Strip everything but the kits from an LSDJ ROM; written so I can use it in tests

strip_kits_from_rom.py

#!/usr/bin/env python

import sys

with open(sys.argv[1], 'rb') as in_fp:
    in_fp.seek(0x20000)

    with open('lsdj.gb.patched', 'wb') as out_fp:
        out_fp.write(bytearray([0xff] * 0x20000))
        out_fp.write(in_fp.read(21 * (0x4000)))
        out_fp.write(bytearray([0xff] * (0x100000 - 0x20000 - 21 * 0x4000)))