diff --git a/sys/sys/memrange.h b/sys/sys/memrange.h
new file mode 100644
index 00000000000..812721fa73b
--- /dev/null
+++ b/sys/sys/memrange.h
@@ -0,0 +1,65 @@
+/*
+ * Memory range attribute operations, peformed on /dev/mem
+ */
+
+/* Memory range attributes */
+#define MDF_UNCACHEABLE		(1<<0)	/* region not cached */
+#define MDF_WRITECOMBINE	(1<<1)	/* region supports "write combine" action */
+#define MDF_WRITETHROUGH	(1<<2)	/* write-through cached */
+#define MDF_WRITEBACK		(1<<3)	/* write-back cached */
+#define MDF_WRITEPROTECT	(1<<4)	/* read-only region */
+#define MDF_ATTRMASK		(0x00ffffff)
+
+#define MDF_FIXBASE		(1<<24)	/* fixed base */
+#define MDF_FIXLEN		(1<<25)	/* fixed length */
+#define MDF_FIRMWARE		(1<<26)	/* set by firmware (XXX not useful?) */
+#define MDF_ACTIVE		(1<<27)	/* currently active */
+#define MDF_BOGUS		(1<<28)	/* we don't like it */
+#define MDF_FIXACTIVE		(1<<29)	/* can't be turned off */
+#define MDF_BUSY		(1<<30)	/* range is in use */
+
+struct mem_range_desc
+{
+	u_int64_t	mr_base;
+	u_int64_t	mr_len;
+	int		mr_flags;
+	char		mr_owner[8];
+};
+
+struct mem_range_op
+{
+	struct mem_range_desc	*mo_desc;
+	int			mo_arg[2];
+#define MEMRANGE_SET_UPDATE	0
+#define MEMRANGE_SET_REMOVE	1
+	/* XXX want a flag that says "set and undo when I exit" */
+};
+
+#define MEMRANGE_GET	_IOWR('m', 50, struct mem_range_op)
+#define MEMRANGE_SET	_IOW('m', 51, struct mem_range_op)
+
+#ifdef KERNEL
+
+MALLOC_DECLARE(M_MEMDESC);
+
+struct mem_range_softc;
+struct mem_range_ops
+{
+	void	(*init)(struct mem_range_softc *sc);
+	int	(*set)(struct mem_range_softc *sc, struct mem_range_desc *mrd, int *arg);
+};
+
+struct mem_range_softc 
+{
+	struct mem_range_ops	*mr_op;
+	int			mr_cap;
+	int			mr_ndesc;
+	struct mem_range_desc 	*mr_desc;
+};
+
+extern struct mem_range_softc mem_range_softc;
+
+extern void mem_range_attr_get(struct mem_range_desc *mrd, int *arg);
+extern int mem_range_attr_set(struct mem_range_desc *mrd, int *arg);
+#endif
+