workflows: build: add build CI workflow

Signed-off-by: James Calligeros <[email protected]>

Author: chadmed

.github/workflows/build.yaml

@@ -0,0 +1,44 @@
+name: build
+
+on:
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+  workflow_call:
+    outputs:
+      installer_ver:
+        description: asahi-installer built version string
+        value: ${{ jobs.build.outputs.installer_ver }}
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    outputs:
+      installer_ver: ${{ steps.compile.outputs.installer_ver }}
+
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+          fetch-tags: true
+          submodules: recursive
+
+      - name: Install build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install --no-install-recommends -y gcc-aarch64-linux-gnu
+          sudo apt-get install --no-install-recommends -y 7zip jq
+          rustup target install aarch64-unknown-none-softfloat
+
+      - name: Build asahi-installer
+        id: compile
+        run: |
+          ./build.sh
+          echo "installer_ver=$(cat releases/latest).tar.gz" >> $GITHUB_OUTPUT
+
+      - name: Upload artefact
+        uses: actions/upload-artifact@v4
+        with:
+          name: installer-build
+          path: |
+            releases/*