Switch GRUB2-BLS to GRUB2-EFI for Dual Boot

[Cerunnos]

I’m on a fresh install of slowroll with an existing windows install as dual boot. I found out that grub2-bls requires a much larger partition size than grub2-efi when i ran into problems trying to install nvidia drivers. My efi boot partition is only 360 MB and as far as i know i can’t increase it without bricking my windows install, so i would like to switch to grub2-efi. From what i understand it should be possible to switch but i couldn’t find instructions. Could someone provide me with instructions on how to make this switch?
I’m relatively new to linux so thank you for your patience.

[crestless1624]

There was a similar discussion about this recently, see
here if that helps.

[user_numba_one]

Hello.

I’ve got similiar Question.

But i want to have Triple Boot.
Is that posible?

This is my partitions:

1. In first option i wanted to add GRUB-bls to WIN10 boot (only 100MB and propably thee is grub from Fedora) and this isn’t working - on 90 % (when instaling boot program) of installation there is an error.

2. In second oprion i created
   1GB FAT32 (11) for /boot/efi
   2GB ext4 (8) for /boot
   230,57 ext4 (12) for /root

Also isn’t working.

how to manualy set partitions on disk to Install openSUSE and use as default GRUB of it having all systems in one Grub?

regards

[Cerunnos]

Thank you very much, I believe I got it working based on that. Especially the linked reddit thread by u/JMarcosHP was very helpful. For future reference, the steps I took were:

Install the necessary stuff for grub2-efi:
sudo zypper in grub2 grub2-common grub2-branding-openSUSE grub2-i386-pc grub2-x86_64-efi grub2-snapper-plugin grub2-systemd-sleep-plugin mokutil

Remove grub2-bls:
sudo zypper rm grub2-x86_64-efi-bls

Remove sdbootutil:
sudo zypper rm --clean-deps -y sdbootutil

Use nano to set the variable LOADER_TYPE= to grub2-efi in /etc/sysconfig/bootloader.
In the same file add the following variables at the very bottom (IMPORTANT, without this, the grub menu will fail to load)

SUSE_BTRFS_SNAPSHOT_BOOTING="true"
GRUB_USE_LINUXEFI="true" # Set it to "false" if your system is MBR
GRUB_DISABLE_OS_PROBER="false"
GRUB_ENABLE_CRYPTODISK="n" # Change this to "y" if you use LUKS encryption.

Reinstall all kernel packages with:
sudo zypper in -f kernel-default

Remove the grub2-bls remaining crap from /boot/efi. (use opensuse-tumbleweed for TW)

sudo rm -rf /boot/efi/loader
sudo rm -rf /boot/efi/opensuse-slowroll

Update grub configuration:
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Reinstall the bootloader:

sudo update-bootloader --reinit

# For EFI systems only
sudo shim-install --config-file=/boot/grub2/grub.cfg

Finally, reboot the system.

Now onto my nvidia drivers, hopefully the rest of my OpenSUSE experience will be less painful haha.