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authorJason Wessel <jason.wessel@windriver.com>2008-02-20 14:33:40 -0500
committerJason Wessel <jason.wessel@windriver.com>2008-07-23 12:30:15 -0400
commit5cbad0ebf45c5417104b383dc0e34f64fa7f2473 (patch)
treebc6203084fa7cd810227f6b2632f7c4655d17ecf /arch/arm/kernel/kgdb.c
parent68afab1cb31436fc9b256a5f44771fa58ed019e2 (diff)
kgdb: support for ARCH=arm
This patch adds the ARCH=arm specific a kgdb backend, originally written by Deepak Saxena <dsaxena@plexity.net> and George Davis <gdavis@mvista.com>. Geoff Levand <geoffrey.levand@am.sony.com>, Nicolas Pitre, Manish Lachwani, and Jason Wessel have contributed various fixups here as well. The KGDB patch makes one change to the core ARM architecture such that the traps are initialized early for use with the debugger or other subsystems. [ mingo@elte.hu: small cleanups. ] [ ben-linux@fluff.org: fixed early_trap_init ] Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Deepak Saxena <dsaxena@plexity.net>
Diffstat (limited to 'arch/arm/kernel/kgdb.c')
-rw-r--r--arch/arm/kernel/kgdb.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
new file mode 100644
index 000000000000..aaffaecffcd1
--- /dev/null
+++ b/arch/arm/kernel/kgdb.c
@@ -0,0 +1,201 @@
1/*
2 * arch/arm/kernel/kgdb.c
3 *
4 * ARM KGDB support
5 *
6 * Copyright (c) 2002-2004 MontaVista Software, Inc
7 * Copyright (c) 2008 Wind River Systems, Inc.
8 *
9 * Authors: George Davis <davis_g@mvista.com>
10 * Deepak Saxena <dsaxena@plexity.net>
11 */
12#include <linux/kgdb.h>
13#include <asm/traps.h>
14
15/* Make a local copy of the registers passed into the handler (bletch) */
16void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
17{
18 int regno;
19
20 /* Initialize all to zero. */
21 for (regno = 0; regno < GDB_MAX_REGS; regno++)
22 gdb_regs[regno] = 0;
23
24 gdb_regs[_R0] = kernel_regs->ARM_r0;
25 gdb_regs[_R1] = kernel_regs->ARM_r1;
26 gdb_regs[_R2] = kernel_regs->ARM_r2;
27 gdb_regs[_R3] = kernel_regs->ARM_r3;
28 gdb_regs[_R4] = kernel_regs->ARM_r4;
29 gdb_regs[_R5] = kernel_regs->ARM_r5;
30 gdb_regs[_R6] = kernel_regs->ARM_r6;
31 gdb_regs[_R7] = kernel_regs->ARM_r7;
32 gdb_regs[_R8] = kernel_regs->ARM_r8;
33 gdb_regs[_R9] = kernel_regs->ARM_r9;
34 gdb_regs[_R10] = kernel_regs->ARM_r10;
35 gdb_regs[_FP] = kernel_regs->ARM_fp;
36 gdb_regs[_IP] = kernel_regs->ARM_ip;
37 gdb_regs[_SPT] = kernel_regs->ARM_sp;
38 gdb_regs[_LR] = kernel_regs->ARM_lr;
39 gdb_regs[_PC] = kernel_regs->ARM_pc;
40 gdb_regs[_CPSR] = kernel_regs->ARM_cpsr;
41}
42
43/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
44void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
45{
46 kernel_regs->ARM_r0 = gdb_regs[_R0];
47 kernel_regs->ARM_r1 = gdb_regs[_R1];
48 kernel_regs->ARM_r2 = gdb_regs[_R2];
49 kernel_regs->ARM_r3 = gdb_regs[_R3];
50 kernel_regs->ARM_r4 = gdb_regs[_R4];
51 kernel_regs->ARM_r5 = gdb_regs[_R5];
52 kernel_regs->ARM_r6 = gdb_regs[_R6];
53 kernel_regs->ARM_r7 = gdb_regs[_R7];
54 kernel_regs->ARM_r8 = gdb_regs[_R8];
55 kernel_regs->ARM_r9 = gdb_regs[_R9];
56 kernel_regs->ARM_r10 = gdb_regs[_R10];
57 kernel_regs->ARM_fp = gdb_regs[_FP];
58 kernel_regs->ARM_ip = gdb_regs[_IP];
59 kernel_regs->ARM_sp = gdb_regs[_SPT];
60 kernel_regs->ARM_lr = gdb_regs[_LR];
61 kernel_regs->ARM_pc = gdb_regs[_PC];
62 kernel_regs->ARM_cpsr = gdb_regs[_CPSR];
63}
64
65void
66sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
67{
68 struct pt_regs *thread_regs;
69 int regno;
70
71 /* Just making sure... */
72 if (task == NULL)
73 return;
74
75 /* Initialize to zero */
76 for (regno = 0; regno < GDB_MAX_REGS; regno++)
77 gdb_regs[regno] = 0;
78
79 /* Otherwise, we have only some registers from switch_to() */
80 thread_regs = task_pt_regs(task);
81 gdb_regs[_R0] = thread_regs->ARM_r0;
82 gdb_regs[_R1] = thread_regs->ARM_r1;
83 gdb_regs[_R2] = thread_regs->ARM_r2;
84 gdb_regs[_R3] = thread_regs->ARM_r3;
85 gdb_regs[_R4] = thread_regs->ARM_r4;
86 gdb_regs[_R5] = thread_regs->ARM_r5;
87 gdb_regs[_R6] = thread_regs->ARM_r6;
88 gdb_regs[_R7] = thread_regs->ARM_r7;
89 gdb_regs[_R8] = thread_regs->ARM_r8;
90 gdb_regs[_R9] = thread_regs->ARM_r9;
91 gdb_regs[_R10] = thread_regs->ARM_r10;
92 gdb_regs[_FP] = thread_regs->ARM_fp;
93 gdb_regs[_IP] = thread_regs->ARM_ip;
94 gdb_regs[_SPT] = thread_regs->ARM_sp;
95 gdb_regs[_LR] = thread_regs->ARM_lr;
96 gdb_regs[_PC] = thread_regs->ARM_pc;
97 gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
98}
99
100static int compiled_break;
101
102int kgdb_arch_handle_exception(int exception_vector, int signo,
103 int err_code, char *remcom_in_buffer,
104 char *remcom_out_buffer,
105 struct pt_regs *linux_regs)
106{
107 unsigned long addr;
108 char *ptr;
109
110 switch (remcom_in_buffer[0]) {
111 case 'D':
112 case 'k':
113 case 'c':
114 kgdb_contthread = NULL;
115
116 /*
117 * Try to read optional parameter, pc unchanged if no parm.
118 * If this was a compiled breakpoint, we need to move
119 * to the next instruction or we will just breakpoint
120 * over and over again.
121 */
122 ptr = &remcom_in_buffer[1];
123 if (kgdb_hex2long(&ptr, &addr))
124 linux_regs->ARM_pc = addr;
125 else if (compiled_break == 1)
126 linux_regs->ARM_pc += 4;
127
128 compiled_break = 0;
129
130 return 0;
131 }
132
133 return -1;
134}
135
136static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
137{
138 kgdb_handle_exception(1, SIGTRAP, 0, regs);
139
140 return 0;
141}
142
143static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
144{
145 compiled_break = 1;
146 kgdb_handle_exception(1, SIGTRAP, 0, regs);
147
148 return 0;
149}
150
151static struct undef_hook kgdb_brkpt_hook = {
152 .instr_mask = 0xffffffff,
153 .instr_val = KGDB_BREAKINST,
154 .fn = kgdb_brk_fn
155};
156
157static struct undef_hook kgdb_compiled_brkpt_hook = {
158 .instr_mask = 0xffffffff,
159 .instr_val = KGDB_COMPILED_BREAK,
160 .fn = kgdb_compiled_brk_fn
161};
162
163/**
164 * kgdb_arch_init - Perform any architecture specific initalization.
165 *
166 * This function will handle the initalization of any architecture
167 * specific callbacks.
168 */
169int kgdb_arch_init(void)
170{
171 register_undef_hook(&kgdb_brkpt_hook);
172 register_undef_hook(&kgdb_compiled_brkpt_hook);
173
174 return 0;
175}
176
177/**
178 * kgdb_arch_exit - Perform any architecture specific uninitalization.
179 *
180 * This function will handle the uninitalization of any architecture
181 * specific callbacks, for dynamic registration and unregistration.
182 */
183void kgdb_arch_exit(void)
184{
185 unregister_undef_hook(&kgdb_brkpt_hook);
186 unregister_undef_hook(&kgdb_compiled_brkpt_hook);
187}
188
189/*
190 * Register our undef instruction hooks with ARM undef core.
191 * We regsiter a hook specifically looking for the KGB break inst
192 * and we handle the normal undef case within the do_undefinstr
193 * handler.
194 */
195struct kgdb_arch arch_kgdb_ops = {
196#ifndef __ARMEB__
197 .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
198#else /* ! __ARMEB__ */
199 .gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
200#endif
201};