[deliverable/binutils-gdb.git] / gdb / mipsnbsd-tdep.c

/* Target-dependent code for NetBSD/mips.

   Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.

   Contributed by Wasabi Systems, 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 "gdbcore.h"
#include "regcache.h"
#include "regset.h"
#include "target.h"
#include "value.h"
#include "osabi.h"

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

#include "nbsd-tdep.h"
#include "mipsnbsd-tdep.h"
#include "mips-tdep.h"

#include "solib-svr4.h"

/* Shorthand for some register numbers used below.  */
#define MIPS_PC_REGNUM  MIPS_EMBED_PC_REGNUM
#define MIPS_FP0_REGNUM MIPS_EMBED_FP0_REGNUM
#define MIPS_FSR_REGNUM MIPS_EMBED_FP0_REGNUM + 32

/* Core file support.  */

/* Number of registers in `struct reg' from <machine/reg.h>.  */
#define MIPSNBSD_NUM_GREGS	38

/* Number of registers in `struct fpreg' from <machine/reg.h>.  */
#define MIPSNBSD_NUM_FPREGS	33

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

static void
mipsnbsd_supply_fpregset (const struct regset *regset,
			  struct regcache *regcache,
			  int regnum, const void *fpregs, size_t len)
{
  size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
  const char *regs = fpregs;
  int i;

  gdb_assert (len >= MIPSNBSD_NUM_FPREGS * regsize);

  for (i = MIPS_FP0_REGNUM; i <= MIPS_FSR_REGNUM; i++)
    {
      if (regnum == i || regnum == -1)
	regcache_raw_supply (regcache, i,
			     regs + (i - MIPS_FP0_REGNUM) * regsize);
    }
}

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

static void
mipsnbsd_supply_gregset (const struct regset *regset,
			 struct regcache *regcache, int regnum,
			 const void *gregs, size_t len)
{
  size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
  const char *regs = gregs;
  int i;

  gdb_assert (len >= MIPSNBSD_NUM_GREGS * regsize);

  for (i = 0; i <= MIPS_PC_REGNUM; i++)
    {
      if (regnum == i || regnum == -1)
	regcache_raw_supply (regcache, i, regs + i * regsize);
    }

  if (len >= (MIPSNBSD_NUM_GREGS + MIPSNBSD_NUM_FPREGS) * regsize)
    {
      regs += MIPSNBSD_NUM_GREGS * regsize;
      len -= MIPSNBSD_NUM_GREGS * regsize;
      mipsnbsd_supply_fpregset (regset, regcache, regnum, regs, len);
    }
}

/* NetBSD/mips register sets.  */

static struct regset mipsnbsd_gregset =
{
  NULL,
  mipsnbsd_supply_gregset
};

static struct regset mipsnbsd_fpregset =
{
  NULL,
  mipsnbsd_supply_fpregset
};

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

static const struct regset *
mipsnbsd_regset_from_core_section (struct gdbarch *gdbarch,
				   const char *sect_name, size_t sect_size)
{
  size_t regsize = mips_isa_regsize (gdbarch);
  
  if (strcmp (sect_name, ".reg") == 0
      && sect_size >= MIPSNBSD_NUM_GREGS * regsize)
    return &mipsnbsd_gregset;

  if (strcmp (sect_name, ".reg2") == 0
      && sect_size >= MIPSNBSD_NUM_FPREGS * regsize)
    return &mipsnbsd_fpregset;

  return NULL;
}
\f

/* Conveniently, GDB uses the same register numbering as the
   ptrace register structure used by NetBSD/mips.  */

void
mipsnbsd_supply_reg (struct regcache *regcache, const char *regs, int regno)
{
  int i;

  for (i = 0; i <= PC_REGNUM; i++)
    {
      if (regno == i || regno == -1)
	{
	  if (gdbarch_cannot_fetch_register (current_gdbarch, i))
	    regcache_raw_supply (regcache, i, NULL);
	  else
            regcache_raw_supply (regcache, i,
				 regs + (i * mips_isa_regsize (current_gdbarch)));
        }
    }
}

void
mipsnbsd_fill_reg (const struct regcache *regcache, char *regs, int regno)
{
  int i;

  for (i = 0; i <= PC_REGNUM; i++)
    if ((regno == i || regno == -1)
	&& ! gdbarch_cannot_store_register (current_gdbarch, i))
      regcache_raw_collect (regcache, i,
			    regs + (i * mips_isa_regsize (current_gdbarch)));
}

void
mipsnbsd_supply_fpreg (struct regcache *regcache, const char *fpregs, int regno)
{
  int i;

  for (i = FP0_REGNUM;
       i <= mips_regnum (current_gdbarch)->fp_implementation_revision;
       i++)
    {
      if (regno == i || regno == -1)
	{
	  if (gdbarch_cannot_fetch_register (current_gdbarch, i))
	    regcache_raw_supply (regcache, i, NULL);
	  else
            regcache_raw_supply (regcache, i,
				 fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
	}
    }
}

void
mipsnbsd_fill_fpreg (const struct regcache *regcache, char *fpregs, int regno)
{
  int i;

  for (i = FP0_REGNUM; i <= mips_regnum (current_gdbarch)->fp_control_status;
       i++)
    if ((regno == i || regno == -1) 
	&& ! gdbarch_cannot_store_register (current_gdbarch, i))
      regcache_raw_collect (regcache, i,
			    fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
}

/* Under NetBSD/mips, signal handler invocations can be identified by the
   designated code sequence that is used to return from a signal handler.
   In particular, the return address of a signal handler points to the
   following code sequence:

	addu	a0, sp, 16
	li	v0, 295			# __sigreturn14
	syscall
   
   Each instruction has a unique encoding, so we simply attempt to match
   the instruction the PC is pointing to with any of the above instructions.
   If there is a hit, we know the offset to the start of the designated
   sequence and can then check whether we really are executing in the
   signal trampoline.  If not, -1 is returned, otherwise the offset from the
   start of the return sequence is returned.  */

#define RETCODE_NWORDS	3
#define RETCODE_SIZE	(RETCODE_NWORDS * 4)

static const unsigned char sigtramp_retcode_mipsel[RETCODE_SIZE] =
{
  0x10, 0x00, 0xa4, 0x27,	/* addu a0, sp, 16 */
  0x27, 0x01, 0x02, 0x24,	/* li v0, 295 */
  0x0c, 0x00, 0x00, 0x00,	/* syscall */
};

static const unsigned char sigtramp_retcode_mipseb[RETCODE_SIZE] =
{
  0x27, 0xa4, 0x00, 0x10,	/* addu a0, sp, 16 */
  0x24, 0x02, 0x01, 0x27,	/* li v0, 295 */
  0x00, 0x00, 0x00, 0x0c,	/* syscall */
};

static LONGEST
mipsnbsd_sigtramp_offset (struct frame_info *next_frame)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  const char *retcode = TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
  	? sigtramp_retcode_mipseb : sigtramp_retcode_mipsel;
  unsigned char ret[RETCODE_SIZE], w[4];
  LONGEST off;
  int i;

  if (!safe_frame_unwind_memory (next_frame, pc, w, sizeof (w)))
    return -1;

  for (i = 0; i < RETCODE_NWORDS; i++)
    {
      if (memcmp (w, retcode + (i * 4), 4) == 0)
	break;
    }
  if (i == RETCODE_NWORDS)
    return -1;

  off = i * 4;
  pc -= off;

  if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret)))
    return -1;

  if (memcmp (ret, retcode, RETCODE_SIZE) == 0)
    return off;

  return -1;
}

/* Figure out where the longjmp will land.  We expect that we have
   just entered longjmp and haven't yet setup the stack frame, so the
   args are still in the argument regs.  MIPS_A0_REGNUM points at the
   jmp_buf structure from which we extract the PC that we will land
   at.  The PC is copied into *pc.  This routine returns true on
   success.  */

#define NBSD_MIPS_JB_PC			(2 * 4)
#define NBSD_MIPS_JB_ELEMENT_SIZE	mips_isa_regsize (current_gdbarch)
#define NBSD_MIPS_JB_OFFSET		(NBSD_MIPS_JB_PC * \
					 NBSD_MIPS_JB_ELEMENT_SIZE)

static int
mipsnbsd_get_longjmp_target (CORE_ADDR *pc)
{
  CORE_ADDR jb_addr;
  char *buf;

  buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);

  jb_addr = read_register (MIPS_A0_REGNUM);

  if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET, buf,
  			  NBSD_MIPS_JB_ELEMENT_SIZE))
    return 0;

  *pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE);

  return 1;
}

static int
mipsnbsd_cannot_fetch_register (int regno)
{
  return (regno == MIPS_ZERO_REGNUM
	  || regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
}

static int
mipsnbsd_cannot_store_register (int regno)
{
  return (regno == MIPS_ZERO_REGNUM
	  || regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
}

/* Shared library support.  */

/* NetBSD/mips uses a slightly different `struct link_map' than the
   other NetBSD platforms.  */

static struct link_map_offsets *
mipsnbsd_ilp32_fetch_link_map_offsets (void)
{
  static struct link_map_offsets lmo;
  static struct link_map_offsets *lmp = NULL;

  if (lmp == NULL) 
    {
      lmp = &lmo;

      lmo.r_version_offset = 0;
      lmo.r_version_size = 4;
      lmo.r_map_offset = 4;
      lmo.r_ldsomap_offset = -1;

      /* Everything we need is in the first 24 bytes.  */
      lmo.link_map_size = 24;
      lmo.l_addr_offset = 4;
      lmo.l_name_offset = 8;
      lmo.l_ld_offset = 12;
      lmo.l_next_offset = 16;
      lmo.l_prev_offset = 20;
    }

  return lmp;
}

static struct link_map_offsets *
mipsnbsd_lp64_fetch_link_map_offsets (void)
{
  static struct link_map_offsets lmo;
  static struct link_map_offsets *lmp = NULL;

  if (lmp == NULL)
    {
      lmp = &lmo;

      lmo.r_version_offset = 0;
      lmo.r_version_size = 4;
      lmo.r_map_offset = 8;
      lmo.r_ldsomap_offset = -1;

      /* Everything we need is in the first 40 bytes.  */
      lmo.link_map_size = 48;
      lmo.l_addr_offset = 0;
      lmo.l_name_offset = 16; 
      lmo.l_ld_offset = 24;
      lmo.l_next_offset = 32;
      lmo.l_prev_offset = 40;
    }

  return lmp;
}
\f

static void
mipsnbsd_init_abi (struct gdbarch_info info,
                   struct gdbarch *gdbarch)
{
  set_gdbarch_regset_from_core_section
    (gdbarch, mipsnbsd_regset_from_core_section);

  set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);

  set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
  set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);

  set_gdbarch_software_single_step (gdbarch, mips_software_single_step);

  /* NetBSD/mips has SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
	       mipsnbsd_ilp32_fetch_link_map_offsets :
	       mipsnbsd_lp64_fetch_link_map_offsets));
}
\f

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

  return GDB_OSABI_UNKNOWN;
}

void
_initialize_mipsnbsd_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,
			  mipsnbsd_init_abi);
}
Commit	Line	Data
d1180b0f MK	1	/* Target-dependent code for NetBSD/mips.
d1180b0f MK	2
6aba47ca	3	Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
e4cd0d6a	4
45888261 JT	5	Contributed by Wasabi Systems, Inc.
	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
197e01b6 EZ	21	Foundation, Inc., 51 Franklin Street, Fifth Floor,
197e01b6 EZ	22	Boston, MA 02110-1301, USA. */
45888261 JT	23
	24	#include "defs.h"
	25	#include "gdbcore.h"
	26	#include "regcache.h"
d1180b0f	27	#include "regset.h"
45888261 JT	28	#include "target.h"
	29	#include "value.h"
	30	#include "osabi.h"
	31
d1180b0f	32	#include "gdb_assert.h"
4c7d22cb MK	33	#include "gdb_string.h"
4c7d22cb MK	34
3d9b49b0	35	#include "nbsd-tdep.h"
45888261	36	#include "mipsnbsd-tdep.h"
1777c7b4	37	#include "mips-tdep.h"
45888261 JT	38
	39	#include "solib-svr4.h"
	40
d1180b0f MK	41	/* Shorthand for some register numbers used below. */
	42	#define MIPS_PC_REGNUM MIPS_EMBED_PC_REGNUM
	43	#define MIPS_FP0_REGNUM MIPS_EMBED_FP0_REGNUM
	44	#define MIPS_FSR_REGNUM MIPS_EMBED_FP0_REGNUM + 32
	45
	46	/* Core file support. */
	47
	48	/* Number of registers in `struct reg' from <machine/reg.h>. */
	49	#define MIPSNBSD_NUM_GREGS 38
	50
	51	/* Number of registers in `struct fpreg' from <machine/reg.h>. */
	52	#define MIPSNBSD_NUM_FPREGS 33
	53
	54	/* Supply register REGNUM from the buffer specified by FPREGS and LEN
	55	in the floating-point register set REGSET to register cache
	56	REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
	57
	58	static void
	59	mipsnbsd_supply_fpregset (const struct regset *regset,
	60	struct regcache *regcache,
	61	int regnum, const void *fpregs, size_t len)
	62	{
	63	size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
	64	const char *regs = fpregs;
	65	int i;
	66
	67	gdb_assert (len >= MIPSNBSD_NUM_FPREGS * regsize);
	68
	69	for (i = MIPS_FP0_REGNUM; i <= MIPS_FSR_REGNUM; i++)
	70	{
	71	if (regnum == i \|\| regnum == -1)
	72	regcache_raw_supply (regcache, i,
	73	regs + (i - MIPS_FP0_REGNUM) * regsize);
	74	}
	75	}
	76
	77	/* Supply register REGNUM from the buffer specified by GREGS and LEN
	78	in the general-purpose register set REGSET to register cache
	79	REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
	80
	81	static void
	82	mipsnbsd_supply_gregset (const struct regset *regset,
	83	struct regcache *regcache, int regnum,
	84	const void *gregs, size_t len)
	85	{
	86	size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
	87	const char *regs = gregs;
	88	int i;
	89
	90	gdb_assert (len >= MIPSNBSD_NUM_GREGS * regsize);
	91
	92	for (i = 0; i <= MIPS_PC_REGNUM; i++)
	93	{
	94	if (regnum == i \|\| regnum == -1)
	95	regcache_raw_supply (regcache, i, regs + i * regsize);
	96	}
	97
	98	if (len >= (MIPSNBSD_NUM_GREGS + MIPSNBSD_NUM_FPREGS) * regsize)
	99	{
	100	regs += MIPSNBSD_NUM_GREGS * regsize;
	101	len -= MIPSNBSD_NUM_GREGS * regsize;
	102	mipsnbsd_supply_fpregset (regset, regcache, regnum, regs, len);
	103	}
	104	}
105
106	/* NetBSD/mips register sets. */
107
108	static struct regset mipsnbsd_gregset =
109	{
110	NULL,
111	mipsnbsd_supply_gregset
112	};
113
114	static struct regset mipsnbsd_fpregset =
115	{
116	NULL,
117	mipsnbsd_supply_fpregset
118	};
119
120	/* Return the appropriate register set for the core section identified
121	by SECT_NAME and SECT_SIZE. */
122
123	static const struct regset *
124	mipsnbsd_regset_from_core_section (struct gdbarch *gdbarch,
125	const char *sect_name, size_t sect_size)
126	{
127	size_t regsize = mips_isa_regsize (gdbarch);
128
129	if (strcmp (sect_name, ".reg") == 0
130	&& sect_size >= MIPSNBSD_NUM_GREGS * regsize)
131	return &mipsnbsd_gregset;
132
133	if (strcmp (sect_name, ".reg2") == 0
134	&& sect_size >= MIPSNBSD_NUM_FPREGS * regsize)
135	return &mipsnbsd_fpregset;
136
137	return NULL;
138	}
139	\f
140
45888261 JT	141	/* Conveniently, GDB uses the same register numbering as the
	142	ptrace register structure used by NetBSD/mips. */
	143
	144	void
28f5035f	145	mipsnbsd_supply_reg (struct regcache regcache, const char regs, int regno)
45888261 JT	146	{
	147	int i;
	148
	149	for (i = 0; i <= PC_REGNUM; i++)
	150	{
	151	if (regno == i \|\| regno == -1)
	152	{
8d4c1ba3	153	if (gdbarch_cannot_fetch_register (current_gdbarch, i))
28f5035f	154	regcache_raw_supply (regcache, i, NULL);
45888261	155	else
28f5035f	156	regcache_raw_supply (regcache, i,
23a6d369	157	regs + (i * mips_isa_regsize (current_gdbarch)));
45888261 JT	158	}
	159	}
	160	}
	161
	162	void
28f5035f	163	mipsnbsd_fill_reg (const struct regcache regcache, char regs, int regno)
45888261 JT	164	{
	165	int i;
	166
	167	for (i = 0; i <= PC_REGNUM; i++)
8d4c1ba3 UW	168	if ((regno == i \|\| regno == -1)
8d4c1ba3 UW	169	&& ! gdbarch_cannot_store_register (current_gdbarch, i))
28f5035f	170	regcache_raw_collect (regcache, i,
822c9732	171	regs + (i * mips_isa_regsize (current_gdbarch)));
45888261 JT	172	}
	173
	174	void
28f5035f	175	mipsnbsd_supply_fpreg (struct regcache regcache, const char fpregs, int regno)
45888261 JT	176	{
	177	int i;
	178
56cea623 AC	179	for (i = FP0_REGNUM;
	180	i <= mips_regnum (current_gdbarch)->fp_implementation_revision;
	181	i++)
45888261 JT	182	{
	183	if (regno == i \|\| regno == -1)
	184	{
8d4c1ba3	185	if (gdbarch_cannot_fetch_register (current_gdbarch, i))
28f5035f	186	regcache_raw_supply (regcache, i, NULL);
45888261	187	else
28f5035f	188	regcache_raw_supply (regcache, i,
23a6d369	189	fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
45888261 JT	190	}
	191	}
	192	}
	193
	194	void
28f5035f	195	mipsnbsd_fill_fpreg (const struct regcache regcache, char fpregs, int regno)
45888261 JT	196	{
	197	int i;
	198
56cea623 AC	199	for (i = FP0_REGNUM; i <= mips_regnum (current_gdbarch)->fp_control_status;
56cea623 AC	200	i++)
8d4c1ba3 UW	201	if ((regno == i \|\| regno == -1)
8d4c1ba3 UW	202	&& ! gdbarch_cannot_store_register (current_gdbarch, i))
28f5035f	203	regcache_raw_collect (regcache, i,
822c9732	204	fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
45888261 JT	205	}
45888261 JT	206
45888261 JT	207	/* Under NetBSD/mips, signal handler invocations can be identified by the
	208	designated code sequence that is used to return from a signal handler.
	209	In particular, the return address of a signal handler points to the
	210	following code sequence:
	211
	212	addu a0, sp, 16
	213	li v0, 295 # __sigreturn14
	214	syscall
	215
	216	Each instruction has a unique encoding, so we simply attempt to match
	217	the instruction the PC is pointing to with any of the above instructions.
	218	If there is a hit, we know the offset to the start of the designated
	219	sequence and can then check whether we really are executing in the
	220	signal trampoline. If not, -1 is returned, otherwise the offset from the
	221	start of the return sequence is returned. */
	222
	223	#define RETCODE_NWORDS 3
	224	#define RETCODE_SIZE (RETCODE_NWORDS * 4)
	225
	226	static const unsigned char sigtramp_retcode_mipsel[RETCODE_SIZE] =
	227	{
	228	0x10, 0x00, 0xa4, 0x27, /* addu a0, sp, 16 */
	229	0x27, 0x01, 0x02, 0x24, /* li v0, 295 */
	230	0x0c, 0x00, 0x00, 0x00, /* syscall */
	231	};
	232
	233	static const unsigned char sigtramp_retcode_mipseb[RETCODE_SIZE] =
	234	{
	235	0x27, 0xa4, 0x00, 0x10, /* addu a0, sp, 16 */
	236	0x24, 0x02, 0x01, 0x27, /* li v0, 295 */
	237	0x00, 0x00, 0x00, 0x0c, /* syscall */
	238	};
	239
	240	static LONGEST
4c7d22cb	241	mipsnbsd_sigtramp_offset (struct frame_info *next_frame)
45888261	242	{
4c7d22cb	243	CORE_ADDR pc = frame_pc_unwind (next_frame);
45888261 JT	244	const char *retcode = TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
	245	? sigtramp_retcode_mipseb : sigtramp_retcode_mipsel;
	246	unsigned char ret[RETCODE_SIZE], w[4];
	247	LONGEST off;
	248	int i;
	249
4c7d22cb	250	if (!safe_frame_unwind_memory (next_frame, pc, w, sizeof (w)))
45888261 JT	251	return -1;
	252
	253	for (i = 0; i < RETCODE_NWORDS; i++)
	254	{
	255	if (memcmp (w, retcode + (i * 4), 4) == 0)
	256	break;
	257	}
	258	if (i == RETCODE_NWORDS)
	259	return -1;
	260
	261	off = i * 4;
	262	pc -= off;
	263
4c7d22cb	264	if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret)))
45888261 JT	265	return -1;
	266
	267	if (memcmp (ret, retcode, RETCODE_SIZE) == 0)
	268	return off;
	269
	270	return -1;
	271	}
	272
45888261	273	/* Figure out where the longjmp will land. We expect that we have
4c7d22cb MK	274	just entered longjmp and haven't yet setup the stack frame, so the
4c7d22cb MK	275	args are still in the argument regs. MIPS_A0_REGNUM points at the
45888261 JT	276	jmp_buf structure from which we extract the PC that we will land
	277	at. The PC is copied into *pc. This routine returns true on
	278	success. */
	279
	280	#define NBSD_MIPS_JB_PC (2 * 4)
1b13c4f6	281	#define NBSD_MIPS_JB_ELEMENT_SIZE mips_isa_regsize (current_gdbarch)
45888261 JT	282	#define NBSD_MIPS_JB_OFFSET (NBSD_MIPS_JB_PC * \
	283	NBSD_MIPS_JB_ELEMENT_SIZE)
	284
	285	static int
	286	mipsnbsd_get_longjmp_target (CORE_ADDR *pc)
	287	{
	288	CORE_ADDR jb_addr;
	289	char *buf;
	290
	291	buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);
	292
4c7d22cb	293	jb_addr = read_register (MIPS_A0_REGNUM);
45888261 JT	294
	295	if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET, buf,
	296	NBSD_MIPS_JB_ELEMENT_SIZE))
	297	return 0;
	298
7c0b4a20	299	*pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE);
45888261 JT	300
	301	return 1;
	302	}
	303
	304	static int
	305	mipsnbsd_cannot_fetch_register (int regno)
	306	{
4c7d22cb	307	return (regno == MIPS_ZERO_REGNUM
56cea623	308	\|\| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
45888261 JT	309	}
	310
	311	static int
	312	mipsnbsd_cannot_store_register (int regno)
	313	{
4c7d22cb	314	return (regno == MIPS_ZERO_REGNUM
56cea623	315	\|\| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
45888261 JT	316	}
45888261 JT	317
fabe86c8 MK	318	/* Shared library support. */
	319
	320	/* NetBSD/mips uses a slightly different `struct link_map' than the
45888261	321	other NetBSD platforms. */
fabe86c8	322
45888261	323	static struct link_map_offsets *
fabe86c8	324	mipsnbsd_ilp32_fetch_link_map_offsets (void)
45888261 JT	325	{
	326	static struct link_map_offsets lmo;
	327	static struct link_map_offsets *lmp = NULL;
	328
	329	if (lmp == NULL)
	330	{
	331	lmp = &lmo;
	332
e4cd0d6a MK	333	lmo.r_version_offset = 0;
e4cd0d6a MK	334	lmo.r_version_size = 4;
45888261	335	lmo.r_map_offset = 4;
e4cd0d6a	336	lmo.r_ldsomap_offset = -1;
45888261	337
fabe86c8	338	/* Everything we need is in the first 24 bytes. */
45888261	339	lmo.link_map_size = 24;
4c7d22cb	340	lmo.l_addr_offset = 4;
45888261	341	lmo.l_name_offset = 8;
cc10cae3	342	lmo.l_ld_offset = 12;
45888261	343	lmo.l_next_offset = 16;
45888261	344	lmo.l_prev_offset = 20;
45888261 JT	345	}
	346
	347	return lmp;
	348	}
	349
	350	static struct link_map_offsets *
fabe86c8	351	mipsnbsd_lp64_fetch_link_map_offsets (void)
45888261 JT	352	{
	353	static struct link_map_offsets lmo;
	354	static struct link_map_offsets *lmp = NULL;
	355
	356	if (lmp == NULL)
	357	{
	358	lmp = &lmo;
	359
e4cd0d6a MK	360	lmo.r_version_offset = 0;
	361	lmo.r_version_size = 4;
	362	lmo.r_map_offset = 8;
	363	lmo.r_ldsomap_offset = -1;
45888261	364
fabe86c8	365	/* Everything we need is in the first 40 bytes. */
45888261	366	lmo.link_map_size = 48;
45888261	367	lmo.l_addr_offset = 0;
45888261	368	lmo.l_name_offset = 16;
cc10cae3	369	lmo.l_ld_offset = 24;
45888261	370	lmo.l_next_offset = 32;
45888261	371	lmo.l_prev_offset = 40;
45888261 JT	372	}
	373
	374	return lmp;
	375	}
fabe86c8	376	\f
45888261 JT	377
	378	static void
	379	mipsnbsd_init_abi (struct gdbarch_info info,
	380	struct gdbarch *gdbarch)
	381	{
d1180b0f MK	382	set_gdbarch_regset_from_core_section
	383	(gdbarch, mipsnbsd_regset_from_core_section);
	384
45888261 JT	385	set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);
	386
	387	set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
	388	set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);
	389
	390	set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
	391
fabe86c8 MK	392	/* NetBSD/mips has SVR4-style shared libraries. */
	393	set_solib_svr4_fetch_link_map_offsets
	394	(gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
	395	mipsnbsd_ilp32_fetch_link_map_offsets :
	396	mipsnbsd_lp64_fetch_link_map_offsets));
45888261	397	}
d1180b0f MK	398	\f
	399
	400	static enum gdb_osabi
	401	mipsnbsd_core_osabi_sniffer (bfd *abfd)
	402	{
	403	if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
	404	return GDB_OSABI_NETBSD_ELF;
	405
	406	return GDB_OSABI_UNKNOWN;
	407	}
45888261 JT	408
	409	void
	410	_initialize_mipsnbsd_tdep (void)
	411	{
05816f70	412	gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,
45888261	413	mipsnbsd_init_abi);
45888261	414	}