Announcing Zephyr 4.4.0

[MaureenHelm]

We are pleased to announce the release of Zephyr 4.4.0!

For a closer look at some of the key additions in this release, check out the announcement article on the Zephyr blog, along with its companion video.

Major enhancements with this release include:

OpenRISC support

Zephyr now supports the OpenRISC architecture.

Toolchain updates: Zephyr SDK 1.0 and C17

Zephyr 4.4 is the first release to support Zephyr SDK 1.0, with an upgraded GNU toolchain, experimental Clang/LLVM support, and multi-platform QEMU and OpenOCD host tools.

Zephyr now defaults to C17 as its minimum required C standard version.

Networking enhancements

The Wi-Fi management stack now supports Wi-Fi P2P (Wi-Fi Direct), allowing devices to discover and connect directly without a traditional access point.

The networking stack also adds support for WireGuard VPN, enabling secure, low-overhead tunneling.

USB host

Experimental USB host support has been significantly expanded with a new host-class driver framework and support for UVC cameras on Zephyr devices acting as USB hosts.

New driver classes

Zephyr 4.4 adds several new driver APIs, including:

• One-Time Programmable (OTP) memory devices for provisioning and reading permanent device data,
• A biometrics API for integrating biometric sensors such as fingerprint scanners or facial recognition systems, and
• A Wake-up Controller (WUC) API for managing wake-up sources that can bring the system out of low-power states.

Zbus async listeners and proxy agents

Zbus async listeners enable non-blocking observer callbacks via workqueues.

Zbus proxy agents extend publish-subscribe messaging across CPU and domain boundaries over IPC.

Pressure-based CPU frequency scaling

The experimental CPU frequency scaling subsystem now includes a pressure-based policy that adjusts CPU frequency according to scheduler load.

ARM Cortex-M context switching performance improvements

A new context switch implementation for ARM Cortex-M, enabled via CONFIG_USE_SWITCH, delivers significant performance improvements.

NAND flash support

A new Flash Translation Layer (FTL) disk driver (zephyr,ftl-dhara) provides wear leveling and bad block management and enables NAND flash memories to be utilized as standard disk devices.

Developer experience improvements

This release adds several new tools and improvements to development and testing workflows:

• A new dashboard consolidates build information such as RAM and ROM footprint, Devicetree configuration, subsystem initialization levels, and more in a single report.
• A new display driver for QEMU targets simplifies development of display-based applications in environments where the native simulator is unavailable.
• A new heap hardening mechanism (CONFIG_SYS_HEAP_HARDENING) provides multiple levels of runtime protection against heap corruption.
• New scope-based cleanup helpers provide RAII/defer-style automatic cleanup in C when leaving scope.
• The new ztest benchmarking framework provides a standardized way to create cycle-accurate benchmarks, with automated data collection, overhead compensation, and statistical reporting.

Expanded board support

This release adds support for 121 new boards and 31 new shields.

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
v4.3.0 to Zephyr v4.4.0 can be found in the separate migration guide.

Release Lifecycle

The 4.4 release will be supported until April 12th, 2027.

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

Thanks 🙏

Many thanks to the 931 individuals who contributed to this release! 🚀

Maureen, Stephanos, and the Zephyr Release Team

[pica111]

Hey everyone, I’m happy to jump in and handle if it hasn't been assigned yet. Just let me know!