[RFC] testing mainline kernel with OpenWrt userland?

[anon27813507]

goal

testing kernel v 5.6 | 5.7 | 5.8 with OpenWrt userland

prerequisites

assume:

• kernel images of above flavours been compiled (whatever features wanted compiled in, no modules)
• kernel partition space is no issue
• kernel image dumped to kernel partition (/boot)

---

questions

1. how to prevent existing kernel modules (from current OpenWrt feeds/installation) from being loaded during boot (prefer not to remove the modules)?
2. will OpenWrt userland package feeds/installation being impacted/impeded by the change of the kernel, if so to what extent and how to remedy?

[Grommish]

Why wouldn't you just alter the include/kernel-version.mk file and build out with the new version? I must be misunderstanding what you're trying to do.

[anon27813507]

not using the OpenWrt toolchain, just compile the kernel and swap it.

[hnyman]

Will not work.
Note that there are 100+ OpenWrt specific patches for generic kernel plus 50+ for each processor target. Plus similarly all kernel options.

Bumping the kernel major version is a major task. If you need to ask about basics, you will not succeed.

First familiarise yourself with the OpenWrt kernel build infra, and you will better understand my answer here.

[mikma]

@hnyman

Note that there are 100+ OpenWrt specific patches for generic kernel plus 50+ for each processor target. Plus similarly all kernel options.

How important are the patches for the x86-64 target? I'm running my OpenWrt routers in LXD on Ubuntu. And I guess Ubuntu has none of Openwrt's kernel patches. What problems can I expect?

[anon27813507]

@hnyman

Will not work.

Which part? The kernel surely will boot, if correctly configured (and the target being supported by the kernel - which is a given).

---

@hnyman

If you need to ask about basics, you will not succeed.

I did not ask of how to compile the kernel for a given target, just two questions which are unrelated to

@hnyman

the OpenWrt kernel build infra

Say the second question I can find out by testing and see what userland may not be working but would appreciate to know

@anon27813507

how to prevent existing kernel modules (from current OpenWrt feeds/installation) from being loaded during boot (prefer not to remove the modules)?

[Borromini]

@anon27813507

how to prevent existing kernel modules (from current OpenWrt feeds/installation) from being loaded during boot (prefer not to remove the modules)?

Easy peasy. Put them all on the blacklist.

But would you really want that? Better just strip the modules then. There's probably also a box to untick in the kernel configuration to enable module loading. Untick it, recompile (make sure everything you need is in), and you're golden.

[anon27813507]

@Borromini

There's probably also a box to untick in the kernel configuration to enable module loading.

Right you are, missed it...