From de37070c28c08e1d7a5e18f8c65e4837f51c9e40 Mon Sep 17 00:00:00 2001
From: Gus Smith <guscomps@gmail.com>
Date: Wed, 22 Jun 2022 10:57:46 -0700
Subject: [PATCH] Support param. default values in JSON FE and SV BE

---
 backends/verilog/verilog_backend.cc | 11 +++++++++++
 frontends/json/jsonparse.cc         |  3 +++
 2 files changed, 14 insertions(+)

diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc
index aa1d4558c..28cbb4f4d 100644
--- a/backends/verilog/verilog_backend.cc
+++ b/backends/verilog/verilog_backend.cc
@@ -395,6 +395,14 @@ void dump_attributes(std::ostream &f, std::string indent, dict<RTLIL::IdString,
 	}
 }
 
+void dump_parameter(std::ostream &f, std::string indent, RTLIL::IdString id_string, RTLIL::Const parameter)
+{
+	f << stringf("%sparameter %s", indent.c_str(), id(id_string).c_str());
+	f << stringf(" = ");
+	dump_const(f, parameter);
+	f << stringf(";\n");
+}
+
 void dump_wire(std::ostream &f, std::string indent, RTLIL::Wire *wire)
 {
 	dump_attributes(f, indent, wire->attributes, '\n', /*modattr=*/false, /*regattr=*/reg_wires.count(wire->name));
@@ -2084,6 +2092,9 @@ void dump_module(std::ostream &f, std::string indent, RTLIL::Module *module)
 		f << indent + "  " << "reg " << id(initial_id) << " = 0;\n";
 	}
 
+	for (auto p : module->parameter_default_values)
+		dump_parameter(f, indent + "  ", p.first, p.second);
+
 	for (auto w : module->wires())
 		dump_wire(f, indent + "  ", w);
 
diff --git a/frontends/json/jsonparse.cc b/frontends/json/jsonparse.cc
index 1aab81015..96c2d3d77 100644
--- a/frontends/json/jsonparse.cc
+++ b/frontends/json/jsonparse.cc
@@ -302,6 +302,9 @@ void json_import(Design *design, string &modname, JsonNode *node)
 	if (node->data_dict.count("attributes"))
 		json_parse_attr_param(module->attributes, node->data_dict.at("attributes"));
 
+	if (node->data_dict.count("parameter_default_values"))
+		json_parse_attr_param(module->parameter_default_values, node->data_dict.at("parameter_default_values"));
+
 	dict<int, SigBit> signal_bits;
 
 	if (node->data_dict.count("ports"))