LPC Microcontrollers中的主题 Re: nxpdebugmbox fail : Device wants to send us different size than expected

nxpdebugmbox fail : Device wants to send us different size than expected

Aurelien_Grange — Mon, 30 May 2022 08:54:22 GMT

Hi,

I have some issue with NXPDEBUGMBOX.EXE.

I've got an error when i try to connect to mailbox.

I made some try to find a way to use both SBKEK and USERKEK (if both are used, I can't load USERKEK on AES engine). nxpdebugmbox works fine until the end of the last week.

Since I've got this error.

I Have no "Customer Defined" value in both CFPA and CMPA

How Can I recover the debugmailbox connection?

Re: nxpdebugmbox fail : Device wants to send us different size than expected

diego_charles — Wed, 01 Jun 2022 21:25:10 GMT

Hi @Aurelien_Grange

I hope to find you well!

Regarding your debug mailbox snapshot.

I have seen this error whenever PIN and DFLT do not have their inverse value. Additionally, the Secure provisioning tool shows that PIN and DFLT in both pages are set two zero.

Regarding "Customer Defined" area not appearing could you try to use BLHOST to directly read the CMPA and CFPA?

All the best,

Diego.

Re: nxpdebugmbox fail : Device wants to send us different size than expected

Aurelien_Grange — Tue, 07 Jun 2022 07:00:38 GMT

Hi; I can't read it, I have "again" brick my dev kit (I have 6 which are dead !!! ) trying to come back in unsigned mode using MCUXpresso Secure Provisioning. Blhost cannot ping device anymore anx nxpdebugmbox return

Re: nxpdebugmbox fail : Device wants to send us different size than expected

Aurelien_Grange — Tue, 07 Jun 2022 07:35:17 GMT

Re: nxpdebugmbox fail : Device wants to send us different size than expected

diego_charles — Thu, 23 Jun 2022 06:36:43 GMT

Hi @Aurelien_Grange

Unfortunately, if the debug authentication is failing and the ISP is not accesible the MCU is bricked, as you mention.

I already replied to your other post for embedding the SBKEK while using USERKEK, where I point your that it is posible to have both, My hypothesis is that the CMPA/CFPA used for while enabling the SBKEK did not have the inversed value on PIN and DFLT fields. So this derived in the problem you found.

Let me know if there is anything else we can check.

All the best,

Diego