2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_798870
707 CONFIG_TEGRA_SUPPORT_NON_SECURE
709 Support executing U-Boot in non-secure (NS) mode. Certain
710 impossible actions will be skipped if the CPU is in NS mode,
711 such as ARM architectural timer initialization.
714 Driver model is a new framework for devices in U-Boot
715 introduced in early 2014. U-Boot is being progressively
716 moved over to this. It offers a consistent device structure,
717 supports grouping devices into classes and has built-in
718 handling of platform data and device tree.
720 To enable transition to driver model in a relatively
721 painful fashion, each subsystem can be independently
722 switched between the legacy/ad-hoc approach and the new
723 driver model using the options below. Also, many uclass
724 interfaces include compatibility features which may be
725 removed once the conversion of that subsystem is complete.
726 As a result, the API provided by the subsystem may in fact
727 not change with driver model.
729 See doc/driver-model/README.txt for more information.
733 Enable driver model. This brings in the core support,
734 including scanning of platform data on start-up. If
735 CONFIG_OF_CONTROL is enabled, the device tree will be
736 scanned also when available.
740 Enable driver model test commands. These allow you to print
741 out the driver model tree and the uclasses.
745 Enable some demo devices and the 'demo' command. These are
746 really only useful for playing around while trying to
747 understand driver model in sandbox.
751 Enable driver model in SPL. You will need to provide a
752 suitable malloc() implementation. If you are not using the
753 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
754 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
755 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
756 In most cases driver model will only allocate a few uclasses
757 and devices in SPL, so 1KB should be enable. See
758 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
763 Enable driver model for serial. This replaces
764 drivers/serial/serial.c with the serial uclass, which
765 implements serial_putc() etc. The uclass interface is
766 defined in include/serial.h.
770 Enable driver model for GPIO access. The standard GPIO
771 interface (gpio_get_value(), etc.) is then implemented by
772 the GPIO uclass. Drivers provide methods to query the
773 particular GPIOs that they provide. The uclass interface
774 is defined in include/asm-generic/gpio.h.
778 Enable driver model for SPI. The SPI slave interface
779 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
780 the SPI uclass. Drivers provide methods to access the SPI
781 buses that they control. The uclass interface is defined in
782 include/spi.h. The existing spi_slave structure is attached
783 as 'parent data' to every slave on each bus. Slaves
784 typically use driver-private data instead of extending the
789 Enable driver model for SPI flash. This SPI flash interface
790 (spi_flash_probe(), spi_flash_write(), etc.) is then
791 implemented by the SPI flash uclass. There is one standard
792 SPI flash driver which knows how to probe most chips
793 supported by U-Boot. The uclass interface is defined in
794 include/spi_flash.h, but is currently fully compatible
795 with the old interface to avoid confusion and duplication
796 during the transition parent. SPI and SPI flash must be
797 enabled together (it is not possible to use driver model
798 for one and not the other).
802 Enable driver model for the Chrome OS EC interface. This
803 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
804 but otherwise makes few changes. Since cros_ec also supports
805 I2C and LPC (which don't support driver model yet), a full
806 conversion is not yet possible.
809 ** Code size options: The following options are enabled by
810 default except in SPL. Enable them explicitly to get these
815 Enable the dm_warn() function. This can use up quite a bit
816 of space for its strings.
820 Enable registering a serial device with the stdio library.
822 CONFIG_DM_DEVICE_REMOVE
824 Enable removing of devices.
826 - Linux Kernel Interface:
829 U-Boot stores all clock information in Hz
830 internally. For binary compatibility with older Linux
831 kernels (which expect the clocks passed in the
832 bd_info data to be in MHz) the environment variable
833 "clocks_in_mhz" can be defined so that U-Boot
834 converts clock data to MHZ before passing it to the
836 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
837 "clocks_in_mhz=1" is automatically included in the
840 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
842 When transferring memsize parameter to Linux, some versions
843 expect it to be in bytes, others in MB.
844 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
848 New kernel versions are expecting firmware settings to be
849 passed using flattened device trees (based on open firmware
853 * New libfdt-based support
854 * Adds the "fdt" command
855 * The bootm command automatically updates the fdt
857 OF_CPU - The proper name of the cpus node (only required for
858 MPC512X and MPC5xxx based boards).
859 OF_SOC - The proper name of the soc node (only required for
860 MPC512X and MPC5xxx based boards).
861 OF_TBCLK - The timebase frequency.
862 OF_STDOUT_PATH - The path to the console device
864 boards with QUICC Engines require OF_QE to set UCC MAC
867 CONFIG_OF_BOARD_SETUP
869 Board code has addition modification that it wants to make
870 to the flat device tree before handing it off to the kernel
872 CONFIG_OF_SYSTEM_SETUP
874 Other code has addition modification that it wants to make
875 to the flat device tree before handing it off to the kernel.
876 This causes ft_system_setup() to be called before booting
881 This define fills in the correct boot CPU in the boot
882 param header, the default value is zero if undefined.
886 U-Boot can detect if an IDE device is present or not.
887 If not, and this new config option is activated, U-Boot
888 removes the ATA node from the DTS before booting Linux,
889 so the Linux IDE driver does not probe the device and
890 crash. This is needed for buggy hardware (uc101) where
891 no pull down resistor is connected to the signal IDE5V_DD7.
893 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
895 This setting is mandatory for all boards that have only one
896 machine type and must be used to specify the machine type
897 number as it appears in the ARM machine registry
898 (see http://www.arm.linux.org.uk/developer/machines/).
899 Only boards that have multiple machine types supported
900 in a single configuration file and the machine type is
901 runtime discoverable, do not have to use this setting.
903 - vxWorks boot parameters:
905 bootvx constructs a valid bootline using the following
906 environments variables: bootfile, ipaddr, serverip, hostname.
907 It loads the vxWorks image pointed bootfile.
909 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
910 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
911 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
912 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
914 CONFIG_SYS_VXWORKS_ADD_PARAMS
916 Add it at the end of the bootline. E.g "u=username pw=secret"
918 Note: If a "bootargs" environment is defined, it will overwride
919 the defaults discussed just above.
921 - Cache Configuration:
922 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
923 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
924 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
926 - Cache Configuration for ARM:
927 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
929 CONFIG_SYS_PL310_BASE - Physical base address of PL310
930 controller register space
935 Define this if you want support for Amba PrimeCell PL010 UARTs.
939 Define this if you want support for Amba PrimeCell PL011 UARTs.
943 If you have Amba PrimeCell PL011 UARTs, set this variable to
944 the clock speed of the UARTs.
948 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
949 define this to a list of base addresses for each (supported)
950 port. See e.g. include/configs/versatile.h
952 CONFIG_PL011_SERIAL_RLCR
954 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
955 have separate receive and transmit line control registers. Set
956 this variable to initialize the extra register.
958 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
960 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
961 boot loader that has already initialized the UART. Define this
962 variable to flush the UART at init time.
964 CONFIG_SERIAL_HW_FLOW_CONTROL
966 Define this variable to enable hw flow control in serial driver.
967 Current user of this option is drivers/serial/nsl16550.c driver
970 Depending on board, define exactly one serial port
971 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
972 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
973 console by defining CONFIG_8xx_CONS_NONE
975 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
976 port routines must be defined elsewhere
977 (i.e. serial_init(), serial_getc(), ...)
980 Enables console device for a color framebuffer. Needs following
981 defines (cf. smiLynxEM, i8042)
982 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
984 VIDEO_HW_RECTFILL graphic chip supports
987 VIDEO_HW_BITBLT graphic chip supports
988 bit-blit (cf. smiLynxEM)
989 VIDEO_VISIBLE_COLS visible pixel columns
991 VIDEO_VISIBLE_ROWS visible pixel rows
992 VIDEO_PIXEL_SIZE bytes per pixel
993 VIDEO_DATA_FORMAT graphic data format
994 (0-5, cf. cfb_console.c)
995 VIDEO_FB_ADRS framebuffer address
996 VIDEO_KBD_INIT_FCT keyboard int fct
997 (i.e. i8042_kbd_init())
998 VIDEO_TSTC_FCT test char fct
1000 VIDEO_GETC_FCT get char fct
1002 CONFIG_CONSOLE_CURSOR cursor drawing on/off
1003 (requires blink timer
1005 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1006 CONFIG_CONSOLE_TIME display time/date info in
1008 (requires CONFIG_CMD_DATE)
1009 CONFIG_VIDEO_LOGO display Linux logo in
1011 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1012 linux_logo.h for logo.
1013 Requires CONFIG_VIDEO_LOGO
1014 CONFIG_CONSOLE_EXTRA_INFO
1015 additional board info beside
1018 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1019 a limited number of ANSI escape sequences (cursor control,
1020 erase functions and limited graphics rendition control).
1022 When CONFIG_CFB_CONSOLE is defined, video console is
1023 default i/o. Serial console can be forced with
1024 environment 'console=serial'.
1026 When CONFIG_SILENT_CONSOLE is defined, all console
1027 messages (by U-Boot and Linux!) can be silenced with
1028 the "silent" environment variable. See
1029 doc/README.silent for more information.
1031 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1033 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1037 CONFIG_BAUDRATE - in bps
1038 Select one of the baudrates listed in
1039 CONFIG_SYS_BAUDRATE_TABLE, see below.
1040 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1042 - Console Rx buffer length
1043 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1044 the maximum receive buffer length for the SMC.
1045 This option is actual only for 82xx and 8xx possible.
1046 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1047 must be defined, to setup the maximum idle timeout for
1050 - Pre-Console Buffer:
1051 Prior to the console being initialised (i.e. serial UART
1052 initialised etc) all console output is silently discarded.
1053 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1054 buffer any console messages prior to the console being
1055 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1056 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1057 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1058 bytes are output before the console is initialised, the
1059 earlier bytes are discarded.
1061 Note that when printing the buffer a copy is made on the
1062 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
1064 'Sane' compilers will generate smaller code if
1065 CONFIG_PRE_CON_BUF_SZ is a power of 2
1067 - Safe printf() functions
1068 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1069 the printf() functions. These are defined in
1070 include/vsprintf.h and include snprintf(), vsnprintf() and
1071 so on. Code size increase is approximately 300-500 bytes.
1072 If this option is not given then these functions will
1073 silently discard their buffer size argument - this means
1074 you are not getting any overflow checking in this case.
1076 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1077 Delay before automatically booting the default image;
1078 set to -1 to disable autoboot.
1079 set to -2 to autoboot with no delay and not check for abort
1080 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1082 See doc/README.autoboot for these options that
1083 work with CONFIG_BOOTDELAY. None are required.
1084 CONFIG_BOOT_RETRY_TIME
1085 CONFIG_BOOT_RETRY_MIN
1086 CONFIG_AUTOBOOT_KEYED
1087 CONFIG_AUTOBOOT_PROMPT
1088 CONFIG_AUTOBOOT_DELAY_STR
1089 CONFIG_AUTOBOOT_STOP_STR
1090 CONFIG_AUTOBOOT_DELAY_STR2
1091 CONFIG_AUTOBOOT_STOP_STR2
1092 CONFIG_ZERO_BOOTDELAY_CHECK
1093 CONFIG_RESET_TO_RETRY
1097 Only needed when CONFIG_BOOTDELAY is enabled;
1098 define a command string that is automatically executed
1099 when no character is read on the console interface
1100 within "Boot Delay" after reset.
1103 This can be used to pass arguments to the bootm
1104 command. The value of CONFIG_BOOTARGS goes into the
1105 environment value "bootargs".
1107 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1108 The value of these goes into the environment as
1109 "ramboot" and "nfsboot" respectively, and can be used
1110 as a convenience, when switching between booting from
1114 CONFIG_BOOTCOUNT_LIMIT
1115 Implements a mechanism for detecting a repeating reboot
1117 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1119 CONFIG_BOOTCOUNT_ENV
1120 If no softreset save registers are found on the hardware
1121 "bootcount" is stored in the environment. To prevent a
1122 saveenv on all reboots, the environment variable
1123 "upgrade_available" is used. If "upgrade_available" is
1124 0, "bootcount" is always 0, if "upgrade_available" is
1125 1 "bootcount" is incremented in the environment.
1126 So the Userspace Applikation must set the "upgrade_available"
1127 and "bootcount" variable to 0, if a boot was successfully.
1129 - Pre-Boot Commands:
1132 When this option is #defined, the existence of the
1133 environment variable "preboot" will be checked
1134 immediately before starting the CONFIG_BOOTDELAY
1135 countdown and/or running the auto-boot command resp.
1136 entering interactive mode.
1138 This feature is especially useful when "preboot" is
1139 automatically generated or modified. For an example
1140 see the LWMON board specific code: here "preboot" is
1141 modified when the user holds down a certain
1142 combination of keys on the (special) keyboard when
1145 - Serial Download Echo Mode:
1147 If defined to 1, all characters received during a
1148 serial download (using the "loads" command) are
1149 echoed back. This might be needed by some terminal
1150 emulations (like "cu"), but may as well just take
1151 time on others. This setting #define's the initial
1152 value of the "loads_echo" environment variable.
1154 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1155 CONFIG_KGDB_BAUDRATE
1156 Select one of the baudrates listed in
1157 CONFIG_SYS_BAUDRATE_TABLE, see below.
1159 - Monitor Functions:
1160 Monitor commands can be included or excluded
1161 from the build by using the #include files
1162 <config_cmd_all.h> and #undef'ing unwanted
1163 commands, or using <config_cmd_default.h>
1164 and augmenting with additional #define's
1165 for wanted commands.
1167 The default command configuration includes all commands
1168 except those marked below with a "*".
1170 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1171 CONFIG_CMD_ASKENV * ask for env variable
1172 CONFIG_CMD_BDI bdinfo
1173 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1174 CONFIG_CMD_BMP * BMP support
1175 CONFIG_CMD_BSP * Board specific commands
1176 CONFIG_CMD_BOOTD bootd
1177 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1178 CONFIG_CMD_CACHE * icache, dcache
1179 CONFIG_CMD_CLK * clock command support
1180 CONFIG_CMD_CONSOLE coninfo
1181 CONFIG_CMD_CRC32 * crc32
1182 CONFIG_CMD_DATE * support for RTC, date/time...
1183 CONFIG_CMD_DHCP * DHCP support
1184 CONFIG_CMD_DIAG * Diagnostics
1185 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1186 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1187 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1188 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1189 CONFIG_CMD_DTT * Digital Therm and Thermostat
1190 CONFIG_CMD_ECHO echo arguments
1191 CONFIG_CMD_EDITENV edit env variable
1192 CONFIG_CMD_EEPROM * EEPROM read/write support
1193 CONFIG_CMD_ELF * bootelf, bootvx
1194 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1195 CONFIG_CMD_ENV_FLAGS * display details about env flags
1196 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1197 CONFIG_CMD_EXPORTENV * export the environment
1198 CONFIG_CMD_EXT2 * ext2 command support
1199 CONFIG_CMD_EXT4 * ext4 command support
1200 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1201 that work for multiple fs types
1202 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1203 CONFIG_CMD_SAVEENV saveenv
1204 CONFIG_CMD_FDC * Floppy Disk Support
1205 CONFIG_CMD_FAT * FAT command support
1206 CONFIG_CMD_FLASH flinfo, erase, protect
1207 CONFIG_CMD_FPGA FPGA device initialization support
1208 CONFIG_CMD_FUSE * Device fuse support
1209 CONFIG_CMD_GETTIME * Get time since boot
1210 CONFIG_CMD_GO * the 'go' command (exec code)
1211 CONFIG_CMD_GREPENV * search environment
1212 CONFIG_CMD_HASH * calculate hash / digest
1213 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1214 CONFIG_CMD_I2C * I2C serial bus support
1215 CONFIG_CMD_IDE * IDE harddisk support
1216 CONFIG_CMD_IMI iminfo
1217 CONFIG_CMD_IMLS List all images found in NOR flash
1218 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1219 CONFIG_CMD_IMMAP * IMMR dump support
1220 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1221 CONFIG_CMD_IMPORTENV * import an environment
1222 CONFIG_CMD_INI * import data from an ini file into the env
1223 CONFIG_CMD_IRQ * irqinfo
1224 CONFIG_CMD_ITEST Integer/string test of 2 values
1225 CONFIG_CMD_JFFS2 * JFFS2 Support
1226 CONFIG_CMD_KGDB * kgdb
1227 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1228 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1230 CONFIG_CMD_LOADB loadb
1231 CONFIG_CMD_LOADS loads
1232 CONFIG_CMD_MD5SUM * print md5 message digest
1233 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1234 CONFIG_CMD_MEMINFO * Display detailed memory information
1235 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1237 CONFIG_CMD_MEMTEST * mtest
1238 CONFIG_CMD_MISC Misc functions like sleep etc
1239 CONFIG_CMD_MMC * MMC memory mapped support
1240 CONFIG_CMD_MII * MII utility commands
1241 CONFIG_CMD_MTDPARTS * MTD partition support
1242 CONFIG_CMD_NAND * NAND support
1243 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1244 CONFIG_CMD_NFS NFS support
1245 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1246 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1247 CONFIG_CMD_PCI * pciinfo
1248 CONFIG_CMD_PCMCIA * PCMCIA support
1249 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1251 CONFIG_CMD_PORTIO * Port I/O
1252 CONFIG_CMD_READ * Read raw data from partition
1253 CONFIG_CMD_REGINFO * Register dump
1254 CONFIG_CMD_RUN run command in env variable
1255 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1256 CONFIG_CMD_SAVES * save S record dump
1257 CONFIG_CMD_SCSI * SCSI Support
1258 CONFIG_CMD_SDRAM * print SDRAM configuration information
1259 (requires CONFIG_CMD_I2C)
1260 CONFIG_CMD_SETGETDCR Support for DCR Register access
1262 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1263 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1264 (requires CONFIG_CMD_MEMORY)
1265 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1266 CONFIG_CMD_SOURCE "source" command Support
1267 CONFIG_CMD_SPI * SPI serial bus support
1268 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1269 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1270 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1271 CONFIG_CMD_TIMER * access to the system tick timer
1272 CONFIG_CMD_USB * USB support
1273 CONFIG_CMD_CDP * Cisco Discover Protocol support
1274 CONFIG_CMD_MFSL * Microblaze FSL support
1275 CONFIG_CMD_XIMG Load part of Multi Image
1276 CONFIG_CMD_UUID * Generate random UUID or GUID string
1278 EXAMPLE: If you want all functions except of network
1279 support you can write:
1281 #include "config_cmd_all.h"
1282 #undef CONFIG_CMD_NET
1285 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1287 Note: Don't enable the "icache" and "dcache" commands
1288 (configuration option CONFIG_CMD_CACHE) unless you know
1289 what you (and your U-Boot users) are doing. Data
1290 cache cannot be enabled on systems like the 8xx or
1291 8260 (where accesses to the IMMR region must be
1292 uncached), and it cannot be disabled on all other
1293 systems where we (mis-) use the data cache to hold an
1294 initial stack and some data.
1297 XXX - this list needs to get updated!
1299 - Regular expression support:
1301 If this variable is defined, U-Boot is linked against
1302 the SLRE (Super Light Regular Expression) library,
1303 which adds regex support to some commands, as for
1304 example "env grep" and "setexpr".
1308 If this variable is defined, U-Boot will use a device tree
1309 to configure its devices, instead of relying on statically
1310 compiled #defines in the board file. This option is
1311 experimental and only available on a few boards. The device
1312 tree is available in the global data as gd->fdt_blob.
1314 U-Boot needs to get its device tree from somewhere. This can
1315 be done using one of the two options below:
1318 If this variable is defined, U-Boot will embed a device tree
1319 binary in its image. This device tree file should be in the
1320 board directory and called <soc>-<board>.dts. The binary file
1321 is then picked up in board_init_f() and made available through
1322 the global data structure as gd->blob.
1325 If this variable is defined, U-Boot will build a device tree
1326 binary. It will be called u-boot.dtb. Architecture-specific
1327 code will locate it at run-time. Generally this works by:
1329 cat u-boot.bin u-boot.dtb >image.bin
1331 and in fact, U-Boot does this for you, creating a file called
1332 u-boot-dtb.bin which is useful in the common case. You can
1333 still use the individual files if you need something more
1338 If this variable is defined, it enables watchdog
1339 support for the SoC. There must be support in the SoC
1340 specific code for a watchdog. For the 8xx and 8260
1341 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1342 register. When supported for a specific SoC is
1343 available, then no further board specific code should
1344 be needed to use it.
1347 When using a watchdog circuitry external to the used
1348 SoC, then define this variable and provide board
1349 specific code for the "hw_watchdog_reset" function.
1351 CONFIG_AT91_HW_WDT_TIMEOUT
1352 specify the timeout in seconds. default 2 seconds.
1355 CONFIG_VERSION_VARIABLE
1356 If this variable is defined, an environment variable
1357 named "ver" is created by U-Boot showing the U-Boot
1358 version as printed by the "version" command.
1359 Any change to this variable will be reverted at the
1364 When CONFIG_CMD_DATE is selected, the type of the RTC
1365 has to be selected, too. Define exactly one of the
1368 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1369 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1370 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1371 CONFIG_RTC_MC146818 - use MC146818 RTC
1372 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1373 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1374 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1375 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1376 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1377 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1378 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1379 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1380 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1383 Note that if the RTC uses I2C, then the I2C interface
1384 must also be configured. See I2C Support, below.
1387 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1389 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1390 chip-ngpio pairs that tell the PCA953X driver the number of
1391 pins supported by a particular chip.
1393 Note that if the GPIO device uses I2C, then the I2C interface
1394 must also be configured. See I2C Support, below.
1397 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1398 accesses and can checksum them or write a list of them out
1399 to memory. See the 'iotrace' command for details. This is
1400 useful for testing device drivers since it can confirm that
1401 the driver behaves the same way before and after a code
1402 change. Currently this is supported on sandbox and arm. To
1403 add support for your architecture, add '#include <iotrace.h>'
1404 to the bottom of arch/<arch>/include/asm/io.h and test.
1406 Example output from the 'iotrace stats' command is below.
1407 Note that if the trace buffer is exhausted, the checksum will
1408 still continue to operate.
1411 Start: 10000000 (buffer start address)
1412 Size: 00010000 (buffer size)
1413 Offset: 00000120 (current buffer offset)
1414 Output: 10000120 (start + offset)
1415 Count: 00000018 (number of trace records)
1416 CRC32: 9526fb66 (CRC32 of all trace records)
1418 - Timestamp Support:
1420 When CONFIG_TIMESTAMP is selected, the timestamp
1421 (date and time) of an image is printed by image
1422 commands like bootm or iminfo. This option is
1423 automatically enabled when you select CONFIG_CMD_DATE .
1425 - Partition Labels (disklabels) Supported:
1426 Zero or more of the following:
1427 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1428 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1429 Intel architecture, USB sticks, etc.
1430 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1431 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1432 bootloader. Note 2TB partition limit; see
1434 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1436 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1437 CONFIG_CMD_SCSI) you must configure support for at
1438 least one non-MTD partition type as well.
1441 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1442 board configurations files but used nowhere!
1444 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1445 be performed by calling the function
1446 ide_set_reset(int reset)
1447 which has to be defined in a board specific file
1452 Set this to enable ATAPI support.
1457 Set this to enable support for disks larger than 137GB
1458 Also look at CONFIG_SYS_64BIT_LBA.
1459 Whithout these , LBA48 support uses 32bit variables and will 'only'
1460 support disks up to 2.1TB.
1462 CONFIG_SYS_64BIT_LBA:
1463 When enabled, makes the IDE subsystem use 64bit sector addresses.
1467 At the moment only there is only support for the
1468 SYM53C8XX SCSI controller; define
1469 CONFIG_SCSI_SYM53C8XX to enable it.
1471 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1472 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1473 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1474 maximum numbers of LUNs, SCSI ID's and target
1476 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1478 The environment variable 'scsidevs' is set to the number of
1479 SCSI devices found during the last scan.
1481 - NETWORK Support (PCI):
1483 Support for Intel 8254x/8257x gigabit chips.
1486 Utility code for direct access to the SPI bus on Intel 8257x.
1487 This does not do anything useful unless you set at least one
1488 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1490 CONFIG_E1000_SPI_GENERIC
1491 Allow generic access to the SPI bus on the Intel 8257x, for
1492 example with the "sspi" command.
1495 Management command for E1000 devices. When used on devices
1496 with SPI support you can reprogram the EEPROM from U-Boot.
1498 CONFIG_E1000_FALLBACK_MAC
1499 default MAC for empty EEPROM after production.
1502 Support for Intel 82557/82559/82559ER chips.
1503 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1504 write routine for first time initialisation.
1507 Support for Digital 2114x chips.
1508 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1509 modem chip initialisation (KS8761/QS6611).
1512 Support for National dp83815 chips.
1515 Support for National dp8382[01] gigabit chips.
1517 - NETWORK Support (other):
1519 CONFIG_DRIVER_AT91EMAC
1520 Support for AT91RM9200 EMAC.
1523 Define this to use reduced MII inteface
1525 CONFIG_DRIVER_AT91EMAC_QUIET
1526 If this defined, the driver is quiet.
1527 The driver doen't show link status messages.
1529 CONFIG_CALXEDA_XGMAC
1530 Support for the Calxeda XGMAC device
1533 Support for SMSC's LAN91C96 chips.
1535 CONFIG_LAN91C96_BASE
1536 Define this to hold the physical address
1537 of the LAN91C96's I/O space
1539 CONFIG_LAN91C96_USE_32_BIT
1540 Define this to enable 32 bit addressing
1543 Support for SMSC's LAN91C111 chip
1545 CONFIG_SMC91111_BASE
1546 Define this to hold the physical address
1547 of the device (I/O space)
1549 CONFIG_SMC_USE_32_BIT
1550 Define this if data bus is 32 bits
1552 CONFIG_SMC_USE_IOFUNCS
1553 Define this to use i/o functions instead of macros
1554 (some hardware wont work with macros)
1556 CONFIG_DRIVER_TI_EMAC
1557 Support for davinci emac
1559 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1560 Define this if you have more then 3 PHYs.
1563 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1565 CONFIG_FTGMAC100_EGIGA
1566 Define this to use GE link update with gigabit PHY.
1567 Define this if FTGMAC100 is connected to gigabit PHY.
1568 If your system has 10/100 PHY only, it might not occur
1569 wrong behavior. Because PHY usually return timeout or
1570 useless data when polling gigabit status and gigabit
1571 control registers. This behavior won't affect the
1572 correctnessof 10/100 link speed update.
1575 Support for SMSC's LAN911x and LAN921x chips
1578 Define this to hold the physical address
1579 of the device (I/O space)
1581 CONFIG_SMC911X_32_BIT
1582 Define this if data bus is 32 bits
1584 CONFIG_SMC911X_16_BIT
1585 Define this if data bus is 16 bits. If your processor
1586 automatically converts one 32 bit word to two 16 bit
1587 words you may also try CONFIG_SMC911X_32_BIT.
1590 Support for Renesas on-chip Ethernet controller
1592 CONFIG_SH_ETHER_USE_PORT
1593 Define the number of ports to be used
1595 CONFIG_SH_ETHER_PHY_ADDR
1596 Define the ETH PHY's address
1598 CONFIG_SH_ETHER_CACHE_WRITEBACK
1599 If this option is set, the driver enables cache flush.
1603 Support for PWM modul on the imx6.
1607 Support TPM devices.
1610 Support for i2c bus TPM devices. Only one device
1611 per system is supported at this time.
1613 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1614 Define the the i2c bus number for the TPM device
1616 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1617 Define the TPM's address on the i2c bus
1619 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1620 Define the burst count bytes upper limit
1622 CONFIG_TPM_ATMEL_TWI
1623 Support for Atmel TWI TPM device. Requires I2C support.
1626 Support for generic parallel port TPM devices. Only one device
1627 per system is supported at this time.
1629 CONFIG_TPM_TIS_BASE_ADDRESS
1630 Base address where the generic TPM device is mapped
1631 to. Contemporary x86 systems usually map it at
1635 Add tpm monitor functions.
1636 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1637 provides monitor access to authorized functions.
1640 Define this to enable the TPM support library which provides
1641 functional interfaces to some TPM commands.
1642 Requires support for a TPM device.
1644 CONFIG_TPM_AUTH_SESSIONS
1645 Define this to enable authorized functions in the TPM library.
1646 Requires CONFIG_TPM and CONFIG_SHA1.
1649 At the moment only the UHCI host controller is
1650 supported (PIP405, MIP405, MPC5200); define
1651 CONFIG_USB_UHCI to enable it.
1652 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1653 and define CONFIG_USB_STORAGE to enable the USB
1656 Supported are USB Keyboards and USB Floppy drives
1658 MPC5200 USB requires additional defines:
1660 for 528 MHz Clock: 0x0001bbbb
1664 for differential drivers: 0x00001000
1665 for single ended drivers: 0x00005000
1666 for differential drivers on PSC3: 0x00000100
1667 for single ended drivers on PSC3: 0x00004100
1668 CONFIG_SYS_USB_EVENT_POLL
1669 May be defined to allow interrupt polling
1670 instead of using asynchronous interrupts
1672 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1673 txfilltuning field in the EHCI controller on reset.
1675 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1676 HW module registers.
1679 Define the below if you wish to use the USB console.
1680 Once firmware is rebuilt from a serial console issue the
1681 command "setenv stdin usbtty; setenv stdout usbtty" and
1682 attach your USB cable. The Unix command "dmesg" should print
1683 it has found a new device. The environment variable usbtty
1684 can be set to gserial or cdc_acm to enable your device to
1685 appear to a USB host as a Linux gserial device or a
1686 Common Device Class Abstract Control Model serial device.
1687 If you select usbtty = gserial you should be able to enumerate
1689 # modprobe usbserial vendor=0xVendorID product=0xProductID
1690 else if using cdc_acm, simply setting the environment
1691 variable usbtty to be cdc_acm should suffice. The following
1692 might be defined in YourBoardName.h
1695 Define this to build a UDC device
1698 Define this to have a tty type of device available to
1699 talk to the UDC device
1702 Define this to enable the high speed support for usb
1703 device and usbtty. If this feature is enabled, a routine
1704 int is_usbd_high_speed(void)
1705 also needs to be defined by the driver to dynamically poll
1706 whether the enumeration has succeded at high speed or full
1709 CONFIG_SYS_CONSOLE_IS_IN_ENV
1710 Define this if you want stdin, stdout &/or stderr to
1714 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1715 Derive USB clock from external clock "blah"
1716 - CONFIG_SYS_USB_EXTC_CLK 0x02
1718 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1719 Derive USB clock from brgclk
1720 - CONFIG_SYS_USB_BRG_CLK 0x04
1722 If you have a USB-IF assigned VendorID then you may wish to
1723 define your own vendor specific values either in BoardName.h
1724 or directly in usbd_vendor_info.h. If you don't define
1725 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1726 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1727 should pretend to be a Linux device to it's target host.
1729 CONFIG_USBD_MANUFACTURER
1730 Define this string as the name of your company for
1731 - CONFIG_USBD_MANUFACTURER "my company"
1733 CONFIG_USBD_PRODUCT_NAME
1734 Define this string as the name of your product
1735 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1737 CONFIG_USBD_VENDORID
1738 Define this as your assigned Vendor ID from the USB
1739 Implementors Forum. This *must* be a genuine Vendor ID
1740 to avoid polluting the USB namespace.
1741 - CONFIG_USBD_VENDORID 0xFFFF
1743 CONFIG_USBD_PRODUCTID
1744 Define this as the unique Product ID
1746 - CONFIG_USBD_PRODUCTID 0xFFFF
1748 - ULPI Layer Support:
1749 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1750 the generic ULPI layer. The generic layer accesses the ULPI PHY
1751 via the platform viewport, so you need both the genric layer and
1752 the viewport enabled. Currently only Chipidea/ARC based
1753 viewport is supported.
1754 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1755 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1756 If your ULPI phy needs a different reference clock than the
1757 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1758 the appropriate value in Hz.
1761 The MMC controller on the Intel PXA is supported. To
1762 enable this define CONFIG_MMC. The MMC can be
1763 accessed from the boot prompt by mapping the device
1764 to physical memory similar to flash. Command line is
1765 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1766 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1769 Support for Renesas on-chip MMCIF controller
1771 CONFIG_SH_MMCIF_ADDR
1772 Define the base address of MMCIF registers
1775 Define the clock frequency for MMCIF
1778 Enable the generic MMC driver
1780 CONFIG_SUPPORT_EMMC_BOOT
1781 Enable some additional features of the eMMC boot partitions.
1783 CONFIG_SUPPORT_EMMC_RPMB
1784 Enable the commands for reading, writing and programming the
1785 key for the Replay Protection Memory Block partition in eMMC.
1787 - USB Device Firmware Update (DFU) class support:
1789 This enables the USB portion of the DFU USB class
1792 This enables the command "dfu" which is used to have
1793 U-Boot create a DFU class device via USB. This command
1794 requires that the "dfu_alt_info" environment variable be
1795 set and define the alt settings to expose to the host.
1798 This enables support for exposing (e)MMC devices via DFU.
1801 This enables support for exposing NAND devices via DFU.
1804 This enables support for exposing RAM via DFU.
1805 Note: DFU spec refer to non-volatile memory usage, but
1806 allow usages beyond the scope of spec - here RAM usage,
1807 one that would help mostly the developer.
1809 CONFIG_SYS_DFU_DATA_BUF_SIZE
1810 Dfu transfer uses a buffer before writing data to the
1811 raw storage device. Make the size (in bytes) of this buffer
1812 configurable. The size of this buffer is also configurable
1813 through the "dfu_bufsiz" environment variable.
1815 CONFIG_SYS_DFU_MAX_FILE_SIZE
1816 When updating files rather than the raw storage device,
1817 we use a static buffer to copy the file into and then write
1818 the buffer once we've been given the whole file. Define
1819 this to the maximum filesize (in bytes) for the buffer.
1820 Default is 4 MiB if undefined.
1822 DFU_DEFAULT_POLL_TIMEOUT
1823 Poll timeout [ms], is the timeout a device can send to the
1824 host. The host must wait for this timeout before sending
1825 a subsequent DFU_GET_STATUS request to the device.
1827 DFU_MANIFEST_POLL_TIMEOUT
1828 Poll timeout [ms], which the device sends to the host when
1829 entering dfuMANIFEST state. Host waits this timeout, before
1830 sending again an USB request to the device.
1832 - USB Device Android Fastboot support:
1834 This enables the command "fastboot" which enables the Android
1835 fastboot mode for the platform's USB device. Fastboot is a USB
1836 protocol for downloading images, flashing and device control
1837 used on Android devices.
1838 See doc/README.android-fastboot for more information.
1840 CONFIG_ANDROID_BOOT_IMAGE
1841 This enables support for booting images which use the Android
1842 image format header.
1844 CONFIG_USB_FASTBOOT_BUF_ADDR
1845 The fastboot protocol requires a large memory buffer for
1846 downloads. Define this to the starting RAM address to use for
1849 CONFIG_USB_FASTBOOT_BUF_SIZE
1850 The fastboot protocol requires a large memory buffer for
1851 downloads. This buffer should be as large as possible for a
1852 platform. Define this to the size available RAM for fastboot.
1854 CONFIG_FASTBOOT_FLASH
1855 The fastboot protocol includes a "flash" command for writing
1856 the downloaded image to a non-volatile storage device. Define
1857 this to enable the "fastboot flash" command.
1859 CONFIG_FASTBOOT_FLASH_MMC_DEV
1860 The fastboot "flash" command requires additional information
1861 regarding the non-volatile storage device. Define this to
1862 the eMMC device that fastboot should use to store the image.
1864 CONFIG_FASTBOOT_GPT_NAME
1865 The fastboot "flash" command supports writing the downloaded
1866 image to the Protective MBR and the Primary GUID Partition
1867 Table. (Additionally, this downloaded image is post-processed
1868 to generate and write the Backup GUID Partition Table.)
1869 This occurs when the specified "partition name" on the
1870 "fastboot flash" command line matches this value.
1871 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1873 - Journaling Flash filesystem support:
1874 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1875 CONFIG_JFFS2_NAND_DEV
1876 Define these for a default partition on a NAND device
1878 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1879 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1880 Define these for a default partition on a NOR device
1882 CONFIG_SYS_JFFS_CUSTOM_PART
1883 Define this to create an own partition. You have to provide a
1884 function struct part_info* jffs2_part_info(int part_num)
1886 If you define only one JFFS2 partition you may also want to
1887 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1888 to disable the command chpart. This is the default when you
1889 have not defined a custom partition
1891 - FAT(File Allocation Table) filesystem write function support:
1894 Define this to enable support for saving memory data as a
1895 file in FAT formatted partition.
1897 This will also enable the command "fatwrite" enabling the
1898 user to write files to FAT.
1900 CBFS (Coreboot Filesystem) support
1903 Define this to enable support for reading from a Coreboot
1904 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1907 - FAT(File Allocation Table) filesystem cluster size:
1908 CONFIG_FS_FAT_MAX_CLUSTSIZE
1910 Define the max cluster size for fat operations else
1911 a default value of 65536 will be defined.
1916 Define this to enable standard (PC-Style) keyboard
1920 Standard PC keyboard driver with US (is default) and
1921 GERMAN key layout (switch via environment 'keymap=de') support.
1922 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1923 for cfb_console. Supports cursor blinking.
1926 Enables a Chrome OS keyboard using the CROS_EC interface.
1927 This uses CROS_EC to communicate with a second microcontroller
1928 which provides key scans on request.
1933 Define this to enable video support (for output to
1936 CONFIG_VIDEO_CT69000
1938 Enable Chips & Technologies 69000 Video chip
1940 CONFIG_VIDEO_SMI_LYNXEM
1941 Enable Silicon Motion SMI 712/710/810 Video chip. The
1942 video output is selected via environment 'videoout'
1943 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1946 For the CT69000 and SMI_LYNXEM drivers, videomode is
1947 selected via environment 'videomode'. Two different ways
1949 - "videomode=num" 'num' is a standard LiLo mode numbers.
1950 Following standard modes are supported (* is default):
1952 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1953 -------------+---------------------------------------------
1954 8 bits | 0x301* 0x303 0x305 0x161 0x307
1955 15 bits | 0x310 0x313 0x316 0x162 0x319
1956 16 bits | 0x311 0x314 0x317 0x163 0x31A
1957 24 bits | 0x312 0x315 0x318 ? 0x31B
1958 -------------+---------------------------------------------
1959 (i.e. setenv videomode 317; saveenv; reset;)
1961 - "videomode=bootargs" all the video parameters are parsed
1962 from the bootargs. (See drivers/video/videomodes.c)
1965 CONFIG_VIDEO_SED13806
1966 Enable Epson SED13806 driver. This driver supports 8bpp
1967 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1968 or CONFIG_VIDEO_SED13806_16BPP
1971 Enable the Freescale DIU video driver. Reference boards for
1972 SOCs that have a DIU should define this macro to enable DIU
1973 support, and should also define these other macros:
1979 CONFIG_VIDEO_SW_CURSOR
1980 CONFIG_VGA_AS_SINGLE_DEVICE
1982 CONFIG_VIDEO_BMP_LOGO
1984 The DIU driver will look for the 'video-mode' environment
1985 variable, and if defined, enable the DIU as a console during
1986 boot. See the documentation file README.video for a
1987 description of this variable.
1993 Define this to enable a custom keyboard support.
1994 This simply calls drv_keyboard_init() which must be
1995 defined in your board-specific files.
1996 The only board using this so far is RBC823.
1998 - LCD Support: CONFIG_LCD
2000 Define this to enable LCD support (for output to LCD
2001 display); also select one of the supported displays
2002 by defining one of these:
2006 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2008 CONFIG_NEC_NL6448AC33:
2010 NEC NL6448AC33-18. Active, color, single scan.
2012 CONFIG_NEC_NL6448BC20
2014 NEC NL6448BC20-08. 6.5", 640x480.
2015 Active, color, single scan.
2017 CONFIG_NEC_NL6448BC33_54
2019 NEC NL6448BC33-54. 10.4", 640x480.
2020 Active, color, single scan.
2024 Sharp 320x240. Active, color, single scan.
2025 It isn't 16x9, and I am not sure what it is.
2027 CONFIG_SHARP_LQ64D341
2029 Sharp LQ64D341 display, 640x480.
2030 Active, color, single scan.
2034 HLD1045 display, 640x480.
2035 Active, color, single scan.
2039 Optrex CBL50840-2 NF-FW 99 22 M5
2041 Hitachi LMG6912RPFC-00T
2045 320x240. Black & white.
2047 Normally display is black on white background; define
2048 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2050 CONFIG_LCD_ALIGNMENT
2052 Normally the LCD is page-aligned (typically 4KB). If this is
2053 defined then the LCD will be aligned to this value instead.
2054 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2055 here, since it is cheaper to change data cache settings on
2056 a per-section basis.
2058 CONFIG_CONSOLE_SCROLL_LINES
2060 When the console need to be scrolled, this is the number of
2061 lines to scroll by. It defaults to 1. Increasing this makes
2062 the console jump but can help speed up operation when scrolling
2067 Sometimes, for example if the display is mounted in portrait
2068 mode or even if it's mounted landscape but rotated by 180degree,
2069 we need to rotate our content of the display relative to the
2070 framebuffer, so that user can read the messages which are
2072 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2073 initialized with a given rotation from "vl_rot" out of
2074 "vidinfo_t" which is provided by the board specific code.
2075 The value for vl_rot is coded as following (matching to
2076 fbcon=rotate:<n> linux-kernel commandline):
2077 0 = no rotation respectively 0 degree
2078 1 = 90 degree rotation
2079 2 = 180 degree rotation
2080 3 = 270 degree rotation
2082 If CONFIG_LCD_ROTATION is not defined, the console will be
2083 initialized with 0degree rotation.
2087 Support drawing of RLE8-compressed bitmaps on the LCD.
2091 Enables an 'i2c edid' command which can read EDID
2092 information over I2C from an attached LCD display.
2094 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2096 If this option is set, the environment is checked for
2097 a variable "splashimage". If found, the usual display
2098 of logo, copyright and system information on the LCD
2099 is suppressed and the BMP image at the address
2100 specified in "splashimage" is loaded instead. The
2101 console is redirected to the "nulldev", too. This
2102 allows for a "silent" boot where a splash screen is
2103 loaded very quickly after power-on.
2105 CONFIG_SPLASHIMAGE_GUARD
2107 If this option is set, then U-Boot will prevent the environment
2108 variable "splashimage" from being set to a problematic address
2109 (see README.displaying-bmps).
2110 This option is useful for targets where, due to alignment
2111 restrictions, an improperly aligned BMP image will cause a data
2112 abort. If you think you will not have problems with unaligned
2113 accesses (for example because your toolchain prevents them)
2114 there is no need to set this option.
2116 CONFIG_SPLASH_SCREEN_ALIGN
2118 If this option is set the splash image can be freely positioned
2119 on the screen. Environment variable "splashpos" specifies the
2120 position as "x,y". If a positive number is given it is used as
2121 number of pixel from left/top. If a negative number is given it
2122 is used as number of pixel from right/bottom. You can also
2123 specify 'm' for centering the image.
2126 setenv splashpos m,m
2127 => image at center of screen
2129 setenv splashpos 30,20
2130 => image at x = 30 and y = 20
2132 setenv splashpos -10,m
2133 => vertically centered image
2134 at x = dspWidth - bmpWidth - 9
2136 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2138 If this option is set, additionally to standard BMP
2139 images, gzipped BMP images can be displayed via the
2140 splashscreen support or the bmp command.
2142 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2144 If this option is set, 8-bit RLE compressed BMP images
2145 can be displayed via the splashscreen support or the
2148 - Do compressing for memory range:
2151 If this option is set, it would use zlib deflate method
2152 to compress the specified memory at its best effort.
2154 - Compression support:
2157 Enabled by default to support gzip compressed images.
2161 If this option is set, support for bzip2 compressed
2162 images is included. If not, only uncompressed and gzip
2163 compressed images are supported.
2165 NOTE: the bzip2 algorithm requires a lot of RAM, so
2166 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2171 If this option is set, support for lzma compressed
2174 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2175 requires an amount of dynamic memory that is given by the
2178 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2180 Where lc and lp stand for, respectively, Literal context bits
2181 and Literal pos bits.
2183 This value is upper-bounded by 14MB in the worst case. Anyway,
2184 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2185 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2186 a very small buffer.
2188 Use the lzmainfo tool to determinate the lc and lp values and
2189 then calculate the amount of needed dynamic memory (ensuring
2190 the appropriate CONFIG_SYS_MALLOC_LEN value).
2194 If this option is set, support for LZO compressed images
2200 The address of PHY on MII bus.
2202 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2204 The clock frequency of the MII bus
2208 If this option is set, support for speed/duplex
2209 detection of gigabit PHY is included.
2211 CONFIG_PHY_RESET_DELAY
2213 Some PHY like Intel LXT971A need extra delay after
2214 reset before any MII register access is possible.
2215 For such PHY, set this option to the usec delay
2216 required. (minimum 300usec for LXT971A)
2218 CONFIG_PHY_CMD_DELAY (ppc4xx)
2220 Some PHY like Intel LXT971A need extra delay after
2221 command issued before MII status register can be read
2226 Define a default value for the IP address to use for
2227 the default Ethernet interface, in case this is not
2228 determined through e.g. bootp.
2229 (Environment variable "ipaddr")
2231 - Server IP address:
2234 Defines a default value for the IP address of a TFTP
2235 server to contact when using the "tftboot" command.
2236 (Environment variable "serverip")
2238 CONFIG_KEEP_SERVERADDR
2240 Keeps the server's MAC address, in the env 'serveraddr'
2241 for passing to bootargs (like Linux's netconsole option)
2243 - Gateway IP address:
2246 Defines a default value for the IP address of the
2247 default router where packets to other networks are
2249 (Environment variable "gatewayip")
2254 Defines a default value for the subnet mask (or
2255 routing prefix) which is used to determine if an IP
2256 address belongs to the local subnet or needs to be
2257 forwarded through a router.
2258 (Environment variable "netmask")
2260 - Multicast TFTP Mode:
2263 Defines whether you want to support multicast TFTP as per
2264 rfc-2090; for example to work with atftp. Lets lots of targets
2265 tftp down the same boot image concurrently. Note: the Ethernet
2266 driver in use must provide a function: mcast() to join/leave a
2269 - BOOTP Recovery Mode:
2270 CONFIG_BOOTP_RANDOM_DELAY
2272 If you have many targets in a network that try to
2273 boot using BOOTP, you may want to avoid that all
2274 systems send out BOOTP requests at precisely the same
2275 moment (which would happen for instance at recovery
2276 from a power failure, when all systems will try to
2277 boot, thus flooding the BOOTP server. Defining
2278 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2279 inserted before sending out BOOTP requests. The
2280 following delays are inserted then:
2282 1st BOOTP request: delay 0 ... 1 sec
2283 2nd BOOTP request: delay 0 ... 2 sec
2284 3rd BOOTP request: delay 0 ... 4 sec
2286 BOOTP requests: delay 0 ... 8 sec
2288 CONFIG_BOOTP_ID_CACHE_SIZE
2290 BOOTP packets are uniquely identified using a 32-bit ID. The
2291 server will copy the ID from client requests to responses and
2292 U-Boot will use this to determine if it is the destination of
2293 an incoming response. Some servers will check that addresses
2294 aren't in use before handing them out (usually using an ARP
2295 ping) and therefore take up to a few hundred milliseconds to
2296 respond. Network congestion may also influence the time it
2297 takes for a response to make it back to the client. If that
2298 time is too long, U-Boot will retransmit requests. In order
2299 to allow earlier responses to still be accepted after these
2300 retransmissions, U-Boot's BOOTP client keeps a small cache of
2301 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2302 cache. The default is to keep IDs for up to four outstanding
2303 requests. Increasing this will allow U-Boot to accept offers
2304 from a BOOTP client in networks with unusually high latency.
2306 - BOOTP Random transaction ID:
2307 CONFIG_BOOTP_RANDOM_ID
2309 The standard algorithm to generate a DHCP/BOOTP transaction ID
2310 by using the MAC address and the current time stamp may not
2311 quite unlikely produce duplicate transaction IDs from different
2312 clients in the same network. This option creates a transaction
2313 ID using the rand() function. Provided that the RNG has been
2314 seeded well, this should guarantee unique transaction IDs
2317 - DHCP Advanced Options:
2318 You can fine tune the DHCP functionality by defining
2319 CONFIG_BOOTP_* symbols:
2321 CONFIG_BOOTP_SUBNETMASK
2322 CONFIG_BOOTP_GATEWAY
2323 CONFIG_BOOTP_HOSTNAME
2324 CONFIG_BOOTP_NISDOMAIN
2325 CONFIG_BOOTP_BOOTPATH
2326 CONFIG_BOOTP_BOOTFILESIZE
2329 CONFIG_BOOTP_SEND_HOSTNAME
2330 CONFIG_BOOTP_NTPSERVER
2331 CONFIG_BOOTP_TIMEOFFSET
2332 CONFIG_BOOTP_VENDOREX
2333 CONFIG_BOOTP_MAY_FAIL
2335 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2336 environment variable, not the BOOTP server.
2338 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2339 after the configured retry count, the call will fail
2340 instead of starting over. This can be used to fail over
2341 to Link-local IP address configuration if the DHCP server
2344 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2345 serverip from a DHCP server, it is possible that more
2346 than one DNS serverip is offered to the client.
2347 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2348 serverip will be stored in the additional environment
2349 variable "dnsip2". The first DNS serverip is always
2350 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2353 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2354 to do a dynamic update of a DNS server. To do this, they
2355 need the hostname of the DHCP requester.
2356 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2357 of the "hostname" environment variable is passed as
2358 option 12 to the DHCP server.
2360 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2362 A 32bit value in microseconds for a delay between
2363 receiving a "DHCP Offer" and sending the "DHCP Request".
2364 This fixes a problem with certain DHCP servers that don't
2365 respond 100% of the time to a "DHCP request". E.g. On an
2366 AT91RM9200 processor running at 180MHz, this delay needed
2367 to be *at least* 15,000 usec before a Windows Server 2003
2368 DHCP server would reply 100% of the time. I recommend at
2369 least 50,000 usec to be safe. The alternative is to hope
2370 that one of the retries will be successful but note that
2371 the DHCP timeout and retry process takes a longer than
2374 - Link-local IP address negotiation:
2375 Negotiate with other link-local clients on the local network
2376 for an address that doesn't require explicit configuration.
2377 This is especially useful if a DHCP server cannot be guaranteed
2378 to exist in all environments that the device must operate.
2380 See doc/README.link-local for more information.
2383 CONFIG_CDP_DEVICE_ID
2385 The device id used in CDP trigger frames.
2387 CONFIG_CDP_DEVICE_ID_PREFIX
2389 A two character string which is prefixed to the MAC address
2394 A printf format string which contains the ascii name of
2395 the port. Normally is set to "eth%d" which sets
2396 eth0 for the first Ethernet, eth1 for the second etc.
2398 CONFIG_CDP_CAPABILITIES
2400 A 32bit integer which indicates the device capabilities;
2401 0x00000010 for a normal host which does not forwards.
2405 An ascii string containing the version of the software.
2409 An ascii string containing the name of the platform.
2413 A 32bit integer sent on the trigger.
2415 CONFIG_CDP_POWER_CONSUMPTION
2417 A 16bit integer containing the power consumption of the
2418 device in .1 of milliwatts.
2420 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2422 A byte containing the id of the VLAN.
2424 - Status LED: CONFIG_STATUS_LED
2426 Several configurations allow to display the current
2427 status using a LED. For instance, the LED will blink
2428 fast while running U-Boot code, stop blinking as
2429 soon as a reply to a BOOTP request was received, and
2430 start blinking slow once the Linux kernel is running
2431 (supported by a status LED driver in the Linux
2432 kernel). Defining CONFIG_STATUS_LED enables this
2438 The status LED can be connected to a GPIO pin.
2439 In such cases, the gpio_led driver can be used as a
2440 status LED backend implementation. Define CONFIG_GPIO_LED
2441 to include the gpio_led driver in the U-Boot binary.
2443 CONFIG_GPIO_LED_INVERTED_TABLE
2444 Some GPIO connected LEDs may have inverted polarity in which
2445 case the GPIO high value corresponds to LED off state and
2446 GPIO low value corresponds to LED on state.
2447 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2448 with a list of GPIO LEDs that have inverted polarity.
2450 - CAN Support: CONFIG_CAN_DRIVER
2452 Defining CONFIG_CAN_DRIVER enables CAN driver support
2453 on those systems that support this (optional)
2454 feature, like the TQM8xxL modules.
2456 - I2C Support: CONFIG_SYS_I2C
2458 This enable the NEW i2c subsystem, and will allow you to use
2459 i2c commands at the u-boot command line (as long as you set
2460 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2461 based realtime clock chips or other i2c devices. See
2462 common/cmd_i2c.c for a description of the command line
2465 ported i2c driver to the new framework:
2466 - drivers/i2c/soft_i2c.c:
2467 - activate first bus with CONFIG_SYS_I2C_SOFT define
2468 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2469 for defining speed and slave address
2470 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2471 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2472 for defining speed and slave address
2473 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2474 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2475 for defining speed and slave address
2476 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2477 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2478 for defining speed and slave address
2480 - drivers/i2c/fsl_i2c.c:
2481 - activate i2c driver with CONFIG_SYS_I2C_FSL
2482 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2483 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2484 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2486 - If your board supports a second fsl i2c bus, define
2487 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2488 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2489 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2492 - drivers/i2c/tegra_i2c.c:
2493 - activate this driver with CONFIG_SYS_I2C_TEGRA
2494 - This driver adds 4 i2c buses with a fix speed from
2495 100000 and the slave addr 0!
2497 - drivers/i2c/ppc4xx_i2c.c
2498 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2499 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2500 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2502 - drivers/i2c/i2c_mxc.c
2503 - activate this driver with CONFIG_SYS_I2C_MXC
2504 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2505 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2506 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2507 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2508 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2509 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2510 If those defines are not set, default value is 100000
2511 for speed, and 0 for slave.
2512 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2513 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2515 - drivers/i2c/rcar_i2c.c:
2516 - activate this driver with CONFIG_SYS_I2C_RCAR
2517 - This driver adds 4 i2c buses
2519 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2520 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2521 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2522 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2523 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2524 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2525 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2526 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2527 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2529 - drivers/i2c/sh_i2c.c:
2530 - activate this driver with CONFIG_SYS_I2C_SH
2531 - This driver adds from 2 to 5 i2c buses
2533 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2534 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2535 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2536 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2537 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2538 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2539 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2540 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2541 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2542 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2543 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2544 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2545 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2547 - drivers/i2c/omap24xx_i2c.c
2548 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2549 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2550 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2551 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2552 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2553 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2554 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2555 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2556 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2557 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2558 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2560 - drivers/i2c/zynq_i2c.c
2561 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2562 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2563 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2565 - drivers/i2c/s3c24x0_i2c.c:
2566 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2567 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2568 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2569 with a fix speed from 100000 and the slave addr 0!
2571 - drivers/i2c/ihs_i2c.c
2572 - activate this driver with CONFIG_SYS_I2C_IHS
2573 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2574 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2575 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2576 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2577 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2578 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2579 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2580 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2581 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2582 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2583 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2584 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2588 CONFIG_SYS_NUM_I2C_BUSES
2589 Hold the number of i2c buses you want to use. If you
2590 don't use/have i2c muxes on your i2c bus, this
2591 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2594 CONFIG_SYS_I2C_DIRECT_BUS
2595 define this, if you don't use i2c muxes on your hardware.
2596 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2599 CONFIG_SYS_I2C_MAX_HOPS
2600 define how many muxes are maximal consecutively connected
2601 on one i2c bus. If you not use i2c muxes, omit this
2604 CONFIG_SYS_I2C_BUSES
2605 hold a list of buses you want to use, only used if
2606 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2607 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2608 CONFIG_SYS_NUM_I2C_BUSES = 9:
2610 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2612 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2613 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2614 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2615 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2616 {1, {I2C_NULL_HOP}}, \
2617 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2618 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2622 bus 0 on adapter 0 without a mux
2623 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2624 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2625 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2626 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2627 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2628 bus 6 on adapter 1 without a mux
2629 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2630 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2632 If you do not have i2c muxes on your board, omit this define.
2634 - Legacy I2C Support: CONFIG_HARD_I2C
2636 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2637 provides the following compelling advantages:
2639 - more than one i2c adapter is usable
2640 - approved multibus support
2641 - better i2c mux support
2643 ** Please consider updating your I2C driver now. **
2645 These enable legacy I2C serial bus commands. Defining
2646 CONFIG_HARD_I2C will include the appropriate I2C driver
2647 for the selected CPU.
2649 This will allow you to use i2c commands at the u-boot
2650 command line (as long as you set CONFIG_CMD_I2C in
2651 CONFIG_COMMANDS) and communicate with i2c based realtime
2652 clock chips. See common/cmd_i2c.c for a description of the
2653 command line interface.
2655 CONFIG_HARD_I2C selects a hardware I2C controller.
2657 There are several other quantities that must also be
2658 defined when you define CONFIG_HARD_I2C.
2660 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2661 to be the frequency (in Hz) at which you wish your i2c bus
2662 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2663 the CPU's i2c node address).
2665 Now, the u-boot i2c code for the mpc8xx
2666 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2667 and so its address should therefore be cleared to 0 (See,
2668 eg, MPC823e User's Manual p.16-473). So, set
2669 CONFIG_SYS_I2C_SLAVE to 0.
2671 CONFIG_SYS_I2C_INIT_MPC5XXX
2673 When a board is reset during an i2c bus transfer
2674 chips might think that the current transfer is still
2675 in progress. Reset the slave devices by sending start
2676 commands until the slave device responds.
2678 That's all that's required for CONFIG_HARD_I2C.
2680 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2681 then the following macros need to be defined (examples are
2682 from include/configs/lwmon.h):
2686 (Optional). Any commands necessary to enable the I2C
2687 controller or configure ports.
2689 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2693 (Only for MPC8260 CPU). The I/O port to use (the code
2694 assumes both bits are on the same port). Valid values
2695 are 0..3 for ports A..D.
2699 The code necessary to make the I2C data line active
2700 (driven). If the data line is open collector, this
2703 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2707 The code necessary to make the I2C data line tri-stated
2708 (inactive). If the data line is open collector, this
2711 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2715 Code that returns true if the I2C data line is high,
2718 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2722 If <bit> is true, sets the I2C data line high. If it
2723 is false, it clears it (low).
2725 eg: #define I2C_SDA(bit) \
2726 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2727 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2731 If <bit> is true, sets the I2C clock line high. If it
2732 is false, it clears it (low).
2734 eg: #define I2C_SCL(bit) \
2735 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2736 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2740 This delay is invoked four times per clock cycle so this
2741 controls the rate of data transfer. The data rate thus
2742 is 1 / (I2C_DELAY * 4). Often defined to be something
2745 #define I2C_DELAY udelay(2)
2747 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2749 If your arch supports the generic GPIO framework (asm/gpio.h),
2750 then you may alternatively define the two GPIOs that are to be
2751 used as SCL / SDA. Any of the previous I2C_xxx macros will
2752 have GPIO-based defaults assigned to them as appropriate.
2754 You should define these to the GPIO value as given directly to
2755 the generic GPIO functions.
2757 CONFIG_SYS_I2C_INIT_BOARD
2759 When a board is reset during an i2c bus transfer
2760 chips might think that the current transfer is still
2761 in progress. On some boards it is possible to access
2762 the i2c SCLK line directly, either by using the
2763 processor pin as a GPIO or by having a second pin
2764 connected to the bus. If this option is defined a
2765 custom i2c_init_board() routine in boards/xxx/board.c
2766 is run early in the boot sequence.
2768 CONFIG_SYS_I2C_BOARD_LATE_INIT
2770 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2771 defined a custom i2c_board_late_init() routine in
2772 boards/xxx/board.c is run AFTER the operations in i2c_init()
2773 is completed. This callpoint can be used to unreset i2c bus
2774 using CPU i2c controller register accesses for CPUs whose i2c
2775 controller provide such a method. It is called at the end of
2776 i2c_init() to allow i2c_init operations to setup the i2c bus
2777 controller on the CPU (e.g. setting bus speed & slave address).
2779 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2781 This option enables configuration of bi_iic_fast[] flags
2782 in u-boot bd_info structure based on u-boot environment
2783 variable "i2cfast". (see also i2cfast)
2785 CONFIG_I2C_MULTI_BUS
2787 This option allows the use of multiple I2C buses, each of which
2788 must have a controller. At any point in time, only one bus is
2789 active. To switch to a different bus, use the 'i2c dev' command.
2790 Note that bus numbering is zero-based.
2792 CONFIG_SYS_I2C_NOPROBES
2794 This option specifies a list of I2C devices that will be skipped
2795 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2796 is set, specify a list of bus-device pairs. Otherwise, specify
2797 a 1D array of device addresses
2800 #undef CONFIG_I2C_MULTI_BUS
2801 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2803 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2805 #define CONFIG_I2C_MULTI_BUS
2806 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2808 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2810 CONFIG_SYS_SPD_BUS_NUM
2812 If defined, then this indicates the I2C bus number for DDR SPD.
2813 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2815 CONFIG_SYS_RTC_BUS_NUM
2817 If defined, then this indicates the I2C bus number for the RTC.
2818 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2820 CONFIG_SYS_DTT_BUS_NUM
2822 If defined, then this indicates the I2C bus number for the DTT.
2823 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2825 CONFIG_SYS_I2C_DTT_ADDR:
2827 If defined, specifies the I2C address of the DTT device.
2828 If not defined, then U-Boot uses predefined value for
2829 specified DTT device.
2831 CONFIG_SOFT_I2C_READ_REPEATED_START
2833 defining this will force the i2c_read() function in
2834 the soft_i2c driver to perform an I2C repeated start
2835 between writing the address pointer and reading the
2836 data. If this define is omitted the default behaviour
2837 of doing a stop-start sequence will be used. Most I2C
2838 devices can use either method, but some require one or
2841 - SPI Support: CONFIG_SPI
2843 Enables SPI driver (so far only tested with
2844 SPI EEPROM, also an instance works with Crystal A/D and
2845 D/As on the SACSng board)
2849 Enables the driver for SPI controller on SuperH. Currently
2850 only SH7757 is supported.
2854 Enables extended (16-bit) SPI EEPROM addressing.
2855 (symmetrical to CONFIG_I2C_X)
2859 Enables a software (bit-bang) SPI driver rather than
2860 using hardware support. This is a general purpose
2861 driver that only requires three general I/O port pins
2862 (two outputs, one input) to function. If this is
2863 defined, the board configuration must define several
2864 SPI configuration items (port pins to use, etc). For
2865 an example, see include/configs/sacsng.h.
2869 Enables a hardware SPI driver for general-purpose reads
2870 and writes. As with CONFIG_SOFT_SPI, the board configuration
2871 must define a list of chip-select function pointers.
2872 Currently supported on some MPC8xxx processors. For an
2873 example, see include/configs/mpc8349emds.h.
2877 Enables the driver for the SPI controllers on i.MX and MXC
2878 SoCs. Currently i.MX31/35/51 are supported.
2880 CONFIG_SYS_SPI_MXC_WAIT
2881 Timeout for waiting until spi transfer completed.
2882 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2884 - FPGA Support: CONFIG_FPGA
2886 Enables FPGA subsystem.
2888 CONFIG_FPGA_<vendor>
2890 Enables support for specific chip vendors.
2893 CONFIG_FPGA_<family>
2895 Enables support for FPGA family.
2896 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2900 Specify the number of FPGA devices to support.
2902 CONFIG_CMD_FPGA_LOADMK
2904 Enable support for fpga loadmk command
2906 CONFIG_CMD_FPGA_LOADP
2908 Enable support for fpga loadp command - load partial bitstream
2910 CONFIG_CMD_FPGA_LOADBP
2912 Enable support for fpga loadbp command - load partial bitstream
2915 CONFIG_SYS_FPGA_PROG_FEEDBACK
2917 Enable printing of hash marks during FPGA configuration.
2919 CONFIG_SYS_FPGA_CHECK_BUSY
2921 Enable checks on FPGA configuration interface busy
2922 status by the configuration function. This option
2923 will require a board or device specific function to
2928 If defined, a function that provides delays in the FPGA
2929 configuration driver.
2931 CONFIG_SYS_FPGA_CHECK_CTRLC
2932 Allow Control-C to interrupt FPGA configuration
2934 CONFIG_SYS_FPGA_CHECK_ERROR
2936 Check for configuration errors during FPGA bitfile
2937 loading. For example, abort during Virtex II
2938 configuration if the INIT_B line goes low (which
2939 indicated a CRC error).
2941 CONFIG_SYS_FPGA_WAIT_INIT
2943 Maximum time to wait for the INIT_B line to de-assert
2944 after PROB_B has been de-asserted during a Virtex II
2945 FPGA configuration sequence. The default time is 500
2948 CONFIG_SYS_FPGA_WAIT_BUSY
2950 Maximum time to wait for BUSY to de-assert during
2951 Virtex II FPGA configuration. The default is 5 ms.
2953 CONFIG_SYS_FPGA_WAIT_CONFIG
2955 Time to wait after FPGA configuration. The default is
2958 - Configuration Management:
2961 Some SoCs need special image types (e.g. U-Boot binary
2962 with a special header) as build targets. By defining
2963 CONFIG_BUILD_TARGET in the SoC / board header, this
2964 special image will be automatically built upon calling
2969 If defined, this string will be added to the U-Boot
2970 version information (U_BOOT_VERSION)
2972 - Vendor Parameter Protection:
2974 U-Boot considers the values of the environment
2975 variables "serial#" (Board Serial Number) and
2976 "ethaddr" (Ethernet Address) to be parameters that
2977 are set once by the board vendor / manufacturer, and
2978 protects these variables from casual modification by
2979 the user. Once set, these variables are read-only,
2980 and write or delete attempts are rejected. You can
2981 change this behaviour:
2983 If CONFIG_ENV_OVERWRITE is #defined in your config
2984 file, the write protection for vendor parameters is
2985 completely disabled. Anybody can change or delete
2988 Alternatively, if you define _both_ an ethaddr in the
2989 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2990 Ethernet address is installed in the environment,
2991 which can be changed exactly ONCE by the user. [The
2992 serial# is unaffected by this, i. e. it remains
2995 The same can be accomplished in a more flexible way
2996 for any variable by configuring the type of access
2997 to allow for those variables in the ".flags" variable
2998 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3003 Define this variable to enable the reservation of
3004 "protected RAM", i. e. RAM which is not overwritten
3005 by U-Boot. Define CONFIG_PRAM to hold the number of
3006 kB you want to reserve for pRAM. You can overwrite
3007 this default value by defining an environment
3008 variable "pram" to the number of kB you want to
3009 reserve. Note that the board info structure will
3010 still show the full amount of RAM. If pRAM is
3011 reserved, a new environment variable "mem" will
3012 automatically be defined to hold the amount of
3013 remaining RAM in a form that can be passed as boot
3014 argument to Linux, for instance like that:
3016 setenv bootargs ... mem=\${mem}
3019 This way you can tell Linux not to use this memory,
3020 either, which results in a memory region that will
3021 not be affected by reboots.
3023 *WARNING* If your board configuration uses automatic
3024 detection of the RAM size, you must make sure that
3025 this memory test is non-destructive. So far, the
3026 following board configurations are known to be
3029 IVMS8, IVML24, SPD8xx, TQM8xxL,
3030 HERMES, IP860, RPXlite, LWMON,
3033 - Access to physical memory region (> 4GB)
3034 Some basic support is provided for operations on memory not
3035 normally accessible to U-Boot - e.g. some architectures
3036 support access to more than 4GB of memory on 32-bit
3037 machines using physical address extension or similar.
3038 Define CONFIG_PHYSMEM to access this basic support, which
3039 currently only supports clearing the memory.
3044 Define this variable to stop the system in case of a
3045 fatal error, so that you have to reset it manually.
3046 This is probably NOT a good idea for an embedded
3047 system where you want the system to reboot
3048 automatically as fast as possible, but it may be
3049 useful during development since you can try to debug
3050 the conditions that lead to the situation.
3052 CONFIG_NET_RETRY_COUNT
3054 This variable defines the number of retries for
3055 network operations like ARP, RARP, TFTP, or BOOTP
3056 before giving up the operation. If not defined, a
3057 default value of 5 is used.
3061 Timeout waiting for an ARP reply in milliseconds.
3065 Timeout in milliseconds used in NFS protocol.
3066 If you encounter "ERROR: Cannot umount" in nfs command,
3067 try longer timeout such as
3068 #define CONFIG_NFS_TIMEOUT 10000UL
3070 - Command Interpreter:
3071 CONFIG_AUTO_COMPLETE
3073 Enable auto completion of commands using TAB.
3075 CONFIG_SYS_PROMPT_HUSH_PS2
3077 This defines the secondary prompt string, which is
3078 printed when the command interpreter needs more input
3079 to complete a command. Usually "> ".
3083 In the current implementation, the local variables
3084 space and global environment variables space are
3085 separated. Local variables are those you define by
3086 simply typing `name=value'. To access a local
3087 variable later on, you have write `$name' or
3088 `${name}'; to execute the contents of a variable
3089 directly type `$name' at the command prompt.
3091 Global environment variables are those you use
3092 setenv/printenv to work with. To run a command stored
3093 in such a variable, you need to use the run command,
3094 and you must not use the '$' sign to access them.
3096 To store commands and special characters in a
3097 variable, please use double quotation marks
3098 surrounding the whole text of the variable, instead
3099 of the backslashes before semicolons and special
3102 - Command Line Editing and History:
3103 CONFIG_CMDLINE_EDITING
3105 Enable editing and History functions for interactive
3106 command line input operations
3108 - Default Environment:
3109 CONFIG_EXTRA_ENV_SETTINGS
3111 Define this to contain any number of null terminated
3112 strings (variable = value pairs) that will be part of
3113 the default environment compiled into the boot image.
3115 For example, place something like this in your
3116 board's config file:
3118 #define CONFIG_EXTRA_ENV_SETTINGS \
3122 Warning: This method is based on knowledge about the
3123 internal format how the environment is stored by the
3124 U-Boot code. This is NOT an official, exported
3125 interface! Although it is unlikely that this format
3126 will change soon, there is no guarantee either.
3127 You better know what you are doing here.
3129 Note: overly (ab)use of the default environment is
3130 discouraged. Make sure to check other ways to preset
3131 the environment like the "source" command or the
3134 CONFIG_ENV_VARS_UBOOT_CONFIG
3136 Define this in order to add variables describing the
3137 U-Boot build configuration to the default environment.
3138 These will be named arch, cpu, board, vendor, and soc.
3140 Enabling this option will cause the following to be defined:
3148 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3150 Define this in order to add variables describing certain
3151 run-time determined information about the hardware to the
3152 environment. These will be named board_name, board_rev.
3154 CONFIG_DELAY_ENVIRONMENT
3156 Normally the environment is loaded when the board is
3157 initialised so that it is available to U-Boot. This inhibits
3158 that so that the environment is not available until
3159 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3160 this is instead controlled by the value of
3161 /config/load-environment.
3163 - DataFlash Support:
3164 CONFIG_HAS_DATAFLASH
3166 Defining this option enables DataFlash features and
3167 allows to read/write in Dataflash via the standard
3170 - Serial Flash support
3173 Defining this option enables SPI flash commands
3174 'sf probe/read/write/erase/update'.
3176 Usage requires an initial 'probe' to define the serial
3177 flash parameters, followed by read/write/erase/update
3180 The following defaults may be provided by the platform
3181 to handle the common case when only a single serial
3182 flash is present on the system.
3184 CONFIG_SF_DEFAULT_BUS Bus identifier
3185 CONFIG_SF_DEFAULT_CS Chip-select
3186 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3187 CONFIG_SF_DEFAULT_SPEED in Hz
3191 Define this option to include a destructive SPI flash
3194 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3196 Define this option to use the Bank addr/Extended addr
3197 support on SPI flashes which has size > 16Mbytes.
3199 CONFIG_SF_DUAL_FLASH Dual flash memories
3201 Define this option to use dual flash support where two flash
3202 memories can be connected with a given cs line.
3203 Currently Xilinx Zynq qspi supports these type of connections.
3205 - SystemACE Support:
3208 Adding this option adds support for Xilinx SystemACE
3209 chips attached via some sort of local bus. The address
3210 of the chip must also be defined in the
3211 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3213 #define CONFIG_SYSTEMACE
3214 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3216 When SystemACE support is added, the "ace" device type
3217 becomes available to the fat commands, i.e. fatls.
3219 - TFTP Fixed UDP Port:
3222 If this is defined, the environment variable tftpsrcp
3223 is used to supply the TFTP UDP source port value.
3224 If tftpsrcp isn't defined, the normal pseudo-random port
3225 number generator is used.
3227 Also, the environment variable tftpdstp is used to supply
3228 the TFTP UDP destination port value. If tftpdstp isn't
3229 defined, the normal port 69 is used.
3231 The purpose for tftpsrcp is to allow a TFTP server to
3232 blindly start the TFTP transfer using the pre-configured
3233 target IP address and UDP port. This has the effect of
3234 "punching through" the (Windows XP) firewall, allowing
3235 the remainder of the TFTP transfer to proceed normally.
3236 A better solution is to properly configure the firewall,
3237 but sometimes that is not allowed.
3242 This enables a generic 'hash' command which can produce
3243 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3247 Enable the hash verify command (hash -v). This adds to code
3250 CONFIG_SHA1 - This option enables support of hashing using SHA1
3251 algorithm. The hash is calculated in software.
3252 CONFIG_SHA256 - This option enables support of hashing using
3253 SHA256 algorithm. The hash is calculated in software.
3254 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3255 for SHA1/SHA256 hashing.
3256 This affects the 'hash' command and also the
3257 hash_lookup_algo() function.
3258 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3259 hardware-acceleration for SHA1/SHA256 progressive hashing.
3260 Data can be streamed in a block at a time and the hashing
3261 is performed in hardware.
3263 Note: There is also a sha1sum command, which should perhaps
3264 be deprecated in favour of 'hash sha1'.
3266 - Freescale i.MX specific commands:
3267 CONFIG_CMD_HDMIDETECT
3268 This enables 'hdmidet' command which returns true if an
3269 HDMI monitor is detected. This command is i.MX 6 specific.
3272 This enables the 'bmode' (bootmode) command for forcing
3273 a boot from specific media.
3275 This is useful for forcing the ROM's usb downloader to
3276 activate upon a watchdog reset which is nice when iterating
3277 on U-Boot. Using the reset button or running bmode normal
3278 will set it back to normal. This command currently
3279 supports i.MX53 and i.MX6.
3284 This enables the RSA algorithm used for FIT image verification
3285 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3287 The Modular Exponentiation algorithm in RSA is implemented using
3288 driver model. So CONFIG_DM needs to be enabled by default for this
3289 library to function.
3291 The signing part is build into mkimage regardless of this
3292 option. The software based modular exponentiation is built into
3293 mkimage irrespective of this option.
3295 - bootcount support:
3296 CONFIG_BOOTCOUNT_LIMIT
3298 This enables the bootcounter support, see:
3299 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3302 enable special bootcounter support on at91sam9xe based boards.
3304 enable special bootcounter support on blackfin based boards.
3306 enable special bootcounter support on da850 based boards.
3307 CONFIG_BOOTCOUNT_RAM
3308 enable support for the bootcounter in RAM
3309 CONFIG_BOOTCOUNT_I2C
3310 enable support for the bootcounter on an i2c (like RTC) device.
3311 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3312 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3314 CONFIG_BOOTCOUNT_ALEN = address len
3316 - Show boot progress:
3317 CONFIG_SHOW_BOOT_PROGRESS
3319 Defining this option allows to add some board-
3320 specific code (calling a user-provided function
3321 "show_boot_progress(int)") that enables you to show
3322 the system's boot progress on some display (for
3323 example, some LED's) on your board. At the moment,
3324 the following checkpoints are implemented:
3327 Legacy uImage format:
3330 1 common/cmd_bootm.c before attempting to boot an image
3331 -1 common/cmd_bootm.c Image header has bad magic number
3332 2 common/cmd_bootm.c Image header has correct magic number
3333 -2 common/cmd_bootm.c Image header has bad checksum
3334 3 common/cmd_bootm.c Image header has correct checksum
3335 -3 common/cmd_bootm.c Image data has bad checksum
3336 4 common/cmd_bootm.c Image data has correct checksum
3337 -4 common/cmd_bootm.c Image is for unsupported architecture
3338 5 common/cmd_bootm.c Architecture check OK
3339 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3340 6 common/cmd_bootm.c Image Type check OK
3341 -6 common/cmd_bootm.c gunzip uncompression error
3342 -7 common/cmd_bootm.c Unimplemented compression type
3343 7 common/cmd_bootm.c Uncompression OK
3344 8 common/cmd_bootm.c No uncompress/copy overwrite error
3345 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3347 9 common/image.c Start initial ramdisk verification
3348 -10 common/image.c Ramdisk header has bad magic number
3349 -11 common/image.c Ramdisk header has bad checksum
3350 10 common/image.c Ramdisk header is OK
3351 -12 common/image.c Ramdisk data has bad checksum
3352 11 common/image.c Ramdisk data has correct checksum
3353 12 common/image.c Ramdisk verification complete, start loading
3354 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3355 13 common/image.c Start multifile image verification
3356 14 common/image.c No initial ramdisk, no multifile, continue.
3358 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3360 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3361 -31 post/post.c POST test failed, detected by post_output_backlog()
3362 -32 post/post.c POST test failed, detected by post_run_single()
3364 34 common/cmd_doc.c before loading a Image from a DOC device
3365 -35 common/cmd_doc.c Bad usage of "doc" command
3366 35 common/cmd_doc.c correct usage of "doc" command
3367 -36 common/cmd_doc.c No boot device
3368 36 common/cmd_doc.c correct boot device
3369 -37 common/cmd_doc.c Unknown Chip ID on boot device
3370 37 common/cmd_doc.c correct chip ID found, device available
3371 -38 common/cmd_doc.c Read Error on boot device
3372 38 common/cmd_doc.c reading Image header from DOC device OK
3373 -39 common/cmd_doc.c Image header has bad magic number
3374 39 common/cmd_doc.c Image header has correct magic number
3375 -40 common/cmd_doc.c Error reading Image from DOC device
3376 40 common/cmd_doc.c Image header has correct magic number
3377 41 common/cmd_ide.c before loading a Image from a IDE device
3378 -42 common/cmd_ide.c Bad usage of "ide" command
3379 42 common/cmd_ide.c correct usage of "ide" command
3380 -43 common/cmd_ide.c No boot device
3381 43 common/cmd_ide.c boot device found
3382 -44 common/cmd_ide.c Device not available
3383 44 common/cmd_ide.c Device available
3384 -45 common/cmd_ide.c wrong partition selected
3385 45 common/cmd_ide.c partition selected
3386 -46 common/cmd_ide.c Unknown partition table
3387 46 common/cmd_ide.c valid partition table found
3388 -47 common/cmd_ide.c Invalid partition type
3389 47 common/cmd_ide.c correct partition type
3390 -48 common/cmd_ide.c Error reading Image Header on boot device
3391 48 common/cmd_ide.c reading Image Header from IDE device OK
3392 -49 common/cmd_ide.c Image header has bad magic number
3393 49 common/cmd_ide.c Image header has correct magic number
3394 -50 common/cmd_ide.c Image header has bad checksum
3395 50 common/cmd_ide.c Image header has correct checksum
3396 -51 common/cmd_ide.c Error reading Image from IDE device
3397 51 common/cmd_ide.c reading Image from IDE device OK
3398 52 common/cmd_nand.c before loading a Image from a NAND device
3399 -53 common/cmd_nand.c Bad usage of "nand" command
3400 53 common/cmd_nand.c correct usage of "nand" command
3401 -54 common/cmd_nand.c No boot device
3402 54 common/cmd_nand.c boot device found
3403 -55 common/cmd_nand.c Unknown Chip ID on boot device
3404 55 common/cmd_nand.c correct chip ID found, device available
3405 -56 common/cmd_nand.c Error reading Image Header on boot device
3406 56 common/cmd_nand.c reading Image Header from NAND device OK
3407 -57 common/cmd_nand.c Image header has bad magic number
3408 57 common/cmd_nand.c Image header has correct magic number
3409 -58 common/cmd_nand.c Error reading Image from NAND device
3410 58 common/cmd_nand.c reading Image from NAND device OK
3412 -60 common/env_common.c Environment has a bad CRC, using default
3414 64 net/eth.c starting with Ethernet configuration.
3415 -64 net/eth.c no Ethernet found.
3416 65 net/eth.c Ethernet found.
3418 -80 common/cmd_net.c usage wrong
3419 80 common/cmd_net.c before calling net_loop()
3420 -81 common/cmd_net.c some error in net_loop() occurred
3421 81 common/cmd_net.c net_loop() back without error
3422 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3423 82 common/cmd_net.c trying automatic boot
3424 83 common/cmd_net.c running "source" command
3425 -83 common/cmd_net.c some error in automatic boot or "source" command
3426 84 common/cmd_net.c end without errors
3431 100 common/cmd_bootm.c Kernel FIT Image has correct format
3432 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3433 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3434 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3435 102 common/cmd_bootm.c Kernel unit name specified
3436 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3437 103 common/cmd_bootm.c Found configuration node
3438 104 common/cmd_bootm.c Got kernel subimage node offset
3439 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3440 105 common/cmd_bootm.c Kernel subimage hash verification OK
3441 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3442 106 common/cmd_bootm.c Architecture check OK
3443 -106 common/cmd_bootm.c Kernel subimage has wrong type
3444 107 common/cmd_bootm.c Kernel subimage type OK
3445 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3446 108 common/cmd_bootm.c Got kernel subimage data/size
3447 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3448 -109 common/cmd_bootm.c Can't get kernel subimage type
3449 -110 common/cmd_bootm.c Can't get kernel subimage comp
3450 -111 common/cmd_bootm.c Can't get kernel subimage os
3451 -112 common/cmd_bootm.c Can't get kernel subimage load address
3452 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3454 120 common/image.c Start initial ramdisk verification
3455 -120 common/image.c Ramdisk FIT image has incorrect format
3456 121 common/image.c Ramdisk FIT image has correct format
3457 122 common/image.c No ramdisk subimage unit name, using configuration
3458 -122 common/image.c Can't get configuration for ramdisk subimage
3459 123 common/image.c Ramdisk unit name specified
3460 -124 common/image.c Can't get ramdisk subimage node offset
3461 125 common/image.c Got ramdisk subimage node offset
3462 -125 common/image.c Ramdisk subimage hash verification failed
3463 126 common/image.c Ramdisk subimage hash verification OK
3464 -126 common/image.c Ramdisk subimage for unsupported architecture
3465 127 common/image.c Architecture check OK
3466 -127 common/image.c Can't get ramdisk subimage data/size
3467 128 common/image.c Got ramdisk subimage data/size
3468 129 common/image.c Can't get ramdisk load address
3469 -129 common/image.c Got ramdisk load address
3471 -130 common/cmd_doc.c Incorrect FIT image format
3472 131 common/cmd_doc.c FIT image format OK
3474 -140 common/cmd_ide.c Incorrect FIT image format
3475 141 common/cmd_ide.c FIT image format OK
3477 -150 common/cmd_nand.c Incorrect FIT image format
3478 151 common/cmd_nand.c FIT image format OK
3480 - legacy image format:
3481 CONFIG_IMAGE_FORMAT_LEGACY
3482 enables the legacy image format support in U-Boot.
3485 enabled if CONFIG_FIT_SIGNATURE is not defined.
3487 CONFIG_DISABLE_IMAGE_LEGACY
3488 disable the legacy image format
3490 This define is introduced, as the legacy image format is
3491 enabled per default for backward compatibility.
3493 - FIT image support:
3495 Enable support for the FIT uImage format.
3497 CONFIG_FIT_BEST_MATCH
3498 When no configuration is explicitly selected, default to the
3499 one whose fdt's compatibility field best matches that of
3500 U-Boot itself. A match is considered "best" if it matches the
3501 most specific compatibility entry of U-Boot's fdt's root node.
3502 The order of entries in the configuration's fdt is ignored.
3504 CONFIG_FIT_SIGNATURE
3505 This option enables signature verification of FIT uImages,
3506 using a hash signed and verified using RSA. If
3507 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3508 hashing is available using hardware, RSA library will use it.
3509 See doc/uImage.FIT/signature.txt for more details.
3511 WARNING: When relying on signed FIT images with required
3512 signature check the legacy image format is default
3513 disabled. If a board need legacy image format support
3514 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3516 CONFIG_FIT_DISABLE_SHA256
3517 Supporting SHA256 hashes has quite an impact on binary size.
3518 For constrained systems sha256 hash support can be disabled
3521 - Standalone program support:
3522 CONFIG_STANDALONE_LOAD_ADDR
3524 This option defines a board specific value for the
3525 address where standalone program gets loaded, thus
3526 overwriting the architecture dependent default
3529 - Frame Buffer Address:
3532 Define CONFIG_FB_ADDR if you want to use specific
3533 address for frame buffer. This is typically the case
3534 when using a graphics controller has separate video
3535 memory. U-Boot will then place the frame buffer at
3536 the given address instead of dynamically reserving it
3537 in system RAM by calling lcd_setmem(), which grabs
3538 the memory for the frame buffer depending on the
3539 configured panel size.
3541 Please see board_init_f function.
3543 - Automatic software updates via TFTP server
3545 CONFIG_UPDATE_TFTP_CNT_MAX
3546 CONFIG_UPDATE_TFTP_MSEC_MAX
3548 These options enable and control the auto-update feature;
3549 for a more detailed description refer to doc/README.update.
3551 - MTD Support (mtdparts command, UBI support)
3554 Adds the MTD device infrastructure from the Linux kernel.
3555 Needed for mtdparts command support.
3557 CONFIG_MTD_PARTITIONS
3559 Adds the MTD partitioning infrastructure from the Linux
3560 kernel. Needed for UBI support.
3565 Adds commands for interacting with MTD partitions formatted
3566 with the UBI flash translation layer
3568 Requires also defining CONFIG_RBTREE
3570 CONFIG_UBI_SILENCE_MSG
3572 Make the verbose messages from UBI stop printing. This leaves
3573 warnings and errors enabled.
3576 CONFIG_MTD_UBI_WL_THRESHOLD
3577 This parameter defines the maximum difference between the highest
3578 erase counter value and the lowest erase counter value of eraseblocks
3579 of UBI devices. When this threshold is exceeded, UBI starts performing
3580 wear leveling by means of moving data from eraseblock with low erase
3581 counter to eraseblocks with high erase counter.
3583 The default value should be OK for SLC NAND flashes, NOR flashes and
3584 other flashes which have eraseblock life-cycle 100000 or more.
3585 However, in case of MLC NAND flashes which typically have eraseblock
3586 life-cycle less than 10000, the threshold should be lessened (e.g.,
3587 to 128 or 256, although it does not have to be power of 2).
3591 CONFIG_MTD_UBI_BEB_LIMIT
3592 This option specifies the maximum bad physical eraseblocks UBI
3593 expects on the MTD device (per 1024 eraseblocks). If the
3594 underlying flash does not admit of bad eraseblocks (e.g. NOR
3595 flash), this value is ignored.
3597 NAND datasheets often specify the minimum and maximum NVM
3598 (Number of Valid Blocks) for the flashes' endurance lifetime.
3599 The maximum expected bad eraseblocks per 1024 eraseblocks
3600 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3601 which gives 20 for most NANDs (MaxNVB is basically the total
3602 count of eraseblocks on the chip).
3604 To put it differently, if this value is 20, UBI will try to
3605 reserve about 1.9% of physical eraseblocks for bad blocks
3606 handling. And that will be 1.9% of eraseblocks on the entire
3607 NAND chip, not just the MTD partition UBI attaches. This means
3608 that if you have, say, a NAND flash chip admits maximum 40 bad
3609 eraseblocks, and it is split on two MTD partitions of the same
3610 size, UBI will reserve 40 eraseblocks when attaching a
3615 CONFIG_MTD_UBI_FASTMAP
3616 Fastmap is a mechanism which allows attaching an UBI device
3617 in nearly constant time. Instead of scanning the whole MTD device it
3618 only has to locate a checkpoint (called fastmap) on the device.
3619 The on-flash fastmap contains all information needed to attach
3620 the device. Using fastmap makes only sense on large devices where
3621 attaching by scanning takes long. UBI will not automatically install
3622 a fastmap on old images, but you can set the UBI parameter
3623 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3624 that fastmap-enabled images are still usable with UBI implementations
3625 without fastmap support. On typical flash devices the whole fastmap
3626 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3628 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3629 Set this parameter to enable fastmap automatically on images
3636 Adds commands for interacting with UBI volumes formatted as
3637 UBIFS. UBIFS is read-only in u-boot.
3639 Requires UBI support as well as CONFIG_LZO
3641 CONFIG_UBIFS_SILENCE_MSG
3643 Make the verbose messages from UBIFS stop printing. This leaves
3644 warnings and errors enabled.
3648 Enable building of SPL globally.
3651 LDSCRIPT for linking the SPL binary.
3653 CONFIG_SPL_MAX_FOOTPRINT
3654 Maximum size in memory allocated to the SPL, BSS included.
3655 When defined, the linker checks that the actual memory
3656 used by SPL from _start to __bss_end does not exceed it.
3657 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3658 must not be both defined at the same time.
3661 Maximum size of the SPL image (text, data, rodata, and
3662 linker lists sections), BSS excluded.
3663 When defined, the linker checks that the actual size does
3666 CONFIG_SPL_TEXT_BASE
3667 TEXT_BASE for linking the SPL binary.
3669 CONFIG_SPL_RELOC_TEXT_BASE
3670 Address to relocate to. If unspecified, this is equal to
3671 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3673 CONFIG_SPL_BSS_START_ADDR
3674 Link address for the BSS within the SPL binary.
3676 CONFIG_SPL_BSS_MAX_SIZE
3677 Maximum size in memory allocated to the SPL BSS.
3678 When defined, the linker checks that the actual memory used
3679 by SPL from __bss_start to __bss_end does not exceed it.
3680 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3681 must not be both defined at the same time.
3684 Adress of the start of the stack SPL will use
3686 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3687 When defined, SPL will panic() if the image it has
3688 loaded does not have a signature.
3689 Defining this is useful when code which loads images
3690 in SPL cannot guarantee that absolutely all read errors
3692 An example is the LPC32XX MLC NAND driver, which will
3693 consider that a completely unreadable NAND block is bad,
3694 and thus should be skipped silently.
3696 CONFIG_SPL_RELOC_STACK
3697 Adress of the start of the stack SPL will use after
3698 relocation. If unspecified, this is equal to
3701 CONFIG_SYS_SPL_MALLOC_START
3702 Starting address of the malloc pool used in SPL.
3704 CONFIG_SYS_SPL_MALLOC_SIZE
3705 The size of the malloc pool used in SPL.
3707 CONFIG_SPL_FRAMEWORK
3708 Enable the SPL framework under common/. This framework
3709 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3710 NAND loading of the Linux Kernel.
3713 Enable booting directly to an OS from SPL.
3714 See also: doc/README.falcon
3716 CONFIG_SPL_DISPLAY_PRINT
3717 For ARM, enable an optional function to print more information
3718 about the running system.
3720 CONFIG_SPL_INIT_MINIMAL
3721 Arch init code should be built for a very small image
3723 CONFIG_SPL_LIBCOMMON_SUPPORT
3724 Support for common/libcommon.o in SPL binary
3726 CONFIG_SPL_LIBDISK_SUPPORT
3727 Support for disk/libdisk.o in SPL binary
3729 CONFIG_SPL_I2C_SUPPORT
3730 Support for drivers/i2c/libi2c.o in SPL binary
3732 CONFIG_SPL_GPIO_SUPPORT
3733 Support for drivers/gpio/libgpio.o in SPL binary
3735 CONFIG_SPL_MMC_SUPPORT
3736 Support for drivers/mmc/libmmc.o in SPL binary
3738 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3739 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3740 Address and partition on the MMC to load U-Boot from
3741 when the MMC is being used in raw mode.
