Hi there,
Yes there is posts and examples here for things like the boot counter (saves the number in NVS and reads it on reboot) I think that’s what you want. I just posted and example in another thread that includes it, Have a look at that code and see if it’s a FIT! 
HTH
GL 
PJ 
What was the build configuration in NRF_SDK You can’t use the system build to make it , The bootloader in Not setup for it. 