March 2026 - OpenXiangShan/XiangShan: Performance-oriented memory subsystem optimization, reliability hardening, and maintainability improvements. Delivered across LoadUnit, Uncache, StoreUnit, MainPipe, LoadQueueReplay, and WritebackQueue to boost throughput and pipeline timing; enhanced MMIO fault handling per RISC-V specs; and MemBlock cleanup to improve readability.

Monthly summary for 2026-01 focusing on OpenXiangShan/XiangShan: Delivered core load/store path improvements, NC handling, and performance visibility, with refactors and bug fixes across Load Unit, DCache, and prefetched store paths. The changes improve data correctness, support for unaligned loads, and provide instrumentation for performance optimization, aligning with business goals of reliability and throughput.

2025-12 Monthly Summary: OpenXiangShan development focused on memory-subsystem modernization and correctness hardening across two core repos (CoupledL2 and XiangShan). Key features delivered include a modular LoadUnit pipeline framework in XiangShan, enhanced memory access handling, and multiple structural refactors to improve maintainability. A critical timing-path bug fix in CoupledL2 ensures correct opcode handling through the GrantBuffer path when Directory reports errors, reducing risk of incorrect memory requests. The combined work strengthens system reliability, facilitates future feature work, and demonstrates strong hardware-software co-design.

November 2025 monthly summary highlighting concrete deliverables across OpenXiangShan/XiangShan and OpenXiangShan/CoupledL2. Focused on governance, reliability, and memory management improvements that enhance system stability, maintainability, and time-to-delivery.

OpenXiangShan/XiangShan — 2025-10 Monthly Summary: Delivered targeted improvements to memory block integrity, XSCore reliability, and interrupt handling, reinforcing system stability and performance for the next software/hardware cycle. The changes emphasize safer signal routing, clearer error paths, and more scalable local interrupt management across BEU and L2Top/XSTile.

September 2025 - OpenXiangShan/XiangShan: Implemented Code Ownership Governance Update to reflect current component ownership, improving code review routing, accountability, and compliance. No major bugs fixed this month. This governance change reduces review delays, enhances ownership traceability, and supports safer, faster releases.

July 2025 Monthly Summary: Delivered stability improvements and dependency alignment across OpenXiangShan projects. Key fixes include MSHR invalid RefillBuf write prevention during replacements, and a dependency upgrade to CoupledL2 to keep XiangShan aligned with upstream changes. These changes reduce data integrity risks, prevent assertion failures, and simplify future maintenance.

June 2025 monthly summary for OpenXiangShan/XiangShan focusing on reliability and integration improvements.

May 2025 monthly performance summary for OpenXiangShan projects. Delivered targeted feature work and architectural improvements across two repositories (XiangShan and CoupledL2), emphasizing dependency modernization, governance, and performance enhancements in memory subsystems and link-layer interfaces. The changes reduce risk, improve upstream compatibility, and boost transaction throughput while maintaining build stability.

April 2025 monthly summary highlighting key features delivered and bugs fixed across OpenXiangShan/XiangShan and OpenXiangShan/CoupledL2, with emphasis on business value and technical achievements.

March 2025 performance summary for OpenXiangShan projects focusing on stability, observability, and memory subsystem reliability. Delivered cross-repo improvements in XiangShan and CoupledL2, introduced performance counters for TL2CHICoupledL2, and fixed critical data integrity and attribute handling bugs in memory subsystems. These efforts enable faster issue diagnosis, better performance analysis, and more robust hardware-software interactions.

February 2025 performance summary focusing on reliability, compatibility, and configurability across OpenXiangShan projects. Key improvements include external submodule upgrades, new DebugModule TileLink bus configurability, and a set of critical bug fixes that improve fairness, cache coherence, and pipeline correctness. These changes collectively enhance system stability, reduce risk of starvation, and enable more flexible hardware experimentation across the SoC stack.

January 2025 performance highlights across OpenXiangShan/CoupledL2 and OpenXiangShan/XiangShan. Delivered robust issue-specific protocol handling improvements with Issue C support and restructuring of CHIMsgParameters to enable issue-based opcodes. Achieved timing and stability gains in SRAM→ICG paths by decoupling operations with intermediate registers and valid signals, reducing timing risk in critical datapaths. Fixed data path integrity issues, including CCID derivation alignment in TXDAT and hardened Poison handling in MMIOBridge/MSHR, improving correctness and resilience to edge cases. Implemented a controlled rollback of prior performance-oriented changes (L2Hint/CustomL1Hint) to restore stable behavior. In XiangShan, resolved MainPipe data selection bug, strengthened AtomicsUnit fault handling on uncache/MMIO, corrected CoupledL2 Poison assertion, and introduced Core-SoC signal routing through L2Top with new MSI information and CPU power-off bundles to improve timing and signal integrity. Overall, these efforts improve reliability, protocol compliance, and system readiness for upcoming performance features while reducing risk in data paths and inter-module signaling.

December 2024 Monthly Summary: Across OpenXiangShan/XiangShan, OpenXiangShan/difftest, and OpenXiangShan/CoupledL2, delivered correctness fixes, interoperability enhancements, and process improvements that drive reliability and faster integration of new capabilities. Key deliverables include atomic operation data handling fix in MainPipe, correct queuing of non-atomic stores, improved DCache fault reporting, Zacas support enhancements via submodule upgrades, and Zacas extension support added to difftest, with CODEOWNERS alignment to streamline reviews.

November 2024 performance summary focusing on feature delivery, bug fixes, and efficiency improvements across the OpenXiangShan/XiangShan and OpenXiangShan/CoupledL2 repositories. The month emphasized architectural enhancements, configurability, correctness, and observability to accelerate validation, reduce risk, and enable leaner hardware profiles.

Month 2024-10 monthly summary for OpenXiangShan/CoupledL2. Delivered a critical correctness and performance improvement in MMIOBridge by fixing the ReadReceipt wait condition, ensuring it only waits for s_txreq when a TXREQ is sent and not for w_readreceipt paths. This fix reduces unnecessary stalls and improves system reliability in the L2 memory subsystem.