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/* 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 "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"
/* 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 (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. */
static struct m68k_sigtramp_info
m68k_linux_get_sigtramp_info (struct frame_info *next_frame)
{
CORE_ADDR sp;
char buf[4];
struct m68k_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;
}
/* Extract from an array REGBUF containing the (raw) register state, a
function return value of TYPE, and copy that, in virtual format,
into VALBUF. */
static void
m68k_linux_extract_return_value (struct type *type, struct regcache *regcache,
void *valbuf)
{
int len = TYPE_LENGTH (type);
char buf[M68K_MAX_REGISTER_SIZE];
if (TYPE_CODE (type) == TYPE_CODE_STRUCT
&& TYPE_NFIELDS (type) == 1)
{
m68k_linux_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache,
valbuf);
return;
}
if (TYPE_CODE (type) == TYPE_CODE_FLT)
{
regcache_raw_read (regcache, M68K_FP0_REGNUM, buf);
convert_typed_floating (buf, builtin_type_m68881_ext, valbuf, type);
}
else if (TYPE_CODE (type) == TYPE_CODE_PTR)
regcache_raw_read (regcache, M68K_A0_REGNUM, valbuf);
else
{
if (len <= 4)
{
regcache_raw_read (regcache, M68K_D0_REGNUM, buf);
memcpy (valbuf, buf + (4 - len), len);
}
else if (len <= 8)
{
regcache_raw_read (regcache, M68K_D0_REGNUM, buf);
memcpy (valbuf, buf + (8 - len), len - 4);
regcache_raw_read (regcache, M68K_D1_REGNUM,
(char *) valbuf + (len - 4));
}
else
internal_error (__FILE__, __LINE__,
"Cannot extract return value of %d bytes long.", len);
}
}
/* Write into the appropriate registers a function return value stored
in VALBUF of type TYPE, given in virtual format. */
static void
m68k_linux_store_return_value (struct type *type, struct regcache *regcache,
const void *valbuf)
{
int len = TYPE_LENGTH (type);
if (TYPE_CODE (type) == TYPE_CODE_STRUCT
&& TYPE_NFIELDS (type) == 1)
{
m68k_linux_store_return_value (TYPE_FIELD_TYPE (type, 0), regcache,
valbuf);
return;
}
if (TYPE_CODE (type) == TYPE_CODE_FLT)
{
char buf[M68K_MAX_REGISTER_SIZE];
convert_typed_floating (valbuf, type, buf, builtin_type_m68881_ext);
regcache_raw_write (regcache, M68K_FP0_REGNUM, buf);
}
else if (TYPE_CODE (type) == TYPE_CODE_PTR)
regcache_raw_write (regcache, M68K_A0_REGNUM, valbuf);
else
{
if (len <= 4)
regcache_raw_write_part (regcache, M68K_D0_REGNUM,
4 - len, len, valbuf);
else if (len <= 8)
{
regcache_raw_write_part (regcache, M68K_D1_REGNUM, 8 - len,
len - 4, valbuf);
regcache_raw_write (regcache, M68K_D0_REGNUM,
(char *) valbuf + (len - 4));
}
else
internal_error (__FILE__, __LINE__,
"Cannot store return value of %d bytes long.", len);
}
}
/* 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 (struct regcache *regcache)
{
char buf[4];
regcache_cooked_read (regcache, M68K_A0_REGNUM, buf);
return extract_unsigned_integer (buf, 4);
}
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;
tdep->get_sigtramp_info = m68k_linux_get_sigtramp_info;
tdep->struct_return = reg_struct_return;
set_gdbarch_extract_return_value (gdbarch, m68k_linux_extract_return_value);
set_gdbarch_store_return_value (gdbarch, m68k_linux_store_return_value);
set_gdbarch_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);
}
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