1*452fee26Schs/* $NetBSD: getcontext.S,v 1.6 2011/11/21 16:17:48 chs Exp $ */ 295b5cce5Smatt 395b5cce5Smatt/*- 495b5cce5Smatt * Copyright (c) 2003 The NetBSD Foundation, Inc. 595b5cce5Smatt * All rights reserved. 695b5cce5Smatt * 795b5cce5Smatt * This code is derived from software contributed to The NetBSD Foundation 895b5cce5Smatt * by Matt Thomas. 995b5cce5Smatt * 1095b5cce5Smatt * Redistribution and use in source and binary forms, with or without 1195b5cce5Smatt * modification, are permitted provided that the following conditions 1295b5cce5Smatt * are met: 1395b5cce5Smatt * 1. Redistributions of source code must retain the above copyright 1495b5cce5Smatt * notice, this list of conditions and the following disclaimer. 1595b5cce5Smatt * 2. Redistributions in binary form must reproduce the above copyright 1695b5cce5Smatt * notice, this list of conditions and the following disclaimer in the 1795b5cce5Smatt * documentation and/or other materials provided with the distribution. 1895b5cce5Smatt * 1995b5cce5Smatt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 2095b5cce5Smatt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 2195b5cce5Smatt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 2295b5cce5Smatt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 2395b5cce5Smatt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 2495b5cce5Smatt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 2595b5cce5Smatt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 2695b5cce5Smatt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 2795b5cce5Smatt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 2895b5cce5Smatt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 2995b5cce5Smatt * POSSIBILITY OF SUCH DAMAGE. 3095b5cce5Smatt */ 3195b5cce5Smatt 3295b5cce5Smatt#include "SYS.h" 3395b5cce5Smatt 34787e823fSmatt#ifdef SYSLIBC_SCCS 35*452fee26SchsRCSID("$NetBSD: getcontext.S,v 1.6 2011/11/21 16:17:48 chs Exp $") 36787e823fSmatt#endif 37787e823fSmatt 3861687fc2Smatt#ifdef WEAK_ALIAS 3961687fc2SmattWEAK_ALIAS(getcontext, _getcontext) 4061687fc2Smatt#endif 4161687fc2Smatt 4294face2fSmatt/* 4394face2fSmatt * Can't use R4 or R5 since those needed by the phread_switch code. 4494face2fSmatt */ 4561687fc2SmattENTRY(_getcontext, 0) 4694face2fSmatt clrl %r0 /* assume success */ 4795b5cce5Smatt chmk $SYS_getcontext /* getcontext(oucp) */ 4895b5cce5Smatt jcc 1f 4995b5cce5Smatt jmp CERROR+2 /* badness happened */ 5095b5cce5Smatt 51*452fee26Schs1: movl 4(%ap),%r0 /* ptr to ucontext */ 52*452fee26Schs movl 16(%fp),%r1 /* PC to return to */ 5395b5cce5Smatt movab 2f,16(%fp) /* let's return early */ 5495b5cce5Smatt ret 5595b5cce5Smatt /* 5695b5cce5Smatt * Now we have the blown away the callframe and argument 5795b5cce5Smatt * list so it's as if we've return from the function except 5895b5cce5Smatt * we aren't executing the caller's code (yet). So it's 5995b5cce5Smatt * the callers state but we still have control. 6095b5cce5Smatt */ 6194face2fSmatt _ALIGN_TEXT 62*452fee26Schs2: movq %ap,(36+12*4)(%r0) /* adjust AP + SP */ 63*452fee26Schs movl %fp,(36+14*4)(%r0) /* adjust FP */ 64*452fee26Schs movl %r3,(36+15*4)(%r0) /* adjust PC */ 65*452fee26Schs clrl %r0 66*452fee26Schs jmp (%r1) /* and return */ 67787e823fSmattEND(_getcontext) 68