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README
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README
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#
# (C) Copyright 2000 - 2012
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#
Summary:
========
This directory contains the source code for U-Boot, a boot loader for
Embedded boards based on PowerPC, ARM, MIPS and several other
processors, which can be installed in a boot ROM and used to
initialize and test the hardware or to download and run application
code.
The development of U-Boot is closely related to Linux: some parts of
the source code originate in the Linux source tree, we have some
header files in common, and special provision has been made to
support booting of Linux images.
Some attention has been paid to make this software easily
configurable and extendable. For instance, all monitor commands are
implemented with the same call interface, so that it's very easy to
add new commands. Also, instead of permanently adding rarely used
code (for instance hardware test utilities) to the monitor, you can
load and run it dynamically.
Status:
=======
In general, all boards for which a configuration option exists in the
Makefile have been tested to some extent and can be considered
"working". In fact, many of them are used in production systems.
In case of problems see the CHANGELOG and CREDITS files to find out
who contributed the specific port. The MAINTAINERS file lists board
maintainers.
Where to get help:
==================
In case you have questions about, problems with or contributions for
U-Boot you should send a message to the U-Boot mailing list at
<u-boot@lists.denx.de>. There is also an archive of previous traffic
on the mailing list - please search the archive before asking FAQ's.
Please see http://lists.denx.de/pipermail/u-boot and
http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
Where to get source code:
=========================
The U-Boot source code is maintained in the git repository at
git://www.denx.de/git/u-boot.git ; you can browse it online at
http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
The "snapshot" links on this page allow you to download tarballs of
any version you might be interested in. Official releases are also
available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
directory.
Pre-built (and tested) images are available from
ftp://ftp.denx.de/pub/u-boot/images/
Where we come from:
===================
- start from 8xxrom sources
- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
- clean up code
- make it easier to add custom boards
- make it possible to add other [PowerPC] CPUs
- extend functions, especially:
* Provide extended interface to Linux boot loader
* S-Record download
* network boot
* PCMCIA / CompactFlash / ATA disk / SCSI ... boot
- create ARMBoot project (http://sourceforge.net/projects/armboot)
- add other CPU families (starting with ARM)
- create U-Boot project (http://sourceforge.net/projects/u-boot)
- current project page: see http://www.denx.de/wiki/U-Boot
Names and Spelling:
===================
The "official" name of this project is "Das U-Boot". The spelling
"U-Boot" shall be used in all written text (documentation, comments
in source files etc.). Example:
This is the README file for the U-Boot project.
File names etc. shall be based on the string "u-boot". Examples:
include/asm-ppc/u-boot.h
#include <asm/u-boot.h>
Variable names, preprocessor constants etc. shall be either based on
the string "u_boot" or on "U_BOOT". Example:
U_BOOT_VERSION u_boot_logo
IH_OS_U_BOOT u_boot_hush_start
Versioning:
===========
Starting with the release in October 2008, the names of the releases
were changed from numerical release numbers without deeper meaning
into a time stamp based numbering. Regular releases are identified by
names consisting of the calendar year and month of the release date.
Additional fields (if present) indicate release candidates or bug fix
releases in "stable" maintenance trees.
Examples:
U-Boot v2009.11 - Release November 2009
U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
Directory Hierarchy:
====================
/arch Architecture specific files
/arm Files generic to ARM architecture
/cpu CPU specific files
/arm720t Files specific to ARM 720 CPUs
/arm920t Files specific to ARM 920 CPUs
/at91 Files specific to Atmel AT91RM9200 CPU
/imx Files specific to Freescale MC9328 i.MX CPUs
/s3c24x0 Files specific to Samsung S3C24X0 CPUs
/arm925t Files specific to ARM 925 CPUs
/arm926ejs Files specific to ARM 926 CPUs
/arm1136 Files specific to ARM 1136 CPUs
/ixp Files specific to Intel XScale IXP CPUs
/pxa Files specific to Intel XScale PXA CPUs
/s3c44b0 Files specific to Samsung S3C44B0 CPUs
/sa1100 Files specific to Intel StrongARM SA1100 CPUs
/lib Architecture specific library files
/avr32 Files generic to AVR32 architecture
/cpu CPU specific files
/lib Architecture specific library files
/blackfin Files generic to Analog Devices Blackfin architecture
/cpu CPU specific files
/lib Architecture specific library files
/x86 Files generic to x86 architecture
/cpu CPU specific files
/lib Architecture specific library files
/m68k Files generic to m68k architecture
/cpu CPU specific files
/mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
/mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
/mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
/mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
/mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
/lib Architecture specific library files
/microblaze Files generic to microblaze architecture
/cpu CPU specific files
/lib Architecture specific library files
/mips Files generic to MIPS architecture
/cpu CPU specific files
/mips32 Files specific to MIPS32 CPUs
/xburst Files specific to Ingenic XBurst CPUs
/lib Architecture specific library files
/nds32 Files generic to NDS32 architecture
/cpu CPU specific files
/n1213 Files specific to Andes Technology N1213 CPUs
/lib Architecture specific library files
/nios2 Files generic to Altera NIOS2 architecture
/cpu CPU specific files
/lib Architecture specific library files
/powerpc Files generic to PowerPC architecture
/cpu CPU specific files
/74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
/mpc5xx Files specific to Freescale MPC5xx CPUs
/mpc5xxx Files specific to Freescale MPC5xxx CPUs
/mpc8xx Files specific to Freescale MPC8xx CPUs
/mpc8220 Files specific to Freescale MPC8220 CPUs
/mpc824x Files specific to Freescale MPC824x CPUs
/mpc8260 Files specific to Freescale MPC8260 CPUs
/mpc85xx Files specific to Freescale MPC85xx CPUs
/ppc4xx Files specific to AMCC PowerPC 4xx CPUs
/lib Architecture specific library files
/sh Files generic to SH architecture
/cpu CPU specific files
/sh2 Files specific to sh2 CPUs
/sh3 Files specific to sh3 CPUs
/sh4 Files specific to sh4 CPUs
/lib Architecture specific library files
/sparc Files generic to SPARC architecture
/cpu CPU specific files
/leon2 Files specific to Gaisler LEON2 SPARC CPU
/leon3 Files specific to Gaisler LEON3 SPARC CPU
/lib Architecture specific library files
/api Machine/arch independent API for external apps
/board Board dependent files
/common Misc architecture independent functions
/disk Code for disk drive partition handling
/doc Documentation (don't expect too much)
/drivers Commonly used device drivers
/examples Example code for standalone applications, etc.
/fs Filesystem code (cramfs, ext2, jffs2, etc.)
/include Header Files
/lib Files generic to all architectures
/libfdt Library files to support flattened device trees
/lzma Library files to support LZMA decompression
/lzo Library files to support LZO decompression
/net Networking code
/post Power On Self Test
/rtc Real Time Clock drivers
/tools Tools to build S-Record or U-Boot images, etc.
Software Configuration:
=======================
Configuration is usually done using C preprocessor defines; the
rationale behind that is to avoid dead code whenever possible.
There are two classes of configuration variables:
* Configuration _OPTIONS_:
These are selectable by the user and have names beginning with
"CONFIG_".
* Configuration _SETTINGS_:
These depend on the hardware etc. and should not be meddled with if
you don't know what you're doing; they have names beginning with
"CONFIG_SYS_".
Later we will add a configuration tool - probably similar to or even
identical to what's used for the Linux kernel. Right now, we have to
do the configuration by hand, which means creating some symbolic
links and editing some configuration files. We use the TQM8xxL boards
as an example here.
Selection of Processor Architecture and Board Type:
---------------------------------------------------
For all supported boards there are ready-to-use default
configurations available; just type "make <board_name>_config".
Example: For a TQM823L module type:
cd u-boot
make TQM823L_config
For the Cogent platform, you need to specify the CPU type as well;
e.g. "make cogent_mpc8xx_config". And also configure the cogent
directory according to the instructions in cogent/README.
Configuration Options:
----------------------
Configuration depends on the combination of board and CPU type; all
such information is kept in a configuration file
"include/configs/<board_name>.h".
Example: For a TQM823L module, all configuration settings are in
"include/configs/TQM823L.h".
Many of the options are named exactly as the corresponding Linux
kernel configuration options. The intention is to make it easier to
build a config tool - later.
The following options need to be configured:
- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
Define exactly one, e.g. CONFIG_ATSTK1002
- CPU Module Type: (if CONFIG_COGENT is defined)
Define exactly one of
CONFIG_CMA286_60_OLD
--- FIXME --- not tested yet:
CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
CONFIG_CMA287_23, CONFIG_CMA287_50
- Motherboard Type: (if CONFIG_COGENT is defined)
Define exactly one of
CONFIG_CMA101, CONFIG_CMA102
- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
Define one or more of
CONFIG_CMA302
- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
Define one or more of
CONFIG_LCD_HEARTBEAT - update a character position on
the LCD display every second with
a "rotator" |\-/|\-/
- Board flavour: (if CONFIG_MPC8260ADS is defined)
CONFIG_ADSTYPE
Possible values are:
CONFIG_SYS_8260ADS - original MPC8260ADS
CONFIG_SYS_8266ADS - MPC8266ADS
CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
CONFIG_SYS_8272ADS - MPC8272ADS
- Marvell Family Member
CONFIG_SYS_MVFS - define it if you want to enable
multiple fs option at one time
for marvell soc family
- MPC824X Family Member (if CONFIG_MPC824X is defined)
Define exactly one of
CONFIG_MPC8240, CONFIG_MPC8245
- 8xx CPU Options: (if using an MPC8xx CPU)
CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
get_gclk_freq() cannot work
e.g. if there is no 32KHz
reference PIT/RTC clock
CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
or XTAL/EXTAL)
- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
CONFIG_SYS_8xx_CPUCLK_MIN
CONFIG_SYS_8xx_CPUCLK_MAX
CONFIG_8xx_CPUCLK_DEFAULT
See doc/README.MPC866
CONFIG_SYS_MEASURE_CPUCLK
Define this to measure the actual CPU clock instead
of relying on the correctness of the configured
values. Mostly useful for board bringup to make sure
the PLL is locked at the intended frequency. Note
that this requires a (stable) reference clock (32 kHz
RTC clock or CONFIG_SYS_8XX_XIN)
CONFIG_SYS_DELAYED_ICACHE
Define this option if you want to enable the
ICache only when Code runs from RAM.
- 85xx CPU Options:
CONFIG_SYS_FSL_TBCLK_DIV
Defines the core time base clock divider ratio compared to the
system clock. On most PQ3 devices this is 8, on newer QorIQ
devices it can be 16 or 32. The ratio varies from SoC to Soc.
CONFIG_SYS_FSL_PCIE_COMPAT
Defines the string to utilize when trying to match PCIe device
tree nodes for the given platform.
CONFIG_SYS_PPC_E500_DEBUG_TLB
Enables a temporary TLB entry to be used during boot to work
around limitations in e500v1 and e500v2 external debugger
support. This reduces the portions of the boot code where
breakpoints and single stepping do not work. The value of this
symbol should be set to the TLB1 entry to be used for this
purpose.
CONFIG_SYS_FSL_ERRATUM_A004510
Enables a workaround for erratum A004510. If set,
then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
Defines one or two SoC revisions (low 8 bits of SVR)
for which the A004510 workaround should be applied.
The rest of SVR is either not relevant to the decision
of whether the erratum is present (e.g. p2040 versus
p2041) or is implied by the build target, which controls
whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
See Freescale App Note 4493 for more information about
this erratum.
CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
This is the value to write into CCSR offset 0x18600
according to the A004510 workaround.
- Generic CPU options:
CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
Defines the endianess of the CPU. Implementation of those
values is arch specific.
- Intel Monahans options:
CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
Defines the Monahans run mode to oscillator
ratio. Valid values are 8, 16, 24, 31. The core
frequency is this value multiplied by 13 MHz.
CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
Defines the Monahans turbo mode to oscillator
ratio. Valid values are 1 (default if undefined) and
2. The core frequency as calculated above is multiplied
by this value.
- MIPS CPU options:
CONFIG_SYS_INIT_SP_OFFSET
Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
pointer. This is needed for the temporary stack before
relocation.
CONFIG_SYS_MIPS_CACHE_MODE
Cache operation mode for the MIPS CPU.
See also arch/mips/include/asm/mipsregs.h.
Possible values are:
CONF_CM_CACHABLE_NO_WA
CONF_CM_CACHABLE_WA
CONF_CM_UNCACHED
CONF_CM_CACHABLE_NONCOHERENT
CONF_CM_CACHABLE_CE
CONF_CM_CACHABLE_COW
CONF_CM_CACHABLE_CUW
CONF_CM_CACHABLE_ACCELERATED
CONFIG_SYS_XWAY_EBU_BOOTCFG
Special option for Lantiq XWAY SoCs for booting from NOR flash.
See also arch/mips/cpu/mips32/start.S.
CONFIG_XWAY_SWAP_BYTES
Enable compilation of tools/xway-swap-bytes needed for Lantiq
XWAY SoCs for booting from NOR flash. The U-Boot image needs to
be swapped if a flash programmer is used.
- ARM options:
CONFIG_SYS_EXCEPTION_VECTORS_HIGH
Select high exception vectors of the ARM core, e.g., do not
clear the V bit of the c1 register of CP15.
CONFIG_SYS_THUMB_BUILD
Use this flag to build U-Boot using the Thumb instruction
set for ARM architectures. Thumb instruction set provides
better code density. For ARM architectures that support
Thumb2 this flag will result in Thumb2 code generated by
GCC.
- Linux Kernel Interface:
CONFIG_CLOCKS_IN_MHZ
U-Boot stores all clock information in Hz
internally. For binary compatibility with older Linux
kernels (which expect the clocks passed in the
bd_info data to be in MHz) the environment variable
"clocks_in_mhz" can be defined so that U-Boot
converts clock data to MHZ before passing it to the
Linux kernel.
When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
"clocks_in_mhz=1" is automatically included in the
default environment.
CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
When transferring memsize parameter to linux, some versions
expect it to be in bytes, others in MB.
Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
CONFIG_OF_LIBFDT
New kernel versions are expecting firmware settings to be
passed using flattened device trees (based on open firmware
concepts).
CONFIG_OF_LIBFDT
* New libfdt-based support
* Adds the "fdt" command
* The bootm command automatically updates the fdt
OF_CPU - The proper name of the cpus node (only required for
MPC512X and MPC5xxx based boards).
OF_SOC - The proper name of the soc node (only required for
MPC512X and MPC5xxx based boards).
OF_TBCLK - The timebase frequency.
OF_STDOUT_PATH - The path to the console device
boards with QUICC Engines require OF_QE to set UCC MAC
addresses
CONFIG_OF_BOARD_SETUP
Board code has addition modification that it wants to make
to the flat device tree before handing it off to the kernel
CONFIG_OF_BOOT_CPU
This define fills in the correct boot CPU in the boot
param header, the default value is zero if undefined.
CONFIG_OF_IDE_FIXUP
U-Boot can detect if an IDE device is present or not.
If not, and this new config option is activated, U-Boot
removes the ATA node from the DTS before booting Linux,
so the Linux IDE driver does not probe the device and
crash. This is needed for buggy hardware (uc101) where
no pull down resistor is connected to the signal IDE5V_DD7.
CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
This setting is mandatory for all boards that have only one
machine type and must be used to specify the machine type
number as it appears in the ARM machine registry
(see http://www.arm.linux.org.uk/developer/machines/).
Only boards that have multiple machine types supported
in a single configuration file and the machine type is
runtime discoverable, do not have to use this setting.
- vxWorks boot parameters:
bootvx constructs a valid bootline using the following
environments variables: bootfile, ipaddr, serverip, hostname.
It loads the vxWorks image pointed bootfile.
CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
CONFIG_SYS_VXWORKS_ADD_PARAMS
Add it at the end of the bootline. E.g "u=username pw=secret"
Note: If a "bootargs" environment is defined, it will overwride
the defaults discussed just above.
- Cache Configuration:
CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
- Cache Configuration for ARM:
CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
controller
CONFIG_SYS_PL310_BASE - Physical base address of PL310
controller register space
- Serial Ports:
CONFIG_PL010_SERIAL
Define this if you want support for Amba PrimeCell PL010 UARTs.
CONFIG_PL011_SERIAL
Define this if you want support for Amba PrimeCell PL011 UARTs.
CONFIG_PL011_CLOCK
If you have Amba PrimeCell PL011 UARTs, set this variable to
the clock speed of the UARTs.
CONFIG_PL01x_PORTS
If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
define this to a list of base addresses for each (supported)
port. See e.g. include/configs/versatile.h
CONFIG_PL011_SERIAL_RLCR
Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
have separate receive and transmit line control registers. Set
this variable to initialize the extra register.
CONFIG_PL011_SERIAL_FLUSH_ON_INIT
On some platforms (e.g. U8500) U-Boot is loaded by a second stage
boot loader that has already initialized the UART. Define this
variable to flush the UART at init time.
- Console Interface:
Depending on board, define exactly one serial port
(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
console by defining CONFIG_8xx_CONS_NONE
Note: if CONFIG_8xx_CONS_NONE is defined, the serial
port routines must be defined elsewhere
(i.e. serial_init(), serial_getc(), ...)
CONFIG_CFB_CONSOLE
Enables console device for a color framebuffer. Needs following
defines (cf. smiLynxEM, i8042)
VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
(default big endian)
VIDEO_HW_RECTFILL graphic chip supports
rectangle fill
(cf. smiLynxEM)
VIDEO_HW_BITBLT graphic chip supports
bit-blit (cf. smiLynxEM)
VIDEO_VISIBLE_COLS visible pixel columns
(cols=pitch)
VIDEO_VISIBLE_ROWS visible pixel rows
VIDEO_PIXEL_SIZE bytes per pixel
VIDEO_DATA_FORMAT graphic data format
(0-5, cf. cfb_console.c)
VIDEO_FB_ADRS framebuffer address
VIDEO_KBD_INIT_FCT keyboard int fct
(i.e. i8042_kbd_init())
VIDEO_TSTC_FCT test char fct
(i.e. i8042_tstc)
VIDEO_GETC_FCT get char fct
(i.e. i8042_getc)
CONFIG_CONSOLE_CURSOR cursor drawing on/off
(requires blink timer
cf. i8042.c)
CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
CONFIG_CONSOLE_TIME display time/date info in
upper right corner
(requires CONFIG_CMD_DATE)
CONFIG_VIDEO_LOGO display Linux logo in
upper left corner
CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
linux_logo.h for logo.
Requires CONFIG_VIDEO_LOGO
CONFIG_CONSOLE_EXTRA_INFO
additional board info beside
the logo
When CONFIG_CFB_CONSOLE is defined, video console is
default i/o. Serial console can be forced with
environment 'console=serial'.
When CONFIG_SILENT_CONSOLE is defined, all console
messages (by U-Boot and Linux!) can be silenced with
the "silent" environment variable. See
doc/README.silent for more information.
- Console Baudrate:
CONFIG_BAUDRATE - in bps
Select one of the baudrates listed in
CONFIG_SYS_BAUDRATE_TABLE, see below.
CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
- Console Rx buffer length
With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
the maximum receive buffer length for the SMC.
This option is actual only for 82xx and 8xx possible.
If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
must be defined, to setup the maximum idle timeout for
the SMC.
- Pre-Console Buffer:
Prior to the console being initialised (i.e. serial UART
initialised etc) all console output is silently discarded.
Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
buffer any console messages prior to the console being
initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
bytes are output before the console is initialised, the
earlier bytes are discarded.
'Sane' compilers will generate smaller code if
CONFIG_PRE_CON_BUF_SZ is a power of 2
- Safe printf() functions
Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
the printf() functions. These are defined in
include/vsprintf.h and include snprintf(), vsnprintf() and
so on. Code size increase is approximately 300-500 bytes.
If this option is not given then these functions will
silently discard their buffer size argument - this means
you are not getting any overflow checking in this case.
- Boot Delay: CONFIG_BOOTDELAY - in seconds
Delay before automatically booting the default image;
set to -1 to disable autoboot.
set to -2 to autoboot with no delay and not check for abort
(even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
See doc/README.autoboot for these options that
work with CONFIG_BOOTDELAY. None are required.
CONFIG_BOOT_RETRY_TIME
CONFIG_BOOT_RETRY_MIN
CONFIG_AUTOBOOT_KEYED
CONFIG_AUTOBOOT_PROMPT
CONFIG_AUTOBOOT_DELAY_STR
CONFIG_AUTOBOOT_STOP_STR
CONFIG_AUTOBOOT_DELAY_STR2
CONFIG_AUTOBOOT_STOP_STR2
CONFIG_ZERO_BOOTDELAY_CHECK
CONFIG_RESET_TO_RETRY
- Autoboot Command:
CONFIG_BOOTCOMMAND
Only needed when CONFIG_BOOTDELAY is enabled;
define a command string that is automatically executed
when no character is read on the console interface
within "Boot Delay" after reset.
CONFIG_BOOTARGS
This can be used to pass arguments to the bootm
command. The value of CONFIG_BOOTARGS goes into the
environment value "bootargs".
CONFIG_RAMBOOT and CONFIG_NFSBOOT
The value of these goes into the environment as
"ramboot" and "nfsboot" respectively, and can be used
as a convenience, when switching between booting from
RAM and NFS.
- Pre-Boot Commands:
CONFIG_PREBOOT
When this option is #defined, the existence of the
environment variable "preboot" will be checked
immediately before starting the CONFIG_BOOTDELAY
countdown and/or running the auto-boot command resp.
entering interactive mode.
This feature is especially useful when "preboot" is
automatically generated or modified. For an example
see the LWMON board specific code: here "preboot" is
modified when the user holds down a certain
combination of keys on the (special) keyboard when
booting the systems
- Serial Download Echo Mode:
CONFIG_LOADS_ECHO
If defined to 1, all characters received during a
serial download (using the "loads" command) are
echoed back. This might be needed by some terminal
emulations (like "cu"), but may as well just take
time on others. This setting #define's the initial
value of the "loads_echo" environment variable.
- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
CONFIG_KGDB_BAUDRATE
Select one of the baudrates listed in
CONFIG_SYS_BAUDRATE_TABLE, see below.
- Monitor Functions:
Monitor commands can be included or excluded
from the build by using the #include files
<config_cmd_all.h> and #undef'ing unwanted
commands, or using <config_cmd_default.h>
and augmenting with additional #define's
for wanted commands.
The default command configuration includes all commands
except those marked below with a "*".
CONFIG_CMD_ASKENV * ask for env variable
CONFIG_CMD_BDI bdinfo
CONFIG_CMD_BEDBUG * Include BedBug Debugger
CONFIG_CMD_BMP * BMP support
CONFIG_CMD_BSP * Board specific commands
CONFIG_CMD_BOOTD bootd
CONFIG_CMD_CACHE * icache, dcache
CONFIG_CMD_CONSOLE coninfo
CONFIG_CMD_CRC32 * crc32
CONFIG_CMD_DATE * support for RTC, date/time...
CONFIG_CMD_DHCP * DHCP support
CONFIG_CMD_DIAG * Diagnostics
CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
CONFIG_CMD_DTT * Digital Therm and Thermostat
CONFIG_CMD_ECHO echo arguments
CONFIG_CMD_EDITENV edit env variable
CONFIG_CMD_EEPROM * EEPROM read/write support
CONFIG_CMD_ELF * bootelf, bootvx
CONFIG_CMD_EXPORTENV * export the environment
CONFIG_CMD_SAVEENV saveenv
CONFIG_CMD_FDC * Floppy Disk Support
CONFIG_CMD_FAT * FAT partition support
CONFIG_CMD_FDOS * Dos diskette Support
CONFIG_CMD_FLASH flinfo, erase, protect
CONFIG_CMD_FPGA FPGA device initialization support
CONFIG_CMD_GO * the 'go' command (exec code)
CONFIG_CMD_GREPENV * search environment
CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
CONFIG_CMD_I2C * I2C serial bus support
CONFIG_CMD_IDE * IDE harddisk support
CONFIG_CMD_IMI iminfo
CONFIG_CMD_IMLS List all found images
CONFIG_CMD_IMMAP * IMMR dump support
CONFIG_CMD_IMPORTENV * import an environment
CONFIG_CMD_INI * import data from an ini file into the env
CONFIG_CMD_IRQ * irqinfo
CONFIG_CMD_ITEST Integer/string test of 2 values
CONFIG_CMD_JFFS2 * JFFS2 Support
CONFIG_CMD_KGDB * kgdb
CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
(169.254.*.*)
CONFIG_CMD_LOADB loadb
CONFIG_CMD_LOADS loads
CONFIG_CMD_MD5SUM print md5 message digest
(requires CONFIG_CMD_MEMORY and CONFIG_MD5)
CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
loop, loopw, mtest
CONFIG_CMD_MISC Misc functions like sleep etc
CONFIG_CMD_MMC * MMC memory mapped support
CONFIG_CMD_MII * MII utility commands
CONFIG_CMD_MTDPARTS * MTD partition support
CONFIG_CMD_NAND * NAND support
CONFIG_CMD_NET bootp, tftpboot, rarpboot
CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
CONFIG_CMD_PCI * pciinfo
CONFIG_CMD_PCMCIA * PCMCIA support
CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
host
CONFIG_CMD_PORTIO * Port I/O
CONFIG_CMD_REGINFO * Register dump
CONFIG_CMD_RUN run command in env variable
CONFIG_CMD_SAVES * save S record dump
CONFIG_CMD_SCSI * SCSI Support
CONFIG_CMD_SDRAM * print SDRAM configuration information
(requires CONFIG_CMD_I2C)
CONFIG_CMD_SETGETDCR Support for DCR Register access
(4xx only)
CONFIG_CMD_SF * Read/write/erase SPI NOR flash
CONFIG_CMD_SHA1SUM print sha1 memory digest
(requires CONFIG_CMD_MEMORY)
CONFIG_CMD_SOURCE "source" command Support
CONFIG_CMD_SPI * SPI serial bus support
CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
CONFIG_CMD_TFTPPUT * TFTP put command (upload)
CONFIG_CMD_TIME * run command and report execution time (ARM specific)
CONFIG_CMD_TIMER * access to the system tick timer
CONFIG_CMD_USB * USB support
CONFIG_CMD_CDP * Cisco Discover Protocol support
CONFIG_CMD_MFSL * Microblaze FSL support
EXAMPLE: If you want all functions except of network
support you can write:
#include "config_cmd_all.h"
#undef CONFIG_CMD_NET
Other Commands:
fdt (flattened device tree) command: CONFIG_OF_LIBFDT
Note: Don't enable the "icache" and "dcache" commands
(configuration option CONFIG_CMD_CACHE) unless you know
what you (and your U-Boot users) are doing. Data
cache cannot be enabled on systems like the 8xx or
8260 (where accesses to the IMMR region must be
uncached), and it cannot be disabled on all other
systems where we (mis-) use the data cache to hold an
initial stack and some data.
XXX - this list needs to get updated!
- Device tree:
CONFIG_OF_CONTROL
If this variable is defined, U-Boot will use a device tree
to configure its devices, instead of relying on statically
compiled #defines in the board file. This option is
experimental and only available on a few boards. The device
tree is available in the global data as gd->fdt_blob.
U-Boot needs to get its device tree from somewhere. This can
be done using one of the two options below:
CONFIG_OF_EMBED
If this variable is defined, U-Boot will embed a device tree
binary in its image. This device tree file should be in the
board directory and called <soc>-<board>.dts. The binary file
is then picked up in board_init_f() and made available through
the global data structure as gd->blob.
CONFIG_OF_SEPARATE
If this variable is defined, U-Boot will build a device tree
binary. It will be called u-boot.dtb. Architecture-specific
code will locate it at run-time. Generally this works by:
cat u-boot.bin u-boot.dtb >image.bin
and in fact, U-Boot does this for you, creating a file called
u-boot-dtb.bin which is useful in the common case. You can
still use the individual files if you need something more
exotic.
- Watchdog:
CONFIG_WATCHDOG
If this variable is defined, it enables watchdog
support for the SoC. There must be support in the SoC
specific code for a watchdog. For the 8xx and 8260
CPUs, the SIU Watchdog feature is enabled in the SYPCR
register. When supported for a specific SoC is
available, then no further board specific code should
be needed to use it.
CONFIG_HW_WATCHDOG
When using a watchdog circuitry external to the used
SoC, then define this variable and provide board
specific code for the "hw_watchdog_reset" function.
- U-Boot Version:
CONFIG_VERSION_VARIABLE
If this variable is defined, an environment variable
named "ver" is created by U-Boot showing the U-Boot
version as printed by the "version" command.
Any change to this variable will be reverted at the
next reset.
- Real-Time Clock:
When CONFIG_CMD_DATE is selected, the type of the RTC
has to be selected, too. Define exactly one of the
following options:
CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
CONFIG_RTC_MC146818 - use MC146818 RTC
CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
CONFIG_RTC_DS164x - use Dallas DS164x RTC
CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
CONFIG_SYS_RV3029_TCR - enable trickle charger on
RV3029 RTC.
Note that if the RTC uses I2C, then the I2C interface
must also be configured. See I2C Support, below.
- GPIO Support:
CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
CONFIG_PCA953X_INFO - enable pca953x info command
The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
chip-ngpio pairs that tell the PCA953X driver the number of
pins supported by a particular chip.
Note that if the GPIO device uses I2C, then the I2C interface
must also be configured. See I2C Support, below.
- Timestamp Support:
When CONFIG_TIMESTAMP is selected, the timestamp
(date and time) of an image is printed by image
commands like bootm or iminfo. This option is
automatically enabled when you select CONFIG_CMD_DATE .
- Partition Labels (disklabels) Supported:
Zero or more of the following:
CONFIG_MAC_PARTITION Apple's MacOS partition table.
CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
Intel architecture, USB sticks, etc.
CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
bootloader. Note 2TB partition limit; see
disk/part_efi.c
CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
CONFIG_CMD_SCSI) you must configure support for at
least one non-MTD partition type as well.
- IDE Reset method:
CONFIG_IDE_RESET_ROUTINE - this is defined in several
board configurations files but used nowhere!