Does i.MX 8X provide an SCU inhibit service in the SCFW?

[EAlepins]

Hi,

For safety reasons, out of boot and initialization, it might be desirable to shutdown the i.MX 8X's SCU subsystem (SCU Cortex-M4 + SECU Cortex-M0 + peripherals) in order to guarantee it won't make any unexpected accesses in the SoC (i.e. on the interconnect). In our case, past the initialization phase, we no longer need to send RPC calls to SCU (Messaging Unit), so we no longer need the SCU.

Is there a service in the SCFW to isolate / passivate the SCU? If not, is the HW there to perform that (XRDC, SCU power/clock gating, etc.) but simply the SCFW SW missing the feature? Can a customer add itself such a service by customizing the SCFW's board.c?

Thanks,

Etienne

[igorpadykov]

Hi Etienne

>For safety reasons .. desirable to shutdown the i.MX 8X's SCU
>.. to guarantee it won't make any unexpected accesses in the SoC..
>..Is there a service in the SCFW to isolate / passivate the SCU?

sorry there is no way to disable/shutdown SCU, no customizing the SCFW's board.c.

Please note that SCU is responsible for all processor security features (SECO) as depicted in

Figure 1-1. i.MX 8QuadXPlus/i.MX 8DualXPlus Simplified Block Diagram

i.MX 8DualXPlus/8QuadXPlus Applications Processor Reference Manual

For processor protection ( to guarantee it won't make any unexpected accesses in the SoC)

one can look at AN12312  Secure Boot on i.MX 8 and i.MX 8X Families using AHAB

and other security application notes on link:

https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-proces...

Best regards
igor