1/* $NetBSD: debug.s,v 1.13 2020/09/18 00:04:58 thorpej Exp $ */ 2 3/*- 4 * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 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 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33__KERNEL_RCSID(6, "$NetBSD: debug.s,v 1.13 2020/09/18 00:04:58 thorpej Exp $") 34 35#include "opt_multiprocessor.h" 36#include "opt_ddb.h" 37#include "opt_kgdb.h" 38 39/* 40 * Debugger glue. 41 */ 42 43 .text 44inc6: .stabs __FILE__,132,0,0,inc6; .loc 1 __LINE__ 45 46/* 47 * Debugger stack. 48 */ 49#define DEBUG_STACK_SIZE 8192 50BSS(debug_stack_bottom, DEBUG_STACK_SIZE) 51 52#define debug_stack_top (debug_stack_bottom + DEBUG_STACK_SIZE) 53 54/* 55 * alpha_debug: 56 * 57 * Single debugger entry point, handling the housekeeping 58 * chores we need to deal with. 59 * 60 * Arguments are: 61 * 62 * a0 a0 from trap 63 * a1 a1 from trap 64 * a2 a2 from trap 65 * a3 kernel trap entry point 66 * a4 frame pointer 67 */ 68NESTED_NOPROFILE(alpha_debug, 5, 64, ra, 69 IM_RA|IM_S0|IM_S1|IM_S2|IM_S3|IM_S4|IM_S5, 0) 70 br pv, 1f 711: LDGP(pv) 72 lda t0, FRAME_SIZE*8(a4) /* what would sp have been? */ 73 stq t0, FRAME_SP*8(a4) /* belatedly save sp for ddb view */ 74 lda sp, -64(sp) /* set up stack frame */ 75 stq s0, (0*8)(sp) /* save s0 ... */ 76 stq s1, (1*8)(sp) 77 stq s2, (2*8)(sp) 78 stq s3, (3*8)(sp) 79 stq s4, (4*8)(sp) 80 stq s5, (5*8)(sp) /* ... through s5 */ 81 stq ra, (6*8)(sp) /* save ra */ 82 83 /* Remember our current stack pointer. */ 84 mov sp, s5 85 86 /* Save off our arguments. */ 87 mov a0, s0 88 mov a1, s1 89 mov a2, s2 90 mov a3, s3 91 mov a4, s4 92 93#if defined(MULTIPROCESSOR) 94 /* Pause all other CPUs. */ 95 ldiq a0, 1 96 CALL(cpu_pause_resume_all) 97#endif 98 99 /* 100 * Switch to the debug stack if we're not on it already. 101 */ 102 lda t0, debug_stack_bottom 103 cmpule sp, t0, t1 /* sp <= debug_stack_bottom */ 104 bne t1, 2f /* yes, switch now */ 105 106 lda t0, debug_stack_top 107 cmpule t0, sp, t1 /* debug_stack_top <= sp? */ 108 bne t1, 3f /* yes, we're on the debug stack */ 109 1102: lda sp, debug_stack_top /* sp <- debug_stack_top */ 111 1123: /* Dispatch to the debugger. */ 113#if defined(KGDB) 114 mov s3, a0 /* a0 == entry (trap type) */ 115 mov s4, a1 /* a1 == frame pointer */ 116 CALL(kgdb_trap) 117 br 9f 118#endif 119#if defined(DDB) 120 mov s0, a1 /* same arguments as the call */ 121 mov s1, a1 /* to alpha_debug() */ 122 mov s2, a2 /* (these may have been clobbered */ 123 mov s3, a3 /* when pausing other CPUs.) */ 124 mov s4, a4 125 CALL(ddb_trap) 126 br 9f 127#endif 1289: /* Debugger return value in v0; switch back to our previous stack. */ 129 mov s5, sp 130 131#if defined(MULTIPROCESSOR) 132 mov v0, s0 133 134 /* Resume all other CPUs. */ 135 mov zero, a0 136 CALL(cpu_pause_resume_all) 137 138 mov s0, v0 139#endif 140 141 ldq s0, (0*8)(sp) /* restore s0 ... */ 142 ldq s1, (1*8)(sp) 143 ldq s2, (2*8)(sp) 144 ldq s3, (3*8)(sp) 145 ldq s4, (4*8)(sp) 146 ldq s5, (5*8)(sp) /* ... through s5 */ 147 ldq ra, (6*8)(sp) /* restore ra */ 148 lda sp, 64(sp) /* pop stack frame */ 149 RET 150 END(alpha_debug) 151