pstore: new filesystem interface to platform persistent storage
Some platforms have a small amount of non-volatile storage that
can be used to store information useful to diagnose the cause of
a system crash. This is the generic part of a file system interface
that presents information from the crash as a series of files in
/dev/pstore. Once the information has been seen, the underlying
storage is freed by deleting the files.
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/Documentation/ABI/testing/pstore b/Documentation/ABI/testing/pstore
new file mode 100644
index 0000000..f1fb2a0
--- /dev/null
+++ b/Documentation/ABI/testing/pstore
@@ -0,0 +1,35 @@
+Where: /dev/pstore/...
+Date: January 2011
+Kernel Version: 2.6.38
+Contact: tony.luck@intel.com
+Description: Generic interface to platform dependent persistent storage.
+
+ Platforms that provide a mechanism to preserve some data
+ across system reboots can register with this driver to
+ provide a generic interface to show records captured in
+ the dying moments. In the case of a panic the last part
+ of the console log is captured, but other interesting
+ data can also be saved.
+
+ # mount -t pstore - /dev/pstore
+
+ $ ls -l /dev/pstore
+ total 0
+ -r--r--r-- 1 root root 7896 Nov 30 15:38 dmesg-erst-1
+
+ Different users of this interface will result in different
+ filename prefixes. Currently two are defined:
+
+ "dmesg" - saved console log
+ "mce" - architecture dependent data from fatal h/w error
+
+ Once the information in a file has been read, removing
+ the file will signal to the underlying persistent storage
+ device that it can reclaim the space for later re-use.
+
+ $ rm /dev/pstore/dmesg-erst-1
+
+ The expectation is that all files in /dev/pstore
+ will be saved elsewhere and erased from persistent store
+ soon after boot to free up space ready for the next
+ catastrophe.