Instrumentation Subsystem

A new instrumentation subsystem simplifies tracing and profiling of Zephyr applications by leveraging compiler-managed function instrumentation, allowing the recording of call-graph traces and statistical profiles at runtime.

OCPP 1.6 library

A new OCPP (Open Charge Point Protocol) library enables EV charging station development with Zephyr. The library implements OCPP 1.6 Charge Point functionality over WebSocket, supporting core profile operations including authorization, transaction management, and meter value reporting for communication with Central System servers.

Twister Display Harness

Twister can now validate on-target display output by capturing frames from a USB video camera and matching them against pre-recorded visual "fingerprints".

Developer Experience Improvements

Several new tools have been introduced to help with common development and troubleshooting tasks:

• dtdoctor to help diagnose Devicetree build errors.
• traceconfig build target to help understand where Kconfig symbols come from and their final values.
• Interactive footprint charts to visualize RAM/ROM usage of an application.

Expanded Board Support

Support for 105 new boards and 39 new shields has been added in this release.

Full Release Notes

The full release notes and list of major changes since the last release can be found here.

An overview of the changes required or recommended when migrating your application from Zephyr v4.2.0 to Zephyr v4.3.0 can be found in the separate migration guide.

Release Lifecycle

The 4.3 release will be supported until October 15th, 2026.

Additional release information may be found on the Release Management Wiki.

Thanks 🙏

Many thanks to the 795 individuals who contributed to this release! 🚀

Johan, Chris, and the Zephyr Release Team