Alan Coopersmith managed to get the source for XSun released, and it includes the cg6 driver. You can see it here:
> Date: Tue, 10 Apr 2012 18:03:11 +0100
> From: mark.cave-ayland@ilande.co.uk
> To: openbios@openbios.org
> Subject: [OpenBIOS] OT: Brooktree IC used in cg3 graphics framebuffer?
>
> Hi all,
>
> A slightly off-topic question, however there may be some people on the
> list who will know the answer to this: what was the number of the
> Brooktree IC used on the cg3 framebuffer? According to various sources,
> it looks like the BT458 was used on the cg6 - is this the same as the cg3?
>
>
> ATB,
>
> Mark.
>
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