update-kernel: destination directory argument

update-kernel.in

@@ -14,17 +14,23 @@ SIGNALS="HUP INT TERM"
 SCRIPT=update-kernel
 VIRTUAL=.tmp-$SCRIPT
 
-while read MOUNT; do
+
+DESTDIR=$1
+MNTDIR=
+
+if [ -z "$DESTDIR" ]; then
+    while read MOUNT; do
 	set -- $MOUNT
 	[ $2 = /.modloop ] || continue
 	DESTDIR=$(dirname $(losetup $1 | cut -d " " -f 3))
 	MNTDIR=$(dirname $DESTDIR)
 	break
-done < /proc/mounts
+    done < /proc/mounts
 
-if [ -z "$MNTDIR" ]; then
+    if [ -z "$MNTDIR" ]; then
 	echo "Module loopback device not mounted" >&2
 	exit 1
+    fi
 fi
 
 remount() {
@@ -83,14 +89,18 @@ mkinitfs -q -F "$features squashfs" -b $ROOT -o $STAGING/$FLAVOR.gz $KVER
 cp $ROOT/boot/vmlinuz-$FLAVOR $STAGING/$FLAVOR
 
 
-ignore_sigs
-remount -w
+if [ "$MNTDIR" ]; then
+    ignore_sigs
+    remount -w
+    rm -f "$DESTDIR/$MODIMG"
+fi
 
-rm -f $DESTDIR/$MODIMG
-mv $STAGING/* $DESTDIR
+mv $STAGING/* "$DESTDIR"
 
-set +e
-sync
-remount -r
+if [ "$MNTDIR" ]; then
+    set +e
+    sync
+    remount -r
+fi
 
 exit 0