For user space? No you can definitely do a stage 0 build which depends only on about 364 bytes of x86_64 binary (though ironically I haven't managed to get this to work for me yet).
The liability is EFI underneath that, and the Intel ring -1 stuff (which we should be mandating is open source).
The liability is EFI underneath that, and the Intel ring -1 stuff (which we should be mandating is open source).