Bootloader is not jumping to application

[Sridhar Jonnavittula]

1. Did secure BLE DFU first time for hrs app, BL jump to hrs app

2. Did secure BLE DFU second time for hts app, BL jump to hts app

3. Did nrfjprog HID keyboard app and IAR , in both cases, BL is not jumping to HID KB and stays in BL DFU target mode

Why in third case bootloader is not starting application or why HID keyboard application is not showing up as Nordic_keyboard?

Can anybody please answer?

Thanks in advance!

[bjorn-spockeli]

Case 3: Do you mean that you're flashing the ble_app_hids_keyboard application, the bootloader example and the S140 SoftDevice to the nRF52840 DK using nrfjprog?

If that is the case you need to generate the bootloader settings page hex using nrfutil in order to tell the bootloader that there is a valid application in flash. See Generating and displaying bootloader settings. 

Best regards

Bjørn 

[Sridhar Jonnavittula]

Hi bjorn-spockeli,

1. In only case 1 and case 2, I used DFU over BLE.

2. And in third case I used make flash in armgcc to overwrite the application area. So, after doing this whatever application I updated in this case 3 should flash right. Is it like, I have to erase full chip and then do mentioned in step 2 here. Then obviously it will work.

 So, what should I do?

Thanks

[bjorn-spockeli]

The bootloader will check the stored application CRC generated during the DFU process against the CRC of the application in flash( the bootloader calculates this). Hence, if you perform a application DFU and then overwrite the application with a new application that is not identical with the one that was "DFUed in", then the bootloader will not jump to the application since the CRCs does not match. 

As I stated in my previous response, you need to generate the bootloader settings hex using nrfutil and then flash that together with the new application to set the correct application CRC in the bootloader settings page. 

Best regards

Bjørn 

[Sridhar Jonnavittula]

When doing secure BLE DFU bootloader example, we merge bootloader hex and bootloader settings hex using mergehex command and then program with command nrfjprog --reset --program bootloader.hex --family NRF52 –sectoranduicrerase right

If I want to program only bootloader settings hex into it's respective page and then example_application.hex then how can I do this?

Thanks

[Sridhar Jonnavittula]

What I did is health thermometer application I updated over the air securely with BLE. Then I generated bootloader settings hex page for nordic keyboard application like you said and programmed using 

nrfjprog --reset --program application.hex --family NRF52 –sectoranduicrerase command.

Then updated actual keyboard hex file using 

nrfjprog --program keyboard.hex --sectorerase command.

After reset it is showing as nordic_keyboard in nrfconnect mobile app.

Thanks for your help bjorn!!