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#
# (C) Copyright 2000 - 2002
# 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 and ARM 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
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
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.

In case of problems see the CHANGELOG and CREDITS files to find out
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who contributed the specific port.


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-users@lists.sourceforge.net>. There is also an archive of
previous traffic on the mailing list - please search the archive
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before asking FAQ's. Please see
http://lists.sourceforge.net/lists/listinfo/u-boot-users/


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

- start from 8xxrom sources
- 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
  * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
- create ARMBoot project (http://sourceforge.net/projects/armboot)
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- add other CPU families (starting with ARM)
- create U-Boot project (http://sourceforge.net/projects/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:
===========

U-Boot uses a 3 level version number containing a version, a
sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
sub-version "34", and patchlevel "4".

The patchlevel is used to indicate certain stages of development
between released versions, i. e. officially released versions of
U-Boot will always have a patchlevel of "0".


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

- board		Board dependent files
- common	Misc architecture independent functions
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- cpu		CPU specific files
- disk		Code for disk drive partition handling
- doc		Documentation (don't expect too much)
- drivers	Commonly used device drivers
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- dtt		Digital Thermometer and Thermostat drivers
- examples	Example code for standalone applications, etc.
- include	Header Files
- disk		Harddisk interface code
- net		Networking code
- ppc		Files generic to PowerPC architecture
- post		Power On Self Test
- post/arch		Symlink to architecture specific Power On Self Test
- post/arch-ppc		PowerPC architecture specific Power On Self Test
- post/cpu/mpc8260	MPC8260 CPU specific Power On Self Test
- post/cpu/mpc8xx	MPC8xx CPU specific Power On Self Test
- rtc		Real Time Clock drivers
- tools		Tools to build S-Record or U-Boot images, etc.

- cpu/74xx_7xx	Files specific to Motorola MPC74xx and 7xx CPUs
- cpu/arm925t	Files specific to ARM	   925	   CPUs
- cpu/arm926ejs	Files specific to ARM	926	CPUs
- cpu/mpc5xx	Files specific to Motorola MPC5xx  CPUs
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- cpu/mpc8xx	Files specific to Motorola MPC8xx  CPUs
- cpu/mpc824x	Files specific to Motorola MPC824x CPUs
- cpu/mpc8260	Files specific to Motorola MPC8260 CPU
- cpu/ppc4xx	Files specific to IBM	   4xx	   CPUs

- board/LEOX/   Files specific to boards manufactured by The LEOX team
- board/LEOX/elpt860	Files specific to ELPT860 boards
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- board/RPXClassic
		Files specific to RPXClassic boards
- board/RPXlite	Files specific to RPXlite    boards
- board/at91rm9200dk Files specific to AT91RM9200DK boards
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- board/c2mon	Files specific to c2mon	     boards
- board/cmi	Files specific to cmi        boards
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- board/cogent	Files specific to Cogent     boards
		(need further configuration)
		Files specific to CPCIISER4  boards
- board/cpu86	Files specific to CPU86      boards
- board/cray/	Files specific to boards manufactured by Cray
- board/cray/L1		Files specific to L1         boards
- board/cu824	Files specific to CU824	     boards
- board/ebony   Files specific to IBM Ebony board
- board/eric	Files specific to ERIC	     boards
- board/esd/	Files specific to boards manufactured by ESD
- board/esd/adciop	Files specific to ADCIOP     boards
- board/esd/ar405	Files specific to AR405	     boards
- board/esd/canbt	Files specific to CANBT	     boards
- board/esd/cpci405	Files specific to CPCI405    boards
- board/esd/cpciiser4	Files specific to CPCIISER4  boards
- board/esd/common	Common files for ESD boards
- board/esd/dasa_sim	Files specific to DASA_SIM   boards
- board/esd/du405	Files specific to DU405      boards
- board/esd/ocrtc	Files specific to OCRTC      boards
- board/esd/pci405	Files specific to PCI405     boards
- board/esteem192e
		Files specific to ESTEEM192E boards
- board/etx094	Files specific to ETX_094    boards
- board/evb64260
		Files specific to EVB64260   boards
- board/fads	Files specific to FADS	     boards
- board/flagadm Files specific to FLAGADM    boards
- board/gen860t Files specific to GEN860T and GEN860T_SC    boards
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- board/genietv Files specific to GENIETV    boards
- board/gth	Files specific to GTH	     boards
- board/hermes	Files specific to HERMES     boards
- board/hymod	Files specific to HYMOD	     boards
- board/icu862	Files specific to ICU862     boards
- board/ip860	Files specific to IP860	     boards
- board/iphase4539
		Files specific to Interphase4539 boards
- board/ivm	Files specific to IVMS8/IVML24 boards
- board/lantec	Files specific to LANTEC     boards
- board/lwmon	Files specific to LWMON	     boards
- board/mbx8xx	Files specific to MBX	     boards
- board/mpc8260ads
		Files specific to MPC8260ADS and PQ2FADS-ZU boards
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- board/mpl/	Files specific to boards manufactured by MPL
- board/mpl/common	Common files for MPL boards
- board/mpl/pip405	Files specific to PIP405     boards
- board/mpl/mip405	Files specific to MIP405     boards
- board/mpl/vcma9	Files specific to VCMA9      boards
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- board/musenki	Files specific to MUSEKNI    boards
- board/mvs1	Files specific to MVS1       boards
- board/nx823   Files specific to NX823      boards
- board/oxc	Files specific to OXC        boards
		Files specific to OMAP 1510 Innovator boards
- board/omap1610inn  
		Files specific to OMAP 1610 Innovator boards
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- board/pcippc2	Files specific to PCIPPC2/PCIPPC6 boards
- board/pm826	Files specific to PM826      boards
- board/ppmc8260
		Files specific to PPMC8260   boards
- board/rpxsuper
		Files specific to RPXsuper   boards
- board/rsdproto
		Files specific to RSDproto   boards
- board/sandpoint
		Files specific to Sandpoint  boards
- board/sbc8260	Files specific to SBC8260    boards
- board/sacsng	Files specific to SACSng     boards
- board/siemens Files specific to boards manufactured by Siemens AG
- board/siemens/CCM	Files specific to CCM	     boards
- board/siemens/IAD210	Files specific to IAD210     boards
- board/siemens/SCM	Files specific to SCM        boards
- board/siemens/pcu_e	Files specific to PCU_E	     boards
- board/sixnet	Files specific to SIXNET     boards
- board/spd8xx	Files specific to SPD8xxTS   boards
- board/tqm8260 Files specific to TQM8260    boards
- board/tqm8xx	Files specific to TQM8xxL    boards
- board/w7o	Files specific to W7O        boards
- board/walnut405
		Files specific to Walnut405  boards
- board/westel/	Files specific to boards manufactured by Westel Wireless
- board/westel/amx860	Files specific to AMX860     boards
- board/utx8245	Files specific to UTX8245   boards

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
  "CFG_".

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.


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The following options need to be configured:

- CPU Type:	Define exactly one of

		PowerPC based CPUs:
		-------------------
		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
	or	CONFIG_MPC5xx
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	or	CONFIG_MPC824X, CONFIG_MPC8260
	or	CONFIG_IOP480
	or	CONFIG_405GP
	or	CONFIG_405EP
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	or	CONFIG_440
	or	CONFIG_MPC74xx
	or	CONFIG_750FX
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		ARM based CPUs:
		---------------
		CONFIG_SA1110
		CONFIG_ARM7
		CONFIG_PXA250


- Board Type:	Define exactly one of

		PowerPC based boards:
		---------------------

		CONFIG_ADCIOP,     CONFIG_ICU862      CONFIG_RPXsuper,
		CONFIG_ADS860,     CONFIG_IP860,      CONFIG_SM850,
		CONFIG_AMX860,     CONFIG_IPHASE4539, CONFIG_SPD823TS,
		CONFIG_AR405,      CONFIG_IVML24,     CONFIG_SXNI855T,
		CONFIG_BAB7xx,     CONFIG_IVML24_128, CONFIG_Sandpoint8240,
		CONFIG_CANBT,      CONFIG_IVML24_256, CONFIG_Sandpoint8245,
		CONFIG_CCM,        CONFIG_IVMS8,      CONFIG_TQM823L,
		CONFIG_CPCI405,    CONFIG_IVMS8_128,  CONFIG_TQM850L,
		CONFIG_CPCI4052,   CONFIG_IVMS8_256,  CONFIG_TQM855L,
		CONFIG_CPCIISER4,  CONFIG_LANTEC,     CONFIG_TQM860L,
		CONFIG_CPU86,      CONFIG_MBX,        CONFIG_TQM8260,
		CONFIG_CRAYL1,     CONFIG_MBX860T,    CONFIG_TTTech,
		CONFIG_CU824,      CONFIG_MHPC,       CONFIG_UTX8245,
		CONFIG_DASA_SIM,   CONFIG_MIP405,     CONFIG_W7OLMC,
		CONFIG_DU405,      CONFIG_MOUSSE,     CONFIG_W7OLMG,
		CONFIG_ELPPC,      CONFIG_MPC8260ADS, CONFIG_WALNUT405,
		CONFIG_ERIC,       CONFIG_MUSENKI,    CONFIG_ZUMA,
		CONFIG_ESTEEM192E, CONFIG_MVS1,       CONFIG_c2mon,
		CONFIG_ETX094,     CONFIG_NX823,      CONFIG_cogent_mpc8260,
		CONFIG_EVB64260,   CONFIG_OCRTC,      CONFIG_cogent_mpc8xx,
		CONFIG_FADS823,    CONFIG_ORSG,       CONFIG_ep8260,
		CONFIG_FADS850SAR, CONFIG_OXC,        CONFIG_gw8260,
		CONFIG_FADS860T,   CONFIG_PCI405,     CONFIG_hermes,
		CONFIG_FLAGADM,    CONFIG_PCIPPC2,    CONFIG_hymod,
		CONFIG_FPS850L,    CONFIG_PCIPPC6,    CONFIG_lwmon,
		CONFIG_GEN860T,    CONFIG_PIP405,     CONFIG_pcu_e,
		CONFIG_GENIETV,    CONFIG_PM826,      CONFIG_ppmc8260,
		CONFIG_GTH,        CONFIG_RPXClassic, CONFIG_rsdproto,
		CONFIG_IAD210,     CONFIG_RPXlite,    CONFIG_sbc8260,
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		CONFIG_EBONY,      CONFIG_sacsng,     CONFIG_FPS860L,
		CONFIG_V37,        CONFIG_ELPT860,    CONFIG_CMI,
		CONFIG_NETVIA,     CONFIG_RBC823
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		ARM based boards:
		-----------------

		CONFIG_HHP_CRADLE,  CONFIG_DNP1110,    CONFIG_EP7312,
		CONFIG_IMPA7,       CONFIG_LART,       CONFIG_LUBBOCK,
		CONFIG_INNOVATOROMAP1510,	CONFIG_INNOVATOROMAP1610
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		CONFIG_SHANNON,     CONFIG_SMDK2400,   CONFIG_SMDK2410,
		CONFIG_TRAB,	    CONFIG_VCMA9,      CONFIG_AT91RM9200DK
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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
					  the lcd display every second with
					  a "rotator" |\-/|\-/

- Board flavour: (if CONFIG_MPC8260ADS is defined)
		CONFIG_ADSTYPE
		Possible values are:
			CFG_8260ADS	- original MPC8260ADS
			CFG_8266ADS	- MPC8266ADS (untested)
			CFG_PQ2FADS	- PQ2FADS-ZU


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- MPC824X Family Member (if CONFIG_MPC824X is defined)
	Define exactly one of
	CONFIG_MPC8240, CONFIG_MPC8245

- 8xx CPU Options: (if using an 8xx cpu)
		Define one or more of
		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() can not work e.g.
					  no 32KHz reference PIT/RTC clock

- Clock 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.

- 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
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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)
			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)
			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
			CONFIG_CONSOLE_TIME	display time/date info in
						upper right corner
						(requires CFG_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
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			CONFIG_CONSOLE_EXTRA_INFO
						addional 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'.
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- Console Baudrate:
		CONFIG_BAUDRATE - in bps
		Select one of the baudrates listed in
		CFG_BAUDRATE_TABLE, see below.

- Interrupt driven serial port input:
		CONFIG_SERIAL_SOFTWARE_FIFO

		PPC405GP only.
		Use an interrupt handler for receiving data on the
		serial port. It also enables using hardware handshake
		(RTS/CTS) and UART's built-in FIFO. Set the number of
		bytes the interrupt driven input buffer should have.

		Set to 0 to disable this feature (this is the default).
		This will also disable hardware handshake.

- Console UART Number:
		CONFIG_UART1_CONSOLE

		IBM PPC4xx only.
		If defined internal UART1 (and not UART0) is used
		as default U-Boot console.

