Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / ABI / stable / sysfs-firmware-opal-elog

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+What:          /sys/firmware/opal/elog
+Date:          Feb 2014
+Contact:       Stewart Smith <stewart@linux.vnet.ibm.com>
+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 (curently just acknowledge).
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