[TUHS] CMU Mach sources?

arnold at skeeve.com arnold at skeeve.com
Thu Jun 27 20:59:34 AEST 2019


Larry McVoy writes:
> >> OK, I'll bite.  Go read the source in the FreeBSD tree, which has been 
> >> reduced in size by 60% according to someone on the team.  Then come
> >> back and draw me a picture of what it does.

On Jun 27, 2019, at 12:01 AM, Lyndon Nerenberg <lyndon at orthanc.ca> wrote:
> > Larry, it seems to me your argument is the Mach code should never
> > have been incorporated into BSD in the first place.  That's fine,
> > but it's not the Mach developers fault that happened, so maybe you
> > should lay off them for not writing their research software to a
> > production shop standard they were never a part of?

Ben Greenfield via TUHS <tuhs at minnie.tuhs.org> wrote:
>  My understanding is that the  BSD layer was a requirement from DARPA.
> DARPA wanted a “normal” interface to the kernel and BSD was that interface.

Yes, Mach had to provide a BSD layer on top, but that's not the source
of Larry's gripes.

It's the other way around. 4.4 BSD pulled the VM code out of Mach and
into BSD to provide mmap and some level of portability off the Vax. From
there the Mach code got into FreeBSD.  That's what Larry is complaining
about and what Lyndon is saying isn't fair to the Mach guys.

Thanks,

Arnold


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