lib/libc/arch/arm/gen/_lwp.c

   1 /*      $NetBSD: _lwp.c,v 1.8 2012/03/22 09:32:04 he Exp $      */
   2
   3 /*
   4  * Copyright (c) 2001 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include <sys/cdefs.h>
  39 #if defined(LIBC_SCCS) && !defined(lint)
  40 __RCSID("$NetBSD: _lwp.c,v 1.8 2012/03/22 09:32:04 he Exp $");
  41 #endif /* LIBC_SCCS and not lint */
  42
  43 #include "namespace.h"
  44 #include <sys/types.h>
  45 #include <ucontext.h>
  46 #include <lwp.h>
  47 #include <stdlib.h>
  48
  49 void
  50 _lwp_makecontext(ucontext_t *u, void (*start)(void *),
  51     void *arg, void *private, caddr_t stack_base, size_t stack_size)
  52 {
  53         uintptr_t sp;
  54
  55         getcontext(u);
  56         u->uc_link = NULL;
  57
  58         u->uc_stack.ss_sp = stack_base;
  59         u->uc_stack.ss_size = stack_size;
  60
  61         sp = (uintptr_t)stack_base + stack_size;
  62         /*
  63          * Note: We make sure the stack is 8-byte aligned, here.
  64          */
  65
  66         u->uc_mcontext.__gregs[_REG_R0] = (__greg_t)(uintptr_t)arg;
  67         u->uc_mcontext.__gregs[_REG_SP] = ((__greg_t)sp) & ~7;
  68         u->uc_mcontext.__gregs[_REG_LR] = (__greg_t)(uintptr_t)_lwp_exit;
  69         u->uc_mcontext.__gregs[_REG_PC] = (__greg_t)(uintptr_t)start;
  70         u->uc_mcontext._mc_tlsbase = (__greg_t)(uintptr_t)private;
  71         u->uc_flags |= _UC_TLSBASE;
  72 }