[v2] package/flutter-engine: new package

diff --git a/DEVELOPERS b/DEVELOPERS
index 45197c80ee..57abe36fc9 100644
--- a/DEVELOPERS
+++ b/DEVELOPERS
@@ -31,6 +31,7 @@  F:	package/firewalld/
 
 N:	Adam Duskett <adam.duskett@amarulasolutions.com>
 F:	package/depot-tools/
+F:	package/flutter-engine/
 F:	package/flutter-sdk-bin/
 
 N:	Adam Heinrich <adam@adamh.cz>
diff --git a/package/Config.in b/package/Config.in
index 15b1866630..6f385ff697 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -1580,6 +1580,7 @@  menu "Graphics"
 	source "package/exempi/Config.in"
 	source "package/exiv2/Config.in"
 	source "package/fltk/Config.in"
+	source "package/flutter-engine/Config.in"
 	source "package/fontconfig/Config.in"
 	source "package/freetype/Config.in"
 	source "package/gd/Config.in"
diff --git a/package/flutter-engine/0001-disable-pre-canned-sysroot.patch b/package/flutter-engine/0001-disable-pre-canned-sysroot.patch
new file mode 100644
index 0000000000..953705e33b
--- /dev/null
+++ b/package/flutter-engine/0001-disable-pre-canned-sysroot.patch
@@ -0,0 +1,32 @@ 
+From 49a14e693124dc34f2cccbfb755d01a1198aa6bf Mon Sep 17 00:00:00 2001
+From: Joel Winarske <joel.winarsk@gmail.com>
+Date: Wed, 19 Jul 2023 15:24:22 -0700
+Subject: [PATCH] disable pre-canned sysroot
+
+Override should be enabled if a custom sysroot using --target-sysroot is
+specified. If --target-sysroot is not set, then it should default to the
+pre-canned sysroot.
+
+Upstream: https://github.com/flutter/flutter/issues/123073
+Signed-off-by: Joel Winarske <joel.winarsk@gmail.com>
+Signed-off-by: Adam Duskett <adam.duskett@amarulasolutions.com>
+---
+ build/config/sysroot.gni | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/build/config/sysroot.gni b/build/config/sysroot.gni
+index 7987e519d..1de694263 100644
+--- a/build/config/sysroot.gni
++++ b/build/config/sysroot.gni
+@@ -14,7 +14,7 @@ declare_args() {
+ 
+   # Whether to use the default sysroot when building for Linux, if an explicit
+   # sysroot isn't set.
+-  use_default_linux_sysroot = true
++  use_default_linux_sysroot = false
+ }
+ 
+ if (current_toolchain == default_toolchain && target_sysroot != "") {
+-- 
+2.41.0
+
diff --git a/package/flutter-engine/0002-remove-explicit-x11-dependency.patch b/package/flutter-engine/0002-remove-explicit-x11-dependency.patch
new file mode 100644
index 0000000000..23d7ec9b06
--- /dev/null
+++ b/package/flutter-engine/0002-remove-explicit-x11-dependency.patch
@@ -0,0 +1,33 @@ 
+From b1a5db9318ca33a03f2700758d5debad907d21b6 Mon Sep 17 00:00:00 2001
+From: Joel Winarske <joel.winarsk@gmail.com>
+Date: Wed, 19 Jul 2023 15:26:40 -0700
+Subject: [PATCH] remove explicit x11 dependency
+
+This is superfluous and may conflict with the actual rendering system used in
+gtk3 (e.g. wayland.)
+
+Upstream: https://github.com/flutter/flutter/issues/123073
+Signed-off-by: Joel Winarske <joel.winarske@gmail.com>
+Signed-off-by: Adam Duskett <adam.duskett@amarulasolutions.com>
+---
+ flutter/shell/platform/linux/config/BUILD.gn | 4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/flutter/shell/platform/linux/config/BUILD.gn b/flutter/shell/platform/linux/config/BUILD.gn
+index da0ac056b..70c7a0ea1 100644
+--- a/flutter/shell/platform/linux/config/BUILD.gn
++++ b/flutter/shell/platform/linux/config/BUILD.gn
+@@ -5,10 +5,6 @@
+ import("//build/config/linux/pkg_config.gni")
+ import("//flutter/shell/platform/glfw/config.gni")
+ 
+-pkg_config("x11") {
+-  packages = [ "x11" ]
+-}
+-
+ pkg_config("gtk") {
+   packages = [ "gtk+-3.0" ]
+ }
+-- 
+2.41.0
+
diff --git a/package/flutter-engine/0003-fix-toolchain-paths.patch b/package/flutter-engine/0003-fix-toolchain-paths.patch
new file mode 100644
index 0000000000..ba5d5f8023
--- /dev/null
+++ b/package/flutter-engine/0003-fix-toolchain-paths.patch
@@ -0,0 +1,40 @@ 
+From ca175ef5bf7f96db57fb5aa562602dc424fab81c Mon Sep 17 00:00:00 2001
+From: Joel Winarske <joel.winarsk@gmail.com>
+Date: Sun, 5 Mar 2023 10:43:02 -0800
+Subject: [PATCH] fix toolchain paths
+
+Flutter includes a copy of clang which is required to build. However, by
+default, build/toolchain/custom/BUILD.gn attempts to use several gcc utilities
+such as ar, readelf, nm, and strip. Change these to the proper llvm provided
+utility.
+
+Upstream: https://github.com/flutter/flutter/issues/123073
+
+Signed-off-by: Joel Winarske <joel.winarsk@gmail.com>
+Signed-off-by: Adam Duskett <adam.duskett@amarulasolutions.com>
+---
+ build/toolchain/custom/BUILD.gn | 4 +++++------
+ 1 file changed, 5 insertions(+), 6 deletions(-)
+
+diff --git a/build/toolchain/custom/BUILD.gn b/build/toolchain/custom/BUILD.gn
+index 65b1623..8b3f6f8 100644
+--- a/build/toolchain/custom/BUILD.gn
++++ b/build/toolchain/custom/BUILD.gn
+@@ -12,11 +12,11 @@ toolchain("custom") {
+   # these values in our scope.
+   cc = "${toolchain_bin}/clang"
+   cxx = "${toolchain_bin}/clang++"
+-  ar = "${toolchain_bin}/${custom_target_triple}-ar"
++  ar = "${toolchain_bin}/llvm-ar"
+   ld = "${toolchain_bin}/clang++"
+-  readelf = "${toolchain_bin}/${custom_target_triple}-readelf"
+-  nm = "${toolchain_bin}/${custom_target_triple}-nm"
+-  strip = "${toolchain_bin}/${custom_target_triple}-strip"
++  readelf = "${toolchain_bin}/llvm-readelf"
++  nm = "${toolchain_bin}/llvm-nm"
++  strip = "${toolchain_bin}/llvm-strip"
+ 
+   target_triple_flags = "--target=${custom_target_triple}"
+   sysroot_flags = "--sysroot ${custom_sysroot}"
+-- 
+2.39.2
diff --git a/package/flutter-engine/0004-pkg-config.py-do-not-prepend-sysroot-path.patch b/package/flutter-engine/0004-pkg-config.py-do-not-prepend-sysroot-path.patch
new file mode 100644
index 0000000000..a31be7d77f
--- /dev/null
+++ b/package/flutter-engine/0004-pkg-config.py-do-not-prepend-sysroot-path.patch
@@ -0,0 +1,37 @@ 
+From 51e8fed854fd9d373bb9b20d7ed8e7cf6ef12312 Mon Sep 17 00:00:00 2001
+From: Adam Duskett <adam.duskett@amarulasolutions.com>
+Date: Wed, 19 Jul 2023 11:48:59 -0700
+Subject: [PATCH] pkg-config.py: do not prepend sysroot path
+
+Buildroot uses the standard PKG_CONFIG_SYSROOT_DIR variable, so what the
+pkg-config.py script is doing doesn't make sense. There is no need to prepend
+the sysroot, and flutter should let pkg-config use the PKG_CONFIG_SYSROOT_DIR
+variable.
+
+Without this patch, the pkg-config.py script double prepends the sysroot path.
+IE: output/host/.../sysroot/output/host/.../sysroot
+
+Upstream: https://github.com/flutter/flutter/issues/132152
+Signed-off-by: Adam Duskett <adam.duskett@amarulasolutions.com>
+---
+ build/config/linux/pkg-config.py | 4 +---
+ 1 file changed, 1 insertion(+), 3 deletions(-)
+
+diff --git a/build/config/linux/pkg-config.py b/build/config/linux/pkg-config.py
+index b4a6aff17..44ffdcaea 100644
+--- a/build/config/linux/pkg-config.py
++++ b/build/config/linux/pkg-config.py
+@@ -207,9 +207,7 @@ def main():
+   all_flags = flag_string.strip().split(' ')
+ 
+ 
+-  sysroot = options.sysroot
+-  if not sysroot:
+-    sysroot = ''
++  sysroot = ''
+ 
+   includes = []
+   cflags = []
+-- 
+2.41.0
+
diff --git a/package/flutter-engine/Config.in b/package/flutter-engine/Config.in
new file mode 100644
index 0000000000..aad0fc6108
--- /dev/null
+++ b/package/flutter-engine/Config.in
@@ -0,0 +1,56 @@ 
+# Flutter includes a vender copy of clang which is mandatory to use for
+# compiling. These are the supported architectures.
+config BR2_PACKAGE_FLUTTER_ENGINE_ARCH_SUPPORTS
+	bool
+	default y if BR2_aarch64
+	default y if BR2_arm && !BR2_ARM_CPU_ARMV4 && !BR2_ARM_CPU_ARMV5
+	default y if BR2_i386
+	default y if BR2_x86_64
+
+config BR2_PACKAGE_FLUTTER_ENGINE
+	bool "flutter-engine"
+	depends on BR2_PACKAGE_FLUTTER_ENGINE_ARCH_SUPPORTS
+	depends on BR2_TOOLCHAIN_USES_GLIBC
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_5
+	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL # pthreads
+	depends on BR2_INSTALL_LIBSTDCPP
+	depends on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735 # std::shared_future
+	depends on !BR2_STATIC_LIBS
+	depends on BR2_USE_WCHAR # std::wstring
+	depends on BR2_HOST_GCC_AT_LEAST_5
+	depends on BR2_PACKAGE_HAS_LIBGL || BR2_PACKAGE_HAS_LIBGLES
+	select BR2_PACKAGE_FREETYPE
+	select BR2_PACKAGE_HOST_DEPOT_TOOLS
+	select BR2_PACKAGE_ZLIB
+	help
+	  Flutter is Google's SDK for crafting beautiful, fast user
+	  experience for mobile, web, and desktop from a single
+	  codebase. Flutter works with existing code, is used by
+	  developers and organizations around the world, and is
+	  free and open source.
+
+	  The Flutter Engine is a portable runtime for hosting
+	  Flutter applications. It implements Flutter's core
+	  libraries, including animation and graphics, file and
+	  network I/O, accessibility support, plugin architecture,
+	  and a Dart runtime and compile toolchain. Most developers
+	  will interact with Flutter via the Flutter Framework,
+	  which provides a modern, reactive framework, and a rich
+	  set of platform, layout and foundation widgets.
+
+	  https://github.com/flutter/engine
+
+comment "flutter-engine needs an OpenGL or OpenGLES backend"
+	depends on BR2_PACKAGE_FLUTTER_ENGINE_ARCH_SUPPORTS
+	depends on !BR2_PACKAGE_HAS_LIBGL && !BR2_PACKAGE_HAS_LIBGLES
+
+comment "flutter-engine needs a glibc toolchain w/ wchar, C++, gcc >= 5, dynamic library, host gcc >= 5, NPTL"
+	depends on BR2_PACKAGE_FLUTTER_ENGINE_ARCH_SUPPORTS
+	depends on !BR2_TOOLCHAIN_USES_GLIBC || !BR2_TOOLCHAIN_HAS_THREADS_NPTL \
+		|| !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_GCC_AT_LEAST_5 \
+		|| BR2_STATIC_LIBS || !BR2_USE_WCHAR \
+		|| !BR2_HOST_GCC_AT_LEAST_5
+
+comment "flutter-engine needs a toolchain not affected by GCC bug 64735"
+	depends on BR2_PACKAGE_FLUTTER_ENGINE_ARCH_SUPPORTS
+	depends on BR2_TOOLCHAIN_HAS_GCC_BUG_64735
diff --git a/package/flutter-engine/dot-gclient b/package/flutter-engine/dot-gclient
new file mode 100644
index 0000000000..168e9a368d
--- /dev/null
+++ b/package/flutter-engine/dot-gclient
@@ -0,0 +1,16 @@ 
+# This file is taken from the output of meta-flutter/lib/gn.py
+
+solutions = [{
+    "managed": False,
+    "name": "src/flutter",
+    "url": "https://github.com/flutter/engine.git@!FLUTTER_VERSION!",
+    "custom_vars": {
+        "download_android_deps": False,
+        "download_windows_deps": False,
+        "download_linux_deps": False
+    },
+    "custom_deps": {
+        "src/third_party/dart/third_party/pkg/tools":
+        "https://dart.googlesource.com/tools.git@unified_analytics-v1.1.0"
+    }
+}]
diff --git a/package/flutter-engine/flutter-engine.mk b/package/flutter-engine/flutter-engine.mk
new file mode 100644
index 0000000000..6f32fc0ed6
--- /dev/null
+++ b/package/flutter-engine/flutter-engine.mk
@@ -0,0 +1,238 @@ 
+################################################################################
+#
+# flutter-engine
+#
+################################################################################
+
+# Flutter-engine has a release on the GitHub page. However, that release is
+# only for Google. Its intended purpose is for the gclient tool provided by
+# Google in their depot-tools package. To use the source code, we must use
+# gclient to download the flutter-engine source code along with several other
+# projects. Unfortunately, the Buildroot download system does not have the
+# capability of using gclient, and considering this package is the only
+# package that uses gclient, we side-step the entire download process and
+# perform the following steps if a tarball does not exist already:
+#
+#  - Copy the pre-made gclient config file to a temporary scratch directory.
+#  - Run gclient sync to generate a source directory with the proper
+#    flutter-engine source code in the correct places.
+#  - Create a source tarball.
+#  - Copy the source tarball to the $(FLUTTER_ENGINE_DL_DIR) directory.
+#
+# There is no hash provided, as the gn binary (used for configuration) relies
+# on the .git directories. As such, a reproducible tarball is not possible.
+FLUTTER_ENGINE_VERSION = 3.10.6
+
+# There is nothing for Buildroot to download. This is handled by gclient.
+FLUTTER_ENGINE_SITE =
+FLUTTER_ENGINE_SOURCE =
+FLUTTER_ENGINE_LICENSE = BSD-3-Clause
+FLUTTER_ENGINE_LICENSE_FILES = LICENSE
+FLUTTER_ENGINE_TARBALL_PATH = $(FLUTTER_ENGINE_DL_DIR)/flutter-$(FLUTTER_ENGINE_VERSION).tar.gz
+FLUTTER_ENGINE_INSTALL_STAGING = YES
+FLUTTER_ENGINE_DOWNLOAD_DEPENDENCIES = host-depot-tools
+FLUTTER_ENGINE_DEPENDENCIES = \
+	host-flutter-sdk-bin \
+	host-ninja \
+	host-pkgconf \
+	freetype \
+	zlib
+
+# Dispatch all architectures of flutter
+# FLUTTER_ENGINE_TARGET_TRIPPLE must match the directory name found in
+# buildtools/linux-x64/clang/lib/clang/*/lib
+ifeq ($(BR2_i386),y)
+FLUTTER_ENGINE_TARGET_ARCH = x86
+FLUTTER_ENGINE_TARGET_TRIPPLE = i386-unknown-linux-gnu
+else ifeq ($(BR2_x86_64),y)
+FLUTTER_ENGINE_TARGET_ARCH = x64
+FLUTTER_ENGINE_TARGET_TRIPPLE = x86_64-unknown-linux-gnu
+else ifeq ($(BR2_arm)$(BR2_armeb),y)
+FLUTTER_ENGINE_TARGET_ARCH = arm
+FLUTTER_ENGINE_TARGET_TRIPPLE = armv7-unknown-linux-gnueabihf
+else ifeq ($(BR2_aarch64),y)
+FLUTTER_ENGINE_TARGET_ARCH = arm64
+FLUTTER_ENGINE_TARGET_TRIPPLE = aarch64-unknown-linux-gnu
+endif
+
+ifeq ($(BR2_ENABLE_RUNTIME_DEBUG),y)
+FLUTTER_ENGINE_RUNTIME_MODE=debug
+else
+FLUTTER_ENGINE_RUNTIME_MODE=release
+endif
+
+FLUTTER_ENGINE_BUILD_DIR = \
+	$(@D)/out/linux_$(FLUTTER_ENGINE_RUNTIME_MODE)_$(FLUTTER_ENGINE_TARGET_ARCH)
+
+FLUTTER_ENGINE_INSTALL_FILES = libflutter_engine.so
+
+# Flutter engine includes a bundled patched clang that must be used for
+# compiling or else there are linking errors.
+FLUTTER_ENGINE_CLANG_PATH = $(@D)/buildtools/linux-x64/clang
+
+FLUTTER_ENGINE_CONF_OPTS = \
+	--clang \
+	--embedder-for-target \
+	--linux-cpu $(FLUTTER_ENGINE_TARGET_ARCH) \
+	--no-build-embedder-examples \
+	--no-clang-static-analyzer \
+	--no-enable-unittests \
+	--no-goma \
+	--no-prebuilt-dart-sdk \
+	--no-stripped \
+	--runtime-mode $(FLUTTER_ENGINE_RUNTIME_MODE) \
+	--target-os linux \
+	--target-sysroot $(STAGING_DIR) \
+	--target-toolchain $(FLUTTER_ENGINE_CLANG_PATH) \
+	--target-triple $(FLUTTER_ENGINE_TARGET_TRIPPLE)
+
+ifeq ($(BR2_arm)$(BR2_armeb),y)
+FLUTTER_ENGINE_CONF_OPTS += \
+	--arm-float-abi $(call qstrip,$(BR2_GCC_TARGET_FLOAT_ABI))
+endif
+
+# We must specify a full path to ccache and a full path to the flutter-engine
+# provided clang in order to use ccache, or else flutter-engine will error out
+# attempting to find ccache in the target-toolchain provided path.
+ifeq ($(BR2_CCACHE),y)
+define FLUTTER_ENGINE_COMPILER_PATH_FIXUP
+	$(SED) "s%cc =.*%cc = \"$(HOST_DIR)/bin/ccache $(FLUTTER_ENGINE_CLANG_PATH)/bin/clang\""%g \
+		$(@D)/build/toolchain/custom/BUILD.gn
+
+	$(SED) "s%cxx =.*%cxx = \"$(HOST_DIR)/bin/ccache $(FLUTTER_ENGINE_CLANG_PATH)/bin/clang++\""%g \
+		$(@D)/build/toolchain/custom/BUILD.gn
+endef
+FLUTTER_ENGINE_PRE_CONFIGURE_HOOKS += FLUTTER_ENGINE_COMPILER_PATH_FIXUP
+endif
+
+ifeq ($(BR2_ENABLE_LTO),y)
+FLUTTER_ENGINE_CONF_OPTS += --lto
+else
+FLUTTER_ENGINE_CONF_OPTS += --no-lto
+endif
+
+ifeq ($(BR2_OPTIMIZE_0),y)
+FLUTTER_ENGINE_CONF_OPTS += --unoptimized
+endif
+
+# There is no --disable-fontconfig option.
+ifeq ($(BR2_PACKAGE_FONTCONFIG),y)
+FLUTTER_ENGINE_DEPENDENCIES += fontconfig
+FLUTTER_ENGINE_CONF_OPTS += --enable-fontconfig
+endif
+
+ifeq ($(BR2_PACKAGE_HAS_LIBGL),y)
+FLUTTER_ENGINE_DEPENDENCIES += libgl
+endif
+
+ifeq ($(BR2_PACKAGE_HAS_LIBGLES),y)
+FLUTTER_ENGINE_DEPENDENCIES += libgles
+endif
+
+ifeq ($(BR2_PACKAGE_LIBGLFW),y)
+FLUTTER_ENGINE_DEPENDENCIES += libglfw
+FLUTTER_ENGINE_CONF_OPTS += --build-glfw-shell
+else
+FLUTTER_ENGINE_CONF_OPTS += --no-build-glfw-shell
+endif
+
+ifeq ($(BR2_PACKAGE_LIBGTK3),y)
+FLUTTER_ENGINE_DEPENDENCIES += libgtk3
+FLUTTER_ENGINE_INSTALL_FILES += libflutter_linux_gtk.so
+else
+FLUTTER_ENGINE_CONF_OPTS += --disable-desktop-embeddings
+endif
+
+# There is no --disable-vulkan option
+ifeq ($(BR2_PACKAGE_MESA3D_VULKAN_DRIVER),y)
+FLUTTER_ENGINE_CONF_OPTS += --enable-vulkan
+endif
+
+ifeq ($(BR2_PACKAGE_XORG7)$(BR2_PACKAGE_LIBXCB),yy)
+FLUTTER_ENGINE_DEPENDENCIES += libxcb
+else
+define FLUTTER_ENGINE_VULKAN_X11_SUPPORT_FIXUP
+	$(SED) "s%vulkan_use_x11.*%vulkan_use_x11 = false%g" -i \
+		$(@D)/build_overrides/vulkan_headers.gni
+endef
+FLUTTER_ENGINE_PRE_CONFIGURE_HOOKS += FLUTTER_ENGINE_VULKAN_X11_SUPPORT_FIXUP
+endif
+
+ifeq ($(BR2_PACKAGE_WAYLAND),y)
+FLUTTER_ENGINE_DEPENDENCIES += wayland
+else
+define FLUTTER_ENGINE_VULKAN_WAYLAND_SUPPORT_FIXUP
+	$(SED) "s%vulkan_use_wayland.*%vulkan_use_wayland = false%g" \
+		$(@D)/build_overrides/vulkan_headers.gni
+endef
+FLUTTER_ENGINE_PRE_CONFIGURE_HOOKS += FLUTTER_ENGINE_VULKAN_WAYLAND_SUPPORT_FIXUP
+endif
+
+# Generate a tarball if one does not already exist.
+define FLUTTER_ENGINE_GENERATE_TARBALL
+	PATH=$(BR_PATH):$(HOST_DIR)/share/depot_tools \
+	PYTHONPATH=$(HOST_DIR)/lib/python$(PYTHON3_VERSION_MAJOR) \
+	$(FLUTTER_ENGINE_PKGDIR)/gen-tarball \
+		--dot-gclient $(FLUTTER_ENGINE_PKGDIR)/dot-gclient \
+		--jobs $(PARALLEL_JOBS) \
+		--scratch-dir $(@D)/dl-tmp \
+		--tarball-dl-path $(FLUTTER_ENGINE_TARBALL_PATH) \
+		--version $(FLUTTER_ENGINE_VERSION)
+endef
+FLUTTER_ENGINE_POST_DOWNLOAD_HOOKS += FLUTTER_ENGINE_GENERATE_TARBALL
+
+define FLUTTER_ENGINE_EXTRACT_CMDS
+	gzip -d -c $(FLUTTER_ENGINE_TARBALL_PATH) | tar --strip-components 1 -C $(@D) -xf -
+endef
+
+define FLUTTER_ENGINE_CONFIGURE_CMDS
+	cd $(@D) && \
+		rm -rf $(FLUTTER_ENGINE_BUILD_DIR) && \
+		PATH=$(BR_PATH):$(HOST_DIR)/share/depot_tools \
+		./flutter/tools/gn \
+			$(FLUTTER_ENGINE_CONF_OPTS)
+endef
+
+define FLUTTER_ENGINE_BUILD_CMDS
+	cd $(@D) && \
+		PATH=$(BR_PATH) \
+		$(HOST_DIR)/bin/ninja \
+			-j $(PARALLEL_JOBS) \
+			-C $(FLUTTER_ENGINE_BUILD_DIR)
+endef
+
+# Flutter-engine builds an sdk used to compile flutter applications into usable
+# .so files for the target architecture. Compiling a host version of
+# flutter-engine would result in the sdk binaries producing host-architecture
+# flutter-applications. As such, copy the sdk files to the host directory here.
+FLUTTER_ENGINE_SDK = $(HOST_DIR)/share/flutter/$(FLUTTER_ENGINE_VERSION)/$(FLUTTER_ENGINE_RUNTIME_MODE)/sdk
+FLUTTER_ENGINE_GEN_SNAPSHOT = $(HOST_FLUTTER_SDK_BIN_ENV) $(FLUTTER_ENGINE_SDK)/gen_snapshot
+define FLUTTER_ENGINE_INSTALL_SDK
+	mkdir -p $(FLUTTER_ENGINE_SDK)
+	$(INSTALL) -D -m 0755 $(FLUTTER_ENGINE_BUILD_DIR)/clang_x64/exe.unstripped/* \
+		$(FLUTTER_ENGINE_SDK)/
+endef
+FLUTTER_ENGINE_POST_INSTALL_STAGING_HOOKS += FLUTTER_ENGINE_INSTALL_SDK
+
+define FLUTTER_ENGINE_INSTALL_STAGING_CMDS
+	$(foreach i,$(FLUTTER_ENGINE_INSTALL_FILES),
+		$(INSTALL) -D -m 0755 $(FLUTTER_ENGINE_BUILD_DIR)/so.unstripped/$(i) \
+			$(STAGING_DIR)/usr/lib/$(i); \
+	)
+	$(INSTALL) -D -m 0755 $(FLUTTER_ENGINE_BUILD_DIR)/flutter_embedder.h \
+		$(STAGING_DIR)/usr/include/flutter_embedder.h
+
+	$(INSTALL) -D -m 0755 $(FLUTTER_ENGINE_BUILD_DIR)/icudtl.dat \
+		$(STAGING_DIR)/usr/share/flutter/$(FLUTTER_ENGINE_VERSION)/$(FLUTTER_ENGINE_RUNTIME_MODE)/data/icudtl.dat
+endef
+
+define FLUTTER_ENGINE_INSTALL_TARGET_CMDS
+	$(foreach i,$(FLUTTER_ENGINE_INSTALL_FILES),
+		$(INSTALL) -D -m 0755 $(FLUTTER_ENGINE_BUILD_DIR)/so.unstripped/$(i) \
+			$(TARGET_DIR)/usr/lib/$(i); \
+	)
+	$(INSTALL) -D -m 0755 $(FLUTTER_ENGINE_BUILD_DIR)/icudtl.dat \
+		$(TARGET_DIR)/usr/share/flutter/$(FLUTTER_ENGINE_VERSION)/$(FLUTTER_ENGINE_RUNTIME_MODE)/data/icudtl.dat
+endef
+
+$(eval $(generic-package))
diff --git a/package/flutter-engine/gen-tarball b/package/flutter-engine/gen-tarball
new file mode 100755
index 0000000000..e040beac75
--- /dev/null
+++ b/package/flutter-engine/gen-tarball
@@ -0,0 +1,111 @@ 
+#!/usr/bin/env bash
+# Call gclient and generate a flutter-engine source tarball if one does not
+# already exist.
+set -eu
+
+DL_DIR=
+DOT_GCLIENT=
+JOBS=
+SCRATCH_DIR=
+TARBALL_DL_PATH=
+VERSION=
+TARBALL_NAME=
+
+# Print status messages in the same style Buildroot prints.
+message() {
+  term_bold="$(tput smso 2>/dev/null)"
+  term_reset="$(tput rmso 2>/dev/null)"
+  echo "${term_bold}>>> flutter-engine ${VERSION} ${1}${term_reset}"
+}
+
+parse_opts() {
+  local o O opts
+
+  o='d:j:s:t:v:'
+  O='dot-gclient:,jobs:,scratch-dir:,tarball-dl-path:,version:'
+  opts="$(getopt -o "${o}" -l "${O}" -- "${@}")"
+  eval set -- "${opts}"
+
+  while [ ${#} -gt 0 ]; do
+    case "${1}" in
+    (-d|--dot-gclient)
+      DOT_GCLIENT="${2}"
+      shift 2
+      ;;
+    (-j|--jobs)
+      JOBS="${2}"
+      shift 2
+      ;;
+    (-s|--scratch-dir)
+      SCRATCH_DIR="${2}"
+      shift 2
+      ;;
+    (-t|--tarball-dl-path)
+      DL_DIR=$(dirname "${2}")
+      TARBALL_DL_PATH="${2}"
+      shift 2
+      ;;
+    (-v|--version)
+      VERSION="${2}"
+      TARBALL_NAME=flutter-"${VERSION}".tar.gz
+      shift 2
+      ;;
+    (--)
+      shift
+      break
+      ;;
+    esac
+  done
+}
+
+copy_dot_gclient() {
+  rm -rf "${SCRATCH_DIR}"
+  mkdir -p "${SCRATCH_DIR}"
+  install -D -m 0755 "${DOT_GCLIENT}" "${SCRATCH_DIR}"/.gclient
+  sed "s%!FLUTTER_VERSION!%${VERSION}%g" -i "${SCRATCH_DIR}"/.gclient
+  cd "${SCRATCH_DIR}"
+}
+
+run_gclient() {
+  local gclient="${HOST_DIR}"/share/depot_tools/gclient.py
+  if [[ ! -e "${gclient}" ]]; then
+    message "${gclient} does not exist. Is host-depot-tools built and installed?"
+    exit 1
+  fi
+  message "Downloading"
+  "${gclient}" \
+    sync \
+    --delete_unversioned_trees \
+    --no-history \
+    --reset \
+    --shallow \
+    -j"${JOBS}"
+}
+
+gen_tarball() {
+  message "Generating tarball"
+  mkdir -p "${DL_DIR}"
+  # We would use the mk_tar_gz helper method from the support/download/helpers
+  # script here. However, due to unknown reasons other than what I can
+  # articulate as "Google," this is not possible. Even though creating a
+  # tarball using the mk_tar_gz command results in a tarball that extracts and
+  # builds flutter-engine without warnings or errors, the gen_snapshot host
+  # utility, which turns dart applications into usable .so files for the
+  # flutter engine, results in the error:
+  # "Can't load kernel binary: Invalid SDK hash." As we are not interested in
+  # creating a reproducible tarball, we need to use tar -C instead.
+  tar -C "${SCRATCH_DIR}"/src -czf "${TARBALL_NAME}" .
+  mv "${TARBALL_NAME}" "${TARBALL_DL_PATH}"
+  rm -rf "${SCRATCH_DIR}"
+}
+
+main() {
+  parse_opts "${@}"
+  if [[ ! -e "${TARBALL_DL_PATH}" ]]; then
+    copy_dot_gclient
+    run_gclient
+    gen_tarball
+  fi
+}
+
+main "${@}"