From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Subject: Re: [PATCH 5/5] arm: dts: Convert mvebu device tree files to 64
 bits
Date: Thu, 21 Mar 2013 22:08:10 +0100
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To: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>, Jason Cooper <jason@lakedaemon.net>, Grant Likely <grant.likely@secretlab.ca>, Rob Herring <rob.herring@calxeda.com>, Ezequiel Garcia <ezequiel.garcia@free-electrons.com>, linux-arm-kernel@lists.infradead.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>, Olof Johansson <olof@lixom.net>, Nicolas Pitre <nico@fluxnic.net>, Lior Amsalem <alior@marvell.com>, Maen Suleiman <maen@marvell.com>, Tawfik Bayouk <tawfik@marvell.com>, Shadi Ammouri <shadi@marvell.com>, Eran Ben-Avi <benavi@marvell.com>, Yehuda Yitschak <yehuday@marvell.com>, Nadav Haklai <nadavh@marvell.com>, Ike Pan <ike.pan@canonical.com>, Chris Van Hoof <vanhoof@canonical.com>, Dan Frazier <dann.frazier@canonical.com>, Leif Lindholm <leif.lindholm@arm.com>, Jon Masters <jcm@redhat.com>
List-Id: devicetree@vger.kernel.org

Dear Andrew Lunn,

On Thu, 21 Mar 2013 21:37:51 +0100, Andrew Lunn wrote:

> > And I'm not sure the SDRAM address decoding windows allows to split the
> > first 4 GB of RAM into two areas, one that would be mapped starting at
> > physical address 0x0, and another area that would be mapped at a
> > different address (above 4 GB).
> 
> So why not map the whole SDRAM above 4GB physical address?

That's a good question. The problem is most likely that this would
require to synchronize with U-Boot modifications, which is not easy to
achieve.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com