Do you get the same error when you boot in efi mode?

"Slackware" is only listed as an EFI device unlike the CDROM which can be EFI or legacy.

Perhap I should call it GPT instead of BIOS now.

Yesterday evening I had a breakthrough. I could boot my Slackware 14.1 for the first time from grub2 shell on the installation disk.

grub> linux (hd0,3)/boot/vmlinuz-huge-3.10.17 root=/dev/sda3
grub> boot

It provided /sys/firmware/efi and mounted sda1 on /boot/efi.
Loggin and startx all seamed to work.

This evening I will try once again with eliloconfig this time from a running system.

John

Just an update on this one.
I was wrong about it not booting from a USB stick.
It is just that it does not appear in the boot menu until it is made.
It needed a bit of Kernel compiling though to work:-

CONFIG_RELOCATABLE[=y]

Otherwise the same message as #13 "Please update your Kernel" would appear.

While I can boot from the stick even the new kernel would not boot from the EFI partition.

I tried to install grub2 as above.
It put up another entry in the boot menu "Slackware 14.1" but this would not boot.
It is detected by the Slackware 14.1 installation disk and can be booted from there.

I am responding on this machine now.

John

esp standard specify a fat filesystem
UEFI system partition.