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_798870
699 CONFIG_TEGRA_SUPPORT_NON_SECURE
701 Support executing U-Boot in non-secure (NS) mode. Certain
702 impossible actions will be skipped if the CPU is in NS mode,
703 such as ARM architectural timer initialization.
706 Driver model is a new framework for devices in U-Boot
707 introduced in early 2014. U-Boot is being progressively
708 moved over to this. It offers a consistent device structure,
709 supports grouping devices into classes and has built-in
710 handling of platform data and device tree.
712 To enable transition to driver model in a relatively
713 painful fashion, each subsystem can be independently
714 switched between the legacy/ad-hoc approach and the new
715 driver model using the options below. Also, many uclass
716 interfaces include compatibility features which may be
717 removed once the conversion of that subsystem is complete.
718 As a result, the API provided by the subsystem may in fact
719 not change with driver model.
721 See doc/driver-model/README.txt for more information.
725 Enable driver model. This brings in the core support,
726 including scanning of platform data on start-up. If
727 CONFIG_OF_CONTROL is enabled, the device tree will be
728 scanned also when available.
732 Enable driver model test commands. These allow you to print
733 out the driver model tree and the uclasses.
737 Enable some demo devices and the 'demo' command. These are
738 really only useful for playing around while trying to
739 understand driver model in sandbox.
743 Enable driver model in SPL. You will need to provide a
744 suitable malloc() implementation. If you are not using the
745 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
746 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
747 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
748 In most cases driver model will only allocate a few uclasses
749 and devices in SPL, so 1KB should be enable. See
750 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
755 Enable driver model for serial. This replaces
756 drivers/serial/serial.c with the serial uclass, which
757 implements serial_putc() etc. The uclass interface is
758 defined in include/serial.h.
762 Enable driver model for GPIO access. The standard GPIO
763 interface (gpio_get_value(), etc.) is then implemented by
764 the GPIO uclass. Drivers provide methods to query the
765 particular GPIOs that they provide. The uclass interface
766 is defined in include/asm-generic/gpio.h.
770 Enable driver model for SPI. The SPI slave interface
771 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
772 the SPI uclass. Drivers provide methods to access the SPI
773 buses that they control. The uclass interface is defined in
774 include/spi.h. The existing spi_slave structure is attached
775 as 'parent data' to every slave on each bus. Slaves
776 typically use driver-private data instead of extending the
781 Enable driver model for SPI flash. This SPI flash interface
782 (spi_flash_probe(), spi_flash_write(), etc.) is then
783 implemented by the SPI flash uclass. There is one standard
784 SPI flash driver which knows how to probe most chips
785 supported by U-Boot. The uclass interface is defined in
786 include/spi_flash.h, but is currently fully compatible
787 with the old interface to avoid confusion and duplication
788 during the transition parent. SPI and SPI flash must be
789 enabled together (it is not possible to use driver model
790 for one and not the other).
794 Enable driver model for the Chrome OS EC interface. This
795 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
796 but otherwise makes few changes. Since cros_ec also supports
797 I2C and LPC (which don't support driver model yet), a full
798 conversion is not yet possible.
801 ** Code size options: The following options are enabled by
802 default except in SPL. Enable them explicitly to get these
807 Enable the dm_warn() function. This can use up quite a bit
808 of space for its strings.
812 Enable registering a serial device with the stdio library.
814 CONFIG_DM_DEVICE_REMOVE
816 Enable removing of devices.
818 - Linux Kernel Interface:
821 U-Boot stores all clock information in Hz
822 internally. For binary compatibility with older Linux
823 kernels (which expect the clocks passed in the
824 bd_info data to be in MHz) the environment variable
825 "clocks_in_mhz" can be defined so that U-Boot
826 converts clock data to MHZ before passing it to the
828 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
829 "clocks_in_mhz=1" is automatically included in the
832 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
834 When transferring memsize parameter to Linux, some versions
835 expect it to be in bytes, others in MB.
836 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
840 New kernel versions are expecting firmware settings to be
841 passed using flattened device trees (based on open firmware
845 * New libfdt-based support
846 * Adds the "fdt" command
847 * The bootm command automatically updates the fdt
849 OF_CPU - The proper name of the cpus node (only required for
850 MPC512X and MPC5xxx based boards).
851 OF_SOC - The proper name of the soc node (only required for
852 MPC512X and MPC5xxx based boards).
853 OF_TBCLK - The timebase frequency.
854 OF_STDOUT_PATH - The path to the console device
856 boards with QUICC Engines require OF_QE to set UCC MAC
859 CONFIG_OF_BOARD_SETUP
861 Board code has addition modification that it wants to make
862 to the flat device tree before handing it off to the kernel
864 CONFIG_OF_SYSTEM_SETUP
866 Other code has addition modification that it wants to make
867 to the flat device tree before handing it off to the kernel.
868 This causes ft_system_setup() to be called before booting
873 This define fills in the correct boot CPU in the boot
874 param header, the default value is zero if undefined.
878 U-Boot can detect if an IDE device is present or not.
879 If not, and this new config option is activated, U-Boot
880 removes the ATA node from the DTS before booting Linux,
881 so the Linux IDE driver does not probe the device and
882 crash. This is needed for buggy hardware (uc101) where
883 no pull down resistor is connected to the signal IDE5V_DD7.
885 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
887 This setting is mandatory for all boards that have only one
888 machine type and must be used to specify the machine type
889 number as it appears in the ARM machine registry
890 (see http://www.arm.linux.org.uk/developer/machines/).
891 Only boards that have multiple machine types supported
892 in a single configuration file and the machine type is
893 runtime discoverable, do not have to use this setting.
895 - vxWorks boot parameters:
897 bootvx constructs a valid bootline using the following
898 environments variables: bootfile, ipaddr, serverip, hostname.
899 It loads the vxWorks image pointed bootfile.
901 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
902 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
903 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
904 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
906 CONFIG_SYS_VXWORKS_ADD_PARAMS
908 Add it at the end of the bootline. E.g "u=username pw=secret"
910 Note: If a "bootargs" environment is defined, it will overwride
911 the defaults discussed just above.
913 - Cache Configuration:
914 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
915 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
916 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
918 - Cache Configuration for ARM:
919 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
921 CONFIG_SYS_PL310_BASE - Physical base address of PL310
922 controller register space
927 Define this if you want support for Amba PrimeCell PL010 UARTs.
931 Define this if you want support for Amba PrimeCell PL011 UARTs.
935 If you have Amba PrimeCell PL011 UARTs, set this variable to
936 the clock speed of the UARTs.
940 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
941 define this to a list of base addresses for each (supported)
942 port. See e.g. include/configs/versatile.h
944 CONFIG_PL011_SERIAL_RLCR
946 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
947 have separate receive and transmit line control registers. Set
948 this variable to initialize the extra register.
950 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
952 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
953 boot loader that has already initialized the UART. Define this
954 variable to flush the UART at init time.
956 CONFIG_SERIAL_HW_FLOW_CONTROL
958 Define this variable to enable hw flow control in serial driver.
959 Current user of this option is drivers/serial/nsl16550.c driver
962 Depending on board, define exactly one serial port
963 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
964 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
965 console by defining CONFIG_8xx_CONS_NONE
967 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
968 port routines must be defined elsewhere
969 (i.e. serial_init(), serial_getc(), ...)
972 Enables console device for a color framebuffer. Needs following
973 defines (cf. smiLynxEM, i8042)
974 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
976 VIDEO_HW_RECTFILL graphic chip supports
979 VIDEO_HW_BITBLT graphic chip supports
980 bit-blit (cf. smiLynxEM)
981 VIDEO_VISIBLE_COLS visible pixel columns
983 VIDEO_VISIBLE_ROWS visible pixel rows
984 VIDEO_PIXEL_SIZE bytes per pixel
985 VIDEO_DATA_FORMAT graphic data format
986 (0-5, cf. cfb_console.c)
987 VIDEO_FB_ADRS framebuffer address
988 VIDEO_KBD_INIT_FCT keyboard int fct
989 (i.e. i8042_kbd_init())
990 VIDEO_TSTC_FCT test char fct
992 VIDEO_GETC_FCT get char fct
994 CONFIG_CONSOLE_CURSOR cursor drawing on/off
995 (requires blink timer
997 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
998 CONFIG_CONSOLE_TIME display time/date info in
1000 (requires CONFIG_CMD_DATE)
1001 CONFIG_VIDEO_LOGO display Linux logo in
1003 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1004 linux_logo.h for logo.
1005 Requires CONFIG_VIDEO_LOGO
1006 CONFIG_CONSOLE_EXTRA_INFO
1007 additional board info beside
1010 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1011 a limited number of ANSI escape sequences (cursor control,
1012 erase functions and limited graphics rendition control).
1014 When CONFIG_CFB_CONSOLE is defined, video console is
1015 default i/o. Serial console can be forced with
1016 environment 'console=serial'.
1018 When CONFIG_SILENT_CONSOLE is defined, all console
1019 messages (by U-Boot and Linux!) can be silenced with
1020 the "silent" environment variable. See
1021 doc/README.silent for more information.
1023 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1025 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1029 CONFIG_BAUDRATE - in bps
1030 Select one of the baudrates listed in
1031 CONFIG_SYS_BAUDRATE_TABLE, see below.
1032 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1034 - Console Rx buffer length
1035 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1036 the maximum receive buffer length for the SMC.
1037 This option is actual only for 82xx and 8xx possible.
1038 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1039 must be defined, to setup the maximum idle timeout for
1042 - Pre-Console Buffer:
1043 Prior to the console being initialised (i.e. serial UART
1044 initialised etc) all console output is silently discarded.
1045 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1046 buffer any console messages prior to the console being
1047 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1048 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1049 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1050 bytes are output before the console is initialised, the
1051 earlier bytes are discarded.
1053 'Sane' compilers will generate smaller code if
1054 CONFIG_PRE_CON_BUF_SZ is a power of 2
1056 - Safe printf() functions
1057 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1058 the printf() functions. These are defined in
1059 include/vsprintf.h and include snprintf(), vsnprintf() and
1060 so on. Code size increase is approximately 300-500 bytes.
1061 If this option is not given then these functions will
1062 silently discard their buffer size argument - this means
1063 you are not getting any overflow checking in this case.
1065 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1066 Delay before automatically booting the default image;
1067 set to -1 to disable autoboot.
1068 set to -2 to autoboot with no delay and not check for abort
1069 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1071 See doc/README.autoboot for these options that
1072 work with CONFIG_BOOTDELAY. None are required.
1073 CONFIG_BOOT_RETRY_TIME
1074 CONFIG_BOOT_RETRY_MIN
1075 CONFIG_AUTOBOOT_KEYED
1076 CONFIG_AUTOBOOT_PROMPT
1077 CONFIG_AUTOBOOT_DELAY_STR
1078 CONFIG_AUTOBOOT_STOP_STR
1079 CONFIG_AUTOBOOT_DELAY_STR2
1080 CONFIG_AUTOBOOT_STOP_STR2
1081 CONFIG_ZERO_BOOTDELAY_CHECK
1082 CONFIG_RESET_TO_RETRY
1086 Only needed when CONFIG_BOOTDELAY is enabled;
1087 define a command string that is automatically executed
1088 when no character is read on the console interface
1089 within "Boot Delay" after reset.
1092 This can be used to pass arguments to the bootm
1093 command. The value of CONFIG_BOOTARGS goes into the
1094 environment value "bootargs".
1096 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1097 The value of these goes into the environment as
1098 "ramboot" and "nfsboot" respectively, and can be used
1099 as a convenience, when switching between booting from
1103 CONFIG_BOOTCOUNT_LIMIT
1104 Implements a mechanism for detecting a repeating reboot
1106 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1108 CONFIG_BOOTCOUNT_ENV
1109 If no softreset save registers are found on the hardware
1110 "bootcount" is stored in the environment. To prevent a
1111 saveenv on all reboots, the environment variable
1112 "upgrade_available" is used. If "upgrade_available" is
1113 0, "bootcount" is always 0, if "upgrade_available" is
1114 1 "bootcount" is incremented in the environment.
1115 So the Userspace Applikation must set the "upgrade_available"
1116 and "bootcount" variable to 0, if a boot was successfully.
1118 - Pre-Boot Commands:
1121 When this option is #defined, the existence of the
1122 environment variable "preboot" will be checked
1123 immediately before starting the CONFIG_BOOTDELAY
1124 countdown and/or running the auto-boot command resp.
1125 entering interactive mode.
1127 This feature is especially useful when "preboot" is
1128 automatically generated or modified. For an example
1129 see the LWMON board specific code: here "preboot" is
1130 modified when the user holds down a certain
1131 combination of keys on the (special) keyboard when
1134 - Serial Download Echo Mode:
1136 If defined to 1, all characters received during a
1137 serial download (using the "loads" command) are
1138 echoed back. This might be needed by some terminal
1139 emulations (like "cu"), but may as well just take
1140 time on others. This setting #define's the initial
1141 value of the "loads_echo" environment variable.
1143 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1144 CONFIG_KGDB_BAUDRATE
1145 Select one of the baudrates listed in
1146 CONFIG_SYS_BAUDRATE_TABLE, see below.
1148 - Monitor Functions:
1149 Monitor commands can be included or excluded
1150 from the build by using the #include files
1151 <config_cmd_all.h> and #undef'ing unwanted
1152 commands, or using <config_cmd_default.h>
1153 and augmenting with additional #define's
1154 for wanted commands.
1156 The default command configuration includes all commands
1157 except those marked below with a "*".
1159 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1160 CONFIG_CMD_ASKENV * ask for env variable
1161 CONFIG_CMD_BDI bdinfo
1162 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1163 CONFIG_CMD_BMP * BMP support
1164 CONFIG_CMD_BSP * Board specific commands
1165 CONFIG_CMD_BOOTD bootd
1166 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1167 CONFIG_CMD_CACHE * icache, dcache
1168 CONFIG_CMD_CLK * clock command support
1169 CONFIG_CMD_CONSOLE coninfo
1170 CONFIG_CMD_CRC32 * crc32
1171 CONFIG_CMD_DATE * support for RTC, date/time...
1172 CONFIG_CMD_DHCP * DHCP support
1173 CONFIG_CMD_DIAG * Diagnostics
1174 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1175 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1176 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1177 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1178 CONFIG_CMD_DTT * Digital Therm and Thermostat
1179 CONFIG_CMD_ECHO echo arguments
1180 CONFIG_CMD_EDITENV edit env variable
1181 CONFIG_CMD_EEPROM * EEPROM read/write support
1182 CONFIG_CMD_ELF * bootelf, bootvx
1183 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1184 CONFIG_CMD_ENV_FLAGS * display details about env flags
1185 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1186 CONFIG_CMD_EXPORTENV * export the environment
1187 CONFIG_CMD_EXT2 * ext2 command support
1188 CONFIG_CMD_EXT4 * ext4 command support
1189 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1190 that work for multiple fs types
1191 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1192 CONFIG_CMD_SAVEENV saveenv
1193 CONFIG_CMD_FDC * Floppy Disk Support
1194 CONFIG_CMD_FAT * FAT command support
1195 CONFIG_CMD_FLASH flinfo, erase, protect
1196 CONFIG_CMD_FPGA FPGA device initialization support
1197 CONFIG_CMD_FUSE * Device fuse support
1198 CONFIG_CMD_GETTIME * Get time since boot
1199 CONFIG_CMD_GO * the 'go' command (exec code)
1200 CONFIG_CMD_GREPENV * search environment
1201 CONFIG_CMD_HASH * calculate hash / digest
1202 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1203 CONFIG_CMD_I2C * I2C serial bus support
1204 CONFIG_CMD_IDE * IDE harddisk support
1205 CONFIG_CMD_IMI iminfo
1206 CONFIG_CMD_IMLS List all images found in NOR flash
1207 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1208 CONFIG_CMD_IMMAP * IMMR dump support
1209 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1210 CONFIG_CMD_IMPORTENV * import an environment
1211 CONFIG_CMD_INI * import data from an ini file into the env
1212 CONFIG_CMD_IRQ * irqinfo
1213 CONFIG_CMD_ITEST Integer/string test of 2 values
1214 CONFIG_CMD_JFFS2 * JFFS2 Support
1215 CONFIG_CMD_KGDB * kgdb
1216 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1217 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1219 CONFIG_CMD_LOADB loadb
1220 CONFIG_CMD_LOADS loads
1221 CONFIG_CMD_MD5SUM * print md5 message digest
1222 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1223 CONFIG_CMD_MEMINFO * Display detailed memory information
1224 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1226 CONFIG_CMD_MEMTEST * mtest
1227 CONFIG_CMD_MISC Misc functions like sleep etc
1228 CONFIG_CMD_MMC * MMC memory mapped support
1229 CONFIG_CMD_MII * MII utility commands
1230 CONFIG_CMD_MTDPARTS * MTD partition support
1231 CONFIG_CMD_NAND * NAND support
1232 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1233 CONFIG_CMD_NFS NFS support
1234 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1235 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1236 CONFIG_CMD_PCI * pciinfo
1237 CONFIG_CMD_PCMCIA * PCMCIA support
1238 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1240 CONFIG_CMD_PORTIO * Port I/O
1241 CONFIG_CMD_READ * Read raw data from partition
1242 CONFIG_CMD_REGINFO * Register dump
1243 CONFIG_CMD_RUN run command in env variable
1244 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1245 CONFIG_CMD_SAVES * save S record dump
1246 CONFIG_CMD_SCSI * SCSI Support
1247 CONFIG_CMD_SDRAM * print SDRAM configuration information
1248 (requires CONFIG_CMD_I2C)
1249 CONFIG_CMD_SETGETDCR Support for DCR Register access
1251 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1252 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1253 (requires CONFIG_CMD_MEMORY)
1254 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1255 CONFIG_CMD_SOURCE "source" command Support
1256 CONFIG_CMD_SPI * SPI serial bus support
1257 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1258 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1259 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1260 CONFIG_CMD_TIMER * access to the system tick timer
1261 CONFIG_CMD_USB * USB support
1262 CONFIG_CMD_CDP * Cisco Discover Protocol support
1263 CONFIG_CMD_MFSL * Microblaze FSL support
1264 CONFIG_CMD_XIMG Load part of Multi Image
1265 CONFIG_CMD_UUID * Generate random UUID or GUID string
1267 EXAMPLE: If you want all functions except of network
1268 support you can write:
1270 #include "config_cmd_all.h"
1271 #undef CONFIG_CMD_NET
1274 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1276 Note: Don't enable the "icache" and "dcache" commands
1277 (configuration option CONFIG_CMD_CACHE) unless you know
1278 what you (and your U-Boot users) are doing. Data
1279 cache cannot be enabled on systems like the 8xx or
1280 8260 (where accesses to the IMMR region must be
1281 uncached), and it cannot be disabled on all other
1282 systems where we (mis-) use the data cache to hold an
1283 initial stack and some data.
1286 XXX - this list needs to get updated!
1288 - Regular expression support:
1290 If this variable is defined, U-Boot is linked against
1291 the SLRE (Super Light Regular Expression) library,
1292 which adds regex support to some commands, as for
1293 example "env grep" and "setexpr".
1297 If this variable is defined, U-Boot will use a device tree
1298 to configure its devices, instead of relying on statically
1299 compiled #defines in the board file. This option is
1300 experimental and only available on a few boards. The device
1301 tree is available in the global data as gd->fdt_blob.
1303 U-Boot needs to get its device tree from somewhere. This can
1304 be done using one of the two options below:
1307 If this variable is defined, U-Boot will embed a device tree
1308 binary in its image. This device tree file should be in the
1309 board directory and called <soc>-<board>.dts. The binary file
1310 is then picked up in board_init_f() and made available through
1311 the global data structure as gd->blob.
1314 If this variable is defined, U-Boot will build a device tree
1315 binary. It will be called u-boot.dtb. Architecture-specific
1316 code will locate it at run-time. Generally this works by:
1318 cat u-boot.bin u-boot.dtb >image.bin
1320 and in fact, U-Boot does this for you, creating a file called
1321 u-boot-dtb.bin which is useful in the common case. You can
1322 still use the individual files if you need something more
1327 If this variable is defined, it enables watchdog
1328 support for the SoC. There must be support in the SoC
1329 specific code for a watchdog. For the 8xx and 8260
1330 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1331 register. When supported for a specific SoC is
1332 available, then no further board specific code should
1333 be needed to use it.
1336 When using a watchdog circuitry external to the used
1337 SoC, then define this variable and provide board
1338 specific code for the "hw_watchdog_reset" function.
1340 CONFIG_AT91_HW_WDT_TIMEOUT
1341 specify the timeout in seconds. default 2 seconds.
1344 CONFIG_VERSION_VARIABLE
1345 If this variable is defined, an environment variable
1346 named "ver" is created by U-Boot showing the U-Boot
1347 version as printed by the "version" command.
1348 Any change to this variable will be reverted at the
1353 When CONFIG_CMD_DATE is selected, the type of the RTC
1354 has to be selected, too. Define exactly one of the
1357 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1358 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1359 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1360 CONFIG_RTC_MC146818 - use MC146818 RTC
1361 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1362 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1363 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1364 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1365 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1366 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1367 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1368 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1369 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1372 Note that if the RTC uses I2C, then the I2C interface
1373 must also be configured. See I2C Support, below.
1376 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1378 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1379 chip-ngpio pairs that tell the PCA953X driver the number of
1380 pins supported by a particular chip.
1382 Note that if the GPIO device uses I2C, then the I2C interface
1383 must also be configured. See I2C Support, below.
1386 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1387 accesses and can checksum them or write a list of them out
1388 to memory. See the 'iotrace' command for details. This is
1389 useful for testing device drivers since it can confirm that
1390 the driver behaves the same way before and after a code
1391 change. Currently this is supported on sandbox and arm. To
1392 add support for your architecture, add '#include <iotrace.h>'
1393 to the bottom of arch/<arch>/include/asm/io.h and test.
1395 Example output from the 'iotrace stats' command is below.
1396 Note that if the trace buffer is exhausted, the checksum will
1397 still continue to operate.
1400 Start: 10000000 (buffer start address)
1401 Size: 00010000 (buffer size)
1402 Offset: 00000120 (current buffer offset)
1403 Output: 10000120 (start + offset)
1404 Count: 00000018 (number of trace records)
1405 CRC32: 9526fb66 (CRC32 of all trace records)
1407 - Timestamp Support:
1409 When CONFIG_TIMESTAMP is selected, the timestamp
1410 (date and time) of an image is printed by image
1411 commands like bootm or iminfo. This option is
1412 automatically enabled when you select CONFIG_CMD_DATE .
1414 - Partition Labels (disklabels) Supported:
1415 Zero or more of the following:
1416 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1417 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1418 Intel architecture, USB sticks, etc.
1419 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1420 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1421 bootloader. Note 2TB partition limit; see
1423 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1425 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1426 CONFIG_CMD_SCSI) you must configure support for at
1427 least one non-MTD partition type as well.
1430 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1431 board configurations files but used nowhere!
1433 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1434 be performed by calling the function
1435 ide_set_reset(int reset)
1436 which has to be defined in a board specific file
1441 Set this to enable ATAPI support.
1446 Set this to enable support for disks larger than 137GB
1447 Also look at CONFIG_SYS_64BIT_LBA.
1448 Whithout these , LBA48 support uses 32bit variables and will 'only'
1449 support disks up to 2.1TB.
1451 CONFIG_SYS_64BIT_LBA:
1452 When enabled, makes the IDE subsystem use 64bit sector addresses.
1456 At the moment only there is only support for the
1457 SYM53C8XX SCSI controller; define
1458 CONFIG_SCSI_SYM53C8XX to enable it.
1460 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1461 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1462 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1463 maximum numbers of LUNs, SCSI ID's and target
1465 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1467 The environment variable 'scsidevs' is set to the number of
1468 SCSI devices found during the last scan.
1470 - NETWORK Support (PCI):
1472 Support for Intel 8254x/8257x gigabit chips.
1475 Utility code for direct access to the SPI bus on Intel 8257x.
1476 This does not do anything useful unless you set at least one
1477 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1479 CONFIG_E1000_SPI_GENERIC
1480 Allow generic access to the SPI bus on the Intel 8257x, for
1481 example with the "sspi" command.
1484 Management command for E1000 devices. When used on devices
1485 with SPI support you can reprogram the EEPROM from U-Boot.
1487 CONFIG_E1000_FALLBACK_MAC
1488 default MAC for empty EEPROM after production.
1491 Support for Intel 82557/82559/82559ER chips.
1492 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1493 write routine for first time initialisation.
1496 Support for Digital 2114x chips.
1497 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1498 modem chip initialisation (KS8761/QS6611).
1501 Support for National dp83815 chips.
1504 Support for National dp8382[01] gigabit chips.
1506 - NETWORK Support (other):
1508 CONFIG_DRIVER_AT91EMAC
1509 Support for AT91RM9200 EMAC.
1512 Define this to use reduced MII inteface
1514 CONFIG_DRIVER_AT91EMAC_QUIET
1515 If this defined, the driver is quiet.
1516 The driver doen't show link status messages.
1518 CONFIG_CALXEDA_XGMAC
1519 Support for the Calxeda XGMAC device
1522 Support for SMSC's LAN91C96 chips.
1524 CONFIG_LAN91C96_BASE
1525 Define this to hold the physical address
1526 of the LAN91C96's I/O space
1528 CONFIG_LAN91C96_USE_32_BIT
1529 Define this to enable 32 bit addressing
1532 Support for SMSC's LAN91C111 chip
1534 CONFIG_SMC91111_BASE
1535 Define this to hold the physical address
1536 of the device (I/O space)
1538 CONFIG_SMC_USE_32_BIT
1539 Define this if data bus is 32 bits
1541 CONFIG_SMC_USE_IOFUNCS
1542 Define this to use i/o functions instead of macros
1543 (some hardware wont work with macros)
1545 CONFIG_DRIVER_TI_EMAC
1546 Support for davinci emac
1548 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1549 Define this if you have more then 3 PHYs.
1552 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1554 CONFIG_FTGMAC100_EGIGA
1555 Define this to use GE link update with gigabit PHY.
1556 Define this if FTGMAC100 is connected to gigabit PHY.
1557 If your system has 10/100 PHY only, it might not occur
1558 wrong behavior. Because PHY usually return timeout or
1559 useless data when polling gigabit status and gigabit
1560 control registers. This behavior won't affect the
1561 correctnessof 10/100 link speed update.
1564 Support for SMSC's LAN911x and LAN921x chips
1567 Define this to hold the physical address
1568 of the device (I/O space)
1570 CONFIG_SMC911X_32_BIT
1571 Define this if data bus is 32 bits
1573 CONFIG_SMC911X_16_BIT
1574 Define this if data bus is 16 bits. If your processor
1575 automatically converts one 32 bit word to two 16 bit
1576 words you may also try CONFIG_SMC911X_32_BIT.
1579 Support for Renesas on-chip Ethernet controller
1581 CONFIG_SH_ETHER_USE_PORT
1582 Define the number of ports to be used
1584 CONFIG_SH_ETHER_PHY_ADDR
1585 Define the ETH PHY's address
1587 CONFIG_SH_ETHER_CACHE_WRITEBACK
1588 If this option is set, the driver enables cache flush.
1592 Support for PWM modul on the imx6.
1596 Support TPM devices.
1599 Support for i2c bus TPM devices. Only one device
1600 per system is supported at this time.
1602 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1603 Define the the i2c bus number for the TPM device
1605 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1606 Define the TPM's address on the i2c bus
1608 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1609 Define the burst count bytes upper limit
1611 CONFIG_TPM_ATMEL_TWI
1612 Support for Atmel TWI TPM device. Requires I2C support.
1615 Support for generic parallel port TPM devices. Only one device
1616 per system is supported at this time.
1618 CONFIG_TPM_TIS_BASE_ADDRESS
1619 Base address where the generic TPM device is mapped
1620 to. Contemporary x86 systems usually map it at
1624 Add tpm monitor functions.
1625 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1626 provides monitor access to authorized functions.
1629 Define this to enable the TPM support library which provides
1630 functional interfaces to some TPM commands.
1631 Requires support for a TPM device.
1633 CONFIG_TPM_AUTH_SESSIONS
1634 Define this to enable authorized functions in the TPM library.
1635 Requires CONFIG_TPM and CONFIG_SHA1.
1638 At the moment only the UHCI host controller is
1639 supported (PIP405, MIP405, MPC5200); define
1640 CONFIG_USB_UHCI to enable it.
1641 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1642 and define CONFIG_USB_STORAGE to enable the USB
1645 Supported are USB Keyboards and USB Floppy drives
1647 MPC5200 USB requires additional defines:
1649 for 528 MHz Clock: 0x0001bbbb
1653 for differential drivers: 0x00001000
1654 for single ended drivers: 0x00005000
1655 for differential drivers on PSC3: 0x00000100
1656 for single ended drivers on PSC3: 0x00004100
1657 CONFIG_SYS_USB_EVENT_POLL
1658 May be defined to allow interrupt polling
1659 instead of using asynchronous interrupts
1661 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1662 txfilltuning field in the EHCI controller on reset.
1664 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1665 HW module registers.
1668 Define the below if you wish to use the USB console.
1669 Once firmware is rebuilt from a serial console issue the
1670 command "setenv stdin usbtty; setenv stdout usbtty" and
1671 attach your USB cable. The Unix command "dmesg" should print
1672 it has found a new device. The environment variable usbtty
1673 can be set to gserial or cdc_acm to enable your device to
1674 appear to a USB host as a Linux gserial device or a
1675 Common Device Class Abstract Control Model serial device.
1676 If you select usbtty = gserial you should be able to enumerate
1678 # modprobe usbserial vendor=0xVendorID product=0xProductID
1679 else if using cdc_acm, simply setting the environment
1680 variable usbtty to be cdc_acm should suffice. The following
1681 might be defined in YourBoardName.h
1684 Define this to build a UDC device
1687 Define this to have a tty type of device available to
1688 talk to the UDC device
1691 Define this to enable the high speed support for usb
1692 device and usbtty. If this feature is enabled, a routine
1693 int is_usbd_high_speed(void)
1694 also needs to be defined by the driver to dynamically poll
1695 whether the enumeration has succeded at high speed or full
1698 CONFIG_SYS_CONSOLE_IS_IN_ENV
1699 Define this if you want stdin, stdout &/or stderr to
1703 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1704 Derive USB clock from external clock "blah"
1705 - CONFIG_SYS_USB_EXTC_CLK 0x02
1707 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1708 Derive USB clock from brgclk
1709 - CONFIG_SYS_USB_BRG_CLK 0x04
1711 If you have a USB-IF assigned VendorID then you may wish to
1712 define your own vendor specific values either in BoardName.h
1713 or directly in usbd_vendor_info.h. If you don't define
1714 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1715 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1716 should pretend to be a Linux device to it's target host.
1718 CONFIG_USBD_MANUFACTURER
1719 Define this string as the name of your company for
1720 - CONFIG_USBD_MANUFACTURER "my company"
1722 CONFIG_USBD_PRODUCT_NAME
1723 Define this string as the name of your product
1724 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1726 CONFIG_USBD_VENDORID
1727 Define this as your assigned Vendor ID from the USB
1728 Implementors Forum. This *must* be a genuine Vendor ID
1729 to avoid polluting the USB namespace.
1730 - CONFIG_USBD_VENDORID 0xFFFF
1732 CONFIG_USBD_PRODUCTID
1733 Define this as the unique Product ID
1735 - CONFIG_USBD_PRODUCTID 0xFFFF
1737 - ULPI Layer Support:
1738 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1739 the generic ULPI layer. The generic layer accesses the ULPI PHY
1740 via the platform viewport, so you need both the genric layer and
1741 the viewport enabled. Currently only Chipidea/ARC based
1742 viewport is supported.
1743 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1744 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1745 If your ULPI phy needs a different reference clock than the
1746 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1747 the appropriate value in Hz.
1750 The MMC controller on the Intel PXA is supported. To
1751 enable this define CONFIG_MMC. The MMC can be
1752 accessed from the boot prompt by mapping the device
1753 to physical memory similar to flash. Command line is
1754 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1755 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1758 Support for Renesas on-chip MMCIF controller
1760 CONFIG_SH_MMCIF_ADDR
1761 Define the base address of MMCIF registers
1764 Define the clock frequency for MMCIF
1767 Enable the generic MMC driver
1769 CONFIG_SUPPORT_EMMC_BOOT
1770 Enable some additional features of the eMMC boot partitions.
1772 CONFIG_SUPPORT_EMMC_RPMB
1773 Enable the commands for reading, writing and programming the
1774 key for the Replay Protection Memory Block partition in eMMC.
1776 - USB Device Firmware Update (DFU) class support:
1778 This enables the USB portion of the DFU USB class
1781 This enables the command "dfu" which is used to have
1782 U-Boot create a DFU class device via USB. This command
1783 requires that the "dfu_alt_info" environment variable be
1784 set and define the alt settings to expose to the host.
1787 This enables support for exposing (e)MMC devices via DFU.
1790 This enables support for exposing NAND devices via DFU.
1793 This enables support for exposing RAM via DFU.
1794 Note: DFU spec refer to non-volatile memory usage, but
1795 allow usages beyond the scope of spec - here RAM usage,
1796 one that would help mostly the developer.
1798 CONFIG_SYS_DFU_DATA_BUF_SIZE
1799 Dfu transfer uses a buffer before writing data to the
1800 raw storage device. Make the size (in bytes) of this buffer
1801 configurable. The size of this buffer is also configurable
1802 through the "dfu_bufsiz" environment variable.
1804 CONFIG_SYS_DFU_MAX_FILE_SIZE
1805 When updating files rather than the raw storage device,
1806 we use a static buffer to copy the file into and then write
1807 the buffer once we've been given the whole file. Define
1808 this to the maximum filesize (in bytes) for the buffer.
1809 Default is 4 MiB if undefined.
1811 DFU_DEFAULT_POLL_TIMEOUT
1812 Poll timeout [ms], is the timeout a device can send to the
1813 host. The host must wait for this timeout before sending
1814 a subsequent DFU_GET_STATUS request to the device.
1816 DFU_MANIFEST_POLL_TIMEOUT
1817 Poll timeout [ms], which the device sends to the host when
1818 entering dfuMANIFEST state. Host waits this timeout, before
1819 sending again an USB request to the device.
1821 - USB Device Android Fastboot support:
1823 This enables the command "fastboot" which enables the Android
1824 fastboot mode for the platform's USB device. Fastboot is a USB
1825 protocol for downloading images, flashing and device control
1826 used on Android devices.
1827 See doc/README.android-fastboot for more information.
1829 CONFIG_ANDROID_BOOT_IMAGE
1830 This enables support for booting images which use the Android
1831 image format header.
1833 CONFIG_USB_FASTBOOT_BUF_ADDR
1834 The fastboot protocol requires a large memory buffer for
1835 downloads. Define this to the starting RAM address to use for
1838 CONFIG_USB_FASTBOOT_BUF_SIZE
1839 The fastboot protocol requires a large memory buffer for
1840 downloads. This buffer should be as large as possible for a
1841 platform. Define this to the size available RAM for fastboot.
1843 CONFIG_FASTBOOT_FLASH
1844 The fastboot protocol includes a "flash" command for writing
1845 the downloaded image to a non-volatile storage device. Define
1846 this to enable the "fastboot flash" command.
1848 CONFIG_FASTBOOT_FLASH_MMC_DEV
1849 The fastboot "flash" command requires additional information
1850 regarding the non-volatile storage device. Define this to
1851 the eMMC device that fastboot should use to store the image.
1853 CONFIG_FASTBOOT_GPT_NAME
1854 The fastboot "flash" command supports writing the downloaded
1855 image to the Protective MBR and the Primary GUID Partition
1856 Table. (Additionally, this downloaded image is post-processed
1857 to generate and write the Backup GUID Partition Table.)
1858 This occurs when the specified "partition name" on the
1859 "fastboot flash" command line matches this value.
1860 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1862 - Journaling Flash filesystem support:
1863 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1864 CONFIG_JFFS2_NAND_DEV
1865 Define these for a default partition on a NAND device
1867 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1868 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1869 Define these for a default partition on a NOR device
1871 CONFIG_SYS_JFFS_CUSTOM_PART
1872 Define this to create an own partition. You have to provide a
1873 function struct part_info* jffs2_part_info(int part_num)
1875 If you define only one JFFS2 partition you may also want to
1876 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1877 to disable the command chpart. This is the default when you
1878 have not defined a custom partition
1880 - FAT(File Allocation Table) filesystem write function support:
1883 Define this to enable support for saving memory data as a
1884 file in FAT formatted partition.
1886 This will also enable the command "fatwrite" enabling the
1887 user to write files to FAT.
1889 CBFS (Coreboot Filesystem) support
1892 Define this to enable support for reading from a Coreboot
1893 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1896 - FAT(File Allocation Table) filesystem cluster size:
1897 CONFIG_FS_FAT_MAX_CLUSTSIZE
1899 Define the max cluster size for fat operations else
1900 a default value of 65536 will be defined.
1905 Define this to enable standard (PC-Style) keyboard
1909 Standard PC keyboard driver with US (is default) and
1910 GERMAN key layout (switch via environment 'keymap=de') support.
1911 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1912 for cfb_console. Supports cursor blinking.
1915 Enables a Chrome OS keyboard using the CROS_EC interface.
1916 This uses CROS_EC to communicate with a second microcontroller
1917 which provides key scans on request.
1922 Define this to enable video support (for output to
1925 CONFIG_VIDEO_CT69000
1927 Enable Chips & Technologies 69000 Video chip
1929 CONFIG_VIDEO_SMI_LYNXEM
1930 Enable Silicon Motion SMI 712/710/810 Video chip. The
1931 video output is selected via environment 'videoout'
1932 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1935 For the CT69000 and SMI_LYNXEM drivers, videomode is
1936 selected via environment 'videomode'. Two different ways
1938 - "videomode=num" 'num' is a standard LiLo mode numbers.
1939 Following standard modes are supported (* is default):
1941 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1942 -------------+---------------------------------------------
1943 8 bits | 0x301* 0x303 0x305 0x161 0x307
1944 15 bits | 0x310 0x313 0x316 0x162 0x319
1945 16 bits | 0x311 0x314 0x317 0x163 0x31A
1946 24 bits | 0x312 0x315 0x318 ? 0x31B
1947 -------------+---------------------------------------------
1948 (i.e. setenv videomode 317; saveenv; reset;)
1950 - "videomode=bootargs" all the video parameters are parsed
1951 from the bootargs. (See drivers/video/videomodes.c)
1954 CONFIG_VIDEO_SED13806
1955 Enable Epson SED13806 driver. This driver supports 8bpp
1956 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1957 or CONFIG_VIDEO_SED13806_16BPP
1960 Enable the Freescale DIU video driver. Reference boards for
1961 SOCs that have a DIU should define this macro to enable DIU
1962 support, and should also define these other macros:
1968 CONFIG_VIDEO_SW_CURSOR
1969 CONFIG_VGA_AS_SINGLE_DEVICE
1971 CONFIG_VIDEO_BMP_LOGO
1973 The DIU driver will look for the 'video-mode' environment
1974 variable, and if defined, enable the DIU as a console during
1975 boot. See the documentation file README.video for a
1976 description of this variable.
1980 Enable the VGA video / BIOS for x86. The alternative if you
1981 are using coreboot is to use the coreboot frame buffer
1988 Define this to enable a custom keyboard support.
1989 This simply calls drv_keyboard_init() which must be
1990 defined in your board-specific files.
1991 The only board using this so far is RBC823.
1993 - LCD Support: CONFIG_LCD
1995 Define this to enable LCD support (for output to LCD
1996 display); also select one of the supported displays
1997 by defining one of these:
2001 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2003 CONFIG_NEC_NL6448AC33:
2005 NEC NL6448AC33-18. Active, color, single scan.
2007 CONFIG_NEC_NL6448BC20
2009 NEC NL6448BC20-08. 6.5", 640x480.
2010 Active, color, single scan.
2012 CONFIG_NEC_NL6448BC33_54
2014 NEC NL6448BC33-54. 10.4", 640x480.
2015 Active, color, single scan.
2019 Sharp 320x240. Active, color, single scan.
2020 It isn't 16x9, and I am not sure what it is.
2022 CONFIG_SHARP_LQ64D341
2024 Sharp LQ64D341 display, 640x480.
2025 Active, color, single scan.
2029 HLD1045 display, 640x480.
2030 Active, color, single scan.
2034 Optrex CBL50840-2 NF-FW 99 22 M5
2036 Hitachi LMG6912RPFC-00T
2040 320x240. Black & white.
2042 Normally display is black on white background; define
2043 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2045 CONFIG_LCD_ALIGNMENT
2047 Normally the LCD is page-aligned (typically 4KB). If this is
2048 defined then the LCD will be aligned to this value instead.
2049 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2050 here, since it is cheaper to change data cache settings on
2051 a per-section basis.
2053 CONFIG_CONSOLE_SCROLL_LINES
2055 When the console need to be scrolled, this is the number of
2056 lines to scroll by. It defaults to 1. Increasing this makes
2057 the console jump but can help speed up operation when scrolling
2062 Sometimes, for example if the display is mounted in portrait
2063 mode or even if it's mounted landscape but rotated by 180degree,
2064 we need to rotate our content of the display relative to the
2065 framebuffer, so that user can read the messages which are
2067 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2068 initialized with a given rotation from "vl_rot" out of
2069 "vidinfo_t" which is provided by the board specific code.
2070 The value for vl_rot is coded as following (matching to
2071 fbcon=rotate:<n> linux-kernel commandline):
2072 0 = no rotation respectively 0 degree
2073 1 = 90 degree rotation
2074 2 = 180 degree rotation
2075 3 = 270 degree rotation
2077 If CONFIG_LCD_ROTATION is not defined, the console will be
2078 initialized with 0degree rotation.
2082 Support drawing of RLE8-compressed bitmaps on the LCD.
2086 Enables an 'i2c edid' command which can read EDID
2087 information over I2C from an attached LCD display.
2089 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2091 If this option is set, the environment is checked for
2092 a variable "splashimage". If found, the usual display
2093 of logo, copyright and system information on the LCD
2094 is suppressed and the BMP image at the address
2095 specified in "splashimage" is loaded instead. The
2096 console is redirected to the "nulldev", too. This
2097 allows for a "silent" boot where a splash screen is
2098 loaded very quickly after power-on.
2100 CONFIG_SPLASHIMAGE_GUARD
2102 If this option is set, then U-Boot will prevent the environment
2103 variable "splashimage" from being set to a problematic address
2104 (see README.displaying-bmps).
2105 This option is useful for targets where, due to alignment
2106 restrictions, an improperly aligned BMP image will cause a data
2107 abort. If you think you will not have problems with unaligned
2108 accesses (for example because your toolchain prevents them)
2109 there is no need to set this option.
2111 CONFIG_SPLASH_SCREEN_ALIGN
2113 If this option is set the splash image can be freely positioned
2114 on the screen. Environment variable "splashpos" specifies the
2115 position as "x,y". If a positive number is given it is used as
2116 number of pixel from left/top. If a negative number is given it
2117 is used as number of pixel from right/bottom. You can also
2118 specify 'm' for centering the image.
2121 setenv splashpos m,m
2122 => image at center of screen
2124 setenv splashpos 30,20
2125 => image at x = 30 and y = 20
2127 setenv splashpos -10,m
2128 => vertically centered image
2129 at x = dspWidth - bmpWidth - 9
2131 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2133 If this option is set, additionally to standard BMP
2134 images, gzipped BMP images can be displayed via the
2135 splashscreen support or the bmp command.
2137 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2139 If this option is set, 8-bit RLE compressed BMP images
2140 can be displayed via the splashscreen support or the
2143 - Do compressing for memory range:
2146 If this option is set, it would use zlib deflate method
2147 to compress the specified memory at its best effort.
2149 - Compression support:
2152 Enabled by default to support gzip compressed images.
2156 If this option is set, support for bzip2 compressed
2157 images is included. If not, only uncompressed and gzip
2158 compressed images are supported.
2160 NOTE: the bzip2 algorithm requires a lot of RAM, so
2161 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2166 If this option is set, support for lzma compressed
2169 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2170 requires an amount of dynamic memory that is given by the
2173 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2175 Where lc and lp stand for, respectively, Literal context bits
2176 and Literal pos bits.
2178 This value is upper-bounded by 14MB in the worst case. Anyway,
2179 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2180 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2181 a very small buffer.
2183 Use the lzmainfo tool to determinate the lc and lp values and
2184 then calculate the amount of needed dynamic memory (ensuring
2185 the appropriate CONFIG_SYS_MALLOC_LEN value).
2189 If this option is set, support for LZO compressed images
2195 The address of PHY on MII bus.
2197 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2199 The clock frequency of the MII bus
2203 If this option is set, support for speed/duplex
2204 detection of gigabit PHY is included.
2206 CONFIG_PHY_RESET_DELAY
2208 Some PHY like Intel LXT971A need extra delay after
2209 reset before any MII register access is possible.
2210 For such PHY, set this option to the usec delay
2211 required. (minimum 300usec for LXT971A)
2213 CONFIG_PHY_CMD_DELAY (ppc4xx)
2215 Some PHY like Intel LXT971A need extra delay after
2216 command issued before MII status register can be read
2226 Define a default value for Ethernet address to use
2227 for the respective Ethernet interface, in case this
2228 is not determined automatically.
2233 Define a default value for the IP address to use for
2234 the default Ethernet interface, in case this is not
2235 determined through e.g. bootp.
2236 (Environment variable "ipaddr")
2238 - Server IP address:
2241 Defines a default value for the IP address of a TFTP
2242 server to contact when using the "tftboot" command.
2243 (Environment variable "serverip")
2245 CONFIG_KEEP_SERVERADDR
2247 Keeps the server's MAC address, in the env 'serveraddr'
2248 for passing to bootargs (like Linux's netconsole option)
2250 - Gateway IP address:
2253 Defines a default value for the IP address of the
2254 default router where packets to other networks are
2256 (Environment variable "gatewayip")
2261 Defines a default value for the subnet mask (or
2262 routing prefix) which is used to determine if an IP
2263 address belongs to the local subnet or needs to be
2264 forwarded through a router.
2265 (Environment variable "netmask")
2267 - Multicast TFTP Mode:
2270 Defines whether you want to support multicast TFTP as per
2271 rfc-2090; for example to work with atftp. Lets lots of targets
2272 tftp down the same boot image concurrently. Note: the Ethernet
2273 driver in use must provide a function: mcast() to join/leave a
2276 - BOOTP Recovery Mode:
2277 CONFIG_BOOTP_RANDOM_DELAY
2279 If you have many targets in a network that try to
2280 boot using BOOTP, you may want to avoid that all
2281 systems send out BOOTP requests at precisely the same
2282 moment (which would happen for instance at recovery
2283 from a power failure, when all systems will try to
2284 boot, thus flooding the BOOTP server. Defining
2285 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2286 inserted before sending out BOOTP requests. The
2287 following delays are inserted then:
2289 1st BOOTP request: delay 0 ... 1 sec
2290 2nd BOOTP request: delay 0 ... 2 sec
2291 3rd BOOTP request: delay 0 ... 4 sec
2293 BOOTP requests: delay 0 ... 8 sec
2295 CONFIG_BOOTP_ID_CACHE_SIZE
2297 BOOTP packets are uniquely identified using a 32-bit ID. The
2298 server will copy the ID from client requests to responses and
2299 U-Boot will use this to determine if it is the destination of
2300 an incoming response. Some servers will check that addresses
2301 aren't in use before handing them out (usually using an ARP
2302 ping) and therefore take up to a few hundred milliseconds to
2303 respond. Network congestion may also influence the time it
2304 takes for a response to make it back to the client. If that
2305 time is too long, U-Boot will retransmit requests. In order
2306 to allow earlier responses to still be accepted after these
2307 retransmissions, U-Boot's BOOTP client keeps a small cache of
2308 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2309 cache. The default is to keep IDs for up to four outstanding
2310 requests. Increasing this will allow U-Boot to accept offers
2311 from a BOOTP client in networks with unusually high latency.
2313 - BOOTP Random transaction ID:
2314 CONFIG_BOOTP_RANDOM_ID
2316 The standard algorithm to generate a DHCP/BOOTP transaction ID
2317 by using the MAC address and the current time stamp may not
2318 quite unlikely produce duplicate transaction IDs from different
2319 clients in the same network. This option creates a transaction
2320 ID using the rand() function. Provided that the RNG has been
2321 seeded well, this should guarantee unique transaction IDs
2324 - DHCP Advanced Options:
2325 You can fine tune the DHCP functionality by defining
2326 CONFIG_BOOTP_* symbols:
2328 CONFIG_BOOTP_SUBNETMASK
2329 CONFIG_BOOTP_GATEWAY
2330 CONFIG_BOOTP_HOSTNAME
2331 CONFIG_BOOTP_NISDOMAIN
2332 CONFIG_BOOTP_BOOTPATH
2333 CONFIG_BOOTP_BOOTFILESIZE
2336 CONFIG_BOOTP_SEND_HOSTNAME
2337 CONFIG_BOOTP_NTPSERVER
2338 CONFIG_BOOTP_TIMEOFFSET
2339 CONFIG_BOOTP_VENDOREX
2340 CONFIG_BOOTP_MAY_FAIL
2342 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2343 environment variable, not the BOOTP server.
2345 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2346 after the configured retry count, the call will fail
2347 instead of starting over. This can be used to fail over
2348 to Link-local IP address configuration if the DHCP server
2351 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2352 serverip from a DHCP server, it is possible that more
2353 than one DNS serverip is offered to the client.
2354 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2355 serverip will be stored in the additional environment
2356 variable "dnsip2". The first DNS serverip is always
2357 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2360 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2361 to do a dynamic update of a DNS server. To do this, they
2362 need the hostname of the DHCP requester.
2363 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2364 of the "hostname" environment variable is passed as
2365 option 12 to the DHCP server.
2367 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2369 A 32bit value in microseconds for a delay between
2370 receiving a "DHCP Offer" and sending the "DHCP Request".
2371 This fixes a problem with certain DHCP servers that don't
2372 respond 100% of the time to a "DHCP request". E.g. On an
2373 AT91RM9200 processor running at 180MHz, this delay needed
2374 to be *at least* 15,000 usec before a Windows Server 2003
2375 DHCP server would reply 100% of the time. I recommend at
2376 least 50,000 usec to be safe. The alternative is to hope
2377 that one of the retries will be successful but note that
2378 the DHCP timeout and retry process takes a longer than
2381 - Link-local IP address negotiation:
2382 Negotiate with other link-local clients on the local network
2383 for an address that doesn't require explicit configuration.
2384 This is especially useful if a DHCP server cannot be guaranteed
2385 to exist in all environments that the device must operate.
2387 See doc/README.link-local for more information.
2390 CONFIG_CDP_DEVICE_ID
2392 The device id used in CDP trigger frames.
2394 CONFIG_CDP_DEVICE_ID_PREFIX
2396 A two character string which is prefixed to the MAC address
2401 A printf format string which contains the ascii name of
2402 the port. Normally is set to "eth%d" which sets
2403 eth0 for the first Ethernet, eth1 for the second etc.
2405 CONFIG_CDP_CAPABILITIES
2407 A 32bit integer which indicates the device capabilities;
2408 0x00000010 for a normal host which does not forwards.
2412 An ascii string containing the version of the software.
2416 An ascii string containing the name of the platform.
2420 A 32bit integer sent on the trigger.
2422 CONFIG_CDP_POWER_CONSUMPTION
2424 A 16bit integer containing the power consumption of the
2425 device in .1 of milliwatts.
2427 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2429 A byte containing the id of the VLAN.
2431 - Status LED: CONFIG_STATUS_LED
2433 Several configurations allow to display the current
2434 status using a LED. For instance, the LED will blink
2435 fast while running U-Boot code, stop blinking as
2436 soon as a reply to a BOOTP request was received, and
2437 start blinking slow once the Linux kernel is running
2438 (supported by a status LED driver in the Linux
2439 kernel). Defining CONFIG_STATUS_LED enables this
2445 The status LED can be connected to a GPIO pin.
2446 In such cases, the gpio_led driver can be used as a
2447 status LED backend implementation. Define CONFIG_GPIO_LED
2448 to include the gpio_led driver in the U-Boot binary.
2450 CONFIG_GPIO_LED_INVERTED_TABLE
2451 Some GPIO connected LEDs may have inverted polarity in which
2452 case the GPIO high value corresponds to LED off state and
2453 GPIO low value corresponds to LED on state.
2454 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2455 with a list of GPIO LEDs that have inverted polarity.
2457 - CAN Support: CONFIG_CAN_DRIVER
2459 Defining CONFIG_CAN_DRIVER enables CAN driver support
2460 on those systems that support this (optional)
2461 feature, like the TQM8xxL modules.
2463 - I2C Support: CONFIG_SYS_I2C
2465 This enable the NEW i2c subsystem, and will allow you to use
2466 i2c commands at the u-boot command line (as long as you set
2467 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2468 based realtime clock chips or other i2c devices. See
2469 common/cmd_i2c.c for a description of the command line
2472 ported i2c driver to the new framework:
2473 - drivers/i2c/soft_i2c.c:
2474 - activate first bus with CONFIG_SYS_I2C_SOFT define
2475 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2476 for defining speed and slave address
2477 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2478 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2479 for defining speed and slave address
2480 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2481 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2482 for defining speed and slave address
2483 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2484 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2485 for defining speed and slave address
2487 - drivers/i2c/fsl_i2c.c:
2488 - activate i2c driver with CONFIG_SYS_I2C_FSL
2489 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2490 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2491 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2493 - If your board supports a second fsl i2c bus, define
2494 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2495 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2496 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2499 - drivers/i2c/tegra_i2c.c:
2500 - activate this driver with CONFIG_SYS_I2C_TEGRA
2501 - This driver adds 4 i2c buses with a fix speed from
2502 100000 and the slave addr 0!
2504 - drivers/i2c/ppc4xx_i2c.c
2505 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2506 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2507 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2509 - drivers/i2c/i2c_mxc.c
2510 - activate this driver with CONFIG_SYS_I2C_MXC
2511 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2512 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2513 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2514 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2515 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2516 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2517 If those defines are not set, default value is 100000
2518 for speed, and 0 for slave.
2520 - drivers/i2c/rcar_i2c.c:
2521 - activate this driver with CONFIG_SYS_I2C_RCAR
2522 - This driver adds 4 i2c buses
2524 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2525 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2526 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2527 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2528 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2529 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2530 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2531 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2532 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2534 - drivers/i2c/sh_i2c.c:
2535 - activate this driver with CONFIG_SYS_I2C_SH
2536 - This driver adds from 2 to 5 i2c buses
2538 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2539 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2540 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2541 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2542 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2543 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2544 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2545 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2546 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2547 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2548 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2549 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2550 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2552 - drivers/i2c/omap24xx_i2c.c
2553 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2554 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2555 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2556 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2557 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2558 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2559 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2560 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2561 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2562 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2563 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2565 - drivers/i2c/zynq_i2c.c
2566 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2567 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2568 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2570 - drivers/i2c/s3c24x0_i2c.c:
2571 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2572 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2573 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2574 with a fix speed from 100000 and the slave addr 0!
2576 - drivers/i2c/ihs_i2c.c
2577 - activate this driver with CONFIG_SYS_I2C_IHS
2578 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2579 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2580 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2581 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2582 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2583 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2584 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2585 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2586 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2587 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2588 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2589 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2593 CONFIG_SYS_NUM_I2C_BUSES
2594 Hold the number of i2c buses you want to use. If you
2595 don't use/have i2c muxes on your i2c bus, this
2596 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2599 CONFIG_SYS_I2C_DIRECT_BUS
2600 define this, if you don't use i2c muxes on your hardware.
2601 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2604 CONFIG_SYS_I2C_MAX_HOPS
2605 define how many muxes are maximal consecutively connected
2606 on one i2c bus. If you not use i2c muxes, omit this
2609 CONFIG_SYS_I2C_BUSES
2610 hold a list of buses you want to use, only used if
2611 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2612 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2613 CONFIG_SYS_NUM_I2C_BUSES = 9:
2615 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2616 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2617 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2618 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2619 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2620 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2621 {1, {I2C_NULL_HOP}}, \
2622 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2623 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2627 bus 0 on adapter 0 without a mux
2628 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2629 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2630 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2631 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2632 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2633 bus 6 on adapter 1 without a mux
2634 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2635 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2637 If you do not have i2c muxes on your board, omit this define.
2639 - Legacy I2C Support: CONFIG_HARD_I2C
2641 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2642 provides the following compelling advantages:
2644 - more than one i2c adapter is usable
2645 - approved multibus support
2646 - better i2c mux support
2648 ** Please consider updating your I2C driver now. **
2650 These enable legacy I2C serial bus commands. Defining
2651 CONFIG_HARD_I2C will include the appropriate I2C driver
2652 for the selected CPU.
2654 This will allow you to use i2c commands at the u-boot
2655 command line (as long as you set CONFIG_CMD_I2C in
2656 CONFIG_COMMANDS) and communicate with i2c based realtime
2657 clock chips. See common/cmd_i2c.c for a description of the
2658 command line interface.
2660 CONFIG_HARD_I2C selects a hardware I2C controller.
2662 There are several other quantities that must also be
2663 defined when you define CONFIG_HARD_I2C.
2665 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2666 to be the frequency (in Hz) at which you wish your i2c bus
2667 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2668 the CPU's i2c node address).
2670 Now, the u-boot i2c code for the mpc8xx
2671 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2672 and so its address should therefore be cleared to 0 (See,
2673 eg, MPC823e User's Manual p.16-473). So, set
2674 CONFIG_SYS_I2C_SLAVE to 0.
2676 CONFIG_SYS_I2C_INIT_MPC5XXX
2678 When a board is reset during an i2c bus transfer
2679 chips might think that the current transfer is still
2680 in progress. Reset the slave devices by sending start
2681 commands until the slave device responds.
2683 That's all that's required for CONFIG_HARD_I2C.
2685 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2686 then the following macros need to be defined (examples are
2687 from include/configs/lwmon.h):
2691 (Optional). Any commands necessary to enable the I2C
2692 controller or configure ports.
2694 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2698 (Only for MPC8260 CPU). The I/O port to use (the code
2699 assumes both bits are on the same port). Valid values
2700 are 0..3 for ports A..D.
2704 The code necessary to make the I2C data line active
2705 (driven). If the data line is open collector, this
2708 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2712 The code necessary to make the I2C data line tri-stated
2713 (inactive). If the data line is open collector, this
2716 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2720 Code that returns true if the I2C data line is high,
2723 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2727 If <bit> is true, sets the I2C data line high. If it
2728 is false, it clears it (low).
2730 eg: #define I2C_SDA(bit) \
2731 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2732 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2736 If <bit> is true, sets the I2C clock line high. If it
2737 is false, it clears it (low).
2739 eg: #define I2C_SCL(bit) \
2740 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2741 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2745 This delay is invoked four times per clock cycle so this
2746 controls the rate of data transfer. The data rate thus
2747 is 1 / (I2C_DELAY * 4). Often defined to be something
2750 #define I2C_DELAY udelay(2)
2752 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2754 If your arch supports the generic GPIO framework (asm/gpio.h),
2755 then you may alternatively define the two GPIOs that are to be
2756 used as SCL / SDA. Any of the previous I2C_xxx macros will
2757 have GPIO-based defaults assigned to them as appropriate.
2759 You should define these to the GPIO value as given directly to
2760 the generic GPIO functions.
2762 CONFIG_SYS_I2C_INIT_BOARD
2764 When a board is reset during an i2c bus transfer
2765 chips might think that the current transfer is still
2766 in progress. On some boards it is possible to access
2767 the i2c SCLK line directly, either by using the
2768 processor pin as a GPIO or by having a second pin
2769 connected to the bus. If this option is defined a
2770 custom i2c_init_board() routine in boards/xxx/board.c
2771 is run early in the boot sequence.
2773 CONFIG_SYS_I2C_BOARD_LATE_INIT
2775 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2776 defined a custom i2c_board_late_init() routine in
2777 boards/xxx/board.c is run AFTER the operations in i2c_init()
2778 is completed. This callpoint can be used to unreset i2c bus
2779 using CPU i2c controller register accesses for CPUs whose i2c
2780 controller provide such a method. It is called at the end of
2781 i2c_init() to allow i2c_init operations to setup the i2c bus
2782 controller on the CPU (e.g. setting bus speed & slave address).
2784 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2786 This option enables configuration of bi_iic_fast[] flags
2787 in u-boot bd_info structure based on u-boot environment
2788 variable "i2cfast". (see also i2cfast)
2790 CONFIG_I2C_MULTI_BUS
2792 This option allows the use of multiple I2C buses, each of which
2793 must have a controller. At any point in time, only one bus is
2794 active. To switch to a different bus, use the 'i2c dev' command.
2795 Note that bus numbering is zero-based.
2797 CONFIG_SYS_I2C_NOPROBES
2799 This option specifies a list of I2C devices that will be skipped
2800 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2801 is set, specify a list of bus-device pairs. Otherwise, specify
2802 a 1D array of device addresses
2805 #undef CONFIG_I2C_MULTI_BUS
2806 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2808 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2810 #define CONFIG_I2C_MULTI_BUS
2811 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2813 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2815 CONFIG_SYS_SPD_BUS_NUM
2817 If defined, then this indicates the I2C bus number for DDR SPD.
2818 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2820 CONFIG_SYS_RTC_BUS_NUM
2822 If defined, then this indicates the I2C bus number for the RTC.
2823 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2825 CONFIG_SYS_DTT_BUS_NUM
2827 If defined, then this indicates the I2C bus number for the DTT.
2828 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2830 CONFIG_SYS_I2C_DTT_ADDR:
2832 If defined, specifies the I2C address of the DTT device.
2833 If not defined, then U-Boot uses predefined value for
2834 specified DTT device.
2836 CONFIG_SOFT_I2C_READ_REPEATED_START
2838 defining this will force the i2c_read() function in
2839 the soft_i2c driver to perform an I2C repeated start
2840 between writing the address pointer and reading the
2841 data. If this define is omitted the default behaviour
2842 of doing a stop-start sequence will be used. Most I2C
2843 devices can use either method, but some require one or
2846 - SPI Support: CONFIG_SPI
2848 Enables SPI driver (so far only tested with
2849 SPI EEPROM, also an instance works with Crystal A/D and
2850 D/As on the SACSng board)
2854 Enables the driver for SPI controller on SuperH. Currently
2855 only SH7757 is supported.
2859 Enables extended (16-bit) SPI EEPROM addressing.
2860 (symmetrical to CONFIG_I2C_X)
2864 Enables a software (bit-bang) SPI driver rather than
2865 using hardware support. This is a general purpose
2866 driver that only requires three general I/O port pins
2867 (two outputs, one input) to function. If this is
2868 defined, the board configuration must define several
2869 SPI configuration items (port pins to use, etc). For
2870 an example, see include/configs/sacsng.h.
2874 Enables a hardware SPI driver for general-purpose reads
2875 and writes. As with CONFIG_SOFT_SPI, the board configuration
2876 must define a list of chip-select function pointers.
2877 Currently supported on some MPC8xxx processors. For an
2878 example, see include/configs/mpc8349emds.h.
2882 Enables the driver for the SPI controllers on i.MX and MXC
2883 SoCs. Currently i.MX31/35/51 are supported.
2885 CONFIG_SYS_SPI_MXC_WAIT
2886 Timeout for waiting until spi transfer completed.
2887 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2889 - FPGA Support: CONFIG_FPGA
2891 Enables FPGA subsystem.
2893 CONFIG_FPGA_<vendor>
2895 Enables support for specific chip vendors.
2898 CONFIG_FPGA_<family>
2900 Enables support for FPGA family.
2901 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2905 Specify the number of FPGA devices to support.
2907 CONFIG_CMD_FPGA_LOADMK
2909 Enable support for fpga loadmk command
2911 CONFIG_CMD_FPGA_LOADP
2913 Enable support for fpga loadp command - load partial bitstream
2915 CONFIG_CMD_FPGA_LOADBP
2917 Enable support for fpga loadbp command - load partial bitstream
2920 CONFIG_SYS_FPGA_PROG_FEEDBACK
2922 Enable printing of hash marks during FPGA configuration.
2924 CONFIG_SYS_FPGA_CHECK_BUSY
2926 Enable checks on FPGA configuration interface busy
2927 status by the configuration function. This option
2928 will require a board or device specific function to
2933 If defined, a function that provides delays in the FPGA
2934 configuration driver.
2936 CONFIG_SYS_FPGA_CHECK_CTRLC
2937 Allow Control-C to interrupt FPGA configuration
2939 CONFIG_SYS_FPGA_CHECK_ERROR
2941 Check for configuration errors during FPGA bitfile
2942 loading. For example, abort during Virtex II
2943 configuration if the INIT_B line goes low (which
2944 indicated a CRC error).
2946 CONFIG_SYS_FPGA_WAIT_INIT
2948 Maximum time to wait for the INIT_B line to de-assert
2949 after PROB_B has been de-asserted during a Virtex II
2950 FPGA configuration sequence. The default time is 500
2953 CONFIG_SYS_FPGA_WAIT_BUSY
2955 Maximum time to wait for BUSY to de-assert during
2956 Virtex II FPGA configuration. The default is 5 ms.
2958 CONFIG_SYS_FPGA_WAIT_CONFIG
2960 Time to wait after FPGA configuration. The default is
2963 - Configuration Management:
2966 Some SoCs need special image types (e.g. U-Boot binary
2967 with a special header) as build targets. By defining
2968 CONFIG_BUILD_TARGET in the SoC / board header, this
2969 special image will be automatically built upon calling
2974 If defined, this string will be added to the U-Boot
2975 version information (U_BOOT_VERSION)
2977 - Vendor Parameter Protection:
2979 U-Boot considers the values of the environment
2980 variables "serial#" (Board Serial Number) and
2981 "ethaddr" (Ethernet Address) to be parameters that
2982 are set once by the board vendor / manufacturer, and
2983 protects these variables from casual modification by
2984 the user. Once set, these variables are read-only,
2985 and write or delete attempts are rejected. You can
2986 change this behaviour:
2988 If CONFIG_ENV_OVERWRITE is #defined in your config
2989 file, the write protection for vendor parameters is
2990 completely disabled. Anybody can change or delete
2993 Alternatively, if you #define _both_ CONFIG_ETHADDR
2994 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2995 Ethernet address is installed in the environment,
2996 which can be changed exactly ONCE by the user. [The
2997 serial# is unaffected by this, i. e. it remains
3000 The same can be accomplished in a more flexible way
3001 for any variable by configuring the type of access
3002 to allow for those variables in the ".flags" variable
3003 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3008 Define this variable to enable the reservation of
3009 "protected RAM", i. e. RAM which is not overwritten
3010 by U-Boot. Define CONFIG_PRAM to hold the number of
3011 kB you want to reserve for pRAM. You can overwrite
3012 this default value by defining an environment
3013 variable "pram" to the number of kB you want to
3014 reserve. Note that the board info structure will
3015 still show the full amount of RAM. If pRAM is
3016 reserved, a new environment variable "mem" will
3017 automatically be defined to hold the amount of
3018 remaining RAM in a form that can be passed as boot
3019 argument to Linux, for instance like that:
3021 setenv bootargs ... mem=\${mem}
3024 This way you can tell Linux not to use this memory,
3025 either, which results in a memory region that will
3026 not be affected by reboots.
3028 *WARNING* If your board configuration uses automatic
3029 detection of the RAM size, you must make sure that
3030 this memory test is non-destructive. So far, the
3031 following board configurations are known to be
3034 IVMS8, IVML24, SPD8xx, TQM8xxL,
3035 HERMES, IP860, RPXlite, LWMON,
3038 - Access to physical memory region (> 4GB)
3039 Some basic support is provided for operations on memory not
3040 normally accessible to U-Boot - e.g. some architectures
3041 support access to more than 4GB of memory on 32-bit
3042 machines using physical address extension or similar.
3043 Define CONFIG_PHYSMEM to access this basic support, which
3044 currently only supports clearing the memory.
3049 Define this variable to stop the system in case of a
3050 fatal error, so that you have to reset it manually.
3051 This is probably NOT a good idea for an embedded
3052 system where you want the system to reboot
3053 automatically as fast as possible, but it may be
3054 useful during development since you can try to debug
3055 the conditions that lead to the situation.
3057 CONFIG_NET_RETRY_COUNT
3059 This variable defines the number of retries for
3060 network operations like ARP, RARP, TFTP, or BOOTP
3061 before giving up the operation. If not defined, a
3062 default value of 5 is used.
3066 Timeout waiting for an ARP reply in milliseconds.
3070 Timeout in milliseconds used in NFS protocol.
3071 If you encounter "ERROR: Cannot umount" in nfs command,
3072 try longer timeout such as
3073 #define CONFIG_NFS_TIMEOUT 10000UL
3075 - Command Interpreter:
3076 CONFIG_AUTO_COMPLETE
3078 Enable auto completion of commands using TAB.
3080 CONFIG_SYS_PROMPT_HUSH_PS2
3082 This defines the secondary prompt string, which is
3083 printed when the command interpreter needs more input
3084 to complete a command. Usually "> ".
3088 In the current implementation, the local variables
3089 space and global environment variables space are
3090 separated. Local variables are those you define by
3091 simply typing `name=value'. To access a local
3092 variable later on, you have write `$name' or
3093 `${name}'; to execute the contents of a variable
3094 directly type `$name' at the command prompt.
3096 Global environment variables are those you use
3097 setenv/printenv to work with. To run a command stored
3098 in such a variable, you need to use the run command,
3099 and you must not use the '$' sign to access them.
3101 To store commands and special characters in a
3102 variable, please use double quotation marks
3103 surrounding the whole text of the variable, instead
3104 of the backslashes before semicolons and special
3107 - Command Line Editing and History:
3108 CONFIG_CMDLINE_EDITING
3110 Enable editing and History functions for interactive
3111 command line input operations
3113 - Default Environment:
3114 CONFIG_EXTRA_ENV_SETTINGS
3116 Define this to contain any number of null terminated
3117 strings (variable = value pairs) that will be part of
3118 the default environment compiled into the boot image.
3120 For example, place something like this in your
3121 board's config file:
3123 #define CONFIG_EXTRA_ENV_SETTINGS \
3127 Warning: This method is based on knowledge about the
3128 internal format how the environment is stored by the
3129 U-Boot code. This is NOT an official, exported
3130 interface! Although it is unlikely that this format
3131 will change soon, there is no guarantee either.
3132 You better know what you are doing here.
3134 Note: overly (ab)use of the default environment is
3135 discouraged. Make sure to check other ways to preset
3136 the environment like the "source" command or the
3139 CONFIG_ENV_VARS_UBOOT_CONFIG
3141 Define this in order to add variables describing the
3142 U-Boot build configuration to the default environment.
3143 These will be named arch, cpu, board, vendor, and soc.
3145 Enabling this option will cause the following to be defined:
3153 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3155 Define this in order to add variables describing certain
3156 run-time determined information about the hardware to the
3157 environment. These will be named board_name, board_rev.
3159 CONFIG_DELAY_ENVIRONMENT
3161 Normally the environment is loaded when the board is
3162 initialised so that it is available to U-Boot. This inhibits
3163 that so that the environment is not available until
3164 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3165 this is instead controlled by the value of
3166 /config/load-environment.
3168 - DataFlash Support:
3169 CONFIG_HAS_DATAFLASH
3171 Defining this option enables DataFlash features and
3172 allows to read/write in Dataflash via the standard
3175 - Serial Flash support
3178 Defining this option enables SPI flash commands
3179 'sf probe/read/write/erase/update'.
3181 Usage requires an initial 'probe' to define the serial
3182 flash parameters, followed by read/write/erase/update
3185 The following defaults may be provided by the platform
3186 to handle the common case when only a single serial
3187 flash is present on the system.
3189 CONFIG_SF_DEFAULT_BUS Bus identifier
3190 CONFIG_SF_DEFAULT_CS Chip-select
3191 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3192 CONFIG_SF_DEFAULT_SPEED in Hz
3196 Define this option to include a destructive SPI flash
3199 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3201 Define this option to use the Bank addr/Extended addr
3202 support on SPI flashes which has size > 16Mbytes.
3204 CONFIG_SF_DUAL_FLASH Dual flash memories
3206 Define this option to use dual flash support where two flash
3207 memories can be connected with a given cs line.
3208 Currently Xilinx Zynq qspi supports these type of connections.
3210 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3211 enable the W#/Vpp signal to disable writing to the status
3212 register on ST MICRON flashes like the N25Q128.
3213 The status register write enable/disable bit, combined with
3214 the W#/VPP signal provides hardware data protection for the
3215 device as follows: When the enable/disable bit is set to 1,
3216 and the W#/VPP signal is driven LOW, the status register
3217 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3218 operation will not execute. The only way to exit this
3219 hardware-protected mode is to drive W#/VPP HIGH.
3221 - SystemACE Support:
3224 Adding this option adds support for Xilinx SystemACE
3225 chips attached via some sort of local bus. The address
3226 of the chip must also be defined in the
3227 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3229 #define CONFIG_SYSTEMACE
3230 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3232 When SystemACE support is added, the "ace" device type
3233 becomes available to the fat commands, i.e. fatls.
3235 - TFTP Fixed UDP Port:
3238 If this is defined, the environment variable tftpsrcp
3239 is used to supply the TFTP UDP source port value.
3240 If tftpsrcp isn't defined, the normal pseudo-random port
3241 number generator is used.
3243 Also, the environment variable tftpdstp is used to supply
3244 the TFTP UDP destination port value. If tftpdstp isn't
3245 defined, the normal port 69 is used.
3247 The purpose for tftpsrcp is to allow a TFTP server to
3248 blindly start the TFTP transfer using the pre-configured
3249 target IP address and UDP port. This has the effect of
3250 "punching through" the (Windows XP) firewall, allowing
3251 the remainder of the TFTP transfer to proceed normally.
3252 A better solution is to properly configure the firewall,
3253 but sometimes that is not allowed.
3258 This enables a generic 'hash' command which can produce
3259 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3263 Enable the hash verify command (hash -v). This adds to code
3266 CONFIG_SHA1 - This option enables support of hashing using SHA1
3267 algorithm. The hash is calculated in software.
3268 CONFIG_SHA256 - This option enables support of hashing using
3269 SHA256 algorithm. The hash is calculated in software.
3270 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3271 for SHA1/SHA256 hashing.
3272 This affects the 'hash' command and also the
3273 hash_lookup_algo() function.
3274 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3275 hardware-acceleration for SHA1/SHA256 progressive hashing.
3276 Data can be streamed in a block at a time and the hashing
3277 is performed in hardware.
3279 Note: There is also a sha1sum command, which should perhaps
3280 be deprecated in favour of 'hash sha1'.
3282 - Freescale i.MX specific commands:
3283 CONFIG_CMD_HDMIDETECT
3284 This enables 'hdmidet' command which returns true if an
3285 HDMI monitor is detected. This command is i.MX 6 specific.
3288 This enables the 'bmode' (bootmode) command for forcing
3289 a boot from specific media.
3291 This is useful for forcing the ROM's usb downloader to
3292 activate upon a watchdog reset which is nice when iterating
3293 on U-Boot. Using the reset button or running bmode normal
3294 will set it back to normal. This command currently
3295 supports i.MX53 and i.MX6.
3300 This enables the RSA algorithm used for FIT image verification
3301 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3303 The Modular Exponentiation algorithm in RSA is implemented using
3304 driver model. So CONFIG_DM needs to be enabled by default for this
3305 library to function.
3307 The signing part is build into mkimage regardless of this
3308 option. The software based modular exponentiation is built into
3309 mkimage irrespective of this option.
3311 - bootcount support:
3312 CONFIG_BOOTCOUNT_LIMIT
3314 This enables the bootcounter support, see:
3315 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3318 enable special bootcounter support on at91sam9xe based boards.
3320 enable special bootcounter support on blackfin based boards.
3322 enable special bootcounter support on da850 based boards.
3323 CONFIG_BOOTCOUNT_RAM
3324 enable support for the bootcounter in RAM
3325 CONFIG_BOOTCOUNT_I2C
3326 enable support for the bootcounter on an i2c (like RTC) device.
3327 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3328 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3330 CONFIG_BOOTCOUNT_ALEN = address len
3332 - Show boot progress:
3333 CONFIG_SHOW_BOOT_PROGRESS
3335 Defining this option allows to add some board-
3336 specific code (calling a user-provided function
3337 "show_boot_progress(int)") that enables you to show
3338 the system's boot progress on some display (for
3339 example, some LED's) on your board. At the moment,
3340 the following checkpoints are implemented:
3343 Legacy uImage format:
3346 1 common/cmd_bootm.c before attempting to boot an image
3347 -1 common/cmd_bootm.c Image header has bad magic number
3348 2 common/cmd_bootm.c Image header has correct magic number
3349 -2 common/cmd_bootm.c Image header has bad checksum
3350 3 common/cmd_bootm.c Image header has correct checksum
3351 -3 common/cmd_bootm.c Image data has bad checksum
3352 4 common/cmd_bootm.c Image data has correct checksum
3353 -4 common/cmd_bootm.c Image is for unsupported architecture
3354 5 common/cmd_bootm.c Architecture check OK
3355 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3356 6 common/cmd_bootm.c Image Type check OK
3357 -6 common/cmd_bootm.c gunzip uncompression error
3358 -7 common/cmd_bootm.c Unimplemented compression type
3359 7 common/cmd_bootm.c Uncompression OK
3360 8 common/cmd_bootm.c No uncompress/copy overwrite error
3361 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3363 9 common/image.c Start initial ramdisk verification
3364 -10 common/image.c Ramdisk header has bad magic number
3365 -11 common/image.c Ramdisk header has bad checksum
3366 10 common/image.c Ramdisk header is OK
3367 -12 common/image.c Ramdisk data has bad checksum
3368 11 common/image.c Ramdisk data has correct checksum
3369 12 common/image.c Ramdisk verification complete, start loading
3370 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3371 13 common/image.c Start multifile image verification
3372 14 common/image.c No initial ramdisk, no multifile, continue.
3374 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3376 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3377 -31 post/post.c POST test failed, detected by post_output_backlog()
3378 -32 post/post.c POST test failed, detected by post_run_single()
3380 34 common/cmd_doc.c before loading a Image from a DOC device
3381 -35 common/cmd_doc.c Bad usage of "doc" command
3382 35 common/cmd_doc.c correct usage of "doc" command
3383 -36 common/cmd_doc.c No boot device
3384 36 common/cmd_doc.c correct boot device
3385 -37 common/cmd_doc.c Unknown Chip ID on boot device
3386 37 common/cmd_doc.c correct chip ID found, device available
3387 -38 common/cmd_doc.c Read Error on boot device
3388 38 common/cmd_doc.c reading Image header from DOC device OK
3389 -39 common/cmd_doc.c Image header has bad magic number
3390 39 common/cmd_doc.c Image header has correct magic number
3391 -40 common/cmd_doc.c Error reading Image from DOC device
3392 40 common/cmd_doc.c Image header has correct magic number
3393 41 common/cmd_ide.c before loading a Image from a IDE device
3394 -42 common/cmd_ide.c Bad usage of "ide" command
3395 42 common/cmd_ide.c correct usage of "ide" command
3396 -43 common/cmd_ide.c No boot device
3397 43 common/cmd_ide.c boot device found
3398 -44 common/cmd_ide.c Device not available
3399 44 common/cmd_ide.c Device available
3400 -45 common/cmd_ide.c wrong partition selected
3401 45 common/cmd_ide.c partition selected
3402 -46 common/cmd_ide.c Unknown partition table
3403 46 common/cmd_ide.c valid partition table found
3404 -47 common/cmd_ide.c Invalid partition type
3405 47 common/cmd_ide.c correct partition type
3406 -48 common/cmd_ide.c Error reading Image Header on boot device
3407 48 common/cmd_ide.c reading Image Header from IDE device OK
3408 -49 common/cmd_ide.c Image header has bad magic number
3409 49 common/cmd_ide.c Image header has correct magic number
3410 -50 common/cmd_ide.c Image header has bad checksum
3411 50 common/cmd_ide.c Image header has correct checksum
3412 -51 common/cmd_ide.c Error reading Image from IDE device
3413 51 common/cmd_ide.c reading Image from IDE device OK
3414 52 common/cmd_nand.c before loading a Image from a NAND device
3415 -53 common/cmd_nand.c Bad usage of "nand" command
3416 53 common/cmd_nand.c correct usage of "nand" command
3417 -54 common/cmd_nand.c No boot device
3418 54 common/cmd_nand.c boot device found
3419 -55 common/cmd_nand.c Unknown Chip ID on boot device
3420 55 common/cmd_nand.c correct chip ID found, device available
3421 -56 common/cmd_nand.c Error reading Image Header on boot device
3422 56 common/cmd_nand.c reading Image Header from NAND device OK
3423 -57 common/cmd_nand.c Image header has bad magic number
3424 57 common/cmd_nand.c Image header has correct magic number
3425 -58 common/cmd_nand.c Error reading Image from NAND device
3426 58 common/cmd_nand.c reading Image from NAND device OK
3428 -60 common/env_common.c Environment has a bad CRC, using default
3430 64 net/eth.c starting with Ethernet configuration.
3431 -64 net/eth.c no Ethernet found.
3432 65 net/eth.c Ethernet found.
3434 -80 common/cmd_net.c usage wrong
3435 80 common/cmd_net.c before calling net_loop()
3436 -81 common/cmd_net.c some error in net_loop() occurred
3437 81 common/cmd_net.c net_loop() back without error
3438 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3439 82 common/cmd_net.c trying automatic boot
3440 83 common/cmd_net.c running "source" command
3441 -83 common/cmd_net.c some error in automatic boot or "source" command
3442 84 common/cmd_net.c end without errors
3447 100 common/cmd_bootm.c Kernel FIT Image has correct format
3448 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3449 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3450 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3451 102 common/cmd_bootm.c Kernel unit name specified
3452 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3453 103 common/cmd_bootm.c Found configuration node
3454 104 common/cmd_bootm.c Got kernel subimage node offset
3455 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3456 105 common/cmd_bootm.c Kernel subimage hash verification OK
3457 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3458 106 common/cmd_bootm.c Architecture check OK
3459 -106 common/cmd_bootm.c Kernel subimage has wrong type
3460 107 common/cmd_bootm.c Kernel subimage type OK
3461 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3462 108 common/cmd_bootm.c Got kernel subimage data/size
3463 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3464 -109 common/cmd_bootm.c Can't get kernel subimage type
3465 -110 common/cmd_bootm.c Can't get kernel subimage comp
3466 -111 common/cmd_bootm.c Can't get kernel subimage os
3467 -112 common/cmd_bootm.c Can't get kernel subimage load address
3468 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3470 120 common/image.c Start initial ramdisk verification
3471 -120 common/image.c Ramdisk FIT image has incorrect format
3472 121 common/image.c Ramdisk FIT image has correct format
3473 122 common/image.c No ramdisk subimage unit name, using configuration
3474 -122 common/image.c Can't get configuration for ramdisk subimage
3475 123 common/image.c Ramdisk unit name specified
3476 -124 common/image.c Can't get ramdisk subimage node offset
3477 125 common/image.c Got ramdisk subimage node offset
3478 -125 common/image.c Ramdisk subimage hash verification failed
3479 126 common/image.c Ramdisk subimage hash verification OK
3480 -126 common/image.c Ramdisk subimage for unsupported architecture
3481 127 common/image.c Architecture check OK
3482 -127 common/image.c Can't get ramdisk subimage data/size
3483 128 common/image.c Got ramdisk subimage data/size
3484 129 common/image.c Can't get ramdisk load address
3485 -129 common/image.c Got ramdisk load address
3487 -130 common/cmd_doc.c Incorrect FIT image format
3488 131 common/cmd_doc.c FIT image format OK
3490 -140 common/cmd_ide.c Incorrect FIT image format
3491 141 common/cmd_ide.c FIT image format OK
3493 -150 common/cmd_nand.c Incorrect FIT image format
3494 151 common/cmd_nand.c FIT image format OK
3496 - legacy image format:
3497 CONFIG_IMAGE_FORMAT_LEGACY
3498 enables the legacy image format support in U-Boot.
3501 enabled if CONFIG_FIT_SIGNATURE is not defined.
3503 CONFIG_DISABLE_IMAGE_LEGACY
3504 disable the legacy image format
3506 This define is introduced, as the legacy image format is
3507 enabled per default for backward compatibility.
3509 - FIT image support:
3511 Enable support for the FIT uImage format.
3513 CONFIG_FIT_BEST_MATCH
3514 When no configuration is explicitly selected, default to the
3515 one whose fdt's compatibility field best matches that of
3516 U-Boot itself. A match is considered "best" if it matches the
3517 most specific compatibility entry of U-Boot's fdt's root node.
3518 The order of entries in the configuration's fdt is ignored.
3520 CONFIG_FIT_SIGNATURE
3521 This option enables signature verification of FIT uImages,
3522 using a hash signed and verified using RSA. If
3523 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3524 hashing is available using hardware, RSA library will use it.
3525 See doc/uImage.FIT/signature.txt for more details.
3527 WARNING: When relying on signed FIT images with required
3528 signature check the legacy image format is default
3529 disabled. If a board need legacy image format support
3530 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3532 CONFIG_FIT_DISABLE_SHA256
3533 Supporting SHA256 hashes has quite an impact on binary size.
3534 For constrained systems sha256 hash support can be disabled
3537 - Standalone program support:
3538 CONFIG_STANDALONE_LOAD_ADDR
3540 This option defines a board specific value for the
3541 address where standalone program gets loaded, thus
3542 overwriting the architecture dependent default
3545 - Frame Buffer Address:
3548 Define CONFIG_FB_ADDR if you want to use specific
3549 address for frame buffer. This is typically the case
3550 when using a graphics controller has separate video
3551 memory. U-Boot will then place the frame buffer at
3552 the given address instead of dynamically reserving it
3553 in system RAM by calling lcd_setmem(), which grabs
3554 the memory for the frame buffer depending on the
3555 configured panel size.
3557 Please see board_init_f function.
3559 - Automatic software updates via TFTP server
3561 CONFIG_UPDATE_TFTP_CNT_MAX
3562 CONFIG_UPDATE_TFTP_MSEC_MAX
3564 These options enable and control the auto-update feature;
3565 for a more detailed description refer to doc/README.update.
3567 - MTD Support (mtdparts command, UBI support)
3570 Adds the MTD device infrastructure from the Linux kernel.
3571 Needed for mtdparts command support.
3573 CONFIG_MTD_PARTITIONS
3575 Adds the MTD partitioning infrastructure from the Linux
3576 kernel. Needed for UBI support.
3581 Adds commands for interacting with MTD partitions formatted
3582 with the UBI flash translation layer
3584 Requires also defining CONFIG_RBTREE
3586 CONFIG_UBI_SILENCE_MSG
3588 Make the verbose messages from UBI stop printing. This leaves
3589 warnings and errors enabled.
3592 CONFIG_MTD_UBI_WL_THRESHOLD
3593 This parameter defines the maximum difference between the highest
3594 erase counter value and the lowest erase counter value of eraseblocks
3595 of UBI devices. When this threshold is exceeded, UBI starts performing
3596 wear leveling by means of moving data from eraseblock with low erase
3597 counter to eraseblocks with high erase counter.
3599 The default value should be OK for SLC NAND flashes, NOR flashes and
3600 other flashes which have eraseblock life-cycle 100000 or more.
3601 However, in case of MLC NAND flashes which typically have eraseblock
3602 life-cycle less than 10000, the threshold should be lessened (e.g.,
3603 to 128 or 256, although it does not have to be power of 2).
3607 CONFIG_MTD_UBI_BEB_LIMIT
3608 This option specifies the maximum bad physical eraseblocks UBI
3609 expects on the MTD device (per 1024 eraseblocks). If the
3610 underlying flash does not admit of bad eraseblocks (e.g. NOR
3611 flash), this value is ignored.
3613 NAND datasheets often specify the minimum and maximum NVM
3614 (Number of Valid Blocks) for the flashes' endurance lifetime.
3615 The maximum expected bad eraseblocks per 1024 eraseblocks
3616 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3617 which gives 20 for most NANDs (MaxNVB is basically the total
3618 count of eraseblocks on the chip).
3620 To put it differently, if this value is 20, UBI will try to
3621 reserve about 1.9% of physical eraseblocks for bad blocks
3622 handling. And that will be 1.9% of eraseblocks on the entire
3623 NAND chip, not just the MTD partition UBI attaches. This means
3624 that if you have, say, a NAND flash chip admits maximum 40 bad
3625 eraseblocks, and it is split on two MTD partitions of the same
3626 size, UBI will reserve 40 eraseblocks when attaching a
3631 CONFIG_MTD_UBI_FASTMAP
3632 Fastmap is a mechanism which allows attaching an UBI device
3633 in nearly constant time. Instead of scanning the whole MTD device it
3634 only has to locate a checkpoint (called fastmap) on the device.
3635 The on-flash fastmap contains all information needed to attach
3636 the device. Using fastmap makes only sense on large devices where
3637 attaching by scanning takes long. UBI will not automatically install
3638 a fastmap on old images, but you can set the UBI parameter
3639 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3640 that fastmap-enabled images are still usable with UBI implementations
3641 without fastmap support. On typical flash devices the whole fastmap
3642 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3644 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3645 Set this parameter to enable fastmap automatically on images
3652 Adds commands for interacting with UBI volumes formatted as
3653 UBIFS. UBIFS is read-only in u-boot.
3655 Requires UBI support as well as CONFIG_LZO
3657 CONFIG_UBIFS_SILENCE_MSG
3659 Make the verbose messages from UBIFS stop printing. This leaves
3660 warnings and errors enabled.
3664 Enable building of SPL globally.
3667 LDSCRIPT for linking the SPL binary.
3669 CONFIG_SPL_MAX_FOOTPRINT
3670 Maximum size in memory allocated to the SPL, BSS included.
3671 When defined, the linker checks that the actual memory
3672 used by SPL from _start to __bss_end does not exceed it.
3673 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3674 must not be both defined at the same time.
3677 Maximum size of the SPL image (text, data, rodata, and
3678 linker lists sections), BSS excluded.
3679 When defined, the linker checks that the actual size does
3682 CONFIG_SPL_TEXT_BASE
3683 TEXT_BASE for linking the SPL binary.
3685 CONFIG_SPL_RELOC_TEXT_BASE
3686 Address to relocate to. If unspecified, this is equal to
3687 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3689 CONFIG_SPL_BSS_START_ADDR
3690 Link address for the BSS within the SPL binary.
3692 CONFIG_SPL_BSS_MAX_SIZE
3693 Maximum size in memory allocated to the SPL BSS.
3694 When defined, the linker checks that the actual memory used
3695 by SPL from __bss_start to __bss_end does not exceed it.
3696 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3697 must not be both defined at the same time.
3700 Adress of the start of the stack SPL will use
3702 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3703 When defined, SPL will panic() if the image it has
3704 loaded does not have a signature.
3705 Defining this is useful when code which loads images
3706 in SPL cannot guarantee that absolutely all read errors
3708 An example is the LPC32XX MLC NAND driver, which will
3709 consider that a completely unreadable NAND block is bad,
3710 and thus should be skipped silently.
3712 CONFIG_SPL_RELOC_STACK
3713 Adress of the start of the stack SPL will use after
3714 relocation. If unspecified, this is equal to
3717 CONFIG_SYS_SPL_MALLOC_START
3718 Starting address of the malloc pool used in SPL.
3720 CONFIG_SYS_SPL_MALLOC_SIZE
3721 The size of the malloc pool used in SPL.
3723 CONFIG_SPL_FRAMEWORK
3724 Enable the SPL framework under common/. This framework
3725 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3726 NAND loading of the Linux Kernel.
3729 Enable booting directly to an OS from SPL.
3730 See also: doc/README.falcon
3732 CONFIG_SPL_DISPLAY_PRINT
3733 For ARM, enable an optional function to print more information
3734 about the running system.
3736 CONFIG_SPL_INIT_MINIMAL
3737 Arch init code should be built for a very small image
3739 CONFIG_SPL_LIBCOMMON_SUPPORT
3740 Support for common/libcommon.o in SPL binary
3742 CONFIG_SPL_LIBDISK_SUPPORT
3743 Support for disk/libdisk.o in SPL binary
3745 CONFIG_SPL_I2C_SUPPORT
3746 Support for drivers/i2c/libi2c.o in SPL binary
3748 CONFIG_SPL_GPIO_SUPPORT
3749 Support for drivers/gpio/libgpio.o in SPL binary
3751 CONFIG_SPL_MMC_SUPPORT
3752 Support for drivers/mmc/libmmc.o in SPL binary
3754 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3755 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3756 Address and partition on the MMC to load U-Boot from
3757 when the MMC is being used in raw mode.
3759 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3760 Partition on the MMC to load U-Boot from when the MMC is being
3763 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3764 Sector to load kernel uImage from when MMC is being
3765 used in raw mode (for Falcon mode)
3767 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3768 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3769 Sector and number of sectors to load kernel argument
3770 parameters from when MMC is being used in raw mode
3773 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3774 Partition on the MMC to load U-Boot from when the MMC is being
3777 CONFIG_SPL_FAT_SUPPORT
3778 Support for fs/fat/libfat.o in SPL binary
3780 CONFIG_SPL_EXT_SUPPORT
3781 Support for EXT filesystem in SPL binary
3783 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3784 Filename to read to load U-Boot when reading from filesystem
3786 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3787 Filename to read to load kernel uImage when reading
3788 from filesystem (for Falcon mode)
3790 CONFIG_SPL_FS_LOAD_ARGS_NAME
3791 Filename to read to load kernel argument parameters
3792 when reading from filesystem (for Falcon mode)
3794 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3795 Set this for NAND SPL on PPC mpc83xx targets, so that
3796 start.S waits for the rest of the SPL to load before
3797 continuing (the hardware starts execution after just
3798 loading the first page rather than the full 4K).
3800 CONFIG_SPL_SKIP_RELOCATE
3801 Avoid SPL relocation
3803 CONFIG_SPL_NAND_BASE
3804 Include nand_base.c in the SPL. Requires
3805 CONFIG_SPL_NAND_DRIVERS.
3807 CONFIG_SPL_NAND_DRIVERS
3808 SPL uses normal NAND drivers, not minimal drivers.
3811 Include standard software ECC in the SPL
3813 CONFIG_SPL_NAND_SIMPLE
3814 Support for NAND boot using simple NAND drivers that
3815 expose the cmd_ctrl() interface.
3817 CONFIG_SPL_MTD_SUPPORT
3818 Support for the MTD subsystem within SPL. Useful for
3819 environment on NAND support within SPL.
3821 CONFIG_SPL_NAND_RAW_ONLY
3822 Support to boot only raw u-boot.bin images. Use this only
3823 if you need to save space.
3825 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3826 Set for the SPL on PPC mpc8xxx targets, support for
3827 drivers/ddr/fsl/libddr.o in SPL binary.
3829 CONFIG_SPL_COMMON_INIT_DDR
3830 Set for common ddr init with serial presence detect in
3833 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3834 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3835 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3836 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3837 CONFIG_SYS_NAND_ECCBYTES
3838 Defines the size and behavior of the NAND that SPL uses
3841 CONFIG_SPL_NAND_BOOT
3842 Add support NAND boot
3844 CONFIG_SYS_NAND_U_BOOT_OFFS
3845 Location in NAND to read U-Boot from
3847 CONFIG_SYS_NAND_U_BOOT_DST
3848 Location in memory to load U-Boot to
3850 CONFIG_SYS_NAND_U_BOOT_SIZE
3851 Size of image to load
3853 CONFIG_SYS_NAND_U_BOOT_START
3854 Entry point in loaded image to jump to
3856 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3857 Define this if you need to first read the OOB and then the
3858 data. This is used, for example, on davinci platforms.
3860 CONFIG_SPL_OMAP3_ID_NAND
3861 Support for an OMAP3-specific set of functions to return the
3862 ID and MFR of the first attached NAND chip, if present.
3864 CONFIG_SPL_SERIAL_SUPPORT
3865 Support for drivers/serial/libserial.o in SPL binary
3867 CONFIG_SPL_SPI_FLASH_SUPPORT
3868 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3870 CONFIG_SPL_SPI_SUPPORT
3871 Support for drivers/spi/libspi.o in SPL binary
3873 CONFIG_SPL_RAM_DEVICE
3874 Support for running image already present in ram, in SPL binary
3876 CONFIG_SPL_LIBGENERIC_SUPPORT
3877 Support for lib/libgeneric.o in SPL binary
3879 CONFIG_SPL_ENV_SUPPORT
3880 Support for the environment operating in SPL binary
3882 CONFIG_SPL_NET_SUPPORT
3883 Support for the net/libnet.o in SPL binary.
3884 It conflicts with SPL env from storage medium specified by
3885 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3888 Image offset to which the SPL should be padded before appending
3889 the SPL payload. By default, this is defined as
3890 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3891 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3892 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3895 Final target image containing SPL and payload. Some SPLs
3896 use an arch-specific makefile fragment instead, for
3897 example if more than one image needs to be produced.
3899 CONFIG_FIT_SPL_PRINT
3900 Printing information about a FIT image adds quite a bit of
3901 code to SPL. So this is normally disabled in SPL. Use this
3902 option to re-enable it. This will affect the output of the
3903 bootm command when booting a FIT image.
3907 Enable building of TPL globally.
3910 Image offset to which the TPL should be padded before appending
3911 the TPL payload. By default, this is defined as
3912 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3913 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3914 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3919 [so far only for SMDK2400 boards]
3921 - Modem support enable:
3922 CONFIG_MODEM_SUPPORT
3924 - RTS/CTS Flow control enable:
3927 - Modem debug support:
3928 CONFIG_MODEM_SUPPORT_DEBUG
3930 Enables debugging stuff (char screen[1024], dbg())
3931 for modem support. Useful only with BDI2000.
3933 - Interrupt support (PPC):
3935 There are common interrupt_init() and timer_interrupt()
3936 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3937 for CPU specific initialization. interrupt_init_cpu()
3938 should set decrementer_count to appropriate value. If
3939 CPU resets decrementer automatically after interrupt
3940 (ppc4xx) it should set decrementer_count to zero.
3941 timer_interrupt() calls timer_interrupt_cpu() for CPU
3942 specific handling. If board has watchdog / status_led
3943 / other_activity_monitor it works automatically from
3944 general timer_interrupt().
3948 In the target system modem support is enabled when a
3949 specific key (key combination) is pressed during
3950 power-on. Otherwise U-Boot will boot normally
3951 (autoboot). The key_pressed() function is called from
3952 board_init(). Currently key_pressed() is a dummy
3953 function, returning 1 and thus enabling modem
3956 If there are no modem init strings in the
3957 environment, U-Boot proceed to autoboot; the
3958 previous output (banner, info printfs) will be
3961 See also: doc/README.Modem
3963 Board initialization settings:
3964 ------------------------------
3966 During Initialization u-boot calls a number of board specific functions
3967 to allow the preparation of board specific prerequisites, e.g. pin setup
3968 before drivers are initialized. To enable these callbacks the
3969 following configuration macros have to be defined. Currently this is
3970 architecture specific, so please check arch/your_architecture/lib/board.c
3971 typically in board_init_f() and board_init_r().
3973 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3974 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3975 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3976 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3978 Configuration Settings:
3979 -----------------------
3981 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3982 Optionally it can be defined to support 64-bit memory commands.
3984 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3985 undefine this when you're short of memory.
3987 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3988 width of the commands listed in the 'help' command output.
3990 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3991 prompt for user input.
3993 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3995 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3997 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3999 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
4000 the application (usually a Linux kernel) when it is
4003 - CONFIG_SYS_BAUDRATE_TABLE:
4004 List of legal baudrate settings for this board.
4006 - CONFIG_SYS_CONSOLE_INFO_QUIET
4007 Suppress display of console information at boot.
4009 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4010 If the board specific function
4011 extern int overwrite_console (void);
4012 returns 1, the stdin, stderr and stdout are switched to the
4013 serial port, else the settings in the environment are used.
4015 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4016 Enable the call to overwrite_console().
4018 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4019 Enable overwrite of previous console environment settings.
4021 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4022 Begin and End addresses of the area used by the
4025 - CONFIG_SYS_ALT_MEMTEST:
4026 Enable an alternate, more extensive memory test.
4028 - CONFIG_SYS_MEMTEST_SCRATCH:
4029 Scratch address used by the alternate memory test
4030 You only need to set this if address zero isn't writeable
4032 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4033 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4034 this specified memory area will get subtracted from the top
4035 (end) of RAM and won't get "touched" at all by U-Boot. By
4036 fixing up gd->ram_size the Linux kernel should gets passed
4037 the now "corrected" memory size and won't touch it either.
4038 This should work for arch/ppc and arch/powerpc. Only Linux
4039 board ports in arch/powerpc with bootwrapper support that
4040 recalculate the memory size from the SDRAM controller setup
4041 will have to get fixed in Linux additionally.
4043 This option can be used as a workaround for the 440EPx/GRx
4044 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4047 WARNING: Please make sure that this value is a multiple of
4048 the Linux page size (normally 4k). If this is not the case,
4049 then the end address of the Linux memory will be located at a
4050 non page size aligned address and this could cause major
4053 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4054 Enable temporary baudrate change while serial download
4056 - CONFIG_SYS_SDRAM_BASE:
4057 Physical start address of SDRAM. _Must_ be 0 here.
4059 - CONFIG_SYS_MBIO_BASE:
4060 Physical start address of Motherboard I/O (if using a
4063 - CONFIG_SYS_FLASH_BASE:
4064 Physical start address of Flash memory.
4066 - CONFIG_SYS_MONITOR_BASE:
4067 Physical start address of boot monitor code (set by
4068 make config files to be same as the text base address
4069 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4070 CONFIG_SYS_FLASH_BASE when booting from flash.
4072 - CONFIG_SYS_MONITOR_LEN:
4073 Size of memory reserved for monitor code, used to
4074 determine _at_compile_time_ (!) if the environment is
4075 embedded within the U-Boot image, or in a separate
4078 - CONFIG_SYS_MALLOC_LEN:
4079 Size of DRAM reserved for malloc() use.
4081 - CONFIG_SYS_MALLOC_F_LEN
4082 Size of the malloc() pool for use before relocation. If
4083 this is defined, then a very simple malloc() implementation
4084 will become available before relocation. The address is just
4085 below the global data, and the stack is moved down to make
4088 This feature allocates regions with increasing addresses
4089 within the region. calloc() is supported, but realloc()
4090 is not available. free() is supported but does nothing.
4091 The memory will be freed (or in fact just forgotten) when
4092 U-Boot relocates itself.
4094 Pre-relocation malloc() is only supported on ARM and sandbox
4095 at present but is fairly easy to enable for other archs.
4097 - CONFIG_SYS_MALLOC_SIMPLE
4098 Provides a simple and small malloc() and calloc() for those
4099 boards which do not use the full malloc in SPL (which is
4100 enabled with CONFIG_SYS_SPL_MALLOC_START).
4102 - CONFIG_SYS_NONCACHED_MEMORY:
4103 Size of non-cached memory area. This area of memory will be
4104 typically located right below the malloc() area and mapped
4105 uncached in the MMU. This is useful for drivers that would
4106 otherwise require a lot of explicit cache maintenance. For
4107 some drivers it's also impossible to properly maintain the
4108 cache. For example if the regions that need to be flushed
4109 are not a multiple of the cache-line size, *and* padding
4110 cannot be allocated between the regions to align them (i.e.
4111 if the HW requires a contiguous array of regions, and the
4112 size of each region is not cache-aligned), then a flush of
4113 one region may result in overwriting data that hardware has
4114 written to another region in the same cache-line. This can
4115 happen for example in network drivers where descriptors for
4116 buffers are typically smaller than the CPU cache-line (e.g.
4117 16 bytes vs. 32 or 64 bytes).
4119 Non-cached memory is only supported on 32-bit ARM at present.
4121 - CONFIG_SYS_BOOTM_LEN:
4122 Normally compressed uImages are limited to an
4123 uncompressed size of 8 MBytes. If this is not enough,
4124 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4125 to adjust this setting to your needs.
4127 - CONFIG_SYS_BOOTMAPSZ:
4128 Maximum size of memory mapped by the startup code of
4129 the Linux kernel; all data that must be processed by
4130 the Linux kernel (bd_info, boot arguments, FDT blob if
4131 used) must be put below this limit, unless "bootm_low"
4132 environment variable is defined and non-zero. In such case
4133 all data for the Linux kernel must be between "bootm_low"
4134 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4135 variable "bootm_mapsize" will override the value of
4136 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4137 then the value in "bootm_size" will be used instead.
4139 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4140 Enable initrd_high functionality. If defined then the
4141 initrd_high feature is enabled and the bootm ramdisk subcommand
4144 - CONFIG_SYS_BOOT_GET_CMDLINE:
4145 Enables allocating and saving kernel cmdline in space between
4146 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4148 - CONFIG_SYS_BOOT_GET_KBD:
4149 Enables allocating and saving a kernel copy of the bd_info in
4150 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4152 - CONFIG_SYS_MAX_FLASH_BANKS:
4153 Max number of Flash memory banks
4155 - CONFIG_SYS_MAX_FLASH_SECT:
4156 Max number of sectors on a Flash chip
4158 - CONFIG_SYS_FLASH_ERASE_TOUT:
4159 Timeout for Flash erase operations (in ms)
4161 - CONFIG_SYS_FLASH_WRITE_TOUT:
4162 Timeout for Flash write operations (in ms)
4164 - CONFIG_SYS_FLASH_LOCK_TOUT
4165 Timeout for Flash set sector lock bit operation (in ms)
4167 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4168 Timeout for Flash clear lock bits operation (in ms)
4170 - CONFIG_SYS_FLASH_PROTECTION
4171 If defined, hardware flash sectors protection is used
4172 instead of U-Boot software protection.
4174 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4176 Enable TFTP transfers directly to flash memory;
4177 without this option such a download has to be
4178 performed in two steps: (1) download to RAM, and (2)
4179 copy from RAM to flash.
4181 The two-step approach is usually more reliable, since
4182 you can check if the download worked before you erase
4183 the flash, but in some situations (when system RAM is
4184 too limited to allow for a temporary copy of the
4185 downloaded image) this option may be very useful.
4187 - CONFIG_SYS_FLASH_CFI:
4188 Define if the flash driver uses extra elements in the
4189 common flash structure for storing flash geometry.
4191 - CONFIG_FLASH_CFI_DRIVER
4192 This option also enables the building of the cfi_flash driver
4193 in the drivers directory
4195 - CONFIG_FLASH_CFI_MTD
4196 This option enables the building of the cfi_mtd driver
4197 in the drivers directory. The driver exports CFI flash
4200 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4201 Use buffered writes to flash.
4203 - CONFIG_FLASH_SPANSION_S29WS_N
4204 s29ws-n MirrorBit flash has non-standard addresses for buffered
4207 - CONFIG_SYS_FLASH_QUIET_TEST
4208 If this option is defined, the common CFI flash doesn't
4209 print it's warning upon not recognized FLASH banks. This
4210 is useful, if some of the configured banks are only
4211 optionally available.
4213 - CONFIG_FLASH_SHOW_PROGRESS
4214 If defined (must be an integer), print out countdown
4215 digits and dots. Recommended value: 45 (9..1) for 80
4216 column displays, 15 (3..1) for 40 column displays.
4218 - CONFIG_FLASH_VERIFY
4219 If defined, the content of the flash (destination) is compared
4220 against the source after the write operation. An error message
4221 will be printed when the contents are not identical.
4222 Please note that this option is useless in nearly all cases,
4223 since such flash programming errors usually are detected earlier
4224 while unprotecting/erasing/programming. Please only enable
4225 this option if you really know what you are doing.
4227 - CONFIG_SYS_RX_ETH_BUFFER:
4228 Defines the number of Ethernet receive buffers. On some
4229 Ethernet controllers it is recommended to set this value
4230 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4231 buffers can be full shortly after enabling the interface
4232 on high Ethernet traffic.
4233 Defaults to 4 if not defined.
4235 - CONFIG_ENV_MAX_ENTRIES
4237 Maximum number of entries in the hash table that is used
4238 internally to store the environment settings. The default
4239 setting is supposed to be generous and should work in most
4240 cases. This setting can be used to tune behaviour; see
4241 lib/hashtable.c for details.
4243 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4244 - CONFIG_ENV_FLAGS_LIST_STATIC
4245 Enable validation of the values given to environment variables when
4246 calling env set. Variables can be restricted to only decimal,
4247 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4248 the variables can also be restricted to IP address or MAC address.
4250 The format of the list is:
4251 type_attribute = [s|d|x|b|i|m]
4252 access_attribute = [a|r|o|c]
4253 attributes = type_attribute[access_attribute]
4254 entry = variable_name[:attributes]
4257 The type attributes are:
4258 s - String (default)
4261 b - Boolean ([1yYtT|0nNfF])
4265 The access attributes are:
4271 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4272 Define this to a list (string) to define the ".flags"
4273 environment variable in the default or embedded environment.
4275 - CONFIG_ENV_FLAGS_LIST_STATIC
4276 Define this to a list (string) to define validation that
4277 should be done if an entry is not found in the ".flags"
4278 environment variable. To override a setting in the static
4279 list, simply add an entry for the same variable name to the
4282 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4283 If defined, don't allow the -f switch to env set override variable
4286 - CONFIG_SYS_GENERIC_BOARD
4287 This selects the architecture-generic board system instead of the
4288 architecture-specific board files. It is intended to move boards
4289 to this new framework over time. Defining this will disable the
4290 arch/foo/lib/board.c file and use common/board_f.c and
4291 common/board_r.c instead. To use this option your architecture
4292 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4293 If you find problems enabling this option on your board please report
4294 the problem and send patches!
4296 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4297 This is set by OMAP boards for the max time that reset should
4298 be asserted. See doc/README.omap-reset-time for details on how
4299 the value can be calculated on a given board.
4302 If stdint.h is available with your toolchain you can define this
4303 option to enable it. You can provide option 'USE_STDINT=1' when
4304 building U-Boot to enable this.
4306 The following definitions that deal with the placement and management
4307 of environment data (variable area); in general, we support the
4308 following configurations:
4310 - CONFIG_BUILD_ENVCRC:
4312 Builds up envcrc with the target environment so that external utils
4313 may easily extract it and embed it in final U-Boot images.
4315 - CONFIG_ENV_IS_IN_FLASH:
4317 Define this if the environment is in flash memory.
4319 a) The environment occupies one whole flash sector, which is
4320 "embedded" in the text segment with the U-Boot code. This
4321 happens usually with "bottom boot sector" or "top boot
4322 sector" type flash chips, which have several smaller
4323 sectors at the start or the end. For instance, such a
4324 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4325 such a case you would place the environment in one of the
4326 4 kB sectors - with U-Boot code before and after it. With
4327 "top boot sector" type flash chips, you would put the
4328 environment in one of the last sectors, leaving a gap
4329 between U-Boot and the environment.
4331 - CONFIG_ENV_OFFSET:
4333 Offset of environment data (variable area) to the
4334 beginning of flash memory; for instance, with bottom boot
4335 type flash chips the second sector can be used: the offset
4336 for this sector is given here.
4338 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4342 This is just another way to specify the start address of
4343 the flash sector containing the environment (instead of
4346 - CONFIG_ENV_SECT_SIZE:
4348 Size of the sector containing the environment.
4351 b) Sometimes flash chips have few, equal sized, BIG sectors.
4352 In such a case you don't want to spend a whole sector for
4357 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4358 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4359 of this flash sector for the environment. This saves
4360 memory for the RAM copy of the environment.
4362 It may also save flash memory if you decide to use this
4363 when your environment is "embedded" within U-Boot code,
4364 since then the remainder of the flash sector could be used
4365 for U-Boot code. It should be pointed out that this is
4366 STRONGLY DISCOURAGED from a robustness point of view:
4367 updating the environment in flash makes it always
4368 necessary to erase the WHOLE sector. If something goes
4369 wrong before the contents has been restored from a copy in
4370 RAM, your target system will be dead.
4372 - CONFIG_ENV_ADDR_REDUND
4373 CONFIG_ENV_SIZE_REDUND
4375 These settings describe a second storage area used to hold
4376 a redundant copy of the environment data, so that there is
4377 a valid backup copy in case there is a power failure during
4378 a "saveenv" operation.
4380 BE CAREFUL! Any changes to the flash layout, and some changes to the
4381 source code will make it necessary to adapt <board>/u-boot.lds*
4385 - CONFIG_ENV_IS_IN_NVRAM:
4387 Define this if you have some non-volatile memory device
4388 (NVRAM, battery buffered SRAM) which you want to use for the
4394 These two #defines are used to determine the memory area you
4395 want to use for environment. It is assumed that this memory
4396 can just be read and written to, without any special
4399 BE CAREFUL! The first access to the environment happens quite early
4400 in U-Boot initialization (when we try to get the setting of for the
4401 console baudrate). You *MUST* have mapped your NVRAM area then, or
4404 Please note that even with NVRAM we still use a copy of the
4405 environment in RAM: we could work on NVRAM directly, but we want to
4406 keep settings there always unmodified except somebody uses "saveenv"
4407 to save the current settings.
4410 - CONFIG_ENV_IS_IN_EEPROM:
4412 Use this if you have an EEPROM or similar serial access
4413 device and a driver for it.
4415 - CONFIG_ENV_OFFSET:
4418 These two #defines specify the offset and size of the
4419 environment area within the total memory of your EEPROM.
4421 - CONFIG_SYS_I2C_EEPROM_ADDR:
4422 If defined, specified the chip address of the EEPROM device.
4423 The default address is zero.
4425 - CONFIG_SYS_I2C_EEPROM_BUS:
4426 If defined, specified the i2c bus of the EEPROM device.
4428 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4429 If defined, the number of bits used to address bytes in a
4430 single page in the EEPROM device. A 64 byte page, for example
4431 would require six bits.
4433 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4434 If defined, the number of milliseconds to delay between
4435 page writes. The default is zero milliseconds.
4437 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4438 The length in bytes of the EEPROM memory array address. Note
4439 that this is NOT the chip address length!
4441 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4442 EEPROM chips that implement "address overflow" are ones
4443 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4444 address and the extra bits end up in the "chip address" bit
4445 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4448 Note that we consider the length of the address field to
4449 still be one byte because the extra address bits are hidden
4450 in the chip address.
4452 - CONFIG_SYS_EEPROM_SIZE:
4453 The size in bytes of the EEPROM device.
4455 - CONFIG_ENV_EEPROM_IS_ON_I2C
4456 define this, if you have I2C and SPI activated, and your
4457 EEPROM, which holds the environment, is on the I2C bus.
4459 - CONFIG_I2C_ENV_EEPROM_BUS
4460 if you have an Environment on an EEPROM reached over
4461 I2C muxes, you can define here, how to reach this
4462 EEPROM. For example:
4464 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4466 EEPROM which holds the environment, is reached over
4467 a pca9547 i2c mux with address 0x70, channel 3.
4469 - CONFIG_ENV_IS_IN_DATAFLASH:
4471 Define this if you have a DataFlash memory device which you
4472 want to use for the environment.
4474 - CONFIG_ENV_OFFSET:
4478 These three #defines specify the offset and size of the
4479 environment area within the total memory of your DataFlash placed
4480 at the specified address.
