freebsd-dev/lib/libc/i386/gen/_ctx_start.S
Konstantin Belousov 3d5fa0356e Replace absolute addressing in the call instructions with position-independend
calls. This eliminates TEXTREL from libc, making its text segment relocatable.

PR:	i386/85242
Approved by:	kan (mentor)
MFC after:	1 month
2006-06-05 14:59:33 +00:00

52 lines
1.9 KiB
ArmAsm

/*
* Copyright (c) 2001 Daniel Eischen <deischen@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
/*
* _ctx_start((void *func)(int arg1, ..., argn),
* int arg1, ..., argn, ucontext_t *ucp)
*
* 0(%esp) - func
* 4(%esp) - arg1
* 8(%esp) - arg2
* ...
* (4*n)(%esp) - argn
* (4*(n + 1))(%esp) - ucp, %ebp setup to point here (base of stack)
*/
ENTRY(_ctx_start)
popl %eax /* get start function */
call *%eax /* call start function */
PIC_PROLOGUE
movl %esi, %esp /*
* setup stack for completion routine;
* ucp is now at top of stack
*/
call PIC_PLT(_ctx_done) /* should never return */
call PIC_PLT(abort) /* fubar */
ret