Worked on the tianocore/edk2 repository to address a critical stability issue in PCI device enumeration. Focused on embedded systems and system programming using C, the developer identified and corrected an overflow in the PciAllocateBusNumber function, ensuring that PCI enumeration continues reliably under resource constraints. The solution involved precise handling of bus-number progression, preventing enumeration breakage and maintaining platform reliability. By adhering to MdeModulePkg practices and engaging in thorough code review, the developer improved the robustness of hardware interfacing routines, reducing boot-time risk and triage effort across builds. This work enhanced the reliability of PCI device initialization processes.