From 3f55fb4ccbe51ff57f4ec71050b63f6fcd519bc1 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Fri, 25 May 2018 13:04:49 +0200
Subject: [PATCH] Improve testbench_verilator

Signed-off-by: Clifford Wolf <clifford@clifford.at>
---
 Makefile    |  8 +++++---
 testbench.v | 41 +++++++++++++++++++++++++----------------
 2 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/Makefile b/Makefile
index 7beffd8..2c14263 100644
--- a/Makefile
+++ b/Makefile
@@ -71,8 +71,9 @@ testbench_synth.vvp: testbench.v synth.v
 	chmod -x $@
 
 testbench_verilator: testbench.v picorv32.v
-	verilator -Wno-lint -Wno-MULTIDRIVEN -trace --top-module picorv32_wrapper --cc testbench.v picorv32.v --exe testbench.cc $(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA))
-	$(MAKE) -C obj_dir -f Vpicorv32_wrapper.mk
+	verilator --cc --exe -Wno-lint -trace --top-module picorv32_wrapper testbench.v picorv32.v testbench.cc \
+			$(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA)) --Mdir testbench_verilator_dir
+	$(MAKE) -C testbench_verilator_dir -f Vpicorv32_wrapper.mk
 	cp obj_dir/Vpicorv32_wrapper testbench_verilator
 
 check: check-yices
@@ -170,6 +171,7 @@ clean:
 	rm -vrf $(FIRMWARE_OBJS) $(TEST_OBJS) check.smt2 check.vcd synth.v synth.log \
 		firmware/firmware.elf firmware/firmware.bin firmware/firmware.hex firmware/firmware.map \
 		testbench.vvp testbench_sp.vvp testbench_synth.vvp testbench_ez.vvp \
-		testbench_rvf.vvp testbench_wb.vvp testbench.vcd testbench.trace
+		testbench_rvf.vvp testbench_wb.vvp testbench.vcd testbench.trace \
+		testbench_verilator testbench_verilator_dir
 
 .PHONY: test test_vcd test_sp test_axi test_wb test_wb_vcd test_ez test_ez_vcd test_synth download-tools build-tools toc clean
diff --git a/testbench.v b/testbench.v
index 664bf02..b87ee36 100644
--- a/testbench.v
+++ b/testbench.v
@@ -275,30 +275,32 @@ module axi4_memory #(
 	parameter AXI_TEST = 0,
 	parameter VERBOSE = 0
 ) (
+	/* verilator lint_off MULTIDRIVEN */
+
 	input             clk,
 	input             mem_axi_awvalid,
-	output reg        mem_axi_awready = 0,
-	input [31:0]      mem_axi_awaddr,
-	input [ 2:0]      mem_axi_awprot,
+	output reg        mem_axi_awready,
+	input      [31:0] mem_axi_awaddr,
+	input      [ 2:0] mem_axi_awprot,
 
-	input            mem_axi_wvalid,
-	output reg       mem_axi_wready = 0,
-	input [31:0]     mem_axi_wdata,
-	input [ 3:0]     mem_axi_wstrb,
+	input             mem_axi_wvalid,
+	output reg        mem_axi_wready,
+	input      [31:0] mem_axi_wdata,
+	input      [ 3:0] mem_axi_wstrb,
 
-	output reg       mem_axi_bvalid = 0,
-	input            mem_axi_bready,
+	output reg        mem_axi_bvalid,
+	input             mem_axi_bready,
 
-	input            mem_axi_arvalid,
-	output reg       mem_axi_arready = 0,
-	input [31:0]     mem_axi_araddr,
-	input [ 2:0]     mem_axi_arprot,
+	input             mem_axi_arvalid,
+	output reg        mem_axi_arready,
+	input      [31:0] mem_axi_araddr,
+	input      [ 2:0] mem_axi_arprot,
 
-	output reg        mem_axi_rvalid = 0,
+	output reg        mem_axi_rvalid,
 	input             mem_axi_rready,
 	output reg [31:0] mem_axi_rdata,
 
-	output reg tests_passed
+	output reg        tests_passed
 );
 	reg [31:0]   memory [0:64*1024/4-1] /* verilator public */;
 	reg verbose;
@@ -307,7 +309,14 @@ module axi4_memory #(
 	reg axi_test;
 	initial axi_test = $test$plusargs("axi_test") || AXI_TEST;
 
-	initial tests_passed = 0;
+	initial begin
+		mem_axi_awready = 0;
+		mem_axi_wready = 0;
+		mem_axi_bvalid = 0;
+		mem_axi_arready = 0;
+		mem_axi_rvalid = 0;
+		tests_passed = 0;
+	end
 
 	reg [63:0] xorshift64_state = 64'd88172645463325252;