Ubuntu's Mir Gains Server-Side Platform Probing

The latest big feature landing in Ubuntu's Mir display server by Canonical is server-side platform probing support, which landed just before the weekend.

Server-side platform probing support touched a lot of Mir code and required a lot to get into place. Mir probes the modules in trying to determine if they can drive a given platform, which at least for now is limited to the Android layer with the various Android GPU drivers or otherwise on a conventional Linux system with Mesa drivers, otherwise it falls back to loading a stub platform.

This change also now yields mir-platform-graphics-mesa and mir-platform-graphics-android packages for Ubuntu systems. These new packages contain the shared libraries required for interacting with the hardware platform using Mesa or Android graphics drivers, respectively, and replace the former libmirplatform6driver-mesa and libmirplatform6driver-android packages.

The server-side platform probing for Mir landed on Friday with revision 2254 by Alan Griffiths.

Add server-side platform probing support.

Modules are checked in MIR_SERVER_PLATFORM_PATH, with configuration overrides available to both force a specific module and to check in a specific path.

Modules are probed to determine whether they can drive the available hardware. If a real platform - Android or Mesa - is capable of driving the hardware then it is used; otherwise the stub platform is loaded.