[thirdparty/binutils-gdb.git] / gdb / ppcobsd-tdep.c

/* Target-dependent code for OpenBSD/powerpc.

   Copyright (C) 2004, 2005 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., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "defs.h"
#include "arch-utils.h"
#include "floatformat.h"
#include "frame.h"
#include "frame-unwind.h"
#include "osabi.h"
#include "regcache.h"
#include "regset.h"
#include "symtab.h"
#include "trad-frame.h"

#include "gdb_assert.h"
#include "gdb_string.h"

#include "ppc-tdep.h"
#include "ppcobsd-tdep.h"
#include "solib-svr4.h"

/* Register offsets from <machine/reg.h>.  */
struct ppc_reg_offsets ppcobsd_reg_offsets;
\f

/* Core file support.  */

/* Supply register REGNUM in the general-purpose register set REGSET
   from the buffer specified by GREGS and LEN to register cache
   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */

void
ppcobsd_supply_gregset (const struct regset *regset,
			struct regcache *regcache, int regnum,
			const void *gregs, size_t len)
{
  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
     point registers.  Traditionally, GDB's register set has still
     listed the floating point registers for such machines, so this
     code is harmless.  However, the new E500 port actually omits the
     floating point registers entirely from the register set --- they
     don't even have register numbers assigned to them.

     It's not clear to me how best to update this code, so this assert
     will alert the first person to encounter the OpenBSD/E500
     combination to the problem.  */
  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));

  ppc_supply_gregset (regset, regcache, regnum, gregs, len);
  ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
}

/* Collect register REGNUM in the general-purpose register set
   REGSET. from register cache REGCACHE into the buffer specified by
   GREGS and LEN.  If REGNUM is -1, do this for all registers in
   REGSET.  */

void
ppcobsd_collect_gregset (const struct regset *regset,
			 const struct regcache *regcache, int regnum,
			 void *gregs, size_t len)
{
  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
     point registers.  Traditionally, GDB's register set has still
     listed the floating point registers for such machines, so this
     code is harmless.  However, the new E500 port actually omits the
     floating point registers entirely from the register set --- they
     don't even have register numbers assigned to them.

     It's not clear to me how best to update this code, so this assert
     will alert the first person to encounter the OpenBSD/E500
     combination to the problem.  */
  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));

  ppc_collect_gregset (regset, regcache, regnum, gregs, len);
  ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
}

/* OpenBSD/powerpc register set.  */

struct regset ppcobsd_gregset =
{
  &ppcobsd_reg_offsets,
  ppcobsd_supply_gregset
};

/* Return the appropriate register set for the core section identified
   by SECT_NAME and SECT_SIZE.  */

static const struct regset *
ppcobsd_regset_from_core_section (struct gdbarch *gdbarch,
				  const char *sect_name, size_t sect_size)
{
  if (strcmp (sect_name, ".reg") == 0 && sect_size >= 412)
    return &ppcobsd_gregset;

  return NULL;
}
\f

/* Signal trampolines.  */

/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
   in virtual memory.  The randomness makes it somewhat tricky to
   detect it, but fortunately we can rely on the fact that the start
   of the sigtramp routine is page-aligned.  We recognize the
   trampoline by looking for the code that invokes the sigreturn
   system call.  The offset where we can find that code varies from
   release to release.

   By the way, the mapping mentioned above is read-only, so you cannot
   place a breakpoint in the signal trampoline.  */

/* Default page size.  */
static const int ppcobsd_page_size = 4096;

/* Offset for sigreturn(2).  */
static const int ppcobsd_sigreturn_offset[] = {
  0x98,				/* OpenBSD 3.8 */
  0x0c,				/* OpenBSD 3.2 */
  -1
};

static int
ppcobsd_sigtramp_p (struct frame_info *next_frame)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
  const int *offset;
  char *name;

  find_pc_partial_function (pc, &name, NULL, NULL);
  if (name)
    return 0;

  for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
    {
      gdb_byte buf[2 * PPC_INSN_SIZE];
      unsigned long insn;

      if (!safe_frame_unwind_memory (next_frame, start_pc + *offset,
				     buf, sizeof buf))
	continue;

      /* Check for "li r0,SYS_sigreturn".  */
      insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
      if (insn != 0x38000067)
	continue;

      /* Check for "sc".  */
      insn = extract_unsigned_integer (buf + PPC_INSN_SIZE, PPC_INSN_SIZE);
      if (insn != 0x44000002)
	continue;

      return 1;
    }

  return 0;
}

static struct trad_frame_cache *
ppcobsd_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
{
  struct gdbarch *gdbarch = get_frame_arch (next_frame);
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  struct trad_frame_cache *cache;
  CORE_ADDR addr, base, func;
  gdb_byte buf[PPC_INSN_SIZE];
  unsigned long insn, sigcontext_offset;
  int i;

  if (*this_cache)
    return *this_cache;

  cache = trad_frame_cache_zalloc (next_frame);
  *this_cache = cache;

  func = frame_pc_unwind (next_frame);
  func &= ~(ppcobsd_page_size - 1);
  if (!safe_frame_unwind_memory (next_frame, func, buf, sizeof buf))
    return cache;

  /* Calculate the offset where we can find `struct sigcontext'.  We
     base our calculation on the amount of stack space reserved by the
     first instruction of the signal trampoline.  */
  insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
  sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;

  base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
  addr = base + sigcontext_offset + 2 * tdep->wordsize;
  for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
    {
      int regnum = i + tdep->ppc_gp0_regnum;
      trad_frame_set_reg_addr (cache, regnum, addr);
    }
  trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
  addr += tdep->wordsize;
  trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
  addr += tdep->wordsize;
  trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
  addr += tdep->wordsize;
  trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
  addr += tdep->wordsize;
  trad_frame_set_reg_addr (cache, PC_REGNUM, addr); /* SRR0? */
  addr += tdep->wordsize;

  /* Construct the frame ID using the function start.  */
  trad_frame_set_id (cache, frame_id_build (base, func));

  return cache;
}

static void
ppcobsd_sigtramp_frame_this_id (struct frame_info *next_frame,
				void **this_cache, struct frame_id *this_id)
{
  struct trad_frame_cache *cache =
    ppcobsd_sigtramp_frame_cache (next_frame, this_cache);

  trad_frame_get_id (cache, this_id);
}

static void
ppcobsd_sigtramp_frame_prev_register (struct frame_info *next_frame,
				      void **this_cache, int regnum,
				      int *optimizedp, enum lval_type *lvalp,
				      CORE_ADDR *addrp, int *realnump,
				      gdb_byte *valuep)
{
  struct trad_frame_cache *cache =
    ppcobsd_sigtramp_frame_cache (next_frame, this_cache);

  trad_frame_get_register (cache, next_frame, regnum,
			   optimizedp, lvalp, addrp, realnump, valuep);
}

static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
  SIGTRAMP_FRAME,
  ppcobsd_sigtramp_frame_this_id,
  ppcobsd_sigtramp_frame_prev_register
};

static const struct frame_unwind *
ppcobsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
{
  if (ppcobsd_sigtramp_p (next_frame))
    return &ppcobsd_sigtramp_frame_unwind;

  return NULL;
}
\f

static void
ppcobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  /* OpenBSD doesn't support the 128-bit `long double' from the psABI.  */
  set_gdbarch_long_double_bit (gdbarch, 64);
  set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);

  /* OpenBSD currently uses a broken GCC.  */
  set_gdbarch_return_value (gdbarch, ppc_sysv_abi_broken_return_value);

  /* OpenBSD uses SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_ilp32_fetch_link_map_offsets);

  set_gdbarch_regset_from_core_section
    (gdbarch, ppcobsd_regset_from_core_section);

  frame_unwind_append_sniffer (gdbarch, ppcobsd_sigtramp_frame_sniffer);
}
\f

/* OpenBSD uses uses the traditional NetBSD core file format, even for
   ports that use ELF.  */
#define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF

static enum gdb_osabi
ppcobsd_core_osabi_sniffer (bfd *abfd)
{
  if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
    return GDB_OSABI_NETBSD_CORE;

  return GDB_OSABI_UNKNOWN;
}
\f

/* Provide a prototype to silence -Wmissing-prototypes.  */
void _initialize_ppcobsd_tdep (void);

void
_initialize_ppcobsd_tdep (void)
{
  /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
  gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
                                  ppcobsd_core_osabi_sniffer);

  gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
			  ppcobsd_init_abi);
  gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_OPENBSD_ELF,
			  ppcobsd_init_abi);

  /* Avoid initializing the register offsets again if they were
     already initailized by ppcobsd-nat.c.  */
  if (ppcobsd_reg_offsets.pc_offset == 0)
    {
      /* General-purpose registers.  */
      ppcobsd_reg_offsets.r0_offset = 0;
      ppcobsd_reg_offsets.pc_offset = 384;
      ppcobsd_reg_offsets.ps_offset = 388;
      ppcobsd_reg_offsets.cr_offset = 392;
      ppcobsd_reg_offsets.lr_offset = 396;
      ppcobsd_reg_offsets.ctr_offset = 400;
      ppcobsd_reg_offsets.xer_offset = 404;
      ppcobsd_reg_offsets.mq_offset = 408;

      /* Floating-point registers.  */
      ppcobsd_reg_offsets.f0_offset = 128;
      ppcobsd_reg_offsets.fpscr_offset = -1;

      /* AltiVec registers.  */
      ppcobsd_reg_offsets.vr0_offset = 0;
      ppcobsd_reg_offsets.vscr_offset = 512;
      ppcobsd_reg_offsets.vrsave_offset = 520;
    }
}
Commit	Line	Data
d195bc9f MK	1	/* Target-dependent code for OpenBSD/powerpc.
d195bc9f MK	2
197e01b6	3	Copyright (C) 2004, 2005 Free Software Foundation, Inc.
d195bc9f MK	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 2 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, write to the Free Software
197e01b6 EZ	19	Foundation, Inc., 51 Franklin Street, Fifth Floor,
197e01b6 EZ	20	Boston, MA 02110-1301, USA. */
d195bc9f MK	21
	22	#include "defs.h"
	23	#include "arch-utils.h"
5a49dfd0	24	#include "floatformat.h"
0dbe1904 MK	25	#include "frame.h"
0dbe1904 MK	26	#include "frame-unwind.h"
d195bc9f MK	27	#include "osabi.h"
	28	#include "regcache.h"
	29	#include "regset.h"
0dbe1904	30	#include "symtab.h"
18b2ae85	31	#include "trad-frame.h"
d195bc9f	32
18b2ae85	33	#include "gdb_assert.h"
d195bc9f MK	34	#include "gdb_string.h"
	35
	36	#include "ppc-tdep.h"
	37	#include "ppcobsd-tdep.h"
	38	#include "solib-svr4.h"
	39
	40	/* Register offsets from <machine/reg.h>. */
	41	struct ppc_reg_offsets ppcobsd_reg_offsets;
	42	\f
	43
	44	/* Core file support. */
	45
	46	/* Supply register REGNUM in the general-purpose register set REGSET
	47	from the buffer specified by GREGS and LEN to register cache
	48	REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
	49
	50	void
	51	ppcobsd_supply_gregset (const struct regset *regset,
	52	struct regcache *regcache, int regnum,
	53	const void *gregs, size_t len)
	54	{
383f0f5b JB	55	/* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
	56	point registers. Traditionally, GDB's register set has still
	57	listed the floating point registers for such machines, so this
	58	code is harmless. However, the new E500 port actually omits the
	59	floating point registers entirely from the register set --- they
	60	don't even have register numbers assigned to them.
	61
	62	It's not clear to me how best to update this code, so this assert
	63	will alert the first person to encounter the OpenBSD/E500
	64	combination to the problem. */
	65	gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
	66
d195bc9f MK	67	ppc_supply_gregset (regset, regcache, regnum, gregs, len);
	68	ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
	69	}
	70
	71	/* Collect register REGNUM in the general-purpose register set
	72	REGSET. from register cache REGCACHE into the buffer specified by
	73	GREGS and LEN. If REGNUM is -1, do this for all registers in
	74	REGSET. */
	75
	76	void
	77	ppcobsd_collect_gregset (const struct regset *regset,
	78	const struct regcache *regcache, int regnum,
	79	void *gregs, size_t len)
	80	{
383f0f5b JB	81	/* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
	82	point registers. Traditionally, GDB's register set has still
	83	listed the floating point registers for such machines, so this
	84	code is harmless. However, the new E500 port actually omits the
	85	floating point registers entirely from the register set --- they
	86	don't even have register numbers assigned to them.
	87
	88	It's not clear to me how best to update this code, so this assert
	89	will alert the first person to encounter the OpenBSD/E500
	90	combination to the problem. */
	91	gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
	92
d195bc9f MK	93	ppc_collect_gregset (regset, regcache, regnum, gregs, len);
	94	ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
	95	}
	96
5d6210f0	97	/* OpenBSD/powerpc register set. */
d195bc9f MK	98
	99	struct regset ppcobsd_gregset =
	100	{
	101	&ppcobsd_reg_offsets,
	102	ppcobsd_supply_gregset
	103	};
	104
	105	/* Return the appropriate register set for the core section identified
	106	by SECT_NAME and SECT_SIZE. */
	107
	108	static const struct regset *
	109	ppcobsd_regset_from_core_section (struct gdbarch *gdbarch,
	110	const char *sect_name, size_t sect_size)
	111	{
	112	if (strcmp (sect_name, ".reg") == 0 && sect_size >= 412)
	113	return &ppcobsd_gregset;
	114
	115	return NULL;
	116	}
	117	\f
	118
18b2ae85 MK	119	/* Signal trampolines. */
18b2ae85 MK	120
0dbe1904 MK	121	/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
	122	in virtual memory. The randomness makes it somewhat tricky to
	123	detect it, but fortunately we can rely on the fact that the start
	124	of the sigtramp routine is page-aligned. We recognize the
	125	trampoline by looking for the code that invokes the sigreturn
	126	system call. The offset where we can find that code varies from
	127	release to release.
	128
	129	By the way, the mapping mentioned above is read-only, so you cannot
	130	place a breakpoint in the signal trampoline. */
	131
	132	/* Default page size. */
	133	static const int ppcobsd_page_size = 4096;
	134
	135	/* Offset for sigreturn(2). */
	136	static const int ppcobsd_sigreturn_offset[] = {
	137	0x98, /* OpenBSD 3.8 */
	138	0x0c, /* OpenBSD 3.2 */
	139	-1
	140	};
	141
	142	static int
	143	ppcobsd_sigtramp_p (struct frame_info *next_frame)
	144	{
	145	CORE_ADDR pc = frame_pc_unwind (next_frame);
	146	CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
	147	const int *offset;
	148	char *name;
	149
	150	find_pc_partial_function (pc, &name, NULL, NULL);
	151	if (name)
	152	return 0;
	153
	154	for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
	155	{
	156	gdb_byte buf[2 * PPC_INSN_SIZE];
	157	unsigned long insn;
	158
	159	if (!safe_frame_unwind_memory (next_frame, start_pc + *offset,
	160	buf, sizeof buf))
	161	continue;
	162
	163	/* Check for "li r0,SYS_sigreturn". */
	164	insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
	165	if (insn != 0x38000067)
	166	continue;
	167
	168	/* Check for "sc". */
	169	insn = extract_unsigned_integer (buf + PPC_INSN_SIZE, PPC_INSN_SIZE);
	170	if (insn != 0x44000002)
	171	continue;
	172
	173	return 1;
	174	}
	175
	176	return 0;
	177	}
	178
	179	static struct trad_frame_cache *
	180	ppcobsd_sigtramp_frame_cache (struct frame_info next_frame, void *this_cache)
18b2ae85 MK	181	{
	182	struct gdbarch *gdbarch = get_frame_arch (next_frame);
	183	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
0dbe1904 MK	184	struct trad_frame_cache *cache;
	185	CORE_ADDR addr, base, func;
	186	gdb_byte buf[PPC_INSN_SIZE];
	187	unsigned long insn, sigcontext_offset;
18b2ae85 MK	188	int i;
18b2ae85 MK	189
0dbe1904 MK	190	if (*this_cache)
	191	return *this_cache;
	192
	193	cache = trad_frame_cache_zalloc (next_frame);
	194	*this_cache = cache;
	195
	196	func = frame_pc_unwind (next_frame);
	197	func &= ~(ppcobsd_page_size - 1);
	198	if (!safe_frame_unwind_memory (next_frame, func, buf, sizeof buf))
	199	return cache;
	200
	201	/* Calculate the offset where we can find `struct sigcontext'. We
	202	base our calculation on the amount of stack space reserved by the
	203	first instruction of the signal trampoline. */
	204	insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
	205	sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
	206
18b2ae85	207	base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
0dbe1904	208	addr = base + sigcontext_offset + 2 * tdep->wordsize;
18b2ae85 MK	209	for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
	210	{
	211	int regnum = i + tdep->ppc_gp0_regnum;
0dbe1904	212	trad_frame_set_reg_addr (cache, regnum, addr);
18b2ae85	213	}
0dbe1904	214	trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
18b2ae85	215	addr += tdep->wordsize;
0dbe1904	216	trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
18b2ae85	217	addr += tdep->wordsize;
0dbe1904	218	trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
18b2ae85	219	addr += tdep->wordsize;
0dbe1904	220	trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
18b2ae85	221	addr += tdep->wordsize;
0dbe1904	222	trad_frame_set_reg_addr (cache, PC_REGNUM, addr); /* SRR0? */
18b2ae85 MK	223	addr += tdep->wordsize;
	224
	225	/* Construct the frame ID using the function start. */
0dbe1904 MK	226	trad_frame_set_id (cache, frame_id_build (base, func));
	227
	228	return cache;
18b2ae85 MK	229	}
18b2ae85 MK	230
0dbe1904 MK	231	static void
	232	ppcobsd_sigtramp_frame_this_id (struct frame_info *next_frame,
	233	void *this_cache, struct frame_id this_id)
	234	{
	235	struct trad_frame_cache *cache =
	236	ppcobsd_sigtramp_frame_cache (next_frame, this_cache);
	237
	238	trad_frame_get_id (cache, this_id);
	239	}
	240
	241	static void
	242	ppcobsd_sigtramp_frame_prev_register (struct frame_info *next_frame,
	243	void **this_cache, int regnum,
	244	int optimizedp, enum lval_type lvalp,
	245	CORE_ADDR addrp, int realnump,
	246	gdb_byte *valuep)
18b2ae85	247	{
0dbe1904 MK	248	struct trad_frame_cache *cache =
	249	ppcobsd_sigtramp_frame_cache (next_frame, this_cache);
	250
	251	trad_frame_get_register (cache, next_frame, regnum,
	252	optimizedp, lvalp, addrp, realnump, valuep);
	253	}
	254
	255	static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
18b2ae85	256	SIGTRAMP_FRAME,
0dbe1904 MK	257	ppcobsd_sigtramp_frame_this_id,
0dbe1904 MK	258	ppcobsd_sigtramp_frame_prev_register
18b2ae85	259	};
0dbe1904 MK	260
	261	static const struct frame_unwind *
	262	ppcobsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
	263	{
	264	if (ppcobsd_sigtramp_p (next_frame))
	265	return &ppcobsd_sigtramp_frame_unwind;
	266
	267	return NULL;
	268	}
18b2ae85	269	\f
5d6210f0	270
d195bc9f MK	271	static void
	272	ppcobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	273	{
5a49dfd0 MK	274	/* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
	275	set_gdbarch_long_double_bit (gdbarch, 64);
	276	set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
	277
a86c5ab2 MK	278	/* OpenBSD currently uses a broken GCC. */
	279	set_gdbarch_return_value (gdbarch, ppc_sysv_abi_broken_return_value);
	280
d195bc9f	281	/* OpenBSD uses SVR4-style shared libraries. */
d195bc9f MK	282	set_solib_svr4_fetch_link_map_offsets
	283	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
	284
	285	set_gdbarch_regset_from_core_section
	286	(gdbarch, ppcobsd_regset_from_core_section);
18b2ae85	287
0dbe1904	288	frame_unwind_append_sniffer (gdbarch, ppcobsd_sigtramp_frame_sniffer);
d195bc9f MK	289	}
	290	\f
	291
	292	/* OpenBSD uses uses the traditional NetBSD core file format, even for
	293	ports that use ELF. */
	294	#define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
	295
	296	static enum gdb_osabi
	297	ppcobsd_core_osabi_sniffer (bfd *abfd)
	298	{
	299	if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
	300	return GDB_OSABI_NETBSD_CORE;
	301
	302	return GDB_OSABI_UNKNOWN;
	303	}
	304	\f
	305
	306	/* Provide a prototype to silence -Wmissing-prototypes. */
	307	void _initialize_ppcobsd_tdep (void);
	308
	309	void
	310	_initialize_ppcobsd_tdep (void)
	311	{
	312	/* BFD doesn't set a flavour for NetBSD style a.out core files. */
	313	gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
	314	ppcobsd_core_osabi_sniffer);
	315
5d6210f0 MK	316	gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
5d6210f0 MK	317	ppcobsd_init_abi);
d195bc9f MK	318	gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_OPENBSD_ELF,
	319	ppcobsd_init_abi);
	320
	321	/* Avoid initializing the register offsets again if they were
	322	already initailized by ppcobsd-nat.c. */
	323	if (ppcobsd_reg_offsets.pc_offset == 0)
	324	{
	325	/* General-purpose registers. */
	326	ppcobsd_reg_offsets.r0_offset = 0;
	327	ppcobsd_reg_offsets.pc_offset = 384;
	328	ppcobsd_reg_offsets.ps_offset = 388;
	329	ppcobsd_reg_offsets.cr_offset = 392;
	330	ppcobsd_reg_offsets.lr_offset = 396;
	331	ppcobsd_reg_offsets.ctr_offset = 400;
	332	ppcobsd_reg_offsets.xer_offset = 404;
	333	ppcobsd_reg_offsets.mq_offset = 408;
	334
	335	/* Floating-point registers. */
	336	ppcobsd_reg_offsets.f0_offset = 128;
	337	ppcobsd_reg_offsets.fpscr_offset = -1;
	338
	339	/* AltiVec registers. */
	340	ppcobsd_reg_offsets.vr0_offset = 0;
	341	ppcobsd_reg_offsets.vscr_offset = 512;
	342	ppcobsd_reg_offsets.vrsave_offset = 520;
	343	}
	344	}