When using OTFAD and HAB on the NXP RT1010, are there any flash locking or protection features ?

[Omar_hong]

Hi NXP,

As mentioned, we found that the Renesas AT25SF321B flash got unexpectedly locked during use.

When HAB and OTFAD are enabled, could certain operations—like a faulty flash burn—cause the

flash to enter a locked state (Non-Volatile Protection)?

[martin_lapis]

Hello @Omar_hong 

As far as I know, there is no protection feature related to using HAB or OTFAD security features on the RT1010. The RDC or TRDC modules, which are available in the RT1170 or RT1180 RT MCU lines, are not present in the RT1010.
I’m not entirely sure what you mean by "flash locked," but if you are referring to preventing unwanted modifications to flash sectors, you can use the Non-Volatile Protection feature implemented in Renesas flash chips to safeguard sensitive areas of the flash memory
.

Martin

[Omar_hong]

Hi @martin_lapis

Thank you for your reply

The "Flash lock" I previously mentioned refers to Renesas's Non-Volatile Protection (NVP). However, this NVP feature is not enabled in my current program. Despite that, there is a very small probability that the system unexpectedly enters the Non-Volatile Protection state.

Therefore, is it correct to assume that during dynamic decryption or MCU ROM execution, there are no mechanisms that could trigger Renesas's Non-Volatile Protection?

[martin_lapis]

Hello @Omar_hong 

When the BRC (Boot ROM Code) sets up the external flash, it processes the FCB block located in your application code. Part of the FCB includes the deviceModeCfgEnable and configModeEnable sections, which are responsible for executing commands (LUT records) at the moment the flash is configured.

You can use this functionality to set Non-Volatile Protection or any other protection feature offered by the external flash chip.

Of course, this requires a deep understanding of the FCB, which is represented by the flexspi_nor_config structure in any SDK-based application.

Best regards.

Martin

[Omar_hong]

Hi @martin_lapis 

Thank you for your reply

    Based on my understanding of this part, flash parameters can be adjusted through SPT. The modified parameters can be written to a specific block of the flash, and the ROM code will read the data from the flash. Then, it will configure the flash according to the settings defined by SPT, such as Max Frequency.

       I’ve been using the same configuration version, so theoretically there shouldn’t be any differences. However, I’ve found that the flash on some devices is actually locked

    That’s why I wanted to ask whether it’s possible that some mechanism in the ROM code operation might trigger the flash lock function(Non-Volatile Protection )