What: /sys/firmware/opal/elog Date: Feb 2014 Contact: Stewart Smith Description: This directory exposes error log entries retrieved through the OPAL firmware interface. Each error log is identified by a unique ID and will exist until explicitly acknowledged to firmware. Each log entry has a directory in /sys/firmware/opal/elog. Log entries may be purged by the service processor before retrieved by firmware or retrieved/acknowledged by Linux if there is no room for more log entries. In the event that Linux has retrieved the log entries but not explicitly acknowledged them to firmware and the service processor needs more room for log entries, the only remaining copy of a log message may be in Linux. Typically, a user space daemon will monitor for new entries, read them out and acknowledge them. The service processor may be able to store more log entries than firmware can, so after you acknowledge an event from Linux you may instantly get another one from the queue that was generated some time in the past. The raw log format is a binary format. We currently do not parse this at all in kernel, leaving it up to user space to solve the problem. In future, we may do more parsing in kernel and add more files to make it easier for simple user space processes to extract more information. For each log entry (directory), there are the following files: ============== ================================================ id: An ASCII representation of the ID of the error log, in hex - e.g. "0x01". type: An ASCII representation of the type id and description of the type of error log. Currently just "0x00 PEL" - platform error log. In the future there may be additional types. raw: A read-only binary file that can be read to get the raw log entry. These are <16kb, often just hundreds of bytes and "average" 2kb. acknowledge: Writing 'ack' to this file will acknowledge the error log to firmware (and in turn the service processor, if applicable). Shortly after acknowledging it, the log entry will be removed from sysfs. Reading this file will list the supported operations (currently just acknowledge). ============== ================================================