We are pleased to announce the release of Zephyr version 4.5.0.
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:
New architectures: Infineon TriCore and Qualcomm Hexagon
Zephyr now supports the Infineon TriCore architecture, used in AURIX automotive microcontrollers, and the Qualcomm Hexagon DSP architecture.
Multimedia Pipeline (mpipe)
The new experimental Multimedia Pipeline (mpipe) subsystem, inspired by GStreamer, provides a framework for building media applications from source, transform and sink elements linked into a zero-copy pipeline.
Networking enhancements
Optimizations across the IP stack deliver up to 21% higher TCP throughput in the zperf loopback benchmark.
The networking stack also gains several new features:
- QUIC and HTTP/3 support.
- RTP (RFC3550) stack for sending and receiving media streams over UDP.
- SSH server and client, including a shell backend.
- Model Context Protocol (MCP) server to let AI agents use tools exposed by a device.
- Gateway features: IPv4 forwarding, NAT, IPv6 router role and DHCPv6 prefix delegation.
New driver classes
Zephyr 4.5 adds several new driver APIs:
- Buzzer for passive and active buzzers driven by PWM or GPIO,
- Clock Monitor for runtime observation of clock frequency,
- DALI for the Digital Addressable Lighting Interface,
- LIN for the Local Interconnect Network automotive serial bus,
- MUX for hardware signal multiplexers, and
- Pulse IO for hardware that generates and captures timed digital edges, as needed by addressable LED strips and infrared transceivers.
Security and SBOM improvements
This release improves SBOM generation, hardening checks and cryptographic acceleration:
- SPDX 3 SBOMs that record how the image was built (Build profile), the prebuilt libraries it links, and package identifiers for vulnerability matching.
- A revamped hardening tool with CWE references and CI integration.
- Hardware-accelerated PSA Crypto on selected Silicon Labs, NXP and STM32 devices.
Simulation and testing improvements
This release extends simulated targets and test tooling:
- New host-backed native_sim peripherals, including Wi-Fi, audio, video, LEDs and host directory mounts.
- New VirtIO drivers (block, input, GPIO, I2C and SPI) for QEMU targets.
- Multi-device testing and multi-toolchain builds in Twister.
- TTCN-3 conformance test suites for the networking stack.
Debugging and diagnostics
This release adds several debugging and diagnostic tools:
- ZASSERT() for per-module and per-file assertion levels.
- Heap memory error detection with CONFIG_SYS_HEAP_SANITIZER_ASAN (native_sim) and CONFIG_SYS_HEAP_KASAN (real targets).
- New tracing features: terminal viewer, Perfetto export, shell and ITM backend.
Expanded board support
This release adds support for 178 new boards and 29 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
v4.4.0 to Zephyr v4.5.0 can be found in the separate migration guide.
Release Lifecycle
The 4.5 release will be supported until October 28th, 2027.
Additional release information may be found on the Release Management Wiki.
Thanks 🙏
Many thanks to the 1297 individuals who contributed to this release! 🚀
Tom, Brix, and the Zephyr Release Team