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/asm.h> 52__FBSDID("$FreeBSD$"); 53 54#include <machine/armreg.h> 55 56/* To set the stack pointer for a particular mode we must switch 57 * to that mode update the banked r13 and then switch back. 58 * This routine provides an easy way of doing this for any mode 59 * 60 * r0 = CPU mode 61 * r1 = stackptr 62 */ 63 64ENTRY(set_stackptr) 65 mrs r3, cpsr /* Switch to the appropriate mode */ 66 bic r2, r3, #(PSR_MODE) 67 orr r2, r2, r0 68 msr cpsr_fsxc, r2 69 70 mov sp, r1 /* Set the stack pointer */ 71 72 msr cpsr_fsxc, r3 /* Restore the old mode */ 73 74 mov pc, lr /* Exit */ 75END(set_stackptr) 76/* To get the stack pointer for a particular mode we must switch 77 * to that mode copy the banked r13 and then switch back. 78 * This routine provides an easy way of doing this for any mode 79 * 80 * r0 = CPU mode 81 */ 82 83ENTRY(get_stackptr) 84 mrs r3, cpsr /* Switch to the appropriate mode */ 85 bic r2, r3, #(PSR_MODE) 86 orr r2, r2, r0 87 msr cpsr_fsxc, r2 88 89 mov r0, sp /* Set the stack pointer */ 90 91 msr cpsr_fsxc, r3 /* Restore the old mode */ 92 93 mov pc, lr /* Exit */ 94END(get_stackptr) 95/* End of setstack.S */ 96