I have a very rough draft of patches that implement this strategy on
the 'experiemntal/efi-memmap' branch in the EFI tree if anyone is
curious and wants to take a look. The series will be sent out soon.

I wouldn't necessarily try running them or anything as there's a few
things that I know are broken; ia64 build, EFI mixed mode boot,
probably arm64 regressions.

Matt, I tried :). I see a build warning about print phys_addr_t without
%pa anotation and booting with ioremap error messages about slot not found
, and ioremap region leak messages.

Looking forward to your formal posts.

Thanks
Dave