1/* $NetBSD: makecontext.c,v 1.2 2003/01/18 11:15:08 thorpej 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/cdefs.h> 33#if defined(LIBC_SCCS) && !defined(lint) 34__RCSID("$NetBSD: makecontext.c,v 1.2 2003/01/18 11:15:08 thorpej Exp $"); 35#endif 36 37#include <inttypes.h> 38#include <stddef.h> 39#include <ucontext.h> 40#include "extern.h" 41 42#include <stdarg.h> 43 44void 45makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...) 46{ 47 __greg_t *gr = ucp->uc_mcontext.__gregs; 48 int i; 49 unsigned long *sp; 50 va_list ap; 51 52 sp = (unsigned long *) 53 ((unsigned long)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size); 54 /* Make room for: rwindow, struct return pointer, argd, argx */ 55 sp -= 8 + 8 + 1 + 6 + 1; /* CCFSZ, only in words */ 56 /* CCFSZ provides space for up to 7 arguments, add more if necessary */ 57 if (argc > 7) 58 sp -= argc - 7; 59 /* Align on double-word boundary. */ 60 sp = (unsigned long *)((unsigned long)sp & ~0x7); 61 62 gr[_REG_O6] = (__greg_t)sp; 63 gr[_REG_PC] = (__greg_t)func; 64 gr[_REG_nPC] = (__greg_t)func + 4; 65 gr[_REG_O7] = (__greg_t)_resumecontext - 8; 66 67 va_start(ap, argc); 68 /* Pass up to 6 arguments in %o0..%o5. */ 69 for (i = 0; i < argc && i < 6; i++) 70 gr[_REG_O0 + i] = va_arg(ap, unsigned long); 71 /* Pass any additional arguments on the stack. */ 72 for (/* i = 6 */; i < argc; i++) 73 sp[8 + 8 + 1 + 6 + (i - 6)] = va_arg(ap, unsigned long); 74 va_end(ap); 75} 76