flutter · rmacnak-google · Aug 20, 2025 · Aug 12, 2025
diff --git a/engine/src/build/config/android/config.gni b/engine/src/build/config/android/config.gni
@@ -67,7 +67,9 @@ if (is_android) {
 
   zipalign_path = "$android_sdk_build_tools/zipalign"
 
-  if (current_cpu != "x64" && current_cpu != "arm64") {
+  if (current_cpu == "riscv64") {
+    android_api_level = 35
+  } else if (current_cpu != "x64" && current_cpu != "arm64") {
     android_api_level = 21
   }
 
@@ -101,6 +103,9 @@ if (is_android) {
   } else if (current_cpu == "arm64") {
     android_app_abi = "arm64-v8a"
     _android_lib_dir = "aarch64-linux-android"
+  } else if (current_cpu == "riscv64") {
+    android_app_abi = "riscv64"
+    _android_lib_dir = "riscv64-linux-android"
   } else {
     assert(false, "Unknown Android ABI: " + current_cpu)
   }

diff --git a/engine/src/build/config/compiler/BUILD.gn b/engine/src/build/config/compiler/BUILD.gn
@@ -33,7 +33,8 @@ declare_args() {
 
   # By default, API calls to deprecated methods are errors. While prototyping,
   # this flag may be set to allow such calls.
-  allow_deprecated_api_calls = false
+  # riscv64: https://github.com/flutter/flutter/issues/173656
+  allow_deprecated_api_calls = target_cpu == "riscv64"
 
   # This flag is deprecated and will be removed. The value will be ignored.
   use_fstack_protector = false
@@ -464,6 +465,9 @@ config("compiler") {
     } else if (current_cpu == "x64") {
       cflags += [ "--target=x86_64-linux-androideabi${android_api_level}" ]
       ldflags += [ "--target=x86_64-linux-androideabi${android_api_level}" ]
+    } else if (current_cpu == "riscv64") {
+      cflags += [ "--target=riscv64-linux-androideabi${android_api_level}" ]
+      ldflags += [ "--target=riscv64-linux-androideabi${android_api_level}" ]
     }
   }
 

diff --git a/engine/src/build/toolchain/android/BUILD.gn b/engine/src/build/toolchain/android/BUILD.gn
@@ -152,3 +152,7 @@ android_toolchains_helper("arm64_apilevel26") {
     android_api_level = 26
   }
 }
+
+android_toolchains_helper("riscv64") {
+  toolchain_cpu = "riscv64"
+}
diff --git a/engine/src/flutter/assets/native_assets.cc b/engine/src/flutter/assets/native_assets.cc
@@ -17,6 +17,10 @@ namespace flutter {
 #define kTargetArchitectureName "ia32"
 #elif defined(FML_ARCH_CPU_X86_64)
 #define kTargetArchitectureName "x64"
+#elif defined(FML_ARCH_CPU_RISCV32)
+#define kTargetArchitectureName "riscv32"
+#elif defined(FML_ARCH_CPU_RISCV64)
+#define kTargetArchitectureName "riscv64"
 #else
 #error Target architecture detection failed.
 #endif

diff --git a/engine/src/flutter/ci/builders/linux_android_aot_engine.json b/engine/src/flutter/ci/builders/linux_android_aot_engine.json
@@ -299,6 +299,98 @@
                     "flutter/shell/platform/android:analyze_snapshot"
                 ]
             }
+        },
+        {
+            "archives": [
+                {
+                    "name": "ci/android_profile_riscv64",
+                    "type": "gcs",
+                    "base_path": "out/ci/android_profile_riscv64/zip_archives/",
+                    "include_paths": [
+                        "out/ci/android_profile_riscv64/zip_archives/android-riscv64-profile/artifacts.zip",
+                        "out/ci/android_profile_riscv64/zip_archives/android-riscv64-profile/linux-x64.zip",
+                        "out/ci/android_profile_riscv64/zip_archives/android-riscv64-profile/symbols.zip",
+                        "out/ci/android_profile_riscv64/zip_archives/android-riscv64-profile/analyze-snapshot-linux-x64.zip",
+                        "out/ci/android_profile_riscv64/zip_archives/download.flutter.io"
+                    ],
+                    "realm": "production"
+                }
+            ],
+            "drone_dimensions": [
+                "device_type=none",
+                "os=Linux"
+            ],
+            "gclient_variables": {
+                "use_rbe": true
+            },
+            "gn": [
+                "--target-dir",
+                "ci/android_profile_riscv64",
+                "--runtime-mode",
+                "profile",
+                "--android",
+                "--android-cpu",
+                "riscv64",
+                "--rbe",
+                "--no-goma"
+            ],
+            "name": "ci/android_profile_riscv64",
+            "description": "Produces profile mode artifacts to target riscv64 Android from a Linux host.",
+            "ninja": {
+                "config": "ci/android_profile_riscv64",
+                "targets": [
+                    "default",
+                    "clang_x64/gen_snapshot",
+                    "flutter/shell/platform/android:abi_jars",
+                    "flutter/shell/platform/android:analyze_snapshot"
+                ]
+            }
+        },
+        {
+            "archives": [
+                {
+                    "name": "ci/android_release_riscv64",
+                    "type": "gcs",
+                    "base_path": "out/ci/android_release_riscv64/zip_archives/",
+                    "include_paths": [
+                        "out/ci/android_release_riscv64/zip_archives/android-riscv64-release/artifacts.zip",
+                        "out/ci/android_release_riscv64/zip_archives/android-riscv64-release/linux-x64.zip",
+                        "out/ci/android_release_riscv64/zip_archives/android-riscv64-release/symbols.zip",
+                        "out/ci/android_release_riscv64/zip_archives/android-riscv64-release/analyze-snapshot-linux-x64.zip",
+                        "out/ci/android_release_riscv64/zip_archives/download.flutter.io"
+                    ],
+                    "realm": "production"
+                }
+            ],
+            "drone_dimensions": [
+                "device_type=none",
+                "os=Linux"
+            ],
+            "gclient_variables": {
+                "use_rbe": true
+            },
+            "gn": [
+                "--target-dir",
+                "ci/android_release_riscv64",
+                "--runtime-mode",
+                "release",
+                "--android",
+                "--android-cpu",
+                "riscv64",
+                "--rbe",
+                "--no-goma"
+            ],
+            "name": "ci/android_release_riscv64",
+            "description": "Produces release mode artifacts to target riscv64 Android from a Linux host.",
+            "ninja": {
+                "config": "ci/android_release_riscv64",
+                "targets": [
+                    "default",
+                    "clang_x64/gen_snapshot",
+                    "flutter/shell/platform/android:abi_jars",
+                    "flutter/shell/platform/android:analyze_snapshot"
+                ]
+            }
         }
     ],
     "generators": {

diff --git a/engine/src/flutter/ci/builders/linux_android_debug_engine.json b/engine/src/flutter/ci/builders/linux_android_debug_engine.json
@@ -192,6 +192,50 @@
                     "flutter/impeller/toolkit/interop:sdk"
                 ]
             }
+        },
+        {
+            "archives": [
+                {
+                    "name": "ci/android_debug_riscv64",
+                    "type": "gcs",
+                    "base_path": "out/ci/android_debug_riscv64/zip_archives/",
+                    "include_paths": [
+                        "out/ci/android_debug_riscv64/zip_archives/android-riscv64/artifacts.zip",
+                        "out/ci/android_debug_riscv64/zip_archives/android-riscv64/android-riscv64-embedder.zip",
+                        "out/ci/android_debug_riscv64/zip_archives/android-riscv64/impeller_sdk.zip",
+                        "out/ci/android_debug_riscv64/zip_archives/android-riscv64/symbols.zip",
+                        "out/ci/android_debug_riscv64/zip_archives/download.flutter.io"
+                    ],
+                    "realm": "production"
+                }
+            ],
+            "drone_dimensions": [
+                "device_type=none",
+                "os=Linux"
+            ],
+            "gclient_variables": {
+                "use_rbe": true
+            },
+            "gn": [
+                "--target-dir",
+                "ci/android_debug_riscv64",
+                "--android",
+                "--android-cpu=riscv64",
+                "--no-lto",
+                "--rbe",
+                "--no-goma"
+            ],
+            "name": "ci/android_debug_riscv64",
+            "description": "Produces debug mode artifacts to target riscv64 Android from a Linux host.",
+            "ninja": {
+                "config": "ci/android_debug_riscv64",
+                "targets": [
+                    "flutter",
+                    "flutter/shell/platform/android:abi_jars",
+                    "flutter/shell/platform/embedder:embedder-archive",
+                    "flutter/impeller/toolkit/interop:sdk"
+                ]
+            }
         }
     ],
     "generators": {

diff --git a/engine/src/flutter/ci/builders/local_engine.json b/engine/src/flutter/ci/builders/local_engine.json
@@ -261,6 +261,32 @@
         "targets": []
       }
     },
+    {
+      "cas_archive": false,
+      "drone_dimensions": [
+        "os=Linux",
+        "device_type=none"
+      ],
+      "gclient_variables": {
+        "use_rbe": true
+      },
+      "gn": [
+        "--runtime-mode",
+        "debug",
+        "--android",
+        "--android-cpu=riscv64",
+        "--no-stripped",
+        "--no-lto",
+        "--rbe",
+        "--no-goma"
+      ],
+      "name": "linux/android_debug_riscv64",
+      "description": "Builds a debug mode engine that targets riscv64 Android from a Linux host.",
+      "ninja": {
+        "config": "android_debug_riscv64",
+        "targets": []
+      }
+    },
     {
       "cas_archive": false,
       "drone_dimensions": [

diff --git a/engine/src/flutter/fml/build_config.h b/engine/src/flutter/fml/build_config.h
@@ -93,6 +93,16 @@
 #define FML_ARCH_CPU_ARM64 1
 #define FML_ARCH_CPU_64_BITS 1
 #define FML_ARCH_CPU_LITTLE_ENDIAN 1
+#elif defined(__riscv) && __SIZEOF_POINTER__ == 4
+#define FML_ARCH_CPU_RISCV_FAMILY 1
+#define FML_ARCH_CPU_RISCV32 1
+#define FML_ARCH_CPU_32_BITS 1
+#define FML_ARCH_CPU_LITTLE_ENDIAN 1
+#elif defined(__riscv) && __SIZEOF_POINTER__ == 8
+#define FML_ARCH_CPU_RISCV_FAMILY 1
+#define FML_ARCH_CPU_RISCV64 1
+#define FML_ARCH_CPU_64_BITS 1
+#define FML_ARCH_CPU_LITTLE_ENDIAN 1
 #elif defined(__pnacl__)
 #define FML_ARCH_CPU_32_BITS 1
 #define FML_ARCH_CPU_LITTLE_ENDIAN 1

diff --git a/engine/src/flutter/lib/snapshot/BUILD.gn b/engine/src/flutter/lib/snapshot/BUILD.gn
@@ -41,13 +41,14 @@ group("generate_snapshot_bins") {
     # For iOS, Android target builds: all AOT target CPUs are arm/arm64.
     public_deps += [ ":create_arm_gen_snapshot" ]
   } else if (target_cpu == "arm" || target_cpu == "arm64" ||
-             target_cpu == "x64") {
+             target_cpu == "x64" || target_cpu == "riscv64") {
     # For other host OSes, build gen_snapshot directly.
     public_deps = [ "$dart_src/runtime/bin:gen_snapshot($host_toolchain)" ]
   }
 
   # Build analyze_snapshot for 64-bit target CPUs.
-  if (host_os == "linux" && (target_cpu == "x64" || target_cpu == "arm64")) {
+  if (host_os == "linux" && (target_cpu == "x64" || target_cpu == "arm64" ||
+                             target_cpu == "riscv64")) {
     public_deps += [ "$dart_src/runtime/bin:analyze_snapshot($host_toolchain)" ]
   }
 }

@@ -796,7 +796,8 @@ if (target_cpu != "x86") {
   }
 }
 
-if (host_os == "linux" && (target_cpu == "x64" || target_cpu == "arm64")) {
+if (host_os == "linux" &&
+    (target_cpu == "x64" || target_cpu == "arm64" || target_cpu == "riscv64")) {
   zip_bundle("analyze_snapshot") {
     deps = [ "$dart_src/runtime/bin:analyze_snapshot($host_toolchain)" ]
 

diff --git a/engine/src/flutter/third_party/tonic/common/build_config.h b/engine/src/flutter/third_party/tonic/common/build_config.h
@@ -88,6 +88,16 @@
 #define ARCH_CPU_ARM64 1
 #define ARCH_CPU_64_BITS 1
 #define ARCH_CPU_LITTLE_ENDIAN 1
+#elif defined(__riscv) && __SIZEOF_POINTER__ == 4
+#define ARCH_CPU_RISCV_FAMILY 1
+#define ARCH_CPU_RISCV32 1
+#define ARCH_CPU_32_BITS 1
+#define ARCH_CPU_LITTLE_ENDIAN 1
+#elif defined(__riscv) && __SIZEOF_POINTER__ == 8
+#define ARCH_CPU_RISCV_FAMILY 1
+#define ARCH_CPU_RISCV64 1
+#define ARCH_CPU_64_BITS 1
+#define ARCH_CPU_LITTLE_ENDIAN 1
 #elif defined(__pnacl__)
 #define ARCH_CPU_32_BITS 1
 #define ARCH_CPU_LITTLE_ENDIAN 1

diff --git a/engine/src/flutter/tools/engine_tool/lib/src/commands/run_command.dart b/engine/src/flutter/tools/engine_tool/lib/src/commands/run_command.dart
@@ -234,6 +234,7 @@ final class RunTarget {
       TargetPlatform.androidX86 => 'android_${mode}_x86',
       TargetPlatform.androidX64 => 'android_${mode}_x64',
       TargetPlatform.androidArm64 => 'android_${mode}_arm64',
+      TargetPlatform.androidRiscv64 => 'android_${mode}_riscv64',
 
       // DESKTOP (MacOS, Linux, Windows)
       // We do not support cross-builds, so implicitly assume the host platform.
@@ -291,6 +292,7 @@ final class RunTarget {
       TargetPlatform.androidUnspecified ||
       TargetPlatform.androidX86 ||
       TargetPlatform.androidX64 ||
+      TargetPlatform.androidRiscv64 ||
       TargetPlatform.androidArm64 => [
         Label.parseGn('//flutter/shell/platform/android:android_jar'),
       ],

diff --git a/engine/src/flutter/tools/engine_tool/lib/src/flutter_tool_interop/target_platform.dart b/engine/src/flutter/tools/engine_tool/lib/src/flutter_tool_interop/target_platform.dart
@@ -23,6 +23,9 @@ final class TargetPlatform {
   /// Android ARM64.
   static const androidArm64 = TargetPlatform._('android-arm64');
 
+  /// Android RISCV64.
+  static const androidRiscv64 = TargetPlatform._('android-riscv64');
+
   /// Android x64.
   static const androidX64 = TargetPlatform._('android-x64');
 
@@ -87,6 +90,7 @@ final class TargetPlatform {
     androidUnspecified,
     androidArm,
     androidArm64,
+    androidRiscv64,
     androidX64,
     androidX86,
     linuxArm64,

diff --git a/engine/src/flutter/tools/engine_tool/test/run_target_test.dart b/engine/src/flutter/tools/engine_tool/test/run_target_test.dart
@@ -63,6 +63,7 @@ void main() {
       TargetPlatform.androidX86: 'android_debug_x86',
       TargetPlatform.androidX64: 'android_debug_x64',
       TargetPlatform.androidArm64: 'android_debug_arm64',
+      TargetPlatform.androidRiscv64: 'android_debug_riscv64',
       TargetPlatform.darwinUnspecified: 'host_debug',
       TargetPlatform.darwinX64: 'host_debug',
       TargetPlatform.darwinArm64: 'host_debug_arm64',
@@ -100,6 +101,9 @@ void main() {
       TargetPlatform.androidX86: [Label.parseGn('//flutter/shell/platform/android:android_jar')],
       TargetPlatform.androidX64: [Label.parseGn('//flutter/shell/platform/android:android_jar')],
       TargetPlatform.androidArm64: [Label.parseGn('//flutter/shell/platform/android:android_jar')],
+      TargetPlatform.androidRiscv64: [
+        Label.parseGn('//flutter/shell/platform/android:android_jar'),
+      ],
       TargetPlatform.iOSUnspecified: [
         Label.parseGn('//flutter/shell/platform/darwin/ios:flutter_framework'),
       ],

diff --git a/engine/src/flutter/tools/gn b/engine/src/flutter/tools/gn
@@ -947,7 +947,7 @@ def parse_args(args):
   )
   parser.add_argument('--android', dest='target_os', action='store_const', const='android')
   parser.add_argument(
-      '--android-cpu', type=str, choices=['arm', 'x64', 'x86', 'arm64'], default='arm'
+      '--android-cpu', type=str, choices=['arm', 'x64', 'x86', 'arm64', 'riscv64'], default='arm'
   )
   parser.add_argument('--ios', dest='target_os', action='store_const', const='ios')
   parser.add_argument('--mac', dest='target_os', action='store_const', const='mac')