xref: /netbsd-src/sys/arch/arm/arm32/kgdb_machdep.c (revision 413d532bcc3f62d122e56d92e13ac64825a40baf)
1 /*	$NetBSD: kgdb_machdep.c,v 1.7 2009/10/18 18:14:00 snj Exp $	*/
2 
3 /*
4  * Copyright (c) 1996 Matthias Pfaller.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: kgdb_machdep.c,v 1.7 2009/10/18 18:14:00 snj Exp $");
30 
31 #include "opt_ddb.h"
32 #include "opt_kgdb.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kgdb.h>
37 
38 #include <uvm/uvm_extern.h>
39 
40 #include <machine/frame.h>
41 #include <machine/reg.h>
42 #include <machine/trap.h>
43 
44 /*
45  * Determine if the memory at va..(va+len) is valid.
46  */
47 int
48 kgdb_acc(vaddr_t va, size_t len)
49 {
50 	vaddr_t last_va;
51 
52 	last_va = va + len;
53 	va  &= ~PGOFSET;
54 	last_va &= ~PGOFSET;
55 
56 	do {
57 		if (db_validate_address(va))
58 			return (0);
59 		va  += PAGE_SIZE;
60 	} while (va < last_va);
61 
62 	return (1);
63 }
64 
65 /*
66  * Translate a trap number into a unix compatible signal value.
67  * (gdb only understands unix signal numbers).
68  */
69 int
70 kgdb_signal(int type)
71 {
72 
73 	switch (type) {
74 	case T_BREAKPOINT:
75 		return(SIGTRAP);
76 	case -1:
77 		return(SIGSEGV);
78 	default:
79 		return(SIGINT);
80 	}
81 }
82 
83 /*
84  * Definitions exported from gdb.
85  */
86 
87 /*
88  * Translate the values stored in the kernel regs struct to the format
89  * understood by gdb.
90  */
91 void
92 kgdb_getregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
93 {
94 
95 	gdb_regs[KGDB_REGNUM_R0 +  0] = regs->tf_r0;
96 	gdb_regs[KGDB_REGNUM_R0 +  1] = regs->tf_r1;
97 	gdb_regs[KGDB_REGNUM_R0 +  2] = regs->tf_r2;
98 	gdb_regs[KGDB_REGNUM_R0 +  3] = regs->tf_r3;
99 	gdb_regs[KGDB_REGNUM_R0 +  4] = regs->tf_r4;
100 	gdb_regs[KGDB_REGNUM_R0 +  5] = regs->tf_r5;
101 	gdb_regs[KGDB_REGNUM_R0 +  6] = regs->tf_r6;
102 	gdb_regs[KGDB_REGNUM_R0 +  7] = regs->tf_r7;
103 	gdb_regs[KGDB_REGNUM_R0 +  8] = regs->tf_r8;
104 	gdb_regs[KGDB_REGNUM_R0 +  9] = regs->tf_r9;
105 	gdb_regs[KGDB_REGNUM_R0 + 10] = regs->tf_r10;
106 	gdb_regs[KGDB_REGNUM_R0 + 11] = regs->tf_r11;
107 	gdb_regs[KGDB_REGNUM_R0 + 12] = regs->tf_r12;
108 	gdb_regs[KGDB_REGNUM_R0 + 13] = regs->tf_svc_sp;
109 	gdb_regs[KGDB_REGNUM_R0 + 14] = regs->tf_svc_lr;
110 	gdb_regs[KGDB_REGNUM_R0 + 15] = regs->tf_pc;
111 
112 	gdb_regs[KGDB_REGNUM_SPSR] = regs->tf_spsr;
113 }
114 
115 /*
116  * Reverse the above.
117  */
118 void
119 kgdb_setregs(db_regs_t *regs, kgdb_reg_t *gdb_regs)
120 {
121 	regs->tf_r0     = gdb_regs[KGDB_REGNUM_R0 +  0];
122 	regs->tf_r1     = gdb_regs[KGDB_REGNUM_R0 +  1];
123 	regs->tf_r2     = gdb_regs[KGDB_REGNUM_R0 +  2];
124 	regs->tf_r3     = gdb_regs[KGDB_REGNUM_R0 +  3];
125 	regs->tf_r4     = gdb_regs[KGDB_REGNUM_R0 +  4];
126 	regs->tf_r5     = gdb_regs[KGDB_REGNUM_R0 +  5];
127 	regs->tf_r6     = gdb_regs[KGDB_REGNUM_R0 +  6];
128 	regs->tf_r7     = gdb_regs[KGDB_REGNUM_R0 +  7];
129 	regs->tf_r8     = gdb_regs[KGDB_REGNUM_R0 +  8];
130 	regs->tf_r9     = gdb_regs[KGDB_REGNUM_R0 +  9];
131 	regs->tf_r10    = gdb_regs[KGDB_REGNUM_R0 + 10];
132 	regs->tf_r11    = gdb_regs[KGDB_REGNUM_R0 + 11];
133 	regs->tf_r12    = gdb_regs[KGDB_REGNUM_R0 + 12];
134 	regs->tf_svc_sp = gdb_regs[KGDB_REGNUM_R0 + 13];
135 	regs->tf_svc_lr = gdb_regs[KGDB_REGNUM_R0 + 14];
136 	regs->tf_pc     = gdb_regs[KGDB_REGNUM_R0 + 15];
137 
138 	regs->tf_spsr = gdb_regs[KGDB_REGNUM_SPSR];
139 }
140 
141 /*
142  * Trap into kgdb to wait for debugger to connect,
143  * noting on the console why nothing else is going on.
144  */
145 void
146 kgdb_connect(int verbose)
147 {
148 
149 	if (kgdb_dev == NODEV)
150 		return;
151 
152 	if (verbose)
153 		printf("kgdb waiting...");
154 
155 	__asm volatile(KBPT_ASM);
156 
157 	if (verbose)
158 		printf("connected.\n");
159 
160 	kgdb_debug_panic = 1;
161 }
162 
163 /*
164  * Decide what to do on panic.
165  * (This is called by panic, like Debugger())
166  */
167 void
168 kgdb_panic(void)
169 {
170 
171 	if (kgdb_dev != NODEV && kgdb_debug_panic) {
172 		printf("entering kgdb\n");
173 		kgdb_connect(kgdb_active == 0);
174 	}
175 }
176