add support for zsync file downloads
diff --git a/build-images.py b/build-images.py
index 7e551bd..30dcfe3 100755
--- a/build-images.py
+++ b/build-images.py
@@ -71,6 +71,12 @@
     print "compressing %s" % imgfile
     args = ('bzip2', imgfile)
     cmd_runner.run(args).wait()
+    return '%s.bz2' % imgfile
+
+def zsync_image(imgfile):
+    print "making zsync file for %s" % imgfile
+    args = ('zsyncmake', '-o', '%s.zsync'%imgfile, imgfile)
+    cmd_runner.run(args).wait()
 
 def build_image(lmc, imgfile, hwpack, hwpack_file, binary, binary_file):
     print "building image: %s" % imgfile
@@ -95,7 +101,8 @@
         args.append(script)
 
     cmd_runner.run(args, as_root=True).wait()
-    compress_image(imgfile)
+    bz2file = compress_image(imgfile)
+    zsync_image(bz2file)
 
 def main():
     day = today()