[Makefile & CI] Separate installation and Verilator test stages

- Split the Verilator model generation into a distinct verilate target for better modularity.
- Adjusted install to exclude Verilator-related tasks, focusing only on toolchain setup.
- Updated GitHub Actions workflow to include a dedicated Verilator step after compilation.
- Added a verilate function to .github/workflows/tools.sh for consistent environment setup and execution.

.github/workflows/scala.yml

@@ -61,6 +61,9 @@ jobs:
       - name: Compile
         run: sbt clean compile
 
+      - name: Verilate
+        run: source .github/workflows/tools.sh && verilate
+
       - name: Regression Test SIMULATOR
         run: |
           export NAXRISCV_REGRESSION_THREAD_COUNT=1

.github/workflows/tools.sh

@@ -83,3 +83,10 @@ install_all(){
   export NAXRISCV=${PWD}
   make install
 }
+
+verilate(){
+  export NAXRISCV=${PWD}
+  export VERILATOR_ROOT=${NAXRISCV}/toolchain/verilator-v4.216/bin
+  export PATH=${VERILATOR_ROOT}:$PATH
+  make verilate
+}

Makefile

@@ -113,8 +113,10 @@ src/test/cpp/naxriscv/obj_dir/VNaxRiscv:$(PRJ_NAX).v
 
 verilate-$(PRJ_NAX): src/test/cpp/naxriscv/obj_dir/VNaxRiscv
 
+verilate : verilate-$(PRJ_NAX)
+
 # install
-install:clean-install clean-toolchain install-toolchain verilate-$(PRJ_NAX)
+install:clean-install clean-toolchain install-toolchain
 	@echo " "
 	@echo "[SUCCESS] The entire toolchain is built with Success."
 	@echo "[SUCCESS] Generates the Verilator model for $(TARGET_NAX) NaxRiscv."