It is free. Get it while it is still free.
QB64. Linux too but I have not tried it on Linux yet.

My old QB would not run on system 7 64 bit.

Many of the memory limitations of the old QB where addressed.

QB is hands down the easiest programming language to learn ever invented.

I suggest practicing with it before you work on the EFI project.
It will build your confidence.

It will have some limitations on direct hard ware access as it must
go through windows.

www.qb64.net

Paul Lamar