From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 29 Oct 2009 06:27:22 +0100 (CET) Received: from mail-px0-f188.google.com ([209.85.216.188]:39124 "EHLO mail-px0-f188.google.com" rhost-flags-OK-OK-OK-OK) by ftp.linux-mips.org with ESMTP id S1491846AbZJ2F1P (ORCPT ); Thu, 29 Oct 2009 06:27:15 +0100 Received: by pxi26 with SMTP id 26so1062263pxi.22 for ; Wed, 28 Oct 2009 22:27:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:subject:from:reply-to:to:cc :in-reply-to:references:content-type:organization:date:message-id :mime-version:x-mailer:content-transfer-encoding; bh=3EQlFBhYeN0s0qv05srbDXZDFH/jqSRCUTRBOoUGiso=; b=a5vPk310JAXe6TE/MM7DkGjaM67K8xQsoAaBF9u+gKq5i3fcUsht3GpyzmHZqDi6Xq neebEp7gRHSLyhvKu90entwqAlDrLZIAV8+mK51zM+m55t++JBd/4IIQzwOizzW1ckW/ No5FfULICDHEhNZcElOFwRc2luZNFfzprrnXk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:reply-to:to:cc:in-reply-to:references:content-type :organization:date:message-id:mime-version:x-mailer :content-transfer-encoding; b=XnxYqKkQbNGlIr3lf8LSg+lBxuGaM2+dq9yidkZGh4+mXCHE2mbYxqM7T5IoXM4N1I l4YqY1M01sIl8zSYACInoKU6FcBShwg7u/mQ9PC+8yQDSNE3gAFF1v1vLHyutKUKVCGA wNc1ccnZ5+czcVphMeHl06HoI0znvHC8WfnB4= Received: by 10.114.253.14 with SMTP id a14mr5119349wai.160.1256794028644; Wed, 28 Oct 2009 22:27:08 -0700 (PDT) Received: from ?172.16.2.101? ([222.92.8.142]) by mx.google.com with ESMTPS id 23sm168316pzk.4.2009.10.28.22.27.02 (version=TLSv1/SSLv3 cipher=RC4-MD5); Wed, 28 Oct 2009 22:27:07 -0700 (PDT) Subject: Re: [PATCH -sfr.git] MIPS: zboot: indent the nop instruction in delay slot From: Wu Zhangjin Reply-To: wuzhangjin@gmail.com To: "Maciej W. Rozycki" Cc: Ralf Baechle , Linux-MIPS , Robert Richter , chenj@lemote.com In-Reply-To: References: <1256782252-2240-1-git-send-email-wuzhangjin@gmail.com> Content-Type: text/plain Organization: DSLab, Lanzhou University, China Date: Thu, 29 Oct 2009 13:26:57 +0800 Message-Id: <1256794017.6448.22.camel@falcon> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 24572 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: wuzhangjin@gmail.com Precedence: bulk X-list: linux-mips Hi, On Thu, 2009-10-29 at 03:12 +0000, Maciej W. Rozycki wrote: > On Thu, 29 Oct 2009, Wu Zhangjin wrote: > > > diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S > > index e23f25e..29080f4 100644 > > --- a/arch/mips/boot/compressed/head.S > > +++ b/arch/mips/boot/compressed/head.S > > @@ -38,7 +38,7 @@ start: > > PTR_LA ra, 2f > > PTR_LA k0, decompress_kernel > > jr k0 > > - nop > > + nop > > 2: > > move a0, s0 > > move a1, s1 > > @@ -46,7 +46,7 @@ start: > > move a3, s3 > > PTR_LI k0, KERNEL_ENTRY > > jr k0 > > - nop > > + nop > > 3: > > b 3b need to add one nop here. > > END(start) > > This piece of code looks unsafe to me. I'm not sure which tree this is > against and certainly I don't have a local copy of the file, This is against the of mips-for-linux-next branh of Ralf's http://www.linux-mips.org/git?p=upstream-sfr.git;a=summary > but based on > the manual delay slot scheduling this is built with .set noreorder in > effect Yes, there is exactly a ".set noreorder" there: arch/mips/boot/compressed/head.S: [...] 17 18 .set noreorder 19 .cprestore 20 LEAF(start) 21 start: 22 /* Save boot rom start args */ 23 move s0, a0 24 move s1, a1 25 move s2, a2 26 move s3, a3 27 28 /* Clear BSS */ [...] > and as such the function lacks a delay slot fill for the trailing > branch (which is also ill-formatted). A new version will be sent out, thanks! Regards, Wu Zhangjin