/*      $NetBSD: swapcontext.S,v 1.8 2013/09/12 15:36:16 joerg Exp $    */

/*-
 * Copyright (c) 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Klaus Klein.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 THE FOUNDATION OR CONTRIBUTORS
 * 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 "SYS.h"

#if defined(LIBC_SCCS) && !defined(lint)
        RCSID("$NetBSD: swapcontext.S,v 1.8 2013/09/12 15:36:16 joerg Exp $")
#endif /* LIBC_SCCS && !lint */


ENTRY(swapcontext)
        mov     %o0, %o2                        /* must save pointer */
        mov     %o1, %o3                        /* must save pointer */
        mov     SYS_getcontext, %g1
        t       ST_SYSCALL
        bcc,a   1f
         stx    %g0, [%o2 + 64 + 11 * 8]        /* gr[_REG_O0] = 0 */
        ERROR()
1:
        add     %o7, 12, %o1
        stx     %o1, [%o2 + 64 + 2 * 8]         /* gr[_REG_nPC] = retaddr + 4 */
        add     %o7, 8, %o1
        stx     %o1, [%o2 + 64 + 1 * 8]         /* gr[_REG_PC] = retaddr */

#if __PIC__ - 0 >= 2
        PIC_PROLOGUE(%g5,%o4)                   /* %g5 = _GLOBAL_OFFSET_TABLE */
        set     _C_LABEL(setcontext), %o5
        ldx     [%g5+%o5], %o4
        jmp     %o4
         mov    %o3, %o0
#elif __PIC__ - 0 >= 1
        PIC_PROLOGUE(%g5,%o4)                   /* %g5 = _GLOBAL_OFFSET_TABLE */
        ldx     [%g5+_C_LABEL(setcontext)], %o4
        jmp     %o4
         mov    %o3, %o0
#else
        ba,a    _C_LABEL(setcontext)
         mov    %o3, %o0
#endif