manually wrap wimboot cpio

[NiKiZe]

there is several reg editors available that can run on *nix so creating BCD files isn't that hard.
For a example of how to create a BCD file without using bcdedit on windows see this (basic) example: https://github.com/NiKiZe/wimboot-bcd/bl...cd_reg.cmd

ipxe has graphics as well (if we are talking background image) there is also password entry and lots more. and it has a scripting language which makes it possible to do almost anything in regards of dynamic menues etc.