/* Target-machine dependent code for Nios II, for GDB.
Copyright (C) 2012-2013 Free Software Foundation, Inc.
Contributed by Peter Brookes (pbrookes@altera.com)
and Andrew Draper (adraper@altera.com).
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 . */
#include "defs.h"
#include "frame.h"
#include "frame-unwind.h"
#include "frame-base.h"
#include "trad-frame.h"
#include "dwarf2-frame.h"
#include "symtab.h"
#include "inferior.h"
#include "gdbtypes.h"
#include "gdbcore.h"
#include "gdbcmd.h"
#include "osabi.h"
#include "target.h"
#include "dis-asm.h"
#include "regcache.h"
#include "value.h"
#include "symfile.h"
#include "arch-utils.h"
#include "floatformat.h"
#include "gdb_assert.h"
#include "infcall.h"
#include "regset.h"
#include "target-descriptions.h"
/* To get entry_point_address. */
#include "objfiles.h"
/* Nios II ISA specific encodings and macros. */
#include "opcode/nios2.h"
/* Nios II specific header. */
#include "nios2-tdep.h"
#include "features/nios2.c"
/* Control debugging information emitted in this file. */
static int nios2_debug = 0;
/* The following structures are used in the cache for prologue
analysis; see the reg_value and reg_saved tables in
struct nios2_unwind_cache, respectively. */
/* struct reg_value is used to record that a register has the same value
as reg at the given offset from the start of a function. */
struct reg_value
{
int reg;
unsigned int offset;
};
/* struct reg_saved is used to record that a register value has been saved at
basereg + addr, for basereg >= 0. If basereg < 0, that indicates
that the register is not known to have been saved. Note that when
basereg == NIOS2_Z_REGNUM (that is, r0, which holds value 0),
addr is an absolute address. */
struct reg_saved
{
int basereg;
CORE_ADDR addr;
};
struct nios2_unwind_cache
{
/* The frame's base, optionally used by the high-level debug info. */
CORE_ADDR base;
/* The previous frame's inner most stack address. Used as this
frame ID's stack_addr. */
CORE_ADDR cfa;
/* The address of the first instruction in this function. */
CORE_ADDR pc;
/* Which register holds the return address for the frame. */
int return_regnum;
/* Table indicating what changes have been made to each register. */
struct reg_value reg_value[NIOS2_NUM_REGS];
/* Table indicating where each register has been saved. */
struct reg_saved reg_saved[NIOS2_NUM_REGS];
};
/* This array is a mapping from Dwarf-2 register numbering to GDB's. */
static int nios2_dwarf2gdb_regno_map[] =
{
0, 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,
NIOS2_GP_REGNUM, /* 26 */
NIOS2_SP_REGNUM, /* 27 */
NIOS2_FP_REGNUM, /* 28 */
NIOS2_EA_REGNUM, /* 29 */
NIOS2_BA_REGNUM, /* 30 */
NIOS2_RA_REGNUM, /* 31 */
NIOS2_PC_REGNUM, /* 32 */
NIOS2_STATUS_REGNUM, /* 33 */
NIOS2_ESTATUS_REGNUM, /* 34 */
NIOS2_BSTATUS_REGNUM, /* 35 */
NIOS2_IENABLE_REGNUM, /* 36 */
NIOS2_IPENDING_REGNUM, /* 37 */
NIOS2_CPUID_REGNUM, /* 38 */
39, /* CTL6 */ /* 39 */
NIOS2_EXCEPTION_REGNUM, /* 40 */
NIOS2_PTEADDR_REGNUM, /* 41 */
NIOS2_TLBACC_REGNUM, /* 42 */
NIOS2_TLBMISC_REGNUM, /* 43 */
NIOS2_ECCINJ_REGNUM, /* 44 */
NIOS2_BADADDR_REGNUM, /* 45 */
NIOS2_CONFIG_REGNUM, /* 46 */
NIOS2_MPUBASE_REGNUM, /* 47 */
NIOS2_MPUACC_REGNUM /* 48 */
};
/* Implement the dwarf2_reg_to_regnum gdbarch method. */
static int
nios2_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int dw_reg)
{
if (dw_reg < 0 || dw_reg > NIOS2_NUM_REGS)
{
warning (_("Dwarf-2 uses unmapped register #%d"), dw_reg);
return dw_reg;
}
return nios2_dwarf2gdb_regno_map[dw_reg];
}
/* Canonical names for the 49 registers. */
static const char *const nios2_reg_names[NIOS2_NUM_REGS] =
{
"zero", "at", "r2", "r3", "r4", "r5", "r6", "r7",
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
"r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
"et", "bt", "gp", "sp", "fp", "ea", "sstatus", "ra",
"pc",
"status", "estatus", "bstatus", "ienable",
"ipending", "cpuid", "ctl6", "exception",
"pteaddr", "tlbacc", "tlbmisc", "eccinj",
"badaddr", "config", "mpubase", "mpuacc"
};
/* Implement the register_name gdbarch method. */
static const char *
nios2_register_name (struct gdbarch *gdbarch, int regno)
{
/* Use mnemonic aliases for GPRs. */
if (regno >= 0 && regno < NIOS2_NUM_REGS)
return nios2_reg_names[regno];
else
return tdesc_register_name (gdbarch, regno);
}
/* Implement the register_type gdbarch method. */
static struct type *
nios2_register_type (struct gdbarch *gdbarch, int regno)
{
/* If the XML description has register information, use that to
determine the register type. */
if (tdesc_has_registers (gdbarch_target_desc (gdbarch)))
return tdesc_register_type (gdbarch, regno);
if (regno == NIOS2_PC_REGNUM)
return builtin_type (gdbarch)->builtin_func_ptr;
else if (regno == NIOS2_SP_REGNUM)
return builtin_type (gdbarch)->builtin_data_ptr;
else
return builtin_type (gdbarch)->builtin_uint32;
}
/* Given a return value in REGCACHE with a type VALTYPE,
extract and copy its value into VALBUF. */
static void
nios2_extract_return_value (struct gdbarch *gdbarch, struct type *valtype,
struct regcache *regcache, gdb_byte *valbuf)
{
int len = TYPE_LENGTH (valtype);
/* Return values of up to 8 bytes are returned in $r2 $r3. */
if (len <= register_size (gdbarch, NIOS2_R2_REGNUM))
regcache_cooked_read (regcache, NIOS2_R2_REGNUM, valbuf);
else
{
gdb_assert (len <= (register_size (gdbarch, NIOS2_R2_REGNUM)
+ register_size (gdbarch, NIOS2_R3_REGNUM)));
regcache_cooked_read (regcache, NIOS2_R2_REGNUM, valbuf);
regcache_cooked_read (regcache, NIOS2_R3_REGNUM, valbuf + 4);
}
}
/* Write into appropriate registers a function return value
of type TYPE, given in virtual format. */
static void
nios2_store_return_value (struct gdbarch *gdbarch, struct type *valtype,
struct regcache *regcache, const gdb_byte *valbuf)
{
int len = TYPE_LENGTH (valtype);
/* Return values of up to 8 bytes are returned in $r2 $r3. */
if (len <= register_size (gdbarch, NIOS2_R2_REGNUM))
regcache_cooked_write (regcache, NIOS2_R2_REGNUM, valbuf);
else
{
gdb_assert (len <= (register_size (gdbarch, NIOS2_R2_REGNUM)
+ register_size (gdbarch, NIOS2_R3_REGNUM)));
regcache_cooked_write (regcache, NIOS2_R2_REGNUM, valbuf);
regcache_cooked_write (regcache, NIOS2_R3_REGNUM, valbuf + 4);
}
}
/* Set up the default values of the registers. */
static void
nios2_setup_default (struct nios2_unwind_cache *cache)
{
int i;
for (i = 0; i < NIOS2_NUM_REGS; i++)
{
/* All registers start off holding their previous values. */
cache->reg_value[i].reg = i;
cache->reg_value[i].offset = 0;
/* All registers start off not saved. */
cache->reg_saved[i].basereg = -1;
cache->reg_saved[i].addr = 0;
}
}
/* Initialize the unwind cache. */
static void
nios2_init_cache (struct nios2_unwind_cache *cache, CORE_ADDR pc)
{
cache->base = 0;
cache->cfa = 0;
cache->pc = pc;
cache->return_regnum = NIOS2_RA_REGNUM;
nios2_setup_default (cache);
}
/* Helper function to identify when we're in a function epilogue;
that is, the part of the function from the point at which the
stack adjustment is made, to the return or sibcall. On Nios II,
we want to check that the CURRENT_PC is a return-type instruction
and that the previous instruction is a stack adjustment.
START_PC is the beginning of the function in question. */
static int
nios2_in_epilogue_p (struct gdbarch *gdbarch,
CORE_ADDR current_pc,
CORE_ADDR start_pc)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
/* There has to be a previous instruction in the function. */
if (current_pc > start_pc)
{
/* Check whether the previous instruction was a stack
adjustment. */
unsigned int insn
= read_memory_unsigned_integer (current_pc - NIOS2_OPCODE_SIZE,
NIOS2_OPCODE_SIZE, byte_order);
if ((insn & 0xffc0003c) == 0xdec00004 /* ADDI sp, sp, */
|| (insn & 0xffc1ffff) == 0xdec1883a /* ADD sp, sp, */
|| (insn & 0xffc0003f) == 0xdec00017) /* LDW sp, constant(sp) */
{
/* Then check if it's followed by a return or a tail
call. */
insn = read_memory_unsigned_integer (current_pc, NIOS2_OPCODE_SIZE,
byte_order);
if (insn == 0xf800283a /* RET */
|| insn == 0xe800083a /* ERET */
|| (insn & 0x07ffffff) == 0x0000683a /* JMP */
|| (insn & 0xffc0003f) == 6) /* BR */
return 1;
}
}
return 0;
}
/* Implement the in_function_epilogue_p gdbarch method. */
static int
nios2_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
{
CORE_ADDR func_addr;
if (find_pc_partial_function (pc, NULL, &func_addr, NULL))
return nios2_in_epilogue_p (gdbarch, pc, func_addr);
return 0;
}
/* Define some instruction patterns supporting wildcard bits via a
mask. */
typedef struct
{
unsigned int insn;
unsigned int mask;
} wild_insn;
static const wild_insn profiler_insn[] =
{
{ 0x0010e03a, 0x00000000 }, /* nextpc r8 */
{ 0xf813883a, 0x00000000 }, /* mov r9,ra */
{ 0x02800034, 0x003fffc0 }, /* movhi r10,257 */
{ 0x52800004, 0x003fffc0 }, /* addi r10,r10,-31992 */
{ 0x00000000, 0xffffffc0 }, /* call */
{ 0x483f883a, 0x00000000 } /* mov ra,r9 */
};
static const wild_insn irqentry_insn[] =
{
{ 0x0031307a, 0x00000000 }, /* rdctl et,estatus */
{ 0xc600004c, 0x00000000 }, /* andi et,et,1 */
{ 0xc0000026, 0x003fffc0 }, /* beq et,zero, */
{ 0x0031313a, 0x00000000 }, /* rdctl et,ipending */
{ 0xc0000026, 0x003fffc0 } /* beq et,zero, */
};
/* Attempt to match SEQUENCE, which is COUNT insns long, at START_PC. */
static int
nios2_match_sequence (struct gdbarch *gdbarch, CORE_ADDR start_pc,
const wild_insn *sequence, int count)
{
CORE_ADDR pc = start_pc;
int i;
unsigned int insn;
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
for (i = 0 ; i < count ; i++)
{
insn = read_memory_unsigned_integer (pc, NIOS2_OPCODE_SIZE, byte_order);
if ((insn & ~sequence[i].mask) != sequence[i].insn)
return 0;
pc += NIOS2_OPCODE_SIZE;
}
return 1;
}
/* Do prologue analysis, returning the PC of the first instruction
after the function prologue. Assumes CACHE has already been
initialized. THIS_FRAME can be null, in which case we are only
interested in skipping the prologue. Otherwise CACHE is filled in
from the frame information.
