From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53104) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0YA9-0001Et-9G for qemu-devel@nongnu.org; Wed, 11 May 2016 13:43:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b0YA2-0001mR-NZ for qemu-devel@nongnu.org; Wed, 11 May 2016 13:43:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44454) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0YA2-0001mA-Gw for qemu-devel@nongnu.org; Wed, 11 May 2016 13:43:02 -0400 From: "Richard W.M. Jones" Date: Wed, 11 May 2016 18:42:53 +0100 Message-Id: <1462988574-30590-2-git-send-email-rjones@redhat.com> In-Reply-To: <1462988574-30590-1-git-send-email-rjones@redhat.com> References: <1462988574-30590-1-git-send-email-rjones@redhat.com> Subject: [Qemu-devel] [PATCH v7 1/2] scripts/signrom.py: Allow option ROM checksum script to write the size header. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: stefanha@gmail.com, marc.mari.barcelo@gmail.com, ehabkost@redhat.com, mst@redhat.com, kraxel@redhat.com, rth@twiddle.net, lersek@redhat.com, pbonzini@redhat.com Modify the signrom.py script so that if the size byte in the header is 0 (ie. not set) then the script will set the size. If the size byte is non-zero then we do the same as before, so this doesn't require changes to any existing ROM sourcecode. Signed-off-by: Richard W.M. Jones --- scripts/signrom.py | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/scripts/signrom.py b/scripts/signrom.py index f9c35cc..6c8b9bf 100644 --- a/scripts/signrom.py +++ b/scripts/signrom.py @@ -18,10 +18,29 @@ fin = open(sys.argv[1], 'rb') fout = open(sys.argv[2], 'wb') fin.seek(2) -size = ord(fin.read(1)) * 512 - 1 - +size_byte = ord(fin.read(1)) fin.seek(0) -data = fin.read(size) + +if size_byte == 0: + # If the caller left the size field blank then we will fill it in, + # also rounding the whole input to a multiple of 512 bytes. + data = fin.read() + # +1 because we need a byte to store the checksum. + size = len(data) + 1 + # Round up to next multiple of 512. + size += 511 + size -= size % 512 + if size >= 65536: + sys.exit("%s: option ROM size too large" % sys.argv[1]) + # size-1 because a final byte is added below to store the checksum. + data = data.ljust(size-1, '\0') + data = data[:2] + chr(size/512) + data[3:] +else: + # Otherwise the input file specifies the size so use it. + # -1 because we overwrite the last byte of the file with the checksum. + size = size_byte * 512 - 1 + data = fin.read(size) + fout.write(data) checksum = 0 -- 2.7.4