11.10Sriastrad/*	$NetBSD: _lwp.c,v 1.10 2025/04/27 16:15:40 riastradh Exp $	*/
21.2Sthorpej
31.2Sthorpej/*-
41.2Sthorpej * Copyright (c) 2001 The NetBSD Foundation, Inc.
51.2Sthorpej * All rights reserved.
61.2Sthorpej *
71.2Sthorpej * This code is derived from software contributed to The NetBSD Foundation
81.2Sthorpej * by Nathan J. Williams.
91.2Sthorpej *
101.2Sthorpej * Redistribution and use in source and binary forms, with or without
111.2Sthorpej * modification, are permitted provided that the following conditions
121.2Sthorpej * are met:
131.2Sthorpej * 1. Redistributions of source code must retain the above copyright
141.2Sthorpej *    notice, this list of conditions and the following disclaimer.
151.2Sthorpej * 2. Redistributions in binary form must reproduce the above copyright
161.2Sthorpej *    notice, this list of conditions and the following disclaimer in the
171.2Sthorpej *    documentation and/or other materials provided with the distribution.
181.2Sthorpej *
191.2Sthorpej * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
201.2Sthorpej * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
211.2Sthorpej * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
221.2Sthorpej * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
231.2Sthorpej * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
241.2Sthorpej * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
251.2Sthorpej * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
261.2Sthorpej * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
271.2Sthorpej * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
281.2Sthorpej * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
291.2Sthorpej * POSSIBILITY OF SUCH DAMAGE.
301.2Sthorpej */
311.2Sthorpej
321.4Slukem#include <sys/cdefs.h>
331.4Slukem#if defined(LIBC_SCCS) && !defined(lint)
341.10Sriastrad__RCSID("$NetBSD: _lwp.c,v 1.10 2025/04/27 16:15:40 riastradh Exp $");
351.4Slukem#endif /* LIBC_SCCS and not lint */
361.4Slukem
371.3Skleink#include "namespace.h"
381.9Sriastrad
391.10Sriastrad#include <sys/param.h>
401.2Sthorpej#include <sys/types.h>
411.9Sriastrad
421.2Sthorpej#include <lwp.h>
431.2Sthorpej#include <stdlib.h>
441.9Sriastrad#include <ucontext.h>
451.2Sthorpej
461.2Sthorpejvoid
471.2Sthorpej_lwp_makecontext(ucontext_t *u, void (*start)(void *),
481.2Sthorpej    void *arg, void *private, caddr_t stack_base, size_t stack_size)
491.2Sthorpej{
501.2Sthorpej	__greg_t *gr;
511.2Sthorpej
521.2Sthorpej	getcontext(u);
531.2Sthorpej	gr = u->uc_mcontext.__gregs;
541.2Sthorpej
551.2Sthorpej	u->uc_link = NULL;
561.2Sthorpej
571.2Sthorpej	u->uc_stack.ss_sp = stack_base;
581.2Sthorpej	u->uc_stack.ss_size = stack_size;
591.2Sthorpej
601.2Sthorpej	gr[_REG_PC] = (unsigned long)start;
611.2Sthorpej	gr[_REG_T12] = (unsigned long) start;
621.2Sthorpej	gr[_REG_RA] = (unsigned long) _lwp_exit;
631.2Sthorpej	gr[_REG_A0] = (unsigned long) arg;
641.10Sriastrad	gr[_REG_SP] = ((unsigned long) (stack_base + stack_size)) &
651.10Sriastrad	    ~STACK_ALIGNBYTES;
661.2Sthorpej	gr[_REG_S6] = 0;
671.6Sjoerg	gr[_REG_UNIQUE] = (unsigned long)private;
681.6Sjoerg
691.7Smanu	u->uc_flags |= _UC_TLSBASE;
701.2Sthorpej}
71