topic Re: MXCW71 NBU firmware update in MCX Microcontrollers

MXCW71 NBU firmware update

MrShen — Fri, 31 Oct 2025 06:04:20 GMT

I am not using the FRDM-MCXW71 board, but a homemade board with a brand new MCU.

After entering ISP mode and using the command, the obtained serial port properties are the same, but uploading the firmware is unsuccessful. It might be an issue with the SB file.

May I ask if there is a pre-burned file on the development board? Or how to create a Custom SB file？

where can the required certBlock certificate and signer Image files be found, and could you provide detailed methods or files?

Operate according to the information provided:

Open a workspace for with the custom keys that were provisioned to the deviceKW45xx/K32W1xx/MCXW71xx/KW47xx/MCXW72xx
Copy NBU firmware into workspace as source_images\nbu_firmware.xipChange the file name to nbu_firmware。

3. In the menu bar, select Tools > SB Editor

4. Fill the Properties tab or import a setting from the SB file created on the Build tab

Where can the nbu_firmware.xip and certBlock files be obtained? To implement wireless communication functions such as Bluetooth and ZigBee.

Re: MXCW71 NBU firmware update

marek-trmac — Fri, 31 Oct 2025 06:32:17 GMT

Hi @MrShen

The FW for development board is distributed withing MCUXpresso SDK and you can use either version signed with keys burned on development board or create SB file signed with custom keys. The process is described in the documentation:

Processor-specific workflows — Secure Provisioning Tool 25.09

Re: MXCW71 NBU firmware update

MrShen — Sat, 01 Nov 2025 14:54:27 GMT

Hello! Copy NBU firmware into workspace as source_images\nbu_firmware.xip。Which NBU firmware is this?

Re: MXCW71 NBU firmware update

Christine_Li — Mon, 03 Nov 2025 08:43:55 GMT

Hi， @MrShen

Have you resolved this issue?

I saw you mentioned that you already can do NBU firmware update in another post:

https://community.nxp.com/t5/MCX-Microcontrollers/After-MCXW71-performs-NBU-Firmware-update-debugging-cannot/td-p/2197153

If this issue is already resolved, would you mind share your resolution here and also mark it as a resolution? So that our other customers can refer it.

Thanks for your contributions in our community!

Best regards,

Christine.

Re: MXCW71 NBU firmware update

MrShen — Mon, 03 Nov 2025 09:40:17 GMT

Currently using NXP's key。