Merge pull request #50 from Sticklyman1936/master

Add Gem5Device to WA

wlauto/common/android/device.py

@@ -490,6 +490,11 @@ class AndroidDevice(BaseLinuxDevice):  # pylint: disable=W0223
     def get_properties(self, context):
         """Captures and saves the information from /system/build.prop and /proc/version"""
         props = super(AndroidDevice, self).get_properties(context)
+        props.update(self._get_android_properties(context))
+        return props
+
+    def _get_android_properties(self, context):
+        props = {}
         props['android_id'] = self.get_android_id()
         buildprop_file = os.path.join(context.host_working_directory, 'build.prop')
         if not os.path.isfile(buildprop_file):
@@ -498,9 +503,8 @@ class AndroidDevice(BaseLinuxDevice):  # pylint: disable=W0223
         context.add_run_artifact('build_properties', buildprop_file, 'export')
 
         dumpsys_window_file = os.path.join(context.host_working_directory, 'window.dumpsys')
-        dumpsys_window_output = self.execute('dumpsys window')
+        self.execute('{} > {}'.format('dumpsys window', 'window.dumpsys'))
-        with open(dumpsys_window_file, 'w') as wfh:
+        self.pull_file('window.dumpsys', dumpsys_window_file)
-            wfh.write(dumpsys_window_output)
         context.add_run_artifact('dumpsys_window', dumpsys_window_file, 'meta')
         return props
 

wlauto/devices/android/gem5/__init__.py

@@ -0,0 +1,744 @@
+#    Copyright 2014-2015 ARM Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Original implementation by Rene de Jong. Updated by Sascha Bischoff.
+
+import logging
+import os
+import re
+import shutil
+import socket
+import subprocess
+import sys
+import tarfile
+import time
+from pexpect import EOF, TIMEOUT
+
+from wlauto import AndroidDevice, settings, Parameter
+from wlauto.core import signal as sig
+from wlauto.utils import ssh, types
+from wlauto.exceptions import DeviceError, ConfigError
+
+
+class Gem5Device(AndroidDevice):
+    """
+    Implements gem5 Android device.
+
+    This class allows a user to connect WA to a simulation using gem5. The
+    connection to the device is made using the telnet connection of the
+    simulator, and is used for all commands. The simulator does not have ADB
+    support, and therefore we need to fall back to using standard shell
+    commands.
+
+    Files are copied into the simulation using a VirtIO 9P device in gem5. Files
+    are copied out of the simulated environment using the m5 writefile command
+    within the simulated system.
+
+    When starting the workload run, the simulator is automatically started by
+    Workload Automation, and a connection to the simulator is established. WA
+    will then wait for Android to boot on the simulated system (which can take
+    hours), prior to executing any other commands on the device. It is also
+    possible to resume from a checkpoint when starting the simulation. To do
+    this, please append the relevant checkpoint commands from the gem5
+    simulation script to the gem5_discription argument in the agenda.
+
+    Host system requirements:
+        * VirtIO support. We rely on diod on the host system. This can be
+          installed on ubuntu using the following command:
+
+                sudo apt-get install diod
+
+    Guest requirements:
+        * VirtIO support. We rely on VirtIO to move files into the simulation.
+          Please make sure that the following are set in the kernel
+          configuration:
+
+                CONFIG_NET_9P=y
+
+                CONFIG_NET_9P_VIRTIO=y
+
+                CONFIG_9P_FS=y
+
+                CONFIG_9P_FS_POSIX_ACL=y
+
+                CONFIG_9P_FS_SECURITY=y
+
+                CONFIG_VIRTIO_BLK=y
+
+        * m5 binary. Please make sure that the m5 binary is on the device and
+          can by found in the path.
+        * Busybox. Due to restrictions, we assume that busybox is installed in
+          the guest system, and can be found in the path.
+    """
+
+    name = 'gem5_android'
+    has_gpu = False
+    platform = 'android'
+    path_module = 'posixpath'
+
+    # gem5 can be very slow. Hence, we use some very long timeouts!
