Which components, required to run a working Linux w/ UI Layer (X/Wayland/DirectFB or FB, etc. - i.e. anything supported by GTK/QT) are not yet available as fully FOSS?
As for the rest, where is what, in detail? Where are the out-of-tree kernel drivers? Which are the required in-tree kernel drivers? Which graphics system can be used and is best be used (I assume it's currently X11)?