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

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

   Copyright 1996, 1998, 2000, 2001, 2002, 2003 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 "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"
\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_frame_saved_pc 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 (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;
}

/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
#define SIGCONTEXT_PC_OFFSET 26

/* Offset to saved PC in ucontext, from <asm/ucontext.h>.  */
#define UCONTEXT_PC_OFFSET 88

/* Get saved user PC for sigtramp from sigcontext or ucontext.  */

static CORE_ADDR
m68k_linux_sigtramp_saved_pc (struct frame_info *frame)
{
  CORE_ADDR sigcontext_addr;
  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
  int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
  int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;

  /* Get sigcontext address, it is the third parameter on the stack.  */
  if (get_next_frame (frame))
    sigcontext_addr
      = read_memory_unsigned_integer (get_frame_base (get_next_frame (frame))
				      + FRAME_ARGS_SKIP
				      + sigcontext_offs,
				      ptrbytes);
  else
    sigcontext_addr
      = read_memory_unsigned_integer (read_register (SP_REGNUM)
				      + sigcontext_offs,
				      ptrbytes);

  /* Don't cause a memory_error when accessing sigcontext in case the
     stack layout has changed or the stack is corrupt.  */
  if (m68k_linux_pc_in_sigtramp (get_frame_pc (frame), 0) == 2)
    target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes);
  else
    target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
  return extract_unsigned_integer (buf, ptrbytes);
}

/* Return the saved program counter for FRAME.  */

static CORE_ADDR
m68k_linux_frame_saved_pc (struct frame_info *frame)
{
  if (get_frame_type (frame) == SIGTRAMP_FRAME)
    return m68k_linux_sigtramp_saved_pc (frame);

  return read_memory_unsigned_integer (get_frame_base (frame) + 4, 4);
}

/* The following definitions are appropriate when using the ELF
   format, where floating point values are returned in fp0, pointer
   values in a0 and other values in d0.  */

/* Extract from an array REGBUF containing the (raw) register state a
   function return value of type TYPE, and copy that, in virtual
   format, into VALBUF.  */

static void
m68k_linux_extract_return_value (struct type *type, char *regbuf, char *valbuf)
{
  if (TYPE_CODE (type) == TYPE_CODE_FLT)
    {
      DEPRECATED_REGISTER_CONVERT_TO_VIRTUAL (FP0_REGNUM, type,
					      regbuf + REGISTER_BYTE (FP0_REGNUM),
					      valbuf);
    }
  else if (TYPE_CODE (type) == TYPE_CODE_PTR)
    memcpy (valbuf, regbuf + REGISTER_BYTE (M68K_A0_REGNUM),
	    TYPE_LENGTH (type));
  else
    memcpy (valbuf,
	    regbuf + (TYPE_LENGTH (type) >= 4 ? 0 : 4 - TYPE_LENGTH (type)),
	    TYPE_LENGTH (type));
}

/* Write into appropriate registers a function return value of type
   TYPE, given in virtual format.  */

static void
m68k_linux_store_return_value (struct type *type, char *valbuf)
{
  if (TYPE_CODE (type) == TYPE_CODE_FLT)
    {
      char raw_buffer[REGISTER_RAW_SIZE (FP0_REGNUM)];
      DEPRECATED_REGISTER_CONVERT_TO_RAW (type, FP0_REGNUM, valbuf, raw_buffer);
      deprecated_write_register_bytes (REGISTER_BYTE (FP0_REGNUM),
				       raw_buffer, TYPE_LENGTH (type));
    }
  else
    {
      if (TYPE_CODE (type) == TYPE_CODE_PTR)
	deprecated_write_register_bytes (REGISTER_BYTE (M68K_A0_REGNUM),
					 valbuf, TYPE_LENGTH (type));
      deprecated_write_register_bytes (0, valbuf, TYPE_LENGTH (type));
    }
}

/* Extract from an array REGBUF containing the (raw) register state
   the address in which a function should return its structure value,
   as a CORE_ADDR.  */

static CORE_ADDR
m68k_linux_extract_struct_value_address (char *regbuf)
{
  return *(CORE_ADDR *) (regbuf + REGISTER_BYTE (M68K_A0_REGNUM));
}

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;

  set_gdbarch_deprecated_frame_saved_pc (gdbarch,
					 m68k_linux_frame_saved_pc);
  set_gdbarch_deprecated_extract_return_value (gdbarch,
					       m68k_linux_extract_return_value);
  set_gdbarch_deprecated_store_return_value (gdbarch,
					     m68k_linux_store_return_value);
  set_gdbarch_deprecated_extract_struct_value_address (gdbarch,
						       m68k_linux_extract_struct_value_address);

  set_gdbarch_pc_in_sigtramp (gdbarch, m68k_linux_pc_in_sigtramp);

  /* Shared library handling.  */
  set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
  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
d0b45d99	3	Copyright 1996, 1998, 2000, 2001, 2002, 2003 Free Software Foundation,
0a595803 AS	4	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 "frame.h"
	26	#include "target.h"
d0b45d99 AS	27	#include "gdb_string.h"
d0b45d99 AS	28	#include "gdbtypes.h"
55809acb	29	#include "osabi.h"
eb2e12d7 AS	30	#include "regcache.h"
	31	#include "objfiles.h"
	32	#include "symtab.h"
d0b45d99	33	#include "m68k-tdep.h"
0a595803	34	\f
eb2e12d7 AS	35	/* Offsets (in target ints) into jmp_buf. */
	36
	37	#define M68K_LINUX_JB_ELEMENT_SIZE 4
	38	#define M68K_LINUX_JB_PC 7
	39
0a595803 AS	40	/* Check whether insn1 and insn2 are parts of a signal trampoline. */
	41
	42	#define IS_SIGTRAMP(insn1, insn2) \
	43	(/* addaw #20,sp; moveq #119,d0; trap #0 */ \
	44	(insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
	45	/* moveq #119,d0; trap #0 */ \
	46	\|\| insn1 == 0x70774e40)
	47
	48	#define IS_RT_SIGTRAMP(insn1, insn2) \
	49	(/* movel #173,d0; trap #0 */ \
	50	(insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
	51	/* moveq #82,d0; notb d0; trap #0 */ \
	52	\|\| (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
	53
	54	/* Return non-zero if PC points into the signal trampoline. For the sake
	55	of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT
	56	signal trampolines. */
	57
eb2e12d7 AS	58	static int
eb2e12d7 AS	59	m68k_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
0a595803 AS	60	{
	61	CORE_ADDR sp;
	62	char buf[12];
	63	unsigned long insn0, insn1, insn2;
	64
	65	if (read_memory_nobpt (pc - 4, buf, sizeof (buf)))
	66	return 0;
	67	insn1 = extract_unsigned_integer (buf + 4, 4);
	68	insn2 = extract_unsigned_integer (buf + 8, 4);
	69	if (IS_SIGTRAMP (insn1, insn2))
	70	return 1;
	71	if (IS_RT_SIGTRAMP (insn1, insn2))
	72	return 2;
	73
	74	insn0 = extract_unsigned_integer (buf, 4);
	75	if (IS_SIGTRAMP (insn0, insn1))
	76	return 1;
	77	if (IS_RT_SIGTRAMP (insn0, insn1))
	78	return 2;
	79
55809acb AS	80	insn0 = ((insn0 << 16) & 0xffffffff) \| (insn1 >> 16);
55809acb AS	81	insn1 = ((insn1 << 16) & 0xffffffff) \| (insn2 >> 16);
0a595803 AS	82	if (IS_SIGTRAMP (insn0, insn1))
	83	return 1;
	84	if (IS_RT_SIGTRAMP (insn0, insn1))
	85	return 2;
	86
	87	return 0;
	88	}
	89
	90	/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
	91	#define SIGCONTEXT_PC_OFFSET 26
	92
	93	/* Offset to saved PC in ucontext, from <asm/ucontext.h>. */
	94	#define UCONTEXT_PC_OFFSET 88
	95
	96	/* Get saved user PC for sigtramp from sigcontext or ucontext. */
	97
	98	static CORE_ADDR
	99	m68k_linux_sigtramp_saved_pc (struct frame_info *frame)
	100	{
	101	CORE_ADDR sigcontext_addr;
	102	char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
	103	int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
	104	int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
	105
	106	/* Get sigcontext address, it is the third parameter on the stack. */
d0b45d99	107	if (get_next_frame (frame))
b5fc49aa	108	sigcontext_addr
d0b45d99	109	= read_memory_unsigned_integer (get_frame_base (get_next_frame (frame))
b5fc49aa AS	110	+ FRAME_ARGS_SKIP
	111	+ sigcontext_offs,
	112	ptrbytes);
0a595803	113	else
b5fc49aa AS	114	sigcontext_addr
	115	= read_memory_unsigned_integer (read_register (SP_REGNUM)
	116	+ sigcontext_offs,
	117	ptrbytes);
0a595803 AS	118
	119	/* Don't cause a memory_error when accessing sigcontext in case the
	120	stack layout has changed or the stack is corrupt. */
eb2e12d7	121	if (m68k_linux_pc_in_sigtramp (get_frame_pc (frame), 0) == 2)
0a595803 AS	122	target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes);
	123	else
	124	target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
	125	return extract_unsigned_integer (buf, ptrbytes);
	126	}
	127
	128	/* Return the saved program counter for FRAME. */
	129
55809acb	130	static CORE_ADDR
0a595803 AS	131	m68k_linux_frame_saved_pc (struct frame_info *frame)
	132	{
	133	if (get_frame_type (frame) == SIGTRAMP_FRAME)
	134	return m68k_linux_sigtramp_saved_pc (frame);
	135
d0b45d99 AS	136	return read_memory_unsigned_integer (get_frame_base (frame) + 4, 4);
	137	}
	138
55809acb AS	139	/* The following definitions are appropriate when using the ELF
	140	format, where floating point values are returned in fp0, pointer
	141	values in a0 and other values in d0. */
	142
	143	/* Extract from an array REGBUF containing the (raw) register state a
	144	function return value of type TYPE, and copy that, in virtual
	145	format, into VALBUF. */
	146
	147	static void
d0b45d99 AS	148	m68k_linux_extract_return_value (struct type type, char regbuf, char *valbuf)
	149	{
	150	if (TYPE_CODE (type) == TYPE_CODE_FLT)
	151	{
781a750d AC	152	DEPRECATED_REGISTER_CONVERT_TO_VIRTUAL (FP0_REGNUM, type,
	153	regbuf + REGISTER_BYTE (FP0_REGNUM),
	154	valbuf);
d0b45d99 AS	155	}
	156	else if (TYPE_CODE (type) == TYPE_CODE_PTR)
	157	memcpy (valbuf, regbuf + REGISTER_BYTE (M68K_A0_REGNUM),
	158	TYPE_LENGTH (type));
	159	else
	160	memcpy (valbuf,
	161	regbuf + (TYPE_LENGTH (type) >= 4 ? 0 : 4 - TYPE_LENGTH (type)),
	162	TYPE_LENGTH (type));
	163	}
	164
55809acb AS	165	/* Write into appropriate registers a function return value of type
	166	TYPE, given in virtual format. */
	167
	168	static void
d0b45d99 AS	169	m68k_linux_store_return_value (struct type type, char valbuf)
	170	{
	171	if (TYPE_CODE (type) == TYPE_CODE_FLT)
	172	{
	173	char raw_buffer[REGISTER_RAW_SIZE (FP0_REGNUM)];
781a750d	174	DEPRECATED_REGISTER_CONVERT_TO_RAW (type, FP0_REGNUM, valbuf, raw_buffer);
d0b45d99 AS	175	deprecated_write_register_bytes (REGISTER_BYTE (FP0_REGNUM),
	176	raw_buffer, TYPE_LENGTH (type));
	177	}
	178	else
	179	{
	180	if (TYPE_CODE (type) == TYPE_CODE_PTR)
	181	deprecated_write_register_bytes (REGISTER_BYTE (M68K_A0_REGNUM),
	182	valbuf, TYPE_LENGTH (type));
	183	deprecated_write_register_bytes (0, valbuf, TYPE_LENGTH (type));
	184	}
	185	}
	186
55809acb AS	187	/* Extract from an array REGBUF containing the (raw) register state
	188	the address in which a function should return its structure value,
	189	as a CORE_ADDR. */
	190
	191	static CORE_ADDR
d0b45d99 AS	192	m68k_linux_extract_struct_value_address (char *regbuf)
	193	{
	194	return (CORE_ADDR ) (regbuf + REGISTER_BYTE (M68K_A0_REGNUM));
0a595803	195	}
55809acb AS	196
	197	static void
	198	m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	199	{
eb2e12d7 AS	200	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	201
	202	tdep->jb_pc = M68K_LINUX_JB_PC;
	203	tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE;
	204
55809acb AS	205	set_gdbarch_deprecated_frame_saved_pc (gdbarch,
	206	m68k_linux_frame_saved_pc);
	207	set_gdbarch_deprecated_extract_return_value (gdbarch,
	208	m68k_linux_extract_return_value);
	209	set_gdbarch_deprecated_store_return_value (gdbarch,
	210	m68k_linux_store_return_value);
	211	set_gdbarch_deprecated_extract_struct_value_address (gdbarch,
	212	m68k_linux_extract_struct_value_address);
eb2e12d7 AS	213
	214	set_gdbarch_pc_in_sigtramp (gdbarch, m68k_linux_pc_in_sigtramp);
	215
	216	/* Shared library handling. */
	217	set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
	218	set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
55809acb AS	219	}
	220
	221	void
	222	_initialize_m68k_linux_tdep (void)
	223	{
	224	gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
	225	m68k_linux_init_abi);
	226	}