RT685 PUF key storage questions

[JerryQian_132]

I have create the project in MCUXpresso Secure Provisioning, which is to sign our bootloader of RT685.

As above picture, the generated write_image_win.bat will write the sbkek and userkey. Where are the keys stored in? 41.5.1.4.1 Basic function of the FlexSPI remap has the KEY STORE areas. Are they used to save the keys? Is it possile to read the keys in code?

I also noticed that Table 1058.Key type details have 12 key types.

Above wirting script only uses 3 key types. Can I use other types, like 0x4 to 0xA, to save our application keys? I have tried set_user_key, but failed. Could you shared the blhost command and API to read the keys in code?

[jingpan]

Hi @JerryQian_132 ,

Please refer to 42.2.4 and 42.2.5 for where the key is stored and how it is used. The last write_key_nonvoletile command is write the keys to flash 0x800(42.5.5.1). You can use GetKey command to read these keys.

AN12324 has the detail of PUF. Although it is for LPC55, but RT600 is same.

Regards,

Jing