Add SPLIT_KERNEL_DEBUG knob

[emaste]

Summary

PR: 264433

This may not be fully complete (I have not investigated the kernel itself, only modules) but am posting for review of the knob/concept.

[emaste]

Full diff not just src.conf.5

[emaste]

I have not investigated the kernel itself

kernel build never changed, so does not need to be touched here.

CC @bdrewery as he added the setting of MK_KERNEL_SYMBOLS=no in ports 5968fb2d2ff5e. If this D35437 change is going to go in we'll want to set MK_SPLIT_KERNEL_DEBUG=no also.

share/man/man5/src.conf.5

654–656

This is due to conflicting FDT defaults and can be ignored
(this hunk will be manually reverted prior to pushing to main)

[emaste]

Rather, ports 064127e4d8e2e was the original introduction of the functionality.

[emaste]

Include WITHOUT_SPLIT_KERNEL_DEBUG description file in diff

[eugen_grosbein.net]

I've applied the change to stable/13 manually fixing some rejection and tested it. Works like a charm, thank you. Please commit.

[eugen_grosbein.net]

To clarify: I ran make buildkernel && make installkernel having *no* MODULES_WITH_WORLD= in /etc/src.conf
and no DEBUG=

Works as expected matching 12.3 behaviour.

[eugen_grosbein.net]

Corrected previous comment.

[imp]

Thanks for synthesizing this into something simple Ed.