TrustZone TFM Example Problems

[JamesB]

We have a project where we're using a U5A5 MCU with trustzone enabled and we're currently trying to figure out how to flash without having to use the SAM card. I downloaded the example from ST and am trying to run through the  B-U585I-IOT02A TFM example application on my NUCLEO-U5A5ZJ-Q development board. Running unmodified, I am able to build all three projects (appli, loader, boot) and the regression.sh run without errors, the TFM_Update.sh script runs without errors, but when I connect to the terminal, I get the following repeating pattern.

I've already tried pressing the reset button as well as removing and putting back the IDD jumper. Any help would be appreciated!

[Jocelyn RICARD · Accepted solution]

Hello @JamesB ,

I would suggest disabling TAMPER feature in the configuration file (boot_hal_cfg.h).

#define TFM_TAMPER_ENABLE NO_TAMPER

or

#define TFM_TAMPER_ENABLE INTERNAL_TAMPER_ONLY

Best regards

Jocelyn

[JamesB]

With that change I now get this. It repeats continually over and over (boot loop?)

[JamesB]

When I pressed the "User" button on the development board, it stopped looping and continued as expected, although does not seem to start at the main entry point but rather a sub-menu.

[Jocelyn RICARD]

Hello @JamesB,

when pressing blue button upon reset, you go into the standalone loader.

What happens here is that when launching TFM or non secure application, a reset occurs.

It is probably related to deference of memory sized between original chip and target chip.

A porting has to be done to adapt the GTZC configurations.

Best regards

Jocelyn