diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..aea016c
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,32 @@
+[submodule "prjxray"]
+        path = prjxray
+	url = ../prjxray
+        branch = .
+[submodule "prjtrellis"]
+        path = prjtrellis
+	url = ../prjtrellis
+        branch = .
+[submodule "third_party/icestorm"]
+        path = third_party/icestorm
+	url = ../third_party/icestorm
+        branch = .
+[submodule "third_party/nextpnr"]
+        path = third_party/nextpnr
+	url = ../third_party/nextpnr
+        branch = .
+[submodule "third_party/Surelog"]
+        path = third_party/Surelog
+	url = ../third_party/Surelog
+        branch = .
+[submodule "third_party/verible"]
+        path = third_party/verible
+	url = ../third_party/verible
+        branch = .
+[submodule "third_party/vtr-verilog-to-routing"]
+        path = third_party/vtr-verilog-to-routing
+	url = ../third_party/vtr-verilog-to-routing
+        branch = .
+[submodule "third_party/yosys"]
+        path = third_party/yosys
+	url = ../third_party/yosys
+        branch = .