From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stefan Roese <sr@denx.de>
Date: Thu, 3 Jan 2008 12:12:58 +0100
Subject: [U-Boot-Users] disabling d-cache in 'bootelf' for QNX
In-Reply-To: <477CB941.2020001@semihalf.com>
References: <477BCC7F.4030709@semihalf.com> <200801031116.18392.sr@denx.de>
	<477CB941.2020001@semihalf.com>
Message-ID: <200801031212.58889.sr@denx.de>
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To: u-boot@lists.denx.de

On Thursday 03 January 2008, Rafal Jaworowski wrote:
> >> 1. Does it really hold true that QNX requires d-cache disabled upon
> >> passing control to it?
> >>
> >> 2. If so, this is a custom QNX thing that belongs to do_bootm_qnxelf()
> >> and should be handled there and not at the common ELF handling level.
> >
> > Hmmm. I think that calling applications and especially OS'es is more safe
> > with caches disabled then with caches enabled.
>
> Yeah, after a second thought I tend to agree. Maybe the way to go is doing
> data cache flush from within dcache_disable() properly i.e. bring it in for
> arch variations that don't do it currently like 85xx... Actually to confirm
> my observations I tested a working patch that flushes d-cache at
> cache_disable() just like 86xx and it works for me, this is: my problems
> disappear. Do you think this is a better option?

Yes, I think this is the way to go. Please provide a patch and send it to the 
85xx maintainer. Best would be if you could check the other ARCH's (at least 
PPC) for this dcache_disable() behaviour too.

Thanks.

Best regards,
Stefan

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