minix/lib/libc/arch/i386/gen/swapcontext.S

71 lines
2.5 KiB
ArmAsm
Raw Normal View History

/* $NetBSD: swapcontext.S,v 1.6 2008/04/28 20:22:56 martin Exp $ */
/*-
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
#if defined(LIBC_SCCS) && !defined(lint)
RCSID("$NetBSD: swapcontext.S,v 1.6 2008/04/28 20:22:56 martin Exp $")
#endif /* LIBC_SCCS && !lint */
ENTRY(swapcontext)
movl 4(%esp),%ecx
PIC_PROLOGUE
pushl %ecx /* push oucp */
#ifdef PIC
call PIC_PLT(_C_LABEL(_getcontext))
#else
call _C_LABEL(_getcontext)
#endif
addl $4,%esp /* pop oucp */
PIC_EPILOGUE
testl %eax,%eax
jnz 2f
movl 4(%esp),%ecx
movl 0(%esp),%edx
movl %edx,(36 + 14 * 4)(%ecx) /* Adjust saved %eip ... */
#ifdef PIC
movl %ebx,(36 + 8 * 4)(%ecx) /* ... clobbered PIC reg ... */
#endif
leal 4(%esp),%edx
movl %edx,(36 + 17 * 4)(%ecx) /* ... and %esp. */
/* Note: oucp->%eax has been cleared by getcontext(). */
movl 8(%esp),%ecx
PIC_PROLOGUE
pushl %ecx /* push ucp */
#ifdef PIC
call PIC_PLT(_C_LABEL(setcontext))
#else
call _C_LABEL(setcontext)
#endif
addl $4,%esp /* pop ucp */
PIC_EPILOGUE
/* No need to error-check: setcontext() must have failed. */
2: ret