Index: kernel/generic/src/console/cmd.c
===================================================================
--- kernel/generic/src/console/cmd.c	(revision 67f11a04d9b9007cff6be59c182bd35c4f3ee076)
+++ kernel/generic/src/console/cmd.c	(revision 6be2c13c42be6b2f450ca654c0b1f32fb186f909)
@@ -727,6 +727,6 @@
 	else
 #endif
-		ptr = (uint8_t *) km_map(argv[0].intval, sizeof(uint8_t),
-		    PAGE_NOT_CACHEABLE);
+		ptr = (uint8_t *) km_map(
+		    argv[0].intval, sizeof(uint8_t), 0);
 
 	const uint8_t val = pio_read_8(ptr);
@@ -749,4 +749,95 @@
  */
 static int cmd_pio_read_16(cmd_arg_t *argv)
+{
+	uint16_t *ptr = NULL;
+
+#ifdef IO_SPACE_BOUNDARY
+	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
+		ptr = (void *) argv[0].intval;
+	else
+#endif
+		ptr = (uint16_t *) km_map(
+		    argv[0].intval, sizeof(uint16_t), 0);
+
+	const uint16_t val = pio_read_16(ptr);
+	printf("read %" PRIxn ": %" PRIx16 "\n", argv[0].intval, val);
+
+#ifdef IO_SPACE_BOUNDARY
+	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
+		return 1;
+#endif
+
+	km_unmap((uintptr_t) ptr, sizeof(uint16_t));
+	return 1;
+}
+
+/** Read 4 bytes from phys memory or io port.
+ *
+ * @param argv Argument vector.
+ *
+ * @return 0 on failure, 1 on success.
+ */
+static int cmd_pio_read_32(cmd_arg_t *argv)
+{
+	uint32_t *ptr = NULL;
+
+#ifdef IO_SPACE_BOUNDARY
+	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
+		ptr = (void *) argv[0].intval;
+	else
+#endif
+		ptr = (uint32_t *) km_map(
+		    argv[0].intval, sizeof(uint32_t), 0);
+
+	const uint32_t val = pio_read_32(ptr);
+	printf("read %" PRIxn ": %" PRIx32 "\n", argv[0].intval, val);
+
+#ifdef IO_SPACE_BOUNDARY
+	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
+		return 1;
+#endif
+
+	km_unmap((uintptr_t) ptr, sizeof(uint32_t));
+	return 1;
+}
+
+/** Write 1 byte to phys memory or io port.
+ *
+ * @param argv Argument vector.
+ *
+ * @return 0 on failure, 1 on success.
+ */
+static int cmd_pio_write_8(cmd_arg_t *argv)
+{
+	uint8_t *ptr = NULL;
+
+#ifdef IO_SPACE_BOUNDARY
+	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
+		ptr = (void *) argv[0].intval;
+	else
+#endif
+		ptr = (uint8_t *) km_map(argv[0].intval, sizeof(uint8_t),
+		    PAGE_WRITE);
+
+	printf("write %" PRIxn ": %" PRIx8 "\n", argv[0].intval,
+	    (uint8_t) argv[1].intval);
+	pio_write_8(ptr, (uint8_t) argv[1].intval);
+
+#ifdef IO_SPACE_BOUNDARY
+	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
+		return 1;
+#endif
+
+	km_unmap((uintptr_t) ptr, sizeof(uint8_t));
+	return 1;
+}
+
+/** Write 2 bytes to phys memory or io port.
+ *
+ * @param argv Argument vector.
+ *
+ * @return 0 on failure, 1 on success.
+ */
+static int cmd_pio_write_16(cmd_arg_t *argv)
 {
 	uint16_t *ptr = NULL;
@@ -758,8 +849,9 @@
 #endif
 		ptr = (uint16_t *) km_map(argv[0].intval, sizeof(uint16_t),
-		    PAGE_NOT_CACHEABLE);
-
-	const uint16_t val = pio_read_16(ptr);
-	printf("read %" PRIxn ": %" PRIx16 "\n", argv[0].intval, val);
+		    PAGE_WRITE);
+
+	printf("write %" PRIxn ": %" PRIx16 "\n", argv[0].intval,
+	    (uint16_t) argv[1].intval);
+	pio_write_16(ptr, (uint16_t) argv[1].intval);
 
 #ifdef IO_SPACE_BOUNDARY
@@ -772,5 +864,5 @@
 }
 
-/** Read 4 bytes from phys memory or io port.
+/** Write 4 bytes to phys memory or io port.
  *
  * @param argv Argument vector.
@@ -778,5 +870,5 @@
  * @return 0 on failure, 1 on success.
  */
-static int cmd_pio_read_32(cmd_arg_t *argv)
+static int cmd_pio_write_32(cmd_arg_t *argv)
 {
 	uint32_t *ptr = NULL;
@@ -788,97 +880,5 @@
 #endif
 		ptr = (uint32_t *) km_map(argv[0].intval, sizeof(uint32_t),
-		    PAGE_NOT_CACHEABLE);
-
-	const uint32_t val = pio_read_32(ptr);
-	printf("read %" PRIxn ": %" PRIx32 "\n", argv[0].intval, val);
-
-#ifdef IO_SPACE_BOUNDARY
-	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
-		return 1;
-#endif
-
-	km_unmap((uintptr_t) ptr, sizeof(uint32_t));
-	return 1;
-}
-
-/** Write 1 byte to phys memory or io port.
- *
- * @param argv Argument vector.
- *
- * @return 0 on failure, 1 on success.
- */
-static int cmd_pio_write_8(cmd_arg_t *argv)
-{
-	uint8_t *ptr = NULL;
-
-#ifdef IO_SPACE_BOUNDARY
-	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
-		ptr = (void *) argv[0].intval;
-	else
-#endif
-		ptr = (uint8_t *) km_map(argv[0].intval, sizeof(uint8_t),
-		    PAGE_NOT_CACHEABLE);
-
-	printf("write %" PRIxn ": %" PRIx8 "\n", argv[0].intval,
-	    (uint8_t) argv[1].intval);
-	pio_write_8(ptr, (uint8_t) argv[1].intval);
-
-#ifdef IO_SPACE_BOUNDARY
-	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
-		return 1;
-#endif
-
-	km_unmap((uintptr_t) ptr, sizeof(uint8_t));
-	return 1;
-}
-
-/** Write 2 bytes to phys memory or io port.
- *
- * @param argv Argument vector.
- *
- * @return 0 on failure, 1 on success.
- */
-static int cmd_pio_write_16(cmd_arg_t *argv)
-{
-	uint16_t *ptr = NULL;
-
-#ifdef IO_SPACE_BOUNDARY
-	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
-		ptr = (void *) argv[0].intval;
-	else
-#endif
-		ptr = (uint16_t *) km_map(argv[0].intval, sizeof(uint16_t),
-		    PAGE_NOT_CACHEABLE);
-
-	printf("write %" PRIxn ": %" PRIx16 "\n", argv[0].intval,
-	    (uint16_t) argv[1].intval);
-	pio_write_16(ptr, (uint16_t) argv[1].intval);
-
-#ifdef IO_SPACE_BOUNDARY
-	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
-		return 1;
-#endif
-
-	km_unmap((uintptr_t) ptr, sizeof(uint16_t));
-	return 1;
-}
-
-/** Write 4 bytes to phys memory or io port.
- *
- * @param argv Argument vector.
- *
- * @return 0 on failure, 1 on success.
- */
-static int cmd_pio_write_32(cmd_arg_t *argv)
-{
-	uint32_t *ptr = NULL;
-
-#ifdef IO_SPACE_BOUNDARY
-	if ((void *) argv->intval < IO_SPACE_BOUNDARY)
-		ptr = (void *) argv[0].intval;
-	else
-#endif
-		ptr = (uint32_t *) km_map(argv[0].intval, sizeof(uint32_t),
-		    PAGE_NOT_CACHEABLE);
+		    PAGE_WRITE);
 
 	printf("write %" PRIxn ": %" PRIx32 "\n", argv[0].intval,
Index: kernel/generic/src/ipc/irq.c
===================================================================
--- kernel/generic/src/ipc/irq.c	(revision 67f11a04d9b9007cff6be59c182bd35c4f3ee076)
+++ kernel/generic/src/ipc/irq.c	(revision 6be2c13c42be6b2f450ca654c0b1f32fb186f909)
@@ -93,5 +93,5 @@
 #endif
 		ranges[i].base = km_map(pbase[i], ranges[i].size,
-		    PAGE_READ | PAGE_WRITE | PAGE_KERNEL | PAGE_NOT_CACHEABLE);
+		    PAGE_WRITE);
 		if (!ranges[i].base) {
 			ranges_unmap(ranges, i);
Index: kernel/generic/src/main/kinit.c
===================================================================
--- kernel/generic/src/main/kinit.c	(revision 67f11a04d9b9007cff6be59c182bd35c4f3ee076)
+++ kernel/generic/src/main/kinit.c	(revision 6be2c13c42be6b2f450ca654c0b1f32fb186f909)
@@ -250,5 +250,5 @@
 		uintptr_t page = km_map(init.tasks[i].paddr,
 		    init.tasks[i].size,
-		    PAGE_READ | PAGE_WRITE | PAGE_CACHEABLE);
+		    PAGE_WRITE | PAGE_CACHEABLE);
 		assert(page);
 
Index: kernel/generic/src/mm/as.c
===================================================================
--- kernel/generic/src/mm/as.c	(revision 67f11a04d9b9007cff6be59c182bd35c4f3ee076)
+++ kernel/generic/src/mm/as.c	(revision 6be2c13c42be6b2f450ca654c0b1f32fb186f909)
@@ -1217,8 +1217,8 @@
 NO_TRACE static unsigned int area_flags_to_page_flags(unsigned int aflags)
 {
-	unsigned int flags = PAGE_USER | PAGE_PRESENT;
-
-	if (aflags & AS_AREA_READ)
-		flags |= PAGE_READ;
+	unsigned int flags = PAGE_USER;
+
+	// TODO: AS_AREA_READ currently has no effect.
+	// Readability is implied.
 
 	if (aflags & AS_AREA_WRITE)
Index: kernel/generic/src/mm/km.c
===================================================================
--- kernel/generic/src/mm/km.c	(revision 67f11a04d9b9007cff6be59c182bd35c4f3ee076)
+++ kernel/generic/src/mm/km.c	(revision 6be2c13c42be6b2f450ca654c0b1f32fb186f909)
@@ -257,5 +257,5 @@
 	if (frame) {
 		page = km_map(frame, PAGE_SIZE,
-		    PAGE_READ | PAGE_WRITE | PAGE_CACHEABLE);
+		    PAGE_WRITE | PAGE_CACHEABLE);
 		if (!page) {
 			frame_free(frame, 1);