3.6.11. Weston

The supported Wayland/Weston version brings in the multiple display support in extended desktop mode and the ability to drag-and-drop windows from one display to the other.

Weston has support for multiple backends. By default it will use the drm backend unless the WAYLAND_DISPLAY environment variable is set. This backend will register the compositor as the controller of the kms interface and will pick up human interface device (HID) input using evdev.

If the WAYLAND_DISPLAY variable is set, Weston will attempt to use the wayland backend for nested composition. This is useful for development, but is normally not what you want for standard composition use. See Starting Weston Manually or the upstream weston documentation for more information.

3.6.11.1. Starting Weston with Emptty

Starting with SDK 11.0, the preferred way to start Weston is with the weston user using the display manager emptty. Emptty is a console based display manager that coordinates the loading of devices with the initialization of any specified graphical environment. By default, it is configured to automatically start weston under the weston user on device startup.

If you need to interact with this instance using any other user then make sure that user is capable of interacting with the wayland socket wayland-1 under the weston user’s XDG_RUNTIME_DIR, /run/user/1000/. We do not recommend running graphical applications as root.

To start the systemd service manually, do the following:

# systemctl start emptty

To inspect the systemd service status, do the following:

# systemctl status emptty

3.6.11.2. Starting Weston Manually

To launch Weston manually with the DRM backend, do the following:

On the default display:

# weston --display=<default connector-id>

On the secondary display:

# weston --display=<secondary connector-id>

On all connected displays (LCD and HDMI):

# weston

By default, the screensaver timeout is configured to 300 seconds. The user can change the screensaver timeout using a command line option:

--idle-time=<number of seconds>

For example, to set timeout of 10 minutes and Weston configured to display on all connectors, use the below command:

# weston --idle-time=600

To disable the screen timeout and to configure Weston to display on all connectors, use the below command:

# weston --idle-time=0

If you face any issues with the above procedure, please refer to the upstream weston documentation for troubleshooting tips.

The filesystem comes with a preconfigured weston.ini file which will be located at /etc/xdg/weston/weston.ini

3.6.11.3. Stopping Weston

Terminate all Weston clients before exiting Weston. If you have invoked Weston from the serial console, exit Weston by pressing Ctrl-C.

If Weston was started automatically by the display manager then it can be stopped with:

# systemctl stop emptty

It is also possible to invoke Weston from the native console, exit Weston by pressing Ctrl-Alt-Backspace.

3.6.11.4. Running Weston clients

Weston client examples can run from the command line on a serial port console or an SSH console. After launching Weston, the user should be able to use the keyboard and the mouse for various controls.

# /usr/bin/weston-flower
# /usr/bin/weston-clickdot
# /usr/bin/weston-cliptest
# /usr/bin/weston-dnd
# /usr/bin/weston-editor
# /usr/bin/weston-eventdemo
# /usr/bin/weston-image /usr/share/weston/terminal.png
# /usr/bin/weston-resizor
# /usr/bin/weston-simple-egl
# /usr/bin/weston-simple-shm
# /usr/bin/weston-simple-touch
# /usr/bin/weston-smoke
# /usr/bin/weston-info
# /usr/bin/weston-terminal

3.6.11.5. Running multimedia with Wayland sink

The GStreamer video sink for Wayland is the waylandsink. To use this video-sink for video playback:

# gst-launch-1.0 playbin uri=file://<path-to-file-name> video-sink=waylandsink

3.6.11.6. Using IVI shell feature

The SDK also has support for configuring Weston ivi-shell. The default shell that is configured in the SDK is the desktop-shell.

To change the shell to ivi-shell, the user will have to add the following lines into the /etc/xdg/weston/weston.ini.

To switch back to the desktop-shell can be done by commenting these lines in the /etc/xdg/weston/weston.ini (comments begin with a ‘#’ at the start of line).

[core]
shell=ivi-shell.so

After the above configuration is completed, we can restart Weston by running the following command:

# systemctl restart emptty

Note

When Weston starts with ivi-shell, the default background is black, this is different from the desktop-shell that brings up a window with background.

With ivi-shell configured for Weston, Wayland client applications use ivi-application protocol to be managed by a central HMI window management.

Applications must support the ivi_application Wayland protocol to be managed by the HMI central controller with an unique numeric ID.

Some important references to Weston IVI-shell can be found at the following link: