lib: fs: implement memory-mapped file i/o

lib/libfs/interface.h

@@ -17,9 +17,8 @@ extern kern_status_t fs_msg_open(
 	int *out_err,
 	void *arg);
 extern kern_status_t fs_msg_close(
-	const struct msg_endpoint *sender,
-	const char *path,
-	int flags,
+	xpc_context_t *ctx,
+	const xpc_endpoint_t *sender,
 	int *out_err,
 	void *arg);
 
@@ -31,5 +30,21 @@ extern kern_status_t fs_msg_read(
 	size_t *out_nr_read,
 	xpc_buffer_t *out_data,
 	void *arg);
+extern kern_status_t fs_msg_write(
+	xpc_context_t *ctx,
+	const xpc_endpoint_t *sender,
+	const xpc_buffer_t *data,
+	int *out_err,
+	size_t *out_nr_written,
+	void *arg);
+
+extern kern_status_t fs_msg_map(
+	xpc_context_t *ctx,
+	const xpc_endpoint_t *sender,
+	int prot,
+	int flags,
+	int *out_err,
+	kern_handle_t *out_vmo,
+	void *arg);
 
 #endif