The generic kernel from slackware-current now has filesystem drivers built in, so it doesn't usually need an initrd any more. (The generic kernel of slackware 15 still needs an initrd.)

Brilliant! But I'm so edgy now, I want to use belt and braces. I can foresee a nightmare a year or so down the line when I am stuck with hardware I can't use any more. I want to find out what's going wrong and fix it while I still feel I can.

Update: Thank God! It isn't me misconfiguring things, it really is the kernel code that's misbehaving on my machine. Even with the official Slackware build, 6.9.0 still halts and buzzes. Incidently tpm.ko is built into this kernel.

Linux-6.4.0 boots with my tpm patch. This is a definite step forward. 6.7.4 still doesn't, so I shall need to do a new bisection. I'm guessing that there is a further problem with the tpm driver, as later kernels have a lot of extra code in this area. Over the next few days I'll work on narrowing it down to two successive releases as I did before, then clone the relevant twig overnight and do a proper bisect. Thank God for the at command!

I'm convinced that the buzz which these later kernels produce is an error signal of some kind. I can't imagine random machine noise producing that perfect V-sign.