[thirdparty/binutils-gdb.git] / gdb / xtensa-linux-nat.c

/* Xtensa GNU/Linux native support.

   Copyright (C) 2007-2014 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 <string.h>
#include "frame.h"
#include "inferior.h"
#include "gdbcore.h"
#include "regcache.h"
#include "gdb_assert.h"
#include "target.h"
#include "linux-nat.h"

#include <stdint.h>
#include <sys/types.h>
#include <signal.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include "gdb_wait.h"
#include <fcntl.h>
#include <sys/procfs.h>
#include <sys/ptrace.h>

#include "gregset.h"
#include "xtensa-tdep.h"

/* Extended register set depends on hardware configs.
   Keeping these definitions separately allows to introduce
   hardware-specific overlays.  */
#include "xtensa-xtregs.c"

static int
get_thread_id (ptid_t ptid)
{
  int tid = ptid_get_lwp (ptid);
  if (0 == tid)
    tid = ptid_get_pid (ptid);
  return tid;
}
#define GET_THREAD_ID(PTID)	get_thread_id (PTID)

void
fill_gregset (const struct regcache *regcache,
	      gdb_gregset_t *gregsetp, int regnum)
{
  int i;
  xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
  struct gdbarch *gdbarch = get_regcache_arch (regcache);

  if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
    regcache_raw_collect (regcache, gdbarch_pc_regnum (gdbarch), &regs->pc);
  if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
    regcache_raw_collect (regcache, gdbarch_ps_regnum (gdbarch), &regs->ps);

  if (regnum == gdbarch_tdep (gdbarch)->wb_regnum || regnum == -1)
    regcache_raw_collect (regcache,
			  gdbarch_tdep (gdbarch)->wb_regnum,
			  &regs->windowbase);
  if (regnum == gdbarch_tdep (gdbarch)->ws_regnum || regnum == -1)
    regcache_raw_collect (regcache,
			  gdbarch_tdep (gdbarch)->ws_regnum,
			  &regs->windowstart);
  if (regnum == gdbarch_tdep (gdbarch)->lbeg_regnum || regnum == -1)
    regcache_raw_collect (regcache,
			  gdbarch_tdep (gdbarch)->lbeg_regnum,
			  &regs->lbeg);
  if (regnum == gdbarch_tdep (gdbarch)->lend_regnum || regnum == -1)
    regcache_raw_collect (regcache,
			  gdbarch_tdep (gdbarch)->lend_regnum,
			  &regs->lend);
  if (regnum == gdbarch_tdep (gdbarch)->lcount_regnum || regnum == -1)
    regcache_raw_collect (regcache,
			  gdbarch_tdep (gdbarch)->lcount_regnum,
			  &regs->lcount);
  if (regnum == gdbarch_tdep (gdbarch)->sar_regnum || regnum == -1)
    regcache_raw_collect (regcache,
			  gdbarch_tdep (gdbarch)->sar_regnum,
			  &regs->sar);
  if (regnum >=gdbarch_tdep (gdbarch)->ar_base
      && regnum < gdbarch_tdep (gdbarch)->ar_base
		    + gdbarch_tdep (gdbarch)->num_aregs)
    regcache_raw_collect (regcache,regnum,
			  &regs->ar[regnum - gdbarch_tdep (gdbarch)->ar_base]);
  else if (regnum == -1)
    {
      for (i = 0; i < gdbarch_tdep (gdbarch)->num_aregs; ++i)
	regcache_raw_collect (regcache,
			      gdbarch_tdep (gdbarch)->ar_base + i,
			      &regs->ar[i]);
    }
}

void
supply_gregset_reg (struct regcache *regcache,
		    const gdb_gregset_t *gregsetp, int regnum)
{
  int i;
  xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;

  struct gdbarch *gdbarch = get_regcache_arch (regcache);

  if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
    regcache_raw_supply (regcache, gdbarch_pc_regnum (gdbarch), &regs->pc);
  if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
    regcache_raw_supply (regcache, gdbarch_ps_regnum (gdbarch), &regs->ps);

  if (regnum == gdbarch_tdep (gdbarch)->wb_regnum || regnum == -1)
    regcache_raw_supply (regcache,
			  gdbarch_tdep (gdbarch)->wb_regnum,
			  &regs->windowbase);
  if (regnum == gdbarch_tdep (gdbarch)->ws_regnum || regnum == -1)
    regcache_raw_supply (regcache,
			  gdbarch_tdep (gdbarch)->ws_regnum,
			  &regs->windowstart);
  if (regnum == gdbarch_tdep (gdbarch)->lbeg_regnum || regnum == -1)
    regcache_raw_supply (regcache,
			  gdbarch_tdep (gdbarch)->lbeg_regnum,
			  &regs->lbeg);
  if (regnum == gdbarch_tdep (gdbarch)->lend_regnum || regnum == -1)
    regcache_raw_supply (regcache,
			  gdbarch_tdep (gdbarch)->lend_regnum,
			  &regs->lend);
  if (regnum == gdbarch_tdep (gdbarch)->lcount_regnum || regnum == -1)
    regcache_raw_supply (regcache,
			  gdbarch_tdep (gdbarch)->lcount_regnum,
			  &regs->lcount);
  if (regnum == gdbarch_tdep (gdbarch)->sar_regnum || regnum == -1)
    regcache_raw_supply (regcache,
			  gdbarch_tdep (gdbarch)->sar_regnum,
			  &regs->sar);
  if (regnum >=gdbarch_tdep (gdbarch)->ar_base
      && regnum < gdbarch_tdep (gdbarch)->ar_base
		    + gdbarch_tdep (gdbarch)->num_aregs)
    regcache_raw_supply (regcache,regnum,
			  &regs->ar[regnum - gdbarch_tdep (gdbarch)->ar_base]);
  else if (regnum == -1)
    {
      for (i = 0; i < gdbarch_tdep (gdbarch)->num_aregs; ++i)
	regcache_raw_supply (regcache,
			      gdbarch_tdep (gdbarch)->ar_base + i,
			      &regs->ar[i]);
    }
}

void
supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
{
  supply_gregset_reg (regcache, gregsetp, -1);
}

void
fill_fpregset (const struct regcache *regcache,
	       gdb_fpregset_t *fpregsetp, int regnum)
{
  return;
}

void 
supply_fpregset (struct regcache *regcache,
		 const gdb_fpregset_t *fpregsetp)
{
  return;
}

/* Fetch greg-register(s) from process/thread TID
   and store value(s) in GDB's register array.  */

static void
fetch_gregs (struct regcache *regcache, int regnum)
{
  int tid = GET_THREAD_ID (inferior_ptid);
  const gdb_gregset_t regs;
  int areg;
  
  if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
    {
      perror_with_name (_("Couldn't get registers"));
      return;
    }
 
  supply_gregset_reg (regcache, &regs, regnum);
}

/* Store greg-register(s) in GDB's register 
   array into the process/thread specified by TID.  */

static void
store_gregs (struct regcache *regcache, int regnum)
{
  int tid = GET_THREAD_ID (inferior_ptid);
  gdb_gregset_t regs;
  int areg;

  if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
    {
      perror_with_name (_("Couldn't get registers"));
      return;
    }

  fill_gregset (regcache, &regs, regnum);

  if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
    {
      perror_with_name (_("Couldn't write registers"));
      return;
    }
}

static int xtreg_lo;
static int xtreg_high;

