Device Tree Tools, Validation, and Troubleshooting

The Linux Plumbers 2015 Device Tree Tools, Validation, and Troubleshooting track focuses on tools (programs and scripts), techniques, and core support to enable creation of correct device trees and to support troubleshooting and debugging of incorrect device trees, drivers, and subsystems.

The tools encompass static (build and pre-boot) and dynamic (boot and run-time) environments.

Areas of interest include

  • inspection
  • verification and validation
  • troubleshooting
  • debugging
  • core support for debugging
  • unit tests
  • designing and implementing drivers for effective debugging
  • impact of overlays (boot and run-time updates to the device tree)
  • bindings
  • documentation

Topics unrelated to the overall track but of current Device Tree interest may be accepted if there is available time

  • ordering of device creation and driver binding

Key Attendees

“y” == expect to attend
conflicts are listed after ”—”

  • y Rob Herring (device tree maintainer, bindings) — Android mini conf
  • y Grant Likely (device tree maintainer)
  • Tomasz Figa (validation)
  • y Benoit Cousson (validation)
  • Fabien Parent (validation)
  • Stephen Warren (validation)
  • y David Gibson (dtc) — KVM Forum
  • other libfdt and dtc contributors tbd
  • y Pantelis Antoniou (overlays)
  • y Mark Rutland (bindings)
  • Pawel Moll (bindings)
  • Ian Campbell (bindings)
  • Kumar Gala (bindings)
  • y Frank Rowand
  • Thomas Petazzoni
  • n Geert Uytterhoeven
  • Olof Johansson
  • n Arnd Bergmann
  • y Matt Porter
  • y Jon Loeliger
  • y Mark Rutland
  • y Gaurav Minocha
  • y Guenter Roeck
  • etc…

Proposed Topics (Tentative)

These are suggestions from email discussion, not yet a proposed schedule…

  • Supported and not supported overlay usecases
    • I guess Kernel-driven overlay application (it's been called “quirks” elsewhere) would fall under this? It's rather scary, and would need fairly strict rules to be feasible and remain maintainable, which is going to limit where it can be used.
  • Tools for overlays - I think overlays has created new challenges in validation and a need for new tools.
    • How to test an overlay applies?
  • Generating a dtb from dts + overlay dts.
  • Generating an overlay from a diff of old and new dts (overlay as a way to update old dtbs)
  • Shrinking the binding review fire hose. How to improve binding documentation structure and review.
  • Standardizing Android dtb handling.
    • If people are going to package a kernel and DTB together, it would be nice if they could at least be easily decomposed (using something like FIT).
  • Appended DTB for arm64? Not liked by upstream, but already in use.
  • Clean up of existing hardware-specific bindings to conform to the generic bindings, working dts files in the kernel tree, and bring consistency to the documentation style/syntax.
  • Create a qemu instance from a device tree description.
  • Topic N - TBD
  • etc…


The schedule is still under construction and should be considered very fluid.

The schedule of the 2015 Tracing Plumbers Microconference is as follows. Note presentation slides can be found on the Plumbers page by following the links to the abstracts:

  • Overlays (title TBD) - Pantelis Antoniou, maybe additional
    • The below may be incorporated or may be separate sessions
      • new tools needed; test, validation, generating
      • supported and not supported usecases
      • how overlays are used at Juniper - Guenter Roeck
  • Future direction of device tree (title TBD) - Pantelis Antoniou
  • existing tools, what they do, how to find them (title TBD) - Frank Rowand
  • tools that have been proposed by have not gained traction - Frank Rowand, maybe additional
    • generate config from DT source
    • build version embedded in .dtb
    • more…
  • binding review firehose (title TBD) - TBD
  • Clean up of existing hardware-specific bindings to conform to the generic bindings, working dts files in the kernel tree, and bring consistency to the documentation style/syntax - maybe twist Matt Porter's arm
  • standardized Android dtb handling (maybe belongs in the Android track?) - TBD
  • Appended DTB for ARM64 - TBD
  • what documentation, tutorials exist? what is needed? - TBD

Discussion notes

This is a good place to record notes from your session. All too often, if notes were not written down, the session might as well not have happened.


Runner: Frank Rowand

2015/device_tree_tools_validation_and_trouble_shooting.txt · Last modified: 2015/06/22 01:46 by
Except where otherwise noted, content on this wiki is licensed under the following license:CC Attribution-Noncommercial-Share Alike 3.0 Unported
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki