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authorJan Kiszka <jan.kiszka@siemens.com>2012-01-27 19:44:53 +0100
committerJan Kiszka <jan.kiszka@siemens.com>2012-04-16 15:41:20 +0200
commit0d6b9cc7420dd2d531b48508f0d4083d1c6a632a (patch)
treeae3bae24b4b18ad28fedbed9da949c1198cbd3d6 /scripts/signrom.py
parente6f5d0be730a41bacb10edba19d1369ec2949486 (diff)
downloadqemu-arm-0d6b9cc7420dd2d531b48508f0d4083d1c6a632a.tar.gz
signrom: Rewrite as python script
Now that we have a hard dependency on python anyway, we can replace the slow shell script to calculate the option ROM checksum with a fast AND portable python version. Tested both with python 2.7 and 3.1. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Diffstat (limited to 'scripts/signrom.py')
-rw-r--r--scripts/signrom.py40
1 files changed, 40 insertions, 0 deletions
diff --git a/scripts/signrom.py b/scripts/signrom.py
new file mode 100644
index 0000000000..f9c35ccfca
--- /dev/null
+++ b/scripts/signrom.py
@@ -0,0 +1,40 @@
+#
+# Option ROM signing utility
+#
+# Authors:
+# Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or later.
+# See the COPYING file in the top-level directory.
+
+import sys
+import struct
+
+if len(sys.argv) < 3:
+ print('usage: signrom.py input output')
+ sys.exit(1)
+
+fin = open(sys.argv[1], 'rb')
+fout = open(sys.argv[2], 'wb')
+
+fin.seek(2)
+size = ord(fin.read(1)) * 512 - 1
+
+fin.seek(0)
+data = fin.read(size)
+fout.write(data)
+
+checksum = 0
+for b in data:
+ # catch Python 2 vs. 3 differences
+ if isinstance(b, int):
+ checksum += b
+ else:
+ checksum += ord(b)
+checksum = (256 - checksum) % 256
+
+# Python 3 no longer allows chr(checksum)
+fout.write(struct.pack('B', checksum))
+
+fin.close()
+fout.close()