build_yobikomi_spi.py

import struct

"""
FILE STRUCTURE:

[GLOBALHEADER]
-PADDING with 0xFF-
[MUSIC HEADER 01]
-PADDING with 0xFF-
[MUSIC DATA 01]
-PADDING with 0xFF-
[MUSIC HEADER 02]
-PADDING with 0xFF-
[MUSIC DATA 02]
-PADDING with 0xFF-
EOF.


GLOBAL HEADER STRUCTURE:
 [MAGIC, 4bytes] : AA 55 01 00
 [UNKNOWN DATA, 12bytes] : 00 01 64 00 00 00 00 00 01 00 02 00
 [ADDRESS OF MUSIC HEADER 01, 4bytes, LITTLE]
 [ADDRESS OF MUSIC HEADER 02, 4bytes, LITTLE]

MUSIC HEADER STRUCTURE:
 [MAGIC, 4bytes] : 55 AA 01 00
 [UNKNOWN DATA, 4bytes] : 00 80 FF FF
 [ADDRESS OF MUSIC DATA, 4bytes, LITTLE]
 [LAST ADDRESS OF MUSIC DATA, 4bytes, LITTLE] 

HOW TO MAKE MUSIC DATA:
 # ffmpeg -i sound1.wav -acodec adpcm_ima_ssi -f s8 sound1.vox

"""

def make_globalheader(ptr_music01, ptr_music02):
    data = b'\xAA\x55\x01\x00' # MAGIC
    data += b'\x00\x01\x64\x00\x00\x00\x00\x00\x01\x00\x02\x00' # UNKNOWN DATA
    data += struct.pack("<l",ptr_music01)
    data += struct.pack("<l",ptr_music02)
    return data

def make_musicdata(baseaddr, musicdata):
    padding = 0x200

    data = b'\x55\xAA\x01\x00'  # MAGIC
    data += b'\x00\x80\xFF\xFF' # UNKNOWN DATA
    data += struct.pack("<l",baseaddr + padding) # ADDRESS
    data += struct.pack("<l",baseaddr + padding + len(musicdata)) # LAST ADDRESS
    data += b'\xFF' * (padding - 0x10)
    data += musicdata
    return data

def main():
    padding = 0x200
    baseaddr = 0x100

    with open("sound1.vox", "rb") as f:
        music01 = make_musicdata(baseaddr,f.read())
    with open("sound2.vox", "rb") as f:
        music02 = make_musicdata(baseaddr + padding + len(music01),f.read())

    global_header = make_globalheader(baseaddr,baseaddr + padding + len(music01))
    
    data = global_header
    data += b"\xFF" * (baseaddr - len(global_header))
    data += music01
    data += b'\xFF' * padding
    data += music02
    data += b'\xFF' * padding

    with open("firmdata.bin","wb") as f:
        f.write(data)
        f.flush()


if __name__ == "__main__":
    main()