In a processing system with a main partition and a sequestered partition, the main partition sends an interrupt to the sequestered partition before calling an operating system (OS) boot loader for the main partition. The sequestered partition may then enter an interrupt handler. After the sequestered partition enters the interrupt handler, an address line of the processing system may be disabled, and the OS boot loader for the non-sequestered partition may be called. The sequestered partition may then determine whether the address line has been re-enabled. The sequestered partition may remain in the interrupt handler until after the address line has been re-enabled. Other embodiments are described and claimed.