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binutils-gdb/opcodes/nios2-dis.c

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/* Altera Nios II disassemble routines
Copyright (C) 2012-2017 Free Software Foundation, Inc.
Contributed by Nigel Gray (ngray@altera.com).
Contributed by Mentor Graphics, Inc.
This file is part of the GNU opcodes library.
This library 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, or (at your option)
any later version.
It 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 file; see the file COPYING. If not, write to the
Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include "dis-asm.h"
#include "opcode/nios2.h"
#include "libiberty.h"
#include <string.h>
#include <assert.h>
/* No symbol table is available when this code runs out in an embedded
system as when it is used for disassembler support in a monitor. */
#if !defined(EMBEDDED_ENV)
#define SYMTAB_AVAILABLE 1
#include "elf-bfd.h"
#include "elf/nios2.h"
#endif
/* Default length of Nios II instruction in bytes. */
#define INSNLEN 4
/* Data structures used by the opcode hash table. */
typedef struct _nios2_opcode_hash
{
const struct nios2_opcode *opcode;
struct _nios2_opcode_hash *next;
} nios2_opcode_hash;
/* Hash table size. */
#define OPCODE_HASH_SIZE (IW_R1_OP_UNSHIFTED_MASK + 1)
/* Extract the opcode from an instruction word. */
static unsigned int
nios2_r1_extract_opcode (unsigned int x)
{
return GET_IW_R1_OP (x);
}
static unsigned int
nios2_r2_extract_opcode (unsigned int x)
{
return GET_IW_R2_OP (x);
}
/* We maintain separate hash tables for R1 and R2 opcodes, and pseudo-ops
are stored in a different table than regular instructions. */
typedef struct _nios2_disassembler_state
{
const struct nios2_opcode *opcodes;
const int *num_opcodes;
unsigned int (*extract_opcode) (unsigned int);
nios2_opcode_hash *hash[OPCODE_HASH_SIZE];
nios2_opcode_hash *ps_hash[OPCODE_HASH_SIZE];
const struct nios2_opcode *nop;
bfd_boolean init;
} nios2_disassembler_state;
static nios2_disassembler_state
nios2_r1_disassembler_state = {
nios2_r1_opcodes,
&nios2_num_r1_opcodes,
nios2_r1_extract_opcode,
{},
{},
NULL,
0
};
static nios2_disassembler_state
nios2_r2_disassembler_state = {
nios2_r2_opcodes,
&nios2_num_r2_opcodes,
nios2_r2_extract_opcode,
{},
{},
NULL,
0
};
/* Function to initialize the opcode hash table. */
static void
nios2_init_opcode_hash (nios2_disassembler_state *state)
{
unsigned int i;
register const struct nios2_opcode *op;
for (i = 0; i < OPCODE_HASH_SIZE; i++)
for (op = state->opcodes; op < &state->opcodes[*(state->num_opcodes)]; op++)
{
nios2_opcode_hash *new_hash;
nios2_opcode_hash **bucket = NULL;
if ((op->pinfo & NIOS2_INSN_MACRO) == NIOS2_INSN_MACRO)
{
if (i == state->extract_opcode (op->match)
&& (op->pinfo & (NIOS2_INSN_MACRO_MOV | NIOS2_INSN_MACRO_MOVI)
& 0x7fffffff))
{
bucket = &(state->ps_hash[i]);
if (strcmp (op->name, "nop") == 0)
state->nop = op;
}
}
else if (i == state->extract_opcode (op->match))
bucket = &(state->hash[i]);
if (bucket)
{
new_hash =
(nios2_opcode_hash *) malloc (sizeof (nios2_opcode_hash));
if (new_hash == NULL)
{
fprintf (stderr,
"error allocating memory...broken disassembler\n");
abort ();
}
new_hash->opcode = op;
new_hash->next = NULL;
while (*bucket)
bucket = &((*bucket)->next);
*bucket = new_hash;
}
}
state->init = 1;
#ifdef DEBUG_HASHTABLE
for (i = 0; i < OPCODE_HASH_SIZE; ++i)
{
nios2_opcode_hash *tmp_hash = state->hash[i];
printf ("index: 0x%02X ops: ", i);
while (tmp_hash != NULL)
{
printf ("%s ", tmp_hash->opcode->name);
tmp_hash = tmp_hash->next;
}
printf ("\n");
}
for (i = 0; i < OPCODE_HASH_SIZE; ++i)
{
nios2_opcode_hash *tmp_hash = state->ps_hash[i];
printf ("index: 0x%02X ops: ", i);
while (tmp_hash != NULL)
{
printf ("%s ", tmp_hash->opcode->name);
tmp_hash = tmp_hash->next;
}
printf ("\n");
}
#endif /* DEBUG_HASHTABLE */
}
/* Return a pointer to an nios2_opcode struct for a given instruction
word OPCODE for bfd machine MACH, or NULL if there is an error. */
const struct nios2_opcode *
nios2_find_opcode_hash (unsigned long opcode, unsigned long mach)
{
nios2_opcode_hash *entry;
nios2_disassembler_state *state;
/* Select the right instruction set, hash tables, and opcode accessor
for the mach variant. */
if (mach == bfd_mach_nios2r2)
state = &nios2_r2_disassembler_state;
else
state = &nios2_r1_disassembler_state;
/* Build a hash table to shorten the search time. */
if (!state->init)
nios2_init_opcode_hash (state);
/* Check for NOP first. Both NOP and MOV are macros that expand into
an ADD instruction, and we always want to give priority to NOP. */
if (state->nop->match == (opcode & state->nop->mask))
return state->nop;
/* First look in the pseudo-op hashtable. */
for (entry = state->ps_hash[state->extract_opcode (opcode)];
entry; entry = entry->next)
if (entry->opcode->match == (opcode & entry->opcode->mask))
return entry->opcode;
/* Otherwise look in the main hashtable. */
for (entry = state->hash[state->extract_opcode (opcode)];
entry; entry = entry->next)
if (entry->opcode->match == (opcode & entry->opcode->mask))
return entry->opcode;
return NULL;
}
/* There are 32 regular registers, 32 coprocessor registers,
and 32 control registers. */
#define NUMREGNAMES 32
/* Return a pointer to the base of the coprocessor register name array. */
static struct nios2_reg *
nios2_coprocessor_regs (void)
{
static struct nios2_reg *cached = NULL;
if (!cached)
{
int i;
for (i = NUMREGNAMES; i < nios2_num_regs; i++)
if (!strcmp (nios2_regs[i].name, "c0"))
{
cached = nios2_regs + i;
break;
}
assert (cached);
}
return cached;
}
/* Return a pointer to the base of the control register name array. */
static struct nios2_reg *
nios2_control_regs (void)
{
static struct nios2_reg *cached = NULL;
if (!cached)
{
int i;
for (i = NUMREGNAMES; i < nios2_num_regs; i++)
if (!strcmp (nios2_regs[i].name, "status"))
{
cached = nios2_regs + i;
break;
}
assert (cached);
}
return cached;
}
/* Helper routine to report internal errors. */
static void
bad_opcode (const struct nios2_opcode *op)
{
fprintf (stderr, "Internal error: broken opcode descriptor for `%s %s'\n",
op->name, op->args);
abort ();
}
/* The function nios2_print_insn_arg uses the character pointed
to by ARGPTR to determine how it print the next token or separator
character in the arguments to an instruction. */
static int
nios2_print_insn_arg (const char *argptr,
unsigned long opcode, bfd_vma address,
disassemble_info *info,
const struct nios2_opcode *op)
{
unsigned long i = 0;
struct nios2_reg *reg_base;
switch (*argptr)
{
case ',':
case '(':
case ')':
(*info->fprintf_func) (info->stream, "%c", *argptr);
break;
case 'c':
/* Control register index. */
switch (op->format)
{
case iw_r_type:
i = GET_IW_R_IMM5 (opcode);
break;
case iw_F3X6L5_type:
i = GET_IW_F3X6L5_IMM5 (opcode);
break;
default:
bad_opcode (op);
}
reg_base = nios2_control_regs ();
(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
break;
case 'd':
reg_base = nios2_regs;
switch (op->format)
{
case iw_r_type:
i = GET_IW_R_C (opcode);
break;
case iw_custom_type:
i = GET_IW_CUSTOM_C (opcode);
if (GET_IW_CUSTOM_READC (opcode) == 0)
reg_base = nios2_coprocessor_regs ();
break;
case iw_F3X6L5_type:
case iw_F3X6_type:
i = GET_IW_F3X6L5_C (opcode);
break;
case iw_F3X8_type:
i = GET_IW_F3X8_C (opcode);
if (GET_IW_F3X8_READC (opcode) == 0)
reg_base = nios2_coprocessor_regs ();
break;
case iw_F2_type:
i = GET_IW_F2_B (opcode);
break;
default:
bad_opcode (op);
}
if (i < NUMREGNAMES)
(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
else
(*info->fprintf_func) (info->stream, "unknown");
break;
case 's':
reg_base = nios2_regs;
switch (op->format)
{
case iw_r_type:
i = GET_IW_R_A (opcode);
break;
case iw_i_type:
i = GET_IW_I_A (opcode);
break;
case iw_custom_type:
i = GET_IW_CUSTOM_A (opcode);
if (GET_IW_CUSTOM_READA (opcode) == 0)
reg_base = nios2_coprocessor_regs ();
break;
case iw_F2I16_type:
i = GET_IW_F2I16_A (opcode);
break;
case iw_F2X4I12_type:
i = GET_IW_F2X4I12_A (opcode);
break;
case iw_F1X4I12_type:
i = GET_IW_F1X4I12_A (opcode);
break;
case iw_F1X4L17_type:
i = GET_IW_F1X4L17_A (opcode);
break;
case iw_F3X6L5_type:
case iw_F3X6_type:
i = GET_IW_F3X6L5_A (opcode);
break;
case iw_F2X6L10_type:
i = GET_IW_F2X6L10_A (opcode);
break;
case iw_F3X8_type:
i = GET_IW_F3X8_A (opcode);
if (GET_IW_F3X8_READA (opcode) == 0)
reg_base = nios2_coprocessor_regs ();
break;
case iw_F1X1_type:
i = GET_IW_F1X1_A (opcode);
break;
case iw_F1I5_type:
i = 27; /* Implicit stack pointer reference. */
break;
case iw_F2_type:
i = GET_IW_F2_A (opcode);
break;
default:
bad_opcode (op);
}
if (i < NUMREGNAMES)
(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
else
(*info->fprintf_func) (info->stream, "unknown");
break;
case 't':
reg_base = nios2_regs;
switch (op->format)
{
case iw_r_type:
i = GET_IW_R_B (opcode);
break;
case iw_i_type:
i = GET_IW_I_B (opcode);
break;
case iw_custom_type:
i = GET_IW_CUSTOM_B (opcode);
if (GET_IW_CUSTOM_READB (opcode) == 0)
reg_base = nios2_coprocessor_regs ();
break;
case iw_F2I16_type:
i = GET_IW_F2I16_B (opcode);
break;
case iw_F2X4I12_type:
i = GET_IW_F2X4I12_B (opcode);
break;
case iw_F3X6L5_type:
case iw_F3X6_type:
i = GET_IW_F3X6L5_B (opcode);
break;
case iw_F2X6L10_type:
i = GET_IW_F2X6L10_B (opcode);
break;
case iw_F3X8_type:
i = GET_IW_F3X8_B (opcode);
if (GET_IW_F3X8_READB (opcode) == 0)
reg_base = nios2_coprocessor_regs ();
break;
case iw_F1I5_type:
i = GET_IW_F1I5_B (opcode);
break;
case iw_F2_type:
i = GET_IW_F2_B (opcode);
break;
case iw_T1X1I6_type:
i = 0;
break;
default:
bad_opcode (op);
}
if (i < NUMREGNAMES)
(*info->fprintf_func) (info->stream, "%s", reg_base[i].name);
else
(*info->fprintf_func) (info->stream, "unknown");
break;
case 'D':
switch (op->format)
{
case iw_T1I7_type:
i = GET_IW_T1I7_A3 (opcode);
break;
case iw_T2X1L3_type:
i = GET_IW_T2X1L3_B3 (opcode);
break;
case iw_T2X1I3_type:
i = GET_IW_T2X1I3_B3 (opcode);
break;
case iw_T3X1_type:
i = GET_IW_T3X1_C3 (opcode);
break;
case iw_T2X3_type:
if (op->num_args == 3)
i = GET_IW_T2X3_A3 (opcode);
else
i = GET_IW_T2X3_B3 (opcode);
break;
default:
bad_opcode (op);
}
i = nios2_r2_reg3_mappings[i];
(*info->fprintf_func) (info->stream, "%s", nios2_regs[i].name);
break;
case 'M':
/* 6-bit unsigned immediate with no shift. */
switch (op->format)
{
case iw_T1X1I6_type:
i = GET_IW_T1X1I6_IMM6 (opcode);
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'N':
/* 6-bit unsigned immediate with 2-bit shift. */
