Gigabyte Dual BIOS H87 vs Grub

[vespaman]

I'm failing to get my new computer up - I simply copied my old setup onto a new SSD, and all works just fine as long as I boot with SystemRescue USB stick, and selecting boot kernel from disk.

New computer is H87 with latest firmware.

I am failing to get grub2 onto the SSD, various error messages. I have read that Gigabytes dual bios feature is a problem, should have read that part before purchasing the new MB..
At the moment the disks are non-gpt, two partitions - boot and root.
It seams that grub2-install wants to go UEFI, while my partions are not.

It also seams that I need UEFI active to boot SystemRescueCD, otherwise I do not get going.
Without System rescue, I don't get the menu, screen is black, apart from an blinking underscore in the top left corner.

Anyway, I guess I need to erase the disks and start over, but how - with what settings? EFI or not, GTP or not. This is so confusing and time consuming...

Any suggestions welcome.

[Anon-E-moose]

I would try turning off uefi secure boot in the bios and see if it won't work.

Disclaimer:
I don't use gigabyte, I do have an asus board and it lets me disable uefi and treat everything the old way.
_________________
PRIME x570-pro, 3700x, 6.1 zen kernel
gcc 13, profile 17.0 (custom bare multilib), openrc, wayland

[vespaman]

Thanks, your suggestion put me on a working track in the end - I was able to boot systemrescue as a non-efi media, and when booted, I coud install grub2 onto the SSD.
So, basically I'm on non-efi, non gpt using grub2.

I'm still confused about all the options, but I got it to work after a few trials. Now I need to tidy up the testing-mess I have in front of me...