[PATCH v6 30/36] powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
From: Hari Bathini <hbathini@linux.ibm.com>
Date: 2019-09-11 16:13:26
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
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: Hari Bathini <hbathini@linux.ibm.com> --- * No changes in v6. Documentation/powerpc/firmware-assisted-dump.rst | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/Documentation/powerpc/firmware-assisted-dump.rst b/Documentation/powerpc/firmware-assisted-dump.rst
index ab578ac..08a9b5e 100644
--- a/Documentation/powerpc/firmware-assisted-dump.rst
+++ b/Documentation/powerpc/firmware-assisted-dump.rst@@ -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: -----------------------