Ramoops/pstore not working on Kernel 4.9.17 and Android 7.1.2

[gsteimle]

Hello,

We have a device with an iMX6 processor running Android 7.1.2 (Nougat) and Linux kernel 4.9.17. We would like to use the ramoops/pstore feature to obtain useful logs related to kernel panics, but it is not working.

We have the following kernel config flags enabled:

CONFIG_PSTORE=y
CONFIG_PSTORE_CONSOLE=y
CONFIG_PSTORE_PMSG=y
CONFIG_PSTORE_RAM=y

We can then induce a kernel panic with the following instructions entered from an adb shell:

echo 1 > /proc/sys/kernel/sysrq
echo c > /proc/sysrq-trigger

But after the device reboots, the folder /sys/fs/pstore is empty

Is there something else we need to do to enable the feature, or some other reason why it doesn't work?

Gary

[Bio_TICFSL]

Hello Gary,

The ramoops Write the kernel panic to RAM, once you reset or poweroff the device is gone. You probably need modify the device tree as mention here:

Ramoops oops/panic logger — The Linux Kernel documentation 

Regards