Although the EFI specification enforces support for FAT ESP, it's free
for EFI implementations to implement support for ESPs with other formats
(e.g. ext4, ntfs, etc), and at least U-Boot EFI will support ext4 ESP if
U-Boot is built with ext4 support. In some situations a GRUB installation
on such a non-FAT ESP could be useful (e.g. a NTFS-based USB disk that
can dual boot a Windows installation media and a Linux LiveCD).
As this is advanced and implementation-dependent behavior, let grub-install
allow this kind of installation, but only when --force is specified.
Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
3aec085410