efi: Add esrt support

Add sysfs files for the EFI System Resource Table (ESRT) under
/sys/firmware/efi/esrt and for each EFI System Resource Entry under
entries/ as a subdir.

The EFI System Resource Table (ESRT) provides a read-only catalog of
system components for which the system accepts firmware upgrades via
UEFI's "Capsule Update" feature.  This module allows userland utilities
to evaluate what firmware updates can be applied to this system, and
potentially arrange for those updates to occur.

The ESRT is described as part of the UEFI specification, in version 2.5
which should be available from http://uefi.org/specifications in early
2015.  If you're a member of the UEFI Forum, information about its
addition to the standard is available as UEFI Mantis 1090.

For some hardware platforms, additional restrictions may be found at
http://msdn.microsoft.com/en-us/library/windows/hardware/jj128256.aspx ,
and additional documentation may be found at
http://download.microsoft.com/download/5/F/5/5F5D16CD-2530-4289-8019-94C6A20BED3C/windows-uefi-firmware-update-platform.docx
.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-firmware-efi-esrt b/Documentation/ABI/testing/sysfs-firmware-efi-esrt
new file mode 100644
index 000000000000..6e431d1a4e79
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-efi-esrt
@@ -0,0 +1,81 @@
+What:		/sys/firmware/efi/esrt/
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	Provides userland access to read the EFI System Resource Table
+		(ESRT), a catalog of firmware for which can be updated with
+		the UEFI UpdateCapsule mechanism described in section 7.5 of
+		the UEFI Standard.
+Users:		fwupdate - https://github.com/rhinstaller/fwupdate
+
+What:		/sys/firmware/efi/esrt/fw_resource_count
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The number of entries in the ESRT
+
+What:		/sys/firmware/efi/esrt/fw_resource_count_max
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The maximum number of entries that /could/ be registered
+		in the allocation the table is currently in.  This is
+		really only useful to the system firmware itself.
+
+What:		/sys/firmware/efi/esrt/fw_resource_version
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The version of the ESRT structure provided by the firmware.
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	Each ESRT entry is identified by a GUID, and each gets a
+		subdirectory under entries/ .
+		example: /sys/firmware/efi/esrt/entries/entry0/
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/fw_type
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	What kind of firmware entry this is:
+		0 - Unknown
+		1 - System Firmware
+		2 - Device Firmware
+		3 - UEFI Driver
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/fw_class
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	This is the entry's guid, and will match the directory name.
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/fw_version
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The version of the firmware currently installed.  This is a
+		32-bit unsigned integer.
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/lowest_supported_fw_version
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The lowest version of the firmware that can be installed.
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/capsule_flags
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	Flags that must be passed to UpdateCapsule()
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/last_attempt_version
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The last firmware version for which an update was attempted.
+
+What:		/sys/firmware/efi/esrt/entries/entry$N/last_attempt_status
+Date:		February 2015
+Contact:	Peter Jones <pjones@redhat.com>
+Description:	The result of the last firmware update attempt for the
+		firmware resource entry.
+		0 - Success
+		1 - Insufficient resources
+		2 - Incorrect version
+		3 - Invalid format
+		4 - Authentication error
+		5 - AC power event
+		6 - Battery power event
+