[OE-core] do_kernel_configme and defconfig

[chris.laplante at agilent.com]

Hi Bruce,

Thanks for your insights. The defconfig is coming from KBUILD_DEFCONFIG_machinename = “our_defconfig” in our machine conf. I understand that the defconfig is just another configuration fragment, but given that it has its own variable (KBUILD_DEFCONFIG) I guess I was expecting a bit of “magic” out of it; namely, ordering such that the fragment called “defconfig” comes first. Otherwise I don’t really see the point in supporting in-tree defconfig + .scc/cfg fragments, since the former will just wipe out the latter.

That being said, your explanation of the current behavior makes sense, but I think it should be emphasized somewhere in the manual. Care if I submit a documentation patch?

Thanks,
Chris

From: Bruce Ashfield [mailto:bruce.ashfield at gmail.com]
Sent: Friday, May 11, 2018 5:09 PM
To: LAPLANTE,CHRIS (A-Little Falls,ex1) <chris.laplante at agilent.com>
Cc: Patches and discussions about the oe-core layer <openembedded-core at lists.openembedded.org>; SMITH,JARED (A-Little Falls,ex1) <jared.smith at agilent.com>
Subject: Re: [OE-core] do_kernel_configme and defconfig



On Fri, May 11, 2018 at 3:28 PM, Chris Laplante via Openembedded-core <openembedded-core at lists.openembedded.org<mailto:openembedded-core at lists.openembedded.org>> wrote:
OK, I figured out why this happens. This line in kernel-yocto.bbclass:

scc --force -o ${S}/${meta_dir}:cfg,merge,meta ${includes} ${bsp_definition} ${sccs} ${patches} ${KERNEL_FEATURES}

… passes the BSP def before the sccs. In my case, the BSP def is mymachine.scc, and the sccs is the defconfig. So that’s why the defconfig comes after the BSP.

My takeaway is that a BSP plus a defconfig is not a supported use case. Is that correct?

A defconfig isn't magic, it is just another input to the configuration merging. It will be applied as any other fragment. There is some special processing only a defconfig is specified, but otherwise, it is the same. So in this case, whatever it sets would be applied after the BSP definition and would take precedence (last through the gate wins).

If you have a BSP definition, you normally don't have a defconfig. Where is the defconfig coming from in your scenario ? The SRC_URI ? You can just include it from the .scc files to control the order, which is what is expected when you have a BSP definition.

Were you seeing none of your options set ? or something else ?


If so, I think it’s important to add some sanity checking to kernel-yocto.bbclass.


There's really nothing that could be checked, since the intent of the fragments isn't known, and for the most part, defconfigs are the same as any other fragment (from the point of view of the merging).

Bruce

Thanks,
Chris

From: openembedded-core-bounces at lists.openembedded.org<mailto:openembedded-core-bounces at lists.openembedded.org> [mailto:openembedded-core-bounces at lists.openembedded.org<mailto:openembedded-core-bounces at lists.openembedded.org>] On Behalf Of Chris Laplante via Openembedded-core
Sent: Friday, May 11, 2018 2:51 PM
To: openembedded-core at lists.openembedded.org<mailto:openembedded-core at lists.openembedded.org>
Cc: SMITH,JARED (A-Little Falls,ex1) <jared.smith at agilent.com<mailto:jared.smith at agilent.com>>
Subject: [OE-core] do_kernel_configme and defconfig

Hi all,

Is it expected for do_kernel_configme to apply the defconfig last (after configuration fragments introduced by sccs)?

For some reason, in the call to merge_config, “.kernel-meta/configs//./defconfig” is passed last whereas I’d expect it would be first (since that should be the base config). This is causing problems, because config options that my config fragments are setting are getting overridden by the defconfig – it should be the other way around.

For reference, I’m using Rocko and have just updated to the latest commit. We have an in-tree defconfig, and we set KBUILD_DEFCONFIG_machinename appropriately. We are using the separate kernel-meta repository to store kernel metadata. I have KMACHINE_machinename set up so that it finds the correct BSP definition .scc file. Still seem to be missing something, though.

Thanks,
Chris

--
_______________________________________________
Openembedded-core mailing list
Openembedded-core at lists.openembedded.org<mailto:Openembedded-core at lists.openembedded.org>
http://lists.openembedded.org/mailman/listinfo/openembedded-core



--
"Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end"
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openembedded.org/pipermail/openembedded-core/attachments/20180511/dc55cac7/attachment-0002.html>