DAP support in MSIM

Abstract

MSIM is a deterministic hardware simulator supporting RISC-V and MIPS R4000 CPUs. It provides instruction-level debugging through a simple command-line interface. The Debug Adapter Protocol (DAP) is a high-level debugging protocol designed to enable interoperability between code editors, IDEs, and debuggers. DWARF is a debugging information format commonly embedded in object files and used by debuggers for source-level mapping. MSIM is primarily used in the Operating Systems course at MFF UK for simulation of student operating system kernels, where advanced debugging capabilities can significantly improve the development experience. This thesis introduces a new debugging capability for MSIM by integrating DAP support through a dedicated debugging adapter responsible for bridging the source-level requirements of development tools with the instruction-level execution model of MSIM, using DWARF debugging information for source-level mapping. The implementation also introduces a lightweight custom binary protocol for communication between MSIM and the adapter, integrated directly into the simulator. In addition, a Visual Studio Code extension is provided to improve usability and integration with modern development environments. The implemented capability includes source-level breakpoints, execution control,...