From 9be0303493b69e61c654aa9ff0d5ad42f45faabf Mon Sep 17 00:00:00 2001
From: Kunlin Han <hi@iwktd.com>
Date: Mon, 22 Apr 2024 13:03:51 -0700
Subject: [PATCH] Add support for dumping vcd.

---
 bin/wsim               | 5 ++++-
 sim/verilator/Makefile | 7 +++++--
 testbench/testbench.sv | 4 ++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/bin/wsim b/bin/wsim
index 0796c51cd..8190b0e2c 100755
--- a/bin/wsim
+++ b/bin/wsim
@@ -23,6 +23,7 @@ parser.add_argument("--tb", "-t", help="Testbench", choices=["testbench", "testb
 parser.add_argument("--gui", "-g", help="Simulate with GUI", action="store_true")
 parser.add_argument("--coverage", "-c", help="Code & Functional Coverage", action="store_true")
 parser.add_argument("--args", "-a", help="Optional arguments passed to simulator via $value$plusargs", default="")
+parser.add_argument("--vcd", "-v", help="Generate testbench.vcd", action="store_true")
 args = parser.parse_args()
 print("Config=" + args.config + " tests=" + args.testsuite + " sim=" + args.sim + " gui=" + str(args.gui) + " args='" + args.args + "'")
 
@@ -37,6 +38,8 @@ if (args.coverage):
         print("Coverage option only available for Questa")
         exit(1)
 
+if (args.vcd):
+    args.args += " -DMAKEVCD=1"
 
 #  create the output sub-directories.
 WALLY = os.environ.get('WALLY')
@@ -67,6 +70,6 @@ if (args.sim == "questa"):
 elif (args.sim == "verilator"):
     # PWD=${WALLY}/sim CONFIG=rv64gc TESTSUITE=arch64i
     print(f"Running Verilator on {args.config} {args.testsuite}")
-    os.system(f"/usr/bin/make -C {regressionDir}/verilator WALLYCONF={args.config} TEST={args.testsuite}")
+    os.system(f"/usr/bin/make -C {regressionDir}/verilator WALLYCONF={args.config} TEST={args.testsuite} EXTRA_ARGS='{args.args}'")
 elif (args.sim == "vcs"):
     print("Running VCS on %s %s", args.config, args.testsuite)
diff --git a/sim/verilator/Makefile b/sim/verilator/Makefile
index f4f8c846f..97ebdfeb4 100644
--- a/sim/verilator/Makefile
+++ b/sim/verilator/Makefile
@@ -6,7 +6,8 @@ OPT=
 PARAMS?=-DVERILATOR=1 --no-trace-top
 NONPROF?=--stats
 VERILATOR_DIR=${WALLY}/sim/verilator
-SOURCE=${WALLY}/config/shared/*.vh ${WALLY}/config/${WALLYCONF} ${WALLY}/src/cvw.sv ${WALLY}/testbench/testbench.sv ${WALLY}/testbench/common/*.sv ${WALLY}/src/*/*.sv ${WALLY}/src/*/*/*.sv
+SOURCE=${WALLY}/config/shared/*.vh ${WALLY}/config/${WALLYCONF} ${WALLY}/src/cvw.sv ${WALLY}/testbench/*.sv ${WALLY}/testbench/common/*.sv ${WALLY}/src/*/*.sv ${WALLY}/src/*/*/*.sv
+EXTRA_ARGS=
 
 
 WALLYCONF?=rv64gc
@@ -43,8 +44,9 @@ run: wkdir/$(WALLYCONF)_$(TEST)/Vtestbench
 wkdir/$(WALLYCONF)_$(TEST)/Vtestbench: $(SOURCE)
 	verilator \
 	--Mdir wkdir/$(WALLYCONF)_$(TEST) -o Vtestbench \
-	--binary \
+	--binary --trace \
 	$(OPT) $(PARAMS) $(NONPROF) \
+	$(EXTRA_ARGS) \
 	--timescale "1ns/1ns" --timing --top-module testbench  --relative-includes \
 	"-I${WALLY}/config/shared" "-I${WALLY}/config/$(WALLYCONF)" \
 	${WALLY}/sim/verilator/wrapper.c \
@@ -57,6 +59,7 @@ obj_dir_profiling/Vtestbench_$(WALLYCONF): $(DEPENDENCIES)
 	--Mdir obj_dir_profiling -o Vtestbench_$(WALLYCONF) \
 	--binary \
 	--prof-cfuncs $(OPT) $(PARAMS) \
+	$(EXTRA_ARGS) \
 	--timescale "1ns/1ns" --timing --top-module testbench  --relative-includes \
 	$(INCLUDE_PATH) \
 	wrapper.c \
diff --git a/testbench/testbench.sv b/testbench/testbench.sv
index b74827165..3c638ee6c 100644
--- a/testbench/testbench.sv
+++ b/testbench/testbench.sv
@@ -225,6 +225,10 @@ module testbench;
       $display("TEST %s not supported in this configuration", TEST);
       $finish;
     end
+`ifdef MAKEVCD
+    $dumpfile("testbench.vcd");
+    $dumpvars;
+`endif
   end // initial begin
 
   // Model the testbench as an fsm.