Blog

Long-Term Support, Short-Term Freeze — Zephyr Podcast #052

By September 25, 2026No Comments

Join Discord // #podcast at https://chat.zephyrproject.org!

Subscribe to the podcast on your favorite platform:

The summary below was automatically generated using the assistance of AI tools.

Episode Summary

  • A Week at ROSCon: Benjamin recorded from Toronto after his first ROSCon. Hundreds of attendees but only two tracks, which makes for a dense and very technical program, and a reminder that Zephyr could do more Zephyr 101 content at ZDS. His ten-minute talk made the case for a small, portable real-time OS next to the big GPUs doing the planning: you still need small brains at the far edge. The expo floor was robot arms and humanoids, and the talks he enjoyed most were about agricultural robots picking fruit with the care of a human hand. It was also the first in-person conference where the AI conversations were practical tips rather than hype. Plenty of the same people will be at ZDS.
  • Canonical’s Zephyr LTS: Canonical announced Zephyr 26.04 LTS ahead of Embedded World North America, named Ubuntu-style and backed by up to 15 years of security maintenance, with LTS releases every two years and interim releases every six months. That is longer than Zephyr has existed. Long-term support is a lot more than backporting: in 15 years the CMake you build with today will be gone from every repository, and upstream backports already run into CI drift. The announcement also covers containerized development environments. Upstream LTS still matters, since backporting in Zephyr is maintainer-driven and the maintainers are best placed to judge how a fix should apply.
  • The Docs Assistant: The AI assistant on the Zephyr documentation came up at ROSCon, where developers building drones on Zephyr said it was what got them over the learning curve. The most common questions are about the build system and about MCUboot and OTA updates, both of which will feed into the Documentation Working Group and the documentation BoF at ZDS. It is also available as an MCP server, so your editor or coding agent can ask it instead of grepping a local clone.
  • Raspberry Pi Locks RAM: Raspberry Pi now ties boards to their factory RAM capacity in firmware, after resellers bought low-memory boards, swapped in chips of dubious origin and sold them on as higher-spec models. The motivation is understandable, even if it is a little sad that it came to this.
  • More mpipe: Following last week’s merge of the subsystem, mpipe gains player utilities for play, pause, stop and replay from the shell, with keystroke shortcuts, and a base plugin set with queue, tee and capsfilter elements. Think of mpipe as GStreamer for Zephyr.
  • A Camera for native_sim: A native_sim video source that reads raw frames from a pipe on the host, typically fed by ffmpeg: a test pattern, a video file, or a webcam. Take whatever Big Buck Bunny file you have and push it through a Zephyr video pipeline without any hardware.
  • Flash on the Host: A semihosted flash driver gives a device under debug a flash area backed by a file on the host machine. This runs on real targets with a probe attached, not just native_sim, and the file can be pre-populated, for example for MCUboot. Handy for exercising filesystem or wear behaviour without touching the device’s own flash.
  • LIN: Just ahead of the freeze, a LIN driver API. LIN is the simpler, cheaper bus that sits underneath CAN in a vehicle, connecting small satellite boards such as switch panels or motor controllers. The first implementation is on Renesas RA, and the sample drives an automotive RGB LED driver over LIN.
  • FIDO2 Over Bluetooth: FIDO2 support arrived in Zephyr this cycle, and it now has a BLE transport, so a security key can authenticate without being plugged in. The PR also shows that devicetree lets you reference a node by path instead of by label. It works. Please don’t.
  • DMA2D on STM32: DMA2D and LVGL direct rendering are now enabled across the STM32 families that have the peripheral, including F4, F7, H7, L4 and U5.
  • A 32-bit ADC: A driver for the TI ADS1262 and ADS1263, 32-bit sigma-delta ADCs with a programmable gain amplifier and an internal reference, aimed at bridge measurements such as load cells. At around 25 euros, it costs more than the microcontroller reading it.
  • A DSI to HDMI Bridge: A driver for the Analog Devices ADV7535, which bridges MIPI DSI to HDMI. Fabio went looking for a pinout in the public datasheet and came back empty-handed, so if anyone at ADI is listening, a few more pages would go a long way now that there is an open source driver.
  • Assertions Per Module: ZASSERT, from Måns Ansgariusson, reworks assertions to work more like logging. Instead of one global switch, each file belongs to a group that can be off, on with location only, or verbose, with a Kconfig template for defining groups. Maintainers can test their own subsystem with assertions enabled without inflating the flash footprint of the whole application.
  • Networking Conformance: TTCN-3 conformance suites now test the network stack against the standards: TCP, ARP, DHCPv4, IPv6 neighbor discovery, DNS, mDNS, DNS-SD, CoAP, MQTT and the SNTP client, 78 test cases in all. They are meant to run nightly rather than on every pull request, and can be run locally with open source TTCN-3 tooling.
  • An SNTP Server: An SNTP server library, for handing out time to other nodes on a network without the weight of a full NTP implementation.
  • Wi-Fi in native_sim: A native_sim Wi-Fi driver that uses the host’s nl80211 against Linux’s mac80211_hwsim simulated radios, so Zephyr’s Wi-Fi APIs and supplicant can be exercised without a radio.
  • TCP Selective ACKs: TCP now reports received data with SACK, so a receiver can say exactly which segments are missing instead of only how far it got. On an i.MX RT1170 EVK over a gigabit link with about 0.3% loss, throughput went from around 73 to around 130 Mbps. It is on by default and can be turned off.
  • Boards: The Sipeed Tang Mega 138K Pro Dock, a Gowin FPGA module with a hard RISC-V core on a carrier with PCIe Gen3 x4, two SFP+ cages, gigabit Ethernet, HDMI/DVI and MIPI CSI.
  • Two Deadlines on Monday: The 4.5 feature freeze lands on Monday 28 September, so any open pull request that needs a nudge or a rebase needs it this weekend. The same day, the embedded world Conference call for papers closes. The conference runs 16 to 18 March 2027 and usually has a dedicated Zephyr track.