Building a memstick that boots on Legacy and UEFI systems

Barney · Oct 19, 2023

I have a script that builds a memstick for an installer, and I've modified it to build a UEFI loader, but I can't find any documentation on how to make one that boots on both (like the freebsd installer).

smithi · Oct 21, 2023

Barney said:
I have a script that builds a memstick for an installer, and I've modified it to build a UEFI loader, but I can't find any documentation on how to make one that boots on both (like the freebsd installer).

You may have to dive into make-memstick.sh and mkisoimages.sh in /usr/src/release/${arch}/ where arch=amd64 (etc).

Barney · Oct 21, 2023

smithi said:
You may have to dive into make-memstick.sh and mkisoimages.sh in /usr/src/release/${arch}/ where arch=amd64 (etc).

Actually, simply using the bootx64.efi file from the installer made it work. The file is different than any in the distribution, so they must have done something custom. Not sure why the default loader.efi would be a subset of a more useful one.