On Mon, Dec 10, 2001 at 05:33:09PM -0800, Philip Brown wrote: > On Mon, Dec 10, 2001 at 08:52:26PM +0100, Benjamin Herrenschmidt wrote: > > ... > > Some chipsets (and the original agpgart supported those only) can > > let the CPU access the AGP aperture directly. All mmap had to do > > was then to map the user pages to the aperture physical pages, > > if they had memory bound or not didn't matter. > > waitamint... I just read > http://developer.intel.com/design/intarch/techinfo/440BX/addrmap.htm > > which describes the AGP Graphics Aperture, as the > "AGP Dram Graphics Aperture". > > Which means 'A way for the AGP device to access main RAM'. > All this time I thought it was a way for programs to access the RAM > on-board the card! > Well that clears things up a bit :-/ > > But... isnt there a straightforward mmap type way to access the RAM on > board the card, then? > Or is it usually "load the data to the aperture, then copy it > into card-local RAM from there" ? > [or via the "drmDMA" stuff, I suppose?]
Why do you want to touch the framebuffer (video memory, that is)? That's one way to make your 3D graphics go really slowly... AGP was designed to let the graphics processor pull data from system memory, instead of having the CPU push data out. -- Gareth _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
