Added a GitHub Action to generate all needed Buildroot images.

Signed-off-by: RICCIARDI-Adrien <adrien.ricciardi@hotmail.fr>

.github/workflows/generate_images.yml

@@ -0,0 +1,34 @@
+name: Generate prebuilt images
+on: [push, pull_request]
+
+jobs:
+  buildroot:
+    name: Build
+    runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        defconfig_name: [qemu_x86_defconfig, qemu_x86_64_defconfig, raspberrypi4_defconfig, raspberrypi4_64_defconfig, qemu_ppc64le_pseries_defconfig, qemu_mips32r2_malta_defconfig, qemu_mips64_malta_defconfig]
+        libc_name: [glibc, uclibc, musl]
+    env:
+      BUILDROOT_DIRECTORY_NAME: /home/runner/buildroot-${{ matrix.defconfig_name }}-${{ matrix.libc_name }}
+    permissions:
+      contents: write
+    steps:
+      - name: Retrieve CI scripts
+        uses: actions/checkout@v4
+      - name: Run build script
+        run: |
+          bash -x ${{ github.workspace }}/build-image.sh ${{ matrix.defconfig_name }} ${{ matrix.libc_name }} /home/runner
+      - name: Archive image
+        run: |
+          tar -c ${{ env.BUILDROOT_DIRECTORY_NAME }} -f ${{ env.BUILDROOT_DIRECTORY_NAME }}.tar
+      - name: Compress image
+        run: |
+          zstd -T0 -19 --rm -v ${{ env.BUILDROOT_DIRECTORY_NAME }}.tar
+      - name: Deploy image to repository release
+        if: startsWith(github.ref, 'refs/tags')
+        uses: softprops/action-gh-release@v1
+        with:
+          files: ${{ env.BUILDROOT_DIRECTORY_NAME }}.tar.zst
+          name: ${{ github.ref_name }}
+          tag_name: ${{ github.ref_name }}