meta-flutter

Yocto Layer for Google Flutter related projects.

Recommended development flow:

• Create flutter workspace using ./tools/setup_flutter_workspace.py
• Debug and validate application on host using flutter-auto, AGL QEMU, or Linux GTK.
• Create Yocto Recipe for your Flutter application using flutter-gallery-* or one of the many app recipes as the template. Nested projected are supported using FLUTTER_APPLICATION_PATH. Passing Dart defines are done with FLUTTER_EXTRA_BUILD_ARGS.
• Add your app, and selected embedder to your release image. The flutter engine will be implicitly added to the image.
• Image device

Layers dependencies

• meta-clang

Clang generates smaller runtime images, and is used by Google to build the the flutter engine for Android and iOS. Changing toolchains should be avoided, as this would provide a path with little to no test milage.

Overview

Target BSP is expected to have a GPU with OpenGLES v2.0+ support.
If you selecting a part go with v3.0+, ideally one with Vulkan support.

Notes

• There are no OSS Linux embedders (that I am aware of that currently support software rendering). The engine does support it.

• flutter-auto is the agl branch of https://github.com/toyota-connected/ivi-homescreen the main branch has moved to quarterly releases, the agl branch is directly supporting AGL development work.

CI Jobs

• kirkstone-agl-renesas-m3.yml - Renesas M3 build. Time boxed GPU driver (30 minutes?). AGL canaray build.

• kirkstone-agl-x86_64.yml - meta-flutter QEMU image used with tools/seup_flutter_workspace.py. Test build for AGL downstream work.

• kirkstone-imx8mmevk.yml - NXP imx8mmevk baseline Wayland image.

• kirkstone-linux-dummy.yml - Tests all recipes in the layer without a dummy Linux kernel (save build time).

• kirkstone-qc-dragonboard.yml - DB410C and DB820C Wayland images.

• kirkstone-rpi-zero2w-64.yml - RPI Zero2W Wayland image (flutter-auto). Farily full featured with Network Manager, BT, WiFi, etc.

• kirkstone-stm32mp15.yml - eglfs (flutter-pi) st-core-image+SDK and wayland (flutter-auto) st-core-image+SDK.

Notes: CI job sstate is cleared between builds for all meta-flutter recipes; clean builds.

General

Targets flutter-engine-* is known to work on

• AGL QEMU images - aarch64/x86_64
• Intel icore7-64
• NVIDIA Nano, Xavier Dev Kits - aarch64
• NXP iMX7 (caveats), iMX8
• Qualcomm DragonBoard DB410c, DB820, SA6155P, SA8xxx - aarch64
• Raspberry Pi 3 / Compute - aarch64 / armv7hf
• Raspberry Pi 4 / Compute - aarch64
• Raspberry Pi ZeroW / Zero2W - aarch64
• Renesas R-Car M3/H3 - aarch64
• STM32MP157x - cortexa7t2hf
• etc

Include the Flutter SDK into Yocto SDK

Add to local.conf file:

TOOLCHAIN_HOST_TASK:append = " nativesdk-flutter-sdk"

Then run:

bitbake <image name> -c populate_sdk

Note: when using SDK you may need to add the following after installation:

$ export SDK_ROOT=<install folder>/sysroots/x86_64-nodistrosdk-linux/usr/share/flutter/sdk
$ git config --global --add safe.directory $SDK_ROOT

General Yocto Notes

When building on systems with GCC version > than uninative in Yocto distro add the following to conf/local.conf

INHERIT:remove = "uninative"

Flutter Workspace Automation

Please visit here for how to setup Flutter workspace automatically.