From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,f948976d12c7ee33 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-06-23 04:44:10 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!cyclone.bc.net!tdsnet-transit!newspeer.tds.net!news.binc.net!kilgallen From: Kilgallen@SpamCop.net (Larry Kilgallen) Newsgroups: comp.lang.ada Subject: Re: Boeing and Dreamliner Date: 23 Jun 2003 06:43:54 -0500 Organization: LJK Software Message-ID: References: <20030619221951073-0500@library.airnews.net> NNTP-Posting-Host: eisner.encompasserve.org X-Trace: grandcanyon.binc.net 1056368630 8241 192.135.80.34 (23 Jun 2003 11:43:50 GMT) X-Complaints-To: abuse@binc.net NNTP-Posting-Date: Mon, 23 Jun 2003 11:43:50 +0000 (UTC) Xref: archiver1.google.com comp.lang.ada:39594 Date: 2003-06-23T06:43:54-05:00 List-Id: In article , bitbucket@invalid-domain-see-sig.nil (Robert Kaiser) writes: > In article , > "Mark A. Biggar" writes: >> If I was part of the 7E7 design team I would >> insist that the "internet aboard" system be a complete isolated stand >> alone system that shared at most power supply with the rest of the >> plane. And if I were part of the FAA certification team I wouldn't >> approve it otherwise. > > Is physical isolation of the system really a requirement? AFAIK DO-178B > explicitly allows for software partitioning. (I.e. suppose I had a kernel > that can provide -say- an Ada runtime system and a Linux environment > in the same physical machine, protected from each other by the MMU, and > I could prove that there is no way for those systems to interfere.) I don't understand how a Memory Management Unit could keep one of those partitions from grabbing all the CPU time.