Test the map_to function

src/lib.rs

@@ -52,12 +52,7 @@ pub extern fn rust_main(multiboot_information_address: usize) {
         kernel_start as usize, kernel_end as usize, multiboot_start,
         multiboot_end, memory_map_tag.memory_areas());
 
-    for i in 0.. {
-        if let None = frame_allocator.allocate_frame() {
-            println!("allocated {} frames", i);
-            break;
-        }
-    }
+    memory::test_paging(&mut frame_allocator);
 
     loop{}
 }

src/memory/mod.rs

@@ -1,4 +1,5 @@
 pub use self::area_frame_allocator::AreaFrameAllocator;
+pub use self::paging::test_paging;
 use self::paging::PhysicalAddress;
 
 mod area_frame_allocator;

src/memory/paging/mod.rs

@@ -151,3 +151,20 @@ impl ActivePageTable {
         allocator.deallocate_frame(frame);
     }
 }
+
+
+pub fn test_paging<A>(allocator: &mut A)
+    where A: FrameAllocator
+{
+    let mut page_table = unsafe { ActivePageTable::new() };
+
+    let addr = 42 * 512 * 512 * 4096; // 42th P3 entry
+    let page = Page::containing_address(addr);
+    let frame = allocator.allocate_frame().expect("no more frames");
+    println!("None = {:?}, map to {:?}",
+            page_table.translate(addr),
+            frame);
+    page_table.map_to(page, frame, EntryFlags::empty(), allocator);
+    println!("Some = {:?}", page_table.translate(addr));
+    println!("next free frame: {:?}", allocator.allocate_frame());
+}