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|
#!/bin/bash
# Copyright (C) 2012 Codethink Limited
#
# 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; version 2 of the License.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
set -ex
usage()
{
cat 1>&2 <<EOF
Make a system image called DEST filled with the contents of TARBALL...
usage: $0 DEST TARBALL...
EOF
}
dummy_kpartx_add()
{
local img="$1"
local start=$(sfdisk -d "$img" |
awk '
$3 == "start=" && $4 != "0," {
gsub(/,/, "", $4)
print $4 * 512
}
')
losetup -o "$start" -f "$img"
local device=""
while true
do
device=$(losetup -j "$img" | sed 's,^\(/dev/loop[^:]*\):.*,\1,')
if [ "x$device" != x ]
then
break
fi
done
echo "$device"
}
dummy_kpartx_delete()
{
losetup -j "$1" |
sed 's,^\(/dev/loop[^:]*\):.*,\1,' |
while read device
do
losetup -d "$device"
done
}
if [ "$#" -le 1 ]; then
usage
exit 1
fi
img="$1"
shift
# Create an empty file (a hole) as the raw disk image file.
dd if=/dev/zero of="$img" bs=1k seek=16777216 count=0
# Partition. See the sfdisk(8) manpage for an explanation of the input.
sfdisk "$img" <<EOF
1,,83,*
EOF
# Install the master boot record boot loader. We use the one from extlinux.
# Depending on where we run this script (Debian vs Baserock), it might
# be installed in a different place, so we try all known ones.
for x in /usr/lib/extlinux/mbr.bin /usr/share/syslinux/mbr.bin
do
if [ -e "$x" ]
then
dd if="$x" of="$img" conv=notrunc
break
fi
done
# Access the partition inside the raw disk image file.
part=$(dummy_kpartx_add "$img")
trap "dummy_kpartx_delete $img" EXIT
# Create filesystem. Note that for some reason sfdisk and mkfs when used
# on the loop device from dummy_kpartx_add get the image size wrong by
# about one block, which makes things break. So we force a filesystem
# size that fits (even if it doesn't quite fill the image).
mkfs -t ext4 -q "$part" 4194304
# Mount the filesystem.
mp="$(mktemp -d)"
mount "$part" "$mp"
trap "umount $part; dummy_kpartx_delete $img" EXIT
# Unpack all the strata that are to be installed.
for stratum
do
tar -C "$mp" -xhf "$stratum"
done
# Configure fstab for the new system.
cat <<EOF > "$mp/etc/fstab"
/dev/sda1 / ext4 errors=remount-ro 0 1
EOF
# Install extlinux as the bootloader.
cat <<EOF > "$mp/extlinux.conf"
default linux
timeout 1
label linux
kernel /boot/vmlinuz
append root=/dev/sda1 init=/sbin/init rw
EOF
extlinux --install "$mp"
sync
sleep 2
|
