[CI] - add GitHub action for building the firmware. (#18)

Author: aentinger

.github/workflows/smoke-test.yml

@@ -0,0 +1,28 @@
+name: Build
+
+# See: https://docs.github.com/en/actions/reference/events-that-trigger-workflows
+on:
+  push:
+  pull_request:
+  schedule:
+    # Run every Tuesday at 8 AM UTC
+    - cron: "0 8 * * TUE"
+  workflow_dispatch:
+  repository_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  smoke-test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install arm-none-eabi-gcc
+        run: sudo apt-get update && sudo apt-get install gcc-arm-none-eabi
+
+      - name: Build firmware with make
+        run: make

README.md

@@ -1,5 +1,7 @@
 :floppy_disk: `portentax8-stm32h7-fw`
 =====================================
+[![Smoke test status](https://github.com/https://github.com/arduino/portentax8-stm32h7-fw/actions/workflows/smoke-test.yml/badge.svg)](https://github.com/https://github.com/arduino/portentax8-stm32h7-fw/actions/workflows/smoke-test.yml)
+
 This repository contains the firmware running on the `STM32H747AIIX`/Cortex-M7 core which, in combination with loadable kernel modules within the Linux distribution, provides access to various IO busses on the expansion headers of the Portenta X8.
 
 ### Developer Guide