63 lines · plain
1What: /sys/firmware/opal/elog2Date: Feb 20143Contact: Stewart Smith <stewart@linux.vnet.ibm.com>4Description:5 This directory exposes error log entries retrieved6 through the OPAL firmware interface.7 8 Each error log is identified by a unique ID and will9 exist until explicitly acknowledged to firmware.10 11 Each log entry has a directory in /sys/firmware/opal/elog.12 13 Log entries may be purged by the service processor14 before retrieved by firmware or retrieved/acknowledged by15 Linux if there is no room for more log entries.16 17 In the event that Linux has retrieved the log entries18 but not explicitly acknowledged them to firmware and19 the service processor needs more room for log entries,20 the only remaining copy of a log message may be in21 Linux.22 23 Typically, a user space daemon will monitor for new24 entries, read them out and acknowledge them.25 26 The service processor may be able to store more log27 entries than firmware can, so after you acknowledge28 an event from Linux you may instantly get another one29 from the queue that was generated some time in the past.30 31 The raw log format is a binary format. We currently32 do not parse this at all in kernel, leaving it up to33 user space to solve the problem. In future, we may34 do more parsing in kernel and add more files to make35 it easier for simple user space processes to extract36 more information.37 38 For each log entry (directory), there are the following39 files:40 41 ============== ================================================42 id: An ASCII representation of the ID of the43 error log, in hex - e.g. "0x01".44 45 type: An ASCII representation of the type id and46 description of the type of error log.47 Currently just "0x00 PEL" - platform error log.48 In the future there may be additional types.49 50 raw: A read-only binary file that can be read51 to get the raw log entry. These are52 <16kb, often just hundreds of bytes and53 "average" 2kb.54 55 acknowledge: Writing 'ack' to this file will acknowledge56 the error log to firmware (and in turn57 the service processor, if applicable).58 Shortly after acknowledging it, the log59 entry will be removed from sysfs.60 Reading this file will list the supported61 operations (currently just acknowledge).62 ============== ================================================63