If the system I am working on detects a failure condition, it is required to lock up and flash a single LED.  This is done in a simple loop using cycle counts for the LED flashing – no RTOS timers. Is simply disabling all interrupts ensure the RTOS stops running? There is no intention to restart the RTOS once this has happened so state information is not important.

Disabling all interrupts, and then not calling any FreeRTOS functions will prevent any further FreeRTOS activity.

Excellent, thanks.