Hmm...going further, the only way I see to deal with this at the nxgl layer above the lcd structure itself is to add a nx_redraw with corresponding NX_EVENT_REDRAWING/NXEVENT_REDRAWN event callbacks, but that makes the nxgl layer device-aware...I don't see how it can't be really, these things are pretty different to traditional LCDs. For the case of the lcd nx_updatedisplay member not being present I would just return the NXEVENT_REDRAWN immediately so everything would remain back-compatible.
And you don't want to modified in the graphics interface unless you are also will to modify and test all of the graphic applications in apps/graphics that use it. There won't be any special change to the graphic system to support your case.
If you could explain what you think this nx_displayupdate() function would do, that would also be helpful.
Greg
