1. Installing flutter-elinux

2. Building Flutter apps

2-1. Self-build

Build in release mode:

$ flutter-elinux create sample
$ cd sample
$ flutter-elinux build elinux

Build in debug mode:

$ flutter-elinux create sample
$ cd sample
$ flutter-elinux build elinux --debug

$ flutter-elinux build bundle --asset-dir=./bundle/data/flutter_assets
$ cp <path_to_flutter_sdk_install>/bin/cache/artifacts/engine/elinux-common/icu/icudtl.dat ./bundle/data

2-2. Cross-build for Arm64 targets on x64 hosts

2-3. Cross-build for Arm64 targets on x64 hosts manually

Build in release mode:

$ flutter-elinux create sample
$ cd sample
# Path to Flutter SDK
$ export FLUTTER_SDK=/opt/flutter-elinux/flutter
# Package name of the build target Flutter app
$ export APP_PACKAGE_NAME=sample
# The build data.
$ export RESULT_DIR=build/linux-embedded-arm64
$ export BUILD_MODE=release
$ mkdir -p .dart_tool/flutter_build/flutter-embedded-linux
$ mkdir -p ${RESULT_DIR}/${BUILD_MODE}/bundle/lib/
$ mkdir -p ${RESULT_DIR}/${BUILD_MODE}/bundle/data/
# You need to use `gen_snapshot` for cross-building
$ mkdir -p ${FLUTTER_SDK}/bin/cache/artifacts/engine/linux-arm64-release/clang_x64
$ cp <path_to_your_working_directory_to_build_engine>/src/out/linux_release_arm64/clang_x64/gen_snapshot \
 ${FLUTTER_SDK}/bin/cache/artifacts/engine/linux-arm64-release/clang_x64/gen_snapshot
# Build Flutter assets.
$ flutter build bundle --asset-dir=${RESULT_DIR}/${BUILD_MODE}/bundle/data/flutter_assets
$ cp ${FLUTTER_SDK}/bin/cache/artifacts/engine/linux-x64/icudtl.dat \
 ${RESULT_DIR}/${BUILD_MODE}/bundle/data/
# Build kernel_snapshot.
$ ${FLUTTER_SDK}/bin/cache/dart-sdk/bin/dart \
 --verbose \
 --disable-dart-dev ${FLUTTER_SDK}/bin/cache/artifacts/engine/linux-x64/frontend_server.dart.snapshot \
 --sdk-root ${FLUTTER_SDK}/bin/cache/artifacts/engine/common/flutter_patched_sdk_product/ \
 --target=flutter \
 --no-print-incremental-dependencies \
 -Ddart.vm.profile=false \
 -Ddart.vm.product=true \
 --aot \
 --tfa \
 --packages .dart_tool/package_config.json \
 --output-dill .dart_tool/flutter_build/flutter-embedded-linux/app.dill \
 --depfile .dart_tool/flutter_build/flutter-embedded-linux/kernel_snapshot.d \
 package:${APP_PACKAGE_NAME}/main.dart
# Build AOT image.
$ ${FLUTTER_SDK}/bin/cache/artifacts/engine/linux-arm64-release/clang_x64/gen_snapshot \
 --deterministic \
 --snapshot_kind=app-aot-elf \
 --elf=.dart_tool/flutter_build/flutter-embedded-linux/libapp.so \
 --strip \
 .dart_tool/flutter_build/flutter-embedded-linux/app.dill
$ cp .dart_tool/flutter_build/flutter-embedded-linux/libapp.so ${RESULT_DIR}/${BUILD_MODE}/bundle/lib/