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68f5f838 SL |
1 | /* GNU/Linux/Nios II specific low level interface, for the remote server for |
2 | GDB. | |
b811d2c2 | 3 | Copyright (C) 2008-2020 Free Software Foundation, Inc. |
68f5f838 SL |
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" | |
21e94bd9 | 24 | #include "elf/common.h" |
5826e159 | 25 | #include "nat/gdb_ptrace.h" |
68f5f838 SL |
26 | #include <endian.h> |
27 | #include "gdb_proc_service.h" | |
28 | #include <asm/ptrace.h> | |
29 | ||
30 | #ifndef PTRACE_GET_THREAD_AREA | |
31 | #define PTRACE_GET_THREAD_AREA 25 | |
32 | #endif | |
33 | ||
ef0478f6 TBA |
34 | /* Linux target op definitions for the NIOS II architecture. */ |
35 | ||
36 | class nios2_target : public linux_process_target | |
37 | { | |
38 | public: | |
39 | ||
aa8d21c9 TBA |
40 | const regs_info *get_regs_info () override; |
41 | ||
3ca4edb6 TBA |
42 | const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override; |
43 | ||
797bcff5 TBA |
44 | protected: |
45 | ||
46 | void low_arch_setup () override; | |
daca57a7 TBA |
47 | |
48 | bool low_cannot_fetch_register (int regno) override; | |
49 | ||
50 | bool low_cannot_store_register (int regno) override; | |
bf9ae9d8 TBA |
51 | |
52 | bool low_supports_breakpoints () override; | |
53 | ||
54 | CORE_ADDR low_get_pc (regcache *regcache) override; | |
55 | ||
56 | void low_set_pc (regcache *regcache, CORE_ADDR newpc) override; | |
ef0478f6 TBA |
57 | }; |
58 | ||
59 | /* The singleton target ops object. */ | |
60 | ||
61 | static nios2_target the_nios2_target; | |
62 | ||
bf9ae9d8 TBA |
63 | bool |
64 | nios2_target::low_supports_breakpoints () | |
65 | { | |
66 | return true; | |
67 | } | |
68 | ||
69 | CORE_ADDR | |
70 | nios2_target::low_get_pc (regcache *regcache) | |
71 | { | |
72 | return linux_get_pc_32bit (regcache); | |
73 | } | |
74 | ||
75 | void | |
76 | nios2_target::low_set_pc (regcache *regcache, CORE_ADDR pc) | |
77 | { | |
78 | linux_set_pc_32bit (regcache, pc); | |
79 | } | |
80 | ||
68f5f838 SL |
81 | /* The following definition must agree with the number of registers |
82 | defined in "struct user_regs" in GLIBC | |
21e94bd9 | 83 | (sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with |
68f5f838 SL |
84 | NIOS2_NUM_REGS in GDB proper. */ |
85 | ||
86 | #define nios2_num_regs 49 | |
87 | ||
88 | /* Defined in auto-generated file nios2-linux.c. */ | |
89 | ||
90 | void init_registers_nios2_linux (void); | |
3aee8918 | 91 | extern const struct target_desc *tdesc_nios2_linux; |
68f5f838 SL |
92 | |
93 | /* This union is used to convert between int and byte buffer | |
94 | representations of register contents. */ | |
95 | ||
96 | union nios2_register | |
97 | { | |
98 | unsigned char buf[4]; | |
99 | int reg32; | |
100 | }; | |
101 | ||
102 | /* Return the ptrace ``address'' of register REGNO. */ | |
103 | ||
104 | static int nios2_regmap[] = { | |
105 | -1, 1, 2, 3, 4, 5, 6, 7, | |
106 | 8, 9, 10, 11, 12, 13, 14, 15, | |
107 | 16, 17, 18, 19, 20, 21, 22, 23, | |
108 | 24, 25, 26, 27, 28, 29, 30, 31, | |
109 | 32, 33, 34, 35, 36, 37, 38, 39, | |
110 | 40, 41, 42, 43, 44, 45, 46, 47, | |
111 | 48, | |
112 | 0 | |
113 | }; | |
114 | ||
797bcff5 | 115 | /* Implement the low_arch_setup linux target ops method. */ |
68f5f838 | 116 | |
797bcff5 TBA |
117 | void |
118 | nios2_target::low_arch_setup () | |
68f5f838 | 119 | { |
3aee8918 | 120 | current_process ()->tdesc = tdesc_nios2_linux; |
68f5f838 SL |
121 | } |
122 | ||
daca57a7 | 123 | /* Implement the low_cannot_fetch_register linux target ops method. */ |
68f5f838 | 124 | |
daca57a7 TBA |
125 | bool |
126 | nios2_target::low_cannot_fetch_register (int regno) | |
68f5f838 | 127 | { |
daca57a7 | 128 | return (nios2_regmap[regno] == -1); |
68f5f838 SL |
129 | } |
130 | ||
daca57a7 | 131 | /* Implement the low_cannot_store_register linux target ops method. */ |
68f5f838 | 132 | |
daca57a7 TBA |
133 | bool |
134 | nios2_target::low_cannot_store_register (int regno) | |
68f5f838 | 135 | { |
daca57a7 | 136 | return (nios2_regmap[regno] == -1); |
68f5f838 SL |
137 | } |
138 | ||
af60a1ef SL |
139 | /* Breakpoint support. Also see comments on nios2_breakpoint_from_pc |
140 | in nios2-tdep.c. */ | |
141 | ||
142 | #if defined(__nios2_arch__) && __nios2_arch__ == 2 | |
143 | #define NIOS2_BREAKPOINT 0xb7fd0020 | |
144 | #define CDX_BREAKPOINT 0xd7c9 | |
145 | #else | |
146 | #define NIOS2_BREAKPOINT 0x003b6ffa | |
147 | #endif | |
68f5f838 | 148 | |
dd373349 AT |
149 | /* We only register the 4-byte breakpoint, even on R2 targets which also |
150 | support 2-byte breakpoints. Since there is no supports_z_point_type | |
151 | function provided, gdbserver never inserts software breakpoints itself | |
152 | and instead relies on GDB to insert the breakpoint of the correct length | |
153 | via a memory write. */ | |
af60a1ef | 154 | static const unsigned int nios2_breakpoint = NIOS2_BREAKPOINT; |
68f5f838 SL |
155 | #define nios2_breakpoint_len 4 |
156 | ||
3ca4edb6 | 157 | /* Implementation of target ops method "sw_breakpoint_from_kind". */ |
dd373349 | 158 | |
3ca4edb6 TBA |
159 | const gdb_byte * |
160 | nios2_target::sw_breakpoint_from_kind (int kind, int *size) | |
dd373349 AT |
161 | { |
162 | *size = nios2_breakpoint_len; | |
163 | return (const gdb_byte *) &nios2_breakpoint; | |
164 | } | |
165 | ||
68f5f838 SL |
166 | /* Implement the breakpoint_at linux_target_ops method. */ |
167 | ||
168 | static int | |
169 | nios2_breakpoint_at (CORE_ADDR where) | |
170 | { | |
171 | unsigned int insn; | |
172 | ||
af60a1ef SL |
173 | /* For R2, first check for the 2-byte CDX trap.n breakpoint encoding. */ |
174 | #if defined(__nios2_arch__) && __nios2_arch__ == 2 | |
52405d85 | 175 | the_target->read_memory (where, (unsigned char *) &insn, 2); |
af60a1ef SL |
176 | if (insn == CDX_BREAKPOINT) |
177 | return 1; | |
178 | #endif | |
179 | ||
52405d85 | 180 | the_target->read_memory (where, (unsigned char *) &insn, 4); |
68f5f838 SL |
181 | if (insn == nios2_breakpoint) |
182 | return 1; | |
183 | return 0; | |
184 | } | |
185 | ||
186 | /* Fetch the thread-local storage pointer for libthread_db. */ | |
187 | ||
188 | ps_err_e | |
754653a7 | 189 | ps_get_thread_area (struct ps_prochandle *ph, |
68f5f838 SL |
190 | lwpid_t lwpid, int idx, void **base) |
191 | { | |
192 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) | |
193 | return PS_ERR; | |
194 | ||
195 | /* IDX is the bias from the thread pointer to the beginning of the | |
196 | thread descriptor. It has to be subtracted due to implementation | |
197 | quirks in libthread_db. */ | |
198 | *base = (void *) ((char *) *base - idx); | |
199 | ||
200 | return PS_OK; | |
201 | } | |
202 | ||
68f5f838 SL |
203 | /* Helper functions to collect/supply a single register REGNO. */ |
204 | ||
205 | static void | |
206 | nios2_collect_register (struct regcache *regcache, int regno, | |
207 | union nios2_register *reg) | |
208 | { | |
209 | union nios2_register tmp_reg; | |
210 | ||
211 | collect_register (regcache, regno, &tmp_reg.reg32); | |
212 | reg->reg32 = tmp_reg.reg32; | |
213 | } | |
214 | ||
215 | static void | |
216 | nios2_supply_register (struct regcache *regcache, int regno, | |
217 | const union nios2_register *reg) | |
218 | { | |
219 | supply_register (regcache, regno, reg->buf); | |
220 | } | |
221 | ||
222 | /* We have only a single register set on Nios II. */ | |
223 | ||
224 | static void | |
225 | nios2_fill_gregset (struct regcache *regcache, void *buf) | |
226 | { | |
b1c51e36 | 227 | union nios2_register *regset = (union nios2_register *) buf; |
68f5f838 SL |
228 | int i; |
229 | ||
230 | for (i = 1; i < nios2_num_regs; i++) | |
231 | nios2_collect_register (regcache, i, regset + i); | |
232 | } | |
233 | ||
234 | static void | |
235 | nios2_store_gregset (struct regcache *regcache, const void *buf) | |
236 | { | |
b1c51e36 | 237 | const union nios2_register *regset = (union nios2_register *) buf; |
68f5f838 SL |
238 | int i; |
239 | ||
240 | for (i = 0; i < nios2_num_regs; i++) | |
241 | nios2_supply_register (regcache, i, regset + i); | |
242 | } | |
68f5f838 | 243 | |
3aee8918 | 244 | static struct regset_info nios2_regsets[] = |
68f5f838 | 245 | { |
21e94bd9 SL |
246 | { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, |
247 | nios2_num_regs * 4, GENERAL_REGS, | |
68f5f838 | 248 | nios2_fill_gregset, nios2_store_gregset }, |
50bc912a | 249 | NULL_REGSET |
68f5f838 SL |
250 | }; |
251 | ||
3aee8918 PA |
252 | static struct regsets_info nios2_regsets_info = |
253 | { | |
254 | nios2_regsets, /* regsets */ | |
255 | 0, /* num_regsets */ | |
256 | NULL, /* disabled_regsets */ | |
257 | }; | |
258 | ||
259 | static struct usrregs_info nios2_usrregs_info = | |
260 | { | |
261 | nios2_num_regs, | |
262 | nios2_regmap, | |
263 | }; | |
264 | ||
aa8d21c9 | 265 | static struct regs_info myregs_info = |
3aee8918 PA |
266 | { |
267 | NULL, /* regset_bitmap */ | |
268 | &nios2_usrregs_info, | |
269 | &nios2_regsets_info | |
270 | }; | |
271 | ||
aa8d21c9 TBA |
272 | const regs_info * |
273 | nios2_target::get_regs_info () | |
3aee8918 | 274 | { |
aa8d21c9 | 275 | return &myregs_info; |
3aee8918 PA |
276 | } |
277 | ||
68f5f838 SL |
278 | struct linux_target_ops the_low_target = |
279 | { | |
fa5308bd | 280 | NULL, /* get_next_pcs */ |
68f5f838 SL |
281 | 0, |
282 | nios2_breakpoint_at, | |
283 | }; | |
3aee8918 | 284 | |
ef0478f6 TBA |
285 | /* The linux target ops object. */ |
286 | ||
287 | linux_process_target *the_linux_target = &the_nios2_target; | |
288 | ||
3aee8918 PA |
289 | void |
290 | initialize_low_arch (void) | |
291 | { | |
292 | init_registers_nios2_linux (); | |
293 | ||
294 | initialize_regsets_info (&nios2_regsets_info); | |
295 | } |