Commit b3bba79d authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

powerpc/fadump: update documentation about option to release opalcore 



With /sys/firmware/opal/core support available on OPAL based machines
and an option to the release memory used by kernel in exporting this
core file, update FADump documentation with these 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/156821382786.5656.13173494907671241231.stgit@hbathini.in.ibm.com
parent 7b1b3b48

Documentation/powerpc/firmware-assisted-dump.rst

+19 −0
Original line number Diff line number Diff line
@@ -110,6 +110,16 @@ 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.



-- On OPAL based machines (PowerNV), if the kernel is build with

   CONFIG_OPAL_CORE=y, OPAL memory at the time of crash is also

   exported as /sys/firmware/opal/core file. This procfs file is

   helpful in debugging OPAL crashes with GDB. The kernel memory

   used for exporting this procfs file can be released by echo'ing

   '1' to /sys/kernel/fadump_release_opalcore node.



   e.g.

     # echo 1 > /sys/kernel/fadump_release_opalcore



Implementation details:

-----------------------
@@ -273,6 +283,15 @@ Here is the list of files under kernel sysfs: 
    enhanced to use this interface to release the memory reserved for

    dump and continue without 2nd reboot.



 /sys/kernel/fadump_release_opalcore



    This file is available only on OPAL based machines when FADump is

    active during capture kernel. This is used to release the memory

    used by the kernel to export /sys/firmware/opal/core file. To

    release this memory, echo '1' to it:



    echo 1  > /sys/kernel/fadump_release_opalcore



Here is the list of files under powerpc debugfs:

(Assuming debugfs is mounted on /sys/kernel/debug directory.)

CRA Git | Maintained and supported by SUSTech CRA and CCSE