sysfs-firmware-opal-elog 2.3 KB

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  1. What: /sys/firmware/opal/elog
  2. Date: Feb 2014
  3. Contact: Stewart Smith <stewart@linux.vnet.ibm.com>
  4. Description:
  5. This directory exposes error log entries retrieved
  6. through the OPAL firmware interface.
  7. Each error log is identified by a unique ID and will
  8. exist until explicitly acknowledged to firmware.
  9. Each log entry has a directory in /sys/firmware/opal/elog.
  10. Log entries may be purged by the service processor
  11. before retrieved by firmware or retrieved/acknowledged by
  12. Linux if there is no room for more log entries.
  13. In the event that Linux has retrieved the log entries
  14. but not explicitly acknowledged them to firmware and
  15. the service processor needs more room for log entries,
  16. the only remaining copy of a log message may be in
  17. Linux.
  18. Typically, a user space daemon will monitor for new
  19. entries, read them out and acknowledge them.
  20. The service processor may be able to store more log
  21. entries than firmware can, so after you acknowledge
  22. an event from Linux you may instantly get another one
  23. from the queue that was generated some time in the past.
  24. The raw log format is a binary format. We currently
  25. do not parse this at all in kernel, leaving it up to
  26. user space to solve the problem. In future, we may
  27. do more parsing in kernel and add more files to make
  28. it easier for simple user space processes to extract
  29. more information.
  30. For each log entry (directory), there are the following
  31. files:
  32. ============== ================================================
  33. id: An ASCII representation of the ID of the
  34. error log, in hex - e.g. "0x01".
  35. type: An ASCII representation of the type id and
  36. description of the type of error log.
  37. Currently just "0x00 PEL" - platform error log.
  38. In the future there may be additional types.
  39. raw: A read-only binary file that can be read
  40. to get the raw log entry. These are
  41. <16kb, often just hundreds of bytes and
  42. "average" 2kb.
  43. acknowledge: Writing 'ack' to this file will acknowledge
  44. the error log to firmware (and in turn
  45. the service processor, if applicable).
  46. Shortly after acknowledging it, the log
  47. entry will be removed from sysfs.
  48. Reading this file will list the supported
  49. operations (currently just acknowledge).
  50. ============== ================================================