Worked on the levizh/rt-thread repository, focusing on enhancing system stability, reliability, and security in embedded environments. Addressed concurrency issues in multi-threaded file operations by refining the handling of file pointer positions, ensuring correct return values and robust file system behavior. Improved build reliability by resolving compilation errors related to file system configuration. Delivered a security-hardening update by validating MBR signatures and enforcing partition boundary checks, preventing invalid partition data from compromising system integrity. All changes were implemented in C, leveraging expertise in embedded systems, file systems, and multi-threading to improve maintainability and align with best practices for secure system programming.