1/* $NetBSD: swapcontext.S,v 1.8 2014/05/23 02:34:19 uebayasi Exp $ */ 2 3/*- 4 * Copyright (c) 1999 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Klaus Klein. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <machine/asm.h> 33#if defined(LIBC_SCCS) && !defined(lint) 34 RCSID("$NetBSD: swapcontext.S,v 1.8 2014/05/23 02:34:19 uebayasi Exp $") 35#endif /* LIBC_SCCS && !lint */ 36 37ENTRY(swapcontext) 38 movl 4(%esp),%ecx 39 PIC_PROLOGUE 40 pushl %ecx /* push oucp */ 41#ifdef __PIC__ 42 call PIC_PLT(_C_LABEL(_getcontext)) 43#else 44 call _C_LABEL(_getcontext) 45#endif 46 addl $4,%esp /* pop oucp */ 47 PIC_EPILOGUE 48 testl %eax,%eax 49 jnz 2f 50 movl 4(%esp),%ecx 51 movl 0(%esp),%edx 52 movl %edx,(36 + 14 * 4)(%ecx) /* Adjust saved %eip ... */ 53#ifdef __PIC__ 54 movl %ebx,(36 + 8 * 4)(%ecx) /* ... clobbered PIC reg ... */ 55#endif 56 leal 4(%esp),%edx 57 movl %edx,(36 + 17 * 4)(%ecx) /* ... and %esp. */ 58 /* Note: oucp->%eax has been cleared by getcontext(). */ 59 movl 8(%esp),%ecx 60 PIC_PROLOGUE 61 pushl %ecx /* push ucp */ 62#ifdef __PIC__ 63 call PIC_PLT(_C_LABEL(setcontext)) 64#else 65 call _C_LABEL(setcontext) 66#endif 67 addl $4,%esp /* pop ucp */ 68 PIC_EPILOGUE 69 /* No need to error-check: setcontext() must have failed. */ 702: ret 71END(swapcontext) 72