Device Tree Overlays


One Line Summary

Device Tree Overlays overview and use cases


Device Tree Overlays are now in the mainline kernel. This session will cover what they are, how they are used.

As part of this session I will examine device tree overlays, device tree changeset, the phandle resolution mechanism, overlay overlap removal checks and finally device tree variants (or quirks).

The Juniper use case will be discussed:

At Juniper, we use devicetree overlays to manage a variety of cards which can be inserted and removed at runtime.

In this session, I will describe the basic system architecture, our requirements, and why we decided to use devicetree overlays to meet those requirements. I will also dive into the actual implementation of our card management framework in the Linux kernel, and explore some of the limitations of the current devicetree overlay code.


Device Tree, Overlays, changesets, device tree variants, device tree quirks

Presentation Materials



  • Pantelis Antoniou

    Konsulko Group


    Pantelis Antoniou has been an active Linux kernel developer for more than 13 years. Has brought to market a lot of Linux based products, passing through companies like Texas Instruments, Mentor Graphics, NVIDIA before ending up with Konsulko Group.He gets to make Linux play nice with cars among other. He has already been a speaker in two previous ELC’s. His current interests are planting Device Trees on everything, hypervisors and asymmetric processing.

  • Guenter Roeck

    Juniper Networks


    Guenter Roeck has been an active Linux kernel developer since 2008. In the Linux kernel community he maintains the hardware monitoring subsystem and helps out with the watchdog subsystem. He is also involved in Linux kernel testing and maintains an automated testing framework from servers running at his home.
    Guenter has worked for Cisco Systems, Ericsson, and other networking companies prior to joining Juniper Networks as a Linux kernel expert.