Python script to create a GX4000 CPR file

cpr.py

#!/usr/bin/env python

__version__ = "1.0"

import sys
from argparse import ArgumentParser
import struct

ROM_SIZE = 32 * 1024 * 16

def main():

    cpr = [0xff for _ in range(ROM_SIZE)]

    parser = ArgumentParser(description="CPR builder",
                            epilog="Copyright (C) 2016 Juan J Martinez <jjm@usebox.net>",
                            )

    parser.add_argument("--version", action="version", version="%(prog)s "  + __version__)
    parser.add_argument("output", help="output file")
    parser.add_argument("bins", metavar="BIN", nargs="+", help="binary:addr to include in the CPR")

    args = parser.parse_args()

    for binary in args.bins:
        try:
            filename, addr = binary.split(":")
        except ValueError:
            parser.error("%r: expected binary:addr" % binary)

        if addr.startswith("0x"):
            addr = int(addr, 16)
        else:
            addr = int(addr)

        with open(filename, "rb") as fd:
            data = fd.read()

        print("Loading %r into 0x%04x" % (filename, addr))
        for i in range(len(data)):
            cpr[addr + i] = data[i]

    print("Writing %r..." % args.output)

    with open(args.output, "wb") as fd:
        fd.write("RIFF")
        # ROM size + 32 * 8 chunk headers (cbxx + length) + "AMS!"
        fd.write(struct.pack("<L", ROM_SIZE + 32 * 8 + 4))
        fd.write("AMS!")
        for i in range(32):
            fd.write("cb%02d" % i)
            fd.write(struct.pack("<L", 1024 * 16))
            ini = i * 1024 * 16
            end = (i + 1) * 1024 * 16
            fd.write(bytearray(cpr[ini:end]))

    print("Done!")

if __name__ == "__main__":
    main()