Initial implementation of simradio-based testing with a multi-node simulated mesh

.github/workflows/ci.yml

@@ -70,3 +70,26 @@ jobs:
           pip3 install poetry
           poetry install
           poetry run meshtastic --version
+
+  firmware:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Python 3
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Install meshtastic from local
+        run: |
+          python -m pip install --upgrade pip
+          pip3 install poetry
+          poetry install --all-extras --with dev
+          poetry run meshtastic --version
+      - name: Install meshtasticd (beta) from PPA
+        run: |
+          sudo add-apt-repository -y ppa:meshtastic/beta
+          sudo apt-get update
+          sudo apt-get install -y meshtasticd
+      - name: Run firmware smoke tests
+        run: poetry run pytest -m "smokevirt or smokemesh" -v
+        timeout-minutes: 15

meshtastic/tests/conftest.py

@@ -8,6 +8,56 @@
 from meshtastic import mt_config
 
 from ..mesh_interface import MeshInterface
+from .firmware_harness import (
+    CHAIN_TOPOLOGY,
+    DEFAULT_BASE_PORT,
+    SimMesh,
+    find_meshtasticd,
+    is_compatible_host,
+)
+
+# Use a different base port for the single-node fixture so it doesn't
+# conflict with the multi-node mesh fixture (both are session-scoped).
+SINGLE_NODE_BASE_PORT = DEFAULT_BASE_PORT + 100
+
+
+def _skip_firmware_if_unavailable() -> None:
+    """Skip the test when meshtasticd can't run on this host."""
+    if not is_compatible_host():
+        pytest.skip("meshtasticd firmware tests require Linux")
+    if find_meshtasticd() is None:
+        pytest.skip(
+            "meshtasticd not found — set MESHTASTICD_BIN or install it on PATH"
+        )
+
+
+@pytest.fixture(scope="session")
+def firmware_node():
+    """A single meshtasticd sim node for smokevirt tests.
+
+    Yields the SimNode instance.  The node is booted with a fresh erased
+    config and listens on localhost at its TCP port.
+    """
+    _skip_firmware_if_unavailable()
+    mesh = SimMesh(n_nodes=1, base_port=SINGLE_NODE_BASE_PORT)
+    mesh.start()
+    yield mesh.get_node(0)
+    mesh.stop()
+
+
+@pytest.fixture(scope="function")
+def firmware_mesh():
+    """A 3-node chain (A-B-C) meshtasticd sim mesh for smokemesh tests.
+
+    Yields the SimMesh instance.  Nodes are connected and the SIMULATOR_APP
+    packet bridge is running.  Node DB convergence is awaited.
+    """
+    _skip_firmware_if_unavailable()
+    mesh = SimMesh(n_nodes=3, topology=CHAIN_TOPOLOGY)
+    mesh.start()
+    mesh.wait_for_convergence(timeout=30)
+    yield mesh
+    mesh.stop()
 
 
 @pytest.fixture