Added support for additional Verilator modes

[sifferman]

Hello! I was having troubles getting Verilator XML dumps working with the existing Edalize version, so I added it as a verilator->mode option.

I'm not sure if better documentation should be provided for it, but I didn't want to be too verbose

Thanks!

[sifferman]

Actually, now that I think about it, I should probably just add all the remaining modes:

Existing:

• --cc
• --sc
• --lint-only

New:

• --binary
• --dpi-hdr-only
• --xml-only
• -E

[sifferman]

Should be all ready for review!

This adds the following modes:

binary (--binary)
dpi-hdr-only (--dpi-hdr-only)
preprocess-only (-E)
xml-only (--xml-only)

I also removed --exe from the .vc file when in the modes "binary", "dpi-hdr-only", "lint-only", "preprocess-only", or "xml-only".

[sifferman]

Actually, I just had a new idea for 3 additional Verilator fields:

• gen-xml: <bool>
• gen-dpi-hdr: <bool>
• xml-output: <filename : String>

This way, using the same run command on a single target, we could generate an XML file, and a DPI.h file.

If gen-xml was enabled, verilator could just be run once more, except with the option --xml-only. If gen-dpi-hdr was enabled, verilator could just be run once more, except with the option --dpi-hdr-only.

This could even potentially replace the dpi-hdr-only and xml-only modes. -E only prints to stdout, so I don't think this deserves its own field.

[olofk]

I think this is great, but let's just think it through. As you say, there are different ways to accomplish this, so let's find something that has a good balance between complexity and user friendliness. I haven't really dug into this part of Verilator. Are all these modes mutually exclusive, or could some modes just be added as verilator_options instead?

[sifferman]

At least one of the following flags must be set [ref], and the documentation implies them to be mutually exclusive [ref]:

--binary, --cc, --sc, --dpi-hdr-only, --lint-only, --xml-only, -E

Selecting more than one leads to unexpected behavior.

Example

core snippet

      verilator:
        verilator_options:
          - --xml-only

error

make[1]: Vtop.mk: No such file or directory
make[1]: *** No rule to make target 'Vtop.mk'.  Stop.

fixed core snippet

      verilator:
        mode: lint-only
        verilator_options:
          - --xml-only

With FuseSoC, to get XML output, you must specify verilator_options: --xml-only and mode: lint-only, which seems weird. Plus there is no current way to get DPI header output because --lint-only overwrites --dpi-hdr-only, and --dpi-hdr-only + --cc/--sc is not allowed.

Therefore, I feel like creating a mode for each makes a lot of sense.

[sifferman]

Small update:

Wilson just merged my pull request that explicitly enforces the flags (--build, -E, --dpi-hdr-only, --lint-only, --xml-only) to be mutually exclusive (verilator/verilator#4409)

Now the --xml-only example I gave no longer works:

      verilator:
        mode: lint-only
        verilator_options:
          - --xml-only

due to

%Error: The following cannot be used together: --lint-only, --xml-only. Suggest see manual

[sifferman]

Alright, @olofk. How does this look?

I expanded the Verilator Makefile to include the modes as callable Makefile targets:

edalize/edalize/verilator.py

Lines 37 to 47 in 2e30ad1

	.PHONY: binary dpi-hdr-only lint-only preprocess-only xml-only
	binary:
	$(EDALIZE_LAUNCHER) $(VERILATOR) --binary -f $(VC_FILE) $(VERILATOR_OPTIONS)
	dpi-hdr-only:
	$(EDALIZE_LAUNCHER) $(VERILATOR) --dpi-hdr-only -f $(VC_FILE) $(VERILATOR_OPTIONS)
	lint-only:
	$(EDALIZE_LAUNCHER) $(VERILATOR) --lint-only -f $(VC_FILE) $(VERILATOR_OPTIONS)
	preprocess-only V$(TOP_MODULE).i:
	$(EDALIZE_LAUNCHER) $(VERILATOR) -E -f $(VC_FILE) $(VERILATOR_OPTIONS) > V$(TOP_MODULE).i
	xml-only V$(TOP_MODULE).xml:
	$(EDALIZE_LAUNCHER) $(VERILATOR) --xml-only -f $(VC_FILE) $(VERILATOR_OPTIONS)

I also added the following fields gen-xml, gen-dpi-hdr, gen-preprocess, and have them run the corresponding Makefile targets after the usual building due to the specified mode.

edalize/edalize/verilator.py

Lines 78 to 92 in 2e30ad1

	{
	"name": "gen-xml",
	"type": "bool",
	"desc": "Generate XML output",
	},
	{
	"name": "gen-dpi-hdr",
	"type": "bool",
	"desc": "Generate DPI header output",
	},
	{
	"name": "gen-preprocess",
	"type": "bool",
	"desc": "Generate preprocessor output",
	},

edalize/edalize/verilator.py

Lines 251 to 257 in 2e30ad1

	# Additional builds
	if str(self.tool_options.get("gen-xml")).lower() == "true":
	self._run_tool("make", ["xml-only"], quiet=True)
	if str(self.tool_options.get("gen-dpi-hdr")).lower() == "true":
	self._run_tool("make", ["dpi-hdr-only"], quiet=True)
	if str(self.tool_options.get("gen-preprocess")).lower() == "true":
	self._run_tool("make", ["preprocess-only"], quiet=True)

I also added an additional mode "none" which when specified, will only do the additional builds specified with gen-xml, gen-dpi-hdr, gen-preprocess

edalize/edalize/verilator.py

Lines 247 to 249 in 2e30ad1

	# Build mode
	if self.tool_options["mode"] != "none":
	self._run_tool("make", args, quiet=True)

[olofk]

Took me a while longer than planned to get back to this, but I think it looks all fine now. Thank you for your contributions. Picked and pushed!

[sifferman]

Thanks, @olofk!