1/*-
2 * Copyright (c) 2000 Peter Wemm <peter@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. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
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#include <machine/asm.h>
28__FBSDID("$FreeBSD$");
29
30/*
31 * With thanks to John Dyson for the original version of this.
32 */
33
34#include <SYS.h>
35
36/*
37 *                8      12          16         20
38 * rfork_thread(flags, stack_addr, start_fnc, start_arg);
39 *
40 * flags:		Flags to rfork system call.  See rfork(2).
41 * stack_addr:		Top of stack for thread.
42 * start_fnc:		Address of thread function to call in child.
43 * start_arg:		Argument to pass to the thread function in child.
44 */
45
46ENTRY(rfork_thread)
47	pushl	%ebp
48	movl	%esp, %ebp
49	pushl	%esi
50
51	/*
52	 * Push thread info onto the new thread's stack
53	 */
54	movl	12(%ebp), %esi	# get stack addr
55
56	subl	$4, %esi
57	movl	20(%ebp), %eax	# get start argument
58	movl	%eax, (%esi)
59
60	subl	$4, %esi
61	movl	16(%ebp), %eax	# get start thread address
62	movl	%eax, (%esi)
63
64	/*
65	 * Prepare and execute the thread creation syscall
66	 */
67	pushl	8(%ebp)
68	pushl	$0
69	movl	$SYS_rfork, %eax
70	KERNCALL
71	jb 	2f
72
73	/*
74	 * Check to see if we are in the parent or child
75	 */
76	cmpl	$0, %edx
77	jnz	1f
78	addl	$8, %esp
79	popl	%esi
80	movl	%ebp, %esp
81	popl	%ebp
82	ret
83	.p2align 2
84
85	/*
86	 * If we are in the child (new thread), then
87	 * set-up the call to the internal subroutine.  If it
88	 * returns, then call __exit.
89	 */
901:
91	movl	%esi,%esp
92	popl	%eax
93	call	*%eax
94	addl	$4, %esp
95
96	/*
97	 * Exit system call
98	 */
99	pushl	%eax
100	pushl	$0
101#ifdef SYS_exit
102	movl	$SYS_exit, %eax
103#else
104	movl	$SYS_sys_exit, %eax
105#endif
106	KERNCALL
107
108	/*
109	 * Branch here if the thread creation fails:
110	 */
1112:
112	addl	$8, %esp
113	popl	%esi
114	movl	%ebp, %esp
115	popl	%ebp
116	PIC_PROLOGUE
117	jmp	PIC_PLT(HIDENAME(cerror))
118END(rfork_thread)
119
120	.section .note.GNU-stack,"",%progbits
121