From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1KpMht-00047c-NX
	for qemu-devel@nongnu.org; Mon, 13 Oct 2008 08:39:29 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1KpMhs-00045E-9M
	for qemu-devel@nongnu.org; Mon, 13 Oct 2008 08:39:29 -0400
Received: from [199.232.76.173] (port=46591 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1KpMhs-000457-6H
	for qemu-devel@nongnu.org; Mon, 13 Oct 2008 08:39:28 -0400
Received: from mail.codesourcery.com ([65.74.133.4]:52497)
	by monty-python.gnu.org with esmtps
	(TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60)
	(envelope-from <paul@codesourcery.com>) id 1KpMhr-0002Kp-Kj
	for qemu-devel@nongnu.org; Mon, 13 Oct 2008 08:39:27 -0400
From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH] ARM CP14 trivial support
Date: Mon, 13 Oct 2008 13:39:23 +0100
References: <1223894552.30000.30.camel@petitemort>
In-Reply-To: <1223894552.30000.30.camel@petitemort>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200810131339.24217.paul@codesourcery.com>
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org, dsilvers@simtec.co.uk

On Monday 13 October 2008, Daniel Silverstone wrote:
> Hi,
>
> Continuing the patch series aiming at supporting Simtec's development
> boards and other Samsung SoC based systems, attached is a patch which
> provides trivial coprocessor 14 support.

I dislike code that blindly ignores everything. Functions should be explicitly 
not implemented (with comments saying exactly what we're not implementing), 
or fail loudly when used. 

The cp14 interface is also used for other debug monitor hardware (breakpoints, 
watchpoints, etc.) and possibly Jazelle DBX. Ignoring those commands is bad.  
IIRC cp14 interfaces are device specific (at least before ARMv6), so you need 
to figure out which cores your hacks apply to. There are definitely several 
different DDC interfaces.

Paul