I have a bit of a strange use-case, and after searching for 3 days, I am no closer than I started.
So my goal is to install pfSense (freebsd based), onto a Beelink Z83-II. The only problem is that it is a 64bit cpu, for a 64bit OS, with a 32bit efi.
So the normal pfsense usb img file doesn't give boot option.
However, ubuntu 18.04 and freebsd 11.2 both are able to start fine.
They are the 64bit OS, but there usb img contain both a 64 and 32bit version of (grub 2 i believe). So they are able to boot fine, with the 32bit efi, and then proceed to install the 64 bit OS.
My question, and this is where I am having problems, is how can I take the 32bit bootloader of freebsd 11.2 and place it into the pfsense usb img, so I can boot from the installation usb?
I found a lot of how to update grub once installed, but I can't figure out how to change the boot-loader of the install usb.
I'm thinking I need to unpack the img. Change grub, then repack img. However unpacking and changing the usb is many troubles. With iso, I can do it, but not img. And the iso won't boot correctly either ☹.
Any and all help is much appreciated on this strange journey ☺