feat: start adding physical memory allocator

kernel/include/memory/sections.h

@@ -17,3 +17,14 @@ void for_each_reserved_section(Fn&& fn) {
     for (auto* s = __reserved_ranges_start__; s < __reserved_ranges_end__; ++s)
         fn(*s);
 }
+
+inline bool is_in_reserved_section(paddr_t ptr, size_t size = 1) {
+    bool res = false;
+    for_each_reserved_section([&](const KernelSection& section) {
+        if (ptr.address < section.phys_end().address &&
+            section.phys_start().address < ptr.address + size) {
+            res = true;
+        }
+    });
+    return res;
+}