Format for Android DTB/DTBO partitions. It's kind of archive with dtb/dtbo files. Used only when there is a separate unique partition (dtb, dtbo) on an android device to organize device tree files. The format consists of a header with info about size and number of device tree entries and the entries themselves. This format description could be used to extract device tree entries from a partition images and decompile them with dtc (device tree compiler).
This page hosts a formal specification of Android DTB/DTBO Partition 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 = AndroidDto.from_file("path/to/local/file.img")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = AndroidDto(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.header # => get header
# 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 AndroidDto(KaitaiStruct):
"""Format for Android DTB/DTBO partitions. It's kind of archive with
dtb/dtbo files. Used only when there is a separate unique partition
(dtb, dtbo) on an android device to organize device tree files.
The format consists of a header with info about size and number
of device tree entries and the entries themselves. This format
description could be used to extract device tree entries from a
partition images and decompile them with dtc (device tree compiler).
.. seealso::
Source - https://source.android.com/docs/core/architecture/dto/partitions
.. seealso::
Source - https://android.googlesource.com/platform/system/libufdt/+/refs/tags/android-10.0.0_r47
"""
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.header = AndroidDto.DtTableHeader(self._io, self, self._root)
self.entries = []
for i in range(self.header.dt_entry_count):
self.entries.append(AndroidDto.DtTableEntry(self._io, self, self._root))
class DtTableHeader(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(4)
if not self.magic == b"\xD7\xB7\xAB\x1E":
raise kaitaistruct.ValidationNotEqualError(b"\xD7\xB7\xAB\x1E", self.magic, self._io, u"/types/dt_table_header/seq/0")
self.total_size = self._io.read_u4be()
self.header_size = self._io.read_u4be()
self.dt_entry_size = self._io.read_u4be()
self.dt_entry_count = self._io.read_u4be()
self.dt_entries_offset = self._io.read_u4be()
self.page_size = self._io.read_u4be()
self.version = self._io.read_u4be()
class DtTableEntry(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.dt_size = self._io.read_u4be()
self.dt_offset = self._io.read_u4be()
self.id = self._io.read_u4be()
self.rev = self._io.read_u4be()
self.custom = []
for i in range(4):
self.custom.append(self._io.read_u4be())
@property
def body(self):
"""DTB/DTBO file."""
if hasattr(self, '_m_body'):
return self._m_body
io = self._root._io
_pos = io.pos()
io.seek(self.dt_offset)
self._m_body = io.read_bytes(self.dt_size)
io.seek(_pos)
return getattr(self, '_m_body', None)