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 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_IFC_BE
475 Defines the IFC controller register space as Big Endian
477 CONFIG_SYS_FSL_IFC_LE
478 Defines the IFC controller register space as Little Endian
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
489 CONFIG_SYS_FSL_DDR_BE
490 Defines the DDR controller register space as Big Endian
492 CONFIG_SYS_FSL_DDR_LE
493 Defines the DDR controller register space as Little Endian
495 - Intel Monahans options:
496 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
498 Defines the Monahans run mode to oscillator
499 ratio. Valid values are 8, 16, 24, 31. The core
500 frequency is this value multiplied by 13 MHz.
502 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
504 Defines the Monahans turbo mode to oscillator
505 ratio. Valid values are 1 (default if undefined) and
506 2. The core frequency as calculated above is multiplied
510 CONFIG_SYS_INIT_SP_OFFSET
512 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
513 pointer. This is needed for the temporary stack before
516 CONFIG_SYS_MIPS_CACHE_MODE
518 Cache operation mode for the MIPS CPU.
519 See also arch/mips/include/asm/mipsregs.h.
521 CONF_CM_CACHABLE_NO_WA
524 CONF_CM_CACHABLE_NONCOHERENT
528 CONF_CM_CACHABLE_ACCELERATED
530 CONFIG_SYS_XWAY_EBU_BOOTCFG
532 Special option for Lantiq XWAY SoCs for booting from NOR flash.
533 See also arch/mips/cpu/mips32/start.S.
535 CONFIG_XWAY_SWAP_BYTES
537 Enable compilation of tools/xway-swap-bytes needed for Lantiq
538 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
539 be swapped if a flash programmer is used.
542 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
544 Select high exception vectors of the ARM core, e.g., do not
545 clear the V bit of the c1 register of CP15.
547 CONFIG_SYS_THUMB_BUILD
549 Use this flag to build U-Boot using the Thumb instruction
550 set for ARM architectures. Thumb instruction set provides
551 better code density. For ARM architectures that support
552 Thumb2 this flag will result in Thumb2 code generated by
555 CONFIG_ARM_ERRATA_716044
556 CONFIG_ARM_ERRATA_742230
557 CONFIG_ARM_ERRATA_743622
558 CONFIG_ARM_ERRATA_751472
560 If set, the workarounds for these ARM errata are applied early
561 during U-Boot startup. Note that these options force the
562 workarounds to be applied; no CPU-type/version detection
563 exists, unlike the similar options in the Linux kernel. Do not
564 set these options unless they apply!
569 The frequency of the timer returned by get_timer().
570 get_timer() must operate in milliseconds and this CONFIG
571 option must be set to 1000.
573 - Linux Kernel Interface:
576 U-Boot stores all clock information in Hz
577 internally. For binary compatibility with older Linux
578 kernels (which expect the clocks passed in the
579 bd_info data to be in MHz) the environment variable
580 "clocks_in_mhz" can be defined so that U-Boot
581 converts clock data to MHZ before passing it to the
583 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
584 "clocks_in_mhz=1" is automatically included in the
587 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
589 When transferring memsize parameter to linux, some versions
590 expect it to be in bytes, others in MB.
591 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
595 New kernel versions are expecting firmware settings to be
596 passed using flattened device trees (based on open firmware
600 * New libfdt-based support
601 * Adds the "fdt" command
602 * The bootm command automatically updates the fdt
604 OF_CPU - The proper name of the cpus node (only required for
605 MPC512X and MPC5xxx based boards).
606 OF_SOC - The proper name of the soc node (only required for
607 MPC512X and MPC5xxx based boards).
608 OF_TBCLK - The timebase frequency.
609 OF_STDOUT_PATH - The path to the console device
611 boards with QUICC Engines require OF_QE to set UCC MAC
614 CONFIG_OF_BOARD_SETUP
616 Board code has addition modification that it wants to make
617 to the flat device tree before handing it off to the kernel
621 This define fills in the correct boot CPU in the boot
622 param header, the default value is zero if undefined.
626 U-Boot can detect if an IDE device is present or not.
627 If not, and this new config option is activated, U-Boot
628 removes the ATA node from the DTS before booting Linux,
629 so the Linux IDE driver does not probe the device and
630 crash. This is needed for buggy hardware (uc101) where
631 no pull down resistor is connected to the signal IDE5V_DD7.
633 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
635 This setting is mandatory for all boards that have only one
636 machine type and must be used to specify the machine type
637 number as it appears in the ARM machine registry
638 (see http://www.arm.linux.org.uk/developer/machines/).
639 Only boards that have multiple machine types supported
640 in a single configuration file and the machine type is
641 runtime discoverable, do not have to use this setting.
643 - vxWorks boot parameters:
645 bootvx constructs a valid bootline using the following
646 environments variables: bootfile, ipaddr, serverip, hostname.
647 It loads the vxWorks image pointed bootfile.
649 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
650 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
651 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
652 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
654 CONFIG_SYS_VXWORKS_ADD_PARAMS
656 Add it at the end of the bootline. E.g "u=username pw=secret"
658 Note: If a "bootargs" environment is defined, it will overwride
659 the defaults discussed just above.
661 - Cache Configuration:
662 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
663 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
664 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
666 - Cache Configuration for ARM:
667 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
669 CONFIG_SYS_PL310_BASE - Physical base address of PL310
670 controller register space
675 Define this if you want support for Amba PrimeCell PL010 UARTs.
679 Define this if you want support for Amba PrimeCell PL011 UARTs.
683 If you have Amba PrimeCell PL011 UARTs, set this variable to
684 the clock speed of the UARTs.
688 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
689 define this to a list of base addresses for each (supported)
690 port. See e.g. include/configs/versatile.h
692 CONFIG_PL011_SERIAL_RLCR
694 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
695 have separate receive and transmit line control registers. Set
696 this variable to initialize the extra register.
698 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
700 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
701 boot loader that has already initialized the UART. Define this
702 variable to flush the UART at init time.
706 Depending on board, define exactly one serial port
707 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
708 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
709 console by defining CONFIG_8xx_CONS_NONE
711 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
712 port routines must be defined elsewhere
713 (i.e. serial_init(), serial_getc(), ...)
716 Enables console device for a color framebuffer. Needs following
717 defines (cf. smiLynxEM, i8042)
718 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
720 VIDEO_HW_RECTFILL graphic chip supports
723 VIDEO_HW_BITBLT graphic chip supports
724 bit-blit (cf. smiLynxEM)
725 VIDEO_VISIBLE_COLS visible pixel columns
727 VIDEO_VISIBLE_ROWS visible pixel rows
728 VIDEO_PIXEL_SIZE bytes per pixel
729 VIDEO_DATA_FORMAT graphic data format
730 (0-5, cf. cfb_console.c)
731 VIDEO_FB_ADRS framebuffer address
732 VIDEO_KBD_INIT_FCT keyboard int fct
733 (i.e. i8042_kbd_init())
734 VIDEO_TSTC_FCT test char fct
736 VIDEO_GETC_FCT get char fct
738 CONFIG_CONSOLE_CURSOR cursor drawing on/off
739 (requires blink timer
741 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
742 CONFIG_CONSOLE_TIME display time/date info in
744 (requires CONFIG_CMD_DATE)
745 CONFIG_VIDEO_LOGO display Linux logo in
747 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
748 linux_logo.h for logo.
749 Requires CONFIG_VIDEO_LOGO
750 CONFIG_CONSOLE_EXTRA_INFO
751 additional board info beside
754 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
755 a limited number of ANSI escape sequences (cursor control,
756 erase functions and limited graphics rendition control).
758 When CONFIG_CFB_CONSOLE is defined, video console is
759 default i/o. Serial console can be forced with
760 environment 'console=serial'.
762 When CONFIG_SILENT_CONSOLE is defined, all console
763 messages (by U-Boot and Linux!) can be silenced with
764 the "silent" environment variable. See
765 doc/README.silent for more information.
767 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
769 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
773 CONFIG_BAUDRATE - in bps
774 Select one of the baudrates listed in
775 CONFIG_SYS_BAUDRATE_TABLE, see below.
776 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
778 - Console Rx buffer length
779 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
780 the maximum receive buffer length for the SMC.
781 This option is actual only for 82xx and 8xx possible.
782 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
783 must be defined, to setup the maximum idle timeout for
786 - Pre-Console Buffer:
787 Prior to the console being initialised (i.e. serial UART
788 initialised etc) all console output is silently discarded.
789 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
790 buffer any console messages prior to the console being
791 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
792 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
793 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
794 bytes are output before the console is initialised, the
795 earlier bytes are discarded.
797 'Sane' compilers will generate smaller code if
798 CONFIG_PRE_CON_BUF_SZ is a power of 2
800 - Safe printf() functions
801 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
802 the printf() functions. These are defined in
803 include/vsprintf.h and include snprintf(), vsnprintf() and
804 so on. Code size increase is approximately 300-500 bytes.
805 If this option is not given then these functions will
806 silently discard their buffer size argument - this means
807 you are not getting any overflow checking in this case.
809 - Boot Delay: CONFIG_BOOTDELAY - in seconds
810 Delay before automatically booting the default image;
811 set to -1 to disable autoboot.
812 set to -2 to autoboot with no delay and not check for abort
813 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
815 See doc/README.autoboot for these options that
816 work with CONFIG_BOOTDELAY. None are required.
817 CONFIG_BOOT_RETRY_TIME
818 CONFIG_BOOT_RETRY_MIN
819 CONFIG_AUTOBOOT_KEYED
820 CONFIG_AUTOBOOT_PROMPT
821 CONFIG_AUTOBOOT_DELAY_STR
822 CONFIG_AUTOBOOT_STOP_STR
823 CONFIG_AUTOBOOT_DELAY_STR2
824 CONFIG_AUTOBOOT_STOP_STR2
825 CONFIG_ZERO_BOOTDELAY_CHECK
826 CONFIG_RESET_TO_RETRY
830 Only needed when CONFIG_BOOTDELAY is enabled;
831 define a command string that is automatically executed
832 when no character is read on the console interface
833 within "Boot Delay" after reset.
836 This can be used to pass arguments to the bootm
837 command. The value of CONFIG_BOOTARGS goes into the
838 environment value "bootargs".
840 CONFIG_RAMBOOT and CONFIG_NFSBOOT
841 The value of these goes into the environment as
842 "ramboot" and "nfsboot" respectively, and can be used
843 as a convenience, when switching between booting from
847 CONFIG_BOOTCOUNT_LIMIT
848 Implements a mechanism for detecting a repeating reboot
850 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
853 If no softreset save registers are found on the hardware
854 "bootcount" is stored in the environment. To prevent a
855 saveenv on all reboots, the environment variable
856 "upgrade_available" is used. If "upgrade_available" is
857 0, "bootcount" is always 0, if "upgrade_available" is
858 1 "bootcount" is incremented in the environment.
859 So the Userspace Applikation must set the "upgrade_available"
860 and "bootcount" variable to 0, if a boot was successfully.
865 When this option is #defined, the existence of the
866 environment variable "preboot" will be checked
867 immediately before starting the CONFIG_BOOTDELAY
868 countdown and/or running the auto-boot command resp.
869 entering interactive mode.
871 This feature is especially useful when "preboot" is
872 automatically generated or modified. For an example
873 see the LWMON board specific code: here "preboot" is
874 modified when the user holds down a certain
875 combination of keys on the (special) keyboard when
878 - Serial Download Echo Mode:
880 If defined to 1, all characters received during a
881 serial download (using the "loads" command) are
882 echoed back. This might be needed by some terminal
883 emulations (like "cu"), but may as well just take
884 time on others. This setting #define's the initial
885 value of the "loads_echo" environment variable.
887 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
889 Select one of the baudrates listed in
890 CONFIG_SYS_BAUDRATE_TABLE, see below.
893 Monitor commands can be included or excluded
894 from the build by using the #include files
895 <config_cmd_all.h> and #undef'ing unwanted
896 commands, or using <config_cmd_default.h>
897 and augmenting with additional #define's
900 The default command configuration includes all commands
901 except those marked below with a "*".
903 CONFIG_CMD_ASKENV * ask for env variable
904 CONFIG_CMD_BDI bdinfo
905 CONFIG_CMD_BEDBUG * Include BedBug Debugger
906 CONFIG_CMD_BMP * BMP support
907 CONFIG_CMD_BSP * Board specific commands
908 CONFIG_CMD_BOOTD bootd
909 CONFIG_CMD_CACHE * icache, dcache
910 CONFIG_CMD_CLK * clock command support
911 CONFIG_CMD_CONSOLE coninfo
912 CONFIG_CMD_CRC32 * crc32
913 CONFIG_CMD_DATE * support for RTC, date/time...
914 CONFIG_CMD_DHCP * DHCP support
915 CONFIG_CMD_DIAG * Diagnostics
916 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
917 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
918 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
919 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
920 CONFIG_CMD_DTT * Digital Therm and Thermostat
921 CONFIG_CMD_ECHO echo arguments
922 CONFIG_CMD_EDITENV edit env variable
923 CONFIG_CMD_EEPROM * EEPROM read/write support
924 CONFIG_CMD_ELF * bootelf, bootvx
925 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
926 CONFIG_CMD_ENV_FLAGS * display details about env flags
927 CONFIG_CMD_ENV_EXISTS * check existence of env variable
928 CONFIG_CMD_EXPORTENV * export the environment
929 CONFIG_CMD_EXT2 * ext2 command support
930 CONFIG_CMD_EXT4 * ext4 command support
931 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
932 that work for multiple fs types
933 CONFIG_CMD_SAVEENV saveenv
934 CONFIG_CMD_FDC * Floppy Disk Support
935 CONFIG_CMD_FAT * FAT command support
936 CONFIG_CMD_FLASH flinfo, erase, protect
937 CONFIG_CMD_FPGA FPGA device initialization support
938 CONFIG_CMD_FUSE * Device fuse support
939 CONFIG_CMD_GETTIME * Get time since boot
940 CONFIG_CMD_GO * the 'go' command (exec code)
941 CONFIG_CMD_GREPENV * search environment
942 CONFIG_CMD_HASH * calculate hash / digest
943 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
944 CONFIG_CMD_I2C * I2C serial bus support
945 CONFIG_CMD_IDE * IDE harddisk support
946 CONFIG_CMD_IMI iminfo
947 CONFIG_CMD_IMLS List all images found in NOR flash
948 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
949 CONFIG_CMD_IMMAP * IMMR dump support
950 CONFIG_CMD_IMPORTENV * import an environment
951 CONFIG_CMD_INI * import data from an ini file into the env
952 CONFIG_CMD_IRQ * irqinfo
953 CONFIG_CMD_ITEST Integer/string test of 2 values
954 CONFIG_CMD_JFFS2 * JFFS2 Support
955 CONFIG_CMD_KGDB * kgdb
956 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
957 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
959 CONFIG_CMD_LOADB loadb
960 CONFIG_CMD_LOADS loads
961 CONFIG_CMD_MD5SUM * print md5 message digest
962 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
963 CONFIG_CMD_MEMINFO * Display detailed memory information
964 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
966 CONFIG_CMD_MEMTEST * mtest
967 CONFIG_CMD_MISC Misc functions like sleep etc
968 CONFIG_CMD_MMC * MMC memory mapped support
969 CONFIG_CMD_MII * MII utility commands
970 CONFIG_CMD_MTDPARTS * MTD partition support
971 CONFIG_CMD_NAND * NAND support
972 CONFIG_CMD_NET bootp, tftpboot, rarpboot
973 CONFIG_CMD_NFS NFS support
974 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
975 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
976 CONFIG_CMD_PCI * pciinfo
977 CONFIG_CMD_PCMCIA * PCMCIA support
978 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
980 CONFIG_CMD_PORTIO * Port I/O
981 CONFIG_CMD_READ * Read raw data from partition
982 CONFIG_CMD_REGINFO * Register dump
983 CONFIG_CMD_RUN run command in env variable
984 CONFIG_CMD_SANDBOX * sb command to access sandbox features
985 CONFIG_CMD_SAVES * save S record dump
986 CONFIG_CMD_SCSI * SCSI Support
987 CONFIG_CMD_SDRAM * print SDRAM configuration information
988 (requires CONFIG_CMD_I2C)
989 CONFIG_CMD_SETGETDCR Support for DCR Register access
991 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
992 CONFIG_CMD_SHA1SUM * print sha1 memory digest
993 (requires CONFIG_CMD_MEMORY)
994 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
995 CONFIG_CMD_SOURCE "source" command Support
996 CONFIG_CMD_SPI * SPI serial bus support
997 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
998 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
999 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1000 CONFIG_CMD_TIMER * access to the system tick timer
1001 CONFIG_CMD_USB * USB support
1002 CONFIG_CMD_CDP * Cisco Discover Protocol support
1003 CONFIG_CMD_MFSL * Microblaze FSL support
1004 CONFIG_CMD_XIMG Load part of Multi Image
1007 EXAMPLE: If you want all functions except of network
1008 support you can write:
1010 #include "config_cmd_all.h"
1011 #undef CONFIG_CMD_NET
1014 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1016 Note: Don't enable the "icache" and "dcache" commands
1017 (configuration option CONFIG_CMD_CACHE) unless you know
1018 what you (and your U-Boot users) are doing. Data
1019 cache cannot be enabled on systems like the 8xx or
1020 8260 (where accesses to the IMMR region must be
1021 uncached), and it cannot be disabled on all other
1022 systems where we (mis-) use the data cache to hold an
1023 initial stack and some data.
1026 XXX - this list needs to get updated!
1028 - Regular expression support:
1030 If this variable is defined, U-Boot is linked against
1031 the SLRE (Super Light Regular Expression) library,
1032 which adds regex support to some commands, as for
1033 example "env grep" and "setexpr".
1037 If this variable is defined, U-Boot will use a device tree
1038 to configure its devices, instead of relying on statically
1039 compiled #defines in the board file. This option is
1040 experimental and only available on a few boards. The device
1041 tree is available in the global data as gd->fdt_blob.
1043 U-Boot needs to get its device tree from somewhere. This can
1044 be done using one of the two options below:
1047 If this variable is defined, U-Boot will embed a device tree
1048 binary in its image. This device tree file should be in the
1049 board directory and called <soc>-<board>.dts. The binary file
1050 is then picked up in board_init_f() and made available through
1051 the global data structure as gd->blob.
1054 If this variable is defined, U-Boot will build a device tree
1055 binary. It will be called u-boot.dtb. Architecture-specific
1056 code will locate it at run-time. Generally this works by:
1058 cat u-boot.bin u-boot.dtb >image.bin
1060 and in fact, U-Boot does this for you, creating a file called
1061 u-boot-dtb.bin which is useful in the common case. You can
1062 still use the individual files if you need something more
1067 If this variable is defined, it enables watchdog
1068 support for the SoC. There must be support in the SoC
1069 specific code for a watchdog. For the 8xx and 8260
1070 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1071 register. When supported for a specific SoC is
1072 available, then no further board specific code should
1073 be needed to use it.
1076 When using a watchdog circuitry external to the used
1077 SoC, then define this variable and provide board
1078 specific code for the "hw_watchdog_reset" function.
1081 CONFIG_VERSION_VARIABLE
1082 If this variable is defined, an environment variable
1083 named "ver" is created by U-Boot showing the U-Boot
1084 version as printed by the "version" command.
1085 Any change to this variable will be reverted at the
1090 When CONFIG_CMD_DATE is selected, the type of the RTC
1091 has to be selected, too. Define exactly one of the
1094 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1095 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1096 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1097 CONFIG_RTC_MC146818 - use MC146818 RTC
1098 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1099 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1100 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1101 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1102 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1103 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1104 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1105 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1108 Note that if the RTC uses I2C, then the I2C interface
1109 must also be configured. See I2C Support, below.
1112 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1114 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1115 chip-ngpio pairs that tell the PCA953X driver the number of
1116 pins supported by a particular chip.
1118 Note that if the GPIO device uses I2C, then the I2C interface
1119 must also be configured. See I2C Support, below.
1121 - Timestamp Support:
1123 When CONFIG_TIMESTAMP is selected, the timestamp
1124 (date and time) of an image is printed by image
1125 commands like bootm or iminfo. This option is
1126 automatically enabled when you select CONFIG_CMD_DATE .
1128 - Partition Labels (disklabels) Supported:
1129 Zero or more of the following:
1130 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1131 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1132 Intel architecture, USB sticks, etc.
1133 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1134 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1135 bootloader. Note 2TB partition limit; see
1137 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1139 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1140 CONFIG_CMD_SCSI) you must configure support for at
1141 least one non-MTD partition type as well.
1144 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1145 board configurations files but used nowhere!
1147 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1148 be performed by calling the function
1149 ide_set_reset(int reset)
1150 which has to be defined in a board specific file
1155 Set this to enable ATAPI support.
1160 Set this to enable support for disks larger than 137GB
1161 Also look at CONFIG_SYS_64BIT_LBA.
1162 Whithout these , LBA48 support uses 32bit variables and will 'only'
1163 support disks up to 2.1TB.
