Re: Runtime startup code for the GNAT Runtime...and a bit of humble pie.

[Diogenes <phathax0r@gmail.com>]

On Wednesday, March 27, 2013 3:07:37 PM UTC-4, Randy Brukardt wrote:
 
 
> 
> That's obviously compiler-specific (and probably specific to particular 
> 
> compiler versions as well). You need to specify a compiler and version to 
> 
> have any hope of a useful answer. (Certainly the answer is wildly different 
> 
> for Janus/Ada vs. GNAT vs. ObjectAda.)
> 
> 
> 
> I really wouldn't expect such a list to exist. We don't have one for 
> 
> Janus/Ada, for instance; it's certainly the case that there are many things 
> 
> that require minimal runtime support but we've never had any reason to 
> 
> figure it out.

I was considering the bootstrapping procedure actually. I was curious if it was possible to do the actual startup code in Ada, with maybe a little Assembler thrown in.
No doubt that it's compiler specific. I'm using GNAT/GCC 4.4
 
> 
> Janus/Ada always assumes a small runtime. Since we provide the complete 
> 
> source code to the runtime in the professional packages, and the code 
> 
> includes a number of minimal support switches, you could make a version that 
> 
> requires nothing but memory setup and some form of "put_line" without too 
> 
> much trouble. (We used to sell embedded versions for bare 16-bit processors, 
> 
> but that business didn't translate to 32-bit processors.) I suspect that the 
> 
> situation is similar for GNAT.
> 
> 
> 
> As far as correctness goes, that's what the ACATS is for. (Figuring out how 
> 
> to run it on a bare machine might be interesting, however.) It won't prove 
> 
> that absolutely everything works, but you'll get a fair certainty that you 
> 
> didn't make any major mistakes.
 
Combine that with the SPARK tools and I can be even more certain.
 
> 
>                                 Randy.


Diogenes