[LinuxBIOS] problem about dram init

Corey Osgood corey.osgood at gmail.com
Wed Jan 2 09:16:46 CET 2008

aaron lwe wrote:
> On Dec 21, 2007 1:40 PM, Corey Osgood <corey.osgood at gmail.com> wrote:
>> And now you're where I am. For some reason there's a reserved memory
>> range _somewhere_ at the tolm, of some unknown size. I've found that
>> reserving an extra 1MB doesn't work, but 32MB does. I've found nothing
>> in the documentation I have to explain this. BTW, have you had to make
>> any code changes other than the MA Map, and board-specific fixes? I'm
>> wondering how generic that code really is.
>> -Corey
> Corey, I think I've found the cause of this problem, it's agp aperture memory
> that caused this memory unusable. When I set agp aperture memory
> size to 128MB, I found I could only use the tolm - 128 * 1024 memory,
> and you set agp aperture memory size to 32MB, so reserving 32MB
> worked for you. The smallest size I can set for agp apertur memory size
> is 4MB and after setting that, memtest now reports 508MB(512MB - 4MB)
> is working fine ;-)
> Only I don't know why agp aperture memory would interfere with physical memory.

Are you configuring the system for AGP 2.0 or 3.0, ie are you
configuring dev 0.0 or 1.0? The way I had it set up, I thought, was 32MB
for video, 32MB for agp, and the rest for the system, using AGP 3.0. I
could very well have messed something up somewhere, though.


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