[linux-2.6-block.git] / Documentation / filesystems / efivarfs.txt


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
Commit	Line	Data
e913ca7d MF	1
	2	efivarfs - a (U)EFI variable filesystem
	3
	4	The efivarfs filesystem was created to address the shortcomings of
	5	using entries in sysfs to maintain EFI variables. The old sysfs EFI
	6	variables code only supported variables of up to 1024 bytes. This
	7	limitation existed in version 0.99 of the EFI specification, but was
	8	removed before any full releases. Since variables can now be larger
	9	than a single page, sysfs isn't the best interface for this.
	10
	11	Variables can be created, deleted and modified with the efivarfs
	12	filesystem.
	13
	14	efivarfs is typically mounted like this,
	15
	16	mount -t efivarfs none /sys/firmware/efi/efivars