gdbserver/linux-sh-low.cc

/* GNU/Linux/SH specific low level interface, for the remote server for GDB.
   Copyright (C) 1995-2023 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"

/* Linux target op definitions for the SH architecture.  */

class sh_target : public linux_process_target
{
public:
  const regs_info *get_regs_info () override;

  const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;

protected:
  void low_arch_setup () override;

  bool low_cannot_fetch_register (int regno) override;

  bool low_cannot_store_register (int regno) override;

  bool low_supports_breakpoints () override;

  CORE_ADDR low_get_pc (regcache *regcache) override;

  void low_set_pc (regcache *regcache, CORE_ADDR newpc) override;

  bool low_breakpoint_at (CORE_ADDR pc) override;
};

/* The singleton target ops object.  */

static sh_target the_sh_target;

bool
sh_target::low_supports_breakpoints ()
{
  return true;
}

CORE_ADDR
sh_target::low_get_pc (regcache *regcache)
{
  return linux_get_pc_32bit (regcache);
}

void
sh_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
{
  linux_set_pc_32bit (regcache, pc);
}

/* Defined in auto-generated file reg-sh.c.  */
void init_registers_sh (void);
extern const struct target_desc *tdesc_sh;

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

#include <asm/ptrace.h>

#define sh_num_regs 41

/* Currently, don't check/send MQ.  */
static int sh_regmap[] = {
  0,
  4,
  8,
  12,
  16,
  20,
  24,
  28,
  32,
  36,
  40,
  44,
  48,
  52,
  56,
  60,

  REG_PC * 4,
  REG_PR * 4,
  REG_GBR * 4,
  -1,
  REG_MACH * 4,
  REG_MACL * 4,
  REG_SR * 4,
  REG_FPUL * 4,
  REG_FPSCR * 4,

  REG_FPREG0 * 4 + 0,
  REG_FPREG0 * 4 + 4,
  REG_FPREG0 * 4 + 8,
  REG_FPREG0 * 4 + 12,
  REG_FPREG0 * 4 + 16,
  REG_FPREG0 * 4 + 20,
  REG_FPREG0 * 4 + 24,
  REG_FPREG0 * 4 + 28,
  REG_FPREG0 * 4 + 32,
  REG_FPREG0 * 4 + 36,
  REG_FPREG0 * 4 + 40,
  REG_FPREG0 * 4 + 44,
  REG_FPREG0 * 4 + 48,
  REG_FPREG0 * 4 + 52,
  REG_FPREG0 * 4 + 56,
  REG_FPREG0 * 4 + 60,
};

bool
sh_target::low_cannot_store_register (int regno)
{
  return false;
}

bool
sh_target::low_cannot_fetch_register (int regno)
{
  return false;
}

/* Correct in either endianness, obviously.  */
static const unsigned short sh_breakpoint = 0xc3c3;
#define sh_breakpoint_len 2

/* Implementation of target ops method "sw_breakpoint_from_kind".  */

const gdb_byte *
sh_target::sw_breakpoint_from_kind (int kind, int *size)
{
  *size = sh_breakpoint_len;
  return (const gdb_byte *) &sh_breakpoint;
}

bool
sh_target::low_breakpoint_at (CORE_ADDR where)
{
  unsigned short insn;

  read_memory (where, (unsigned char *) &insn, 2);
  if (insn == sh_breakpoint)
    return true;

  /* If necessary, recognize more trap instructions here.  GDB only uses the
     one.  */
  return false;
}

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

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

  for (i = 0; i < 23; i++)
    if (sh_regmap[i] != -1)
      collect_register (regcache, i, (char *) buf + sh_regmap[i]);
}

static struct regset_info sh_regsets[]
  = { { 0, 0, 0, 0, GENERAL_REGS, sh_fill_gregset, NULL }, NULL_REGSET };

static struct regsets_info sh_regsets_info = {
  sh_regsets, /* regsets */
  0,          /* num_regsets */
  NULL,       /* disabled_regsets */
};

static struct usrregs_info sh_usrregs_info = {
  sh_num_regs,
  sh_regmap,
};

static struct regs_info myregs_info = { NULL, /* regset_bitmap */
                                        &sh_usrregs_info, &sh_regsets_info };

const regs_info *
sh_target::get_regs_info ()
{
  return &myregs_info;
}

void
sh_target::low_arch_setup ()
{
  current_process ()->tdesc = tdesc_sh;
}

/* The linux target ops object.  */

linux_process_target *the_linux_target = &the_sh_target;

void
initialize_low_arch (void)
{
  init_registers_sh ();

  initialize_regsets_info (&sh_regsets_info);
}