Celestial/rom.rb
2018-05-19 21:29:39 -07:00

151 lines
2.2 KiB
Ruby

# General purpose binary reader
# 8 16 32 64
# C S L Q - unsigned
# c s l q - unsigned
# < LE
# > BE
# A - binary string
# z - null terminated
# H - hex string
class ROM
def initialize str
@rom = str
@cur = 0
@base = 0
end
def self.from_file fn
data = File.open(fn, "rb") { |io| io.read }
ROM.new data
end
def set_base pos
@base = pos
end
def seek pos
@cur = pos + @base
end
def seek_rel pos
@cur += pos
end
def tell
@cur - @base
end
def read_str len
r = @rom[@cur..(@cur + len - 1)].unpack("A#{len}").first
@cur += len
r
end
def read_str_varlen
len = read_varlen_le
r = @rom[@cur..(@cur + len - 1)].unpack("A#{len}").first
@cur += len
r
end
def read_byte
r = @rom[@cur].ord
@cur += 1
r
end
def read_bool
read_byte == 1
end
def read_s8
r = @rom[@cur].unpack("c").first
@cur += 1
r
end
def read_u16_le
r = @rom[@cur..(@cur + 3)].unpack('S<').first
@cur += 2
r
end
def read_s16_le
r = @rom[@cur..(@cur + 3)].unpack('s<').first
@cur += 2
r
end
def read_u16_be
r = @rom[@cur..(@cur + 3)].unpack('S>').first
@cur += 2
r
end
def read_u32_le
r = @rom[@cur..(@cur + 3)].unpack('L<').first
@cur += 4
r
end
def read_s32_le
r = @rom[@cur..(@cur + 3)].unpack('l<').first
@cur += 4
r
end
def read_u32_be
r = @rom[@cur..(@cur + 3)].unpack('L>').first
@cur += 4
r
end
def read_f32_le
r = @rom[@cur..(@cur + 3)].unpack('e').first
@cur += 4
r
end
def read_bin len
r = @rom[@cur..(@cur + len - 1)]
@cur += len
r
end
def read_binswap len
togo = len
bin_data = "".b
while togo > 0
r = @rom[@cur..(@cur + 3)].unpack('L>')
bin_data += r.pack('L<')
@cur += 4
togo -= 4
end
bin_data
end
def read_varlen_le
val = 0
r = read_byte
val = r & 0x7F
return val if r < 0x80
r = read_byte << 7
val + r
end
def read_varlen_be
val = 0
r = read_byte
val = r & 0x7F
return val if r < 0x80
r = read_byte
val = (val << 8) + r
val
end
def msg str
puts "%08X(%08X): %s" % [@cur, tell, str]
end
end