Hello Florian,

> Can you force GPT also in 2.?  All disk partitions get removed anyway.
> Arch wiki says MSDOS layout does not work on all EFI systems
> <https://wiki.archlinux.org/index.php/EFI_system_partition#Create_the_partition>.

Well I'm not sure, if someone has an MSDOS partition table with an ESP
partition it wouldn't be a good idea to wipe it.

The attached patch forces GPT if there's no partition table, and will
preserve/create an ESP partition on an MSDOS/EFI setup. I'm testing it
on various machines, seems to work fine.

WDYT?

Thanks,

Mathieu