• State Accepted Answer
  • Locked Locked
  • Replies 5 replies
  • Subscribers 351 subscribers
  • Views 13321 views
  • Users 0 members are here
Options
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Non-secure peripheral with a secure interrupt handler

Rajiv

Hi,

I was wondering if it was possible to configure a peripheral to be in non-secure mode and have the interrupt handler associated with the peripheral run in secure mode?

Basically by not setting the appropriate bit in NVIC_ITNSn.

Best,

Rajiv

Parents
  • 0 in reply to Uma Ramalingam

    Hi Uma,

    Thank you for your reply.

    That's correct. Sorry I forgot to mention about CONTROL.nPRIV.

    Yes, within the interrupt handler, besides changing the EXC_RETURN.Mode, I would also need to do something like -

    mov r0, #0

    msr control_ns, r0

    Before doing a bx lr.

    This should get me back to non-secure privileged thread with MSP_NS. Isn't it?

    Best,

    Rajiv 

Reply
  • 0 in reply to Uma Ramalingam

    Hi Uma,

    Thank you for your reply.

    That's correct. Sorry I forgot to mention about CONTROL.nPRIV.

    Yes, within the interrupt handler, besides changing the EXC_RETURN.Mode, I would also need to do something like -

    mov r0, #0

    msr control_ns, r0

    Before doing a bx lr.

    This should get me back to non-secure privileged thread with MSP_NS. Isn't it?

    Best,

    Rajiv 

Children
  • 0 Arm Employee Badge in reply to Rajiv

    There is no need to change the CONTROL and EXC_RETURN if the mode and state before and after the ISR are the same. The EXC_RETURN has been extended to support additional information about security states, so all the Secure ISR can be implemented as normal C function.

    regards,

    joseph