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

[Shark8 <onewingedshark@gmail.com>]

On Tuesday, March 26, 2013 3:27:55 PM UTC-6, Diogenes wrote:
> Anyone know if there's a list of what parts of the Ada language can be compiled statically without any Runtime whatsoever?

That's a very good question.
Sadly I have no answer for you -- I know Tasking and certain attributes, like 'Image, need it.

> 
> I realize that the default GNAT installations will link to the runtime regardless, but I was wondering if it's possible to write startup code in Ada with a bit of assembler thrown in(possibly inline)? Thinking of maybe writing an art0.o, art1.o(Ada Runtime, as opposed to crt0.o for the C Runtime).

Nah, call it something like "Applied Diversified Ada Runtime" (ADA_Runtime)...
;)


> 
> I can get a good bit of it running by linking with musl-libc, but the next step is doing Ada/Assembler startup code followed by direct calls to the kernel itself.(Using clone() and futex() instead of pthreads for example).

That may be a bad call, if I'm reading you right.

Wouldn't it be best to write it first in a way so your [hardware] dependencies are in one spot and secondly [and possibly separately] the platform-dependence? {IOW, get it to a state where a no-OS body could be supplied as well as an optimized-for-the-OS. Tying your runtime to pthreads [POSIX] early on might be a rather bad idea... as you don't want to force POSIX on the people who would want bare-metal access [or conceivably their own OS].}

> 
> I'm suspecting I'll be limited to procedures and functions exclusively, but hey, at this level that's all I'll need to get started.

That's certainly a good thing.