https://devzone.nordicsemi.com/f/nordic-q-a/19635/secure-dfu-nrf52I went though steps point here Everything went well. We create bootloader settings hex file base on our application hex file I&#39;m a little confusing now. Should I always create bootloader settings hex file after changing my app, because it&#39;s also probablyen-USTelligent Community 13Tue, 14 Feb 2017 08:18:44 GMThttps://devzone.nordicsemi.com/thread/76416?ContentTypeID=1Tue, 14 Feb 2017 08:18:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bd6e489b-7a5f-4e38-b589-686bd8b6b95eStas<p>Thanks for so detailed answer.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/76415?ContentTypeID=1Mon, 13 Feb 2017 13:10:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:75cca47c-f030-492b-bef9-5e558d4d3629bjorn-spockeli<p>Hi Stas,</p> <p>Q1: No, it is only necessary to generate the settings page and merge it with the bootloader hex-file the first time you flash the bootloader, application and SoftDevice to your nRF5x device.</p> <p>This will ensure that the nRF52 device to starts the application and does not stay in bootloader mode due to the valid application flag not being set and the application crc being incorrect. All subsequent updates of the application will update the bootloader settings page to the correct values corresponding to the new application image.</p> <p>Q2: The easiest way is to add the buttonless feature to an application is to use the experimental_ble_app_buttonless_dfu example as a template and add in the required functions.</p> <p>Q2.1: Yes, it is possible add the same switch-to-the-bootloader functionality with a button press in addition to the buttonless approach.</p> <p>Best regards</p> <p>Bjørn</p><div style="clear:both;"></div>