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