diff --git a/CMakeLists.txt b/CMakeLists.txt
index f395e78..cbce239 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -155,7 +155,7 @@ endif()
 # Import definitions of all libraries
 #
 
-# add_subdirectory(lib)
+add_subdirectory(lib)
 
 #
 # MMU firmware
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
new file mode 100644
index 0000000..09159f6
--- /dev/null
+++ b/lib/CMakeLists.txt
@@ -0,0 +1,3 @@
+if(NOT CMAKE_CROSSCOMPILING)
+  add_subdirectory(Catch2)
+endif()
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 792d600..269aea0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1 +1 @@
-#
+add_subdirectory(unit)
diff --git a/tests/unit/CMakeLists.txt b/tests/unit/CMakeLists.txt
index 792d600..bc08872 100644
--- a/tests/unit/CMakeLists.txt
+++ b/tests/unit/CMakeLists.txt
@@ -1 +1,28 @@
-#
+# first, let's create a symbolic target for all tests
+add_custom_target(tests)
+
+# this had a reason on the Buddy FW, but on the AVR we cannot get close to having 16bit ints and
+# pointers so the unit tests may be compiled 64bit afterall
+set(CMAKE_C_FLAGS -m32)
+set(CMAKE_CXX_FLAGS -m32)
+
+# include catch_discover_tests function from Catch2
+include(${Catch2_SOURCE_DIR}/contrib/Catch.cmake)
+
+add_library(catch_main ${CMAKE_CURRENT_SOURCE_DIR}/test_main.cpp)
+target_link_libraries(catch_main Catch2::Catch2)
+
+# registers given target as a catch test
+function(add_catch_test target)
+  target_link_libraries(${target} catch_main Catch2::Catch2)
+  catch_discover_tests(${target})
+  add_dependencies(tests ${target})
+endfunction()
+
+add_executable(system_tests ${CMAKE_CURRENT_SOURCE_DIR}/system_test.cpp)
+add_catch_test(system_tests)
+
+# now, include all the unit tests; they should add themselves using the add_catch_test function
+add_subdirectory(hal)
+add_subdirectory(logic)
+add_subdirectory(modules)
diff --git a/tests/unit/hal/CMakeLists.txt b/tests/unit/hal/CMakeLists.txt
new file mode 100644
index 0000000..792d600
--- /dev/null
+++ b/tests/unit/hal/CMakeLists.txt
@@ -0,0 +1 @@
+#
diff --git a/tests/unit/logic/CMakeLists.txt b/tests/unit/logic/CMakeLists.txt
new file mode 100644
index 0000000..792d600
--- /dev/null
+++ b/tests/unit/logic/CMakeLists.txt
@@ -0,0 +1 @@
+#
diff --git a/tests/unit/modules/CMakeLists.txt b/tests/unit/modules/CMakeLists.txt
new file mode 100644
index 0000000..be359f4
--- /dev/null
+++ b/tests/unit/modules/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(protocol)
diff --git a/tests/unit/modules/protocol/CMakeLists.txt b/tests/unit/modules/protocol/CMakeLists.txt
new file mode 100644
index 0000000..fbaaf53
--- /dev/null
+++ b/tests/unit/modules/protocol/CMakeLists.txt
@@ -0,0 +1,8 @@
+# define the test executable
+add_executable(protocol_tests test_protocol.cpp)
+
+# define required search paths
+target_include_directories(protocol_tests PUBLIC ${CMAKE_SOURCE_DIR}/src/modules)
+
+# tell build system about the test case
+add_catch_test(protocol_tests)
diff --git a/tests/unit/modules/protocol/test_protocol.cpp b/tests/unit/modules/protocol/test_protocol.cpp
new file mode 100644
index 0000000..df686bd
--- /dev/null
+++ b/tests/unit/modules/protocol/test_protocol.cpp
@@ -0,0 +1,8 @@
+#include "catch2/catch.hpp"
+#include "protocol.h"
+
+using Catch::Matchers::Equals;
+
+TEST_CASE("protocol::1", "[protocol]") {
+    CHECK(true);
+}
diff --git a/tests/unit/system_test.cpp b/tests/unit/system_test.cpp
new file mode 100644
index 0000000..a14875a
--- /dev/null
+++ b/tests/unit/system_test.cpp
@@ -0,0 +1,6 @@
+#include "catch2/catch.hpp"
+
+TEST_CASE("type tests", "[system]") {
+    REQUIRE(sizeof(uint64_t) == 8);
+    REQUIRE(sizeof(char *) == 4);
+}
diff --git a/tests/unit/test_main.cpp b/tests/unit/test_main.cpp
new file mode 100644
index 0000000..75a6112
--- /dev/null
+++ b/tests/unit/test_main.cpp
@@ -0,0 +1,3 @@
+#define CATCH_CONFIG_MAIN
+//#define CATCH_CONFIG_ENABLE_BENCHMARKING
+#include "catch2/catch.hpp"