Worked on the tianocore/edk2 repository to deliver a targeted firmware improvement by addressing a critical bug in the PL011 UART control bit validation logic. Focused on aligning the PL011UartLib implementation with the UEFI specification, the developer updated the set of allowed control bits and refined the validation process within the SetControl() function. This C programming effort in embedded systems and firmware development ensured that only spec-defined bits are accepted, preventing invalid serial control operations. The fix resolved SCT test failures, improved UART reliability on ARM platforms, and enhanced UEFI compliance, contributing to more robust platform initialization and serial debugging.