From 3e59283c1994f9a4a8135450c9ae35521b5a6514 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Wed, 13 Mar 2019 14:30:13 +0100
Subject: [PATCH] Create an `EmptyFrameAllocator`

---
 src/memory.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/memory.rs b/src/memory.rs
index 5f40ff97..1e9dd9bf 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -54,3 +54,12 @@ pub fn create_example_mapping(
     let map_to_result = unsafe { mapper.map_to(page, frame, flags, frame_allocator) };
     map_to_result.expect("map_to failed").flush();
 }
+
+/// A FrameAllocator that always returns `None`.
+pub struct EmptyFrameAllocator;
+
+impl FrameAllocator<Size4KiB> for EmptyFrameAllocator {
+    fn allocate_frame(&mut self) -> Option<PhysFrame> {
+        None
+    }
+}