redhat man page for setup

SETUP(2)						     Linux Programmer's Manual							  SETUP(2)

NAME
       setup - setup devices and file systems, mount root file system

SYNOPSIS
       #include <unistd.h>

       _syscall0(int, setup);

       int setup(void);

DESCRIPTION
       setup  is  called  once	from within linux/init/main.c.	It calls initialization functions for devices and file systems configured into the
       kernel and then mounts the root file system.

       No user process may call setup.	Any user process, even a process with super-user permission, will receive EPERM.

RETURN VALUE
       setup always returns -1 for a user process.

ERRORS
       EPERM  Always, for a user process.

CONFORMING TO
       This function is Linux specific, and should not be used in programs intended to be portable, or indeed in any programs at all.  Since Linux
       2.1.121, no such function exists anymore.  The calling sequence varied: it has had a single parameter void * BIOS and at other times a sin-
       gle parameter int magic.

Linux 1.2.9							    1996-05-03								  SETUP(2)