/* $OpenBSD: _setjmp.S,v 1.14 2016/09/22 18:23:58 guenther Exp $ */
/*-
 * Copyright (c) 2002 Steve Murphree, Jr.
 * All rights reserved.
 *
 * 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 by Steve Murphree, Jr.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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"

/*
 * C library -- _setjmp, _longjmp
 *
 *      _longjmp(a,v)
 * will generate a "return(v)" from the last call to
 *      _setjmp(a)
 * by restoring registers from the stack.  The previous signal state is
 * neither saved nor restored.
 *
 * For m88k, we define our jmp_buf length to be the size of 21 (_JBLEN) longs.
 * The buffer layout is as follows:
 *
 * jmp_buf[0]           return address
 * jmp_buf[1]           unused
 * jmp_buf[2 to 19]     r14 to r31
 * jmp_buf[20]          setjmp type
 */

#define U_SETJMP_SIG    0x1764

/*
int _setjmp(jmp_buf env);
 */
ENTRY(_setjmp)
        st      %r1, %r2,0      /* save registers to the environment buffer */
        st      %r14,%r2,8
        st      %r15,%r2,12
        st      %r16,%r2,16
        st      %r17,%r2,20
        st      %r18,%r2,24
        st      %r19,%r2,28
        st      %r20,%r2,32
        st      %r21,%r2,36
        st      %r22,%r2,40
        st      %r23,%r2,44
        st      %r24,%r2,48
        st      %r25,%r2,52
        st      %r26,%r2,56
        st      %r27,%r2,60
        st      %r28,%r2,64
        st      %r29,%r2,68
        st      %r30,%r2,72
        st      %r31,%r2,76
        or      %r4,%r0,U_SETJMP_SIG    /* setjmp type to _setjmp */
        st      %r4,%r2,80
        jmp.n   %r1
         or     %r2,%r0,0               /* return 0 */
END(_setjmp)

/*
void _longjmp(jmp_buf env, int val);
 */
ENTRY(_longjmp)
        bcnd    eq0,%r2,2f      /* check for bad environment buffer address. */
        ld      %r4,%r2,80      /* check setjmp type. */
        cmp     %r4,%r4,U_SETJMP_SIG    /* should be U_SETJMP_SIG */
        bb1     ne,%r4,2f       /* if != U_SETJMP_SIG, abort. */
        
        ld      %r14,%r2,8      /* restore registers from the environment buffer */
        ld      %r15,%r2,12
        ld      %r16,%r2,16
        ld      %r17,%r2,20
        ld      %r18,%r2,24
        ld      %r19,%r2,28
        ld      %r20,%r2,32
        ld      %r21,%r2,36
        ld      %r22,%r2,40
        ld      %r23,%r2,44
        ld      %r24,%r2,48
        ld      %r25,%r2,52
        ld      %r26,%r2,56
        ld      %r27,%r2,60
        ld      %r28,%r2,64
        ld      %r29,%r2,68
        ld      %r30,%r2,72
        ld      %r31,%r2,76
        ld      %r1,%r2,0               /* restore r1 */
        bcnd.n  ne0,%r3,1f
         or     %r2,%r3,%r0
        or      %r2,%r0,1               /* never return zero! */
1:      jmp     %r1

2:      br      _HIDDEN(abort)          /* NO RETURN */
END(_longjmp)