I have been at it all day trying to make my usb hdd uefi boot. I have read and watched nearly all you have put up, but I can't find anything about being stuck at the uefi shell in virtualbox. It loads fine non-efi VMs both mbr and csm but when I load a efi enabled VM I just get a UEFI Interactive Shell. It tries to load a start.nsh but just goes to Shell> and then nothing.
I am using a windows 7 32 bit aio which should work on both types of "bios". It is sourced from a localized retail dvd so not downloaded. Could it be that the iso I made from it is the problem? I have multiple machines running the 64 bit version from that source also with no problems but that was bios/mbr machines.
Subject UEFI, stuck at shell