[Buildroot] Makefile.mk to compile using openmpi

[Buildroot] Makefile.mk to compile using openmpi

[Marco Espinoza]

Hello

I'm using buildroot to generate an image for a zedboard. And I'm trying to
add an application which require openmpi compilation.
However I'm having issues, because my compilation is failing.
The issue I'm having is because my program requires mpicc compilation, but,
despite I have installed openmpi in my buildroot image, the
cross-compilation is not working.

Would you please help me telling what do I need in my *.mk file, to
cross-compile properly using buildroot  a program which requires mpicc?

Thanks
Marco Espinoza
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[Buildroot] Makefile.mk to compile using openmpi

[Arnout Vandecappelle]

On 19-05-18 18:44, Marco Espinoza wrote:
> Hello
> 
> I'm using buildroot to generate an image for a zedboard. And I'm trying to
> add an application which require openmpi compilation.
> However I'm having issues, because my compilation is failing.
> The issue I'm having is because my program requires mpicc compilation, but,
> despite I have installed openmpi in my buildroot image, the
> cross-compilation is not working.
> 
> Would you please help me telling what do I need in my *.mk file, to
> cross-compile properly using buildroot  a program which requires mpicc?

 I guess you need to have an mpicc built for the host, and it looks like the
openmpi build system is not really cross-compile friendly. The easiest approach
is to make a host-openmpi package. But some additional work will be needed, to
make sure the opal_wrapper calls the target toolchain with the appropriate
CFLAGS instead of the host toolchain...

 Regards,
 Arnout

> 
> Thanks
> Marco Espinoza
> 
> 
> 
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot
> 

-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF

[Buildroot] Makefile.mk to compile using openmpi

[Marco Espinoza]

Hello

Thanks for your response.
I understand we need to add the proper CFLAGS for MPI, but I was anot able
to do the cross-compilation using CFLAGS.
Do you have a Makefile example with the proper CFLAGS to cross-compile MPI?

Thanks
Marco


2018-05-23 16:40 GMT-06:00 Arnout Vandecappelle <arnout@mind.be>:

>
>
> On 19-05-18 18:44, Marco Espinoza wrote:
> > Hello
> >
> > I'm using buildroot to generate an image for a zedboard. And I'm trying
> to
> > add an application which require openmpi compilation.
> > However I'm having issues, because my compilation is failing.
> > The issue I'm having is because my program requires mpicc compilation,
> but,
> > despite I have installed openmpi in my buildroot image, the
> > cross-compilation is not working.
> >
> > Would you please help me telling what do I need in my *.mk file, to
> > cross-compile properly using buildroot  a program which requires mpicc?
>
>  I guess you need to have an mpicc built for the host, and it looks like
> the
> openmpi build system is not really cross-compile friendly. The easiest
> approach
> is to make a host-openmpi package. But some additional work will be
> needed, to
> make sure the opal_wrapper calls the target toolchain with the appropriate
> CFLAGS instead of the host toolchain...
>
>  Regards,
>  Arnout
>
> >
> > Thanks
> > Marco Espinoza
> >
> >
> >
> > _______________________________________________
> > buildroot mailing list
> > buildroot at busybox.net
> > http://lists.busybox.net/mailman/listinfo/buildroot
> >
>
> --
> Arnout Vandecappelle                          arnout at mind be
> Senior Embedded Software Architect            +32-16-286500
> Essensium/Mind                                http://www.mind.be
> G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
> LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
> GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF
>
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[Buildroot] Makefile.mk to compile using openmpi

[Arnout Vandecappelle]

On 31-05-18 06:02, Marco Espinoza wrote:
> Hello
> 
> Thanks for your response.
> I understand we need to add the proper CFLAGS for MPI, but I was anot able to do
> the cross-compilation using CFLAGS.
> Do you have a Makefile example with the proper CFLAGS to cross-compile MPI?

 I don't entirely understand your question.

 The openmpi packages already does cross-compilation with the proper CFLAGS.
However, it also cross-compiles mpicc, so you can't execute it during the build.

 So to get mpicc, you have to build openmpi for the host as well. This could be
as simple as adding $(eval $(host-autotools-package)) at the end of openmpi.mk.
But most likely you'll need to add some options to HOST_OPENMPI_CONF_OPTS as well.


 Regards,
 Arnout

> 
> Thanks
> Marco
> [snip]
-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF