Register efivars backend for pstore

modulename: efi-pstore.ko

configname: CONFIG_EFI_VARS_PSTORE

Linux Kernel Configuration
└─>Firmware Drivers
└─>EFI (Extensible Firmware Interface) Support
└─>Register efivars backend for pstore
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Say Y here to enable use efivars as a backend to pstore. This
will allow writing console messages, crash dumps, or anything
else supported by pstore to EFI variables.

source code: