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#
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# (C) Copyright 2000 - 2011
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# 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:
========

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This directory contains the source code for U-Boot, a boot loader for
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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.
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The development of U-Boot is closely related to Linux: some parts of
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the source code originate in the Linux source tree, we have some
header files in common, and special provision has been made to
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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
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Makefile have been tested to some extent and can be considered
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"working". In fact, many of them are used in production systems.

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In case of problems see the CHANGELOG and CREDITS files to find out
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who contributed the specific port. The MAINTAINERS file lists board
maintainers.
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Where to get help:
==================

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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
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<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
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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
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any version you might be interested in. Official releases are also
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available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
directory.

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Pre-built (and tested) images are available from
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ftp://ftp.denx.de/pub/u-boot/images/


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Where we come from:
===================

- start from 8xxrom sources
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- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
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- 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
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  * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
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- create ARMBoot project (http://sourceforge.net/projects/armboot)
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- add other CPU families (starting with ARM)
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- create U-Boot project (http://sourceforge.net/projects/u-boot)
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- current project page: see http://www.denx.de/wiki/U-Boot
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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
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Versioning:
===========

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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
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Directory Hierarchy:
====================

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/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
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	/at91rm9200	Files specific to Atmel AT91RM9200 CPU
	/imx		Files specific to Freescale MC9328 i.MX CPUs
	/s3c24x0	Files specific to Samsung S3C24X0 CPUs
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      /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
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  /x86			Files generic to x86 architecture
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    /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
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      /mips32		Files specific to MIPS32 CPUs
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    /lib		Architecture specific library files
  /nios2		Files generic to Altera NIOS2 architecture
    /cpu		CPU specific files
    /lib		Architecture specific library files
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  /powerpc		Files generic to PowerPC architecture
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    /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.
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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
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  "CONFIG_SYS_".
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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

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For the Cogent platform, you need to specify the CPU type as well;
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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".


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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.


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The following options need to be configured:

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- CPU Type:	Define exactly one, e.g. CONFIG_MPC85XX.

- Board Type:	Define exactly one, e.g. CONFIG_MPC8540ADS.
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- CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
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		Define exactly one, e.g. CONFIG_ATSTK1002
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- 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
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					  the LCD display every second with
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					  a "rotator" |\-/|\-/

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- Board flavour: (if CONFIG_MPC8260ADS is defined)
		CONFIG_ADSTYPE
		Possible values are:
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			CONFIG_SYS_8260ADS	- original MPC8260ADS
			CONFIG_SYS_8266ADS	- MPC8266ADS
			CONFIG_SYS_PQ2FADS	- PQ2FADS-ZU or PQ2FADS-VR
			CONFIG_SYS_8272ADS	- MPC8272ADS
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- Marvell Family Member
		CONFIG_SYS_MVFS		- define it if you want to enable
					  multiple fs option at one time
					  for marvell soc family

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- MPC824X Family Member (if CONFIG_MPC824X is defined)
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		Define exactly one of
		CONFIG_MPC8240, CONFIG_MPC8245
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- 8xx CPU Options: (if using an MPC8xx CPU)
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		CONFIG_8xx_GCLK_FREQ	- deprecated: CPU clock if
					  get_gclk_freq() cannot work
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					  e.g. if there is no 32KHz
					  reference PIT/RTC clock
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		CONFIG_8xx_OSCLK	- PLL input clock (either EXTCLK
					  or XTAL/EXTAL)
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- 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
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		CONFIG_SYS_8xx_CPUCLK_MIN
		CONFIG_SYS_8xx_CPUCLK_MAX
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		CONFIG_8xx_CPUCLK_DEFAULT
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			See doc/README.MPC866

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		CONFIG_SYS_MEASURE_CPUCLK
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		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
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		RTC clock or CONFIG_SYS_8XX_XIN)
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		CONFIG_SYS_DELAYED_ICACHE

		Define this option if you want to enable the
		ICache only when Code runs from RAM.

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- 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.

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		CONFIG_SYS_FSL_PCIE_COMPAT

		Defines the string to utilize when trying to match PCIe device
		tree nodes for the given platform.

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- Intel Monahans options:
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		CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
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		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.

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		CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
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		Defines the Monahans turbo mode to oscillator
		ratio. Valid values are 1 (default if undefined) and
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		2. The core frequency as calculated above is multiplied
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		by this value.
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- 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.

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- Linux Kernel Interface:
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		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
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		"clocks_in_mhz=1" is automatically included in the
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		default environment.

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		CONFIG_MEMSIZE_IN_BYTES		[relevant for MIPS only]

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		When transferring memsize parameter to linux, some versions
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		expect it to be in bytes, others in MB.
		Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.

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		CONFIG_OF_LIBFDT
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		New kernel versions are expecting firmware settings to be
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		passed using flattened device trees (based on open firmware
		concepts).

		CONFIG_OF_LIBFDT
		 * New libfdt-based support
		 * Adds the "fdt" command
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		 * The bootm command automatically updates the fdt
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		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).
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		OF_TBCLK - The timebase frequency.
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		OF_STDOUT_PATH - The path to the console device
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		boards with QUICC Engines require OF_QE to set UCC MAC
		addresses
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		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
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		CONFIG_OF_BOOT_CPU

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		This define fills in the correct boot CPU in the boot
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		param header, the default value is zero if undefined.

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		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.

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		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.

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- 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.

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- 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

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- 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

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- Serial Ports:
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		CONFIG_PL010_SERIAL
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		Define this if you want support for Amba PrimeCell PL010 UARTs.

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		CONFIG_PL011_SERIAL
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		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

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		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.

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- Console Interface:
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		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
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		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, board/eltec/bab7xx)
			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)
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			VIDEO_VISIBLE_ROWS	visible pixel rows
			VIDEO_PIXEL_SIZE	bytes per pixel
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			VIDEO_DATA_FORMAT	graphic data format
						(0-5, cf. cfb_console.c)
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			VIDEO_FB_ADRS		framebuffer address
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			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)
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			CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
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			CONFIG_CONSOLE_TIME	display time/date info in
						upper right corner
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						(requires CONFIG_CMD_DATE)
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			CONFIG_VIDEO_LOGO	display Linux logo in
						upper left corner
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			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
						linux_logo.h for logo.
						Requires CONFIG_VIDEO_LOGO
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			CONFIG_CONSOLE_EXTRA_INFO
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						additional board info beside
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						the logo

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		When CONFIG_CFB_CONSOLE is defined, video console is
		default i/o. Serial console can be forced with
		environment 'console=serial'.
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		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.
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- Console Baudrate:
		CONFIG_BAUDRATE - in bps
		Select one of the baudrates listed in
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		CONFIG_SYS_BAUDRATE_TABLE, see below.
		CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
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- Console Rx buffer length
		With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
		the maximum receive buffer length for the SMC.
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		This option is actual only for 82xx and 8xx possible.
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		If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
		must be defined, to setup the maximum idle timeout for
		the SMC.

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- Boot Delay:	CONFIG_BOOTDELAY - in seconds
		Delay before automatically booting the default image;
		set to -1 to disable autoboot.

		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
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		This can be used to pass arguments to the bootm
		command. The value of CONFIG_BOOTARGS goes into the
		environment value "bootargs".
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		CONFIG_RAMBOOT and CONFIG_NFSBOOT
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		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
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		RAM and NFS.
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- 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.

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- Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
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		CONFIG_KGDB_BAUDRATE
		Select one of the baudrates listed in
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		CONFIG_SYS_BAUDRATE_TABLE, see below.
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- Monitor Functions:
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		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
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		CONFIG_CMD_CRC32	* crc32
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		CONFIG_CMD_DATE		* support for RTC, date/time...
		CONFIG_CMD_DHCP		* DHCP support
		CONFIG_CMD_DIAG		* Diagnostics
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		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
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		CONFIG_CMD_DTT		* Digital Therm and Thermostat
		CONFIG_CMD_ECHO		  echo arguments
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		CONFIG_CMD_EDITENV	  edit env variable
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		CONFIG_CMD_EEPROM	* EEPROM read/write support
		CONFIG_CMD_ELF		* bootelf, bootvx
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		CONFIG_CMD_EXPORTENV	* export the environment
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		CONFIG_CMD_SAVEENV	  saveenv
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		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
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		CONFIG_CMD_GO		* the 'go' command (exec code)
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		CONFIG_CMD_GREPENV	* search environment
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		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
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		CONFIG_CMD_IMPORTENV	* import an environment
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		CONFIG_CMD_IRQ		* irqinfo
		CONFIG_CMD_ITEST	  Integer/string test of 2 values
		CONFIG_CMD_JFFS2	* JFFS2 Support
		CONFIG_CMD_KGDB		* kgdb
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		CONFIG_CMD_LDRINFO	  ldrinfo (display Blackfin loader)
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		CONFIG_CMD_LOADB	  loadb
		CONFIG_CMD_LOADS	  loads
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		CONFIG_CMD_MD5SUM	  print md5 message digest
					  (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
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		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
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		CONFIG_CMD_MTDPARTS	* MTD partition support
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		CONFIG_CMD_NAND		* NAND support
		CONFIG_CMD_NET		  bootp, tftpboot, rarpboot
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		CONFIG_CMD_PCA953X	* PCA953x I2C gpio commands
		CONFIG_CMD_PCA953X_INFO	* PCA953x I2C gpio info command
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		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)
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		CONFIG_CMD_SHA1SUM	  print sha1 memory digest
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					  (requires CONFIG_CMD_MEMORY)
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		CONFIG_CMD_SOURCE	  "source" command Support
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		CONFIG_CMD_SPI		* SPI serial bus support
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		CONFIG_CMD_TFTPSRV	* TFTP transfer in server mode
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		CONFIG_CMD_USB		* USB support
		CONFIG_CMD_CDP		* Cisco Discover Protocol support
		CONFIG_CMD_FSL		* Microblaze FSL support

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		EXAMPLE: If you want all functions except of network
		support you can write:

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		#include "config_cmd_all.h"
		#undef CONFIG_CMD_NET
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	Other Commands:
		fdt (flattened device tree) command: CONFIG_OF_LIBFDT
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	Note:	Don't enable the "icache" and "dcache" commands
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		(configuration option CONFIG_CMD_CACHE) unless you know
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		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.
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		XXX - this list needs to get updated!

- Watchdog:
		CONFIG_WATCHDOG
		If this variable is defined, it enables watchdog
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		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.
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- 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.
		This variable is readonly.

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- Real-Time Clock:

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		When CONFIG_CMD_DATE is selected, the type of the RTC
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		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
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		CONFIG_RTC_MC13783	- use MC13783 RTC
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		CONFIG_RTC_MC146818	- use MC146818 RTC
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		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
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		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
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		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
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		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
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		CONFIG_RTC_ISL1208	- use Intersil ISL1208 RTC
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		CONFIG_RTC_MAX6900	- use Maxim, Inc. MAX6900 RTC
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		CONFIG_SYS_RTC_DS1337_NOOSC	- Turn off the OSC output for DS1337
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		CONFIG_SYS_RV3029_TCR	- enable trickle charger on
					  RV3029 RTC.
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		Note that if the RTC uses I2C, then the I2C interface
		must also be configured. See I2C Support, below.

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- GPIO Support:
		CONFIG_PCA953X		- use NXP's PCA953X series I2C GPIO
		CONFIG_PCA953X_INFO	- enable pca953x info command

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		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.

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		Note that if the GPIO device uses I2C, then the I2C interface
		must also be configured. See I2C Support, below.

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- Timestamp Support:

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		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
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		automatically enabled when you select CONFIG_CMD_DATE .
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- Partition Support:
		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
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		and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
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		If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
		CONFIG_CMD_SCSI) you must configure support for at
		least one partition type as well.
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- IDE Reset method:
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		CONFIG_IDE_RESET_ROUTINE - this is defined in several
		board configurations files but used nowhere!
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		CONFIG_IDE_RESET - is this is defined, IDE Reset will
		be performed by calling the function
			ide_set_reset(int reset)
		which has to be defined in a board specific file
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- ATAPI Support:
		CONFIG_ATAPI

		Set this to enable ATAPI support.

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- LBA48 Support
		CONFIG_LBA48

		Set this to enable support for disks larger than 137GB
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		Also look at CONFIG_SYS_64BIT_LBA.
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		Whithout these , LBA48 support uses 32bit variables and will 'only'
		support disks up to 2.1TB.

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		CONFIG_SYS_64BIT_LBA:
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			When enabled, makes the IDE subsystem use 64bit sector addresses.
			Default is 32bit.

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- SCSI Support:
		At the moment only there is only support for the
		SYM53C8XX SCSI controller; define
		CONFIG_SCSI_SYM53C8XX to enable it.

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		CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
		CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
		CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
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		maximum numbers of LUNs, SCSI ID's and target
		devices.
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		CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
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- NETWORK Support (PCI):
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		CONFIG_E1000
		Support for Intel 8254x gigabit chips.
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		CONFIG_E1000_FALLBACK_MAC
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		default MAC for empty EEPROM after production.
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		CONFIG_EEPRO100
		Support for Intel 82557/82559/82559ER chips.
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		Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
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		write routine for first time initialisation.

		CONFIG_TULIP
		Support for Digital 2114x chips.
		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
		modem chip initialisation (KS8761/QS6611).

		CONFIG_NATSEMI
		Support for National dp83815 chips.

		CONFIG_NS8382X
		Support for National dp8382[01] gigabit chips.

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- NETWORK Support (other):

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		CONFIG_DRIVER_AT91EMAC
		Support for AT91RM9200 EMAC.

			CONFIG_RMII
			Define this to use reduced MII inteface

			CONFIG_DRIVER_AT91EMAC_QUIET
			If this defined, the driver is quiet.
			The driver doen't show link status messages.

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		CONFIG_DRIVER_LAN91C96
		Support for SMSC's LAN91C96 chips.

			CONFIG_LAN91C96_BASE
			Define this to hold the physical address
			of the LAN91C96's I/O space

			CONFIG_LAN91C96_USE_32_BIT
			Define this to enable 32 bit addressing

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		CONFIG_DRIVER_SMC91111
		Support for SMSC's LAN91C111 chip

			CONFIG_SMC91111_BASE
			Define this to hold the physical address
			of the device (I/O space)

			CONFIG_SMC_USE_32_BIT
			Define this if data bus is 32 bits

			CONFIG_SMC_USE_IOFUNCS
			Define this to use i/o functions instead of macros
			(some hardware wont work with macros)

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		CONFIG_FTGMAC100
		Support for Faraday's FTGMAC100 Gigabit SoC Ethernet

			CONFIG_FTGMAC100_EGIGA
			Define this to use GE link update with gigabit PHY.
			Define this if FTGMAC100 is connected to gigabit PHY.
			If your system has 10/100 PHY only, it might not occur
			wrong behavior. Because PHY usually return timeout or
			useless data when polling gigabit status and gigabit
			control registers. This behavior won't affect the
			correctnessof 10/100 link speed update.

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		CONFIG_SMC911X
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		Support for SMSC's LAN911x and LAN921x chips

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			CONFIG_SMC911X_BASE
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			Define this to hold the physical address
			of the device (I/O space)

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			CONFIG_SMC911X_32_BIT
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			Define this if data bus is 32 bits

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			CONFIG_SMC911X_16_BIT
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			Define this if data bus is 16 bits. If your processor
			automatically converts one 32 bit word to two 16 bit
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			words you may also try CONFIG_SMC911X_32_BIT.
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		CONFIG_SH_ETHER
		Support for Renesas on-chip Ethernet controller

			CONFIG_SH_ETHER_USE_PORT
			Define the number of ports to be used

			CONFIG_SH_ETHER_PHY_ADDR
			Define the ETH PHY's address

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			CONFIG_SH_ETHER_CACHE_WRITEBACK
			If this option is set, the driver enables cache flush.

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- USB Support:
		At the moment only the UHCI host controller is
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		supported (PIP405, MIP405, MPC5200); define
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		CONFIG_USB_UHCI to enable it.
		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
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		and define CONFIG_USB_STORAGE to enable the USB
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		storage devices.
		Note:
		Supported are USB Keyboards and USB Floppy drives
		(TEAC FD-05PUB).
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		MPC5200 USB requires additional defines:
			CONFIG_USB_CLOCK
				for 528 MHz Clock: 0x0001bbbb
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			CONFIG_PSC3_USB
				for USB on PSC3
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			CONFIG_USB_CONFIG
				for differential drivers: 0x00001000
				for single ended drivers: 0x00005000
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				for differential drivers on PSC3: 0x00000100
				for single ended drivers on PSC3: 0x00004100
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			CONFIG_SYS_USB_EVENT_POLL
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				May be defined to allow interrupt polling
				instead of using asynchronous interrupts
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- USB Device:
		Define the below if you wish to use the USB console.
		Once firmware is rebuilt from a serial console issue the
		command "setenv stdin usbtty; setenv stdout usbtty" and
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		attach your USB cable. The Unix command "dmesg" should print
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		it has found a new device. The environment variable usbtty
		can be set to gserial or cdc_acm to enable your device to
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		appear to a USB host as a Linux gserial device or a
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		Common Device Class Abstract Control Model serial device.
		If you select usbtty = gserial you should be able to enumerate
		a Linux host by
		# modprobe usbserial vendor=0xVendorID product=0xProductID
		else if using cdc_acm, simply setting the environment
		variable usbtty to be cdc_acm should suffice. The following
		might be defined in YourBoardName.h
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			CONFIG_USB_DEVICE
			Define this to build a UDC device

			CONFIG_USB_TTY
			Define this to have a tty type of device available to
			talk to the UDC device
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			CONFIG_SYS_CONSOLE_IS_IN_ENV
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			Define this if you want stdin, stdout &/or stderr to
			be set to usbtty.

			mpc8xx:
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				CONFIG_SYS_USB_EXTC_CLK 0xBLAH
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				Derive USB clock from external clock "blah"
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				- CONFIG_SYS_USB_EXTC_CLK 0x02
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				CONFIG_SYS_USB_BRG_CLK 0xBLAH
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				Derive USB clock from brgclk
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				- CONFIG_SYS_USB_BRG_CLK 0x04
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		If you have a USB-IF assigned VendorID then you may wish to
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		define your own vendor specific values either in BoardName.h
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		or directly in usbd_vendor_info.h. If you don't define
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		CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
		CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
		should pretend to be a Linux device to it's target host.

			CONFIG_USBD_MANUFACTURER
			Define this string as the name of your company for
			- CONFIG_USBD_MANUFACTURER "my company"
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			CONFIG_USBD_PRODUCT_NAME
			Define this string as the name of your product
			- CONFIG_USBD_PRODUCT_NAME "acme usb device"

			CONFIG_USBD_VENDORID
			Define this as your assigned Vendor ID from the USB
			Implementors Forum. This *must* be a genuine Vendor ID
			to avoid polluting the USB namespace.
			- CONFIG_USBD_VENDORID 0xFFFF
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			CONFIG_USBD_PRODUCTID
			Define this as the unique Product ID
			for your device
			- CONFIG_USBD_PRODUCTID 0xFFFF
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- MMC Support:
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		The MMC controller on the Intel PXA is supported. To
		enable this define CONFIG_MMC. The MMC can be
		accessed from the boot prompt by mapping the device
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		to physical memory similar to flash. Command line is
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		enabled with CONFIG_CMD_MMC. The MMC driver also works with
		the FAT fs. This is enabled with CONFIG_CMD_FAT.
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		CONFIG_SH_MMCIF
		Support for Renesas on-chip MMCIF controller

			CONFIG_SH_MMCIF_ADDR
			Define the base address of MMCIF registers

			CONFIG_SH_MMCIF_CLK
			Define the clock frequency for MMCIF

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- Journaling Flash filesystem support:
		CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
		CONFIG_JFFS2_NAND_DEV
		Define these for a default partition on a NAND device

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		CONFIG_SYS_JFFS2_FIRST_SECTOR,
		CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
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		Define these for a default partition on a NOR device

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		CONFIG_SYS_JFFS_CUSTOM_PART
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		Define this to create an own partition. You have to provide a
		function struct part_info* jffs2_part_info(int part_num)

		If you define only one JFFS2 partition you may also want to
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		#define CONFIG_SYS_JFFS_SINGLE_PART	1
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		to disable the command chpart. This is the default when you
		have not defined a custom partition

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- Keyboard Support:
		CONFIG_ISA_KEYBOARD

		Define this to enable standard (PC-Style) keyboard
		support

		CONFIG_I8042_KBD
		Standard PC keyboard driver with US (is default) and
		GERMAN key layout (switch via environment 'keymap=de') support.
		Export function i8042_kbd_init, i8042_tstc and i8042_getc
		for cfb_console. Supports cursor blinking.

- Video support:
		CONFIG_VIDEO

		Define this to enable video support (for output to
		video).

		CONFIG_VIDEO_CT69000

		Enable Chips & Technologies 69000 Video chip

		CONFIG_VIDEO_SMI_LYNXEM
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		Enable Silicon Motion SMI 712/710/810 Video chip. The
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		video output is selected via environment 'videoout'
		(1 = LCD and 2 = CRT). If videoout is undefined, CRT is
		assumed.

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		For the CT69000 and SMI_LYNXEM drivers, videomode is
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		selected via environment 'videomode'. Two different ways
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		are possible:
		- "videomode=num"   'num' is a standard LiLo mode numbers.
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		Following standard modes are supported	(* is default):
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		      Colors	640x480 800x600 1024x768 1152x864 1280x1024
		-------------+---------------------------------------------
		      8 bits |	0x301*	0x303	 0x305	  0x161	    0x307
		     15 bits |	0x310	0x313	 0x316	  0x162	    0x319
		     16 bits |	0x311	0x314	 0x317	  0x163	    0x31A
		     24 bits |	0x312	0x315	 0x318	    ?	    0x31B
		-------------+---------------------------------------------
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		(i.e. setenv videomode 317; saveenv; reset;)

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		- "videomode=bootargs" all the video parameters are parsed
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		from the bootargs. (See drivers/video/videomodes.c)
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		CONFIG_VIDEO_SED13806
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		Enable Epson SED13806 driver. This driver supports 8bpp
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		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
		or CONFIG_VIDEO_SED13806_16BPP

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		CONFIG_FSL_DIU_FB
		Enable the Freescale DIU video driver.  Reference boards for
		SOCs that have a DIU should define this macro to enable DIU
		support, and should also define these other macros:

			CONFIG_SYS_DIU_ADDR
			CONFIG_VIDEO
			CONFIG_CMD_BMP
			CONFIG_CFB_CONSOLE
			CONFIG_VIDEO_SW_CURSOR
			CONFIG_VGA_AS_SINGLE_DEVICE
			CONFIG_VIDEO_LOGO
			CONFIG_VIDEO_BMP_LOGO

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		The DIU driver will look for the 'video-mode' environment
		variable, and if defined, enable the DIU as a console during
		boot.  See the documentation file README.video for a
		description of this variable.
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- Keyboard Support:
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		CONFIG_KEYBOARD
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		Define this to enable a custom keyboard support.
		This simply calls drv_keyboard_init() which must be
		defined in your board-specific files.
		The only board using this so far is RBC823.
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- LCD Support:	CONFIG_LCD

		Define this to enable LCD support (for output to LCD
		display); also select one of the supported displays
		by defining one of these:

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		CONFIG_ATMEL_LCD:

			HITACHI TX09D70VM1CCA, 3.5", 240x320.

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		CONFIG_NEC_NL6448AC33:
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			NEC NL6448AC33-18. Active, color, single scan.
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		CONFIG_NEC_NL6448BC20
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			NEC NL6448BC20-08. 6.5", 640x480.
			Active, color, single scan.

		CONFIG_NEC_NL6448BC33_54

			NEC NL6448BC33-54. 10.4", 640x480.
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			Active, color, single scan.

		CONFIG_SHARP_16x9

			Sharp 320x240. Active, color, single scan.
			It isn't 16x9, and I am not sure what it is.

		CONFIG_SHARP_LQ64D341

			Sharp LQ64D341 display, 640x480.
			Active, color, single scan.

		CONFIG_HLD1045

			HLD1045 display, 640x480.
			Active, color, single scan.

		CONFIG_OPTREX_BW

			Optrex	 CBL50840-2 NF-FW 99 22 M5
			or
			Hitachi	 LMG6912RPFC-00T
			or
			Hitachi	 SP14Q002

			320x240. Black & white.

		Normally display is black on white background; define
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		CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
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- Splash Screen Support: CONFIG_SPLASH_SCREEN
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		If this option is set, the environment is checked for
		a variable "splashimage". If found, the usual display
		of logo, copyright and system information on the LCD
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		is suppressed and the BMP image at the address
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		specified in "splashimage" is loaded instead. The
		console is redirected to the "nulldev", too. This
		allows for a "silent" boot where a splash screen is
		loaded very quickly after power-on.
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		CONFIG_SPLASH_SCREEN_ALIGN

		If this option is set the splash image can be freely positioned
		on the screen. Environment variable "splashpos" specifies the
		position as "x,y". If a positive number is given it is used as
		number of pixel from left/top. If a negative number is given it
		is used as number of pixel from right/bottom. You can also
		specify 'm' for centering the image.

		Example:
		setenv splashpos m,m
			=> image at center of screen

		setenv splashpos 30,20
			=> image at x = 30 and y = 20

		setenv splashpos -10,m
			=> vertically centered image
			   at x = dspWidth - bmpWidth - 9

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- Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP

		If this option is set, additionally to standard BMP
		images, gzipped BMP images can be displayed via the
		splashscreen support or the bmp command.

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- Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8

		If this option is set, 8-bit RLE compressed BMP images
		can be displayed via the splashscreen support or the
		bmp command.

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- Compression support:
		CONFIG_BZIP2

		If this option is set, support for bzip2 compressed
		images is included. If not, only uncompressed and gzip
		compressed images are supported.

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		the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
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		CONFIG_LZMA

		If this option is set, support for lzma compressed
		images is included.

		Note: The LZMA algorithm adds between 2 and 4KB of code and it
		requires an amount of dynamic memory that is given by the
		formula:

			(1846 + 768 << (lc + lp)) * sizeof(uint16)

		Where lc and lp stand for, respectively, Literal context bits
		and Literal pos bits.

		This value is upper-bounded by 14MB in the worst case. Anyway,
		for a ~4MB large kernel image, we have lc=3 and lp=0 for a
		total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
		a very small buffer.

		Use the lzmainfo tool to determinate the lc and lp values and
		then calculate the amount of needed dynamic memory (ensuring
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		the appropriate CONFIG_SYS_MALLOC_LEN value).
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- MII/PHY support:
		CONFIG_PHY_ADDR

		The address of PHY on MII bus.

		CONFIG_PHY_CLOCK_FREQ (ppc4xx)

		The clock frequency of the MII bus

		CONFIG_PHY_GIGE

		If this option is set, support for speed/duplex
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		detection of gigabit PHY is included.
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		CONFIG_PHY_RESET_DELAY

		Some PHY like Intel LXT971A need extra delay after
		reset before any MII register access is possible.
		For such PHY, set this option to the usec delay
		required. (minimum 300usec for LXT971A)

		CONFIG_PHY_CMD_DELAY (ppc4xx)

		Some PHY like Intel LXT971A need extra delay after
		command issued before MII status register can be read

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- Ethernet address:
		CONFIG_ETHADDR
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		CONFIG_ETH1ADDR
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		CONFIG_ETH2ADDR
		CONFIG_ETH3ADDR
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		CONFIG_ETH4ADDR
		CONFIG_ETH5ADDR
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		Define a default value for Ethernet address to use
		for the respective Ethernet interface, in case this
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		is not determined automatically.

- IP address:
		CONFIG_IPADDR

		Define a default value for the IP address to use for
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		the default Ethernet interface, in case this is not
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		determined through e.g. bootp.

- Server IP address:
		CONFIG_SERVERIP

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		server to contact when using the "tftboot" command.

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		CONFIG_KEEP_SERVERADDR

		Keeps the server's MAC address, in the env 'serveraddr'
		for passing to bootargs (like Linux's netconsole option)

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- Multicast TFTP Mode:
		CONFIG_MCAST_TFTP

		Defines whether you want to support multicast TFTP as per
		rfc-2090; for example to work with atftp.  Lets lots of targets
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		tftp down the same boot image concurrently.  Note: the Ethernet
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		driver in use must provide a function: mcast() to join/leave a
		multicast group.

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- BOOTP Recovery Mode:
		CONFIG_BOOTP_RANDOM_DELAY

		If you have many targets in a network that try to
		boot using BOOTP, you may want to avoid that all
		systems send out BOOTP requests at precisely the same
		moment (which would happen for instance at recovery
		from a power failure, when all systems will try to
		boot, thus flooding the BOOTP server. Defining
		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
		inserted before sending out BOOTP requests. The
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		following delays are inserted then:
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		1st BOOTP request:	delay 0 ... 1 sec
		2nd BOOTP request:	delay 0 ... 2 sec
		3rd BOOTP request:	delay 0 ... 4 sec
		4th and following
		BOOTP requests:		delay 0 ... 8 sec

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- DHCP Advanced Options:
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		You can fine tune the DHCP functionality by defining
		CONFIG_BOOTP_* symbols:

		CONFIG_BOOTP_SUBNETMASK
		CONFIG_BOOTP_GATEWAY
		CONFIG_BOOTP_HOSTNAME
		CONFIG_BOOTP_NISDOMAIN
		CONFIG_BOOTP_BOOTPATH
		CONFIG_BOOTP_BOOTFILESIZE
		CONFIG_BOOTP_DNS
		CONFIG_BOOTP_DNS2
		CONFIG_BOOTP_SEND_HOSTNAME
		CONFIG_BOOTP_NTPSERVER
		CONFIG_BOOTP_TIMEOFFSET
		CONFIG_BOOTP_VENDOREX
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		CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
		environment variable, not the BOOTP server.
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		CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
		serverip from a DHCP server, it is possible that more
		than one DNS serverip is offered to the client.
		If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
		serverip will be stored in the additional environment
		variable "dnsip2". The first DNS serverip is always
		stored in the variable "dnsip", when CONFIG_BOOTP_DNS
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		CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
		to do a dynamic update of a DNS server. To do this, they
		need the hostname of the DHCP requester.
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		If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
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		of the "hostname" environment variable is passed as
		option 12 to the DHCP server.
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		CONFIG_BOOTP_DHCP_REQUEST_DELAY

		A 32bit value in microseconds for a delay between
		receiving a "DHCP Offer" and sending the "DHCP Request".
		This fixes a problem with certain DHCP servers that don't
		respond 100% of the time to a "DHCP request". E.g. On an
		AT91RM9200 processor running at 180MHz, this delay needed
		to be *at least* 15,000 usec before a Windows Server 2003
		DHCP server would reply 100% of the time. I recommend at
		least 50,000 usec to be safe. The alternative is to hope
		that one of the retries will be successful but note that
		the DHCP timeout and retry process takes a longer than
		this delay.

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 - CDP Options:
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		CONFIG_CDP_DEVICE_ID
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		The device id used in CDP trigger frames.

		CONFIG_CDP_DEVICE_ID_PREFIX

		A two character string which is prefixed to the MAC address
		of the device.

		CONFIG_CDP_PORT_ID

		A printf format string which contains the ascii name of
		the port. Normally is set to "eth%d" which sets
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		eth0 for the first Ethernet, eth1 for the second etc.
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		CONFIG_CDP_CAPABILITIES

		A 32bit integer which indicates the device capabilities;
		0x00000010 for a normal host which does not forwards.

		CONFIG_CDP_VERSION

		An ascii string containing the version of the software.

		CONFIG_CDP_PLATFORM

		An ascii string containing the name of the platform.

		CONFIG_CDP_TRIGGER

		A 32bit integer sent on the trigger.

		CONFIG_CDP_POWER_CONSUMPTION

		A 16bit integer containing the power consumption of the
		device in .1 of milliwatts.

		CONFIG_CDP_APPLIANCE_VLAN_TYPE

		A byte containing the id of the VLAN.

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- Status LED:	CONFIG_STATUS_LED

		Several configurations allow to display the current
		status using a LED. For instance, the LED will blink
		fast while running U-Boot code, stop blinking as
		soon as a reply to a BOOTP request was received, and
		start blinking slow once the Linux kernel is running
		(supported by a status LED driver in the Linux
		kernel). Defining CONFIG_STATUS_LED enables this
		feature in U-Boot.

- CAN Support:	CONFIG_CAN_DRIVER

		Defining CONFIG_CAN_DRIVER enables CAN driver support
		on those systems that support this (optional)
		feature, like the TQM8xxL modules.

- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C

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		These enable I2C serial bus commands. Defining either of
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		(but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
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		include the appropriate I2C driver for the selected CPU.
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		This will allow you to use i2c commands at the u-boot
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		command line (as long as you set CONFIG_CMD_I2C in
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		CONFIG_COMMANDS) and communicate with i2c based realtime
		clock chips. See common/cmd_i2c.c for a description of the
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		command line interface.
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		CONFIG_HARD_I2C selects a hardware I2C controller.
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		CONFIG_SOFT_I2C configures u-boot to use a software (aka
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		bit-banging) driver instead of CPM or similar hardware
		support for I2C.
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		There are several other quantities that must also be
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		defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
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		In both cases you will need to define CONFIG_SYS_I2C_SPEED
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		to be the frequency (in Hz) at which you wish your i2c bus
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		to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
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		the CPU's i2c node address).
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