path: root/gdb/gdbserver/linux-ppc-low.c

/* GNU/Linux/PowerPC specific low level interface, for the remote server for
   GDB.
   Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2005, 2007, 2008
   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 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 "server.h"
#include "linux-low.h"

#include <elf.h>
#include <asm/ptrace.h>

/* These are in <asm/cputable.h> in current kernels.  */
#define PPC_FEATURE_HAS_ALTIVEC         0x10000000
#define PPC_FEATURE_HAS_SPE             0x00800000

static unsigned long ppc_hwcap;


/* Defined in auto-generated file reg-ppc.c.  */
void init_registers_ppc (void);
/* Defined in auto-generated file powerpc-32.c.  */
void init_registers_powerpc_32 (void);
/* Defined in auto-generated file powerpc-e500.c.  */
void init_registers_powerpc_e500 (void);
/* Defined in auto-generated file reg-ppc64.c.  */
void init_registers_ppc64 (void);
/* Defined in auto-generated file powerpc-64.c.  */
void init_registers_powerpc_64 (void);

#define ppc_num_regs 71

#ifdef __powerpc64__
/* We use a constant for FPSCR instead of PT_FPSCR, because
   many shipped PPC64 kernels had the wrong value in ptrace.h.  */
static int ppc_regmap[] =
 {PT_R0 * 8,     PT_R1 * 8,     PT_R2 * 8,     PT_R3 * 8,
  PT_R4 * 8,     PT_R5 * 8,     PT_R6 * 8,     PT_R7 * 8,
  PT_R8 * 8,     PT_R9 * 8,     PT_R10 * 8,    PT_R11 * 8,
  PT_R12 * 8,    PT_R13 * 8,    PT_R14 * 8,    PT_R15 * 8,
  PT_R16 * 8,    PT_R17 * 8,    PT_R18 * 8,    PT_R19 * 8,
  PT_R20 * 8,    PT_R21 * 8,    PT_R22 * 8,    PT_R23 * 8,
  PT_R24 * 8,    PT_R25 * 8,    PT_R26 * 8,    PT_R27 * 8,
  PT_R28 * 8,    PT_R29 * 8,    PT_R30 * 8,    PT_R31 * 8,
  PT_FPR0*8,     PT_FPR0*8 + 8, PT_FPR0*8+16,  PT_FPR0*8+24,
  PT_FPR0*8+32,  PT_FPR0*8+40,  PT_FPR0*8+48,  PT_FPR0*8+56,
  PT_FPR0*8+64,  PT_FPR0*8+72,  PT_FPR0*8+80,  PT_FPR0*8+88,
  PT_FPR0*8+96,  PT_FPR0*8+104,  PT_FPR0*8+112,  PT_FPR0*8+120,
  PT_FPR0*8+128, PT_FPR0*8+136,  PT_FPR0*8+144,  PT_FPR0*8+152,
  PT_FPR0*8+160,  PT_FPR0*8+168,  PT_FPR0*8+176,  PT_FPR0*8+184,
  PT_FPR0*8+192,  PT_FPR0*8+200,  PT_FPR0*8+208,  PT_FPR0*8+216,
  PT_FPR0*8+224,  PT_FPR0*8+232,  PT_FPR0*8+240,  PT_FPR0*8+248,
  PT_NIP * 8,    PT_MSR * 8,    PT_CCR * 8,    PT_LNK * 8,
  PT_CTR * 8,    PT_XER * 8,    PT_FPR0*8 + 256 };
#else
/* Currently, don't check/send MQ.  */
static int ppc_regmap[] =
 {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
  PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
  PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
  PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
  PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
  PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
  PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
  PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
  PT_FPR0*4,     PT_FPR0*4 + 8, PT_FPR0*4+16,  PT_FPR0*4+24,
  PT_FPR0*4+32,  PT_FPR0*4+40,  PT_FPR0*4+48,  PT_FPR0*4+56,
  PT_FPR0*4+64,  PT_FPR0*4+72,  PT_FPR0*4+80,  PT_FPR0*4+88,
  PT_FPR0*4+96,  PT_FPR0*4+104,  PT_FPR0*4+112,  PT_FPR0*4+120,
  PT_FPR0*4+128, PT_FPR0*4+136,  PT_FPR0*4+144,  PT_FPR0*4+152,
  PT_FPR0*4+160,  PT_FPR0*4+168,  PT_FPR0*4+176,  PT_FPR0*4+184,
  PT_FPR0*4+192,  PT_FPR0*4+200,  PT_FPR0*4+208,  PT_FPR0*4+216,
  PT_FPR0*4+224,  PT_FPR0*4+232,  PT_FPR0*4+240,  PT_FPR0*4+248,
  PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
  PT_CTR * 4,    PT_XER * 4,    PT_FPSCR * 4
 };

static int ppc_regmap_e500[] =
 {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
  PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
  PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
  PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
  PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
  PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
  PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
  PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  -1,            -1,            -1,            -1,
  PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
  PT_CTR * 4,    PT_XER * 4,    -1
 };
#endif

static int
ppc_cannot_store_register (int regno)
{
#ifndef __powerpc64__
  /* Some kernels do not allow us to store fpscr.  */
  if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE) && regno == find_regno ("fpscr"))
    return 2;
#endif

  return 0;
}

static int
ppc_cannot_fetch_register (int regno)
{
  return 0;
}

static void
ppc_collect_ptrace_register (int regno, char *buf)
{
  int size = register_size (regno);
  if (size < sizeof (long))
    collect_register (regno, buf + sizeof (long) - size);
  else
    collect_register (regno, buf);
}

static void
ppc_supply_ptrace_register (int regno, const char *buf)
{
  int size = register_size (regno);
  if (size < sizeof (long))
    supply_register (regno, buf + sizeof (long) - size);
  else
    supply_register (regno, buf);
}

static CORE_ADDR
ppc_get_pc (void)
{
  if (register_size (0) == 4)
    {
      unsigned int pc;
      collect_register_by_name ("pc", &pc);
      return (CORE_ADDR) pc;
    }
  else
    {
      unsigned long pc;
      collect_register_by_name ("pc", &pc);
      return (CORE_ADDR) pc;
    }
}

static void
ppc_set_pc (CORE_ADDR pc)
{
  if (register_size (0) == 4)
    {
      unsigned int newpc = pc;
      supply_register_by_name ("pc", &newpc);
    }
  else
    {
      unsigned long newpc = pc;
      supply_register_by_name ("pc", &newpc);
    }
}


static int
ppc_get_hwcap (unsigned long *valp)
{
  int wordsize = register_size (0);
  unsigned char *data = alloca (2 * wordsize);
  int offset = 0;

  while ((*the_target->read_auxv) (offset, data, 2 * wordsize) == 2 * wordsize)
    {
      if (wordsize == 4)
	{
	  unsigned int *data_p = (unsigned int *)data;
	  if (data_p[0] == AT_HWCAP)
	    {
	      *valp = data_p[1];
	      return 1;
	    }
	}
      else
	{
	  unsigned long *data_p = (unsigned long *)data;
	  if (data_p[0] == AT_HWCAP)
	    {
	      *valp = data_p[1];
	      return 1;
	    }
	}

      offset += 2 * wordsize;
    }

  *valp = 0;
  return 0;
}

static void
ppc_arch_setup (void)
{
#ifdef __powerpc64__
  long msr;

  /* On a 64-bit host, assume 64-bit inferior process with no
     AltiVec registers.  Reset ppc_hwcap to ensure that the
     collect_register call below does not fail.  */
  init_registers_ppc64 ();
  ppc_hwcap = 0;

  /* Only if the high bit of the MSR is set, we actually have
     a 64-bit inferior.  */
  collect_register_by_name ("msr", &msr);
  if (msr < 0)
    {
      ppc_get_hwcap (&ppc_hwcap);
      if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
	init_registers_powerpc_64 ();

      return;
    }
#endif

  /* OK, we have a 32-bit inferior.  */
  init_registers_ppc ();

  ppc_get_hwcap (&ppc_hwcap);
  if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
    init_registers_powerpc_32 ();

  /* On 32-bit machines, check for SPE registers.
     Set the low target's regmap field as appropriately.  */
#ifndef __powerpc64__
  the_low_target.regmap = ppc_regmap;
  if (ppc_hwcap & PPC_FEATURE_HAS_SPE)
    {
      init_registers_powerpc_e500 ();
      the_low_target.regmap = ppc_regmap_e500;
   }
#endif
}

/* Correct in either endianness.
   This instruction is "twge r2, r2", which GDB uses as a software
   breakpoint.  */
static const unsigned int ppc_breakpoint = 0x7d821008;
#define ppc_breakpoint_len 4

static int
ppc_breakpoint_at (CORE_ADDR where)
{
  unsigned int insn;

  (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
  if (insn == ppc_breakpoint)
    return 1;
  /* If necessary, recognize more trap instructions here.  GDB only uses the
     one.  */
  return 0;
}

/* Provide only a fill function for the general register set.  ps_lgetregs
   will use this for NPTL support.  */

static void ppc_fill_gregset (void *buf)
{
  int i;

  for (i = 0; i < 32; i++)
    ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);

  for (i = 64; i < 70; i++)
    ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);
}

#ifndef PTRACE_GETVRREGS
#define PTRACE_GETVRREGS 18
#define PTRACE_SETVRREGS 19
#endif

#define SIZEOF_VRREGS 33*16+4

static void
ppc_fill_vrregset (void *buf)
{
  int i, base;
  char *regset = buf;

  if (!(ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC))
    return;

  base = find_regno ("vr0");
  for (i = 0; i < 32; i++)
    collect_register (base + i, &regset[i * 16]);

  collect_register_by_name ("vscr", &regset[32 * 16 + 12]);
  collect_register_by_name ("vrsave", &regset[33 * 16]);
}

static void
ppc_store_vrregset (const void *buf)
{
  int i, base;
  const char *regset = buf;

  if (!(ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC))
    return;

  base = find_regno ("vr0");
  for (i = 0; i < 32; i++)
    supply_register (base + i, &regset[i * 16]);

  supply_register_by_name ("vscr", &regset[32 * 16 + 12]);
  supply_register_by_name ("vrsave", &regset[33 * 16]);
}

#ifndef PTRACE_GETEVRREGS
#define PTRACE_GETEVRREGS	20
#define PTRACE_SETEVRREGS	21
#endif

struct gdb_evrregset_t
{
  unsigned long evr[32];
  unsigned long long acc;
  unsigned long spefscr;
};

static void
ppc_fill_evrregset (void *buf)
{
  int i, ev0;
  struct gdb_evrregset_t *regset = buf;

  if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE))
    return;

  ev0 = find_regno ("ev0h");
  for (i = 0; i < 32; i++)
    collect_register (ev0 + i, &regset->evr[i]);

  collect_register_by_name ("acc", &regset->acc);
  collect_register_by_name ("spefscr", &regset->spefscr);
}

static void
ppc_store_evrregset (const void *buf)
{
  int i, ev0;
  const struct gdb_evrregset_t *regset = buf;

  if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE))
    return;

  ev0 = find_regno ("ev0h");
  for (i = 0; i < 32; i++)
    supply_register (ev0 + i, &regset->evr[i]);

  supply_register_by_name ("acc", &regset->acc);
  supply_register_by_name ("spefscr", &regset->spefscr);
}

struct regset_info target_regsets[] = {
  /* List the extra register sets before GENERAL_REGS.  That way we will
     fetch them every time, but still fall back to PTRACE_PEEKUSER for the
     general registers.  Some kernels support these, but not the newer
     PPC_PTRACE_GETREGS.  */
  { PTRACE_GETVRREGS, PTRACE_SETVRREGS, SIZEOF_VRREGS, EXTENDED_REGS,
    ppc_fill_vrregset, ppc_store_vrregset },
  { PTRACE_GETEVRREGS, PTRACE_SETEVRREGS, 32 * 4 + 8 + 4, EXTENDED_REGS,
    ppc_fill_evrregset, ppc_store_evrregset },
  { 0, 0, 0, GENERAL_REGS, ppc_fill_gregset, NULL },
  { 0, 0, -1, -1, NULL, NULL }
};

struct linux_target_ops the_low_target = {
  ppc_arch_setup,
  ppc_num_regs,
  ppc_regmap,
  ppc_cannot_fetch_register,
  ppc_cannot_store_register,
  ppc_get_pc,
  ppc_set_pc,
  (const unsigned char *) &ppc_breakpoint,
  ppc_breakpoint_len,
  NULL,
  0,
  ppc_breakpoint_at,
  NULL,
  NULL,
  NULL,
  NULL,
  ppc_collect_ptrace_register,
  ppc_supply_ptrace_register,
};