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68f5f838 SL |
1 | /* GNU/Linux/Nios II specific low level interface, for the remote server for |
2 | GDB. | |
3 | Copyright (C) 2008-2013 Free Software Foundation, Inc. | |
4 | ||
5 | Contributed by Mentor Graphics, Inc. | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | #include "server.h" | |
23 | #include "linux-low.h" | |
24 | #include <sys/ptrace.h> | |
25 | #include <endian.h> | |
26 | #include "gdb_proc_service.h" | |
27 | #include <asm/ptrace.h> | |
28 | ||
29 | #ifndef PTRACE_GET_THREAD_AREA | |
30 | #define PTRACE_GET_THREAD_AREA 25 | |
31 | #endif | |
32 | ||
33 | /* The following definition must agree with the number of registers | |
34 | defined in "struct user_regs" in GLIBC | |
35 | (ports/sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with | |
36 | NIOS2_NUM_REGS in GDB proper. */ | |
37 | ||
38 | #define nios2_num_regs 49 | |
39 | ||
40 | /* Defined in auto-generated file nios2-linux.c. */ | |
41 | ||
42 | void init_registers_nios2_linux (void); | |
43 | ||
44 | /* This union is used to convert between int and byte buffer | |
45 | representations of register contents. */ | |
46 | ||
47 | union nios2_register | |
48 | { | |
49 | unsigned char buf[4]; | |
50 | int reg32; | |
51 | }; | |
52 | ||
53 | /* Return the ptrace ``address'' of register REGNO. */ | |
54 | ||
55 | static int nios2_regmap[] = { | |
56 | -1, 1, 2, 3, 4, 5, 6, 7, | |
57 | 8, 9, 10, 11, 12, 13, 14, 15, | |
58 | 16, 17, 18, 19, 20, 21, 22, 23, | |
59 | 24, 25, 26, 27, 28, 29, 30, 31, | |
60 | 32, 33, 34, 35, 36, 37, 38, 39, | |
61 | 40, 41, 42, 43, 44, 45, 46, 47, | |
62 | 48, | |
63 | 0 | |
64 | }; | |
65 | ||
66 | /* Implement the arch_setup linux_target_ops method. */ | |
67 | ||
68 | static void | |
69 | nios2_arch_setup (void) | |
70 | { | |
71 | init_registers_nios2_linux (); | |
72 | } | |
73 | ||
74 | /* Implement the cannot_fetch_register linux_target_ops method. */ | |
75 | ||
76 | static int | |
77 | nios2_cannot_fetch_register (int regno) | |
78 | { | |
79 | if (nios2_regmap[regno] == -1) | |
80 | return 1; | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | /* Implement the cannot_store_register linux_target_ops method. */ | |
86 | ||
87 | static int | |
88 | nios2_cannot_store_register (int regno) | |
89 | { | |
90 | if (nios2_regmap[regno] == -1) | |
91 | return 1; | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
96 | /* Implement the get_pc linux_target_ops method. */ | |
97 | ||
98 | static CORE_ADDR | |
99 | nios2_get_pc (struct regcache *regcache) | |
100 | { | |
101 | union nios2_register pc; | |
102 | ||
103 | collect_register_by_name (regcache, "pc", pc.buf); | |
104 | return pc.reg32; | |
105 | } | |
106 | ||
107 | /* Implement the set_pc linux_target_ops method. */ | |
108 | ||
109 | static void | |
110 | nios2_set_pc (struct regcache *regcache, CORE_ADDR pc) | |
111 | { | |
112 | union nios2_register newpc; | |
113 | ||
114 | newpc.reg32 = pc; | |
115 | supply_register_by_name (regcache, "pc", newpc.buf); | |
116 | } | |
117 | ||
118 | /* Breakpoint support. */ | |
119 | ||
120 | static const unsigned int nios2_breakpoint = 0x003b6ffa; | |
121 | #define nios2_breakpoint_len 4 | |
122 | ||
123 | /* Implement the breakpoint_reinsert_addr linux_target_ops method. */ | |
124 | ||
125 | static CORE_ADDR | |
126 | nios2_reinsert_addr (void) | |
127 | { | |
128 | union nios2_register ra; | |
129 | struct regcache *regcache = get_thread_regcache (current_inferior, 1); | |
130 | ||
131 | collect_register_by_name (regcache, "ra", ra.buf); | |
132 | return ra.reg32; | |
133 | } | |
134 | ||
135 | /* Implement the breakpoint_at linux_target_ops method. */ | |
136 | ||
137 | static int | |
138 | nios2_breakpoint_at (CORE_ADDR where) | |
139 | { | |
140 | unsigned int insn; | |
141 | ||
142 | (*the_target->read_memory) (where, (unsigned char *) &insn, 4); | |
143 | if (insn == nios2_breakpoint) | |
144 | return 1; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | /* Fetch the thread-local storage pointer for libthread_db. */ | |
149 | ||
150 | ps_err_e | |
151 | ps_get_thread_area (const struct ps_prochandle *ph, | |
152 | lwpid_t lwpid, int idx, void **base) | |
153 | { | |
154 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) | |
155 | return PS_ERR; | |
156 | ||
157 | /* IDX is the bias from the thread pointer to the beginning of the | |
158 | thread descriptor. It has to be subtracted due to implementation | |
159 | quirks in libthread_db. */ | |
160 | *base = (void *) ((char *) *base - idx); | |
161 | ||
162 | return PS_OK; | |
163 | } | |
164 | ||
165 | #ifdef HAVE_PTRACE_GETREGS | |
166 | ||
167 | /* Helper functions to collect/supply a single register REGNO. */ | |
168 | ||
169 | static void | |
170 | nios2_collect_register (struct regcache *regcache, int regno, | |
171 | union nios2_register *reg) | |
172 | { | |
173 | union nios2_register tmp_reg; | |
174 | ||
175 | collect_register (regcache, regno, &tmp_reg.reg32); | |
176 | reg->reg32 = tmp_reg.reg32; | |
177 | } | |
178 | ||
179 | static void | |
180 | nios2_supply_register (struct regcache *regcache, int regno, | |
181 | const union nios2_register *reg) | |
182 | { | |
183 | supply_register (regcache, regno, reg->buf); | |
184 | } | |
185 | ||
186 | /* We have only a single register set on Nios II. */ | |
187 | ||
188 | static void | |
189 | nios2_fill_gregset (struct regcache *regcache, void *buf) | |
190 | { | |
191 | union nios2_register *regset = buf; | |
192 | int i; | |
193 | ||
194 | for (i = 1; i < nios2_num_regs; i++) | |
195 | nios2_collect_register (regcache, i, regset + i); | |
196 | } | |
197 | ||
198 | static void | |
199 | nios2_store_gregset (struct regcache *regcache, const void *buf) | |
200 | { | |
201 | const union nios2_register *regset = buf; | |
202 | int i; | |
203 | ||
204 | for (i = 0; i < nios2_num_regs; i++) | |
205 | nios2_supply_register (regcache, i, regset + i); | |
206 | } | |
207 | #endif /* HAVE_PTRACE_GETREGS */ | |
208 | ||
209 | struct regset_info target_regsets[] = | |
210 | { | |
211 | #ifdef HAVE_PTRACE_GETREGS | |
212 | { PTRACE_GETREGS, PTRACE_SETREGS, 0, nios2_num_regs * 4, GENERAL_REGS, | |
213 | nios2_fill_gregset, nios2_store_gregset }, | |
214 | #endif /* HAVE_PTRACE_GETREGS */ | |
215 | { 0, 0, 0, -1, -1, NULL, NULL } | |
216 | }; | |
217 | ||
218 | struct linux_target_ops the_low_target = | |
219 | { | |
220 | nios2_arch_setup, | |
221 | nios2_num_regs, | |
222 | nios2_regmap, | |
223 | NULL, | |
224 | nios2_cannot_fetch_register, | |
225 | nios2_cannot_store_register, | |
226 | NULL, | |
227 | nios2_get_pc, | |
228 | nios2_set_pc, | |
229 | (const unsigned char *) &nios2_breakpoint, | |
230 | nios2_breakpoint_len, | |
231 | nios2_reinsert_addr, | |
232 | 0, | |
233 | nios2_breakpoint_at, | |
234 | }; |