amd64 5.3rc1 panic during install on 8GB RAM Tyan S2885 w/ twe disk

[James R. Van Artsalen]

David O'Brien wrote:

>On Sun, Oct 31, 2004 at 04:33:28PM -0600, James R. Van Artsalen wrote:
>  
>
>>My Tyan S2885 K8W repeatedly panics during the file copy with CD install 
>>of 5.3rc1.
>>    
>>
>..
>  
>
>>This hardware configuration worked well under 5.2.1 for a couple of 
>>months.  I've reinstalled 5.2.1 and it still works fine there.
>>    
>>
>
>Can you try the 5.3 Beta's to see when this broke for you?
> 
>  
>
I can't find any older 5.3 beta ISO's to test.

If I say "set hw.physmem=3g" in the loader before booting then 5.3rc1 
works fine and seems stable.

Otherwise, my 8GB RAM system won't finish an install.  The twe driver 
uses bounce buffers to reach memory above 4GB.

There have been changes to twe since 5.2.1 but nothing that looks major 
to me.  However, there apparently have been changes to the amd64 
busdma_machdep.c. Since ATA is rumored to be unreliable with more than 
4GB could this be a general bounce-buffer problem?  I can't follow the 
code there.