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swapcontext.S revision 1.4 
      1 /*	$NetBSD: swapcontext.S,v 1.4 2011/01/25 02:38:15 matt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Matt Thomas.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include "SYS.h"
     33 
     34 #ifdef LIBC_SCCS
     35 RCSID("$NetBSD: swapcontext.S,v 1.4 2011/01/25 02:38:15 matt Exp $")
     36 #endif
     37 
     38 ENTRY(swapcontext, 0)
     39 	clrl	%r0			/* assume getcontext succeeds */
     40 	chmk	$SYS_getcontext		/* getcontext(oucp) */
     41 	jcc	1f
     42 	jmp	CERROR+2		/* something bad happened */
     43 
     44 1:	movl	4(%ap),%r0		/* get oucp */
     45 	addl3	(%ap),$(5+1),%r1	/* size of callframe + arglist (LW) */
     46 	bbs	$13,6(%fp),2f		/* was this a CALLG? */
     47 	movl	$5,%r1			/* size of callframe (in LW) */
     48 2:	movl	8(%fp),(36+12*4)(%r0)		/* restore AP */
     49 	moval	(%sp)[%r1],(36+13*4)(%r0)	/* restore SP */
     50 	movq	12(%fp),(36+14*4)(%r0)		/* restore FP + PC */
     51 
     52 	pushl	8(%ap)
     53 	calls	$1,_C_LABEL(setcontext) /* setcontext(ucp) */
     54 	ret
     55 END(swapcontext)
     56