Unable to load the *.sb3 file to the MCXW71

[Arjv]

We were trying to program the MCXW71 chip. From the Getting Started with FRDM-MCXW71 page, we read that a secure Binary (*.sb3) has to be loaded prior to flashing any wireless example into the chip.
So following the instructions in the page, we tried to download the .sb3 file into the module using a USB-UART bridge. When scanned for device, the Port and the device was detected as mboot device.

But when tried to send the .sb3 file, the sending was aborted showing the error shown in the attached image.

The .sb3 file was collected from the SDK itself, from the path mentioned in the getting started page. we were bit confused which file is to be send, since there was 3 .sb3 files. so we tried sending all 3 files, but all was showing the same error.

[sofiaurueta]

Hello,

Hope you are doing well.

Unfortunately, it seems the image was not uploaded correctly, if you could reattach the error logs mentioned it would be greatly appreciated.

Could you please help us with more information about the procedure you are following to load the NBU image, and what SDK version you are using?

Also, could you be more specific on what application you are implementing or what SDK example you are running? For standard BLE applications such as the ones implemented in the SDK examples, "mcxw71_nbu_ble_hosted.sb3" is the file that supports general BLE features.

Best Regards,

Ana Sofia.

[Arjv]

Dear sofia, 

Thanks for the reply...

Sorry that the images were not uploaded properly.

I'll try to upload the images and the debug log from the SPSDK tool.

I have followed the exact same procedure mentioned in the Getting Started with FRDM-MCXW71. 

I am using SDK version 24.12.00, downloaded directly in the MCUXpresso IDE.

I even tried downloading the sdk as a zip file via the SDK Builder also.  But the .sb3 file available in that sdk also didn't work for me. 

<ksdk id="MCUXpresso250600" name="MCUXpresso250600" version="25.06.00" revision="890 2025-06-27"/>

We have designed a custom module with the MCXW71 chip. We are trying to test the RF Functionalities with the module. So as an initial step we flashed the adv_ext_peripheral_bm example form the SDK. 

While running the application, we noted that the application example is hitting a breakpoint in PLATFORM_InitMulticore(). So after some reading we understood that before flashing any wireless example, a matching secure boot file has to be loaded into  the chip. And referring to the getting started page, we tried to load the mcxw71_nbu_ble_hosted.sb3 file. And when the attempt failed, we tried to load other two sb3 files too, but those attempts were also failure. 

Could you please help us find out where did we go wrong???

Regards, 

Arunraj

[sofiaurueta]

Hello,

We need to confirm if the SB3KDK is correct, could you follow the steps from AN14568 Debug Authentication on MCXW71 section 5.4.1 Generate SB3KDK?

If you want to use your board for development same as the KW45-EVK/FRDM-MCXW71 you could use the same keys values from the KW45B41Z-EVK/FRDM-MCXW71 board directly, the specifications for these keys are mentioned on 5.4.3 SB3.1 generation.

Afterwards, you would have to reprogram the SB3KDK with the value keys mentioned. If the command returns failed, that means the SB3KDK is burned different. The SB3KDK is a secure area that can't read out, it stores the AES key. Both the SB3KDK and ROTKTH are only 32 bytes even if a 48-bytes key provided.

If possible, I suggest using another board for the test. Please refer to the link below for a summarized script of the secure boot process:

https://github.com/nxp-appcodehub/dm-kw45-secure-boot-scripts

Best Regards,

Ana Sofia.