xref: /illumos-gate/usr/src/lib/crt/i386/mach-crt1.S (revision 5d9d9091f564c198a760790b0bfa72c44e17912b)
1*5d9d9091SRichard Lowe/*
2*5d9d9091SRichard Lowe * CDDL HEADER START
3*5d9d9091SRichard Lowe *
4*5d9d9091SRichard Lowe * The contents of this file are subject to the terms of the
5*5d9d9091SRichard Lowe * Common Development and Distribution License (the "License").
6*5d9d9091SRichard Lowe * You may not use this file except in compliance with the License.
7*5d9d9091SRichard Lowe *
8*5d9d9091SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*5d9d9091SRichard Lowe * or http://www.opensolaris.org/os/licensing.
10*5d9d9091SRichard Lowe * See the License for the specific language governing permissions
11*5d9d9091SRichard Lowe * and limitations under the License.
12*5d9d9091SRichard Lowe *
13*5d9d9091SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each
14*5d9d9091SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*5d9d9091SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the
16*5d9d9091SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying
17*5d9d9091SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner]
18*5d9d9091SRichard Lowe *
19*5d9d9091SRichard Lowe * CDDL HEADER END
20*5d9d9091SRichard Lowe */
21*5d9d9091SRichard Lowe
22*5d9d9091SRichard Lowe/*
23*5d9d9091SRichard Lowe * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24*5d9d9091SRichard Lowe * Use is subject to license terms.
25*5d9d9091SRichard Lowe */
26*5d9d9091SRichard Lowe#include <sys/asm_linkage.h>
27*5d9d9091SRichard Lowe
28*5d9d9091SRichard Lowe	.file	"mach-crt1.S"
29*5d9d9091SRichard Lowe	.ident	""
30*5d9d9091SRichard Lowe
31*5d9d9091SRichard Lowe/* global entities defined elsewhere but used here */
32*5d9d9091SRichard Lowe	.globl	_start_crt
33*5d9d9091SRichard Lowe
34*5d9d9091SRichard Lowe/*
35*5d9d9091SRichard Lowe * C language startup routine.
36*5d9d9091SRichard Lowe * Assume that exec code has cleared the direction flag in the TSS.
37*5d9d9091SRichard Lowe * Assume that %esp is set to the addr after the last word pushed.
38*5d9d9091SRichard Lowe * The stack contains (in order): argc, argv[],envp[],...
39*5d9d9091SRichard Lowe * Assume that all of the segment registers are initialized.
40*5d9d9091SRichard Lowe *
41*5d9d9091SRichard Lowe * Allocate a NULL return address and a NULL previous %ebp as if
42*5d9d9091SRichard Lowe * there was a genuine call to _start.
43*5d9d9091SRichard Lowe * debugger stack trace shows _start(argc,argv[0],argv[1],...,envp[0],...)
44*5d9d9091SRichard Lowe */
45*5d9d9091SRichard LoweENTRY_NP(_start)
46*5d9d9091SRichard Lowe	pushl	$0
47*5d9d9091SRichard Lowe	pushl	$0
48*5d9d9091SRichard Lowe	movl	%esp,%ebp		/* The first stack frame */
49*5d9d9091SRichard Lowe
50*5d9d9091SRichard Lowe	/*
51*5d9d9091SRichard Lowe	 * The stack needs to be 16-byte aligned with a 4-byte bias.  See
52*5d9d9091SRichard Lowe	 * comment in lib/libc/i386/gen/makectxt.c.
53*5d9d9091SRichard Lowe	 *
54*5d9d9091SRichard Lowe	 * Note: If you change it, you need to change it in the following
55*5d9d9091SRichard Lowe	 * files as well:
56*5d9d9091SRichard Lowe	 *
57*5d9d9091SRichard Lowe	 *  - lib/libc/i386/threads/machdep.c
58*5d9d9091SRichard Lowe	 *  - lib/libc/i386/gen/makectxt.c
59*5d9d9091SRichard Lowe	 *  - lib/crt/i386/crti.s
60*5d9d9091SRichard Lowe	 */
61*5d9d9091SRichard Lowe	andl	$-16,%esp	/* make main() and exit() be called with */
62*5d9d9091SRichard Lowe	subl	$4,%esp		/* a properly aligned stack pointer */
63*5d9d9091SRichard Lowe	pushl	%edx		/* possible atexit handler */
64*5d9d9091SRichard Lowe	leal	12(%ebp),%edx	/* argv */
65*5d9d9091SRichard Lowe	movl	8(%ebp),%eax	/* argc */
66*5d9d9091SRichard Lowe	pushl	%edx
67*5d9d9091SRichard Lowe	pushl	%eax
68*5d9d9091SRichard Lowe	call	_start_crt
69*5d9d9091SRichard Lowe	hlt
70*5d9d9091SRichard LoweSET_SIZE(_start)
71*5d9d9091SRichard Lowe
72*5d9d9091SRichard Lowe#include "fsr.S"
73*5d9d9091SRichard Lowe
74*5d9d9091SRichard Lowe/*
75*5d9d9091SRichard Lowe * The following is here in case any object module compiled with cc -p
76*5d9d9091SRichard Lowe * was linked into this module.
77*5d9d9091SRichard Lowe */
78*5d9d9091SRichard LoweENTRY_NP(_mcount)
79*5d9d9091SRichard Lowe	.weak	_mcount
80*5d9d9091SRichard Lowe	ret
81*5d9d9091SRichard LoweSET_SIZE(_mcount)
82