convention is as follows:
5771 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5776 U-Boot is capable of booting (and performing other auxiliary operations on)
5777 images in two formats:
5779 New uImage format (FIT)
5780 -----------------------
5782 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5783 to Flattened Device Tree). It allows the use of images with multiple
5784 components (several kernels, ramdisks, etc.), with contents protected by
5785 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5791 Old image format is based on binary files which can be basically anything,
5792 preceded by a special header; see the definitions in include/image.h for
5793 details; basically, the header defines the following image properties:
5795 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5796 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5797 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5798 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5800 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5801 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5802 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5803 * Compression Type (uncompressed, gzip, bzip2)
5809 The header is marked by a special Magic Number, and both the header
5810 and the data portions of the image are secured against corruption by
5817 Although U-Boot should support any OS or standalone application
5818 easily, the main focus has always been on Linux during the design of
5821 U-Boot includes many features that so far have been part of some
5822 special "boot loader" code within the Linux kernel. Also, any
5823 "initrd" images to be used are no longer part of one big Linux image;
5824 instead, kernel and "initrd" are separate images. This implementation
5825 serves several purposes:
5827 - the same features can be used for other OS or standalone
5828 applications (for instance: using compressed images to reduce the
5829 Flash memory footprint)
5831 - it becomes much easier to port new Linux kernel versions because
5832 lots of low-level, hardware dependent stuff are done by U-Boot
5834 - the same Linux kernel image can now be used with different "initrd"
5835 images; of course this also means that different kernel images can
5836 be run with the same "initrd". This makes testing easier (you don't
5837 have to build a new "zImage.initrd" Linux image when you just
5838 change a file in your "initrd"). Also, a field-upgrade of the
5839 software is easier now.
5845 Porting Linux to U-Boot based systems:
5846 ---------------------------------------
5848 U-Boot cannot save you from doing all the necessary modifications to
5849 configure the Linux device drivers for use with your target hardware
5850 (no, we don't intend to provide a full virtual machine interface to
5853 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5855 Just make sure your machine specific header file (for instance
5856 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5857 Information structure as we define in include/asm-<arch>/u-boot.h,
5858 and make sure that your definition of IMAP_ADDR uses the same value
5859 as your U-Boot configuration in CONFIG_SYS_IMMR.
5861 Note that U-Boot now has a driver model, a unified model for drivers.
5862 If you are adding a new driver, plumb it into driver model. If there
5863 is no uclass available, you are encouraged to create one. See
5867 Configuring the Linux kernel:
5868 -----------------------------
5870 No specific requirements for U-Boot. Make sure you have some root
5871 device (initial ramdisk, NFS) for your target system.
5874 Building a Linux Image:
5875 -----------------------
5877 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5878 not used. If you use recent kernel source, a new build target
5879 "uImage" will exist which automatically builds an image usable by
5880 U-Boot. Most older kernels also have support for a "pImage" target,
5881 which was introduced for our predecessor project PPCBoot and uses a
5882 100% compatible format.
5886 make TQM850L_defconfig
5891 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5892 encapsulate a compressed Linux kernel image with header information,
5893 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5895 * build a standard "vmlinux" kernel image (in ELF binary format):
5897 * convert the kernel into a raw binary image:
5899 ${CROSS_COMPILE}-objcopy -O binary \
5900 -R .note -R .comment \
5901 -S vmlinux linux.bin
5903 * compress the binary image:
5907 * package compressed binary image for U-Boot:
5909 mkimage -A ppc -O linux -T kernel -C gzip \
5910 -a 0 -e 0 -n "Linux Kernel Image" \
5911 -d linux.bin.gz uImage
5914 The "mkimage" tool can also be used to create ramdisk images for use
5915 with U-Boot, either separated from the Linux kernel image, or
5916 combined into one file. "mkimage" encapsulates the images with a 64
5917 byte header containing information about target architecture,
5918 operating system, image type, compression method, entry points, time
5919 stamp, CRC32 checksums, etc.
5921 "mkimage" can be called in two ways: to verify existing images and
5922 print the header information, or to build new images.
5924 In the first form (with "-l" option) mkimage lists the information
5925 contained in the header of an existing U-Boot image; this includes
5926 checksum verification:
5928 tools/mkimage -l image
5929 -l ==> list image header information
5931 The second form (with "-d" option) is used to build a U-Boot image
5932 from a "data file" which is used as image payload:
5934 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5935 -n name -d data_file image
5936 -A ==> set architecture to 'arch'
5937 -O ==> set operating system to 'os'
5938 -T ==> set image type to 'type'
5939 -C ==> set compression type 'comp'
5940 -a ==> set load address to 'addr' (hex)
5941 -e ==> set entry point to 'ep' (hex)
5942 -n ==> set image name to 'name'
5943 -d ==> use image data from 'datafile'
5945 Right now, all Linux kernels for PowerPC systems use the same load
5946 address (0x00000000), but the entry point address depends on the
5949 - 2.2.x kernels have the entry point at 0x0000000C,
5950 - 2.3.x and later kernels have the entry point at 0x00000000.
5952 So a typical call to build a U-Boot image would read:
5954 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5955 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5956 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5957 > examples/uImage.TQM850L
5958 Image Name: 2.4.4 kernel for TQM850L
5959 Created: Wed Jul 19 02:34:59 2000
5960 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5961 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5962 Load Address: 0x00000000
5963 Entry Point: 0x00000000
5965 To verify the contents of the image (or check for corruption):
5967 -> tools/mkimage -l examples/uImage.TQM850L
5968 Image Name: 2.4.4 kernel for TQM850L
5969 Created: Wed Jul 19 02:34:59 2000
5970 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5971 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5972 Load Address: 0x00000000
5973 Entry Point: 0x00000000
5975 NOTE: for embedded systems where boot time is critical you can trade
5976 speed for memory and install an UNCOMPRESSED image instead: this
5977 needs more space in Flash, but boots much faster since it does not
5978 need to be uncompressed:
5980 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5981 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5982 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5983 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5984 > examples/uImage.TQM850L-uncompressed
5985 Image Name: 2.4.4 kernel for TQM850L
5986 Created: Wed Jul 19 02:34:59 2000
5987 Image Type: PowerPC Linux Kernel Image (uncompressed)
5988 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5989 Load Address: 0x00000000
5990 Entry Point: 0x00000000
5993 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5994 when your kernel is intended to use an initial ramdisk:
5996 -> tools/mkimage -n 'Simple Ramdisk Image' \
5997 > -A ppc -O linux -T ramdisk -C gzip \
5998 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5999 Image Name: Simple Ramdisk Image
6000 Created: Wed Jan 12 14:01:50 2000
6001 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6002 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6003 Load Address: 0x00000000
6004 Entry Point: 0x00000000
6006 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6007 option performs the converse operation of the mkimage's second form (the "-d"
6008 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6011 tools/dumpimage -i image -T type -p position data_file
6012 -i ==> extract from the 'image' a specific 'data_file'
6013 -T ==> set image type to 'type'
6014 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6017 Installing a Linux Image:
6018 -------------------------
6020 To downloading a U-Boot image over the serial (console) interface,
6021 you must convert the image to S-Record format:
6023 objcopy -I binary -O srec examples/image examples/image.srec
6025 The 'objcopy' does not understand the information in the U-Boot
6026 image header, so the resulting S-Record file will be relative to
6027 address 0x00000000. To load it to a given address, you need to
6028 specify the target address as 'offset' parameter with the 'loads'
6031 Example: install the image to address 0x40100000 (which on the
6032 TQM8xxL is in the first Flash bank):
6034 => erase 40100000 401FFFFF
6040 ## Ready for S-Record download ...
6041 ~>examples/image.srec
6042 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6044 15989 15990 15991 15992
6045 [file transfer complete]
6047 ## Start Addr = 0x00000000
6050 You can check the success of the download using the 'iminfo' command;
6051 this includes a checksum verification so you can be sure no data
6052 corruption happened:
6056 ## Checking Image at 40100000 ...
6057 Image Name: 2.2.13 for initrd on TQM850L
6058 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6059 Data Size: 335725 Bytes = 327 kB = 0 MB
6060 Load Address: 00000000
6061 Entry Point: 0000000c
6062 Verifying Checksum ... OK
6068 The "bootm" command is used to boot an application that is stored in
6069 memory (RAM or Flash). In case of a Linux kernel image, the contents
6070 of the "bootargs" environment variable is passed to the kernel as
6071 parameters. You can check and modify this variable using the
6072 "printenv" and "setenv" commands:
6075 => printenv bootargs
6076 bootargs=root=/dev/ram
6078 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6080 => printenv bootargs
6081 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6084 ## Booting Linux kernel at 40020000 ...
6085 Image Name: 2.2.13 for NFS on TQM850L
6086 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6087 Data Size: 381681 Bytes = 372 kB = 0 MB
6088 Load Address: 00000000
6089 Entry Point: 0000000c
6090 Verifying Checksum ... OK
6091 Uncompressing Kernel Image ... OK
6092 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
6093 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6094 time_init: decrementer frequency = 187500000/60
6095 Calibrating delay loop... 49.77 BogoMIPS
6096 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6099 If you want to boot a Linux kernel with initial RAM disk, you pass
6100 the memory addresses of both the kernel and the initrd image (PPBCOOT
6101 format!) to the "bootm" command:
6103 => imi 40100000 40200000
6105 ## Checking Image at 40100000 ...
6106 Image Name: 2.2.13 for initrd on TQM850L
6107 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6108 Data Size: 335725 Bytes = 327 kB = 0 MB
6109 Load Address: 00000000
6110 Entry Point: 0000000c
6111 Verifying Checksum ... OK
6113 ## Checking Image at 40200000 ...
6114 Image Name: Simple Ramdisk Image
6115 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6116 Data Size: 566530 Bytes = 553 kB = 0 MB
6117 Load Address: 00000000
6118 Entry Point: 00000000
6119 Verifying Checksum ... OK
6121 => bootm 40100000 40200000
6122 ## Booting Linux kernel at 40100000 ...
6123 Image Name: 2.2.13 for initrd on TQM850L
6124 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6125 Data Size: 335725 Bytes = 327 kB = 0 MB
6126 Load Address: 00000000
6127 Entry Point: 0000000c
6128 Verifying Checksum ... OK
6129 Uncompressing Kernel Image ... OK
6130 ## Loading RAMDisk Image at 40200000 ...
6131 Image Name: Simple Ramdisk Image
6132 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6133 Data Size: 566530 Bytes = 553 kB = 0 MB
6134 Load Address: 00000000
6135 Entry Point: 00000000
6136 Verifying Checksum ... OK
6137 Loading Ramdisk ... OK
6138 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
6139 Boot arguments: root=/dev/ram
6140 time_init: decrementer frequency = 187500000/60
6141 Calibrating delay loop... 49.77 BogoMIPS
6143 RAMDISK: Compressed image found at block 0
6144 VFS: Mounted root (ext2 filesystem).
6148 Boot Linux and pass a flat device tree:
6151 First, U-Boot must be compiled with the appropriate defines. See the section
6152 titled "Linux Kernel Interface" above for a more in depth explanation. The
6153 following is an example of how to start a kernel and pass an updated
6159 oft=oftrees/mpc8540ads.dtb
6160 => tftp $oftaddr $oft
6161 Speed: 1000, full duplex
6163 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6164 Filename 'oftrees/mpc8540ads.dtb'.
6165 Load address: 0x300000
6168 Bytes transferred = 4106 (100a hex)
6169 => tftp $loadaddr $bootfile
6170 Speed: 1000, full duplex
6172 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6174 Load address: 0x200000
6175 Loading:############
6177 Bytes transferred = 1029407 (fb51f hex)
6182 => bootm $loadaddr - $oftaddr
6183 ## Booting image at 00200000 ...
6184 Image Name: Linux-2.6.17-dirty
6185 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6186 Data Size: 1029343 Bytes = 1005.2 kB
6187 Load Address: 00000000
6188 Entry Point: 00000000
6189 Verifying Checksum ... OK
6190 Uncompressing Kernel Image ... OK
6191 Booting using flat device tree at 0x300000
6192 Using MPC85xx ADS machine description
6193 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6197 More About U-Boot Image Types:
6198 ------------------------------
6200 U-Boot supports the following image types:
6202 "Standalone Programs" are directly runnable in the environment
6203 provided by U-Boot; it is expected that (if they behave
6204 well) you can continue to work in U-Boot after return from
6205 the Standalone Program.
6206 "OS Kernel Images" are usually images of some Embedded OS which
6207 will take over control completely. Usually these programs
6208 will install their own set of exception handlers, device
6209 drivers, set up the MMU, etc. - this means, that you cannot
6210 expect to re-enter U-Boot except by resetting the CPU.
6211 "RAMDisk Images" are more or less just data blocks, and their
6212 parameters (address, size) are passed to an OS kernel that is
6214 "Multi-File Images" contain several images, typically an OS
6215 (Linux) kernel image and one or more data images like
6216 RAMDisks. This construct is useful for instance when you want
6217 to boot over the network using BOOTP etc., where the boot
6218 server provides just a single image file, but you want to get
6219 for instance an OS kernel and a RAMDisk image.
6221 "Multi-File Images" start with a list of image sizes, each
6222 image size (in bytes) specified by an "uint32_t" in network
6223 byte order. This list is terminated by an "(uint32_t)0".
6224 Immediately after the terminating 0 follow the images, one by
6225 one, all aligned on "uint32_t" boundaries (size rounded up to
6226 a multiple of 4 bytes).
6228 "Firmware Images" are binary images containing firmware (like
6229 U-Boot or FPGA images) which usually will be programmed to
6232 "Script files" are command sequences that will be executed by
6233 U-Boot's command interpreter; this feature is especially
6234 useful when you configure U-Boot to use a real shell (hush)
6235 as command interpreter.
6237 Booting the Linux zImage:
6238 -------------------------
6240 On some platforms, it's possible to boot Linux zImage. This is done
6241 using the "bootz" command. The syntax of "bootz" command is the same
6242 as the syntax of "bootm" command.
6244 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6245 kernel with raw initrd images. The syntax is slightly different, the
6246 address of the initrd must be augmented by it's size, in the following
6247 format: "<initrd addres>:<initrd size>".
6253 One of the features of U-Boot is that you can dynamically load and
6254 run "standalone" applications, which can use some resources of
6255 U-Boot like console I/O functions or interrupt services.
6257 Two simple examples are included with the sources:
6262 'examples/hello_world.c' contains a small "Hello World" Demo
6263 application; it is automatically compiled when you build U-Boot.
6264 It's configured to run at address 0x00040004, so you can play with it
6268 ## Ready for S-Record download ...
6269 ~>examples/hello_world.srec
6270 1 2 3 4 5 6 7 8 9 10 11 ...
6271 [file transfer complete]
6273 ## Start Addr = 0x00040004
6275 => go 40004 Hello World! This is a test.
6276 ## Starting application at 0x00040004 ...
6287 Hit any key to exit ...
6289 ## Application terminated, rc = 0x0
6291 Another example, which demonstrates how to register a CPM interrupt
6292 handler with the U-Boot code, can be found in 'examples/timer.c'.
6293 Here, a CPM timer is set up to generate an interrupt every second.
6294 The interrupt service routine is trivial, just printing a '.'
6295 character, but this is just a demo program. The application can be
6296 controlled by the following keys:
6298 ? - print current values og the CPM Timer registers
6299 b - enable interrupts and start timer
6300 e - stop timer and disable interrupts
6301 q - quit application
6304 ## Ready for S-Record download ...
6305 ~>examples/timer.srec
6306 1 2 3 4 5 6 7 8 9 10 11 ...
6307 [file transfer complete]
6309 ## Start Addr = 0x00040004
6312 ## Starting application at 0x00040004 ...
6315 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6318 [q, b, e, ?] Set interval 1000000 us
6321 [q, b, e, ?] ........
6322 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6325 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6328 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6331 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6333 [q, b, e, ?] ...Stopping timer
6335 [q, b, e, ?] ## Application terminated, rc = 0x0
6341 Over time, many people have reported problems when trying to use the
6342 "minicom" terminal emulation program for serial download. I (wd)
6343 consider minicom to be broken, and recommend not to use it. Under
6344 Unix, I recommend to use C-Kermit for general purpose use (and
6345 especially for kermit binary protocol download ("loadb" command), and
6346 use "cu" for S-Record download ("loads" command). See
6347 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6348 for help with kermit.
6351 Nevertheless, if you absolutely want to use it try adding this
6352 configuration to your "File transfer protocols" section:
6354 Name Program Name U/D FullScr IO-Red. Multi
6355 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6356 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6362 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6363 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6365 Building requires a cross environment; it is known to work on
6366 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6367 need gmake since the Makefiles are not compatible with BSD make).
6368 Note that the cross-powerpc package does not install include files;
6369 attempting to build U-Boot will fail because <machine/ansi.h> is
6370 missing. This file has to be installed and patched manually:
6372 # cd /usr/pkg/cross/powerpc-netbsd/include
6374 # ln -s powerpc machine
6375 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6376 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6378 Native builds *don't* work due to incompatibilities between native
6379 and U-Boot include files.
6381 Booting assumes that (the first part of) the image booted is a
6382 stage-2 loader which in turn loads and then invokes the kernel
6383 proper. Loader sources will eventually appear in the NetBSD source
6384 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6385 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6388 Implementation Internals:
6389 =========================
6391 The following is not intended to be a complete description of every
6392 implementation detail. However, it should help to understand the
6393 inner workings of U-Boot and make it easier to port it to custom
6397 Initial Stack, Global Data:
6398 ---------------------------
6400 The implementation of U-Boot is complicated by the fact that U-Boot
6401 starts running out of ROM (flash memory), usually without access to
6402 system RAM (because the memory controller is not initialized yet).
6403 This means that we don't have writable Data or BSS segments, and BSS
6404 is not initialized as zero. To be able to get a C environment working
6405 at all, we have to allocate at least a minimal stack. Implementation
6406 options for this are defined and restricted by the CPU used: Some CPU
6407 models provide on-chip memory (like the IMMR area on MPC8xx and
6408 MPC826x processors), on others (parts of) the data cache can be
6409 locked as (mis-) used as memory, etc.
6411 Chris Hallinan posted a good summary of these issues to the
6412 U-Boot mailing list:
6414 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6415 From: "Chris Hallinan" <clh@net1plus.com>
6416 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6419 Correct me if I'm wrong, folks, but the way I understand it
6420 is this: Using DCACHE as initial RAM for Stack, etc, does not
6421 require any physical RAM backing up the cache. The cleverness
6422 is that the cache is being used as a temporary supply of
6423 necessary storage before the SDRAM controller is setup. It's
6424 beyond the scope of this list to explain the details, but you
6425 can see how this works by studying the cache architecture and
6426 operation in the architecture and processor-specific manuals.
6428 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6429 is another option for the system designer to use as an
6430 initial stack/RAM area prior to SDRAM being available. Either
6431 option should work for you. Using CS 4 should be fine if your
6432 board designers haven't used it for something that would
6433 cause you grief during the initial boot! It is frequently not
6436 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6437 with your processor/board/system design. The default value
6438 you will find in any recent u-boot distribution in
6439 walnut.h should work for you. I'd set it to a value larger
6440 than your SDRAM module. If you have a 64MB SDRAM module, set
6441 it above 400_0000. Just make sure your board has no resources
6442 that are supposed to respond to that address! That code in
6443 start.S has been around a while and should work as is when
6444 you get the config right.
6449 It is essential to remember this, since it has some impact on the C
6450 code for the initialization procedures:
6452 * Initialized global data (data segment) is read-only. Do not attempt
6455 * Do not use any uninitialized global data (or implicitly initialized
6456 as zero data - BSS segment) at all - this is undefined, initiali-
6457 zation is performed later (when relocating to RAM).
6459 * Stack space is very limited. Avoid big data buffers or things like
6462 Having only the stack as writable memory limits means we cannot use
6463 normal global data to share information between the code. But it
6464 turned out that the implementation of U-Boot can be greatly
6465 simplified by making a global data structure (gd_t) available to all
6466 functions. We could pass a pointer to this data as argument to _all_
6467 functions, but this would bloat the code. Instead we use a feature of
6468 the GCC compiler (Global Register Variables) to share the data: we
6469 place a pointer (gd) to the global data into a register which we
6470 reserve for this purpose.
6472 When choosing a register for such a purpose we are restricted by the
6473 relevant (E)ABI specifications for the current architecture, and by
6474 GCC's implementation.
6476 For PowerPC, the following registers have specific use:
6478 R2: reserved for system use
6479 R3-R4: parameter passing and return values
6480 R5-R10: parameter passing
6481 R13: small data area pointer
6485 (U-Boot also uses R12 as internal GOT pointer. r12
6486 is a volatile register so r12 needs to be reset when
6487 going back and forth between asm and C)
6489 ==> U-Boot will use R2 to hold a pointer to the global data
6491 Note: on PPC, we could use a static initializer (since the
6492 address of the global data structure is known at compile time),
6493 but it turned out that reserving a register results in somewhat
6494 smaller code - although the code savings are not that big (on
6495 average for all boards 752 bytes for the whole U-Boot image,
6496 624 text + 127 data).
6498 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6499 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6501 ==> U-Boot will use P3 to hold a pointer to the global data
6503 On ARM, the following registers are used:
6505 R0: function argument word/integer result
6506 R1-R3: function argument word
6507 R9: platform specific
6508 R10: stack limit (used only if stack checking is enabled)
6509 R11: argument (frame) pointer
6510 R12: temporary workspace
6513 R15: program counter
6515 ==> U-Boot will use R9 to hold a pointer to the global data
6517 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6519 On Nios II, the ABI is documented here:
6520 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6522 ==> U-Boot will use gp to hold a pointer to the global data
6524 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6525 to access small data sections, so gp is free.
6527 On NDS32, the following registers are used:
6529 R0-R1: argument/return
6531 R15: temporary register for assembler
6532 R16: trampoline register
6533 R28: frame pointer (FP)
6534 R29: global pointer (GP)
6535 R30: link register (LP)
6536 R31: stack pointer (SP)
6537 PC: program counter (PC)
6539 ==> U-Boot will use R10 to hold a pointer to the global data
6541 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6542 or current versions of GCC may "optimize" the code too much.
6547 U-Boot runs in system state and uses physical addresses, i.e. the
6548 MMU is not used either for address mapping nor for memory protection.
6550 The available memory is mapped to fixed addresses using the memory
6551 controller. In this process, a contiguous block is formed for each
6552 memory type (Flash, SDRAM, SRAM), even when it consists of several
6553 physical memory banks.
6555 U-Boot is installed in the first 128 kB of the first Flash bank (on
6556 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6557 booting and sizing and initializing DRAM, the code relocates itself
6558 to the upper end of DRAM. Immediately below the U-Boot code some
6559 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6560 configuration setting]. Below that, a structure with global Board
6561 Info data is placed, followed by the stack (growing downward).
6563 Additionally, some exception handler code is copied to the low 8 kB
6564 of DRAM (0x00000000 ... 0x00001FFF).
6566 So a typical memory configuration with 16 MB of DRAM could look like
6569 0x0000 0000 Exception Vector code
6572 0x0000 2000 Free for Application Use
6578 0x00FB FF20 Monitor Stack (Growing downward)
6579 0x00FB FFAC Board Info Data and permanent copy of global data
6580 0x00FC 0000 Malloc Arena
6583 0x00FE 0000 RAM Copy of Monitor Code
6584 ... eventually: LCD or video framebuffer
6585 ... eventually: pRAM (Protected RAM - unchanged by reset)
6586 0x00FF FFFF [End of RAM]
6589 System Initialization:
6590 ----------------------
6592 In the reset configuration, U-Boot starts at the reset entry point
6593 (on most PowerPC systems at address 0x00000100). Because of the reset
6594 configuration for CS0# this is a mirror of the on board Flash memory.
6595 To be able to re-map memory U-Boot then jumps to its link address.
6596 To be able to implement the initialization code in C, a (small!)
6597 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6598 which provide such a feature like MPC8xx or MPC8260), or in a locked
6599 part of the data cache. After that, U-Boot initializes the CPU core,
6600 the caches and the SIU.
6602 Next, all (potentially) available memory banks are mapped using a
6603 preliminary mapping. For example, we put them on 512 MB boundaries
6604 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6605 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6606 programmed for SDRAM access. Using the temporary configuration, a
6607 simple memory test is run that determines the size of the SDRAM
6610 When there is more than one SDRAM bank, and the banks are of
6611 different size, the largest is mapped first. For equal size, the first
6612 bank (CS2#) is mapped first. The first mapping is always for address
6613 0x00000000, with any additional banks following immediately to create
6614 contiguous memory starting from 0.
6616 Then, the monitor installs itself at the upper end of the SDRAM area
6617 and allocates memory for use by malloc() and for the global Board
6618 Info data; also, the exception vector code is copied to the low RAM
6619 pages, and the final stack is set up.
