summaryrefslogtreecommitdiff
path: root/gdb/aarch64-ravenscar-thread.c
blob: 446f982449fb7df44a57bc6c102b24ff275cd318 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/* Ravenscar Aarch64 target support.

   Copyright (C) 2017-2019 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "aarch64-ravenscar-thread.h"

/* Local includes.  */
#include "aarch64-tdep.h"
#include "gdbcore.h"
#include "inferior.h"
#include "ravenscar-thread.h"
#include "regcache.h"

#define NO_OFFSET -1

/* See aarch64-tdep.h for register numbers.  */

static const int aarch64_context_offsets[] =
{
  /* X0 - X28 */
  NO_OFFSET, NO_OFFSET, NO_OFFSET, NO_OFFSET,
  NO_OFFSET, NO_OFFSET, NO_OFFSET, NO_OFFSET,
  NO_OFFSET, NO_OFFSET, NO_OFFSET, NO_OFFSET,
  NO_OFFSET, NO_OFFSET, NO_OFFSET, NO_OFFSET,
  NO_OFFSET, NO_OFFSET, NO_OFFSET, 0,
  8,         16,        24,        32,
  40,        48,        56,        64,
  72,

  /* FP, LR, SP, PC, CPSR */
  /* Note that as task switch is synchronous, PC is in fact the LR here */
  80,        88,        96,        88,
  NO_OFFSET,

  /* Q0 - Q31 */
  112,       128,       144,       160,
  176,       192,       208,       224,
  240,       256,       272,       288,
  304,       320,       336,       352,
  368,       384,       400,       416,
  432,       448,       464,       480,
  496,       512,       528,       544,
  560,       576,       592,       608,

  /* FPSR, FPCR */
  104,       108,

  /* FPU Saved field */
  624
};

/* The register layout info.  */

struct ravenscar_reg_info
{
  /* A table providing the offset relative to the context structure
     where each register is saved.  */
  const int *context_offsets;

  /* The number of elements in the context_offsets table above.  */
  int context_offsets_size;
};

/* supply register REGNUM, which has been saved on REGISTER_ADDR, to the
   regcache.  */

static void
supply_register_at_address (struct regcache *regcache, int regnum,
                            CORE_ADDR register_addr)
{
  struct gdbarch *gdbarch = regcache->arch ();
  int buf_size = register_size (gdbarch, regnum);
  gdb_byte *buf;

  buf = (gdb_byte *) alloca (buf_size);
  read_memory (register_addr, buf, buf_size);
  regcache->raw_supply (regnum, buf);
}

/* Return true if, for a non-running thread, REGNUM has been saved on the
   Thread_Descriptor.  */

static int
register_in_thread_descriptor_p (const struct ravenscar_reg_info *reg_info,
				 int regnum)
{
  /* Check FPU registers */
  return (regnum < reg_info->context_offsets_size
	  && reg_info->context_offsets[regnum] != NO_OFFSET);
}

/* to_fetch_registers when inferior_ptid is different from the running
   thread.  */

static void
aarch64_ravenscar_generic_fetch_registers
  (const struct ravenscar_reg_info *reg_info,
   struct regcache *regcache, int regnum)
{
  struct gdbarch *gdbarch = regcache->arch ();
  const int num_regs = gdbarch_num_regs (gdbarch);
  int current_regnum;
  CORE_ADDR current_address;
  CORE_ADDR thread_descriptor_address;

  /* The tid is the thread_id field, which is a pointer to the thread.  */
  thread_descriptor_address = (CORE_ADDR) inferior_ptid.tid ();

  /* Read registers.  */
  for (current_regnum = 0; current_regnum < num_regs; current_regnum++)
    {
      if (register_in_thread_descriptor_p (reg_info, current_regnum))
        {
          current_address = thread_descriptor_address
            + reg_info->context_offsets[current_regnum];
          supply_register_at_address (regcache, current_regnum,
                                      current_address);
        }
    }
}

/* to_store_registers when inferior_ptid is different from the running
   thread.  */

static void
aarch64_ravenscar_generic_store_registers
  (const struct ravenscar_reg_info *reg_info,
   struct regcache *regcache, int regnum)
{
  struct gdbarch *gdbarch = regcache->arch ();
  int buf_size = register_size (gdbarch, regnum);
  gdb_byte buf[buf_size];
  ULONGEST register_address;

  if (register_in_thread_descriptor_p (reg_info, regnum))
    register_address
      = inferior_ptid.tid () + reg_info->context_offsets [regnum];
  else
    return;

  regcache->raw_collect (regnum, buf);
  write_memory (register_address,
                buf,
                buf_size);
}

/* The ravenscar_reg_info for most Aarch64 targets.  */

static const struct ravenscar_reg_info aarch64_reg_info =
{
  aarch64_context_offsets,
  ARRAY_SIZE (aarch64_context_offsets),
};

struct aarch64_ravenscar_ops : public ravenscar_arch_ops
{
  void fetch_registers (struct regcache *regcache, int regnum) override
  {
    aarch64_ravenscar_generic_fetch_registers
      (&aarch64_reg_info, regcache, regnum);
  }

  void store_registers (struct regcache *regcache, int regnum) override
  {
    aarch64_ravenscar_generic_store_registers
      (&aarch64_reg_info, regcache, regnum);
  }
};

/* The ravenscar_arch_ops vector for most Aarch64 targets.  */

static struct aarch64_ravenscar_ops aarch64_ravenscar_ops;

/* Register aarch64_ravenscar_ops in GDBARCH.  */

void
register_aarch64_ravenscar_ops (struct gdbarch *gdbarch)
{
  set_gdbarch_ravenscar_ops (gdbarch, &aarch64_ravenscar_ops);
}