/* $NetBSD: makecontext.c,v 1.4 2003/01/22 13:44:36 scw Exp $ */ /* * Copyright 2003 Wasabi Systems, Inc. * All rights reserved. * * Written by Steve C. Woodford for Wasabi Systems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed for the NetBSD Project by * Wasabi Systems, Inc. * 4. The name of Wasabi Systems, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #if defined(LIBC_SCCS) && !defined(lint) __RCSID("$NetBSD: makecontext.c,v 1.4 2003/01/22 13:44:36 scw Exp $"); #endif #include #include #include #include "extern.h" #include #include void makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...) { __greg_t *gr = ucp->uc_mcontext.__gregs; register_t *sp; register_t r; va_list ap; int i; sp = (register_t *) (((intptr_t)ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ~7); if (argc > 8) sp -= (argc - 8); gr[_REG_PC] = (__greg_t)(intptr_t)func; gr[_REG_R(18)] = (__greg_t)(intptr_t)_resumecontext; gr[_REG_SP] = (__greg_t)(intptr_t)sp; gr[_REG_FP] = 0; gr[_REG_USR] = 0x000f; /* r0-r31 are dirty */ /* * The new context inherits the global variable/constant pointers * in r26 and r27. * * XXXSCW: I've never actually seen these used anywhere, so this * may well be unnecessary... */ __asm __volatile("or r26, r63, %0" : "=r"(r)); gr[_REG_R(26)] = r; __asm __volatile("or r27, r63, %0" : "=r"(r)); gr[_REG_R(27)] = r; /* * Ensure the branch target registers contain sane values * or else the kernel will refuse to restore the context. */ gr[_REG_TR(0)] = 0; gr[_REG_TR(1)] = 0; gr[_REG_TR(2)] = 0; gr[_REG_TR(3)] = 0; gr[_REG_TR(4)] = 0; gr[_REG_TR(5)] = 0; gr[_REG_TR(6)] = 0; gr[_REG_TR(7)] = 0; /* * Ensure the FPSCR is valid */ ucp->uc_mcontext.__fpregs.__fp_scr = SH5_FPSCR_DN_FLUSH_ZERO; va_start(ap, argc); /* * First 8 args are passed in r2-r9 */ for (i = 0; i < argc && i < 8; i++) gr[_REG_R(i + 2)] = (register_t)va_arg(ap, long); /* * Additional args are passed on the stack as 64-bit quantities */ for (argc -= i; argc > 0; argc--) *sp++ = (register_t)va_arg(ap, long); va_end(ap); }