_ctx_start.S revision 89177 
1/*
2 * Copyright (c) 2001 Daniel Eischen <deischen@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Neither the name of the author nor the names of its contributors
11 *    may be used to endorse or promote products derived from this software
12 *    without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * $FreeBSD: head/lib/libc/i386/gen/_ctx_start.S 89177 2002-01-10 02:40:59Z deischen $
29 */
30
31#include <machine/asm.h>
32
33/*
34 * _ctx_start((void *func)(int arg1, ..., argn),
35 *            int arg1, ..., argn, ucontext_t *ucp)
36 *
37 * 0(%esp)		- func
38 * 4(%esp)		- arg1
39 * 8(%esp)		- arg2
40 * ...
41 * (4*n)(%esp)		- argn
42 * (4*(n + 1))(%esp)	- ucp, %ebp setup to point here (base of stack)
43 */
44ENTRY(_ctx_start)
45	popl	%eax		/* get start function */
46	call	*%eax		/* call start function */
47	movl	%ebp, %esp	/*
48				 * setup stack for completion routine;
49				 * ucp is now at top of stack
50				 */
51	call	_ctx_done	/* should never return */
52	call	abort		/* fubar */
53	ret
54