/* GNU/Linux/m68k 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 . */
#include "server.h"
#include "linux-low.h"
/* Linux target op definitions for the m68k architecture. */
class m68k_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;
int low_decr_pc_after_break () override;
bool low_breakpoint_at (CORE_ADDR pc) override;
};
/* The singleton target ops object. */
static m68k_target the_m68k_target;
bool
m68k_target::low_supports_breakpoints ()
{
return true;
}
CORE_ADDR
m68k_target::low_get_pc (regcache *regcache)
{
return linux_get_pc_32bit (regcache);
}
void
m68k_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
{
linux_set_pc_32bit (regcache, pc);
}
int
m68k_target::low_decr_pc_after_break ()
{
return 2;
}
/* Defined in auto-generated file reg-m68k.c. */
void init_registers_m68k (void);
extern const struct target_desc *tdesc_m68k;
#ifdef HAVE_SYS_REG_H
#include
#endif
#define m68k_num_regs 29
#define m68k_num_gregs 18
/* This table must line up with REGISTER_NAMES in tm-m68k.h */
static int m68k_regmap[] =
{
#ifdef PT_D0
PT_D0 * 4, PT_D1 * 4, PT_D2 * 4, PT_D3 * 4,
PT_D4 * 4, PT_D5 * 4, PT_D6 * 4, PT_D7 * 4,
PT_A0 * 4, PT_A1 * 4, PT_A2 * 4, PT_A3 * 4,
PT_A4 * 4, PT_A5 * 4, PT_A6 * 4, PT_USP * 4,
PT_SR * 4, PT_PC * 4,
#else
14 * 4, 0 * 4, 1 * 4, 2 * 4, 3 * 4, 4 * 4, 5 * 4, 6 * 4,
7 * 4, 8 * 4, 9 * 4, 10 * 4, 11 * 4, 12 * 4, 13 * 4, 15 * 4,
17 * 4, 18 * 4,
#endif
#ifdef PT_FP0
PT_FP0 * 4, PT_FP1 * 4, PT_FP2 * 4, PT_FP3 * 4,
PT_FP4 * 4, PT_FP5 * 4, PT_FP6 * 4, PT_FP7 * 4,
PT_FPCR * 4, PT_FPSR * 4, PT_FPIAR * 4
#else
21 * 4, 24 * 4, 27 * 4, 30 * 4, 33 * 4, 36 * 4,
39 * 4, 42 * 4, 45 * 4, 46 * 4, 47 * 4
#endif
};
bool
m68k_target::low_cannot_store_register (int regno)
{
return (regno >= m68k_num_regs);
}
bool
m68k_target::low_cannot_fetch_register (int regno)
{
return (regno >= m68k_num_regs);
}
#ifdef HAVE_PTRACE_GETREGS
#include
#include "nat/gdb_ptrace.h"
static void
m68k_fill_gregset (struct regcache *regcache, void *buf)
{
int i;
for (i = 0; i < m68k_num_gregs; i++)
collect_register (regcache, i, (char *) buf + m68k_regmap[i]);
}
static void
m68k_store_gregset (struct regcache *regcache, const void *buf)
{
int i;
for (i = 0; i < m68k_num_gregs; i++)
supply_register (regcache, i, (const char *) buf + m68k_regmap[i]);
}
static void
m68k_fill_fpregset (struct regcache *regcache, void *buf)
{
int i;
for (i = m68k_num_gregs; i < m68k_num_regs; i++)
collect_register (regcache, i, ((char *) buf
+ (m68k_regmap[i] - m68k_regmap[m68k_num_gregs])));
}
static void
m68k_store_fpregset (struct regcache *regcache, const void *buf)
{
int i;
for (i = m68k_num_gregs; i < m68k_num_regs; i++)
supply_register (regcache, i, ((const char *) buf
+ (m68k_regmap[i] - m68k_regmap[m68k_num_gregs])));
}
#endif /* HAVE_PTRACE_GETREGS */
static struct regset_info m68k_regsets[] = {
#ifdef HAVE_PTRACE_GETREGS
{ PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
GENERAL_REGS,
m68k_fill_gregset, m68k_store_gregset },
{ PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (elf_fpregset_t),
FP_REGS,
m68k_fill_fpregset, m68k_store_fpregset },
#endif /* HAVE_PTRACE_GETREGS */
NULL_REGSET
};
static const gdb_byte m68k_breakpoint[] = { 0x4E, 0x4F };
#define m68k_breakpoint_len 2
/* Implementation of target ops method "sw_breakpoint_from_kind". */
const gdb_byte *
m68k_target::sw_breakpoint_from_kind (int kind, int *size)
{
*size = m68k_breakpoint_len;
return m68k_breakpoint;
}
bool
m68k_target::low_breakpoint_at (CORE_ADDR pc)
{
unsigned char c[2];
read_inferior_memory (pc, c, 2);
if (c[0] == 0x4E && c[1] == 0x4F)
return true;
return false;
}
#include
#ifdef PTRACE_GET_THREAD_AREA
/* Fetch the thread-local storage pointer for libthread_db. */
ps_err_e
ps_get_thread_area (struct ps_prochandle *ph,
lwpid_t lwpid, int idx, void **base)
{
if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
return PS_ERR;
/* IDX is the bias from the thread pointer to the beginning of the
thread descriptor. It has to be subtracted due to implementation
quirks in libthread_db. */
*base = (void *) ((char *)*base - idx);
return PS_OK;
}
#endif /* PTRACE_GET_THREAD_AREA */
static struct regsets_info m68k_regsets_info =
{
m68k_regsets, /* regsets */
0, /* num_regsets */
NULL, /* disabled_regsets */
};
static struct usrregs_info m68k_usrregs_info =
{
m68k_num_regs,
m68k_regmap,
};
static struct regs_info myregs_info =
{
NULL, /* regset_bitmap */
&m68k_usrregs_info,
&m68k_regsets_info
};
const regs_info *
m68k_target::get_regs_info ()
{
return &myregs_info;
}
void
m68k_target::low_arch_setup ()
{
current_process ()->tdesc = tdesc_m68k;
}
/* The linux target ops object. */
linux_process_target *the_linux_target = &the_m68k_target;
void
initialize_low_arch (void)
{
/* Initialize the Linux target descriptions. */
init_registers_m68k ();
initialize_regsets_info (&m68k_regsets_info);
}