This just reminds me that I have a real 8088 that I don't know what to do with. Last I knew, it even worked, but it hasn't been turned on in decades so I am not eager to risk it, even if I were to sanity check it for blown capacitors.

https://github.com/jbruchon/elks

ELKS is a Linux subset designed for the 8088, along with a complete toolchain (gcc-ia16). It's also actively maintained and comes with QEMU images and a dockerfile for fast, reproducible builds.

Best to test it on live hardware, it's more rewarding and more fun a toy Unix than xv6.

edit: typos