1*e415d488SLionel Sambuc/* $NetBSD: getcontext.S,v 1.6 2011/11/21 16:17:48 chs Exp $ */ 22fe8fb19SBen Gras 32fe8fb19SBen Gras/*- 42fe8fb19SBen Gras * Copyright (c) 2003 The NetBSD Foundation, Inc. 52fe8fb19SBen Gras * All rights reserved. 62fe8fb19SBen Gras * 72fe8fb19SBen Gras * This code is derived from software contributed to The NetBSD Foundation 82fe8fb19SBen Gras * by Matt Thomas. 92fe8fb19SBen Gras * 102fe8fb19SBen Gras * Redistribution and use in source and binary forms, with or without 112fe8fb19SBen Gras * modification, are permitted provided that the following conditions 122fe8fb19SBen Gras * are met: 132fe8fb19SBen Gras * 1. Redistributions of source code must retain the above copyright 142fe8fb19SBen Gras * notice, this list of conditions and the following disclaimer. 152fe8fb19SBen Gras * 2. Redistributions in binary form must reproduce the above copyright 162fe8fb19SBen Gras * notice, this list of conditions and the following disclaimer in the 172fe8fb19SBen Gras * documentation and/or other materials provided with the distribution. 182fe8fb19SBen Gras * 192fe8fb19SBen Gras * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 202fe8fb19SBen Gras * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 212fe8fb19SBen Gras * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 222fe8fb19SBen Gras * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 232fe8fb19SBen Gras * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 242fe8fb19SBen Gras * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 252fe8fb19SBen Gras * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 262fe8fb19SBen Gras * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 272fe8fb19SBen Gras * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 282fe8fb19SBen Gras * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 292fe8fb19SBen Gras * POSSIBILITY OF SUCH DAMAGE. 302fe8fb19SBen Gras */ 312fe8fb19SBen Gras 322fe8fb19SBen Gras#include "SYS.h" 332fe8fb19SBen Gras 34*e415d488SLionel Sambuc#ifdef SYSLIBC_SCCS 35*e415d488SLionel SambucRCSID("$NetBSD: getcontext.S,v 1.6 2011/11/21 16:17:48 chs Exp $") 36*e415d488SLionel Sambuc#endif 37*e415d488SLionel Sambuc 382fe8fb19SBen Gras#ifdef WEAK_ALIAS 392fe8fb19SBen GrasWEAK_ALIAS(getcontext, _getcontext) 402fe8fb19SBen Gras#endif 412fe8fb19SBen Gras 422fe8fb19SBen Gras/* 432fe8fb19SBen Gras * Can't use R4 or R5 since those needed by the phread_switch code. 442fe8fb19SBen Gras */ 452fe8fb19SBen GrasENTRY(_getcontext, 0) 462fe8fb19SBen Gras clrl %r0 /* assume success */ 472fe8fb19SBen Gras chmk $SYS_getcontext /* getcontext(oucp) */ 482fe8fb19SBen Gras jcc 1f 492fe8fb19SBen Gras jmp CERROR+2 /* badness happened */ 502fe8fb19SBen Gras 51*e415d488SLionel Sambuc1: movl 4(%ap),%r0 /* ptr to ucontext */ 52*e415d488SLionel Sambuc movl 16(%fp),%r1 /* PC to return to */ 532fe8fb19SBen Gras movab 2f,16(%fp) /* let's return early */ 542fe8fb19SBen Gras ret 552fe8fb19SBen Gras /* 562fe8fb19SBen Gras * Now we have the blown away the callframe and argument 572fe8fb19SBen Gras * list so it's as if we've return from the function except 582fe8fb19SBen Gras * we aren't executing the caller's code (yet). So it's 592fe8fb19SBen Gras * the callers state but we still have control. 602fe8fb19SBen Gras */ 612fe8fb19SBen Gras _ALIGN_TEXT 62*e415d488SLionel Sambuc2: movq %ap,(36+12*4)(%r0) /* adjust AP + SP */ 63*e415d488SLionel Sambuc movl %fp,(36+14*4)(%r0) /* adjust FP */ 64*e415d488SLionel Sambuc movl %r3,(36+15*4)(%r0) /* adjust PC */ 65*e415d488SLionel Sambuc clrl %r0 66*e415d488SLionel Sambuc jmp (%r1) /* and return */ 67*e415d488SLionel SambucEND(_getcontext) 68