unable to install beta6 [amd64] on Dell 2850 with 4 GB RAM,workaround

Claus Guttesen cguttesen at yahoo.dk
Thu Sep 30 05:09:47 PDT 2004

> The AMR driver cannot handle >4GB of RAM.  Even
> though you only have 
> 4GB, your chipset is remapping part of it to the
> >4GB region.  The 
> driver incorrectly interfaces with busdma and cannot
> handle this
> scenario very well.  The panic is to be expected. 
> You can verify
> this by setting the tunable 'hw.physmem' in the
> loader to some
> value under 4GB to artifically limit the amount of
> RAM that the OS
> sees.

Added hw.physmem=4G to /boot/loader.conf and it seems
to solve the issue. Dmesg now tells me that I have

real memory  = 3489398784 (3327 MB)
avail memory = 3367739392 (3211 MB)

It seems that it does ignore some RAM, but is this the
correct behaviour?

Without hw.physmem I get

real memory  = 5100273664 (4864 MB)
avail memory = 4125847552 (3934 MB)

So it appears to perform an incorrect probing of

Thank you.

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