More-or-less bog standard amd64 with amd graphics? Assuming the generic AMD video drivers work FreeBSD should be able to get to a graphical UI out of the box. Might not have controller or gyro drivers, but a keyboard and mouse should work fine.
Now I have a project. Thanks, Droechai…
… no. I was dead serious about trying FreeBSD on the Steamdeck. FreeBSD supports almost all mainstream hardware you’d see on a normal desktop. Figured it’d be similar for the steamdeck. So now my weekend project is to try out booting FreeBSD 16 off a USB stick on my steamdeck.
After a small amount of duckduckgoing I found that it somewhat works already. GPU hardware is detected but can’t initialize. That’s a reasonable starting point for someone like me who isn’t afraid of kernel-level code :/