A system and computer program product for initializing processor cores in a multiprocessor system. The system includes a microcontroller that initializes a first processor utilizing a common initialization image for all processor cores within the first processor. The first processor detects and executes system firmware. All remaining processors are initialized utilizing the common initialization image. The executing firmware detects a system configuration of the multiprocessor system. A customized processor initialization image for each of the processor cores in the multiprocessor system is generated and stored to a storage device. The processor cores are triggered to enter a power save state in which all initialization settings of the processor cores are lost. In response to all the processor cores entering the power save state, the first processor core of the first processor is re-initialized using a first customized initialization image generated for the first processor core.