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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
		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
		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.
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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.

- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
		CONFIG_KGDB_BAUDRATE
		Select one of the baudrates listed in
		CFG_BAUDRATE_TABLE, see below.

- Monitor Functions:
		CONFIG_COMMANDS
		Most monitor functions can be selected (or
		de-selected) by adjusting the definition of
		CONFIG_COMMANDS; to select individual functions,
		#define CONFIG_COMMANDS by "OR"ing any of the
		following values:

		#define enables commands:
		-------------------------
		CFG_CMD_ASKENV	* ask for env variable
		CFG_CMD_AUTOSCRIPT Autoscript Support
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		CFG_CMD_BDI	  bdinfo
		CFG_CMD_BEDBUG	  Include BedBug Debugger
		CFG_CMD_BMP     * BMP support
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		CFG_CMD_BOOTD	  bootd
		CFG_CMD_CACHE	  icache, dcache
		CFG_CMD_CONSOLE	  coninfo
		CFG_CMD_DATE	* support for RTC, date/time...
		CFG_CMD_DHCP	  DHCP support
		CFG_CMD_DIAG    * Diagnostics
		CFG_CMD_DOC     * Disk-On-Chip Support
		CFG_CMD_DTT       Digital Therm and Thermostat 
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		CFG_CMD_ECHO	* echo arguments
		CFG_CMD_EEPROM	* EEPROM read/write support
		CFG_CMD_ELF	  bootelf, bootvx
		CFG_CMD_ENV	  saveenv
		CFG_CMD_FDC	* Floppy Disk Support
		CFG_CMD_FAT	  FAT partition support
		CFG_CMD_FDOS	* Dos diskette Support
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		CFG_CMD_FLASH	  flinfo, erase, protect
		CFG_CMD_FPGA	  FPGA device initialization support
		CFG_CMD_HWFLOW  * RTS/CTS hw flow control
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		CFG_CMD_I2C	* I2C serial bus support
		CFG_CMD_IDE	* IDE harddisk support
		CFG_CMD_IMI	  iminfo
		CFG_CMD_IMLS      List all found images
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		CFG_CMD_IMMAP	* IMMR dump support
		CFG_CMD_IRQ	* irqinfo
		CFG_CMD_JFFS2   * JFFS2 Support
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		CFG_CMD_KGDB	* kgdb
		CFG_CMD_LOADB	  loadb
		CFG_CMD_LOADS	  loads
		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
				  loop, mtest
		CFG_CMD_MISC      Misc functions like sleep etc
		CFG_CMD_MMC	  MMC memory mapped support
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		CFG_CMD_MII	  MII utility commands
		CFG_CMD_NAND    * NAND support
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		CFG_CMD_NET	  bootp, tftpboot, rarpboot
		CFG_CMD_PCI	* pciinfo
		CFG_CMD_PCMCIA	* PCMCIA support
		CFG_CMD_PING    * send ICMP ECHO_REQUEST to network host
		CFG_CMD_PORTIO    Port I/O
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		CFG_CMD_REGINFO * Register dump
		CFG_CMD_RUN	  run command in env variable
		CFG_CMD_SAVES     save S record dump
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		CFG_CMD_SCSI	* SCSI Support
		CFG_CMD_SDRAM   * print SDRAM configuration information
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		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
		CFG_CMD_SPI	* SPI serial bus support
		CFG_CMD_USB	* USB support
		CFG_CMD_VFD     * VFD support (TRAB)
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		CFG_CMD_BSP	* Board SPecific functions
		-----------------------------------------------
		CFG_CMD_ALL	all

		CFG_CMD_DFL	Default configuration; at the moment
				this is includes all commands, except
				the ones marked with "*" in the list
				above.

		If you don't define CONFIG_COMMANDS it defaults to
		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
		override the default settings in the respective
		include file.

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

		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)


	Note:	Don't enable the "icache" and "dcache" commands
		(configuration option CFG_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.
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		XXX - this list needs to get updated!

- Watchdog:
		CONFIG_WATCHDOG
		If this variable is defined, it enables watchdog
		support. There must be support in the platform specific
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		code for a watchdog. For the 8xx and 8260 CPUs, the
		SIU Watchdog feature is enabled in the SYPCR
		register.

