Re: Using GNAT with (or without) VxWorks

[dewar@cs.nyu.edu (Robert Dewar)]

John Clezy said

  Since I received no replies to the message below I presume no one
  actually uses gnat for embedded systems. To my mind that seriously
  limits its usefulness as al most all the work I have done has involved
  custom or COTS embedded computers. Ju st in case I'm wrong I have included the message again.

Don't presume that because no one reading CLA responds to you that something
does not exist! In fact there are a number of active projects using GNAT in
a cross-development environment, and it is perfectly possible to build a
gnat cross compiler. However, if you need to ask how it is done, then
probably you do not have the knowledge to do it yourself. This knowledge
can be acquired by study of the gcc and gnat materials, but it is not a
trivial task.

Right now, there are three relevant avenues of approach

  Some knowledgable users are building cross-compilers for themselves. These
  are users with a pretty good knowledge of and familiarity with gcc and the
  gcc environment. Note that we are NOT in a position to provide free help
  for people trying to learn how this is done!

  Second, we are working with the RTEMS folks who have already built some
  GNAT cross systems, and are now working on interfacing tasking to their
  tasking kernel. We antipate supported cross products using RTEMS to
  appear shortly. Look here for announcements in the near future about
  progress in this area.

  Third, TLD Systems has built GNAT cross-compilers, and has announced that
  it will use GNAT technology for its next generation of cross compilers
  implementing Ada 95 technology. Contact TLD systems directly for further
  information.

Finally, as always, if you want to know something about GNAT, it is a good
idea to contact the people who know about GNAT (either at report@gnat.com
for technical questions or at support@gnat.com for questions regarding
support of GNAT).

Regarding the specific question of whether it is possible to build a GNAT
cross-compiler that uses VxWorks as the runtime? Yes it is definitely
possible and at least one user has built such a system (I can't remember
who, it is not one of our supported users).

The important point here is that gcc is very much intended for cross
development work, and a lot of serious embedded work in the C world
uses gcc exclusively. Since GNAT is built on top of gcc, we have an
excellent path to generate cross compilers (note in particular that
all GNAT ports emanate via cross compilers from the original port for
Solaris, which is at least a proof of possibility!)

Robert Dewar
Ada Core Technologies