1165 CONFIG_SYS_64BIT_LBA:
1166 When enabled, makes the IDE subsystem use 64bit sector addresses.
1170 At the moment only there is only support for the
1171 SYM53C8XX SCSI controller; define
1172 CONFIG_SCSI_SYM53C8XX to enable it.
1174 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1175 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1176 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1177 maximum numbers of LUNs, SCSI ID's and target
1179 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1181 The environment variable 'scsidevs' is set to the number of
1182 SCSI devices found during the last scan.
1184 - NETWORK Support (PCI):
1186 Support for Intel 8254x/8257x gigabit chips.
1189 Utility code for direct access to the SPI bus on Intel 8257x.
1190 This does not do anything useful unless you set at least one
1191 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1193 CONFIG_E1000_SPI_GENERIC
1194 Allow generic access to the SPI bus on the Intel 8257x, for
1195 example with the "sspi" command.
1198 Management command for E1000 devices. When used on devices
1199 with SPI support you can reprogram the EEPROM from U-Boot.
1201 CONFIG_E1000_FALLBACK_MAC
1202 default MAC for empty EEPROM after production.
1205 Support for Intel 82557/82559/82559ER chips.
1206 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1207 write routine for first time initialisation.
1210 Support for Digital 2114x chips.
1211 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1212 modem chip initialisation (KS8761/QS6611).
1215 Support for National dp83815 chips.
1218 Support for National dp8382[01] gigabit chips.
1220 - NETWORK Support (other):
1222 CONFIG_DRIVER_AT91EMAC
1223 Support for AT91RM9200 EMAC.
1226 Define this to use reduced MII inteface
1228 CONFIG_DRIVER_AT91EMAC_QUIET
1229 If this defined, the driver is quiet.
1230 The driver doen't show link status messages.
1232 CONFIG_CALXEDA_XGMAC
1233 Support for the Calxeda XGMAC device
1236 Support for SMSC's LAN91C96 chips.
1238 CONFIG_LAN91C96_BASE
1239 Define this to hold the physical address
1240 of the LAN91C96's I/O space
1242 CONFIG_LAN91C96_USE_32_BIT
1243 Define this to enable 32 bit addressing
1246 Support for SMSC's LAN91C111 chip
1248 CONFIG_SMC91111_BASE
1249 Define this to hold the physical address
1250 of the device (I/O space)
1252 CONFIG_SMC_USE_32_BIT
1253 Define this if data bus is 32 bits
1255 CONFIG_SMC_USE_IOFUNCS
1256 Define this to use i/o functions instead of macros
1257 (some hardware wont work with macros)
1259 CONFIG_DRIVER_TI_EMAC
1260 Support for davinci emac
1262 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1263 Define this if you have more then 3 PHYs.
1266 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1268 CONFIG_FTGMAC100_EGIGA
1269 Define this to use GE link update with gigabit PHY.
1270 Define this if FTGMAC100 is connected to gigabit PHY.
1271 If your system has 10/100 PHY only, it might not occur
1272 wrong behavior. Because PHY usually return timeout or
1273 useless data when polling gigabit status and gigabit
1274 control registers. This behavior won't affect the
1275 correctnessof 10/100 link speed update.
1278 Support for SMSC's LAN911x and LAN921x chips
1281 Define this to hold the physical address
1282 of the device (I/O space)
1284 CONFIG_SMC911X_32_BIT
1285 Define this if data bus is 32 bits
1287 CONFIG_SMC911X_16_BIT
1288 Define this if data bus is 16 bits. If your processor
1289 automatically converts one 32 bit word to two 16 bit
1290 words you may also try CONFIG_SMC911X_32_BIT.
1293 Support for Renesas on-chip Ethernet controller
1295 CONFIG_SH_ETHER_USE_PORT
1296 Define the number of ports to be used
1298 CONFIG_SH_ETHER_PHY_ADDR
1299 Define the ETH PHY's address
1301 CONFIG_SH_ETHER_CACHE_WRITEBACK
1302 If this option is set, the driver enables cache flush.
1306 Support TPM devices.
1309 Support for i2c bus TPM devices. Only one device
1310 per system is supported at this time.
1312 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1313 Define the the i2c bus number for the TPM device
1315 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1316 Define the TPM's address on the i2c bus
1318 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1319 Define the burst count bytes upper limit
1321 CONFIG_TPM_ATMEL_TWI
1322 Support for Atmel TWI TPM device. Requires I2C support.
1325 Support for generic parallel port TPM devices. Only one device
1326 per system is supported at this time.
1328 CONFIG_TPM_TIS_BASE_ADDRESS
1329 Base address where the generic TPM device is mapped
1330 to. Contemporary x86 systems usually map it at
1334 Add tpm monitor functions.
1335 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1336 provides monitor access to authorized functions.
1339 Define this to enable the TPM support library which provides
1340 functional interfaces to some TPM commands.
1341 Requires support for a TPM device.
1343 CONFIG_TPM_AUTH_SESSIONS
1344 Define this to enable authorized functions in the TPM library.
1345 Requires CONFIG_TPM and CONFIG_SHA1.
1348 At the moment only the UHCI host controller is
1349 supported (PIP405, MIP405, MPC5200); define
1350 CONFIG_USB_UHCI to enable it.
1351 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1352 and define CONFIG_USB_STORAGE to enable the USB
1355 Supported are USB Keyboards and USB Floppy drives
1357 MPC5200 USB requires additional defines:
1359 for 528 MHz Clock: 0x0001bbbb
1363 for differential drivers: 0x00001000
1364 for single ended drivers: 0x00005000
1365 for differential drivers on PSC3: 0x00000100
1366 for single ended drivers on PSC3: 0x00004100
1367 CONFIG_SYS_USB_EVENT_POLL
1368 May be defined to allow interrupt polling
1369 instead of using asynchronous interrupts
1371 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1372 txfilltuning field in the EHCI controller on reset.
1374 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1375 interval for usb hub power-on delay.(minimum 100msec)
1378 Define the below if you wish to use the USB console.
1379 Once firmware is rebuilt from a serial console issue the
1380 command "setenv stdin usbtty; setenv stdout usbtty" and
1381 attach your USB cable. The Unix command "dmesg" should print
1382 it has found a new device. The environment variable usbtty
1383 can be set to gserial or cdc_acm to enable your device to
1384 appear to a USB host as a Linux gserial device or a
1385 Common Device Class Abstract Control Model serial device.
1386 If you select usbtty = gserial you should be able to enumerate
1388 # modprobe usbserial vendor=0xVendorID product=0xProductID
1389 else if using cdc_acm, simply setting the environment
1390 variable usbtty to be cdc_acm should suffice. The following
1391 might be defined in YourBoardName.h
1394 Define this to build a UDC device
1397 Define this to have a tty type of device available to
1398 talk to the UDC device
1401 Define this to enable the high speed support for usb
1402 device and usbtty. If this feature is enabled, a routine
1403 int is_usbd_high_speed(void)
1404 also needs to be defined by the driver to dynamically poll
1405 whether the enumeration has succeded at high speed or full
1408 CONFIG_SYS_CONSOLE_IS_IN_ENV
1409 Define this if you want stdin, stdout &/or stderr to
1413 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1414 Derive USB clock from external clock "blah"
1415 - CONFIG_SYS_USB_EXTC_CLK 0x02
1417 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1418 Derive USB clock from brgclk
1419 - CONFIG_SYS_USB_BRG_CLK 0x04
1421 If you have a USB-IF assigned VendorID then you may wish to
1422 define your own vendor specific values either in BoardName.h
1423 or directly in usbd_vendor_info.h. If you don't define
1424 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1425 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1426 should pretend to be a Linux device to it's target host.
1428 CONFIG_USBD_MANUFACTURER
1429 Define this string as the name of your company for
1430 - CONFIG_USBD_MANUFACTURER "my company"
1432 CONFIG_USBD_PRODUCT_NAME
1433 Define this string as the name of your product
1434 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1436 CONFIG_USBD_VENDORID
1437 Define this as your assigned Vendor ID from the USB
1438 Implementors Forum. This *must* be a genuine Vendor ID
1439 to avoid polluting the USB namespace.
1440 - CONFIG_USBD_VENDORID 0xFFFF
1442 CONFIG_USBD_PRODUCTID
1443 Define this as the unique Product ID
1445 - CONFIG_USBD_PRODUCTID 0xFFFF
1447 Some USB device drivers may need to check USB cable attachment.
1448 In this case you can enable following config in BoardName.h:
1449 CONFIG_USB_CABLE_CHECK
1450 This enables function definition:
1451 - usb_cable_connected() in include/usb.h
1452 Implementation of this function is board-specific.
1454 - ULPI Layer Support:
1455 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1456 the generic ULPI layer. The generic layer accesses the ULPI PHY
1457 via the platform viewport, so you need both the genric layer and
1458 the viewport enabled. Currently only Chipidea/ARC based
1459 viewport is supported.
1460 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1461 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1462 If your ULPI phy needs a different reference clock than the
1463 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1464 the appropriate value in Hz.
1467 The MMC controller on the Intel PXA is supported. To
1468 enable this define CONFIG_MMC. The MMC can be
1469 accessed from the boot prompt by mapping the device
1470 to physical memory similar to flash. Command line is
1471 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1472 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1475 Support for Renesas on-chip MMCIF controller
1477 CONFIG_SH_MMCIF_ADDR
1478 Define the base address of MMCIF registers
1481 Define the clock frequency for MMCIF
1483 - USB Device Firmware Update (DFU) class support:
1485 This enables the USB portion of the DFU USB class
1488 This enables the command "dfu" which is used to have
1489 U-Boot create a DFU class device via USB. This command
1490 requires that the "dfu_alt_info" environment variable be
1491 set and define the alt settings to expose to the host.
1494 This enables support for exposing (e)MMC devices via DFU.
1497 This enables support for exposing NAND devices via DFU.
1500 This enables support for exposing RAM via DFU.
1501 Note: DFU spec refer to non-volatile memory usage, but
1502 allow usages beyond the scope of spec - here RAM usage,
1503 one that would help mostly the developer.
1505 CONFIG_SYS_DFU_DATA_BUF_SIZE
1506 Dfu transfer uses a buffer before writing data to the
1507 raw storage device. Make the size (in bytes) of this buffer
1508 configurable. The size of this buffer is also configurable
1509 through the "dfu_bufsiz" environment variable.
1511 CONFIG_SYS_DFU_MAX_FILE_SIZE
1512 When updating files rather than the raw storage device,
1513 we use a static buffer to copy the file into and then write
1514 the buffer once we've been given the whole file. Define
1515 this to the maximum filesize (in bytes) for the buffer.
1516 Default is 4 MiB if undefined.
1518 - Journaling Flash filesystem support:
1519 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1520 CONFIG_JFFS2_NAND_DEV
1521 Define these for a default partition on a NAND device
1523 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1524 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1525 Define these for a default partition on a NOR device
1527 CONFIG_SYS_JFFS_CUSTOM_PART
1528 Define this to create an own partition. You have to provide a
1529 function struct part_info* jffs2_part_info(int part_num)
1531 If you define only one JFFS2 partition you may also want to
1532 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1533 to disable the command chpart. This is the default when you
1534 have not defined a custom partition
1536 - FAT(File Allocation Table) filesystem write function support:
1539 Define this to enable support for saving memory data as a
1540 file in FAT formatted partition.
1542 This will also enable the command "fatwrite" enabling the
1543 user to write files to FAT.
1545 CBFS (Coreboot Filesystem) support
1548 Define this to enable support for reading from a Coreboot
1549 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1555 Define this to enable standard (PC-Style) keyboard
1559 Standard PC keyboard driver with US (is default) and
1560 GERMAN key layout (switch via environment 'keymap=de') support.
1561 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1562 for cfb_console. Supports cursor blinking.
1565 Enables a Chrome OS keyboard using the CROS_EC interface.
1566 This uses CROS_EC to communicate with a second microcontroller
1567 which provides key scans on request.
1572 Define this to enable video support (for output to
1575 CONFIG_VIDEO_CT69000
1577 Enable Chips & Technologies 69000 Video chip
1579 CONFIG_VIDEO_SMI_LYNXEM
1580 Enable Silicon Motion SMI 712/710/810 Video chip. The
1581 video output is selected via environment 'videoout'
1582 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1585 For the CT69000 and SMI_LYNXEM drivers, videomode is
1586 selected via environment 'videomode'. Two different ways
1588 - "videomode=num" 'num' is a standard LiLo mode numbers.
1589 Following standard modes are supported (* is default):
1591 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1592 -------------+---------------------------------------------
1593 8 bits | 0x301* 0x303 0x305 0x161 0x307
1594 15 bits | 0x310 0x313 0x316 0x162 0x319
1595 16 bits | 0x311 0x314 0x317 0x163 0x31A
1596 24 bits | 0x312 0x315 0x318 ? 0x31B
1597 -------------+---------------------------------------------
1598 (i.e. setenv videomode 317; saveenv; reset;)
1600 - "videomode=bootargs" all the video parameters are parsed
1601 from the bootargs. (See drivers/video/videomodes.c)
1604 CONFIG_VIDEO_SED13806
1605 Enable Epson SED13806 driver. This driver supports 8bpp
1606 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1607 or CONFIG_VIDEO_SED13806_16BPP
1610 Enable the Freescale DIU video driver. Reference boards for
1611 SOCs that have a DIU should define this macro to enable DIU
1612 support, and should also define these other macros:
1618 CONFIG_VIDEO_SW_CURSOR
1619 CONFIG_VGA_AS_SINGLE_DEVICE
1621 CONFIG_VIDEO_BMP_LOGO
1623 The DIU driver will look for the 'video-mode' environment
1624 variable, and if defined, enable the DIU as a console during
1625 boot. See the documentation file README.video for a
1626 description of this variable.
1630 Enable the VGA video / BIOS for x86. The alternative if you
1631 are using coreboot is to use the coreboot frame buffer
1638 Define this to enable a custom keyboard support.
1639 This simply calls drv_keyboard_init() which must be
1640 defined in your board-specific files.
1641 The only board using this so far is RBC823.
1643 - LCD Support: CONFIG_LCD
1645 Define this to enable LCD support (for output to LCD
1646 display); also select one of the supported displays
1647 by defining one of these:
1651 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1653 CONFIG_NEC_NL6448AC33:
1655 NEC NL6448AC33-18. Active, color, single scan.
1657 CONFIG_NEC_NL6448BC20
1659 NEC NL6448BC20-08. 6.5", 640x480.
1660 Active, color, single scan.
1662 CONFIG_NEC_NL6448BC33_54
1664 NEC NL6448BC33-54. 10.4", 640x480.
1665 Active, color, single scan.
1669 Sharp 320x240. Active, color, single scan.
1670 It isn't 16x9, and I am not sure what it is.
1672 CONFIG_SHARP_LQ64D341
1674 Sharp LQ64D341 display, 640x480.
1675 Active, color, single scan.
1679 HLD1045 display, 640x480.
1680 Active, color, single scan.
1684 Optrex CBL50840-2 NF-FW 99 22 M5
1686 Hitachi LMG6912RPFC-00T
1690 320x240. Black & white.
1692 Normally display is black on white background; define
1693 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1695 CONFIG_LCD_ALIGNMENT
1697 Normally the LCD is page-aligned (tyically 4KB). If this is
1698 defined then the LCD will be aligned to this value instead.
1699 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1700 here, since it is cheaper to change data cache settings on
1701 a per-section basis.
1703 CONFIG_CONSOLE_SCROLL_LINES
1705 When the console need to be scrolled, this is the number of
1706 lines to scroll by. It defaults to 1. Increasing this makes
1707 the console jump but can help speed up operation when scrolling
1712 Support drawing of RLE8-compressed bitmaps on the LCD.
1716 Enables an 'i2c edid' command which can read EDID
1717 information over I2C from an attached LCD display.
1719 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1721 If this option is set, the environment is checked for
1722 a variable "splashimage". If found, the usual display
1723 of logo, copyright and system information on the LCD
1724 is suppressed and the BMP image at the address
1725 specified in "splashimage" is loaded instead. The
1726 console is redirected to the "nulldev", too. This
1727 allows for a "silent" boot where a splash screen is
1728 loaded very quickly after power-on.
1730 CONFIG_SPLASHIMAGE_GUARD
1732 If this option is set, then U-Boot will prevent the environment
1733 variable "splashimage" from being set to a problematic address
1734 (see README.displaying-bmps and README.arm-unaligned-accesses).
1735 This option is useful for targets where, due to alignment
1736 restrictions, an improperly aligned BMP image will cause a data
1737 abort. If you think you will not have problems with unaligned
1738 accesses (for example because your toolchain prevents them)
1739 there is no need to set this option.
1741 CONFIG_SPLASH_SCREEN_ALIGN
1743 If this option is set the splash image can be freely positioned
1744 on the screen. Environment variable "splashpos" specifies the
1745 position as "x,y". If a positive number is given it is used as
1746 number of pixel from left/top. If a negative number is given it
1747 is used as number of pixel from right/bottom. You can also
1748 specify 'm' for centering the image.
1751 setenv splashpos m,m
1752 => image at center of screen
1754 setenv splashpos 30,20
1755 => image at x = 30 and y = 20
1757 setenv splashpos -10,m
1758 => vertically centered image
1759 at x = dspWidth - bmpWidth - 9
1761 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1763 If this option is set, additionally to standard BMP
1764 images, gzipped BMP images can be displayed via the
1765 splashscreen support or the bmp command.
1767 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1769 If this option is set, 8-bit RLE compressed BMP images
1770 can be displayed via the splashscreen support or the
1773 - Do compresssing for memory range:
1776 If this option is set, it would use zlib deflate method
1777 to compress the specified memory at its best effort.
1779 - Compression support:
1782 Enabled by default to support gzip compressed images.
1786 If this option is set, support for bzip2 compressed
1787 images is included. If not, only uncompressed and gzip
1788 compressed images are supported.
1790 NOTE: the bzip2 algorithm requires a lot of RAM, so
1791 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1796 If this option is set, support for lzma compressed
1799 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1800 requires an amount of dynamic memory that is given by the
1803 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1805 Where lc and lp stand for, respectively, Literal context bits
1806 and Literal pos bits.
1808 This value is upper-bounded by 14MB in the worst case. Anyway,
1809 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1810 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1811 a very small buffer.
1813 Use the lzmainfo tool to determinate the lc and lp values and
1814 then calculate the amount of needed dynamic memory (ensuring
1815 the appropriate CONFIG_SYS_MALLOC_LEN value).
1819 If this option is set, support for LZO compressed images
1825 The address of PHY on MII bus.
1827 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1829 The clock frequency of the MII bus
1833 If this option is set, support for speed/duplex
1834 detection of gigabit PHY is included.
1836 CONFIG_PHY_RESET_DELAY
1838 Some PHY like Intel LXT971A need extra delay after
1839 reset before any MII register access is possible.
1840 For such PHY, set this option to the usec delay
1841 required. (minimum 300usec for LXT971A)
1843 CONFIG_PHY_CMD_DELAY (ppc4xx)
1845 Some PHY like Intel LXT971A need extra delay after
1846 command issued before MII status register can be read
1856 Define a default value for Ethernet address to use
1857 for the respective Ethernet interface, in case this
1858 is not determined automatically.
1863 Define a default value for the IP address to use for
1864 the default Ethernet interface, in case this is not
1865 determined through e.g. bootp.
1866 (Environment variable "ipaddr")
1868 - Server IP address:
1871 Defines a default value for the IP address of a TFTP
1872 server to contact when using the "tftboot" command.
1873 (Environment variable "serverip")
1875 CONFIG_KEEP_SERVERADDR
1877 Keeps the server's MAC address, in the env 'serveraddr'
1878 for passing to bootargs (like Linux's netconsole option)
1880 - Gateway IP address:
1883 Defines a default value for the IP address of the
1884 default router where packets to other networks are
1886 (Environment variable "gatewayip")
1891 Defines a default value for the subnet mask (or
1892 routing prefix) which is used to determine if an IP
1893 address belongs to the local subnet or needs to be
1894 forwarded through a router.
1895 (Environment variable "netmask")
1897 - Multicast TFTP Mode:
1900 Defines whether you want to support multicast TFTP as per
1901 rfc-2090; for example to work with atftp. Lets lots of targets
1902 tftp down the same boot image concurrently. Note: the Ethernet
1903 driver in use must provide a function: mcast() to join/leave a
1906 - BOOTP Recovery Mode:
1907 CONFIG_BOOTP_RANDOM_DELAY
1909 If you have many targets in a network that try to
1910 boot using BOOTP, you may want to avoid that all
1911 systems send out BOOTP requests at precisely the same
1912 moment (which would happen for instance at recovery
1913 from a power failure, when all systems will try to
1914 boot, thus flooding the BOOTP server. Defining
1915 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1916 inserted before sending out BOOTP requests. The
1917 following delays are inserted then:
1919 1st BOOTP request: delay 0 ... 1 sec
1920 2nd BOOTP request: delay 0 ... 2 sec
1921 3rd BOOTP request: delay 0 ... 4 sec
1923 BOOTP requests: delay 0 ... 8 sec
1925 - DHCP Advanced Options:
1926 You can fine tune the DHCP functionality by defining
1927 CONFIG_BOOTP_* symbols:
1929 CONFIG_BOOTP_SUBNETMASK
1930 CONFIG_BOOTP_GATEWAY
1931 CONFIG_BOOTP_HOSTNAME
1932 CONFIG_BOOTP_NISDOMAIN
1933 CONFIG_BOOTP_BOOTPATH
1934 CONFIG_BOOTP_BOOTFILESIZE
1937 CONFIG_BOOTP_SEND_HOSTNAME
1938 CONFIG_BOOTP_NTPSERVER
1939 CONFIG_BOOTP_TIMEOFFSET
1940 CONFIG_BOOTP_VENDOREX
1941 CONFIG_BOOTP_MAY_FAIL
1943 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1944 environment variable, not the BOOTP server.
1946 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1947 after the configured retry count, the call will fail
1948 instead of starting over. This can be used to fail over
1949 to Link-local IP address configuration if the DHCP server
1952 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1953 serverip from a DHCP server, it is possible that more
1954 than one DNS serverip is offered to the client.
1955 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1956 serverip will be stored in the additional environment
1957 variable "dnsip2". The first DNS serverip is always
1958 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1961 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1962 to do a dynamic update of a DNS server. To do this, they
1963 need the hostname of the DHCP requester.
1964 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1965 of the "hostname" environment variable is passed as
1966 option 12 to the DHCP server.
1968 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1970 A 32bit value in microseconds for a delay between
1971 receiving a "DHCP Offer" and sending the "DHCP Request".
1972 This fixes a problem with certain DHCP servers that don't
1973 respond 100% of the time to a "DHCP request". E.g. On an
1974 AT91RM9200 processor running at 180MHz, this delay needed
1975 to be *at least* 15,000 usec before a Windows Server 2003
1976 DHCP server would reply 100% of the time. I recommend at
1977 least 50,000 usec to be safe. The alternative is to hope
1978 that one of the retries will be successful but note that
1979 the DHCP timeout and retry process takes a longer than
1982 - Link-local IP address negotiation:
1983 Negotiate with other link-local clients on the local network
1984 for an address that doesn't require explicit configuration.
1985 This is especially useful if a DHCP server cannot be guaranteed
1986 to exist in all environments that the device must operate.
1988 See doc/README.link-local for more information.
1991 CONFIG_CDP_DEVICE_ID
1993 The device id used in CDP trigger frames.
1995 CONFIG_CDP_DEVICE_ID_PREFIX
1997 A two character string which is prefixed to the MAC address
2002 A printf format string which contains the ascii name of
2003 the port. Normally is set to "eth%d" which sets
2004 eth0 for the first Ethernet, eth1 for the second etc.
2006 CONFIG_CDP_CAPABILITIES
2008 A 32bit integer which indicates the device capabilities;
2009 0x00000010 for a normal host which does not forwards.
2013 An ascii string containing the version of the software.
2017 An ascii string containing the name of the platform.
2021 A 32bit integer sent on the trigger.
2023 CONFIG_CDP_POWER_CONSUMPTION
2025 A 16bit integer containing the power consumption of the
2026 device in .1 of milliwatts.
2028 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2030 A byte containing the id of the VLAN.
2032 - Status LED: CONFIG_STATUS_LED
2034 Several configurations allow to display the current
2035 status using a LED. For instance, the LED will blink
2036 fast while running U-Boot code, stop blinking as
2037 soon as a reply to a BOOTP request was received, and
2038 start blinking slow once the Linux kernel is running
2039 (supported by a status LED driver in the Linux
2040 kernel). Defining CONFIG_STATUS_LED enables this
2046 The status LED can be connected to a GPIO pin.
2047 In such cases, the gpio_led driver can be used as a
2048 status LED backend implementation. Define CONFIG_GPIO_LED
2049 to include the gpio_led driver in the U-Boot binary.
2051 CONFIG_GPIO_LED_INVERTED_TABLE
2052 Some GPIO connected LEDs may have inverted polarity in which
2053 case the GPIO high value corresponds to LED off state and
2054 GPIO low value corresponds to LED on state.
2055 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2056 with a list of GPIO LEDs that have inverted polarity.
2058 - CAN Support: CONFIG_CAN_DRIVER
2060 Defining CONFIG_CAN_DRIVER enables CAN driver support
2061 on those systems that support this (optional)
2062 feature, like the TQM8xxL modules.
2064 - I2C Support: CONFIG_SYS_I2C
2066 This enable the NEW i2c subsystem, and will allow you to use
2067 i2c commands at the u-boot command line (as long as you set
2068 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2069 based realtime clock chips or other i2c devices. See
2070 common/cmd_i2c.c for a description of the command line
2073 ported i2c driver to the new framework:
2074 - drivers/i2c/soft_i2c.c:
2075 - activate first bus with CONFIG_SYS_I2C_SOFT define
2076 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2077 for defining speed and slave address
2078 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2079 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2080 for defining speed and slave address
2081 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2082 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2083 for defining speed and slave address
2084 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2085 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2086 for defining speed and slave address
2088 - drivers/i2c/fsl_i2c.c:
2089 - activate i2c driver with CONFIG_SYS_I2C_FSL
2090 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2091 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2092 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2094 - If your board supports a second fsl i2c bus, define
2095 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2096 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2097 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2100 - drivers/i2c/tegra_i2c.c:
2101 - activate this driver with CONFIG_SYS_I2C_TEGRA
2102 - This driver adds 4 i2c buses with a fix speed from
2103 100000 and the slave addr 0!
2105 - drivers/i2c/ppc4xx_i2c.c
2106 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2107 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2108 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2110 - drivers/i2c/i2c_mxc.c
2111 - activate this driver with CONFIG_SYS_I2C_MXC
2112 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2113 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2114 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2115 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2116 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2117 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2118 If thoses defines are not set, default value is 100000
2119 for speed, and 0 for slave.
2121 - drivers/i2c/rcar_i2c.c:
2122 - activate this driver with CONFIG_SYS_I2C_RCAR
2123 - This driver adds 4 i2c buses
2125 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2126 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2127 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2128 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2129 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2130 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2131 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2132 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2133 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2135 - drivers/i2c/sh_i2c.c:
2136 - activate this driver with CONFIG_SYS_I2C_SH
2137 - This driver adds from 2 to 5 i2c buses
2139 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2140 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2141 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2142 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2143 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2144 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2145 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2146 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2147 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2148 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2149 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2150 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2151 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2153 - drivers/i2c/omap24xx_i2c.c
2154 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2155 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2156 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2157 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2158 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2159 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2160 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2161 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2162 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2163 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2164 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2166 - drivers/i2c/zynq_i2c.c
2167 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2168 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2169 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2171 - drivers/i2c/s3c24x0_i2c.c:
2172 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2173 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2174 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2175 with a fix speed from 100000 and the slave addr 0!
2179 CONFIG_SYS_NUM_I2C_BUSES
2180 Hold the number of i2c busses you want to use. If you
2181 don't use/have i2c muxes on your i2c bus, this
2182 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2185 CONFIG_SYS_I2C_DIRECT_BUS
2186 define this, if you don't use i2c muxes on your hardware.
2187 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2190 CONFIG_SYS_I2C_MAX_HOPS
2191 define how many muxes are maximal consecutively connected
2192 on one i2c bus. If you not use i2c muxes, omit this
2195 CONFIG_SYS_I2C_BUSES
2196 hold a list of busses you want to use, only used if
2197 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2198 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2199 CONFIG_SYS_NUM_I2C_BUSES = 9:
2201 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2202 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2203 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2204 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2205 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2206 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2207 {1, {I2C_NULL_HOP}}, \
2208 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2209 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2213 bus 0 on adapter 0 without a mux
2214 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2215 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2216 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2217 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2218 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2219 bus 6 on adapter 1 without a mux
2220 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2221 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2223 If you do not have i2c muxes on your board, omit this define.
2225 - Legacy I2C Support: CONFIG_HARD_I2C
2227 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2228 provides the following compelling advantages:
2230 - more than one i2c adapter is usable
2231 - approved multibus support
2232 - better i2c mux support
2234 ** Please consider updating your I2C driver now. **
2236 These enable legacy I2C serial bus commands. Defining
2237 CONFIG_HARD_I2C will include the appropriate I2C driver
2238 for the selected CPU.
2240 This will allow you to use i2c commands at the u-boot
2241 command line (as long as you set CONFIG_CMD_I2C in
2242 CONFIG_COMMANDS) and communicate with i2c based realtime
2243 clock chips. See common/cmd_i2c.c for a description of the
2244 command line interface.
2246 CONFIG_HARD_I2C selects a hardware I2C controller.
2248 There are several other quantities that must also be
2249 defined when you define CONFIG_HARD_I2C.
2251 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2252 to be the frequency (in Hz) at which you wish your i2c bus
2253 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2254 the CPU's i2c node address).
2256 Now, the u-boot i2c code for the mpc8xx
2257 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2258 and so its address should therefore be cleared to 0 (See,
2259 eg, MPC823e User's Manual p.16-473). So, set
2260 CONFIG_SYS_I2C_SLAVE to 0.
2262 CONFIG_SYS_I2C_INIT_MPC5XXX
2264 When a board is reset during an i2c bus transfer
2265 chips might think that the current transfer is still
2266 in progress. Reset the slave devices by sending start
2267 commands until the slave device responds.
2269 That's all that's required for CONFIG_HARD_I2C.
2271 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2272 then the following macros need to be defined (examples are
2273 from include/configs/lwmon.h):
2277 (Optional). Any commands necessary to enable the I2C
2278 controller or configure ports.
2280 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2284 (Only for MPC8260 CPU). The I/O port to use (the code
2285 assumes both bits are on the same port). Valid values
2286 are 0..3 for ports A..D.
2290 The code necessary to make the I2C data line active
2291 (driven). If the data line is open collector, this
2294 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2298 The code necessary to make the I2C data line tri-stated
2299 (inactive). If the data line is open collector, this
2302 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2306 Code that returns true if the I2C data line is high,
2309 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2313 If <bit> is true, sets the I2C data line high. If it
2314 is false, it clears it (low).
2316 eg: #define I2C_SDA(bit) \
2317 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2318 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2322 If <bit> is true, sets the I2C clock line high. If it
2323 is false, it clears it (low).
2325 eg: #define I2C_SCL(bit) \
2326 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2327 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2331 This delay is invoked four times per clock cycle so this
2332 controls the rate of data transfer. The data rate thus
2333 is 1 / (I2C_DELAY * 4). Often defined to be something
2336 #define I2C_DELAY udelay(2)
2338 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2340 If your arch supports the generic GPIO framework (asm/gpio.h),
2341 then you may alternatively define the two GPIOs that are to be
2342 used as SCL / SDA. Any of the previous I2C_xxx macros will
2343 have GPIO-based defaults assigned to them as appropriate.
2345 You should define these to the GPIO value as given directly to
2346 the generic GPIO functions.
2348 CONFIG_SYS_I2C_INIT_BOARD
2350 When a board is reset during an i2c bus transfer
2351 chips might think that the current transfer is still
2352 in progress. On some boards it is possible to access
2353 the i2c SCLK line directly, either by using the
2354 processor pin as a GPIO or by having a second pin
2355 connected to the bus. If this option is defined a
2356 custom i2c_init_board() routine in boards/xxx/board.c
2357 is run early in the boot sequence.
2359 CONFIG_SYS_I2C_BOARD_LATE_INIT
2361 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2362 defined a custom i2c_board_late_init() routine in
2363 boards/xxx/board.c is run AFTER the operations in i2c_init()
2364 is completed. This callpoint can be used to unreset i2c bus
2365 using CPU i2c controller register accesses for CPUs whose i2c
2366 controller provide such a method. It is called at the end of
2367 i2c_init() to allow i2c_init operations to setup the i2c bus
2368 controller on the CPU (e.g. setting bus speed & slave address).
2370 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2372 This option enables configuration of bi_iic_fast[] flags
2373 in u-boot bd_info structure based on u-boot environment
2374 variable "i2cfast". (see also i2cfast)
2376 CONFIG_I2C_MULTI_BUS
2378 This option allows the use of multiple I2C buses, each of which
2379 must have a controller. At any point in time, only one bus is
2380 active. To switch to a different bus, use the 'i2c dev' command.
2381 Note that bus numbering is zero-based.
2383 CONFIG_SYS_I2C_NOPROBES
2385 This option specifies a list of I2C devices that will be skipped
2386 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2387 is set, specify a list of bus-device pairs. Otherwise, specify
2388 a 1D array of device addresses
2391 #undef CONFIG_I2C_MULTI_BUS
2392 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2394 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2396 #define CONFIG_I2C_MULTI_BUS
2397 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2399 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2401 CONFIG_SYS_SPD_BUS_NUM
2403 If defined, then this indicates the I2C bus number for DDR SPD.
2404 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2406 CONFIG_SYS_RTC_BUS_NUM
2408 If defined, then this indicates the I2C bus number for the RTC.
2409 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2411 CONFIG_SYS_DTT_BUS_NUM
2413 If defined, then this indicates the I2C bus number for the DTT.
2414 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2416 CONFIG_SYS_I2C_DTT_ADDR:
2418 If defined, specifies the I2C address of the DTT device.
2419 If not defined, then U-Boot uses predefined value for
2420 specified DTT device.
2422 CONFIG_SOFT_I2C_READ_REPEATED_START
2424 defining this will force the i2c_read() function in
2425 the soft_i2c driver to perform an I2C repeated start
2426 between writing the address pointer and reading the
2427 data. If this define is omitted the default behaviour
2428 of doing a stop-start sequence will be used. Most I2C
2429 devices can use either method, but some require one or
2432 - SPI Support: CONFIG_SPI
2434 Enables SPI driver (so far only tested with
2435 SPI EEPROM, also an instance works with Crystal A/D and
2436 D/As on the SACSng board)
2440 Enables the driver for SPI controller on SuperH. Currently
2441 only SH7757 is supported.
2445 Enables extended (16-bit) SPI EEPROM addressing.
2446 (symmetrical to CONFIG_I2C_X)
2450 Enables a software (bit-bang) SPI driver rather than
2451 using hardware support. This is a general purpose
2452 driver that only requires three general I/O port pins
2453 (two outputs, one input) to function. If this is
2454 defined, the board configuration must define several
2455 SPI configuration items (port pins to use, etc). For
2456 an example, see include/configs/sacsng.h.
2460 Enables a hardware SPI driver for general-purpose reads
2461 and writes. As with CONFIG_SOFT_SPI, the board configuration
2462 must define a list of chip-select function pointers.
2463 Currently supported on some MPC8xxx processors. For an
2464 example, see include/configs/mpc8349emds.h.
2468 Enables the driver for the SPI controllers on i.MX and MXC
2469 SoCs. Currently i.MX31/35/51 are supported.
2471 - FPGA Support: CONFIG_FPGA
2473 Enables FPGA subsystem.
2475 CONFIG_FPGA_<vendor>
2477 Enables support for specific chip vendors.
2480 CONFIG_FPGA_<family>
2482 Enables support for FPGA family.
2483 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2487 Specify the number of FPGA devices to support.
2489 CONFIG_SYS_FPGA_PROG_FEEDBACK
2491 Enable printing of hash marks during FPGA configuration.
2493 CONFIG_SYS_FPGA_CHECK_BUSY
2495 Enable checks on FPGA configuration interface busy
2496 status by the configuration function. This option
2497 will require a board or device specific function to
2502 If defined, a function that provides delays in the FPGA
2503 configuration driver.
2505 CONFIG_SYS_FPGA_CHECK_CTRLC
2506 Allow Control-C to interrupt FPGA configuration
2508 CONFIG_SYS_FPGA_CHECK_ERROR
2510 Check for configuration errors during FPGA bitfile
2511 loading. For example, abort during Virtex II
2512 configuration if the INIT_B line goes low (which
2513 indicated a CRC error).
2515 CONFIG_SYS_FPGA_WAIT_INIT
2517 Maximum time to wait for the INIT_B line to deassert
2518 after PROB_B has been deasserted during a Virtex II
2519 FPGA configuration sequence. The default time is 500
2522 CONFIG_SYS_FPGA_WAIT_BUSY
2524 Maximum time to wait for BUSY to deassert during
2525 Virtex II FPGA configuration. The default is 5 ms.
2527 CONFIG_SYS_FPGA_WAIT_CONFIG
2529 Time to wait after FPGA configuration. The default is
2532 - Configuration Management:
2535 If defined, this string will be added to the U-Boot
2536 version information (U_BOOT_VERSION)
2538 - Vendor Parameter Protection:
2540 U-Boot considers the values of the environment
2541 variables "serial#" (Board Serial Number) and
2542 "ethaddr" (Ethernet Address) to be parameters that
2543 are set once by the board vendor / manufacturer, and
2544 protects these variables from casual modification by
2545 the user. Once set, these variables are read-only,
2546 and write or delete attempts are rejected. You can
2547 change this behaviour:
2549 If CONFIG_ENV_OVERWRITE is #defined in your config
2550 file, the write protection for vendor parameters is
2551 completely disabled. Anybody can change or delete
2554 Alternatively, if you #define _both_ CONFIG_ETHADDR
2555 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2556 Ethernet address is installed in the environment,
2557 which can be changed exactly ONCE by the user. [The
2558 serial# is unaffected by this, i. e. it remains
2561 The same can be accomplished in a more flexible way
2562 for any variable by configuring the type of access
2563 to allow for those variables in the ".flags" variable
2564 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2569 Define this variable to enable the reservation of
2570 "protected RAM", i. e. RAM which is not overwritten
2571 by U-Boot. Define CONFIG_PRAM to hold the number of
2572 kB you want to reserve for pRAM. You can overwrite
2573 this default value by defining an environment
2574 variable "pram" to the number of kB you want to
2575 reserve. Note that the board info structure will
2576 still show the full amount of RAM. If pRAM is
2577 reserved, a new environment variable "mem" will
2578 automatically be defined to hold the amount of
2579 remaining RAM in a form that can be passed as boot
2580 argument to Linux, for instance like that:
2582 setenv bootargs ... mem=\${mem}
2585 This way you can tell Linux not to use this memory,
2586 either, which results in a memory region that will
2587 not be affected by reboots.
2589 *WARNING* If your board configuration uses automatic
2590 detection of the RAM size, you must make sure that
2591 this memory test is non-destructive. So far, the
2592 following board configurations are known to be
2595 IVMS8, IVML24, SPD8xx, TQM8xxL,
2596 HERMES, IP860, RPXlite, LWMON,
2599 - Access to physical memory region (> 4GB)
2600 Some basic support is provided for operations on memory not
2601 normally accessible to U-Boot - e.g. some architectures
2602 support access to more than 4GB of memory on 32-bit
2603 machines using physical address extension or similar.
2604 Define CONFIG_PHYSMEM to access this basic support, which
2605 currently only supports clearing the memory.
2610 Define this variable to stop the system in case of a
2611 fatal error, so that you have to reset it manually.
2612 This is probably NOT a good idea for an embedded
2613 system where you want the system to reboot
2614 automatically as fast as possible, but it may be
2615 useful during development since you can try to debug
2616 the conditions that lead to the situation.
2618 CONFIG_NET_RETRY_COUNT
2620 This variable defines the number of retries for
2621 network operations like ARP, RARP, TFTP, or BOOTP
2622 before giving up the operation. If not defined, a
2623 default value of 5 is used.
2627 Timeout waiting for an ARP reply in milliseconds.
2631 Timeout in milliseconds used in NFS protocol.
2632 If you encounter "ERROR: Cannot umount" in nfs command,
2633 try longer timeout such as
2634 #define CONFIG_NFS_TIMEOUT 10000UL
2636 - Command Interpreter:
2637 CONFIG_AUTO_COMPLETE
2639 Enable auto completion of commands using TAB.
2641 Note that this feature has NOT been implemented yet
2642 for the "hush" shell.
2645 CONFIG_SYS_HUSH_PARSER
2647 Define this variable to enable the "hush" shell (from
2648 Busybox) as command line interpreter, thus enabling
2649 powerful command line syntax like
2650 if...then...else...fi conditionals or `&&' and '||'
2651 constructs ("shell scripts").
2653 If undefined, you get the old, much simpler behaviour
2654 with a somewhat smaller memory footprint.
2657 CONFIG_SYS_PROMPT_HUSH_PS2
2659 This defines the secondary prompt string, which is
2660 printed when the command interpreter needs more input
2661 to complete a command. Usually "> ".
2665 In the current implementation, the local variables
2666 space and global environment variables space are
2667 separated. Local variables are those you define by
2668 simply typing `name=value'. To access a local
2669 variable later on, you have write `$name' or
2670 `${name}'; to execute the contents of a variable
2671 directly type `$name' at the command prompt.
2673 Global environment variables are those you use
2674 setenv/printenv to work with. To run a command stored
2675 in such a variable, you need to use the run command,
2676 and you must not use the '$' sign to access them.
2678 To store commands and special characters in a
2679 variable, please use double quotation marks
2680 surrounding the whole text of the variable, instead
2681 of the backslashes before semicolons and special
2684 - Commandline Editing and History:
2685 CONFIG_CMDLINE_EDITING
2687 Enable editing and History functions for interactive
2688 commandline input operations
2690 - Default Environment:
2691 CONFIG_EXTRA_ENV_SETTINGS
2693 Define this to contain any number of null terminated
2694 strings (variable = value pairs) that will be part of
2695 the default environment compiled into the boot image.
