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.
Thanks in advance.