6621 Only after this relocation will you have a "normal" C environment;
6622 until that you are restricted in several ways, mostly because you are
6623 running from ROM, and because the code will have to be relocated to a
6627 U-Boot Porting Guide:
6628 ----------------------
6630 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6634 int main(int argc, char *argv[])
6636 sighandler_t no_more_time;
6638 signal(SIGALRM, no_more_time);
6639 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6641 if (available_money > available_manpower) {
6642 Pay consultant to port U-Boot;
6646 Download latest U-Boot source;
6648 Subscribe to u-boot mailing list;
6651 email("Hi, I am new to U-Boot, how do I get started?");
6654 Read the README file in the top level directory;
6655 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6656 Read applicable doc/*.README;
6657 Read the source, Luke;
6658 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6661 if (available_money > toLocalCurrency ($2500))
6664 Add a lot of aggravation and time;
6666 if (a similar board exists) { /* hopefully... */
6667 cp -a board/<similar> board/<myboard>
6668 cp include/configs/<similar>.h include/configs/<myboard>.h
6670 Create your own board support subdirectory;
6671 Create your own board include/configs/<myboard>.h file;
6673 Edit new board/<myboard> files
6674 Edit new include/configs/<myboard>.h
6679 Add / modify source code;
6683 email("Hi, I am having problems...");
6685 Send patch file to the U-Boot email list;
6686 if (reasonable critiques)
6687 Incorporate improvements from email list code review;
6689 Defend code as written;
6695 void no_more_time (int sig)
6704 All contributions to U-Boot should conform to the Linux kernel
6705 coding style; see the file "Documentation/CodingStyle" and the script
6706 "scripts/Lindent" in your Linux kernel source directory.
6708 Source files originating from a different project (for example the
6709 MTD subsystem) are generally exempt from these guidelines and are not
6710 reformatted to ease subsequent migration to newer versions of those
6713 Please note that U-Boot is implemented in C (and to some small parts in
6714 Assembler); no C++ is used, so please do not use C++ style comments (//)
6717 Please also stick to the following formatting rules:
6718 - remove any trailing white space
6719 - use TAB characters for indentation and vertical alignment, not spaces
6720 - make sure NOT to use DOS '\r\n' line feeds
6721 - do not add more than 2 consecutive empty lines to source files
6722 - do not add trailing empty lines to source files
6724 Submissions which do not conform to the standards may be returned
6725 with a request to reformat the changes.
6731 Since the number of patches for U-Boot is growing, we need to
6732 establish some rules. Submissions which do not conform to these rules
6733 may be rejected, even when they contain important and valuable stuff.
6735 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6737 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6738 see http://lists.denx.de/mailman/listinfo/u-boot
6740 When you send a patch, please include the following information with
6743 * For bug fixes: a description of the bug and how your patch fixes
6744 this bug. Please try to include a way of demonstrating that the
6745 patch actually fixes something.
6747 * For new features: a description of the feature and your
6750 * A CHANGELOG entry as plaintext (separate from the patch)
6752 * For major contributions, your entry to the CREDITS file
6754 * When you add support for a new board, don't forget to add a
6755 maintainer e-mail address to the boards.cfg file, too.
6757 * If your patch adds new configuration options, don't forget to
6758 document these in the README file.
6760 * The patch itself. If you are using git (which is *strongly*
6761 recommended) you can easily generate the patch using the
6762 "git format-patch". If you then use "git send-email" to send it to
6763 the U-Boot mailing list, you will avoid most of the common problems
6764 with some other mail clients.
6766 If you cannot use git, use "diff -purN OLD NEW". If your version of
6767 diff does not support these options, then get the latest version of
6770 The current directory when running this command shall be the parent
6771 directory of the U-Boot source tree (i. e. please make sure that
6772 your patch includes sufficient directory information for the
6775 We prefer patches as plain text. MIME attachments are discouraged,
6776 and compressed attachments must not be used.
6778 * If one logical set of modifications affects or creates several
6779 files, all these changes shall be submitted in a SINGLE patch file.
6781 * Changesets that contain different, unrelated modifications shall be
6782 submitted as SEPARATE patches, one patch per changeset.
6787 * Before sending the patch, run the MAKEALL script on your patched
6788 source tree and make sure that no errors or warnings are reported
6789 for any of the boards.
6791 * Keep your modifications to the necessary minimum: A patch
6792 containing several unrelated changes or arbitrary reformats will be
6793 returned with a request to re-formatting / split it.
6795 * If you modify existing code, make sure that your new code does not
6796 add to the memory footprint of the code ;-) Small is beautiful!
6797 When adding new features, these should compile conditionally only
6798 (using #ifdef), and the resulting code with the new feature
6799 disabled must not need more memory than the old code without your
6802 * Remember that there is a size limit of 100 kB per message on the
6803 u-boot mailing list. Bigger patches will be moderated. If they are
6804 reasonable and not too big, they will be acknowledged. But patches
6805 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob