Month: 2026-04 — Focused on stabilizing the coredump test suite for nsim_arc_v platforms within nxp-upstream/zephyr. The change fixes a timeout by configuring NULL pointer handling to trigger a fatal error via k_panic() on nsim_arc_v platforms, addressing test flakiness and improving CI reliability. Commit b74911bcf692a3a1c673a58f674b4ea45e9a41d8 accompanies this work and documents the platform-specific approach.

Monthly summary for 2026-03 focusing on nxp-upstream/zephyr. Highlights include the delivery of critical bug fixes improving kernel robustness and test stability on ARC hardware. Major changes were implemented to ensure atomicity in MPUv6 buffer validation and to align ARC timer tests with actual hardware clock configuration, resulting in more reliable behavior in production and testing environments.

February 2026: Delivered a targeted board bring-up improvement in nxp-upstream/zephyr by expanding MPU regions on nsim_em7d_v22 from 8 to 16, enabling broader userspace memory-domain tests and aligning with other ARC EM boards. This change reduced test failures in memory-domain scenarios and enhances test coverage for samples/userspace.

January 2026 monthly summary for nrfconnect/sdk-zephyr: Delivered a reliability improvement by introducing a new 'flash_before' option for ARC boards to prevent USB serial disconnections during flashing. The feature extends board YAML configuration and is applied by pytest and shell harnesses to ARC development boards (hsdk, hsdk/arc_hsdk/2cores, hsdk4xd, iotdk). This work reduces flashing flakiness in CI and local development, accelerating board bring-up and QA cycles.

December 2025 monthly summary for nrfconnect/sdk-zephyr: Delivered PSA Crypto Malloc Arena Support with MINIMAL_LIBC to enable PSA Crypto operations in environments where a heap is disabled by default. The change ensures compatibility of Mbed TLS PSA Crypto tests with MINIMAL_LIBC configurations, expanding test coverage and enabling deployment in resource-constrained builds. No major bugs fixed this month. Overall impact: improved crypto capability and test reliability in constrained environments, reducing risk for production deployments that rely on MINIMAL_LIBC. Technologies/skills demonstrated: embedded security (PSA Crypto, Mbed TLS), memory management (malloc arena), test automation, and Zephyr build/test integration.

November 2025 monthly summary for nrfconnect/sdk-zephyr: Implemented ARC IoT CPU Idle Power Management Enhancement with a configurable idle option to retain UART power during CPU idle, improving wake responsiveness and enabling peripheral interrupts without executing sleep. The change preserves default sleep behavior; a new CONFIG_ARC_IOT_CUSTOM_CPU_IDLE flag allows tests that require UART retention to run uninterrupted, addressing a hardware limitation that previously caused wake failures. This work improves reliability for IO-intensive test harnesses and supports timer-based idle transitions.

October 2025 — Delivered ARC-specific stack protection testing within Zephyr, addressing GNU toolchain compatibility and enhancing stack-check robustness for ARC targets. The test design omits frame pointers to align with ARC hardware stack checking, preventing false MPU violations and increasing validation reliability. This work strengthens kernel security validation and reduces toolchain-related risk for ARC architectures.

September 2025 monthly summary for zephyr-testing: Stabilized timeout handling in timer-less configurations by implementing a guard that prevents z_abort_timeout calls when the system clock does not exist, reducing spurious timeouts and improving determinism in absence of a clock. The change is scoped to kernel events with conditional guards.

August 2025 summary for zephyr-testing: Focused on reliability, cross-toolchain compatibility, and accurate telemetry. Implemented a libc-time_t compatibility default to ease Y2038 concerns across 32-bit toolchains; stabilized COBS test fixtures in minimal libc environments by tuning malloc arena to 256; hardened runtime statistics collection by introducing a volatile condition to the helper thread loop to prevent compiler optimization from erasing the statistic loop. Together, these changes reduce flaky tests, improve configuration flexibility, and deliver more trustworthy runtime metrics.

In July 2025, we focused on stabilizing timekeeping and test reliability for AmbiqMicro/ambiqzephyr. Fixed critical clock ID handling to prevent kernel errors and hardened UUID tests under MINIMAL_LIBC by enabling a minimal heap arena. These changes reduce runtime errors, improve test stability, and strengthen cross-layer compatibility between POSIX clock semantics and Zephyr clock IDs, delivering tangible business value through more reliable deployments and faster issue detection.