+    delay = 3600
+    long_delay = 3 * delay
+    ready_timeout = long_delay
+    default_timeout = delay
+
+    parameters = [
+        Parameter('core_names', default=[], override=True),
+        Parameter('core_clusters', default=[], override=True),
+        Parameter('gem5_binary', kind=str, default='./build/ARM/gem5.fast',
+                  mandatory=False, description="Command used to execute gem5. "
+                  "Adjust according to needs."),
+        Parameter('gem5_args', kind=types.arguments, mandatory=True,
+                  description="Command line passed to the gem5 simulation. This"
+                  " command line is used to set up the simulated system, and "
+                  "should be the same as used for a standard gem5 simulation "
+                  "without workload automation. Note that this is simulation "
+                  "script specific and will hence need to be tailored to each "
+                  "particular use case."),
+        Parameter('gem5_vio_args', kind=types.arguments, mandatory=True,
+                  constraint=lambda x: "{}" in str(x),
+                  description="gem5 VirtIO command line used to enable the "
+                  "VirtIO device in the simulated system. At the very least, "
+                  "the root parameter of the VirtIO9PDiod device must be "
+                  "exposed on the command line. Please set this root mount to "
+                  "{}, as it will be replaced with the directory used by "
+                  "Workload Automation at runtime."),
+        Parameter('temp_dir', kind=str, default='/tmp',
+                  description="Temporary directory used to pass files into the "
+                  "gem5 simulation. Workload Automation will automatically "
+                  "create a directory in this folder, and will remove it again "
+                  "once the simulation completes."),
+        Parameter('checkpoint', kind=bool, default=False,
+                  mandatory=False, description="This parameter "
+                  "tells Workload Automation to create a checkpoint of the "
+                  "simulated system once the guest system has finished booting."
+                  " This checkpoint can then be used at a later stage by other "
+                  "WA runs to avoid booting the guest system a second time. Set"
+                  " to True to take a checkpoint of the simulated system post "
+                  "boot."),
+        Parameter('run_delay', kind=int, default=0, mandatory=False,
+                  constraint=lambda x: x >= 0,
+                  description="This sets the time that the "
+                  "system should sleep in the simulated system prior to "
+                  "running and workloads or taking checkpoints. This allows "
+                  "the system to quieten down prior to running the workloads. "
+                  "When this is combined with the checkpoint_post_boot"
+                  " option, it allows the checkpoint to be created post-sleep,"
+                  " and therefore the set of workloads resuming from this "
+                  "checkpoint will not be required to sleep.")
+    ]
+
+    # Overwritten from Device. For documentation, see corresponding method in
+    # Device.
+
+    @property
+    def is_rooted(self):
+        # gem5 is always rooted
+        return True
+
+    def __init__(self, **kwargs):
+        self.logger = logging.getLogger('gem5Device')
+
+        super(Gem5Device, self).__init__(**kwargs)
+
+        # The gem5 subprocess
+        self.gem5 = None
+        self.gem5_port = -1
+        self.gem5outdir = os.path.join(settings.output_directory, "gem5")
+        self.stdout_file = None
+        self.stderr_file = None
+        self.stderr_filename = None
+        self.checkpoint = False
+        self.sckt = None
+
+        # Find the first one that does not exist. Ensures that we do not re-use
+        # the directory used by someone else.
+        for i in xrange(sys.maxint):
+            directory = os.path.join(self.temp_dir, "wa_{}".format(i))
+            try:
+                os.stat(directory)
+                continue
+            except OSError:
+                break
+        self.temp_dir = directory
+        self.logger.debug("Using {} as the temporary directory.".format(self.temp_dir))
+
+        # Start the gem5 simulation when WA starts a run using a signal.
