On 21/08/2026 at 05:25, Carl Karsten wrote:
Can someone point me to a spec or something that defines waht a valid uefi
boot device is?
As far as I know:
- DOS/MBR or GPT partition table.
- Partition #1 with type identifier "EFI System Partition" and FAT12,
FAT16 or FAT32 filesystem depending on the partition size.
- First stage boot loader installed in the partition as
/EFI/BOOT/BOOT$ARCH.EFI (with $ARCH = 'x64' for amd64, 'AA64' for arm64...).
A FAT filesystem in an unpartitioned drive or a FAT partition with a
type identifier other than ESP may work, but no guarantee.
