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

/* Low level interface to ptrace, for the remote server for GDB.
   Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   2006, 2007, 2008, 2009, 2010, 2011 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 <sys/ptrace.h>

#include "gdb_proc_service.h"

/* The stack pointer is offset from the stack frame by a BIAS of 2047
   (0x7ff) for 64-bit code.  BIAS is likely to be defined on SPARC
   hosts, so undefine it first.  */
#undef BIAS
#define BIAS 2047

#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif

#define INSN_SIZE 4

#define SPARC_R_REGS_NUM 32
#define SPARC_F_REGS_NUM 48
#define SPARC_CONTROL_REGS_NUM 6

#define sparc_num_regs (SPARC_R_REGS_NUM + SPARC_F_REGS_NUM + SPARC_CONTROL_REGS_NUM)

/* Each offset is multiplied by 8, because of the register size.
   These offsets apply to the buffer sent/filled by ptrace.
   Additionally, the array elements order corresponds to the .dat file, and the
   gdb's registers enumeration order.  */

static int sparc_regmap[] = {
  /* These offsets correspond to GET/SETREGSET.  */
	-1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,	   /* g0 .. g7 */
	7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,	   /* o0 .. o5, sp, o7 */
	-1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,	   /* l0 .. l7 */
	-1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,	   /* i0 .. i5, fp, i7 */

  /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
    0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,	   /*  f0 ..  f7 */
    8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,	   /*  f8 .. f15 */
   16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,	   /* f16 .. f23 */
   24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,	   /* f24 .. f31 */

  /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
   16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,	   /* f32 .. f46 */
   24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,	   /* f48 .. f62 */

   17 *8, /*    pc */
   18 *8, /*   npc */
   16 *8, /* state */
  /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed next to f62.  */
   32 *8, /*   fsr */
      -1, /*  fprs */
  /* Y register is 32-bits length, but gdb takes care of that.  */
   19 *8, /*     y */

};


struct regs_range_t
{
  int regno_start;
  int regno_end;
};

static const struct regs_range_t gregs_ranges[] = {
 {  0, 31 }, /*   g0 .. i7  */
 { 80, 82 }, /*   pc .. state */
 { 84, 85 }  /* fprs .. y */
};

#define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))

static const struct regs_range_t fpregs_ranges[] = {
 { 32, 79 }, /* f0 .. f62  */
 { 83, 83 }  /* fsr */
};

#define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))

/* Defined in auto-generated file reg-sparc64.c.  */
void init_registers_sparc64 (void);

static int
sparc_cannot_store_register (int regno)
{
  return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
}

static int
sparc_cannot_fetch_register (int regno)
{
  return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
}

static void
sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
{
  int i;
  CORE_ADDR addr = 0;
  unsigned char tmp_reg_buf[8];
  const int l0_regno = find_regno("l0");
  const int i7_regno = l0_regno + 15;

  /* These registers have to be stored in the stack.  */
  memcpy(&addr, ((char *) buf) + sparc_regmap[find_regno("sp")], sizeof(addr));

  addr += BIAS;

  for (i = l0_regno; i <= i7_regno; i++)
    {
      collect_register (regcache, i, tmp_reg_buf);
      (*the_target->write_memory) (addr, tmp_reg_buf, sizeof(tmp_reg_buf));
      addr += sizeof(tmp_reg_buf);
    }
}

static void
sparc_fill_gregset (struct regcache *regcache, void *buf)
{
  int i;
  int range;

  for (range = 0; range < N_GREGS_RANGES; range++)
    for (i = gregs_ranges[range].regno_start; i <= gregs_ranges[range].regno_end; i++)
      if (sparc_regmap[i] != -1)
	collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);

  sparc_fill_gregset_to_stack (regcache, buf);
}

static void
sparc_fill_fpregset (struct regcache *regcache, void *buf)
{
  int i;
  int range;

  for (range = 0; range < N_FPREGS_RANGES; range++)
    for (i = fpregs_ranges[range].regno_start; i <= fpregs_ranges[range].regno_end; i++)
      collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);

