[Qemu-devel] [PULL 17/24] scripts/signrom.py: Check for magic in option ROMs.

[Paolo Bonzini <pbonzini@redhat.com>]

From: "Richard W.M. Jones" <rjones@redhat.com>

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>
---
 scripts/signrom.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/signrom.py b/scripts/signrom.py
index 6c8b9bf..5629bca 100644
--- 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)
 
-- 
1.8.3.1