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/* Target-dependent code for GNU/Linux on Nios II.
Copyright (C) 2012-2014 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 "defs.h"
#include "frame.h"
#include "osabi.h"
#include "solib-svr4.h"
#include "trad-frame.h"
#include "tramp-frame.h"
#include "symtab.h"
#include "regset.h"
#include "regcache.h"
#include "linux-tdep.h"
#include "glibc-tdep.h"
#include "nios2-tdep.h"
#include "features/nios2-linux.c"
/* Core file and register set support. */
/* Map from the normal register enumeration order to the order that
registers appear in core files, which corresponds to the order
of the register slots in the kernel's struct pt_regs. */
static const int reg_offsets[NIOS2_NUM_REGS] =
{
-1, 8, 9, 10, 11, 12, 13, 14, /* r0 - r7 */
0, 1, 2, 3, 4, 5, 6, 7, /* r8 - r15 */
23, 24, 25, 26, 27, 28, 29, 30, /* r16 - r23 */
-1, -1, 19, 18, 17, 21, -1, 16, /* et bt gp sp fp ea sstatus ra */
21, /* pc */
-1, 20, -1, -1, -1, -1, -1, -1, /* status estatus ... */
-1, -1, -1, -1, -1, -1, -1, -1
};
/* General register set size. Should match sizeof (struct pt_regs) +
sizeof (struct switch_stack) from the NIOS2 Linux kernel patch. */
#define NIOS2_GREGS_SIZE (4 * 34)
/* Implement the supply_regset hook for core files. */
static void
nios2_supply_gregset (const struct regset *regset,
struct regcache *regcache,
int regnum, const void *gregs_buf, size_t len)
{
const gdb_byte *gregs = gregs_buf;
int regno;
static const gdb_byte zero_buf[4] = {0, 0, 0, 0};
for (regno = NIOS2_Z_REGNUM; regno <= NIOS2_MPUACC_REGNUM; regno++)
if (regnum == -1 || regnum == regno)
{
if (reg_offsets[regno] != -1)
regcache_raw_supply (regcache, regno,
gregs + 4 * reg_offsets[regno]);
else
regcache_raw_supply (regcache, regno, zero_buf);
}
}
/* Implement the collect_regset hook for core files. */
static void
nios2_collect_gregset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *gregs_buf, size_t len)
{
gdb_byte *gregs = gregs_buf;
int regno;
for (regno = NIOS2_Z_REGNUM; regno <= NIOS2_MPUACC_REGNUM; regno++)
if (regnum == -1 || regnum == regno)
{
if (reg_offsets[regno] != -1)
regcache_raw_collect (regcache, regno,
gregs + 4 * reg_offsets[regno]);
}
}
static const struct regset nios2_core_regset =
{
NULL,
nios2_supply_gregset,
nios2_collect_gregset
};
/* Iterate over core file register note sections. */
static void
nios2_iterate_over_regset_sections (struct gdbarch *gdbarch,
iterate_over_regset_sections_cb *cb,
void *cb_data,
const struct regcache *regcache)
{
cb (".reg", NIOS2_GREGS_SIZE, &nios2_core_regset, NULL, cb_data);
}
/* Initialize a trad-frame cache corresponding to the tramp-frame.
FUNC is the address of the instruction TRAMP[0] in memory. */
static void
nios2_linux_rt_sigreturn_init (const struct tramp_frame *self,
struct frame_info *next_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
CORE_ADDR base = func + 41 * 4;
int i;
for (i = 0; i < 23; i++)
trad_frame_set_reg_addr (this_cache, i + 1, base + i * 4);
trad_frame_set_reg_addr (this_cache, NIOS2_RA_REGNUM, base + 23 * 4);
trad_frame_set_reg_addr (this_cache, NIOS2_FP_REGNUM, base + 24 * 4);
trad_frame_set_reg_addr (this_cache, NIOS2_GP_REGNUM, base + 25 * 4);
trad_frame_set_reg_addr (this_cache, NIOS2_PC_REGNUM, base + 27 * 4);
trad_frame_set_reg_addr (this_cache, NIOS2_SP_REGNUM, base + 28 * 4);
/* Save a frame ID. */
trad_frame_set_id (this_cache, frame_id_build (base, func));
}
static struct tramp_frame nios2_linux_rt_sigreturn_tramp_frame =
{
SIGTRAMP_FRAME,
4,
{
{ 0x00800004 | (139 << 6), -1 }, /* movi r2,__NR_rt_sigreturn */
{ 0x003b683a, -1 }, /* trap */
{ TRAMP_SENTINEL_INSN }
},
nios2_linux_rt_sigreturn_init
};
/* When FRAME is at a syscall instruction, return the PC of the next
instruction to be executed. */
static CORE_ADDR
nios2_linux_syscall_next_pc (struct frame_info *frame)
{
CORE_ADDR pc = get_frame_pc (frame);
ULONGEST syscall_nr = get_frame_register_unsigned (frame, NIOS2_R2_REGNUM);
/* If we are about to make a sigreturn syscall, use the unwinder to
decode the signal frame. */
if (syscall_nr == 139 /* rt_sigreturn */)
return frame_unwind_caller_pc (frame);
return pc + NIOS2_OPCODE_SIZE;
}
/* Hook function for gdbarch_register_osabi. */
static void
nios2_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
linux_init_abi (info, gdbarch);
/* Shared library handling. */
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
set_solib_svr4_fetch_link_map_offsets (gdbarch,
svr4_ilp32_fetch_link_map_offsets);
/* Enable TLS support. */
set_gdbarch_fetch_tls_load_module_address (gdbarch,
svr4_fetch_objfile_link_map);
/* Core file support. */
set_gdbarch_iterate_over_regset_sections
(gdbarch, nios2_iterate_over_regset_sections);
/* Linux signal frame unwinders. */
tramp_frame_prepend_unwinder (gdbarch,
&nios2_linux_rt_sigreturn_tramp_frame);
tdep->syscall_next_pc = nios2_linux_syscall_next_pc;
/* Index of target address word in glibc jmp_buf. */
tdep->jb_pc = 10;
}
/* Provide a prototype to silence -Wmissing-prototypes. */
extern initialize_file_ftype _initialize_nios2_linux_tdep;
void
_initialize_nios2_linux_tdep (void)
{
gdbarch_register_osabi (bfd_arch_nios2, 0, GDB_OSABI_LINUX,
nios2_linux_init_abi);
initialize_tdesc_nios2_linux ();
}
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