+        sig.connect(self.init_gem5, sig.RUN_START)
+
+    def validate(self):
+        # Assemble the virtio args
+        self.gem5_vio_args = str(self.gem5_vio_args).format(self.temp_dir)
+        self.logger.debug("gem5 VirtIO command: {}".format(self.gem5_vio_args))
+
+    def init_gem5(self, _):
+        """
+        Start gem5, find out the telnet port and connect to the simulation.
+
+        We first create the temporary directory used by VirtIO to pass files
+        into the simulation, as well as the gem5 output directory.We then create
+        files for the standard output and error for the gem5 process. The gem5
+        process then is started.
+        """
+        self.logger.info("Creating temporary directory: {}".format(self.temp_dir))
+        os.mkdir(self.temp_dir)
+        os.mkdir(self.gem5outdir)
+
+        # We need to redirect the standard output and standard error for the
+        # gem5 process to a file so that we can debug when things go wrong.
+        f = os.path.join(self.gem5outdir, 'stdout')
+        self.stdout_file = open(f, 'w')
+        f = os.path.join(self.gem5outdir, 'stderr')
+        self.stderr_file = open(f, 'w')
+        # We need to keep this so we can check which port to use for the telnet
+        # connection.
+        self.stderr_filename = f
+
+        self.start_gem5()
+
+    def start_gem5(self):
+        """
+        Starts the gem5 simulator, and parses the output to get the telnet port.
+        """
+        self.logger.info("Starting the gem5 simulator")
+
+        command_line = "{} --outdir={}/gem5 {} {}".format(self.gem5_binary,
+                                                          settings.output_directory,
+                                                          self.gem5_args,
+                                                          self.gem5_vio_args)
+        self.logger.debug("gem5 command line: {}".format(command_line))
+        self.gem5 = subprocess.Popen(command_line.split(),
+                                     stdout=self.stdout_file,
+                                     stderr=self.stderr_file)
+
+        while self.gem5_port == -1:
+            # Check that gem5 is running!
+            if self.gem5.poll():
+                raise DeviceError("The gem5 process has crashed with error code {}!".format(self.gem5.poll()))
+
+            # Open the stderr file
+            f = open(self.stderr_filename, 'r')
+            for line in f:
+                m = re.search(r"Listening\ for\ system\ connection\ on\ port\ (?P<port>\d+)", line)
+                if m:
+                    port = int(m.group('port'))
+                    if port >= 3456 and port < 5900:
+                        self.gem5_port = port
+                        f.close()
+                        break
+            else:
+                time.sleep(1)
+            f.close()
+
+    def connect(self):  # pylint: disable=R0912
+        """
+        Connect to the gem5 simulation and wait for Android to boot. Then,
+        create checkpoints, and mount the VirtIO device.
+        """
+        self.connect_gem5()
+
+        self.logger.info("Waiting for Android to boot...")
+        while True:
+            try:
+                available = (1 == int('0' + self.gem5_shell('getprop sys.boot_completed', check_exit_code=False)))
+                if available:
+                    break
+            except (DeviceError, ValueError):
+                pass
+            time.sleep(60)
+
+        self.logger.info("Android booted")
+
+        if self.run_delay:
+            self.logger.info("Sleeping for {} seconds in the guest".format(self.run_delay))
+            self.gem5_shell("sleep {}".format(self.run_delay))
+
+        if self.checkpoint:
+            self.checkpoint_gem5()
+
+        self.mount_virtio()
+        self.logger.info("Creating the working directory in the simulated system")
+        self.gem5_shell('mkdir -p {}'.format(self.working_directory))
+        self._is_ready = True
+
+    def connect_gem5(self):  # pylint: disable=R0912
+        """
+        Connect to the telnet port of the gem5 simulation.
+
+        We connect, and wait for the prompt to be found. We do not use a timeout
+        for this, and wait for the prompt in a while loop as the gem5 simulation
+        can take many hours to reach a prompt when booting the system. We also
+        inject some newlines periodically to try and force gem5 to show a
+        prompt. Once the prompt has been found, we replace it with a unique
+        prompt to ensure that we are able to match it properly. We also disable
+        the echo as this simplifies parsing the output when executing commands
+        on the device.
+        """
+        self.logger.info("Connecting to the gem5 simulation on port {}".format(self.gem5_port))
+        host = socket.gethostname()
+        port = self.gem5_port
+
+        # Connect to the gem5 telnet port. Use a short timeout here.
+        self.sckt = ssh.TelnetConnection()
+        self.sckt.login(host, 'None', port=port, auto_prompt_reset=False,
+                        login_timeout=10)
+
+        self.logger.info("Connected! Waiting for prompt...")
+
+        # We need to find the prompt. It might be different if we are resuming
+        # from a checkpoint. Therefore, we test multiple options here.
+        prompt_found = False
+        while not prompt_found:
+            try:
+                # Try and force a prompt to be shown
+                self.sckt.send('\n')
+                self.sckt.expect([r'# ', self.sckt.UNIQUE_PROMPT], timeout=self.delay)
+                prompt_found = True
+            except TIMEOUT:
+                pass
+
+        self.logger.info("Setting unique prompt...")
+
+        self.sckt.set_unique_prompt()
+        self.sckt.prompt()
+        self.logger.info("Prompt found and replaced with a unique string")
+
+        self.sckt.setecho(False)
+        self.sync_gem5_shell()
+
+    def disconnect(self):
+        """
+        Close and disconnect from the gem5 simulation. Additionally, we remove
+        the temporary directory used to pass files into the simulation.
+        """
+        self.logger.info("Gracefully terminating the gem5 simulation.")
+        try:
+            self.gem5_util("exit")
+            self.gem5.wait()
+        except EOF:
+            pass
+        self.logger.info("Removing the temporary directory")
+        try:
+            shutil.rmtree(self.temp_dir)
+        except OSError:
+            self.logger.warn("Failed to remove the temporary directory!")
+
+    def close(self):
+        if self._logcat_poller:
+            self._logcat_poller.stop()
+
+    def reset(self):
+        self.logger.warn("Attempt to restart the gem5 device. This is not "
+                         "supported!")
+
+    def init(self):
+        pass
+
+    def push_file(self, source, dest, as_root=False):  # pylint: disable=W0221
+        """
+        Push a file to the gem5 device using VirtIO
+
+        The file to push to the device is copied to the temporary directory on
+        the host, before being copied within the simulation to the destination.
+        Checks, in the form of 'ls' with error code checking, are performed to
+        ensure that the file is copied to the destination.
+        """
+        filename = os.path.basename(source)
+        self.logger.debug("Pushing {} to device.".format(source))
+        self.logger.debug("temp_dir: {}".format(self.temp_dir))
+        self.logger.debug("dest: {}".format(dest))
+        self.logger.debug("filename: {}".format(filename))
+
+        # We need to copy the file to copy to the temporary directory
+        self.move_to_temp_dir(source)
+
+        # Back to the gem5 world
+        self.gem5_shell("ls -al /mnt/obb/{}".format(filename))
+        self.gem5_shell("busybox cp /mnt/obb/{} {}".format(filename, dest))
+        self.gem5_shell("busybox sync")
+        self.gem5_shell("ls -al {}".format(dest))
+        self.gem5_shell("ls -al /mnt/obb/")
+        self.logger.debug("Push complete.")
+
+    def pull_file(self, source, dest, as_root=False):  # pylint: disable=W0221
+        """
+        Pull a file from the gem5 device using m5 writefile
+
+        First, we check the extension of the file to be copied. If the file ends
+        in .gz, then gem5 wrongly assumes that it should create a gzipped output
+        stream, which results in a gem5 error. Therefore, we rename the file on
+        the local device prior to the writefile command when required. Next, the
+        file is copied to the local directory within the guest as the m5
+        writefile command assumes that the file is local. The file is then
+        written out to the host system using writefile, prior to being moved to
+        the destination on the host.
+        """
+        filename = source.split('/')[-1]
+        self.logger.debug("Pulling {} from device.".format(filename))
+
+        # gem5 assumes that files ending in .gz are gzip-compressed. We need to
+        # work around this, else gem5 panics on us. Rename the file for use in
+        # gem5
+        if filename[-3:] == '.gz':
+            filename += '.fugem5'
+
+        self.logger.debug("pull_file {} {}".format(source, filename))
+        # We don't check the exit code here because it is non-zero if the source
+        # and destination are the same. The ls below will cause an error if the
+        # file was not where we expected it to be.
+        self.gem5_shell("busybox cp {} {}".format(source, filename), check_exit_code=False)
+        self.gem5_shell("busybox sync")
+        self.gem5_shell("ls -la {}".format(filename))
+        self.logger.debug('Finished the copy in the simulator')
+        self.gem5_util("writefile {}".format(filename))
+
+        if 'cpu' not in filename:
+            while not os.path.exists(os.path.join(self.gem5outdir, filename)):
+                time.sleep(1)
+
+        # Perform the local move
+        shutil.move(os.path.join(self.gem5outdir, filename), dest)
+        self.logger.debug("Pull complete.")
+
+    def delete_file(self, filepath, as_root=False):  # pylint: disable=W0221
+        """ Delete a file on the device """
+        self._check_ready()
+        self.gem5_shell("rm '{}'".format(filepath))
+
+    def file_exists(self, filepath):
+        """ Check if a file exists """
+        self._check_ready()
+        output = self.gem5_shell('if [ -e \'{}\' ]; then echo 1; else echo 0; fi'.format(filepath))
+        try:
+            if int(output):
+                return True
+            else:
+                return False
+        except ValueError:
+            # If we cannot process the output, assume that there is no file
+            return False
+
+    def install(self, filepath, timeout=default_timeout):  # pylint: disable=W0221
+        """ Install an APK or a normal executable """
+        ext = os.path.splitext(filepath)[1].lower()
+        if ext == '.apk':
+            return self.install_apk(filepath, timeout)
+        else:
+            return self.install_executable(filepath)
+
+    def install_apk(self, filepath, timeout=default_timeout):  # pylint: disable=W0221
+        """
+        Install an APK on the gem5 device
+
+        The APK is pushed to the device. Then the file and folder permissions
+        are changed to ensure that the APK can be correctly installed. The APK
+        is then installed on the device using 'pm'.
+        """
+        self._check_ready()
+        self.logger.info("Installing {}".format(filepath))
+        ext = os.path.splitext(filepath)[1].lower()
+        if ext == '.apk':
+            filename = os.path.basename(filepath)
+            on_device_path = os.path.join('/data/local/tmp', filename)
+            self.push_file(filepath, on_device_path)
+            # We need to make sure that the folder permissions are set
+            # correctly, else the APK does not install correctly.
+            self.gem5_shell('busybox chmod 775 /data/local/tmp')
+            self.gem5_shell('busybox chmod 774 {}'.format(on_device_path))
+            self.logger.debug("Actually installing the APK: {}".format(on_device_path))
+            return self.gem5_shell("pm install {}".format(on_device_path))
+        else:
+            raise DeviceError('Can\'t install {}: unsupported format.'.format(filepath))
+
+    def install_executable(self, filepath, with_name=None):
+        """ Install an executable """
+        executable_name = os.path.basename(filepath)
+        on_device_file = self.path.join(self.working_directory, executable_name)
+        on_device_executable = self.path.join(self.binaries_directory, executable_name)
+        self.push_file(filepath, on_device_file)
+        self.execute('busybox cp {} {}'.format(on_device_file, on_device_executable))
+        self.execute('busybox chmod 0777 {}'.format(on_device_executable))
+        return on_device_executable
+
+    def uninstall(self, package):
+        self._check_ready()
+        self.gem5_shell("pm uninstall {}".format(package))
+
+    def execute(self, command, timeout=default_timeout, check_exit_code=True, background=False,
+                as_root=False, busybox=False, **kwargs):
+        self._check_ready()
+        if as_root and not self.is_rooted:
+            raise DeviceError('Attempting to execute "{}" as root on unrooted device.'.format(command))
+        if busybox:
+            if not self.is_rooted:
+                raise DeviceError('Attempting to execute "{}" with busybox. '.format(command) +
+                                  'Busybox can only be deployed to rooted devices.')
