Commit 6f71b779 authored by Richard W.M. Jones's avatar Richard W.M. Jones Committed by Paolo Bonzini
Browse files

scripts/signrom.py: Allow option ROM checksum script to write the size header. 



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: default avatarRichard W.M. Jones <rjones@redhat.com>
Message-Id: <1463000807-18015-2-git-send-email-rjones@redhat.com>
parent 168340b6

scripts/signrom.py

+22 −3
Original line number Diff line number Diff line
@@ -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)



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