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gavz/extract-uimage.sh

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Created March 28, 2025 22:22
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  1. Adam Rudd created this gist Jul 13, 2011.
    71 changes: 71 additions & 0 deletions extract-uimage.sh
    View file
    Original file line number Diff line number Diff line change
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    #!/bin/sh

    #
    # Copyright (C) 2010 Matthias Buecher (http://www.maddes.net/)
    #
    # 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.
    # http://www.gnu.org/licenses/gpl-2.0.txt
    #
    # 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
    #

    UIMAGE=$1

    # check for uImage magic word
    # http://u-boot.cvs.sourceforge.net/viewvc/u-boot/u-boot/include/image.h?view=markup
    echo 'Checking for uImage magic word...'
    MAGIC=`dd if="${UIMAGE}" ibs=4 count=1 | hexdump -v -e '1/1 "%02X"'`
    [ '27051956' != "${MAGIC}" ] && { echo 'Not an uImage.' ; exit 1 ; }

    # extract data from uImage
    echo 'uImage recognized.'
    echo 'Extracting data...'
    DATAFILE='uImage.data'
    dd if="${UIMAGE}" of="${DATAFILE}" ibs=64 skip=1

    # check for ARM mach type ( xx 1C A0 E3 xx 10 81 E3 )
    # http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html#d0e600
    echo 'Checking for ARM mach-type...'
    MAGIC=`dd if="${DATAFILE}" ibs=1 skip=1 count=3 | hexdump -v -e '1/1 "%02X"'`
    [ '1CA0E3' = "${MAGIC}" ] && {
    MAGIC=`dd if="${DATAFILE}" ibs=1 skip=5 count=3 | hexdump -v -e '1/1 "%02X"'`
    [ '1081E3' = "${MAGIC}" ] && {
    echo 'ARM mach-type header recognized.'
    echo 'Extracting mach-type header...'
    dd if="${DATAFILE}" of="uImage.mach-type" ibs=8 count=1
    ARCH=$(hexdump -v -e '1/1 "%02X "' uImage.mach-type); echo "The mach-type is: $ARCH"
    echo 'Stripping mach-type header...'
    TMPFILE='uImage.tmp'
    dd if="${DATAFILE}" of="${TMPFILE}" ibs=8 skip=1
    rm -f "${DATAFILE}"
    mv "${TMPFILE}" "${DATAFILE}"
    }
    }

    # check for zImage, otherwise assume Image
    # http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html#d0e309
    TMPFILE='Image'
    echo 'Checking for zImage...'
    MAGIC=`dd if="${DATAFILE}" ibs=4 skip=9 count=1 | hexdump -v -e '1/1 "%02X"'`
    [ '18286F01' = "${MAGIC}" ] && {
    START=`dd if="${DATAFILE}" ibs=4 skip=10 count=1 | hexdump -v -e '1/4 "%08X"'`
    END=`dd if="${DATAFILE}" ibs=4 skip=11 count=1 | hexdump -v -e '1/4 "%08X"'`
    #
    SIZE=$(( 0x${END} - 0x${START} ))
    #
    echo "zImage recognized with start 0x${START}, end 0x${END} and size ${SIZE}."
    TMPFILE='zImage'
    }
    mv "${DATAFILE}" "${TMPFILE}"

    echo ">>> ${UIMAGE} extracted to ${TMPFILE}"