Set up automated build

.github/workflows/build.yml

@@ -0,0 +1,82 @@
+name: Build Image
+
+on:
+  push:
+    tags: [ '*' ]
+  pull_request:
+    branches: [ main ]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: linux-surface/grub-aarch64
+
+
+jobs:
+  build-grub:
+    name: Build GRUB Container
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Setup Docker buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Log into registry ${{ env.REGISTRY }}
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        id: build-and-push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+
+  build-image:
+    name: Build GRUB AArch64 Image
+
+    if: ${{ github.event_name != 'pull_request' }}
+    needs: [build-grub]
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Build GRUB AArch64 Image
+        run: |
+          docker pull ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}
+          docker run --rm -v "${PWD}/":/output                                  \
+              ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}  \
+              aarch64-grub-mkimage                                              \
+                  -O arm64-efi                                                  \
+                  -o /output/bootaa64.efi                                       \
+                  --prefix=                                                     \
+                  $(cat modules.txt)
+    
+      - name: Publish Release
+        uses: svenstaro/upload-release-action@v2
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          file: bootaa64.efi
+          tag: ${{ github.ref }}