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Summit

Device Tree for Android

2011-11-01 10:00..10:45 in Grand Sierra G

In this session we will talk about device tree on Android.

Description

Linaro has a goal of creating a single runtime image that can run across SoC hardware. The Android team is supporting this effort by using a common Linaro Android tree as a base for all our trees and working to unify all the SoC trees into one. Once unification is done, device tree will allow us to re-factor basic support that was once compile time configurable into runtime configurable options. Having this support on Android early will help us towards this goal and ensure that our kernels can boot as device tree becomes more widespread.

Linaro Kernel WG and OCTO have worked on getting Device Tree support accepted into the mainline kernel, and initial support for all recent member SoCs is available. Ubuntu images are already using Device Tree; the next logical step is to make Device Tree be used by default in Linaro's Android LEBs.

This feature requires improvements to the Linaro Android builds to enable production of binary flattened device trees as part of the platform build. Also required is updating installation tools and u-boot to ensure that the FDT is used during the boot process as needed. Additional fixes in Android-specific kernel and driver code may be required.

Acceptance Criteria

  1. LEB Android builds come with u-boot and kernel that have device tree support enabled
  2. LEB Android builds include appropriate flattened device tree in the 'boot' artifact
  3. Installing LEB images using linaro-android-media-create will yield an image with device tree being used by u-boot and kernel

See https://linaro.papyrs.com/page/4112/ANDROID2011-FDT-LEB for the original description.

Agenda

TBD

Goal of this Session

To brainstorm and generate concrete work items for landing device tree in all LEBs.