It's not that this page is critically outdated or anything. But it is rather old.. I think it could be worth updating the page and including the information from this posting on linuxquestions.org : https://www.linuxquestions.org/questions/slackware-14/grub2-in-slackware-discussion-and-instruction-4175727986/#post6447855

I don't want to update this page, since I don't use UEFI and don't want to start changing the current content and adding the new content in the right places and so fourth. Making it a bit more readable/simple wouldn't hurt either. Here is the content of that post:

Originally Posted by LuckyCyborg View Post Here's a mini-tutorial.

Installing GRUB2

IF you have a hardware using UEFI, you should mount /boot/efi and execute this command: 

grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=Slackware --recheck

Updating the GRUB2 configuration

All you have to do is to execute this command: 

grub-mkconfig -o /boot/grub/grub.cfg

For your convenience in future, you can create this /usr/sbin/update-grub script: 

#!/bin/sh

set -e

exec grub-mkconfig -o /boot/grub/grub.cfg "$@"

And there is time to reboot and enjoy your GRUB2 setup with the generic kernel.

On the future, each time you upgrade the kernel, you should execute this command: 

grub-mkconfig -o /boot/grub/grub.cfg

That's all.