decoders/ds243x/pd.py

   1 ##
   2 ## This file is part of the libsigrokdecode project.
   3 ##
   4 ## Copyright (C) 2017 Kevin Redon <kingkevin@cuvoodoo.info>
   5 ## Copyright (C) 2017 Soeren Apel <soeren@apelpie.net>
   6 ##
   7 ## This program is free software; you can redistribute it and/or modify
   8 ## it under the terms of the GNU General Public License as published by
   9 ## the Free Software Foundation; either version 2 of the License, or
  10 ## (at your option) any later version.
  11 ##
  12 ## This program is distributed in the hope that it will be useful,
  13 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ## GNU General Public License for more details.
  16 ##
  17 ## You should have received a copy of the GNU General Public License
  18 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
  19 ##
  20
  21 import sigrokdecode as srd
  22
  23 # Dictionary of FUNCTION commands and their names.
  24 commands_2432 = {
  25     0x0f: 'Write scratchpad',
  26     0xaa: 'Read scratchpad',
  27     0x55: 'Copy scratchpad',
  28     0xf0: 'Read memory',
  29     0x5a: 'Load first secret',
  30     0x33: 'Compute next secret',
  31     0xa5: 'Read authenticated page',
  32 }
  33
  34 commands_2433 = {
  35     0x0f: 'Write scratchpad',
  36     0xaa: 'Read scratchpad',
  37     0x55: 'Copy scratchpad',
  38     0xf0: 'Read memory',
  39 }
  40
  41 # Maxim DS243x family code, present at the end of the ROM code.
  42 family_codes = {
  43     0x33: ('DS2432', commands_2432),
  44     0x23: ('DS2433', commands_2433),
  45 }
  46
  47 # Calculate the CRC-16 checksum.
  48 # Initial value: 0x0000, xor-in: 0x0000, polynom 0x8005, xor-out: 0xffff.
  49 def crc16(byte_array):
  50     reverse = 0xa001 # Use the reverse polynom to make algo simpler.
  51     crc = 0x0000 # Initial value.
  52     # Reverse CRC calculation.
  53     for byte in byte_array:
  54         for bit in range(8):
  55             if (byte ^ crc) & 1:
  56                 crc = (crc >> 1) ^ reverse
  57             else:
  58                 crc >>= 1
  59             byte >>= 1
  60     crc ^= 0xffff # Invert CRC.
  61     return crc
  62
  63 class Decoder(srd.Decoder):
  64     api_version = 3
  65     id = 'ds243x'
  66     name = 'DS243x'
  67     longname = 'Maxim DS2432/2433'
  68     desc = 'Maxim DS243x series 1-Wire EEPROM protocol.'
  69     license = 'gplv2+'
  70     inputs = ['onewire_network']
  71     outputs = ['ds243x']
  72     tags = ['IC', 'Memory']
  73     annotations = (
  74         ('text', 'Human-readable text'),
  75     )
  76     binary = (
  77         ('mem_read', 'Data read from memory'),
  78     )
  79
  80     def __init__(self):
  81         self.reset()
  82
  83     def reset(self):
  84         # Bytes for function command.
  85         self.bytes = []
  86         self.family_code = None
  87         self.family = ''
  88         self.commands = commands_2432 # Use max command set until we know better.
