Bitmap font format for the GRUB 2 bootloader.
This page hosts a formal specification of GRUB 2 font 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 = Grub2Font.from_file("path/to/local/file.pf2")
Or parse structure from a string of bytes:
bytes = "\x00\x01\x02..."
data = Grub2Font.new(Kaitai::Struct::Stream.new(bytes))
After that, one can get various attributes from the structure by invoking getter methods like:
data.sections # => The "DATA" section acts as a terminator. The documentation says:
"A marker that indicates the remainder of the file is data accessed
via the character index (CHIX) section. When reading this font file,
the rest of the file can be ignored when scanning the sections."
# 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
##
# Bitmap font format for the GRUB 2 bootloader.
# @see https://grub.gibibit.com/New_font_format Source
class Grub2Font < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@magic = @_io.read_bytes(12)
raise Kaitai::Struct::ValidationNotEqualError.new([70, 73, 76, 69, 0, 0, 0, 4, 80, 70, 70, 50].pack('C*'), magic, _io, "/seq/0") if not magic == [70, 73, 76, 69, 0, 0, 0, 4, 80, 70, 70, 50].pack('C*')
@sections = []
i = 0
begin
_ = Section.new(@_io, self, @_root)
@sections << _
i += 1
end until _.section_type == "DATA"
self
end
class PtszSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@font_point_size = @_io.read_u2be
self
end
attr_reader :font_point_size
end
class FamiSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@font_family_name = (@_io.read_bytes_term(0, false, true, true)).force_encoding("ASCII")
self
end
attr_reader :font_family_name
end
class WeigSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@font_weight = (@_io.read_bytes_term(0, false, true, true)).force_encoding("ASCII")
self
end
attr_reader :font_weight
end
class MaxwSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@maximum_character_width = @_io.read_u2be
self
end
attr_reader :maximum_character_width
end
class DescSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@descent_in_pixels = @_io.read_u2be
self
end
attr_reader :descent_in_pixels
end
class Section < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@section_type = (@_io.read_bytes(4)).force_encoding("ASCII")
@len_body = @_io.read_u4be
if section_type != "DATA"
case section_type
when "MAXH"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = MaxhSection.new(_io__raw_body, self, @_root)
when "FAMI"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = FamiSection.new(_io__raw_body, self, @_root)
when "PTSZ"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = PtszSection.new(_io__raw_body, self, @_root)
when "MAXW"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = MaxwSection.new(_io__raw_body, self, @_root)
when "SLAN"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = SlanSection.new(_io__raw_body, self, @_root)
when "WEIG"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = WeigSection.new(_io__raw_body, self, @_root)
when "CHIX"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = ChixSection.new(_io__raw_body, self, @_root)
when "DESC"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = DescSection.new(_io__raw_body, self, @_root)
when "NAME"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = NameSection.new(_io__raw_body, self, @_root)
when "ASCE"
@_raw_body = @_io.read_bytes(len_body)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = AsceSection.new(_io__raw_body, self, @_root)
else
@body = @_io.read_bytes(len_body)
end
end
self
end
attr_reader :section_type
##
# Should be set to `0xFFFF_FFFF` for `section_type != "DATA"`
attr_reader :len_body
attr_reader :body
attr_reader :_raw_body
end
class AsceSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@ascent_in_pixels = @_io.read_u2be
self
end
attr_reader :ascent_in_pixels
end
class ChixSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@characters = []
i = 0
while not @_io.eof?
@characters << Character.new(@_io, self, @_root)
i += 1
end
self
end
class Character < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@code_point = @_io.read_u4be
@flags = @_io.read_u1
@ofs_definition = @_io.read_u4be
self
end
def definition
return @definition unless @definition.nil?
io = _root._io
_pos = io.pos
io.seek(ofs_definition)
@definition = CharacterDefinition.new(io, self, @_root)
io.seek(_pos)
@definition
end
##
# Unicode code point
attr_reader :code_point
attr_reader :flags
attr_reader :ofs_definition
end
class CharacterDefinition < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@width = @_io.read_u2be
@height = @_io.read_u2be
@x_offset = @_io.read_s2be
@y_offset = @_io.read_s2be
@device_width = @_io.read_s2be
@bitmap_data = @_io.read_bytes((((width * height) + 7) / 8))
self
end
attr_reader :width
attr_reader :height
attr_reader :x_offset
attr_reader :y_offset
attr_reader :device_width
##
# A two-dimensional bitmap, one bit per pixel. It is organized as
# row-major, top-down, left-to-right. The most significant bit of
# each byte corresponds to the leftmost or uppermost pixel from all
# bits of the byte. If a bit is set (1, `true`), the pixel is set to
# the font color, if a bit is clear (0, `false`), the pixel is
# transparent.
#
# Rows are **not** padded to byte boundaries (i.e., a
# single byte may contain bits belonging to multiple rows). The last
# byte of the bitmap _is_ padded with zero bits at all unused least
# significant bit positions so that the bitmap ends on a byte
# boundary.
attr_reader :bitmap_data
end
attr_reader :characters
end
class MaxhSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@maximum_character_height = @_io.read_u2be
self
end
attr_reader :maximum_character_height
end
class NameSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@font_name = (@_io.read_bytes_term(0, false, true, true)).force_encoding("ASCII")
self
end
attr_reader :font_name
end
class SlanSection < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@font_slant = (@_io.read_bytes_term(0, false, true, true)).force_encoding("ASCII")
self
end
attr_reader :font_slant
end
attr_reader :magic
##
# The "DATA" section acts as a terminator. The documentation says:
# "A marker that indicates the remainder of the file is data accessed
# via the character index (CHIX) section. When reading this font file,
# the rest of the file can be ignored when scanning the sections."
attr_reader :sections
end