ipxe -> symantec pxe chain

[NiKiZe]

iPXE does not start payloads with the same base endpoint as the standard EFI pxe stack.
The rationale being that bootloaders, such as BStrap.efi in this case, is to stupid,
iPXE is much better at loading data from http or other places, while the BStrap.efi here probably will try to load files over slow TFTP instead.

I would suggest that the real files and efi executable is loaded by iPXE instead, and then chained into, instead of using their loader.

You might be able to use EFI downgrade as described in http://git.ipxe.org/ipxe.git/commitdiff/a15c0d7