feat(pfa): Add PageFrameAllocator class

kernel/src/Memory/PageFrameAllocator.hpp

@@ -0,0 +1,28 @@
+/*
+    * PageFrameAllocator.hpp
+    * Memory allocator for physical pages
+    * Copyright (c) 2025 Daniel Hammer
+*/
+
+#pragma once
+#include "Memmap.hpp"
+
+namespace Memory {
+    class PageFrameAllocator {
+        struct Page {
+            std::size_t size;
+            Page* next;
+        };
+
+        Page head{};
+
+        LargestSection g_section;
+public:
+        PageFrameAllocator(LargestSection section);
+
+        void* Allocate();
+        void Free(void* ptr);
+    };
+
+    extern PageFrameAllocator* g_pfa;
+};