diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
new file mode 100644
index 0000000..6c175d4
--- /dev/null
+++ b/arch/sandbox/cpu/os.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <os.h>
+
+/* Operating System Interface */
+
+ssize_t os_read(int fd, void *buf, size_t count)
+{
+	return read(fd, buf, count);
+}
+
+ssize_t os_write(int fd, const void *buf, size_t count)
+{
+	return write(fd, buf, count);
+}
+
+int os_open(const char *pathname, int flags)
+{
+	return open(pathname, flags);
+}
+
+int os_close(int fd)
+{
+	return close(fd);
+}
+
+void os_exit(int exit_code)
+{
+	exit(exit_code);
+}