1 /* $NetBSD: _lwp.c,v 1.3 2003/04/07 21:04:22 kleink Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the NetBSD 18 * Foundation, Inc. and its contributors. 19 * 4. Neither the name of The NetBSD Foundation nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include "namespace.h" 37 #include <sys/types.h> 38 #include <ucontext.h> 39 #include <lwp.h> 40 #include <stdlib.h> 41 42 void 43 _lwp_makecontext(ucontext_t *u, void (*start)(void *), void *arg, 44 void *private, caddr_t stack_base, size_t stack_size) 45 { 46 __greg_t *gr; 47 unsigned long *sp; 48 49 getcontext(u); 50 gr = u->uc_mcontext.__gregs; 51 52 u->uc_link = NULL; 53 54 u->uc_stack.ss_sp = stack_base; 55 u->uc_stack.ss_size = stack_size; 56 57 58 sp = (ulong *)(stack_base + stack_size); 59 sp = (ulong *)((ulong)sp & ~0x07); 60 61 /* Make room for the fake caller stack frame (CCFSZ, only in words) */ 62 sp -= 8 + 8 + 1 + 6 + 1; 63 64 /* Entering (*start)(arg), return is to _lwp_exit */ 65 gr[_REG_PC] = (ulong) start; 66 gr[_REG_nPC] = (ulong) start + 4; 67 gr[_REG_O0] = (ulong)arg; 68 gr[_REG_O6] = (ulong)sp; 69 gr[_REG_O7] = (ulong)_lwp_exit - 8; 70 71 /* XXX: uwe: why do we need this? */ 72 /* create loopback in the window save area on the stack? */ 73 sp[8+6] = (ulong)sp; /* %i6 */ 74 sp[8+7] = (ulong)_lwp_exit - 8; /* %i7 */ 75 } 76