Dual boot OpenBSD UEFI with Linux

[HopingStar]

Not sure how to create Grub menuentry for it. Is there anyone here used to dual boot UEFI OpenBSD with Linux?

[HopingStar]

I end up using efibootmgr to generate bootloader for it. This is the command I use

efibootmgr -c -p 1 -d /dev/nvme0n1p4 -L OpenBSD -l /EFI/Boot/bootx64.efi

Ah, no need grub or rEFInd anymore

[Head_on_a_Stick]

OpenBSD's .efi loader should not need an NVRAM entry.

I think you should have just deleted any unused NVRAM boot entries, they were probably preventing /EFI/Boot/bootx64.efi from starting.

Use this to remove superfluous boot entries:

efibootmgr -b xxxx -B

Replace xxxx with the actual boot number, which can be found by examining the plain efibootmgr output.

EDIT: and this will generate a GRUB entry:

menuentry 'OpenBSD' {
   search.fs_uuid $uuid
   chainloader /EFI/Boot/bootx64.efi
}

Replace $uuid with the actual UUID of the EFI system partition (ie, the one containing bootx64.efi).

[hd77]

Originally Posted by Head_on_a_Stick

OpenBSD's .efi loader should not need an NVRAM entry.

I think you should have just deleted any unused NVRAM boot entries, they were probably preventing /EFI/Boot/bootx64.efi from starting.

Use this to remove superfluous boot entries:

efibootmgr -b xxxx -B

Replace xxxx with the actual boot number, which can be found by examining the plain efibootmgr output.

EDIT: and this will generate a GRUB entry:

menuentry 'OpenBSD' {
   search.fs_uuid $uuid
   chainloader /EFI/Boot/bootx64.efi
}

Replace $uuid with the actual UUID of the EFI system partition (ie, the one containing bootx64.efi).

yep, openbsd can be added with a openbsd partition (whom will be used as an aera for all slices) on the disk. I use tri/quadri boot with win/lmde by grub.

however, it's recommended to have also the bsd.rd within the 40_custom of grub.
Unfortunately, I dont have it on my laptop right now (bios, like others), but I did it on several efi laptops.

[shep]

As a caution, Redhat based distributions use /boot/efi/BOOTX64.EFI as their default location. This is also the default for OpenBSD and will result in Grub booting OpenBSD instead of Centos/RHEL/etc....
If you move OpenBSD location, as suggested in this thread, it will function but there will be an error generating the sha256 sum for the unique kernel. OpenBSD looks for /boot/efi/BOOTX64.EFI to update the sha256 sum and will fail if it is in a different location. OpenBSD will still run but not have a unique kernel with every boot.

Debian based derivatives and Arch Linux do not have this problem and the unique kernel checksum will work if you use /boot/efi/BOOTX64.EFI.

[Head_on_a_Stick]

Originally Posted by shep

Debian based derivatives and Arch Linux do not have this problem and the unique kernel checksum will work if you use /boot/efi/BOOTX64.EFI.

Arch will overwrite bootx64.efi if systemd-boot is employed. There doesn't seem to be an option to prevent systemd doing this, which is a shame.

Debian will overwrite bootx64.efi if the "force installation to removable loader location" (force_efi_extra_removable) debconf option for GRUB is used.