An interrupt routing mechanism implemented in a host chipset to eliminate the need for the general purpose I/O pins, special software and external logic devices to steer particular interrupts from a non-legacy Peripheral Component Interconnect (PCI) bus to an external interrupt controller. Such an interrupt routing mechanism may be implemented by a series of logic gates such as OR gates and AND gates for combining all interrupts from a non-legacy PCI bus to produce an output boot interrupt to an external interrupt controller, and alternatively, implemented by a series of AND gates for combining all interrupts from a non-legacy PCI bus and a switch for forwarding an output boot interrupt to an external interrupt controller in accordance with a disable bit used for the steering function.