4482 - CONFIG_ENV_IS_IN_SPI_FLASH:
4484 Define this if you have a SPI Flash memory device which you
4485 want to use for the environment.
4487 - CONFIG_ENV_OFFSET:
4490 These two #defines specify the offset and size of the
4491 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4492 aligned to an erase sector boundary.
4494 - CONFIG_ENV_SECT_SIZE:
4496 Define the SPI flash's sector size.
4498 - CONFIG_ENV_OFFSET_REDUND (optional):
4500 This setting describes a second storage area of CONFIG_ENV_SIZE
4501 size used to hold a redundant copy of the environment data, so
4502 that there is a valid backup copy in case there is a power failure
4503 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4504 aligned to an erase sector boundary.
4506 - CONFIG_ENV_SPI_BUS (optional):
4507 - CONFIG_ENV_SPI_CS (optional):
4509 Define the SPI bus and chip select. If not defined they will be 0.
4511 - CONFIG_ENV_SPI_MAX_HZ (optional):
4513 Define the SPI max work clock. If not defined then use 1MHz.
4515 - CONFIG_ENV_SPI_MODE (optional):
4517 Define the SPI work mode. If not defined then use SPI_MODE_3.
4519 - CONFIG_ENV_IS_IN_REMOTE:
4521 Define this if you have a remote memory space which you
4522 want to use for the local device's environment.
4527 These two #defines specify the address and size of the
4528 environment area within the remote memory space. The
4529 local device can get the environment from remote memory
4530 space by SRIO or PCIE links.
4532 BE CAREFUL! For some special cases, the local device can not use
4533 "saveenv" command. For example, the local device will get the
4534 environment stored in a remote NOR flash by SRIO or PCIE link,
4535 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4537 - CONFIG_ENV_IS_IN_NAND:
4539 Define this if you have a NAND device which you want to use
4540 for the environment.
4542 - CONFIG_ENV_OFFSET:
4545 These two #defines specify the offset and size of the environment
4546 area within the first NAND device. CONFIG_ENV_OFFSET must be
4547 aligned to an erase block boundary.
4549 - CONFIG_ENV_OFFSET_REDUND (optional):
4551 This setting describes a second storage area of CONFIG_ENV_SIZE
4552 size used to hold a redundant copy of the environment data, so
4553 that there is a valid backup copy in case there is a power failure
4554 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4555 aligned to an erase block boundary.
4557 - CONFIG_ENV_RANGE (optional):
4559 Specifies the length of the region in which the environment
4560 can be written. This should be a multiple of the NAND device's
4561 block size. Specifying a range with more erase blocks than
4562 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4563 the range to be avoided.
4565 - CONFIG_ENV_OFFSET_OOB (optional):
4567 Enables support for dynamically retrieving the offset of the
4568 environment from block zero's out-of-band data. The
4569 "nand env.oob" command can be used to record this offset.
4570 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4571 using CONFIG_ENV_OFFSET_OOB.
4573 - CONFIG_NAND_ENV_DST
4575 Defines address in RAM to which the nand_spl code should copy the
4576 environment. If redundant environment is used, it will be copied to
4577 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4579 - CONFIG_ENV_IS_IN_UBI:
4581 Define this if you have an UBI volume that you want to use for the
4582 environment. This has the benefit of wear-leveling the environment
4583 accesses, which is important on NAND.
4585 - CONFIG_ENV_UBI_PART:
4587 Define this to a string that is the mtd partition containing the UBI.
4589 - CONFIG_ENV_UBI_VOLUME:
4591 Define this to the name of the volume that you want to store the
4594 - CONFIG_ENV_UBI_VOLUME_REDUND:
4596 Define this to the name of another volume to store a second copy of
4597 the environment in. This will enable redundant environments in UBI.
4598 It is assumed that both volumes are in the same MTD partition.
4600 - CONFIG_UBI_SILENCE_MSG
4601 - CONFIG_UBIFS_SILENCE_MSG
4603 You will probably want to define these to avoid a really noisy system
4604 when storing the env in UBI.
4606 - CONFIG_ENV_IS_IN_FAT:
4607 Define this if you want to use the FAT file system for the environment.
4609 - FAT_ENV_INTERFACE:
4611 Define this to a string that is the name of the block device.
4613 - FAT_ENV_DEV_AND_PART:
4615 Define this to a string to specify the partition of the device. It can
4618 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4619 - "D:P": device D partition P. Error occurs if device D has no
4622 - "D" or "D:": device D partition 1 if device D has partition
4623 table, or the whole device D if has no partition
4625 - "D:auto": first partition in device D with bootable flag set.
4626 If none, first valid partition in device D. If no
4627 partition table then means device D.
4631 It's a string of the FAT file name. This file use to store the
4635 This should be defined. Otherwise it cannot save the environment file.
4637 - CONFIG_ENV_IS_IN_MMC:
4639 Define this if you have an MMC device which you want to use for the
4642 - CONFIG_SYS_MMC_ENV_DEV:
4644 Specifies which MMC device the environment is stored in.
4646 - CONFIG_SYS_MMC_ENV_PART (optional):
4648 Specifies which MMC partition the environment is stored in. If not
4649 set, defaults to partition 0, the user area. Common values might be
4650 1 (first MMC boot partition), 2 (second MMC boot partition).
4652 - CONFIG_ENV_OFFSET:
4655 These two #defines specify the offset and size of the environment
4656 area within the specified MMC device.
4658 If offset is positive (the usual case), it is treated as relative to
4659 the start of the MMC partition. If offset is negative, it is treated
4660 as relative to the end of the MMC partition. This can be useful if
4661 your board may be fitted with different MMC devices, which have
4662 different sizes for the MMC partitions, and you always want the
4663 environment placed at the very end of the partition, to leave the
4664 maximum possible space before it, to store other data.
4666 These two values are in units of bytes, but must be aligned to an
4667 MMC sector boundary.
4669 - CONFIG_ENV_OFFSET_REDUND (optional):
4671 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4672 hold a redundant copy of the environment data. This provides a
4673 valid backup copy in case the other copy is corrupted, e.g. due
4674 to a power failure during a "saveenv" operation.
4676 This value may also be positive or negative; this is handled in the
4677 same way as CONFIG_ENV_OFFSET.
4679 This value is also in units of bytes, but must also be aligned to
4680 an MMC sector boundary.
4682 - CONFIG_ENV_SIZE_REDUND (optional):
4684 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4685 set. If this value is set, it must be set to the same value as
4688 - CONFIG_SYS_SPI_INIT_OFFSET
4690 Defines offset to the initial SPI buffer area in DPRAM. The
4691 area is used at an early stage (ROM part) if the environment
4692 is configured to reside in the SPI EEPROM: We need a 520 byte
4693 scratch DPRAM area. It is used between the two initialization
4694 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4695 to be a good choice since it makes it far enough from the
4696 start of the data area as well as from the stack pointer.
4698 Please note that the environment is read-only until the monitor
4699 has been relocated to RAM and a RAM copy of the environment has been
4700 created; also, when using EEPROM you will have to use getenv_f()
4701 until then to read environment variables.
4703 The environment is protected by a CRC32 checksum. Before the monitor
4704 is relocated into RAM, as a result of a bad CRC you will be working
4705 with the compiled-in default environment - *silently*!!! [This is
4706 necessary, because the first environment variable we need is the
4707 "baudrate" setting for the console - if we have a bad CRC, we don't
4708 have any device yet where we could complain.]
4710 Note: once the monitor has been relocated, then it will complain if
4711 the default environment is used; a new CRC is computed as soon as you
4712 use the "saveenv" command to store a valid environment.
4714 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4715 Echo the inverted Ethernet link state to the fault LED.
4717 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4718 also needs to be defined.
4720 - CONFIG_SYS_FAULT_MII_ADDR:
4721 MII address of the PHY to check for the Ethernet link state.
4723 - CONFIG_NS16550_MIN_FUNCTIONS:
4724 Define this if you desire to only have use of the NS16550_init
4725 and NS16550_putc functions for the serial driver located at
4726 drivers/serial/ns16550.c. This option is useful for saving
4727 space for already greatly restricted images, including but not
4728 limited to NAND_SPL configurations.
4730 - CONFIG_DISPLAY_BOARDINFO
4731 Display information about the board that U-Boot is running on
4732 when U-Boot starts up. The board function checkboard() is called
4735 - CONFIG_DISPLAY_BOARDINFO_LATE
4736 Similar to the previous option, but display this information
4737 later, once stdio is running and output goes to the LCD, if
4740 - CONFIG_BOARD_SIZE_LIMIT:
4741 Maximum size of the U-Boot image. When defined, the
4742 build system checks that the actual size does not
4745 Low Level (hardware related) configuration options:
4746 ---------------------------------------------------
4748 - CONFIG_SYS_CACHELINE_SIZE:
4749 Cache Line Size of the CPU.
4751 - CONFIG_SYS_DEFAULT_IMMR:
4752 Default address of the IMMR after system reset.
4754 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4755 and RPXsuper) to be able to adjust the position of
4756 the IMMR register after a reset.
4758 - CONFIG_SYS_CCSRBAR_DEFAULT:
4759 Default (power-on reset) physical address of CCSR on Freescale
4762 - CONFIG_SYS_CCSRBAR:
4763 Virtual address of CCSR. On a 32-bit build, this is typically
4764 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4766 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4767 for cross-platform code that uses that macro instead.
4769 - CONFIG_SYS_CCSRBAR_PHYS:
4770 Physical address of CCSR. CCSR can be relocated to a new
4771 physical address, if desired. In this case, this macro should
4772 be set to that address. Otherwise, it should be set to the
4773 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4774 is typically relocated on 36-bit builds. It is recommended
4775 that this macro be defined via the _HIGH and _LOW macros:
4777 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4778 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4780 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4781 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4782 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4783 used in assembly code, so it must not contain typecasts or
4784 integer size suffixes (e.g. "ULL").
4786 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4787 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4788 used in assembly code, so it must not contain typecasts or
4789 integer size suffixes (e.g. "ULL").
4791 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4792 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4793 forced to a value that ensures that CCSR is not relocated.
4795 - Floppy Disk Support:
4796 CONFIG_SYS_FDC_DRIVE_NUMBER
4798 the default drive number (default value 0)
4800 CONFIG_SYS_ISA_IO_STRIDE
4802 defines the spacing between FDC chipset registers
4805 CONFIG_SYS_ISA_IO_OFFSET
4807 defines the offset of register from address. It
4808 depends on which part of the data bus is connected to
4809 the FDC chipset. (default value 0)
4811 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4812 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4815 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4816 fdc_hw_init() is called at the beginning of the FDC
4817 setup. fdc_hw_init() must be provided by the board
4818 source code. It is used to make hardware-dependent
4822 Most IDE controllers were designed to be connected with PCI
4823 interface. Only few of them were designed for AHB interface.
4824 When software is doing ATA command and data transfer to
4825 IDE devices through IDE-AHB controller, some additional
4826 registers accessing to these kind of IDE-AHB controller
4829 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4830 DO NOT CHANGE unless you know exactly what you're
4831 doing! (11-4) [MPC8xx/82xx systems only]
4833 - CONFIG_SYS_INIT_RAM_ADDR:
4835 Start address of memory area that can be used for
4836 initial data and stack; please note that this must be
4837 writable memory that is working WITHOUT special
4838 initialization, i. e. you CANNOT use normal RAM which
4839 will become available only after programming the
4840 memory controller and running certain initialization
4843 U-Boot uses the following memory types:
4844 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4845 - MPC824X: data cache
4846 - PPC4xx: data cache
4848 - CONFIG_SYS_GBL_DATA_OFFSET:
4850 Offset of the initial data structure in the memory
4851 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4852 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4853 data is located at the end of the available space
4854 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4855 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4856 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4857 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4860 On the MPC824X (or other systems that use the data
4861 cache for initial memory) the address chosen for
4862 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4863 point to an otherwise UNUSED address space between
4864 the top of RAM and the start of the PCI space.
4866 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4868 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4870 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4872 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4874 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4876 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4878 - CONFIG_SYS_OR_TIMING_SDRAM:
4881 - CONFIG_SYS_MAMR_PTA:
4882 periodic timer for refresh
4884 - CONFIG_SYS_DER: Debug Event Register (37-47)
4886 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4887 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4888 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4889 CONFIG_SYS_BR1_PRELIM:
4890 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4892 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4893 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4894 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4895 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4897 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4898 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4899 Machine Mode Register and Memory Periodic Timer
4900 Prescaler definitions (SDRAM timing)
4902 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4903 enable I2C microcode relocation patch (MPC8xx);
4904 define relocation offset in DPRAM [DSP2]
4906 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4907 enable SMC microcode relocation patch (MPC8xx);
4908 define relocation offset in DPRAM [SMC1]
4910 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4911 enable SPI microcode relocation patch (MPC8xx);
4912 define relocation offset in DPRAM [SCC4]
4914 - CONFIG_SYS_USE_OSCCLK:
4915 Use OSCM clock mode on MBX8xx board. Be careful,
4916 wrong setting might damage your board. Read
4917 doc/README.MBX before setting this variable!
4919 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4920 Offset of the bootmode word in DPRAM used by post
4921 (Power On Self Tests). This definition overrides
4922 #define'd default value in commproc.h resp.
4925 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4926 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4927 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4928 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4929 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4930 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4931 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4932 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4933 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4935 - CONFIG_PCI_DISABLE_PCIE:
4936 Disable PCI-Express on systems where it is supported but not
4939 - CONFIG_PCI_ENUM_ONLY
4940 Only scan through and get the devices on the buses.
4941 Don't do any setup work, presumably because someone or
4942 something has already done it, and we don't need to do it
4943 a second time. Useful for platforms that are pre-booted
4944 by coreboot or similar.
4946 - CONFIG_PCI_INDIRECT_BRIDGE:
4947 Enable support for indirect PCI bridges.
4950 Chip has SRIO or not
4953 Board has SRIO 1 port available
4956 Board has SRIO 2 port available
4958 - CONFIG_SRIO_PCIE_BOOT_MASTER
4959 Board can support master function for Boot from SRIO and PCIE
4961 - CONFIG_SYS_SRIOn_MEM_VIRT:
4962 Virtual Address of SRIO port 'n' memory region
4964 - CONFIG_SYS_SRIOn_MEM_PHYS:
4965 Physical Address of SRIO port 'n' memory region
4967 - CONFIG_SYS_SRIOn_MEM_SIZE:
4968 Size of SRIO port 'n' memory region
4970 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4971 Defined to tell the NAND controller that the NAND chip is using
4973 Not all NAND drivers use this symbol.
4974 Example of drivers that use it:
4975 - drivers/mtd/nand/ndfc.c
4976 - drivers/mtd/nand/mxc_nand.c
4978 - CONFIG_SYS_NDFC_EBC0_CFG
4979 Sets the EBC0_CFG register for the NDFC. If not defined
4980 a default value will be used.
4983 Get DDR timing information from an I2C EEPROM. Common
4984 with pluggable memory modules such as SODIMMs
4987 I2C address of the SPD EEPROM
4989 - CONFIG_SYS_SPD_BUS_NUM
4990 If SPD EEPROM is on an I2C bus other than the first
4991 one, specify here. Note that the value must resolve
4992 to something your driver can deal with.
4994 - CONFIG_SYS_DDR_RAW_TIMING
4995 Get DDR timing information from other than SPD. Common with
4996 soldered DDR chips onboard without SPD. DDR raw timing
4997 parameters are extracted from datasheet and hard-coded into
4998 header files or board specific files.
5000 - CONFIG_FSL_DDR_INTERACTIVE
5001 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5003 - CONFIG_FSL_DDR_SYNC_REFRESH
5004 Enable sync of refresh for multiple controllers.
5006 - CONFIG_SYS_83XX_DDR_USES_CS0
5007 Only for 83xx systems. If specified, then DDR should
5008 be configured using CS0 and CS1 instead of CS2 and CS3.
5010 - CONFIG_ETHER_ON_FEC[12]
5011 Define to enable FEC[12] on a 8xx series processor.
5013 - CONFIG_FEC[12]_PHY
5014 Define to the hardcoded PHY address which corresponds
5015 to the given FEC; i. e.
5016 #define CONFIG_FEC1_PHY 4
5017 means that the PHY with address 4 is connected to FEC1
5019 When set to -1, means to probe for first available.
5021 - CONFIG_FEC[12]_PHY_NORXERR
5022 The PHY does not have a RXERR line (RMII only).
5023 (so program the FEC to ignore it).
5026 Enable RMII mode for all FECs.
5027 Note that this is a global option, we can't
5028 have one FEC in standard MII mode and another in RMII mode.
5030 - CONFIG_CRC32_VERIFY
5031 Add a verify option to the crc32 command.
5034 => crc32 -v <address> <count> <crc32>
5036 Where address/count indicate a memory area
5037 and crc32 is the correct crc32 which the
5041 Add the "loopw" memory command. This only takes effect if
5042 the memory commands are activated globally (CONFIG_CMD_MEM).
5045 Add the "mdc" and "mwc" memory commands. These are cyclic
5050 This command will print 4 bytes (10,11,12,13) each 500 ms.
5052 => mwc.l 100 12345678 10
5053 This command will write 12345678 to address 100 all 10 ms.
5055 This only takes effect if the memory commands are activated
5056 globally (CONFIG_CMD_MEM).
5058 - CONFIG_SKIP_LOWLEVEL_INIT
5059 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5060 low level initializations (like setting up the memory
5061 controller) are omitted and/or U-Boot does not
5062 relocate itself into RAM.
5064 Normally this variable MUST NOT be defined. The only
5065 exception is when U-Boot is loaded (to RAM) by some
5066 other boot loader or by a debugger which performs
5067 these initializations itself.
5070 Modifies the behaviour of start.S when compiling a loader
5071 that is executed before the actual U-Boot. E.g. when
5072 compiling a NAND SPL.
5075 Modifies the behaviour of start.S when compiling a loader
5076 that is executed after the SPL and before the actual U-Boot.
5077 It is loaded by the SPL.
5079 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5080 Only for 85xx systems. If this variable is specified, the section
5081 .resetvec is not kept and the section .bootpg is placed in the
5082 previous 4k of the .text section.
5084 - CONFIG_ARCH_MAP_SYSMEM
5085 Generally U-Boot (and in particular the md command) uses
5086 effective address. It is therefore not necessary to regard
5087 U-Boot address as virtual addresses that need to be translated
5088 to physical addresses. However, sandbox requires this, since
5089 it maintains its own little RAM buffer which contains all
5090 addressable memory. This option causes some memory accesses
5091 to be mapped through map_sysmem() / unmap_sysmem().
5093 - CONFIG_USE_ARCH_MEMCPY
5094 CONFIG_USE_ARCH_MEMSET
5095 If these options are used a optimized version of memcpy/memset will
5096 be used if available. These functions may be faster under some
5097 conditions but may increase the binary size.
5099 - CONFIG_X86_RESET_VECTOR
5100 If defined, the x86 reset vector code is included. This is not
5101 needed when U-Boot is running from Coreboot.
5104 Defines the MPU clock speed (in MHz).
5106 NOTE : currently only supported on AM335x platforms.
5108 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5109 Enables the RTC32K OSC on AM33xx based plattforms
5111 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5112 Option to disable subpage write in NAND driver
5113 driver that uses this:
5114 drivers/mtd/nand/davinci_nand.c
5116 Freescale QE/FMAN Firmware Support:
5117 -----------------------------------
5119 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5120 loading of "firmware", which is encoded in the QE firmware binary format.
5121 This firmware often needs to be loaded during U-Boot booting, so macros
5122 are used to identify the storage device (NOR flash, SPI, etc) and the address
5125 - CONFIG_SYS_FMAN_FW_ADDR
5126 The address in the storage device where the FMAN microcode is located. The
5127 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5130 - CONFIG_SYS_QE_FW_ADDR
5131 The address in the storage device where the QE microcode is located. The
5132 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5135 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5136 The maximum possible size of the firmware. The firmware binary format
5137 has a field that specifies the actual size of the firmware, but it
5138 might not be possible to read any part of the firmware unless some
5139 local storage is allocated to hold the entire firmware first.
5141 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5142 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5143 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5144 virtual address in NOR flash.
5146 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5147 Specifies that QE/FMAN firmware is located in NAND flash.
5148 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5150 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5151 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5152 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5154 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5155 Specifies that QE/FMAN firmware is located on the primary SPI
5156 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5158 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5159 Specifies that QE/FMAN firmware is located in the remote (master)
5160 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5161 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5162 window->master inbound window->master LAW->the ucode address in
5163 master's memory space.
5165 Freescale Layerscape Management Complex Firmware Support:
5166 ---------------------------------------------------------
5167 The Freescale Layerscape Management Complex (MC) supports the loading of
5169 This firmware often needs to be loaded during U-Boot booting, so macros
5170 are used to identify the storage device (NOR flash, SPI, etc) and the address
5173 - CONFIG_FSL_MC_ENET
5174 Enable the MC driver for Layerscape SoCs.
5176 - CONFIG_SYS_LS_MC_FW_ADDR
5177 The address in the storage device where the firmware is located. The
5178 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5181 - CONFIG_SYS_LS_MC_FW_LENGTH
5182 The maximum possible size of the firmware. The firmware binary format
5183 has a field that specifies the actual size of the firmware, but it
5184 might not be possible to read any part of the firmware unless some
5185 local storage is allocated to hold the entire firmware first.
5187 - CONFIG_SYS_LS_MC_FW_IN_NOR
5188 Specifies that MC firmware is located in NOR flash, mapped as
5189 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5190 virtual address in NOR flash.
5192 Building the Software:
5193 ======================
5195 Building U-Boot has been tested in several native build environments
5196 and in many different cross environments. Of course we cannot support
5197 all possibly existing versions of cross development tools in all
5198 (potentially obsolete) versions. In case of tool chain problems we
5199 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5200 which is extensively used to build and test U-Boot.
5202 If you are not using a native environment, it is assumed that you
5203 have GNU cross compiling tools available in your path. In this case,
5204 you must set the environment variable CROSS_COMPILE in your shell.
5205 Note that no changes to the Makefile or any other source files are
5206 necessary. For example using the ELDK on a 4xx CPU, please enter:
5208 $ CROSS_COMPILE=ppc_4xx-
5209 $ export CROSS_COMPILE
5211 Note: If you wish to generate Windows versions of the utilities in
5212 the tools directory you can use the MinGW toolchain
5213 (http://www.mingw.org). Set your HOST tools to the MinGW
5214 toolchain and execute 'make tools'. For example:
5216 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5218 Binaries such as tools/mkimage.exe will be created which can
5219 be executed on computers running Windows.
5221 U-Boot is intended to be simple to build. After installing the
5222 sources you must configure U-Boot for one specific board type. This
5227 where "NAME_defconfig" is the name of one of the existing configu-
5228 rations; see boards.cfg for supported names.
5230 Note: for some board special configuration names may exist; check if
5231 additional information is available from the board vendor; for
5232 instance, the TQM823L systems are available without (standard)
5233 or with LCD support. You can select such additional "features"
5234 when choosing the configuration, i. e.
5236 make TQM823L_defconfig
5237 - will configure for a plain TQM823L, i. e. no LCD support
5239 make TQM823L_LCD_defconfig
5240 - will configure for a TQM823L with U-Boot console on LCD
5245 Finally, type "make all", and you should get some working U-Boot
5246 images ready for download to / installation on your system:
5248 - "u-boot.bin" is a raw binary image
5249 - "u-boot" is an image in ELF binary format
5250 - "u-boot.srec" is in Motorola S-Record format
5252 By default the build is performed locally and the objects are saved
5253 in the source directory. One of the two methods can be used to change
5254 this behavior and build U-Boot to some external directory:
5256 1. Add O= to the make command line invocations:
5258 make O=/tmp/build distclean
5259 make O=/tmp/build NAME_defconfig
5260 make O=/tmp/build all
5262 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5264 export KBUILD_OUTPUT=/tmp/build
5269 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5273 Please be aware that the Makefiles assume you are using GNU make, so
5274 for instance on NetBSD you might need to use "gmake" instead of
5278 If the system board that you have is not listed, then you will need
5279 to port U-Boot to your hardware platform. To do this, follow these
5282 1. Add a new configuration option for your board to the toplevel
5283 "boards.cfg" file, using the existing entries as examples.
5284 Follow the instructions there to keep the boards in order.
5285 2. Create a new directory to hold your board specific code. Add any
5286 files you need. In your board directory, you will need at least
5287 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5288 3. Create a new configuration file "include/configs/<board>.h" for
5290 3. If you're porting U-Boot to a new CPU, then also create a new
5291 directory to hold your CPU specific code. Add any files you need.
5292 4. Run "make <board>_defconfig" with your new name.
5293 5. Type "make", and you should get a working "u-boot.srec" file
5294 to be installed on your target system.
5295 6. Debug and solve any problems that might arise.
5296 [Of course, this last step is much harder than it sounds.]
5299 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5300 ==============================================================
5302 If you have modified U-Boot sources (for instance added a new board
5303 or support for new devices, a new CPU, etc.) you are expected to
5304 provide feedback to the other developers. The feedback normally takes
5305 the form of a "patch", i. e. a context diff against a certain (latest
5306 official or latest in the git repository) version of U-Boot sources.
5308 But before you submit such a patch, please verify that your modifi-
5309 cation did not break existing code. At least make sure that *ALL* of
5310 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5311 just run the "MAKEALL" script, which will configure and build U-Boot
5312 for ALL supported system. Be warned, this will take a while. You can
5313 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5314 environment variable to the script, i. e. to use the ELDK cross tools
5317 CROSS_COMPILE=ppc_8xx- MAKEALL
5319 or to build on a native PowerPC system you can type
5321 CROSS_COMPILE=' ' MAKEALL
5323 When using the MAKEALL script, the default behaviour is to build
5324 U-Boot in the source directory. This location can be changed by
5325 setting the BUILD_DIR environment variable. Also, for each target
5326 built, the MAKEALL script saves two log files (<target>.ERR and
5327 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5328 location can be changed by setting the MAKEALL_LOGDIR environment
5329 variable. For example:
5331 export BUILD_DIR=/tmp/build
5332 export MAKEALL_LOGDIR=/tmp/log
5333 CROSS_COMPILE=ppc_8xx- MAKEALL
5335 With the above settings build objects are saved in the /tmp/build,
5336 log files are saved in the /tmp/log and the source tree remains clean
5337 during the whole build process.
5340 See also "U-Boot Porting Guide" below.
5343 Monitor Commands - Overview:
5344 ============================
5346 go - start application at address 'addr'
5347 run - run commands in an environment variable
5348 bootm - boot application image from memory
5349 bootp - boot image via network using BootP/TFTP protocol
5350 bootz - boot zImage from memory
5351 tftpboot- boot image via network using TFTP protocol
5352 and env variables "ipaddr" and "serverip"
5353 (and eventually "gatewayip")
5354 tftpput - upload a file via network using TFTP protocol
5355 rarpboot- boot image via network using RARP/TFTP protocol
5356 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5357 loads - load S-Record file over serial line
5358 loadb - load binary file over serial line (kermit mode)
5360 mm - memory modify (auto-incrementing)
5361 nm - memory modify (constant address)
5362 mw - memory write (fill)
5364 cmp - memory compare
5365 crc32 - checksum calculation
5366 i2c - I2C sub-system
5367 sspi - SPI utility commands
5368 base - print or set address offset
5369 printenv- print environment variables
5370 setenv - set environment variables
5371 saveenv - save environment variables to persistent storage
5372 protect - enable or disable FLASH write protection
5373 erase - erase FLASH memory
5374 flinfo - print FLASH memory information
5375 nand - NAND memory operations (see doc/README.nand)
5376 bdinfo - print Board Info structure
5377 iminfo - print header information for application image
5378 coninfo - print console devices and informations
5379 ide - IDE sub-system
5380 loop - infinite loop on address range
5381 loopw - infinite write loop on address range
5382 mtest - simple RAM test
5383 icache - enable or disable instruction cache
5384 dcache - enable or disable data cache
5385 reset - Perform RESET of the CPU
5386 echo - echo args to console
5387 version - print monitor version
5388 help - print online help
5389 ? - alias for 'help'
5392 Monitor Commands - Detailed Description:
5393 ========================================
5397 For now: just type "help <command>".
5400 Environment Variables:
5401 ======================
5403 U-Boot supports user configuration using Environment Variables which
5404 can be made persistent by saving to Flash memory.
5406 Environment Variables are set using "setenv", printed using
5407 "printenv", and saved to Flash using "saveenv". Using "setenv"
5408 without a value can be used to delete a variable from the
5409 environment. As long as you don't save the environment you are
5410 working with an in-memory copy. In case the Flash area containing the
5411 environment is erased by accident, a default environment is provided.
5413 Some configuration options can be set using Environment Variables.
5415 List of environment variables (most likely not complete):
5417 baudrate - see CONFIG_BAUDRATE
5419 bootdelay - see CONFIG_BOOTDELAY
5421 bootcmd - see CONFIG_BOOTCOMMAND
5423 bootargs - Boot arguments when booting an RTOS image
5425 bootfile - Name of the image to load with TFTP
5427 bootm_low - Memory range available for image processing in the bootm
5428 command can be restricted. This variable is given as
5429 a hexadecimal number and defines lowest address allowed
5430 for use by the bootm command. See also "bootm_size"
5431 environment variable. Address defined by "bootm_low" is
5432 also the base of the initial memory mapping for the Linux
5433 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5436 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5437 This variable is given as a hexadecimal number and it
5438 defines the size of the memory region starting at base
5439 address bootm_low that is accessible by the Linux kernel
5440 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5441 as the default value if it is defined, and bootm_size is
5444 bootm_size - Memory range available for image processing in the bootm
5445 command can be restricted. This variable is given as
5446 a hexadecimal number and defines the size of the region
5447 allowed for use by the bootm command. See also "bootm_low"
5448 environment variable.
5450 updatefile - Location of the software update file on a TFTP server, used
5451 by the automatic software update feature. Please refer to
5452 documentation in doc/README.update for more details.
5454 autoload - if set to "no" (any string beginning with 'n'),
5455 "bootp" will just load perform a lookup of the
5456 configuration from the BOOTP server, but not try to
5457 load any image using TFTP
5459 autostart - if set to "yes", an image loaded using the "bootp",
5460 "rarpboot", "tftpboot" or "diskboot" commands will
5461 be automatically started (by internally calling
5464 If set to "no", a standalone image passed to the
5465 "bootm" command will be copied to the load address
5466 (and eventually uncompressed), but NOT be started.
5467 This can be used to load and uncompress arbitrary
5470 fdt_high - if set this restricts the maximum address that the
5471 flattened device tree will be copied into upon boot.
5472 For example, if you have a system with 1 GB memory
5473 at physical address 0x10000000, while Linux kernel
5474 only recognizes the first 704 MB as low memory, you
5475 may need to set fdt_high as 0x3C000000 to have the
5476 device tree blob be copied to the maximum address
5477 of the 704 MB low memory, so that Linux kernel can
5478 access it during the boot procedure.
5480 If this is set to the special value 0xFFFFFFFF then
5481 the fdt will not be copied at all on boot. For this
5482 to work it must reside in writable memory, have
5483 sufficient padding on the end of it for u-boot to
5484 add the information it needs into it, and the memory
5485 must be accessible by the kernel.
5487 fdtcontroladdr- if set this is the address of the control flattened
5488 device tree used by U-Boot when CONFIG_OF_CONTROL is
5491 i2cfast - (PPC405GP|PPC405EP only)
5492 if set to 'y' configures Linux I2C driver for fast
5493 mode (400kHZ). This environment variable is used in
5494 initialization code. So, for changes to be effective
5495 it must be saved and board must be reset.
5497 initrd_high - restrict positioning of initrd images:
5498 If this variable is not set, initrd images will be
5499 copied to the highest possible address in RAM; this
5500 is usually what you want since it allows for
5501 maximum initrd size. If for some reason you want to
5502 make sure that the initrd image is loaded below the
5503 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5504 variable to a value of "no" or "off" or "0".
5505 Alternatively, you can set it to a maximum upper
5506 address to use (U-Boot will still check that it
5507 does not overwrite the U-Boot stack and data).
5509 For instance, when you have a system with 16 MB
5510 RAM, and want to reserve 4 MB from use by Linux,
5511 you can do this by adding "mem=12M" to the value of
5512 the "bootargs" variable. However, now you must make
5513 sure that the initrd image is placed in the first
5514 12 MB as well - this can be done with
5516 setenv initrd_high 00c00000
5518 If you set initrd_high to 0xFFFFFFFF, this is an
5519 indication to U-Boot that all addresses are legal
5520 for the Linux kernel, including addresses in flash
5521 memory. In this case U-Boot will NOT COPY the
5522 ramdisk at all. This may be useful to reduce the
5523 boot time on your system, but requires that this
5524 feature is supported by your Linux kernel.
5526 ipaddr - IP address; needed for tftpboot command
5528 loadaddr - Default load address for commands like "bootp",
5529 "rarpboot", "tftpboot", "loadb" or "diskboot"
5531 loads_echo - see CONFIG_LOADS_ECHO
5533 serverip - TFTP server IP address; needed for tftpboot command
5535 bootretry - see CONFIG_BOOT_RETRY_TIME
5537 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5539 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5541 ethprime - controls which interface is used first.
5543 ethact - controls which interface is currently active.
5544 For example you can do the following
5546 => setenv ethact FEC
5547 => ping 192.168.0.1 # traffic sent on FEC
5548 => setenv ethact SCC
5549 => ping 10.0.0.1 # traffic sent on SCC
5551 ethrotate - When set to "no" U-Boot does not go through all
5552 available network interfaces.
5553 It just stays at the currently selected interface.
5555 netretry - When set to "no" each network operation will
5556 either succeed or fail without retrying.
5557 When set to "once" the network operation will
5558 fail when all the available network interfaces
5559 are tried once without success.
5560 Useful on scripts which control the retry operation
5563 npe_ucode - set load address for the NPE microcode
5565 silent_linux - If set then Linux will be told to boot silently, by
5566 changing the console to be empty. If "yes" it will be
5567 made silent. If "no" it will not be made silent. If
5568 unset, then it will be made silent if the U-Boot console
5571 tftpsrcport - If this is set, the value is used for TFTP's
5574 tftpdstport - If this is set, the value is used for TFTP's UDP
5575 destination port instead of the Well Know Port 69.
5577 tftpblocksize - Block size to use for TFTP transfers; if not set,
5578 we use the TFTP server's default block size
5580 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5581 seconds, minimum value is 1000 = 1 second). Defines
5582 when a packet is considered to be lost so it has to
5583 be retransmitted. The default is 5000 = 5 seconds.
5584 Lowering this value may make downloads succeed
5585 faster in networks with high packet loss rates or
5586 with unreliable TFTP servers.
5588 vlan - When set to a value < 4095 the traffic over
5589 Ethernet is encapsulated/received over 802.1q
5592 The following image location variables contain the location of images
5593 used in booting. The "Image" column gives the role of the image and is
5594 not an environment variable name. The other columns are environment
5595 variable names. "File Name" gives the name of the file on a TFTP
5596 server, "RAM Address" gives the location in RAM the image will be
5597 loaded to, and "Flash Location" gives the image's address in NOR
5598 flash or offset in NAND flash.
5600 *Note* - these variables don't have to be defined for all boards, some
5601 boards currenlty use other variables for these purposes, and some
5602 boards use these variables for other purposes.
5604 Image File Name RAM Address Flash Location
5605 ----- --------- ----------- --------------
5606 u-boot u-boot u-boot_addr_r u-boot_addr
5607 Linux kernel bootfile kernel_addr_r kernel_addr
5608 device tree blob fdtfile fdt_addr_r fdt_addr
5609 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5611 The following environment variables may be used and automatically
5612 updated by the network boot commands ("bootp" and "rarpboot"),
5613 depending the information provided by your boot server:
5615 bootfile - see above
5616 dnsip - IP address of your Domain Name Server
5617 dnsip2 - IP address of your secondary Domain Name Server
5618 gatewayip - IP address of the Gateway (Router) to use
5619 hostname - Target hostname
5621 netmask - Subnet Mask
5622 rootpath - Pathname of the root filesystem on the NFS server
5623 serverip - see above
5626 There are two special Environment Variables:
5628 serial# - contains hardware identification information such
5629 as type string and/or serial number
5630 ethaddr - Ethernet address
5632 These variables can be set only once (usually during manufacturing of
5633 the board). U-Boot refuses to delete or overwrite these variables
5634 once they have been set once.
5637 Further special Environment Variables:
5639 ver - Contains the U-Boot version string as printed
5640 with the "version" command. This variable is
5641 readonly (see CONFIG_VERSION_VARIABLE).
5644 Please note that changes to some configuration parameters may take
5645 only effect after the next boot (yes, that's just like Windoze :-).
5648 Callback functions for environment variables:
5649 ---------------------------------------------
5651 For some environment variables, the behavior of u-boot needs to change
5652 when their values are changed. This functionality allows functions to
5653 be associated with arbitrary variables. On creation, overwrite, or
5654 deletion, the callback will provide the opportunity for some side
5655 effect to happen or for the change to be rejected.
5657 The callbacks are named and associated with a function using the
5658 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5660 These callbacks are associated with variables in one of two ways. The
5661 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5662 in the board configuration to a string that defines a list of
5663 associations. The list must be in the following format:
5665 entry = variable_name[:callback_name]
5668 If the callback name is not specified, then the callback is deleted.
5669 Spaces are also allowed anywhere in the list.
5671 Callbacks can also be associated by defining the ".callbacks" variable
5672 with the same list format above. Any association in ".callbacks" will
5673 override any association in the static list. You can define
5674 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5675 ".callbacks" environment variable in the default or embedded environment.
5678 Command Line Parsing:
5679 =====================
5681 There are two different command line parsers available with U-Boot:
5682 the old "simple" one, and the much more powerful "hush" shell:
5684 Old, simple command line parser:
5685 --------------------------------
5687 - supports environment variables (through setenv / saveenv commands)
5688 - several commands on one line, separated by ';'
5689 - variable substitution using "... ${name} ..." syntax
5690 - special characters ('$', ';') can be escaped by prefixing with '\',
5692 setenv bootcmd bootm \${address}
5693 - You can also escape text by enclosing in single apostrophes, for example:
5694 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5699 - similar to Bourne shell, with control structures like
5700 if...then...else...fi, for...do...done; while...do...done,
5701 until...do...done, ...
5702 - supports environment ("global") variables (through setenv / saveenv
5703 commands) and local shell variables (through standard shell syntax
5704 "name=value"); only environment variables can be used with "run"
5710 (1) If a command line (or an environment variable executed by a "run"
5711 command) contains several commands separated by semicolon, and
5712 one of these commands fails, then the remaining commands will be
5715 (2) If you execute several variables with one call to run (i. e.
5716 calling run with a list of variables as arguments), any failing
5717 command will cause "run" to terminate, i. e. the remaining
5718 variables are not executed.
5720 Note for Redundant Ethernet Interfaces:
5721 =======================================
5723 Some boards come with redundant Ethernet interfaces; U-Boot supports
5724 such configurations and is capable of automatic selection of a
5725 "working" interface when needed. MAC assignment works as follows:
5727 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5728 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5729 "eth1addr" (=>eth1), "eth2addr", ...
5731 If the network interface stores some valid MAC address (for instance
5732 in SROM), this is used as default address if there is NO correspon-
5733 ding setting in the environment; if the corresponding environment
5734 variable is set, this overrides the settings in the card; that means:
5736 o If the SROM has a valid MAC address, and there is no address in the
5737 environment, the SROM's address is used.
5739 o If there is no valid address in the SROM, and a definition in the
5740 environment exists, then the value from the environment variable is
5743 o If both the SROM and the environment contain a MAC address, and
5744 both addresses are the same, this MAC address is used.
5746 o If both the SROM and the environment contain a MAC address, and the
5747 addresses differ, the value from the environment is used and a
5750 o If neither SROM nor the environment contain a MAC address, an error
5753 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5754 will be programmed into hardware as part of the initialization process. This
5755 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5756 The naming convention is as follows:
5757 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5762 U-Boot is capable of booting (and performing other auxiliary operations on)
5763 images in two formats:
5765 New uImage format (FIT)
5766 -----------------------
5768 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5769 to Flattened Device Tree). It allows the use of images with multiple
5770 components (several kernels, ramdisks, etc.), with contents protected by
5771 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5777 Old image format is based on binary files which can be basically anything,
5778 preceded by a special header; see the definitions in include/image.h for
5779 details; basically, the header defines the following image properties:
5781 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5782 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5783 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5784 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5786 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5787 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5788 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5789 * Compression Type (uncompressed, gzip, bzip2)
5795 The header is marked by a special Magic Number, and both the header
5796 and the data portions of the image are secured against corruption by
5803 Although U-Boot should support any OS or standalone application
5804 easily, the main focus has always been on Linux during the design of
5807 U-Boot includes many features that so far have been part of some
5808 special "boot loader" code within the Linux kernel. Also, any
5809 "initrd" images to be used are no longer part of one big Linux image;
5810 instead, kernel and "initrd" are separate images. This implementation
5811 serves several purposes:
5813 - the same features can be used for other OS or standalone
5814 applications (for instance: using compressed images to reduce the
5815 Flash memory footprint)
5817 - it becomes much easier to port new Linux kernel versions because
5818 lots of low-level, hardware dependent stuff are done by U-Boot
5820 - the same Linux kernel image can now be used with different "initrd"
5821 images; of course this also means that different kernel images can
5822 be run with the same "initrd". This makes testing easier (you don't
5823 have to build a new "zImage.initrd" Linux image when you just
5824 change a file in your "initrd"). Also, a field-upgrade of the
5825 software is easier now.
5831 Porting Linux to U-Boot based systems:
5832 ---------------------------------------
5834 U-Boot cannot save you from doing all the necessary modifications to
5835 configure the Linux device drivers for use with your target hardware
5836 (no, we don't intend to provide a full virtual machine interface to
5839 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5841 Just make sure your machine specific header file (for instance
5842 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5843 Information structure as we define in include/asm-<arch>/u-boot.h,
5844 and make sure that your definition of IMAP_ADDR uses the same value
5845 as your U-Boot configuration in CONFIG_SYS_IMMR.
5847 Note that U-Boot now has a driver model, a unified model for drivers.
5848 If you are adding a new driver, plumb it into driver model. If there
5849 is no uclass available, you are encouraged to create one. See
5853 Configuring the Linux kernel:
5854 -----------------------------
5856 No specific requirements for U-Boot. Make sure you have some root
5857 device (initial ramdisk, NFS) for your target system.
5860 Building a Linux Image:
5861 -----------------------
5863 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5864 not used. If you use recent kernel source, a new build target
5865 "uImage" will exist which automatically builds an image usable by
5866 U-Boot. Most older kernels also have support for a "pImage" target,
5867 which was introduced for our predecessor project PPCBoot and uses a
5868 100% compatible format.
5872 make TQM850L_defconfig
5877 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5878 encapsulate a compressed Linux kernel image with header information,
5879 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5881 * build a standard "vmlinux" kernel image (in ELF binary format):
5883 * convert the kernel into a raw binary image:
5885 ${CROSS_COMPILE}-objcopy -O binary \
5886 -R .note -R .comment \
5887 -S vmlinux linux.bin
5889 * compress the binary image:
5893 * package compressed binary image for U-Boot:
5895 mkimage -A ppc -O linux -T kernel -C gzip \
5896 -a 0 -e 0 -n "Linux Kernel Image" \
5897 -d linux.bin.gz uImage
5900 The "mkimage" tool can also be used to create ramdisk images for use
5901 with U-Boot, either separated from the Linux kernel image, or
5902 combined into one file. "mkimage" encapsulates the images with a 64
5903 byte header containing information about target architecture,
5904 operating system, image type, compression method, entry points, time
5905 stamp, CRC32 checksums, etc.
5907 "mkimage" can be called in two ways: to verify existing images and
5908 print the header information, or to build new images.
5910 In the first form (with "-l" option) mkimage lists the information
5911 contained in the header of an existing U-Boot image; this includes
5912 checksum verification:
5914 tools/mkimage -l image
5915 -l ==> list image header information
5917 The second form (with "-d" option) is used to build a U-Boot image
5918 from a "data file" which is used as image payload:
5920 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5921 -n name -d data_file image
5922 -A ==> set architecture to 'arch'
5923 -O ==> set operating system to 'os'
5924 -T ==> set image type to 'type'
5925 -C ==> set compression type 'comp'
5926 -a ==> set load address to 'addr' (hex)
5927 -e ==> set entry point to 'ep' (hex)
5928 -n ==> set image name to 'name'
5929 -d ==> use image data from 'datafile'
5931 Right now, all Linux kernels for PowerPC systems use the same load
5932 address (0x00000000), but the entry point address depends on the
5935 - 2.2.x kernels have the entry point at 0x0000000C,
5936 - 2.3.x and later kernels have the entry point at 0x00000000.
5938 So a typical call to build a U-Boot image would read:
5940 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5941 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5942 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5943 > examples/uImage.TQM850L
5944 Image Name: 2.4.4 kernel for TQM850L
5945 Created: Wed Jul 19 02:34:59 2000
5946 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5947 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5948 Load Address: 0x00000000
5949 Entry Point: 0x00000000
5951 To verify the contents of the image (or check for corruption):
5953 -> tools/mkimage -l examples/uImage.TQM850L
5954 Image Name: 2.4.4 kernel for TQM850L
5955 Created: Wed Jul 19 02:34:59 2000
5956 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5957 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5958 Load Address: 0x00000000
5959 Entry Point: 0x00000000
5961 NOTE: for embedded systems where boot time is critical you can trade
5962 speed for memory and install an UNCOMPRESSED image instead: this
5963 needs more space in Flash, but boots much faster since it does not
5964 need to be uncompressed:
5966 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5967 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5968 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5969 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5970 > examples/uImage.TQM850L-uncompressed
5971 Image Name: 2.4.4 kernel for TQM850L
5972 Created: Wed Jul 19 02:34:59 2000
5973 Image Type: PowerPC Linux Kernel Image (uncompressed)
5974 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5975 Load Address: 0x00000000
5976 Entry Point: 0x00000000
5979 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5980 when your kernel is intended to use an initial ramdisk:
5982 -> tools/mkimage -n 'Simple Ramdisk Image' \
5983 > -A ppc -O linux -T ramdisk -C gzip \
5984 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5985 Image Name: Simple Ramdisk Image
5986 Created: Wed Jan 12 14:01:50 2000
5987 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5988 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5989 Load Address: 0x00000000
5990 Entry Point: 0x00000000
5992 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5993 option performs the converse operation of the mkimage's second form (the "-d"
5994 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5997 tools/dumpimage -i image -T type -p position data_file
5998 -i ==> extract from the 'image' a specific 'data_file'
5999 -T ==> set image type to 'type'
6000 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6003 Installing a Linux Image:
6004 -------------------------
6006 To downloading a U-Boot image over the serial (console) interface,
6007 you must convert the image to S-Record format:
6009 objcopy -I binary -O srec examples/image examples/image.srec
6011 The 'objcopy' does not understand the information in the U-Boot
6012 image header, so the resulting S-Record file will be relative to
6013 address 0x00000000. To load it to a given address, you need to
6014 specify the target address as 'offset' parameter with the 'loads'
6017 Example: install the image to address 0x40100000 (which on the
6018 TQM8xxL is in the first Flash bank):
6020 => erase 40100000 401FFFFF
6026 ## Ready for S-Record download ...
