prevention of running code from ram

Question

Hi.
Can the nrf52840 prevent running code from RAM ? in general ?
I know there are bits of code in the nrf sdk that transform byte codes into a function (so it's in ram) and then run it, but i want to prevent like in modern OSes running from the stack (like there are pages and each page can have the no execution flag set, but the processor is the one to verify that).

user7377 · Accepted Answer

Hi, 
 The MPU can be used to prevent code execution from RAM. If you use the nRF Connect SDK, which is Zephyr based, this is prevented by default. See Memory map and MPU considerations , specifically: 
 One MPU region programs the entire SRAM area with privileged-only RW permissions. That is, an MPU region is utilized to disallow execute permissions on SRAM. 
 If you are using the nRF5 SDK you have to enable this yourself, for instance using the MPU driver .

prevention of running code from ram

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