How to make S32K146 M4 Core user mode and supervisor mode switching?

[paulzhou]

Dear Sir 

      How to make S32K146 M4 Core user mode and supervisor mode switching?

      Do you have demo code for this case? or reference application document ?

      Do S32K146 MCAL must do user mode and supervisor mode switching to meets functional security?

     Thank you!

[danielmartynek]

Hello,
If you need to switch to User mode, just set the nPRIV bit in CONTROL register

// switch to User (unprivileged) mode
 __asm__("mov r0, #0x01");
 __asm__("msr control, r0"); // nPRIV = 1‍‍‍

And to switch it back, you need to do it in SVC handler

// make a supervisor call (SVC) to transfer control to privileged software
 __asm__("svc #0x00");

void SVC_Handler(void){
 // switch to Supervisor (privileged) mode
 __asm__("mov r0, #0x00");
 __asm__("msr control, r0"); // nPRIV = 0
}‍‍‍‍‍‍‍‍

Unfortunately, I’m not familiar with MCAL.
Could you please create a service ticket?

https://community.nxp.com/docs/DOC-329745 

Regards,
Daniel

[paulzhou]

Dear Daniel
     Thank you for your help and this problem is solved