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 adding #define's for wanted commands.
1163 The default command configuration includes all commands
1164 except those marked below with a "*".
1166 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1167 CONFIG_CMD_ASKENV * ask for env variable
1168 CONFIG_CMD_BDI bdinfo
1169 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1170 CONFIG_CMD_BMP * BMP support
1171 CONFIG_CMD_BSP * Board specific commands
1172 CONFIG_CMD_BOOTD bootd
1173 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1174 CONFIG_CMD_CACHE * icache, dcache
1175 CONFIG_CMD_CLK * clock command support
1176 CONFIG_CMD_CONSOLE coninfo
1177 CONFIG_CMD_CRC32 * crc32
1178 CONFIG_CMD_DATE * support for RTC, date/time...
1179 CONFIG_CMD_DHCP * DHCP support
1180 CONFIG_CMD_DIAG * Diagnostics
1181 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1182 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1183 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1184 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1185 CONFIG_CMD_DTT * Digital Therm and Thermostat
1186 CONFIG_CMD_ECHO echo arguments
1187 CONFIG_CMD_EDITENV edit env variable
1188 CONFIG_CMD_EEPROM * EEPROM read/write support
1189 CONFIG_CMD_ELF * bootelf, bootvx
1190 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1191 CONFIG_CMD_ENV_FLAGS * display details about env flags
1192 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1193 CONFIG_CMD_EXPORTENV * export the environment
1194 CONFIG_CMD_EXT2 * ext2 command support
1195 CONFIG_CMD_EXT4 * ext4 command support
1196 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1197 that work for multiple fs types
1198 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1199 CONFIG_CMD_SAVEENV saveenv
1200 CONFIG_CMD_FDC * Floppy Disk Support
1201 CONFIG_CMD_FAT * FAT command support
1202 CONFIG_CMD_FLASH flinfo, erase, protect
1203 CONFIG_CMD_FPGA FPGA device initialization support
1204 CONFIG_CMD_FUSE * Device fuse support
1205 CONFIG_CMD_GETTIME * Get time since boot
1206 CONFIG_CMD_GO * the 'go' command (exec code)
1207 CONFIG_CMD_GREPENV * search environment
1208 CONFIG_CMD_HASH * calculate hash / digest
1209 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1210 CONFIG_CMD_I2C * I2C serial bus support
1211 CONFIG_CMD_IDE * IDE harddisk support
1212 CONFIG_CMD_IMI iminfo
1213 CONFIG_CMD_IMLS List all images found in NOR flash
1214 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1215 CONFIG_CMD_IMMAP * IMMR dump support
1216 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1217 CONFIG_CMD_IMPORTENV * import an environment
1218 CONFIG_CMD_INI * import data from an ini file into the env
1219 CONFIG_CMD_IRQ * irqinfo
1220 CONFIG_CMD_ITEST Integer/string test of 2 values
1221 CONFIG_CMD_JFFS2 * JFFS2 Support
1222 CONFIG_CMD_KGDB * kgdb
1223 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1224 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1226 CONFIG_CMD_LOADB loadb
1227 CONFIG_CMD_LOADS loads
1228 CONFIG_CMD_MD5SUM * print md5 message digest
1229 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1230 CONFIG_CMD_MEMINFO * Display detailed memory information
1231 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1233 CONFIG_CMD_MEMTEST * mtest
1234 CONFIG_CMD_MISC Misc functions like sleep etc
1235 CONFIG_CMD_MMC * MMC memory mapped support
1236 CONFIG_CMD_MII * MII utility commands
1237 CONFIG_CMD_MTDPARTS * MTD partition support
1238 CONFIG_CMD_NAND * NAND support
1239 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1240 CONFIG_CMD_NFS NFS support
1241 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1242 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1243 CONFIG_CMD_PCI * pciinfo
1244 CONFIG_CMD_PCMCIA * PCMCIA support
1245 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1247 CONFIG_CMD_PORTIO * Port I/O
1248 CONFIG_CMD_READ * Read raw data from partition
1249 CONFIG_CMD_REGINFO * Register dump
1250 CONFIG_CMD_RUN run command in env variable
1251 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1252 CONFIG_CMD_SAVES * save S record dump
1253 CONFIG_CMD_SCSI * SCSI Support
1254 CONFIG_CMD_SDRAM * print SDRAM configuration information
1255 (requires CONFIG_CMD_I2C)
1256 CONFIG_CMD_SETGETDCR Support for DCR Register access
1258 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1259 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1260 (requires CONFIG_CMD_MEMORY)
1261 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1262 CONFIG_CMD_SOURCE "source" command Support
1263 CONFIG_CMD_SPI * SPI serial bus support
1264 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1265 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1266 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1267 CONFIG_CMD_TIMER * access to the system tick timer
1268 CONFIG_CMD_USB * USB support
1269 CONFIG_CMD_CDP * Cisco Discover Protocol support
1270 CONFIG_CMD_MFSL * Microblaze FSL support
1271 CONFIG_CMD_XIMG Load part of Multi Image
1272 CONFIG_CMD_UUID * Generate random UUID or GUID string
1274 EXAMPLE: If you want all functions except of network
1275 support you can write:
1277 #include "config_cmd_all.h"
1278 #undef CONFIG_CMD_NET
1281 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1283 Note: Don't enable the "icache" and "dcache" commands
1284 (configuration option CONFIG_CMD_CACHE) unless you know
1285 what you (and your U-Boot users) are doing. Data
1286 cache cannot be enabled on systems like the 8xx or
1287 8260 (where accesses to the IMMR region must be
1288 uncached), and it cannot be disabled on all other
1289 systems where we (mis-) use the data cache to hold an
1290 initial stack and some data.
1293 XXX - this list needs to get updated!
1295 - Regular expression support:
1297 If this variable is defined, U-Boot is linked against
1298 the SLRE (Super Light Regular Expression) library,
1299 which adds regex support to some commands, as for
1300 example "env grep" and "setexpr".
1304 If this variable is defined, U-Boot will use a device tree
1305 to configure its devices, instead of relying on statically
1306 compiled #defines in the board file. This option is
1307 experimental and only available on a few boards. The device
1308 tree is available in the global data as gd->fdt_blob.
1310 U-Boot needs to get its device tree from somewhere. This can
1311 be done using one of the two options below:
1314 If this variable is defined, U-Boot will embed a device tree
1315 binary in its image. This device tree file should be in the
1316 board directory and called <soc>-<board>.dts. The binary file
1317 is then picked up in board_init_f() and made available through
1318 the global data structure as gd->blob.
1321 If this variable is defined, U-Boot will build a device tree
1322 binary. It will be called u-boot.dtb. Architecture-specific
1323 code will locate it at run-time. Generally this works by:
1325 cat u-boot.bin u-boot.dtb >image.bin
1327 and in fact, U-Boot does this for you, creating a file called
1328 u-boot-dtb.bin which is useful in the common case. You can
1329 still use the individual files if you need something more
1334 If this variable is defined, it enables watchdog
1335 support for the SoC. There must be support in the SoC
1336 specific code for a watchdog. For the 8xx and 8260
1337 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1338 register. When supported for a specific SoC is
1339 available, then no further board specific code should
1340 be needed to use it.
1343 When using a watchdog circuitry external to the used
1344 SoC, then define this variable and provide board
1345 specific code for the "hw_watchdog_reset" function.
1347 CONFIG_AT91_HW_WDT_TIMEOUT
1348 specify the timeout in seconds. default 2 seconds.
1351 CONFIG_VERSION_VARIABLE
1352 If this variable is defined, an environment variable
1353 named "ver" is created by U-Boot showing the U-Boot
1354 version as printed by the "version" command.
1355 Any change to this variable will be reverted at the
1360 When CONFIG_CMD_DATE is selected, the type of the RTC
1361 has to be selected, too. Define exactly one of the
1364 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1365 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1366 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1367 CONFIG_RTC_MC146818 - use MC146818 RTC
1368 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1369 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1370 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1371 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1372 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1373 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1374 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1375 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1376 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1379 Note that if the RTC uses I2C, then the I2C interface
1380 must also be configured. See I2C Support, below.
1383 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1385 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1386 chip-ngpio pairs that tell the PCA953X driver the number of
1387 pins supported by a particular chip.
1389 Note that if the GPIO device uses I2C, then the I2C interface
1390 must also be configured. See I2C Support, below.
1393 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1394 accesses and can checksum them or write a list of them out
1395 to memory. See the 'iotrace' command for details. This is
1396 useful for testing device drivers since it can confirm that
1397 the driver behaves the same way before and after a code
1398 change. Currently this is supported on sandbox and arm. To
1399 add support for your architecture, add '#include <iotrace.h>'
1400 to the bottom of arch/<arch>/include/asm/io.h and test.
1402 Example output from the 'iotrace stats' command is below.
1403 Note that if the trace buffer is exhausted, the checksum will
1404 still continue to operate.
1407 Start: 10000000 (buffer start address)
1408 Size: 00010000 (buffer size)
1409 Offset: 00000120 (current buffer offset)
1410 Output: 10000120 (start + offset)
1411 Count: 00000018 (number of trace records)
1412 CRC32: 9526fb66 (CRC32 of all trace records)
1414 - Timestamp Support:
1416 When CONFIG_TIMESTAMP is selected, the timestamp
1417 (date and time) of an image is printed by image
1418 commands like bootm or iminfo. This option is
1419 automatically enabled when you select CONFIG_CMD_DATE .
1421 - Partition Labels (disklabels) Supported:
1422 Zero or more of the following:
1423 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1424 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1425 Intel architecture, USB sticks, etc.
1426 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1427 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1428 bootloader. Note 2TB partition limit; see
1430 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1432 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1433 CONFIG_CMD_SCSI) you must configure support for at
1434 least one non-MTD partition type as well.
1437 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1438 board configurations files but used nowhere!
1440 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1441 be performed by calling the function
1442 ide_set_reset(int reset)
1443 which has to be defined in a board specific file
1448 Set this to enable ATAPI support.
1453 Set this to enable support for disks larger than 137GB
1454 Also look at CONFIG_SYS_64BIT_LBA.
1455 Whithout these , LBA48 support uses 32bit variables and will 'only'
1456 support disks up to 2.1TB.
1458 CONFIG_SYS_64BIT_LBA:
1459 When enabled, makes the IDE subsystem use 64bit sector addresses.
1463 At the moment only there is only support for the
1464 SYM53C8XX SCSI controller; define
1465 CONFIG_SCSI_SYM53C8XX to enable it.
1467 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1468 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1469 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1470 maximum numbers of LUNs, SCSI ID's and target
1472 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1474 The environment variable 'scsidevs' is set to the number of
1475 SCSI devices found during the last scan.
1477 - NETWORK Support (PCI):
1479 Support for Intel 8254x/8257x gigabit chips.
1482 Utility code for direct access to the SPI bus on Intel 8257x.
1483 This does not do anything useful unless you set at least one
1484 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1486 CONFIG_E1000_SPI_GENERIC
1487 Allow generic access to the SPI bus on the Intel 8257x, for
1488 example with the "sspi" command.
1491 Management command for E1000 devices. When used on devices
1492 with SPI support you can reprogram the EEPROM from U-Boot.
1494 CONFIG_E1000_FALLBACK_MAC
1495 default MAC for empty EEPROM after production.
1498 Support for Intel 82557/82559/82559ER chips.
1499 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1500 write routine for first time initialisation.
1503 Support for Digital 2114x chips.
1504 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1505 modem chip initialisation (KS8761/QS6611).
1508 Support for National dp83815 chips.
1511 Support for National dp8382[01] gigabit chips.
1513 - NETWORK Support (other):
1515 CONFIG_DRIVER_AT91EMAC
1516 Support for AT91RM9200 EMAC.
1519 Define this to use reduced MII inteface
1521 CONFIG_DRIVER_AT91EMAC_QUIET
1522 If this defined, the driver is quiet.
1523 The driver doen't show link status messages.
1525 CONFIG_CALXEDA_XGMAC
1526 Support for the Calxeda XGMAC device
1529 Support for SMSC's LAN91C96 chips.
1531 CONFIG_LAN91C96_BASE
1532 Define this to hold the physical address
1533 of the LAN91C96's I/O space
1535 CONFIG_LAN91C96_USE_32_BIT
1536 Define this to enable 32 bit addressing
1539 Support for SMSC's LAN91C111 chip
1541 CONFIG_SMC91111_BASE
1542 Define this to hold the physical address
1543 of the device (I/O space)
1545 CONFIG_SMC_USE_32_BIT
1546 Define this if data bus is 32 bits
1548 CONFIG_SMC_USE_IOFUNCS
1549 Define this to use i/o functions instead of macros
1550 (some hardware wont work with macros)
1552 CONFIG_DRIVER_TI_EMAC
1553 Support for davinci emac
1555 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1556 Define this if you have more then 3 PHYs.
1559 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1561 CONFIG_FTGMAC100_EGIGA
1562 Define this to use GE link update with gigabit PHY.
1563 Define this if FTGMAC100 is connected to gigabit PHY.
1564 If your system has 10/100 PHY only, it might not occur
1565 wrong behavior. Because PHY usually return timeout or
1566 useless data when polling gigabit status and gigabit
1567 control registers. This behavior won't affect the
1568 correctnessof 10/100 link speed update.
1571 Support for SMSC's LAN911x and LAN921x chips
1574 Define this to hold the physical address
1575 of the device (I/O space)
1577 CONFIG_SMC911X_32_BIT
1578 Define this if data bus is 32 bits
1580 CONFIG_SMC911X_16_BIT
1581 Define this if data bus is 16 bits. If your processor
1582 automatically converts one 32 bit word to two 16 bit
1583 words you may also try CONFIG_SMC911X_32_BIT.
1586 Support for Renesas on-chip Ethernet controller
1588 CONFIG_SH_ETHER_USE_PORT
1589 Define the number of ports to be used
1591 CONFIG_SH_ETHER_PHY_ADDR
1592 Define the ETH PHY's address
1594 CONFIG_SH_ETHER_CACHE_WRITEBACK
1595 If this option is set, the driver enables cache flush.
1599 Support for PWM modul on the imx6.
1603 Support TPM devices.
1606 Support for i2c bus TPM devices. Only one device
1607 per system is supported at this time.
1609 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1610 Define the the i2c bus number for the TPM device
1612 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1613 Define the TPM's address on the i2c bus
1615 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1616 Define the burst count bytes upper limit
1618 CONFIG_TPM_ATMEL_TWI
1619 Support for Atmel TWI TPM device. Requires I2C support.
1622 Support for generic parallel port TPM devices. Only one device
1623 per system is supported at this time.
1625 CONFIG_TPM_TIS_BASE_ADDRESS
1626 Base address where the generic TPM device is mapped
1627 to. Contemporary x86 systems usually map it at
1631 Add tpm monitor functions.
1632 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1633 provides monitor access to authorized functions.
1636 Define this to enable the TPM support library which provides
1637 functional interfaces to some TPM commands.
1638 Requires support for a TPM device.
1640 CONFIG_TPM_AUTH_SESSIONS
1641 Define this to enable authorized functions in the TPM library.
1642 Requires CONFIG_TPM and CONFIG_SHA1.
1645 At the moment only the UHCI host controller is
1646 supported (PIP405, MIP405, MPC5200); define
1647 CONFIG_USB_UHCI to enable it.
1648 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1649 and define CONFIG_USB_STORAGE to enable the USB
1652 Supported are USB Keyboards and USB Floppy drives
1654 MPC5200 USB requires additional defines:
1656 for 528 MHz Clock: 0x0001bbbb
1660 for differential drivers: 0x00001000
1661 for single ended drivers: 0x00005000
1662 for differential drivers on PSC3: 0x00000100
1663 for single ended drivers on PSC3: 0x00004100
1664 CONFIG_SYS_USB_EVENT_POLL
1665 May be defined to allow interrupt polling
1666 instead of using asynchronous interrupts
1668 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1669 txfilltuning field in the EHCI controller on reset.
1671 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1672 HW module registers.
1675 Define the below if you wish to use the USB console.
1676 Once firmware is rebuilt from a serial console issue the
1677 command "setenv stdin usbtty; setenv stdout usbtty" and
1678 attach your USB cable. The Unix command "dmesg" should print
1679 it has found a new device. The environment variable usbtty
1680 can be set to gserial or cdc_acm to enable your device to
1681 appear to a USB host as a Linux gserial device or a
1682 Common Device Class Abstract Control Model serial device.
1683 If you select usbtty = gserial you should be able to enumerate
1685 # modprobe usbserial vendor=0xVendorID product=0xProductID
1686 else if using cdc_acm, simply setting the environment
1687 variable usbtty to be cdc_acm should suffice. The following
1688 might be defined in YourBoardName.h
1691 Define this to build a UDC device
1694 Define this to have a tty type of device available to
1695 talk to the UDC device
1698 Define this to enable the high speed support for usb
1699 device and usbtty. If this feature is enabled, a routine
1700 int is_usbd_high_speed(void)
1701 also needs to be defined by the driver to dynamically poll
1702 whether the enumeration has succeded at high speed or full
1705 CONFIG_SYS_CONSOLE_IS_IN_ENV
1706 Define this if you want stdin, stdout &/or stderr to
1710 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1711 Derive USB clock from external clock "blah"
1712 - CONFIG_SYS_USB_EXTC_CLK 0x02
1714 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1715 Derive USB clock from brgclk
1716 - CONFIG_SYS_USB_BRG_CLK 0x04
1718 If you have a USB-IF assigned VendorID then you may wish to
1719 define your own vendor specific values either in BoardName.h
1720 or directly in usbd_vendor_info.h. If you don't define
1721 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1722 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1723 should pretend to be a Linux device to it's target host.
1725 CONFIG_USBD_MANUFACTURER
1726 Define this string as the name of your company for
1727 - CONFIG_USBD_MANUFACTURER "my company"
1729 CONFIG_USBD_PRODUCT_NAME
1730 Define this string as the name of your product
1731 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1733 CONFIG_USBD_VENDORID
1734 Define this as your assigned Vendor ID from the USB
1735 Implementors Forum. This *must* be a genuine Vendor ID
1736 to avoid polluting the USB namespace.
1737 - CONFIG_USBD_VENDORID 0xFFFF
1739 CONFIG_USBD_PRODUCTID
1740 Define this as the unique Product ID
1742 - CONFIG_USBD_PRODUCTID 0xFFFF
1744 - ULPI Layer Support:
1745 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1746 the generic ULPI layer. The generic layer accesses the ULPI PHY
1747 via the platform viewport, so you need both the genric layer and
1748 the viewport enabled. Currently only Chipidea/ARC based
1749 viewport is supported.
1750 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1751 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1752 If your ULPI phy needs a different reference clock than the
1753 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1754 the appropriate value in Hz.
1757 The MMC controller on the Intel PXA is supported. To
1758 enable this define CONFIG_MMC. The MMC can be
1759 accessed from the boot prompt by mapping the device
1760 to physical memory similar to flash. Command line is
1761 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1762 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1765 Support for Renesas on-chip MMCIF controller
1767 CONFIG_SH_MMCIF_ADDR
1768 Define the base address of MMCIF registers
1771 Define the clock frequency for MMCIF
1774 Enable the generic MMC driver
1776 CONFIG_SUPPORT_EMMC_BOOT
1777 Enable some additional features of the eMMC boot partitions.
1779 CONFIG_SUPPORT_EMMC_RPMB
1780 Enable the commands for reading, writing and programming the
1781 key for the Replay Protection Memory Block partition in eMMC.
1783 - USB Device Firmware Update (DFU) class support:
1785 This enables the USB portion of the DFU USB class
1788 This enables the command "dfu" which is used to have
1789 U-Boot create a DFU class device via USB. This command
1790 requires that the "dfu_alt_info" environment variable be
1791 set and define the alt settings to expose to the host.
1794 This enables support for exposing (e)MMC devices via DFU.
1797 This enables support for exposing NAND devices via DFU.
1800 This enables support for exposing RAM via DFU.
1801 Note: DFU spec refer to non-volatile memory usage, but
1802 allow usages beyond the scope of spec - here RAM usage,
1803 one that would help mostly the developer.
1805 CONFIG_SYS_DFU_DATA_BUF_SIZE
1806 Dfu transfer uses a buffer before writing data to the
1807 raw storage device. Make the size (in bytes) of this buffer
1808 configurable. The size of this buffer is also configurable
1809 through the "dfu_bufsiz" environment variable.
1811 CONFIG_SYS_DFU_MAX_FILE_SIZE
1812 When updating files rather than the raw storage device,
1813 we use a static buffer to copy the file into and then write
1814 the buffer once we've been given the whole file. Define
1815 this to the maximum filesize (in bytes) for the buffer.
1816 Default is 4 MiB if undefined.
1818 DFU_DEFAULT_POLL_TIMEOUT
1819 Poll timeout [ms], is the timeout a device can send to the
1820 host. The host must wait for this timeout before sending
1821 a subsequent DFU_GET_STATUS request to the device.
1823 DFU_MANIFEST_POLL_TIMEOUT
1824 Poll timeout [ms], which the device sends to the host when
1825 entering dfuMANIFEST state. Host waits this timeout, before
1826 sending again an USB request to the device.
1828 - USB Device Android Fastboot support:
1830 This enables the command "fastboot" which enables the Android
1831 fastboot mode for the platform's USB device. Fastboot is a USB
1832 protocol for downloading images, flashing and device control
1833 used on Android devices.
1834 See doc/README.android-fastboot for more information.
1836 CONFIG_ANDROID_BOOT_IMAGE
1837 This enables support for booting images which use the Android
1838 image format header.
