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=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: Paul Rubin <no.email@nospam.invalid>
Newsgroups: comp.lang.ada
Subject: Re: ANN: Cortex GNAT RTS 2018-07-15
Date: Fri, 27 Jul 2018 13:51:39 -0700
Organization: A noiseless patient Spider
Message-ID: <87in50e71g.fsf@nightsong.com>
References: <ly1sc4ffrq.fsf@pushface.org> <87in5gf9nt.fsf@nightsong.com>
	<lywotve6ma.fsf@pushface.org> <87wothrqrs.fsf@nightsong.com>
	<lyd0v8qvln.fsf@pushface.org>
Mime-Version: 1.0
Content-Type: text/plain
Injection-Info: reader02.eternal-september.org;
 posting-host="465eefdafb258f2581187c15f86634f1";
	logging-data="22591"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX1/k0eKl13+5J96JlePapFIz"
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux)
Cancel-Lock: sha1:7VeHhPiB+iPXXegsIhcxMJg+knw=
	sha1:3rr9NFEITGRxBicbCDna8wFvDK0=
Xref: reader02.eternal-september.org comp.lang.ada:53988
Date: 2018-07-27T13:51:39-07:00
List-Id: <comp.lang.ada>

Simon Wright <simon@pushface.org> writes:
> I agree that a considerable chunk of FreeRTOS could probably be replaced
> by straightforward Ada code, but that'd be someone else's project!

Thanks.  I wasn't suggesting that you rewrite FreeRTOS, but rather, I
was just wondering if there were technical obstacles to doing such such
machine-level stuff in Ada.

> The RTOS part of AdaCore's embedded Ravenscar RTOSs (s-bb*.ad?) is about
> 5500 lines (1250 semicolons) of Ada.

Fabien also Chouteau mentioned this.  Does it do mostly the same stuff
as FreeRTOS?  I had thought Ravenscar was deliberately very limited.

I've never used a thing like this and I've seen some incredibly tiny
Forth multitaskers, like a few dozen lines of code.  They basically
implement a context switch called from a cooperative PAUSE primitive,
plus a round robin scheduler and a few other things for starting and
stopping tasks.  So I should try to figure out what additional functions
the RTOS does.