Motherboard: Asrock B660M-ITXac (manual)
I'm trying to boot in legacy mode, but every time it just goes into BIOS. When i enable UEFI mode in the unraid install it works fine.

In the boot options it shows: 'UEFI: USB, Partition 1 ( USB)' as the only option, even though UEFI mode is disabled in the UNRAID install.

 

(settings from my BIOS)

Boot > Fast boot: disabled (manual sais you can't boot from a USB storage device in fast boot)

Advanced > USB configuration > Legacy USB support: enabled (I think this would be the setting to enable legacy boot)

 

None of those settings fixed it though and I couldn't find any other related setting even when searching through the motherboard manual.

Google searches don't help either since there are no answers for my specific motherboard. Any idea how I would be able to fix it?

Let me know if I should supply any other form of information.

You need to enable CSM support on the board, but note that it might not be supported, especially is using the iGPU.

1 hour ago, JorgeB said:

You need to enable CSM support on the board, but note that it might not be supported, especially is using the iGPU.

This is a screenshot from the manual but I get the same response. I don't have an external gpu (only the igpu) so I sadly don't think CSM is an option.

Is there any other way or should I just stick to the UEFI mode?

Why are you trying to avoid UEFI?

5 minutes ago, trurl said:

Why are you trying to avoid UEFI?

I heard that people have trouble with passing through hardware to vms in UEFI mode, also the integrated memtest doesn't work in UEFI mode so i had to download another image from there site and put it on another usb stick. But if those problems are uncommon then I'm totally willing to use it since I don't think there is any other way for me to use legacy mode.

Give this a read. It explains why UEFI mode introduce difficulty to GPU passthrough when there is only 1 GPU in the system. There is a potential work around by adding "video=efifb:off" to syslinux config.