This page hosts a formal specification of GPT (GUID) 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 Ruby generated by Kaitai Struct depends on the Ruby runtime library. You have to install it before you can parse data.
The Ruby runtime library can be installed from RubyGems:
gem install kaitai-structParse a local file and get structure in memory:
data = GptPartitionTable.from_file("path/to/local/file.bin")
Or parse structure from a string of bytes:
bytes = "\x00\x01\x02..."
data = GptPartitionTable.new(Kaitai::Struct::Stream.new(bytes))
After that, one can get various attributes from the structure by invoking getter methods like:
data.sector_size # => get sector size
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
require 'kaitai/struct/struct'
unless Gem::Version.new(Kaitai::Struct::VERSION) >= Gem::Version.new('0.9')
raise "Incompatible Kaitai Struct Ruby API: 0.9 or later is required, but you have #{Kaitai::Struct::VERSION}"
end
##
# @see https://en.wikipedia.org/wiki/GUID_Partition_Table Source
class GptPartitionTable < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
self
end
class PartitionEntry < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@type_guid = @_io.read_bytes(16)
@guid = @_io.read_bytes(16)
@first_lba = @_io.read_u8le
@last_lba = @_io.read_u8le
@attributes = @_io.read_u8le
@name = (@_io.read_bytes(72)).force_encoding("UTF-16LE")
self
end
attr_reader :type_guid
attr_reader :guid
attr_reader :first_lba
attr_reader :last_lba
attr_reader :attributes
attr_reader :name
end
class PartitionHeader < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@signature = @_io.read_bytes(8)
raise Kaitai::Struct::ValidationNotEqualError.new([69, 70, 73, 32, 80, 65, 82, 84].pack('C*'), signature, _io, "/types/partition_header/seq/0") if not signature == [69, 70, 73, 32, 80, 65, 82, 84].pack('C*')
@revision = @_io.read_u4le
@header_size = @_io.read_u4le
@crc32_header = @_io.read_u4le
@reserved = @_io.read_u4le
@current_lba = @_io.read_u8le
@backup_lba = @_io.read_u8le
@first_usable_lba = @_io.read_u8le
@last_usable_lba = @_io.read_u8le
@disk_guid = @_io.read_bytes(16)
@entries_start = @_io.read_u8le
@entries_count = @_io.read_u4le
@entries_size = @_io.read_u4le
@crc32_array = @_io.read_u4le
self
end
def entries
return @entries unless @entries.nil?
io = _root._io
_pos = io.pos
io.seek((entries_start * _root.sector_size))
@_raw_entries = []
@entries = []
(entries_count).times { |i|
@_raw_entries << io.read_bytes(entries_size)
_io__raw_entries = Kaitai::Struct::Stream.new(@_raw_entries[i])
@entries << PartitionEntry.new(_io__raw_entries, self, @_root)
}
io.seek(_pos)
@entries
end
attr_reader :signature
attr_reader :revision
attr_reader :header_size
attr_reader :crc32_header
attr_reader :reserved
attr_reader :current_lba
attr_reader :backup_lba
attr_reader :first_usable_lba
attr_reader :last_usable_lba
attr_reader :disk_guid
attr_reader :entries_start
attr_reader :entries_count
attr_reader :entries_size
attr_reader :crc32_array
attr_reader :_raw_entries
end
def sector_size
return @sector_size unless @sector_size.nil?
@sector_size = 512
@sector_size
end
def primary
return @primary unless @primary.nil?
io = _root._io
_pos = io.pos
io.seek(_root.sector_size)
@primary = PartitionHeader.new(io, self, @_root)
io.seek(_pos)
@primary
end
def backup
return @backup unless @backup.nil?
io = _root._io
_pos = io.pos
io.seek((_io.size - _root.sector_size))
@backup = PartitionHeader.new(io, self, @_root)
io.seek(_pos)
@backup
end
end