From b4d1cd0348d27af6c1ace04bea4d65d5355a30d5 Mon Sep 17 00:00:00 2001
From: Nick Chan <towinchenmi@gmail.com>
Date: Tue, 24 Jan 2023 15:16:50 +0800
Subject: [PATCH] cache toolchain

---
 .github/workflows/build.yml | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 03059ef..a231319 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -73,13 +73,26 @@ jobs:
           sudo apt install -y pkg-config autoconf automake
           sudo pip3 install jsonschema jinja2
 
+      - name: Download toolchain checksum
+        run: |
+          curl -LO https://musl.cc/SHA512SUMS
+          echo "TOOLCHAIN_CHECKSUM="$(grep ${{ matrix.triple }}-cross.tgz SHA512SUMS | cut -d' ' -f1) >> $GITHUB_ENV
+
+      - name: Download toolchain (cached)
+        id: toolchain_cache
+        uses: actions/cache@v3
+        with:
+          path: ${{ matrix.triple }}-cross.tgz
+          key: ${{ matrix.triple }}-${{ env.TOOLCHAIN_CHECKSUM }}-toolchain
+
       - name: Download toolchain
+        if: steps.toolchain_cache.outputs.cache-hit != 'true'
         run: |
           curl -LO https://musl.cc/${{ matrix.triple }}-cross.tgz
-          tar -xf ${{ matrix.triple }}-cross.tgz
 
       - name: Setup environment
         run: |
+          tar -xf ${{ matrix.triple }}-cross.tgz
           mkdir sysroot
           echo "$(pwd)/${{ matrix.triple }}-cross/bin" >> $GITHUB_PATH
           case ${{ matrix.triple }} in