Fix build of core_dram_tb and dram_tb and fix tracing

We disabled --trace by default, so we need to stop linking verilated_vcd_c.o
as it doesn't exist in that case.

While at it, make a Makefile variable to enable/disable verilator tracing
and add a couple of generics to those test benches to control tracing
in the L2 and in litedram.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Makefile

@@ -2,7 +2,14 @@ GHDL ?= ghdl
 GHDLFLAGS=--std=08
 CFLAGS=-O3 -Wall
 # Need to investigate why yosys is hitting verilator warnings, and eventually turn on -Wall
-VERILATOR_FLAGS=-O3 -Wno-fatal -Wno-CASEOVERLAP -Wno-UNOPTFLAT #--trace
+VERILATOR_FLAGS=-O3 -Wno-fatal -Wno-CASEOVERLAP -Wno-UNOPTFLAT
+VERILATOR_TRACE=0
+
+ifeq ($(VERILATOR_TRACE),1)
+VERILATOR_FLAGS += --trace
+verilator_extra_link =  -Wl,obj_dir/verilated_vcd_c.o
+endif
+
 # It takes forever to build with optimisation, so disable by default
 #VERILATOR_CFLAGS=-O3
 
@@ -135,14 +142,14 @@ verilated_dram: litedram/generated/sim/litedram_core.v
 	make -C obj_dir -f ../litedram/extras/sim_dram_verilate.mk VERILATOR_ROOT=$(VERILATOR_ROOT)
 
 SIM_DRAM_CFLAGS  = -I. -Iobj_dir -Ilitedram/generated/sim -I$(VERILATOR_ROOT)/include -I$(VERILATOR_ROOT)/include/vltstd
-SIM_DRAM_CFLAGS += -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=1 -DVL_PRINTF=printf -faligned-new
+SIM_DRAM_CFLAGS += -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=$(VERILATOR_TRACE) -DVL_PRINTF=printf -faligned-new
 sim_litedram_c.o: litedram/extras/sim_litedram_c.cpp verilated_dram
 	$(CC)  $(CPPFLAGS) $(SIM_DRAM_CFLAGS) $(CFLAGS) -c $< -o $@
 
 soc_dram_files = $(core_files) $(soc_files) litedram/extras/litedram-wrapper-l2.vhdl litedram/generated/sim/litedram-initmem.vhdl
 soc_dram_sim_files = $(soc_sim_files) litedram/extras/sim_litedram.vhdl
 soc_dram_sim_obj_files = $(soc_sim_obj_files) sim_litedram_c.o
-dram_link_files=-Wl,obj_dir/Vlitedram_core__ALL.a -Wl,obj_dir/verilated.o -Wl,obj_dir/verilated_vcd_c.o -Wl,-lstdc++
+dram_link_files=-Wl,obj_dir/Vlitedram_core__ALL.a -Wl,obj_dir/verilated.o $(verilator_extra_link) -Wl,-lstdc++
 soc_dram_sim_link=$(patsubst %,-Wl$(comma)%,$(soc_dram_sim_obj_files)) $(dram_link_files)
 
 $(soc_dram_tbs): %: $(soc_dram_files) $(soc_dram_sim_files) $(soc_dram_sim_obj_files) $(flash_model_files) $(unisim_lib) $(fmf_lib) %.vhdl

core_dram_tb.vhdl

@@ -12,7 +12,9 @@ entity core_dram_tb is
         MEMORY_SIZE    : natural := (384*1024);
         MAIN_RAM_FILE  : string  := "main_ram.bin";
         DRAM_INIT_FILE : string  := "";
-        DRAM_INIT_SIZE : natural := 16#c000#
+        DRAM_INIT_SIZE : natural := 16#c000#;
+        L2_TRACE : boolean := false;
+        LITEDRAM_TRACE : boolean := false
         );
 end core_dram_tb;
 
@@ -124,7 +126,9 @@ begin
             DRAM_CKLINES => 1,
             DRAM_PORT_WIDTH => 128,
             PAYLOAD_FILE => DRAM_INIT_FILE,
-            PAYLOAD_SIZE => ROM_SIZE
+            PAYLOAD_SIZE => ROM_SIZE,
+            TRACE => L2_TRACE,
+            LITEDRAM_TRACE => LITEDRAM_TRACE
             )
         port map(
             clk_in          => clk,

dram_tb.vhdl

@@ -9,7 +9,9 @@ use work.wishbone_types.all;
 entity dram_tb is
     generic (
         DRAM_INIT_FILE : string  := "";
-        DRAM_INIT_SIZE : natural := 0
+        DRAM_INIT_SIZE : natural := 0;
+        L2_TRACE : boolean := false;
+        LITEDRAM_TRACE : boolean := false
         );
 end dram_tb;
 
@@ -47,7 +49,9 @@ begin
             DRAM_CKLINES => 1,
             DRAM_PORT_WIDTH => 128,
             PAYLOAD_FILE => DRAM_INIT_FILE,
-            PAYLOAD_SIZE => DRAM_INIT_SIZE
+            PAYLOAD_SIZE => DRAM_INIT_SIZE,
+            TRACE => L2_TRACE,
+            LITEDRAM_TRACE => LITEDRAM_TRACE
             )
         port map(
             clk_in              => clk_in,

litedram/extras/sim_litedram_c.cpp

@@ -102,6 +102,7 @@ static void do_eval(void)
 	if (tfp)
 		tfp->dump((double) main_time);
 #endif
+	main_time++;
 }
 
 extern "C" void litedram_set_wb(unsigned char *req)
@@ -184,10 +185,8 @@ extern "C" void litedram_clock(void)
 
 	v->clk = 1;
 	do_eval();
-	main_time++;
 	v->clk = 0;
 	do_eval();
-	main_time++;
 }
 
 extern "C" void litedram_init(int trace_on)