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

/* Target-dependent code for NetBSD/mips.

   Copyright 2002, 2003, 2004 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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, 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 (char *regs, int regno)
{
  int i;

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

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

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

void
mipsnbsd_supply_fpreg (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 (CANNOT_FETCH_REGISTER (i))
	    regcache_raw_supply (current_regcache, i, NULL);
	  else
            regcache_raw_supply (current_regcache, i,
				 fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
	}
    }
}

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

  for (i = FP0_REGNUM; i <= mips_regnum (current_gdbarch)->fp_control_status;
       i++)
    if ((regno == i || regno == -1) && ! CANNOT_STORE_REGISTER (i))
      regcache_raw_collect (current_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;

      /* Everything we need is in the first 8 bytes.  */
      lmo.r_debug_size = 8;
      lmo.r_map_offset = 4;
      lmo.r_map_size   = 4;

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

  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;

      /* Everything we need is in the first 16 bytes.  */
      lmo.r_debug_size = 16;
      lmo.r_map_offset = 8;  
      lmo.r_map_size   = 8;

      /* Everything we need is in the first 40 bytes.  */
      lmo.link_map_size = 48;
      lmo.l_addr_offset = 0;
      lmo.l_addr_size   = 8;
      lmo.l_name_offset = 16; 
      lmo.l_name_size   = 8;
      lmo.l_next_offset = 32;
      lmo.l_next_size   = 8;
      lmo.l_prev_offset = 40;
      lmo.l_prev_size   = 8;
    }

  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
1777c7b4	3	Copyright 2002, 2003, 2004 Free Software Foundation, Inc.
45888261 JT	4	Contributed by Wasabi Systems, Inc.
	5
	6	This file is part of GDB.
	7
	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 2 of the License, or
	11	(at your option) any later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program; if not, write to the Free Software
	20	Foundation, Inc., 59 Temple Place - Suite 330,
	21	Boston, MA 02111-1307, USA. */
	22
	23	#include "defs.h"
	24	#include "gdbcore.h"
	25	#include "regcache.h"
d1180b0f	26	#include "regset.h"
45888261 JT	27	#include "target.h"
	28	#include "value.h"
	29	#include "osabi.h"
	30
d1180b0f	31	#include "gdb_assert.h"
4c7d22cb MK	32	#include "gdb_string.h"
4c7d22cb MK	33
3d9b49b0	34	#include "nbsd-tdep.h"
45888261	35	#include "mipsnbsd-tdep.h"
1777c7b4	36	#include "mips-tdep.h"
45888261 JT	37
	38	#include "solib-svr4.h"
	39
d1180b0f MK	40	/* Shorthand for some register numbers used below. */
	41	#define MIPS_PC_REGNUM MIPS_EMBED_PC_REGNUM
	42	#define MIPS_FP0_REGNUM MIPS_EMBED_FP0_REGNUM
	43	#define MIPS_FSR_REGNUM MIPS_EMBED_FP0_REGNUM + 32
	44
	45	/* Core file support. */
	46
	47	/* Number of registers in `struct reg' from <machine/reg.h>. */
	48	#define MIPSNBSD_NUM_GREGS 38
	49
	50	/* Number of registers in `struct fpreg' from <machine/reg.h>. */
	51	#define MIPSNBSD_NUM_FPREGS 33
	52
	53	/* Supply register REGNUM from the buffer specified by FPREGS and LEN
	54	in the floating-point register set REGSET to register cache
	55	REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
	56
	57	static void
	58	mipsnbsd_supply_fpregset (const struct regset *regset,
	59	struct regcache *regcache,
	60	int regnum, const void *fpregs, size_t len)
	61	{
	62	size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
	63	const char *regs = fpregs;
	64	int i;
	65
	66	gdb_assert (len >= MIPSNBSD_NUM_FPREGS * regsize);
	67
	68	for (i = MIPS_FP0_REGNUM; i <= MIPS_FSR_REGNUM; i++)
	69	{
	70	if (regnum == i \|\| regnum == -1)
	71	regcache_raw_supply (regcache, i,
	72	regs + (i - MIPS_FP0_REGNUM) * regsize);
	73	}
	74	}
	75
	76	/* Supply register REGNUM from the buffer specified by GREGS and LEN
	77	in the general-purpose register set REGSET to register cache
	78	REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
	79
	80	static void
	81	mipsnbsd_supply_gregset (const struct regset *regset,
	82	struct regcache *regcache, int regnum,
	83	const void *gregs, size_t len)
	84	{
	85	size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
	86	const char *regs = gregs;
	87	int i;
	88
	89	gdb_assert (len >= MIPSNBSD_NUM_GREGS * regsize);
	90
	91	for (i = 0; i <= MIPS_PC_REGNUM; i++)
	92	{
	93	if (regnum == i \|\| regnum == -1)
	94	regcache_raw_supply (regcache, i, regs + i * regsize);
	95	}
	96
	97	if (len >= (MIPSNBSD_NUM_GREGS + MIPSNBSD_NUM_FPREGS) * regsize)
	98	{
	99	regs += MIPSNBSD_NUM_GREGS * regsize;
	100	len -= MIPSNBSD_NUM_GREGS * regsize;
	101	mipsnbsd_supply_fpregset (regset, regcache, regnum, regs, len);
	102	}
	103	}
104
105	/* NetBSD/mips register sets. */
106
107	static struct regset mipsnbsd_gregset =
108	{
109	NULL,
110	mipsnbsd_supply_gregset
111	};
112
113	static struct regset mipsnbsd_fpregset =
114	{
115	NULL,
116	mipsnbsd_supply_fpregset
117	};
118
119	/* Return the appropriate register set for the core section identified
120	by SECT_NAME and SECT_SIZE. */
121
122	static const struct regset *
123	mipsnbsd_regset_from_core_section (struct gdbarch *gdbarch,
124	const char *sect_name, size_t sect_size)
125	{
126	size_t regsize = mips_isa_regsize (gdbarch);
127
128	if (strcmp (sect_name, ".reg") == 0
129	&& sect_size >= MIPSNBSD_NUM_GREGS * regsize)
130	return &mipsnbsd_gregset;
131
132	if (strcmp (sect_name, ".reg2") == 0
133	&& sect_size >= MIPSNBSD_NUM_FPREGS * regsize)
134	return &mipsnbsd_fpregset;
135
136	return NULL;
137	}
138	\f
139
45888261 JT	140	/* Conveniently, GDB uses the same register numbering as the
	141	ptrace register structure used by NetBSD/mips. */
	142
	143	void
	144	mipsnbsd_supply_reg (char *regs, int regno)
	145	{
	146	int i;
	147
	148	for (i = 0; i <= PC_REGNUM; i++)
	149	{
	150	if (regno == i \|\| regno == -1)
	151	{
	152	if (CANNOT_FETCH_REGISTER (i))
23a6d369	153	regcache_raw_supply (current_regcache, i, NULL);
45888261	154	else
23a6d369 AC	155	regcache_raw_supply (current_regcache, i,
23a6d369 AC	156	regs + (i * mips_isa_regsize (current_gdbarch)));
45888261 JT	157	}
	158	}
	159	}
	160
	161	void
	162	mipsnbsd_fill_reg (char *regs, int regno)
	163	{
	164	int i;
	165
	166	for (i = 0; i <= PC_REGNUM; i++)
	167	if ((regno == i \|\| regno == -1) && ! CANNOT_STORE_REGISTER (i))
822c9732 AC	168	regcache_raw_collect (current_regcache, i,
822c9732 AC	169	regs + (i * mips_isa_regsize (current_gdbarch)));
45888261 JT	170	}
	171
	172	void
	173	mipsnbsd_supply_fpreg (char *fpregs, int regno)
	174	{
	175	int i;
	176
56cea623 AC	177	for (i = FP0_REGNUM;
	178	i <= mips_regnum (current_gdbarch)->fp_implementation_revision;
	179	i++)
45888261 JT	180	{
	181	if (regno == i \|\| regno == -1)
	182	{
	183	if (CANNOT_FETCH_REGISTER (i))
23a6d369	184	regcache_raw_supply (current_regcache, i, NULL);
45888261	185	else
23a6d369 AC	186	regcache_raw_supply (current_regcache, i,
23a6d369 AC	187	fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
45888261 JT	188	}
	189	}
	190	}
	191
	192	void
	193	mipsnbsd_fill_fpreg (char *fpregs, int regno)
	194	{
	195	int i;
	196
56cea623 AC	197	for (i = FP0_REGNUM; i <= mips_regnum (current_gdbarch)->fp_control_status;
56cea623 AC	198	i++)
45888261	199	if ((regno == i \|\| regno == -1) && ! CANNOT_STORE_REGISTER (i))
822c9732 AC	200	regcache_raw_collect (current_regcache, i,
822c9732 AC	201	fpregs + ((i - FP0_REGNUM) * mips_isa_regsize (current_gdbarch)));
45888261 JT	202	}
45888261 JT	203
45888261 JT	204	/* Under NetBSD/mips, signal handler invocations can be identified by the
	205	designated code sequence that is used to return from a signal handler.
	206	In particular, the return address of a signal handler points to the
	207	following code sequence:
	208
	209	addu a0, sp, 16
	210	li v0, 295 # __sigreturn14
	211	syscall
	212
	213	Each instruction has a unique encoding, so we simply attempt to match
	214	the instruction the PC is pointing to with any of the above instructions.
	215	If there is a hit, we know the offset to the start of the designated
	216	sequence and can then check whether we really are executing in the
	217	signal trampoline. If not, -1 is returned, otherwise the offset from the
	218	start of the return sequence is returned. */
	219
	220	#define RETCODE_NWORDS 3
	221	#define RETCODE_SIZE (RETCODE_NWORDS * 4)
	222
	223	static const unsigned char sigtramp_retcode_mipsel[RETCODE_SIZE] =
	224	{
	225	0x10, 0x00, 0xa4, 0x27, /* addu a0, sp, 16 */
	226	0x27, 0x01, 0x02, 0x24, /* li v0, 295 */
	227	0x0c, 0x00, 0x00, 0x00, /* syscall */
	228	};
	229
	230	static const unsigned char sigtramp_retcode_mipseb[RETCODE_SIZE] =
	231	{
	232	0x27, 0xa4, 0x00, 0x10, /* addu a0, sp, 16 */
	233	0x24, 0x02, 0x01, 0x27, /* li v0, 295 */
	234	0x00, 0x00, 0x00, 0x0c, /* syscall */
	235	};
	236
	237	static LONGEST
4c7d22cb	238	mipsnbsd_sigtramp_offset (struct frame_info *next_frame)
45888261	239	{
4c7d22cb	240	CORE_ADDR pc = frame_pc_unwind (next_frame);
45888261 JT	241	const char *retcode = TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
	242	? sigtramp_retcode_mipseb : sigtramp_retcode_mipsel;
	243	unsigned char ret[RETCODE_SIZE], w[4];
	244	LONGEST off;
	245	int i;
	246
4c7d22cb	247	if (!safe_frame_unwind_memory (next_frame, pc, w, sizeof (w)))
45888261 JT	248	return -1;
	249
	250	for (i = 0; i < RETCODE_NWORDS; i++)
	251	{
	252	if (memcmp (w, retcode + (i * 4), 4) == 0)
	253	break;
	254	}
	255	if (i == RETCODE_NWORDS)
	256	return -1;
	257
	258	off = i * 4;
	259	pc -= off;
	260
4c7d22cb	261	if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret)))
45888261 JT	262	return -1;
	263
	264	if (memcmp (ret, retcode, RETCODE_SIZE) == 0)
	265	return off;
	266
	267	return -1;
	268	}
	269
45888261	270	/* Figure out where the longjmp will land. We expect that we have
4c7d22cb MK	271	just entered longjmp and haven't yet setup the stack frame, so the
4c7d22cb MK	272	args are still in the argument regs. MIPS_A0_REGNUM points at the
