Init

tools/prove_checksum.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+"""Verify cmtd+0x08 checksums: prove_checksum.py a.bin [b.bin ...]
+
+Exit 0 iff every image's stored checksum equals compute_checksum(image).
+See lofi_image.compute_checksum for the algorithm.
+"""
+import os
+import struct
+import sys
+
+sys.path.insert(0, os.path.dirname(__file__))
+from lofi_image import compute_checksum, parse_image
+
+
+def main() -> int:
+    ok = True
+    for path in sys.argv[1:]:
+        d = open(path, "rb").read()
+        info = parse_image(d)  # validates container chain
+        stored = info["cmtd"]["checksum"]
+        calc = compute_checksum(d)
+        match = stored == calc
+        ok &= match
+        fw = ".".join(map(str, info["mmtd"]["fw"]))
+        print("%s fw=%s size=%d stored=%08X calc=%08X %s"
+              % (path, fw, len(d), stored, calc,
+                 "MATCH" if match else "MISMATCH"))
+    return 0 if ok and len(sys.argv) > 1 else 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())