[RFC] status of [meta-]xenomai for Yocto
henning.schild at siemens.com
Wed May 5 11:32:49 CEST 2021
Am Wed, 5 May 2021 10:19:50 +0200
schrieb Stefano Babic <sbabic at denx.de>:
> Hi Philippe, Jan, Henning,
> On 03.05.21 19:30, Jan Kiszka via Xenomai wrote:
> > On 03.05.21 19:16, Henning Schild via Xenomai wrote:
> >> We have xenomai-images kind of maintained under the umbrella of the
> >> project. But that is Isar and Yocto sure has its place as well. I
> >> have also seen buildroot layers which include xenomai.
> >> Such integration systems tend to cause a lot of work. A project
> >> like xenomai probably wants to be "very close" to one of them to
> >> allow continous testing. We have that internally based on Isar and
> >> i think Intel might be going the same way.
> >> Not against the idea, but also not convinced.
> > Was about to express the same concern: Who will test that those
> > preintegrations still work, produce reasonable results? If people
> > stand up and say, "hey, I'm doing that anyway already, will take
> > care of this!", then this could work.
> I had to integrate a couple of time Xenomai in a Yocto build and I
> had thought about if it is worth to start a "meta-xemnomai". But
> after that, supporting Xenomai in Yocto means two main things:
> - add support for Xenomai libs and tools. Well, this is a single
> recipe (at least in my build).
> - patch the kernel running scripts/prepare-kernel.sh.
> And as we can use just LTS kernel, the second one means to add a new
> provider for kernel, let's say a linux-xenomai recipe.
> But then, that's all. I do not know if this it is enough to add an
> own meta-xenomai and to maintain it.
If you want to call it maintained you need to have kernel configs for
boards, and test those boards regularly ... at least with smokey. That
is where the real work starts, as pointed out by jan.
Not doing so will just mean a rather disappointing offering that might
in fact harm the project.
> Could be an alternative path to try to push the required recipes
> (kernel+libs) to OE-Core, exactly as it was done by Preemp-rt ?
> Recipes are then part of a standard layer, and I see as advantage
> that they can be shown by much more people and could help to
> advertise Xenomai.
> Best regards,
> > And then the next aspect would be how to make generic assets like
> > kernel configurations and integration reusable for xenomai-images,
> > and vice versa.
> > Jan
> >> regards,
> >> Henning
> >> Am Mon, 3 May 2021 18:58:49 +0200
> >> schrieb Philippe Gerum via Xenomai <xenomai at xenomai.org>:
> >>> I'd like to discuss the current status of what exists, what might
> >>> be planned regarding a meta layer which would/does provide
> >>> support for Xenomai-enabled kernels. This could be a topic raised
> >>> during the next community meeting.
> >>> I can see a couple of options floating around on the net, all
> >>> dedicated to specific hardware it seems, some/all extending their
> >>> support up to the rootfs image.
> >>> Would it be possible to conceive such support as a meta-bsp layer
> >>> instead, implementing a new kernel type, one that could be
> >>> included in bbconf settings without imposing anything about the
> >>> image to be produced? Something which could be extended to cover
> >>> Xenomai 4/EVL at some point as well.
> >>> It would be nice to discuss ideas around the general topic of
> >>> having a reference meta layer for Xenomai in the most flexible
> >>> way. Whether it already exists, or not.
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