45888261 JT	273	jmp_buf structure from which we extract the PC that we will land
	274	at. The PC is copied into *pc. This routine returns true on
	275	success. */
	276
	277	#define NBSD_MIPS_JB_PC (2 * 4)
1b13c4f6	278	#define NBSD_MIPS_JB_ELEMENT_SIZE mips_isa_regsize (current_gdbarch)
45888261 JT	279	#define NBSD_MIPS_JB_OFFSET (NBSD_MIPS_JB_PC * \
	280	NBSD_MIPS_JB_ELEMENT_SIZE)
	281
	282	static int
	283	mipsnbsd_get_longjmp_target (CORE_ADDR *pc)
	284	{
	285	CORE_ADDR jb_addr;
	286	char *buf;
	287
	288	buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);
	289
4c7d22cb	290	jb_addr = read_register (MIPS_A0_REGNUM);
45888261 JT	291
	292	if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET, buf,
	293	NBSD_MIPS_JB_ELEMENT_SIZE))
	294	return 0;
	295
7c0b4a20	296	*pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE);
45888261 JT	297
	298	return 1;
	299	}
	300
	301	static int
	302	mipsnbsd_cannot_fetch_register (int regno)
	303	{
4c7d22cb	304	return (regno == MIPS_ZERO_REGNUM
56cea623	305	\|\| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
45888261 JT	306	}
	307
	308	static int
	309	mipsnbsd_cannot_store_register (int regno)
	310	{
4c7d22cb	311	return (regno == MIPS_ZERO_REGNUM
56cea623	312	\|\| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
45888261 JT	313	}
45888261 JT	314
fabe86c8 MK	315	/* Shared library support. */
	316
	317	/* NetBSD/mips uses a slightly different `struct link_map' than the
45888261	318	other NetBSD platforms. */
fabe86c8	319
45888261	320	static struct link_map_offsets *
fabe86c8	321	mipsnbsd_ilp32_fetch_link_map_offsets (void)
45888261 JT	322	{
	323	static struct link_map_offsets lmo;
	324	static struct link_map_offsets *lmp = NULL;
	325
	326	if (lmp == NULL)
	327	{
	328	lmp = &lmo;
	329
fabe86c8 MK	330	/* Everything we need is in the first 8 bytes. */
fabe86c8 MK	331	lmo.r_debug_size = 8;
45888261 JT	332	lmo.r_map_offset = 4;
	333	lmo.r_map_size = 4;
	334
fabe86c8	335	/* Everything we need is in the first 24 bytes. */
45888261	336	lmo.link_map_size = 24;
4c7d22cb	337	lmo.l_addr_offset = 4;
45888261	338	lmo.l_addr_size = 4;
45888261 JT	339	lmo.l_name_offset = 8;
45888261 JT	340	lmo.l_name_size = 4;
45888261 JT	341	lmo.l_next_offset = 16;
45888261 JT	342	lmo.l_next_size = 4;
45888261 JT	343	lmo.l_prev_offset = 20;
	344	lmo.l_prev_size = 4;
	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
fabe86c8 MK	360	/* Everything we need is in the first 16 bytes. */
fabe86c8 MK	361	lmo.r_debug_size = 16;
45888261 JT	362	lmo.r_map_offset = 8;
	363	lmo.r_map_size = 8;
	364
fabe86c8	365	/* Everything we need is in the first 40 bytes. */
45888261	366	lmo.link_map_size = 48;
45888261 JT	367	lmo.l_addr_offset = 0;
45888261 JT	368	lmo.l_addr_size = 8;
45888261 JT	369	lmo.l_name_offset = 16;
45888261 JT	370	lmo.l_name_size = 8;
45888261 JT	371	lmo.l_next_offset = 32;
45888261 JT	372	lmo.l_next_size = 8;
45888261 JT	373	lmo.l_prev_offset = 40;
	374	lmo.l_prev_size = 8;
	375	}
	376
	377	return lmp;
	378	}
fabe86c8	379	\f
45888261 JT	380
	381	static void
	382	mipsnbsd_init_abi (struct gdbarch_info info,
	383	struct gdbarch *gdbarch)
	384	{
d1180b0f MK	385	set_gdbarch_regset_from_core_section
	386	(gdbarch, mipsnbsd_regset_from_core_section);
	387
45888261 JT	388	set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);
	389
	390	set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
	391	set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);
	392
	393	set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
	394
fabe86c8 MK	395	/* NetBSD/mips has SVR4-style shared libraries. */
	396	set_solib_svr4_fetch_link_map_offsets
	397	(gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
	398	mipsnbsd_ilp32_fetch_link_map_offsets :
	399	mipsnbsd_lp64_fetch_link_map_offsets));
45888261	400	}
d1180b0f MK	401	\f
	402
	403	static enum gdb_osabi
	404	mipsnbsd_core_osabi_sniffer (bfd *abfd)
	405	{
	406	if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
	407	return GDB_OSABI_NETBSD_ELF;
	408
	409	return GDB_OSABI_UNKNOWN;
	410	}
45888261 JT	411
	412	void
	413	_initialize_mipsnbsd_tdep (void)
	414	{
05816f70	415	gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,
45888261	416	mipsnbsd_init_abi);
45888261	417	}