cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sysfs-firmware-gsmi (2064B)


      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.