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/* Target-dependent code for NetBSD/i386.
Copyright 1988, 1989, 1991, 1992, 1994, 1996, 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 "arch-utils.h"
#include "gdbcore.h"
#include "regcache.h"
#include "regset.h"
#include "osabi.h"
#include "gdb_assert.h"
#include "gdb_string.h"
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "nbsd-tdep.h"
#include "solib-svr4.h"
/* From <machine/reg.h>. */
static int i386nbsd_r_reg_offset[] =
{
0 * 4, /* %eax */
1 * 4, /* %ecx */
2 * 4, /* %edx */
3 * 4, /* %ebx */
4 * 4, /* %esp */
5 * 4, /* %ebp */
6 * 4, /* %esi */
7 * 4, /* %edi */
8 * 4, /* %eip */
9 * 4, /* %eflags */
10 * 4, /* %cs */
11 * 4, /* %ss */
12 * 4, /* %ds */
13 * 4, /* %es */
14 * 4, /* %fs */
15 * 4 /* %gs */
};
static void
i386nbsd_aout_supply_regset (const struct regset *regset,
struct regcache *regcache, int regnum,
const void *regs, size_t len)
{
const struct gdbarch_tdep *tdep = regset->descr;
gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset);
}
static const struct regset *
i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
const char *sect_name,
size_t sect_size)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* NetBSD a.out core dumps don't use seperate register sets for the
general-purpose and floating-point registers. */
if (strcmp (sect_name, ".reg") == 0
&& sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
{
if (tdep->gregset == NULL)
{
tdep->gregset = XMALLOC (struct regset);
tdep->gregset->descr = tdep;
tdep->gregset->supply_regset = i386nbsd_aout_supply_regset;
}
return tdep->gregset;
}
return NULL;
}
/* Under NetBSD/i386, 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:
leal 0x10(%esp), %eax
pushl %eax
pushl %eax
movl $0x127, %eax # __sigreturn14
int $0x80
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_INSN1 0x8d
#define RETCODE_INSN2 0x50
#define RETCODE_INSN3 0x50
#define RETCODE_INSN4 0xb8
#define RETCODE_INSN5 0xcd
#define RETCODE_INSN2_OFF 4
#define RETCODE_INSN3_OFF 5
#define RETCODE_INSN4_OFF 6
#define RETCODE_INSN5_OFF 11
static const unsigned char sigtramp_retcode[] =
{
RETCODE_INSN1, 0x44, 0x24, 0x10,
RETCODE_INSN2,
RETCODE_INSN3,
RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
RETCODE_INSN5, 0x80,
};
static LONGEST
i386nbsd_sigtramp_offset (CORE_ADDR pc)
{
unsigned char ret[sizeof(sigtramp_retcode)], insn;
LONGEST off;
int i;
if (read_memory_nobpt (pc, &insn, 1) != 0)
return -1;
switch (insn)
{
case RETCODE_INSN1:
off = 0;
break;
case RETCODE_INSN2:
/* INSN2 and INSN3 are the same. Read at the location of PC+1
to determine if we're actually looking at INSN2 or INSN3. */
if (read_memory_nobpt (pc + 1, &insn, 1) != 0)
return -1;
if (insn == RETCODE_INSN3)
off = RETCODE_INSN2_OFF;
else
off = RETCODE_INSN3_OFF;
break;
case RETCODE_INSN4:
off = RETCODE_INSN4_OFF;
break;
case RETCODE_INSN5:
off = RETCODE_INSN5_OFF;
break;
default:
return -1;
}
pc -= off;
if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
return -1;
if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
return off;
return -1;
}
static int
i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
return (nbsd_pc_in_sigtramp (pc, name)
|| i386nbsd_sigtramp_offset (pc) >= 0);
}
/* From <machine/signal.h>. */
int i386nbsd_sc_reg_offset[] =
{
10 * 4, /* %eax */
9 * 4, /* %ecx */
8 * 4, /* %edx */
7 * 4, /* %ebx */
14 * 4, /* %esp */
6 * 4, /* %ebp */
5 * 4, /* %esi */
4 * 4, /* %edi */
11 * 4, /* %eip */
13 * 4, /* %eflags */
12 * 4, /* %cs */
15 * 4, /* %ss */
3 * 4, /* %ds */
2 * 4, /* %es */
1 * 4, /* %fs */
0 * 4 /* %gs */
};
static void
i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Obviously NetBSD is BSD-based. */
i386bsd_init_abi (info, gdbarch);
/* NetBSD has a different `struct reg'. */
tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
tdep->sizeof_gregset = 16 * 4;
/* NetBSD has different signal trampoline conventions. */
set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp);
/* FIXME: kettenis/20020906: We should probably provide
NetBSD-specific versions of these functions if we want to
recognize signal trampolines that live on the stack. */
set_gdbarch_sigtramp_start (gdbarch, NULL);
set_gdbarch_sigtramp_end (gdbarch, NULL);
/* NetBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
/* NetBSD has a `struct sigcontext' that's different from the
original 4.3 BSD. */
tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
}
/* NetBSD a.out. */
static void
i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
i386nbsd_init_abi (info, gdbarch);
/* NetBSD a.out has a single register set. */
set_gdbarch_regset_from_core_section
(gdbarch, i386nbsd_aout_regset_from_core_section);
}
/* NetBSD ELF. */
static void
i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* It's still NetBSD. */
i386nbsd_init_abi (info, gdbarch);
/* But ELF-based. */
i386_elf_init_abi (info, gdbarch);
/* NetBSD ELF uses SVR4-style shared libraries. */
set_gdbarch_in_solib_call_trampoline
(gdbarch, generic_in_solib_call_trampoline);
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
/* NetBSD ELF uses -fpcc-struct-return by default. */
tdep->struct_return = pcc_struct_return;
}
void
_initialize_i386nbsd_tdep (void)
{
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
i386nbsdaout_init_abi);
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
i386nbsdelf_init_abi);
}
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