DebugMux client for [Sony] Ericsson phones and modems
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sedbgmux/transport.py

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4.2 KiB

#!/usr/bin/env python3
# This file is a part of sedbgmux, an open source DebugMux client.
# Copyright (c) 2022 Vadim Yanitskiy <axilirator@gmail.com>
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# 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 3 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 logging as log
import serial
import abc
class TransportIOError(Exception):
''' I/O error during read/write operation '''
class Transport(abc.ABC):
''' Abstract transport layer for DebugMux '''
@abc.abstractmethod
def connect(self, opts: dict) -> None:
''' Establish connection to the target and enter DebugMux mode '''
@abc.abstractmethod
def disconnect(self) -> None:
''' Escape DebugMux mode and terminate connection with the target '''
@abc.abstractmethod
def write(self, data: bytes) -> int:
''' Write the given data bytes '''
@abc.abstractmethod
def read(self, length: int = 0) -> bytes:
''' Read the given number of bytes '''
class TransportModem(Transport):
''' Modem based transport layer for DebugMux '''
def __init__(self, opts: dict) -> None:
self.modem_port = opts.serial_port
self.modem_baudrate = opts.serial_baudrate
self.modem_timeout = opts.serial_timeout
def connect(self) -> None:
''' Establish connection to the target and enter DebugMux mode '''
self._sl = serial.Serial(port=self.modem_port,
baudrate=self.modem_baudrate,
bytesize=8, parity='N', stopbits=1,
timeout=self.modem_timeout,
# xonoff=False,
rtscts=False,
dsrdtr=False)
# Test the modem
self.transceive('AT', 'OK')
# Enable DebugMux mode
self.transceive('AT*EDEBUGMUX', 'CONNECT')
def disconnect(self) -> None:
''' Escape DebugMux mode and terminate connection with the target '''
# TODO: escape DebugMux mode
self._sl.close()
del self._sl
def write(self, data: bytes) -> int:
''' Write the given data bytes '''
try:
return self._sl.write(data)
except Exception as e:
raise TransportIOError('Failed to write() data') from e
def read(self, length: int = 0) -> bytes:
''' Read the given number of bytes '''
try:
return self._sl.read(length)
except Exception as e:
raise TransportIOError('Failed to read() data') from e
def send_at_cmd(self, cmd: str, handle_echo: bool = True) -> None:
''' Send an AT command to the modem '''
data: bytes = cmd.encode() + b'\r'
log.debug('MODEM <- %s', str(data))
self.write(data)
while handle_echo:
rdata: bytes = self._sl.readline()
line: str = rdata.rstrip().decode()
if not line:
continue # Ignore empty lines
if line == cmd:
break
log.debug('MODEM -> %s', str(rdata))
def read_at_rsp(self) -> str:
''' Read an AT command response from the modem '''
while True:
rdata: bytes = self._sl.readline()
line: str = rdata.rstrip().decode()
if not line:
continue # Ignore empty lines
log.debug('MODEM -> %s', str(rdata))
if line.startswith(('+', '*')):
continue # Ignore events reported by the modem
return line
def transceive(self, cmd: str, exp: str) -> None:
self.send_at_cmd(cmd)
rsp = self.read_at_rsp()
assert rsp == exp