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_ZERO_BOOTDELAY_CHECK
1091 CONFIG_RESET_TO_RETRY
1095 Only needed when CONFIG_BOOTDELAY is enabled;
1096 define a command string that is automatically executed
1097 when no character is read on the console interface
1098 within "Boot Delay" after reset.
1101 This can be used to pass arguments to the bootm
1102 command. The value of CONFIG_BOOTARGS goes into the
1103 environment value "bootargs".
1105 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1106 The value of these goes into the environment as
1107 "ramboot" and "nfsboot" respectively, and can be used
1108 as a convenience, when switching between booting from
1112 CONFIG_BOOTCOUNT_LIMIT
1113 Implements a mechanism for detecting a repeating reboot
1115 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1117 CONFIG_BOOTCOUNT_ENV
1118 If no softreset save registers are found on the hardware
1119 "bootcount" is stored in the environment. To prevent a
1120 saveenv on all reboots, the environment variable
1121 "upgrade_available" is used. If "upgrade_available" is
1122 0, "bootcount" is always 0, if "upgrade_available" is
1123 1 "bootcount" is incremented in the environment.
1124 So the Userspace Applikation must set the "upgrade_available"
1125 and "bootcount" variable to 0, if a boot was successfully.
1127 - Pre-Boot Commands:
1130 When this option is #defined, the existence of the
1131 environment variable "preboot" will be checked
1132 immediately before starting the CONFIG_BOOTDELAY
1133 countdown and/or running the auto-boot command resp.
1134 entering interactive mode.
1136 This feature is especially useful when "preboot" is
1137 automatically generated or modified. For an example
1138 see the LWMON board specific code: here "preboot" is
1139 modified when the user holds down a certain
1140 combination of keys on the (special) keyboard when
1143 - Serial Download Echo Mode:
1145 If defined to 1, all characters received during a
1146 serial download (using the "loads" command) are
1147 echoed back. This might be needed by some terminal
1148 emulations (like "cu"), but may as well just take
1149 time on others. This setting #define's the initial
1150 value of the "loads_echo" environment variable.
1152 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1153 CONFIG_KGDB_BAUDRATE
1154 Select one of the baudrates listed in
1155 CONFIG_SYS_BAUDRATE_TABLE, see below.
1157 - Monitor Functions:
1158 Monitor commands can be included or excluded
1159 from the build by using the #include files
1160 <config_cmd_all.h> and #undef'ing unwanted
1161 commands, or using <config_cmd_default.h>
1162 and augmenting with additional #define's
1163 for wanted commands.
1165 The default command configuration includes all commands
1166 except those marked below with a "*".
1168 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1169 CONFIG_CMD_ASKENV * ask for env variable
1170 CONFIG_CMD_BDI bdinfo
1171 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1172 CONFIG_CMD_BMP * BMP support
1173 CONFIG_CMD_BSP * Board specific commands
1174 CONFIG_CMD_BOOTD bootd
1175 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1176 CONFIG_CMD_CACHE * icache, dcache
1177 CONFIG_CMD_CLK * clock command support
1178 CONFIG_CMD_CONSOLE coninfo
1179 CONFIG_CMD_CRC32 * crc32
1180 CONFIG_CMD_DATE * support for RTC, date/time...
1181 CONFIG_CMD_DHCP * DHCP support
1182 CONFIG_CMD_DIAG * Diagnostics
1183 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1184 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1185 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1186 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1187 CONFIG_CMD_DTT * Digital Therm and Thermostat
1188 CONFIG_CMD_ECHO echo arguments
1189 CONFIG_CMD_EDITENV edit env variable
1190 CONFIG_CMD_EEPROM * EEPROM read/write support
1191 CONFIG_CMD_ELF * bootelf, bootvx
1192 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1193 CONFIG_CMD_ENV_FLAGS * display details about env flags
1194 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1195 CONFIG_CMD_EXPORTENV * export the environment
1196 CONFIG_CMD_EXT2 * ext2 command support
1197 CONFIG_CMD_EXT4 * ext4 command support
1198 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1199 that work for multiple fs types
1200 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1201 CONFIG_CMD_SAVEENV saveenv
1202 CONFIG_CMD_FDC * Floppy Disk Support
1203 CONFIG_CMD_FAT * FAT command support
1204 CONFIG_CMD_FLASH flinfo, erase, protect
1205 CONFIG_CMD_FPGA FPGA device initialization support
1206 CONFIG_CMD_FUSE * Device fuse support
1207 CONFIG_CMD_GETTIME * Get time since boot
1208 CONFIG_CMD_GO * the 'go' command (exec code)
1209 CONFIG_CMD_GREPENV * search environment
1210 CONFIG_CMD_HASH * calculate hash / digest
1211 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1212 CONFIG_CMD_I2C * I2C serial bus support
1213 CONFIG_CMD_IDE * IDE harddisk support
1214 CONFIG_CMD_IMI iminfo
1215 CONFIG_CMD_IMLS List all images found in NOR flash
1216 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1217 CONFIG_CMD_IMMAP * IMMR dump support
1218 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1219 CONFIG_CMD_IMPORTENV * import an environment
1220 CONFIG_CMD_INI * import data from an ini file into the env
1221 CONFIG_CMD_IRQ * irqinfo
1222 CONFIG_CMD_ITEST Integer/string test of 2 values
1223 CONFIG_CMD_JFFS2 * JFFS2 Support
1224 CONFIG_CMD_KGDB * kgdb
1225 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1226 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1228 CONFIG_CMD_LOADB loadb
1229 CONFIG_CMD_LOADS loads
1230 CONFIG_CMD_MD5SUM * print md5 message digest
1231 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1232 CONFIG_CMD_MEMINFO * Display detailed memory information
1233 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1235 CONFIG_CMD_MEMTEST * mtest
1236 CONFIG_CMD_MISC Misc functions like sleep etc
1237 CONFIG_CMD_MMC * MMC memory mapped support
1238 CONFIG_CMD_MII * MII utility commands
1239 CONFIG_CMD_MTDPARTS * MTD partition support
1240 CONFIG_CMD_NAND * NAND support
1241 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1242 CONFIG_CMD_NFS NFS support
1243 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1244 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1245 CONFIG_CMD_PCI * pciinfo
1246 CONFIG_CMD_PCMCIA * PCMCIA support
1247 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1249 CONFIG_CMD_PORTIO * Port I/O
1250 CONFIG_CMD_READ * Read raw data from partition
1251 CONFIG_CMD_REGINFO * Register dump
1252 CONFIG_CMD_RUN run command in env variable
1253 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1254 CONFIG_CMD_SAVES * save S record dump
1255 CONFIG_CMD_SCSI * SCSI Support
1256 CONFIG_CMD_SDRAM * print SDRAM configuration information
1257 (requires CONFIG_CMD_I2C)
1258 CONFIG_CMD_SETGETDCR Support for DCR Register access
1260 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1261 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1262 (requires CONFIG_CMD_MEMORY)
1263 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1264 CONFIG_CMD_SOURCE "source" command Support
1265 CONFIG_CMD_SPI * SPI serial bus support
1266 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1267 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1268 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1269 CONFIG_CMD_TIMER * access to the system tick timer
1270 CONFIG_CMD_USB * USB support
1271 CONFIG_CMD_CDP * Cisco Discover Protocol support
1272 CONFIG_CMD_MFSL * Microblaze FSL support
1273 CONFIG_CMD_XIMG Load part of Multi Image
1274 CONFIG_CMD_UUID * Generate random UUID or GUID string
1276 EXAMPLE: If you want all functions except of network
1277 support you can write:
1279 #include "config_cmd_all.h"
1280 #undef CONFIG_CMD_NET
1283 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1285 Note: Don't enable the "icache" and "dcache" commands
1286 (configuration option CONFIG_CMD_CACHE) unless you know
1287 what you (and your U-Boot users) are doing. Data
1288 cache cannot be enabled on systems like the 8xx or
1289 8260 (where accesses to the IMMR region must be
1290 uncached), and it cannot be disabled on all other
1291 systems where we (mis-) use the data cache to hold an
1292 initial stack and some data.
1295 XXX - this list needs to get updated!
1297 - Regular expression support:
1299 If this variable is defined, U-Boot is linked against
1300 the SLRE (Super Light Regular Expression) library,
1301 which adds regex support to some commands, as for
1302 example "env grep" and "setexpr".
1306 If this variable is defined, U-Boot will use a device tree
1307 to configure its devices, instead of relying on statically
1308 compiled #defines in the board file. This option is
1309 experimental and only available on a few boards. The device
1310 tree is available in the global data as gd->fdt_blob.
1312 U-Boot needs to get its device tree from somewhere. This can
1313 be done using one of the two options below:
1316 If this variable is defined, U-Boot will embed a device tree
1317 binary in its image. This device tree file should be in the
1318 board directory and called <soc>-<board>.dts. The binary file
1319 is then picked up in board_init_f() and made available through
1320 the global data structure as gd->blob.
1323 If this variable is defined, U-Boot will build a device tree
1324 binary. It will be called u-boot.dtb. Architecture-specific
1325 code will locate it at run-time. Generally this works by:
1327 cat u-boot.bin u-boot.dtb >image.bin
1329 and in fact, U-Boot does this for you, creating a file called
1330 u-boot-dtb.bin which is useful in the common case. You can
1331 still use the individual files if you need something more
1336 If this variable is defined, it enables watchdog
1337 support for the SoC. There must be support in the SoC
1338 specific code for a watchdog. For the 8xx and 8260
1339 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1340 register. When supported for a specific SoC is
1341 available, then no further board specific code should
1342 be needed to use it.
1345 When using a watchdog circuitry external to the used
1346 SoC, then define this variable and provide board
1347 specific code for the "hw_watchdog_reset" function.
1349 CONFIG_AT91_HW_WDT_TIMEOUT
1350 specify the timeout in seconds. default 2 seconds.
1353 CONFIG_VERSION_VARIABLE
1354 If this variable is defined, an environment variable
1355 named "ver" is created by U-Boot showing the U-Boot
1356 version as printed by the "version" command.
1357 Any change to this variable will be reverted at the
1362 When CONFIG_CMD_DATE is selected, the type of the RTC
1363 has to be selected, too. Define exactly one of the
1366 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1367 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1368 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1369 CONFIG_RTC_MC146818 - use MC146818 RTC
1370 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1371 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1372 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1373 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1374 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1375 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1376 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1377 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1378 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1381 Note that if the RTC uses I2C, then the I2C interface
1382 must also be configured. See I2C Support, below.
1385 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1387 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1388 chip-ngpio pairs that tell the PCA953X driver the number of
1389 pins supported by a particular chip.
1391 Note that if the GPIO device uses I2C, then the I2C interface
1392 must also be configured. See I2C Support, below.
1395 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1396 accesses and can checksum them or write a list of them out
1397 to memory. See the 'iotrace' command for details. This is
1398 useful for testing device drivers since it can confirm that
1399 the driver behaves the same way before and after a code
1400 change. Currently this is supported on sandbox and arm. To
1401 add support for your architecture, add '#include <iotrace.h>'
1402 to the bottom of arch/<arch>/include/asm/io.h and test.
1404 Example output from the 'iotrace stats' command is below.
1405 Note that if the trace buffer is exhausted, the checksum will
1406 still continue to operate.
1409 Start: 10000000 (buffer start address)
1410 Size: 00010000 (buffer size)
1411 Offset: 00000120 (current buffer offset)
1412 Output: 10000120 (start + offset)
1413 Count: 00000018 (number of trace records)
1414 CRC32: 9526fb66 (CRC32 of all trace records)
1416 - Timestamp Support:
1418 When CONFIG_TIMESTAMP is selected, the timestamp
1419 (date and time) of an image is printed by image
1420 commands like bootm or iminfo. This option is
1421 automatically enabled when you select CONFIG_CMD_DATE .
1423 - Partition Labels (disklabels) Supported:
1424 Zero or more of the following:
1425 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1426 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1427 Intel architecture, USB sticks, etc.
1428 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1429 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1430 bootloader. Note 2TB partition limit; see
1432 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1434 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1435 CONFIG_CMD_SCSI) you must configure support for at
1436 least one non-MTD partition type as well.
1439 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1440 board configurations files but used nowhere!
1442 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1443 be performed by calling the function
1444 ide_set_reset(int reset)
1445 which has to be defined in a board specific file
1450 Set this to enable ATAPI support.
1455 Set this to enable support for disks larger than 137GB
1456 Also look at CONFIG_SYS_64BIT_LBA.
1457 Whithout these , LBA48 support uses 32bit variables and will 'only'
1458 support disks up to 2.1TB.
1460 CONFIG_SYS_64BIT_LBA:
1461 When enabled, makes the IDE subsystem use 64bit sector addresses.
1465 At the moment only there is only support for the
1466 SYM53C8XX SCSI controller; define
1467 CONFIG_SCSI_SYM53C8XX to enable it.
1469 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1470 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1471 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1472 maximum numbers of LUNs, SCSI ID's and target
1474 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1476 The environment variable 'scsidevs' is set to the number of
1477 SCSI devices found during the last scan.
1479 - NETWORK Support (PCI):
1481 Support for Intel 8254x/8257x gigabit chips.
1484 Utility code for direct access to the SPI bus on Intel 8257x.
1485 This does not do anything useful unless you set at least one
1486 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1488 CONFIG_E1000_SPI_GENERIC
1489 Allow generic access to the SPI bus on the Intel 8257x, for
1490 example with the "sspi" command.
1493 Management command for E1000 devices. When used on devices
1494 with SPI support you can reprogram the EEPROM from U-Boot.
1496 CONFIG_E1000_FALLBACK_MAC
1497 default MAC for empty EEPROM after production.
1500 Support for Intel 82557/82559/82559ER chips.
1501 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1502 write routine for first time initialisation.
1505 Support for Digital 2114x chips.
1506 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1507 modem chip initialisation (KS8761/QS6611).
1510 Support for National dp83815 chips.
1513 Support for National dp8382[01] gigabit chips.
1515 - NETWORK Support (other):
1517 CONFIG_DRIVER_AT91EMAC
1518 Support for AT91RM9200 EMAC.
1521 Define this to use reduced MII inteface
1523 CONFIG_DRIVER_AT91EMAC_QUIET
1524 If this defined, the driver is quiet.
1525 The driver doen't show link status messages.
1527 CONFIG_CALXEDA_XGMAC
1528 Support for the Calxeda XGMAC device
1531 Support for SMSC's LAN91C96 chips.
1533 CONFIG_LAN91C96_BASE
1534 Define this to hold the physical address
1535 of the LAN91C96's I/O space
1537 CONFIG_LAN91C96_USE_32_BIT
1538 Define this to enable 32 bit addressing
1541 Support for SMSC's LAN91C111 chip
1543 CONFIG_SMC91111_BASE
1544 Define this to hold the physical address
1545 of the device (I/O space)
1547 CONFIG_SMC_USE_32_BIT
1548 Define this if data bus is 32 bits
1550 CONFIG_SMC_USE_IOFUNCS
1551 Define this to use i/o functions instead of macros
1552 (some hardware wont work with macros)
1554 CONFIG_DRIVER_TI_EMAC
1555 Support for davinci emac
1557 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1558 Define this if you have more then 3 PHYs.
1561 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1563 CONFIG_FTGMAC100_EGIGA
1564 Define this to use GE link update with gigabit PHY.
1565 Define this if FTGMAC100 is connected to gigabit PHY.
1566 If your system has 10/100 PHY only, it might not occur
1567 wrong behavior. Because PHY usually return timeout or
1568 useless data when polling gigabit status and gigabit
1569 control registers. This behavior won't affect the
1570 correctnessof 10/100 link speed update.
1573 Support for SMSC's LAN911x and LAN921x chips
1576 Define this to hold the physical address
1577 of the device (I/O space)
1579 CONFIG_SMC911X_32_BIT
1580 Define this if data bus is 32 bits
1582 CONFIG_SMC911X_16_BIT
1583 Define this if data bus is 16 bits. If your processor
1584 automatically converts one 32 bit word to two 16 bit
1585 words you may also try CONFIG_SMC911X_32_BIT.
1588 Support for Renesas on-chip Ethernet controller
1590 CONFIG_SH_ETHER_USE_PORT
1591 Define the number of ports to be used
1593 CONFIG_SH_ETHER_PHY_ADDR
1594 Define the ETH PHY's address
1596 CONFIG_SH_ETHER_CACHE_WRITEBACK
1597 If this option is set, the driver enables cache flush.
1601 Support for PWM modul on the imx6.
1605 Support TPM devices.
1608 Support for i2c bus TPM devices. Only one device
1609 per system is supported at this time.
1611 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1612 Define the the i2c bus number for the TPM device
1614 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1615 Define the TPM's address on the i2c bus
1617 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1618 Define the burst count bytes upper limit
1620 CONFIG_TPM_ATMEL_TWI
1621 Support for Atmel TWI TPM device. Requires I2C support.
1624 Support for generic parallel port TPM devices. Only one device
1625 per system is supported at this time.
1627 CONFIG_TPM_TIS_BASE_ADDRESS
1628 Base address where the generic TPM device is mapped
1629 to. Contemporary x86 systems usually map it at
1633 Add tpm monitor functions.
1634 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1635 provides monitor access to authorized functions.
1638 Define this to enable the TPM support library which provides
1639 functional interfaces to some TPM commands.
1640 Requires support for a TPM device.
1642 CONFIG_TPM_AUTH_SESSIONS
1643 Define this to enable authorized functions in the TPM library.
1644 Requires CONFIG_TPM and CONFIG_SHA1.
1647 At the moment only the UHCI host controller is
1648 supported (PIP405, MIP405, MPC5200); define
1649 CONFIG_USB_UHCI to enable it.
1650 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1651 and define CONFIG_USB_STORAGE to enable the USB
1654 Supported are USB Keyboards and USB Floppy drives
1656 MPC5200 USB requires additional defines:
1658 for 528 MHz Clock: 0x0001bbbb
1662 for differential drivers: 0x00001000
1663 for single ended drivers: 0x00005000
1664 for differential drivers on PSC3: 0x00000100
1665 for single ended drivers on PSC3: 0x00004100
1666 CONFIG_SYS_USB_EVENT_POLL
1667 May be defined to allow interrupt polling
1668 instead of using asynchronous interrupts
1670 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1671 txfilltuning field in the EHCI controller on reset.
1673 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1674 HW module registers.
1677 Define the below if you wish to use the USB console.
1678 Once firmware is rebuilt from a serial console issue the
1679 command "setenv stdin usbtty; setenv stdout usbtty" and
1680 attach your USB cable. The Unix command "dmesg" should print
1681 it has found a new device. The environment variable usbtty
1682 can be set to gserial or cdc_acm to enable your device to
1683 appear to a USB host as a Linux gserial device or a
1684 Common Device Class Abstract Control Model serial device.
1685 If you select usbtty = gserial you should be able to enumerate
1687 # modprobe usbserial vendor=0xVendorID product=0xProductID
1688 else if using cdc_acm, simply setting the environment
1689 variable usbtty to be cdc_acm should suffice. The following
1690 might be defined in YourBoardName.h
1693 Define this to build a UDC device
1696 Define this to have a tty type of device available to
1697 talk to the UDC device
1700 Define this to enable the high speed support for usb
1701 device and usbtty. If this feature is enabled, a routine
1702 int is_usbd_high_speed(void)
1703 also needs to be defined by the driver to dynamically poll
1704 whether the enumeration has succeded at high speed or full
1707 CONFIG_SYS_CONSOLE_IS_IN_ENV
1708 Define this if you want stdin, stdout &/or stderr to
1712 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1713 Derive USB clock from external clock "blah"
1714 - CONFIG_SYS_USB_EXTC_CLK 0x02
1716 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1717 Derive USB clock from brgclk
1718 - CONFIG_SYS_USB_BRG_CLK 0x04
1720 If you have a USB-IF assigned VendorID then you may wish to
1721 define your own vendor specific values either in BoardName.h
1722 or directly in usbd_vendor_info.h. If you don't define
1723 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1724 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1725 should pretend to be a Linux device to it's target host.
1727 CONFIG_USBD_MANUFACTURER
1728 Define this string as the name of your company for
1729 - CONFIG_USBD_MANUFACTURER "my company"
1731 CONFIG_USBD_PRODUCT_NAME
1732 Define this string as the name of your product
1733 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1735 CONFIG_USBD_VENDORID
1736 Define this as your assigned Vendor ID from the USB
1737 Implementors Forum. This *must* be a genuine Vendor ID
1738 to avoid polluting the USB namespace.
1739 - CONFIG_USBD_VENDORID 0xFFFF
1741 CONFIG_USBD_PRODUCTID
1742 Define this as the unique Product ID
1744 - CONFIG_USBD_PRODUCTID 0xFFFF
1746 - ULPI Layer Support:
1747 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1748 the generic ULPI layer. The generic layer accesses the ULPI PHY
1749 via the platform viewport, so you need both the genric layer and
1750 the viewport enabled. Currently only Chipidea/ARC based
1751 viewport is supported.
1752 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1753 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1754 If your ULPI phy needs a different reference clock than the
1755 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1756 the appropriate value in Hz.
1759 The MMC controller on the Intel PXA is supported. To
1760 enable this define CONFIG_MMC. The MMC can be
1761 accessed from the boot prompt by mapping the device
1762 to physical memory similar to flash. Command line is
1763 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1764 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1767 Support for Renesas on-chip MMCIF controller
1769 CONFIG_SH_MMCIF_ADDR
1770 Define the base address of MMCIF registers
1773 Define the clock frequency for MMCIF
1776 Enable the generic MMC driver
1778 CONFIG_SUPPORT_EMMC_BOOT
1779 Enable some additional features of the eMMC boot partitions.
1781 CONFIG_SUPPORT_EMMC_RPMB
1782 Enable the commands for reading, writing and programming the
1783 key for the Replay Protection Memory Block partition in eMMC.
1785 - USB Device Firmware Update (DFU) class support:
1787 This enables the USB portion of the DFU USB class
1790 This enables the command "dfu" which is used to have
1791 U-Boot create a DFU class device via USB. This command
1792 requires that the "dfu_alt_info" environment variable be
1793 set and define the alt settings to expose to the host.
1796 This enables support for exposing (e)MMC devices via DFU.
1799 This enables support for exposing NAND devices via DFU.
1802 This enables support for exposing RAM via DFU.
1803 Note: DFU spec refer to non-volatile memory usage, but
1804 allow usages beyond the scope of spec - here RAM usage,
1805 one that would help mostly the developer.
1807 CONFIG_SYS_DFU_DATA_BUF_SIZE
1808 Dfu transfer uses a buffer before writing data to the
1809 raw storage device. Make the size (in bytes) of this buffer
1810 configurable. The size of this buffer is also configurable
1811 through the "dfu_bufsiz" environment variable.
1813 CONFIG_SYS_DFU_MAX_FILE_SIZE
1814 When updating files rather than the raw storage device,
1815 we use a static buffer to copy the file into and then write
1816 the buffer once we've been given the whole file. Define
1817 this to the maximum filesize (in bytes) for the buffer.
1818 Default is 4 MiB if undefined.
1820 DFU_DEFAULT_POLL_TIMEOUT
1821 Poll timeout [ms], is the timeout a device can send to the
1822 host. The host must wait for this timeout before sending
1823 a subsequent DFU_GET_STATUS request to the device.
1825 DFU_MANIFEST_POLL_TIMEOUT
1826 Poll timeout [ms], which the device sends to the host when
1827 entering dfuMANIFEST state. Host waits this timeout, before
1828 sending again an USB request to the device.
1830 - USB Device Android Fastboot support:
1832 This enables the command "fastboot" which enables the Android
1833 fastboot mode for the platform's USB device. Fastboot is a USB
1834 protocol for downloading images, flashing and device control
1835 used on Android devices.
1836 See doc/README.android-fastboot for more information.
1838 CONFIG_ANDROID_BOOT_IMAGE
1839 This enables support for booting images which use the Android
1840 image format header.
1842 CONFIG_USB_FASTBOOT_BUF_ADDR
1843 The fastboot protocol requires a large memory buffer for
1844 downloads. Define this to the starting RAM address to use for
1847 CONFIG_USB_FASTBOOT_BUF_SIZE
1848 The fastboot protocol requires a large memory buffer for
1849 downloads. This buffer should be as large as possible for a
1850 platform. Define this to the size available RAM for fastboot.
1852 CONFIG_FASTBOOT_FLASH
1853 The fastboot protocol includes a "flash" command for writing
1854 the downloaded image to a non-volatile storage device. Define
1855 this to enable the "fastboot flash" command.
1857 CONFIG_FASTBOOT_FLASH_MMC_DEV
1858 The fastboot "flash" command requires additional information
1859 regarding the non-volatile storage device. Define this to
1860 the eMMC device that fastboot should use to store the image.
1862 CONFIG_FASTBOOT_GPT_NAME
1863 The fastboot "flash" command supports writing the downloaded
1864 image to the Protective MBR and the Primary GUID Partition
1865 Table. (Additionally, this downloaded image is post-processed
1866 to generate and write the Backup GUID Partition Table.)
1867 This occurs when the specified "partition name" on the
1868 "fastboot flash" command line matches this value.
1869 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1871 - Journaling Flash filesystem support:
1872 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1873 CONFIG_JFFS2_NAND_DEV
1874 Define these for a default partition on a NAND device
1876 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1877 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1878 Define these for a default partition on a NOR device
1880 CONFIG_SYS_JFFS_CUSTOM_PART
1881 Define this to create an own partition. You have to provide a
1882 function struct part_info* jffs2_part_info(int part_num)
1884 If you define only one JFFS2 partition you may also want to
1885 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1886 to disable the command chpart. This is the default when you
1887 have not defined a custom partition
1889 - FAT(File Allocation Table) filesystem write function support:
1892 Define this to enable support for saving memory data as a
1893 file in FAT formatted partition.
1895 This will also enable the command "fatwrite" enabling the
1896 user to write files to FAT.
1898 CBFS (Coreboot Filesystem) support
1901 Define this to enable support for reading from a Coreboot
1902 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1905 - FAT(File Allocation Table) filesystem cluster size:
1906 CONFIG_FS_FAT_MAX_CLUSTSIZE
1908 Define the max cluster size for fat operations else
1909 a default value of 65536 will be defined.
1914 Define this to enable standard (PC-Style) keyboard
1918 Standard PC keyboard driver with US (is default) and
1919 GERMAN key layout (switch via environment 'keymap=de') support.
1920 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1921 for cfb_console. Supports cursor blinking.
1924 Enables a Chrome OS keyboard using the CROS_EC interface.
1925 This uses CROS_EC to communicate with a second microcontroller
1926 which provides key scans on request.
1931 Define this to enable video support (for output to
1934 CONFIG_VIDEO_CT69000
1936 Enable Chips & Technologies 69000 Video chip
1938 CONFIG_VIDEO_SMI_LYNXEM
1939 Enable Silicon Motion SMI 712/710/810 Video chip. The
1940 video output is selected via environment 'videoout'
1941 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1944 For the CT69000 and SMI_LYNXEM drivers, videomode is
1945 selected via environment 'videomode'. Two different ways
1947 - "videomode=num" 'num' is a standard LiLo mode numbers.
1948 Following standard modes are supported (* is default):
1950 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1951 -------------+---------------------------------------------
1952 8 bits | 0x301* 0x303 0x305 0x161 0x307
1953 15 bits | 0x310 0x313 0x316 0x162 0x319
1954 16 bits | 0x311 0x314 0x317 0x163 0x31A
1955 24 bits | 0x312 0x315 0x318 ? 0x31B
1956 -------------+---------------------------------------------
1957 (i.e. setenv videomode 317; saveenv; reset;)
1959 - "videomode=bootargs" all the video parameters are parsed
1960 from the bootargs. (See drivers/video/videomodes.c)
1963 CONFIG_VIDEO_SED13806
1964 Enable Epson SED13806 driver. This driver supports 8bpp
1965 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1966 or CONFIG_VIDEO_SED13806_16BPP
1969 Enable the Freescale DIU video driver. Reference boards for
1970 SOCs that have a DIU should define this macro to enable DIU
1971 support, and should also define these other macros:
1977 CONFIG_VIDEO_SW_CURSOR
1978 CONFIG_VGA_AS_SINGLE_DEVICE
1980 CONFIG_VIDEO_BMP_LOGO
1982 The DIU driver will look for the 'video-mode' environment
1983 variable, and if defined, enable the DIU as a console during
1984 boot. See the documentation file README.video for a
1985 description of this variable.
1991 Define this to enable a custom keyboard support.
1992 This simply calls drv_keyboard_init() which must be
1993 defined in your board-specific files.
1994 The only board using this so far is RBC823.
1996 - LCD Support: CONFIG_LCD
1998 Define this to enable LCD support (for output to LCD
1999 display); also select one of the supported displays
2000 by defining one of these:
2004 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2006 CONFIG_NEC_NL6448AC33:
2008 NEC NL6448AC33-18. Active, color, single scan.
2010 CONFIG_NEC_NL6448BC20
2012 NEC NL6448BC20-08. 6.5", 640x480.
2013 Active, color, single scan.
2015 CONFIG_NEC_NL6448BC33_54
2017 NEC NL6448BC33-54. 10.4", 640x480.
2018 Active, color, single scan.
2022 Sharp 320x240. Active, color, single scan.
2023 It isn't 16x9, and I am not sure what it is.
2025 CONFIG_SHARP_LQ64D341
2027 Sharp LQ64D341 display, 640x480.
2028 Active, color, single scan.
2032 HLD1045 display, 640x480.
2033 Active, color, single scan.
2037 Optrex CBL50840-2 NF-FW 99 22 M5
2039 Hitachi LMG6912RPFC-00T
2043 320x240. Black & white.
2045 Normally display is black on white background; define
2046 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2048 CONFIG_LCD_ALIGNMENT
2050 Normally the LCD is page-aligned (typically 4KB). If this is
2051 defined then the LCD will be aligned to this value instead.
2052 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2053 here, since it is cheaper to change data cache settings on
2054 a per-section basis.
2056 CONFIG_CONSOLE_SCROLL_LINES
2058 When the console need to be scrolled, this is the number of
2059 lines to scroll by. It defaults to 1. Increasing this makes
2060 the console jump but can help speed up operation when scrolling
2065 Sometimes, for example if the display is mounted in portrait
2066 mode or even if it's mounted landscape but rotated by 180degree,
2067 we need to rotate our content of the display relative to the
2068 framebuffer, so that user can read the messages which are
2070 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2071 initialized with a given rotation from "vl_rot" out of
2072 "vidinfo_t" which is provided by the board specific code.
2073 The value for vl_rot is coded as following (matching to
2074 fbcon=rotate:<n> linux-kernel commandline):
2075 0 = no rotation respectively 0 degree
2076 1 = 90 degree rotation
2077 2 = 180 degree rotation
2078 3 = 270 degree rotation
2080 If CONFIG_LCD_ROTATION is not defined, the console will be
2081 initialized with 0degree rotation.
2085 Support drawing of RLE8-compressed bitmaps on the LCD.
2089 Enables an 'i2c edid' command which can read EDID
2090 information over I2C from an attached LCD display.
2092 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2094 If this option is set, the environment is checked for
2095 a variable "splashimage". If found, the usual display
2096 of logo, copyright and system information on the LCD
2097 is suppressed and the BMP image at the address
2098 specified in "splashimage" is loaded instead. The
2099 console is redirected to the "nulldev", too. This
2100 allows for a "silent" boot where a splash screen is
2101 loaded very quickly after power-on.
2103 CONFIG_SPLASHIMAGE_GUARD
2105 If this option is set, then U-Boot will prevent the environment
2106 variable "splashimage" from being set to a problematic address
2107 (see README.displaying-bmps).
2108 This option is useful for targets where, due to alignment
2109 restrictions, an improperly aligned BMP image will cause a data
2110 abort. If you think you will not have problems with unaligned
2111 accesses (for example because your toolchain prevents them)
2112 there is no need to set this option.
2114 CONFIG_SPLASH_SCREEN_ALIGN
2116 If this option is set the splash image can be freely positioned
2117 on the screen. Environment variable "splashpos" specifies the
2118 position as "x,y". If a positive number is given it is used as
2119 number of pixel from left/top. If a negative number is given it
2120 is used as number of pixel from right/bottom. You can also
2121 specify 'm' for centering the image.
2124 setenv splashpos m,m
2125 => image at center of screen
2127 setenv splashpos 30,20
2128 => image at x = 30 and y = 20
2130 setenv splashpos -10,m
2131 => vertically centered image
2132 at x = dspWidth - bmpWidth - 9
2134 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2136 If this option is set, additionally to standard BMP
2137 images, gzipped BMP images can be displayed via the
2138 splashscreen support or the bmp command.
2140 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2142 If this option is set, 8-bit RLE compressed BMP images
2143 can be displayed via the splashscreen support or the
2146 - Do compressing for memory range:
2149 If this option is set, it would use zlib deflate method
2150 to compress the specified memory at its best effort.
2152 - Compression support:
2155 Enabled by default to support gzip compressed images.
2159 If this option is set, support for bzip2 compressed
2160 images is included. If not, only uncompressed and gzip
2161 compressed images are supported.
2163 NOTE: the bzip2 algorithm requires a lot of RAM, so
2164 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2169 If this option is set, support for lzma compressed
2172 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2173 requires an amount of dynamic memory that is given by the
2176 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2178 Where lc and lp stand for, respectively, Literal context bits
2179 and Literal pos bits.
2181 This value is upper-bounded by 14MB in the worst case. Anyway,
2182 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2183 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2184 a very small buffer.
2186 Use the lzmainfo tool to determinate the lc and lp values and
2187 then calculate the amount of needed dynamic memory (ensuring
2188 the appropriate CONFIG_SYS_MALLOC_LEN value).
2192 If this option is set, support for LZO compressed images
2198 The address of PHY on MII bus.
2200 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2202 The clock frequency of the MII bus
2206 If this option is set, support for speed/duplex
2207 detection of gigabit PHY is included.
2209 CONFIG_PHY_RESET_DELAY
2211 Some PHY like Intel LXT971A need extra delay after
2212 reset before any MII register access is possible.
2213 For such PHY, set this option to the usec delay
2214 required. (minimum 300usec for LXT971A)
2216 CONFIG_PHY_CMD_DELAY (ppc4xx)
2218 Some PHY like Intel LXT971A need extra delay after
2219 command issued before MII status register can be read
2224 Define a default value for the IP address to use for
2225 the default Ethernet interface, in case this is not
2226 determined through e.g. bootp.
2227 (Environment variable "ipaddr")
2229 - Server IP address:
2232 Defines a default value for the IP address of a TFTP
2233 server to contact when using the "tftboot" command.
2234 (Environment variable "serverip")
2236 CONFIG_KEEP_SERVERADDR
2238 Keeps the server's MAC address, in the env 'serveraddr'
2239 for passing to bootargs (like Linux's netconsole option)
2241 - Gateway IP address:
2244 Defines a default value for the IP address of the
2245 default router where packets to other networks are
2247 (Environment variable "gatewayip")
2252 Defines a default value for the subnet mask (or
2253 routing prefix) which is used to determine if an IP
2254 address belongs to the local subnet or needs to be
2255 forwarded through a router.
2256 (Environment variable "netmask")
2258 - Multicast TFTP Mode:
2261 Defines whether you want to support multicast TFTP as per
2262 rfc-2090; for example to work with atftp. Lets lots of targets
2263 tftp down the same boot image concurrently. Note: the Ethernet
2264 driver in use must provide a function: mcast() to join/leave a
2267 - BOOTP Recovery Mode:
2268 CONFIG_BOOTP_RANDOM_DELAY
2270 If you have many targets in a network that try to
2271 boot using BOOTP, you may want to avoid that all
2272 systems send out BOOTP requests at precisely the same
2273 moment (which would happen for instance at recovery
2274 from a power failure, when all systems will try to
2275 boot, thus flooding the BOOTP server. Defining
2276 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2277 inserted before sending out BOOTP requests. The
2278 following delays are inserted then:
2280 1st BOOTP request: delay 0 ... 1 sec
2281 2nd BOOTP request: delay 0 ... 2 sec
2282 3rd BOOTP request: delay 0 ... 4 sec
2284 BOOTP requests: delay 0 ... 8 sec
2286 CONFIG_BOOTP_ID_CACHE_SIZE
2288 BOOTP packets are uniquely identified using a 32-bit ID. The
2289 server will copy the ID from client requests to responses and
2290 U-Boot will use this to determine if it is the destination of
2291 an incoming response. Some servers will check that addresses
2292 aren't in use before handing them out (usually using an ARP
2293 ping) and therefore take up to a few hundred milliseconds to
2294 respond. Network congestion may also influence the time it
2295 takes for a response to make it back to the client. If that
2296 time is too long, U-Boot will retransmit requests. In order
2297 to allow earlier responses to still be accepted after these
2298 retransmissions, U-Boot's BOOTP client keeps a small cache of
2299 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2300 cache. The default is to keep IDs for up to four outstanding
2301 requests. Increasing this will allow U-Boot to accept offers
2302 from a BOOTP client in networks with unusually high latency.
2304 - BOOTP Random transaction ID:
2305 CONFIG_BOOTP_RANDOM_ID
2307 The standard algorithm to generate a DHCP/BOOTP transaction ID
2308 by using the MAC address and the current time stamp may not
2309 quite unlikely produce duplicate transaction IDs from different
2310 clients in the same network. This option creates a transaction
2311 ID using the rand() function. Provided that the RNG has been
2312 seeded well, this should guarantee unique transaction IDs
2315 - DHCP Advanced Options:
2316 You can fine tune the DHCP functionality by defining
2317 CONFIG_BOOTP_* symbols:
2319 CONFIG_BOOTP_SUBNETMASK
2320 CONFIG_BOOTP_GATEWAY
2321 CONFIG_BOOTP_HOSTNAME
2322 CONFIG_BOOTP_NISDOMAIN
2323 CONFIG_BOOTP_BOOTPATH
2324 CONFIG_BOOTP_BOOTFILESIZE
2327 CONFIG_BOOTP_SEND_HOSTNAME
2328 CONFIG_BOOTP_NTPSERVER
2329 CONFIG_BOOTP_TIMEOFFSET
2330 CONFIG_BOOTP_VENDOREX
2331 CONFIG_BOOTP_MAY_FAIL
2333 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2334 environment variable, not the BOOTP server.
2336 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2337 after the configured retry count, the call will fail
2338 instead of starting over. This can be used to fail over
2339 to Link-local IP address configuration if the DHCP server
2342 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2343 serverip from a DHCP server, it is possible that more
2344 than one DNS serverip is offered to the client.
2345 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2346 serverip will be stored in the additional environment
2347 variable "dnsip2". The first DNS serverip is always
2348 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2351 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2352 to do a dynamic update of a DNS server. To do this, they
2353 need the hostname of the DHCP requester.
2354 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2355 of the "hostname" environment variable is passed as
2356 option 12 to the DHCP server.
2358 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2360 A 32bit value in microseconds for a delay between
2361 receiving a "DHCP Offer" and sending the "DHCP Request".
2362 This fixes a problem with certain DHCP servers that don't
2363 respond 100% of the time to a "DHCP request". E.g. On an
2364 AT91RM9200 processor running at 180MHz, this delay needed
2365 to be *at least* 15,000 usec before a Windows Server 2003
2366 DHCP server would reply 100% of the time. I recommend at
2367 least 50,000 usec to be safe. The alternative is to hope
2368 that one of the retries will be successful but note that
2369 the DHCP timeout and retry process takes a longer than
2372 - Link-local IP address negotiation:
2373 Negotiate with other link-local clients on the local network
2374 for an address that doesn't require explicit configuration.
2375 This is especially useful if a DHCP server cannot be guaranteed
2376 to exist in all environments that the device must operate.
2378 See doc/README.link-local for more information.
2381 CONFIG_CDP_DEVICE_ID
2383 The device id used in CDP trigger frames.
2385 CONFIG_CDP_DEVICE_ID_PREFIX
2387 A two character string which is prefixed to the MAC address
2392 A printf format string which contains the ascii name of
2393 the port. Normally is set to "eth%d" which sets
2394 eth0 for the first Ethernet, eth1 for the second etc.
2396 CONFIG_CDP_CAPABILITIES
2398 A 32bit integer which indicates the device capabilities;
2399 0x00000010 for a normal host which does not forwards.
2403 An ascii string containing the version of the software.
2407 An ascii string containing the name of the platform.
2411 A 32bit integer sent on the trigger.
2413 CONFIG_CDP_POWER_CONSUMPTION
2415 A 16bit integer containing the power consumption of the
2416 device in .1 of milliwatts.
2418 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2420 A byte containing the id of the VLAN.
2422 - Status LED: CONFIG_STATUS_LED
2424 Several configurations allow to display the current
2425 status using a LED. For instance, the LED will blink
2426 fast while running U-Boot code, stop blinking as
2427 soon as a reply to a BOOTP request was received, and
2428 start blinking slow once the Linux kernel is running
2429 (supported by a status LED driver in the Linux
2430 kernel). Defining CONFIG_STATUS_LED enables this
2436 The status LED can be connected to a GPIO pin.
2437 In such cases, the gpio_led driver can be used as a
2438 status LED backend implementation. Define CONFIG_GPIO_LED
2439 to include the gpio_led driver in the U-Boot binary.
2441 CONFIG_GPIO_LED_INVERTED_TABLE
2442 Some GPIO connected LEDs may have inverted polarity in which
2443 case the GPIO high value corresponds to LED off state and
2444 GPIO low value corresponds to LED on state.
2445 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2446 with a list of GPIO LEDs that have inverted polarity.
2448 - CAN Support: CONFIG_CAN_DRIVER
2450 Defining CONFIG_CAN_DRIVER enables CAN driver support
2451 on those systems that support this (optional)
2452 feature, like the TQM8xxL modules.
2454 - I2C Support: CONFIG_SYS_I2C
2456 This enable the NEW i2c subsystem, and will allow you to use
2457 i2c commands at the u-boot command line (as long as you set
2458 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2459 based realtime clock chips or other i2c devices. See
2460 common/cmd_i2c.c for a description of the command line
2463 ported i2c driver to the new framework:
2464 - drivers/i2c/soft_i2c.c:
2465 - activate first bus with CONFIG_SYS_I2C_SOFT define
2466 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2467 for defining speed and slave address
2468 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2469 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2470 for defining speed and slave address
2471 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2472 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2473 for defining speed and slave address
2474 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2475 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2476 for defining speed and slave address
2478 - drivers/i2c/fsl_i2c.c:
2479 - activate i2c driver with CONFIG_SYS_I2C_FSL
2480 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2481 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2482 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2484 - If your board supports a second fsl i2c bus, define
2485 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2486 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2487 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2490 - drivers/i2c/tegra_i2c.c:
2491 - activate this driver with CONFIG_SYS_I2C_TEGRA
2492 - This driver adds 4 i2c buses with a fix speed from
2493 100000 and the slave addr 0!
2495 - drivers/i2c/ppc4xx_i2c.c
2496 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2497 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2498 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2500 - drivers/i2c/i2c_mxc.c
2501 - activate this driver with CONFIG_SYS_I2C_MXC
2502 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2503 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2504 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2505 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2506 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2507 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2508 If those defines are not set, default value is 100000
2509 for speed, and 0 for slave.
2510 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2511 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2513 - drivers/i2c/rcar_i2c.c:
2514 - activate this driver with CONFIG_SYS_I2C_RCAR
2515 - This driver adds 4 i2c buses
2517 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2518 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2519 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2520 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2521 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2522 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2523 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2524 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2525 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2527 - drivers/i2c/sh_i2c.c:
2528 - activate this driver with CONFIG_SYS_I2C_SH
2529 - This driver adds from 2 to 5 i2c buses
2531 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2532 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2533 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2534 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2535 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2536 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2537 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2538 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2539 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2540 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2541 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2542 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2543 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2545 - drivers/i2c/omap24xx_i2c.c
2546 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2547 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2548 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2549 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2550 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2551 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2552 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2553 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2554 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2555 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2556 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2558 - drivers/i2c/zynq_i2c.c
2559 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2560 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2561 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2563 - drivers/i2c/s3c24x0_i2c.c:
2564 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2565 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2566 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2567 with a fix speed from 100000 and the slave addr 0!
2569 - drivers/i2c/ihs_i2c.c
2570 - activate this driver with CONFIG_SYS_I2C_IHS
2571 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2572 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2573 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2574 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2575 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2576 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2577 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2578 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2579 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2580 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2581 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2582 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2586 CONFIG_SYS_NUM_I2C_BUSES
2587 Hold the number of i2c buses you want to use. If you
2588 don't use/have i2c muxes on your i2c bus, this
2589 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2592 CONFIG_SYS_I2C_DIRECT_BUS
2593 define this, if you don't use i2c muxes on your hardware.
2594 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2597 CONFIG_SYS_I2C_MAX_HOPS
2598 define how many muxes are maximal consecutively connected
2599 on one i2c bus. If you not use i2c muxes, omit this
2602 CONFIG_SYS_I2C_BUSES
2603 hold a list of buses you want to use, only used if
2604 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2605 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2606 CONFIG_SYS_NUM_I2C_BUSES = 9:
2608 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2609 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2610 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2612 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2613 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2614 {1, {I2C_NULL_HOP}}, \
2615 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2616 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2620 bus 0 on adapter 0 without a mux
2621 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2622 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2623 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2624 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2625 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2626 bus 6 on adapter 1 without a mux
2627 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2628 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2630 If you do not have i2c muxes on your board, omit this define.
2632 - Legacy I2C Support: CONFIG_HARD_I2C
2634 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2635 provides the following compelling advantages:
2637 - more than one i2c adapter is usable
2638 - approved multibus support
2639 - better i2c mux support
2641 ** Please consider updating your I2C driver now. **
2643 These enable legacy I2C serial bus commands. Defining
2644 CONFIG_HARD_I2C will include the appropriate I2C driver
2645 for the selected CPU.
2647 This will allow you to use i2c commands at the u-boot
2648 command line (as long as you set CONFIG_CMD_I2C in
2649 CONFIG_COMMANDS) and communicate with i2c based realtime
2650 clock chips. See common/cmd_i2c.c for a description of the
2651 command line interface.
2653 CONFIG_HARD_I2C selects a hardware I2C controller.
2655 There are several other quantities that must also be
2656 defined when you define CONFIG_HARD_I2C.
2658 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2659 to be the frequency (in Hz) at which you wish your i2c bus
2660 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2661 the CPU's i2c node address).
2663 Now, the u-boot i2c code for the mpc8xx
2664 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2665 and so its address should therefore be cleared to 0 (See,
2666 eg, MPC823e User's Manual p.16-473). So, set
2667 CONFIG_SYS_I2C_SLAVE to 0.
2669 CONFIG_SYS_I2C_INIT_MPC5XXX
2671 When a board is reset during an i2c bus transfer
2672 chips might think that the current transfer is still
2673 in progress. Reset the slave devices by sending start
2674 commands until the slave device responds.
2676 That's all that's required for CONFIG_HARD_I2C.
2678 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2679 then the following macros need to be defined (examples are
2680 from include/configs/lwmon.h):
2684 (Optional). Any commands necessary to enable the I2C
2685 controller or configure ports.
2687 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2691 (Only for MPC8260 CPU). The I/O port to use (the code
2692 assumes both bits are on the same port). Valid values
2693 are 0..3 for ports A..D.
2697 The code necessary to make the I2C data line active
2698 (driven). If the data line is open collector, this
2701 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2705 The code necessary to make the I2C data line tri-stated
2706 (inactive). If the data line is open collector, this
2709 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2713 Code that returns true if the I2C data line is high,
2716 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2720 If <bit> is true, sets the I2C data line high. If it
2721 is false, it clears it (low).
2723 eg: #define I2C_SDA(bit) \
2724 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2725 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2729 If <bit> is true, sets the I2C clock line high. If it
2730 is false, it clears it (low).
2732 eg: #define I2C_SCL(bit) \
2733 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2734 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2738 This delay is invoked four times per clock cycle so this
2739 controls the rate of data transfer. The data rate thus
2740 is 1 / (I2C_DELAY * 4). Often defined to be something
2743 #define I2C_DELAY udelay(2)
2745 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2747 If your arch supports the generic GPIO framework (asm/gpio.h),
2748 then you may alternatively define the two GPIOs that are to be
2749 used as SCL / SDA. Any of the previous I2C_xxx macros will
2750 have GPIO-based defaults assigned to them as appropriate.
2752 You should define these to the GPIO value as given directly to
2753 the generic GPIO functions.
2755 CONFIG_SYS_I2C_INIT_BOARD
2757 When a board is reset during an i2c bus transfer
2758 chips might think that the current transfer is still
2759 in progress. On some boards it is possible to access
2760 the i2c SCLK line directly, either by using the
2761 processor pin as a GPIO or by having a second pin
2762 connected to the bus. If this option is defined a
2763 custom i2c_init_board() routine in boards/xxx/board.c
2764 is run early in the boot sequence.
2766 CONFIG_SYS_I2C_BOARD_LATE_INIT
2768 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2769 defined a custom i2c_board_late_init() routine in
2770 boards/xxx/board.c is run AFTER the operations in i2c_init()
2771 is completed. This callpoint can be used to unreset i2c bus
2772 using CPU i2c controller register accesses for CPUs whose i2c
2773 controller provide such a method. It is called at the end of
2774 i2c_init() to allow i2c_init operations to setup the i2c bus
2775 controller on the CPU (e.g. setting bus speed & slave address).
2777 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2779 This option enables configuration of bi_iic_fast[] flags
2780 in u-boot bd_info structure based on u-boot environment
2781 variable "i2cfast". (see also i2cfast)
2783 CONFIG_I2C_MULTI_BUS
2785 This option allows the use of multiple I2C buses, each of which
2786 must have a controller. At any point in time, only one bus is
2787 active. To switch to a different bus, use the 'i2c dev' command.
2788 Note that bus numbering is zero-based.
2790 CONFIG_SYS_I2C_NOPROBES
2792 This option specifies a list of I2C devices that will be skipped
2793 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2794 is set, specify a list of bus-device pairs. Otherwise, specify
2795 a 1D array of device addresses
2798 #undef CONFIG_I2C_MULTI_BUS
2799 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2801 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2803 #define CONFIG_I2C_MULTI_BUS
2804 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2806 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2808 CONFIG_SYS_SPD_BUS_NUM
2810 If defined, then this indicates the I2C bus number for DDR SPD.
2811 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2813 CONFIG_SYS_RTC_BUS_NUM
2815 If defined, then this indicates the I2C bus number for the RTC.
2816 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2818 CONFIG_SYS_DTT_BUS_NUM
2820 If defined, then this indicates the I2C bus number for the DTT.
2821 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2823 CONFIG_SYS_I2C_DTT_ADDR:
2825 If defined, specifies the I2C address of the DTT device.
2826 If not defined, then U-Boot uses predefined value for
2827 specified DTT device.
2829 CONFIG_SOFT_I2C_READ_REPEATED_START
2831 defining this will force the i2c_read() function in
2832 the soft_i2c driver to perform an I2C repeated start
2833 between writing the address pointer and reading the
2834 data. If this define is omitted the default behaviour
2835 of doing a stop-start sequence will be used. Most I2C
2836 devices can use either method, but some require one or
2839 - SPI Support: CONFIG_SPI
2841 Enables SPI driver (so far only tested with
2842 SPI EEPROM, also an instance works with Crystal A/D and
2843 D/As on the SACSng board)
2847 Enables the driver for SPI controller on SuperH. Currently
2848 only SH7757 is supported.
2852 Enables extended (16-bit) SPI EEPROM addressing.
2853 (symmetrical to CONFIG_I2C_X)
2857 Enables a software (bit-bang) SPI driver rather than
2858 using hardware support. This is a general purpose
2859 driver that only requires three general I/O port pins
2860 (two outputs, one input) to function. If this is
2861 defined, the board configuration must define several
2862 SPI configuration items (port pins to use, etc). For
2863 an example, see include/configs/sacsng.h.
2867 Enables a hardware SPI driver for general-purpose reads
2868 and writes. As with CONFIG_SOFT_SPI, the board configuration
2869 must define a list of chip-select function pointers.
2870 Currently supported on some MPC8xxx processors. For an
2871 example, see include/configs/mpc8349emds.h.
2875 Enables the driver for the SPI controllers on i.MX and MXC
2876 SoCs. Currently i.MX31/35/51 are supported.
2878 CONFIG_SYS_SPI_MXC_WAIT
2879 Timeout for waiting until spi transfer completed.
2880 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2882 - FPGA Support: CONFIG_FPGA
2884 Enables FPGA subsystem.
2886 CONFIG_FPGA_<vendor>
2888 Enables support for specific chip vendors.
2891 CONFIG_FPGA_<family>
2893 Enables support for FPGA family.
2894 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2898 Specify the number of FPGA devices to support.
2900 CONFIG_CMD_FPGA_LOADMK
2902 Enable support for fpga loadmk command
2904 CONFIG_CMD_FPGA_LOADP
2906 Enable support for fpga loadp command - load partial bitstream
2908 CONFIG_CMD_FPGA_LOADBP
2910 Enable support for fpga loadbp command - load partial bitstream
2913 CONFIG_SYS_FPGA_PROG_FEEDBACK
2915 Enable printing of hash marks during FPGA configuration.
2917 CONFIG_SYS_FPGA_CHECK_BUSY
2919 Enable checks on FPGA configuration interface busy
2920 status by the configuration function. This option
2921 will require a board or device specific function to
2926 If defined, a function that provides delays in the FPGA
2927 configuration driver.
2929 CONFIG_SYS_FPGA_CHECK_CTRLC
2930 Allow Control-C to interrupt FPGA configuration
2932 CONFIG_SYS_FPGA_CHECK_ERROR
2934 Check for configuration errors during FPGA bitfile
2935 loading. For example, abort during Virtex II
2936 configuration if the INIT_B line goes low (which
2937 indicated a CRC error).
2939 CONFIG_SYS_FPGA_WAIT_INIT
2941 Maximum time to wait for the INIT_B line to de-assert
2942 after PROB_B has been de-asserted during a Virtex II
2943 FPGA configuration sequence. The default time is 500
2946 CONFIG_SYS_FPGA_WAIT_BUSY
2948 Maximum time to wait for BUSY to de-assert during
2949 Virtex II FPGA configuration. The default is 5 ms.
2951 CONFIG_SYS_FPGA_WAIT_CONFIG
2953 Time to wait after FPGA configuration. The default is
2956 - Configuration Management:
2959 Some SoCs need special image types (e.g. U-Boot binary
2960 with a special header) as build targets. By defining
2961 CONFIG_BUILD_TARGET in the SoC / board header, this
2962 special image will be automatically built upon calling
2967 If defined, this string will be added to the U-Boot
2968 version information (U_BOOT_VERSION)
2970 - Vendor Parameter Protection:
2972 U-Boot considers the values of the environment
2973 variables "serial#" (Board Serial Number) and
2974 "ethaddr" (Ethernet Address) to be parameters that
2975 are set once by the board vendor / manufacturer, and
2976 protects these variables from casual modification by
2977 the user. Once set, these variables are read-only,
2978 and write or delete attempts are rejected. You can
2979 change this behaviour:
2981 If CONFIG_ENV_OVERWRITE is #defined in your config
2982 file, the write protection for vendor parameters is
2983 completely disabled. Anybody can change or delete
2986 Alternatively, if you define _both_ an ethaddr in the
2987 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2988 Ethernet address is installed in the environment,
2989 which can be changed exactly ONCE by the user. [The
2990 serial# is unaffected by this, i. e. it remains
2993 The same can be accomplished in a more flexible way
2994 for any variable by configuring the type of access
2995 to allow for those variables in the ".flags" variable
2996 or define CONFIG_ENV_FLAGS_LIST_STATIC.
3001 Define this variable to enable the reservation of
3002 "protected RAM", i. e. RAM which is not overwritten
3003 by U-Boot. Define CONFIG_PRAM to hold the number of
3004 kB you want to reserve for pRAM. You can overwrite
3005 this default value by defining an environment
3006 variable "pram" to the number of kB you want to
3007 reserve. Note that the board info structure will
3008 still show the full amount of RAM. If pRAM is
3009 reserved, a new environment variable "mem" will
3010 automatically be defined to hold the amount of
3011 remaining RAM in a form that can be passed as boot
3012 argument to Linux, for instance like that:
3014 setenv bootargs ... mem=\${mem}
3017 This way you can tell Linux not to use this memory,
3018 either, which results in a memory region that will
3019 not be affected by reboots.
3021 *WARNING* If your board configuration uses automatic
3022 detection of the RAM size, you must make sure that
3023 this memory test is non-destructive. So far, the
3024 following board configurations are known to be
3027 IVMS8, IVML24, SPD8xx, TQM8xxL,
3028 HERMES, IP860, RPXlite, LWMON,
3031 - Access to physical memory region (> 4GB)
3032 Some basic support is provided for operations on memory not
3033 normally accessible to U-Boot - e.g. some architectures
3034 support access to more than 4GB of memory on 32-bit
3035 machines using physical address extension or similar.
3036 Define CONFIG_PHYSMEM to access this basic support, which
3037 currently only supports clearing the memory.
3042 Define this variable to stop the system in case of a
3043 fatal error, so that you have to reset it manually.
3044 This is probably NOT a good idea for an embedded
3045 system where you want the system to reboot
3046 automatically as fast as possible, but it may be
3047 useful during development since you can try to debug
3048 the conditions that lead to the situation.
3050 CONFIG_NET_RETRY_COUNT
3052 This variable defines the number of retries for
3053 network operations like ARP, RARP, TFTP, or BOOTP
3054 before giving up the operation. If not defined, a
3055 default value of 5 is used.
3059 Timeout waiting for an ARP reply in milliseconds.
3063 Timeout in milliseconds used in NFS protocol.
3064 If you encounter "ERROR: Cannot umount" in nfs command,
3065 try longer timeout such as
3066 #define CONFIG_NFS_TIMEOUT 10000UL
3068 - Command Interpreter:
3069 CONFIG_AUTO_COMPLETE
3071 Enable auto completion of commands using TAB.
3073 CONFIG_SYS_PROMPT_HUSH_PS2
3075 This defines the secondary prompt string, which is
3076 printed when the command interpreter needs more input
3077 to complete a command. Usually "> ".
3081 In the current implementation, the local variables
3082 space and global environment variables space are
3083 separated. Local variables are those you define by
3084 simply typing `name=value'. To access a local
3085 variable later on, you have write `$name' or
3086 `${name}'; to execute the contents of a variable
3087 directly type `$name' at the command prompt.
3089 Global environment variables are those you use
3090 setenv/printenv to work with. To run a command stored
3091 in such a variable, you need to use the run command,
3092 and you must not use the '$' sign to access them.
3094 To store commands and special characters in a
3095 variable, please use double quotation marks
3096 surrounding the whole text of the variable, instead
3097 of the backslashes before semicolons and special
3100 - Command Line Editing and History:
3101 CONFIG_CMDLINE_EDITING
3103 Enable editing and History functions for interactive
3104 command line input operations
3106 - Default Environment:
3107 CONFIG_EXTRA_ENV_SETTINGS
3109 Define this to contain any number of null terminated
3110 strings (variable = value pairs) that will be part of
3111 the default environment compiled into the boot image.
3113 For example, place something like this in your
3114 board's config file:
3116 #define CONFIG_EXTRA_ENV_SETTINGS \
3120 Warning: This method is based on knowledge about the
3121 internal format how the environment is stored by the
3122 U-Boot code. This is NOT an official, exported
3123 interface! Although it is unlikely that this format
3124 will change soon, there is no guarantee either.
3125 You better know what you are doing here.
3127 Note: overly (ab)use of the default environment is
3128 discouraged. Make sure to check other ways to preset
3129 the environment like the "source" command or the
3132 CONFIG_ENV_VARS_UBOOT_CONFIG
3134 Define this in order to add variables describing the
3135 U-Boot build configuration to the default environment.
3136 These will be named arch, cpu, board, vendor, and soc.
3138 Enabling this option will cause the following to be defined:
3146 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3148 Define this in order to add variables describing certain
3149 run-time determined information about the hardware to the
3150 environment. These will be named board_name, board_rev.
3152 CONFIG_DELAY_ENVIRONMENT
3154 Normally the environment is loaded when the board is
3155 initialised so that it is available to U-Boot. This inhibits
3156 that so that the environment is not available until
3157 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3158 this is instead controlled by the value of
3159 /config/load-environment.
3161 - DataFlash Support:
3162 CONFIG_HAS_DATAFLASH
3164 Defining this option enables DataFlash features and
3165 allows to read/write in Dataflash via the standard
3168 - Serial Flash support
3171 Defining this option enables SPI flash commands
3172 'sf probe/read/write/erase/update'.
3174 Usage requires an initial 'probe' to define the serial
3175 flash parameters, followed by read/write/erase/update
3178 The following defaults may be provided by the platform
3179 to handle the common case when only a single serial
3180 flash is present on the system.
3182 CONFIG_SF_DEFAULT_BUS Bus identifier
3183 CONFIG_SF_DEFAULT_CS Chip-select
3184 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3185 CONFIG_SF_DEFAULT_SPEED in Hz
3189 Define this option to include a destructive SPI flash
3192 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3194 Define this option to use the Bank addr/Extended addr
3195 support on SPI flashes which has size > 16Mbytes.
3197 CONFIG_SF_DUAL_FLASH Dual flash memories
3199 Define this option to use dual flash support where two flash
3200 memories can be connected with a given cs line.
3201 Currently Xilinx Zynq qspi supports these type of connections.
3203 - SystemACE Support:
3206 Adding this option adds support for Xilinx SystemACE
3207 chips attached via some sort of local bus. The address
3208 of the chip must also be defined in the
3209 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3211 #define CONFIG_SYSTEMACE
3212 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3214 When SystemACE support is added, the "ace" device type
3215 becomes available to the fat commands, i.e. fatls.
3217 - TFTP Fixed UDP Port:
3220 If this is defined, the environment variable tftpsrcp
3221 is used to supply the TFTP UDP source port value.
3222 If tftpsrcp isn't defined, the normal pseudo-random port
3223 number generator is used.
3225 Also, the environment variable tftpdstp is used to supply
3226 the TFTP UDP destination port value. If tftpdstp isn't
3227 defined, the normal port 69 is used.
3229 The purpose for tftpsrcp is to allow a TFTP server to
3230 blindly start the TFTP transfer using the pre-configured
3231 target IP address and UDP port. This has the effect of
3232 "punching through" the (Windows XP) firewall, allowing
3233 the remainder of the TFTP transfer to proceed normally.
3234 A better solution is to properly configure the firewall,
3235 but sometimes that is not allowed.
3240 This enables a generic 'hash' command which can produce
3241 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3245 Enable the hash verify command (hash -v). This adds to code
3248 CONFIG_SHA1 - This option enables support of hashing using SHA1
3249 algorithm. The hash is calculated in software.
3250 CONFIG_SHA256 - This option enables support of hashing using
3251 SHA256 algorithm. The hash is calculated in software.
3252 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3253 for SHA1/SHA256 hashing.
3254 This affects the 'hash' command and also the
3255 hash_lookup_algo() function.
3256 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3257 hardware-acceleration for SHA1/SHA256 progressive hashing.
3258 Data can be streamed in a block at a time and the hashing
3259 is performed in hardware.
3261 Note: There is also a sha1sum command, which should perhaps
3262 be deprecated in favour of 'hash sha1'.
3264 - Freescale i.MX specific commands:
3265 CONFIG_CMD_HDMIDETECT
3266 This enables 'hdmidet' command which returns true if an
3267 HDMI monitor is detected. This command is i.MX 6 specific.
3270 This enables the 'bmode' (bootmode) command for forcing
3271 a boot from specific media.
3273 This is useful for forcing the ROM's usb downloader to
3274 activate upon a watchdog reset which is nice when iterating
3275 on U-Boot. Using the reset button or running bmode normal
3276 will set it back to normal. This command currently
3277 supports i.MX53 and i.MX6.
3282 This enables the RSA algorithm used for FIT image verification
3283 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3285 The Modular Exponentiation algorithm in RSA is implemented using
3286 driver model. So CONFIG_DM needs to be enabled by default for this
3287 library to function.
3289 The signing part is build into mkimage regardless of this
3290 option. The software based modular exponentiation is built into
3291 mkimage irrespective of this option.
3293 - bootcount support:
3294 CONFIG_BOOTCOUNT_LIMIT
3296 This enables the bootcounter support, see:
3297 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3300 enable special bootcounter support on at91sam9xe based boards.
3302 enable special bootcounter support on blackfin based boards.
3304 enable special bootcounter support on da850 based boards.
3305 CONFIG_BOOTCOUNT_RAM
3306 enable support for the bootcounter in RAM
3307 CONFIG_BOOTCOUNT_I2C
3308 enable support for the bootcounter on an i2c (like RTC) device.
3309 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3310 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3312 CONFIG_BOOTCOUNT_ALEN = address len
3314 - Show boot progress:
3315 CONFIG_SHOW_BOOT_PROGRESS
3317 Defining this option allows to add some board-
3318 specific code (calling a user-provided function
3319 "show_boot_progress(int)") that enables you to show
3320 the system's boot progress on some display (for
3321 example, some LED's) on your board. At the moment,
3322 the following checkpoints are implemented:
3325 Legacy uImage format:
3328 1 common/cmd_bootm.c before attempting to boot an image
3329 -1 common/cmd_bootm.c Image header has bad magic number
3330 2 common/cmd_bootm.c Image header has correct magic number
3331 -2 common/cmd_bootm.c Image header has bad checksum
3332 3 common/cmd_bootm.c Image header has correct checksum
3333 -3 common/cmd_bootm.c Image data has bad checksum
3334 4 common/cmd_bootm.c Image data has correct checksum
3335 -4 common/cmd_bootm.c Image is for unsupported architecture
3336 5 common/cmd_bootm.c Architecture check OK
3337 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3338 6 common/cmd_bootm.c Image Type check OK
3339 -6 common/cmd_bootm.c gunzip uncompression error
3340 -7 common/cmd_bootm.c Unimplemented compression type
3341 7 common/cmd_bootm.c Uncompression OK
3342 8 common/cmd_bootm.c No uncompress/copy overwrite error
3343 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3345 9 common/image.c Start initial ramdisk verification
3346 -10 common/image.c Ramdisk header has bad magic number
3347 -11 common/image.c Ramdisk header has bad checksum
3348 10 common/image.c Ramdisk header is OK
3349 -12 common/image.c Ramdisk data has bad checksum
3350 11 common/image.c Ramdisk data has correct checksum
3351 12 common/image.c Ramdisk verification complete, start loading
3352 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3353 13 common/image.c Start multifile image verification
3354 14 common/image.c No initial ramdisk, no multifile, continue.
3356 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3358 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3359 -31 post/post.c POST test failed, detected by post_output_backlog()
3360 -32 post/post.c POST test failed, detected by post_run_single()
3362 34 common/cmd_doc.c before loading a Image from a DOC device
3363 -35 common/cmd_doc.c Bad usage of "doc" command
3364 35 common/cmd_doc.c correct usage of "doc" command
3365 -36 common/cmd_doc.c No boot device
3366 36 common/cmd_doc.c correct boot device
3367 -37 common/cmd_doc.c Unknown Chip ID on boot device
3368 37 common/cmd_doc.c correct chip ID found, device available
3369 -38 common/cmd_doc.c Read Error on boot device
3370 38 common/cmd_doc.c reading Image header from DOC device OK
3371 -39 common/cmd_doc.c Image header has bad magic number
3372 39 common/cmd_doc.c Image header has correct magic number
3373 -40 common/cmd_doc.c Error reading Image from DOC device
3374 40 common/cmd_doc.c Image header has correct magic number
3375 41 common/cmd_ide.c before loading a Image from a IDE device
3376 -42 common/cmd_ide.c Bad usage of "ide" command
3377 42 common/cmd_ide.c correct usage of "ide" command
3378 -43 common/cmd_ide.c No boot device
3379 43 common/cmd_ide.c boot device found
3380 -44 common/cmd_ide.c Device not available
3381 44 common/cmd_ide.c Device available
3382 -45 common/cmd_ide.c wrong partition selected
3383 45 common/cmd_ide.c partition selected
3384 -46 common/cmd_ide.c Unknown partition table
3385 46 common/cmd_ide.c valid partition table found
3386 -47 common/cmd_ide.c Invalid partition type
3387 47 common/cmd_ide.c correct partition type
3388 -48 common/cmd_ide.c Error reading Image Header on boot device
3389 48 common/cmd_ide.c reading Image Header from IDE device OK
3390 -49 common/cmd_ide.c Image header has bad magic number
3391 49 common/cmd_ide.c Image header has correct magic number
3392 -50 common/cmd_ide.c Image header has bad checksum
3393 50 common/cmd_ide.c Image header has correct checksum
3394 -51 common/cmd_ide.c Error reading Image from IDE device
3395 51 common/cmd_ide.c reading Image from IDE device OK
3396 52 common/cmd_nand.c before loading a Image from a NAND device
3397 -53 common/cmd_nand.c Bad usage of "nand" command
3398 53 common/cmd_nand.c correct usage of "nand" command
3399 -54 common/cmd_nand.c No boot device
3400 54 common/cmd_nand.c boot device found
3401 -55 common/cmd_nand.c Unknown Chip ID on boot device
3402 55 common/cmd_nand.c correct chip ID found, device available
3403 -56 common/cmd_nand.c Error reading Image Header on boot device
3404 56 common/cmd_nand.c reading Image Header from NAND device OK
3405 -57 common/cmd_nand.c Image header has bad magic number
3406 57 common/cmd_nand.c Image header has correct magic number
3407 -58 common/cmd_nand.c Error reading Image from NAND device
3408 58 common/cmd_nand.c reading Image from NAND device OK
3410 -60 common/env_common.c Environment has a bad CRC, using default
3412 64 net/eth.c starting with Ethernet configuration.
3413 -64 net/eth.c no Ethernet found.
3414 65 net/eth.c Ethernet found.
3416 -80 common/cmd_net.c usage wrong
3417 80 common/cmd_net.c before calling net_loop()
3418 -81 common/cmd_net.c some error in net_loop() occurred
3419 81 common/cmd_net.c net_loop() back without error
3420 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3421 82 common/cmd_net.c trying automatic boot
3422 83 common/cmd_net.c running "source" command
3423 -83 common/cmd_net.c some error in automatic boot or "source" command
3424 84 common/cmd_net.c end without errors
3429 100 common/cmd_bootm.c Kernel FIT Image has correct format
3430 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3431 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3432 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3433 102 common/cmd_bootm.c Kernel unit name specified
3434 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3435 103 common/cmd_bootm.c Found configuration node
3436 104 common/cmd_bootm.c Got kernel subimage node offset
3437 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3438 105 common/cmd_bootm.c Kernel subimage hash verification OK
3439 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3440 106 common/cmd_bootm.c Architecture check OK
3441 -106 common/cmd_bootm.c Kernel subimage has wrong type
3442 107 common/cmd_bootm.c Kernel subimage type OK
3443 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3444 108 common/cmd_bootm.c Got kernel subimage data/size
3445 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3446 -109 common/cmd_bootm.c Can't get kernel subimage type
3447 -110 common/cmd_bootm.c Can't get kernel subimage comp
3448 -111 common/cmd_bootm.c Can't get kernel subimage os
3449 -112 common/cmd_bootm.c Can't get kernel subimage load address
3450 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3452 120 common/image.c Start initial ramdisk verification
3453 -120 common/image.c Ramdisk FIT image has incorrect format
3454 121 common/image.c Ramdisk FIT image has correct format
3455 122 common/image.c No ramdisk subimage unit name, using configuration
3456 -122 common/image.c Can't get configuration for ramdisk subimage
3457 123 common/image.c Ramdisk unit name specified
3458 -124 common/image.c Can't get ramdisk subimage node offset
3459 125 common/image.c Got ramdisk subimage node offset
3460 -125 common/image.c Ramdisk subimage hash verification failed
3461 126 common/image.c Ramdisk subimage hash verification OK
3462 -126 common/image.c Ramdisk subimage for unsupported architecture
3463 127 common/image.c Architecture check OK
3464 -127 common/image.c Can't get ramdisk subimage data/size
3465 128 common/image.c Got ramdisk subimage data/size
3466 129 common/image.c Can't get ramdisk load address
3467 -129 common/image.c Got ramdisk load address
3469 -130 common/cmd_doc.c Incorrect FIT image format
3470 131 common/cmd_doc.c FIT image format OK
3472 -140 common/cmd_ide.c Incorrect FIT image format
3473 141 common/cmd_ide.c FIT image format OK
3475 -150 common/cmd_nand.c Incorrect FIT image format
3476 151 common/cmd_nand.c FIT image format OK
3478 - legacy image format:
3479 CONFIG_IMAGE_FORMAT_LEGACY
3480 enables the legacy image format support in U-Boot.
3483 enabled if CONFIG_FIT_SIGNATURE is not defined.
3485 CONFIG_DISABLE_IMAGE_LEGACY
3486 disable the legacy image format
3488 This define is introduced, as the legacy image format is
3489 enabled per default for backward compatibility.
3491 - FIT image support:
3493 Enable support for the FIT uImage format.
3495 CONFIG_FIT_BEST_MATCH
3496 When no configuration is explicitly selected, default to the
3497 one whose fdt's compatibility field best matches that of
3498 U-Boot itself. A match is considered "best" if it matches the
3499 most specific compatibility entry of U-Boot's fdt's root node.
3500 The order of entries in the configuration's fdt is ignored.
3502 CONFIG_FIT_SIGNATURE
3503 This option enables signature verification of FIT uImages,
3504 using a hash signed and verified using RSA. If
3505 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3506 hashing is available using hardware, RSA library will use it.
3507 See doc/uImage.FIT/signature.txt for more details.
3509 WARNING: When relying on signed FIT images with required
3510 signature check the legacy image format is default
3511 disabled. If a board need legacy image format support
3512 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3514 CONFIG_FIT_DISABLE_SHA256
3515 Supporting SHA256 hashes has quite an impact on binary size.
3516 For constrained systems sha256 hash support can be disabled
3519 - Standalone program support:
3520 CONFIG_STANDALONE_LOAD_ADDR
3522 This option defines a board specific value for the
3523 address where standalone program gets loaded, thus
3524 overwriting the architecture dependent default
3527 - Frame Buffer Address:
3530 Define CONFIG_FB_ADDR if you want to use specific
3531 address for frame buffer. This is typically the case
3532 when using a graphics controller has separate video
3533 memory. U-Boot will then place the frame buffer at
3534 the given address instead of dynamically reserving it
3535 in system RAM by calling lcd_setmem(), which grabs
3536 the memory for the frame buffer depending on the
3537 configured panel size.
3539 Please see board_init_f function.
3541 - Automatic software updates via TFTP server
3543 CONFIG_UPDATE_TFTP_CNT_MAX
3544 CONFIG_UPDATE_TFTP_MSEC_MAX
3546 These options enable and control the auto-update feature;
3547 for a more detailed description refer to doc/README.update.
3549 - MTD Support (mtdparts command, UBI support)
3552 Adds the MTD device infrastructure from the Linux kernel.
3553 Needed for mtdparts command support.
3555 CONFIG_MTD_PARTITIONS
3557 Adds the MTD partitioning infrastructure from the Linux
3558 kernel. Needed for UBI support.
3563 Adds commands for interacting with MTD partitions formatted
3564 with the UBI flash translation layer
3566 Requires also defining CONFIG_RBTREE
3568 CONFIG_UBI_SILENCE_MSG
3570 Make the verbose messages from UBI stop printing. This leaves
3571 warnings and errors enabled.
3574 CONFIG_MTD_UBI_WL_THRESHOLD
3575 This parameter defines the maximum difference between the highest
3576 erase counter value and the lowest erase counter value of eraseblocks
3577 of UBI devices. When this threshold is exceeded, UBI starts performing
3578 wear leveling by means of moving data from eraseblock with low erase
3579 counter to eraseblocks with high erase counter.
3581 The default value should be OK for SLC NAND flashes, NOR flashes and
3582 other flashes which have eraseblock life-cycle 100000 or more.
3583 However, in case of MLC NAND flashes which typically have eraseblock
3584 life-cycle less than 10000, the threshold should be lessened (e.g.,
3585 to 128 or 256, although it does not have to be power of 2).
3589 CONFIG_MTD_UBI_BEB_LIMIT
3590 This option specifies the maximum bad physical eraseblocks UBI
3591 expects on the MTD device (per 1024 eraseblocks). If the
3592 underlying flash does not admit of bad eraseblocks (e.g. NOR
3593 flash), this value is ignored.
3595 NAND datasheets often specify the minimum and maximum NVM
3596 (Number of Valid Blocks) for the flashes' endurance lifetime.
3597 The maximum expected bad eraseblocks per 1024 eraseblocks
3598 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3599 which gives 20 for most NANDs (MaxNVB is basically the total
3600 count of eraseblocks on the chip).
3602 To put it differently, if this value is 20, UBI will try to
3603 reserve about 1.9% of physical eraseblocks for bad blocks
3604 handling. And that will be 1.9% of eraseblocks on the entire
3605 NAND chip, not just the MTD partition UBI attaches. This means
3606 that if you have, say, a NAND flash chip admits maximum 40 bad
3607 eraseblocks, and it is split on two MTD partitions of the same
3608 size, UBI will reserve 40 eraseblocks when attaching a
3613 CONFIG_MTD_UBI_FASTMAP
3614 Fastmap is a mechanism which allows attaching an UBI device
3615 in nearly constant time. Instead of scanning the whole MTD device it
3616 only has to locate a checkpoint (called fastmap) on the device.
3617 The on-flash fastmap contains all information needed to attach
3618 the device. Using fastmap makes only sense on large devices where
3619 attaching by scanning takes long. UBI will not automatically install
3620 a fastmap on old images, but you can set the UBI parameter
3621 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3622 that fastmap-enabled images are still usable with UBI implementations
3623 without fastmap support. On typical flash devices the whole fastmap
3624 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3626 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3627 Set this parameter to enable fastmap automatically on images
3634 Adds commands for interacting with UBI volumes formatted as
3635 UBIFS. UBIFS is read-only in u-boot.
3637 Requires UBI support as well as CONFIG_LZO
3639 CONFIG_UBIFS_SILENCE_MSG
3641 Make the verbose messages from UBIFS stop printing. This leaves
3642 warnings and errors enabled.
3646 Enable building of SPL globally.
3649 LDSCRIPT for linking the SPL binary.
3651 CONFIG_SPL_MAX_FOOTPRINT
3652 Maximum size in memory allocated to the SPL, BSS included.
3653 When defined, the linker checks that the actual memory
3654 used by SPL from _start to __bss_end does not exceed it.
3655 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3656 must not be both defined at the same time.
3659 Maximum size of the SPL image (text, data, rodata, and
3660 linker lists sections), BSS excluded.
3661 When defined, the linker checks that the actual size does
3664 CONFIG_SPL_TEXT_BASE
3665 TEXT_BASE for linking the SPL binary.
3667 CONFIG_SPL_RELOC_TEXT_BASE
3668 Address to relocate to. If unspecified, this is equal to
3669 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3671 CONFIG_SPL_BSS_START_ADDR
3672 Link address for the BSS within the SPL binary.
3674 CONFIG_SPL_BSS_MAX_SIZE
3675 Maximum size in memory allocated to the SPL BSS.
3676 When defined, the linker checks that the actual memory used
3677 by SPL from __bss_start to __bss_end does not exceed it.
3678 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3679 must not be both defined at the same time.
3682 Adress of the start of the stack SPL will use
3684 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3685 When defined, SPL will panic() if the image it has
3686 loaded does not have a signature.
3687 Defining this is useful when code which loads images
3688 in SPL cannot guarantee that absolutely all read errors
3690 An example is the LPC32XX MLC NAND driver, which will
3691 consider that a completely unreadable NAND block is bad,
3692 and thus should be skipped silently.
3694 CONFIG_SPL_RELOC_STACK
3695 Adress of the start of the stack SPL will use after
3696 relocation. If unspecified, this is equal to
3699 CONFIG_SYS_SPL_MALLOC_START
3700 Starting address of the malloc pool used in SPL.
3702 CONFIG_SYS_SPL_MALLOC_SIZE
3703 The size of the malloc pool used in SPL.
3705 CONFIG_SPL_FRAMEWORK
3706 Enable the SPL framework under common/. This framework
3707 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3708 NAND loading of the Linux Kernel.
3711 Enable booting directly to an OS from SPL.
3712 See also: doc/README.falcon
3714 CONFIG_SPL_DISPLAY_PRINT
3715 For ARM, enable an optional function to print more information
3716 about the running system.
3718 CONFIG_SPL_INIT_MINIMAL
3719 Arch init code should be built for a very small image
3721 CONFIG_SPL_LIBCOMMON_SUPPORT
3722 Support for common/libcommon.o in SPL binary
3724 CONFIG_SPL_LIBDISK_SUPPORT
3725 Support for disk/libdisk.o in SPL binary
3727 CONFIG_SPL_I2C_SUPPORT
3728 Support for drivers/i2c/libi2c.o in SPL binary
3730 CONFIG_SPL_GPIO_SUPPORT
3731 Support for drivers/gpio/libgpio.o in SPL binary
3733 CONFIG_SPL_MMC_SUPPORT
3734 Support for drivers/mmc/libmmc.o in SPL binary
3736 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3737 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3738 Address and partition on the MMC to load U-Boot from
3739 when the MMC is being used in raw mode.
3741 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3742 Partition on the MMC to load U-Boot from when the MMC is being
3745 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3746 Sector to load kernel uImage from when MMC is being
3747 used in raw mode (for Falcon mode)
3749 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3750 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3751 Sector and number of sectors to load kernel argument
3752 parameters from when MMC is being used in raw mode
3755 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3756 Partition on the MMC to load U-Boot from when the MMC is being
3759 CONFIG_SPL_FAT_SUPPORT
3760 Support for fs/fat/libfat.o in SPL binary
3762 CONFIG_SPL_EXT_SUPPORT
3763 Support for EXT filesystem in SPL binary
3765 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3766 Filename to read to load U-Boot when reading from filesystem
3768 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3769 Filename to read to load kernel uImage when reading
3770 from filesystem (for Falcon mode)
3772 CONFIG_SPL_FS_LOAD_ARGS_NAME
3773 Filename to read to load kernel argument parameters
3774 when reading from filesystem (for Falcon mode)
3776 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3777 Set this for NAND SPL on PPC mpc83xx targets, so that
3778 start.S waits for the rest of the SPL to load before
3779 continuing (the hardware starts execution after just
3780 loading the first page rather than the full 4K).
3782 CONFIG_SPL_SKIP_RELOCATE
3783 Avoid SPL relocation
3785 CONFIG_SPL_NAND_BASE
3786 Include nand_base.c in the SPL. Requires
3787 CONFIG_SPL_NAND_DRIVERS.
3789 CONFIG_SPL_NAND_DRIVERS
3790 SPL uses normal NAND drivers, not minimal drivers.
3793 Include standard software ECC in the SPL
3795 CONFIG_SPL_NAND_SIMPLE
3796 Support for NAND boot using simple NAND drivers that
3797 expose the cmd_ctrl() interface.
3799 CONFIG_SPL_MTD_SUPPORT
3800 Support for the MTD subsystem within SPL. Useful for
3801 environment on NAND support within SPL.
3803 CONFIG_SPL_NAND_RAW_ONLY
3804 Support to boot only raw u-boot.bin images. Use this only
3805 if you need to save space.
3807 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3808 Set for the SPL on PPC mpc8xxx targets, support for
3809 drivers/ddr/fsl/libddr.o in SPL binary.
3811 CONFIG_SPL_COMMON_INIT_DDR
3812 Set for common ddr init with serial presence detect in
3815 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3816 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3817 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3818 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3819 CONFIG_SYS_NAND_ECCBYTES
3820 Defines the size and behavior of the NAND that SPL uses
3823 CONFIG_SPL_NAND_BOOT
3824 Add support NAND boot
3826 CONFIG_SYS_NAND_U_BOOT_OFFS
3827 Location in NAND to read U-Boot from
3829 CONFIG_SYS_NAND_U_BOOT_DST
3830 Location in memory to load U-Boot to
3832 CONFIG_SYS_NAND_U_BOOT_SIZE
3833 Size of image to load
3835 CONFIG_SYS_NAND_U_BOOT_START
3836 Entry point in loaded image to jump to
3838 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3839 Define this if you need to first read the OOB and then the
3840 data. This is used, for example, on davinci platforms.
3842 CONFIG_SPL_OMAP3_ID_NAND
3843 Support for an OMAP3-specific set of functions to return the
3844 ID and MFR of the first attached NAND chip, if present.
3846 CONFIG_SPL_SERIAL_SUPPORT
3847 Support for drivers/serial/libserial.o in SPL binary
3849 CONFIG_SPL_SPI_FLASH_SUPPORT
3850 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3852 CONFIG_SPL_SPI_SUPPORT
3853 Support for drivers/spi/libspi.o in SPL binary
3855 CONFIG_SPL_RAM_DEVICE
3856 Support for running image already present in ram, in SPL binary
3858 CONFIG_SPL_LIBGENERIC_SUPPORT
3859 Support for lib/libgeneric.o in SPL binary
3861 CONFIG_SPL_ENV_SUPPORT
3862 Support for the environment operating in SPL binary
3864 CONFIG_SPL_NET_SUPPORT
3865 Support for the net/libnet.o in SPL binary.
3866 It conflicts with SPL env from storage medium specified by
3867 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3870 Image offset to which the SPL should be padded before appending
3871 the SPL payload. By default, this is defined as
3872 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3873 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3874 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3877 Final target image containing SPL and payload. Some SPLs
3878 use an arch-specific makefile fragment instead, for
3879 example if more than one image needs to be produced.
3881 CONFIG_FIT_SPL_PRINT
3882 Printing information about a FIT image adds quite a bit of
3883 code to SPL. So this is normally disabled in SPL. Use this
3884 option to re-enable it. This will affect the output of the
3885 bootm command when booting a FIT image.
3889 Enable building of TPL globally.
3892 Image offset to which the TPL should be padded before appending
3893 the TPL payload. By default, this is defined as
3894 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3895 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3896 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3901 [so far only for SMDK2400 boards]
3903 - Modem support enable:
3904 CONFIG_MODEM_SUPPORT
3906 - RTS/CTS Flow control enable:
3909 - Modem debug support:
3910 CONFIG_MODEM_SUPPORT_DEBUG
3912 Enables debugging stuff (char screen[1024], dbg())
3913 for modem support. Useful only with BDI2000.
3915 - Interrupt support (PPC):
3917 There are common interrupt_init() and timer_interrupt()
3918 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3919 for CPU specific initialization. interrupt_init_cpu()
3920 should set decrementer_count to appropriate value. If
3921 CPU resets decrementer automatically after interrupt
3922 (ppc4xx) it should set decrementer_count to zero.
3923 timer_interrupt() calls timer_interrupt_cpu() for CPU
3924 specific handling. If board has watchdog / status_led
3925 / other_activity_monitor it works automatically from
3926 general timer_interrupt().
3930 In the target system modem support is enabled when a
3931 specific key (key combination) is pressed during
3932 power-on. Otherwise U-Boot will boot normally
3933 (autoboot). The key_pressed() function is called from
3934 board_init(). Currently key_pressed() is a dummy
3935 function, returning 1 and thus enabling modem
3938 If there are no modem init strings in the
3939 environment, U-Boot proceed to autoboot; the
3940 previous output (banner, info printfs) will be
3943 See also: doc/README.Modem
3945 Board initialization settings:
3946 ------------------------------
3948 During Initialization u-boot calls a number of board specific functions
3949 to allow the preparation of board specific prerequisites, e.g. pin setup
3950 before drivers are initialized. To enable these callbacks the
3951 following configuration macros have to be defined. Currently this is
3952 architecture specific, so please check arch/your_architecture/lib/board.c
3953 typically in board_init_f() and board_init_r().
3955 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3956 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3957 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3958 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3960 Configuration Settings:
3961 -----------------------
3963 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3964 Optionally it can be defined to support 64-bit memory commands.
3966 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3967 undefine this when you're short of memory.
3969 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3970 width of the commands listed in the 'help' command output.
3972 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3973 prompt for user input.
3975 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3977 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3979 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3981 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3982 the application (usually a Linux kernel) when it is
3985 - CONFIG_SYS_BAUDRATE_TABLE:
3986 List of legal baudrate settings for this board.
3988 - CONFIG_SYS_CONSOLE_INFO_QUIET
3989 Suppress display of console information at boot.
3991 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3992 If the board specific function
3993 extern int overwrite_console (void);
3994 returns 1, the stdin, stderr and stdout are switched to the
3995 serial port, else the settings in the environment are used.
3997 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3998 Enable the call to overwrite_console().
4000 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4001 Enable overwrite of previous console environment settings.
4003 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4004 Begin and End addresses of the area used by the
4007 - CONFIG_SYS_ALT_MEMTEST:
4008 Enable an alternate, more extensive memory test.
4010 - CONFIG_SYS_MEMTEST_SCRATCH:
4011 Scratch address used by the alternate memory test
4012 You only need to set this if address zero isn't writeable
4014 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4015 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4016 this specified memory area will get subtracted from the top
4017 (end) of RAM and won't get "touched" at all by U-Boot. By
4018 fixing up gd->ram_size the Linux kernel should gets passed
4019 the now "corrected" memory size and won't touch it either.
4020 This should work for arch/ppc and arch/powerpc. Only Linux
4021 board ports in arch/powerpc with bootwrapper support that
4022 recalculate the memory size from the SDRAM controller setup
4023 will have to get fixed in Linux additionally.
4025 This option can be used as a workaround for the 440EPx/GRx
4026 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4029 WARNING: Please make sure that this value is a multiple of
4030 the Linux page size (normally 4k). If this is not the case,
4031 then the end address of the Linux memory will be located at a
4032 non page size aligned address and this could cause major
4035 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4036 Enable temporary baudrate change while serial download
4038 - CONFIG_SYS_SDRAM_BASE:
4039 Physical start address of SDRAM. _Must_ be 0 here.
4041 - CONFIG_SYS_MBIO_BASE:
4042 Physical start address of Motherboard I/O (if using a
4045 - CONFIG_SYS_FLASH_BASE:
4046 Physical start address of Flash memory.
4048 - CONFIG_SYS_MONITOR_BASE:
4049 Physical start address of boot monitor code (set by
4050 make config files to be same as the text base address
4051 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4052 CONFIG_SYS_FLASH_BASE when booting from flash.
4054 - CONFIG_SYS_MONITOR_LEN:
4055 Size of memory reserved for monitor code, used to
4056 determine _at_compile_time_ (!) if the environment is
4057 embedded within the U-Boot image, or in a separate
4060 - CONFIG_SYS_MALLOC_LEN:
4061 Size of DRAM reserved for malloc() use.
4063 - CONFIG_SYS_MALLOC_F_LEN
4064 Size of the malloc() pool for use before relocation. If
4065 this is defined, then a very simple malloc() implementation
4066 will become available before relocation. The address is just
4067 below the global data, and the stack is moved down to make
4070 This feature allocates regions with increasing addresses
4071 within the region. calloc() is supported, but realloc()
4072 is not available. free() is supported but does nothing.
4073 The memory will be freed (or in fact just forgotten) when
4074 U-Boot relocates itself.
4076 Pre-relocation malloc() is only supported on ARM and sandbox
4077 at present but is fairly easy to enable for other archs.
4079 - CONFIG_SYS_MALLOC_SIMPLE
4080 Provides a simple and small malloc() and calloc() for those
4081 boards which do not use the full malloc in SPL (which is
4082 enabled with CONFIG_SYS_SPL_MALLOC_START).
4084 - CONFIG_SYS_NONCACHED_MEMORY:
4085 Size of non-cached memory area. This area of memory will be
4086 typically located right below the malloc() area and mapped
4087 uncached in the MMU. This is useful for drivers that would
4088 otherwise require a lot of explicit cache maintenance. For
4089 some drivers it's also impossible to properly maintain the
4090 cache. For example if the regions that need to be flushed
4091 are not a multiple of the cache-line size, *and* padding
4092 cannot be allocated between the regions to align them (i.e.
4093 if the HW requires a contiguous array of regions, and the
4094 size of each region is not cache-aligned), then a flush of
4095 one region may result in overwriting data that hardware has
4096 written to another region in the same cache-line. This can
4097 happen for example in network drivers where descriptors for
4098 buffers are typically smaller than the CPU cache-line (e.g.
4099 16 bytes vs. 32 or 64 bytes).
4101 Non-cached memory is only supported on 32-bit ARM at present.
4103 - CONFIG_SYS_BOOTM_LEN:
4104 Normally compressed uImages are limited to an
4105 uncompressed size of 8 MBytes. If this is not enough,
4106 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4107 to adjust this setting to your needs.
4109 - CONFIG_SYS_BOOTMAPSZ:
4110 Maximum size of memory mapped by the startup code of
4111 the Linux kernel; all data that must be processed by
4112 the Linux kernel (bd_info, boot arguments, FDT blob if
4113 used) must be put below this limit, unless "bootm_low"
4114 environment variable is defined and non-zero. In such case
4115 all data for the Linux kernel must be between "bootm_low"
4116 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4117 variable "bootm_mapsize" will override the value of
4118 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4119 then the value in "bootm_size" will be used instead.
4121 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4122 Enable initrd_high functionality. If defined then the
4123 initrd_high feature is enabled and the bootm ramdisk subcommand
4126 - CONFIG_SYS_BOOT_GET_CMDLINE:
4127 Enables allocating and saving kernel cmdline in space between
4128 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4130 - CONFIG_SYS_BOOT_GET_KBD:
4131 Enables allocating and saving a kernel copy of the bd_info in
4132 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4134 - CONFIG_SYS_MAX_FLASH_BANKS:
4135 Max number of Flash memory banks
4137 - CONFIG_SYS_MAX_FLASH_SECT:
4138 Max number of sectors on a Flash chip
4140 - CONFIG_SYS_FLASH_ERASE_TOUT:
4141 Timeout for Flash erase operations (in ms)
4143 - CONFIG_SYS_FLASH_WRITE_TOUT:
4144 Timeout for Flash write operations (in ms)
4146 - CONFIG_SYS_FLASH_LOCK_TOUT
4147 Timeout for Flash set sector lock bit operation (in ms)
4149 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4150 Timeout for Flash clear lock bits operation (in ms)
4152 - CONFIG_SYS_FLASH_PROTECTION
4153 If defined, hardware flash sectors protection is used
4154 instead of U-Boot software protection.
4156 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4158 Enable TFTP transfers directly to flash memory;
4159 without this option such a download has to be
4160 performed in two steps: (1) download to RAM, and (2)
4161 copy from RAM to flash.
4163 The two-step approach is usually more reliable, since
4164 you can check if the download worked before you erase
4165 the flash, but in some situations (when system RAM is
4166 too limited to allow for a temporary copy of the
4167 downloaded image) this option may be very useful.
4169 - CONFIG_SYS_FLASH_CFI:
4170 Define if the flash driver uses extra elements in the
4171 common flash structure for storing flash geometry.
4173 - CONFIG_FLASH_CFI_DRIVER
4174 This option also enables the building of the cfi_flash driver
4175 in the drivers directory
4177 - CONFIG_FLASH_CFI_MTD
4178 This option enables the building of the cfi_mtd driver
4179 in the drivers directory. The driver exports CFI flash
4182 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4183 Use buffered writes to flash.
4185 - CONFIG_FLASH_SPANSION_S29WS_N
4186 s29ws-n MirrorBit flash has non-standard addresses for buffered
4189 - CONFIG_SYS_FLASH_QUIET_TEST
4190 If this option is defined, the common CFI flash doesn't
4191 print it's warning upon not recognized FLASH banks. This
4192 is useful, if some of the configured banks are only
4193 optionally available.
4195 - CONFIG_FLASH_SHOW_PROGRESS
4196 If defined (must be an integer), print out countdown
4197 digits and dots. Recommended value: 45 (9..1) for 80
4198 column displays, 15 (3..1) for 40 column displays.
4200 - CONFIG_FLASH_VERIFY
4201 If defined, the content of the flash (destination) is compared
4202 against the source after the write operation. An error message
4203 will be printed when the contents are not identical.
4204 Please note that this option is useless in nearly all cases,
4205 since such flash programming errors usually are detected earlier
4206 while unprotecting/erasing/programming. Please only enable
4207 this option if you really know what you are doing.
4209 - CONFIG_SYS_RX_ETH_BUFFER:
4210 Defines the number of Ethernet receive buffers. On some
4211 Ethernet controllers it is recommended to set this value
4212 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4213 buffers can be full shortly after enabling the interface
4214 on high Ethernet traffic.
4215 Defaults to 4 if not defined.
4217 - CONFIG_ENV_MAX_ENTRIES
4219 Maximum number of entries in the hash table that is used
4220 internally to store the environment settings. The default
4221 setting is supposed to be generous and should work in most
4222 cases. This setting can be used to tune behaviour; see
4223 lib/hashtable.c for details.
4225 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4226 - CONFIG_ENV_FLAGS_LIST_STATIC
4227 Enable validation of the values given to environment variables when
4228 calling env set. Variables can be restricted to only decimal,
4229 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4230 the variables can also be restricted to IP address or MAC address.
4232 The format of the list is:
4233 type_attribute = [s|d|x|b|i|m]
4234 access_attribute = [a|r|o|c]
4235 attributes = type_attribute[access_attribute]
4236 entry = variable_name[:attributes]
4239 The type attributes are:
4240 s - String (default)
4243 b - Boolean ([1yYtT|0nNfF])
4247 The access attributes are:
4253 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4254 Define this to a list (string) to define the ".flags"
4255 environment variable in the default or embedded environment.
4257 - CONFIG_ENV_FLAGS_LIST_STATIC
4258 Define this to a list (string) to define validation that
4259 should be done if an entry is not found in the ".flags"
4260 environment variable. To override a setting in the static
4261 list, simply add an entry for the same variable name to the
4264 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4265 regular expression. This allows multiple variables to define the same
4266 flags without explicitly listing them for each variable.
4268 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4269 If defined, don't allow the -f switch to env set override variable
4272 - CONFIG_SYS_GENERIC_BOARD
4273 This selects the architecture-generic board system instead of the
4274 architecture-specific board files. It is intended to move boards
4275 to this new framework over time. Defining this will disable the
4276 arch/foo/lib/board.c file and use common/board_f.c and
4277 common/board_r.c instead. To use this option your architecture
4278 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4279 If you find problems enabling this option on your board please report
4280 the problem and send patches!
4282 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4283 This is set by OMAP boards for the max time that reset should
4284 be asserted. See doc/README.omap-reset-time for details on how
4285 the value can be calculated on a given board.
4288 If stdint.h is available with your toolchain you can define this
4289 option to enable it. You can provide option 'USE_STDINT=1' when
4290 building U-Boot to enable this.
4292 The following definitions that deal with the placement and management
4293 of environment data (variable area); in general, we support the
4294 following configurations:
4296 - CONFIG_BUILD_ENVCRC:
4298 Builds up envcrc with the target environment so that external utils
4299 may easily extract it and embed it in final U-Boot images.
4301 - CONFIG_ENV_IS_IN_FLASH:
4303 Define this if the environment is in flash memory.
4305 a) The environment occupies one whole flash sector, which is
4306 "embedded" in the text segment with the U-Boot code. This
4307 happens usually with "bottom boot sector" or "top boot
4308 sector" type flash chips, which have several smaller
4309 sectors at the start or the end. For instance, such a
4310 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4311 such a case you would place the environment in one of the
4312 4 kB sectors - with U-Boot code before and after it. With
4313 "top boot sector" type flash chips, you would put the
4314 environment in one of the last sectors, leaving a gap
4315 between U-Boot and the environment.
4317 - CONFIG_ENV_OFFSET:
4319 Offset of environment data (variable area) to the
4320 beginning of flash memory; for instance, with bottom boot
4321 type flash chips the second sector can be used: the offset
4322 for this sector is given here.
4324 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4328 This is just another way to specify the start address of
4329 the flash sector containing the environment (instead of
4332 - CONFIG_ENV_SECT_SIZE:
4334 Size of the sector containing the environment.
4337 b) Sometimes flash chips have few, equal sized, BIG sectors.
4338 In such a case you don't want to spend a whole sector for
4343 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4344 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4345 of this flash sector for the environment. This saves
4346 memory for the RAM copy of the environment.
4348 It may also save flash memory if you decide to use this
4349 when your environment is "embedded" within U-Boot code,
4350 since then the remainder of the flash sector could be used
4351 for U-Boot code. It should be pointed out that this is
4352 STRONGLY DISCOURAGED from a robustness point of view:
4353 updating the environment in flash makes it always
4354 necessary to erase the WHOLE sector. If something goes
4355 wrong before the contents has been restored from a copy in
4356 RAM, your target system will be dead.
4358 - CONFIG_ENV_ADDR_REDUND
4359 CONFIG_ENV_SIZE_REDUND
4361 These settings describe a second storage area used to hold
4362 a redundant copy of the environment data, so that there is
4363 a valid backup copy in case there is a power failure during
4364 a "saveenv" operation.
4366 BE CAREFUL! Any changes to the flash layout, and some changes to the
4367 source code will make it necessary to adapt <board>/u-boot.lds*
4371 - CONFIG_ENV_IS_IN_NVRAM:
4373 Define this if you have some non-volatile memory device
4374 (NVRAM, battery buffered SRAM) which you want to use for the
4380 These two #defines are used to determine the memory area you
4381 want to use for environment. It is assumed that this memory
4382 can just be read and written to, without any special
4385 BE CAREFUL! The first access to the environment happens quite early
4386 in U-Boot initialization (when we try to get the setting of for the
4387 console baudrate). You *MUST* have mapped your NVRAM area then, or
4390 Please note that even with NVRAM we still use a copy of the
4391 environment in RAM: we could work on NVRAM directly, but we want to
4392 keep settings there always unmodified except somebody uses "saveenv"
4393 to save the current settings.
4396 - CONFIG_ENV_IS_IN_EEPROM:
4398 Use this if you have an EEPROM or similar serial access
4399 device and a driver for it.
4401 - CONFIG_ENV_OFFSET:
4404 These two #defines specify the offset and size of the
4405 environment area within the total memory of your EEPROM.
4407 - CONFIG_SYS_I2C_EEPROM_ADDR:
4408 If defined, specified the chip address of the EEPROM device.
4409 The default address is zero.
4411 - CONFIG_SYS_I2C_EEPROM_BUS:
4412 If defined, specified the i2c bus of the EEPROM device.
4414 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4415 If defined, the number of bits used to address bytes in a
4416 single page in the EEPROM device. A 64 byte page, for example
4417 would require six bits.
4419 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4420 If defined, the number of milliseconds to delay between
4421 page writes. The default is zero milliseconds.
4423 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4424 The length in bytes of the EEPROM memory array address. Note
4425 that this is NOT the chip address length!
4427 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4428 EEPROM chips that implement "address overflow" are ones
4429 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4430 address and the extra bits end up in the "chip address" bit
4431 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4434 Note that we consider the length of the address field to
4435 still be one byte because the extra address bits are hidden
4436 in the chip address.
4438 - CONFIG_SYS_EEPROM_SIZE:
4439 The size in bytes of the EEPROM device.
4441 - CONFIG_ENV_EEPROM_IS_ON_I2C
4442 define this, if you have I2C and SPI activated, and your
4443 EEPROM, which holds the environment, is on the I2C bus.
4445 - CONFIG_I2C_ENV_EEPROM_BUS
4446 if you have an Environment on an EEPROM reached over
4447 I2C muxes, you can define here, how to reach this
4448 EEPROM. For example:
4450 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4452 EEPROM which holds the environment, is reached over
4453 a pca9547 i2c mux with address 0x70, channel 3.
4455 - CONFIG_ENV_IS_IN_DATAFLASH:
4457 Define this if you have a DataFlash memory device which you
4458 want to use for the environment.
4460 - CONFIG_ENV_OFFSET:
4464 These three #defines specify the offset and size of the
4465 environment area within the total memory of your DataFlash placed
4466 at the specified address.
4468 - CONFIG_ENV_IS_IN_SPI_FLASH:
4470 Define this if you have a SPI Flash memory device which you
4471 want to use for the environment.
4473 - CONFIG_ENV_OFFSET:
4476 These two #defines specify the offset and size of the
4477 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4478 aligned to an erase sector boundary.
4480 - CONFIG_ENV_SECT_SIZE:
4482 Define the SPI flash's sector size.
4484 - CONFIG_ENV_OFFSET_REDUND (optional):
4486 This setting describes a second storage area of CONFIG_ENV_SIZE
4487 size used to hold a redundant copy of the environment data, so
4488 that there is a valid backup copy in case there is a power failure
4489 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4490 aligned to an erase sector boundary.
4492 - CONFIG_ENV_SPI_BUS (optional):
4493 - CONFIG_ENV_SPI_CS (optional):
4495 Define the SPI bus and chip select. If not defined they will be 0.
4497 - CONFIG_ENV_SPI_MAX_HZ (optional):
4499 Define the SPI max work clock. If not defined then use 1MHz.
4501 - CONFIG_ENV_SPI_MODE (optional):
4503 Define the SPI work mode. If not defined then use SPI_MODE_3.
4505 - CONFIG_ENV_IS_IN_REMOTE:
4507 Define this if you have a remote memory space which you
4508 want to use for the local device's environment.
4513 These two #defines specify the address and size of the
4514 environment area within the remote memory space. The
4515 local device can get the environment from remote memory
4516 space by SRIO or PCIE links.
4518 BE CAREFUL! For some special cases, the local device can not use
4519 "saveenv" command. For example, the local device will get the
4520 environment stored in a remote NOR flash by SRIO or PCIE link,
4521 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4523 - CONFIG_ENV_IS_IN_NAND:
4525 Define this if you have a NAND device which you want to use
4526 for the environment.
4528 - CONFIG_ENV_OFFSET:
4531 These two #defines specify the offset and size of the environment
4532 area within the first NAND device. CONFIG_ENV_OFFSET must be
4533 aligned to an erase block boundary.
4535 - CONFIG_ENV_OFFSET_REDUND (optional):
4537 This setting describes a second storage area of CONFIG_ENV_SIZE
4538 size used to hold a redundant copy of the environment data, so
4539 that there is a valid backup copy in case there is a power failure
4540 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4541 aligned to an erase block boundary.
4543 - CONFIG_ENV_RANGE (optional):
4545 Specifies the length of the region in which the environment
4546 can be written. This should be a multiple of the NAND device's
4547 block size. Specifying a range with more erase blocks than
4548 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4549 the range to be avoided.
4551 - CONFIG_ENV_OFFSET_OOB (optional):
4553 Enables support for dynamically retrieving the offset of the
4554 environment from block zero's out-of-band data. The
4555 "nand env.oob" command can be used to record this offset.
4556 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4557 using CONFIG_ENV_OFFSET_OOB.
4559 - CONFIG_NAND_ENV_DST
4561 Defines address in RAM to which the nand_spl code should copy the
4562 environment. If redundant environment is used, it will be copied to
4563 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4565 - CONFIG_ENV_IS_IN_UBI:
4567 Define this if you have an UBI volume that you want to use for the
4568 environment. This has the benefit of wear-leveling the environment
4569 accesses, which is important on NAND.
4571 - CONFIG_ENV_UBI_PART:
4573 Define this to a string that is the mtd partition containing the UBI.
4575 - CONFIG_ENV_UBI_VOLUME:
4577 Define this to the name of the volume that you want to store the
4580 - CONFIG_ENV_UBI_VOLUME_REDUND:
4582 Define this to the name of another volume to store a second copy of
4583 the environment in. This will enable redundant environments in UBI.
4584 It is assumed that both volumes are in the same MTD partition.
4586 - CONFIG_UBI_SILENCE_MSG
4587 - CONFIG_UBIFS_SILENCE_MSG
4589 You will probably want to define these to avoid a really noisy system
4590 when storing the env in UBI.
4592 - CONFIG_ENV_IS_IN_FAT:
4593 Define this if you want to use the FAT file system for the environment.
4595 - FAT_ENV_INTERFACE:
4597 Define this to a string that is the name of the block device.
4599 - FAT_ENV_DEV_AND_PART:
4601 Define this to a string to specify the partition of the device. It can
4604 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4605 - "D:P": device D partition P. Error occurs if device D has no
4608 - "D" or "D:": device D partition 1 if device D has partition
4609 table, or the whole device D if has no partition
4611 - "D:auto": first partition in device D with bootable flag set.
4612 If none, first valid partition in device D. If no
4613 partition table then means device D.
4617 It's a string of the FAT file name. This file use to store the
4621 This should be defined. Otherwise it cannot save the environment file.
4623 - CONFIG_ENV_IS_IN_MMC:
4625 Define this if you have an MMC device which you want to use for the
4628 - CONFIG_SYS_MMC_ENV_DEV:
4630 Specifies which MMC device the environment is stored in.
4632 - CONFIG_SYS_MMC_ENV_PART (optional):
4634 Specifies which MMC partition the environment is stored in. If not
4635 set, defaults to partition 0, the user area. Common values might be
4636 1 (first MMC boot partition), 2 (second MMC boot partition).
4638 - CONFIG_ENV_OFFSET:
4641 These two #defines specify the offset and size of the environment
4642 area within the specified MMC device.
4644 If offset is positive (the usual case), it is treated as relative to
4645 the start of the MMC partition. If offset is negative, it is treated
4646 as relative to the end of the MMC partition. This can be useful if
4647 your board may be fitted with different MMC devices, which have
4648 different sizes for the MMC partitions, and you always want the
4649 environment placed at the very end of the partition, to leave the
4650 maximum possible space before it, to store other data.
4652 These two values are in units of bytes, but must be aligned to an
4653 MMC sector boundary.
4655 - CONFIG_ENV_OFFSET_REDUND (optional):
4657 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4658 hold a redundant copy of the environment data. This provides a
4659 valid backup copy in case the other copy is corrupted, e.g. due
4660 to a power failure during a "saveenv" operation.
4662 This value may also be positive or negative; this is handled in the
4663 same way as CONFIG_ENV_OFFSET.
4665 This value is also in units of bytes, but must also be aligned to
4666 an MMC sector boundary.
4668 - CONFIG_ENV_SIZE_REDUND (optional):
4670 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4671 set. If this value is set, it must be set to the same value as
4674 - CONFIG_SYS_SPI_INIT_OFFSET
4676 Defines offset to the initial SPI buffer area in DPRAM. The
4677 area is used at an early stage (ROM part) if the environment
4678 is configured to reside in the SPI EEPROM: We need a 520 byte
4679 scratch DPRAM area. It is used between the two initialization
4680 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4681 to be a good choice since it makes it far enough from the
4682 start of the data area as well as from the stack pointer.
4684 Please note that the environment is read-only until the monitor
4685 has been relocated to RAM and a RAM copy of the environment has been
4686 created; also, when using EEPROM you will have to use getenv_f()
4687 until then to read environment variables.
4689 The environment is protected by a CRC32 checksum. Before the monitor
4690 is relocated into RAM, as a result of a bad CRC you will be working
4691 with the compiled-in default environment - *silently*!!! [This is
4692 necessary, because the first environment variable we need is the
4693 "baudrate" setting for the console - if we have a bad CRC, we don't
4694 have any device yet where we could complain.]
4696 Note: once the monitor has been relocated, then it will complain if
4697 the default environment is used; a new CRC is computed as soon as you
4698 use the "saveenv" command to store a valid environment.
4700 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4701 Echo the inverted Ethernet link state to the fault LED.
4703 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4704 also needs to be defined.
4706 - CONFIG_SYS_FAULT_MII_ADDR:
4707 MII address of the PHY to check for the Ethernet link state.
4709 - CONFIG_NS16550_MIN_FUNCTIONS:
4710 Define this if you desire to only have use of the NS16550_init
4711 and NS16550_putc functions for the serial driver located at
4712 drivers/serial/ns16550.c. This option is useful for saving
4713 space for already greatly restricted images, including but not
4714 limited to NAND_SPL configurations.
4716 - CONFIG_DISPLAY_BOARDINFO
4717 Display information about the board that U-Boot is running on
4718 when U-Boot starts up. The board function checkboard() is called
4721 - CONFIG_DISPLAY_BOARDINFO_LATE
4722 Similar to the previous option, but display this information
4723 later, once stdio is running and output goes to the LCD, if
4726 - CONFIG_BOARD_SIZE_LIMIT:
4727 Maximum size of the U-Boot image. When defined, the
4728 build system checks that the actual size does not
4731 Low Level (hardware related) configuration options:
4732 ---------------------------------------------------
4734 - CONFIG_SYS_CACHELINE_SIZE:
4735 Cache Line Size of the CPU.
4737 - CONFIG_SYS_DEFAULT_IMMR:
4738 Default address of the IMMR after system reset.
4740 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4741 and RPXsuper) to be able to adjust the position of
4742 the IMMR register after a reset.
4744 - CONFIG_SYS_CCSRBAR_DEFAULT:
4745 Default (power-on reset) physical address of CCSR on Freescale
4748 - CONFIG_SYS_CCSRBAR:
4749 Virtual address of CCSR. On a 32-bit build, this is typically
4750 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4752 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4753 for cross-platform code that uses that macro instead.
4755 - CONFIG_SYS_CCSRBAR_PHYS:
4756 Physical address of CCSR. CCSR can be relocated to a new
4757 physical address, if desired. In this case, this macro should
4758 be set to that address. Otherwise, it should be set to the
4759 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4760 is typically relocated on 36-bit builds. It is recommended
4761 that this macro be defined via the _HIGH and _LOW macros:
4763 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4764 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4766 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4767 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4768 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4769 used in assembly code, so it must not contain typecasts or
4770 integer size suffixes (e.g. "ULL").
4772 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4773 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4774 used in assembly code, so it must not contain typecasts or
4775 integer size suffixes (e.g. "ULL").
4777 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4778 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4779 forced to a value that ensures that CCSR is not relocated.
4781 - Floppy Disk Support:
4782 CONFIG_SYS_FDC_DRIVE_NUMBER
4784 the default drive number (default value 0)
4786 CONFIG_SYS_ISA_IO_STRIDE
4788 defines the spacing between FDC chipset registers
4791 CONFIG_SYS_ISA_IO_OFFSET
4793 defines the offset of register from address. It
4794 depends on which part of the data bus is connected to
4795 the FDC chipset. (default value 0)
4797 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4798 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4801 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4802 fdc_hw_init() is called at the beginning of the FDC
4803 setup. fdc_hw_init() must be provided by the board
4804 source code. It is used to make hardware-dependent
4808 Most IDE controllers were designed to be connected with PCI
4809 interface. Only few of them were designed for AHB interface.
4810 When software is doing ATA command and data transfer to
4811 IDE devices through IDE-AHB controller, some additional
4812 registers accessing to these kind of IDE-AHB controller
4815 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4816 DO NOT CHANGE unless you know exactly what you're
4817 doing! (11-4) [MPC8xx/82xx systems only]
4819 - CONFIG_SYS_INIT_RAM_ADDR:
4821 Start address of memory area that can be used for
4822 initial data and stack; please note that this must be
4823 writable memory that is working WITHOUT special
4824 initialization, i. e. you CANNOT use normal RAM which
4825 will become available only after programming the
4826 memory controller and running certain initialization
4829 U-Boot uses the following memory types:
4830 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4831 - MPC824X: data cache
4832 - PPC4xx: data cache
4834 - CONFIG_SYS_GBL_DATA_OFFSET:
4836 Offset of the initial data structure in the memory
4837 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4838 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4839 data is located at the end of the available space
4840 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4841 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4842 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4843 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4846 On the MPC824X (or other systems that use the data
4847 cache for initial memory) the address chosen for
4848 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4849 point to an otherwise UNUSED address space between
4850 the top of RAM and the start of the PCI space.
4852 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4854 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4856 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4858 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4860 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4862 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4864 - CONFIG_SYS_OR_TIMING_SDRAM:
4867 - CONFIG_SYS_MAMR_PTA:
4868 periodic timer for refresh
4870 - CONFIG_SYS_DER: Debug Event Register (37-47)
4872 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4873 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4874 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4875 CONFIG_SYS_BR1_PRELIM:
4876 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4878 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4879 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4880 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4881 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4883 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4884 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4885 Machine Mode Register and Memory Periodic Timer
4886 Prescaler definitions (SDRAM timing)
4888 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4889 enable I2C microcode relocation patch (MPC8xx);
4890 define relocation offset in DPRAM [DSP2]
4892 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4893 enable SMC microcode relocation patch (MPC8xx);
4894 define relocation offset in DPRAM [SMC1]
4896 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4897 enable SPI microcode relocation patch (MPC8xx);
4898 define relocation offset in DPRAM [SCC4]
4900 - CONFIG_SYS_USE_OSCCLK:
4901 Use OSCM clock mode on MBX8xx board. Be careful,
4902 wrong setting might damage your board. Read
4903 doc/README.MBX before setting this variable!
4905 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4906 Offset of the bootmode word in DPRAM used by post
4907 (Power On Self Tests). This definition overrides
4908 #define'd default value in commproc.h resp.
4911 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4912 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4913 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4914 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4915 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4916 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4917 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4918 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4919 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4921 - CONFIG_PCI_DISABLE_PCIE:
4922 Disable PCI-Express on systems where it is supported but not
4925 - CONFIG_PCI_ENUM_ONLY
4926 Only scan through and get the devices on the buses.
4927 Don't do any setup work, presumably because someone or
4928 something has already done it, and we don't need to do it
4929 a second time. Useful for platforms that are pre-booted
4930 by coreboot or similar.
4932 - CONFIG_PCI_INDIRECT_BRIDGE:
4933 Enable support for indirect PCI bridges.
4936 Chip has SRIO or not
4939 Board has SRIO 1 port available
4942 Board has SRIO 2 port available
4944 - CONFIG_SRIO_PCIE_BOOT_MASTER
4945 Board can support master function for Boot from SRIO and PCIE
4947 - CONFIG_SYS_SRIOn_MEM_VIRT:
4948 Virtual Address of SRIO port 'n' memory region
4950 - CONFIG_SYS_SRIOn_MEM_PHYS:
4951 Physical Address of SRIO port 'n' memory region
4953 - CONFIG_SYS_SRIOn_MEM_SIZE:
4954 Size of SRIO port 'n' memory region
4956 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4957 Defined to tell the NAND controller that the NAND chip is using
4959 Not all NAND drivers use this symbol.
4960 Example of drivers that use it:
4961 - drivers/mtd/nand/ndfc.c
4962 - drivers/mtd/nand/mxc_nand.c
4964 - CONFIG_SYS_NDFC_EBC0_CFG
4965 Sets the EBC0_CFG register for the NDFC. If not defined
4966 a default value will be used.
4969 Get DDR timing information from an I2C EEPROM. Common
4970 with pluggable memory modules such as SODIMMs
4973 I2C address of the SPD EEPROM
4975 - CONFIG_SYS_SPD_BUS_NUM
4976 If SPD EEPROM is on an I2C bus other than the first
4977 one, specify here. Note that the value must resolve
4978 to something your driver can deal with.
4980 - CONFIG_SYS_DDR_RAW_TIMING
4981 Get DDR timing information from other than SPD. Common with
4982 soldered DDR chips onboard without SPD. DDR raw timing
4983 parameters are extracted from datasheet and hard-coded into
4984 header files or board specific files.
4986 - CONFIG_FSL_DDR_INTERACTIVE
4987 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4989 - CONFIG_FSL_DDR_SYNC_REFRESH
4990 Enable sync of refresh for multiple controllers.
4992 - CONFIG_FSL_DDR_BIST
4993 Enable built-in memory test for Freescale DDR controllers.
4995 - CONFIG_SYS_83XX_DDR_USES_CS0
4996 Only for 83xx systems. If specified, then DDR should
4997 be configured using CS0 and CS1 instead of CS2 and CS3.
4999 - CONFIG_ETHER_ON_FEC[12]
5000 Define to enable FEC[12] on a 8xx series processor.
5002 - CONFIG_FEC[12]_PHY
5003 Define to the hardcoded PHY address which corresponds
5004 to the given FEC; i. e.
5005 #define CONFIG_FEC1_PHY 4
5006 means that the PHY with address 4 is connected to FEC1
5008 When set to -1, means to probe for first available.
5010 - CONFIG_FEC[12]_PHY_NORXERR
5011 The PHY does not have a RXERR line (RMII only).
5012 (so program the FEC to ignore it).
5015 Enable RMII mode for all FECs.
5016 Note that this is a global option, we can't
5017 have one FEC in standard MII mode and another in RMII mode.
5019 - CONFIG_CRC32_VERIFY
5020 Add a verify option to the crc32 command.
5023 => crc32 -v <address> <count> <crc32>
5025 Where address/count indicate a memory area
5026 and crc32 is the correct crc32 which the
5030 Add the "loopw" memory command. This only takes effect if
5031 the memory commands are activated globally (CONFIG_CMD_MEM).
5034 Add the "mdc" and "mwc" memory commands. These are cyclic
5039 This command will print 4 bytes (10,11,12,13) each 500 ms.
5041 => mwc.l 100 12345678 10
5042 This command will write 12345678 to address 100 all 10 ms.
5044 This only takes effect if the memory commands are activated
5045 globally (CONFIG_CMD_MEM).
5047 - CONFIG_SKIP_LOWLEVEL_INIT
5048 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5049 low level initializations (like setting up the memory
5050 controller) are omitted and/or U-Boot does not
5051 relocate itself into RAM.
5053 Normally this variable MUST NOT be defined. The only
5054 exception is when U-Boot is loaded (to RAM) by some
5055 other boot loader or by a debugger which performs
5056 these initializations itself.
5059 Modifies the behaviour of start.S when compiling a loader
5060 that is executed before the actual U-Boot. E.g. when
5061 compiling a NAND SPL.
5064 Modifies the behaviour of start.S when compiling a loader
5065 that is executed after the SPL and before the actual U-Boot.
5066 It is loaded by the SPL.
5068 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5069 Only for 85xx systems. If this variable is specified, the section
5070 .resetvec is not kept and the section .bootpg is placed in the
5071 previous 4k of the .text section.
5073 - CONFIG_ARCH_MAP_SYSMEM
5074 Generally U-Boot (and in particular the md command) uses
5075 effective address. It is therefore not necessary to regard
5076 U-Boot address as virtual addresses that need to be translated
5077 to physical addresses. However, sandbox requires this, since
5078 it maintains its own little RAM buffer which contains all
5079 addressable memory. This option causes some memory accesses
5080 to be mapped through map_sysmem() / unmap_sysmem().
5082 - CONFIG_USE_ARCH_MEMCPY
5083 CONFIG_USE_ARCH_MEMSET
5084 If these options are used a optimized version of memcpy/memset will
5085 be used if available. These functions may be faster under some
5086 conditions but may increase the binary size.
5088 - CONFIG_X86_RESET_VECTOR
5089 If defined, the x86 reset vector code is included. This is not
5090 needed when U-Boot is running from Coreboot.
5093 Defines the MPU clock speed (in MHz).
5095 NOTE : currently only supported on AM335x platforms.
5097 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5098 Enables the RTC32K OSC on AM33xx based plattforms
5100 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5101 Option to disable subpage write in NAND driver
5102 driver that uses this:
5103 drivers/mtd/nand/davinci_nand.c
5105 Freescale QE/FMAN Firmware Support:
5106 -----------------------------------
5108 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5109 loading of "firmware", which is encoded in the QE firmware binary format.
5110 This firmware often needs to be loaded during U-Boot booting, so macros
5111 are used to identify the storage device (NOR flash, SPI, etc) and the address
5114 - CONFIG_SYS_FMAN_FW_ADDR
5115 The address in the storage device where the FMAN microcode is located. The
5116 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5119 - CONFIG_SYS_QE_FW_ADDR
5120 The address in the storage device where the QE microcode is located. The
5121 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5124 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5125 The maximum possible size of the firmware. The firmware binary format
5126 has a field that specifies the actual size of the firmware, but it
5127 might not be possible to read any part of the firmware unless some
5128 local storage is allocated to hold the entire firmware first.
5130 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5131 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5132 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5133 virtual address in NOR flash.
5135 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5136 Specifies that QE/FMAN firmware is located in NAND flash.
5137 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5139 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5140 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5141 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5143 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5144 Specifies that QE/FMAN firmware is located on the primary SPI
5145 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5147 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5148 Specifies that QE/FMAN firmware is located in the remote (master)
5149 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5150 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5151 window->master inbound window->master LAW->the ucode address in
5152 master's memory space.
5154 Freescale Layerscape Management Complex Firmware Support:
5155 ---------------------------------------------------------
5156 The Freescale Layerscape Management Complex (MC) supports the loading of
5158 This firmware often needs to be loaded during U-Boot booting, so macros
5159 are used to identify the storage device (NOR flash, SPI, etc) and the address
5162 - CONFIG_FSL_MC_ENET
5163 Enable the MC driver for Layerscape SoCs.
5165 - CONFIG_SYS_LS_MC_FW_ADDR
5166 The address in the storage device where the firmware is located. The
5167 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5170 - CONFIG_SYS_LS_MC_FW_LENGTH
5171 The maximum possible size of the firmware. The firmware binary format
5172 has a field that specifies the actual size of the firmware, but it
5173 might not be possible to read any part of the firmware unless some
5174 local storage is allocated to hold the entire firmware first.
5176 - CONFIG_SYS_LS_MC_FW_IN_NOR
5177 Specifies that MC firmware is located in NOR flash, mapped as
5178 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5179 virtual address in NOR flash.
5181 Building the Software:
5182 ======================
5184 Building U-Boot has been tested in several native build environments
5185 and in many different cross environments. Of course we cannot support
5186 all possibly existing versions of cross development tools in all
5187 (potentially obsolete) versions. In case of tool chain problems we
5188 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5189 which is extensively used to build and test U-Boot.
5191 If you are not using a native environment, it is assumed that you
5192 have GNU cross compiling tools available in your path. In this case,
5193 you must set the environment variable CROSS_COMPILE in your shell.
5194 Note that no changes to the Makefile or any other source files are
5195 necessary. For example using the ELDK on a 4xx CPU, please enter:
5197 $ CROSS_COMPILE=ppc_4xx-
5198 $ export CROSS_COMPILE
5200 Note: If you wish to generate Windows versions of the utilities in
5201 the tools directory you can use the MinGW toolchain
5202 (http://www.mingw.org). Set your HOST tools to the MinGW
5203 toolchain and execute 'make tools'. For example:
5205 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5207 Binaries such as tools/mkimage.exe will be created which can
5208 be executed on computers running Windows.
5210 U-Boot is intended to be simple to build. After installing the
5211 sources you must configure U-Boot for one specific board type. This
5216 where "NAME_defconfig" is the name of one of the existing configu-
5217 rations; see boards.cfg for supported names.
5219 Note: for some board special configuration names may exist; check if
5220 additional information is available from the board vendor; for
5221 instance, the TQM823L systems are available without (standard)
5222 or with LCD support. You can select such additional "features"
5223 when choosing the configuration, i. e.
5225 make TQM823L_defconfig
5226 - will configure for a plain TQM823L, i. e. no LCD support
5228 make TQM823L_LCD_defconfig
5229 - will configure for a TQM823L with U-Boot console on LCD
5234 Finally, type "make all", and you should get some working U-Boot
5235 images ready for download to / installation on your system:
5237 - "u-boot.bin" is a raw binary image
5238 - "u-boot" is an image in ELF binary format
5239 - "u-boot.srec" is in Motorola S-Record format
5241 By default the build is performed locally and the objects are saved
5242 in the source directory. One of the two methods can be used to change
5243 this behavior and build U-Boot to some external directory:
5245 1. Add O= to the make command line invocations:
5247 make O=/tmp/build distclean
5248 make O=/tmp/build NAME_defconfig
5249 make O=/tmp/build all
5251 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5253 export KBUILD_OUTPUT=/tmp/build
5258 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5262 Please be aware that the Makefiles assume you are using GNU make, so
5263 for instance on NetBSD you might need to use "gmake" instead of
5267 If the system board that you have is not listed, then you will need
5268 to port U-Boot to your hardware platform. To do this, follow these
5271 1. Add a new configuration option for your board to the toplevel
5272 "boards.cfg" file, using the existing entries as examples.
5273 Follow the instructions there to keep the boards in order.
5274 2. Create a new directory to hold your board specific code. Add any
5275 files you need. In your board directory, you will need at least
5276 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5277 3. Create a new configuration file "include/configs/<board>.h" for
5279 3. If you're porting U-Boot to a new CPU, then also create a new
5280 directory to hold your CPU specific code. Add any files you need.
5281 4. Run "make <board>_defconfig" with your new name.
5282 5. Type "make", and you should get a working "u-boot.srec" file
5283 to be installed on your target system.
5284 6. Debug and solve any problems that might arise.
5285 [Of course, this last step is much harder than it sounds.]
5288 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5289 ==============================================================
5291 If you have modified U-Boot sources (for instance added a new board
5292 or support for new devices, a new CPU, etc.) you are expected to
5293 provide feedback to the other developers. The feedback normally takes
5294 the form of a "patch", i. e. a context diff against a certain (latest
5295 official or latest in the git repository) version of U-Boot sources.
5297 But before you submit such a patch, please verify that your modifi-
5298 cation did not break existing code. At least make sure that *ALL* of
5299 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5300 just run the "MAKEALL" script, which will configure and build U-Boot
5301 for ALL supported system. Be warned, this will take a while. You can
5302 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5303 environment variable to the script, i. e. to use the ELDK cross tools
5306 CROSS_COMPILE=ppc_8xx- MAKEALL
5308 or to build on a native PowerPC system you can type
5310 CROSS_COMPILE=' ' MAKEALL
5312 When using the MAKEALL script, the default behaviour is to build
5313 U-Boot in the source directory. This location can be changed by
5314 setting the BUILD_DIR environment variable. Also, for each target
5315 built, the MAKEALL script saves two log files (<target>.ERR and
5316 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5317 location can be changed by setting the MAKEALL_LOGDIR environment
5318 variable. For example:
5320 export BUILD_DIR=/tmp/build
5321 export MAKEALL_LOGDIR=/tmp/log
5322 CROSS_COMPILE=ppc_8xx- MAKEALL
5324 With the above settings build objects are saved in the /tmp/build,
5325 log files are saved in the /tmp/log and the source tree remains clean
5326 during the whole build process.
