src/utils/intelhex.rb

   1 ##
   2 ## This file is part of INAV.
   3 ##
   4 ## INAV is free software. You can redistribute this software
   5 ## and/or modify this software under the terms of the
   6 ## GNU General Public License as published by the Free Software
   7 ## Foundation, either version 3 of the License, or (at your option)
   8 ## any later version.
   9 ##
  10 ## INAV is distributed in the hope that they will be
  11 ## useful, but WITHOUT ANY WARRANTY; without even the implied
  12 ## warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13 ## See the GNU General Public License for more details.
  14 ##
  15 ## You should have received a copy of the GNU General Public License
  16 ## along with this software.
  17 ##
  18 ## If not, see <http://www.gnu.org/licenses/>.
  19 ##
  20
  21 class IntelHex
  22
  23     class Section < Struct.new(:address, :io); end
  24
  25     def initialize address = 0, bin_io = nil, start_address = nil
  26         @sections = Array.new
  27         @start_address = start_address == true ? address : start_address
  28         add_section address, bin_io if bin_io
  29     end
  30
  31     def add_section address, io
  32         sections << Section.new(address, io)
  33     end
  34
  35     def write io
  36         sections.each { |section| write_section section, io }
  37         write_start_linear_address start_address, io if start_address
  38         write_end_of_file io
  39         nil
  40     end
  41
  42     attr_reader :sections
  43     attr_accessor :start_address
  44
  45     private
  46
  47     def calc_crc address, record_type, data
  48         sum = 0
  49         sum += (address & 0xFF00) >> 8
  50         sum += (address & 0x00FF)
  51         sum += record_type
  52
  53         if data.is_a? Integer
  54             sum += data > 0xFFFF ? 4 : 2
  55             sum += (data & 0xFF000000) >> 24
  56             sum += (data & 0x00FF0000) >> 16
  57             sum += (data & 0x0000FF00) >> 8
  58             sum += (data & 0x000000FF)
  59         else
  60             sum += data.bytesize
  61             sum += data.each_byte.sum
  62         end
  63
  64         ((sum ^ 0xFF) + 1) & 0xFF
  65     end
  66
  67     def write_end_of_file io
  68         io.puts ":00000001FF"
  69     end
  70
  71     def write_start_linear_address address, io
  72         crc = calc_crc 0, 5, address
  73         io.printf ":04000005%08X%02X\n", address, crc
  74     end
  75
  76     def write_extended_linear_address address, io
  77         address_msw = (address & 0xffff0000) >> 16
  78         crc = calc_crc 0, 4, address_msw
  79         io.printf ":02000004%04X%02X\n", address_msw, crc
  80     end
  81
  82     def write_data address, data, io
  83         address &= 0xFFFF
  84         hex_data = data.each_byte.map { |byte| "%02X" % byte }.join
  85         crc = calc_crc address, 0, data
  86         io.printf ":%02X%04X00%s%02X\n", data.bytesize, address, hex_data, crc
  87     end
  88
  89     def write_section section, io
  90         previous_address = 0
  91         address = section.address
  92         while data = section.io.read(16)
  93             write_extended_linear_address address, io if (previous_address & 0xFFFF0000) != (address & 0xFFFF0000)
  94             previous_address = address
  95             write_data address, data, io
  96             address += data.bytesize
  97         end
  98     end
  99
 100 end