Re: Building a GNAT cross compiler

[jcreem@mailgw.sanders.lockheed.com (Jeff Creem)]

In article <32C94EB6.41C67EA6@innocon.com>, Jeff Carter
<carter@innocon.com> wrote:

>I find myself in the position of needing to build a GNAT cross compiler.
>While I have a great deal of software engineering and Ada experience, I
>have no experience with gcc (except running GNAT) or with compiler
>building.
>
>We are targeting a MIPS system under VxWorks, which comes with a gcc C
>cross compiler hosted on a Sun Sparc Solaris 2.4 system. VxWorks
>includes POSIX interfaces, so that part of the port should not be a
>problem. We also have a Solaris self-targeted gcc including GNAT 3.07.
>Finally, I have the GNAT 3.07 sources.
>


>End of search list.
> /usr/vw/gnu/lib/gcc-lib/sdebig/2.5.7/cc1 /var/tmp/cca000Vu.i -quiet
>-dumpbase numbers.c -version -o /var/tmp/cca000Vu.s
>GNU C version 2.5.7 [AL 1.1, MM 40] Algorithmics SDE-MIPS (big-endian)
>compiled by GNU C version 2.5.8.
> /usr/vw/gnu/lib/gcc-lib/sdebig/2.5.7/as -EB -v -o numbers.o
>/var/tmp/cca000Vu.s
>Algorithmics MIPS Assembler (version 1.4)
>
>from which I conclude that the cross compiler is gcc 2.7.2.
>


Hmm.. As far as I know the algorithmics compiler is not 2.7.2 its older.
(Maybe 2.5.7 by looking at the above).

If you were hosted on a SGI or something I think you'd be all set since
you could just get the latest gcc source code (or 2.7.2) and compile
a gcc cross to vxWorks but I think there is currently a problem getting
gcc to go cross to MIPS targets from a non MIPS architecture (something
about the file mips-tfile.c or something..I can't remember the
actual problem).

I played around with this for a little while myself (except I was doing
it from home on a linux box) and never really got anywhere (I could not
successfully built a new gcc cross from source which is basically your
first step).


There is something in the gcc docs that mentions that cross to MIPS is
not fully supported (which is where Algorithmics comes into play. I think they
add some of their own code to build the cross for MIPS).

If you get it working I'd be very interested...


(P.S. -- For your real target this may not be a problem. I think that
         on PowerPC this would work).