1129198Scognet/* $NetBSD: setstack.S,v 1.1 2001/07/28 13:28:03 chris Exp $ */ 2129198Scognet 3139735Simp/*- 4129198Scognet * Copyright (c) 1994 Mark Brinicombe. 5129198Scognet * Copyright (c) 1994 Brini. 6129198Scognet * All rights reserved. 7129198Scognet * 8129198Scognet * This code is derived from software written for Brini by Mark Brinicombe 9129198Scognet * 10129198Scognet * Redistribution and use in source and binary forms, with or without 11129198Scognet * modification, are permitted provided that the following conditions 12129198Scognet * are met: 13129198Scognet * 1. Redistributions of source code must retain the above copyright 14129198Scognet * notice, this list of conditions and the following disclaimer. 15129198Scognet * 2. Redistributions in binary form must reproduce the above copyright 16129198Scognet * notice, this list of conditions and the following disclaimer in the 17129198Scognet * documentation and/or other materials provided with the distribution. 18129198Scognet * 3. All advertising materials mentioning features or use of this software 19129198Scognet * must display the following acknowledgement: 20129198Scognet * This product includes software developed by Brini. 21129198Scognet * 4. The name of the company nor the name of the author may be used to 22129198Scognet * endorse or promote products derived from this software without specific 23129198Scognet * prior written permission. 24129198Scognet * 25129198Scognet * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 26129198Scognet * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 27129198Scognet * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28129198Scognet * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 29129198Scognet * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 30129198Scognet * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 31129198Scognet * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32129198Scognet * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33129198Scognet * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34129198Scognet * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35129198Scognet * SUCH DAMAGE. 36129198Scognet * 37129198Scognet * RiscBSD kernel project 38129198Scognet * 39129198Scognet * setstack.S 40129198Scognet * 41129198Scognet * Miscellaneous routine to play with the stack pointer in different CPU modes 42129198Scognet * 43129198Scognet * Eventually this routine can be inline assembly. 44129198Scognet * 45129198Scognet * Created : 17/09/94 46129198Scognet * 47129198Scognet * Based of kate/display/setstack.s 48129198Scognet * 49129198Scognet */ 50129198Scognet 51129198Scognet#include <machine/armreg.h> 52129198Scognet#include <machine/asm.h> 53129198Scognet__FBSDID("$FreeBSD$"); 54129198Scognet 55129198Scognet/* To set the stack pointer for a particular mode we must switch 56129198Scognet * to that mode update the banked r13 and then switch back. 57129198Scognet * This routine provides an easy way of doing this for any mode 58129198Scognet * 59129198Scognet * r0 = CPU mode 60129198Scognet * r1 = stackptr 61129198Scognet */ 62129198Scognet 63129198ScognetENTRY(set_stackptr) 64129198Scognet mrs r3, cpsr_all /* Switch to the appropriate mode */ 65129198Scognet bic r2, r3, #(PSR_MODE) 66129198Scognet orr r2, r2, r0 67129198Scognet msr cpsr_all, r2 68129198Scognet 69129198Scognet mov sp, r1 /* Set the stack pointer */ 70129198Scognet 71129198Scognet msr cpsr_all, r3 /* Restore the old mode */ 72129198Scognet 73129198Scognet mov pc, lr /* Exit */ 74129198Scognet 75129198Scognet/* To get the stack pointer for a particular mode we must switch 76129198Scognet * to that mode copy the banked r13 and then switch back. 77129198Scognet * This routine provides an easy way of doing this for any mode 78129198Scognet * 79129198Scognet * r0 = CPU mode 80129198Scognet */ 81129198Scognet 82129198ScognetENTRY(get_stackptr) 83129198Scognet mrs r3, cpsr_all /* Switch to the appropriate mode */ 84129198Scognet bic r2, r3, #(PSR_MODE) 85129198Scognet orr r2, r2, r0 86129198Scognet msr cpsr_all, r2 87129198Scognet 88129198Scognet mov r0, sp /* Set the stack pointer */ 89129198Scognet 90129198Scognet msr cpsr_all, r3 /* Restore the old mode */ 91129198Scognet 92129198Scognet mov pc, lr /* Exit */ 93129198Scognet 94129198Scognet/* End of setstack.S */ 95