June 2026 (zephyrproject-rtos/zephyr) focused on key structural improvements and cross-series performance enhancements. Two major features were delivered: (1) Ethernet DWMAC driver reorganized into its own directory with updated build configuration (CMakeLists.txt and Kconfig), improving maintainability and future extensibility. Commit: c9835defa4b959f9089c15aed162058f922cc737. (2) Cache support across STM32 series (H5, C5, WBA, U5, L5) with device-tree driven cache line sizing, enabling data and instruction caching while preserving hardware-defined line sizes. Commits include aff884b409bc1702750e9a5be7c6c46124412a09; 27db80a1d1fcf2f0fd9a896cd3aa0f1954660244; aabf28b412aaab63652938fe0c9753ee4728b825; f3d568e2179105ff131dbaf645fde0c4ed69189b; 83b739049cc6a8846927e53b97b0cf1b3929a94b; 907ace5832656d465c2a9b537939ff801b47ae7b. These changes enhance memory performance, configurability, and cross-series consistency. (Also includes robustness improvements to retain device-tree provided D/ICACHE_LINE_SIZE.)

May 2026 monthly summary: Improved networking reliability in Zephyr by implementing a spinlock-based thread-safety mechanism for socket operations, addressing crashes under high load.

December 2025: Focused on W5500 Ethernet driver improvements in the Zephyr-based SDK. Delivered configurable timeout and link status reporting, improving tunability and diagnostics for networked devices. Changes optimize driver behavior by using Kconfig timeout directly and implementing get_link via the Ethernet PHY API.