Re: minimal hardware for ada (newbie)

[Niklas Holsti <nholsti@icon.fi>]

Tucker Taft wrote:
> 
> We have developed (and recently validated) a version of our
> AdaMagic technology which uses optimized ANSI C as its intermediate
> representation.  One of the reasons was to allow a programming team to
> write their source code in Ada, while relying only on the availability
> of an ANSI C compiler for their chosen target.  We also have
> a version of the Ada run-time that at the lowest level depends
> only on routines included in the standard ANSI C run-time.

I'm working on an I8051 program to control a space-based instrument,
and have again experienced the pain of working in C. Using
AdaMagic-to-C would have been nice, however I think it would
only be practical if one can make the C code use the typical
I8051 C extensions to ANSI C, such as controlling the memory space
for each variable. In Keil C51, for example, one of the new
keywords 'data', 'idata', 'pdata' or 'xdata' is placed in the
variable declaration between the type-id and the variable-id
to determine the memory space.

While one could implement one's own postprocessor to mutilate the
C code in this way, it would be simpler and safer to make the
necessary annotations in the Ada code, perhaps as pragmas on
the variables or types. Does AdaMagic provide anything like this?

Moreover, given the limited architecture of the I8051, it seems
unlikely that a run-time using only ANSI C routines could perform
within an order of magnitude of a kernel designed for the
I8051. Any data on this? For example, how does your ANSI-C-based
run-time handle the stack when switching tasks?

TIA

Niklas Holsti
Working at but not speaking for Space Systems Finland Ltd.