diff --git a/src/lib/bit.ml b/src/core/bit.ml
similarity index 100%
rename from src/lib/bit.ml
rename to src/core/bit.ml
diff --git a/src/lib/cartridge.ml b/src/core/cartridge.ml
similarity index 100%
rename from src/lib/cartridge.ml
rename to src/core/cartridge.ml
diff --git a/src/lib/cpu.ml b/src/core/cpu.ml
similarity index 100%
rename from src/lib/cpu.ml
rename to src/core/cpu.ml
diff --git a/src/lib/dune b/src/core/dune
similarity index 74%
rename from src/lib/dune
rename to src/core/dune
index 02401e9..e5fac97 100644
--- a/src/lib/dune
+++ b/src/core/dune
@@ -1,3 +1,3 @@
-(executable
+(library
 	(name oboy)
 	(libraries threads))
diff --git a/src/lib/hexa.ml b/src/core/hexa.ml
similarity index 100%
rename from src/lib/hexa.ml
rename to src/core/hexa.ml
diff --git a/src/lib/interrupt.ml b/src/core/interrupt.ml
similarity index 100%
rename from src/lib/interrupt.ml
rename to src/core/interrupt.ml
diff --git a/src/lib/memory.ml b/src/core/memory.ml
similarity index 94%
rename from src/lib/memory.ml
rename to src/core/memory.ml
index 23ebfd8..bbfd9c1 100644
--- a/src/lib/memory.ml
+++ b/src/core/memory.ml
@@ -13,10 +13,10 @@ open Printf
     @see http://imrannazar.com/GameBoy-Emulation-in-JavaScript:-Memory *)
 
 (** Common addresses *)
-let gDIV  = 0xFF04 (** divider register *)
-let gTIMA = 0xFF05 (** timer counter *)
-let gTMA  = 0xFF06 (** timer modulo *)
-let gTAC  = 0xFF07 (** timer control *)
+let gDIV  = 0xFF04 (* divider register *)
+let gTIMA = 0xFF05 (* timer counter *)
+let gTMA  = 0xFF06 (* timer modulo *)
+let gTAC  = 0xFF07 (* timer control *)
 
 type map = {
   rom_bank_00 : bytes; (* cartridge, 16KB *)
diff --git a/src/lib/oboy.ml b/src/core/oboy.ml
similarity index 100%
rename from src/lib/oboy.ml
rename to src/core/oboy.ml
diff --git a/src/lib/screen.ml b/src/core/screen.ml
similarity index 100%
rename from src/lib/screen.ml
rename to src/core/screen.ml
diff --git a/src/lib/timer.ml b/src/core/timer.ml
similarity index 100%
rename from src/lib/timer.ml
rename to src/core/timer.ml
diff --git a/qt/BackgroundMap.qml b/src/qt/BackgroundMap.qml
similarity index 100%
rename from qt/BackgroundMap.qml
rename to src/qt/BackgroundMap.qml
diff --git a/qt/BackgroundMapForm.ui.qml b/src/qt/BackgroundMapForm.ui.qml
similarity index 100%
rename from qt/BackgroundMapForm.ui.qml
rename to src/qt/BackgroundMapForm.ui.qml
diff --git a/qt/MainForm.ui.qml b/src/qt/MainForm.ui.qml
similarity index 100%
rename from qt/MainForm.ui.qml
rename to src/qt/MainForm.ui.qml
diff --git a/qt/deployment.pri b/src/qt/deployment.pri
similarity index 100%
rename from qt/deployment.pri
rename to src/qt/deployment.pri
diff --git a/qt/main.cpp b/src/qt/main.cpp
similarity index 100%
rename from qt/main.cpp
rename to src/qt/main.cpp
diff --git a/qt/main.qml b/src/qt/main.qml
similarity index 100%
rename from qt/main.qml
rename to src/qt/main.qml
diff --git a/qt/oboy.pro b/src/qt/oboy.pro
similarity index 100%
rename from qt/oboy.pro
rename to src/qt/oboy.pro
diff --git a/qt/qml.qrc b/src/qt/qml.qrc
similarity index 100%
rename from qt/qml.qrc
rename to src/qt/qml.qrc
diff --git a/src/retroarch/retroarch.ml b/src/retroarch/retroarch.ml
new file mode 100644
index 0000000..0ac32e9
--- /dev/null
+++ b/src/retroarch/retroarch.ml
@@ -0,0 +1,7 @@
+open Ctypes
+open PosixTypes
+open Foreign
+
+(* typedef void (RETRO_CALLCONV *retro_video_refresh_t)(const void *data, unsigned width,
+unsigned height, size_t pitch); *)
+let retro_video_refresh_t = ptr void @-> int @-> int @-> returning void