Indeed, as you suspected, I came back to my machine to a bunch of hash mismatch errors so this patch is not the right way to go about this.

There definitely exists an issue and the reason I came across it was by following the hello-mod recipe in meta-skeleton.

KBUILD_EXTRA_SYMBOLS is passed to make and is just a list of filepath(s) to the depended on module(s) Module.symvers file needed by the module which has the dependency to build successfully.

I will have a think about a better solution.

Cheers,

Charlie