1/* Low level DECstation interface to ptrace, for GDB when running native.
2   Copyright 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1999, 2000, 2001
3   Free Software Foundation, Inc.
4   Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
5   and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
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 2 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, write to the Free Software
21   Foundation, Inc., 59 Temple Place - Suite 330,
22   Boston, MA 02111-1307, USA.  */
23
24#include "defs.h"
25#include "inferior.h"
26#include "gdbcore.h"
27#include "regcache.h"
28#include <sys/ptrace.h>
29#include <sys/types.h>
30#include <sys/param.h>
31#include <sys/user.h>
32#undef JB_S0
33#undef JB_S1
34#undef JB_S2
35#undef JB_S3
36#undef JB_S4
37#undef JB_S5
38#undef JB_S6
39#undef JB_S7
40#undef JB_SP
41#undef JB_S8
42#undef JB_PC
43#undef JB_SR
44#undef NJBREGS
45#include <setjmp.h>		/* For JB_XXX.  */
46
47/* Size of elements in jmpbuf */
48
49#define JB_ELEMENT_SIZE 4
50
51/* Map gdb internal register number to ptrace ``address''.
52   These ``addresses'' are defined in DECstation <sys/ptrace.h> */
53
54static int
55register_ptrace_addr (int regno)
56{
57  return (regno < 32 ? GPR_BASE + regno
58	  : regno == mips_regnum (current_gdbarch)->pc ? PC
59	  : regno == mips_regnum (current_gdbarch)->cause ? CAUSE
60	  : regno == mips_regnum (current_gdbarch)->hi ? MMHI
61	  : regno == mips_regnum (current_gdbarch)->lo ? MMLO
62	  : regno == mips_regnum (current_gdbarch)->fp_control_status ? FPC_CSR
63	  : regno == mips_regnum (current_gdbarch)->fp_implementation_revision ? FPC_EIR
64	  : regno >= FP0_REGNUM ? FPR_BASE + (regno - FP0_REGNUM)
65	  : 0);
66}
67
68static void fetch_core_registers (char *, unsigned, int, CORE_ADDR);
69
70/* Get all registers from the inferior */
71
72void
73fetch_inferior_registers (int regno)
74{
75  unsigned int regaddr;
76  char buf[MAX_REGISTER_SIZE];
77  int i;
78  char zerobuf[MAX_REGISTER_SIZE];
79  memset (zerobuf, 0, MAX_REGISTER_SIZE);
80
81  deprecated_registers_fetched ();
82
83  for (regno = 1; regno < NUM_REGS; regno++)
84    {
85      regaddr = register_ptrace_addr (regno);
86      for (i = 0; i < DEPRECATED_REGISTER_RAW_SIZE (regno); i += sizeof (int))
87	{
88	  *(int *) &buf[i] = ptrace (PT_READ_U, PIDGET (inferior_ptid),
89				     (PTRACE_ARG3_TYPE) regaddr, 0);
90	  regaddr += sizeof (int);
91	}
92      supply_register (regno, buf);
93    }
94
95  supply_register (ZERO_REGNUM, zerobuf);
96  /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
97  supply_register (DEPRECATED_FP_REGNUM, zerobuf);
98}
99
100/* Store our register values back into the inferior.
101   If REGNO is -1, do this for all registers.
102   Otherwise, REGNO specifies which register (so we can save time).  */
103
104void
105store_inferior_registers (int regno)
106{
107  unsigned int regaddr;
108  char buf[80];
109
110  if (regno > 0)
111    {
112      if (regno == ZERO_REGNUM || regno == PS_REGNUM
113	  || regno == mips_regnum (current_gdbarch)->badvaddr
114	  || regno == mips_regnum (current_gdbarch)->cause
115	  || regno == mips_regnum (current_gdbarch)->fp_implementation_revision
116	  || regno == DEPRECATED_FP_REGNUM
117	  || (regno >= FIRST_EMBED_REGNUM && regno <= LAST_EMBED_REGNUM))
118	return;
119      regaddr = register_ptrace_addr (regno);
120      errno = 0;
121      ptrace (PT_WRITE_U, PIDGET (inferior_ptid), (PTRACE_ARG3_TYPE) regaddr,
122	      read_register (regno));
123      if (errno != 0)
124	{
125	  sprintf (buf, "writing register number %d", regno);
126	  perror_with_name (buf);
127	}
128    }
129  else
130    {
131      for (regno = 0; regno < NUM_REGS; regno++)
132	store_inferior_registers (regno);
133    }
134}
135
136
137/* Figure out where the longjmp will land.
138   We expect the first arg to be a pointer to the jmp_buf structure from which
139   we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
140   This routine returns true on success. */
141
142int
143get_longjmp_target (CORE_ADDR *pc)
144{
145  CORE_ADDR jb_addr;
146  char *buf;
147
148  buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
149  jb_addr = read_register (A0_REGNUM);
150
151  if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
152			  TARGET_PTR_BIT / TARGET_CHAR_BIT))
153    return 0;
154
155  *pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
156
157  return 1;
158}
159
160/* Extract the register values out of the core file and store
161   them where `read_register' will find them.
162
163   CORE_REG_SECT points to the register values themselves, read into memory.
164   CORE_REG_SIZE is the size of that area.
165   WHICH says which set of registers we are handling (0 = int, 2 = float
166   on machines where they are discontiguous).
167   REG_ADDR is the offset from u.u_ar0 to the register values relative to
168   core_reg_sect.  This is used with old-fashioned core files to
169   locate the registers in a large upage-plus-stack ".reg" section.
170   Original upage address X is at location core_reg_sect+x+reg_addr.
171 */
172
173static void
174fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
175		      CORE_ADDR reg_addr)
176{
177  int regno;
178  unsigned int addr;
179  int bad_reg = -1;
180  reg_ptr = -reg_addr;	/* Original u.u_ar0 is -reg_addr. */
181
182  char zerobuf[MAX_REGISTER_SIZE];
183  memset (zerobuf, 0, MAX_REGISTER_SIZE);
184
185
186  /* If u.u_ar0 was an absolute address in the core file, relativize it now,
187     so we can use it as an offset into core_reg_sect.  When we're done,
188     "register 0" will be at core_reg_sect+reg_ptr, and we can use
189     register_addr to offset to the other registers.  If this is a modern
190     core file without a upage, reg_ptr will be zero and this is all a big
191     NOP.  */
192  if (reg_ptr > core_reg_size)
193#ifdef KERNEL_U_ADDR
194    reg_ptr -= KERNEL_U_ADDR;
195#else
196    error ("Old mips core file can't be processed on this machine.");
197#endif
198
199  for (regno = 0; regno < NUM_REGS; regno++)
200    {
201      addr = register_addr (regno, reg_ptr);
202      if (addr >= core_reg_size)
203	{
204	  if (bad_reg < 0)
205	    bad_reg = regno;
206	}
207      else
208	{
209	  supply_register (regno, core_reg_sect + addr);
210	}
211    }
212  if (bad_reg >= 0)
213    {
214      error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
215    }
216  supply_register (ZERO_REGNUM, zerobuf);
217  /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
218  supply_register (DEPRECATED_FP_REGNUM, zerobuf);
219}
220
221/* Return the address in the core dump or inferior of register REGNO.
222   BLOCKEND is the address of the end of the user structure.  */
223
224CORE_ADDR
225register_addr (int regno, CORE_ADDR blockend)
226{
227  CORE_ADDR addr;
228
229  if (regno < 0 || regno >= NUM_REGS)
230    error ("Invalid register number %d.", regno);
231
232  REGISTER_U_ADDR (addr, blockend, regno);
233
234  return addr;
235}
236
237
238/* Register that we are able to handle mips core file formats.
239   FIXME: is this really bfd_target_unknown_flavour? */
240
241static struct core_fns mips_core_fns =
242{
243  bfd_target_unknown_flavour,		/* core_flavour */
244  default_check_format,			/* check_format */
245  default_core_sniffer,			/* core_sniffer */
246  fetch_core_registers,			/* core_read_registers */
247  NULL					/* next */
248};
249
250void
251_initialize_core_mips (void)
252{
253  add_core_fns (&mips_core_fns);
254}
255