Simulation-based HW/SW co-debugging for field-programmable systems-on-chip

We are presenting SimXMD (Simulation-based eXperimental Microprocessor Debugger), a tool that allows developers to debug microcontroller code and custom hardware simultaneously. SimXMD connects a GNU debugger instance to a full-system simulation of an embedded FPGA system. This enables free-roaming investigation of hardware-software interactions inside the system, including reverting back to an earlier point in simulation time. A custom memory logging mechanism enables access to variables in on-chip, off-chip and cached memory. SimXMD is open source, and its modular architecture facilitates extension to other embedded processors as well as different simulators and debuggers.