Abstract: The invention relates to a method and apparatus for debugging program code. In particular, a method for implementing data breakpoints using virtual memory support is described. During execution of the program code, virtual memory addresses for translation to physical addresses are provided to a directory of page translations. If the page translation entry for the virtual memory address has data breakpoint information associated with it, a hardware walker is activated. The hardware walker searches a list of data breakpoints to determine whether a data breakpoint address corresponds to the virtual memory address and, if so, program execution is discontinued.

Abstract: A method is provided of managing hardware triggered hotplug operations of one or more input/output (I/O) cards of a computer system. The method comprises receiving hardware triggers, each of which relates to a hotplug operation to be carried out on an I/O card associated with a card slot, placing the hardware triggers in a queue, and processing the queue of hardware triggers. The method further comprises processing one or more of said hardware triggers. This comprises analysing a hardware trigger to determine the card slot to which said hardware trigger relates, and consulting a hotplug operation policy to determine whether hotplug operations are enabled for said card slot. If hotplug operations are not enabled for said card slot, this further comprises ignoring said hardware trigger, and if hotplug operations are enabled for said card slot, this further comprise querying said slot to determine whether it contains a card.