summaryrefslogtreecommitdiffstats
path: root/Documentation/filesystems/efivarfs.txt
diff options
context:
space:
mode:
authorMatt Fleming <matt.fleming@intel.com>2012-10-04 10:57:31 +0200
committerMatt Fleming <matt.fleming@intel.com>2012-10-30 11:39:18 +0100
commite913ca7d16d70b75367ff56a3b201980501d542c (patch)
tree96f0cd6b1672ed329861945e4aa2291b2d399f08 /Documentation/filesystems/efivarfs.txt
parentefi: add efivars kobject to efi sysfs folder (diff)
downloadlinux-e913ca7d16d70b75367ff56a3b201980501d542c.tar.xz
linux-e913ca7d16d70b75367ff56a3b201980501d542c.zip
efivarfs: Add documentation for the EFI variable filesystem
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'Documentation/filesystems/efivarfs.txt')
-rw-r--r--Documentation/filesystems/efivarfs.txt16
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/filesystems/efivarfs.txt b/Documentation/filesystems/efivarfs.txt
new file mode 100644
index 000000000000..c477af086e65
--- /dev/null
+++ b/Documentation/filesystems/efivarfs.txt
@@ -0,0 +1,16 @@
+
+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