xref: /titanic_52/usr/src/lib/crt/i386/mach-crt1.s (revision 3e0c804466b61d42dc6a3e1cb114c11681ef181a)
1*3e0c8044SRichard Lowe/*
2*3e0c8044SRichard Lowe * CDDL HEADER START
3*3e0c8044SRichard Lowe *
4*3e0c8044SRichard Lowe * The contents of this file are subject to the terms of the
5*3e0c8044SRichard Lowe * Common Development and Distribution License (the "License").
6*3e0c8044SRichard Lowe * You may not use this file except in compliance with the License.
7*3e0c8044SRichard Lowe *
8*3e0c8044SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*3e0c8044SRichard Lowe * or http://www.opensolaris.org/os/licensing.
10*3e0c8044SRichard Lowe * See the License for the specific language governing permissions
11*3e0c8044SRichard Lowe * and limitations under the License.
12*3e0c8044SRichard Lowe *
13*3e0c8044SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each
14*3e0c8044SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*3e0c8044SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the
16*3e0c8044SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying
17*3e0c8044SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner]
18*3e0c8044SRichard Lowe *
19*3e0c8044SRichard Lowe * CDDL HEADER END
20*3e0c8044SRichard Lowe */
21*3e0c8044SRichard Lowe
22*3e0c8044SRichard Lowe/*
23*3e0c8044SRichard Lowe * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24*3e0c8044SRichard Lowe * Use is subject to license terms.
25*3e0c8044SRichard Lowe */
26*3e0c8044SRichard Lowe#include <sys/asm_linkage.h>
27*3e0c8044SRichard Lowe
28*3e0c8044SRichard Lowe	.file	"mach-crt1.s"
29*3e0c8044SRichard Lowe
30*3e0c8044SRichard Lowe/* global entities defined elsewhere but used here */
31*3e0c8044SRichard Lowe	.globl	_start_crt
32*3e0c8044SRichard Lowe
33*3e0c8044SRichard Lowe/*
34*3e0c8044SRichard Lowe * C language startup routine.
35*3e0c8044SRichard Lowe * Assume that exec code has cleared the direction flag in the TSS.
36*3e0c8044SRichard Lowe * Assume that %esp is set to the addr after the last word pushed.
37*3e0c8044SRichard Lowe * The stack contains (in order): argc, argv[],envp[],...
38*3e0c8044SRichard Lowe * Assume that all of the segment registers are initialized.
39*3e0c8044SRichard Lowe *
40*3e0c8044SRichard Lowe * Allocate a NULL return address and a NULL previous %ebp as if
41*3e0c8044SRichard Lowe * there was a genuine call to _start.
42*3e0c8044SRichard Lowe * debugger stack trace shows _start(argc,argv[0],argv[1],...,envp[0],...)
43*3e0c8044SRichard Lowe */
44*3e0c8044SRichard LoweENTRY_NP(_start)
45*3e0c8044SRichard Lowe	pushl	$0
46*3e0c8044SRichard Lowe	pushl	$0
47*3e0c8044SRichard Lowe	movl	%esp,%ebp		/* The first stack frame */
48*3e0c8044SRichard Lowe
49*3e0c8044SRichard Lowe	/*
50*3e0c8044SRichard Lowe	 * The stack needs to be 16-byte aligned with a 4-byte bias.  See
51*3e0c8044SRichard Lowe	 * comment in lib/libc/i386/gen/makectxt.c.
52*3e0c8044SRichard Lowe	 *
53*3e0c8044SRichard Lowe	 * Note: If you change it, you need to change it in the following
54*3e0c8044SRichard Lowe	 * files as well:
55*3e0c8044SRichard Lowe	 *
56*3e0c8044SRichard Lowe	 *  - lib/libc/i386/threads/machdep.c
57*3e0c8044SRichard Lowe	 *  - lib/libc/i386/gen/makectxt.c
58*3e0c8044SRichard Lowe	 *  - lib/crt/i386/crti.s
59*3e0c8044SRichard Lowe	 */
60*3e0c8044SRichard Lowe	andl	$-16,%esp	/* make main() and exit() be called with */
61*3e0c8044SRichard Lowe	subl	$4,%esp		/* a properly aligned stack pointer */
62*3e0c8044SRichard Lowe	pushl	%edx		/* possible atexit handler */
63*3e0c8044SRichard Lowe	leal	12(%ebp),%edx	/* argv */
64*3e0c8044SRichard Lowe	movl	8(%ebp),%eax	/* argc */
65*3e0c8044SRichard Lowe	pushl	%edx
66*3e0c8044SRichard Lowe	pushl	%eax
67*3e0c8044SRichard Lowe	call	_start_crt
68*3e0c8044SRichard Lowe	hlt
69*3e0c8044SRichard LoweSET_SIZE(_start)
70*3e0c8044SRichard Lowe
71*3e0c8044SRichard Lowe#include "fsr.s"
72*3e0c8044SRichard Lowe
73*3e0c8044SRichard Lowe/*
74*3e0c8044SRichard Lowe * The following is here in case any object module compiled with cc -p
75*3e0c8044SRichard Lowe * was linked into this module.
76*3e0c8044SRichard Lowe */
77*3e0c8044SRichard LoweENTRY_NP(_mcount)
78*3e0c8044SRichard Lowe	.weak	_mcount
79*3e0c8044SRichard Lowe	ret
80*3e0c8044SRichard LoweSET_SIZE(_mcount)
81