[OLPC-devel] Re: fbdev driver.

[Jordan Crouse]

On 30/05/06 20:47 -0400, Jim Gettys wrote:
> CosmicPenguin thinks the following may work on GX2.  Certainly worth a
> try. He also notes that the video controller needs to be told where the
> video memory lives; this would normally be done in the BIOS.

Specifically, offset 0x84 of the the display controller registers is
written to point to the framebuffer memory.  

Also of note is that the framebuffer driver currently uses PCI to grok
the register locations - those will need to be switched to static 
addresses if the PCI config space isn't used after all.

Finally - a patch just went out on the fbdev-devel list to get the size
of the framebuffer through a virtual register in the BIOS - that obviously
has no value to us, and if Linus merges it, we'll need to replace that with
a hard coded size value (again).  I believe Steve and Ron agreed on 8MB for
the framebuffer memory size - isn't that right?

Jordan

-- 
Jordan Crouse
Senior Linux Engineer
AMD - Personal Connectivity Solutions Group
<www.amd.com/embeddedprocessors>