From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <511944AC.6060800@xenomai.org> Date: Mon, 11 Feb 2013 20:21:16 +0100 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <718DFA7882181D45B8BD18F31C46D55427A67586@MBX204.domain.local> <718DFA7882181D45B8BD18F31C46D55427A675C0@MBX204.domain.local>, <718DFA7882181D45B8BD18F31C46D55427A67767@MBX204.domain.local> In-Reply-To: <718DFA7882181D45B8BD18F31C46D55427A67767@MBX204.domain.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Question about 2.6.2.1 List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gregory Perry Cc: Michael Haberler , "xenomai@xenomai.org" On 02/11/2013 06:50 PM, Gregory Perry wrote: >> ________________________________________ From: Michael Haberler >> [mah@mah.priv.at] Sent: Monday, February 11, 2013 6:06 AM To: >> Gregory Perry Subject: Re: [Xenomai] Question about 2.6.2.1 >> >> Am 11.02.2013 um 06:23 schrieb Gregory Perry: >> >>> How do I go about finding out what the most recent kernel for ARM >>> that is supported by 2.6.2.1? Is it still 3.2.21? Can someone >>> point me to the file in the Xenomai >distro which describes the >>> most recent kernel released with each Xenomai? >>> >>> I am going to take the plunge and patch each release up to 3.2.21 >>> on the BeagleBone with the TI support patches, and then attempt a >>> Xenomai integration on that >optimized TI kernel. >> >> are you aware of this: >> >> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?BeagleboneDevsetup >> >> and this >> >> http://git.mah.priv.at/gitweb?p=linuxcnc-kernel.git;a=summary ? >> >> - Michael > > Yeah I've been following the EMC project for a while now as well as > other initiatives to build Xenomai on the BeagleBone and BeagleBoard. > In fact I think that Stephan Kappertz has posted the best integration > to date for the BeagleBone and Xenomai on Angstrom; however I am not > aware of anyone to date that's been able to successfully integrate > all of the TI patches into the kernel and then patch the kernel with > Xenomai. So either you get the BeagleBone kernel with all all TI > optimizations, or a generic kernel with Xenomai support, but not > both. Typically this breaks support for additional things in the > kernel, probably sysfs support for sysfs-based GPIO access and PWM > toggling etc. sysfs-base GPIO access and PWM is a bad example, as except for powering on/off things once in a while, you do not really want the overhead of a system call for toggling a GPIO, besides the fact that it would cause a real-time task to cease being a real-time task. > > So according to Robert Nelson (the TI patch maintainer for the > BeagleBoard/Bone kernel), the only way to do this is to start with > the Aragon kernel, apply each kernel revision patch from 3.2.0 -> > 3.2.21, with the TI patch branch applied at each to arrive at a > 3.2.21 kernel that has all of the TI patches integrated. > > I think this is the right approach, or maybe I am just shooting fish > in a barrel here with this. The right approach is to get the code from the TI branch merged into the mainline kernel. Failing that, provide a pre and post patches (like Michael provided) for the target kernel, patches which we can ship with Xenomai. Merging the I-pipe with a vendor kernel should not be a really hard job, you should only get conflicts between the processor-specific files modified by the I-pipe kernel, which should be say, less than 10 files. -- Gilles.