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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; | |
d7146cda TBA |
57 | |
58 | bool low_breakpoint_at (CORE_ADDR pc) override; | |
ef0478f6 TBA |
59 | }; |
60 | ||
61 | /* The singleton target ops object. */ | |
62 | ||
63 | static nios2_target the_nios2_target; | |
64 | ||
bf9ae9d8 TBA |
65 | bool |
66 | nios2_target::low_supports_breakpoints () | |
67 | { | |
68 | return true; | |
69 | } | |
70 | ||
71 | CORE_ADDR | |
72 | nios2_target::low_get_pc (regcache *regcache) | |
73 | { | |
74 | return linux_get_pc_32bit (regcache); | |
75 | } | |
76 | ||
77 | void | |
78 | nios2_target::low_set_pc (regcache *regcache, CORE_ADDR pc) | |
79 | { | |
80 | linux_set_pc_32bit (regcache, pc); | |
81 | } | |
82 | ||
68f5f838 SL |
83 | /* The following definition must agree with the number of registers |
84 | defined in "struct user_regs" in GLIBC | |
21e94bd9 | 85 | (sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with |
68f5f838 SL |
86 | NIOS2_NUM_REGS in GDB proper. */ |
87 | ||
88 | #define nios2_num_regs 49 | |
89 | ||
90 | /* Defined in auto-generated file nios2-linux.c. */ | |
91 | ||
92 | void init_registers_nios2_linux (void); | |
3aee8918 | 93 | extern const struct target_desc *tdesc_nios2_linux; |
68f5f838 SL |
94 | |
95 | /* This union is used to convert between int and byte buffer | |
96 | representations of register contents. */ | |
97 | ||
98 | union nios2_register | |
99 | { | |
100 | unsigned char buf[4]; | |
101 | int reg32; | |
102 | }; | |
103 | ||
104 | /* Return the ptrace ``address'' of register REGNO. */ | |
105 | ||
106 | static int nios2_regmap[] = { | |
107 | -1, 1, 2, 3, 4, 5, 6, 7, | |
108 | 8, 9, 10, 11, 12, 13, 14, 15, | |
109 | 16, 17, 18, 19, 20, 21, 22, 23, | |
110 | 24, 25, 26, 27, 28, 29, 30, 31, | |
111 | 32, 33, 34, 35, 36, 37, 38, 39, | |
112 | 40, 41, 42, 43, 44, 45, 46, 47, | |
113 | 48, | |
114 | 0 | |
115 | }; | |
116 | ||
797bcff5 | 117 | /* Implement the low_arch_setup linux target ops method. */ |
68f5f838 | 118 | |
797bcff5 TBA |
119 | void |
120 | nios2_target::low_arch_setup () | |
68f5f838 | 121 | { |
3aee8918 | 122 | current_process ()->tdesc = tdesc_nios2_linux; |
68f5f838 SL |
123 | } |
124 | ||
daca57a7 | 125 | /* Implement the low_cannot_fetch_register linux target ops method. */ |
68f5f838 | 126 | |
daca57a7 TBA |
127 | bool |
128 | nios2_target::low_cannot_fetch_register (int regno) | |
68f5f838 | 129 | { |
daca57a7 | 130 | return (nios2_regmap[regno] == -1); |
68f5f838 SL |
131 | } |
132 | ||
daca57a7 | 133 | /* Implement the low_cannot_store_register linux target ops method. */ |
68f5f838 | 134 | |
daca57a7 TBA |
135 | bool |
136 | nios2_target::low_cannot_store_register (int regno) | |
68f5f838 | 137 | { |
daca57a7 | 138 | return (nios2_regmap[regno] == -1); |
68f5f838 SL |
139 | } |
140 | ||
af60a1ef SL |
141 | /* Breakpoint support. Also see comments on nios2_breakpoint_from_pc |
142 | in nios2-tdep.c. */ | |
143 | ||
144 | #if defined(__nios2_arch__) && __nios2_arch__ == 2 | |
145 | #define NIOS2_BREAKPOINT 0xb7fd0020 | |
146 | #define CDX_BREAKPOINT 0xd7c9 | |
147 | #else | |
148 | #define NIOS2_BREAKPOINT 0x003b6ffa | |
149 | #endif | |
68f5f838 | 150 | |
dd373349 AT |
151 | /* We only register the 4-byte breakpoint, even on R2 targets which also |
152 | support 2-byte breakpoints. Since there is no supports_z_point_type | |
153 | function provided, gdbserver never inserts software breakpoints itself | |
154 | and instead relies on GDB to insert the breakpoint of the correct length | |
155 | via a memory write. */ | |
af60a1ef | 156 | static const unsigned int nios2_breakpoint = NIOS2_BREAKPOINT; |
68f5f838 SL |
157 | #define nios2_breakpoint_len 4 |
158 | ||
3ca4edb6 | 159 | /* Implementation of target ops method "sw_breakpoint_from_kind". */ |
dd373349 | 160 | |
3ca4edb6 TBA |
161 | const gdb_byte * |
162 | nios2_target::sw_breakpoint_from_kind (int kind, int *size) | |
dd373349 AT |
163 | { |
164 | *size = nios2_breakpoint_len; | |
165 | return (const gdb_byte *) &nios2_breakpoint; | |
166 | } | |
167 | ||
d7146cda | 168 | /* Implement the low_breakpoint_at linux target ops method. */ |
68f5f838 | 169 | |
d7146cda TBA |
170 | bool |
171 | nios2_target::low_breakpoint_at (CORE_ADDR where) | |
68f5f838 SL |
172 | { |
173 | unsigned int insn; | |
174 | ||
af60a1ef SL |
175 | /* For R2, first check for the 2-byte CDX trap.n breakpoint encoding. */ |
176 | #if defined(__nios2_arch__) && __nios2_arch__ == 2 | |
d7146cda | 177 | read_memory (where, (unsigned char *) &insn, 2); |
af60a1ef | 178 | if (insn == CDX_BREAKPOINT) |
d7146cda | 179 | return true; |
af60a1ef SL |
180 | #endif |
181 | ||
d7146cda | 182 | read_memory (where, (unsigned char *) &insn, 4); |
68f5f838 | 183 | if (insn == nios2_breakpoint) |
d7146cda TBA |
184 | return true; |
185 | return false; | |
68f5f838 SL |
186 | } |
187 | ||
188 | /* Fetch the thread-local storage pointer for libthread_db. */ | |
189 | ||
190 | ps_err_e | |
754653a7 | 191 | ps_get_thread_area (struct ps_prochandle *ph, |
dda83cd7 | 192 | lwpid_t lwpid, int idx, void **base) |
68f5f838 SL |
193 | { |
194 | if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0) | |
195 | return PS_ERR; | |
196 | ||
197 | /* IDX is the bias from the thread pointer to the beginning of the | |
198 | thread descriptor. It has to be subtracted due to implementation | |
199 | quirks in libthread_db. */ | |
200 | *base = (void *) ((char *) *base - idx); | |
201 | ||
202 | return PS_OK; | |
203 | } | |
204 | ||
68f5f838 SL |
205 | /* Helper functions to collect/supply a single register REGNO. */ |
206 | ||
207 | static void | |
208 | nios2_collect_register (struct regcache *regcache, int regno, | |
209 | union nios2_register *reg) | |
210 | { | |
211 | union nios2_register tmp_reg; | |
212 | ||
213 | collect_register (regcache, regno, &tmp_reg.reg32); | |
214 | reg->reg32 = tmp_reg.reg32; | |
215 | } | |
216 | ||
217 | static void | |
218 | nios2_supply_register (struct regcache *regcache, int regno, | |
219 | const union nios2_register *reg) | |
220 | { | |
221 | supply_register (regcache, regno, reg->buf); | |
222 | } | |
223 | ||
224 | /* We have only a single register set on Nios II. */ | |
225 | ||
226 | static void | |
227 | nios2_fill_gregset (struct regcache *regcache, void *buf) | |
228 | { | |
b1c51e36 | 229 | union nios2_register *regset = (union nios2_register *) buf; |
68f5f838 SL |
230 | int i; |
231 | ||
232 | for (i = 1; i < nios2_num_regs; i++) | |
233 | nios2_collect_register (regcache, i, regset + i); | |
234 | } | |
235 | ||
236 | static void | |
237 | nios2_store_gregset (struct regcache *regcache, const void *buf) | |
238 | { | |
b1c51e36 | 239 | const union nios2_register *regset = (union nios2_register *) buf; |
68f5f838 SL |
240 | int i; |
241 | ||
242 | for (i = 0; i < nios2_num_regs; i++) | |
243 | nios2_supply_register (regcache, i, regset + i); | |
244 | } | |
68f5f838 | 245 | |
3aee8918 | 246 | static struct regset_info nios2_regsets[] = |
68f5f838 | 247 | { |
21e94bd9 SL |
248 | { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, |
249 | nios2_num_regs * 4, GENERAL_REGS, | |
68f5f838 | 250 | nios2_fill_gregset, nios2_store_gregset }, |
50bc912a | 251 | NULL_REGSET |
68f5f838 SL |
252 | }; |
253 | ||
3aee8918 PA |
254 | static struct regsets_info nios2_regsets_info = |
255 | { | |
256 | nios2_regsets, /* regsets */ | |
257 | 0, /* num_regsets */ | |
258 | NULL, /* disabled_regsets */ | |
259 | }; | |
260 | ||
261 | static struct usrregs_info nios2_usrregs_info = | |
262 | { | |
263 | nios2_num_regs, | |
264 | nios2_regmap, | |
265 | }; | |
266 | ||
aa8d21c9 | 267 | static struct regs_info myregs_info = |
3aee8918 PA |
268 | { |
269 | NULL, /* regset_bitmap */ | |
270 | &nios2_usrregs_info, | |
271 | &nios2_regsets_info | |
272 | }; | |
273 | ||
aa8d21c9 TBA |
274 | const regs_info * |
275 | nios2_target::get_regs_info () | |
3aee8918 | 276 | { |
aa8d21c9 | 277 | return &myregs_info; |
3aee8918 PA |
278 | } |
279 | ||
ef0478f6 TBA |
280 | /* The linux target ops object. */ |
281 | ||
282 | linux_process_target *the_linux_target = &the_nios2_target; | |
283 | ||
3aee8918 PA |
284 | void |
285 | initialize_low_arch (void) | |
286 | { | |
287 | init_registers_nios2_linux (); | |
288 | ||
289 | initialize_regsets_info (&nios2_regsets_info); | |
290 | } |