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Software timers and FreeRTOS-MPU

Posted by Artem Pisarenko on February 26, 2013
"Known Issues with the Current Version" lists that software timers don't work in MPU.
In recent kernel releases I found this:
"+ The software timer service (daemon) task is now created in a way that to ensure compatibility with FreeRTOS MPU."
But it's not enough.
Question to developers: When full support will be available ?

RE: Software timers and FreeRTOS-MPU

Posted by Richard on February 26, 2013
It was not currently high on the priority list, but you can update the relevant port.c and mpu_wrappers.h files to add in the additional functions you require. Without actually having tried it I can't foresee any issues. I think the timers.c/h files already have the necessary PRIVILEGED_DATA and PRIVILEGED_FUNCTION qualifiers, although you may find some missing when you actually use the files.


RE: Software timers and FreeRTOS-MPU

Posted by Artem Pisarenko on March 1, 2013
Although it looks like simple to wrap several functions, update mpu declarations and ensure qualifiers are present, I would rather wait for official tested release. :)
For those, who want to try:
1. in include/timers.h add PRIVILEGED_FUNCTION at end of xTimerGetTimerDaemonTaskHandle()
2. in include/mpu_wrappers.h add MPU_xxx macro definitions for timer functions (similar to other ones):
- xTimerCreate
- pvTimerGetTimerID
- xTimerIsTimerActive
- xTimerGetTimerDaemonTaskHandle
3. in port.c add #include "timers.h"
4. in port.c add MPU_xxx timer functions definitions (similar to other ones), they just accept same arguments, raise privilege, call corresponding function with parameters passed, save return value, reset privilege and return saved return value same as original function, also they must be wrapped in same #if...#endif conditions as their definitions in timers.c do.
It should work, but maybe I missed something :)

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