Interface cleanup

src/kernel/include/memory.h

@@ -43,4 +43,6 @@ void free_page(void *P4, uintptr_t addr, int free);
 
 extern union PTE BootP4;
 extern int kernel_start, kernel_end;
+
+void memory_init();
 #endif

src/kernel/include/multiboot.h

@@ -10,6 +10,8 @@ struct kernel_boot_data_st
   void *mmap;
 };
 
+#define MMAP_FREE 1
+
 extern struct kernel_boot_data_st kernel_boot_data;
 
 int multiboot_init(uint64_t magic, void *mboot_info);