Compile wheels for Raspberry Pi 1-3

.ci/Dockerfile.armv7l

@@ -13,7 +13,16 @@ RUN /bin/bash -c 'source .ci/ubuntu_ci.sh && \
     install_python && \
     install_kivy_test_run_pip_deps'
 
+# Download the Raspberry Pi firmware if we are targeting the Raspberry Pi 1-3.
+ARG KIVY_CROSS_PLATFORM=""
+ARG KIVY_CROSS_SYSROOT=""
+RUN if [ "$KIVY_CROSS_PLATFORM" = "rpi" ]; then \
+        apt-get -y install git; \
+        git clone --depth=1 https://github.com/raspberrypi/firmware "$KIVY_CROSS_SYSROOT"; \
+        ln -s "$KIVY_CROSS_SYSROOT"/opt/vc "$KIVY_CROSS_SYSROOT"/usr; \
+    fi
+
 # Build the wheel.
-RUN KIVY_SPLIT_EXAMPLES=1 VIDEOCOREMESA=1 python3 -m pip -v wheel --extra-index-url https://www.piwheels.org/simple . -w /kivy-wheel
+RUN KIVY_SPLIT_EXAMPLES=1 VIDEOCOREMESA=1 KIVY_CROSS_PLATFORM="$KIVY_CROSS_PLATFORM" KIVY_CROSS_SYSROOT="$KIVY_CROSS_SYSROOT" python3 -m pip -v wheel --extra-index-url https://www.piwheels.org/simple . -w /kivy-wheel
 
 RUN [ "cross-build-end" ]

.ci/ubuntu_ci.sh

@@ -90,17 +90,24 @@ generate_manylinux2010_wheels() {
 generate_armv7l_wheels() {
   image=$1
 
-  mkdir dist dist_armv6l
-  docker build -f .ci/Dockerfile.armv7l -t kivy/kivy-armv7l --build-arg image="$image" .
+  mkdir dist
+  docker build -f .ci/Dockerfile.armv7l -t kivy/kivy-armv7l --build-arg image="$image" --build-arg KIVY_CROSS_PLATFORM="$2" --build-arg KIVY_CROSS_SYSROOT="$3" .
   docker cp "$(docker create kivy/kivy-armv7l)":/kivy-wheel .
   cp kivy-wheel/Kivy-* dist/
 
+  # Rename the special wheels for the Raspberry Pi 1-3
+  if [ "$#" -gt 1 ]; then
+    for name in dist/*.whl; do
+      new_name="${name/-cp/.rpi123-cp}"
+      mv -n "$name" "$new_name"
+    done
+  fi
+
   # Create a copy with the armv6l suffix
-  cp dist/*armv7l.whl dist_armv6l/
-  sudo apt-get -y install rename
-  rename 's/armv7l/armv6l/' dist_armv6l/*armv7l.whl
-  mv dist_armv6l/*armv6l.whl dist/
-  rmdir dist_armv6l
+  for name in dist/*.whl; do
+    new_name="${name/armv7l/armv6l}"
+    cp -n "$name" "$new_name"
+  done
 }
 
 rename_wheels() {
@@ -112,12 +119,12 @@ rename_wheels() {
     -c "import kivy; _, tag, n = kivy.parse_kivy_version(kivy.__version__); print(tag + n) if n is not None else print(tag or 'something')" \
     --config "kivy:log_level:error")
   echo "tag_name=$tag_name"
-  wheel_name="$tag_name.$wheel_date.$git_tag-"
+  wheel_name="$tag_name.$wheel_date.$git_tag"
   echo "wheel_name=$wheel_name"
 
   ls dist/
   for name in dist/*.whl; do
-    new_name="${name/$tag_name-/$wheel_name}"
+    new_name="${name/$tag_name/$wheel_name}"
     if [ ! -f "$new_name" ]; then
       cp -n "$name" "$new_name"
     fi

.github/workflows/rpi_wheels.yml

@@ -9,20 +9,27 @@ on:
 
 env:
   SERVER_IP: '159.203.106.198'
+  KIVY_CROSS_PLATFORM: 'rpi'
+  KIVY_CROSS_SYSROOT: '/rpi-firmware'
 
 jobs:
   raspberrypi:
     runs-on: ubuntu-18.04
     if: github.event_name == 'schedule' || (github.event_name == 'create' && github.event.ref_type == 'tag') || contains(github.event.head_commit.message, '[build wheel]') || contains(github.event.head_commit.message, '[build wheel armv7l]') || contains(github.event.pull_request.title, '[build wheel]') || contains(github.event.pull_request.title, '[build wheel armv7l]')
     strategy:
       matrix:
+        platform: ['rpi123', 'rpi4']
         docker_images: ['balenalib/armv7hf-debian:stretch', 'balenalib/armv7hf-debian:buster']
     steps:
     - uses: actions/checkout@v1
     - name: Make ${{ matrix.docker_images }} wheel
       run: |
         source .ci/ubuntu_ci.sh
-        generate_armv7l_wheels ${{ matrix.docker_images }}
+        if [ "${{ matrix.platform }}" == "rpi123" ]; then
+          generate_armv7l_wheels ${{ matrix.docker_images }} "$KIVY_CROSS_PLATFORM" "$KIVY_CROSS_SYSROOT"
+        else
+          generate_armv7l_wheels ${{ matrix.docker_images }}
+        fi
     - name: Rename wheels
       if: github.event.ref_type != 'tag'
       run: |