diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d7a849467..fdd92ca31 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -21,6 +21,18 @@ jobs:
           - platform: hifive_unmatched
             bits: 32
 
+    # Output cache keys that were used so we can consolidate them later. Note
+    # that this is a matrix job, and job outputs for these are not well supported
+    # at all in Github Actions (https://github.com/orgs/community/discussions/26639).
+    # Essentially, the last job to set these output variables will win, which is
+    # not always great. In our case, though, this is actually fine since we don't
+    # necessarily need "precise" matching here -- any job's output should be good
+    # enough to serve as a future key into the cache.
+    outputs:
+      buildroot-dl-key: ${{ steps.restore-buildroot-dl.outputs.cache-primary-key }}
+      ccache-key: ${{ steps.restore-ccache.outputs.cache-primary-key }}
+      ymdh: ${{ steps.cache-keys.outputs.YMDH }}
+
     steps:
 
 ###########
@@ -54,26 +66,33 @@ jobs:
     # much always be using the max Github Action cache limit (10GB), but this is okay
     # since we really only care about keeping the latest cache anyways.
     - name: Restore buildroot packages
-      uses: actions/cache@v3
+      id: restore-buildroot-dl
+      uses: actions/cache/restore@v3
       with:
-        path: buildroot/dl
-        key: buildroot-dl-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.YMDH }}
+        path: dl.tar
+        key: buildroot-dl-${{ steps.cache-keys.outputs.YMDH }}
         restore-keys: |
-          buildroot-dl-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.YMD }}
-          buildroot-dl-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.YM }}
-          buildroot-dl-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.Y }}
-          buildroot-dl-${{ matrix.platform }}${{ matrix.bits }}-
+          buildroot-dl-${{ steps.cache-keys.outputs.YMD }}
+          buildroot-dl-${{ steps.cache-keys.outputs.YM }}
+          buildroot-dl-${{ steps.cache-keys.outputs.Y }}
+          buildroot-dl-
 
     - name: Restore ccache
-      uses: actions/cache@v3
+      id: restore-ccache
+      uses: actions/cache/restore@v3
       with:
-        path: ~/.buildroot-ccache
-        key: ccache-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.YMDH }}
+        path: ccache.tar.xz
+        key: ccache-${{ steps.cache-keys.outputs.YMDH }}
         restore-keys: |
-          ccache-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.YMD }}
-          ccache-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.YM }}
-          ccache-${{ matrix.platform }}${{ matrix.bits }}-${{ steps.cache-keys.outputs.Y }}
-          ccache-${{ matrix.platform }}${{ matrix.bits }}-
+          ccache-${{ steps.cache-keys.outputs.YMD }}
+          ccache-${{ steps.cache-keys.outputs.YM }}
+          ccache-${{ steps.cache-keys.outputs.Y }}
+          ccache-
+
+    - name: Decompress caches
+      run: |
+        if [[ -f dl.tar ]] ; then tar -xf dl.tar -C buildroot ; fi
+        if [[ -f ccache.tar.xz ]]; then tar -xf ccache.tar.xz -C ~ ; fi
 
 ##############
 ## Keystone ##
@@ -108,12 +127,95 @@ jobs:
 
         tar -cf - $COMPRESSDIRS | xz -9 -T0 > build.tar.xz
 
+    - name: Compress cache directories
+      run: |
+        tar -C buildroot --exclude='**/git' -cf dl.tar dl/
+        tar -C ~ -cf - .buildroot-ccache | xz -9 -T0 > ccache.tar.xz
+
     - name: Upload build directory
       uses: actions/upload-artifact@v4
       with:
         name: keystone-${{ matrix.platform }}${{ matrix.bits }}-builddir
         path: build.tar.xz
         retention-days: 1
+        compression-level: 0
+
+    - name: Upload buildroot download directory
+      uses: actions/upload-artifact@v4
+      with:
+        name: keystone-${{ matrix.platform }}${{ matrix.bits }}-buildroot-dl
+        path: dl.tar
+        retention-days: 1
+        compression-level: 0
+
+    - name: Upload ccache directory
+      uses: actions/upload-artifact@v4
+      with:
+        name: keystone-${{ matrix.platform }}${{ matrix.bits }}-ccache
+        path: ccache.tar.xz
+        retention-days: 1
+        compression-level: 0
+
+###############
+## Utilities ##
+###############
+
+  # Combine cache directories to save space
+  combine-caches:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Install dependencies
+        run: |
+          sudo apt-get -y update && sudo apt-get -y install ccache
+
+      # First, fetch the caches themselves
+      - name: Prepare output directories
+        run: |
+          mkdir -p buildroot/dl/ ~/.buildroot-ccache/
+
+      - name: Fetch buildroot caches
+        uses: actions/download-artifact@v4
+        with:
+          pattern: keystone-*-buildroot-dl
+
+      - name: Fetch ccache caches
+        uses: actions/download-artifact@v4
+        with:
+          pattern: keystone-*-ccache
+
+      # Then, combine the caches
+      - name: Merge caches
+        run: |
+          for d in keystone-*-buildroot-dl; do
+            tar --skip-old-files -xf "$d/dl.tar" -C buildroot
+          done
+
+          RESULTDIR=""$HOME/.buildroot-ccache"
+          for d in keystone-*-ccache; do
+            TMPDIR=$(mktemp -d)
+            tar -xf "$d/ccache.tar.xz" -C "$TMPDIR"
+            ( cd "$TMPDIR/.buildroot-ccache" ; cp -a --parents ? "$RESULTDIR" )
+            rm -rf "$TMPDIR"
+          done
+          ccache -d "$RESULTDIR" -c
+
+      - name: Recompress caches
+        run: |
+          tar -C buildroot --exclude='**/git' -cf dl.tar dl/
+          tar -C ~ -cf - .buildroot-ccache | xz -9 -T0 > ccache.tar.xz
+
+      - name: Save buildroot download cache
+        uses: actions/cache/save@v3
+        with:
+          path: dl.tar
+          key: ${{ needs.build.outputs.buildroot-dl-key }}
+
+      - name: Save ccache
+        uses: actions/cache/save@v3
+        with:
+          path: ccache.tar.xz
+          key: ${{ needs.build.outputs.ccache-key }}
 
 ###########
 ## Tests ##
diff --git a/mkutils/plat/generic/run.mk b/mkutils/plat/generic/run.mk
index 6b02e6f8f..45db1bb5e 100644
--- a/mkutils/plat/generic/run.mk
+++ b/mkutils/plat/generic/run.mk
@@ -34,6 +34,7 @@ call:
 	$(call log,info,Calling command in QEMU)
 	ssh -i $(BUILDROOT_BUILDDIR)/target/root/.ssh/id-rsa \
 		-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null \
+		-o ConnectTimeout=5 \
 		-p $(QEMU_PORT) root@localhost $(KEYSTONE_COMMAND) 2>&1 | \
 		 grep -v "Warning: Permanently added" | tee -a $(CALL_LOGFILE)