how to enable the ramoops/pstore on imx8mq evk

[94393400]

Hello,

Our device with an iMX8mq evk processor running Android 9.0  and Linux version 4.14.98-07257.

We would like to use the ramoops/pstore feature to obtain useful logs related to kernel panics, but it is not working.

In arch/arm64/configs/kwe1901_defconfig , We have the following changes:

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

and in the arch/arm64/boot/dts/freescale/kwe1901.dtsi , we add 

+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ranges;
+
+ ramoops@8f000000 {
+ compatible = "ramoops";
+ reg = <0 0x8f000000 0 0x100000>;
+ record-size = <0x4000>;
+ console-size = <0x4000>;
+ };
+ };

After that we can trace 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

Does anyone enabled this function?

[savedstesen]

I did follow the guide here and I'm now able to see kernel panics in the /sys/fs/pstore/ folder. Running on a imx8mq running Android 9 with these kernel settings: 

zcat /proc/config.gz |grep PSTORE
CONFIG_PSTORE=y
CONFIG_PSTORE_ZLIB_COMPRESS=y
# CONFIG_PSTORE_LZO_COMPRESS is not set
# CONFIG_PSTORE_LZ4_COMPRESS is not set
CONFIG_PSTORE_CONSOLE=y
CONFIG_PSTORE_PMSG=y
CONFIG_PSTORE_RAM=y

[savedstesen]

Are there any other options for recording logs across crashes / reboots. We would like to be able to get this as we are seeing crashes sometimes. 

[b36401]

Unfortunately our BSP cannot support warm reboot. So ramoops is not supported.
Sorry for the inconvenience.

[savedstesen]

@b36401 Are there any other options for recording logs across crashes / reboots. We would like to be able to get this as we are seeing crashes sometimes.