toaruos/util/iso.py

576 lines
20 KiB
Python
Executable File

#!/usr/bin/env python3
"""
Tool for creating ISO 9660 CD images.
"""
import array
import struct
class Structure(object):
assert_size = -1
def __init__(self):
self.data = {}
for field in self.fields:
if len(field) > 2:
f, s, d = field
self.data[s] = d
else:
f, s = field
if f.endswith('s'):
self.data[s] = b""
else:
self.data[s] = 0
if self.assert_size != -1:
assert(len(self) == self.assert_size)
def __len__(self):
return sum([struct.calcsize(f[0]) for f in self.fields])
def read(self, data, offset):
def read_struct(fmt,buf,offset):
out, = struct.unpack_from(fmt,buf,offset)
return out, offset + struct.calcsize(fmt)
o = offset
for field in self.fields:
if len(field) > 2:
f, s, _ = field
else:
f, s = field
self.data[s], o = read_struct(f, data, o)
return o
def write(self, data, offset):
def write_struct(fmt, buf, offset, value):
struct.pack_into(fmt, buf, offset, value)
return offset + struct.calcsize(fmt)
o = offset
for field in self.fields:
if len(field) > 2:
f, s, _ = field
else:
f, s = field
o = write_struct(f,data,o,self.data[s])
return o
def read_struct(fmt,buf,offset):
out, = struct.unpack_from(fmt,buf,offset)
return out, offset + struct.calcsize(fmt)
class FAT(object):
def __init__(self, iso, offset):
self.iso = iso
self.offset = offset
self.bytespersector, _ = read_struct('H', self.iso.data, offset + 11)
self.sectorspercluster, _ = read_struct('B', self.iso.data, offset + 13)
self.reservedsectors, _ = read_struct('H', self.iso.data, offset + 14)
self.numberoffats, _ = read_struct('B', self.iso.data, offset + 16)
self.numberofdirs, _ = read_struct('H', self.iso.data, offset + 17)
self.fatsize, _ = read_struct('H', self.iso.data, offset + 22)
self.root_dir_sectors = (self.numberofdirs * 32 + (self.bytespersector - 1)) // self.bytespersector
self.first_data_sector = self.reservedsectors + (self.numberoffats * self.fatsize) + self.root_dir_sectors
self.root_sector= self.first_data_sector - self.root_dir_sectors
self.root = FATDirectory(self, self.offset + self.root_sector * self.bytespersector)
def get_offset(self, cluster):
return self.offset + ((cluster - 2) * self.sectorspercluster + self.first_data_sector) * self.bytespersector
def get_file(self, path):
units = path.split('/')
units = units[1:]
me = self.root
out = None
for i in units:
for fatfile in me.list():
if fatfile.readable_name() == i:
me = fatfile.to_dir()
out = fatfile
break
else:
return None
return out
class FATDirectory(object):
def __init__(self, fat, offset):
self.fat = fat
self.offset = offset
def list(self):
o = self.offset
while 1:
out = FATFile(self.fat, o)
if out.name != '\0\0\0\0\0\0\0\0':
yield out
else:
break
o += out.size
class FATFile(object):
def __init__(self, fat, offset):
self.fat = fat
self.offset = offset
self.magic_long = None
self.size = 0
self.long_name = ''
o = self.offset
self.actual_offset = o
self.attrib, _ = read_struct('B',self.fat.iso.data,o+11)
while (self.attrib & 0x0F) == 0x0F:
# Long file name entry
tmp = read_struct('10s',self.fat.iso.data,o+1)[0]
tmp += read_struct('12s',self.fat.iso.data,o+14)[0]
tmp += read_struct('4s',self.fat.iso.data,o+28)[0]
tmp = "".join([chr(x) for x in tmp[::2] if x != '\xFF']).strip('\x00')
self.long_name = tmp + self.long_name
self.size += 32
o = self.offset + self.size
self.actual_offset = o
self.attrib, _ = read_struct('B',self.fat.iso.data,o+11)
o = self.offset + self.size
self.name, o = read_struct('8s',self.fat.iso.data,o)
self.ext, o = read_struct('3s',self.fat.iso.data,o)
self.attrib, o = read_struct('B',self.fat.iso.data,o)
self.userattrib, o = read_struct('B',self.fat.iso.data,o)
self.undelete, o = read_struct('b',self.fat.iso.data,o)
self.createtime, o = read_struct('H',self.fat.iso.data,o)
self.createdate, o = read_struct('H',self.fat.iso.data,o)
self.accessdate, o = read_struct('H',self.fat.iso.data,o)
self.clusterhi, o = read_struct('H',self.fat.iso.data,o)
self.modifiedti, o = read_struct('H',self.fat.iso.data,o)
self.modifiedda, o = read_struct('H',self.fat.iso.data,o)
self.clusterlow, o = read_struct('H',self.fat.iso.data,o)
self.filesize, o = read_struct('I',self.fat.iso.data,o)
self.name = self.name.decode('ascii')
self.ext = self.ext.decode('ascii')
self.size += 32
self.cluster = (self.clusterhi << 16) + self.clusterlow
def is_dir(self):
return bool(self.attrib & 0x10)
def is_long(self):
return bool((self.attrib & 0x0F) == 0x0F)
def to_dir(self):
return FATDirectory(self.fat, self.fat.get_offset(self.cluster))
def get_offset(self):
return self.fat.get_offset(self.cluster)
def readable_name(self):
if self.long_name:
return self.long_name
if self.ext.strip():
return (self.name.strip() + '.' + self.ext.strip()).lower()
else:
return self.name.strip().lower()
def make_time():
data = array.array('b',b'\0'*17)
struct.pack_into(
'4s2s2s2s2s2s2sb',
data, 0,
b'2018', b'11', b'14', # Year, Month, Day
b'12', b'00', b'00', # Hour, Minute, Second
b'00', # Hundreths
0, # Offset
)
return bytes(data)
def make_date():
data = array.array('b',b'\0'*7)
struct.pack_into(
'BBBBBBb',
data, 0,
118, 11, 14,
12, 0, 0,
0,
)
return bytes(data)
class ISOBootRecord(Structure):
assert_size = 2048
fields = (
('B', 'type_code', 0),
('5s', 'cd001', b'CD001'),
('B', 'version', 1),
('32s', 'boot_system_identifier'),
('32s', 'boot_identifier'),
('1977s', 'boot_record_data'),
)
class ISOElToritoBootRecord(ISOBootRecord):
assert_size = 2048
fields = (
('B', 'type_code', 0),
('5s', 'cd001', b'CD001'),
('B', 'version', 1),
('32s', 'boot_system_identifier',b'EL TORITO SPECIFICATION'),
('32s', 'boot_identifier'),
('<I', 'catalog_lba'),
('1973s', 'boot_record_data'),
)
def set_catalog(self, catalog_lba):
self.data['catalog_lba'] = catalog_lba
class ISOPrimaryVolumeDescriptor(Structure):
assert_size = 2048
fields = (
('B', 'type_code', 1),
('5s', 'cd001', b'CD001'),
('B', 'version', 1),
('B', 'unused_0', 0),
('32s', 'system_id', b' '*32),
('32s', 'volume_id', b'ToaruOS Boot CD'.ljust(32)),
('8s', 'unused_1', b'\0'*8),
('<I', 'volume_space_lsb'),
('>I', 'volume_space_msb'),
('32s', 'unused_2', b'\0'*32),
('<H', 'volume_set_size_lsb', 1),
('>H', 'volume_set_size_msb', 1),
('<H', 'volume_sequence_lsb', 1),
('>H', 'volume_sequence_msb', 1),
('<H', 'logical_block_size_lsb', 2048),
('>H', 'logical_block_size_msb', 2048),
('<I', 'path_table_size_lsb'),
('>I', 'path_table_size_msb'),
('<I', 'type_l_table_lsb'),
('<I', 'optional_type_l_table_lsb'),
('>I', 'type_m_table_msb'),
('>I', 'optional_type_m_table_msb'),
('34s', 'root_entry_data'),
('128s', 'volume_set_identifier', b' '*128),
('128s', 'publisher_identifier', b' '*128),
('128s', 'data_preparer_identifier', b' '*128),
('128s', 'application_identifier',b' '*128),
('38s', 'copyright_file_identifier',b' '*38),
('36s', 'abstract_file_identifier',b' '*36),
('37s', 'bibliographic_file_identifier',b' '*37),
('17s', 'volume_creation_time',make_time()),
('17s', 'volume_modification_time',make_time()),
('17s', 'volume_expiration_time',make_time()),
('17s', 'volume_effective_time',make_time()),
('B', 'file_structure_version'),
('B', 'unused_3', 0),
('512s', 'application_data'),
('653s', 'reserved', b'\0'*653),
)
class ISOVolumeDescriptorSetTerminator(Structure):
assert_size = 2048
fields = (
('B', 'type_code', 0xFF),
('5s', 'cd001', b'CD001'),
('B', 'version', 1),
('2041s', 'unused', b'\0'*2041)
)
class ISODirectoryEntry(Structure):
assert_size = 33
fields = (
('B', 'length'),
('B', 'ext_length'),
('<I', 'extent_start_lsb'),
('>I', 'extent_start_msb'),
('<I', 'extent_length_lsb'),
('>I', 'extent_length_msb'),
('7s', 'record_date', make_date()),
('B', 'flags'),
('B', 'interleave_units'),
('B', 'interleave_gap'),
('<H', 'volume_seq_lsb'),
('>H', 'volume_seq_msb'),
('B', 'name_len'),
)
def set_name(self, name):
self.data['name_len'] = len(name)
self.name = name
self.data['length'] = self.assert_size + len(self.name)
if self.data['length'] % 2:
self.data['length'] += 1
def set_extent(self, start, length):
self.data['extent_start_lsb'] = start
self.data['extent_start_msb'] = start
self.data['extent_length_lsb'] = length
self.data['extent_length_msb'] = length
def write(self, data, offset):
o = super(ISODirectoryEntry,self).write(data,offset)
struct.pack_into(str(len(self.name))+'s', data, o, self.name.encode('utf-8'))
return offset + self.data['length']
class ArbitraryData(object):
def __init__(self, path=None, size=None):
if path:
with open(path,'rb') as f:
tmp = f.read()
self.data = array.array('b',tmp)
elif size:
self.data = array.array('b',b'\0'*size)
else:
raise ValueError("Expected one of path or size to be set.")
self.size = len(self.data.tobytes())
self.actual_size = self.size
while (self.size % 2048):
self.size += 1
def write(self, data, offset):
struct.pack_into(str(self.size) + 's', data, offset, self.data.tobytes())
return offset + self.size
def make_entry():
return b'\0'*34
class ISO9660(object):
def __init__(self, from_file=None):
self.primary_volume_descriptor = ISOPrimaryVolumeDescriptor()
self.boot_record = ISOElToritoBootRecord()
self.volume_descriptor_set_terminator = ISOVolumeDescriptorSetTerminator()
self.el_torito_catalog = ElToritoCatalog()
self.allocate = 0x13
if from_file:
# Only for a file we produced.
with open(from_file, 'rb') as f:
tmp = f.read()
data = array.array('b', tmp)
self.primary_volume_descriptor.read(data, 0x10 * 2048)
self.boot_record.read(data, 0x11 * 2048)
self.volume_descriptor_set_terminator.read(data, 0x12 * 2048)
self.el_torito_catalog.read(data, self.boot_record.data['catalog_lba'] * 2048)
else:
# Root directory
self.root = ISODirectoryEntry()
self.root.data['flags'] = 0x02 # Directory
self.root.set_name(' ')
self.root_data = ArbitraryData(size=2048)
self.root_data.sector_offset = self.allocate_space(1)
self.root.set_extent(self.root_data.sector_offset,self.root_data.size)
# Dummy entries
t = ISODirectoryEntry()
t.set_name('')
o = t.write(self.root_data.data, 0)
t = ISODirectoryEntry()
t.set_name('\1')
o = t.write(self.root_data.data, o)
# Fat data
self.fat_payload = ArbitraryData(path='cdrom/fat.img')
self.fat_payload.sector_offset = self.allocate_space(self.fat_payload.size // 2048)
self.fat = FAT(self.fat_payload, 0)
self.fat_entry = ISODirectoryEntry()
self.fat_entry.set_name('FAT.IMG')
self.fat_entry.set_extent(self.fat_payload.sector_offset, self.fat_payload.actual_size)
o = self.fat_entry.write(self.root_data.data, o)
# Kernel
self.kernel_entry = ISODirectoryEntry()
self.kernel_entry.set_name('KERNEL.')
f = self.fat.get_file('/kernel')
self.kernel_entry.set_extent(f.get_offset() // 2048 + self.fat_payload.sector_offset, f.filesize)
o = self.kernel_entry.write(self.root_data.data, o)
# Ramdisk
self.ramdisk_entry = ISODirectoryEntry()
self.ramdisk_entry.set_name('RAMDISK.IMG')
f = self.fat.get_file('/ramdisk.img')
self.ramdisk_entry.set_extent(f.get_offset() // 2048 + self.fat_payload.sector_offset, f.filesize)
o = self.ramdisk_entry.write(self.root_data.data, o)
# Modules directory
self.mods_data = ArbitraryData(size=(2048*2)) # Just in case
self.mods_data.sector_offset = self.allocate_space(self.mods_data.size // 2048)
self.mods_entry = ISODirectoryEntry()
self.mods_entry.data['flags'] = 0x02
self.mods_entry.set_name('MOD')
self.mods_entry.set_extent(self.mods_data.sector_offset, self.mods_data.actual_size)
o = self.mods_entry.write(self.root_data.data, o)
# Modules themselves
t = ISODirectoryEntry()
t.set_name('')
o = t.write(self.mods_data.data, 0)
t = ISODirectoryEntry()
t.set_name('\1')
o = t.write(self.mods_data.data, o)
for mod_file in [
'fatbase/mod/ac97.ko',
'fatbase/mod/ata.ko',
'fatbase/mod/ataold.ko',
'fatbase/mod/debug_sh.ko',
'fatbase/mod/dospart.ko',
'fatbase/mod/e1000.ko',
'fatbase/mod/ext2.ko',
'fatbase/mod/hda.ko',
'fatbase/mod/iso9660.ko',
'fatbase/mod/lfbvideo.ko',
'fatbase/mod/net.ko',
'fatbase/mod/packetfs.ko',
'fatbase/mod/pcnet.ko',
'fatbase/mod/pcspkr.ko',
'fatbase/mod/portio.ko',
'fatbase/mod/procfs.ko',
'fatbase/mod/ps2kbd.ko',
'fatbase/mod/ps2mouse.ko',
'fatbase/mod/random.ko',
'fatbase/mod/rtl.ko',
'fatbase/mod/serial.ko',
'fatbase/mod/snd.ko',
'fatbase/mod/tmpfs.ko',
'fatbase/mod/usbuhci.ko',
'fatbase/mod/vbox.ko',
'fatbase/mod/vgadbg.ko',
'fatbase/mod/vgalog.ko',
'fatbase/mod/vidset.ko',
'fatbase/mod/vmware.ko',
'fatbase/mod/xtest.ko',
'fatbase/mod/zero.ko',
]:
entry = ISODirectoryEntry()
entry.set_name(mod_file.replace('fatbase/mod/','').upper())
f = self.fat.get_file('/'+mod_file.replace('fatbase/',''))
if not f:
print("didn't find",mod_file,"in fat")
continue
entry.set_extent(f.get_offset() // 2048 + self.fat_payload.sector_offset, f.filesize)
o = entry.write(self.mods_data.data, o)
# Set up the boot catalog and records
self.el_torito_catalog.sector_offset = self.allocate_space(1)
self.boot_record.set_catalog(self.el_torito_catalog.sector_offset)
self.boot_payload = ArbitraryData(path='cdrom/boot.sys')
self.boot_payload.sector_offset = self.allocate_space(self.boot_payload.size // 2048)
self.el_torito_catalog.initial_entry.data['sector_count'] = self.boot_payload.size // 512
self.el_torito_catalog.initial_entry.data['load_rba'] = self.boot_payload.sector_offset
self.el_torito_catalog.section.data['sector_count'] = 0 # Expected to be 0 or 1 for "until end of CD"
self.el_torito_catalog.section.data['load_rba'] = self.fat_payload.sector_offset
self.primary_volume_descriptor.data['root_entry_data'] = make_entry()
def allocate_space(self, sectors):
out = self.allocate
self.allocate += sectors
return out
def write(self, file_name):
with open(file_name, 'wb') as f:
data = array.array('b',b'\0'*(2048*self.allocate))
self.primary_volume_descriptor.write(data,0x10 * 2048)
self.root.write(data,0x10*2048 + 156)
self.boot_record.write(data,0x11 * 2048)
self.mods_data.write(data, self.mods_data.sector_offset * 2048)
self.root_data.write(data,self.root_data.sector_offset * 2048)
self.volume_descriptor_set_terminator.write(data,0x12 * 2048)
self.el_torito_catalog.write(data,self.el_torito_catalog.sector_offset * 2048)
self.boot_payload.write(data,self.boot_payload.sector_offset * 2048)
self.fat_payload.write(data,self.fat_payload.sector_offset * 2048)
data.tofile(f)
class ElToritoValidationEntry(Structure):
assert_size = 0x20
fields = (
('B','header_id',1),
('B','platform_id',0),
('<H','reserved_0'),
('24s','id_str',b'\0'*24),
('<H','checksum',0x55aa),
('B','key_55',0x55),
('B','key_aa',0xaa),
)
class ElToritoInitialEntry(Structure):
assert_size = 0x20
fields = (
('B','bootable',0x88),
('B','media_type'),
('<H','load_segment'),
('B','system_type'),
('B','unused_0'),
('<H','sector_count'),
('<I','load_rba'),
('20s','unused_1',b'\0'*20),
)
class ElToritoSectionHeader(Structure):
assert_size = 0x20
fields = (
('B','header_id',0x91),
('B','platform_id',0xEF),
('<H','sections',1),
('28s','id_str',b'\0'*28)
)
class ElToritoSectionEntry(Structure):
assert_size = 0x20
fields = (
('B','bootable',0x88),
('B','media_type'),
('<H','load_segment'),
('B','system_type'),
('B','unused_0'),
('<H','sector_count'),
('<I','load_rba'),
('B','selection_criteria'),
('19s','vendor'),
)
class ElToritoCatalog(object):
def __init__(self):
self.validation_entry = ElToritoValidationEntry()
self.initial_entry = ElToritoInitialEntry()
self.section_header = ElToritoSectionHeader()
self.section = ElToritoSectionEntry()
def read(self, data, offset):
o = offset
o = self.validation_entry.read(data, o)
o = self.initial_entry.read(data, o)
o = self.section_header.read(data, o)
o = self.section.read(data, o)
def write(self, data, offset):
o = offset
o = self.validation_entry.write(data, o)
o = self.initial_entry.write(data, o)
o = self.section_header.write(data, o)
o = self.section.write(data, o)
iso = ISO9660()
#print(iso.el_torito_catalog.validation_entry.data)
#print(iso.el_torito_catalog.initial_entry.data)
#print(iso.el_torito_catalog.section_header.data)
#print(iso.el_torito_catalog.section.data)
iso.write('test.iso')