2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /xburst Files specific to Ingenic XBurst CPUs
185 /lib Architecture specific library files
186 /nds32 Files generic to NDS32 architecture
187 /cpu CPU specific files
188 /n1213 Files specific to Andes Technology N1213 CPUs
189 /lib Architecture specific library files
190 /nios2 Files generic to Altera NIOS2 architecture
191 /cpu CPU specific files
192 /lib Architecture specific library files
193 /powerpc Files generic to PowerPC architecture
194 /cpu CPU specific files
195 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
196 /mpc5xx Files specific to Freescale MPC5xx CPUs
197 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
198 /mpc8xx Files specific to Freescale MPC8xx CPUs
199 /mpc8220 Files specific to Freescale MPC8220 CPUs
200 /mpc824x Files specific to Freescale MPC824x CPUs
201 /mpc8260 Files specific to Freescale MPC8260 CPUs
202 /mpc85xx Files specific to Freescale MPC85xx CPUs
203 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
204 /lib Architecture specific library files
205 /sh Files generic to SH architecture
206 /cpu CPU specific files
207 /sh2 Files specific to sh2 CPUs
208 /sh3 Files specific to sh3 CPUs
209 /sh4 Files specific to sh4 CPUs
210 /lib Architecture specific library files
211 /sparc Files generic to SPARC architecture
212 /cpu CPU specific files
213 /leon2 Files specific to Gaisler LEON2 SPARC CPU
214 /leon3 Files specific to Gaisler LEON3 SPARC CPU
215 /lib Architecture specific library files
216 /api Machine/arch independent API for external apps
217 /board Board dependent files
218 /common Misc architecture independent functions
219 /disk Code for disk drive partition handling
220 /doc Documentation (don't expect too much)
221 /drivers Commonly used device drivers
222 /examples Example code for standalone applications, etc.
223 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
224 /include Header Files
225 /lib Files generic to all architectures
226 /libfdt Library files to support flattened device trees
227 /lzma Library files to support LZMA decompression
228 /lzo Library files to support LZO decompression
230 /post Power On Self Test
231 /rtc Real Time Clock drivers
232 /tools Tools to build S-Record or U-Boot images, etc.
234 Software Configuration:
235 =======================
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
240 There are two classes of configuration variables:
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
246 * Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
251 Later we will add a configuration tool - probably similar to or even
252 identical to what's used for the Linux kernel. Right now, we have to
253 do the configuration by hand, which means creating some symbolic
254 links and editing some configuration files. We use the TQM8xxL boards
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
264 Example: For a TQM823L module type:
269 For the Cogent platform, you need to specify the CPU type as well;
270 e.g. "make cogent_mpc8xx_config". And also configure the cogent
271 directory according to the instructions in cogent/README.
274 Configuration Options:
275 ----------------------
277 Configuration depends on the combination of board and CPU type; all
278 such information is kept in a configuration file
279 "include/configs/<board_name>.h".
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
285 Many of the options are named exactly as the corresponding Linux
286 kernel configuration options. The intention is to make it easier to
287 build a config tool - later.
290 The following options need to be configured:
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
299 - CPU Module Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
302 --- FIXME --- not tested yet:
303 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
304 CONFIG_CMA287_23, CONFIG_CMA287_50
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
314 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
315 Define one or more of
316 CONFIG_LCD_HEARTBEAT - update a character position on
317 the LCD display every second with
320 - Board flavour: (if CONFIG_MPC8260ADS is defined)
323 CONFIG_SYS_8260ADS - original MPC8260ADS
324 CONFIG_SYS_8266ADS - MPC8266ADS
325 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
326 CONFIG_SYS_8272ADS - MPC8272ADS
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
337 - 8xx CPU Options: (if using an MPC8xx CPU)
338 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
339 get_gclk_freq() cannot work
340 e.g. if there is no 32KHz
341 reference PIT/RTC clock
342 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
345 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
346 CONFIG_SYS_8xx_CPUCLK_MIN
347 CONFIG_SYS_8xx_CPUCLK_MAX
348 CONFIG_8xx_CPUCLK_DEFAULT
349 See doc/README.MPC866
351 CONFIG_SYS_MEASURE_CPUCLK
353 Define this to measure the actual CPU clock instead
354 of relying on the correctness of the configured
355 values. Mostly useful for board bringup to make sure
356 the PLL is locked at the intended frequency. Note
357 that this requires a (stable) reference clock (32 kHz
358 RTC clock or CONFIG_SYS_8XX_XIN)
360 CONFIG_SYS_DELAYED_ICACHE
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
366 CONFIG_SYS_FSL_TBCLK_DIV
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
372 CONFIG_SYS_FSL_PCIE_COMPAT
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
377 - Generic CPU options:
378 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
380 Defines the endianess of the CPU. Implementation of those
381 values is arch specific.
383 - Intel Monahans options:
384 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
386 Defines the Monahans run mode to oscillator
387 ratio. Valid values are 8, 16, 24, 31. The core
388 frequency is this value multiplied by 13 MHz.
390 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
392 Defines the Monahans turbo mode to oscillator
393 ratio. Valid values are 1 (default if undefined) and
394 2. The core frequency as calculated above is multiplied
398 CONFIG_SYS_INIT_SP_OFFSET
400 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
401 pointer. This is needed for the temporary stack before
404 CONFIG_SYS_MIPS_CACHE_MODE
406 Cache operation mode for the MIPS CPU.
407 See also arch/mips/include/asm/mipsregs.h.
409 CONF_CM_CACHABLE_NO_WA
412 CONF_CM_CACHABLE_NONCOHERENT
416 CONF_CM_CACHABLE_ACCELERATED
418 CONFIG_SYS_XWAY_EBU_BOOTCFG
420 Special option for Lantiq XWAY SoCs for booting from NOR flash.
421 See also arch/mips/cpu/mips32/start.S.
423 CONFIG_XWAY_SWAP_BYTES
425 Enable compilation of tools/xway-swap-bytes needed for Lantiq
426 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
427 be swapped if a flash programmer is used.
430 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
432 Select high exception vectors of the ARM core, e.g., do not
433 clear the V bit of the c1 register of CP15.
435 CONFIG_SYS_THUMB_BUILD
437 Use this flag to build U-Boot using the Thumb instruction
438 set for ARM architectures. Thumb instruction set provides
439 better code density. For ARM architectures that support
440 Thumb2 this flag will result in Thumb2 code generated by
443 - Linux Kernel Interface:
446 U-Boot stores all clock information in Hz
447 internally. For binary compatibility with older Linux
448 kernels (which expect the clocks passed in the
449 bd_info data to be in MHz) the environment variable
450 "clocks_in_mhz" can be defined so that U-Boot
451 converts clock data to MHZ before passing it to the
453 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
454 "clocks_in_mhz=1" is automatically included in the
457 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
459 When transferring memsize parameter to linux, some versions
460 expect it to be in bytes, others in MB.
461 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
465 New kernel versions are expecting firmware settings to be
466 passed using flattened device trees (based on open firmware
470 * New libfdt-based support
471 * Adds the "fdt" command
472 * The bootm command automatically updates the fdt
474 OF_CPU - The proper name of the cpus node (only required for
475 MPC512X and MPC5xxx based boards).
476 OF_SOC - The proper name of the soc node (only required for
477 MPC512X and MPC5xxx based boards).
478 OF_TBCLK - The timebase frequency.
479 OF_STDOUT_PATH - The path to the console device
481 boards with QUICC Engines require OF_QE to set UCC MAC
484 CONFIG_OF_BOARD_SETUP
486 Board code has addition modification that it wants to make
487 to the flat device tree before handing it off to the kernel
491 This define fills in the correct boot CPU in the boot
492 param header, the default value is zero if undefined.
496 U-Boot can detect if an IDE device is present or not.
497 If not, and this new config option is activated, U-Boot
498 removes the ATA node from the DTS before booting Linux,
499 so the Linux IDE driver does not probe the device and
500 crash. This is needed for buggy hardware (uc101) where
501 no pull down resistor is connected to the signal IDE5V_DD7.
503 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
505 This setting is mandatory for all boards that have only one
506 machine type and must be used to specify the machine type
507 number as it appears in the ARM machine registry
508 (see http://www.arm.linux.org.uk/developer/machines/).
509 Only boards that have multiple machine types supported
510 in a single configuration file and the machine type is
511 runtime discoverable, do not have to use this setting.
513 - vxWorks boot parameters:
515 bootvx constructs a valid bootline using the following
516 environments variables: bootfile, ipaddr, serverip, hostname.
517 It loads the vxWorks image pointed bootfile.
519 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
520 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
521 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
522 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
524 CONFIG_SYS_VXWORKS_ADD_PARAMS
526 Add it at the end of the bootline. E.g "u=username pw=secret"
528 Note: If a "bootargs" environment is defined, it will overwride
529 the defaults discussed just above.
531 - Cache Configuration:
532 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
533 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
534 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
536 - Cache Configuration for ARM:
537 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
539 CONFIG_SYS_PL310_BASE - Physical base address of PL310
540 controller register space
545 Define this if you want support for Amba PrimeCell PL010 UARTs.
549 Define this if you want support for Amba PrimeCell PL011 UARTs.
553 If you have Amba PrimeCell PL011 UARTs, set this variable to
554 the clock speed of the UARTs.
558 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
559 define this to a list of base addresses for each (supported)
560 port. See e.g. include/configs/versatile.h
562 CONFIG_PL011_SERIAL_RLCR
564 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
565 have separate receive and transmit line control registers. Set
566 this variable to initialize the extra register.
568 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
570 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
571 boot loader that has already initialized the UART. Define this
572 variable to flush the UART at init time.
576 Depending on board, define exactly one serial port
577 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
578 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
579 console by defining CONFIG_8xx_CONS_NONE
581 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
582 port routines must be defined elsewhere
583 (i.e. serial_init(), serial_getc(), ...)
586 Enables console device for a color framebuffer. Needs following
587 defines (cf. smiLynxEM, i8042)
588 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
590 VIDEO_HW_RECTFILL graphic chip supports
593 VIDEO_HW_BITBLT graphic chip supports
594 bit-blit (cf. smiLynxEM)
595 VIDEO_VISIBLE_COLS visible pixel columns
597 VIDEO_VISIBLE_ROWS visible pixel rows
598 VIDEO_PIXEL_SIZE bytes per pixel
599 VIDEO_DATA_FORMAT graphic data format
600 (0-5, cf. cfb_console.c)
601 VIDEO_FB_ADRS framebuffer address
602 VIDEO_KBD_INIT_FCT keyboard int fct
603 (i.e. i8042_kbd_init())
604 VIDEO_TSTC_FCT test char fct
606 VIDEO_GETC_FCT get char fct
608 CONFIG_CONSOLE_CURSOR cursor drawing on/off
609 (requires blink timer
611 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
612 CONFIG_CONSOLE_TIME display time/date info in
614 (requires CONFIG_CMD_DATE)
615 CONFIG_VIDEO_LOGO display Linux logo in
617 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
618 linux_logo.h for logo.
619 Requires CONFIG_VIDEO_LOGO
620 CONFIG_CONSOLE_EXTRA_INFO
621 additional board info beside
624 When CONFIG_CFB_CONSOLE is defined, video console is
625 default i/o. Serial console can be forced with
626 environment 'console=serial'.
628 When CONFIG_SILENT_CONSOLE is defined, all console
629 messages (by U-Boot and Linux!) can be silenced with
630 the "silent" environment variable. See
631 doc/README.silent for more information.
634 CONFIG_BAUDRATE - in bps
635 Select one of the baudrates listed in
636 CONFIG_SYS_BAUDRATE_TABLE, see below.
637 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
639 - Console Rx buffer length
640 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
641 the maximum receive buffer length for the SMC.
642 This option is actual only for 82xx and 8xx possible.
643 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
644 must be defined, to setup the maximum idle timeout for
647 - Pre-Console Buffer:
648 Prior to the console being initialised (i.e. serial UART
649 initialised etc) all console output is silently discarded.
650 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
651 buffer any console messages prior to the console being
652 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
653 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
654 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
655 bytes are output before the console is initialised, the
656 earlier bytes are discarded.
658 'Sane' compilers will generate smaller code if
659 CONFIG_PRE_CON_BUF_SZ is a power of 2
661 - Safe printf() functions
662 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
663 the printf() functions. These are defined in
664 include/vsprintf.h and include snprintf(), vsnprintf() and
665 so on. Code size increase is approximately 300-500 bytes.
666 If this option is not given then these functions will
667 silently discard their buffer size argument - this means
668 you are not getting any overflow checking in this case.
670 - Boot Delay: CONFIG_BOOTDELAY - in seconds
671 Delay before automatically booting the default image;
672 set to -1 to disable autoboot.
674 See doc/README.autoboot for these options that
675 work with CONFIG_BOOTDELAY. None are required.
676 CONFIG_BOOT_RETRY_TIME
677 CONFIG_BOOT_RETRY_MIN
678 CONFIG_AUTOBOOT_KEYED
679 CONFIG_AUTOBOOT_PROMPT
680 CONFIG_AUTOBOOT_DELAY_STR
681 CONFIG_AUTOBOOT_STOP_STR
682 CONFIG_AUTOBOOT_DELAY_STR2
683 CONFIG_AUTOBOOT_STOP_STR2
684 CONFIG_ZERO_BOOTDELAY_CHECK
685 CONFIG_RESET_TO_RETRY
689 Only needed when CONFIG_BOOTDELAY is enabled;
690 define a command string that is automatically executed
691 when no character is read on the console interface
692 within "Boot Delay" after reset.
695 This can be used to pass arguments to the bootm
696 command. The value of CONFIG_BOOTARGS goes into the
697 environment value "bootargs".
699 CONFIG_RAMBOOT and CONFIG_NFSBOOT
700 The value of these goes into the environment as
701 "ramboot" and "nfsboot" respectively, and can be used
702 as a convenience, when switching between booting from
708 When this option is #defined, the existence of the
709 environment variable "preboot" will be checked
710 immediately before starting the CONFIG_BOOTDELAY
711 countdown and/or running the auto-boot command resp.
712 entering interactive mode.
714 This feature is especially useful when "preboot" is
715 automatically generated or modified. For an example
716 see the LWMON board specific code: here "preboot" is
717 modified when the user holds down a certain
718 combination of keys on the (special) keyboard when
721 - Serial Download Echo Mode:
723 If defined to 1, all characters received during a
724 serial download (using the "loads" command) are
725 echoed back. This might be needed by some terminal
726 emulations (like "cu"), but may as well just take
727 time on others. This setting #define's the initial
728 value of the "loads_echo" environment variable.
730 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
732 Select one of the baudrates listed in
733 CONFIG_SYS_BAUDRATE_TABLE, see below.
736 Monitor commands can be included or excluded
737 from the build by using the #include files
738 "config_cmd_all.h" and #undef'ing unwanted
739 commands, or using "config_cmd_default.h"
740 and augmenting with additional #define's
743 The default command configuration includes all commands
744 except those marked below with a "*".
746 CONFIG_CMD_ASKENV * ask for env variable
747 CONFIG_CMD_BDI bdinfo
748 CONFIG_CMD_BEDBUG * Include BedBug Debugger
749 CONFIG_CMD_BMP * BMP support
750 CONFIG_CMD_BSP * Board specific commands
751 CONFIG_CMD_BOOTD bootd
752 CONFIG_CMD_CACHE * icache, dcache
753 CONFIG_CMD_CONSOLE coninfo
754 CONFIG_CMD_CRC32 * crc32
755 CONFIG_CMD_DATE * support for RTC, date/time...
756 CONFIG_CMD_DHCP * DHCP support
757 CONFIG_CMD_DIAG * Diagnostics
758 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
759 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
760 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
761 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
762 CONFIG_CMD_DTT * Digital Therm and Thermostat
763 CONFIG_CMD_ECHO echo arguments
764 CONFIG_CMD_EDITENV edit env variable
765 CONFIG_CMD_EEPROM * EEPROM read/write support
766 CONFIG_CMD_ELF * bootelf, bootvx
767 CONFIG_CMD_EXPORTENV * export the environment
768 CONFIG_CMD_SAVEENV saveenv
769 CONFIG_CMD_FDC * Floppy Disk Support
770 CONFIG_CMD_FAT * FAT partition support
771 CONFIG_CMD_FDOS * Dos diskette Support
772 CONFIG_CMD_FLASH flinfo, erase, protect
773 CONFIG_CMD_FPGA FPGA device initialization support
774 CONFIG_CMD_GO * the 'go' command (exec code)
775 CONFIG_CMD_GREPENV * search environment
776 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
777 CONFIG_CMD_I2C * I2C serial bus support
778 CONFIG_CMD_IDE * IDE harddisk support
779 CONFIG_CMD_IMI iminfo
780 CONFIG_CMD_IMLS List all found images
781 CONFIG_CMD_IMMAP * IMMR dump support
782 CONFIG_CMD_IMPORTENV * import an environment
783 CONFIG_CMD_IRQ * irqinfo
784 CONFIG_CMD_ITEST Integer/string test of 2 values
785 CONFIG_CMD_JFFS2 * JFFS2 Support
786 CONFIG_CMD_KGDB * kgdb
787 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
788 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
790 CONFIG_CMD_LOADB loadb
791 CONFIG_CMD_LOADS loads
792 CONFIG_CMD_MD5SUM print md5 message digest
793 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
794 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
796 CONFIG_CMD_MISC Misc functions like sleep etc
797 CONFIG_CMD_MMC * MMC memory mapped support
798 CONFIG_CMD_MII * MII utility commands
799 CONFIG_CMD_MTDPARTS * MTD partition support
800 CONFIG_CMD_NAND * NAND support
801 CONFIG_CMD_NET bootp, tftpboot, rarpboot
802 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
803 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
804 CONFIG_CMD_PCI * pciinfo
805 CONFIG_CMD_PCMCIA * PCMCIA support
806 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
808 CONFIG_CMD_PORTIO * Port I/O
809 CONFIG_CMD_REGINFO * Register dump
810 CONFIG_CMD_RUN run command in env variable
811 CONFIG_CMD_SAVES * save S record dump
812 CONFIG_CMD_SCSI * SCSI Support
813 CONFIG_CMD_SDRAM * print SDRAM configuration information
814 (requires CONFIG_CMD_I2C)
815 CONFIG_CMD_SETGETDCR Support for DCR Register access
817 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
818 CONFIG_CMD_SHA1SUM print sha1 memory digest
819 (requires CONFIG_CMD_MEMORY)
820 CONFIG_CMD_SOURCE "source" command Support
821 CONFIG_CMD_SPI * SPI serial bus support
822 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
823 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
824 CONFIG_CMD_TIME * run command and report execution time
825 CONFIG_CMD_USB * USB support
826 CONFIG_CMD_CDP * Cisco Discover Protocol support
827 CONFIG_CMD_MFSL * Microblaze FSL support
830 EXAMPLE: If you want all functions except of network
831 support you can write:
833 #include "config_cmd_all.h"
834 #undef CONFIG_CMD_NET
837 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
839 Note: Don't enable the "icache" and "dcache" commands
840 (configuration option CONFIG_CMD_CACHE) unless you know
841 what you (and your U-Boot users) are doing. Data
842 cache cannot be enabled on systems like the 8xx or
843 8260 (where accesses to the IMMR region must be
844 uncached), and it cannot be disabled on all other
845 systems where we (mis-) use the data cache to hold an
846 initial stack and some data.
