[LinuxBIOS] problem about dram init

joe at smittys.pointclark.net joe at smittys.pointclark.net
Fri Dec 21 10:34:51 CET 2007


Quoting Corey Osgood <corey.osgood at gmail.com>:

> aaron lwe wrote:
>> Dear All,
>>
>> I'm terribly sorry that I just found I've mistakenly configured the
>> dram MA Map Type, and now memtest
>> showed no errors. But I still have to reduce the mem size when
>> reporting to system through ram_resource
>> or filo couldn't be started.  I have disabled the integrated graphics
>> card and the agp, so I don't think the top
>> memory should be reserved for frame buffer.
>
> 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
>
Hmm. I think this also is true with some Intel chipsets. Even without  
graphics enabled there has to be some kind of reserved memory space  
just below tolm (the smallest I was sucessfull with was 1MB) or filo  
chokes. Doesn't LB allocate a bounce buffer just before the payload  
starts? Is this bounce buffer just below tolm??


Thanks - Joe




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