Commit 58cf055d authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP 



Kernel config option CONFIG_PRESERVE_FA_DUMP is introduced to ensure
crash data, from previously crash'ed kernel, is preserved. Update
documentation with this details.

Signed-off-by: default avatarHari Bathini <hbathini@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821377195.5656.15840065629705958324.stgit@hbathini.in.ibm.com
parent bec53196

Documentation/powerpc/firmware-assisted-dump.rst

+9 −0
Original line number Diff line number Diff line
@@ -101,6 +101,15 @@ or later firmware versions on PowerNV (OPAL) platform. 
Note that, OPAL firmware exports ibm,opal/dump node when

FADump is supported on PowerNV platform.



On OPAL based machines, system first boots into an intermittent

kernel (referred to as petitboot kernel) before booting into the

capture kernel. This kernel would have minimal kernel and/or

userspace support to process crash data. Such kernel needs to

preserve previously crash'ed kernel's memory for the subsequent

capture kernel boot to process this crash data. Kernel config

option CONFIG_PRESERVE_FA_DUMP has to be enabled on such kernel

to ensure that crash data is preserved to process later.



Implementation details:

-----------------------