/*	$OpenBSD: sigreturn.s,v 1.3 2003/06/02 23:27:48 millert Exp $	*/
/*	$NetBSD: sigreturn.s,v 1.2 1997/04/25 02:22:04 thorpej Exp $	*/

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1980, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * from: Utah $Hdr: locore.s 1.66 92/12/22$
 *
 *	@(#)locore.s	8.6 (Berkeley) 5/27/94
 */

/*
 * NOTICE: This is not a standalone file.  To use it, #include it in
 * your port's locore.s, like so:
 *
 *	#include <m68k/m68k/sigreturn.s>
 */

/*
 * The sigreturn() syscall comes here.  It requires special handling
 * because we must open a hole in the stack to fill in the (possibly much
 * larger) original stack frame.
 */
ASENTRY_NOPROFILE(sigreturn)
	lea	sp@(-84),sp		| leave enough space for largest frame
	movl	sp@(84),sp@		| move up current 8 byte frame
	movl	sp@(88),sp@(4)
	movl	#84,sp@-		| default: adjust by 84 bytes
	moveml	#0xFFFF,sp@-		| save user registers
	movl	usp,a0			| save the user SP
	movl	a0,sp@(FR_SP)		|   in the savearea
	movl	#SYS_sigreturn,sp@-	| push syscall number
	jbsr	_C_LABEL(syscall)	| handle it
	addql	#4,sp			| pop syscall#
	movl	sp@(FR_SP),a0		| grab and restore
	movl	a0,usp			|   user SP
	lea	sp@(FR_HW),a1		| pointer to HW frame
	movw	sp@(FR_ADJ),d0		| do we need to adjust the stack?
	jeq	Lsigr1			| no, just continue
	moveq	#92,d1			| total size
	subw	d0,d1			|  - hole size = frame size
	lea	a1@(92),a0		| destination
	addw	d1,a1			| source
	lsrw	#1,d1			| convert to word count
	subqw	#1,d1			| minus 1 for dbf
Lsigrlp:
	movw	a1@-,a0@-		| copy a word
	dbf	d1,Lsigrlp		| continue
	movl	a0,a1			| new HW frame base
Lsigr1:
	movl	a1,sp@(FR_SP)		| new SP value
	moveml	sp@+,#0x7FFF		| restore user registers
	movl	sp@,sp			| and our SP
	jra	_ASM_LABEL(rei)		| all done