Re: OpenGL-based framebuffer concepts
- From: "D. Hazelton" <dhazelton@xxxxxxxxx>
- Date: Wed, 24 May 2006 22:09:21 +0000
On Wednesday 24 May 2006 22:08, Matthew Garrett wrote:
On Tue, May 23, 2006 at 07:38:40PM -0400, Jon Smirl wrote:
2) The ROM support in the kernel knows about the shadow RAM copy at
C000::0. When you request the ROM from a laptop video system it
returns a map to the shadow RAM copy, not to a physical ROM. You need
access to the shadow RAM copy to get to things the BIOS left there
when it ran.
My experience is that, on some laptops, the code at c000:0003 may jump
into some other address block that isn't necessarily shadowed. There's
no reason to assume that POSTing an ancilliary ROM will work after the
system has left the BIOS. Further, my laptop doesn't appear to have a
rom entry in sysfs, which makes getting at stuff that way rather more
awkward...
As has been previously stated, the kernel should have already setup the
primary video card by that point. EDID information can be used to get
information about valid modes. I don't know of a single laptop that has
multiple video cards in it. If you do, please enlighten me.
DRH
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- Re: OpenGL-based framebuffer concepts
- From: Jon Smirl
- Re: OpenGL-based framebuffer concepts
- From: Matthew Garrett
- Re: replacing X Window System !
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