diff --git a/techlibs/common/Makefile.inc b/techlibs/common/Makefile.inc
index e76d70a1a..1ae2c7ce8 100644
--- a/techlibs/common/Makefile.inc
+++ b/techlibs/common/Makefile.inc
@@ -2,6 +2,8 @@
 ifneq ($(SMALL),1)
 OBJS += techlibs/common/synth.o
 OBJS += techlibs/common/prep.o
+OBJS += techlibs/common/opensta.o
+OBJS += techlibs/common/sdc_expand.o
 endif
 
 GENFILES += techlibs/common/simlib_help.inc
diff --git a/techlibs/common/opensta.cc b/techlibs/common/opensta.cc
new file mode 100644
index 000000000..1b3571973
--- /dev/null
+++ b/techlibs/common/opensta.cc
@@ -0,0 +1,118 @@
+#include "kernel/rtlil.h"
+#include "kernel/log.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+#if !defined(YOSYS_DISABLE_SPAWN)
+struct OpenstaPass : public Pass
+{
+	const char* default_sta_cmd = "sta";
+	OpenstaPass() : Pass("opensta", "run OpenSTA") { }
+
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    opensta [options]\n");
+		log("\n");
+		// TOOD
+		log("\n");
+		log("    -exe <command>\n");
+		log("        use <command> to run OpenSTA instead of \"%s\"\n", default_sta_cmd);
+		log("\n");
+		log("    -sdc-in <filename>\n");
+		log("        expand SDC input file <filename>\n");
+		log("\n");
+		log("    -sdc-out <filename>\n");
+		log("        expand SDC file to output file <filename>\n");
+		log("\n");
+		log("    -nocleanup\n");
+		log("\n");
+		log("\n");
+	}
+
+	void execute(std::vector<std::string> args, RTLIL::Design *design) override
+	{
+		string run_from, run_to;
+		string opensta_exe = "sta";
+		string sdc_filename, sdc_expanded_filename;
+		string tempdir_name, script_filename;
+		string verilog_filename, liberty_filename;
+		bool cleanup = true;
+
+		log_header(design, "Executing OPENSTA pass.\n");
+		log_push();
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			if (args[argidx] == "-exe" && argidx+1 < args.size()) {
+				opensta_exe = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-sdc-in" && argidx+1 < args.size()) {
+				sdc_filename = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-sdc-out" && argidx+1 < args.size()) {
+				sdc_expanded_filename = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-verilog" && argidx+1 < args.size()) {
+				verilog_filename = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-liberty" && argidx+1 < args.size()) {
+				liberty_filename = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-nocleanup") {
+				cleanup = false;
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+		if (!design->full_selection())
+			log_cmd_error("This command only operates on fully selected designs!\n");
+
+		if (cleanup)
+			tempdir_name = get_base_tmpdir() + "/";
+		else
+			tempdir_name = "_tmp_";
+		tempdir_name += proc_program_prefix() + "yosys-opensta-XXXXXX";
+		tempdir_name = make_temp_dir(tempdir_name);
+		script_filename = tempdir_name + "/opensta.tcl";
+		// script_filename
+
+		auto top_mod = design->top_module();
+		if (!top_mod)
+			log_error("Can't find top module in current design!\n");
+
+		std::ofstream f_script;
+		f_script.open(script_filename);
+
+		f_script << "read_verilog " << verilog_filename << "\n";
+		f_script << "read_lib " << liberty_filename << "\n";
+		f_script << "link_design " << RTLIL::unescape_id(top_mod->name) << "\n";
+		f_script << "read_sdc " << sdc_filename << "\n";
+		f_script << "write_sdc " << sdc_expanded_filename << "\n";
+		f_script.close();
+		std::string command = opensta_exe + " -exit " + script_filename; 
+		int ret = run_command(command);
+		if (ret)
+			log_error("OpenSTA return %d (error)\n", ret);
+		else
+			log("sdc_expanded_filename: %s\n", sdc_expanded_filename.c_str());
+
+		if (cleanup) {
+			log("Removing temp directory.\n");
+			remove_directory(tempdir_name);
+		}
+		log_pop();
+	}
+} OpenstaPass;
+#endif
+
+PRIVATE_NAMESPACE_END
diff --git a/techlibs/common/sdc_expand.cc b/techlibs/common/sdc_expand.cc
new file mode 100644
index 000000000..1dcc8b9fa
--- /dev/null
+++ b/techlibs/common/sdc_expand.cc
@@ -0,0 +1,150 @@
+#include "kernel/rtlil.h"
+#include "kernel/log.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct SdcexpandPass : public ScriptPass
+{
+	const char* default_sta_cmd = "sta";
+	SdcexpandPass() : ScriptPass("sdc_expand", "run OpenSTA") { }
+
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    sdc_expand [options]\n");
+		log("\n");
+		// TODO
+		log("\n");
+		log("    -exe <command>\n");
+		log("        use <command> to run OpenSTA instead of \"%s\"\n", default_sta_cmd);
+		log("\n");
+		log("    -sdc-in <filename>\n");
+		log("        expand SDC file <filename>\n");
+		log("\n");
+		log("    -nocleanup\n");
+		log("\n");
+		log("\n");
+		log("The following commands are executed by this synthesis command:\n");
+		help_script();
+		log("\n");
+	}
+
+	string opensta_exe, sdc_filename, sdc_expanded_filename;
+	bool cleanup;
+	void execute(std::vector<std::string> args, RTLIL::Design *design) override
+	{
+		string run_from, run_to;
+		cleanup = true;
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			if (args[argidx] == "-exe" && argidx+1 < args.size()) {
+				opensta_exe = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-sdc-in" && argidx+1 < args.size()) {
+				sdc_filename = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-sdc-out" && argidx+1 < args.size()) {
+				sdc_expanded_filename = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-nocleanup") {
+				cleanup = false;
+				continue;
+			}
+			// repetitive boring bit
+			if (args[argidx] == "-run" && argidx+1 < args.size()) {
+				size_t pos = args[argidx+1].find(':');
+				if (pos == std::string::npos) {
+					run_from = args[++argidx];
+					run_to = args[argidx];
+				} else {
+					run_from = args[++argidx].substr(0, pos);
+					run_to = args[argidx].substr(pos+1);
+				}
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		if (!design->full_selection())
+			log_cmd_error("This command only operates on fully selected designs!\n");
+
+		log_header(design, "Executing OPENSTA pass.\n");
+		log_push();
+
+		run_script(design, run_from, run_to);
+
+		log_pop();
+	}
+
+	void script() override
+	{
+		std::string tempdir_name;
+		std::string liberty_path;
+		std::string verilog_path;
+
+		run("design -save pre_expand");
+		run("proc");
+		run("memory");
+		// run("dfflegalize -cell $dff");
+
+		std::string write_verilog_cmd = "write_verilog -norename -noexpr -attr2comment -defparam ";
+		if (help_mode) {
+			run(write_verilog_cmd + "<tmp_dir>/elaborated.v");
+		} else {
+			if (cleanup)
+				tempdir_name = get_base_tmpdir() + "/";
+			else
+				tempdir_name = "_tmp_";
+			tempdir_name += proc_program_prefix() + "yosys-sdc_expand-XXXXXX";
+			tempdir_name = make_temp_dir(tempdir_name);
+			verilog_path = tempdir_name + "/elaborated.v";
+			run(write_verilog_cmd + verilog_path);
+		}
+
+		run("read_verilog -setattr whitebox -defer -DSIMLIB_NOCHECKS +/simlib.v");
+		run("proc");
+		run("hierarchy -auto-top");
+		run("publish");
+
+		if (help_mode) {
+			run("icell_liberty <tmp_dir>/yosys.lib");
+		} else {
+			liberty_path = tempdir_name + "/yosys.lib";
+			run(stringf("icell_liberty %s", liberty_path.c_str()));
+		}
+
+		std::string opensta_pass_call = "opensta -exe ";
+		opensta_pass_call += help_mode ? "<exe>" : opensta_exe;
+		opensta_pass_call += " -sdc-in ";
+		opensta_pass_call += help_mode ? "<sdc-in>" : sdc_filename;
+		opensta_pass_call += " -sdc-out ";
+		opensta_pass_call += help_mode ? "<sdc-out>" : sdc_expanded_filename;
+		opensta_pass_call += " -verilog ";
+		opensta_pass_call += help_mode ? "<verilog>" : verilog_path;
+		opensta_pass_call += " -liberty ";
+		opensta_pass_call += help_mode ? "<tmp_dir>/yosys.lib" : liberty_path;
+		if (!cleanup)
+			opensta_pass_call += " -nocleanup";
+		run(opensta_pass_call.c_str());
+
+		if (!help_mode) {
+			if (cleanup) {
+				log("Removing temp directory.\n");
+				remove_directory(tempdir_name);
+			} else {
+				log("Keeping temp directory %s\n", tempdir_name.c_str());
+			}
+		}
+		run("design -load pre_expand");
+	}
+} SdcexpandPass;
+
+PRIVATE_NAMESPACE_END