Re: Point a beginner in the right direction? Cheap bare-board to run with a RTOS for running ADA

["Randy Brukardt" <randy@rrsoftware.com>]

"Simon Clubley" <clubley@remove_me.eisner.decus.org-Earth.UFP> wrote in 
message news:krh26d$8b0$1@dont-email.me...
> On 2013-07-09, Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
...
> What is needed is to create a Ada compiler which will create code which
> runs in bare metal mode on a number of specific architectures (ARM and
> MIPS would be my personal initial preferences).

I agree with Dmitry, this sounds like nonsense. Certainly you can write a 
cross-compiler, but it can't "target bare-metal". Most machines need a 
substantial RTS to support anything. The Z80s that we targeted when we 
started out didn't even support multiple and divide in hardware -- you would 
have been limited to plus and minus (and no arrays, as those require 
multiplying to do indexing) without an RTS.

Early Janus/Ada was available for bare-metal (still is, nominally) -- we 
provided the source code of the RTS and customers could tailor it to their 
actual hardware board. But there was no way to make that process portable in 
any sense -- every hardware implementation was different. And nothing I've 
heard here suggests that anything has changed in that respect.

So it makes sense to target a particular board (Lego Mindstorms, Raspberry 
PI), but targeting all boards is nonsense.

> At this point, I'm beginning to think you are either trolling or just
> refusing to accept (for whatever reason) that there's a vast embedded
> market out there, outside of what you are used to, which could be a
> target for Ada.

I started out creating tiny Ada subsets, and I've come to believe that those 
do Ada far more harm than good. The only sort of Ada that can run on those 
targets is an emasculated Ada that is likely to repell, rather than attract 
people to "real" Ada down the road. (And yes, I feel that way about Spark 
and Ravenscar, too; those both are rooted in the technology limitations of 
the 1990s and one would hope that we can now move on to more generally 
useful things.)

> Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
> Microsoft: Bringing you 1980s technology to a 21st century world

And that's what Ada (and Linux) is doing, too. It's only become practical to 
use a lot of that 80s technology in very recent years. (Plus it works well, 
why change for the sake of change?) Why single out Microsoft for this?
Besides, that is *exactly* what you want people to do (go back to 1980s Ada 
subsets); it is really silly to advocate in a message for doing the very 
thing that your signature is railing against.

                                    Randy.