Add SITL linux aarch64 build

.github/workflows/ci.yml

@@ -105,6 +105,37 @@ jobs:
           name: targets
           path: targets.txt
 
+  build-SITL-Linux-arm64:
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install dependencies
+        run: sudo apt-get update && sudo apt-get -y install ninja-build
+      - name: Setup environment
+        env:
+          ACTIONS_ALLOW_UNSECURE_COMMANDS: true
+        run: |
+          # This is the hash of the commit for the PR
+          # when the action is triggered by PR, empty otherwise
+          COMMIT_ID=${{ github.event.pull_request.head.sha }}
+          # This is the hash of the commit when triggered by push
+          # but the hash of refs/pull/<n>/merge, which is different
+          # from the hash of the latest commit in the PR, that's
+          # why we try github.event.pull_request.head.sha first
+          COMMIT_ID=${COMMIT_ID:-${{ github.sha }}}
+          BUILD_SUFFIX=ci-$(date '+%Y%m%d')-$(git rev-parse --short ${COMMIT_ID})
+          VERSION=$(grep project CMakeLists.txt|awk -F VERSION '{ gsub(/[ \t)]/, "", $2); print $2 }')
+          echo "BUILD_SUFFIX=${BUILD_SUFFIX}" >> $GITHUB_ENV
+          echo "BUILD_NAME=inav-${VERSION}-${BUILD_SUFFIX}" >> $GITHUB_ENV
+          echo "NUM_CORES=$(grep processor /proc/cpuinfo  | wc -l)" >> $GITHUB_ENV
+      - name: Build SITL
+        run: mkdir -p build_SITL && cd build_SITL && cmake -DSITL=ON -DWARNINGS_AS_ERRORS=ON -G Ninja .. && ninja -j${{ env.NUM_CORES }}
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ env.BUILD_NAME }}_SITL-Linux-aarch64
+          path: ./build_SITL/*_SITL
+
   build-SITL-Linux:
     runs-on: ubuntu-latest
     steps:

.github/workflows/nightly-build.yml

@@ -46,6 +46,12 @@ jobs:
           path: resources/sitl/linux
           pattern: inav-*SITIL-Linux
           merge-multiple: true
+      - name: download sitl linux aarch64
+        uses: actions/download-artifact@v4
+        with:
+          path: resources/sitl/linux/arm64
+          pattern: inav-*SITIL-Linux-aarch64
+          merge-multiple: true
       - name: download sitl windows
         uses: actions/download-artifact@v4
         with: