PROCEDURES AND REQUIREMENTS FOR THE REVIEW OF ACCOUNTING PRODUCTS AND THE EXCHANGE OF VEHICLES

摘要

A method and apparatus is provided to debug computer software remotely over a serial bus (e.g., the IEEE 1394 bus) between a host computer and a target computer. A kernel debugger on the target computer announces its presence by periodically sending "announce" packets on the bus. A host debugger on the host computer receives the "announce" packets and extracts from them the physical address of a memory area on the target computer that is memory mapped to an address space of the serial bus. The host debugger is thereafter able to directly write debug requests into the target computer's memory, and the kernel debugger on the target computer can service the debug requests without interrupting the CPU of the target computer. The kernel debugger on the target computer services the debug requests by writing into the shared memory area and indicating to the host debugger that data values are ready to be read directly over the serial bus without further intervention by the kernel debugger. In contrast to conventional techniques in which the target computer must transmit debug data to the host debugger, the host debugger is able to directly retrieve such data over the serial bus. The invention produces no side effects on the target machine (i.e., it doesn't slow down the operating system). Using an IEEE 1394 or other serial bus, software executing on a plurality of computers can be debugged over a single cable using high bus speeds.