
Kehan Feng developed and optimized FPGA-based validation and testing infrastructure for the OpenXiangShan/XiangShan and OpenXiangShan/difftest repositories, focusing on hardware-software integration and performance. He refactored memory management and data handling modules using C++ and SystemVerilog, introducing BRAM-based buffering and XDMA-triggered resets to improve throughput and timing accuracy. His work included enhancing build systems, automating configuration management, and enabling direct serial communication for FPGA debugging. By documenting workflows and stabilizing synthesis paths, he reduced maintenance overhead and improved reproducibility. The depth of his contributions is reflected in architectural simplifications, resource efficiency gains, and robust, scalable FPGA validation pipelines.

September 2025: Focused on performance optimization, data path efficiency, and synchronized hardware/software timing for difftest. Delivered two high-impact features, established deterministic benchmarking capabilities, and laid groundwork for further FPGA optimizations. No critical bugs fixed this month; primary gains come from refactors and enhanced testability.
September 2025: Focused on performance optimization, data path efficiency, and synchronized hardware/software timing for difftest. Delivered two high-impact features, established deterministic benchmarking capabilities, and laid groundwork for further FPGA optimizations. No critical bugs fixed this month; primary gains come from refactors and enhanced testability.
Concise monthly performance summary for August 2025 highlighting delivered features, fixes, impact, and technical capabilities for performance reviews.
Concise monthly performance summary for August 2025 highlighting delivered features, fixes, impact, and technical capabilities for performance reviews.
July 2025 monthly summary focusing on architectural simplification, FPGA tooling stability, and improved documentation for reproducible FPGA-based validation. Deliverables spanned three repositories (XiangShan core, XiangShan-doc, and difftest), with strong emphasis on business value: reduced maintenance cost, faster FPGA validation cycles, and clearer onboarding for contributors.
July 2025 monthly summary focusing on architectural simplification, FPGA tooling stability, and improved documentation for reproducible FPGA-based validation. Deliverables spanned three repositories (XiangShan core, XiangShan-doc, and difftest), with strong emphasis on business value: reduced maintenance cost, faster FPGA validation cycles, and clearer onboarding for contributors.
For 2025-06, delivered targeted FPGA build and synthesis stabilization for OpenXiangShan/difftest, focusing on reliability and performance in the FPGA toolchain. The changes reduced synthesis-time blockers and improved compilation by enabling proper DMA_CHANNELS propagation and enabling GCC optimizations. In addition, a DPI-C interface improvement (dummy signal) eliminated a Vivado empty-module error, reducing CI failures.
For 2025-06, delivered targeted FPGA build and synthesis stabilization for OpenXiangShan/difftest, focusing on reliability and performance in the FPGA toolchain. The changes reduced synthesis-time blockers and improved compilation by enabling proper DMA_CHANNELS propagation and enabling GCC optimizations. In addition, a DPI-C interface improvement (dummy signal) eliminated a Vivado empty-module error, reducing CI failures.
May 2025 summary for OpenXiangShan/difftest: Delivered two performance-focused features that significantly improve validation throughput and memory efficiency. A Memory Pool Management Refactor decoupled raw memory storage from sorted data indicators, reducing memcpy overhead and improving allocation/deallocation efficiency. FPGA Difftest Batched Packet Transmission enables sending multiple packets per XDMA request, increasing PCIe bandwidth and dramatically speeding simulations. No major bugs fixed this period. Overall impact includes faster validation cycles, reduced resource usage, and improved scalability for FPGA-backed difftest workloads. Technologies demonstrated include memory pool refactor, XDMA/FPGA interfacing, and performance-oriented code design.
May 2025 summary for OpenXiangShan/difftest: Delivered two performance-focused features that significantly improve validation throughput and memory efficiency. A Memory Pool Management Refactor decoupled raw memory storage from sorted data indicators, reducing memcpy overhead and improving allocation/deallocation efficiency. FPGA Difftest Batched Packet Transmission enables sending multiple packets per XDMA request, increasing PCIe bandwidth and dramatically speeding simulations. No major bugs fixed this period. Overall impact includes faster validation cycles, reduced resource usage, and improved scalability for FPGA-backed difftest workloads. Technologies demonstrated include memory pool refactor, XDMA/FPGA interfacing, and performance-oriented code design.
March 2025 OpenXiangShan/XiangShan monthly summary focusing on delivering enhanced FPGA-based testing capabilities for TileLink and improving QA coverage.
March 2025 OpenXiangShan/XiangShan monthly summary focusing on delivering enhanced FPGA-based testing capabilities for TileLink and improving QA coverage.
Monthly work summary for OpenXiangShan/XiangShan (2024-11). Focused on FP AGI Difftest enhancement and its impact on debugging and validation workflows.
Monthly work summary for OpenXiangShan/XiangShan (2024-11). Focused on FP AGI Difftest enhancement and its impact on debugging and validation workflows.
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