Pluggable frame buffer devices

[Hans Petter Selasky]

Hi Shawn,

I've just put some more pieces into the kernel.

https://svnweb.freebsd.org/changeset/base/279752
https://svnweb.freebsd.org/changeset/base/279753

Can you give the current code a spin?

To get X.org/X11 working simply create a config file under 
/usr/local/etc/X11/xorg.conf.d which contains the device section given 
by "man xf86-video-scfb".

Open issues:

- Restoring the frame buffer does not always work. I looks like the 
restored text console size is 1x1 afterwards. At least there is no 
panic. And you can re-plug the UDL device again.

- You need to unplug the UDL device before rebooting.

- UDL device must be connected to a monitor before you plug it to USB, 
or you can load/unload the driver to re-probe the video format.

--HPS