binutils-gdb/gdb/gdbserver/linux-nios2-low.c

268 lines
6.1 KiB
C

/* GNU/Linux/Nios II specific low level interface, for the remote server for
GDB.
Copyright (C) 2008-2014 Free Software Foundation, Inc.
Contributed by Mentor Graphics, 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 <endian.h>
#include "gdb_proc_service.h"
#include <asm/ptrace.h>
#ifndef PTRACE_GET_THREAD_AREA
#define PTRACE_GET_THREAD_AREA 25
#endif
/* The following definition must agree with the number of registers
defined in "struct user_regs" in GLIBC
(ports/sysdeps/unix/sysv/linux/nios2/sys/user.h), and also with
NIOS2_NUM_REGS in GDB proper. */
#define nios2_num_regs 49
/* Defined in auto-generated file nios2-linux.c. */
void init_registers_nios2_linux (void);
extern const struct target_desc *tdesc_nios2_linux;
/* This union is used to convert between int and byte buffer
representations of register contents. */
union nios2_register
{
unsigned char buf[4];
int reg32;
};
/* Return the ptrace ``address'' of register REGNO. */
static int nios2_regmap[] = {
-1, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23,
24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39,
40, 41, 42, 43, 44, 45, 46, 47,
48,
0
};
/* Implement the arch_setup linux_target_ops method. */
static void
nios2_arch_setup (void)
{
current_process ()->tdesc = tdesc_nios2_linux;
}
/* Implement the cannot_fetch_register linux_target_ops method. */
static int
nios2_cannot_fetch_register (int regno)
{
if (nios2_regmap[regno] == -1)
return 1;
return 0;
}
/* Implement the cannot_store_register linux_target_ops method. */
static int
nios2_cannot_store_register (int regno)
{
if (nios2_regmap[regno] == -1)
return 1;
return 0;
}
/* Implement the get_pc linux_target_ops method. */
static CORE_ADDR
nios2_get_pc (struct regcache *regcache)
{
union nios2_register pc;
collect_register_by_name (regcache, "pc", pc.buf);
return pc.reg32;
}
/* Implement the set_pc linux_target_ops method. */
static void
nios2_set_pc (struct regcache *regcache, CORE_ADDR pc)
{
union nios2_register newpc;
newpc.reg32 = pc;
supply_register_by_name (regcache, "pc", newpc.buf);
}
/* Breakpoint support. */
static const unsigned int nios2_breakpoint = 0x003b6ffa;
#define nios2_breakpoint_len 4
/* Implement the breakpoint_reinsert_addr linux_target_ops method. */
static CORE_ADDR
nios2_reinsert_addr (void)
{
union nios2_register ra;
struct regcache *regcache = get_thread_regcache (current_inferior, 1);
collect_register_by_name (regcache, "ra", ra.buf);
return ra.reg32;
}
/* Implement the breakpoint_at linux_target_ops method. */
static int
nios2_breakpoint_at (CORE_ADDR where)
{
unsigned int insn;
(*the_target->read_memory) (where, (unsigned char *) &insn, 4);
if (insn == nios2_breakpoint)
return 1;
return 0;
}
/* Fetch the thread-local storage pointer for libthread_db. */
ps_err_e
ps_get_thread_area (const 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;
}
#ifdef HAVE_PTRACE_GETREGS
/* Helper functions to collect/supply a single register REGNO. */
static void
nios2_collect_register (struct regcache *regcache, int regno,
union nios2_register *reg)
{
union nios2_register tmp_reg;
collect_register (regcache, regno, &tmp_reg.reg32);
reg->reg32 = tmp_reg.reg32;
}
static void
nios2_supply_register (struct regcache *regcache, int regno,
const union nios2_register *reg)
{
supply_register (regcache, regno, reg->buf);
}
/* We have only a single register set on Nios II. */
static void
nios2_fill_gregset (struct regcache *regcache, void *buf)
{
union nios2_register *regset = buf;
int i;
for (i = 1; i < nios2_num_regs; i++)
nios2_collect_register (regcache, i, regset + i);
}
static void
nios2_store_gregset (struct regcache *regcache, const void *buf)
{
const union nios2_register *regset = buf;
int i;
for (i = 0; i < nios2_num_regs; i++)
nios2_supply_register (regcache, i, regset + i);
}
#endif /* HAVE_PTRACE_GETREGS */
static struct regset_info nios2_regsets[] =
{
#ifdef HAVE_PTRACE_GETREGS
{ PTRACE_GETREGS, PTRACE_SETREGS, 0, nios2_num_regs * 4, GENERAL_REGS,
nios2_fill_gregset, nios2_store_gregset },
#endif /* HAVE_PTRACE_GETREGS */
{ 0, 0, 0, -1, -1, NULL, NULL }
};
static struct regsets_info nios2_regsets_info =
{
nios2_regsets, /* regsets */
0, /* num_regsets */
NULL, /* disabled_regsets */
};
static struct usrregs_info nios2_usrregs_info =
{
nios2_num_regs,
nios2_regmap,
};
static struct regs_info regs_info =
{
NULL, /* regset_bitmap */
&nios2_usrregs_info,
&nios2_regsets_info
};
static const struct regs_info *
nios2_regs_info (void)
{
return &regs_info;
}
struct linux_target_ops the_low_target =
{
nios2_arch_setup,
nios2_regs_info,
nios2_cannot_fetch_register,
nios2_cannot_store_register,
NULL,
nios2_get_pc,
nios2_set_pc,
(const unsigned char *) &nios2_breakpoint,
nios2_breakpoint_len,
nios2_reinsert_addr,
0,
nios2_breakpoint_at,
};
void
initialize_low_arch (void)
{
init_registers_nios2_linux ();
initialize_regsets_info (&nios2_regsets_info);
}