binutils-gdb/gdb/alphanbsd-tdep.c
2004-05-10 18:36:52 +00:00

233 lines
6.5 KiB
C

/* Target-dependent code for NetBSD/Alpha.
Copyright 2002, 2003, 2004 Free Software Foundation, Inc.
Contributed by Wasabi Systems, 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 "regcache.h"
#include "value.h"
#include "osabi.h"
#include "gdb_string.h"
#include "alpha-tdep.h"
#include "alphabsd-tdep.h"
#include "nbsd-tdep.h"
#include "solib-svr4.h"
static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
CORE_ADDR ignore)
{
char *regs, *fpregs;
int regno;
/* Table to map a gdb register number to a trapframe register index. */
static const int regmap[] =
{
0, 1, 2, 3,
4, 5, 6, 7,
8, 9, 10, 11,
12, 13, 14, 15,
30, 31, 32, 16,
17, 18, 19, 20,
21, 22, 23, 24,
25, 29, 26
};
#define SIZEOF_TRAPFRAME (33 * 8)
/* We get everything from one section. */
if (which != 0)
return;
regs = core_reg_sect;
fpregs = core_reg_sect + SIZEOF_TRAPFRAME;
if (core_reg_size < (SIZEOF_TRAPFRAME + SIZEOF_STRUCT_FPREG))
{
warning ("Wrong size register set in core file.");
return;
}
/* Integer registers. */
for (regno = 0; regno < ALPHA_ZERO_REGNUM; regno++)
supply_register (regno, regs + (regmap[regno] * 8));
supply_register (ALPHA_ZERO_REGNUM, NULL);
supply_register (PC_REGNUM, regs + (28 * 8));
/* Floating point registers. */
alphabsd_supply_fpreg (fpregs, -1);
}
static void
fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, int which,
CORE_ADDR ignore)
{
switch (which)
{
case 0: /* Integer registers. */
if (core_reg_size != SIZEOF_STRUCT_REG)
warning ("Wrong size register set in core file.");
else
alphabsd_supply_reg (core_reg_sect, -1);
break;
case 2: /* Floating point registers. */
if (core_reg_size != SIZEOF_STRUCT_FPREG)
warning ("Wrong size FP register set in core file.");
else
alphabsd_supply_fpreg (core_reg_sect, -1);
break;
default:
/* Don't know what kind of register request this is; just ignore it. */
break;
}
}
static struct core_fns alphanbsd_core_fns =
{
bfd_target_unknown_flavour, /* core_flavour */
default_check_format, /* check_format */
default_core_sniffer, /* core_sniffer */
fetch_core_registers, /* core_read_registers */
NULL /* next */
};
static struct core_fns alphanbsd_elfcore_fns =
{
bfd_target_elf_flavour, /* core_flavour */
default_check_format, /* check_format */
default_core_sniffer, /* core_sniffer */
fetch_elfcore_registers, /* core_read_registers */
NULL /* next */
};
/* Under NetBSD/alpha, 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:
ldq a0, 0(sp)
lda sp, 16(sp)
lda v0, 295(zero) # __sigreturn14
call_pal callsys
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. */
static const unsigned char sigtramp_retcode[] =
{
0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */
0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */
0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */
0x83, 0x00, 0x00, 0x00, /* call_pal callsys */
};
#define RETCODE_NWORDS 4
#define RETCODE_SIZE (RETCODE_NWORDS * 4)
LONGEST
alphanbsd_sigtramp_offset (CORE_ADDR pc)
{
unsigned char ret[RETCODE_SIZE], w[4];
LONGEST off;
int i;
if (read_memory_nobpt (pc, (char *) w, 4) != 0)
return -1;
for (i = 0; i < RETCODE_NWORDS; i++)
{
if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0)
break;
}
if (i == RETCODE_NWORDS)
return (-1);
off = i * 4;
pc -= off;
if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
return -1;
if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0)
return off;
return -1;
}
static int
alphanbsd_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
{
return (nbsd_pc_in_sigtramp (pc, func_name)
|| alphanbsd_sigtramp_offset (pc) >= 0);
}
static CORE_ADDR
alphanbsd_sigcontext_addr (struct frame_info *frame)
{
/* FIXME: This is not correct for all versions of NetBSD/alpha.
We will probably need to disassemble the trampoline to figure
out which trampoline frame type we have. */
return get_frame_base (frame);
}
static void
alphanbsd_init_abi (struct gdbarch_info info,
struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Hook into the DWARF CFI frame unwinder. */
alpha_dwarf2_init_abi (info, gdbarch);
/* Hook into the MDEBUG frame unwinder. */
alpha_mdebug_init_abi (info, gdbarch);
/* NetBSD/alpha does not provide single step support via ptrace(2); we
must use software single-stepping. */
set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
set_solib_svr4_fetch_link_map_offsets (gdbarch,
nbsd_lp64_solib_svr4_fetch_link_map_offsets);
tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset;
tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp;
tdep->sigcontext_addr = alphanbsd_sigcontext_addr;
tdep->jb_pc = 2;
tdep->jb_elt_size = 8;
}
void
_initialize_alphanbsd_tdep (void)
{
gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD_ELF,
alphanbsd_init_abi);
deprecated_add_core_fns (&alphanbsd_core_fns);
deprecated_add_core_fns (&alphanbsd_elfcore_fns);
}