On Sun, Jul 3, 2022 at 1:48 PM Bakul Shah <bakul@iitbombay.org> wrote:

> Er.. a "microkernel" without an MMU is basically nothing more than a
> thread switcher (not unlike a variety of "realtime" embedded kernels like
> threadX and what not).
>
Argue with Andy and not me and read his book.   Andy calls it a
message-based uK.  Given how they structured it. I would agree.

>
> I think Tanenbaum's point was that MINIX3 is *nothing* like MINIX1 except
> in name.
>
Having talked to Andy about this in person, as well as looking at the code,
I think I differ with your interpretation

yes, M3 supports a ton of things M1 did not.  But the core API and KPI are
supersets.

I also know a bit about what Intel uses for the IPMI support as part of my
$ day job. Let's just say this is a great deal that is known outside of
Intel and a good bit that is not and/or misunderstood.

My point that started this rat hole was that Larry made a comment about V7
having little value.   I know for a fact Larry's observation was not true.
And how we use the core Minix subsystem (*as a basic V7 platform for a
single custom application* that allows us to manage the server - as I said
to Larry think the LS1-11 on the Vax and the 11/40 on the KL processors)
and offered it as a counter-example.   It could have been almost anything
that you called a thread switcher.  A simple V7 was 'good enough' and Minux
supplied that for the team.

In fact, I can think of other applications where V6 or V7 is more than
enough for a lot of the tasks.




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