The prologue will consist of the following parts:
1) Optional profiling instrumentation. The old version uses six
instructions. We step over this if there is an exact match.
nextpc r8
mov r9, ra
movhi r10, %hiadj(.LP2)
addi r10, r10, %lo(.LP2)
call mcount
mov ra, r9
The new version uses two or three instructions (the last of
these might get merged in with the STW which saves RA to the
stack). We interpret these.
mov r8, ra
call mcount
mov ra, r8
2) Optional interrupt entry decision. Again, we step over
this if there is an exact match.
rdctl et,estatus
andi et,et,1
beq et,zero,
rdctl et,ipending
beq et,zero,
3) A stack adjustment or stack which, which will be one of:
addi sp, sp, -constant
or:
movi r8, constant
sub sp, sp, r8
or
movhi r8, constant
addi r8, r8, constant
sub sp, sp, r8
or
movhi rx, %hiadj(newstack)
addhi rx, rx, %lo(newstack)
stw sp, constant(rx)
mov sp, rx
4) An optional stack check, which can take either of these forms:
bgeu sp, rx, +8
break 3
or
bltu sp, rx, .Lstack_overflow
...
.Lstack_overflow:
break 3
5) Saving any registers which need to be saved. These will
normally just be stored onto the stack:
stw rx, constant(sp)
but in the large frame case will use r8 as an offset back
to the cfa:
add r8, r8, sp
stw rx, -constant(r8)
Saving control registers looks slightly different:
rdctl rx, ctlN
stw rx, constant(sp)
6) An optional FP setup, either if the user has requested a
frame pointer or if the function calls alloca.
This is always:
mov fp, sp
The prologue instructions may be interleaved, and the register
saves and FP setup can occur in either order.
To cope with all this variability we decode all the instructions
from the start of the prologue until we hit a branch, call or
return. For each of the instructions mentioned in 3, 4 and 5 we
handle the limited cases of stores to the stack and operations
on constant values. */
static CORE_ADDR
nios2_analyze_prologue (struct gdbarch *gdbarch, const CORE_ADDR start_pc,
const CORE_ADDR current_pc,
struct nios2_unwind_cache *cache,
struct frame_info *this_frame)
{
/* Maximum lines of prologue to check.
Note that this number should not be too large, else we can
potentially end up iterating through unmapped memory. */
CORE_ADDR limit_pc = start_pc + 200;
int regno;
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
/* Does the frame set up the FP register? */
int base_reg = 0;
struct reg_value *value = cache->reg_value;
struct reg_value temp_value[NIOS2_NUM_REGS];
int i;
/* Save the starting PC so we can correct the pc after running
through the prolog, using symbol info. */
CORE_ADDR pc = start_pc;
/* Is this an exception handler? */
int exception_handler = 0;
/* What was the original value of SP (or fake original value for
functions which switch stacks? */
CORE_ADDR frame_high;
/* Is this the end of the prologue? */
int within_prologue = 1;
CORE_ADDR prologue_end;
/* Is this the innermost function? */
int innermost = (this_frame ? (frame_relative_level (this_frame) == 0) : 1);
if (nios2_debug)
fprintf_unfiltered (gdb_stdlog,
"{ nios2_analyze_prologue start=%s, current=%s ",
paddress (gdbarch, start_pc),
paddress (gdbarch, current_pc));
/* Set up the default values of the registers. */
nios2_setup_default (cache);
/* If the first few instructions are the profile entry, then skip
over them. Newer versions of the compiler use more efficient
profiling code. */
if (nios2_match_sequence (gdbarch, pc, profiler_insn,
ARRAY_SIZE (profiler_insn)))
pc += ARRAY_SIZE (profiler_insn) * NIOS2_OPCODE_SIZE;
/* If the first few instructions are an interrupt entry, then skip
over them too. */
if (nios2_match_sequence (gdbarch, pc, irqentry_insn,
ARRAY_SIZE (irqentry_insn)))
{
pc += ARRAY_SIZE (irqentry_insn) * NIOS2_OPCODE_SIZE;
exception_handler = 1;
}
prologue_end = start_pc;
/* Find the prologue instructions. */
while (pc < limit_pc && within_prologue)
{
/* Present instruction. */
uint32_t insn;
int prologue_insn = 0;
if (pc == current_pc)
{
/* When we reach the current PC we must save the current
register state (for the backtrace) but keep analysing
because there might be more to find out (eg. is this an
exception handler). */
memcpy (temp_value, value, sizeof (temp_value));
value = temp_value;
if (nios2_debug)
fprintf_unfiltered (gdb_stdlog, "*");
}
insn = read_memory_unsigned_integer (pc, NIOS2_OPCODE_SIZE, byte_order);
pc += NIOS2_OPCODE_SIZE;
if (nios2_debug)
fprintf_unfiltered (gdb_stdlog, "[%08X]", insn);
/* The following instructions can appear in the prologue. */
if ((insn & 0x0001ffff) == 0x0001883a)
{
/* ADD rc, ra, rb (also used for MOV) */
int ra = GET_IW_A (insn);
int rb = GET_IW_B (insn);
int rc = GET_IW_C (insn);
if (rc == NIOS2_SP_REGNUM
&& rb == 0
&& value[ra].reg == cache->reg_saved[NIOS2_SP_REGNUM].basereg)
{
/* If the previous value of SP is available somewhere
near the new stack pointer value then this is a
stack switch. */
/* If any registers were saved on the stack before then
we can't backtrace into them now. */
for (i = 0 ; i < NIOS2_NUM_REGS ; i++)
{
if (cache->reg_saved[i].basereg == NIOS2_SP_REGNUM)
cache->reg_saved[i].basereg = -1;
if (value[i].reg == NIOS2_SP_REGNUM)
value[i].reg = -1;
}
/* Create a fake "high water mark" 4 bytes above where SP
was stored and fake up the registers to be consistent
with that. */
value[NIOS2_SP_REGNUM].reg = NIOS2_SP_REGNUM;
value[NIOS2_SP_REGNUM].offset
= (value[ra].offset
- cache->reg_saved[NIOS2_SP_REGNUM].addr
- 4);
cache->reg_saved[NIOS2_SP_REGNUM].basereg = NIOS2_SP_REGNUM;
cache->reg_saved[NIOS2_SP_REGNUM].addr = -4;
}
else if (rc != 0)
{
if (value[rb].reg == 0)
value[rc].reg = value[ra].reg;
else if (value[ra].reg == 0)
value[rc].reg = value[rb].reg;
else
value[rc].reg = -1;
value[rc].offset = value[ra].offset + value[rb].offset;
}
prologue_insn = 1;
}
else if ((insn & 0x0001ffff) == 0x0001983a)
{
/* SUB rc, ra, rb */
int ra = GET_IW_A (insn);
int rb = GET_IW_B (insn);
int rc = GET_IW_C (insn);
if (rc != 0)
{
if (value[rb].reg == 0)
value[rc].reg = value[ra].reg;
else
value[rc].reg = -1;
value[rc].offset = value[ra].offset - value[rb].offset;
}
}
else if ((insn & 0x0000003f) == 0x00000004)
{
/* ADDI rb, ra, immed (also used for MOVI) */
short immed = GET_IW_IMM16 (insn);
int ra = GET_IW_A (insn);
int rb = GET_IW_B (insn);
/* The first stack adjustment is part of the prologue.
Any subsequent stack adjustments are either down to
alloca or the epilogue so stop analysing when we hit
them. */
if (rb == NIOS2_SP_REGNUM
&& (value[rb].offset != 0 || value[ra].reg != NIOS2_SP_REGNUM))
break;
if (rb != 0)
{
value[rb].reg = value[ra].reg;
value[rb].offset = value[ra].offset + immed;
}
prologue_insn = 1;
}
else if ((insn & 0x0000003f) == 0x00000034)
{
/* ORHI rb, ra, immed (also used for MOVHI) */
unsigned int immed = GET_IW_IMM16 (insn);
int ra = GET_IW_A (insn);
int rb = GET_IW_B (insn);
if (rb != 0)
{
value[rb].reg = (value[ra].reg == 0) ? 0 : -1;
value[rb].offset = value[ra].offset | (immed << 16);
}
}
else if ((insn & IW_OP_MASK) == OP_STW
|| (insn & IW_OP_MASK) == OP_STWIO)
{
/* STW rb, immediate(ra) */
short immed16 = GET_IW_IMM16 (insn);
int ra = GET_IW_A (insn);
int rb = GET_IW_B (insn);
/* Are we storing the original value of a register?
For exception handlers the value of EA-4 (return
address from interrupts etc) is sometimes stored. */
int orig = value[rb].reg;
if (orig > 0
&& (value[rb].offset == 0
|| (orig == NIOS2_EA_REGNUM && value[rb].offset == -4)))
{
/* We are most interested in stores to the stack, but
also take note of stores to other places as they
might be useful later. */
if ((value[ra].reg == NIOS2_SP_REGNUM
&& cache->reg_saved[orig].basereg != NIOS2_SP_REGNUM)
|| cache->reg_saved[orig].basereg == -1)
{
if (pc < current_pc)
{
/* Save off callee saved registers. */
cache->reg_saved[orig].basereg = value[ra].reg;
cache->reg_saved[orig].addr
= value[ra].offset + GET_IW_IMM16 (insn);
}
prologue_insn = 1;
if (orig == NIOS2_EA_REGNUM || orig == NIOS2_ESTATUS_REGNUM)
exception_handler = 1;
}
}
else
/* Non-stack memory writes are not part of the
prologue. */
within_prologue = 0;
}
else if ((insn & 0xffc1f83f) == 0x0001303a)
{
/* RDCTL rC, ctlN */
int rc = GET_IW_C (insn);
int n = GET_IW_CONTROL_REGNUM (insn);
if (rc != 0)
{
value[rc].reg = NIOS2_STATUS_REGNUM + n;
value[rc].offset = 0;
}
prologue_insn = 1;
}
else if ((insn & 0x0000003f) == 0
&& value[8].reg == NIOS2_RA_REGNUM
&& value[8].offset == 0
&& value[NIOS2_SP_REGNUM].reg == NIOS2_SP_REGNUM
&& value[NIOS2_SP_REGNUM].offset == 0)
{
/* A CALL instruction. This is treated as a call to mcount
if ra has been stored into r8 beforehand and if it's
before the stack adjust.
Note mcount corrupts r2-r3, r9-r15 & ra. */
for (i = 2 ; i <= 3 ; i++)
value[i].reg = -1;
for (i = 9 ; i <= 15 ; i++)
value[i].reg = -1;
value[NIOS2_RA_REGNUM].reg = -1;
prologue_insn = 1;
}
else if ((insn & 0xf83fffff) == 0xd800012e)
{
/* BGEU sp, rx, +8
BREAK 3
This instruction sequence is used in stack checking;
we can ignore it. */
unsigned int next_insn
= read_memory_unsigned_integer (pc, NIOS2_OPCODE_SIZE, byte_order);
if (next_insn != 0x003da0fa)
within_prologue = 0;
else
pc += NIOS2_OPCODE_SIZE;
}
else if ((insn & 0xf800003f) == 0xd8000036)
{
/* BLTU sp, rx, .Lstackoverflow
If the location branched to holds a BREAK 3 instruction
then this is also stack overflow detection. We can
ignore it. */
CORE_ADDR target_pc = pc + ((insn & 0x3fffc0) >> 6);
unsigned int target_insn
= read_memory_unsigned_integer (target_pc, NIOS2_OPCODE_SIZE,
byte_order);
if (target_insn != 0x003da0fa)
within_prologue = 0;
}
/* Any other instructions are allowed to be moved up into the
prologue. If we reach a branch, call or return then the
prologue is considered over. We also consider a second stack
adjustment as terminating the prologue (see above). */
else
{
switch (GET_IW_OP (insn))
{
case OP_BEQ:
case OP_BGE:
case OP_BGEU:
case OP_BLT:
case OP_BLTU:
case OP_BNE:
case OP_BR:
case OP_CALL:
within_prologue = 0;
break;
case OP_OPX:
if (GET_IW_OPX (insn) == OPX_RET
|| GET_IW_OPX (insn) == OPX_ERET
|| GET_IW_OPX (insn) == OPX_BRET
|| GET_IW_OPX (insn) == OPX_CALLR
|| GET_IW_OPX (insn) == OPX_JMP)
within_prologue = 0;
break;
default:
break;
}
}
if (prologue_insn)
prologue_end = pc;
}
/* If THIS_FRAME is NULL, we are being called from skip_prologue
and are only interested in the PROLOGUE_END value, so just
return that now and skip over the cache updates, which depend
on having frame information. */
if (this_frame == NULL)
return prologue_end;
/* If we are in the function epilogue and have already popped
registers off the stack in preparation for returning, then we
want to go back to the original register values. */
if (innermost && nios2_in_epilogue_p (gdbarch, current_pc, start_pc))
nios2_setup_default (cache);
/* Exception handlers use a different return address register. */
if (exception_handler)
cache->return_regnum = NIOS2_EA_REGNUM;
if (nios2_debug)
fprintf_unfiltered (gdb_stdlog, "\n-> retreg=%d, ", cache->return_regnum);
if (cache->reg_value[NIOS2_FP_REGNUM].reg == NIOS2_SP_REGNUM)
/* If the FP now holds an offset from the CFA then this is a
normal frame which uses the frame pointer. */
base_reg = NIOS2_FP_REGNUM;
else if (cache->reg_value[NIOS2_SP_REGNUM].reg == NIOS2_SP_REGNUM)
/* FP doesn't hold an offset from the CFA. If SP still holds an
offset from the CFA then we might be in a function which omits
the frame pointer, or we might be partway through the prologue.
In both cases we can find the CFA using SP. */
base_reg = NIOS2_SP_REGNUM;
else
{
/* Somehow the stack pointer has been corrupted.
We can't return. */
if (nios2_debug)
fprintf_unfiltered (gdb_stdlog, " }\n");
return 0;
}
if (cache->reg_value[base_reg].offset == 0
|| cache->reg_saved[NIOS2_RA_REGNUM].basereg != NIOS2_SP_REGNUM
|| cache->reg_saved[cache->return_regnum].basereg != NIOS2_SP_REGNUM)
{
/* If the frame didn't adjust the stack, didn't save RA or
didn't save EA in an exception handler then it must either
be a leaf function (doesn't call any other functions) or it
can't return. If it has called another function then it
can't be a leaf, so set base == 0 to indicate that we can't
backtrace past it. */
if (!innermost)
{
/* If it isn't the innermost function then it can't be a
leaf, unless it was interrupted. Check whether RA for
this frame is the same as PC. If so then it probably
wasn't interrupted. */
CORE_ADDR ra
= get_frame_register_unsigned (this_frame, NIOS2_RA_REGNUM);
if (ra == current_pc)
{
if (nios2_debug)
fprintf_unfiltered
(gdb_stdlog,
", r%d@r%d+?> }\n",
paddress (gdbarch, cache->reg_value[base_reg].offset),
cache->reg_saved[NIOS2_RA_REGNUM].basereg,
cache->return_regnum,
cache->reg_saved[cache->return_regnum].basereg);
return 0;
}
}
}
/* Get the value of whichever register we are using for the
base. */
cache->base = get_frame_register_unsigned (this_frame, base_reg);
/* What was the value of SP at the start of this function (or just
after the stack switch). */
frame_high = cache->base - cache->reg_value[base_reg].offset;
/* Adjust all the saved registers such that they contain addresses
instead of offsets. */
for (i = 0; i < NIOS2_NUM_REGS; i++)
if (cache->reg_saved[i].basereg == NIOS2_SP_REGNUM)
{
cache->reg_saved[i].basereg = NIOS2_Z_REGNUM;
cache->reg_saved[i].addr += frame_high;
}
for (i = 0; i < NIOS2_NUM_REGS; i++)
if (cache->reg_saved[i].basereg == NIOS2_GP_REGNUM)
{
CORE_ADDR gp = get_frame_register_unsigned (this_frame,
NIOS2_GP_REGNUM);
for ( ; i < NIOS2_NUM_REGS; i++)
if (cache->reg_saved[i].basereg == NIOS2_GP_REGNUM)
{
cache->reg_saved[i].basereg = NIOS2_Z_REGNUM;
cache->reg_saved[i].addr += gp;
}
}
/* Work out what the value of SP was on the first instruction of
this function. If we didn't switch stacks then this can be
trivially computed from the base address. */
if (cache->reg_saved[NIOS2_SP_REGNUM].basereg == NIOS2_Z_REGNUM)
cache->cfa
= read_memory_unsigned_integer (cache->reg_saved[NIOS2_SP_REGNUM].addr,
4, byte_order);
else
cache->cfa = frame_high;
/* Exception handlers restore ESTATUS into STATUS. */
if (exception_handler)
{
cache->reg_saved[NIOS2_STATUS_REGNUM]
= cache->reg_saved[NIOS2_ESTATUS_REGNUM];
cache->reg_saved[NIOS2_ESTATUS_REGNUM].basereg = -1;
}
if (nios2_debug)
fprintf_unfiltered (gdb_stdlog, "cfa=%s }\n",
paddress (gdbarch, cache->cfa));
return prologue_end;
}
/* Implement the skip_prologue gdbarch hook. */
static CORE_ADDR
nios2_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
{
CORE_ADDR limit_pc;
CORE_ADDR func_addr;
struct nios2_unwind_cache cache;
/* See if we can determine the end of the prologue via the symbol
table. If so, then return either PC, or the PC after the
prologue, whichever is greater. */
if (find_pc_partial_function (start_pc, NULL, &func_addr, NULL))
{
CORE_ADDR post_prologue_pc
= skip_prologue_using_sal (gdbarch, func_addr);
if (post_prologue_pc != 0)
return max (start_pc, post_prologue_pc);
}
/* Prologue analysis does the rest.... */
nios2_init_cache (&cache, start_pc);
return nios2_analyze_prologue (gdbarch, start_pc, start_pc, &cache, NULL);
}
/* Implement the breakpoint_from_pc gdbarch hook. */
static const gdb_byte*
nios2_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr,
int *bp_size)
{
/* break encoding: 31->27 26->22 21->17 16->11 10->6 5->0 */
/* 00000 00000 0x1d 0x2d 11111 0x3a */
/* 00000 00000 11101 101101 11111 111010 */
/* In bytes: 00000000 00111011 01101111 11111010 */
/* 0x0 0x3b 0x6f 0xfa */
static const gdb_byte breakpoint_le[] = {0xfa, 0x6f, 0x3b, 0x0};
static const gdb_byte breakpoint_be[] = {0x0, 0x3b, 0x6f, 0xfa};
enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
*bp_size = 4;
if (gdbarch_byte_order_for_code (gdbarch) == BFD_ENDIAN_BIG)
return breakpoint_be;
else
return breakpoint_le;
}
/* Implement the print_insn gdbarch method. */
static int
nios2_print_insn (bfd_vma memaddr, disassemble_info *info)
{
if (info->endian == BFD_ENDIAN_BIG)
return print_insn_big_nios2 (memaddr, info);
else
return print_insn_little_nios2 (memaddr, info);
}
/* Implement the frame_align gdbarch method. */
static CORE_ADDR
nios2_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr)
{
return align_down (addr, 4);
}
/* Implement the return_value gdbarch method. */
static enum return_value_convention
nios2_return_value (struct gdbarch *gdbarch, struct value *function,
struct type *type, struct regcache *regcache,
gdb_byte *readbuf, const gdb_byte *writebuf)
{
if (TYPE_LENGTH (type) > 8)
return RETURN_VALUE_STRUCT_CONVENTION;
if (readbuf)
nios2_extract_return_value (gdbarch, type, regcache, readbuf);
if (writebuf)
nios2_store_return_value (gdbarch, type, regcache, writebuf);
return RETURN_VALUE_REGISTER_CONVENTION;
}
/* Implement the dummy_id gdbarch method. */
static struct frame_id
nios2_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
return frame_id_build
(get_frame_register_unsigned (this_frame, NIOS2_SP_REGNUM),
get_frame_pc (this_frame));
}
/* Implement the push_dummy_call gdbarch method. */
static CORE_ADDR
nios2_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
struct regcache *regcache, CORE_ADDR bp_addr,
int nargs, struct value **args, CORE_ADDR sp,
int struct_return, CORE_ADDR struct_addr)
{
int argreg;
int float_argreg;
int argnum;
int len = 0;
int stack_offset = 0;
CORE_ADDR func_addr = find_function_addr (function, NULL);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
/* Set the return address register to point to the entry point of
the program, where a breakpoint lies in wait. */
regcache_cooked_write_signed (regcache, NIOS2_RA_REGNUM, bp_addr);
/* Now make space on the stack for the args. */
for (argnum = 0; argnum < nargs; argnum++)
len += align_up (TYPE_LENGTH (value_type (args[argnum])), 4);
sp -= len;
/* Initialize the register pointer. */
argreg = NIOS2_FIRST_ARGREG;
/* The struct_return pointer occupies the first parameter-passing
register. */
if (struct_return)
regcache_cooked_write_unsigned (regcache, argreg++, struct_addr);
/* Now load as many as possible of the first arguments into
registers, and push the rest onto the stack. Loop through args
from first to last. */
for (argnum = 0; argnum < nargs; argnum++)
{
const gdb_byte *val;
gdb_byte valbuf[MAX_REGISTER_SIZE];
struct value *arg = args[argnum];
struct type *arg_type = check_typedef (value_type (arg));
int len = TYPE_LENGTH (arg_type);
enum type_code typecode = TYPE_CODE (arg_type);
val = value_contents (arg);
/* Copy the argument to general registers or the stack in
register-sized pieces. Large arguments are split between
registers and stack. */
while (len > 0)
{
int partial_len = (len < 4 ? len : 4);
if (argreg <= NIOS2_LAST_ARGREG)
{
/* The argument is being passed in a register. */
CORE_ADDR regval = extract_unsigned_integer (val, partial_len,
byte_order);
regcache_cooked_write_unsigned (regcache, argreg, regval);
argreg++;
}
else
{
/* The argument is being passed on the stack. */
CORE_ADDR addr = sp + stack_offset;
write_memory (addr, val, partial_len);
stack_offset += align_up (partial_len, 4);
}
len -= partial_len;
val += partial_len;
}
}
regcache_cooked_write_signed (regcache, NIOS2_SP_REGNUM, sp);
/* Return adjusted stack pointer. */
return sp;
}
/* Implement the unwind_pc gdbarch method. */
static CORE_ADDR
nios2_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
gdb_byte buf[4];
frame_unwind_register (next_frame, NIOS2_PC_REGNUM, buf);
return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
}
/* Implement the unwind_sp gdbarch method. */
static CORE_ADDR
nios2_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
return frame_unwind_register_unsigned (this_frame, NIOS2_SP_REGNUM);
}
/* Use prologue analysis to fill in the register cache
*THIS_PROLOGUE_CACHE for THIS_FRAME. This function initializes
*THIS_PROLOGUE_CACHE first. */
static struct nios2_unwind_cache *
nios2_frame_unwind_cache (struct frame_info *this_frame,
void **this_prologue_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
CORE_ADDR current_pc;
struct nios2_unwind_cache *cache;
int i;
if (*this_prologue_cache)
return *this_prologue_cache;
cache = FRAME_OBSTACK_ZALLOC (struct nios2_unwind_cache);
*this_prologue_cache = cache;
/* Zero all fields. */
nios2_init_cache (cache, get_frame_func (this_frame));
/* Prologue analysis does the rest... */
current_pc = get_frame_pc (this_frame);
if (cache->pc != 0)
nios2_analyze_prologue (gdbarch, cache->pc, current_pc, cache, this_frame);
return cache;
}
/* Implement the this_id function for the normal unwinder. */
static void
nios2_frame_this_id (struct frame_info *this_frame, void **this_cache,
struct frame_id *this_id)
{
struct nios2_unwind_cache *cache =
nios2_frame_unwind_cache (this_frame, this_cache);
/* This marks the outermost frame. */
if (cache->base == 0)
return;
*this_id = frame_id_build (cache->cfa, cache->pc);
}
/* Implement the prev_register function for the normal unwinder. */
static struct value *
nios2_frame_prev_register (struct frame_info *this_frame, void **this_cache,
int regnum)
{
struct nios2_unwind_cache *cache =
nios2_frame_unwind_cache (this_frame, this_cache);
gdb_assert (regnum >= 0 && regnum < NIOS2_NUM_REGS);
/* The PC of the previous frame is stored in the RA register of
the current frame. Frob regnum so that we pull the value from
the correct place. */
if (regnum == NIOS2_PC_REGNUM)
regnum = cache->return_regnum;
if (regnum == NIOS2_SP_REGNUM && cache->cfa)
return frame_unwind_got_constant (this_frame, regnum, cache->cfa);
/* If we've worked out where a register is stored then load it from
there. */
if (cache->reg_saved[regnum].basereg == NIOS2_Z_REGNUM)
return frame_unwind_got_memory (this_frame, regnum,
cache->reg_saved[regnum].addr);
return frame_unwind_got_register (this_frame, regnum, regnum);
}
/* Implement the this_base, this_locals, and this_args hooks
for the normal unwinder. */
static CORE_ADDR
nios2_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
struct nios2_unwind_cache *info
= nios2_frame_unwind_cache (this_frame, this_cache);
return info->base;
}
/* Data structures for the normal prologue-analysis-based
unwinder. */
static const struct frame_unwind nios2_frame_unwind =
{
NORMAL_FRAME,
default_frame_unwind_stop_reason,
nios2_frame_this_id,
nios2_frame_prev_register,
NULL,
default_frame_sniffer
};
static const struct frame_base nios2_frame_base =
{
&nios2_frame_unwind,
nios2_frame_base_address,
nios2_frame_base_address,
nios2_frame_base_address
};
/* Fill in the register cache *THIS_CACHE for THIS_FRAME for use
in the stub unwinder. */
static struct trad_frame_cache *
nios2_stub_frame_cache (struct frame_info *this_frame, void **this_cache)
{
CORE_ADDR pc;
CORE_ADDR start_addr;
CORE_ADDR stack_addr;
struct trad_frame_cache *this_trad_cache;
struct gdbarch *gdbarch = get_frame_arch (this_frame);
int num_regs = gdbarch_num_regs (gdbarch);
if (*this_cache != NULL)
return *this_cache;
this_trad_cache = trad_frame_cache_zalloc (this_frame);
*this_cache = this_trad_cache;
/* The return address is in the link register. */
trad_frame_set_reg_realreg (this_trad_cache,
gdbarch_pc_regnum (gdbarch),
NIOS2_RA_REGNUM);
/* Frame ID, since it's a frameless / stackless function, no stack
space is allocated and SP on entry is the current SP. */
pc = get_frame_pc (this_frame);
find_pc_partial_function (pc, NULL, &start_addr, NULL);
stack_addr = get_frame_register_unsigned (this_frame, NIOS2_SP_REGNUM);
trad_frame_set_id (this_trad_cache, frame_id_build (start_addr, stack_addr));
/* Assume that the frame's base is the same as the stack pointer. */
trad_frame_set_this_base (this_trad_cache, stack_addr);
return this_trad_cache;
}
/* Implement the this_id function for the stub unwinder. */
static void
nios2_stub_frame_this_id (struct frame_info *this_frame, void **this_cache,
struct frame_id *this_id)
{
struct trad_frame_cache *this_trad_cache
= nios2_stub_frame_cache (this_frame, this_cache);
trad_frame_get_id (this_trad_cache, this_id);
}
/* Implement the prev_register function for the stub unwinder. */
static struct value *
nios2_stub_frame_prev_register (struct frame_info *this_frame,
void **this_cache, int regnum)
{
struct trad_frame_cache *this_trad_cache
= nios2_stub_frame_cache (this_frame, this_cache);
return trad_frame_get_register (this_trad_cache, this_frame, regnum);
}
/* Implement the sniffer function for the stub unwinder.
This unwinder is used for cases where the normal
prologue-analysis-based unwinder can't work,
such as PLT stubs. */
static int
nios2_stub_frame_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame, void **cache)
{
gdb_byte dummy[4];
struct obj_section *s;
CORE_ADDR pc = get_frame_address_in_block (this_frame);
/* Use the stub unwinder for unreadable code. */
if (target_read_memory (get_frame_pc (this_frame), dummy, 4) != 0)
return 1;
if (in_plt_section (pc))
return 1;
return 0;
}
/* Implement the this_base, this_locals, and this_args hooks
for the stub unwinder. */
static CORE_ADDR
nios2_stub_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
struct trad_frame_cache *this_trad_cache
= nios2_stub_frame_cache (this_frame, this_cache);
return trad_frame_get_this_base (this_trad_cache);
}
/* Define the data structures for the stub unwinder. */
static const struct frame_unwind nios2_stub_frame_unwind =
{
NORMAL_FRAME,
default_frame_unwind_stop_reason,
nios2_stub_frame_this_id,
nios2_stub_frame_prev_register,
NULL,
nios2_stub_frame_sniffer
};
static const struct frame_base nios2_stub_frame_base =
{
&nios2_stub_frame_unwind,
nios2_stub_frame_base_address,
nios2_stub_frame_base_address,
nios2_stub_frame_base_address
};
/* Helper function to read an instruction at PC. */
static unsigned long
nios2_fetch_instruction (struct gdbarch *gdbarch, CORE_ADDR pc)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
return read_memory_unsigned_integer (pc, NIOS2_OPCODE_SIZE, byte_order);
}
/* Determine where to set a single step breakpoint while considering
branch prediction. */
static CORE_ADDR
nios2_get_next_pc (struct frame_info *frame, CORE_ADDR pc)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
unsigned long inst;
int op;
int imm16;
int ra;
int rb;
int ras;
int rbs;
unsigned int rau;
unsigned int rbu;
inst = nios2_fetch_instruction (gdbarch, pc);
pc += NIOS2_OPCODE_SIZE;
imm16 = (short) GET_IW_IMM16 (inst);
ra = GET_IW_A (inst);
rb = GET_IW_B (inst);
ras = get_frame_register_signed (frame, ra);
rbs = get_frame_register_signed (frame, rb);
rau = get_frame_register_unsigned (frame, ra);
rbu = get_frame_register_unsigned (frame, rb);
switch (GET_IW_OP (inst))
{
case OP_BEQ:
if (ras == rbs)
pc += imm16;
break;
case OP_BGE:
if (ras >= rbs)
pc += imm16;
break;
case OP_BGEU:
if (rau >= rbu)
pc += imm16;
break;
case OP_BLT:
if (ras < rbs)
pc += imm16;
break;
case OP_BLTU:
if (rau < rbu)
pc += imm16;
break;
case OP_BNE:
if (ras != rbs)
pc += imm16;
break;
case OP_BR:
pc += imm16;
break;
case OP_JMPI:
case OP_CALL:
pc = (pc & 0xf0000000) | (GET_IW_IMM26 (inst) << 2);
break;
case OP_OPX:
switch (GET_IW_OPX (inst))
{
case OPX_JMP:
case OPX_CALLR:
case OPX_RET:
pc = ras;
break;
case OPX_TRAP:
if (tdep->syscall_next_pc != NULL)
return tdep->syscall_next_pc (frame);
default:
break;
}
break;
default:
break;
}
return pc;
}
/* Implement the software_single_step gdbarch method. */
static int
nios2_software_single_step (struct frame_info *frame)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
struct address_space *aspace = get_frame_address_space (frame);
CORE_ADDR next_pc = nios2_get_next_pc (frame, get_frame_pc (frame));
insert_single_step_breakpoint (gdbarch, aspace, next_pc);
return 1;
}
/* Implement the get_longjump_target gdbarch method. */
static int
nios2_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR jb_addr = get_frame_register_unsigned (frame, NIOS2_R4_REGNUM);
gdb_byte buf[4];
if (target_read_memory (jb_addr + (tdep->jb_pc * 4), buf, 4))
return 0;
*pc = extract_unsigned_integer (buf, 4, byte_order);
return 1;
}
/* Initialize the Nios II gdbarch. */
static struct gdbarch *
nios2_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
struct gdbarch *gdbarch;
struct gdbarch_tdep *tdep;
int register_bytes, i;
struct tdesc_arch_data *tdesc_data = NULL;
const struct target_desc *tdesc = info.target_desc;
if (!tdesc_has_registers (tdesc))
/* Pick a default target description. */
tdesc = tdesc_nios2;
/* Check any target description for validity. */
if (tdesc_has_registers (tdesc))
{
const struct tdesc_feature *feature;
int valid_p;
feature = tdesc_find_feature (tdesc, "org.gnu.gdb.nios2.cpu");
if (feature == NULL)
return NULL;
tdesc_data = tdesc_data_alloc ();
valid_p = 1;
for (i = 0; i < NIOS2_NUM_REGS; i++)
valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
nios2_reg_names[i]);
if (!valid_p)
{
tdesc_data_cleanup (tdesc_data);
return NULL;
}
}
/* Find a candidate among the list of pre-declared architectures. */
arches = gdbarch_list_lookup_by_info (arches, &info);
if (arches != NULL)
return arches->gdbarch;
/* None found, create a new architecture from the information
provided. */
tdep = xcalloc (1, sizeof (struct gdbarch_tdep));
gdbarch = gdbarch_alloc (&info, tdep);
/* longjmp support not enabled by default. */
tdep->jb_pc = -1;
/* Data type sizes. */
set_gdbarch_ptr_bit (gdbarch, 32);
set_gdbarch_addr_bit (gdbarch, 32);
set_gdbarch_short_bit (gdbarch, 16);
set_gdbarch_int_bit (gdbarch, 32);
set_gdbarch_long_bit (gdbarch, 32);
set_gdbarch_long_long_bit (gdbarch, 64);
set_gdbarch_float_bit (gdbarch, 32);
set_gdbarch_double_bit (gdbarch, 64);
set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
/* The register set. */
set_gdbarch_num_regs (gdbarch, NIOS2_NUM_REGS);
set_gdbarch_sp_regnum (gdbarch, NIOS2_SP_REGNUM);
set_gdbarch_pc_regnum (gdbarch, NIOS2_PC_REGNUM); /* Pseudo register PC */
set_gdbarch_register_name (gdbarch, nios2_register_name);
set_gdbarch_register_type (gdbarch, nios2_register_type);
/* Provide register mappings for stabs and dwarf2. */
set_gdbarch_stab_reg_to_regnum (gdbarch, nios2_dwarf_reg_to_regnum);
set_gdbarch_dwarf2_reg_to_regnum (gdbarch, nios2_dwarf_reg_to_regnum);
set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
/* Call dummy code. */
set_gdbarch_frame_align (gdbarch, nios2_frame_align);
set_gdbarch_return_value (gdbarch, nios2_return_value);
set_gdbarch_skip_prologue (gdbarch, nios2_skip_prologue);
set_gdbarch_in_function_epilogue_p (gdbarch, nios2_in_function_epilogue_p);
set_gdbarch_breakpoint_from_pc (gdbarch, nios2_breakpoint_from_pc);
set_gdbarch_dummy_id (gdbarch, nios2_dummy_id);
set_gdbarch_unwind_pc (gdbarch, nios2_unwind_pc);
set_gdbarch_unwind_sp (gdbarch, nios2_unwind_sp);
/* The dwarf2 unwinder will normally produce the best results if
the debug information is available, so register it first. */
dwarf2_append_unwinders (gdbarch);
frame_unwind_append_unwinder (gdbarch, &nios2_stub_frame_unwind);
frame_unwind_append_unwinder (gdbarch, &nios2_frame_unwind);
/* Single stepping. */
set_gdbarch_software_single_step (gdbarch, nios2_software_single_step);
/* Hook in ABI-specific overrides, if they have been registered. */
gdbarch_init_osabi (info, gdbarch);
if (tdep->jb_pc >= 0)
set_gdbarch_get_longjmp_target (gdbarch, nios2_get_longjmp_target);
frame_base_set_default (gdbarch, &nios2_frame_base);
set_gdbarch_print_insn (gdbarch, nios2_print_insn);
/* Enable inferior call support. */
set_gdbarch_push_dummy_call (gdbarch, nios2_push_dummy_call);
if (tdesc_data)
tdesc_use_registers (gdbarch, tdesc, tdesc_data);
return gdbarch;
}
extern initialize_file_ftype _initialize_nios2_tdep; /* -Wmissing-prototypes */
void
_initialize_nios2_tdep (void)
{
gdbarch_register (bfd_arch_nios2, nios2_gdbarch_init, NULL);
initialize_tdesc_nios2 ();
/* Allow debugging this file's internals. */
add_setshow_boolean_cmd ("nios2", class_maintenance, &nios2_debug,
_("Set Nios II debugging."),
_("Show Nios II debugging."),
_("When on, Nios II specific debugging is enabled."),
NULL,
NULL,
&setdebuglist, &showdebuglist);
}