Raising privilege causes a hard fault

tamirmichael wrote on Monday, September 24, 2012:


First I would like to apologize for posting a question that is not completely associated with FreeRTOS.
I am working with a LPC1788 + FreeRTOS MPU, and attempting to make lwIP fit it as well. However, I notice that raising privilege   (when exiting a critical section - vPortExitCritical) causes a hard fault. The CPU is in thread mode/unprivileged/PSP (it is not that a SVC is launched in an SVC), BASEPRI = 0x28, PRIMASK = 0, priority of SVC is 31.
Any ideas?

Thanks in advance.

rtel wrote on Monday, September 24, 2012:

There was a thread about using FreeRTOS-MPU very recently here.  I don’t seem to be able to find it because the search on this forum is not easy, and it has not been indexed by Google yet on in the archive (on the FreeRTOS site).

The conversation continued on the lwIP mailing list though.  I would recommend reading it because it pointed out some issues with lwIP that would make it hard to use with an MPU (as stack memory is shared across threads).


tamirmichael wrote on Monday, September 24, 2012:


Thanks for your reply. I managed to integrate lwIP with FreeRTOS MPU. I encountered none of the problems you mentioned. I manage to connect to a remote server using the socket interface, send some data and close the connection. However, I cannot share the code as it is a prototype for a commercial product. Thanks for your support.