2697 For example, place something like this in your
2698 board's config file:
2700 #define CONFIG_EXTRA_ENV_SETTINGS \
2704 Warning: This method is based on knowledge about the
2705 internal format how the environment is stored by the
2706 U-Boot code. This is NOT an official, exported
2707 interface! Although it is unlikely that this format
2708 will change soon, there is no guarantee either.
2709 You better know what you are doing here.
2711 Note: overly (ab)use of the default environment is
2712 discouraged. Make sure to check other ways to preset
2713 the environment like the "source" command or the
2716 CONFIG_ENV_VARS_UBOOT_CONFIG
2718 Define this in order to add variables describing the
2719 U-Boot build configuration to the default environment.
2720 These will be named arch, cpu, board, vendor, and soc.
2722 Enabling this option will cause the following to be defined:
2730 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2732 Define this in order to add variables describing certain
2733 run-time determined information about the hardware to the
2734 environment. These will be named board_name, board_rev.
2736 CONFIG_DELAY_ENVIRONMENT
2738 Normally the environment is loaded when the board is
2739 intialised so that it is available to U-Boot. This inhibits
2740 that so that the environment is not available until
2741 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2742 this is instead controlled by the value of
2743 /config/load-environment.
2745 - DataFlash Support:
2746 CONFIG_HAS_DATAFLASH
2748 Defining this option enables DataFlash features and
2749 allows to read/write in Dataflash via the standard
2752 - Serial Flash support
2755 Defining this option enables SPI flash commands
2756 'sf probe/read/write/erase/update'.
2758 Usage requires an initial 'probe' to define the serial
2759 flash parameters, followed by read/write/erase/update
2762 The following defaults may be provided by the platform
2763 to handle the common case when only a single serial
2764 flash is present on the system.
2766 CONFIG_SF_DEFAULT_BUS Bus identifier
2767 CONFIG_SF_DEFAULT_CS Chip-select
2768 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2769 CONFIG_SF_DEFAULT_SPEED in Hz
2773 Define this option to include a destructive SPI flash
2776 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2778 Define this option to use the Bank addr/Extended addr
2779 support on SPI flashes which has size > 16Mbytes.
2781 CONFIG_SF_DUAL_FLASH Dual flash memories
2783 Define this option to use dual flash support where two flash
2784 memories can be connected with a given cs line.
2785 currently Xilinx Zynq qspi support these type of connections.
2787 - SystemACE Support:
2790 Adding this option adds support for Xilinx SystemACE
2791 chips attached via some sort of local bus. The address
2792 of the chip must also be defined in the
2793 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2795 #define CONFIG_SYSTEMACE
2796 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2798 When SystemACE support is added, the "ace" device type
2799 becomes available to the fat commands, i.e. fatls.
2801 - TFTP Fixed UDP Port:
2804 If this is defined, the environment variable tftpsrcp
2805 is used to supply the TFTP UDP source port value.
2806 If tftpsrcp isn't defined, the normal pseudo-random port
2807 number generator is used.
2809 Also, the environment variable tftpdstp is used to supply
2810 the TFTP UDP destination port value. If tftpdstp isn't
2811 defined, the normal port 69 is used.
2813 The purpose for tftpsrcp is to allow a TFTP server to
2814 blindly start the TFTP transfer using the pre-configured
2815 target IP address and UDP port. This has the effect of
2816 "punching through" the (Windows XP) firewall, allowing
2817 the remainder of the TFTP transfer to proceed normally.
2818 A better solution is to properly configure the firewall,
2819 but sometimes that is not allowed.
2824 This enables a generic 'hash' command which can produce
2825 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2829 Enable the hash verify command (hash -v). This adds to code
2832 CONFIG_SHA1 - support SHA1 hashing
2833 CONFIG_SHA256 - support SHA256 hashing
2835 Note: There is also a sha1sum command, which should perhaps
2836 be deprecated in favour of 'hash sha1'.
2838 - Freescale i.MX specific commands:
2839 CONFIG_CMD_HDMIDETECT
2840 This enables 'hdmidet' command which returns true if an
2841 HDMI monitor is detected. This command is i.MX 6 specific.
2844 This enables the 'bmode' (bootmode) command for forcing
2845 a boot from specific media.
2847 This is useful for forcing the ROM's usb downloader to
2848 activate upon a watchdog reset which is nice when iterating
2849 on U-Boot. Using the reset button or running bmode normal
2850 will set it back to normal. This command currently
2851 supports i.MX53 and i.MX6.
2856 This enables the RSA algorithm used for FIT image verification
2857 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2859 The signing part is build into mkimage regardless of this
2862 - bootcount support:
2863 CONFIG_BOOTCOUNT_LIMIT
2865 This enables the bootcounter support, see:
2866 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2869 enable special bootcounter support on at91sam9xe based boards.
2871 enable special bootcounter support on blackfin based boards.
2873 enable special bootcounter support on da850 based boards.
2874 CONFIG_BOOTCOUNT_RAM
2875 enable support for the bootcounter in RAM
2876 CONFIG_BOOTCOUNT_I2C
2877 enable support for the bootcounter on an i2c (like RTC) device.
2878 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2879 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2881 CONFIG_BOOTCOUNT_ALEN = address len
2883 - Show boot progress:
2884 CONFIG_SHOW_BOOT_PROGRESS
2886 Defining this option allows to add some board-
2887 specific code (calling a user-provided function
2888 "show_boot_progress(int)") that enables you to show
2889 the system's boot progress on some display (for
2890 example, some LED's) on your board. At the moment,
2891 the following checkpoints are implemented:
2893 - Detailed boot stage timing
2895 Define this option to get detailed timing of each stage
2896 of the boot process.
2898 CONFIG_BOOTSTAGE_USER_COUNT
2899 This is the number of available user bootstage records.
2900 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2901 a new ID will be allocated from this stash. If you exceed
2902 the limit, recording will stop.
2904 CONFIG_BOOTSTAGE_REPORT
2905 Define this to print a report before boot, similar to this:
2907 Timer summary in microseconds:
2910 3,575,678 3,575,678 board_init_f start
2911 3,575,695 17 arch_cpu_init A9
2912 3,575,777 82 arch_cpu_init done
2913 3,659,598 83,821 board_init_r start
2914 3,910,375 250,777 main_loop
2915 29,916,167 26,005,792 bootm_start
2916 30,361,327 445,160 start_kernel
2918 CONFIG_CMD_BOOTSTAGE
2919 Add a 'bootstage' command which supports printing a report
2920 and un/stashing of bootstage data.
2922 CONFIG_BOOTSTAGE_FDT
2923 Stash the bootstage information in the FDT. A root 'bootstage'
2924 node is created with each bootstage id as a child. Each child
2925 has a 'name' property and either 'mark' containing the
2926 mark time in microsecond, or 'accum' containing the
2927 accumulated time for that bootstage id in microseconds.
2932 name = "board_init_f";
2941 Code in the Linux kernel can find this in /proc/devicetree.
2943 Legacy uImage format:
2946 1 common/cmd_bootm.c before attempting to boot an image
2947 -1 common/cmd_bootm.c Image header has bad magic number
2948 2 common/cmd_bootm.c Image header has correct magic number
2949 -2 common/cmd_bootm.c Image header has bad checksum
2950 3 common/cmd_bootm.c Image header has correct checksum
2951 -3 common/cmd_bootm.c Image data has bad checksum
2952 4 common/cmd_bootm.c Image data has correct checksum
2953 -4 common/cmd_bootm.c Image is for unsupported architecture
2954 5 common/cmd_bootm.c Architecture check OK
2955 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2956 6 common/cmd_bootm.c Image Type check OK
2957 -6 common/cmd_bootm.c gunzip uncompression error
2958 -7 common/cmd_bootm.c Unimplemented compression type
2959 7 common/cmd_bootm.c Uncompression OK
2960 8 common/cmd_bootm.c No uncompress/copy overwrite error
2961 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2963 9 common/image.c Start initial ramdisk verification
2964 -10 common/image.c Ramdisk header has bad magic number
2965 -11 common/image.c Ramdisk header has bad checksum
2966 10 common/image.c Ramdisk header is OK
2967 -12 common/image.c Ramdisk data has bad checksum
2968 11 common/image.c Ramdisk data has correct checksum
2969 12 common/image.c Ramdisk verification complete, start loading
2970 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2971 13 common/image.c Start multifile image verification
2972 14 common/image.c No initial ramdisk, no multifile, continue.
2974 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2976 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2977 -31 post/post.c POST test failed, detected by post_output_backlog()
2978 -32 post/post.c POST test failed, detected by post_run_single()
2980 34 common/cmd_doc.c before loading a Image from a DOC device
2981 -35 common/cmd_doc.c Bad usage of "doc" command
2982 35 common/cmd_doc.c correct usage of "doc" command
2983 -36 common/cmd_doc.c No boot device
2984 36 common/cmd_doc.c correct boot device
2985 -37 common/cmd_doc.c Unknown Chip ID on boot device
2986 37 common/cmd_doc.c correct chip ID found, device available
2987 -38 common/cmd_doc.c Read Error on boot device
2988 38 common/cmd_doc.c reading Image header from DOC device OK
2989 -39 common/cmd_doc.c Image header has bad magic number
2990 39 common/cmd_doc.c Image header has correct magic number
2991 -40 common/cmd_doc.c Error reading Image from DOC device
2992 40 common/cmd_doc.c Image header has correct magic number
2993 41 common/cmd_ide.c before loading a Image from a IDE device
2994 -42 common/cmd_ide.c Bad usage of "ide" command
2995 42 common/cmd_ide.c correct usage of "ide" command
2996 -43 common/cmd_ide.c No boot device
2997 43 common/cmd_ide.c boot device found
2998 -44 common/cmd_ide.c Device not available
2999 44 common/cmd_ide.c Device available
3000 -45 common/cmd_ide.c wrong partition selected
3001 45 common/cmd_ide.c partition selected
3002 -46 common/cmd_ide.c Unknown partition table
3003 46 common/cmd_ide.c valid partition table found
3004 -47 common/cmd_ide.c Invalid partition type
3005 47 common/cmd_ide.c correct partition type
3006 -48 common/cmd_ide.c Error reading Image Header on boot device
3007 48 common/cmd_ide.c reading Image Header from IDE device OK
3008 -49 common/cmd_ide.c Image header has bad magic number
3009 49 common/cmd_ide.c Image header has correct magic number
3010 -50 common/cmd_ide.c Image header has bad checksum
3011 50 common/cmd_ide.c Image header has correct checksum
3012 -51 common/cmd_ide.c Error reading Image from IDE device
3013 51 common/cmd_ide.c reading Image from IDE device OK
3014 52 common/cmd_nand.c before loading a Image from a NAND device
3015 -53 common/cmd_nand.c Bad usage of "nand" command
3016 53 common/cmd_nand.c correct usage of "nand" command
3017 -54 common/cmd_nand.c No boot device
3018 54 common/cmd_nand.c boot device found
3019 -55 common/cmd_nand.c Unknown Chip ID on boot device
3020 55 common/cmd_nand.c correct chip ID found, device available
3021 -56 common/cmd_nand.c Error reading Image Header on boot device
3022 56 common/cmd_nand.c reading Image Header from NAND device OK
3023 -57 common/cmd_nand.c Image header has bad magic number
3024 57 common/cmd_nand.c Image header has correct magic number
3025 -58 common/cmd_nand.c Error reading Image from NAND device
3026 58 common/cmd_nand.c reading Image from NAND device OK
3028 -60 common/env_common.c Environment has a bad CRC, using default
3030 64 net/eth.c starting with Ethernet configuration.
3031 -64 net/eth.c no Ethernet found.
3032 65 net/eth.c Ethernet found.
3034 -80 common/cmd_net.c usage wrong
3035 80 common/cmd_net.c before calling NetLoop()
3036 -81 common/cmd_net.c some error in NetLoop() occurred
3037 81 common/cmd_net.c NetLoop() back without error
3038 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3039 82 common/cmd_net.c trying automatic boot
3040 83 common/cmd_net.c running "source" command
3041 -83 common/cmd_net.c some error in automatic boot or "source" command
3042 84 common/cmd_net.c end without errors
3047 100 common/cmd_bootm.c Kernel FIT Image has correct format
3048 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3049 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3050 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3051 102 common/cmd_bootm.c Kernel unit name specified
3052 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3053 103 common/cmd_bootm.c Found configuration node
3054 104 common/cmd_bootm.c Got kernel subimage node offset
3055 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3056 105 common/cmd_bootm.c Kernel subimage hash verification OK
3057 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3058 106 common/cmd_bootm.c Architecture check OK
3059 -106 common/cmd_bootm.c Kernel subimage has wrong type
3060 107 common/cmd_bootm.c Kernel subimage type OK
3061 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3062 108 common/cmd_bootm.c Got kernel subimage data/size
3063 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3064 -109 common/cmd_bootm.c Can't get kernel subimage type
3065 -110 common/cmd_bootm.c Can't get kernel subimage comp
3066 -111 common/cmd_bootm.c Can't get kernel subimage os
3067 -112 common/cmd_bootm.c Can't get kernel subimage load address
3068 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3070 120 common/image.c Start initial ramdisk verification
3071 -120 common/image.c Ramdisk FIT image has incorrect format
3072 121 common/image.c Ramdisk FIT image has correct format
3073 122 common/image.c No ramdisk subimage unit name, using configuration
3074 -122 common/image.c Can't get configuration for ramdisk subimage
3075 123 common/image.c Ramdisk unit name specified
3076 -124 common/image.c Can't get ramdisk subimage node offset
3077 125 common/image.c Got ramdisk subimage node offset
3078 -125 common/image.c Ramdisk subimage hash verification failed
3079 126 common/image.c Ramdisk subimage hash verification OK
3080 -126 common/image.c Ramdisk subimage for unsupported architecture
3081 127 common/image.c Architecture check OK
3082 -127 common/image.c Can't get ramdisk subimage data/size
3083 128 common/image.c Got ramdisk subimage data/size
3084 129 common/image.c Can't get ramdisk load address
3085 -129 common/image.c Got ramdisk load address
3087 -130 common/cmd_doc.c Incorrect FIT image format
3088 131 common/cmd_doc.c FIT image format OK
3090 -140 common/cmd_ide.c Incorrect FIT image format
3091 141 common/cmd_ide.c FIT image format OK
3093 -150 common/cmd_nand.c Incorrect FIT image format
3094 151 common/cmd_nand.c FIT image format OK
3096 - FIT image support:
3098 Enable support for the FIT uImage format.
3100 CONFIG_FIT_BEST_MATCH
3101 When no configuration is explicitly selected, default to the
3102 one whose fdt's compatibility field best matches that of
3103 U-Boot itself. A match is considered "best" if it matches the
3104 most specific compatibility entry of U-Boot's fdt's root node.
3105 The order of entries in the configuration's fdt is ignored.
3107 CONFIG_FIT_SIGNATURE
3108 This option enables signature verification of FIT uImages,
3109 using a hash signed and verified using RSA. See
3110 doc/uImage.FIT/signature.txt for more details.
3112 - Standalone program support:
3113 CONFIG_STANDALONE_LOAD_ADDR
3115 This option defines a board specific value for the
3116 address where standalone program gets loaded, thus
3117 overwriting the architecture dependent default
3120 - Frame Buffer Address:
3123 Define CONFIG_FB_ADDR if you want to use specific
3124 address for frame buffer. This is typically the case
3125 when using a graphics controller has separate video
3126 memory. U-Boot will then place the frame buffer at
3127 the given address instead of dynamically reserving it
3128 in system RAM by calling lcd_setmem(), which grabs
3129 the memory for the frame buffer depending on the
3130 configured panel size.
3132 Please see board_init_f function.
3134 - Automatic software updates via TFTP server
3136 CONFIG_UPDATE_TFTP_CNT_MAX
3137 CONFIG_UPDATE_TFTP_MSEC_MAX
3139 These options enable and control the auto-update feature;
3140 for a more detailed description refer to doc/README.update.
3142 - MTD Support (mtdparts command, UBI support)
3145 Adds the MTD device infrastructure from the Linux kernel.
3146 Needed for mtdparts command support.
3148 CONFIG_MTD_PARTITIONS
3150 Adds the MTD partitioning infrastructure from the Linux
3151 kernel. Needed for UBI support.
3156 Adds commands for interacting with MTD partitions formatted
3157 with the UBI flash translation layer
3159 Requires also defining CONFIG_RBTREE
3161 CONFIG_UBI_SILENCE_MSG
3163 Make the verbose messages from UBI stop printing. This leaves
3164 warnings and errors enabled.
3169 Adds commands for interacting with UBI volumes formatted as
3170 UBIFS. UBIFS is read-only in u-boot.
3172 Requires UBI support as well as CONFIG_LZO
3174 CONFIG_UBIFS_SILENCE_MSG
3176 Make the verbose messages from UBIFS stop printing. This leaves
3177 warnings and errors enabled.
3181 Enable building of SPL globally.
3184 LDSCRIPT for linking the SPL binary.
3186 CONFIG_SPL_MAX_FOOTPRINT
3187 Maximum size in memory allocated to the SPL, BSS included.
3188 When defined, the linker checks that the actual memory
3189 used by SPL from _start to __bss_end does not exceed it.
3190 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3191 must not be both defined at the same time.
3194 Maximum size of the SPL image (text, data, rodata, and
3195 linker lists sections), BSS excluded.
3196 When defined, the linker checks that the actual size does
3199 CONFIG_SPL_TEXT_BASE
3200 TEXT_BASE for linking the SPL binary.
3202 CONFIG_SPL_RELOC_TEXT_BASE
3203 Address to relocate to. If unspecified, this is equal to
3204 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3206 CONFIG_SPL_BSS_START_ADDR
3207 Link address for the BSS within the SPL binary.
3209 CONFIG_SPL_BSS_MAX_SIZE
3210 Maximum size in memory allocated to the SPL BSS.
3211 When defined, the linker checks that the actual memory used
3212 by SPL from __bss_start to __bss_end does not exceed it.
3213 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3214 must not be both defined at the same time.
3217 Adress of the start of the stack SPL will use
3219 CONFIG_SPL_RELOC_STACK
3220 Adress of the start of the stack SPL will use after
3221 relocation. If unspecified, this is equal to
3224 CONFIG_SYS_SPL_MALLOC_START
3225 Starting address of the malloc pool used in SPL.
3227 CONFIG_SYS_SPL_MALLOC_SIZE
3228 The size of the malloc pool used in SPL.
3230 CONFIG_SPL_FRAMEWORK
3231 Enable the SPL framework under common/. This framework
3232 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3233 NAND loading of the Linux Kernel.
3235 CONFIG_SPL_DISPLAY_PRINT
3236 For ARM, enable an optional function to print more information
3237 about the running system.
3239 CONFIG_SPL_INIT_MINIMAL
3240 Arch init code should be built for a very small image
3242 CONFIG_SPL_LIBCOMMON_SUPPORT
3243 Support for common/libcommon.o in SPL binary
3245 CONFIG_SPL_LIBDISK_SUPPORT
3246 Support for disk/libdisk.o in SPL binary
3248 CONFIG_SPL_I2C_SUPPORT
3249 Support for drivers/i2c/libi2c.o in SPL binary
3251 CONFIG_SPL_GPIO_SUPPORT
3252 Support for drivers/gpio/libgpio.o in SPL binary
3254 CONFIG_SPL_MMC_SUPPORT
3255 Support for drivers/mmc/libmmc.o in SPL binary
3257 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3258 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3259 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3260 Address, size and partition on the MMC to load U-Boot from
3261 when the MMC is being used in raw mode.
3263 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3264 Sector to load kernel uImage from when MMC is being
3265 used in raw mode (for Falcon mode)
3267 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3268 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3269 Sector and number of sectors to load kernel argument
3270 parameters from when MMC is being used in raw mode
3273 CONFIG_SPL_FAT_SUPPORT
3274 Support for fs/fat/libfat.o in SPL binary
3276 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3277 Filename to read to load U-Boot when reading from FAT
3279 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3280 Filename to read to load kernel uImage when reading
3281 from FAT (for Falcon mode)
3283 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3284 Filename to read to load kernel argument parameters
3285 when reading from FAT (for Falcon mode)
3287 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3288 Set this for NAND SPL on PPC mpc83xx targets, so that
3289 start.S waits for the rest of the SPL to load before
3290 continuing (the hardware starts execution after just
3291 loading the first page rather than the full 4K).
3293 CONFIG_SPL_NAND_BASE
3294 Include nand_base.c in the SPL. Requires
3295 CONFIG_SPL_NAND_DRIVERS.
3297 CONFIG_SPL_NAND_DRIVERS
3298 SPL uses normal NAND drivers, not minimal drivers.
3301 Include standard software ECC in the SPL
3303 CONFIG_SPL_NAND_SIMPLE
3304 Support for NAND boot using simple NAND drivers that
3305 expose the cmd_ctrl() interface.
3307 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3308 Set for the SPL on PPC mpc8xxx targets, support for
3309 drivers/ddr/fsl/libddr.o in SPL binary.
3311 CONFIG_SPL_COMMON_INIT_DDR
3312 Set for common ddr init with serial presence detect in
3315 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3316 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3317 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3318 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3319 CONFIG_SYS_NAND_ECCBYTES
3320 Defines the size and behavior of the NAND that SPL uses
3323 CONFIG_SPL_NAND_BOOT
3324 Add support NAND boot
3326 CONFIG_SYS_NAND_U_BOOT_OFFS
3327 Location in NAND to read U-Boot from
3329 CONFIG_SYS_NAND_U_BOOT_DST
3330 Location in memory to load U-Boot to
3332 CONFIG_SYS_NAND_U_BOOT_SIZE
3333 Size of image to load
3335 CONFIG_SYS_NAND_U_BOOT_START
3336 Entry point in loaded image to jump to
3338 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3339 Define this if you need to first read the OOB and then the
3340 data. This is used for example on davinci plattforms.
3342 CONFIG_SPL_OMAP3_ID_NAND
3343 Support for an OMAP3-specific set of functions to return the
3344 ID and MFR of the first attached NAND chip, if present.
3346 CONFIG_SPL_SERIAL_SUPPORT
3347 Support for drivers/serial/libserial.o in SPL binary
3349 CONFIG_SPL_SPI_FLASH_SUPPORT
3350 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3352 CONFIG_SPL_SPI_SUPPORT
3353 Support for drivers/spi/libspi.o in SPL binary
3355 CONFIG_SPL_RAM_DEVICE
3356 Support for running image already present in ram, in SPL binary
3358 CONFIG_SPL_LIBGENERIC_SUPPORT
3359 Support for lib/libgeneric.o in SPL binary
3361 CONFIG_SPL_ENV_SUPPORT
3362 Support for the environment operating in SPL binary
3364 CONFIG_SPL_NET_SUPPORT
3365 Support for the net/libnet.o in SPL binary.
3366 It conflicts with SPL env from storage medium specified by
3367 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3370 Image offset to which the SPL should be padded before appending
3371 the SPL payload. By default, this is defined as
3372 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3373 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3374 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3377 Final target image containing SPL and payload. Some SPLs
3378 use an arch-specific makefile fragment instead, for
3379 example if more than one image needs to be produced.
3381 CONFIG_FIT_SPL_PRINT
3382 Printing information about a FIT image adds quite a bit of
3383 code to SPL. So this is normally disabled in SPL. Use this
3384 option to re-enable it. This will affect the output of the
3385 bootm command when booting a FIT image.
3389 Enable building of TPL globally.
3392 Image offset to which the TPL should be padded before appending
3393 the TPL payload. By default, this is defined as
3394 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3395 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3396 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3401 [so far only for SMDK2400 boards]
3403 - Modem support enable:
3404 CONFIG_MODEM_SUPPORT
3406 - RTS/CTS Flow control enable:
3409 - Modem debug support:
3410 CONFIG_MODEM_SUPPORT_DEBUG
3412 Enables debugging stuff (char screen[1024], dbg())
3413 for modem support. Useful only with BDI2000.
3415 - Interrupt support (PPC):
3417 There are common interrupt_init() and timer_interrupt()
3418 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3419 for CPU specific initialization. interrupt_init_cpu()
3420 should set decrementer_count to appropriate value. If
3421 CPU resets decrementer automatically after interrupt
3422 (ppc4xx) it should set decrementer_count to zero.
3423 timer_interrupt() calls timer_interrupt_cpu() for CPU
3424 specific handling. If board has watchdog / status_led
3425 / other_activity_monitor it works automatically from
3426 general timer_interrupt().
3430 In the target system modem support is enabled when a
3431 specific key (key combination) is pressed during
3432 power-on. Otherwise U-Boot will boot normally
3433 (autoboot). The key_pressed() function is called from
3434 board_init(). Currently key_pressed() is a dummy
3435 function, returning 1 and thus enabling modem
3438 If there are no modem init strings in the
3439 environment, U-Boot proceed to autoboot; the
3440 previous output (banner, info printfs) will be
3443 See also: doc/README.Modem
3445 Board initialization settings:
3446 ------------------------------
3448 During Initialization u-boot calls a number of board specific functions
3449 to allow the preparation of board specific prerequisites, e.g. pin setup
3450 before drivers are initialized. To enable these callbacks the
3451 following configuration macros have to be defined. Currently this is
3452 architecture specific, so please check arch/your_architecture/lib/board.c
3453 typically in board_init_f() and board_init_r().
3455 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3456 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3457 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3458 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3460 Configuration Settings:
3461 -----------------------
3463 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3464 undefine this when you're short of memory.
3466 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3467 width of the commands listed in the 'help' command output.
3469 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3470 prompt for user input.
3472 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3474 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3476 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3478 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3479 the application (usually a Linux kernel) when it is
3482 - CONFIG_SYS_BAUDRATE_TABLE:
3483 List of legal baudrate settings for this board.
3485 - CONFIG_SYS_CONSOLE_INFO_QUIET
3486 Suppress display of console information at boot.
3488 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3489 If the board specific function
3490 extern int overwrite_console (void);
3491 returns 1, the stdin, stderr and stdout are switched to the
3492 serial port, else the settings in the environment are used.
3494 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3495 Enable the call to overwrite_console().
3497 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3498 Enable overwrite of previous console environment settings.
3500 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3501 Begin and End addresses of the area used by the
3504 - CONFIG_SYS_ALT_MEMTEST:
3505 Enable an alternate, more extensive memory test.
3507 - CONFIG_SYS_MEMTEST_SCRATCH:
3508 Scratch address used by the alternate memory test
3509 You only need to set this if address zero isn't writeable
3511 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3512 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3513 this specified memory area will get subtracted from the top
3514 (end) of RAM and won't get "touched" at all by U-Boot. By
3515 fixing up gd->ram_size the Linux kernel should gets passed
3516 the now "corrected" memory size and won't touch it either.
3517 This should work for arch/ppc and arch/powerpc. Only Linux
3518 board ports in arch/powerpc with bootwrapper support that
3519 recalculate the memory size from the SDRAM controller setup
3520 will have to get fixed in Linux additionally.
3522 This option can be used as a workaround for the 440EPx/GRx
3523 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3526 WARNING: Please make sure that this value is a multiple of
3527 the Linux page size (normally 4k). If this is not the case,
3528 then the end address of the Linux memory will be located at a
3529 non page size aligned address and this could cause major
3532 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3533 Enable temporary baudrate change while serial download
3535 - CONFIG_SYS_SDRAM_BASE:
3536 Physical start address of SDRAM. _Must_ be 0 here.
3538 - CONFIG_SYS_MBIO_BASE:
3539 Physical start address of Motherboard I/O (if using a
3542 - CONFIG_SYS_FLASH_BASE:
3543 Physical start address of Flash memory.
3545 - CONFIG_SYS_MONITOR_BASE:
3546 Physical start address of boot monitor code (set by
3547 make config files to be same as the text base address
3548 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3549 CONFIG_SYS_FLASH_BASE when booting from flash.
3551 - CONFIG_SYS_MONITOR_LEN:
3552 Size of memory reserved for monitor code, used to
3553 determine _at_compile_time_ (!) if the environment is
3554 embedded within the U-Boot image, or in a separate
3557 - CONFIG_SYS_MALLOC_LEN:
3558 Size of DRAM reserved for malloc() use.
3560 - CONFIG_SYS_BOOTM_LEN:
3561 Normally compressed uImages are limited to an
3562 uncompressed size of 8 MBytes. If this is not enough,
3563 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3564 to adjust this setting to your needs.
3566 - CONFIG_SYS_BOOTMAPSZ:
3567 Maximum size of memory mapped by the startup code of
3568 the Linux kernel; all data that must be processed by
3569 the Linux kernel (bd_info, boot arguments, FDT blob if
3570 used) must be put below this limit, unless "bootm_low"
3571 environment variable is defined and non-zero. In such case
3572 all data for the Linux kernel must be between "bootm_low"
3573 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3574 variable "bootm_mapsize" will override the value of
3575 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3576 then the value in "bootm_size" will be used instead.
3578 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3579 Enable initrd_high functionality. If defined then the
3580 initrd_high feature is enabled and the bootm ramdisk subcommand
3583 - CONFIG_SYS_BOOT_GET_CMDLINE:
3584 Enables allocating and saving kernel cmdline in space between
3585 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3587 - CONFIG_SYS_BOOT_GET_KBD:
3588 Enables allocating and saving a kernel copy of the bd_info in
3589 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3591 - CONFIG_SYS_MAX_FLASH_BANKS:
3592 Max number of Flash memory banks
3594 - CONFIG_SYS_MAX_FLASH_SECT:
3595 Max number of sectors on a Flash chip
3597 - CONFIG_SYS_FLASH_ERASE_TOUT:
3598 Timeout for Flash erase operations (in ms)
3600 - CONFIG_SYS_FLASH_WRITE_TOUT:
3601 Timeout for Flash write operations (in ms)
3603 - CONFIG_SYS_FLASH_LOCK_TOUT
3604 Timeout for Flash set sector lock bit operation (in ms)
3606 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3607 Timeout for Flash clear lock bits operation (in ms)
3609 - CONFIG_SYS_FLASH_PROTECTION
3610 If defined, hardware flash sectors protection is used
3611 instead of U-Boot software protection.
3613 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3615 Enable TFTP transfers directly to flash memory;
3616 without this option such a download has to be
3617 performed in two steps: (1) download to RAM, and (2)
3618 copy from RAM to flash.
3620 The two-step approach is usually more reliable, since
3621 you can check if the download worked before you erase
3622 the flash, but in some situations (when system RAM is
3623 too limited to allow for a temporary copy of the
3624 downloaded image) this option may be very useful.
3626 - CONFIG_SYS_FLASH_CFI:
3627 Define if the flash driver uses extra elements in the
3628 common flash structure for storing flash geometry.
3630 - CONFIG_FLASH_CFI_DRIVER
3631 This option also enables the building of the cfi_flash driver
3632 in the drivers directory
3634 - CONFIG_FLASH_CFI_MTD
3635 This option enables the building of the cfi_mtd driver
3636 in the drivers directory. The driver exports CFI flash
3639 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3640 Use buffered writes to flash.
3642 - CONFIG_FLASH_SPANSION_S29WS_N
3643 s29ws-n MirrorBit flash has non-standard addresses for buffered
3646 - CONFIG_SYS_FLASH_QUIET_TEST
3647 If this option is defined, the common CFI flash doesn't
3648 print it's warning upon not recognized FLASH banks. This
3649 is useful, if some of the configured banks are only
3650 optionally available.
3652 - CONFIG_FLASH_SHOW_PROGRESS
3653 If defined (must be an integer), print out countdown
3654 digits and dots. Recommended value: 45 (9..1) for 80
3655 column displays, 15 (3..1) for 40 column displays.
3657 - CONFIG_FLASH_VERIFY
3658 If defined, the content of the flash (destination) is compared
3659 against the source after the write operation. An error message
3660 will be printed when the contents are not identical.
3661 Please note that this option is useless in nearly all cases,
3662 since such flash programming errors usually are detected earlier
3663 while unprotecting/erasing/programming. Please only enable
3664 this option if you really know what you are doing.
3666 - CONFIG_SYS_RX_ETH_BUFFER:
3667 Defines the number of Ethernet receive buffers. On some
3668 Ethernet controllers it is recommended to set this value
3669 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3670 buffers can be full shortly after enabling the interface
3671 on high Ethernet traffic.
3672 Defaults to 4 if not defined.
3674 - CONFIG_ENV_MAX_ENTRIES
3676 Maximum number of entries in the hash table that is used
3677 internally to store the environment settings. The default
3678 setting is supposed to be generous and should work in most
3679 cases. This setting can be used to tune behaviour; see
3680 lib/hashtable.c for details.
3682 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3683 - CONFIG_ENV_FLAGS_LIST_STATIC
3684 Enable validation of the values given to environment variables when
3685 calling env set. Variables can be restricted to only decimal,
3686 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3687 the variables can also be restricted to IP address or MAC address.
3689 The format of the list is:
3690 type_attribute = [s|d|x|b|i|m]
3691 access_atribute = [a|r|o|c]
3692 attributes = type_attribute[access_atribute]
3693 entry = variable_name[:attributes]
3696 The type attributes are:
3697 s - String (default)
3700 b - Boolean ([1yYtT|0nNfF])
3704 The access attributes are:
3710 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3711 Define this to a list (string) to define the ".flags"
3712 envirnoment variable in the default or embedded environment.
3714 - CONFIG_ENV_FLAGS_LIST_STATIC
3715 Define this to a list (string) to define validation that
3716 should be done if an entry is not found in the ".flags"
3717 environment variable. To override a setting in the static
3718 list, simply add an entry for the same variable name to the
3721 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3722 If defined, don't allow the -f switch to env set override variable
3725 - CONFIG_SYS_GENERIC_BOARD
3726 This selects the architecture-generic board system instead of the
3727 architecture-specific board files. It is intended to move boards
3728 to this new framework over time. Defining this will disable the
3729 arch/foo/lib/board.c file and use common/board_f.c and
3730 common/board_r.c instead. To use this option your architecture
3731 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3732 its config.mk file). If you find problems enabling this option on
3733 your board please report the problem and send patches!
3735 - CONFIG_SYS_SYM_OFFSETS
3736 This is set by architectures that use offsets for link symbols
3737 instead of absolute values. So bss_start is obtained using an
3738 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3739 directly. You should not need to touch this setting.
3741 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3742 This is set by OMAP boards for the max time that reset should
3743 be asserted. See doc/README.omap-reset-time for details on how
3744 the value can be calulated on a given board.
3746 The following definitions that deal with the placement and management
3747 of environment data (variable area); in general, we support the
3748 following configurations:
3750 - CONFIG_BUILD_ENVCRC:
3752 Builds up envcrc with the target environment so that external utils
3753 may easily extract it and embed it in final U-Boot images.
3755 - CONFIG_ENV_IS_IN_FLASH:
3757 Define this if the environment is in flash memory.
3759 a) The environment occupies one whole flash sector, which is
3760 "embedded" in the text segment with the U-Boot code. This
3761 happens usually with "bottom boot sector" or "top boot
3762 sector" type flash chips, which have several smaller
3763 sectors at the start or the end. For instance, such a
3764 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3765 such a case you would place the environment in one of the
3766 4 kB sectors - with U-Boot code before and after it. With
3767 "top boot sector" type flash chips, you would put the
3768 environment in one of the last sectors, leaving a gap
3769 between U-Boot and the environment.
3771 - CONFIG_ENV_OFFSET:
3773 Offset of environment data (variable area) to the
3774 beginning of flash memory; for instance, with bottom boot
3775 type flash chips the second sector can be used: the offset
3776 for this sector is given here.
3778 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3782 This is just another way to specify the start address of
3783 the flash sector containing the environment (instead of
3786 - CONFIG_ENV_SECT_SIZE:
3788 Size of the sector containing the environment.
3791 b) Sometimes flash chips have few, equal sized, BIG sectors.
3792 In such a case you don't want to spend a whole sector for
3797 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3798 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3799 of this flash sector for the environment. This saves
3800 memory for the RAM copy of the environment.
3802 It may also save flash memory if you decide to use this
3803 when your environment is "embedded" within U-Boot code,
3804 since then the remainder of the flash sector could be used
3805 for U-Boot code. It should be pointed out that this is
3806 STRONGLY DISCOURAGED from a robustness point of view:
3807 updating the environment in flash makes it always
3808 necessary to erase the WHOLE sector. If something goes
3809 wrong before the contents has been restored from a copy in
3810 RAM, your target system will be dead.
3812 - CONFIG_ENV_ADDR_REDUND
3813 CONFIG_ENV_SIZE_REDUND
3815 These settings describe a second storage area used to hold
3816 a redundant copy of the environment data, so that there is
3817 a valid backup copy in case there is a power failure during
3818 a "saveenv" operation.
3820 BE CAREFUL! Any changes to the flash layout, and some changes to the
3821 source code will make it necessary to adapt <board>/u-boot.lds*
3825 - CONFIG_ENV_IS_IN_NVRAM:
3827 Define this if you have some non-volatile memory device
3828 (NVRAM, battery buffered SRAM) which you want to use for the
3834 These two #defines are used to determine the memory area you
3835 want to use for environment. It is assumed that this memory
3836 can just be read and written to, without any special
3839 BE CAREFUL! The first access to the environment happens quite early
3840 in U-Boot initalization (when we try to get the setting of for the
3841 console baudrate). You *MUST* have mapped your NVRAM area then, or
3844 Please note that even with NVRAM we still use a copy of the
3845 environment in RAM: we could work on NVRAM directly, but we want to
3846 keep settings there always unmodified except somebody uses "saveenv"
3847 to save the current settings.
3850 - CONFIG_ENV_IS_IN_EEPROM:
3852 Use this if you have an EEPROM or similar serial access
3853 device and a driver for it.
3855 - CONFIG_ENV_OFFSET:
3858 These two #defines specify the offset and size of the
3859 environment area within the total memory of your EEPROM.
3861 - CONFIG_SYS_I2C_EEPROM_ADDR:
3862 If defined, specified the chip address of the EEPROM device.
3863 The default address is zero.
3865 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3866 If defined, the number of bits used to address bytes in a
3867 single page in the EEPROM device. A 64 byte page, for example
3868 would require six bits.
3870 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3871 If defined, the number of milliseconds to delay between
3872 page writes. The default is zero milliseconds.
3874 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3875 The length in bytes of the EEPROM memory array address. Note
3876 that this is NOT the chip address length!
3878 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3879 EEPROM chips that implement "address overflow" are ones
3880 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3881 address and the extra bits end up in the "chip address" bit
3882 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3885 Note that we consider the length of the address field to
3886 still be one byte because the extra address bits are hidden
3887 in the chip address.
3889 - CONFIG_SYS_EEPROM_SIZE:
3890 The size in bytes of the EEPROM device.
3892 - CONFIG_ENV_EEPROM_IS_ON_I2C
3893 define this, if you have I2C and SPI activated, and your
3894 EEPROM, which holds the environment, is on the I2C bus.
3896 - CONFIG_I2C_ENV_EEPROM_BUS
3897 if you have an Environment on an EEPROM reached over
3898 I2C muxes, you can define here, how to reach this
3899 EEPROM. For example:
3901 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3903 EEPROM which holds the environment, is reached over
3904 a pca9547 i2c mux with address 0x70, channel 3.
3906 - CONFIG_ENV_IS_IN_DATAFLASH:
3908 Define this if you have a DataFlash memory device which you
3909 want to use for the environment.
3911 - CONFIG_ENV_OFFSET:
3915 These three #defines specify the offset and size of the
3916 environment area within the total memory of your DataFlash placed
3917 at the specified address.
3919 - CONFIG_ENV_IS_IN_REMOTE:
3921 Define this if you have a remote memory space which you
3922 want to use for the local device's environment.
3927 These two #defines specify the address and size of the
3928 environment area within the remote memory space. The
3929 local device can get the environment from remote memory
3930 space by SRIO or PCIE links.
3932 BE CAREFUL! For some special cases, the local device can not use
3933 "saveenv" command. For example, the local device will get the
3934 environment stored in a remote NOR flash by SRIO or PCIE link,
3935 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3937 - CONFIG_ENV_IS_IN_NAND:
3939 Define this if you have a NAND device which you want to use
3940 for the environment.
3942 - CONFIG_ENV_OFFSET:
3945 These two #defines specify the offset and size of the environment
3946 area within the first NAND device. CONFIG_ENV_OFFSET must be
3947 aligned to an erase block boundary.
3949 - CONFIG_ENV_OFFSET_REDUND (optional):
3951 This setting describes a second storage area of CONFIG_ENV_SIZE
3952 size used to hold a redundant copy of the environment data, so
3953 that there is a valid backup copy in case there is a power failure
3954 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3955 aligned to an erase block boundary.
3957 - CONFIG_ENV_RANGE (optional):
3959 Specifies the length of the region in which the environment
3960 can be written. This should be a multiple of the NAND device's
3961 block size. Specifying a range with more erase blocks than
3962 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3963 the range to be avoided.
3965 - CONFIG_ENV_OFFSET_OOB (optional):
3967 Enables support for dynamically retrieving the offset of the
3968 environment from block zero's out-of-band data. The
3969 "nand env.oob" command can be used to record this offset.
3970 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3971 using CONFIG_ENV_OFFSET_OOB.
3973 - CONFIG_NAND_ENV_DST
3975 Defines address in RAM to which the nand_spl code should copy the
3976 environment. If redundant environment is used, it will be copied to
3977 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3979 - CONFIG_ENV_IS_IN_UBI:
3981 Define this if you have an UBI volume that you want to use for the
3982 environment. This has the benefit of wear-leveling the environment
3983 accesses, which is important on NAND.
3985 - CONFIG_ENV_UBI_PART:
3987 Define this to a string that is the mtd partition containing the UBI.
3989 - CONFIG_ENV_UBI_VOLUME:
3991 Define this to the name of the volume that you want to store the
3994 - CONFIG_ENV_UBI_VOLUME_REDUND:
3996 Define this to the name of another volume to store a second copy of
3997 the environment in. This will enable redundant environments in UBI.
3998 It is assumed that both volumes are in the same MTD partition.
4000 - CONFIG_UBI_SILENCE_MSG
4001 - CONFIG_UBIFS_SILENCE_MSG
4003 You will probably want to define these to avoid a really noisy system
4004 when storing the env in UBI.
4006 - CONFIG_ENV_IS_IN_MMC:
4008 Define this if you have an MMC device which you want to use for the
4011 - CONFIG_SYS_MMC_ENV_DEV:
4013 Specifies which MMC device the environment is stored in.
4015 - CONFIG_SYS_MMC_ENV_PART (optional):
4017 Specifies which MMC partition the environment is stored in. If not
4018 set, defaults to partition 0, the user area. Common values might be
4019 1 (first MMC boot partition), 2 (second MMC boot partition).
4021 - CONFIG_ENV_OFFSET:
4024 These two #defines specify the offset and size of the environment
4025 area within the specified MMC device.
4027 If offset is positive (the usual case), it is treated as relative to
4028 the start of the MMC partition. If offset is negative, it is treated
4029 as relative to the end of the MMC partition. This can be useful if
4030 your board may be fitted with different MMC devices, which have
4031 different sizes for the MMC partitions, and you always want the
4032 environment placed at the very end of the partition, to leave the
4033 maximum possible space before it, to store other data.
4035 These two values are in units of bytes, but must be aligned to an
4036 MMC sector boundary.
4038 - CONFIG_ENV_OFFSET_REDUND (optional):
4040 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4041 hold a redundant copy of the environment data. This provides a
4042 valid backup copy in case the other copy is corrupted, e.g. due
4043 to a power failure during a "saveenv" operation.
4045 This value may also be positive or negative; this is handled in the
4046 same way as CONFIG_ENV_OFFSET.
4048 This value is also in units of bytes, but must also be aligned to
4049 an MMC sector boundary.
4051 - CONFIG_ENV_SIZE_REDUND (optional):
4053 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4054 set. If this value is set, it must be set to the same value as
4057 - CONFIG_SYS_SPI_INIT_OFFSET
4059 Defines offset to the initial SPI buffer area in DPRAM. The
4060 area is used at an early stage (ROM part) if the environment
4061 is configured to reside in the SPI EEPROM: We need a 520 byte
4062 scratch DPRAM area. It is used between the two initialization
4063 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4064 to be a good choice since it makes it far enough from the
4065 start of the data area as well as from the stack pointer.
4067 Please note that the environment is read-only until the monitor
4068 has been relocated to RAM and a RAM copy of the environment has been
4069 created; also, when using EEPROM you will have to use getenv_f()
4070 until then to read environment variables.
4072 The environment is protected by a CRC32 checksum. Before the monitor
4073 is relocated into RAM, as a result of a bad CRC you will be working
4074 with the compiled-in default environment - *silently*!!! [This is
4075 necessary, because the first environment variable we need is the
4076 "baudrate" setting for the console - if we have a bad CRC, we don't
4077 have any device yet where we could complain.]
4079 Note: once the monitor has been relocated, then it will complain if
4080 the default environment is used; a new CRC is computed as soon as you
4081 use the "saveenv" command to store a valid environment.
4083 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4084 Echo the inverted Ethernet link state to the fault LED.
4086 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4087 also needs to be defined.
4089 - CONFIG_SYS_FAULT_MII_ADDR:
4090 MII address of the PHY to check for the Ethernet link state.
4092 - CONFIG_NS16550_MIN_FUNCTIONS:
4093 Define this if you desire to only have use of the NS16550_init
4094 and NS16550_putc functions for the serial driver located at
4095 drivers/serial/ns16550.c. This option is useful for saving
4096 space for already greatly restricted images, including but not
4097 limited to NAND_SPL configurations.
4099 - CONFIG_DISPLAY_BOARDINFO
4100 Display information about the board that U-Boot is running on
4101 when U-Boot starts up. The board function checkboard() is called
4104 - CONFIG_DISPLAY_BOARDINFO_LATE
4105 Similar to the previous option, but display this information
4106 later, once stdio is running and output goes to the LCD, if
4109 Low Level (hardware related) configuration options:
4110 ---------------------------------------------------
4112 - CONFIG_SYS_CACHELINE_SIZE:
4113 Cache Line Size of the CPU.
4115 - CONFIG_SYS_DEFAULT_IMMR:
4116 Default address of the IMMR after system reset.
4118 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4119 and RPXsuper) to be able to adjust the position of
4120 the IMMR register after a reset.
4122 - CONFIG_SYS_CCSRBAR_DEFAULT:
4123 Default (power-on reset) physical address of CCSR on Freescale
4126 - CONFIG_SYS_CCSRBAR:
4127 Virtual address of CCSR. On a 32-bit build, this is typically
4128 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4130 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4131 for cross-platform code that uses that macro instead.
4133 - CONFIG_SYS_CCSRBAR_PHYS:
4134 Physical address of CCSR. CCSR can be relocated to a new
4135 physical address, if desired. In this case, this macro should
4136 be set to that address. Otherwise, it should be set to the
4137 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4138 is typically relocated on 36-bit builds. It is recommended
4139 that this macro be defined via the _HIGH and _LOW macros:
4141 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4142 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4144 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4145 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4146 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4147 used in assembly code, so it must not contain typecasts or
4148 integer size suffixes (e.g. "ULL").
4150 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4151 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4152 used in assembly code, so it must not contain typecasts or
4153 integer size suffixes (e.g. "ULL").
4155 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4156 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4157 forced to a value that ensures that CCSR is not relocated.
4159 - Floppy Disk Support:
4160 CONFIG_SYS_FDC_DRIVE_NUMBER
4162 the default drive number (default value 0)
4164 CONFIG_SYS_ISA_IO_STRIDE
4166 defines the spacing between FDC chipset registers
4169 CONFIG_SYS_ISA_IO_OFFSET
4171 defines the offset of register from address. It
4172 depends on which part of the data bus is connected to
4173 the FDC chipset. (default value 0)
4175 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4176 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4179 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4180 fdc_hw_init() is called at the beginning of the FDC
4181 setup. fdc_hw_init() must be provided by the board
4182 source code. It is used to make hardware dependant
4186 Most IDE controllers were designed to be connected with PCI
4187 interface. Only few of them were designed for AHB interface.
4188 When software is doing ATA command and data transfer to
4189 IDE devices through IDE-AHB controller, some additional
4190 registers accessing to these kind of IDE-AHB controller
4193 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4194 DO NOT CHANGE unless you know exactly what you're
4195 doing! (11-4) [MPC8xx/82xx systems only]
4197 - CONFIG_SYS_INIT_RAM_ADDR:
4199 Start address of memory area that can be used for
4200 initial data and stack; please note that this must be
4201 writable memory that is working WITHOUT special
4202 initialization, i. e. you CANNOT use normal RAM which
4203 will become available only after programming the
4204 memory controller and running certain initialization
4207 U-Boot uses the following memory types:
4208 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4209 - MPC824X: data cache
4210 - PPC4xx: data cache
4212 - CONFIG_SYS_GBL_DATA_OFFSET:
4214 Offset of the initial data structure in the memory
4215 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4216 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4217 data is located at the end of the available space
4218 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4219 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4220 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4221 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4224 On the MPC824X (or other systems that use the data
4225 cache for initial memory) the address chosen for
4226 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4227 point to an otherwise UNUSED address space between
4228 the top of RAM and the start of the PCI space.
4230 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4232 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4234 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4236 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4238 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4240 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4242 - CONFIG_SYS_OR_TIMING_SDRAM:
4245 - CONFIG_SYS_MAMR_PTA:
4246 periodic timer for refresh
4248 - CONFIG_SYS_DER: Debug Event Register (37-47)
4250 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4251 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4252 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4253 CONFIG_SYS_BR1_PRELIM:
4254 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4256 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4257 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4258 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4259 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4261 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4262 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4263 Machine Mode Register and Memory Periodic Timer
4264 Prescaler definitions (SDRAM timing)
4266 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4267 enable I2C microcode relocation patch (MPC8xx);
4268 define relocation offset in DPRAM [DSP2]
4270 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4271 enable SMC microcode relocation patch (MPC8xx);
4272 define relocation offset in DPRAM [SMC1]
4274 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4275 enable SPI microcode relocation patch (MPC8xx);
4276 define relocation offset in DPRAM [SCC4]
4278 - CONFIG_SYS_USE_OSCCLK:
4279 Use OSCM clock mode on MBX8xx board. Be careful,
4280 wrong setting might damage your board. Read
4281 doc/README.MBX before setting this variable!
4283 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4284 Offset of the bootmode word in DPRAM used by post
4285 (Power On Self Tests). This definition overrides
4286 #define'd default value in commproc.h resp.
4289 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4290 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4291 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4292 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4293 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4294 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4295 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4296 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4297 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4299 - CONFIG_PCI_DISABLE_PCIE:
4300 Disable PCI-Express on systems where it is supported but not
4303 - CONFIG_PCI_ENUM_ONLY
4304 Only scan through and get the devices on the busses.
4305 Don't do any setup work, presumably because someone or
4306 something has already done it, and we don't need to do it
4307 a second time. Useful for platforms that are pre-booted
4308 by coreboot or similar.
4310 - CONFIG_PCI_INDIRECT_BRIDGE:
4311 Enable support for indirect PCI bridges.
4314 Chip has SRIO or not
4317 Board has SRIO 1 port available
4320 Board has SRIO 2 port available
4322 - CONFIG_SRIO_PCIE_BOOT_MASTER
4323 Board can support master function for Boot from SRIO and PCIE
4325 - CONFIG_SYS_SRIOn_MEM_VIRT:
4326 Virtual Address of SRIO port 'n' memory region
4328 - CONFIG_SYS_SRIOn_MEM_PHYS:
4329 Physical Address of SRIO port 'n' memory region
4331 - CONFIG_SYS_SRIOn_MEM_SIZE:
4332 Size of SRIO port 'n' memory region
4334 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4335 Defined to tell the NAND controller that the NAND chip is using
4337 Not all NAND drivers use this symbol.
4338 Example of drivers that use it:
4339 - drivers/mtd/nand/ndfc.c
4340 - drivers/mtd/nand/mxc_nand.c
4342 - CONFIG_SYS_NDFC_EBC0_CFG
4343 Sets the EBC0_CFG register for the NDFC. If not defined
4344 a default value will be used.
4347 Get DDR timing information from an I2C EEPROM. Common
4348 with pluggable memory modules such as SODIMMs
4351 I2C address of the SPD EEPROM
4353 - CONFIG_SYS_SPD_BUS_NUM
4354 If SPD EEPROM is on an I2C bus other than the first
4355 one, specify here. Note that the value must resolve
4356 to something your driver can deal with.
4358 - CONFIG_SYS_DDR_RAW_TIMING
4359 Get DDR timing information from other than SPD. Common with
4360 soldered DDR chips onboard without SPD. DDR raw timing
4361 parameters are extracted from datasheet and hard-coded into
4362 header files or board specific files.
4364 - CONFIG_FSL_DDR_INTERACTIVE
4365 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4367 - CONFIG_SYS_83XX_DDR_USES_CS0
4368 Only for 83xx systems. If specified, then DDR should
4369 be configured using CS0 and CS1 instead of CS2 and CS3.
4371 - CONFIG_ETHER_ON_FEC[12]
4372 Define to enable FEC[12] on a 8xx series processor.
4374 - CONFIG_FEC[12]_PHY
4375 Define to the hardcoded PHY address which corresponds
4376 to the given FEC; i. e.
4377 #define CONFIG_FEC1_PHY 4
4378 means that the PHY with address 4 is connected to FEC1
4380 When set to -1, means to probe for first available.
4382 - CONFIG_FEC[12]_PHY_NORXERR
4383 The PHY does not have a RXERR line (RMII only).
4384 (so program the FEC to ignore it).
4387 Enable RMII mode for all FECs.
4388 Note that this is a global option, we can't
4389 have one FEC in standard MII mode and another in RMII mode.
4391 - CONFIG_CRC32_VERIFY
4392 Add a verify option to the crc32 command.
4395 => crc32 -v <address> <count> <crc32>
4397 Where address/count indicate a memory area
4398 and crc32 is the correct crc32 which the
4402 Add the "loopw" memory command. This only takes effect if
4403 the memory commands are activated globally (CONFIG_CMD_MEM).
4406 Add the "mdc" and "mwc" memory commands. These are cyclic
4411 This command will print 4 bytes (10,11,12,13) each 500 ms.
4413 => mwc.l 100 12345678 10
4414 This command will write 12345678 to address 100 all 10 ms.
4416 This only takes effect if the memory commands are activated
4417 globally (CONFIG_CMD_MEM).
4419 - CONFIG_SKIP_LOWLEVEL_INIT
4420 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4421 low level initializations (like setting up the memory
4422 controller) are omitted and/or U-Boot does not
4423 relocate itself into RAM.
4425 Normally this variable MUST NOT be defined. The only
4426 exception is when U-Boot is loaded (to RAM) by some
4427 other boot loader or by a debugger which performs
4428 these initializations itself.
4431 Modifies the behaviour of start.S when compiling a loader
4432 that is executed before the actual U-Boot. E.g. when
4433 compiling a NAND SPL.
4436 Modifies the behaviour of start.S when compiling a loader
4437 that is executed after the SPL and before the actual U-Boot.
4438 It is loaded by the SPL.
4440 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4441 Only for 85xx systems. If this variable is specified, the section
4442 .resetvec is not kept and the section .bootpg is placed in the
4443 previous 4k of the .text section.
4445 - CONFIG_ARCH_MAP_SYSMEM
4446 Generally U-Boot (and in particular the md command) uses
4447 effective address. It is therefore not necessary to regard
4448 U-Boot address as virtual addresses that need to be translated
4449 to physical addresses. However, sandbox requires this, since
4450 it maintains its own little RAM buffer which contains all
4451 addressable memory. This option causes some memory accesses
4452 to be mapped through map_sysmem() / unmap_sysmem().
4454 - CONFIG_USE_ARCH_MEMCPY
4455 CONFIG_USE_ARCH_MEMSET
4456 If these options are used a optimized version of memcpy/memset will
4457 be used if available. These functions may be faster under some
4458 conditions but may increase the binary size.
4460 - CONFIG_X86_RESET_VECTOR
4461 If defined, the x86 reset vector code is included. This is not
4462 needed when U-Boot is running from Coreboot.
4465 Defines the MPU clock speed (in MHz).
4467 NOTE : currently only supported on AM335x platforms.
4469 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4470 Enables the RTC32K OSC on AM33xx based plattforms
4472 Freescale QE/FMAN Firmware Support:
4473 -----------------------------------
4475 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4476 loading of "firmware", which is encoded in the QE firmware binary format.
4477 This firmware often needs to be loaded during U-Boot booting, so macros
4478 are used to identify the storage device (NOR flash, SPI, etc) and the address
4481 - CONFIG_SYS_QE_FMAN_FW_ADDR
4482 The address in the storage device where the firmware is located. The
4483 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4486 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4487 The maximum possible size of the firmware. The firmware binary format
4488 has a field that specifies the actual size of the firmware, but it
4489 might not be possible to read any part of the firmware unless some
4490 local storage is allocated to hold the entire firmware first.
4492 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4493 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4494 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4495 virtual address in NOR flash.
4497 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4498 Specifies that QE/FMAN firmware is located in NAND flash.
4499 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4501 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4502 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4503 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4505 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4506 Specifies that QE/FMAN firmware is located on the primary SPI
4507 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4509 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4510 Specifies that QE/FMAN firmware is located in the remote (master)
4511 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4512 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4513 window->master inbound window->master LAW->the ucode address in
4514 master's memory space.
4516 Building the Software:
4517 ======================
4519 Building U-Boot has been tested in several native build environments
4520 and in many different cross environments. Of course we cannot support
4521 all possibly existing versions of cross development tools in all
4522 (potentially obsolete) versions. In case of tool chain problems we
4523 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4524 which is extensively used to build and test U-Boot.
4526 If you are not using a native environment, it is assumed that you
4527 have GNU cross compiling tools available in your path. In this case,
4528 you must set the environment variable CROSS_COMPILE in your shell.
4529 Note that no changes to the Makefile or any other source files are
4530 necessary. For example using the ELDK on a 4xx CPU, please enter:
4532 $ CROSS_COMPILE=ppc_4xx-
4533 $ export CROSS_COMPILE
4535 Note: If you wish to generate Windows versions of the utilities in
4536 the tools directory you can use the MinGW toolchain
4537 (http://www.mingw.org). Set your HOST tools to the MinGW
4538 toolchain and execute 'make tools'. For example:
4540 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4542 Binaries such as tools/mkimage.exe will be created which can
4543 be executed on computers running Windows.
4545 U-Boot is intended to be simple to build. After installing the
4546 sources you must configure U-Boot for one specific board type. This
4551 where "NAME_config" is the name of one of the existing configu-
4552 rations; see boards.cfg for supported names.
4554 Note: for some board special configuration names may exist; check if
4555 additional information is available from the board vendor; for
4556 instance, the TQM823L systems are available without (standard)
4557 or with LCD support. You can select such additional "features"
4558 when choosing the configuration, i. e.
4561 - will configure for a plain TQM823L, i. e. no LCD support
4563 make TQM823L_LCD_config
4564 - will configure for a TQM823L with U-Boot console on LCD
4569 Finally, type "make all", and you should get some working U-Boot
4570 images ready for download to / installation on your system:
4572 - "u-boot.bin" is a raw binary image
4573 - "u-boot" is an image in ELF binary format
4574 - "u-boot.srec" is in Motorola S-Record format
4576 By default the build is performed locally and the objects are saved
4577 in the source directory. One of the two methods can be used to change
4578 this behavior and build U-Boot to some external directory:
4580 1. Add O= to the make command line invocations:
4582 make O=/tmp/build distclean
4583 make O=/tmp/build NAME_config
4584 make O=/tmp/build all
4586 2. Set environment variable BUILD_DIR to point to the desired location:
4588 export BUILD_DIR=/tmp/build
4593 Note that the command line "O=" setting overrides the BUILD_DIR environment
4597 Please be aware that the Makefiles assume you are using GNU make, so
4598 for instance on NetBSD you might need to use "gmake" instead of
4602 If the system board that you have is not listed, then you will need
4603 to port U-Boot to your hardware platform. To do this, follow these
4606 1. Add a new configuration option for your board to the toplevel
4607 "boards.cfg" file, using the existing entries as examples.
4608 Follow the instructions there to keep the boards in order.
4609 2. Create a new directory to hold your board specific code. Add any
4610 files you need. In your board directory, you will need at least
4611 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4612 3. Create a new configuration file "include/configs/<board>.h" for
4614 3. If you're porting U-Boot to a new CPU, then also create a new
4615 directory to hold your CPU specific code. Add any files you need.
4616 4. Run "make <board>_config" with your new name.
4617 5. Type "make", and you should get a working "u-boot.srec" file
4618 to be installed on your target system.
4619 6. Debug and solve any problems that might arise.
4620 [Of course, this last step is much harder than it sounds.]
4623 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4624 ==============================================================
4626 If you have modified U-Boot sources (for instance added a new board
4627 or support for new devices, a new CPU, etc.) you are expected to
4628 provide feedback to the other developers. The feedback normally takes
4629 the form of a "patch", i. e. a context diff against a certain (latest
4630 official or latest in the git repository) version of U-Boot sources.
4632 But before you submit such a patch, please verify that your modifi-
4633 cation did not break existing code. At least make sure that *ALL* of
4634 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4635 just run the "MAKEALL" script, which will configure and build U-Boot
4636 for ALL supported system. Be warned, this will take a while. You can
4637 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4638 environment variable to the script, i. e. to use the ELDK cross tools
4641 CROSS_COMPILE=ppc_8xx- MAKEALL
4643 or to build on a native PowerPC system you can type
4645 CROSS_COMPILE=' ' MAKEALL
4647 When using the MAKEALL script, the default behaviour is to build
4648 U-Boot in the source directory. This location can be changed by
4649 setting the BUILD_DIR environment variable. Also, for each target
4650 built, the MAKEALL script saves two log files (<target>.ERR and
4651 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4652 location can be changed by setting the MAKEALL_LOGDIR environment
4653 variable. For example:
4655 export BUILD_DIR=/tmp/build
4656 export MAKEALL_LOGDIR=/tmp/log
4657 CROSS_COMPILE=ppc_8xx- MAKEALL
4659 With the above settings build objects are saved in the /tmp/build,
4660 log files are saved in the /tmp/log and the source tree remains clean
4661 during the whole build process.
