sysfs-firmware-gsmi 2.0 KB

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