bad application behavior after bootloader DFU

[gkovelman_tap]

Hi all,

I'm using SD S132 v5.0.0 with SDK 14.0.

I'm testing now the BL buttonless DFU (and later the SD buttonless DFU) after working well with the app buttonless DFU.

The app DFU is working well (dual bank and single bank). For the BL DFU, after the DFU procedure, the application gets into some weird behavior (looks like too fast freertos ticks). and that requires reset to recover (soft or power reset)

Using some comparing BL logs between the app DFU and the BL DFU, I'm seeing that the BL is missing some soft reset before launching into application according to code documentation, that should be triggered in this procedure:

        // Upon successful completion, the callback function will be called and reset the device. If a valid app is present, it will launch.
    NRF_LOG_DEBUG("Writing settings and reseting device.");
    ret_val = nrf_dfu_settings_write(reset_device_callback);

However, the last lines of the log are the following: pastebin

Meaning, that nrf_dfu_reset_timeout_handler is never called and the app is launched without this reset.

More parameters:

• Secure bootloader is the same as in example, except for setting 3 GPIOs to HIGH and removing the button.
• NRF_DFU_POST_SD_BL_TIMEOUT_MS is set to 10000 (default value)

Am I interpreting this correctly? Do I need this missing reset for the application to boot up cleanly?

Thanks

[Bjørn Kvaale]

I tested the buttonless dfu example and it worked without any issues. What I did was follow the secure dfu blogpost first. Do the exact same things in Step A & B. Build the secure dfu bootloader. In step C, use the built buttonless secure dfu hex file instead of the secure dfu hex file. Then, remember to use the buttonless dfu application hex file instead of the secure dfu hex file. Also, remember to use the correct hexadecimal code for the softdevice you are using. If you are using the 5.0.0 SD, the code is 0X9D. You can use the command nrfutil pkg generate --help to check if you are using the correct hexadecimal code. Then, use the nrf toolbox app for iOS/Android to upload the DFU using the DFU app. When the app reaches 100%, it should start advertising automatically as DFU Buttonless (or something similar).