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

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

ROSSIER Daniel wrote:
>> -----Original Message-----
>> From: Jan Kiszka [mailto:jan.kiszka@domain.hid]
>> Sent: lundi, 22. juin 2009 15:55
>> To: ROSSIER Daniel
>> Cc: Johan Visser; xenomai@xenomai.org
>> 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...

Maybe a stupid question: but does the Xen domain/context switch routine
flush the cache?

-- 
                                          Gilles