# Updating device firmware using DFU in Zephyr Project on a FRDM-K64F board **URL:** \ **Category:** Tutorials\ **Created:** [March 10, 2020, 8:01am UTC](https://hub.mender.io/t/updating-device-firmware-using-dfu-in-zephyr-project-on-a-frdm-k64f-board/1618 "2020-03-10T08:01:33Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![Utsav\_Shah](https://avatars.discourse-cdn.com/v4/letter/u/3ab097/32.png) [@Utsav\_Shah](https://hub.mender.io/u/Utsav_Shah)\ **Post date:** [November 29, 2023, 7:30am UTC](https://hub.mender.io/t/updating-device-firmware-using-dfu-in-zephyr-project-on-a-frdm-k64f-board/1618/2 "2023-11-29T07:30:21Z")
I have a question on the step number 4 where you mention to add certain flags which enables the device to automatically reboot. Being relatively new to this, I am not able to figure out where exactly do I need to add the config flags.Can you help me out with this? Also once a firmware update is flashed and is running on the peripheral device, and let’s say I have another firmware to flash (basically an update). How do I make my device automatically come back into DFU mode and flash the (updated) firmware instead of the currently running firmware? As the device currently is running a firmware, I was wondering how to automatically trigger it to boot again in DFU mode. Hopefully this issue makes sense. For reference, I want to try this out on an NRF5340 based system. Any help on both the queries would be super helpful. --- _[View the full topic](https://hub.mender.io/t/updating-device-firmware-using-dfu-in-zephyr-project-on-a-frdm-k64f-board/1618)._