- 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:

		When CFG_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_MC146818	- use MC146818 RTC
		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
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		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
		CONFIG_RTC_DS164x	- use Dallas DS164x 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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- 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 CFG_CMD_DATE .
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- Partition Support:
		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
		and/or CONFIG_ISO_PARTITION

		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
		CFG_CMD_SCSI) you must configure support for at least
		one partition type as well.

- IDE Reset method:
		CONFIG_IDE_RESET_ROUTINE

		Set this to define that instead of a reset Pin, the
		routine ide_set_reset(int idereset) will be used.

- ATAPI Support:
		CONFIG_ATAPI

		Set this to enable ATAPI support.

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

		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
		CFG_SCSI_MAX_LUN] can be adjusted to define the
		maximum numbers of LUNs, SCSI ID's and target
		devices.
		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)

- NETWORK Support (PCI):
		CONFIG_E1000
		Support for Intel 8254x gigabit chips.
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		CONFIG_EEPRO100
		Support for Intel 82557/82559/82559ER chips.
		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
		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.

- NETWORK Support (other):

		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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- USB Support:
		At the moment only the UHCI host controller is
		supported (PIP405, MIP405); define
		CONFIG_USB_UHCI to enable it.
		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
		end define CONFIG_USB_STORAGE to enable the USB
		storage devices.
		Note:
		Supported are USB Keyboards and USB Floppy drives
		(TEAC FD-05PUB).

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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
		to physical memory similar to flash. Command line is
		enabled with CFG_CMD_MMC. The MMC driver also works with
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		the FAT fs. This is enabled with CFG_CMD_FAT.
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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
		Enable Silicon Motion SMI 712/710/810 Video chip
		Videomode are selected via environment 'videomode' with
		standard LiLo mode numbers.
		Following modes are supported  (* is default):

			    800x600  1024x768  1280x1024
	      256  (8bit)     303*      305       307
	    65536 (16bit)     314       317       31a
	16,7 Mill (24bit)     315       318       31b
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		(i.e. setenv videomode 317; saveenv; reset;)

		Enable Epson SED13806 driver. This driver supports 8bpp
		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
		or CONFIG_VIDEO_SED13806_16BPP

- 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:

		CONFIG_NEC_NL6648AC33:

			NEC NL6648AC33-18. Active, color, single scan.

		CONFIG_NEC_NL6648BC20

			NEC NL6648BC20-08. 6.5", 640x480.
			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
		CFG_WHITE_ON_BLACK to get it inverted.

- 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
		is supressed and the BMP image at the address
		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.
- 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.

                NOTE: the bzip2 algorithm requires a lot of RAM, so
                the malloc area (as defined by CFG_MALLOC_LEN) should
                be at least 4MB.
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- Ethernet address:
		CONFIG_ETHADDR
		CONFIG_ETH2ADDR
		CONFIG_ETH3ADDR

		Define a default value for ethernet address to use
		for the respective ethernet interface, in case this
		is not determined automatically.

- IP address:
		CONFIG_IPADDR

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

- Server IP address:
		CONFIG_SERVERIP

		Defines a default value for theIP address of a TFTP
		server to contact when using the "tftboot" command.

- 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
		following delays are insterted then:

		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

- DHCP Advanced Options:
		CONFIG_BOOTP_MASK

		You can fine tune the DHCP functionality by adding
		these flags to the CONFIG_BOOTP_MASK define:

		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
		is added to the CONFIG_BOOTP_MASK.

		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.
		If CONFIG_BOOP_SEND_HOSTNAME is added to the
		CONFIG_BOOTP_MASK, the content of the "hostname"
		environment variable is passed as option 12 to
		the DHCP server.

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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

		These enable I2C serial bus commands. Defining either of
		(but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
		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
		command line (as long as you set CFG_CMD_I2C in
		CONFIG_COMMANDS) and communicate with i2c based realtime
		clock chips. See common/cmd_i2c.c for a description of the
		command line interface.
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		CONFIG_HARD_I2C	selects the CPM hardware driver for I2C.
		CONFIG_SOFT_I2C configures u-boot to use a software (aka
		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
		defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
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		In both cases you will need to define CFG_I2C_SPEED
		to be the frequency (in Hz) at which you wish your i2c bus
		to run and CFG_I2C_SLAVE to be the address of this node (ie
		the cpu's i2c node address).

		Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)