Worked on architectural improvements to the tezos/riscv-pvm repository by implementing explicit program counter update control for system calls. This involved introducing a ProgramCounterUpdate enum and integrating it into the SystemCallResultExecution logic, allowing each system call handler to specify how the program counter should advance after a syscall. The refactor, developed in Rust and focused on low-level systems and RISC-V architecture, improved the correctness and predictability of program flow following system calls. These changes enhanced the maintainability and safety of syscall handling, laying groundwork for future enhancements and clearer semantics in system programming within the RISC-V PVM context.