Re: OT?: AF 447 and avionics software

[MRE <Marc.Enzmann@web.de>]

On 10 Jun., 00:14, Martin <martin.do...@btopenworld.com> wrote:
> On Jun 9, 10:06 pm, Olivier Scalbert <olivier.scalb...@algosyn.com>
> wrote:
>
>
>
> > Ludovic Brenta wrote:
> > > dedicated hardware. Consolidating multiple systems on a single
> > > hardware CPU (aka Integrated Modular Avionics) is the trend nowadays;
> > > it requires partitioning the CPU into multiple virtual machines
> > > running software certified for different criticality levels.
>
> > > [1]http://www.cs.kuleuven.ac.be/~dirk/ada-belgium/events/07/070612-abga-...
>
> > > --
> > > Ludovic Brenta.
>
> > Hi Ludovic,
>
> > Consolidating multiple systems on a single CPU, is not it too dangerous
> > (single point of failure) ?
>
> > Olivier
>
> From the s/w side, the different systems would be separated into their
> own VM, so any one of the s/w apps going down would not affect any
> other system. You get this sort of separation in a lot of embedded OS
> these days, e.g. Green Hills Integrity.
>
> From the h/w side, the risk of the single CPU going down would have to
> be considered and mitigated in the system safety hazard analysis. - it
> depends on your risk requirements.
>
> Cheers
> -- Martin

It is being considered. The (original) ideal of IMA being that one
faulty
system will be switched off and some other CPU will take the task (the
"M"
in IMA representing "Modular").

Cheers,

Marc