From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:45543)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1aTRmm-0004EF-6f
	for qemu-devel@nongnu.org; Wed, 10 Feb 2016 05:14:13 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1aTRmg-0006VM-Js
	for qemu-devel@nongnu.org; Wed, 10 Feb 2016 05:14:12 -0500
Received: from mail-vk0-x230.google.com ([2607:f8b0:400c:c05::230]:33672)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1aTRmg-0006VI-F6
	for qemu-devel@nongnu.org; Wed, 10 Feb 2016 05:14:06 -0500
Received: by mail-vk0-x230.google.com with SMTP id k196so9915246vka.0
	for <qemu-devel@nongnu.org>; Wed, 10 Feb 2016 02:14:06 -0800 (PST)
MIME-Version: 1.0
In-Reply-To: <CACga1gmgk87k77WDcb5KawvqR2gpCmtJTVL73q2m0JaJEYVqPw@mail.gmail.com>
References: <CACga1gnbjqsoRkJCSDQnd_=fgvmjS_05ViYN_kK2soAynP2Kgw@mail.gmail.com>
	<CACga1gmqTS89gw_RT-A754TQ2z5-Ps1-71-G1qtghAavtTa7rg@mail.gmail.com>
	<CAFEAcA9xjmU_Exep6uTxq_8gq9hffPO5vdMj5kTEL9DTbmjD+Q@mail.gmail.com>
	<CACga1gkZJ5FwHCEfObWXmGXmVOAkGuBQEZ-vAJ+HBDycBV3xaw@mail.gmail.com>
	<CAFEAcA_VLZ21gvG2CdCKFWO-+xs7SQdLkm+YRbHf11c+S5u79Q@mail.gmail.com>
	<CACga1gm6Tr5=tSKMGOYhXWKan05UBP3=2s3jLSNXXAYX1vD7pQ@mail.gmail.com>
	<CAFEAcA_ZOYbeMsC3R7Y=shGoEtMxnRsCrY9nQdqEfLHaU03X=w@mail.gmail.com>
	<CACga1gmgk87k77WDcb5KawvqR2gpCmtJTVL73q2m0JaJEYVqPw@mail.gmail.com>
From: Peter Maydell <peter.maydell@linaro.org>
Date: Wed, 10 Feb 2016 10:13:46 +0000
Message-ID: <CAFEAcA-UhDUXhj1gZbZo3s1rLThM17WrniwGJMShJ_E6icfuzQ@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [Qemu-devel] Regarding Cortex-A7 CPU definition
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Deepak kumar Raju <raju.deepakkumar@gmail.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>

On 10 February 2016 at 05:25, Deepak kumar Raju
<raju.deepakkumar@gmail.com> wrote:
> Regarding the questions, we have hw board which has Cortex-A7, so we thought
> we have to go with A7 emulation. we were not very sure A15 emulation will be
> almost equivalent to A7 emulation.
> All we want to do is A7 emulation but now I am understanding that A15
> emulation should similar to A7 emulation. please correct me.

If you want to emulate the whole hardware board in QEMU,
then adding the A7 CPU emulation is the right thing (and
not very hard compared to doing the whole hardware model).
If you don't care about emulating the hardware because you're
going to run (say) a Linux kernel on one of QEMU's existing
models and you mostly care about userspace, then using the
A15 will be fine -- the two CPUs are basically identical
for that purpose, and Linux supports both.

If you're running QEMU to use KVM on the ARM hardware,
then you want "-cpu host", which means "use the best CPU
type that the kernel can provide" and works on A7 and A15
hosts.

thanks
-- PMM