1/* $NetBSD: swapcontext.S,v 1.3 2015/03/27 23:23:14 matt Exp $ */ 2 3/*- 4 * Copyright (c) 2001 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 "SYS.h" 33#include "assym.h" 34 35__RCSID("$NetBSD: swapcontext.S,v 1.3 2015/03/27 23:23:14 matt Exp $") 36 37#define CALLFRAME_UCP CALLFRAME_S1 38#define CALLFRAME_OUCP CALLFRAME_S0 39 40ENTRY(swapcontext) 41 addi sp, sp, -CALLFRAME_SIZ # adjust stack 42 REG_S ra, CALLFRAME_RA(sp) # save return address 43 REG_S a0, CALLFRAME_OUCP(sp) # save oucp 44 REG_S a1, CALLFRAME_UCP(sp) # save ucp 45 46 call PLT(_C_LABEL(_getcontext)) # getcontext(oucp) 47 mv t0, a0 # save return value 48 49 REG_L ra, CALLFRAME_RA(sp) # restore return address 50 REG_L a0, CALLFRAME_UCP(sp) # load ucp 51 REG_L a1, CALLFRAME_OUCP(sp) # load oucp for adjustment 52 addi sp, sp, CALLFRAME_SIZ # restore stack 53 54 bnez t0, 1f # error? yes, cleanup 55 56 REG_S ra, UC_GREGS_PC(a1) # pc <- ra 57 REG_S sp, UC_GREGS_SP(a1) # adjust sp 58 59 tail PLT(_C_LABEL(setcontext)) # setcontext(ucp) 60 611: ret # simply return 62END(swapcontext) 63