Issues with Buttonless DFU added to existing project

[Eduardo Garcia]

Hello:

We have a BLE project running on the BMD-300 from Rigado for which we want to add BLE DFU functionality. I am basing our development on the "ble_app_buttonless_dfu" project as well as the "secure_dfu_ble" for the bootloader. We are using NRF SDK 14.0.0 and IAR for our development. I have followed the great tutorial at "https://devzone.nordicsemi.com/b/blog/posts/getting-started-with-nordics-secure-dfu-bootloader" to generate the bootloader, bootloader options for application, merge bootloader+bootloader options, generate application,and load them up (also SD) with NRF GO. I set up the RTT logger on the main application.

I erase the chip, then I program the SD, then the bootloader, and then the application, and reset power. The unit always seems to be stuck in PC 0x13d6e of SoftDevice. Since it is a Hex I have no idea what it is doing there! I always have to attach to the running target and hit reset for the device to start performing properly. 

I was having issues with the bootloader not setting the vector table correctly to the app, so when I initialized my other HW the interrupts were getting sent to the bootloader!

To remedy this, I added a call to "nrf_dfu_svci_vector_table_unset()" at the start of the program.

However, now I am getting an NRF_ERROR_INVALID_STATE error on "sd_softdevice_enable()" when I initialize the stack (on ble_stack_init() ).

How is the correct way to add the Buttonless DFU functionality to the device? Is there an order of function that I should follow? should the DFU initialization happen before the HW initialization so the code sets up the correct vector table?

If you could provide any guidance I would be very grateful! I have spend too much time on this.

Thanks!

[Eduardo Garcia]

Another test, it seems that if I do the following I can get it to work:

*Disable WDT on main application (Don't know as of now how to handle WDT feeding on Bootloader, will search around...)

*Assume that SD can be already initialized: Added this code to "ble_stack_init()"

static void ble_stack_init(void)
{
    ret_code_t err_code;
    ble_cfg_t ble_cfg;
    if(nrf_sdh_is_enabled() == false){
      err_code = nrf_sdh_enable_request();
      APP_ERROR_CHECK(err_code);
    }else
    {
      NRF_LOG_INFO("SD is already enabled!");
    }
    ...
    }

*Assume LF clock is already initialized (on a function after BLE initialization that sets our App's HW):

->Note protection of "nrf_clock_lf_src_set(NRF_CLOCK_LFCLK_Xtal);"

int32_t CLK_lfclk_config(void)
{
  int32_t status = 0;
  status = nrf_drv_clock_init();
  if(status != NRF_ERROR_MODULE_ALREADY_INITIALIZED) //Assumption
  {
    nrf_clock_lf_src_set(NRF_CLOCK_LFCLK_Xtal);
    //APP_ERROR_CHECK(err_code);

    nrf_drv_clock_lfclk_request(NULL);
  }else
  {
    status = 0;
  }
  
  if (status !=0)
    return ((int32_t)CLOCK_ERROR);
  else
    return (0);
}

I kind of understand that the BLE bootloader may initialize the SD and the LF clock, but I am worried to not understand why the "secure_dfu_ble" did not do this. I also worry that I am missing something that might come back to byte me! Is there a list of components to take care of when adding buttonless DFU? Or, am I doing something wrong and because of that I need the changes I implemented?

Thanks!