Host Flutter tool patch alongside engine

src/static/index.html

@@ -49,6 +49,6 @@
 
     <h2>Hosted artifacts:</h2>
     <h3>Flutter 3.38.9 - <a href="flutter_infra_release/flutter/587c18f873b8ab57330422bce09047420d9c7f42/">587c18f873b8ab57330422bce09047420d9c7f42</a></h3>
-    <p style="margin-left: 20px;"><a href="https://code.launchpad.net/~vhaudiquet/+git/flutter/+build/207763">Launchpad build</a></p>
+    <p style="margin-left: 20px;"><a href="https://code.launchpad.net/~vhaudiquet/+git/flutter/+build/207763">Launchpad build</a><a href="tool/3.38.9.patch">Tool patch</a></p>
 </body>
 </html>

src/static/tool/3.38.9.patch

@@ -0,0 +1,668 @@
+commit 03f313d12ed3d2c381cb48617442d7a4c5f9d643
+Author: Valentin Haudiquet <valentin.haudiquet@canonical.com>
+Date:   Tue Dec 2 19:52:25 2025 +0100
+
+    [ Tool ] Support riscv64 architecture
+    
+    This adds support for buildind desktop linux applications for riscv64 on the flutter tool, as well as basic riscv64 support for the tool.
+
+diff --git a/bin/internal/update_dart_sdk.sh b/bin/internal/update_dart_sdk.sh
+index 9ab6151021a..878c9e59ea9 100755
+--- a/bin/internal/update_dart_sdk.sh
++++ b/bin/internal/update_dart_sdk.sh
+@@ -89,6 +89,9 @@ if [ ! -f "$ENGINE_STAMP" ] || [ "$ENGINE_VERSION" != `cat "$ENGINE_STAMP"` ]; t
+       x86_64)
+         ARCH="x64"
+         ;;
++      riscv64)
++        ARCH="riscv64"
++        ;;
+       *)
+         ARCH="arm64"
+         ;;
+diff --git a/packages/flutter_tools/lib/src/android/android_device.dart b/packages/flutter_tools/lib/src/android/android_device.dart
+index 2813a7ea069..fae4fb66575 100644
+--- a/packages/flutter_tools/lib/src/android/android_device.dart
++++ b/packages/flutter_tools/lib/src/android/android_device.dart
+@@ -228,6 +228,7 @@ class AndroidDevice extends Device {
+       case TargetPlatform.fuchsia_x64:
+       case TargetPlatform.ios:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.tester:
+       case TargetPlatform.web_javascript:
+@@ -551,6 +552,7 @@ class AndroidDevice extends Device {
+       case TargetPlatform.fuchsia_x64:
+       case TargetPlatform.ios:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.tester:
+       case TargetPlatform.web_javascript:
+diff --git a/packages/flutter_tools/lib/src/artifacts.dart b/packages/flutter_tools/lib/src/artifacts.dart
+index 545b594ec45..3cb6fd2f21a 100644
+--- a/packages/flutter_tools/lib/src/artifacts.dart
++++ b/packages/flutter_tools/lib/src/artifacts.dart
+@@ -30,6 +30,7 @@ enum Artifact {
+   /// The tool which compiles a dart kernel file into native code.
+   genSnapshot,
+   genSnapshotArm64,
++  genSnapshotRiscv64,
+   genSnapshotX64,
+ 
+   /// The flutter tester binary.
+@@ -155,6 +156,7 @@ TargetPlatform? _mapTargetPlatform(TargetPlatform? targetPlatform) {
+     case TargetPlatform.darwin:
+     case TargetPlatform.linux_x64:
+     case TargetPlatform.linux_arm64:
++    case TargetPlatform.linux_riscv64:
+     case TargetPlatform.windows_x64:
+     case TargetPlatform.windows_arm64:
+     case TargetPlatform.fuchsia_arm64:
+@@ -177,6 +179,8 @@ String? _artifactToFileName(Artifact artifact, Platform hostPlatform, [BuildMode
+       return 'gen_snapshot';
+     case Artifact.genSnapshotArm64:
+       return 'gen_snapshot_arm64';
++    case Artifact.genSnapshotRiscv64:
++      return 'gen_snapshot_riscv64';
+     case Artifact.genSnapshotX64:
+       return 'gen_snapshot_x64';
+     case Artifact.flutterTester:
+@@ -519,6 +523,7 @@ class CachedArtifacts implements Artifacts {
+       case TargetPlatform.darwin:
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.windows_x64:
+       case TargetPlatform.windows_arm64:
+         return _getDesktopArtifactPath(artifact, platform!, mode);
+@@ -550,6 +555,7 @@ class CachedArtifacts implements Artifacts {
+     switch (artifact) {
+       case Artifact.genSnapshot:
+       case Artifact.genSnapshotArm64:
++      case Artifact.genSnapshotRiscv64:
+       case Artifact.genSnapshotX64:
+         return _fileSystem.path.join(engineDir, _artifactToFileName(artifact, _platform));
+       case Artifact.engineDartSdkPath:
+@@ -590,6 +596,7 @@ class CachedArtifacts implements Artifacts {
+     switch (artifact) {
+       case Artifact.genSnapshot:
+       case Artifact.genSnapshotArm64:
++      case Artifact.genSnapshotRiscv64:
+       case Artifact.genSnapshotX64:
+         assert(mode != BuildMode.debug, 'Artifact $artifact only available in non-debug mode.');
+ 
+@@ -647,6 +654,7 @@ class CachedArtifacts implements Artifacts {
+     switch (artifact) {
+       case Artifact.genSnapshot:
+       case Artifact.genSnapshotArm64:
++      case Artifact.genSnapshotRiscv64:
+       case Artifact.genSnapshotX64:
+       case Artifact.flutterXcframework:
+         final String artifactFileName = _artifactToFileName(artifact, _platform)!;
+@@ -699,6 +707,7 @@ class CachedArtifacts implements Artifacts {
+         final genSnapshot = mode.isRelease ? 'gen_snapshot_product' : 'gen_snapshot';
+         return _fileSystem.path.join(root, runtime, 'dart_binaries', genSnapshot);
+       case Artifact.genSnapshotArm64:
++      case Artifact.genSnapshotRiscv64:
+       case Artifact.genSnapshotX64:
+         throw ArgumentError('$artifact is not available on this platform');
+       case Artifact.flutterPatchedSdkPath:
+@@ -757,6 +766,7 @@ class CachedArtifacts implements Artifacts {
+     switch (artifact) {
+       case Artifact.genSnapshot:
+       case Artifact.genSnapshotArm64:
++      case Artifact.genSnapshotRiscv64:
+       case Artifact.genSnapshotX64:
+         // For script snapshots any gen_snapshot binary will do. Returning gen_snapshot for
+         // android_arm in profile mode because it is available on all supported host platforms.
+@@ -878,6 +888,7 @@ class CachedArtifacts implements Artifacts {
+     switch (platform) {
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.darwin:
+       case TargetPlatform.windows_x64:
+       case TargetPlatform.windows_arm64:
+@@ -919,9 +930,11 @@ TargetPlatform _currentHostPlatform(Platform platform, OperatingSystemUtils oper
+     return TargetPlatform.darwin;
+   }
+   if (platform.isLinux) {
+-    return operatingSystemUtils.hostPlatform == HostPlatform.linux_x64
+-        ? TargetPlatform.linux_x64
+-        : TargetPlatform.linux_arm64;
++    return switch (operatingSystemUtils.hostPlatform) {
++      HostPlatform.linux_x64 => TargetPlatform.linux_x64,
++      HostPlatform.linux_riscv64 => TargetPlatform.linux_riscv64,
++      _ => TargetPlatform.linux_arm64,
++    };
+   }
+   if (platform.isWindows) {
+     return operatingSystemUtils.hostPlatform == HostPlatform.windows_arm64
+@@ -1197,6 +1210,7 @@ class CachedLocalEngineArtifacts implements Artifacts {
+     switch (artifact) {
+       case Artifact.genSnapshot:
+       case Artifact.genSnapshotArm64:
++      case Artifact.genSnapshotRiscv64:
+       case Artifact.genSnapshotX64:
+         return _genSnapshotPath(artifact);
+       case Artifact.flutterTester:
+@@ -1338,6 +1352,8 @@ class CachedLocalEngineArtifacts implements Artifacts {
+     switch (hostPlatform) {
+       case TargetPlatform.darwin:
+         return 'macos-x64';
++      case TargetPlatform.linux_riscv64:
++        return 'linux-riscv64';
+       case TargetPlatform.linux_arm64:
+         return 'linux-arm64';
+       case TargetPlatform.linux_x64:
+@@ -1373,6 +1389,7 @@ class CachedLocalEngineArtifacts implements Artifacts {
+       'clang_x86',
+       'clang_i386',
+       'clang_arm64',
++      'clang_riscv64',
+     ];
+     final String genSnapshotName = _artifactToFileName(artifact, _platform)!;
+     for (final clangDir in clangDirs) {
+@@ -1445,6 +1462,7 @@ class CachedLocalWebSdkArtifacts implements Artifacts {
+           );
+         case Artifact.genSnapshot:
+         case Artifact.genSnapshotArm64:
++        case Artifact.genSnapshotRiscv64:
+         case Artifact.genSnapshotX64:
+         case Artifact.flutterTester:
+         case Artifact.flutterFramework:
+@@ -1570,6 +1588,8 @@ class CachedLocalWebSdkArtifacts implements Artifacts {
+         return 'macos-x64';
+       case TargetPlatform.linux_arm64:
+         return 'linux-arm64';
++      case TargetPlatform.linux_riscv64:
++        return 'linux-riscv64';
+       case TargetPlatform.linux_x64:
+         return 'linux-x64';
+       case TargetPlatform.windows_x64:
+diff --git a/packages/flutter_tools/lib/src/base/build.dart b/packages/flutter_tools/lib/src/base/build.dart
+index 4551708cbfe..9cd34be24c3 100644
+--- a/packages/flutter_tools/lib/src/base/build.dart
++++ b/packages/flutter_tools/lib/src/base/build.dart
+@@ -360,6 +360,7 @@ class AOTSnapshotter {
+       TargetPlatform.darwin,
+       TargetPlatform.linux_x64,
+       TargetPlatform.linux_arm64,
++      TargetPlatform.linux_riscv64,
+       TargetPlatform.windows_x64,
+       TargetPlatform.windows_arm64,
+     ].contains(platform);
+diff --git a/packages/flutter_tools/lib/src/base/os.dart b/packages/flutter_tools/lib/src/base/os.dart
+index 5b499fef54f..297bf10159c 100644
+--- a/packages/flutter_tools/lib/src/base/os.dart
++++ b/packages/flutter_tools/lib/src/base/os.dart
+@@ -279,6 +279,8 @@ class _PosixUtils extends OperatingSystemUtils {
+         );
+       } else if (hostPlatformCheck.stdout.trim().endsWith('x86_64')) {
+         _hostPlatform = HostPlatform.linux_x64;
++      } else if (hostPlatformCheck.stdout.trim().endsWith('riscv64')) {
++        _hostPlatform = HostPlatform.linux_riscv64;
+       } else {
+         // We default to ARM if it's not x86_64 and we did not get an error.
+         _hostPlatform = HostPlatform.linux_arm64;
+@@ -611,6 +613,7 @@ enum HostPlatform {
+   darwin_arm64,
+   linux_x64,
+   linux_arm64,
++  linux_riscv64,
+   windows_x64,
+   windows_arm64;
+ 
+@@ -619,6 +622,7 @@ enum HostPlatform {
+     HostPlatform.darwin_arm64 => 'arm64',
+     HostPlatform.linux_x64 => 'x64',
+     HostPlatform.linux_arm64 => 'arm64',
++    HostPlatform.linux_riscv64 => 'riscv64',
+     HostPlatform.windows_x64 => 'x64',
+     HostPlatform.windows_arm64 => 'arm64',
+   };
+@@ -630,6 +634,7 @@ String getNameForHostPlatform(HostPlatform platform) {
+     HostPlatform.darwin_arm64 => 'darwin-arm64',
+     HostPlatform.linux_x64 => 'linux-x64',
+     HostPlatform.linux_arm64 => 'linux-arm64',
++    HostPlatform.linux_riscv64 => 'linux-riscv64',
+     HostPlatform.windows_x64 => 'windows-x64',
+     HostPlatform.windows_arm64 => 'windows-arm64',
+   };
+diff --git a/packages/flutter_tools/lib/src/build_info.dart b/packages/flutter_tools/lib/src/build_info.dart
+index b59d4b3912b..f923af4c7d0 100644
+--- a/packages/flutter_tools/lib/src/build_info.dart
++++ b/packages/flutter_tools/lib/src/build_info.dart
+@@ -576,6 +576,7 @@ enum TargetPlatform {
+   darwin,
+   linux_x64,
+   linux_arm64,
++  linux_riscv64,
+   windows_x64,
+   windows_arm64,
+   fuchsia_arm64,
+@@ -604,6 +605,7 @@ enum TargetPlatform {
+       case TargetPlatform.darwin:
+       case TargetPlatform.ios:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.tester:
+       case TargetPlatform.web_javascript:
+@@ -618,6 +620,7 @@ enum TargetPlatform {
+     switch (this) {
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+         return 'linux';
+       case TargetPlatform.darwin:
+         return 'macos';
+@@ -652,6 +655,8 @@ enum TargetPlatform {
+       case TargetPlatform.linux_arm64:
+       case TargetPlatform.windows_arm64:
+         return 'arm64';
++      case TargetPlatform.linux_riscv64:
++        return 'riscv64';
+       case TargetPlatform.android:
+       case TargetPlatform.android_arm:
+       case TargetPlatform.android_arm64:
+@@ -786,6 +791,7 @@ String getNameForTargetPlatform(TargetPlatform platform, {DarwinArch? darwinArch
+     TargetPlatform.android_x64 => 'android-x64',
+     TargetPlatform.linux_x64 => 'linux-x64',
+     TargetPlatform.linux_arm64 => 'linux-arm64',
++    TargetPlatform.linux_riscv64 => 'linux-riscv64',
+     TargetPlatform.windows_x64 => 'windows-x64',
+     TargetPlatform.windows_arm64 => 'windows-arm64',
+     TargetPlatform.fuchsia_arm64 => 'fuchsia-arm64',
+@@ -811,6 +817,7 @@ TargetPlatform getTargetPlatformForName(String platform) {
+     'darwin' || 'darwin-x64' || 'darwin-arm64' => TargetPlatform.darwin,
+     'linux-x64' => TargetPlatform.linux_x64,
+     'linux-arm64' => TargetPlatform.linux_arm64,
++    'linux-riscv64' => TargetPlatform.linux_riscv64,
+     'windows-x64' => TargetPlatform.windows_x64,
+     'windows-arm64' => TargetPlatform.windows_arm64,
+     'web-javascript' => TargetPlatform.web_javascript,
+diff --git a/packages/flutter_tools/lib/src/build_system/targets/common.dart b/packages/flutter_tools/lib/src/build_system/targets/common.dart
+index 63eb1c736e8..f4695404411 100644
+--- a/packages/flutter_tools/lib/src/build_system/targets/common.dart
++++ b/packages/flutter_tools/lib/src/build_system/targets/common.dart
+@@ -228,6 +228,7 @@ class KernelSnapshot extends Target {
+       case TargetPlatform.fuchsia_x64:
+       case TargetPlatform.ios:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.tester:
+       case TargetPlatform.web_javascript:
+         forceLinkPlatform = false;
+@@ -243,7 +244,9 @@ class KernelSnapshot extends Target {
+       TargetPlatform.android_x64 => 'android',
+       TargetPlatform.darwin => 'macos',
+       TargetPlatform.ios => 'ios',
+-      TargetPlatform.linux_arm64 || TargetPlatform.linux_x64 => 'linux',
++      TargetPlatform.linux_arm64 ||
++      TargetPlatform.linux_riscv64 ||
++      TargetPlatform.linux_x64 => 'linux',
+       TargetPlatform.windows_arm64 || TargetPlatform.windows_x64 => 'windows',
+       TargetPlatform.tester || TargetPlatform.web_javascript => null,
+       TargetPlatform.unsupported => TargetPlatform.throwUnsupportedTarget(),
+diff --git a/packages/flutter_tools/lib/src/build_system/tools/shader_compiler.dart b/packages/flutter_tools/lib/src/build_system/tools/shader_compiler.dart
+index db28675db2d..c2f8820945c 100644
+--- a/packages/flutter_tools/lib/src/build_system/tools/shader_compiler.dart
++++ b/packages/flutter_tools/lib/src/build_system/tools/shader_compiler.dart
+@@ -112,6 +112,7 @@ class ShaderCompiler {
+       case TargetPlatform.android:
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.windows_x64:
+       case TargetPlatform.windows_arm64:
+         return <String>[
+diff --git a/packages/flutter_tools/lib/src/commands/assemble.dart b/packages/flutter_tools/lib/src/commands/assemble.dart
+index 2e7b11ad1e5..26b2dad909f 100644
+--- a/packages/flutter_tools/lib/src/commands/assemble.dart
++++ b/packages/flutter_tools/lib/src/commands/assemble.dart
+@@ -46,10 +46,13 @@ var _kDefaultTargets = <Target>[
+   // Linux targets
+   const DebugBundleLinuxAssets(TargetPlatform.linux_x64),
+   const DebugBundleLinuxAssets(TargetPlatform.linux_arm64),
++  const DebugBundleLinuxAssets(TargetPlatform.linux_riscv64),
+   const ProfileBundleLinuxAssets(TargetPlatform.linux_x64),
+   const ProfileBundleLinuxAssets(TargetPlatform.linux_arm64),
++  const ProfileBundleLinuxAssets(TargetPlatform.linux_riscv64),
+   const ReleaseBundleLinuxAssets(TargetPlatform.linux_x64),
+   const ReleaseBundleLinuxAssets(TargetPlatform.linux_arm64),
++  const ReleaseBundleLinuxAssets(TargetPlatform.linux_riscv64),
+   const ReleaseAndroidApplication(),
+   // This is a one-off rule for bundle and aot compat.
+   const CopyFlutterBundle(),
+diff --git a/packages/flutter_tools/lib/src/commands/build_bundle.dart b/packages/flutter_tools/lib/src/commands/build_bundle.dart
+index 927edb22877..06d0ef67a76 100644
+--- a/packages/flutter_tools/lib/src/commands/build_bundle.dart
++++ b/packages/flutter_tools/lib/src/commands/build_bundle.dart
+@@ -46,6 +46,7 @@ class BuildBundleCommand extends BuildSubCommand {
+           'darwin',
+           'linux-x64',
+           'linux-arm64',
++          'linux-riscv64',
+           'windows-x64',
+           'windows-arm64',
+         ],
+@@ -122,6 +123,7 @@ class BuildBundleCommand extends BuildSubCommand {
+         }
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+         if (!featureFlags.isLinuxEnabled) {
+           throwToolExit('Linux is not a supported target platform.');
+         }
+diff --git a/packages/flutter_tools/lib/src/commands/build_linux.dart b/packages/flutter_tools/lib/src/commands/build_linux.dart
+index 832be184a32..f948f87f0aa 100644
+--- a/packages/flutter_tools/lib/src/commands/build_linux.dart
++++ b/packages/flutter_tools/lib/src/commands/build_linux.dart
+@@ -23,13 +23,15 @@ class BuildLinuxCommand extends BuildSubCommand {
+   }) : _operatingSystemUtils = operatingSystemUtils,
+        super(verboseHelp: verboseHelp) {
+     addCommonDesktopBuildOptions(verboseHelp: verboseHelp);
+-    final defaultTargetPlatform = (_operatingSystemUtils.hostPlatform == HostPlatform.linux_arm64)
+-        ? 'linux-arm64'
+-        : 'linux-x64';
++    final String defaultTargetPlatform = switch (_operatingSystemUtils.hostPlatform) {
++      HostPlatform.linux_arm64 => 'linux-arm64',
++      HostPlatform.linux_riscv64 => 'linux-riscv64',
++      _ => 'linux-x64',
++    };
+     argParser.addOption(
+       'target-platform',
+       defaultsTo: defaultTargetPlatform,
+-      allowed: <String>['linux-arm64', 'linux-x64'],
++      allowed: <String>['linux-arm64', 'linux-x64', 'linux-riscv64'],
+       help: 'The target platform for which the app is compiled.',
+     );
+     argParser.addOption(
+@@ -79,9 +81,8 @@ class BuildLinuxCommand extends BuildSubCommand {
+     if (!globals.platform.isLinux) {
+       throwToolExit('"build linux" only supported on Linux hosts.');
+     }
+-    // Cross-building for x64 targets on arm64 hosts is not supported.
+-    if (_operatingSystemUtils.hostPlatform != HostPlatform.linux_x64 &&
+-        targetPlatform != TargetPlatform.linux_arm64) {
++    // Cross-building is only supported on x64 hosts
++    if (_operatingSystemUtils.hostPlatform != HostPlatform.linux_x64 && needCrossBuild) {
+       throwToolExit('"cross-building" only supported on Linux x64 hosts.');
+     }
+     // TODO(fujino): https://github.com/flutter/flutter/issues/74929
+@@ -91,6 +92,14 @@ class BuildLinuxCommand extends BuildSubCommand {
+         'Cross-build from Linux x64 host to Linux arm64 target is not currently supported.',
+       );
+     }
++    // Building for riscv64 (on a non-riscv64 host) is experimental
++    if (_operatingSystemUtils.hostPlatform != HostPlatform.linux_riscv64 &&
++        targetPlatform == TargetPlatform.linux_riscv64 &&
++        !featureFlags.isRiscv64SupportEnabled) {
++      throwToolExit(
++        'Building for Linux riscv64 is currently an experimental feature. To enable, run "flutter config --enable-riscv64"',
++      );
++    }
+     final Logger logger = globals.logger;
+     await buildLinux(
+       project.linux,
+diff --git a/packages/flutter_tools/lib/src/features.dart b/packages/flutter_tools/lib/src/features.dart
+index fdbfbfdca2e..ac2f5dbefb8 100644
+--- a/packages/flutter_tools/lib/src/features.dart
++++ b/packages/flutter_tools/lib/src/features.dart
+@@ -76,6 +76,9 @@ abstract class FeatureFlags {
+   /// Whether UIScene migration is enabled.
+   bool get isUISceneMigrationEnabled;
+ 
++  /// Wether riscv64 support is enabled.
++  bool get isRiscv64SupportEnabled;
++
+   /// Whether a particular feature is enabled for the current channel.
+   ///
+   /// Prefer using one of the specific getters above instead of this API.
+@@ -99,6 +102,7 @@ abstract class FeatureFlags {
+     windowingFeature,
+     lldbDebugging,
+     uiSceneMigration,
++    riscv64,
+   ];
+ 
+   /// All current Flutter feature flags that can be configured.
+@@ -268,6 +272,16 @@ const uiSceneMigration = Feature(
+   stable: FeatureChannelSetting(available: true),
+ );
+ 
++/// The [Feature] for building code targetting riscv64 architecture
++const riscv64 = Feature(
++  name: 'support for riscv64 architecture',
++  configSetting: 'enable-riscv64',
++  environmentOverride: 'FLUTTER_RISCV64',
++  master: FeatureChannelSetting(available: true, enabledByDefault: true),
++  beta: FeatureChannelSetting(available: true),
++  stable: FeatureChannelSetting(available: true),
++);
++
+ /// A [Feature] is a process for conditionally enabling tool features.
+ ///
+ /// All settings are optional, and if not provided will generally default to
+diff --git a/packages/flutter_tools/lib/src/flutter_application_package.dart b/packages/flutter_tools/lib/src/flutter_application_package.dart
+index 75eaeea481e..c61de499a28 100644
+--- a/packages/flutter_tools/lib/src/flutter_application_package.dart
++++ b/packages/flutter_tools/lib/src/flutter_application_package.dart
+@@ -91,6 +91,7 @@ class FlutterApplicationPackageFactory extends ApplicationPackageFactory {
+         return WebApplicationPackage(FlutterProject.current());
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+         return applicationBinary == null
+             ? LinuxApp.fromLinuxProject(FlutterProject.current().linux)
+             : LinuxApp.fromPrebuiltApp(applicationBinary);
+diff --git a/packages/flutter_tools/lib/src/flutter_cache.dart b/packages/flutter_tools/lib/src/flutter_cache.dart
+index 31f5fbc825a..46b8eb48b23 100644
+--- a/packages/flutter_tools/lib/src/flutter_cache.dart
++++ b/packages/flutter_tools/lib/src/flutter_cache.dart
+@@ -683,6 +683,7 @@ class FlutterRunnerDebugSymbols extends CachedArtifact {
+     }
+     await _downloadDebugSymbols('x64', artifactUpdater);
+     await _downloadDebugSymbols('arm64', artifactUpdater);
++    await _downloadDebugSymbols('riscv64', artifactUpdater);
+   }
+ }
+ 
+diff --git a/packages/flutter_tools/lib/src/flutter_features.dart b/packages/flutter_tools/lib/src/flutter_features.dart
+index c1102780346..ee7fb68b6ab 100644
+--- a/packages/flutter_tools/lib/src/flutter_features.dart
++++ b/packages/flutter_tools/lib/src/flutter_features.dart
+@@ -66,6 +66,9 @@ mixin FlutterFeatureFlagsIsEnabled implements FeatureFlags {
+ 
+   @override
+   bool get isUISceneMigrationEnabled => isEnabled(uiSceneMigration);
++
++  @override
++  bool get isRiscv64SupportEnabled => isEnabled(riscv64);
+ }
+ 
+ interface class FlutterFeatureFlags extends FeatureFlags with FlutterFeatureFlagsIsEnabled {
+diff --git a/packages/flutter_tools/lib/src/isolated/native_assets/native_assets.dart b/packages/flutter_tools/lib/src/isolated/native_assets/native_assets.dart
+index 1ed907c050a..86d0010f495 100644
+--- a/packages/flutter_tools/lib/src/isolated/native_assets/native_assets.dart
++++ b/packages/flutter_tools/lib/src/isolated/native_assets/native_assets.dart
+@@ -666,6 +666,7 @@ OS getNativeOSFromTargetPlatform(TargetPlatform platform) {
+       return OS.macOS;
+     case TargetPlatform.linux_x64:
+     case TargetPlatform.linux_arm64:
++    case TargetPlatform.linux_riscv64:
+       return OS.linux;
+     case TargetPlatform.windows_x64:
+     case TargetPlatform.windows_arm64:
+diff --git a/packages/flutter_tools/lib/src/isolated/native_assets/targets.dart b/packages/flutter_tools/lib/src/isolated/native_assets/targets.dart
+index cc0de9f2452..d036e29a352 100644
+--- a/packages/flutter_tools/lib/src/isolated/native_assets/targets.dart
++++ b/packages/flutter_tools/lib/src/isolated/native_assets/targets.dart
+@@ -69,6 +69,8 @@ sealed class AssetBuildTarget {
+         return _linuxTarget(supportedAssetTypes, Architecture.x64);
+       case TargetPlatform.linux_arm64:
+         return _linuxTarget(supportedAssetTypes, Architecture.arm64);
++      case TargetPlatform.linux_riscv64:
++        return _linuxTarget(supportedAssetTypes, Architecture.riscv64);
+       case TargetPlatform.windows_arm64:
+         return _windowsTarget(supportedAssetTypes, Architecture.arm64);
+       case TargetPlatform.darwin:
+@@ -402,6 +404,7 @@ List<AndroidArch> _androidArchs(TargetPlatform targetPlatform, String? androidAr
+     case TargetPlatform.fuchsia_x64:
+     case TargetPlatform.ios:
+     case TargetPlatform.linux_arm64:
++    case TargetPlatform.linux_riscv64:
+     case TargetPlatform.linux_x64:
+     case TargetPlatform.tester:
+     case TargetPlatform.web_javascript:
+diff --git a/packages/flutter_tools/lib/src/linux/build_linux.dart b/packages/flutter_tools/lib/src/linux/build_linux.dart
+index 6525bb9e61d..aa86e904948 100644
+--- a/packages/flutter_tools/lib/src/linux/build_linux.dart
++++ b/packages/flutter_tools/lib/src/linux/build_linux.dart
+@@ -163,6 +163,8 @@ Future<void> _runCmake(
+   final String buildFlag = sentenceCase(buildModeName);
+   final bool needCrossBuildOptionsForArm64 =
+       needCrossBuild && targetPlatform == TargetPlatform.linux_arm64;
++  final bool needCrossBuildOptionsForRiscv64 =
++      needCrossBuild && targetPlatform == TargetPlatform.linux_riscv64;
+   int result;
+   if (!globals.processManager.canRun('cmake')) {
+     throwToolExit(globals.userMessages.cmakeMissing);
+@@ -179,6 +181,9 @@ Future<void> _runCmake(
+       if (needCrossBuild) '-DFLUTTER_TARGET_PLATFORM_SYSROOT=$targetSysroot',
+       if (needCrossBuildOptionsForArm64) '-DCMAKE_C_COMPILER_TARGET=aarch64-linux-gnu',
+       if (needCrossBuildOptionsForArm64) '-DCMAKE_CXX_COMPILER_TARGET=aarch64-linux-gnu',
++      // Support cross-building for riscv64 targets on x64 hosts.
++      if (needCrossBuildOptionsForRiscv64) '-DCMAKE_C_COMPILER_TARGET=riscv64-linux-gnu',
++      if (needCrossBuildOptionsForRiscv64) '-DCMAKE_CXX_COMPILER_TARGET=riscv64-linux-gnu',
+       sourceDir.path,
+     ],
+     workingDirectory: buildDir.path,
+diff --git a/packages/flutter_tools/lib/src/linux/linux_device.dart b/packages/flutter_tools/lib/src/linux/linux_device.dart
+index a42d783ed09..b352cee0203 100644
+--- a/packages/flutter_tools/lib/src/linux/linux_device.dart
++++ b/packages/flutter_tools/lib/src/linux/linux_device.dart
+@@ -49,6 +49,8 @@ class LinuxDevice extends DesktopDevice {
+   late final Future<TargetPlatform> targetPlatform = () async {
+     if (_operatingSystemUtils.hostPlatform == HostPlatform.linux_x64) {
+       return TargetPlatform.linux_x64;
++    } else if (_operatingSystemUtils.hostPlatform == HostPlatform.linux_riscv64) {
++      return TargetPlatform.linux_riscv64;
+     }
+     return TargetPlatform.linux_arm64;
+   }();
+diff --git a/packages/flutter_tools/lib/src/mdns_discovery.dart b/packages/flutter_tools/lib/src/mdns_discovery.dart
+index b21795ddb3e..0840c95b637 100644
+--- a/packages/flutter_tools/lib/src/mdns_discovery.dart
++++ b/packages/flutter_tools/lib/src/mdns_discovery.dart
+@@ -599,6 +599,7 @@ class MDnsVmServiceDiscovery {
+       case TargetPlatform.fuchsia_arm64:
+       case TargetPlatform.fuchsia_x64:
+       case TargetPlatform.linux_arm64:
++      case TargetPlatform.linux_riscv64:
+       case TargetPlatform.linux_x64:
+       case TargetPlatform.tester:
+       case TargetPlatform.web_javascript:
+diff --git a/packages/flutter_tools/lib/src/resident_runner.dart b/packages/flutter_tools/lib/src/resident_runner.dart
+index 7fb86c0cc9a..10f58eedda8 100644
+--- a/packages/flutter_tools/lib/src/resident_runner.dart
++++ b/packages/flutter_tools/lib/src/resident_runner.dart
+@@ -1611,6 +1611,7 @@ Future<String?> getMissingPackageHintForPlatform(TargetPlatform platform) async
+     case TargetPlatform.fuchsia_arm64:
+     case TargetPlatform.fuchsia_x64:
+     case TargetPlatform.linux_arm64:
++    case TargetPlatform.linux_riscv64:
+     case TargetPlatform.linux_x64:
+     case TargetPlatform.tester:
+     case TargetPlatform.web_javascript:
+diff --git a/packages/flutter_tools/lib/src/runner/flutter_command.dart b/packages/flutter_tools/lib/src/runner/flutter_command.dart
+index 1c5811835d4..075d565eb58 100644
+--- a/packages/flutter_tools/lib/src/runner/flutter_command.dart
++++ b/packages/flutter_tools/lib/src/runner/flutter_command.dart
+@@ -2090,6 +2090,7 @@ DevelopmentArtifact? artifactFromTargetPlatform(TargetPlatform targetPlatform) {
+       return null;
+     case TargetPlatform.linux_x64:
+     case TargetPlatform.linux_arm64:
++    case TargetPlatform.linux_riscv64:
+       if (featureFlags.isLinuxEnabled) {
+         return DevelopmentArtifact.linux;
+       }
+diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/dart_plugin_registrant_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/dart_plugin_registrant_test.dart
+index b625816f366..11a7003a35c 100644
+--- a/packages/flutter_tools/test/general.shard/build_system/targets/dart_plugin_registrant_test.dart
++++ b/packages/flutter_tools/test/general.shard/build_system/targets/dart_plugin_registrant_test.dart
+@@ -90,6 +90,7 @@ void main() {
+         'darwin-x64': false,
+         'linux-x64': false,
+         'linux-arm64': false,
++        'linux-riscv64': false,
+         'windows-x64': false,
+         'web-javascript': true,
+         'ios': false,
+diff --git a/packages/flutter_tools/test/general.shard/cache_test.dart b/packages/flutter_tools/test/general.shard/cache_test.dart
+index f4743bb66a3..8b78ff91ddf 100644
+--- a/packages/flutter_tools/test/general.shard/cache_test.dart
++++ b/packages/flutter_tools/test/general.shard/cache_test.dart
+@@ -574,6 +574,7 @@ void main() {
+     expect(packageResolver.resolved, <List<String>>[
+       <String>['fuchsia-debug-symbols-x64', '123456'],
+       <String>['fuchsia-debug-symbols-arm64', '123456'],
++      <String>['fuchsia-debug-symbols-riscv64', '123456'],
+     ]);
+   });
+ 
+diff --git a/packages/flutter_tools/test/general.shard/flutter_validator_test.dart b/packages/flutter_tools/test/general.shard/flutter_validator_test.dart
+index 050bd3d6c6d..f0a864f0424 100644
+--- a/packages/flutter_tools/test/general.shard/flutter_validator_test.dart
++++ b/packages/flutter_tools/test/general.shard/flutter_validator_test.dart
+@@ -824,6 +824,9 @@ class FakeFlutterFeatures extends FeatureFlags {
+   @override
+   bool get isUISceneMigrationEnabled => _enabled;
+ 
++  @override
++  bool get isRiscv64SupportEnabled => _enabled;
++
+   @override
+   final List<Feature> allFeatures;
+ 
+diff --git a/packages/flutter_tools/test/src/fakes.dart b/packages/flutter_tools/test/src/fakes.dart
+index fe3e8730e1e..7df0fa1fe53 100644
+--- a/packages/flutter_tools/test/src/fakes.dart
++++ b/packages/flutter_tools/test/src/fakes.dart
+@@ -532,6 +532,7 @@ class TestFeatureFlags implements FeatureFlags {
+     this.isWindowingEnabled = false,
+     this.isLLDBDebuggingEnabled = false,
+     this.isUISceneMigrationEnabled = false,
++    this.isRiscv64SupportEnabled = false,
+   });
+ 
+   @override
+@@ -582,6 +583,9 @@ class TestFeatureFlags implements FeatureFlags {
+   @override
+   final bool isUISceneMigrationEnabled;
+ 
++  @override
++  final bool isRiscv64SupportEnabled;
++
+   @override
+   bool isEnabled(Feature feature) {
+     return switch (feature) {
+@@ -600,6 +604,7 @@ class TestFeatureFlags implements FeatureFlags {
+       windowingFeature => isWindowingEnabled,
+       lldbDebugging => isLLDBDebuggingEnabled,
+       uiSceneMigration => isUISceneMigrationEnabled,
++      riscv64 => isRiscv64SupportEnabled,
+       _ => false,
+     };
+   }
+@@ -622,6 +627,7 @@ class TestFeatureFlags implements FeatureFlags {
+     windowingFeature,
+     lldbDebugging,
+     uiSceneMigration,
++    riscv64,
+   ];
+ 
+   @override