[SOLVED] Proxmox uses GRUB instead of UEFI bootloader on UEFI compatible system

[alirx]

Greetings!
As far as I know disabling CSM should lead to installation in UEFI mode, yet I am still seeing GRUB during boot. What's weird, that efibootmgr -v reports that Proxmox were booted in UEFI mode.

root@atlantis:~# efibootmgr -v
BootCurrent: 000C
Timeout: 1 seconds
BootOrder: 000C,0001
Boot0001  proxmox       HD(2,GPT,06bbd6ca-6c11-4861-a01a-ded5b7d9751f,0x800,0x200000)/File(\EFI\PROXMOX\GRUBX64.EFI)
Boot000C* UEFI OS       HD(2,GPT,06bbd6ca-6c11-4861-a01a-ded5b7d9751f,0x800,0x200000)/File(\EFI\BOOT\BOOTX64.EFI)..BO

I've tried to fix UEFI boot as in this guide on Proxmox forums, but no success.

root@atlantis:~# pve-efiboot-tool init /dev/sdc2
Re-executing '/usr/sbin/pve-efiboot-tool' in new private mount namespace..
UUID="5939-CAC3" SIZE="1073741824" FSTYPE="vfat" PARTTYPE="c12a7328-f81f-11d2-ba4b-00a0c93ec93b" PKNAME="sdc" MOUNTPOINT="/boot/efi"
E: '/dev/sdc2' is mounted on '/boot/efi' - exiting.
root@atlantis:~# pve-efiboot-tool refresh
Running hook script 'proxmox-auto-removal'..
Running hook script 'zz-proxmox-boot'..
Re-executing '/etc/kernel/postinst.d/zz-proxmox-boot' in new private mount namespace..
No /etc/kernel/proxmox-boot-uuids found, skipping ESP sync.

Initial thing I was trying to do was PCI-E passthrough, and methods of setting this up are different for UEFI and GRUB. I did UEFI-steps and there were no effect, which led me to this confusion. Also tried reinstalling Proxmox, got the same results.

Is that an intended behavior and should I bother fixing it or just roll with GRUB?

Hardware config:

Boot device: single SATA SSD, plugged into a motherboard​

CPU: Ryzen 5700X​

MoBo: Asrock B550 Phantom Gaming 4​

GPU: Gigabyte Arc A380​

SATA controller: ASM1166 (M2 to 6xSATA)​

NIC: Intel i-225v​

BIOS settings:

CSM (legacy) mode disabled, secure boot disabled, UEFI boot device set as 1st.​

Proxmox ISO: 8.0.2 from USB stick (burned with etcher).

 

[leesteken]

As far as I know disabling CSM should lead to installation in UEFI mode, yet I am still seeing GRUB during boot. What's weird, that efibootmgr -v reports that Proxmox were booted in UEFI mode.

According to the Proxmox manual: "For EFI Systems installed with ZFS as the root filesystem systemd-boot is used. All other deployments use the standard grub bootloader".
If you did not install Proxmox on ZFS, it's normal that GRUB is used for booting in UEFI mode.

 

[alirx]

Rookie mistake by me. Thank you for your answer, @leesteken , appreciate it!

 

[promoxer]

I'm facing the same issue: CSM disabled, Secure Boot enabled, installed PVE8 onto ZFS, yet I ended up with GRUB. And after adding a 2nd drive to mirror my rpool, that 2nd drive can't boot... https://forum.proxmox.com/threads/m...-on-mirrored-zfs-bootable.138731/#post-619376