feat: frame allocation

src/main.rs

@@ -15,13 +15,40 @@ pub extern "C" fn _start() -> ! {
     serial::init().unwrap();
 
     arch::init();
-    let _boot_info = boot::load_boot_info().unwrap();
+    let boot_info = boot::load_boot_info().unwrap();
+
+    let mut allocator = memory::FrameAllocator::new(
+        boot_info.memory_regions(),
+        memory::DirectMap::new(boot_info.hhdm_offset),
+    )
+    .expect("failed to create frame allocator");
+
+    let initial = allocator.free_frames();
+
+    let first = allocator.alloc().unwrap();
+    let second = allocator.alloc().unwrap();
+    let third = allocator.alloc().unwrap();
+
+    assert_ne!(first, second);
+    assert_ne!(second, third);
+    assert_eq!(allocator.free_frames(), initial - 3);
 
-    let addr = 0xDEADBEEF as *mut u32;
     unsafe {
-        *addr = 0xDEADBEEF;
+        allocator.dealloc(second);
+        allocator.dealloc(first);
+        allocator.dealloc(third);
     }
 
+    assert_eq!(allocator.free_frames(), initial);
+
+    let a = allocator.alloc().unwrap();
+    let b = allocator.alloc().unwrap();
+    let c = allocator.alloc().unwrap();
+
+    assert_ne!(a, b);
+    assert_ne!(b, c);
+    assert_ne!(a, c);
+
     hcf();
 }