KHeapChunkHeader

memchunkhdr = a data structure describing chunks of memory allocated by the ARM11 kernel.

Here is some code describing the layout of a memory chunk header.

   struct MemoryChunkHeader {
       int num_pages; // size of this chunk in terms of small pages
       void* next;
       void* prev;
       int unk1;
       int unk2;
   };

The "next" and "prev" members are used to implement a linked-list. In fact, chances are this is actually a kernel object inherited from KLinkedList.