diff --git a/.github/workflows/flutter-engine-arm64.yaml b/.github/workflows/flutter-engine-arm64.yaml
index 24924bd..daab81f 100644
--- a/.github/workflows/flutter-engine-arm64.yaml
+++ b/.github/workflows/flutter-engine-arm64.yaml
@@ -19,7 +19,7 @@ jobs:
       arch:              arm64
       linux_cpu:         arm64
       target_triple:     aarch64-unknown-linux-gnu
-      target_sysroot:    debian_sid_arm64-sysroot
+      target_sysroot:    debian_bullseye_arm64-sysroot
       tag_debug:         linux-engine-sdk-debug-arm64-${{ inputs.srcrev }}
       tag_debug_unopt:   linux-engine-sdk-debug-unopt-arm64-${{ inputs.srcrev }}
       tag_release:       linux-engine-sdk-release-arm64-${{ inputs.srcrev }}
diff --git a/.github/workflows/flutter-engine-armv7hf.yaml b/.github/workflows/flutter-engine-armv7hf.yaml
index 8a7511b..e101bfd 100644
--- a/.github/workflows/flutter-engine-armv7hf.yaml
+++ b/.github/workflows/flutter-engine-armv7hf.yaml
@@ -19,7 +19,7 @@ jobs:
       arch:              arm
       linux_cpu:         arm --arm-float-abi hard
       target_triple:     armv7-unknown-linux-gnueabihf
-      target_sysroot:    debian_sid_arm-sysroot
+      target_sysroot:    debian_bullseye_arm-sysroot
       tag_debug:         linux-engine-sdk-debug-armv7hf-${{ inputs.srcrev }}
       tag_debug_unopt:   linux-engine-sdk-debug-unopt-armv7hf-${{ inputs.srcrev }}
       tag_release:       linux-engine-sdk-release-armv7hf-${{ inputs.srcrev }}
diff --git a/.github/workflows/flutter-engine-riscv64.yaml b/.github/workflows/flutter-engine-riscv64.yaml
new file mode 100644
index 0000000..d74993d
--- /dev/null
+++ b/.github/workflows/flutter-engine-riscv64.yaml
@@ -0,0 +1,256 @@
+name: Linux riscv64
+
+on:
+  workflow_dispatch:
+    inputs:
+      srcrev: 
+        description: 'Flutter Engine Commit Hash'
+        required: True
+        default: ''
+      release: 
+        description: 'Release'
+        required: false
+        default: 'false'
+
+jobs:
+  linux-riscv64:
+    runs-on: [self-hosted, linux, x64]
+    env:
+      arch:              riscv64
+      linux_cpu:         riscv64
+      target_triple:     riscv64-unknown-linux-gnu
+      target_sysroot:    debian_trixie_riscv64-sysroot
+      tag_debug:         linux-engine-sdk-debug-riscv64-${{ inputs.srcrev }}
+      tag_debug_unopt:   linux-engine-sdk-debug-unopt-riscv64-${{ inputs.srcrev }}
+      tag_release:       linux-engine-sdk-release-riscv64-${{ inputs.srcrev }}
+      tag_profile:       linux-engine-sdk-profile-riscv64-${{ inputs.srcrev }}
+      notes_debug:       "Flutter Engine - runtime debug SDK"
+      notes_debug_unopt: "Flutter Engine - runtime debug SDK"
+      notes_release:     "Flutter Engine - runtime release SDK"
+      notes_profile:     "Flutter Engine - runtime profile SDK"
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Install packages
+        run: |
+          git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
+
+      - name: Get Flutter Source
+        run: |
+          export PATH=$PATH:$PWD/depot_tools
+          export VPYTHON_VIRTUALENV_ROOT=$PWD/vpython
+          git clone https://github.com/flutter/flutter.git
+          pushd flutter
+          gclient config --spec 'solutions=[{"managed":False,"name":".","url":"https://github.com/flutter/flutter.git","custom_deps":{},"custom_vars":{"download_android_deps":False,"download_windows_deps":False,"download_linux_deps":True},"deps_file":"DEPS","safesync_url":""}]'
+          gclient sync --force --shallow --no-history -R -D --revision ${{ inputs.SRCREV }} -j$(nproc) -v
+          popd
+
+          # fetch sysroot
+          cd flutter/engine/src
+          build/linux/sysroot_scripts/install-sysroot.py --arch=$arch
+
+      - name: Patch Flutter Source
+        run: |
+          PATCH_DIR=$PWD/patches
+          cd flutter
+          git apply $PATCH_DIR/0001-clang-toolchain.patch
+      
+      - name: Build Debug
+        working-directory: flutter/engine/src
+        run: |
+          export PATH=$PATH:$PWD/../../../depot_tools
+          export VPYTHON_VIRTUALENV_ROOT=$PWD/../../../vpython
+          CLANG_ROOT=$(find -iname clang++)
+          CLANG_ROOT=$(dirname $CLANG_ROOT)
+          export CLANG_ROOT=$(dirname $CLANG_ROOT)
+          ./flutter/tools/gn --runtime-mode=debug \
+            --embedder-for-target \
+            --no-build-embedder-examples \
+            --no-goma --no-rbe \
+            --no-stripped --no-enable-unittests \
+            --no-dart-version-git-info \
+            --linux-cpu $linux_cpu \
+            --target-os linux \
+            --target-sysroot $PWD/build/linux/$target_sysroot \
+            --target-toolchain $PWD/$CLANG_ROOT \
+            --target-triple $target_triple
+          ninja -C out/linux_debug_$arch
+
+      - name: Prepare Debug Artifacts
+        run: |
+          scripts/prepare-sdk-$arch.sh flutter/engine/src/out/linux_debug_$arch $PWD/flutter/engine/src/build/linux/$target_sysroot
+
+          tar czfhv $tag_debug.tar.gz              flutter/engine/src/out/linux_debug_$arch/engine-sdk/
+
+          sha256sum -b $tag_debug.tar.gz         > $tag_debug.tar.gz.sha256
+
+      - name: Publish Debug
+        if: ${{ inputs.release != 'true' }}
+        uses: actions/upload-artifact@v4
+        with:
+            name: engine-sdk-debug
+            path: |
+              linux-engine-sdk-debug-riscv64-${{ inputs.srcrev }}.tar.gz
+              linux-engine-sdk-debug-riscv64-${{ inputs.srcrev }}.tar.gz.sha256
+
+      - name: Release - Debug Release
+        if: ${{ inputs.release == 'true' }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+        run: |
+          gh release delete "$tag_debug" --cleanup-tag -y |true
+          gh release create --draft "$tag_debug" --title "$tag_debug" --notes "$notes_debug"
+          gh release upload "$tag_debug" "$tag_debug.tar.gz" "$tag_debug.tar.gz.sha256"
+          gh release edit "$tag_debug" --draft=false
+
+      - name: Build Debug Unoptimized
+        working-directory: flutter/engine/src
+        run: |
+          export PATH=$PATH:$PWD/../../../depot_tools
+          export VPYTHON_VIRTUALENV_ROOT=$PWD/../../../vpython
+          CLANG_ROOT=$(find -iname clang++)
+          CLANG_ROOT=$(dirname $CLANG_ROOT)
+          export CLANG_ROOT=$(dirname $CLANG_ROOT)
+          ./flutter/tools/gn --runtime-mode=debug \
+            --unoptimized \
+            --embedder-for-target \
+            --no-build-embedder-examples \
+            --no-goma --no-rbe \
+            --no-stripped --no-enable-unittests \
+            --no-dart-version-git-info \
+            --linux-cpu $linux_cpu \
+            --target-os linux \
+            --target-sysroot $PWD/build/linux/$target_sysroot \
+            --target-toolchain $PWD/$CLANG_ROOT \
+            --target-triple $target_triple
+          ninja -C out/linux_debug_unopt_$arch
+
+      - name: Prepare Debug Unoptimized Artifacts
+        run: |
+          scripts/prepare-sdk-$arch.sh flutter/engine/src/out/linux_debug_unopt_$arch $PWD/flutter/engine/src/build/linux/$target_sysroot
+
+          tar czfhv $tag_debug_unopt.tar.gz              flutter/engine/src/out/linux_debug_unopt_$arch/engine-sdk/
+
+          sha256sum -b $tag_debug_unopt.tar.gz         > $tag_debug_unopt.tar.gz.sha256
+
+      - name: Publish Debug Unoptimized
+        if: ${{ inputs.release != 'true' }}
+        uses: actions/upload-artifact@v4
+        with:
+            name: engine-sdk-debug-unoptimized
+            path: |
+              linux-engine-sdk-debug-unopt-riscv64-${{ inputs.srcrev }}.tar.gz
+              linux-engine-sdk-debug-unopt-riscv64-${{ inputs.srcrev }}.tar.gz.sha256
+
+      - name: Release - Debug Unoptimized Release
+        if: ${{ inputs.release == 'true' }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+        run: |
+          gh release delete "$tag_debug_unopt" --cleanup-tag -y |true
+          gh release create --draft "$tag_debug_unopt" --title "$tag_debug_unopt" --notes "$notes_debug_unopt"
+          gh release upload "$tag_debug_unopt" "$tag_debug_unopt.tar.gz" "$tag_debug_unopt.tar.gz.sha256"
+          gh release edit "$tag_debug_unopt" --draft=false
+
+      - name: Build Release
+        working-directory: flutter/engine/src
+        run: |
+          export PATH=$PATH:$PWD/../../../depot_tools
+          export VPYTHON_VIRTUALENV_ROOT=$PWD/../../../vpython
+          CLANG_ROOT=$(find -iname clang++)
+          CLANG_ROOT=$(dirname $CLANG_ROOT)
+          export CLANG_ROOT=$(dirname $CLANG_ROOT)
+          ./flutter/tools/gn --runtime-mode=release \
+            --embedder-for-target \
+            --no-build-embedder-examples \
+            --no-goma --no-rbe \
+            --no-stripped --no-enable-unittests \
+            --no-dart-version-git-info \
+            --linux-cpu $linux_cpu \
+            --target-os linux \
+            --target-sysroot $PWD/build/linux/$target_sysroot \
+            --target-toolchain $PWD/$CLANG_ROOT \
+            --target-triple $target_triple
+          ninja -C out/linux_release_$arch
+
+      - name: Prepare Release Artifacts
+        run: |
+          scripts/prepare-sdk-$arch.sh flutter/engine/src/out/linux_release_$arch $PWD/flutter/engine/src/build/linux/$target_sysroot
+
+          tar czfhv $tag_release.tar.gz flutter/engine/src/out/linux_release_$arch/engine-sdk/
+
+          sha256sum -b $tag_release.tar.gz > $tag_release.tar.gz.sha256
+
+      - name: Publish Release
+        if: ${{ inputs.release != 'true' }}
+        uses: actions/upload-artifact@v4
+        with:
+            name: engine-sdk-release
+            path: |
+              linux-engine-sdk-release-riscv64-${{ inputs.srcrev }}.tar.gz
+              linux-engine-sdk-release-riscv64-${{ inputs.srcrev }}.tar.gz.sha256
+
+      - name: Release - Publish Release
+        if: ${{ inputs.release == 'true' }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+        run: |
+          gh release delete "$tag_release" --cleanup-tag -y |true
+          gh release create --draft "$tag_release" --title "$tag_release" --notes "$notes_release"
+          gh release upload "$tag_release" "$tag_release.tar.gz" "$tag_release.tar.gz.sha256"
+          gh release edit "$tag_release" --draft=false
+
+      - name: Build Profile
+        working-directory: flutter/engine/src
+        run: |
+          export PATH=$PATH:$PWD/../../../depot_tools
+          export VPYTHON_VIRTUALENV_ROOT=$PWD/../../../vpython
+          CLANG_ROOT=$(find -iname clang++)
+          CLANG_ROOT=$(dirname $CLANG_ROOT)
+          export CLANG_ROOT=$(dirname $CLANG_ROOT)
+          ./flutter/tools/gn --runtime-mode=profile \
+            --embedder-for-target \
+            --no-build-embedder-examples \
+            --no-goma --no-rbe \
+            --no-stripped --no-enable-unittests \
+            --no-dart-version-git-info \
+            --linux-cpu $linux_cpu \
+            --target-os linux \
+            --target-sysroot $PWD/build/linux/$target_sysroot \
+            --target-toolchain $PWD/$CLANG_ROOT \
+            --target-triple $target_triple
+          ninja -C out/linux_profile_$arch
+
+      - name: Prepare Profile Artifacts
+        run: |
+          scripts/prepare-sdk-$arch.sh flutter/engine/src/out/linux_profile_$arch $PWD/flutter/engine/src/build/linux/$target_sysroot
+
+          tar czfhv $tag_profile.tar.gz flutter/engine/src/out/linux_profile_$arch/engine-sdk/
+
+          sha256sum -b $tag_profile.tar.gz > $tag_profile.tar.gz.sha256
+
+      - name: Publish Profile
+        if: ${{ inputs.release != 'true' }}
+        uses: actions/upload-artifact@v4
+        with:
+            name: engine-sdk-profile
+            path: |
+              linux-engine-sdk-profile-riscv64-${{ inputs.srcrev }}.tar.gz
+              linux-engine-sdk-profile-riscv64-${{ inputs.srcrev }}.tar.gz.sha256
+
+      - name: Release - Publish Profile
+        if: ${{ inputs.release == 'true' }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+          GH_REPO: ${{ github.repository }}
+        run: |
+          gh release delete "$tag_profile" --cleanup-tag -y |true
+          gh release create --draft "$tag_profile" --title "$tag_profile" --notes "$notes_profile"
+          gh release upload "$tag_profile" "$tag_profile.tar.gz" "$tag_profile.tar.gz.sha256"
+          gh release edit "$tag_profile" --draft=false
diff --git a/.github/workflows/flutter-engine-x86_64.yaml b/.github/workflows/flutter-engine-x86_64.yaml
index 49d778e..3355ecd 100644
--- a/.github/workflows/flutter-engine-x86_64.yaml
+++ b/.github/workflows/flutter-engine-x86_64.yaml
@@ -19,7 +19,7 @@ jobs:
       arch:              x64
       linux_cpu:         x64
       target_triple:     x86_64-unknown-linux-gnu
-      target_sysroot:    debian_sid_amd64-sysroot
+      target_sysroot:    debian_bullseye_amd64-sysroot
       tag_debug:         linux-engine-sdk-debug-x86_64-${{ inputs.srcrev }}
       tag_debug_unopt:   linux-engine-sdk-debug-unopt-x86_64-${{ inputs.srcrev }}
       tag_release:       linux-engine-sdk-release-x86_64-${{ inputs.srcrev }}