From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:32875) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WiQQz-0000j9-F0 for qemu-devel@nongnu.org; Thu, 08 May 2014 11:40:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WiQQq-00047e-9s for qemu-devel@nongnu.org; Thu, 08 May 2014 11:40:33 -0400 Message-ID: <536BA54B.3080600@gmail.com> Date: Thu, 08 May 2014 10:39:55 -0500 From: Tom Musta MIME-Version: 1.0 References: <1399537603-6905-1-git-send-email-dougkwan@google.com> <1399537603-6905-4-git-send-email-dougkwan@google.com> <536B978C.80107@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 3/3] configure: Add new target ppc64el-linux-user List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , =?UTF-8?B?IkRvdWcgS3dhbiAo6Zec?= =?UTF-8?B?5oyv5b63KSI=?= Cc: Riku Voipio , "qemu-ppc@nongnu.org" , QEMU Developers , Alexander Graf On 5/8/2014 10:25 AM, Peter Maydell wrote: > On 8 May 2014 16:19, Doug Kwan (關振德) wrote: >> On Thu, May 8, 2014 at 7:41 AM, Tom Musta wrote: >>> We have TCG targets for PowerPC that are bi-endian. It would be much nicer >>> to have to split >>> user mode by endianness. If the user loads a BE ELF, then run in BE mode >>> .... a LE ELF, >>> then run in LE mode. >>> >>> I know there is much hand waving in that statement ... but maybe we can do >>> better? ("we" includes >>> "me" in that statement ... since I offered to Doug to help out with this). > >> To do this, we need to fix the elf load. > > That is far from the only thing that would need changing. > I really don't recommend trying to do something different > from the norm here. > > Isn't LE PPC a different ABI anyway? (ELFv2). > > thanks > -- PMM > It is true that the new LE distros are basing on ELFv2. But ELFv2 ABI is not limited to LE. I chatted with Uli on this very topic and he confirmed that endianness is specified in the e_ident field of the header. I believe we have thoroughly demonstrated that the (softmmu) TCG code works correctly in both settings of MSR[LE], without making compile time decisions. It doesn't seem like we are that far off ... maybe I don't see the problem yet.