1 2efivarfs - a (U)EFI variable filesystem 3 4The efivarfs filesystem was created to address the shortcomings of 5using entries in sysfs to maintain EFI variables. The old sysfs EFI 6variables code only supported variables of up to 1024 bytes. This 7limitation existed in version 0.99 of the EFI specification, but was 8removed before any full releases. Since variables can now be larger 9than a single page, sysfs isn't the best interface for this. 10 11Variables can be created, deleted and modified with the efivarfs 12filesystem. 13 14efivarfs is typically mounted like this, 15 16 mount -t efivarfs none /sys/firmware/efi/efivars 17 18Due to the presence of numerous firmware bugs where removing non-standard 19UEFI variables causes the system firmware to fail to POST, efivarfs 20files that are not well-known standardized variables are created 21as immutable files. This doesn't prevent removal - "chattr -i" will work - 22but it does prevent this kind of failure from being accomplished 23accidentally. 24