Kdump + Crash in I.MX

[#1]

Here is a summary including kdump + crash porting in i.mx, the tool is very useful in crash issue.

Overview

• What is Kdump + Crash
• Preconditions
  • kernel
  • kexec
• Step actions
• Crash tool
• Analysis of use cases

Besides that, I summary the dumper tools including kdump and pstore, the respective patches shown as below:

Kdump:

Customer can apply below patch in config and cmdline, which has been confirmed on linux os. As memory is very precious to android, so kdump is not worth adopting.

Config:

       First kernel:

      CONFIG_KEXEC=y

      CONFIG_SYSFS=y

      CONFIG_DEBUG_INFO=Y

       Capture kernel:

      CONFIG_CRASH_DUMP=y

      CONFIG_PROC_VMCORE=y

Cmdline:

       crashkernel=512M

Pstore:

Customer can apply below patch in config and dts showing as below, which has been confirmed on linux and android os.

Config:

CONFIG_PSTORE_PMSG=y

Dts:

+               ramoops@0x91f00000 {

+                       compatible = "ramoops";

+                       reg = <0 0x91f00000 0 0x00100000>;

+                       record-size     = <0x00020000>;

+                       console-size    = <0x00020000>;

+                       ftrace-size     = <0x00020000>;

+                       pmsg-size       = <0x00020000>;

+               };

+

                decoder_boot: decoder-boot@84000000 {

                        reg = <0 0x84000000 0 0x2000000>;

                        no-map;

Reproduce steps

1. Reboot the system by enter below command:

      $ reboot

2. Check the related log by enter below command:

      $ ls /sys/fs/pstore/

         console-ramoops-0 pmsg-ramoops-0

[shiva_bhargav_y]

Dts:

+               ramoops@0x91f00000 {

+                       compatible = "ramoops";

+                       reg = <0 0x91f00000 0 0x00100000>;

+                       record-size     = <0x00020000>;

+                       console-size    = <0x00020000>;

+                       ftrace-size     = <0x00020000>;

+                       pmsg-size       = <0x00020000>;

+               };

+

                decoder_boot: decoder-boot@84000000 {

                        reg = <0 0x84000000 0 0x2000000>;

                        no-map;

where exactly I have to add lines?