  89
  90     def start(self):
  91         self.out_ann = self.register(srd.OUTPUT_ANN)
  92         self.out_binary = self.register(srd.OUTPUT_BINARY)
  93
  94     def putx(self, data):
  95         self.put(self.ss, self.es, self.out_ann, data)
  96
  97     def decode(self, ss, es, data):
  98         code, val = data
  99
 100         if code == 'RESET/PRESENCE':
 101             self.ss, self.es = ss, es
 102             self.putx([0, ['Reset/presence: %s'
 103                            % ('true' if val else 'false')]])
 104             self.bytes = []
 105         elif code == 'ROM':
 106             self.ss, self.es = ss, es
 107             self.family_code = val & 0xff
 108
 109             s = None
 110             if self.family_code in family_codes:
 111                 self.family, self.commands = family_codes[val & 0xff]
 112                 s = 'is 0x%02x, %s detected' % (self.family_code, self.family)
 113             else:
 114                 s = '0x%02x unknown' % (self.family_code)
 115
 116             self.putx([0, ['ROM: 0x%016x (%s)' % (val, 'family code ' + s),
 117                            'ROM: 0x%016x (%s)' % (val, self.family)]])
 118             self.bytes = []
 119         elif code == 'DATA':
 120             self.bytes.append(val)
 121             if 1 == len(self.bytes):
 122                 self.ss, self.es = ss, es
 123                 if val not in self.commands:
 124                     self.putx([0, ['Unrecognized command: 0x%02x' % val]])
 125                 else:
 126                     self.putx([0, ['Function command: %s (0x%02x)'
 127                                    % (self.commands[val], val)]])
 128             elif 0x0f == self.bytes[0]: # Write scratchpad
 129                 if 2 == len(self.bytes):
 130                     self.ss = ss
 131                 elif 3 == len(self.bytes):
 132                     self.es = es
 133                     self.putx([0, ['Target address: 0x%04x'
 134                                    % ((self.bytes[2] << 8) + self.bytes[1])]])
 135                 elif 4 == len(self.bytes):
 136                     self.ss = ss
 137                 elif 11 == len(self.bytes):
 138                     self.es = es
 139                     self.putx([0, ['Data: ' + (','.join(format(n, '#04x')
 140                                        for n in self.bytes[3:11]))]])
 141                 elif 12 == len(self.bytes):
 142                     self.ss = ss
 143                 elif 13 == len(self.bytes):
 144                     self.es = es
 145                     self.putx([0, ['CRC: '
 146                         + ('ok' if crc16(self.bytes[0:11]) == (self.bytes[11]
 147                         + (self.bytes[12] << 8)) else 'error')]])
 148             elif 0xaa == self.bytes[0]: # Read scratchpad
 149                 if 2 == len(self.bytes):
 150                     self.ss = ss
 151                 elif 3 == len(self.bytes):
 152                     self.es = es
 153                     self.putx([0, ['Target address: 0x%04x'
 154                                    % ((self.bytes[2] << 8) + self.bytes[1])]])
 155                 elif 4 == len(self.bytes):
 156                     self.ss, self.es = ss, es
 157                     self.putx([0, ['Data status (E/S): 0x%02x'
 158                                    % (self.bytes[3])]])
 159                 elif 5 == len(self.bytes):
 160                     self.ss = ss
 161                 elif 12 == len(self.bytes):
 162                     self.es = es
 163                     self.putx([0, ['Data: ' + (','.join(format(n, '#04x')
 164                                        for n in self.bytes[4:12]))]])
 165                 elif 13 == len(self.bytes):
 166                     self.ss = ss
 167                 elif 14 == len(self.bytes):
 168                     self.es = es
 169                     self.putx([0, ['CRC: '
 170                         + ('ok' if crc16(self.bytes[0:12]) == (self.bytes[12]
 171                         + (self.bytes[13] << 8)) else 'error')]])
 172             elif 0x5a == self.bytes[0]: # Load first secret
 173                 if 2 == len(self.bytes):
 174                     self.ss = ss
 175                 elif 4 == len(self.bytes):
 176                     self.es = es
 177                     self.putx([0, ['Authorization pattern (TA1, TA2, E/S): '
 178                         + (','.join(format(n, '#04x')
 179                             for n in self.bytes[1:4]))]])
 180                 elif 4 < len(self.bytes):
 181                     self.ss, self.es = ss, es
 182                     if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
 183                         self.putx([0, ['End of operation']])
 184             elif 0x33 == self.bytes[0]: # Compute next secret
