diff --git a/libs/gui/BufferSlot.cpp b/libs/gui/BufferSlot.cpp
new file mode 100644
index 0000000..6b5d77a
--- /dev/null
+++ b/libs/gui/BufferSlot.cpp
@@ -0,0 +1,15 @@
+#include <gui/BufferSlot.h>
+
+namespace android {
+
+const char* BufferSlot::bufferStateName(BufferState state) {
+    switch (state) {
+        case BufferSlot::DEQUEUED: return "DEQUEUED";
+        case BufferSlot::QUEUED: return "QUEUED";
+        case BufferSlot::FREE: return "FREE";
+        case BufferSlot::ACQUIRED: return "ACQUIRED";
+        default: return "Unknown";
+    }
+}
+
+} // namespace android