}

static void
sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
{
  int i;
  CORE_ADDR addr = 0;
  unsigned char tmp_reg_buf[8];
  const int l0_regno = find_regno("l0");
  const int i7_regno = l0_regno + 15;

  /* These registers have to be obtained from the stack.  */
  memcpy(&addr, ((char *) buf) + sparc_regmap[find_regno("sp")], sizeof(addr));

  addr += BIAS;

  for (i = l0_regno; i <= i7_regno; i++)
    {
      (*the_target->read_memory) (addr, tmp_reg_buf, sizeof(tmp_reg_buf));
      supply_register (regcache, i, tmp_reg_buf);
      addr += sizeof(tmp_reg_buf);
    }
}

static void
sparc_store_gregset (struct regcache *regcache, const void *buf)
{
  int i;
  char zerobuf[8];
  int range;

  memset (zerobuf, 0, sizeof(zerobuf));

  for (range = 0; range < N_GREGS_RANGES; range++)
    for (i = gregs_ranges[range].regno_start; i <= gregs_ranges[range].regno_end; i++)
      if (sparc_regmap[i] != -1)
	supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
      else
	supply_register (regcache, i, zerobuf);

  sparc_store_gregset_from_stack (regcache, buf);
}

static void
sparc_store_fpregset (struct regcache *regcache, const void *buf)
{
  int i;
  int range;

  for (range = 0; range < N_FPREGS_RANGES; range++)
    for (i = fpregs_ranges[range].regno_start;
	 i <= fpregs_ranges[range].regno_end;
	 i++)
      supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
}

extern int debug_threads;

static CORE_ADDR
sparc_get_pc (struct regcache *regcache)
{
  unsigned long pc;
  collect_register_by_name (regcache, "pc", &pc);
  if (debug_threads)
    fprintf (stderr, "stop pc is %08lx\n", pc);
  return pc;
}

static const unsigned char sparc_breakpoint[INSN_SIZE] = { 0x91, 0xd0, 0x20, 0x01 };
#define sparc_breakpoint_len INSN_SIZE


static int
sparc_breakpoint_at (CORE_ADDR where)
{
  unsigned char insn[INSN_SIZE];

  (*the_target->read_memory) (where, (unsigned char *) insn, sizeof(insn));

  if (memcmp(sparc_breakpoint, insn, sizeof(insn)) == 0)
    return 1;

  /* If necessary, recognize more trap instructions here.  GDB only uses TRAP Always.  */

  return 0;
}

/* We only place breakpoints in empty marker functions, and thread locking
   is outside of the function.  So rather than importing software single-step,
   we can just run until exit.  */
static CORE_ADDR
sparc_reinsert_addr (void)
{
  struct regcache *regcache = get_thread_regcache (current_inferior, 1);
  CORE_ADDR lr;
  /* O7 is the equivalent to the 'lr' of other archs.  */
  collect_register_by_name (regcache, "o7", &lr);
  return lr;
}


struct regset_info target_regsets[] = {
  { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
    GENERAL_REGS,
    sparc_fill_gregset, sparc_store_gregset },
  { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
    FP_REGS,
    sparc_fill_fpregset, sparc_store_fpregset },
  { 0, 0, 0, -1, -1, NULL, NULL }
};

struct linux_target_ops the_low_target = {
  init_registers_sparc64,
  sparc_num_regs,
  /* No regmap needs to be provided since this impl. doesn't use USRREGS.  */
  NULL,
  sparc_cannot_fetch_register,
  sparc_cannot_store_register,
  sparc_get_pc,
  /* No sparc_set_pc is needed.  */
  NULL,
  (const unsigned char *) sparc_breakpoint,
  sparc_breakpoint_len,
  sparc_reinsert_addr,
  0,
  sparc_breakpoint_at,
  NULL, NULL, NULL, NULL,
  NULL, NULL
};