mkdir -p "$rootdir/sys"
mkdir -p "$rootdir/dev"
+trap 'ret=$?; [[ -d $rootdir ]] && { umount "$rootdir/proc"; umount "$rootdir/sys"; umount "$rootdir/dev"; rm -rf "$rootdir"; }; exit $ret;' EXIT
+trap '[[ -d $rootdir ]] && { umount "$rootdir/proc"; umount "$rootdir/sys"; umount "$rootdir/dev"; rm -rf "$rootdir"; }; exit 1;' SIGINT
+
mount --bind /proc "$rootdir/proc"
mount --bind /sys "$rootdir/sys"
mount -t devtmpfs devtmpfs "$rootdir/dev"