Programming Embedded Systems, 2nd Edition

Remote Debuggers

If available, a remote debugger can be used to download, execute, and debug embedded software over a serial port or network connection between the host and target (also called cross-platform debugging). The program running on the host of a remote debugger has a user interface that looks just like any other debugger that you might have used. The main debugger screen is usually either a command-line interface or graphical user interface (GUI). GUI debuggers typically contain several smaller windows to simultaneously show the active part of the source code, current register contents, and other relevant information about the executing program.

Note that in the case of embedded systems, the debugger and the software being debugged are executing on two different computer systems. Remote debugger software runs on the host computer and provides the user interface just described. But there is also a backend component that runs on the target processor and communicates with the host debugger frontend over a communications link. The debugger backend provides low-level control of the target processor. Figure 5-2 shows how these two components work together.

Figure 5-2. Components of a remote debug session

The debug monitor resides in ROM—having been placed there either by you or at the factory—and is automatically started whenever the target processor is reset. It monitors the ...