[coreboot] SeaBIOS and the Geode LX framebuffer

Stephen Crocker scrocker at ampltd.com
Thu Oct 9 12:19:06 CEST 2008

Kevin O'Connor wrote:
> On Mon, Oct 06, 2008 at 08:32:15AM -0600, Jordan Crouse wrote:
>> On 04/10/08 21:59 -0400, Kevin O'Connor wrote:
>>> I'm not an expert on VGA, but I think it may be possible to implement
>>> a bare bones vgabios with only a couple of chip specific functions
> [...]
>> Not just a possibility - but a certainty.  Geode could be ported in a
>> matter of hours. 
> Hi Jordan,
> I've spent some time taking a closer look at this.  The bochs vgabios
> has a large number of in/out calls.  If the geode vga doesn't natively
> emulate the legacy in/out ports then I think there is a fair amount of
> work to port bochs vgabios to geode.

I have been looking at the Geode LX databook and on page 303, it lists 
the standard VGA I/O ports (3CC, 3C2, 3BA/3DA etc.) which I had 
previously assumed were emulated in the VSA.  If they are indeed 
implemented in hardware, it should be able to act as a standard VGA 
device.  However, this would make me wonder what the VGA emulation VSA 
is for.

If they are software I/O ports implemented in the VSA, an alternative 
would be to make an open-source VGA emulation module for OpenVSA. 
Unfortunately, my resources are too limited to attempt this task.

Just as a matter of curiosity, what is the licensing issue surrounding 
the VGA emulation code?  I understand that it is not open-source but is 
it available as a binary?

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