[binutils.git] / gdb / i386bsd-nat.c

/* Native-dependent code for modern i386 BSD's.
   Copyright 2000, 2001, 2002 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 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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "regcache.h"

#include "gdb_assert.h"
#include <signal.h>
#include <stddef.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <machine/reg.h>
#include <machine/frame.h>

#ifdef HAVE_SYS_PROCFS_H
#include <sys/procfs.h>
#endif

#ifndef HAVE_GREGSET_T
typedef struct reg gregset_t;
#endif

#ifndef HAVE_FPREGSET_T
typedef struct fpreg fpregset_t;
#endif

#include "gregset.h"
\f

/* In older BSD versions we cannot get at some of the segment
   registers.  FreeBSD for example didn't support the %fs and %gs
   registers until the 3.0 release.  We have autoconf checks for their
   presence, and deal gracefully with their absence.  */

/* Registers we shouldn't try to fetch.  */
#if !defined (CANNOT_FETCH_REGISTER)
#define CANNOT_FETCH_REGISTER(regno) cannot_fetch_register (regno)
#endif

/* Registers we shouldn't try to store.  */
#if !defined (CANNOT_STORE_REGISTER)
#define CANNOT_STORE_REGISTER(regno) cannot_fetch_register (regno)
#endif

/* Offset to the gregset_t location where REG is stored.  */
#define REG_OFFSET(reg) offsetof (gregset_t, reg)

/* At reg_offset[REGNO] you'll find the offset to the gregset_t
   location where the GDB register REGNO is stored.  Unsupported
   registers are marked with `-1'.  */
static int reg_offset[] =
{
  REG_OFFSET (r_eax),
  REG_OFFSET (r_ecx),
  REG_OFFSET (r_edx),
  REG_OFFSET (r_ebx),
  REG_OFFSET (r_esp),
  REG_OFFSET (r_ebp),
  REG_OFFSET (r_esi),
  REG_OFFSET (r_edi),
  REG_OFFSET (r_eip),
  REG_OFFSET (r_eflags),
  REG_OFFSET (r_cs),
  REG_OFFSET (r_ss),
  REG_OFFSET (r_ds),
  REG_OFFSET (r_es),
#ifdef HAVE_STRUCT_REG_R_FS
  REG_OFFSET (r_fs),
#else
  -1,
#endif
#ifdef HAVE_STRUCT_REG_R_GS
  REG_OFFSET (r_gs)
#else
  -1
#endif
};

#define REG_ADDR(regset, regno) ((char *) (regset) + reg_offset[regno])

/* Macro to determine if a register is fetched with PT_GETREGS.  */
#define GETREGS_SUPPLIES(regno) \
  ((0 <= (regno) && (regno) <= 15))

#ifdef HAVE_PT_GETXMMREGS
/* Set to 1 if the kernel supports PT_GETXMMREGS.  Initialized to -1
   so that we try PT_GETXMMREGS the first time around.  */
static int have_ptrace_xmmregs = -1;
#endif

/* Return nonzero if we shouldn't try to fetch register REGNO.  */

static int
cannot_fetch_register (int regno)
{
  return (reg_offset[regno] == -1);
}
\f

/* Transfering the registers between GDB, inferiors and core files.  */

/* Fill GDB's register array with the general-purpose register values
   in *GREGSETP.  */

void
supply_gregset (gregset_t *gregsetp)
{
  int i;

  for (i = 0; i < NUM_GREGS; i++)
    {
      if (CANNOT_FETCH_REGISTER (i))
	supply_register (i, NULL);
      else
	supply_register (i, REG_ADDR (gregsetp, i));
    }
}

/* Fill register REGNO (if it is a general-purpose register) in
   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
   do this for all registers.  */

void
fill_gregset (gregset_t *gregsetp, int regno)
{
  int i;

  for (i = 0; i < NUM_GREGS; i++)
    if ((regno == -1 || regno == i) && ! CANNOT_STORE_REGISTER (i))
      regcache_collect (i, REG_ADDR (gregsetp, i));
}

#include "i387-nat.h"

/* Fill GDB's register array with the floating-point register values
   in *FPREGSETP.  */

void
supply_fpregset (fpregset_t *fpregsetp)
{
  i387_supply_fsave ((char *) fpregsetp);
}

/* Fill register REGNO (if it is a floating-point register) in
   *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
   do this for all registers.  */

void
fill_fpregset (fpregset_t *fpregsetp, int regno)
{
  i387_fill_fsave ((char *) fpregsetp, regno);
}

/* Fetch register REGNO from the inferior.  If REGNO is -1, do this
   for all registers (including the floating point registers).  */

void
fetch_inferior_registers (int regno)
{

  if (regno == -1 || GETREGS_SUPPLIES (regno))
    {
      gregset_t gregs;

      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
		  (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	perror_with_name ("Couldn't get registers");

      supply_gregset (&gregs);
      if (regno != -1)
	return;
    }

  if (regno == -1 || regno >= FP0_REGNUM)
    {
      fpregset_t fpregs;
#ifdef HAVE_PT_GETXMMREGS
      char xmmregs[512];

      if (have_ptrace_xmmregs != 0 &&
	  ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
		 (PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	{
	  have_ptrace_xmmregs = 1;
	  i387_supply_fxsave (xmmregs);
	}
      else
	{
          if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	    perror_with_name ("Couldn't get floating point status");

	  supply_fpregset (&fpregs);
	}
#else
      if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
		  (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	perror_with_name ("Couldn't get floating point status");

      supply_fpregset (&fpregs);
#endif
    }
}

/* Store register REGNO back into the inferior.  If REGNO is -1, do
   this for all registers (including the floating point registers).  */

void
store_inferior_registers (int regno)
{

  if (regno == -1 || GETREGS_SUPPLIES (regno))
    {
      gregset_t gregs;

      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
                  (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
        perror_with_name ("Couldn't get registers");

      fill_gregset (&gregs, regno);

      if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
	          (PTRACE_ARG3_TYPE) &gregs, 0) == -1)
        perror_with_name ("Couldn't write registers");

      if (regno != -1)
	return;
    }

  if (regno == -1 || regno >= FP0_REGNUM)
    {
      fpregset_t fpregs;
#ifdef HAVE_PT_GETXMMREGS
      char xmmregs[512];

      if (have_ptrace_xmmregs != 0 &&
	  ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
		 (PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	{
	  have_ptrace_xmmregs = 1;

	  i387_fill_fxsave (xmmregs, regno);

	  if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) xmmregs, 0) == -1)
            perror_with_name ("Couldn't write XMM registers");
	}
      else
	{
	  have_ptrace_xmmregs = 0;
#endif
          if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	    perror_with_name ("Couldn't get floating point status");

          fill_fpregset (&fpregs, regno);
  
          if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
		      (PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	    perror_with_name ("Couldn't write floating point status");
#ifdef HAVE_PT_GETXMMREGS
        }
#endif
    }
}
\f

/* Support for debug registers.  */

#ifdef HAVE_PT_GETDBREGS

/* Not all versions of FreeBSD/i386 that support the debug registers
   have this macro.  */
#ifndef DBREG_DRX
#define DBREG_DRX(d, x) ((&d->dr0)[x])
#endif

static void
i386bsd_dr_set (int regnum, unsigned int value)
{
  struct dbreg dbregs;

  if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
              (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
    perror_with_name ("Couldn't get debug registers");

  /* For some mysterious reason, some of the reserved bits in the
     debug control register get set.  Mask these off, otherwise the
     ptrace call below will fail.  */
  dbregs.dr7 &= ~(0x0000fc00);

  DBREG_DRX ((&dbregs), regnum) = value;

  if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid),
              (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
    perror_with_name ("Couldn't write debug registers");
}

void
i386bsd_dr_set_control (unsigned long control)
{
  i386bsd_dr_set (7, control);
}

void
i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
{
  gdb_assert (regnum >= 0 && regnum <= 4);

  i386bsd_dr_set (regnum, addr);
}

void
i386bsd_dr_reset_addr (int regnum)
{
  gdb_assert (regnum >= 0 && regnum <= 4);

  i386bsd_dr_set (regnum, 0);
}

unsigned long
i386bsd_dr_get_status (void)
{
  struct dbreg dbregs;

  /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
     ptrace call fails breaks debugging remote targets.  The correct
     way to fix this is to add the hardware breakpoint and watchpoint
     stuff to the target vector.  For now, just return zero if the
     ptrace call fails.  */
  if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
	      (PTRACE_ARG3_TYPE) & dbregs, 0) == -1)
#if 0
    perror_with_name ("Couldn't read debug registers");
#else
    return 0;
#endif

  return dbregs.dr6;
}

#endif /* PT_GETDBREGS */
\f

/* Support for the user struct.  */

/* Return the address register REGNO.  BLOCKEND is the value of
   u.u_ar0, which should point to the registers.  */

CORE_ADDR
register_u_addr (CORE_ADDR blockend, int regno)
{
  return (CORE_ADDR) REG_ADDR (blockend, regno);
}

#include <sys/param.h>
#include <sys/user.h>

/* Return the size of the user struct.  */

int
kernel_u_size (void)
{
  return (sizeof (struct user));
}
\f
/* See i386bsd-tdep.c.  */
extern int i386bsd_sigcontext_pc_offset;

void
_initialize_i386bsd_nat (void)
{
  /* To support the recognition of signal handlers, i386bsd-tdep.c
     hardcodes some constants.  Inclusion of this file means that we
     are compiling a native debugger, which means that we can use the
     system header files and sysctl(3) to get at the relevant
     information.  */

  /* Override the default value for the offset of the program counter
     in the sigcontext structure.  */
  i386bsd_sigcontext_pc_offset = offsetof (struct sigcontext, sc_pc);
}
Commit	Line	Data
e6031aeb	1	/* Native-dependent code for modern i386 BSD's.
7e89e357	2	Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
e6031aeb MK	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 2 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, write to the Free Software
	18	Foundation, Inc., 59 Temple Place - Suite 330,
	19	Boston, MA 02111-1307, USA. */
	20
	21	#include "defs.h"
	22	#include "inferior.h"
4e052eda	23	#include "regcache.h"
e6031aeb	24
0afdd437	25	#include "gdb_assert.h"
b7247919 MK	26	#include <signal.h>
b7247919 MK	27	#include <stddef.h>
e6031aeb MK	28	#include <sys/types.h>
	29	#include <sys/ptrace.h>
	30	#include <machine/reg.h>
	31	#include <machine/frame.h>
	32
	33	#ifdef HAVE_SYS_PROCFS_H
	34	#include <sys/procfs.h>
	35	#endif
	36
	37	#ifndef HAVE_GREGSET_T
	38	typedef struct reg gregset_t;
	39	#endif
	40
	41	#ifndef HAVE_FPREGSET_T
	42	typedef struct fpreg fpregset_t;
	43	#endif
	44
b051bfa4 MK	45	#include "gregset.h"
	46	\f
	47
e6031aeb MK	48	/* In older BSD versions we cannot get at some of the segment
	49	registers. FreeBSD for example didn't support the %fs and %gs
	50	registers until the 3.0 release. We have autoconf checks for their
	51	presence, and deal gracefully with their absence. */
	52
	53	/* Registers we shouldn't try to fetch. */
	54	#if !defined (CANNOT_FETCH_REGISTER)
	55	#define CANNOT_FETCH_REGISTER(regno) cannot_fetch_register (regno)
	56	#endif
	57
	58	/* Registers we shouldn't try to store. */
	59	#if !defined (CANNOT_STORE_REGISTER)
b051bfa4	60	#define CANNOT_STORE_REGISTER(regno) cannot_fetch_register (regno)
e6031aeb MK	61	#endif
	62
	63	/* Offset to the gregset_t location where REG is stored. */
	64	#define REG_OFFSET(reg) offsetof (gregset_t, reg)
	65
	66	/* At reg_offset[REGNO] you'll find the offset to the gregset_t
	67	location where the GDB register REGNO is stored. Unsupported
	68	registers are marked with `-1'. */
	69	static int reg_offset[] =
	70	{
	71	REG_OFFSET (r_eax),
	72	REG_OFFSET (r_ecx),
	73	REG_OFFSET (r_edx),
2c48bda3	74	REG_OFFSET (r_ebx),
e6031aeb MK	75	REG_OFFSET (r_esp),
	76	REG_OFFSET (r_ebp),
	77	REG_OFFSET (r_esi),
	78	REG_OFFSET (r_edi),
	79	REG_OFFSET (r_eip),
	80	REG_OFFSET (r_eflags),
	81	REG_OFFSET (r_cs),
	82	REG_OFFSET (r_ss),
	83	REG_OFFSET (r_ds),
	84	REG_OFFSET (r_es),
422ea4b8	85	#ifdef HAVE_STRUCT_REG_R_FS
e6031aeb MK	86	REG_OFFSET (r_fs),
	87	#else
	88	-1,
	89	#endif
422ea4b8	90	#ifdef HAVE_STRUCT_REG_R_GS
e6031aeb MK	91	REG_OFFSET (r_gs)
	92	#else
	93	-1
	94	#endif
	95	};
	96
	97	#define REG_ADDR(regset, regno) ((char *) (regset) + reg_offset[regno])
	98
7e89e357 JT	99	/* Macro to determine if a register is fetched with PT_GETREGS. */
	100	#define GETREGS_SUPPLIES(regno) \
	101	((0 <= (regno) && (regno) <= 15))
	102
	103	#ifdef HAVE_PT_GETXMMREGS
	104	/* Set to 1 if the kernel supports PT_GETXMMREGS. Initialized to -1
	105	so that we try PT_GETXMMREGS the first time around. */
	106	static int have_ptrace_xmmregs = -1;
	107	#endif
	108
e6031aeb MK	109	/* Return nonzero if we shouldn't try to fetch register REGNO. */
	110
	111	static int
	112	cannot_fetch_register (int regno)
	113	{
	114	return (reg_offset[regno] == -1);
	115	}
	116	\f
	117
	118	/* Transfering the registers between GDB, inferiors and core files. */
	119
ad2a4d09	120	/* Fill GDB's register array with the general-purpose register values
e6031aeb MK	121	in GREGSETP. /
	122
	123	void
	124	supply_gregset (gregset_t *gregsetp)
	125	{
e6031aeb MK	126	int i;
	127
	128	for (i = 0; i < NUM_GREGS; i++)
	129	{
	130	if (CANNOT_FETCH_REGISTER (i))
b051bfa4	131	supply_register (i, NULL);
e6031aeb MK	132	else
	133	supply_register (i, REG_ADDR (gregsetp, i));
	134	}
	135	}
	136
	137	/* Fill register REGNO (if it is a general-purpose register) in
	138	*GREGSETPS with the value in GDB's register array. If REGNO is -1,
	139	do this for all registers. */
	140
	141	void
	142	fill_gregset (gregset_t *gregsetp, int regno)
	143	{
	144	int i;
	145
	146	for (i = 0; i < NUM_GREGS; i++)
	147	if ((regno == -1 \|\| regno == i) && ! CANNOT_STORE_REGISTER (i))
7e89e357	148	regcache_collect (i, REG_ADDR (gregsetp, i));
e6031aeb MK	149	}
	150
	151	#include "i387-nat.h"
	152
	153	/* Fill GDB's register array with the floating-point register values
	154	in FPREGSETP. /
	155
	156	void
	157	supply_fpregset (fpregset_t *fpregsetp)
	158	{
	159	i387_supply_fsave ((char *) fpregsetp);
	160	}
	161
	162	/* Fill register REGNO (if it is a floating-point register) in
	163	*FPREGSETP with the value in GDB's register array. If REGNO is -1,
	164	do this for all registers. */
	165
	166	void
	167	fill_fpregset (fpregset_t *fpregsetp, int regno)
	168	{
	169	i387_fill_fsave ((char *) fpregsetp, regno);
	170	}
	171
	172	/* Fetch register REGNO from the inferior. If REGNO is -1, do this
	173	for all registers (including the floating point registers). */
	174
	175	void
	176	fetch_inferior_registers (int regno)
	177	{
e6031aeb	178
7e89e357 JT	179	if (regno == -1 \|\| GETREGS_SUPPLIES (regno))
	180	{
	181	gregset_t gregs;
	182
	183	if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
	184	(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	185	perror_with_name ("Couldn't get registers");
e6031aeb	186
7e89e357 JT	187	supply_gregset (&gregs);
	188	if (regno != -1)
	189	return;
	190	}
e6031aeb MK	191
	192	if (regno == -1 \|\| regno >= FP0_REGNUM)
	193	{
	194	fpregset_t fpregs;
7e89e357 JT	195	#ifdef HAVE_PT_GETXMMREGS
	196	char xmmregs[512];
	197
	198	if (have_ptrace_xmmregs != 0 &&
	199	ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
	200	(PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	201	{
	202	have_ptrace_xmmregs = 1;
	203	i387_supply_fxsave (xmmregs);
	204	}
	205	else
	206	{
	207	if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
	208	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	209	perror_with_name ("Couldn't get floating point status");
e6031aeb	210
7e89e357 JT	211	supply_fpregset (&fpregs);
	212	}
	213	#else
39f77062	214	if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
e6031aeb MK	215	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	216	perror_with_name ("Couldn't get floating point status");
	217
	218	supply_fpregset (&fpregs);
7e89e357	219	#endif
e6031aeb	220	}
b051bfa4	221	}
e6031aeb MK	222
	223	/* Store register REGNO back into the inferior. If REGNO is -1, do
	224	this for all registers (including the floating point registers). */
	225
	226	void
	227	store_inferior_registers (int regno)
	228	{
e6031aeb	229
7e89e357 JT	230	if (regno == -1 \|\| GETREGS_SUPPLIES (regno))
	231	{
	232	gregset_t gregs;
	233
	234	if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
	235	(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	236	perror_with_name ("Couldn't get registers");
e6031aeb	237
7e89e357	238	fill_gregset (&gregs, regno);
e6031aeb	239
7e89e357 JT	240	if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
	241	(PTRACE_ARG3_TYPE) &gregs, 0) == -1)
	242	perror_with_name ("Couldn't write registers");
	243
	244	if (regno != -1)
	245	return;
	246	}
e6031aeb MK	247
	248	if (regno == -1 \|\| regno >= FP0_REGNUM)
	249	{
	250	fpregset_t fpregs;
7e89e357 JT	251	#ifdef HAVE_PT_GETXMMREGS
7e89e357 JT	252	char xmmregs[512];
e6031aeb	253
7e89e357 JT	254	if (have_ptrace_xmmregs != 0 &&
	255	ptrace(PT_GETXMMREGS, PIDGET (inferior_ptid),
	256	(PTRACE_ARG3_TYPE) xmmregs, 0) == 0)
	257	{
	258	have_ptrace_xmmregs = 1;
	259
	260	i387_fill_fxsave (xmmregs, regno);
e6031aeb	261
7e89e357 JT	262	if (ptrace (PT_SETXMMREGS, PIDGET (inferior_ptid),
	263	(PTRACE_ARG3_TYPE) xmmregs, 0) == -1)
	264	perror_with_name ("Couldn't write XMM registers");
	265	}
	266	else
	267	{
	268	have_ptrace_xmmregs = 0;
	269	#endif
	270	if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
	271	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	272	perror_with_name ("Couldn't get floating point status");
	273
	274	fill_fpregset (&fpregs, regno);
e6031aeb	275
7e89e357 JT	276	if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
	277	(PTRACE_ARG3_TYPE) &fpregs, 0) == -1)
	278	perror_with_name ("Couldn't write floating point status");
	279	#ifdef HAVE_PT_GETXMMREGS
	280	}
	281	#endif
e6031aeb MK	282	}
	283	}
	284	\f
	285
0afdd437 MK	286	/* Support for debug registers. */
	287
	288	#ifdef HAVE_PT_GETDBREGS
	289
	290	/* Not all versions of FreeBSD/i386 that support the debug registers
	291	have this macro. */
	292	#ifndef DBREG_DRX
	293	#define DBREG_DRX(d, x) ((&d->dr0)[x])
	294	#endif
	295
	296	static void
	297	i386bsd_dr_set (int regnum, unsigned int value)
	298	{
	299	struct dbreg dbregs;
	300
39f77062 KB	301	if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
39f77062 KB	302	(PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
0afdd437 MK	303	perror_with_name ("Couldn't get debug registers");
	304
	305	/* For some mysterious reason, some of the reserved bits in the
	306	debug control register get set. Mask these off, otherwise the
	307	ptrace call below will fail. */
	308	dbregs.dr7 &= ~(0x0000fc00);
	309
	310	DBREG_DRX ((&dbregs), regnum) = value;
	311
39f77062 KB	312	if (ptrace (PT_SETDBREGS, PIDGET (inferior_ptid),
39f77062 KB	313	(PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
0afdd437 MK	314	perror_with_name ("Couldn't write debug registers");
	315	}
	316
	317	void
	318	i386bsd_dr_set_control (unsigned long control)
	319	{
	320	i386bsd_dr_set (7, control);
	321	}
	322
	323	void
	324	i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
	325	{
	326	gdb_assert (regnum >= 0 && regnum <= 4);
	327
	328	i386bsd_dr_set (regnum, addr);
	329	}
	330
	331	void
	332	i386bsd_dr_reset_addr (int regnum)
	333	{
	334	gdb_assert (regnum >= 0 && regnum <= 4);
	335
	336	i386bsd_dr_set (regnum, 0);
	337	}
	338
	339	unsigned long
	340	i386bsd_dr_get_status (void)
	341	{
	342	struct dbreg dbregs;
	343
	344	/* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
	345	ptrace call fails breaks debugging remote targets. The correct
	346	way to fix this is to add the hardware breakpoint and watchpoint
b7247919	347	stuff to the target vector. For now, just return zero if the
0afdd437	348	ptrace call fails. */
39f77062 KB	349	if (ptrace (PT_GETDBREGS, PIDGET (inferior_ptid),
39f77062 KB	350	(PTRACE_ARG3_TYPE) & dbregs, 0) == -1)
0afdd437 MK	351	#if 0
	352	perror_with_name ("Couldn't read debug registers");
	353	#else
	354	return 0;
	355	#endif
	356
	357	return dbregs.dr6;
	358	}
	359
	360	#endif /* PT_GETDBREGS */
	361	\f
	362
e6031aeb MK	363	/* Support for the user struct. */
	364
	365	/* Return the address register REGNO. BLOCKEND is the value of
	366	u.u_ar0, which should point to the registers. */
	367
	368	CORE_ADDR
	369	register_u_addr (CORE_ADDR blockend, int regno)
	370	{
	371	return (CORE_ADDR) REG_ADDR (blockend, regno);
	372	}
	373
	374	#include <sys/param.h>
	375	#include <sys/user.h>
	376
	377	/* Return the size of the user struct. */
	378
	379	int
	380	kernel_u_size (void)
	381	{
	382	return (sizeof (struct user));
	383	}
b7247919 MK	384	\f
	385	/* See i386bsd-tdep.c. */
	386	extern int i386bsd_sigcontext_pc_offset;
	387
b7247919 MK	388	void
	389	_initialize_i386bsd_nat (void)
	390	{
	391	/* To support the recognition of signal handlers, i386bsd-tdep.c
	392	hardcodes some constants. Inclusion of this file means that we
	393	are compiling a native debugger, which means that we can use the
	394	system header files and sysctl(3) to get at the relevant
	395	information. */
	396
	397	/* Override the default value for the offset of the program counter
	398	in the sigcontext structure. */
	399	i386bsd_sigcontext_pc_offset = offsetof (struct sigcontext, sc_pc);
b7247919	400	}