3743 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3744 Partition on the MMC to load U-Boot from when the MMC is being
3747 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3748 Sector to load kernel uImage from when MMC is being
3749 used in raw mode (for Falcon mode)
3751 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3752 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3753 Sector and number of sectors to load kernel argument
3754 parameters from when MMC is being used in raw mode
3757 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3758 Partition on the MMC to load U-Boot from when the MMC is being
3761 CONFIG_SPL_FAT_SUPPORT
3762 Support for fs/fat/libfat.o in SPL binary
3764 CONFIG_SPL_EXT_SUPPORT
3765 Support for EXT filesystem in SPL binary
3767 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3768 Filename to read to load U-Boot when reading from filesystem
3770 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3771 Filename to read to load kernel uImage when reading
3772 from filesystem (for Falcon mode)
3774 CONFIG_SPL_FS_LOAD_ARGS_NAME
3775 Filename to read to load kernel argument parameters
3776 when reading from filesystem (for Falcon mode)
3778 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3779 Set this for NAND SPL on PPC mpc83xx targets, so that
3780 start.S waits for the rest of the SPL to load before
3781 continuing (the hardware starts execution after just
3782 loading the first page rather than the full 4K).
3784 CONFIG_SPL_SKIP_RELOCATE
3785 Avoid SPL relocation
3787 CONFIG_SPL_NAND_BASE
3788 Include nand_base.c in the SPL. Requires
3789 CONFIG_SPL_NAND_DRIVERS.
3791 CONFIG_SPL_NAND_DRIVERS
3792 SPL uses normal NAND drivers, not minimal drivers.
3795 Include standard software ECC in the SPL
3797 CONFIG_SPL_NAND_SIMPLE
3798 Support for NAND boot using simple NAND drivers that
3799 expose the cmd_ctrl() interface.
3801 CONFIG_SPL_MTD_SUPPORT
3802 Support for the MTD subsystem within SPL. Useful for
3803 environment on NAND support within SPL.
3805 CONFIG_SPL_NAND_RAW_ONLY
3806 Support to boot only raw u-boot.bin images. Use this only
3807 if you need to save space.
3809 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3810 Set for the SPL on PPC mpc8xxx targets, support for
3811 drivers/ddr/fsl/libddr.o in SPL binary.
3813 CONFIG_SPL_COMMON_INIT_DDR
3814 Set for common ddr init with serial presence detect in
3817 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3818 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3819 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3820 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3821 CONFIG_SYS_NAND_ECCBYTES
3822 Defines the size and behavior of the NAND that SPL uses
3825 CONFIG_SPL_NAND_BOOT
3826 Add support NAND boot
3828 CONFIG_SYS_NAND_U_BOOT_OFFS
3829 Location in NAND to read U-Boot from
3831 CONFIG_SYS_NAND_U_BOOT_DST
3832 Location in memory to load U-Boot to
3834 CONFIG_SYS_NAND_U_BOOT_SIZE
3835 Size of image to load
3837 CONFIG_SYS_NAND_U_BOOT_START
3838 Entry point in loaded image to jump to
3840 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3841 Define this if you need to first read the OOB and then the
3842 data. This is used, for example, on davinci platforms.
3844 CONFIG_SPL_OMAP3_ID_NAND
3845 Support for an OMAP3-specific set of functions to return the
3846 ID and MFR of the first attached NAND chip, if present.
3848 CONFIG_SPL_SERIAL_SUPPORT
3849 Support for drivers/serial/libserial.o in SPL binary
3851 CONFIG_SPL_SPI_FLASH_SUPPORT
3852 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3854 CONFIG_SPL_SPI_SUPPORT
3855 Support for drivers/spi/libspi.o in SPL binary
3857 CONFIG_SPL_RAM_DEVICE
3858 Support for running image already present in ram, in SPL binary
3860 CONFIG_SPL_LIBGENERIC_SUPPORT
3861 Support for lib/libgeneric.o in SPL binary
3863 CONFIG_SPL_ENV_SUPPORT
3864 Support for the environment operating in SPL binary
3866 CONFIG_SPL_NET_SUPPORT
3867 Support for the net/libnet.o in SPL binary.
3868 It conflicts with SPL env from storage medium specified by
3869 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3872 Image offset to which the SPL should be padded before appending
3873 the SPL payload. By default, this is defined as
3874 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3875 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3876 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3879 Final target image containing SPL and payload. Some SPLs
3880 use an arch-specific makefile fragment instead, for
3881 example if more than one image needs to be produced.
3883 CONFIG_FIT_SPL_PRINT
3884 Printing information about a FIT image adds quite a bit of
3885 code to SPL. So this is normally disabled in SPL. Use this
3886 option to re-enable it. This will affect the output of the
3887 bootm command when booting a FIT image.
3891 Enable building of TPL globally.
3894 Image offset to which the TPL should be padded before appending
3895 the TPL payload. By default, this is defined as
3896 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3897 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3898 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3903 [so far only for SMDK2400 boards]
3905 - Modem support enable:
3906 CONFIG_MODEM_SUPPORT
3908 - RTS/CTS Flow control enable:
3911 - Modem debug support:
3912 CONFIG_MODEM_SUPPORT_DEBUG
3914 Enables debugging stuff (char screen[1024], dbg())
3915 for modem support. Useful only with BDI2000.
3917 - Interrupt support (PPC):
3919 There are common interrupt_init() and timer_interrupt()
3920 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3921 for CPU specific initialization. interrupt_init_cpu()
3922 should set decrementer_count to appropriate value. If
3923 CPU resets decrementer automatically after interrupt
3924 (ppc4xx) it should set decrementer_count to zero.
3925 timer_interrupt() calls timer_interrupt_cpu() for CPU
3926 specific handling. If board has watchdog / status_led
3927 / other_activity_monitor it works automatically from
3928 general timer_interrupt().
3932 In the target system modem support is enabled when a
3933 specific key (key combination) is pressed during
3934 power-on. Otherwise U-Boot will boot normally
3935 (autoboot). The key_pressed() function is called from
3936 board_init(). Currently key_pressed() is a dummy
3937 function, returning 1 and thus enabling modem
3940 If there are no modem init strings in the
3941 environment, U-Boot proceed to autoboot; the
3942 previous output (banner, info printfs) will be
3945 See also: doc/README.Modem
3947 Board initialization settings:
3948 ------------------------------
3950 During Initialization u-boot calls a number of board specific functions
3951 to allow the preparation of board specific prerequisites, e.g. pin setup
3952 before drivers are initialized. To enable these callbacks the
3953 following configuration macros have to be defined. Currently this is
3954 architecture specific, so please check arch/your_architecture/lib/board.c
3955 typically in board_init_f() and board_init_r().
3957 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3958 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3959 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3960 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3962 Configuration Settings:
3963 -----------------------
3965 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3966 Optionally it can be defined to support 64-bit memory commands.
3968 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3969 undefine this when you're short of memory.
3971 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3972 width of the commands listed in the 'help' command output.
3974 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3975 prompt for user input.
3977 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3979 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3981 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3983 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3984 the application (usually a Linux kernel) when it is
3987 - CONFIG_SYS_BAUDRATE_TABLE:
3988 List of legal baudrate settings for this board.
3990 - CONFIG_SYS_CONSOLE_INFO_QUIET
3991 Suppress display of console information at boot.
3993 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3994 If the board specific function
3995 extern int overwrite_console (void);
3996 returns 1, the stdin, stderr and stdout are switched to the
3997 serial port, else the settings in the environment are used.
3999 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4000 Enable the call to overwrite_console().
4002 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4003 Enable overwrite of previous console environment settings.
4005 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4006 Begin and End addresses of the area used by the
4009 - CONFIG_SYS_ALT_MEMTEST:
4010 Enable an alternate, more extensive memory test.
4012 - CONFIG_SYS_MEMTEST_SCRATCH:
4013 Scratch address used by the alternate memory test
4014 You only need to set this if address zero isn't writeable
4016 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4017 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4018 this specified memory area will get subtracted from the top
4019 (end) of RAM and won't get "touched" at all by U-Boot. By
4020 fixing up gd->ram_size the Linux kernel should gets passed
4021 the now "corrected" memory size and won't touch it either.
4022 This should work for arch/ppc and arch/powerpc. Only Linux
4023 board ports in arch/powerpc with bootwrapper support that
4024 recalculate the memory size from the SDRAM controller setup
4025 will have to get fixed in Linux additionally.
4027 This option can be used as a workaround for the 440EPx/GRx
4028 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4031 WARNING: Please make sure that this value is a multiple of
4032 the Linux page size (normally 4k). If this is not the case,
4033 then the end address of the Linux memory will be located at a
4034 non page size aligned address and this could cause major
4037 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4038 Enable temporary baudrate change while serial download
4040 - CONFIG_SYS_SDRAM_BASE:
4041 Physical start address of SDRAM. _Must_ be 0 here.
4043 - CONFIG_SYS_MBIO_BASE:
4044 Physical start address of Motherboard I/O (if using a
4047 - CONFIG_SYS_FLASH_BASE:
4048 Physical start address of Flash memory.
4050 - CONFIG_SYS_MONITOR_BASE:
4051 Physical start address of boot monitor code (set by
4052 make config files to be same as the text base address
4053 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4054 CONFIG_SYS_FLASH_BASE when booting from flash.
4056 - CONFIG_SYS_MONITOR_LEN:
4057 Size of memory reserved for monitor code, used to
4058 determine _at_compile_time_ (!) if the environment is
4059 embedded within the U-Boot image, or in a separate
4062 - CONFIG_SYS_MALLOC_LEN:
4063 Size of DRAM reserved for malloc() use.
4065 - CONFIG_SYS_MALLOC_F_LEN
4066 Size of the malloc() pool for use before relocation. If
4067 this is defined, then a very simple malloc() implementation
4068 will become available before relocation. The address is just
4069 below the global data, and the stack is moved down to make
4072 This feature allocates regions with increasing addresses
4073 within the region. calloc() is supported, but realloc()
4074 is not available. free() is supported but does nothing.
4075 The memory will be freed (or in fact just forgotten) when
4076 U-Boot relocates itself.
4078 Pre-relocation malloc() is only supported on ARM and sandbox
4079 at present but is fairly easy to enable for other archs.
4081 - CONFIG_SYS_MALLOC_SIMPLE
4082 Provides a simple and small malloc() and calloc() for those
4083 boards which do not use the full malloc in SPL (which is
4084 enabled with CONFIG_SYS_SPL_MALLOC_START).
4086 - CONFIG_SYS_NONCACHED_MEMORY:
4087 Size of non-cached memory area. This area of memory will be
4088 typically located right below the malloc() area and mapped
4089 uncached in the MMU. This is useful for drivers that would
4090 otherwise require a lot of explicit cache maintenance. For
4091 some drivers it's also impossible to properly maintain the
4092 cache. For example if the regions that need to be flushed
4093 are not a multiple of the cache-line size, *and* padding
4094 cannot be allocated between the regions to align them (i.e.
4095 if the HW requires a contiguous array of regions, and the
4096 size of each region is not cache-aligned), then a flush of
4097 one region may result in overwriting data that hardware has
4098 written to another region in the same cache-line. This can
4099 happen for example in network drivers where descriptors for
4100 buffers are typically smaller than the CPU cache-line (e.g.
4101 16 bytes vs. 32 or 64 bytes).
4103 Non-cached memory is only supported on 32-bit ARM at present.
4105 - CONFIG_SYS_BOOTM_LEN:
4106 Normally compressed uImages are limited to an
4107 uncompressed size of 8 MBytes. If this is not enough,
4108 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4109 to adjust this setting to your needs.
4111 - CONFIG_SYS_BOOTMAPSZ:
4112 Maximum size of memory mapped by the startup code of
4113 the Linux kernel; all data that must be processed by
4114 the Linux kernel (bd_info, boot arguments, FDT blob if
4115 used) must be put below this limit, unless "bootm_low"
4116 environment variable is defined and non-zero. In such case
4117 all data for the Linux kernel must be between "bootm_low"
4118 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4119 variable "bootm_mapsize" will override the value of
4120 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4121 then the value in "bootm_size" will be used instead.
4123 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4124 Enable initrd_high functionality. If defined then the
4125 initrd_high feature is enabled and the bootm ramdisk subcommand
4128 - CONFIG_SYS_BOOT_GET_CMDLINE:
4129 Enables allocating and saving kernel cmdline in space between
4130 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4132 - CONFIG_SYS_BOOT_GET_KBD:
4133 Enables allocating and saving a kernel copy of the bd_info in
4134 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4136 - CONFIG_SYS_MAX_FLASH_BANKS:
4137 Max number of Flash memory banks
4139 - CONFIG_SYS_MAX_FLASH_SECT:
4140 Max number of sectors on a Flash chip
4142 - CONFIG_SYS_FLASH_ERASE_TOUT:
4143 Timeout for Flash erase operations (in ms)
4145 - CONFIG_SYS_FLASH_WRITE_TOUT:
4146 Timeout for Flash write operations (in ms)
4148 - CONFIG_SYS_FLASH_LOCK_TOUT
4149 Timeout for Flash set sector lock bit operation (in ms)
4151 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4152 Timeout for Flash clear lock bits operation (in ms)
4154 - CONFIG_SYS_FLASH_PROTECTION
4155 If defined, hardware flash sectors protection is used
4156 instead of U-Boot software protection.
4158 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4160 Enable TFTP transfers directly to flash memory;
4161 without this option such a download has to be
4162 performed in two steps: (1) download to RAM, and (2)
4163 copy from RAM to flash.
4165 The two-step approach is usually more reliable, since
4166 you can check if the download worked before you erase
4167 the flash, but in some situations (when system RAM is
4168 too limited to allow for a temporary copy of the
4169 downloaded image) this option may be very useful.
4171 - CONFIG_SYS_FLASH_CFI:
4172 Define if the flash driver uses extra elements in the
4173 common flash structure for storing flash geometry.
4175 - CONFIG_FLASH_CFI_DRIVER
4176 This option also enables the building of the cfi_flash driver
4177 in the drivers directory
4179 - CONFIG_FLASH_CFI_MTD
4180 This option enables the building of the cfi_mtd driver
4181 in the drivers directory. The driver exports CFI flash
4184 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4185 Use buffered writes to flash.
4187 - CONFIG_FLASH_SPANSION_S29WS_N
4188 s29ws-n MirrorBit flash has non-standard addresses for buffered
4191 - CONFIG_SYS_FLASH_QUIET_TEST
4192 If this option is defined, the common CFI flash doesn't
4193 print it's warning upon not recognized FLASH banks. This
4194 is useful, if some of the configured banks are only
4195 optionally available.
4197 - CONFIG_FLASH_SHOW_PROGRESS
4198 If defined (must be an integer), print out countdown
4199 digits and dots. Recommended value: 45 (9..1) for 80
4200 column displays, 15 (3..1) for 40 column displays.
4202 - CONFIG_FLASH_VERIFY
4203 If defined, the content of the flash (destination) is compared
4204 against the source after the write operation. An error message
4205 will be printed when the contents are not identical.
4206 Please note that this option is useless in nearly all cases,
4207 since such flash programming errors usually are detected earlier
4208 while unprotecting/erasing/programming. Please only enable
4209 this option if you really know what you are doing.
4211 - CONFIG_SYS_RX_ETH_BUFFER:
4212 Defines the number of Ethernet receive buffers. On some
4213 Ethernet controllers it is recommended to set this value
4214 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4215 buffers can be full shortly after enabling the interface
4216 on high Ethernet traffic.
4217 Defaults to 4 if not defined.
4219 - CONFIG_ENV_MAX_ENTRIES
4221 Maximum number of entries in the hash table that is used
4222 internally to store the environment settings. The default
4223 setting is supposed to be generous and should work in most
4224 cases. This setting can be used to tune behaviour; see
4225 lib/hashtable.c for details.
4227 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4228 - CONFIG_ENV_FLAGS_LIST_STATIC
4229 Enable validation of the values given to environment variables when
4230 calling env set. Variables can be restricted to only decimal,
4231 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4232 the variables can also be restricted to IP address or MAC address.
4234 The format of the list is:
4235 type_attribute = [s|d|x|b|i|m]
4236 access_attribute = [a|r|o|c]
4237 attributes = type_attribute[access_attribute]
4238 entry = variable_name[:attributes]
4241 The type attributes are:
4242 s - String (default)
4245 b - Boolean ([1yYtT|0nNfF])
4249 The access attributes are:
4255 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4256 Define this to a list (string) to define the ".flags"
4257 environment variable in the default or embedded environment.
4259 - CONFIG_ENV_FLAGS_LIST_STATIC
4260 Define this to a list (string) to define validation that
4261 should be done if an entry is not found in the ".flags"
4262 environment variable. To override a setting in the static
4263 list, simply add an entry for the same variable name to the
4266 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4267 regular expression. This allows multiple variables to define the same
4268 flags without explicitly listing them for each variable.
4270 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4271 If defined, don't allow the -f switch to env set override variable
4274 - CONFIG_SYS_GENERIC_BOARD
4275 This selects the architecture-generic board system instead of the
4276 architecture-specific board files. It is intended to move boards
4277 to this new framework over time. Defining this will disable the
4278 arch/foo/lib/board.c file and use common/board_f.c and
4279 common/board_r.c instead. To use this option your architecture
4280 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4281 If you find problems enabling this option on your board please report
4282 the problem and send patches!
4284 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4285 This is set by OMAP boards for the max time that reset should
4286 be asserted. See doc/README.omap-reset-time for details on how
4287 the value can be calculated on a given board.
4290 If stdint.h is available with your toolchain you can define this
4291 option to enable it. You can provide option 'USE_STDINT=1' when
4292 building U-Boot to enable this.
4294 The following definitions that deal with the placement and management
4295 of environment data (variable area); in general, we support the
4296 following configurations:
4298 - CONFIG_BUILD_ENVCRC:
4300 Builds up envcrc with the target environment so that external utils
4301 may easily extract it and embed it in final U-Boot images.
4303 - CONFIG_ENV_IS_IN_FLASH:
4305 Define this if the environment is in flash memory.
4307 a) The environment occupies one whole flash sector, which is
4308 "embedded" in the text segment with the U-Boot code. This
4309 happens usually with "bottom boot sector" or "top boot
4310 sector" type flash chips, which have several smaller
4311 sectors at the start or the end. For instance, such a
4312 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4313 such a case you would place the environment in one of the
4314 4 kB sectors - with U-Boot code before and after it. With
4315 "top boot sector" type flash chips, you would put the
4316 environment in one of the last sectors, leaving a gap
4317 between U-Boot and the environment.
4319 - CONFIG_ENV_OFFSET:
4321 Offset of environment data (variable area) to the
4322 beginning of flash memory; for instance, with bottom boot
4323 type flash chips the second sector can be used: the offset
4324 for this sector is given here.
4326 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4330 This is just another way to specify the start address of
4331 the flash sector containing the environment (instead of
4334 - CONFIG_ENV_SECT_SIZE:
4336 Size of the sector containing the environment.
4339 b) Sometimes flash chips have few, equal sized, BIG sectors.
4340 In such a case you don't want to spend a whole sector for
4345 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4346 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4347 of this flash sector for the environment. This saves
4348 memory for the RAM copy of the environment.
4350 It may also save flash memory if you decide to use this
4351 when your environment is "embedded" within U-Boot code,
4352 since then the remainder of the flash sector could be used
4353 for U-Boot code. It should be pointed out that this is
4354 STRONGLY DISCOURAGED from a robustness point of view:
4355 updating the environment in flash makes it always
4356 necessary to erase the WHOLE sector. If something goes
4357 wrong before the contents has been restored from a copy in
4358 RAM, your target system will be dead.
4360 - CONFIG_ENV_ADDR_REDUND
4361 CONFIG_ENV_SIZE_REDUND
4363 These settings describe a second storage area used to hold
4364 a redundant copy of the environment data, so that there is
4365 a valid backup copy in case there is a power failure during
4366 a "saveenv" operation.
4368 BE CAREFUL! Any changes to the flash layout, and some changes to the
4369 source code will make it necessary to adapt <board>/u-boot.lds*
4373 - CONFIG_ENV_IS_IN_NVRAM:
4375 Define this if you have some non-volatile memory device
4376 (NVRAM, battery buffered SRAM) which you want to use for the
4382 These two #defines are used to determine the memory area you
4383 want to use for environment. It is assumed that this memory
4384 can just be read and written to, without any special
4387 BE CAREFUL! The first access to the environment happens quite early
4388 in U-Boot initialization (when we try to get the setting of for the
4389 console baudrate). You *MUST* have mapped your NVRAM area then, or
4392 Please note that even with NVRAM we still use a copy of the
4393 environment in RAM: we could work on NVRAM directly, but we want to
4394 keep settings there always unmodified except somebody uses "saveenv"
4395 to save the current settings.
4398 - CONFIG_ENV_IS_IN_EEPROM:
4400 Use this if you have an EEPROM or similar serial access
4401 device and a driver for it.
4403 - CONFIG_ENV_OFFSET:
4406 These two #defines specify the offset and size of the
4407 environment area within the total memory of your EEPROM.
4409 - CONFIG_SYS_I2C_EEPROM_ADDR:
4410 If defined, specified the chip address of the EEPROM device.
4411 The default address is zero.
4413 - CONFIG_SYS_I2C_EEPROM_BUS:
4414 If defined, specified the i2c bus of the EEPROM device.
4416 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4417 If defined, the number of bits used to address bytes in a
4418 single page in the EEPROM device. A 64 byte page, for example
4419 would require six bits.
4421 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4422 If defined, the number of milliseconds to delay between
4423 page writes. The default is zero milliseconds.
4425 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4426 The length in bytes of the EEPROM memory array address. Note
4427 that this is NOT the chip address length!
4429 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4430 EEPROM chips that implement "address overflow" are ones
4431 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4432 address and the extra bits end up in the "chip address" bit
4433 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4436 Note that we consider the length of the address field to
4437 still be one byte because the extra address bits are hidden
4438 in the chip address.
4440 - CONFIG_SYS_EEPROM_SIZE:
4441 The size in bytes of the EEPROM device.
4443 - CONFIG_ENV_EEPROM_IS_ON_I2C
4444 define this, if you have I2C and SPI activated, and your
4445 EEPROM, which holds the environment, is on the I2C bus.
4447 - CONFIG_I2C_ENV_EEPROM_BUS
4448 if you have an Environment on an EEPROM reached over
4449 I2C muxes, you can define here, how to reach this
4450 EEPROM. For example:
4452 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4454 EEPROM which holds the environment, is reached over
4455 a pca9547 i2c mux with address 0x70, channel 3.
4457 - CONFIG_ENV_IS_IN_DATAFLASH:
4459 Define this if you have a DataFlash memory device which you
4460 want to use for the environment.
4462 - CONFIG_ENV_OFFSET:
4466 These three #defines specify the offset and size of the
4467 environment area within the total memory of your DataFlash placed
4468 at the specified address.
4470 - CONFIG_ENV_IS_IN_SPI_FLASH:
4472 Define this if you have a SPI Flash memory device which you
4473 want to use for the environment.
4475 - CONFIG_ENV_OFFSET:
4478 These two #defines specify the offset and size of the
4479 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4480 aligned to an erase sector boundary.
4482 - CONFIG_ENV_SECT_SIZE:
4484 Define the SPI flash's sector size.
4486 - CONFIG_ENV_OFFSET_REDUND (optional):
4488 This setting describes a second storage area of CONFIG_ENV_SIZE
4489 size used to hold a redundant copy of the environment data, so
4490 that there is a valid backup copy in case there is a power failure
4491 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4492 aligned to an erase sector boundary.
4494 - CONFIG_ENV_SPI_BUS (optional):
4495 - CONFIG_ENV_SPI_CS (optional):
4497 Define the SPI bus and chip select. If not defined they will be 0.
4499 - CONFIG_ENV_SPI_MAX_HZ (optional):
4501 Define the SPI max work clock. If not defined then use 1MHz.
4503 - CONFIG_ENV_SPI_MODE (optional):
4505 Define the SPI work mode. If not defined then use SPI_MODE_3.
4507 - CONFIG_ENV_IS_IN_REMOTE:
4509 Define this if you have a remote memory space which you
4510 want to use for the local device's environment.
4515 These two #defines specify the address and size of the
4516 environment area within the remote memory space. The
4517 local device can get the environment from remote memory
4518 space by SRIO or PCIE links.
4520 BE CAREFUL! For some special cases, the local device can not use
4521 "saveenv" command. For example, the local device will get the
4522 environment stored in a remote NOR flash by SRIO or PCIE link,
4523 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4525 - CONFIG_ENV_IS_IN_NAND:
4527 Define this if you have a NAND device which you want to use
4528 for the environment.
4530 - CONFIG_ENV_OFFSET:
4533 These two #defines specify the offset and size of the environment
4534 area within the first NAND device. CONFIG_ENV_OFFSET must be
4535 aligned to an erase block boundary.
4537 - CONFIG_ENV_OFFSET_REDUND (optional):
4539 This setting describes a second storage area of CONFIG_ENV_SIZE
4540 size used to hold a redundant copy of the environment data, so
4541 that there is a valid backup copy in case there is a power failure
4542 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4543 aligned to an erase block boundary.
4545 - CONFIG_ENV_RANGE (optional):
4547 Specifies the length of the region in which the environment
4548 can be written. This should be a multiple of the NAND device's
4549 block size. Specifying a range with more erase blocks than
4550 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4551 the range to be avoided.
4553 - CONFIG_ENV_OFFSET_OOB (optional):
4555 Enables support for dynamically retrieving the offset of the
4556 environment from block zero's out-of-band data. The
4557 "nand env.oob" command can be used to record this offset.
4558 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4559 using CONFIG_ENV_OFFSET_OOB.
4561 - CONFIG_NAND_ENV_DST
4563 Defines address in RAM to which the nand_spl code should copy the
4564 environment. If redundant environment is used, it will be copied to
4565 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4567 - CONFIG_ENV_IS_IN_UBI:
4569 Define this if you have an UBI volume that you want to use for the
4570 environment. This has the benefit of wear-leveling the environment
4571 accesses, which is important on NAND.
4573 - CONFIG_ENV_UBI_PART:
4575 Define this to a string that is the mtd partition containing the UBI.
4577 - CONFIG_ENV_UBI_VOLUME:
4579 Define this to the name of the volume that you want to store the
4582 - CONFIG_ENV_UBI_VOLUME_REDUND:
4584 Define this to the name of another volume to store a second copy of
4585 the environment in. This will enable redundant environments in UBI.
4586 It is assumed that both volumes are in the same MTD partition.
4588 - CONFIG_UBI_SILENCE_MSG
4589 - CONFIG_UBIFS_SILENCE_MSG
4591 You will probably want to define these to avoid a really noisy system
4592 when storing the env in UBI.
4594 - CONFIG_ENV_IS_IN_FAT:
4595 Define this if you want to use the FAT file system for the environment.
4597 - FAT_ENV_INTERFACE:
4599 Define this to a string that is the name of the block device.
4601 - FAT_ENV_DEV_AND_PART:
4603 Define this to a string to specify the partition of the device. It can
4606 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4607 - "D:P": device D partition P. Error occurs if device D has no
4610 - "D" or "D:": device D partition 1 if device D has partition
4611 table, or the whole device D if has no partition
4613 - "D:auto": first partition in device D with bootable flag set.
4614 If none, first valid partition in device D. If no
4615 partition table then means device D.
4619 It's a string of the FAT file name. This file use to store the
4623 This should be defined. Otherwise it cannot save the environment file.
4625 - CONFIG_ENV_IS_IN_MMC:
4627 Define this if you have an MMC device which you want to use for the
4630 - CONFIG_SYS_MMC_ENV_DEV:
4632 Specifies which MMC device the environment is stored in.
4634 - CONFIG_SYS_MMC_ENV_PART (optional):
4636 Specifies which MMC partition the environment is stored in. If not
4637 set, defaults to partition 0, the user area. Common values might be
4638 1 (first MMC boot partition), 2 (second MMC boot partition).
4640 - CONFIG_ENV_OFFSET:
4643 These two #defines specify the offset and size of the environment
4644 area within the specified MMC device.
4646 If offset is positive (the usual case), it is treated as relative to
4647 the start of the MMC partition. If offset is negative, it is treated
4648 as relative to the end of the MMC partition. This can be useful if
4649 your board may be fitted with different MMC devices, which have
4650 different sizes for the MMC partitions, and you always want the
4651 environment placed at the very end of the partition, to leave the
4652 maximum possible space before it, to store other data.
4654 These two values are in units of bytes, but must be aligned to an
4655 MMC sector boundary.
4657 - CONFIG_ENV_OFFSET_REDUND (optional):
4659 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4660 hold a redundant copy of the environment data. This provides a
4661 valid backup copy in case the other copy is corrupted, e.g. due
4662 to a power failure during a "saveenv" operation.
4664 This value may also be positive or negative; this is handled in the
4665 same way as CONFIG_ENV_OFFSET.
4667 This value is also in units of bytes, but must also be aligned to
4668 an MMC sector boundary.
4670 - CONFIG_ENV_SIZE_REDUND (optional):
4672 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4673 set. If this value is set, it must be set to the same value as
4676 - CONFIG_SYS_SPI_INIT_OFFSET
4678 Defines offset to the initial SPI buffer area in DPRAM. The
4679 area is used at an early stage (ROM part) if the environment
4680 is configured to reside in the SPI EEPROM: We need a 520 byte
4681 scratch DPRAM area. It is used between the two initialization
4682 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4683 to be a good choice since it makes it far enough from the
4684 start of the data area as well as from the stack pointer.
4686 Please note that the environment is read-only until the monitor
4687 has been relocated to RAM and a RAM copy of the environment has been
4688 created; also, when using EEPROM you will have to use getenv_f()
4689 until then to read environment variables.
4691 The environment is protected by a CRC32 checksum. Before the monitor
4692 is relocated into RAM, as a result of a bad CRC you will be working
4693 with the compiled-in default environment - *silently*!!! [This is
4694 necessary, because the first environment variable we need is the
4695 "baudrate" setting for the console - if we have a bad CRC, we don't
4696 have any device yet where we could complain.]
4698 Note: once the monitor has been relocated, then it will complain if
4699 the default environment is used; a new CRC is computed as soon as you
4700 use the "saveenv" command to store a valid environment.
4702 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4703 Echo the inverted Ethernet link state to the fault LED.
4705 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4706 also needs to be defined.
4708 - CONFIG_SYS_FAULT_MII_ADDR:
4709 MII address of the PHY to check for the Ethernet link state.
4711 - CONFIG_NS16550_MIN_FUNCTIONS:
4712 Define this if you desire to only have use of the NS16550_init
4713 and NS16550_putc functions for the serial driver located at
4714 drivers/serial/ns16550.c. This option is useful for saving
4715 space for already greatly restricted images, including but not
4716 limited to NAND_SPL configurations.
4718 - CONFIG_DISPLAY_BOARDINFO
4719 Display information about the board that U-Boot is running on
4720 when U-Boot starts up. The board function checkboard() is called
4723 - CONFIG_DISPLAY_BOARDINFO_LATE
4724 Similar to the previous option, but display this information
4725 later, once stdio is running and output goes to the LCD, if
4728 - CONFIG_BOARD_SIZE_LIMIT:
4729 Maximum size of the U-Boot image. When defined, the
4730 build system checks that the actual size does not
4733 Low Level (hardware related) configuration options:
4734 ---------------------------------------------------
4736 - CONFIG_SYS_CACHELINE_SIZE:
4737 Cache Line Size of the CPU.
4739 - CONFIG_SYS_DEFAULT_IMMR:
4740 Default address of the IMMR after system reset.
4742 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4743 and RPXsuper) to be able to adjust the position of
4744 the IMMR register after a reset.
4746 - CONFIG_SYS_CCSRBAR_DEFAULT:
4747 Default (power-on reset) physical address of CCSR on Freescale
4750 - CONFIG_SYS_CCSRBAR:
4751 Virtual address of CCSR. On a 32-bit build, this is typically
4752 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4754 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4755 for cross-platform code that uses that macro instead.
4757 - CONFIG_SYS_CCSRBAR_PHYS:
4758 Physical address of CCSR. CCSR can be relocated to a new
4759 physical address, if desired. In this case, this macro should
4760 be set to that address. Otherwise, it should be set to the
4761 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4762 is typically relocated on 36-bit builds. It is recommended
4763 that this macro be defined via the _HIGH and _LOW macros:
4765 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4766 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4768 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4769 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4770 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4771 used in assembly code, so it must not contain typecasts or
4772 integer size suffixes (e.g. "ULL").
4774 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4775 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4776 used in assembly code, so it must not contain typecasts or
4777 integer size suffixes (e.g. "ULL").
4779 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4780 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4781 forced to a value that ensures that CCSR is not relocated.
4783 - Floppy Disk Support:
4784 CONFIG_SYS_FDC_DRIVE_NUMBER
4786 the default drive number (default value 0)
4788 CONFIG_SYS_ISA_IO_STRIDE
4790 defines the spacing between FDC chipset registers
4793 CONFIG_SYS_ISA_IO_OFFSET
4795 defines the offset of register from address. It
4796 depends on which part of the data bus is connected to
4797 the FDC chipset. (default value 0)
4799 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4800 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4803 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4804 fdc_hw_init() is called at the beginning of the FDC
4805 setup. fdc_hw_init() must be provided by the board
4806 source code. It is used to make hardware-dependent
4810 Most IDE controllers were designed to be connected with PCI
4811 interface. Only few of them were designed for AHB interface.
4812 When software is doing ATA command and data transfer to
4813 IDE devices through IDE-AHB controller, some additional
4814 registers accessing to these kind of IDE-AHB controller
4817 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4818 DO NOT CHANGE unless you know exactly what you're
4819 doing! (11-4) [MPC8xx/82xx systems only]
4821 - CONFIG_SYS_INIT_RAM_ADDR:
4823 Start address of memory area that can be used for
4824 initial data and stack; please note that this must be
4825 writable memory that is working WITHOUT special
4826 initialization, i. e. you CANNOT use normal RAM which
4827 will become available only after programming the
4828 memory controller and running certain initialization
4831 U-Boot uses the following memory types:
4832 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4833 - MPC824X: data cache
4834 - PPC4xx: data cache
4836 - CONFIG_SYS_GBL_DATA_OFFSET:
4838 Offset of the initial data structure in the memory
4839 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4840 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4841 data is located at the end of the available space
4842 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4843 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4844 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4845 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4848 On the MPC824X (or other systems that use the data
4849 cache for initial memory) the address chosen for
4850 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4851 point to an otherwise UNUSED address space between
4852 the top of RAM and the start of the PCI space.
4854 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4856 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4858 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4860 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4862 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4864 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4866 - CONFIG_SYS_OR_TIMING_SDRAM:
4869 - CONFIG_SYS_MAMR_PTA:
4870 periodic timer for refresh
4872 - CONFIG_SYS_DER: Debug Event Register (37-47)
4874 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4875 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4876 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4877 CONFIG_SYS_BR1_PRELIM:
4878 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4880 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4881 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4882 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4883 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4885 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4886 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4887 Machine Mode Register and Memory Periodic Timer
4888 Prescaler definitions (SDRAM timing)
4890 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4891 enable I2C microcode relocation patch (MPC8xx);
4892 define relocation offset in DPRAM [DSP2]
4894 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4895 enable SMC microcode relocation patch (MPC8xx);
4896 define relocation offset in DPRAM [SMC1]
4898 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4899 enable SPI microcode relocation patch (MPC8xx);
4900 define relocation offset in DPRAM [SCC4]
4902 - CONFIG_SYS_USE_OSCCLK:
4903 Use OSCM clock mode on MBX8xx board. Be careful,
4904 wrong setting might damage your board. Read
4905 doc/README.MBX before setting this variable!
4907 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4908 Offset of the bootmode word in DPRAM used by post
4909 (Power On Self Tests). This definition overrides
4910 #define'd default value in commproc.h resp.
4913 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4914 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4915 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4916 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4917 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4918 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4919 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4920 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4921 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4923 - CONFIG_PCI_DISABLE_PCIE:
4924 Disable PCI-Express on systems where it is supported but not
4927 - CONFIG_PCI_ENUM_ONLY
4928 Only scan through and get the devices on the buses.
4929 Don't do any setup work, presumably because someone or
4930 something has already done it, and we don't need to do it
4931 a second time. Useful for platforms that are pre-booted
4932 by coreboot or similar.
4934 - CONFIG_PCI_INDIRECT_BRIDGE:
4935 Enable support for indirect PCI bridges.
4938 Chip has SRIO or not
4941 Board has SRIO 1 port available
4944 Board has SRIO 2 port available
4946 - CONFIG_SRIO_PCIE_BOOT_MASTER
4947 Board can support master function for Boot from SRIO and PCIE
4949 - CONFIG_SYS_SRIOn_MEM_VIRT:
4950 Virtual Address of SRIO port 'n' memory region
4952 - CONFIG_SYS_SRIOn_MEM_PHYS:
4953 Physical Address of SRIO port 'n' memory region
4955 - CONFIG_SYS_SRIOn_MEM_SIZE:
4956 Size of SRIO port 'n' memory region
4958 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4959 Defined to tell the NAND controller that the NAND chip is using
4961 Not all NAND drivers use this symbol.
4962 Example of drivers that use it:
4963 - drivers/mtd/nand/ndfc.c
4964 - drivers/mtd/nand/mxc_nand.c
4966 - CONFIG_SYS_NDFC_EBC0_CFG
4967 Sets the EBC0_CFG register for the NDFC. If not defined
4968 a default value will be used.
4971 Get DDR timing information from an I2C EEPROM. Common
4972 with pluggable memory modules such as SODIMMs
4975 I2C address of the SPD EEPROM
4977 - CONFIG_SYS_SPD_BUS_NUM
4978 If SPD EEPROM is on an I2C bus other than the first
4979 one, specify here. Note that the value must resolve
4980 to something your driver can deal with.
4982 - CONFIG_SYS_DDR_RAW_TIMING
4983 Get DDR timing information from other than SPD. Common with
4984 soldered DDR chips onboard without SPD. DDR raw timing
4985 parameters are extracted from datasheet and hard-coded into
4986 header files or board specific files.
4988 - CONFIG_FSL_DDR_INTERACTIVE
4989 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4991 - CONFIG_FSL_DDR_SYNC_REFRESH
4992 Enable sync of refresh for multiple controllers.
4994 - CONFIG_FSL_DDR_BIST
4995 Enable built-in memory test for Freescale DDR controllers.
4997 - CONFIG_SYS_83XX_DDR_USES_CS0
4998 Only for 83xx systems. If specified, then DDR should
4999 be configured using CS0 and CS1 instead of CS2 and CS3.
5001 - CONFIG_ETHER_ON_FEC[12]
5002 Define to enable FEC[12] on a 8xx series processor.
5004 - CONFIG_FEC[12]_PHY
5005 Define to the hardcoded PHY address which corresponds
5006 to the given FEC; i. e.
5007 #define CONFIG_FEC1_PHY 4
5008 means that the PHY with address 4 is connected to FEC1
5010 When set to -1, means to probe for first available.
5012 - CONFIG_FEC[12]_PHY_NORXERR
5013 The PHY does not have a RXERR line (RMII only).
5014 (so program the FEC to ignore it).
5017 Enable RMII mode for all FECs.
5018 Note that this is a global option, we can't
5019 have one FEC in standard MII mode and another in RMII mode.
5021 - CONFIG_CRC32_VERIFY
5022 Add a verify option to the crc32 command.
5025 => crc32 -v <address> <count> <crc32>
5027 Where address/count indicate a memory area
5028 and crc32 is the correct crc32 which the
5032 Add the "loopw" memory command. This only takes effect if
5033 the memory commands are activated globally (CONFIG_CMD_MEM).
5036 Add the "mdc" and "mwc" memory commands. These are cyclic
5041 This command will print 4 bytes (10,11,12,13) each 500 ms.
5043 => mwc.l 100 12345678 10
5044 This command will write 12345678 to address 100 all 10 ms.
5046 This only takes effect if the memory commands are activated
5047 globally (CONFIG_CMD_MEM).
5049 - CONFIG_SKIP_LOWLEVEL_INIT
5050 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5051 low level initializations (like setting up the memory
5052 controller) are omitted and/or U-Boot does not
5053 relocate itself into RAM.
5055 Normally this variable MUST NOT be defined. The only
5056 exception is when U-Boot is loaded (to RAM) by some
5057 other boot loader or by a debugger which performs
5058 these initializations itself.
5061 Modifies the behaviour of start.S when compiling a loader
5062 that is executed before the actual U-Boot. E.g. when
5063 compiling a NAND SPL.
5066 Modifies the behaviour of start.S when compiling a loader
5067 that is executed after the SPL and before the actual U-Boot.
5068 It is loaded by the SPL.
5070 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5071 Only for 85xx systems. If this variable is specified, the section
5072 .resetvec is not kept and the section .bootpg is placed in the
5073 previous 4k of the .text section.
5075 - CONFIG_ARCH_MAP_SYSMEM
5076 Generally U-Boot (and in particular the md command) uses
5077 effective address. It is therefore not necessary to regard
5078 U-Boot address as virtual addresses that need to be translated
5079 to physical addresses. However, sandbox requires this, since
5080 it maintains its own little RAM buffer which contains all
5081 addressable memory. This option causes some memory accesses
5082 to be mapped through map_sysmem() / unmap_sysmem().
5084 - CONFIG_USE_ARCH_MEMCPY
5085 CONFIG_USE_ARCH_MEMSET
5086 If these options are used a optimized version of memcpy/memset will
5087 be used if available. These functions may be faster under some
5088 conditions but may increase the binary size.
5090 - CONFIG_X86_RESET_VECTOR
5091 If defined, the x86 reset vector code is included. This is not
5092 needed when U-Boot is running from Coreboot.
5095 Defines the MPU clock speed (in MHz).
5097 NOTE : currently only supported on AM335x platforms.
5099 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5100 Enables the RTC32K OSC on AM33xx based plattforms
5102 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5103 Option to disable subpage write in NAND driver
5104 driver that uses this:
5105 drivers/mtd/nand/davinci_nand.c
5107 Freescale QE/FMAN Firmware Support:
5108 -----------------------------------
5110 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5111 loading of "firmware", which is encoded in the QE firmware binary format.
5112 This firmware often needs to be loaded during U-Boot booting, so macros
5113 are used to identify the storage device (NOR flash, SPI, etc) and the address
5116 - CONFIG_SYS_FMAN_FW_ADDR
5117 The address in the storage device where the FMAN microcode is located. The
5118 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5121 - CONFIG_SYS_QE_FW_ADDR
5122 The address in the storage device where the QE microcode is located. The
5123 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5126 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5127 The maximum possible size of the firmware. The firmware binary format
5128 has a field that specifies the actual size of the firmware, but it
5129 might not be possible to read any part of the firmware unless some
5130 local storage is allocated to hold the entire firmware first.
5132 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5133 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5134 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5135 virtual address in NOR flash.
5137 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5138 Specifies that QE/FMAN firmware is located in NAND flash.
5139 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5141 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5142 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5143 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5145 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5146 Specifies that QE/FMAN firmware is located on the primary SPI
5147 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5149 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5150 Specifies that QE/FMAN firmware is located in the remote (master)
5151 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5152 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5153 window->master inbound window->master LAW->the ucode address in
5154 master's memory space.
5156 Freescale Layerscape Management Complex Firmware Support:
5157 ---------------------------------------------------------
5158 The Freescale Layerscape Management Complex (MC) supports the loading of
5160 This firmware often needs to be loaded during U-Boot booting, so macros
5161 are used to identify the storage device (NOR flash, SPI, etc) and the address
5164 - CONFIG_FSL_MC_ENET
5165 Enable the MC driver for Layerscape SoCs.
5167 - CONFIG_SYS_LS_MC_FW_ADDR
5168 The address in the storage device where the firmware is located. The
5169 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5172 - CONFIG_SYS_LS_MC_FW_LENGTH
5173 The maximum possible size of the firmware. The firmware binary format
5174 has a field that specifies the actual size of the firmware, but it
5175 might not be possible to read any part of the firmware unless some
5176 local storage is allocated to hold the entire firmware first.
5178 - CONFIG_SYS_LS_MC_FW_IN_NOR
5179 Specifies that MC firmware is located in NOR flash, mapped as
5180 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5181 virtual address in NOR flash.
5183 Building the Software:
5184 ======================
5186 Building U-Boot has been tested in several native build environments
5187 and in many different cross environments. Of course we cannot support
5188 all possibly existing versions of cross development tools in all
5189 (potentially obsolete) versions. In case of tool chain problems we
5190 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5191 which is extensively used to build and test U-Boot.
5193 If you are not using a native environment, it is assumed that you
5194 have GNU cross compiling tools available in your path. In this case,
5195 you must set the environment variable CROSS_COMPILE in your shell.
5196 Note that no changes to the Makefile or any other source files are
5197 necessary. For example using the ELDK on a 4xx CPU, please enter:
5199 $ CROSS_COMPILE=ppc_4xx-
5200 $ export CROSS_COMPILE
5202 Note: If you wish to generate Windows versions of the utilities in
5203 the tools directory you can use the MinGW toolchain
5204 (http://www.mingw.org). Set your HOST tools to the MinGW
5205 toolchain and execute 'make tools'. For example:
5207 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5209 Binaries such as tools/mkimage.exe will be created which can
5210 be executed on computers running Windows.
5212 U-Boot is intended to be simple to build. After installing the
5213 sources you must configure U-Boot for one specific board type. This
5218 where "NAME_defconfig" is the name of one of the existing configu-
5219 rations; see boards.cfg for supported names.
5221 Note: for some board special configuration names may exist; check if
5222 additional information is available from the board vendor; for
5223 instance, the TQM823L systems are available without (standard)
5224 or with LCD support. You can select such additional "features"
5225 when choosing the configuration, i. e.
