Re: Is an RTOS Required for Ada?

[Robert Dewar <dewar@gnat.com>]

In article <19990514155120.03860.00000396@ng-cr1.aol.com>,
  tramse@aol.com (Tramse) wrote:
> I've heard of GNAT, are their many users of GNORT?  Does
> anyone have experience
> in running GNORT on Linux with a 68K target?  Are their any
> debugging tools?

Just to be clear. GNORT is only appropriate if you have a
safety-critical certification requirement. Otherwise there is
no need to exclude minimal run-time routines.

For example, in GNORT mode, the compiler will generate an open
loop for a block copy, to avoid calling the bcopy routine in
the run-time. Now of course this is a trivial routine, and in
a normal circumstance there is no reason not to include it. But
in a certified environment, you don't want even one byte of
non-certified code around, and GNORT meets this requirement
inexpensively and convincingly by having no bytes of run-time
code of any kind around.

But if you don't have a certification requirement, then there
are lots of routines in the library that can be freely used.
For example, there is no reason not to use the sorting routine
in the GNAT library, or the random number generator in the Ada
library, and there are literally hundreds of other library
run-time routines that may be perfectly appropriate to use in
the limited environment you have in mind without requiring
RTOS services. Basically the RTOS is required for I/O, Tasking,
and Interrupt services. If you avoid these requirements, you
do not need an RTOS.

Robert Dewar
Ada Core Technologies


--== Sent via Deja.com http://www.deja.com/ ==--
---Share what you know. Learn what you don't.---