efivarfs - a (U)EFI variable filesystem The efivarfs filesystem was created to address the shortcomings of using entries in sysfs to maintain EFI variables. The old sysfs EFI variables code only supported variables of up to 1024 bytes. This limitation existed in version 0.99 of the EFI specification, but was removed before any full releases. Since variables can now be larger than a single page, sysfs isn't the best interface for this. Variables can be created, deleted and modified with the efivarfs filesystem. efivarfs is typically mounted like this, mount -t efivarfs none /sys/firmware/efi/efivars