1/* $OpenBSD: setstack.S,v 1.5 2018/08/06 18:39:13 kettenis Exp $ */ 2/* $NetBSD: setstack.S,v 1.2 2002/08/15 01:37:02 briggs Exp $ */ 3 4/* 5 * Copyright (c) 1994 Mark Brinicombe. 6 * Copyright (c) 1994 Brini. 7 * All rights reserved. 8 * 9 * This code is derived from software written for Brini by Mark Brinicombe 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by Brini. 22 * 4. The name of the company nor the name of the author may be used to 23 * endorse or promote products derived from this software without specific 24 * prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 27 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 28 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 30 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * RiscBSD kernel project 39 * 40 * setstack.S 41 * 42 * Miscellaneous routine to play with the stack pointer in different CPU modes 43 * 44 * Eventually this routine can be inline assembly. 45 * 46 * Created : 17/09/94 47 * 48 * Based of kate/display/setstack.s 49 */ 50 51#include <machine/asm.h> 52#include <arm/armreg.h> 53 54/* To set the stack pointer for a particular mode we must switch 55 * to that mode update the banked r13 and then switch back. 56 * This routine provides an easy way of doing this for any mode 57 * 58 * r0 = CPU mode 59 * r1 = stackptr 60 */ 61 62ENTRY(set_stackptr) 63 mrs r3, cpsr /* Switch to the appropriate mode */ 64 bic r2, r3, #(PSR_MODE) 65 orr r2, r2, r0 66 msr cpsr_c, r2 67 68 mov sp, r1 /* Set the stack pointer */ 69 70 msr cpsr_c, r3 /* Restore the old mode */ 71 72 mov pc, lr /* Exit */ 73 74/* To get the stack pointer for a particular mode we must switch 75 * to that mode copy the banked r13 and then switch back. 76 * This routine provides an easy way of doing this for any mode 77 * 78 * r0 = CPU mode 79 */ 80 81ENTRY(get_stackptr) 82 mrs r3, cpsr /* Switch to the appropriate mode */ 83 bic r2, r3, #(PSR_MODE) 84 orr r2, r2, r0 85 msr cpsr_c, r2 86 87 mov r0, sp /* Set the stack pointer */ 88 89 msr cpsr_c, r3 /* Restore the old mode */ 90 91 mov pc, lr /* Exit */ 92