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RE: smp8634 add memory at dram1

To: "David Daney" <ddaney@avtrex.com>
Subject: RE: smp8634 add memory at dram1
From: "James Zipperer" <jamesz@modsystems.com>
Date: Mon, 3 Mar 2008 17:59:11 -0800
Cc: <linux-mips@linux-mips.org>
In-reply-to: <47CC974F.3090306@avtrex.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
Thread-index: Ach9jncajtrbM7+KS8auCZEQx2hQEQABxn5w
Thread-topic: smp8634 add memory at dram1
> James Zipperer wrote:
>
>> 
>>  
>> 
>> I'm running out of memory in linux on the smp86xx and attempting to 
>> implement this solution.  Did you ever get it to work?  No luck for
me 
>> yet.  I'm still a bit unclear why you must switch linux to run off
DRAM 
>> 1 instead of leaving it on DRAM 0 and adding an additional call to 
>> add_memory_region in prom_init for DRAM 1.  But then again, I haven't

>> gotten that to work yet either :)
>> 
>>  
>> 
>> Any info/patches are greatly appreciated.  Thanks!
>> 
>>  
>> 
>
>Typically DRAM 1 must be accessed through the TLB as its address lays 
>outside of the 512MB window of KSEG[012].
>
>The best way to make this memory available to Linux may still be up for

>debate.
>
>David Daney


I'm sure this is a dumb question due to the fact that my grasp of the
problem is less than acceptable...  

Can remapped addresses (namely CPU_remap[34]_addr) be used for the call
to add_memory_region()?  That would allow the address for DRAM 1 to be
within the 512MB window of KSEG[012].  I'm unclear whether the CPU_remap
addresses count as PHSYICAL or VIRTUAL addresses.  

I'm guessing that my plan won't work since I tried it and it didn't
work.  My results were that the kernel booted but didn't report any
additional memory available via the 'free' command.

Thanks.

-James


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