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 CONFIG_TEGRA_SUPPORT_NON_SECURE
696 Support executing U-Boot in non-secure (NS) mode. Certain
697 impossible actions will be skipped if the CPU is in NS mode,
698 such as ARM architectural timer initialization.
701 Driver model is a new framework for devices in U-Boot
702 introduced in early 2014. U-Boot is being progressively
703 moved over to this. It offers a consistent device structure,
704 supports grouping devices into classes and has built-in
705 handling of platform data and device tree.
707 To enable transition to driver model in a relatively
708 painful fashion, each subsystem can be independently
709 switched between the legacy/ad-hoc approach and the new
710 driver model using the options below. Also, many uclass
711 interfaces include compatibility features which may be
712 removed once the conversion of that subsystem is complete.
713 As a result, the API provided by the subsystem may in fact
714 not change with driver model.
716 See doc/driver-model/README.txt for more information.
720 Enable driver model. This brings in the core support,
721 including scanning of platform data on start-up. If
722 CONFIG_OF_CONTROL is enabled, the device tree will be
723 scanned also when available.
727 Enable driver model test commands. These allow you to print
728 out the driver model tree and the uclasses.
732 Enable some demo devices and the 'demo' command. These are
733 really only useful for playing around while trying to
734 understand driver model in sandbox.
738 Enable driver model in SPL. You will need to provide a
739 suitable malloc() implementation. If you are not using the
740 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
741 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
742 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
743 In most cases driver model will only allocate a few uclasses
744 and devices in SPL, so 1KB should be enable. See
745 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
750 Enable driver model for serial. This replaces
751 drivers/serial/serial.c with the serial uclass, which
752 implements serial_putc() etc. The uclass interface is
753 defined in include/serial.h.
757 Enable driver model for GPIO access. The standard GPIO
758 interface (gpio_get_value(), etc.) is then implemented by
759 the GPIO uclass. Drivers provide methods to query the
760 particular GPIOs that they provide. The uclass interface
761 is defined in include/asm-generic/gpio.h.
765 Enable driver model for SPI. The SPI slave interface
766 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
767 the SPI uclass. Drivers provide methods to access the SPI
768 buses that they control. The uclass interface is defined in
769 include/spi.h. The existing spi_slave structure is attached
770 as 'parent data' to every slave on each bus. Slaves
771 typically use driver-private data instead of extending the
776 Enable driver model for SPI flash. This SPI flash interface
777 (spi_flash_probe(), spi_flash_write(), etc.) is then
778 implemented by the SPI flash uclass. There is one standard
779 SPI flash driver which knows how to probe most chips
780 supported by U-Boot. The uclass interface is defined in
781 include/spi_flash.h, but is currently fully compatible
782 with the old interface to avoid confusion and duplication
783 during the transition parent. SPI and SPI flash must be
784 enabled together (it is not possible to use driver model
785 for one and not the other).
789 Enable driver model for the Chrome OS EC interface. This
790 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
791 but otherwise makes few changes. Since cros_ec also supports
792 I2C and LPC (which don't support driver model yet), a full
793 conversion is not yet possible.
796 ** Code size options: The following options are enabled by
797 default except in SPL. Enable them explicitly to get these
802 Enable the dm_warn() function. This can use up quite a bit
803 of space for its strings.
807 Enable registering a serial device with the stdio library.
809 CONFIG_DM_DEVICE_REMOVE
811 Enable removing of devices.
814 - Linux Kernel Interface:
817 U-Boot stores all clock information in Hz
818 internally. For binary compatibility with older Linux
819 kernels (which expect the clocks passed in the
820 bd_info data to be in MHz) the environment variable
821 "clocks_in_mhz" can be defined so that U-Boot
822 converts clock data to MHZ before passing it to the
824 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
825 "clocks_in_mhz=1" is automatically included in the
828 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
830 When transferring memsize parameter to Linux, some versions
831 expect it to be in bytes, others in MB.
832 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
836 New kernel versions are expecting firmware settings to be
837 passed using flattened device trees (based on open firmware
841 * New libfdt-based support
842 * Adds the "fdt" command
843 * The bootm command automatically updates the fdt
845 OF_CPU - The proper name of the cpus node (only required for
846 MPC512X and MPC5xxx based boards).
847 OF_SOC - The proper name of the soc node (only required for
848 MPC512X and MPC5xxx based boards).
849 OF_TBCLK - The timebase frequency.
850 OF_STDOUT_PATH - The path to the console device
852 boards with QUICC Engines require OF_QE to set UCC MAC
855 CONFIG_OF_BOARD_SETUP
857 Board code has addition modification that it wants to make
858 to the flat device tree before handing it off to the kernel
860 CONFIG_OF_SYSTEM_SETUP
862 Other code has addition modification that it wants to make
863 to the flat device tree before handing it off to the kernel.
864 This causes ft_system_setup() to be called before booting
869 This define fills in the correct boot CPU in the boot
870 param header, the default value is zero if undefined.
874 U-Boot can detect if an IDE device is present or not.
875 If not, and this new config option is activated, U-Boot
876 removes the ATA node from the DTS before booting Linux,
877 so the Linux IDE driver does not probe the device and
878 crash. This is needed for buggy hardware (uc101) where
879 no pull down resistor is connected to the signal IDE5V_DD7.
881 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
883 This setting is mandatory for all boards that have only one
884 machine type and must be used to specify the machine type
885 number as it appears in the ARM machine registry
886 (see http://www.arm.linux.org.uk/developer/machines/).
887 Only boards that have multiple machine types supported
888 in a single configuration file and the machine type is
889 runtime discoverable, do not have to use this setting.
891 - vxWorks boot parameters:
893 bootvx constructs a valid bootline using the following
894 environments variables: bootfile, ipaddr, serverip, hostname.
895 It loads the vxWorks image pointed bootfile.
897 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
898 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
899 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
900 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
902 CONFIG_SYS_VXWORKS_ADD_PARAMS
904 Add it at the end of the bootline. E.g "u=username pw=secret"
906 Note: If a "bootargs" environment is defined, it will overwride
907 the defaults discussed just above.
909 - Cache Configuration:
910 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
911 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
912 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
914 - Cache Configuration for ARM:
915 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
917 CONFIG_SYS_PL310_BASE - Physical base address of PL310
918 controller register space
923 Define this if you want support for Amba PrimeCell PL010 UARTs.
927 Define this if you want support for Amba PrimeCell PL011 UARTs.
931 If you have Amba PrimeCell PL011 UARTs, set this variable to
932 the clock speed of the UARTs.
936 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
937 define this to a list of base addresses for each (supported)
938 port. See e.g. include/configs/versatile.h
940 CONFIG_PL011_SERIAL_RLCR
942 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
943 have separate receive and transmit line control registers. Set
944 this variable to initialize the extra register.
946 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
948 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
949 boot loader that has already initialized the UART. Define this
950 variable to flush the UART at init time.
952 CONFIG_SERIAL_HW_FLOW_CONTROL
954 Define this variable to enable hw flow control in serial driver.
955 Current user of this option is drivers/serial/nsl16550.c driver
958 Depending on board, define exactly one serial port
959 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
960 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
961 console by defining CONFIG_8xx_CONS_NONE
963 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
964 port routines must be defined elsewhere
965 (i.e. serial_init(), serial_getc(), ...)
968 Enables console device for a color framebuffer. Needs following
969 defines (cf. smiLynxEM, i8042)
970 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
972 VIDEO_HW_RECTFILL graphic chip supports
975 VIDEO_HW_BITBLT graphic chip supports
976 bit-blit (cf. smiLynxEM)
977 VIDEO_VISIBLE_COLS visible pixel columns
979 VIDEO_VISIBLE_ROWS visible pixel rows
980 VIDEO_PIXEL_SIZE bytes per pixel
981 VIDEO_DATA_FORMAT graphic data format
982 (0-5, cf. cfb_console.c)
983 VIDEO_FB_ADRS framebuffer address
984 VIDEO_KBD_INIT_FCT keyboard int fct
985 (i.e. i8042_kbd_init())
986 VIDEO_TSTC_FCT test char fct
988 VIDEO_GETC_FCT get char fct
990 CONFIG_CONSOLE_CURSOR cursor drawing on/off
991 (requires blink timer
993 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
994 CONFIG_CONSOLE_TIME display time/date info in
996 (requires CONFIG_CMD_DATE)
997 CONFIG_VIDEO_LOGO display Linux logo in
999 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1000 linux_logo.h for logo.
1001 Requires CONFIG_VIDEO_LOGO
1002 CONFIG_CONSOLE_EXTRA_INFO
1003 additional board info beside
1006 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1007 a limited number of ANSI escape sequences (cursor control,
1008 erase functions and limited graphics rendition control).
1010 When CONFIG_CFB_CONSOLE is defined, video console is
1011 default i/o. Serial console can be forced with
1012 environment 'console=serial'.
1014 When CONFIG_SILENT_CONSOLE is defined, all console
1015 messages (by U-Boot and Linux!) can be silenced with
1016 the "silent" environment variable. See
1017 doc/README.silent for more information.
1019 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1021 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1025 CONFIG_BAUDRATE - in bps
1026 Select one of the baudrates listed in
1027 CONFIG_SYS_BAUDRATE_TABLE, see below.
1028 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1030 - Console Rx buffer length
1031 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1032 the maximum receive buffer length for the SMC.
1033 This option is actual only for 82xx and 8xx possible.
1034 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1035 must be defined, to setup the maximum idle timeout for
1038 - Pre-Console Buffer:
1039 Prior to the console being initialised (i.e. serial UART
1040 initialised etc) all console output is silently discarded.
1041 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1042 buffer any console messages prior to the console being
1043 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1044 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1045 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1046 bytes are output before the console is initialised, the
1047 earlier bytes are discarded.
1049 'Sane' compilers will generate smaller code if
1050 CONFIG_PRE_CON_BUF_SZ is a power of 2
1052 - Safe printf() functions
1053 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1054 the printf() functions. These are defined in
1055 include/vsprintf.h and include snprintf(), vsnprintf() and
1056 so on. Code size increase is approximately 300-500 bytes.
1057 If this option is not given then these functions will
1058 silently discard their buffer size argument - this means
1059 you are not getting any overflow checking in this case.
1061 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1062 Delay before automatically booting the default image;
1063 set to -1 to disable autoboot.
1064 set to -2 to autoboot with no delay and not check for abort
1065 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1067 See doc/README.autoboot for these options that
1068 work with CONFIG_BOOTDELAY. None are required.
1069 CONFIG_BOOT_RETRY_TIME
1070 CONFIG_BOOT_RETRY_MIN
1071 CONFIG_AUTOBOOT_KEYED
1072 CONFIG_AUTOBOOT_PROMPT
1073 CONFIG_AUTOBOOT_DELAY_STR
1074 CONFIG_AUTOBOOT_STOP_STR
1075 CONFIG_AUTOBOOT_DELAY_STR2
1076 CONFIG_AUTOBOOT_STOP_STR2
1077 CONFIG_ZERO_BOOTDELAY_CHECK
1078 CONFIG_RESET_TO_RETRY
1082 Only needed when CONFIG_BOOTDELAY is enabled;
1083 define a command string that is automatically executed
1084 when no character is read on the console interface
1085 within "Boot Delay" after reset.
1088 This can be used to pass arguments to the bootm
1089 command. The value of CONFIG_BOOTARGS goes into the
1090 environment value "bootargs".
1092 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1093 The value of these goes into the environment as
1094 "ramboot" and "nfsboot" respectively, and can be used
1095 as a convenience, when switching between booting from
1099 CONFIG_BOOTCOUNT_LIMIT
1100 Implements a mechanism for detecting a repeating reboot
1102 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1104 CONFIG_BOOTCOUNT_ENV
1105 If no softreset save registers are found on the hardware
1106 "bootcount" is stored in the environment. To prevent a
1107 saveenv on all reboots, the environment variable
1108 "upgrade_available" is used. If "upgrade_available" is
1109 0, "bootcount" is always 0, if "upgrade_available" is
1110 1 "bootcount" is incremented in the environment.
1111 So the Userspace Applikation must set the "upgrade_available"
1112 and "bootcount" variable to 0, if a boot was successfully.
1114 - Pre-Boot Commands:
1117 When this option is #defined, the existence of the
1118 environment variable "preboot" will be checked
1119 immediately before starting the CONFIG_BOOTDELAY
1120 countdown and/or running the auto-boot command resp.
1121 entering interactive mode.
1123 This feature is especially useful when "preboot" is
1124 automatically generated or modified. For an example
1125 see the LWMON board specific code: here "preboot" is
1126 modified when the user holds down a certain
1127 combination of keys on the (special) keyboard when
1130 - Serial Download Echo Mode:
1132 If defined to 1, all characters received during a
1133 serial download (using the "loads" command) are
1134 echoed back. This might be needed by some terminal
1135 emulations (like "cu"), but may as well just take
1136 time on others. This setting #define's the initial
1137 value of the "loads_echo" environment variable.
1139 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1140 CONFIG_KGDB_BAUDRATE
1141 Select one of the baudrates listed in
1142 CONFIG_SYS_BAUDRATE_TABLE, see below.
1144 - Monitor Functions:
1145 Monitor commands can be included or excluded
1146 from the build by using the #include files
1147 <config_cmd_all.h> and #undef'ing unwanted
1148 commands, or using <config_cmd_default.h>
1149 and augmenting with additional #define's
1150 for wanted commands.
1152 The default command configuration includes all commands
1153 except those marked below with a "*".
1155 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1156 CONFIG_CMD_ASKENV * ask for env variable
1157 CONFIG_CMD_BDI bdinfo
1158 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1159 CONFIG_CMD_BMP * BMP support
1160 CONFIG_CMD_BSP * Board specific commands
1161 CONFIG_CMD_BOOTD bootd
1162 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1163 CONFIG_CMD_CACHE * icache, dcache
1164 CONFIG_CMD_CLK * clock command support
1165 CONFIG_CMD_CONSOLE coninfo
1166 CONFIG_CMD_CRC32 * crc32
1167 CONFIG_CMD_DATE * support for RTC, date/time...
1168 CONFIG_CMD_DHCP * DHCP support
1169 CONFIG_CMD_DIAG * Diagnostics
1170 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1171 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1172 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1173 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1174 CONFIG_CMD_DTT * Digital Therm and Thermostat
1175 CONFIG_CMD_ECHO echo arguments
1176 CONFIG_CMD_EDITENV edit env variable
1177 CONFIG_CMD_EEPROM * EEPROM read/write support
1178 CONFIG_CMD_ELF * bootelf, bootvx
1179 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1180 CONFIG_CMD_ENV_FLAGS * display details about env flags
1181 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1182 CONFIG_CMD_EXPORTENV * export the environment
1183 CONFIG_CMD_EXT2 * ext2 command support
1184 CONFIG_CMD_EXT4 * ext4 command support
1185 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1186 that work for multiple fs types
1187 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1188 CONFIG_CMD_SAVEENV saveenv
1189 CONFIG_CMD_FDC * Floppy Disk Support
1190 CONFIG_CMD_FAT * FAT command support
1191 CONFIG_CMD_FLASH flinfo, erase, protect
1192 CONFIG_CMD_FPGA FPGA device initialization support
1193 CONFIG_CMD_FUSE * Device fuse support
1194 CONFIG_CMD_GETTIME * Get time since boot
1195 CONFIG_CMD_GO * the 'go' command (exec code)
1196 CONFIG_CMD_GREPENV * search environment
1197 CONFIG_CMD_HASH * calculate hash / digest
1198 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1199 CONFIG_CMD_I2C * I2C serial bus support
1200 CONFIG_CMD_IDE * IDE harddisk support
1201 CONFIG_CMD_IMI iminfo
1202 CONFIG_CMD_IMLS List all images found in NOR flash
1203 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1204 CONFIG_CMD_IMMAP * IMMR dump support
1205 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1206 CONFIG_CMD_IMPORTENV * import an environment
1207 CONFIG_CMD_INI * import data from an ini file into the env
1208 CONFIG_CMD_IRQ * irqinfo
1209 CONFIG_CMD_ITEST Integer/string test of 2 values
1210 CONFIG_CMD_JFFS2 * JFFS2 Support
1211 CONFIG_CMD_KGDB * kgdb
1212 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1213 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1215 CONFIG_CMD_LOADB loadb
1216 CONFIG_CMD_LOADS loads
1217 CONFIG_CMD_MD5SUM * print md5 message digest
1218 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1219 CONFIG_CMD_MEMINFO * Display detailed memory information
1220 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1222 CONFIG_CMD_MEMTEST * mtest
1223 CONFIG_CMD_MISC Misc functions like sleep etc
1224 CONFIG_CMD_MMC * MMC memory mapped support
1225 CONFIG_CMD_MII * MII utility commands
1226 CONFIG_CMD_MTDPARTS * MTD partition support
1227 CONFIG_CMD_NAND * NAND support
1228 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1229 CONFIG_CMD_NFS NFS support
1230 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1231 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1232 CONFIG_CMD_PCI * pciinfo
1233 CONFIG_CMD_PCMCIA * PCMCIA support
1234 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1236 CONFIG_CMD_PORTIO * Port I/O
1237 CONFIG_CMD_READ * Read raw data from partition
1238 CONFIG_CMD_REGINFO * Register dump
1239 CONFIG_CMD_RUN run command in env variable
1240 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1241 CONFIG_CMD_SAVES * save S record dump
1242 CONFIG_CMD_SCSI * SCSI Support
1243 CONFIG_CMD_SDRAM * print SDRAM configuration information
1244 (requires CONFIG_CMD_I2C)
1245 CONFIG_CMD_SETGETDCR Support for DCR Register access
1247 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1248 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1249 (requires CONFIG_CMD_MEMORY)
1250 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1251 CONFIG_CMD_SOURCE "source" command Support
1252 CONFIG_CMD_SPI * SPI serial bus support
1253 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1254 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1255 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1256 CONFIG_CMD_TIMER * access to the system tick timer
1257 CONFIG_CMD_USB * USB support
1258 CONFIG_CMD_CDP * Cisco Discover Protocol support
1259 CONFIG_CMD_MFSL * Microblaze FSL support
1260 CONFIG_CMD_XIMG Load part of Multi Image
1261 CONFIG_CMD_UUID * Generate random UUID or GUID string
1263 EXAMPLE: If you want all functions except of network
1264 support you can write:
1266 #include "config_cmd_all.h"
1267 #undef CONFIG_CMD_NET
1270 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1272 Note: Don't enable the "icache" and "dcache" commands
1273 (configuration option CONFIG_CMD_CACHE) unless you know
1274 what you (and your U-Boot users) are doing. Data
1275 cache cannot be enabled on systems like the 8xx or
1276 8260 (where accesses to the IMMR region must be
1277 uncached), and it cannot be disabled on all other
1278 systems where we (mis-) use the data cache to hold an
1279 initial stack and some data.
1282 XXX - this list needs to get updated!
1284 - Regular expression support:
1286 If this variable is defined, U-Boot is linked against
1287 the SLRE (Super Light Regular Expression) library,
1288 which adds regex support to some commands, as for
1289 example "env grep" and "setexpr".
1293 If this variable is defined, U-Boot will use a device tree
1294 to configure its devices, instead of relying on statically
1295 compiled #defines in the board file. This option is
1296 experimental and only available on a few boards. The device
1297 tree is available in the global data as gd->fdt_blob.
1299 U-Boot needs to get its device tree from somewhere. This can
1300 be done using one of the two options below:
1303 If this variable is defined, U-Boot will embed a device tree
1304 binary in its image. This device tree file should be in the
1305 board directory and called <soc>-<board>.dts. The binary file
1306 is then picked up in board_init_f() and made available through
1307 the global data structure as gd->blob.
1310 If this variable is defined, U-Boot will build a device tree
1311 binary. It will be called u-boot.dtb. Architecture-specific
1312 code will locate it at run-time. Generally this works by:
1314 cat u-boot.bin u-boot.dtb >image.bin
1316 and in fact, U-Boot does this for you, creating a file called
1317 u-boot-dtb.bin which is useful in the common case. You can
1318 still use the individual files if you need something more
1323 If this variable is defined, it enables watchdog
1324 support for the SoC. There must be support in the SoC
1325 specific code for a watchdog. For the 8xx and 8260
1326 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1327 register. When supported for a specific SoC is
1328 available, then no further board specific code should
1329 be needed to use it.
1332 When using a watchdog circuitry external to the used
1333 SoC, then define this variable and provide board
1334 specific code for the "hw_watchdog_reset" function.
1336 CONFIG_AT91_HW_WDT_TIMEOUT
1337 specify the timeout in seconds. default 2 seconds.
1340 CONFIG_VERSION_VARIABLE
1341 If this variable is defined, an environment variable
1342 named "ver" is created by U-Boot showing the U-Boot
1343 version as printed by the "version" command.
1344 Any change to this variable will be reverted at the
1349 When CONFIG_CMD_DATE is selected, the type of the RTC
1350 has to be selected, too. Define exactly one of the
1353 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1354 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1355 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1356 CONFIG_RTC_MC146818 - use MC146818 RTC
1357 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1358 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1359 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1360 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1361 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1362 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1363 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1364 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1365 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1368 Note that if the RTC uses I2C, then the I2C interface
1369 must also be configured. See I2C Support, below.
1372 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1374 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1375 chip-ngpio pairs that tell the PCA953X driver the number of
1376 pins supported by a particular chip.
1378 Note that if the GPIO device uses I2C, then the I2C interface
1379 must also be configured. See I2C Support, below.
1382 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1383 accesses and can checksum them or write a list of them out
1384 to memory. See the 'iotrace' command for details. This is
1385 useful for testing device drivers since it can confirm that
1386 the driver behaves the same way before and after a code
1387 change. Currently this is supported on sandbox and arm. To
1388 add support for your architecture, add '#include <iotrace.h>'
1389 to the bottom of arch/<arch>/include/asm/io.h and test.
1391 Example output from the 'iotrace stats' command is below.
1392 Note that if the trace buffer is exhausted, the checksum will
1393 still continue to operate.
1396 Start: 10000000 (buffer start address)
1397 Size: 00010000 (buffer size)
1398 Offset: 00000120 (current buffer offset)
1399 Output: 10000120 (start + offset)
1400 Count: 00000018 (number of trace records)
1401 CRC32: 9526fb66 (CRC32 of all trace records)
1403 - Timestamp Support:
1405 When CONFIG_TIMESTAMP is selected, the timestamp
1406 (date and time) of an image is printed by image
1407 commands like bootm or iminfo. This option is
1408 automatically enabled when you select CONFIG_CMD_DATE .
1410 - Partition Labels (disklabels) Supported:
1411 Zero or more of the following:
1412 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1413 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1414 Intel architecture, USB sticks, etc.
1415 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1416 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1417 bootloader. Note 2TB partition limit; see
1419 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1421 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1422 CONFIG_CMD_SCSI) you must configure support for at
1423 least one non-MTD partition type as well.
1426 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1427 board configurations files but used nowhere!
1429 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1430 be performed by calling the function
1431 ide_set_reset(int reset)
1432 which has to be defined in a board specific file
1437 Set this to enable ATAPI support.
1442 Set this to enable support for disks larger than 137GB
1443 Also look at CONFIG_SYS_64BIT_LBA.
1444 Whithout these , LBA48 support uses 32bit variables and will 'only'
1445 support disks up to 2.1TB.
1447 CONFIG_SYS_64BIT_LBA:
1448 When enabled, makes the IDE subsystem use 64bit sector addresses.
1452 At the moment only there is only support for the
1453 SYM53C8XX SCSI controller; define
1454 CONFIG_SCSI_SYM53C8XX to enable it.
1456 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1457 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1458 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1459 maximum numbers of LUNs, SCSI ID's and target
1461 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1463 The environment variable 'scsidevs' is set to the number of
1464 SCSI devices found during the last scan.
1466 - NETWORK Support (PCI):
1468 Support for Intel 8254x/8257x gigabit chips.
1471 Utility code for direct access to the SPI bus on Intel 8257x.
1472 This does not do anything useful unless you set at least one
1473 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1475 CONFIG_E1000_SPI_GENERIC
1476 Allow generic access to the SPI bus on the Intel 8257x, for
1477 example with the "sspi" command.
1480 Management command for E1000 devices. When used on devices
1481 with SPI support you can reprogram the EEPROM from U-Boot.
1483 CONFIG_E1000_FALLBACK_MAC
1484 default MAC for empty EEPROM after production.
1487 Support for Intel 82557/82559/82559ER chips.
1488 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1489 write routine for first time initialisation.
1492 Support for Digital 2114x chips.
1493 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1494 modem chip initialisation (KS8761/QS6611).
1497 Support for National dp83815 chips.
1500 Support for National dp8382[01] gigabit chips.
1502 - NETWORK Support (other):
1504 CONFIG_DRIVER_AT91EMAC
1505 Support for AT91RM9200 EMAC.
1508 Define this to use reduced MII inteface
1510 CONFIG_DRIVER_AT91EMAC_QUIET
1511 If this defined, the driver is quiet.
1512 The driver doen't show link status messages.
1514 CONFIG_CALXEDA_XGMAC
1515 Support for the Calxeda XGMAC device
1518 Support for SMSC's LAN91C96 chips.
1520 CONFIG_LAN91C96_BASE
1521 Define this to hold the physical address
1522 of the LAN91C96's I/O space
1524 CONFIG_LAN91C96_USE_32_BIT
1525 Define this to enable 32 bit addressing
1528 Support for SMSC's LAN91C111 chip
1530 CONFIG_SMC91111_BASE
1531 Define this to hold the physical address
1532 of the device (I/O space)
1534 CONFIG_SMC_USE_32_BIT
1535 Define this if data bus is 32 bits
1537 CONFIG_SMC_USE_IOFUNCS
1538 Define this to use i/o functions instead of macros
1539 (some hardware wont work with macros)
1541 CONFIG_DRIVER_TI_EMAC
1542 Support for davinci emac
1544 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1545 Define this if you have more then 3 PHYs.
1548 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1550 CONFIG_FTGMAC100_EGIGA
1551 Define this to use GE link update with gigabit PHY.
1552 Define this if FTGMAC100 is connected to gigabit PHY.
1553 If your system has 10/100 PHY only, it might not occur
1554 wrong behavior. Because PHY usually return timeout or
1555 useless data when polling gigabit status and gigabit
1556 control registers. This behavior won't affect the
1557 correctnessof 10/100 link speed update.
1560 Support for SMSC's LAN911x and LAN921x chips
1563 Define this to hold the physical address
1564 of the device (I/O space)
1566 CONFIG_SMC911X_32_BIT
1567 Define this if data bus is 32 bits
1569 CONFIG_SMC911X_16_BIT
1570 Define this if data bus is 16 bits. If your processor
1571 automatically converts one 32 bit word to two 16 bit
1572 words you may also try CONFIG_SMC911X_32_BIT.
1575 Support for Renesas on-chip Ethernet controller
1577 CONFIG_SH_ETHER_USE_PORT
1578 Define the number of ports to be used
1580 CONFIG_SH_ETHER_PHY_ADDR
1581 Define the ETH PHY's address
1583 CONFIG_SH_ETHER_CACHE_WRITEBACK
1584 If this option is set, the driver enables cache flush.
1588 Support for PWM modul on the imx6.
1592 Support TPM devices.
1595 Support for i2c bus TPM devices. Only one device
1596 per system is supported at this time.
1598 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1599 Define the the i2c bus number for the TPM device
1601 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1602 Define the TPM's address on the i2c bus
1604 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1605 Define the burst count bytes upper limit
1607 CONFIG_TPM_ATMEL_TWI
1608 Support for Atmel TWI TPM device. Requires I2C support.
1611 Support for generic parallel port TPM devices. Only one device
1612 per system is supported at this time.
1614 CONFIG_TPM_TIS_BASE_ADDRESS
1615 Base address where the generic TPM device is mapped
1616 to. Contemporary x86 systems usually map it at
1620 Add tpm monitor functions.
1621 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1622 provides monitor access to authorized functions.
1625 Define this to enable the TPM support library which provides
1626 functional interfaces to some TPM commands.
1627 Requires support for a TPM device.
1629 CONFIG_TPM_AUTH_SESSIONS
1630 Define this to enable authorized functions in the TPM library.
1631 Requires CONFIG_TPM and CONFIG_SHA1.
1634 At the moment only the UHCI host controller is
1635 supported (PIP405, MIP405, MPC5200); define
1636 CONFIG_USB_UHCI to enable it.
1637 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1638 and define CONFIG_USB_STORAGE to enable the USB
1641 Supported are USB Keyboards and USB Floppy drives
1643 MPC5200 USB requires additional defines:
1645 for 528 MHz Clock: 0x0001bbbb
1649 for differential drivers: 0x00001000
1650 for single ended drivers: 0x00005000
1651 for differential drivers on PSC3: 0x00000100
1652 for single ended drivers on PSC3: 0x00004100
1653 CONFIG_SYS_USB_EVENT_POLL
1654 May be defined to allow interrupt polling
1655 instead of using asynchronous interrupts
1657 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1658 txfilltuning field in the EHCI controller on reset.
1660 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1661 HW module registers.
1664 Define the below if you wish to use the USB console.
1665 Once firmware is rebuilt from a serial console issue the
1666 command "setenv stdin usbtty; setenv stdout usbtty" and
1667 attach your USB cable. The Unix command "dmesg" should print
1668 it has found a new device. The environment variable usbtty
1669 can be set to gserial or cdc_acm to enable your device to
1670 appear to a USB host as a Linux gserial device or a
1671 Common Device Class Abstract Control Model serial device.
1672 If you select usbtty = gserial you should be able to enumerate
1674 # modprobe usbserial vendor=0xVendorID product=0xProductID
1675 else if using cdc_acm, simply setting the environment
1676 variable usbtty to be cdc_acm should suffice. The following
1677 might be defined in YourBoardName.h
1680 Define this to build a UDC device
1683 Define this to have a tty type of device available to
1684 talk to the UDC device
1687 Define this to enable the high speed support for usb
1688 device and usbtty. If this feature is enabled, a routine
1689 int is_usbd_high_speed(void)
1690 also needs to be defined by the driver to dynamically poll
1691 whether the enumeration has succeded at high speed or full
1694 CONFIG_SYS_CONSOLE_IS_IN_ENV
1695 Define this if you want stdin, stdout &/or stderr to
1699 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1700 Derive USB clock from external clock "blah"
1701 - CONFIG_SYS_USB_EXTC_CLK 0x02
1703 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1704 Derive USB clock from brgclk
1705 - CONFIG_SYS_USB_BRG_CLK 0x04
1707 If you have a USB-IF assigned VendorID then you may wish to
1708 define your own vendor specific values either in BoardName.h
1709 or directly in usbd_vendor_info.h. If you don't define
1710 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1711 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1712 should pretend to be a Linux device to it's target host.
1714 CONFIG_USBD_MANUFACTURER
1715 Define this string as the name of your company for
1716 - CONFIG_USBD_MANUFACTURER "my company"
1718 CONFIG_USBD_PRODUCT_NAME
1719 Define this string as the name of your product
1720 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1722 CONFIG_USBD_VENDORID
1723 Define this as your assigned Vendor ID from the USB
1724 Implementors Forum. This *must* be a genuine Vendor ID
1725 to avoid polluting the USB namespace.
1726 - CONFIG_USBD_VENDORID 0xFFFF
1728 CONFIG_USBD_PRODUCTID
1729 Define this as the unique Product ID
1731 - CONFIG_USBD_PRODUCTID 0xFFFF
1733 - ULPI Layer Support:
1734 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1735 the generic ULPI layer. The generic layer accesses the ULPI PHY
1736 via the platform viewport, so you need both the genric layer and
1737 the viewport enabled. Currently only Chipidea/ARC based
1738 viewport is supported.
1739 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1740 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1741 If your ULPI phy needs a different reference clock than the
1742 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1743 the appropriate value in Hz.
1746 The MMC controller on the Intel PXA is supported. To
1747 enable this define CONFIG_MMC. The MMC can be
1748 accessed from the boot prompt by mapping the device
1749 to physical memory similar to flash. Command line is
1750 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1751 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1754 Support for Renesas on-chip MMCIF controller
1756 CONFIG_SH_MMCIF_ADDR
1757 Define the base address of MMCIF registers
1760 Define the clock frequency for MMCIF
1763 Enable the generic MMC driver
1765 CONFIG_SUPPORT_EMMC_BOOT
1766 Enable some additional features of the eMMC boot partitions.
1768 CONFIG_SUPPORT_EMMC_RPMB
1769 Enable the commands for reading, writing and programming the
1770 key for the Replay Protection Memory Block partition in eMMC.
1772 - USB Device Firmware Update (DFU) class support:
1774 This enables the USB portion of the DFU USB class
1777 This enables the command "dfu" which is used to have
1778 U-Boot create a DFU class device via USB. This command
1779 requires that the "dfu_alt_info" environment variable be
1780 set and define the alt settings to expose to the host.
1783 This enables support for exposing (e)MMC devices via DFU.
1786 This enables support for exposing NAND devices via DFU.
1789 This enables support for exposing RAM via DFU.
1790 Note: DFU spec refer to non-volatile memory usage, but
1791 allow usages beyond the scope of spec - here RAM usage,
1792 one that would help mostly the developer.
1794 CONFIG_SYS_DFU_DATA_BUF_SIZE
1795 Dfu transfer uses a buffer before writing data to the
1796 raw storage device. Make the size (in bytes) of this buffer
1797 configurable. The size of this buffer is also configurable
1798 through the "dfu_bufsiz" environment variable.
1800 CONFIG_SYS_DFU_MAX_FILE_SIZE
1801 When updating files rather than the raw storage device,
1802 we use a static buffer to copy the file into and then write
1803 the buffer once we've been given the whole file. Define
1804 this to the maximum filesize (in bytes) for the buffer.
1805 Default is 4 MiB if undefined.
1807 DFU_DEFAULT_POLL_TIMEOUT
1808 Poll timeout [ms], is the timeout a device can send to the
1809 host. The host must wait for this timeout before sending
1810 a subsequent DFU_GET_STATUS request to the device.
1812 DFU_MANIFEST_POLL_TIMEOUT
1813 Poll timeout [ms], which the device sends to the host when
1814 entering dfuMANIFEST state. Host waits this timeout, before
1815 sending again an USB request to the device.
1817 - USB Device Android Fastboot support:
1819 This enables the command "fastboot" which enables the Android
1820 fastboot mode for the platform's USB device. Fastboot is a USB
1821 protocol for downloading images, flashing and device control
1822 used on Android devices.
1823 See doc/README.android-fastboot for more information.
1825 CONFIG_ANDROID_BOOT_IMAGE
1826 This enables support for booting images which use the Android
1827 image format header.
1829 CONFIG_USB_FASTBOOT_BUF_ADDR
1830 The fastboot protocol requires a large memory buffer for
1831 downloads. Define this to the starting RAM address to use for
1834 CONFIG_USB_FASTBOOT_BUF_SIZE
1835 The fastboot protocol requires a large memory buffer for
1836 downloads. This buffer should be as large as possible for a
1837 platform. Define this to the size available RAM for fastboot.
1839 CONFIG_FASTBOOT_FLASH
1840 The fastboot protocol includes a "flash" command for writing
1841 the downloaded image to a non-volatile storage device. Define
1842 this to enable the "fastboot flash" command.
1844 CONFIG_FASTBOOT_FLASH_MMC_DEV
1845 The fastboot "flash" command requires additional information
1846 regarding the non-volatile storage device. Define this to
1847 the eMMC device that fastboot should use to store the image.
1849 CONFIG_FASTBOOT_GPT_NAME
1850 The fastboot "flash" command supports writing the downloaded
1851 image to the Protective MBR and the Primary GUID Partition
1852 Table. (Additionally, this downloaded image is post-processed
1853 to generate and write the Backup GUID Partition Table.)
1854 This occurs when the specified "partition name" on the
1855 "fastboot flash" command line matches this value.
1856 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1858 - Journaling Flash filesystem support:
1859 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1860 CONFIG_JFFS2_NAND_DEV
1861 Define these for a default partition on a NAND device
1863 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1864 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1865 Define these for a default partition on a NOR device
1867 CONFIG_SYS_JFFS_CUSTOM_PART
1868 Define this to create an own partition. You have to provide a
1869 function struct part_info* jffs2_part_info(int part_num)
1871 If you define only one JFFS2 partition you may also want to
1872 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1873 to disable the command chpart. This is the default when you
1874 have not defined a custom partition
1876 - FAT(File Allocation Table) filesystem write function support:
1879 Define this to enable support for saving memory data as a
1880 file in FAT formatted partition.
1882 This will also enable the command "fatwrite" enabling the
1883 user to write files to FAT.
1885 CBFS (Coreboot Filesystem) support
1888 Define this to enable support for reading from a Coreboot
1889 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1892 - FAT(File Allocation Table) filesystem cluster size:
1893 CONFIG_FS_FAT_MAX_CLUSTSIZE
1895 Define the max cluster size for fat operations else
1896 a default value of 65536 will be defined.
1901 Define this to enable standard (PC-Style) keyboard
1905 Standard PC keyboard driver with US (is default) and
1906 GERMAN key layout (switch via environment 'keymap=de') support.
1907 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1908 for cfb_console. Supports cursor blinking.
1911 Enables a Chrome OS keyboard using the CROS_EC interface.
1912 This uses CROS_EC to communicate with a second microcontroller
1913 which provides key scans on request.
1918 Define this to enable video support (for output to
1921 CONFIG_VIDEO_CT69000
1923 Enable Chips & Technologies 69000 Video chip
1925 CONFIG_VIDEO_SMI_LYNXEM
1926 Enable Silicon Motion SMI 712/710/810 Video chip. The
1927 video output is selected via environment 'videoout'
1928 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1931 For the CT69000 and SMI_LYNXEM drivers, videomode is
1932 selected via environment 'videomode'. Two different ways
1934 - "videomode=num" 'num' is a standard LiLo mode numbers.
1935 Following standard modes are supported (* is default):
1937 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1938 -------------+---------------------------------------------
1939 8 bits | 0x301* 0x303 0x305 0x161 0x307
1940 15 bits | 0x310 0x313 0x316 0x162 0x319
1941 16 bits | 0x311 0x314 0x317 0x163 0x31A
1942 24 bits | 0x312 0x315 0x318 ? 0x31B
1943 -------------+---------------------------------------------
1944 (i.e. setenv videomode 317; saveenv; reset;)
1946 - "videomode=bootargs" all the video parameters are parsed
1947 from the bootargs. (See drivers/video/videomodes.c)
1950 CONFIG_VIDEO_SED13806
1951 Enable Epson SED13806 driver. This driver supports 8bpp
1952 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1953 or CONFIG_VIDEO_SED13806_16BPP
1956 Enable the Freescale DIU video driver. Reference boards for
1957 SOCs that have a DIU should define this macro to enable DIU
1958 support, and should also define these other macros:
1964 CONFIG_VIDEO_SW_CURSOR
1965 CONFIG_VGA_AS_SINGLE_DEVICE
1967 CONFIG_VIDEO_BMP_LOGO
1969 The DIU driver will look for the 'video-mode' environment
1970 variable, and if defined, enable the DIU as a console during
1971 boot. See the documentation file README.video for a
1972 description of this variable.
1976 Enable the VGA video / BIOS for x86. The alternative if you
1977 are using coreboot is to use the coreboot frame buffer
1984 Define this to enable a custom keyboard support.
1985 This simply calls drv_keyboard_init() which must be
1986 defined in your board-specific files.
1987 The only board using this so far is RBC823.
1989 - LCD Support: CONFIG_LCD
1991 Define this to enable LCD support (for output to LCD
1992 display); also select one of the supported displays
1993 by defining one of these:
1997 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1999 CONFIG_NEC_NL6448AC33:
2001 NEC NL6448AC33-18. Active, color, single scan.
2003 CONFIG_NEC_NL6448BC20
2005 NEC NL6448BC20-08. 6.5", 640x480.
2006 Active, color, single scan.
2008 CONFIG_NEC_NL6448BC33_54
2010 NEC NL6448BC33-54. 10.4", 640x480.
2011 Active, color, single scan.
2015 Sharp 320x240. Active, color, single scan.
2016 It isn't 16x9, and I am not sure what it is.
2018 CONFIG_SHARP_LQ64D341
2020 Sharp LQ64D341 display, 640x480.
2021 Active, color, single scan.
2025 HLD1045 display, 640x480.
2026 Active, color, single scan.
2030 Optrex CBL50840-2 NF-FW 99 22 M5
2032 Hitachi LMG6912RPFC-00T
2036 320x240. Black & white.
2038 Normally display is black on white background; define
2039 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2041 CONFIG_LCD_ALIGNMENT
2043 Normally the LCD is page-aligned (typically 4KB). If this is
2044 defined then the LCD will be aligned to this value instead.
2045 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2046 here, since it is cheaper to change data cache settings on
2047 a per-section basis.
2049 CONFIG_CONSOLE_SCROLL_LINES
2051 When the console need to be scrolled, this is the number of
2052 lines to scroll by. It defaults to 1. Increasing this makes
2053 the console jump but can help speed up operation when scrolling
2058 Support drawing of RLE8-compressed bitmaps on the LCD.
2062 Enables an 'i2c edid' command which can read EDID
2063 information over I2C from an attached LCD display.
2065 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2067 If this option is set, the environment is checked for
2068 a variable "splashimage". If found, the usual display
2069 of logo, copyright and system information on the LCD
2070 is suppressed and the BMP image at the address
2071 specified in "splashimage" is loaded instead. The
2072 console is redirected to the "nulldev", too. This
2073 allows for a "silent" boot where a splash screen is
2074 loaded very quickly after power-on.
2076 CONFIG_SPLASHIMAGE_GUARD
2078 If this option is set, then U-Boot will prevent the environment
2079 variable "splashimage" from being set to a problematic address
2080 (see README.displaying-bmps).
2081 This option is useful for targets where, due to alignment
2082 restrictions, an improperly aligned BMP image will cause a data
2083 abort. If you think you will not have problems with unaligned
2084 accesses (for example because your toolchain prevents them)
2085 there is no need to set this option.
2087 CONFIG_SPLASH_SCREEN_ALIGN
2089 If this option is set the splash image can be freely positioned
2090 on the screen. Environment variable "splashpos" specifies the
2091 position as "x,y". If a positive number is given it is used as
2092 number of pixel from left/top. If a negative number is given it
2093 is used as number of pixel from right/bottom. You can also
2094 specify 'm' for centering the image.
2097 setenv splashpos m,m
2098 => image at center of screen
2100 setenv splashpos 30,20
2101 => image at x = 30 and y = 20
2103 setenv splashpos -10,m
2104 => vertically centered image
2105 at x = dspWidth - bmpWidth - 9
2107 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2109 If this option is set, additionally to standard BMP
2110 images, gzipped BMP images can be displayed via the
2111 splashscreen support or the bmp command.
2113 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2115 If this option is set, 8-bit RLE compressed BMP images
2116 can be displayed via the splashscreen support or the
2119 - Do compressing for memory range:
2122 If this option is set, it would use zlib deflate method
2123 to compress the specified memory at its best effort.
2125 - Compression support:
2128 Enabled by default to support gzip compressed images.
2132 If this option is set, support for bzip2 compressed
2133 images is included. If not, only uncompressed and gzip
2134 compressed images are supported.
2136 NOTE: the bzip2 algorithm requires a lot of RAM, so
2137 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2142 If this option is set, support for lzma compressed
2145 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2146 requires an amount of dynamic memory that is given by the
2149 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2151 Where lc and lp stand for, respectively, Literal context bits
2152 and Literal pos bits.
2154 This value is upper-bounded by 14MB in the worst case. Anyway,
2155 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2156 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2157 a very small buffer.
2159 Use the lzmainfo tool to determinate the lc and lp values and
2160 then calculate the amount of needed dynamic memory (ensuring
2161 the appropriate CONFIG_SYS_MALLOC_LEN value).
2165 If this option is set, support for LZO compressed images
2171 The address of PHY on MII bus.
2173 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2175 The clock frequency of the MII bus
2179 If this option is set, support for speed/duplex
2180 detection of gigabit PHY is included.
2182 CONFIG_PHY_RESET_DELAY
2184 Some PHY like Intel LXT971A need extra delay after
2185 reset before any MII register access is possible.
2186 For such PHY, set this option to the usec delay
2187 required. (minimum 300usec for LXT971A)
2189 CONFIG_PHY_CMD_DELAY (ppc4xx)
2191 Some PHY like Intel LXT971A need extra delay after
2192 command issued before MII status register can be read
2202 Define a default value for Ethernet address to use
2203 for the respective Ethernet interface, in case this
2204 is not determined automatically.
2209 Define a default value for the IP address to use for
2210 the default Ethernet interface, in case this is not
2211 determined through e.g. bootp.
2212 (Environment variable "ipaddr")
2214 - Server IP address:
2217 Defines a default value for the IP address of a TFTP
2218 server to contact when using the "tftboot" command.
2219 (Environment variable "serverip")
2221 CONFIG_KEEP_SERVERADDR
2223 Keeps the server's MAC address, in the env 'serveraddr'
2224 for passing to bootargs (like Linux's netconsole option)
2226 - Gateway IP address:
2229 Defines a default value for the IP address of the
2230 default router where packets to other networks are
2232 (Environment variable "gatewayip")
2237 Defines a default value for the subnet mask (or
2238 routing prefix) which is used to determine if an IP
2239 address belongs to the local subnet or needs to be
2240 forwarded through a router.
2241 (Environment variable "netmask")
2243 - Multicast TFTP Mode:
2246 Defines whether you want to support multicast TFTP as per
2247 rfc-2090; for example to work with atftp. Lets lots of targets
2248 tftp down the same boot image concurrently. Note: the Ethernet
2249 driver in use must provide a function: mcast() to join/leave a
2252 - BOOTP Recovery Mode:
2253 CONFIG_BOOTP_RANDOM_DELAY
2255 If you have many targets in a network that try to
2256 boot using BOOTP, you may want to avoid that all
2257 systems send out BOOTP requests at precisely the same
2258 moment (which would happen for instance at recovery
2259 from a power failure, when all systems will try to
2260 boot, thus flooding the BOOTP server. Defining
2261 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2262 inserted before sending out BOOTP requests. The
2263 following delays are inserted then:
2265 1st BOOTP request: delay 0 ... 1 sec
2266 2nd BOOTP request: delay 0 ... 2 sec
2267 3rd BOOTP request: delay 0 ... 4 sec
2269 BOOTP requests: delay 0 ... 8 sec
2271 CONFIG_BOOTP_ID_CACHE_SIZE
2273 BOOTP packets are uniquely identified using a 32-bit ID. The
2274 server will copy the ID from client requests to responses and
2275 U-Boot will use this to determine if it is the destination of
2276 an incoming response. Some servers will check that addresses
2277 aren't in use before handing them out (usually using an ARP
2278 ping) and therefore take up to a few hundred milliseconds to
2279 respond. Network congestion may also influence the time it
2280 takes for a response to make it back to the client. If that
2281 time is too long, U-Boot will retransmit requests. In order
2282 to allow earlier responses to still be accepted after these
2283 retransmissions, U-Boot's BOOTP client keeps a small cache of
2284 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2285 cache. The default is to keep IDs for up to four outstanding
2286 requests. Increasing this will allow U-Boot to accept offers
2287 from a BOOTP client in networks with unusually high latency.
2289 - BOOTP Random transaction ID:
2290 CONFIG_BOOTP_RANDOM_ID
2292 The standard algorithm to generate a DHCP/BOOTP transaction ID
2293 by using the MAC address and the current time stamp may not
2294 quite unlikely produce duplicate transaction IDs from different
2295 clients in the same network. This option creates a transaction
2296 ID using the rand() function. Provided that the RNG has been
2297 seeded well, this should guarantee unique transaction IDs
2300 - DHCP Advanced Options:
2301 You can fine tune the DHCP functionality by defining
2302 CONFIG_BOOTP_* symbols:
2304 CONFIG_BOOTP_SUBNETMASK
2305 CONFIG_BOOTP_GATEWAY
2306 CONFIG_BOOTP_HOSTNAME
2307 CONFIG_BOOTP_NISDOMAIN
2308 CONFIG_BOOTP_BOOTPATH
2309 CONFIG_BOOTP_BOOTFILESIZE
2312 CONFIG_BOOTP_SEND_HOSTNAME
2313 CONFIG_BOOTP_NTPSERVER
2314 CONFIG_BOOTP_TIMEOFFSET
2315 CONFIG_BOOTP_VENDOREX
2316 CONFIG_BOOTP_MAY_FAIL
2318 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2319 environment variable, not the BOOTP server.
2321 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2322 after the configured retry count, the call will fail
2323 instead of starting over. This can be used to fail over
2324 to Link-local IP address configuration if the DHCP server
2327 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2328 serverip from a DHCP server, it is possible that more
2329 than one DNS serverip is offered to the client.
2330 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2331 serverip will be stored in the additional environment
2332 variable "dnsip2". The first DNS serverip is always
2333 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2336 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2337 to do a dynamic update of a DNS server. To do this, they
2338 need the hostname of the DHCP requester.
2339 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2340 of the "hostname" environment variable is passed as
2341 option 12 to the DHCP server.
2343 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2345 A 32bit value in microseconds for a delay between
2346 receiving a "DHCP Offer" and sending the "DHCP Request".
2347 This fixes a problem with certain DHCP servers that don't
2348 respond 100% of the time to a "DHCP request". E.g. On an
2349 AT91RM9200 processor running at 180MHz, this delay needed
2350 to be *at least* 15,000 usec before a Windows Server 2003
2351 DHCP server would reply 100% of the time. I recommend at
2352 least 50,000 usec to be safe. The alternative is to hope
2353 that one of the retries will be successful but note that
2354 the DHCP timeout and retry process takes a longer than
2357 - Link-local IP address negotiation:
2358 Negotiate with other link-local clients on the local network
2359 for an address that doesn't require explicit configuration.
2360 This is especially useful if a DHCP server cannot be guaranteed
2361 to exist in all environments that the device must operate.
2363 See doc/README.link-local for more information.
2366 CONFIG_CDP_DEVICE_ID
2368 The device id used in CDP trigger frames.
2370 CONFIG_CDP_DEVICE_ID_PREFIX
2372 A two character string which is prefixed to the MAC address
2377 A printf format string which contains the ascii name of
2378 the port. Normally is set to "eth%d" which sets
2379 eth0 for the first Ethernet, eth1 for the second etc.
2381 CONFIG_CDP_CAPABILITIES
2383 A 32bit integer which indicates the device capabilities;
2384 0x00000010 for a normal host which does not forwards.
2388 An ascii string containing the version of the software.
2392 An ascii string containing the name of the platform.
2396 A 32bit integer sent on the trigger.
2398 CONFIG_CDP_POWER_CONSUMPTION
2400 A 16bit integer containing the power consumption of the
2401 device in .1 of milliwatts.
2403 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2405 A byte containing the id of the VLAN.
2407 - Status LED: CONFIG_STATUS_LED
2409 Several configurations allow to display the current
2410 status using a LED. For instance, the LED will blink
2411 fast while running U-Boot code, stop blinking as
2412 soon as a reply to a BOOTP request was received, and
2413 start blinking slow once the Linux kernel is running
2414 (supported by a status LED driver in the Linux
2415 kernel). Defining CONFIG_STATUS_LED enables this
2421 The status LED can be connected to a GPIO pin.
2422 In such cases, the gpio_led driver can be used as a
2423 status LED backend implementation. Define CONFIG_GPIO_LED
2424 to include the gpio_led driver in the U-Boot binary.
2426 CONFIG_GPIO_LED_INVERTED_TABLE
2427 Some GPIO connected LEDs may have inverted polarity in which
2428 case the GPIO high value corresponds to LED off state and
2429 GPIO low value corresponds to LED on state.
2430 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2431 with a list of GPIO LEDs that have inverted polarity.
2433 - CAN Support: CONFIG_CAN_DRIVER
2435 Defining CONFIG_CAN_DRIVER enables CAN driver support
2436 on those systems that support this (optional)
2437 feature, like the TQM8xxL modules.
2439 - I2C Support: CONFIG_SYS_I2C
2441 This enable the NEW i2c subsystem, and will allow you to use
2442 i2c commands at the u-boot command line (as long as you set
2443 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2444 based realtime clock chips or other i2c devices. See
2445 common/cmd_i2c.c for a description of the command line
2448 ported i2c driver to the new framework:
2449 - drivers/i2c/soft_i2c.c:
2450 - activate first bus with CONFIG_SYS_I2C_SOFT define
2451 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2452 for defining speed and slave address
2453 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2454 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2455 for defining speed and slave address
2456 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2457 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2458 for defining speed and slave address
2459 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2460 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2461 for defining speed and slave address
2463 - drivers/i2c/fsl_i2c.c:
2464 - activate i2c driver with CONFIG_SYS_I2C_FSL
2465 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2466 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2467 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2469 - If your board supports a second fsl i2c bus, define
2470 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2471 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2472 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2475 - drivers/i2c/tegra_i2c.c:
2476 - activate this driver with CONFIG_SYS_I2C_TEGRA
2477 - This driver adds 4 i2c buses with a fix speed from
2478 100000 and the slave addr 0!
2480 - drivers/i2c/ppc4xx_i2c.c
2481 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2482 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2483 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2485 - drivers/i2c/i2c_mxc.c
2486 - activate this driver with CONFIG_SYS_I2C_MXC
2487 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2488 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2489 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2490 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2491 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2492 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2493 If those defines are not set, default value is 100000
2494 for speed, and 0 for slave.
2496 - drivers/i2c/rcar_i2c.c:
2497 - activate this driver with CONFIG_SYS_I2C_RCAR
2498 - This driver adds 4 i2c buses
2500 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2501 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2502 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2503 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2504 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2505 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2506 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2507 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2508 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2510 - drivers/i2c/sh_i2c.c:
2511 - activate this driver with CONFIG_SYS_I2C_SH
2512 - This driver adds from 2 to 5 i2c buses
2514 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2515 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2516 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2517 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2518 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2519 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2520 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2521 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2522 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2523 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2524 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2525 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2526 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2528 - drivers/i2c/omap24xx_i2c.c
2529 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2530 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2531 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2532 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2533 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2534 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2535 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2536 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2537 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2538 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2539 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2541 - drivers/i2c/zynq_i2c.c
2542 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2543 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2544 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2546 - drivers/i2c/s3c24x0_i2c.c:
2547 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2548 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2549 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2550 with a fix speed from 100000 and the slave addr 0!
2552 - drivers/i2c/ihs_i2c.c
2553 - activate this driver with CONFIG_SYS_I2C_IHS
2554 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2555 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2556 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2557 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2558 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2559 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2560 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2561 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2562 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2563 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2564 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2565 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2569 CONFIG_SYS_NUM_I2C_BUSES
2570 Hold the number of i2c buses you want to use. If you
2571 don't use/have i2c muxes on your i2c bus, this
2572 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2575 CONFIG_SYS_I2C_DIRECT_BUS
2576 define this, if you don't use i2c muxes on your hardware.
2577 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2580 CONFIG_SYS_I2C_MAX_HOPS
2581 define how many muxes are maximal consecutively connected
2582 on one i2c bus. If you not use i2c muxes, omit this
2585 CONFIG_SYS_I2C_BUSES
2586 hold a list of buses you want to use, only used if
2587 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2588 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2589 CONFIG_SYS_NUM_I2C_BUSES = 9:
2591 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2592 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2593 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2594 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2595 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2596 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2597 {1, {I2C_NULL_HOP}}, \
2598 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2599 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2603 bus 0 on adapter 0 without a mux
2604 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2605 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2606 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2607 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2608 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2609 bus 6 on adapter 1 without a mux
2610 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2611 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2613 If you do not have i2c muxes on your board, omit this define.
2615 - Legacy I2C Support: CONFIG_HARD_I2C
2617 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2618 provides the following compelling advantages:
2620 - more than one i2c adapter is usable
2621 - approved multibus support
2622 - better i2c mux support
2624 ** Please consider updating your I2C driver now. **
2626 These enable legacy I2C serial bus commands. Defining
2627 CONFIG_HARD_I2C will include the appropriate I2C driver
2628 for the selected CPU.
2630 This will allow you to use i2c commands at the u-boot
2631 command line (as long as you set CONFIG_CMD_I2C in
2632 CONFIG_COMMANDS) and communicate with i2c based realtime
2633 clock chips. See common/cmd_i2c.c for a description of the
2634 command line interface.
2636 CONFIG_HARD_I2C selects a hardware I2C controller.
2638 There are several other quantities that must also be
2639 defined when you define CONFIG_HARD_I2C.
2641 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2642 to be the frequency (in Hz) at which you wish your i2c bus
2643 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2644 the CPU's i2c node address).
2646 Now, the u-boot i2c code for the mpc8xx
2647 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2648 and so its address should therefore be cleared to 0 (See,
2649 eg, MPC823e User's Manual p.16-473). So, set
2650 CONFIG_SYS_I2C_SLAVE to 0.
2652 CONFIG_SYS_I2C_INIT_MPC5XXX
2654 When a board is reset during an i2c bus transfer
2655 chips might think that the current transfer is still
2656 in progress. Reset the slave devices by sending start
2657 commands until the slave device responds.
2659 That's all that's required for CONFIG_HARD_I2C.
2661 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2662 then the following macros need to be defined (examples are
2663 from include/configs/lwmon.h):
2667 (Optional). Any commands necessary to enable the I2C
2668 controller or configure ports.
2670 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2674 (Only for MPC8260 CPU). The I/O port to use (the code
2675 assumes both bits are on the same port). Valid values
2676 are 0..3 for ports A..D.
2680 The code necessary to make the I2C data line active
2681 (driven). If the data line is open collector, this
2684 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2688 The code necessary to make the I2C data line tri-stated
2689 (inactive). If the data line is open collector, this
2692 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2696 Code that returns true if the I2C data line is high,
2699 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2703 If <bit> is true, sets the I2C data line high. If it
2704 is false, it clears it (low).
2706 eg: #define I2C_SDA(bit) \
2707 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2708 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2712 If <bit> is true, sets the I2C clock line high. If it
2713 is false, it clears it (low).
2715 eg: #define I2C_SCL(bit) \
2716 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2717 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2721 This delay is invoked four times per clock cycle so this
2722 controls the rate of data transfer. The data rate thus
2723 is 1 / (I2C_DELAY * 4). Often defined to be something
2726 #define I2C_DELAY udelay(2)
2728 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2730 If your arch supports the generic GPIO framework (asm/gpio.h),
2731 then you may alternatively define the two GPIOs that are to be
2732 used as SCL / SDA. Any of the previous I2C_xxx macros will
2733 have GPIO-based defaults assigned to them as appropriate.
2735 You should define these to the GPIO value as given directly to
2736 the generic GPIO functions.
2738 CONFIG_SYS_I2C_INIT_BOARD
2740 When a board is reset during an i2c bus transfer
2741 chips might think that the current transfer is still
2742 in progress. On some boards it is possible to access
2743 the i2c SCLK line directly, either by using the
2744 processor pin as a GPIO or by having a second pin
2745 connected to the bus. If this option is defined a
2746 custom i2c_init_board() routine in boards/xxx/board.c
2747 is run early in the boot sequence.
2749 CONFIG_SYS_I2C_BOARD_LATE_INIT
2751 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2752 defined a custom i2c_board_late_init() routine in
2753 boards/xxx/board.c is run AFTER the operations in i2c_init()
2754 is completed. This callpoint can be used to unreset i2c bus
2755 using CPU i2c controller register accesses for CPUs whose i2c
2756 controller provide such a method. It is called at the end of
2757 i2c_init() to allow i2c_init operations to setup the i2c bus
2758 controller on the CPU (e.g. setting bus speed & slave address).
2760 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2762 This option enables configuration of bi_iic_fast[] flags
2763 in u-boot bd_info structure based on u-boot environment
2764 variable "i2cfast". (see also i2cfast)
2766 CONFIG_I2C_MULTI_BUS
2768 This option allows the use of multiple I2C buses, each of which
2769 must have a controller. At any point in time, only one bus is
2770 active. To switch to a different bus, use the 'i2c dev' command.
2771 Note that bus numbering is zero-based.
2773 CONFIG_SYS_I2C_NOPROBES
2775 This option specifies a list of I2C devices that will be skipped
2776 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2777 is set, specify a list of bus-device pairs. Otherwise, specify
2778 a 1D array of device addresses
2781 #undef CONFIG_I2C_MULTI_BUS
2782 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2784 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2786 #define CONFIG_I2C_MULTI_BUS
2787 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2789 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2791 CONFIG_SYS_SPD_BUS_NUM
2793 If defined, then this indicates the I2C bus number for DDR SPD.
2794 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2796 CONFIG_SYS_RTC_BUS_NUM
2798 If defined, then this indicates the I2C bus number for the RTC.
2799 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2801 CONFIG_SYS_DTT_BUS_NUM
2803 If defined, then this indicates the I2C bus number for the DTT.
2804 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2806 CONFIG_SYS_I2C_DTT_ADDR:
2808 If defined, specifies the I2C address of the DTT device.
2809 If not defined, then U-Boot uses predefined value for
2810 specified DTT device.
2812 CONFIG_SOFT_I2C_READ_REPEATED_START
2814 defining this will force the i2c_read() function in
2815 the soft_i2c driver to perform an I2C repeated start
2816 between writing the address pointer and reading the
2817 data. If this define is omitted the default behaviour
2818 of doing a stop-start sequence will be used. Most I2C
2819 devices can use either method, but some require one or
2822 - SPI Support: CONFIG_SPI
2824 Enables SPI driver (so far only tested with
2825 SPI EEPROM, also an instance works with Crystal A/D and
2826 D/As on the SACSng board)
2830 Enables the driver for SPI controller on SuperH. Currently
2831 only SH7757 is supported.
2835 Enables extended (16-bit) SPI EEPROM addressing.
2836 (symmetrical to CONFIG_I2C_X)
2840 Enables a software (bit-bang) SPI driver rather than
2841 using hardware support. This is a general purpose
2842 driver that only requires three general I/O port pins
2843 (two outputs, one input) to function. If this is
2844 defined, the board configuration must define several
2845 SPI configuration items (port pins to use, etc). For
2846 an example, see include/configs/sacsng.h.
2850 Enables a hardware SPI driver for general-purpose reads
2851 and writes. As with CONFIG_SOFT_SPI, the board configuration
2852 must define a list of chip-select function pointers.
2853 Currently supported on some MPC8xxx processors. For an
2854 example, see include/configs/mpc8349emds.h.
2858 Enables the driver for the SPI controllers on i.MX and MXC
2859 SoCs. Currently i.MX31/35/51 are supported.
2861 CONFIG_SYS_SPI_MXC_WAIT
2862 Timeout for waiting until spi transfer completed.
2863 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2865 - FPGA Support: CONFIG_FPGA
2867 Enables FPGA subsystem.
2869 CONFIG_FPGA_<vendor>
2871 Enables support for specific chip vendors.
2874 CONFIG_FPGA_<family>
2876 Enables support for FPGA family.
2877 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2881 Specify the number of FPGA devices to support.
2883 CONFIG_CMD_FPGA_LOADMK
2885 Enable support for fpga loadmk command
2887 CONFIG_CMD_FPGA_LOADP
2889 Enable support for fpga loadp command - load partial bitstream
2891 CONFIG_CMD_FPGA_LOADBP
2893 Enable support for fpga loadbp command - load partial bitstream
2896 CONFIG_SYS_FPGA_PROG_FEEDBACK
2898 Enable printing of hash marks during FPGA configuration.
2900 CONFIG_SYS_FPGA_CHECK_BUSY
2902 Enable checks on FPGA configuration interface busy
2903 status by the configuration function. This option
2904 will require a board or device specific function to
2909 If defined, a function that provides delays in the FPGA
2910 configuration driver.
2912 CONFIG_SYS_FPGA_CHECK_CTRLC
2913 Allow Control-C to interrupt FPGA configuration
2915 CONFIG_SYS_FPGA_CHECK_ERROR
2917 Check for configuration errors during FPGA bitfile
2918 loading. For example, abort during Virtex II
2919 configuration if the INIT_B line goes low (which
2920 indicated a CRC error).
2922 CONFIG_SYS_FPGA_WAIT_INIT
2924 Maximum time to wait for the INIT_B line to de-assert
2925 after PROB_B has been de-asserted during a Virtex II
2926 FPGA configuration sequence. The default time is 500
2929 CONFIG_SYS_FPGA_WAIT_BUSY
2931 Maximum time to wait for BUSY to de-assert during
2932 Virtex II FPGA configuration. The default is 5 ms.
2934 CONFIG_SYS_FPGA_WAIT_CONFIG
2936 Time to wait after FPGA configuration. The default is
2939 - Configuration Management:
2942 Some SoCs need special image types (e.g. U-Boot binary
2943 with a special header) as build targets. By defining
2944 CONFIG_BUILD_TARGET in the SoC / board header, this
2945 special image will be automatically built upon calling
2950 If defined, this string will be added to the U-Boot
2951 version information (U_BOOT_VERSION)
2953 - Vendor Parameter Protection:
2955 U-Boot considers the values of the environment
2956 variables "serial#" (Board Serial Number) and
2957 "ethaddr" (Ethernet Address) to be parameters that
2958 are set once by the board vendor / manufacturer, and
2959 protects these variables from casual modification by
2960 the user. Once set, these variables are read-only,
2961 and write or delete attempts are rejected. You can
2962 change this behaviour:
2964 If CONFIG_ENV_OVERWRITE is #defined in your config
2965 file, the write protection for vendor parameters is
2966 completely disabled. Anybody can change or delete
2969 Alternatively, if you #define _both_ CONFIG_ETHADDR
2970 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2971 Ethernet address is installed in the environment,
2972 which can be changed exactly ONCE by the user. [The
2973 serial# is unaffected by this, i. e. it remains
2976 The same can be accomplished in a more flexible way
2977 for any variable by configuring the type of access
2978 to allow for those variables in the ".flags" variable
2979 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2984 Define this variable to enable the reservation of
2985 "protected RAM", i. e. RAM which is not overwritten
2986 by U-Boot. Define CONFIG_PRAM to hold the number of
2987 kB you want to reserve for pRAM. You can overwrite
2988 this default value by defining an environment
2989 variable "pram" to the number of kB you want to
2990 reserve. Note that the board info structure will
2991 still show the full amount of RAM. If pRAM is
2992 reserved, a new environment variable "mem" will
2993 automatically be defined to hold the amount of
2994 remaining RAM in a form that can be passed as boot
2995 argument to Linux, for instance like that:
2997 setenv bootargs ... mem=\${mem}
3000 This way you can tell Linux not to use this memory,
3001 either, which results in a memory region that will
3002 not be affected by reboots.
3004 *WARNING* If your board configuration uses automatic
3005 detection of the RAM size, you must make sure that
3006 this memory test is non-destructive. So far, the
3007 following board configurations are known to be
3010 IVMS8, IVML24, SPD8xx, TQM8xxL,
3011 HERMES, IP860, RPXlite, LWMON,
3014 - Access to physical memory region (> 4GB)
3015 Some basic support is provided for operations on memory not
3016 normally accessible to U-Boot - e.g. some architectures
3017 support access to more than 4GB of memory on 32-bit
3018 machines using physical address extension or similar.
3019 Define CONFIG_PHYSMEM to access this basic support, which
3020 currently only supports clearing the memory.
3025 Define this variable to stop the system in case of a
3026 fatal error, so that you have to reset it manually.
3027 This is probably NOT a good idea for an embedded
3028 system where you want the system to reboot
3029 automatically as fast as possible, but it may be
3030 useful during development since you can try to debug
3031 the conditions that lead to the situation.
3033 CONFIG_NET_RETRY_COUNT
3035 This variable defines the number of retries for
3036 network operations like ARP, RARP, TFTP, or BOOTP
3037 before giving up the operation. If not defined, a
3038 default value of 5 is used.
3042 Timeout waiting for an ARP reply in milliseconds.
3046 Timeout in milliseconds used in NFS protocol.
3047 If you encounter "ERROR: Cannot umount" in nfs command,
3048 try longer timeout such as
3049 #define CONFIG_NFS_TIMEOUT 10000UL
3051 - Command Interpreter:
3052 CONFIG_AUTO_COMPLETE
3054 Enable auto completion of commands using TAB.
3056 CONFIG_SYS_PROMPT_HUSH_PS2
3058 This defines the secondary prompt string, which is
3059 printed when the command interpreter needs more input
3060 to complete a command. Usually "> ".
3064 In the current implementation, the local variables
3065 space and global environment variables space are
3066 separated. Local variables are those you define by
3067 simply typing `name=value'. To access a local
3068 variable later on, you have write `$name' or
3069 `${name}'; to execute the contents of a variable
3070 directly type `$name' at the command prompt.
3072 Global environment variables are those you use
3073 setenv/printenv to work with. To run a command stored
3074 in such a variable, you need to use the run command,
3075 and you must not use the '$' sign to access them.
3077 To store commands and special characters in a
3078 variable, please use double quotation marks
3079 surrounding the whole text of the variable, instead
3080 of the backslashes before semicolons and special
3083 - Command Line Editing and History:
3084 CONFIG_CMDLINE_EDITING
3086 Enable editing and History functions for interactive
3087 command line input operations
3089 - Default Environment:
3090 CONFIG_EXTRA_ENV_SETTINGS
3092 Define this to contain any number of null terminated
3093 strings (variable = value pairs) that will be part of
3094 the default environment compiled into the boot image.
3096 For example, place something like this in your
3097 board's config file:
3099 #define CONFIG_EXTRA_ENV_SETTINGS \
3103 Warning: This method is based on knowledge about the
3104 internal format how the environment is stored by the
3105 U-Boot code. This is NOT an official, exported
3106 interface! Although it is unlikely that this format
3107 will change soon, there is no guarantee either.
3108 You better know what you are doing here.
3110 Note: overly (ab)use of the default environment is
3111 discouraged. Make sure to check other ways to preset
3112 the environment like the "source" command or the
3115 CONFIG_ENV_VARS_UBOOT_CONFIG
3117 Define this in order to add variables describing the
3118 U-Boot build configuration to the default environment.
3119 These will be named arch, cpu, board, vendor, and soc.
3121 Enabling this option will cause the following to be defined:
3129 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3131 Define this in order to add variables describing certain
3132 run-time determined information about the hardware to the
3133 environment. These will be named board_name, board_rev.
3135 CONFIG_DELAY_ENVIRONMENT
3137 Normally the environment is loaded when the board is
3138 initialised so that it is available to U-Boot. This inhibits
3139 that so that the environment is not available until
3140 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3141 this is instead controlled by the value of
3142 /config/load-environment.
3144 - DataFlash Support:
3145 CONFIG_HAS_DATAFLASH
3147 Defining this option enables DataFlash features and
3148 allows to read/write in Dataflash via the standard
3151 - Serial Flash support
3154 Defining this option enables SPI flash commands
3155 'sf probe/read/write/erase/update'.
3157 Usage requires an initial 'probe' to define the serial
3158 flash parameters, followed by read/write/erase/update
3161 The following defaults may be provided by the platform
3162 to handle the common case when only a single serial
3163 flash is present on the system.
3165 CONFIG_SF_DEFAULT_BUS Bus identifier
3166 CONFIG_SF_DEFAULT_CS Chip-select
3167 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3168 CONFIG_SF_DEFAULT_SPEED in Hz
3172 Define this option to include a destructive SPI flash
3175 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3177 Define this option to use the Bank addr/Extended addr
3178 support on SPI flashes which has size > 16Mbytes.
3180 CONFIG_SF_DUAL_FLASH Dual flash memories
3182 Define this option to use dual flash support where two flash
3183 memories can be connected with a given cs line.
3184 Currently Xilinx Zynq qspi supports these type of connections.
3186 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3187 enable the W#/Vpp signal to disable writing to the status
3188 register on ST MICRON flashes like the N25Q128.
3189 The status register write enable/disable bit, combined with
3190 the W#/VPP signal provides hardware data protection for the
3191 device as follows: When the enable/disable bit is set to 1,
3192 and the W#/VPP signal is driven LOW, the status register
3193 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3194 operation will not execute. The only way to exit this
3195 hardware-protected mode is to drive W#/VPP HIGH.
3197 - SystemACE Support:
3200 Adding this option adds support for Xilinx SystemACE
3201 chips attached via some sort of local bus. The address
3202 of the chip must also be defined in the
3203 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3205 #define CONFIG_SYSTEMACE
3206 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3208 When SystemACE support is added, the "ace" device type
3209 becomes available to the fat commands, i.e. fatls.
3211 - TFTP Fixed UDP Port:
3214 If this is defined, the environment variable tftpsrcp
3215 is used to supply the TFTP UDP source port value.
3216 If tftpsrcp isn't defined, the normal pseudo-random port
3217 number generator is used.
3219 Also, the environment variable tftpdstp is used to supply
3220 the TFTP UDP destination port value. If tftpdstp isn't
3221 defined, the normal port 69 is used.
3223 The purpose for tftpsrcp is to allow a TFTP server to
3224 blindly start the TFTP transfer using the pre-configured
3225 target IP address and UDP port. This has the effect of
3226 "punching through" the (Windows XP) firewall, allowing
3227 the remainder of the TFTP transfer to proceed normally.
3228 A better solution is to properly configure the firewall,
3229 but sometimes that is not allowed.
3234 This enables a generic 'hash' command which can produce
3235 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3239 Enable the hash verify command (hash -v). This adds to code
3242 CONFIG_SHA1 - This option enables support of hashing using SHA1
3243 algorithm. The hash is calculated in software.
3244 CONFIG_SHA256 - This option enables support of hashing using
3245 SHA256 algorithm. The hash is calculated in software.
3246 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3247 for SHA1/SHA256 hashing.
3248 This affects the 'hash' command and also the
3249 hash_lookup_algo() function.
3250 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3251 hardware-acceleration for SHA1/SHA256 progressive hashing.
3252 Data can be streamed in a block at a time and the hashing
3253 is performed in hardware.
3255 Note: There is also a sha1sum command, which should perhaps
3256 be deprecated in favour of 'hash sha1'.
3258 - Freescale i.MX specific commands:
3259 CONFIG_CMD_HDMIDETECT
3260 This enables 'hdmidet' command which returns true if an
3261 HDMI monitor is detected. This command is i.MX 6 specific.
3264 This enables the 'bmode' (bootmode) command for forcing
3265 a boot from specific media.
3267 This is useful for forcing the ROM's usb downloader to
3268 activate upon a watchdog reset which is nice when iterating
3269 on U-Boot. Using the reset button or running bmode normal
3270 will set it back to normal. This command currently
3271 supports i.MX53 and i.MX6.
3276 This enables the RSA algorithm used for FIT image verification
3277 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3279 The Modular Exponentiation algorithm in RSA is implemented using
3280 driver model. So CONFIG_DM needs to be enabled by default for this
3281 library to function.
3283 The signing part is build into mkimage regardless of this
3284 option. The software based modular exponentiation is built into
3285 mkimage irrespective of this option.
3287 - bootcount support:
3288 CONFIG_BOOTCOUNT_LIMIT
3290 This enables the bootcounter support, see:
3291 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3294 enable special bootcounter support on at91sam9xe based boards.
3296 enable special bootcounter support on blackfin based boards.
3298 enable special bootcounter support on da850 based boards.
3299 CONFIG_BOOTCOUNT_RAM
3300 enable support for the bootcounter in RAM
3301 CONFIG_BOOTCOUNT_I2C
3302 enable support for the bootcounter on an i2c (like RTC) device.
3303 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3304 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3306 CONFIG_BOOTCOUNT_ALEN = address len
3308 - Show boot progress:
3309 CONFIG_SHOW_BOOT_PROGRESS
3311 Defining this option allows to add some board-
3312 specific code (calling a user-provided function
3313 "show_boot_progress(int)") that enables you to show
3314 the system's boot progress on some display (for
3315 example, some LED's) on your board. At the moment,
3316 the following checkpoints are implemented:
3318 - Detailed boot stage timing
3320 Define this option to get detailed timing of each stage
3321 of the boot process.
3323 CONFIG_BOOTSTAGE_USER_COUNT
3324 This is the number of available user bootstage records.
3325 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3326 a new ID will be allocated from this stash. If you exceed
3327 the limit, recording will stop.
3329 CONFIG_BOOTSTAGE_REPORT
3330 Define this to print a report before boot, similar to this:
3332 Timer summary in microseconds:
3335 3,575,678 3,575,678 board_init_f start
3336 3,575,695 17 arch_cpu_init A9
3337 3,575,777 82 arch_cpu_init done
3338 3,659,598 83,821 board_init_r start
3339 3,910,375 250,777 main_loop
3340 29,916,167 26,005,792 bootm_start
3341 30,361,327 445,160 start_kernel
3343 CONFIG_CMD_BOOTSTAGE
3344 Add a 'bootstage' command which supports printing a report
3345 and un/stashing of bootstage data.
3347 CONFIG_BOOTSTAGE_FDT
3348 Stash the bootstage information in the FDT. A root 'bootstage'
3349 node is created with each bootstage id as a child. Each child
3350 has a 'name' property and either 'mark' containing the
3351 mark time in microsecond, or 'accum' containing the
3352 accumulated time for that bootstage id in microseconds.
3357 name = "board_init_f";
3366 Code in the Linux kernel can find this in /proc/devicetree.
3368 Legacy uImage format:
3371 1 common/cmd_bootm.c before attempting to boot an image
3372 -1 common/cmd_bootm.c Image header has bad magic number
3373 2 common/cmd_bootm.c Image header has correct magic number
3374 -2 common/cmd_bootm.c Image header has bad checksum
3375 3 common/cmd_bootm.c Image header has correct checksum
3376 -3 common/cmd_bootm.c Image data has bad checksum
3377 4 common/cmd_bootm.c Image data has correct checksum
3378 -4 common/cmd_bootm.c Image is for unsupported architecture
3379 5 common/cmd_bootm.c Architecture check OK
3380 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3381 6 common/cmd_bootm.c Image Type check OK
3382 -6 common/cmd_bootm.c gunzip uncompression error
3383 -7 common/cmd_bootm.c Unimplemented compression type
3384 7 common/cmd_bootm.c Uncompression OK
3385 8 common/cmd_bootm.c No uncompress/copy overwrite error
3386 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3388 9 common/image.c Start initial ramdisk verification
3389 -10 common/image.c Ramdisk header has bad magic number
3390 -11 common/image.c Ramdisk header has bad checksum
3391 10 common/image.c Ramdisk header is OK
3392 -12 common/image.c Ramdisk data has bad checksum
3393 11 common/image.c Ramdisk data has correct checksum
3394 12 common/image.c Ramdisk verification complete, start loading
3395 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3396 13 common/image.c Start multifile image verification
3397 14 common/image.c No initial ramdisk, no multifile, continue.
3399 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3401 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3402 -31 post/post.c POST test failed, detected by post_output_backlog()
3403 -32 post/post.c POST test failed, detected by post_run_single()
3405 34 common/cmd_doc.c before loading a Image from a DOC device
3406 -35 common/cmd_doc.c Bad usage of "doc" command
3407 35 common/cmd_doc.c correct usage of "doc" command
3408 -36 common/cmd_doc.c No boot device
3409 36 common/cmd_doc.c correct boot device
3410 -37 common/cmd_doc.c Unknown Chip ID on boot device
3411 37 common/cmd_doc.c correct chip ID found, device available
3412 -38 common/cmd_doc.c Read Error on boot device
3413 38 common/cmd_doc.c reading Image header from DOC device OK
3414 -39 common/cmd_doc.c Image header has bad magic number
3415 39 common/cmd_doc.c Image header has correct magic number
3416 -40 common/cmd_doc.c Error reading Image from DOC device
3417 40 common/cmd_doc.c Image header has correct magic number
3418 41 common/cmd_ide.c before loading a Image from a IDE device
3419 -42 common/cmd_ide.c Bad usage of "ide" command
3420 42 common/cmd_ide.c correct usage of "ide" command
3421 -43 common/cmd_ide.c No boot device
3422 43 common/cmd_ide.c boot device found
3423 -44 common/cmd_ide.c Device not available
3424 44 common/cmd_ide.c Device available
3425 -45 common/cmd_ide.c wrong partition selected
3426 45 common/cmd_ide.c partition selected
3427 -46 common/cmd_ide.c Unknown partition table
3428 46 common/cmd_ide.c valid partition table found
3429 -47 common/cmd_ide.c Invalid partition type
3430 47 common/cmd_ide.c correct partition type
3431 -48 common/cmd_ide.c Error reading Image Header on boot device
3432 48 common/cmd_ide.c reading Image Header from IDE device OK
3433 -49 common/cmd_ide.c Image header has bad magic number
3434 49 common/cmd_ide.c Image header has correct magic number
3435 -50 common/cmd_ide.c Image header has bad checksum
3436 50 common/cmd_ide.c Image header has correct checksum
3437 -51 common/cmd_ide.c Error reading Image from IDE device
3438 51 common/cmd_ide.c reading Image from IDE device OK
3439 52 common/cmd_nand.c before loading a Image from a NAND device
3440 -53 common/cmd_nand.c Bad usage of "nand" command
3441 53 common/cmd_nand.c correct usage of "nand" command
3442 -54 common/cmd_nand.c No boot device
3443 54 common/cmd_nand.c boot device found
3444 -55 common/cmd_nand.c Unknown Chip ID on boot device
3445 55 common/cmd_nand.c correct chip ID found, device available
3446 -56 common/cmd_nand.c Error reading Image Header on boot device
3447 56 common/cmd_nand.c reading Image Header from NAND device OK
3448 -57 common/cmd_nand.c Image header has bad magic number
3449 57 common/cmd_nand.c Image header has correct magic number
3450 -58 common/cmd_nand.c Error reading Image from NAND device
3451 58 common/cmd_nand.c reading Image from NAND device OK
3453 -60 common/env_common.c Environment has a bad CRC, using default
3455 64 net/eth.c starting with Ethernet configuration.
3456 -64 net/eth.c no Ethernet found.
3457 65 net/eth.c Ethernet found.
3459 -80 common/cmd_net.c usage wrong
3460 80 common/cmd_net.c before calling NetLoop()
3461 -81 common/cmd_net.c some error in NetLoop() occurred
3462 81 common/cmd_net.c NetLoop() back without error
3463 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3464 82 common/cmd_net.c trying automatic boot
3465 83 common/cmd_net.c running "source" command
3466 -83 common/cmd_net.c some error in automatic boot or "source" command
3467 84 common/cmd_net.c end without errors
3472 100 common/cmd_bootm.c Kernel FIT Image has correct format
3473 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3474 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3475 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3476 102 common/cmd_bootm.c Kernel unit name specified
3477 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3478 103 common/cmd_bootm.c Found configuration node
3479 104 common/cmd_bootm.c Got kernel subimage node offset
3480 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3481 105 common/cmd_bootm.c Kernel subimage hash verification OK
3482 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3483 106 common/cmd_bootm.c Architecture check OK
3484 -106 common/cmd_bootm.c Kernel subimage has wrong type
3485 107 common/cmd_bootm.c Kernel subimage type OK
3486 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3487 108 common/cmd_bootm.c Got kernel subimage data/size
3488 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3489 -109 common/cmd_bootm.c Can't get kernel subimage type
3490 -110 common/cmd_bootm.c Can't get kernel subimage comp
3491 -111 common/cmd_bootm.c Can't get kernel subimage os
3492 -112 common/cmd_bootm.c Can't get kernel subimage load address
3493 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3495 120 common/image.c Start initial ramdisk verification
3496 -120 common/image.c Ramdisk FIT image has incorrect format
3497 121 common/image.c Ramdisk FIT image has correct format
3498 122 common/image.c No ramdisk subimage unit name, using configuration
3499 -122 common/image.c Can't get configuration for ramdisk subimage
3500 123 common/image.c Ramdisk unit name specified
3501 -124 common/image.c Can't get ramdisk subimage node offset
3502 125 common/image.c Got ramdisk subimage node offset
3503 -125 common/image.c Ramdisk subimage hash verification failed
3504 126 common/image.c Ramdisk subimage hash verification OK
3505 -126 common/image.c Ramdisk subimage for unsupported architecture
3506 127 common/image.c Architecture check OK
3507 -127 common/image.c Can't get ramdisk subimage data/size
3508 128 common/image.c Got ramdisk subimage data/size
3509 129 common/image.c Can't get ramdisk load address
3510 -129 common/image.c Got ramdisk load address
3512 -130 common/cmd_doc.c Incorrect FIT image format
3513 131 common/cmd_doc.c FIT image format OK
3515 -140 common/cmd_ide.c Incorrect FIT image format
3516 141 common/cmd_ide.c FIT image format OK
3518 -150 common/cmd_nand.c Incorrect FIT image format
3519 151 common/cmd_nand.c FIT image format OK
3521 - legacy image format:
3522 CONFIG_IMAGE_FORMAT_LEGACY
3523 enables the legacy image format support in U-Boot.
3526 enabled if CONFIG_FIT_SIGNATURE is not defined.
3528 CONFIG_DISABLE_IMAGE_LEGACY
3529 disable the legacy image format
3531 This define is introduced, as the legacy image format is
3532 enabled per default for backward compatibility.
3534 - FIT image support:
3536 Enable support for the FIT uImage format.
3538 CONFIG_FIT_BEST_MATCH
3539 When no configuration is explicitly selected, default to the
3540 one whose fdt's compatibility field best matches that of
3541 U-Boot itself. A match is considered "best" if it matches the
3542 most specific compatibility entry of U-Boot's fdt's root node.
3543 The order of entries in the configuration's fdt is ignored.
3545 CONFIG_FIT_SIGNATURE
3546 This option enables signature verification of FIT uImages,
3547 using a hash signed and verified using RSA. If
3548 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3549 hashing is available using hardware, RSA library will use it.
3550 See doc/uImage.FIT/signature.txt for more details.
3552 WARNING: When relying on signed FIT images with required
3553 signature check the legacy image format is default
3554 disabled. If a board need legacy image format support
3555 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3557 CONFIG_FIT_DISABLE_SHA256
3558 Supporting SHA256 hashes has quite an impact on binary size.
3559 For constrained systems sha256 hash support can be disabled
3562 - Standalone program support:
3563 CONFIG_STANDALONE_LOAD_ADDR
3565 This option defines a board specific value for the
3566 address where standalone program gets loaded, thus
3567 overwriting the architecture dependent default
3570 - Frame Buffer Address:
3573 Define CONFIG_FB_ADDR if you want to use specific
3574 address for frame buffer. This is typically the case
3575 when using a graphics controller has separate video
3576 memory. U-Boot will then place the frame buffer at
3577 the given address instead of dynamically reserving it
3578 in system RAM by calling lcd_setmem(), which grabs
3579 the memory for the frame buffer depending on the
3580 configured panel size.
3582 Please see board_init_f function.
3584 - Automatic software updates via TFTP server
3586 CONFIG_UPDATE_TFTP_CNT_MAX
3587 CONFIG_UPDATE_TFTP_MSEC_MAX
3589 These options enable and control the auto-update feature;
3590 for a more detailed description refer to doc/README.update.
3592 - MTD Support (mtdparts command, UBI support)
3595 Adds the MTD device infrastructure from the Linux kernel.
3596 Needed for mtdparts command support.
3598 CONFIG_MTD_PARTITIONS
3600 Adds the MTD partitioning infrastructure from the Linux
3601 kernel. Needed for UBI support.
3603 CONFIG_MTD_NAND_VERIFY_WRITE
3604 verify if the written data is correct reread.
3609 Adds commands for interacting with MTD partitions formatted
3610 with the UBI flash translation layer
3612 Requires also defining CONFIG_RBTREE
3614 CONFIG_UBI_SILENCE_MSG
3616 Make the verbose messages from UBI stop printing. This leaves
3617 warnings and errors enabled.
3620 CONFIG_MTD_UBI_WL_THRESHOLD
3621 This parameter defines the maximum difference between the highest
3622 erase counter value and the lowest erase counter value of eraseblocks
3623 of UBI devices. When this threshold is exceeded, UBI starts performing
3624 wear leveling by means of moving data from eraseblock with low erase
3625 counter to eraseblocks with high erase counter.
3627 The default value should be OK for SLC NAND flashes, NOR flashes and
3628 other flashes which have eraseblock life-cycle 100000 or more.
3629 However, in case of MLC NAND flashes which typically have eraseblock
3630 life-cycle less than 10000, the threshold should be lessened (e.g.,
3631 to 128 or 256, although it does not have to be power of 2).
3635 CONFIG_MTD_UBI_BEB_LIMIT
3636 This option specifies the maximum bad physical eraseblocks UBI
3637 expects on the MTD device (per 1024 eraseblocks). If the
3638 underlying flash does not admit of bad eraseblocks (e.g. NOR
3639 flash), this value is ignored.
3641 NAND datasheets often specify the minimum and maximum NVM
3642 (Number of Valid Blocks) for the flashes' endurance lifetime.
3643 The maximum expected bad eraseblocks per 1024 eraseblocks
3644 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3645 which gives 20 for most NANDs (MaxNVB is basically the total
3646 count of eraseblocks on the chip).
3648 To put it differently, if this value is 20, UBI will try to
3649 reserve about 1.9% of physical eraseblocks for bad blocks
3650 handling. And that will be 1.9% of eraseblocks on the entire
3651 NAND chip, not just the MTD partition UBI attaches. This means
3652 that if you have, say, a NAND flash chip admits maximum 40 bad
3653 eraseblocks, and it is split on two MTD partitions of the same
3654 size, UBI will reserve 40 eraseblocks when attaching a
3659 CONFIG_MTD_UBI_FASTMAP
3660 Fastmap is a mechanism which allows attaching an UBI device
3661 in nearly constant time. Instead of scanning the whole MTD device it
3662 only has to locate a checkpoint (called fastmap) on the device.
3663 The on-flash fastmap contains all information needed to attach
3664 the device. Using fastmap makes only sense on large devices where
3665 attaching by scanning takes long. UBI will not automatically install
3666 a fastmap on old images, but you can set the UBI parameter
3667 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3668 that fastmap-enabled images are still usable with UBI implementations
3669 without fastmap support. On typical flash devices the whole fastmap
3670 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3672 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3673 Set this parameter to enable fastmap automatically on images
3680 Adds commands for interacting with UBI volumes formatted as
3681 UBIFS. UBIFS is read-only in u-boot.
3683 Requires UBI support as well as CONFIG_LZO
3685 CONFIG_UBIFS_SILENCE_MSG
3687 Make the verbose messages from UBIFS stop printing. This leaves
3688 warnings and errors enabled.
3692 Enable building of SPL globally.
3695 LDSCRIPT for linking the SPL binary.
3697 CONFIG_SPL_MAX_FOOTPRINT
3698 Maximum size in memory allocated to the SPL, BSS included.
3699 When defined, the linker checks that the actual memory
3700 used by SPL from _start to __bss_end does not exceed it.
3701 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3702 must not be both defined at the same time.
3705 Maximum size of the SPL image (text, data, rodata, and
3706 linker lists sections), BSS excluded.
3707 When defined, the linker checks that the actual size does
3710 CONFIG_SPL_TEXT_BASE
3711 TEXT_BASE for linking the SPL binary.
3713 CONFIG_SPL_RELOC_TEXT_BASE
3714 Address to relocate to. If unspecified, this is equal to
3715 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3717 CONFIG_SPL_BSS_START_ADDR
3718 Link address for the BSS within the SPL binary.
3720 CONFIG_SPL_BSS_MAX_SIZE
3721 Maximum size in memory allocated to the SPL BSS.
3722 When defined, the linker checks that the actual memory used
3723 by SPL from __bss_start to __bss_end does not exceed it.
3724 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3725 must not be both defined at the same time.
3728 Adress of the start of the stack SPL will use
3730 CONFIG_SPL_RELOC_STACK
3731 Adress of the start of the stack SPL will use after
3732 relocation. If unspecified, this is equal to
3735 CONFIG_SYS_SPL_MALLOC_START
3736 Starting address of the malloc pool used in SPL.
3738 CONFIG_SYS_SPL_MALLOC_SIZE
3739 The size of the malloc pool used in SPL.
3741 CONFIG_SPL_FRAMEWORK
3742 Enable the SPL framework under common/. This framework
3743 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3744 NAND loading of the Linux Kernel.
3747 Enable booting directly to an OS from SPL.
3748 See also: doc/README.falcon
3750 CONFIG_SPL_DISPLAY_PRINT
3751 For ARM, enable an optional function to print more information
3752 about the running system.
3754 CONFIG_SPL_INIT_MINIMAL
3755 Arch init code should be built for a very small image
3757 CONFIG_SPL_LIBCOMMON_SUPPORT
3758 Support for common/libcommon.o in SPL binary
3760 CONFIG_SPL_LIBDISK_SUPPORT
3761 Support for disk/libdisk.o in SPL binary
3763 CONFIG_SPL_I2C_SUPPORT
3764 Support for drivers/i2c/libi2c.o in SPL binary
3766 CONFIG_SPL_GPIO_SUPPORT
3767 Support for drivers/gpio/libgpio.o in SPL binary
3769 CONFIG_SPL_MMC_SUPPORT
3770 Support for drivers/mmc/libmmc.o in SPL binary
3772 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3773 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3774 Address and partition on the MMC to load U-Boot from
3775 when the MMC is being used in raw mode.
3777 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3778 Partition on the MMC to load U-Boot from when the MMC is being
3781 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3782 Sector to load kernel uImage from when MMC is being
3783 used in raw mode (for Falcon mode)
3785 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3786 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3787 Sector and number of sectors to load kernel argument
3788 parameters from when MMC is being used in raw mode
3791 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3792 Partition on the MMC to load U-Boot from when the MMC is being
3795 CONFIG_SPL_FAT_SUPPORT
3796 Support for fs/fat/libfat.o in SPL binary
3798 CONFIG_SPL_EXT_SUPPORT
3799 Support for EXT filesystem in SPL binary
3801 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3802 Filename to read to load U-Boot when reading from filesystem
3804 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3805 Filename to read to load kernel uImage when reading
3806 from filesystem (for Falcon mode)
3808 CONFIG_SPL_FS_LOAD_ARGS_NAME
3809 Filename to read to load kernel argument parameters
3810 when reading from filesystem (for Falcon mode)
3812 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3813 Set this for NAND SPL on PPC mpc83xx targets, so that
3814 start.S waits for the rest of the SPL to load before
3815 continuing (the hardware starts execution after just
3816 loading the first page rather than the full 4K).
3818 CONFIG_SPL_SKIP_RELOCATE
3819 Avoid SPL relocation
3821 CONFIG_SPL_NAND_BASE
3822 Include nand_base.c in the SPL. Requires
3823 CONFIG_SPL_NAND_DRIVERS.
3825 CONFIG_SPL_NAND_DRIVERS
3826 SPL uses normal NAND drivers, not minimal drivers.
3829 Include standard software ECC in the SPL
3831 CONFIG_SPL_NAND_SIMPLE
3832 Support for NAND boot using simple NAND drivers that
3833 expose the cmd_ctrl() interface.
3835 CONFIG_SPL_MTD_SUPPORT
3836 Support for the MTD subsystem within SPL. Useful for
3837 environment on NAND support within SPL.
3839 CONFIG_SPL_NAND_RAW_ONLY
3840 Support to boot only raw u-boot.bin images. Use this only
3841 if you need to save space.
3843 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3844 Set for the SPL on PPC mpc8xxx targets, support for
3845 drivers/ddr/fsl/libddr.o in SPL binary.
3847 CONFIG_SPL_COMMON_INIT_DDR
3848 Set for common ddr init with serial presence detect in
3851 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3852 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3853 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3854 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3855 CONFIG_SYS_NAND_ECCBYTES
3856 Defines the size and behavior of the NAND that SPL uses
3859 CONFIG_SPL_NAND_BOOT
3860 Add support NAND boot
3862 CONFIG_SYS_NAND_U_BOOT_OFFS
3863 Location in NAND to read U-Boot from
3865 CONFIG_SYS_NAND_U_BOOT_DST
3866 Location in memory to load U-Boot to
3868 CONFIG_SYS_NAND_U_BOOT_SIZE
3869 Size of image to load
3871 CONFIG_SYS_NAND_U_BOOT_START
3872 Entry point in loaded image to jump to
3874 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3875 Define this if you need to first read the OOB and then the
3876 data. This is used, for example, on davinci platforms.
3878 CONFIG_SPL_OMAP3_ID_NAND
3879 Support for an OMAP3-specific set of functions to return the
3880 ID and MFR of the first attached NAND chip, if present.
3882 CONFIG_SPL_SERIAL_SUPPORT
3883 Support for drivers/serial/libserial.o in SPL binary
3885 CONFIG_SPL_SPI_FLASH_SUPPORT
3886 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3888 CONFIG_SPL_SPI_SUPPORT
3889 Support for drivers/spi/libspi.o in SPL binary
3891 CONFIG_SPL_RAM_DEVICE
3892 Support for running image already present in ram, in SPL binary
3894 CONFIG_SPL_LIBGENERIC_SUPPORT
3895 Support for lib/libgeneric.o in SPL binary
3897 CONFIG_SPL_ENV_SUPPORT
3898 Support for the environment operating in SPL binary
3900 CONFIG_SPL_NET_SUPPORT
3901 Support for the net/libnet.o in SPL binary.
3902 It conflicts with SPL env from storage medium specified by
3903 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3906 Image offset to which the SPL should be padded before appending
3907 the SPL payload. By default, this is defined as
3908 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3909 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3910 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3913 Final target image containing SPL and payload. Some SPLs
3914 use an arch-specific makefile fragment instead, for
3915 example if more than one image needs to be produced.
3917 CONFIG_FIT_SPL_PRINT
3918 Printing information about a FIT image adds quite a bit of
3919 code to SPL. So this is normally disabled in SPL. Use this
3920 option to re-enable it. This will affect the output of the
3921 bootm command when booting a FIT image.
3925 Enable building of TPL globally.
3928 Image offset to which the TPL should be padded before appending
3929 the TPL payload. By default, this is defined as
3930 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3931 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3932 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3937 [so far only for SMDK2400 boards]
3939 - Modem support enable:
3940 CONFIG_MODEM_SUPPORT
3942 - RTS/CTS Flow control enable:
3945 - Modem debug support:
3946 CONFIG_MODEM_SUPPORT_DEBUG
3948 Enables debugging stuff (char screen[1024], dbg())
3949 for modem support. Useful only with BDI2000.
3951 - Interrupt support (PPC):
3953 There are common interrupt_init() and timer_interrupt()
3954 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3955 for CPU specific initialization. interrupt_init_cpu()
3956 should set decrementer_count to appropriate value. If
3957 CPU resets decrementer automatically after interrupt
3958 (ppc4xx) it should set decrementer_count to zero.
3959 timer_interrupt() calls timer_interrupt_cpu() for CPU
3960 specific handling. If board has watchdog / status_led
3961 / other_activity_monitor it works automatically from
3962 general timer_interrupt().
3966 In the target system modem support is enabled when a
3967 specific key (key combination) is pressed during
3968 power-on. Otherwise U-Boot will boot normally
3969 (autoboot). The key_pressed() function is called from
3970 board_init(). Currently key_pressed() is a dummy
3971 function, returning 1 and thus enabling modem
3974 If there are no modem init strings in the
3975 environment, U-Boot proceed to autoboot; the
3976 previous output (banner, info printfs) will be
3979 See also: doc/README.Modem
3981 Board initialization settings:
3982 ------------------------------
3984 During Initialization u-boot calls a number of board specific functions
3985 to allow the preparation of board specific prerequisites, e.g. pin setup
3986 before drivers are initialized. To enable these callbacks the
3987 following configuration macros have to be defined. Currently this is
3988 architecture specific, so please check arch/your_architecture/lib/board.c
3989 typically in board_init_f() and board_init_r().
3991 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3992 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3993 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3994 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3996 Configuration Settings:
3997 -----------------------
3999 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
4000 Optionally it can be defined to support 64-bit memory commands.
4002 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
4003 undefine this when you're short of memory.
4005 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
4006 width of the commands listed in the 'help' command output.
4008 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
4009 prompt for user input.
4011 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
4013 - CONFIG_SYS_PBSIZE: Buffer size for Console output
4015 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
4017 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
4018 the application (usually a Linux kernel) when it is
4021 - CONFIG_SYS_BAUDRATE_TABLE:
4022 List of legal baudrate settings for this board.
4024 - CONFIG_SYS_CONSOLE_INFO_QUIET
4025 Suppress display of console information at boot.
4027 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4028 If the board specific function
4029 extern int overwrite_console (void);
4030 returns 1, the stdin, stderr and stdout are switched to the
4031 serial port, else the settings in the environment are used.
4033 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4034 Enable the call to overwrite_console().
4036 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4037 Enable overwrite of previous console environment settings.
4039 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4040 Begin and End addresses of the area used by the
4043 - CONFIG_SYS_ALT_MEMTEST:
4044 Enable an alternate, more extensive memory test.
4046 - CONFIG_SYS_MEMTEST_SCRATCH:
4047 Scratch address used by the alternate memory test
4048 You only need to set this if address zero isn't writeable
4050 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4051 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4052 this specified memory area will get subtracted from the top
4053 (end) of RAM and won't get "touched" at all by U-Boot. By
4054 fixing up gd->ram_size the Linux kernel should gets passed
4055 the now "corrected" memory size and won't touch it either.
4056 This should work for arch/ppc and arch/powerpc. Only Linux
4057 board ports in arch/powerpc with bootwrapper support that
4058 recalculate the memory size from the SDRAM controller setup
4059 will have to get fixed in Linux additionally.
4061 This option can be used as a workaround for the 440EPx/GRx
4062 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4065 WARNING: Please make sure that this value is a multiple of
4066 the Linux page size (normally 4k). If this is not the case,
4067 then the end address of the Linux memory will be located at a
4068 non page size aligned address and this could cause major
4071 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4072 Enable temporary baudrate change while serial download
4074 - CONFIG_SYS_SDRAM_BASE:
4075 Physical start address of SDRAM. _Must_ be 0 here.
4077 - CONFIG_SYS_MBIO_BASE:
4078 Physical start address of Motherboard I/O (if using a
4081 - CONFIG_SYS_FLASH_BASE:
4082 Physical start address of Flash memory.
4084 - CONFIG_SYS_MONITOR_BASE:
4085 Physical start address of boot monitor code (set by
4086 make config files to be same as the text base address
4087 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4088 CONFIG_SYS_FLASH_BASE when booting from flash.
4090 - CONFIG_SYS_MONITOR_LEN:
4091 Size of memory reserved for monitor code, used to
4092 determine _at_compile_time_ (!) if the environment is
4093 embedded within the U-Boot image, or in a separate
4096 - CONFIG_SYS_MALLOC_LEN:
4097 Size of DRAM reserved for malloc() use.
4099 - CONFIG_SYS_MALLOC_F_LEN
4100 Size of the malloc() pool for use before relocation. If
4101 this is defined, then a very simple malloc() implementation
4102 will become available before relocation. The address is just
4103 below the global data, and the stack is moved down to make
4106 This feature allocates regions with increasing addresses
4107 within the region. calloc() is supported, but realloc()
4108 is not available. free() is supported but does nothing.
4109 The memory will be freed (or in fact just forgotten) when
4110 U-Boot relocates itself.
4112 Pre-relocation malloc() is only supported on ARM and sandbox
4113 at present but is fairly easy to enable for other archs.
4115 - CONFIG_SYS_MALLOC_SIMPLE
4116 Provides a simple and small malloc() and calloc() for those
4117 boards which do not use the full malloc in SPL (which is
4118 enabled with CONFIG_SYS_SPL_MALLOC_START).
4120 - CONFIG_SYS_NONCACHED_MEMORY:
4121 Size of non-cached memory area. This area of memory will be
4122 typically located right below the malloc() area and mapped
4123 uncached in the MMU. This is useful for drivers that would
4124 otherwise require a lot of explicit cache maintenance. For
4125 some drivers it's also impossible to properly maintain the
4126 cache. For example if the regions that need to be flushed
4127 are not a multiple of the cache-line size, *and* padding
4128 cannot be allocated between the regions to align them (i.e.
4129 if the HW requires a contiguous array of regions, and the
4130 size of each region is not cache-aligned), then a flush of
4131 one region may result in overwriting data that hardware has
4132 written to another region in the same cache-line. This can
4133 happen for example in network drivers where descriptors for
4134 buffers are typically smaller than the CPU cache-line (e.g.
4135 16 bytes vs. 32 or 64 bytes).
4137 Non-cached memory is only supported on 32-bit ARM at present.
4139 - CONFIG_SYS_BOOTM_LEN:
4140 Normally compressed uImages are limited to an
4141 uncompressed size of 8 MBytes. If this is not enough,
4142 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4143 to adjust this setting to your needs.
4145 - CONFIG_SYS_BOOTMAPSZ:
4146 Maximum size of memory mapped by the startup code of
4147 the Linux kernel; all data that must be processed by
4148 the Linux kernel (bd_info, boot arguments, FDT blob if
4149 used) must be put below this limit, unless "bootm_low"
4150 environment variable is defined and non-zero. In such case
4151 all data for the Linux kernel must be between "bootm_low"
4152 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4153 variable "bootm_mapsize" will override the value of
4154 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4155 then the value in "bootm_size" will be used instead.
4157 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4158 Enable initrd_high functionality. If defined then the
4159 initrd_high feature is enabled and the bootm ramdisk subcommand
4162 - CONFIG_SYS_BOOT_GET_CMDLINE:
4163 Enables allocating and saving kernel cmdline in space between
4164 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4166 - CONFIG_SYS_BOOT_GET_KBD:
4167 Enables allocating and saving a kernel copy of the bd_info in
4168 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4170 - CONFIG_SYS_MAX_FLASH_BANKS:
4171 Max number of Flash memory banks
4173 - CONFIG_SYS_MAX_FLASH_SECT:
4174 Max number of sectors on a Flash chip
4176 - CONFIG_SYS_FLASH_ERASE_TOUT:
4177 Timeout for Flash erase operations (in ms)
4179 - CONFIG_SYS_FLASH_WRITE_TOUT:
4180 Timeout for Flash write operations (in ms)
4182 - CONFIG_SYS_FLASH_LOCK_TOUT
4183 Timeout for Flash set sector lock bit operation (in ms)
4185 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4186 Timeout for Flash clear lock bits operation (in ms)
4188 - CONFIG_SYS_FLASH_PROTECTION
4189 If defined, hardware flash sectors protection is used
4190 instead of U-Boot software protection.
4192 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4194 Enable TFTP transfers directly to flash memory;
4195 without this option such a download has to be
4196 performed in two steps: (1) download to RAM, and (2)
4197 copy from RAM to flash.
4199 The two-step approach is usually more reliable, since
4200 you can check if the download worked before you erase
4201 the flash, but in some situations (when system RAM is
4202 too limited to allow for a temporary copy of the
4203 downloaded image) this option may be very useful.
4205 - CONFIG_SYS_FLASH_CFI:
4206 Define if the flash driver uses extra elements in the
4207 common flash structure for storing flash geometry.
4209 - CONFIG_FLASH_CFI_DRIVER
4210 This option also enables the building of the cfi_flash driver
4211 in the drivers directory
4213 - CONFIG_FLASH_CFI_MTD
4214 This option enables the building of the cfi_mtd driver
4215 in the drivers directory. The driver exports CFI flash
4218 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4219 Use buffered writes to flash.
4221 - CONFIG_FLASH_SPANSION_S29WS_N
4222 s29ws-n MirrorBit flash has non-standard addresses for buffered
4225 - CONFIG_SYS_FLASH_QUIET_TEST
4226 If this option is defined, the common CFI flash doesn't
4227 print it's warning upon not recognized FLASH banks. This
4228 is useful, if some of the configured banks are only
4229 optionally available.
4231 - CONFIG_FLASH_SHOW_PROGRESS
4232 If defined (must be an integer), print out countdown
4233 digits and dots. Recommended value: 45 (9..1) for 80
4234 column displays, 15 (3..1) for 40 column displays.
4236 - CONFIG_FLASH_VERIFY
4237 If defined, the content of the flash (destination) is compared
4238 against the source after the write operation. An error message
4239 will be printed when the contents are not identical.
4240 Please note that this option is useless in nearly all cases,
4241 since such flash programming errors usually are detected earlier
4242 while unprotecting/erasing/programming. Please only enable
4243 this option if you really know what you are doing.
4245 - CONFIG_SYS_RX_ETH_BUFFER:
4246 Defines the number of Ethernet receive buffers. On some
4247 Ethernet controllers it is recommended to set this value
4248 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4249 buffers can be full shortly after enabling the interface
4250 on high Ethernet traffic.
4251 Defaults to 4 if not defined.
4253 - CONFIG_ENV_MAX_ENTRIES
4255 Maximum number of entries in the hash table that is used
4256 internally to store the environment settings. The default
4257 setting is supposed to be generous and should work in most
4258 cases. This setting can be used to tune behaviour; see
4259 lib/hashtable.c for details.
4261 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4262 - CONFIG_ENV_FLAGS_LIST_STATIC
4263 Enable validation of the values given to environment variables when
4264 calling env set. Variables can be restricted to only decimal,
4265 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4266 the variables can also be restricted to IP address or MAC address.
4268 The format of the list is:
4269 type_attribute = [s|d|x|b|i|m]
4270 access_attribute = [a|r|o|c]
4271 attributes = type_attribute[access_attribute]
4272 entry = variable_name[:attributes]
4275 The type attributes are:
4276 s - String (default)
4279 b - Boolean ([1yYtT|0nNfF])
4283 The access attributes are:
4289 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4290 Define this to a list (string) to define the ".flags"
4291 environment variable in the default or embedded environment.
4293 - CONFIG_ENV_FLAGS_LIST_STATIC
4294 Define this to a list (string) to define validation that
4295 should be done if an entry is not found in the ".flags"
4296 environment variable. To override a setting in the static
4297 list, simply add an entry for the same variable name to the
4300 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4301 If defined, don't allow the -f switch to env set override variable
4304 - CONFIG_SYS_GENERIC_BOARD
4305 This selects the architecture-generic board system instead of the
4306 architecture-specific board files. It is intended to move boards
4307 to this new framework over time. Defining this will disable the
4308 arch/foo/lib/board.c file and use common/board_f.c and
4309 common/board_r.c instead. To use this option your architecture
4310 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4311 its config.mk file). If you find problems enabling this option on
4312 your board please report the problem and send patches!
4314 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4315 This is set by OMAP boards for the max time that reset should
4316 be asserted. See doc/README.omap-reset-time for details on how
4317 the value can be calculated on a given board.
4320 If stdint.h is available with your toolchain you can define this
4321 option to enable it. You can provide option 'USE_STDINT=1' when
4322 building U-Boot to enable this.
4324 The following definitions that deal with the placement and management
4325 of environment data (variable area); in general, we support the
4326 following configurations:
4328 - CONFIG_BUILD_ENVCRC:
4330 Builds up envcrc with the target environment so that external utils
4331 may easily extract it and embed it in final U-Boot images.
4333 - CONFIG_ENV_IS_IN_FLASH:
4335 Define this if the environment is in flash memory.
4337 a) The environment occupies one whole flash sector, which is
4338 "embedded" in the text segment with the U-Boot code. This
4339 happens usually with "bottom boot sector" or "top boot
4340 sector" type flash chips, which have several smaller
4341 sectors at the start or the end. For instance, such a
4342 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4343 such a case you would place the environment in one of the
4344 4 kB sectors - with U-Boot code before and after it. With
4345 "top boot sector" type flash chips, you would put the
4346 environment in one of the last sectors, leaving a gap
4347 between U-Boot and the environment.
4349 - CONFIG_ENV_OFFSET:
4351 Offset of environment data (variable area) to the
4352 beginning of flash memory; for instance, with bottom boot
4353 type flash chips the second sector can be used: the offset
4354 for this sector is given here.
4356 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4360 This is just another way to specify the start address of
4361 the flash sector containing the environment (instead of
4364 - CONFIG_ENV_SECT_SIZE:
4366 Size of the sector containing the environment.
4369 b) Sometimes flash chips have few, equal sized, BIG sectors.
4370 In such a case you don't want to spend a whole sector for
4375 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4376 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4377 of this flash sector for the environment. This saves
4378 memory for the RAM copy of the environment.
4380 It may also save flash memory if you decide to use this
4381 when your environment is "embedded" within U-Boot code,
4382 since then the remainder of the flash sector could be used
4383 for U-Boot code. It should be pointed out that this is
4384 STRONGLY DISCOURAGED from a robustness point of view:
4385 updating the environment in flash makes it always
4386 necessary to erase the WHOLE sector. If something goes
4387 wrong before the contents has been restored from a copy in
4388 RAM, your target system will be dead.
4390 - CONFIG_ENV_ADDR_REDUND
4391 CONFIG_ENV_SIZE_REDUND
4393 These settings describe a second storage area used to hold
4394 a redundant copy of the environment data, so that there is
4395 a valid backup copy in case there is a power failure during
4396 a "saveenv" operation.
4398 BE CAREFUL! Any changes to the flash layout, and some changes to the
4399 source code will make it necessary to adapt <board>/u-boot.lds*
4403 - CONFIG_ENV_IS_IN_NVRAM:
4405 Define this if you have some non-volatile memory device
4406 (NVRAM, battery buffered SRAM) which you want to use for the
4412 These two #defines are used to determine the memory area you
4413 want to use for environment. It is assumed that this memory
4414 can just be read and written to, without any special
4417 BE CAREFUL! The first access to the environment happens quite early
4418 in U-Boot initialization (when we try to get the setting of for the
4419 console baudrate). You *MUST* have mapped your NVRAM area then, or
4422 Please note that even with NVRAM we still use a copy of the
4423 environment in RAM: we could work on NVRAM directly, but we want to
4424 keep settings there always unmodified except somebody uses "saveenv"
4425 to save the current settings.
4428 - CONFIG_ENV_IS_IN_EEPROM:
4430 Use this if you have an EEPROM or similar serial access
4431 device and a driver for it.
4433 - CONFIG_ENV_OFFSET:
4436 These two #defines specify the offset and size of the
4437 environment area within the total memory of your EEPROM.
4439 - CONFIG_SYS_I2C_EEPROM_ADDR:
4440 If defined, specified the chip address of the EEPROM device.
4441 The default address is zero.
4443 - CONFIG_SYS_I2C_EEPROM_BUS:
4444 If defined, specified the i2c bus of the EEPROM device.
4446 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4447 If defined, the number of bits used to address bytes in a
4448 single page in the EEPROM device. A 64 byte page, for example
4449 would require six bits.
4451 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4452 If defined, the number of milliseconds to delay between
4453 page writes. The default is zero milliseconds.
4455 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4456 The length in bytes of the EEPROM memory array address. Note
4457 that this is NOT the chip address length!
4459 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4460 EEPROM chips that implement "address overflow" are ones
4461 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4462 address and the extra bits end up in the "chip address" bit
4463 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4466 Note that we consider the length of the address field to
4467 still be one byte because the extra address bits are hidden
4468 in the chip address.
4470 - CONFIG_SYS_EEPROM_SIZE:
4471 The size in bytes of the EEPROM device.
4473 - CONFIG_ENV_EEPROM_IS_ON_I2C
4474 define this, if you have I2C and SPI activated, and your
4475 EEPROM, which holds the environment, is on the I2C bus.
4477 - CONFIG_I2C_ENV_EEPROM_BUS
4478 if you have an Environment on an EEPROM reached over
4479 I2C muxes, you can define here, how to reach this
4480 EEPROM. For example:
4482 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4484 EEPROM which holds the environment, is reached over
4485 a pca9547 i2c mux with address 0x70, channel 3.
4487 - CONFIG_ENV_IS_IN_DATAFLASH:
4489 Define this if you have a DataFlash memory device which you
4490 want to use for the environment.
4492 - CONFIG_ENV_OFFSET:
4496 These three #defines specify the offset and size of the
4497 environment area within the total memory of your DataFlash placed
4498 at the specified address.
4500 - CONFIG_ENV_IS_IN_SPI_FLASH:
4502 Define this if you have a SPI Flash memory device which you
4503 want to use for the environment.
4505 - CONFIG_ENV_OFFSET:
4508 These two #defines specify the offset and size of the
4509 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4510 aligned to an erase sector boundary.
4512 - CONFIG_ENV_SECT_SIZE:
4514 Define the SPI flash's sector size.
4516 - CONFIG_ENV_OFFSET_REDUND (optional):
4518 This setting describes a second storage area of CONFIG_ENV_SIZE
4519 size used to hold a redundant copy of the environment data, so
4520 that there is a valid backup copy in case there is a power failure
4521 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4522 aligned to an erase sector boundary.
4524 - CONFIG_ENV_SPI_BUS (optional):
4525 - CONFIG_ENV_SPI_CS (optional):
4527 Define the SPI bus and chip select. If not defined they will be 0.
4529 - CONFIG_ENV_SPI_MAX_HZ (optional):
4531 Define the SPI max work clock. If not defined then use 1MHz.
4533 - CONFIG_ENV_SPI_MODE (optional):
4535 Define the SPI work mode. If not defined then use SPI_MODE_3.
4537 - CONFIG_ENV_IS_IN_REMOTE:
4539 Define this if you have a remote memory space which you
4540 want to use for the local device's environment.
4545 These two #defines specify the address and size of the
4546 environment area within the remote memory space. The
4547 local device can get the environment from remote memory
4548 space by SRIO or PCIE links.
4550 BE CAREFUL! For some special cases, the local device can not use
4551 "saveenv" command. For example, the local device will get the
4552 environment stored in a remote NOR flash by SRIO or PCIE link,
4553 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4555 - CONFIG_ENV_IS_IN_NAND:
4557 Define this if you have a NAND device which you want to use
4558 for the environment.
4560 - CONFIG_ENV_OFFSET:
4563 These two #defines specify the offset and size of the environment
4564 area within the first NAND device. CONFIG_ENV_OFFSET must be
4565 aligned to an erase block boundary.
4567 - CONFIG_ENV_OFFSET_REDUND (optional):
4569 This setting describes a second storage area of CONFIG_ENV_SIZE
4570 size used to hold a redundant copy of the environment data, so
4571 that there is a valid backup copy in case there is a power failure
4572 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4573 aligned to an erase block boundary.
4575 - CONFIG_ENV_RANGE (optional):
4577 Specifies the length of the region in which the environment
4578 can be written. This should be a multiple of the NAND device's
4579 block size. Specifying a range with more erase blocks than
4580 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4581 the range to be avoided.
4583 - CONFIG_ENV_OFFSET_OOB (optional):
4585 Enables support for dynamically retrieving the offset of the
4586 environment from block zero's out-of-band data. The
4587 "nand env.oob" command can be used to record this offset.
4588 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4589 using CONFIG_ENV_OFFSET_OOB.
4591 - CONFIG_NAND_ENV_DST
4593 Defines address in RAM to which the nand_spl code should copy the
4594 environment. If redundant environment is used, it will be copied to
4595 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4597 - CONFIG_ENV_IS_IN_UBI:
4599 Define this if you have an UBI volume that you want to use for the
4600 environment. This has the benefit of wear-leveling the environment
4601 accesses, which is important on NAND.
4603 - CONFIG_ENV_UBI_PART:
4605 Define this to a string that is the mtd partition containing the UBI.
4607 - CONFIG_ENV_UBI_VOLUME:
4609 Define this to the name of the volume that you want to store the
4612 - CONFIG_ENV_UBI_VOLUME_REDUND:
4614 Define this to the name of another volume to store a second copy of
4615 the environment in. This will enable redundant environments in UBI.
4616 It is assumed that both volumes are in the same MTD partition.
4618 - CONFIG_UBI_SILENCE_MSG
4619 - CONFIG_UBIFS_SILENCE_MSG
4621 You will probably want to define these to avoid a really noisy system
4622 when storing the env in UBI.
4624 - CONFIG_ENV_IS_IN_FAT:
4625 Define this if you want to use the FAT file system for the environment.
4627 - FAT_ENV_INTERFACE:
4629 Define this to a string that is the name of the block device.
4631 - FAT_ENV_DEV_AND_PART:
4633 Define this to a string to specify the partition of the device. It can
4636 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4637 - "D:P": device D partition P. Error occurs if device D has no
4640 - "D" or "D:": device D partition 1 if device D has partition
4641 table, or the whole device D if has no partition
4643 - "D:auto": first partition in device D with bootable flag set.
4644 If none, first valid partition in device D. If no
4645 partition table then means device D.
4649 It's a string of the FAT file name. This file use to store the
4653 This should be defined. Otherwise it cannot save the environment file.
4655 - CONFIG_ENV_IS_IN_MMC:
4657 Define this if you have an MMC device which you want to use for the
4660 - CONFIG_SYS_MMC_ENV_DEV:
4662 Specifies which MMC device the environment is stored in.
4664 - CONFIG_SYS_MMC_ENV_PART (optional):
4666 Specifies which MMC partition the environment is stored in. If not
4667 set, defaults to partition 0, the user area. Common values might be
4668 1 (first MMC boot partition), 2 (second MMC boot partition).
4670 - CONFIG_ENV_OFFSET:
4673 These two #defines specify the offset and size of the environment
4674 area within the specified MMC device.
4676 If offset is positive (the usual case), it is treated as relative to
4677 the start of the MMC partition. If offset is negative, it is treated
4678 as relative to the end of the MMC partition. This can be useful if
4679 your board may be fitted with different MMC devices, which have
4680 different sizes for the MMC partitions, and you always want the
4681 environment placed at the very end of the partition, to leave the
4682 maximum possible space before it, to store other data.
4684 These two values are in units of bytes, but must be aligned to an
4685 MMC sector boundary.
4687 - CONFIG_ENV_OFFSET_REDUND (optional):
4689 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4690 hold a redundant copy of the environment data. This provides a
4691 valid backup copy in case the other copy is corrupted, e.g. due
4692 to a power failure during a "saveenv" operation.
4694 This value may also be positive or negative; this is handled in the
4695 same way as CONFIG_ENV_OFFSET.
4697 This value is also in units of bytes, but must also be aligned to
4698 an MMC sector boundary.
4700 - CONFIG_ENV_SIZE_REDUND (optional):
4702 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4703 set. If this value is set, it must be set to the same value as
4706 - CONFIG_SYS_SPI_INIT_OFFSET
4708 Defines offset to the initial SPI buffer area in DPRAM. The
4709 area is used at an early stage (ROM part) if the environment
4710 is configured to reside in the SPI EEPROM: We need a 520 byte
4711 scratch DPRAM area. It is used between the two initialization
4712 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4713 to be a good choice since it makes it far enough from the
4714 start of the data area as well as from the stack pointer.
4716 Please note that the environment is read-only until the monitor
4717 has been relocated to RAM and a RAM copy of the environment has been
4718 created; also, when using EEPROM you will have to use getenv_f()
4719 until then to read environment variables.
4721 The environment is protected by a CRC32 checksum. Before the monitor
4722 is relocated into RAM, as a result of a bad CRC you will be working
4723 with the compiled-in default environment - *silently*!!! [This is
4724 necessary, because the first environment variable we need is the
4725 "baudrate" setting for the console - if we have a bad CRC, we don't
4726 have any device yet where we could complain.]
4728 Note: once the monitor has been relocated, then it will complain if
4729 the default environment is used; a new CRC is computed as soon as you
4730 use the "saveenv" command to store a valid environment.
4732 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4733 Echo the inverted Ethernet link state to the fault LED.
4735 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4736 also needs to be defined.
4738 - CONFIG_SYS_FAULT_MII_ADDR:
4739 MII address of the PHY to check for the Ethernet link state.
4741 - CONFIG_NS16550_MIN_FUNCTIONS:
4742 Define this if you desire to only have use of the NS16550_init
4743 and NS16550_putc functions for the serial driver located at
4744 drivers/serial/ns16550.c. This option is useful for saving
4745 space for already greatly restricted images, including but not
4746 limited to NAND_SPL configurations.
4748 - CONFIG_DISPLAY_BOARDINFO
4749 Display information about the board that U-Boot is running on
4750 when U-Boot starts up. The board function checkboard() is called
4753 - CONFIG_DISPLAY_BOARDINFO_LATE
4754 Similar to the previous option, but display this information
4755 later, once stdio is running and output goes to the LCD, if
4758 - CONFIG_BOARD_SIZE_LIMIT:
4759 Maximum size of the U-Boot image. When defined, the
4760 build system checks that the actual size does not
4763 Low Level (hardware related) configuration options:
4764 ---------------------------------------------------
4766 - CONFIG_SYS_CACHELINE_SIZE:
4767 Cache Line Size of the CPU.
4769 - CONFIG_SYS_DEFAULT_IMMR:
4770 Default address of the IMMR after system reset.
4772 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4773 and RPXsuper) to be able to adjust the position of
4774 the IMMR register after a reset.
4776 - CONFIG_SYS_CCSRBAR_DEFAULT:
4777 Default (power-on reset) physical address of CCSR on Freescale
4780 - CONFIG_SYS_CCSRBAR:
4781 Virtual address of CCSR. On a 32-bit build, this is typically
4782 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4784 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4785 for cross-platform code that uses that macro instead.
4787 - CONFIG_SYS_CCSRBAR_PHYS:
4788 Physical address of CCSR. CCSR can be relocated to a new
4789 physical address, if desired. In this case, this macro should
4790 be set to that address. Otherwise, it should be set to the
4791 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4792 is typically relocated on 36-bit builds. It is recommended
4793 that this macro be defined via the _HIGH and _LOW macros:
4795 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4796 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4798 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4799 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4800 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4801 used in assembly code, so it must not contain typecasts or
4802 integer size suffixes (e.g. "ULL").
4804 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4805 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4806 used in assembly code, so it must not contain typecasts or
4807 integer size suffixes (e.g. "ULL").
4809 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4810 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4811 forced to a value that ensures that CCSR is not relocated.
4813 - Floppy Disk Support:
4814 CONFIG_SYS_FDC_DRIVE_NUMBER
4816 the default drive number (default value 0)
4818 CONFIG_SYS_ISA_IO_STRIDE
4820 defines the spacing between FDC chipset registers
4823 CONFIG_SYS_ISA_IO_OFFSET
4825 defines the offset of register from address. It
4826 depends on which part of the data bus is connected to
4827 the FDC chipset. (default value 0)
4829 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4830 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4833 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4834 fdc_hw_init() is called at the beginning of the FDC
4835 setup. fdc_hw_init() must be provided by the board
4836 source code. It is used to make hardware-dependent
4840 Most IDE controllers were designed to be connected with PCI
4841 interface. Only few of them were designed for AHB interface.
4842 When software is doing ATA command and data transfer to
4843 IDE devices through IDE-AHB controller, some additional
4844 registers accessing to these kind of IDE-AHB controller
4847 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4848 DO NOT CHANGE unless you know exactly what you're
4849 doing! (11-4) [MPC8xx/82xx systems only]
4851 - CONFIG_SYS_INIT_RAM_ADDR:
4853 Start address of memory area that can be used for
4854 initial data and stack; please note that this must be
4855 writable memory that is working WITHOUT special
4856 initialization, i. e. you CANNOT use normal RAM which
4857 will become available only after programming the
4858 memory controller and running certain initialization
4861 U-Boot uses the following memory types:
4862 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4863 - MPC824X: data cache
4864 - PPC4xx: data cache
4866 - CONFIG_SYS_GBL_DATA_OFFSET:
4868 Offset of the initial data structure in the memory
4869 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4870 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4871 data is located at the end of the available space
4872 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4873 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4874 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4875 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4878 On the MPC824X (or other systems that use the data
4879 cache for initial memory) the address chosen for
4880 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4881 point to an otherwise UNUSED address space between
4882 the top of RAM and the start of the PCI space.
4884 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4886 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4888 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4890 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4892 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4894 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4896 - CONFIG_SYS_OR_TIMING_SDRAM:
4899 - CONFIG_SYS_MAMR_PTA:
4900 periodic timer for refresh
4902 - CONFIG_SYS_DER: Debug Event Register (37-47)
4904 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4905 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4906 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4907 CONFIG_SYS_BR1_PRELIM:
4908 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4910 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4911 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4912 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4913 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4915 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4916 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4917 Machine Mode Register and Memory Periodic Timer
4918 Prescaler definitions (SDRAM timing)
4920 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4921 enable I2C microcode relocation patch (MPC8xx);
4922 define relocation offset in DPRAM [DSP2]
4924 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4925 enable SMC microcode relocation patch (MPC8xx);
4926 define relocation offset in DPRAM [SMC1]
4928 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4929 enable SPI microcode relocation patch (MPC8xx);
4930 define relocation offset in DPRAM [SCC4]
4932 - CONFIG_SYS_USE_OSCCLK:
4933 Use OSCM clock mode on MBX8xx board. Be careful,
4934 wrong setting might damage your board. Read
4935 doc/README.MBX before setting this variable!
4937 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4938 Offset of the bootmode word in DPRAM used by post
4939 (Power On Self Tests). This definition overrides
4940 #define'd default value in commproc.h resp.
4943 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4944 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4945 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4946 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4947 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4948 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4949 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4950 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4951 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4953 - CONFIG_PCI_DISABLE_PCIE:
4954 Disable PCI-Express on systems where it is supported but not
4957 - CONFIG_PCI_ENUM_ONLY
4958 Only scan through and get the devices on the buses.
4959 Don't do any setup work, presumably because someone or
4960 something has already done it, and we don't need to do it
4961 a second time. Useful for platforms that are pre-booted
4962 by coreboot or similar.
4964 - CONFIG_PCI_INDIRECT_BRIDGE:
4965 Enable support for indirect PCI bridges.
4968 Chip has SRIO or not
4971 Board has SRIO 1 port available
4974 Board has SRIO 2 port available
4976 - CONFIG_SRIO_PCIE_BOOT_MASTER
4977 Board can support master function for Boot from SRIO and PCIE
4979 - CONFIG_SYS_SRIOn_MEM_VIRT:
4980 Virtual Address of SRIO port 'n' memory region
4982 - CONFIG_SYS_SRIOn_MEM_PHYS:
4983 Physical Address of SRIO port 'n' memory region
4985 - CONFIG_SYS_SRIOn_MEM_SIZE:
4986 Size of SRIO port 'n' memory region
4988 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4989 Defined to tell the NAND controller that the NAND chip is using
4991 Not all NAND drivers use this symbol.
4992 Example of drivers that use it:
4993 - drivers/mtd/nand/ndfc.c
4994 - drivers/mtd/nand/mxc_nand.c
4996 - CONFIG_SYS_NDFC_EBC0_CFG
4997 Sets the EBC0_CFG register for the NDFC. If not defined
4998 a default value will be used.
5001 Get DDR timing information from an I2C EEPROM. Common
5002 with pluggable memory modules such as SODIMMs
5005 I2C address of the SPD EEPROM
5007 - CONFIG_SYS_SPD_BUS_NUM
5008 If SPD EEPROM is on an I2C bus other than the first
5009 one, specify here. Note that the value must resolve
5010 to something your driver can deal with.
5012 - CONFIG_SYS_DDR_RAW_TIMING
5013 Get DDR timing information from other than SPD. Common with
5014 soldered DDR chips onboard without SPD. DDR raw timing
5015 parameters are extracted from datasheet and hard-coded into
5016 header files or board specific files.
5018 - CONFIG_FSL_DDR_INTERACTIVE
5019 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5021 - CONFIG_FSL_DDR_SYNC_REFRESH
5022 Enable sync of refresh for multiple controllers.
5024 - CONFIG_SYS_83XX_DDR_USES_CS0
5025 Only for 83xx systems. If specified, then DDR should
5026 be configured using CS0 and CS1 instead of CS2 and CS3.
5028 - CONFIG_ETHER_ON_FEC[12]
5029 Define to enable FEC[12] on a 8xx series processor.
5031 - CONFIG_FEC[12]_PHY
5032 Define to the hardcoded PHY address which corresponds
5033 to the given FEC; i. e.
5034 #define CONFIG_FEC1_PHY 4
5035 means that the PHY with address 4 is connected to FEC1
5037 When set to -1, means to probe for first available.
5039 - CONFIG_FEC[12]_PHY_NORXERR
5040 The PHY does not have a RXERR line (RMII only).
5041 (so program the FEC to ignore it).
5044 Enable RMII mode for all FECs.
5045 Note that this is a global option, we can't
5046 have one FEC in standard MII mode and another in RMII mode.
5048 - CONFIG_CRC32_VERIFY
5049 Add a verify option to the crc32 command.
5052 => crc32 -v <address> <count> <crc32>
5054 Where address/count indicate a memory area
5055 and crc32 is the correct crc32 which the
5059 Add the "loopw" memory command. This only takes effect if
5060 the memory commands are activated globally (CONFIG_CMD_MEM).
5063 Add the "mdc" and "mwc" memory commands. These are cyclic
5068 This command will print 4 bytes (10,11,12,13) each 500 ms.
5070 => mwc.l 100 12345678 10
5071 This command will write 12345678 to address 100 all 10 ms.
5073 This only takes effect if the memory commands are activated
5074 globally (CONFIG_CMD_MEM).
5076 - CONFIG_SKIP_LOWLEVEL_INIT
5077 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5078 low level initializations (like setting up the memory
5079 controller) are omitted and/or U-Boot does not
5080 relocate itself into RAM.
5082 Normally this variable MUST NOT be defined. The only
5083 exception is when U-Boot is loaded (to RAM) by some
5084 other boot loader or by a debugger which performs
5085 these initializations itself.
5088 Modifies the behaviour of start.S when compiling a loader
5089 that is executed before the actual U-Boot. E.g. when
5090 compiling a NAND SPL.
5093 Modifies the behaviour of start.S when compiling a loader
5094 that is executed after the SPL and before the actual U-Boot.
5095 It is loaded by the SPL.
5097 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5098 Only for 85xx systems. If this variable is specified, the section
5099 .resetvec is not kept and the section .bootpg is placed in the
5100 previous 4k of the .text section.
5102 - CONFIG_ARCH_MAP_SYSMEM
5103 Generally U-Boot (and in particular the md command) uses
5104 effective address. It is therefore not necessary to regard
5105 U-Boot address as virtual addresses that need to be translated
5106 to physical addresses. However, sandbox requires this, since
5107 it maintains its own little RAM buffer which contains all
5108 addressable memory. This option causes some memory accesses
5109 to be mapped through map_sysmem() / unmap_sysmem().
5111 - CONFIG_USE_ARCH_MEMCPY
5112 CONFIG_USE_ARCH_MEMSET
5113 If these options are used a optimized version of memcpy/memset will
5114 be used if available. These functions may be faster under some
5115 conditions but may increase the binary size.
5117 - CONFIG_X86_RESET_VECTOR
5118 If defined, the x86 reset vector code is included. This is not
5119 needed when U-Boot is running from Coreboot.
5122 Defines the MPU clock speed (in MHz).
5124 NOTE : currently only supported on AM335x platforms.
5126 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5127 Enables the RTC32K OSC on AM33xx based plattforms
5129 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5130 Option to disable subpage write in NAND driver
5131 driver that uses this:
5132 drivers/mtd/nand/davinci_nand.c
5134 Freescale QE/FMAN Firmware Support:
5135 -----------------------------------
5137 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5138 loading of "firmware", which is encoded in the QE firmware binary format.
5139 This firmware often needs to be loaded during U-Boot booting, so macros
5140 are used to identify the storage device (NOR flash, SPI, etc) and the address
5143 - CONFIG_SYS_FMAN_FW_ADDR
5144 The address in the storage device where the FMAN microcode is located. The
5145 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5148 - CONFIG_SYS_QE_FW_ADDR
5149 The address in the storage device where the QE microcode is located. The
5150 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5153 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5154 The maximum possible size of the firmware. The firmware binary format
5155 has a field that specifies the actual size of the firmware, but it
5156 might not be possible to read any part of the firmware unless some
5157 local storage is allocated to hold the entire firmware first.
5159 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5160 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5161 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5162 virtual address in NOR flash.
5164 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5165 Specifies that QE/FMAN firmware is located in NAND flash.
5166 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5168 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5169 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5170 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5172 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5173 Specifies that QE/FMAN firmware is located on the primary SPI
5174 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5176 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5177 Specifies that QE/FMAN firmware is located in the remote (master)
5178 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5179 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5180 window->master inbound window->master LAW->the ucode address in
5181 master's memory space.
5183 Freescale Layerscape Management Complex Firmware Support:
5184 ---------------------------------------------------------
5185 The Freescale Layerscape Management Complex (MC) supports the loading of
5187 This firmware often needs to be loaded during U-Boot booting, so macros
5188 are used to identify the storage device (NOR flash, SPI, etc) and the address
5191 - CONFIG_FSL_MC_ENET
5192 Enable the MC driver for Layerscape SoCs.
5194 - CONFIG_SYS_LS_MC_FW_ADDR
5195 The address in the storage device where the firmware is located. The
5196 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5199 - CONFIG_SYS_LS_MC_FW_LENGTH
5200 The maximum possible size of the firmware. The firmware binary format
5201 has a field that specifies the actual size of the firmware, but it
5202 might not be possible to read any part of the firmware unless some
5203 local storage is allocated to hold the entire firmware first.
5205 - CONFIG_SYS_LS_MC_FW_IN_NOR
5206 Specifies that MC firmware is located in NOR flash, mapped as
5207 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5208 virtual address in NOR flash.
5210 Building the Software:
5211 ======================
5213 Building U-Boot has been tested in several native build environments
5214 and in many different cross environments. Of course we cannot support
5215 all possibly existing versions of cross development tools in all
5216 (potentially obsolete) versions. In case of tool chain problems we
5217 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5218 which is extensively used to build and test U-Boot.
5220 If you are not using a native environment, it is assumed that you
5221 have GNU cross compiling tools available in your path. In this case,
5222 you must set the environment variable CROSS_COMPILE in your shell.
5223 Note that no changes to the Makefile or any other source files are
5224 necessary. For example using the ELDK on a 4xx CPU, please enter:
5226 $ CROSS_COMPILE=ppc_4xx-
5227 $ export CROSS_COMPILE
5229 Note: If you wish to generate Windows versions of the utilities in
5230 the tools directory you can use the MinGW toolchain
5231 (http://www.mingw.org). Set your HOST tools to the MinGW
5232 toolchain and execute 'make tools'. For example:
5234 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5236 Binaries such as tools/mkimage.exe will be created which can
5237 be executed on computers running Windows.
5239 U-Boot is intended to be simple to build. After installing the
5240 sources you must configure U-Boot for one specific board type. This
5245 where "NAME_defconfig" is the name of one of the existing configu-
5246 rations; see boards.cfg for supported names.
5248 Note: for some board special configuration names may exist; check if
5249 additional information is available from the board vendor; for
5250 instance, the TQM823L systems are available without (standard)
5251 or with LCD support. You can select such additional "features"
5252 when choosing the configuration, i. e.
5254 make TQM823L_defconfig
5255 - will configure for a plain TQM823L, i. e. no LCD support
5257 make TQM823L_LCD_defconfig
5258 - will configure for a TQM823L with U-Boot console on LCD
5263 Finally, type "make all", and you should get some working U-Boot
5264 images ready for download to / installation on your system:
5266 - "u-boot.bin" is a raw binary image
5267 - "u-boot" is an image in ELF binary format
5268 - "u-boot.srec" is in Motorola S-Record format
5270 By default the build is performed locally and the objects are saved
5271 in the source directory. One of the two methods can be used to change
5272 this behavior and build U-Boot to some external directory:
5274 1. Add O= to the make command line invocations:
5276 make O=/tmp/build distclean
5277 make O=/tmp/build NAME_defconfig
5278 make O=/tmp/build all
5280 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5282 export KBUILD_OUTPUT=/tmp/build
5287 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5291 Please be aware that the Makefiles assume you are using GNU make, so
5292 for instance on NetBSD you might need to use "gmake" instead of
5296 If the system board that you have is not listed, then you will need
5297 to port U-Boot to your hardware platform. To do this, follow these
5300 1. Add a new configuration option for your board to the toplevel
5301 "boards.cfg" file, using the existing entries as examples.
5302 Follow the instructions there to keep the boards in order.
5303 2. Create a new directory to hold your board specific code. Add any
5304 files you need. In your board directory, you will need at least
5305 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5306 3. Create a new configuration file "include/configs/<board>.h" for
5308 3. If you're porting U-Boot to a new CPU, then also create a new
5309 directory to hold your CPU specific code. Add any files you need.
5310 4. Run "make <board>_defconfig" with your new name.
5311 5. Type "make", and you should get a working "u-boot.srec" file
5312 to be installed on your target system.
5313 6. Debug and solve any problems that might arise.
5314 [Of course, this last step is much harder than it sounds.]
5317 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5318 ==============================================================
5320 If you have modified U-Boot sources (for instance added a new board
5321 or support for new devices, a new CPU, etc.) you are expected to
5322 provide feedback to the other developers. The feedback normally takes
5323 the form of a "patch", i. e. a context diff against a certain (latest
5324 official or latest in the git repository) version of U-Boot sources.
5326 But before you submit such a patch, please verify that your modifi-
5327 cation did not break existing code. At least make sure that *ALL* of
5328 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5329 just run the "MAKEALL" script, which will configure and build U-Boot
5330 for ALL supported system. Be warned, this will take a while. You can
5331 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5332 environment variable to the script, i. e. to use the ELDK cross tools
5335 CROSS_COMPILE=ppc_8xx- MAKEALL
5337 or to build on a native PowerPC system you can type
5339 CROSS_COMPILE=' ' MAKEALL
5341 When using the MAKEALL script, the default behaviour is to build
5342 U-Boot in the source directory. This location can be changed by
5343 setting the BUILD_DIR environment variable. Also, for each target
5344 built, the MAKEALL script saves two log files (<target>.ERR and
5345 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5346 location can be changed by setting the MAKEALL_LOGDIR environment
5347 variable. For example:
5349 export BUILD_DIR=/tmp/build
5350 export MAKEALL_LOGDIR=/tmp/log
5351 CROSS_COMPILE=ppc_8xx- MAKEALL
5353 With the above settings build objects are saved in the /tmp/build,
5354 log files are saved in the /tmp/log and the source tree remains clean
5355 during the whole build process.
5358 See also "U-Boot Porting Guide" below.
5361 Monitor Commands - Overview:
5362 ============================
5364 go - start application at address 'addr'
5365 run - run commands in an environment variable
5366 bootm - boot application image from memory
5367 bootp - boot image via network using BootP/TFTP protocol
5368 bootz - boot zImage from memory
5369 tftpboot- boot image via network using TFTP protocol
5370 and env variables "ipaddr" and "serverip"
5371 (and eventually "gatewayip")
5372 tftpput - upload a file via network using TFTP protocol
5373 rarpboot- boot image via network using RARP/TFTP protocol
5374 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5375 loads - load S-Record file over serial line
5376 loadb - load binary file over serial line (kermit mode)
5378 mm - memory modify (auto-incrementing)
5379 nm - memory modify (constant address)
5380 mw - memory write (fill)
5382 cmp - memory compare
5383 crc32 - checksum calculation
5384 i2c - I2C sub-system
5385 sspi - SPI utility commands
5386 base - print or set address offset
5387 printenv- print environment variables
5388 setenv - set environment variables
5389 saveenv - save environment variables to persistent storage
5390 protect - enable or disable FLASH write protection
5391 erase - erase FLASH memory
5392 flinfo - print FLASH memory information
5393 nand - NAND memory operations (see doc/README.nand)
5394 bdinfo - print Board Info structure
5395 iminfo - print header information for application image
5396 coninfo - print console devices and informations
5397 ide - IDE sub-system
5398 loop - infinite loop on address range
5399 loopw - infinite write loop on address range
5400 mtest - simple RAM test
5401 icache - enable or disable instruction cache
5402 dcache - enable or disable data cache
5403 reset - Perform RESET of the CPU
5404 echo - echo args to console
5405 version - print monitor version
5406 help - print online help
5407 ? - alias for 'help'
5410 Monitor Commands - Detailed Description:
5411 ========================================
5415 For now: just type "help <command>".
5418 Environment Variables:
5419 ======================
5421 U-Boot supports user configuration using Environment Variables which
5422 can be made persistent by saving to Flash memory.
5424 Environment Variables are set using "setenv", printed using
5425 "printenv", and saved to Flash using "saveenv". Using "setenv"
5426 without a value can be used to delete a variable from the
5427 environment. As long as you don't save the environment you are
5428 working with an in-memory copy. In case the Flash area containing the
5429 environment is erased by accident, a default environment is provided.
5431 Some configuration options can be set using Environment Variables.
5433 List of environment variables (most likely not complete):
5435 baudrate - see CONFIG_BAUDRATE
5437 bootdelay - see CONFIG_BOOTDELAY
5439 bootcmd - see CONFIG_BOOTCOMMAND
5441 bootargs - Boot arguments when booting an RTOS image
5443 bootfile - Name of the image to load with TFTP
5445 bootm_low - Memory range available for image processing in the bootm
5446 command can be restricted. This variable is given as
5447 a hexadecimal number and defines lowest address allowed
5448 for use by the bootm command. See also "bootm_size"
5449 environment variable. Address defined by "bootm_low" is
5450 also the base of the initial memory mapping for the Linux
5451 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5454 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5455 This variable is given as a hexadecimal number and it
5456 defines the size of the memory region starting at base
5457 address bootm_low that is accessible by the Linux kernel
5458 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5459 as the default value if it is defined, and bootm_size is
5462 bootm_size - Memory range available for image processing in the bootm
5463 command can be restricted. This variable is given as
5464 a hexadecimal number and defines the size of the region
5465 allowed for use by the bootm command. See also "bootm_low"
5466 environment variable.
5468 updatefile - Location of the software update file on a TFTP server, used
5469 by the automatic software update feature. Please refer to
5470 documentation in doc/README.update for more details.
5472 autoload - if set to "no" (any string beginning with 'n'),
5473 "bootp" will just load perform a lookup of the
5474 configuration from the BOOTP server, but not try to
5475 load any image using TFTP
5477 autostart - if set to "yes", an image loaded using the "bootp",
5478 "rarpboot", "tftpboot" or "diskboot" commands will
5479 be automatically started (by internally calling
5482 If set to "no", a standalone image passed to the
5483 "bootm" command will be copied to the load address
5484 (and eventually uncompressed), but NOT be started.
5485 This can be used to load and uncompress arbitrary
5488 fdt_high - if set this restricts the maximum address that the
5489 flattened device tree will be copied into upon boot.
5490 For example, if you have a system with 1 GB memory
5491 at physical address 0x10000000, while Linux kernel
5492 only recognizes the first 704 MB as low memory, you
5493 may need to set fdt_high as 0x3C000000 to have the
5494 device tree blob be copied to the maximum address
5495 of the 704 MB low memory, so that Linux kernel can
5496 access it during the boot procedure.
5498 If this is set to the special value 0xFFFFFFFF then
5499 the fdt will not be copied at all on boot. For this
5500 to work it must reside in writable memory, have
5501 sufficient padding on the end of it for u-boot to
5502 add the information it needs into it, and the memory
5503 must be accessible by the kernel.
5505 fdtcontroladdr- if set this is the address of the control flattened
5506 device tree used by U-Boot when CONFIG_OF_CONTROL is
5509 i2cfast - (PPC405GP|PPC405EP only)
5510 if set to 'y' configures Linux I2C driver for fast
5511 mode (400kHZ). This environment variable is used in
5512 initialization code. So, for changes to be effective
5513 it must be saved and board must be reset.
5515 initrd_high - restrict positioning of initrd images:
5516 If this variable is not set, initrd images will be
5517 copied to the highest possible address in RAM; this
5518 is usually what you want since it allows for
5519 maximum initrd size. If for some reason you want to
5520 make sure that the initrd image is loaded below the
5521 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5522 variable to a value of "no" or "off" or "0".
5523 Alternatively, you can set it to a maximum upper
5524 address to use (U-Boot will still check that it
5525 does not overwrite the U-Boot stack and data).
5527 For instance, when you have a system with 16 MB
5528 RAM, and want to reserve 4 MB from use by Linux,
5529 you can do this by adding "mem=12M" to the value of
5530 the "bootargs" variable. However, now you must make
5531 sure that the initrd image is placed in the first
5532 12 MB as well - this can be done with
5534 setenv initrd_high 00c00000
5536 If you set initrd_high to 0xFFFFFFFF, this is an
5537 indication to U-Boot that all addresses are legal
5538 for the Linux kernel, including addresses in flash
5539 memory. In this case U-Boot will NOT COPY the
5540 ramdisk at all. This may be useful to reduce the
5541 boot time on your system, but requires that this
5542 feature is supported by your Linux kernel.
5544 ipaddr - IP address; needed for tftpboot command
5546 loadaddr - Default load address for commands like "bootp",
5547 "rarpboot", "tftpboot", "loadb" or "diskboot"
5549 loads_echo - see CONFIG_LOADS_ECHO
5551 serverip - TFTP server IP address; needed for tftpboot command
5553 bootretry - see CONFIG_BOOT_RETRY_TIME
5555 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5557 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5559 ethprime - controls which interface is used first.
5561 ethact - controls which interface is currently active.
5562 For example you can do the following
5564 => setenv ethact FEC
5565 => ping 192.168.0.1 # traffic sent on FEC
5566 => setenv ethact SCC
5567 => ping 10.0.0.1 # traffic sent on SCC
5569 ethrotate - When set to "no" U-Boot does not go through all
5570 available network interfaces.
5571 It just stays at the currently selected interface.
5573 netretry - When set to "no" each network operation will
5574 either succeed or fail without retrying.
5575 When set to "once" the network operation will
5576 fail when all the available network interfaces
5577 are tried once without success.
5578 Useful on scripts which control the retry operation
5581 npe_ucode - set load address for the NPE microcode
5583 silent_linux - If set then Linux will be told to boot silently, by
5584 changing the console to be empty. If "yes" it will be
5585 made silent. If "no" it will not be made silent. If
5586 unset, then it will be made silent if the U-Boot console
5589 tftpsrcport - If this is set, the value is used for TFTP's
5592 tftpdstport - If this is set, the value is used for TFTP's UDP
5593 destination port instead of the Well Know Port 69.
5595 tftpblocksize - Block size to use for TFTP transfers; if not set,
5596 we use the TFTP server's default block size
5598 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5599 seconds, minimum value is 1000 = 1 second). Defines
5600 when a packet is considered to be lost so it has to
5601 be retransmitted. The default is 5000 = 5 seconds.
5602 Lowering this value may make downloads succeed
5603 faster in networks with high packet loss rates or
5604 with unreliable TFTP servers.
5606 vlan - When set to a value < 4095 the traffic over
5607 Ethernet is encapsulated/received over 802.1q
5610 The following image location variables contain the location of images
5611 used in booting. The "Image" column gives the role of the image and is
5612 not an environment variable name. The other columns are environment
5613 variable names. "File Name" gives the name of the file on a TFTP
5614 server, "RAM Address" gives the location in RAM the image will be
5615 loaded to, and "Flash Location" gives the image's address in NOR
5616 flash or offset in NAND flash.
5618 *Note* - these variables don't have to be defined for all boards, some
5619 boards currenlty use other variables for these purposes, and some
5620 boards use these variables for other purposes.
5622 Image File Name RAM Address Flash Location
5623 ----- --------- ----------- --------------
5624 u-boot u-boot u-boot_addr_r u-boot_addr
5625 Linux kernel bootfile kernel_addr_r kernel_addr
5626 device tree blob fdtfile fdt_addr_r fdt_addr
5627 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5629 The following environment variables may be used and automatically
5630 updated by the network boot commands ("bootp" and "rarpboot"),
5631 depending the information provided by your boot server:
5633 bootfile - see above
5634 dnsip - IP address of your Domain Name Server
5635 dnsip2 - IP address of your secondary Domain Name Server
5636 gatewayip - IP address of the Gateway (Router) to use
5637 hostname - Target hostname
5639 netmask - Subnet Mask
5640 rootpath - Pathname of the root filesystem on the NFS server
5641 serverip - see above
5644 There are two special Environment Variables:
5646 serial# - contains hardware identification information such
5647 as type string and/or serial number
5648 ethaddr - Ethernet address
5650 These variables can be set only once (usually during manufacturing of
5651 the board). U-Boot refuses to delete or overwrite these variables
5652 once they have been set once.
5655 Further special Environment Variables:
5657 ver - Contains the U-Boot version string as printed
5658 with the "version" command. This variable is
5659 readonly (see CONFIG_VERSION_VARIABLE).
5662 Please note that changes to some configuration parameters may take
5663 only effect after the next boot (yes, that's just like Windoze :-).
5666 Callback functions for environment variables:
5667 ---------------------------------------------
5669 For some environment variables, the behavior of u-boot needs to change
5670 when their values are changed. This functionality allows functions to
5671 be associated with arbitrary variables. On creation, overwrite, or
5672 deletion, the callback will provide the opportunity for some side
5673 effect to happen or for the change to be rejected.
5675 The callbacks are named and associated with a function using the
5676 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5678 These callbacks are associated with variables in one of two ways. The
5679 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5680 in the board configuration to a string that defines a list of
5681 associations. The list must be in the following format:
5683 entry = variable_name[:callback_name]
5686 If the callback name is not specified, then the callback is deleted.
5687 Spaces are also allowed anywhere in the list.
5689 Callbacks can also be associated by defining the ".callbacks" variable
5690 with the same list format above. Any association in ".callbacks" will
5691 override any association in the static list. You can define
5692 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5693 ".callbacks" environment variable in the default or embedded environment.
5696 Command Line Parsing:
5697 =====================
5699 There are two different command line parsers available with U-Boot:
5700 the old "simple" one, and the much more powerful "hush" shell:
5702 Old, simple command line parser:
5703 --------------------------------
5705 - supports environment variables (through setenv / saveenv commands)
5706 - several commands on one line, separated by ';'
5707 - variable substitution using "... ${name} ..." syntax
5708 - special characters ('$', ';') can be escaped by prefixing with '\',
5710 setenv bootcmd bootm \${address}
5711 - You can also escape text by enclosing in single apostrophes, for example:
5712 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5717 - similar to Bourne shell, with control structures like
5718 if...then...else...fi, for...do...done; while...do...done,
5719 until...do...done, ...
5720 - supports environment ("global") variables (through setenv / saveenv
5721 commands) and local shell variables (through standard shell syntax
5722 "name=value"); only environment variables can be used with "run"
5728 (1) If a command line (or an environment variable executed by a "run"
5729 command) contains several commands separated by semicolon, and
5730 one of these commands fails, then the remaining commands will be
5733 (2) If you execute several variables with one call to run (i. e.
5734 calling run with a list of variables as arguments), any failing
5735 command will cause "run" to terminate, i. e. the remaining
5736 variables are not executed.
5738 Note for Redundant Ethernet Interfaces:
5739 =======================================
5741 Some boards come with redundant Ethernet interfaces; U-Boot supports
5742 such configurations and is capable of automatic selection of a
5743 "working" interface when needed. MAC assignment works as follows:
5745 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5746 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5747 "eth1addr" (=>eth1), "eth2addr", ...
5749 If the network interface stores some valid MAC address (for instance
5750 in SROM), this is used as default address if there is NO correspon-
5751 ding setting in the environment; if the corresponding environment
5752 variable is set, this overrides the settings in the card; that means:
5754 o If the SROM has a valid MAC address, and there is no address in the
5755 environment, the SROM's address is used.
5757 o If there is no valid address in the SROM, and a definition in the
5758 environment exists, then the value from the environment variable is
5761 o If both the SROM and the environment contain a MAC address, and
5762 both addresses are the same, this MAC address is used.
5764 o If both the SROM and the environment contain a MAC address, and the
5765 addresses differ, the value from the environment is used and a
5768 o If neither SROM nor the environment contain a MAC address, an error
5771 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5772 will be programmed into hardware as part of the initialization process. This
5773 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5774 The naming convention is as follows:
5775 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5780 U-Boot is capable of booting (and performing other auxiliary operations on)
5781 images in two formats:
5783 New uImage format (FIT)
5784 -----------------------
5786 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5787 to Flattened Device Tree). It allows the use of images with multiple
5788 components (several kernels, ramdisks, etc.), with contents protected by
5789 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5795 Old image format is based on binary files which can be basically anything,
5796 preceded by a special header; see the definitions in include/image.h for
5797 details; basically, the header defines the following image properties:
5799 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5800 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5801 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5802 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5804 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5805 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5806 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5807 * Compression Type (uncompressed, gzip, bzip2)
5813 The header is marked by a special Magic Number, and both the header
5814 and the data portions of the image are secured against corruption by
5821 Although U-Boot should support any OS or standalone application
5822 easily, the main focus has always been on Linux during the design of
5825 U-Boot includes many features that so far have been part of some
5826 special "boot loader" code within the Linux kernel. Also, any
5827 "initrd" images to be used are no longer part of one big Linux image;
5828 instead, kernel and "initrd" are separate images. This implementation
5829 serves several purposes:
5831 - the same features can be used for other OS or standalone
5832 applications (for instance: using compressed images to reduce the
5833 Flash memory footprint)
5835 - it becomes much easier to port new Linux kernel versions because
5836 lots of low-level, hardware dependent stuff are done by U-Boot
5838 - the same Linux kernel image can now be used with different "initrd"
5839 images; of course this also means that different kernel images can
5840 be run with the same "initrd". This makes testing easier (you don't
5841 have to build a new "zImage.initrd" Linux image when you just
5842 change a file in your "initrd"). Also, a field-upgrade of the
5843 software is easier now.
5849 Porting Linux to U-Boot based systems:
5850 ---------------------------------------
5852 U-Boot cannot save you from doing all the necessary modifications to
5853 configure the Linux device drivers for use with your target hardware
5854 (no, we don't intend to provide a full virtual machine interface to
5857 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5859 Just make sure your machine specific header file (for instance
5860 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5861 Information structure as we define in include/asm-<arch>/u-boot.h,
5862 and make sure that your definition of IMAP_ADDR uses the same value
5863 as your U-Boot configuration in CONFIG_SYS_IMMR.
5865 Note that U-Boot now has a driver model, a unified model for drivers.
5866 If you are adding a new driver, plumb it into driver model. If there
5867 is no uclass available, you are encouraged to create one. See
5871 Configuring the Linux kernel:
5872 -----------------------------
5874 No specific requirements for U-Boot. Make sure you have some root
5875 device (initial ramdisk, NFS) for your target system.
5878 Building a Linux Image:
5879 -----------------------
5881 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5882 not used. If you use recent kernel source, a new build target
5883 "uImage" will exist which automatically builds an image usable by
5884 U-Boot. Most older kernels also have support for a "pImage" target,
5885 which was introduced for our predecessor project PPCBoot and uses a
5886 100% compatible format.
5890 make TQM850L_defconfig
5895 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5896 encapsulate a compressed Linux kernel image with header information,
5897 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5899 * build a standard "vmlinux" kernel image (in ELF binary format):
5901 * convert the kernel into a raw binary image:
5903 ${CROSS_COMPILE}-objcopy -O binary \
5904 -R .note -R .comment \
5905 -S vmlinux linux.bin
5907 * compress the binary image:
5911 * package compressed binary image for U-Boot:
5913 mkimage -A ppc -O linux -T kernel -C gzip \
5914 -a 0 -e 0 -n "Linux Kernel Image" \
5915 -d linux.bin.gz uImage
5918 The "mkimage" tool can also be used to create ramdisk images for use
5919 with U-Boot, either separated from the Linux kernel image, or
5920 combined into one file. "mkimage" encapsulates the images with a 64
5921 byte header containing information about target architecture,
5922 operating system, image type, compression method, entry points, time
5923 stamp, CRC32 checksums, etc.
5925 "mkimage" can be called in two ways: to verify existing images and
5926 print the header information, or to build new images.
5928 In the first form (with "-l" option) mkimage lists the information
5929 contained in the header of an existing U-Boot image; this includes
5930 checksum verification:
5932 tools/mkimage -l image
5933 -l ==> list image header information
5935 The second form (with "-d" option) is used to build a U-Boot image
5936 from a "data file" which is used as image payload:
5938 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5939 -n name -d data_file image
5940 -A ==> set architecture to 'arch'
5941 -O ==> set operating system to 'os'
5942 -T ==> set image type to 'type'
5943 -C ==> set compression type 'comp'
5944 -a ==> set load address to 'addr' (hex)
5945 -e ==> set entry point to 'ep' (hex)
5946 -n ==> set image name to 'name'
5947 -d ==> use image data from 'datafile'
5949 Right now, all Linux kernels for PowerPC systems use the same load
5950 address (0x00000000), but the entry point address depends on the
5953 - 2.2.x kernels have the entry point at 0x0000000C,
5954 - 2.3.x and later kernels have the entry point at 0x00000000.
5956 So a typical call to build a U-Boot image would read:
5958 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5959 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5960 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5961 > examples/uImage.TQM850L
5962 Image Name: 2.4.4 kernel for TQM850L
5963 Created: Wed Jul 19 02:34:59 2000
5964 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5965 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5966 Load Address: 0x00000000
5967 Entry Point: 0x00000000
5969 To verify the contents of the image (or check for corruption):
5971 -> tools/mkimage -l examples/uImage.TQM850L
5972 Image Name: 2.4.4 kernel for TQM850L
5973 Created: Wed Jul 19 02:34:59 2000
5974 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5975 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5976 Load Address: 0x00000000
5977 Entry Point: 0x00000000
5979 NOTE: for embedded systems where boot time is critical you can trade
5980 speed for memory and install an UNCOMPRESSED image instead: this
5981 needs more space in Flash, but boots much faster since it does not
5982 need to be uncompressed:
5984 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5985 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5986 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5987 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5988 > examples/uImage.TQM850L-uncompressed
5989 Image Name: 2.4.4 kernel for TQM850L
5990 Created: Wed Jul 19 02:34:59 2000
5991 Image Type: PowerPC Linux Kernel Image (uncompressed)
5992 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5993 Load Address: 0x00000000
5994 Entry Point: 0x00000000
5997 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5998 when your kernel is intended to use an initial ramdisk:
6000 -> tools/mkimage -n 'Simple Ramdisk Image' \
6001 > -A ppc -O linux -T ramdisk -C gzip \
6002 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
6003 Image Name: Simple Ramdisk Image
6004 Created: Wed Jan 12 14:01:50 2000
6005 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6006 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6007 Load Address: 0x00000000
6008 Entry Point: 0x00000000
6010 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6011 option performs the converse operation of the mkimage's second form (the "-d"
6012 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6015 tools/dumpimage -i image -T type -p position data_file
6016 -i ==> extract from the 'image' a specific 'data_file'
6017 -T ==> set image type to 'type'
6018 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6021 Installing a Linux Image:
6022 -------------------------
6024 To downloading a U-Boot image over the serial (console) interface,
6025 you must convert the image to S-Record format:
6027 objcopy -I binary -O srec examples/image examples/image.srec
6029 The 'objcopy' does not understand the information in the U-Boot
6030 image header, so the resulting S-Record file will be relative to
6031 address 0x00000000. To load it to a given address, you need to
6032 specify the target address as 'offset' parameter with the 'loads'
6035 Example: install the image to address 0x40100000 (which on the
6036 TQM8xxL is in the first Flash bank):
6038 => erase 40100000 401FFFFF
6044 ## Ready for S-Record download ...
6045 ~>examples/image.srec
6046 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6048 15989 15990 15991 15992
6049 [file transfer complete]
6051 ## Start Addr = 0x00000000
6054 You can check the success of the download using the 'iminfo' command;
6055 this includes a checksum verification so you can be sure no data
6056 corruption happened:
6060 ## Checking Image at 40100000 ...
6061 Image Name: 2.2.13 for initrd on TQM850L
6062 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6063 Data Size: 335725 Bytes = 327 kB = 0 MB
6064 Load Address: 00000000
6065 Entry Point: 0000000c
6066 Verifying Checksum ... OK
6072 The "bootm" command is used to boot an application that is stored in
6073 memory (RAM or Flash). In case of a Linux kernel image, the contents
6074 of the "bootargs" environment variable is passed to the kernel as
6075 parameters. You can check and modify this variable using the
6076 "printenv" and "setenv" commands:
6079 => printenv bootargs
6080 bootargs=root=/dev/ram
6082 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6084 => printenv bootargs
6085 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6088 ## Booting Linux kernel at 40020000 ...
6089 Image Name: 2.2.13 for NFS on TQM850L
6090 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6091 Data Size: 381681 Bytes = 372 kB = 0 MB
6092 Load Address: 00000000
6093 Entry Point: 0000000c
6094 Verifying Checksum ... OK
6095 Uncompressing Kernel Image ... OK
6096 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
6097 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6098 time_init: decrementer frequency = 187500000/60
6099 Calibrating delay loop... 49.77 BogoMIPS
6100 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6103 If you want to boot a Linux kernel with initial RAM disk, you pass
6104 the memory addresses of both the kernel and the initrd image (PPBCOOT
6105 format!) to the "bootm" command:
6107 => imi 40100000 40200000
6109 ## Checking Image at 40100000 ...
6110 Image Name: 2.2.13 for initrd on TQM850L
6111 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6112 Data Size: 335725 Bytes = 327 kB = 0 MB
6113 Load Address: 00000000
6114 Entry Point: 0000000c
6115 Verifying Checksum ... OK
6117 ## Checking Image at 40200000 ...
6118 Image Name: Simple Ramdisk Image
6119 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6120 Data Size: 566530 Bytes = 553 kB = 0 MB
6121 Load Address: 00000000
6122 Entry Point: 00000000
6123 Verifying Checksum ... OK
6125 => bootm 40100000 40200000
6126 ## Booting Linux kernel at 40100000 ...
6127 Image Name: 2.2.13 for initrd on TQM850L
6128 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6129 Data Size: 335725 Bytes = 327 kB = 0 MB
6130 Load Address: 00000000
6131 Entry Point: 0000000c
6132 Verifying Checksum ... OK
6133 Uncompressing Kernel Image ... OK
6134 ## Loading RAMDisk Image at 40200000 ...
6135 Image Name: Simple Ramdisk Image
6136 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6137 Data Size: 566530 Bytes = 553 kB = 0 MB
6138 Load Address: 00000000
6139 Entry Point: 00000000
6140 Verifying Checksum ... OK
6141 Loading Ramdisk ... OK
6142 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
6143 Boot arguments: root=/dev/ram
6144 time_init: decrementer frequency = 187500000/60
6145 Calibrating delay loop... 49.77 BogoMIPS
6147 RAMDISK: Compressed image found at block 0
6148 VFS: Mounted root (ext2 filesystem).
6152 Boot Linux and pass a flat device tree:
6155 First, U-Boot must be compiled with the appropriate defines. See the section
6156 titled "Linux Kernel Interface" above for a more in depth explanation. The
6157 following is an example of how to start a kernel and pass an updated
6163 oft=oftrees/mpc8540ads.dtb
6164 => tftp $oftaddr $oft
6165 Speed: 1000, full duplex
6167 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6168 Filename 'oftrees/mpc8540ads.dtb'.
6169 Load address: 0x300000
6172 Bytes transferred = 4106 (100a hex)
6173 => tftp $loadaddr $bootfile
6174 Speed: 1000, full duplex
6176 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6178 Load address: 0x200000
6179 Loading:############
6181 Bytes transferred = 1029407 (fb51f hex)
6186 => bootm $loadaddr - $oftaddr
6187 ## Booting image at 00200000 ...
6188 Image Name: Linux-2.6.17-dirty
6189 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6190 Data Size: 1029343 Bytes = 1005.2 kB
6191 Load Address: 00000000
6192 Entry Point: 00000000
6193 Verifying Checksum ... OK
6194 Uncompressing Kernel Image ... OK
6195 Booting using flat device tree at 0x300000
6196 Using MPC85xx ADS machine description
6197 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6201 More About U-Boot Image Types:
6202 ------------------------------
6204 U-Boot supports the following image types:
6206 "Standalone Programs" are directly runnable in the environment
6207 provided by U-Boot; it is expected that (if they behave
6208 well) you can continue to work in U-Boot after return from
6209 the Standalone Program.
6210 "OS Kernel Images" are usually images of some Embedded OS which
6211 will take over control completely. Usually these programs
6212 will install their own set of exception handlers, device
6213 drivers, set up the MMU, etc. - this means, that you cannot
6214 expect to re-enter U-Boot except by resetting the CPU.
6215 "RAMDisk Images" are more or less just data blocks, and their
6216 parameters (address, size) are passed to an OS kernel that is
6218 "Multi-File Images" contain several images, typically an OS
6219 (Linux) kernel image and one or more data images like
6220 RAMDisks. This construct is useful for instance when you want
6221 to boot over the network using BOOTP etc., where the boot
6222 server provides just a single image file, but you want to get
6223 for instance an OS kernel and a RAMDisk image.
6225 "Multi-File Images" start with a list of image sizes, each
6226 image size (in bytes) specified by an "uint32_t" in network
6227 byte order. This list is terminated by an "(uint32_t)0".
6228 Immediately after the terminating 0 follow the images, one by
6229 one, all aligned on "uint32_t" boundaries (size rounded up to
6230 a multiple of 4 bytes).
6232 "Firmware Images" are binary images containing firmware (like
6233 U-Boot or FPGA images) which usually will be programmed to
6236 "Script files" are command sequences that will be executed by
6237 U-Boot's command interpreter; this feature is especially
6238 useful when you configure U-Boot to use a real shell (hush)
6239 as command interpreter.
6241 Booting the Linux zImage:
6242 -------------------------
6244 On some platforms, it's possible to boot Linux zImage. This is done
6245 using the "bootz" command. The syntax of "bootz" command is the same
6246 as the syntax of "bootm" command.
6248 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6249 kernel with raw initrd images. The syntax is slightly different, the
6250 address of the initrd must be augmented by it's size, in the following
6251 format: "<initrd addres>:<initrd size>".
6257 One of the features of U-Boot is that you can dynamically load and
6258 run "standalone" applications, which can use some resources of
6259 U-Boot like console I/O functions or interrupt services.
6261 Two simple examples are included with the sources:
6266 'examples/hello_world.c' contains a small "Hello World" Demo
6267 application; it is automatically compiled when you build U-Boot.
6268 It's configured to run at address 0x00040004, so you can play with it
6272 ## Ready for S-Record download ...
6273 ~>examples/hello_world.srec
6274 1 2 3 4 5 6 7 8 9 10 11 ...
6275 [file transfer complete]
6277 ## Start Addr = 0x00040004
6279 => go 40004 Hello World! This is a test.
6280 ## Starting application at 0x00040004 ...
6291 Hit any key to exit ...
6293 ## Application terminated, rc = 0x0
6295 Another example, which demonstrates how to register a CPM interrupt
6296 handler with the U-Boot code, can be found in 'examples/timer.c'.
6297 Here, a CPM timer is set up to generate an interrupt every second.
6298 The interrupt service routine is trivial, just printing a '.'
6299 character, but this is just a demo program. The application can be
6300 controlled by the following keys:
6302 ? - print current values og the CPM Timer registers
6303 b - enable interrupts and start timer
6304 e - stop timer and disable interrupts
6305 q - quit application
6308 ## Ready for S-Record download ...
6309 ~>examples/timer.srec
6310 1 2 3 4 5 6 7 8 9 10 11 ...
6311 [file transfer complete]
6313 ## Start Addr = 0x00040004
6316 ## Starting application at 0x00040004 ...
6319 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6322 [q, b, e, ?] Set interval 1000000 us
6325 [q, b, e, ?] ........
6326 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6329 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6332 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6335 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6337 [q, b, e, ?] ...Stopping timer
6339 [q, b, e, ?] ## Application terminated, rc = 0x0
6345 Over time, many people have reported problems when trying to use the
6346 "minicom" terminal emulation program for serial download. I (wd)
6347 consider minicom to be broken, and recommend not to use it. Under
6348 Unix, I recommend to use C-Kermit for general purpose use (and
6349 especially for kermit binary protocol download ("loadb" command), and
6350 use "cu" for S-Record download ("loads" command). See
6351 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6352 for help with kermit.
6355 Nevertheless, if you absolutely want to use it try adding this
6356 configuration to your "File transfer protocols" section:
6358 Name Program Name U/D FullScr IO-Red. Multi
6359 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6360 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6366 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6367 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6369 Building requires a cross environment; it is known to work on
6370 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6371 need gmake since the Makefiles are not compatible with BSD make).
6372 Note that the cross-powerpc package does not install include files;
6373 attempting to build U-Boot will fail because <machine/ansi.h> is
6374 missing. This file has to be installed and patched manually:
6376 # cd /usr/pkg/cross/powerpc-netbsd/include
6378 # ln -s powerpc machine
6379 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6380 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6382 Native builds *don't* work due to incompatibilities between native
6383 and U-Boot include files.
6385 Booting assumes that (the first part of) the image booted is a
6386 stage-2 loader which in turn loads and then invokes the kernel
6387 proper. Loader sources will eventually appear in the NetBSD source
6388 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6389 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6392 Implementation Internals:
6393 =========================
6395 The following is not intended to be a complete description of every
6396 implementation detail. However, it should help to understand the
6397 inner workings of U-Boot and make it easier to port it to custom
6401 Initial Stack, Global Data:
6402 ---------------------------
6404 The implementation of U-Boot is complicated by the fact that U-Boot
6405 starts running out of ROM (flash memory), usually without access to
6406 system RAM (because the memory controller is not initialized yet).
6407 This means that we don't have writable Data or BSS segments, and BSS
6408 is not initialized as zero. To be able to get a C environment working
6409 at all, we have to allocate at least a minimal stack. Implementation
6410 options for this are defined and restricted by the CPU used: Some CPU
6411 models provide on-chip memory (like the IMMR area on MPC8xx and
6412 MPC826x processors), on others (parts of) the data cache can be
6413 locked as (mis-) used as memory, etc.
6415 Chris Hallinan posted a good summary of these issues to the
6416 U-Boot mailing list:
6418 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6419 From: "Chris Hallinan" <clh@net1plus.com>
6420 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6423 Correct me if I'm wrong, folks, but the way I understand it
6424 is this: Using DCACHE as initial RAM for Stack, etc, does not
6425 require any physical RAM backing up the cache. The cleverness
6426 is that the cache is being used as a temporary supply of
6427 necessary storage before the SDRAM controller is setup. It's
6428 beyond the scope of this list to explain the details, but you
6429 can see how this works by studying the cache architecture and
6430 operation in the architecture and processor-specific manuals.
6432 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6433 is another option for the system designer to use as an
6434 initial stack/RAM area prior to SDRAM being available. Either
6435 option should work for you. Using CS 4 should be fine if your
6436 board designers haven't used it for something that would
6437 cause you grief during the initial boot! It is frequently not
6440 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6441 with your processor/board/system design. The default value
6442 you will find in any recent u-boot distribution in
6443 walnut.h should work for you. I'd set it to a value larger
6444 than your SDRAM module. If you have a 64MB SDRAM module, set
6445 it above 400_0000. Just make sure your board has no resources
6446 that are supposed to respond to that address! That code in
6447 start.S has been around a while and should work as is when
6448 you get the config right.
6453 It is essential to remember this, since it has some impact on the C
6454 code for the initialization procedures:
6456 * Initialized global data (data segment) is read-only. Do not attempt
6459 * Do not use any uninitialized global data (or implicitly initialized
6460 as zero data - BSS segment) at all - this is undefined, initiali-
6461 zation is performed later (when relocating to RAM).
6463 * Stack space is very limited. Avoid big data buffers or things like
6466 Having only the stack as writable memory limits means we cannot use
6467 normal global data to share information between the code. But it
6468 turned out that the implementation of U-Boot can be greatly
6469 simplified by making a global data structure (gd_t) available to all
6470 functions. We could pass a pointer to this data as argument to _all_
6471 functions, but this would bloat the code. Instead we use a feature of
6472 the GCC compiler (Global Register Variables) to share the data: we
6473 place a pointer (gd) to the global data into a register which we
6474 reserve for this purpose.
6476 When choosing a register for such a purpose we are restricted by the
6477 relevant (E)ABI specifications for the current architecture, and by
6478 GCC's implementation.
6480 For PowerPC, the following registers have specific use:
6482 R2: reserved for system use
6483 R3-R4: parameter passing and return values
6484 R5-R10: parameter passing
6485 R13: small data area pointer
6489 (U-Boot also uses R12 as internal GOT pointer. r12
6490 is a volatile register so r12 needs to be reset when
6491 going back and forth between asm and C)
6493 ==> U-Boot will use R2 to hold a pointer to the global data
6495 Note: on PPC, we could use a static initializer (since the
6496 address of the global data structure is known at compile time),
6497 but it turned out that reserving a register results in somewhat
6498 smaller code - although the code savings are not that big (on
6499 average for all boards 752 bytes for the whole U-Boot image,
6500 624 text + 127 data).
6502 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6503 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6505 ==> U-Boot will use P3 to hold a pointer to the global data
6507 On ARM, the following registers are used:
6509 R0: function argument word/integer result
6510 R1-R3: function argument word
6511 R9: platform specific
6512 R10: stack limit (used only if stack checking is enabled)
6513 R11: argument (frame) pointer
6514 R12: temporary workspace
6517 R15: program counter
6519 ==> U-Boot will use R9 to hold a pointer to the global data
6521 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6523 On Nios II, the ABI is documented here:
6524 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6526 ==> U-Boot will use gp to hold a pointer to the global data
6528 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6529 to access small data sections, so gp is free.
6531 On NDS32, the following registers are used:
6533 R0-R1: argument/return
6535 R15: temporary register for assembler
6536 R16: trampoline register
6537 R28: frame pointer (FP)
6538 R29: global pointer (GP)
6539 R30: link register (LP)
6540 R31: stack pointer (SP)
6541 PC: program counter (PC)
6543 ==> U-Boot will use R10 to hold a pointer to the global data
6545 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6546 or current versions of GCC may "optimize" the code too much.
6551 U-Boot runs in system state and uses physical addresses, i.e. the
6552 MMU is not used either for address mapping nor for memory protection.
6554 The available memory is mapped to fixed addresses using the memory
6555 controller. In this process, a contiguous block is formed for each
6556 memory type (Flash, SDRAM, SRAM), even when it consists of several
6557 physical memory banks.
6559 U-Boot is installed in the first 128 kB of the first Flash bank (on
6560 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6561 booting and sizing and initializing DRAM, the code relocates itself
6562 to the upper end of DRAM. Immediately below the U-Boot code some
6563 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6564 configuration setting]. Below that, a structure with global Board
6565 Info data is placed, followed by the stack (growing downward).
6567 Additionally, some exception handler code is copied to the low 8 kB
6568 of DRAM (0x00000000 ... 0x00001FFF).
6570 So a typical memory configuration with 16 MB of DRAM could look like
6573 0x0000 0000 Exception Vector code
6576 0x0000 2000 Free for Application Use
6582 0x00FB FF20 Monitor Stack (Growing downward)
6583 0x00FB FFAC Board Info Data and permanent copy of global data
6584 0x00FC 0000 Malloc Arena
6587 0x00FE 0000 RAM Copy of Monitor Code
6588 ... eventually: LCD or video framebuffer
6589 ... eventually: pRAM (Protected RAM - unchanged by reset)
6590 0x00FF FFFF [End of RAM]
6593 System Initialization:
6594 ----------------------
6596 In the reset configuration, U-Boot starts at the reset entry point
6597 (on most PowerPC systems at address 0x00000100). Because of the reset
6598 configuration for CS0# this is a mirror of the on board Flash memory.
6599 To be able to re-map memory U-Boot then jumps to its link address.
6600 To be able to implement the initialization code in C, a (small!)
6601 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6602 which provide such a feature like MPC8xx or MPC8260), or in a locked
6603 part of the data cache. After that, U-Boot initializes the CPU core,
6604 the caches and the SIU.
6606 Next, all (potentially) available memory banks are mapped using a
6607 preliminary mapping. For example, we put them on 512 MB boundaries
6608 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6609 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6610 programmed for SDRAM access. Using the temporary configuration, a
6611 simple memory test is run that determines the size of the SDRAM
6614 When there is more than one SDRAM bank, and the banks are of
6615 different size, the largest is mapped first. For equal size, the first
6616 bank (CS2#) is mapped first. The first mapping is always for address
6617 0x00000000, with any additional banks following immediately to create
6618 contiguous memory starting from 0.
6620 Then, the monitor installs itself at the upper end of the SDRAM area
6621 and allocates memory for use by malloc() and for the global Board
6622 Info data; also, the exception vector code is copied to the low RAM
6623 pages, and the final stack is set up.
6625 Only after this relocation will you have a "normal" C environment;
6626 until that you are restricted in several ways, mostly because you are
6627 running from ROM, and because the code will have to be relocated to a
6631 U-Boot Porting Guide:
6632 ----------------------
6634 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6638 int main(int argc, char *argv[])
6640 sighandler_t no_more_time;
6642 signal(SIGALRM, no_more_time);
6643 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6645 if (available_money > available_manpower) {
6646 Pay consultant to port U-Boot;
6650 Download latest U-Boot source;
6652 Subscribe to u-boot mailing list;
6655 email("Hi, I am new to U-Boot, how do I get started?");
6658 Read the README file in the top level directory;
6659 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6660 Read applicable doc/*.README;
6661 Read the source, Luke;
6662 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6665 if (available_money > toLocalCurrency ($2500))
6668 Add a lot of aggravation and time;
6670 if (a similar board exists) { /* hopefully... */
6671 cp -a board/<similar> board/<myboard>
6672 cp include/configs/<similar>.h include/configs/<myboard>.h
6674 Create your own board support subdirectory;
6675 Create your own board include/configs/<myboard>.h file;
6677 Edit new board/<myboard> files
6678 Edit new include/configs/<myboard>.h
6683 Add / modify source code;
6687 email("Hi, I am having problems...");
6689 Send patch file to the U-Boot email list;
6690 if (reasonable critiques)
6691 Incorporate improvements from email list code review;
6693 Defend code as written;
6699 void no_more_time (int sig)
6708 All contributions to U-Boot should conform to the Linux kernel
6709 coding style; see the file "Documentation/CodingStyle" and the script
6710 "scripts/Lindent" in your Linux kernel source directory.
6712 Source files originating from a different project (for example the
6713 MTD subsystem) are generally exempt from these guidelines and are not
6714 reformatted to ease subsequent migration to newer versions of those
6717 Please note that U-Boot is implemented in C (and to some small parts in
6718 Assembler); no C++ is used, so please do not use C++ style comments (//)
6721 Please also stick to the following formatting rules:
6722 - remove any trailing white space
6723 - use TAB characters for indentation and vertical alignment, not spaces
6724 - make sure NOT to use DOS '\r\n' line feeds
6725 - do not add more than 2 consecutive empty lines to source files
6726 - do not add trailing empty lines to source files
6728 Submissions which do not conform to the standards may be returned
6729 with a request to reformat the changes.
6735 Since the number of patches for U-Boot is growing, we need to
6736 establish some rules. Submissions which do not conform to these rules
6737 may be rejected, even when they contain important and valuable stuff.
6739 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6741 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6742 see http://lists.denx.de/mailman/listinfo/u-boot
6744 When you send a patch, please include the following information with
6747 * For bug fixes: a description of the bug and how your patch fixes
6748 this bug. Please try to include a way of demonstrating that the
6749 patch actually fixes something.
6751 * For new features: a description of the feature and your
6754 * A CHANGELOG entry as plaintext (separate from the patch)
6756 * For major contributions, your entry to the CREDITS file
6758 * When you add support for a new board, don't forget to add a
6759 maintainer e-mail address to the boards.cfg file, too.
6761 * If your patch adds new configuration options, don't forget to
6762 document these in the README file.
6764 * The patch itself. If you are using git (which is *strongly*
6765 recommended) you can easily generate the patch using the
6766 "git format-patch". If you then use "git send-email" to send it to
6767 the U-Boot mailing list, you will avoid most of the common problems
6768 with some other mail clients.
6770 If you cannot use git, use "diff -purN OLD NEW". If your version of
6771 diff does not support these options, then get the latest version of
6774 The current directory when running this command shall be the parent
6775 directory of the U-Boot source tree (i. e. please make sure that
6776 your patch includes sufficient directory information for the
6779 We prefer patches as plain text. MIME attachments are discouraged,
6780 and compressed attachments must not be used.
6782 * If one logical set of modifications affects or creates several
6783 files, all these changes shall be submitted in a SINGLE patch file.
6785 * Changesets that contain different, unrelated modifications shall be
6786 submitted as SEPARATE patches, one patch per changeset.
6791 * Before sending the patch, run the MAKEALL script on your patched
6792 source tree and make sure that no errors or warnings are reported
6793 for any of the boards.
6795 * Keep your modifications to the necessary minimum: A patch
6796 containing several unrelated changes or arbitrary reformats will be
6797 returned with a request to re-formatting / split it.
6799 * If you modify existing code, make sure that your new code does not
6800 add to the memory footprint of the code ;-) Small is beautiful!
6801 When adding new features, these should compile conditionally only
6802 (using #ifdef), and the resulting code with the new feature
6803 disabled must not need more memory than the old code without your
6806 * Remember that there is a size limit of 100 kB per message on the
6807 u-boot mailing list. Bigger patches will be moderated. If they are
6808 reasonable and not too big, they will be acknowledged. But patches
6809 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob