According to one embodiment, a method comprises detecting loss of lockstep (LOL) for a processor in a multi-processor system. The method further comprises determining that the processor for which the LOL is detected is assigned the role of boot processor, and switching the role of boot processor to a spare processor without shutting down the system's operating system. In another embodiment, a method comprises system firmware determining that an LOL is detected for a lockstep pair of processors that are assigned the role of boot processor in a system. The method further comprises determining one of the lockstep pair of processors that is not the cause of the LOL, and copying the state of the determined one of the lockstep pair of processors that is not the cause of the LOL to a spare processor. The method further comprises switching the role of boot processor to the spare processor.