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From: "Dale Farnsworth" <dale@farnsworth.org>
Date: Wed, 3 Oct 2007 12:51:25 -0700
To: Rune Torgersen <runet@innovsys.com>
Subject: Re: [PATCH] PPC 85xx failure with odd memory sizes and CONFIG_HIGHMEM
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On Wed, Oct 03, 2007 at 02:34:42PM -0500, Rune Torgersen wrote:
> > From: Dale Farnsworth
> > 
> > The CONFIG_FSL_BOOKE mmu setup code fails when CONFIG_HIGHMEM=y
> > and the 3 fixed TLB entries cannot exactly map the lowmem size.
> > Each TLB entry can map 4MB, 16MB, 64MB or 256MB, so the failure
> > is observed when the kernel lowmem size is not equal to the
> > sum of up to 3 of those values.
> 
> Does this mean you cannot run 1G of lowmem on a 85xx?

I think you can, and maybe I should have added 1GB to my list of
sizes above.  But, my 85xx system only has 256MB, so I can't test
it.

-Dale