I guess I misunderstood your request. This[1] and this[2] should be what you are looking for.

[1] https://doc.coreboot.org/security/vboot/index.html

[2] https://github.com/tianocore/edk2

I found no installable code for Secure Boot itself in your links.

That wasn't what you asked for, and I've given you more than enough links for you to find your way to installing it if you wanted to play with it.

If you want something that will hold your hand a little more, then one of the downstream projects might be a better fit.

I'm satisfied I've backed up my points though.

>> I found no installable code for Secure Boot itself in your links.

> That wasn't what you asked for

Here's a quote from my earlier comment:

>> Can I compile coreboot with Secure Boot from source and reflash my UEFI/BIOS with it?

I don't see how I could formulate it better. You seem to evade the actual answer. I'll continue to think this is impossible.

I'm not avoiding the answer, and I've answered your question more than adequately. It seems you want hand holding each step along the way. Are you perhaps unaware that the coreboot implementation is called verified boot rather than secure boot?

I've shown it's possible to flash hardware and have an entirely open source and auditable secure boot implementation which is better than your current solution in a number of ways. That was all I had a burden to prove, and I've met it.

If you want further help or convincing, I'd suggest interacting with an AI to get answers to your questions.