#!/bin/sh

mount /dev/sda /mnt || exit 1
 
cp ~matthias/bzImage /mnt/new/ &&
cp ~matthias/rootfs.cpio.xz /mnt/new/ &&
(cd /mnt/new ; md5sum -c ~matthias/MD5SUMS) || (umount /mnt; exit 2)

sync

cd /mnt
mv bzImage bzImage.old
mv rootfs.cpio.xz rootfs.cpio.xz.old

mv new/bzImage new/rootfs.cpio.xz . &&
sync || (mv bzImage.old bzImage; mv rootfs.cpio.xz.old rootfs.cpio.xz; cd / ; umount /mnt; exit 3)

reboot
exit 0