Experimental Physics and
Industrial Control System

"Johnson, Andrew N. via Tech-talk" <tech-talk at aps.anl.gov> · Tue, 11 Feb 2020 18:18:10 +0000

Support for the _<osclass> versions of the make variables is provided in the EPICS build system, but not for the _<target-arch> versions, hence the need for the second line. There are other ways to do this kind of conditional, but I think the variable name approach that we use is easier to read than wrapping lines inside GNUmake conditionals.

- Andrew

-- 
Sent from my iPad

> On Feb 11, 2020, at 5:21 PM, Florian Feldbauer <florian at ep1.ruhr-uni-bochum.de> wrote:
> 
> Hey Andrew,
> 
> thanks for the answer. I thought about this idea, but in the developers guide (base 3.15) only PROC_IOC_<osclass> was mentioned.
> Good to know one can also define this for single target archs.
> 
> Florian
> 
>> Am 11.02.2020 um 18:16 schrieb Johnson, Andrew N.:
>> Hi Florian,
>> 
>> Thanks for the clarification. The way to handle this is to adjust the Makefile that compiles the IOC so it *only* tries to build and link the IOC program for the linux-arm target, not for the Linux host. There is a slight trick to doing this, but it’s usually a simple one-line addition.
>> 
>> Where the Makefile says something like
>> 
>>   PROD_IOC = <iocname>
>> 
>> replace it with this:
>> 
>>   PROD_IOC_linux-arm = <iocname>
>>   PROD_IOC += $(PROD_IOC_$(T_A))
>> 
>> When building any architecture other than linux-arm the second line will evaluate to nothing, so nothing will be built.
>> 
>> HTH,
>> 
>> - Andrew
>> 
>> 
>> 
>>>> On Feb 11, 2020, at 10:52 AM, Florian Feldbauer via Tech-talk <tech-talk at aps.anl.gov> wrote:
>>> 
>>> Hey Michael,
>>> 
>>> as far as I understood, they would like to build everything (base, support modules and IOC) just for the target arch.
>>> But the error occurs for the IOC (which contains a custom support module)
>>> 
>>> The missing library is the libisegHal which is only build for linux-arm as a part of the same yocto image.
>>> The library is needed for iseg's support module.
>>> 
>>> Cheers,
>>> Florian
>>> 
>>> Am 11.02.2020 um 16:34 schrieb Michael Davidsaver:
>>>> Can you clarify a couple of points?
>>>> 
>>>> Are you referring to building EPICS Base itself, or a support module / IOC application?
>>>> 
>>>> Which libraries are missing?  (this might answer the previous question)
>>>> 
>>>> 
>>>> On 2/11/20 5:27 AM, Florian Feldbauer via Tech-talk wrote:
>>>>> Hey all,
>>>>> 
>>>>> I was contacted by iseg with the following problem:
>>>>> 
>>>>> They want to include EPICS in their yocto image for the crate controllers.
>>>>> The host system is a linux-x86_64 system, the target arch linux-arm.
>>>>> 
>>>>> Currently their Yocto recipe fails, because EPICS is build for both host and target arch and some libraries are missing for the host.
>>>>> 
>>>>> Is there a way to build EPICS only for a target architecture?
>>>>> 
>>>>> Best regards,
>>>>> Florian
>>>>> 
>>> -- 
>>> Dr. Florian Feldbauer
>>> 
>>> Ruhr-Universität Bochum
>>> Experimentalphysik I AG
>>> Universitätsstr. 150
>>> Fach-Nr. 125
>>> D-44801 Bochum
>>> 
>>> Office: NB 2/134
>>> Phone:  (+49)234 / 32-23563
>>> Fax:    (+49)234 / 32-14170
>>> https://paluma.ruhr-uni-bochum.de
>>> 
> -- 
> Dr. Florian Feldbauer
> 
> Ruhr-Universität Bochum
> Experimentalphysik I AG
> Universitätsstr. 150
> Fach-Nr. 125
> D-44801 Bochum
> 
> Office: NB 2/134
> Phone:  (+49)234 / 32-23563
> Fax:    (+49)234 / 32-14170
> https://paluma.ruhr-uni-bochum.de
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System