Load and save the display backlight brightness at boot and shutdown
/lib/systemd/systemd-backlight
[email protected] is a service that restores the display backlight brightness at early boot and saves it at shutdown. On disk, the backlight brightness is stored in /var/lib/systemd/backlight/.
systemd-backlight understands the following kernel command line parameter:
systemd.restore_state=
Takes a boolean argument. Defaults to "1". If "0", does not restore the backlight settings on boot. However, settings will still be stored on shutdown.