contextspfunc.S revision 1.1 
1/*	$NetBSD: contextspfunc.S,v 1.1 2025/04/21 02:33:44 riastradh Exp $	*/
2
3/*-
4 * Copyright (c) 2025 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#define	_LOCORE
30
31#include <machine/asm.h>
32
33RCSID("$NetBSD: contextspfunc.S,v 1.1 2025/04/21 02:33:44 riastradh Exp $")
34
35#include "SYS.h"
36
37	.text
38
39/*
40 * contextspfunc()
41 *
42 *	makecontext(3) function.  Store the stack pointer on entry at
43 *	the global variable contextsp and call contextdone.
44 */
45LEAF(contextspfunc)
46	move	t0, sp			/* save stack pointer just in case */
47
48	PIC_PROLOGUE(contextspfunc)	/* gp setup, sets t3 */
49
50	PTR_LA	t1, _C_LABEL(contextsp)	/* load t1 := &contextsp */
51	 NOP_L				/* load hazard */
52	PTR_S	t0, 0(t1)		/* store contextsp := stack pointer */
53
54	PIC_TAILCALL(contextdone)
55END(contextspfunc)
56