/* Fetch/Store Xtensa TIE registers.  Xtensa GNU/Linux PTRACE
   interface provides special requests for this.  */

static void
fetch_xtregs (struct regcache *regcache, int regnum)
{
  int tid = GET_THREAD_ID (inferior_ptid);
  const xtensa_regtable_t *ptr;
  char xtregs [XTENSA_ELF_XTREG_SIZE];

  if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
    perror_with_name (_("Couldn't get extended registers"));

  for (ptr = xtensa_regmap_table; ptr->name; ptr++)
    if (regnum == ptr->gdb_regnum || regnum == -1)
      regcache_raw_supply (regcache, ptr->gdb_regnum,
			   xtregs + ptr->ptrace_offset);
}

static void
store_xtregs (struct regcache *regcache, int regnum)
{
  int tid = GET_THREAD_ID (inferior_ptid);
  const xtensa_regtable_t *ptr;
  char xtregs [XTENSA_ELF_XTREG_SIZE];

  if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
    perror_with_name (_("Couldn't get extended registers"));

  for (ptr = xtensa_regmap_table; ptr->name; ptr++)
    if (regnum == ptr->gdb_regnum || regnum == -1)
      regcache_raw_collect (regcache, ptr->gdb_regnum,
			    xtregs + ptr->ptrace_offset);

  if (ptrace (PTRACE_SETXTREGS, tid, 0, (long)&xtregs) < 0)
    perror_with_name (_("Couldn't write extended registers"));
}

void
xtensa_linux_fetch_inferior_registers (struct target_ops *ops,
				       struct regcache *regcache, int regnum)
{
  if (regnum == -1)
    {
      fetch_gregs (regcache, regnum);
      fetch_xtregs (regcache, regnum);
    }
  else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
    fetch_gregs (regcache, regnum);
  else
    fetch_xtregs (regcache, regnum);
}

void
xtensa_linux_store_inferior_registers (struct target_ops *ops,
				       struct regcache *regcache, int regnum)
{
  if (regnum == -1)
    {
      store_gregs (regcache, regnum);
      store_xtregs (regcache, regnum);
    }
  else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
    store_gregs (regcache, regnum);
  else
    store_xtregs (regcache, regnum);
}

void _initialize_xtensa_linux_nat (void);

void
_initialize_xtensa_linux_nat (void)
{
  struct target_ops *t;
  const xtensa_regtable_t *ptr;

  /* Calculate the number range for extended registers.  */
  xtreg_lo = 1000000000;
  xtreg_high = -1;
  for (ptr = xtensa_regmap_table; ptr->name; ptr++)
    {
      if (ptr->gdb_regnum < xtreg_lo)
	xtreg_lo = ptr->gdb_regnum;
      if (ptr->gdb_regnum > xtreg_high)
	xtreg_high = ptr->gdb_regnum;
    }

  /* Fill in the generic GNU/Linux methods.  */
  t = linux_target ();

  /* Add our register access methods.  */
  t->to_fetch_registers = xtensa_linux_fetch_inferior_registers;
  t->to_store_registers = xtensa_linux_store_inferior_registers;

  linux_nat_add_target (t);
}
Commit	Line	Data
94a0e877 MG	1	/* Xtensa GNU/Linux native support.
94a0e877 MG	2
ecd75fc8	3	Copyright (C) 2007-2014 Free Software Foundation, Inc.
94a0e877 MG	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"
0e9f083f	21	#include <string.h>
94a0e877 MG	22	#include "frame.h"
	23	#include "inferior.h"
	24	#include "gdbcore.h"
	25	#include "regcache.h"
	26	#include "gdb_assert.h"
	27	#include "target.h"
	28	#include "linux-nat.h"
	29
	30	#include <stdint.h>
	31	#include <sys/types.h>
94a0e877 MG	32	#include <signal.h>
	33	#include <sys/user.h>
	34	#include <sys/ioctl.h>
	35	#include "gdb_wait.h"
	36	#include <fcntl.h>
	37	#include <sys/procfs.h>
	38	#include <sys/ptrace.h>
	39
	40	#include "gregset.h"
	41	#include "xtensa-tdep.h"
	42
	43	/* Extended register set depends on hardware configs.
	44	Keeping these definitions separately allows to introduce
	45	hardware-specific overlays. */
	46	#include "xtensa-xtregs.c"
	47
4e841acf	48	static int
94a0e877 MG	49	get_thread_id (ptid_t ptid)
94a0e877 MG	50	{
dfd4cc63	51	int tid = ptid_get_lwp (ptid);
94a0e877	52	if (0 == tid)
dfd4cc63	53	tid = ptid_get_pid (ptid);
94a0e877 MG	54	return tid;
	55	}
	56	#define GET_THREAD_ID(PTID) get_thread_id (PTID)
	57
	58	void
	59	fill_gregset (const struct regcache *regcache,
	60	gdb_gregset_t *gregsetp, int regnum)
	61	{
	62	int i;
	63	xtensa_elf_gregset_t regs = (xtensa_elf_gregset_t ) gregsetp;
	64	struct gdbarch *gdbarch = get_regcache_arch (regcache);
	65
	66	if (regnum == gdbarch_pc_regnum (gdbarch) \|\| regnum == -1)
	67	regcache_raw_collect (regcache, gdbarch_pc_regnum (gdbarch), &regs->pc);
	68	if (regnum == gdbarch_ps_regnum (gdbarch) \|\| regnum == -1)
	69	regcache_raw_collect (regcache, gdbarch_ps_regnum (gdbarch), &regs->ps);
	70
	71	if (regnum == gdbarch_tdep (gdbarch)->wb_regnum \|\| regnum == -1)
	72	regcache_raw_collect (regcache,
	73	gdbarch_tdep (gdbarch)->wb_regnum,
	74	&regs->windowbase);
	75	if (regnum == gdbarch_tdep (gdbarch)->ws_regnum \|\| regnum == -1)
	76	regcache_raw_collect (regcache,
	77	gdbarch_tdep (gdbarch)->ws_regnum,
	78	&regs->windowstart);
	79	if (regnum == gdbarch_tdep (gdbarch)->lbeg_regnum \|\| regnum == -1)
	80	regcache_raw_collect (regcache,
	81	gdbarch_tdep (gdbarch)->lbeg_regnum,
	82	&regs->lbeg);
	83	if (regnum == gdbarch_tdep (gdbarch)->lend_regnum \|\| regnum == -1)
	84	regcache_raw_collect (regcache,
	85	gdbarch_tdep (gdbarch)->lend_regnum,
	86	&regs->lend);
	87	if (regnum == gdbarch_tdep (gdbarch)->lcount_regnum \|\| regnum == -1)
	88	regcache_raw_collect (regcache,
	89	gdbarch_tdep (gdbarch)->lcount_regnum,
	90	&regs->lcount);
	91	if (regnum == gdbarch_tdep (gdbarch)->sar_regnum \|\| regnum == -1)
	92	regcache_raw_collect (regcache,
	93	gdbarch_tdep (gdbarch)->sar_regnum,
	94	&regs->sar);
	95	if (regnum >=gdbarch_tdep (gdbarch)->ar_base
	96	&& regnum < gdbarch_tdep (gdbarch)->ar_base
	97	+ gdbarch_tdep (gdbarch)->num_aregs)
	98	regcache_raw_collect (regcache,regnum,
	99	&regs->ar[regnum - gdbarch_tdep (gdbarch)->ar_base]);
	100	else if (regnum == -1)
	101	{
	102	for (i = 0; i < gdbarch_tdep (gdbarch)->num_aregs; ++i)
	103	regcache_raw_collect (regcache,
	104	gdbarch_tdep (gdbarch)->ar_base + i,
	105	&regs->ar[i]);
	106	}
	107	}
	108
	109	void
	110	supply_gregset_reg (struct regcache *regcache,
	111	const gdb_gregset_t *gregsetp, int regnum)
	112	{
	113	int i;
	114	xtensa_elf_gregset_t regs = (xtensa_elf_gregset_t ) gregsetp;
	115
	116	struct gdbarch *gdbarch = get_regcache_arch (regcache);
	117
118	if (regnum == gdbarch_pc_regnum (gdbarch) \|\| regnum == -1)
119	regcache_raw_supply (regcache, gdbarch_pc_regnum (gdbarch), &regs->pc);
120	if (regnum == gdbarch_ps_regnum (gdbarch) \|\| regnum == -1)
121	regcache_raw_supply (regcache, gdbarch_ps_regnum (gdbarch), &regs->ps);
122
123	if (regnum == gdbarch_tdep (gdbarch)->wb_regnum \|\| regnum == -1)
124	regcache_raw_supply (regcache,
125	gdbarch_tdep (gdbarch)->wb_regnum,
126	&regs->windowbase);
127	if (regnum == gdbarch_tdep (gdbarch)->ws_regnum \|\| regnum == -1)
128	regcache_raw_supply (regcache,
129	gdbarch_tdep (gdbarch)->ws_regnum,
130	&regs->windowstart);
131	if (regnum == gdbarch_tdep (gdbarch)->lbeg_regnum \|\| regnum == -1)
132	regcache_raw_supply (regcache,
133	gdbarch_tdep (gdbarch)->lbeg_regnum,
134	&regs->lbeg);
135	if (regnum == gdbarch_tdep (gdbarch)->lend_regnum \|\| regnum == -1)
136	regcache_raw_supply (regcache,
137	gdbarch_tdep (gdbarch)->lend_regnum,
138	&regs->lend);
139	if (regnum == gdbarch_tdep (gdbarch)->lcount_regnum \|\| regnum == -1)
140	regcache_raw_supply (regcache,
141	gdbarch_tdep (gdbarch)->lcount_regnum,
142	&regs->lcount);
143	if (regnum == gdbarch_tdep (gdbarch)->sar_regnum \|\| regnum == -1)
144	regcache_raw_supply (regcache,
145	gdbarch_tdep (gdbarch)->sar_regnum,
146	&regs->sar);
147	if (regnum >=gdbarch_tdep (gdbarch)->ar_base
148	&& regnum < gdbarch_tdep (gdbarch)->ar_base
149	+ gdbarch_tdep (gdbarch)->num_aregs)
150	regcache_raw_supply (regcache,regnum,
151	&regs->ar[regnum - gdbarch_tdep (gdbarch)->ar_base]);
152	else if (regnum == -1)
153	{
154	for (i = 0; i < gdbarch_tdep (gdbarch)->num_aregs; ++i)
155	regcache_raw_supply (regcache,
156	gdbarch_tdep (gdbarch)->ar_base + i,
157	&regs->ar[i]);
158	}
159	}
160
161	void
162	supply_gregset (struct regcache regcache, const gdb_gregset_t gregsetp)
163	{
164	supply_gregset_reg (regcache, gregsetp, -1);
165	}
166
167	void
168	fill_fpregset (const struct regcache *regcache,
169	gdb_fpregset_t *fpregsetp, int regnum)
170	{
171	return;
172	}
173
174	void
175	supply_fpregset (struct regcache *regcache,
176	const gdb_fpregset_t *fpregsetp)
177	{
178	return;
179	}
180
181	/* Fetch greg-register(s) from process/thread TID
182	and store value(s) in GDB's register array. */
183
184	static void
185	fetch_gregs (struct regcache *regcache, int regnum)
186	{
187	int tid = GET_THREAD_ID (inferior_ptid);
188	const gdb_gregset_t regs;
189	int areg;
190
191	if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
192	{
193	perror_with_name (_("Couldn't get registers"));
194	return;
195	}
196
197	supply_gregset_reg (regcache, &regs, regnum);
198	}
199
200	/* Store greg-register(s) in GDB's register
201	array into the process/thread specified by TID. */
202
203	static void
204	store_gregs (struct regcache *regcache, int regnum)
205	{
206	int tid = GET_THREAD_ID (inferior_ptid);
207	gdb_gregset_t regs;
208	int areg;
209
210	if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
211	{
212	perror_with_name (_("Couldn't get registers"));
213	return;
214	}
215
216	fill_gregset (regcache, &regs, regnum);
217
218	if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
219	{
220	perror_with_name (_("Couldn't write registers"));
221	return;
222	}
223	}
224
225	static int xtreg_lo;
226	static int xtreg_high;
227
228	/* Fetch/Store Xtensa TIE registers. Xtensa GNU/Linux PTRACE
229	interface provides special requests for this. */
230
231	static void
232	fetch_xtregs (struct regcache *regcache, int regnum)
233	{
234	int tid = GET_THREAD_ID (inferior_ptid);
235	const xtensa_regtable_t *ptr;
236	char xtregs [XTENSA_ELF_XTREG_SIZE];
237
238	if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
239	perror_with_name (_("Couldn't get extended registers"));
240
241	for (ptr = xtensa_regmap_table; ptr->name; ptr++)
242	if (regnum == ptr->gdb_regnum \|\| regnum == -1)
243	regcache_raw_supply (regcache, ptr->gdb_regnum,
244	xtregs + ptr->ptrace_offset);
245	}
246
247	static void
248	store_xtregs (struct regcache *regcache, int regnum)
249	{
250	int tid = GET_THREAD_ID (inferior_ptid);
251	const xtensa_regtable_t *ptr;
252	char xtregs [XTENSA_ELF_XTREG_SIZE];
253
254	if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
255	perror_with_name (_("Couldn't get extended registers"));
256
257	for (ptr = xtensa_regmap_table; ptr->name; ptr++)
258	if (regnum == ptr->gdb_regnum \|\| regnum == -1)
259	regcache_raw_collect (regcache, ptr->gdb_regnum,
260	xtregs + ptr->ptrace_offset);
261
262	if (ptrace (PTRACE_SETXTREGS, tid, 0, (long)&xtregs) < 0)
263	perror_with_name (_("Couldn't write extended registers"));
264	}
265
266	void
28439f5e PA	267	xtensa_linux_fetch_inferior_registers (struct target_ops *ops,
28439f5e PA	268	struct regcache *regcache, int regnum)
94a0e877 MG	269	{
	270	if (regnum == -1)
	271	{
	272	fetch_gregs (regcache, regnum);
	273	fetch_xtregs (regcache, regnum);
	274	}
	275	else if ((regnum < xtreg_lo) \|\| (regnum > xtreg_high))
	276	fetch_gregs (regcache, regnum);
	277	else
	278	fetch_xtregs (regcache, regnum);
	279	}
	280
	281	void
28439f5e PA	282	xtensa_linux_store_inferior_registers (struct target_ops *ops,
28439f5e PA	283	struct regcache *regcache, int regnum)
94a0e877 MG	284	{
	285	if (regnum == -1)
	286	{
	287	store_gregs (regcache, regnum);
	288	store_xtregs (regcache, regnum);
	289	}
	290	else if ((regnum < xtreg_lo) \|\| (regnum > xtreg_high))
	291	store_gregs (regcache, regnum);
	292	else
	293	store_xtregs (regcache, regnum);
	294	}
	295
	296	void _initialize_xtensa_linux_nat (void);
	297
	298	void
	299	_initialize_xtensa_linux_nat (void)
	300	{
	301	struct target_ops *t;
	302	const xtensa_regtable_t *ptr;
	303
	304	/* Calculate the number range for extended registers. */
	305	xtreg_lo = 1000000000;
	306	xtreg_high = -1;
	307	for (ptr = xtensa_regmap_table; ptr->name; ptr++)
	308	{
	309	if (ptr->gdb_regnum < xtreg_lo)
	310	xtreg_lo = ptr->gdb_regnum;
	311	if (ptr->gdb_regnum > xtreg_high)
	312	xtreg_high = ptr->gdb_regnum;
	313	}
	314
	315	/* Fill in the generic GNU/Linux methods. */
	316	t = linux_target ();
	317
	318	/* Add our register access methods. */
	319	t->to_fetch_registers = xtensa_linux_fetch_inferior_registers;
	320	t->to_store_registers = xtensa_linux_store_inferior_registers;
	321
	322	linux_nat_add_target (t);
	323	}