[linux] Add CIP Information

[pacoxu]

CIP is something ​super long-term maintenance for kernel.

https://wiki.linuxfoundation.org/civilinfrastructureplatform/start

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[captn3m0]

While this is helpful, do you happen to have more details about CIP? We had a discussion at #3990 earlier, and the main two questions I'd like answered are:

1. How to use CIP kernels. The user-manual mentions Debian a lot, so I'm wondering if there's a way to switch your kernel to the CIP one?
2. What's the CVE parity of the project, compared to other efforts, or via currently supported stable branches. gitlab.com/cip-project/cip-kernel/cip-kernel-sec probably answers it, but it requires a lot of work.

And as mentioned by @BiNZGi in that issue:

We should list these versions with an additional extendedSupport entry and explain the SLTS in the description.

[pacoxu]

https://wiki.linuxfoundation.org/civilinfrastructureplatform/cip-sw-updates

The CIP project provides example operating system images and metadata for a set of reference boards to accelerate the adoption of the CIP open source base layer. These example images are created from the CIP open source base layer by using Linux image build or generation tools such as meta-debian or ISAR.

CIP seems to be a little different with the LTS, and that's why I just add a description to mention the CIP, but not add it to the LTS diagram above.

I prefer to just mention the CIP as it is in the linux foundation official website, but it is maintained in a different place and by different people(not kernel team).

We should list these versions with an additional extendedSupport entry and explain the SLTS in the description.

Agree. This is an additionalExtented Support. We may rephrase the wording here.

[pacoxu]

This may be auguable as https://www.kernel.org/category/releases.html does not mention the CIP release at all.

I just realized that the CIP version is mentioned in the diagram https://endoflife.date/linux.
https://upload.wikimedia.org/wikipedia/en/timeline/aor6fuhg0lk6d4ygitb596a54rl5m8m.png

[captn3m0]

Third party extended support is still support - we already track eoas like this across several products. if it is helpful for the kernel users, we should add it.

My reading of CIP so far is that it is still a WIP, an it is unclear how an existing user can switch to CIP, even if they are on Debian. We can add a mention of CIP, but for most users it will be a source of frustration: Knowing there is a supported kernel version, but they can't use it.

[captn3m0]

I'm marking this as blocked till we figure out some answers for CIP.