1/* $NetBSD: setstack.S,v 1.6 2013/08/18 06:29:29 matt 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#include <arm/armreg.h> 50#include <machine/asm.h> 51 52 RCSID("$NetBSD: setstack.S,v 1.6 2013/08/18 06:29:29 matt Exp $") 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 RET /* Exit */ 73END(set_stackptr) 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 /* Switch to the appropriate mode */ 84 bic r2, r3, #(PSR_MODE) 85 orr r2, r2, r0 86 msr cpsr_c, r2 87 88 mov r0, sp /* Get the stack pointer */ 89 90 msr cpsr_c, r3 /* Restore the old mode */ 91 92 RET /* Exit */ 93END(get_stackptr) 94 95/* End of setstack.S */ 96