The controller's firmware can be upgraded to a newer version by first uploading it, and the committing the upgrade.
Uploading the firmware
You can upload a file or specify a URI where it can be downloaded from. Be sure to disable the same subnet restriction if you intend to download firmware from a server not in your local network.
By default, the unit beeps and blinks during update. You can disable this.
Any files not specifically preserved are lost on upgrade. This includes manually installed packages; to attempt to automatically re-download and re-install them after a successful upgrade, enable the "Preserve user-installed packages on upgrade" feature.
You may protect the current firmware from modification. Pressing the hardware reset button will be required to unlock.
Committing the firmware upgrade
After the firmware has been uploaded, you are presented with a form to perform the upgrade.
You can double-check the firmware version. If you wish to cancel the upgrade, it's best to explicitly press 'cancel' in the form so that the uploaded file could be cleaned up.
When you start an upgrade, a message about this briefly appears on the LCD.
Further activity is indicated by a cycling pattern of 
signs.
After an upgrade has been completed, the unit is rebooted. The first boot may take longer than usual due to configuration updates.
