MBR.Hex

RE: MBR.Hex

Charlie — Thu, 15 Jul 2021 12:39:41 GMT

Hi,

You can find an explanation from this tutorial: https://devzone.nordicsemi.com/nordic/short-range-guides/b/software-development-kit/posts/getting-started-with-nordics-secure-dfu-bootloader#h61sjziauupw1j397q9s9ldr01q4j6d5. Here is content related to your question:

The bootloader looks into its bootloader setting to detect if a valid application is flashed on the chip or not. Boot validation will be performed when booting. If we simply program the application with the bootloader using the programmer, the bootloader won't be able to detect whether a valid app is already exist and it will enter DFU mode instead. Your application won't start. Only after a successful DFU update the bootloader would write to the bootloader setting to mark the valid app.

Best regards,

Charlie

RE: MBR.Hex

Trump — Thu, 15 Jul 2021 02:38:15 GMT

Hello, I have another question about DFU upgrade.

I downloaded the three files in the picture above to NRF52840 through nrf connect, and the device is still stuck in the bootloader. I have to execute this command (nrfutil dfu serial -pkg blinky_mbr.zip -p COM4) to run blinky_mbr.hex app. I am not at this point. I understand. hoping to get your help.

Best regards

RE: MBR.Hex

Charlie — Mon, 12 Jul 2021 11:48:06 GMT

Hi,

Just like softdevice, MBR is also closed source software. We do not provide source code to developers. Any special reason you need it?

Best regards,

Charlie