Re: How to use Assembly in Ada

[steve quinlan <steven.quinlan@lmco.com>]

I think something like this will work :

You define an Ada procedure or function with the parameters defined which
you want to pass to/from the assembler routine.

You would have a pragma import (Assembler, Ada_name, "link_name");
 link_name is optional if the assembler entry point name is the same as the
Ada name. But it might have to have a period or something. Sometimes pragma
import (C ..)  works just as well for assembler code.

You need to know the passing conventions of the compiler -- what registers
does it pass those parameters in? Vendors are supposed to document their
calling conventions, but I don't know where it would be in the GNAT
documentation. You can compile some sample calls with the option to get
assembler listings and check how they do it. Then, you write your assembler
routines to access/return values in the registers which the compiler has
used for the parameters of interest.

Now, assemble your assembler routine, compile the Ada,  passing the object
file generated by the assembler to the linker when you link the Ada program
and -- Voila'.