#!/usr/bin/env python3

"""
Basically, iterate all 16-bit numbers,
or rather, 15-bit, to have valid
nandgame instructions, skip reserved bits.
"""

import sys

# endianness = 'big'
endianness = "little"


def main():
    with open("allins.bin", "wb") as f:
        ins = 0x0000
        # ldi A, 0
        _ = f.write(ins.to_bytes(2, byteorder=endianness))

        ins = 0x00FF
        # ldi A, 255
        _ = f.write(ins.to_bytes(2, byteorder=endianness))

        for ins in range(0x8000, 0xFFFF + 1):
            # unused bytes, force 1
            if (ins & 0x6800) != 0x6800:
                continue

            f.write(ins.to_bytes(2, byteorder=endianness))


if __name__ == "__main__":
    if len(sys.argv) == 2:
        if sys.argv[1] in ["little", "le"]:
            endianness = "little"
        elif sys.argv[1] in ["big", "be"]:
            endianness = "big"
    print(f"Use Endianness: {endianness}")
    main()