Comment by suihkulokki

Power9 servers appear already do this. They have minimal firmware to load the on-rom linux, which then uses userland application (petitboot) to figure out which installer media or already installed linux system you want to kexec() into:

https://sthbrx.github.io/blog/2016/05/13/tell-me-about-petit...

This seems logical, if you are going to run linux, why reimplment all the drivers in UEFI.