Add missing tools/buildrom.py script.

diff --git a/tools/buildrom.py b/tools/buildrom.py
new file mode 100755 (executable)
index 0000000..19b715a
--- /dev/null
+++ b/tools/buildrom.py
@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+# Fill in checksum/size of an option rom, and pad it to proper length.
+#
+# Copyright (C) 2009  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+import sys
+
+def alignpos(pos, alignbytes):
+    mask = alignbytes - 1
+    return (pos + mask) & ~mask
+
+def checksum(data):
+    ords = map(ord, data)
+    return sum(ords)
+
+def main():
+    inname = sys.argv[1]
+    outname = sys.argv[2]
+
+    # Read data in
+    f = open(inname, 'rb')
+    data = f.read()
+    count = len(data)
+
+    # Pad to a 512 byte boundary
+    data += "\0" * (alignpos(count, 512) - count)
+    count = len(data)
+
+    # Fill in size field; clear checksum field
+    data = data[:2] + chr(count/512) + data[3:6] + "\0" + data[7:]
+
+    # Checksum rom
+    newsum = (256 - checksum(data)) & 0xff
+    data = data[:6] + chr(newsum) + data[7:]
+
+    # Write new rom
+    f = open(outname, 'wb')
+    f.write(data)
+
+if __name__ == '__main__':
+    main()