On Tue, Jan 14, 2003 at 11:51:53PM -0500, David Dawes scrawled:
> On Tue, Jan 14, 2003 at 09:51:13AM -0800, Tim Roberts wrote:
> >On Tue, 14 Jan 2003 07:51:10 -0500 (EST), Vladimir Dergachev wrote:
> >>
> >>One thing I don't understand about this is that this is an integrated
> >>graphics chipset, right ? I.e. it uses part of system RAM for video RAM.
> >>There is no code in radeon driver to deal with this yet.
> >
> >And there doesn't need to be.  The allocation of video RAM from system RAM is 
> >done by the BIOS very early in boot time.  The physical address of the video 
> >RAM gets stuffed into the PCI BAR register.  The driver doesn't know or care 
> >whether that address is physically on an AGP bus, or in system RAM.
> >
> >The Savage driver is an example.  The Savage/IX uses shared memory, whereas the 
> >Savage/MX has its own separate VRAM.  The driver doesn't care at all.
> 
> I guess the Intel integrated graphics chips (810/815, 830M, 845G) are
> a little different then, with the agpgart kernel driver allowing additional
> system memory to be mapped into the video address space at runtime.

There's also a BIOS option to do this early ...

-- 
Daniel Stone                                     <[EMAIL PROTECTED]>
Developer, Trinity College, University of Melbourne

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