xref: /netbsd-src/external/gpl3/gdb/dist/gdbserver/linux-sparc-low.cc (revision 13ed34fa5696ce1ff8e9519eeb5619eee4331db8)
1 /* Low level interface to ptrace, for the remote server for GDB.
2    Copyright (C) 1995-2024 Free Software Foundation, Inc.
3 
4    This file is part of GDB.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18 
19 #include "linux-low.h"
20 
21 #include "nat/gdb_ptrace.h"
22 
23 #include "gdb_proc_service.h"
24 
25 /* The stack pointer is offset from the stack frame by a BIAS of 2047
26    (0x7ff) for 64-bit code.  BIAS is likely to be defined on SPARC
27    hosts, so undefine it first.  */
28 #undef BIAS
29 #define BIAS 2047
30 
31 #ifdef HAVE_SYS_REG_H
32 #include <sys/reg.h>
33 #endif
34 
35 #define INSN_SIZE 4
36 
37 #define SPARC_R_REGS_NUM 32
38 #define SPARC_F_REGS_NUM 48
39 #define SPARC_CONTROL_REGS_NUM 6
40 
41 #define sparc_num_regs \
42   (SPARC_R_REGS_NUM + SPARC_F_REGS_NUM + SPARC_CONTROL_REGS_NUM)
43 
44 /* Linux target op definitions for the SPARC architecture.  */
45 
46 class sparc_target : public linux_process_target
47 {
48 public:
49 
50   const regs_info *get_regs_info () override;
51 
52   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
53 
54 protected:
55 
56   void low_arch_setup () override;
57 
58   bool low_cannot_fetch_register (int regno) override;
59 
60   bool low_cannot_store_register (int regno) override;
61 
62   bool low_supports_breakpoints () override;
63 
64   CORE_ADDR low_get_pc (regcache *regcache) override;
65 
66   /* No low_set_pc is needed.  */
67 
68   bool low_breakpoint_at (CORE_ADDR pc) override;
69 };
70 
71 /* The singleton target ops object.  */
72 
73 static sparc_target the_sparc_target;
74 
75 bool
76 sparc_target::low_supports_breakpoints ()
77 {
78   return true;
79 }
80 
81 CORE_ADDR
82 sparc_target::low_get_pc (regcache *regcache)
83 {
84   return linux_get_pc_64bit (regcache);
85 }
86 
87 /* Each offset is multiplied by 8, because of the register size.
88    These offsets apply to the buffer sent/filled by ptrace.
89    Additionally, the array elements order corresponds to the .dat file, and the
90    gdb's registers enumeration order.  */
91 
92 static int sparc_regmap[] = {
93   /* These offsets correspond to GET/SETREGSET.  */
94 	-1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,	 /* g0 .. g7 */
95 	7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,	 /* o0 .. o5, sp, o7 */
96 	-1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,	 /* l0 .. l7 */
97 	-1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,	 /* i0 .. i5, fp, i7 */
98 
99   /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
100     0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,	   /*  f0 ..  f7 */
101     8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,	   /*  f8 .. f15 */
102    16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,	   /* f16 .. f23 */
103    24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,	   /* f24 .. f31 */
104 
105   /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
106    16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,	   /* f32 .. f46 */
107    24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,	   /* f48 .. f62 */
108 
109    17 *8, /*    pc */
110    18 *8, /*   npc */
111    16 *8, /* state */
112   /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed
113      next to f62.  */
114    32 *8, /*   fsr */
115       -1, /*  fprs */
116   /* Y register is 32-bits length, but gdb takes care of that.  */
117    19 *8, /*     y */
118 
119 };
120 
121 
122 struct regs_range_t
123 {
124   int regno_start;
125   int regno_end;
126 };
127 
128 static const struct regs_range_t gregs_ranges[] = {
129  {  0, 31 }, /*   g0 .. i7  */
130  { 80, 82 }, /*   pc .. state */
131  { 84, 85 }  /* fprs .. y */
132 };
133 
134 #define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
135 
136 static const struct regs_range_t fpregs_ranges[] = {
137  { 32, 79 }, /* f0 .. f62  */
138  { 83, 83 }  /* fsr */
139 };
140 
141 #define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
142 
143 /* Defined in auto-generated file reg-sparc64.c.  */
144 void init_registers_sparc64 (void);
145 extern const struct target_desc *tdesc_sparc64;
146 
147 bool
148 sparc_target::low_cannot_store_register (int regno)
149 {
150   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
151 }
152 
153 bool
154 sparc_target::low_cannot_fetch_register (int regno)
155 {
156   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
157 }
158 
159 static void
160 sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
161 {
162   int i;
163   CORE_ADDR addr = 0;
164   unsigned char tmp_reg_buf[8];
165   const int l0_regno = find_regno (regcache->tdesc, "l0");
166   const int i7_regno = l0_regno + 15;
167 
168   /* These registers have to be stored in the stack.  */
169   memcpy (&addr,
170 	  ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
171 	  sizeof (addr));
172 
173   addr += BIAS;
174 
175   for (i = l0_regno; i <= i7_regno; i++)
176     {
177       collect_register (regcache, i, tmp_reg_buf);
178       the_target->write_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
179       addr += sizeof (tmp_reg_buf);
180     }
181 }
182 
183 static void
184 sparc_fill_gregset (struct regcache *regcache, void *buf)
185 {
186   int i;
187   int range;
188 
189   for (range = 0; range < N_GREGS_RANGES; range++)
190     for (i = gregs_ranges[range].regno_start;
191 	 i <= gregs_ranges[range].regno_end; i++)
192       if (sparc_regmap[i] != -1)
193 	collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
194 
195   sparc_fill_gregset_to_stack (regcache, buf);
196 }
197 
198 static void
199 sparc_fill_fpregset (struct regcache *regcache, void *buf)
200 {
201   int i;
202   int range;
203 
204   for (range = 0; range < N_FPREGS_RANGES; range++)
205     for (i = fpregs_ranges[range].regno_start;
206 	 i <= fpregs_ranges[range].regno_end; i++)
207       collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
208 
209 }
210 
211 static void
212 sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
213 {
214   int i;
215   CORE_ADDR addr = 0;
216   unsigned char tmp_reg_buf[8];
217   const int l0_regno = find_regno (regcache->tdesc, "l0");
218   const int i7_regno = l0_regno + 15;
219 
220   /* These registers have to be obtained from the stack.  */
221   memcpy (&addr,
222 	  ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
223 	  sizeof (addr));
224 
225   addr += BIAS;
226 
227   for (i = l0_regno; i <= i7_regno; i++)
228     {
229       the_target->read_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
230       supply_register (regcache, i, tmp_reg_buf);
231       addr += sizeof (tmp_reg_buf);
232     }
233 }
234 
235 static void
236 sparc_store_gregset (struct regcache *regcache, const void *buf)
237 {
238   int i;
239   char zerobuf[8];
240   int range;
241 
242   memset (zerobuf, 0, sizeof (zerobuf));
243 
244   for (range = 0; range < N_GREGS_RANGES; range++)
245     for (i = gregs_ranges[range].regno_start;
246 	 i <= gregs_ranges[range].regno_end; i++)
247       if (sparc_regmap[i] != -1)
248 	supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
249       else
250 	supply_register (regcache, i, zerobuf);
251 
252   sparc_store_gregset_from_stack (regcache, buf);
253 }
254 
255 static void
256 sparc_store_fpregset (struct regcache *regcache, const void *buf)
257 {
258   int i;
259   int range;
260 
261   for (range = 0; range < N_FPREGS_RANGES; range++)
262     for (i = fpregs_ranges[range].regno_start;
263 	 i <= fpregs_ranges[range].regno_end;
264 	 i++)
265       supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
266 }
267 
268 static const gdb_byte sparc_breakpoint[INSN_SIZE] = {
269   0x91, 0xd0, 0x20, 0x01
270 };
271 #define sparc_breakpoint_len INSN_SIZE
272 
273 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
274 
275 const gdb_byte *
276 sparc_target::sw_breakpoint_from_kind (int kind, int *size)
277 {
278   *size = sparc_breakpoint_len;
279   return sparc_breakpoint;
280 }
281 
282 bool
283 sparc_target::low_breakpoint_at (CORE_ADDR where)
284 {
285   unsigned char insn[INSN_SIZE];
286 
287   read_memory (where, (unsigned char *) insn, sizeof (insn));
288 
289   if (memcmp (sparc_breakpoint, insn, sizeof (insn)) == 0)
290     return true;
291 
292   /* If necessary, recognize more trap instructions here.  GDB only
293      uses TRAP Always.  */
294 
295   return false;
296 }
297 
298 void
299 sparc_target::low_arch_setup ()
300 {
301   current_process ()->tdesc = tdesc_sparc64;
302 }
303 
304 static struct regset_info sparc_regsets[] = {
305   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
306     GENERAL_REGS,
307     sparc_fill_gregset, sparc_store_gregset },
308   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
309     FP_REGS,
310     sparc_fill_fpregset, sparc_store_fpregset },
311   NULL_REGSET
312 };
313 
314 static struct regsets_info sparc_regsets_info =
315   {
316     sparc_regsets, /* regsets */
317     0, /* num_regsets */
318     NULL, /* disabled_regsets */
319   };
320 
321 static struct usrregs_info sparc_usrregs_info =
322   {
323     sparc_num_regs,
324     /* No regmap needs to be provided since this impl. doesn't use
325        USRREGS.  */
326     NULL
327   };
328 
329 static struct regs_info myregs_info =
330   {
331     NULL, /* regset_bitmap */
332     &sparc_usrregs_info,
333     &sparc_regsets_info
334   };
335 
336 const regs_info *
337 sparc_target::get_regs_info ()
338 {
339   return &myregs_info;
340 }
341 
342 /* The linux target ops object.  */
343 
344 linux_process_target *the_linux_target = &the_sparc_target;
345 
346 void
347 initialize_low_arch (void)
348 {
349   /* Initialize the Linux target descriptions.  */
350   init_registers_sparc64 ();
351 
352   initialize_regsets_info (&sparc_regsets_info);
353 }
354