topic Re: register MCM_PID in user task in S32K

register MCM_PID in user task

Yellen — Tue, 06 Jun 2023 01:46:13 GMT

Hi,

I want to use PID to define different access rights for different user tasks. It seems that I should dynamicly change the MCM_PID reigster.

Referring to the RM for S32K1xx, it says the MCM_PID is accessible only in Supervisor mode. While the user tasks are running at user mode. How can I change the MCM_PID in user tasks?

Best Regards,

Yellen

Re: register MCM_PID in user task

davidtosenovjan — Tue, 13 Jun 2023 09:13:39 GMT

Could you clarify where it is stated that MCM_PID can be accesses only in supervisor mode? In my opinion it is accessed in both modes.

Re: register MCM_PID in user task

Yellen — Tue, 13 Jun 2023 09:42:54 GMT

Hi David,

Thanks.

It lies in Section 10.3 of S32K1xx Series Reference Manual, Rev. 12.1, 02/2020.

Re: register MCM_PID in user task

davidtosenovjan — Tue, 20 Jun 2023 12:54:14 GMT

I have been confirmed that if application is in user mode, it can not change MCM_PID. Usually, the value of MCM_PID should be defined in supervisor mode.

Re: register MCM_PID in user task

Yellen — Wed, 21 Jun 2023 06:19:54 GMT

So will there be a way to define different values of MCM_PID for user application? Like a lib function that could change to supervisor mode and modify the MCM_PID, then return to user mode?