On systems where enumerating the BootOrder variable (or other related variables) fails, efibootmgr -c will silently create an empty boot order list without first confirming this with the user.
In the best case, this will wipe all entries from the existing boot order list. In the worst case, the resulting BootXXXX entry will overwrite preexisting "reserved" entries and emptying the BootOrder list will make the one-time boot menu useless.
Under unknown conditions (for example when missing variables that should be present on an EFI-compliant system; efibootmgr read operations correctly recognize this as "No BootOrder is set; firmware will attempt recovery"), efibootmgr should only proceed with extreme caution, ideally not at all unless the user signed off on that (--force?), and instead report a fatal error.
On systems where enumerating the
BootOrdervariable (or other related variables) fails,efibootmgr -cwill silently create an empty boot order list without first confirming this with the user.In the best case, this will wipe all entries from the existing boot order list. In the worst case, the resulting
BootXXXXentry will overwrite preexisting "reserved" entries and emptying theBootOrderlist will make the one-time boot menu useless.Under unknown conditions (for example when missing variables that should be present on an EFI-compliant system;
efibootmgrread operations correctly recognize this as"No BootOrder is set; firmware will attempt recovery"),efibootmgrshould only proceed with extreme caution, ideally not at all unless the user signed off on that (--force?), and instead report a fatal error.