How to run app directly after burning bootloader?

[floatcloud]

Hi, 

I am using NRF52832 and SDK 11

I tried to include DFU function into the device. I merged bootloader (from modified bootloader example), application, softdevice into one HEX file, and use nRFgo Studio to burn the HEX into the device. But after powered on, the device always immediately advertising as "DfuTarg" instead of running the main application. If I use nRFConnect App to connect this "DfuTarg", then I can use OTA to update the application to the device, then it will run the main application with DFU perfectly.

Why is that? Did I miss something?

Thanks

[floatcloud]

Does it have something to do with the bootloader code here:    dfu_start  = app_reset;   ?

Sorry I am not very familiar with the bootloader code.