4664 See also "U-Boot Porting Guide" below.
4667 Monitor Commands - Overview:
4668 ============================
4670 go - start application at address 'addr'
4671 run - run commands in an environment variable
4672 bootm - boot application image from memory
4673 bootp - boot image via network using BootP/TFTP protocol
4674 bootz - boot zImage from memory
4675 tftpboot- boot image via network using TFTP protocol
4676 and env variables "ipaddr" and "serverip"
4677 (and eventually "gatewayip")
4678 tftpput - upload a file via network using TFTP protocol
4679 rarpboot- boot image via network using RARP/TFTP protocol
4680 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4681 loads - load S-Record file over serial line
4682 loadb - load binary file over serial line (kermit mode)
4684 mm - memory modify (auto-incrementing)
4685 nm - memory modify (constant address)
4686 mw - memory write (fill)
4688 cmp - memory compare
4689 crc32 - checksum calculation
4690 i2c - I2C sub-system
4691 sspi - SPI utility commands
4692 base - print or set address offset
4693 printenv- print environment variables
4694 setenv - set environment variables
4695 saveenv - save environment variables to persistent storage
4696 protect - enable or disable FLASH write protection
4697 erase - erase FLASH memory
4698 flinfo - print FLASH memory information
4699 nand - NAND memory operations (see doc/README.nand)
4700 bdinfo - print Board Info structure
4701 iminfo - print header information for application image
4702 coninfo - print console devices and informations
4703 ide - IDE sub-system
4704 loop - infinite loop on address range
4705 loopw - infinite write loop on address range
4706 mtest - simple RAM test
4707 icache - enable or disable instruction cache
4708 dcache - enable or disable data cache
4709 reset - Perform RESET of the CPU
4710 echo - echo args to console
4711 version - print monitor version
4712 help - print online help
4713 ? - alias for 'help'
4716 Monitor Commands - Detailed Description:
4717 ========================================
4721 For now: just type "help <command>".
4724 Environment Variables:
4725 ======================
4727 U-Boot supports user configuration using Environment Variables which
4728 can be made persistent by saving to Flash memory.
4730 Environment Variables are set using "setenv", printed using
4731 "printenv", and saved to Flash using "saveenv". Using "setenv"
4732 without a value can be used to delete a variable from the
4733 environment. As long as you don't save the environment you are
4734 working with an in-memory copy. In case the Flash area containing the
4735 environment is erased by accident, a default environment is provided.
4737 Some configuration options can be set using Environment Variables.
4739 List of environment variables (most likely not complete):
4741 baudrate - see CONFIG_BAUDRATE
4743 bootdelay - see CONFIG_BOOTDELAY
4745 bootcmd - see CONFIG_BOOTCOMMAND
4747 bootargs - Boot arguments when booting an RTOS image
4749 bootfile - Name of the image to load with TFTP
4751 bootm_low - Memory range available for image processing in the bootm
4752 command can be restricted. This variable is given as
4753 a hexadecimal number and defines lowest address allowed
4754 for use by the bootm command. See also "bootm_size"
4755 environment variable. Address defined by "bootm_low" is
4756 also the base of the initial memory mapping for the Linux
4757 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4760 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4761 This variable is given as a hexadecimal number and it
4762 defines the size of the memory region starting at base
4763 address bootm_low that is accessible by the Linux kernel
4764 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4765 as the default value if it is defined, and bootm_size is
4768 bootm_size - Memory range available for image processing in the bootm
4769 command can be restricted. This variable is given as
4770 a hexadecimal number and defines the size of the region
4771 allowed for use by the bootm command. See also "bootm_low"
4772 environment variable.
4774 updatefile - Location of the software update file on a TFTP server, used
4775 by the automatic software update feature. Please refer to
4776 documentation in doc/README.update for more details.
4778 autoload - if set to "no" (any string beginning with 'n'),
4779 "bootp" will just load perform a lookup of the
4780 configuration from the BOOTP server, but not try to
4781 load any image using TFTP
4783 autostart - if set to "yes", an image loaded using the "bootp",
4784 "rarpboot", "tftpboot" or "diskboot" commands will
4785 be automatically started (by internally calling
4788 If set to "no", a standalone image passed to the
4789 "bootm" command will be copied to the load address
4790 (and eventually uncompressed), but NOT be started.
4791 This can be used to load and uncompress arbitrary
4794 fdt_high - if set this restricts the maximum address that the
4795 flattened device tree will be copied into upon boot.
4796 For example, if you have a system with 1 GB memory
4797 at physical address 0x10000000, while Linux kernel
4798 only recognizes the first 704 MB as low memory, you
4799 may need to set fdt_high as 0x3C000000 to have the
4800 device tree blob be copied to the maximum address
4801 of the 704 MB low memory, so that Linux kernel can
4802 access it during the boot procedure.
4804 If this is set to the special value 0xFFFFFFFF then
4805 the fdt will not be copied at all on boot. For this
4806 to work it must reside in writable memory, have
4807 sufficient padding on the end of it for u-boot to
4808 add the information it needs into it, and the memory
4809 must be accessible by the kernel.
4811 fdtcontroladdr- if set this is the address of the control flattened
4812 device tree used by U-Boot when CONFIG_OF_CONTROL is
4815 i2cfast - (PPC405GP|PPC405EP only)
4816 if set to 'y' configures Linux I2C driver for fast
4817 mode (400kHZ). This environment variable is used in
4818 initialization code. So, for changes to be effective
4819 it must be saved and board must be reset.
4821 initrd_high - restrict positioning of initrd images:
4822 If this variable is not set, initrd images will be
4823 copied to the highest possible address in RAM; this
4824 is usually what you want since it allows for
4825 maximum initrd size. If for some reason you want to
4826 make sure that the initrd image is loaded below the
4827 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4828 variable to a value of "no" or "off" or "0".
4829 Alternatively, you can set it to a maximum upper
4830 address to use (U-Boot will still check that it
4831 does not overwrite the U-Boot stack and data).
4833 For instance, when you have a system with 16 MB
4834 RAM, and want to reserve 4 MB from use by Linux,
4835 you can do this by adding "mem=12M" to the value of
4836 the "bootargs" variable. However, now you must make
4837 sure that the initrd image is placed in the first
4838 12 MB as well - this can be done with
4840 setenv initrd_high 00c00000
4842 If you set initrd_high to 0xFFFFFFFF, this is an
4843 indication to U-Boot that all addresses are legal
4844 for the Linux kernel, including addresses in flash
4845 memory. In this case U-Boot will NOT COPY the
4846 ramdisk at all. This may be useful to reduce the
4847 boot time on your system, but requires that this
4848 feature is supported by your Linux kernel.
4850 ipaddr - IP address; needed for tftpboot command
4852 loadaddr - Default load address for commands like "bootp",
4853 "rarpboot", "tftpboot", "loadb" or "diskboot"
4855 loads_echo - see CONFIG_LOADS_ECHO
4857 serverip - TFTP server IP address; needed for tftpboot command
4859 bootretry - see CONFIG_BOOT_RETRY_TIME
4861 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4863 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4865 ethprime - controls which interface is used first.
4867 ethact - controls which interface is currently active.
4868 For example you can do the following
4870 => setenv ethact FEC
4871 => ping 192.168.0.1 # traffic sent on FEC
4872 => setenv ethact SCC
4873 => ping 10.0.0.1 # traffic sent on SCC
4875 ethrotate - When set to "no" U-Boot does not go through all
4876 available network interfaces.
4877 It just stays at the currently selected interface.
4879 netretry - When set to "no" each network operation will
4880 either succeed or fail without retrying.
4881 When set to "once" the network operation will
4882 fail when all the available network interfaces
4883 are tried once without success.
4884 Useful on scripts which control the retry operation
4887 npe_ucode - set load address for the NPE microcode
4889 silent_linux - If set then linux will be told to boot silently, by
4890 changing the console to be empty. If "yes" it will be
4891 made silent. If "no" it will not be made silent. If
4892 unset, then it will be made silent if the U-Boot console
4895 tftpsrcport - If this is set, the value is used for TFTP's
4898 tftpdstport - If this is set, the value is used for TFTP's UDP
4899 destination port instead of the Well Know Port 69.
4901 tftpblocksize - Block size to use for TFTP transfers; if not set,
4902 we use the TFTP server's default block size
4904 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4905 seconds, minimum value is 1000 = 1 second). Defines
4906 when a packet is considered to be lost so it has to
4907 be retransmitted. The default is 5000 = 5 seconds.
4908 Lowering this value may make downloads succeed
4909 faster in networks with high packet loss rates or
4910 with unreliable TFTP servers.
4912 vlan - When set to a value < 4095 the traffic over
4913 Ethernet is encapsulated/received over 802.1q
4916 The following image location variables contain the location of images
4917 used in booting. The "Image" column gives the role of the image and is
4918 not an environment variable name. The other columns are environment
4919 variable names. "File Name" gives the name of the file on a TFTP
4920 server, "RAM Address" gives the location in RAM the image will be
4921 loaded to, and "Flash Location" gives the image's address in NOR
4922 flash or offset in NAND flash.
4924 *Note* - these variables don't have to be defined for all boards, some
4925 boards currenlty use other variables for these purposes, and some
4926 boards use these variables for other purposes.
4928 Image File Name RAM Address Flash Location
4929 ----- --------- ----------- --------------
4930 u-boot u-boot u-boot_addr_r u-boot_addr
4931 Linux kernel bootfile kernel_addr_r kernel_addr
4932 device tree blob fdtfile fdt_addr_r fdt_addr
4933 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4935 The following environment variables may be used and automatically
4936 updated by the network boot commands ("bootp" and "rarpboot"),
4937 depending the information provided by your boot server:
4939 bootfile - see above
4940 dnsip - IP address of your Domain Name Server
4941 dnsip2 - IP address of your secondary Domain Name Server
4942 gatewayip - IP address of the Gateway (Router) to use
4943 hostname - Target hostname
4945 netmask - Subnet Mask
4946 rootpath - Pathname of the root filesystem on the NFS server
4947 serverip - see above
4950 There are two special Environment Variables:
4952 serial# - contains hardware identification information such
4953 as type string and/or serial number
4954 ethaddr - Ethernet address
4956 These variables can be set only once (usually during manufacturing of
4957 the board). U-Boot refuses to delete or overwrite these variables
4958 once they have been set once.
4961 Further special Environment Variables:
4963 ver - Contains the U-Boot version string as printed
4964 with the "version" command. This variable is
4965 readonly (see CONFIG_VERSION_VARIABLE).
4968 Please note that changes to some configuration parameters may take
4969 only effect after the next boot (yes, that's just like Windoze :-).
4972 Callback functions for environment variables:
4973 ---------------------------------------------
4975 For some environment variables, the behavior of u-boot needs to change
4976 when their values are changed. This functionailty allows functions to
4977 be associated with arbitrary variables. On creation, overwrite, or
4978 deletion, the callback will provide the opportunity for some side
4979 effect to happen or for the change to be rejected.
4981 The callbacks are named and associated with a function using the
4982 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4984 These callbacks are associated with variables in one of two ways. The
4985 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4986 in the board configuration to a string that defines a list of
4987 associations. The list must be in the following format:
4989 entry = variable_name[:callback_name]
4992 If the callback name is not specified, then the callback is deleted.
4993 Spaces are also allowed anywhere in the list.
4995 Callbacks can also be associated by defining the ".callbacks" variable
4996 with the same list format above. Any association in ".callbacks" will
4997 override any association in the static list. You can define
4998 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4999 ".callbacks" envirnoment variable in the default or embedded environment.
5002 Command Line Parsing:
5003 =====================
5005 There are two different command line parsers available with U-Boot:
5006 the old "simple" one, and the much more powerful "hush" shell:
5008 Old, simple command line parser:
5009 --------------------------------
5011 - supports environment variables (through setenv / saveenv commands)
5012 - several commands on one line, separated by ';'
5013 - variable substitution using "... ${name} ..." syntax
5014 - special characters ('$', ';') can be escaped by prefixing with '\',
5016 setenv bootcmd bootm \${address}
5017 - You can also escape text by enclosing in single apostrophes, for example:
5018 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5023 - similar to Bourne shell, with control structures like
5024 if...then...else...fi, for...do...done; while...do...done,
5025 until...do...done, ...
5026 - supports environment ("global") variables (through setenv / saveenv
5027 commands) and local shell variables (through standard shell syntax
5028 "name=value"); only environment variables can be used with "run"
5034 (1) If a command line (or an environment variable executed by a "run"
5035 command) contains several commands separated by semicolon, and
5036 one of these commands fails, then the remaining commands will be
5039 (2) If you execute several variables with one call to run (i. e.
5040 calling run with a list of variables as arguments), any failing
5041 command will cause "run" to terminate, i. e. the remaining
5042 variables are not executed.
5044 Note for Redundant Ethernet Interfaces:
5045 =======================================
5047 Some boards come with redundant Ethernet interfaces; U-Boot supports
5048 such configurations and is capable of automatic selection of a
5049 "working" interface when needed. MAC assignment works as follows:
5051 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5052 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5053 "eth1addr" (=>eth1), "eth2addr", ...
5055 If the network interface stores some valid MAC address (for instance
5056 in SROM), this is used as default address if there is NO correspon-
5057 ding setting in the environment; if the corresponding environment
5058 variable is set, this overrides the settings in the card; that means:
5060 o If the SROM has a valid MAC address, and there is no address in the
5061 environment, the SROM's address is used.
5063 o If there is no valid address in the SROM, and a definition in the
5064 environment exists, then the value from the environment variable is
5067 o If both the SROM and the environment contain a MAC address, and
5068 both addresses are the same, this MAC address is used.
5070 o If both the SROM and the environment contain a MAC address, and the
5071 addresses differ, the value from the environment is used and a
5074 o If neither SROM nor the environment contain a MAC address, an error
5077 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5078 will be programmed into hardware as part of the initialization process. This
5079 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5080 The naming convention is as follows:
5081 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5086 U-Boot is capable of booting (and performing other auxiliary operations on)
5087 images in two formats:
5089 New uImage format (FIT)
5090 -----------------------
5092 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5093 to Flattened Device Tree). It allows the use of images with multiple
5094 components (several kernels, ramdisks, etc.), with contents protected by
5095 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5101 Old image format is based on binary files which can be basically anything,
5102 preceded by a special header; see the definitions in include/image.h for
5103 details; basically, the header defines the following image properties:
5105 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5106 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5107 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5108 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5110 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5111 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5112 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5113 * Compression Type (uncompressed, gzip, bzip2)
5119 The header is marked by a special Magic Number, and both the header
5120 and the data portions of the image are secured against corruption by
5127 Although U-Boot should support any OS or standalone application
5128 easily, the main focus has always been on Linux during the design of
5131 U-Boot includes many features that so far have been part of some
5132 special "boot loader" code within the Linux kernel. Also, any
5133 "initrd" images to be used are no longer part of one big Linux image;
5134 instead, kernel and "initrd" are separate images. This implementation
5135 serves several purposes:
5137 - the same features can be used for other OS or standalone
5138 applications (for instance: using compressed images to reduce the
5139 Flash memory footprint)
5141 - it becomes much easier to port new Linux kernel versions because
5142 lots of low-level, hardware dependent stuff are done by U-Boot
5144 - the same Linux kernel image can now be used with different "initrd"
5145 images; of course this also means that different kernel images can
5146 be run with the same "initrd". This makes testing easier (you don't
5147 have to build a new "zImage.initrd" Linux image when you just
5148 change a file in your "initrd"). Also, a field-upgrade of the
5149 software is easier now.
5155 Porting Linux to U-Boot based systems:
5156 ---------------------------------------
5158 U-Boot cannot save you from doing all the necessary modifications to
5159 configure the Linux device drivers for use with your target hardware
5160 (no, we don't intend to provide a full virtual machine interface to
5163 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5165 Just make sure your machine specific header file (for instance
5166 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5167 Information structure as we define in include/asm-<arch>/u-boot.h,
5168 and make sure that your definition of IMAP_ADDR uses the same value
5169 as your U-Boot configuration in CONFIG_SYS_IMMR.
5172 Configuring the Linux kernel:
5173 -----------------------------
5175 No specific requirements for U-Boot. Make sure you have some root
5176 device (initial ramdisk, NFS) for your target system.
5179 Building a Linux Image:
5180 -----------------------
5182 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5183 not used. If you use recent kernel source, a new build target
5184 "uImage" will exist which automatically builds an image usable by
5185 U-Boot. Most older kernels also have support for a "pImage" target,
5186 which was introduced for our predecessor project PPCBoot and uses a
5187 100% compatible format.
5196 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5197 encapsulate a compressed Linux kernel image with header information,
5198 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5200 * build a standard "vmlinux" kernel image (in ELF binary format):
5202 * convert the kernel into a raw binary image:
5204 ${CROSS_COMPILE}-objcopy -O binary \
5205 -R .note -R .comment \
5206 -S vmlinux linux.bin
5208 * compress the binary image:
5212 * package compressed binary image for U-Boot:
5214 mkimage -A ppc -O linux -T kernel -C gzip \
5215 -a 0 -e 0 -n "Linux Kernel Image" \
5216 -d linux.bin.gz uImage
5219 The "mkimage" tool can also be used to create ramdisk images for use
5220 with U-Boot, either separated from the Linux kernel image, or
5221 combined into one file. "mkimage" encapsulates the images with a 64
5222 byte header containing information about target architecture,
5223 operating system, image type, compression method, entry points, time
5224 stamp, CRC32 checksums, etc.
5226 "mkimage" can be called in two ways: to verify existing images and
5227 print the header information, or to build new images.
5229 In the first form (with "-l" option) mkimage lists the information
5230 contained in the header of an existing U-Boot image; this includes
5231 checksum verification:
5233 tools/mkimage -l image
5234 -l ==> list image header information
5236 The second form (with "-d" option) is used to build a U-Boot image
5237 from a "data file" which is used as image payload:
5239 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5240 -n name -d data_file image
5241 -A ==> set architecture to 'arch'
5242 -O ==> set operating system to 'os'
5243 -T ==> set image type to 'type'
5244 -C ==> set compression type 'comp'
5245 -a ==> set load address to 'addr' (hex)
5246 -e ==> set entry point to 'ep' (hex)
5247 -n ==> set image name to 'name'
5248 -d ==> use image data from 'datafile'
5250 Right now, all Linux kernels for PowerPC systems use the same load
5251 address (0x00000000), but the entry point address depends on the
5254 - 2.2.x kernels have the entry point at 0x0000000C,
5255 - 2.3.x and later kernels have the entry point at 0x00000000.
5257 So a typical call to build a U-Boot image would read:
5259 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5260 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5261 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5262 > examples/uImage.TQM850L
5263 Image Name: 2.4.4 kernel for TQM850L
5264 Created: Wed Jul 19 02:34:59 2000
5265 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5266 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5267 Load Address: 0x00000000
5268 Entry Point: 0x00000000
5270 To verify the contents of the image (or check for corruption):
5272 -> tools/mkimage -l examples/uImage.TQM850L
5273 Image Name: 2.4.4 kernel for TQM850L
5274 Created: Wed Jul 19 02:34:59 2000
5275 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5276 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5277 Load Address: 0x00000000
5278 Entry Point: 0x00000000
5280 NOTE: for embedded systems where boot time is critical you can trade
5281 speed for memory and install an UNCOMPRESSED image instead: this
5282 needs more space in Flash, but boots much faster since it does not
5283 need to be uncompressed:
5285 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5286 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5287 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5288 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5289 > examples/uImage.TQM850L-uncompressed
5290 Image Name: 2.4.4 kernel for TQM850L
5291 Created: Wed Jul 19 02:34:59 2000
5292 Image Type: PowerPC Linux Kernel Image (uncompressed)
5293 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5294 Load Address: 0x00000000
5295 Entry Point: 0x00000000
5298 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5299 when your kernel is intended to use an initial ramdisk:
5301 -> tools/mkimage -n 'Simple Ramdisk Image' \
5302 > -A ppc -O linux -T ramdisk -C gzip \
5303 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5304 Image Name: Simple Ramdisk Image
5305 Created: Wed Jan 12 14:01:50 2000
5306 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5307 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5308 Load Address: 0x00000000
5309 Entry Point: 0x00000000
5311 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5312 option performs the converse operation of the mkimage's second form (the "-d"
5313 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5316 tools/dumpimage -i image -p position data_file
5317 -i ==> extract from the 'image' a specific 'data_file', \
5318 indexed by 'position'
5321 Installing a Linux Image:
5322 -------------------------
5324 To downloading a U-Boot image over the serial (console) interface,
5325 you must convert the image to S-Record format:
5327 objcopy -I binary -O srec examples/image examples/image.srec
5329 The 'objcopy' does not understand the information in the U-Boot
5330 image header, so the resulting S-Record file will be relative to
5331 address 0x00000000. To load it to a given address, you need to
5332 specify the target address as 'offset' parameter with the 'loads'
5335 Example: install the image to address 0x40100000 (which on the
5336 TQM8xxL is in the first Flash bank):
5338 => erase 40100000 401FFFFF
5344 ## Ready for S-Record download ...
5345 ~>examples/image.srec
5346 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5348 15989 15990 15991 15992
5349 [file transfer complete]
5351 ## Start Addr = 0x00000000
5354 You can check the success of the download using the 'iminfo' command;
5355 this includes a checksum verification so you can be sure no data
5356 corruption happened:
5360 ## Checking Image at 40100000 ...
5361 Image Name: 2.2.13 for initrd on TQM850L
5362 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5363 Data Size: 335725 Bytes = 327 kB = 0 MB
5364 Load Address: 00000000
5365 Entry Point: 0000000c
5366 Verifying Checksum ... OK
5372 The "bootm" command is used to boot an application that is stored in
5373 memory (RAM or Flash). In case of a Linux kernel image, the contents
5374 of the "bootargs" environment variable is passed to the kernel as
5375 parameters. You can check and modify this variable using the
5376 "printenv" and "setenv" commands:
5379 => printenv bootargs
5380 bootargs=root=/dev/ram
5382 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5384 => printenv bootargs
5385 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5388 ## Booting Linux kernel at 40020000 ...
5389 Image Name: 2.2.13 for NFS on TQM850L
5390 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5391 Data Size: 381681 Bytes = 372 kB = 0 MB
5392 Load Address: 00000000
5393 Entry Point: 0000000c
5394 Verifying Checksum ... OK
5395 Uncompressing Kernel Image ... OK
5396 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
5397 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5398 time_init: decrementer frequency = 187500000/60
5399 Calibrating delay loop... 49.77 BogoMIPS
5400 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5403 If you want to boot a Linux kernel with initial RAM disk, you pass
5404 the memory addresses of both the kernel and the initrd image (PPBCOOT
5405 format!) to the "bootm" command:
5407 => imi 40100000 40200000
5409 ## Checking Image at 40100000 ...
5410 Image Name: 2.2.13 for initrd on TQM850L
5411 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5412 Data Size: 335725 Bytes = 327 kB = 0 MB
5413 Load Address: 00000000
5414 Entry Point: 0000000c
5415 Verifying Checksum ... OK
5417 ## Checking Image at 40200000 ...
5418 Image Name: Simple Ramdisk Image
5419 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5420 Data Size: 566530 Bytes = 553 kB = 0 MB
5421 Load Address: 00000000
5422 Entry Point: 00000000
5423 Verifying Checksum ... OK
5425 => bootm 40100000 40200000
5426 ## Booting Linux kernel at 40100000 ...
5427 Image Name: 2.2.13 for initrd on TQM850L
5428 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5429 Data Size: 335725 Bytes = 327 kB = 0 MB
5430 Load Address: 00000000
5431 Entry Point: 0000000c
5432 Verifying Checksum ... OK
5433 Uncompressing Kernel Image ... OK
5434 ## Loading RAMDisk Image at 40200000 ...
5435 Image Name: Simple Ramdisk Image
5436 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5437 Data Size: 566530 Bytes = 553 kB = 0 MB
5438 Load Address: 00000000
5439 Entry Point: 00000000
5440 Verifying Checksum ... OK
5441 Loading Ramdisk ... OK
5442 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
5443 Boot arguments: root=/dev/ram
5444 time_init: decrementer frequency = 187500000/60
5445 Calibrating delay loop... 49.77 BogoMIPS
5447 RAMDISK: Compressed image found at block 0
5448 VFS: Mounted root (ext2 filesystem).
5452 Boot Linux and pass a flat device tree:
5455 First, U-Boot must be compiled with the appropriate defines. See the section
5456 titled "Linux Kernel Interface" above for a more in depth explanation. The
5457 following is an example of how to start a kernel and pass an updated
5463 oft=oftrees/mpc8540ads.dtb
5464 => tftp $oftaddr $oft
5465 Speed: 1000, full duplex
5467 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5468 Filename 'oftrees/mpc8540ads.dtb'.
5469 Load address: 0x300000
5472 Bytes transferred = 4106 (100a hex)
5473 => tftp $loadaddr $bootfile
5474 Speed: 1000, full duplex
5476 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5478 Load address: 0x200000
5479 Loading:############
5481 Bytes transferred = 1029407 (fb51f hex)
5486 => bootm $loadaddr - $oftaddr
5487 ## Booting image at 00200000 ...
5488 Image Name: Linux-2.6.17-dirty
5489 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5490 Data Size: 1029343 Bytes = 1005.2 kB
5491 Load Address: 00000000
5492 Entry Point: 00000000
5493 Verifying Checksum ... OK
5494 Uncompressing Kernel Image ... OK
5495 Booting using flat device tree at 0x300000
5496 Using MPC85xx ADS machine description
5497 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5501 More About U-Boot Image Types:
5502 ------------------------------
5504 U-Boot supports the following image types:
5506 "Standalone Programs" are directly runnable in the environment
5507 provided by U-Boot; it is expected that (if they behave
5508 well) you can continue to work in U-Boot after return from
5509 the Standalone Program.
5510 "OS Kernel Images" are usually images of some Embedded OS which
5511 will take over control completely. Usually these programs
5512 will install their own set of exception handlers, device
5513 drivers, set up the MMU, etc. - this means, that you cannot
5514 expect to re-enter U-Boot except by resetting the CPU.
5515 "RAMDisk Images" are more or less just data blocks, and their
5516 parameters (address, size) are passed to an OS kernel that is
5518 "Multi-File Images" contain several images, typically an OS
5519 (Linux) kernel image and one or more data images like
5520 RAMDisks. This construct is useful for instance when you want
5521 to boot over the network using BOOTP etc., where the boot
5522 server provides just a single image file, but you want to get
5523 for instance an OS kernel and a RAMDisk image.
5525 "Multi-File Images" start with a list of image sizes, each
5526 image size (in bytes) specified by an "uint32_t" in network
5527 byte order. This list is terminated by an "(uint32_t)0".
5528 Immediately after the terminating 0 follow the images, one by
5529 one, all aligned on "uint32_t" boundaries (size rounded up to
5530 a multiple of 4 bytes).
5532 "Firmware Images" are binary images containing firmware (like
5533 U-Boot or FPGA images) which usually will be programmed to
5536 "Script files" are command sequences that will be executed by
5537 U-Boot's command interpreter; this feature is especially
5538 useful when you configure U-Boot to use a real shell (hush)
5539 as command interpreter.
5541 Booting the Linux zImage:
5542 -------------------------
5544 On some platforms, it's possible to boot Linux zImage. This is done
5545 using the "bootz" command. The syntax of "bootz" command is the same
5546 as the syntax of "bootm" command.
5548 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5549 kernel with raw initrd images. The syntax is slightly different, the
5550 address of the initrd must be augmented by it's size, in the following
5551 format: "<initrd addres>:<initrd size>".
5557 One of the features of U-Boot is that you can dynamically load and
5558 run "standalone" applications, which can use some resources of
5559 U-Boot like console I/O functions or interrupt services.
5561 Two simple examples are included with the sources:
5566 'examples/hello_world.c' contains a small "Hello World" Demo
5567 application; it is automatically compiled when you build U-Boot.
5568 It's configured to run at address 0x00040004, so you can play with it
5572 ## Ready for S-Record download ...
5573 ~>examples/hello_world.srec
5574 1 2 3 4 5 6 7 8 9 10 11 ...
5575 [file transfer complete]
5577 ## Start Addr = 0x00040004
5579 => go 40004 Hello World! This is a test.
5580 ## Starting application at 0x00040004 ...
5591 Hit any key to exit ...
5593 ## Application terminated, rc = 0x0
5595 Another example, which demonstrates how to register a CPM interrupt
5596 handler with the U-Boot code, can be found in 'examples/timer.c'.
5597 Here, a CPM timer is set up to generate an interrupt every second.
5598 The interrupt service routine is trivial, just printing a '.'
5599 character, but this is just a demo program. The application can be
5600 controlled by the following keys:
5602 ? - print current values og the CPM Timer registers
5603 b - enable interrupts and start timer
5604 e - stop timer and disable interrupts
5605 q - quit application
5608 ## Ready for S-Record download ...
5609 ~>examples/timer.srec
5610 1 2 3 4 5 6 7 8 9 10 11 ...
5611 [file transfer complete]
5613 ## Start Addr = 0x00040004
5616 ## Starting application at 0x00040004 ...
5619 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5622 [q, b, e, ?] Set interval 1000000 us
5625 [q, b, e, ?] ........
5626 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5629 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5632 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5635 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5637 [q, b, e, ?] ...Stopping timer
5639 [q, b, e, ?] ## Application terminated, rc = 0x0
5645 Over time, many people have reported problems when trying to use the
5646 "minicom" terminal emulation program for serial download. I (wd)
5647 consider minicom to be broken, and recommend not to use it. Under
5648 Unix, I recommend to use C-Kermit for general purpose use (and
5649 especially for kermit binary protocol download ("loadb" command), and
5650 use "cu" for S-Record download ("loads" command). See
5651 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5652 for help with kermit.
5655 Nevertheless, if you absolutely want to use it try adding this
5656 configuration to your "File transfer protocols" section:
5658 Name Program Name U/D FullScr IO-Red. Multi
5659 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5660 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5666 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5667 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5669 Building requires a cross environment; it is known to work on
5670 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5671 need gmake since the Makefiles are not compatible with BSD make).
5672 Note that the cross-powerpc package does not install include files;
5673 attempting to build U-Boot will fail because <machine/ansi.h> is
5674 missing. This file has to be installed and patched manually:
5676 # cd /usr/pkg/cross/powerpc-netbsd/include
5678 # ln -s powerpc machine
5679 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5680 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5682 Native builds *don't* work due to incompatibilities between native
5683 and U-Boot include files.
5685 Booting assumes that (the first part of) the image booted is a
5686 stage-2 loader which in turn loads and then invokes the kernel
5687 proper. Loader sources will eventually appear in the NetBSD source
5688 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5689 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5692 Implementation Internals:
5693 =========================
5695 The following is not intended to be a complete description of every
5696 implementation detail. However, it should help to understand the
5697 inner workings of U-Boot and make it easier to port it to custom
5701 Initial Stack, Global Data:
5702 ---------------------------
5704 The implementation of U-Boot is complicated by the fact that U-Boot
5705 starts running out of ROM (flash memory), usually without access to
5706 system RAM (because the memory controller is not initialized yet).
5707 This means that we don't have writable Data or BSS segments, and BSS
5708 is not initialized as zero. To be able to get a C environment working
5709 at all, we have to allocate at least a minimal stack. Implementation
5710 options for this are defined and restricted by the CPU used: Some CPU
5711 models provide on-chip memory (like the IMMR area on MPC8xx and
5712 MPC826x processors), on others (parts of) the data cache can be
5713 locked as (mis-) used as memory, etc.
5715 Chris Hallinan posted a good summary of these issues to the
5716 U-Boot mailing list:
5718 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5719 From: "Chris Hallinan" <clh@net1plus.com>
5720 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5723 Correct me if I'm wrong, folks, but the way I understand it
5724 is this: Using DCACHE as initial RAM for Stack, etc, does not
5725 require any physical RAM backing up the cache. The cleverness
5726 is that the cache is being used as a temporary supply of
5727 necessary storage before the SDRAM controller is setup. It's
5728 beyond the scope of this list to explain the details, but you
5729 can see how this works by studying the cache architecture and
5730 operation in the architecture and processor-specific manuals.
5732 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5733 is another option for the system designer to use as an
5734 initial stack/RAM area prior to SDRAM being available. Either
5735 option should work for you. Using CS 4 should be fine if your
5736 board designers haven't used it for something that would
5737 cause you grief during the initial boot! It is frequently not
5740 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5741 with your processor/board/system design. The default value
5742 you will find in any recent u-boot distribution in
5743 walnut.h should work for you. I'd set it to a value larger
5744 than your SDRAM module. If you have a 64MB SDRAM module, set
5745 it above 400_0000. Just make sure your board has no resources
5746 that are supposed to respond to that address! That code in
5747 start.S has been around a while and should work as is when
5748 you get the config right.
5753 It is essential to remember this, since it has some impact on the C
5754 code for the initialization procedures:
5756 * Initialized global data (data segment) is read-only. Do not attempt
5759 * Do not use any uninitialized global data (or implicitely initialized
5760 as zero data - BSS segment) at all - this is undefined, initiali-
5761 zation is performed later (when relocating to RAM).
5763 * Stack space is very limited. Avoid big data buffers or things like
5766 Having only the stack as writable memory limits means we cannot use
5767 normal global data to share information beween the code. But it
5768 turned out that the implementation of U-Boot can be greatly
5769 simplified by making a global data structure (gd_t) available to all
5770 functions. We could pass a pointer to this data as argument to _all_
5771 functions, but this would bloat the code. Instead we use a feature of
5772 the GCC compiler (Global Register Variables) to share the data: we
5773 place a pointer (gd) to the global data into a register which we
5774 reserve for this purpose.
5776 When choosing a register for such a purpose we are restricted by the
5777 relevant (E)ABI specifications for the current architecture, and by
5778 GCC's implementation.
5780 For PowerPC, the following registers have specific use:
5782 R2: reserved for system use
5783 R3-R4: parameter passing and return values
5784 R5-R10: parameter passing
5785 R13: small data area pointer
5789 (U-Boot also uses R12 as internal GOT pointer. r12
5790 is a volatile register so r12 needs to be reset when
5791 going back and forth between asm and C)
5793 ==> U-Boot will use R2 to hold a pointer to the global data
5795 Note: on PPC, we could use a static initializer (since the
5796 address of the global data structure is known at compile time),
5797 but it turned out that reserving a register results in somewhat
5798 smaller code - although the code savings are not that big (on
5799 average for all boards 752 bytes for the whole U-Boot image,
5800 624 text + 127 data).
5802 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5803 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5805 ==> U-Boot will use P3 to hold a pointer to the global data
5807 On ARM, the following registers are used:
5809 R0: function argument word/integer result
5810 R1-R3: function argument word
5811 R9: platform specific
5812 R10: stack limit (used only if stack checking is enabled)
5813 R11: argument (frame) pointer
5814 R12: temporary workspace
5817 R15: program counter
5819 ==> U-Boot will use R9 to hold a pointer to the global data
5821 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5823 On Nios II, the ABI is documented here:
5824 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5826 ==> U-Boot will use gp to hold a pointer to the global data
5828 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5829 to access small data sections, so gp is free.
5831 On NDS32, the following registers are used:
5833 R0-R1: argument/return
5835 R15: temporary register for assembler
5836 R16: trampoline register
5837 R28: frame pointer (FP)
5838 R29: global pointer (GP)
5839 R30: link register (LP)
5840 R31: stack pointer (SP)
5841 PC: program counter (PC)
5843 ==> U-Boot will use R10 to hold a pointer to the global data
5845 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5846 or current versions of GCC may "optimize" the code too much.
5851 U-Boot runs in system state and uses physical addresses, i.e. the
5852 MMU is not used either for address mapping nor for memory protection.
5854 The available memory is mapped to fixed addresses using the memory
5855 controller. In this process, a contiguous block is formed for each
5856 memory type (Flash, SDRAM, SRAM), even when it consists of several
5857 physical memory banks.
5859 U-Boot is installed in the first 128 kB of the first Flash bank (on
5860 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5861 booting and sizing and initializing DRAM, the code relocates itself
5862 to the upper end of DRAM. Immediately below the U-Boot code some
5863 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5864 configuration setting]. Below that, a structure with global Board
5865 Info data is placed, followed by the stack (growing downward).
5867 Additionally, some exception handler code is copied to the low 8 kB
5868 of DRAM (0x00000000 ... 0x00001FFF).
5870 So a typical memory configuration with 16 MB of DRAM could look like
5873 0x0000 0000 Exception Vector code
5876 0x0000 2000 Free for Application Use
5882 0x00FB FF20 Monitor Stack (Growing downward)
5883 0x00FB FFAC Board Info Data and permanent copy of global data
5884 0x00FC 0000 Malloc Arena
5887 0x00FE 0000 RAM Copy of Monitor Code
5888 ... eventually: LCD or video framebuffer
5889 ... eventually: pRAM (Protected RAM - unchanged by reset)
5890 0x00FF FFFF [End of RAM]
5893 System Initialization:
5894 ----------------------
5896 In the reset configuration, U-Boot starts at the reset entry point
5897 (on most PowerPC systems at address 0x00000100). Because of the reset
5898 configuration for CS0# this is a mirror of the onboard Flash memory.
5899 To be able to re-map memory U-Boot then jumps to its link address.
5900 To be able to implement the initialization code in C, a (small!)
5901 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5902 which provide such a feature like MPC8xx or MPC8260), or in a locked
5903 part of the data cache. After that, U-Boot initializes the CPU core,
5904 the caches and the SIU.
5906 Next, all (potentially) available memory banks are mapped using a
5907 preliminary mapping. For example, we put them on 512 MB boundaries
5908 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5909 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5910 programmed for SDRAM access. Using the temporary configuration, a
5911 simple memory test is run that determines the size of the SDRAM
5914 When there is more than one SDRAM bank, and the banks are of
5915 different size, the largest is mapped first. For equal size, the first
5916 bank (CS2#) is mapped first. The first mapping is always for address
5917 0x00000000, with any additional banks following immediately to create
5918 contiguous memory starting from 0.
5920 Then, the monitor installs itself at the upper end of the SDRAM area
5921 and allocates memory for use by malloc() and for the global Board
5922 Info data; also, the exception vector code is copied to the low RAM
5923 pages, and the final stack is set up.
5925 Only after this relocation will you have a "normal" C environment;
5926 until that you are restricted in several ways, mostly because you are
5927 running from ROM, and because the code will have to be relocated to a
5931 U-Boot Porting Guide:
5932 ----------------------
5934 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5938 int main(int argc, char *argv[])
5940 sighandler_t no_more_time;
5942 signal(SIGALRM, no_more_time);
5943 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5945 if (available_money > available_manpower) {
5946 Pay consultant to port U-Boot;
5950 Download latest U-Boot source;
5952 Subscribe to u-boot mailing list;
5955 email("Hi, I am new to U-Boot, how do I get started?");
5958 Read the README file in the top level directory;
5959 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5960 Read applicable doc/*.README;
5961 Read the source, Luke;
5962 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5965 if (available_money > toLocalCurrency ($2500))
5968 Add a lot of aggravation and time;
5970 if (a similar board exists) { /* hopefully... */
5971 cp -a board/<similar> board/<myboard>
5972 cp include/configs/<similar>.h include/configs/<myboard>.h
5974 Create your own board support subdirectory;
5975 Create your own board include/configs/<myboard>.h file;
5977 Edit new board/<myboard> files
5978 Edit new include/configs/<myboard>.h
5983 Add / modify source code;
5987 email("Hi, I am having problems...");
5989 Send patch file to the U-Boot email list;
5990 if (reasonable critiques)
5991 Incorporate improvements from email list code review;
5993 Defend code as written;
5999 void no_more_time (int sig)
6008 All contributions to U-Boot should conform to the Linux kernel
6009 coding style; see the file "Documentation/CodingStyle" and the script
6010 "scripts/Lindent" in your Linux kernel source directory.
6012 Source files originating from a different project (for example the
6013 MTD subsystem) are generally exempt from these guidelines and are not
6014 reformated to ease subsequent migration to newer versions of those
6017 Please note that U-Boot is implemented in C (and to some small parts in
6018 Assembler); no C++ is used, so please do not use C++ style comments (//)
6021 Please also stick to the following formatting rules:
6022 - remove any trailing white space
6023 - use TAB characters for indentation and vertical alignment, not spaces
6024 - make sure NOT to use DOS '\r\n' line feeds
6025 - do not add more than 2 consecutive empty lines to source files
6026 - do not add trailing empty lines to source files
6028 Submissions which do not conform to the standards may be returned
6029 with a request to reformat the changes.
6035 Since the number of patches for U-Boot is growing, we need to
6036 establish some rules. Submissions which do not conform to these rules
6037 may be rejected, even when they contain important and valuable stuff.
6039 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6041 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6042 see http://lists.denx.de/mailman/listinfo/u-boot
6044 When you send a patch, please include the following information with
6047 * For bug fixes: a description of the bug and how your patch fixes
6048 this bug. Please try to include a way of demonstrating that the
6049 patch actually fixes something.
6051 * For new features: a description of the feature and your
6054 * A CHANGELOG entry as plaintext (separate from the patch)
6056 * For major contributions, your entry to the CREDITS file
6058 * When you add support for a new board, don't forget to add a
6059 maintainer e-mail address to the boards.cfg file, too.
6061 * If your patch adds new configuration options, don't forget to
6062 document these in the README file.
6064 * The patch itself. If you are using git (which is *strongly*
6065 recommended) you can easily generate the patch using the
6066 "git format-patch". If you then use "git send-email" to send it to
6067 the U-Boot mailing list, you will avoid most of the common problems
6068 with some other mail clients.
6070 If you cannot use git, use "diff -purN OLD NEW". If your version of
6071 diff does not support these options, then get the latest version of
6074 The current directory when running this command shall be the parent
6075 directory of the U-Boot source tree (i. e. please make sure that
6076 your patch includes sufficient directory information for the
6079 We prefer patches as plain text. MIME attachments are discouraged,
6080 and compressed attachments must not be used.
6082 * If one logical set of modifications affects or creates several
6083 files, all these changes shall be submitted in a SINGLE patch file.
6085 * Changesets that contain different, unrelated modifications shall be
6086 submitted as SEPARATE patches, one patch per changeset.
6091 * Before sending the patch, run the MAKEALL script on your patched
6092 source tree and make sure that no errors or warnings are reported
6093 for any of the boards.
6095 * Keep your modifications to the necessary minimum: A patch
6096 containing several unrelated changes or arbitrary reformats will be
6097 returned with a request to re-formatting / split it.
6099 * If you modify existing code, make sure that your new code does not
6100 add to the memory footprint of the code ;-) Small is beautiful!
6101 When adding new features, these should compile conditionally only
6102 (using #ifdef), and the resulting code with the new feature
6103 disabled must not need more memory than the old code without your
6106 * Remember that there is a size limit of 100 kB per message on the
6107 u-boot mailing list. Bigger patches will be moderated. If they are
6108 reasonable and not too big, they will be acknowledged. But patches
6109 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob