aboutsummaryrefslogtreecommitdiff
path: root/gdb/mips-nat.c
blob: 4d1b4a00c45ad1047a817c08c781b7d077106564 (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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
/* Low level DECstation interface to ptrace, for GDB when running native.
   Copyright 1988, 1989, 1991, 1992, 1995 Free Software Foundation, Inc.
   Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
   and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.

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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include <sys/ptrace.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/user.h>
#undef JB_S0
#undef JB_S1
#undef JB_S2
#undef JB_S3
#undef JB_S4
#undef JB_S5
#undef JB_S6
#undef JB_S7
#undef JB_SP
#undef JB_S8
#undef JB_PC
#undef JB_SR
#undef NJBREGS
#include <setjmp.h>		/* For JB_XXX.  */

/* Size of elements in jmpbuf */

#define JB_ELEMENT_SIZE 4

/* Map gdb internal register number to ptrace ``address''.
   These ``addresses'' are defined in DECstation <sys/ptrace.h> */

#define REGISTER_PTRACE_ADDR(regno) \
   (regno < 32 ? 		GPR_BASE + regno \
  : regno == PC_REGNUM ?	PC	\
  : regno == CAUSE_REGNUM ?	CAUSE	\
  : regno == HI_REGNUM ?	MMHI	\
  : regno == LO_REGNUM ?	MMLO	\
  : regno == FCRCS_REGNUM ?	FPC_CSR	\
  : regno == FCRIR_REGNUM ?	FPC_EIR	\
  : regno >= FP0_REGNUM ?	FPR_BASE + (regno - FP0_REGNUM) \
  : 0)

static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};

/* Get all registers from the inferior */

void
fetch_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[MAX_REGISTER_RAW_SIZE];
  register int i;

  registers_fetched ();

  for (regno = 1; regno < NUM_REGS; regno++)
    {
      regaddr = REGISTER_PTRACE_ADDR (regno);
      for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
 	{
 	  *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
				     (PTRACE_ARG3_TYPE) regaddr, 0);
 	  regaddr += sizeof (int);
 	}
      supply_register (regno, buf);
    }

  supply_register (ZERO_REGNUM, zerobuf);
  /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
  supply_register (FP_REGNUM, zerobuf);
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[80];

  if (regno > 0)
    {
      if (regno == ZERO_REGNUM || regno == PS_REGNUM
	  || regno == BADVADDR_REGNUM || regno == CAUSE_REGNUM
	  || regno == FCRIR_REGNUM || regno == FP_REGNUM
	  || (regno >= FIRST_EMBED_REGNUM && regno <= LAST_EMBED_REGNUM))
	return;
      regaddr = REGISTER_PTRACE_ADDR (regno);
      errno = 0;
      ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
	      read_register (regno));
      if (errno != 0)
	{
	  sprintf (buf, "writing register number %d", regno);
	  perror_with_name (buf);
	}
    }
  else
    {
      for (regno = 0; regno < NUM_REGS; regno++)
	store_inferior_registers (regno);
    }
}


/* Figure out where the longjmp will land.
   We expect the first arg to be a pointer to the jmp_buf structure from which
   we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
   This routine returns true on success. */

int
get_longjmp_target(pc)
     CORE_ADDR *pc;
{
  CORE_ADDR jb_addr;
  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];

  jb_addr = read_register (A0_REGNUM);

  if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
			  TARGET_PTR_BIT / TARGET_CHAR_BIT))
    return 0;

  *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);

  return 1;
}

/* Extract the register values out of the core file and store
   them where `read_register' will find them.

   CORE_REG_SECT points to the register values themselves, read into memory.
   CORE_REG_SIZE is the size of that area.
   WHICH says which set of registers we are handling (0 = int, 2 = float
         on machines where they are discontiguous).
   REG_ADDR is the offset from u.u_ar0 to the register values relative to
            core_reg_sect.  This is used with old-fashioned core files to
	    locate the registers in a large upage-plus-stack ".reg" section.
	    Original upage address X is at location core_reg_sect+x+reg_addr.
 */

void
fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
     char *core_reg_sect;
     unsigned core_reg_size;
     int which;
     unsigned reg_addr;
{
  register int regno;
  register unsigned int addr;
  int bad_reg = -1;
  register reg_ptr = -reg_addr;		/* Original u.u_ar0 is -reg_addr. */

  /* If u.u_ar0 was an absolute address in the core file, relativize it now,
     so we can use it as an offset into core_reg_sect.  When we're done,
     "register 0" will be at core_reg_sect+reg_ptr, and we can use
     register_addr to offset to the other registers.  If this is a modern
     core file without a upage, reg_ptr will be zero and this is all a big
     NOP.  */
  if (reg_ptr > core_reg_size)
#ifdef KERNEL_U_ADDR
    reg_ptr -= KERNEL_U_ADDR;
#else
    error ("Old mips core file can't be processed on this machine.");
#endif

  for (regno = 0; regno < NUM_REGS; regno++)
    {
      addr = register_addr (regno, reg_ptr);
      if (addr >= core_reg_size) {
	if (bad_reg < 0)
	  bad_reg = regno;
      } else {
	supply_register (regno, core_reg_sect + addr);
      }
    }
  if (bad_reg >= 0)
    {
      error ("Register %s not found in core file.", reg_names[bad_reg]);
    }
  supply_register (ZERO_REGNUM, zerobuf);
  /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
  supply_register (FP_REGNUM, zerobuf);
}

/* Return the address in the core dump or inferior of register REGNO.
   BLOCKEND is the address of the end of the user structure.  */

unsigned int
register_addr (regno, blockend)
     int regno;
     int blockend;
{
  int addr;

  if (regno < 0 || regno >= NUM_REGS)
    error ("Invalid register number %d.", regno);

  REGISTER_U_ADDR (addr, blockend, regno);

  return addr;
}