Re: [Embeddedxen-devel] [Xenomai-help] Running Xenomai in a virtual machine

[ROSSIER D. <Dan...@he...>]

> -----Original Message-----
> From: Jan Kiszka [mailto:jan...@si...]
> Sent: lundi, 22. juin 2009 15:55
> To: ROSSIER Daniel
> Cc: Johan Visser; xen...@gn...
> Subject: Re: [Xenomai-help] Running Xenomai in a virtual machine
> 
> ROSSIER Daniel wrote:
> > Just going through this interesting thread, I though it might be of
> interest - probably not fully related to the topic, but... - to know
> > that we are currently working on some integration efforts of Xenomai
> on top of the XEN hypervisor in the context of the
> > embeddedXEN project. For the time being, it is purely devoted to ARM-
> based processors.
> >
> > In case of interest, please visit:
> https://sourceforge.net/projects/embeddedxen. Xenomai will appear as a
> natural subtree of embeddedXEN, like xen or minios,
> > but currently it is not present yet. The hypervisor and miniOS boots
> up in Mainstone/QEMU and soon on a Colibri/PXA270 board. EmbeddedXEN is
> mainly devoted to integrate multiple kernels into a single binary image
> for embedded systems with the support of hard realtime (domainU-RT, a
> new kind of Xen domain).
> 
> Interesting, will have a look (again). Last time I checked was two
> years
> ago when MontaVista (IIRC) announced it. Does/will this version Xen not
> suffer from the RT problems Xen upstream has, e.g. lacking
> preemptibility?

Indeed, it is a major point we want to investigate; we will assess the overhead bound 
to the upcall model of XEN. It is too early to make some predictions

> 
> And what will be the impact on Xenomai? A new sub-arch per real arch?
> Will Xenomai run stand-alone or together with a Linux kernel as on real
> silicon? In the former case, what will be the programming model,
> specifically regarding RT<->non-RT communication?

We are actually working out a standalone version of Xenomai (removing i-pipe) keeping 
the strict minimum of Linux functionalities in order to bootstrap a simple Xenomai domain (memory manager, .
I do not have yet a clear vision of how the RT/non-RT communication will look like, but probably
it will rely on the event channel mechanisms of XEN. Maybe Patrick can tell us more about that...

Daniel


> 
> Jan
> 
> --
> Siemens AG, Corporate Technology, CT SE 2
> Corporate Competence Center Embedded Linux