diff -r 000000000000 -r 6474c204b198 tools/reorder/elf_utils.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/reorder/elf_utils.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <fstream>
+#include "elf_utils.h"
+
+int
+elf_verify_header(const Elf32_Ehdr *hdr)
+{
+    if (hdr->e_ident[EI_MAG0] != ELFMAG0
+        || hdr->e_ident[EI_MAG1] != ELFMAG1
+        || hdr->e_ident[EI_MAG2] != ELFMAG2
+        || hdr->e_ident[EI_MAG3] != ELFMAG3) {
+        cerr << "not an elf file" << endl;
+        return -1;
+    }
+
+    if (hdr->e_ident[EI_CLASS] != ELFCLASS32) {
+        cerr << "not a 32-bit elf file" << endl;
+        return -1;
+    }
+
+    if (hdr->e_ident[EI_DATA] != ELFDATA2LSB) {
+        cerr << "not a little endian elf file" << endl;
+        return -1;
+    }
+
+    if (hdr->e_ident[EI_VERSION] != EV_CURRENT) {
+        cerr << "incompatible version" << endl;
+        return -1;
+    }
+
+    return 0;
+}
+