simple frame buffer
simplefb* at fdt?
wsdisplay* at simplefb?
simplefb driver supports the frame
buffer set up by firmware or the bootloader on systems that use a device
tree to describe the hardware.
simplefb driver interfaces the frame
buffer with the wscons(4) console framework. It does not provide direct device driver
entry points but makes its functions available via the internal
intro(4), wscons(4), wsdisplay(4)