bootloader config missing from ble_app_uart_c example

RE: bootloader config missing from ble_app_uart_c example

bjorn-spockeli — Tue, 21 May 2019 14:07:19 GMT

Hi Gianfranco,

In our SDK the application transfers execution to the bootloader and then our bootloaders handle the transfer of the image over a selected transport layer( BLE/UART/USB). We do not do any decryption of the firmware image, we verify that the firmware image was signed using a public key in the bootloader that is derived from the private key used to sign the new firmware image. The firmware image it self is not encrypted.

A colleague of mine has modified the bootloader to support background DFU, you can find the code here. Just scroll down to the answer that has been marked as accepted/verified. There should also be a readme file in the .zip as well.

Best regards

BJørn

RE: bootloader config missing from ble_app_uart_c example

gdutk001 — Tue, 21 May 2019 13:20:36 GMT

The second option is what I'd like to implement. I need an application that will receive the firmware update via UART, de-crypt the hex file and then burn it into memory. I might be mistaken but I thought that was what the secure serial DFUs example in the SDKs were doing? If there is an alternative I can consider it, but the route I was taking considered merging parts of the secure_bootloader_uart_mbr example into my project(this what I have been having issues with).

thanks, Gian

RE: bootloader config missing from ble_app_uart_c example

bjorn-spockeli — Tue, 21 May 2019 13:02:18 GMT

Hi Gianfranco,

Our serial bootloader is a stand alone project that you compile and flash to the nRF52840 alongside your application. The only thing you should have to add in the application is a routine that resets the device to bootloader mode. Or are you implementing background DFU, i.e. that the new firmware is received by the application and the bootloader only performs the switch?

Best regards

Bjørn