efi: Add support for a UEFI variable filesystem
The existing EFI variables code only supports 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. So, instead, let's add a filesystem. Variables can be read, written and created, with the first 4 bytes of each variable representing its UEFI attributes. The create() method doesn't actually commit to flash since zero-length variables can't exist per-spec. Updates from Jeremy Kerr <jeremy.kerr@canonical.com>. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Showing
This diff is collapsed.
Please register or sign in to comment