def METHOD_NAME(self, offset, hexfile):
    """Efinix has a simple 'one line per byte, HEX-encoded' bitstream file"""
    with open(hexfile, 'r') as f:
        hexfile = f.read()
    lines = hexfile.split('\n')
    while lines[-1] == '':
        lines = lines[:-1]
    payload = [int(l[0:2], 16) for l in lines]
    length = len(payload)
    self._expand_to_offset(offset)
    self.payload[offset:+length] = payload