nrf52840-Dongle bootloader doesn't like it when app is programmed via nrfjprog

RE: nrf52840-Dongle bootloader doesn't like it when app is programmed via nrfjprog

Einar Thorsrud — Fri, 04 Mar 2022 10:00:26 GMT

You can debug and single step etc. from Segger in the exact same way as long as you program bootloader settings. But the moment you build and flash new firmware (via Segger or another way) without updating the settings page, the application will not be started, and debugging will also fail.

That means that if you build from SES and programs from SES, whenever a new application is flashed, you need to generate and flash bootloader settings before running and/or debugging will work.

RE: nrf52840-Dongle bootloader doesn't like it when app is programmed via nrfjprog

mytzyiay — Thu, 03 Mar 2022 18:23:38 GMT

Thanks. What does this process look like if I'm trying to interactively debug (e.g. single step) an application through the Segger GUI, rather than manually generating images at the command line?

RE: nrf52840-Dongle bootloader doesn't like it when app is programmed via nrfjprog

Einar Thorsrud — Thu, 03 Mar 2022 08:50:56 GMT

Hi,

All the nRF5 SDK bootloader variants use a bootloader settings page (which is the very last page), which among other things includes a hash of the application. If you program an application via a debugger without updating this setting page, the bootloader will thing the application is corrupt, and will enter DFU mode instead of starting the application. What you need to do here is to also generate and flash a settings page whenever you flash an application via SWD. See Generating and displaying bootloader settings.