Re: GNORT

Re: GNORT

[Robert Dewar]

Markus asks

<<How is this activated in GNAT? Do I just have to write something like

  pragma Restrictions(No_Exceptions, Max_Tasks => 0);

and the run-time system is gone?
>>

this = GNORT


No, it is a special pragma (pragma No_Runtime)
(it is equivalent to a set of restrictions, plus does some other things!)

Re: GNORT

[Markus Kuhn]

Robert Dewar wrote:
> As for "don't admit programs which have runtime systems". There is nothing
> about Ada that requires that every Ada program needs a runtime system. Indeed,
> GNAT provides a capability, which we call GNORT (GNAT with No RUntime) that
> does what it says. Allows the compilation of programs with absolutely no
> runtime.

How is this activated in GNAT? Do I just have to write something like

  pragma Restrictions(No_Exceptions, Max_Tasks => 0);

and the run-time system is gone?

Markus

-- 
Markus G. Kuhn, Security Group, Computer Lab, Cambridge University, UK
email: mkuhn at acm.org,  home page: <http://www.cl.cam.ac.uk/~mgk25/>

GNORT

[Tramse]

Are their many users of GNORT?  Does anyone have experience in running GNORT on
Linux with a 68K target?  Are their any debugging tools?

Re: GNORT

[Robert Dewar]

In article <19990514155154.03860.00000397@ng-cr1.aol.com>,
  tramse@aol.com (Tramse) wrote:
> Are their many users of GNORT?  Does anyone have experience in
> running GNORT on Linux with a 68K target?  Are their any
> debugging tools?

GNORT is the GNAT No-Run-Time technology, which allows GNAT to
generate programs for a subset of Ada with absolutely no
run-time being used at all, not even one byte.

The subset is comparable to SPARK-95, with the notable point
that full generics are allowed. GNORT is intended specifically
for safety-critical use where certification is an issue (for
other embedded applications without this requirement, it is
usually more appropriate to consider a larger subset of Ada,
for example that provided by the restricted run-time option
in GNAT, which roughly corresponds to the Ravenscar profile.
This will be fully supported in version 3.12.

There is one large scale user of GNORT technology to develop
a large safety critical program. They are using an OS/2 host
and a bare x86 board. Using a Linux host would be essentially
identical to this. This project has been going for a while, and
is the one for which GNORT technology was originally developed.

A number of other customers have started using GNORT more
recently (this is fairly recent technology).

As for debugging tools, GNORT generates standard format object
modules, and any tool chain can be used to deliver and debug
the result. Note that the GNAT approach of using C-compatible
debugging information (which encodes the Ada information needed)
means that a C-based debugger can be used to debug GNAT code.
Another approach is to use the VxWorks environment, where in the
final delivery, the VxWorks kernel is simply excluded, but
during development, the standard GnatWorks debugging interface
can be used (several GNORT customers have adopted this
approach).

Since GNORT applications tend to be specialized, the best way to
pursue the question of whether a specific application is a
sensible match for GNORT technology is to send mail to
sales@gnat.com or sales@act-europe.fr outlining your interest,
and we can have an appropriate technical person contact you to
discuss your specific application.

Robert Dewar
Ada Core Technologies


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