5329 See also "U-Boot Porting Guide" below.
5332 Monitor Commands - Overview:
5333 ============================
5335 go - start application at address 'addr'
5336 run - run commands in an environment variable
5337 bootm - boot application image from memory
5338 bootp - boot image via network using BootP/TFTP protocol
5339 bootz - boot zImage from memory
5340 tftpboot- boot image via network using TFTP protocol
5341 and env variables "ipaddr" and "serverip"
5342 (and eventually "gatewayip")
5343 tftpput - upload a file via network using TFTP protocol
5344 rarpboot- boot image via network using RARP/TFTP protocol
5345 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5346 loads - load S-Record file over serial line
5347 loadb - load binary file over serial line (kermit mode)
5349 mm - memory modify (auto-incrementing)
5350 nm - memory modify (constant address)
5351 mw - memory write (fill)
5353 cmp - memory compare
5354 crc32 - checksum calculation
5355 i2c - I2C sub-system
5356 sspi - SPI utility commands
5357 base - print or set address offset
5358 printenv- print environment variables
5359 setenv - set environment variables
5360 saveenv - save environment variables to persistent storage
5361 protect - enable or disable FLASH write protection
5362 erase - erase FLASH memory
5363 flinfo - print FLASH memory information
5364 nand - NAND memory operations (see doc/README.nand)
5365 bdinfo - print Board Info structure
5366 iminfo - print header information for application image
5367 coninfo - print console devices and informations
5368 ide - IDE sub-system
5369 loop - infinite loop on address range
5370 loopw - infinite write loop on address range
5371 mtest - simple RAM test
5372 icache - enable or disable instruction cache
5373 dcache - enable or disable data cache
5374 reset - Perform RESET of the CPU
5375 echo - echo args to console
5376 version - print monitor version
5377 help - print online help
5378 ? - alias for 'help'
5381 Monitor Commands - Detailed Description:
5382 ========================================
5386 For now: just type "help <command>".
5389 Environment Variables:
5390 ======================
5392 U-Boot supports user configuration using Environment Variables which
5393 can be made persistent by saving to Flash memory.
5395 Environment Variables are set using "setenv", printed using
5396 "printenv", and saved to Flash using "saveenv". Using "setenv"
5397 without a value can be used to delete a variable from the
5398 environment. As long as you don't save the environment you are
5399 working with an in-memory copy. In case the Flash area containing the
5400 environment is erased by accident, a default environment is provided.
5402 Some configuration options can be set using Environment Variables.
5404 List of environment variables (most likely not complete):
5406 baudrate - see CONFIG_BAUDRATE
5408 bootdelay - see CONFIG_BOOTDELAY
5410 bootcmd - see CONFIG_BOOTCOMMAND
5412 bootargs - Boot arguments when booting an RTOS image
5414 bootfile - Name of the image to load with TFTP
5416 bootm_low - Memory range available for image processing in the bootm
5417 command can be restricted. This variable is given as
5418 a hexadecimal number and defines lowest address allowed
5419 for use by the bootm command. See also "bootm_size"
5420 environment variable. Address defined by "bootm_low" is
5421 also the base of the initial memory mapping for the Linux
5422 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5425 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5426 This variable is given as a hexadecimal number and it
5427 defines the size of the memory region starting at base
5428 address bootm_low that is accessible by the Linux kernel
5429 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5430 as the default value if it is defined, and bootm_size is
5433 bootm_size - Memory range available for image processing in the bootm
5434 command can be restricted. This variable is given as
5435 a hexadecimal number and defines the size of the region
5436 allowed for use by the bootm command. See also "bootm_low"
5437 environment variable.
5439 updatefile - Location of the software update file on a TFTP server, used
5440 by the automatic software update feature. Please refer to
5441 documentation in doc/README.update for more details.
5443 autoload - if set to "no" (any string beginning with 'n'),
5444 "bootp" will just load perform a lookup of the
5445 configuration from the BOOTP server, but not try to
5446 load any image using TFTP
5448 autostart - if set to "yes", an image loaded using the "bootp",
5449 "rarpboot", "tftpboot" or "diskboot" commands will
5450 be automatically started (by internally calling
5453 If set to "no", a standalone image passed to the
5454 "bootm" command will be copied to the load address
5455 (and eventually uncompressed), but NOT be started.
5456 This can be used to load and uncompress arbitrary
5459 fdt_high - if set this restricts the maximum address that the
5460 flattened device tree will be copied into upon boot.
5461 For example, if you have a system with 1 GB memory
5462 at physical address 0x10000000, while Linux kernel
5463 only recognizes the first 704 MB as low memory, you
5464 may need to set fdt_high as 0x3C000000 to have the
5465 device tree blob be copied to the maximum address
5466 of the 704 MB low memory, so that Linux kernel can
5467 access it during the boot procedure.
5469 If this is set to the special value 0xFFFFFFFF then
5470 the fdt will not be copied at all on boot. For this
5471 to work it must reside in writable memory, have
5472 sufficient padding on the end of it for u-boot to
5473 add the information it needs into it, and the memory
5474 must be accessible by the kernel.
5476 fdtcontroladdr- if set this is the address of the control flattened
5477 device tree used by U-Boot when CONFIG_OF_CONTROL is
5480 i2cfast - (PPC405GP|PPC405EP only)
5481 if set to 'y' configures Linux I2C driver for fast
5482 mode (400kHZ). This environment variable is used in
5483 initialization code. So, for changes to be effective
5484 it must be saved and board must be reset.
5486 initrd_high - restrict positioning of initrd images:
5487 If this variable is not set, initrd images will be
5488 copied to the highest possible address in RAM; this
5489 is usually what you want since it allows for
5490 maximum initrd size. If for some reason you want to
5491 make sure that the initrd image is loaded below the
5492 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5493 variable to a value of "no" or "off" or "0".
5494 Alternatively, you can set it to a maximum upper
5495 address to use (U-Boot will still check that it
5496 does not overwrite the U-Boot stack and data).
5498 For instance, when you have a system with 16 MB
5499 RAM, and want to reserve 4 MB from use by Linux,
5500 you can do this by adding "mem=12M" to the value of
5501 the "bootargs" variable. However, now you must make
5502 sure that the initrd image is placed in the first
5503 12 MB as well - this can be done with
5505 setenv initrd_high 00c00000
5507 If you set initrd_high to 0xFFFFFFFF, this is an
5508 indication to U-Boot that all addresses are legal
5509 for the Linux kernel, including addresses in flash
5510 memory. In this case U-Boot will NOT COPY the
5511 ramdisk at all. This may be useful to reduce the
5512 boot time on your system, but requires that this
5513 feature is supported by your Linux kernel.
5515 ipaddr - IP address; needed for tftpboot command
5517 loadaddr - Default load address for commands like "bootp",
5518 "rarpboot", "tftpboot", "loadb" or "diskboot"
5520 loads_echo - see CONFIG_LOADS_ECHO
5522 serverip - TFTP server IP address; needed for tftpboot command
5524 bootretry - see CONFIG_BOOT_RETRY_TIME
5526 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5528 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5530 ethprime - controls which interface is used first.
5532 ethact - controls which interface is currently active.
5533 For example you can do the following
5535 => setenv ethact FEC
5536 => ping 192.168.0.1 # traffic sent on FEC
5537 => setenv ethact SCC
5538 => ping 10.0.0.1 # traffic sent on SCC
5540 ethrotate - When set to "no" U-Boot does not go through all
5541 available network interfaces.
5542 It just stays at the currently selected interface.
5544 netretry - When set to "no" each network operation will
5545 either succeed or fail without retrying.
5546 When set to "once" the network operation will
5547 fail when all the available network interfaces
5548 are tried once without success.
5549 Useful on scripts which control the retry operation
5552 npe_ucode - set load address for the NPE microcode
5554 silent_linux - If set then Linux will be told to boot silently, by
5555 changing the console to be empty. If "yes" it will be
5556 made silent. If "no" it will not be made silent. If
5557 unset, then it will be made silent if the U-Boot console
5560 tftpsrcport - If this is set, the value is used for TFTP's
5563 tftpdstport - If this is set, the value is used for TFTP's UDP
5564 destination port instead of the Well Know Port 69.
5566 tftpblocksize - Block size to use for TFTP transfers; if not set,
5567 we use the TFTP server's default block size
5569 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5570 seconds, minimum value is 1000 = 1 second). Defines
5571 when a packet is considered to be lost so it has to
5572 be retransmitted. The default is 5000 = 5 seconds.
5573 Lowering this value may make downloads succeed
5574 faster in networks with high packet loss rates or
5575 with unreliable TFTP servers.
5577 vlan - When set to a value < 4095 the traffic over
5578 Ethernet is encapsulated/received over 802.1q
5581 The following image location variables contain the location of images
5582 used in booting. The "Image" column gives the role of the image and is
5583 not an environment variable name. The other columns are environment
5584 variable names. "File Name" gives the name of the file on a TFTP
5585 server, "RAM Address" gives the location in RAM the image will be
5586 loaded to, and "Flash Location" gives the image's address in NOR
5587 flash or offset in NAND flash.
5589 *Note* - these variables don't have to be defined for all boards, some
5590 boards currently use other variables for these purposes, and some
5591 boards use these variables for other purposes.
5593 Image File Name RAM Address Flash Location
5594 ----- --------- ----------- --------------
5595 u-boot u-boot u-boot_addr_r u-boot_addr
5596 Linux kernel bootfile kernel_addr_r kernel_addr
5597 device tree blob fdtfile fdt_addr_r fdt_addr
5598 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5600 The following environment variables may be used and automatically
5601 updated by the network boot commands ("bootp" and "rarpboot"),
5602 depending the information provided by your boot server:
5604 bootfile - see above
5605 dnsip - IP address of your Domain Name Server
5606 dnsip2 - IP address of your secondary Domain Name Server
5607 gatewayip - IP address of the Gateway (Router) to use
5608 hostname - Target hostname
5610 netmask - Subnet Mask
5611 rootpath - Pathname of the root filesystem on the NFS server
5612 serverip - see above
5615 There are two special Environment Variables:
5617 serial# - contains hardware identification information such
5618 as type string and/or serial number
5619 ethaddr - Ethernet address
5621 These variables can be set only once (usually during manufacturing of
5622 the board). U-Boot refuses to delete or overwrite these variables
5623 once they have been set once.
5626 Further special Environment Variables:
5628 ver - Contains the U-Boot version string as printed
5629 with the "version" command. This variable is
5630 readonly (see CONFIG_VERSION_VARIABLE).
5633 Please note that changes to some configuration parameters may take
5634 only effect after the next boot (yes, that's just like Windoze :-).
5637 Callback functions for environment variables:
5638 ---------------------------------------------
5640 For some environment variables, the behavior of u-boot needs to change
5641 when their values are changed. This functionality allows functions to
5642 be associated with arbitrary variables. On creation, overwrite, or
5643 deletion, the callback will provide the opportunity for some side
5644 effect to happen or for the change to be rejected.
5646 The callbacks are named and associated with a function using the
5647 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5649 These callbacks are associated with variables in one of two ways. The
5650 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5651 in the board configuration to a string that defines a list of
5652 associations. The list must be in the following format:
5654 entry = variable_name[:callback_name]
5657 If the callback name is not specified, then the callback is deleted.
5658 Spaces are also allowed anywhere in the list.
5660 Callbacks can also be associated by defining the ".callbacks" variable
5661 with the same list format above. Any association in ".callbacks" will
5662 override any association in the static list. You can define
5663 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5664 ".callbacks" environment variable in the default or embedded environment.
5666 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5667 regular expression. This allows multiple variables to be connected to
5668 the same callback without explicitly listing them all out.
5671 Command Line Parsing:
5672 =====================
5674 There are two different command line parsers available with U-Boot:
5675 the old "simple" one, and the much more powerful "hush" shell:
5677 Old, simple command line parser:
5678 --------------------------------
5680 - supports environment variables (through setenv / saveenv commands)
5681 - several commands on one line, separated by ';'
5682 - variable substitution using "... ${name} ..." syntax
5683 - special characters ('$', ';') can be escaped by prefixing with '\',
5685 setenv bootcmd bootm \${address}
5686 - You can also escape text by enclosing in single apostrophes, for example:
5687 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5692 - similar to Bourne shell, with control structures like
5693 if...then...else...fi, for...do...done; while...do...done,
5694 until...do...done, ...
5695 - supports environment ("global") variables (through setenv / saveenv
5696 commands) and local shell variables (through standard shell syntax
5697 "name=value"); only environment variables can be used with "run"
5703 (1) If a command line (or an environment variable executed by a "run"
5704 command) contains several commands separated by semicolon, and
5705 one of these commands fails, then the remaining commands will be
5708 (2) If you execute several variables with one call to run (i. e.
5709 calling run with a list of variables as arguments), any failing
5710 command will cause "run" to terminate, i. e. the remaining
5711 variables are not executed.
5713 Note for Redundant Ethernet Interfaces:
5714 =======================================
5716 Some boards come with redundant Ethernet interfaces; U-Boot supports
5717 such configurations and is capable of automatic selection of a
5718 "working" interface when needed. MAC assignment works as follows:
5720 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5721 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5722 "eth1addr" (=>eth1), "eth2addr", ...
5724 If the network interface stores some valid MAC address (for instance
5725 in SROM), this is used as default address if there is NO correspon-
5726 ding setting in the environment; if the corresponding environment
5727 variable is set, this overrides the settings in the card; that means:
5729 o If the SROM has a valid MAC address, and there is no address in the
5730 environment, the SROM's address is used.
5732 o If there is no valid address in the SROM, and a definition in the
5733 environment exists, then the value from the environment variable is
5736 o If both the SROM and the environment contain a MAC address, and
5737 both addresses are the same, this MAC address is used.
5739 o If both the SROM and the environment contain a MAC address, and the
5740 addresses differ, the value from the environment is used and a
5743 o If neither SROM nor the environment contain a MAC address, an error
5744 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5745 a random, locally-assigned MAC is used.
5747 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5748 will be programmed into hardware as part of the initialization process. This
5749 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5750 The naming convention is as follows:
5751 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5756 U-Boot is capable of booting (and performing other auxiliary operations on)
5757 images in two formats:
5759 New uImage format (FIT)
5760 -----------------------
5762 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5763 to Flattened Device Tree). It allows the use of images with multiple
5764 components (several kernels, ramdisks, etc.), with contents protected by
5765 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5771 Old image format is based on binary files which can be basically anything,
5772 preceded by a special header; see the definitions in include/image.h for
5773 details; basically, the header defines the following image properties:
5775 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5776 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5777 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5778 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5780 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5781 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5782 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5783 * Compression Type (uncompressed, gzip, bzip2)
5789 The header is marked by a special Magic Number, and both the header
5790 and the data portions of the image are secured against corruption by
5797 Although U-Boot should support any OS or standalone application
5798 easily, the main focus has always been on Linux during the design of
5801 U-Boot includes many features that so far have been part of some
5802 special "boot loader" code within the Linux kernel. Also, any
5803 "initrd" images to be used are no longer part of one big Linux image;
5804 instead, kernel and "initrd" are separate images. This implementation
5805 serves several purposes:
5807 - the same features can be used for other OS or standalone
5808 applications (for instance: using compressed images to reduce the
5809 Flash memory footprint)
5811 - it becomes much easier to port new Linux kernel versions because
5812 lots of low-level, hardware dependent stuff are done by U-Boot
5814 - the same Linux kernel image can now be used with different "initrd"
5815 images; of course this also means that different kernel images can
5816 be run with the same "initrd". This makes testing easier (you don't
5817 have to build a new "zImage.initrd" Linux image when you just
5818 change a file in your "initrd"). Also, a field-upgrade of the
5819 software is easier now.
5825 Porting Linux to U-Boot based systems:
5826 ---------------------------------------
5828 U-Boot cannot save you from doing all the necessary modifications to
5829 configure the Linux device drivers for use with your target hardware
5830 (no, we don't intend to provide a full virtual machine interface to
5833 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5835 Just make sure your machine specific header file (for instance
5836 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5837 Information structure as we define in include/asm-<arch>/u-boot.h,
5838 and make sure that your definition of IMAP_ADDR uses the same value
5839 as your U-Boot configuration in CONFIG_SYS_IMMR.
5841 Note that U-Boot now has a driver model, a unified model for drivers.
5842 If you are adding a new driver, plumb it into driver model. If there
5843 is no uclass available, you are encouraged to create one. See
5847 Configuring the Linux kernel:
5848 -----------------------------
5850 No specific requirements for U-Boot. Make sure you have some root
5851 device (initial ramdisk, NFS) for your target system.
5854 Building a Linux Image:
5855 -----------------------
5857 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5858 not used. If you use recent kernel source, a new build target
5859 "uImage" will exist which automatically builds an image usable by
5860 U-Boot. Most older kernels also have support for a "pImage" target,
5861 which was introduced for our predecessor project PPCBoot and uses a
5862 100% compatible format.
5866 make TQM850L_defconfig
5871 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5872 encapsulate a compressed Linux kernel image with header information,
5873 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5875 * build a standard "vmlinux" kernel image (in ELF binary format):
5877 * convert the kernel into a raw binary image:
5879 ${CROSS_COMPILE}-objcopy -O binary \
5880 -R .note -R .comment \
5881 -S vmlinux linux.bin
5883 * compress the binary image:
5887 * package compressed binary image for U-Boot:
5889 mkimage -A ppc -O linux -T kernel -C gzip \
5890 -a 0 -e 0 -n "Linux Kernel Image" \
5891 -d linux.bin.gz uImage
5894 The "mkimage" tool can also be used to create ramdisk images for use
5895 with U-Boot, either separated from the Linux kernel image, or
5896 combined into one file. "mkimage" encapsulates the images with a 64
5897 byte header containing information about target architecture,
5898 operating system, image type, compression method, entry points, time
5899 stamp, CRC32 checksums, etc.
5901 "mkimage" can be called in two ways: to verify existing images and
5902 print the header information, or to build new images.
5904 In the first form (with "-l" option) mkimage lists the information
5905 contained in the header of an existing U-Boot image; this includes
5906 checksum verification:
5908 tools/mkimage -l image
5909 -l ==> list image header information
5911 The second form (with "-d" option) is used to build a U-Boot image
5912 from a "data file" which is used as image payload:
5914 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5915 -n name -d data_file image
5916 -A ==> set architecture to 'arch'
5917 -O ==> set operating system to 'os'
5918 -T ==> set image type to 'type'
5919 -C ==> set compression type 'comp'
5920 -a ==> set load address to 'addr' (hex)
5921 -e ==> set entry point to 'ep' (hex)
5922 -n ==> set image name to 'name'
5923 -d ==> use image data from 'datafile'
5925 Right now, all Linux kernels for PowerPC systems use the same load
5926 address (0x00000000), but the entry point address depends on the
5929 - 2.2.x kernels have the entry point at 0x0000000C,
5930 - 2.3.x and later kernels have the entry point at 0x00000000.
5932 So a typical call to build a U-Boot image would read:
5934 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5935 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5936 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5937 > examples/uImage.TQM850L
5938 Image Name: 2.4.4 kernel for TQM850L
5939 Created: Wed Jul 19 02:34:59 2000
5940 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5941 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5942 Load Address: 0x00000000
5943 Entry Point: 0x00000000
5945 To verify the contents of the image (or check for corruption):
5947 -> tools/mkimage -l examples/uImage.TQM850L
5948 Image Name: 2.4.4 kernel for TQM850L
5949 Created: Wed Jul 19 02:34:59 2000
5950 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5951 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5952 Load Address: 0x00000000
5953 Entry Point: 0x00000000
5955 NOTE: for embedded systems where boot time is critical you can trade
5956 speed for memory and install an UNCOMPRESSED image instead: this
5957 needs more space in Flash, but boots much faster since it does not
5958 need to be uncompressed:
5960 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5961 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5962 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5963 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5964 > examples/uImage.TQM850L-uncompressed
5965 Image Name: 2.4.4 kernel for TQM850L
5966 Created: Wed Jul 19 02:34:59 2000
5967 Image Type: PowerPC Linux Kernel Image (uncompressed)
5968 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5969 Load Address: 0x00000000
5970 Entry Point: 0x00000000
5973 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5974 when your kernel is intended to use an initial ramdisk:
5976 -> tools/mkimage -n 'Simple Ramdisk Image' \
5977 > -A ppc -O linux -T ramdisk -C gzip \
5978 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5979 Image Name: Simple Ramdisk Image
5980 Created: Wed Jan 12 14:01:50 2000
5981 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5982 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5983 Load Address: 0x00000000
5984 Entry Point: 0x00000000
5986 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5987 option performs the converse operation of the mkimage's second form (the "-d"
5988 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5991 tools/dumpimage -i image -T type -p position data_file
5992 -i ==> extract from the 'image' a specific 'data_file'
5993 -T ==> set image type to 'type'
5994 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5997 Installing a Linux Image:
5998 -------------------------
6000 To downloading a U-Boot image over the serial (console) interface,
6001 you must convert the image to S-Record format:
6003 objcopy -I binary -O srec examples/image examples/image.srec
6005 The 'objcopy' does not understand the information in the U-Boot
6006 image header, so the resulting S-Record file will be relative to
6007 address 0x00000000. To load it to a given address, you need to
6008 specify the target address as 'offset' parameter with the 'loads'
6011 Example: install the image to address 0x40100000 (which on the
6012 TQM8xxL is in the first Flash bank):
6014 => erase 40100000 401FFFFF
6020 ## Ready for S-Record download ...
6021 ~>examples/image.srec
6022 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6024 15989 15990 15991 15992
6025 [file transfer complete]
6027 ## Start Addr = 0x00000000
6030 You can check the success of the download using the 'iminfo' command;
6031 this includes a checksum verification so you can be sure no data
6032 corruption happened:
6036 ## Checking Image at 40100000 ...
6037 Image Name: 2.2.13 for initrd on TQM850L
6038 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6039 Data Size: 335725 Bytes = 327 kB = 0 MB
6040 Load Address: 00000000
6041 Entry Point: 0000000c
6042 Verifying Checksum ... OK
6048 The "bootm" command is used to boot an application that is stored in
6049 memory (RAM or Flash). In case of a Linux kernel image, the contents
6050 of the "bootargs" environment variable is passed to the kernel as
6051 parameters. You can check and modify this variable using the
6052 "printenv" and "setenv" commands:
6055 => printenv bootargs
6056 bootargs=root=/dev/ram
6058 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6060 => printenv bootargs
6061 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6064 ## Booting Linux kernel at 40020000 ...
6065 Image Name: 2.2.13 for NFS on TQM850L
6066 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6067 Data Size: 381681 Bytes = 372 kB = 0 MB
6068 Load Address: 00000000
6069 Entry Point: 0000000c
6070 Verifying Checksum ... OK
6071 Uncompressing Kernel Image ... OK
6072 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
6073 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6074 time_init: decrementer frequency = 187500000/60
6075 Calibrating delay loop... 49.77 BogoMIPS
6076 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6079 If you want to boot a Linux kernel with initial RAM disk, you pass
6080 the memory addresses of both the kernel and the initrd image (PPBCOOT
6081 format!) to the "bootm" command:
6083 => imi 40100000 40200000
6085 ## Checking Image at 40100000 ...
6086 Image Name: 2.2.13 for initrd on TQM850L
6087 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6088 Data Size: 335725 Bytes = 327 kB = 0 MB
6089 Load Address: 00000000
6090 Entry Point: 0000000c
6091 Verifying Checksum ... OK
6093 ## Checking Image at 40200000 ...
6094 Image Name: Simple Ramdisk Image
6095 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6096 Data Size: 566530 Bytes = 553 kB = 0 MB
6097 Load Address: 00000000
6098 Entry Point: 00000000
6099 Verifying Checksum ... OK
6101 => bootm 40100000 40200000
6102 ## Booting Linux kernel at 40100000 ...
6103 Image Name: 2.2.13 for initrd on TQM850L
6104 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6105 Data Size: 335725 Bytes = 327 kB = 0 MB
6106 Load Address: 00000000
6107 Entry Point: 0000000c
6108 Verifying Checksum ... OK
6109 Uncompressing Kernel Image ... OK
6110 ## Loading RAMDisk Image at 40200000 ...
6111 Image Name: Simple Ramdisk Image
6112 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6113 Data Size: 566530 Bytes = 553 kB = 0 MB
6114 Load Address: 00000000
6115 Entry Point: 00000000
6116 Verifying Checksum ... OK
6117 Loading Ramdisk ... OK
6118 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
6119 Boot arguments: root=/dev/ram
6120 time_init: decrementer frequency = 187500000/60
6121 Calibrating delay loop... 49.77 BogoMIPS
6123 RAMDISK: Compressed image found at block 0
6124 VFS: Mounted root (ext2 filesystem).
6128 Boot Linux and pass a flat device tree:
6131 First, U-Boot must be compiled with the appropriate defines. See the section
6132 titled "Linux Kernel Interface" above for a more in depth explanation. The
6133 following is an example of how to start a kernel and pass an updated
6139 oft=oftrees/mpc8540ads.dtb
6140 => tftp $oftaddr $oft
6141 Speed: 1000, full duplex
6143 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6144 Filename 'oftrees/mpc8540ads.dtb'.
6145 Load address: 0x300000
6148 Bytes transferred = 4106 (100a hex)
6149 => tftp $loadaddr $bootfile
6150 Speed: 1000, full duplex
6152 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6154 Load address: 0x200000
6155 Loading:############
6157 Bytes transferred = 1029407 (fb51f hex)
6162 => bootm $loadaddr - $oftaddr
6163 ## Booting image at 00200000 ...
6164 Image Name: Linux-2.6.17-dirty
6165 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6166 Data Size: 1029343 Bytes = 1005.2 kB
6167 Load Address: 00000000
6168 Entry Point: 00000000
6169 Verifying Checksum ... OK
6170 Uncompressing Kernel Image ... OK
6171 Booting using flat device tree at 0x300000
6172 Using MPC85xx ADS machine description
6173 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6177 More About U-Boot Image Types:
6178 ------------------------------
6180 U-Boot supports the following image types:
6182 "Standalone Programs" are directly runnable in the environment
6183 provided by U-Boot; it is expected that (if they behave
6184 well) you can continue to work in U-Boot after return from
6185 the Standalone Program.
6186 "OS Kernel Images" are usually images of some Embedded OS which
6187 will take over control completely. Usually these programs
6188 will install their own set of exception handlers, device
6189 drivers, set up the MMU, etc. - this means, that you cannot
6190 expect to re-enter U-Boot except by resetting the CPU.
6191 "RAMDisk Images" are more or less just data blocks, and their
6192 parameters (address, size) are passed to an OS kernel that is
6194 "Multi-File Images" contain several images, typically an OS
6195 (Linux) kernel image and one or more data images like
6196 RAMDisks. This construct is useful for instance when you want
6197 to boot over the network using BOOTP etc., where the boot
6198 server provides just a single image file, but you want to get
6199 for instance an OS kernel and a RAMDisk image.
6201 "Multi-File Images" start with a list of image sizes, each
6202 image size (in bytes) specified by an "uint32_t" in network
6203 byte order. This list is terminated by an "(uint32_t)0".
6204 Immediately after the terminating 0 follow the images, one by
6205 one, all aligned on "uint32_t" boundaries (size rounded up to
6206 a multiple of 4 bytes).
6208 "Firmware Images" are binary images containing firmware (like
6209 U-Boot or FPGA images) which usually will be programmed to
6212 "Script files" are command sequences that will be executed by
6213 U-Boot's command interpreter; this feature is especially
6214 useful when you configure U-Boot to use a real shell (hush)
6215 as command interpreter.
6217 Booting the Linux zImage:
6218 -------------------------
6220 On some platforms, it's possible to boot Linux zImage. This is done
6221 using the "bootz" command. The syntax of "bootz" command is the same
6222 as the syntax of "bootm" command.
6224 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6225 kernel with raw initrd images. The syntax is slightly different, the
6226 address of the initrd must be augmented by it's size, in the following
6227 format: "<initrd addres>:<initrd size>".
6233 One of the features of U-Boot is that you can dynamically load and
6234 run "standalone" applications, which can use some resources of
6235 U-Boot like console I/O functions or interrupt services.
6237 Two simple examples are included with the sources:
6242 'examples/hello_world.c' contains a small "Hello World" Demo
6243 application; it is automatically compiled when you build U-Boot.
6244 It's configured to run at address 0x00040004, so you can play with it
6248 ## Ready for S-Record download ...
6249 ~>examples/hello_world.srec
6250 1 2 3 4 5 6 7 8 9 10 11 ...
6251 [file transfer complete]
6253 ## Start Addr = 0x00040004
6255 => go 40004 Hello World! This is a test.
6256 ## Starting application at 0x00040004 ...
6267 Hit any key to exit ...
6269 ## Application terminated, rc = 0x0
6271 Another example, which demonstrates how to register a CPM interrupt
6272 handler with the U-Boot code, can be found in 'examples/timer.c'.
6273 Here, a CPM timer is set up to generate an interrupt every second.
6274 The interrupt service routine is trivial, just printing a '.'
6275 character, but this is just a demo program. The application can be
6276 controlled by the following keys:
6278 ? - print current values og the CPM Timer registers
6279 b - enable interrupts and start timer
6280 e - stop timer and disable interrupts
6281 q - quit application
6284 ## Ready for S-Record download ...
6285 ~>examples/timer.srec
6286 1 2 3 4 5 6 7 8 9 10 11 ...
6287 [file transfer complete]
6289 ## Start Addr = 0x00040004
6292 ## Starting application at 0x00040004 ...
6295 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6298 [q, b, e, ?] Set interval 1000000 us
6301 [q, b, e, ?] ........
6302 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6305 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6308 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6311 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6313 [q, b, e, ?] ...Stopping timer
6315 [q, b, e, ?] ## Application terminated, rc = 0x0
6321 Over time, many people have reported problems when trying to use the
6322 "minicom" terminal emulation program for serial download. I (wd)
6323 consider minicom to be broken, and recommend not to use it. Under
6324 Unix, I recommend to use C-Kermit for general purpose use (and
6325 especially for kermit binary protocol download ("loadb" command), and
6326 use "cu" for S-Record download ("loads" command). See
6327 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6328 for help with kermit.
6331 Nevertheless, if you absolutely want to use it try adding this
6332 configuration to your "File transfer protocols" section:
6334 Name Program Name U/D FullScr IO-Red. Multi
6335 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6336 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6342 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6343 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6345 Building requires a cross environment; it is known to work on
6346 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6347 need gmake since the Makefiles are not compatible with BSD make).
6348 Note that the cross-powerpc package does not install include files;
6349 attempting to build U-Boot will fail because <machine/ansi.h> is
6350 missing. This file has to be installed and patched manually:
6352 # cd /usr/pkg/cross/powerpc-netbsd/include
6354 # ln -s powerpc machine
6355 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6356 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6358 Native builds *don't* work due to incompatibilities between native
6359 and U-Boot include files.
6361 Booting assumes that (the first part of) the image booted is a
6362 stage-2 loader which in turn loads and then invokes the kernel
6363 proper. Loader sources will eventually appear in the NetBSD source
6364 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6365 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6368 Implementation Internals:
6369 =========================
6371 The following is not intended to be a complete description of every
6372 implementation detail. However, it should help to understand the
6373 inner workings of U-Boot and make it easier to port it to custom
6377 Initial Stack, Global Data:
6378 ---------------------------
6380 The implementation of U-Boot is complicated by the fact that U-Boot
6381 starts running out of ROM (flash memory), usually without access to
6382 system RAM (because the memory controller is not initialized yet).
6383 This means that we don't have writable Data or BSS segments, and BSS
6384 is not initialized as zero. To be able to get a C environment working
6385 at all, we have to allocate at least a minimal stack. Implementation
6386 options for this are defined and restricted by the CPU used: Some CPU
6387 models provide on-chip memory (like the IMMR area on MPC8xx and
6388 MPC826x processors), on others (parts of) the data cache can be
6389 locked as (mis-) used as memory, etc.
6391 Chris Hallinan posted a good summary of these issues to the
6392 U-Boot mailing list:
6394 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6395 From: "Chris Hallinan" <clh@net1plus.com>
6396 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6399 Correct me if I'm wrong, folks, but the way I understand it
6400 is this: Using DCACHE as initial RAM for Stack, etc, does not
6401 require any physical RAM backing up the cache. The cleverness
6402 is that the cache is being used as a temporary supply of
6403 necessary storage before the SDRAM controller is setup. It's
6404 beyond the scope of this list to explain the details, but you
6405 can see how this works by studying the cache architecture and
6406 operation in the architecture and processor-specific manuals.
6408 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6409 is another option for the system designer to use as an
6410 initial stack/RAM area prior to SDRAM being available. Either
6411 option should work for you. Using CS 4 should be fine if your
6412 board designers haven't used it for something that would
6413 cause you grief during the initial boot! It is frequently not
6416 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6417 with your processor/board/system design. The default value
6418 you will find in any recent u-boot distribution in
6419 walnut.h should work for you. I'd set it to a value larger
6420 than your SDRAM module. If you have a 64MB SDRAM module, set
6421 it above 400_0000. Just make sure your board has no resources
6422 that are supposed to respond to that address! That code in
6423 start.S has been around a while and should work as is when
6424 you get the config right.
6429 It is essential to remember this, since it has some impact on the C
6430 code for the initialization procedures:
6432 * Initialized global data (data segment) is read-only. Do not attempt
6435 * Do not use any uninitialized global data (or implicitly initialized
6436 as zero data - BSS segment) at all - this is undefined, initiali-
6437 zation is performed later (when relocating to RAM).
6439 * Stack space is very limited. Avoid big data buffers or things like
6442 Having only the stack as writable memory limits means we cannot use
6443 normal global data to share information between the code. But it
6444 turned out that the implementation of U-Boot can be greatly
6445 simplified by making a global data structure (gd_t) available to all
6446 functions. We could pass a pointer to this data as argument to _all_
6447 functions, but this would bloat the code. Instead we use a feature of
6448 the GCC compiler (Global Register Variables) to share the data: we
6449 place a pointer (gd) to the global data into a register which we
6450 reserve for this purpose.
6452 When choosing a register for such a purpose we are restricted by the
6453 relevant (E)ABI specifications for the current architecture, and by
6454 GCC's implementation.
6456 For PowerPC, the following registers have specific use:
6458 R2: reserved for system use
6459 R3-R4: parameter passing and return values
6460 R5-R10: parameter passing
6461 R13: small data area pointer
6465 (U-Boot also uses R12 as internal GOT pointer. r12
6466 is a volatile register so r12 needs to be reset when
6467 going back and forth between asm and C)
6469 ==> U-Boot will use R2 to hold a pointer to the global data
6471 Note: on PPC, we could use a static initializer (since the
6472 address of the global data structure is known at compile time),
6473 but it turned out that reserving a register results in somewhat
6474 smaller code - although the code savings are not that big (on
6475 average for all boards 752 bytes for the whole U-Boot image,
6476 624 text + 127 data).
6478 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6479 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6481 ==> U-Boot will use P3 to hold a pointer to the global data
6483 On ARM, the following registers are used:
6485 R0: function argument word/integer result
6486 R1-R3: function argument word
6487 R9: platform specific
6488 R10: stack limit (used only if stack checking is enabled)
6489 R11: argument (frame) pointer
6490 R12: temporary workspace
6493 R15: program counter
6495 ==> U-Boot will use R9 to hold a pointer to the global data
6497 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6499 On Nios II, the ABI is documented here:
6500 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6502 ==> U-Boot will use gp to hold a pointer to the global data
6504 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6505 to access small data sections, so gp is free.
6507 On NDS32, the following registers are used:
6509 R0-R1: argument/return
6511 R15: temporary register for assembler
6512 R16: trampoline register
6513 R28: frame pointer (FP)
6514 R29: global pointer (GP)
6515 R30: link register (LP)
6516 R31: stack pointer (SP)
6517 PC: program counter (PC)
6519 ==> U-Boot will use R10 to hold a pointer to the global data
6521 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6522 or current versions of GCC may "optimize" the code too much.
6527 U-Boot runs in system state and uses physical addresses, i.e. the
6528 MMU is not used either for address mapping nor for memory protection.
6530 The available memory is mapped to fixed addresses using the memory
6531 controller. In this process, a contiguous block is formed for each
6532 memory type (Flash, SDRAM, SRAM), even when it consists of several
6533 physical memory banks.
6535 U-Boot is installed in the first 128 kB of the first Flash bank (on
6536 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6537 booting and sizing and initializing DRAM, the code relocates itself
6538 to the upper end of DRAM. Immediately below the U-Boot code some
6539 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6540 configuration setting]. Below that, a structure with global Board
6541 Info data is placed, followed by the stack (growing downward).
6543 Additionally, some exception handler code is copied to the low 8 kB
6544 of DRAM (0x00000000 ... 0x00001FFF).
6546 So a typical memory configuration with 16 MB of DRAM could look like
6549 0x0000 0000 Exception Vector code
6552 0x0000 2000 Free for Application Use
6558 0x00FB FF20 Monitor Stack (Growing downward)
6559 0x00FB FFAC Board Info Data and permanent copy of global data
6560 0x00FC 0000 Malloc Arena
6563 0x00FE 0000 RAM Copy of Monitor Code
6564 ... eventually: LCD or video framebuffer
6565 ... eventually: pRAM (Protected RAM - unchanged by reset)
6566 0x00FF FFFF [End of RAM]
6569 System Initialization:
6570 ----------------------
6572 In the reset configuration, U-Boot starts at the reset entry point
6573 (on most PowerPC systems at address 0x00000100). Because of the reset
6574 configuration for CS0# this is a mirror of the on board Flash memory.
6575 To be able to re-map memory U-Boot then jumps to its link address.
6576 To be able to implement the initialization code in C, a (small!)
6577 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6578 which provide such a feature like MPC8xx or MPC8260), or in a locked
6579 part of the data cache. After that, U-Boot initializes the CPU core,
6580 the caches and the SIU.
6582 Next, all (potentially) available memory banks are mapped using a
6583 preliminary mapping. For example, we put them on 512 MB boundaries
6584 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6585 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6586 programmed for SDRAM access. Using the temporary configuration, a
6587 simple memory test is run that determines the size of the SDRAM
6590 When there is more than one SDRAM bank, and the banks are of
6591 different size, the largest is mapped first. For equal size, the first
6592 bank (CS2#) is mapped first. The first mapping is always for address
6593 0x00000000, with any additional banks following immediately to create
6594 contiguous memory starting from 0.
6596 Then, the monitor installs itself at the upper end of the SDRAM area
6597 and allocates memory for use by malloc() and for the global Board
6598 Info data; also, the exception vector code is copied to the low RAM
6599 pages, and the final stack is set up.
6601 Only after this relocation will you have a "normal" C environment;
6602 until that you are restricted in several ways, mostly because you are
6603 running from ROM, and because the code will have to be relocated to a
6607 U-Boot Porting Guide:
6608 ----------------------
6610 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6614 int main(int argc, char *argv[])
6616 sighandler_t no_more_time;
6618 signal(SIGALRM, no_more_time);
6619 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6621 if (available_money > available_manpower) {
6622 Pay consultant to port U-Boot;
6626 Download latest U-Boot source;
6628 Subscribe to u-boot mailing list;
6631 email("Hi, I am new to U-Boot, how do I get started?");
6634 Read the README file in the top level directory;
6635 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6636 Read applicable doc/*.README;
6637 Read the source, Luke;
6638 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6641 if (available_money > toLocalCurrency ($2500))
6644 Add a lot of aggravation and time;
6646 if (a similar board exists) { /* hopefully... */
6647 cp -a board/<similar> board/<myboard>
6648 cp include/configs/<similar>.h include/configs/<myboard>.h
6650 Create your own board support subdirectory;
6651 Create your own board include/configs/<myboard>.h file;
6653 Edit new board/<myboard> files
6654 Edit new include/configs/<myboard>.h
6659 Add / modify source code;
6663 email("Hi, I am having problems...");
6665 Send patch file to the U-Boot email list;
6666 if (reasonable critiques)
6667 Incorporate improvements from email list code review;
6669 Defend code as written;
6675 void no_more_time (int sig)
6684 All contributions to U-Boot should conform to the Linux kernel
6685 coding style; see the file "Documentation/CodingStyle" and the script
6686 "scripts/Lindent" in your Linux kernel source directory.
6688 Source files originating from a different project (for example the
6689 MTD subsystem) are generally exempt from these guidelines and are not
6690 reformatted to ease subsequent migration to newer versions of those
6693 Please note that U-Boot is implemented in C (and to some small parts in
6694 Assembler); no C++ is used, so please do not use C++ style comments (//)
6697 Please also stick to the following formatting rules:
6698 - remove any trailing white space
6699 - use TAB characters for indentation and vertical alignment, not spaces
6700 - make sure NOT to use DOS '\r\n' line feeds
6701 - do not add more than 2 consecutive empty lines to source files
6702 - do not add trailing empty lines to source files
6704 Submissions which do not conform to the standards may be returned
6705 with a request to reformat the changes.
6711 Since the number of patches for U-Boot is growing, we need to
6712 establish some rules. Submissions which do not conform to these rules
6713 may be rejected, even when they contain important and valuable stuff.
6715 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6717 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6718 see http://lists.denx.de/mailman/listinfo/u-boot
6720 When you send a patch, please include the following information with
6723 * For bug fixes: a description of the bug and how your patch fixes
6724 this bug. Please try to include a way of demonstrating that the
6725 patch actually fixes something.
6727 * For new features: a description of the feature and your
6730 * A CHANGELOG entry as plaintext (separate from the patch)
6732 * For major contributions, your entry to the CREDITS file
6734 * When you add support for a new board, don't forget to add a
6735 maintainer e-mail address to the boards.cfg file, too.
6737 * If your patch adds new configuration options, don't forget to
6738 document these in the README file.
6740 * The patch itself. If you are using git (which is *strongly*
6741 recommended) you can easily generate the patch using the
6742 "git format-patch". If you then use "git send-email" to send it to
6743 the U-Boot mailing list, you will avoid most of the common problems
6744 with some other mail clients.
6746 If you cannot use git, use "diff -purN OLD NEW". If your version of
6747 diff does not support these options, then get the latest version of
6750 The current directory when running this command shall be the parent
6751 directory of the U-Boot source tree (i. e. please make sure that
6752 your patch includes sufficient directory information for the
6755 We prefer patches as plain text. MIME attachments are discouraged,
6756 and compressed attachments must not be used.
6758 * If one logical set of modifications affects or creates several
6759 files, all these changes shall be submitted in a SINGLE patch file.
6761 * Changesets that contain different, unrelated modifications shall be
6762 submitted as SEPARATE patches, one patch per changeset.
6767 * Before sending the patch, run the MAKEALL script on your patched
6768 source tree and make sure that no errors or warnings are reported
6769 for any of the boards.
6771 * Keep your modifications to the necessary minimum: A patch
6772 containing several unrelated changes or arbitrary reformats will be
6773 returned with a request to re-formatting / split it.
6775 * If you modify existing code, make sure that your new code does not
6776 add to the memory footprint of the code ;-) Small is beautiful!
6777 When adding new features, these should compile conditionally only
6778 (using #ifdef), and the resulting code with the new feature
6779 disabled must not need more memory than the old code without your
6782 * Remember that there is a size limit of 100 kB per message on the
6783 u-boot mailing list. Bigger patches will be moderated. If they are
6784 reasonable and not too big, they will be acknowledged. But patches
6785 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob