This page hosts a formal specification of APM (Apple Partition Map) partition table using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = ApmPartitionTable.from_file("path/to/local/file.bin")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = ApmPartitionTable(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.sector_size # => 0x200 (512) bytes for disks, 0x1000 (4096) bytes is not supported by APM
0x800 (2048) bytes for CDROM
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class ApmPartitionTable(KaitaiStruct):
"""
.. seealso::
Source - https://en.wikipedia.org/wiki/Apple_Partition_Map
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
pass
class PartitionEntry(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.magic = self._io.read_bytes(2)
if not self.magic == b"\x50\x4D":
raise kaitaistruct.ValidationNotEqualError(b"\x50\x4D", self.magic, self._io, u"/types/partition_entry/seq/0")
self.reserved_1 = self._io.read_bytes(2)
self.number_of_partitions = self._io.read_u4be()
self.partition_start = self._io.read_u4be()
self.partition_size = self._io.read_u4be()
self.partition_name = (KaitaiStream.bytes_terminate(self._io.read_bytes(32), 0, False)).decode(u"ascii")
self.partition_type = (KaitaiStream.bytes_terminate(self._io.read_bytes(32), 0, False)).decode(u"ascii")
self.data_start = self._io.read_u4be()
self.data_size = self._io.read_u4be()
self.partition_status = self._io.read_u4be()
self.boot_code_start = self._io.read_u4be()
self.boot_code_size = self._io.read_u4be()
self.boot_loader_address = self._io.read_u4be()
self.reserved_2 = self._io.read_bytes(4)
self.boot_code_entry = self._io.read_u4be()
self.reserved_3 = self._io.read_bytes(4)
self.boot_code_cksum = self._io.read_u4be()
self.processor_type = (KaitaiStream.bytes_terminate(self._io.read_bytes(16), 0, False)).decode(u"ascii")
@property
def partition(self):
if hasattr(self, '_m_partition'):
return self._m_partition
if (self.partition_status & 1) != 0:
io = self._root._io
_pos = io.pos()
io.seek((self.partition_start * self._root.sector_size))
self._m_partition = io.read_bytes((self.partition_size * self._root.sector_size))
io.seek(_pos)
return getattr(self, '_m_partition', None)
@property
def data(self):
if hasattr(self, '_m_data'):
return self._m_data
io = self._root._io
_pos = io.pos()
io.seek((self.data_start * self._root.sector_size))
self._m_data = io.read_bytes((self.data_size * self._root.sector_size))
io.seek(_pos)
return getattr(self, '_m_data', None)
@property
def boot_code(self):
if hasattr(self, '_m_boot_code'):
return self._m_boot_code
io = self._root._io
_pos = io.pos()
io.seek((self.boot_code_start * self._root.sector_size))
self._m_boot_code = io.read_bytes(self.boot_code_size)
io.seek(_pos)
return getattr(self, '_m_boot_code', None)
@property
def sector_size(self):
"""0x200 (512) bytes for disks, 0x1000 (4096) bytes is not supported by APM
0x800 (2048) bytes for CDROM
"""
if hasattr(self, '_m_sector_size'):
return self._m_sector_size
self._m_sector_size = 512
return getattr(self, '_m_sector_size', None)
@property
def partition_lookup(self):
"""Every partition entry contains the number of partition entries.
We parse the first entry, to know how many to parse, including the first one.
No logic is given what to do if other entries have a different number.
"""
if hasattr(self, '_m_partition_lookup'):
return self._m_partition_lookup
io = self._root._io
_pos = io.pos()
io.seek(self._root.sector_size)
self._raw__m_partition_lookup = io.read_bytes(self.sector_size)
_io__raw__m_partition_lookup = KaitaiStream(BytesIO(self._raw__m_partition_lookup))
self._m_partition_lookup = ApmPartitionTable.PartitionEntry(_io__raw__m_partition_lookup, self, self._root)
io.seek(_pos)
return getattr(self, '_m_partition_lookup', None)
@property
def partition_entries(self):
if hasattr(self, '_m_partition_entries'):
return self._m_partition_entries
io = self._root._io
_pos = io.pos()
io.seek(self._root.sector_size)
self._raw__m_partition_entries = []
self._m_partition_entries = []
for i in range(self._root.partition_lookup.number_of_partitions):
self._raw__m_partition_entries.append(io.read_bytes(self.sector_size))
_io__raw__m_partition_entries = KaitaiStream(BytesIO(self._raw__m_partition_entries[i]))
self._m_partition_entries.append(ApmPartitionTable.PartitionEntry(_io__raw__m_partition_entries, self, self._root))
io.seek(_pos)
return getattr(self, '_m_partition_entries', None)