Platfom development mode needs write access on the RO image

1. Flashed the read only image (ubuntu-system) on the device
2. Devices Tab -> Advanced Tab -> Enable Platform Development

The process fails for the very obvious reason that the system is in read only mode.

The /userdata/.writable_image must be touched and the device should be rebooted in order to install the developer tools.

It is important to alert the developer that this operation will make the system writable, however the image updates on a writable system will lead to unknown results, so ion a manual update using apt-get will be necessary.

Disabling the Platform Developer Mode should remove the /userdata/.writable_image file and the system should be rebooted... or actually fo rthe best results it should be reflashed :)