849 XXX - this list needs to get updated!
853 If this variable is defined, U-Boot will use a device tree
854 to configure its devices, instead of relying on statically
855 compiled #defines in the board file. This option is
856 experimental and only available on a few boards. The device
857 tree is available in the global data as gd->fdt_blob.
859 U-Boot needs to get its device tree from somewhere. This can
860 be done using one of the two options below:
863 If this variable is defined, U-Boot will embed a device tree
864 binary in its image. This device tree file should be in the
865 board directory and called <soc>-<board>.dts. The binary file
866 is then picked up in board_init_f() and made available through
867 the global data structure as gd->blob.
870 If this variable is defined, U-Boot will build a device tree
871 binary. It will be called u-boot.dtb. Architecture-specific
872 code will locate it at run-time. Generally this works by:
874 cat u-boot.bin u-boot.dtb >image.bin
876 and in fact, U-Boot does this for you, creating a file called
877 u-boot-dtb.bin which is useful in the common case. You can
878 still use the individual files if you need something more
883 If this variable is defined, it enables watchdog
884 support for the SoC. There must be support in the SoC
885 specific code for a watchdog. For the 8xx and 8260
886 CPUs, the SIU Watchdog feature is enabled in the SYPCR
887 register. When supported for a specific SoC is
888 available, then no further board specific code should
892 When using a watchdog circuitry external to the used
893 SoC, then define this variable and provide board
894 specific code for the "hw_watchdog_reset" function.
897 CONFIG_VERSION_VARIABLE
898 If this variable is defined, an environment variable
899 named "ver" is created by U-Boot showing the U-Boot
900 version as printed by the "version" command.
901 This variable is readonly.
905 When CONFIG_CMD_DATE is selected, the type of the RTC
906 has to be selected, too. Define exactly one of the
909 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
910 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
911 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
912 CONFIG_RTC_MC146818 - use MC146818 RTC
913 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
914 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
915 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
916 CONFIG_RTC_DS164x - use Dallas DS164x RTC
917 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
918 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
919 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
920 CONFIG_SYS_RV3029_TCR - enable trickle charger on
923 Note that if the RTC uses I2C, then the I2C interface
924 must also be configured. See I2C Support, below.
927 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
928 CONFIG_PCA953X_INFO - enable pca953x info command
930 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
931 chip-ngpio pairs that tell the PCA953X driver the number of
932 pins supported by a particular chip.
934 Note that if the GPIO device uses I2C, then the I2C interface
935 must also be configured. See I2C Support, below.
939 When CONFIG_TIMESTAMP is selected, the timestamp
940 (date and time) of an image is printed by image
941 commands like bootm or iminfo. This option is
942 automatically enabled when you select CONFIG_CMD_DATE .
945 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
946 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
948 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
949 CONFIG_CMD_SCSI) you must configure support for at
950 least one partition type as well.
953 CONFIG_IDE_RESET_ROUTINE - this is defined in several
954 board configurations files but used nowhere!
956 CONFIG_IDE_RESET - is this is defined, IDE Reset will
957 be performed by calling the function
958 ide_set_reset(int reset)
959 which has to be defined in a board specific file
964 Set this to enable ATAPI support.
969 Set this to enable support for disks larger than 137GB
970 Also look at CONFIG_SYS_64BIT_LBA.
971 Whithout these , LBA48 support uses 32bit variables and will 'only'
972 support disks up to 2.1TB.
974 CONFIG_SYS_64BIT_LBA:
975 When enabled, makes the IDE subsystem use 64bit sector addresses.
979 At the moment only there is only support for the
980 SYM53C8XX SCSI controller; define
981 CONFIG_SCSI_SYM53C8XX to enable it.
983 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
984 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
985 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
986 maximum numbers of LUNs, SCSI ID's and target
988 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
990 - NETWORK Support (PCI):
992 Support for Intel 8254x/8257x gigabit chips.
995 Utility code for direct access to the SPI bus on Intel 8257x.
996 This does not do anything useful unless you set at least one
997 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
999 CONFIG_E1000_SPI_GENERIC
1000 Allow generic access to the SPI bus on the Intel 8257x, for
1001 example with the "sspi" command.
1004 Management command for E1000 devices. When used on devices
1005 with SPI support you can reprogram the EEPROM from U-Boot.
1007 CONFIG_E1000_FALLBACK_MAC
1008 default MAC for empty EEPROM after production.
1011 Support for Intel 82557/82559/82559ER chips.
1012 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1013 write routine for first time initialisation.
1016 Support for Digital 2114x chips.
1017 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1018 modem chip initialisation (KS8761/QS6611).
1021 Support for National dp83815 chips.
1024 Support for National dp8382[01] gigabit chips.
1026 - NETWORK Support (other):
1028 CONFIG_DRIVER_AT91EMAC
1029 Support for AT91RM9200 EMAC.
1032 Define this to use reduced MII inteface
1034 CONFIG_DRIVER_AT91EMAC_QUIET
1035 If this defined, the driver is quiet.
1036 The driver doen't show link status messages.
1038 CONFIG_CALXEDA_XGMAC
1039 Support for the Calxeda XGMAC device
1041 CONFIG_DRIVER_LAN91C96
1042 Support for SMSC's LAN91C96 chips.
1044 CONFIG_LAN91C96_BASE
1045 Define this to hold the physical address
1046 of the LAN91C96's I/O space
1048 CONFIG_LAN91C96_USE_32_BIT
1049 Define this to enable 32 bit addressing
1051 CONFIG_DRIVER_SMC91111
1052 Support for SMSC's LAN91C111 chip
1054 CONFIG_SMC91111_BASE
1055 Define this to hold the physical address
1056 of the device (I/O space)
1058 CONFIG_SMC_USE_32_BIT
1059 Define this if data bus is 32 bits
1061 CONFIG_SMC_USE_IOFUNCS
1062 Define this to use i/o functions instead of macros
1063 (some hardware wont work with macros)
1065 CONFIG_DRIVER_TI_EMAC
1066 Support for davinci emac
1068 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1069 Define this if you have more then 3 PHYs.
1072 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1074 CONFIG_FTGMAC100_EGIGA
1075 Define this to use GE link update with gigabit PHY.
1076 Define this if FTGMAC100 is connected to gigabit PHY.
1077 If your system has 10/100 PHY only, it might not occur
1078 wrong behavior. Because PHY usually return timeout or
1079 useless data when polling gigabit status and gigabit
1080 control registers. This behavior won't affect the
1081 correctnessof 10/100 link speed update.
1084 Support for SMSC's LAN911x and LAN921x chips
1087 Define this to hold the physical address
1088 of the device (I/O space)
1090 CONFIG_SMC911X_32_BIT
1091 Define this if data bus is 32 bits
1093 CONFIG_SMC911X_16_BIT
1094 Define this if data bus is 16 bits. If your processor
1095 automatically converts one 32 bit word to two 16 bit
1096 words you may also try CONFIG_SMC911X_32_BIT.
1099 Support for Renesas on-chip Ethernet controller
1101 CONFIG_SH_ETHER_USE_PORT
1102 Define the number of ports to be used
1104 CONFIG_SH_ETHER_PHY_ADDR
1105 Define the ETH PHY's address
1107 CONFIG_SH_ETHER_CACHE_WRITEBACK
1108 If this option is set, the driver enables cache flush.
1111 CONFIG_GENERIC_LPC_TPM
1112 Support for generic parallel port TPM devices. Only one device
1113 per system is supported at this time.
1115 CONFIG_TPM_TIS_BASE_ADDRESS
1116 Base address where the generic TPM device is mapped
1117 to. Contemporary x86 systems usually map it at
1121 At the moment only the UHCI host controller is
1122 supported (PIP405, MIP405, MPC5200); define
1123 CONFIG_USB_UHCI to enable it.
1124 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1125 and define CONFIG_USB_STORAGE to enable the USB
1128 Supported are USB Keyboards and USB Floppy drives
1130 MPC5200 USB requires additional defines:
1132 for 528 MHz Clock: 0x0001bbbb
1136 for differential drivers: 0x00001000
1137 for single ended drivers: 0x00005000
1138 for differential drivers on PSC3: 0x00000100
1139 for single ended drivers on PSC3: 0x00004100
1140 CONFIG_SYS_USB_EVENT_POLL
1141 May be defined to allow interrupt polling
1142 instead of using asynchronous interrupts
1144 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1145 txfilltuning field in the EHCI controller on reset.
1148 Define the below if you wish to use the USB console.
1149 Once firmware is rebuilt from a serial console issue the
1150 command "setenv stdin usbtty; setenv stdout usbtty" and
1151 attach your USB cable. The Unix command "dmesg" should print
1152 it has found a new device. The environment variable usbtty
1153 can be set to gserial or cdc_acm to enable your device to
1154 appear to a USB host as a Linux gserial device or a
1155 Common Device Class Abstract Control Model serial device.
1156 If you select usbtty = gserial you should be able to enumerate
1158 # modprobe usbserial vendor=0xVendorID product=0xProductID
1159 else if using cdc_acm, simply setting the environment
1160 variable usbtty to be cdc_acm should suffice. The following
1161 might be defined in YourBoardName.h
1164 Define this to build a UDC device
1167 Define this to have a tty type of device available to
1168 talk to the UDC device
1171 Define this to enable the high speed support for usb
1172 device and usbtty. If this feature is enabled, a routine
1173 int is_usbd_high_speed(void)
1174 also needs to be defined by the driver to dynamically poll
1175 whether the enumeration has succeded at high speed or full
1178 CONFIG_SYS_CONSOLE_IS_IN_ENV
1179 Define this if you want stdin, stdout &/or stderr to
1183 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1184 Derive USB clock from external clock "blah"
1185 - CONFIG_SYS_USB_EXTC_CLK 0x02
1187 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1188 Derive USB clock from brgclk
1189 - CONFIG_SYS_USB_BRG_CLK 0x04
1191 If you have a USB-IF assigned VendorID then you may wish to
1192 define your own vendor specific values either in BoardName.h
1193 or directly in usbd_vendor_info.h. If you don't define
1194 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1195 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1196 should pretend to be a Linux device to it's target host.
1198 CONFIG_USBD_MANUFACTURER
1199 Define this string as the name of your company for
1200 - CONFIG_USBD_MANUFACTURER "my company"
1202 CONFIG_USBD_PRODUCT_NAME
1203 Define this string as the name of your product
1204 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1206 CONFIG_USBD_VENDORID
1207 Define this as your assigned Vendor ID from the USB
1208 Implementors Forum. This *must* be a genuine Vendor ID
1209 to avoid polluting the USB namespace.
1210 - CONFIG_USBD_VENDORID 0xFFFF
1212 CONFIG_USBD_PRODUCTID
1213 Define this as the unique Product ID
1215 - CONFIG_USBD_PRODUCTID 0xFFFF
1217 - ULPI Layer Support:
1218 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1219 the generic ULPI layer. The generic layer accesses the ULPI PHY
1220 via the platform viewport, so you need both the genric layer and
1221 the viewport enabled. Currently only Chipidea/ARC based
1222 viewport is supported.
1223 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1224 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1227 The MMC controller on the Intel PXA is supported. To
1228 enable this define CONFIG_MMC. The MMC can be
1229 accessed from the boot prompt by mapping the device
1230 to physical memory similar to flash. Command line is
1231 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1232 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1235 Support for Renesas on-chip MMCIF controller
1237 CONFIG_SH_MMCIF_ADDR
1238 Define the base address of MMCIF registers
1241 Define the clock frequency for MMCIF
1243 - Journaling Flash filesystem support:
1244 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1245 CONFIG_JFFS2_NAND_DEV
1246 Define these for a default partition on a NAND device
1248 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1249 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1250 Define these for a default partition on a NOR device
1252 CONFIG_SYS_JFFS_CUSTOM_PART
1253 Define this to create an own partition. You have to provide a
1254 function struct part_info* jffs2_part_info(int part_num)
1256 If you define only one JFFS2 partition you may also want to
1257 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1258 to disable the command chpart. This is the default when you
1259 have not defined a custom partition
1261 - FAT(File Allocation Table) filesystem write function support:
1264 Define this to enable support for saving memory data as a
1265 file in FAT formatted partition.
1267 This will also enable the command "fatwrite" enabling the
1268 user to write files to FAT.
1273 Define this to enable standard (PC-Style) keyboard
1277 Standard PC keyboard driver with US (is default) and
1278 GERMAN key layout (switch via environment 'keymap=de') support.
1279 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1280 for cfb_console. Supports cursor blinking.
1285 Define this to enable video support (for output to
1288 CONFIG_VIDEO_CT69000
1290 Enable Chips & Technologies 69000 Video chip
1292 CONFIG_VIDEO_SMI_LYNXEM
1293 Enable Silicon Motion SMI 712/710/810 Video chip. The
1294 video output is selected via environment 'videoout'
1295 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1298 For the CT69000 and SMI_LYNXEM drivers, videomode is
1299 selected via environment 'videomode'. Two different ways
1301 - "videomode=num" 'num' is a standard LiLo mode numbers.
1302 Following standard modes are supported (* is default):
1304 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1305 -------------+---------------------------------------------
1306 8 bits | 0x301* 0x303 0x305 0x161 0x307
1307 15 bits | 0x310 0x313 0x316 0x162 0x319
1308 16 bits | 0x311 0x314 0x317 0x163 0x31A
1309 24 bits | 0x312 0x315 0x318 ? 0x31B
1310 -------------+---------------------------------------------
1311 (i.e. setenv videomode 317; saveenv; reset;)
1313 - "videomode=bootargs" all the video parameters are parsed
1314 from the bootargs. (See drivers/video/videomodes.c)
1317 CONFIG_VIDEO_SED13806
1318 Enable Epson SED13806 driver. This driver supports 8bpp
1319 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1320 or CONFIG_VIDEO_SED13806_16BPP
1323 Enable the Freescale DIU video driver. Reference boards for
1324 SOCs that have a DIU should define this macro to enable DIU
1325 support, and should also define these other macros:
1331 CONFIG_VIDEO_SW_CURSOR
1332 CONFIG_VGA_AS_SINGLE_DEVICE
1334 CONFIG_VIDEO_BMP_LOGO
1336 The DIU driver will look for the 'video-mode' environment
1337 variable, and if defined, enable the DIU as a console during
1338 boot. See the documentation file README.video for a
1339 description of this variable.
1344 Define this to enable a custom keyboard support.
1345 This simply calls drv_keyboard_init() which must be
1346 defined in your board-specific files.
1347 The only board using this so far is RBC823.
1349 - LCD Support: CONFIG_LCD
1351 Define this to enable LCD support (for output to LCD
1352 display); also select one of the supported displays
1353 by defining one of these:
1357 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1359 CONFIG_NEC_NL6448AC33:
1361 NEC NL6448AC33-18. Active, color, single scan.
1363 CONFIG_NEC_NL6448BC20
1365 NEC NL6448BC20-08. 6.5", 640x480.
1366 Active, color, single scan.
1368 CONFIG_NEC_NL6448BC33_54
1370 NEC NL6448BC33-54. 10.4", 640x480.
1371 Active, color, single scan.
1375 Sharp 320x240. Active, color, single scan.
1376 It isn't 16x9, and I am not sure what it is.
1378 CONFIG_SHARP_LQ64D341
1380 Sharp LQ64D341 display, 640x480.
1381 Active, color, single scan.
1385 HLD1045 display, 640x480.
1386 Active, color, single scan.
1390 Optrex CBL50840-2 NF-FW 99 22 M5
1392 Hitachi LMG6912RPFC-00T
1396 320x240. Black & white.
1398 Normally display is black on white background; define
1399 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1401 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1403 If this option is set, the environment is checked for
1404 a variable "splashimage". If found, the usual display
1405 of logo, copyright and system information on the LCD
1406 is suppressed and the BMP image at the address
1407 specified in "splashimage" is loaded instead. The
1408 console is redirected to the "nulldev", too. This
1409 allows for a "silent" boot where a splash screen is
1410 loaded very quickly after power-on.
1412 CONFIG_SPLASH_SCREEN_ALIGN
1414 If this option is set the splash image can be freely positioned
1415 on the screen. Environment variable "splashpos" specifies the
1416 position as "x,y". If a positive number is given it is used as
1417 number of pixel from left/top. If a negative number is given it
1418 is used as number of pixel from right/bottom. You can also
1419 specify 'm' for centering the image.
1422 setenv splashpos m,m
1423 => image at center of screen
1425 setenv splashpos 30,20
1426 => image at x = 30 and y = 20
1428 setenv splashpos -10,m
1429 => vertically centered image
1430 at x = dspWidth - bmpWidth - 9
1432 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1434 If this option is set, additionally to standard BMP
1435 images, gzipped BMP images can be displayed via the
1436 splashscreen support or the bmp command.
1438 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1440 If this option is set, 8-bit RLE compressed BMP images
1441 can be displayed via the splashscreen support or the
1444 - Compression support:
1447 If this option is set, support for bzip2 compressed
1448 images is included. If not, only uncompressed and gzip
1449 compressed images are supported.
1451 NOTE: the bzip2 algorithm requires a lot of RAM, so
1452 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1457 If this option is set, support for lzma compressed
1460 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1461 requires an amount of dynamic memory that is given by the
1464 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1466 Where lc and lp stand for, respectively, Literal context bits
1467 and Literal pos bits.
1469 This value is upper-bounded by 14MB in the worst case. Anyway,
1470 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1471 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1472 a very small buffer.
1474 Use the lzmainfo tool to determinate the lc and lp values and
1475 then calculate the amount of needed dynamic memory (ensuring
1476 the appropriate CONFIG_SYS_MALLOC_LEN value).
1481 The address of PHY on MII bus.
1483 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1485 The clock frequency of the MII bus
1489 If this option is set, support for speed/duplex
1490 detection of gigabit PHY is included.
1492 CONFIG_PHY_RESET_DELAY
1494 Some PHY like Intel LXT971A need extra delay after
1495 reset before any MII register access is possible.
1496 For such PHY, set this option to the usec delay
1497 required. (minimum 300usec for LXT971A)
1499 CONFIG_PHY_CMD_DELAY (ppc4xx)
1501 Some PHY like Intel LXT971A need extra delay after
1502 command issued before MII status register can be read
1512 Define a default value for Ethernet address to use
1513 for the respective Ethernet interface, in case this
1514 is not determined automatically.
1519 Define a default value for the IP address to use for
1520 the default Ethernet interface, in case this is not
1521 determined through e.g. bootp.
1522 (Environment variable "ipaddr")
1524 - Server IP address:
1527 Defines a default value for the IP address of a TFTP
1528 server to contact when using the "tftboot" command.
1529 (Environment variable "serverip")
1531 CONFIG_KEEP_SERVERADDR
1533 Keeps the server's MAC address, in the env 'serveraddr'
1534 for passing to bootargs (like Linux's netconsole option)
1536 - Gateway IP address:
1539 Defines a default value for the IP address of the
1540 default router where packets to other networks are
1542 (Environment variable "gatewayip")
1547 Defines a default value for the subnet mask (or
1548 routing prefix) which is used to determine if an IP
1549 address belongs to the local subnet or needs to be
1550 forwarded through a router.
1551 (Environment variable "netmask")
1553 - Multicast TFTP Mode:
1556 Defines whether you want to support multicast TFTP as per
1557 rfc-2090; for example to work with atftp. Lets lots of targets
1558 tftp down the same boot image concurrently. Note: the Ethernet
1559 driver in use must provide a function: mcast() to join/leave a
1562 - BOOTP Recovery Mode:
1563 CONFIG_BOOTP_RANDOM_DELAY
1565 If you have many targets in a network that try to
1566 boot using BOOTP, you may want to avoid that all
1567 systems send out BOOTP requests at precisely the same
1568 moment (which would happen for instance at recovery
1569 from a power failure, when all systems will try to
1570 boot, thus flooding the BOOTP server. Defining
1571 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1572 inserted before sending out BOOTP requests. The
1573 following delays are inserted then:
1575 1st BOOTP request: delay 0 ... 1 sec
1576 2nd BOOTP request: delay 0 ... 2 sec
1577 3rd BOOTP request: delay 0 ... 4 sec
1579 BOOTP requests: delay 0 ... 8 sec
1581 - DHCP Advanced Options:
1582 You can fine tune the DHCP functionality by defining
1583 CONFIG_BOOTP_* symbols:
1585 CONFIG_BOOTP_SUBNETMASK
1586 CONFIG_BOOTP_GATEWAY
1587 CONFIG_BOOTP_HOSTNAME
1588 CONFIG_BOOTP_NISDOMAIN
1589 CONFIG_BOOTP_BOOTPATH
1590 CONFIG_BOOTP_BOOTFILESIZE
1593 CONFIG_BOOTP_SEND_HOSTNAME
1594 CONFIG_BOOTP_NTPSERVER
1595 CONFIG_BOOTP_TIMEOFFSET
1596 CONFIG_BOOTP_VENDOREX
1597 CONFIG_BOOTP_MAY_FAIL
1599 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1600 environment variable, not the BOOTP server.
1602 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1603 after the configured retry count, the call will fail
1604 instead of starting over. This can be used to fail over
1605 to Link-local IP address configuration if the DHCP server
1608 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1609 serverip from a DHCP server, it is possible that more
1610 than one DNS serverip is offered to the client.
1611 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1612 serverip will be stored in the additional environment
1613 variable "dnsip2". The first DNS serverip is always
1614 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1617 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1618 to do a dynamic update of a DNS server. To do this, they
1619 need the hostname of the DHCP requester.
1620 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1621 of the "hostname" environment variable is passed as
1622 option 12 to the DHCP server.
1624 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1626 A 32bit value in microseconds for a delay between
1627 receiving a "DHCP Offer" and sending the "DHCP Request".
1628 This fixes a problem with certain DHCP servers that don't
1629 respond 100% of the time to a "DHCP request". E.g. On an
1630 AT91RM9200 processor running at 180MHz, this delay needed
1631 to be *at least* 15,000 usec before a Windows Server 2003
1632 DHCP server would reply 100% of the time. I recommend at
1633 least 50,000 usec to be safe. The alternative is to hope
1634 that one of the retries will be successful but note that
1635 the DHCP timeout and retry process takes a longer than
1638 - Link-local IP address negotiation:
1639 Negotiate with other link-local clients on the local network
1640 for an address that doesn't require explicit configuration.
1641 This is especially useful if a DHCP server cannot be guaranteed
1642 to exist in all environments that the device must operate.
1644 See doc/README.link-local for more information.
1647 CONFIG_CDP_DEVICE_ID
1649 The device id used in CDP trigger frames.
1651 CONFIG_CDP_DEVICE_ID_PREFIX
1653 A two character string which is prefixed to the MAC address
1658 A printf format string which contains the ascii name of
1659 the port. Normally is set to "eth%d" which sets
1660 eth0 for the first Ethernet, eth1 for the second etc.
1662 CONFIG_CDP_CAPABILITIES
1664 A 32bit integer which indicates the device capabilities;
1665 0x00000010 for a normal host which does not forwards.
1669 An ascii string containing the version of the software.
1673 An ascii string containing the name of the platform.
1677 A 32bit integer sent on the trigger.
1679 CONFIG_CDP_POWER_CONSUMPTION
1681 A 16bit integer containing the power consumption of the
1682 device in .1 of milliwatts.
1684 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1686 A byte containing the id of the VLAN.
1688 - Status LED: CONFIG_STATUS_LED
1690 Several configurations allow to display the current
1691 status using a LED. For instance, the LED will blink
1692 fast while running U-Boot code, stop blinking as
1693 soon as a reply to a BOOTP request was received, and
1694 start blinking slow once the Linux kernel is running
1695 (supported by a status LED driver in the Linux
1696 kernel). Defining CONFIG_STATUS_LED enables this
1699 - CAN Support: CONFIG_CAN_DRIVER
1701 Defining CONFIG_CAN_DRIVER enables CAN driver support
1702 on those systems that support this (optional)
1703 feature, like the TQM8xxL modules.
1705 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1707 These enable I2C serial bus commands. Defining either of
1708 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1709 include the appropriate I2C driver for the selected CPU.
1711 This will allow you to use i2c commands at the u-boot
1712 command line (as long as you set CONFIG_CMD_I2C in
1713 CONFIG_COMMANDS) and communicate with i2c based realtime
1714 clock chips. See common/cmd_i2c.c for a description of the
1715 command line interface.
1717 CONFIG_HARD_I2C selects a hardware I2C controller.
1719 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1720 bit-banging) driver instead of CPM or similar hardware
1723 There are several other quantities that must also be
1724 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1726 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1727 to be the frequency (in Hz) at which you wish your i2c bus
1728 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1729 the CPU's i2c node address).
1731 Now, the u-boot i2c code for the mpc8xx
1732 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1733 and so its address should therefore be cleared to 0 (See,
1734 eg, MPC823e User's Manual p.16-473). So, set
1735 CONFIG_SYS_I2C_SLAVE to 0.
1737 CONFIG_SYS_I2C_INIT_MPC5XXX
1739 When a board is reset during an i2c bus transfer
1740 chips might think that the current transfer is still
1741 in progress. Reset the slave devices by sending start
1742 commands until the slave device responds.
1744 That's all that's required for CONFIG_HARD_I2C.
1746 If you use the software i2c interface (CONFIG_SOFT_I2C)
1747 then the following macros need to be defined (examples are
1748 from include/configs/lwmon.h):
1752 (Optional). Any commands necessary to enable the I2C
1753 controller or configure ports.
1755 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1759 (Only for MPC8260 CPU). The I/O port to use (the code
1760 assumes both bits are on the same port). Valid values
1761 are 0..3 for ports A..D.
1765 The code necessary to make the I2C data line active
1766 (driven). If the data line is open collector, this
1769 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1773 The code necessary to make the I2C data line tri-stated
1774 (inactive). If the data line is open collector, this
1777 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1781 Code that returns TRUE if the I2C data line is high,
1784 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1788 If <bit> is TRUE, sets the I2C data line high. If it
1789 is FALSE, it clears it (low).
1791 eg: #define I2C_SDA(bit) \
1792 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1793 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1797 If <bit> is TRUE, sets the I2C clock line high. If it
1798 is FALSE, it clears it (low).
1800 eg: #define I2C_SCL(bit) \
1801 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1802 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1806 This delay is invoked four times per clock cycle so this
1807 controls the rate of data transfer. The data rate thus
1808 is 1 / (I2C_DELAY * 4). Often defined to be something
1811 #define I2C_DELAY udelay(2)
1813 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1815 If your arch supports the generic GPIO framework (asm/gpio.h),
1816 then you may alternatively define the two GPIOs that are to be
1817 used as SCL / SDA. Any of the previous I2C_xxx macros will
1818 have GPIO-based defaults assigned to them as appropriate.
1820 You should define these to the GPIO value as given directly to
1821 the generic GPIO functions.
1823 CONFIG_SYS_I2C_INIT_BOARD
1825 When a board is reset during an i2c bus transfer
1826 chips might think that the current transfer is still
1827 in progress. On some boards it is possible to access
1828 the i2c SCLK line directly, either by using the
1829 processor pin as a GPIO or by having a second pin
1830 connected to the bus. If this option is defined a
1831 custom i2c_init_board() routine in boards/xxx/board.c
1832 is run early in the boot sequence.
1834 CONFIG_SYS_I2C_BOARD_LATE_INIT
1836 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1837 defined a custom i2c_board_late_init() routine in
1838 boards/xxx/board.c is run AFTER the operations in i2c_init()
1839 is completed. This callpoint can be used to unreset i2c bus
1840 using CPU i2c controller register accesses for CPUs whose i2c
1841 controller provide such a method. It is called at the end of
1842 i2c_init() to allow i2c_init operations to setup the i2c bus
1843 controller on the CPU (e.g. setting bus speed & slave address).
1845 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1847 This option enables configuration of bi_iic_fast[] flags
1848 in u-boot bd_info structure based on u-boot environment
1849 variable "i2cfast". (see also i2cfast)
1851 CONFIG_I2C_MULTI_BUS
1853 This option allows the use of multiple I2C buses, each of which
1854 must have a controller. At any point in time, only one bus is
1855 active. To switch to a different bus, use the 'i2c dev' command.
1856 Note that bus numbering is zero-based.
1858 CONFIG_SYS_I2C_NOPROBES
1860 This option specifies a list of I2C devices that will be skipped
1861 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1862 is set, specify a list of bus-device pairs. Otherwise, specify
1863 a 1D array of device addresses
1866 #undef CONFIG_I2C_MULTI_BUS
1867 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1869 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1871 #define CONFIG_I2C_MULTI_BUS
1872 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1874 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1876 CONFIG_SYS_SPD_BUS_NUM
1878 If defined, then this indicates the I2C bus number for DDR SPD.
1879 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1881 CONFIG_SYS_RTC_BUS_NUM
1883 If defined, then this indicates the I2C bus number for the RTC.
1884 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1886 CONFIG_SYS_DTT_BUS_NUM
1888 If defined, then this indicates the I2C bus number for the DTT.
1889 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1891 CONFIG_SYS_I2C_DTT_ADDR:
1893 If defined, specifies the I2C address of the DTT device.
1894 If not defined, then U-Boot uses predefined value for
1895 specified DTT device.
1899 Define this option if you want to use Freescale's I2C driver in
1900 drivers/i2c/fsl_i2c.c.
1904 Define this option if you have I2C devices reached over 1 .. n
1905 I2C Muxes like the pca9544a. This option addes a new I2C
1906 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1907 new I2C Bus to the existing I2C Busses. If you select the
1908 new Bus with "i2c dev", u-bbot sends first the commandos for
1909 the muxes to activate this new "bus".
1911 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1915 Adding a new I2C Bus reached over 2 pca9544a muxes
1916 The First mux with address 70 and channel 6
1917 The Second mux with address 71 and channel 4
1919 => i2c bus pca9544a:70:6:pca9544a:71:4
1921 Use the "i2c bus" command without parameter, to get a list
1922 of I2C Busses with muxes:
1925 Busses reached over muxes:
1927 reached over Mux(es):
1930 reached over Mux(es):
1935 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1936 u-boot first sends the command to the mux@70 to enable
1937 channel 6, and then the command to the mux@71 to enable
1940 After that, you can use the "normal" i2c commands as
1941 usual to communicate with your I2C devices behind
1944 This option is actually implemented for the bitbanging
1945 algorithm in common/soft_i2c.c and for the Hardware I2C
1946 Bus on the MPC8260. But it should be not so difficult
1947 to add this option to other architectures.
1949 CONFIG_SOFT_I2C_READ_REPEATED_START
1951 defining this will force the i2c_read() function in
1952 the soft_i2c driver to perform an I2C repeated start
1953 between writing the address pointer and reading the
1954 data. If this define is omitted the default behaviour
1955 of doing a stop-start sequence will be used. Most I2C
1956 devices can use either method, but some require one or
1959 - SPI Support: CONFIG_SPI
1961 Enables SPI driver (so far only tested with
1962 SPI EEPROM, also an instance works with Crystal A/D and
1963 D/As on the SACSng board)
1967 Enables the driver for SPI controller on SuperH. Currently
1968 only SH7757 is supported.
1972 Enables extended (16-bit) SPI EEPROM addressing.
1973 (symmetrical to CONFIG_I2C_X)
1977 Enables a software (bit-bang) SPI driver rather than
1978 using hardware support. This is a general purpose
1979 driver that only requires three general I/O port pins
1980 (two outputs, one input) to function. If this is
1981 defined, the board configuration must define several
1982 SPI configuration items (port pins to use, etc). For
1983 an example, see include/configs/sacsng.h.
1987 Enables a hardware SPI driver for general-purpose reads
1988 and writes. As with CONFIG_SOFT_SPI, the board configuration
1989 must define a list of chip-select function pointers.
1990 Currently supported on some MPC8xxx processors. For an
1991 example, see include/configs/mpc8349emds.h.
1995 Enables the driver for the SPI controllers on i.MX and MXC
1996 SoCs. Currently i.MX31/35/51 are supported.
1998 - FPGA Support: CONFIG_FPGA
2000 Enables FPGA subsystem.
2002 CONFIG_FPGA_<vendor>
2004 Enables support for specific chip vendors.
2007 CONFIG_FPGA_<family>
2009 Enables support for FPGA family.
2010 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2014 Specify the number of FPGA devices to support.
2016 CONFIG_SYS_FPGA_PROG_FEEDBACK
2018 Enable printing of hash marks during FPGA configuration.
2020 CONFIG_SYS_FPGA_CHECK_BUSY
2022 Enable checks on FPGA configuration interface busy
2023 status by the configuration function. This option
2024 will require a board or device specific function to
2029 If defined, a function that provides delays in the FPGA
2030 configuration driver.
2032 CONFIG_SYS_FPGA_CHECK_CTRLC
2033 Allow Control-C to interrupt FPGA configuration
2035 CONFIG_SYS_FPGA_CHECK_ERROR
2037 Check for configuration errors during FPGA bitfile
2038 loading. For example, abort during Virtex II
2039 configuration if the INIT_B line goes low (which
2040 indicated a CRC error).
2042 CONFIG_SYS_FPGA_WAIT_INIT
2044 Maximum time to wait for the INIT_B line to deassert
2045 after PROB_B has been deasserted during a Virtex II
2046 FPGA configuration sequence. The default time is 500
2049 CONFIG_SYS_FPGA_WAIT_BUSY
2051 Maximum time to wait for BUSY to deassert during
2052 Virtex II FPGA configuration. The default is 5 ms.
2054 CONFIG_SYS_FPGA_WAIT_CONFIG
2056 Time to wait after FPGA configuration. The default is
2059 - Configuration Management:
2062 If defined, this string will be added to the U-Boot
2063 version information (U_BOOT_VERSION)
2065 - Vendor Parameter Protection:
2067 U-Boot considers the values of the environment
2068 variables "serial#" (Board Serial Number) and
2069 "ethaddr" (Ethernet Address) to be parameters that
2070 are set once by the board vendor / manufacturer, and
2071 protects these variables from casual modification by
2072 the user. Once set, these variables are read-only,
2073 and write or delete attempts are rejected. You can
2074 change this behaviour:
2076 If CONFIG_ENV_OVERWRITE is #defined in your config
2077 file, the write protection for vendor parameters is
2078 completely disabled. Anybody can change or delete
2081 Alternatively, if you #define _both_ CONFIG_ETHADDR
2082 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2083 Ethernet address is installed in the environment,
2084 which can be changed exactly ONCE by the user. [The
2085 serial# is unaffected by this, i. e. it remains
2091 Define this variable to enable the reservation of
2092 "protected RAM", i. e. RAM which is not overwritten
2093 by U-Boot. Define CONFIG_PRAM to hold the number of
2094 kB you want to reserve for pRAM. You can overwrite
2095 this default value by defining an environment
2096 variable "pram" to the number of kB you want to
2097 reserve. Note that the board info structure will
2098 still show the full amount of RAM. If pRAM is
2099 reserved, a new environment variable "mem" will
2100 automatically be defined to hold the amount of
2101 remaining RAM in a form that can be passed as boot
2102 argument to Linux, for instance like that:
2104 setenv bootargs ... mem=\${mem}
2107 This way you can tell Linux not to use this memory,
2108 either, which results in a memory region that will
2109 not be affected by reboots.
2111 *WARNING* If your board configuration uses automatic
2112 detection of the RAM size, you must make sure that
2113 this memory test is non-destructive. So far, the
2114 following board configurations are known to be
2117 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
2118 HERMES, IP860, RPXlite, LWMON, LANTEC,
2124 Define this variable to stop the system in case of a
2125 fatal error, so that you have to reset it manually.
2126 This is probably NOT a good idea for an embedded
2127 system where you want the system to reboot
2128 automatically as fast as possible, but it may be
2129 useful during development since you can try to debug
2130 the conditions that lead to the situation.
2132 CONFIG_NET_RETRY_COUNT
2134 This variable defines the number of retries for
2135 network operations like ARP, RARP, TFTP, or BOOTP
2136 before giving up the operation. If not defined, a
2137 default value of 5 is used.
2141 Timeout waiting for an ARP reply in milliseconds.
2143 - Command Interpreter:
2144 CONFIG_AUTO_COMPLETE
2146 Enable auto completion of commands using TAB.
2148 Note that this feature has NOT been implemented yet
2149 for the "hush" shell.
2152 CONFIG_SYS_HUSH_PARSER
2154 Define this variable to enable the "hush" shell (from
2155 Busybox) as command line interpreter, thus enabling
2156 powerful command line syntax like
2157 if...then...else...fi conditionals or `&&' and '||'
2158 constructs ("shell scripts").
2160 If undefined, you get the old, much simpler behaviour
2161 with a somewhat smaller memory footprint.
2164 CONFIG_SYS_PROMPT_HUSH_PS2
2166 This defines the secondary prompt string, which is
2167 printed when the command interpreter needs more input
2168 to complete a command. Usually "> ".
2172 In the current implementation, the local variables
2173 space and global environment variables space are
2174 separated. Local variables are those you define by
2175 simply typing `name=value'. To access a local
2176 variable later on, you have write `$name' or
2177 `${name}'; to execute the contents of a variable
2178 directly type `$name' at the command prompt.
2180 Global environment variables are those you use
2181 setenv/printenv to work with. To run a command stored
2182 in such a variable, you need to use the run command,
2183 and you must not use the '$' sign to access them.
2185 To store commands and special characters in a
2186 variable, please use double quotation marks
2187 surrounding the whole text of the variable, instead
2188 of the backslashes before semicolons and special
2191 - Commandline Editing and History:
2192 CONFIG_CMDLINE_EDITING
2194 Enable editing and History functions for interactive
2195 commandline input operations
2197 - Default Environment:
2198 CONFIG_EXTRA_ENV_SETTINGS
2200 Define this to contain any number of null terminated
2201 strings (variable = value pairs) that will be part of
2202 the default environment compiled into the boot image.
2204 For example, place something like this in your
2205 board's config file:
2207 #define CONFIG_EXTRA_ENV_SETTINGS \
2211 Warning: This method is based on knowledge about the
2212 internal format how the environment is stored by the
2213 U-Boot code. This is NOT an official, exported
2214 interface! Although it is unlikely that this format
2215 will change soon, there is no guarantee either.
2216 You better know what you are doing here.
2218 Note: overly (ab)use of the default environment is
2219 discouraged. Make sure to check other ways to preset
2220 the environment like the "source" command or the
2223 - DataFlash Support:
2224 CONFIG_HAS_DATAFLASH
2226 Defining this option enables DataFlash features and
2227 allows to read/write in Dataflash via the standard
2230 - Serial Flash support
2233 Defining this option enables SPI flash commands
2234 'sf probe/read/write/erase/update'.
2236 Usage requires an initial 'probe' to define the serial
2237 flash parameters, followed by read/write/erase/update
2240 The following defaults may be provided by the platform
2241 to handle the common case when only a single serial
2242 flash is present on the system.
2244 CONFIG_SF_DEFAULT_BUS Bus identifier
2245 CONFIG_SF_DEFAULT_CS Chip-select
2246 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2247 CONFIG_SF_DEFAULT_SPEED in Hz
2249 - SystemACE Support:
2252 Adding this option adds support for Xilinx SystemACE
2253 chips attached via some sort of local bus. The address
2254 of the chip must also be defined in the
2255 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2257 #define CONFIG_SYSTEMACE
2258 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2260 When SystemACE support is added, the "ace" device type
2261 becomes available to the fat commands, i.e. fatls.
2263 - TFTP Fixed UDP Port:
2266 If this is defined, the environment variable tftpsrcp
2267 is used to supply the TFTP UDP source port value.
2268 If tftpsrcp isn't defined, the normal pseudo-random port
2269 number generator is used.
2271 Also, the environment variable tftpdstp is used to supply
2272 the TFTP UDP destination port value. If tftpdstp isn't
2273 defined, the normal port 69 is used.
2275 The purpose for tftpsrcp is to allow a TFTP server to
2276 blindly start the TFTP transfer using the pre-configured
2277 target IP address and UDP port. This has the effect of
2278 "punching through" the (Windows XP) firewall, allowing
2279 the remainder of the TFTP transfer to proceed normally.
2280 A better solution is to properly configure the firewall,
2281 but sometimes that is not allowed.
2283 - Show boot progress:
2284 CONFIG_SHOW_BOOT_PROGRESS
2286 Defining this option allows to add some board-
2287 specific code (calling a user-provided function
2288 "show_boot_progress(int)") that enables you to show
2289 the system's boot progress on some display (for
2290 example, some LED's) on your board. At the moment,
2291 the following checkpoints are implemented:
2293 - Detailed boot stage timing
2295 Define this option to get detailed timing of each stage
2296 of the boot process.
2298 CONFIG_BOOTSTAGE_USER_COUNT
2299 This is the number of available user bootstage records.
2300 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2301 a new ID will be allocated from this stash. If you exceed
2302 the limit, recording will stop.
2304 CONFIG_BOOTSTAGE_REPORT
2305 Define this to print a report before boot, similar to this:
2307 Timer summary in microseconds:
2310 3,575,678 3,575,678 board_init_f start
2311 3,575,695 17 arch_cpu_init A9
2312 3,575,777 82 arch_cpu_init done
2313 3,659,598 83,821 board_init_r start
2314 3,910,375 250,777 main_loop
2315 29,916,167 26,005,792 bootm_start
2316 30,361,327 445,160 start_kernel
2318 Legacy uImage format:
2321 1 common/cmd_bootm.c before attempting to boot an image
2322 -1 common/cmd_bootm.c Image header has bad magic number
2323 2 common/cmd_bootm.c Image header has correct magic number
2324 -2 common/cmd_bootm.c Image header has bad checksum
2325 3 common/cmd_bootm.c Image header has correct checksum
2326 -3 common/cmd_bootm.c Image data has bad checksum
2327 4 common/cmd_bootm.c Image data has correct checksum
2328 -4 common/cmd_bootm.c Image is for unsupported architecture
2329 5 common/cmd_bootm.c Architecture check OK
2330 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2331 6 common/cmd_bootm.c Image Type check OK
2332 -6 common/cmd_bootm.c gunzip uncompression error
2333 -7 common/cmd_bootm.c Unimplemented compression type
2334 7 common/cmd_bootm.c Uncompression OK
2335 8 common/cmd_bootm.c No uncompress/copy overwrite error
2336 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2338 9 common/image.c Start initial ramdisk verification
2339 -10 common/image.c Ramdisk header has bad magic number
2340 -11 common/image.c Ramdisk header has bad checksum
2341 10 common/image.c Ramdisk header is OK
2342 -12 common/image.c Ramdisk data has bad checksum
2343 11 common/image.c Ramdisk data has correct checksum
2344 12 common/image.c Ramdisk verification complete, start loading
2345 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2346 13 common/image.c Start multifile image verification
2347 14 common/image.c No initial ramdisk, no multifile, continue.
2349 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2351 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2352 -31 post/post.c POST test failed, detected by post_output_backlog()
2353 -32 post/post.c POST test failed, detected by post_run_single()
2355 34 common/cmd_doc.c before loading a Image from a DOC device
2356 -35 common/cmd_doc.c Bad usage of "doc" command
2357 35 common/cmd_doc.c correct usage of "doc" command
2358 -36 common/cmd_doc.c No boot device
2359 36 common/cmd_doc.c correct boot device
2360 -37 common/cmd_doc.c Unknown Chip ID on boot device
2361 37 common/cmd_doc.c correct chip ID found, device available
2362 -38 common/cmd_doc.c Read Error on boot device
2363 38 common/cmd_doc.c reading Image header from DOC device OK
2364 -39 common/cmd_doc.c Image header has bad magic number
2365 39 common/cmd_doc.c Image header has correct magic number
2366 -40 common/cmd_doc.c Error reading Image from DOC device
2367 40 common/cmd_doc.c Image header has correct magic number
2368 41 common/cmd_ide.c before loading a Image from a IDE device
2369 -42 common/cmd_ide.c Bad usage of "ide" command
2370 42 common/cmd_ide.c correct usage of "ide" command
2371 -43 common/cmd_ide.c No boot device
2372 43 common/cmd_ide.c boot device found
2373 -44 common/cmd_ide.c Device not available
2374 44 common/cmd_ide.c Device available
2375 -45 common/cmd_ide.c wrong partition selected
2376 45 common/cmd_ide.c partition selected
2377 -46 common/cmd_ide.c Unknown partition table
2378 46 common/cmd_ide.c valid partition table found
2379 -47 common/cmd_ide.c Invalid partition type
2380 47 common/cmd_ide.c correct partition type
2381 -48 common/cmd_ide.c Error reading Image Header on boot device
2382 48 common/cmd_ide.c reading Image Header from IDE device OK
2383 -49 common/cmd_ide.c Image header has bad magic number
2384 49 common/cmd_ide.c Image header has correct magic number
2385 -50 common/cmd_ide.c Image header has bad checksum
2386 50 common/cmd_ide.c Image header has correct checksum
2387 -51 common/cmd_ide.c Error reading Image from IDE device
2388 51 common/cmd_ide.c reading Image from IDE device OK
2389 52 common/cmd_nand.c before loading a Image from a NAND device
2390 -53 common/cmd_nand.c Bad usage of "nand" command
2391 53 common/cmd_nand.c correct usage of "nand" command
2392 -54 common/cmd_nand.c No boot device
2393 54 common/cmd_nand.c boot device found
2394 -55 common/cmd_nand.c Unknown Chip ID on boot device
2395 55 common/cmd_nand.c correct chip ID found, device available
2396 -56 common/cmd_nand.c Error reading Image Header on boot device
2397 56 common/cmd_nand.c reading Image Header from NAND device OK
2398 -57 common/cmd_nand.c Image header has bad magic number
2399 57 common/cmd_nand.c Image header has correct magic number
2400 -58 common/cmd_nand.c Error reading Image from NAND device
2401 58 common/cmd_nand.c reading Image from NAND device OK
2403 -60 common/env_common.c Environment has a bad CRC, using default
2405 64 net/eth.c starting with Ethernet configuration.
2406 -64 net/eth.c no Ethernet found.
2407 65 net/eth.c Ethernet found.
2409 -80 common/cmd_net.c usage wrong
2410 80 common/cmd_net.c before calling NetLoop()
2411 -81 common/cmd_net.c some error in NetLoop() occurred
2412 81 common/cmd_net.c NetLoop() back without error
2413 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2414 82 common/cmd_net.c trying automatic boot
2415 83 common/cmd_net.c running "source" command
2416 -83 common/cmd_net.c some error in automatic boot or "source" command
2417 84 common/cmd_net.c end without errors
2422 100 common/cmd_bootm.c Kernel FIT Image has correct format
2423 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2424 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2425 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2426 102 common/cmd_bootm.c Kernel unit name specified
2427 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2428 103 common/cmd_bootm.c Found configuration node
2429 104 common/cmd_bootm.c Got kernel subimage node offset
2430 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2431 105 common/cmd_bootm.c Kernel subimage hash verification OK
2432 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2433 106 common/cmd_bootm.c Architecture check OK
2434 -106 common/cmd_bootm.c Kernel subimage has wrong type
2435 107 common/cmd_bootm.c Kernel subimage type OK
2436 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2437 108 common/cmd_bootm.c Got kernel subimage data/size
2438 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2439 -109 common/cmd_bootm.c Can't get kernel subimage type
2440 -110 common/cmd_bootm.c Can't get kernel subimage comp
2441 -111 common/cmd_bootm.c Can't get kernel subimage os
2442 -112 common/cmd_bootm.c Can't get kernel subimage load address
2443 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2445 120 common/image.c Start initial ramdisk verification
2446 -120 common/image.c Ramdisk FIT image has incorrect format
2447 121 common/image.c Ramdisk FIT image has correct format
2448 122 common/image.c No ramdisk subimage unit name, using configuration
2449 -122 common/image.c Can't get configuration for ramdisk subimage
2450 123 common/image.c Ramdisk unit name specified
2451 -124 common/image.c Can't get ramdisk subimage node offset
2452 125 common/image.c Got ramdisk subimage node offset
2453 -125 common/image.c Ramdisk subimage hash verification failed
2454 126 common/image.c Ramdisk subimage hash verification OK
2455 -126 common/image.c Ramdisk subimage for unsupported architecture
2456 127 common/image.c Architecture check OK
2457 -127 common/image.c Can't get ramdisk subimage data/size
2458 128 common/image.c Got ramdisk subimage data/size
2459 129 common/image.c Can't get ramdisk load address
2460 -129 common/image.c Got ramdisk load address
2462 -130 common/cmd_doc.c Incorrect FIT image format
2463 131 common/cmd_doc.c FIT image format OK
2465 -140 common/cmd_ide.c Incorrect FIT image format
2466 141 common/cmd_ide.c FIT image format OK
2468 -150 common/cmd_nand.c Incorrect FIT image format
2469 151 common/cmd_nand.c FIT image format OK
2471 - Standalone program support:
2472 CONFIG_STANDALONE_LOAD_ADDR
2474 This option defines a board specific value for the
2475 address where standalone program gets loaded, thus
2476 overwriting the architecture dependent default
2479 - Frame Buffer Address:
2482 Define CONFIG_FB_ADDR if you want to use specific
2483 address for frame buffer.
2484 Then system will reserve the frame buffer address to
2485 defined address instead of lcd_setmem (this function
2486 grabs the memory for frame buffer by panel's size).
2488 Please see board_init_f function.
2490 - Automatic software updates via TFTP server
2492 CONFIG_UPDATE_TFTP_CNT_MAX
2493 CONFIG_UPDATE_TFTP_MSEC_MAX
2495 These options enable and control the auto-update feature;
2496 for a more detailed description refer to doc/README.update.
2498 - MTD Support (mtdparts command, UBI support)
2501 Adds the MTD device infrastructure from the Linux kernel.
2502 Needed for mtdparts command support.
2504 CONFIG_MTD_PARTITIONS
2506 Adds the MTD partitioning infrastructure from the Linux
2507 kernel. Needed for UBI support.
2511 Enable building of SPL globally.
2514 LDSCRIPT for linking the SPL binary.
2517 Maximum binary size (text, data and rodata) of the SPL binary.
2519 CONFIG_SPL_TEXT_BASE
2520 TEXT_BASE for linking the SPL binary.
2522 CONFIG_SPL_BSS_START_ADDR
2523 Link address for the BSS within the SPL binary.
2525 CONFIG_SPL_BSS_MAX_SIZE
2526 Maximum binary size of the BSS section of the SPL binary.
2529 Adress of the start of the stack SPL will use
2531 CONFIG_SYS_SPL_MALLOC_START
2532 Starting address of the malloc pool used in SPL.
2534 CONFIG_SYS_SPL_MALLOC_SIZE
2535 The size of the malloc pool used in SPL.
2537 CONFIG_SPL_LIBCOMMON_SUPPORT
2538 Support for common/libcommon.o in SPL binary
2540 CONFIG_SPL_LIBDISK_SUPPORT
2541 Support for disk/libdisk.o in SPL binary
2543 CONFIG_SPL_I2C_SUPPORT
2544 Support for drivers/i2c/libi2c.o in SPL binary
2546 CONFIG_SPL_GPIO_SUPPORT
2547 Support for drivers/gpio/libgpio.o in SPL binary
2549 CONFIG_SPL_MMC_SUPPORT
2550 Support for drivers/mmc/libmmc.o in SPL binary
2552 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2553 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2554 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2555 Address, size and partition on the MMC to load U-Boot from
2556 when the MMC is being used in raw mode.
2558 CONFIG_SPL_FAT_SUPPORT
2559 Support for fs/fat/libfat.o in SPL binary
2561 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2562 Filename to read to load U-Boot when reading from FAT
2564 CONFIG_SPL_NAND_SIMPLE
2565 Support for drivers/mtd/nand/libnand.o in SPL binary
2567 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2568 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2569 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2570 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2571 CONFIG_SYS_NAND_ECCBYTES
2572 Defines the size and behavior of the NAND that SPL uses
2573 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2575 CONFIG_SYS_NAND_U_BOOT_OFFS
2576 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2579 CONFIG_SYS_NAND_U_BOOT_START
2580 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2583 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2584 Define this if you need to first read the OOB and then the
2585 data. This is used for example on davinci plattforms.
2587 CONFIG_SPL_OMAP3_ID_NAND
2588 Support for an OMAP3-specific set of functions to return the
2589 ID and MFR of the first attached NAND chip, if present.
2591 CONFIG_SPL_SERIAL_SUPPORT
2592 Support for drivers/serial/libserial.o in SPL binary
2594 CONFIG_SPL_SPI_FLASH_SUPPORT
2595 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2597 CONFIG_SPL_SPI_SUPPORT
2598 Support for drivers/spi/libspi.o in SPL binary
2600 CONFIG_SPL_LIBGENERIC_SUPPORT
2601 Support for lib/libgeneric.o in SPL binary
2606 [so far only for SMDK2400 boards]
2608 - Modem support enable:
2609 CONFIG_MODEM_SUPPORT
2611 - RTS/CTS Flow control enable:
2614 - Modem debug support:
2615 CONFIG_MODEM_SUPPORT_DEBUG
2617 Enables debugging stuff (char screen[1024], dbg())
2618 for modem support. Useful only with BDI2000.
2620 - Interrupt support (PPC):
2622 There are common interrupt_init() and timer_interrupt()
2623 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2624 for CPU specific initialization. interrupt_init_cpu()
2625 should set decrementer_count to appropriate value. If
2626 CPU resets decrementer automatically after interrupt
2627 (ppc4xx) it should set decrementer_count to zero.
2628 timer_interrupt() calls timer_interrupt_cpu() for CPU
2629 specific handling. If board has watchdog / status_led
2630 / other_activity_monitor it works automatically from
2631 general timer_interrupt().
2635 In the target system modem support is enabled when a
2636 specific key (key combination) is pressed during
2637 power-on. Otherwise U-Boot will boot normally
2638 (autoboot). The key_pressed() function is called from
2639 board_init(). Currently key_pressed() is a dummy
2640 function, returning 1 and thus enabling modem
2643 If there are no modem init strings in the
2644 environment, U-Boot proceed to autoboot; the
2645 previous output (banner, info printfs) will be
2648 See also: doc/README.Modem
2650 Board initialization settings:
2651 ------------------------------
2653 During Initialization u-boot calls a number of board specific functions
2654 to allow the preparation of board specific prerequisites, e.g. pin setup
2655 before drivers are initialized. To enable these callbacks the
2656 following configuration macros have to be defined. Currently this is
2657 architecture specific, so please check arch/your_architecture/lib/board.c
2658 typically in board_init_f() and board_init_r().
2660 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2661 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2662 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2663 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2665 Configuration Settings:
2666 -----------------------
2668 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2669 undefine this when you're short of memory.
2671 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2672 width of the commands listed in the 'help' command output.
2674 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2675 prompt for user input.
2677 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2679 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2681 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2683 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2684 the application (usually a Linux kernel) when it is
2687 - CONFIG_SYS_BAUDRATE_TABLE:
2688 List of legal baudrate settings for this board.
2690 - CONFIG_SYS_CONSOLE_INFO_QUIET
2691 Suppress display of console information at boot.
2693 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2694 If the board specific function
2695 extern int overwrite_console (void);
2696 returns 1, the stdin, stderr and stdout are switched to the
2697 serial port, else the settings in the environment are used.
2699 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2700 Enable the call to overwrite_console().
2702 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2703 Enable overwrite of previous console environment settings.
2705 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2706 Begin and End addresses of the area used by the
2709 - CONFIG_SYS_ALT_MEMTEST:
2710 Enable an alternate, more extensive memory test.
2712 - CONFIG_SYS_MEMTEST_SCRATCH:
2713 Scratch address used by the alternate memory test
2714 You only need to set this if address zero isn't writeable
2716 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2717 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2718 this specified memory area will get subtracted from the top
2719 (end) of RAM and won't get "touched" at all by U-Boot. By
2720 fixing up gd->ram_size the Linux kernel should gets passed
2721 the now "corrected" memory size and won't touch it either.
2722 This should work for arch/ppc and arch/powerpc. Only Linux
2723 board ports in arch/powerpc with bootwrapper support that
2724 recalculate the memory size from the SDRAM controller setup
2725 will have to get fixed in Linux additionally.
2727 This option can be used as a workaround for the 440EPx/GRx
2728 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2731 WARNING: Please make sure that this value is a multiple of
2732 the Linux page size (normally 4k). If this is not the case,
2733 then the end address of the Linux memory will be located at a
2734 non page size aligned address and this could cause major
2737 - CONFIG_SYS_TFTP_LOADADDR:
2738 Default load address for network file downloads
2740 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2741 Enable temporary baudrate change while serial download
2743 - CONFIG_SYS_SDRAM_BASE:
2744 Physical start address of SDRAM. _Must_ be 0 here.
2746 - CONFIG_SYS_MBIO_BASE:
2747 Physical start address of Motherboard I/O (if using a
2750 - CONFIG_SYS_FLASH_BASE:
2751 Physical start address of Flash memory.
2753 - CONFIG_SYS_MONITOR_BASE:
2754 Physical start address of boot monitor code (set by
2755 make config files to be same as the text base address
2756 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2757 CONFIG_SYS_FLASH_BASE when booting from flash.
2759 - CONFIG_SYS_MONITOR_LEN:
2760 Size of memory reserved for monitor code, used to
2761 determine _at_compile_time_ (!) if the environment is
2762 embedded within the U-Boot image, or in a separate
2765 - CONFIG_SYS_MALLOC_LEN:
2766 Size of DRAM reserved for malloc() use.
2768 - CONFIG_SYS_BOOTM_LEN:
2769 Normally compressed uImages are limited to an
2770 uncompressed size of 8 MBytes. If this is not enough,
2771 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2772 to adjust this setting to your needs.
2774 - CONFIG_SYS_BOOTMAPSZ:
2775 Maximum size of memory mapped by the startup code of
2776 the Linux kernel; all data that must be processed by
2777 the Linux kernel (bd_info, boot arguments, FDT blob if
2778 used) must be put below this limit, unless "bootm_low"
2779 enviroment variable is defined and non-zero. In such case
2780 all data for the Linux kernel must be between "bootm_low"
2781 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2782 variable "bootm_mapsize" will override the value of
2783 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2784 then the value in "bootm_size" will be used instead.
2786 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2787 Enable initrd_high functionality. If defined then the
2788 initrd_high feature is enabled and the bootm ramdisk subcommand
2791 - CONFIG_SYS_BOOT_GET_CMDLINE:
2792 Enables allocating and saving kernel cmdline in space between
2793 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2795 - CONFIG_SYS_BOOT_GET_KBD:
2796 Enables allocating and saving a kernel copy of the bd_info in
2797 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2799 - CONFIG_SYS_MAX_FLASH_BANKS:
2800 Max number of Flash memory banks
2802 - CONFIG_SYS_MAX_FLASH_SECT:
2803 Max number of sectors on a Flash chip
2805 - CONFIG_SYS_FLASH_ERASE_TOUT:
2806 Timeout for Flash erase operations (in ms)
2808 - CONFIG_SYS_FLASH_WRITE_TOUT:
2809 Timeout for Flash write operations (in ms)
2811 - CONFIG_SYS_FLASH_LOCK_TOUT
2812 Timeout for Flash set sector lock bit operation (in ms)
2814 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2815 Timeout for Flash clear lock bits operation (in ms)
2817 - CONFIG_SYS_FLASH_PROTECTION
2818 If defined, hardware flash sectors protection is used
2819 instead of U-Boot software protection.
2821 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2823 Enable TFTP transfers directly to flash memory;
2824 without this option such a download has to be
2825 performed in two steps: (1) download to RAM, and (2)
2826 copy from RAM to flash.
2828 The two-step approach is usually more reliable, since
2829 you can check if the download worked before you erase
2830 the flash, but in some situations (when system RAM is
2831 too limited to allow for a temporary copy of the
2832 downloaded image) this option may be very useful.
2834 - CONFIG_SYS_FLASH_CFI:
2835 Define if the flash driver uses extra elements in the
2836 common flash structure for storing flash geometry.
2838 - CONFIG_FLASH_CFI_DRIVER
2839 This option also enables the building of the cfi_flash driver
2840 in the drivers directory
2842 - CONFIG_FLASH_CFI_MTD
2843 This option enables the building of the cfi_mtd driver
2844 in the drivers directory. The driver exports CFI flash
2847 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2848 Use buffered writes to flash.
2850 - CONFIG_FLASH_SPANSION_S29WS_N
2851 s29ws-n MirrorBit flash has non-standard addresses for buffered
2854 - CONFIG_SYS_FLASH_QUIET_TEST
2855 If this option is defined, the common CFI flash doesn't
2856 print it's warning upon not recognized FLASH banks. This
2857 is useful, if some of the configured banks are only
2858 optionally available.
2860 - CONFIG_FLASH_SHOW_PROGRESS
2861 If defined (must be an integer), print out countdown
2862 digits and dots. Recommended value: 45 (9..1) for 80
2863 column displays, 15 (3..1) for 40 column displays.
2865 - CONFIG_SYS_RX_ETH_BUFFER:
2866 Defines the number of Ethernet receive buffers. On some
2867 Ethernet controllers it is recommended to set this value
2868 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2869 buffers can be full shortly after enabling the interface
2870 on high Ethernet traffic.
2871 Defaults to 4 if not defined.
2873 - CONFIG_ENV_MAX_ENTRIES
2875 Maximum number of entries in the hash table that is used
2876 internally to store the environment settings. The default
2877 setting is supposed to be generous and should work in most
2878 cases. This setting can be used to tune behaviour; see
2879 lib/hashtable.c for details.
2881 The following definitions that deal with the placement and management
2882 of environment data (variable area); in general, we support the
2883 following configurations:
2885 - CONFIG_BUILD_ENVCRC:
2887 Builds up envcrc with the target environment so that external utils
2888 may easily extract it and embed it in final U-Boot images.
2890 - CONFIG_ENV_IS_IN_FLASH:
2892 Define this if the environment is in flash memory.
2894 a) The environment occupies one whole flash sector, which is
2895 "embedded" in the text segment with the U-Boot code. This
2896 happens usually with "bottom boot sector" or "top boot
2897 sector" type flash chips, which have several smaller
2898 sectors at the start or the end. For instance, such a
2899 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2900 such a case you would place the environment in one of the
2901 4 kB sectors - with U-Boot code before and after it. With
2902 "top boot sector" type flash chips, you would put the
2903 environment in one of the last sectors, leaving a gap
2904 between U-Boot and the environment.
2906 - CONFIG_ENV_OFFSET:
2908 Offset of environment data (variable area) to the
2909 beginning of flash memory; for instance, with bottom boot
2910 type flash chips the second sector can be used: the offset
2911 for this sector is given here.
2913 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2917 This is just another way to specify the start address of
2918 the flash sector containing the environment (instead of
2921 - CONFIG_ENV_SECT_SIZE:
2923 Size of the sector containing the environment.
2926 b) Sometimes flash chips have few, equal sized, BIG sectors.
2927 In such a case you don't want to spend a whole sector for
2932 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2933 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2934 of this flash sector for the environment. This saves
2935 memory for the RAM copy of the environment.
2937 It may also save flash memory if you decide to use this
2938 when your environment is "embedded" within U-Boot code,
2939 since then the remainder of the flash sector could be used
2940 for U-Boot code. It should be pointed out that this is
2941 STRONGLY DISCOURAGED from a robustness point of view:
2942 updating the environment in flash makes it always
2943 necessary to erase the WHOLE sector. If something goes
2944 wrong before the contents has been restored from a copy in
2945 RAM, your target system will be dead.
2947 - CONFIG_ENV_ADDR_REDUND
2948 CONFIG_ENV_SIZE_REDUND
2950 These settings describe a second storage area used to hold
2951 a redundant copy of the environment data, so that there is
2952 a valid backup copy in case there is a power failure during
2953 a "saveenv" operation.
2955 BE CAREFUL! Any changes to the flash layout, and some changes to the
2956 source code will make it necessary to adapt <board>/u-boot.lds*
2960 - CONFIG_ENV_IS_IN_NVRAM:
2962 Define this if you have some non-volatile memory device
2963 (NVRAM, battery buffered SRAM) which you want to use for the
2969 These two #defines are used to determine the memory area you
2970 want to use for environment. It is assumed that this memory
2971 can just be read and written to, without any special
2974 BE CAREFUL! The first access to the environment happens quite early
2975 in U-Boot initalization (when we try to get the setting of for the
2976 console baudrate). You *MUST* have mapped your NVRAM area then, or
2979 Please note that even with NVRAM we still use a copy of the
2980 environment in RAM: we could work on NVRAM directly, but we want to
2981 keep settings there always unmodified except somebody uses "saveenv"
2982 to save the current settings.
2985 - CONFIG_ENV_IS_IN_EEPROM:
2987 Use this if you have an EEPROM or similar serial access
2988 device and a driver for it.
2990 - CONFIG_ENV_OFFSET:
2993 These two #defines specify the offset and size of the
2994 environment area within the total memory of your EEPROM.
2996 - CONFIG_SYS_I2C_EEPROM_ADDR:
2997 If defined, specified the chip address of the EEPROM device.
2998 The default address is zero.
3000 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3001 If defined, the number of bits used to address bytes in a
3002 single page in the EEPROM device. A 64 byte page, for example
3003 would require six bits.
3005 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3006 If defined, the number of milliseconds to delay between
3007 page writes. The default is zero milliseconds.
3009 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3010 The length in bytes of the EEPROM memory array address. Note
3011 that this is NOT the chip address length!
3013 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3014 EEPROM chips that implement "address overflow" are ones
3015 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3016 address and the extra bits end up in the "chip address" bit
3017 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3020 Note that we consider the length of the address field to
3021 still be one byte because the extra address bits are hidden
3022 in the chip address.
3024 - CONFIG_SYS_EEPROM_SIZE:
3025 The size in bytes of the EEPROM device.
3027 - CONFIG_ENV_EEPROM_IS_ON_I2C
3028 define this, if you have I2C and SPI activated, and your
3029 EEPROM, which holds the environment, is on the I2C bus.
3031 - CONFIG_I2C_ENV_EEPROM_BUS
3032 if you have an Environment on an EEPROM reached over
3033 I2C muxes, you can define here, how to reach this
3034 EEPROM. For example:
3036 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3038 EEPROM which holds the environment, is reached over
3039 a pca9547 i2c mux with address 0x70, channel 3.
3041 - CONFIG_ENV_IS_IN_DATAFLASH:
3043 Define this if you have a DataFlash memory device which you
3044 want to use for the environment.
3046 - CONFIG_ENV_OFFSET:
3050 These three #defines specify the offset and size of the
3051 environment area within the total memory of your DataFlash placed
3052 at the specified address.
3054 - CONFIG_ENV_IS_IN_REMOTE:
3056 Define this if you have a remote memory space which you
3057 want to use for the local device's environment.
3062 These two #defines specify the address and size of the
3063 environment area within the remote memory space. The
3064 local device can get the environment from remote memory
3065 space by SRIO or other links.
3067 BE CAREFUL! For some special cases, the local device can not use
3068 "saveenv" command. For example, the local device will get the
3069 environment stored in a remote NOR flash by SRIO link, but it can
3070 not erase, write this NOR flash by SRIO interface.
3072 - CONFIG_ENV_IS_IN_NAND:
3074 Define this if you have a NAND device which you want to use
3075 for the environment.
3077 - CONFIG_ENV_OFFSET:
3080 These two #defines specify the offset and size of the environment
3081 area within the first NAND device. CONFIG_ENV_OFFSET must be
3082 aligned to an erase block boundary.
3084 - CONFIG_ENV_OFFSET_REDUND (optional):
3086 This setting describes a second storage area of CONFIG_ENV_SIZE
3087 size used to hold a redundant copy of the environment data, so
3088 that there is a valid backup copy in case there is a power failure
3089 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3090 aligned to an erase block boundary.
3092 - CONFIG_ENV_RANGE (optional):
3094 Specifies the length of the region in which the environment
3095 can be written. This should be a multiple of the NAND device's
3096 block size. Specifying a range with more erase blocks than
3097 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3098 the range to be avoided.
3100 - CONFIG_ENV_OFFSET_OOB (optional):
3102 Enables support for dynamically retrieving the offset of the
3103 environment from block zero's out-of-band data. The
3104 "nand env.oob" command can be used to record this offset.
3105 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3106 using CONFIG_ENV_OFFSET_OOB.
3108 - CONFIG_NAND_ENV_DST
3110 Defines address in RAM to which the nand_spl code should copy the
3111 environment. If redundant environment is used, it will be copied to
3112 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3114 - CONFIG_SYS_SPI_INIT_OFFSET
3116 Defines offset to the initial SPI buffer area in DPRAM. The
3117 area is used at an early stage (ROM part) if the environment
3118 is configured to reside in the SPI EEPROM: We need a 520 byte
3119 scratch DPRAM area. It is used between the two initialization
3120 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3121 to be a good choice since it makes it far enough from the
3122 start of the data area as well as from the stack pointer.
3124 Please note that the environment is read-only until the monitor
3125 has been relocated to RAM and a RAM copy of the environment has been
3126 created; also, when using EEPROM you will have to use getenv_f()
3127 until then to read environment variables.
3129 The environment is protected by a CRC32 checksum. Before the monitor
3130 is relocated into RAM, as a result of a bad CRC you will be working
3131 with the compiled-in default environment - *silently*!!! [This is
3132 necessary, because the first environment variable we need is the
3133 "baudrate" setting for the console - if we have a bad CRC, we don't
3134 have any device yet where we could complain.]
3136 Note: once the monitor has been relocated, then it will complain if
3137 the default environment is used; a new CRC is computed as soon as you
3138 use the "saveenv" command to store a valid environment.
3140 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3141 Echo the inverted Ethernet link state to the fault LED.
3143 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3144 also needs to be defined.
3146 - CONFIG_SYS_FAULT_MII_ADDR:
3147 MII address of the PHY to check for the Ethernet link state.
3149 - CONFIG_NS16550_MIN_FUNCTIONS:
3150 Define this if you desire to only have use of the NS16550_init
3151 and NS16550_putc functions for the serial driver located at
3152 drivers/serial/ns16550.c. This option is useful for saving
3153 space for already greatly restricted images, including but not
3154 limited to NAND_SPL configurations.
3156 Low Level (hardware related) configuration options:
3157 ---------------------------------------------------
3159 - CONFIG_SYS_CACHELINE_SIZE:
3160 Cache Line Size of the CPU.
3162 - CONFIG_SYS_DEFAULT_IMMR:
3163 Default address of the IMMR after system reset.
3165 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3166 and RPXsuper) to be able to adjust the position of
3167 the IMMR register after a reset.
3169 - CONFIG_SYS_CCSRBAR_DEFAULT:
3170 Default (power-on reset) physical address of CCSR on Freescale
3173 - CONFIG_SYS_CCSRBAR:
3174 Virtual address of CCSR. On a 32-bit build, this is typically
3175 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3177 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3178 for cross-platform code that uses that macro instead.
3180 - CONFIG_SYS_CCSRBAR_PHYS:
3181 Physical address of CCSR. CCSR can be relocated to a new
3182 physical address, if desired. In this case, this macro should
3183 be set to that address. Otherwise, it should be set to the
3184 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3185 is typically relocated on 36-bit builds. It is recommended
3186 that this macro be defined via the _HIGH and _LOW macros:
3188 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3189 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3191 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3192 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3193 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3194 used in assembly code, so it must not contain typecasts or
3195 integer size suffixes (e.g. "ULL").
3197 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3198 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3199 used in assembly code, so it must not contain typecasts or
3200 integer size suffixes (e.g. "ULL").
3202 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3203 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3204 forced to a value that ensures that CCSR is not relocated.
3206 - Floppy Disk Support:
3207 CONFIG_SYS_FDC_DRIVE_NUMBER
3209 the default drive number (default value 0)
3211 CONFIG_SYS_ISA_IO_STRIDE
3213 defines the spacing between FDC chipset registers
3216 CONFIG_SYS_ISA_IO_OFFSET
3218 defines the offset of register from address. It
3219 depends on which part of the data bus is connected to
3220 the FDC chipset. (default value 0)
3222 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3223 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3226 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3227 fdc_hw_init() is called at the beginning of the FDC
3228 setup. fdc_hw_init() must be provided by the board
3229 source code. It is used to make hardware dependant
3233 Most IDE controllers were designed to be connected with PCI
3234 interface. Only few of them were designed for AHB interface.
3235 When software is doing ATA command and data transfer to
3236 IDE devices through IDE-AHB controller, some additional
3237 registers accessing to these kind of IDE-AHB controller
3240 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3241 DO NOT CHANGE unless you know exactly what you're
3242 doing! (11-4) [MPC8xx/82xx systems only]
3244 - CONFIG_SYS_INIT_RAM_ADDR:
3246 Start address of memory area that can be used for
3247 initial data and stack; please note that this must be
3248 writable memory that is working WITHOUT special
3249 initialization, i. e. you CANNOT use normal RAM which
3250 will become available only after programming the
3251 memory controller and running certain initialization
3254 U-Boot uses the following memory types:
3255 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3256 - MPC824X: data cache
3257 - PPC4xx: data cache
3259 - CONFIG_SYS_GBL_DATA_OFFSET:
3261 Offset of the initial data structure in the memory
3262 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3263 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3264 data is located at the end of the available space
3265 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3266 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3267 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3268 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3271 On the MPC824X (or other systems that use the data
3272 cache for initial memory) the address chosen for
3273 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3274 point to an otherwise UNUSED address space between
3275 the top of RAM and the start of the PCI space.
3277 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3279 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3281 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3283 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3285 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3287 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3289 - CONFIG_SYS_OR_TIMING_SDRAM:
3292 - CONFIG_SYS_MAMR_PTA:
3293 periodic timer for refresh
3295 - CONFIG_SYS_DER: Debug Event Register (37-47)
3297 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3298 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3299 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3300 CONFIG_SYS_BR1_PRELIM:
3301 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3303 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3304 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3305 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3306 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3308 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3309 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3310 Machine Mode Register and Memory Periodic Timer
3311 Prescaler definitions (SDRAM timing)
3313 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3314 enable I2C microcode relocation patch (MPC8xx);
3315 define relocation offset in DPRAM [DSP2]
3317 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3318 enable SMC microcode relocation patch (MPC8xx);
3319 define relocation offset in DPRAM [SMC1]
3321 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3322 enable SPI microcode relocation patch (MPC8xx);
3323 define relocation offset in DPRAM [SCC4]
3325 - CONFIG_SYS_USE_OSCCLK:
3326 Use OSCM clock mode on MBX8xx board. Be careful,
3327 wrong setting might damage your board. Read
3328 doc/README.MBX before setting this variable!
3330 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3331 Offset of the bootmode word in DPRAM used by post
3332 (Power On Self Tests). This definition overrides
3333 #define'd default value in commproc.h resp.
3336 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3337 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3338 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3339 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3340 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3341 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3342 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3343 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3344 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3346 - CONFIG_PCI_DISABLE_PCIE:
3347 Disable PCI-Express on systems where it is supported but not
3351 Chip has SRIO or not
3354 Board has SRIO 1 port available
3357 Board has SRIO 2 port available
3359 - CONFIG_SYS_SRIOn_MEM_VIRT:
3360 Virtual Address of SRIO port 'n' memory region
3362 - CONFIG_SYS_SRIOn_MEM_PHYS:
3363 Physical Address of SRIO port 'n' memory region
3365 - CONFIG_SYS_SRIOn_MEM_SIZE:
3366 Size of SRIO port 'n' memory region
3368 - CONFIG_SYS_NDFC_16
3369 Defined to tell the NDFC that the NAND chip is using a
3372 - CONFIG_SYS_NDFC_EBC0_CFG
3373 Sets the EBC0_CFG register for the NDFC. If not defined
3374 a default value will be used.
3377 Get DDR timing information from an I2C EEPROM. Common
3378 with pluggable memory modules such as SODIMMs
3381 I2C address of the SPD EEPROM
3383 - CONFIG_SYS_SPD_BUS_NUM
3384 If SPD EEPROM is on an I2C bus other than the first
3385 one, specify here. Note that the value must resolve
3386 to something your driver can deal with.
3388 - CONFIG_SYS_DDR_RAW_TIMING
3389 Get DDR timing information from other than SPD. Common with
3390 soldered DDR chips onboard without SPD. DDR raw timing
3391 parameters are extracted from datasheet and hard-coded into
3392 header files or board specific files.
3394 - CONFIG_FSL_DDR_INTERACTIVE
3395 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3397 - CONFIG_SYS_83XX_DDR_USES_CS0
3398 Only for 83xx systems. If specified, then DDR should
3399 be configured using CS0 and CS1 instead of CS2 and CS3.
3401 - CONFIG_ETHER_ON_FEC[12]
3402 Define to enable FEC[12] on a 8xx series processor.
3404 - CONFIG_FEC[12]_PHY
3405 Define to the hardcoded PHY address which corresponds
3406 to the given FEC; i. e.
3407 #define CONFIG_FEC1_PHY 4
3408 means that the PHY with address 4 is connected to FEC1
3410 When set to -1, means to probe for first available.
3412 - CONFIG_FEC[12]_PHY_NORXERR
3413 The PHY does not have a RXERR line (RMII only).
3414 (so program the FEC to ignore it).
3417 Enable RMII mode for all FECs.
3418 Note that this is a global option, we can't
3419 have one FEC in standard MII mode and another in RMII mode.
3421 - CONFIG_CRC32_VERIFY
3422 Add a verify option to the crc32 command.
3425 => crc32 -v <address> <count> <crc32>
3427 Where address/count indicate a memory area
3428 and crc32 is the correct crc32 which the
3432 Add the "loopw" memory command. This only takes effect if
3433 the memory commands are activated globally (CONFIG_CMD_MEM).
3436 Add the "mdc" and "mwc" memory commands. These are cyclic
3441 This command will print 4 bytes (10,11,12,13) each 500 ms.
3443 => mwc.l 100 12345678 10
3444 This command will write 12345678 to address 100 all 10 ms.
3446 This only takes effect if the memory commands are activated
3447 globally (CONFIG_CMD_MEM).
3449 - CONFIG_SKIP_LOWLEVEL_INIT
3450 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3451 low level initializations (like setting up the memory
3452 controller) are omitted and/or U-Boot does not
3453 relocate itself into RAM.
3455 Normally this variable MUST NOT be defined. The only
3456 exception is when U-Boot is loaded (to RAM) by some
3457 other boot loader or by a debugger which performs
3458 these initializations itself.
3461 Modifies the behaviour of start.S when compiling a loader
3462 that is executed before the actual U-Boot. E.g. when
3463 compiling a NAND SPL.
3465 - CONFIG_USE_ARCH_MEMCPY
3466 CONFIG_USE_ARCH_MEMSET
3467 If these options are used a optimized version of memcpy/memset will
3468 be used if available. These functions may be faster under some
3469 conditions but may increase the binary size.
3471 Freescale QE/FMAN Firmware Support:
3472 -----------------------------------
3474 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3475 loading of "firmware", which is encoded in the QE firmware binary format.
3476 This firmware often needs to be loaded during U-Boot booting, so macros
3477 are used to identify the storage device (NOR flash, SPI, etc) and the address
3480 - CONFIG_SYS_QE_FMAN_FW_ADDR
3481 The address in the storage device where the firmware is located. The
3482 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3485 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3486 The maximum possible size of the firmware. The firmware binary format
3487 has a field that specifies the actual size of the firmware, but it
3488 might not be possible to read any part of the firmware unless some
3489 local storage is allocated to hold the entire firmware first.
3491 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3492 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3493 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3494 virtual address in NOR flash.
3496 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3497 Specifies that QE/FMAN firmware is located in NAND flash.
3498 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3500 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3501 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3502 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3504 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3505 Specifies that QE/FMAN firmware is located on the primary SPI
3506 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3508 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3509 Specifies that QE/FMAN firmware is located in the remote (master)
3510 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3511 can be mapped from slave TLB->slave LAW->slave SRIO outbound window
3512 ->master inbound window->master LAW->the ucode address in master's
3515 Building the Software:
3516 ======================
3518 Building U-Boot has been tested in several native build environments
3519 and in many different cross environments. Of course we cannot support
3520 all possibly existing versions of cross development tools in all
3521 (potentially obsolete) versions. In case of tool chain problems we
3522 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3523 which is extensively used to build and test U-Boot.
3525 If you are not using a native environment, it is assumed that you
3526 have GNU cross compiling tools available in your path. In this case,
3527 you must set the environment variable CROSS_COMPILE in your shell.
3528 Note that no changes to the Makefile or any other source files are
3529 necessary. For example using the ELDK on a 4xx CPU, please enter:
3531 $ CROSS_COMPILE=ppc_4xx-
3532 $ export CROSS_COMPILE
3534 Note: If you wish to generate Windows versions of the utilities in
3535 the tools directory you can use the MinGW toolchain
3536 (http://www.mingw.org). Set your HOST tools to the MinGW
3537 toolchain and execute 'make tools'. For example:
3539 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3541 Binaries such as tools/mkimage.exe will be created which can
3542 be executed on computers running Windows.
3544 U-Boot is intended to be simple to build. After installing the
3545 sources you must configure U-Boot for one specific board type. This
3550 where "NAME_config" is the name of one of the existing configu-
3551 rations; see boards.cfg for supported names.
3553 Note: for some board special configuration names may exist; check if
3554 additional information is available from the board vendor; for
3555 instance, the TQM823L systems are available without (standard)
3556 or with LCD support. You can select such additional "features"
3557 when choosing the configuration, i. e.
3560 - will configure for a plain TQM823L, i. e. no LCD support
3562 make TQM823L_LCD_config
3563 - will configure for a TQM823L with U-Boot console on LCD
3568 Finally, type "make all", and you should get some working U-Boot
3569 images ready for download to / installation on your system:
3571 - "u-boot.bin" is a raw binary image
3572 - "u-boot" is an image in ELF binary format
3573 - "u-boot.srec" is in Motorola S-Record format
3575 By default the build is performed locally and the objects are saved
3576 in the source directory. One of the two methods can be used to change
3577 this behavior and build U-Boot to some external directory:
3579 1. Add O= to the make command line invocations:
3581 make O=/tmp/build distclean
3582 make O=/tmp/build NAME_config
3583 make O=/tmp/build all
3585 2. Set environment variable BUILD_DIR to point to the desired location:
3587 export BUILD_DIR=/tmp/build
3592 Note that the command line "O=" setting overrides the BUILD_DIR environment
3596 Please be aware that the Makefiles assume you are using GNU make, so
3597 for instance on NetBSD you might need to use "gmake" instead of
3601 If the system board that you have is not listed, then you will need
3602 to port U-Boot to your hardware platform. To do this, follow these
3605 1. Add a new configuration option for your board to the toplevel
3606 "boards.cfg" file, using the existing entries as examples.
3607 Follow the instructions there to keep the boards in order.
3608 2. Create a new directory to hold your board specific code. Add any
3609 files you need. In your board directory, you will need at least
3610 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3611 3. Create a new configuration file "include/configs/<board>.h" for
3613 3. If you're porting U-Boot to a new CPU, then also create a new
3614 directory to hold your CPU specific code. Add any files you need.
3615 4. Run "make <board>_config" with your new name.
3616 5. Type "make", and you should get a working "u-boot.srec" file
3617 to be installed on your target system.
3618 6. Debug and solve any problems that might arise.
3619 [Of course, this last step is much harder than it sounds.]
3622 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3623 ==============================================================
3625 If you have modified U-Boot sources (for instance added a new board
3626 or support for new devices, a new CPU, etc.) you are expected to
3627 provide feedback to the other developers. The feedback normally takes
3628 the form of a "patch", i. e. a context diff against a certain (latest
3629 official or latest in the git repository) version of U-Boot sources.
3631 But before you submit such a patch, please verify that your modifi-
3632 cation did not break existing code. At least make sure that *ALL* of
3633 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3634 just run the "MAKEALL" script, which will configure and build U-Boot
3635 for ALL supported system. Be warned, this will take a while. You can
3636 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3637 environment variable to the script, i. e. to use the ELDK cross tools
3640 CROSS_COMPILE=ppc_8xx- MAKEALL
3642 or to build on a native PowerPC system you can type
3644 CROSS_COMPILE=' ' MAKEALL
3646 When using the MAKEALL script, the default behaviour is to build
3647 U-Boot in the source directory. This location can be changed by
3648 setting the BUILD_DIR environment variable. Also, for each target
3649 built, the MAKEALL script saves two log files (<target>.ERR and
3650 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3651 location can be changed by setting the MAKEALL_LOGDIR environment
3652 variable. For example:
3654 export BUILD_DIR=/tmp/build
3655 export MAKEALL_LOGDIR=/tmp/log
3656 CROSS_COMPILE=ppc_8xx- MAKEALL
3658 With the above settings build objects are saved in the /tmp/build,
3659 log files are saved in the /tmp/log and the source tree remains clean
3660 during the whole build process.
3663 See also "U-Boot Porting Guide" below.
3666 Monitor Commands - Overview:
3667 ============================
3669 go - start application at address 'addr'
3670 run - run commands in an environment variable
3671 bootm - boot application image from memory
3672 bootp - boot image via network using BootP/TFTP protocol
3673 bootz - boot zImage from memory
3674 tftpboot- boot image via network using TFTP protocol
3675 and env variables "ipaddr" and "serverip"
3676 (and eventually "gatewayip")
3677 tftpput - upload a file via network using TFTP protocol
3678 rarpboot- boot image via network using RARP/TFTP protocol
3679 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3680 loads - load S-Record file over serial line
3681 loadb - load binary file over serial line (kermit mode)
3683 mm - memory modify (auto-incrementing)
3684 nm - memory modify (constant address)
3685 mw - memory write (fill)
3687 cmp - memory compare
3688 crc32 - checksum calculation
3689 i2c - I2C sub-system
3690 sspi - SPI utility commands
3691 base - print or set address offset
3692 printenv- print environment variables
3693 setenv - set environment variables
3694 saveenv - save environment variables to persistent storage
3695 protect - enable or disable FLASH write protection
3696 erase - erase FLASH memory
3697 flinfo - print FLASH memory information
3698 bdinfo - print Board Info structure
3699 iminfo - print header information for application image
3700 coninfo - print console devices and informations
3701 ide - IDE sub-system
3702 loop - infinite loop on address range
3703 loopw - infinite write loop on address range
3704 mtest - simple RAM test
3705 icache - enable or disable instruction cache
3706 dcache - enable or disable data cache
3707 reset - Perform RESET of the CPU
3708 echo - echo args to console
3709 version - print monitor version
3710 help - print online help
3711 ? - alias for 'help'
3714 Monitor Commands - Detailed Description:
3715 ========================================
3719 For now: just type "help <command>".
3722 Environment Variables:
3723 ======================
3725 U-Boot supports user configuration using Environment Variables which
3726 can be made persistent by saving to Flash memory.
3728 Environment Variables are set using "setenv", printed using
3729 "printenv", and saved to Flash using "saveenv". Using "setenv"
3730 without a value can be used to delete a variable from the
3731 environment. As long as you don't save the environment you are
3732 working with an in-memory copy. In case the Flash area containing the
3733 environment is erased by accident, a default environment is provided.
3735 Some configuration options can be set using Environment Variables.
3737 List of environment variables (most likely not complete):
3739 baudrate - see CONFIG_BAUDRATE
3741 bootdelay - see CONFIG_BOOTDELAY
3743 bootcmd - see CONFIG_BOOTCOMMAND
3745 bootargs - Boot arguments when booting an RTOS image
3747 bootfile - Name of the image to load with TFTP
3749 bootm_low - Memory range available for image processing in the bootm
3750 command can be restricted. This variable is given as
3751 a hexadecimal number and defines lowest address allowed
3752 for use by the bootm command. See also "bootm_size"
3753 environment variable. Address defined by "bootm_low" is
3754 also the base of the initial memory mapping for the Linux
3755 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3758 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3759 This variable is given as a hexadecimal number and it
3760 defines the size of the memory region starting at base
3761 address bootm_low that is accessible by the Linux kernel
3762 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3763 as the default value if it is defined, and bootm_size is
3766 bootm_size - Memory range available for image processing in the bootm
3767 command can be restricted. This variable is given as
3768 a hexadecimal number and defines the size of the region
3769 allowed for use by the bootm command. See also "bootm_low"
3770 environment variable.
3772 updatefile - Location of the software update file on a TFTP server, used
3773 by the automatic software update feature. Please refer to
3774 documentation in doc/README.update for more details.
3776 autoload - if set to "no" (any string beginning with 'n'),
3777 "bootp" will just load perform a lookup of the
3778 configuration from the BOOTP server, but not try to
3779 load any image using TFTP
3781 autostart - if set to "yes", an image loaded using the "bootp",
3782 "rarpboot", "tftpboot" or "diskboot" commands will
3783 be automatically started (by internally calling
3786 If set to "no", a standalone image passed to the
3787 "bootm" command will be copied to the load address
3788 (and eventually uncompressed), but NOT be started.
3789 This can be used to load and uncompress arbitrary
3792 fdt_high - if set this restricts the maximum address that the
3793 flattened device tree will be copied into upon boot.
3794 For example, if you have a system with 1 GB memory
3795 at physical address 0x10000000, while Linux kernel
3796 only recognizes the first 704 MB as low memory, you
3797 may need to set fdt_high as 0x3C000000 to have the
3798 device tree blob be copied to the maximum address
3799 of the 704 MB low memory, so that Linux kernel can
3800 access it during the boot procedure.
3802 If this is set to the special value 0xFFFFFFFF then
3803 the fdt will not be copied at all on boot. For this
3804 to work it must reside in writable memory, have
3805 sufficient padding on the end of it for u-boot to
3806 add the information it needs into it, and the memory
3807 must be accessible by the kernel.
3809 fdtcontroladdr- if set this is the address of the control flattened
3810 device tree used by U-Boot when CONFIG_OF_CONTROL is
3813 i2cfast - (PPC405GP|PPC405EP only)
3814 if set to 'y' configures Linux I2C driver for fast
3815 mode (400kHZ). This environment variable is used in
3816 initialization code. So, for changes to be effective
3817 it must be saved and board must be reset.
