1/*	$NetBSD: setstack.S,v 1.1 2001/07/28 13:28:03 chris Exp $	*/
2
3/*-
4 * Copyright (c) 1994 Mark Brinicombe.
5 * Copyright (c) 1994 Brini.
6 * All rights reserved.
7 *
8 * This code is derived from software written for Brini by Mark Brinicombe
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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by Brini.
21 * 4. The name of the company nor the name of the author may be used to
22 *    endorse or promote products derived from this software without specific
23 *    prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * RiscBSD kernel project
38 *
39 * setstack.S
40 *
41 * Miscellaneous routine to play with the stack pointer in different CPU modes
42 *
43 * Eventually this routine can be inline assembly.
44 *
45 * Created      : 17/09/94
46 *
47 * Based of kate/display/setstack.s
48 *
49 */
50
51#include <machine/armreg.h>
52#include <machine/asm.h>
53__FBSDID("$FreeBSD$");
54
55/* To set the stack pointer for a particular mode we must switch
56 * to that mode update the banked r13 and then switch back.
57 * This routine provides an easy way of doing this for any mode
58 *
59 * r0 = CPU mode
60 * r1 = stackptr
61 */
62
63ENTRY(set_stackptr)
64        mrs	r3, cpsr_all		/* Switch to the appropriate mode */
65	bic	r2, r3, #(PSR_MODE)
66	orr	r2, r2, r0
67        msr	cpsr_all, r2
68
69	mov	sp, r1			/* Set the stack pointer */
70
71        msr	cpsr_all, r3		/* Restore the old mode */
72
73	mov	pc, lr			/* Exit */
74
75/* To get the stack pointer for a particular mode we must switch
76 * to that mode copy the banked r13 and then switch back.
77 * This routine provides an easy way of doing this for any mode
78 *
79 * r0 = CPU mode
80 */
81
82ENTRY(get_stackptr)
83        mrs	r3, cpsr_all		/* Switch to the appropriate mode */
84	bic	r2, r3, #(PSR_MODE)
85	orr	r2, r2, r0
86        msr	cpsr_all, r2
87
88	mov	r0, sp			/* Set the stack pointer */
89
90        msr	cpsr_all, r3		/* Restore the old mode */
91
92	mov	pc, lr			/* Exit */
93
94/* End of setstack.S */
95