Slackware Multiboot: Tricking the installer

November 01, 2017 (Last Modified: December 12, 2018)

The slackware installer setup is self-explanatory, except for multiple boot systems. It looks for an EFI boot partition, formatted FAT 32, and will use the first one it finds. This is a problem if you already have another Linux or Windows installed. I don’t like to share /boot partitions between distros and certainly not with Windows. But there’s a workaround:
```
boot your Slackware iso usb
mount your / partition to /mnt
mkdir /mnt/boot/efi
mount your desired /boot partition to /mnt/boot/efi
```
start the installer setup and go through the first steps including selecting the partitions
BEFORE installing the packages, return to the terminal [ctl]-[alt]-[F2] and see if the slack installer has mounted a /boot/efi partition it shouldn’t have
unmount umount the incorrect /boot/efi partition but leave the correct one mounted
return to the installer [ctl]-[alt]-[F7] and proceed with install - it will use the mounted /boot/efi partition
after installation, correct /etc/fstab so the /boot/efi entry (e.g. sda#) points the one you wanted