nrf51 gcc gnu flashing dfu_bootloader, softdevice s130 and application

Question

Hi 
 I don't understand how to correctly flash all three parts so that the app runs on boot. 
 At the moment if I flash them all the nrf51 (51822) boots to the dfu bootloader. 
 If I use dfu then to load the app. The app will then run ok 
 If I flash just the app and softdevice the app boots ok. 
 I've noticed quite a few questions like this on the forum - but none seem to work 
 If I do flash like this 
 
 s130_nrf51_2.0.0_softdevice.hex 
 bootloader.hex 
 app.hex 
 app_valid_setting_apply.hex 
 
 Then the app runs on boot - the dfu will start but the dfu app download fails 
 Any ideas?

johnofleek · Accepted Answer

The problem was partly cause by me - I was using a raspberry pi to program the target - and also as BLE central listening to target advertising for test purposes. The rpi was physically very close to the target (1") and the dfu BLE central was 1 meter away. This setup seems to cause dfu <-> target comms issues. 
 The solution to the initial programming issue is to use app_valid_setting_apply.hex but I don't understand what this actually does - anyway the following (openocd) sequence successfully programs the target. 
 Program - soft device - add verify to test 
 program s130_nrf51_2.0.0_softdevice.hex 
 program - bootloader 
 program dfu_test_bootloader_b_s130.hex 
 Program - application 
 program app.hex 
 program app_valid_setting_apply.hex