diff --git a/runtime/adainclude/system.ads b/runtime/adainclude/system.ads
new file mode 100644
index 0000000..bd9aea4
--- /dev/null
+++ b/runtime/adainclude/system.ads
@@ -0,0 +1,39 @@
+package System
+   with Pure is
+
+   type Name is (Light_Runtime_RP2040);
+   System_Name : constant Name := Light_Runtime_RP2040;
+
+   Min_Int : constant := Long_Long_Integer'First;
+   Max_Int : constant := Long_Long_Integer'Last;
+
+   Storage_Unit : constant := 8;
+   Word_Size : constant := 4 * Storage_Unit;
+   Memory_Size : constant := 2 ** Word_Size;
+   Max_Binary_Modulus : constant := 2 ** Word_Size;
+   Max_NonBinary_Modulus : constant := 2 ** Word_Size - 1;
+
+   type Address is private
+      with Preelaborable_Initialization;
+   Null_Address : constant Address;
+
+   function "<" (Left, Right : Address) return Boolean
+      with Import, Convention => Intrinsic;
+   function "<=" (Left, Right : Address) return Boolean
+      with Import, Convention => Intrinsic;
+   function ">" (Left, Right : Address) return Boolean
+      with Import, Convention => Intrinsic;
+   function ">=" (Left, Right : Address) return Boolean
+      with Import, Convention => Intrinsic;
+   function "=" (Left, Right : Address) return Boolean
+      with Import, Convention => Intrinsic;
+
+   type Bit_Order is (High_Order_First, Low_Order_First);
+   Default_Bit_Order : constant Bit_Order := Low_Order_First;
+
+private
+
+   type Address is mod Memory_Size;
+   Null_Address : constant Address := 0;
+
+end System;