switch (op->format)
{
case iw_T1X1I6_type:
i = GET_IW_T1X1I6_IMM6 (opcode) << 2;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'S':
switch (op->format)
{
case iw_T1I7_type:
i = GET_IW_T1I7_A3 (opcode);
break;
case iw_T2I4_type:
i = GET_IW_T2I4_A3 (opcode);
break;
case iw_T2X1L3_type:
i = GET_IW_T2X1L3_A3 (opcode);
break;
case iw_T2X1I3_type:
i = GET_IW_T2X1I3_A3 (opcode);
break;
case iw_T3X1_type:
i = GET_IW_T3X1_A3 (opcode);
break;
case iw_T2X3_type:
i = GET_IW_T2X3_A3 (opcode);
break;
case iw_T1X1I6_type:
i = GET_IW_T1X1I6_A3 (opcode);
break;
default:
bad_opcode (op);
}
i = nios2_r2_reg3_mappings[i];
(*info->fprintf_func) (info->stream, "%s", nios2_regs[i].name);
break;
case 'T':
switch (op->format)
{
case iw_T2I4_type:
i = GET_IW_T2I4_B3 (opcode);
break;
case iw_T3X1_type:
i = GET_IW_T3X1_B3 (opcode);
break;
case iw_T2X3_type:
i = GET_IW_T2X3_B3 (opcode);
break;
default:
bad_opcode (op);
}
i = nios2_r2_reg3_mappings[i];
(*info->fprintf_func) (info->stream, "%s", nios2_regs[i].name);
break;
case 'i':
/* 16-bit signed immediate. */
switch (op->format)
{
case iw_i_type:
i = (signed) (GET_IW_I_IMM16 (opcode) << 16) >> 16;
break;
case iw_F2I16_type:
i = (signed) (GET_IW_F2I16_IMM16 (opcode) << 16) >> 16;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'I':
/* 12-bit signed immediate. */
switch (op->format)
{
case iw_F2X4I12_type:
i = (signed) (GET_IW_F2X4I12_IMM12 (opcode) << 20) >> 20;
break;
case iw_F1X4I12_type:
i = (signed) (GET_IW_F1X4I12_IMM12 (opcode) << 20) >> 20;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'u':
/* 16-bit unsigned immediate. */
switch (op->format)
{
case iw_i_type:
i = GET_IW_I_IMM16 (opcode);
break;
case iw_F2I16_type:
i = GET_IW_F2I16_IMM16 (opcode);
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'U':
/* 7-bit unsigned immediate with 2-bit shift. */
switch (op->format)
{
case iw_T1I7_type:
i = GET_IW_T1I7_IMM7 (opcode) << 2;
break;
case iw_X1I7_type:
i = GET_IW_X1I7_IMM7 (opcode) << 2;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'V':
/* 5-bit unsigned immediate with 2-bit shift. */
switch (op->format)
{
case iw_F1I5_type:
i = GET_IW_F1I5_IMM5 (opcode) << 2;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'W':
/* 4-bit unsigned immediate with 2-bit shift. */
switch (op->format)
{
case iw_T2I4_type:
i = GET_IW_T2I4_IMM4 (opcode) << 2;
break;
case iw_L5I4X1_type:
i = GET_IW_L5I4X1_IMM4 (opcode) << 2;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'X':
/* 4-bit unsigned immediate with 1-bit shift. */
switch (op->format)
{
case iw_T2I4_type:
i = GET_IW_T2I4_IMM4 (opcode) << 1;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'Y':
/* 4-bit unsigned immediate without shift. */
switch (op->format)
{
case iw_T2I4_type:
i = GET_IW_T2I4_IMM4 (opcode);
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'o':
/* 16-bit signed immediate address offset. */
switch (op->format)
{
case iw_i_type:
i = (signed) (GET_IW_I_IMM16 (opcode) << 16) >> 16;
break;
case iw_F2I16_type:
i = (signed) (GET_IW_F2I16_IMM16 (opcode) << 16) >> 16;
break;
default:
bad_opcode (op);
}
address = address + 4 + i;
(*info->print_address_func) (address, info);
break;
case 'O':
/* 10-bit signed address offset with 1-bit shift. */
switch (op->format)
{
case iw_I10_type:
i = (signed) (GET_IW_I10_IMM10 (opcode) << 22) >> 21;
break;
default:
bad_opcode (op);
}
address = address + 2 + i;
(*info->print_address_func) (address, info);
break;
case 'P':
/* 7-bit signed address offset with 1-bit shift. */
switch (op->format)
{
case iw_T1I7_type:
i = (signed) (GET_IW_T1I7_IMM7 (opcode) << 25) >> 24;
break;
default:
bad_opcode (op);
}
address = address + 2 + i;
(*info->print_address_func) (address, info);
break;
case 'j':
/* 5-bit unsigned immediate. */
switch (op->format)
{
case iw_r_type:
i = GET_IW_R_IMM5 (opcode);
break;
case iw_F3X6L5_type:
i = GET_IW_F3X6L5_IMM5 (opcode);
break;
case iw_F2X6L10_type:
i = GET_IW_F2X6L10_MSB (opcode);
break;
case iw_X2L5_type:
i = GET_IW_X2L5_IMM5 (opcode);
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'k':
/* Second 5-bit unsigned immediate field. */
switch (op->format)
{
case iw_F2X6L10_type:
i = GET_IW_F2X6L10_LSB (opcode);
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'l':
/* 8-bit unsigned immediate. */
switch (op->format)
{
case iw_custom_type:
i = GET_IW_CUSTOM_N (opcode);
break;
case iw_F3X8_type:
i = GET_IW_F3X8_N (opcode);
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%lu", i);
break;
case 'm':
/* 26-bit unsigned immediate. */
switch (op->format)
{
case iw_j_type:
i = GET_IW_J_IMM26 (opcode);
break;
case iw_L26_type:
i = GET_IW_L26_IMM26 (opcode);
break;
default:
bad_opcode (op);
}
/* This translates to an address because it's only used in call
instructions. */
address = (address & 0xf0000000) | (i << 2);
(*info->print_address_func) (address, info);
break;
case 'e':
/* Encoded enumeration for addi.n/subi.n. */
switch (op->format)
{
case iw_T2X1I3_type:
i = nios2_r2_asi_n_mappings[GET_IW_T2X1I3_IMM3 (opcode)];
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%lu", i);
break;
case 'f':
/* Encoded enumeration for slli.n/srli.n. */
switch (op->format)
{
case iw_T2X1L3_type:
i = nios2_r2_shi_n_mappings[GET_IW_T2X1I3_IMM3 (opcode)];
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%lu", i);
break;
case 'g':
/* Encoded enumeration for andi.n. */
switch (op->format)
{
case iw_T2I4_type:
i = nios2_r2_andi_n_mappings[GET_IW_T2I4_IMM4 (opcode)];
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%lu", i);
break;
case 'h':
/* Encoded enumeration for movi.n. */
switch (op->format)
{
case iw_T1I7_type:
i = GET_IW_T1I7_IMM7 (opcode);
if (i == 125)
i = 0xff;
else if (i == 126)
i = -2;
else if (i == 127)
i = -1;
break;
default:
bad_opcode (op);
}
(*info->fprintf_func) (info->stream, "%ld", i);
break;
case 'R':
{
unsigned long reglist = 0;
int dir = 1;
int k, t;
switch (op->format)
{
case iw_F1X4L17_type:
/* Encoding for ldwm/stwm. */
i = GET_IW_F1X4L17_REGMASK (opcode);
if (GET_IW_F1X4L17_RS (opcode))
{
reglist = ((i << 14) & 0x00ffc000);
if (i & (1 << 10))
reglist |= (1 << 28);
if (i & (1 << 11))
reglist |= (1 << 31);
}
else
reglist = i << 2;
dir = GET_IW_F1X4L17_REGMASK (opcode) ? 1 : -1;
break;
case iw_L5I4X1_type:
/* Encoding for push.n/pop.n. */
reglist |= (1 << 31);
if (GET_IW_L5I4X1_FP (opcode))
reglist |= (1 << 28);
if (GET_IW_L5I4X1_CS (opcode))
{
int val = GET_IW_L5I4X1_REGRANGE (opcode);
reglist |= nios2_r2_reg_range_mappings[val];
}
dir = (op->match == MATCH_R2_POP_N ? 1 : -1);
break;
default:
bad_opcode (op);
}
t = 0;
(*info->fprintf_func) (info->stream, "{");
for (k = (dir == 1 ? 0 : 31);
(dir == 1 && k < 32) || (dir == -1 && k >= 0);
k += dir)
if (reglist & (1 << k))
{
if (t)
(*info->fprintf_func) (info->stream, ",");
else
t++;
(*info->fprintf_func) (info->stream, "%s", nios2_regs[k].name);
}
(*info->fprintf_func) (info->stream, "}");
break;
}
case 'B':
/* Base register and options for ldwm/stwm. */
switch (op->format)
{
case iw_F1X4L17_type:
if (GET_IW_F1X4L17_ID (opcode) == 0)
(*info->fprintf_func) (info->stream, "--");
i = GET_IW_F1X4I12_A (opcode);
(*info->fprintf_func) (info->stream, "(%s)",
nios2_builtin_regs[i].name);
if (GET_IW_F1X4L17_ID (opcode))
(*info->fprintf_func) (info->stream, "++");
if (GET_IW_F1X4L17_WB (opcode))
(*info->fprintf_func) (info->stream, ",writeback");
if (GET_IW_F1X4L17_PC (opcode))
(*info->fprintf_func) (info->stream, ",ret");
break;
default:
bad_opcode (op);
}
break;
default:
(*info->fprintf_func) (info->stream, "unknown");
break;
}
return 0;
}
/* nios2_disassemble does all the work of disassembling a Nios II
instruction opcode. */
static int
nios2_disassemble (bfd_vma address, unsigned long opcode,
disassemble_info *info)
{
const struct nios2_opcode *op;
info->bytes_per_line = INSNLEN;
info->bytes_per_chunk = INSNLEN;
info->display_endian = info->endian;
info->insn_info_valid = 1;
info->branch_delay_insns = 0;
info->data_size = 0;
info->insn_type = dis_nonbranch;
info->target = 0;
info->target2 = 0;
/* Find the major opcode and use this to disassemble
the instruction and its arguments. */
op = nios2_find_opcode_hash (opcode, info->mach);
if (op != NULL)
{
const char *argstr = op->args;
(*info->fprintf_func) (info->stream, "%s", op->name);
if (argstr != NULL && *argstr != '\0')
{
(*info->fprintf_func) (info->stream, "\t");
while (*argstr != '\0')
{
nios2_print_insn_arg (argstr, opcode, address, info, op);
++argstr;
}
}
/* Tell the caller how far to advance the program counter. */
info->bytes_per_chunk = op->size;
return op->size;
}
else
{
/* Handle undefined instructions. */
info->insn_type = dis_noninsn;
(*info->fprintf_func) (info->stream, "0x%lx", opcode);
return INSNLEN;
}
}
/* print_insn_nios2 is the main disassemble function for Nios II.
The function diassembler(abfd) (source in disassemble.c) returns a
pointer to this either print_insn_big_nios2 or
print_insn_little_nios2, which in turn call this function when the
bfd machine type is Nios II. print_insn_nios2 reads the
instruction word at the address given, and prints the disassembled
instruction on the stream info->stream using info->fprintf_func. */
static int
print_insn_nios2 (bfd_vma address, disassemble_info *info,
enum bfd_endian endianness)
{
bfd_byte buffer[INSNLEN];
int status;
status = (*info->read_memory_func) (address, buffer, INSNLEN, info);
if (status == 0)
{
unsigned long insn;
if (endianness == BFD_ENDIAN_BIG)
insn = (unsigned long) bfd_getb32 (buffer);
else
insn = (unsigned long) bfd_getl32 (buffer);
return nios2_disassemble (address, insn, info);
}
/* We might have a 16-bit R2 instruction at the end of memory. Try that. */
if (info->mach == bfd_mach_nios2r2)
{
status = (*info->read_memory_func) (address, buffer, 2, info);
if (status == 0)
{
unsigned long insn;
if (endianness == BFD_ENDIAN_BIG)
insn = (unsigned long) bfd_getb16 (buffer);
else
insn = (unsigned long) bfd_getl16 (buffer);
return nios2_disassemble (address, insn, info);
}
}
/* If we got here, we couldn't read anything. */
(*info->memory_error_func) (status, address, info);
return -1;
}
/* These two functions are the main entry points, accessed from
disassemble.c. */
int
print_insn_big_nios2 (bfd_vma address, disassemble_info *info)
{
return print_insn_nios2 (address, info, BFD_ENDIAN_BIG);
}
int
print_insn_little_nios2 (bfd_vma address, disassemble_info *info)
{
return print_insn_nios2 (address, info, BFD_ENDIAN_LITTLE);
}
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