Is Secure user memory area code should be copy RAM then It should execute??

[DPUNDIR]

We have STM32H755XI6 Controller, and we trying to incorporate the secure boot in our current secure boot with RDP level 1 and secure user memory (HDP protection) but our controller is getting locked up and not able to access (using IAR JTAG and ST LInk JTAG CPU is not getting connected ).

after seeing some HDP examples code, the code with HDP protections (some particular functions) is running from RAM, Is my understanding correct? And we need to run the HDP-protected code from RAM.

IS Secure Boot code should run in Privileged mode ??

Please kindly help with this.

[Pavel A.]

It looks like your MCU is locked up in the "secure area" state, congratulation!

>  our controller is getting locked up and not able to access (using IAR JTAG and ST LInk JTAG CPU is not getting connected ).

This is what the "secure area" does. It prevents debugger access.

> And we need to run the HDP-protected code from RAM.

Yes IIRC in "protected area" state, code can execute from RAM. But the point is that it starts from the internal flash.

> IS Secure Boot code should run in Privileged mode ??

The MCU starts in privileged mode. Do you change the mode? Why?

[DPUNDIR]

Hi,

Thanks, Pavel for the quick response.

What is IIRC?

Just want to know how to revert back to this setting (secure bootloader to standard bootloader).

As per the UM2262 doc, we can revert back to this setting using the OB register but currently, the Debugger is not able to connect. Currently, the RDP level is 1, then it should connect with ST-link and OB register can be accessible.

and another problem I found is that the boot code is not jumping to OS. We use to this function to jump out of the secure boot: RSS->exitsecurearea(vector address) but looks like the function is not working as expected. Is anything we are missing?