This option enables generic access to platform level
persistent storage via "pstore" filesystem that can
be mounted as /dev/pstore. Only useful if you have
a platform level driver that registers with pstore to
provide the data, so you probably should just go say "Y"
(or "M") to a platform specific persistent store driver
(e.g. ACPI_APEI on X86) which will select this for you.
If you don't have a platform persistent store driver,
say N.

source code:

fs/pstore/