5227 make TQM823L_defconfig
5228 - will configure for a plain TQM823L, i. e. no LCD support
5230 make TQM823L_LCD_defconfig
5231 - will configure for a TQM823L with U-Boot console on LCD
5236 Finally, type "make all", and you should get some working U-Boot
5237 images ready for download to / installation on your system:
5239 - "u-boot.bin" is a raw binary image
5240 - "u-boot" is an image in ELF binary format
5241 - "u-boot.srec" is in Motorola S-Record format
5243 By default the build is performed locally and the objects are saved
5244 in the source directory. One of the two methods can be used to change
5245 this behavior and build U-Boot to some external directory:
5247 1. Add O= to the make command line invocations:
5249 make O=/tmp/build distclean
5250 make O=/tmp/build NAME_defconfig
5251 make O=/tmp/build all
5253 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5255 export KBUILD_OUTPUT=/tmp/build
5260 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5264 Please be aware that the Makefiles assume you are using GNU make, so
5265 for instance on NetBSD you might need to use "gmake" instead of
5269 If the system board that you have is not listed, then you will need
5270 to port U-Boot to your hardware platform. To do this, follow these
5273 1. Add a new configuration option for your board to the toplevel
5274 "boards.cfg" file, using the existing entries as examples.
5275 Follow the instructions there to keep the boards in order.
5276 2. Create a new directory to hold your board specific code. Add any
5277 files you need. In your board directory, you will need at least
5278 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5279 3. Create a new configuration file "include/configs/<board>.h" for
5281 3. If you're porting U-Boot to a new CPU, then also create a new
5282 directory to hold your CPU specific code. Add any files you need.
5283 4. Run "make <board>_defconfig" with your new name.
5284 5. Type "make", and you should get a working "u-boot.srec" file
5285 to be installed on your target system.
5286 6. Debug and solve any problems that might arise.
5287 [Of course, this last step is much harder than it sounds.]
5290 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5291 ==============================================================
5293 If you have modified U-Boot sources (for instance added a new board
5294 or support for new devices, a new CPU, etc.) you are expected to
5295 provide feedback to the other developers. The feedback normally takes
5296 the form of a "patch", i. e. a context diff against a certain (latest
5297 official or latest in the git repository) version of U-Boot sources.
5299 But before you submit such a patch, please verify that your modifi-
5300 cation did not break existing code. At least make sure that *ALL* of
5301 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5302 just run the "MAKEALL" script, which will configure and build U-Boot
5303 for ALL supported system. Be warned, this will take a while. You can
5304 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5305 environment variable to the script, i. e. to use the ELDK cross tools
5308 CROSS_COMPILE=ppc_8xx- MAKEALL
5310 or to build on a native PowerPC system you can type
5312 CROSS_COMPILE=' ' MAKEALL
5314 When using the MAKEALL script, the default behaviour is to build
5315 U-Boot in the source directory. This location can be changed by
5316 setting the BUILD_DIR environment variable. Also, for each target
5317 built, the MAKEALL script saves two log files (<target>.ERR and
5318 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5319 location can be changed by setting the MAKEALL_LOGDIR environment
5320 variable. For example:
5322 export BUILD_DIR=/tmp/build
5323 export MAKEALL_LOGDIR=/tmp/log
5324 CROSS_COMPILE=ppc_8xx- MAKEALL
5326 With the above settings build objects are saved in the /tmp/build,
5327 log files are saved in the /tmp/log and the source tree remains clean
5328 during the whole build process.
5331 See also "U-Boot Porting Guide" below.
5334 Monitor Commands - Overview:
5335 ============================
5337 go - start application at address 'addr'
5338 run - run commands in an environment variable
5339 bootm - boot application image from memory
5340 bootp - boot image via network using BootP/TFTP protocol
5341 bootz - boot zImage from memory
5342 tftpboot- boot image via network using TFTP protocol
5343 and env variables "ipaddr" and "serverip"
5344 (and eventually "gatewayip")
5345 tftpput - upload a file via network using TFTP protocol
5346 rarpboot- boot image via network using RARP/TFTP protocol
5347 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5348 loads - load S-Record file over serial line
5349 loadb - load binary file over serial line (kermit mode)
5351 mm - memory modify (auto-incrementing)
5352 nm - memory modify (constant address)
5353 mw - memory write (fill)
5355 cmp - memory compare
5356 crc32 - checksum calculation
5357 i2c - I2C sub-system
5358 sspi - SPI utility commands
5359 base - print or set address offset
5360 printenv- print environment variables
5361 setenv - set environment variables
5362 saveenv - save environment variables to persistent storage
5363 protect - enable or disable FLASH write protection
5364 erase - erase FLASH memory
5365 flinfo - print FLASH memory information
5366 nand - NAND memory operations (see doc/README.nand)
5367 bdinfo - print Board Info structure
5368 iminfo - print header information for application image
5369 coninfo - print console devices and informations
5370 ide - IDE sub-system
5371 loop - infinite loop on address range
5372 loopw - infinite write loop on address range
5373 mtest - simple RAM test
5374 icache - enable or disable instruction cache
5375 dcache - enable or disable data cache
5376 reset - Perform RESET of the CPU
5377 echo - echo args to console
5378 version - print monitor version
5379 help - print online help
5380 ? - alias for 'help'
5383 Monitor Commands - Detailed Description:
5384 ========================================
5388 For now: just type "help <command>".
5391 Environment Variables:
5392 ======================
5394 U-Boot supports user configuration using Environment Variables which
5395 can be made persistent by saving to Flash memory.
5397 Environment Variables are set using "setenv", printed using
5398 "printenv", and saved to Flash using "saveenv". Using "setenv"
5399 without a value can be used to delete a variable from the
5400 environment. As long as you don't save the environment you are
5401 working with an in-memory copy. In case the Flash area containing the
5402 environment is erased by accident, a default environment is provided.
5404 Some configuration options can be set using Environment Variables.
5406 List of environment variables (most likely not complete):
5408 baudrate - see CONFIG_BAUDRATE
5410 bootdelay - see CONFIG_BOOTDELAY
5412 bootcmd - see CONFIG_BOOTCOMMAND
5414 bootargs - Boot arguments when booting an RTOS image
5416 bootfile - Name of the image to load with TFTP
5418 bootm_low - Memory range available for image processing in the bootm
5419 command can be restricted. This variable is given as
5420 a hexadecimal number and defines lowest address allowed
5421 for use by the bootm command. See also "bootm_size"
5422 environment variable. Address defined by "bootm_low" is
5423 also the base of the initial memory mapping for the Linux
5424 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5427 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5428 This variable is given as a hexadecimal number and it
5429 defines the size of the memory region starting at base
5430 address bootm_low that is accessible by the Linux kernel
5431 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5432 as the default value if it is defined, and bootm_size is
5435 bootm_size - Memory range available for image processing in the bootm
5436 command can be restricted. This variable is given as
5437 a hexadecimal number and defines the size of the region
5438 allowed for use by the bootm command. See also "bootm_low"
5439 environment variable.
5441 updatefile - Location of the software update file on a TFTP server, used
5442 by the automatic software update feature. Please refer to
5443 documentation in doc/README.update for more details.
5445 autoload - if set to "no" (any string beginning with 'n'),
5446 "bootp" will just load perform a lookup of the
5447 configuration from the BOOTP server, but not try to
5448 load any image using TFTP
5450 autostart - if set to "yes", an image loaded using the "bootp",
5451 "rarpboot", "tftpboot" or "diskboot" commands will
5452 be automatically started (by internally calling
5455 If set to "no", a standalone image passed to the
5456 "bootm" command will be copied to the load address
5457 (and eventually uncompressed), but NOT be started.
5458 This can be used to load and uncompress arbitrary
5461 fdt_high - if set this restricts the maximum address that the
5462 flattened device tree will be copied into upon boot.
5463 For example, if you have a system with 1 GB memory
5464 at physical address 0x10000000, while Linux kernel
5465 only recognizes the first 704 MB as low memory, you
5466 may need to set fdt_high as 0x3C000000 to have the
5467 device tree blob be copied to the maximum address
5468 of the 704 MB low memory, so that Linux kernel can
5469 access it during the boot procedure.
5471 If this is set to the special value 0xFFFFFFFF then
5472 the fdt will not be copied at all on boot. For this
5473 to work it must reside in writable memory, have
5474 sufficient padding on the end of it for u-boot to
5475 add the information it needs into it, and the memory
5476 must be accessible by the kernel.
5478 fdtcontroladdr- if set this is the address of the control flattened
5479 device tree used by U-Boot when CONFIG_OF_CONTROL is
5482 i2cfast - (PPC405GP|PPC405EP only)
5483 if set to 'y' configures Linux I2C driver for fast
5484 mode (400kHZ). This environment variable is used in
5485 initialization code. So, for changes to be effective
5486 it must be saved and board must be reset.
5488 initrd_high - restrict positioning of initrd images:
5489 If this variable is not set, initrd images will be
5490 copied to the highest possible address in RAM; this
5491 is usually what you want since it allows for
5492 maximum initrd size. If for some reason you want to
5493 make sure that the initrd image is loaded below the
5494 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5495 variable to a value of "no" or "off" or "0".
5496 Alternatively, you can set it to a maximum upper
5497 address to use (U-Boot will still check that it
5498 does not overwrite the U-Boot stack and data).
5500 For instance, when you have a system with 16 MB
5501 RAM, and want to reserve 4 MB from use by Linux,
5502 you can do this by adding "mem=12M" to the value of
5503 the "bootargs" variable. However, now you must make
5504 sure that the initrd image is placed in the first
5505 12 MB as well - this can be done with
5507 setenv initrd_high 00c00000
5509 If you set initrd_high to 0xFFFFFFFF, this is an
5510 indication to U-Boot that all addresses are legal
5511 for the Linux kernel, including addresses in flash
5512 memory. In this case U-Boot will NOT COPY the
5513 ramdisk at all. This may be useful to reduce the
5514 boot time on your system, but requires that this
5515 feature is supported by your Linux kernel.
5517 ipaddr - IP address; needed for tftpboot command
5519 loadaddr - Default load address for commands like "bootp",
5520 "rarpboot", "tftpboot", "loadb" or "diskboot"
5522 loads_echo - see CONFIG_LOADS_ECHO
5524 serverip - TFTP server IP address; needed for tftpboot command
5526 bootretry - see CONFIG_BOOT_RETRY_TIME
5528 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5530 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5532 ethprime - controls which interface is used first.
5534 ethact - controls which interface is currently active.
5535 For example you can do the following
5537 => setenv ethact FEC
5538 => ping 192.168.0.1 # traffic sent on FEC
5539 => setenv ethact SCC
5540 => ping 10.0.0.1 # traffic sent on SCC
5542 ethrotate - When set to "no" U-Boot does not go through all
5543 available network interfaces.
5544 It just stays at the currently selected interface.
5546 netretry - When set to "no" each network operation will
5547 either succeed or fail without retrying.
5548 When set to "once" the network operation will
5549 fail when all the available network interfaces
5550 are tried once without success.
5551 Useful on scripts which control the retry operation
5554 npe_ucode - set load address for the NPE microcode
5556 silent_linux - If set then Linux will be told to boot silently, by
5557 changing the console to be empty. If "yes" it will be
5558 made silent. If "no" it will not be made silent. If
5559 unset, then it will be made silent if the U-Boot console
5562 tftpsrcport - If this is set, the value is used for TFTP's
5565 tftpdstport - If this is set, the value is used for TFTP's UDP
5566 destination port instead of the Well Know Port 69.
5568 tftpblocksize - Block size to use for TFTP transfers; if not set,
5569 we use the TFTP server's default block size
5571 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5572 seconds, minimum value is 1000 = 1 second). Defines
5573 when a packet is considered to be lost so it has to
5574 be retransmitted. The default is 5000 = 5 seconds.
5575 Lowering this value may make downloads succeed
5576 faster in networks with high packet loss rates or
5577 with unreliable TFTP servers.
5579 vlan - When set to a value < 4095 the traffic over
5580 Ethernet is encapsulated/received over 802.1q
5583 The following image location variables contain the location of images
5584 used in booting. The "Image" column gives the role of the image and is
5585 not an environment variable name. The other columns are environment
5586 variable names. "File Name" gives the name of the file on a TFTP
5587 server, "RAM Address" gives the location in RAM the image will be
5588 loaded to, and "Flash Location" gives the image's address in NOR
5589 flash or offset in NAND flash.
5591 *Note* - these variables don't have to be defined for all boards, some
5592 boards currently use other variables for these purposes, and some
5593 boards use these variables for other purposes.
5595 Image File Name RAM Address Flash Location
5596 ----- --------- ----------- --------------
5597 u-boot u-boot u-boot_addr_r u-boot_addr
5598 Linux kernel bootfile kernel_addr_r kernel_addr
5599 device tree blob fdtfile fdt_addr_r fdt_addr
5600 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5602 The following environment variables may be used and automatically
5603 updated by the network boot commands ("bootp" and "rarpboot"),
5604 depending the information provided by your boot server:
5606 bootfile - see above
5607 dnsip - IP address of your Domain Name Server
5608 dnsip2 - IP address of your secondary Domain Name Server
5609 gatewayip - IP address of the Gateway (Router) to use
5610 hostname - Target hostname
5612 netmask - Subnet Mask
5613 rootpath - Pathname of the root filesystem on the NFS server
5614 serverip - see above
5617 There are two special Environment Variables:
5619 serial# - contains hardware identification information such
5620 as type string and/or serial number
5621 ethaddr - Ethernet address
5623 These variables can be set only once (usually during manufacturing of
5624 the board). U-Boot refuses to delete or overwrite these variables
5625 once they have been set once.
5628 Further special Environment Variables:
5630 ver - Contains the U-Boot version string as printed
5631 with the "version" command. This variable is
5632 readonly (see CONFIG_VERSION_VARIABLE).
5635 Please note that changes to some configuration parameters may take
5636 only effect after the next boot (yes, that's just like Windoze :-).
5639 Callback functions for environment variables:
5640 ---------------------------------------------
5642 For some environment variables, the behavior of u-boot needs to change
5643 when their values are changed. This functionality allows functions to
5644 be associated with arbitrary variables. On creation, overwrite, or
5645 deletion, the callback will provide the opportunity for some side
5646 effect to happen or for the change to be rejected.
5648 The callbacks are named and associated with a function using the
5649 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5651 These callbacks are associated with variables in one of two ways. The
5652 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5653 in the board configuration to a string that defines a list of
5654 associations. The list must be in the following format:
5656 entry = variable_name[:callback_name]
5659 If the callback name is not specified, then the callback is deleted.
5660 Spaces are also allowed anywhere in the list.
5662 Callbacks can also be associated by defining the ".callbacks" variable
5663 with the same list format above. Any association in ".callbacks" will
5664 override any association in the static list. You can define
5665 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5666 ".callbacks" environment variable in the default or embedded environment.
5668 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5669 regular expression. This allows multiple variables to be connected to
5670 the same callback without explicitly listing them all out.
5673 Command Line Parsing:
5674 =====================
5676 There are two different command line parsers available with U-Boot:
5677 the old "simple" one, and the much more powerful "hush" shell:
5679 Old, simple command line parser:
5680 --------------------------------
5682 - supports environment variables (through setenv / saveenv commands)
5683 - several commands on one line, separated by ';'
5684 - variable substitution using "... ${name} ..." syntax
5685 - special characters ('$', ';') can be escaped by prefixing with '\',
5687 setenv bootcmd bootm \${address}
5688 - You can also escape text by enclosing in single apostrophes, for example:
5689 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5694 - similar to Bourne shell, with control structures like
5695 if...then...else...fi, for...do...done; while...do...done,
5696 until...do...done, ...
5697 - supports environment ("global") variables (through setenv / saveenv
5698 commands) and local shell variables (through standard shell syntax
5699 "name=value"); only environment variables can be used with "run"
5705 (1) If a command line (or an environment variable executed by a "run"
5706 command) contains several commands separated by semicolon, and
5707 one of these commands fails, then the remaining commands will be
5710 (2) If you execute several variables with one call to run (i. e.
5711 calling run with a list of variables as arguments), any failing
5712 command will cause "run" to terminate, i. e. the remaining
5713 variables are not executed.
5715 Note for Redundant Ethernet Interfaces:
5716 =======================================
5718 Some boards come with redundant Ethernet interfaces; U-Boot supports
5719 such configurations and is capable of automatic selection of a
5720 "working" interface when needed. MAC assignment works as follows:
5722 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5723 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5724 "eth1addr" (=>eth1), "eth2addr", ...
5726 If the network interface stores some valid MAC address (for instance
5727 in SROM), this is used as default address if there is NO correspon-
5728 ding setting in the environment; if the corresponding environment
5729 variable is set, this overrides the settings in the card; that means:
5731 o If the SROM has a valid MAC address, and there is no address in the
5732 environment, the SROM's address is used.
5734 o If there is no valid address in the SROM, and a definition in the
5735 environment exists, then the value from the environment variable is
5738 o If both the SROM and the environment contain a MAC address, and
5739 both addresses are the same, this MAC address is used.
5741 o If both the SROM and the environment contain a MAC address, and the
5742 addresses differ, the value from the environment is used and a
5745 o If neither SROM nor the environment contain a MAC address, an error
5746 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5747 a random, locally-assigned MAC is used.
5749 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5750 will be programmed into hardware as part of the initialization process. This
5751 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5752 The naming convention is as follows:
5753 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5758 U-Boot is capable of booting (and performing other auxiliary operations on)
5759 images in two formats:
5761 New uImage format (FIT)
5762 -----------------------
5764 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5765 to Flattened Device Tree). It allows the use of images with multiple
5766 components (several kernels, ramdisks, etc.), with contents protected by
5767 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5773 Old image format is based on binary files which can be basically anything,
5774 preceded by a special header; see the definitions in include/image.h for
5775 details; basically, the header defines the following image properties:
5777 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5778 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5779 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5780 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5782 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5783 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5784 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5785 * Compression Type (uncompressed, gzip, bzip2)
5791 The header is marked by a special Magic Number, and both the header
5792 and the data portions of the image are secured against corruption by
5799 Although U-Boot should support any OS or standalone application
5800 easily, the main focus has always been on Linux during the design of
5803 U-Boot includes many features that so far have been part of some
5804 special "boot loader" code within the Linux kernel. Also, any
5805 "initrd" images to be used are no longer part of one big Linux image;
5806 instead, kernel and "initrd" are separate images. This implementation
5807 serves several purposes:
5809 - the same features can be used for other OS or standalone
5810 applications (for instance: using compressed images to reduce the
5811 Flash memory footprint)
5813 - it becomes much easier to port new Linux kernel versions because
5814 lots of low-level, hardware dependent stuff are done by U-Boot
5816 - the same Linux kernel image can now be used with different "initrd"
5817 images; of course this also means that different kernel images can
5818 be run with the same "initrd". This makes testing easier (you don't
5819 have to build a new "zImage.initrd" Linux image when you just
5820 change a file in your "initrd"). Also, a field-upgrade of the
5821 software is easier now.
5827 Porting Linux to U-Boot based systems:
5828 ---------------------------------------
5830 U-Boot cannot save you from doing all the necessary modifications to
5831 configure the Linux device drivers for use with your target hardware
5832 (no, we don't intend to provide a full virtual machine interface to
5835 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5837 Just make sure your machine specific header file (for instance
5838 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5839 Information structure as we define in include/asm-<arch>/u-boot.h,
5840 and make sure that your definition of IMAP_ADDR uses the same value
5841 as your U-Boot configuration in CONFIG_SYS_IMMR.
5843 Note that U-Boot now has a driver model, a unified model for drivers.
5844 If you are adding a new driver, plumb it into driver model. If there
5845 is no uclass available, you are encouraged to create one. See
5849 Configuring the Linux kernel:
5850 -----------------------------
5852 No specific requirements for U-Boot. Make sure you have some root
5853 device (initial ramdisk, NFS) for your target system.
5856 Building a Linux Image:
5857 -----------------------
5859 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5860 not used. If you use recent kernel source, a new build target
5861 "uImage" will exist which automatically builds an image usable by
5862 U-Boot. Most older kernels also have support for a "pImage" target,
5863 which was introduced for our predecessor project PPCBoot and uses a
5864 100% compatible format.
5868 make TQM850L_defconfig
5873 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5874 encapsulate a compressed Linux kernel image with header information,
5875 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5877 * build a standard "vmlinux" kernel image (in ELF binary format):
5879 * convert the kernel into a raw binary image:
5881 ${CROSS_COMPILE}-objcopy -O binary \
5882 -R .note -R .comment \
5883 -S vmlinux linux.bin
5885 * compress the binary image:
5889 * package compressed binary image for U-Boot:
5891 mkimage -A ppc -O linux -T kernel -C gzip \
5892 -a 0 -e 0 -n "Linux Kernel Image" \
5893 -d linux.bin.gz uImage
5896 The "mkimage" tool can also be used to create ramdisk images for use
5897 with U-Boot, either separated from the Linux kernel image, or
5898 combined into one file. "mkimage" encapsulates the images with a 64
5899 byte header containing information about target architecture,
5900 operating system, image type, compression method, entry points, time
5901 stamp, CRC32 checksums, etc.
5903 "mkimage" can be called in two ways: to verify existing images and
5904 print the header information, or to build new images.
5906 In the first form (with "-l" option) mkimage lists the information
5907 contained in the header of an existing U-Boot image; this includes
5908 checksum verification:
5910 tools/mkimage -l image
5911 -l ==> list image header information
5913 The second form (with "-d" option) is used to build a U-Boot image
5914 from a "data file" which is used as image payload:
5916 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5917 -n name -d data_file image
5918 -A ==> set architecture to 'arch'
5919 -O ==> set operating system to 'os'
5920 -T ==> set image type to 'type'
5921 -C ==> set compression type 'comp'
5922 -a ==> set load address to 'addr' (hex)
5923 -e ==> set entry point to 'ep' (hex)
5924 -n ==> set image name to 'name'
5925 -d ==> use image data from 'datafile'
5927 Right now, all Linux kernels for PowerPC systems use the same load
5928 address (0x00000000), but the entry point address depends on the
5931 - 2.2.x kernels have the entry point at 0x0000000C,
5932 - 2.3.x and later kernels have the entry point at 0x00000000.
5934 So a typical call to build a U-Boot image would read:
5936 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5937 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5938 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5939 > examples/uImage.TQM850L
5940 Image Name: 2.4.4 kernel for TQM850L
5941 Created: Wed Jul 19 02:34:59 2000
5942 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5943 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5944 Load Address: 0x00000000
5945 Entry Point: 0x00000000
5947 To verify the contents of the image (or check for corruption):
5949 -> tools/mkimage -l examples/uImage.TQM850L
5950 Image Name: 2.4.4 kernel for TQM850L
5951 Created: Wed Jul 19 02:34:59 2000
5952 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5953 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5954 Load Address: 0x00000000
5955 Entry Point: 0x00000000
5957 NOTE: for embedded systems where boot time is critical you can trade
5958 speed for memory and install an UNCOMPRESSED image instead: this
5959 needs more space in Flash, but boots much faster since it does not
5960 need to be uncompressed:
5962 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5963 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5964 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5965 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5966 > examples/uImage.TQM850L-uncompressed
5967 Image Name: 2.4.4 kernel for TQM850L
5968 Created: Wed Jul 19 02:34:59 2000
5969 Image Type: PowerPC Linux Kernel Image (uncompressed)
5970 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5971 Load Address: 0x00000000
5972 Entry Point: 0x00000000
5975 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5976 when your kernel is intended to use an initial ramdisk:
5978 -> tools/mkimage -n 'Simple Ramdisk Image' \
5979 > -A ppc -O linux -T ramdisk -C gzip \
5980 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5981 Image Name: Simple Ramdisk Image
5982 Created: Wed Jan 12 14:01:50 2000
5983 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5984 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5985 Load Address: 0x00000000
5986 Entry Point: 0x00000000
5988 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5989 option performs the converse operation of the mkimage's second form (the "-d"
5990 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5993 tools/dumpimage -i image -T type -p position data_file
5994 -i ==> extract from the 'image' a specific 'data_file'
5995 -T ==> set image type to 'type'
5996 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5999 Installing a Linux Image:
6000 -------------------------
6002 To downloading a U-Boot image over the serial (console) interface,
6003 you must convert the image to S-Record format:
6005 objcopy -I binary -O srec examples/image examples/image.srec
6007 The 'objcopy' does not understand the information in the U-Boot
6008 image header, so the resulting S-Record file will be relative to
6009 address 0x00000000. To load it to a given address, you need to
6010 specify the target address as 'offset' parameter with the 'loads'
6013 Example: install the image to address 0x40100000 (which on the
6014 TQM8xxL is in the first Flash bank):
6016 => erase 40100000 401FFFFF
6022 ## Ready for S-Record download ...
6023 ~>examples/image.srec
6024 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6026 15989 15990 15991 15992
6027 [file transfer complete]
6029 ## Start Addr = 0x00000000
6032 You can check the success of the download using the 'iminfo' command;
6033 this includes a checksum verification so you can be sure no data
6034 corruption happened:
6038 ## Checking Image at 40100000 ...
6039 Image Name: 2.2.13 for initrd on TQM850L
6040 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6041 Data Size: 335725 Bytes = 327 kB = 0 MB
6042 Load Address: 00000000
6043 Entry Point: 0000000c
6044 Verifying Checksum ... OK
6050 The "bootm" command is used to boot an application that is stored in
6051 memory (RAM or Flash). In case of a Linux kernel image, the contents
6052 of the "bootargs" environment variable is passed to the kernel as
6053 parameters. You can check and modify this variable using the
6054 "printenv" and "setenv" commands:
6057 => printenv bootargs
6058 bootargs=root=/dev/ram
6060 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6062 => printenv bootargs
6063 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6066 ## Booting Linux kernel at 40020000 ...
6067 Image Name: 2.2.13 for NFS on TQM850L
6068 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6069 Data Size: 381681 Bytes = 372 kB = 0 MB
6070 Load Address: 00000000
6071 Entry Point: 0000000c
6072 Verifying Checksum ... OK
6073 Uncompressing Kernel Image ... OK
6074 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
6075 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6076 time_init: decrementer frequency = 187500000/60
6077 Calibrating delay loop... 49.77 BogoMIPS
6078 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6081 If you want to boot a Linux kernel with initial RAM disk, you pass
6082 the memory addresses of both the kernel and the initrd image (PPBCOOT
6083 format!) to the "bootm" command:
6085 => imi 40100000 40200000
6087 ## Checking Image at 40100000 ...
6088 Image Name: 2.2.13 for initrd on TQM850L
6089 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6090 Data Size: 335725 Bytes = 327 kB = 0 MB
6091 Load Address: 00000000
6092 Entry Point: 0000000c
6093 Verifying Checksum ... OK
6095 ## Checking Image at 40200000 ...
6096 Image Name: Simple Ramdisk Image
6097 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6098 Data Size: 566530 Bytes = 553 kB = 0 MB
6099 Load Address: 00000000
6100 Entry Point: 00000000
6101 Verifying Checksum ... OK
6103 => bootm 40100000 40200000
6104 ## Booting Linux kernel at 40100000 ...
6105 Image Name: 2.2.13 for initrd on TQM850L
6106 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6107 Data Size: 335725 Bytes = 327 kB = 0 MB
6108 Load Address: 00000000
6109 Entry Point: 0000000c
6110 Verifying Checksum ... OK
6111 Uncompressing Kernel Image ... OK
6112 ## Loading RAMDisk Image at 40200000 ...
6113 Image Name: Simple Ramdisk Image
6114 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6115 Data Size: 566530 Bytes = 553 kB = 0 MB
6116 Load Address: 00000000
6117 Entry Point: 00000000
6118 Verifying Checksum ... OK
6119 Loading Ramdisk ... OK
6120 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
6121 Boot arguments: root=/dev/ram
6122 time_init: decrementer frequency = 187500000/60
6123 Calibrating delay loop... 49.77 BogoMIPS
6125 RAMDISK: Compressed image found at block 0
6126 VFS: Mounted root (ext2 filesystem).
6130 Boot Linux and pass a flat device tree:
6133 First, U-Boot must be compiled with the appropriate defines. See the section
6134 titled "Linux Kernel Interface" above for a more in depth explanation. The
6135 following is an example of how to start a kernel and pass an updated
6141 oft=oftrees/mpc8540ads.dtb
6142 => tftp $oftaddr $oft
6143 Speed: 1000, full duplex
6145 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6146 Filename 'oftrees/mpc8540ads.dtb'.
6147 Load address: 0x300000
6150 Bytes transferred = 4106 (100a hex)
6151 => tftp $loadaddr $bootfile
6152 Speed: 1000, full duplex
6154 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6156 Load address: 0x200000
6157 Loading:############
6159 Bytes transferred = 1029407 (fb51f hex)
6164 => bootm $loadaddr - $oftaddr
6165 ## Booting image at 00200000 ...
6166 Image Name: Linux-2.6.17-dirty
6167 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6168 Data Size: 1029343 Bytes = 1005.2 kB
6169 Load Address: 00000000
6170 Entry Point: 00000000
6171 Verifying Checksum ... OK
6172 Uncompressing Kernel Image ... OK
6173 Booting using flat device tree at 0x300000
6174 Using MPC85xx ADS machine description
6175 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6179 More About U-Boot Image Types:
6180 ------------------------------
6182 U-Boot supports the following image types:
6184 "Standalone Programs" are directly runnable in the environment
6185 provided by U-Boot; it is expected that (if they behave
6186 well) you can continue to work in U-Boot after return from
6187 the Standalone Program.
6188 "OS Kernel Images" are usually images of some Embedded OS which
6189 will take over control completely. Usually these programs
6190 will install their own set of exception handlers, device
6191 drivers, set up the MMU, etc. - this means, that you cannot
6192 expect to re-enter U-Boot except by resetting the CPU.
6193 "RAMDisk Images" are more or less just data blocks, and their
6194 parameters (address, size) are passed to an OS kernel that is
6196 "Multi-File Images" contain several images, typically an OS
6197 (Linux) kernel image and one or more data images like
6198 RAMDisks. This construct is useful for instance when you want
6199 to boot over the network using BOOTP etc., where the boot
6200 server provides just a single image file, but you want to get
6201 for instance an OS kernel and a RAMDisk image.
6203 "Multi-File Images" start with a list of image sizes, each
6204 image size (in bytes) specified by an "uint32_t" in network
6205 byte order. This list is terminated by an "(uint32_t)0".
6206 Immediately after the terminating 0 follow the images, one by
6207 one, all aligned on "uint32_t" boundaries (size rounded up to
6208 a multiple of 4 bytes).
6210 "Firmware Images" are binary images containing firmware (like
6211 U-Boot or FPGA images) which usually will be programmed to
6214 "Script files" are command sequences that will be executed by
6215 U-Boot's command interpreter; this feature is especially
6216 useful when you configure U-Boot to use a real shell (hush)
6217 as command interpreter.
6219 Booting the Linux zImage:
6220 -------------------------
6222 On some platforms, it's possible to boot Linux zImage. This is done
6223 using the "bootz" command. The syntax of "bootz" command is the same
6224 as the syntax of "bootm" command.
6226 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6227 kernel with raw initrd images. The syntax is slightly different, the
6228 address of the initrd must be augmented by it's size, in the following
6229 format: "<initrd addres>:<initrd size>".
6235 One of the features of U-Boot is that you can dynamically load and
6236 run "standalone" applications, which can use some resources of
6237 U-Boot like console I/O functions or interrupt services.
6239 Two simple examples are included with the sources:
6244 'examples/hello_world.c' contains a small "Hello World" Demo
6245 application; it is automatically compiled when you build U-Boot.
6246 It's configured to run at address 0x00040004, so you can play with it
6250 ## Ready for S-Record download ...
6251 ~>examples/hello_world.srec
6252 1 2 3 4 5 6 7 8 9 10 11 ...
6253 [file transfer complete]
6255 ## Start Addr = 0x00040004
6257 => go 40004 Hello World! This is a test.
6258 ## Starting application at 0x00040004 ...
6269 Hit any key to exit ...
6271 ## Application terminated, rc = 0x0
6273 Another example, which demonstrates how to register a CPM interrupt
6274 handler with the U-Boot code, can be found in 'examples/timer.c'.
6275 Here, a CPM timer is set up to generate an interrupt every second.
6276 The interrupt service routine is trivial, just printing a '.'
6277 character, but this is just a demo program. The application can be
6278 controlled by the following keys:
6280 ? - print current values og the CPM Timer registers
6281 b - enable interrupts and start timer
6282 e - stop timer and disable interrupts
6283 q - quit application
6286 ## Ready for S-Record download ...
6287 ~>examples/timer.srec
6288 1 2 3 4 5 6 7 8 9 10 11 ...
6289 [file transfer complete]
6291 ## Start Addr = 0x00040004
6294 ## Starting application at 0x00040004 ...
6297 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6300 [q, b, e, ?] Set interval 1000000 us
6303 [q, b, e, ?] ........
6304 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6307 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6310 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6313 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6315 [q, b, e, ?] ...Stopping timer
6317 [q, b, e, ?] ## Application terminated, rc = 0x0
6323 Over time, many people have reported problems when trying to use the
6324 "minicom" terminal emulation program for serial download. I (wd)
6325 consider minicom to be broken, and recommend not to use it. Under
6326 Unix, I recommend to use C-Kermit for general purpose use (and
6327 especially for kermit binary protocol download ("loadb" command), and
6328 use "cu" for S-Record download ("loads" command). See
6329 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6330 for help with kermit.
6333 Nevertheless, if you absolutely want to use it try adding this
6334 configuration to your "File transfer protocols" section:
6336 Name Program Name U/D FullScr IO-Red. Multi
6337 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6338 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6344 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6345 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6347 Building requires a cross environment; it is known to work on
6348 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6349 need gmake since the Makefiles are not compatible with BSD make).
6350 Note that the cross-powerpc package does not install include files;
6351 attempting to build U-Boot will fail because <machine/ansi.h> is
6352 missing. This file has to be installed and patched manually:
6354 # cd /usr/pkg/cross/powerpc-netbsd/include
6356 # ln -s powerpc machine
6357 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6358 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6360 Native builds *don't* work due to incompatibilities between native
6361 and U-Boot include files.
6363 Booting assumes that (the first part of) the image booted is a
6364 stage-2 loader which in turn loads and then invokes the kernel
6365 proper. Loader sources will eventually appear in the NetBSD source
6366 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6367 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6370 Implementation Internals:
6371 =========================
6373 The following is not intended to be a complete description of every
6374 implementation detail. However, it should help to understand the
6375 inner workings of U-Boot and make it easier to port it to custom
6379 Initial Stack, Global Data:
6380 ---------------------------
6382 The implementation of U-Boot is complicated by the fact that U-Boot
6383 starts running out of ROM (flash memory), usually without access to
6384 system RAM (because the memory controller is not initialized yet).
6385 This means that we don't have writable Data or BSS segments, and BSS
6386 is not initialized as zero. To be able to get a C environment working
6387 at all, we have to allocate at least a minimal stack. Implementation
6388 options for this are defined and restricted by the CPU used: Some CPU
6389 models provide on-chip memory (like the IMMR area on MPC8xx and
6390 MPC826x processors), on others (parts of) the data cache can be
6391 locked as (mis-) used as memory, etc.
6393 Chris Hallinan posted a good summary of these issues to the
6394 U-Boot mailing list:
6396 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6397 From: "Chris Hallinan" <clh@net1plus.com>
6398 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6401 Correct me if I'm wrong, folks, but the way I understand it
6402 is this: Using DCACHE as initial RAM for Stack, etc, does not
6403 require any physical RAM backing up the cache. The cleverness
6404 is that the cache is being used as a temporary supply of
6405 necessary storage before the SDRAM controller is setup. It's
6406 beyond the scope of this list to explain the details, but you
6407 can see how this works by studying the cache architecture and
6408 operation in the architecture and processor-specific manuals.
6410 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6411 is another option for the system designer to use as an
6412 initial stack/RAM area prior to SDRAM being available. Either
6413 option should work for you. Using CS 4 should be fine if your
6414 board designers haven't used it for something that would
6415 cause you grief during the initial boot! It is frequently not
6418 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6419 with your processor/board/system design. The default value
6420 you will find in any recent u-boot distribution in
6421 walnut.h should work for you. I'd set it to a value larger
6422 than your SDRAM module. If you have a 64MB SDRAM module, set
6423 it above 400_0000. Just make sure your board has no resources
6424 that are supposed to respond to that address! That code in
6425 start.S has been around a while and should work as is when
6426 you get the config right.
6431 It is essential to remember this, since it has some impact on the C
6432 code for the initialization procedures:
6434 * Initialized global data (data segment) is read-only. Do not attempt
6437 * Do not use any uninitialized global data (or implicitly initialized
6438 as zero data - BSS segment) at all - this is undefined, initiali-
6439 zation is performed later (when relocating to RAM).
6441 * Stack space is very limited. Avoid big data buffers or things like
6444 Having only the stack as writable memory limits means we cannot use
6445 normal global data to share information between the code. But it
6446 turned out that the implementation of U-Boot can be greatly
6447 simplified by making a global data structure (gd_t) available to all
6448 functions. We could pass a pointer to this data as argument to _all_
6449 functions, but this would bloat the code. Instead we use a feature of
6450 the GCC compiler (Global Register Variables) to share the data: we
6451 place a pointer (gd) to the global data into a register which we
6452 reserve for this purpose.
6454 When choosing a register for such a purpose we are restricted by the
6455 relevant (E)ABI specifications for the current architecture, and by
6456 GCC's implementation.
6458 For PowerPC, the following registers have specific use:
6460 R2: reserved for system use
6461 R3-R4: parameter passing and return values
6462 R5-R10: parameter passing
6463 R13: small data area pointer
6467 (U-Boot also uses R12 as internal GOT pointer. r12
6468 is a volatile register so r12 needs to be reset when
6469 going back and forth between asm and C)
6471 ==> U-Boot will use R2 to hold a pointer to the global data
6473 Note: on PPC, we could use a static initializer (since the
6474 address of the global data structure is known at compile time),
6475 but it turned out that reserving a register results in somewhat
6476 smaller code - although the code savings are not that big (on
6477 average for all boards 752 bytes for the whole U-Boot image,
6478 624 text + 127 data).
6480 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6481 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6483 ==> U-Boot will use P3 to hold a pointer to the global data
6485 On ARM, the following registers are used:
6487 R0: function argument word/integer result
6488 R1-R3: function argument word
6489 R9: platform specific
6490 R10: stack limit (used only if stack checking is enabled)
6491 R11: argument (frame) pointer
6492 R12: temporary workspace
6495 R15: program counter
6497 ==> U-Boot will use R9 to hold a pointer to the global data
6499 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6501 On Nios II, the ABI is documented here:
6502 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6504 ==> U-Boot will use gp to hold a pointer to the global data
6506 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6507 to access small data sections, so gp is free.
6509 On NDS32, the following registers are used:
6511 R0-R1: argument/return
6513 R15: temporary register for assembler
6514 R16: trampoline register
6515 R28: frame pointer (FP)
6516 R29: global pointer (GP)
6517 R30: link register (LP)
6518 R31: stack pointer (SP)
6519 PC: program counter (PC)
6521 ==> U-Boot will use R10 to hold a pointer to the global data
6523 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6524 or current versions of GCC may "optimize" the code too much.
6529 U-Boot runs in system state and uses physical addresses, i.e. the
6530 MMU is not used either for address mapping nor for memory protection.
6532 The available memory is mapped to fixed addresses using the memory
6533 controller. In this process, a contiguous block is formed for each
6534 memory type (Flash, SDRAM, SRAM), even when it consists of several
6535 physical memory banks.
6537 U-Boot is installed in the first 128 kB of the first Flash bank (on
6538 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6539 booting and sizing and initializing DRAM, the code relocates itself
6540 to the upper end of DRAM. Immediately below the U-Boot code some
6541 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6542 configuration setting]. Below that, a structure with global Board
6543 Info data is placed, followed by the stack (growing downward).
6545 Additionally, some exception handler code is copied to the low 8 kB
6546 of DRAM (0x00000000 ... 0x00001FFF).
6548 So a typical memory configuration with 16 MB of DRAM could look like
6551 0x0000 0000 Exception Vector code
6554 0x0000 2000 Free for Application Use
6560 0x00FB FF20 Monitor Stack (Growing downward)
6561 0x00FB FFAC Board Info Data and permanent copy of global data
6562 0x00FC 0000 Malloc Arena
6565 0x00FE 0000 RAM Copy of Monitor Code
6566 ... eventually: LCD or video framebuffer
6567 ... eventually: pRAM (Protected RAM - unchanged by reset)
6568 0x00FF FFFF [End of RAM]
6571 System Initialization:
6572 ----------------------
6574 In the reset configuration, U-Boot starts at the reset entry point
6575 (on most PowerPC systems at address 0x00000100). Because of the reset
6576 configuration for CS0# this is a mirror of the on board Flash memory.
6577 To be able to re-map memory U-Boot then jumps to its link address.
6578 To be able to implement the initialization code in C, a (small!)
6579 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6580 which provide such a feature like MPC8xx or MPC8260), or in a locked
6581 part of the data cache. After that, U-Boot initializes the CPU core,
6582 the caches and the SIU.
6584 Next, all (potentially) available memory banks are mapped using a
6585 preliminary mapping. For example, we put them on 512 MB boundaries
6586 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6587 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6588 programmed for SDRAM access. Using the temporary configuration, a
6589 simple memory test is run that determines the size of the SDRAM
6592 When there is more than one SDRAM bank, and the banks are of
6593 different size, the largest is mapped first. For equal size, the first
6594 bank (CS2#) is mapped first. The first mapping is always for address
6595 0x00000000, with any additional banks following immediately to create
6596 contiguous memory starting from 0.
6598 Then, the monitor installs itself at the upper end of the SDRAM area
6599 and allocates memory for use by malloc() and for the global Board
6600 Info data; also, the exception vector code is copied to the low RAM
6601 pages, and the final stack is set up.
6603 Only after this relocation will you have a "normal" C environment;
6604 until that you are restricted in several ways, mostly because you are
6605 running from ROM, and because the code will have to be relocated to a
6609 U-Boot Porting Guide:
6610 ----------------------
6612 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6616 int main(int argc, char *argv[])
6618 sighandler_t no_more_time;
6620 signal(SIGALRM, no_more_time);
6621 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6623 if (available_money > available_manpower) {
6624 Pay consultant to port U-Boot;
6628 Download latest U-Boot source;
6630 Subscribe to u-boot mailing list;
6633 email("Hi, I am new to U-Boot, how do I get started?");
6636 Read the README file in the top level directory;
6637 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6638 Read applicable doc/*.README;
6639 Read the source, Luke;
6640 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6643 if (available_money > toLocalCurrency ($2500))
6646 Add a lot of aggravation and time;
6648 if (a similar board exists) { /* hopefully... */
6649 cp -a board/<similar> board/<myboard>
6650 cp include/configs/<similar>.h include/configs/<myboard>.h
6652 Create your own board support subdirectory;
6653 Create your own board include/configs/<myboard>.h file;
6655 Edit new board/<myboard> files
6656 Edit new include/configs/<myboard>.h
6661 Add / modify source code;
6665 email("Hi, I am having problems...");
6667 Send patch file to the U-Boot email list;
6668 if (reasonable critiques)
6669 Incorporate improvements from email list code review;
6671 Defend code as written;
6677 void no_more_time (int sig)
6686 All contributions to U-Boot should conform to the Linux kernel
6687 coding style; see the file "Documentation/CodingStyle" and the script
6688 "scripts/Lindent" in your Linux kernel source directory.
6690 Source files originating from a different project (for example the
6691 MTD subsystem) are generally exempt from these guidelines and are not
6692 reformatted to ease subsequent migration to newer versions of those
6695 Please note that U-Boot is implemented in C (and to some small parts in
6696 Assembler); no C++ is used, so please do not use C++ style comments (//)
6699 Please also stick to the following formatting rules:
6700 - remove any trailing white space
6701 - use TAB characters for indentation and vertical alignment, not spaces
6702 - make sure NOT to use DOS '\r\n' line feeds
6703 - do not add more than 2 consecutive empty lines to source files
6704 - do not add trailing empty lines to source files
6706 Submissions which do not conform to the standards may be returned
6707 with a request to reformat the changes.
6713 Since the number of patches for U-Boot is growing, we need to
6714 establish some rules. Submissions which do not conform to these rules
6715 may be rejected, even when they contain important and valuable stuff.
6717 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6719 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6720 see http://lists.denx.de/mailman/listinfo/u-boot
6722 When you send a patch, please include the following information with
6725 * For bug fixes: a description of the bug and how your patch fixes
6726 this bug. Please try to include a way of demonstrating that the
6727 patch actually fixes something.
6729 * For new features: a description of the feature and your
6732 * A CHANGELOG entry as plaintext (separate from the patch)
6734 * For major contributions, your entry to the CREDITS file
6736 * When you add support for a new board, don't forget to add a
6737 maintainer e-mail address to the boards.cfg file, too.
6739 * If your patch adds new configuration options, don't forget to
6740 document these in the README file.
6742 * The patch itself. If you are using git (which is *strongly*
6743 recommended) you can easily generate the patch using the
6744 "git format-patch". If you then use "git send-email" to send it to
6745 the U-Boot mailing list, you will avoid most of the common problems
6746 with some other mail clients.
6748 If you cannot use git, use "diff -purN OLD NEW". If your version of
6749 diff does not support these options, then get the latest version of
6752 The current directory when running this command shall be the parent
6753 directory of the U-Boot source tree (i. e. please make sure that
6754 your patch includes sufficient directory information for the
6757 We prefer patches as plain text. MIME attachments are discouraged,
6758 and compressed attachments must not be used.
6760 * If one logical set of modifications affects or creates several
6761 files, all these changes shall be submitted in a SINGLE patch file.
6763 * Changesets that contain different, unrelated modifications shall be
6764 submitted as SEPARATE patches, one patch per changeset.
6769 * Before sending the patch, run the MAKEALL script on your patched
6770 source tree and make sure that no errors or warnings are reported
6771 for any of the boards.
6773 * Keep your modifications to the necessary minimum: A patch
6774 containing several unrelated changes or arbitrary reformats will be
6775 returned with a request to re-formatting / split it.
6777 * If you modify existing code, make sure that your new code does not
6778 add to the memory footprint of the code ;-) Small is beautiful!
6779 When adding new features, these should compile conditionally only
6780 (using #ifdef), and the resulting code with the new feature
6781 disabled must not need more memory than the old code without your
6784 * Remember that there is a size limit of 100 kB per message on the
6785 u-boot mailing list. Bigger patches will be moderated. If they are
6786 reasonable and not too big, they will be acknowledged. But patches
6787 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob