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 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_config".
257 Example: For a TQM823L module type:
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_config". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Board flavour: (if CONFIG_MPC8260ADS is defined)
327 CONFIG_SYS_8260ADS - original MPC8260ADS
328 CONFIG_SYS_8266ADS - MPC8266ADS
329 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
330 CONFIG_SYS_8272ADS - MPC8272ADS
332 - Marvell Family Member
333 CONFIG_SYS_MVFS - define it if you want to enable
334 multiple fs option at one time
335 for marvell soc family
337 - MPC824X Family Member (if CONFIG_MPC824X is defined)
338 Define exactly one of
339 CONFIG_MPC8240, CONFIG_MPC8245
341 - 8xx CPU Options: (if using an MPC8xx CPU)
342 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
343 get_gclk_freq() cannot work
344 e.g. if there is no 32KHz
345 reference PIT/RTC clock
346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
349 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
350 CONFIG_SYS_8xx_CPUCLK_MIN
351 CONFIG_SYS_8xx_CPUCLK_MAX
352 CONFIG_8xx_CPUCLK_DEFAULT
353 See doc/README.MPC866
355 CONFIG_SYS_MEASURE_CPUCLK
357 Define this to measure the actual CPU clock instead
358 of relying on the correctness of the configured
359 values. Mostly useful for board bringup to make sure
360 the PLL is locked at the intended frequency. Note
361 that this requires a (stable) reference clock (32 kHz
362 RTC clock or CONFIG_SYS_8XX_XIN)
364 CONFIG_SYS_DELAYED_ICACHE
366 Define this option if you want to enable the
367 ICache only when Code runs from RAM.
372 Specifies that the core is a 64-bit PowerPC implementation (implements
373 the "64" category of the Power ISA). This is necessary for ePAPR
374 compliance, among other possible reasons.
376 CONFIG_SYS_FSL_TBCLK_DIV
378 Defines the core time base clock divider ratio compared to the
379 system clock. On most PQ3 devices this is 8, on newer QorIQ
380 devices it can be 16 or 32. The ratio varies from SoC to Soc.
382 CONFIG_SYS_FSL_PCIE_COMPAT
384 Defines the string to utilize when trying to match PCIe device
385 tree nodes for the given platform.
387 CONFIG_SYS_PPC_E500_DEBUG_TLB
389 Enables a temporary TLB entry to be used during boot to work
390 around limitations in e500v1 and e500v2 external debugger
391 support. This reduces the portions of the boot code where
392 breakpoints and single stepping do not work. The value of this
393 symbol should be set to the TLB1 entry to be used for this
396 CONFIG_SYS_FSL_ERRATUM_A004510
398 Enables a workaround for erratum A004510. If set,
399 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
400 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
402 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
405 Defines one or two SoC revisions (low 8 bits of SVR)
406 for which the A004510 workaround should be applied.
408 The rest of SVR is either not relevant to the decision
409 of whether the erratum is present (e.g. p2040 versus
410 p2041) or is implied by the build target, which controls
411 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
413 See Freescale App Note 4493 for more information about
416 CONFIG_A003399_NOR_WORKAROUND
417 Enables a workaround for IFC erratum A003399. It is only
418 requred during NOR boot.
420 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
422 This is the value to write into CCSR offset 0x18600
423 according to the A004510 workaround.
425 CONFIG_SYS_FSL_DSP_DDR_ADDR
426 This value denotes start offset of DDR memory which is
427 connected exclusively to the DSP cores.
429 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
430 This value denotes start offset of M2 memory
431 which is directly connected to the DSP core.
433 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
434 This value denotes start offset of M3 memory which is directly
435 connected to the DSP core.
437 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
438 This value denotes start offset of DSP CCSR space.
440 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
441 Single Source Clock is clocking mode present in some of FSL SoC's.
442 In this mode, a single differential clock is used to supply
443 clocks to the sysclock, ddrclock and usbclock.
445 CONFIG_SYS_CPC_REINIT_F
446 This CONFIG is defined when the CPC is configured as SRAM at the
447 time of U-boot entry and is required to be re-initialized.
450 Inidcates this SoC supports deep sleep feature. If deep sleep is
451 supported, core will start to execute uboot when wakes up.
453 - Generic CPU options:
454 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
456 Defines the endianess of the CPU. Implementation of those
457 values is arch specific.
460 Freescale DDR driver in use. This type of DDR controller is
461 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
464 CONFIG_SYS_FSL_DDR_ADDR
465 Freescale DDR memory-mapped register base.
467 CONFIG_SYS_FSL_DDR_EMU
468 Specify emulator support for DDR. Some DDR features such as
469 deskew training are not available.
471 CONFIG_SYS_FSL_DDRC_GEN1
472 Freescale DDR1 controller.
474 CONFIG_SYS_FSL_DDRC_GEN2
475 Freescale DDR2 controller.
477 CONFIG_SYS_FSL_DDRC_GEN3
478 Freescale DDR3 controller.
480 CONFIG_SYS_FSL_DDRC_GEN4
481 Freescale DDR4 controller.
483 CONFIG_SYS_FSL_DDRC_ARM_GEN3
484 Freescale DDR3 controller for ARM-based SoCs.
487 Board config to use DDR1. It can be enabled for SoCs with
488 Freescale DDR1 or DDR2 controllers, depending on the board
492 Board config to use DDR2. It can be eanbeld for SoCs with
493 Freescale DDR2 or DDR3 controllers, depending on the board
497 Board config to use DDR3. It can be enabled for SoCs with
498 Freescale DDR3 or DDR3L controllers.
501 Board config to use DDR3L. It can be enabled for SoCs with
505 Board config to use DDR4. It can be enabled for SoCs with
508 CONFIG_SYS_FSL_IFC_BE
509 Defines the IFC controller register space as Big Endian
511 CONFIG_SYS_FSL_IFC_LE
512 Defines the IFC controller register space as Little Endian
514 CONFIG_SYS_FSL_PBL_PBI
515 It enables addition of RCW (Power on reset configuration) in built image.
516 Please refer doc/README.pblimage for more details
518 CONFIG_SYS_FSL_PBL_RCW
519 It adds PBI(pre-boot instructions) commands in u-boot build image.
520 PBI commands can be used to configure SoC before it starts the execution.
521 Please refer doc/README.pblimage for more details
524 It adds a target to create boot binary having SPL binary in PBI format
525 concatenated with u-boot binary.
527 CONFIG_SYS_FSL_DDR_BE
528 Defines the DDR controller register space as Big Endian
530 CONFIG_SYS_FSL_DDR_LE
531 Defines the DDR controller register space as Little Endian
533 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
534 Physical address from the view of DDR controllers. It is the
535 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
536 it could be different for ARM SoCs.
538 CONFIG_SYS_FSL_DDR_INTLV_256B
539 DDR controller interleaving on 256-byte. This is a special
540 interleaving mode, handled by Dickens for Freescale layerscape
543 - Intel Monahans options:
544 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
546 Defines the Monahans run mode to oscillator
547 ratio. Valid values are 8, 16, 24, 31. The core
548 frequency is this value multiplied by 13 MHz.
550 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
552 Defines the Monahans turbo mode to oscillator
553 ratio. Valid values are 1 (default if undefined) and
554 2. The core frequency as calculated above is multiplied
558 CONFIG_SYS_INIT_SP_OFFSET
560 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
561 pointer. This is needed for the temporary stack before
564 CONFIG_SYS_MIPS_CACHE_MODE
566 Cache operation mode for the MIPS CPU.
567 See also arch/mips/include/asm/mipsregs.h.
569 CONF_CM_CACHABLE_NO_WA
572 CONF_CM_CACHABLE_NONCOHERENT
576 CONF_CM_CACHABLE_ACCELERATED
578 CONFIG_SYS_XWAY_EBU_BOOTCFG
580 Special option for Lantiq XWAY SoCs for booting from NOR flash.
581 See also arch/mips/cpu/mips32/start.S.
583 CONFIG_XWAY_SWAP_BYTES
585 Enable compilation of tools/xway-swap-bytes needed for Lantiq
586 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
587 be swapped if a flash programmer is used.
590 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
592 Select high exception vectors of the ARM core, e.g., do not
593 clear the V bit of the c1 register of CP15.
595 CONFIG_SYS_THUMB_BUILD
597 Use this flag to build U-Boot using the Thumb instruction
598 set for ARM architectures. Thumb instruction set provides
599 better code density. For ARM architectures that support
600 Thumb2 this flag will result in Thumb2 code generated by
603 CONFIG_ARM_ERRATA_716044
604 CONFIG_ARM_ERRATA_742230
605 CONFIG_ARM_ERRATA_743622
606 CONFIG_ARM_ERRATA_751472
607 CONFIG_ARM_ERRATA_794072
608 CONFIG_ARM_ERRATA_761320
610 If set, the workarounds for these ARM errata are applied early
611 during U-Boot startup. Note that these options force the
612 workarounds to be applied; no CPU-type/version detection
613 exists, unlike the similar options in the Linux kernel. Do not
614 set these options unless they apply!
619 The frequency of the timer returned by get_timer().
620 get_timer() must operate in milliseconds and this CONFIG
621 option must be set to 1000.
623 - Linux Kernel Interface:
626 U-Boot stores all clock information in Hz
627 internally. For binary compatibility with older Linux
628 kernels (which expect the clocks passed in the
629 bd_info data to be in MHz) the environment variable
630 "clocks_in_mhz" can be defined so that U-Boot
631 converts clock data to MHZ before passing it to the
633 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
634 "clocks_in_mhz=1" is automatically included in the
637 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
639 When transferring memsize parameter to linux, some versions
640 expect it to be in bytes, others in MB.
641 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
645 New kernel versions are expecting firmware settings to be
646 passed using flattened device trees (based on open firmware
650 * New libfdt-based support
651 * Adds the "fdt" command
652 * The bootm command automatically updates the fdt
654 OF_CPU - The proper name of the cpus node (only required for
655 MPC512X and MPC5xxx based boards).
656 OF_SOC - The proper name of the soc node (only required for
657 MPC512X and MPC5xxx based boards).
658 OF_TBCLK - The timebase frequency.
659 OF_STDOUT_PATH - The path to the console device
661 boards with QUICC Engines require OF_QE to set UCC MAC
664 CONFIG_OF_BOARD_SETUP
666 Board code has addition modification that it wants to make
667 to the flat device tree before handing it off to the kernel
671 This define fills in the correct boot CPU in the boot
672 param header, the default value is zero if undefined.
676 U-Boot can detect if an IDE device is present or not.
677 If not, and this new config option is activated, U-Boot
678 removes the ATA node from the DTS before booting Linux,
679 so the Linux IDE driver does not probe the device and
680 crash. This is needed for buggy hardware (uc101) where
681 no pull down resistor is connected to the signal IDE5V_DD7.
683 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
685 This setting is mandatory for all boards that have only one
686 machine type and must be used to specify the machine type
687 number as it appears in the ARM machine registry
688 (see http://www.arm.linux.org.uk/developer/machines/).
689 Only boards that have multiple machine types supported
690 in a single configuration file and the machine type is
691 runtime discoverable, do not have to use this setting.
693 - vxWorks boot parameters:
695 bootvx constructs a valid bootline using the following
696 environments variables: bootfile, ipaddr, serverip, hostname.
697 It loads the vxWorks image pointed bootfile.
699 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
700 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
701 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
702 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
704 CONFIG_SYS_VXWORKS_ADD_PARAMS
706 Add it at the end of the bootline. E.g "u=username pw=secret"
708 Note: If a "bootargs" environment is defined, it will overwride
709 the defaults discussed just above.
711 - Cache Configuration:
712 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
713 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
714 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
716 - Cache Configuration for ARM:
717 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
719 CONFIG_SYS_PL310_BASE - Physical base address of PL310
720 controller register space
725 Define this if you want support for Amba PrimeCell PL010 UARTs.
729 Define this if you want support for Amba PrimeCell PL011 UARTs.
733 If you have Amba PrimeCell PL011 UARTs, set this variable to
734 the clock speed of the UARTs.
738 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
739 define this to a list of base addresses for each (supported)
740 port. See e.g. include/configs/versatile.h
742 CONFIG_PL011_SERIAL_RLCR
744 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
745 have separate receive and transmit line control registers. Set
746 this variable to initialize the extra register.
748 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
750 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
751 boot loader that has already initialized the UART. Define this
752 variable to flush the UART at init time.
754 CONFIG_SERIAL_HW_FLOW_CONTROL
756 Define this variable to enable hw flow control in serial driver.
757 Current user of this option is drivers/serial/nsl16550.c driver
760 Depending on board, define exactly one serial port
761 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
762 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
763 console by defining CONFIG_8xx_CONS_NONE
765 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
766 port routines must be defined elsewhere
767 (i.e. serial_init(), serial_getc(), ...)
770 Enables console device for a color framebuffer. Needs following
771 defines (cf. smiLynxEM, i8042)
772 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
774 VIDEO_HW_RECTFILL graphic chip supports
777 VIDEO_HW_BITBLT graphic chip supports
778 bit-blit (cf. smiLynxEM)
779 VIDEO_VISIBLE_COLS visible pixel columns
781 VIDEO_VISIBLE_ROWS visible pixel rows
782 VIDEO_PIXEL_SIZE bytes per pixel
783 VIDEO_DATA_FORMAT graphic data format
784 (0-5, cf. cfb_console.c)
785 VIDEO_FB_ADRS framebuffer address
786 VIDEO_KBD_INIT_FCT keyboard int fct
787 (i.e. i8042_kbd_init())
788 VIDEO_TSTC_FCT test char fct
790 VIDEO_GETC_FCT get char fct
792 CONFIG_CONSOLE_CURSOR cursor drawing on/off
793 (requires blink timer
795 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
796 CONFIG_CONSOLE_TIME display time/date info in
798 (requires CONFIG_CMD_DATE)
799 CONFIG_VIDEO_LOGO display Linux logo in
801 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
802 linux_logo.h for logo.
803 Requires CONFIG_VIDEO_LOGO
804 CONFIG_CONSOLE_EXTRA_INFO
805 additional board info beside
808 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
809 a limited number of ANSI escape sequences (cursor control,
810 erase functions and limited graphics rendition control).
812 When CONFIG_CFB_CONSOLE is defined, video console is
813 default i/o. Serial console can be forced with
814 environment 'console=serial'.
816 When CONFIG_SILENT_CONSOLE is defined, all console
817 messages (by U-Boot and Linux!) can be silenced with
818 the "silent" environment variable. See
819 doc/README.silent for more information.
821 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
823 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
827 CONFIG_BAUDRATE - in bps
828 Select one of the baudrates listed in
829 CONFIG_SYS_BAUDRATE_TABLE, see below.
830 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
832 - Console Rx buffer length
833 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
834 the maximum receive buffer length for the SMC.
835 This option is actual only for 82xx and 8xx possible.
836 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
837 must be defined, to setup the maximum idle timeout for
840 - Pre-Console Buffer:
841 Prior to the console being initialised (i.e. serial UART
842 initialised etc) all console output is silently discarded.
843 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
844 buffer any console messages prior to the console being
845 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
846 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
847 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
848 bytes are output before the console is initialised, the
849 earlier bytes are discarded.
851 'Sane' compilers will generate smaller code if
852 CONFIG_PRE_CON_BUF_SZ is a power of 2
854 - Safe printf() functions
855 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
856 the printf() functions. These are defined in
857 include/vsprintf.h and include snprintf(), vsnprintf() and
858 so on. Code size increase is approximately 300-500 bytes.
859 If this option is not given then these functions will
860 silently discard their buffer size argument - this means
861 you are not getting any overflow checking in this case.
863 - Boot Delay: CONFIG_BOOTDELAY - in seconds
864 Delay before automatically booting the default image;
865 set to -1 to disable autoboot.
866 set to -2 to autoboot with no delay and not check for abort
867 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
869 See doc/README.autoboot for these options that
870 work with CONFIG_BOOTDELAY. None are required.
871 CONFIG_BOOT_RETRY_TIME
872 CONFIG_BOOT_RETRY_MIN
873 CONFIG_AUTOBOOT_KEYED
874 CONFIG_AUTOBOOT_PROMPT
875 CONFIG_AUTOBOOT_DELAY_STR
876 CONFIG_AUTOBOOT_STOP_STR
877 CONFIG_AUTOBOOT_DELAY_STR2
878 CONFIG_AUTOBOOT_STOP_STR2
879 CONFIG_ZERO_BOOTDELAY_CHECK
880 CONFIG_RESET_TO_RETRY
884 Only needed when CONFIG_BOOTDELAY is enabled;
885 define a command string that is automatically executed
886 when no character is read on the console interface
887 within "Boot Delay" after reset.
890 This can be used to pass arguments to the bootm
891 command. The value of CONFIG_BOOTARGS goes into the
892 environment value "bootargs".
894 CONFIG_RAMBOOT and CONFIG_NFSBOOT
895 The value of these goes into the environment as
896 "ramboot" and "nfsboot" respectively, and can be used
897 as a convenience, when switching between booting from
901 CONFIG_BOOTCOUNT_LIMIT
902 Implements a mechanism for detecting a repeating reboot
904 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
907 If no softreset save registers are found on the hardware
908 "bootcount" is stored in the environment. To prevent a
909 saveenv on all reboots, the environment variable
910 "upgrade_available" is used. If "upgrade_available" is
911 0, "bootcount" is always 0, if "upgrade_available" is
912 1 "bootcount" is incremented in the environment.
913 So the Userspace Applikation must set the "upgrade_available"
914 and "bootcount" variable to 0, if a boot was successfully.
919 When this option is #defined, the existence of the
920 environment variable "preboot" will be checked
921 immediately before starting the CONFIG_BOOTDELAY
922 countdown and/or running the auto-boot command resp.
923 entering interactive mode.
925 This feature is especially useful when "preboot" is
926 automatically generated or modified. For an example
927 see the LWMON board specific code: here "preboot" is
928 modified when the user holds down a certain
929 combination of keys on the (special) keyboard when
932 - Serial Download Echo Mode:
934 If defined to 1, all characters received during a
935 serial download (using the "loads" command) are
936 echoed back. This might be needed by some terminal
937 emulations (like "cu"), but may as well just take
938 time on others. This setting #define's the initial
939 value of the "loads_echo" environment variable.
941 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
943 Select one of the baudrates listed in
944 CONFIG_SYS_BAUDRATE_TABLE, see below.
947 Monitor commands can be included or excluded
948 from the build by using the #include files
949 <config_cmd_all.h> and #undef'ing unwanted
950 commands, or using <config_cmd_default.h>
951 and augmenting with additional #define's
954 The default command configuration includes all commands
955 except those marked below with a "*".
957 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
958 CONFIG_CMD_ASKENV * ask for env variable
959 CONFIG_CMD_BDI bdinfo
960 CONFIG_CMD_BEDBUG * Include BedBug Debugger
961 CONFIG_CMD_BMP * BMP support
962 CONFIG_CMD_BSP * Board specific commands
963 CONFIG_CMD_BOOTD bootd
964 CONFIG_CMD_CACHE * icache, dcache
965 CONFIG_CMD_CLK * clock command support
966 CONFIG_CMD_CONSOLE coninfo
967 CONFIG_CMD_CRC32 * crc32
968 CONFIG_CMD_DATE * support for RTC, date/time...
969 CONFIG_CMD_DHCP * DHCP support
970 CONFIG_CMD_DIAG * Diagnostics
971 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
972 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
973 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
974 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
975 CONFIG_CMD_DTT * Digital Therm and Thermostat
976 CONFIG_CMD_ECHO echo arguments
977 CONFIG_CMD_EDITENV edit env variable
978 CONFIG_CMD_EEPROM * EEPROM read/write support
979 CONFIG_CMD_ELF * bootelf, bootvx
980 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
981 CONFIG_CMD_ENV_FLAGS * display details about env flags
982 CONFIG_CMD_ENV_EXISTS * check existence of env variable
983 CONFIG_CMD_EXPORTENV * export the environment
984 CONFIG_CMD_EXT2 * ext2 command support
985 CONFIG_CMD_EXT4 * ext4 command support
986 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
987 that work for multiple fs types
988 CONFIG_CMD_SAVEENV saveenv
989 CONFIG_CMD_FDC * Floppy Disk Support
990 CONFIG_CMD_FAT * FAT command support
991 CONFIG_CMD_FLASH flinfo, erase, protect
992 CONFIG_CMD_FPGA FPGA device initialization support
993 CONFIG_CMD_FUSE * Device fuse support
994 CONFIG_CMD_GETTIME * Get time since boot
995 CONFIG_CMD_GO * the 'go' command (exec code)
996 CONFIG_CMD_GREPENV * search environment
997 CONFIG_CMD_HASH * calculate hash / digest
998 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
999 CONFIG_CMD_I2C * I2C serial bus support
1000 CONFIG_CMD_IDE * IDE harddisk support
1001 CONFIG_CMD_IMI iminfo
1002 CONFIG_CMD_IMLS List all images found in NOR flash
1003 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1004 CONFIG_CMD_IMMAP * IMMR dump support
1005 CONFIG_CMD_IMPORTENV * import an environment
1006 CONFIG_CMD_INI * import data from an ini file into the env
1007 CONFIG_CMD_IRQ * irqinfo
1008 CONFIG_CMD_ITEST Integer/string test of 2 values
1009 CONFIG_CMD_JFFS2 * JFFS2 Support
1010 CONFIG_CMD_KGDB * kgdb
1011 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1012 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1014 CONFIG_CMD_LOADB loadb
1015 CONFIG_CMD_LOADS loads
1016 CONFIG_CMD_MD5SUM * print md5 message digest
1017 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1018 CONFIG_CMD_MEMINFO * Display detailed memory information
1019 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1021 CONFIG_CMD_MEMTEST * mtest
1022 CONFIG_CMD_MISC Misc functions like sleep etc
1023 CONFIG_CMD_MMC * MMC memory mapped support
1024 CONFIG_CMD_MII * MII utility commands
1025 CONFIG_CMD_MTDPARTS * MTD partition support
1026 CONFIG_CMD_NAND * NAND support
1027 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1028 CONFIG_CMD_NFS NFS support
1029 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1030 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1031 CONFIG_CMD_PCI * pciinfo
1032 CONFIG_CMD_PCMCIA * PCMCIA support
1033 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1035 CONFIG_CMD_PORTIO * Port I/O
1036 CONFIG_CMD_READ * Read raw data from partition
1037 CONFIG_CMD_REGINFO * Register dump
1038 CONFIG_CMD_RUN run command in env variable
1039 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1040 CONFIG_CMD_SAVES * save S record dump
1041 CONFIG_CMD_SCSI * SCSI Support
1042 CONFIG_CMD_SDRAM * print SDRAM configuration information
1043 (requires CONFIG_CMD_I2C)
1044 CONFIG_CMD_SETGETDCR Support for DCR Register access
1046 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1047 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1048 (requires CONFIG_CMD_MEMORY)
1049 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1050 CONFIG_CMD_SOURCE "source" command Support
1051 CONFIG_CMD_SPI * SPI serial bus support
1052 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1053 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1054 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1055 CONFIG_CMD_TIMER * access to the system tick timer
1056 CONFIG_CMD_USB * USB support
1057 CONFIG_CMD_CDP * Cisco Discover Protocol support
1058 CONFIG_CMD_MFSL * Microblaze FSL support
1059 CONFIG_CMD_XIMG Load part of Multi Image
1060 CONFIG_CMD_UUID * Generate random UUID or GUID string
1062 EXAMPLE: If you want all functions except of network
1063 support you can write:
1065 #include "config_cmd_all.h"
1066 #undef CONFIG_CMD_NET
1069 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1071 Note: Don't enable the "icache" and "dcache" commands
1072 (configuration option CONFIG_CMD_CACHE) unless you know
1073 what you (and your U-Boot users) are doing. Data
1074 cache cannot be enabled on systems like the 8xx or
1075 8260 (where accesses to the IMMR region must be
1076 uncached), and it cannot be disabled on all other
1077 systems where we (mis-) use the data cache to hold an
1078 initial stack and some data.
1081 XXX - this list needs to get updated!
1083 - Regular expression support:
1085 If this variable is defined, U-Boot is linked against
1086 the SLRE (Super Light Regular Expression) library,
1087 which adds regex support to some commands, as for
1088 example "env grep" and "setexpr".
1092 If this variable is defined, U-Boot will use a device tree
1093 to configure its devices, instead of relying on statically
1094 compiled #defines in the board file. This option is
1095 experimental and only available on a few boards. The device
1096 tree is available in the global data as gd->fdt_blob.
1098 U-Boot needs to get its device tree from somewhere. This can
1099 be done using one of the two options below:
1102 If this variable is defined, U-Boot will embed a device tree
1103 binary in its image. This device tree file should be in the
1104 board directory and called <soc>-<board>.dts. The binary file
1105 is then picked up in board_init_f() and made available through
1106 the global data structure as gd->blob.
1109 If this variable is defined, U-Boot will build a device tree
1110 binary. It will be called u-boot.dtb. Architecture-specific
1111 code will locate it at run-time. Generally this works by:
1113 cat u-boot.bin u-boot.dtb >image.bin
1115 and in fact, U-Boot does this for you, creating a file called
1116 u-boot-dtb.bin which is useful in the common case. You can
1117 still use the individual files if you need something more
1122 If this variable is defined, it enables watchdog
1123 support for the SoC. There must be support in the SoC
1124 specific code for a watchdog. For the 8xx and 8260
1125 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1126 register. When supported for a specific SoC is
1127 available, then no further board specific code should
1128 be needed to use it.
1131 When using a watchdog circuitry external to the used
1132 SoC, then define this variable and provide board
1133 specific code for the "hw_watchdog_reset" function.
1136 CONFIG_VERSION_VARIABLE
1137 If this variable is defined, an environment variable
1138 named "ver" is created by U-Boot showing the U-Boot
1139 version as printed by the "version" command.
1140 Any change to this variable will be reverted at the
1145 When CONFIG_CMD_DATE is selected, the type of the RTC
1146 has to be selected, too. Define exactly one of the
1149 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1150 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1151 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1152 CONFIG_RTC_MC146818 - use MC146818 RTC
1153 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1154 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1155 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1156 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1157 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1158 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1159 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1160 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1163 Note that if the RTC uses I2C, then the I2C interface
1164 must also be configured. See I2C Support, below.
1167 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1169 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1170 chip-ngpio pairs that tell the PCA953X driver the number of
1171 pins supported by a particular chip.
1173 Note that if the GPIO device uses I2C, then the I2C interface
1174 must also be configured. See I2C Support, below.
1176 - Timestamp Support:
1178 When CONFIG_TIMESTAMP is selected, the timestamp
1179 (date and time) of an image is printed by image
1180 commands like bootm or iminfo. This option is
1181 automatically enabled when you select CONFIG_CMD_DATE .
1183 - Partition Labels (disklabels) Supported:
1184 Zero or more of the following:
1185 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1186 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1187 Intel architecture, USB sticks, etc.
1188 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1189 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1190 bootloader. Note 2TB partition limit; see
1192 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1194 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1195 CONFIG_CMD_SCSI) you must configure support for at
1196 least one non-MTD partition type as well.
1199 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1200 board configurations files but used nowhere!
1202 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1203 be performed by calling the function
1204 ide_set_reset(int reset)
1205 which has to be defined in a board specific file
1210 Set this to enable ATAPI support.
1215 Set this to enable support for disks larger than 137GB
1216 Also look at CONFIG_SYS_64BIT_LBA.
1217 Whithout these , LBA48 support uses 32bit variables and will 'only'
1218 support disks up to 2.1TB.
1220 CONFIG_SYS_64BIT_LBA:
1221 When enabled, makes the IDE subsystem use 64bit sector addresses.
1225 At the moment only there is only support for the
1226 SYM53C8XX SCSI controller; define
1227 CONFIG_SCSI_SYM53C8XX to enable it.
1229 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1230 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1231 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1232 maximum numbers of LUNs, SCSI ID's and target
1234 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1236 The environment variable 'scsidevs' is set to the number of
1237 SCSI devices found during the last scan.
1239 - NETWORK Support (PCI):
1241 Support for Intel 8254x/8257x gigabit chips.
1244 Utility code for direct access to the SPI bus on Intel 8257x.
1245 This does not do anything useful unless you set at least one
1246 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1248 CONFIG_E1000_SPI_GENERIC
1249 Allow generic access to the SPI bus on the Intel 8257x, for
1250 example with the "sspi" command.
1253 Management command for E1000 devices. When used on devices
1254 with SPI support you can reprogram the EEPROM from U-Boot.
1256 CONFIG_E1000_FALLBACK_MAC
1257 default MAC for empty EEPROM after production.
1260 Support for Intel 82557/82559/82559ER chips.
1261 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1262 write routine for first time initialisation.
1265 Support for Digital 2114x chips.
1266 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1267 modem chip initialisation (KS8761/QS6611).
1270 Support for National dp83815 chips.
1273 Support for National dp8382[01] gigabit chips.
1275 - NETWORK Support (other):
1277 CONFIG_DRIVER_AT91EMAC
1278 Support for AT91RM9200 EMAC.
1281 Define this to use reduced MII inteface
1283 CONFIG_DRIVER_AT91EMAC_QUIET
1284 If this defined, the driver is quiet.
1285 The driver doen't show link status messages.
1287 CONFIG_CALXEDA_XGMAC
1288 Support for the Calxeda XGMAC device
1291 Support for SMSC's LAN91C96 chips.
1293 CONFIG_LAN91C96_BASE
1294 Define this to hold the physical address
1295 of the LAN91C96's I/O space
1297 CONFIG_LAN91C96_USE_32_BIT
1298 Define this to enable 32 bit addressing
1301 Support for SMSC's LAN91C111 chip
1303 CONFIG_SMC91111_BASE
1304 Define this to hold the physical address
1305 of the device (I/O space)
1307 CONFIG_SMC_USE_32_BIT
1308 Define this if data bus is 32 bits
1310 CONFIG_SMC_USE_IOFUNCS
1311 Define this to use i/o functions instead of macros
1312 (some hardware wont work with macros)
1314 CONFIG_DRIVER_TI_EMAC
1315 Support for davinci emac
1317 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1318 Define this if you have more then 3 PHYs.
1321 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1323 CONFIG_FTGMAC100_EGIGA
1324 Define this to use GE link update with gigabit PHY.
1325 Define this if FTGMAC100 is connected to gigabit PHY.
1326 If your system has 10/100 PHY only, it might not occur
1327 wrong behavior. Because PHY usually return timeout or
1328 useless data when polling gigabit status and gigabit
1329 control registers. This behavior won't affect the
1330 correctnessof 10/100 link speed update.
1333 Support for SMSC's LAN911x and LAN921x chips
1336 Define this to hold the physical address
1337 of the device (I/O space)
1339 CONFIG_SMC911X_32_BIT
1340 Define this if data bus is 32 bits
1342 CONFIG_SMC911X_16_BIT
1343 Define this if data bus is 16 bits. If your processor
1344 automatically converts one 32 bit word to two 16 bit
1345 words you may also try CONFIG_SMC911X_32_BIT.
1348 Support for Renesas on-chip Ethernet controller
1350 CONFIG_SH_ETHER_USE_PORT
1351 Define the number of ports to be used
1353 CONFIG_SH_ETHER_PHY_ADDR
1354 Define the ETH PHY's address
1356 CONFIG_SH_ETHER_CACHE_WRITEBACK
1357 If this option is set, the driver enables cache flush.
1361 Support TPM devices.
1364 Support for i2c bus TPM devices. Only one device
1365 per system is supported at this time.
1367 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1368 Define the the i2c bus number for the TPM device
1370 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1371 Define the TPM's address on the i2c bus
1373 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1374 Define the burst count bytes upper limit
1376 CONFIG_TPM_ATMEL_TWI
1377 Support for Atmel TWI TPM device. Requires I2C support.
1380 Support for generic parallel port TPM devices. Only one device
1381 per system is supported at this time.
1383 CONFIG_TPM_TIS_BASE_ADDRESS
1384 Base address where the generic TPM device is mapped
1385 to. Contemporary x86 systems usually map it at
1389 Add tpm monitor functions.
1390 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1391 provides monitor access to authorized functions.
1394 Define this to enable the TPM support library which provides
1395 functional interfaces to some TPM commands.
1396 Requires support for a TPM device.
1398 CONFIG_TPM_AUTH_SESSIONS
1399 Define this to enable authorized functions in the TPM library.
1400 Requires CONFIG_TPM and CONFIG_SHA1.
1403 At the moment only the UHCI host controller is
1404 supported (PIP405, MIP405, MPC5200); define
1405 CONFIG_USB_UHCI to enable it.
1406 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1407 and define CONFIG_USB_STORAGE to enable the USB
1410 Supported are USB Keyboards and USB Floppy drives
1412 MPC5200 USB requires additional defines:
1414 for 528 MHz Clock: 0x0001bbbb
1418 for differential drivers: 0x00001000
1419 for single ended drivers: 0x00005000
1420 for differential drivers on PSC3: 0x00000100
1421 for single ended drivers on PSC3: 0x00004100
1422 CONFIG_SYS_USB_EVENT_POLL
1423 May be defined to allow interrupt polling
1424 instead of using asynchronous interrupts
1426 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1427 txfilltuning field in the EHCI controller on reset.
1429 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1430 interval for usb hub power-on delay.(minimum 100msec)
1433 Define the below if you wish to use the USB console.
1434 Once firmware is rebuilt from a serial console issue the
1435 command "setenv stdin usbtty; setenv stdout usbtty" and
1436 attach your USB cable. The Unix command "dmesg" should print
1437 it has found a new device. The environment variable usbtty
1438 can be set to gserial or cdc_acm to enable your device to
1439 appear to a USB host as a Linux gserial device or a
1440 Common Device Class Abstract Control Model serial device.
1441 If you select usbtty = gserial you should be able to enumerate
1443 # modprobe usbserial vendor=0xVendorID product=0xProductID
1444 else if using cdc_acm, simply setting the environment
1445 variable usbtty to be cdc_acm should suffice. The following
1446 might be defined in YourBoardName.h
1449 Define this to build a UDC device
1452 Define this to have a tty type of device available to
1453 talk to the UDC device
1456 Define this to enable the high speed support for usb
1457 device and usbtty. If this feature is enabled, a routine
1458 int is_usbd_high_speed(void)
1459 also needs to be defined by the driver to dynamically poll
1460 whether the enumeration has succeded at high speed or full
1463 CONFIG_SYS_CONSOLE_IS_IN_ENV
1464 Define this if you want stdin, stdout &/or stderr to
1468 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1469 Derive USB clock from external clock "blah"
1470 - CONFIG_SYS_USB_EXTC_CLK 0x02
1472 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1473 Derive USB clock from brgclk
1474 - CONFIG_SYS_USB_BRG_CLK 0x04
1476 If you have a USB-IF assigned VendorID then you may wish to
1477 define your own vendor specific values either in BoardName.h
1478 or directly in usbd_vendor_info.h. If you don't define
1479 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1480 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1481 should pretend to be a Linux device to it's target host.
1483 CONFIG_USBD_MANUFACTURER
1484 Define this string as the name of your company for
1485 - CONFIG_USBD_MANUFACTURER "my company"
1487 CONFIG_USBD_PRODUCT_NAME
1488 Define this string as the name of your product
1489 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1491 CONFIG_USBD_VENDORID
1492 Define this as your assigned Vendor ID from the USB
1493 Implementors Forum. This *must* be a genuine Vendor ID
1494 to avoid polluting the USB namespace.
1495 - CONFIG_USBD_VENDORID 0xFFFF
1497 CONFIG_USBD_PRODUCTID
1498 Define this as the unique Product ID
1500 - CONFIG_USBD_PRODUCTID 0xFFFF
1502 - ULPI Layer Support:
1503 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1504 the generic ULPI layer. The generic layer accesses the ULPI PHY
1505 via the platform viewport, so you need both the genric layer and
1506 the viewport enabled. Currently only Chipidea/ARC based
1507 viewport is supported.
1508 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1509 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1510 If your ULPI phy needs a different reference clock than the
1511 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1512 the appropriate value in Hz.
1515 The MMC controller on the Intel PXA is supported. To
1516 enable this define CONFIG_MMC. The MMC can be
1517 accessed from the boot prompt by mapping the device
1518 to physical memory similar to flash. Command line is
1519 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1520 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1523 Support for Renesas on-chip MMCIF controller
1525 CONFIG_SH_MMCIF_ADDR
1526 Define the base address of MMCIF registers
1529 Define the clock frequency for MMCIF
1531 - USB Device Firmware Update (DFU) class support:
1533 This enables the USB portion of the DFU USB class
1536 This enables the command "dfu" which is used to have
1537 U-Boot create a DFU class device via USB. This command
1538 requires that the "dfu_alt_info" environment variable be
1539 set and define the alt settings to expose to the host.
1542 This enables support for exposing (e)MMC devices via DFU.
1545 This enables support for exposing NAND devices via DFU.
1548 This enables support for exposing RAM via DFU.
1549 Note: DFU spec refer to non-volatile memory usage, but
1550 allow usages beyond the scope of spec - here RAM usage,
1551 one that would help mostly the developer.
1553 CONFIG_SYS_DFU_DATA_BUF_SIZE
1554 Dfu transfer uses a buffer before writing data to the
1555 raw storage device. Make the size (in bytes) of this buffer
1556 configurable. The size of this buffer is also configurable
1557 through the "dfu_bufsiz" environment variable.
1559 CONFIG_SYS_DFU_MAX_FILE_SIZE
1560 When updating files rather than the raw storage device,
1561 we use a static buffer to copy the file into and then write
1562 the buffer once we've been given the whole file. Define
1563 this to the maximum filesize (in bytes) for the buffer.
1564 Default is 4 MiB if undefined.
1566 DFU_DEFAULT_POLL_TIMEOUT
1567 Poll timeout [ms], is the timeout a device can send to the
1568 host. The host must wait for this timeout before sending
1569 a subsequent DFU_GET_STATUS request to the device.
1571 DFU_MANIFEST_POLL_TIMEOUT
1572 Poll timeout [ms], which the device sends to the host when
1573 entering dfuMANIFEST state. Host waits this timeout, before
1574 sending again an USB request to the device.
1576 - Journaling Flash filesystem support:
1577 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1578 CONFIG_JFFS2_NAND_DEV
1579 Define these for a default partition on a NAND device
1581 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1582 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1583 Define these for a default partition on a NOR device
1585 CONFIG_SYS_JFFS_CUSTOM_PART
1586 Define this to create an own partition. You have to provide a
1587 function struct part_info* jffs2_part_info(int part_num)
1589 If you define only one JFFS2 partition you may also want to
1590 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1591 to disable the command chpart. This is the default when you
1592 have not defined a custom partition
1594 - FAT(File Allocation Table) filesystem write function support:
1597 Define this to enable support for saving memory data as a
1598 file in FAT formatted partition.
1600 This will also enable the command "fatwrite" enabling the
1601 user to write files to FAT.
1603 CBFS (Coreboot Filesystem) support
1606 Define this to enable support for reading from a Coreboot
1607 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1613 Define this to enable standard (PC-Style) keyboard
1617 Standard PC keyboard driver with US (is default) and
1618 GERMAN key layout (switch via environment 'keymap=de') support.
1619 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1620 for cfb_console. Supports cursor blinking.
1623 Enables a Chrome OS keyboard using the CROS_EC interface.
1624 This uses CROS_EC to communicate with a second microcontroller
1625 which provides key scans on request.
1630 Define this to enable video support (for output to
1633 CONFIG_VIDEO_CT69000
1635 Enable Chips & Technologies 69000 Video chip
1637 CONFIG_VIDEO_SMI_LYNXEM
1638 Enable Silicon Motion SMI 712/710/810 Video chip. The
1639 video output is selected via environment 'videoout'
1640 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1643 For the CT69000 and SMI_LYNXEM drivers, videomode is
1644 selected via environment 'videomode'. Two different ways
1646 - "videomode=num" 'num' is a standard LiLo mode numbers.
1647 Following standard modes are supported (* is default):
1649 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1650 -------------+---------------------------------------------
1651 8 bits | 0x301* 0x303 0x305 0x161 0x307
1652 15 bits | 0x310 0x313 0x316 0x162 0x319
1653 16 bits | 0x311 0x314 0x317 0x163 0x31A
1654 24 bits | 0x312 0x315 0x318 ? 0x31B
1655 -------------+---------------------------------------------
1656 (i.e. setenv videomode 317; saveenv; reset;)
1658 - "videomode=bootargs" all the video parameters are parsed
1659 from the bootargs. (See drivers/video/videomodes.c)
1662 CONFIG_VIDEO_SED13806
1663 Enable Epson SED13806 driver. This driver supports 8bpp
1664 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1665 or CONFIG_VIDEO_SED13806_16BPP
1668 Enable the Freescale DIU video driver. Reference boards for
1669 SOCs that have a DIU should define this macro to enable DIU
1670 support, and should also define these other macros:
1676 CONFIG_VIDEO_SW_CURSOR
1677 CONFIG_VGA_AS_SINGLE_DEVICE
1679 CONFIG_VIDEO_BMP_LOGO
1681 The DIU driver will look for the 'video-mode' environment
1682 variable, and if defined, enable the DIU as a console during
1683 boot. See the documentation file README.video for a
1684 description of this variable.
1688 Enable the VGA video / BIOS for x86. The alternative if you
1689 are using coreboot is to use the coreboot frame buffer
1696 Define this to enable a custom keyboard support.
1697 This simply calls drv_keyboard_init() which must be
1698 defined in your board-specific files.
1699 The only board using this so far is RBC823.
1701 - LCD Support: CONFIG_LCD
1703 Define this to enable LCD support (for output to LCD
1704 display); also select one of the supported displays
1705 by defining one of these:
1709 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1711 CONFIG_NEC_NL6448AC33:
1713 NEC NL6448AC33-18. Active, color, single scan.
1715 CONFIG_NEC_NL6448BC20
1717 NEC NL6448BC20-08. 6.5", 640x480.
1718 Active, color, single scan.
1720 CONFIG_NEC_NL6448BC33_54
1722 NEC NL6448BC33-54. 10.4", 640x480.
1723 Active, color, single scan.
1727 Sharp 320x240. Active, color, single scan.
1728 It isn't 16x9, and I am not sure what it is.
1730 CONFIG_SHARP_LQ64D341
1732 Sharp LQ64D341 display, 640x480.
1733 Active, color, single scan.
1737 HLD1045 display, 640x480.
1738 Active, color, single scan.
1742 Optrex CBL50840-2 NF-FW 99 22 M5
1744 Hitachi LMG6912RPFC-00T
1748 320x240. Black & white.
1750 Normally display is black on white background; define
1751 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1753 CONFIG_LCD_ALIGNMENT
1755 Normally the LCD is page-aligned (tyically 4KB). If this is
1756 defined then the LCD will be aligned to this value instead.
1757 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1758 here, since it is cheaper to change data cache settings on
1759 a per-section basis.
1761 CONFIG_CONSOLE_SCROLL_LINES
1763 When the console need to be scrolled, this is the number of
1764 lines to scroll by. It defaults to 1. Increasing this makes
1765 the console jump but can help speed up operation when scrolling
1770 Support drawing of RLE8-compressed bitmaps on the LCD.
1774 Enables an 'i2c edid' command which can read EDID
1775 information over I2C from an attached LCD display.
1777 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1779 If this option is set, the environment is checked for
1780 a variable "splashimage". If found, the usual display
1781 of logo, copyright and system information on the LCD
1782 is suppressed and the BMP image at the address
1783 specified in "splashimage" is loaded instead. The
1784 console is redirected to the "nulldev", too. This
1785 allows for a "silent" boot where a splash screen is
1786 loaded very quickly after power-on.
1788 CONFIG_SPLASHIMAGE_GUARD
1790 If this option is set, then U-Boot will prevent the environment
1791 variable "splashimage" from being set to a problematic address
1792 (see README.displaying-bmps).
1793 This option is useful for targets where, due to alignment
1794 restrictions, an improperly aligned BMP image will cause a data
1795 abort. If you think you will not have problems with unaligned
1796 accesses (for example because your toolchain prevents them)
1797 there is no need to set this option.
1799 CONFIG_SPLASH_SCREEN_ALIGN
1801 If this option is set the splash image can be freely positioned
1802 on the screen. Environment variable "splashpos" specifies the
1803 position as "x,y". If a positive number is given it is used as
1804 number of pixel from left/top. If a negative number is given it
1805 is used as number of pixel from right/bottom. You can also
1806 specify 'm' for centering the image.
1809 setenv splashpos m,m
1810 => image at center of screen
1812 setenv splashpos 30,20
1813 => image at x = 30 and y = 20
1815 setenv splashpos -10,m
1816 => vertically centered image
1817 at x = dspWidth - bmpWidth - 9
1819 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1821 If this option is set, additionally to standard BMP
1822 images, gzipped BMP images can be displayed via the
1823 splashscreen support or the bmp command.
1825 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1827 If this option is set, 8-bit RLE compressed BMP images
1828 can be displayed via the splashscreen support or the
1831 - Do compresssing for memory range:
1834 If this option is set, it would use zlib deflate method
1835 to compress the specified memory at its best effort.
1837 - Compression support:
1840 Enabled by default to support gzip compressed images.
1844 If this option is set, support for bzip2 compressed
1845 images is included. If not, only uncompressed and gzip
1846 compressed images are supported.
1848 NOTE: the bzip2 algorithm requires a lot of RAM, so
1849 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1854 If this option is set, support for lzma compressed
1857 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1858 requires an amount of dynamic memory that is given by the
1861 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1863 Where lc and lp stand for, respectively, Literal context bits
1864 and Literal pos bits.
1866 This value is upper-bounded by 14MB in the worst case. Anyway,
1867 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1868 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1869 a very small buffer.
1871 Use the lzmainfo tool to determinate the lc and lp values and
1872 then calculate the amount of needed dynamic memory (ensuring
1873 the appropriate CONFIG_SYS_MALLOC_LEN value).
1877 If this option is set, support for LZO compressed images
1883 The address of PHY on MII bus.
1885 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1887 The clock frequency of the MII bus
1891 If this option is set, support for speed/duplex
1892 detection of gigabit PHY is included.
1894 CONFIG_PHY_RESET_DELAY
1896 Some PHY like Intel LXT971A need extra delay after
1897 reset before any MII register access is possible.
1898 For such PHY, set this option to the usec delay
1899 required. (minimum 300usec for LXT971A)
1901 CONFIG_PHY_CMD_DELAY (ppc4xx)
1903 Some PHY like Intel LXT971A need extra delay after
1904 command issued before MII status register can be read
1914 Define a default value for Ethernet address to use
1915 for the respective Ethernet interface, in case this
1916 is not determined automatically.
1921 Define a default value for the IP address to use for
1922 the default Ethernet interface, in case this is not
1923 determined through e.g. bootp.
1924 (Environment variable "ipaddr")
1926 - Server IP address:
1929 Defines a default value for the IP address of a TFTP
1930 server to contact when using the "tftboot" command.
1931 (Environment variable "serverip")
1933 CONFIG_KEEP_SERVERADDR
1935 Keeps the server's MAC address, in the env 'serveraddr'
1936 for passing to bootargs (like Linux's netconsole option)
1938 - Gateway IP address:
1941 Defines a default value for the IP address of the
1942 default router where packets to other networks are
1944 (Environment variable "gatewayip")
1949 Defines a default value for the subnet mask (or
1950 routing prefix) which is used to determine if an IP
1951 address belongs to the local subnet or needs to be
1952 forwarded through a router.
1953 (Environment variable "netmask")
1955 - Multicast TFTP Mode:
1958 Defines whether you want to support multicast TFTP as per
1959 rfc-2090; for example to work with atftp. Lets lots of targets
1960 tftp down the same boot image concurrently. Note: the Ethernet
1961 driver in use must provide a function: mcast() to join/leave a
1964 - BOOTP Recovery Mode:
1965 CONFIG_BOOTP_RANDOM_DELAY
1967 If you have many targets in a network that try to
1968 boot using BOOTP, you may want to avoid that all
1969 systems send out BOOTP requests at precisely the same
1970 moment (which would happen for instance at recovery
1971 from a power failure, when all systems will try to
1972 boot, thus flooding the BOOTP server. Defining
1973 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1974 inserted before sending out BOOTP requests. The
1975 following delays are inserted then:
1977 1st BOOTP request: delay 0 ... 1 sec
1978 2nd BOOTP request: delay 0 ... 2 sec
1979 3rd BOOTP request: delay 0 ... 4 sec
1981 BOOTP requests: delay 0 ... 8 sec
1983 - DHCP Advanced Options:
1984 You can fine tune the DHCP functionality by defining
1985 CONFIG_BOOTP_* symbols:
1987 CONFIG_BOOTP_SUBNETMASK
1988 CONFIG_BOOTP_GATEWAY
1989 CONFIG_BOOTP_HOSTNAME
1990 CONFIG_BOOTP_NISDOMAIN
1991 CONFIG_BOOTP_BOOTPATH
1992 CONFIG_BOOTP_BOOTFILESIZE
1995 CONFIG_BOOTP_SEND_HOSTNAME
1996 CONFIG_BOOTP_NTPSERVER
1997 CONFIG_BOOTP_TIMEOFFSET
1998 CONFIG_BOOTP_VENDOREX
1999 CONFIG_BOOTP_MAY_FAIL
2001 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2002 environment variable, not the BOOTP server.
2004 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2005 after the configured retry count, the call will fail
2006 instead of starting over. This can be used to fail over
2007 to Link-local IP address configuration if the DHCP server
2010 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2011 serverip from a DHCP server, it is possible that more
2012 than one DNS serverip is offered to the client.
2013 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2014 serverip will be stored in the additional environment
2015 variable "dnsip2". The first DNS serverip is always
2016 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2019 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2020 to do a dynamic update of a DNS server. To do this, they
2021 need the hostname of the DHCP requester.
2022 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2023 of the "hostname" environment variable is passed as
2024 option 12 to the DHCP server.
2026 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2028 A 32bit value in microseconds for a delay between
2029 receiving a "DHCP Offer" and sending the "DHCP Request".
2030 This fixes a problem with certain DHCP servers that don't
2031 respond 100% of the time to a "DHCP request". E.g. On an
2032 AT91RM9200 processor running at 180MHz, this delay needed
2033 to be *at least* 15,000 usec before a Windows Server 2003
2034 DHCP server would reply 100% of the time. I recommend at
2035 least 50,000 usec to be safe. The alternative is to hope
2036 that one of the retries will be successful but note that
2037 the DHCP timeout and retry process takes a longer than
2040 - Link-local IP address negotiation:
2041 Negotiate with other link-local clients on the local network
2042 for an address that doesn't require explicit configuration.
2043 This is especially useful if a DHCP server cannot be guaranteed
2044 to exist in all environments that the device must operate.
2046 See doc/README.link-local for more information.
2049 CONFIG_CDP_DEVICE_ID
2051 The device id used in CDP trigger frames.
2053 CONFIG_CDP_DEVICE_ID_PREFIX
2055 A two character string which is prefixed to the MAC address
2060 A printf format string which contains the ascii name of
2061 the port. Normally is set to "eth%d" which sets
2062 eth0 for the first Ethernet, eth1 for the second etc.
2064 CONFIG_CDP_CAPABILITIES
2066 A 32bit integer which indicates the device capabilities;
2067 0x00000010 for a normal host which does not forwards.
2071 An ascii string containing the version of the software.
2075 An ascii string containing the name of the platform.
2079 A 32bit integer sent on the trigger.
2081 CONFIG_CDP_POWER_CONSUMPTION
2083 A 16bit integer containing the power consumption of the
2084 device in .1 of milliwatts.
2086 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2088 A byte containing the id of the VLAN.
2090 - Status LED: CONFIG_STATUS_LED
2092 Several configurations allow to display the current
2093 status using a LED. For instance, the LED will blink
2094 fast while running U-Boot code, stop blinking as
2095 soon as a reply to a BOOTP request was received, and
2096 start blinking slow once the Linux kernel is running
2097 (supported by a status LED driver in the Linux
2098 kernel). Defining CONFIG_STATUS_LED enables this
2104 The status LED can be connected to a GPIO pin.
2105 In such cases, the gpio_led driver can be used as a
2106 status LED backend implementation. Define CONFIG_GPIO_LED
2107 to include the gpio_led driver in the U-Boot binary.
2109 CONFIG_GPIO_LED_INVERTED_TABLE
2110 Some GPIO connected LEDs may have inverted polarity in which
2111 case the GPIO high value corresponds to LED off state and
2112 GPIO low value corresponds to LED on state.
2113 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2114 with a list of GPIO LEDs that have inverted polarity.
2116 - CAN Support: CONFIG_CAN_DRIVER
2118 Defining CONFIG_CAN_DRIVER enables CAN driver support
2119 on those systems that support this (optional)
2120 feature, like the TQM8xxL modules.
2122 - I2C Support: CONFIG_SYS_I2C
2124 This enable the NEW i2c subsystem, and will allow you to use
2125 i2c commands at the u-boot command line (as long as you set
2126 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2127 based realtime clock chips or other i2c devices. See
2128 common/cmd_i2c.c for a description of the command line
2131 ported i2c driver to the new framework:
2132 - drivers/i2c/soft_i2c.c:
2133 - activate first bus with CONFIG_SYS_I2C_SOFT define
2134 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2135 for defining speed and slave address
2136 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2137 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2138 for defining speed and slave address
2139 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2140 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2141 for defining speed and slave address
2142 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2143 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2144 for defining speed and slave address
2146 - drivers/i2c/fsl_i2c.c:
2147 - activate i2c driver with CONFIG_SYS_I2C_FSL
2148 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2149 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2150 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2152 - If your board supports a second fsl i2c bus, define
2153 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2154 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2155 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2158 - drivers/i2c/tegra_i2c.c:
2159 - activate this driver with CONFIG_SYS_I2C_TEGRA
2160 - This driver adds 4 i2c buses with a fix speed from
2161 100000 and the slave addr 0!
2163 - drivers/i2c/ppc4xx_i2c.c
2164 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2165 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2166 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2168 - drivers/i2c/i2c_mxc.c
2169 - activate this driver with CONFIG_SYS_I2C_MXC
2170 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2171 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2172 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2173 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2174 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2175 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2176 If thoses defines are not set, default value is 100000
2177 for speed, and 0 for slave.
2179 - drivers/i2c/rcar_i2c.c:
2180 - activate this driver with CONFIG_SYS_I2C_RCAR
2181 - This driver adds 4 i2c buses
2183 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2184 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2185 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2186 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2187 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2188 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2189 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2190 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2191 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2193 - drivers/i2c/sh_i2c.c:
2194 - activate this driver with CONFIG_SYS_I2C_SH
2195 - This driver adds from 2 to 5 i2c buses
2197 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2198 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2199 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2200 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2201 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2202 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2203 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2204 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2205 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2206 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2207 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2208 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2209 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2211 - drivers/i2c/omap24xx_i2c.c
2212 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2213 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2214 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2215 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2216 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2217 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2218 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2219 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2220 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2221 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2222 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2224 - drivers/i2c/zynq_i2c.c
2225 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2226 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2227 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2229 - drivers/i2c/s3c24x0_i2c.c:
2230 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2231 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2232 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2233 with a fix speed from 100000 and the slave addr 0!
2237 CONFIG_SYS_NUM_I2C_BUSES
2238 Hold the number of i2c busses you want to use. If you
2239 don't use/have i2c muxes on your i2c bus, this
2240 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2243 CONFIG_SYS_I2C_DIRECT_BUS
2244 define this, if you don't use i2c muxes on your hardware.
2245 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2248 CONFIG_SYS_I2C_MAX_HOPS
2249 define how many muxes are maximal consecutively connected
2250 on one i2c bus. If you not use i2c muxes, omit this
2253 CONFIG_SYS_I2C_BUSES
2254 hold a list of busses you want to use, only used if
2255 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2256 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2257 CONFIG_SYS_NUM_I2C_BUSES = 9:
2259 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2260 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2261 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2262 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2263 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2264 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2265 {1, {I2C_NULL_HOP}}, \
2266 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2267 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2271 bus 0 on adapter 0 without a mux
2272 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2273 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2274 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2275 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2276 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2277 bus 6 on adapter 1 without a mux
2278 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2279 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2281 If you do not have i2c muxes on your board, omit this define.
2283 - Legacy I2C Support: CONFIG_HARD_I2C
2285 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2286 provides the following compelling advantages:
2288 - more than one i2c adapter is usable
2289 - approved multibus support
2290 - better i2c mux support
2292 ** Please consider updating your I2C driver now. **
2294 These enable legacy I2C serial bus commands. Defining
2295 CONFIG_HARD_I2C will include the appropriate I2C driver
2296 for the selected CPU.
2298 This will allow you to use i2c commands at the u-boot
2299 command line (as long as you set CONFIG_CMD_I2C in
2300 CONFIG_COMMANDS) and communicate with i2c based realtime
2301 clock chips. See common/cmd_i2c.c for a description of the
2302 command line interface.
2304 CONFIG_HARD_I2C selects a hardware I2C controller.
2306 There are several other quantities that must also be
2307 defined when you define CONFIG_HARD_I2C.
2309 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2310 to be the frequency (in Hz) at which you wish your i2c bus
2311 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2312 the CPU's i2c node address).
2314 Now, the u-boot i2c code for the mpc8xx
2315 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2316 and so its address should therefore be cleared to 0 (See,
2317 eg, MPC823e User's Manual p.16-473). So, set
2318 CONFIG_SYS_I2C_SLAVE to 0.
2320 CONFIG_SYS_I2C_INIT_MPC5XXX
2322 When a board is reset during an i2c bus transfer
2323 chips might think that the current transfer is still
2324 in progress. Reset the slave devices by sending start
2325 commands until the slave device responds.
2327 That's all that's required for CONFIG_HARD_I2C.
2329 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2330 then the following macros need to be defined (examples are
2331 from include/configs/lwmon.h):
2335 (Optional). Any commands necessary to enable the I2C
2336 controller or configure ports.
2338 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2342 (Only for MPC8260 CPU). The I/O port to use (the code
2343 assumes both bits are on the same port). Valid values
2344 are 0..3 for ports A..D.
2348 The code necessary to make the I2C data line active
2349 (driven). If the data line is open collector, this
2352 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2356 The code necessary to make the I2C data line tri-stated
2357 (inactive). If the data line is open collector, this
2360 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2364 Code that returns true if the I2C data line is high,
2367 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2371 If <bit> is true, sets the I2C data line high. If it
2372 is false, it clears it (low).
2374 eg: #define I2C_SDA(bit) \
2375 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2376 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2380 If <bit> is true, sets the I2C clock line high. If it
2381 is false, it clears it (low).
2383 eg: #define I2C_SCL(bit) \
2384 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2385 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2389 This delay is invoked four times per clock cycle so this
2390 controls the rate of data transfer. The data rate thus
2391 is 1 / (I2C_DELAY * 4). Often defined to be something
2394 #define I2C_DELAY udelay(2)
2396 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2398 If your arch supports the generic GPIO framework (asm/gpio.h),
2399 then you may alternatively define the two GPIOs that are to be
2400 used as SCL / SDA. Any of the previous I2C_xxx macros will
2401 have GPIO-based defaults assigned to them as appropriate.
2403 You should define these to the GPIO value as given directly to
2404 the generic GPIO functions.
2406 CONFIG_SYS_I2C_INIT_BOARD
2408 When a board is reset during an i2c bus transfer
2409 chips might think that the current transfer is still
2410 in progress. On some boards it is possible to access
2411 the i2c SCLK line directly, either by using the
2412 processor pin as a GPIO or by having a second pin
2413 connected to the bus. If this option is defined a
2414 custom i2c_init_board() routine in boards/xxx/board.c
2415 is run early in the boot sequence.
2417 CONFIG_SYS_I2C_BOARD_LATE_INIT
2419 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2420 defined a custom i2c_board_late_init() routine in
2421 boards/xxx/board.c is run AFTER the operations in i2c_init()
2422 is completed. This callpoint can be used to unreset i2c bus
2423 using CPU i2c controller register accesses for CPUs whose i2c
2424 controller provide such a method. It is called at the end of
2425 i2c_init() to allow i2c_init operations to setup the i2c bus
2426 controller on the CPU (e.g. setting bus speed & slave address).
2428 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2430 This option enables configuration of bi_iic_fast[] flags
2431 in u-boot bd_info structure based on u-boot environment
2432 variable "i2cfast". (see also i2cfast)
2434 CONFIG_I2C_MULTI_BUS
2436 This option allows the use of multiple I2C buses, each of which
2437 must have a controller. At any point in time, only one bus is
2438 active. To switch to a different bus, use the 'i2c dev' command.
2439 Note that bus numbering is zero-based.
2441 CONFIG_SYS_I2C_NOPROBES
2443 This option specifies a list of I2C devices that will be skipped
2444 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2445 is set, specify a list of bus-device pairs. Otherwise, specify
2446 a 1D array of device addresses
2449 #undef CONFIG_I2C_MULTI_BUS
2450 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2452 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2454 #define CONFIG_I2C_MULTI_BUS
2455 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2457 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2459 CONFIG_SYS_SPD_BUS_NUM
2461 If defined, then this indicates the I2C bus number for DDR SPD.
2462 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2464 CONFIG_SYS_RTC_BUS_NUM
2466 If defined, then this indicates the I2C bus number for the RTC.
2467 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2469 CONFIG_SYS_DTT_BUS_NUM
2471 If defined, then this indicates the I2C bus number for the DTT.
2472 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2474 CONFIG_SYS_I2C_DTT_ADDR:
2476 If defined, specifies the I2C address of the DTT device.
2477 If not defined, then U-Boot uses predefined value for
2478 specified DTT device.
2480 CONFIG_SOFT_I2C_READ_REPEATED_START
2482 defining this will force the i2c_read() function in
2483 the soft_i2c driver to perform an I2C repeated start
2484 between writing the address pointer and reading the
2485 data. If this define is omitted the default behaviour
2486 of doing a stop-start sequence will be used. Most I2C
2487 devices can use either method, but some require one or
2490 - SPI Support: CONFIG_SPI
2492 Enables SPI driver (so far only tested with
2493 SPI EEPROM, also an instance works with Crystal A/D and
2494 D/As on the SACSng board)
2498 Enables the driver for SPI controller on SuperH. Currently
2499 only SH7757 is supported.
2503 Enables extended (16-bit) SPI EEPROM addressing.
2504 (symmetrical to CONFIG_I2C_X)
2508 Enables a software (bit-bang) SPI driver rather than
2509 using hardware support. This is a general purpose
2510 driver that only requires three general I/O port pins
2511 (two outputs, one input) to function. If this is
2512 defined, the board configuration must define several
2513 SPI configuration items (port pins to use, etc). For
2514 an example, see include/configs/sacsng.h.
2518 Enables a hardware SPI driver for general-purpose reads
2519 and writes. As with CONFIG_SOFT_SPI, the board configuration
2520 must define a list of chip-select function pointers.
2521 Currently supported on some MPC8xxx processors. For an
2522 example, see include/configs/mpc8349emds.h.
2526 Enables the driver for the SPI controllers on i.MX and MXC
2527 SoCs. Currently i.MX31/35/51 are supported.
2529 - FPGA Support: CONFIG_FPGA
2531 Enables FPGA subsystem.
2533 CONFIG_FPGA_<vendor>
2535 Enables support for specific chip vendors.
2538 CONFIG_FPGA_<family>
2540 Enables support for FPGA family.
2541 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2545 Specify the number of FPGA devices to support.
2547 CONFIG_SYS_FPGA_PROG_FEEDBACK
2549 Enable printing of hash marks during FPGA configuration.
2551 CONFIG_SYS_FPGA_CHECK_BUSY
2553 Enable checks on FPGA configuration interface busy
2554 status by the configuration function. This option
2555 will require a board or device specific function to
2560 If defined, a function that provides delays in the FPGA
2561 configuration driver.
2563 CONFIG_SYS_FPGA_CHECK_CTRLC
2564 Allow Control-C to interrupt FPGA configuration
2566 CONFIG_SYS_FPGA_CHECK_ERROR
2568 Check for configuration errors during FPGA bitfile
2569 loading. For example, abort during Virtex II
2570 configuration if the INIT_B line goes low (which
2571 indicated a CRC error).
2573 CONFIG_SYS_FPGA_WAIT_INIT
2575 Maximum time to wait for the INIT_B line to deassert
2576 after PROB_B has been deasserted during a Virtex II
2577 FPGA configuration sequence. The default time is 500
2580 CONFIG_SYS_FPGA_WAIT_BUSY
2582 Maximum time to wait for BUSY to deassert during
2583 Virtex II FPGA configuration. The default is 5 ms.
2585 CONFIG_SYS_FPGA_WAIT_CONFIG
2587 Time to wait after FPGA configuration. The default is
2590 - Configuration Management:
2593 If defined, this string will be added to the U-Boot
2594 version information (U_BOOT_VERSION)
2596 - Vendor Parameter Protection:
2598 U-Boot considers the values of the environment
2599 variables "serial#" (Board Serial Number) and
2600 "ethaddr" (Ethernet Address) to be parameters that
2601 are set once by the board vendor / manufacturer, and
2602 protects these variables from casual modification by
2603 the user. Once set, these variables are read-only,
2604 and write or delete attempts are rejected. You can
2605 change this behaviour:
2607 If CONFIG_ENV_OVERWRITE is #defined in your config
2608 file, the write protection for vendor parameters is
2609 completely disabled. Anybody can change or delete
2612 Alternatively, if you #define _both_ CONFIG_ETHADDR
2613 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2614 Ethernet address is installed in the environment,
2615 which can be changed exactly ONCE by the user. [The
2616 serial# is unaffected by this, i. e. it remains
2619 The same can be accomplished in a more flexible way
2620 for any variable by configuring the type of access
2621 to allow for those variables in the ".flags" variable
2622 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2627 Define this variable to enable the reservation of
2628 "protected RAM", i. e. RAM which is not overwritten
2629 by U-Boot. Define CONFIG_PRAM to hold the number of
2630 kB you want to reserve for pRAM. You can overwrite
2631 this default value by defining an environment
2632 variable "pram" to the number of kB you want to
2633 reserve. Note that the board info structure will
2634 still show the full amount of RAM. If pRAM is
2635 reserved, a new environment variable "mem" will
2636 automatically be defined to hold the amount of
2637 remaining RAM in a form that can be passed as boot
2638 argument to Linux, for instance like that:
2640 setenv bootargs ... mem=\${mem}
2643 This way you can tell Linux not to use this memory,
2644 either, which results in a memory region that will
2645 not be affected by reboots.
2647 *WARNING* If your board configuration uses automatic
2648 detection of the RAM size, you must make sure that
2649 this memory test is non-destructive. So far, the
2650 following board configurations are known to be
2653 IVMS8, IVML24, SPD8xx, TQM8xxL,
2654 HERMES, IP860, RPXlite, LWMON,
2657 - Access to physical memory region (> 4GB)
2658 Some basic support is provided for operations on memory not
2659 normally accessible to U-Boot - e.g. some architectures
2660 support access to more than 4GB of memory on 32-bit
2661 machines using physical address extension or similar.
2662 Define CONFIG_PHYSMEM to access this basic support, which
2663 currently only supports clearing the memory.
2668 Define this variable to stop the system in case of a
2669 fatal error, so that you have to reset it manually.
2670 This is probably NOT a good idea for an embedded
2671 system where you want the system to reboot
2672 automatically as fast as possible, but it may be
2673 useful during development since you can try to debug
2674 the conditions that lead to the situation.
2676 CONFIG_NET_RETRY_COUNT
2678 This variable defines the number of retries for
2679 network operations like ARP, RARP, TFTP, or BOOTP
2680 before giving up the operation. If not defined, a
2681 default value of 5 is used.
2685 Timeout waiting for an ARP reply in milliseconds.
2689 Timeout in milliseconds used in NFS protocol.
2690 If you encounter "ERROR: Cannot umount" in nfs command,
2691 try longer timeout such as
2692 #define CONFIG_NFS_TIMEOUT 10000UL
2694 - Command Interpreter:
2695 CONFIG_AUTO_COMPLETE
2697 Enable auto completion of commands using TAB.
2699 Note that this feature has NOT been implemented yet
2700 for the "hush" shell.
2703 CONFIG_SYS_HUSH_PARSER
2705 Define this variable to enable the "hush" shell (from
2706 Busybox) as command line interpreter, thus enabling
2707 powerful command line syntax like
2708 if...then...else...fi conditionals or `&&' and '||'
2709 constructs ("shell scripts").
2711 If undefined, you get the old, much simpler behaviour
2712 with a somewhat smaller memory footprint.
2715 CONFIG_SYS_PROMPT_HUSH_PS2
2717 This defines the secondary prompt string, which is
2718 printed when the command interpreter needs more input
2719 to complete a command. Usually "> ".
2723 In the current implementation, the local variables
2724 space and global environment variables space are
2725 separated. Local variables are those you define by
2726 simply typing `name=value'. To access a local
2727 variable later on, you have write `$name' or
2728 `${name}'; to execute the contents of a variable
2729 directly type `$name' at the command prompt.
2731 Global environment variables are those you use
2732 setenv/printenv to work with. To run a command stored
2733 in such a variable, you need to use the run command,
2734 and you must not use the '$' sign to access them.
2736 To store commands and special characters in a
2737 variable, please use double quotation marks
2738 surrounding the whole text of the variable, instead
2739 of the backslashes before semicolons and special
2742 - Commandline Editing and History:
2743 CONFIG_CMDLINE_EDITING
2745 Enable editing and History functions for interactive
2746 commandline input operations
2748 - Default Environment:
2749 CONFIG_EXTRA_ENV_SETTINGS
2751 Define this to contain any number of null terminated
2752 strings (variable = value pairs) that will be part of
2753 the default environment compiled into the boot image.
2755 For example, place something like this in your
2756 board's config file:
2758 #define CONFIG_EXTRA_ENV_SETTINGS \
2762 Warning: This method is based on knowledge about the
2763 internal format how the environment is stored by the
2764 U-Boot code. This is NOT an official, exported
2765 interface! Although it is unlikely that this format
2766 will change soon, there is no guarantee either.
2767 You better know what you are doing here.
2769 Note: overly (ab)use of the default environment is
2770 discouraged. Make sure to check other ways to preset
2771 the environment like the "source" command or the
2774 CONFIG_ENV_VARS_UBOOT_CONFIG
2776 Define this in order to add variables describing the
2777 U-Boot build configuration to the default environment.
2778 These will be named arch, cpu, board, vendor, and soc.
2780 Enabling this option will cause the following to be defined:
2788 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2790 Define this in order to add variables describing certain
2791 run-time determined information about the hardware to the
2792 environment. These will be named board_name, board_rev.
2794 CONFIG_DELAY_ENVIRONMENT
2796 Normally the environment is loaded when the board is
2797 intialised so that it is available to U-Boot. This inhibits
2798 that so that the environment is not available until
2799 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2800 this is instead controlled by the value of
2801 /config/load-environment.
2803 - DataFlash Support:
2804 CONFIG_HAS_DATAFLASH
2806 Defining this option enables DataFlash features and
2807 allows to read/write in Dataflash via the standard
2810 - Serial Flash support
2813 Defining this option enables SPI flash commands
2814 'sf probe/read/write/erase/update'.
2816 Usage requires an initial 'probe' to define the serial
2817 flash parameters, followed by read/write/erase/update
2820 The following defaults may be provided by the platform
2821 to handle the common case when only a single serial
2822 flash is present on the system.
2824 CONFIG_SF_DEFAULT_BUS Bus identifier
2825 CONFIG_SF_DEFAULT_CS Chip-select
2826 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2827 CONFIG_SF_DEFAULT_SPEED in Hz
2831 Define this option to include a destructive SPI flash
2834 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2836 Define this option to use the Bank addr/Extended addr
2837 support on SPI flashes which has size > 16Mbytes.
2839 CONFIG_SF_DUAL_FLASH Dual flash memories
2841 Define this option to use dual flash support where two flash
2842 memories can be connected with a given cs line.
2843 currently Xilinx Zynq qspi support these type of connections.
2845 - SystemACE Support:
2848 Adding this option adds support for Xilinx SystemACE
2849 chips attached via some sort of local bus. The address
2850 of the chip must also be defined in the
2851 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2853 #define CONFIG_SYSTEMACE
2854 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2856 When SystemACE support is added, the "ace" device type
2857 becomes available to the fat commands, i.e. fatls.
2859 - TFTP Fixed UDP Port:
2862 If this is defined, the environment variable tftpsrcp
2863 is used to supply the TFTP UDP source port value.
2864 If tftpsrcp isn't defined, the normal pseudo-random port
2865 number generator is used.
2867 Also, the environment variable tftpdstp is used to supply
2868 the TFTP UDP destination port value. If tftpdstp isn't
2869 defined, the normal port 69 is used.
2871 The purpose for tftpsrcp is to allow a TFTP server to
2872 blindly start the TFTP transfer using the pre-configured
2873 target IP address and UDP port. This has the effect of
2874 "punching through" the (Windows XP) firewall, allowing
2875 the remainder of the TFTP transfer to proceed normally.
2876 A better solution is to properly configure the firewall,
2877 but sometimes that is not allowed.
2882 This enables a generic 'hash' command which can produce
2883 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2887 Enable the hash verify command (hash -v). This adds to code
2890 CONFIG_SHA1 - support SHA1 hashing
2891 CONFIG_SHA256 - support SHA256 hashing
2893 Note: There is also a sha1sum command, which should perhaps
2894 be deprecated in favour of 'hash sha1'.
2896 - Freescale i.MX specific commands:
2897 CONFIG_CMD_HDMIDETECT
2898 This enables 'hdmidet' command which returns true if an
2899 HDMI monitor is detected. This command is i.MX 6 specific.
2902 This enables the 'bmode' (bootmode) command for forcing
2903 a boot from specific media.
2905 This is useful for forcing the ROM's usb downloader to
2906 activate upon a watchdog reset which is nice when iterating
2907 on U-Boot. Using the reset button or running bmode normal
2908 will set it back to normal. This command currently
2909 supports i.MX53 and i.MX6.
2914 This enables the RSA algorithm used for FIT image verification
2915 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2917 The signing part is build into mkimage regardless of this
2920 - bootcount support:
2921 CONFIG_BOOTCOUNT_LIMIT
2923 This enables the bootcounter support, see:
2924 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2927 enable special bootcounter support on at91sam9xe based boards.
2929 enable special bootcounter support on blackfin based boards.
2931 enable special bootcounter support on da850 based boards.
2932 CONFIG_BOOTCOUNT_RAM
2933 enable support for the bootcounter in RAM
2934 CONFIG_BOOTCOUNT_I2C
2935 enable support for the bootcounter on an i2c (like RTC) device.
2936 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2937 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2939 CONFIG_BOOTCOUNT_ALEN = address len
2941 - Show boot progress:
2942 CONFIG_SHOW_BOOT_PROGRESS
2944 Defining this option allows to add some board-
2945 specific code (calling a user-provided function
2946 "show_boot_progress(int)") that enables you to show
2947 the system's boot progress on some display (for
2948 example, some LED's) on your board. At the moment,
2949 the following checkpoints are implemented:
2951 - Detailed boot stage timing
2953 Define this option to get detailed timing of each stage
2954 of the boot process.
2956 CONFIG_BOOTSTAGE_USER_COUNT
2957 This is the number of available user bootstage records.
2958 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2959 a new ID will be allocated from this stash. If you exceed
2960 the limit, recording will stop.
2962 CONFIG_BOOTSTAGE_REPORT
2963 Define this to print a report before boot, similar to this:
2965 Timer summary in microseconds:
2968 3,575,678 3,575,678 board_init_f start
2969 3,575,695 17 arch_cpu_init A9
2970 3,575,777 82 arch_cpu_init done
2971 3,659,598 83,821 board_init_r start
2972 3,910,375 250,777 main_loop
2973 29,916,167 26,005,792 bootm_start
2974 30,361,327 445,160 start_kernel
2976 CONFIG_CMD_BOOTSTAGE
2977 Add a 'bootstage' command which supports printing a report
2978 and un/stashing of bootstage data.
2980 CONFIG_BOOTSTAGE_FDT
2981 Stash the bootstage information in the FDT. A root 'bootstage'
2982 node is created with each bootstage id as a child. Each child
2983 has a 'name' property and either 'mark' containing the
2984 mark time in microsecond, or 'accum' containing the
2985 accumulated time for that bootstage id in microseconds.
2990 name = "board_init_f";
2999 Code in the Linux kernel can find this in /proc/devicetree.
3001 Legacy uImage format:
3004 1 common/cmd_bootm.c before attempting to boot an image
3005 -1 common/cmd_bootm.c Image header has bad magic number
3006 2 common/cmd_bootm.c Image header has correct magic number
3007 -2 common/cmd_bootm.c Image header has bad checksum
3008 3 common/cmd_bootm.c Image header has correct checksum
3009 -3 common/cmd_bootm.c Image data has bad checksum
3010 4 common/cmd_bootm.c Image data has correct checksum
3011 -4 common/cmd_bootm.c Image is for unsupported architecture
3012 5 common/cmd_bootm.c Architecture check OK
3013 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3014 6 common/cmd_bootm.c Image Type check OK
3015 -6 common/cmd_bootm.c gunzip uncompression error
3016 -7 common/cmd_bootm.c Unimplemented compression type
3017 7 common/cmd_bootm.c Uncompression OK
3018 8 common/cmd_bootm.c No uncompress/copy overwrite error
3019 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3021 9 common/image.c Start initial ramdisk verification
3022 -10 common/image.c Ramdisk header has bad magic number
3023 -11 common/image.c Ramdisk header has bad checksum
3024 10 common/image.c Ramdisk header is OK
3025 -12 common/image.c Ramdisk data has bad checksum
3026 11 common/image.c Ramdisk data has correct checksum
3027 12 common/image.c Ramdisk verification complete, start loading
3028 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3029 13 common/image.c Start multifile image verification
3030 14 common/image.c No initial ramdisk, no multifile, continue.
3032 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3034 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3035 -31 post/post.c POST test failed, detected by post_output_backlog()
3036 -32 post/post.c POST test failed, detected by post_run_single()
3038 34 common/cmd_doc.c before loading a Image from a DOC device
3039 -35 common/cmd_doc.c Bad usage of "doc" command
3040 35 common/cmd_doc.c correct usage of "doc" command
3041 -36 common/cmd_doc.c No boot device
3042 36 common/cmd_doc.c correct boot device
3043 -37 common/cmd_doc.c Unknown Chip ID on boot device
3044 37 common/cmd_doc.c correct chip ID found, device available
3045 -38 common/cmd_doc.c Read Error on boot device
3046 38 common/cmd_doc.c reading Image header from DOC device OK
3047 -39 common/cmd_doc.c Image header has bad magic number
3048 39 common/cmd_doc.c Image header has correct magic number
3049 -40 common/cmd_doc.c Error reading Image from DOC device
3050 40 common/cmd_doc.c Image header has correct magic number
3051 41 common/cmd_ide.c before loading a Image from a IDE device
3052 -42 common/cmd_ide.c Bad usage of "ide" command
3053 42 common/cmd_ide.c correct usage of "ide" command
3054 -43 common/cmd_ide.c No boot device
3055 43 common/cmd_ide.c boot device found
3056 -44 common/cmd_ide.c Device not available
3057 44 common/cmd_ide.c Device available
3058 -45 common/cmd_ide.c wrong partition selected
3059 45 common/cmd_ide.c partition selected
3060 -46 common/cmd_ide.c Unknown partition table
3061 46 common/cmd_ide.c valid partition table found
3062 -47 common/cmd_ide.c Invalid partition type
3063 47 common/cmd_ide.c correct partition type
3064 -48 common/cmd_ide.c Error reading Image Header on boot device
3065 48 common/cmd_ide.c reading Image Header from IDE device OK
3066 -49 common/cmd_ide.c Image header has bad magic number
3067 49 common/cmd_ide.c Image header has correct magic number
3068 -50 common/cmd_ide.c Image header has bad checksum
3069 50 common/cmd_ide.c Image header has correct checksum
3070 -51 common/cmd_ide.c Error reading Image from IDE device
3071 51 common/cmd_ide.c reading Image from IDE device OK
3072 52 common/cmd_nand.c before loading a Image from a NAND device
3073 -53 common/cmd_nand.c Bad usage of "nand" command
3074 53 common/cmd_nand.c correct usage of "nand" command
3075 -54 common/cmd_nand.c No boot device
3076 54 common/cmd_nand.c boot device found
3077 -55 common/cmd_nand.c Unknown Chip ID on boot device
3078 55 common/cmd_nand.c correct chip ID found, device available
3079 -56 common/cmd_nand.c Error reading Image Header on boot device
3080 56 common/cmd_nand.c reading Image Header from NAND device OK
3081 -57 common/cmd_nand.c Image header has bad magic number
3082 57 common/cmd_nand.c Image header has correct magic number
3083 -58 common/cmd_nand.c Error reading Image from NAND device
3084 58 common/cmd_nand.c reading Image from NAND device OK
3086 -60 common/env_common.c Environment has a bad CRC, using default
3088 64 net/eth.c starting with Ethernet configuration.
3089 -64 net/eth.c no Ethernet found.
3090 65 net/eth.c Ethernet found.
3092 -80 common/cmd_net.c usage wrong
3093 80 common/cmd_net.c before calling NetLoop()
3094 -81 common/cmd_net.c some error in NetLoop() occurred
3095 81 common/cmd_net.c NetLoop() back without error
3096 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3097 82 common/cmd_net.c trying automatic boot
3098 83 common/cmd_net.c running "source" command
3099 -83 common/cmd_net.c some error in automatic boot or "source" command
3100 84 common/cmd_net.c end without errors
3105 100 common/cmd_bootm.c Kernel FIT Image has correct format
3106 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3107 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3108 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3109 102 common/cmd_bootm.c Kernel unit name specified
3110 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3111 103 common/cmd_bootm.c Found configuration node
3112 104 common/cmd_bootm.c Got kernel subimage node offset
3113 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3114 105 common/cmd_bootm.c Kernel subimage hash verification OK
3115 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3116 106 common/cmd_bootm.c Architecture check OK
3117 -106 common/cmd_bootm.c Kernel subimage has wrong type
3118 107 common/cmd_bootm.c Kernel subimage type OK
3119 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3120 108 common/cmd_bootm.c Got kernel subimage data/size
3121 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3122 -109 common/cmd_bootm.c Can't get kernel subimage type
3123 -110 common/cmd_bootm.c Can't get kernel subimage comp
3124 -111 common/cmd_bootm.c Can't get kernel subimage os
3125 -112 common/cmd_bootm.c Can't get kernel subimage load address
3126 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3128 120 common/image.c Start initial ramdisk verification
3129 -120 common/image.c Ramdisk FIT image has incorrect format
3130 121 common/image.c Ramdisk FIT image has correct format
3131 122 common/image.c No ramdisk subimage unit name, using configuration
3132 -122 common/image.c Can't get configuration for ramdisk subimage
3133 123 common/image.c Ramdisk unit name specified
3134 -124 common/image.c Can't get ramdisk subimage node offset
3135 125 common/image.c Got ramdisk subimage node offset
3136 -125 common/image.c Ramdisk subimage hash verification failed
3137 126 common/image.c Ramdisk subimage hash verification OK
3138 -126 common/image.c Ramdisk subimage for unsupported architecture
3139 127 common/image.c Architecture check OK
3140 -127 common/image.c Can't get ramdisk subimage data/size
3141 128 common/image.c Got ramdisk subimage data/size
3142 129 common/image.c Can't get ramdisk load address
3143 -129 common/image.c Got ramdisk load address
3145 -130 common/cmd_doc.c Incorrect FIT image format
3146 131 common/cmd_doc.c FIT image format OK
3148 -140 common/cmd_ide.c Incorrect FIT image format
3149 141 common/cmd_ide.c FIT image format OK
3151 -150 common/cmd_nand.c Incorrect FIT image format
3152 151 common/cmd_nand.c FIT image format OK
3154 - FIT image support:
3156 Enable support for the FIT uImage format.
3158 CONFIG_FIT_BEST_MATCH
3159 When no configuration is explicitly selected, default to the
3160 one whose fdt's compatibility field best matches that of
3161 U-Boot itself. A match is considered "best" if it matches the
3162 most specific compatibility entry of U-Boot's fdt's root node.
3163 The order of entries in the configuration's fdt is ignored.
3165 CONFIG_FIT_SIGNATURE
3166 This option enables signature verification of FIT uImages,
3167 using a hash signed and verified using RSA. See
3168 doc/uImage.FIT/signature.txt for more details.
3170 - Standalone program support:
3171 CONFIG_STANDALONE_LOAD_ADDR
3173 This option defines a board specific value for the
3174 address where standalone program gets loaded, thus
3175 overwriting the architecture dependent default
3178 - Frame Buffer Address:
3181 Define CONFIG_FB_ADDR if you want to use specific
3182 address for frame buffer. This is typically the case
3183 when using a graphics controller has separate video
3184 memory. U-Boot will then place the frame buffer at
3185 the given address instead of dynamically reserving it
3186 in system RAM by calling lcd_setmem(), which grabs
3187 the memory for the frame buffer depending on the
3188 configured panel size.
3190 Please see board_init_f function.
3192 - Automatic software updates via TFTP server
3194 CONFIG_UPDATE_TFTP_CNT_MAX
3195 CONFIG_UPDATE_TFTP_MSEC_MAX
3197 These options enable and control the auto-update feature;
3198 for a more detailed description refer to doc/README.update.
3200 - MTD Support (mtdparts command, UBI support)
3203 Adds the MTD device infrastructure from the Linux kernel.
3204 Needed for mtdparts command support.
3206 CONFIG_MTD_PARTITIONS
3208 Adds the MTD partitioning infrastructure from the Linux
3209 kernel. Needed for UBI support.
3214 Adds commands for interacting with MTD partitions formatted
3215 with the UBI flash translation layer
3217 Requires also defining CONFIG_RBTREE
3219 CONFIG_UBI_SILENCE_MSG
3221 Make the verbose messages from UBI stop printing. This leaves
3222 warnings and errors enabled.
3227 Adds commands for interacting with UBI volumes formatted as
3228 UBIFS. UBIFS is read-only in u-boot.
3230 Requires UBI support as well as CONFIG_LZO
3232 CONFIG_UBIFS_SILENCE_MSG
3234 Make the verbose messages from UBIFS stop printing. This leaves
3235 warnings and errors enabled.
3239 Enable building of SPL globally.
3242 LDSCRIPT for linking the SPL binary.
3244 CONFIG_SPL_MAX_FOOTPRINT
3245 Maximum size in memory allocated to the SPL, BSS included.
3246 When defined, the linker checks that the actual memory
3247 used by SPL from _start to __bss_end does not exceed it.
3248 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3249 must not be both defined at the same time.
3252 Maximum size of the SPL image (text, data, rodata, and
3253 linker lists sections), BSS excluded.
3254 When defined, the linker checks that the actual size does
3257 CONFIG_SPL_TEXT_BASE
3258 TEXT_BASE for linking the SPL binary.
3260 CONFIG_SPL_RELOC_TEXT_BASE
3261 Address to relocate to. If unspecified, this is equal to
3262 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3264 CONFIG_SPL_BSS_START_ADDR
3265 Link address for the BSS within the SPL binary.
3267 CONFIG_SPL_BSS_MAX_SIZE
3268 Maximum size in memory allocated to the SPL BSS.
3269 When defined, the linker checks that the actual memory used
3270 by SPL from __bss_start to __bss_end does not exceed it.
3271 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3272 must not be both defined at the same time.
3275 Adress of the start of the stack SPL will use
3277 CONFIG_SPL_RELOC_STACK
3278 Adress of the start of the stack SPL will use after
3279 relocation. If unspecified, this is equal to
3282 CONFIG_SYS_SPL_MALLOC_START
3283 Starting address of the malloc pool used in SPL.
3285 CONFIG_SYS_SPL_MALLOC_SIZE
3286 The size of the malloc pool used in SPL.
3288 CONFIG_SPL_FRAMEWORK
3289 Enable the SPL framework under common/. This framework
3290 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3291 NAND loading of the Linux Kernel.
3294 Enable booting directly to an OS from SPL.
3295 See also: doc/README.falcon
3297 CONFIG_SPL_DISPLAY_PRINT
3298 For ARM, enable an optional function to print more information
3299 about the running system.
3301 CONFIG_SPL_INIT_MINIMAL
3302 Arch init code should be built for a very small image
3304 CONFIG_SPL_LIBCOMMON_SUPPORT
3305 Support for common/libcommon.o in SPL binary
3307 CONFIG_SPL_LIBDISK_SUPPORT
3308 Support for disk/libdisk.o in SPL binary
3310 CONFIG_SPL_I2C_SUPPORT
3311 Support for drivers/i2c/libi2c.o in SPL binary
3313 CONFIG_SPL_GPIO_SUPPORT
3314 Support for drivers/gpio/libgpio.o in SPL binary
3316 CONFIG_SPL_MMC_SUPPORT
3317 Support for drivers/mmc/libmmc.o in SPL binary
3319 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3320 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3321 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3322 Address, size and partition on the MMC to load U-Boot from
3323 when the MMC is being used in raw mode.
3325 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3326 Sector to load kernel uImage from when MMC is being
3327 used in raw mode (for Falcon mode)
3329 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3330 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3331 Sector and number of sectors to load kernel argument
3332 parameters from when MMC is being used in raw mode
3335 CONFIG_SPL_FAT_SUPPORT
3336 Support for fs/fat/libfat.o in SPL binary
3338 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3339 Filename to read to load U-Boot when reading from FAT
3341 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3342 Filename to read to load kernel uImage when reading
3343 from FAT (for Falcon mode)
3345 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3346 Filename to read to load kernel argument parameters
3347 when reading from FAT (for Falcon mode)
3349 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3350 Set this for NAND SPL on PPC mpc83xx targets, so that
3351 start.S waits for the rest of the SPL to load before
3352 continuing (the hardware starts execution after just
3353 loading the first page rather than the full 4K).
3355 CONFIG_SPL_SKIP_RELOCATE
3356 Avoid SPL relocation
3358 CONFIG_SPL_NAND_BASE
3359 Include nand_base.c in the SPL. Requires
3360 CONFIG_SPL_NAND_DRIVERS.
3362 CONFIG_SPL_NAND_DRIVERS
3363 SPL uses normal NAND drivers, not minimal drivers.
3366 Include standard software ECC in the SPL
3368 CONFIG_SPL_NAND_SIMPLE
3369 Support for NAND boot using simple NAND drivers that
3370 expose the cmd_ctrl() interface.
3372 CONFIG_SPL_MTD_SUPPORT
3373 Support for the MTD subsystem within SPL. Useful for
3374 environment on NAND support within SPL.
3376 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3377 Set for the SPL on PPC mpc8xxx targets, support for
3378 drivers/ddr/fsl/libddr.o in SPL binary.
3380 CONFIG_SPL_COMMON_INIT_DDR
3381 Set for common ddr init with serial presence detect in
3384 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3385 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3386 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3387 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3388 CONFIG_SYS_NAND_ECCBYTES
3389 Defines the size and behavior of the NAND that SPL uses
3392 CONFIG_SPL_NAND_BOOT
3393 Add support NAND boot
3395 CONFIG_SYS_NAND_U_BOOT_OFFS
3396 Location in NAND to read U-Boot from
3398 CONFIG_SYS_NAND_U_BOOT_DST
3399 Location in memory to load U-Boot to
3401 CONFIG_SYS_NAND_U_BOOT_SIZE
3402 Size of image to load
3404 CONFIG_SYS_NAND_U_BOOT_START
3405 Entry point in loaded image to jump to
3407 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3408 Define this if you need to first read the OOB and then the
3409 data. This is used for example on davinci plattforms.
3411 CONFIG_SPL_OMAP3_ID_NAND
3412 Support for an OMAP3-specific set of functions to return the
3413 ID and MFR of the first attached NAND chip, if present.
3415 CONFIG_SPL_SERIAL_SUPPORT
3416 Support for drivers/serial/libserial.o in SPL binary
3418 CONFIG_SPL_SPI_FLASH_SUPPORT
3419 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3421 CONFIG_SPL_SPI_SUPPORT
3422 Support for drivers/spi/libspi.o in SPL binary
3424 CONFIG_SPL_RAM_DEVICE
3425 Support for running image already present in ram, in SPL binary
3427 CONFIG_SPL_LIBGENERIC_SUPPORT
3428 Support for lib/libgeneric.o in SPL binary
3430 CONFIG_SPL_ENV_SUPPORT
3431 Support for the environment operating in SPL binary
3433 CONFIG_SPL_NET_SUPPORT
3434 Support for the net/libnet.o in SPL binary.
3435 It conflicts with SPL env from storage medium specified by
3436 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3439 Image offset to which the SPL should be padded before appending
3440 the SPL payload. By default, this is defined as
3441 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3442 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3443 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3446 Final target image containing SPL and payload. Some SPLs
3447 use an arch-specific makefile fragment instead, for
3448 example if more than one image needs to be produced.
3450 CONFIG_FIT_SPL_PRINT
3451 Printing information about a FIT image adds quite a bit of
3452 code to SPL. So this is normally disabled in SPL. Use this
3453 option to re-enable it. This will affect the output of the
3454 bootm command when booting a FIT image.
3458 Enable building of TPL globally.
3461 Image offset to which the TPL should be padded before appending
3462 the TPL payload. By default, this is defined as
3463 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3464 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3465 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3470 [so far only for SMDK2400 boards]
3472 - Modem support enable:
3473 CONFIG_MODEM_SUPPORT
3475 - RTS/CTS Flow control enable:
3478 - Modem debug support:
3479 CONFIG_MODEM_SUPPORT_DEBUG
3481 Enables debugging stuff (char screen[1024], dbg())
3482 for modem support. Useful only with BDI2000.
3484 - Interrupt support (PPC):
3486 There are common interrupt_init() and timer_interrupt()
3487 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3488 for CPU specific initialization. interrupt_init_cpu()
3489 should set decrementer_count to appropriate value. If
3490 CPU resets decrementer automatically after interrupt
3491 (ppc4xx) it should set decrementer_count to zero.
3492 timer_interrupt() calls timer_interrupt_cpu() for CPU
3493 specific handling. If board has watchdog / status_led
3494 / other_activity_monitor it works automatically from
3495 general timer_interrupt().
3499 In the target system modem support is enabled when a
3500 specific key (key combination) is pressed during
3501 power-on. Otherwise U-Boot will boot normally
3502 (autoboot). The key_pressed() function is called from
3503 board_init(). Currently key_pressed() is a dummy
3504 function, returning 1 and thus enabling modem
3507 If there are no modem init strings in the
3508 environment, U-Boot proceed to autoboot; the
3509 previous output (banner, info printfs) will be
3512 See also: doc/README.Modem
3514 Board initialization settings:
3515 ------------------------------
3517 During Initialization u-boot calls a number of board specific functions
3518 to allow the preparation of board specific prerequisites, e.g. pin setup
3519 before drivers are initialized. To enable these callbacks the
3520 following configuration macros have to be defined. Currently this is
3521 architecture specific, so please check arch/your_architecture/lib/board.c
3522 typically in board_init_f() and board_init_r().
3524 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3525 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3526 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3527 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3529 Configuration Settings:
3530 -----------------------
3532 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3533 Optionally it can be defined to support 64-bit memory commands.
3535 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3536 undefine this when you're short of memory.
3538 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3539 width of the commands listed in the 'help' command output.
3541 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3542 prompt for user input.
3544 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3546 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3548 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3550 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3551 the application (usually a Linux kernel) when it is
3554 - CONFIG_SYS_BAUDRATE_TABLE:
3555 List of legal baudrate settings for this board.
3557 - CONFIG_SYS_CONSOLE_INFO_QUIET
3558 Suppress display of console information at boot.
3560 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3561 If the board specific function
3562 extern int overwrite_console (void);
3563 returns 1, the stdin, stderr and stdout are switched to the
3564 serial port, else the settings in the environment are used.
3566 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3567 Enable the call to overwrite_console().
3569 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3570 Enable overwrite of previous console environment settings.
3572 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3573 Begin and End addresses of the area used by the
3576 - CONFIG_SYS_ALT_MEMTEST:
3577 Enable an alternate, more extensive memory test.
3579 - CONFIG_SYS_MEMTEST_SCRATCH:
3580 Scratch address used by the alternate memory test
3581 You only need to set this if address zero isn't writeable
3583 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3584 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3585 this specified memory area will get subtracted from the top
3586 (end) of RAM and won't get "touched" at all by U-Boot. By
3587 fixing up gd->ram_size the Linux kernel should gets passed
3588 the now "corrected" memory size and won't touch it either.
3589 This should work for arch/ppc and arch/powerpc. Only Linux
3590 board ports in arch/powerpc with bootwrapper support that
3591 recalculate the memory size from the SDRAM controller setup
3592 will have to get fixed in Linux additionally.
3594 This option can be used as a workaround for the 440EPx/GRx
3595 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3598 WARNING: Please make sure that this value is a multiple of
3599 the Linux page size (normally 4k). If this is not the case,
3600 then the end address of the Linux memory will be located at a
3601 non page size aligned address and this could cause major
3604 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3605 Enable temporary baudrate change while serial download
3607 - CONFIG_SYS_SDRAM_BASE:
3608 Physical start address of SDRAM. _Must_ be 0 here.
3610 - CONFIG_SYS_MBIO_BASE:
3611 Physical start address of Motherboard I/O (if using a
3614 - CONFIG_SYS_FLASH_BASE:
3615 Physical start address of Flash memory.
3617 - CONFIG_SYS_MONITOR_BASE:
3618 Physical start address of boot monitor code (set by
3619 make config files to be same as the text base address
3620 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3621 CONFIG_SYS_FLASH_BASE when booting from flash.
3623 - CONFIG_SYS_MONITOR_LEN:
3624 Size of memory reserved for monitor code, used to
3625 determine _at_compile_time_ (!) if the environment is
3626 embedded within the U-Boot image, or in a separate
3629 - CONFIG_SYS_MALLOC_LEN:
3630 Size of DRAM reserved for malloc() use.
3632 - CONFIG_SYS_BOOTM_LEN:
3633 Normally compressed uImages are limited to an
3634 uncompressed size of 8 MBytes. If this is not enough,
3635 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3636 to adjust this setting to your needs.
3638 - CONFIG_SYS_BOOTMAPSZ:
3639 Maximum size of memory mapped by the startup code of
3640 the Linux kernel; all data that must be processed by
3641 the Linux kernel (bd_info, boot arguments, FDT blob if
3642 used) must be put below this limit, unless "bootm_low"
3643 environment variable is defined and non-zero. In such case
3644 all data for the Linux kernel must be between "bootm_low"
3645 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3646 variable "bootm_mapsize" will override the value of
3647 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3648 then the value in "bootm_size" will be used instead.
3650 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3651 Enable initrd_high functionality. If defined then the
3652 initrd_high feature is enabled and the bootm ramdisk subcommand
3655 - CONFIG_SYS_BOOT_GET_CMDLINE:
3656 Enables allocating and saving kernel cmdline in space between
3657 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3659 - CONFIG_SYS_BOOT_GET_KBD:
3660 Enables allocating and saving a kernel copy of the bd_info in
3661 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3663 - CONFIG_SYS_MAX_FLASH_BANKS:
3664 Max number of Flash memory banks
3666 - CONFIG_SYS_MAX_FLASH_SECT:
3667 Max number of sectors on a Flash chip
3669 - CONFIG_SYS_FLASH_ERASE_TOUT:
3670 Timeout for Flash erase operations (in ms)
3672 - CONFIG_SYS_FLASH_WRITE_TOUT:
3673 Timeout for Flash write operations (in ms)
3675 - CONFIG_SYS_FLASH_LOCK_TOUT
3676 Timeout for Flash set sector lock bit operation (in ms)
3678 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3679 Timeout for Flash clear lock bits operation (in ms)
3681 - CONFIG_SYS_FLASH_PROTECTION
3682 If defined, hardware flash sectors protection is used
3683 instead of U-Boot software protection.
3685 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3687 Enable TFTP transfers directly to flash memory;
3688 without this option such a download has to be
3689 performed in two steps: (1) download to RAM, and (2)
3690 copy from RAM to flash.
3692 The two-step approach is usually more reliable, since
3693 you can check if the download worked before you erase
3694 the flash, but in some situations (when system RAM is
3695 too limited to allow for a temporary copy of the
3696 downloaded image) this option may be very useful.
3698 - CONFIG_SYS_FLASH_CFI:
3699 Define if the flash driver uses extra elements in the
3700 common flash structure for storing flash geometry.
3702 - CONFIG_FLASH_CFI_DRIVER
3703 This option also enables the building of the cfi_flash driver
3704 in the drivers directory
3706 - CONFIG_FLASH_CFI_MTD
3707 This option enables the building of the cfi_mtd driver
3708 in the drivers directory. The driver exports CFI flash
3711 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3712 Use buffered writes to flash.
3714 - CONFIG_FLASH_SPANSION_S29WS_N
3715 s29ws-n MirrorBit flash has non-standard addresses for buffered
3718 - CONFIG_SYS_FLASH_QUIET_TEST
3719 If this option is defined, the common CFI flash doesn't
3720 print it's warning upon not recognized FLASH banks. This
3721 is useful, if some of the configured banks are only
3722 optionally available.
3724 - CONFIG_FLASH_SHOW_PROGRESS
3725 If defined (must be an integer), print out countdown
3726 digits and dots. Recommended value: 45 (9..1) for 80
3727 column displays, 15 (3..1) for 40 column displays.
3729 - CONFIG_FLASH_VERIFY
3730 If defined, the content of the flash (destination) is compared
3731 against the source after the write operation. An error message
3732 will be printed when the contents are not identical.
3733 Please note that this option is useless in nearly all cases,
3734 since such flash programming errors usually are detected earlier
3735 while unprotecting/erasing/programming. Please only enable
3736 this option if you really know what you are doing.
3738 - CONFIG_SYS_RX_ETH_BUFFER:
3739 Defines the number of Ethernet receive buffers. On some
3740 Ethernet controllers it is recommended to set this value
3741 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3742 buffers can be full shortly after enabling the interface
3743 on high Ethernet traffic.
3744 Defaults to 4 if not defined.
3746 - CONFIG_ENV_MAX_ENTRIES
3748 Maximum number of entries in the hash table that is used
3749 internally to store the environment settings. The default
3750 setting is supposed to be generous and should work in most
3751 cases. This setting can be used to tune behaviour; see
3752 lib/hashtable.c for details.
3754 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3755 - CONFIG_ENV_FLAGS_LIST_STATIC
3756 Enable validation of the values given to environment variables when
3757 calling env set. Variables can be restricted to only decimal,
3758 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3759 the variables can also be restricted to IP address or MAC address.
3761 The format of the list is:
3762 type_attribute = [s|d|x|b|i|m]
3763 access_atribute = [a|r|o|c]
3764 attributes = type_attribute[access_atribute]
3765 entry = variable_name[:attributes]
3768 The type attributes are:
3769 s - String (default)
3772 b - Boolean ([1yYtT|0nNfF])
3776 The access attributes are:
3782 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3783 Define this to a list (string) to define the ".flags"
3784 envirnoment variable in the default or embedded environment.
3786 - CONFIG_ENV_FLAGS_LIST_STATIC
3787 Define this to a list (string) to define validation that
3788 should be done if an entry is not found in the ".flags"
3789 environment variable. To override a setting in the static
3790 list, simply add an entry for the same variable name to the
3793 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3794 If defined, don't allow the -f switch to env set override variable
3797 - CONFIG_SYS_GENERIC_BOARD
3798 This selects the architecture-generic board system instead of the
3799 architecture-specific board files. It is intended to move boards
3800 to this new framework over time. Defining this will disable the
3801 arch/foo/lib/board.c file and use common/board_f.c and
3802 common/board_r.c instead. To use this option your architecture
3803 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3804 its config.mk file). If you find problems enabling this option on
3805 your board please report the problem and send patches!
3807 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3808 This is set by OMAP boards for the max time that reset should
3809 be asserted. See doc/README.omap-reset-time for details on how
3810 the value can be calulated on a given board.
3812 The following definitions that deal with the placement and management
3813 of environment data (variable area); in general, we support the
3814 following configurations:
3816 - CONFIG_BUILD_ENVCRC:
3818 Builds up envcrc with the target environment so that external utils
3819 may easily extract it and embed it in final U-Boot images.
3821 - CONFIG_ENV_IS_IN_FLASH:
3823 Define this if the environment is in flash memory.
3825 a) The environment occupies one whole flash sector, which is
3826 "embedded" in the text segment with the U-Boot code. This
3827 happens usually with "bottom boot sector" or "top boot
3828 sector" type flash chips, which have several smaller
3829 sectors at the start or the end. For instance, such a
3830 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3831 such a case you would place the environment in one of the
3832 4 kB sectors - with U-Boot code before and after it. With
3833 "top boot sector" type flash chips, you would put the
3834 environment in one of the last sectors, leaving a gap
3835 between U-Boot and the environment.
3837 - CONFIG_ENV_OFFSET:
3839 Offset of environment data (variable area) to the
3840 beginning of flash memory; for instance, with bottom boot
3841 type flash chips the second sector can be used: the offset
3842 for this sector is given here.
3844 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3848 This is just another way to specify the start address of
3849 the flash sector containing the environment (instead of
3852 - CONFIG_ENV_SECT_SIZE:
3854 Size of the sector containing the environment.
3857 b) Sometimes flash chips have few, equal sized, BIG sectors.
3858 In such a case you don't want to spend a whole sector for
3863 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3864 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3865 of this flash sector for the environment. This saves
3866 memory for the RAM copy of the environment.
3868 It may also save flash memory if you decide to use this
3869 when your environment is "embedded" within U-Boot code,
3870 since then the remainder of the flash sector could be used
3871 for U-Boot code. It should be pointed out that this is
3872 STRONGLY DISCOURAGED from a robustness point of view:
3873 updating the environment in flash makes it always
3874 necessary to erase the WHOLE sector. If something goes
3875 wrong before the contents has been restored from a copy in
3876 RAM, your target system will be dead.
3878 - CONFIG_ENV_ADDR_REDUND
3879 CONFIG_ENV_SIZE_REDUND
3881 These settings describe a second storage area used to hold
3882 a redundant copy of the environment data, so that there is
3883 a valid backup copy in case there is a power failure during
3884 a "saveenv" operation.
3886 BE CAREFUL! Any changes to the flash layout, and some changes to the
3887 source code will make it necessary to adapt <board>/u-boot.lds*
3891 - CONFIG_ENV_IS_IN_NVRAM:
3893 Define this if you have some non-volatile memory device
3894 (NVRAM, battery buffered SRAM) which you want to use for the
3900 These two #defines are used to determine the memory area you
3901 want to use for environment. It is assumed that this memory
3902 can just be read and written to, without any special
3905 BE CAREFUL! The first access to the environment happens quite early
3906 in U-Boot initalization (when we try to get the setting of for the
3907 console baudrate). You *MUST* have mapped your NVRAM area then, or
3910 Please note that even with NVRAM we still use a copy of the
3911 environment in RAM: we could work on NVRAM directly, but we want to
3912 keep settings there always unmodified except somebody uses "saveenv"
3913 to save the current settings.
3916 - CONFIG_ENV_IS_IN_EEPROM:
3918 Use this if you have an EEPROM or similar serial access
3919 device and a driver for it.
3921 - CONFIG_ENV_OFFSET:
3924 These two #defines specify the offset and size of the
3925 environment area within the total memory of your EEPROM.
3927 - CONFIG_SYS_I2C_EEPROM_ADDR:
3928 If defined, specified the chip address of the EEPROM device.
3929 The default address is zero.
3931 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3932 If defined, the number of bits used to address bytes in a
3933 single page in the EEPROM device. A 64 byte page, for example
3934 would require six bits.
3936 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3937 If defined, the number of milliseconds to delay between
3938 page writes. The default is zero milliseconds.
3940 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3941 The length in bytes of the EEPROM memory array address. Note
3942 that this is NOT the chip address length!
3944 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3945 EEPROM chips that implement "address overflow" are ones
3946 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3947 address and the extra bits end up in the "chip address" bit
3948 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3951 Note that we consider the length of the address field to
3952 still be one byte because the extra address bits are hidden
3953 in the chip address.
3955 - CONFIG_SYS_EEPROM_SIZE:
3956 The size in bytes of the EEPROM device.
3958 - CONFIG_ENV_EEPROM_IS_ON_I2C
3959 define this, if you have I2C and SPI activated, and your
3960 EEPROM, which holds the environment, is on the I2C bus.
3962 - CONFIG_I2C_ENV_EEPROM_BUS
3963 if you have an Environment on an EEPROM reached over
3964 I2C muxes, you can define here, how to reach this
3965 EEPROM. For example:
3967 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3969 EEPROM which holds the environment, is reached over
3970 a pca9547 i2c mux with address 0x70, channel 3.
3972 - CONFIG_ENV_IS_IN_DATAFLASH:
3974 Define this if you have a DataFlash memory device which you
3975 want to use for the environment.
3977 - CONFIG_ENV_OFFSET:
3981 These three #defines specify the offset and size of the
3982 environment area within the total memory of your DataFlash placed
3983 at the specified address.
3985 - CONFIG_ENV_IS_IN_REMOTE:
3987 Define this if you have a remote memory space which you
3988 want to use for the local device's environment.
3993 These two #defines specify the address and size of the
3994 environment area within the remote memory space. The
3995 local device can get the environment from remote memory
3996 space by SRIO or PCIE links.
3998 BE CAREFUL! For some special cases, the local device can not use
3999 "saveenv" command. For example, the local device will get the
4000 environment stored in a remote NOR flash by SRIO or PCIE link,
4001 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4003 - CONFIG_ENV_IS_IN_NAND:
4005 Define this if you have a NAND device which you want to use
4006 for the environment.
4008 - CONFIG_ENV_OFFSET:
4011 These two #defines specify the offset and size of the environment
4012 area within the first NAND device. CONFIG_ENV_OFFSET must be
4013 aligned to an erase block boundary.
4015 - CONFIG_ENV_OFFSET_REDUND (optional):
4017 This setting describes a second storage area of CONFIG_ENV_SIZE
4018 size used to hold a redundant copy of the environment data, so
4019 that there is a valid backup copy in case there is a power failure
4020 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4021 aligned to an erase block boundary.
4023 - CONFIG_ENV_RANGE (optional):
4025 Specifies the length of the region in which the environment
4026 can be written. This should be a multiple of the NAND device's
4027 block size. Specifying a range with more erase blocks than
4028 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4029 the range to be avoided.
4031 - CONFIG_ENV_OFFSET_OOB (optional):
4033 Enables support for dynamically retrieving the offset of the
4034 environment from block zero's out-of-band data. The
4035 "nand env.oob" command can be used to record this offset.
4036 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4037 using CONFIG_ENV_OFFSET_OOB.
4039 - CONFIG_NAND_ENV_DST
4041 Defines address in RAM to which the nand_spl code should copy the
4042 environment. If redundant environment is used, it will be copied to
4043 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4045 - CONFIG_ENV_IS_IN_UBI:
4047 Define this if you have an UBI volume that you want to use for the
4048 environment. This has the benefit of wear-leveling the environment
4049 accesses, which is important on NAND.
4051 - CONFIG_ENV_UBI_PART:
4053 Define this to a string that is the mtd partition containing the UBI.
4055 - CONFIG_ENV_UBI_VOLUME:
4057 Define this to the name of the volume that you want to store the
4060 - CONFIG_ENV_UBI_VOLUME_REDUND:
4062 Define this to the name of another volume to store a second copy of
4063 the environment in. This will enable redundant environments in UBI.
4064 It is assumed that both volumes are in the same MTD partition.
4066 - CONFIG_UBI_SILENCE_MSG
4067 - CONFIG_UBIFS_SILENCE_MSG
4069 You will probably want to define these to avoid a really noisy system
4070 when storing the env in UBI.
4072 - CONFIG_ENV_IS_IN_MMC:
4074 Define this if you have an MMC device which you want to use for the
4077 - CONFIG_SYS_MMC_ENV_DEV:
4079 Specifies which MMC device the environment is stored in.
4081 - CONFIG_SYS_MMC_ENV_PART (optional):
4083 Specifies which MMC partition the environment is stored in. If not
4084 set, defaults to partition 0, the user area. Common values might be
4085 1 (first MMC boot partition), 2 (second MMC boot partition).
4087 - CONFIG_ENV_OFFSET:
4090 These two #defines specify the offset and size of the environment
4091 area within the specified MMC device.
4093 If offset is positive (the usual case), it is treated as relative to
4094 the start of the MMC partition. If offset is negative, it is treated
4095 as relative to the end of the MMC partition. This can be useful if
4096 your board may be fitted with different MMC devices, which have
4097 different sizes for the MMC partitions, and you always want the
4098 environment placed at the very end of the partition, to leave the
4099 maximum possible space before it, to store other data.
4101 These two values are in units of bytes, but must be aligned to an
4102 MMC sector boundary.
4104 - CONFIG_ENV_OFFSET_REDUND (optional):
4106 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4107 hold a redundant copy of the environment data. This provides a
4108 valid backup copy in case the other copy is corrupted, e.g. due
4109 to a power failure during a "saveenv" operation.
4111 This value may also be positive or negative; this is handled in the
4112 same way as CONFIG_ENV_OFFSET.
4114 This value is also in units of bytes, but must also be aligned to
4115 an MMC sector boundary.
4117 - CONFIG_ENV_SIZE_REDUND (optional):
4119 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4120 set. If this value is set, it must be set to the same value as
4123 - CONFIG_SYS_SPI_INIT_OFFSET
4125 Defines offset to the initial SPI buffer area in DPRAM. The
4126 area is used at an early stage (ROM part) if the environment
4127 is configured to reside in the SPI EEPROM: We need a 520 byte
4128 scratch DPRAM area. It is used between the two initialization
4129 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4130 to be a good choice since it makes it far enough from the
4131 start of the data area as well as from the stack pointer.
4133 Please note that the environment is read-only until the monitor
4134 has been relocated to RAM and a RAM copy of the environment has been
4135 created; also, when using EEPROM you will have to use getenv_f()
4136 until then to read environment variables.
4138 The environment is protected by a CRC32 checksum. Before the monitor
4139 is relocated into RAM, as a result of a bad CRC you will be working
4140 with the compiled-in default environment - *silently*!!! [This is
4141 necessary, because the first environment variable we need is the
4142 "baudrate" setting for the console - if we have a bad CRC, we don't
4143 have any device yet where we could complain.]
4145 Note: once the monitor has been relocated, then it will complain if
4146 the default environment is used; a new CRC is computed as soon as you
4147 use the "saveenv" command to store a valid environment.
4149 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4150 Echo the inverted Ethernet link state to the fault LED.
4152 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4153 also needs to be defined.
4155 - CONFIG_SYS_FAULT_MII_ADDR:
4156 MII address of the PHY to check for the Ethernet link state.
4158 - CONFIG_NS16550_MIN_FUNCTIONS:
4159 Define this if you desire to only have use of the NS16550_init
4160 and NS16550_putc functions for the serial driver located at
4161 drivers/serial/ns16550.c. This option is useful for saving
4162 space for already greatly restricted images, including but not
4163 limited to NAND_SPL configurations.
4165 - CONFIG_DISPLAY_BOARDINFO
4166 Display information about the board that U-Boot is running on
4167 when U-Boot starts up. The board function checkboard() is called
4170 - CONFIG_DISPLAY_BOARDINFO_LATE
4171 Similar to the previous option, but display this information
4172 later, once stdio is running and output goes to the LCD, if
4175 Low Level (hardware related) configuration options:
4176 ---------------------------------------------------
4178 - CONFIG_SYS_CACHELINE_SIZE:
4179 Cache Line Size of the CPU.
4181 - CONFIG_SYS_DEFAULT_IMMR:
4182 Default address of the IMMR after system reset.
4184 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4185 and RPXsuper) to be able to adjust the position of
4186 the IMMR register after a reset.
4188 - CONFIG_SYS_CCSRBAR_DEFAULT:
4189 Default (power-on reset) physical address of CCSR on Freescale
4192 - CONFIG_SYS_CCSRBAR:
4193 Virtual address of CCSR. On a 32-bit build, this is typically
4194 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4196 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4197 for cross-platform code that uses that macro instead.
4199 - CONFIG_SYS_CCSRBAR_PHYS:
4200 Physical address of CCSR. CCSR can be relocated to a new
4201 physical address, if desired. In this case, this macro should
4202 be set to that address. Otherwise, it should be set to the
4203 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4204 is typically relocated on 36-bit builds. It is recommended
4205 that this macro be defined via the _HIGH and _LOW macros:
4207 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4208 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4210 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4211 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4212 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4213 used in assembly code, so it must not contain typecasts or
4214 integer size suffixes (e.g. "ULL").
4216 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4217 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4218 used in assembly code, so it must not contain typecasts or
4219 integer size suffixes (e.g. "ULL").
4221 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4222 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4223 forced to a value that ensures that CCSR is not relocated.
4225 - Floppy Disk Support:
4226 CONFIG_SYS_FDC_DRIVE_NUMBER
4228 the default drive number (default value 0)
4230 CONFIG_SYS_ISA_IO_STRIDE
4232 defines the spacing between FDC chipset registers
4235 CONFIG_SYS_ISA_IO_OFFSET
4237 defines the offset of register from address. It
4238 depends on which part of the data bus is connected to
4239 the FDC chipset. (default value 0)
4241 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4242 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4245 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4246 fdc_hw_init() is called at the beginning of the FDC
4247 setup. fdc_hw_init() must be provided by the board
4248 source code. It is used to make hardware dependant
4252 Most IDE controllers were designed to be connected with PCI
4253 interface. Only few of them were designed for AHB interface.
4254 When software is doing ATA command and data transfer to
4255 IDE devices through IDE-AHB controller, some additional
4256 registers accessing to these kind of IDE-AHB controller
4259 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4260 DO NOT CHANGE unless you know exactly what you're
4261 doing! (11-4) [MPC8xx/82xx systems only]
4263 - CONFIG_SYS_INIT_RAM_ADDR:
4265 Start address of memory area that can be used for
4266 initial data and stack; please note that this must be
4267 writable memory that is working WITHOUT special
4268 initialization, i. e. you CANNOT use normal RAM which
4269 will become available only after programming the
4270 memory controller and running certain initialization
4273 U-Boot uses the following memory types:
4274 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4275 - MPC824X: data cache
4276 - PPC4xx: data cache
4278 - CONFIG_SYS_GBL_DATA_OFFSET:
4280 Offset of the initial data structure in the memory
4281 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4282 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4283 data is located at the end of the available space
4284 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4285 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4286 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4287 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4290 On the MPC824X (or other systems that use the data
4291 cache for initial memory) the address chosen for
4292 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4293 point to an otherwise UNUSED address space between
4294 the top of RAM and the start of the PCI space.
4296 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4298 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4300 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4302 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4304 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4306 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4308 - CONFIG_SYS_OR_TIMING_SDRAM:
4311 - CONFIG_SYS_MAMR_PTA:
4312 periodic timer for refresh
4314 - CONFIG_SYS_DER: Debug Event Register (37-47)
4316 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4317 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4318 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4319 CONFIG_SYS_BR1_PRELIM:
4320 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4322 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4323 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4324 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4325 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4327 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4328 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4329 Machine Mode Register and Memory Periodic Timer
4330 Prescaler definitions (SDRAM timing)
4332 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4333 enable I2C microcode relocation patch (MPC8xx);
4334 define relocation offset in DPRAM [DSP2]
4336 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4337 enable SMC microcode relocation patch (MPC8xx);
4338 define relocation offset in DPRAM [SMC1]
4340 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4341 enable SPI microcode relocation patch (MPC8xx);
4342 define relocation offset in DPRAM [SCC4]
4344 - CONFIG_SYS_USE_OSCCLK:
4345 Use OSCM clock mode on MBX8xx board. Be careful,
4346 wrong setting might damage your board. Read
4347 doc/README.MBX before setting this variable!
4349 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4350 Offset of the bootmode word in DPRAM used by post
4351 (Power On Self Tests). This definition overrides
4352 #define'd default value in commproc.h resp.
4355 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4356 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4357 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4358 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4359 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4360 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4361 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4362 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4363 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4365 - CONFIG_PCI_DISABLE_PCIE:
4366 Disable PCI-Express on systems where it is supported but not
4369 - CONFIG_PCI_ENUM_ONLY
4370 Only scan through and get the devices on the busses.
4371 Don't do any setup work, presumably because someone or
4372 something has already done it, and we don't need to do it
4373 a second time. Useful for platforms that are pre-booted
4374 by coreboot or similar.
4376 - CONFIG_PCI_INDIRECT_BRIDGE:
4377 Enable support for indirect PCI bridges.
4380 Chip has SRIO or not
4383 Board has SRIO 1 port available
4386 Board has SRIO 2 port available
4388 - CONFIG_SRIO_PCIE_BOOT_MASTER
4389 Board can support master function for Boot from SRIO and PCIE
4391 - CONFIG_SYS_SRIOn_MEM_VIRT:
4392 Virtual Address of SRIO port 'n' memory region
4394 - CONFIG_SYS_SRIOn_MEM_PHYS:
4395 Physical Address of SRIO port 'n' memory region
4397 - CONFIG_SYS_SRIOn_MEM_SIZE:
4398 Size of SRIO port 'n' memory region
4400 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4401 Defined to tell the NAND controller that the NAND chip is using
4403 Not all NAND drivers use this symbol.
4404 Example of drivers that use it:
4405 - drivers/mtd/nand/ndfc.c
4406 - drivers/mtd/nand/mxc_nand.c
4408 - CONFIG_SYS_NDFC_EBC0_CFG
4409 Sets the EBC0_CFG register for the NDFC. If not defined
4410 a default value will be used.
4413 Get DDR timing information from an I2C EEPROM. Common
4414 with pluggable memory modules such as SODIMMs
4417 I2C address of the SPD EEPROM
4419 - CONFIG_SYS_SPD_BUS_NUM
4420 If SPD EEPROM is on an I2C bus other than the first
4421 one, specify here. Note that the value must resolve
4422 to something your driver can deal with.
4424 - CONFIG_SYS_DDR_RAW_TIMING
4425 Get DDR timing information from other than SPD. Common with
4426 soldered DDR chips onboard without SPD. DDR raw timing
4427 parameters are extracted from datasheet and hard-coded into
4428 header files or board specific files.
4430 - CONFIG_FSL_DDR_INTERACTIVE
4431 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4433 - CONFIG_SYS_83XX_DDR_USES_CS0
4434 Only for 83xx systems. If specified, then DDR should
4435 be configured using CS0 and CS1 instead of CS2 and CS3.
4437 - CONFIG_ETHER_ON_FEC[12]
4438 Define to enable FEC[12] on a 8xx series processor.
4440 - CONFIG_FEC[12]_PHY
4441 Define to the hardcoded PHY address which corresponds
4442 to the given FEC; i. e.
4443 #define CONFIG_FEC1_PHY 4
4444 means that the PHY with address 4 is connected to FEC1
4446 When set to -1, means to probe for first available.
4448 - CONFIG_FEC[12]_PHY_NORXERR
4449 The PHY does not have a RXERR line (RMII only).
4450 (so program the FEC to ignore it).
4453 Enable RMII mode for all FECs.
4454 Note that this is a global option, we can't
4455 have one FEC in standard MII mode and another in RMII mode.
4457 - CONFIG_CRC32_VERIFY
4458 Add a verify option to the crc32 command.
4461 => crc32 -v <address> <count> <crc32>
4463 Where address/count indicate a memory area
4464 and crc32 is the correct crc32 which the
4468 Add the "loopw" memory command. This only takes effect if
4469 the memory commands are activated globally (CONFIG_CMD_MEM).
4472 Add the "mdc" and "mwc" memory commands. These are cyclic
4477 This command will print 4 bytes (10,11,12,13) each 500 ms.
4479 => mwc.l 100 12345678 10
4480 This command will write 12345678 to address 100 all 10 ms.
4482 This only takes effect if the memory commands are activated
4483 globally (CONFIG_CMD_MEM).
4485 - CONFIG_SKIP_LOWLEVEL_INIT
4486 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4487 low level initializations (like setting up the memory
4488 controller) are omitted and/or U-Boot does not
4489 relocate itself into RAM.
4491 Normally this variable MUST NOT be defined. The only
4492 exception is when U-Boot is loaded (to RAM) by some
4493 other boot loader or by a debugger which performs
4494 these initializations itself.
4497 Modifies the behaviour of start.S when compiling a loader
4498 that is executed before the actual U-Boot. E.g. when
4499 compiling a NAND SPL.
4502 Modifies the behaviour of start.S when compiling a loader
4503 that is executed after the SPL and before the actual U-Boot.
4504 It is loaded by the SPL.
4506 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4507 Only for 85xx systems. If this variable is specified, the section
4508 .resetvec is not kept and the section .bootpg is placed in the
4509 previous 4k of the .text section.
4511 - CONFIG_ARCH_MAP_SYSMEM
4512 Generally U-Boot (and in particular the md command) uses
4513 effective address. It is therefore not necessary to regard
4514 U-Boot address as virtual addresses that need to be translated
4515 to physical addresses. However, sandbox requires this, since
4516 it maintains its own little RAM buffer which contains all
4517 addressable memory. This option causes some memory accesses
4518 to be mapped through map_sysmem() / unmap_sysmem().
4520 - CONFIG_USE_ARCH_MEMCPY
4521 CONFIG_USE_ARCH_MEMSET
4522 If these options are used a optimized version of memcpy/memset will
4523 be used if available. These functions may be faster under some
4524 conditions but may increase the binary size.
4526 - CONFIG_X86_RESET_VECTOR
4527 If defined, the x86 reset vector code is included. This is not
4528 needed when U-Boot is running from Coreboot.
4531 Defines the MPU clock speed (in MHz).
4533 NOTE : currently only supported on AM335x platforms.
4535 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4536 Enables the RTC32K OSC on AM33xx based plattforms
4538 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4539 Option to disable subpage write in NAND driver
4540 driver that uses this:
4541 drivers/mtd/nand/davinci_nand.c
4543 Freescale QE/FMAN Firmware Support:
4544 -----------------------------------
4546 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4547 loading of "firmware", which is encoded in the QE firmware binary format.
4548 This firmware often needs to be loaded during U-Boot booting, so macros
4549 are used to identify the storage device (NOR flash, SPI, etc) and the address
4552 - CONFIG_SYS_FMAN_FW_ADDR
4553 The address in the storage device where the FMAN microcode is located. The
4554 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4557 - CONFIG_SYS_QE_FW_ADDR
4558 The address in the storage device where the QE microcode is located. The
4559 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4562 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4563 The maximum possible size of the firmware. The firmware binary format
4564 has a field that specifies the actual size of the firmware, but it
4565 might not be possible to read any part of the firmware unless some
4566 local storage is allocated to hold the entire firmware first.
4568 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4569 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4570 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4571 virtual address in NOR flash.
4573 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4574 Specifies that QE/FMAN firmware is located in NAND flash.
4575 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4577 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4578 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4579 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4581 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4582 Specifies that QE/FMAN firmware is located on the primary SPI
4583 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4585 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4586 Specifies that QE/FMAN firmware is located in the remote (master)
4587 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4588 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4589 window->master inbound window->master LAW->the ucode address in
4590 master's memory space.
4592 Building the Software:
4593 ======================
4595 Building U-Boot has been tested in several native build environments
4596 and in many different cross environments. Of course we cannot support
4597 all possibly existing versions of cross development tools in all
4598 (potentially obsolete) versions. In case of tool chain problems we
4599 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4600 which is extensively used to build and test U-Boot.
4602 If you are not using a native environment, it is assumed that you
4603 have GNU cross compiling tools available in your path. In this case,
4604 you must set the environment variable CROSS_COMPILE in your shell.
4605 Note that no changes to the Makefile or any other source files are
4606 necessary. For example using the ELDK on a 4xx CPU, please enter:
4608 $ CROSS_COMPILE=ppc_4xx-
4609 $ export CROSS_COMPILE
4611 Note: If you wish to generate Windows versions of the utilities in
4612 the tools directory you can use the MinGW toolchain
4613 (http://www.mingw.org). Set your HOST tools to the MinGW
4614 toolchain and execute 'make tools'. For example:
4616 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4618 Binaries such as tools/mkimage.exe will be created which can
4619 be executed on computers running Windows.
4621 U-Boot is intended to be simple to build. After installing the
4622 sources you must configure U-Boot for one specific board type. This
4627 where "NAME_config" is the name of one of the existing configu-
4628 rations; see boards.cfg for supported names.
4630 Note: for some board special configuration names may exist; check if
4631 additional information is available from the board vendor; for
4632 instance, the TQM823L systems are available without (standard)
4633 or with LCD support. You can select such additional "features"
4634 when choosing the configuration, i. e.
4637 - will configure for a plain TQM823L, i. e. no LCD support
4639 make TQM823L_LCD_config
4640 - will configure for a TQM823L with U-Boot console on LCD
4645 Finally, type "make all", and you should get some working U-Boot
4646 images ready for download to / installation on your system:
4648 - "u-boot.bin" is a raw binary image
4649 - "u-boot" is an image in ELF binary format
4650 - "u-boot.srec" is in Motorola S-Record format
4652 By default the build is performed locally and the objects are saved
4653 in the source directory. One of the two methods can be used to change
4654 this behavior and build U-Boot to some external directory:
4656 1. Add O= to the make command line invocations:
4658 make O=/tmp/build distclean
4659 make O=/tmp/build NAME_config
4660 make O=/tmp/build all
4662 2. Set environment variable BUILD_DIR to point to the desired location:
4664 export BUILD_DIR=/tmp/build
4669 Note that the command line "O=" setting overrides the BUILD_DIR environment
4673 Please be aware that the Makefiles assume you are using GNU make, so
4674 for instance on NetBSD you might need to use "gmake" instead of
4678 If the system board that you have is not listed, then you will need
4679 to port U-Boot to your hardware platform. To do this, follow these
4682 1. Add a new configuration option for your board to the toplevel
4683 "boards.cfg" file, using the existing entries as examples.
4684 Follow the instructions there to keep the boards in order.
4685 2. Create a new directory to hold your board specific code. Add any
4686 files you need. In your board directory, you will need at least
4687 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4688 3. Create a new configuration file "include/configs/<board>.h" for
4690 3. If you're porting U-Boot to a new CPU, then also create a new
4691 directory to hold your CPU specific code. Add any files you need.
4692 4. Run "make <board>_config" with your new name.
4693 5. Type "make", and you should get a working "u-boot.srec" file
4694 to be installed on your target system.
4695 6. Debug and solve any problems that might arise.
4696 [Of course, this last step is much harder than it sounds.]
4699 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4700 ==============================================================
4702 If you have modified U-Boot sources (for instance added a new board
4703 or support for new devices, a new CPU, etc.) you are expected to
4704 provide feedback to the other developers. The feedback normally takes
4705 the form of a "patch", i. e. a context diff against a certain (latest
4706 official or latest in the git repository) version of U-Boot sources.
4708 But before you submit such a patch, please verify that your modifi-
4709 cation did not break existing code. At least make sure that *ALL* of
4710 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4711 just run the "MAKEALL" script, which will configure and build U-Boot
4712 for ALL supported system. Be warned, this will take a while. You can
4713 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4714 environment variable to the script, i. e. to use the ELDK cross tools
4717 CROSS_COMPILE=ppc_8xx- MAKEALL
4719 or to build on a native PowerPC system you can type
4721 CROSS_COMPILE=' ' MAKEALL
4723 When using the MAKEALL script, the default behaviour is to build
4724 U-Boot in the source directory. This location can be changed by
4725 setting the BUILD_DIR environment variable. Also, for each target
4726 built, the MAKEALL script saves two log files (<target>.ERR and
4727 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4728 location can be changed by setting the MAKEALL_LOGDIR environment
4729 variable. For example:
4731 export BUILD_DIR=/tmp/build
4732 export MAKEALL_LOGDIR=/tmp/log
4733 CROSS_COMPILE=ppc_8xx- MAKEALL
4735 With the above settings build objects are saved in the /tmp/build,
4736 log files are saved in the /tmp/log and the source tree remains clean
4737 during the whole build process.
4740 See also "U-Boot Porting Guide" below.
4743 Monitor Commands - Overview:
4744 ============================
4746 go - start application at address 'addr'
4747 run - run commands in an environment variable
4748 bootm - boot application image from memory
4749 bootp - boot image via network using BootP/TFTP protocol
4750 bootz - boot zImage from memory
4751 tftpboot- boot image via network using TFTP protocol
4752 and env variables "ipaddr" and "serverip"
4753 (and eventually "gatewayip")
4754 tftpput - upload a file via network using TFTP protocol
4755 rarpboot- boot image via network using RARP/TFTP protocol
4756 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4757 loads - load S-Record file over serial line
4758 loadb - load binary file over serial line (kermit mode)
4760 mm - memory modify (auto-incrementing)
4761 nm - memory modify (constant address)
4762 mw - memory write (fill)
4764 cmp - memory compare
4765 crc32 - checksum calculation
4766 i2c - I2C sub-system
4767 sspi - SPI utility commands
4768 base - print or set address offset
4769 printenv- print environment variables
4770 setenv - set environment variables
4771 saveenv - save environment variables to persistent storage
4772 protect - enable or disable FLASH write protection
4773 erase - erase FLASH memory
4774 flinfo - print FLASH memory information
4775 nand - NAND memory operations (see doc/README.nand)
4776 bdinfo - print Board Info structure
4777 iminfo - print header information for application image
4778 coninfo - print console devices and informations
4779 ide - IDE sub-system
4780 loop - infinite loop on address range
4781 loopw - infinite write loop on address range
4782 mtest - simple RAM test
4783 icache - enable or disable instruction cache
4784 dcache - enable or disable data cache
4785 reset - Perform RESET of the CPU
4786 echo - echo args to console
4787 version - print monitor version
4788 help - print online help
4789 ? - alias for 'help'
4792 Monitor Commands - Detailed Description:
4793 ========================================
4797 For now: just type "help <command>".
4800 Environment Variables:
4801 ======================
4803 U-Boot supports user configuration using Environment Variables which
4804 can be made persistent by saving to Flash memory.
4806 Environment Variables are set using "setenv", printed using
4807 "printenv", and saved to Flash using "saveenv". Using "setenv"
4808 without a value can be used to delete a variable from the
4809 environment. As long as you don't save the environment you are
4810 working with an in-memory copy. In case the Flash area containing the
4811 environment is erased by accident, a default environment is provided.
4813 Some configuration options can be set using Environment Variables.
4815 List of environment variables (most likely not complete):
4817 baudrate - see CONFIG_BAUDRATE
4819 bootdelay - see CONFIG_BOOTDELAY
4821 bootcmd - see CONFIG_BOOTCOMMAND
4823 bootargs - Boot arguments when booting an RTOS image
4825 bootfile - Name of the image to load with TFTP
4827 bootm_low - Memory range available for image processing in the bootm
4828 command can be restricted. This variable is given as
4829 a hexadecimal number and defines lowest address allowed
4830 for use by the bootm command. See also "bootm_size"
4831 environment variable. Address defined by "bootm_low" is
4832 also the base of the initial memory mapping for the Linux
4833 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4836 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4837 This variable is given as a hexadecimal number and it
4838 defines the size of the memory region starting at base
4839 address bootm_low that is accessible by the Linux kernel
4840 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4841 as the default value if it is defined, and bootm_size is
4844 bootm_size - Memory range available for image processing in the bootm
4845 command can be restricted. This variable is given as
4846 a hexadecimal number and defines the size of the region
4847 allowed for use by the bootm command. See also "bootm_low"
4848 environment variable.
4850 updatefile - Location of the software update file on a TFTP server, used
4851 by the automatic software update feature. Please refer to
4852 documentation in doc/README.update for more details.
4854 autoload - if set to "no" (any string beginning with 'n'),
4855 "bootp" will just load perform a lookup of the
4856 configuration from the BOOTP server, but not try to
4857 load any image using TFTP
4859 autostart - if set to "yes", an image loaded using the "bootp",
4860 "rarpboot", "tftpboot" or "diskboot" commands will
4861 be automatically started (by internally calling
4864 If set to "no", a standalone image passed to the
4865 "bootm" command will be copied to the load address
4866 (and eventually uncompressed), but NOT be started.
4867 This can be used to load and uncompress arbitrary
4870 fdt_high - if set this restricts the maximum address that the
4871 flattened device tree will be copied into upon boot.
4872 For example, if you have a system with 1 GB memory
4873 at physical address 0x10000000, while Linux kernel
4874 only recognizes the first 704 MB as low memory, you
4875 may need to set fdt_high as 0x3C000000 to have the
4876 device tree blob be copied to the maximum address
4877 of the 704 MB low memory, so that Linux kernel can
4878 access it during the boot procedure.
4880 If this is set to the special value 0xFFFFFFFF then
4881 the fdt will not be copied at all on boot. For this
4882 to work it must reside in writable memory, have
4883 sufficient padding on the end of it for u-boot to
4884 add the information it needs into it, and the memory
4885 must be accessible by the kernel.
4887 fdtcontroladdr- if set this is the address of the control flattened
4888 device tree used by U-Boot when CONFIG_OF_CONTROL is
4891 i2cfast - (PPC405GP|PPC405EP only)
4892 if set to 'y' configures Linux I2C driver for fast
4893 mode (400kHZ). This environment variable is used in
4894 initialization code. So, for changes to be effective
4895 it must be saved and board must be reset.
4897 initrd_high - restrict positioning of initrd images:
4898 If this variable is not set, initrd images will be
4899 copied to the highest possible address in RAM; this
4900 is usually what you want since it allows for
4901 maximum initrd size. If for some reason you want to
4902 make sure that the initrd image is loaded below the
4903 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4904 variable to a value of "no" or "off" or "0".
4905 Alternatively, you can set it to a maximum upper
4906 address to use (U-Boot will still check that it
4907 does not overwrite the U-Boot stack and data).
4909 For instance, when you have a system with 16 MB
4910 RAM, and want to reserve 4 MB from use by Linux,
4911 you can do this by adding "mem=12M" to the value of
4912 the "bootargs" variable. However, now you must make
4913 sure that the initrd image is placed in the first
4914 12 MB as well - this can be done with
4916 setenv initrd_high 00c00000
4918 If you set initrd_high to 0xFFFFFFFF, this is an
4919 indication to U-Boot that all addresses are legal
4920 for the Linux kernel, including addresses in flash
4921 memory. In this case U-Boot will NOT COPY the
4922 ramdisk at all. This may be useful to reduce the
4923 boot time on your system, but requires that this
4924 feature is supported by your Linux kernel.
4926 ipaddr - IP address; needed for tftpboot command
4928 loadaddr - Default load address for commands like "bootp",
4929 "rarpboot", "tftpboot", "loadb" or "diskboot"
4931 loads_echo - see CONFIG_LOADS_ECHO
4933 serverip - TFTP server IP address; needed for tftpboot command
4935 bootretry - see CONFIG_BOOT_RETRY_TIME
4937 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4939 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4941 ethprime - controls which interface is used first.
4943 ethact - controls which interface is currently active.
4944 For example you can do the following
4946 => setenv ethact FEC
4947 => ping 192.168.0.1 # traffic sent on FEC
4948 => setenv ethact SCC
4949 => ping 10.0.0.1 # traffic sent on SCC
4951 ethrotate - When set to "no" U-Boot does not go through all
4952 available network interfaces.
4953 It just stays at the currently selected interface.
4955 netretry - When set to "no" each network operation will
4956 either succeed or fail without retrying.
4957 When set to "once" the network operation will
4958 fail when all the available network interfaces
4959 are tried once without success.
4960 Useful on scripts which control the retry operation
4963 npe_ucode - set load address for the NPE microcode
4965 silent_linux - If set then linux will be told to boot silently, by
4966 changing the console to be empty. If "yes" it will be
4967 made silent. If "no" it will not be made silent. If
4968 unset, then it will be made silent if the U-Boot console
4971 tftpsrcport - If this is set, the value is used for TFTP's
4974 tftpdstport - If this is set, the value is used for TFTP's UDP
4975 destination port instead of the Well Know Port 69.
4977 tftpblocksize - Block size to use for TFTP transfers; if not set,
4978 we use the TFTP server's default block size
4980 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4981 seconds, minimum value is 1000 = 1 second). Defines
4982 when a packet is considered to be lost so it has to
4983 be retransmitted. The default is 5000 = 5 seconds.
4984 Lowering this value may make downloads succeed
4985 faster in networks with high packet loss rates or
4986 with unreliable TFTP servers.
4988 vlan - When set to a value < 4095 the traffic over
4989 Ethernet is encapsulated/received over 802.1q
4992 The following image location variables contain the location of images
4993 used in booting. The "Image" column gives the role of the image and is
4994 not an environment variable name. The other columns are environment
4995 variable names. "File Name" gives the name of the file on a TFTP
4996 server, "RAM Address" gives the location in RAM the image will be
4997 loaded to, and "Flash Location" gives the image's address in NOR
4998 flash or offset in NAND flash.
5000 *Note* - these variables don't have to be defined for all boards, some
5001 boards currenlty use other variables for these purposes, and some
5002 boards use these variables for other purposes.
5004 Image File Name RAM Address Flash Location
5005 ----- --------- ----------- --------------
5006 u-boot u-boot u-boot_addr_r u-boot_addr
5007 Linux kernel bootfile kernel_addr_r kernel_addr
5008 device tree blob fdtfile fdt_addr_r fdt_addr
5009 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5011 The following environment variables may be used and automatically
5012 updated by the network boot commands ("bootp" and "rarpboot"),
5013 depending the information provided by your boot server:
5015 bootfile - see above
5016 dnsip - IP address of your Domain Name Server
5017 dnsip2 - IP address of your secondary Domain Name Server
5018 gatewayip - IP address of the Gateway (Router) to use
5019 hostname - Target hostname
5021 netmask - Subnet Mask
5022 rootpath - Pathname of the root filesystem on the NFS server
5023 serverip - see above
5026 There are two special Environment Variables:
5028 serial# - contains hardware identification information such
5029 as type string and/or serial number
5030 ethaddr - Ethernet address
5032 These variables can be set only once (usually during manufacturing of
5033 the board). U-Boot refuses to delete or overwrite these variables
5034 once they have been set once.
5037 Further special Environment Variables:
5039 ver - Contains the U-Boot version string as printed
5040 with the "version" command. This variable is
5041 readonly (see CONFIG_VERSION_VARIABLE).
5044 Please note that changes to some configuration parameters may take
5045 only effect after the next boot (yes, that's just like Windoze :-).
5048 Callback functions for environment variables:
5049 ---------------------------------------------
5051 For some environment variables, the behavior of u-boot needs to change
5052 when their values are changed. This functionailty allows functions to
5053 be associated with arbitrary variables. On creation, overwrite, or
5054 deletion, the callback will provide the opportunity for some side
5055 effect to happen or for the change to be rejected.
5057 The callbacks are named and associated with a function using the
5058 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5060 These callbacks are associated with variables in one of two ways. The
5061 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5062 in the board configuration to a string that defines a list of
5063 associations. The list must be in the following format:
5065 entry = variable_name[:callback_name]
5068 If the callback name is not specified, then the callback is deleted.
5069 Spaces are also allowed anywhere in the list.
5071 Callbacks can also be associated by defining the ".callbacks" variable
5072 with the same list format above. Any association in ".callbacks" will
5073 override any association in the static list. You can define
5074 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5075 ".callbacks" envirnoment variable in the default or embedded environment.
5078 Command Line Parsing:
5079 =====================
5081 There are two different command line parsers available with U-Boot:
5082 the old "simple" one, and the much more powerful "hush" shell:
5084 Old, simple command line parser:
5085 --------------------------------
5087 - supports environment variables (through setenv / saveenv commands)
5088 - several commands on one line, separated by ';'
5089 - variable substitution using "... ${name} ..." syntax
5090 - special characters ('$', ';') can be escaped by prefixing with '\',
5092 setenv bootcmd bootm \${address}
5093 - You can also escape text by enclosing in single apostrophes, for example:
5094 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5099 - similar to Bourne shell, with control structures like
5100 if...then...else...fi, for...do...done; while...do...done,
5101 until...do...done, ...
5102 - supports environment ("global") variables (through setenv / saveenv
5103 commands) and local shell variables (through standard shell syntax
5104 "name=value"); only environment variables can be used with "run"
5110 (1) If a command line (or an environment variable executed by a "run"
5111 command) contains several commands separated by semicolon, and
5112 one of these commands fails, then the remaining commands will be
5115 (2) If you execute several variables with one call to run (i. e.
5116 calling run with a list of variables as arguments), any failing
5117 command will cause "run" to terminate, i. e. the remaining
5118 variables are not executed.
5120 Note for Redundant Ethernet Interfaces:
5121 =======================================
5123 Some boards come with redundant Ethernet interfaces; U-Boot supports
5124 such configurations and is capable of automatic selection of a
5125 "working" interface when needed. MAC assignment works as follows:
5127 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5128 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5129 "eth1addr" (=>eth1), "eth2addr", ...
5131 If the network interface stores some valid MAC address (for instance
5132 in SROM), this is used as default address if there is NO correspon-
5133 ding setting in the environment; if the corresponding environment
5134 variable is set, this overrides the settings in the card; that means:
5136 o If the SROM has a valid MAC address, and there is no address in the
5137 environment, the SROM's address is used.
5139 o If there is no valid address in the SROM, and a definition in the
5140 environment exists, then the value from the environment variable is
5143 o If both the SROM and the environment contain a MAC address, and
5144 both addresses are the same, this MAC address is used.
5146 o If both the SROM and the environment contain a MAC address, and the
5147 addresses differ, the value from the environment is used and a
5150 o If neither SROM nor the environment contain a MAC address, an error
5153 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5154 will be programmed into hardware as part of the initialization process. This
5155 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5156 The naming convention is as follows:
5157 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5162 U-Boot is capable of booting (and performing other auxiliary operations on)
5163 images in two formats:
5165 New uImage format (FIT)
5166 -----------------------
5168 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5169 to Flattened Device Tree). It allows the use of images with multiple
5170 components (several kernels, ramdisks, etc.), with contents protected by
5171 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5177 Old image format is based on binary files which can be basically anything,
5178 preceded by a special header; see the definitions in include/image.h for
5179 details; basically, the header defines the following image properties:
5181 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5182 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5183 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5184 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5186 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5187 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5188 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5189 * Compression Type (uncompressed, gzip, bzip2)
5195 The header is marked by a special Magic Number, and both the header
5196 and the data portions of the image are secured against corruption by
5203 Although U-Boot should support any OS or standalone application
5204 easily, the main focus has always been on Linux during the design of
5207 U-Boot includes many features that so far have been part of some
5208 special "boot loader" code within the Linux kernel. Also, any
5209 "initrd" images to be used are no longer part of one big Linux image;
5210 instead, kernel and "initrd" are separate images. This implementation
5211 serves several purposes:
5213 - the same features can be used for other OS or standalone
5214 applications (for instance: using compressed images to reduce the
5215 Flash memory footprint)
5217 - it becomes much easier to port new Linux kernel versions because
5218 lots of low-level, hardware dependent stuff are done by U-Boot
5220 - the same Linux kernel image can now be used with different "initrd"
5221 images; of course this also means that different kernel images can
5222 be run with the same "initrd". This makes testing easier (you don't
5223 have to build a new "zImage.initrd" Linux image when you just
5224 change a file in your "initrd"). Also, a field-upgrade of the
5225 software is easier now.
5231 Porting Linux to U-Boot based systems:
5232 ---------------------------------------
5234 U-Boot cannot save you from doing all the necessary modifications to
5235 configure the Linux device drivers for use with your target hardware
5236 (no, we don't intend to provide a full virtual machine interface to
5239 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5241 Just make sure your machine specific header file (for instance
5242 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5243 Information structure as we define in include/asm-<arch>/u-boot.h,
5244 and make sure that your definition of IMAP_ADDR uses the same value
5245 as your U-Boot configuration in CONFIG_SYS_IMMR.
5248 Configuring the Linux kernel:
5249 -----------------------------
5251 No specific requirements for U-Boot. Make sure you have some root
5252 device (initial ramdisk, NFS) for your target system.
5255 Building a Linux Image:
5256 -----------------------
5258 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5259 not used. If you use recent kernel source, a new build target
5260 "uImage" will exist which automatically builds an image usable by
5261 U-Boot. Most older kernels also have support for a "pImage" target,
5262 which was introduced for our predecessor project PPCBoot and uses a
5263 100% compatible format.
5272 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5273 encapsulate a compressed Linux kernel image with header information,
5274 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5276 * build a standard "vmlinux" kernel image (in ELF binary format):
5278 * convert the kernel into a raw binary image:
5280 ${CROSS_COMPILE}-objcopy -O binary \
5281 -R .note -R .comment \
5282 -S vmlinux linux.bin
5284 * compress the binary image:
5288 * package compressed binary image for U-Boot:
5290 mkimage -A ppc -O linux -T kernel -C gzip \
5291 -a 0 -e 0 -n "Linux Kernel Image" \
5292 -d linux.bin.gz uImage
5295 The "mkimage" tool can also be used to create ramdisk images for use
5296 with U-Boot, either separated from the Linux kernel image, or
5297 combined into one file. "mkimage" encapsulates the images with a 64
5298 byte header containing information about target architecture,
5299 operating system, image type, compression method, entry points, time
5300 stamp, CRC32 checksums, etc.
5302 "mkimage" can be called in two ways: to verify existing images and
5303 print the header information, or to build new images.
5305 In the first form (with "-l" option) mkimage lists the information
5306 contained in the header of an existing U-Boot image; this includes
5307 checksum verification:
5309 tools/mkimage -l image
5310 -l ==> list image header information
5312 The second form (with "-d" option) is used to build a U-Boot image
5313 from a "data file" which is used as image payload:
5315 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5316 -n name -d data_file image
5317 -A ==> set architecture to 'arch'
5318 -O ==> set operating system to 'os'
5319 -T ==> set image type to 'type'
5320 -C ==> set compression type 'comp'
5321 -a ==> set load address to 'addr' (hex)
5322 -e ==> set entry point to 'ep' (hex)
5323 -n ==> set image name to 'name'
5324 -d ==> use image data from 'datafile'
5326 Right now, all Linux kernels for PowerPC systems use the same load
5327 address (0x00000000), but the entry point address depends on the
5330 - 2.2.x kernels have the entry point at 0x0000000C,
5331 - 2.3.x and later kernels have the entry point at 0x00000000.
5333 So a typical call to build a U-Boot image would read:
5335 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5336 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5337 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5338 > examples/uImage.TQM850L
5339 Image Name: 2.4.4 kernel for TQM850L
5340 Created: Wed Jul 19 02:34:59 2000
5341 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5342 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5343 Load Address: 0x00000000
5344 Entry Point: 0x00000000
5346 To verify the contents of the image (or check for corruption):
5348 -> tools/mkimage -l examples/uImage.TQM850L
5349 Image Name: 2.4.4 kernel for TQM850L
5350 Created: Wed Jul 19 02:34:59 2000
5351 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5352 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5353 Load Address: 0x00000000
5354 Entry Point: 0x00000000
5356 NOTE: for embedded systems where boot time is critical you can trade
5357 speed for memory and install an UNCOMPRESSED image instead: this
5358 needs more space in Flash, but boots much faster since it does not
5359 need to be uncompressed:
5361 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5362 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5363 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5364 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5365 > examples/uImage.TQM850L-uncompressed
5366 Image Name: 2.4.4 kernel for TQM850L
5367 Created: Wed Jul 19 02:34:59 2000
5368 Image Type: PowerPC Linux Kernel Image (uncompressed)
5369 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5370 Load Address: 0x00000000
5371 Entry Point: 0x00000000
5374 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5375 when your kernel is intended to use an initial ramdisk:
5377 -> tools/mkimage -n 'Simple Ramdisk Image' \
5378 > -A ppc -O linux -T ramdisk -C gzip \
5379 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5380 Image Name: Simple Ramdisk Image
5381 Created: Wed Jan 12 14:01:50 2000
5382 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5383 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5384 Load Address: 0x00000000
5385 Entry Point: 0x00000000
5387 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5388 option performs the converse operation of the mkimage's second form (the "-d"
5389 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5392 tools/dumpimage -i image -p position data_file
5393 -i ==> extract from the 'image' a specific 'data_file', \
5394 indexed by 'position'
5397 Installing a Linux Image:
5398 -------------------------
5400 To downloading a U-Boot image over the serial (console) interface,
5401 you must convert the image to S-Record format:
5403 objcopy -I binary -O srec examples/image examples/image.srec
5405 The 'objcopy' does not understand the information in the U-Boot
5406 image header, so the resulting S-Record file will be relative to
5407 address 0x00000000. To load it to a given address, you need to
5408 specify the target address as 'offset' parameter with the 'loads'
5411 Example: install the image to address 0x40100000 (which on the
5412 TQM8xxL is in the first Flash bank):
5414 => erase 40100000 401FFFFF
5420 ## Ready for S-Record download ...
5421 ~>examples/image.srec
5422 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5424 15989 15990 15991 15992
5425 [file transfer complete]
5427 ## Start Addr = 0x00000000
5430 You can check the success of the download using the 'iminfo' command;
5431 this includes a checksum verification so you can be sure no data
5432 corruption happened:
5436 ## Checking Image at 40100000 ...
5437 Image Name: 2.2.13 for initrd on TQM850L
5438 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5439 Data Size: 335725 Bytes = 327 kB = 0 MB
5440 Load Address: 00000000
5441 Entry Point: 0000000c
5442 Verifying Checksum ... OK
5448 The "bootm" command is used to boot an application that is stored in
5449 memory (RAM or Flash). In case of a Linux kernel image, the contents
5450 of the "bootargs" environment variable is passed to the kernel as
5451 parameters. You can check and modify this variable using the
5452 "printenv" and "setenv" commands:
5455 => printenv bootargs
5456 bootargs=root=/dev/ram
5458 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5460 => printenv bootargs
5461 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5464 ## Booting Linux kernel at 40020000 ...
5465 Image Name: 2.2.13 for NFS on TQM850L
5466 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5467 Data Size: 381681 Bytes = 372 kB = 0 MB
5468 Load Address: 00000000
5469 Entry Point: 0000000c
5470 Verifying Checksum ... OK
5471 Uncompressing Kernel Image ... OK
5472 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
5473 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5474 time_init: decrementer frequency = 187500000/60
5475 Calibrating delay loop... 49.77 BogoMIPS
5476 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5479 If you want to boot a Linux kernel with initial RAM disk, you pass
5480 the memory addresses of both the kernel and the initrd image (PPBCOOT
5481 format!) to the "bootm" command:
5483 => imi 40100000 40200000
5485 ## Checking Image at 40100000 ...
5486 Image Name: 2.2.13 for initrd on TQM850L
5487 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5488 Data Size: 335725 Bytes = 327 kB = 0 MB
5489 Load Address: 00000000
5490 Entry Point: 0000000c
5491 Verifying Checksum ... OK
5493 ## Checking Image at 40200000 ...
5494 Image Name: Simple Ramdisk Image
5495 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5496 Data Size: 566530 Bytes = 553 kB = 0 MB
5497 Load Address: 00000000
5498 Entry Point: 00000000
5499 Verifying Checksum ... OK
5501 => bootm 40100000 40200000
5502 ## Booting Linux kernel at 40100000 ...
5503 Image Name: 2.2.13 for initrd on TQM850L
5504 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5505 Data Size: 335725 Bytes = 327 kB = 0 MB
5506 Load Address: 00000000
5507 Entry Point: 0000000c
5508 Verifying Checksum ... OK
5509 Uncompressing Kernel Image ... OK
5510 ## Loading RAMDisk Image at 40200000 ...
5511 Image Name: Simple Ramdisk Image
5512 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5513 Data Size: 566530 Bytes = 553 kB = 0 MB
5514 Load Address: 00000000
5515 Entry Point: 00000000
5516 Verifying Checksum ... OK
5517 Loading Ramdisk ... OK
5518 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
5519 Boot arguments: root=/dev/ram
5520 time_init: decrementer frequency = 187500000/60
5521 Calibrating delay loop... 49.77 BogoMIPS
5523 RAMDISK: Compressed image found at block 0
5524 VFS: Mounted root (ext2 filesystem).
5528 Boot Linux and pass a flat device tree:
5531 First, U-Boot must be compiled with the appropriate defines. See the section
5532 titled "Linux Kernel Interface" above for a more in depth explanation. The
5533 following is an example of how to start a kernel and pass an updated
5539 oft=oftrees/mpc8540ads.dtb
5540 => tftp $oftaddr $oft
5541 Speed: 1000, full duplex
5543 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5544 Filename 'oftrees/mpc8540ads.dtb'.
5545 Load address: 0x300000
5548 Bytes transferred = 4106 (100a hex)
5549 => tftp $loadaddr $bootfile
5550 Speed: 1000, full duplex
5552 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5554 Load address: 0x200000
5555 Loading:############
5557 Bytes transferred = 1029407 (fb51f hex)
5562 => bootm $loadaddr - $oftaddr
5563 ## Booting image at 00200000 ...
5564 Image Name: Linux-2.6.17-dirty
5565 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5566 Data Size: 1029343 Bytes = 1005.2 kB
5567 Load Address: 00000000
5568 Entry Point: 00000000
5569 Verifying Checksum ... OK
5570 Uncompressing Kernel Image ... OK
5571 Booting using flat device tree at 0x300000
5572 Using MPC85xx ADS machine description
5573 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5577 More About U-Boot Image Types:
5578 ------------------------------
5580 U-Boot supports the following image types:
5582 "Standalone Programs" are directly runnable in the environment
5583 provided by U-Boot; it is expected that (if they behave
5584 well) you can continue to work in U-Boot after return from
5585 the Standalone Program.
5586 "OS Kernel Images" are usually images of some Embedded OS which
5587 will take over control completely. Usually these programs
5588 will install their own set of exception handlers, device
5589 drivers, set up the MMU, etc. - this means, that you cannot
5590 expect to re-enter U-Boot except by resetting the CPU.
5591 "RAMDisk Images" are more or less just data blocks, and their
5592 parameters (address, size) are passed to an OS kernel that is
5594 "Multi-File Images" contain several images, typically an OS
5595 (Linux) kernel image and one or more data images like
5596 RAMDisks. This construct is useful for instance when you want
5597 to boot over the network using BOOTP etc., where the boot
5598 server provides just a single image file, but you want to get
5599 for instance an OS kernel and a RAMDisk image.
5601 "Multi-File Images" start with a list of image sizes, each
5602 image size (in bytes) specified by an "uint32_t" in network
5603 byte order. This list is terminated by an "(uint32_t)0".
5604 Immediately after the terminating 0 follow the images, one by
5605 one, all aligned on "uint32_t" boundaries (size rounded up to
5606 a multiple of 4 bytes).
5608 "Firmware Images" are binary images containing firmware (like
5609 U-Boot or FPGA images) which usually will be programmed to
5612 "Script files" are command sequences that will be executed by
5613 U-Boot's command interpreter; this feature is especially
5614 useful when you configure U-Boot to use a real shell (hush)
5615 as command interpreter.
5617 Booting the Linux zImage:
5618 -------------------------
5620 On some platforms, it's possible to boot Linux zImage. This is done
5621 using the "bootz" command. The syntax of "bootz" command is the same
5622 as the syntax of "bootm" command.
5624 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5625 kernel with raw initrd images. The syntax is slightly different, the
5626 address of the initrd must be augmented by it's size, in the following
5627 format: "<initrd addres>:<initrd size>".
5633 One of the features of U-Boot is that you can dynamically load and
5634 run "standalone" applications, which can use some resources of
5635 U-Boot like console I/O functions or interrupt services.
5637 Two simple examples are included with the sources:
5642 'examples/hello_world.c' contains a small "Hello World" Demo
5643 application; it is automatically compiled when you build U-Boot.
5644 It's configured to run at address 0x00040004, so you can play with it
5648 ## Ready for S-Record download ...
5649 ~>examples/hello_world.srec
5650 1 2 3 4 5 6 7 8 9 10 11 ...
5651 [file transfer complete]
5653 ## Start Addr = 0x00040004
5655 => go 40004 Hello World! This is a test.
5656 ## Starting application at 0x00040004 ...
5667 Hit any key to exit ...
5669 ## Application terminated, rc = 0x0
5671 Another example, which demonstrates how to register a CPM interrupt
5672 handler with the U-Boot code, can be found in 'examples/timer.c'.
5673 Here, a CPM timer is set up to generate an interrupt every second.
5674 The interrupt service routine is trivial, just printing a '.'
5675 character, but this is just a demo program. The application can be
5676 controlled by the following keys:
5678 ? - print current values og the CPM Timer registers
5679 b - enable interrupts and start timer
5680 e - stop timer and disable interrupts
5681 q - quit application
5684 ## Ready for S-Record download ...
5685 ~>examples/timer.srec
5686 1 2 3 4 5 6 7 8 9 10 11 ...
5687 [file transfer complete]
5689 ## Start Addr = 0x00040004
5692 ## Starting application at 0x00040004 ...
5695 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5698 [q, b, e, ?] Set interval 1000000 us
5701 [q, b, e, ?] ........
5702 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5705 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5708 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5711 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5713 [q, b, e, ?] ...Stopping timer
5715 [q, b, e, ?] ## Application terminated, rc = 0x0
5721 Over time, many people have reported problems when trying to use the
5722 "minicom" terminal emulation program for serial download. I (wd)
5723 consider minicom to be broken, and recommend not to use it. Under
5724 Unix, I recommend to use C-Kermit for general purpose use (and
5725 especially for kermit binary protocol download ("loadb" command), and
5726 use "cu" for S-Record download ("loads" command). See
5727 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5728 for help with kermit.
5731 Nevertheless, if you absolutely want to use it try adding this
5732 configuration to your "File transfer protocols" section:
5734 Name Program Name U/D FullScr IO-Red. Multi
5735 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5736 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5742 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5743 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5745 Building requires a cross environment; it is known to work on
5746 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5747 need gmake since the Makefiles are not compatible with BSD make).
5748 Note that the cross-powerpc package does not install include files;
5749 attempting to build U-Boot will fail because <machine/ansi.h> is
5750 missing. This file has to be installed and patched manually:
5752 # cd /usr/pkg/cross/powerpc-netbsd/include
5754 # ln -s powerpc machine
5755 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5756 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5758 Native builds *don't* work due to incompatibilities between native
5759 and U-Boot include files.
5761 Booting assumes that (the first part of) the image booted is a
5762 stage-2 loader which in turn loads and then invokes the kernel
5763 proper. Loader sources will eventually appear in the NetBSD source
5764 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5765 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5768 Implementation Internals:
5769 =========================
5771 The following is not intended to be a complete description of every
5772 implementation detail. However, it should help to understand the
5773 inner workings of U-Boot and make it easier to port it to custom
5777 Initial Stack, Global Data:
5778 ---------------------------
5780 The implementation of U-Boot is complicated by the fact that U-Boot
5781 starts running out of ROM (flash memory), usually without access to
5782 system RAM (because the memory controller is not initialized yet).
5783 This means that we don't have writable Data or BSS segments, and BSS
5784 is not initialized as zero. To be able to get a C environment working
5785 at all, we have to allocate at least a minimal stack. Implementation
5786 options for this are defined and restricted by the CPU used: Some CPU
5787 models provide on-chip memory (like the IMMR area on MPC8xx and
5788 MPC826x processors), on others (parts of) the data cache can be
5789 locked as (mis-) used as memory, etc.
5791 Chris Hallinan posted a good summary of these issues to the
5792 U-Boot mailing list:
5794 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5795 From: "Chris Hallinan" <clh@net1plus.com>
5796 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5799 Correct me if I'm wrong, folks, but the way I understand it
5800 is this: Using DCACHE as initial RAM for Stack, etc, does not
5801 require any physical RAM backing up the cache. The cleverness
5802 is that the cache is being used as a temporary supply of
5803 necessary storage before the SDRAM controller is setup. It's
5804 beyond the scope of this list to explain the details, but you
5805 can see how this works by studying the cache architecture and
5806 operation in the architecture and processor-specific manuals.
5808 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5809 is another option for the system designer to use as an
5810 initial stack/RAM area prior to SDRAM being available. Either
5811 option should work for you. Using CS 4 should be fine if your
5812 board designers haven't used it for something that would
5813 cause you grief during the initial boot! It is frequently not
5816 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5817 with your processor/board/system design. The default value
5818 you will find in any recent u-boot distribution in
5819 walnut.h should work for you. I'd set it to a value larger
5820 than your SDRAM module. If you have a 64MB SDRAM module, set
5821 it above 400_0000. Just make sure your board has no resources
5822 that are supposed to respond to that address! That code in
5823 start.S has been around a while and should work as is when
5824 you get the config right.
5829 It is essential to remember this, since it has some impact on the C
5830 code for the initialization procedures:
5832 * Initialized global data (data segment) is read-only. Do not attempt
5835 * Do not use any uninitialized global data (or implicitely initialized
5836 as zero data - BSS segment) at all - this is undefined, initiali-
5837 zation is performed later (when relocating to RAM).
5839 * Stack space is very limited. Avoid big data buffers or things like
5842 Having only the stack as writable memory limits means we cannot use
5843 normal global data to share information beween the code. But it
5844 turned out that the implementation of U-Boot can be greatly
5845 simplified by making a global data structure (gd_t) available to all
5846 functions. We could pass a pointer to this data as argument to _all_
5847 functions, but this would bloat the code. Instead we use a feature of
5848 the GCC compiler (Global Register Variables) to share the data: we
5849 place a pointer (gd) to the global data into a register which we
5850 reserve for this purpose.
5852 When choosing a register for such a purpose we are restricted by the
5853 relevant (E)ABI specifications for the current architecture, and by
5854 GCC's implementation.
5856 For PowerPC, the following registers have specific use:
5858 R2: reserved for system use
5859 R3-R4: parameter passing and return values
5860 R5-R10: parameter passing
5861 R13: small data area pointer
5865 (U-Boot also uses R12 as internal GOT pointer. r12
5866 is a volatile register so r12 needs to be reset when
5867 going back and forth between asm and C)
5869 ==> U-Boot will use R2 to hold a pointer to the global data
5871 Note: on PPC, we could use a static initializer (since the
5872 address of the global data structure is known at compile time),
5873 but it turned out that reserving a register results in somewhat
5874 smaller code - although the code savings are not that big (on
5875 average for all boards 752 bytes for the whole U-Boot image,
5876 624 text + 127 data).
5878 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5879 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5881 ==> U-Boot will use P3 to hold a pointer to the global data
5883 On ARM, the following registers are used:
5885 R0: function argument word/integer result
5886 R1-R3: function argument word
5887 R9: platform specific
5888 R10: stack limit (used only if stack checking is enabled)
5889 R11: argument (frame) pointer
5890 R12: temporary workspace
5893 R15: program counter
5895 ==> U-Boot will use R9 to hold a pointer to the global data
5897 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5899 On Nios II, the ABI is documented here:
5900 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5902 ==> U-Boot will use gp to hold a pointer to the global data
5904 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5905 to access small data sections, so gp is free.
5907 On NDS32, the following registers are used:
5909 R0-R1: argument/return
5911 R15: temporary register for assembler
5912 R16: trampoline register
5913 R28: frame pointer (FP)
5914 R29: global pointer (GP)
5915 R30: link register (LP)
5916 R31: stack pointer (SP)
5917 PC: program counter (PC)
5919 ==> U-Boot will use R10 to hold a pointer to the global data
5921 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5922 or current versions of GCC may "optimize" the code too much.
5927 U-Boot runs in system state and uses physical addresses, i.e. the
5928 MMU is not used either for address mapping nor for memory protection.
5930 The available memory is mapped to fixed addresses using the memory
5931 controller. In this process, a contiguous block is formed for each
5932 memory type (Flash, SDRAM, SRAM), even when it consists of several
5933 physical memory banks.
5935 U-Boot is installed in the first 128 kB of the first Flash bank (on
5936 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5937 booting and sizing and initializing DRAM, the code relocates itself
5938 to the upper end of DRAM. Immediately below the U-Boot code some
5939 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5940 configuration setting]. Below that, a structure with global Board
5941 Info data is placed, followed by the stack (growing downward).
5943 Additionally, some exception handler code is copied to the low 8 kB
5944 of DRAM (0x00000000 ... 0x00001FFF).
5946 So a typical memory configuration with 16 MB of DRAM could look like
5949 0x0000 0000 Exception Vector code
5952 0x0000 2000 Free for Application Use
5958 0x00FB FF20 Monitor Stack (Growing downward)
5959 0x00FB FFAC Board Info Data and permanent copy of global data
5960 0x00FC 0000 Malloc Arena
5963 0x00FE 0000 RAM Copy of Monitor Code
5964 ... eventually: LCD or video framebuffer
5965 ... eventually: pRAM (Protected RAM - unchanged by reset)
5966 0x00FF FFFF [End of RAM]
5969 System Initialization:
5970 ----------------------
5972 In the reset configuration, U-Boot starts at the reset entry point
5973 (on most PowerPC systems at address 0x00000100). Because of the reset
5974 configuration for CS0# this is a mirror of the onboard Flash memory.
5975 To be able to re-map memory U-Boot then jumps to its link address.
5976 To be able to implement the initialization code in C, a (small!)
5977 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5978 which provide such a feature like MPC8xx or MPC8260), or in a locked
5979 part of the data cache. After that, U-Boot initializes the CPU core,
5980 the caches and the SIU.
5982 Next, all (potentially) available memory banks are mapped using a
5983 preliminary mapping. For example, we put them on 512 MB boundaries
5984 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5985 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5986 programmed for SDRAM access. Using the temporary configuration, a
5987 simple memory test is run that determines the size of the SDRAM
5990 When there is more than one SDRAM bank, and the banks are of
5991 different size, the largest is mapped first. For equal size, the first
5992 bank (CS2#) is mapped first. The first mapping is always for address
5993 0x00000000, with any additional banks following immediately to create
5994 contiguous memory starting from 0.
5996 Then, the monitor installs itself at the upper end of the SDRAM area
5997 and allocates memory for use by malloc() and for the global Board
5998 Info data; also, the exception vector code is copied to the low RAM
5999 pages, and the final stack is set up.
6001 Only after this relocation will you have a "normal" C environment;
6002 until that you are restricted in several ways, mostly because you are
6003 running from ROM, and because the code will have to be relocated to a
6007 U-Boot Porting Guide:
6008 ----------------------
6010 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6014 int main(int argc, char *argv[])
6016 sighandler_t no_more_time;
6018 signal(SIGALRM, no_more_time);
6019 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6021 if (available_money > available_manpower) {
6022 Pay consultant to port U-Boot;
6026 Download latest U-Boot source;
6028 Subscribe to u-boot mailing list;
6031 email("Hi, I am new to U-Boot, how do I get started?");
6034 Read the README file in the top level directory;
6035 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6036 Read applicable doc/*.README;
6037 Read the source, Luke;
6038 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6041 if (available_money > toLocalCurrency ($2500))
6044 Add a lot of aggravation and time;
6046 if (a similar board exists) { /* hopefully... */
6047 cp -a board/<similar> board/<myboard>
6048 cp include/configs/<similar>.h include/configs/<myboard>.h
6050 Create your own board support subdirectory;
6051 Create your own board include/configs/<myboard>.h file;
6053 Edit new board/<myboard> files
6054 Edit new include/configs/<myboard>.h
6059 Add / modify source code;
6063 email("Hi, I am having problems...");
6065 Send patch file to the U-Boot email list;
6066 if (reasonable critiques)
6067 Incorporate improvements from email list code review;
6069 Defend code as written;
6075 void no_more_time (int sig)
6084 All contributions to U-Boot should conform to the Linux kernel
6085 coding style; see the file "Documentation/CodingStyle" and the script
6086 "scripts/Lindent" in your Linux kernel source directory.
6088 Source files originating from a different project (for example the
6089 MTD subsystem) are generally exempt from these guidelines and are not
6090 reformated to ease subsequent migration to newer versions of those
6093 Please note that U-Boot is implemented in C (and to some small parts in
6094 Assembler); no C++ is used, so please do not use C++ style comments (//)
6097 Please also stick to the following formatting rules:
6098 - remove any trailing white space
6099 - use TAB characters for indentation and vertical alignment, not spaces
6100 - make sure NOT to use DOS '\r\n' line feeds
6101 - do not add more than 2 consecutive empty lines to source files
6102 - do not add trailing empty lines to source files
6104 Submissions which do not conform to the standards may be returned
6105 with a request to reformat the changes.
6111 Since the number of patches for U-Boot is growing, we need to
6112 establish some rules. Submissions which do not conform to these rules
6113 may be rejected, even when they contain important and valuable stuff.
6115 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6117 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6118 see http://lists.denx.de/mailman/listinfo/u-boot
6120 When you send a patch, please include the following information with
6123 * For bug fixes: a description of the bug and how your patch fixes
6124 this bug. Please try to include a way of demonstrating that the
6125 patch actually fixes something.
6127 * For new features: a description of the feature and your
6130 * A CHANGELOG entry as plaintext (separate from the patch)
6132 * For major contributions, your entry to the CREDITS file
6134 * When you add support for a new board, don't forget to add a
6135 maintainer e-mail address to the boards.cfg file, too.
6137 * If your patch adds new configuration options, don't forget to
6138 document these in the README file.
6140 * The patch itself. If you are using git (which is *strongly*
6141 recommended) you can easily generate the patch using the
6142 "git format-patch". If you then use "git send-email" to send it to
6143 the U-Boot mailing list, you will avoid most of the common problems
6144 with some other mail clients.
6146 If you cannot use git, use "diff -purN OLD NEW". If your version of
6147 diff does not support these options, then get the latest version of
6150 The current directory when running this command shall be the parent
6151 directory of the U-Boot source tree (i. e. please make sure that
6152 your patch includes sufficient directory information for the
6155 We prefer patches as plain text. MIME attachments are discouraged,
6156 and compressed attachments must not be used.
6158 * If one logical set of modifications affects or creates several
6159 files, all these changes shall be submitted in a SINGLE patch file.
6161 * Changesets that contain different, unrelated modifications shall be
6162 submitted as SEPARATE patches, one patch per changeset.
6167 * Before sending the patch, run the MAKEALL script on your patched
6168 source tree and make sure that no errors or warnings are reported
6169 for any of the boards.
6171 * Keep your modifications to the necessary minimum: A patch
6172 containing several unrelated changes or arbitrary reformats will be
6173 returned with a request to re-formatting / split it.
6175 * If you modify existing code, make sure that your new code does not
6176 add to the memory footprint of the code ;-) Small is beautiful!
6177 When adding new features, these should compile conditionally only
6178 (using #ifdef), and the resulting code with the new feature
6179 disabled must not need more memory than the old code without your
6182 * Remember that there is a size limit of 100 kB per message on the
6183 u-boot mailing list. Bigger patches will be moderated. If they are
6184 reasonable and not too big, they will be acknowledged. But patches
6185 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob