Add a memory region type to mammoth

lib/mammoth/include/mammoth/memory_region.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdint.h>
+
+class MappedMemoryRegion {
+ public:
+  // FIXME: Introduce optional type to contain error or.
+  static MappedMemoryRegion DirectPhysical(uint64_t phys_addr, uint64_t size);
+  static MappedMemoryRegion ContiguousPhysical(uint64_t size);
+  static MappedMemoryRegion Default(uint64_t size);
+
+  MappedMemoryRegion() {}
+  // TODO: Disallow copy before doing any cleanup here.
+  ~MappedMemoryRegion() {}
+
+  uint64_t paddr() { return paddr_; }
+  uint64_t vaddr() { return vaddr_; }
+
+  operator bool() { return vmmo_cap_ != 0; }
+
+ private:
+  MappedMemoryRegion(uint64_t vmmo_cap, uint64_t paddr, uint64_t vaddr,
+                     uint64_t size)
+      : vmmo_cap_(vmmo_cap), paddr_(paddr), vaddr_(vaddr), size_(size) {}
+  uint64_t vmmo_cap_ = 0;
+  uint64_t paddr_ = 0;
+  uint64_t vaddr_ = 0;
+  uint64_t size_ = 0;
+};