From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philippe Gerum In-Reply-To: <4C3EF6D6.6040907@domain.hid> References: <1278943817.7023.18.camel@domain.hid> <4C3EF6D6.6040907@domain.hid> Content-Type: text/plain; charset="UTF-8" Date: Thu, 15 Jul 2010 18:11:38 +0200 Message-ID: <1279210298.1995.38.camel@domain.hid> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Marvell sheeva support List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Tim Cussins Cc: xenomai@xenomai.org On Thu, 2010-07-15 at 13:53 +0200, Gilles Chanteperdrix wrote: > Tim Cussins wrote: > > Hi all, > > > > We're looking at migrating to one of Marvell's MV88F series SOC's, and > > are very keen to deploy Xenomai as part of our solution. > > > > I noticed Sergey Didenko was looking at this a few months back and > > things looked to be ok - has his (or anyone else's) work made it into a > > stable release? > > > > I will be able to assist in about a fortnight if that would be useful > > for squaring that work away. > > > > Let me know if I can help! > > We are interested. I seem to remember that Serguey had unexplained > latencies issues, so, if you start with his work, please bear this in > mind, there was probably something wrong with his port. A guide > explaining how to port the I-pipe patch on ARM exists: > http://www.xenomai.org/index.php/I-pipe:ArmPorting > > The section about chained GPIOs irqs is outdated, if your platform has > some, I will explain how it should be implemented. > > Please start from the I-pipe git (git://git.denx.de/ipipe-2.6.git), > merging it with the branch you will use if needed, so that you can > submit a patch only containing the modifications necessary for the > Sheeva platform. > > We can also provide you with a root filesystem for validating this platform. > You can also use the patch below as a starting point for your port: http://download.gna.org/adeos/patches/tmp/adeos-ipipe-2.6.29-mv88f6290.patch caveats: - it is based on an old kernel release, and moving to 2.6.3x would require some work. If you need so, then you should merge the arm-dependent bits from the patch above with the generic I-pipe bits from a newer release as available here (e.g. 2.6.33): http://download.gna.org/adeos/patches/v2.6/arm/ - the fcse implementation in that patch won't work with the l2 outer cache enabled. The two options have been made mutually exclusive via Kconfig. - you should use Xenomai 2.5.3 or above to get this running. As a reference point, the worst-case scheduling latency for user-space threads, observed on a mv88f6290 using that patch with fcse enabled (no l2), is below 70 us. HTH, -- Philippe.