Currently it sleeps and waits for a mailbox interrupt after which it acks it and goes back to sleep. We're planning on using the interface to load a second stag

Currently it sleeps and waits for a mailbox interrupt after which it acks it and goes back to sleep. We're planning on using the interface to load a second stage firmware that would emulate the closed source firmware's power/clock management interfaces (but not framebuffer/PV/HVS/HDMI related stuff since there are Linux drivers for that now).