diff --git a/sys/i386/isa/isa.c b/sys/i386/isa/isa.c
index a62c658136f3..786de1a98e79 100644
--- a/sys/i386/isa/isa.c
+++ b/sys/i386/isa/isa.c
@@ -203,28 +203,9 @@ isa_alloc_resourcev(device_t child, int type, int *rid,
 int
 isa_load_resourcev(struct resource *re, bus_addr_t *res, bus_size_t count)
 {
-	bus_addr_t	start;
-	bus_space_handle_t bh;
-	int		i;
 
-	bh = rman_get_bushandle(re);
-	if (count > bh->bsh_maxiatsz) {
-		printf("isa_load_resourcev: map size too large\n");
-		return EINVAL;
-	}
-
-	start = rman_get_start(re);
-	for (i = 0; i < bh->bsh_maxiatsz; i++) {
-		if (i < count)
-			bh->bsh_iat[i] = start + res[i];
-		else
-			bh->bsh_iat[i] = start;
-	}
-
-	bh->bsh_iatsz = count;
-	bh->bsh_bam = rman_get_bustag(re)->bs_ra;	/* relocate access */
-
-	return 0;
+	return bus_space_map_load(rman_get_bustag(re), rman_get_bushandle(re),
+				  count, res, 0);
 }
 #endif	/* PC98 */
 
diff --git a/sys/pc98/include/bus.h b/sys/pc98/include/bus.h
index 39111f5620a4..07b7ea3489b7 100644
--- a/sys/pc98/include/bus.h
+++ b/sys/pc98/include/bus.h
@@ -92,7 +92,13 @@
 
 #define BUS_SPACE_UNRESTRICTED	(~0)
 
+/*
+ * address relocation table
+ */
 #define BUS_SPACE_IAT_MAXSIZE	33
+typedef bus_addr_t *bus_space_iat_t;
+
+#define BUS_SPACE_IAT_SZ(IOTARRAY) (sizeof(IOTARRAY)/sizeof(bus_addr_t))
 
 /*
  * Access methods for bus resources and address space.
@@ -223,6 +229,19 @@ void i386_memio_unmap(bus_space_tag_t t, bus_space_handle_t bsh,
 #define bus_space_unmap(t, h, s)					\
 	i386_memio_unmap((t), (h), (s))
 
+/*
+ *      int bus_space_map_load (bus_space_tag_t t, bus_space_handle_t bsh,
+ *          bus_size_t size, bus_space_iat_t iat, u_int flags);
+ *
+ * Load I/O address table of bus space.
+ */
+
+int i386_memio_map_load(bus_space_tag_t t, bus_space_handle_t bsh,
+			bus_size_t size, bus_space_iat_t iat, u_int flags);
+
+#define bus_space_map_load(t, h, s, iat, f)				\
+	i386_memio_map_load((t), (h), (s), (iat), (f))
+
 /*
  *      int bus_space_subregion (bus_space_tag_t t,
  *          bus_space_handle_t bsh, bus_size_t offset, bus_size_t size,
@@ -260,6 +279,9 @@ void i386_memio_free(bus_space_tag_t t, bus_space_handle_t bsh,
 int i386_memio_compare(bus_space_tag_t t1, bus_space_handle_t bsh1,
 		       bus_space_tag_t t2, bus_space_handle_t bsh2);
 
+#define bus_space_compare(t1, h1, t2, h2)				\
+	i386_memio_compare((t1), (h1), (t2), (h2))
+
 /*
  * Access methods for bus resources and address space.
  */
diff --git a/sys/pc98/pc98/busiosubr.c b/sys/pc98/pc98/busiosubr.c
index 79b06cee1b17..dffe5fff7fe5 100644
--- a/sys/pc98/pc98/busiosubr.c
+++ b/sys/pc98/pc98/busiosubr.c
@@ -220,6 +220,31 @@ i386_memio_free(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size)
 	i386_memio_unmap(t, bsh, bsh->bsh_sz);
 }
 
+int
+i386_memio_map_load(bus_space_tag_t t, bus_space_handle_t bsh,
+		    bus_size_t size, bus_space_iat_t iat, u_int flags __unused)
+{
+	int i;
+
+	if (size > bsh->bsh_maxiatsz) {
+		printf("i386_memio_map_load: map size too large\n");
+		return EINVAL;
+	}
+
+	for (i = 0; i < bsh->bsh_maxiatsz; i++) {
+		if (i < size)
+			bsh->bsh_iat[i] = iat[i];
+		else
+			bsh->bsh_iat[i] = 0;
+		bsh->bsh_iat[i] += bsh->bsh_base;
+	}
+
+	bsh->bsh_iatsz = size;
+	bsh->bsh_bam = t->bs_ra;	/* relocate access */
+
+	return 0;
+}
+
 int
 i386_memio_subregion(bus_space_tag_t t, bus_space_handle_t pbsh,
 		     bus_size_t offset, bus_size_t size,