1840 CONFIG_USB_FASTBOOT_BUF_ADDR
1841 The fastboot protocol requires a large memory buffer for
1842 downloads. Define this to the starting RAM address to use for
1845 CONFIG_USB_FASTBOOT_BUF_SIZE
1846 The fastboot protocol requires a large memory buffer for
1847 downloads. This buffer should be as large as possible for a
1848 platform. Define this to the size available RAM for fastboot.
1850 CONFIG_FASTBOOT_FLASH
1851 The fastboot protocol includes a "flash" command for writing
1852 the downloaded image to a non-volatile storage device. Define
1853 this to enable the "fastboot flash" command.
1855 CONFIG_FASTBOOT_FLASH_MMC_DEV
1856 The fastboot "flash" command requires additional information
1857 regarding the non-volatile storage device. Define this to
1858 the eMMC device that fastboot should use to store the image.
1860 CONFIG_FASTBOOT_GPT_NAME
1861 The fastboot "flash" command supports writing the downloaded
1862 image to the Protective MBR and the Primary GUID Partition
1863 Table. (Additionally, this downloaded image is post-processed
1864 to generate and write the Backup GUID Partition Table.)
1865 This occurs when the specified "partition name" on the
1866 "fastboot flash" command line matches this value.
1867 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1869 - Journaling Flash filesystem support:
1870 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1871 CONFIG_JFFS2_NAND_DEV
1872 Define these for a default partition on a NAND device
1874 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1875 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1876 Define these for a default partition on a NOR device
1878 CONFIG_SYS_JFFS_CUSTOM_PART
1879 Define this to create an own partition. You have to provide a
1880 function struct part_info* jffs2_part_info(int part_num)
1882 If you define only one JFFS2 partition you may also want to
1883 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1884 to disable the command chpart. This is the default when you
1885 have not defined a custom partition
1887 - FAT(File Allocation Table) filesystem write function support:
1890 Define this to enable support for saving memory data as a
1891 file in FAT formatted partition.
1893 This will also enable the command "fatwrite" enabling the
1894 user to write files to FAT.
1896 CBFS (Coreboot Filesystem) support
1899 Define this to enable support for reading from a Coreboot
1900 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1903 - FAT(File Allocation Table) filesystem cluster size:
1904 CONFIG_FS_FAT_MAX_CLUSTSIZE
1906 Define the max cluster size for fat operations else
1907 a default value of 65536 will be defined.
1912 Define this to enable standard (PC-Style) keyboard
1916 Standard PC keyboard driver with US (is default) and
1917 GERMAN key layout (switch via environment 'keymap=de') support.
1918 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1919 for cfb_console. Supports cursor blinking.
1922 Enables a Chrome OS keyboard using the CROS_EC interface.
1923 This uses CROS_EC to communicate with a second microcontroller
1924 which provides key scans on request.
1929 Define this to enable video support (for output to
1932 CONFIG_VIDEO_CT69000
1934 Enable Chips & Technologies 69000 Video chip
1936 CONFIG_VIDEO_SMI_LYNXEM
1937 Enable Silicon Motion SMI 712/710/810 Video chip. The
1938 video output is selected via environment 'videoout'
1939 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1942 For the CT69000 and SMI_LYNXEM drivers, videomode is
1943 selected via environment 'videomode'. Two different ways
1945 - "videomode=num" 'num' is a standard LiLo mode numbers.
1946 Following standard modes are supported (* is default):
1948 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1949 -------------+---------------------------------------------
1950 8 bits | 0x301* 0x303 0x305 0x161 0x307
1951 15 bits | 0x310 0x313 0x316 0x162 0x319
1952 16 bits | 0x311 0x314 0x317 0x163 0x31A
1953 24 bits | 0x312 0x315 0x318 ? 0x31B
1954 -------------+---------------------------------------------
1955 (i.e. setenv videomode 317; saveenv; reset;)
1957 - "videomode=bootargs" all the video parameters are parsed
1958 from the bootargs. (See drivers/video/videomodes.c)
1961 CONFIG_VIDEO_SED13806
1962 Enable Epson SED13806 driver. This driver supports 8bpp
1963 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1964 or CONFIG_VIDEO_SED13806_16BPP
1967 Enable the Freescale DIU video driver. Reference boards for
1968 SOCs that have a DIU should define this macro to enable DIU
1969 support, and should also define these other macros:
1975 CONFIG_VIDEO_SW_CURSOR
1976 CONFIG_VGA_AS_SINGLE_DEVICE
1978 CONFIG_VIDEO_BMP_LOGO
1980 The DIU driver will look for the 'video-mode' environment
1981 variable, and if defined, enable the DIU as a console during
1982 boot. See the documentation file README.video for a
1983 description of this variable.
1989 Define this to enable a custom keyboard support.
1990 This simply calls drv_keyboard_init() which must be
1991 defined in your board-specific files.
1992 The only board using this so far is RBC823.
1994 - LCD Support: CONFIG_LCD
1996 Define this to enable LCD support (for output to LCD
1997 display); also select one of the supported displays
1998 by defining one of these:
2002 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2004 CONFIG_NEC_NL6448AC33:
2006 NEC NL6448AC33-18. Active, color, single scan.
2008 CONFIG_NEC_NL6448BC20
2010 NEC NL6448BC20-08. 6.5", 640x480.
2011 Active, color, single scan.
2013 CONFIG_NEC_NL6448BC33_54
2015 NEC NL6448BC33-54. 10.4", 640x480.
2016 Active, color, single scan.
2020 Sharp 320x240. Active, color, single scan.
2021 It isn't 16x9, and I am not sure what it is.
2023 CONFIG_SHARP_LQ64D341
2025 Sharp LQ64D341 display, 640x480.
2026 Active, color, single scan.
2030 HLD1045 display, 640x480.
2031 Active, color, single scan.
2035 Optrex CBL50840-2 NF-FW 99 22 M5
2037 Hitachi LMG6912RPFC-00T
2041 320x240. Black & white.
2043 Normally display is black on white background; define
2044 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2046 CONFIG_LCD_ALIGNMENT
2048 Normally the LCD is page-aligned (typically 4KB). If this is
2049 defined then the LCD will be aligned to this value instead.
2050 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2051 here, since it is cheaper to change data cache settings on
2052 a per-section basis.
2054 CONFIG_CONSOLE_SCROLL_LINES
2056 When the console need to be scrolled, this is the number of
2057 lines to scroll by. It defaults to 1. Increasing this makes
2058 the console jump but can help speed up operation when scrolling
2063 Sometimes, for example if the display is mounted in portrait
2064 mode or even if it's mounted landscape but rotated by 180degree,
2065 we need to rotate our content of the display relative to the
2066 framebuffer, so that user can read the messages which are
2068 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2069 initialized with a given rotation from "vl_rot" out of
2070 "vidinfo_t" which is provided by the board specific code.
2071 The value for vl_rot is coded as following (matching to
2072 fbcon=rotate:<n> linux-kernel commandline):
2073 0 = no rotation respectively 0 degree
2074 1 = 90 degree rotation
2075 2 = 180 degree rotation
2076 3 = 270 degree rotation
2078 If CONFIG_LCD_ROTATION is not defined, the console will be
2079 initialized with 0degree rotation.
2083 Support drawing of RLE8-compressed bitmaps on the LCD.
2087 Enables an 'i2c edid' command which can read EDID
2088 information over I2C from an attached LCD display.
2090 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2092 If this option is set, the environment is checked for
2093 a variable "splashimage". If found, the usual display
2094 of logo, copyright and system information on the LCD
2095 is suppressed and the BMP image at the address
2096 specified in "splashimage" is loaded instead. The
2097 console is redirected to the "nulldev", too. This
2098 allows for a "silent" boot where a splash screen is
2099 loaded very quickly after power-on.
2101 CONFIG_SPLASHIMAGE_GUARD
2103 If this option is set, then U-Boot will prevent the environment
2104 variable "splashimage" from being set to a problematic address
2105 (see README.displaying-bmps).
2106 This option is useful for targets where, due to alignment
2107 restrictions, an improperly aligned BMP image will cause a data
2108 abort. If you think you will not have problems with unaligned
2109 accesses (for example because your toolchain prevents them)
2110 there is no need to set this option.
2112 CONFIG_SPLASH_SCREEN_ALIGN
2114 If this option is set the splash image can be freely positioned
2115 on the screen. Environment variable "splashpos" specifies the
2116 position as "x,y". If a positive number is given it is used as
2117 number of pixel from left/top. If a negative number is given it
2118 is used as number of pixel from right/bottom. You can also
2119 specify 'm' for centering the image.
2122 setenv splashpos m,m
2123 => image at center of screen
2125 setenv splashpos 30,20
2126 => image at x = 30 and y = 20
2128 setenv splashpos -10,m
2129 => vertically centered image
2130 at x = dspWidth - bmpWidth - 9
2132 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2134 If this option is set, additionally to standard BMP
2135 images, gzipped BMP images can be displayed via the
2136 splashscreen support or the bmp command.
2138 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2140 If this option is set, 8-bit RLE compressed BMP images
2141 can be displayed via the splashscreen support or the
2144 - Do compressing for memory range:
2147 If this option is set, it would use zlib deflate method
2148 to compress the specified memory at its best effort.
2150 - Compression support:
2153 Enabled by default to support gzip compressed images.
2157 If this option is set, support for bzip2 compressed
2158 images is included. If not, only uncompressed and gzip
2159 compressed images are supported.
2161 NOTE: the bzip2 algorithm requires a lot of RAM, so
2162 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2167 If this option is set, support for lzma compressed
2170 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2171 requires an amount of dynamic memory that is given by the
2174 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2176 Where lc and lp stand for, respectively, Literal context bits
2177 and Literal pos bits.
2179 This value is upper-bounded by 14MB in the worst case. Anyway,
2180 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2181 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2182 a very small buffer.
2184 Use the lzmainfo tool to determinate the lc and lp values and
2185 then calculate the amount of needed dynamic memory (ensuring
2186 the appropriate CONFIG_SYS_MALLOC_LEN value).
2190 If this option is set, support for LZO compressed images
2196 The address of PHY on MII bus.
2198 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2200 The clock frequency of the MII bus
2204 If this option is set, support for speed/duplex
2205 detection of gigabit PHY is included.
2207 CONFIG_PHY_RESET_DELAY
2209 Some PHY like Intel LXT971A need extra delay after
2210 reset before any MII register access is possible.
2211 For such PHY, set this option to the usec delay
2212 required. (minimum 300usec for LXT971A)
2214 CONFIG_PHY_CMD_DELAY (ppc4xx)
2216 Some PHY like Intel LXT971A need extra delay after
2217 command issued before MII status register can be read
2222 Define a default value for the IP address to use for
2223 the default Ethernet interface, in case this is not
2224 determined through e.g. bootp.
2225 (Environment variable "ipaddr")
2227 - Server IP address:
2230 Defines a default value for the IP address of a TFTP
2231 server to contact when using the "tftboot" command.
2232 (Environment variable "serverip")
2234 CONFIG_KEEP_SERVERADDR
2236 Keeps the server's MAC address, in the env 'serveraddr'
2237 for passing to bootargs (like Linux's netconsole option)
2239 - Gateway IP address:
2242 Defines a default value for the IP address of the
2243 default router where packets to other networks are
2245 (Environment variable "gatewayip")
2250 Defines a default value for the subnet mask (or
2251 routing prefix) which is used to determine if an IP
2252 address belongs to the local subnet or needs to be
2253 forwarded through a router.
2254 (Environment variable "netmask")
2256 - Multicast TFTP Mode:
2259 Defines whether you want to support multicast TFTP as per
2260 rfc-2090; for example to work with atftp. Lets lots of targets
2261 tftp down the same boot image concurrently. Note: the Ethernet
2262 driver in use must provide a function: mcast() to join/leave a
2265 - BOOTP Recovery Mode:
2266 CONFIG_BOOTP_RANDOM_DELAY
2268 If you have many targets in a network that try to
2269 boot using BOOTP, you may want to avoid that all
2270 systems send out BOOTP requests at precisely the same
2271 moment (which would happen for instance at recovery
2272 from a power failure, when all systems will try to
2273 boot, thus flooding the BOOTP server. Defining
2274 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2275 inserted before sending out BOOTP requests. The
2276 following delays are inserted then:
2278 1st BOOTP request: delay 0 ... 1 sec
2279 2nd BOOTP request: delay 0 ... 2 sec
2280 3rd BOOTP request: delay 0 ... 4 sec
2282 BOOTP requests: delay 0 ... 8 sec
2284 CONFIG_BOOTP_ID_CACHE_SIZE
2286 BOOTP packets are uniquely identified using a 32-bit ID. The
2287 server will copy the ID from client requests to responses and
2288 U-Boot will use this to determine if it is the destination of
2289 an incoming response. Some servers will check that addresses
2290 aren't in use before handing them out (usually using an ARP
2291 ping) and therefore take up to a few hundred milliseconds to
2292 respond. Network congestion may also influence the time it
2293 takes for a response to make it back to the client. If that
2294 time is too long, U-Boot will retransmit requests. In order
2295 to allow earlier responses to still be accepted after these
2296 retransmissions, U-Boot's BOOTP client keeps a small cache of
2297 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2298 cache. The default is to keep IDs for up to four outstanding
2299 requests. Increasing this will allow U-Boot to accept offers
2300 from a BOOTP client in networks with unusually high latency.
2302 - BOOTP Random transaction ID:
2303 CONFIG_BOOTP_RANDOM_ID
2305 The standard algorithm to generate a DHCP/BOOTP transaction ID
2306 by using the MAC address and the current time stamp may not
2307 quite unlikely produce duplicate transaction IDs from different
2308 clients in the same network. This option creates a transaction
2309 ID using the rand() function. Provided that the RNG has been
2310 seeded well, this should guarantee unique transaction IDs
2313 - DHCP Advanced Options:
2314 You can fine tune the DHCP functionality by defining
2315 CONFIG_BOOTP_* symbols:
2317 CONFIG_BOOTP_SUBNETMASK
2318 CONFIG_BOOTP_GATEWAY
2319 CONFIG_BOOTP_HOSTNAME
2320 CONFIG_BOOTP_NISDOMAIN
2321 CONFIG_BOOTP_BOOTPATH
2322 CONFIG_BOOTP_BOOTFILESIZE
2325 CONFIG_BOOTP_SEND_HOSTNAME
2326 CONFIG_BOOTP_NTPSERVER
2327 CONFIG_BOOTP_TIMEOFFSET
2328 CONFIG_BOOTP_VENDOREX
2329 CONFIG_BOOTP_MAY_FAIL
2331 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2332 environment variable, not the BOOTP server.
2334 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2335 after the configured retry count, the call will fail
2336 instead of starting over. This can be used to fail over
2337 to Link-local IP address configuration if the DHCP server
2340 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2341 serverip from a DHCP server, it is possible that more
2342 than one DNS serverip is offered to the client.
2343 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2344 serverip will be stored in the additional environment
2345 variable "dnsip2". The first DNS serverip is always
2346 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2349 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2350 to do a dynamic update of a DNS server. To do this, they
2351 need the hostname of the DHCP requester.
2352 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2353 of the "hostname" environment variable is passed as
2354 option 12 to the DHCP server.
2356 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2358 A 32bit value in microseconds for a delay between
2359 receiving a "DHCP Offer" and sending the "DHCP Request".
2360 This fixes a problem with certain DHCP servers that don't
2361 respond 100% of the time to a "DHCP request". E.g. On an
2362 AT91RM9200 processor running at 180MHz, this delay needed
2363 to be *at least* 15,000 usec before a Windows Server 2003
2364 DHCP server would reply 100% of the time. I recommend at
2365 least 50,000 usec to be safe. The alternative is to hope
2366 that one of the retries will be successful but note that
2367 the DHCP timeout and retry process takes a longer than
2370 - Link-local IP address negotiation:
2371 Negotiate with other link-local clients on the local network
2372 for an address that doesn't require explicit configuration.
2373 This is especially useful if a DHCP server cannot be guaranteed
2374 to exist in all environments that the device must operate.
2376 See doc/README.link-local for more information.
2379 CONFIG_CDP_DEVICE_ID
2381 The device id used in CDP trigger frames.
2383 CONFIG_CDP_DEVICE_ID_PREFIX
2385 A two character string which is prefixed to the MAC address
2390 A printf format string which contains the ascii name of
2391 the port. Normally is set to "eth%d" which sets
2392 eth0 for the first Ethernet, eth1 for the second etc.
2394 CONFIG_CDP_CAPABILITIES
2396 A 32bit integer which indicates the device capabilities;
2397 0x00000010 for a normal host which does not forwards.
2401 An ascii string containing the version of the software.
2405 An ascii string containing the name of the platform.
2409 A 32bit integer sent on the trigger.
2411 CONFIG_CDP_POWER_CONSUMPTION
2413 A 16bit integer containing the power consumption of the
2414 device in .1 of milliwatts.
2416 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2418 A byte containing the id of the VLAN.
2420 - Status LED: CONFIG_STATUS_LED
2422 Several configurations allow to display the current
2423 status using a LED. For instance, the LED will blink
2424 fast while running U-Boot code, stop blinking as
2425 soon as a reply to a BOOTP request was received, and
2426 start blinking slow once the Linux kernel is running
2427 (supported by a status LED driver in the Linux
2428 kernel). Defining CONFIG_STATUS_LED enables this
2434 The status LED can be connected to a GPIO pin.
2435 In such cases, the gpio_led driver can be used as a
2436 status LED backend implementation. Define CONFIG_GPIO_LED
2437 to include the gpio_led driver in the U-Boot binary.
2439 CONFIG_GPIO_LED_INVERTED_TABLE
2440 Some GPIO connected LEDs may have inverted polarity in which
2441 case the GPIO high value corresponds to LED off state and
2442 GPIO low value corresponds to LED on state.
2443 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2444 with a list of GPIO LEDs that have inverted polarity.
2446 - CAN Support: CONFIG_CAN_DRIVER
2448 Defining CONFIG_CAN_DRIVER enables CAN driver support
2449 on those systems that support this (optional)
2450 feature, like the TQM8xxL modules.
2452 - I2C Support: CONFIG_SYS_I2C
2454 This enable the NEW i2c subsystem, and will allow you to use
2455 i2c commands at the u-boot command line (as long as you set
2456 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2457 based realtime clock chips or other i2c devices. See
2458 common/cmd_i2c.c for a description of the command line
2461 ported i2c driver to the new framework:
2462 - drivers/i2c/soft_i2c.c:
2463 - activate first bus with CONFIG_SYS_I2C_SOFT define
2464 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2465 for defining speed and slave address
2466 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2467 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2468 for defining speed and slave address
2469 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2470 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2471 for defining speed and slave address
2472 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2473 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2474 for defining speed and slave address
2476 - drivers/i2c/fsl_i2c.c:
2477 - activate i2c driver with CONFIG_SYS_I2C_FSL
2478 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2479 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2480 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2482 - If your board supports a second fsl i2c bus, define
2483 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2484 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2485 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2488 - drivers/i2c/tegra_i2c.c:
2489 - activate this driver with CONFIG_SYS_I2C_TEGRA
2490 - This driver adds 4 i2c buses with a fix speed from
2491 100000 and the slave addr 0!
2493 - drivers/i2c/ppc4xx_i2c.c
2494 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2495 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2496 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2498 - drivers/i2c/i2c_mxc.c
2499 - activate this driver with CONFIG_SYS_I2C_MXC
2500 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2501 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2502 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2503 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2504 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2505 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2506 If those defines are not set, default value is 100000
2507 for speed, and 0 for slave.
2508 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2509 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2511 - drivers/i2c/rcar_i2c.c:
2512 - activate this driver with CONFIG_SYS_I2C_RCAR
2513 - This driver adds 4 i2c buses
2515 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2516 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2517 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2518 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2519 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2520 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2521 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2522 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2523 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2525 - drivers/i2c/sh_i2c.c:
2526 - activate this driver with CONFIG_SYS_I2C_SH
2527 - This driver adds from 2 to 5 i2c buses
2529 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2530 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2531 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2532 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2533 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2534 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2535 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2536 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2537 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2538 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2539 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2540 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2541 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2543 - drivers/i2c/omap24xx_i2c.c
2544 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2545 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2546 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2547 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2548 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2549 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2550 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2551 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2552 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2553 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2554 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2556 - drivers/i2c/zynq_i2c.c
2557 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2558 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2559 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2561 - drivers/i2c/s3c24x0_i2c.c:
2562 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2563 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2564 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2565 with a fix speed from 100000 and the slave addr 0!
2567 - drivers/i2c/ihs_i2c.c
2568 - activate this driver with CONFIG_SYS_I2C_IHS
2569 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2570 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2571 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2572 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2573 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2574 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2575 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2576 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2577 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2578 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2579 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2580 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2584 CONFIG_SYS_NUM_I2C_BUSES
2585 Hold the number of i2c buses you want to use. If you
2586 don't use/have i2c muxes on your i2c bus, this
2587 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2590 CONFIG_SYS_I2C_DIRECT_BUS
2591 define this, if you don't use i2c muxes on your hardware.
2592 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2595 CONFIG_SYS_I2C_MAX_HOPS
2596 define how many muxes are maximal consecutively connected
2597 on one i2c bus. If you not use i2c muxes, omit this
2600 CONFIG_SYS_I2C_BUSES
2601 hold a list of buses you want to use, only used if
2602 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2603 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2604 CONFIG_SYS_NUM_I2C_BUSES = 9:
2606 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2607 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2608 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2609 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2610 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2612 {1, {I2C_NULL_HOP}}, \
2613 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2614 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2618 bus 0 on adapter 0 without a mux
2619 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2620 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2621 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2622 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2623 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2624 bus 6 on adapter 1 without a mux
2625 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2626 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2628 If you do not have i2c muxes on your board, omit this define.
2630 - Legacy I2C Support: CONFIG_HARD_I2C
2632 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2633 provides the following compelling advantages:
2635 - more than one i2c adapter is usable
2636 - approved multibus support
2637 - better i2c mux support
2639 ** Please consider updating your I2C driver now. **
2641 These enable legacy I2C serial bus commands. Defining
2642 CONFIG_HARD_I2C will include the appropriate I2C driver
2643 for the selected CPU.
2645 This will allow you to use i2c commands at the u-boot
2646 command line (as long as you set CONFIG_CMD_I2C in
2647 CONFIG_COMMANDS) and communicate with i2c based realtime
2648 clock chips. See common/cmd_i2c.c for a description of the
2649 command line interface.
2651 CONFIG_HARD_I2C selects a hardware I2C controller.
2653 There are several other quantities that must also be
2654 defined when you define CONFIG_HARD_I2C.
2656 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2657 to be the frequency (in Hz) at which you wish your i2c bus
2658 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2659 the CPU's i2c node address).
2661 Now, the u-boot i2c code for the mpc8xx
2662 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2663 and so its address should therefore be cleared to 0 (See,
2664 eg, MPC823e User's Manual p.16-473). So, set
2665 CONFIG_SYS_I2C_SLAVE to 0.
2667 CONFIG_SYS_I2C_INIT_MPC5XXX
2669 When a board is reset during an i2c bus transfer
2670 chips might think that the current transfer is still
2671 in progress. Reset the slave devices by sending start
2672 commands until the slave device responds.
2674 That's all that's required for CONFIG_HARD_I2C.
2676 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2677 then the following macros need to be defined (examples are
2678 from include/configs/lwmon.h):
2682 (Optional). Any commands necessary to enable the I2C
2683 controller or configure ports.
2685 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2689 (Only for MPC8260 CPU). The I/O port to use (the code
2690 assumes both bits are on the same port). Valid values
2691 are 0..3 for ports A..D.
2695 The code necessary to make the I2C data line active
2696 (driven). If the data line is open collector, this
2699 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2703 The code necessary to make the I2C data line tri-stated
2704 (inactive). If the data line is open collector, this
2707 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2711 Code that returns true if the I2C data line is high,
2714 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2718 If <bit> is true, sets the I2C data line high. If it
2719 is false, it clears it (low).
2721 eg: #define I2C_SDA(bit) \
2722 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2723 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2727 If <bit> is true, sets the I2C clock line high. If it
2728 is false, it clears it (low).
2730 eg: #define I2C_SCL(bit) \
2731 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2732 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2736 This delay is invoked four times per clock cycle so this
2737 controls the rate of data transfer. The data rate thus
2738 is 1 / (I2C_DELAY * 4). Often defined to be something
2741 #define I2C_DELAY udelay(2)
2743 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2745 If your arch supports the generic GPIO framework (asm/gpio.h),
2746 then you may alternatively define the two GPIOs that are to be
2747 used as SCL / SDA. Any of the previous I2C_xxx macros will
2748 have GPIO-based defaults assigned to them as appropriate.
2750 You should define these to the GPIO value as given directly to
2751 the generic GPIO functions.
2753 CONFIG_SYS_I2C_INIT_BOARD
2755 When a board is reset during an i2c bus transfer
2756 chips might think that the current transfer is still
2757 in progress. On some boards it is possible to access
2758 the i2c SCLK line directly, either by using the
2759 processor pin as a GPIO or by having a second pin
2760 connected to the bus. If this option is defined a
2761 custom i2c_init_board() routine in boards/xxx/board.c
2762 is run early in the boot sequence.
2764 CONFIG_SYS_I2C_BOARD_LATE_INIT
2766 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2767 defined a custom i2c_board_late_init() routine in
2768 boards/xxx/board.c is run AFTER the operations in i2c_init()
2769 is completed. This callpoint can be used to unreset i2c bus
2770 using CPU i2c controller register accesses for CPUs whose i2c
2771 controller provide such a method. It is called at the end of
2772 i2c_init() to allow i2c_init operations to setup the i2c bus
2773 controller on the CPU (e.g. setting bus speed & slave address).
2775 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2777 This option enables configuration of bi_iic_fast[] flags
2778 in u-boot bd_info structure based on u-boot environment
2779 variable "i2cfast". (see also i2cfast)
2781 CONFIG_I2C_MULTI_BUS
2783 This option allows the use of multiple I2C buses, each of which
2784 must have a controller. At any point in time, only one bus is
2785 active. To switch to a different bus, use the 'i2c dev' command.
2786 Note that bus numbering is zero-based.
2788 CONFIG_SYS_I2C_NOPROBES
2790 This option specifies a list of I2C devices that will be skipped
2791 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2792 is set, specify a list of bus-device pairs. Otherwise, specify
2793 a 1D array of device addresses
2796 #undef CONFIG_I2C_MULTI_BUS
2797 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2799 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2801 #define CONFIG_I2C_MULTI_BUS
2802 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2804 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2806 CONFIG_SYS_SPD_BUS_NUM
2808 If defined, then this indicates the I2C bus number for DDR SPD.
2809 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2811 CONFIG_SYS_RTC_BUS_NUM
2813 If defined, then this indicates the I2C bus number for the RTC.
2814 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2816 CONFIG_SYS_DTT_BUS_NUM
2818 If defined, then this indicates the I2C bus number for the DTT.
2819 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2821 CONFIG_SYS_I2C_DTT_ADDR:
2823 If defined, specifies the I2C address of the DTT device.
2824 If not defined, then U-Boot uses predefined value for
2825 specified DTT device.
2827 CONFIG_SOFT_I2C_READ_REPEATED_START
2829 defining this will force the i2c_read() function in
2830 the soft_i2c driver to perform an I2C repeated start
2831 between writing the address pointer and reading the
2832 data. If this define is omitted the default behaviour
2833 of doing a stop-start sequence will be used. Most I2C
2834 devices can use either method, but some require one or
2837 - SPI Support: CONFIG_SPI
2839 Enables SPI driver (so far only tested with
2840 SPI EEPROM, also an instance works with Crystal A/D and
2841 D/As on the SACSng board)
2845 Enables the driver for SPI controller on SuperH. Currently
2846 only SH7757 is supported.
2850 Enables extended (16-bit) SPI EEPROM addressing.
2851 (symmetrical to CONFIG_I2C_X)
2855 Enables a software (bit-bang) SPI driver rather than
2856 using hardware support. This is a general purpose
2857 driver that only requires three general I/O port pins
2858 (two outputs, one input) to function. If this is
2859 defined, the board configuration must define several
2860 SPI configuration items (port pins to use, etc). For
2861 an example, see include/configs/sacsng.h.
2865 Enables a hardware SPI driver for general-purpose reads
2866 and writes. As with CONFIG_SOFT_SPI, the board configuration
2867 must define a list of chip-select function pointers.
2868 Currently supported on some MPC8xxx processors. For an
2869 example, see include/configs/mpc8349emds.h.
2873 Enables the driver for the SPI controllers on i.MX and MXC
2874 SoCs. Currently i.MX31/35/51 are supported.
2876 CONFIG_SYS_SPI_MXC_WAIT
2877 Timeout for waiting until spi transfer completed.
2878 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2880 - FPGA Support: CONFIG_FPGA
2882 Enables FPGA subsystem.
2884 CONFIG_FPGA_<vendor>
2886 Enables support for specific chip vendors.
2889 CONFIG_FPGA_<family>
2891 Enables support for FPGA family.
2892 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2896 Specify the number of FPGA devices to support.
2898 CONFIG_CMD_FPGA_LOADMK
2900 Enable support for fpga loadmk command
2902 CONFIG_CMD_FPGA_LOADP
2904 Enable support for fpga loadp command - load partial bitstream
2906 CONFIG_CMD_FPGA_LOADBP
2908 Enable support for fpga loadbp command - load partial bitstream
2911 CONFIG_SYS_FPGA_PROG_FEEDBACK
2913 Enable printing of hash marks during FPGA configuration.
2915 CONFIG_SYS_FPGA_CHECK_BUSY
2917 Enable checks on FPGA configuration interface busy
2918 status by the configuration function. This option
2919 will require a board or device specific function to
2924 If defined, a function that provides delays in the FPGA
2925 configuration driver.
2927 CONFIG_SYS_FPGA_CHECK_CTRLC
2928 Allow Control-C to interrupt FPGA configuration
2930 CONFIG_SYS_FPGA_CHECK_ERROR
2932 Check for configuration errors during FPGA bitfile
2933 loading. For example, abort during Virtex II
2934 configuration if the INIT_B line goes low (which
2935 indicated a CRC error).
2937 CONFIG_SYS_FPGA_WAIT_INIT
2939 Maximum time to wait for the INIT_B line to de-assert
2940 after PROB_B has been de-asserted during a Virtex II
2941 FPGA configuration sequence. The default time is 500
2944 CONFIG_SYS_FPGA_WAIT_BUSY
2946 Maximum time to wait for BUSY to de-assert during
2947 Virtex II FPGA configuration. The default is 5 ms.
2949 CONFIG_SYS_FPGA_WAIT_CONFIG
2951 Time to wait after FPGA configuration. The default is
2954 - Configuration Management:
2957 Some SoCs need special image types (e.g. U-Boot binary
2958 with a special header) as build targets. By defining
2959 CONFIG_BUILD_TARGET in the SoC / board header, this
2960 special image will be automatically built upon calling
2965 If defined, this string will be added to the U-Boot
2966 version information (U_BOOT_VERSION)
2968 - Vendor Parameter Protection:
2970 U-Boot considers the values of the environment
2971 variables "serial#" (Board Serial Number) and
2972 "ethaddr" (Ethernet Address) to be parameters that
2973 are set once by the board vendor / manufacturer, and
2974 protects these variables from casual modification by
2975 the user. Once set, these variables are read-only,
2976 and write or delete attempts are rejected. You can
2977 change this behaviour:
2979 If CONFIG_ENV_OVERWRITE is #defined in your config
2980 file, the write protection for vendor parameters is
2981 completely disabled. Anybody can change or delete
2984 Alternatively, if you define _both_ an ethaddr in the
2985 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2986 Ethernet address is installed in the environment,
2987 which can be changed exactly ONCE by the user. [The
2988 serial# is unaffected by this, i. e. it remains
2991 The same can be accomplished in a more flexible way
2992 for any variable by configuring the type of access
2993 to allow for those variables in the ".flags" variable
2994 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2999 Define this variable to enable the reservation of
3000 "protected RAM", i. e. RAM which is not overwritten
3001 by U-Boot. Define CONFIG_PRAM to hold the number of
3002 kB you want to reserve for pRAM. You can overwrite
3003 this default value by defining an environment
3004 variable "pram" to the number of kB you want to
3005 reserve. Note that the board info structure will
3006 still show the full amount of RAM. If pRAM is
3007 reserved, a new environment variable "mem" will
3008 automatically be defined to hold the amount of
3009 remaining RAM in a form that can be passed as boot
3010 argument to Linux, for instance like that:
3012 setenv bootargs ... mem=\${mem}
3015 This way you can tell Linux not to use this memory,
3016 either, which results in a memory region that will
3017 not be affected by reboots.
3019 *WARNING* If your board configuration uses automatic
3020 detection of the RAM size, you must make sure that
3021 this memory test is non-destructive. So far, the
3022 following board configurations are known to be
3025 IVMS8, IVML24, SPD8xx, TQM8xxL,
3026 HERMES, IP860, RPXlite, LWMON,
3029 - Access to physical memory region (> 4GB)
3030 Some basic support is provided for operations on memory not
3031 normally accessible to U-Boot - e.g. some architectures
3032 support access to more than 4GB of memory on 32-bit
3033 machines using physical address extension or similar.
3034 Define CONFIG_PHYSMEM to access this basic support, which
3035 currently only supports clearing the memory.
3040 Define this variable to stop the system in case of a
3041 fatal error, so that you have to reset it manually.
3042 This is probably NOT a good idea for an embedded
3043 system where you want the system to reboot
3044 automatically as fast as possible, but it may be
3045 useful during development since you can try to debug
3046 the conditions that lead to the situation.
3048 CONFIG_NET_RETRY_COUNT
3050 This variable defines the number of retries for
3051 network operations like ARP, RARP, TFTP, or BOOTP
3052 before giving up the operation. If not defined, a
3053 default value of 5 is used.
3057 Timeout waiting for an ARP reply in milliseconds.
3061 Timeout in milliseconds used in NFS protocol.
3062 If you encounter "ERROR: Cannot umount" in nfs command,
3063 try longer timeout such as
3064 #define CONFIG_NFS_TIMEOUT 10000UL
3066 - Command Interpreter:
3067 CONFIG_AUTO_COMPLETE
3069 Enable auto completion of commands using TAB.
3071 CONFIG_SYS_PROMPT_HUSH_PS2
3073 This defines the secondary prompt string, which is
3074 printed when the command interpreter needs more input
3075 to complete a command. Usually "> ".
3079 In the current implementation, the local variables
3080 space and global environment variables space are
3081 separated. Local variables are those you define by
3082 simply typing `name=value'. To access a local
3083 variable later on, you have write `$name' or
3084 `${name}'; to execute the contents of a variable
3085 directly type `$name' at the command prompt.
3087 Global environment variables are those you use
3088 setenv/printenv to work with. To run a command stored
3089 in such a variable, you need to use the run command,
3090 and you must not use the '$' sign to access them.
3092 To store commands and special characters in a
3093 variable, please use double quotation marks
3094 surrounding the whole text of the variable, instead
3095 of the backslashes before semicolons and special
3098 - Command Line Editing and History:
3099 CONFIG_CMDLINE_EDITING
3101 Enable editing and History functions for interactive
3102 command line input operations
3104 - Default Environment:
3105 CONFIG_EXTRA_ENV_SETTINGS
3107 Define this to contain any number of null terminated
3108 strings (variable = value pairs) that will be part of
3109 the default environment compiled into the boot image.
3111 For example, place something like this in your
3112 board's config file:
3114 #define CONFIG_EXTRA_ENV_SETTINGS \
3118 Warning: This method is based on knowledge about the
3119 internal format how the environment is stored by the
3120 U-Boot code. This is NOT an official, exported
3121 interface! Although it is unlikely that this format
3122 will change soon, there is no guarantee either.
3123 You better know what you are doing here.
3125 Note: overly (ab)use of the default environment is
3126 discouraged. Make sure to check other ways to preset
3127 the environment like the "source" command or the
3130 CONFIG_ENV_VARS_UBOOT_CONFIG
3132 Define this in order to add variables describing the
3133 U-Boot build configuration to the default environment.
3134 These will be named arch, cpu, board, vendor, and soc.
3136 Enabling this option will cause the following to be defined:
3144 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3146 Define this in order to add variables describing certain
3147 run-time determined information about the hardware to the
3148 environment. These will be named board_name, board_rev.
3150 CONFIG_DELAY_ENVIRONMENT
3152 Normally the environment is loaded when the board is
3153 initialised so that it is available to U-Boot. This inhibits
3154 that so that the environment is not available until
3155 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3156 this is instead controlled by the value of
3157 /config/load-environment.
3159 - Parallel Flash support:
3162 Traditionally U-boot was run on systems with parallel NOR
3163 flash. This option is used to disable support for parallel NOR
3164 flash. This option should be defined if the board does not have
3167 If this option is not defined one of the generic flash drivers
3168 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3169 selected or the board must provide an implementation of the
3170 flash API (see include/flash.h).
3172 - DataFlash Support:
3173 CONFIG_HAS_DATAFLASH
3175 Defining this option enables DataFlash features and
3176 allows to read/write in Dataflash via the standard
3179 - Serial Flash support
3182 Defining this option enables SPI flash commands
3183 'sf probe/read/write/erase/update'.
3185 Usage requires an initial 'probe' to define the serial
3186 flash parameters, followed by read/write/erase/update
3189 The following defaults may be provided by the platform
3190 to handle the common case when only a single serial
3191 flash is present on the system.
3193 CONFIG_SF_DEFAULT_BUS Bus identifier
3194 CONFIG_SF_DEFAULT_CS Chip-select
3195 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3196 CONFIG_SF_DEFAULT_SPEED in Hz
3200 Define this option to include a destructive SPI flash
3203 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3205 Define this option to use the Bank addr/Extended addr
3206 support on SPI flashes which has size > 16Mbytes.
3208 CONFIG_SF_DUAL_FLASH Dual flash memories
3210 Define this option to use dual flash support where two flash
3211 memories can be connected with a given cs line.
3212 Currently Xilinx Zynq qspi supports these type of connections.
3214 - SystemACE Support:
3217 Adding this option adds support for Xilinx SystemACE
3218 chips attached via some sort of local bus. The address
3219 of the chip must also be defined in the
3220 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3222 #define CONFIG_SYSTEMACE
3223 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3225 When SystemACE support is added, the "ace" device type
3226 becomes available to the fat commands, i.e. fatls.
3228 - TFTP Fixed UDP Port:
3231 If this is defined, the environment variable tftpsrcp
3232 is used to supply the TFTP UDP source port value.
3233 If tftpsrcp isn't defined, the normal pseudo-random port
3234 number generator is used.
3236 Also, the environment variable tftpdstp is used to supply
3237 the TFTP UDP destination port value. If tftpdstp isn't
3238 defined, the normal port 69 is used.
3240 The purpose for tftpsrcp is to allow a TFTP server to
3241 blindly start the TFTP transfer using the pre-configured
3242 target IP address and UDP port. This has the effect of
3243 "punching through" the (Windows XP) firewall, allowing
3244 the remainder of the TFTP transfer to proceed normally.
3245 A better solution is to properly configure the firewall,
3246 but sometimes that is not allowed.
3251 This enables a generic 'hash' command which can produce
3252 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3256 Enable the hash verify command (hash -v). This adds to code
3259 CONFIG_SHA1 - This option enables support of hashing using SHA1
3260 algorithm. The hash is calculated in software.
3261 CONFIG_SHA256 - This option enables support of hashing using
3262 SHA256 algorithm. The hash is calculated in software.
3263 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3264 for SHA1/SHA256 hashing.
3265 This affects the 'hash' command and also the
3266 hash_lookup_algo() function.
3267 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3268 hardware-acceleration for SHA1/SHA256 progressive hashing.
3269 Data can be streamed in a block at a time and the hashing
3270 is performed in hardware.
3272 Note: There is also a sha1sum command, which should perhaps
3273 be deprecated in favour of 'hash sha1'.
3275 - Freescale i.MX specific commands:
3276 CONFIG_CMD_HDMIDETECT
3277 This enables 'hdmidet' command which returns true if an
3278 HDMI monitor is detected. This command is i.MX 6 specific.
3281 This enables the 'bmode' (bootmode) command for forcing
3282 a boot from specific media.
3284 This is useful for forcing the ROM's usb downloader to
3285 activate upon a watchdog reset which is nice when iterating
3286 on U-Boot. Using the reset button or running bmode normal
3287 will set it back to normal. This command currently
3288 supports i.MX53 and i.MX6.
3293 This enables the RSA algorithm used for FIT image verification
3294 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3296 The Modular Exponentiation algorithm in RSA is implemented using
3297 driver model. So CONFIG_DM needs to be enabled by default for this
3298 library to function.
3300 The signing part is build into mkimage regardless of this
3301 option. The software based modular exponentiation is built into
3302 mkimage irrespective of this option.
3304 - bootcount support:
3305 CONFIG_BOOTCOUNT_LIMIT
3307 This enables the bootcounter support, see:
3308 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3311 enable special bootcounter support on at91sam9xe based boards.
3313 enable special bootcounter support on blackfin based boards.
3315 enable special bootcounter support on da850 based boards.
3316 CONFIG_BOOTCOUNT_RAM
3317 enable support for the bootcounter in RAM
3318 CONFIG_BOOTCOUNT_I2C
3319 enable support for the bootcounter on an i2c (like RTC) device.
3320 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3321 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3323 CONFIG_BOOTCOUNT_ALEN = address len
3325 - Show boot progress:
3326 CONFIG_SHOW_BOOT_PROGRESS
3328 Defining this option allows to add some board-
3329 specific code (calling a user-provided function
3330 "show_boot_progress(int)") that enables you to show
3331 the system's boot progress on some display (for
3332 example, some LED's) on your board. At the moment,
3333 the following checkpoints are implemented:
3336 Legacy uImage format:
3339 1 common/cmd_bootm.c before attempting to boot an image
3340 -1 common/cmd_bootm.c Image header has bad magic number
3341 2 common/cmd_bootm.c Image header has correct magic number
3342 -2 common/cmd_bootm.c Image header has bad checksum
3343 3 common/cmd_bootm.c Image header has correct checksum
3344 -3 common/cmd_bootm.c Image data has bad checksum
3345 4 common/cmd_bootm.c Image data has correct checksum
3346 -4 common/cmd_bootm.c Image is for unsupported architecture
3347 5 common/cmd_bootm.c Architecture check OK
3348 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3349 6 common/cmd_bootm.c Image Type check OK
3350 -6 common/cmd_bootm.c gunzip uncompression error
3351 -7 common/cmd_bootm.c Unimplemented compression type
3352 7 common/cmd_bootm.c Uncompression OK
3353 8 common/cmd_bootm.c No uncompress/copy overwrite error
3354 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3356 9 common/image.c Start initial ramdisk verification
3357 -10 common/image.c Ramdisk header has bad magic number
3358 -11 common/image.c Ramdisk header has bad checksum
3359 10 common/image.c Ramdisk header is OK
3360 -12 common/image.c Ramdisk data has bad checksum
3361 11 common/image.c Ramdisk data has correct checksum
3362 12 common/image.c Ramdisk verification complete, start loading
3363 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3364 13 common/image.c Start multifile image verification
3365 14 common/image.c No initial ramdisk, no multifile, continue.
3367 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3369 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3370 -31 post/post.c POST test failed, detected by post_output_backlog()
3371 -32 post/post.c POST test failed, detected by post_run_single()
3373 34 common/cmd_doc.c before loading a Image from a DOC device
3374 -35 common/cmd_doc.c Bad usage of "doc" command
3375 35 common/cmd_doc.c correct usage of "doc" command
3376 -36 common/cmd_doc.c No boot device
3377 36 common/cmd_doc.c correct boot device
3378 -37 common/cmd_doc.c Unknown Chip ID on boot device
3379 37 common/cmd_doc.c correct chip ID found, device available
3380 -38 common/cmd_doc.c Read Error on boot device
3381 38 common/cmd_doc.c reading Image header from DOC device OK
3382 -39 common/cmd_doc.c Image header has bad magic number
3383 39 common/cmd_doc.c Image header has correct magic number
3384 -40 common/cmd_doc.c Error reading Image from DOC device
3385 40 common/cmd_doc.c Image header has correct magic number
3386 41 common/cmd_ide.c before loading a Image from a IDE device
3387 -42 common/cmd_ide.c Bad usage of "ide" command
3388 42 common/cmd_ide.c correct usage of "ide" command
3389 -43 common/cmd_ide.c No boot device
3390 43 common/cmd_ide.c boot device found
3391 -44 common/cmd_ide.c Device not available
3392 44 common/cmd_ide.c Device available
3393 -45 common/cmd_ide.c wrong partition selected
3394 45 common/cmd_ide.c partition selected
3395 -46 common/cmd_ide.c Unknown partition table
3396 46 common/cmd_ide.c valid partition table found
3397 -47 common/cmd_ide.c Invalid partition type
3398 47 common/cmd_ide.c correct partition type
3399 -48 common/cmd_ide.c Error reading Image Header on boot device
3400 48 common/cmd_ide.c reading Image Header from IDE device OK
3401 -49 common/cmd_ide.c Image header has bad magic number
3402 49 common/cmd_ide.c Image header has correct magic number
3403 -50 common/cmd_ide.c Image header has bad checksum
3404 50 common/cmd_ide.c Image header has correct checksum
3405 -51 common/cmd_ide.c Error reading Image from IDE device
3406 51 common/cmd_ide.c reading Image from IDE device OK
3407 52 common/cmd_nand.c before loading a Image from a NAND device
3408 -53 common/cmd_nand.c Bad usage of "nand" command
3409 53 common/cmd_nand.c correct usage of "nand" command
3410 -54 common/cmd_nand.c No boot device
3411 54 common/cmd_nand.c boot device found
3412 -55 common/cmd_nand.c Unknown Chip ID on boot device
3413 55 common/cmd_nand.c correct chip ID found, device available
3414 -56 common/cmd_nand.c Error reading Image Header on boot device
3415 56 common/cmd_nand.c reading Image Header from NAND device OK
3416 -57 common/cmd_nand.c Image header has bad magic number
3417 57 common/cmd_nand.c Image header has correct magic number
3418 -58 common/cmd_nand.c Error reading Image from NAND device
3419 58 common/cmd_nand.c reading Image from NAND device OK
3421 -60 common/env_common.c Environment has a bad CRC, using default
3423 64 net/eth.c starting with Ethernet configuration.
3424 -64 net/eth.c no Ethernet found.
3425 65 net/eth.c Ethernet found.
3427 -80 common/cmd_net.c usage wrong
3428 80 common/cmd_net.c before calling net_loop()
3429 -81 common/cmd_net.c some error in net_loop() occurred
3430 81 common/cmd_net.c net_loop() back without error
3431 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3432 82 common/cmd_net.c trying automatic boot
3433 83 common/cmd_net.c running "source" command
3434 -83 common/cmd_net.c some error in automatic boot or "source" command
3435 84 common/cmd_net.c end without errors
3440 100 common/cmd_bootm.c Kernel FIT Image has correct format
3441 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3442 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3443 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3444 102 common/cmd_bootm.c Kernel unit name specified
3445 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3446 103 common/cmd_bootm.c Found configuration node
3447 104 common/cmd_bootm.c Got kernel subimage node offset
3448 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3449 105 common/cmd_bootm.c Kernel subimage hash verification OK
3450 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3451 106 common/cmd_bootm.c Architecture check OK
3452 -106 common/cmd_bootm.c Kernel subimage has wrong type
3453 107 common/cmd_bootm.c Kernel subimage type OK
3454 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3455 108 common/cmd_bootm.c Got kernel subimage data/size
3456 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3457 -109 common/cmd_bootm.c Can't get kernel subimage type
3458 -110 common/cmd_bootm.c Can't get kernel subimage comp
3459 -111 common/cmd_bootm.c Can't get kernel subimage os
3460 -112 common/cmd_bootm.c Can't get kernel subimage load address
3461 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3463 120 common/image.c Start initial ramdisk verification
3464 -120 common/image.c Ramdisk FIT image has incorrect format
3465 121 common/image.c Ramdisk FIT image has correct format
3466 122 common/image.c No ramdisk subimage unit name, using configuration
3467 -122 common/image.c Can't get configuration for ramdisk subimage
3468 123 common/image.c Ramdisk unit name specified
3469 -124 common/image.c Can't get ramdisk subimage node offset
3470 125 common/image.c Got ramdisk subimage node offset
3471 -125 common/image.c Ramdisk subimage hash verification failed
3472 126 common/image.c Ramdisk subimage hash verification OK
3473 -126 common/image.c Ramdisk subimage for unsupported architecture
3474 127 common/image.c Architecture check OK
3475 -127 common/image.c Can't get ramdisk subimage data/size
3476 128 common/image.c Got ramdisk subimage data/size
3477 129 common/image.c Can't get ramdisk load address
3478 -129 common/image.c Got ramdisk load address
3480 -130 common/cmd_doc.c Incorrect FIT image format
3481 131 common/cmd_doc.c FIT image format OK
3483 -140 common/cmd_ide.c Incorrect FIT image format
3484 141 common/cmd_ide.c FIT image format OK
3486 -150 common/cmd_nand.c Incorrect FIT image format
3487 151 common/cmd_nand.c FIT image format OK
3489 - legacy image format:
3490 CONFIG_IMAGE_FORMAT_LEGACY
3491 enables the legacy image format support in U-Boot.
3494 enabled if CONFIG_FIT_SIGNATURE is not defined.
3496 CONFIG_DISABLE_IMAGE_LEGACY
3497 disable the legacy image format
3499 This define is introduced, as the legacy image format is
3500 enabled per default for backward compatibility.
3502 - FIT image support:
3504 Enable support for the FIT uImage format.
3506 CONFIG_FIT_BEST_MATCH
3507 When no configuration is explicitly selected, default to the
3508 one whose fdt's compatibility field best matches that of
3509 U-Boot itself. A match is considered "best" if it matches the
3510 most specific compatibility entry of U-Boot's fdt's root node.
3511 The order of entries in the configuration's fdt is ignored.
3513 CONFIG_FIT_SIGNATURE
3514 This option enables signature verification of FIT uImages,
3515 using a hash signed and verified using RSA. If
3516 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3517 hashing is available using hardware, RSA library will use it.
3518 See doc/uImage.FIT/signature.txt for more details.
3520 WARNING: When relying on signed FIT images with required
3521 signature check the legacy image format is default
3522 disabled. If a board need legacy image format support
3523 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3525 CONFIG_FIT_DISABLE_SHA256
3526 Supporting SHA256 hashes has quite an impact on binary size.
3527 For constrained systems sha256 hash support can be disabled
3530 - Standalone program support:
3531 CONFIG_STANDALONE_LOAD_ADDR
3533 This option defines a board specific value for the
3534 address where standalone program gets loaded, thus
3535 overwriting the architecture dependent default
3538 - Frame Buffer Address:
3541 Define CONFIG_FB_ADDR if you want to use specific
3542 address for frame buffer. This is typically the case
3543 when using a graphics controller has separate video
3544 memory. U-Boot will then place the frame buffer at
3545 the given address instead of dynamically reserving it
3546 in system RAM by calling lcd_setmem(), which grabs
3547 the memory for the frame buffer depending on the
3548 configured panel size.
3550 Please see board_init_f function.
3552 - Automatic software updates via TFTP server
3554 CONFIG_UPDATE_TFTP_CNT_MAX
3555 CONFIG_UPDATE_TFTP_MSEC_MAX
3557 These options enable and control the auto-update feature;
3558 for a more detailed description refer to doc/README.update.
3560 - MTD Support (mtdparts command, UBI support)
3563 Adds the MTD device infrastructure from the Linux kernel.
3564 Needed for mtdparts command support.
3566 CONFIG_MTD_PARTITIONS
3568 Adds the MTD partitioning infrastructure from the Linux
3569 kernel. Needed for UBI support.
3574 Adds commands for interacting with MTD partitions formatted
3575 with the UBI flash translation layer
3577 Requires also defining CONFIG_RBTREE
3579 CONFIG_UBI_SILENCE_MSG
3581 Make the verbose messages from UBI stop printing. This leaves
3582 warnings and errors enabled.
3585 CONFIG_MTD_UBI_WL_THRESHOLD
3586 This parameter defines the maximum difference between the highest
3587 erase counter value and the lowest erase counter value of eraseblocks
3588 of UBI devices. When this threshold is exceeded, UBI starts performing
3589 wear leveling by means of moving data from eraseblock with low erase
3590 counter to eraseblocks with high erase counter.
3592 The default value should be OK for SLC NAND flashes, NOR flashes and
3593 other flashes which have eraseblock life-cycle 100000 or more.
3594 However, in case of MLC NAND flashes which typically have eraseblock
3595 life-cycle less than 10000, the threshold should be lessened (e.g.,
3596 to 128 or 256, although it does not have to be power of 2).
3600 CONFIG_MTD_UBI_BEB_LIMIT
3601 This option specifies the maximum bad physical eraseblocks UBI
3602 expects on the MTD device (per 1024 eraseblocks). If the
3603 underlying flash does not admit of bad eraseblocks (e.g. NOR
3604 flash), this value is ignored.
3606 NAND datasheets often specify the minimum and maximum NVM
3607 (Number of Valid Blocks) for the flashes' endurance lifetime.
3608 The maximum expected bad eraseblocks per 1024 eraseblocks
3609 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3610 which gives 20 for most NANDs (MaxNVB is basically the total
3611 count of eraseblocks on the chip).
3613 To put it differently, if this value is 20, UBI will try to
3614 reserve about 1.9% of physical eraseblocks for bad blocks
3615 handling. And that will be 1.9% of eraseblocks on the entire
3616 NAND chip, not just the MTD partition UBI attaches. This means
3617 that if you have, say, a NAND flash chip admits maximum 40 bad
3618 eraseblocks, and it is split on two MTD partitions of the same
3619 size, UBI will reserve 40 eraseblocks when attaching a
3624 CONFIG_MTD_UBI_FASTMAP
3625 Fastmap is a mechanism which allows attaching an UBI device
3626 in nearly constant time. Instead of scanning the whole MTD device it
3627 only has to locate a checkpoint (called fastmap) on the device.
3628 The on-flash fastmap contains all information needed to attach
3629 the device. Using fastmap makes only sense on large devices where
3630 attaching by scanning takes long. UBI will not automatically install
3631 a fastmap on old images, but you can set the UBI parameter
3632 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3633 that fastmap-enabled images are still usable with UBI implementations
3634 without fastmap support. On typical flash devices the whole fastmap
3635 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3637 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3638 Set this parameter to enable fastmap automatically on images
3645 Adds commands for interacting with UBI volumes formatted as
3646 UBIFS. UBIFS is read-only in u-boot.
3648 Requires UBI support as well as CONFIG_LZO
3650 CONFIG_UBIFS_SILENCE_MSG
3652 Make the verbose messages from UBIFS stop printing. This leaves
3653 warnings and errors enabled.
3657 Enable building of SPL globally.
3660 LDSCRIPT for linking the SPL binary.
3662 CONFIG_SPL_MAX_FOOTPRINT
3663 Maximum size in memory allocated to the SPL, BSS included.
3664 When defined, the linker checks that the actual memory
3665 used by SPL from _start to __bss_end does not exceed it.
3666 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3667 must not be both defined at the same time.
3670 Maximum size of the SPL image (text, data, rodata, and
3671 linker lists sections), BSS excluded.
3672 When defined, the linker checks that the actual size does
3675 CONFIG_SPL_TEXT_BASE
3676 TEXT_BASE for linking the SPL binary.
3678 CONFIG_SPL_RELOC_TEXT_BASE
3679 Address to relocate to. If unspecified, this is equal to
3680 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3682 CONFIG_SPL_BSS_START_ADDR
3683 Link address for the BSS within the SPL binary.
3685 CONFIG_SPL_BSS_MAX_SIZE
3686 Maximum size in memory allocated to the SPL BSS.
3687 When defined, the linker checks that the actual memory used
3688 by SPL from __bss_start to __bss_end does not exceed it.
3689 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3690 must not be both defined at the same time.
3693 Adress of the start of the stack SPL will use
3695 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3696 When defined, SPL will panic() if the image it has
3697 loaded does not have a signature.
3698 Defining this is useful when code which loads images
3699 in SPL cannot guarantee that absolutely all read errors
3701 An example is the LPC32XX MLC NAND driver, which will
3702 consider that a completely unreadable NAND block is bad,
3703 and thus should be skipped silently.
3705 CONFIG_SPL_RELOC_STACK
3706 Adress of the start of the stack SPL will use after
3707 relocation. If unspecified, this is equal to
3710 CONFIG_SYS_SPL_MALLOC_START
3711 Starting address of the malloc pool used in SPL.
3713 CONFIG_SYS_SPL_MALLOC_SIZE
3714 The size of the malloc pool used in SPL.
3716 CONFIG_SPL_FRAMEWORK
3717 Enable the SPL framework under common/. This framework
3718 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3719 NAND loading of the Linux Kernel.
3722 Enable booting directly to an OS from SPL.
3723 See also: doc/README.falcon
3725 CONFIG_SPL_DISPLAY_PRINT
3726 For ARM, enable an optional function to print more information
3727 about the running system.
3729 CONFIG_SPL_INIT_MINIMAL
3730 Arch init code should be built for a very small image
3732 CONFIG_SPL_LIBCOMMON_SUPPORT
3733 Support for common/libcommon.o in SPL binary
3735 CONFIG_SPL_LIBDISK_SUPPORT
3736 Support for disk/libdisk.o in SPL binary
3738 CONFIG_SPL_I2C_SUPPORT
3739 Support for drivers/i2c/libi2c.o in SPL binary
3741 CONFIG_SPL_GPIO_SUPPORT
3742 Support for drivers/gpio/libgpio.o in SPL binary
3744 CONFIG_SPL_MMC_SUPPORT
3745 Support for drivers/mmc/libmmc.o in SPL binary
3747 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3748 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3749 Address and partition on the MMC to load U-Boot from
3750 when the MMC is being used in raw mode.
3752 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3753 Partition on the MMC to load U-Boot from when the MMC is being
3756 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3757 Sector to load kernel uImage from when MMC is being
3758 used in raw mode (for Falcon mode)
3760 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3761 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3762 Sector and number of sectors to load kernel argument
3763 parameters from when MMC is being used in raw mode
3766 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3767 Partition on the MMC to load U-Boot from when the MMC is being
3770 CONFIG_SPL_FAT_SUPPORT
3771 Support for fs/fat/libfat.o in SPL binary
3773 CONFIG_SPL_EXT_SUPPORT
3774 Support for EXT filesystem in SPL binary
3776 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3777 Filename to read to load U-Boot when reading from filesystem
3779 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3780 Filename to read to load kernel uImage when reading
3781 from filesystem (for Falcon mode)
3783 CONFIG_SPL_FS_LOAD_ARGS_NAME
3784 Filename to read to load kernel argument parameters
3785 when reading from filesystem (for Falcon mode)
3787 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3788 Set this for NAND SPL on PPC mpc83xx targets, so that
3789 start.S waits for the rest of the SPL to load before
3790 continuing (the hardware starts execution after just
3791 loading the first page rather than the full 4K).
3793 CONFIG_SPL_SKIP_RELOCATE
3794 Avoid SPL relocation
3796 CONFIG_SPL_NAND_BASE
3797 Include nand_base.c in the SPL. Requires
3798 CONFIG_SPL_NAND_DRIVERS.
3800 CONFIG_SPL_NAND_DRIVERS
3801 SPL uses normal NAND drivers, not minimal drivers.
3804 Include standard software ECC in the SPL
3806 CONFIG_SPL_NAND_SIMPLE
3807 Support for NAND boot using simple NAND drivers that
3808 expose the cmd_ctrl() interface.
3810 CONFIG_SPL_MTD_SUPPORT
3811 Support for the MTD subsystem within SPL. Useful for
3812 environment on NAND support within SPL.
3814 CONFIG_SPL_NAND_RAW_ONLY
3815 Support to boot only raw u-boot.bin images. Use this only
3816 if you need to save space.
3818 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3819 Set for the SPL on PPC mpc8xxx targets, support for
3820 drivers/ddr/fsl/libddr.o in SPL binary.
3822 CONFIG_SPL_COMMON_INIT_DDR
3823 Set for common ddr init with serial presence detect in
3826 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3827 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3828 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3829 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3830 CONFIG_SYS_NAND_ECCBYTES
3831 Defines the size and behavior of the NAND that SPL uses
3834 CONFIG_SPL_NAND_BOOT
3835 Add support NAND boot
3837 CONFIG_SYS_NAND_U_BOOT_OFFS
3838 Location in NAND to read U-Boot from
3840 CONFIG_SYS_NAND_U_BOOT_DST
3841 Location in memory to load U-Boot to
3843 CONFIG_SYS_NAND_U_BOOT_SIZE
3844 Size of image to load
3846 CONFIG_SYS_NAND_U_BOOT_START
3847 Entry point in loaded image to jump to
3849 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3850 Define this if you need to first read the OOB and then the
3851 data. This is used, for example, on davinci platforms.
3853 CONFIG_SPL_OMAP3_ID_NAND
3854 Support for an OMAP3-specific set of functions to return the
3855 ID and MFR of the first attached NAND chip, if present.
3857 CONFIG_SPL_SERIAL_SUPPORT
3858 Support for drivers/serial/libserial.o in SPL binary
3860 CONFIG_SPL_SPI_FLASH_SUPPORT
3861 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3863 CONFIG_SPL_SPI_SUPPORT
3864 Support for drivers/spi/libspi.o in SPL binary
3866 CONFIG_SPL_RAM_DEVICE
3867 Support for running image already present in ram, in SPL binary
3869 CONFIG_SPL_LIBGENERIC_SUPPORT
3870 Support for lib/libgeneric.o in SPL binary
3872 CONFIG_SPL_ENV_SUPPORT
3873 Support for the environment operating in SPL binary
3875 CONFIG_SPL_NET_SUPPORT
3876 Support for the net/libnet.o in SPL binary.
3877 It conflicts with SPL env from storage medium specified by
3878 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3881 Image offset to which the SPL should be padded before appending
3882 the SPL payload. By default, this is defined as
3883 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3884 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3885 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3888 Final target image containing SPL and payload. Some SPLs
3889 use an arch-specific makefile fragment instead, for
3890 example if more than one image needs to be produced.
3892 CONFIG_FIT_SPL_PRINT
3893 Printing information about a FIT image adds quite a bit of
3894 code to SPL. So this is normally disabled in SPL. Use this
3895 option to re-enable it. This will affect the output of the
3896 bootm command when booting a FIT image.
3900 Enable building of TPL globally.
3903 Image offset to which the TPL should be padded before appending
3904 the TPL payload. By default, this is defined as
3905 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3906 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3907 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3912 [so far only for SMDK2400 boards]
3914 - Modem support enable:
3915 CONFIG_MODEM_SUPPORT
3917 - RTS/CTS Flow control enable:
3920 - Modem debug support:
3921 CONFIG_MODEM_SUPPORT_DEBUG
3923 Enables debugging stuff (char screen[1024], dbg())
3924 for modem support. Useful only with BDI2000.
3926 - Interrupt support (PPC):
3928 There are common interrupt_init() and timer_interrupt()
3929 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3930 for CPU specific initialization. interrupt_init_cpu()
3931 should set decrementer_count to appropriate value. If
3932 CPU resets decrementer automatically after interrupt
3933 (ppc4xx) it should set decrementer_count to zero.
3934 timer_interrupt() calls timer_interrupt_cpu() for CPU
3935 specific handling. If board has watchdog / status_led
3936 / other_activity_monitor it works automatically from
3937 general timer_interrupt().
3941 In the target system modem support is enabled when a
3942 specific key (key combination) is pressed during
3943 power-on. Otherwise U-Boot will boot normally
3944 (autoboot). The key_pressed() function is called from
3945 board_init(). Currently key_pressed() is a dummy
3946 function, returning 1 and thus enabling modem
3949 If there are no modem init strings in the
3950 environment, U-Boot proceed to autoboot; the
3951 previous output (banner, info printfs) will be
3954 See also: doc/README.Modem
3956 Board initialization settings:
3957 ------------------------------
3959 During Initialization u-boot calls a number of board specific functions
3960 to allow the preparation of board specific prerequisites, e.g. pin setup
3961 before drivers are initialized. To enable these callbacks the
3962 following configuration macros have to be defined. Currently this is
3963 architecture specific, so please check arch/your_architecture/lib/board.c
3964 typically in board_init_f() and board_init_r().
3966 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3967 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3968 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3969 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3971 Configuration Settings:
3972 -----------------------
3974 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3975 Optionally it can be defined to support 64-bit memory commands.
3977 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3978 undefine this when you're short of memory.
3980 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3981 width of the commands listed in the 'help' command output.
3983 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3984 prompt for user input.
3986 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3988 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3990 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3992 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3993 the application (usually a Linux kernel) when it is
3996 - CONFIG_SYS_BAUDRATE_TABLE:
3997 List of legal baudrate settings for this board.
3999 - CONFIG_SYS_CONSOLE_INFO_QUIET
4000 Suppress display of console information at boot.
4002 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4003 If the board specific function
4004 extern int overwrite_console (void);
4005 returns 1, the stdin, stderr and stdout are switched to the
4006 serial port, else the settings in the environment are used.
4008 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4009 Enable the call to overwrite_console().
4011 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4012 Enable overwrite of previous console environment settings.
4014 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4015 Begin and End addresses of the area used by the
4018 - CONFIG_SYS_ALT_MEMTEST:
4019 Enable an alternate, more extensive memory test.
4021 - CONFIG_SYS_MEMTEST_SCRATCH:
4022 Scratch address used by the alternate memory test
4023 You only need to set this if address zero isn't writeable
4025 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4026 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4027 this specified memory area will get subtracted from the top
4028 (end) of RAM and won't get "touched" at all by U-Boot. By
4029 fixing up gd->ram_size the Linux kernel should gets passed
4030 the now "corrected" memory size and won't touch it either.
4031 This should work for arch/ppc and arch/powerpc. Only Linux
4032 board ports in arch/powerpc with bootwrapper support that
4033 recalculate the memory size from the SDRAM controller setup
4034 will have to get fixed in Linux additionally.
4036 This option can be used as a workaround for the 440EPx/GRx
4037 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4040 WARNING: Please make sure that this value is a multiple of
4041 the Linux page size (normally 4k). If this is not the case,
4042 then the end address of the Linux memory will be located at a
4043 non page size aligned address and this could cause major
4046 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4047 Enable temporary baudrate change while serial download
4049 - CONFIG_SYS_SDRAM_BASE:
4050 Physical start address of SDRAM. _Must_ be 0 here.
4052 - CONFIG_SYS_MBIO_BASE:
4053 Physical start address of Motherboard I/O (if using a
4056 - CONFIG_SYS_FLASH_BASE:
4057 Physical start address of Flash memory.
4059 - CONFIG_SYS_MONITOR_BASE:
4060 Physical start address of boot monitor code (set by
4061 make config files to be same as the text base address
4062 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4063 CONFIG_SYS_FLASH_BASE when booting from flash.
4065 - CONFIG_SYS_MONITOR_LEN:
4066 Size of memory reserved for monitor code, used to
4067 determine _at_compile_time_ (!) if the environment is
4068 embedded within the U-Boot image, or in a separate
4071 - CONFIG_SYS_MALLOC_LEN:
4072 Size of DRAM reserved for malloc() use.
4074 - CONFIG_SYS_MALLOC_F_LEN
4075 Size of the malloc() pool for use before relocation. If
4076 this is defined, then a very simple malloc() implementation
4077 will become available before relocation. The address is just
4078 below the global data, and the stack is moved down to make
4081 This feature allocates regions with increasing addresses
4082 within the region. calloc() is supported, but realloc()
4083 is not available. free() is supported but does nothing.
4084 The memory will be freed (or in fact just forgotten) when
4085 U-Boot relocates itself.
4087 Pre-relocation malloc() is only supported on ARM and sandbox
4088 at present but is fairly easy to enable for other archs.
4090 - CONFIG_SYS_MALLOC_SIMPLE
4091 Provides a simple and small malloc() and calloc() for those
4092 boards which do not use the full malloc in SPL (which is
4093 enabled with CONFIG_SYS_SPL_MALLOC_START).
4095 - CONFIG_SYS_NONCACHED_MEMORY:
4096 Size of non-cached memory area. This area of memory will be
4097 typically located right below the malloc() area and mapped
4098 uncached in the MMU. This is useful for drivers that would
4099 otherwise require a lot of explicit cache maintenance. For
4100 some drivers it's also impossible to properly maintain the
4101 cache. For example if the regions that need to be flushed
4102 are not a multiple of the cache-line size, *and* padding
4103 cannot be allocated between the regions to align them (i.e.
4104 if the HW requires a contiguous array of regions, and the
4105 size of each region is not cache-aligned), then a flush of
4106 one region may result in overwriting data that hardware has
4107 written to another region in the same cache-line. This can
4108 happen for example in network drivers where descriptors for
4109 buffers are typically smaller than the CPU cache-line (e.g.
4110 16 bytes vs. 32 or 64 bytes).
4112 Non-cached memory is only supported on 32-bit ARM at present.
4114 - CONFIG_SYS_BOOTM_LEN:
4115 Normally compressed uImages are limited to an
4116 uncompressed size of 8 MBytes. If this is not enough,
4117 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4118 to adjust this setting to your needs.
4120 - CONFIG_SYS_BOOTMAPSZ:
4121 Maximum size of memory mapped by the startup code of
4122 the Linux kernel; all data that must be processed by
4123 the Linux kernel (bd_info, boot arguments, FDT blob if
4124 used) must be put below this limit, unless "bootm_low"
4125 environment variable is defined and non-zero. In such case
4126 all data for the Linux kernel must be between "bootm_low"
4127 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4128 variable "bootm_mapsize" will override the value of
4129 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4130 then the value in "bootm_size" will be used instead.
4132 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4133 Enable initrd_high functionality. If defined then the
4134 initrd_high feature is enabled and the bootm ramdisk subcommand
4137 - CONFIG_SYS_BOOT_GET_CMDLINE:
4138 Enables allocating and saving kernel cmdline in space between
4139 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4141 - CONFIG_SYS_BOOT_GET_KBD:
4142 Enables allocating and saving a kernel copy of the bd_info in
4143 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4145 - CONFIG_SYS_MAX_FLASH_BANKS:
4146 Max number of Flash memory banks
4148 - CONFIG_SYS_MAX_FLASH_SECT:
4149 Max number of sectors on a Flash chip
4151 - CONFIG_SYS_FLASH_ERASE_TOUT:
4152 Timeout for Flash erase operations (in ms)
4154 - CONFIG_SYS_FLASH_WRITE_TOUT:
4155 Timeout for Flash write operations (in ms)
4157 - CONFIG_SYS_FLASH_LOCK_TOUT
4158 Timeout for Flash set sector lock bit operation (in ms)
4160 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4161 Timeout for Flash clear lock bits operation (in ms)
4163 - CONFIG_SYS_FLASH_PROTECTION
4164 If defined, hardware flash sectors protection is used
4165 instead of U-Boot software protection.
4167 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4169 Enable TFTP transfers directly to flash memory;
4170 without this option such a download has to be
4171 performed in two steps: (1) download to RAM, and (2)
4172 copy from RAM to flash.
4174 The two-step approach is usually more reliable, since
4175 you can check if the download worked before you erase
4176 the flash, but in some situations (when system RAM is
4177 too limited to allow for a temporary copy of the
4178 downloaded image) this option may be very useful.
4180 - CONFIG_SYS_FLASH_CFI:
4181 Define if the flash driver uses extra elements in the
4182 common flash structure for storing flash geometry.
4184 - CONFIG_FLASH_CFI_DRIVER
4185 This option also enables the building of the cfi_flash driver
4186 in the drivers directory
4188 - CONFIG_FLASH_CFI_MTD
4189 This option enables the building of the cfi_mtd driver
4190 in the drivers directory. The driver exports CFI flash
4193 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4194 Use buffered writes to flash.
4196 - CONFIG_FLASH_SPANSION_S29WS_N
4197 s29ws-n MirrorBit flash has non-standard addresses for buffered
4200 - CONFIG_SYS_FLASH_QUIET_TEST
4201 If this option is defined, the common CFI flash doesn't
4202 print it's warning upon not recognized FLASH banks. This
4203 is useful, if some of the configured banks are only
4204 optionally available.
4206 - CONFIG_FLASH_SHOW_PROGRESS
4207 If defined (must be an integer), print out countdown
4208 digits and dots. Recommended value: 45 (9..1) for 80
4209 column displays, 15 (3..1) for 40 column displays.
4211 - CONFIG_FLASH_VERIFY
4212 If defined, the content of the flash (destination) is compared
4213 against the source after the write operation. An error message
4214 will be printed when the contents are not identical.
4215 Please note that this option is useless in nearly all cases,
4216 since such flash programming errors usually are detected earlier
4217 while unprotecting/erasing/programming. Please only enable
4218 this option if you really know what you are doing.
4220 - CONFIG_SYS_RX_ETH_BUFFER:
4221 Defines the number of Ethernet receive buffers. On some
4222 Ethernet controllers it is recommended to set this value
4223 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4224 buffers can be full shortly after enabling the interface
4225 on high Ethernet traffic.
4226 Defaults to 4 if not defined.
4228 - CONFIG_ENV_MAX_ENTRIES
4230 Maximum number of entries in the hash table that is used
4231 internally to store the environment settings. The default
4232 setting is supposed to be generous and should work in most
4233 cases. This setting can be used to tune behaviour; see
4234 lib/hashtable.c for details.
4236 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4237 - CONFIG_ENV_FLAGS_LIST_STATIC
4238 Enable validation of the values given to environment variables when
4239 calling env set. Variables can be restricted to only decimal,
4240 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4241 the variables can also be restricted to IP address or MAC address.
4243 The format of the list is:
4244 type_attribute = [s|d|x|b|i|m]
4245 access_attribute = [a|r|o|c]
4246 attributes = type_attribute[access_attribute]
4247 entry = variable_name[:attributes]
4250 The type attributes are:
4251 s - String (default)
4254 b - Boolean ([1yYtT|0nNfF])
4258 The access attributes are:
4264 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4265 Define this to a list (string) to define the ".flags"
4266 environment variable in the default or embedded environment.
4268 - CONFIG_ENV_FLAGS_LIST_STATIC
4269 Define this to a list (string) to define validation that
4270 should be done if an entry is not found in the ".flags"
4271 environment variable. To override a setting in the static
4272 list, simply add an entry for the same variable name to the
4275 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4276 regular expression. This allows multiple variables to define the same
4277 flags without explicitly listing them for each variable.
4279 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4280 If defined, don't allow the -f switch to env set override variable
4283 - CONFIG_SYS_GENERIC_BOARD
4284 This selects the architecture-generic board system instead of the
4285 architecture-specific board files. It is intended to move boards
4286 to this new framework over time. Defining this will disable the
4287 arch/foo/lib/board.c file and use common/board_f.c and
4288 common/board_r.c instead. To use this option your architecture
4289 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4290 If you find problems enabling this option on your board please report
4291 the problem and send patches!
4293 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4294 This is set by OMAP boards for the max time that reset should
4295 be asserted. See doc/README.omap-reset-time for details on how
4296 the value can be calculated on a given board.
4299 If stdint.h is available with your toolchain you can define this
4300 option to enable it. You can provide option 'USE_STDINT=1' when
4301 building U-Boot to enable this.
4303 The following definitions that deal with the placement and management
4304 of environment data (variable area); in general, we support the
4305 following configurations:
4307 - CONFIG_BUILD_ENVCRC:
4309 Builds up envcrc with the target environment so that external utils
4310 may easily extract it and embed it in final U-Boot images.
4312 - CONFIG_ENV_IS_IN_FLASH:
4314 Define this if the environment is in flash memory.
4316 a) The environment occupies one whole flash sector, which is
4317 "embedded" in the text segment with the U-Boot code. This
4318 happens usually with "bottom boot sector" or "top boot
4319 sector" type flash chips, which have several smaller
4320 sectors at the start or the end. For instance, such a
4321 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4322 such a case you would place the environment in one of the
4323 4 kB sectors - with U-Boot code before and after it. With
4324 "top boot sector" type flash chips, you would put the
4325 environment in one of the last sectors, leaving a gap
4326 between U-Boot and the environment.
4328 - CONFIG_ENV_OFFSET:
4330 Offset of environment data (variable area) to the
4331 beginning of flash memory; for instance, with bottom boot
4332 type flash chips the second sector can be used: the offset
4333 for this sector is given here.
4335 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4339 This is just another way to specify the start address of
4340 the flash sector containing the environment (instead of
4343 - CONFIG_ENV_SECT_SIZE:
4345 Size of the sector containing the environment.
4348 b) Sometimes flash chips have few, equal sized, BIG sectors.
4349 In such a case you don't want to spend a whole sector for
4354 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4355 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4356 of this flash sector for the environment. This saves
4357 memory for the RAM copy of the environment.
4359 It may also save flash memory if you decide to use this
4360 when your environment is "embedded" within U-Boot code,
4361 since then the remainder of the flash sector could be used
4362 for U-Boot code. It should be pointed out that this is
4363 STRONGLY DISCOURAGED from a robustness point of view:
4364 updating the environment in flash makes it always
4365 necessary to erase the WHOLE sector. If something goes
4366 wrong before the contents has been restored from a copy in
4367 RAM, your target system will be dead.
4369 - CONFIG_ENV_ADDR_REDUND
4370 CONFIG_ENV_SIZE_REDUND
4372 These settings describe a second storage area used to hold
4373 a redundant copy of the environment data, so that there is
4374 a valid backup copy in case there is a power failure during
4375 a "saveenv" operation.
4377 BE CAREFUL! Any changes to the flash layout, and some changes to the
4378 source code will make it necessary to adapt <board>/u-boot.lds*
4382 - CONFIG_ENV_IS_IN_NVRAM:
4384 Define this if you have some non-volatile memory device
4385 (NVRAM, battery buffered SRAM) which you want to use for the
4391 These two #defines are used to determine the memory area you
4392 want to use for environment. It is assumed that this memory
4393 can just be read and written to, without any special
4396 BE CAREFUL! The first access to the environment happens quite early
4397 in U-Boot initialization (when we try to get the setting of for the
4398 console baudrate). You *MUST* have mapped your NVRAM area then, or
4401 Please note that even with NVRAM we still use a copy of the
4402 environment in RAM: we could work on NVRAM directly, but we want to
4403 keep settings there always unmodified except somebody uses "saveenv"
4404 to save the current settings.
4407 - CONFIG_ENV_IS_IN_EEPROM:
4409 Use this if you have an EEPROM or similar serial access
4410 device and a driver for it.
4412 - CONFIG_ENV_OFFSET:
4415 These two #defines specify the offset and size of the
4416 environment area within the total memory of your EEPROM.
4418 - CONFIG_SYS_I2C_EEPROM_ADDR:
4419 If defined, specified the chip address of the EEPROM device.
4420 The default address is zero.
4422 - CONFIG_SYS_I2C_EEPROM_BUS:
4423 If defined, specified the i2c bus of the EEPROM device.
4425 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4426 If defined, the number of bits used to address bytes in a
4427 single page in the EEPROM device. A 64 byte page, for example
4428 would require six bits.
4430 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4431 If defined, the number of milliseconds to delay between
4432 page writes. The default is zero milliseconds.
4434 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4435 The length in bytes of the EEPROM memory array address. Note
4436 that this is NOT the chip address length!
4438 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4439 EEPROM chips that implement "address overflow" are ones
4440 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4441 address and the extra bits end up in the "chip address" bit
4442 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4445 Note that we consider the length of the address field to
4446 still be one byte because the extra address bits are hidden
4447 in the chip address.
4449 - CONFIG_SYS_EEPROM_SIZE:
4450 The size in bytes of the EEPROM device.
4452 - CONFIG_ENV_EEPROM_IS_ON_I2C
4453 define this, if you have I2C and SPI activated, and your
4454 EEPROM, which holds the environment, is on the I2C bus.
4456 - CONFIG_I2C_ENV_EEPROM_BUS
4457 if you have an Environment on an EEPROM reached over
4458 I2C muxes, you can define here, how to reach this
4459 EEPROM. For example:
4461 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4463 EEPROM which holds the environment, is reached over
4464 a pca9547 i2c mux with address 0x70, channel 3.
4466 - CONFIG_ENV_IS_IN_DATAFLASH:
4468 Define this if you have a DataFlash memory device which you
4469 want to use for the environment.
4471 - CONFIG_ENV_OFFSET:
4475 These three #defines specify the offset and size of the
4476 environment area within the total memory of your DataFlash placed
4477 at the specified address.
4479 - CONFIG_ENV_IS_IN_SPI_FLASH:
4481 Define this if you have a SPI Flash memory device which you
4482 want to use for the environment.
4484 - CONFIG_ENV_OFFSET:
4487 These two #defines specify the offset and size of the
4488 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4489 aligned to an erase sector boundary.
4491 - CONFIG_ENV_SECT_SIZE:
4493 Define the SPI flash's sector size.
4495 - CONFIG_ENV_OFFSET_REDUND (optional):
4497 This setting describes a second storage area of CONFIG_ENV_SIZE
4498 size used to hold a redundant copy of the environment data, so
4499 that there is a valid backup copy in case there is a power failure
4500 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4501 aligned to an erase sector boundary.
4503 - CONFIG_ENV_SPI_BUS (optional):
4504 - CONFIG_ENV_SPI_CS (optional):
4506 Define the SPI bus and chip select. If not defined they will be 0.
4508 - CONFIG_ENV_SPI_MAX_HZ (optional):
4510 Define the SPI max work clock. If not defined then use 1MHz.
4512 - CONFIG_ENV_SPI_MODE (optional):
4514 Define the SPI work mode. If not defined then use SPI_MODE_3.
4516 - CONFIG_ENV_IS_IN_REMOTE:
4518 Define this if you have a remote memory space which you
4519 want to use for the local device's environment.
4524 These two #defines specify the address and size of the
4525 environment area within the remote memory space. The
4526 local device can get the environment from remote memory
4527 space by SRIO or PCIE links.
4529 BE CAREFUL! For some special cases, the local device can not use
4530 "saveenv" command. For example, the local device will get the
4531 environment stored in a remote NOR flash by SRIO or PCIE link,
4532 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4534 - CONFIG_ENV_IS_IN_NAND:
4536 Define this if you have a NAND device which you want to use
4537 for the environment.
4539 - CONFIG_ENV_OFFSET:
4542 These two #defines specify the offset and size of the environment
4543 area within the first NAND device. CONFIG_ENV_OFFSET must be
4544 aligned to an erase block boundary.
4546 - CONFIG_ENV_OFFSET_REDUND (optional):
4548 This setting describes a second storage area of CONFIG_ENV_SIZE
4549 size used to hold a redundant copy of the environment data, so
4550 that there is a valid backup copy in case there is a power failure
4551 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4552 aligned to an erase block boundary.
4554 - CONFIG_ENV_RANGE (optional):
4556 Specifies the length of the region in which the environment
4557 can be written. This should be a multiple of the NAND device's
4558 block size. Specifying a range with more erase blocks than
4559 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4560 the range to be avoided.
4562 - CONFIG_ENV_OFFSET_OOB (optional):
4564 Enables support for dynamically retrieving the offset of the
4565 environment from block zero's out-of-band data. The
4566 "nand env.oob" command can be used to record this offset.
4567 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4568 using CONFIG_ENV_OFFSET_OOB.
4570 - CONFIG_NAND_ENV_DST
4572 Defines address in RAM to which the nand_spl code should copy the
4573 environment. If redundant environment is used, it will be copied to
4574 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4576 - CONFIG_ENV_IS_IN_UBI:
4578 Define this if you have an UBI volume that you want to use for the
4579 environment. This has the benefit of wear-leveling the environment
4580 accesses, which is important on NAND.
4582 - CONFIG_ENV_UBI_PART:
4584 Define this to a string that is the mtd partition containing the UBI.
4586 - CONFIG_ENV_UBI_VOLUME:
4588 Define this to the name of the volume that you want to store the
4591 - CONFIG_ENV_UBI_VOLUME_REDUND:
4593 Define this to the name of another volume to store a second copy of
4594 the environment in. This will enable redundant environments in UBI.
4595 It is assumed that both volumes are in the same MTD partition.
4597 - CONFIG_UBI_SILENCE_MSG
4598 - CONFIG_UBIFS_SILENCE_MSG
4600 You will probably want to define these to avoid a really noisy system
4601 when storing the env in UBI.
4603 - CONFIG_ENV_IS_IN_FAT:
4604 Define this if you want to use the FAT file system for the environment.
4606 - FAT_ENV_INTERFACE:
4608 Define this to a string that is the name of the block device.
4610 - FAT_ENV_DEV_AND_PART:
4612 Define this to a string to specify the partition of the device. It can
4615 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4616 - "D:P": device D partition P. Error occurs if device D has no
4619 - "D" or "D:": device D partition 1 if device D has partition
4620 table, or the whole device D if has no partition
4622 - "D:auto": first partition in device D with bootable flag set.
4623 If none, first valid partition in device D. If no
4624 partition table then means device D.
4628 It's a string of the FAT file name. This file use to store the
4632 This should be defined. Otherwise it cannot save the environment file.
4634 - CONFIG_ENV_IS_IN_MMC:
4636 Define this if you have an MMC device which you want to use for the
4639 - CONFIG_SYS_MMC_ENV_DEV:
4641 Specifies which MMC device the environment is stored in.
4643 - CONFIG_SYS_MMC_ENV_PART (optional):
4645 Specifies which MMC partition the environment is stored in. If not
4646 set, defaults to partition 0, the user area. Common values might be
4647 1 (first MMC boot partition), 2 (second MMC boot partition).
4649 - CONFIG_ENV_OFFSET:
4652 These two #defines specify the offset and size of the environment
4653 area within the specified MMC device.
4655 If offset is positive (the usual case), it is treated as relative to
4656 the start of the MMC partition. If offset is negative, it is treated
4657 as relative to the end of the MMC partition. This can be useful if
4658 your board may be fitted with different MMC devices, which have
4659 different sizes for the MMC partitions, and you always want the
4660 environment placed at the very end of the partition, to leave the
4661 maximum possible space before it, to store other data.
4663 These two values are in units of bytes, but must be aligned to an
4664 MMC sector boundary.
4666 - CONFIG_ENV_OFFSET_REDUND (optional):
4668 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4669 hold a redundant copy of the environment data. This provides a
4670 valid backup copy in case the other copy is corrupted, e.g. due
4671 to a power failure during a "saveenv" operation.
4673 This value may also be positive or negative; this is handled in the
4674 same way as CONFIG_ENV_OFFSET.
4676 This value is also in units of bytes, but must also be aligned to
4677 an MMC sector boundary.
4679 - CONFIG_ENV_SIZE_REDUND (optional):
4681 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4682 set. If this value is set, it must be set to the same value as
4685 - CONFIG_SYS_SPI_INIT_OFFSET
4687 Defines offset to the initial SPI buffer area in DPRAM. The
4688 area is used at an early stage (ROM part) if the environment
4689 is configured to reside in the SPI EEPROM: We need a 520 byte
4690 scratch DPRAM area. It is used between the two initialization
4691 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4692 to be a good choice since it makes it far enough from the
4693 start of the data area as well as from the stack pointer.
4695 Please note that the environment is read-only until the monitor
4696 has been relocated to RAM and a RAM copy of the environment has been
4697 created; also, when using EEPROM you will have to use getenv_f()
4698 until then to read environment variables.
4700 The environment is protected by a CRC32 checksum. Before the monitor
4701 is relocated into RAM, as a result of a bad CRC you will be working
4702 with the compiled-in default environment - *silently*!!! [This is
4703 necessary, because the first environment variable we need is the
4704 "baudrate" setting for the console - if we have a bad CRC, we don't
4705 have any device yet where we could complain.]
4707 Note: once the monitor has been relocated, then it will complain if
4708 the default environment is used; a new CRC is computed as soon as you
4709 use the "saveenv" command to store a valid environment.
4711 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4712 Echo the inverted Ethernet link state to the fault LED.
4714 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4715 also needs to be defined.
4717 - CONFIG_SYS_FAULT_MII_ADDR:
4718 MII address of the PHY to check for the Ethernet link state.
4720 - CONFIG_NS16550_MIN_FUNCTIONS:
4721 Define this if you desire to only have use of the NS16550_init
4722 and NS16550_putc functions for the serial driver located at
4723 drivers/serial/ns16550.c. This option is useful for saving
4724 space for already greatly restricted images, including but not
4725 limited to NAND_SPL configurations.
4727 - CONFIG_DISPLAY_BOARDINFO
4728 Display information about the board that U-Boot is running on
4729 when U-Boot starts up. The board function checkboard() is called
4732 - CONFIG_DISPLAY_BOARDINFO_LATE
4733 Similar to the previous option, but display this information
4734 later, once stdio is running and output goes to the LCD, if
4737 - CONFIG_BOARD_SIZE_LIMIT:
4738 Maximum size of the U-Boot image. When defined, the
4739 build system checks that the actual size does not
4742 Low Level (hardware related) configuration options:
4743 ---------------------------------------------------
4745 - CONFIG_SYS_CACHELINE_SIZE:
4746 Cache Line Size of the CPU.
4748 - CONFIG_SYS_DEFAULT_IMMR:
4749 Default address of the IMMR after system reset.
4751 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4752 and RPXsuper) to be able to adjust the position of
4753 the IMMR register after a reset.
4755 - CONFIG_SYS_CCSRBAR_DEFAULT:
4756 Default (power-on reset) physical address of CCSR on Freescale
4759 - CONFIG_SYS_CCSRBAR:
4760 Virtual address of CCSR. On a 32-bit build, this is typically
4761 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4763 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4764 for cross-platform code that uses that macro instead.
4766 - CONFIG_SYS_CCSRBAR_PHYS:
4767 Physical address of CCSR. CCSR can be relocated to a new
4768 physical address, if desired. In this case, this macro should
4769 be set to that address. Otherwise, it should be set to the
4770 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4771 is typically relocated on 36-bit builds. It is recommended
4772 that this macro be defined via the _HIGH and _LOW macros:
4774 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4775 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4777 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4778 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4779 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4780 used in assembly code, so it must not contain typecasts or
4781 integer size suffixes (e.g. "ULL").
4783 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4784 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4785 used in assembly code, so it must not contain typecasts or
4786 integer size suffixes (e.g. "ULL").
4788 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4789 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4790 forced to a value that ensures that CCSR is not relocated.
4792 - Floppy Disk Support:
4793 CONFIG_SYS_FDC_DRIVE_NUMBER
4795 the default drive number (default value 0)
4797 CONFIG_SYS_ISA_IO_STRIDE
4799 defines the spacing between FDC chipset registers
4802 CONFIG_SYS_ISA_IO_OFFSET
4804 defines the offset of register from address. It
4805 depends on which part of the data bus is connected to
4806 the FDC chipset. (default value 0)
4808 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4809 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4812 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4813 fdc_hw_init() is called at the beginning of the FDC
4814 setup. fdc_hw_init() must be provided by the board
4815 source code. It is used to make hardware-dependent
4819 Most IDE controllers were designed to be connected with PCI
4820 interface. Only few of them were designed for AHB interface.
4821 When software is doing ATA command and data transfer to
4822 IDE devices through IDE-AHB controller, some additional
4823 registers accessing to these kind of IDE-AHB controller
4826 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4827 DO NOT CHANGE unless you know exactly what you're
4828 doing! (11-4) [MPC8xx/82xx systems only]
4830 - CONFIG_SYS_INIT_RAM_ADDR:
4832 Start address of memory area that can be used for
4833 initial data and stack; please note that this must be
4834 writable memory that is working WITHOUT special
4835 initialization, i. e. you CANNOT use normal RAM which
4836 will become available only after programming the
4837 memory controller and running certain initialization
4840 U-Boot uses the following memory types:
4841 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4842 - MPC824X: data cache
4843 - PPC4xx: data cache
4845 - CONFIG_SYS_GBL_DATA_OFFSET:
4847 Offset of the initial data structure in the memory
4848 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4849 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4850 data is located at the end of the available space
4851 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4852 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4853 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4854 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4857 On the MPC824X (or other systems that use the data
4858 cache for initial memory) the address chosen for
4859 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4860 point to an otherwise UNUSED address space between
4861 the top of RAM and the start of the PCI space.
4863 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4865 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4867 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4869 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4871 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4873 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4875 - CONFIG_SYS_OR_TIMING_SDRAM:
4878 - CONFIG_SYS_MAMR_PTA:
4879 periodic timer for refresh
4881 - CONFIG_SYS_DER: Debug Event Register (37-47)
4883 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4884 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4885 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4886 CONFIG_SYS_BR1_PRELIM:
4887 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4889 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4890 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4891 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4892 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4894 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4895 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4896 Machine Mode Register and Memory Periodic Timer
4897 Prescaler definitions (SDRAM timing)
4899 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4900 enable I2C microcode relocation patch (MPC8xx);
4901 define relocation offset in DPRAM [DSP2]
4903 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4904 enable SMC microcode relocation patch (MPC8xx);
4905 define relocation offset in DPRAM [SMC1]
4907 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4908 enable SPI microcode relocation patch (MPC8xx);
4909 define relocation offset in DPRAM [SCC4]
4911 - CONFIG_SYS_USE_OSCCLK:
4912 Use OSCM clock mode on MBX8xx board. Be careful,
4913 wrong setting might damage your board. Read
4914 doc/README.MBX before setting this variable!
4916 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4917 Offset of the bootmode word in DPRAM used by post
4918 (Power On Self Tests). This definition overrides
4919 #define'd default value in commproc.h resp.
4922 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4923 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4924 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4925 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4926 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4927 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4928 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4929 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4930 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4932 - CONFIG_PCI_DISABLE_PCIE:
4933 Disable PCI-Express on systems where it is supported but not
4936 - CONFIG_PCI_ENUM_ONLY
4937 Only scan through and get the devices on the buses.
4938 Don't do any setup work, presumably because someone or
4939 something has already done it, and we don't need to do it
4940 a second time. Useful for platforms that are pre-booted
4941 by coreboot or similar.
4943 - CONFIG_PCI_INDIRECT_BRIDGE:
4944 Enable support for indirect PCI bridges.
4947 Chip has SRIO or not
4950 Board has SRIO 1 port available
4953 Board has SRIO 2 port available
4955 - CONFIG_SRIO_PCIE_BOOT_MASTER
4956 Board can support master function for Boot from SRIO and PCIE
4958 - CONFIG_SYS_SRIOn_MEM_VIRT:
4959 Virtual Address of SRIO port 'n' memory region
4961 - CONFIG_SYS_SRIOn_MEM_PHYS:
4962 Physical Address of SRIO port 'n' memory region
4964 - CONFIG_SYS_SRIOn_MEM_SIZE:
4965 Size of SRIO port 'n' memory region
4967 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4968 Defined to tell the NAND controller that the NAND chip is using
4970 Not all NAND drivers use this symbol.
4971 Example of drivers that use it:
4972 - drivers/mtd/nand/ndfc.c
4973 - drivers/mtd/nand/mxc_nand.c
4975 - CONFIG_SYS_NDFC_EBC0_CFG
4976 Sets the EBC0_CFG register for the NDFC. If not defined
4977 a default value will be used.
4980 Get DDR timing information from an I2C EEPROM. Common
4981 with pluggable memory modules such as SODIMMs
4984 I2C address of the SPD EEPROM
4986 - CONFIG_SYS_SPD_BUS_NUM
4987 If SPD EEPROM is on an I2C bus other than the first
4988 one, specify here. Note that the value must resolve
4989 to something your driver can deal with.
4991 - CONFIG_SYS_DDR_RAW_TIMING
4992 Get DDR timing information from other than SPD. Common with
4993 soldered DDR chips onboard without SPD. DDR raw timing
4994 parameters are extracted from datasheet and hard-coded into
4995 header files or board specific files.
4997 - CONFIG_FSL_DDR_INTERACTIVE
4998 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5000 - CONFIG_FSL_DDR_SYNC_REFRESH
5001 Enable sync of refresh for multiple controllers.
5003 - CONFIG_FSL_DDR_BIST
5004 Enable built-in memory test for Freescale DDR controllers.
5006 - CONFIG_SYS_83XX_DDR_USES_CS0
5007 Only for 83xx systems. If specified, then DDR should
5008 be configured using CS0 and CS1 instead of CS2 and CS3.
5010 - CONFIG_ETHER_ON_FEC[12]
5011 Define to enable FEC[12] on a 8xx series processor.
5013 - CONFIG_FEC[12]_PHY
5014 Define to the hardcoded PHY address which corresponds
5015 to the given FEC; i. e.
5016 #define CONFIG_FEC1_PHY 4
5017 means that the PHY with address 4 is connected to FEC1
5019 When set to -1, means to probe for first available.
5021 - CONFIG_FEC[12]_PHY_NORXERR
5022 The PHY does not have a RXERR line (RMII only).
5023 (so program the FEC to ignore it).
5026 Enable RMII mode for all FECs.
5027 Note that this is a global option, we can't
5028 have one FEC in standard MII mode and another in RMII mode.
5030 - CONFIG_CRC32_VERIFY
5031 Add a verify option to the crc32 command.
5034 => crc32 -v <address> <count> <crc32>
5036 Where address/count indicate a memory area
5037 and crc32 is the correct crc32 which the
5041 Add the "loopw" memory command. This only takes effect if
5042 the memory commands are activated globally (CONFIG_CMD_MEM).
5045 Add the "mdc" and "mwc" memory commands. These are cyclic
5050 This command will print 4 bytes (10,11,12,13) each 500 ms.
5052 => mwc.l 100 12345678 10
5053 This command will write 12345678 to address 100 all 10 ms.
5055 This only takes effect if the memory commands are activated
5056 globally (CONFIG_CMD_MEM).
5058 - CONFIG_SKIP_LOWLEVEL_INIT
5059 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5060 low level initializations (like setting up the memory
5061 controller) are omitted and/or U-Boot does not
5062 relocate itself into RAM.
5064 Normally this variable MUST NOT be defined. The only
5065 exception is when U-Boot is loaded (to RAM) by some
5066 other boot loader or by a debugger which performs
5067 these initializations itself.
5070 Modifies the behaviour of start.S when compiling a loader
5071 that is executed before the actual U-Boot. E.g. when
5072 compiling a NAND SPL.
5075 Modifies the behaviour of start.S when compiling a loader
5076 that is executed after the SPL and before the actual U-Boot.
5077 It is loaded by the SPL.
5079 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5080 Only for 85xx systems. If this variable is specified, the section
5081 .resetvec is not kept and the section .bootpg is placed in the
5082 previous 4k of the .text section.
5084 - CONFIG_ARCH_MAP_SYSMEM
5085 Generally U-Boot (and in particular the md command) uses
5086 effective address. It is therefore not necessary to regard
5087 U-Boot address as virtual addresses that need to be translated
5088 to physical addresses. However, sandbox requires this, since
5089 it maintains its own little RAM buffer which contains all
5090 addressable memory. This option causes some memory accesses
5091 to be mapped through map_sysmem() / unmap_sysmem().
5093 - CONFIG_USE_ARCH_MEMCPY
5094 CONFIG_USE_ARCH_MEMSET
5095 If these options are used a optimized version of memcpy/memset will
5096 be used if available. These functions may be faster under some
5097 conditions but may increase the binary size.
5099 - CONFIG_X86_RESET_VECTOR
5100 If defined, the x86 reset vector code is included. This is not
5101 needed when U-Boot is running from Coreboot.
5104 Defines the MPU clock speed (in MHz).
5106 NOTE : currently only supported on AM335x platforms.
5108 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5109 Enables the RTC32K OSC on AM33xx based plattforms
5111 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5112 Option to disable subpage write in NAND driver
5113 driver that uses this:
5114 drivers/mtd/nand/davinci_nand.c
5116 Freescale QE/FMAN Firmware Support:
5117 -----------------------------------
5119 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5120 loading of "firmware", which is encoded in the QE firmware binary format.
5121 This firmware often needs to be loaded during U-Boot booting, so macros
5122 are used to identify the storage device (NOR flash, SPI, etc) and the address
5125 - CONFIG_SYS_FMAN_FW_ADDR
5126 The address in the storage device where the FMAN microcode is located. The
5127 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5130 - CONFIG_SYS_QE_FW_ADDR
5131 The address in the storage device where the QE microcode is located. The
5132 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5135 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5136 The maximum possible size of the firmware. The firmware binary format
5137 has a field that specifies the actual size of the firmware, but it
5138 might not be possible to read any part of the firmware unless some
5139 local storage is allocated to hold the entire firmware first.
5141 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5142 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5143 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5144 virtual address in NOR flash.
5146 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5147 Specifies that QE/FMAN firmware is located in NAND flash.
5148 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5150 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5151 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5152 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5154 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5155 Specifies that QE/FMAN firmware is located on the primary SPI
5156 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5158 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5159 Specifies that QE/FMAN firmware is located in the remote (master)
5160 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5161 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5162 window->master inbound window->master LAW->the ucode address in
5163 master's memory space.
5165 Freescale Layerscape Management Complex Firmware Support:
5166 ---------------------------------------------------------
5167 The Freescale Layerscape Management Complex (MC) supports the loading of
5169 This firmware often needs to be loaded during U-Boot booting, so macros
5170 are used to identify the storage device (NOR flash, SPI, etc) and the address
5173 - CONFIG_FSL_MC_ENET
5174 Enable the MC driver for Layerscape SoCs.
5176 - CONFIG_SYS_LS_MC_FW_ADDR
5177 The address in the storage device where the firmware is located. The
5178 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5181 - CONFIG_SYS_LS_MC_FW_LENGTH
5182 The maximum possible size of the firmware. The firmware binary format
5183 has a field that specifies the actual size of the firmware, but it
5184 might not be possible to read any part of the firmware unless some
5185 local storage is allocated to hold the entire firmware first.
5187 - CONFIG_SYS_LS_MC_FW_IN_NOR
5188 Specifies that MC firmware is located in NOR flash, mapped as
5189 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5190 virtual address in NOR flash.
5192 Building the Software:
5193 ======================
5195 Building U-Boot has been tested in several native build environments
5196 and in many different cross environments. Of course we cannot support
5197 all possibly existing versions of cross development tools in all
5198 (potentially obsolete) versions. In case of tool chain problems we
5199 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5200 which is extensively used to build and test U-Boot.
5202 If you are not using a native environment, it is assumed that you
5203 have GNU cross compiling tools available in your path. In this case,
5204 you must set the environment variable CROSS_COMPILE in your shell.
5205 Note that no changes to the Makefile or any other source files are
5206 necessary. For example using the ELDK on a 4xx CPU, please enter:
5208 $ CROSS_COMPILE=ppc_4xx-
5209 $ export CROSS_COMPILE
5211 Note: If you wish to generate Windows versions of the utilities in
5212 the tools directory you can use the MinGW toolchain
5213 (http://www.mingw.org). Set your HOST tools to the MinGW
5214 toolchain and execute 'make tools'. For example:
5216 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5218 Binaries such as tools/mkimage.exe will be created which can
5219 be executed on computers running Windows.
5221 U-Boot is intended to be simple to build. After installing the
5222 sources you must configure U-Boot for one specific board type. This
5227 where "NAME_defconfig" is the name of one of the existing configu-
5228 rations; see boards.cfg for supported names.
5230 Note: for some board special configuration names may exist; check if
5231 additional information is available from the board vendor; for
5232 instance, the TQM823L systems are available without (standard)
5233 or with LCD support. You can select such additional "features"
5234 when choosing the configuration, i. e.
5236 make TQM823L_defconfig
5237 - will configure for a plain TQM823L, i. e. no LCD support
5239 make TQM823L_LCD_defconfig
5240 - will configure for a TQM823L with U-Boot console on LCD
5245 Finally, type "make all", and you should get some working U-Boot
5246 images ready for download to / installation on your system:
5248 - "u-boot.bin" is a raw binary image
5249 - "u-boot" is an image in ELF binary format
5250 - "u-boot.srec" is in Motorola S-Record format
5252 By default the build is performed locally and the objects are saved
5253 in the source directory. One of the two methods can be used to change
5254 this behavior and build U-Boot to some external directory:
5256 1. Add O= to the make command line invocations:
5258 make O=/tmp/build distclean
5259 make O=/tmp/build NAME_defconfig
5260 make O=/tmp/build all
5262 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5264 export KBUILD_OUTPUT=/tmp/build
5269 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5273 Please be aware that the Makefiles assume you are using GNU make, so
5274 for instance on NetBSD you might need to use "gmake" instead of
5278 If the system board that you have is not listed, then you will need
5279 to port U-Boot to your hardware platform. To do this, follow these
5282 1. Add a new configuration option for your board to the toplevel
5283 "boards.cfg" file, using the existing entries as examples.
5284 Follow the instructions there to keep the boards in order.
5285 2. Create a new directory to hold your board specific code. Add any
5286 files you need. In your board directory, you will need at least
5287 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5288 3. Create a new configuration file "include/configs/<board>.h" for
5290 3. If you're porting U-Boot to a new CPU, then also create a new
5291 directory to hold your CPU specific code. Add any files you need.
5292 4. Run "make <board>_defconfig" with your new name.
5293 5. Type "make", and you should get a working "u-boot.srec" file
5294 to be installed on your target system.
5295 6. Debug and solve any problems that might arise.
5296 [Of course, this last step is much harder than it sounds.]
5299 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5300 ==============================================================
5302 If you have modified U-Boot sources (for instance added a new board
5303 or support for new devices, a new CPU, etc.) you are expected to
5304 provide feedback to the other developers. The feedback normally takes
5305 the form of a "patch", i. e. a context diff against a certain (latest
5306 official or latest in the git repository) version of U-Boot sources.
5308 But before you submit such a patch, please verify that your modifi-
5309 cation did not break existing code. At least make sure that *ALL* of
5310 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5311 just run the "MAKEALL" script, which will configure and build U-Boot
5312 for ALL supported system. Be warned, this will take a while. You can
5313 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5314 environment variable to the script, i. e. to use the ELDK cross tools
5317 CROSS_COMPILE=ppc_8xx- MAKEALL
5319 or to build on a native PowerPC system you can type
5321 CROSS_COMPILE=' ' MAKEALL
5323 When using the MAKEALL script, the default behaviour is to build
5324 U-Boot in the source directory. This location can be changed by
5325 setting the BUILD_DIR environment variable. Also, for each target
5326 built, the MAKEALL script saves two log files (<target>.ERR and
5327 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5328 location can be changed by setting the MAKEALL_LOGDIR environment
5329 variable. For example:
5331 export BUILD_DIR=/tmp/build
5332 export MAKEALL_LOGDIR=/tmp/log
5333 CROSS_COMPILE=ppc_8xx- MAKEALL
5335 With the above settings build objects are saved in the /tmp/build,
5336 log files are saved in the /tmp/log and the source tree remains clean
5337 during the whole build process.
5340 See also "U-Boot Porting Guide" below.
5343 Monitor Commands - Overview:
5344 ============================
5346 go - start application at address 'addr'
5347 run - run commands in an environment variable
5348 bootm - boot application image from memory
5349 bootp - boot image via network using BootP/TFTP protocol
5350 bootz - boot zImage from memory
5351 tftpboot- boot image via network using TFTP protocol
5352 and env variables "ipaddr" and "serverip"
5353 (and eventually "gatewayip")
5354 tftpput - upload a file via network using TFTP protocol
5355 rarpboot- boot image via network using RARP/TFTP protocol
5356 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5357 loads - load S-Record file over serial line
5358 loadb - load binary file over serial line (kermit mode)
5360 mm - memory modify (auto-incrementing)
5361 nm - memory modify (constant address)
5362 mw - memory write (fill)
5364 cmp - memory compare
5365 crc32 - checksum calculation
5366 i2c - I2C sub-system
5367 sspi - SPI utility commands
5368 base - print or set address offset
5369 printenv- print environment variables
5370 setenv - set environment variables
5371 saveenv - save environment variables to persistent storage
5372 protect - enable or disable FLASH write protection
5373 erase - erase FLASH memory
5374 flinfo - print FLASH memory information
5375 nand - NAND memory operations (see doc/README.nand)
5376 bdinfo - print Board Info structure
5377 iminfo - print header information for application image
5378 coninfo - print console devices and informations
5379 ide - IDE sub-system
5380 loop - infinite loop on address range
5381 loopw - infinite write loop on address range
5382 mtest - simple RAM test
5383 icache - enable or disable instruction cache
5384 dcache - enable or disable data cache
5385 reset - Perform RESET of the CPU
5386 echo - echo args to console
5387 version - print monitor version
5388 help - print online help
5389 ? - alias for 'help'
5392 Monitor Commands - Detailed Description:
5393 ========================================
5397 For now: just type "help <command>".
5400 Environment Variables:
5401 ======================
5403 U-Boot supports user configuration using Environment Variables which
5404 can be made persistent by saving to Flash memory.
5406 Environment Variables are set using "setenv", printed using
5407 "printenv", and saved to Flash using "saveenv". Using "setenv"
5408 without a value can be used to delete a variable from the
5409 environment. As long as you don't save the environment you are
5410 working with an in-memory copy. In case the Flash area containing the
5411 environment is erased by accident, a default environment is provided.
5413 Some configuration options can be set using Environment Variables.
5415 List of environment variables (most likely not complete):
5417 baudrate - see CONFIG_BAUDRATE
5419 bootdelay - see CONFIG_BOOTDELAY
5421 bootcmd - see CONFIG_BOOTCOMMAND
5423 bootargs - Boot arguments when booting an RTOS image
5425 bootfile - Name of the image to load with TFTP
5427 bootm_low - Memory range available for image processing in the bootm
5428 command can be restricted. This variable is given as
5429 a hexadecimal number and defines lowest address allowed
5430 for use by the bootm command. See also "bootm_size"
5431 environment variable. Address defined by "bootm_low" is
5432 also the base of the initial memory mapping for the Linux
5433 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5436 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5437 This variable is given as a hexadecimal number and it
5438 defines the size of the memory region starting at base
5439 address bootm_low that is accessible by the Linux kernel
5440 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5441 as the default value if it is defined, and bootm_size is
5444 bootm_size - Memory range available for image processing in the bootm
5445 command can be restricted. This variable is given as
5446 a hexadecimal number and defines the size of the region
5447 allowed for use by the bootm command. See also "bootm_low"
5448 environment variable.
5450 updatefile - Location of the software update file on a TFTP server, used
5451 by the automatic software update feature. Please refer to
5452 documentation in doc/README.update for more details.
5454 autoload - if set to "no" (any string beginning with 'n'),
5455 "bootp" will just load perform a lookup of the
5456 configuration from the BOOTP server, but not try to
5457 load any image using TFTP
5459 autostart - if set to "yes", an image loaded using the "bootp",
5460 "rarpboot", "tftpboot" or "diskboot" commands will
5461 be automatically started (by internally calling
5464 If set to "no", a standalone image passed to the
5465 "bootm" command will be copied to the load address
5466 (and eventually uncompressed), but NOT be started.
5467 This can be used to load and uncompress arbitrary
5470 fdt_high - if set this restricts the maximum address that the
5471 flattened device tree will be copied into upon boot.
5472 For example, if you have a system with 1 GB memory
5473 at physical address 0x10000000, while Linux kernel
5474 only recognizes the first 704 MB as low memory, you
5475 may need to set fdt_high as 0x3C000000 to have the
5476 device tree blob be copied to the maximum address
5477 of the 704 MB low memory, so that Linux kernel can
5478 access it during the boot procedure.
5480 If this is set to the special value 0xFFFFFFFF then
5481 the fdt will not be copied at all on boot. For this
5482 to work it must reside in writable memory, have
5483 sufficient padding on the end of it for u-boot to
5484 add the information it needs into it, and the memory
5485 must be accessible by the kernel.
5487 fdtcontroladdr- if set this is the address of the control flattened
5488 device tree used by U-Boot when CONFIG_OF_CONTROL is
5491 i2cfast - (PPC405GP|PPC405EP only)
5492 if set to 'y' configures Linux I2C driver for fast
5493 mode (400kHZ). This environment variable is used in
5494 initialization code. So, for changes to be effective
5495 it must be saved and board must be reset.
5497 initrd_high - restrict positioning of initrd images:
5498 If this variable is not set, initrd images will be
5499 copied to the highest possible address in RAM; this
5500 is usually what you want since it allows for
5501 maximum initrd size. If for some reason you want to
5502 make sure that the initrd image is loaded below the
5503 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5504 variable to a value of "no" or "off" or "0".
5505 Alternatively, you can set it to a maximum upper
5506 address to use (U-Boot will still check that it
5507 does not overwrite the U-Boot stack and data).
5509 For instance, when you have a system with 16 MB
5510 RAM, and want to reserve 4 MB from use by Linux,
5511 you can do this by adding "mem=12M" to the value of
5512 the "bootargs" variable. However, now you must make
5513 sure that the initrd image is placed in the first
5514 12 MB as well - this can be done with
5516 setenv initrd_high 00c00000
5518 If you set initrd_high to 0xFFFFFFFF, this is an
5519 indication to U-Boot that all addresses are legal
5520 for the Linux kernel, including addresses in flash
5521 memory. In this case U-Boot will NOT COPY the
5522 ramdisk at all. This may be useful to reduce the
5523 boot time on your system, but requires that this
5524 feature is supported by your Linux kernel.
5526 ipaddr - IP address; needed for tftpboot command
5528 loadaddr - Default load address for commands like "bootp",
5529 "rarpboot", "tftpboot", "loadb" or "diskboot"
5531 loads_echo - see CONFIG_LOADS_ECHO
5533 serverip - TFTP server IP address; needed for tftpboot command
5535 bootretry - see CONFIG_BOOT_RETRY_TIME
5537 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5539 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5541 ethprime - controls which interface is used first.
5543 ethact - controls which interface is currently active.
5544 For example you can do the following
5546 => setenv ethact FEC
5547 => ping 192.168.0.1 # traffic sent on FEC
5548 => setenv ethact SCC
5549 => ping 10.0.0.1 # traffic sent on SCC
5551 ethrotate - When set to "no" U-Boot does not go through all
5552 available network interfaces.
5553 It just stays at the currently selected interface.
5555 netretry - When set to "no" each network operation will
5556 either succeed or fail without retrying.
5557 When set to "once" the network operation will
5558 fail when all the available network interfaces
5559 are tried once without success.
5560 Useful on scripts which control the retry operation
5563 npe_ucode - set load address for the NPE microcode
5565 silent_linux - If set then Linux will be told to boot silently, by
5566 changing the console to be empty. If "yes" it will be
5567 made silent. If "no" it will not be made silent. If
5568 unset, then it will be made silent if the U-Boot console
5571 tftpsrcport - If this is set, the value is used for TFTP's
5574 tftpdstport - If this is set, the value is used for TFTP's UDP
5575 destination port instead of the Well Know Port 69.
5577 tftpblocksize - Block size to use for TFTP transfers; if not set,
5578 we use the TFTP server's default block size
5580 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5581 seconds, minimum value is 1000 = 1 second). Defines
5582 when a packet is considered to be lost so it has to
5583 be retransmitted. The default is 5000 = 5 seconds.
5584 Lowering this value may make downloads succeed
5585 faster in networks with high packet loss rates or
5586 with unreliable TFTP servers.
5588 vlan - When set to a value < 4095 the traffic over
5589 Ethernet is encapsulated/received over 802.1q
5592 The following image location variables contain the location of images
5593 used in booting. The "Image" column gives the role of the image and is
5594 not an environment variable name. The other columns are environment
5595 variable names. "File Name" gives the name of the file on a TFTP
5596 server, "RAM Address" gives the location in RAM the image will be
5597 loaded to, and "Flash Location" gives the image's address in NOR
5598 flash or offset in NAND flash.
5600 *Note* - these variables don't have to be defined for all boards, some
5601 boards currently use other variables for these purposes, and some
5602 boards use these variables for other purposes.
5604 Image File Name RAM Address Flash Location
5605 ----- --------- ----------- --------------
5606 u-boot u-boot u-boot_addr_r u-boot_addr
5607 Linux kernel bootfile kernel_addr_r kernel_addr
5608 device tree blob fdtfile fdt_addr_r fdt_addr
5609 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5611 The following environment variables may be used and automatically
5612 updated by the network boot commands ("bootp" and "rarpboot"),
5613 depending the information provided by your boot server:
5615 bootfile - see above
5616 dnsip - IP address of your Domain Name Server
5617 dnsip2 - IP address of your secondary Domain Name Server
5618 gatewayip - IP address of the Gateway (Router) to use
5619 hostname - Target hostname
5621 netmask - Subnet Mask
5622 rootpath - Pathname of the root filesystem on the NFS server
5623 serverip - see above
5626 There are two special Environment Variables:
5628 serial# - contains hardware identification information such
5629 as type string and/or serial number
5630 ethaddr - Ethernet address
5632 These variables can be set only once (usually during manufacturing of
5633 the board). U-Boot refuses to delete or overwrite these variables
5634 once they have been set once.
5637 Further special Environment Variables:
5639 ver - Contains the U-Boot version string as printed
5640 with the "version" command. This variable is
5641 readonly (see CONFIG_VERSION_VARIABLE).
5644 Please note that changes to some configuration parameters may take
5645 only effect after the next boot (yes, that's just like Windoze :-).
5648 Callback functions for environment variables:
5649 ---------------------------------------------
5651 For some environment variables, the behavior of u-boot needs to change
5652 when their values are changed. This functionality allows functions to
5653 be associated with arbitrary variables. On creation, overwrite, or
5654 deletion, the callback will provide the opportunity for some side
5655 effect to happen or for the change to be rejected.
5657 The callbacks are named and associated with a function using the
5658 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5660 These callbacks are associated with variables in one of two ways. The
5661 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5662 in the board configuration to a string that defines a list of
5663 associations. The list must be in the following format:
5665 entry = variable_name[:callback_name]
5668 If the callback name is not specified, then the callback is deleted.
5669 Spaces are also allowed anywhere in the list.
5671 Callbacks can also be associated by defining the ".callbacks" variable
5672 with the same list format above. Any association in ".callbacks" will
5673 override any association in the static list. You can define
5674 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5675 ".callbacks" environment variable in the default or embedded environment.
5677 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5678 regular expression. This allows multiple variables to be connected to
5679 the same callback without explicitly listing them all out.
5682 Command Line Parsing:
5683 =====================
5685 There are two different command line parsers available with U-Boot:
5686 the old "simple" one, and the much more powerful "hush" shell:
5688 Old, simple command line parser:
5689 --------------------------------
5691 - supports environment variables (through setenv / saveenv commands)
5692 - several commands on one line, separated by ';'
5693 - variable substitution using "... ${name} ..." syntax
5694 - special characters ('$', ';') can be escaped by prefixing with '\',
5696 setenv bootcmd bootm \${address}
5697 - You can also escape text by enclosing in single apostrophes, for example:
5698 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5703 - similar to Bourne shell, with control structures like
5704 if...then...else...fi, for...do...done; while...do...done,
5705 until...do...done, ...
5706 - supports environment ("global") variables (through setenv / saveenv
5707 commands) and local shell variables (through standard shell syntax
5708 "name=value"); only environment variables can be used with "run"
5714 (1) If a command line (or an environment variable executed by a "run"
5715 command) contains several commands separated by semicolon, and
5716 one of these commands fails, then the remaining commands will be
5719 (2) If you execute several variables with one call to run (i. e.
5720 calling run with a list of variables as arguments), any failing
5721 command will cause "run" to terminate, i. e. the remaining
5722 variables are not executed.
5724 Note for Redundant Ethernet Interfaces:
5725 =======================================
5727 Some boards come with redundant Ethernet interfaces; U-Boot supports
5728 such configurations and is capable of automatic selection of a
5729 "working" interface when needed. MAC assignment works as follows:
5731 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5732 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5733 "eth1addr" (=>eth1), "eth2addr", ...
5735 If the network interface stores some valid MAC address (for instance
5736 in SROM), this is used as default address if there is NO correspon-
5737 ding setting in the environment; if the corresponding environment
5738 variable is set, this overrides the settings in the card; that means:
5740 o If the SROM has a valid MAC address, and there is no address in the
5741 environment, the SROM's address is used.
5743 o If there is no valid address in the SROM, and a definition in the
5744 environment exists, then the value from the environment variable is
5747 o If both the SROM and the environment contain a MAC address, and
5748 both addresses are the same, this MAC address is used.
5750 o If both the SROM and the environment contain a MAC address, and the
5751 addresses differ, the value from the environment is used and a
5754 o If neither SROM nor the environment contain a MAC address, an error
5755 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5756 a random, locally-assigned MAC is used.
5758 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5759 will be programmed into hardware as part of the initialization process. This
5760 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5761 The naming convention is as follows:
5762 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5767 U-Boot is capable of booting (and performing other auxiliary operations on)
5768 images in two formats:
5770 New uImage format (FIT)
5771 -----------------------
5773 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5774 to Flattened Device Tree). It allows the use of images with multiple
5775 components (several kernels, ramdisks, etc.), with contents protected by
5776 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5782 Old image format is based on binary files which can be basically anything,
5783 preceded by a special header; see the definitions in include/image.h for
5784 details; basically, the header defines the following image properties:
5786 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5787 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5788 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5789 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5791 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5792 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5793 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5794 * Compression Type (uncompressed, gzip, bzip2)
5800 The header is marked by a special Magic Number, and both the header
5801 and the data portions of the image are secured against corruption by
5808 Although U-Boot should support any OS or standalone application
5809 easily, the main focus has always been on Linux during the design of
5812 U-Boot includes many features that so far have been part of some
5813 special "boot loader" code within the Linux kernel. Also, any
5814 "initrd" images to be used are no longer part of one big Linux image;
5815 instead, kernel and "initrd" are separate images. This implementation
5816 serves several purposes:
5818 - the same features can be used for other OS or standalone
5819 applications (for instance: using compressed images to reduce the
5820 Flash memory footprint)
5822 - it becomes much easier to port new Linux kernel versions because
5823 lots of low-level, hardware dependent stuff are done by U-Boot
5825 - the same Linux kernel image can now be used with different "initrd"
5826 images; of course this also means that different kernel images can
5827 be run with the same "initrd". This makes testing easier (you don't
5828 have to build a new "zImage.initrd" Linux image when you just
5829 change a file in your "initrd"). Also, a field-upgrade of the
5830 software is easier now.
5836 Porting Linux to U-Boot based systems:
5837 ---------------------------------------
5839 U-Boot cannot save you from doing all the necessary modifications to
5840 configure the Linux device drivers for use with your target hardware
5841 (no, we don't intend to provide a full virtual machine interface to
5844 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5846 Just make sure your machine specific header file (for instance
5847 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5848 Information structure as we define in include/asm-<arch>/u-boot.h,
5849 and make sure that your definition of IMAP_ADDR uses the same value
5850 as your U-Boot configuration in CONFIG_SYS_IMMR.
5852 Note that U-Boot now has a driver model, a unified model for drivers.
5853 If you are adding a new driver, plumb it into driver model. If there
5854 is no uclass available, you are encouraged to create one. See
5858 Configuring the Linux kernel:
5859 -----------------------------
5861 No specific requirements for U-Boot. Make sure you have some root
5862 device (initial ramdisk, NFS) for your target system.
5865 Building a Linux Image:
5866 -----------------------
5868 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5869 not used. If you use recent kernel source, a new build target
5870 "uImage" will exist which automatically builds an image usable by
5871 U-Boot. Most older kernels also have support for a "pImage" target,
5872 which was introduced for our predecessor project PPCBoot and uses a
5873 100% compatible format.
5877 make TQM850L_defconfig
5882 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5883 encapsulate a compressed Linux kernel image with header information,
5884 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5886 * build a standard "vmlinux" kernel image (in ELF binary format):
5888 * convert the kernel into a raw binary image:
5890 ${CROSS_COMPILE}-objcopy -O binary \
5891 -R .note -R .comment \
5892 -S vmlinux linux.bin
5894 * compress the binary image:
5898 * package compressed binary image for U-Boot:
5900 mkimage -A ppc -O linux -T kernel -C gzip \
5901 -a 0 -e 0 -n "Linux Kernel Image" \
5902 -d linux.bin.gz uImage
5905 The "mkimage" tool can also be used to create ramdisk images for use
5906 with U-Boot, either separated from the Linux kernel image, or
5907 combined into one file. "mkimage" encapsulates the images with a 64
5908 byte header containing information about target architecture,
5909 operating system, image type, compression method, entry points, time
5910 stamp, CRC32 checksums, etc.
5912 "mkimage" can be called in two ways: to verify existing images and
5913 print the header information, or to build new images.
5915 In the first form (with "-l" option) mkimage lists the information
5916 contained in the header of an existing U-Boot image; this includes
5917 checksum verification:
5919 tools/mkimage -l image
5920 -l ==> list image header information
5922 The second form (with "-d" option) is used to build a U-Boot image
5923 from a "data file" which is used as image payload:
5925 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5926 -n name -d data_file image
5927 -A ==> set architecture to 'arch'
5928 -O ==> set operating system to 'os'
5929 -T ==> set image type to 'type'
5930 -C ==> set compression type 'comp'
5931 -a ==> set load address to 'addr' (hex)
5932 -e ==> set entry point to 'ep' (hex)
5933 -n ==> set image name to 'name'
5934 -d ==> use image data from 'datafile'
5936 Right now, all Linux kernels for PowerPC systems use the same load
5937 address (0x00000000), but the entry point address depends on the
5940 - 2.2.x kernels have the entry point at 0x0000000C,
5941 - 2.3.x and later kernels have the entry point at 0x00000000.
5943 So a typical call to build a U-Boot image would read:
5945 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5946 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5947 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5948 > examples/uImage.TQM850L
5949 Image Name: 2.4.4 kernel for TQM850L
5950 Created: Wed Jul 19 02:34:59 2000
5951 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5952 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5953 Load Address: 0x00000000
5954 Entry Point: 0x00000000
5956 To verify the contents of the image (or check for corruption):
5958 -> tools/mkimage -l examples/uImage.TQM850L
5959 Image Name: 2.4.4 kernel for TQM850L
5960 Created: Wed Jul 19 02:34:59 2000
5961 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5962 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5963 Load Address: 0x00000000
5964 Entry Point: 0x00000000
5966 NOTE: for embedded systems where boot time is critical you can trade
5967 speed for memory and install an UNCOMPRESSED image instead: this
5968 needs more space in Flash, but boots much faster since it does not
5969 need to be uncompressed:
5971 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5972 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5973 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5974 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5975 > examples/uImage.TQM850L-uncompressed
5976 Image Name: 2.4.4 kernel for TQM850L
5977 Created: Wed Jul 19 02:34:59 2000
5978 Image Type: PowerPC Linux Kernel Image (uncompressed)
5979 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5980 Load Address: 0x00000000
5981 Entry Point: 0x00000000
5984 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5985 when your kernel is intended to use an initial ramdisk:
5987 -> tools/mkimage -n 'Simple Ramdisk Image' \
5988 > -A ppc -O linux -T ramdisk -C gzip \
5989 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5990 Image Name: Simple Ramdisk Image
5991 Created: Wed Jan 12 14:01:50 2000
5992 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5993 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5994 Load Address: 0x00000000
5995 Entry Point: 0x00000000
5997 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5998 option performs the converse operation of the mkimage's second form (the "-d"
5999 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6002 tools/dumpimage -i image -T type -p position data_file
6003 -i ==> extract from the 'image' a specific 'data_file'
6004 -T ==> set image type to 'type'
6005 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6008 Installing a Linux Image:
6009 -------------------------
6011 To downloading a U-Boot image over the serial (console) interface,
6012 you must convert the image to S-Record format:
6014 objcopy -I binary -O srec examples/image examples/image.srec
6016 The 'objcopy' does not understand the information in the U-Boot
6017 image header, so the resulting S-Record file will be relative to
6018 address 0x00000000. To load it to a given address, you need to
6019 specify the target address as 'offset' parameter with the 'loads'
6022 Example: install the image to address 0x40100000 (which on the
6023 TQM8xxL is in the first Flash bank):
6025 => erase 40100000 401FFFFF
6031 ## Ready for S-Record download ...
6032 ~>examples/image.srec
6033 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6035 15989 15990 15991 15992
6036 [file transfer complete]
6038 ## Start Addr = 0x00000000
6041 You can check the success of the download using the 'iminfo' command;
6042 this includes a checksum verification so you can be sure no data
6043 corruption happened:
6047 ## Checking Image at 40100000 ...
6048 Image Name: 2.2.13 for initrd on TQM850L
6049 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6050 Data Size: 335725 Bytes = 327 kB = 0 MB
6051 Load Address: 00000000
6052 Entry Point: 0000000c
6053 Verifying Checksum ... OK
6059 The "bootm" command is used to boot an application that is stored in
6060 memory (RAM or Flash). In case of a Linux kernel image, the contents
6061 of the "bootargs" environment variable is passed to the kernel as
6062 parameters. You can check and modify this variable using the
6063 "printenv" and "setenv" commands:
6066 => printenv bootargs
6067 bootargs=root=/dev/ram
6069 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6071 => printenv bootargs
6072 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6075 ## Booting Linux kernel at 40020000 ...
6076 Image Name: 2.2.13 for NFS on TQM850L
6077 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6078 Data Size: 381681 Bytes = 372 kB = 0 MB
6079 Load Address: 00000000
6080 Entry Point: 0000000c
6081 Verifying Checksum ... OK
6082 Uncompressing Kernel Image ... OK
6083 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
6084 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6085 time_init: decrementer frequency = 187500000/60
6086 Calibrating delay loop... 49.77 BogoMIPS
6087 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6090 If you want to boot a Linux kernel with initial RAM disk, you pass
6091 the memory addresses of both the kernel and the initrd image (PPBCOOT
6092 format!) to the "bootm" command:
6094 => imi 40100000 40200000
6096 ## Checking Image at 40100000 ...
6097 Image Name: 2.2.13 for initrd on TQM850L
6098 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6099 Data Size: 335725 Bytes = 327 kB = 0 MB
6100 Load Address: 00000000
6101 Entry Point: 0000000c
6102 Verifying Checksum ... OK
6104 ## Checking Image at 40200000 ...
6105 Image Name: Simple Ramdisk Image
6106 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6107 Data Size: 566530 Bytes = 553 kB = 0 MB
6108 Load Address: 00000000
6109 Entry Point: 00000000
6110 Verifying Checksum ... OK
6112 => bootm 40100000 40200000
6113 ## Booting Linux kernel at 40100000 ...
6114 Image Name: 2.2.13 for initrd on TQM850L
6115 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6116 Data Size: 335725 Bytes = 327 kB = 0 MB
6117 Load Address: 00000000
6118 Entry Point: 0000000c
6119 Verifying Checksum ... OK
6120 Uncompressing Kernel Image ... OK
6121 ## Loading RAMDisk Image at 40200000 ...
6122 Image Name: Simple Ramdisk Image
6123 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6124 Data Size: 566530 Bytes = 553 kB = 0 MB
6125 Load Address: 00000000
6126 Entry Point: 00000000
6127 Verifying Checksum ... OK
6128 Loading Ramdisk ... OK
6129 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
6130 Boot arguments: root=/dev/ram
6131 time_init: decrementer frequency = 187500000/60
6132 Calibrating delay loop... 49.77 BogoMIPS
6134 RAMDISK: Compressed image found at block 0
6135 VFS: Mounted root (ext2 filesystem).
6139 Boot Linux and pass a flat device tree:
6142 First, U-Boot must be compiled with the appropriate defines. See the section
6143 titled "Linux Kernel Interface" above for a more in depth explanation. The
6144 following is an example of how to start a kernel and pass an updated
6150 oft=oftrees/mpc8540ads.dtb
6151 => tftp $oftaddr $oft
6152 Speed: 1000, full duplex
6154 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6155 Filename 'oftrees/mpc8540ads.dtb'.
6156 Load address: 0x300000
6159 Bytes transferred = 4106 (100a hex)
6160 => tftp $loadaddr $bootfile
6161 Speed: 1000, full duplex
6163 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6165 Load address: 0x200000
6166 Loading:############
6168 Bytes transferred = 1029407 (fb51f hex)
6173 => bootm $loadaddr - $oftaddr
6174 ## Booting image at 00200000 ...
6175 Image Name: Linux-2.6.17-dirty
6176 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6177 Data Size: 1029343 Bytes = 1005.2 kB
6178 Load Address: 00000000
6179 Entry Point: 00000000
6180 Verifying Checksum ... OK
6181 Uncompressing Kernel Image ... OK
6182 Booting using flat device tree at 0x300000
6183 Using MPC85xx ADS machine description
6184 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6188 More About U-Boot Image Types:
6189 ------------------------------
6191 U-Boot supports the following image types:
6193 "Standalone Programs" are directly runnable in the environment
6194 provided by U-Boot; it is expected that (if they behave
6195 well) you can continue to work in U-Boot after return from
6196 the Standalone Program.
6197 "OS Kernel Images" are usually images of some Embedded OS which
6198 will take over control completely. Usually these programs
6199 will install their own set of exception handlers, device
6200 drivers, set up the MMU, etc. - this means, that you cannot
6201 expect to re-enter U-Boot except by resetting the CPU.
6202 "RAMDisk Images" are more or less just data blocks, and their
6203 parameters (address, size) are passed to an OS kernel that is
6205 "Multi-File Images" contain several images, typically an OS
6206 (Linux) kernel image and one or more data images like
6207 RAMDisks. This construct is useful for instance when you want
6208 to boot over the network using BOOTP etc., where the boot
6209 server provides just a single image file, but you want to get
6210 for instance an OS kernel and a RAMDisk image.
6212 "Multi-File Images" start with a list of image sizes, each
6213 image size (in bytes) specified by an "uint32_t" in network
6214 byte order. This list is terminated by an "(uint32_t)0".
6215 Immediately after the terminating 0 follow the images, one by
6216 one, all aligned on "uint32_t" boundaries (size rounded up to
6217 a multiple of 4 bytes).
6219 "Firmware Images" are binary images containing firmware (like
6220 U-Boot or FPGA images) which usually will be programmed to
6223 "Script files" are command sequences that will be executed by
6224 U-Boot's command interpreter; this feature is especially
6225 useful when you configure U-Boot to use a real shell (hush)
6226 as command interpreter.
6228 Booting the Linux zImage:
6229 -------------------------
6231 On some platforms, it's possible to boot Linux zImage. This is done
6232 using the "bootz" command. The syntax of "bootz" command is the same
6233 as the syntax of "bootm" command.
6235 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6236 kernel with raw initrd images. The syntax is slightly different, the
6237 address of the initrd must be augmented by it's size, in the following
6238 format: "<initrd addres>:<initrd size>".
6244 One of the features of U-Boot is that you can dynamically load and
6245 run "standalone" applications, which can use some resources of
6246 U-Boot like console I/O functions or interrupt services.
6248 Two simple examples are included with the sources:
6253 'examples/hello_world.c' contains a small "Hello World" Demo
6254 application; it is automatically compiled when you build U-Boot.
6255 It's configured to run at address 0x00040004, so you can play with it
6259 ## Ready for S-Record download ...
6260 ~>examples/hello_world.srec
6261 1 2 3 4 5 6 7 8 9 10 11 ...
6262 [file transfer complete]
6264 ## Start Addr = 0x00040004
6266 => go 40004 Hello World! This is a test.
6267 ## Starting application at 0x00040004 ...
6278 Hit any key to exit ...
6280 ## Application terminated, rc = 0x0
6282 Another example, which demonstrates how to register a CPM interrupt
6283 handler with the U-Boot code, can be found in 'examples/timer.c'.
6284 Here, a CPM timer is set up to generate an interrupt every second.
6285 The interrupt service routine is trivial, just printing a '.'
6286 character, but this is just a demo program. The application can be
6287 controlled by the following keys:
6289 ? - print current values og the CPM Timer registers
6290 b - enable interrupts and start timer
6291 e - stop timer and disable interrupts
6292 q - quit application
6295 ## Ready for S-Record download ...
6296 ~>examples/timer.srec
6297 1 2 3 4 5 6 7 8 9 10 11 ...
6298 [file transfer complete]
6300 ## Start Addr = 0x00040004
6303 ## Starting application at 0x00040004 ...
6306 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6309 [q, b, e, ?] Set interval 1000000 us
6312 [q, b, e, ?] ........
6313 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6316 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6319 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6322 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6324 [q, b, e, ?] ...Stopping timer
6326 [q, b, e, ?] ## Application terminated, rc = 0x0
6332 Over time, many people have reported problems when trying to use the
6333 "minicom" terminal emulation program for serial download. I (wd)
6334 consider minicom to be broken, and recommend not to use it. Under
6335 Unix, I recommend to use C-Kermit for general purpose use (and
6336 especially for kermit binary protocol download ("loadb" command), and
6337 use "cu" for S-Record download ("loads" command). See
6338 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6339 for help with kermit.
6342 Nevertheless, if you absolutely want to use it try adding this
6343 configuration to your "File transfer protocols" section:
6345 Name Program Name U/D FullScr IO-Red. Multi
6346 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6347 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6353 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6354 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6356 Building requires a cross environment; it is known to work on
6357 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6358 need gmake since the Makefiles are not compatible with BSD make).
6359 Note that the cross-powerpc package does not install include files;
6360 attempting to build U-Boot will fail because <machine/ansi.h> is
6361 missing. This file has to be installed and patched manually:
6363 # cd /usr/pkg/cross/powerpc-netbsd/include
6365 # ln -s powerpc machine
6366 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6367 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6369 Native builds *don't* work due to incompatibilities between native
6370 and U-Boot include files.
6372 Booting assumes that (the first part of) the image booted is a
6373 stage-2 loader which in turn loads and then invokes the kernel
6374 proper. Loader sources will eventually appear in the NetBSD source
6375 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6376 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6379 Implementation Internals:
6380 =========================
6382 The following is not intended to be a complete description of every
6383 implementation detail. However, it should help to understand the
6384 inner workings of U-Boot and make it easier to port it to custom
6388 Initial Stack, Global Data:
6389 ---------------------------
6391 The implementation of U-Boot is complicated by the fact that U-Boot
6392 starts running out of ROM (flash memory), usually without access to
6393 system RAM (because the memory controller is not initialized yet).
6394 This means that we don't have writable Data or BSS segments, and BSS
6395 is not initialized as zero. To be able to get a C environment working
6396 at all, we have to allocate at least a minimal stack. Implementation
6397 options for this are defined and restricted by the CPU used: Some CPU
6398 models provide on-chip memory (like the IMMR area on MPC8xx and
6399 MPC826x processors), on others (parts of) the data cache can be
6400 locked as (mis-) used as memory, etc.
6402 Chris Hallinan posted a good summary of these issues to the
6403 U-Boot mailing list:
6405 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6406 From: "Chris Hallinan" <clh@net1plus.com>
6407 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6410 Correct me if I'm wrong, folks, but the way I understand it
6411 is this: Using DCACHE as initial RAM for Stack, etc, does not
6412 require any physical RAM backing up the cache. The cleverness
6413 is that the cache is being used as a temporary supply of
6414 necessary storage before the SDRAM controller is setup. It's
6415 beyond the scope of this list to explain the details, but you
6416 can see how this works by studying the cache architecture and
6417 operation in the architecture and processor-specific manuals.
6419 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6420 is another option for the system designer to use as an
6421 initial stack/RAM area prior to SDRAM being available. Either
6422 option should work for you. Using CS 4 should be fine if your
6423 board designers haven't used it for something that would
6424 cause you grief during the initial boot! It is frequently not
6427 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6428 with your processor/board/system design. The default value
6429 you will find in any recent u-boot distribution in
6430 walnut.h should work for you. I'd set it to a value larger
6431 than your SDRAM module. If you have a 64MB SDRAM module, set
6432 it above 400_0000. Just make sure your board has no resources
6433 that are supposed to respond to that address! That code in
6434 start.S has been around a while and should work as is when
6435 you get the config right.
6440 It is essential to remember this, since it has some impact on the C
6441 code for the initialization procedures:
6443 * Initialized global data (data segment) is read-only. Do not attempt
6446 * Do not use any uninitialized global data (or implicitly initialized
6447 as zero data - BSS segment) at all - this is undefined, initiali-
6448 zation is performed later (when relocating to RAM).
6450 * Stack space is very limited. Avoid big data buffers or things like
6453 Having only the stack as writable memory limits means we cannot use
6454 normal global data to share information between the code. But it
6455 turned out that the implementation of U-Boot can be greatly
6456 simplified by making a global data structure (gd_t) available to all
6457 functions. We could pass a pointer to this data as argument to _all_
6458 functions, but this would bloat the code. Instead we use a feature of
6459 the GCC compiler (Global Register Variables) to share the data: we
6460 place a pointer (gd) to the global data into a register which we
6461 reserve for this purpose.
6463 When choosing a register for such a purpose we are restricted by the
6464 relevant (E)ABI specifications for the current architecture, and by
6465 GCC's implementation.
6467 For PowerPC, the following registers have specific use:
6469 R2: reserved for system use
6470 R3-R4: parameter passing and return values
6471 R5-R10: parameter passing
6472 R13: small data area pointer
6476 (U-Boot also uses R12 as internal GOT pointer. r12
6477 is a volatile register so r12 needs to be reset when
6478 going back and forth between asm and C)
6480 ==> U-Boot will use R2 to hold a pointer to the global data
6482 Note: on PPC, we could use a static initializer (since the
6483 address of the global data structure is known at compile time),
6484 but it turned out that reserving a register results in somewhat
6485 smaller code - although the code savings are not that big (on
6486 average for all boards 752 bytes for the whole U-Boot image,
6487 624 text + 127 data).
6489 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6490 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6492 ==> U-Boot will use P3 to hold a pointer to the global data
6494 On ARM, the following registers are used:
6496 R0: function argument word/integer result
6497 R1-R3: function argument word
6498 R9: platform specific
6499 R10: stack limit (used only if stack checking is enabled)
6500 R11: argument (frame) pointer
6501 R12: temporary workspace
6504 R15: program counter
6506 ==> U-Boot will use R9 to hold a pointer to the global data
6508 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6510 On Nios II, the ABI is documented here:
6511 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6513 ==> U-Boot will use gp to hold a pointer to the global data
6515 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6516 to access small data sections, so gp is free.
6518 On NDS32, the following registers are used:
6520 R0-R1: argument/return
6522 R15: temporary register for assembler
6523 R16: trampoline register
6524 R28: frame pointer (FP)
6525 R29: global pointer (GP)
6526 R30: link register (LP)
6527 R31: stack pointer (SP)
6528 PC: program counter (PC)
6530 ==> U-Boot will use R10 to hold a pointer to the global data
6532 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6533 or current versions of GCC may "optimize" the code too much.
6538 U-Boot runs in system state and uses physical addresses, i.e. the
6539 MMU is not used either for address mapping nor for memory protection.
6541 The available memory is mapped to fixed addresses using the memory
6542 controller. In this process, a contiguous block is formed for each
6543 memory type (Flash, SDRAM, SRAM), even when it consists of several
6544 physical memory banks.
6546 U-Boot is installed in the first 128 kB of the first Flash bank (on
6547 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6548 booting and sizing and initializing DRAM, the code relocates itself
6549 to the upper end of DRAM. Immediately below the U-Boot code some
6550 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6551 configuration setting]. Below that, a structure with global Board
6552 Info data is placed, followed by the stack (growing downward).
6554 Additionally, some exception handler code is copied to the low 8 kB
6555 of DRAM (0x00000000 ... 0x00001FFF).
6557 So a typical memory configuration with 16 MB of DRAM could look like
6560 0x0000 0000 Exception Vector code
6563 0x0000 2000 Free for Application Use
6569 0x00FB FF20 Monitor Stack (Growing downward)
6570 0x00FB FFAC Board Info Data and permanent copy of global data
6571 0x00FC 0000 Malloc Arena
6574 0x00FE 0000 RAM Copy of Monitor Code
6575 ... eventually: LCD or video framebuffer
6576 ... eventually: pRAM (Protected RAM - unchanged by reset)
6577 0x00FF FFFF [End of RAM]
6580 System Initialization:
6581 ----------------------
6583 In the reset configuration, U-Boot starts at the reset entry point
6584 (on most PowerPC systems at address 0x00000100). Because of the reset
6585 configuration for CS0# this is a mirror of the on board Flash memory.
6586 To be able to re-map memory U-Boot then jumps to its link address.
6587 To be able to implement the initialization code in C, a (small!)
6588 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6589 which provide such a feature like MPC8xx or MPC8260), or in a locked
6590 part of the data cache. After that, U-Boot initializes the CPU core,
6591 the caches and the SIU.
6593 Next, all (potentially) available memory banks are mapped using a
6594 preliminary mapping. For example, we put them on 512 MB boundaries
6595 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6596 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6597 programmed for SDRAM access. Using the temporary configuration, a
6598 simple memory test is run that determines the size of the SDRAM
6601 When there is more than one SDRAM bank, and the banks are of
6602 different size, the largest is mapped first. For equal size, the first
6603 bank (CS2#) is mapped first. The first mapping is always for address
6604 0x00000000, with any additional banks following immediately to create
6605 contiguous memory starting from 0.
6607 Then, the monitor installs itself at the upper end of the SDRAM area
6608 and allocates memory for use by malloc() and for the global Board
6609 Info data; also, the exception vector code is copied to the low RAM
6610 pages, and the final stack is set up.
6612 Only after this relocation will you have a "normal" C environment;
6613 until that you are restricted in several ways, mostly because you are
6614 running from ROM, and because the code will have to be relocated to a
6618 U-Boot Porting Guide:
6619 ----------------------
6621 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6625 int main(int argc, char *argv[])
6627 sighandler_t no_more_time;
6629 signal(SIGALRM, no_more_time);
6630 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6632 if (available_money > available_manpower) {
6633 Pay consultant to port U-Boot;
6637 Download latest U-Boot source;
6639 Subscribe to u-boot mailing list;
6642 email("Hi, I am new to U-Boot, how do I get started?");
6645 Read the README file in the top level directory;
6646 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6647 Read applicable doc/*.README;
6648 Read the source, Luke;
6649 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6652 if (available_money > toLocalCurrency ($2500))
6655 Add a lot of aggravation and time;
6657 if (a similar board exists) { /* hopefully... */
6658 cp -a board/<similar> board/<myboard>
6659 cp include/configs/<similar>.h include/configs/<myboard>.h
6661 Create your own board support subdirectory;
6662 Create your own board include/configs/<myboard>.h file;
6664 Edit new board/<myboard> files
6665 Edit new include/configs/<myboard>.h
6670 Add / modify source code;
6674 email("Hi, I am having problems...");
6676 Send patch file to the U-Boot email list;
6677 if (reasonable critiques)
6678 Incorporate improvements from email list code review;
6680 Defend code as written;
6686 void no_more_time (int sig)
6695 All contributions to U-Boot should conform to the Linux kernel
6696 coding style; see the file "Documentation/CodingStyle" and the script
6697 "scripts/Lindent" in your Linux kernel source directory.
6699 Source files originating from a different project (for example the
6700 MTD subsystem) are generally exempt from these guidelines and are not
6701 reformatted to ease subsequent migration to newer versions of those
6704 Please note that U-Boot is implemented in C (and to some small parts in
6705 Assembler); no C++ is used, so please do not use C++ style comments (//)
6708 Please also stick to the following formatting rules:
6709 - remove any trailing white space
6710 - use TAB characters for indentation and vertical alignment, not spaces
6711 - make sure NOT to use DOS '\r\n' line feeds
6712 - do not add more than 2 consecutive empty lines to source files
6713 - do not add trailing empty lines to source files
6715 Submissions which do not conform to the standards may be returned
6716 with a request to reformat the changes.
6722 Since the number of patches for U-Boot is growing, we need to
6723 establish some rules. Submissions which do not conform to these rules
6724 may be rejected, even when they contain important and valuable stuff.
6726 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6728 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6729 see http://lists.denx.de/mailman/listinfo/u-boot
6731 When you send a patch, please include the following information with
6734 * For bug fixes: a description of the bug and how your patch fixes
6735 this bug. Please try to include a way of demonstrating that the
6736 patch actually fixes something.
6738 * For new features: a description of the feature and your
6741 * A CHANGELOG entry as plaintext (separate from the patch)
6743 * For major contributions, your entry to the CREDITS file
6745 * When you add support for a new board, don't forget to add a
6746 maintainer e-mail address to the boards.cfg file, too.
6748 * If your patch adds new configuration options, don't forget to
6749 document these in the README file.
6751 * The patch itself. If you are using git (which is *strongly*
6752 recommended) you can easily generate the patch using the
6753 "git format-patch". If you then use "git send-email" to send it to
6754 the U-Boot mailing list, you will avoid most of the common problems
6755 with some other mail clients.
6757 If you cannot use git, use "diff -purN OLD NEW". If your version of
6758 diff does not support these options, then get the latest version of
6761 The current directory when running this command shall be the parent
6762 directory of the U-Boot source tree (i. e. please make sure that
6763 your patch includes sufficient directory information for the
6766 We prefer patches as plain text. MIME attachments are discouraged,
6767 and compressed attachments must not be used.
6769 * If one logical set of modifications affects or creates several
6770 files, all these changes shall be submitted in a SINGLE patch file.
6772 * Changesets that contain different, unrelated modifications shall be
6773 submitted as SEPARATE patches, one patch per changeset.
6778 * Before sending the patch, run the MAKEALL script on your patched
6779 source tree and make sure that no errors or warnings are reported
6780 for any of the boards.
6782 * Keep your modifications to the necessary minimum: A patch
6783 containing several unrelated changes or arbitrary reformats will be
6784 returned with a request to re-formatting / split it.
6786 * If you modify existing code, make sure that your new code does not
6787 add to the memory footprint of the code ;-) Small is beautiful!
6788 When adding new features, these should compile conditionally only
6789 (using #ifdef), and the resulting code with the new feature
6790 disabled must not need more memory than the old code without your
6793 * Remember that there is a size limit of 100 kB per message on the
6794 u-boot mailing list. Bigger patches will be moderated. If they are
6795 reasonable and not too big, they will be acknowledged. But patches
6796 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob