1. A method for invasive debug of a processor without processor execution of instructions, said method comprising: using a debug port of said processor, accessing a memory mapped I/O of said processor; using said memory mapped I/O, initiating an operation that causes said debug port to gain access to registers of said processor; and from said debug port, and based on said access to said registers of said processor, executing said invasive debug of said processor, wherein said executing is performed external to said processor, wherein said debug port can initiate a plurality of invasive operations.