3819 initrd_high - restrict positioning of initrd images:
3820 If this variable is not set, initrd images will be
3821 copied to the highest possible address in RAM; this
3822 is usually what you want since it allows for
3823 maximum initrd size. If for some reason you want to
3824 make sure that the initrd image is loaded below the
3825 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3826 variable to a value of "no" or "off" or "0".
3827 Alternatively, you can set it to a maximum upper
3828 address to use (U-Boot will still check that it
3829 does not overwrite the U-Boot stack and data).
3831 For instance, when you have a system with 16 MB
3832 RAM, and want to reserve 4 MB from use by Linux,
3833 you can do this by adding "mem=12M" to the value of
3834 the "bootargs" variable. However, now you must make
3835 sure that the initrd image is placed in the first
3836 12 MB as well - this can be done with
3838 setenv initrd_high 00c00000
3840 If you set initrd_high to 0xFFFFFFFF, this is an
3841 indication to U-Boot that all addresses are legal
3842 for the Linux kernel, including addresses in flash
3843 memory. In this case U-Boot will NOT COPY the
3844 ramdisk at all. This may be useful to reduce the
3845 boot time on your system, but requires that this
3846 feature is supported by your Linux kernel.
3848 ipaddr - IP address; needed for tftpboot command
3850 loadaddr - Default load address for commands like "bootp",
3851 "rarpboot", "tftpboot", "loadb" or "diskboot"
3853 loads_echo - see CONFIG_LOADS_ECHO
3855 serverip - TFTP server IP address; needed for tftpboot command
3857 bootretry - see CONFIG_BOOT_RETRY_TIME
3859 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3861 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3863 ethprime - controls which interface is used first.
3865 ethact - controls which interface is currently active.
3866 For example you can do the following
3868 => setenv ethact FEC
3869 => ping 192.168.0.1 # traffic sent on FEC
3870 => setenv ethact SCC
3871 => ping 10.0.0.1 # traffic sent on SCC
3873 ethrotate - When set to "no" U-Boot does not go through all
3874 available network interfaces.
3875 It just stays at the currently selected interface.
3877 netretry - When set to "no" each network operation will
3878 either succeed or fail without retrying.
3879 When set to "once" the network operation will
3880 fail when all the available network interfaces
3881 are tried once without success.
3882 Useful on scripts which control the retry operation
3885 npe_ucode - set load address for the NPE microcode
3887 tftpsrcport - If this is set, the value is used for TFTP's
3890 tftpdstport - If this is set, the value is used for TFTP's UDP
3891 destination port instead of the Well Know Port 69.
3893 tftpblocksize - Block size to use for TFTP transfers; if not set,
3894 we use the TFTP server's default block size
3896 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3897 seconds, minimum value is 1000 = 1 second). Defines
3898 when a packet is considered to be lost so it has to
3899 be retransmitted. The default is 5000 = 5 seconds.
3900 Lowering this value may make downloads succeed
3901 faster in networks with high packet loss rates or
3902 with unreliable TFTP servers.
3904 vlan - When set to a value < 4095 the traffic over
3905 Ethernet is encapsulated/received over 802.1q
3908 The following image location variables contain the location of images
3909 used in booting. The "Image" column gives the role of the image and is
3910 not an environment variable name. The other columns are environment
3911 variable names. "File Name" gives the name of the file on a TFTP
3912 server, "RAM Address" gives the location in RAM the image will be
3913 loaded to, and "Flash Location" gives the image's address in NOR
3914 flash or offset in NAND flash.
3916 *Note* - these variables don't have to be defined for all boards, some
3917 boards currenlty use other variables for these purposes, and some
3918 boards use these variables for other purposes.
3920 Image File Name RAM Address Flash Location
3921 ----- --------- ----------- --------------
3922 u-boot u-boot u-boot_addr_r u-boot_addr
3923 Linux kernel bootfile kernel_addr_r kernel_addr
3924 device tree blob fdtfile fdt_addr_r fdt_addr
3925 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
3927 The following environment variables may be used and automatically
3928 updated by the network boot commands ("bootp" and "rarpboot"),
3929 depending the information provided by your boot server:
3931 bootfile - see above
3932 dnsip - IP address of your Domain Name Server
3933 dnsip2 - IP address of your secondary Domain Name Server
3934 gatewayip - IP address of the Gateway (Router) to use
3935 hostname - Target hostname
3937 netmask - Subnet Mask
3938 rootpath - Pathname of the root filesystem on the NFS server
3939 serverip - see above
3942 There are two special Environment Variables:
3944 serial# - contains hardware identification information such
3945 as type string and/or serial number
3946 ethaddr - Ethernet address
3948 These variables can be set only once (usually during manufacturing of
3949 the board). U-Boot refuses to delete or overwrite these variables
3950 once they have been set once.
3953 Further special Environment Variables:
3955 ver - Contains the U-Boot version string as printed
3956 with the "version" command. This variable is
3957 readonly (see CONFIG_VERSION_VARIABLE).
3960 Please note that changes to some configuration parameters may take
3961 only effect after the next boot (yes, that's just like Windoze :-).
3964 Command Line Parsing:
3965 =====================
3967 There are two different command line parsers available with U-Boot:
3968 the old "simple" one, and the much more powerful "hush" shell:
3970 Old, simple command line parser:
3971 --------------------------------
3973 - supports environment variables (through setenv / saveenv commands)
3974 - several commands on one line, separated by ';'
3975 - variable substitution using "... ${name} ..." syntax
3976 - special characters ('$', ';') can be escaped by prefixing with '\',
3978 setenv bootcmd bootm \${address}
3979 - You can also escape text by enclosing in single apostrophes, for example:
3980 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3985 - similar to Bourne shell, with control structures like
3986 if...then...else...fi, for...do...done; while...do...done,
3987 until...do...done, ...
3988 - supports environment ("global") variables (through setenv / saveenv
3989 commands) and local shell variables (through standard shell syntax
3990 "name=value"); only environment variables can be used with "run"
3996 (1) If a command line (or an environment variable executed by a "run"
3997 command) contains several commands separated by semicolon, and
3998 one of these commands fails, then the remaining commands will be
4001 (2) If you execute several variables with one call to run (i. e.
4002 calling run with a list of variables as arguments), any failing
4003 command will cause "run" to terminate, i. e. the remaining
4004 variables are not executed.
4006 Note for Redundant Ethernet Interfaces:
4007 =======================================
4009 Some boards come with redundant Ethernet interfaces; U-Boot supports
4010 such configurations and is capable of automatic selection of a
4011 "working" interface when needed. MAC assignment works as follows:
4013 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4014 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4015 "eth1addr" (=>eth1), "eth2addr", ...
4017 If the network interface stores some valid MAC address (for instance
4018 in SROM), this is used as default address if there is NO correspon-
4019 ding setting in the environment; if the corresponding environment
4020 variable is set, this overrides the settings in the card; that means:
4022 o If the SROM has a valid MAC address, and there is no address in the
4023 environment, the SROM's address is used.
4025 o If there is no valid address in the SROM, and a definition in the
4026 environment exists, then the value from the environment variable is
4029 o If both the SROM and the environment contain a MAC address, and
4030 both addresses are the same, this MAC address is used.
4032 o If both the SROM and the environment contain a MAC address, and the
4033 addresses differ, the value from the environment is used and a
4036 o If neither SROM nor the environment contain a MAC address, an error
4039 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4040 will be programmed into hardware as part of the initialization process. This
4041 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4042 The naming convention is as follows:
4043 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4048 U-Boot is capable of booting (and performing other auxiliary operations on)
4049 images in two formats:
4051 New uImage format (FIT)
4052 -----------------------
4054 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4055 to Flattened Device Tree). It allows the use of images with multiple
4056 components (several kernels, ramdisks, etc.), with contents protected by
4057 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4063 Old image format is based on binary files which can be basically anything,
4064 preceded by a special header; see the definitions in include/image.h for
4065 details; basically, the header defines the following image properties:
4067 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4068 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4069 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4070 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4072 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4073 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4074 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4075 * Compression Type (uncompressed, gzip, bzip2)
4081 The header is marked by a special Magic Number, and both the header
4082 and the data portions of the image are secured against corruption by
4089 Although U-Boot should support any OS or standalone application
4090 easily, the main focus has always been on Linux during the design of
4093 U-Boot includes many features that so far have been part of some
4094 special "boot loader" code within the Linux kernel. Also, any
4095 "initrd" images to be used are no longer part of one big Linux image;
4096 instead, kernel and "initrd" are separate images. This implementation
4097 serves several purposes:
4099 - the same features can be used for other OS or standalone
4100 applications (for instance: using compressed images to reduce the
4101 Flash memory footprint)
4103 - it becomes much easier to port new Linux kernel versions because
4104 lots of low-level, hardware dependent stuff are done by U-Boot
4106 - the same Linux kernel image can now be used with different "initrd"
4107 images; of course this also means that different kernel images can
4108 be run with the same "initrd". This makes testing easier (you don't
4109 have to build a new "zImage.initrd" Linux image when you just
4110 change a file in your "initrd"). Also, a field-upgrade of the
4111 software is easier now.
4117 Porting Linux to U-Boot based systems:
4118 ---------------------------------------
4120 U-Boot cannot save you from doing all the necessary modifications to
4121 configure the Linux device drivers for use with your target hardware
4122 (no, we don't intend to provide a full virtual machine interface to
4125 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4127 Just make sure your machine specific header file (for instance
4128 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4129 Information structure as we define in include/asm-<arch>/u-boot.h,
4130 and make sure that your definition of IMAP_ADDR uses the same value
4131 as your U-Boot configuration in CONFIG_SYS_IMMR.
4134 Configuring the Linux kernel:
4135 -----------------------------
4137 No specific requirements for U-Boot. Make sure you have some root
4138 device (initial ramdisk, NFS) for your target system.
4141 Building a Linux Image:
4142 -----------------------
4144 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4145 not used. If you use recent kernel source, a new build target
4146 "uImage" will exist which automatically builds an image usable by
4147 U-Boot. Most older kernels also have support for a "pImage" target,
4148 which was introduced for our predecessor project PPCBoot and uses a
4149 100% compatible format.
4158 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4159 encapsulate a compressed Linux kernel image with header information,
4160 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4162 * build a standard "vmlinux" kernel image (in ELF binary format):
4164 * convert the kernel into a raw binary image:
4166 ${CROSS_COMPILE}-objcopy -O binary \
4167 -R .note -R .comment \
4168 -S vmlinux linux.bin
4170 * compress the binary image:
4174 * package compressed binary image for U-Boot:
4176 mkimage -A ppc -O linux -T kernel -C gzip \
4177 -a 0 -e 0 -n "Linux Kernel Image" \
4178 -d linux.bin.gz uImage
4181 The "mkimage" tool can also be used to create ramdisk images for use
4182 with U-Boot, either separated from the Linux kernel image, or
4183 combined into one file. "mkimage" encapsulates the images with a 64
4184 byte header containing information about target architecture,
4185 operating system, image type, compression method, entry points, time
4186 stamp, CRC32 checksums, etc.
4188 "mkimage" can be called in two ways: to verify existing images and
4189 print the header information, or to build new images.
4191 In the first form (with "-l" option) mkimage lists the information
4192 contained in the header of an existing U-Boot image; this includes
4193 checksum verification:
4195 tools/mkimage -l image
4196 -l ==> list image header information
4198 The second form (with "-d" option) is used to build a U-Boot image
4199 from a "data file" which is used as image payload:
4201 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4202 -n name -d data_file image
4203 -A ==> set architecture to 'arch'
4204 -O ==> set operating system to 'os'
4205 -T ==> set image type to 'type'
4206 -C ==> set compression type 'comp'
4207 -a ==> set load address to 'addr' (hex)
4208 -e ==> set entry point to 'ep' (hex)
4209 -n ==> set image name to 'name'
4210 -d ==> use image data from 'datafile'
4212 Right now, all Linux kernels for PowerPC systems use the same load
4213 address (0x00000000), but the entry point address depends on the
4216 - 2.2.x kernels have the entry point at 0x0000000C,
4217 - 2.3.x and later kernels have the entry point at 0x00000000.
4219 So a typical call to build a U-Boot image would read:
4221 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4222 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4223 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4224 > examples/uImage.TQM850L
4225 Image Name: 2.4.4 kernel for TQM850L
4226 Created: Wed Jul 19 02:34:59 2000
4227 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4228 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4229 Load Address: 0x00000000
4230 Entry Point: 0x00000000
4232 To verify the contents of the image (or check for corruption):
4234 -> tools/mkimage -l examples/uImage.TQM850L
4235 Image Name: 2.4.4 kernel for TQM850L
4236 Created: Wed Jul 19 02:34:59 2000
4237 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4238 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4239 Load Address: 0x00000000
4240 Entry Point: 0x00000000
4242 NOTE: for embedded systems where boot time is critical you can trade
4243 speed for memory and install an UNCOMPRESSED image instead: this
4244 needs more space in Flash, but boots much faster since it does not
4245 need to be uncompressed:
4247 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4248 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4249 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4250 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4251 > examples/uImage.TQM850L-uncompressed
4252 Image Name: 2.4.4 kernel for TQM850L
4253 Created: Wed Jul 19 02:34:59 2000
4254 Image Type: PowerPC Linux Kernel Image (uncompressed)
4255 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4256 Load Address: 0x00000000
4257 Entry Point: 0x00000000
4260 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4261 when your kernel is intended to use an initial ramdisk:
4263 -> tools/mkimage -n 'Simple Ramdisk Image' \
4264 > -A ppc -O linux -T ramdisk -C gzip \
4265 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4266 Image Name: Simple Ramdisk Image
4267 Created: Wed Jan 12 14:01:50 2000
4268 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4269 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4270 Load Address: 0x00000000
4271 Entry Point: 0x00000000
4274 Installing a Linux Image:
4275 -------------------------
4277 To downloading a U-Boot image over the serial (console) interface,
4278 you must convert the image to S-Record format:
4280 objcopy -I binary -O srec examples/image examples/image.srec
4282 The 'objcopy' does not understand the information in the U-Boot
4283 image header, so the resulting S-Record file will be relative to
4284 address 0x00000000. To load it to a given address, you need to
4285 specify the target address as 'offset' parameter with the 'loads'
4288 Example: install the image to address 0x40100000 (which on the
4289 TQM8xxL is in the first Flash bank):
4291 => erase 40100000 401FFFFF
4297 ## Ready for S-Record download ...
4298 ~>examples/image.srec
4299 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4301 15989 15990 15991 15992
4302 [file transfer complete]
4304 ## Start Addr = 0x00000000
4307 You can check the success of the download using the 'iminfo' command;
4308 this includes a checksum verification so you can be sure no data
4309 corruption happened:
4313 ## Checking Image at 40100000 ...
4314 Image Name: 2.2.13 for initrd on TQM850L
4315 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4316 Data Size: 335725 Bytes = 327 kB = 0 MB
4317 Load Address: 00000000
4318 Entry Point: 0000000c
4319 Verifying Checksum ... OK
4325 The "bootm" command is used to boot an application that is stored in
4326 memory (RAM or Flash). In case of a Linux kernel image, the contents
4327 of the "bootargs" environment variable is passed to the kernel as
4328 parameters. You can check and modify this variable using the
4329 "printenv" and "setenv" commands:
4332 => printenv bootargs
4333 bootargs=root=/dev/ram
4335 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4337 => printenv bootargs
4338 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4341 ## Booting Linux kernel at 40020000 ...
4342 Image Name: 2.2.13 for NFS on TQM850L
4343 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4344 Data Size: 381681 Bytes = 372 kB = 0 MB
4345 Load Address: 00000000
4346 Entry Point: 0000000c
4347 Verifying Checksum ... OK
4348 Uncompressing Kernel Image ... OK
4349 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
4350 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4351 time_init: decrementer frequency = 187500000/60
4352 Calibrating delay loop... 49.77 BogoMIPS
4353 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4356 If you want to boot a Linux kernel with initial RAM disk, you pass
4357 the memory addresses of both the kernel and the initrd image (PPBCOOT
4358 format!) to the "bootm" command:
4360 => imi 40100000 40200000
4362 ## Checking Image at 40100000 ...
4363 Image Name: 2.2.13 for initrd on TQM850L
4364 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4365 Data Size: 335725 Bytes = 327 kB = 0 MB
4366 Load Address: 00000000
4367 Entry Point: 0000000c
4368 Verifying Checksum ... OK
4370 ## Checking Image at 40200000 ...
4371 Image Name: Simple Ramdisk Image
4372 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4373 Data Size: 566530 Bytes = 553 kB = 0 MB
4374 Load Address: 00000000
4375 Entry Point: 00000000
4376 Verifying Checksum ... OK
4378 => bootm 40100000 40200000
4379 ## Booting Linux kernel at 40100000 ...
4380 Image Name: 2.2.13 for initrd on TQM850L
4381 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4382 Data Size: 335725 Bytes = 327 kB = 0 MB
4383 Load Address: 00000000
4384 Entry Point: 0000000c
4385 Verifying Checksum ... OK
4386 Uncompressing Kernel Image ... OK
4387 ## Loading RAMDisk Image at 40200000 ...
4388 Image Name: Simple Ramdisk Image
4389 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4390 Data Size: 566530 Bytes = 553 kB = 0 MB
4391 Load Address: 00000000
4392 Entry Point: 00000000
4393 Verifying Checksum ... OK
4394 Loading Ramdisk ... OK
4395 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
4396 Boot arguments: root=/dev/ram
4397 time_init: decrementer frequency = 187500000/60
4398 Calibrating delay loop... 49.77 BogoMIPS
4400 RAMDISK: Compressed image found at block 0
4401 VFS: Mounted root (ext2 filesystem).
4405 Boot Linux and pass a flat device tree:
4408 First, U-Boot must be compiled with the appropriate defines. See the section
4409 titled "Linux Kernel Interface" above for a more in depth explanation. The
4410 following is an example of how to start a kernel and pass an updated
4416 oft=oftrees/mpc8540ads.dtb
4417 => tftp $oftaddr $oft
4418 Speed: 1000, full duplex
4420 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4421 Filename 'oftrees/mpc8540ads.dtb'.
4422 Load address: 0x300000
4425 Bytes transferred = 4106 (100a hex)
4426 => tftp $loadaddr $bootfile
4427 Speed: 1000, full duplex
4429 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4431 Load address: 0x200000
4432 Loading:############
4434 Bytes transferred = 1029407 (fb51f hex)
4439 => bootm $loadaddr - $oftaddr
4440 ## Booting image at 00200000 ...
4441 Image Name: Linux-2.6.17-dirty
4442 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4443 Data Size: 1029343 Bytes = 1005.2 kB
4444 Load Address: 00000000
4445 Entry Point: 00000000
4446 Verifying Checksum ... OK
4447 Uncompressing Kernel Image ... OK
4448 Booting using flat device tree at 0x300000
4449 Using MPC85xx ADS machine description
4450 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4454 More About U-Boot Image Types:
4455 ------------------------------
4457 U-Boot supports the following image types:
4459 "Standalone Programs" are directly runnable in the environment
4460 provided by U-Boot; it is expected that (if they behave
4461 well) you can continue to work in U-Boot after return from
4462 the Standalone Program.
4463 "OS Kernel Images" are usually images of some Embedded OS which
4464 will take over control completely. Usually these programs
4465 will install their own set of exception handlers, device
4466 drivers, set up the MMU, etc. - this means, that you cannot
4467 expect to re-enter U-Boot except by resetting the CPU.
4468 "RAMDisk Images" are more or less just data blocks, and their
4469 parameters (address, size) are passed to an OS kernel that is
4471 "Multi-File Images" contain several images, typically an OS
4472 (Linux) kernel image and one or more data images like
4473 RAMDisks. This construct is useful for instance when you want
4474 to boot over the network using BOOTP etc., where the boot
4475 server provides just a single image file, but you want to get
4476 for instance an OS kernel and a RAMDisk image.
4478 "Multi-File Images" start with a list of image sizes, each
4479 image size (in bytes) specified by an "uint32_t" in network
4480 byte order. This list is terminated by an "(uint32_t)0".
4481 Immediately after the terminating 0 follow the images, one by
4482 one, all aligned on "uint32_t" boundaries (size rounded up to
4483 a multiple of 4 bytes).
4485 "Firmware Images" are binary images containing firmware (like
4486 U-Boot or FPGA images) which usually will be programmed to
4489 "Script files" are command sequences that will be executed by
4490 U-Boot's command interpreter; this feature is especially
4491 useful when you configure U-Boot to use a real shell (hush)
4492 as command interpreter.
4494 Booting the Linux zImage:
4495 -------------------------
4497 On some platforms, it's possible to boot Linux zImage. This is done
4498 using the "bootz" command. The syntax of "bootz" command is the same
4499 as the syntax of "bootm" command.
4501 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4502 kernel with raw initrd images. The syntax is slightly different, the
4503 address of the initrd must be augmented by it's size, in the following
4504 format: "<initrd addres>:<initrd size>".
4510 One of the features of U-Boot is that you can dynamically load and
4511 run "standalone" applications, which can use some resources of
4512 U-Boot like console I/O functions or interrupt services.
4514 Two simple examples are included with the sources:
4519 'examples/hello_world.c' contains a small "Hello World" Demo
4520 application; it is automatically compiled when you build U-Boot.
4521 It's configured to run at address 0x00040004, so you can play with it
4525 ## Ready for S-Record download ...
4526 ~>examples/hello_world.srec
4527 1 2 3 4 5 6 7 8 9 10 11 ...
4528 [file transfer complete]
4530 ## Start Addr = 0x00040004
4532 => go 40004 Hello World! This is a test.
4533 ## Starting application at 0x00040004 ...
4544 Hit any key to exit ...
4546 ## Application terminated, rc = 0x0
4548 Another example, which demonstrates how to register a CPM interrupt
4549 handler with the U-Boot code, can be found in 'examples/timer.c'.
4550 Here, a CPM timer is set up to generate an interrupt every second.
4551 The interrupt service routine is trivial, just printing a '.'
4552 character, but this is just a demo program. The application can be
4553 controlled by the following keys:
4555 ? - print current values og the CPM Timer registers
4556 b - enable interrupts and start timer
4557 e - stop timer and disable interrupts
4558 q - quit application
4561 ## Ready for S-Record download ...
4562 ~>examples/timer.srec
4563 1 2 3 4 5 6 7 8 9 10 11 ...
4564 [file transfer complete]
4566 ## Start Addr = 0x00040004
4569 ## Starting application at 0x00040004 ...
4572 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4575 [q, b, e, ?] Set interval 1000000 us
4578 [q, b, e, ?] ........
4579 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4582 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4585 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4588 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4590 [q, b, e, ?] ...Stopping timer
4592 [q, b, e, ?] ## Application terminated, rc = 0x0
4598 Over time, many people have reported problems when trying to use the
4599 "minicom" terminal emulation program for serial download. I (wd)
4600 consider minicom to be broken, and recommend not to use it. Under
4601 Unix, I recommend to use C-Kermit for general purpose use (and
4602 especially for kermit binary protocol download ("loadb" command), and
4603 use "cu" for S-Record download ("loads" command).
4605 Nevertheless, if you absolutely want to use it try adding this
4606 configuration to your "File transfer protocols" section:
4608 Name Program Name U/D FullScr IO-Red. Multi
4609 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4610 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4616 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4617 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4619 Building requires a cross environment; it is known to work on
4620 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4621 need gmake since the Makefiles are not compatible with BSD make).
4622 Note that the cross-powerpc package does not install include files;
4623 attempting to build U-Boot will fail because <machine/ansi.h> is
4624 missing. This file has to be installed and patched manually:
4626 # cd /usr/pkg/cross/powerpc-netbsd/include
4628 # ln -s powerpc machine
4629 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4630 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4632 Native builds *don't* work due to incompatibilities between native
4633 and U-Boot include files.
4635 Booting assumes that (the first part of) the image booted is a
4636 stage-2 loader which in turn loads and then invokes the kernel
4637 proper. Loader sources will eventually appear in the NetBSD source
4638 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4639 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4642 Implementation Internals:
4643 =========================
4645 The following is not intended to be a complete description of every
4646 implementation detail. However, it should help to understand the
4647 inner workings of U-Boot and make it easier to port it to custom
4651 Initial Stack, Global Data:
4652 ---------------------------
4654 The implementation of U-Boot is complicated by the fact that U-Boot
4655 starts running out of ROM (flash memory), usually without access to
4656 system RAM (because the memory controller is not initialized yet).
4657 This means that we don't have writable Data or BSS segments, and BSS
4658 is not initialized as zero. To be able to get a C environment working
4659 at all, we have to allocate at least a minimal stack. Implementation
4660 options for this are defined and restricted by the CPU used: Some CPU
4661 models provide on-chip memory (like the IMMR area on MPC8xx and
4662 MPC826x processors), on others (parts of) the data cache can be
4663 locked as (mis-) used as memory, etc.
4665 Chris Hallinan posted a good summary of these issues to the
4666 U-Boot mailing list:
4668 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4669 From: "Chris Hallinan" <clh@net1plus.com>
4670 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4673 Correct me if I'm wrong, folks, but the way I understand it
4674 is this: Using DCACHE as initial RAM for Stack, etc, does not
4675 require any physical RAM backing up the cache. The cleverness
4676 is that the cache is being used as a temporary supply of
4677 necessary storage before the SDRAM controller is setup. It's
4678 beyond the scope of this list to explain the details, but you
4679 can see how this works by studying the cache architecture and
4680 operation in the architecture and processor-specific manuals.
4682 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4683 is another option for the system designer to use as an
4684 initial stack/RAM area prior to SDRAM being available. Either
4685 option should work for you. Using CS 4 should be fine if your
4686 board designers haven't used it for something that would
4687 cause you grief during the initial boot! It is frequently not
4690 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4691 with your processor/board/system design. The default value
4692 you will find in any recent u-boot distribution in
4693 walnut.h should work for you. I'd set it to a value larger
4694 than your SDRAM module. If you have a 64MB SDRAM module, set
4695 it above 400_0000. Just make sure your board has no resources
4696 that are supposed to respond to that address! That code in
4697 start.S has been around a while and should work as is when
4698 you get the config right.
4703 It is essential to remember this, since it has some impact on the C
4704 code for the initialization procedures:
4706 * Initialized global data (data segment) is read-only. Do not attempt
4709 * Do not use any uninitialized global data (or implicitely initialized
4710 as zero data - BSS segment) at all - this is undefined, initiali-
4711 zation is performed later (when relocating to RAM).
4713 * Stack space is very limited. Avoid big data buffers or things like
4716 Having only the stack as writable memory limits means we cannot use
4717 normal global data to share information beween the code. But it
4718 turned out that the implementation of U-Boot can be greatly
4719 simplified by making a global data structure (gd_t) available to all
4720 functions. We could pass a pointer to this data as argument to _all_
4721 functions, but this would bloat the code. Instead we use a feature of
4722 the GCC compiler (Global Register Variables) to share the data: we
4723 place a pointer (gd) to the global data into a register which we
4724 reserve for this purpose.
4726 When choosing a register for such a purpose we are restricted by the
4727 relevant (E)ABI specifications for the current architecture, and by
4728 GCC's implementation.
4730 For PowerPC, the following registers have specific use:
4732 R2: reserved for system use
4733 R3-R4: parameter passing and return values
4734 R5-R10: parameter passing
4735 R13: small data area pointer
4739 (U-Boot also uses R12 as internal GOT pointer. r12
4740 is a volatile register so r12 needs to be reset when
4741 going back and forth between asm and C)
4743 ==> U-Boot will use R2 to hold a pointer to the global data
4745 Note: on PPC, we could use a static initializer (since the
4746 address of the global data structure is known at compile time),
4747 but it turned out that reserving a register results in somewhat
4748 smaller code - although the code savings are not that big (on
4749 average for all boards 752 bytes for the whole U-Boot image,
4750 624 text + 127 data).
4752 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4753 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4755 ==> U-Boot will use P3 to hold a pointer to the global data
4757 On ARM, the following registers are used:
4759 R0: function argument word/integer result
4760 R1-R3: function argument word
4762 R10: stack limit (used only if stack checking if enabled)
4763 R11: argument (frame) pointer
4764 R12: temporary workspace
4767 R15: program counter
4769 ==> U-Boot will use R8 to hold a pointer to the global data
4771 On Nios II, the ABI is documented here:
4772 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4774 ==> U-Boot will use gp to hold a pointer to the global data
4776 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4777 to access small data sections, so gp is free.
4779 On NDS32, the following registers are used:
4781 R0-R1: argument/return
4783 R15: temporary register for assembler
4784 R16: trampoline register
4785 R28: frame pointer (FP)
4786 R29: global pointer (GP)
4787 R30: link register (LP)
4788 R31: stack pointer (SP)
4789 PC: program counter (PC)
4791 ==> U-Boot will use R10 to hold a pointer to the global data
4793 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4794 or current versions of GCC may "optimize" the code too much.
4799 U-Boot runs in system state and uses physical addresses, i.e. the
4800 MMU is not used either for address mapping nor for memory protection.
4802 The available memory is mapped to fixed addresses using the memory
4803 controller. In this process, a contiguous block is formed for each
4804 memory type (Flash, SDRAM, SRAM), even when it consists of several
4805 physical memory banks.
4807 U-Boot is installed in the first 128 kB of the first Flash bank (on
4808 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4809 booting and sizing and initializing DRAM, the code relocates itself
4810 to the upper end of DRAM. Immediately below the U-Boot code some
4811 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4812 configuration setting]. Below that, a structure with global Board
4813 Info data is placed, followed by the stack (growing downward).
4815 Additionally, some exception handler code is copied to the low 8 kB
4816 of DRAM (0x00000000 ... 0x00001FFF).
4818 So a typical memory configuration with 16 MB of DRAM could look like
4821 0x0000 0000 Exception Vector code
4824 0x0000 2000 Free for Application Use
4830 0x00FB FF20 Monitor Stack (Growing downward)
4831 0x00FB FFAC Board Info Data and permanent copy of global data
4832 0x00FC 0000 Malloc Arena
4835 0x00FE 0000 RAM Copy of Monitor Code
4836 ... eventually: LCD or video framebuffer
4837 ... eventually: pRAM (Protected RAM - unchanged by reset)
4838 0x00FF FFFF [End of RAM]
4841 System Initialization:
4842 ----------------------
4844 In the reset configuration, U-Boot starts at the reset entry point
4845 (on most PowerPC systems at address 0x00000100). Because of the reset
4846 configuration for CS0# this is a mirror of the onboard Flash memory.
4847 To be able to re-map memory U-Boot then jumps to its link address.
4848 To be able to implement the initialization code in C, a (small!)
4849 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4850 which provide such a feature like MPC8xx or MPC8260), or in a locked
4851 part of the data cache. After that, U-Boot initializes the CPU core,
4852 the caches and the SIU.
4854 Next, all (potentially) available memory banks are mapped using a
4855 preliminary mapping. For example, we put them on 512 MB boundaries
4856 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4857 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4858 programmed for SDRAM access. Using the temporary configuration, a
4859 simple memory test is run that determines the size of the SDRAM
4862 When there is more than one SDRAM bank, and the banks are of
4863 different size, the largest is mapped first. For equal size, the first
4864 bank (CS2#) is mapped first. The first mapping is always for address
4865 0x00000000, with any additional banks following immediately to create
4866 contiguous memory starting from 0.
4868 Then, the monitor installs itself at the upper end of the SDRAM area
4869 and allocates memory for use by malloc() and for the global Board
4870 Info data; also, the exception vector code is copied to the low RAM
4871 pages, and the final stack is set up.
4873 Only after this relocation will you have a "normal" C environment;
4874 until that you are restricted in several ways, mostly because you are
4875 running from ROM, and because the code will have to be relocated to a
4879 U-Boot Porting Guide:
4880 ----------------------
4882 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4886 int main(int argc, char *argv[])
4888 sighandler_t no_more_time;
4890 signal(SIGALRM, no_more_time);
4891 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4893 if (available_money > available_manpower) {
4894 Pay consultant to port U-Boot;
4898 Download latest U-Boot source;
4900 Subscribe to u-boot mailing list;
4903 email("Hi, I am new to U-Boot, how do I get started?");
4906 Read the README file in the top level directory;
4907 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4908 Read applicable doc/*.README;
4909 Read the source, Luke;
4910 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4913 if (available_money > toLocalCurrency ($2500))
4916 Add a lot of aggravation and time;
4918 if (a similar board exists) { /* hopefully... */
4919 cp -a board/<similar> board/<myboard>
4920 cp include/configs/<similar>.h include/configs/<myboard>.h
4922 Create your own board support subdirectory;
4923 Create your own board include/configs/<myboard>.h file;
4925 Edit new board/<myboard> files
4926 Edit new include/configs/<myboard>.h
4931 Add / modify source code;
4935 email("Hi, I am having problems...");
4937 Send patch file to the U-Boot email list;
4938 if (reasonable critiques)
4939 Incorporate improvements from email list code review;
4941 Defend code as written;
4947 void no_more_time (int sig)
4956 All contributions to U-Boot should conform to the Linux kernel
4957 coding style; see the file "Documentation/CodingStyle" and the script
4958 "scripts/Lindent" in your Linux kernel source directory.
4960 Source files originating from a different project (for example the
4961 MTD subsystem) are generally exempt from these guidelines and are not
4962 reformated to ease subsequent migration to newer versions of those
4965 Please note that U-Boot is implemented in C (and to some small parts in
4966 Assembler); no C++ is used, so please do not use C++ style comments (//)
4969 Please also stick to the following formatting rules:
4970 - remove any trailing white space
4971 - use TAB characters for indentation and vertical alignment, not spaces
4972 - make sure NOT to use DOS '\r\n' line feeds
4973 - do not add more than 2 consecutive empty lines to source files
4974 - do not add trailing empty lines to source files
4976 Submissions which do not conform to the standards may be returned
4977 with a request to reformat the changes.
4983 Since the number of patches for U-Boot is growing, we need to
4984 establish some rules. Submissions which do not conform to these rules
4985 may be rejected, even when they contain important and valuable stuff.
4987 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4989 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4990 see http://lists.denx.de/mailman/listinfo/u-boot
4992 When you send a patch, please include the following information with
4995 * For bug fixes: a description of the bug and how your patch fixes
4996 this bug. Please try to include a way of demonstrating that the
4997 patch actually fixes something.
4999 * For new features: a description of the feature and your
5002 * A CHANGELOG entry as plaintext (separate from the patch)
5004 * For major contributions, your entry to the CREDITS file
5006 * When you add support for a new board, don't forget to add this
5007 board to the MAINTAINERS file, too.
5009 * If your patch adds new configuration options, don't forget to
5010 document these in the README file.
5012 * The patch itself. If you are using git (which is *strongly*
5013 recommended) you can easily generate the patch using the
5014 "git format-patch". If you then use "git send-email" to send it to
5015 the U-Boot mailing list, you will avoid most of the common problems
5016 with some other mail clients.
5018 If you cannot use git, use "diff -purN OLD NEW". If your version of
5019 diff does not support these options, then get the latest version of
5022 The current directory when running this command shall be the parent
5023 directory of the U-Boot source tree (i. e. please make sure that
5024 your patch includes sufficient directory information for the
5027 We prefer patches as plain text. MIME attachments are discouraged,
5028 and compressed attachments must not be used.
5030 * If one logical set of modifications affects or creates several
5031 files, all these changes shall be submitted in a SINGLE patch file.
5033 * Changesets that contain different, unrelated modifications shall be
5034 submitted as SEPARATE patches, one patch per changeset.
5039 * Before sending the patch, run the MAKEALL script on your patched
5040 source tree and make sure that no errors or warnings are reported
5041 for any of the boards.
5043 * Keep your modifications to the necessary minimum: A patch
5044 containing several unrelated changes or arbitrary reformats will be
5045 returned with a request to re-formatting / split it.
5047 * If you modify existing code, make sure that your new code does not
5048 add to the memory footprint of the code ;-) Small is beautiful!
5049 When adding new features, these should compile conditionally only
5050 (using #ifdef), and the resulting code with the new feature
5051 disabled must not need more memory than the old code without your
5054 * Remember that there is a size limit of 100 kB per message on the
5055 u-boot mailing list. Bigger patches will be moderated. If they are
5056 reasonable and not too big, they will be acknowledged. But patches
5057 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob