Re: Ada and ASM

[David Marceau <davidmarceau@sympatico.ca>]

Jerry van Dijk wrote:
> 
> Simon Wright <simon@pushface.org> writes:
> 
> > > Volatile%20Parameter
> > > Asm ("movl %0, %%ebx" & LF & HT &
> > >           "movl %%ebx, %1",
> > >           Inputs   => Unsigned_32'Asm_Input  ("g", Var_In),
> > >           Outputs  => Unsigned_32'Asm_Output ("=g", Var_Out),
> > >           Clobber  => "ebx",
> > >           Volatile => True);
> > > The actual Asm statement still is a quoted string. It is not Ada syntax.
> >
> > I do not understand how it could possibly "[be] Ada syntax".
> >
> > OP wanted to include an asm *routine*, I think, so perhaps what is
> > wanted instead is a pragma Import (Asm, ...)? (if suoported).
> 
> No, you can include a ASM routine very easily this way (although, yes, one
> does need to actually read the documentation first :-).
> 
> Note that this has three big advantages over a separately assembled function:
> 1) no need to use non Ada tools
> 2) easy access to other Ada objects
> 3) optimizer can help
> 
> --
> --  Jerry van Dijk, Leiden, Holland
> --  Note that email address is invalid
1)I think Mr. van Dijk's inline assembler in ada tutorial(on adapower
and part of ACT/GNAT docs) is the most straightforward and most fluid. 
Lots of gnu.org site borrows from your doc but IMHO the flow changed and
to get a better picture I do suggest to look at both the adapower
version and also the gnu.org version of the documentation.  

2)Check out http://studwww.rug.ac.be/~fcorneli/eduos
The link doesn't seem to be working at the moment but the document is
called:
"Making plain binary  
files using a C compiler (i386+) Cornelis Frank
<Frank.Cornelis@rug.ac.be> April 27, 2001
"
The actual doc explains much about generating assembler files from C
files and the helper tools around all this.
It also mentions a bit about nasm for those who were looking for it.  It
is an excellent supplemental to the ada inline assembler docs.

3)Last but not least, Mr. Simon Knipe <sknipe@ktc.com> has made a
wonderful tutorial to make an Ada OS:
http://www.ktc.com/~sknipe/EOSA.html
I suggest examining its sources showing the usage of nasm and Ada
bridging them together using "pragma import" to make an OS.
There are a lot of cool tidbits in here that could equally apply to
in-line ada assembler.
One of the people on this thread was looking for pragma import stuff
using nasm well here it is :)

4)A bit off topic but still related because it does talk about getting
closer to metal.(spec'ing to cpu/dsp/controller chips)
It is also a great place demonstrating ada's strong concurrency
mechanisms with sources.
http://cs.anu.edu.au/student/comp4710/Lectures/RTES.book.e.pdf
http://cs.anu.edu.au/student/comp4710/Level-0/Sources.html

I hope this helps :)

Cheers,
David Marceau