Li Feng developed tablet mode support for the Dasharo/coreboot repository by enabling lid-open and close detection at the firmware level. Using C and leveraging embedded systems expertise, Li configured the previously unused GPP_F23 pin as an ISH GPIO, allowing the firmware to detect lid state changes and trigger tablet mode behavior. This required careful coordination between the AP and ISH firmware stacks to ensure seamless signal handling and device usability. The work focused on hardware-level integration and GPIO configuration, addressing convertible device requirements and improving firmware interoperability. The feature was delivered with clear traceability and demonstrated solid depth in embedded firmware development.