x86_64 - 4 Gig DRAM 500Meg missing

Dave Jones davej at redhat.com
Fri Jun 24 20:27:58 UTC 2005


On Fri, Jun 24, 2005 at 12:43:29PM -0700, Wolfgang S. Rupprecht wrote:
 > 
 > I'm trying to understand what I need to do to make the last 500Meg of
 > my 4GB memory visible on a FC4 x86_64.  I assume that the 3.5GB - 4GB
 > area is being used for hardware and I need to arrange for the memory
 > to be mapped elsewhere.

Correct, you'll need some space in the lower 4GB for PCI to mapped.

 > My motherboard, a tyan k8e (s2865) has entries in the bios for
 > something called:
 > 
 >           S/W memory hole Remapping     disable / enable
 >           H/W memory hole Remapping     disable / enable
 >           MTRR mapping mode             continuous / discrete
 >  
 > It looked like one or both of the first two entries would do the
 > trick, but when I enabled them all that happened was my add-in network
 > card stopped working.  At boot dhcp was unable to get an address and
 > booting hung at that point.  This happened s/w or h/w remapping was
 > active (either singly or together.

Hmm, usually such an option does the trick.  Is there a newer BIOS
you can try perhaps ? It's not really a problem that we can do anything
about sadly.

		Dave




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