--- /dev/null
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2017 Kevin Redon <kingkevin@cuvoodoo.info>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+##
+
+import sigrokdecode as srd
+
+# Dictionary of FUNCTION commands and their names.
+commands = {
+ 0x0f: 'Write scratchpad',
+ 0xaa: 'Read scratchpad',
+ 0x55: 'Copy scratchpad',
+ 0xf0: 'Read memory',
+ 0x5a: 'Load first secret',
+ 0x33: 'Compute next secret',
+ 0xa5: 'Read authenticated page',
+}
+
+# Maxim DS2432 family code, present at the end of the ROM code.
+family_code = 0x33
+
+# Calculate the CRC-16 checksum.
+# Initial value: 0x0000, xor-in: 0x0000, polynom 0x8005, xor-out: 0xffff.
+def crc16(byte_array):
+ reverse = 0xa001 # Use the reverse polynom to make algo simpler.
+ crc = 0x0000 # Initial value.
+ # Reverse CRC calculation.
+ for byte in byte_array:
+ for bit in range(8):
+ if (byte ^ crc) & 1:
+ crc = (crc >> 1) ^ reverse
+ else:
+ crc >>= 1
+ byte >>= 1
+ crc ^= 0xffff # Invert CRC.
+ return crc
+
+class Decoder(srd.Decoder):
+ api_version = 3
+ id = 'ds2432'
+ name = 'DS2432'
+ longname = 'Maxim DS2432 1-Wire 1k-Bit Protected EEPROM with SHA-1 Engine'
+ desc = '1-Wire 1k-Bit Protected EEPROM with SHA-1 Engine.'
+ license = 'gplv2+'
+ inputs = ['onewire_network']
+ outputs = ['ds2432']
+ annotations = (
+ ('text', 'Human-readable text'),
+ )
+
+ def __init__(self):
+ # Bytes for function command.
+ self.bytes = []
+
+ def start(self):
+ self.out_ann = self.register(srd.OUTPUT_ANN)
+
+ def putx(self, data):
+ self.put(self.ss, self.es, self.out_ann, data)
+
+ def decode(self, ss, es, data):
+ code, val = data
+
+ if code == 'RESET/PRESENCE':
+ self.ss, self.es = ss, es
+ self.putx([0, ['Reset/presence: %s'
+ % ('true' if val else 'false')]])
+ self.bytes = []
+ elif code == 'ROM':
+ self.ss, self.es = ss, es
+ self.putx([0, ['ROM: 0x%016x (family code %s to 0x%02x)'
+ % (val, 'matches' if family_code == (val & 0xff)
+ else 'does not match', family_code),
+ 'ROM: 0x%016x (family code %s)'
+ % (val, 'match' if family_code == (val & 0xff)
+ else 'mismatch')]])
+ self.bytes = []
+ elif code == 'DATA':
+ self.bytes.append(val)
+ if 1 == len(self.bytes):
+ self.ss, self.es = ss, es
+ if val not in commands:
+ self.putx([0, ['Unrecognized command: 0x%02x' % val]])
+ else:
+ self.putx([0, ['Function command: %s (0x%02x)'
+ % (commands[val], val)]])
+ elif 0x0f == self.bytes[0]: # Write scratchpad
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 3 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Target address: 0x%04x'
+ % ((self.bytes[2] << 8) + self.bytes[1])]])
+ elif 4 == len(self.bytes):
+ self.ss = ss
+ elif 11 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Data: ' + (','.join(format(n, '#04x')
+ for n in self.bytes[3:11]))]])
+ elif 12 == len(self.bytes):
+ self.ss = ss
+ elif 13 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['CRC: '
+ + ('ok' if crc16(self.bytes[0:11]) == (self.bytes[11]
+ + (self.bytes[12] << 8)) else 'error')]])
+ elif 0xaa == self.bytes[0]: # Read scratchpad
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 3 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Target address: 0x%04x'
+ % ((self.bytes[2] << 8) + self.bytes[1])]])
+ elif 4 == len(self.bytes):
+ self.ss, self.es = ss, es
+ self.putx([0, ['Data status (E/S): 0x%02x'
+ % (self.bytes[3])]])
+ elif 5 == len(self.bytes):
+ self.ss = ss
+ elif 12 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Data: ' + (','.join(format(n, '#04x')
+ for n in self.bytes[4:12]))]])
+ elif 13 == len(self.bytes):
