binutils-gdb/gdb/i386-nto-tdep.c

314 lines
7.8 KiB
C

/* Target-dependent code for QNX Neutrino x86.
Copyright 2003, 2004 Free Software Foundation, Inc.
Contributed by QNX Software Systems Ltd.
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 "gdb_string.h"
#include "gdb_assert.h"
#include "defs.h"
#include "frame.h"
#include "target.h"
#include "regcache.h"
#include "solib-svr4.h"
#include "i386-tdep.h"
#include "nto-tdep.h"
#include "osabi.h"
#include "i387-tdep.h"
#ifndef X86_CPU_FXSR
#define X86_CPU_FXSR (1L << 12)
#endif
/* Why 13? Look in our /usr/include/x86/context.h header at the
x86_cpu_registers structure and you'll see an 'exx' junk register
that is just filler. Don't ask me, ask the kernel guys. */
#define NUM_GPREGS 13
/* Map a GDB register number to an offset in the reg structure. */
static int regmap[] = {
(7 * 4), /* eax */
(6 * 4), /* ecx */
(5 * 4), /* edx */
(4 * 4), /* ebx */
(11 * 4), /* esp */
(2 * 4), /* epb */
(1 * 4), /* esi */
(0 * 4), /* edi */
(8 * 4), /* eip */
(10 * 4), /* eflags */
(9 * 4), /* cs */
(12 * 4), /* ss */
(-1 * 4) /* filler */
};
/* Given a gdb regno, return the offset into Neutrino's register structure
or -1 if register is unknown. */
static int
nto_reg_offset (int regno)
{
return (regno >= 0 && regno < NUM_GPREGS) ? regmap[regno] : -1;
}
static void
i386nto_supply_gregset (char *gpregs)
{
unsigned regno;
int empty = 0;
for (regno = 0; regno < FP0_REGNUM; regno++)
{
int offset = nto_reg_offset (regno);
if (offset == -1)
supply_register (regno, (char *) &empty);
else
supply_register (regno, gpregs + offset);
}
}
static void
i386nto_supply_fpregset (char *fpregs)
{
if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
i387_supply_fxsave (current_regcache, -1, fpregs);
else
i387_supply_fsave (current_regcache, -1, fpregs);
}
static void
i386nto_supply_regset (int regset, char *data)
{
switch (regset)
{
case NTO_REG_GENERAL: /* QNX has different ordering of GP regs than GDB. */
i386nto_supply_gregset (data);
break;
case NTO_REG_FLOAT:
i386nto_supply_fpregset (data);
break;
}
}
static int
i386nto_regset_id (int regno)
{
if (regno == -1)
return NTO_REG_END;
else if (regno < FP0_REGNUM)
return NTO_REG_GENERAL;
else if (regno < FPC_REGNUM)
return NTO_REG_FLOAT;
return -1; /* Error. */
}
static int
i386nto_register_area (int regno, int regset, unsigned *off)
{
int len;
*off = 0;
if (regset == NTO_REG_GENERAL)
{
if (regno == -1)
return NUM_GPREGS * 4;
*off = nto_reg_offset (regno);
if (*off == -1)
return 0;
return 4;
}
else if (regset == NTO_REG_FLOAT)
{
unsigned off_adjust, regsize, regset_size;
if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
{
off_adjust = 32;
regsize = 16;
regset_size = 512;
}
else
{
off_adjust = 28;
regsize = 10;
regset_size = 128;
}
if (regno == -1)
return regset_size;
*off = (regno - FP0_REGNUM) * regsize + off_adjust;
return 10;
/* Why 10 instead of regsize? GDB only stores 10 bytes per FP
register so if we're sending a register back to the target,
we only want pdebug to write 10 bytes so as not to clobber
the reserved 6 bytes in the fxsave structure. */
}
return -1;
}
static int
i386nto_regset_fill (int regset, char *data)
{
if (regset == NTO_REG_GENERAL)
{
int regno;
for (regno = 0; regno < NUM_GPREGS; regno++)
{
int offset = nto_reg_offset (regno);
if (offset != -1)
regcache_collect (regno, data + offset);
}
}
else if (regset == NTO_REG_FLOAT)
{
if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
i387_fill_fxsave (data, -1);
else
i387_fill_fsave (data, -1);
}
else
return -1;
return 0;
}
static struct link_map_offsets *
i386nto_svr4_fetch_link_map_offsets (void)
{
static struct link_map_offsets lmo;
static struct link_map_offsets *lmp = NULL;
if (lmp == NULL)
{
lmp = &lmo;
lmo.r_debug_size = 8; /* The actual size is 20 bytes, but
only 8 bytes are used. */
lmo.r_map_offset = 4;
lmo.r_map_size = 4;
lmo.link_map_size = 20; /* The actual size is 552 bytes, but
only 20 bytes are used. */
lmo.l_addr_offset = 0;
lmo.l_addr_size = 4;
lmo.l_name_offset = 4;
lmo.l_name_size = 4;
lmo.l_next_offset = 12;
lmo.l_next_size = 4;
lmo.l_prev_offset = 16;
lmo.l_prev_size = 4;
}
return lmp;
}
/* Return whether the frame preceding NEXT_FRAME corresponds to a QNX
Neutrino sigtramp routine. */
static int
i386nto_sigtramp_p (struct frame_info *next_frame)
{
CORE_ADDR pc = frame_pc_unwind (next_frame);
char *name;
find_pc_partial_function (pc, &name, NULL, NULL);
return name && strcmp ("__signalstub", name) == 0;
}
#define I386_NTO_SIGCONTEXT_OFFSET 136
/* Assuming NEXT_FRAME is a frame following a QNX Neutrino sigtramp
routine, return the address of the associated sigcontext structure. */
static CORE_ADDR
i386nto_sigcontext_addr (struct frame_info *next_frame)
{
char buf[4];
CORE_ADDR sp;
frame_unwind_register (next_frame, I386_ESP_REGNUM, buf);
sp = extract_unsigned_integer (buf, 4);
return sp + I386_NTO_SIGCONTEXT_OFFSET;
}
static void
init_i386nto_ops (void)
{
current_nto_target.nto_regset_id = i386nto_regset_id;
current_nto_target.nto_supply_gregset = i386nto_supply_gregset;
current_nto_target.nto_supply_fpregset = i386nto_supply_fpregset;
current_nto_target.nto_supply_altregset = nto_dummy_supply_regset;
current_nto_target.nto_supply_regset = i386nto_supply_regset;
current_nto_target.nto_register_area = i386nto_register_area;
current_nto_target.nto_regset_fill = i386nto_regset_fill;
current_nto_target.nto_fetch_link_map_offsets =
i386nto_svr4_fetch_link_map_offsets;
}
static void
i386nto_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* NTO uses ELF. */
i386_elf_init_abi (info, gdbarch);
/* Neutrino rewinds to look more normal. Need to override the i386
default which is [unfortunately] to decrement the PC. */
set_gdbarch_decr_pc_after_break (gdbarch, 0);
/* NTO has shared libraries. */
set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section);
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
tdep->sigtramp_p = i386nto_sigtramp_p;
tdep->sigcontext_addr = i386nto_sigcontext_addr;
tdep->sc_pc_offset = 56;
tdep->sc_sp_offset = 68;
/* Setjmp()'s return PC saved in EDX (5). */
tdep->jb_pc_offset = 20; /* 5x32 bit ints in. */
set_solib_svr4_fetch_link_map_offsets (gdbarch,
i386nto_svr4_fetch_link_map_offsets);
/* Our loader handles solib relocations slightly differently than svr4. */
TARGET_SO_RELOCATE_SECTION_ADDRESSES = nto_relocate_section_addresses;
/* Supply a nice function to find our solibs. */
TARGET_SO_FIND_AND_OPEN_SOLIB = nto_find_and_open_solib;
init_i386nto_ops ();
}
void
_initialize_i386nto_tdep (void)
{
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_QNXNTO,
i386nto_init_abi);
}