1 /* $NetBSD: kgdb_glue.c,v 1.3 2001/05/30 15:24:40 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * All advertising materials mentioning features or use of this software 12 * must display the following acknowledgement: 13 * This product includes software developed by the University of 14 * California, Lawrence Berkeley Laboratories. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. All advertising materials mentioning features or use of this software 25 * must display the following acknowledgement: 26 * This product includes software developed by the University of 27 * California, Berkeley and its contributors. 28 * 4. Neither the name of the University nor the names of its contributors 29 * may be used to endorse or promote products derived from this software 30 * without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 * 44 * @(#)kgdb_glue.c 8.2 (Berkeley) 1/12/94 45 */ 46 47 /* 48 * This file must be compiled with gcc -fno-defer-pop. 49 */ 50 51 #include "opt_kgdb.h" 52 53 #ifdef KGDB 54 55 #include <sys/param.h> 56 57 #include <machine/frame.h> 58 #include <machine/reg.h> 59 60 #ifndef lint 61 static char rcsid[] = "$NetBSD: kgdb_glue.c,v 1.3 2001/05/30 15:24:40 lukem Exp $"; 62 #endif 63 64 #define KGDB_STACKSIZE 0x800 65 #define KGDB_STACKWORDS (KGDB_STACKSIZE / sizeof(u_long)) 66 67 u_long kgdb_stack[KGDB_STACKWORDS]; 68 69 #define getsp(v) asm("movl %%sp, %0" : "=r" (v)) 70 #define setsp(v) asm("movl %0, %%sp" :: "r" (v)) 71 72 static inline void 73 copywords(src, dst, nbytes) 74 register u_long *src, *dst; 75 register u_int nbytes; 76 { 77 u_long *limit = src + (nbytes / sizeof(u_long)); 78 79 do { 80 *dst++ = *src++; 81 } while (src < limit); 82 if (nbytes & 2) 83 *(u_short *)dst = *(u_short *)src; 84 } 85 86 kgdb_trap_glue(type, frame) 87 int type; 88 struct frame frame; 89 { 90 u_long osp, nsp; 91 u_int fsize, s; 92 extern short exframesize[]; 93 94 /* 95 * After a kernel mode trap, the saved sp doesn't point to the right 96 * place. The correct value is the top of the frame (i.e. before the 97 * KGDB trap). 98 * 99 * XXX this may have to change if we implement an interrupt stack. 100 */ 101 fsize = sizeof(frame) - sizeof(frame.F_u) + exframesize[frame.f_format]; 102 frame.f_regs[SP] = (u_long)&frame + fsize; 103 104 /* 105 * Copy the interrupt context and frame to the new stack. 106 * We're throwing away trap()'s frame since we're going to do 107 * our own rte. 108 */ 109 nsp = (u_long)&kgdb_stack[KGDB_STACKWORDS] - 110 roundup(fsize, sizeof(u_long)); 111 112 copywords((u_long *)&frame, (u_long *)nsp, fsize); 113 114 s = splhigh(); 115 116 getsp(osp); 117 setsp(nsp); 118 119 if (kgdb_trap(type, (struct frame *)nsp) == 0) { 120 /* 121 * Get back on kernel stack. This thread of control 122 * will return back up through trap(). If kgdb_trap() 123 * returns 0, it didn't handle the trap at all so 124 * the stack is still intact and everything will 125 * unwind okay from here up. 126 */ 127 setsp(osp); 128 splx(s); 129 return 0; 130 } 131 /* 132 * Copy back context, which has possibly changed. Even the 133 * sp might have changed. 134 */ 135 osp = ((struct frame *)nsp)->f_regs[SP] - fsize; 136 copywords((u_long *)nsp, (u_long *)osp, fsize); 137 setsp(osp); 138 139 /* 140 * Restore the possible new context from frame, pop the 141 * unneeded usp (we trapped from kernel mode) and pad word, 142 * and return to the trapped thread. 143 */ 144 asm("moveml %sp@+,#0x7FFF; addql #8,sp; rte"); 145 } 146 147 int kgdb_testval; 148 149 kgdb_test(i) 150 int i; 151 { 152 ++kgdb_testval; 153 return (i + 1); 154 } 155 #endif /* KGDB */ 156