From 84c337e6f006222970ea57d74057dbe9b7e03595 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 13 Apr 2017 17:59:12 +0200
Subject: [PATCH] Create a memory module with a Frame struct and FrameAllocator
 trait

---
 src/lib.rs        |  1 +
 src/memory/mod.rs | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 src/memory/mod.rs

diff --git a/src/lib.rs b/src/lib.rs
index 4c9185e..71d2229 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,6 +11,7 @@ extern crate multiboot2;
 
 #[macro_use]
 mod vga_buffer;
+mod memory;
 
 #[no_mangle]
 pub extern fn rust_main(multiboot_information_address: usize) {
diff --git a/src/memory/mod.rs b/src/memory/mod.rs
new file mode 100644
index 0000000..553a0d5
--- /dev/null
+++ b/src/memory/mod.rs
@@ -0,0 +1,17 @@
+pub const PAGE_SIZE: usize = 4096;
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Frame {
+    number: usize,
+}
+
+impl Frame {
+    fn containing_address(address: usize) -> Frame {
+        Frame{ number: address / PAGE_SIZE }
+    }
+}
+
+pub trait FrameAllocator {
+    fn allocate_frame(&mut self) -> Option<Frame>;
+    fn deallocate_frame(&mut self, frame: Frame);
+}