From mboxrd@z Thu Jan  1 00:00:00 1970
From: Rafal Jaworowski <raj@semihalf.com>
Date: Wed, 02 Jan 2008 18:40:15 +0100
Subject: [U-Boot-Users] disabling d-cache in 'bootelf' for QNX
Message-ID: <477BCC7F.4030709@semihalf.com>
List-Id: <u-boot.lists.denx.de>
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To: u-boot@lists.denx.de

Hi,

Currently do_bootelf() disables data cache just before passing control to the
entry point:

        /*
         * QNX images require the data cache is disabled.
         * Data cache is already flushed, so just turn it off.
         */
        if (dcache_status ())
                dcache_disable ();

With this piece of code present I'm seeing strange effects (corrupt data
access, hangs) in standalone apps running from the ELF envelope. A pure binary
made of this same ELF works without problems. Contrary to the comment above,
there's no quarantee in do_bootelf() code flow that all data cache has been
flushed and it seems there needs to be flush_data_cache() executed before the
disable.

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.

Any objections to pushing this down to do_bootm_qnxelf()? I can provide a
patch, but cannot test it with any QNX system. Is there anyone with such setup
that would give this a try?

Rafal