+            command = ' '.join([self.busybox, command])
+        if background:
+            self.logger.debug("Attempt to execute in background. Not supported "
+                              "in gem5, hence ignored.")
+        return self.gem5_shell(command, as_root=as_root)
+
+    def dump_logcat(self, outfile, filter_spec=None):
+        """ Extract logcat from simulation """
+        self.logger.info("Extracting logcat from the simulated system")
+        filename = outfile.split('/')[-1]
+        command = 'logcat -d > {}'.format(filename)
+        self.gem5_shell(command)
+        self.pull_file("{}".format(filename), outfile)
+
+    def clear_logcat(self):
+        """Clear (flush) logcat log."""
+        if self._logcat_poller:
+            return self._logcat_poller.clear_buffer()
+        else:
+            return self.gem5_shell('logcat -c')
+
+    def disable_selinux(self):
+        """ Disable SELinux. Overridden as parent implementation uses ADB """
+        api_level = int(self.gem5_shell('getprop ro.build.version.sdk').strip())
+
+        # SELinux was added in Android 4.3 (API level 18). Trying to
+        # 'getenforce' in earlier versions will produce an error.
+        if api_level >= 18:
+            se_status = self.execute('getenforce', as_root=True).strip()
+            if se_status == 'Enforcing':
+                self.execute('setenforce 0', as_root=True)
+
+    def get_properties(self, context):  # pylint: disable=R0801
+        """ Get the property files from the device """
+        for propfile in self.property_files:
+            try:
+                normname = propfile.lstrip(self.path.sep).replace(self.path.sep, '.')
+                outfile = os.path.join(context.host_working_directory, normname)
+                if self.is_file(propfile):
+                    self.execute('cat {} > {}'.format(propfile, normname))
+                    self.pull_file(normname, outfile)
+                elif self.is_directory(propfile):
+                    self.get_directory(context, propfile)
+                    continue
+                else:
+                    continue
+            except DeviceError:
+                # We pull these files "opportunistically", so if a pull fails
+                # (e.g. we don't have permissions to read the file), just note
+                # it quietly (not as an error/warning) and move on.
+                self.logger.debug('Could not pull property file "{}"'.format(propfile))
+
+        # As we do not call the super class, we explicitly need to
+        # process the Android properties.
+        props = self._get_android_properties(context)
+
+    def get_directory(self, context, directory):
+        """ Pull a directory from the device """
+        normname = directory.lstrip(self.path.sep).replace(self.path.sep, '.')
+        outdir = os.path.join(context.host_working_directory, normname)
+        temp_file = os.path.join(context.host_working_directory, "{}.tar".format(normname))
+        # Check that the folder exists
+        self.gem5_shell("ls -la {}".format(directory))
+        # Compress the folder
+        try:
+            self.gem5_shell("{} tar -cvf {}.tar {}".format(self.busybox, normname, directory))
+        except DeviceError:
+            self.logger.debug("Failed to run tar command on device! Not pulling {}".format(directory))
+            return
+        self.pull_file(normname, temp_file)
+        f = tarfile.open(temp_file, 'r')
+        os.mkdir(outdir)
+        f.extractall(outdir)
+        os.remove(temp_file)
+
+    def get_pids_of(self, process_name):
+        """ Returns a list of PIDs of all processes with the specified name. """
+        result = self.gem5_shell('ps | busybox grep {}'.format(process_name),
+                                 check_exit_code=False).strip()
+        if result and 'not found' not in result and len(result.split('\n')) > 2:
+            return [int(x.split()[1]) for x in result.split('\n')]
+        else:
+            return []
+
+    def disable_screen_lock(self):
+        """
+        Attempts to disable he screen lock on the device.
