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mirror of https://github.com/ARM-software/devlib.git synced 2025-02-25 14:07:50 +00:00

trace/serial_trace: Add capability to trace serial traffic

We add a TraceCollector which logs the traffic on a serial port. This
can then be used to debug why a board crashes, or to extract extra
information from the device whilst it is running a workload.
This commit is contained in:
Sascha Bischoff 2018-06-12 16:24:39 +01:00 committed by setrofim
parent c4f6a1a85f
commit 6abe6067da
3 changed files with 78 additions and 2 deletions

@ -25,6 +25,7 @@ from devlib.derived.energy import DerivedEnergyMeasurements
from devlib.derived.fps import DerivedGfxInfoStats, DerivedSurfaceFlingerStats
from devlib.trace.ftrace import FtraceCollector
from devlib.trace.serial_trace import SerialTraceCollector
from devlib.host import LocalConnection
from devlib.utils.android import AdbConnection

@ -0,0 +1,75 @@
from pexpect.exceptions import TIMEOUT
import shutil
from tempfile import NamedTemporaryFile
from devlib.trace import TraceCollector
from devlib.utils.serial_port import get_connection
class SerialTraceCollector(TraceCollector):
@property
def collecting(self):
return self._collecting
def __init__(self, target, serial_port, baudrate, timeout=20):
super(SerialTraceCollector, self).__init__(target)
self.serial_port = serial_port
self.baudrate = baudrate
self.timeout = timeout
self._serial_target = None
self._conn = None
self._tmpfile = None
self._collecting = False
def reset(self):
if self._collecting:
raise RuntimeError("reset was called whilst collecting")
if self._tmpfile:
self._tmpfile.close()
self._tmpfile = None
def start(self):
if self._collecting:
raise RuntimeError("start was called whilst collecting")
self._tmpfile = NamedTemporaryFile()
self._tmpfile.write("-------- Starting serial logging --------\n")
self._serial_target, self._conn = get_connection(port=self.serial_port,
baudrate=self.baudrate,
timeout=self.timeout,
logfile=self._tmpfile,
init_dtr=0)
self._collecting = True
def stop(self):
if not self._collecting:
raise RuntimeError("stop was called whilst not collecting")
# We expect the below to fail, but we need to get pexpect to
# do something so that it interacts with the serial device,
# and hence updates the logfile.
try:
self._serial_target.expect(".", timeout=1)
except TIMEOUT:
pass
self._serial_target.close()
del self._conn
self._tmpfile.write("-------- Stopping serial logging --------\n")
self._collecting = False
def get_trace(self, outfile):
if self._collecting:
raise RuntimeError("get_trace was called whilst collecting")
shutil.copy(self._tmpfile.name, outfile)
self._tmpfile.close()
self._tmpfile = None

@ -49,7 +49,7 @@ def pulse_dtr(conn, state=True, duration=0.1):
def get_connection(timeout, init_dtr=None, logcls=SerialLogger,
*args, **kwargs):
logfile=None, *args, **kwargs):
if init_dtr is not None:
kwargs['dsrdtr'] = True
try:
@ -60,7 +60,7 @@ def get_connection(timeout, init_dtr=None, logcls=SerialLogger,
conn.setDTR(init_dtr)
conn.nonblocking()
conn.flushOutput()
target = fdpexpect.fdspawn(conn.fileno(), timeout=timeout)
target = fdpexpect.fdspawn(conn.fileno(), timeout=timeout, logfile=logfile)
target.logfile_read = logcls('read')
target.logfile_send = logcls('send')