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vfat.py
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# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
from pkg_resources import parse_version
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if parse_version(kaitaistruct.__version__) < parse_version('0.9'):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class Vfat(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.boot_sector = Vfat.BootSector(self._io, self, self._root)
class ExtBiosParamBlockFat32(KaitaiStruct):
"""Extended BIOS Parameter Block for FAT32."""
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.ls_per_fat = self._io.read_u4le()
self.has_active_fat = self._io.read_bits_int_be(1) != 0
self.reserved1 = self._io.read_bits_int_be(3)
self.active_fat_id = self._io.read_bits_int_be(4)
self._io.align_to_byte()
self.reserved2 = self._io.read_bytes(1)
if not self.reserved2 == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.reserved2, self._io, u"/types/ext_bios_param_block_fat32/seq/4")
self.fat_version = self._io.read_u2le()
self.root_dir_start_clus = self._io.read_u4le()
self.ls_fs_info = self._io.read_u2le()
self.boot_sectors_copy_start_ls = self._io.read_u2le()
self.reserved3 = self._io.read_bytes(12)
self.phys_drive_num = self._io.read_u1()
self.reserved4 = self._io.read_u1()
self.ext_boot_sign = self._io.read_u1()
self.volume_id = self._io.read_bytes(4)
self.partition_volume_label = (KaitaiStream.bytes_strip_right(self._io.read_bytes(11), 32)).decode(u"ASCII")
self.fs_type_str = (KaitaiStream.bytes_strip_right(self._io.read_bytes(8), 32)).decode(u"ASCII")
class BootSector(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.jmp_instruction = self._io.read_bytes(3)
self.oem_name = (KaitaiStream.bytes_strip_right(self._io.read_bytes(8), 32)).decode(u"ASCII")
self.bpb = Vfat.BiosParamBlock(self._io, self, self._root)
if not (self.is_fat32):
self.ebpb_fat16 = Vfat.ExtBiosParamBlockFat16(self._io, self, self._root)
if self.is_fat32:
self.ebpb_fat32 = Vfat.ExtBiosParamBlockFat32(self._io, self, self._root)
@property
def pos_fats(self):
"""Offset of FATs in bytes from start of filesystem."""
if hasattr(self, '_m_pos_fats'):
return self._m_pos_fats if hasattr(self, '_m_pos_fats') else None
self._m_pos_fats = (self.bpb.bytes_per_ls * self.bpb.num_reserved_ls)
return self._m_pos_fats if hasattr(self, '_m_pos_fats') else None
@property
def ls_per_fat(self):
if hasattr(self, '_m_ls_per_fat'):
return self._m_ls_per_fat if hasattr(self, '_m_ls_per_fat') else None
self._m_ls_per_fat = (self.ebpb_fat32.ls_per_fat if self.is_fat32 else self.bpb.ls_per_fat)
return self._m_ls_per_fat if hasattr(self, '_m_ls_per_fat') else None
@property
def ls_per_root_dir(self):
"""Size of root directory in logical sectors.
.. seealso::
FAT: General Overview of On-Disk Format, section "FAT Data Structure"
"""
if hasattr(self, '_m_ls_per_root_dir'):
return self._m_ls_per_root_dir if hasattr(self, '_m_ls_per_root_dir') else None
self._m_ls_per_root_dir = (((self.bpb.max_root_dir_rec * 32) + self.bpb.bytes_per_ls) - 1) // self.bpb.bytes_per_ls
return self._m_ls_per_root_dir if hasattr(self, '_m_ls_per_root_dir') else None
@property
def is_fat32(self):
"""Determines if filesystem is FAT32 (true) or FAT12/16 (false)
by analyzing some preliminary conditions in BPB. Used to
determine whether we should parse post-BPB data as
`ext_bios_param_block_fat16` or `ext_bios_param_block_fat32`.
"""
if hasattr(self, '_m_is_fat32'):
return self._m_is_fat32 if hasattr(self, '_m_is_fat32') else None
self._m_is_fat32 = self.bpb.max_root_dir_rec == 0
return self._m_is_fat32 if hasattr(self, '_m_is_fat32') else None
@property
def size_fat(self):
"""Size of one FAT in bytes."""
if hasattr(self, '_m_size_fat'):
return self._m_size_fat if hasattr(self, '_m_size_fat') else None
self._m_size_fat = (self.bpb.bytes_per_ls * self.ls_per_fat)
return self._m_size_fat if hasattr(self, '_m_size_fat') else None
@property
def pos_root_dir(self):
"""Offset of root directory in bytes from start of filesystem."""
if hasattr(self, '_m_pos_root_dir'):
return self._m_pos_root_dir if hasattr(self, '_m_pos_root_dir') else None
self._m_pos_root_dir = (self.bpb.bytes_per_ls * (self.bpb.num_reserved_ls + (self.ls_per_fat * self.bpb.num_fats)))
return self._m_pos_root_dir if hasattr(self, '_m_pos_root_dir') else None
@property
def size_root_dir(self):
"""Size of root directory in bytes."""
if hasattr(self, '_m_size_root_dir'):
return self._m_size_root_dir if hasattr(self, '_m_size_root_dir') else None
self._m_size_root_dir = (self.ls_per_root_dir * self.bpb.bytes_per_ls)
return self._m_size_root_dir if hasattr(self, '_m_size_root_dir') else None
class BiosParamBlock(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.bytes_per_ls = self._io.read_u2le()
self.ls_per_clus = self._io.read_u1()
self.num_reserved_ls = self._io.read_u2le()
self.num_fats = self._io.read_u1()
self.max_root_dir_rec = self._io.read_u2le()
self.total_ls_2 = self._io.read_u2le()
self.media_code = self._io.read_u1()
self.ls_per_fat = self._io.read_u2le()
self.ps_per_track = self._io.read_u2le()
self.num_heads = self._io.read_u2le()
self.num_hidden_sectors = self._io.read_u4le()
self.total_ls_4 = self._io.read_u4le()
class RootDirectoryRec(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.file_name = self._io.read_bytes(11)
self.attribute = self._io.read_u1()
self.reserved = self._io.read_bytes(10)
self.time = self._io.read_u2le()
self.date = self._io.read_u2le()
self.start_clus = self._io.read_u2le()
self.file_size = self._io.read_u4le()
class RootDirectory(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.records = [None] * (self._root.boot_sector.bpb.max_root_dir_rec)
for i in range(self._root.boot_sector.bpb.max_root_dir_rec):
self.records[i] = Vfat.RootDirectoryRec(self._io, self, self._root)
class ExtBiosParamBlockFat16(KaitaiStruct):
"""Extended BIOS Parameter Block (DOS 4.0+, OS/2 1.0+). Used only
for FAT12 and FAT16.
"""
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.phys_drive_num = self._io.read_u1()
self.reserved1 = self._io.read_u1()
self.ext_boot_sign = self._io.read_u1()
self.volume_id = self._io.read_bytes(4)
self.partition_volume_label = (KaitaiStream.bytes_strip_right(self._io.read_bytes(11), 32)).decode(u"ASCII")
self.fs_type_str = (KaitaiStream.bytes_strip_right(self._io.read_bytes(8), 32)).decode(u"ASCII")
@property
def fats(self):
if hasattr(self, '_m_fats'):
return self._m_fats if hasattr(self, '_m_fats') else None
_pos = self._io.pos()
self._io.seek(self.boot_sector.pos_fats)
self._m_fats = [None] * (self.boot_sector.bpb.num_fats)
for i in range(self.boot_sector.bpb.num_fats):
self._m_fats[i] = self._io.read_bytes(self.boot_sector.size_fat)
self._io.seek(_pos)
return self._m_fats if hasattr(self, '_m_fats') else None
@property
def root_dir(self):
if hasattr(self, '_m_root_dir'):
return self._m_root_dir if hasattr(self, '_m_root_dir') else None
_pos = self._io.pos()
self._io.seek(self.boot_sector.pos_root_dir)
self._raw__m_root_dir = self._io.read_bytes(self.boot_sector.size_root_dir)
_io__raw__m_root_dir = KaitaiStream(BytesIO(self._raw__m_root_dir))
self._m_root_dir = Vfat.RootDirectory(_io__raw__m_root_dir, self, self._root)
self._io.seek(_pos)
return self._m_root_dir if hasattr(self, '_m_root_dir') else None