Originally Posted by Launfal

Thanks all for the input, but RC's command in post #2 worked a treat. I booted into the old generic-kernel, created the new initrd.gz, copied it to /boot/efi/EFI/Slackware, copied over the new generic-kernel, and I was back in business.

I don't know why what I tried the first time didn't work, as I still think it should have, but now that I have a process that works, I'm not going to sweat it, so I marked this thread solved.

I did download a new current image with the 4.4.9 kernel and installed it in another partition, and I can boot from that huge kernel, so apparently the installer is doing something that I didn't. I'm going to have to take a look at that code and see if I can find what it's doing that I didn't.

Thanks again for the replies.