+
+        Overridden here as otherwise we have issues with too many backslashes.
+        """
+        lockdb = '/data/system/locksettings.db'
+        sqlcommand = "update locksettings set value=\'0\' where name=\'screenlock.disabled\';"
+        self.execute('sqlite3 {} "{}"'.format(lockdb, sqlcommand), as_root=True)
+
+    # gem5 should dump out a framebuffer. We can use this if it exists. Failing
+    # that, fall back to the parent class implementation.
+    def capture_screen(self, filepath):
+        file_list = os.listdir(self.gem5outdir)
+        screen_caps = []
+        for f in file_list:
+            if '.bmp' in f:
+                screen_caps.append(f)
+
+        if len(screen_caps) == 1:
+            # Bail out if we do not have image, and resort to the slower, built
+            # in method.
+            try:
+                import Image
+                gem5_image = os.path.join(self.gem5outdir, screen_caps[0])
+                temp_image = os.path.join(self.gem5outdir, "file.png")
+                im = Image.open(gem5_image)
+                im.save(temp_image, "PNG")
+                shutil.copy(temp_image, filepath)
+                os.remove(temp_image)
+                self.logger.debug("capture_screen: using gem5 screencap")
+                return
+            except (shutil.Error, ImportError, IOError):
+                pass
+
+        # If we didn't manage to do the above, call the parent class.
+        self.logger.warning("capture_screen: falling back to parent class implementation")
+        super(Gem5Device, self).capture_screen(filepath)
+
+    # gem5 might be slow. Hence, we need to make the ping timeout very long.
+    def ping(self):
+        self.logger.debug("Pinging gem5 to see if it is still alive")
+        self.gem5_shell('ls /', timeout=self.longdelay)
+
+    # Additional Android-specific methods.
+    def forward_port(self, from_port, to_port):
+        self.logger.warning('Tried to forward port. We do not need any forwarding.')
+
+    # Internal methods: do not use outside of the class.
+
+    def _check_ready(self):
+        """
+        Check if the device is ready.
+
+        As this is gem5, we just assume that the device is ready once we have
+        connected to the gem5 simulation, and updated the prompt.
+        """
+        if not self._is_ready:
+            raise DeviceError('Device not ready.')
+
+    def gem5_shell(self, command, as_root=False, timeout=None, check_exit_code=True, sync=True):  # pylint: disable=R0912
+        """
+        Execute a command in the gem5 shell
+
+        This wraps the telnet connection to gem5 and processes the raw output.
+
+        This method waits for the shell to return, and then will try and
+        separate the output from the command from the command itself. If this
+        fails, warn, but continue with the potentially wrong output.
+
+        The exit code is also checked by default, and non-zero exit codes will
+        raise a DeviceError.
+        """
+        conn = self.sckt
+        if sync:
+            self.sync_gem5_shell()
+
+        self.logger.debug("gem5_shell command: {}".format(command))
+
+        # Send the actual command
+        conn.send("{}\n".format(command))
+
+        # Wait for the response. We just sit here and wait for the prompt to
+        # appear, as gem5 might take a long time to provide the output. This
+        # avoids timeout issues.
+        command_index = -1
+        while command_index == -1:
+            if conn.prompt():
+                output = re.sub(r' \r([^\n])', r'\1', conn.before)
+                output = re.sub(r'[\b]', r'', output)
+                # Deal with line wrapping
+                output = re.sub(r'[\r].+?<', r'', output)
+                command_index = output.find(command)
+
+                # If we have -1, then we cannot match the command, but the
+                # prompt has returned. Hence, we have a bit of an issue. We
+                # warn, and return the whole output.
+                if command_index == -1:
+                    self.logger.warn("gem5_shell: Unable to match command in "
+                                     "command output. Expect parsing errors!")
+                    command_index = 0
+
+        output = output[command_index + len(command):].strip()
+
+        # It is possible that gem5 will echo the command. Therefore, we need to
+        # remove that too!
