A robust mechanism to get reliable kernel crash dump with
assistance from firmware. This approach does not use kexec,
instead firmware assists in booting the capture kernel
while preserving memory contents. Firmware-assisted dump
is meant to be a kdump replacement offering robustness and
speed not possible without system firmware assistance.

If unsure, say "y". Only special kernels like petitboot may
need to say "N" here.

source code:

arch/powerpc/platforms/powernv/opal-fadump.c