have to actually learn paging so pushing progress for now

kernel/src/allocator.rs

@@ -0,0 +1,13 @@
+use linked_list_allocator::LockedHeap;
+
+#[global_allocator]
+static ALLOCATOR: LockedHeap = LockedHeap::empty();
+
+pub const HEAP_START: *mut u8 = 0x9000_0000 as *mut u8;
+pub const HEAP_SIZE: usize = 100 * 1024;
+
+pub fn init_heap() {
+    unsafe {
+        ALLOCATOR.lock().init(HEAP_START, HEAP_SIZE);
+    }
+}