Request to Remove Second Partition for Single-Image OTA on nRF52840

[Syam Prasad]

Hi,

I am working on a project using the nRF52840 SoC with both Zigbee and BLE enabled, along with Mbed TLS and JSON libraries. Due to memory constraints, the firmware binary exceeds the available space allocated for a single image slot in the default dual-slot MCUboot configuration.

To optimize flash usage, I would like to remove the second partition (slot-1) and use a single-application-slot configuration. However, despite modifying the devicetree and disabling related Kconfig symbols, the second partition still appears in the build or fails with memory overflow errors.

Could you please guide me on the correct and officially supported method to:

1. Disable or remove the second image partition (slot-1).

2. Reclaim the memory space for use in the primary application slot (slot-0) using either overlay or pm_static.yml.

Regards,

Syam

[Edvin]

Hello,

How do you plan to transfer the DFU image? If you plan to do this either using BLE or Zigbee, then you can't have only one partition. This is because it is the old application that handles the transfer of the new application image. This is why, with the solution that we have today, it is not possible to do a BLE or Zigbee DFU using only one partition. 

If you are planning to do DFU over serial, on the other hand, then it is a different story, but I didn't get the impression this is what you are trying to do.

Best regards,

Edvin