diff --git a/passes/cmds/Makefile.inc b/passes/cmds/Makefile.inc
index f4c4db2f8..cb267e369 100644
--- a/passes/cmds/Makefile.inc
+++ b/passes/cmds/Makefile.inc
@@ -58,3 +58,4 @@ OBJS += passes/cmds/test_select.o
 OBJS += passes/cmds/timeest.o
 OBJS += passes/cmds/linecoverage.o
 OBJS += passes/cmds/publish.o
+OBJS += passes/cmds/icell_liberty.o
diff --git a/passes/cmds/icell_liberty.cc b/passes/cmds/icell_liberty.cc
new file mode 100644
index 000000000..19692fa01
--- /dev/null
+++ b/passes/cmds/icell_liberty.cc
@@ -0,0 +1,138 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2024  Martin Povišer <povik@cutebit.org>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+#include "kernel/yosys.h"
+#include "kernel/celltypes.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct LibertyStubber {
+	CellTypes ct;
+	CellTypes ct_ff;
+	LibertyStubber() {
+		ct.setup();
+		ct.setup_internals_ff();
+	}
+	void liberty_prefix(std::ostream& f)
+	{
+		f << "library (yosys) {\n";
+		f << "\tinput_threshold_pct_fall : 50;\n";
+		f << "\tinput_threshold_pct_rise : 50;\n";
+		f << "\toutput_threshold_pct_fall : 50;\n";
+		f << "\toutput_threshold_pct_rise : 50;\n";
+		f << "\tslew_lower_threshold_pct_fall : 1;\n";
+		f << "\tslew_lower_threshold_pct_rise : 1;\n";
+		f << "\tslew_upper_threshold_pct_fall : 99;\n";
+		f << "\tslew_upper_threshold_pct_rise : 99;\n";
+	}
+	void liberty_suffix(std::ostream& f)
+	{
+		f << "}\n";
+	}
+	void liberty_cell(Module* base, Module* derived, std::ostream& f)
+	{
+		auto base_name = base->name.str().substr(1);
+		auto derived_name = derived->name.str().substr(1);
+		if (!ct.cell_types.count(base_name)) {
+			log_debug("skip skeleton for %s\n", base_name.c_str());
+			return;
+		}
+		auto& base_type = ct.cell_types[base_name];
+		f << "\tcell (\"" << derived_name << "\") {\n";
+		for (auto x : derived->ports) {
+			bool is_input = base_type.inputs.count(x);
+			bool is_output = base_type.outputs.count(x);
+			f << "\t\tpin (" << RTLIL::unescape_id(x.str()) << ") {\n";
+			if (is_input && !is_output) {
+				f << "\t\t\tdirection : input;\n";
+			} else if (!is_input && is_output) {
+				f << "\t\t\tdirection : output;\n";
+			} else {
+				f << "\t\t\tdirection : inout;\n";
+			}
+			f << "\t\t}\n";
+		}
+		f << "\t}\n";
+	}
+};
+
+struct IcellLiberty : Pass {
+	IcellLiberty() : Pass("icell_liberty", "derive box modules") {}
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    icell_liberty <liberty_file>\n"); // TODO
+		log("\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *d) override
+	{
+		log_header(d, "Executing ICELL_LIBERTY pass.\n");
+
+		size_t argidx;
+		IdString naming_attr;
+		std::string liberty_filename;
+		std::ofstream* liberty_file = new std::ofstream;
+
+		for (argidx = 1; argidx < args.size(); argidx++) {
+			break;
+		}
+		if (argidx < args.size())
+			liberty_filename = args[argidx++];
+		else
+			log_error("no Liberty filename specified\n");
+
+		// extra_args(args, argidx, d);
+
+		if (liberty_filename.size()) {
+			liberty_file->open(liberty_filename.c_str());
+			if (liberty_file->fail()) {
+				delete liberty_file;
+				log_error("Can't open file `%s' for writing: %s\n", liberty_filename.c_str(), strerror(errno));
+			}
+		}
+
+		pool<RTLIL::IdString> done;
+		LibertyStubber stubber = {};
+
+		if (liberty_file)
+			stubber.liberty_prefix(*liberty_file);
+
+		for (auto module : d->selected_modules()) {
+			for (auto cell : module->selected_cells()) {
+				Module *inst_module = d->module(cell->type);
+				if (!inst_module || !inst_module->get_blackbox_attribute())
+					continue;
+				Module *base = inst_module;
+				if (!done.count(base->name)) {
+					stubber.liberty_cell(base, base, *liberty_file);
+					done.insert(base->name);
+				}
+			}
+		}
+
+		if (liberty_file) {
+			stubber.liberty_suffix(*liberty_file);
+			delete liberty_file;
+		}
+	}
+} IcellLiberty;
+
+PRIVATE_NAMESPACE_END