diff --git a/lpc_aspeed.hpp b/lpc_aspeed.hpp
index 91e24af..47c7a4a 100644
--- a/lpc_aspeed.hpp
+++ b/lpc_aspeed.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "internal/sys.hpp"
 #include "lpc_interface.hpp"
 
 #include <memory>
@@ -10,13 +11,20 @@
 class LpcMapperAspeed : public LpcMapperInterface
 {
   public:
-    static std::unique_ptr<LpcMapperInterface> createAspeedMapper();
+    static std::unique_ptr<LpcMapperInterface>
+        createAspeedMapper(size_t regionSize);
 
-    /* TODO: Needs reserved memory region's physical address and size. */
-    LpcMapperAspeed() = default;
+    LpcMapperAspeed(size_t regionSize, const flash::internal::Sys* sys =
+                                           &flash::internal::sys_impl) :
+        regionSize(regionSize),
+        sys(sys){};
 
     std::pair<std::uint32_t, std::uint32_t>
         mapWindow(std::uint32_t address, std::uint32_t length) override;
+
+  private:
+    size_t regionSize;
+    const flash::internal::Sys* sys;
 };
 
 } // namespace blobs