Experimental Physics and
Industrial Control System

Gedare Bloom via Core-talk <core-talk at aps.anl.gov> · Fri, 12 Feb 2021 11:37:33 -0700

On Thu, Feb 11, 2021 at 2:24 PM Johnson, Andrew N. <anj at anl.gov> wrote:
>
> Hi Gedare,
>
> On Feb 11, 2021, at 2:28 PM, Gedare Bloom via Core-talk <core-talk at aps.anl.gov> wrote:
>
>
> There's a proposal that was floated 3 years ago and is recirculating
> within the RTEMS development team to consider a long-term stable
> branch of rtems-4.10. I'd like to gather some information about
> possible interest or non-interest from EPICS. The key question is:
> Would you like to include long-term stable 4.10 releases in any
> open/maintained EPICS versions?
>
>
> I can’t speak for other labs, but the APS at Argonne currently has around 100 RTEMS 4.9.2 and 4.10.2 uC5282 systems of several different types in our operational systems. Because of the limited size of that CPU board we don’t know whether those systems could be upgraded to RTEMS-5, and we don’t have the effort available right now to find out. As a result we want future EPICS releases to continue to build and run on RTEMS 4.10, and we have been contributing effort to ensure that EPICS will continue to work on 4.10 after we merge in the RTEMS-5 port. We haven’t needed to build newer RTEMS 4.10.x versions at APS, although I believe some other labs may have been using newer tagged versions.
>
This is good to know. I think I and others will attempt to
characterize the size/resource requirements on 5.1, and I might try to
do a comparison against 4.10. (It is, probably, publishable work for
me so I can put some time into it.) Although the source code
complexity is increasing, we believe the runtime overhead may actually
be shrinking due to better ways to optimize code and system resources.
More on that, later.

(I have also put in an order for uC5282 devices, but waiting to find
out from Arcturus if the development kits are available any longer or
only the SODIMM devices. I might like some assistance to put together
a SODIMM harness for testing, if that is all I can procure. I'll
engage you offline about that if it comes to it.)

> Now speaking as an EPICS Core developer the EPICS CI process on GitHub Actions current runs our built-in unit tests against both 4.9 and 4.10 on i386 under qemu, and for RTEMS-5 we will test against i686 under qemu. We could add other architectures too if they can be made to run under qemu. The RTEMS builds that we use are compiled by Michael Davidsaver – we don’t try to use the latest RTEMS git version and I’m not sure exactly which tags his images were built against.
>
My (University/NSF-funded) team is working with qemu/pc right now as
well, and we will look at other ways to improve qemu-based testing for
EPICS+RTEMS at least for future releases. 4.10-based testing
improvements are not on anyone's roadmap, unless the RTEMS Project
decides to commit to an LTS branch on it.

> I will respond to your other email too…
>
> - Andrew
>
> --
> Complexity comes for free, simplicity you have to work for.
>

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System