[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 <= gdbarch_pc_regnum (current_gdbarch); 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 <= gdbarch_pc_regnum (current_gdbarch); 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 = gdbarch_fp0_regnum (current_gdbarch);
       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 - gdbarch_fp0_regnum (current_gdbarch))
				    * mips_isa_regsize (current_gdbarch)));
	}
    }
}

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

  for (i = gdbarch_fp0_regnum (current_gdbarch);
       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 - gdbarch_fp0_regnum
					     (current_gdbarch))
			      * 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 = gdbarch_byte_order (current_gdbarch)
			== 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 (struct frame_info *frame, CORE_ADDR *pc)
{
  CORE_ADDR jb_addr;
  char *buf;

  buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);

  jb_addr = get_frame_register_unsigned (frame, 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
3e8c568d	149	for (i = 0; i <= gdbarch_pc_regnum (current_gdbarch); i++)
45888261 JT	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
3e8c568d	167	for (i = 0; i <= gdbarch_pc_regnum (current_gdbarch); 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
3e8c568d	179	for (i = gdbarch_fp0_regnum (current_gdbarch);
56cea623 AC	180	i <= mips_regnum (current_gdbarch)->fp_implementation_revision;
56cea623 AC	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,
3e8c568d UW	189	fpregs
	190	+ ((i - gdbarch_fp0_regnum (current_gdbarch))
	191	* mips_isa_regsize (current_gdbarch)));
45888261 JT	192	}
	193	}
	194	}
	195
	196	void
28f5035f	197	mipsnbsd_fill_fpreg (const struct regcache regcache, char fpregs, int regno)
45888261 JT	198	{
	199	int i;
	200
3e8c568d UW	201	for (i = gdbarch_fp0_regnum (current_gdbarch);
3e8c568d UW	202	i <= mips_regnum (current_gdbarch)->fp_control_status;
56cea623	203	i++)
8d4c1ba3 UW	204	if ((regno == i \|\| regno == -1)
8d4c1ba3 UW	205	&& ! gdbarch_cannot_store_register (current_gdbarch, i))
28f5035f	206	regcache_raw_collect (regcache, i,
3e8c568d UW	207	fpregs + ((i - gdbarch_fp0_regnum
	208	(current_gdbarch))
	209	* mips_isa_regsize (current_gdbarch)));
45888261 JT	210	}
45888261 JT	211
45888261 JT	212	/* Under NetBSD/mips, signal handler invocations can be identified by the
	213	designated code sequence that is used to return from a signal handler.
	214	In particular, the return address of a signal handler points to the
	215	following code sequence:
	216
	217	addu a0, sp, 16
	218	li v0, 295 # __sigreturn14
	219	syscall
	220
	221	Each instruction has a unique encoding, so we simply attempt to match
	222	the instruction the PC is pointing to with any of the above instructions.
	223	If there is a hit, we know the offset to the start of the designated
	224	sequence and can then check whether we really are executing in the
	225	signal trampoline. If not, -1 is returned, otherwise the offset from the
	226	start of the return sequence is returned. */
	227
	228	#define RETCODE_NWORDS 3
	229	#define RETCODE_SIZE (RETCODE_NWORDS * 4)
	230
	231	static const unsigned char sigtramp_retcode_mipsel[RETCODE_SIZE] =
	232	{
	233	0x10, 0x00, 0xa4, 0x27, /* addu a0, sp, 16 */
	234	0x27, 0x01, 0x02, 0x24, /* li v0, 295 */
	235	0x0c, 0x00, 0x00, 0x00, /* syscall */
	236	};
	237
	238	static const unsigned char sigtramp_retcode_mipseb[RETCODE_SIZE] =
	239	{
	240	0x27, 0xa4, 0x00, 0x10, /* addu a0, sp, 16 */
	241	0x24, 0x02, 0x01, 0x27, /* li v0, 295 */
	242	0x00, 0x00, 0x00, 0x0c, /* syscall */
	243	};
	244
	245	static LONGEST
4c7d22cb	246	mipsnbsd_sigtramp_offset (struct frame_info *next_frame)
45888261	247	{
4c7d22cb	248	CORE_ADDR pc = frame_pc_unwind (next_frame);
4c6b5505 UW	249	const char *retcode = gdbarch_byte_order (current_gdbarch)
	250	== BFD_ENDIAN_BIG ? sigtramp_retcode_mipseb :
	251	sigtramp_retcode_mipsel;
45888261 JT	252	unsigned char ret[RETCODE_SIZE], w[4];
	253	LONGEST off;
	254	int i;
	255
4c7d22cb	256	if (!safe_frame_unwind_memory (next_frame, pc, w, sizeof (w)))
45888261 JT	257	return -1;
	258
	259	for (i = 0; i < RETCODE_NWORDS; i++)
	260	{
	261	if (memcmp (w, retcode + (i * 4), 4) == 0)
	262	break;
	263	}
	264	if (i == RETCODE_NWORDS)
	265	return -1;
	266
	267	off = i * 4;
	268	pc -= off;
	269
4c7d22cb	270	if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret)))
45888261 JT	271	return -1;
	272
	273	if (memcmp (ret, retcode, RETCODE_SIZE) == 0)
	274	return off;
	275
	276	return -1;
	277	}
	278
45888261	279	/* Figure out where the longjmp will land. We expect that we have
4c7d22cb MK	280	just entered longjmp and haven't yet setup the stack frame, so the
4c7d22cb MK	281	args are still in the argument regs. MIPS_A0_REGNUM points at the
45888261 JT	282	jmp_buf structure from which we extract the PC that we will land
	283	at. The PC is copied into *pc. This routine returns true on
	284	success. */
	285
	286	#define NBSD_MIPS_JB_PC (2 * 4)
1b13c4f6	287	#define NBSD_MIPS_JB_ELEMENT_SIZE mips_isa_regsize (current_gdbarch)
45888261 JT	288	#define NBSD_MIPS_JB_OFFSET (NBSD_MIPS_JB_PC * \
	289	NBSD_MIPS_JB_ELEMENT_SIZE)
	290
	291	static int
60ade65d	292	mipsnbsd_get_longjmp_target (struct frame_info frame, CORE_ADDR pc)
45888261 JT	293	{
	294	CORE_ADDR jb_addr;
	295	char *buf;
	296
	297	buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);
	298
60ade65d	299	jb_addr = get_frame_register_unsigned (frame, MIPS_A0_REGNUM);
45888261 JT	300
	301	if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET, buf,
	302	NBSD_MIPS_JB_ELEMENT_SIZE))
	303	return 0;
	304
7c0b4a20	305	*pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE);
45888261 JT	306
	307	return 1;
	308	}
	309
	310	static int
	311	mipsnbsd_cannot_fetch_register (int regno)
	312	{
4c7d22cb	313	return (regno == MIPS_ZERO_REGNUM
56cea623	314	\|\| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
45888261 JT	315	}
	316
	317	static int
	318	mipsnbsd_cannot_store_register (int regno)
	319	{
4c7d22cb	320	return (regno == MIPS_ZERO_REGNUM
56cea623	321	\|\| regno == mips_regnum (current_gdbarch)->fp_implementation_revision);
45888261 JT	322	}
45888261 JT	323
fabe86c8 MK	324	/* Shared library support. */
	325
	326	/* NetBSD/mips uses a slightly different `struct link_map' than the
45888261	327	other NetBSD platforms. */
fabe86c8	328
45888261	329	static struct link_map_offsets *
fabe86c8	330	mipsnbsd_ilp32_fetch_link_map_offsets (void)
45888261 JT	331	{
	332	static struct link_map_offsets lmo;
	333	static struct link_map_offsets *lmp = NULL;
	334
	335	if (lmp == NULL)
	336	{
	337	lmp = &lmo;
	338
e4cd0d6a MK	339	lmo.r_version_offset = 0;
e4cd0d6a MK	340	lmo.r_version_size = 4;
45888261	341	lmo.r_map_offset = 4;
e4cd0d6a	342	lmo.r_ldsomap_offset = -1;
45888261	343
fabe86c8	344	/* Everything we need is in the first 24 bytes. */
45888261	345	lmo.link_map_size = 24;
4c7d22cb	346	lmo.l_addr_offset = 4;
45888261	347	lmo.l_name_offset = 8;
cc10cae3	348	lmo.l_ld_offset = 12;
45888261	349	lmo.l_next_offset = 16;
45888261	350	lmo.l_prev_offset = 20;
45888261 JT	351	}
	352
	353	return lmp;
	354	}
	355
	356	static struct link_map_offsets *
fabe86c8	357	mipsnbsd_lp64_fetch_link_map_offsets (void)
45888261 JT	358	{
	359	static struct link_map_offsets lmo;
	360	static struct link_map_offsets *lmp = NULL;
	361
	362	if (lmp == NULL)
	363	{
	364	lmp = &lmo;
	365
e4cd0d6a MK	366	lmo.r_version_offset = 0;
	367	lmo.r_version_size = 4;
	368	lmo.r_map_offset = 8;
	369	lmo.r_ldsomap_offset = -1;
45888261	370
fabe86c8	371	/* Everything we need is in the first 40 bytes. */
45888261	372	lmo.link_map_size = 48;
45888261	373	lmo.l_addr_offset = 0;
45888261	374	lmo.l_name_offset = 16;
cc10cae3	375	lmo.l_ld_offset = 24;
45888261	376	lmo.l_next_offset = 32;
45888261	377	lmo.l_prev_offset = 40;
45888261 JT	378	}
	379
	380	return lmp;
	381	}
fabe86c8	382	\f
45888261 JT	383
	384	static void
	385	mipsnbsd_init_abi (struct gdbarch_info info,
	386	struct gdbarch *gdbarch)
	387	{
d1180b0f MK	388	set_gdbarch_regset_from_core_section
	389	(gdbarch, mipsnbsd_regset_from_core_section);
	390
45888261 JT	391	set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);
	392
	393	set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
	394	set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);
	395
	396	set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
	397
fabe86c8 MK	398	/* NetBSD/mips has SVR4-style shared libraries. */
	399	set_solib_svr4_fetch_link_map_offsets
	400	(gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
	401	mipsnbsd_ilp32_fetch_link_map_offsets :
	402	mipsnbsd_lp64_fetch_link_map_offsets));
45888261	403	}
d1180b0f MK	404	\f
	405
	406	static enum gdb_osabi
	407	mipsnbsd_core_osabi_sniffer (bfd *abfd)
	408	{
	409	if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
	410	return GDB_OSABI_NETBSD_ELF;
	411
	412	return GDB_OSABI_UNKNOWN;
	413	}
45888261 JT	414
	415	void
	416	_initialize_mipsnbsd_tdep (void)
	417	{
05816f70	418	gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,
45888261	419	mipsnbsd_init_abi);
45888261	420	}