Target

class devlib.target.Target(connection_settings=None, platform=None, working_directory=None, executables_directory=None, connect=True, modules=None, load_default_modules=True, shell_prompt=DEFAULT_SHELL_PROMPT, conn_cls=None)

Target is the primary interface to the remote device. All interactions with the device are performed via a Target instance, either directly, or via its modules or a wrapper interface (such as an Instrument).

Parameters:

• connection_settings – A dict that specifies how to connect to the remote device. Its contents depend on the specific Target type (used see Connection Types).
• platform – A Target defines interactions at Operating System level. A Platform describes the underlying hardware (such as CPUs available). If a Platform instance is not specified on Target creation, one will be created automatically and it will dynamically probe the device to discover as much about the underlying hardware as it can. See also Platform.
• working_directory –

  This is primary location for on-target file system interactions performed by devlib. This location must be readable and writable directly (i.e. without sudo) by the connection’s user account. It may or may not allow execution. This location will be created, if necessary, during setup().

  If not explicitly specified, this will be set to a default value depending on the type of Target

• executables_directory –

  This is the location to which devlib will install executable binaries (either during setup() or via an explicit install() call). This location must support execution (obviously). It should also be possible to write to this location, possibly with elevated privileges (i.e. on a rooted Linux target, it should be possible to write here with sudo, but not necessarily directly by the connection’s account). This location will be created, if necessary, during setup().

  This location does not need to be same as the system’s executables location. In fact, to prevent devlib from overwriting system’s defaults, it better if this is a separate location, if possible.

  If not explicitly specified, this will be set to a default value depending on the type of Target

• connect – Specifies whether a connections should be established to the target. If this is set to False, then connect() must be explicitly called later on before the Target instance can be used.
• modules –

  a list of additional modules to be installed. Some modules will try to install by default (if supported by the underlying target). Current default modules are hotplug, cpufreq, cpuidle, cgroups, and hwmon (See Modules).

  See modules documentation for more detail.

• load_default_modules – If set to False, default modules listed above will not attempt to load. This may be used to either speed up target instantiation (probing for initializing modules takes a bit of time) or if there is an issue with one of the modules on a particular device (the rest of the modules will then have to be explicitly specified in the modules).
• shell_prompt – This is a regular expression that matches the shell prompted on the target. This may be used by some modules that establish auxiliary connections to a target over UART.
• conn_cls – This is the type of connection that will be used to communicate with the device.

Target.core_names

This is a list containing names of CPU cores on the target, in the order in which they are index by the kernel. This is obtained via the underlying Platform.

Target.core_clusters

Some devices feature heterogeneous core configurations (such as ARM big.LITTLE). This is a list that maps CPUs onto underlying clusters. (Usually, but not always, clusters correspond to groups of CPUs with the same name). This is obtained via the underlying Platform.

Target.big_core

This is the name of the cores that are the “big”s in an ARM big.LITTLE configuration. This is obtained via the underlying Platform.

Target.little_core

This is the name of the cores that are the “little”s in an ARM big.LITTLE configuration. This is obtained via the underlying Platform.

Target.is_connected

A boolean value that indicates whether an active connection exists to the target device.

Target.connected_as_root

A boolean value that indicate whether the account that was used to connect to the target device is “root” (uid=0).

Target.is_rooted

A boolean value that indicates whether the connected user has super user privileges on the devices (either is root, or is a sudoer).

Target.kernel_version

The version of the kernel on the target device. This returns a KernelVersion instance that has separate version and release fields.

Target.os_version

This is a dict that contains a mapping of OS version elements to their values. This mapping is OS-specific.

Target.system_id

A unique identifier for the system running on the target. This identifier is intended to be uninque for the combination of hardware, kernel, and file system.

Target.model

The model name/number of the target device.

Target.cpuinfo

This is a Cpuinfo instance which contains parsed contents of /proc/cpuinfo.

Target.number_of_cpus

The total number of CPU cores on the target device.

Target.config

A KernelConfig instance that contains parsed kernel config from the target device. This may be None if kernel config could not be extracted.

Target.user

The name of the user logged in on the target device.

Target.conn

The underlying connection object. This will be None if an active connection does not exist (e.g. if connect=False as passed on initialization and connect() has not been called).

Note

a Target will automatically create a connection per thread. This will always be set to the connection for the current thread.

Target.connect([timeout])

Establish a connection to the target. It is usually not necessary to call this explicitly, as a connection gets automatically established on instantiation.

Target.disconnect()

Disconnect from target, closing all active connections to it.

Target.get_connection([timeout])

Get an additional connection to the target. A connection can be used to execute one blocking command at time. This will return a connection that can be used to interact with a target in parallel while a blocking operation is being executed.

This should not be used to establish an initial connection; use connect() instead.

Note

Target will automatically create a connection per thread, so you don’t normally need to use this explicitly in threaded code. This is generally useful if you want to perform a blocking operation (e.g. using background()) while at the same time doing something else in the same host-side thread.

Target.setup([executables])

This will perform an initial one-time set up of a device for devlib interaction. This involves deployment of tools relied on the Target, creation of working locations on the device, etc.

Usually, it is enough to call this method once per new device, as its effects will persist across reboots. However, it is safe to call this method multiple times. It may therefore be a good practice to always call it once at the beginning of a script to ensure that subsequent interactions will succeed.

Optionally, this may also be used to deploy additional tools to the device by specifying a list of binaries to install in the executables parameter.

Target.reboot([hard[, connect[, timeout]]])

Reboot the target device.

Parameters:

• hard – A boolean value. If True a hard reset will be used instead of the usual soft reset. Hard reset must be supported (usually via a module) for this to work. Defaults to False.
• connect – A boolean value. If True, a connection will be automatically established to the target after reboot. Defaults to True.
• timeout – If set, this will be used by various (platform-specific) operations during reboot process to detect if the reboot has failed and the device has hung.

Target.push(source, dest[, as_root, timeout])

Transfer a file from the host machine to the target device.

Parameters:

• source – path of to the file on the host
• dest – path of to the file on the target
• as_root – whether root is required. Defaults to false.
• timeout – timeout (in seconds) for the transfer; if the transfer does not complete within this period, an exception will be raised.

Target.pull(source, dest[, as_root, timeout])

Transfer a file from the target device to the host machine.

Parameters:

• source – path of to the file on the target
• dest – path of to the file on the host
• as_root – whether root is required. Defaults to false.
• timeout – timeout (in seconds) for the transfer; if the transfer does not complete within this period, an exception will be raised.

Target.execute(command[, timeout[, check_exit_code[, as_root[, strip_colors[, will_succeed[, force_locale]]]]]])

Execute the specified command on the target device and return its output.

Parameters:

• command – The command to be executed.
• timeout – Timeout (in seconds) for the execution of the command. If specified, an exception will be raised if execution does not complete with the specified period.
• check_exit_code – If True (the default) the exit code (on target) from execution of the command will be checked, and an exception will be raised if it is not 0.
• as_root – The command will be executed as root. This will fail on unrooted targets.
• strip_colours – The command output will have colour encodings and most ANSI escape sequences striped out before returning.
• will_succeed – The command is assumed to always succeed, unless there is an issue in the environment like the loss of network connectivity. That will make the method always raise an instance of a subclass of DevlibTransientError when the command fails, instead of a DevlibStableError.
• force_locale – Prepend LC_ALL=<force_locale> in front of the command to get predictable output that can be more safely parsed. If None, no locale is prepended.

Target.background(command[, stdout[, stderr[, as_root]]])

Execute the command on the target, invoking it via subprocess on the host. This will return subprocess.Popen instance for the command.

Parameters:

• command – The command to be executed.
• stdout – By default, standard output will be piped from the subprocess; this may be used to redirect it to an alternative file handle.
• stderr – By default, standard error will be piped from the subprocess; this may be used to redirect it to an alternative file handle.
• as_root – The command will be executed as root. This will fail on unrooted targets.

Note

This will block the connection until the command completes.

Target.invoke(binary[, args[, in_directory[, on_cpus[, as_root[, timeout]]]]])

Execute the specified binary on target (must already be installed) under the specified conditions and return the output.

Parameters:

• binary – binary to execute. Must be present and executable on the device.
• args – arguments to be passed to the binary. The can be either a list or a string.
• in_directory – execute the binary in the specified directory. This must be an absolute path.
• on_cpus – taskset the binary to these CPUs. This may be a single int (in which case, it will be interpreted as the mask), a list of ints, in which case this will be interpreted as the list of cpus, or string, which will be interpreted as a comma-separated list of cpu ranges, e.g. "0,4-7".
• as_root – Specify whether the command should be run as root
• timeout – If this is specified and invocation does not terminate within this number of seconds, an exception will be raised.

Target.background_invoke(binary[, args[, in_directory[, on_cpus[, as_root]]]])

Execute the specified binary on target (must already be installed) as a background task, under the specified conditions and return the subprocess.Popen instance for the command.

Parameters:

• binary – binary to execute. Must be present and executable on the device.
• args – arguments to be passed to the binary. The can be either a list or a string.
• in_directory – execute the binary in the specified directory. This must be an absolute path.
• on_cpus – taskset the binary to these CPUs. This may be a single int (in which case, it will be interpreted as the mask), a list of ints, in which case this will be interpreted as the list of cpus, or string, which will be interpreted as a comma-separated list of cpu ranges, e.g. "0,4-7".
• as_root – Specify whether the command should be run as root

Target.kick_off(command[, as_root])

Kick off the specified command on the target and return immediately. Unlike background() this will not block the connection; on the other hand, there is not way to know when the command finishes (apart from calling ps()) or to get its output (unless its redirected into a file that can be pulled later as part of the command).

Parameters:

• command – The command to be executed.
• as_root – The command will be executed as root. This will fail on unrooted targets.

Target.read_value(path[, kind])

Read the value from the specified path. This is primarily intended for sysfs/procfs/debugfs etc.

Parameters:

• path – file to read
• kind – Optionally, read value will be converted into the specified kind (which should be a callable that takes exactly one parameter).

Target.read_int(self, path)

Equivalent to Target.read_value(path, kind=devlib.utils.types.integer)

Target.read_bool(self, path)

Equivalent to Target.read_value(path, kind=devlib.utils.types.boolean)

Target.write_value(path, value[, verify])

Write the value to the specified path on the target. This is primarily intended for sysfs/procfs/debugfs etc.

Parameters:

• path – file to write into
• value – value to be written
• verify – If True (the default) the value will be read back after it is written to make sure it has been written successfully. This due to some sysfs entries silently failing to set the written value without returning an error code.

Target.revertable_write_value(path, value[, verify])

Same as Target.write_value(), but as a context manager that will write back the previous value on exit.

Target.batch_revertable_write_value(kwargs_list)

Calls Target.revertable_write_value() with all the keyword arguments dictionary given in the list. This is a convenience method to update multiple files at once, leaving them in their original state on exit. If one write fails, all the already-performed writes will be reverted as well.

Target.read_tree_values(path, depth=1, dictcls=dict[, tar[, decode_unicode[, strip_null_char]]])

Read values of all sysfs (or similar) file nodes under path, traversing up to the maximum depth depth.

Returns a nested structure of dict-like objects (dicts by default) that follows the structure of the scanned sub-directory tree. The top-level entry has a single item who’s key is path. If path points to a single file, the value of the entry is the value ready from that file node. Otherwise, the value is a dict-line object with a key for every entry under path mapping onto its value or further dict-like objects as appropriate.

Although the default behaviour should suit most users, it is possible to encounter issues when reading binary files, or files with colons in their name for example. In such cases, the tar parameter can be set to force a full archive of the tree using tar, hence providing a more robust behaviour. This can, however, slow down the read process significantly.

Parameters:

• path – sysfs path to scan
• depth – maximum depth to descend
• dictcls – a dict-like type to be used for each level of the hierarchy.
• tar – the files will be read using tar rather than grep
• decode_unicode – decode the content of tar-ed files as utf-8
• strip_null_char – remove null chars from utf-8 decoded files

Target.read_tree_values_flat(path, depth=1)

Read values of all sysfs (or similar) file nodes under path, traversing up to the maximum depth depth.

Returns a dict mapping paths of file nodes to corresponding values.

Parameters:

• path – sysfs path to scan
• depth – maximum depth to descend

Target.reset()

Soft reset the target. Typically, this means executing reboot on the target.

Target.check_responsive()

Returns True if the target appears to be responsive and False otherwise.

Target.kill(pid[, signal[, as_root]])

Kill a process on the target.

Parameters:

• pid – PID of the process to be killed.
• signal – Signal to be used to kill the process. Defaults to signal.SIGTERM.
• as_root – If set to True, kill will be issued as root. This will fail on unrooted targets.

Target.killall(name[, signal[, as_root]])

Kill all processes with the specified name on the target. Other parameters are the same as for kill().

Target.get_pids_of(name)

Return a list of PIDs of all running instances of the specified process.

Target.ps()

Return a list of PsEntry instances for all running processes on the system.

Target.file_exists(self, filepath)

Returns True if the specified path exists on the target and False otherwise.

Target.list_file_systems()

Lists file systems mounted on the target. Returns a list of FstabEntrys.

Target.list_directory(path[, as_root])

List (optionally, as root) the contents of the specified directory. Returns a list of strings.

Target.get_workpath(self, path)

Convert the specified path to an absolute path relative to working_directory on the target. This is a shortcut for t.path.join(t.working_directory, path)

Target.tempfile([prefix[, suffix]])

Get a path to a temporary file (optionally, with the specified prefix and/or suffix) on the target.

Target.remove(path[, as_root])

Delete the specified path on the target. Will work on files and directories.

Target.core_cpus(core)

Return a list of numeric cpu IDs corresponding to the specified core name.

Target.list_online_cpus([core])

Return a list of numeric cpu IDs for all online CPUs (optionally, only for CPUs corresponding to the specified core).

Target.list_offline_cpus([core])

Return a list of numeric cpu IDs for all offline CPUs (optionally, only for CPUs corresponding to the specified core).

Target.getenv(variable)

Return the value of the specified environment variable on the device

Target.capture_screen(filepath)

Take a screenshot on the device and save it to the specified file on the host. This may not be supported by the target. You can optionally insert a {ts} tag into the file name, in which case it will be substituted with on-target timestamp of the screen shot in ISO8601 format.

Target.install(filepath[, timeout[, with_name]])

Install an executable on the device.

Parameters:

• filepath – path to the executable on the host
• timeout – Optional timeout (in seconds) for the installation
• with_name – This may be used to rename the executable on the target

Target.install_if_needed(host_path, search_system_binaries=True)

Check to see if the binary is already installed on the device and if not, install it.

Parameters:

• host_path – path to the executable on the host
• search_system_binaries – Specify whether to search the devices PATH when checking to see if the executable is installed, otherwise only check user installed binaries.

Target.uninstall(name)

Uninstall the specified executable from the target

Target.get_installed(name)

Return the full installation path on the target for the specified executable, or None if the executable is not installed.

Target.which(name)

Alias for get_installed()

Target.is_installed(name)

Returns True if an executable with the specified name is installed on the target and False other wise.

Target.extract(path, dest=None)

Extracts the specified archive/file and returns the path to the extracted contents. The extraction method is determined based on the file extension. zip, tar, gzip, and bzip2 are supported.

Parameters:dest –

Specified an on-target destination directory (which must exist)

for the extracted contents.

Returns the path to the extracted contents. In case of files (gzip and bzip2), the path to the decompressed file is returned; for archives, the path to the directory with the archive’s contents is returned.

Target.is_network_connected()

Checks for internet connectivity on the device. This doesn’t actually guarantee that the internet connection is “working” (which is rather nebulous), it’s intended just for failing early when definitively _not_ connected to the internet.

Returns:True if internet seems available, False otherwise.

Target.install_module(mod, **params)

Parameters:

• mod – The module name or object to be installed to the target.
• params –

  Keyword arguments used to instantiate the module.

  Installs an additional module to the target after the initial setup has been performed.

Linux Target

class devlib.target.LinuxTarget(connection_settings=None, platform=None, working_directory=None, executables_directory=None, connect=True, modules=None, load_default_modules=True, shell_prompt=DEFAULT_SHELL_PROMPT, conn_cls=SshConnection, is_container=False)

LinuxTarget is a subclass of Target with customisations specific to a device running linux.

Local Linux Target

class devlib.target.LocalLinuxTarget(connection_settings=None, platform=None, working_directory=None, executables_directory=None, connect=True, modules=None, load_default_modules=True, shell_prompt=DEFAULT_SHELL_PROMPT, conn_cls=SshConnection, is_container=False)

LocalLinuxTarget is a subclass of LinuxTarget with customisations specific to using the host machine running linux as the target.

Android Target

class devlib.target.AndroidTarget(connection_settings=None, platform=None, working_directory=None, executables_directory=None, connect=True, modules=None, load_default_modules=True, shell_prompt=DEFAULT_SHELL_PROMPT, conn_cls=AdbConnection, package_data_directory="/data/data")

AndroidTarget is a subclass of Target with additional features specific to a device running Android.

Parameters:package_data_directory – This is the location of the data stored for installed Android packages on the device.

AndroidTarget.set_rotation(rotation)

Specify an integer representing the desired screen rotation with the following mappings: Natural: 0, Rotated Left: 1, Inverted : 2 and Rotated Right : 3.

AndroidTarget.get_rotation(rotation)

Returns an integer value representing the orientation of the devices screen. 0 : Natural, 1 : Rotated Left, 2 : Inverted and 3 : Rotated Right.

AndroidTarget.set_natural_rotation()

Sets the screen orientation of the device to its natural (0 degrees) orientation.

AndroidTarget.set_left_rotation()

Sets the screen orientation of the device to 90 degrees.

AndroidTarget.set_inverted_rotation()

Sets the screen orientation of the device to its inverted (180 degrees) orientation.

AndroidTarget.set_right_rotation()

Sets the screen orientation of the device to 270 degrees.

AndroidTarget.set_auto_rotation(autorotate)

Specify a boolean value for whether the devices auto-rotation should be enabled.

AndroidTarget.get_auto_rotation()

Returns True if the targets auto rotation is currently enabled and False otherwise.

AndroidTarget.set_airplane_mode(mode)

Specify a boolean value for whether the device should be in airplane mode.

Note

Requires the device to be rooted if the device is running Android 7+.

AndroidTarget.get_airplane_mode()

Returns True if the target is currently in airplane mode and False otherwise.

AndroidTarget.set_brightness(value)

Sets the devices screen brightness to a specified integer between 0 and 255.

AndroidTarget.get_brightness()

Returns an integer between 0 and 255 representing the devices current screen brightness.

AndroidTarget.set_auto_brightness(auto_brightness)

Specify a boolean value for whether the devices auto brightness should be enabled.

AndroidTarget.get_auto_brightness()

Returns True if the targets auto brightness is currently enabled and False otherwise.

AndroidTarget.ensure_screen_is_off()

Checks if the devices screen is on and if so turns it off.

AndroidTarget.ensure_screen_is_on()

Checks if the devices screen is off and if so turns it on.

AndroidTarget.is_screen_on()

Returns True if the targets screen is currently on and False otherwise.

AndroidTarget.wait_for_target(timeout=30)

Returns when the devices becomes available withing the given timeout otherwise returns a TimeoutError.

AndroidTarget.reboot_bootloader(timeout=30)

Attempts to reboot the target into it’s bootloader.

AndroidTarget.homescreen()

Returns the device to its home screen.

AndroidTarget.swipe_to_unlock(direction="diagonal")

Performs a swipe input on the device to try and unlock the device. A direction of "horizontal", "vertical" or "diagonal" can be supplied to specify in which direction the swipe should be performed. By default "diagonal" will be used to try and support the majority of newer devices.

ChromeOS Target

class devlib.target.ChromeOsTarget(connection_settings=None, platform=None, working_directory=None, executables_directory=None, android_working_directory=None, android_executables_directory=None, connect=True, modules=None, load_default_modules=True, shell_prompt=DEFAULT_SHELL_PROMPT, package_data_directory="/data/data")

ChromeOsTarget is a subclass of LinuxTarget with additional features specific to a device running ChromeOS for example, if supported, its own android container which can be accessed via the android_container attribute. When making calls to or accessing properties and attributes of the ChromeOS target, by default they will be applied to Linux target as this is where the majority of device configuration will be performed and if not available, will fall back to using the android container if available. This means that all the available methods from LinuxTarget and AndroidTarget are available for ChromeOsTarget if the device supports android otherwise only the LinuxTarget methods will be available.

Parameters:

• working_directory – This is the location of the working directory to be used for the Linux target container. If not specified will default to "/mnt/stateful_partition/devlib-target".
• android_working_directory – This is the location of the working directory to be used for the android container. If not specified it will use the working directory default for AndroidTarget..
• android_executables_directory – This is the location of the executables directory to be used for the android container. If not specified will default to a bin subdirectory in the android_working_directory.
• package_data_directory – This is the location of the data stored for installed Android packages on the device.