Verilator: Enable passing arguments to the make

The verilator-generated Makefiles use documented variables to configure
the build process. The most important ones are OPT/OPT_FAST/OPT_SLOW to
influence the compiler flags for the individual parts of the build.

With verilator_options, one can already set compiler options globally
(such as "-O2"). However, compiling larger designs with such high
optimization settings leads to long build times with no real benefit,
especially if tracing is enabled. In those cases, setting OPT_FAST="-O2"
and not setting any global optimization flags can cut down the build
time by multiple times.

edalize/verilator.py

@@ -11,6 +11,7 @@
 TOP_MODULE        := {top_module}
 VC_FILE           := {vc_file}
 VERILATOR_OPTIONS := {verilator_options}
+MAKE_OPTIONS      := {make_options}
 """
 
 MAKEFILE_TEMPLATE = """#Auto generated by Edalize
@@ -25,7 +26,7 @@
 endif
 
 V$(TOP_MODULE): V$(TOP_MODULE).mk
-	$(MAKE) -f $<
+	$(MAKE) $(MAKE_OPTIONS) -f $<
 
 V$(TOP_MODULE).mk:
 	$(VERILATOR) -f $(VC_FILE) $(VERILATOR_OPTIONS)
@@ -37,7 +38,8 @@ class Verilator(Edatool):
     tool_options = {'members' : {'mode' : 'String',
                                  'cli_parser' : 'String'},
                     'lists'   : {'libs' : 'String',
-                                 'verilator_options' : 'String'}}
+                                 'verilator_options' : 'String'},
+                                 'make_options': 'String'}
 
     argtypes = ['cmdlinearg', 'plusarg', 'vlogdefine', 'vlogparam']
 
@@ -59,6 +61,9 @@ def get_doc(cls, api_ver):
                         {'name' : 'verilator_options',
                          'type' : 'String',
                          'desc' : 'Additional options for verilator'},
+                        {'name' : 'make_options',
+                         'type' : 'String',
+                         'desc' : 'Additional arguments passed to make when compiling the simulation. This is commonly used to set OPT/OPT_FAST/OPT_SLOW.'},
                         ]}
 
     def _managed_parser(self):
@@ -125,11 +130,18 @@ def _write_config_files(self):
             verilator_options = ' '.join(self.tool_options['verilator_options'])
         else:
             verilator_options = ''
+
+        if 'make_options' in self.tool_options:
+            make_options = ' '.join(self.tool_options['make_options'])
+        else:
+            make_options = ''
+
         with open(os.path.join(self.work_root, 'config.mk'), 'w') as config_mk:
             config_mk.write(CONFIG_MK_TEMPLATE.format(
                 top_module        = self.toplevel,
                 vc_file           = self.verilator_file,
-                verilator_options = verilator_options))
+                verilator_options = verilator_options,
+                make_options      = make_options))
 
     def build_main(self):
         logger.info("Building simulation model")

tests/test_verilator/Makefile

@@ -10,7 +10,7 @@ VERILATOR ?= $(VERILATOR_ROOT)/bin/verilator
 endif
 
 V$(TOP_MODULE): V$(TOP_MODULE).mk
-	$(MAKE) -f $<
+	$(MAKE) $(MAKE_OPTIONS) -f $<
 
 V$(TOP_MODULE).mk:
 	$(VERILATOR) -f $(VC_FILE) $(VERILATOR_OPTIONS)

tests/test_verilator/cc/config.mk

@@ -3,3 +3,4 @@
 TOP_MODULE        := orpsoc_top
 VC_FILE           := mor1kx-generic_0.vc
 VERILATOR_OPTIONS := -Wno-fatal --trace
+MAKE_OPTIONS      := OPT_FAST=-O2

tests/test_verilator/cc/mor1kx-generic_0.eda.yml

@@ -116,6 +116,7 @@ tool_options:
     mode: cc
     top_module: orpsoc_top
     verilator_options: [-Wno-fatal, --trace]
+    make_options: ['OPT_FAST=-O2']
 toplevel: orpsoc_top
 version: 0.1.1
 vpi:

tests/test_verilator/lint-only/config.mk

@@ -3,3 +3,4 @@
 TOP_MODULE        := orpsoc_top
 VC_FILE           := mor1kx-generic_0.vc
 VERILATOR_OPTIONS := 
+MAKE_OPTIONS      := 

tests/test_verilator/sc/config.mk

@@ -3,3 +3,4 @@
 TOP_MODULE        := orpsoc_top
 VC_FILE           := mor1kx-generic_0.vc
 VERILATOR_OPTIONS := 
+MAKE_OPTIONS      :=