diff --git a/applypatch/utils.h b/applypatch/utils.h
new file mode 100644
index 0000000..d6d6f1d
--- /dev/null
+++ b/applypatch/utils.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _BUILD_TOOLS_APPLYPATCH_UTILS_H
+#define _BUILD_TOOLS_APPLYPATCH_UTILS_H
+
+#include <stdio.h>
+
+// Read and write little-endian values of various sizes.
+
+void Write4(int value, FILE* f);
+void Write8(long long value, FILE* f);
+int Read2(unsigned char* p);
+int Read4(unsigned char* p);
+long long Read8(unsigned char* p);
+
+#endif //  _BUILD_TOOLS_APPLYPATCH_UTILS_H