From f1459a552cff88740aebf56541ec57eefc2e3b03 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Tue, 18 Apr 2017 18:18:18 +0200
Subject: [PATCH] Return a memory controller from memory::init

---
 src/memory/mod.rs        | 17 +++++++++++++++--
 src/memory/paging/mod.rs | 11 ++++++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/memory/mod.rs b/src/memory/mod.rs
index 22970bd..2dde292 100644
--- a/src/memory/mod.rs
+++ b/src/memory/mod.rs
@@ -11,8 +11,7 @@ mod stack_allocator;
 
 pub const PAGE_SIZE: usize = 4096;
 
-
-pub fn init(boot_info: &BootInformation) {
+pub fn init(boot_info: &BootInformation) -> MemoryController {
     assert_has_not_been_called!("memory::init must be called only once");
 
     let memory_map_tag = boot_info.memory_map_tag().expect(
@@ -50,6 +49,20 @@ pub fn init(boot_info: &BootInformation) {
     for page in Page::range_inclusive(heap_start_page, heap_end_page) {
         active_table.map(page, paging::WRITABLE, &mut frame_allocator);
     }
+
+    let stack_allocator = {
+        let stack_alloc_start = heap_end_page + 1;
+        let stack_alloc_end = stack_alloc_start + 100;
+        let stack_alloc_range = Page::range_inclusive(stack_alloc_start,
+                                                      stack_alloc_end);
+        stack_allocator::StackAllocator::new(stack_alloc_range)
+    };
+
+    MemoryController {
+        active_table: active_table,
+        frame_allocator: frame_allocator,
+        stack_allocator: stack_allocator,
+    }
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
diff --git a/src/memory/paging/mod.rs b/src/memory/paging/mod.rs
index 98b150c..36a6dcb 100644
--- a/src/memory/paging/mod.rs
+++ b/src/memory/paging/mod.rs
@@ -1,6 +1,6 @@
 pub use self::entry::*;
 pub use self::mapper::Mapper;
-use core::ops::{Deref, DerefMut};
+use core::ops::{Deref, DerefMut, Add};
 use core::ptr::Unique;
 use memory::{PAGE_SIZE, Frame, FrameAllocator};
 use multiboot2::BootInformation;
@@ -55,6 +55,15 @@ impl Page {
     }
 }
 
+impl Add<usize> for Page {
+    type Output = Page;
+
+    fn add(self, rhs: usize) -> Page {
+        Page { number: self.number + rhs }
+    }
+}
+
+
 #[derive(Clone)]
 pub struct PageIter {
     start: Page,