Adding columbus project as submodule
diff --git a/.gitmodules b/.gitmodules
index c73b442..d660bde 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
[submodule "caravel-lite"]
path = caravel
url = https://github.com/efabless/caravel-lite
+[submodule "columbus"]
+ path = columbus
+ url = https://gitlab.com/skywater130/columbus.git
diff --git a/columbus b/columbus
new file mode 160000
index 0000000..7771593
--- /dev/null
+++ b/columbus
@@ -0,0 +1 @@
+Subproject commit 77715938ac822cdc2917213fefa6fbed6d4a0aea