cmdline for enableing core dump

I have imx6ul sbc connector board running kernel version 4.1.39-dey+gf1810a3
Currently the cmdline:
console=ttymxc4 cma=96M mtdparts=gpmi-nand:3m(bootloader), … rootfstype=ubifs rw quiet

I am not sure to add something like crashkernel=50M rootwait etc. to enable core dump for debugging program crashing.

Or some other ways or tools for crashing debugging?

Thank you,


please take a look at this page:
it should answer your question

Hi Leonid,

Thank you for your answer and help.
I have generated a core file, but for imx6ul, how to analyze the core file. It seems to me that it needs gdb executable, but I found no gdb program under sysroots/x86_64. Is there a configuration that needs to be bitbaked?

Best Regards,


I found arm-dey-linux-gnueabi-gdb under the sysroots


Hi David,
Yes, that’s the one.

Hi Leonid,
I found that the binary executable has to be built in debug. If it is release build without debug info, the gdb shows nothing from the core dump file.
Or I missed something.
The debug build makes executable very big, and there no room or space to dump core.
I am not sure there is a workaround.
Thank you,

do not boot from flash, use TFP/NFS instead, then your rootfs will be a folder on your host Ubuntu