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Subject: Re: [PATCH 1/2] powerpc: add 16K/64K pages support for the 44x
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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Josh Boyer <jwboyer@linux.vnet.ibm.com>
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Date: Mon, 03 Nov 2008 08:33:16 +1100
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Cc: Wolfgang Denk <wd@denx.de>, Ilya Yanok <yanok@emcraft.com>,
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On Sun, 2008-11-02 at 08:41 -0500, Josh Boyer wrote:
> On Sun, Nov 02, 2008 at 08:55:02AM +1100, Benjamin Herrenschmidt wrote:
> >On Sat, 2008-11-01 at 07:30 -0400, Josh Boyer wrote:
> >> 
> >> That is on purpose.  The chip has an errata that causes badness if
> >> you use the last XX bytes of DRAM.  I forget exactly what XX is, but
> >> we just remove the last page.
> >
> >Doing that from the device-tree is very hairy tho... you end up with
> >informations in there that aren't aligned etc... oh well.
> 
> What?  -ENOTVERBOSEENOUGH.
> 
> I don't see how this is really different from U-Boot just passing in
> a smaller memory size in the old arch/ppc world.  (And I think U-Boot
> will actually fixup the device tree in a similar manner itself these
> days.)  So if there are problems with this, please do tell.

Is it cropping the memory nodes or using the reserve map ?

Ben.