From mboxrd@z Thu Jan  1 00:00:00 1970
From: jason@lakedaemon.net (Jason Cooper)
Date: Wed, 22 May 2013 13:13:59 -0400
Subject: [PATCH 0/9] Switch internal registers address to 0xF1 on
 Armada 370/XP
In-Reply-To: <20130522185757.60091a66@skate>
References: <1369132414-18959-1-git-send-email-thomas.petazzoni@free-electrons.com>
 <201305221633.46705.arnd@arndb.de> <20130522170643.54a2b9d2@skate>
 <201305221735.11815.arnd@arndb.de> <20130522180842.7edcc3ee@skate>
 <20130522163557.GC27348@1wt.eu> <20130522184250.1d5f2f10@skate>
 <20130522164936.GE31290@titan.lakedaemon.net>
 <20130522185757.60091a66@skate>
Message-ID: <20130522171359.GG31290@titan.lakedaemon.net>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wed, May 22, 2013 at 06:57:57PM +0200, Thomas Petazzoni wrote:
> Dear Jason Cooper,
> 
> On Wed, 22 May 2013 12:49:36 -0400, Jason Cooper wrote:
> 
> > > As far as I know, a DT-capable bootloader doesn't pass any ATAG. The
> > > ARM register that was used to pass the pointer to the ATAGS is now used
> > > to pass the pointer to the DTB in memory.
> > 
> > So we could look for the ATAG magic or the dtb magic at that address,
> > then we know if we have an old or new bootloader...
> 
> No, because you can use an old bootloader, and still do some old-style

Did you mean 'new bootloader'?

> appended-DTB booting, in which case you have a new bootloader
> (registers mapped at 0xf1), but you see the ATAG magic, which will make
> you think you booted from an old bootloader (registers mapped at 0xd0).
> 
> For example, I'm currently booting alternatively with an old and a new
> bootloader (to test that things work properly), and in both cases I'm
> booting old style, DTB-appended, with ATAGs.

Is this something users would experience?  I think it is fairly safe to
say that once dt-able bootloaders are shipped, they will provide a dtb.
So, OF_DT_MAGIC == new bootloader might hold true for users.

thx,

Jason.