GNAT for Cross Compilation

GNAT for Cross Compilation

[Kendall Lemley]

Hi-

   I am fairly new to GNAT and am interrested in trying to set it up to
cross compile Ada code for a student research project.  Our host machine
is a Sun Sparc (running SunOS4.1.3) and the target is a 68030 board.  I
have gotten GNAT 3.05 up and running on the native SUN (I assume this is
the first step).  However, I have been unable to find any documentation
on how to proceed to set up the cross compiler.  Has anyone out there
done this before, or know where I might look to learn how to do this?

Thanks-
Kendall Lemley
klemley@afit.af.mil

Re: GNAT for Cross Compilation

[Chris Nettleton]

Kendall Lemley <klemley@afit.af.mil> wrote:

>Hi-
>
>   I am fairly new to GNAT and am interrested in trying to set it up to
>cross compile Ada code for a student research project.  Our host machine
>is a Sun Sparc (running SunOS4.1.3) and the target is a 68030 board.  I
>have gotten GNAT 3.05 up and running on the native SUN (I assume this is
>the first step).  However, I have been unable to find any documentation
>on how to proceed to set up the cross compiler.  Has anyone out there
>done this before, or know where I might look to learn how to do this?

We are in the process if building a cross compilation system for a
68020 board. The compiler itself is not much of a problem once you've
sorted out what to call the various programs (e.g. m68k-coff-gcc), and
updated programs like gnatmake to call the cross compiler. The bulk of
the implementation effort is in the run-time system and debugger
support. 

Assuming you have a bare board target computer, then you will need to
provide the basic C libraries such as libc, libm, libpthreads if you
plan to support the full Ada 95 language. On the other hand if you
don't plan to use input-output, memory management or tasking then you
can get away with a mimimal run-time system that initialises the stack
and calls the main program.

Re: GNAT for Cross Compilation

[Robert Dewar]

Kendall said

"   I am fairly new to GNAT and am interrested in trying to set it up to
cross compile Ada code for a student research project.  Our host machine
is a Sun Sparc (running SunOS4.1.3) and the target is a 68030 board.  I
have gotten GNAT 3.05 up and running on the native SUN (I assume this is
the first step).  However, I have been unable to find any documentation
on how to proceed to set up the cross compiler.  Has anyone out there
done this before, or know where I might look to learn how to do this?"

It is not clear what you mean by "have gotten GNAT 3.05 up and running on
the native SUN". The first step is to be able to do this *from the source
distribution* so that you can indeed build gcc from its sources.

Building a cross-compiler involves quite a bit of tricky fiddling around,
and requires a fair amount of familiarity with gcc and the gnat make file.
We are currently working on improving the cross-compiler build procedures
to make them easier.