Experimental Physics and
Industrial Control System

Peter Milne via Tech-talk <tech-talk at aps.anl.gov> · Fri, 22 May 2020 18:10:10 +0100

Hi Andrew

On 22/05/2020 16:27, Johnson, Andrew N. wrote:

Hi Peter,

On May 22, 2020, at 3:23 AM, Peter Milne via Tech-talk <tech-talk at aps.anl.gov<mailto:tech-talk at aps.anl.gov>> wrote:

We have a requirement to run pvaPy on a linux-arm system.
The ARM system is configured to provide a full EPICS7, Boost lib.

Following
https://github.com/epics-base/pvaPy/blob/master/README.md

Custom Build:

Seems to build fine for EPICS_HOST_ARCH=linux-x86_64

It's also putting in hooks for linux-arm:
ls ./src/pvaccess/O.linux-arm
Makefile

...

pgm TOP ../../.. T_A linux-arm
make[3]: Nothing to be done for 'install'.
make[3]: Leaving directory '/home/pgm/PROJECTS/EPICS/pvaPy/src/pvaccess/O.linux-arm'
make[2]: Leaving directory '/home/pgm/PROJECTS/EPICS/pvaPy/src/pvaccess'
make[1]: Leaving directory '/home/pgm/PROJECTS/EPICS/pvaPy/src'

.... does nothing..

Is there any way to enable a cross-compile?
I don't see any PROD_HOST entries that could be changed to PROD, for example.

The important entry in src/pvaccess/Makefile is the line

LOADABLE_LIBRARY_HOST += pvaccess

Since pvaPy is a dynamic library that gets loaded by Python, there are no binaries to create so no use of the PROD or PROD_HOST variables in the Makefile. Change the above to LOADABLE_LIBRARY and it should start cross-compiling for your target.

Yes, that's it!. Thank you. And, really generically the same idea as
PROD_HOST, should have spotted that.

So, the good news, it's trying to build.
The bad news, there are errors, maybe just one:

/usr/include/python3.7m/pyconfig.h:4:10: fatal error: pyconfig-32.h:

So the next step is to get it to look at the linux-arm version of the python headers rather than the HOST version..

... and that suddenly becomes really site-specific..

Hopefully you and Sinisa can work out some way to adjust the build so cross-builds like this can be configured more easily, but I suspect it may always need some kind of manual configuration to enable it.

.. as confirmed above.

Should be possible to make a configure/ option of course..

Thanks again Andrew

Cheers

Peter

- Andrew

--
Complexity comes for free, simplicity you have to work for.

--
Peter Milne
Director of Sales
www.d-tacq.com

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System