Abstract: A method of booting a multi-processor data processing device includes establishing a link between a first processor and a memory. The link is monitored to determine if, in response to a request from the processor, expected initialization data is communicated between the memory and the first processor. If unexpected data is detected on the link, the link is severed and a new link established between a second processor and the memory to allow the second processor to initiate the boot process. This ensures that, in the event of an error in the boot process at the first processor, the device can complete the boot process, thereby reducing device downtime.

Abstract: Recovery circuits react to errors in a processor core by waiting for an error-free completion of any pending store-conditional instruction or a cache-inhibited load before ceasing to checkpoint or backup progress of a processor core. Recovery circuits remove the processor core from the logical configuration of the symmetric multiprocessor system, potentially reducing propagation of errors to other parts of the system. The processor core is reset and the checkpointed values may be restored to registers of the processor core. The core processor is allowed not just to resume execution just prior to the instructions that failed to execute correctly the first time, but is allowed to operate in a reduced execution mode for a preprogrammed number of groups. If the preprogrammed number of instruction groups execute without error, the processor core is allowed to resume normal execution.