43 lines
1016 B
Bash
43 lines
1016 B
Bash
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#!/bin/sh
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ROOTIMG=$1
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if [ x$ROOTIMG = x ] ; then
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echo "usage: $0 <root.img>"
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exit 0
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fi
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# We assume that the input root.img has the following structure:
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# /dev/sda1 <--- root fs
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# /dev/sda2 <--- swap
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# and that the first partition starts at offset 63*512 from the begging of the image file
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OFFSET=$((63*512))
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mkdir -p mnt
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MNTDIR=$(pwd)/mnt
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LOOP=$(/sbin/losetup -f -s -o $OFFSET $ROOTIMG)
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if [ x$LOOP = x ] ; then
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echo "Cannot setup loopback device for the $ROOTIMG file -- perhaps a permissions problem?"
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exit 1
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fi
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mount $LOOP $MNTDIR || {
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echo "Cannot mount $LOOP to $MNTDIR"
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/sbin/losetup -d $LOOP
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exit 2
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}
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# generate unmount script
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BASENAE=$(basename $ROOTIMG)
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UNMOUNT_SCRIPT=$(echo unmount_root-$BASENAE.sh)
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echo "#!/bin/sh" > $UNMOUNT_SCRIPT
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echo "umount $MNTDIR || { echo \"Cannot unmount!\"; exit 1; }" >> $UNMOUNT_SCRIPT
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echo "/sbin/losetup -d $LOOP || { echo \"Cannot delete the loop device\"; exit 1; }" >> $UNMOUNT_SCRIPT
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echo "rm -f $UNMOUNT_SCRIPT" >> $UNMOUNT_SCRIPT
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chmod +x $UNMOUNT_SCRIPT
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