From d0ee2860a329da22348e8b1e2ec5ebfa6990c15f Mon Sep 17 00:00:00 2001
From: Cameron Brooks <cambrooks3393@gmail.com>
Date: Tue, 14 Jul 2026 23:22:57 -0400
Subject: [PATCH] ci: build firmware for all board variants on firmware changes

The existing CI validates slice.yaml only - firmware changes merged
with no build check at all, which is how a build-breaking change
could land silently (the anolis bench campaign's padded-read
regression era made the gap visible). Build all four board variants
(gen1/gen2 x nano/nanoevery) via PlatformIO on any firmware/ change,
with the PlatformIO toolchain cached.
---
 .github/workflows/firmware-build.yml | 41 ++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 .github/workflows/firmware-build.yml

diff --git a/.github/workflows/firmware-build.yml b/.github/workflows/firmware-build.yml
new file mode 100644
index 0000000..489c1d2
--- /dev/null
+++ b/.github/workflows/firmware-build.yml
@@ -0,0 +1,41 @@
+name: Firmware Build
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "firmware/**"
+      - ".github/workflows/firmware-build.yml"
+  pull_request:
+    paths:
+      - "firmware/**"
+      - ".github/workflows/firmware-build.yml"
+  workflow_dispatch:
+
+jobs:
+  build:
+    name: pio run (${{ matrix.env }})
+    runs-on: ubuntu-24.04
+    strategy:
+      fail-fast: false
+      matrix:
+        env: [gen1_nano, gen2_nano, gen1_nanoevery, gen2_nanoevery]
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Cache PlatformIO
+        uses: actions/cache@v4
+        with:
+          path: ~/.platformio
+          key: pio-${{ runner.os }}-${{ matrix.env }}-${{ hashFiles('firmware/platformio.ini') }}
+
+      - name: Install PlatformIO
+        run: pip install platformio
+
+      - name: Build
+        working-directory: firmware
+        run: pio run -e ${{ matrix.env }}