From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.windriver.com ([147.11.1.11]) by linuxtogo.org with esmtp (Exim 4.72) (envelope-from ) id 1PmWxE-0006Yz-1o for openembedded-devel@lists.openembedded.org; Mon, 07 Feb 2011 20:40:56 +0100 Received: from ALA-MAIL03.corp.ad.wrs.com (ala-mail03 [147.11.57.144]) by mail.windriver.com (8.14.3/8.14.3) with ESMTP id p17JdiVM023410; Mon, 7 Feb 2011 11:39:44 -0800 (PST) Received: from ala-mail06.corp.ad.wrs.com ([147.11.57.147]) by ALA-MAIL03.corp.ad.wrs.com with Microsoft SMTPSVC(6.0.3790.1830); Mon, 7 Feb 2011 11:39:43 -0800 Received: from Macintosh-5.local ([172.25.36.226]) by ala-mail06.corp.ad.wrs.com with Microsoft SMTPSVC(6.0.3790.1830); Mon, 7 Feb 2011 11:39:43 -0800 Message-ID: <4D504A7E.4030809@windriver.com> Date: Mon, 07 Feb 2011 13:39:42 -0600 From: Mark Hatle Organization: Wind River Systems User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7 MIME-Version: 1.0 To: openembedded-devel@lists.openembedded.org References: <1297093986-24331-1-git-send-email-enrico.scholz@sigma-chemnitz.de> In-Reply-To: X-OriginalArrivalTime: 07 Feb 2011 19:39:43.0850 (UTC) FILETIME=[C4F3DCA0:01CBC6FE] Cc: Enrico Scholz Subject: Re: [PATCH] cortex-m3: adjusted target cflags X-BeenThere: openembedded-devel@lists.openembedded.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: openembedded-devel@lists.openembedded.org List-Id: Using the OpenEmbedded metadata to build Distributions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Feb 2011 19:40:56 -0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/7/11 1:33 PM, Khem Raj wrote: > On Mon, Feb 7, 2011 at 7:53 AM, Enrico Scholz > wrote: >> Explicit '-mthumb' is required because Cortex-M3 does not support ARM >> instructions and actual flags cause gcc to fail with 'error: target CPU >> does not support ARM mode'. >> >> The '-mcpu=cortex-m3' is shorter than '-march=armv7-m -mtune=cortex-m3' >> and enables workarounds like '-mfix-cortex-m3-ldrd'. > > Does -mcpu=cortex-m3 also cause gcc to tune for cortex-m3 ? -mcpu=cortex-m3 is equivalent to -march=cortex-m3 -mtune=cortex-m3 So in this instance, it will have a side effect of potentially changing the available set of instructions.. The existing command says the only available instructions are those defined as "armv7-m", but I want to tune the instruction scheduler for execution on "cortex-m3". (I'm not an ARM expert, so I'm not sure what is reasonable in this case.. but the arguments do have slightly different meanings.) --Mark >> >> Signed-off-by: Enrico Scholz >> --- >> conf/machine/include/tune-cortexm3.inc | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/conf/machine/include/tune-cortexm3.inc b/conf/machine/include/tune-cortexm3.inc >> index 6da9aee..a66a33c 100644 >> --- a/conf/machine/include/tune-cortexm3.inc >> +++ b/conf/machine/include/tune-cortexm3.inc >> @@ -1,4 +1,4 @@ >> # valid options for -march: `armv7', `armv7-m' >> -TARGET_CC_ARCH = "-march=armv7-m -mtune=cortex-m3 -mfpu=vfp -mfloat-abi=softfp" >> +TARGET_CC_ARCH = "-mthumb -mcpu=cortex-m3 -mfpu=vfp -mfloat-abi=softfp" >> FEED_ARCH = "armv7" >> BASE_PACKAGE_ARCH = "armv7" >> -- >> 1.7.4 >> >> >> _______________________________________________ >> Openembedded-devel mailing list >> Openembedded-devel@lists.openembedded.org >> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel >> > > _______________________________________________ > Openembedded-devel mailing list > Openembedded-devel@lists.openembedded.org > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel