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/* Target-dependent code for QNX Neutrino x86.
Copyright (C) 2003-2022 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 3 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, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "frame.h"
#include "osabi.h"
#include "regcache.h"
#include "target.h"
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "nto-tdep.h"
#include "solib.h"
#include "solib-svr4.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
/* Mapping between the general-purpose registers in `struct xxx'
format and GDB's register cache layout. */
/* From <x86/context.h>. */
static int i386nto_gregset_reg_offset[] =
{
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 /* filler */
};
/* Given a GDB register number REGNUM, return the offset into
Neutrino's register structure or -1 if the register is unknown. */
static int
nto_reg_offset (int regnum)
{
if (regnum >= 0 && regnum < ARRAY_SIZE (i386nto_gregset_reg_offset))
return i386nto_gregset_reg_offset[regnum];
return -1;
}
static void
i386nto_supply_gregset (struct regcache *regcache, char *gpregs)
{
struct gdbarch *gdbarch = regcache->arch ();
i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
gdb_assert (tdep->gregset_reg_offset == i386nto_gregset_reg_offset);
i386_gregset.supply_regset (&i386_gregset, regcache, -1,
gpregs, NUM_GPREGS * 4);
}
static void
i386nto_supply_fpregset (struct regcache *regcache, char *fpregs)
{
if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
i387_supply_fxsave (regcache, -1, fpregs);
else
i387_supply_fsave (regcache, -1, fpregs);
}
static void
i386nto_supply_regset (struct regcache *regcache, int regset, char *data)
{
switch (regset)
{
case NTO_REG_GENERAL:
i386nto_supply_gregset (regcache, data);
break;
case NTO_REG_FLOAT:
i386nto_supply_fpregset (regcache, data);
break;
}
}
static int
i386nto_regset_id (int regno)
{
if (regno == -1)
return NTO_REG_END;
else if (regno < I386_NUM_GREGS)
return NTO_REG_GENERAL;
else if (regno < I386_NUM_GREGS + I387_NUM_REGS)
return NTO_REG_FLOAT;
else if (regno < I386_SSE_NUM_REGS)
return NTO_REG_FLOAT; /* We store xmm registers in fxsave_area. */
return -1; /* Error. */
}
static int
i386nto_register_area (struct gdbarch *gdbarch,
int regno, int regset, unsigned *off)
{
i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
*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, regno_base;
/* The following are flags indicating number in our fxsave_area. */
int first_four = (regno >= I387_FCTRL_REGNUM (tdep)
&& regno <= I387_FISEG_REGNUM (tdep));
int second_four = (regno > I387_FISEG_REGNUM (tdep)
&& regno <= I387_FOP_REGNUM (tdep));
int st_reg = (regno >= I387_ST0_REGNUM (tdep)
&& regno < I387_ST0_REGNUM (tdep) + 8);
int xmm_reg = (regno >= I387_XMM0_REGNUM (tdep)
&& regno < I387_MXCSR_REGNUM (tdep));
if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
{
off_adjust = 32;
regsize = 16;
regset_size = 512;
/* fxsave_area structure. */
if (first_four)
{
/* fpu_control_word, fpu_status_word, fpu_tag_word, fpu_operand
registers. */
regsize = 2; /* Two bytes each. */
off_adjust = 0;
regno_base = I387_FCTRL_REGNUM (tdep);
}
else if (second_four)
{
/* fpu_ip, fpu_cs, fpu_op, fpu_ds registers. */
regsize = 4;
off_adjust = 8;
regno_base = I387_FISEG_REGNUM (tdep) + 1;
}
else if (st_reg)
{
/* ST registers. */
regsize = 16;
off_adjust = 32;
regno_base = I387_ST0_REGNUM (tdep);
}
else if (xmm_reg)
{
/* XMM registers. */
regsize = 16;
off_adjust = 160;
regno_base = I387_XMM0_REGNUM (tdep);
}
else if (regno == I387_MXCSR_REGNUM (tdep))
{
regsize = 4;
off_adjust = 24;
regno_base = I387_MXCSR_REGNUM (tdep);
}
else
{
/* Whole regset. */
gdb_assert (regno == -1);
off_adjust = 0;
regno_base = 0;
regsize = regset_size;
}
}
else
{
regset_size = 108;
/* fsave_area structure. */
if (first_four || second_four)
{
/* fpu_control_word, ... , fpu_ds registers. */
regsize = 4;
off_adjust = 0;
regno_base = I387_FCTRL_REGNUM (tdep);
}
else if (st_reg)
{
/* One of ST registers. */
regsize = 10;
off_adjust = 7 * 4;
regno_base = I387_ST0_REGNUM (tdep);
}
else
{
/* Whole regset. */
gdb_assert (regno == -1);
off_adjust = 0;
regno_base = 0;
regsize = regset_size;
}
}
if (regno != -1)
*off = off_adjust + (regno - regno_base) * regsize;
else
*off = 0;
return regsize;
}
return -1;
}
static int
i386nto_regset_fill (const struct regcache *regcache, 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->raw_collect (regno, data + offset);
}
}
else if (regset == NTO_REG_FLOAT)
{
if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
i387_collect_fxsave (regcache, -1, data);
else
i387_collect_fsave (regcache, -1, data);
}
else
return -1;
return 0;
}
/* Return whether THIS_FRAME corresponds to a QNX Neutrino sigtramp
routine. */
static int
i386nto_sigtramp_p (struct frame_info *this_frame)
{
CORE_ADDR pc = get_frame_pc (this_frame);
const char *name;
find_pc_partial_function (pc, &name, NULL, NULL);
return name && strcmp ("__signalstub", name) == 0;
}
/* Assuming THIS_FRAME is a QNX Neutrino sigtramp routine, return the
address of the associated sigcontext structure. */
static CORE_ADDR
i386nto_sigcontext_addr (struct frame_info *this_frame)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte buf[4];
CORE_ADDR ptrctx;
/* We store __ucontext_t addr in EDI register. */
get_frame_register (this_frame, I386_EDI_REGNUM, buf);
ptrctx = extract_unsigned_integer (buf, 4, byte_order);
ptrctx += 24 /* Context pointer is at this offset. */;
return ptrctx;
}
static void
init_i386nto_ops (void)
{
nto_regset_id = i386nto_regset_id;
nto_supply_gregset = i386nto_supply_gregset;
nto_supply_fpregset = i386nto_supply_fpregset;
nto_supply_altregset = nto_dummy_supply_regset;
nto_supply_regset = i386nto_supply_regset;
nto_register_area = i386nto_register_area;
nto_regset_fill = i386nto_regset_fill;
nto_fetch_link_map_offsets =
svr4_ilp32_fetch_link_map_offsets;
}
static void
i386nto_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
static struct target_so_ops nto_svr4_so_ops;
/* Deal with our strange signals. */
nto_initialize_signals ();
/* 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);
tdep->gregset_reg_offset = i386nto_gregset_reg_offset;
tdep->gregset_num_regs = ARRAY_SIZE (i386nto_gregset_reg_offset);
tdep->sizeof_gregset = NUM_GPREGS * 4;
tdep->sigtramp_p = i386nto_sigtramp_p;
tdep->sigcontext_addr = i386nto_sigcontext_addr;
tdep->sc_reg_offset = i386nto_gregset_reg_offset;
tdep->sc_num_regs = ARRAY_SIZE (i386nto_gregset_reg_offset);
/* 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, svr4_ilp32_fetch_link_map_offsets);
/* Initialize this lazily, to avoid an initialization order
dependency on solib-svr4.c's _initialize routine. */
if (nto_svr4_so_ops.in_dynsym_resolve_code == NULL)
{
nto_svr4_so_ops = svr4_so_ops;
/* Our loader handles solib relocations differently than svr4. */
nto_svr4_so_ops.relocate_section_addresses
= nto_relocate_section_addresses;
/* Supply a nice function to find our solibs. */
nto_svr4_so_ops.find_and_open_solib
= nto_find_and_open_solib;
/* Our linker code is in libc. */
nto_svr4_so_ops.in_dynsym_resolve_code
= nto_in_dynsym_resolve_code;
}
set_gdbarch_so_ops (gdbarch, &nto_svr4_so_ops);
set_gdbarch_wchar_bit (gdbarch, 32);
set_gdbarch_wchar_signed (gdbarch, 0);
}
void _initialize_i386nto_tdep ();
void
_initialize_i386nto_tdep ()
{
init_i386nto_ops ();
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_QNXNTO,
i386nto_init_abi);
gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_elf_flavour,
nto_elf_osabi_sniffer);
}
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