+ self.ss = ss
+ elif 14 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['CRC: '
+ + ('ok' if crc16(self.bytes[0:12]) == (self.bytes[12]
+ + (self.bytes[13] << 8)) else 'error')]])
+ elif 0x5a == self.bytes[0]: # Load first secret
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 4 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Authorization pattern (TA1, TA2, E/S): '
+ + (','.join(format(n, '#04x')
+ for n in self.bytes[1:4]))]])
+ elif 4 < len(self.bytes):
+ self.ss, self.es = ss, es
+ if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
+ self.putx([0, ['End of operation']])
+ elif 0x33 == self.bytes[0]: # Compute next secret
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 3 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Target address: 0x%04x'
+ % ((self.bytes[2] << 8) + self.bytes[1])]])
+ elif 3 < len(self.bytes):
+ self.ss, self.es = ss, es
+ if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
+ self.putx([0, ['End of operation']])
+ elif 0x55 == self.bytes[0]: # Copy scratchpad
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 4 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Authorization pattern (TA1, TA2, E/S): '
+ + (','.join(format(n, '#04x')
+ for n in self.bytes[1:4]))]])
+ elif 5 == len(self.bytes):
+ self.ss = ss
+ elif 24 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Message authentication code: '
+ + (','.join(format(n, '#04x')
+ for n in self.bytes[4:24])),
+ 'MAC: '
+ + (','.join(format(n, '#04x')
+ for n in self.bytes[4:24])),
+ ]])
+ elif 24 < len(self.bytes):
+ self.ss, self.es = ss, es
+ if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
+ self.putx([0, ['Operation succeeded']])
+ elif (0 == self.bytes[-1]):
+ self.putx([0, ['Operation failed']])
+ elif 0xa5 == self.bytes[0]: # Read authenticated page
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 3 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Target address: 0x%04x'
+ % ((self.bytes[2] << 8) + self.bytes[1])]])
+ elif 4 == len(self.bytes):
+ self.ss = ss
+ elif 35 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Data: ' + (','.join(format(n, '#04x')
+ for n in self.bytes[3:35]))]])
+ elif 36 == len(self.bytes):
+ self.ss, self.es = ss, es
+ self.putx([0, ['Padding: '
+ + ('ok' if 0xff == self.bytes[-1] else 'error')]])
+ elif 37 == len(self.bytes):
+ self.ss = ss
+ elif 38 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['CRC: '
+ + ('ok' if crc16(self.bytes[0:36]) == (self.bytes[36]
+ + (self.bytes[37] << 8)) else 'error')]])
+ elif 39 == len(self.bytes):
+ self.ss = ss
+ elif 58 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Message authentication code: '
+ + (','.join(format(n, '#04x')
+ for n in self.bytes[38:58])),
+ 'MAC: '
+ + (','.join(format(n, '#04x')
+ for n in self.bytes[38:58])),
+ ]])
+ elif 59 == len(self.bytes):
+ self.ss = ss
+ elif 60 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['MAC CRC: '
+ + ('ok' if crc16(self.bytes[38:58]) == (self.bytes[58]
+ + (self.bytes[59] << 8)) else 'error')]])
+ elif 60 < len(self.bytes):
+ self.ss, self.es = ss, es
+ if (0xaa == self.bytes[-1] or 0x55 == self.bytes[-1]):
+ self.putx([0, ['Operation completed']])
+ elif 0xf0 == self.bytes[0]: # Read memory
+ if 2 == len(self.bytes):
+ self.ss = ss
+ elif 3 == len(self.bytes):
+ self.es = es
+ self.putx([0, ['Target address: 0x%04x'
+ % ((self.bytes[2] << 8) + self.bytes[1])]])
+ elif 3 < len(self.bytes):
+ self.ss, self.es = ss, es
+ self.putx([0, ['Data: 0x%02x' % (self.bytes[-1])]])
projects / libsigrokdecode.git / commitdiff