Booting a legacy-bios-only image on the atomic pi

Hello,

I am currently trying to boot SigIntOs, a pretty new flavor of ubuntu, onto my pi. When I booted it on my windows box, I had to enable legacy bios to get it to be recognized, but it works.

It is my understanding that there is only UEFI support on the atomic pi. Is there a way to put some BIOS firmware on the pi, or, alternatively, make the image compatible?