redhat/configs: automotive: stop disabling RHEL modules

ernunesrequested to merge
ernunes/kernel-centos-stream-9:main-automotive-undisable-modules into main-automotive

JIRA: https://issues.redhat.com/browse/RHEL-109755

Upstream Status: RHEL-Only

This commit removes most module disables from the automotive config, for the modules that are already enabled in RHEL. It does not enable any module that is not coming from the RHEL config. It also does not aim to enable any major built-in features which are not modules and that were previously purposedly disabled to reduce validation scope for functional safety.

This is done by generating a comparison between the current RHEL config and the corresponding automotive config, iterating through modules that were enabled in RHEL, and removing the forced disable from the automotive config. A few outliers are module configs that select some other option which cascades into other things getting enabled, in that case the module remains disabled to avoid more things getting enabled.

The proposed benefits of this approach are:

  • Reduce the delta between the automotive config and the RHEL config. The automotive kernel is claimed to be based on the RHEL kernel, but then it goes and diverges from RHEL in thousands of configs.
  • Reduce maintenance burden. Often when some new module is enabled in RHEL, due to the vastly divergence of the automotive config, it is unclear if that module should remain enabled in the automotive config or not, and that increases the maintenance cost. At least for modules, with this we can maintain a policy of inheriting modules from RHEL by default.
  • There has been a very loose policy of what can actually be enabled in rhe automotive config. The result so far is that the config is very arbitrary and things get slowly re-enabled as users hit missing modules. With this, we can set the expectation that modules are available for development if they were in RHEL.
  • This aims to have no impact on the set of built-in options for the kernel and should not enable any major features that were disabled before due for a safety argumentation. So it should not impact that, but still reduce the divergence from the RHEL kernel.
  • We do not have to actually ship these additional modules in any automotive images or include them in initramfs. We can control whether these get included in images later on. But there is still at least an option for users to include the modules if they have been built.

Signed-off-by: Erico Nunes ernunes@redhat.com

Edited by ernunes

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