From: ggm@algebras.org (George Michaelson)
Subject: [TUHS] Windows roots and Unix influence (was Re: Happy birthday, Ken Thompson!)
Date: Tue, 6 Feb 2018 09:52:42 +1000 [thread overview]
Message-ID: <CAKr6gn18=PTq5EYxwPZ8hgpF7JhWiQ6YxuTydj1ya2PrVE3ZSQ@mail.gmail.com> (raw)
In-Reply-To: <db90f0ec-9479-accc-5d2e-64fb3ee4f363@kilonet.net>
My understanding is that FAA rated 'ethernet' switches for aircraft
are modified ASICs which do TDM. You program in slot reservations, and
this is used to give bounded-time delivery guarantees for flight
critical stuff. Cheaper to make by modifying existing stuff, the
physical and link layer code is almost identical, its just put into a
timeslot regime. Its fully isochronous for the flight control and its
best effort delivery for the entertainment.
So, when people talk about the entertainment being 'isolated' its not
opto-isolated and its not airgap discrete switch isolated: the TDM
bitfield excludes the customers from talking in the timeslots for the
flight control logic.
I think the imputed hack, was to "see" the flight control sequences
because you can probably fake out read-side, and get passive view of
them if you can make the ports broadcast-receive. I am really
unconvinced anyone succeeded in write-mode into this model. Not that
it couldn't happen and not that I believe I'm smarted than bad people:
I just thing the descriptions have the quality of urban myth right
now.
On Tue, Feb 6, 2018 at 9:36 AM, Arthur Krewat <krewat at kilonet.net> wrote:
> Sorry, Thunderbird strikes again. I highlighted the text to include, and it
> didn't put the correct address on the quote.
>
> My apologies.
>
>
> On 2/5/2018 6:28 PM, Dave Horsfall wrote:
>>
>> On Mon, 5 Feb 2018, Arthur Krewat wrote:
>>
>>> On 2/5/2018 4:57 PM, Ron Natalie wrote:
>>>>
>>>> There's certainly been demonstrations of vehicles being taken over via
>>>> the entertainment system; why the stereo needs to talk to the engine
>>>> computer I'll never know... I know, wind up the volume the faster you go
>>>> etc, but surely it ought to be one-way?
>>
>>
>> Umm, I wrote that, not Ron...
>>
>
next prev parent reply other threads:[~2018-02-05 23:52 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-04 0:37 Dan Cross
2018-02-04 2:59 ` Nemo Nusquam
2018-02-04 5:06 ` Wesley Parish
2018-02-04 5:18 ` Warner Losh
2018-02-05 19:43 ` Paul Winalski
2018-02-05 21:19 ` Michael Kjörling
2018-02-06 0:37 ` Steve Nickolas
2018-02-06 0:45 ` Warner Losh
2018-02-06 9:14 ` Wesley Parish
2018-02-04 9:14 ` Angelo Papenhoff
2018-02-04 14:15 ` arnold
2018-02-04 17:21 ` Ron Natalie
2018-02-04 20:05 ` Dan Cross
2018-02-04 20:55 ` Nemo
2018-02-04 20:57 ` Warner Losh
2018-02-04 20:59 ` Jon Steinhart
2018-02-04 22:12 ` Clem Cole
2018-02-05 1:32 ` William Cheswick
2018-02-05 1:44 ` Dave Horsfall
2018-02-04 21:04 ` Toby Thain
2018-02-04 22:22 ` Andy Kosela
2018-02-04 22:43 ` Dave Horsfall
2018-02-04 22:54 ` George Michaelson
2018-02-05 3:35 ` Ron Natalie
2018-02-05 3:40 ` Dan Cross
2018-02-05 13:48 ` William Cheswick
2018-02-05 14:31 ` Ron Natalie
2018-02-05 21:51 ` Dave Horsfall
2018-02-05 21:57 ` Ron Natalie
2018-02-05 22:31 ` Grant Taylor
2018-02-05 23:16 ` Arthur Krewat
2018-02-05 23:49 ` Grant Taylor
2018-02-06 17:42 ` Ron Natalie
2018-02-06 18:23 ` Arthur Krewat
2018-02-05 23:10 ` Charles Anthony
2018-02-05 23:20 ` Arthur Krewat
2018-02-05 23:28 ` Dave Horsfall
2018-02-05 23:36 ` Arthur Krewat
2018-02-05 23:52 ` George Michaelson [this message]
2018-02-06 14:52 ` Steffen Nurpmeso
2018-02-05 23:18 ` Lyndon Nerenberg
2018-02-06 21:51 ` Dan Cross
2018-02-06 23:14 ` Nemo Nusquam
2018-02-06 23:22 ` Warner Losh
2018-02-07 3:03 ` Dave Horsfall
2018-02-07 1:23 ` Dave Horsfall
2018-02-07 1:33 ` Clem Cole
2018-02-07 1:54 ` Dan Cross
2018-02-07 18:01 ` Tony Finch
2018-02-09 2:35 ` Wesley Parish
2018-02-07 18:50 ` Bakul Shah
2018-02-15 13:23 ` Tim Bradshaw
2018-02-05 0:27 ` Kurt H Maier
2018-02-05 0:41 ` Robert Brockway
2018-02-04 9:11 ` Donald ODona
2018-02-04 23:25 ` Dave Horsfall
2018-02-04 23:46 ` Bakul Shah
2018-02-04 23:58 ` Dave Horsfall
2018-02-05 0:06 ` Robert Brockway
2018-02-05 5:37 ` Steve Johnson
2018-02-05 5:53 ` Greg 'groggy' Lehey
2018-02-05 10:49 ` Ron Natalie
2018-02-05 6:57 ` Robert Brockway
2018-02-05 15:20 Doug McIlroy
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