diff --git a/patch/bdiff.sh b/patch/bdiff.sh
new file mode 100755
index 0000000000..33d109bd8c
--- /dev/null
+++ b/patch/bdiff.sh
@@ -0,0 +1,31 @@
+#! /bin/sh -e
+
+DIFF=/home/eelco/Dev/nix/zdelta-2.1/zdc
+
+srcA=$1
+srcB=$2
+
+if test -z "$srcA" -o -z "$srcB"; then
+    echo "syntax: bdiff.sh srcA srcB"
+    exit 1
+fi
+
+(cd $srcB && find . -type f) | while read fn; do
+
+    echo "$fn" >&2
+
+    if test -f "$srcA/$fn"; then
+
+	echo "FILE DELTA FOR $fn"
+
+	$DIFF "$srcA/$fn" "$srcB/$fn"
+
+    else
+
+	echo "NEW FILE $fn"
+
+	cat "$srcB/$fn"
+
+    fi
+
+done