1 files changed, 136 insertions, 0 deletions
diff --git a/mk/verilator.mk b/mk/verilator.mk
new file mode 100644
index 0000000..0205e74
--- /dev/null
+++ b/mk/verilator.mk
@@ -0,0 +1,136 @@
+targets += sim
+
+vtop_dir = $(call per_target,vtop_dir)
+vtop_exe = $(call per_target,vtop_exe)
+
+vl_main = $(call per_target,vl_main)
+vl_flags = $(call per_target,vl_flags)
+vl_cflags = $(call per_target,vl_cflags)
+vl_ldflags = $(call per_target,vl_ldflags)
+
+define target/sim/prepare
+  enable_opt := 1
+
+  $(prepare_verilator_target)
+endef
+
+define target/sim/setup
+  $(setup_verilator_target)
+
+  $$(call target_var,vl_main) := $$(strip $$(call core_paths,$$(rule_top),vl_main))
+  ifeq (,$$(vl_main))
+    $$(error core '$$(rule_top)' does not define vl_main)
+  endif
+endef
+
+define target/sim/rules
+  $(verilator_target_rules)
+
+  .PHONY: $$(rule_top_path)/sim
+
+  $$(rule_top_path)/sim: $$(vtop_exe)
+	$$<
+endef
+
+define prepare_verilator_target
+  flow/type := sim
+endef
+
+define setup_verilator_target
+  $(call build_vars,$(addprefix enable_,rand threads trace cov opt lto))
+
+  $(call target_var,vl_flags) = $(common_vl_flags)
+  $(call target_var,vl_cflags) = $(common_vl_cflags)
+  $(call target_var,vl_ldflags) = $(common_vl_ldflags)
+endef
+
+$(eval $(call defer,common_vl_flags,$$(set_verilator_common)))
+$(eval $(call defer,common_vl_cflags,$$(set_verilator_common)))
+$(eval $(call defer,common_vl_ldflags,$$(set_verilator_common)))
+
+define set_verilator_common
+  ifneq (,$$(enable_lto))
+    enable_opt := 1
+  endif
+
+  x_mode := $$(if $$(enable_rand),unique,fast)
+
+  static_flags := \
+    --x-assign $$(x_mode) --x-initial $$(x_mode) \
+    $$(if $$(enable_threads),--threads $$(call shell_checked,nproc)) \
+    $$(if $$(enable_trace),--trace --trace-fst --trace-structs) \
+    $$(if $$(enable_cov),--coverage) \
+    $$(if $$(enable_opt),-O3) \
+    --cc --exe --prefix Vtop --MMD --MP
+
+  common_vl_flags := $$(static_flags) $$(core_info/$$(rule_top)/vl_flags)
+
+  common_vl_cflags := \
+    $$(if $$(enable_opt),-O3) \
+    $$(if $$(enable_lto),-flto)
+
+  common_vl_ldflags := \
+    $$(if $$(enable_lto),-flto)
+endef
+
+define verilator_target_rules
+  $(call target_var,vtop_dir) := $$(obj)/vl
+  $(call target_var,vtop_exe) := $$(vtop_dir)/Vtop
+
+  vtop_mk_file := $$(vtop_dir)/Vtop.mk
+  vtop_mk_stamp := $$(vtop_dir)/stamp
+  vtop_dep_file := $$(vtop_dir)/Vtop__ver.d
+
+  -include $$(vtop_dep_file)
+  $$(vtop_dep_file):
+
+  $$(vtop_exe): export VPATH := $$(src)
+  $$(vtop_exe): $$(vtop_mk_stamp)
+	$$(call run_submake,BUILD) $$(if $$(V),,-s) -C $$(vtop_dir) -f Vtop.mk
+	@touch -c $$@
+
+  $$(vtop_mk_file):
+	@rm -f $$@
+
+  $$(vtop_mk_stamp): $$(top_stamp) $$(vtop_mk_file)
+	$$(eval $$(final_vflags))
+	$$(call run,VERILATE) $$(VERILATOR) $$(vl_flags) $$(verilator_src_args)
+	@touch $$@
+
+  $(call target_entrypoint,$$(vtop_exe))
+endef
+
+define final_vflags
+  $(call find_with_pkgconfig, \
+    $(call map_core_deps,vl_pkgconfig,$(rule_top)), \
+    $(call target_var,vl_cflags), \
+    $(call target_var,vl_ldflags))
+
+  $$(call target_var,vl_flags) += --Mdir $$(vtop_dir)
+  $$(call target_var,vl_cflags) := $$(strip $$(vl_cflags))
+  $$(call target_var,vl_ldflags) := $$(strip $$(vl_ldflags))
+
+  # Verilator's wrapper script can't handle `-CFLAGS ''` correctly
+  ifneq (,$$(vl_cflags))
+    $$(call target_var,vl_flags) += -CFLAGS '$$(vl_cflags)'
+  endif
+
+  ifneq (,$$(vl_ldflags))
+    $$(call target_var,vl_flags) += -LDFLAGS '$$(vl_ldflags)'
+  endif
+endef
+
+verilator_src_args = \
+  $(strip \
+    $(let rtl_top,$(core_info/$(rule_top)/rtl_top), \
+      $(if $(rtl_top),--top $(rtl_top),$(error core '$(rule_top)' must define rtl_top)) \
+      $(foreach dep,$(dep_tree/$(rule_top)), \
+        $(let prefix,$(core_info/$(dep)/workdir)/, \
+          $(foreach rtl_dir,$(call core_paths,$(dep),rtl_dirs), \
+            -y $(rtl_dir)) \
+          $(foreach include_dir,$(call core_paths,$(dep),rtl_include_dirs), \
+            -I$(include_dir)) \
+          $(foreach src_file,$(call core_paths,$(dep),rtl_files) $(call core_paths,$(dep),vl_files), \
+            $(src_file)))) \
+      $(if $(core_info/$(rule_top)/rtl_files),,$(rtl_top))) \
+    $(if $(vl_main),$(vl_main),$(error $$(vl_main) not defined by target '$(rule_target)')))