[deliverable/binutils-gdb.git] / gdb / m68klinux-tdep.c

/* Motorola m68k target-dependent support for GNU/Linux.

   Copyright 1996, 1998, 2000, 2001, 2002, 2003, 2004
   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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "gdbcore.h"
#include "doublest.h"
#include "floatformat.h"
#include "frame.h"
#include "target.h"
#include "gdb_string.h"
#include "gdbtypes.h"
#include "osabi.h"
#include "regcache.h"
#include "objfiles.h"
#include "symtab.h"
#include "m68k-tdep.h"
#include "trad-frame.h"
#include "frame-unwind.h"
\f
/* Offsets (in target ints) into jmp_buf.  */

#define M68K_LINUX_JB_ELEMENT_SIZE 4
#define M68K_LINUX_JB_PC 7

/* Check whether insn1 and insn2 are parts of a signal trampoline.  */

#define IS_SIGTRAMP(insn1, insn2)					\
  (/* addaw #20,sp; moveq #119,d0; trap #0 */				\
   (insn1 == 0xdefc0014 && insn2 == 0x70774e40)				\
   /* moveq #119,d0; trap #0 */						\
   || insn1 == 0x70774e40)

#define IS_RT_SIGTRAMP(insn1, insn2)					\
  (/* movel #173,d0; trap #0 */						\
   (insn1 == 0x203c0000 && insn2 == 0x00ad4e40)				\
   /* moveq #82,d0; notb d0; trap #0 */					\
   || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))

/* Return non-zero if PC points into the signal trampoline.  For the
   sake of m68k_linux_get_sigtramp_info we also distinguish between
   non-RT and RT signal trampolines.  */

static int
m68k_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
  CORE_ADDR sp;
  char buf[12];
  unsigned long insn0, insn1, insn2;

  if (deprecated_read_memory_nobpt (pc - 4, buf, sizeof (buf)))
    return 0;
  insn1 = extract_unsigned_integer (buf + 4, 4);
  insn2 = extract_unsigned_integer (buf + 8, 4);
  if (IS_SIGTRAMP (insn1, insn2))
    return 1;
  if (IS_RT_SIGTRAMP (insn1, insn2))
    return 2;

  insn0 = extract_unsigned_integer (buf, 4);
  if (IS_SIGTRAMP (insn0, insn1))
    return 1;
  if (IS_RT_SIGTRAMP (insn0, insn1))
    return 2;

  insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16);
  insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16);
  if (IS_SIGTRAMP (insn0, insn1))
    return 1;
  if (IS_RT_SIGTRAMP (insn0, insn1))
    return 2;

  return 0;
}

/* From <asm/sigcontext.h>.  */
static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] =
{
  2 * 4,			/* %d0 */
  3 * 4,			/* %d1 */
  -1,				/* %d2 */
  -1,				/* %d3 */
  -1,				/* %d4 */
  -1,				/* %d5 */
  -1,				/* %d6 */
  -1,				/* %d7 */
  4 * 4,			/* %a0 */
  5 * 4,			/* %a1 */
  -1,				/* %a2 */
  -1,				/* %a3 */
  -1,				/* %a4 */
  -1,				/* %a5 */
  -1,				/* %fp */
  1 * 4,			/* %sp */
  5 * 4 + 2,			/* %sr */
  6 * 4 + 2,			/* %pc */
  8 * 4,			/* %fp0 */
  11 * 4,			/* %fp1 */
  -1,				/* %fp2 */
  -1,				/* %fp3 */
  -1,				/* %fp4 */
  -1,				/* %fp5 */
  -1,				/* %fp6 */
  -1,				/* %fp7 */
  14 * 4,			/* %fpcr */
  15 * 4,			/* %fpsr */
  16 * 4			/* %fpiaddr */
};

/* From <asm/ucontext.h>.  */
static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] =
{
  6 * 4,			/* %d0 */
  7 * 4,			/* %d1 */
  8 * 4,			/* %d2 */
  9 * 4,			/* %d3 */
  10 * 4,			/* %d4 */
  11 * 4,			/* %d5 */
  12 * 4,			/* %d6 */
  13 * 4,			/* %d7 */
  14 * 4,			/* %a0 */
  15 * 4,			/* %a1 */
  16 * 4,			/* %a2 */
  17 * 4,			/* %a3 */
  18 * 4,			/* %a4 */
  19 * 4,			/* %a5 */
  20 * 4,			/* %fp */
  21 * 4,			/* %sp */
  23 * 4,			/* %sr */
  22 * 4,			/* %pc */
  27 * 4,			/* %fp0 */
  30 * 4,			/* %fp1 */
  33 * 4,			/* %fp2 */
  36 * 4,			/* %fp3 */
  39 * 4,			/* %fp4 */
  42 * 4,			/* %fp5 */
  45 * 4,			/* %fp6 */
  48 * 4,			/* %fp7 */
  24 * 4,			/* %fpcr */
  25 * 4,			/* %fpsr */
  26 * 4			/* %fpiaddr */
};


/* Get info about saved registers in sigtramp.  */

struct m68k_linux_sigtramp_info
{
  /* Address of sigcontext.  */
  CORE_ADDR sigcontext_addr;

  /* Offset of registers in `struct sigcontext'.  */
  int *sc_reg_offset;
};

static struct m68k_linux_sigtramp_info
m68k_linux_get_sigtramp_info (struct frame_info *next_frame)
{
  CORE_ADDR sp;
  char buf[4];
  struct m68k_linux_sigtramp_info info;

  frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
  sp = extract_unsigned_integer (buf, 4);

  /* Get sigcontext address, it is the third parameter on the stack.  */
  info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4);

  if (m68k_linux_pc_in_sigtramp (frame_pc_unwind (next_frame), 0) == 2)
    info.sc_reg_offset = m68k_linux_ucontext_reg_offset;
  else
    info.sc_reg_offset = m68k_linux_sigcontext_reg_offset;
  return info;
}

/* Signal trampolines.  */

static struct trad_frame_cache *
m68k_linux_sigtramp_frame_cache (struct frame_info *next_frame,
				 void **this_cache)
{
  struct frame_id this_id;
  struct trad_frame_cache *cache;
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  struct m68k_linux_sigtramp_info info;
  char buf[4];
  int i;

  if (*this_cache)
    return *this_cache;

  cache = trad_frame_cache_zalloc (next_frame);

  /* FIXME: cagney/2004-05-01: This is is long standing broken code.
     The frame ID's code address should be the start-address of the
     signal trampoline and not the current PC within that
     trampoline.  */
  frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
  /* See the end of m68k_push_dummy_call.  */
  this_id = frame_id_build (extract_unsigned_integer (buf, 4) - 4 + 8,
			    frame_pc_unwind (next_frame));
  trad_frame_set_id (cache, this_id);

  info = m68k_linux_get_sigtramp_info (next_frame);

  for (i = 0; i < M68K_NUM_REGS; i++)
    if (info.sc_reg_offset[i] != -1)
      trad_frame_set_reg_addr (cache, i,
			       info.sigcontext_addr + info.sc_reg_offset[i]);

  *this_cache = cache;
  return cache;
}

static void
m68k_linux_sigtramp_frame_this_id (struct frame_info *next_frame,
				   void **this_cache,
				   struct frame_id *this_id)
{
  struct trad_frame_cache *cache =
    m68k_linux_sigtramp_frame_cache (next_frame, this_cache);
  trad_frame_get_id (cache, this_id);
}

static void
m68k_linux_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, void *valuep)
{
  /* Make sure we've initialized the cache.  */
  struct trad_frame_cache *cache =
    m68k_linux_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 m68k_linux_sigtramp_frame_unwind =
{
  SIGTRAMP_FRAME,
  m68k_linux_sigtramp_frame_this_id,
  m68k_linux_sigtramp_frame_prev_register
};

static const struct frame_unwind *
m68k_linux_sigtramp_frame_sniffer (struct frame_info *next_frame)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  char *name;

  find_pc_partial_function (pc, &name, NULL, NULL);
  if (m68k_linux_pc_in_sigtramp (pc, name))
    return &m68k_linux_sigtramp_frame_unwind;

  return NULL;
}

static void
m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  tdep->jb_pc = M68K_LINUX_JB_PC;
  tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE;

