topic Re: how to check image CRC in MCX Microcontrollers

how to check image CRC

victorchiou — Wed, 03 Jul 2024 10:27:07 GMT

I have an image built using the MCUXpresso Secure Provisioning Tool.

It's a plain image with a CRC,
and the offsetToExtendedHeader field(address 0x00000028) contains the 4bytes CRC checksum value.

Now, I want to check the CRC before writing it to flash.
I tried to calculate it using these settings,
but I cannot match the CRC with the offsetToExtendedHeader field.

(ref: Kinetis Bootloader v2.0.0 Reference Manual)

Is there any tool available to calculate the image CRC (like nxpimage and blhost)? Alternatively, where can I find more details about calculate the image CRC?

Re: how to check image CRC

marek-trmac — Wed, 03 Jul 2024 12:14:47 GMT

Hi Victor,

SEC tool uses SPSDK application nxpimage to build a CRC bootable image. You can see generated build script to find, how the nxpimage tool is used.

See main menu > Help > SPSDK Online Documentation for nxpimage documentation.

SPSDK is opensource, so you can find implementation details in GitHub.

回复： how to check image CRC

victorchiou — Thu, 04 Jul 2024 10:04:34 GMT

Hi Marek

I found the Mbi_ExportMixinCrcSign function
and the CRC algorithm in the nxpimage tool, which is part of SPSDK.

Based on the above algorithm,
I created a python program to verify the image CRC,
and it works.

Thanks for your support.