scripts/signrom.py: Check for magic in option ROMs.

Because of the risk that compilers might not emit the asm() block at
the beginning of the option ROM, check that the ROM contains the
required magic signature.

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <1463000807-18015-3-git-send-email-rjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/scripts/signrom.py b/scripts/signrom.py
index 6c8b9bf40653c82c729b9af1e1ff48664346692a..5629bca222cae7754fe363e43e07e5818d2caf24 100644 (file)
--- a/scripts/signrom.py
+++ b/scripts/signrom.py
@@ -17,7 +17,10 @@ if len(sys.argv) < 3:
 fin = open(sys.argv[1], 'rb')
 fout = open(sys.argv[2], 'wb')
 
-fin.seek(2)
+magic = fin.read(2)
+if magic != '\x55\xaa':
+    sys.exit("%s: option ROM does not begin with magic 55 aa" % sys.argv[1])
+
 size_byte = ord(fin.read(1))
 fin.seek(0)