  /* GNU/Linux uses a calling convention that's similar to SVR4.  It
     returns integer values in %d0/%di, pointer values in %a0 and
     floating values in %fp0, just like SVR4, but uses %a1 to pass the
     address to store a structure value.  It also returns small
     structures in registers instead of memory.  */
  m68k_svr4_init_abi (info, gdbarch);
  tdep->struct_value_regnum = M68K_A1_REGNUM;
  tdep->struct_return = reg_struct_return;

  frame_unwind_append_sniffer (gdbarch, m68k_linux_sigtramp_frame_sniffer);

  /* Shared library handling.  */
  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
}

void
_initialize_m68k_linux_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
			  m68k_linux_init_abi);
}
Commit	Line	Data
0a595803 AS	1	/* Motorola m68k target-dependent support for GNU/Linux.
0a595803 AS	2
f595cb19 MK	3	Copyright 1996, 1998, 2000, 2001, 2002, 2003, 2004
f595cb19 MK	4	Free Software Foundation, Inc.
0a595803 AS	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"
8de307e0 AS	25	#include "doublest.h"
8de307e0 AS	26	#include "floatformat.h"
0a595803 AS	27	#include "frame.h"
0a595803 AS	28	#include "target.h"
d0b45d99 AS	29	#include "gdb_string.h"
d0b45d99 AS	30	#include "gdbtypes.h"
55809acb	31	#include "osabi.h"
eb2e12d7 AS	32	#include "regcache.h"
	33	#include "objfiles.h"
	34	#include "symtab.h"
d0b45d99	35	#include "m68k-tdep.h"
17e20bce AC	36	#include "trad-frame.h"
17e20bce AC	37	#include "frame-unwind.h"
0a595803	38	\f
eb2e12d7 AS	39	/* Offsets (in target ints) into jmp_buf. */
	40
	41	#define M68K_LINUX_JB_ELEMENT_SIZE 4
	42	#define M68K_LINUX_JB_PC 7
	43
0a595803 AS	44	/* Check whether insn1 and insn2 are parts of a signal trampoline. */
	45
	46	#define IS_SIGTRAMP(insn1, insn2) \
	47	(/* addaw #20,sp; moveq #119,d0; trap #0 */ \
	48	(insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
	49	/* moveq #119,d0; trap #0 */ \
	50	\|\| insn1 == 0x70774e40)
	51
	52	#define IS_RT_SIGTRAMP(insn1, insn2) \
	53	(/* movel #173,d0; trap #0 */ \
	54	(insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
	55	/* moveq #82,d0; notb d0; trap #0 */ \
	56	\|\| (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
	57
8de307e0 AS	58	/* Return non-zero if PC points into the signal trampoline. For the
	59	sake of m68k_linux_get_sigtramp_info we also distinguish between
	60	non-RT and RT signal trampolines. */
0a595803	61
eb2e12d7 AS	62	static int
eb2e12d7 AS	63	m68k_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
0a595803 AS	64	{
	65	CORE_ADDR sp;
	66	char buf[12];
	67	unsigned long insn0, insn1, insn2;
	68
1f602b35	69	if (deprecated_read_memory_nobpt (pc - 4, buf, sizeof (buf)))
0a595803 AS	70	return 0;
	71	insn1 = extract_unsigned_integer (buf + 4, 4);
	72	insn2 = extract_unsigned_integer (buf + 8, 4);
	73	if (IS_SIGTRAMP (insn1, insn2))
	74	return 1;
	75	if (IS_RT_SIGTRAMP (insn1, insn2))
	76	return 2;
	77
	78	insn0 = extract_unsigned_integer (buf, 4);
	79	if (IS_SIGTRAMP (insn0, insn1))
	80	return 1;
	81	if (IS_RT_SIGTRAMP (insn0, insn1))
	82	return 2;
	83
55809acb AS	84	insn0 = ((insn0 << 16) & 0xffffffff) \| (insn1 >> 16);
55809acb AS	85	insn1 = ((insn1 << 16) & 0xffffffff) \| (insn2 >> 16);
0a595803 AS	86	if (IS_SIGTRAMP (insn0, insn1))
	87	return 1;
	88	if (IS_RT_SIGTRAMP (insn0, insn1))
	89	return 2;
	90
	91	return 0;
	92	}
	93
8de307e0 AS	94	/* From <asm/sigcontext.h>. */
8de307e0 AS	95	static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] =
0a595803	96	{
8de307e0 AS	97	2 * 4, /* %d0 */
	98	3 * 4, /* %d1 */
	99	-1, /* %d2 */
	100	-1, /* %d3 */
	101	-1, /* %d4 */
	102	-1, /* %d5 */
	103	-1, /* %d6 */
	104	-1, /* %d7 */
	105	4 * 4, /* %a0 */
	106	5 * 4, /* %a1 */
	107	-1, /* %a2 */
	108	-1, /* %a3 */
	109	-1, /* %a4 */
	110	-1, /* %a5 */
	111	-1, /* %fp */
	112	1 * 4, /* %sp */
	113	5 * 4 + 2, /* %sr */
	114	6 * 4 + 2, /* %pc */
	115	8 * 4, /* %fp0 */
	116	11 * 4, /* %fp1 */
	117	-1, /* %fp2 */
	118	-1, /* %fp3 */
	119	-1, /* %fp4 */
	120	-1, /* %fp5 */
	121	-1, /* %fp6 */
	122	-1, /* %fp7 */
	123	14 * 4, /* %fpcr */
	124	15 * 4, /* %fpsr */
	125	16 * 4 /* %fpiaddr */
	126	};
	127
	128	/* From <asm/ucontext.h>. */
	129	static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] =
	130	{
	131	6 * 4, /* %d0 */
	132	7 * 4, /* %d1 */
	133	8 * 4, /* %d2 */
	134	9 * 4, /* %d3 */
	135	10 * 4, /* %d4 */
	136	11 * 4, /* %d5 */
	137	12 * 4, /* %d6 */
	138	13 * 4, /* %d7 */
	139	14 * 4, /* %a0 */
	140	15 * 4, /* %a1 */
	141	16 * 4, /* %a2 */
	142	17 * 4, /* %a3 */
	143	18 * 4, /* %a4 */
	144	19 * 4, /* %a5 */
	145	20 * 4, /* %fp */
	146	21 * 4, /* %sp */
	147	23 * 4, /* %sr */
	148	22 * 4, /* %pc */
	149	27 * 4, /* %fp0 */
	150	30 * 4, /* %fp1 */
	151	33 * 4, /* %fp2 */
	152	36 * 4, /* %fp3 */
	153	39 * 4, /* %fp4 */
	154	42 * 4, /* %fp5 */
	155	45 * 4, /* %fp6 */
	156	48 * 4, /* %fp7 */
	157	24 * 4, /* %fpcr */
	158	25 * 4, /* %fpsr */
	159	26 * 4 /* %fpiaddr */
	160	};
161
162
163	/* Get info about saved registers in sigtramp. */
164
17e20bce AC	165	struct m68k_linux_sigtramp_info
	166	{
	167	/* Address of sigcontext. */
	168	CORE_ADDR sigcontext_addr;
	169
	170	/* Offset of registers in `struct sigcontext'. */
	171	int *sc_reg_offset;
	172	};
	173
	174	static struct m68k_linux_sigtramp_info
8de307e0 AS	175	m68k_linux_get_sigtramp_info (struct frame_info *next_frame)
	176	{
	177	CORE_ADDR sp;
	178	char buf[4];
17e20bce	179	struct m68k_linux_sigtramp_info info;
8de307e0 AS	180
	181	frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
	182	sp = extract_unsigned_integer (buf, 4);
0a595803 AS	183
0a595803 AS	184	/* Get sigcontext address, it is the third parameter on the stack. */
8de307e0 AS	185	info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4);
	186
	187	if (m68k_linux_pc_in_sigtramp (frame_pc_unwind (next_frame), 0) == 2)
	188	info.sc_reg_offset = m68k_linux_ucontext_reg_offset;
0a595803	189	else
8de307e0 AS	190	info.sc_reg_offset = m68k_linux_sigcontext_reg_offset;
8de307e0 AS	191	return info;
0a595803 AS	192	}
0a595803 AS	193
17e20bce AC	194	/* Signal trampolines. */
	195
	196	static struct trad_frame_cache *
	197	m68k_linux_sigtramp_frame_cache (struct frame_info *next_frame,
	198	void **this_cache)
	199	{
	200	struct frame_id this_id;
	201	struct trad_frame_cache *cache;
	202	struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
	203	struct m68k_linux_sigtramp_info info;
	204	char buf[4];
	205	int i;
	206
	207	if (*this_cache)
	208	return *this_cache;
	209
	210	cache = trad_frame_cache_zalloc (next_frame);
	211
	212	/* FIXME: cagney/2004-05-01: This is is long standing broken code.
	213	The frame ID's code address should be the start-address of the
	214	signal trampoline and not the current PC within that
	215	trampoline. */
	216	frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
	217	/* See the end of m68k_push_dummy_call. */
	218	this_id = frame_id_build (extract_unsigned_integer (buf, 4) - 4 + 8,
	219	frame_pc_unwind (next_frame));
	220	trad_frame_set_id (cache, this_id);
	221
	222	info = m68k_linux_get_sigtramp_info (next_frame);
	223
	224	for (i = 0; i < M68K_NUM_REGS; i++)
	225	if (info.sc_reg_offset[i] != -1)
	226	trad_frame_set_reg_addr (cache, i,
	227	info.sigcontext_addr + info.sc_reg_offset[i]);
	228
	229	*this_cache = cache;
	230	return cache;
	231	}
	232
	233	static void
	234	m68k_linux_sigtramp_frame_this_id (struct frame_info *next_frame,
	235	void **this_cache,
	236	struct frame_id *this_id)
	237	{
	238	struct trad_frame_cache *cache =
	239	m68k_linux_sigtramp_frame_cache (next_frame, this_cache);
	240	trad_frame_get_id (cache, this_id);
	241	}
	242
	243	static void
	244	m68k_linux_sigtramp_frame_prev_register (struct frame_info *next_frame,
	245	void **this_cache,
	246	int regnum, int *optimizedp,
	247	enum lval_type *lvalp,
	248	CORE_ADDR *addrp,
	249	int realnump, void valuep)
	250	{
	251	/* Make sure we've initialized the cache. */
	252	struct trad_frame_cache *cache =
	253	m68k_linux_sigtramp_frame_cache (next_frame, this_cache);
	254	trad_frame_get_register (cache, next_frame, regnum, optimizedp, lvalp,
	255	addrp, realnump, valuep);
	256	}
	257
258	static const struct frame_unwind m68k_linux_sigtramp_frame_unwind =
259	{
260	SIGTRAMP_FRAME,
261	m68k_linux_sigtramp_frame_this_id,
262	m68k_linux_sigtramp_frame_prev_register
263	};
264
265	static const struct frame_unwind *
266	m68k_linux_sigtramp_frame_sniffer (struct frame_info *next_frame)
267	{
268	CORE_ADDR pc = frame_pc_unwind (next_frame);
269	char *name;
270
271	find_pc_partial_function (pc, &name, NULL, NULL);
272	if (m68k_linux_pc_in_sigtramp (pc, name))
273	return &m68k_linux_sigtramp_frame_unwind;
274
275	return NULL;
276	}
277
55809acb AS	278	static void
	279	m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	280	{
eb2e12d7 AS	281	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	282
	283	tdep->jb_pc = M68K_LINUX_JB_PC;
	284	tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE;
	285
f595cb19 MK	286	/* GNU/Linux uses a calling convention that's similar to SVR4. It
	287	returns integer values in %d0/%di, pointer values in %a0 and
	288	floating values in %fp0, just like SVR4, but uses %a1 to pass the
	289	address to store a structure value. It also returns small
	290	structures in registers instead of memory. */
	291	m68k_svr4_init_abi (info, gdbarch);
	292	tdep->struct_value_regnum = M68K_A1_REGNUM;
	293	tdep->struct_return = reg_struct_return;
eb2e12d7	294
17e20bce	295	frame_unwind_append_sniffer (gdbarch, m68k_linux_sigtramp_frame_sniffer);
eb2e12d7 AS	296
eb2e12d7 AS	297	/* Shared library handling. */
eb2e12d7	298	set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
55809acb AS	299	}
	300
	301	void
	302	_initialize_m68k_linux_tdep (void)
	303	{
	304	gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
	305	m68k_linux_init_abi);
	306	}