Re: [Xenomai-help] Xenomai, Beagleboard and RTAI

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On 11/04/2011 07:15 PM, Lyons, Brendon N wrote:
> I am sorry for the previous message with no subject. I am resending
> this so that it can be properly tagged.
> 
> ______________________________________
> 
> Hello,
> 
> I am currently working on a project which requires realtime use of a
> beagleboard. I know that Xenomai is a realtime kernel however, our
> setup calls for the use of Mathworks' Simulink support for RTAI. I
> have been doing some research and have found that Xenomai
> incorporates RTAI as a skin? I am not entirely sure what that means
> but it sounds like I can simply copy and paste RTAI headers in the
> designated ../rtai folder within Xenomai and have my rtai programs
> compile and run on Xenomai.
> 
> Here is an outline of the goals I would like to achieve:
> 
> 
> *   Have Xenomai running on a beagleboard with an RTAI skin *
> Generate realtime programs with the Simulink support for RTAI *
> Upload the program and run it on the beagleboard
> 
> I have a few questions regarding this approach:
> 
> First of all is this even feasible?

I do not think so. Xenomai RTAI skin was a kernel-only skin, and chances
are that the code generated by simulink is for LXRT, that is, RTAI
user-space support.

However, there exist equivalent solutions to RTAI-lab for Xenomai. We
have seen a post recently about such a solution:
https://mail.gna.org/public/xenomai-core/2011-10/msg00019.html
A user of Xenomai, "Michel He" seems also to have worked on that too.


 Secondly if it is, what would be
> the consequences of running an RTAI executable built on say <ubuntu
> 9.04 kernel 2.6.28.7 with gcc 4.3.3> on <Xenomai 2.5.2 Kernel
> 2.6.28.10 (adeos-ipipe-2.6.28.10-arm-1.12-07) patch  with gcc 4.3.3>
> (this is the closest kernel match I could find)
> 
> Or if I wanted to run a later Xenomai such as <Xenomai 2.5.6 Kernel
> 2.6.33 (adeos-ipipe-2.6.33-arm-1.18-02) patch with gcc 4.3.3>
> 
> Which leads me to my next question, what is the earliest kernel +
> Xenomai combination supported on the beagleboard?

Note that it does not make sense to pick a release in a branch which is
not the latest, for instance, if you pick a release in the 2.5 branch,
it should be the latest, that is 2.5.6, previous adeos patches work with
latest releases anyway.

What is the reason for picking an old version of the Adeos patch? When
starting a new project people usually pick the latest kernel. Anyway,
the oldest version of the Adeos patch supporting omap3 should be 2.6.31.

-- 
                                                                Gilles.