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From: Scott Wood <scottwood@freescale.com>
To: Heiko Schocher <hs@denx.de>
Cc: Wolfgang Denk <wd@denx.de>,
	linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [PowerPC] MPC8272ADS: fix device tree for 8 MB flash, size
Date: Thu, 14 May 2009 16:48:19 -0500	[thread overview]
Message-ID: <20090514214819.GA15549@b07421-ec1.am.freescale.net> (raw)
In-Reply-To: <4A0A683B.5010209@denx.de>

On Wed, May 13, 2009 at 08:27:07AM +0200, Heiko Schocher wrote:
> Hello Wolfgang,
> 
> > The current device tree for the MPC8272ADS assumes a mapping of 32 MB
> > of NOR flash at 0xFE00.0000, while there are actually only 8 MB on
> > the boards, mapped at 0xFF80.0000. When booting an uImage with such a
> > device tree, the kernel crashes because 0xFE00.0000 is not mapped.
> 
> Wouldn;t it be better, if u-boot fixes the device tree entries?

We should proabbly leave out the ranges altogether, and have u-boot
populate it from the mappings it establishes.

> I think, u-boot should know, where the flash begins and ends, and
> because this is maybe a dynamic variable for this board, it should
> be better, if u-boot fixes this, so no need for adding a device tree
> for every board variant.

Flash is on a SIMM on this board, and the board manual says it's
expandable to 32 MiB.  However, I suspect that the current DTS was just
an error as I based it on a board that had not had its flash SIMM
modified.  That specific flash SIMM is no longer working (or perhaps just
got its contents corrupted -- one of these days I may hook up a BDI and
try to reflash), so I can't go back and check.

I don't see how current u-boot would accomodate more than 8MiB flash on
this board (there's some detection in board/freescale/mpc8260ads/flash.c,
but I don't see any setting of BR0 besides the preliminary value at
0xff800000).

-Scott

WARNING: multiple messages have this Message-ID (diff)
From: Scott Wood <scottwood@freescale.com>
To: Heiko Schocher <hs@denx.de>
Cc: linuxppc-dev@ozlabs.org, Wolfgang Denk <wd@denx.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [PowerPC] MPC8272ADS: fix device tree for 8 MB flash, size
Date: Thu, 14 May 2009 16:48:19 -0500	[thread overview]
Message-ID: <20090514214819.GA15549@b07421-ec1.am.freescale.net> (raw)
In-Reply-To: <4A0A683B.5010209@denx.de>

On Wed, May 13, 2009 at 08:27:07AM +0200, Heiko Schocher wrote:
> Hello Wolfgang,
> 
> > The current device tree for the MPC8272ADS assumes a mapping of 32 MB
> > of NOR flash at 0xFE00.0000, while there are actually only 8 MB on
> > the boards, mapped at 0xFF80.0000. When booting an uImage with such a
> > device tree, the kernel crashes because 0xFE00.0000 is not mapped.
> 
> Wouldn;t it be better, if u-boot fixes the device tree entries?

We should proabbly leave out the ranges altogether, and have u-boot
populate it from the mappings it establishes.

> I think, u-boot should know, where the flash begins and ends, and
> because this is maybe a dynamic variable for this board, it should
> be better, if u-boot fixes this, so no need for adding a device tree
> for every board variant.

Flash is on a SIMM on this board, and the board manual says it's
expandable to 32 MiB.  However, I suspect that the current DTS was just
an error as I based it on a board that had not had its flash SIMM
modified.  That specific flash SIMM is no longer working (or perhaps just
got its contents corrupted -- one of these days I may hook up a BDI and
try to reflash), so I can't go back and check.

I don't see how current u-boot would accomodate more than 8MiB flash on
this board (there's some detection in board/freescale/mpc8260ads/flash.c,
but I don't see any setting of BR0 besides the preliminary value at
0xff800000).

-Scott

  reply	other threads:[~2009-05-14 21:48 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <mailman.7754.1242158509.26545.linuxppc-dev@ozlabs.org>
2009-05-13  6:27 ` [PATCH] [PowerPC] MPC8272ADS: fix device tree for 8 MB flash, size Heiko Schocher
2009-05-13  6:27   ` Heiko Schocher
2009-05-14 21:48   ` Scott Wood [this message]
2009-05-14 21:48     ` Scott Wood
2009-05-15  5:54     ` Heiko Schocher
2009-05-15  5:54       ` Heiko Schocher
2009-05-15 15:36       ` Scott Wood
2009-05-12 19:06 [PATCH] [PowerPC] MPC8272ADS: fix device tree for 8 MB flash size Wolfgang Denk
2009-05-12 19:06 ` Wolfgang Denk
2009-05-13 10:28 ` Li Yang
2009-05-13 10:28   ` Li Yang
2009-05-13 19:42   ` Wolfgang Denk
2009-05-13 19:42     ` Wolfgang Denk
2009-05-20 13:29     ` Kumar Gala
2009-05-20 13:29       ` Kumar Gala
2009-05-20 14:47       ` Scott Wood
2009-05-20 14:47         ` Scott Wood
2009-06-11  1:51 ` Kumar Gala
2009-06-11  1:51   ` Kumar Gala

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