6027 ~>examples/image.srec
6028 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6030 15989 15990 15991 15992
6031 [file transfer complete]
6033 ## Start Addr = 0x00000000
6036 You can check the success of the download using the 'iminfo' command;
6037 this includes a checksum verification so you can be sure no data
6038 corruption happened:
6042 ## Checking Image at 40100000 ...
6043 Image Name: 2.2.13 for initrd on TQM850L
6044 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6045 Data Size: 335725 Bytes = 327 kB = 0 MB
6046 Load Address: 00000000
6047 Entry Point: 0000000c
6048 Verifying Checksum ... OK
6054 The "bootm" command is used to boot an application that is stored in
6055 memory (RAM or Flash). In case of a Linux kernel image, the contents
6056 of the "bootargs" environment variable is passed to the kernel as
6057 parameters. You can check and modify this variable using the
6058 "printenv" and "setenv" commands:
6061 => printenv bootargs
6062 bootargs=root=/dev/ram
6064 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6066 => printenv bootargs
6067 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6070 ## Booting Linux kernel at 40020000 ...
6071 Image Name: 2.2.13 for NFS on TQM850L
6072 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6073 Data Size: 381681 Bytes = 372 kB = 0 MB
6074 Load Address: 00000000
6075 Entry Point: 0000000c
6076 Verifying Checksum ... OK
6077 Uncompressing Kernel Image ... OK
6078 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
6079 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6080 time_init: decrementer frequency = 187500000/60
6081 Calibrating delay loop... 49.77 BogoMIPS
6082 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6085 If you want to boot a Linux kernel with initial RAM disk, you pass
6086 the memory addresses of both the kernel and the initrd image (PPBCOOT
6087 format!) to the "bootm" command:
6089 => imi 40100000 40200000
6091 ## Checking Image at 40100000 ...
6092 Image Name: 2.2.13 for initrd on TQM850L
6093 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6094 Data Size: 335725 Bytes = 327 kB = 0 MB
6095 Load Address: 00000000
6096 Entry Point: 0000000c
6097 Verifying Checksum ... OK
6099 ## Checking Image at 40200000 ...
6100 Image Name: Simple Ramdisk Image
6101 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6102 Data Size: 566530 Bytes = 553 kB = 0 MB
6103 Load Address: 00000000
6104 Entry Point: 00000000
6105 Verifying Checksum ... OK
6107 => bootm 40100000 40200000
6108 ## Booting Linux kernel at 40100000 ...
6109 Image Name: 2.2.13 for initrd on TQM850L
6110 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6111 Data Size: 335725 Bytes = 327 kB = 0 MB
6112 Load Address: 00000000
6113 Entry Point: 0000000c
6114 Verifying Checksum ... OK
6115 Uncompressing Kernel Image ... OK
6116 ## Loading RAMDisk Image at 40200000 ...
6117 Image Name: Simple Ramdisk Image
6118 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6119 Data Size: 566530 Bytes = 553 kB = 0 MB
6120 Load Address: 00000000
6121 Entry Point: 00000000
6122 Verifying Checksum ... OK
6123 Loading Ramdisk ... OK
6124 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
6125 Boot arguments: root=/dev/ram
6126 time_init: decrementer frequency = 187500000/60
6127 Calibrating delay loop... 49.77 BogoMIPS
6129 RAMDISK: Compressed image found at block 0
6130 VFS: Mounted root (ext2 filesystem).
6134 Boot Linux and pass a flat device tree:
6137 First, U-Boot must be compiled with the appropriate defines. See the section
6138 titled "Linux Kernel Interface" above for a more in depth explanation. The
6139 following is an example of how to start a kernel and pass an updated
6145 oft=oftrees/mpc8540ads.dtb
6146 => tftp $oftaddr $oft
6147 Speed: 1000, full duplex
6149 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6150 Filename 'oftrees/mpc8540ads.dtb'.
6151 Load address: 0x300000
6154 Bytes transferred = 4106 (100a hex)
6155 => tftp $loadaddr $bootfile
6156 Speed: 1000, full duplex
6158 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6160 Load address: 0x200000
6161 Loading:############
6163 Bytes transferred = 1029407 (fb51f hex)
6168 => bootm $loadaddr - $oftaddr
6169 ## Booting image at 00200000 ...
6170 Image Name: Linux-2.6.17-dirty
6171 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6172 Data Size: 1029343 Bytes = 1005.2 kB
6173 Load Address: 00000000
6174 Entry Point: 00000000
6175 Verifying Checksum ... OK
6176 Uncompressing Kernel Image ... OK
6177 Booting using flat device tree at 0x300000
6178 Using MPC85xx ADS machine description
6179 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6183 More About U-Boot Image Types:
6184 ------------------------------
6186 U-Boot supports the following image types:
6188 "Standalone Programs" are directly runnable in the environment
6189 provided by U-Boot; it is expected that (if they behave
6190 well) you can continue to work in U-Boot after return from
6191 the Standalone Program.
6192 "OS Kernel Images" are usually images of some Embedded OS which
6193 will take over control completely. Usually these programs
6194 will install their own set of exception handlers, device
6195 drivers, set up the MMU, etc. - this means, that you cannot
6196 expect to re-enter U-Boot except by resetting the CPU.
6197 "RAMDisk Images" are more or less just data blocks, and their
6198 parameters (address, size) are passed to an OS kernel that is
6200 "Multi-File Images" contain several images, typically an OS
6201 (Linux) kernel image and one or more data images like
6202 RAMDisks. This construct is useful for instance when you want
6203 to boot over the network using BOOTP etc., where the boot
6204 server provides just a single image file, but you want to get
6205 for instance an OS kernel and a RAMDisk image.
6207 "Multi-File Images" start with a list of image sizes, each
6208 image size (in bytes) specified by an "uint32_t" in network
6209 byte order. This list is terminated by an "(uint32_t)0".
6210 Immediately after the terminating 0 follow the images, one by
6211 one, all aligned on "uint32_t" boundaries (size rounded up to
6212 a multiple of 4 bytes).
6214 "Firmware Images" are binary images containing firmware (like
6215 U-Boot or FPGA images) which usually will be programmed to
6218 "Script files" are command sequences that will be executed by
6219 U-Boot's command interpreter; this feature is especially
6220 useful when you configure U-Boot to use a real shell (hush)
6221 as command interpreter.
6223 Booting the Linux zImage:
6224 -------------------------
6226 On some platforms, it's possible to boot Linux zImage. This is done
6227 using the "bootz" command. The syntax of "bootz" command is the same
6228 as the syntax of "bootm" command.
6230 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6231 kernel with raw initrd images. The syntax is slightly different, the
6232 address of the initrd must be augmented by it's size, in the following
6233 format: "<initrd addres>:<initrd size>".
6239 One of the features of U-Boot is that you can dynamically load and
6240 run "standalone" applications, which can use some resources of
6241 U-Boot like console I/O functions or interrupt services.
6243 Two simple examples are included with the sources:
6248 'examples/hello_world.c' contains a small "Hello World" Demo
6249 application; it is automatically compiled when you build U-Boot.
6250 It's configured to run at address 0x00040004, so you can play with it
6254 ## Ready for S-Record download ...
6255 ~>examples/hello_world.srec
6256 1 2 3 4 5 6 7 8 9 10 11 ...
6257 [file transfer complete]
6259 ## Start Addr = 0x00040004
6261 => go 40004 Hello World! This is a test.
6262 ## Starting application at 0x00040004 ...
6273 Hit any key to exit ...
6275 ## Application terminated, rc = 0x0
6277 Another example, which demonstrates how to register a CPM interrupt
6278 handler with the U-Boot code, can be found in 'examples/timer.c'.
6279 Here, a CPM timer is set up to generate an interrupt every second.
6280 The interrupt service routine is trivial, just printing a '.'
6281 character, but this is just a demo program. The application can be
6282 controlled by the following keys:
6284 ? - print current values og the CPM Timer registers
6285 b - enable interrupts and start timer
6286 e - stop timer and disable interrupts
6287 q - quit application
6290 ## Ready for S-Record download ...
6291 ~>examples/timer.srec
6292 1 2 3 4 5 6 7 8 9 10 11 ...
6293 [file transfer complete]
6295 ## Start Addr = 0x00040004
6298 ## Starting application at 0x00040004 ...
6301 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6304 [q, b, e, ?] Set interval 1000000 us
6307 [q, b, e, ?] ........
6308 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6311 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6314 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6317 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6319 [q, b, e, ?] ...Stopping timer
6321 [q, b, e, ?] ## Application terminated, rc = 0x0
6327 Over time, many people have reported problems when trying to use the
6328 "minicom" terminal emulation program for serial download. I (wd)
6329 consider minicom to be broken, and recommend not to use it. Under
6330 Unix, I recommend to use C-Kermit for general purpose use (and
6331 especially for kermit binary protocol download ("loadb" command), and
6332 use "cu" for S-Record download ("loads" command). See
6333 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6334 for help with kermit.
6337 Nevertheless, if you absolutely want to use it try adding this
6338 configuration to your "File transfer protocols" section:
6340 Name Program Name U/D FullScr IO-Red. Multi
6341 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6342 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6348 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6349 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6351 Building requires a cross environment; it is known to work on
6352 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6353 need gmake since the Makefiles are not compatible with BSD make).
6354 Note that the cross-powerpc package does not install include files;
6355 attempting to build U-Boot will fail because <machine/ansi.h> is
6356 missing. This file has to be installed and patched manually:
6358 # cd /usr/pkg/cross/powerpc-netbsd/include
6360 # ln -s powerpc machine
6361 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6362 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6364 Native builds *don't* work due to incompatibilities between native
6365 and U-Boot include files.
6367 Booting assumes that (the first part of) the image booted is a
6368 stage-2 loader which in turn loads and then invokes the kernel
6369 proper. Loader sources will eventually appear in the NetBSD source
6370 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6371 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6374 Implementation Internals:
6375 =========================
6377 The following is not intended to be a complete description of every
6378 implementation detail. However, it should help to understand the
6379 inner workings of U-Boot and make it easier to port it to custom
6383 Initial Stack, Global Data:
6384 ---------------------------
6386 The implementation of U-Boot is complicated by the fact that U-Boot
6387 starts running out of ROM (flash memory), usually without access to
6388 system RAM (because the memory controller is not initialized yet).
6389 This means that we don't have writable Data or BSS segments, and BSS
6390 is not initialized as zero. To be able to get a C environment working
6391 at all, we have to allocate at least a minimal stack. Implementation
6392 options for this are defined and restricted by the CPU used: Some CPU
6393 models provide on-chip memory (like the IMMR area on MPC8xx and
6394 MPC826x processors), on others (parts of) the data cache can be
6395 locked as (mis-) used as memory, etc.
6397 Chris Hallinan posted a good summary of these issues to the
6398 U-Boot mailing list:
6400 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6401 From: "Chris Hallinan" <clh@net1plus.com>
6402 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6405 Correct me if I'm wrong, folks, but the way I understand it
6406 is this: Using DCACHE as initial RAM for Stack, etc, does not
6407 require any physical RAM backing up the cache. The cleverness
6408 is that the cache is being used as a temporary supply of
6409 necessary storage before the SDRAM controller is setup. It's
6410 beyond the scope of this list to explain the details, but you
6411 can see how this works by studying the cache architecture and
6412 operation in the architecture and processor-specific manuals.
6414 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6415 is another option for the system designer to use as an
6416 initial stack/RAM area prior to SDRAM being available. Either
6417 option should work for you. Using CS 4 should be fine if your
6418 board designers haven't used it for something that would
6419 cause you grief during the initial boot! It is frequently not
6422 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6423 with your processor/board/system design. The default value
6424 you will find in any recent u-boot distribution in
6425 walnut.h should work for you. I'd set it to a value larger
6426 than your SDRAM module. If you have a 64MB SDRAM module, set
6427 it above 400_0000. Just make sure your board has no resources
6428 that are supposed to respond to that address! That code in
6429 start.S has been around a while and should work as is when
6430 you get the config right.
6435 It is essential to remember this, since it has some impact on the C
6436 code for the initialization procedures:
6438 * Initialized global data (data segment) is read-only. Do not attempt
6441 * Do not use any uninitialized global data (or implicitly initialized
6442 as zero data - BSS segment) at all - this is undefined, initiali-
6443 zation is performed later (when relocating to RAM).
6445 * Stack space is very limited. Avoid big data buffers or things like
6448 Having only the stack as writable memory limits means we cannot use
6449 normal global data to share information between the code. But it
6450 turned out that the implementation of U-Boot can be greatly
6451 simplified by making a global data structure (gd_t) available to all
6452 functions. We could pass a pointer to this data as argument to _all_
6453 functions, but this would bloat the code. Instead we use a feature of
6454 the GCC compiler (Global Register Variables) to share the data: we
6455 place a pointer (gd) to the global data into a register which we
6456 reserve for this purpose.
6458 When choosing a register for such a purpose we are restricted by the
6459 relevant (E)ABI specifications for the current architecture, and by
6460 GCC's implementation.
6462 For PowerPC, the following registers have specific use:
6464 R2: reserved for system use
6465 R3-R4: parameter passing and return values
6466 R5-R10: parameter passing
6467 R13: small data area pointer
6471 (U-Boot also uses R12 as internal GOT pointer. r12
6472 is a volatile register so r12 needs to be reset when
6473 going back and forth between asm and C)
6475 ==> U-Boot will use R2 to hold a pointer to the global data
6477 Note: on PPC, we could use a static initializer (since the
6478 address of the global data structure is known at compile time),
6479 but it turned out that reserving a register results in somewhat
6480 smaller code - although the code savings are not that big (on
6481 average for all boards 752 bytes for the whole U-Boot image,
6482 624 text + 127 data).
6484 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6485 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6487 ==> U-Boot will use P3 to hold a pointer to the global data
6489 On ARM, the following registers are used:
6491 R0: function argument word/integer result
6492 R1-R3: function argument word
6493 R9: platform specific
6494 R10: stack limit (used only if stack checking is enabled)
6495 R11: argument (frame) pointer
6496 R12: temporary workspace
6499 R15: program counter
6501 ==> U-Boot will use R9 to hold a pointer to the global data
6503 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6505 On Nios II, the ABI is documented here:
6506 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6508 ==> U-Boot will use gp to hold a pointer to the global data
6510 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6511 to access small data sections, so gp is free.
6513 On NDS32, the following registers are used:
6515 R0-R1: argument/return
6517 R15: temporary register for assembler
6518 R16: trampoline register
6519 R28: frame pointer (FP)
6520 R29: global pointer (GP)
6521 R30: link register (LP)
6522 R31: stack pointer (SP)
6523 PC: program counter (PC)
6525 ==> U-Boot will use R10 to hold a pointer to the global data
6527 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6528 or current versions of GCC may "optimize" the code too much.
6533 U-Boot runs in system state and uses physical addresses, i.e. the
6534 MMU is not used either for address mapping nor for memory protection.
6536 The available memory is mapped to fixed addresses using the memory
6537 controller. In this process, a contiguous block is formed for each
6538 memory type (Flash, SDRAM, SRAM), even when it consists of several
6539 physical memory banks.
6541 U-Boot is installed in the first 128 kB of the first Flash bank (on
6542 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6543 booting and sizing and initializing DRAM, the code relocates itself
6544 to the upper end of DRAM. Immediately below the U-Boot code some
6545 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6546 configuration setting]. Below that, a structure with global Board
6547 Info data is placed, followed by the stack (growing downward).
6549 Additionally, some exception handler code is copied to the low 8 kB
6550 of DRAM (0x00000000 ... 0x00001FFF).
6552 So a typical memory configuration with 16 MB of DRAM could look like
6555 0x0000 0000 Exception Vector code
6558 0x0000 2000 Free for Application Use
6564 0x00FB FF20 Monitor Stack (Growing downward)
6565 0x00FB FFAC Board Info Data and permanent copy of global data
6566 0x00FC 0000 Malloc Arena
6569 0x00FE 0000 RAM Copy of Monitor Code
6570 ... eventually: LCD or video framebuffer
6571 ... eventually: pRAM (Protected RAM - unchanged by reset)
6572 0x00FF FFFF [End of RAM]
6575 System Initialization:
6576 ----------------------
6578 In the reset configuration, U-Boot starts at the reset entry point
6579 (on most PowerPC systems at address 0x00000100). Because of the reset
6580 configuration for CS0# this is a mirror of the on board Flash memory.
6581 To be able to re-map memory U-Boot then jumps to its link address.
6582 To be able to implement the initialization code in C, a (small!)
6583 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6584 which provide such a feature like MPC8xx or MPC8260), or in a locked
6585 part of the data cache. After that, U-Boot initializes the CPU core,
6586 the caches and the SIU.
6588 Next, all (potentially) available memory banks are mapped using a
6589 preliminary mapping. For example, we put them on 512 MB boundaries
6590 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6591 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6592 programmed for SDRAM access. Using the temporary configuration, a
6593 simple memory test is run that determines the size of the SDRAM
6596 When there is more than one SDRAM bank, and the banks are of
6597 different size, the largest is mapped first. For equal size, the first
6598 bank (CS2#) is mapped first. The first mapping is always for address
6599 0x00000000, with any additional banks following immediately to create
6600 contiguous memory starting from 0.
6602 Then, the monitor installs itself at the upper end of the SDRAM area
6603 and allocates memory for use by malloc() and for the global Board
6604 Info data; also, the exception vector code is copied to the low RAM
6605 pages, and the final stack is set up.
6607 Only after this relocation will you have a "normal" C environment;
6608 until that you are restricted in several ways, mostly because you are
6609 running from ROM, and because the code will have to be relocated to a
6613 U-Boot Porting Guide:
6614 ----------------------
6616 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6620 int main(int argc, char *argv[])
6622 sighandler_t no_more_time;
6624 signal(SIGALRM, no_more_time);
6625 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6627 if (available_money > available_manpower) {
6628 Pay consultant to port U-Boot;
6632 Download latest U-Boot source;
6634 Subscribe to u-boot mailing list;
6637 email("Hi, I am new to U-Boot, how do I get started?");
6640 Read the README file in the top level directory;
6641 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6642 Read applicable doc/*.README;
6643 Read the source, Luke;
6644 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6647 if (available_money > toLocalCurrency ($2500))
6650 Add a lot of aggravation and time;
6652 if (a similar board exists) { /* hopefully... */
6653 cp -a board/<similar> board/<myboard>
6654 cp include/configs/<similar>.h include/configs/<myboard>.h
6656 Create your own board support subdirectory;
6657 Create your own board include/configs/<myboard>.h file;
6659 Edit new board/<myboard> files
6660 Edit new include/configs/<myboard>.h
6665 Add / modify source code;
6669 email("Hi, I am having problems...");
6671 Send patch file to the U-Boot email list;
6672 if (reasonable critiques)
6673 Incorporate improvements from email list code review;
6675 Defend code as written;
6681 void no_more_time (int sig)
6690 All contributions to U-Boot should conform to the Linux kernel
6691 coding style; see the file "Documentation/CodingStyle" and the script
6692 "scripts/Lindent" in your Linux kernel source directory.
6694 Source files originating from a different project (for example the
6695 MTD subsystem) are generally exempt from these guidelines and are not
6696 reformatted to ease subsequent migration to newer versions of those
6699 Please note that U-Boot is implemented in C (and to some small parts in
6700 Assembler); no C++ is used, so please do not use C++ style comments (//)
6703 Please also stick to the following formatting rules:
6704 - remove any trailing white space
6705 - use TAB characters for indentation and vertical alignment, not spaces
6706 - make sure NOT to use DOS '\r\n' line feeds
6707 - do not add more than 2 consecutive empty lines to source files
6708 - do not add trailing empty lines to source files
6710 Submissions which do not conform to the standards may be returned
6711 with a request to reformat the changes.
6717 Since the number of patches for U-Boot is growing, we need to
6718 establish some rules. Submissions which do not conform to these rules
6719 may be rejected, even when they contain important and valuable stuff.
6721 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6723 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6724 see http://lists.denx.de/mailman/listinfo/u-boot
6726 When you send a patch, please include the following information with
6729 * For bug fixes: a description of the bug and how your patch fixes
6730 this bug. Please try to include a way of demonstrating that the
6731 patch actually fixes something.
6733 * For new features: a description of the feature and your
6736 * A CHANGELOG entry as plaintext (separate from the patch)
6738 * For major contributions, your entry to the CREDITS file
6740 * When you add support for a new board, don't forget to add a
6741 maintainer e-mail address to the boards.cfg file, too.
6743 * If your patch adds new configuration options, don't forget to
6744 document these in the README file.
6746 * The patch itself. If you are using git (which is *strongly*
6747 recommended) you can easily generate the patch using the
6748 "git format-patch". If you then use "git send-email" to send it to
6749 the U-Boot mailing list, you will avoid most of the common problems
6750 with some other mail clients.
6752 If you cannot use git, use "diff -purN OLD NEW". If your version of
6753 diff does not support these options, then get the latest version of
6756 The current directory when running this command shall be the parent
6757 directory of the U-Boot source tree (i. e. please make sure that
6758 your patch includes sufficient directory information for the
6761 We prefer patches as plain text. MIME attachments are discouraged,
6762 and compressed attachments must not be used.
6764 * If one logical set of modifications affects or creates several
6765 files, all these changes shall be submitted in a SINGLE patch file.
6767 * Changesets that contain different, unrelated modifications shall be
6768 submitted as SEPARATE patches, one patch per changeset.
6773 * Before sending the patch, run the MAKEALL script on your patched
6774 source tree and make sure that no errors or warnings are reported
6775 for any of the boards.
6777 * Keep your modifications to the necessary minimum: A patch
6778 containing several unrelated changes or arbitrary reformats will be
6779 returned with a request to re-formatting / split it.
6781 * If you modify existing code, make sure that your new code does not
6782 add to the memory footprint of the code ;-) Small is beautiful!
6783 When adding new features, these should compile conditionally only
6784 (using #ifdef), and the resulting code with the new feature
6785 disabled must not need more memory than the old code without your
6788 * Remember that there is a size limit of 100 kB per message on the
6789 u-boot mailing list. Bigger patches will be moderated. If they are
6790 reasonable and not too big, they will be acknowledged. But patches
6791 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob