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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* This crt1.o module is provided as the bare minimum required to build
* a 64-bit executable with gcc. It is installed in /usr/lib/amd64
* where it will be picked up by gcc, along with crti.o and crtn.o
*/
.ident "%Z%%M% %I% %E% SMI"
.file "crt1.s"
.globl _start
/* global entities defined elsewhere but used here */
.globl main
.globl __fpstart
.globl exit
.globl _exit
.weak _DYNAMIC
.section .data
.weak environ
.set environ,_environ
.globl _environ
.type _environ,@object
.size _environ,8
.align 8
_environ:
.8byte 0x0
.globl __environ_lock
.type __environ_lock,@object
.size __environ_lock,24
.align 8
__environ_lock:
.zero 24
.globl ___Argv
.type ___Argv,@object
.size ___Argv,8
.align 8
___Argv:
.8byte 0x0
.section .text
.align 8
/*
* The SVR4/i386 ABI (pages 3-29) says that when the entry
* point runs registers' %rbp, %rsp, %rdx values are specified
* the following:
*
* %rbp The content of this register is unspecified at
* process initialization time, but the user code should mark
* the deepest stack frame by setting the frame pointer to zero.
* No other frame's %ebp should have a zero value.
*
* %rsp Performing its usual job, the stack pointer holds the address
* of the bottom of the stack, which is guaranteed to be
* quadword aligned.
*
* The stack contains the arguments and environment:
* ...
* envp[0] (16+(8*argc))(%rsp)
* NULL (8+(8*argc))(%rsp)
* ...
* argv[0] 8(%rsp)
* argc 0(%rsp)
*
* %rdx In a conforming program, this register contains a function
* pointer that the application should register with atexit(BA_OS).
* This function is used for shared object termination code
* [see Dynamic Linking in Chapter 5 of the System V ABI].
*
*/
.type _start,@function
_start:
/*
* Allocate a NULL return address and a NULL previous %rbp as if
* there was a genuine call to _start.
*/
pushq $0
pushq $0
movq %rsp,%rbp /* The first stack frame */
/*
* The stack now is
*
* envp[0] (32+(8*argc))(%rsp) - (A)
* NULL (24+(8*argc))(%rsp)
* ...
* argv[0] 24(%rbp) - (B)
* argc 16(%rbp)
* 0 8(%rbp)
* 0 0(%rbp)
*/
movq $_DYNAMIC,%rax
testq %rax,%rax
jz 1f
movq %rdx,%rdi /* register rt_do_exit */
call atexit
1:
movq $_fini,%rdi
call atexit
/*
* Calculate the location of the envp array by adding the size of
* the argv array to the start of the argv array.
*/
movq 16(%rbp),%rax /* argc */
movq _environ, %rcx
testq %rcx, %rcx /* check if _environ==0 */
jne 1f
leaq 32(%rbp,%rax,8),%rcx /* (A) */
movq %rcx,_environ /* copy to _environ */
1:
/*
* Force stack alignment - below here there must have been an even
* number of un-popped pushq instructions whenever a call is reached
*/
andq $-16,%rsp
pushq %rdx
leaq 24(%rbp),%rdx /* argv (B) */
movq %rdx,___Argv
pushq %rcx
pushq %rdx
pushq %rax
call __fpstart
call _init
popq %rdi
popq %rsi
popq %rdx
popq %rcx
call main /* main(argc,argv,envp) */
pushq %rax
pushq %rax
movq %rax,%rdi /* and call exit */
call exit
popq %rdi
popq %rdi
call _exit /* if user redefined exit, call _exit */
hlt
.size _start, .-_start
/*
* The following is here in case any object module compiled with cc -p
* was linked into this module.
*/
.globl _mcount
.section .text
.align 8
.type _mcount,@function
_mcount:
ret
.size _mcount, .-_mcount
.globl __longdouble_used
.section .data
.align 8
.type __longdouble_used,@object
.size __longdouble_used,4
__longdouble_used:
.4byte 0
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