Re: Ada, the best language with the not-so-best tool chain

[Brian Drummond <brian@shapes.demon.co.uk>]

On Tue, 09 Oct 2012 08:59:25 +0300, Niklas Holsti wrote:

> On 12-10-09 00:28 , Ludovic Brenta wrote:
>> Patrick writes on comp.lang.ada:
>> 
>> * bare-metal programming is _very_ difficult in any language.
> 
> Yes and no; some small bare metal systems are easy (on reset, the
> processor starts running from address zero with a workable initial
> state); others are much harder to get running (as you say in a later
> point, not quoted).

Yes. Bare metal programming on a Z80 is easy. Ditto PIC, AVR, etc etc, 
and of these only the AVR has an Ada toolchain. It may not be mature but 
it is very usable. (We need to get Warren's thread library into the 
mainstream though)

Bare metal on a typical ARM SOC ... not so much.

Though with an ARM dev board "available" for $5, ("available" stays in 
quotes until mine arrives, probably in November)
http://hackaday.com/2012/08/31/preorder-tis-arm-cortex-m4-launchpad-for-5-
delivered/
the ARM in all its varieties would be a good next target for the Ada 
community to focus on. There certainly are ARM Ada compilers, but I'm not 
sure they are even as mature as AVR-Ada. It's not immediately clear to me 
which variant I would start with for any particular ARM processor or 
board, or what RTS it provides. (With one exception : Debian on the R-
Pi). The Gnat Android project would be part of this family, and it too 
seems to have stalled.

> But every small board or processor-on-a-USB-stick that I have seen comes
> with a C toolchain that handles the bootstrap, and you can get a
> LED-blinker running very easily. Not so for Ada, except for the small
> number of systems already mentioned (MaRTE OS; Ada for Lego Mindstorms;
> GNAT for AVR).

What other small targets does gcc support? One approach would be to build 
for another of these with Ada support, and provide a minimal library 
along AVR-Ada lines. This would be an approachable project for a small 
community or a class project.

Or me, unless I get a job offer soon...

> I don't think this problem is a consequence of the Ada language
> properties, but shows the relative commercial success and penetration of
> C and Ada in small embedded systems.

I think with ARM and AVR covered, Ada should be in a better place than it 
is. But even in the Arduino community, AVR-Ada goes almost unnoticed.
So part of the problem is publicity and exposure, and those need not be 
expensive to address.

- Brian