sparc-ravenscar-thread.c revision 1.5 
1/* Ravenscar SPARC target support.
2
3   Copyright (C) 2004-2015 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include "defs.h"
21#include "gdbcore.h"
22#include "regcache.h"
23#include "sparc-tdep.h"
24#include "inferior.h"
25#include "ravenscar-thread.h"
26#include "sparc-ravenscar-thread.h"
27
28static void sparc_ravenscar_fetch_registers (struct regcache *regcache,
29                                             int regnum);
30static void sparc_ravenscar_store_registers (struct regcache *regcache,
31                                             int regnum);
32static void sparc_ravenscar_prepare_to_store (struct regcache *regcache);
33
34/* Register offsets from a referenced address (exempli gratia the
35   Thread_Descriptor).  The referenced address depends on the register
36   number.  The Thread_Descriptor layout and the stack layout are documented
37   in the GNAT sources, in sparc-bb.h.  */
38
39static const int sparc_register_offsets[] =
40{
41  /* G0 - G7 */
42  -1,   0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C,
43  /* O0 - O7 */
44  0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C,
45  /* L0 - L7 */
46  0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C,
47  /* I0 - I7 */
48  0x20, 0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C,
49  /* F0 - F31 */
50  0x50, 0x54, 0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C,
51  0x70, 0x74, 0x78, 0x7C, 0x80, 0x84, 0x88, 0x8C,
52  0x90, 0x94, 0x99, 0x9C, 0xA0, 0xA4, 0xA8, 0xAC,
53  0xB0, 0xB4, 0xBB, 0xBC, 0xC0, 0xC4, 0xC8, 0xCC,
54  /* Y  PSR   WIM   TBR   PC    NPC   FPSR  CPSR */
55  0x40, 0x20, 0x44, -1,   0x1C, -1,   0x4C, -1
56};
57
58/* supply register REGNUM, which has been saved on REGISTER_ADDR, to the
59   regcache.  */
60
61static void
62supply_register_at_address (struct regcache *regcache, int regnum,
63                            CORE_ADDR register_addr)
64{
65  struct gdbarch *gdbarch = get_regcache_arch (regcache);
66  int buf_size = register_size (gdbarch, regnum);
67  gdb_byte *buf;
68
69  buf = alloca (buf_size);
70  read_memory (register_addr, buf, buf_size);
71  regcache_raw_supply (regcache, regnum, buf);
72}
73
74/* Return true if, for a non-running thread, REGNUM has been saved on the
75   stack.  */
76
77static int
78register_on_stack_p (int regnum)
79{
80  return (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_L7_REGNUM)
81    || (regnum >= SPARC_I0_REGNUM && regnum <= SPARC_I7_REGNUM);
82}
83
84/* Return true if, for a non-running thread, REGNUM has been saved on the
85   Thread_Descriptor.  */
86
87static int
88register_in_thread_descriptor_p (int regnum)
89{
90  return (regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)
91    || (regnum == SPARC32_PSR_REGNUM)
92    || (regnum >= SPARC_G1_REGNUM && regnum <= SPARC_G7_REGNUM)
93    || (regnum == SPARC32_Y_REGNUM)
94    || (regnum == SPARC32_WIM_REGNUM)
95    || (regnum == SPARC32_FSR_REGNUM)
96    || (regnum >= SPARC_F0_REGNUM && regnum <= SPARC_F0_REGNUM + 31)
97    || (regnum == SPARC32_PC_REGNUM);
98}
99
100/* to_fetch_registers when inferior_ptid is different from the running
101   thread.  */
102
103static void
104sparc_ravenscar_fetch_registers (struct regcache *regcache, int regnum)
105{
106  struct gdbarch *gdbarch = get_regcache_arch (regcache);
107  const int sp_regnum = gdbarch_sp_regnum (gdbarch);
108  const int num_regs = gdbarch_num_regs (gdbarch);
109  int current_regnum;
110  CORE_ADDR current_address;
111  CORE_ADDR thread_descriptor_address;
112  ULONGEST stack_address;
113
114  /* The tid is the thread_id field, which is a pointer to the thread.  */
115  thread_descriptor_address = (CORE_ADDR) ptid_get_tid (inferior_ptid);
116
117  /* Read the saved SP in the context buffer.  */
118  current_address = thread_descriptor_address
119    + sparc_register_offsets [sp_regnum];
120  supply_register_at_address (regcache, sp_regnum, current_address);
121  regcache_cooked_read_unsigned (regcache, sp_regnum, &stack_address);
122
123  /* Read registers.  */
124  for (current_regnum = 0; current_regnum < num_regs; current_regnum ++)
125    {
126      if (register_in_thread_descriptor_p (current_regnum))
127        {
128          current_address = thread_descriptor_address
129            + sparc_register_offsets [current_regnum];
130          supply_register_at_address (regcache, current_regnum,
131                                      current_address);
132        }
133      else if (register_on_stack_p (current_regnum))
134        {
135          current_address = stack_address
136            + sparc_register_offsets [current_regnum];
137          supply_register_at_address (regcache, current_regnum,
138                                      current_address);
139        }
140    }
141}
142
143/* to_prepare_to_store when inferior_ptid is different from the running
144   thread.  */
145
146static void
147sparc_ravenscar_prepare_to_store (struct regcache *regcache)
148{
149  /* Nothing to do.  */
150}
151
152/* to_store_registers when inferior_ptid is different from the running
153   thread.  */
154
155static void
156sparc_ravenscar_store_registers (struct regcache *regcache, int regnum)
157{
158  struct gdbarch *gdbarch = get_regcache_arch (regcache);
159  int buf_size = register_size (gdbarch, regnum);
160  gdb_byte buf[buf_size];
161  ULONGEST register_address;
162
163  if (register_in_thread_descriptor_p (regnum))
164    register_address =
165      ptid_get_tid (inferior_ptid) + sparc_register_offsets [regnum];
166  else if (register_on_stack_p (regnum))
167    {
168      regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM,
169                                     &register_address);
170      register_address += sparc_register_offsets [regnum];
171    }
172  else
173    return;
174
175  regcache_raw_collect (regcache, regnum, buf);
176  write_memory (register_address,
177                buf,
178                buf_size);
179}
180
181static struct ravenscar_arch_ops sparc_ravenscar_ops =
182{
183  sparc_ravenscar_fetch_registers,
184  sparc_ravenscar_store_registers,
185  sparc_ravenscar_prepare_to_store
186};
187
188/* Register ravenscar_arch_ops in GDBARCH.  */
189
190void
191register_sparc_ravenscar_ops (struct gdbarch *gdbarch)
192{
193  set_gdbarch_ravenscar_ops (gdbarch, &sparc_ravenscar_ops);
194}
195