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- 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
- Due to the presence of numerous firmware bugs where removing non-standard
- UEFI variables causes the system firmware to fail to POST, efivarfs
- files that are not well-known standardized variables are created
- as immutable files. This doesn't prevent removal - "chattr -i" will work -
- but it does prevent this kind of failure from being accomplished
- accidentally.
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