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From: Martin <martin.dowie@btopenworld.com>
Newsgroups: comp.lang.ada
Subject: Re: OT?: AF 447 and avionics software
Date: Tue, 9 Jun 2009 15:14:01 -0700 (PDT)
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Date: 2009-06-09T15:14:01-07:00
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On Jun 9, 10:06=A0pm, 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