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/* 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"
/* 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);
}
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