diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..6e06e69
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "pico-hsm-sdk"]
+	path = pico-hsm-sdk
+	url = ../pico-hsm-sdk
diff --git a/pico-hsm-sdk b/pico-hsm-sdk
new file mode 160000
index 0000000..1d2a461
--- /dev/null
+++ b/pico-hsm-sdk
@@ -0,0 +1 @@
+Subproject commit 1d2a461086526b5f8a0ba08fe111aea10e87f12a