1What:		/sys/firmware/gsmi
2Date:		March 2011
3Contact:	Mike Waychison <mikew@google.com>
4Description:
5		Some servers used internally at Google have firmware
6		that provides callback functionality via explicit SMI
7		triggers.  Some of the callbacks are similar to those
8		provided by the EFI runtime services page, but due to
9		historical reasons this different entry-point has been
10		used.
11
12		The gsmi driver implements the kernel's abstraction for
13		these firmware callbacks.  Currently, this functionality
14		is limited to handling the system event log and getting
15		access to EFI-style variables stored in nvram.
16
17		Layout:
18
19		/sys/firmware/gsmi/vars:
20
21			This directory has the same layout (and
22			underlying implementation as /sys/firmware/efi/vars.
23			See Documentation/ABI/*/sysfs-firmware-efi-vars
24			for more information on how to interact with
25			this structure.
26
27		/sys/firmware/gsmi/append_to_eventlog - write-only:
28
29			This file takes a binary blob and passes it onto
30			the firmware to be timestamped and appended to
31			the system eventlog.  The binary format is
32			interpreted by the firmware and may change from
33			platform to platform.  The only kernel-enforced
34			requirement is that the blob be prefixed with a
35			32bit host-endian type used as part of the
36			firmware call.
37
38		/sys/firmware/gsmi/clear_config - write-only:
39
40			Writing any value to this file will cause the
41			entire firmware configuration to be reset to
42			"factory defaults".  Callers should assume that
43			a reboot is required for the configuration to be
44			cleared.
45
46		/sys/firmware/gsmi/clear_eventlog - write-only:
47
48			This file is used to clear out a portion/the
49			whole of the system event log.  Values written
50			should be values between 1 and 100 inclusive (in
51			ASCII) representing the fraction of the log to
52			clear.  Not all platforms support fractional
53			clearing though, and this writes to this file
54			will error out if the firmware doesn't like your
55			submitted fraction.
56
57			Callers should assume that a reboot is needed
58			for this operation to complete.
59