What: /sys/firmware/gsmi Date: March 2011 Contact: Mike Waychison Description: Some servers used internally at Google have firmware that provides callback functionality via explicit SMI triggers. Some of the callbacks are similar to those provided by the EFI runtime services page, but due to historical reasons this different entry-point has been used. The gsmi driver implements the kernel's abstraction for these firmware callbacks. Currently, this functionality is limited to handling the system event log and getting access to EFI-style variables stored in nvram. Layout: /sys/firmware/gsmi/vars: This directory has the same layout (and underlying implementation as /sys/firmware/efi/vars. See `Documentation/ABI/*/sysfs-firmware-efi-vars` for more information on how to interact with this structure. /sys/firmware/gsmi/append_to_eventlog - write-only: This file takes a binary blob and passes it onto the firmware to be timestamped and appended to the system eventlog. The binary format is interpreted by the firmware and may change from platform to platform. The only kernel-enforced requirement is that the blob be prefixed with a 32bit host-endian type used as part of the firmware call. /sys/firmware/gsmi/clear_config - write-only: Writing any value to this file will cause the entire firmware configuration to be reset to "factory defaults". Callers should assume that a reboot is required for the configuration to be cleared. /sys/firmware/gsmi/clear_eventlog - write-only: This file is used to clear out a portion/the whole of the system event log. Values written should be values between 1 and 100 inclusive (in ASCII) representing the fraction of the log to clear. Not all platforms support fractional clearing though, and this writes to this file will error out if the firmware doesn't like your submitted fraction. Callers should assume that a reboot is needed for this operation to complete.