+        command_index = output.find(command)
+        if command_index != -1:
+            output = output[command_index + len(command):].strip()
+
+        self.logger.debug("gem5_shell output: {}".format(output))
+
+        # We get a second prompt. Hence, we need to eat one to make sure that we
+        # stay in sync. If we do not do this, we risk getting out of sync for
+        # slower simulations.
+        self.sckt.expect(self.sckt.UNIQUE_PROMPT, timeout=10000)
+
+        if check_exit_code:
+            exit_code_text = self.gem5_shell('echo $?', as_root=as_root,
+                                             timeout=timeout, check_exit_code=False,
+                                             sync=False)
+            try:
+                exit_code = int(exit_code_text.split()[0])
+                if exit_code:
+                    message = 'Got exit code {}\nfrom: {}\nOUTPUT: {}'
+                    raise DeviceError(message.format(exit_code, command, output))
+            except (ValueError, IndexError):
+                self.logger.warning('Could not get exit code for "{}",\ngot: "{}"'.format(command, exit_code_text))
+
+        return output
+
+    def gem5_util(self, command):
+        """ Execute a gem5 utility command using the m5 binary on the device """
+        self.gem5_shell('/sbin/m5 ' + command)
+
+    def sync_gem5_shell(self):
+        """
+        Synchronise with the gem5 shell.
+
+        Write some unique text to the gem5 device to allow us to synchronise
+        with the shell output. We actually get two prompts so we need to match
+        both of these.
+        """
+        self.sckt.send("echo \*\*sync\*\*\n")
+        self.sckt.expect(r"\*\*sync\*\*", timeout=self.delay)
+        self.sckt.expect(self.sckt.UNIQUE_PROMPT, timeout=self.delay)
+        self.sckt.expect(self.sckt.UNIQUE_PROMPT, timeout=self.delay)
+
+    def move_to_temp_dir(self, source):
+        """
+        Move a file to the temporary directory on the host for copying to the
+        gem5 device
+        """
+        command = "cp {} {}".format(source, self.temp_dir)
+        self.logger.debug("Local copy command: {}".format(command))
+        subprocess.call(command.split())
+        subprocess.call("sync".split())
+
+    def checkpoint_gem5(self, end_simulation=False):
+        """ Checkpoint the gem5 simulation, storing all system state """
+        self.logger.info("Taking a post-boot checkpoint")
+        self.gem5_util("checkpoint")
+        if end_simulation:
+            self.disconnect()
+
+    def mount_virtio(self):
+        """
+        Mount the VirtIO device in the simulated system.
+        """
+        self.logger.info("Mounting VirtIO device in simulated system")
+
+        mount_command = "mount -t 9p -o trans=virtio,version=9p2000.L,aname={} gem5 /mnt/obb".format(self.temp_dir)
+        self.gem5_shell('busybox {}'.format(mount_command))

wlauto/utils/ssh.py

@@ -62,15 +62,20 @@ class TelnetConnection(pxssh.pxssh):
         cmd = 'telnet -l {} {} {}'.format(username, server, port)
 
         spawn._spawn(self, cmd)  # pylint: disable=protected-access
+        try:
             i = self.expect('(?i)(?:password)', timeout=login_timeout)
             if i == 0:
                 self.sendline(password)
                 i = self.expect([original_prompt, 'Login incorrect'], timeout=login_timeout)
-        else:
-            raise pxssh.ExceptionPxssh('could not log in: did not see a password prompt')
-
             if i:
                 raise pxssh.ExceptionPxssh('could not log in: password was incorrect')
+        except TIMEOUT:
+            if not password:
+                # There was no password prompt before TIMEOUT, and we didn't
+                # have a password to enter. Assume everything is OK.
+                pass
+            else:
+                raise pxssh.ExceptionPxssh('could not log in: did not see a password prompt')
 
         if not self.sync_original_prompt(sync_multiplier):
             self.close()