 185                 if 2 == len(self.bytes):
 186                     self.ss = ss
 187                 elif 3 == len(self.bytes):
 188                     self.es = es
 189                     self.putx([0, ['Target address: 0x%04x'
 190                                    % ((self.bytes[2] << 8) + self.bytes[1])]])
 191                 elif 3 < len(self.bytes):
 192                     self.ss, self.es = ss, es
 193                     if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
 194                         self.putx([0, ['End of operation']])
 195             elif 0x55 == self.bytes[0]: # Copy scratchpad
 196                 if 2 == len(self.bytes):
 197                     self.ss = ss
 198                 elif 4 == len(self.bytes):
 199                     self.es = es
 200                     self.putx([0, ['Authorization pattern (TA1, TA2, E/S): '
 201                         + (','.join(format(n, '#04x')
 202                             for n in self.bytes[1:4]))]])
 203                 elif 5 == len(self.bytes):
 204                     self.ss = ss
 205                 elif 24 == len(self.bytes):
 206                     self.es = es
 207                     mac = ','.join(format(n, '#04x') for n in self.bytes[4:24])
 208                     self.putx([0, ['Message authentication code: ' + mac,
 209                                    'MAC: ' + mac]])
 210                 elif 24 < len(self.bytes):
 211                     self.ss, self.es = ss, es
 212                     if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
 213                         self.putx([0, ['Operation succeeded']])
 214                     elif (0 == self.bytes[-1]):
 215                         self.putx([0, ['Operation failed']])
 216             elif 0xa5 == self.bytes[0]: # Read authenticated page
 217                 if 2 == len(self.bytes):
 218                     self.ss = ss
 219                 elif 3 == len(self.bytes):
 220                     self.es = es
 221                     self.putx([0, ['Target address: 0x%04x'
 222                                    % ((self.bytes[2] << 8) + self.bytes[1])]])
 223                 elif 4 == len(self.bytes):
 224                     self.ss = ss
 225                 elif 35 == len(self.bytes):
 226                     self.es = es
 227                     self.putx([0, ['Data: ' + (','.join(format(n, '#04x')
 228                                        for n in self.bytes[3:35]))]])
 229                 elif 36 == len(self.bytes):
 230                     self.ss, self.es = ss, es
 231                     self.putx([0, ['Padding: '
 232                         + ('ok' if 0xff == self.bytes[-1] else 'error')]])
 233                 elif 37 == len(self.bytes):
 234                     self.ss = ss
 235                 elif 38 == len(self.bytes):
 236                     self.es = es
 237                     self.putx([0, ['CRC: '
 238                         + ('ok' if crc16(self.bytes[0:36]) == (self.bytes[36]
 239                         + (self.bytes[37] << 8)) else 'error')]])
 240                 elif 39 == len(self.bytes):
 241                     self.ss = ss
 242                 elif 58 == len(self.bytes):
 243                     self.es = es
 244                     mac = ','.join(format(n, '#04x') for n in self.bytes[38:58])
 245                     self.putx([0, ['Message authentication code: ' + mac,
 246                                    'MAC: ' + mac]])
 247                 elif 59 == len(self.bytes):
 248                     self.ss = ss
 249                 elif 60 == len(self.bytes):
 250                     self.es = es
 251                     self.putx([0, ['MAC CRC: '
 252                         + ('ok' if crc16(self.bytes[38:58]) == (self.bytes[58]
 253                         + (self.bytes[59] << 8)) else 'error')]])
 254                 elif 60 < len(self.bytes):
 255                     self.ss, self.es = ss, es
 256                     if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
 257                         self.putx([0, ['Operation completed']])
 258             elif 0xf0 == self.bytes[0]: # Read memory
 259                 if 2 == len(self.bytes):
 260                     self.ss = ss
 261                 elif 3 == len(self.bytes):
 262                     self.es = es
 263                     self.putx([0, ['Target address: 0x%04x'
 264                                    % ((self.bytes[2] << 8) + self.bytes[1])]])
 265                 elif 3 < len(self.bytes):
 266                     self.ss, self.es = ss, es
 267                     self.putx([0, ['Data: 0x%02x' % (self.bytes[-1])]])
 268
 269                     bdata = self.bytes[-1].to_bytes(1, byteorder='big')
 270                     self.put(ss, es, self.out_binary, [0, bdata])