EFI native support on amd64

[Alexander Nasonov <alnsn%yandex.ru@localhost>]

Hi,

I see some pieces of EFI in the base (gnu-efi, grub support) but
no complete native support. If I remember correctly, someone worked
on it but I don't have any link to their work. Are there any patches
I can hack on further?

PS I was able to link a hello world amd64 executable. It printed
gibberish, though, presumably because it expected CHAR16. Otherwise,
coding was quite easy given my lack of knowledge in this area.

Alex