getcontext.S revision 1.1
11.1Smatt/* $NetBSD: getcontext.S,v 1.1 2003/01/19 19:32:39 matt Exp $ */ 21.1Smatt 31.1Smatt/*- 41.1Smatt * Copyright (c) 2003 The NetBSD Foundation, Inc. 51.1Smatt * All rights reserved. 61.1Smatt * 71.1Smatt * This code is derived from software contributed to The NetBSD Foundation 81.1Smatt * by Matt Thomas. 91.1Smatt * 101.1Smatt * Redistribution and use in source and binary forms, with or without 111.1Smatt * modification, are permitted provided that the following conditions 121.1Smatt * are met: 131.1Smatt * 1. Redistributions of source code must retain the above copyright 141.1Smatt * notice, this list of conditions and the following disclaimer. 151.1Smatt * 2. Redistributions in binary form must reproduce the above copyright 161.1Smatt * notice, this list of conditions and the following disclaimer in the 171.1Smatt * documentation and/or other materials provided with the distribution. 181.1Smatt * 3. All advertising materials mentioning features or use of this software 191.1Smatt * must display the following acknowledgement: 201.1Smatt * This product includes software developed by the NetBSD 211.1Smatt * Foundation, Inc. and its contributors. 221.1Smatt * 4. Neither the name of The NetBSD Foundation nor the names of its 231.1Smatt * contributors may be used to endorse or promote products derived 241.1Smatt * from this software without specific prior written permission. 251.1Smatt * 261.1Smatt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 271.1Smatt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 281.1Smatt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 291.1Smatt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 301.1Smatt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 311.1Smatt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 321.1Smatt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 331.1Smatt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 341.1Smatt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 351.1Smatt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 361.1Smatt * POSSIBILITY OF SUCH DAMAGE. 371.1Smatt */ 381.1Smatt 391.1Smatt#include "SYS.h" 401.1Smatt 411.1SmattENTRY(getcontext, 0) 421.1Smatt chmk $SYS_getcontext /* getcontext(oucp) */ 431.1Smatt jcc 1f 441.1Smatt jmp CERROR+2 /* badness happened */ 451.1Smatt 461.1Smatt1: movl 4(%ap),%r2 /* ptr to ucontext */ 471.1Smatt movl 16(%fp),%r3 /* PC to return to */ 481.1Smatt movab 2f,16(%fp) /* let's return early */ 491.1Smatt ret 501.1Smatt /* 511.1Smatt * Now we have the blown away the callframe and argument 521.1Smatt * list so it's as if we've return from the function except 531.1Smatt * we aren't executing the caller's code (yet). So it's 541.1Smatt * the callers state but we still have control. 551.1Smatt */ 561.1Smatt .align 2 571.1Smatt2: movq %ap,(36+12*4)(%r2) /* adjust AP + SP */ 581.1Smatt movl %fp,(36+14*4)(%r2) /* adjust FP */ 591.1Smatt movl %r3,(36+15*4)(%r2) /* adjust PC */ 601.1Smatt jmp (%r3) /* and return */ 61