github/workflows: Add CI to run tests against zephyr with qemu.

With this change, the zephyr port is tested against the standard test suite
via the following scheme:
- the zephyr port is built with the `qemu_cortex_m3` board and the
  `prj_minimal.conf` configuration
- `qemu-system-arm` runs `zephyr.elf`
- the zephyr console is redirected to a pts/pty
- `tests/run-tests.py` is run in bare-metal mode against the pts/pty device

This allows testing the zephyr port as though it were a physical board
attached over a serial port.
Signed-off-by: Damien George <damien@micropython.org>

.github/workflows/ports_zephyr.yml

@@ -27,3 +27,8 @@ jobs:
       run: source tools/ci.sh && ci_zephyr_install
     - name: Build
       run: source tools/ci.sh && ci_zephyr_build
+    - name: Run main test suite
+      run: source tools/ci.sh && ci_zephyr_run_tests
+    - name: Print failures
+      if: failure()
+      run: tests/run-tests.py --print-failures

tools/ci.sh

@@ -749,6 +749,11 @@ function ci_zephyr_setup {
       -w /micropython/ports/zephyr \
       zephyrprojectrtos/ci:${ZEPHYR_DOCKER_VERSION}
     docker ps -a
+
+    # qemu-system-arm is needed to run the test suite.
+    sudo apt-get update
+    sudo apt-get install qemu-system-arm
+    qemu-system-arm --version
 }
 
 function ci_zephyr_install {
@@ -763,3 +768,10 @@ function ci_zephyr_build {
     docker exec zephyr-ci west build -p auto -b mimxrt1050_evk
     docker exec zephyr-ci west build -p auto -b nucleo_wb55rg # for bluetooth
 }
+
+function ci_zephyr_run_tests {
+    docker exec zephyr-ci west build -p auto -b qemu_cortex_m3 -- -DCONF_FILE=prj_minimal.conf
+    # Issues with zephyr tests:
+    # - inf_nan_arith fails pow(-1, nan) test
+    (cd tests && ./run-tests.py --target minimal --device execpty:"qemu-system-arm -cpu cortex-m3 -machine lm3s6965evb -nographic -monitor null -serial pty -kernel ../ports/zephyr/build/zephyr/zephyr.elf" -d basics float --exclude inf_nan_arith)
+}