diff --git a/src/mem.rs b/src/mem.rs
index 717e793..7bf138b 100644
--- a/src/mem.rs
+++ b/src/mem.rs
@@ -339,9 +339,9 @@ impl Ram {
 
 #[derive(Clone)]
 pub struct DeviceEntry {
-    base: PageNum,
-    size: PageNum,
-    interface: Arc<dyn MemDeviceInterface>,
+    pub base: PageNum,
+    pub size: PageNum,
+    pub interface: Arc<dyn MemDeviceInterface>,
 }
 
 pub trait MemDeviceInterface {