SummerCart64/sw/pc/dd64.py
2022-08-29 01:15:39 +02:00

228 lines
8.3 KiB
Python
Executable File

#!/usr/bin/env python3
import sys
from io import BufferedReader
from typing import Optional
class BadBlockError(Exception):
pass
class DD64Image:
__DISK_HEADS = 2
__DISK_TRACKS = 1175
__DISK_BLOCKS_PER_TRACK = 2
__DISK_SECTORS_PER_BLOCK = 85
__DISK_BAD_TRACKS_PER_ZONE = 12
__DISK_SYSTEM_SECTOR_SIZE = 232
__DISK_ZONES = [
(0, 232, 158, 0),
(0, 216, 158, 158),
(0, 208, 149, 316),
(0, 192, 149, 465),
(0, 176, 149, 614),
(0, 160, 149, 763),
(0, 144, 149, 912),
(0, 128, 114, 1061),
(1, 216, 158, 157),
(1, 208, 158, 315),
(1, 192, 149, 464),
(1, 176, 149, 613),
(1, 160, 149, 762),
(1, 144, 149, 911),
(1, 128, 149, 1060),
(1, 112, 114, 1174),
]
__DISK_VZONE_TO_PZONE = [
[0, 1, 2, 9, 8, 3, 4, 5, 6, 7, 15, 14, 13, 12, 11, 10],
[0, 1, 2, 3, 10, 9, 8, 4, 5, 6, 7, 15, 14, 13, 12, 11],
[0, 1, 2, 3, 4, 11, 10, 9, 8, 5, 6, 7, 15, 14, 13, 12],
[0, 1, 2, 3, 4, 5, 12, 11, 10, 9, 8, 6, 7, 15, 14, 13],
[0, 1, 2, 3, 4, 5, 6, 13, 12, 11, 10, 9, 8, 7, 15, 14],
[0, 1, 2, 3, 4, 5, 6, 7, 14, 13, 12, 11, 10, 9, 8, 15],
[0, 1, 2, 3, 4, 5, 6, 7, 15, 14, 13, 12, 11, 10, 9, 8],
]
__DISK_DRIVE_TYPES = [(
'development',
192,
[11, 10, 3, 2],
[0, 1, 8, 9, 16, 17, 18, 19, 20, 21, 22, 23],
), (
'retail',
232,
[9, 8, 1, 0],
[2, 3, 10, 11, 12, 16, 17, 18, 19, 20, 21, 22, 23],
)]
__file: Optional[BufferedReader]
__drive_type: Optional[str]
__block_info_table: list[tuple[int, int]]
loaded: bool = False
def __init__(self) -> None:
self.__file = None
self.__drive_type = None
block_info_table_length = self.__DISK_HEADS * self.__DISK_TRACKS * self.__DISK_BLOCKS_PER_TRACK
self.__block_info_table = [None] * block_info_table_length
def __del__(self) -> None:
self.unload()
def __check_system_block(self, lba: int, sector_size: int, check_disk_type: bool) -> tuple[bool, bytes]:
self.__file.seek(lba * self.__DISK_SYSTEM_SECTOR_SIZE * self.__DISK_SECTORS_PER_BLOCK)
system_block_data = self.__file.read(sector_size * self.__DISK_SECTORS_PER_BLOCK)
system_data = system_block_data[:sector_size]
for sector in range(1, self.__DISK_SECTORS_PER_BLOCK):
sector_data = system_block_data[(sector * sector_size):][:sector_size]
if (system_data != sector_data):
return (False, None)
if (check_disk_type):
if (system_data[4] != 0x10):
return (False, None)
if ((system_data[5] & 0xF0) != 0x10):
return (False, None)
return (True, system_data)
def __parse_disk(self) -> None:
disk_system_data = None
disk_id_data = None
disk_bad_lbas = []
drive_index = 0
while (disk_system_data == None) and (drive_index < len(self.__DISK_DRIVE_TYPES)):
(drive_type, system_sector_size, system_data_lbas, bad_lbas) = self.__DISK_DRIVE_TYPES[drive_index]
disk_bad_lbas.clear()
disk_bad_lbas.extend(bad_lbas)
for system_lba in system_data_lbas:
(valid, system_data) = self.__check_system_block(system_lba, system_sector_size, check_disk_type=True)
if (valid):
self.__drive_type = drive_type
disk_system_data = system_data
else:
disk_bad_lbas.append(system_lba)
drive_index += 1
for id_lba in [15, 14]:
(valid, id_data) = self.__check_system_block(id_lba, self.__DISK_SYSTEM_SECTOR_SIZE, check_disk_type=False)
if (valid):
disk_id_data = id_data
else:
disk_bad_lbas.append(id_lba)
if not (disk_system_data and disk_id_data):
raise ValueError('Provided 64DD disk file is not valid')
disk_zone_bad_tracks = []
for zone in range(len(self.__DISK_ZONES)):
zone_bad_tracks = []
start = 0 if zone == 0 else system_data[0x07 + zone]
stop = system_data[0x07 + zone + 1]
for offset in range(start, stop):
zone_bad_tracks.append(system_data[0x20 + offset])
for ignored_track in range(self.__DISK_BAD_TRACKS_PER_ZONE - len(zone_bad_tracks)):
zone_bad_tracks.append(self.__DISK_ZONES[zone][2] - ignored_track - 1)
disk_zone_bad_tracks.append(zone_bad_tracks)
disk_type = disk_system_data[5] & 0x0F
current_lba = 0
starting_block = 0
disk_file_offset = 0
for zone in self.__DISK_VZONE_TO_PZONE[disk_type]:
(head, sector_size, tracks, track) = self.__DISK_ZONES[zone]
for zone_track in range(tracks):
current_zone_track = (
(tracks - 1) - zone_track) if head else zone_track
if (current_zone_track in disk_zone_bad_tracks[zone]):
track += (-1) if head else 1
continue
for block in range(self.__DISK_BLOCKS_PER_TRACK):
index = (track << 2) | (head << 1) | (starting_block ^ block)
if (current_lba not in disk_bad_lbas):
self.__block_info_table[index] = (disk_file_offset, sector_size * self.__DISK_SECTORS_PER_BLOCK)
else:
self.__block_info_table[index] = None
disk_file_offset += sector_size * self.__DISK_SECTORS_PER_BLOCK
current_lba += 1
track += (-1) if head else 1
starting_block ^= 1
def __check_track_head_block(self, track: int, head: int, block: int) -> None:
if (track < 0 or track >= self.__DISK_TRACKS):
raise ValueError('Track outside of possible range')
if (head < 0 or head >= self.__DISK_HEADS):
raise ValueError('Head outside of possible range')
if (block < 0 or block >= self.__DISK_BLOCKS_PER_TRACK):
raise ValueError('Block outside of possible range')
def __get_table_index(self, track: int, head: int, block: int) -> int:
return (track << 2) | (head << 1) | (block)
def __get_block_info(self, track: int, head: int, block: int) -> Optional[tuple[int, int]]:
if (self.__file.closed):
return None
self.__check_track_head_block(track, head, block)
index = self.__get_table_index(track, head, block)
return self.__block_info_table[index]
def load(self, path: str) -> None:
self.unload()
self.__file = open(path, 'rb+')
self.__parse_disk()
self.loaded = True
def unload(self) -> None:
self.loaded = False
if (self.__file != None and not self.__file.closed):
self.__file.close()
self.__drive_type = None
def get_drive_type(self) -> str:
return self.__drive_type
def read_block(self, track: int, head: int, block: int) -> bytes:
info = self.__get_block_info(track, head, block)
if (info == None):
raise BadBlockError
(offset, block_size) = info
self.__file.seek(offset)
return self.__file.read(block_size)
def write_block(self, track: int, head: int, block: int, data: bytes) -> None:
info = self.__get_block_info(track, head, block)
if (info == None):
raise BadBlockError
(offset, block_size) = info
if (len(data) != block_size):
raise ValueError(f'Provided data block size is different than expected ({len(data)} != {block_size})')
self.__file.seek(offset)
self.__file.write(data)
if __name__ == '__main__':
id_lba_locations = [
(7, 0, 1),
(7, 0, 0)
]
if (len(sys.argv) >= 2):
dd = DD64Image()
dd.load(sys.argv[1])
print(dd.get_drive_type())
for (track, head, block) in id_lba_locations:
try:
print(dd.read_block(track, head, block)[:4])
except BadBlockError:
print(f'Bad ID block [track: {track}, head: {head}, block: {block}]')
dd.unload()
else:
print(f'[{sys.argv[0]}]: Expected disk image path as first argument')